Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/20/15
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
939 PM CDT SUN JUL 19 2015
.UPDATE...
QUICK UPDATE TO THE FORECAST WITH SHOWERS AND THUNDERSTORMS
CONTINUING TO DEVELOP IN MISSOURI. IN ADDITION TO THE 12Z
WRF AND 00Z NAM...THE LATEST HRRR RUNS HAVE SHOWED FAIRLY GOOD
CONTINUITY WITH THESE THUNDERSTORMS CONTINUING TO DEVELOP AND PUSH
SOUTH THROUGH THE OVERNIGHT AND EARLY MORNING HOURS ACROSS
NORTHERN AND NORTHEAST ARKANSAS. CURRENT RADAR TRENDS DO SUGGEST
THE BEST CHANCES FOR PRECIPITATION WILL BE TO THE NORTHEAST OF
THE CWA...BUT WITHIN THE PAST HOUR ADDITIONAL STORMS HAVE BEGUN TO
DEVELOP A BIT FURTHER TO THE WEST OF THE MAIN SET OF STORMS. AS
SUCH...TOOK A CONSERVATIVE APPROACH FOR NOW AND JUST ADDED SOME
SLIGHT CHANCE POPS TO NORTHERN ARKANSAS...AS THESE STORMS SHOULD
WEAKEN DURING THE EARLY MORNING HOURS.
&&
.PREV DISCUSSION... /ISSUED 656 PM CDT SUN JUL 19 2015/
AVIATION...
HIGH PRESSURE WILL DOMINATE ONCE AGAIN WITH WIDESPREAD VFR
CONDITIONS. SOME MOISTURE WILL BEGIN TO INCREASE OVER THE NORTH
LATE AS A FRONT APPROACHES FROM THE NORTH.
PREV DISCUSSION... /ISSUED 255 PM CDT SUN JUL 19 2015/
SHORT TERM...TONIGHT THROUGH WEDNESDAY
HIGH PRESSURE ALOFT REMAINS OVER THE AREA THROUGH WEDNESDAY. MODELS
ARE INDICATING A COLD FRONT MOVING INTO SOUTHERN MISSOURI MONDAY AND
THEN INTO NORTH ARKANSAS TUESDAY. THE FRONT WILL THEN STALL IN SOUTH
ARKANSAS WEDNESDAY. THE FRONT WILL BRING CHANCES FOR SHOWERS AND
THUNDERSTORMS STARTING IN THE NORTH MONDAY THEN MOVING SOUTH.
THE HEAT ADVISORY WILL CONTINUE THROUGH MONDAY. HEAT INDICES OF 105
TO 110 DEGREES ARE EXPECTED ACROSS CENTRAL...SOUTH AND EAST
SECTIONS. TEMPERATURES WILL BE A FEW DEGREES COOLER TUESDAY AND
WEDNESDAY DUE TO INCREASED CLOUDS AND RAIN CHANCES.
LONG TERM...THURSDAY THROUGH SUNDAY
A RIDGE OF HIGH PRESSURE WILL REMAIN JUST TO THE SOUTHWEST OVER THE
SOUTHERN PLAINS AND SOUTHERN ROCKIES. IT WILL BE FAR ENOUGH AWAY TO
KEEP A WEAK FRONT/BOUNDARY ACROSS ARKANSAS THROUGH MUCH OF THE
PERIOD. THE FRONT WILL DO LITTLE TO COOL IT OFF AROUND HERE...WITH
AT/ABOVE NORMAL TEMPERATURES IN THE FORECAST. HOWEVER...WITH A FRONT
IN THE AREA...KEPT ISOLATED TO SCATTERED SHOWERS/THUNDERSTORMS IN
THE FORECAST...MAINLY DURING THE HEAT OF THE AFTERNOON AND
EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 74 97 74 89 / 10 20 30 30
CAMDEN AR 75 97 76 97 / 0 10 10 10
HARRISON AR 74 93 73 87 / 20 30 40 40
HOT SPRINGS AR 75 96 76 95 / 10 10 10 20
LITTLE ROCK AR 76 98 77 95 / 10 10 10 20
MONTICELLO AR 77 98 76 96 / 0 10 10 10
MOUNT IDA AR 74 95 75 93 / 10 10 10 20
MOUNTAIN HOME AR 74 94 73 89 / 20 30 40 40
NEWPORT AR 75 98 75 91 / 20 20 30 30
PINE BLUFF AR 76 98 76 95 / 0 10 10 10
RUSSELLVILLE AR 75 96 75 93 / 10 20 20 30
SEARCY AR 74 98 75 92 / 10 10 20 20
STUTTGART AR 77 99 77 95 / 0 10 10 20
&&
.LZK WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 7 PM CDT MONDAY FOR ARKANSAS-BRADLEY-CALHOUN-
CLARK-CLEBURNE-CLEVELAND-CONWAY-DALLAS-DESHA-DREW-FAULKNER-
GARLAND-GRANT-HOT SPRING-INDEPENDENCE-JACKSON-JEFFERSON-LINCOLN-
LONOKE-MONROE-OUACHITA-PERRY-PRAIRIE-PULASKI-SALINE-WHITE-
WOODRUFF.
&&
$$
65
AREA FORECAST DISCUSSION
NWS PUEBLO CO
310 PM MDT SAT JUL 18 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 310 PM MDT SAT JUL 18 2015
...A WET DAY LIKELY TOMORROW AFTERNOON...
CURRENTLY...
TWO DISTURBANCES OF NOTE...THE FIRST WAS MOVING OVER THE CENTRAL
PART OF COLORADO. A BROAD LINE OF SHOWERS AND THUNDERSTORMS EXTENDED
NNE-SSW WITH THIS DISTURBANCE AND WAS LOCATED OVER THE CENTRAL PART
OF THE STATE. THE 2ND DISTURBANCE WAS OVER SOUTHERN CALIF/LAS VEGAS
REGION. QUITE A BIT OF CONVECTION WAS ASSOCIATED WITH THIS 2ND
DISTURBANCE.
REST OF TODAY AND TONIGHT...
COULD SEE 2 MCS`S DEVELOP LATE THIS AFTERNOON/EVENING. THE FIRST
WILL BE OVER NE CO AND THE 2ND COULD BE FARTHER SOUTH OVER SE
COLORADO. ALTHOUGH BEST FORCING IS LIFTING OFF NORTHEAST TOWARDS NE
CO...THE BETTER INSTABILITY IS LOCATED OVER SE COLO. NEW 18Z NAM IS
CATCHING ON TO THIS POSSIBILITY. HRRR ALSO SHOWS MODEST TO STRONGER
CONVECTION EXTENDING N-S ALONG THE HI PLAINS LATER THIS EVENING. 12
GFS WAS NOT SHOWING MUCH OF ANYTHING OVER THE HI PLAINS ADJ TO COLO
LATER THIS EVENING. ATTM...I HAVE HI ISOLD POPS ALONG MOST OF THE I-
25 CORRIDOR BECOMING SCTD POPS OVER THE FAR EASTERN PLAINS LATER
THIS EVENING.
PRECIP WILL LIKELY LINGER INTO THE EARLY MORNING HOURS ALL AREAS
GIVEN THE MOISTURE PLUME OVER THE REGION...AND HAVE KEPT LOW POPS
MOST AREAS.
WE COULD STILL SEE A FEW MARGINAL SEVERE STORMS TODAY ACROSS THE
REGION...ESPECIALLY EL PASO AND THE FAR E PLAINS.
TOMORROW...
QUITE A BIT OF CLOUDS WILL LIKELY BE OVER THE REGION TOMORROW
MORNING. GUIDANCE IS NOT SHOWING ANY LOW CIGS GIVEN THE WIND
FLOW...BUT IF THE MCS`S BECOME QUITE STRONG THEN SOME LOW STRATUS
COULD DEVELOP OVER THE REGION EARLY TOMORROW.
TOMORROW THE GUIDANCE IS RATHER HIGH WITH POPS MOVING OVER THE
REGION...AND GIVEN THE WELL DEFINED DISTURBANCE OVER THE CALIF
REGION...THESE VALUES ARE WARRANTED. PRECIP SHOULD DEVELOP RATHER
EARLY IN THE MTNS AND MOVE EASTWARD W/TIME. I PAINTED HIGH
SCTD/LIKELY POPS OVER THE MTNS...ESPECIALLY THE CONTDVD. FLASH
FLOODING OVER THE HI TRRN COULD OCCUR...BUT WILL DEFER TO LATER
SHIFTS TO ISSUE ANY HILITES.
FOR THE PLAINS...ALTHOUGH ALL GUIDANCE BLOWS UP CONVECTION OVER THE
HI PLAINS TOMORROW...THEY ARE HAVING A PROBLEM WITH LOCATION. EC HAS
THE MCS BLOWING UP RELATIVELY EARLY OVER EAST CENTRAL CO...THE NAM
APPEARS TO ONCE AGAIN DEVELOP A COUPLE OF MCS`S OVER THE HI PLAINS
WHILE THE GFS IS OVER NE COLORADO. WPC HAS THE BULLSEYE OVER EC
COLO. FOR NOW PAINTED SCTD POPS OVER THE PLAINS BY LATE AFTERNOON
TOMORROW. WE WILL ALSO LIKELY SEE SOME HEAVY RAIN LATE TOMORROW
AFTERNOON OVER THE LOWER ELEVATIONS AND HAVE PAINTED MDT RAIN IN THE
NDFD.
STRONG TO MARGINALLY SVR STORMS WILL ONCE AGAIN BE POSSIBLE TOMORROW
AFTERNOON ACROSS THE REGION. /HODANISH
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 310 PM MDT SAT JUL 18 2015
LITTLE CHANGE TO THE EXPECTED WEATHER TREND THROUGH THE
EXTENDED...WITH A SLIGHTLY SLOWER PROGRESSION OF THE REMNANTS OF
TROPICAL STORM DOLORES.
SUNDAY NIGHT THROUGH TUESDAY...THE FLAT UPPER RIDGE WILL REMAIN
LOCKED OVER THE SOUTHERN U.S. THROUGH THE EXTENDED PERIOD...BUT A
COUPLE OF DISTURBANCES WILL KEEP THE PATTERN ACTIVE THROUGH TUE.
FIRST...AN UPPER SHORTWAVE WILL CROSS MT AND WY SUN EVE...PUSHING A
FRONT DOWN ACROSS THE PALMER DVD AND SOUTHEASTERN PLAINS ON MON. THE
SECOND FEATURE WILL BE THE REMNANTS OF DOLORES...WHICH IS FORECAST
TO TRACK EAST ACROSS THE GREAT BASIN ON MON AND COLORADO ON TUE.
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED EACH AFTN AND EVE
ACROSS ALL OF THE FORECAST AREA...WITH LINGERING ISOLATED ACTIVITY
INTO THE NIGHT. ACROSS THE MTS AND IMMEDIATELY ADJACENT
PLAINS...CONVECTION WILL BE LIKELY THROUGH THE AFTN AND EARLY EVE
HOURS. THIS INCREASED ACTIVITY AND CLOUD COVER IS EXPECTED TO KEEP
MAX TEMPS BELOW NORMAL...WITH 80S ACROSS THE PLAINS AND 70S FOR THE
HIGH VALLEYS SUNDAY THROUGH TUESDAY. THERE IS THE POTENTIAL FOR
HEAVIER RAINFALL EACH DAY THROUGH THE LATE AFTN AND EARLY EVE
HOURS...SO THERE WILL BE THE HEIGHTENED THREAT OF FLASH FLOODING FOR
AREA BURN SCARS.
WEDNESDAY THROUGH SATURDAY...A MORE WEST TO SOUTHWEST FLOW ALOFT
THEN DEVELOPS ACROSS THE 4 CORNERS STARTING WED AND LASTING INTO THE
WEEKEND...AS UPPER HIGH PRESSURE REACHES BACK ACROSS NM AND AZ...AND
ANOTHER UPPER LOW PRES TROUGH STARTS TO DIG DOWN OVER THE PAC NW.
WED LOOKS TO BE A TRANSITIONAL DAY FOR THE WEATHER PATTERN...SO PCPN
CHANCES WILL BE ON THE DECREASE WED AS TEMPS START TO GRADUALLY
WARM. MODELS INDICATE THE AVAILABLE MOISTURE TAP WILL BE SUPPRESSED
TO THE SOUTH OF CO THROUGH THIS PERIOD...WITH JUST ISOLATED DIURNAL
MOUNTAIN CONVECTION FORECAST. TEMPS WILL WARM BACK UP TO NEAR
SEASONAL NORMS...WITH MAX READINGS IN THE 90S FOR THE PLAINS AND 80S
FOR THE HIGH VALLEYS. MOORE
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 310 PM MDT SAT JUL 18 2015
KCOS...TSRA ARE LIKELY LATER THIS AFTERNOON/EARLY EVENING. GUSTY
WINDS AND BRIEF HEAVY RAIN AND POSSIBLY SMALL HAIL POSSIBLE. SHOULD
SEE VFR TONIGHT AND TOMORROW...BUT WILL ONCE AGAIN SEE SOME MORE
TSRA BY TOMORROW AFTERNOON AT COLORADO SPRINGS.
KPUB...ISOLD TSRA POSSIBLE THIS LATE AFTERNOON AND EVENING. WE WILL
LIKELY SEE A GUST FRONT MOVE ACROSS THE REGION EARLY THIS EVENING
ASSOCIATED WITH THE CONVECTION. OTHERWISE VFR EXPECTED. MORE TSRA
ACTIVITY IS LIKELY TOMORROW AFTERNOON.
KALS...LOTS OF MOISTURE AROUND IN THE MTNS AND ISOLD TO SCTD TSRA
WILL OCCUR THIS AFTERNOON AND TOMORROW AFTERNOON. SHOULD SEE VFR
OUTSIDE THE STRONGER TSRA ACTIVITY. GUSTY WINDS WILL BE POSSIBLE.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...HODANISH
LONG TERM...MOORE
AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1016 AM MDT SAT JUL 18 2015
.UPDATE...
ISSUED AT 952 AM MDT SAT JUL 18 2015
EARLY MORNING LIGHTNING THIS MORNING IN UTAH ABOUT THE HEAD INTO
WESTERN COLORADO...BUT ALL QUIET IN EASTERN COLORADO. ONE WEAK
FRONT CAME OVERNIGHT...AND THERE ARE SOME PRESSURE RISES IN
EASTERN WYOMING AND NORTHWEST NEBRASKA THAT MAY BE ASSOCIATED WITH
ANOTHER WEAK FRONT.
MODELS DO NOT HAVE CONVECTION ON THE PLAINS UNTIL MID
AFTERNOON...AND HAVE SLOWED THE ARRIVAL OF THUNDERSTORMS ON THE
PLAINS THIS AFTERNOON. STILL LOOKS LIKE WE WILL HAVE SCATTERED TO
LIKELY THUNDERSTORMS IN NORTHEAST COLORADO BY THIS EVENING...AND
SOME OF THOSE STORMS BORDERING GOODLAND AREA MAY LINGER LATE. NAM
IS RATHER EXCITABLE WITH CAPES OVER 2000 TONIGHT OVER NORTHEAST
COLORADO...WILL BE INTERESTING TO SEE WHAT OTHER 12Z MODELS DO.
INITIAL THOUGHT IS SPC SLIGHT RISK APPEARS TO BE A BIT TOO FAR
WEST.
MODELS SHOW GOOD EASTERLY FLOW THIS EVENING AND GOOD
SATURATION OF THE BOUNDARY AREA...SO STRATUS AND PATCHY FOG
LOOKING VERY POSSIBLE AFTER 09Z OVER MUCH OF EASTERN COLORADO.
THESE CLOUDS SHOULD LINGER THROUGH MID MORNING MONDAY.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 308 AM MDT SAT JUL 18 2015
SWLY FLOW ALOFT WILL BE OVER THE AREA TODAY THRU TONIGHT. AT THE
SFC A WK SURGE MOVED ACROSS NERN CO LAST EVENING BUT HAS PRETTY
MIXED OUT THE LAST FEW HOURS. OVERALL AM GETTING CONFLICTING
SIGNALS ON HOW THE SFC PTRN IS GOING TO EVOLVE THIS AFTN. THE NAM
AND HIRES MODEL WANT TO BRING ANOTHER SURGE INTO NERN CO BY MIDDAY
WHILE THE HRRR AND RAP KEEP THIS BNDRY FURTHER NORTH OVER SERN WY
AND WRN NE THRU THE AFTN HOURS. AS A RESULT DEWPOINTS MIX OUT INTO
THE 30S AND 40S IN THE RAP AND HRRR WHILE THE NAM AND HIRES KEEP
THEM IN THE 50S. FURTHERMORE THIS LEADS TO LARGE DIFFERENCES IN
FCST CAPE BY MID TO AFTN WITH 2000 J/KG OR MORE ACROSS NERN CO AS
SHOWN BY THE NAM WITH 500-1000 J/KG IN THE HRRR AND RAP. ANOTHER
PROBLEM TO CONSIDER IS THAT EVEN IF THE NAM IS CORRECT WITH THE MUCH
HIGHER CAPE VALUES IT HAS A DECENT CAP IN PLACE THRU THE AFTN ACROSS
ALL OF NERN CO. IN ADDITION THERE IS SOME MID LVL DESCENT SHOWN AS
WELL THRU THE AFTN HOURS WHICH COULD LIMIT TSTM ACTIVITY AS WELL.
AT THIS POINT THERE ARE SO MANY CONFLICTING SIGNALS EVEN IF I ADJUST
THINGS I COULD GO IN THE WRONG DIRECTION SO WILL LEAVE INHERITED
POPS ALONE FOR THE AFTN HOURS. NATURALLY IF THE HIGHER CAPE VALUES
ARE IN PLACE AND THE CAP IS BKN THERE WOULD CERTAINLY BE THE
POTENTIAL FOR SOME SVR STORMS DUE TO FAVORABLE SHEAR. CIPS GUIDANCE
SHOWS THE HIGHEST POTENTIAL OVER THE NERN PLAINS MAINLY NE OF A LINE
FROM BRIGGSDALE TO WIGGINS TO LAST CHANCE.
OVER THE HIGHER TERRAIN STORMS WILL BE HIGH BASED AND PRODUCE GUSTY
WINDS BUT LIMITED RAINFALL. MEANWHILE ANOTHER PROBLEM FOR TODAY IS
HIGH TEMPERATURES. DEPENDING ON THE TIMING OF THE COOL FNT HIGHS
COULD EASILY RISE BACK INTO THE LOWER TO MID 90S ACROSS NERN CO IF
THE FNT IS SLOWER LIKE THE RAP/HRRR SHOW. FOR NOW WILL KEEP
READINGS IN THE MID 80S TO NR 90 HOWEVER THEY MAY END UP BEING TOO
COOL.
FOR THIS EVENING LOW LVL MOISTURE WILL INCREASE OVER THE PLAINS
BEHIN THE COOL FNT AS SOME WK MID LVL ASCENT MOVE ACROSS. THIS
SHOULD LEAD TO A BETTER CHC OF STORMS ACROSS NERN CO WITH SOME OF
THE ACTIVITY POSSIBLY LINGERING AFTER MIDNIGHT OVER THE FAR NERN
PLAINS. ONCE AGAIN THERE WILL BE THE POTENTIAL FOR A FEW SVR
STORMS ALONG WITH SOME HEAVY RAINFALL WELL DUE TO INCREASING
PRECIPITABLE WATER VALUES. LATE TONIGHT WITH SEE AREAS OF STRATUS
DVLP OVER MUCH OF NERN CO DUE TO UPSLOPE FLOW AND INCREASING LOW
LVL MOISTURE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 308 AM MDT SAT JUL 18 2015
INCREASED MOISTURE THROUGH THE BEGINNING OF THE WEEK WILL INCREASE
CONVECTION WITH SLIGHTLY BELOW AVERAGE TEMPERATURES. LOOK FOR DRIER
AND WARMER CONDITIONS TOWARD THE END OF THE WEEK.
SUNDAY WILL BRING MOSTLY CLOUDY CONDITIONS WITH SLIGHTLY COOLER
TEMPERATURES DUE IN PART TO A FRONT THAT WILL PUSH THROUGH THE
REGION EARLIER IN THE MORNING. MOISTURE PW VALUES WILL INCREASE ABOVE
1 INCH WITH ENHANCED UPSLOPE FLOW. WARMING AND THEREFORE CONVECTION
WILL BE INHIBITED THROUGH THE DAY BY CLOUD COVER AND MID LEVEL
STABILITY. WILL MAINTAIN SCATTERED STORMS OVER THE MOUNTAINS WITH
ONLY ISOLATED ON THE PLAINS TOWARD THE LATE AFTERNOON AND EVENING.
MAIN THREATS WILL BE HEAVY RAIN AND WINDS WITH THE STORMS.
SUNDAY NIGHT INTO MONDAY WILL SEE STORMS CONTINUING INTO EARLY
MORNING BEFORE DISSIPATING. WESTERLY UPPER LEVEL FLOW INCREASES WITH
A SLIGHT DROP IN PW VALUES AS THE MOISTURE GETS CUTS OFF.
HOWEVER...WITH LINGERING MOISTURE IN THE MOUNTAINS WILL MAINTAIN
INCREASED POPS FOR MONDAY AS AFTERNOON OROGRAPHICS COULD HELP SPARK
SOME CONVECTION IN THE AFTERNOON. HIGHS FOR MONDAY WILL INCREASE
SLIGHTLY FROM SUNDAY INTO THE MID 80S.
TUESDAY AND WEDNESDAY...THE UPPER LEVEL RIDGE THAT IS DOMINATING THE
SOUTHERN PORTIONS OF THE CONUS WILL START TO BREAK DOWN AND MOVE
SOUTH ONCE AGAIN INCREASING SUBTROPICAL MOISTURE OVER THE REGION
TUESDAY AFTERNOON INTO WEDNESDAY. THERE WILL BE INCREASED STORM
COVERAGE TUESDAY AND WEDNESDAY AFTERNOONS. CAPE VALUES ARE NOT
IMPRESSIVE BUT SOME BRIEF HEAVY RAIN AND HIGH WINDS WILL BE POSSIBLE
WITH STORM DEVELOPMENT.
THURSDAY INTO THE START OF THE WEEKEND...MODELS ARE SHOWING A DRIER
AND WARMER PATTERN TAKING PLACE. TEMPERATURES WILL INCREASE INTO THE
LOWER 90S BY THE END OF THE WEEK. WILL KEEP A SLIGHT CHANCE OF
STORMS IN THE MOUNTAINS BUT AT THIS POINT DO NOT SEE MUCH POTENTIAL
FOR DEVELOPMENT OVER THE PLAINS.
&&
.AVIATION...(FOR THE TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 308 AM MDT SAT JUL 18 2015
WITHIN THE NEXT HOUR SURFACE WINDS WILL BECOME EASTERLY TURNING
SOUTHEASTLY THIS AFTERNOON. THUNDERSTORMS WILL DEVELOP OVER THE
HIGH TERRAIN AFTER 17Z...AND SPREAD TO THE LOWER ELEVATIONS AFTER
21Z. RIGHT NOW IT LOOKS LIKE SEVERE WEATHER WILL BE OVER THE FAR
NORTHEAST PLAINS...BUT THUNDERSTORMS COULD PRODUCE GUSTY OUTFLOW
WINDS TO 45 MPH THIS BETWEEN 21Z AND 02Z. AFTER 09Z TONIGHT AREAS
OF LOW STRATUS AND PATCHY FOG SHOULD DEVELOP OVER MUCH OF THE
AREA. IF THIS DEVELOPS EXPECT IFR CEILINGS THAT WILL LINGER UNTIL
MID MORNING SUNDAY.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...RTG
SHORT TERM...RPK
LONG TERM...BOWEN
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
309 AM MDT SAT JUL 18 2015
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 308 AM MDT SAT JUL 18 2015
SWLY FLOW ALOFT WILL BE OVER THE AREA TODAY THRU TONIGHT. AT THE
SFC A WK SURGE MOVED ACROSS NERN CO LAST EVENING BUT HAS PRETTY
MIXED OUT THE LAST FEW HOURS. OVERALL AM GETTING CONFLICTING
SIGNALS ON HOW THE SFC PTRN IS GOING TO EVOLVE THIS AFTN. THE NAM
AND HIRES MODEL WANT TO BRING ANOTHER SURGE INTO NERN CO BY MIDDAY
WHILE THE HRRR AND RAP KEEP THIS BNDRY FURTHER NORTH OVER SERN WY
AND WRN NE THRU THE AFTN HOURS. AS A RESULT DEWPOINTS MIX OUT INTO
THE 30S AND 40S IN THE RAP AND HRRR WHILE THE NAM AND HIRES KEEP
THEM IN THE 50S. FURTHERMORE THIS LEADS TO LARGE DIFFERENCES IN
FCST CAPE BY MID TO AFTN WITH 2000 J/KG OR MORE ACROSS NERN CO AS
SHOWN BY THE NAM WITH 500-1000 J/KG IN THE HRRR AND RAP. ANOTHER
PROBLEM TO CONSIDER IS THAT EVEN IF THE NAM IS CORRECT WITH THE MUCH
HIGHER CAPE VALUES IT HAS A DECENT CAP IN PLACE THRU THE AFTN ACROSS
ALL OF NERN CO. IN ADDITION THERE IS SOME MID LVL DESCENT SHOWN AS
WELL THRU THE AFTN HOURS WHICH COULD LIMIT TSTM ACTIVITY AS WELL.
AT THIS POINT THERE ARE SO MANY CONFLICTING SIGNALS EVEN IF I ADJUST
THINGS I COULD GO IN THE WRONG DIRECTION SO WILL LEAVE INHERITED
POPS ALONE FOR THE AFTN HOURS. NATURALLY IF THE HIGHER CAPE VALUES
ARE IN PLACE AND THE CAP IS BKN THERE WOULD CERTAINLY BE THE
POTENTIAL FOR SOME SVR STORMS DUE TO FAVORABLE SHEAR. CIPS GUIDANCE
SHOWS THE HIGHEST POTENTIAL OVER THE NERN PLAINS MAINLY NE OF A LINE
FROM BRIGGSDALE TO WIGGINS TO LAST CHANCE.
OVER THE HIGHER TERRAIN STORMS WILL BE HIGH BASED AND PRODUCE GUSTY
WINDS BUT LIMITED RAINFALL. MEANWHILE ANOTHER PROBLEM FOR TODAY IS
HIGH TEMPERATURES. DEPENDING ON THE TIMING OF THE COOL FNT HIGHS
COULD EASILY RISE BACK INTO THE LOWER TO MID 90S ACROSS NERN CO IF
THE FNT IS SLOWER LIKE THE RAP/HRRR SHOW. FOR NOW WILL KEEP
READINGS IN THE MID 80S TO NR 90 HOWEVER THEY MAY END UP BEING TOO
COOL.
FOR THIS EVENING LOW LVL MOISTURE WILL INCREASE OVER THE PLAINS
BEHIN THE COOL FNT AS SOME WK MID LVL ASCENT MOVE ACROSS. THIS
SHOULD LEAD TO A BETTER CHC OF STORMS ACROSS NERN CO WITH SOME OF
THE ACTIVITY POSSIBLY LINGERING AFTER MIDNIGHT OVER THE FAR NERN
PLAINS. ONCE AGAIN THERE WILL BE THE POTENTIAL FOR A FEW SVR
STORMS ALONG WITH SOME HEAVY RAINFALL WELL DUE TO INCREASING
PRECIPITABLE WATER VALUES. LATE TONIGHT WITH SEE AREAS OF STRATUS
DVLP OVER MUCH OF NERN CO DUE TO UPSLOPE FLOW AND INCREASING LOW
LVL MOISTURE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 308 AM MDT SAT JUL 18 2015
INCREASED MOISTURE THROUGH THE BEGINNING OF THE WEEK WILL INCREASE
CONVECTION WITH SLIGHTLY BELOW AVERAGE TEMPERATURES. LOOK FOR DRIER
AND WARMER CONDITIONS TOWARD THE END OF THE WEEK.
SUNDAY WILL BRING MOSTLY CLOUDY CONDITIONS WITH SLIGHTLY COOLER
TEMPERATURES DUE IN PART TO A FRONT THAT WILL PUSH THROUGH THE
REGION EARLIER IN THE MORNING. MOISTURE PW VALUES WILL INCREASE ABOVE
1 INCH WITH ENHANCED UPSLOPE FLOW. WARMING AND THEREFORE CONVECTION
WILL BE INHIBITED THROUGH THE DAY BY CLOUD COVER AND MID LEVEL
STABILITY. WILL MAINTAIN SCATTERED STORMS OVER THE MOUNTAINS WITH
ONLY ISOLATED ON THE PLAINS TOWARD THE LATE AFTERNOON AND EVENING.
MAIN THREATS WILL BE HEAVY RAIN AND WINDS WITH THE STORMS.
SUNDAY NIGHT INTO MONDAY WILL SEE STORMS CONTINUING INTO EARLY
MORNING BEFORE DISSIPATING. WESTERLY UPPER LEVEL FLOW INCREASES WITH
A SLIGHT DROP IN PW VALUES AS THE MOISTURE GETS CUTS OFF.
HOWEVER...WITH LINGERING MOISTURE IN THE MOUNTAINS WILL MAINTAIN
INCREASED POPS FOR MONDAY AS AFTERNOON OROGRAPHICS COULD HELP SPARK
SOME CONVECTION IN THE AFTERNOON. HIGHS FOR MONDAY WILL INCREASE
SLIGHTLY FROM SUNDAY INTO THE MID 80S.
TUESDAY AND WEDNESDAY...THE UPPER LEVEL RIDGE THAT IS DOMINATING THE
SOUTHERN PORTIONS OF THE CONUS WILL START TO BREAK DOWN AND MOVE
SOUTH ONCE AGAIN INCREASING SUBTROPICAL MOISTURE OVER THE REGION
TUESDAY AFTERNOON INTO WEDNESDAY. THERE WILL BE INCREASED STORM
COVERAGE TUESDAY AND WEDNESDAY AFTERNOONS. CAPE VALUES ARE NOT
IMPRESSIVE BUT SOME BRIEF HEAVY RAIN AND HIGH WINDS WILL BE POSSIBLE
WITH STORM DEVELOPMENT.
THURSDAY INTO THE START OF THE WEEKEND...MODELS ARE SHOWING A DRIER
AND WARMER PATTERN TAKING PLACE. TEMPERATURES WILL INCREASE INTO THE
LOWER 90S BY THE END OF THE WEEK. WILL KEEP A SLIGHT CHANCE OF
STORMS IN THE MOUNTAINS BUT AT THIS POINT DO NOT SEE MUCH POTENTIAL
FOR DEVELOPMENT OVER THE PLAINS.
&&
.AVIATION...(FOR THE TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 308 AM MDT SAT JUL 18 2015
WINDS WERE SWLY EARLY THIS MORNING HOWEVER VWP SHOWS THEM NELY JUST
ABOVE THE BNDRY LYR SO EXPECT ONCE MIXING OCCURS THEY WILL BECOME
MORE NELY BY 16Z AND THEN GRADUALLY MORE SELY BY EARLY AFTN.
CONFIDENCE IN TSTM FCST THIS AFTN NOT HIGH AS EXPLAINED ABV. IF LOW
LVL MOISTURE IS LACKING MAY SEE A FEW HIGH BASED STORMS BY 21Z WITH
GUSTY WINDS FOR A FEW HOURS. MEANWHILE DEPENDING ON TIMING OF COOL
FNT COULD SEE A BETTER CHC OF STRONGER STORMS IN THE 00Z-03Z TIME
PERIOD WITH MVFR CONDITIONS POSSIBLE. WINDS THIS EVENING SHOULD
BECOME MORE E OR NE WITH THE POTENTIAL FOR STRATUS AND SOME FOG LATE
TONIGHT INTO SUN MORNING.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RPK
LONG TERM...BOWEN
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1040 PM EDT SUN JUL 19 2015
.SYNOPSIS...
THERE IS JUST A LOW RISK FOR A FEW STRONG TO SEVERE THUNDERSTORMS
WELL AFTER MIDNIGHT. A COLD FRONT WILL DROP THROUGH NEW ENGLAND
MONDAY AND MAY TRIGGER SCATTERED THUNDERSTORMS NEAR THE SOUTH COAST.
A COLD FRONT SWEEPS THROUGH THE REGION TUESDAY. HIGH PRESSURE BUILDS
OVER THE REGION FOR THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
***SEVERE THUNDERSTORM AND FLASH FLOOD WATCH HAVE BEEN CANCELLED***
***JUST A LOW RISK FOR ISOLATED STRONG TO SEVERE THUNDERSTORMS AFTER
2 AM***
1035 PM UPDATE...
CONVECTION HAS PRETTY MUCH COME TO AND ACROSS NORTHWEST MA AND OTHER
THAN A SPOT SHOWER OR TWO IN FAR NORTHERN MA IT WAS DRY ACROSS THE
ENTIRE REGION. IT LOOKS LIKE IT PROBABLY WILL REMAIN DRY FOR THE
NEXT SEVERAL HOURS.
HOWEVER...THERE IS ONE MORE THING WILL NEED TO WATCH AND THAT IS A
SHORTWAVE THAT WILL APPROACH FROM THE WEST AFTER 6Z. THIS RESULTS
IN SOME SUBTLE HEIGHT FALLS...BUT MOST OF THE MODELS DO NOT HAVE ANY
QPF ACROSS OUR REGION...ALTHOUGH THE LATEST 00Z NAM DOES SHOW SOME.
THE DILEMMA IS THAT THE RAP STILL MAINTAINS 1500 J/KG OF MLCAPE
AFTER 2 AM ACROSS THE REGION WITH AN EML IN PLACE. IN
ADDITION...THERE IS A SMALL WINDOW WHERE 0 TO 6 KM SHEAR INCREASES
TO 35 KNOTS WITH THIS SHORTWAVE.
SO ALL IN ALL...IT LOOKS LIKE MUCH OF OUR REGION MAY BE SPARED.
HOWEVER...GIVEN EML IN PLACE AND HIGH CAPES MAINTAINING THEMSELVES
AFTER 6Z ITS NOT COMPLETELY OUT OF THE QUESTION THAT A FEW STRONG TO
SEVERE THUNDERSTORMS. AGAIN...THIS IS A LOW RISK AND IF IT WERE TO
HAPPEN PROBABLY BETWEEN 6Z AND 12Z.
OTHERWISE...AREAS OF FOG WILL DEVELOP AND COULD BE LOCALLY DENSE IN
SOME LOCATIONS. ALREADY HAVE HAD LOW CLOUDS AND FOG ACROSS THE
ISLANDS WHICH MAY OVERSPREAD THE FAR SOUTHEAST NEW ENGLAND COAST
OVER THE NEXT FEW HOURS.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
FRONT DROPS TOWARD S COAST MON WHICH IS WHERE WE WILL HAVE CHANCE
POPS FOR AFTERNOON STORMS. MODELS SHOW FAIRLY DECENT CAPE AND
SHEAR BUT IT ALL COMES DOWN TO TIMING. STILL LOOKS LIKE A HOT DAY
BUT A LITTLE LESS HUMID THAN TODAY WITH HIGHS IN 80S.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
BIG PICTURE... ZONAL FLOW AT THE START OF THE WEEK EVOLVES
MIDWEEK AS PART OF HUDSON BAY LOW DIVES FARTHER SOUTHEAST AND
CARVES OUT A TROUGH OVER THE NORTHEAST USA. CYCLONIC FLOW LINGERS
OVER NEW ENGLAND THROUGH AT LEAST FRIDAY. A SHORTWAVE RIDGE BUILDS
IN OVER THE WEEKEND. ABOVE NORMAL HEIGHTS AT THE START OF THE WEEK
ARE SUPPRESSED BY THE TROUGH TO 100 METERS BELOW NORMAL MIDWEEK.
HEIGHTS RETURN TO NEAR NORMAL BY NEXT SUNDAY.
THE VARIOUS LONG RANGE MODEL GUIDANCE ARE IN AGREEMENT THROUGH
THE PERIOD. WE FAVOR THIS MODEL BLEND FOR THIS FORECAST.
THE DAILIES...
MONDAY NIGHT... COLD FRONT ALONG THE SOUTH COAST MOVES OFFSHORE. ANY
LINGERING SHOWERS/TSTMS SHOULD MOVE OFF AT THAT TIME. OTHERWISE FAIR
SKIES AND LIGHT WINDS THROUGH THE NIGHT...WHICH WILL ALLOW PATCHES
OF FOG TO FORM LATE AT NIGHT.
TUESDAY... SHORTWAVE APPROACHES FROM THE GREAT LAKES WHILE DRIVING A
SECOND COLD FRONT EAST INTO NEW ENGLAND. THE SUPPORTING 90-KNOT JET
APPROACHES WITH THE LEFT EXIT REGION OF THE JET IN PLACE OVERHEAD
DURING THE DAY. DAYTIME HEATING WILL SUPPORT MIXING TO 800 MB. TEMPS
AT 850 MB WILL BE AROUND 18C...MIXING FROM 800 MB YIELDS SIMILAR
RESULTS. THIS WOULD SUPPORT MAX TEMPS NEAR 90. GUIDANCE IS
SEVERAL DEGREES COOLER...SO WILL BUMP THOSE VALUES UP 2-3F TO
BRING MAX SFC VALUES IN THE UPPER 80S INLAND. STABILITY PARAMETERS
ARE FAVORABLE FOR CONVECTION WITH SBCAPE AROUND 1000/SLI AROUND
ZERO/TOTALS 45-49. THIS WILL BRING CLOUDS AND SCATTERED CONVECTION
TO THE REGION...WE WILL HAVE CHANCE POPS TUESDAY AFTERNOON WITH
THE FRONTAL PASSAGE.
WEDNESDAY THROUGH FRIDAY... UPPER TROUGH HANGS OVER THE NORTHEAST
WITH COOLER TEMPS AND MOISTURE POOL ALOFT CREATING A MORE UNSTABLE
AIRMASS WITH DAYTIME HEATING CAUSING DIURNAL CLOUDS AND POSSIBLY A
FEW LIGHT SHOWERS. SEVERAL SHORTWAVES MOVE THROUGH THE FLOW DURING
THIS PERIOD ADDING TO THE CHANCE OF CLOUDS AND SHOWERS. BEST CHANCE
FOR THIS WILL BE IN NORTHERN MASSACHUSETTS.
SATURDAY AND SUNDAY... LONGWAVE AND SHORTWAVE CONTOUR FIELDS SHOW
HIGH PRESSURE BUILDING SURFACE AND ALOFT. THIS WOULD SUGGEST FAIR
DRY WEATHER WITH TEMPERATURES NEAR NORMAL. THE GFS AND ECMWF DO
SHOW A SHORTWAVE SLIPPING THROUGH ON SUNDAY EVEN AS THE HEIGHTS
TREND HIGHER. THIS WOULD SUGGEST A CHANCE OF A FEW SHOWERS. WE WILL
MENTION A CHANCE OF A THUNDERSTORM IN WESTERN MASS SUNDAY BUT KEEP
THE REST OF THE AREA DRY.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
MODERATE CONFIDENCE.
IFR CIGS/VSBYS SPREAD BACK TOWARD CAPE COD CANAL THIS EVENING. VFR
ELSEWHERE THROUGH EARLY TONIGHT WITH AREAS MVFR/IFR DEVELOPING IN
PATCHY FOG LATE. STILL A LOW RISK FOR A FEW STRONG THUNDERSTORMS
AFTER 6Z. SLOW IMPROVEMENT TO VFR 12Z-15Z MON NEAR S COAST...CAPE
COD AND ISLANDS. SCATTERED TSTMS POSSIBLE IN THESE AREAS 18Z-23Z.
VFR ELSEWHERE.
KBOS TAF...MODERATE CONFIDENCE. MAIN TIME FRAME FOR STORMS IS 01
TO 04Z. POTENTIAL FOR 40-50KT GUSTS AND TORRENTIAL RAINFALL.
KBDL TAF...MODERATE CONFIDENCE. MAIN TIME FRAME IS 02Z TO 05Z.
POTENTIAL FOR 40-50KT GUSTS AND TORRENTIAL RAINFALL.
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...MODERATE CONFIDENCE.
MONDAY NIGHT...VFR NORTH AND TRENDING VFR SOUTH. PATCHY IFR LATE IN
FOG.
TUESDAY... VFR MOST OF THE DAY. SOME SCATTERED MVFR CIGS/VSBYS IN
SHOWERS/TSTMS ALONG AN AFTERNOON/EVENING COLD FRONT.
WEDNESDAY-THURSDAY...
VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE IN WINDS AND SEAS BELOW SCA THROUGH MON. LOW RISK
FOR A FEW STRONG STORMS AFTER MIDNIGHT.
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...MODERATE TO HIGH CONFIDENCE.
MONDAY NIGHT...LINGERING SHOWERS/TSTMS ALONG THE SOUTHERN WATERS IN
THE EVENING...DIMINISHING OVERNIGHT. AREAS OF POOR VSBYS IN FOG
TOWARD MORNING. WINDS AND SEAS WILL REMAIN BELOW SMALL CRAFT
THRESHOLDS.
TUESDAY...A COLD FRONT SWINGS ACROSS THE WATERS DURING THE LATE
AFTERNOON/EVENING WITH SCATTERED SHOWERS/TSTMS. WINDS BELOW 25
KNOTS/SEAS BELOW 5 FEET.
WEDNESDAY-THURSDAY...WINDS AND SEAS REMAIN BELOW SMALL CRAFT
THRESHOLDS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...WTB/JWD
NEAR TERM...FRANK
SHORT TERM...JWD
LONG TERM...WTB
AVIATION...FRANK/WTB/JWD
MARINE...FRANK/WTB/JWD
AREA FORECAST DISCUSSION
NWS TAUNTON MA
940 PM EDT SUN JUL 19 2015
.SYNOPSIS...
ISOLATED STRONG TO SEVERE THUNDERSTORMS WILL REMAIN POSSIBLE
OVERNIGHT. A COLD FRONT WILL DROP THROUGH NEW ENGLAND MONDAY AND
MAY TRIGGER SCATTERED THUNDERSTORMS NEAR THE SOUTH COAST. A COLD
FRONT SWEEPS THROUGH THE REGION TUESDAY. HIGH PRESSURE BUILDS OVER
THE REGION FOR THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
***LOW CONFIDENCE FORECAST OVERNIGHT***
940 PM UPDATE...
ISOLATED STRONG TO MARGINALLY SEVERE THUNDERSTORMS HAVE BEEN
CONFINED TO NORTHWEST MA SO FAR THIS EVENING. DESPITE MLCAPES
BETWEEN 2 AND 3K ALONG WITH STEEP MID LEVEL LAPSE RATES...BULK OF
FORCING HAS REMAINED TO OUR NORTH AND WEST. THEREFORE...STORMS HAVE
REALLY STRUGGLED TO GET GOING IN OUR REGION. STILL NEED TO WATCH
NORTHERN MA FOR ISOLATED STRONG TO SEVERE THUNDERSTORMS OVER THE
NEXT FEW HOURS AS THE MODELS DO SHOW SOME SUBTLE HEIGHT FALLS...BUT
CONFIDENCE IS LOW. WILL LIKELY LET THE FLASH FLOOD WATCH EXPIRE AT
10 PM...AS FLASH FLOODING FROM THIS ACTIVITY WILL PROBABLY NOT
OCCUR. MEANWHILE...DRY WEATHER WILL LIKELY PREVAIL FOR THE REST OF
THE REGION THROUGH MIDNIGHT OR EVEN A BIT AFTER
HOWEVER...THERE IS ONE MORE THING WILL NEED TO WATCH AND THAT IS A
CLUSTER OF SHOWERS AND THUNDERSTORMS IN QUEBEC. MOST OF THE MODELS
DO SHOW THE REMNANT SHORTWAVE SLIDING SOUTHEAST...ALTHOUGH MOST DO
NOT HAVE MUCH OR ANY QPF IN OUR REGION. THE TIME FRAME LOOKS TO BE
BETWEEN 6Z AND 12Z. THE HRRR HAS AT TIMES SHOWN A CLUSTER OF
SCATTERED SHOWERS AND THUNDERSTORMS WORKING ACROSS THE
REGION...WHILE OTHER TIMES NOT MUCH OF ANYTHING. RAP STILL
MAINTAINS 1500 J/KG OF MLCAPE AFTER 2 AM ACROSS MASSACHUSETTS AFTER
6Z.
SO WHILE MUCH OF THE REGION MAY BE SPARED CONVECTION...WE ARE
NOT COMPLETELY OUT OF THE WOODS AND WILL NEED TO WATCH HOW THINGS
EVOLVE INTO THE OVERNIGHT HOURS.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
FRONT DROPS TOWARD S COAST MON WHICH IS WHERE WE WILL HAVE CHANCE
POPS FOR AFTERNOON STORMS. MODELS SHOW FAIRLY DECENT CAPE AND
SHEAR BUT IT ALL COMES DOWN TO TIMING. STILL LOOKS LIKE A HOT DAY
BUT A LITTLE LESS HUMID THAN TODAY WITH HIGHS IN 80S.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
BIG PICTURE... ZONAL FLOW AT THE START OF THE WEEK EVOLVES
MIDWEEK AS PART OF HUDSON BAY LOW DIVES FARTHER SOUTHEAST AND
CARVES OUT A TROUGH OVER THE NORTHEAST USA. CYCLONIC FLOW LINGERS
OVER NEW ENGLAND THROUGH AT LEAST FRIDAY. A SHORTWAVE RIDGE BUILDS
IN OVER THE WEEKEND. ABOVE NORMAL HEIGHTS AT THE START OF THE WEEK
ARE SUPPRESSED BY THE TROUGH TO 100 METERS BELOW NORMAL MIDWEEK.
HEIGHTS RETURN TO NEAR NORMAL BY NEXT SUNDAY.
THE VARIOUS LONG RANGE MODEL GUIDANCE ARE IN AGREEMENT THROUGH
THE PERIOD. WE FAVOR THIS MODEL BLEND FOR THIS FORECAST.
THE DAILIES...
MONDAY NIGHT... COLD FRONT ALONG THE SOUTH COAST MOVES OFFSHORE. ANY
LINGERING SHOWERS/TSTMS SHOULD MOVE OFF AT THAT TIME. OTHERWISE FAIR
SKIES AND LIGHT WINDS THROUGH THE NIGHT...WHICH WILL ALLOW PATCHES
OF FOG TO FORM LATE AT NIGHT.
TUESDAY... SHORTWAVE APPROACHES FROM THE GREAT LAKES WHILE DRIVING A
SECOND COLD FRONT EAST INTO NEW ENGLAND. THE SUPPORTING 90-KNOT JET
APPROACHES WITH THE LEFT EXIT REGION OF THE JET IN PLACE OVERHEAD
DURING THE DAY. DAYTIME HEATING WILL SUPPORT MIXING TO 800 MB. TEMPS
AT 850 MB WILL BE AROUND 18C...MIXING FROM 800 MB YIELDS SIMILAR
RESULTS. THIS WOULD SUPPORT MAX TEMPS NEAR 90. GUIDANCE IS
SEVERAL DEGREES COOLER...SO WILL BUMP THOSE VALUES UP 2-3F TO
BRING MAX SFC VALUES IN THE UPPER 80S INLAND. STABILITY PARAMETERS
ARE FAVORABLE FOR CONVECTION WITH SBCAPE AROUND 1000/SLI AROUND
ZERO/TOTALS 45-49. THIS WILL BRING CLOUDS AND SCATTERED CONVECTION
TO THE REGION...WE WILL HAVE CHANCE POPS TUESDAY AFTERNOON WITH
THE FRONTAL PASSAGE.
WEDNESDAY THROUGH FRIDAY... UPPER TROUGH HANGS OVER THE NORTHEAST
WITH COOLER TEMPS AND MOISTURE POOL ALOFT CREATING A MORE UNSTABLE
AIRMASS WITH DAYTIME HEATING CAUSING DIURNAL CLOUDS AND POSSIBLY A
FEW LIGHT SHOWERS. SEVERAL SHORTWAVES MOVE THROUGH THE FLOW DURING
THIS PERIOD ADDING TO THE CHANCE OF CLOUDS AND SHOWERS. BEST CHANCE
FOR THIS WILL BE IN NORTHERN MASSACHUSETTS.
SATURDAY AND SUNDAY... LONGWAVE AND SHORTWAVE CONTOUR FIELDS SHOW
HIGH PRESSURE BUILDING SURFACE AND ALOFT. THIS WOULD SUGGEST FAIR
DRY WEATHER WITH TEMPERATURES NEAR NORMAL. THE GFS AND ECMWF DO
SHOW A SHORTWAVE SLIPPING THROUGH ON SUNDAY EVEN AS THE HEIGHTS
TREND HIGHER. THIS WOULD SUGGEST A CHANCE OF A FEW SHOWERS. WE WILL
MENTION A CHANCE OF A THUNDERSTORM IN WESTERN MASS SUNDAY BUT KEEP
THE REST OF THE AREA DRY.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
MODERATE CONFIDENCE.
IFR CIGS/VSBYS SPREAD BACK TOWARD CAPE COD CANAL THIS EVENING.
VFR ELSEWHERE THROUGH EARLY TONIGHT WITH AREAS MVFR/IFR IN
SHOWERS/TSTMS...WHICH WILL BE MORE NUMEROUS ACROSS WESTERN AND N
CENTRAL MA BUT ALSO ACROSS N CT. POTENTIAL FOR 50KT GUSTS AND
TORRENTIAL RAINFALL IN STRONGER STORMS.
SLOW IMPROVEMENT TO VFR 12Z-15Z MON NEAR S COAST...CAPE COD AND
ISLANDS. SCATTERED TSTMS POSSIBLE IN THESE AREAS 18Z-23Z. VFR
ELSEWHERE.
KBOS TAF...MODERATE CONFIDENCE. MAIN TIME FRAME FOR STORMS IS 01
TO 04Z. POTENTIAL FOR 40-50KT GUSTS AND TORRENTIAL RAINFALL.
KBDL TAF...MODERATE CONFIDENCE. MAIN TIME FRAME IS 02Z TO 05Z.
POTENTIAL FOR 40-50KT GUSTS AND TORRENTIAL RAINFALL.
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...MODERATE CONFIDENCE.
MONDAY NIGHT...VFR NORTH AND TRENDING VFR SOUTH. PATCHY IFR LATE IN
FOG.
TUESDAY... VFR MOST OF THE DAY. SOME SCATTERED MVFR CIGS/VSBYS IN
SHOWERS/TSTMS ALONG AN AFTERNOON/EVENING COLD FRONT.
WEDNESDAY-THURSDAY...
VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
*** POTENTIAL FOR STRONG OR SEVERE STORMS TOWARD EVENING ***
HIGH CONFIDENCE IN WINDS AND SEAS BELOW SCA THROUGH MON. MAIN
CONCERN IS POTENTIAL FOR STRONG TO SEVERE THUNDERSTORMS TOWARD
EVENING...WHICH MAY PRODUCE STRONG WIND GUSTS...TORRENTIAL
RAINFALL WITH POOR VISIBILITY AND DANGEROUS LIGHTNING. HIGHEST
RISK FOR THESE STORMS IS ON WATERS AROUND CAPE ANN...BUT IS ALSO
POSSIBLE ELSEWHERE.
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...MODERATE TO HIGH CONFIDENCE.
MONDAY NIGHT...LINGERING SHOWERS/TSTMS ALONG THE SOUTHERN WATERS IN
THE EVENING...DIMINISHING OVERNIGHT. AREAS OF POOR VSBYS IN FOG
TOWARD MORNING. WINDS AND SEAS WILL REMAIN BELOW SMALL CRAFT
THRESHOLDS.
TUESDAY...A COLD FRONT SWINGS ACROSS THE WATERS DURING THE LATE
AFTERNOON/EVENING WITH SCATTERED SHOWERS/TSTMS. WINDS BELOW 25
KNOTS/SEAS BELOW 5 FEET.
WEDNESDAY-THURSDAY...WINDS AND SEAS REMAIN BELOW SMALL CRAFT
THRESHOLDS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...FLASH FLOOD WATCH UNTIL 10 PM EDT THIS EVENING FOR MAZ002>004-
008-010-026.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...WTB/JWD
NEAR TERM...FRANK
SHORT TERM...JWD
LONG TERM...WTB
AVIATION...WTB/JWD
MARINE...WTB/JWD
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
936 PM EDT SUN JUL 19 2015
.DISCUSSION...
TONIGHT...THE HRRR MODEL HAS BACKED OFF GENERATING A SMALL AREA OF
SHOWERS OVER CENTRAL SECTIONS AND RADAR CONFIRMS THIS TREND.
THUNDERSTORMS THAT WERE A LITTLE TO OUR NORTH HAVE BEEN WEAKENING
TOO...SO NIGHT STABILIZATION APPEARS TO BE TAKING OVER. EXPECT THAT
GULF COAST CONVECTION WILL NOT HAVE ENOUGH PUSH TO REACH THE
INTERIOR DURING THE OVERNIGHT. THEREFORE...WILL NOT INCLUDE ANY
OVERNIGHT POPS FOR LAND AREAS. PARTLY CLOUDY SKIES AND TYPICAL
MILD/MUGGY OVERNIGHT.
PREVIOUS DISCUSSION...
MONDAY...12Z GFS/NAM MOS HAVE BACKED OFF ON POPS FOR MONDAY WITH
GFS INDICATING A RIBBON OF DRYING FROM NEAR ORLANDO TO THE CAPE
BETWEEN AREAS OF DEEPER MOISTURE ACROSS THE NRN PENINSULA AND ALSO
ACROSS SRN SECTIONS OF E CENTRAL FL. WILL TREND HIGHER RAIN
CHANCES ACROSS NRN AREAS AND FROM SRN OSCEOLA/OKEECHOBEE COUNTIES
TOWARD THE TREASURE COAST. NUDGED POPS UP FROM GFS MOS MAINLY IN
THE 40 TO 50 PCT RANGE. WITH OFFSHORE FLOW IN THE MORNING AND
CONVECTIVE DEVELOPMENT PROBABLY HOLDING OFF UNTIL LATER IN THE
AFTERNOON ACROSS CENTRAL AREAS SHOULD SEE HIGHS INTO THE LOWER
90S...WITH THE POSSIBILITY FOR SOME MID 90S IN AREAS THAT DO NOT
SEE STORMS.
TUESDAY...SFC RIDGE REMAINS NEAR THE KEYS WITH OFFSHORE FLOW FROM
THE WSW IN THE LOWER LEVELS AND INCREASING TO NEAR 20 KNOTS ACROSS
NRN SECTIONS AND 10-15 KNOTS ACROSS THE SOUTH. ANOTHER HOT DAY IS
EXPECTED WITH HIGHS INTO THE LOWER TO MID 90S AWAY FROM THE COAST
WITH A LATE DAY SEA BREEZE TRYING TO DEVELOP ALONG THE SRN
TREASURE COAST. WILL KEEP POPS IN THE SCATTERED RANGE FROM 40-50
PCT BUT MAY NEED TO LOWER SRN POPS IF OFFSHORE FLOW CAN HOLD OFF
THE SEA BREEZE AND MODEL TREND OF MID LAYER DRYING CONTINUES.
WED-SUN...12Z GUIDANCE HAS TRENDED DRIER WED ESPECIALLY ACROSS
THE SRN ZONES BEFORE DEEPER MOISTURE FROM N FL MOVES SOUTH ACROSS
THE AREA INTO THE UPCOMING WEEKEND. WILL INDICATE LOWEST RAIN
CHANCES WED WITH POPS INCREASING THU AND FRI TO SCATTERED TO
NUMEROUS ACROSS THE AREA. APPEARS SATURDAY WILL HAVE THE DEEPEST
MOISTURE OVER E CENTRAL FL WITH PWATS FROM 2.0 TO 2.2 INCHES AS
DEEP LAYER TROUGH DIGS OFF THE SE ATLC COAST. EXPECT NUMEROUS
STORMS ON SATURDAY SOME STRONG WITH LOCALLY HEAVY RAIN. LOW TO
MID LEVEL TROUGH AXIS IS FORECAST TO BE OVER E CENTRAL FL SUNDAY
AND KEEP WEATHER UNSETTLED TO END THE UPCOMING WEEKEND.
&&
.AVIATION...VFR CONDITIONS FOR THE OVERNIGHT AND EARLY MONDAY.
SCATTERED WEST TO EAST MOVING SHOWERS/STORMS EXPECTED AGAIN MON
AFTERNOON. LATEST MODEL INDICATIONS SHOW HIGHEST COVERAGE
MLB-VRB-FPR-SUA.
&&
.MARINE...
TONIGHT-MON...CONTINUED SOUTHWEST WIND FLOW. SPEEDS 10-15 KNOTS
INDICATED OCCASIONALLY...ESPECIALLY OFFSHORE. SEAS 1-2 FEET NEAR
SHORE AND 2-3 FEET WELL OFFSHORE. MAIN MARINER HAZARD WILL CONTINUE
TO BE SCATTERED STORMS MOVING OFF THE COAST MON AFTERNOON-EVENING.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECASTS...LASCODY
IMPACT WX...MOSES
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
454 AM EDT SAT JUL 18 2015
.SYNOPSIS...
08Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS MUCH OF THE SOUTHERN
TIER OF THE CONUS UNDER THE DOMAIN OF A LARGE ELONGATED REGION OF
MID/UPPER LEVEL RIDGING. THIS RIDGE IS CENTERED OVER THE LOWER MS
VALLEY...PLACING FLORIDA ON THE FAR EASTERN PERIPHERY OF THE
CIRCULATION. WV IMAGERY SHOWS ABUNDANT MID/UPPER LEVEL MOISTURE IN
PLACE OVERHEAD...AND THIS WAS CONFIRMED WITH THE 18/00Z KTBW
SOUNDING PROFILE WHICH MEASURED THE PW VALUE AT OVER 2.1". THE
PROFILE ALSO SHOWED THE DEEPER MOISTURE EXTENDING DOWN INTO THE
LOWER LEVELS OF THE TROP...WHERE THE FLOW WAS MORE WESTERLY OFF
THE GULF. OVERALL THE ATMOSPHERIC PROFILE SAMPLED LAST NIGHT AND
FORECAST THROUGH THE WEEKEND IS ONE THAT IS UNSTABLE AND CONDUCIVE
TO THE DEVELOPMENT OF NUMEROUS SHOWERS/STORMS...AND ALSO
CONDUCIVE TO HEAVY RAINFALL POTENTIAL. THEREFORE THE GREATEST
WEATHER THREAT OVER THE WEEKEND WILL BE THE POTENTIAL FOR HEAVY
RAINFALL OVER AREAS THAT HAVE ALREADY SEEN SIGNIFICANT TOTALS THE
PAST SEVERAL DAYS. FROM DAY TO DAY IT IS DIFFICULT TO DETERMINE
JUST WHERE THE BEST POTENTIAL FOR TRAINING STORMS MAY SET UP OFF
THE GULF...BUT IT IS POSSIBLE THAT ONCE THE CONVECTIVE PATTERN
BECOMES MORE CLEAR LATER THIS MORNING...THAT SIMILAR TO
FRIDAY...FLOOD WATCHES MAY BECOME NECESSARY FOR PARTS OF THE
REGION.
AS OF JUST AFTER 400 AM EDT...RADAR WAS SHOWING RENEWED SHOWER
ACTIVITY BEGINNING TO MIGRATE BACK ONSHORE INTO THE TAMPA BAY
AREA...WITH MORE NUMEROUS CONVECTION OVER THE OFFSHORE WATERS TO
THE SOUTH OF CEDAR KEY. BASED ON THE PATTERN AND ENSEMBLE
GUIDANCE...WOULD EXPECT THE TREND TO BE INCREASING COVERAGE OF
SHOWERS/STORMS DURING THE NEXT SEVERAL HOURS...ESPECIALLY NEAR THE
COAST.
&&
.SHORT TERM (TODAY THROUGH SUNDAY)...
A MESSY AND SHOWERY PATTERN REMAIN IN PLACE...AND WILL REMAIN IN
PLACE THROUGH THE WEEKEND. MUCH OF THE REGION RESIDES UNDER AN
ENVIRONMENT OF DEEP LAYER MOISTURE WITH A LOW LEVEL FLOW FROM THE
WEST/SOUTHWEST OFF THE GULF OF MEXICO. THIS PATTERN IS FAVORABLE
FOR SCT-NMRS SHOWERS AND STORMS TO DEVELOP EARLY IN THE MORNING
OVER THE COASTAL WATERS AND MIGRATE ONSHORE THROUGHOUT THE
MORNING. DIURNAL HEATING AND OUTFLOW FROM THE MORNING COASTAL
CONVECTION THEN GETS CONVECTION GOING BY MIDDAY (IF NOT
BEFORE) OVER THE INTERIOR ZONES. THERE WILL BE SOME DRIER AIR
ABOVE THE SURFACE TRYING TO ADVECT DOWN TOWARD THE NORTHERN NATURE
COAST...BUT IT APPEARS THAT THIS PUSH WILL STALL JUST TO OUR
NORTH...OR POSSIBLY SNEAK FAR ENOUGH SOUTH TO DECREASE THE RAIN
CHANCES FOR LEVY COUNTY. ELSEWHERE...WE ARE IN THE MOISTURE AND
THE FORECAST WILL BE FOR OFF AND ON SHOWERS.
AS MENTIONED ABOVE...THE PW VALUES ACROSS THE REGION ON FAIRLY
HIGH. THE 00Z KTBW SOUNDING SHOWED A PW VALUE OVER THE 90TH
PERCENTILE OF VALUES FOR THE MIDDLE OF JULY...AND MANY OF THE
GUIDANCE MEMBERS SHOW THIS VALUE INCREASING FURTHER TODAY.
THEREFORE...THE POTENTIAL IS THERE FOR SOME OF THE SHOWERS TO
PRODUCE VERY HEAVY RAINFALL...ESPECIALLY IF WE END UP WITH ANY
TRAINING BANDS OF STORMS...WHICH DO TEND TO BE FAVORED WITHIN THE
OBSERVED SOUTHWEST FLOW. LOCATIONS THAT ARE UNLUCKY ENOUGH TO END
UP UNDER ONE OF THESE BANDS CAN QUICKLY ACCUMULATE SEVERAL INCHES
OF RAINFALL AND SEE LOCALIZED FLOODING. RADAR TREND WILL BE
MONITORED CLOSELY THROUGH THE DAY FOR THIS POTENTIAL.
THINGS WILL TEND TO DRY OUT FOR A WHILE DURING THE LATER EVENING
HOURS TONIGHT BEFORE WE ONCE AGAIN SEE SHOWERS DEVELOPING OVER THE
EASTERN GULF AND MIGRATING TOWARD THE COAST IN THE PRE-DAWN HOURS.
MUCH OF THE AREA SHOULD BE ONCE AGAIN DODGING OFF AND ON SHOWERS
FOR SUNDAY WITH LIKELY POPS AS SOME POINT DURING THE DAY. SUNDAY
WILL BE THE DAY WHERE SOME POTENTIAL FOR DRIER AIR MAY TRY AND
SETTLE DOWN INTO THE NORTHERN NATURE COAST...AND MAY BE ABLE TO
LOWER POPS FURTHER FOR LEVY COUNTY AS CONFIDENCE IN THE SOUTHWARD
EXTENT OF DRIER AIR ALOFT INCREASES. SIMILAR TO TODAY...THE
HIGHEST RAIN CHANCES NEAR THE COAST WILL BE IN THE MORNING...WITH
THE HIGHEST RAIN CHANCES MIGRATING TO THE INLAND ZONES FOR THE
SECOND HALF OF THE DAY.
THE HIGHER COVERAGE OF SHOWERS AND CLOUDS WILL TEND TO KEEP
TEMPERATURES DOWN THIS WEEKEND. THOSE AREA THAT SEE SEVERAL ROUNDS
OF SHOWERS WILL LIKELY HOLD IN THE 80S. SO WILL SAY DAYTIME TEMPS
AT OR BELOW NORMAL THROUGH THE WEEKEND...WITH OVERNIGHT LOWS RIGHT
ABOUT WHERE THEY SHOULD BE FOR THE MIDDLE OF JULY.
FINAL NOTE...THE PERSISTENT SOUTHWESTERLY FLOW OVER THE EASTERN
GULF OF MEXICO HAS THE BUOYS OFFSHORE RUNNING AROUND 3 FEET EARLY
THIS MORNING. THESE VALUES HAVE BEEN SHOWN TO BE SUFFICIENT FOR AN
ENHANCED RIP CURRENT RISK DURING SOUTHWEST FLOW AND WILL ISSUE A
HIGH RISK OF RIP CURRENTS FOR BEACHES SOUTH OF TARPON SPRINGS
THROUGH THIS EVENING.
&&
.LONG TERM (SUNDAY NIGHT - FRIDAY)...
THE OVERALL PATTERN DURING THE LONG TERM PERIOD WILL NOT SEE
SIGNIFICANT CHANGE FROM DAY TO DAY...WITH A BROAD UPPER LEVEL RIDGE
CENTERED OVER THE GULF COAST...AND THE SURFACE SUBTROPICAL RIDGE
AXIS HANGING AROUND THE FLORIDA STRAITS. AS A RESULT...PERSISTENT
SOUTHWESTERLY TO WESTERLY LOW LEVEL FLOW LOOKS LIKELY TO REMAIN IN
CONTROL OF THE AREA THROUGH THE END OF NEXT WEEK. SOUTHWEST FLOW
TYPICALLY BRINGS SHOWERS AND THUNDERSTORMS DEVELOPING OVER THE GULF
DURING THE OVERNIGHT AND MORNING HOURS AND MOVING INTO THE COAST
DURING THE MORNING AND AFTERNOON. AREAS FARTHER INLAND GENERALLY DO
NOT SEE THEIR HIGHEST STORM COVERAGE UNTIL LATE IN THE AFTERNOON AND
EARLY EVENING. THUNDERSTORMS WILL DIE DOWN A COUPLE HOURS AFTER
SUNSET...BEFORE THE PATTERN REPEATS WITH FRESH STORMS DEVELOPING
OVER THE GULF SHORTLY THEREAFTER. WITH THIS STAGNANT PATTERN...SOME
AREAS ALONG THE COAST CAN EASILY SEE PERIODS OF HEAVY RAINFALL
REPEATED MULTIPLE DAYS...INCREASING THE RISK OF FLOODING.
MOISTURE WILL BE READILY AVAILABLE...WITH MODEL PRECIPITABLE WATER
VALUES FORECAST TO REMAIN BETWEEN 1.75 AND 2.25 INCHES THROUGH THE
PERIOD. NOT ONLY WILL THIS ALLOW FOR THE WET PATTERN TO
CONTINUE...BUT WILL ALSO KEEP SKIES A BIT CLOUDIER THAN USUAL FOR
LATE JULY. AS A RESULT HIGH TEMPERATURES MAY HAVE A HARD TIME
REACHING GUIDANCE...ALTHOUGH A BRIEF BREAK IN THE CLOUDS DURING THE
AFTERNOON WILL BE SUFFICIENT TO LET TEMPERATURES SOAR. IN
GENERAL...HIGHS ARE EXPECTED TO RANGE FROM THE MID 80S TO AROUND 90
EACH DAY...WITH LOWS EACH MORNING GENERALLY IN THE 70S.
&&
.AVIATION...
GENERAL VFR CONDITIONS ARE OBSERVED ACROSS THE REGION EARLY THIS
MORNING UNDER A DECAYING CIRRUS SHIELD FROM THE CONVECTION ON
FRIDAY. NEW SHOWERS/STORMS ARE ALREADY FORMING AND PUSHING ONSHORE
FROM TAMPA DOWN TOWARD FORT MYERS. EXPECT THE TERMINALS TO BE IN
AND OUT OF SHOWERS/STORMS THROUGH THE DAY...WITH THE POTENTIAL FOR
THE MOST WIDESPREAD SHOWER ACTIVITY THIS MORNING OCCURRING FROM
KTPA/KPIE DOWN TO KSRQ.
&&
.MARINE...
THE FORECAST WATERS WILL REMAIN BETWEEN A WEAK TROUGH OF LOW
PRESSURE TO OUR NORTH...AND THE SUBTROPICAL SURFACE RIDGE TO OUR
SOUTH THROUGH THE EARLY PORTION OF NEXT WEEK. THIS PATTERN WILL
CONTINUE TO PROVIDE THE REGION WITH A LARGE SCALE SOUTHWEST FLOW.
ALTHOUGH WINDS AND SEAS ARE EXPECTED TO GENERALLY REMAIN BELOW
HEADLINE CRITERIA...SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS WILL CREATE LOCALLY HIGHER WIND GUSTS AND ROUGHER
SEAS.
&&
.FIRE WEATHER...
ABUNDANT LOW LEVEL MOISTURE AND ABOVE NORMAL RAIN CHANCES WILL
PREVENT ANY SIGNIFICANT FIRE WEATHER CONCERNS THROUGH THE WEEKEND.
RELATIVE HUMIDITY VALUES WILL REMAIN WELL ABOVE CRITICAL LEVELS.
FOG POTENTIAL...NO SIGNIFICANT FOG IS ANTICIPATED THROUGH THE
WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 89 78 89 78 / 70 40 60 30
FMY 91 76 91 76 / 50 40 60 30
GIF 91 75 91 75 / 70 50 60 30
SRQ 87 78 88 77 / 70 50 60 30
BKV 89 74 90 74 / 70 40 60 30
SPG 88 79 89 79 / 70 40 60 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH THIS EVENING FOR COASTAL
CHARLOTTE-COASTAL LEE-COASTAL MANATEE-COASTAL
SARASOTA-PINELLAS.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WEATHER...MROCZKA
LONG TERM...FLEMING
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
624 AM EDT SAT JUL 18 2015
.SYNOPSIS...
A SURFACE PRESSURE TROUGH WILL BE IN THE FORECAST AREA THROUGH
SUNDAY. ALOFT...HIGH PRESSURE WILL EXTEND INTO THE AREA FROM THE
SOUTHERN PLAINS. THE PATTERN WILL BRING ABOVE NORMAL TEMPERATURES
WITH SCATTERED MAINLY DIURNAL THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE MID-LEVEL SHORTWAVE TROUGH SHOWN BY THE WATER VAPOR IMAGERY
OVER THE OHIO VALLEY EARLY THIS MORNING SHOULD HELP WEAKEN THE
RIDGING EXTENDING INTO THE FORECAST AREA FROM THE SOUTHERN
PLAINS...ESPECIALLY IN THE NORTH PART OF THE FORECAST AREA.
EXPECT AN INCREASE IN MOISTURE AND INSTABILITY ASSOCIATED WITH
THIS UPPER FEATURE. THERE WILL ALSO BE SOME CONVERGENCE INTO THE
LEE-SIDE TROUGH IN THE FORECAST AREA. THE HRRR AND ARW DISPLAYED
THUNDERSTORMS MOVING INTO THE NORTH PART OF THE FORECAST AREA
DURING THE MID TO LATE AFTERNOON WITH A SOUTHEASTWARD MOVEMENT.
THE HIGH-RESOLUTION MODELS HAD CONSIDERABLE COVERAGE IN THE NORTH
SECTION BUT LESS COVERAGE IN THE REST OF THE AREA DURING THE
AFTERNOON INTO THE EVENING. BASED ON THE INITIAL DRYNESS AND
LINGERING UPPER RIDGING THUNDERSTORM COVERAGE MAY REMAIN LIMITED.
WE FORECASTED THE HIGHER CHANCE IN THE NORTH PART BASED ON THE
HIGH-RESOLUTION MODELS AND MORE PRONOUNCED INFLUENCE OF THE MID-
LEVEL SHORTWAVE TROUGH. THE NAM INDICATED SURFACE-BASED LI/S -6 TO
-7 TODAY. THE MODERATE INSTABILITY WITH AN INVERTED-V TYPE
SOUNDING INDICATES A POSSIBILITY OF DAMAGING WIND WITH A FEW OF
THE THUNDERSTORMS. LEANED TOWARD THE WARMER TEMPERATURE GUIDANCE
BASED ON THE DRY ENVIRONMENT AND RECENT BIAS.
THUNDERSTORM COVERAGE SHOULD DIMINISH TONIGHT WITH THE LOSS OF
HEATING. THE GUIDANCE WAS CLOSE WITH LOWS MAINLY IN THE MIDDLE
70S.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
THE MODELS DISPLAY A LEE-SIDE TROUGH IN THE FORECAST AREA. STRONG
HEATING WITH CONVERGENCE INTO THIS FEATURE SUPPORTS THUNDERSTORMS...
BUT UPPER RIDGING EXTENDING INTO THE AREA FROM THE WEST SHOULD
LIMIT COVERAGE. USED THE GUIDANCE CONSENSUS FOR THE POP FORECAST.
THE GUIDANCE WAS CLOSE WITH THE TEMPERATURES. IT WILL REMAIN HOT
WITH HIGHS NEAR 100 SUNDAY.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
THE MEDIUM-RANGE MODELS DISPLAY UPPER-LEVEL RIDGING ALONG THE
SOUTHERN TIER OF THE NATION BUT THE RIDGING APPEARS SOMEWHAT
WEAKER OVER THE FORECAST AREA. THE MODELS SHOW LEE-SIDE TROUGHING
DURING MUCH OF THE PERIOD. A PRE-FRONTAL TROUGH OR FRONT MAY ALSO
STALL NEAR THE AREA DURING THE MIDDLE OF THE WEEK. THE PATTERN
SUPPORTS ABOVE NORMAL TEMPERATURES WITH SCATTERED THUNDERSTORMS.
THE GFS...ECMWF...AND EKD MOS HAVE TEMPERATURES MAINLY 4 TO 8
DEGREES ABOVE NORMAL WITH POPS 10 TO 40 PERCENT DURING THE PERIOD.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
EXPECTED STRATUS AND LIGHT IMPROVING TO VFR BY 15Z. WINDS WILL BE
LIGHT AND VARIABLE IN WEAK PRESSURE PATTERN ALTHOUGH A WEAK
SURFACE TROUGH MAY DEVELOP OVER THE MIDLANDS BY THIS AFTERNOON.
MODELS INDICATING SCATTERED CONVECTION DEVELOPING LATER THIS
AFTERNOON...BUT LOW CONFIDENCE IN TIMING AND AREAL COVERAGE SO
WILL LEAVE OUT OF TAFS AT THIS TIME.
EXTENDED AVIATION OUTLOOK...BRIEF MVFR/IFR POSSIBLE SUNDAY THROUGH
WEDNESDAY IN DIURNALLY DRIVEN CONVECTION. FOG/STRATUS POSSIBLE EACH
MORNING.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
613 AM EDT SAT JUL 18 2015
.SYNOPSIS...
A SURFACE PRESSURE TROUGH WILL BE IN THE FORECAST AREA THROUGH
SUNDAY. ALOFT...HIGH PRESSURE WILL EXTEND INTO THE AREA FROM THE
SOUTHERN PLAINS. THE PATTERN WILL BRING ABOVE NORMAL TEMPERATURES
WITH SCATTERED MAINLY DIURNAL THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE MID-LEVEL SHORTWAVE TROUGH SHOWN BY THE WATER VAPOR IMAGERY
OVER THE OHIO VALLEY EARLY THIS MORNING SHOULD HELP WEAKEN THE
RIDGING EXTENDING INTO THE FORECAST AREA FROM THE SOUTHERN
PLAINS...ESPECIALLY IN THE NORTH PART OF THE FORECAST AREA.
EXPECT AN INCREASE IN MOISTURE AND INSTABILITY ASSOCIATED WITH
THIS UPPER FEATURE. THERE WILL ALSO BE SOME CONVERGENCE INTO THE
LEE-SIDE TROUGH IN THE FORECAST AREA. THE HRRR AND ARW DISPLAYED
THUNDERSTORMS MOVING INTO THE NORTH PART OF THE FORECAST AREA
DURING THE MID TO LATE AFTERNOON WITH A SOUTHEASTWARD MOVEMENT.
THE HIGH-RESOLUTION MODELS HAD CONSIDERABLE COVERAGE IN THE NORTH
SECTION BUT LESS COVERAGE IN THE REST OF THE AREA DURING THE
AFTERNOON INTO THE EVENING. BASED ON THE INITIAL DRYNESS AND
LINGERING UPPER RIDGING THUNDERSTORM COVERAGE MAY REMAIN LIMITED.
WE FORECASTED THE HIGHER CHANCE IN THE NORTH PART BASED ON THE
HIGH-RESOLUTION MODELS AND MORE PRONOUNCED INFLUENCE OF THE MID-
LEVEL SHORTWAVE TROUGH. THE NAM INDICATED SURFACE-BASED LI/S -6 TO
-7 TODAY. THE MODERATE INSTABILITY WITH AN INVERTED-V TYPE
SOUNDING INDICATES A POSSIBILITY OF DAMAGING WIND WITH A FEW OF
THE THUNDERSTORMS. LEANED TOWARD THE WARMER TEMPERATURE GUIDANCE
BASED ON THE DRY ENVIRONMENT AND RECENT BIAS.
THUNDERSTORM COVERAGE SHOULD DIMINISH TONIGHT WITH THE LOSS OF
HEATING. THE GUIDANCE WAS CLOSE WITH LOWS MAINLY IN THE MIDDLE
70S.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
THE MODELS DISPLAY A LEE-SIDE TROUGH IN THE FORECAST AREA. STRONG
HEATING WITH CONVERGENCE INTO THIS FEATURE SUPPORTS THUNDERSTORMS...
BUT UPPER RIDGING EXTENDING INTO THE AREA FROM THE WEST SHOULD
LIMIT COVERAGE. USED THE GUIDANCE CONSENSUS FOR THE POP FORECAST.
THE GUIDANCE WAS CLOSE WITH THE TEMPERATURES. IT WILL REMAIN HOT
WITH HIGHS NEAR 100 SUNDAY.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
THE MEDIUM-RANGE MODELS DISPLAY UPPER-LEVEL RIDGING ALONG THE
SOUTHERN TIER OF THE NATION BUT THE RIDGING APPEARS SOMEWHAT
WEAKER OVER THE FORECAST AREA. THE MODELS SHOW LEE-SIDE TROUGHING
DURING MUCH OF THE PERIOD. A PRE-FRONTAL TROUGH OR FRONT MAY ALSO
STALL NEAR THE AREA DURING THE MIDDLE OF THE WEEK. THE PATTERN
SUPPORTS ABOVE NORMAL TEMPERATURES WITH SCATTERED THUNDERSTORMS.
THE GFS...ECMWF...AND EKD MOS HAVE TEMPERATURES MAINLY 4 TO 8
DEGREES ABOVE NORMAL WITH POPS 10 TO 40 PERCENT DURING THE PERIOD.
&&
.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
EXPECTED STRATUS AND LIGHT FOG 09Z-14Z IMPROVING TO VFR BY 16Z.
WINDS WILL BE LIGHT AND VARIABLE IN WEAK PRESSURE PATTERN ALTHOUGH A
WEAK SURFACE TROUGH MAY DEVELOP OVER THE MIDLANDS BY THIS AFTERNOON.
MODELS INDICATING SCATTERED CONVECTION DEVELOPING LATER THIS
AFTERNOON...BUT LOW CONFIDENCE IN TIMING AND AREAL COVERAGE SO WILL
LEAVE OUT OF TAFS AT THIS TIME.
EXTENDED AVIATION OUTLOOK...BRIEF MVFR/IFR POSSIBLE SUNDAY THROUGH
WEDNESDAY IN DIURNALLY DRIVEN CONVECTION. FOG/STRATUS POSSIBLE EACH
MORNING.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
430 AM EDT SAT JUL 18 2015
.SYNOPSIS...
A SURFACE PRESSURE TROUGH WILL BE IN THE FORECAST AREA THROUGH
SUNDAY. ALOFT...HIGH PRESSURE WILL EXTEND INTO THE AREA FROM THE
SOUTHERN PLAINS. THE PATTERN WILL BRING ABOVE NORMAL TEMPERATURES
WITH SCATTERED MAINLY DIURNAL THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE MID-LEVEL SHORTWAVE TROUGH SHOWN BY THE WATER VAPOR IMAGERY
OVER THE OHIO VALLEY EARLY THIS MORNING SHOULD HELP WEAKEN THE
RIDGING EXTENDING INTO THE FORECAST AREA FROM THE SOUTHERN
PLAINS...ESPECIALLY IN THE NORTH PART OF THE FORECAST AREA.
EXPECT AN INCREASE IN MOISTURE AND INSTABILITY ASSOCIATED WITH
THIS UPPER FEATURE. THERE WILL ALSO BE SOME CONVERGENCE INTO THE
LEE-SIDE TROUGH IN THE FORECAST AREA. THE HRRR AND ARW DISPLAYED
THUNDERSTORMS MOVING INTO THE NORTH PART OF THE FORECAST AREA
DURING THE MID TO LATE AFTERNOON WITH A SOUTHEASTWARD MOVEMENT.
THE HIGH-RESOLUTION MODELS HAD CONSIDERABLE COVERAGE IN THE NORTH
SECTION BUT LESS COVERAGE IN THE REST OF THE AREA DURING THE
AFTERNOON INTO THE EVENING. BASED ON THE INITIAL DRYNESS AND
LINGERING UPPER RIDGING THUNDERSTORM COVERAGE MAY REMAIN LIMITED.
WE FORECASTED THE HIGHER CHANCE IN THE NORTH PART BASED ON THE
HIGH-RESOLUTION MODELS AND MORE PRONOUNCED INFLUENCE OF THE MID-
LEVEL SHORTWAVE TROUGH. THE NAM INDICATED SURFACE-BASED LI/S -6 TO
-7 TODAY. THE MODERATE INSTABILITY WITH AN INVERTED-V TYPE
SOUNDING INDICATES A POSSIBILITY OF DAMAGING WIND WITH A FEW OF
THE THUNDERSTORMS. LEANED TOWARD THE WARMER TEMPERATURE GUIDANCE
BASED ON THE DRY ENVIRONMENT AND RECENT BIAS.
THUNDERSTORM COVERAGE SHOULD DIMINISH TONIGHT WITH THE LOSS OF
HEATING. THE GUIDANCE WAS CLOSE WITH LOWS MAINLY IN THE MIDDLE
70S.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
THE MODELS DISPLAY A LEE-SIDE TROUGH IN THE FORECAST AREA. STRONG
HEATING WITH CONVERGENCE INTO THIS FEATURE SUPPORTS THUNDERSTORMS...
BUT UPPER RIDGING EXTENDING INTO THE AREA FROM THE WEST SHOULD
LIMIT COVERAGE. USED THE GUIDANCE CONSENSUS FOR THE POP FORECAST.
THE GUIDANCE WAS CLOSE WITH THE TEMPERATURES. IT WILL REMAIN HOT
WITH HIGHS NEAR 100 SUNDAY.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
THE MEDIUM-RANGE MODELS DISPLAY UPPER-LEVEL RIDGING ALONG THE
SOUTHERN TIER OF THE NATION BUT THE RIDGING APPEARS SOMEWHAT
WEAKER OVER THE FORECAST AREA. THE MODELS SHOW LEE-SIDE TROUGHING
DURING MUCH OF THE PERIOD. A PRE-FRONTAL TROUGH MAY ALSO STALL
IN THE AREA DURING THE MIDDLE OF THE WEEK. THE PATTERN SUPPORTS
ABOVE NORMAL TEMPERATURES WITH SCATTERED THUNDERSTORMS. THE
GFS...ECMWF...AND EKD MOS HAVE TEMPERATURES MAINLY 4 TO 8 DEGREES
ABOVE NORMAL WITH POPS 10 TO 40 PERCENT DURING THE PERIOD.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
EXPECTED STRATUS AND LIGHT FOG 09Z-14Z IMPROVING TO VFR BY 16Z.
WINDS WILL BE LIGHT AND VARIABLE IN WEAK PRESSURE PATTERN ALTHOUGH A
WEAK SURFACE TROUGH MAY DEVELOP OVER THE MIDLANDS BY THIS AFTERNOON.
MODELS INDICATING SCATTERED CONVECTION DEVELOPING LATER THIS
AFTERNOON...BUT LOW CONFIDENCE IN TIMING AND AREAL COVERAGE SO WILL
LEAVE OUT OF TAFS AT THIS TIME.
EXTENDED AVIATION OUTLOOK...BRIEF MVFR/IFR POSSIBLE SUNDAY THROUGH
WEDNESDAY IN DIURNALLY DRIVEN CONVECTION. FOG/STRATUS POSSIBLE EACH
MORNING.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
205 AM EDT SAT JUL 18 2015
.SYNOPSIS...
A SURFACE PRESSURE TROUGH WILL BE IN THE FORECAST AREA THROUGH
SUNDAY. ALOFT...HIGH PRESSURE WILL EXTEND INTO THE AREA FROM THE
SOUTHERN PLAINS. THE PATTERN WILL BRING ABOVE NORMAL TEMPERATURES
WITH SCATTERED MAINLY DIURNAL THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE MID-LEVEL SHORTWAVE TROUGH SHOWN BY THE WATER VAPOR IMAGERY
OVER THE OHIO VALLEY EARLY THIS MORNING SHOULD HELP WEAKEN THE
RIDGING EXTENDING INTO THE FORECAST AREA FROM THE SOUTHERN PLAINS.
EXPECT SOME INCREASE IN MOISTURE AND INSTABILITY. THERE WILL ALSO
BE SOME CONVERGENCE INTO THE LEE-SIDE TROUGH. THE HRRR DISPLAYED
THUNDERSTORMS MOVING INTO THE NORTHWEST PART OF THE FORECAST AREA
EARLY THIS AFTERNOON WITH A SOUTHEASTWARD MOVEMENT INTO MUCH OF
THE REMAINING AREA DURING THE REST OF THE AFTERNOON. BASED ON THE
INITIAL DRYNESS AND LINGERING UPPER RIDGING THIS COVERAGE MAY BE
OVERDONE BUT WE DID LEAN TOWARD THE HIGHER GUIDANCE POPS OF AROUND
30 PERCENT. THE NAM INDICATED SURFACE-BASED LI/S -6 TO -7 TODAY.
THE MODERATE INSTABILITY WITH AN INVERTED-V TYPE SOUNDING
INDICATES A POSSIBILITY OF DAMAGING WIND WITH A FEW OF THE
THUNDERSTORMS. LEANED TOWARD THE WARMER TEMPERATURE GUIDANCE BASED
ON THE DRY ENVIRONMENT AND RECENT BIAS.
THUNDERSTORM COVERAGE SHOULD DIMINISH TONIGHT WITH THE LOSS OF
HEATING. THE GUIDANCE WAS CLOSE WITH LOWS MAINLY IN THE MIDDLE
70S.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
THE MODELS DISPLAY A LEE-SIDE TROUGH IN THE FORECAST AREA. STRONG
HEATING WITH CONVERGENCE INTO THIS FEATURE SUPPORTS THUNDERSTORMS...
BUT UPPER RIDGING EXTENDING INTO THE AREA FROM THE WEST SHOULD
LIMIT COVERAGE. USED THE GUIDANCE CONSENSUS FOR THE POP FORECAST.
THE GUIDANCE WAS CLOSE WITH THE TEMPERATURES. IT WILL REMAIN HOT
WITH HIGHS NEAR 100 SUNDAY.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
THE MEDIUM-RANGE MODELS DISPLAY UPPER-LEVEL RIDGING ALONG THE
SOUTHERN TIER OF THE NATION BUT THE RIDGING APPEARS SOMEWHAT
WEAKER OVER THE FORECAST AREA. THE MODELS SHOW LEE-SIDE TROUGHING
DURING MUCH OF THE PERIOD. A PRE-FRONTAL TROUGH MAY ALSO STALL
IN THE AREA DURING THE MIDDLE OF THE WEEK. THE PATTERN SUPPORTS
ABOVE NORMAL TEMPERATURES WITH SCATTERED THUNDERSTORMS. THE
GFS...ECMWF...AND EKD MOS HAVE TEMPERATURES MAINLY 4 TO 8 DEGREES
ABOVE NORMAL WITH POPS 10 TO 40 PERCENT DURING THE PERIOD.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
EXPECTED STRATUS AND LIGHT FOG 09Z-14Z IMPROVING TO VFR BY 16Z.
WINDS WILL BE LIGHT AND VARIABLE IN WEAK PRESSURE PATTERN ALTHOUGH A
WEAK SURFACE TROUGH MAY DEVELOP OVER THE MIDLANDS BY THIS AFTERNOON.
MODELS INDICATING SCATTERED CONVECTION DEVELOPING LATER THIS
AFTERNOON...BUT LOW CONFIDENCE IN TIMING AND AREAL COVERAGE SO WILL
LEAVE OUT OF TAFS AT THIS TIME.
EXTENDED AVIATION OUTLOOK...BRIEF MVFR/IFR POSSIBLE SUNDAY THROUGH
WEDNESDAY IN DIURNALLY DRIVEN CONVECTION. FOG/STRATUS POSSIBLE EACH
MORNING.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
554 PM CDT SAT JUL 18 2015
.MESOSCALE DISCUSSION...
324 PM CDT
MAIN COMPLEX OF THUNDERSTORMS HAS SHIFTED EAST INTO SOUTHWEST
LOWER MICHIGAN AND NORTHWEST INDIANA...HOWEVER SOME STRONGER
STORMS CONTINUE TO PULSE UP FURTHER WEST ACROSS SOUTHERN
COOK/DUPAGE/WILL COUNTIES AND STRETCHING EAST INTO NORTHWEST
INDIANA. A BOUNDARY WAS SLIDING SOUTH ACROSS KANE/DUPAGE/SOUTHERN
COOK COUNTIES...WITH CONSIDERABLE HELICITY FOCUSED ALONG THIS
FEATURE. WINDS TO THE SOUTH OF THE BOUNDARY ARE SOUTHERLY WITH A
CONSIDERABLY WARM/MOIST AIRMASS FEEDING DEW POINTS IN THE MID/UPR
70S NORTHEAST. VISIBLE IMAGERY INDICATES THE CUMULUS FIELD ALONG
AND SOUTH OF THE BOUNDARY ARE NOT GROWING VERTICALLY...HOWEVER IT
IS POSSIBLE THAT AS THE BOUNDARY MOVES INTO THIS CUMULUS LAYER
THAT ADDITIONAL GROWTH MAY OCCUR.
GIVEN HOW UNSTABLE THE ATMOSPHERE REMAINS IN THIS AREA AND
STRETCHING INTO NORTHWEST INDIANA...IT IS PLAUSIBLE THAT RAPID
GROWTH COULD OCCUR AND WITH THE ENHANCED HELICITY THE UPDRAFTS
COULD ROTATE AND PRODUCE A TORNADO OR TWO. FURTHER WEST WINDS HAVE
VEERED TO THE WEST...WHICH HAS DIMINISHED THE TOR THREAT.
SUBSIDENCE WAS BEING NOTED AS DEW POINTS HAVE FALLEN INTO THE
LOWER 70S TO A FEW UPPER 60S ACROSS FAR WESTCENTRAL IL.
BEACHLER
&&
.SHORT TERM...
227 PM CDT
A FLASH FLOOD WATCH WAS ISSUED FOR THE ENTIRE WARNING AREA DUE TO
CONCERNS ABOUT TORRENTIAL RAINFALL RATES.
OUTFLOW BOUNDARY FROM EARLIER WISCONSIN MCS HAS SAGGED SOUTH INTO
NORTHERN CWA AND IS BEGINNING TO STALL OUT OVER NORTH CENTRAL
ILLINOIS. OVER NORTHEAST ILLINOIS THE LAKE HAS AUGMENTED THE
BOUNDARY AND PROVIDED SOME ADDITIONAL SOUTHWARD ACCELERATION
ADJACENT TO LAKE MICHIGAN. ANTICIPATE THE BOUNDARY WILL STALL OUT
EVEN OVER NORTHEAST ILLINOIS AND PROBABLY RETREAT NORTH DURING THE
DAY AS SUNSHINE ALLOWS FOR STRONG HEATING/MIXING AND A MODEST
SOUTHWEST WIND DEVELOPS. DESPITE THE INITIALLY COOLER AIR NEAR THE
LAKE...STILL FEEL THERE IS A REASONABLY GOOD CHANCE THAT THE
BOUNDARY WILL STALL/RETREAT ENOUGH TO PROVIDE FOR A HOT/HUMID
AFTERNOON WITH HEAT INDICES ABOVE 100 OVER EVEN NORTHEAST ILLINOIS
SO NOT PLANNING TO CHANGE HEAT ADVISORY ANY THIS MORNING. MAY
BROADEN THE RANGE OF HEAT INDICES TO 100 TO 110 AS CLOUDS FROM
IA/MO MCS MAY LIMIT THE HEAT SOME THIS AFTERNOON...MAINLY WESTERN
CWA.
AMPLE SUNSHINE IN ADVANCE OF ANY CLOUDINESS FROM MO/IA CONVECTION
WILL ALLOW FOR RAPID HEATING AND DESTABILIZATION ACROSS THE CWA
THROUGH EARLY AFTERNOON...BUT PARTICULARLY TO THE SOUTH OF THE WI
MCS REMNANT OUTFLOW BOUNDARY. DVN/ILX MORNING SOUNDINGS BOTH SHOW
MODERATELY STEEP LOW/MID LEVEL LAPSE RATES AND AS TEMPS/DEWPOINTS
RISE TOWARD PROJECTED HIGHS REGION SHOULD BE LEFT UNCAPPED BY
EARLY AFTERNOON...WITH MODIFIED ILX SOUNDING SUPPORTING SHOWING
MLCAPE VALUES NEARING 4000 J/KG BY EARLY THIS AFTERNOON WITH SFC
PARCEL OF 90/77...WHICH APPEARS EASILY ATTAINABLE IN THE WARM
SECTOR TODAY.
MORNING UPPER AIR ANALYSIS AND ACARS DATA SHOW 35-45KT FLOW
AROUND 6KM FROM IA INTO NORTHERN ILLINOIS WHICH WILL RESULT IN
0-6KM SHEAR VALUES OF AT LEAST AROUND 30KT...WHICH COMBINED WITH
SUCH STRONG INSTABILITY WOULD SUPPORT ORGANIZED CONVECTION AND
PERHAPS EVEN A SUPERCELL THREAT...ESPECIALLY IF ANY CELLS WERE TO
RIDE OUTFLOW BOUNDARY. PRIMARY SEVERE THREAT WOULD BE LARGE HAIL
AND DAMAGING WINDS...THOUGH CANNOT COMPLETELY RULE OUT A TORNADO
THREAT WITH ANY CELLS INTERACTING WITH BOUNDARIES GIVEN THE STRONG
LOW LEVEL CAPE AND LOW LCL HEIGHTS. OBVIOUSLY STILL SITTING IN A
VERY MOIST ENVIRONMENT SO HEAVY RAINFALL AND LOCALIZED FLASH
FLOODING IS ALSO A THREAT.
PLAN TO UPDATE GRIDS SHORTLY TO INTRODUCE POPS FOR THIS AFTERNOON
SPREADING THEM FROM WEST TO EAST. GENERALLY LIKE THE TRENDS IN THE
EXPERIMENTAL HRRR WHICH SHOWS STORMS DEVELOPING IN EAST AND
NORTHEAST OF THE IA/MO DECAYING MCS AND OUTFLOW BOUNDARY. WITH
MODEL GUIDANCE ALL OVER THE PLACE AND CAMS NOT HANDLING ONGOING
SITUATION WELL CONFIDENCE IS DIMINISHED...BUT CERTAINLY
OBSERVATIONAL TRENDS SUPPORT THE ABOVE FORECAST SCENARIO AND PLAN
TO INCREASE POPS INTO THE HIGH END CHANCE RANGE FOR NOW.
DESPITE THE HIGHER STORM CHANCES TODAY...PRIOR TO ANY STORMS HEAT
INDICES ARE LIKELY TO REACH 100 TO POTENTIALLY 110 DEGREES TODAY
SO LEAVING THE HEAT HEADLINES UNCHANGED.
GRIDS ARE GOING TO TAKE A LOT OF SURGERY TO REFLECT THE ABOVE
THINKING SINCE THERE IS NO REAL GUIDANCE REFLECTING CURRENT TRENDS
OR ABOVE THINKING...BUT FORECAST UPDATES ARE FORTHCOMING.
IZZI
&&
.LONG TERM...
227 PM CDT
TOMORROW THROUGH TUESDAY...
A COLD FRONT WILL SHIFT ACROSS THE REGION ON SUNDAY. HOWEVER...IT
NOW APPEARS THAT THE BETTER THREAT FOR STRONG TO SEVERE STORMS ON
SUNDAY AFTERNOON MAY REMAIN SOUTH OF MY AREA ALL TOGETHER AS SHOWERS
AND THUNDERSTORMS TONIGHT INTO EARLY SUNDAY LOOK TO SHIFT THE MAIN
FOCUS FARTHER SOUTH THAN ORIGINALLY THOUGHT. WITH THIS IN MIND I
HAVE BACKED OFF ON POPS...ESPECIALLY SUNDAY AFTERNOON...WHEN I HAVE
FOCUSED THE HIGHEST POPS ACROSS MY EXTREME SOUTHERN COUNTIES IN
CENTRAL ILLINOIS.
ANOTHER CHANCE OF THUNDERSTORMS...WITH HEAVY RAINFALL AND POSSIBLY
STRONG WILL RETURN TO THE FORECAST ON MONDAY AS ANOTHER MID LEVEL
DISTURBANCE MOVES ACROSS THE AREA. GUIDANCE HAS NOT HAD THE BEST
HANDLE ON THIS DISTURBANCE THE PAST COUPLE OF RUNS...WITH IT
PREVIOUSLY APPEARING THAT THE MAIN THREAT OF STORMS COULD STAY SOUTH
OF THE AREA. HOWEVER...WITH THE POTENTIAL OF A FARTHER NORTH FOCUS
OF STORMS...I HAVE INCLUDED A CHANCE OF STORMS ON MONDAY...WITH
SLIGHTLY HIGHER POPS ACROSS THE SOUTHERN HALF OF THE AREA.
SURFACE HIGH PRESSURE IS EXPECTED TO BUILD OVER THE AREA ON
TUESDAY...SO IT APPEARS THAT TUESDAY COULD BE A DRY AND COOLER DAY
ACROSS THE AREA.
KJB
TUESDAY NIGHT THROUGH FRIDAY...
NORTHWEST FLOW ALOFT CONTINUES TUESDAY NIGHT THROUGH MID WEEK WITH A
FEW UPPER LEVEL WAVES MOVING THROUGH OVER THE END OF THE WEEK. AT
THE SURFACE HIGH PRESSURE SPREADS EAST OVER THE REGION TUESDAY NIGHT
AND THEN SHIFTS EAST OVER THE APPALACHIANS THURSDAY.
LOOKING AT A SHORT PERIOD OF DRY CONDITIONS THROUGH AT LEAST
WEDNESDAY NIGHT...POSSIBLY THROUGH THE END OF THE WEEK IF THE ECMWF
IS RIGHT. THE GFS FEATURES PRECIP ON THE BACKSIDE OF THE HIGH
THURSDAY NIGHT INTO FRIDAY. CONFIDENCE IS LOW SO KEPT THE CHANCE OF
PRECIP IN THE LOW END CHANCE OR LOWER RANGE.
FOR TEMPS...HAVE A SLOW WARMING TREND WITH TEMPS IN THE LOW TO MID
80S AND TEMPS COULD BE WARMER THAN FORECAST DEPENDING ON THE AMOUNT
OF PRECIP THAT OCCURS. THE GFS IS A BIT WARMER WITH 925MB TEMPS IN
THE MID TO UPPER 20S WHICH WOULD SUGGEST HIGH TEMPS IN THE 90S.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* OUTFLOW HAS MOVED SOUTH OF THE TERMMINALS... NORTH WINDS
EXPECTED TO PERSIST THROUGH 23000-2330Z BEFORE SOUTHWEST WINDS
RESTABLISH.
* TSRA EXITING THE AREA BEWTEEN 22-23Z.
* ANOTHER ROUND OF SHRA AND PERHAPS SOME EMBEDDED TSRA EARLY
SUNDAY MORNING.
ED F
//DISCUSSION...UPDATED 18Z...
A GUST FRONT FROM THE CONVECTION EARLIER THIS MORNING HAS STALLED
FROM BELVIDERE IL THROUGH HIGHLAND INDIANA. WINDS NORTHEAST OF THE
BOUNDARY ARE SLOWLY VEERING FROM NE OR E TO SE...AND EXPECTING
SOUTHWEST WINDS EARLY THIS AFTN. CONDITIONS CONTINUE TO IMPROVE
FOR STORMS. STORMS SHOULD FORM ALONG THE BOUNDARY AND AHEAD OF THE
UPPER LEVEL DISTURBANCE CURRENTLY OVER IOWA THAT IS SHIFTING EAST.
STRONG TO SEVERE STORMS ARE PROBABLE. WHILE CONFIDENCE IS MEDIUM
IN COVERAGE...TIMING...AND EXACT LOCATION...HAVE HIGH CONFIDENCE
THAT THERE SHOULD BE ENOUGH CONVECTION AROUND TO DISRUPT AIR
TRAFFIC. ALL STORMS WILL ALSO PRODUCE TORRENTIAL DOWNPOURS WHICH
WILL LIMIT VISIBILITY.
TSRA PUSHES EAST OF THE TERMINALS THIS EVENING WITH SOUTHWEST
WINDS LESS THAN 15 KT. A COLD FRONT SINKS SOUTHEAST THROUGH THE
REGION SUNDAY MORNING. SHOWERS AND A FEW EMBEDDED THUNDERSTORMS
SHOULD FORM AHEAD OF IT BUT THE NUMBER OF THUNDERSTORMS WILL BE
LIMITED BY HOW STABLE WE ARE BEHIND THIS AFTERNOON/S
THUNDERSTORMS. WINDS SHIFT TO NORTHWEST BEHIND THE COLD FRONT WITH
VFR CONDITIONS.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM TO HIGH CONFIDENCE IN WIND FORECAST.
* MEDIUM TO HIGH CONFIDENCE IN TSRA EXITING TERMINAL AREAS BY
23Z.
* MEDIUM CONFIDENCE IN COVERAGE AND TIMING OF -SHRA AND VCTS EARLY
SUNDAY MORNING.
ED F
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR. WX NIL.
MONDAY...VFR. WX NIL.
TUESDAY...SLIGHT CHANCE TSRA IN THE AFTERNOON.
WEDNESDAY...VFR. WX NIL.
THURSDAY...CHANCE TSRA.
FRIDAY...VFR/WX NIL EARLY. CHANCE TSRA OVERNIGHT.
KREIN
&&
.MARINE...
233 PM CDT
THE MAIN CONCERNS OVER LAKE MICHGAN WILL BE THE THREAT OF SEVERE
THUNDERSTORMS THIS AFTERNOON AND EVENING. CURRENTLY A LARGE AREA
OF THUNDERSTORMS DEVELOPING OVER SOUTHERN WISCONSIN AND NORTHERN
ILLINOIS AND THIS ACTIVITY WILL MOVE OVER SOUTHERN LAKE MICHIGAN
THIS AFTERNOON INTO THE EVENING. EXPECT STRONG WINDS AND LOCALLY
HIGH WAVES IN AND AROUND THE STORMS.
OTHERWISE...THINGS SHOULD QUIET DOWN ON THE LAKE BY SUNDAY
FOLLOWING A COLD FRONTAL PASSAGE.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 UNTIL 8 PM SATURDAY.
FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL MIDNIGHT SUNDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL
MIDNIGHT SUNDAY.
HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 8 PM
SATURDAY.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
518 PM CDT SAT JUL 18 2015
.MESOSCALE DISCUSSION...
324 PM CDT
THUNDERSTORMS RAPIDLY DEVELOPED ACROSS NORTH/NORTHEAST IL THIS
AFTERNOON...AS A CUMULUS FIELD BEGAN TO COLLIDE WITH THE LAKE
BOUNDARY THAT HAD PUSHED WEST. THIS CONVERGENCE ZONE ADDED TO THE
LIFT...COUPLED WITH IMPRESSIVE MLCAPE VALUES...AND PARCELS WERE
ABLE TO ASCEND RAPIDLY THROUGH A VERY MOIST AND UNSTABLE
ENVIRONMENT. JUST SOUTH OF THE CHICAGO METRO AREA DEW POINTS HAVE
POOLED TO AROUND 80 DEG THIS AFTERNOON...WITH SFC WINDS ACROSS
NORTHWEST INDIANA SLIGHTLY BACKED TO THE SOUTH.
ALONG WITH THE RAPID ASCEND OF PARCELS AND DEVELOPING
UPDRAFTS...THE CONVGENCE ZONE HAS ALSO ALLOWED FOR INCREASED LOW
LEVEL HELICITY. THIS REINFORCES THE RISK FOR SOME ROTATING
UPDRAFTS AND ISOLATED TORNADO HAZARD THIS AFTERNOON/EARLY EVENING.
THE MAIN LOCATIONS FOR THE NEXT COUPLE OF HOURS CONTINUES TO BE
THE FAR NORTHEAST IL/NORTHWEST IN AREAS...INCLUDING THE CHICAGO
METRO AREA SPILLING INTO LAKE MICHIGAN.
AS FOR CONTINUED DEVELOPMENT...HI-RES GUIDANCE DIFFERS ON HOW THE
NEXT FEW HOURS WILL UNFOLD. THE LATEST HRRR SOLUTIONS SUGGEST THE
CLUSTER ACROSS FAR NORTHEAST IL WILL SLIDE SOUTHEAST ALONG THE
CONVERGENCE ZONE AND MAINTAIN STRENGTH INTO NORTHWEST IN...WITH
LITTLE ADDITIONAL DEVELOPMENT. HOWEVER...AS ELUDED TO EARLIER
ABOUT DIFFERING SOLUTIONS RAP AND LOCAL ARW8KM SUGGEST SOME NEW
DEVELOPMENT FURTHER WEST. INVESTIGATING THE VISIBLE IMAGERY AND
THE CUMULUS FIELD WEST OF THE CURRENT CONVECTION LOOKS TO BE LESS
VERTICAL...AND POSSIBLY EVEN THINNING SLIGHTLY. DEW POINTS IN A
FEW UPSTREAM AREAS HAVE ALSO MIXED DOWN TO THE LOW 70S/UPR 60S
WITH WINDS VEERING TO THE WEST AND BECOMING MORE UNIFORM.
BEACHLER
&&
.SHORT TERM...
227 PM CDT
A FLASH FLOOD WATCH WAS ISSUED FOR THE ENTIRE WARNING AREA DUE TO
CONCERNS ABOUT TORRENTIAL RAINFALL RATES.
OUTFLOW BOUNDARY FROM EARLIER WISCONSIN MCS HAS SAGGED SOUTH INTO
NORTHERN CWA AND IS BEGINNING TO STALL OUT OVER NORTH CENTRAL
ILLINOIS. OVER NORTHEAST ILLINOIS THE LAKE HAS AUGMENTED THE
BOUNDARY AND PROVIDED SOME ADDITIONAL SOUTHWARD ACCELERATION
ADJACENT TO LAKE MICHIGAN. ANTICIPATE THE BOUNDARY WILL STALL OUT
EVEN OVER NORTHEAST ILLINOIS AND PROBABLY RETREAT NORTH DURING THE
DAY AS SUNSHINE ALLOWS FOR STRONG HEATING/MIXING AND A MODEST
SOUTHWEST WIND DEVELOPS. DESPITE THE INITIALLY COOLER AIR NEAR THE
LAKE...STILL FEEL THERE IS A REASONABLY GOOD CHANCE THAT THE
BOUNDARY WILL STALL/RETREAT ENOUGH TO PROVIDE FOR A HOT/HUMID
AFTERNOON WITH HEAT INDICES ABOVE 100 OVER EVEN NORTHEAST ILLINOIS
SO NOT PLANNING TO CHANGE HEAT ADVISORY ANY THIS MORNING. MAY
BROADEN THE RANGE OF HEAT INDICES TO 100 TO 110 AS CLOUDS FROM
IA/MO MCS MAY LIMIT THE HEAT SOME THIS AFTERNOON...MAINLY WESTERN
CWA.
AMPLE SUNSHINE IN ADVANCE OF ANY CLOUDINESS FROM MO/IA CONVECTION
WILL ALLOW FOR RAPID HEATING AND DESTABILIZATION ACROSS THE CWA
THROUGH EARLY AFTERNOON...BUT PARTICULARLY TO THE SOUTH OF THE WI
MCS REMNANT OUTFLOW BOUNDARY. DVN/ILX MORNING SOUNDINGS BOTH SHOW
MODERATELY STEEP LOW/MID LEVEL LAPSE RATES AND AS TEMPS/DEWPOINTS
RISE TOWARD PROJECTED HIGHS REGION SHOULD BE LEFT UNCAPPED BY
EARLY AFTERNOON...WITH MODIFIED ILX SOUNDING SUPPORTING SHOWING
MLCAPE VALUES NEARING 4000 J/KG BY EARLY THIS AFTERNOON WITH SFC
PARCEL OF 90/77...WHICH APPEARS EASILY ATTAINABLE IN THE WARM
SECTOR TODAY.
MORNING UPPER AIR ANALYSIS AND ACARS DATA SHOW 35-45KT FLOW
AROUND 6KM FROM IA INTO NORTHERN ILLINOIS WHICH WILL RESULT IN
0-6KM SHEAR VALUES OF AT LEAST AROUND 30KT...WHICH COMBINED WITH
SUCH STRONG INSTABILITY WOULD SUPPORT ORGANIZED CONVECTION AND
PERHAPS EVEN A SUPERCELL THREAT...ESPECIALLY IF ANY CELLS WERE TO
RIDE OUTFLOW BOUNDARY. PRIMARY SEVERE THREAT WOULD BE LARGE HAIL
AND DAMAGING WINDS...THOUGH CANNOT COMPLETELY RULE OUT A TORNADO
THREAT WITH ANY CELLS INTERACTING WITH BOUNDARIES GIVEN THE STRONG
LOW LEVEL CAPE AND LOW LCL HEIGHTS. OBVIOUSLY STILL SITTING IN A
VERY MOIST ENVIRONMENT SO HEAVY RAINFALL AND LOCALIZED FLASH
FLOODING IS ALSO A THREAT.
PLAN TO UPDATE GRIDS SHORTLY TO INTRODUCE POPS FOR THIS AFTERNOON
SPREADING THEM FROM WEST TO EAST. GENERALLY LIKE THE TRENDS IN THE
EXPERIMENTAL HRRR WHICH SHOWS STORMS DEVELOPING IN EAST AND
NORTHEAST OF THE IA/MO DECAYING MCS AND OUTFLOW BOUNDARY. WITH
MODEL GUIDANCE ALL OVER THE PLACE AND CAMS NOT HANDLING ONGOING
SITUATION WELL CONFIDENCE IS DIMINISHED...BUT CERTAINLY
OBSERVATIONAL TRENDS SUPPORT THE ABOVE FORECAST SCENARIO AND PLAN
TO INCREASE POPS INTO THE HIGH END CHANCE RANGE FOR NOW.
DESPITE THE HIGHER STORM CHANCES TODAY...PRIOR TO ANY STORMS HEAT
INDICES ARE LIKELY TO REACH 100 TO POTENTIALLY 110 DEGREES TODAY
SO LEAVING THE HEAT HEADLINES UNCHANGED.
GRIDS ARE GOING TO TAKE A LOT OF SURGERY TO REFLECT THE ABOVE
THINKING SINCE THERE IS NO REAL GUIDANCE REFLECTING CURRENT TRENDS
OR ABOVE THINKING...BUT FORECAST UPDATES ARE FORTHCOMING.
IZZI
&&
.LONG TERM...
227 PM CDT
TOMORROW THROUGH TUESDAY...
A COLD FRONT WILL SHIFT ACROSS THE REGION ON SUNDAY. HOWEVER...IT
NOW APPEARS THAT THE BETTER THREAT FOR STRONG TO SEVERE STORMS ON
SUNDAY AFTERNOON MAY REMAIN SOUTH OF MY AREA ALL TOGETHER AS SHOWERS
AND THUNDERSTORMS TONIGHT INTO EARLY SUNDAY LOOK TO SHIFT THE MAIN
FOCUS FARTHER SOUTH THAN ORIGINALLY THOUGHT. WITH THIS IN MIND I
HAVE BACKED OFF ON POPS...ESPECIALLY SUNDAY AFTERNOON...WHEN I HAVE
FOCUSED THE HIGHEST POPS ACROSS MY EXTREME SOUTHERN COUNTIES IN
CENTRAL ILLINOIS.
ANOTHER CHANCE OF THUNDERSTORMS...WITH HEAVY RAINFALL AND POSSIBLY
STRONG WILL RETURN TO THE FORECAST ON MONDAY AS ANOTHER MID LEVEL
DISTURBANCE MOVES ACROSS THE AREA. GUIDANCE HAS NOT HAD THE BEST
HANDLE ON THIS DISTURBANCE THE PAST COUPLE OF RUNS...WITH IT
PREVIOUSLY APPEARING THAT THE MAIN THREAT OF STORMS COULD STAY SOUTH
OF THE AREA. HOWEVER...WITH THE POTENTIAL OF A FARTHER NORTH FOCUS
OF STORMS...I HAVE INCLUDED A CHANCE OF STORMS ON MONDAY...WITH
SLIGHTLY HIGHER POPS ACROSS THE SOUTHERN HALF OF THE AREA.
SURFACE HIGH PRESSURE IS EXPECTED TO BUILD OVER THE AREA ON
TUESDAY...SO IT APPEARS THAT TUESDAY COULD BE A DRY AND COOLER DAY
ACROSS THE AREA.
KJB
TUESDAY NIGHT THROUGH FRIDAY...
NORTHWEST FLOW ALOFT CONTINUES TUESDAY NIGHT THROUGH MID WEEK WITH A
FEW UPPER LEVEL WAVES MOVING THROUGH OVER THE END OF THE WEEK. AT
THE SURFACE HIGH PRESSURE SPREADS EAST OVER THE REGION TUESDAY NIGHT
AND THEN SHIFTS EAST OVER THE APPALACHIANS THURSDAY.
LOOKING AT A SHORT PERIOD OF DRY CONDITIONS THROUGH AT LEAST
WEDNESDAY NIGHT...POSSIBLY THROUGH THE END OF THE WEEK IF THE ECMWF
IS RIGHT. THE GFS FEATURES PRECIP ON THE BACKSIDE OF THE HIGH
THURSDAY NIGHT INTO FRIDAY. CONFIDENCE IS LOW SO KEPT THE CHANCE OF
PRECIP IN THE LOW END CHANCE OR LOWER RANGE.
FOR TEMPS...HAVE A SLOW WARMING TREND WITH TEMPS IN THE LOW TO MID
80S AND TEMPS COULD BE WARMER THAN FORECAST DEPENDING ON THE AMOUNT
OF PRECIP THAT OCCURS. THE GFS IS A BIT WARMER WITH 925MB TEMPS IN
THE MID TO UPPER 20S WHICH WOULD SUGGEST HIGH TEMPS IN THE 90S.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* OUTFLOW HAS MOVED SOUTH OF THE TERMMINALS... NORTH WINDS
EXPECTED TO PERSIST THROUGH 23000-2330Z BEFORE SOUTHWEST WINDS
RESTABLISH.
* TSRA EXITING THE AREA BEWTEEN 22-23Z.
* ANOTHER ROUND OF SHRA AND PERHAPS SOME EMBEDDED TSRA EARLY
SUNDAY MORNING.
ED F
//DISCUSSION...UPDATED 18Z...
A GUST FRONT FROM THE CONVECTION EARLIER THIS MORNING HAS STALLED
FROM BELVIDERE IL THROUGH HIGHLAND INDIANA. WINDS NORTHEAST OF THE
BOUNDARY ARE SLOWLY VEERING FROM NE OR E TO SE...AND EXPECTING
SOUTHWEST WINDS EARLY THIS AFTN. CONDITIONS CONTINUE TO IMPROVE
FOR STORMS. STORMS SHOULD FORM ALONG THE BOUNDARY AND AHEAD OF THE
UPPER LEVEL DISTURBANCE CURRENTLY OVER IOWA THAT IS SHIFTING EAST.
STRONG TO SEVERE STORMS ARE PROBABLE. WHILE CONFIDENCE IS MEDIUM
IN COVERAGE...TIMING...AND EXACT LOCATION...HAVE HIGH CONFIDENCE
THAT THERE SHOULD BE ENOUGH CONVECTION AROUND TO DISRUPT AIR
TRAFFIC. ALL STORMS WILL ALSO PRODUCE TORRENTIAL DOWNPOURS WHICH
WILL LIMIT VISIBILITY.
TSRA PUSHES EAST OF THE TERMINALS THIS EVENING WITH SOUTHWEST
WINDS LESS THAN 15 KT. A COLD FRONT SINKS SOUTHEAST THROUGH THE
REGION SUNDAY MORNING. SHOWERS AND A FEW EMBEDDED THUNDERSTORMS
SHOULD FORM AHEAD OF IT BUT THE NUMBER OF THUNDERSTORMS WILL BE
LIMITED BY HOW STABLE WE ARE BEHIND THIS AFTERNOON/S
THUNDERSTORMS. WINDS SHIFT TO NORTHWEST BEHIND THE COLD FRONT WITH
VFR CONDITIONS.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM TO HIGH CONFIDENCE IN WIND FORECAST.
* MEDIUM TO HIGH CONFIDENCE IN TSRA EXITING TERMINAL AREAS BY
23Z.
* MEDIUM CONFIDENCE IN COVERAGE AND TIMING OF -SHRA AND VCTS EARLY
SUNDAY MORNING.
ED F
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR. WX NIL.
MONDAY...VFR. WX NIL.
TUESDAY...SLIGHT CHANCE TSRA IN THE AFTERNOON.
WEDNESDAY...VFR. WX NIL.
THURSDAY...CHANCE TSRA.
FRIDAY...VFR/WX NIL EARLY. CHANCE TSRA OVERNIGHT.
KREIN
&&
.MARINE...
233 PM CDT
THE MAIN CONCERNS OVER LAKE MICHGAN WILL BE THE THREAT OF SEVERE
THUNDERSTORMS THIS AFTERNOON AND EVENING. CURRENTLY A LARGE AREA
OF THUNDERSTORMS DEVELOPING OVER SOUTHERN WISCONSIN AND NORTHERN
ILLINOIS AND THIS ACTIVITY WILL MOVE OVER SOUTHERN LAKE MICHIGAN
THIS AFTERNOON INTO THE EVENING. EXPECT STRONG WINDS AND LOCALLY
HIGH WAVES IN AND AROUND THE STORMS.
OTHERWISE...THINGS SHOULD QUIET DOWN ON THE LAKE BY SUNDAY
FOLLOWING A COLD FRONTAL PASSAGE.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 UNTIL 8 PM SATURDAY.
FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL MIDNIGHT SUNDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL
MIDNIGHT SUNDAY.
HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 8 PM
SATURDAY.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
337 PM CDT SAT JUL 18 2015
.MESOSCALE DISCUSSION...
324 PM CDT
THUNDERSTORMS RAPIDLY DEVELOPED ACROSS NORTH/NORTHEAST IL THIS
AFTERNOON...AS A CUMULUS FIELD BEGAN TO COLLIDE WITH THE LAKE
BOUNDARY THAT HAD PUSHED WEST. THIS CONVERGENCE ZONE ADDED TO THE
LIFT...COUPLED WITH IMPRESSIVE MLCAPE VALUES...AND PARCELS WERE
ABLE TO ASCEND RAPIDLY THROUGH A VERY MOIST AND UNSTABLE
ENVIRONMENT. JUST SOUTH OF THE CHICAGO METRO AREA DEW POINTS HAVE
POOLED TO AROUND 80 DEG THIS AFTERNOON...WITH SFC WINDS ACROSS
NORTHWEST INDIANA SLIGHTLY BACKED TO THE SOUTH.
ALONG WITH THE RAPID ASCEND OF PARCELS AND DEVELOPING
UPDRAFTS...THE CONVGENCE ZONE HAS ALSO ALLOWED FOR INCREASED LOW
LEVEL HELICITY. THIS REINFORCES THE RISK FOR SOME ROTATING
UPDRAFTS AND ISOLATED TORNADO HAZARD THIS AFTERNOON/EARLY EVENING.
THE MAIN LOCATIONS FOR THE NEXT COUPLE OF HOURS CONTINUES TO BE
THE FAR NORTHEAST IL/NORTHWEST IN AREAS...INCLUDING THE CHICAGO
METRO AREA SPILLING INTO LAKE MICHIGAN.
AS FOR CONTINUED DEVELOPMENT...HI-RES GUIDANCE DIFFERS ON HOW THE
NEXT FEW HOURS WILL UNFOLD. THE LATEST HRRR SOLUTIONS SUGGEST THE
CLUSTER ACROSS FAR NORTHEAST IL WILL SLIDE SOUTHEAST ALONG THE
CONVERGENCE ZONE AND MAINTAIN STRENGTH INTO NORTHWEST IN...WITH
LITTLE ADDITIONAL DEVELOPMENT. HOWEVER...AS ELUDED TO EARLIER
ABOUT DIFFERING SOLUTIONS RAP AND LOCAL ARW8KM SUGGEST SOME NEW
DEVELOPMENT FURTHER WEST. INVESTIGATING THE VISIBLE IMAGERY AND
THE CUMULUS FIELD WEST OF THE CURRENT CONVECTION LOOKS TO BE LESS
VERTICAL...AND POSSIBLY EVEN THINNING SLIGHTLY. DEW POINTS IN A
FEW UPSTREAM AREAS HAVE ALSO MIXED DOWN TO THE LOW 70S/UPR 60S
WITH WINDS VEERING TO THE WEST AND BECOMING MORE UNIFORM.
BEACHLER
&&
.SHORT TERM...
227 PM CDT
A FLASH FLOOD WATCH WAS ISSUED FOR THE ENTIRE WARNING AREA DUE TO
CONCERNS ABOUT TORRENTIAL RAINFALL RATES.
OUTFLOW BOUNDARY FROM EARLIER WISCONSIN MCS HAS SAGGED SOUTH INTO
NORTHERN CWA AND IS BEGINNING TO STALL OUT OVER NORTH CENTRAL
ILLINOIS. OVER NORTHEAST ILLINOIS THE LAKE HAS AUGMENTED THE
BOUNDARY AND PROVIDED SOME ADDITIONAL SOUTHWARD ACCELERATION
ADJACENT TO LAKE MICHIGAN. ANTICIPATE THE BOUNDARY WILL STALL OUT
EVEN OVER NORTHEAST ILLINOIS AND PROBABLY RETREAT NORTH DURING THE
DAY AS SUNSHINE ALLOWS FOR STRONG HEATING/MIXING AND A MODEST
SOUTHWEST WIND DEVELOPS. DESPITE THE INITIALLY COOLER AIR NEAR THE
LAKE...STILL FEEL THERE IS A REASONABLY GOOD CHANCE THAT THE
BOUNDARY WILL STALL/RETREAT ENOUGH TO PROVIDE FOR A HOT/HUMID
AFTERNOON WITH HEAT INDICES ABOVE 100 OVER EVEN NORTHEAST ILLINOIS
SO NOT PLANNING TO CHANGE HEAT ADVISORY ANY THIS MORNING. MAY
BROADEN THE RANGE OF HEAT INDICES TO 100 TO 110 AS CLOUDS FROM
IA/MO MCS MAY LIMIT THE HEAT SOME THIS AFTERNOON...MAINLY WESTERN
CWA.
AMPLE SUNSHINE IN ADVANCE OF ANY CLOUDINESS FROM MO/IA CONVECTION
WILL ALLOW FOR RAPID HEATING AND DESTABILIZATION ACROSS THE CWA
THROUGH EARLY AFTERNOON...BUT PARTICULARLY TO THE SOUTH OF THE WI
MCS REMNANT OUTFLOW BOUNDARY. DVN/ILX MORNING SOUNDINGS BOTH SHOW
MODERATELY STEEP LOW/MID LEVEL LAPSE RATES AND AS TEMPS/DEWPOINTS
RISE TOWARD PROJECTED HIGHS REGION SHOULD BE LEFT UNCAPPED BY
EARLY AFTERNOON...WITH MODIFIED ILX SOUNDING SUPPORTING SHOWING
MLCAPE VALUES NEARING 4000 J/KG BY EARLY THIS AFTERNOON WITH SFC
PARCEL OF 90/77...WHICH APPEARS EASILY ATTAINABLE IN THE WARM
SECTOR TODAY.
MORNING UPPER AIR ANALYSIS AND ACARS DATA SHOW 35-45KT FLOW
AROUND 6KM FROM IA INTO NORTHERN ILLINOIS WHICH WILL RESULT IN
0-6KM SHEAR VALUES OF AT LEAST AROUND 30KT...WHICH COMBINED WITH
SUCH STRONG INSTABILITY WOULD SUPPORT ORGANIZED CONVECTION AND
PERHAPS EVEN A SUPERCELL THREAT...ESPECIALLY IF ANY CELLS WERE TO
RIDE OUTFLOW BOUNDARY. PRIMARY SEVERE THREAT WOULD BE LARGE HAIL
AND DAMAGING WINDS...THOUGH CANNOT COMPLETELY RULE OUT A TORNADO
THREAT WITH ANY CELLS INTERACTING WITH BOUNDARIES GIVEN THE STRONG
LOW LEVEL CAPE AND LOW LCL HEIGHTS. OBVIOUSLY STILL SITTING IN A
VERY MOIST ENVIRONMENT SO HEAVY RAINFALL AND LOCALIZED FLASH
FLOODING IS ALSO A THREAT.
PLAN TO UPDATE GRIDS SHORTLY TO INTRODUCE POPS FOR THIS AFTERNOON
SPREADING THEM FROM WEST TO EAST. GENERALLY LIKE THE TRENDS IN THE
EXPERIMENTAL HRRR WHICH SHOWS STORMS DEVELOPING IN EAST AND
NORTHEAST OF THE IA/MO DECAYING MCS AND OUTFLOW BOUNDARY. WITH
MODEL GUIDANCE ALL OVER THE PLACE AND CAMS NOT HANDLING ONGOING
SITUATION WELL CONFIDENCE IS DIMINISHED...BUT CERTAINLY
OBSERVATIONAL TRENDS SUPPORT THE ABOVE FORECAST SCENARIO AND PLAN
TO INCREASE POPS INTO THE HIGH END CHANCE RANGE FOR NOW.
DESPITE THE HIGHER STORM CHANCES TODAY...PRIOR TO ANY STORMS HEAT
INDICES ARE LIKELY TO REACH 100 TO POTENTIALLY 110 DEGREES TODAY
SO LEAVING THE HEAT HEADLINES UNCHANGED.
GRIDS ARE GOING TO TAKE A LOT OF SURGERY TO REFLECT THE ABOVE
THINKING SINCE THERE IS NO REAL GUIDANCE REFLECTING CURRENT TRENDS
OR ABOVE THINKING...BUT FORECAST UPDATES ARE FORTHCOMING.
IZZI
&&
.LONG TERM...
227 PM CDT
TOMORROW THROUGH TUESDAY...
A COLD FRONT WILL SHIFT ACROSS THE REGION ON SUNDAY. HOWEVER...IT
NOW APPEARS THAT THE BETTER THREAT FOR STRONG TO SEVERE STORMS ON
SUNDAY AFTERNOON MAY REMAIN SOUTH OF MY AREA ALL TOGETHER AS SHOWERS
AND THUNDERSTORMS TONIGHT INTO EARLY SUNDAY LOOK TO SHIFT THE MAIN
FOCUS FARTHER SOUTH THAN ORIGINALLY THOUGHT. WITH THIS IN MIND I
HAVE BACKED OFF ON POPS...ESPECIALLY SUNDAY AFTERNOON...WHEN I HAVE
FOCUSED THE HIGHEST POPS ACROSS MY EXTREME SOUTHERN COUNTIES IN
CENTRAL ILLINOIS.
ANOTHER CHANCE OF THUNDERSTORMS...WITH HEAVY RAINFALL AND POSSIBLY
STRONG WILL RETURN TO THE FORECAST ON MONDAY AS ANOTHER MID LEVEL
DISTURBANCE MOVES ACROSS THE AREA. GUIDANCE HAS NOT HAD THE BEST
HANDLE ON THIS DISTURBANCE THE PAST COUPLE OF RUNS...WITH IT
PREVIOUSLY APPEARING THAT THE MAIN THREAT OF STORMS COULD STAY SOUTH
OF THE AREA. HOWEVER...WITH THE POTENTIAL OF A FARTHER NORTH FOCUS
OF STORMS...I HAVE INCLUDED A CHANCE OF STORMS ON MONDAY...WITH
SLIGHTLY HIGHER POPS ACROSS THE SOUTHERN HALF OF THE AREA.
SURFACE HIGH PRESSURE IS EXPECTED TO BUILD OVER THE AREA ON
TUESDAY...SO IT APPEARS THAT TUESDAY COULD BE A DRY AND COOLER DAY
ACROSS THE AREA.
KJB
TUESDAY NIGHT THROUGH FRIDAY...
NORTHWEST FLOW ALOFT CONTINUES TUESDAY NIGHT THROUGH MID WEEK WITH A
FEW UPPER LEVEL WAVES MOVING THROUGH OVER THE END OF THE WEEK. AT
THE SURFACE HIGH PRESSURE SPREADS EAST OVER THE REGION TUESDAY NIGHT
AND THEN SHIFTS EAST OVER THE APPALACHIANS THURSDAY.
LOOKING AT A SHORT PERIOD OF DRY CONDITIONS THROUGH AT LEAST
WEDNESDAY NIGHT...POSSIBLY THROUGH THE END OF THE WEEK IF THE ECMWF
IS RIGHT. THE GFS FEATURES PRECIP ON THE BACKSIDE OF THE HIGH
THURSDAY NIGHT INTO FRIDAY. CONFIDENCE IS LOW SO KEPT THE CHANCE OF
PRECIP IN THE LOW END CHANCE OR LOWER RANGE.
FOR TEMPS...HAVE A SLOW WARMING TREND WITH TEMPS IN THE LOW TO MID
80S AND TEMPS COULD BE WARMER THAN FORECAST DEPENDING ON THE AMOUNT
OF PRECIP THAT OCCURS. THE GFS IS A BIT WARMER WITH 925MB TEMPS IN
THE MID TO UPPER 20S WHICH WOULD SUGGEST HIGH TEMPS IN THE 90S.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SOUTH WINDS CONTINUE TO VEER TO SOUTHWEST THIS AFTN AND GUST TO
ARND 20 KT BEHIND THE THUNDERSTORMS. GUSTS DIMINISH THIS
EVENING.
* PERIODS OF TSRA WITH HEAVY RAIN EXPECTED THIS AFTN. STRONG TO
SEVERE STORMS PROBABLE.
* ANOTHER ROUND OF SHRA AND PERHAPS SOME EMBEDDED TSRA EARLY
SUNDAY MORNING.
JEE
//DISCUSSION...UPDATED 18Z...
A GUST FRONT FROM THE CONVECTION EARLIER THIS MORNING HAS STALLED
FROM BELVIDERE IL THROUGH HIGHLAND INDIANA. WINDS NORTHEAST OF THE
BOUNDARY ARE SLOWLY VEERING FROM NE OR E TO SE...AND EXPECTING
SOUTHWEST WINDS EARLY THIS AFTN. CONDITIONS CONTINUE TO IMPROVE
FOR STORMS. STORMS SHOULD FORM ALONG THE BOUNDARY AND AHEAD OF THE
UPPER LEVEL DISTURBANCE CURRENTLY OVER IOWA THAT IS SHIFTING EAST.
STRONG TO SEVERE STORMS ARE PROBABLE. WHILE CONFIDENCE IS MEDIUM
IN COVERAGE...TIMING...AND EXACT LOCATION...HAVE HIGH CONFIDENCE
THAT THERE SHOULD BE ENOUGH CONVECTION AROUND TO DISRUPT AIR
TRAFFIC. ALL STORMS WILL ALSO PRODUCE TORRENTIAL DOWNPOURS WHICH
WILL LIMIT VISIBILITY.
TSRA PUSHES EAST OF THE TERMINALS THIS EVENING WITH SOUTHWEST
WINDS LESS THAN 15 KT. A COLD FRONT SINKS SOUTHEAST THROUGH THE
REGION SUNDAY MORNING. SHOWERS AND A FEW EMBEDDED THUNDERSTORMS
SHOULD FORM AHEAD OF IT BUT THE NUMBER OF THUNDERSTORMS WILL BE
LIMITED BY HOW STABLE WE ARE BEHIND THIS AFTERNOON/S
THUNDERSTORMS. WINDS SHIFT TO NORTHWEST BEHIND THE COLD FRONT WITH
VFR CONDITIONS.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN WIND FORECAST.
* HIGH CONFIDENCE IN TS THIS AFTN INTO THIS EVENING.
* MEDIUM CONFIDENCE IN COVERAGE AND TIMING OF -SHRA AND VCTS EARLY
SUNDAY MORNING.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR. WX NIL.
MONDAY...VFR. WX NIL.
TUESDAY...SLIGHT CHANCE TSRA IN THE AFTERNOON.
WEDNESDAY...VFR. WX NIL.
THURSDAY...CHANCE TSRA.
FRIDAY...VFR/WX NIL EARLY. CHANCE TSRA OVERNIGHT.
KREIN
&&
.MARINE...
233 PM CDT
THE MAIN CONCERNS OVER LAKE MICHGAN WILL BE THE THREAT OF SEVERE
THUNDERSTORMS THIS AFTERNOON AND EVENING. CURRENTLY A LARGE AREA
OF THUNDERSTORMS DEVELOPING OVER SOUTHERN WISCONSIN AND NORTHERN
ILLINOIS AND THIS ACTIVITY WILL MOVE OVER SOUTHERN LAKE MICHIGAN
THIS AFTERNOON INTO THE EVENING. EXPECT STRONG WINDS AND LOCALLY
HIGH WAVES IN AND AROUND THE STORMS.
OTHERWISE...THINGS SHOULD QUIET DOWN ON THE LAKE BY SUNDAY
FOLLOWING A COLD FRONTAL PASSAGE.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 UNTIL 8 PM SATURDAY.
FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL MIDNIGHT SUNDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL
MIDNIGHT SUNDAY.
HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 8 PM
SATURDAY.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
239 PM CDT SAT JUL 18 2015
.SHORT TERM...
957 AM CDT
A FLASH FLOOD WATCH WAS ISSUED FOR THE ENTIRE WARNING AREA DUE TO
CONCERNS ABOUT TORRENTIAL RAINFALL RATES.
OUTFLOW BOUNDARY FROM EARLIER WISCONSIN MCS HAS SAGGED SOUTH INTO
NORTHERN CWA AND IS BEGINNING TO STALL OUT OVER NORTH CENTRAL
ILLINOIS. OVER NORTHEAST ILLINOIS THE LAKE HAS AUGMENTED THE
BOUNDARY AND PROVIDED SOME ADDITIONAL SOUTHWARD ACCELERATION
ADJACENT TO LAKE MICHIGAN. ANTICIPATE THE BOUNDARY WILL STALL OUT
EVEN OVER NORTHEAST ILLINOIS AND PROBABLY RETREAT NORTH DURING THE
DAY AS SUNSHINE ALLOWS FOR STRONG HEATING/MIXING AND A MODEST
SOUTHWEST WIND DEVELOPS. DESPITE THE INITIALLY COOLER AIR NEAR THE
LAKE...STILL FEEL THERE IS A REASONABLY GOOD CHANCE THAT THE
BOUNDARY WILL STALL/RETREAT ENOUGH TO PROVIDE FOR A HOT/HUMID
AFTERNOON WITH HEAT INDICES ABOVE 100 OVER EVEN NORTHEAST ILLINOIS
SO NOT PLANNING TO CHANGE HEAT ADVISORY ANY THIS MORNING. MAY
BROADEN THE RANGE OF HEAT INDICES TO 100 TO 110 AS CLOUDS FROM
IA/MO MCS MAY LIMIT THE HEAT SOME THIS AFTERNOON...MAINLY WESTERN
CWA.
AMPLE SUNSHINE IN ADVANCE OF ANY CLOUDINESS FROM MO/IA CONVECTION
WILL ALLOW FOR RAPID HEATING AND DESTABILIZATION ACROSS THE CWA
THROUGH EARLY AFTERNOON...BUT PARTICULARLY TO THE SOUTH OF THE WI
MCS REMNANT OUTFLOW BOUNDARY. DVN/ILX MORNING SOUNDINGS BOTH SHOW
MODERATELY STEEP LOW/MID LEVEL LAPSE RATES AND AS TEMPS/DEWPOINTS
RISE TOWARD PROJECTED HIGHS REGION SHOULD BE LEFT UNCAPPED BY
EARLY AFTERNOON...WITH MODIFIED ILX SOUNDING SUPPORTING SHOWING
MLCAPE VALUES NEARING 4000 J/KG BY EARLY THIS AFTERNOON WITH SFC
PARCEL OF 90/77...WHICH APPEARS EASILY ATTAINABLE IN THE WARM
SECTOR TODAY.
MORNING UPPER AIR ANALYSIS AND ACARS DATA SHOW 35-45KT FLOW
AROUND 6KM FROM IA INTO NORTHERN ILLINOIS WHICH WILL RESULT IN
0-6KM SHEAR VALUES OF AT LEAST AROUND 30KT...WHICH COMBINED WITH
SUCH STRONG INSTABILITY WOULD SUPPORT ORGANIZED CONVECTION AND
PERHAPS EVEN A SUPERCELL THREAT...ESPECIALLY IF ANY CELLS WERE TO
RIDE OUTFLOW BOUNDARY. PRIMARY SEVERE THREAT WOULD BE LARGE HAIL
AND DAMAGING WINDS...THOUGH CANNOT COMPLETELY RULE OUT A TORNADO
THREAT WITH ANY CELLS INTERACTING WITH BOUNDARIES GIVEN THE STRONG
LOW LEVEL CAPE AND LOW LCL HEIGHTS. OBVIOUSLY STILL SITTING IN A
VERY MOIST ENVIRONMENT SO HEAVY RAINFALL AND LOCALIZED FLASH
FLOODING IS ALSO A THREAT.
PLAN TO UPDATE GRIDS SHORTLY TO INTRODUCE POPS FOR THIS AFTERNOON
SPREADING THEM FROM WEST TO EAST. GENERALLY LIKE THE TRENDS IN THE
EXPERIMENTAL HRRR WHICH SHOWS STORMS DEVELOPING IN EAST AND
NORTHEAST OF THE IA/MO DECAYING MCS AND OUTFLOW BOUNDARY. WITH
MODEL GUIDANCE ALL OVER THE PLACE AND CAMS NOT HANDLING ONGOING
SITUATION WELL CONFIDENCE IS DIMINISHED...BUT CERTAINLY
OBSERVATIONAL TRENDS SUPPORT THE ABOVE FORECAST SCENARIO AND PLAN
TO INCREASE POPS INTO THE HIGH END CHANCE RANGE FOR NOW.
DESPITE THE HIGHER STORM CHANCES TODAY...PRIOR TO ANY STORMS HEAT
INDICES ARE LIKELY TO REACH 100 TO POTENTIALLY 110 DEGREES TODAY
SO LEAVING THE HEAT HEADLINES UNCHANGED.
GRIDS ARE GOING TO TAKE A LOT OF SURGERY TO REFLECT THE ABOVE
THINKING SINCE THERE IS NO REAL GUIDANCE REFLECTING CURRENT TRENDS
OR ABOVE THINKING...BUT FORECAST UPDATES ARE FORTHCOMING.
IZZI
&&
.LONG TERM...
227 PM CDT
TOMORROW THROUGH TUESDAY...
A COLD FRONT WILL SHIFT ACROSS THE REGION ON SUNDAY. HOWEVER...IT
NOW APPEARS THAT THE BETTER THREAT FOR STRONG TO SEVERE STORMS ON
SUNDAY AFTERNOON MAY REMAIN SOUTH OF MY AREA ALL TOGETHER AS SHOWERS
AND THUNDERSTORMS TONIGHT INTO EARLY SUNDAY LOOK TO SHIFT THE MAIN
FOCUS FARTHER SOUTH THAN ORIGINALLY THOUGHT. WITH THIS IN MIND I
HAVE BACKED OFF ON POPS...ESPECIALLY SUNDAY AFTERNOON...WHEN I HAVE
FOCUSED THE HIGHEST POPS ACROSS MY EXTREME SOUTHERN COUNTIES IN
CENTRAL ILLINOIS.
ANOTHER CHANCE OF THUNDERSTORMS...WITH HEAVY RAINFALL AND POSSIBLY
STRONG WILL RETURN TO THE FORECAST ON MONDAY AS ANOTHER MID LEVEL
DISTURBANCE MOVES ACROSS THE AREA. GUIDANCE HAS NOT HAD THE BEST
HANDLE ON THIS DISTURBANCE THE PAST COUPLE OF RUNS...WITH IT
PREVIOUSLY APPEARING THAT THE MAIN THREAT OF STORMS COULD STAY SOUTH
OF THE AREA. HOWEVER...WITH THE POTENTIAL OF A FARTHER NORTH FOCUS
OF STORMS...I HAVE INCLUDED A CHANCE OF STORMS ON MONDAY...WITH
SLIGHTLY HIGHER POPS ACROSS THE SOUTHERN HALF OF THE AREA.
SURFACE HIGH PRESSURE IS EXPECTED TO BUILD OVER THE AREA ON
TUESDAY...SO IT APPEARS THAT TUESDAY COULD BE A DRY AND COOLER DAY
ACROSS THE AREA.
KJB
TUESDAY NIGHT THROUGH FRIDAY...
NORTHWEST FLOW ALOFT CONTINUES TUESDAY NIGHT THROUGH MID WEEK WITH A
FEW UPPER LEVEL WAVES MOVING THROUGH OVER THE END OF THE WEEK. AT
THE SURFACE HIGH PRESSURE SPREADS EAST OVER THE REGION TUESDAY NIGHT
AND THEN SHIFTS EAST OVER THE APPALACHIANS THURSDAY.
LOOKING AT A SHORT PERIOD OF DRY CONDITIONS THROUGH AT LEAST
WEDNESDAY NIGHT...POSSIBLY THROUGH THE END OF THE WEEK IF THE ECMWF
IS RIGHT. THE GFS FEATURES PRECIP ON THE BACKSIDE OF THE HIGH
THURSDAY NIGHT INTO FRIDAY. CONFIDENCE IS LOW SO KEPT THE CHANCE OF
PRECIP IN THE LOW END CHANCE OR LOWER RANGE.
FOR TEMPS...HAVE A SLOW WARMING TREND WITH TEMPS IN THE LOW TO MID
80S AND TEMPS COULD BE WARMER THAN FORECAST DEPENDING ON THE AMOUNT
OF PRECIP THAT OCCURS. THE GFS IS A BIT WARMER WITH 925MB TEMPS IN
THE MID TO UPPER 20S WHICH WOULD SUGGEST HIGH TEMPS IN THE 90S.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SOUTH WINDS CONTINUE TO VEER TO SOUTHWEST THIS AFTN AND GUST TO
ARND 20 KT BEHIND THE THUNDERSTORMS. GUSTS DIMINISH THIS
EVENING.
* PERIODS OF TSRA WITH HEAVY RAIN EXPECTED THIS AFTN. STRONG TO
SEVERE STORMS PROBABLE.
* ANOTHER ROUND OF SHRA AND PERHAPS SOME EMBEDDED TSRA EARLY
SUNDAY MORNING.
JEE
//DISCUSSION...UPDATED 18Z...
A GUST FRONT FROM THE CONVECTION EARLIER THIS MORNING HAS STALLED
FROM BELVIDERE IL THROUGH HIGHLAND INDIANA. WINDS NORTHEAST OF THE
BOUNDARY ARE SLOWLY VEERING FROM NE OR E TO SE...AND EXPECTING
SOUTHWEST WINDS EARLY THIS AFTN. CONDITIONS CONTINUE TO IMPROVE
FOR STORMS. STORMS SHOULD FORM ALONG THE BOUNDARY AND AHEAD OF THE
UPPER LEVEL DISTURBANCE CURRENTLY OVER IOWA THAT IS SHIFTING EAST.
STRONG TO SEVERE STORMS ARE PROBABLE. WHILE CONFIDENCE IS MEDIUM
IN COVERAGE...TIMING...AND EXACT LOCATION...HAVE HIGH CONFIDENCE
THAT THERE SHOULD BE ENOUGH CONVECTION AROUND TO DISRUPT AIR
TRAFFIC. ALL STORMS WILL ALSO PRODUCE TORRENTIAL DOWNPOURS WHICH
WILL LIMIT VISIBILITY.
TSRA PUSHES EAST OF THE TERMINALS THIS EVENING WITH SOUTHWEST
WINDS LESS THAN 15 KT. A COLD FRONT SINKS SOUTHEAST THROUGH THE
REGION SUNDAY MORNING. SHOWERS AND A FEW EMBEDDED THUNDERSTORMS
SHOULD FORM AHEAD OF IT BUT THE NUMBER OF THUNDERSTORMS WILL BE
LIMITED BY HOW STABLE WE ARE BEHIND THIS AFTERNOON/S
THUNDERSTORMS. WINDS SHIFT TO NORTHWEST BEHIND THE COLD FRONT WITH
VFR CONDITIONS.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN WIND FORECAST.
* HIGH CONFIDENCE IN TS THIS AFTN INTO THIS EVENING.
* MEDIUM CONFIDENCE IN COVERAGE AND TIMING OF -SHRA AND VCTS EARLY
SUNDAY MORNING.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR. WX NIL.
MONDAY...VFR. WX NIL.
TUESDAY...SLIGHT CHANCE TSRA IN THE AFTERNOON.
WEDNESDAY...VFR. WX NIL.
THURSDAY...CHANCE TSRA.
FRIDAY...VFR/WX NIL EARLY. CHANCE TSRA OVERNIGHT.
KREIN
&&
.MARINE...
233 PM CDT
THE MAIN CONCERNS OVER LAKE MICHGAN WILL BE THE THREAT OF SEVERE
THUNDERSTORMS THIS AFTERNOON AND EVENING. CURRENTLY A LARGE AREA
OF THUNDERSTORMS DEVELOPING OVER SOUTHERN WISCONSIN AND NORTHERN
ILLINOIS AND THIS ACTIVITY WILL MOVE OVER SOUTHERN LAKE MICHIGAN
THIS AFTERNOON INTO THE EVENING. EXPECT STRONG WINDS AND LOCALLY
HIGH WAVES IN AND AROUND THE STORMS.
OTHERWISE...THINGS SHOULD QUIET DOWN ON THE LAKE BY SUNDAY
FOLLOWING A COLD FRONTAL PASSAGE.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 UNTIL 8 PM SATURDAY.
FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL MIDNIGHT SUNDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL
MIDNIGHT SUNDAY.
HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 8 PM
SATURDAY.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
236 PM CDT SAT JUL 18 2015
.SHORT TERM...
957 AM CDT
A FLASH FLOOD WATCH WAS ISSUED FOR THE ENTIRE WARNING AREA DUE TO
CONCERNS ABOUT TORRENTIAL RAINFALL RATES.
OUTFLOW BOUNDARY FROM EARLIER WISCONSIN MCS HAS SAGGED SOUTH INTO
NORTHERN CWA AND IS BEGINNING TO STALL OUT OVER NORTH CENTRAL
ILLINOIS. OVER NORTHEAST ILLINOIS THE LAKE HAS AUGMENTED THE
BOUNDARY AND PROVIDED SOME ADDITIONAL SOUTHWARD ACCELERATION
ADJACENT TO LAKE MICHIGAN. ANTICIPATE THE BOUNDARY WILL STALL OUT
EVEN OVER NORTHEAST ILLINOIS AND PROBABLY RETREAT NORTH DURING THE
DAY AS SUNSHINE ALLOWS FOR STRONG HEATING/MIXING AND A MODEST
SOUTHWEST WIND DEVELOPS. DESPITE THE INITIALLY COOLER AIR NEAR THE
LAKE...STILL FEEL THERE IS A REASONABLY GOOD CHANCE THAT THE
BOUNDARY WILL STALL/RETREAT ENOUGH TO PROVIDE FOR A HOT/HUMID
AFTERNOON WITH HEAT INDICES ABOVE 100 OVER EVEN NORTHEAST ILLINOIS
SO NOT PLANNING TO CHANGE HEAT ADVISORY ANY THIS MORNING. MAY
BROADEN THE RANGE OF HEAT INDICES TO 100 TO 110 AS CLOUDS FROM
IA/MO MCS MAY LIMIT THE HEAT SOME THIS AFTERNOON...MAINLY WESTERN
CWA.
AMPLE SUNSHINE IN ADVANCE OF ANY CLOUDINESS FROM MO/IA CONVECTION
WILL ALLOW FOR RAPID HEATING AND DESTABILIZATION ACROSS THE CWA
THROUGH EARLY AFTERNOON...BUT PARTICULARLY TO THE SOUTH OF THE WI
MCS REMNANT OUTFLOW BOUNDARY. DVN/ILX MORNING SOUNDINGS BOTH SHOW
MODERATELY STEEP LOW/MID LEVEL LAPSE RATES AND AS TEMPS/DEWPOINTS
RISE TOWARD PROJECTED HIGHS REGION SHOULD BE LEFT UNCAPPED BY
EARLY AFTERNOON...WITH MODIFIED ILX SOUNDING SUPPORTING SHOWING
MLCAPE VALUES NEARING 4000 J/KG BY EARLY THIS AFTERNOON WITH SFC
PARCEL OF 90/77...WHICH APPEARS EASILY ATTAINABLE IN THE WARM
SECTOR TODAY.
MORNING UPPER AIR ANALYSIS AND ACARS DATA SHOW 35-45KT FLOW
AROUND 6KM FROM IA INTO NORTHERN ILLINOIS WHICH WILL RESULT IN
0-6KM SHEAR VALUES OF AT LEAST AROUND 30KT...WHICH COMBINED WITH
SUCH STRONG INSTABILITY WOULD SUPPORT ORGANIZED CONVECTION AND
PERHAPS EVEN A SUPERCELL THREAT...ESPECIALLY IF ANY CELLS WERE TO
RIDE OUTFLOW BOUNDARY. PRIMARY SEVERE THREAT WOULD BE LARGE HAIL
AND DAMAGING WINDS...THOUGH CANNOT COMPLETELY RULE OUT A TORNADO
THREAT WITH ANY CELLS INTERACTING WITH BOUNDARIES GIVEN THE STRONG
LOW LEVEL CAPE AND LOW LCL HEIGHTS. OBVIOUSLY STILL SITTING IN A
VERY MOIST ENVIRONMENT SO HEAVY RAINFALL AND LOCALIZED FLASH
FLOODING IS ALSO A THREAT.
PLAN TO UPDATE GRIDS SHORTLY TO INTRODUCE POPS FOR THIS AFTERNOON
SPREADING THEM FROM WEST TO EAST. GENERALLY LIKE THE TRENDS IN THE
EXPERIMENTAL HRRR WHICH SHOWS STORMS DEVELOPING IN EAST AND
NORTHEAST OF THE IA/MO DECAYING MCS AND OUTFLOW BOUNDARY. WITH
MODEL GUIDANCE ALL OVER THE PLACE AND CAMS NOT HANDLING ONGOING
SITUATION WELL CONFIDENCE IS DIMINISHED...BUT CERTAINLY
OBSERVATIONAL TRENDS SUPPORT THE ABOVE FORECAST SCENARIO AND PLAN
TO INCREASE POPS INTO THE HIGH END CHANCE RANGE FOR NOW.
DESPITE THE HIGHER STORM CHANCES TODAY...PRIOR TO ANY STORMS HEAT
INDICES ARE LIKELY TO REACH 100 TO POTENTIALLY 110 DEGREES TODAY
SO LEAVING THE HEAT HEADLINES UNCHANGED.
GRIDS ARE GOING TO TAKE A LOT OF SURGERY TO REFLECT THE ABOVE
THINKING SINCE THERE IS NO REAL GUIDANCE REFLECTING CURRENT TRENDS
OR ABOVE THINKING...BUT FORECAST UPDATES ARE FORTHCOMING.
IZZI
&&
.LONG TERM...
227 PM CDT
TOMORROW THROUGH TUESDAY...
A COLD FRONT WILL SHIFT ACROSS THE REGION ON SUNDAY. HOWEVER...IT
NOW APPEARS THAT THE BETTER THREAT FOR STRONG TO SEVERE STORMS ON
SUNDAY AFTERNOON MAY REMAIN SOUTH OF MY AREA ALL TOGETHER AS SHOWERS
AND THUNDERSTORMS TONIGHT INTO EARLY SUNDAY LOOK TO SHIFT THE MAIN
FOCUS FARTHER SOUTH THAN ORIGINALLY THOUGHT. WITH THIS IN MIND I
HAVE BACKED OFF ON POPS...ESPECIALLY SUNDAY AFTERNOON...WHEN I HAVE
FOCUSED THE HIGHEST POPS ACROSS MY EXTREME SOUTHERN COUNTIES IN
CENTRAL ILLINOIS.
ANOTHER CHANCE OF THUNDERSTORMS...WITH HEAVY RAINFALL AND POSSIBLY
STRONG WILL RETURN TO THE FORECAST ON MONDAY AS ANOTHER MID LEVEL
DISTURBANCE MOVES ACROSS THE AREA. GUIDANCE HAS NOT HAD THE BEST
HANDLE ON THIS DISTURBANCE THE PAST COUPLE OF RUNS...WITH IT
PREVIOUSLY APPEARING THAT THE MAIN THREAT OF STORMS COULD STAY SOUTH
OF THE AREA. HOWEVER...WITH THE POTENTIAL OF A FARTHER NORTH FOCUS
OF STORMS...I HAVE INCLUDED A CHANCE OF STORMS ON MONDAY...WITH
SLIGHTLY HIGHER POPS ACROSS THE SOUTHERN HALF OF THE AREA.
SURFACE HIGH PRESSURE IS EXPECTED TO BUILD OVER THE AREA ON
TUESDAY...SO IT APPEARS THAT TUESDAY COULD BE A DRY AND COOLER DAY
ACROSS THE AREA.
KJB
TUESDAY NIGHT THROUGH FRIDAY...
NORTHWEST FLOW ALOFT CONTINUES TUESDAY NIGHT THROUGH MID WEEK WITH A
FEW UPPER LEVEL WAVES MOVING THROUGH OVER THE END OF THE WEEK. AT
THE SURFACE HIGH PRESSURE SPREADS EAST OVER THE REGION TUESDAY NIGHT
AND THEN SHIFTS EAST OVER THE APPALACHIANS THURSDAY.
LOOKING AT A SHORT PERIOD OF DRY CONDITIONS THROUGH AT LEAST
WEDNESDAY NIGHT...POSSIBLY THROUGH THE END OF THE WEEK IF THE ECMWF
IS RIGHT. THE GFS FEATURES PRECIP ON THE BACKSIDE OF THE HIGH
THURSDAY NIGHT INTO FRIDAY. CONFIDENCE IS LOW SO KEPT THE CHANCE OF
PRECIP IN THE LOW END CHANCE OR LOWER RANGE.
FOR TEMPS...HAVE A SLOW WARMING TREND WITH TEMPS IN THE LOW TO MID
80S AND TEMPS COULD BE WARMER THAN FORECAST DEPENDING ON THE AMOUNT
OF PRECIP THAT OCCURS. THE GFS IS A BIT WARMER WITH 925MB TEMPS IN
THE MID TO UPPER 20S WHICH WOULD SUGGEST HIGH TEMPS IN THE 90S.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SOUTHEAST WINDS CONTINUE TO VEER TO SOUTHWEST THIS AFTN. GUSTS
DIMINISH THIS EVENING.
* PERIODS OF TSRA WITH HEAVY RAIN EXPECTED THIS AFTN. STRONG TO
SEVERE STORMS PROBABLE.
* ANOTHER ROUND OF SHRA AND PERHAPS SOME EMBEDDED TSRA EARLY
SUNDAY MORNING.
JEE
//DISCUSSION...UPDATED 18Z...
A GUST FRONT FROM THE CONVECTION EARLIER THIS MORNING HAS STALLED
FROM BELVIDERE IL THROUGH HIGHLAND INDIANA. WINDS NORTHEAST OF THE
BOUNDARY ARE SLOWLY VEERING FROM NE OR E TO SE...AND EXPECTING
SOUTHWEST WINDS EARLY THIS AFTN. CONDITIONS CONTINUE TO IMPROVE
FOR STORMS. STORMS SHOULD FORM ALONG THE BOUNDARY AND AHEAD OF THE
UPPER LEVEL DISTURBANCE CURRENTLY OVER IOWA THAT IS SHIFTING EAST.
STRONG TO SEVERE STORMS ARE PROBABLE. WHILE CONFIDENCE IS MEDIUM
IN COVERAGE...TIMING...AND EXACT LOCATION...HAVE HIGH CONFIDENCE
THAT THERE SHOULD BE ENOUGH CONVECTION AROUND TO DISRUPT AIR
TRAFFIC. ALL STORMS WILL ALSO PRODUCE TORRENTIAL DOWNPOURS WHICH
WILL LIMIT VISIBILITY.
TSRA PUSHES EAST OF THE TERMINALS THIS EVENING WITH SOUTHWEST
WINDS LESS THAN 15 KT. A COLD FRONT SINKS SOUTHEAST THROUGH THE
REGION SUNDAY MORNING. SHOWERS AND A FEW EMBEDDED THUNDERSTORMS
SHOULD FORM AHEAD OF IT BUT THE NUMBER OF THUNDERSTORMS WILL BE
LIMITED BY HOW STABLE WE ARE BEHIND THIS AFTERNOON/S
THUNDERSTORMS. WINDS SHIFT TO NORTHWEST BEHIND THE COLD FRONT WITH
VFR CONDITIONS.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN WIND FORECAST.
* MEDIUM-HIGH CONFIDENCE IN TS OCCURRING AND THE POSSIBILITY OF
STRONG TO SEVERE STORMS. MEDIUM COVERAGE IN TSRA OVER THE
TERMINALS AND EXACT TIMING.
* MEDIUM CONFIDENCE IN COVERAGE AND TIMING OF -SHRA AND VCTS EARLY
SUNDAY MORNING.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR. WX NIL.
MONDAY...VFR. WX NIL.
TUESDAY...SLIGHT CHANCE TSRA IN THE AFTERNOON.
WEDNESDAY...VFR. WX NIL.
THURSDAY...CHANCE TSRA.
FRIDAY...VFR/WX NIL EARLY. CHANCE TSRA OVERNIGHT.
KREIN
&&
.MARINE...
233 PM CDT
THE MAIN CONCERNS OVER LAKE MICHGAN WILL BE THE THREAT OF SEVERE
THUNDERSTORMS THIS AFTERNOON AND EVENING. CURRENTLY A LARGE AREA
OF THUNDERSTORMS DEVELOPING OVER SOUTHERN WISCONSIN AND NORTHERN
ILLINOIS AND THIS ACTIVITY WILL MOVE OVER SOUTHERN LAKE MICHIGAN
THIS AFTERNOON INTO THE EVENING. EXPECT STRONG WINDS AND LOCALLY
HIGH WAVES IN AND AROUND THE STORMS.
OTHERWISE...THINGS SHOULD QUIET DOWN ON THE LAKE BY SUNDAY
FOLLOWING A COLD FRONTAL PASSAGE.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 UNTIL 8 PM SATURDAY.
FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL MIDNIGHT SUNDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL
MIDNIGHT SUNDAY.
HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 8 PM
SATURDAY.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
230 PM CDT SAT JUL 18 2015
.SHORT TERM...
957 AM CDT
A FLASH FLOOD WATCH WAS ISSUED FOR THE ENTIRE WARNING AREA DUE TO
CONCERNS ABOUT TORRENTIAL RAINFALL RATES.
OUTFLOW BOUNDARY FROM EARLIER WISCONSIN MCS HAS SAGGED SOUTH INTO
NORTHERN CWA AND IS BEGINNING TO STALL OUT OVER NORTH CENTRAL
ILLINOIS. OVER NORTHEAST ILLINOIS THE LAKE HAS AUGMENTED THE
BOUNDARY AND PROVIDED SOME ADDITIONAL SOUTHWARD ACCELERATION
ADJACENT TO LAKE MICHIGAN. ANTICIPATE THE BOUNDARY WILL STALL OUT
EVEN OVER NORTHEAST ILLINOIS AND PROBABLY RETREAT NORTH DURING THE
DAY AS SUNSHINE ALLOWS FOR STRONG HEATING/MIXING AND A MODEST
SOUTHWEST WIND DEVELOPS. DESPITE THE INITIALLY COOLER AIR NEAR THE
LAKE...STILL FEEL THERE IS A REASONABLY GOOD CHANCE THAT THE
BOUNDARY WILL STALL/RETREAT ENOUGH TO PROVIDE FOR A HOT/HUMID
AFTERNOON WITH HEAT INDICES ABOVE 100 OVER EVEN NORTHEAST ILLINOIS
SO NOT PLANNING TO CHANGE HEAT ADVISORY ANY THIS MORNING. MAY
BROADEN THE RANGE OF HEAT INDICES TO 100 TO 110 AS CLOUDS FROM
IA/MO MCS MAY LIMIT THE HEAT SOME THIS AFTERNOON...MAINLY WESTERN
CWA.
AMPLE SUNSHINE IN ADVANCE OF ANY CLOUDINESS FROM MO/IA CONVECTION
WILL ALLOW FOR RAPID HEATING AND DESTABILIZATION ACROSS THE CWA
THROUGH EARLY AFTERNOON...BUT PARTICULARLY TO THE SOUTH OF THE WI
MCS REMNANT OUTFLOW BOUNDARY. DVN/ILX MORNING SOUNDINGS BOTH SHOW
MODERATELY STEEP LOW/MID LEVEL LAPSE RATES AND AS TEMPS/DEWPOINTS
RISE TOWARD PROJECTED HIGHS REGION SHOULD BE LEFT UNCAPPED BY
EARLY AFTERNOON...WITH MODIFIED ILX SOUNDING SUPPORTING SHOWING
MLCAPE VALUES NEARING 4000 J/KG BY EARLY THIS AFTERNOON WITH SFC
PARCEL OF 90/77...WHICH APPEARS EASILY ATTAINABLE IN THE WARM
SECTOR TODAY.
MORNING UPPER AIR ANALYSIS AND ACARS DATA SHOW 35-45KT FLOW
AROUND 6KM FROM IA INTO NORTHERN ILLINOIS WHICH WILL RESULT IN
0-6KM SHEAR VALUES OF AT LEAST AROUND 30KT...WHICH COMBINED WITH
SUCH STRONG INSTABILITY WOULD SUPPORT ORGANIZED CONVECTION AND
PERHAPS EVEN A SUPERCELL THREAT...ESPECIALLY IF ANY CELLS WERE TO
RIDE OUTFLOW BOUNDARY. PRIMARY SEVERE THREAT WOULD BE LARGE HAIL
AND DAMAGING WINDS...THOUGH CANNOT COMPLETELY RULE OUT A TORNADO
THREAT WITH ANY CELLS INTERACTING WITH BOUNDARIES GIVEN THE STRONG
LOW LEVEL CAPE AND LOW LCL HEIGHTS. OBVIOUSLY STILL SITTING IN A
VERY MOIST ENVIRONMENT SO HEAVY RAINFALL AND LOCALIZED FLASH
FLOODING IS ALSO A THREAT.
PLAN TO UPDATE GRIDS SHORTLY TO INTRODUCE POPS FOR THIS AFTERNOON
SPREADING THEM FROM WEST TO EAST. GENERALLY LIKE THE TRENDS IN THE
EXPERIMENTAL HRRR WHICH SHOWS STORMS DEVELOPING IN EAST AND
NORTHEAST OF THE IA/MO DECAYING MCS AND OUTFLOW BOUNDARY. WITH
MODEL GUIDANCE ALL OVER THE PLACE AND CAMS NOT HANDLING ONGOING
SITUATION WELL CONFIDENCE IS DIMINISHED...BUT CERTAINLY
OBSERVATIONAL TRENDS SUPPORT THE ABOVE FORECAST SCENARIO AND PLAN
TO INCREASE POPS INTO THE HIGH END CHANCE RANGE FOR NOW.
DESPITE THE HIGHER STORM CHANCES TODAY...PRIOR TO ANY STORMS HEAT
INDICES ARE LIKELY TO REACH 100 TO POTENTIALLY 110 DEGREES TODAY
SO LEAVING THE HEAT HEADLINES UNCHANGED.
GRIDS ARE GOING TO TAKE A LOT OF SURGERY TO REFLECT THE ABOVE
THINKING SINCE THERE IS NO REAL GUIDANCE REFLECTING CURRENT TRENDS
OR ABOVE THINKING...BUT FORECAST UPDATES ARE FORTHCOMING.
IZZI
&&
.LONG TERM...
227 PM CDT
TOMORROW THROUGH TUESDAY...
A COLD FRONT WILL SHIFT ACROSS THE REGION ON SUNDAY. HOWEVER...IT
NOW APPEARS THAT THE BETTER THREAT FOR STRONG TO SEVERE STORMS ON
SUNDAY AFTERNOON MAY REMAIN SOUTH OF MY AREA ALL TOGETHER AS SHOWERS
AND THUNDERSTORMS TONIGHT INTO EARLY SUNDAY LOOK TO SHIFT THE MAIN
FOCUS FARTHER SOUTH THAN ORIGINALLY THOUGHT. WITH THIS IN MIND I
HAVE BACKED OFF ON POPS...ESPECIALLY SUNDAY AFTERNOON...WHEN I HAVE
FOCUSED THE HIGHEST POPS ACROSS MY EXTREME SOUTHERN COUNTIES IN
CENTRAL ILLINOIS.
ANOTHER CHANCE OF THUNDERSTORMS...WITH HEAVY RAINFALL AND POSSIBLY
STRONG WILL RETURN TO THE FORECAST ON MONDAY AS ANOTHER MID LEVEL
DISTURBANCE MOVES ACROSS THE AREA. GUIDANCE HAS NOT HAD THE BEST
HANDLE ON THIS DISTURBANCE THE PAST COUPLE OF RUNS...WITH IT
PREVIOUSLY APPEARING THAT THE MAIN THREAT OF STORMS COULD STAY SOUTH
OF THE AREA. HOWEVER...WITH THE POTENTIAL OF A FARTHER NORTH FOCUS
OF STORMS...I HAVE INCLUDED A CHANCE OF STORMS ON MONDAY...WITH
SLIGHTLY HIGHER POPS ACROSS THE SOUTHERN HALF OF THE AREA.
SURFACE HIGH PRESSURE IS EXPECTED TO BUILD OVER THE AREA ON
TUESDAY...SO IT APPEARS THAT TUESDAY COULD BE A DRY AND COOLER DAY
ACROSS THE AREA.
KJB
TUESDAY NIGHT THROUGH FRIDAY...
NORTHWEST FLOW ALOFT CONTINUES TUESDAY NIGHT THROUGH MID WEEK WITH A
FEW UPPER LEVEL WAVES MOVING THROUGH OVER THE END OF THE WEEK. AT
THE SURFACE HIGH PRESSURE SPREADS EAST OVER THE REGION TUESDAY NIGHT
AND THEN SHIFTS EAST OVER THE APPALACHIANS THURSDAY.
LOOKING AT A SHORT PERIOD OF DRY CONDITIONS THROUGH AT LEAST
WEDNESDAY NIGHT...POSSIBLY THROUGH THE END OF THE WEEK IF THE ECMWF
IS RIGHT. THE GFS FEATURES PRECIP ON THE BACKSIDE OF THE HIGH
THURSDAY NIGHT INTO FRIDAY. CONFIDENCE IS LOW SO KEPT THE CHANCE OF
PRECIP IN THE LOW END CHANCE OR LOWER RANGE.
FOR TEMPS...HAVE A SLOW WARMING TREND WITH TEMPS IN THE LOW TO MID
80S AND TEMPS COULD BE WARMER THAN FORECAST DEPENDING ON THE AMOUNT
OF PRECIP THAT OCCURS. THE GFS IS A BIT WARMER WITH 925MB TEMPS IN
THE MID TO UPPER 20S WHICH WOULD SUGGEST HIGH TEMPS IN THE 90S.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SOUTHEAST WINDS CONTINUE TO VEER TO SOUTHWEST THIS AFTN. GUSTS
DIMINISH THIS EVENING.
* PERIODS OF TSRA WITH HEAVY RAIN EXPECTED THIS AFTN. STRONG TO
SEVERE STORMS PROBABLE.
* ANOTHER ROUND OF SHRA AND PERHAPS SOME EMBEDDED TSRA EARLY
SUNDAY MORNING.
JEE
//DISCUSSION...UPDATED 18Z...
A GUST FRONT FROM THE CONVECTION EARLIER THIS MORNING HAS STALLED
FROM BELVIDERE IL THROUGH HIGHLAND INDIANA. WINDS NORTHEAST OF THE
BOUNDARY ARE SLOWLY VEERING FROM NE OR E TO SE...AND EXPECTING
SOUTHWEST WINDS EARLY THIS AFTN. CONDITIONS CONTINUE TO IMPROVE
FOR STORMS. STORMS SHOULD FORM ALONG THE BOUNDARY AND AHEAD OF THE
UPPER LEVEL DISTURBANCE CURRENTLY OVER IOWA THAT IS SHIFTING EAST.
STRONG TO SEVERE STORMS ARE PROBABLE. WHILE CONFIDENCE IS MEDIUM
IN COVERAGE...TIMING...AND EXACT LOCATION...HAVE HIGH CONFIDENCE
THAT THERE SHOULD BE ENOUGH CONVECTION AROUND TO DISRUPT AIR
TRAFFIC. ALL STORMS WILL ALSO PRODUCE TORRENTIAL DOWNPOURS WHICH
WILL LIMIT VISIBILITY.
TSRA PUSHES EAST OF THE TERMINALS THIS EVENING WITH SOUTHWEST
WINDS LESS THAN 15 KT. A COLD FRONT SINKS SOUTHEAST THROUGH THE
REGION SUNDAY MORNING. SHOWERS AND A FEW EMBEDDED THUNDERSTORMS
SHOULD FORM AHEAD OF IT BUT THE NUMBER OF THUNDERSTORMS WILL BE
LIMITED BY HOW STABLE WE ARE BEHIND THIS AFTERNOON/S
THUNDERSTORMS. WINDS SHIFT TO NORTHWEST BEHIND THE COLD FRONT WITH
VFR CONDITIONS.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN WIND FORECAST.
* MEDIUM-HIGH CONFIDENCE IN TS OCCURRING AND THE POSSIBILITY OF
STRONG TO SEVERE STORMS. MEDIUM COVERAGE IN TSRA OVER THE
TERMINALS AND EXACT TIMING.
* MEDIUM CONFIDENCE IN COVERAGE AND TIMING OF -SHRA AND VCTS EARLY
SUNDAY MORNING.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR. WX NIL.
MONDAY...VFR. WX NIL.
TUESDAY...SLIGHT CHANCE TSRA IN THE AFTERNOON.
WEDNESDAY...VFR. WX NIL.
THURSDAY...CHANCE TSRA.
FRIDAY...VFR/WX NIL EARLY. CHANCE TSRA OVERNIGHT.
KREIN
&&
.MARINE...
350 AM CDT
HIGH DEW POINT AIR MAY CONTINUE TO PRODUCE SOME FOG OVER THE OPEN
WATERS OF THE LAKE INTO EARLY SATURDAY MORNING. OTHERWISE...
SOUTH TO SOUTHWEST FLOW OVER THE LAKE SHOULD INCREASE TO ARND
15-25KT THIS AFTERNOON AND TONIGHT AS A COLD FRONT ASSOCIATED WITH
LOW PRESSURE MOVING ACROSS THE CANADIAN PRAIRIES TO HUDSON BAY.
THE FRONT SHOULD PUSH ACROSS THE LAKE LATE SATURDAY NIGHT INTO
SUNDAY MORNING. WEAK HIGH PRESSURE BUILDING IN BEHIND THE FRONT
WILL BEING DIMINISHING WLY FLOW TO THE LAKE...BUT ANOTHER COLD
FRONT DROPPING THROUGH THE UPPER MISSISSIPPI VALLEY MONDAY WILL
BRING ANOTHER ROUND OF INCREASING SWLY WINDS INTO MONDAY EVENING
BEFORE THE COLD FRONT PUSHES ACROSS THE LAKE LATE MONDAY NIGHT
INTO EARLY TUESDAY MORNING. A LARGE AREA OF WEAK HIGH PRESSURE IS
EXPECTED TO SPREAD ACROSS THE GREAT LAKES REGION BY TUESDAY NIGHT.
THE HIGH PRESSURE SHOULD REMAIN NEARLY STATIONARY OVER THE GREAT
LAKES REGION THROUGH MUCH OF NEXT WEEK...BRINGING AN EXTENDED
PERIOD OF LIGHT AND VARIABLE WINDS.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 UNTIL 8 PM SATURDAY.
FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL MIDNIGHT SUNDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL
MIDNIGHT SUNDAY.
HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 8 PM
SATURDAY.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
1252 PM CDT SAT JUL 18 2015
.UPDATE...
ISSUED AT 1051 AM CDT SAT JUL 18 2015
MCS THAT DEVELOPED OVER SOUTHEAST NEBRASKA/NORTHWEST MISSOURI
EARLIER THIS MORNING CONTINUES TO TRACK EASTWARD AND IS NOW
APPROACHING THE MISSISSIPPI RIVER. IR SATELLITE HAS SHOWN WARMING
CLOUD TOPS WHILE 15-MINUTE LIGHTNING DATA HAS BEEN CONSISTENTLY
DECREASING OVER THE PAST COUPLE OF HOURS. DESPITE THE DISTINCT
DIURNAL WEAKENING TREND...LIGHT RAIN IS SPILLING INTO WEST-CENTRAL
ILLINOIS. MOST MODELS ARE NOT HANDLING THE CURRENT SITUATION
PARTICULARLY WELL...WITH THE 12Z NAM SHOWING THE SYSTEM COMPLETELY
DISSIPATING BEFORE IT REACHES CENTRAL ILLINOIS. MEANWHILE...THE
LATEST HRRR TAKES THE DIMINISHING PRECIP AREA INTO THE HEART OF
THE KILX CWA EARLY THIS AFTERNOON...WITH WIDELY SCATTERED
THUNDERSTORMS DEVELOPING AHEAD OF THE SYSTEM ACROSS EAST-CENTRAL
AND SOUTHEAST ILLINOIS. THINK THIS MAY BE A LITTLE TOO
AGGRESSIVE...SO HAVE FOLLOWED THE RAPID REFRESH MOST CLOSELY FOR
THE SHORT-TERM FORECAST. AS A RESULT...HAVE INCREASED POPS ACROSS
THE W/SW CWA GENERALLY WEST OF THE I-55 CORRIDOR LATE THIS MORNING
INTO THE EARLY AFTERNOON AS THE SYSTEM CROSSES THE MISSISSIPPI
RIVER. THINK IT WILL GRADUALLY FIZZLE...LEAVING BEHIND A MID/HIGH
OVERCAST THROUGH MID-AFTERNOON. FURTHER E/SE...THINK ISOLATED
THUNDERSTORMS WILL DEVELOP ALONG/E OF I-57 THIS AFTERNOON AS
OUTFLOW BOUNDARY INTERACTS WITH VERY UNSTABLE AIRMASS. MAIN STORY
TODAY WILL BE THE HEAT AND HUMIDITY. DESPITE CLOUD COVER FROM MCS
TEMPORARILY HALTING THE TEMP RISE LATE THIS MORNING INTO THE EARLY
AFTERNOON ACROSS THE WESTERN HALF OF THE AREA...A RETURN TO
PARTIAL SUNSHINE LATER IN THE DAY WILL RESULT IN HIGH TEMPS IN THE
LOWER TO MIDDLE 90S ACROSS THE BOARD. HEAT INDEX VALUES WILL
EXCEED ADVISORY CRITERIA...RANGING FROM 105 TO 110.
&&
.SHORT TERM...(TODAY)
ISSUED AT 332 AM CDT SAT JUL 18 2015
LATEST SURFACE ANALYSIS INDICATING A LARGE POOL OF MID TO UPPER 70
DEGREE DEW POINTS SITUATED OVER MOST OF CENTRAL IL WEST THROUGH
EASTERN IOWA. LARGE COMPLEX OF STORMS OVER MINNESOTA AND NORTHERN
IOWA INTO WESTERN WISCONSIN WILL TRACK EAST WITH MOST OF THE HIGH
RESOLUTION MODELS SUGGESTING A REMNANT OUTFLOW BOUNDARY WILL TRACK
EAST AND SOUTHEAST INTO NORTHERN IL BY THIS AFTERNOON AND EVENING.
MEANWHILE...A WEAK SHORTWAVE OVER EASTERN KS HAS HELPED TO PRODUCE
SOME SCATTERED CONVECTION OVER FAR NORTHWEST MISSOURI WITH THE
LATEST HRRR MODEL BRINGING SOME OF THAT PRECIP INTO OUR AREA THIS
AFTERNOON. NOT VERY CONFIDENT ON HOW THE HRRR MODEL HAS BEEN
HANDLING THE PRECIP/CONVECTIVE TRENDS OVER THE PAST SEVERAL DAYS,
ESPECIALLY AFTER ABOUT 6 TO 8 HOURS INTO THE FORECAST WHERE IT IS
WAY OVERBLOWN WITH RESPECT TO CONVECTIVE COVERAGE/INTENSITY. NOT
SURE IF THAT IS A BY-PRODUCT OF THE ADDED EVAPO-TRANSPIRATION OVER
THE MIDWEST...BUT IT HAS HAD A POOR TRACK RECORD FOR A FEW DAYS NOW
AND AM HESITANT TO TAKE ITS SOLUTION AND RUN WITH IT FOR LATER
TODAY.
WE WILL ADD SLIGHT CHANCES ACROSS THE SOUTHEAST THIS AFTERNOON AS
THE COMBINATION OF THE WEAK UPPER LEVEL WAVE TRACKING ACROSS THE
AREA THIS AFTERNOON COMBINED WITH PEAK HEATING AND MIXED LAYER CAPES
IN THE 2500-3000 J/G RANGE MAY BE ENOUGH TO PRODUCE ISOLATED STORMS.
FURTHER NORTH...CONVECTION THAT FIRED OVER NORTHEAST IL AND FINALLY
DISSPATED A FEW HOURS AGO LOOKS TO HAVE PUSHED A WEAK BOUNDARY TO
OUR FAR NORTHEAST COUNTIES...WHICH MAY BE ENOUGH TO PRODUCE AN
ISOLATED STORM THIS AFTERNOON. FOR NOW...WILL HOLD OFF MENTIONING
ANYTHING ACROSS OUR NORTHEAST BUT WE MAY NEED TO ADD LATER THIS
MORNING IF WE SEE SOME RATHER ROBUST CUMULUS DEVELOP ACROSS THE
AREA. FORECAST SOUNDINGS SHOWING AFTERNOON TEMPERATURES SHOULD WARM
SEVERAL DEGREES FROM WHAT WE SAW YESTERDAY AFTERNOOON...MEANING
LOW TO MID 90S FOR HIGHS AND HEAT INDEX VALUES OF 103-109 DEGREES.
WILL CONTINUE WITH THE HEAT ADVISORY THRU EARLY THIS EVENING.
THE COMPLEX OF STORMS TO OUR NORTHWEST EARLY THIS MORNING WILL TRACK
EAST AND A BIT SOUTHEAST AND AS MENTIONED ABOVE...WILL DRAG A OUTFLOW
BOUNDARY EAST/SE INTO NORTHERN IL LATE THIS AFTERNOON WHICH SHOULD BE
ENOUGH TO PRODUCE SCATTERED STORMS. MOST OF THE DETERMINISTIC MODELS
SUGGEST A SOUTHEAST PUSH TO THE STORM CLUSTER LATE THIS AFTERNOON SO
HAVE INCLUDED SLIGHT CHANCES IN OUR FAR NORTHWEST AFTER 21Z/4PM.
.LONG TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 332 AM CDT SAT JUL 18 2015
NOT MANY CHANGES IN THE MID RANGE OF THE FORECAST. WARM TEMPS
CONTINUE TONIGHT WITH PRECIP AND RESIDUAL CLOUD COVER KEEPING ANY
COOLING TO A MINIMUM AS PREFRONTAL PRECIP EDGES INTO THE REGION FROM
THE NW. FRONT ON TRACK TO PUSH THROUGH THE REGION ON SUNDAY AND SO
FAR, THE MODELS ARE PERSISTENT WITH SOME QPF WELL AHEAD OF THE SFC
BOUNDARY. IF THAT TREND CONTINUES, THE TEMPS IN THE FAR EAST AND
SOUTHEAST MAY REMAIN JUST COOL ENOUGH TO KEEP THE HEAT ADVISORY OUT
OF SUNDAY, ALTHOUGH SOME OF THE GUIDANCE HAS TEMPS IN THE SE RATHER
WARM ALONG AND SOUTH OF INTERSTATE 70. NOT ENTIRELY CONVINCED THAT
THE HEADLINE WILL NOT BE EXTENDED...BUT SO FAR THE HEAT INDICES ARE
REMAINING JUST SUB ADVSY LEVEL.
SUNDAY SHOWERS AND THUNDERSTORMS ALSO POTENTIALLY PROBLEMATIC WITH A
WARM AND HUMID AIRMASS OUT AHEAD OF A BOUNDARY, SPC HAS PUT ALL OF
CENTRAL ILLINOIS IN A SLIGHT RISK FOR DAY 2. OVERNIGHT STORMS
TONIGHT MAY ALSO PROVIDE SOME OUTFLOW BOUNDARIES FOR FOCUS OF MORE
STORMS BEFORE THE ACTUAL FROPA. SHEAR MAINLY UNIDIRECTIONAL AND
LIKELY TO BE MORE OF A WIND AND HAIL THREAT AT THIS TIME. A LOT OF
THE SEVERE THREAT WILL BE DICTATED BY THE PREV NIGHT CONVECTION AND
WHAT IS LEFTOVER SUNDAY MORNING TO LIMIT THE ATMOSPHERE RECHARGING.
SUNDAY NIGHT THE PRECIP SHIFTS TO THE SOUTH WITH THE BOUNDARY
SLOWING A IT LOSES ITS PUSH ALOFT AND GETS HUNG UP IN MORE PARALLEL
FLOW. MONDAY/MONDAY NIGHT WILL SEE THE HIGHER POPS IN THE SOUTH,
ALTHOUGH THERE HAS BEEN SOME WAVERING AS TO WHERE THE BOUNDARY WILL
STALL AS ANOTHER WAVE EJECTS OUT OF THE WEST AND RIPPLES UP THE
BOUNDARY REMAINS. SIMILAR PATTERN TO HOW THIS SUMMER HAS BEEN GOING
SO FAR. ECMWF LINGERING PRECIP INTO TUESDAY AND THE SUPERBLEND
HANGING ONTO THE PRECIP. WILL LIKELY REMOVE SHOULD THE OTHER MODELS
CONTINUE THE DRYING TREND TO TUES/WED AS A WEAK NWRLY FLOW
ESTABLISHES ALOFT. A GENERAL WARMING TREND CONTINUES THROUGH THE
WEEK AS THE NEXT PATTERN SHIFT LINES UP FOR THE END OF THE WEEK WITH
A RETURN OF PRECIP CHANCES MOVES IN THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1252 PM CDT SAT JUL 18 2015
CONVECTIVE INITIATION IS CURRENTLY TAKING PLACE AHEAD OF AN
APPROACHING SHORT-WAVE TROUGH ACROSS NORTHEAST IOWA INTO NORTHWEST
ILLINOIS. THESE STORMS SHOULD CONTINUE TO DEVELOP/EXPAND E/SE
ALONG AN OLD OUTFLOW BOUNDARY ACROSS NORTHERN ILLINOIS THIS
AFTERNOON. BASED ON LATEST RADAR IMAGERY AND POSITION OF
OUTFLOW...THINK THESE STORMS WILL STAY NORTH OF THE CENTRAL
ILLINOIS TERMINALS AS THEY TRACK INTO THE CHICAGO AREA BY MID TO
LATE AFTERNOON. AFTER THAT...ADDITIONAL STORMS WILL LIKELY DEVELOP
AHEAD OF A COLD FRONT APPROACHING FROM THE NORTHWEST LATER
TONIGHT. 12Z NAM SUGGESTS SCATTERED STORMS ARRIVING AT KPIA AFTER
03Z...THEN AFTER 09Z/10Z FURTHER SOUTHEAST AT KDEC AND KCMI. DUE
TO TIMING AND AREAL COVERAGE UNCERTAINTIES WILL ONLY INCLUDE VCTS
IN THE TAFS AT THIS TIME.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ILZ027>031-036>038-
040>057-061>063-066>068-071>073.
&&
$$
UPDATE...BARNES
SHORT TERM...SMITH
LONG TERM...HJS
AVIATION...BARNES
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1251 PM CDT SAT JUL 18 2015
.UPDATE...
957 AM CDT
OUTFLOW BOUNDARY FROM EARLIER WISCONSIN MCS HAS SAGGED SOUTH INTO
NORTHERN CWA AND IS BEGINNING TO STALL OUT OVER NORTH CENTRAL
ILLINOIS. OVER NORTHEAST ILLINOIS THE LAKE HAS AUGMENTED THE
BOUNDARY AND PROVIDED SOME ADDITIONAL SOUTHWARD ACCELERATION
ADJACENT TO LAKE MICHIGAN. ANTICIPATE THE BOUNDARY WILL STALL OUT
EVEN OVER NORTHEAST ILLINOIS AND PROBABLY RETREAT NORTH DURING THE
DAY AS SUNSHINE ALLOWS FOR STRONG HEATING/MIXING AND A MODEST
SOUTHWEST WIND DEVELOPS. DESPITE THE INITIALLY COOLER AIR NEAR THE
LAKE...STILL FEEL THERE IS A REASONABLY GOOD CHANCE THAT THE
BOUNDARY WILL STALL/RETREAT ENOUGH TO PROVIDE FOR A HOT/HUMID
AFTERNOON WITH HEAT INDICES ABOVE 100 OVER EVEN NORTHEAST ILLINOIS
SO NOT PLANNING TO CHANGE HEAT ADVISORY ANY THIS MORNING. MAY
BROADEN THE RANGE OF HEAT INDICES TO 100 TO 110 AS CLOUDS FROM
IA/MO MCS MAY LIMIT THE HEAT SOME THIS AFTERNOON...MAINLY WESTERN
CWA.
AMPLE SUNSHINE IN ADVANCE OF ANY CLOUDINESS FROM MO/IA CONVECTION
WILL ALLOW FOR RAPID HEATING AND DESTABILIZATION ACROSS THE CWA
THROUGH EARLY AFTERNOON...BUT PARTICULARLY TO THE SOUTH OF THE WI
MCS REMNANT OUTFLOW BOUNDARY. DVN/ILX MORNING SOUNDINGS BOTH SHOW
MODERATELY STEEP LOW/MID LEVEL LAPSE RATES AND AS TEMPS/DEWPOINTS
RISE TOWARD PROJECTED HIGHS REGION SHOULD BE LEFT UNCAPPED BY
EARLY AFTERNOON...WITH MODIFIED ILX SOUNDING SUPPORTING SHOWING
MLCAPE VALUES NEARING 4000 J/KG BY EARLY THIS AFTERNOON WITH SFC
PARCEL OF 90/77...WHICH APPEARS EASILY ATTAINABLE IN THE WARM
SECTOR TODAY.
MORNING UPPER AIR ANALYSIS AND ACARS DATA SHOW 35-45KT FLOW
AROUND 6KM FROM IA INTO NORTHERN ILLINOIS WHICH WILL RESULT IN
0-6KM SHEAR VALUES OF AT LEAST AROUND 30KT...WHICH COMBINED WITH
SUCH STRONG INSTABILITY WOULD SUPPORT ORGANIZED CONVECTION AND
PERHAPS EVEN A SUPERCELL THREAT...ESPECIALLY IF ANY CELLS WERE TO
RIDE OUTFLOW BOUNDARY. PRIMARY SEVERE THREAT WOULD BE LARGE HAIL
AND DAMAGING WINDS...THOUGH CANNOT COMPLETELY RULE OUT A TORNADO
THREAT WITH ANY CELLS INTERACTING WITH BOUNDARIES GIVEN THE STRONG
LOW LEVEL CAPE AND LOW LCL HEIGHTS. OBVIOUSLY STILL SITTING IN A
VERY MOIST ENVIRONMENT SO HEAVY RAINFALL AND LOCALIZED FLASH
FLOODING IS ALSO A THREAT.
PLAN TO UPDATE GRIDS SHORTLY TO INTRODUCE POPS FOR THIS AFTERNOON
SPREADING THEM FROM WEST TO EAST. GENERALLY LIKE THE TRENDS IN THE
EXPERIMENTAL HRRR WHICH SHOWS STORMS DEVELOPING IN EAST AND
NORTHEAST OF THE IA/MO DECAYING MCS AND OUTFLOW BOUNDARY. WITH
MODEL GUIDANCE ALL OVER THE PLACE AND CAMS NOT HANDLING ONGOING
SITUATION WELL CONFIDENCE IS DIMINISHED...BUT CERTAINLY
OBSERVATIONAL TRENDS SUPPORT THE ABOVE FORECAST SCENARIO AND PLAN
TO INCREASE POPS INTO THE HIGH END CHANCE RANGE FOR NOW.
DESPITE THE HIGHER STORM CHANCES TODAY...PRIOR TO ANY STORMS HEAT
INDICES ARE LIKELY TO REACH 100 TO POTENTIALLY 110 DEGREES TODAY
SO LEAVING THE HEAT HEADLINES UNCHANGED.
GRIDS ARE GOING TO TAKE A LOT OF SURGERY TO REFLECT THE ABOVE
THINKING SINCE THERE IS NO REAL GUIDANCE REFLECTING CURRENT TRENDS
OR ABOVE THINKING...BUT FORECAST UPDATES ARE FORTHCOMING.
IZZI
&&
.SHORT TERM...
408 AM CDT
TODAY THROUGH SUNDAY...
HEAT...HUMIDITY AND TIMING/COVERAGE OF THUNDERSTORMS ARE THE MAIN
FORECAST CONCERNS IN THE SHORT TERM PERIOD.
A VERY WARM AND HUMID AIR MASS REMAINS IN PLACE ACROSS THE
FORECAST AREA EARLY THIS MORNING...WITH LOW LEVEL THERMAL RIDGE TO
BUILD INTO THE REGION TODAY ON PERSISTENT SOUTH-SOUTHWEST LOW
LEVEL FLOW. LOW LEVEL THERMAL PROGS FROM VARIOUS MODELS SUPPORT
AFTERNOON TEMPS IN THE LOW-MID 90S ACROSS THE CWA...WITH DEW
POINTS IN THE MID-UPPER 70S EXPECTED TO YIELD PEAK AFTERNOON HEAT
INDICES IN THE 105-110 DEGREE RANGE. A HEAT ADVISORY REMAINS IN
EFFECT FOR THE ENTIRE CWA WITH NO CHANGES AT THIS TIME.
SOME COMPLICATIONS EXIST WITH THE FORECAST HOWEVER...PRIMARILY
WITH THE POTENTIAL FOR OUTFLOW FROM MCS CURRENTLY TRACKING ACROSS
WISCONSIN AND ALSO WITH THE POTENTIAL FOR THUNDERSTORMS ACROSS
PORTIONS OF THE CWA TODAY. CONVECTION-ALLOWING GUIDANCE HAS NOT
BEEN HANDLING THE UPPER MIDWEST MCS VERY WELL OVERNIGHT...THOUGH
SOME MODELS PARTICULARLY THE 00Z ARW/NMM-EAST RUNS DO DEPICT A
SOMEWHAT SIMILAR BOWING MCS ACROSS WI...TURNING IT SOUTHEAST A BIT
ACROSS LAKE MICHIGAN THIS MORNING. THIS SEEMS FAIRLY
REASONABLE...AS SPC MESOANALYSIS DEPICTS AN MUCAPE AXIS OF
2000-4000 J/KG FROM THE UPPER MISSISSIPPI VALLEY SOUTHEAST INTO
NORTHERN IL AT 08Z...REASONABLY STEEP MID-LEVEL LAPSE RATES...AND
A 850-300 MB THICKNESS GRADIENT WHICH WOULD FAVOR A SOUTHEASTWARD
PROPAGATION. THE QUESTION IS HOW FAR SOUTH CONVECTION DEVELOPS
ALONG THE IL/WI BORDER AREA THIS MORNING...AND HOW MUCH OF AN
EFFECT OUTFLOW BOUNDARIES NOTED ACROSS EASTERN IA AND LIKELY FROM
SOUTHERN WI WILL HAVE ON OUR TEMP AND DEW POINT TRENDS TODAY.
CURRENT THINKING IS THAT SCATTERED STORMS ALONG SOUTHERN PERIPHERY
OF THE MCS MAY SCRAPE ALONG THE IL/WI BORDER AREA EARLY THIS
AM...MOVING EAST OF THE THE AREA BY MID-LATE MORNING WHICH SHOULD
ALLOW DISSIPATION OF HIGH CLOUDS AND RECOVERY OF TEMPS AND DEW
POINTS BACK INTO FORECAST RANGE THIS AFTERNOON.
ADDITIONAL THUNDERSTORMS ARE EXPECTED BY THIS EVENING...AS A COLD
FRONT TRAILING FROM LOW PRESSURE OVER ONTARIO APPROACHES AND
EVENTUALLY PASSES ON SUNDAY. WHILE MOST GUIDANCE DEPICTS A
SCENARIO OF STORMS INITIATING ALONG/AHEAD OF THE FRONT ACROSS
WISCONSIN AND IOWA THIS AFTERNOON AND MOVING INTO THE AREA THIS
EVENING... LINGERING OUTFLOW BOUNDARIES MAY PROVIDE FOCUS FOR
ISOLATED TO SCATTERED STORMS TO DEVELOP OVER PORTIONS OF THE AREA
THIS AFTERNOON. ONE POSSIBLE FOCUS WOULD BE THE OUTFLOW BOUNDARY
FROM THIS MORNINGS MCS...WHICH WILL LIKELY BE SOMEWHERE OVER FAR
NORTHERN IL THIS AFTERNOON. THUS HAVE ADDED SOME CHANCE POPS BY
EARLY THIS AFTERNOON ACROSS NORTHERN IL. THUNDERSTORM CHANCES WILL
CONTINUE TONIGHT AS THE FRONT MOVES SLOWLY INTO THE REGION...AS
WELL AS ON SUNDAY AS THE BOUNDARY SAGS SOUTH AND EVENTUALLY
SETTLES SOUTH OF THE AREA SUNDAY EVENING. THE WARM/MOIST AIR
MASS...COMBINED WITH OUR LOCATION ALONG THE SOUTHERN PERIPHERY OF
FASTER WESTERLY FLOW ALOFT...WILL SET THE STAGE FOR THE POTENTIAL
FOR SEVERE THUNDERSTORMS MAINLY THIS AFTERNOON/EVENING...AND AGAIN
SUNDAY AFTERNOON. THE ENTIRE CWA IS IN SPC DAY 1 SLIGHT RISK...AND
A DAY 2 SLIGHT RISK MAINLY ACROSS THE SOUTHERN HALF. DAMAGING
WINDS WILL BE THE PRIMARY SEVERE HAZARD...THOUGH LOCALLY BACKED
WINDS ALONG OUTFLOW BOUNDARIES WOULD PRESENT A LOW TORNADO RISK AS
WELL. HIGH PWAT AIRMASS WILL CONTINUE TO PRODUCE TORRENTIAL
RAINFALL AND POTENTIAL FLOODING WITH STORMS AS WELL.
RATZER
&&
.LONG TERM...
415 AM CDT
SUNDAY NIGHT THROUGH FRIDAY...
FRONT SLIPS SOUTH OF AREA SUNDAY NIGHT WITH THUNDERSTORM THREAT
ENDING FROM NORTH TO SOUTH DURING THE EVENING ACROSS THE SOUTHEAST
HALF OF THE FORECAST AREA. WEAK HIGH PRESSURE SPREADS ACROSS CENTRAL
IL AND IN BEHIND THE FRONT LATER SUNDAY NIGHT.
FAST WEST-NORTHWEST FLOW ALOFT CONTINUES HOWEVER...WITH A SHORT WAVE
PROGGED TO DIG ACROSS THE WESTERN LAKES AREA MONDAY NIGHT INTO
TUESDAY MORNING...WITH THE PASSAGE OF ANOTHER WEAKER COLD FRONT.
WEAK RETURN FLOW SETS UP MONDAY NIGHT...WITH GUIDANCE SHOWING QUITE
A BIT OF SPREAD IN TIMING AND COVERAGE OF PRECIP INTO TUESDAY. HAVE
MAINTAINED SLIGHT CHANCE POPS DURING THE DAY TUESDAY FROM PREVIOUS
FORECAST FOR NOW WITH HOPEFULLY BETTER MODEL AGREEMENT IN THE
DETAILS AS THE PERIOD DRAWS NEARER.
SURFACE HIGH PRESSURE ONCE AGAIN BUILDS INTO THE AREA TUESDAY NIGHT
AND WEDNESDAY...AS UPPER RIDGE BEGINS TO REBUILD ACROSS THE CENTRAL
CONUS. THIS LOOKS TO PROVIDE A DRY MID-WEEK PERIOD WITH
NEAR/SLIGHTLY BELOW NORMAL TEMPS GENERALLY IN THE LOW 80S. MEDIUM
RANGE GUIDANCE ARE THEN IN DECENT AGREEMENT IN BRINGING A SHORT WAVE
THROUGH THE RIDGE AND ACROSS THE MIDWEST THURSDAY...WITH RETURN FLOW
AND THE NEXT CHANCE OF SHOWER/THUNDERSTORMS DEVELOPING IN ADVANCE AS
THE SURFACE HIGH MOVES OFF TO THE EAST.
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SOUTHEAST WINDS CONTINUE TO VEER TO SOUTHWEST THIS AFTN. GUSTS
DIMINISH THIS EVENING.
* PERIODS OF TSRA WITH HEAVY RAIN EXPECTED THIS AFTN. STRONG TO
SEVERE STORMS PROBABLE.
* ANOTHER ROUND OF SHRA AND PERHAPS SOME EMBEDDED TSRA EARLY
SUNDAY MORNING.
JEE
//DISCUSSION...UPDATED 18Z...
A GUST FRONT FROM THE CONVECTION EARLIER THIS MORNING HAS STALLED
FROM BELVIDERE IL THROUGH HIGHLAND INDIANA. WINDS NORTHEAST OF THE
BOUNDARY ARE SLOWLY VEERING FROM NE OR E TO SE...AND EXPECTING
SOUTHWEST WINDS EARLY THIS AFTN. CONDITIONS CONTINUE TO IMPROVE
FOR STORMS. STORMS SHOULD FORM ALONG THE BOUNDARY AND AHEAD OF THE
UPPER LEVEL DISTURBANCE CURRENTLY OVER IOWA THAT IS SHIFTING EAST.
STRONG TO SEVERE STORMS ARE PROBABLE. WHILE CONFIDENCE IS MEDIUM
IN COVERAGE...TIMING...AND EXACT LOCATION...HAVE HIGH CONFIDENCE
THAT THERE SHOULD BE ENOUGH CONVECTION AROUND TO DISRUPT AIR
TRAFFIC. ALL STORMS WILL ALSO PRODUCE TORRENTIAL DOWNPOURS WHICH
WILL LIMIT VISIBILITY.
TSRA PUSHES EAST OF THE TERMINALS THIS EVENING WITH SOUTHWEST
WINDS LESS THAN 15 KT. A COLD FRONT SINKS SOUTHEAST THROUGH THE
REGION SUNDAY MORNING. SHOWERS AND A FEW EMBEDDED THUNDERSTORMS
SHOULD FORM AHEAD OF IT BUT THE NUMBER OF THUNDERSTORMS WILL BE
LIMITED BY HOW STABLE WE ARE BEHIND THIS AFTERNOON/S
THUNDERSTORMS. WINDS SHIFT TO NORTHWEST BEHIND THE COLD FRONT WITH
VFR CONDITIONS.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN WIND FORECAST.
* MEDIUM-HIGH CONFIDENCE IN TS OCCURRING AND THE POSSIBILITY OF
STRONG TO SEVERE STORMS. MEDIUM COVERAGE IN TSRA OVER THE
TERMINALS AND EXACT TIMING.
* MEDIUM CONFIDENCE IN COVERAGE AND TIMING OF -SHRA AND VCTS EARLY
SUNDAY MORNING.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR. WX NIL.
MONDAY...VFR. WX NIL.
TUESDAY...SLIGHT CHANCE TSRA IN THE AFTERNOON.
WEDNESDAY...VFR. WX NIL.
THURSDAY...CHANCE TSRA.
FRIDAY...VFR/WX NIL EARLY. CHANCE TSRA OVERNIGHT.
KREIN
&&
.MARINE...
350 AM CDT
HIGH DEW POINT AIR MAY CONTINUE TO PRODUCE SOME FOG OVER THE OPEN
WATERS OF THE LAKE INTO EARLY SATURDAY MORNING. OTHERWISE...
SOUTH TO SOUTHWEST FLOW OVER THE LAKE SHOULD INCREASE TO ARND
15-25KT THIS AFTERNOON AND TONIGHT AS A COLD FRONT ASSOCIATED WITH
LOW PRESSURE MOVING ACROSS THE CANADIAN PRAIRIES TO HUDSON BAY.
THE FRONT SHOULD PUSH ACROSS THE LAKE LATE SATURDAY NIGHT INTO
SUNDAY MORNING. WEAK HIGH PRESSURE BUILDING IN BEHIND THE FRONT
WILL BEING DIMINISHING WLY FLOW TO THE LAKE...BUT ANOTHER COLD
FRONT DROPPING THROUGH THE UPPER MISSISSIPPI VALLEY MONDAY WILL
BRING ANOTHER ROUND OF INCREASING SWLY WINDS INTO MONDAY EVENING
BEFORE THE COLD FRONT PUSHES ACROSS THE LAKE LATE MONDAY NIGHT
INTO EARLY TUESDAY MORNING. A LARGE AREA OF WEAK HIGH PRESSURE IS
EXPECTED TO SPREAD ACROSS THE GREAT LAKES REGION BY TUESDAY NIGHT.
THE HIGH PRESSURE SHOULD REMAIN NEARLY STATIONARY OVER THE GREAT
LAKES REGION THROUGH MUCH OF NEXT WEEK...BRINGING AN EXTENDED
PERIOD OF LIGHT AND VARIABLE WINDS.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 UNTIL 8 PM SATURDAY.
IN...HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 8 PM
SATURDAY.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1113 AM CDT SAT JUL 18 2015
.UPDATE...
957 AM CDT
OUTFLOW BOUNDARY FROM EARLIER WISCONSIN MCS HAS SAGGED SOUTH INTO
NORTHERN CWA AND IS BEGINNING TO STALL OUT OVER NORTH CENTRAL
ILLINOIS. OVER NORTHEAST ILLINOIS THE LAKE HAS AUGMENTED THE
BOUNDARY AND PROVIDED SOME ADDITIONAL SOUTHWARD ACCELERATION
ADJACENT TO LAKE MICHIGAN. ANTICIPATE THE BOUNDARY WILL STALL OUT
EVEN OVER NORTHEAST ILLINOIS AND PROBABLY RETREAT NORTH DURING THE
DAY AS SUNSHINE ALLOWS FOR STRONG HEATING/MIXING AND A MODEST
SOUTHWEST WIND DEVELOPS. DESPITE THE INITIALLY COOLER AIR NEAR THE
LAKE...STILL FEEL THERE IS A REASONABLY GOOD CHANCE THAT THE
BOUNDARY WILL STALL/RETREAT ENOUGH TO PROVIDE FOR A HOT/HUMID
AFTERNOON WITH HEAT INDICES ABOVE 100 OVER EVEN NORTHEAST ILLINOIS
SO NOT PLANNING TO CHANGE HEAT ADVISORY ANY THIS MORNING. MAY
BROADEN THE RANGE OF HEAT INDICES TO 100 TO 110 AS CLOUDS FROM
IA/MO MCS MAY LIMIT THE HEAT SOME THIS AFTERNOON...MAINLY WESTERN
CWA.
AMPLE SUNSHINE IN ADVANCE OF ANY CLOUDINESS FROM MO/IA CONVECTION
WILL ALLOW FOR RAPID HEATING AND DESTABILIZATION ACROSS THE CWA
THROUGH EARLY AFTERNOON...BUT PARTICULARLY TO THE SOUTH OF THE WI
MCS REMNANT OUTFLOW BOUNDARY. DVN/ILX MORNING SOUNDINGS BOTH SHOW
MODERATELY STEEP LOW/MID LEVEL LAPSE RATES AND AS TEMPS/DEWPOINTS
RISE TOWARD PROJECTED HIGHS REGION SHOULD BE LEFT UNCAPPED BY
EARLY AFTERNOON...WITH MODIFIED ILX SOUNDING SUPPORTING SHOWING
MLCAPE VALUES NEARING 4000 J/KG BY EARLY THIS AFTERNOON WITH SFC
PARCEL OF 90/77...WHICH APPEARS EASILY ATTAINABLE IN THE WARM
SECTOR TODAY.
MORNING UPPER AIR ANALYSIS AND ACARS DATA SHOW 35-45KT FLOW
AROUND 6KM FROM IA INTO NORTHERN ILLINOIS WHICH WILL RESULT IN
0-6KM SHEAR VALUES OF AT LEAST AROUND 30KT...WHICH COMBINED WITH
SUCH STRONG INSTABILITY WOULD SUPPORT ORGANIZED CONVECTION AND
PERHAPS EVEN A SUPERCELL THREAT...ESPECIALLY IF ANY CELLS WERE TO
RIDE OUTFLOW BOUNDARY. PRIMARY SEVERE THREAT WOULD BE LARGE HAIL
AND DAMAGING WINDS...THOUGH CANNOT COMPLETELY RULE OUT A TORNADO
THREAT WITH ANY CELLS INTERACTING WITH BOUNDARIES GIVEN THE STRONG
LOW LEVEL CAPE AND LOW LCL HEIGHTS. OBVIOUSLY STILL SITTING IN A
VERY MOIST ENVIRONMENT SO HEAVY RAINFALL AND LOCALIZED FLASH
FLOODING IS ALSO A THREAT.
PLAN TO UPDATE GRIDS SHORTLY TO INTRODUCE POPS FOR THIS AFTERNOON
SPREADING THEM FROM WEST TO EAST. GENERALLY LIKE THE TRENDS IN THE
EXPERIMENTAL HRRR WHICH SHOWS STORMS DEVELOPING IN EAST AND
NORTHEAST OF THE IA/MO DECAYING MCS AND OUTFLOW BOUNDARY. WITH
MODEL GUIDANCE ALL OVER THE PLACE AND CAMS NOT HANDLING ONGOING
SITUATION WELL CONFIDENCE IS DIMINISHED...BUT CERTAINLY
OBSERVATIONAL TRENDS SUPPORT THE ABOVE FORECAST SCENARIO AND PLAN
TO INCREASE POPS INTO THE HIGH END CHANCE RANGE FOR NOW.
DESPITE THE HIGHER STORM CHANCES TODAY...PRIOR TO ANY STORMS HEAT
INDICES ARE LIKELY TO REACH 100 TO POTENTIALLY 110 DEGREES TODAY
SO LEAVING THE HEAT HEADLINES UNCHANGED.
GRIDS ARE GOING TO TAKE A LOT OF SURGERY TO REFLECT THE ABOVE
THINKING SINCE THERE IS NO REAL GUIDANCE REFLECTING CURRENT TRENDS
OR ABOVE THINKING...BUT FORECAST UPDATES ARE FORTHCOMING.
IZZI
&&
.SHORT TERM...
408 AM CDT
TODAY THROUGH SUNDAY...
HEAT...HUMIDITY AND TIMING/COVERAGE OF THUNDERSTORMS ARE THE MAIN
FORECAST CONCERNS IN THE SHORT TERM PERIOD.
A VERY WARM AND HUMID AIR MASS REMAINS IN PLACE ACROSS THE
FORECAST AREA EARLY THIS MORNING...WITH LOW LEVEL THERMAL RIDGE TO
BUILD INTO THE REGION TODAY ON PERSISTENT SOUTH-SOUTHWEST LOW
LEVEL FLOW. LOW LEVEL THERMAL PROGS FROM VARIOUS MODELS SUPPORT
AFTERNOON TEMPS IN THE LOW-MID 90S ACROSS THE CWA...WITH DEW
POINTS IN THE MID-UPPER 70S EXPECTED TO YIELD PEAK AFTERNOON HEAT
INDICES IN THE 105-110 DEGREE RANGE. A HEAT ADVISORY REMAINS IN
EFFECT FOR THE ENTIRE CWA WITH NO CHANGES AT THIS TIME.
SOME COMPLICATIONS EXIST WITH THE FORECAST HOWEVER...PRIMARILY
WITH THE POTENTIAL FOR OUTFLOW FROM MCS CURRENTLY TRACKING ACROSS
WISCONSIN AND ALSO WITH THE POTENTIAL FOR THUNDERSTORMS ACROSS
PORTIONS OF THE CWA TODAY. CONVECTION-ALLOWING GUIDANCE HAS NOT
BEEN HANDLING THE UPPER MIDWEST MCS VERY WELL OVERNIGHT...THOUGH
SOME MODELS PARTICULARLY THE 00Z ARW/NMM-EAST RUNS DO DEPICT A
SOMEWHAT SIMILAR BOWING MCS ACROSS WI...TURNING IT SOUTHEAST A BIT
ACROSS LAKE MICHIGAN THIS MORNING. THIS SEEMS FAIRLY
REASONABLE...AS SPC MESOANALYSIS DEPICTS AN MUCAPE AXIS OF
2000-4000 J/KG FROM THE UPPER MISSISSIPPI VALLEY SOUTHEAST INTO
NORTHERN IL AT 08Z...REASONABLY STEEP MID-LEVEL LAPSE RATES...AND
A 850-300 MB THICKNESS GRADIENT WHICH WOULD FAVOR A SOUTHEASTWARD
PROPAGATION. THE QUESTION IS HOW FAR SOUTH CONVECTION DEVELOPS
ALONG THE IL/WI BORDER AREA THIS MORNING...AND HOW MUCH OF AN
EFFECT OUTFLOW BOUNDARIES NOTED ACROSS EASTERN IA AND LIKELY FROM
SOUTHERN WI WILL HAVE ON OUR TEMP AND DEW POINT TRENDS TODAY.
CURRENT THINKING IS THAT SCATTERED STORMS ALONG SOUTHERN PERIPHERY
OF THE MCS MAY SCRAPE ALONG THE IL/WI BORDER AREA EARLY THIS
AM...MOVING EAST OF THE THE AREA BY MID-LATE MORNING WHICH SHOULD
ALLOW DISSIPATION OF HIGH CLOUDS AND RECOVERY OF TEMPS AND DEW
POINTS BACK INTO FORECAST RANGE THIS AFTERNOON.
ADDITIONAL THUNDERSTORMS ARE EXPECTED BY THIS EVENING...AS A COLD
FRONT TRAILING FROM LOW PRESSURE OVER ONTARIO APPROACHES AND
EVENTUALLY PASSES ON SUNDAY. WHILE MOST GUIDANCE DEPICTS A
SCENARIO OF STORMS INITIATING ALONG/AHEAD OF THE FRONT ACROSS
WISCONSIN AND IOWA THIS AFTERNOON AND MOVING INTO THE AREA THIS
EVENING... LINGERING OUTFLOW BOUNDARIES MAY PROVIDE FOCUS FOR
ISOLATED TO SCATTERED STORMS TO DEVELOP OVER PORTIONS OF THE AREA
THIS AFTERNOON. ONE POSSIBLE FOCUS WOULD BE THE OUTFLOW BOUNDARY
FROM THIS MORNINGS MCS...WHICH WILL LIKELY BE SOMEWHERE OVER FAR
NORTHERN IL THIS AFTERNOON. THUS HAVE ADDED SOME CHANCE POPS BY
EARLY THIS AFTERNOON ACROSS NORTHERN IL. THUNDERSTORM CHANCES WILL
CONTINUE TONIGHT AS THE FRONT MOVES SLOWLY INTO THE REGION...AS
WELL AS ON SUNDAY AS THE BOUNDARY SAGS SOUTH AND EVENTUALLY
SETTLES SOUTH OF THE AREA SUNDAY EVENING. THE WARM/MOIST AIR
MASS...COMBINED WITH OUR LOCATION ALONG THE SOUTHERN PERIPHERY OF
FASTER WESTERLY FLOW ALOFT...WILL SET THE STAGE FOR THE POTENTIAL
FOR SEVERE THUNDERSTORMS MAINLY THIS AFTERNOON/EVENING...AND AGAIN
SUNDAY AFTERNOON. THE ENTIRE CWA IS IN SPC DAY 1 SLIGHT RISK...AND
A DAY 2 SLIGHT RISK MAINLY ACROSS THE SOUTHERN HALF. DAMAGING
WINDS WILL BE THE PRIMARY SEVERE HAZARD...THOUGH LOCALLY BACKED
WINDS ALONG OUTFLOW BOUNDARIES WOULD PRESENT A LOW TORNADO RISK AS
WELL. HIGH PWAT AIRMASS WILL CONTINUE TO PRODUCE TORRENTIAL
RAINFALL AND POTENTIAL FLOODING WITH STORMS AS WELL.
RATZER
&&
.LONG TERM...
415 AM CDT
SUNDAY NIGHT THROUGH FRIDAY...
FRONT SLIPS SOUTH OF AREA SUNDAY NIGHT WITH THUNDERSTORM THREAT
ENDING FROM NORTH TO SOUTH DURING THE EVENING ACROSS THE SOUTHEAST
HALF OF THE FORECAST AREA. WEAK HIGH PRESSURE SPREADS ACROSS CENTRAL
IL AND IN BEHIND THE FRONT LATER SUNDAY NIGHT.
FAST WEST-NORTHWEST FLOW ALOFT CONTINUES HOWEVER...WITH A SHORT WAVE
PROGGED TO DIG ACROSS THE WESTERN LAKES AREA MONDAY NIGHT INTO
TUESDAY MORNING...WITH THE PASSAGE OF ANOTHER WEAKER COLD FRONT.
WEAK RETURN FLOW SETS UP MONDAY NIGHT...WITH GUIDANCE SHOWING QUITE
A BIT OF SPREAD IN TIMING AND COVERAGE OF PRECIP INTO TUESDAY. HAVE
MAINTAINED SLIGHT CHANCE POPS DURING THE DAY TUESDAY FROM PREVIOUS
FORECAST FOR NOW WITH HOPEFULLY BETTER MODEL AGREEMENT IN THE
DETAILS AS THE PERIOD DRAWS NEARER.
SURFACE HIGH PRESSURE ONCE AGAIN BUILDS INTO THE AREA TUESDAY NIGHT
AND WEDNESDAY...AS UPPER RIDGE BEGINS TO REBUILD ACROSS THE CENTRAL
CONUS. THIS LOOKS TO PROVIDE A DRY MID-WEEK PERIOD WITH
NEAR/SLIGHTLY BELOW NORMAL TEMPS GENERALLY IN THE LOW 80S. MEDIUM
RANGE GUIDANCE ARE THEN IN DECENT AGREEMENT IN BRINGING A SHORT WAVE
THROUGH THE RIDGE AND ACROSS THE MIDWEST THURSDAY...WITH RETURN FLOW
AND THE NEXT CHANCE OF SHOWER/THUNDERSTORMS DEVELOPING IN ADVANCE AS
THE SURFACE HIGH MOVES OFF TO THE EAST.
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* NE WINDS ARND 15 KT WITH OCNL GUSTS TO 20 KT EXPECTED FOR THE
NEXT HOUR OR SO. WINDS THEN SLOWLY VEER BACK TO SW THROUGH THE
EARLY AFTN.
* GUSTY SW WINDS WITH GUSTS ARND 20 KT THIS AFTN.
* TSRA EXPECTED THIS AFTN AND EVENING WITH SHRA OVERNIGHT INTO
SUNDAY MORNING. STRONG TO SEVERE STORMS ARE PROBABLE THIS AFTN.
JEE
//DISCUSSION...UPDATED 16Z...
THE GUST FRONT IS STILL GOING STRONG AND WE ARE NOW FOCUSING ON TS
DEVELOPMENT ALONG IT AND OTHER BOUNDARIES ACROSS THE REGION THIS
AFTN. THINKING THE NE WINDS BEHIND THE GUST FRONT WILL SLOWLY VEER
BACK TO SW INTO THIS AFTN. AT THE SAME TIME INSTABILITY IS
INCREASING ACROSS THE REGION AND EXPECTING STORMS TO FIRE ALONG
THE AFOREMENTIONED BOUNDARIES. EXACT TIMING...LOCATION...AND
TS COVERAGE ARE STILL VERY FUZZY BECAUSE NO PIECE OF GUIDANCE IS
ACCURATELY PORTRAYING WHAT IS HAPPENING NOW. STRONG TO SEVERE
STORMS ARE PROBABLE THIS AFTN.
PREVIOUS DISCUSSION...12Z...
A MESSY FORECAST SITUATION TODAY WITH LOTS OF POTENTIAL PITFALLS.
THE GENERAL PATTERN OF SSWLY-SWLY FLOW IN A VERY WARM/MOIST/
UNSTABLE AIRMASS. DEEPER LAYER MIXING TODAY SHOULD ALLOW STRONG
WINDS TO REACH THE SFC...WITH PREVAILING GUSTS OF 15-20KT.
HOWEVER...IT IS THE FINER SCALE DETAILS THAT HAVE THE POTENTIAL TO
BRING QUICK CHANGES. TWO WELL DEFINED OUTFLOW BOUNDARIES ARE
APPROACHING THE REGION...ONE MOVING EWD THROUGH ERN IOWA AND
ANOTHER DROPPING SEWD THROUGH SRN WISCONSIN. THE OUTFLOW BOUNDARY
DROPPING OUT OF WISCONSIN WILL BE THE INITIAL CONCERN. TIMING THE
BOUNDARY FROM THE LATEST RADAR IMAGERY SUGGESTS THAT IT COULD MOVE
THROUGH RFD AT ARND 13Z AND THR CHICAGO AREA ARND 14Z...SHOULD IT
HOLD TOGETHER. GIVEN THAT UNCERTAINTY...HAVE NOT TRIED TO TIME IT
IN THE LATEST TAF ISSUANCE...BUT THERE IS THE POTENTIAL FOR AN
ABRUPT WIND SHIFT TO NWLY WITH GUSTS TO 30KT.
THERE ALSO CONTINUES TO BE OCNL SCT SHRA/TSRA DEVELOPMENT IN THE
WARM ADVECTION ZONE AHEAD OF THE APPROACHING COLD FRONT. THERE
WILL BE THE POTENTIAL FOR ISOLD ACTIVITY THROUGH THE DAY TODAY
GIVEN THE UNSTABLE ENVIRONMENT. THE ADDITION OF MULTIPLE OUTFLOW
BOUNDARIES LEFT FROM YESTERDAYS ACTIVITY OVER THE REGION AS WELL
AS NEW BOUNDARIES MOVING INTO THE REGION WILL KEEP THE POTENTIAL
FOR ADDITIONAL TSRA TODAY...THOUGH CONFIDENCE IN TIMING...COVERAGE
AND LOCATION IS HIGHLY UNCERTAIN AND MUCH TOO LOW TO TRY AND PIN
DOWN IN THE TAFS AT THIS TIME.
THERE IS A LITTLE BETTER CONFIDENCE IN MORE WIDESPREAD...ORGANIZED
SHRA AND TSRA TONIGHT THIS EVENING AND TONIGHT WITH THE FRONTAL
PASSAGE. WHILE THERE IS STILL SOME TIMING DIFFERENCES AMONG THE
MODEL GUIDANCE AS TO THE EXACT TIMING OF THE FRONT...THE MOST
FAVORABLE TIME FOR MORE ORGANIZED ACTIVITY WILL BE THROUGH THE
EVENING HOURS.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM-LOW CONFIDENCE IN HOW LONG NE GUSTS WILL LAST AND HOW
LONG IT WILL TAKE TO GET BACK TO GUSTY SW WINDS.
* MEDIUM CONFIDENCE IN TSRA TIMING...OCCURRENCE AND COVERAGE THIS
AFTN.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR. WX NIL.
MONDAY...VFR. WX NIL.
TUESDAY...SLIGHT CHANCE TSRA IN THE AFTERNOON.
WEDNESDAY...VFR. WX NIL.
THURSDAY...CHANCE TSRA.
FRIDAY...VFR/WX NIL EARLY. CHANCE TSRA OVERNIGHT.
KREIN
&&
.MARINE...
350 AM CDT
HIGH DEW POINT AIR MAY CONTINUE TO PRODUCE SOME FOG OVER THE OPEN
WATERS OF THE LAKE INTO EARLY SATURDAY MORNING. OTHERWISE...
SOUTH TO SOUTHWEST FLOW OVER THE LAKE SHOULD INCREASE TO ARND
15-25KT THIS AFTERNOON AND TONIGHT AS A COLD FRONT ASSOCIATED WITH
LOW PRESSURE MOVING ACROSS THE CANADIAN PRAIRIES TO HUDSON BAY.
THE FRONT SHOULD PUSH ACROSS THE LAKE LATE SATURDAY NIGHT INTO
SUNDAY MORNING. WEAK HIGH PRESSURE BUILDING IN BEHIND THE FRONT
WILL BEING DIMINISHING WLY FLOW TO THE LAKE...BUT ANOTHER COLD
FRONT DROPPING THROUGH THE UPPER MISSISSIPPI VALLEY MONDAY WILL
BRING ANOTHER ROUND OF INCREASING SWLY WINDS INTO MONDAY EVENING
BEFORE THE COLD FRONT PUSHES ACROSS THE LAKE LATE MONDAY NIGHT
INTO EARLY TUESDAY MORNING. A LARGE AREA OF WEAK HIGH PRESSURE IS
EXPECTED TO SPREAD ACROSS THE GREAT LAKES REGION BY TUESDAY NIGHT.
THE HIGH PRESSURE SHOULD REMAIN NEARLY STATIONARY OVER THE GREAT
LAKES REGION THROUGH MUCH OF NEXT WEEK...BRINGING AN EXTENDED
PERIOD OF LIGHT AND VARIABLE WINDS.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 UNTIL 8 PM SATURDAY.
IN...HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 8 PM
SATURDAY.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
1051 AM CDT SAT JUL 18 2015
.UPDATE...
ISSUED AT 1051 AM CDT SAT JUL 18 2015
MCS THAT DEVELOPED OVER SOUTHEAST NEBRASKA/NORTHWEST MISSOURI
EARLIER THIS MORNING CONTINUES TO TRACK EASTWARD AND IS NOW
APPROACHING THE MISSISSIPPI RIVER. IR SATELLITE HAS SHOWN WARMING
CLOUD TOPS WHILE 15-MINUTE LIGHTNING DATA HAS BEEN CONSISTENTLY
DECREASING OVER THE PAST COUPLE OF HOURS. DESPITE THE DISTINCT
DIURNAL WEAKENING TREND...LIGHT RAIN IS SPILLING INTO WEST-CENTRAL
ILLINOIS. MOST MODELS ARE NOT HANDLING THE CURRENT SITUATION
PARTICULARLY WELL...WITH THE 12Z NAM SHOWING THE SYSTEM COMPLETELY
DISSIPATING BEFORE IT REACHES CENTRAL ILLINOIS. MEANWHILE...THE
LATEST HRRR TAKES THE DIMINISHING PRECIP AREA INTO THE HEART OF
THE KILX CWA EARLY THIS AFTERNOON...WITH WIDELY SCATTERED
THUNDERSTORMS DEVELOPING AHEAD OF THE SYSTEM ACROSS EAST-CENTRAL
AND SOUTHEAST ILLINOIS. THINK THIS MAY BE A LITTLE TOO
AGGRESSIVE...SO HAVE FOLLOWED THE RAPID REFRESH MOST CLOSELY FOR
THE SHORT-TERM FORECAST. AS A RESULT...HAVE INCREASED POPS ACROSS
THE W/SW CWA GENERALLY WEST OF THE I-55 CORRIDOR LATE THIS MORNING
INTO THE EARLY AFTERNOON AS THE SYSTEM CROSSES THE MISSISSIPPI
RIVER. THINK IT WILL GRADUALLY FIZZLE...LEAVING BEHIND A MID/HIGH
OVERCAST THROUGH MID-AFTERNOON. FURTHER E/SE...THINK ISOLATED
THUNDERSTORMS WILL DEVELOP ALONG/E OF I-57 THIS AFTERNOON AS
OUTFLOW BOUNDARY INTERACTS WITH VERY UNSTABLE AIRMASS. MAIN STORY
TODAY WILL BE THE HEAT AND HUMIDITY. DESPITE CLOUD COVER FROM MCS
TEMPORARILY HALTING THE TEMP RISE LATE THIS MORNING INTO THE EARLY
AFTERNOON ACROSS THE WESTERN HALF OF THE AREA...A RETURN TO
PARTIAL SUNSHINE LATER IN THE DAY WILL RESULT IN HIGH TEMPS IN THE
LOWER TO MIDDLE 90S ACROSS THE BOARD. HEAT INDEX VALUES WILL
EXCEED ADVISORY CRITERIA...RANGING FROM 105 TO 110.
&&
.SHORT TERM...(TODAY)
ISSUED AT 332 AM CDT SAT JUL 18 2015
LATEST SURFACE ANALYSIS INDICATING A LARGE POOL OF MID TO UPPER 70
DEGREE DEW POINTS SITUATED OVER MOST OF CENTRAL IL WEST THROUGH
EASTERN IOWA. LARGE COMPLEX OF STORMS OVER MINNESOTA AND NORTHERN
IOWA INTO WESTERN WISCONSIN WILL TRACK EAST WITH MOST OF THE HIGH
RESOLUTION MODELS SUGGESTING A REMNANT OUTFLOW BOUNDARY WILL TRACK
EAST AND SOUTHEAST INTO NORTHERN IL BY THIS AFTERNOON AND EVENING.
MEANWHILE...A WEAK SHORTWAVE OVER EASTERN KS HAS HELPED TO PRODUCE
SOME SCATTERED CONVECTION OVER FAR NORTHWEST MISSOURI WITH THE
LATEST HRRR MODEL BRINGING SOME OF THAT PRECIP INTO OUR AREA THIS
AFTERNOON. NOT VERY CONFIDENT ON HOW THE HRRR MODEL HAS BEEN
HANDLING THE PRECIP/CONVECTIVE TRENDS OVER THE PAST SEVERAL DAYS,
ESPECIALLY AFTER ABOUT 6 TO 8 HOURS INTO THE FORECAST WHERE IT IS
WAY OVERBLOWN WITH RESPECT TO CONVECTIVE COVERAGE/INTENSITY. NOT
SURE IF THAT IS A BY-PRODUCT OF THE ADDED EVAPO-TRANSPIRATION OVER
THE MIDWEST...BUT IT HAS HAD A POOR TRACK RECORD FOR A FEW DAYS NOW
AND AM HESITANT TO TAKE ITS SOLUTION AND RUN WITH IT FOR LATER
TODAY.
WE WILL ADD SLIGHT CHANCES ACROSS THE SOUTHEAST THIS AFTERNOON AS
THE COMBINATION OF THE WEAK UPPER LEVEL WAVE TRACKING ACROSS THE
AREA THIS AFTERNOON COMBINED WITH PEAK HEATING AND MIXED LAYER CAPES
IN THE 2500-3000 J/G RANGE MAY BE ENOUGH TO PRODUCE ISOLATED STORMS.
FURTHER NORTH...CONVECTION THAT FIRED OVER NORTHEAST IL AND FINALLY
DISSPATED A FEW HOURS AGO LOOKS TO HAVE PUSHED A WEAK BOUNDARY TO
OUR FAR NORTHEAST COUNTIES...WHICH MAY BE ENOUGH TO PRODUCE AN
ISOLATED STORM THIS AFTERNOON. FOR NOW...WILL HOLD OFF MENTIONING
ANYTHING ACROSS OUR NORTHEAST BUT WE MAY NEED TO ADD LATER THIS
MORNING IF WE SEE SOME RATHER ROBUST CUMULUS DEVELOP ACROSS THE
AREA. FORECAST SOUNDINGS SHOWING AFTERNOON TEMPERATURES SHOULD WARM
SEVERAL DEGREES FROM WHAT WE SAW YESTERDAY AFTERNOOON...MEANING
LOW TO MID 90S FOR HIGHS AND HEAT INDEX VALUES OF 103-109 DEGREES.
WILL CONTINUE WITH THE HEAT ADVISORY THRU EARLY THIS EVENING.
THE COMPLEX OF STORMS TO OUR NORTHWEST EARLY THIS MORNING WILL TRACK
EAST AND A BIT SOUTHEAST AND AS MENTIONED ABOVE...WILL DRAG A OUTFLOW
BOUNDARY EAST/SE INTO NORTHERN IL LATE THIS AFTERNOON WHICH SHOULD BE
ENOUGH TO PRODUCE SCATTERED STORMS. MOST OF THE DETERMINISTIC MODELS
SUGGEST A SOUTHEAST PUSH TO THE STORM CLUSTER LATE THIS AFTERNOON SO
HAVE INCLUDED SLIGHT CHANCES IN OUR FAR NORTHWEST AFTER 21Z/4PM.
.LONG TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 332 AM CDT SAT JUL 18 2015
NOT MANY CHANGES IN THE MID RANGE OF THE FORECAST. WARM TEMPS
CONTINUE TONIGHT WITH PRECIP AND RESIDUAL CLOUD COVER KEEPING ANY
COOLING TO A MINIMUM AS PREFRONTAL PRECIP EDGES INTO THE REGION FROM
THE NW. FRONT ON TRACK TO PUSH THROUGH THE REGION ON SUNDAY AND SO
FAR, THE MODELS ARE PERSISTENT WITH SOME QPF WELL AHEAD OF THE SFC
BOUNDARY. IF THAT TREND CONTINUES, THE TEMPS IN THE FAR EAST AND
SOUTHEAST MAY REMAIN JUST COOL ENOUGH TO KEEP THE HEAT ADVISORY OUT
OF SUNDAY, ALTHOUGH SOME OF THE GUIDANCE HAS TEMPS IN THE SE RATHER
WARM ALONG AND SOUTH OF INTERSTATE 70. NOT ENTIRELY CONVINCED THAT
THE HEADLINE WILL NOT BE EXTENDED...BUT SO FAR THE HEAT INDICES ARE
REMAINING JUST SUB ADVSY LEVEL.
SUNDAY SHOWERS AND THUNDERSTORMS ALSO POTENTIALLY PROBLEMATIC WITH A
WARM AND HUMID AIRMASS OUT AHEAD OF A BOUNDARY, SPC HAS PUT ALL OF
CENTRAL ILLINOIS IN A SLIGHT RISK FOR DAY 2. OVERNIGHT STORMS
TONIGHT MAY ALSO PROVIDE SOME OUTFLOW BOUNDARIES FOR FOCUS OF MORE
STORMS BEFORE THE ACTUAL FROPA. SHEAR MAINLY UNIDIRECTIONAL AND
LIKELY TO BE MORE OF A WIND AND HAIL THREAT AT THIS TIME. A LOT OF
THE SEVERE THREAT WILL BE DICTATED BY THE PREV NIGHT CONVECTION AND
WHAT IS LEFTOVER SUNDAY MORNING TO LIMIT THE ATMOSPHERE RECHARGING.
SUNDAY NIGHT THE PRECIP SHIFTS TO THE SOUTH WITH THE BOUNDARY
SLOWING A IT LOSES ITS PUSH ALOFT AND GETS HUNG UP IN MORE PARALLEL
FLOW. MONDAY/MONDAY NIGHT WILL SEE THE HIGHER POPS IN THE SOUTH,
ALTHOUGH THERE HAS BEEN SOME WAVERING AS TO WHERE THE BOUNDARY WILL
STALL AS ANOTHER WAVE EJECTS OUT OF THE WEST AND RIPPLES UP THE
BOUNDARY REMAINS. SIMILAR PATTERN TO HOW THIS SUMMER HAS BEEN GOING
SO FAR. ECMWF LINGERING PRECIP INTO TUESDAY AND THE SUPERBLEND
HANGING ONTO THE PRECIP. WILL LIKELY REMOVE SHOULD THE OTHER MODELS
CONTINUE THE DRYING TREND TO TUES/WED AS A WEAK NWRLY FLOW
ESTABLISHES ALOFT. A GENERAL WARMING TREND CONTINUES THROUGH THE
WEEK AS THE NEXT PATTERN SHIFT LINES UP FOR THE END OF THE WEEK WITH
A RETURN OF PRECIP CHANCES MOVES IN THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 600 AM CDT SAT JUL 18 2015
OTHER THAN THE POSSIBILITY FOR A BRIEF PERIOD OF MVFR VSBYS IN
FOG/HZ OVER THE NEXT COUPLE OF HOURS...VFR CONDITIONS ARE EXPECTED
FOR THE REMAINDER OF THIS FORECAST PERIOD. LARGE COMPLEX OF
THUNDERSTORMS TRACKING EAST OVER SOUTHERN WISCONSIN ARE EXPECTED
TO REMAIN NORTH OF THE TAF SITES THIS MORNING. HOWEVER...THE
OUTFLOW BOUNDARY ASSOCIATED WITH THE STORMS WILL PUSH ACROSS
PARTS OF NORTHERN AND NORTHEAST ILLINOIS AND MAY PROVIDE A FOCUS
FOR THUNDERSTORM DEVELOPMENT LATER TODAY. IN ADDITION...A MUCH
SMALLER AREA OF SHOWERS WAS LOCATED OVER WEST CENTRAL MISSOURI
WITH MODELS SUGGESTING A DECREASE IN AREAL COVERAGE AS THE
SHOWERS APPROACH EASTERN MISSOURI.
WE SHOULD SEE AT LEAST SCATTERED CUMULUS DEVELOP BY LATE MORNING
WITH A FEW OF THE FORECAST SOUNDINGS SUGGESTING SCT-BKN CIGS AT
BMI AND CMI. HOWEVER...RAP SOUNDINGS AND TIME HEIGHT CROSS
SECTIONS DO NOT INDICATE THE DEPTH OF THE MOISTURE TO BE THAT
SIGNIFICANT TODAY...SO WILL CARRY SCATTERED CU WITH BASES IN
THE 3000-4000 FOOT RANGE WITH SOME SCT-BKN CIRRUS ABOVE THE
CUMULUS. MAY SEE A COMPLEX OF STORMS DEVELOP LATE TODAY ALONG
THE AFOREMENTIONED REMNANT OUTFLOW BOUNDARY WITH THE STORMS THEN
FORECAST TO SHIFT SOUTH-SOUTHEAST. HOWEVER...THAT SCENARIO THIS
FAR OUT IS A LOW CONFIDENCE FORECAST SO WILL ONLY CARRY A VCTS
ACROSS THE NORTH AFTER 22Z.
SURFACE WINDS TODAY WILL BE FROM THE SOUTH TO SOUTHWEST AT 10 TO
15 KTS WITH AN OCCASIONAL GUST UP TO 20 KTS POSSIBLE DURING THE
AFTERNOON. SOUTH WINDS ARE EXPECTED TONIGHT AT 7 TO 12 KTS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ILZ044>046-054>057-
061>063-066>068-071>073.
HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ILZ027>031-036>038-
040>043-047>053.
&&
$$
UPDATE...BARNES
SHORT TERM...SMITH
LONG TERM...HJS
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
957 AM CDT SAT JUL 18 2015
.UPDATE...
957 AM CDT
OUTFLOW BOUNDARY FROM EARLIER WISCONSIN MCS HAS SAGGED SOUTH INTO
NORTHERN CWA AND IS BEGINNING TO STALL OUT OVER NORTH CENTRAL
ILLINOIS. OVER NORTHEAST ILLINOIS THE LAKE HAS AUGMENTED THE
BOUNDARY AND PROVIDED SOME ADDITIONAL SOUTHWARD ACCELERATION
ADJACENT TO LAKE MICHIGAN. ANTICIPATE THE BOUNDARY WILL STALL OUT
EVEN OVER NORTHEAST ILLINOIS AND PROBABLY RETREAT NORTH DURING THE
DAY AS SUNSHINE ALLOWS FOR STRONG HEATING/MIXING AND A MODEST
SOUTHWEST WIND DEVELOPS. DESPITE THE INITIALLY COOLER AIR NEAR THE
LAKE...STILL FEEL THERE IS A REASONABLY GOOD CHANCE THAT THE
BOUNDARY WILL STALL/RETREAT ENOUGH TO PROVIDE FOR A HOT/HUMID
AFTERNOON WITH HEAT INDICES ABOVE 100 OVER EVEN NORTHEAST ILLINOIS
SO NOT PLANNING TO CHANGE HEAT ADVISORY ANY THIS MORNING. MAY
BROADEN THE RANGE OF HEAT INDICES TO 100 TO 110 AS CLOUDS FROM
IA/MO MCS MAY LIMIT THE HEAT SOME THIS AFTERNOON...MAINLY WESTERN
CWA.
AMPLE SUNSHINE IN ADVANCE OF ANY CLOUDINESS FROM MO/IA CONVECTION
WILL ALLOW FOR RAPID HEATING AND DESTABILIZATION ACROSS THE CWA
THROUGH EARLY AFTERNOON...BUT PARTICULARLY TO THE SOUTH OF THE WI
MCS REMNANT OUTFLOW BOUNDARY. DVN/ILX MORNING SOUNDINGS BOTH SHOW
MODERATELY STEEP LOW/MID LEVEL LAPSE RATES AND AS TEMPS/DEWPOINTS
RISE TOWARD PROJECTED HIGHS REGION SHOULD BE LEFT UNCAPPED BY
EARLY AFTERNOON...WITH MODIFIED ILX SOUNDING SUPPORTING SHOWING
MLCAPE VALUES NEARING 4000 J/KG BY EARLY THIS AFTERNOON WITH SFC
PARCEL OF 90/77...WHICH APPEARS EASILY ATTAINABLE IN THE WARM
SECTOR TODAY.
MORNING UPPER AIR ANALYSIS AND ACARS DATA SHOW 35-45KT FLOW
AROUND 6KM FROM IA INTO NORTHERN ILLINOIS WHICH WILL RESULT IN
0-6KM SHEAR VALUES OF AT LEAST AROUND 30KT...WHICH COMBINED WITH
SUCH STRONG INSTABILITY WOULD SUPPORT ORGANIZED CONVECTION AND
PERHAPS EVEN A SUPERCELL THREAT...ESPECIALLY IF ANY CELLS WERE TO
RIDE OUTFLOW BOUNDARY. PRIMARY SEVERE THREAT WOULD BE LARGE HAIL
AND DAMAGING WINDS...THOUGH CANNOT COMPLETELY RULE OUT A TORNADO
THREAT WITH ANY CELLS INTERACTING WITH BOUNDARIES GIVEN THE STRONG
LOW LEVEL CAPE AND LOW LCL HEIGHTS. OBVIOUSLY STILL SITTING IN A
VERY MOIST ENVIRONMENT SO HEAVY RAINFALL AND LOCALIZED FLASH
FLOODING IS ALSO A THREAT.
PLAN TO UPDATE GRIDS SHORTLY TO INTRODUCE POPS FOR THIS AFTERNOON
SPREADING THEM FROM WEST TO EAST. GENERALLY LIKE THE TRENDS IN THE
EXPERIMENTAL HRRR WHICH SHOWS STORMS DEVELOPING IN EAST AND
NORTHEAST OF THE IA/MO DECAYING MCS AND OUTFLOW BOUNDARY. WITH
MODEL GUIDANCE ALL OVER THE PLACE AND CAMS NOT HANDLING ONGOING
SITUATION WELL CONFIDENCE IS DIMINISHED...BUT CERTAINLY
OBSERVATIONAL TRENDS SUPPORT THE ABOVE FORECAST SCENARIO AND PLAN
TO INCREASE POPS INTO THE HIGH END CHANCE RANGE FOR NOW.
DESPITE THE HIGHER STORM CHANCES TODAY...PRIOR TO ANY STORMS HEAT
INDICES ARE LIKELY TO REACH 100 TO POTENTIALLY 110 DEGREES TODAY
SO LEAVING THE HEAT HEADLINES UNCHANGED.
GRIDS ARE GOING TO TAKE A LOT OF SURGERY TO REFLECT THE ABOVE
THINKING SINCE THERE IS NO REAL GUIDANCE REFLECTING CURRENT TRENDS
OR ABOVE THINKING...BUT FORECAST UPDATES ARE FORTHCOMING.
IZZI
&&
.SHORT TERM...
408 AM CDT
TODAY THROUGH SUNDAY...
HEAT...HUMIDITY AND TIMING/COVERAGE OF THUNDERSTORMS ARE THE MAIN
FORECAST CONCERNS IN THE SHORT TERM PERIOD.
A VERY WARM AND HUMID AIR MASS REMAINS IN PLACE ACROSS THE
FORECAST AREA EARLY THIS MORNING...WITH LOW LEVEL THERMAL RIDGE TO
BUILD INTO THE REGION TODAY ON PERSISTENT SOUTH-SOUTHWEST LOW
LEVEL FLOW. LOW LEVEL THERMAL PROGS FROM VARIOUS MODELS SUPPORT
AFTERNOON TEMPS IN THE LOW-MID 90S ACROSS THE CWA...WITH DEW
POINTS IN THE MID-UPPER 70S EXPECTED TO YIELD PEAK AFTERNOON HEAT
INDICES IN THE 105-110 DEGREE RANGE. A HEAT ADVISORY REMAINS IN
EFFECT FOR THE ENTIRE CWA WITH NO CHANGES AT THIS TIME.
SOME COMPLICATIONS EXIST WITH THE FORECAST HOWEVER...PRIMARILY
WITH THE POTENTIAL FOR OUTFLOW FROM MCS CURRENTLY TRACKING ACROSS
WISCONSIN AND ALSO WITH THE POTENTIAL FOR THUNDERSTORMS ACROSS
PORTIONS OF THE CWA TODAY. CONVECTION-ALLOWING GUIDANCE HAS NOT
BEEN HANDLING THE UPPER MIDWEST MCS VERY WELL OVERNIGHT...THOUGH
SOME MODELS PARTICULARLY THE 00Z ARW/NMM-EAST RUNS DO DEPICT A
SOMEWHAT SIMILAR BOWING MCS ACROSS WI...TURNING IT SOUTHEAST A BIT
ACROSS LAKE MICHIGAN THIS MORNING. THIS SEEMS FAIRLY
REASONABLE...AS SPC MESOANALYSIS DEPICTS AN MUCAPE AXIS OF
2000-4000 J/KG FROM THE UPPER MISSISSIPPI VALLEY SOUTHEAST INTO
NORTHERN IL AT 08Z...REASONABLY STEEP MID-LEVEL LAPSE RATES...AND
A 850-300 MB THICKNESS GRADIENT WHICH WOULD FAVOR A SOUTHEASTWARD
PROPAGATION. THE QUESTION IS HOW FAR SOUTH CONVECTION DEVELOPS
ALONG THE IL/WI BORDER AREA THIS MORNING...AND HOW MUCH OF AN
EFFECT OUTFLOW BOUNDARIES NOTED ACROSS EASTERN IA AND LIKELY FROM
SOUTHERN WI WILL HAVE ON OUR TEMP AND DEW POINT TRENDS TODAY.
CURRENT THINKING IS THAT SCATTERED STORMS ALONG SOUTHERN PERIPHERY
OF THE MCS MAY SCRAPE ALONG THE IL/WI BORDER AREA EARLY THIS
AM...MOVING EAST OF THE THE AREA BY MID-LATE MORNING WHICH SHOULD
ALLOW DISSIPATION OF HIGH CLOUDS AND RECOVERY OF TEMPS AND DEW
POINTS BACK INTO FORECAST RANGE THIS AFTERNOON.
ADDITIONAL THUNDERSTORMS ARE EXPECTED BY THIS EVENING...AS A COLD
FRONT TRAILING FROM LOW PRESSURE OVER ONTARIO APPROACHES AND
EVENTUALLY PASSES ON SUNDAY. WHILE MOST GUIDANCE DEPICTS A
SCENARIO OF STORMS INITIATING ALONG/AHEAD OF THE FRONT ACROSS
WISCONSIN AND IOWA THIS AFTERNOON AND MOVING INTO THE AREA THIS
EVENING... LINGERING OUTFLOW BOUNDARIES MAY PROVIDE FOCUS FOR
ISOLATED TO SCATTERED STORMS TO DEVELOP OVER PORTIONS OF THE AREA
THIS AFTERNOON. ONE POSSIBLE FOCUS WOULD BE THE OUTFLOW BOUNDARY
FROM THIS MORNINGS MCS...WHICH WILL LIKELY BE SOMEWHERE OVER FAR
NORTHERN IL THIS AFTERNOON. THUS HAVE ADDED SOME CHANCE POPS BY
EARLY THIS AFTERNOON ACROSS NORTHERN IL. THUNDERSTORM CHANCES WILL
CONTINUE TONIGHT AS THE FRONT MOVES SLOWLY INTO THE REGION...AS
WELL AS ON SUNDAY AS THE BOUNDARY SAGS SOUTH AND EVENTUALLY
SETTLES SOUTH OF THE AREA SUNDAY EVENING. THE WARM/MOIST AIR
MASS...COMBINED WITH OUR LOCATION ALONG THE SOUTHERN PERIPHERY OF
FASTER WESTERLY FLOW ALOFT...WILL SET THE STAGE FOR THE POTENTIAL
FOR SEVERE THUNDERSTORMS MAINLY THIS AFTERNOON/EVENING...AND AGAIN
SUNDAY AFTERNOON. THE ENTIRE CWA IS IN SPC DAY 1 SLIGHT RISK...AND
A DAY 2 SLIGHT RISK MAINLY ACROSS THE SOUTHERN HALF. DAMAGING
WINDS WILL BE THE PRIMARY SEVERE HAZARD...THOUGH LOCALLY BACKED
WINDS ALONG OUTFLOW BOUNDARIES WOULD PRESENT A LOW TORNADO RISK AS
WELL. HIGH PWAT AIRMASS WILL CONTINUE TO PRODUCE TORRENTIAL
RAINFALL AND POTENTIAL FLOODING WITH STORMS AS WELL.
RATZER
&&
.LONG TERM...
415 AM CDT
SUNDAY NIGHT THROUGH FRIDAY...
FRONT SLIPS SOUTH OF AREA SUNDAY NIGHT WITH THUNDERSTORM THREAT
ENDING FROM NORTH TO SOUTH DURING THE EVENING ACROSS THE SOUTHEAST
HALF OF THE FORECAST AREA. WEAK HIGH PRESSURE SPREADS ACROSS CENTRAL
IL AND IN BEHIND THE FRONT LATER SUNDAY NIGHT.
FAST WEST-NORTHWEST FLOW ALOFT CONTINUES HOWEVER...WITH A SHORT WAVE
PROGGED TO DIG ACROSS THE WESTERN LAKES AREA MONDAY NIGHT INTO
TUESDAY MORNING...WITH THE PASSAGE OF ANOTHER WEAKER COLD FRONT.
WEAK RETURN FLOW SETS UP MONDAY NIGHT...WITH GUIDANCE SHOWING QUITE
A BIT OF SPREAD IN TIMING AND COVERAGE OF PRECIP INTO TUESDAY. HAVE
MAINTAINED SLIGHT CHANCE POPS DURING THE DAY TUESDAY FROM PREVIOUS
FORECAST FOR NOW WITH HOPEFULLY BETTER MODEL AGREEMENT IN THE
DETAILS AS THE PERIOD DRAWS NEARER.
SURFACE HIGH PRESSURE ONCE AGAIN BUILDS INTO THE AREA TUESDAY NIGHT
AND WEDNESDAY...AS UPPER RIDGE BEGINS TO REBUILD ACROSS THE CENTRAL
CONUS. THIS LOOKS TO PROVIDE A DRY MID-WEEK PERIOD WITH
NEAR/SLIGHTLY BELOW NORMAL TEMPS GENERALLY IN THE LOW 80S. MEDIUM
RANGE GUIDANCE ARE THEN IN DECENT AGREEMENT IN BRINGING A SHORT WAVE
THROUGH THE RIDGE AND ACROSS THE MIDWEST THURSDAY...WITH RETURN FLOW
AND THE NEXT CHANCE OF SHOWER/THUNDERSTORMS DEVELOPING IN ADVANCE AS
THE SURFACE HIGH MOVES OFF TO THE EAST.
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* LAKE BREEZE/GUST FRONT SHIFTS WINDS TO NE WITH A BRIEF PERIOD OF
GUSTS TO 16 KT AT ORD ARND 1430Z. BRIEF PERIOD OF MVFR CIGS
BEHIND THE WIND SHIFT. LOW CONFIDENCE IN A WIND SHIFT AT MDW.
* GUSTY SW WINDS WITH GUSTS ARND 20 KT THIS AFTN.
* TSRA IS PSBL THIS AFTN AND AGAIN THIS EVENING WITH SHRA
OVERNIGHT INTO SUNDAY MORNING.
JEE
//DISCUSSION...UPDATED 12Z...
A GUST FRONT FROM THE CONVECTION OVER WI IS SHIFTING SOUTH THROUGH
NORTHERN IL. IT APPEARED TO BE WEAKENING UNTIL A LAKE BREEZE
COMPONENT MERGED WITH IT AND BROUGHT IT BACK TO LIFE. WINDS AT PWK
BRIEFLY TURNED TO 03009G16KT SO THINKING ORD WILL SEE A BRIEF
PERIOD OF GUSTY NE WINDS. THINKING THE BOUNDARY SHOULD WEAKEN
BEFORE IT REACHES MDW AND GYY. THIS BOUNDARY WILL LIKELY BE THE
FOCUS FOR TSRA THIS AFTN SO PUT A TEMPO IN ALL OF THE TAFS FOR
TSRA EARLY THIS AFTN. HAVE MEDIUM CONFIDENCE IN
TIMING...COVERAGE...AND OCCURRENCE AND PLAN TO GET MORE SPECIFIC
IN TIME IN FUTURE UPDATES AS CONDITIONS IMPROVE AND CONFIDENCE
INCREASES.
PREVIOUS DISCUSSION...12Z...
A MESSY FORECAST SITUATION TODAY WITH LOTS OF POTENTIAL PITFALLS.
THE GENERAL PATTERN OF SSWLY-SWLY FLOW IN A VERY WARM/MOIST/
UNSTABLE AIRMASS. DEEPER LAYER MIXING TODAY SHOULD ALLOW STRONG
WINDS TO REACH THE SFC...WITH PREVAILING GUSTS OF 15-20KT.
HOWEVER...IT IS THE FINER SCALE DETAILS THAT HAVE THE POTENTIAL TO
BRING QUICK CHANGES. TWO WELL DEFINED OUTFLOW BOUNDARIES ARE
APPROACHING THE REGION...ONE MOVING EWD THROUGH ERN IOWA AND
ANOTHER DROPPING SEWD THROUGH SRN WISCONSIN. THE OUTFLOW BOUNDARY
DROPPING OUT OF WISCONSIN WILL BE THE INITIAL CONCERN. TIMING THE
BOUNDARY FROM THE LATEST RADAR IMAGERY SUGGESTS THAT IT COULD MOVE
THROUGH RFD AT ARND 13Z AND THR CHICAGO AREA ARND 14Z...SHOULD IT
HOLD TOGETHER. GIVEN THAT UNCERTAINTY...HAVE NOT TRIED TO TIME IT
IN THE LATEST TAF ISSUANCE...BUT THERE IS THE POTENTIAL FOR AN
ABRUPT WIND SHIFT TO NWLY WITH GUSTS TO 30KT.
THERE ALSO CONTINUES TO BE OCNL SCT SHRA/TSRA DEVELOPMENT IN THE
WARM ADVECTION ZONE AHEAD OF THE APPROACHING COLD FRONT. THERE
WILL BE THE POTENTIAL FOR ISOLD ACTIVITY THROUGH THE DAY TODAY
GIVEN THE UNSTABLE ENVIRONMENT. THE ADDITION OF MULTIPLE OUTFLOW
BOUNDARIES LEFT FROM YESTERDAYS ACTIVITY OVER THE REGION AS WELL
AS NEW BOUNDARIES MOVING INTO THE REGION WILL KEEP THE POTENTIAL
FOR ADDITIONAL TSRA TODAY...THOUGH CONFIDENCE IN TIMING...COVERAGE
AND LOCATION IS HIGHLY UNCERTAIN AND MUCH TOO LOW TO TRY AND PIN
DOWN IN THE TAFS AT THIS TIME.
THERE IS A LITTLE BETTER CONFIDENCE IN MORE WIDESPREAD...ORGANIZED
SHRA AND TSRA TONIGHT THIS EVENING AND TONIGHT WITH THE FRONTAL
PASSAGE. WHILE THERE IS STILL SOME TIMING DIFFERENCES AMONG THE
MODEL GUIDANCE AS TO THE EXACT TIMING OF THE FRONT...THE MOST
FAVORABLE TIME FOR MORE ORGANIZED ACTIVITY WILL BE THROUGH THE
EVENING HOURS.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM-HIGH CONFIDENCE IN WINDS FOLLOWING LAKE BREEZE/GUST FRONT
AT ORD...LOW CONFIDENCE IN HOW LONG NE GUSTS WILL LAST AND HOW
LONG IT WILL TAKE TO GET BACK TO GUSTY SW WINDS. LOW CONFIDENCE
IN A WIND SHIFT AT MDW.
* MEDIUM CONFIDENCE IN TSRA TIMING...OCCURRENCE AND COVERAGE THIS
AFTN.
* MEDIUM CONFIDENCE ON TS DETAILS ASSOCIATED WITH THE COLD FRONT
MOVING THROUGH THE REGION THIS EVENING.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR. WX NIL.
MONDAY...VFR. WX NIL.
TUESDAY...SLIGHT CHANCE TSRA IN THE AFTERNOON.
WEDNESDAY...VFR. WX NIL.
THURSDAY...CHANCE TSRA.
FRIDAY...VFR/WX NIL EARLY. CHANCE TSRA OVERNIGHT.
KREIN
&&
.MARINE...
350 AM CDT
HIGH DEW POINT AIR MAY CONTINUE TO PRODUCE SOME FOG OVER THE OPEN
WATERS OF THE LAKE INTO EARLY SATURDAY MORNING. OTHERWISE...
SOUTH TO SOUTHWEST FLOW OVER THE LAKE SHOULD INCREASE TO ARND
15-25KT THIS AFTERNOON AND TONIGHT AS A COLD FRONT ASSOCIATED WITH
LOW PRESSURE MOVING ACROSS THE CANADIAN PRAIRIES TO HUDSON BAY.
THE FRONT SHOULD PUSH ACROSS THE LAKE LATE SATURDAY NIGHT INTO
SUNDAY MORNING. WEAK HIGH PRESSURE BUILDING IN BEHIND THE FRONT
WILL BEING DIMINISHING WLY FLOW TO THE LAKE...BUT ANOTHER COLD
FRONT DROPPING THROUGH THE UPPER MISSISSIPPI VALLEY MONDAY WILL
BRING ANOTHER ROUND OF INCREASING SWLY WINDS INTO MONDAY EVENING
BEFORE THE COLD FRONT PUSHES ACROSS THE LAKE LATE MONDAY NIGHT
INTO EARLY TUESDAY MORNING. A LARGE AREA OF WEAK HIGH PRESSURE IS
EXPECTED TO SPREAD ACROSS THE GREAT LAKES REGION BY TUESDAY NIGHT.
THE HIGH PRESSURE SHOULD REMAIN NEARLY STATIONARY OVER THE GREAT
LAKES REGION THROUGH MUCH OF NEXT WEEK...BRINGING AN EXTENDED
PERIOD OF LIGHT AND VARIABLE WINDS.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ019-ILZ021-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL
8 PM SATURDAY.
HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ020-ILZ022 UNTIL 8 PM SATURDAY.
IN...HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 8 PM
SATURDAY.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
607 AM CDT SAT JUL 18 2015
.SHORT TERM...(TODAY)
ISSUED AT 332 AM CDT SAT JUL 18 2015
LATEST SURFACE ANALYSIS INDICATING A LARGE POOL OF MID TO UPPER 70
DEGREE DEW POINTS SITUATED OVER MOST OF CENTRAL IL WEST THROUGH
EASTERN IOWA. LARGE COMPLEX OF STORMS OVER MINNESOTA AND NORTHERN
IOWA INTO WESTERN WISCONSIN WILL TRACK EAST WITH MOST OF THE HIGH
RESOLUTION MODELS SUGGESTING A REMNANT OUTFLOW BOUNDARY WILL TRACK
EAST AND SOUTHEAST INTO NORTHERN IL BY THIS AFTERNOON AND EVENING.
MEANWHILE...A WEAK SHORTWAVE OVER EASTERN KS HAS HELPED TO PRODUCE
SOME SCATTERED CONVECTION OVER FAR NORTHWEST MISSOURI WITH THE
LATEST HRRR MODEL BRINGING SOME OF THAT PRECIP INTO OUR AREA THIS
AFTERNOON. NOT VERY CONFIDENT ON HOW THE HRRR MODEL HAS BEEN
HANDLING THE PRECIP/CONVECTIVE TRENDS OVER THE PAST SEVERAL DAYS,
ESPECIALLY AFTER ABOUT 6 TO 8 HOURS INTO THE FORECAST WHERE IT IS
WAY OVERBLOWN WITH RESPECT TO CONVECTIVE COVERAGE/INTENSITY. NOT
SURE IF THAT IS A BY-PRODUCT OF THE ADDED EVAPO-TRANSPIRATION OVER
THE MIDWEST...BUT IT HAS HAD A POOR TRACK RECORD FOR A FEW DAYS NOW
AND AM HESITANT TO TAKE ITS SOLUTION AND RUN WITH IT FOR LATER
TODAY.
WE WILL ADD SLIGHT CHANCES ACROSS THE SOUTHEAST THIS AFTERNOON AS
THE COMBINATION OF THE WEAK UPPER LEVEL WAVE TRACKING ACROSS THE
AREA THIS AFTERNOON COMBINED WITH PEAK HEATING AND MIXED LAYER CAPES
IN THE 2500-3000 J/G RANGE MAY BE ENOUGH TO PRODUCE ISOLATED STORMS.
FURTHER NORTH...CONVECTION THAT FIRED OVER NORTHEAST IL AND FINALLY
DISSPATED A FEW HOURS AGO LOOKS TO HAVE PUSHED A WEAK BOUNDARY TO
OUR FAR NORTHEAST COUNTIES...WHICH MAY BE ENOUGH TO PRODUCE AN
ISOLATED STORM THIS AFTERNOON. FOR NOW...WILL HOLD OFF MENTIONING
ANYTHING ACROSS OUR NORTHEAST BUT WE MAY NEED TO ADD LATER THIS
MORNING IF WE SEE SOME RATHER ROBUST CUMULUS DEVELOP ACROSS THE
AREA. FORECAST SOUNDINGS SHOWING AFTERNOON TEMPERATURES SHOULD WARM
SEVERAL DEGREES FROM WHAT WE SAW YESTERDAY AFTERNOOON...MEANING
LOW TO MID 90S FOR HIGHS AND HEAT INDEX VALUES OF 103-109 DEGREES.
WILL CONTINUE WITH THE HEAT ADVISORY THRU EARLY THIS EVENING.
THE COMPLEX OF STORMS TO OUR NORTHWEST EARLY THIS MORNING WILL TRACK
EAST AND A BIT SOUTHEAST AND AS MENTIONED ABOVE...WILL DRAG A OUTFLOW
BOUNDARY EAST/SE INTO NORTHERN IL LATE THIS AFTERNOON WHICH SHOULD BE
ENOUGH TO PRODUCE SCATTERED STORMS. MOST OF THE DETERMINISTIC MODELS
SUGGEST A SOUTHEAST PUSH TO THE STORM CLUSTER LATE THIS AFTERNOON SO
HAVE INCLUDED SLIGHT CHANCES IN OUR FAR NORTHWEST AFTER 21Z/4PM.
.LONG TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 332 AM CDT SAT JUL 18 2015
NOT MANY CHANGES IN THE MID RANGE OF THE FORECAST. WARM TEMPS
CONTINUE TONIGHT WITH PRECIP AND RESIDUAL CLOUD COVER KEEPING ANY
COOLING TO A MINIMUM AS PREFRONTAL PRECIP EDGES INTO THE REGION FROM
THE NW. FRONT ON TRACK TO PUSH THROUGH THE REGION ON SUNDAY AND SO
FAR, THE MODELS ARE PERSISTENT WITH SOME QPF WELL AHEAD OF THE SFC
BOUNDARY. IF THAT TREND CONTINUES, THE TEMPS IN THE FAR EAST AND
SOUTHEAST MAY REMAIN JUST COOL ENOUGH TO KEEP THE HEAT ADVISORY OUT
OF SUNDAY, ALTHOUGH SOME OF THE GUIDANCE HAS TEMPS IN THE SE RATHER
WARM ALONG AND SOUTH OF INTERSTATE 70. NOT ENTIRELY CONVINCED THAT
THE HEADLINE WILL NOT BE EXTENDED...BUT SO FAR THE HEAT INDICES ARE
REMAINING JUST SUB ADVSY LEVEL.
SUNDAY SHOWERS AND THUNDERSTORMS ALSO POTENTIALLY PROBLEMATIC WITH A
WARM AND HUMID AIRMASS OUT AHEAD OF A BOUNDARY, SPC HAS PUT ALL OF
CENTRAL ILLINOIS IN A SLIGHT RISK FOR DAY 2. OVERNIGHT STORMS
TONIGHT MAY ALSO PROVIDE SOME OUTFLOW BOUNDARIES FOR FOCUS OF MORE
STORMS BEFORE THE ACTUAL FROPA. SHEAR MAINLY UNIDIRECTIONAL AND
LIKELY TO BE MORE OF A WIND AND HAIL THREAT AT THIS TIME. A LOT OF
THE SEVERE THREAT WILL BE DICTATED BY THE PREV NIGHT CONVECTION AND
WHAT IS LEFTOVER SUNDAY MORNING TO LIMIT THE ATMOSPHERE RECHARGING.
SUNDAY NIGHT THE PRECIP SHIFTS TO THE SOUTH WITH THE BOUNDARY
SLOWING A IT LOSES ITS PUSH ALOFT AND GETS HUNG UP IN MORE PARALLEL
FLOW. MONDAY/MONDAY NIGHT WILL SEE THE HIGHER POPS IN THE SOUTH,
ALTHOUGH THERE HAS BEEN SOME WAVERING AS TO WHERE THE BOUNDARY WILL
STALL AS ANOTHER WAVE EJECTS OUT OF THE WEST AND RIPPLES UP THE
BOUNDARY REMAINS. SIMILAR PATTERN TO HOW THIS SUMMER HAS BEEN GOING
SO FAR. ECMWF LINGERING PRECIP INTO TUESDAY AND THE SUPERBLEND
HANGING ONTO THE PRECIP. WILL LIKELY REMOVE SHOULD THE OTHER MODELS
CONTINUE THE DRYING TREND TO TUES/WED AS A WEAK NWRLY FLOW
ESTABLISHES ALOFT. A GENERAL WARMING TREND CONTINUES THROUGH THE
WEEK AS THE NEXT PATTERN SHIFT LINES UP FOR THE END OF THE WEEK WITH
A RETURN OF PRECIP CHANCES MOVES IN THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 600 AM CDT SAT JUL 18 2015
OTHER THAN THE POSSIBILITY FOR A BRIEF PERIOD OF MVFR VSBYS IN
FOG/HZ OVER THE NEXT COUPLE OF HOURS...VFR CONDITIONS ARE EXPECTED
FOR THE REMAINDER OF THIS FORECAST PERIOD. LARGE COMPLEX OF
THUNDERSTORMS TRACKING EAST OVER SOUTHERN WISCONSIN ARE EXPECTED
TO REMAIN NORTH OF THE TAF SITES THIS MORNING. HOWEVER...THE
OUTFLOW BOUNDARY ASSOCIATED WITH THE STORMS WILL PUSH ACROSS
PARTS OF NORTHERN AND NORTHEAST ILLINOIS AND MAY PROVIDE A FOCUS
FOR THUNDERSTORM DEVELOPMENT LATER TODAY. IN ADDITION...A MUCH
SMALLER AREA OF SHOWERS WAS LOCATED OVER WEST CENTRAL MISSOURI
WITH MODELS SUGGESTING A DECREASE IN AREAL COVERAGE AS THE
SHOWERS APPROACH EASTERN MISSOURI.
WE SHOULD SEE AT LEAST SCATTERED CUMULUS DEVELOP BY LATE MORNING
WITH A FEW OF THE FORECAST SOUNDINGS SUGGESTING SCT-BKN CIGS AT
BMI AND CMI. HOWEVER...RAP SOUNDINGS AND TIME HEIGHT CROSS
SECTIONS DO NOT INDICATE THE DEPTH OF THE MOISTURE TO BE THAT
SIGNIFICANT TODAY...SO WILL CARRY SCATTERED CU WITH BASES IN
THE 3000-4000 FOOT RANGE WITH SOME SCT-BKN CIRRUS ABOVE THE
CUMULUS. MAY SEE A COMPLEX OF STORMS DEVELOP LATE TODAY ALONG
THE AFOREMENTIONED REMNANT OUTFLOW BOUNDARY WITH THE STORMS THEN
FORECAST TO SHIFT SOUTH-SOUTHEAST. HOWEVER...THAT SCENARIO THIS
FAR OUT IS A LOW CONFIDENCE FORECAST SO WILL ONLY CARRY A VCTS
ACROSS THE NORTH AFTER 22Z.
SURFACE WINDS TODAY WILL BE FROM THE SOUTH TO SOUTHWEST AT 10 TO
15 KTS WITH AN OCCASIONAL GUST UP TO 20 KTS POSSIBLE DURING THE
AFTERNOON. SOUTH WINDS ARE EXPECTED TONIGHT AT 7 TO 12 KTS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR
ILZ044>046-054>057-061>063-066>068-071>073.
HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ILZ027>031-036>038-
040>043-047>053.
&&
$$
SHORT TERM...SMITH
LONG TERM...HJS
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
333 AM CDT SAT JUL 18 2015
.SHORT TERM...(TODAY)
ISSUED AT 332 AM CDT SAT JUL 18 2015
LATEST SURFACE ANALYSIS INDICATING A LARGE POOL OF MID TO UPPER 70
DEGREE DEW POINTS SITUATED OVER MOST OF CENTRAL IL WEST THROUGH
EASTERN IOWA. LARGE COMPLEX OF STORMS OVER MINNESOTA AND NORTHERN
IOWA INTO WESTERN WISCONSIN WILL TRACK EAST WITH MOST OF THE HIGH
RESOLUTION MODELS SUGGESTING A REMNANT OUTFLOW BOUNDARY WILL TRACK
EAST AND SOUTHEAST INTO NORTHERN IL BY THIS AFTERNOON AND EVENING.
MEANWHILE...A WEAK SHORTWAVE OVER EASTERN KS HAS HELPED TO PRODUCE
SOME SCATTERED CONVECTION OVER FAR NORTHWEST MISSOURI WITH THE
LATEST HRRR MODEL BRINGING SOME OF THAT PRECIP INTO OUR AREA THIS
AFTERNOON. NOT VERY CONFIDENT ON HOW THE HRRR MODEL HAS BEEN
HANDLING THE PRECIP/CONVECTIVE TRENDS OVER THE PAST SEVERAL DAYS,
ESPECIALLY AFTER ABOUT 6 TO 8 HOURS INTO THE FORECAST WHERE IT IS
WAY OVERBLOWN WITH RESPECT TO CONVECTIVE COVERAGE/INTENSITY. NOT
SURE IF THAT IS A BY-PRODUCT OF THE ADDED EVAPO-TRANSPIRATION OVER
THE MIDWEST...BUT IT HAS HAD A POOR TRACK RECORD FOR A FEW DAYS NOW
AND AM HESITANT TO TAKE ITS SOLUTION AND RUN WITH IT FOR LATER
TODAY.
WE WILL ADD SLIGHT CHANCES ACROSS THE SOUTHEAST THIS AFTERNOON AS
THE COMBINATION OF THE WEAK UPPER LEVEL WAVE TRACKING ACROSS THE
AREA THIS AFTERNOON COMBINED WITH PEAK HEATING AND MIXED LAYER CAPES
IN THE 2500-3000 J/G RANGE MAY BE ENOUGH TO PRODUCE ISOLATED STORMS.
FURTHER NORTH...CONVECTION THAT FIRED OVER NORTHEAST IL AND FINALLY
DISSPATED A FEW HOURS AGO LOOKS TO HAVE PUSHED A WEAK BOUNDARY TO
OUR FAR NORTHEAST COUNTIES...WHICH MAY BE ENOUGH TO PRODUCE AN
ISOLATED STORM THIS AFTERNOON. FOR NOW...WILL HOLD OFF MENTIONING
ANYTHING ACROSS OUR NORTHEAST BUT WE MAY NEED TO ADD LATER THIS
MORNING IF WE SEE SOME RATHER ROBUST CUMULUS DEVELOP ACROSS THE
AREA. FORECAST SOUNDINGS SHOWING AFTERNOON TEMPERATURES SHOULD WARM
SEVERAL DEGREES FROM WHAT WE SAW YESTERDAY AFTERNOOON...MEANING
LOW TO MID 90S FOR HIGHS AND HEAT INDEX VALUES OF 103-109 DEGREES.
WILL CONTINUE WITH THE HEAT ADVISORY THRU EARLY THIS EVENING.
THE COMPLEX OF STORMS TO OUR NORTHWEST EARLY THIS MORNING WILL TRACK
EAST AND A BIT SOUTHEAST AND AS MENTIONED ABOVE...WILL DRAG A OUTFLOW
BOUNDARY EAST/SE INTO NORTHERN IL LATE THIS AFTERNOON WHICH SHOULD BE
ENOUGH TO PRODUCE SCATTERED STORMS. MOST OF THE DETERMINISTIC MODELS
SUGGEST A SOUTHEAST PUSH TO THE STORM CLUSTER LATE THIS AFTERNOON SO
HAVE INCLUDED SLIGHT CHANCES IN OUR FAR NORTHWEST AFTER 21Z/4PM.
&&
.LONG TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 332 AM CDT SAT JUL 18 2015
NOT MANY CHANGES IN THE MID RANGE OF THE FORECAST. WARM TEMPS
CONTINUE TONIGHT WITH PRECIP AND RESIDUAL CLOUD COVER KEEPING ANY
COOLING TO A MINIMUM AS PREFRONTAL PRECIP EDGES INTO THE REGION FROM
THE NW. FRONT ON TRACK TO PUSH THROUGH THE REGION ON SUNDAY AND SO
FAR, THE MODELS ARE PERSISTENT WITH SOME QPF WELL AHEAD OF THE SFC
BOUNDARY. IF THAT TREND CONTINUES, THE TEMPS IN THE FAR EAST AND
SOUTHEAST MAY REMAIN JUST COOL ENOUGH TO KEEP THE HEAT ADVISORY OUT
OF SUNDAY, ALTHOUGH SOME OF THE GUIDANCE HAS TEMPS IN THE SE RATHER
WARM ALONG AND SOUTH OF INTERSTATE 70. NOT ENTIRELY CONVINCED THAT
THE HEADLINE WILL NOT BE EXTENDED...BUT SO FAR THE HEAT INDICES ARE
REMAINING JUST SUB ADVSY LEVEL.
SUNDAY SHOWERS AND THUNDERSTORMS ALSO POTENTIALLY PROBLEMATIC WITH A
WARM AND HUMID AIRMASS OUT AHEAD OF A BOUNDARY, SPC HAS PUT ALL OF
CENTRAL ILLINOIS IN A SLIGHT RISK FOR DAY 2. OVERNIGHT STORMS
TONIGHT MAY ALSO PROVIDE SOME OUTFLOW BOUNDARIES FOR FOCUS OF MORE
STORMS BEFORE THE ACTUAL FROPA. SHEAR MAINLY UNIDIRECTIONAL AND
LIKELY TO BE MORE OF A WIND AND HAIL THREAT AT THIS TIME. A LOT OF
THE SEVERE THREAT WILL BE DICTATED BY THE PREV NIGHT CONVECTION AND
WHAT IS LEFTOVER SUNDAY MORNING TO LIMIT THE ATMOSPHERE RECHARGING.
SUNDAY NIGHT THE PRECIP SHIFTS TO THE SOUTH WITH THE BOUNDARY
SLOWING A IT LOSES ITS PUSH ALOFT AND GETS HUNG UP IN MORE PARALLEL
FLOW. MONDAY/MONDAY NIGHT WILL SEE THE HIGHER POPS IN THE SOUTH,
ALTHOUGH THERE HAS BEEN SOME WAVERING AS TO WHERE THE BOUNDARY WILL
STALL AS ANOTHER WAVE EJECTS OUT OF THE WEST AND RIPPLES UP THE
BOUNDARY REMAINS. SIMILAR PATTERN TO HOW THIS SUMMER HAS BEEN GOING
SO FAR. ECMWF LINGERING PRECIP INTO TUESDAY AND THE SUPERBLEND
HANGING ONTO THE PRECIP. WILL LIKELY REMOVE SHOULD THE OTHER MODELS
CONTINUE THE DRYING TREND TO TUES/WED AS A WEAK NWRLY FLOW
ESTABLISHES ALOFT. A GENERAL WARMING TREND CONTINUES THROUGH THE
WEEK AS THE NEXT PATTERN SHIFT LINES UP FOR THE END OF THE WEEK WITH
A RETURN OF PRECIP CHANCES MOVES IN THURSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1150 PM CDT FRI JUL 17 2015
DEWPOINTS ARE QUITE HIGH ACROSS THE AREA AND WITH TEMPS FALLING TO
CLOSE TO DEWPOINTS AND WINDS BECOMING LIGHTER SOME...BELIEVE SOME
LIGHT FOG IS POSSIBLE OVERNIGHT. BELIEVE PIA/BMI/CMI WILL BE THE
SITES WHERE LIGHT FOG OF 4-5SM WILL BE PREDOMINATE. DEC AND SPI
WILL ONLY SEE A TEMPO GROUP AS TEMP/DWPT SPREADS ARE 6-8DEGREES
RIGHT NOW. OTHER THAN THE LIGHT FOG...WILL HAVE VFR CONDITIONS AT
ALL SITES REMAINDER OF THE PERIOD TOMORROW. WITH LOTS OF MOISTURE
AROUND...STILL THINK SOME CU IS POSSIBLE BUT SHOULD JUST BE
SCATTERED DURING THE DAY. CLOUDS WILL DISSIPATE DURING THE EVENING
BUT MODELS TRYING TO BRING IN SOME SCATTERED MID CLOUDS DURING
THE EVENING HOURS. WINDS WILL BE SOUTHERLY OVERNIGHT BUT THEN
BECOME SOUTHWESTERLY TOMORROW DURING THE DAY. DIRECTION LOOKS
VARIABLE TOMORROW EVENING BUT WIND SPEEDS SHOULD REMAIN 4-5KTS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR
ILZ044>046-054>057-061>063-066>068-071>073.
HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ILZ027>031-036>038-
040>043-047>053.
&&
$$
SHORT TERM...SMITH
LONG TERM...HJS
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
706 PM EDT SUN JUL 19 2015
.SYNOPSIS...
ISSUED AT 626 PM EDT SUN JUL 19 2015
A COLD FRONT WILL PUSH SOUTHWARD THROUGH THE REGION REACHING THE
OHIO RIVER VALLEY BY SUNRISE TOMORROW. A CHANCE FOR SHOWERS AND
THUNDERSTORMS WILL STAY ALONG AND AHEAD OF THE FRONT AS IT PUSHES
SOUTHWARD TONIGHT. BEHIND THE FRONT SKIES WILL BE CLEARING UP.
LOW TEMPERATURES TONIGHT WILL RANGE FROM THE LOWER 60S IN SOUTHERN
MICHIGAN TO THE LOWER 70S NEAR THE OHIO RIVER. HIGH PRESSURE WILL
BE OVER THE AREA MONDAY AS THE NEXT COLD FRONT APPROACHES FROM THE
NORTHWEST. HIGH TEMPERATURES ON MONDAY WILL RANGE FROM THE LOWER
80S IN SOUTHERN MICHIGAN TO THE MIDDLE 80S ALONG THE OHIO RIVER.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 343 PM EDT SUN JUL 19 2015
COLD FRONT IS CURRENTLY PUSHING SE THROUGH THE FORECAST AREA AS
OF 1930Z. SCATTERED CONVECTION HAS DEVELOPED AHEAD OF THE FRONT
FROM FORT WAYNE EASTWARD TO FINDLAY...WHERE SBCAPES HAVE REACHED
3000 TO 4000 J/KG. SHEAR IS WEAK WITH 500MB SPEED MAX WELL NORTH
OF THE AREA. FRONTAL FORCING IS WEAK AS WELL...WITH BETTER VEERING
WINDS AND LOWER TEMPS/DEWPOINTS WELL TO THE NORTHWEST. W/ MARGINAL
LAPSE RATES AND WEAK FORCING/SHEAR...EXPECT SEVERE THREAT TO BE
FAIRLY MINIMAL THROUGH THE REST OF THE AFTERNOON/EARLY EVENING.
ASIDE FROM A LOW DAMAGING WIND THREAT...HEAVY RAINFALL IS THE
PRIMARY THREAT GOING FORWARD...W/ PWATS MAXING OUT NEAR 2.00
INCHES SOUTH OF THE BOUNDARY.
AS FAR AS POPS GO...KEPT THEM IN THE CHANCE RANGE THROUGH 00Z...WITH
A GRADUAL DIMINISH FROM NORTH TO SOUTH AND THE FRONT CONTINUES TO
PUSH THROUGH THE AREA. THERE MAY BE AN UPTICK IN COVERAGE BETWEEN
21Z AND 00Z AS FRONTAL FORCING BECOMES A BIT STRONGER...HOWEVER HI
RES GUIDANCE...PARTICULARLY RECENT HRRR RUNS...HAVE SUGGESTED
MINIMAL ADDITIONAL COVERAGE THROUGH THIS TIME PERIOD. TAPERED OFF TO
DRY CONDITIONS AFTER 06Z...WITH CLEARING SKIES WORKING SOUTH THROUGH
THE FORECAST AREA AS WELL. LOWS SHOULD RANGE FROM THE LOW TO MID 60S
ACROSS THE AREA.
HIGH PRESSURE WILL MOVE QUICKLY ACROSS THE GREAT LAKES REGION LATE
OVERNIGHT THROUGH THE DAY MONDAY...AS THE FRONTAL BOUNDARY LINGERS
JUST SOUTH OF THE AREA. CLOUD COVER WILL INCREASE FROM THE WEST
THROUGH THE DAY AS A SHORTWAVE TRACKS EAST FROM KANSAS TOWARDS THE
OHIO VALLEY...AND ANOTHER COLD FRONT DROPS TOWARD THE AREA FROM THE
NORTHWEST. THIS MAY SPARK AN AFTERNOON THUNDERSTORM...MAINLY ACROSS
THE WEST/SOUTHWEST PART OF THE FORECAST AREA...AS VERY WEAK
DESTABILIZATION OCCURS...MAINLY SOUTHWEST OF THE FORECAST AREA.
CONFIDENCE IS LOW AT ANY PRECIP COVERAGE BEFORE 00Z...HOWEVER FOR
COLLABORATION SAKE...ADDED SLIGHT CHANCE POPS WEST/SOUTHWEST AFTER
21Z. HIGH TEMPS SHOULD REMAIN IN THE LOW TO MID 80S. WENT SLIGHTLY
COOLER THAN PREVIOUS FCST GIVEN EXPECTED CLOUD COVER AHEAD OF
UPSTREAM SYSTEMS.
&&
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 343 PM EDT SUN JUL 19 2015
DIFFUSE CDFNT MOVG THROUGH OUR AREA TODAY WILL STALL OUT OVER THE
OH VALLEY/MID MS VALLEY TONIGHT WITH REMNANT BOUNDARY AND
ASSOCIATED MOISTURE POOL LIFTING BACK N-NE MONDAY AS SHRTWV AND
ASSOCIATED CDFNT OVER SASK MOVES SE INTO THE UPR GRTLKS AND SECOND
VORT MAX OVER WY GETS INGESTED INTO THE WRLYS AND MOVES TO THE
MID MS VALLEY. COMBINATION OF THESE TWO FORCING MECHANISMS AND
RETURN MOISTURE/DESTABILIZATION MAY BE SUFFICIENT TO CAUSE SCT
TSTMS IN OUR AREA MONDAY NIGHT... CONTINUED WITH HIGHEST POPS
ACROSS SOUTHERN PORTION OF THE CWA CLOSER TO THE TRACK OF THE SRN
STREAM VORT MAX. THE NRN STREAM SHRTWV MOVG THROUGH THE UPR GRTLKS
WILL RESULT IN STRENGTHENING OF THE ONTARIO UPR LOW AND
AMPLIFICATION OF THE FLOW ALOFT ACROSS THE CENTRAL CONUS/CANADA.
THIS WILL ALLOW A RATHER STRONG SFC HIGH TO DRIFT SLOWLY SE-E FROM
THE NRN PLAINS ACROSS THE GRTLKS PROVIDING FAIR WX ACROSS OUR AREA
FOR THE REMAINDER OF THE WORK-WEEK. BY THE WEEKEND... SFC HIGH
SHOULD MOVE TO THE ERN CONUS WITH MOISTURE/INSTABILITY/WAA
RETURNING TO OUR AREA AND COMBINING WITH WK SHRTWV`S MOVG OVER THE
TOP OF THE SRN PLAINS/ROCKIES UPR HIGH BRINGING A CHC OF TSTMS
BACK TO OUR AREA. THE NW FLOW ALOFT SHOULD KEEP TEMPS BLO NORMAL
THROUGH THE WORKWEEK...PSBLY RISING BACK ABOVE NORMAL NEXT
WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 703 PM EDT SUN JUL 19 2015
VFR CONDS XPCD THROUGH THE PD AS WK SFC RIDGE MOVES TRAVERSES THE
AREA THIS PD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...LOTHAMER
SHORT TERM...NG
LONG TERM...JT
AVIATION...T
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
413 PM EDT SAT JUL 18 2015
.SYNOPSIS...
ISSUED AT 141 PM EDT SAT JUL 18 2015
HOT AND HUMID CONDITIONS WILL CONTINUE ACROSS THE REGION.
TEMPERATURES WILL WARM INTO THE 80S TO MIDDLE 90S THIS AFTERNOON.
HEAT INDEX VALUES FROM 100 TO 110 ARE POSSIBLE THIS AFTERNOON.
THERE IS A CHANCE FOR SHOWERS AND THUNDERSTORM THIS AFTERNOON
THROUGH TONIGHT AND AGAIN ON SUNDAY. IT WILL REMAIN WARM AND MUGGY
TONIGHT WITH LOWS ONLY DROPPING INTO THE 70S OVERNIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 412 PM EDT SAT JUL 18 2015
MORNING/EARLY AFTERNOON MCS IS CURRENTLY PUSHING OUT OF LOCAL
FORECAST AREA TO THE EAST. THIS HAS PRODUCED A NOTICABLE OUTFLOW
BOUNDARY CURRENTLY EXTENDING FROM MICHIGAN CITY SE TO PORTLAND.
HAVE REMOVED MANY OF THE COUNTIES NORTH OF THIS OUTFLOW FROM THE
HEAT ADVISORY...ESPECIALLY EAST OF A WARSAW TO THREE RIVERS LINE.
WHILE TEMPERATURES MAY RECOVER INTO THE MID 80S...HEAT INDICES
SHOULD REMAIN BELOW CRITERIA. ELSEWHERE...TEMPERATURES WILL HOVER
AROUND 90 WITH HEAT INDICES AROUND 100...SO THE HEAT ADVISORY WILL
CONTINUE INTO THE EVENING.
CURRENTLY MONITORING UPSTREAM CONVECTIVE TRENDS ACROSS NRN IL. HI
RES GUIDANCE HAS BEEN LITTLE HELP TODAY REGARDING CONVECTIVE
TRENDS...HOWEVER LATEST RADAR DATA SHOWS ORGANIZATION ACROSS FAR NW
IL/SRN WI. HRRR SUGGEST CONTINUED WARM SECTOR STORM DEVELOPMENT
FURTHER SOUTH FROM EAST CENTRAL IL INTO WESTERN IN. THESE STORMS MAY
POSE AN ISOLATED SEVERE WEATHER THREAT...WITH DAMAGING WINDS AND
HEAVY RAINFALL THE MAIN THREAT. FURTHER INTEREST LIES WITH THE
ORGANIZATION ACROSS NRN IL. ANTICIPATE THAT THIS FEATURE MAY
PROPAGATE E/SE TOWARDS THE AREA BETWEEN 22Z AND 01Z...RIDING ALONG
THE APPRECIABLE INSTABILITY GRADIENT DEMARCATED BY THE
AFOREMENTIONED OUTFLOW BOUNDARY. SBCAPE VALUES BUILDING TO 4000
TO 6000 J/KG SOUTH OF THIS OUTFLOW W/ MID LVL LAPSE RATES NEAR 6.5
C/KM. EFFECTIVE SHEAR VALUES ARE MARGINAL...FROM 20-30 KTS ACROSS
THE AREA...HOWEVER IF THIS LINE CAN ORGANIZE...WHICH IT APPEARS TO
BE DOING AS I WRITE THIS...SHOULD BE SUFFICIENT TO MAINTAIN INTO
THE NORTHWEST PART OF THE AREA AROUND 00Z AS A SQUALL LINE/BOW
ECHO. THIS WOULD PRODUCE A BETTER THREAT FOR DAMAGING
WINDS...POTENTIALLY SIGNIFICANT...ROUGHLY ALONG THE OUTFLOW
BOUNDARY FROM MICHIGAN CITY TO JUST SOUTH OF FORT WAYNE. OF
COURSE...WITH THIS OUTFLOW BOUNDARY SITUATED ACROSS THE AREA...ANY
STORMS THAT PROPAGATE ALONG IT WILL MAINTAIN A HIGHER TORNADO RISK
W/ ENHANCED LOW LVL SHEAR. HAVE REFLECTED THIS IN THE GRIDS WITH A
DAMAGING WIND MENTION...FROM NW TO SE ACROSS THE FORECAST AREA
FROM 22Z TO 03Z. WILL BE MONITORING THIS CLOSELY OVER THE NEXT
SEVERAL HOURS.
FORECAST PICTURE BECOMES SOMEWHAT MUDDLED AFTER 06Z...AND WILL HINGE
ON CONVECTIVE EVOLUTION BETWEEN NOW AND THEN. LARGER SCALE FRONT
WILL PUSH SE INTO THE AREA BY TOMORROW MORNING. HAVE BACKED OFF POPS
A BIT...ESPECIALLY NW...LATE TONIGHT THROUGH SUNDAY. HIGHEST POPS
ARE CURRENTLY SUNDAY AFTN AS THE FRONT IS LAYED OUT FROM SW TO NE
ACROSS THE FCST AREA. HIGH TEMPS SUNDAY WERE CUT JUST A BIT AS
WELL...MAINLY ACROSS THE NW PORTION OF THE FORECAST AREA. THERE MAY
BE A FEW LOCATIONS THAT HAVE HEAT INDICES APPROACH 100
TOMORROW...MAINLY SOUTH AND EAST OF FORT WAYNE. HOWEVER...WITH
UNCERTAINTY IN THE PRECIP EVOLUTION AND TEMPS...WILL HOLD OFF ON ANY
HEAT HEADLINES RIGHT NOW FOR SUNDAY.
&&
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 412 PM EDT SAT JUL 18 2015
CDFNT EXPECTED TO BE MOVG THROUGH SERN PORTION OF CWA SUNDAY
EVE WITH TSTMS PSBL ALONG IT IN THE EVE. SFC HIGH SHOULD BUILD
INTO THE AREA MONDAY PROVIDING FAIR WX. MID LEVEL CUT-OFF LOW OVER
IDAHO THIS AFTN IS EXPECTED TO SHEAR EASTWARD ACROSS THE MID MS/OH
VALLEY MONDAY NIGHT/TUE BRINGING A CHC OF SHOWERS TO THE AREA.
RIDGING EXPECTED TO MOVE ACROSS THE AREA WED-FRI RESULTING IN FAIR
WX WITH A SLOW WARMING TREND. RETURN FLOW BEHIND THE SFC HIGH
COMBINING WITH A WK SHRTWV TOPPING UPR RIDGE MAY BRING TSTMS BACK
INTO THE AREA ON SATURDAY. OVERALL... TEMPS EXPECTED TO BE A BIT
BLO NORMAL DURING THE LONG TERM PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 141 PM EDT SAT JUL 18 2015
HIGHLY UNCERTAIN TAF PD WITH THUNDERSTORMS NORTH OF KFWA EARLY
THIS AFTERNOON. EXPECT OUTFLOW BOUNDARY NOTED ON RADAR TO SHIFT
SOUTH THROUGH KFWA OVER THE FIRST COUPLE HOURS OF THE TAF
PD...WITH WINDS SHIFTING FROM THE NORTH AND BRIEF MVFR CIGS. NO
TSRA MENTION AT THIS TIME GIVEN UNCERTAINTY WITH TRACK OF CURRENT
STORMS...HOWEVER WILL MONITOR CLOSELY THROUGH 21Z AND AMEND KFWA
IF NEEDED.
ADDITIONAL THUNDERSTORMS POSSIBLE LATE THIS AFTERNOON INTO EVENING
AS AFOREMENTIONED OUTFLOW BOUNDARY REMAINS INVOF KSBN AND KFWA.
RIGHT NOW...HANDLED TAF FCST WITH VCTS MENTION...SIMILAR TO
YESTERDAY`S SETUP. WILL MONITOR THROUGH THE EVENING AND AMEND IF
TSRA ACTIVITY MATERIALIZES AND IS EXPECTED TO IMPACT TERMINALS.
OTHERWISE...VFR CONDS GENERALLY EXPECTED AFTER 02Z...WITH TSRA
CHANCES CONTINUING LATE IN THE FCST PERIOD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...HEAT ADVISORY UNTIL 9 PM EDT /8 PM CDT/ THIS EVENING FOR
INZ003>005-012>016-020-022>027-032>034.
MI...HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR MIZ077-078.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...LASHLEY/NG
SHORT TERM...NG
LONG TERM...JT
AVIATION...NG
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
149 PM EDT SAT JUL 18 2015
.SYNOPSIS...
ISSUED AT 141 PM EDT SAT JUL 18 2015
HOT AND HUMID CONDITIONS WILL CONTINUE ACROSS THE REGION.
TEMPERATURES WILL WARM INTO THE 80S TO MIDDLE 90S THIS AFTERNOON.
HEAT INDEX VALUES FROM 100 TO 110 ARE POSSIBLE THIS AFTERNOON.
THERE IS A CHANCE FOR SHOWERS AND THUNDERSTORM THIS AFTERNOON
THROUGH TONIGHT AND AGAIN ON SUNDAY. IT WILL REMAIN WARM AND MUGGY
TONIGHT WITH LOWS ONLY DROPPING INTO THE 70S OVERNIGHT.
&&
.UPDATE...
ISSUED AT 1013 AM EDT SAT JUL 18 2015
MAIN ADJUSTMENT W/ THIS FCST UPDATE IS TO INCREASE POPS ACROSS SRN
LWR MI AND FAR NE IN/NW OH THROUGH EARLY AFTN...AS WEAKENING MCS
DROPS SOUTHEAST FROM LK MI THIS MORNING. HI-RES MODEL GUIDANCES
DOING A VERY POOR JOB HANDLING THE EVOLUTION OF THIS
LINE...HOWEVER RADAR TRENDS SUGGEST IT WILL HOLD TOGETHER IN SOME
FORM INTO THE NORTHERN PART OF THE FCST AREA. SEVERE THREAT LOOKS
LOW AT THIS POINT...WITH RECENT UPSTREAM OBS SUGGESTING WIND
GUSTS AROUND 30 TO 40 MPH OVER THE LAST HOUR OR SO.
BIGGER CHALLENGE WILL BE THE IMPACT OF THIS LINE OF STORMS AND ITS
ATTENDANT OUTFLOW ON AFTN POPS...AS AIRMASS ACROSS NRN IN BECOMES
INCREASINGLY UNSTABLE INTO THE AFTN. FOR NOW...CONTINUED WITH
ISO/SLIGHT CHANCE MENTION THROUGH THE AFTN...WITH A SLIGHTLY
HIGHER POP NOTED ALONG/NORTH OF US 6...WHERE OUTFLOW IS EXPECTED
TO ANCHOR. ANOTHER CHALLENGE THE IMPACT OF THESE STORMS ON AFTN HI
TEMPS/HEAT INDICES. FOR NOW...MADE NO MAJOR CHANGES TO
TEMPS...ALTHOUGH DIURNAL HEATING WILL BE SLOWED/DELAYED WITH THIS
PRECIP AND CLOUD COVER...ESPECIALLY NORTH OF US 6. WILL CONTINUE
TO MONITOR TEMPERATURE AND CONVECTIVE TRENDS THROUGH THE MORNING
AND MAKE ADJUSTMENTS TO THE FCST THROUGHOUT THE DAY AS NEEDED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 440 AM EDT SAT JUL 18 2015
HEAT AND HUMIDITY ARE FIRST ISSUES TO DEAL WITH IN THE
SHORT TERM PERIOD FOLLOWED BY TSRA CHANCES THIS AFTERNOON AND
TONIGHT. SEVERAL AREAS OF UPSTREAM CONVECTION WILL BE PROBLEMATIC
FOR OUR AREA BOTH IN TERMS OF CLOUD COVER AND ANY CONVECTIVELY
ENHANCED SHORT WAVES THAT PROPAGATE EAST LATER TODAY AND TONIGHT.
PERSISTENT AREA OF TSRA HAS BEEN ONGOING MOST OF THE NIGHT IN THE
CHICAGO AREA AND THIS HAS KEPT ANVIL CLOUDS OVER NORTHERN INDIANA
AND NORTHWEST OHIO. EXPECT THIS CONVECTION TO DIMINISH TOWARD
SUNRISE AND CLOUD COVER TO THIN BUT SATELLITE SHOWING CIRRUS FROM
MN/IA CONVECTION PROGRESSING TOWARD THE AREA. SHOULD SEE THIS THIN
AS WELL BUT THIN VEIL OF CLOUDS TO LIKELY PERSIST TODAY AND INHIBIT
TEMP RISE BY A COUPLE DEGREES. STILL SHOULD SEE HIGHS REACH LOWER
90S MOST AREAS WITH MID 90S POSSIBLE IF CIRRUS REMAINS THIN THROUGH
THE DAY. DEW POINTS STILL EXPECTED TO RISE WELL INTO THE MIDDLE AND
UPPER 70S BUT MIX A BIT IN AFTERNOON BACK TO LOWER 70S. NO REAL
CHANGE TO GOING HEAT ADVISORY AS APPARENT TEMPS WILL STILL BE
BETWEEN 100 AND 105 WITH SOME AREAS REACHING 110.
THE HEAT AND HUMIDITY WILL HELP PUSH MUCAPES TO BETWEEN 4000-5000
J/KG THIS AFTERNOON. DEEP LAYER SHEAR REMAINS WEAK UNTIL LATER
TONIGHT WHEN WESTERLIES SINK CLOSER TO THE AREA. HOWEVER...LARGE
AMOUNT OF INSTABILITY AND WEAK CAP MAY ALLOW AN ISOLATED TSRA TO
DEVELOP DURING PEAK HEATING. OTHER ISSUE WILL BE EVOLUTION AND
PROPAGATION OF UPSTREAM MESOSCALE CONVECTIVE SYSTEMS. NMM AND ARW
WANT TO BRING SOME CONVECTION INTO NORTHERN AREAS THIS AFTERNOON.
LATEST RUNS OF HRRR AND RAP HAVE BEEN INCONSISTENT FROM RUN TO RUN.
LATEST HRRR BRINGS A LINE OF CONVECTION INTO THE NORTH EARLY THIS
EVENING. WILL CONTINUE WITH SLIGHT CHANCE POPS THIS AFTERNOON FOR
ANY PULSE STORMS THAT CAN BREAK CAP WITH HELP OF ANY WEAK SHORT
WAVES. RAISED POPS TO CHANCE CATEGORY THIS EVENING AND OVERNIGHT FOR
POSSIBLE MCS DEVELOPMENT.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 440 AM EDT SAT JUL 18 2015
THE CHALLENGES THIS PERIOD INCLUDE THE TIMING AND COVERAGE OF
STORMS AND THE CHANCE FOR ANOTHER DAY OF EXCESSIVE HEAT ON SUNDAY.
A COLD FRONT ASSOCIATED WITH A POSITIVELY TILTED UPPER TROF WILL
MOVE EAST TOWARD THE UPPER GREAT LAKES REGION. THERE IS MUCH
UNCERTAINTY CONCERNING THE LOCATION OF ONGOING CONVECTION AND
EARLIER STORM OUTFLOW BOUNDARIES THAT MAY ACCENTUATE THE
FRONT...OR CAUSE ANY THERMAL GRADIENT TO BECOME MORE DIFFUSE. HAVE
MAINTAINED LIKELY CHANCES FOR STORMS SUNDAY...WITH THE MENTION OF
THE CHANCE FOR HEAVY RAIN GIVEN THE APPROACH OF THE FRONT DURING
THE TIME OF PEAK HEATING DURING THE DAY. FOR NOW...HAVE HEAT
INDICES RISING INTO THE 90S...BUT STAYING JUST SHY OF THE CRITERIA
FOR A HEAT ADVISORY. GIVEN THESE PARAMETERS WITH THE INCREASE OF
MID LEVEL WINDS...THERE IS THE CHANCE SOME STORMS COULD BECOME
SEVERE. OTHERWISE...THE UPPER LEVEL RIDGE OVER THE SOUTH WILL
BUILD WEST...WITH PLENTY OF ENERGY TOPPING THE RIDGE OVER OUR
AREA. IN THIS REGARD...KEPT THE MENTION OF A CHANCE FOR STORMS
THURSDAY AND THURSDAY NIGHT. TEMPERATURES SHOULD BE CLOSE TO
NORMAL OR A FEW DEGREES BELOW NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 141 PM EDT SAT JUL 18 2015
HIGHLY UNCERTAIN TAF PD WITH THUNDERSTORMS NORTH OF KFWA EARLY
THIS AFTERNOON. EXPECT OUTFLOW BOUNDARY NOTED ON RADAR TO SHIFT
SOUTH THROUGH KFWA OVER THE FIRST COUPLE HOURS OF THE TAF
PD...WITH WINDS SHIFTING FROM THE NORTH AND BRIEF MVFR CIGS. NO
TSRA MENTION AT THIS TIME GIVEN UNCERTAINTY WITH TRACK OF CURRENT
STORMS...HOWEVER WILL MONITOR CLOSELY THROUGH 21Z AND AMEND KFWA
IF NEEDED.
ADDITIONAL THUNDERSTORMS POSSIBLE LATE THIS AFTERNOON INTO EVENING
AS AFOREMENTIONED OUTFLOW BOUNDARY REMAINS INVOF KSBN AND KFWA.
RIGHT NOW...HANDLED TAF FCST WITH VCTS MENTION...SIMILAR TO
YESTERDAY`S SETUP. WILL MONITOR THROUGH THE EVENING AND AMEND IF
TSRA ACTIVITY MATERIALIZES AND IS EXPECTED TO IMPACT TERMINALS.
OTHERWISE...VFR CONDS GENERALLY EXPECTED AFTER 02Z...WITH TSRA
CHANCES CONTINUING LATE IN THE FCST PERIOD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...HEAT ADVISORY UNTIL 9 PM EDT /8 PM CDT/ THIS EVENING FOR
INZ003>009-012>018-020-022>027-032>034.
MI...HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR MIZ077>081.
OH...HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR OHZ001-002-004-005-
015-016-024-025.
LM...NONE.
&&
$$
UPDATE...NG
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...SKIPPER
AVIATION...NG
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
146 PM EDT SAT JUL 18 2015
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 344 AM EDT SAT JUL 18 2015
A STRONG UPPER LEVEL RIDGE NOSING INTO THE AREA WILL MAKE FOR THE
HOTTEST DAY OF THE YEAR THUS FAR ACROSS CENTRAL INDIANA...WITH
HIGH TEMPERATURES IN THE LOW TO MID 90S AND HEAT INDEX VALUES IN
THE MID 100S. THE VERY HOT AND HUMID AIRMASS MAY ALLOW FOR
THUNDERSTORM DEVELOPMENT IN THE HEAT OF THE DAY ALONG REMNANT
BOUNDARIES FROM PRIOR CONVECTION. A MORE ORGANIZED FRONTAL SYSTEM
WILL APPROACH FROM THE NORTHWEST LATE TONIGHT AND DROP THROUGH THE
AREA SUNDAY INTO SUNDAY NIGHT...WITH STORMS LIKELY. THIS FRONTAL
BOUNDARY WILL BRING TEMPERATURES CLOSER TO NORMAL NEXT WEEK.
&&
.NEAR TERM /TODAY/...
ISSUED AT 1014 AM EDT SAT JUL 18 2015
.UPDATE...DROPPED TEMPERATURES SLIGHTLY SOME AREAS BASED ON CURRENT
TEMPERATURES AND WET GROUND. HOWEVER LOWER 90S WITH HEAT INDEX VALUES
FROM 101 TO 107 STILL LOOK GOOD. RAP SOUNDINGS LOOK MOSTLY CAPPED...
BUT I WOULD NOT RULE OUT AN ISOLATED THUNDERSTORM. NO OTHER UPDATES
ARE NEEDED AT THIS TIME.
PREVIOUS NEAR TERM DISCUSSION FOLLOWS...
HEIGHTS RISE ACROSS THE AREA TODAY AS THE RIDGE STRENGTHENS TO OUR
SOUTH...BUT WITH RESIDUAL BOUNDARIES FROM PRIOR CONVECTION AND A
VERY HOT AND HUMID AIRMASS IN PLACE...WITH DEWPOINTS WELL INTO THE
70S...WILL HAVE TO CARRY AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS
THIS AFTERNOON AND EVENING. OTHERWISE HEAT IS THE SIGNIFICANT
FORECAST VARIABLE.
CONSENSUS NUMBERS HAVE BEEN RUNNING COOL LATELY AND THIS LOOKS TO
BE THE CASE AGAIN. HAVE BUMPED THEM UP AT LEAST A COUPLE OF
DEGREES...AND EXPECT HIGHS TO REACH THE LOW TO MID 90S ACROSS THE
AREA. COUPLED WITH THE EXTREMELY HIGH DEWPOINTS...HEAT INDEX
VALUES WILL LIKELY REACH THE MID 100S. THIS IS COVERED WELL BY
PREVIOUSLY ISSUED HEAT ADVISORY.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 344 AM EDT SAT JUL 18 2015
STORMS FROM PEAK HEATING MAY LINGER INTO THE EVENING...AND THEN
ACROSS THE NORTH WILL REQUIRE POPS LATE TONIGHT AS THE FRONT
BEGINS TO APPROACH THE AREA. LIKELY POPS WILL BE REQUIRED SUNDAY
INTO SUNDAY NIGHT AS THIS BOUNDARY DROPS THROUGH THE AREA. AREA IS
OUTLOOKED DAY 2 AND THIS APPEARS REASONABLE. CHANCE POPS WILL BE
REQUIRED ACROSS THE SOUTH ON MONDAY NEARER THE LINGERING FRONTAL
BOUNDARY...AND THEN ACROSS THE ENTIRE AREA MONDAY NIGHT AS AN
UPPER LEVEL WAVE APPROACHES AND THE BOUNDARY BEGINS TO SHIFT BACK
NORTH.
CONSENSUS NUMBERS CONTINUE TO RUN COOL ON MAX TEMPS AND HAVE
ADJUSTED ACCORDINGLY. MIN TEMPS APPEAR MORE REASONABLE.
TEMPERATURES WILL BEGIN A GRADUAL RETURN TO MORE NORMAL NUMBERS
TOWARD THE END OF THE WEEKEND INTO EARLY NEXT WEEK.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 334 AM EDT SAT JUL 18 2015
UPPER RIDGE WILL RECENTER OVER THE HIGH PLAINS EARLY IN THE PERIOD
BEFORE SHIFTING BACK EAST AND EXPANDING INTO THE MISSISSIPPI
VALLEY BY NEXT WEEKEND AS AN UPPER LOW SHIFTS EAST INTO THE
CANADIAN MARITIMES. THIS WILL KEEP THE REGION ON THE RIDGE
PERIPHERY WITHIN A NORTHWEST FLOW PATTERN WITH AT LEAST A FEW
OPPORTUNITIES FOR STORMS.
GOOD CHANCE FOR SCATTERED STORMS TUESDAY WITH THE FRONTAL
BOUNDARY DROPPING SOUTH THROUGH THE OHIO VALLEY. HIGH PRESSURE
BUILDS IN BEHIND THE FRONT AND SHOULD PROVIDE AT LEAST A BRIEF
BREAK FROM THE STORMY WEATHER MIDWEEK. CONVECTIVE CHANCES WILL
RETURN THURSDAY AND FRIDAY AS A WARM FRONT APPROACHES FROM THE
WEST. APPEARS NOW THE POTENTIAL FOR HOTTER TEMPERATURES WILL HOLD
OFF UNTIL THE WEEKEND...WITH HIGHS PRIMARILY IN THE 80S THROUGH
THE EXTENDED.
&&
.AVIATION /DISCUSSION FOR 181800Z TAF ISSUANCE/...
ISSUED AT 131 PM EDT SAT JUL 18 2015
VFR CONDITIONS ANTICIPATED FOR MUCH OF THE FORECAST PERIOD.
HOWEVER MVFR VISIBILITIES ARE POSSIBLE LATE TONIGHT AT THE
OUTLYING TAF SITES AND LOWER FLIGHT CATEGORIES ARE ALSO POSSIBLE
IF ANY SHOWERS DEVELOP OVER THE AREA.
THE NEXT 24 HOURS IS VERY HARD TO FORECAST FOR SO FORECASTER
CONFIDENCE IS VERY LOW AS MODELS ARE ALL IN DISAGREEMENT IN SOME
FORM...MEANWHILE THE ENVIRONMENT MAY BECOME CONDITIONALLY UNSTABLE
ENOUGH TO NOT ONLY SUPPORT SHOWERS...BUT THUNDERSTORMS/CONVECTION
AS WELL EARLY THIS EVENING. FOR NOW WENT WITH SCATTERED SHOWERS
BEGINNING AROUND 21Z FOR THE WESTERN MOST SITES AND LEFT THIS IN
THROUGH EARLY THIS EVENING...THEN WENT DRY FOR THE OVERNIGHT.
SOME OF THE OUTLYING SITES WHICH ARE VERY MOISTURE LADEN AND COULD
SEE SOME CLEARING OF SKIES AND LIGHT TO CALM WINDS MAY HAVE SOME
MVFR BR EARLY SUNDAY MORNING. THEN BETTER CHANCE FOR SHOWERS AND
STORMS COMES LATER ON SUNDAY...WHICH WAS INDICATED WITH -SHRA AND
VCTS AT THIS TIME...SINCE PROJECTING WHEN AND WHERE A THUNDERSTORM
WILL OCCUR THIS FAR OUT IN TIME IS VERY DIFFICULT...BUT THE
POTENTIAL IS DEFINITELY THERE AND CONFIDENCE IS MUCH HIGHER FOR
PRECIP AND STORM CHANCES WITH A FRONTAL PASSAGE ON SUNDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR INZ021-028>031-
035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...NIELD
NEAR TERM...NIELD/JH
SHORT TERM...NIELD
LONG TERM...RYAN
AVIATION...SMF
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1036 AM EDT SAT JUL 18 2015
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 344 AM EDT SAT JUL 18 2015
A STRONG UPPER LEVEL RIDGE NOSING INTO THE AREA WILL MAKE FOR THE
HOTTEST DAY OF THE YEAR THUS FAR ACROSS CENTRAL INDIANA...WITH
HIGH TEMPERATURES IN THE LOW TO MID 90S AND HEAT INDEX VALUES IN
THE MID 100S. THE VERY HOT AND HUMID AIRMASS MAY ALLOW FOR
THUNDERSTORM DEVELOPMENT IN THE HEAT OF THE DAY ALONG REMNANT
BOUNDARIES FROM PRIOR CONVECTION. A MORE ORGANIZED FRONTAL SYSTEM
WILL APPROACH FROM THE NORTHWEST LATE TONIGHT AND DROP THROUGH THE
AREA SUNDAY INTO SUNDAY NIGHT...WITH STORMS LIKELY. THIS FRONTAL
BOUNDARY WILL BRING TEMPERATURES CLOSER TO NORMAL NEXT WEEK.
&&
.NEAR TERM /TODAY/...
ISSUED AT 1014 AM EDT SAT JUL 18 2015
.UPDATE...DROPPED TEMPERATURES SLIGHTLY SOME AREAS BASED ON CURRENT
TEMPERATURES AND WET GROUND. HOWEVER LOWER 90S WITH HEAT INDEX VALUES
FROM 101 TO 107 STILL LOOK GOOD. RAP SOUNDINGS LOOK MOSTLY CAPPED...
BUT I WOULD NOT RULE OUT AN ISOLATED THUNDERSTORM. NO OTHER UPDATES
ARE NEEDED AT THIS TIME.
PREVIOUS NEAR TERM DISCUSSION FOLLOWS...
HEIGHTS RISE ACROSS THE AREA TODAY AS THE RIDGE STRENGTHENS TO OUR
SOUTH...BUT WITH RESIDUAL BOUNDARIES FROM PRIOR CONVECTION AND A
VERY HOT AND HUMID AIRMASS IN PLACE...WITH DEWPOINTS WELL INTO THE
70S...WILL HAVE TO CARRY AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS
THIS AFTERNOON AND EVENING. OTHERWISE HEAT IS THE SIGNIFICANT
FORECAST VARIABLE.
CONSENSUS NUMBERS HAVE BEEN RUNNING COOL LATELY AND THIS LOOKS TO
BE THE CASE AGAIN. HAVE BUMPED THEM UP AT LEAST A COUPLE OF
DEGREES...AND EXPECT HIGHS TO REACH THE LOW TO MID 90S ACROSS THE
AREA. COUPLED WITH THE EXTREMELY HIGH DEWPOINTS...HEAT INDEX
VALUES WILL LIKELY REACH THE MID 100S. THIS IS COVERED WELL BY
PREVIOUSLY ISSUED HEAT ADVISORY.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 344 AM EDT SAT JUL 18 2015
STORMS FROM PEAK HEATING MAY LINGER INTO THE EVENING...AND THEN
ACROSS THE NORTH WILL REQUIRE POPS LATE TONIGHT AS THE FRONT
BEGINS TO APPROACH THE AREA. LIKELY POPS WILL BE REQUIRED SUNDAY
INTO SUNDAY NIGHT AS THIS BOUNDARY DROPS THROUGH THE AREA. AREA IS
OUTLOOKED DAY 2 AND THIS APPEARS REASONABLE. CHANCE POPS WILL BE
REQUIRED ACROSS THE SOUTH ON MONDAY NEARER THE LINGERING FRONTAL
BOUNDARY...AND THEN ACROSS THE ENTIRE AREA MONDAY NIGHT AS AN
UPPER LEVEL WAVE APPROACHES AND THE BOUNDARY BEGINS TO SHIFT BACK
NORTH.
CONSENSUS NUMBERS CONTINUE TO RUN COOL ON MAX TEMPS AND HAVE
ADJUSTED ACCORDINGLY. MIN TEMPS APPEAR MORE REASONABLE.
TEMPERATURES WILL BEGIN A GRADUAL RETURN TO MORE NORMAL NUMBERS
TOWARD THE END OF THE WEEKEND INTO EARLY NEXT WEEK.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 334 AM EDT SAT JUL 18 2015
UPPER RIDGE WILL RECENTER OVER THE HIGH PLAINS EARLY IN THE PERIOD
BEFORE SHIFTING BACK EAST AND EXPANDING INTO THE MISSISSIPPI
VALLEY BY NEXT WEEKEND AS AN UPPER LOW SHIFTS EAST INTO THE
CANADIAN MARITIMES. THIS WILL KEEP THE REGION ON THE RIDGE
PERIPHERY WITHIN A NORTHWEST FLOW PATTERN WITH AT LEAST A FEW
OPPORTUNITIES FOR STORMS.
GOOD CHANCE FOR SCATTERED STORMS TUESDAY WITH THE FRONTAL
BOUNDARY DROPPING SOUTH THROUGH THE OHIO VALLEY. HIGH PRESSURE
BUILDS IN BEHIND THE FRONT AND SHOULD PROVIDE AT LEAST A BRIEF
BREAK FROM THE STORMY WEATHER MIDWEEK. CONVECTIVE CHANCES WILL
RETURN THURSDAY AND FRIDAY AS A WARM FRONT APPROACHES FROM THE
WEST. APPEARS NOW THE POTENTIAL FOR HOTTER TEMPERATURES WILL HOLD
OFF UNTIL THE WEEKEND...WITH HIGHS PRIMARILY IN THE 80S THROUGH
THE EXTENDED.
&&
.AVIATION /DISCUSSION FOR 181200Z TAF ISSUANCE/...
ISSUED AT 1034 AM EDT SAT JUL 18 2015
1430Z UPDATE...NO CHANGES ARE NEEDED AT THIS TIME. PREVIOUS
DISCUSSION FOLLOWS.
VFR CONDITIONS ANTICIPATED FOR MUCH OF THE FORECAST PERIOD. MVFR
VISIBILITIES POSSIBLE LATE TONIGHT AT KLAF.
STILL HAVE POCKETS OF STRATOCU LINGERING UNDERNEATH CIRRUS
STREAMING INTO THE REGION FROM THE NORTH AND WEST. SHOULD SEE
STRATOCU MIX AND LIFT INTO A SCATTERED VFR CU FIELD BY MIDDAY WITH
SOME HIGHER CLOUDS. CONVECTIVE POTENTIAL LOOKS LOWER DURING THE
DAYLIGHT HOURS AS RIDGING ALOFT AND MID LEVEL TEMPERATURES BOTH
INCREASE THROUGH THE DAY. WITH STRONG INSTABILITY PRESENT ACROSS
CENTRAL INDIANA...EXPECT ISOLATED CONVECTION WILL DEVELOP DURING
PEAK HEATING IN THE AFTERNOON AND EVENING. W/SW WINDS WILL PEAK AT
10-15KTS THIS AFTERNOON.
EVEN LOWER UNCERTAINTY FOR TONIGHT WITH RESPECT TO POTENTIAL
IMPACTS FROM LARGER CONVECTIVE CLUSTER EXPECTED TO DEVELOP OVER
THE WESTERN GREAT LAKES BY EARLY EVENING. WRF GUIDANCE TRACKING
THIS ACTIVITY INTO THE NORTHERN FORECAST AREA BEFORE WEAKENING
TONIGHT WHICH LOOKS ENTIRELY PLAUSIBLE CONSIDERING STEERING
CURRENTS ALOFT. HIGHEST CONFIDENCE IN IMPACTS AT KLAF AND HAVE
INTRODUCED A VCTS MENTION AFTER 06Z. COULD SEE STORMS TRACK
FURTHER INTO THE AREA LATE TONIGHT AND IMPACT THE OTHER THREE
SITES...BUT CONFIDENCE IN THIS OCCURRING IS LOW WITH HIGHER
HEIGHTS AND WARMER AIR ALOFT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR INZ021-028>031-
035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...NIELD
NEAR TERM...NIELD/JH
SHORT TERM...NIELD
LONG TERM...RYAN
AVIATION...SMF/RYAN
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1021 AM EDT SAT JUL 18 2015
.SYNOPSIS...
ISSUED AT 116 AM EDT SAT JUL 18 2015
TODAY WILL BE VERY HOT AND HUMID ACROSS THE REGION. TEMPERATURES
WILL QUICKLY WARM INTO THE 80S THIS MORNING AND LOWER TO MIDDLE
90S THIS AFTERNOON. IT WILL BE VERY MUGGY AND THIS WILL MAKE IT
FEEL LIKE 100 TO 110 THIS AFTERNOON. THERE IS A SLIGHT CHANCE FOR
A LATE AFTERNOON THUNDERSTORM BUT BETTER CHANCES TONIGHT AND
SUNDAY. IT WILL REMAIN WARM AND MUGGY TONIGHT WITH TEMPERATURES
STAYING IN THE 80S THIS EVENING AND LOWS ONLY IN THE 70S
OVERNIGHT.
&&
.UPDATE...
ISSUED AT 1013 AM EDT SAT JUL 18 2015
MAIN ADJUSTMENT W/ THIS FCST UPDATE IS TO INCREASE POPS ACROSS SRN
LWR MI AND FAR NE IN/NW OH THROUGH EARLY AFTN...AS WEAKENING MCS
DROPS SOUTHEAST FROM LK MI THIS MORNING. HI-RES MODEL GUIDANCES
DOING A VERY POOR JOB HANDLING THE EVOLUTION OF THIS
LINE...HOWEVER RADAR TRENDS SUGGEST IT WILL HOLD TOGETHER IN SOME
FORM INTO THE NORTHERN PART OF THE FCST AREA. SEVERE THREAT LOOKS
LOW AT THIS POINT...WITH RECENT UPSTREAM OBS SUGGESTING WIND
GUSTS AROUND 30 TO 40 MPH OVER THE LAST HOUR OR SO.
BIGGER CHALLENGE WILL BE THE IMPACT OF THIS LINE OF STORMS AND ITS
ATTENDANT OUTFLOW ON AFTN POPS...AS AIRMASS ACROSS NRN IN BECOMES
INCREASINGLY UNSTABLE INTO THE AFTN. FOR NOW...CONTINUED WITH
ISO/SLIGHT CHANCE MENTION THROUGH THE AFTN...WITH A SLIGHTLY
HIGHER POP NOTED ALONG/NORTH OF US 6...WHERE OUTFLOW IS EXPECTED
TO ANCHOR. ANOTHER CHALLENGE THE IMPACT OF THESE STORMS ON AFTN HI
TEMPS/HEAT INDICES. FOR NOW...MADE NO MAJOR CHANGES TO
TEMPS...ALTHOUGH DIURNAL HEATING WILL BE SLOWED/DELAYED WITH THIS
PRECIP AND CLOUD COVER...ESPECIALLY NORTH OF US 6. WILL CONTINUE
TO MONITOR TEMPERATURE AND CONVECTIVE TRENDS THROUGH THE MORNING
AND MAKE ADJUSTMENTS TO THE FCST THROUGHOUT THE DAY AS NEEDED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 440 AM EDT SAT JUL 18 2015
HEAT AND HUMIDITY ARE FIRST ISSUES TO DEAL WITH IN THE
SHORT TERM PERIOD FOLLOWED BY TSRA CHANCES THIS AFTERNOON AND
TONIGHT. SEVERAL AREAS OF UPSTREAM CONVECTION WILL BE PROBLEMATIC
FOR OUR AREA BOTH IN TERMS OF CLOUD COVER AND ANY CONVECTIVELY
ENHANCED SHORT WAVES THAT PROPAGATE EAST LATER TODAY AND TONIGHT.
PERSISTENT AREA OF TSRA HAS BEEN ONGOING MOST OF THE NIGHT IN THE
CHICAGO AREA AND THIS HAS KEPT ANVIL CLOUDS OVER NORTHERN INDIANA
AND NORTHWEST OHIO. EXPECT THIS CONVECTION TO DIMINISH TOWARD
SUNRISE AND CLOUD COVER TO THIN BUT SATELLITE SHOWING CIRRUS FROM
MN/IA CONVECTION PROGRESSING TOWARD THE AREA. SHOULD SEE THIS THIN
AS WELL BUT THIN VEIL OF CLOUDS TO LIKELY PERSIST TODAY AND INHIBIT
TEMP RISE BY A COUPLE DEGREES. STILL SHOULD SEE HIGHS REACH LOWER
90S MOST AREAS WITH MID 90S POSSIBLE IF CIRRUS REMAINS THIN THROUGH
THE DAY. DEW POINTS STILL EXPECTED TO RISE WELL INTO THE MIDDLE AND
UPPER 70S BUT MIX A BIT IN AFTERNOON BACK TO LOWER 70S. NO REAL
CHANGE TO GOING HEAT ADVISORY AS APPARENT TEMPS WILL STILL BE
BETWEEN 100 AND 105 WITH SOME AREAS REACHING 110.
THE HEAT AND HUMIDITY WILL HELP PUSH MUCAPES TO BETWEEN 4000-5000
J/KG THIS AFTERNOON. DEEP LAYER SHEAR REMAINS WEAK UNTIL LATER
TONIGHT WHEN WESTERLIES SINK CLOSER TO THE AREA. HOWEVER...LARGE
AMOUNT OF INSTABILITY AND WEAK CAP MAY ALLOW AN ISOLATED TSRA TO
DEVELOP DURING PEAK HEATING. OTHER ISSUE WILL BE EVOLUTION AND
PROPAGATION OF UPSTREAM MESOSCALE CONVECTIVE SYSTEMS. NMM AND ARW
WANT TO BRING SOME CONVECTION INTO NORTHERN AREAS THIS AFTERNOON.
LATEST RUNS OF HRRR AND RAP HAVE BEEN INCONSISTENT FROM RUN TO RUN.
LATEST HRRR BRINGS A LINE OF CONVECTION INTO THE NORTH EARLY THIS
EVENING. WILL CONTINUE WITH SLIGHT CHANCE POPS THIS AFTERNOON FOR
ANY PULSE STORMS THAT CAN BREAK CAP WITH HELP OF ANY WEAK SHORT
WAVES. RAISED POPS TO CHANCE CATEGORY THIS EVENING AND OVERNIGHT FOR
POSSIBLE MCS DEVELOPMENT.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 440 AM EDT SAT JUL 18 2015
THE CHALLENGES THIS PERIOD INCLUDE THE TIMING AND COVERAGE OF
STORMS AND THE CHANCE FOR ANOTHER DAY OF EXCESSIVE HEAT ON SUNDAY.
A COLD FRONT ASSOCIATED WITH A POSITIVELY TILTED UPPER TROF WILL
MOVE EAST TOWARD THE UPPER GREAT LAKES REGION. THERE IS MUCH
UNCERTAINTY CONCERNING THE LOCATION OF ONGOING CONVECTION AND
EARLIER STORM OUTFLOW BOUNDARIES THAT MAY ACCENTUATE THE
FRONT...OR CAUSE ANY THERMAL GRADIENT TO BECOME MORE DIFFUSE. HAVE
MAINTAINED LIKELY CHANCES FOR STORMS SUNDAY...WITH THE MENTION OF
THE CHANCE FOR HEAVY RAIN GIVEN THE APPROACH OF THE FRONT DURING
THE TIME OF PEAK HEATING DURING THE DAY. FOR NOW...HAVE HEAT
INDICES RISING INTO THE 90S...BUT STAYING JUST SHY OF THE CRITERIA
FOR A HEAT ADVISORY. GIVEN THESE PARAMETERS WITH THE INCREASE OF
MID LEVEL WINDS...THERE IS THE CHANCE SOME STORMS COULD BECOME
SEVERE. OTHERWISE...THE UPPER LEVEL RIDGE OVER THE SOUTH WILL
BUILD WEST...WITH PLENTY OF ENERGY TOPPING THE RIDGE OVER OUR
AREA. IN THIS REGARD...KEPT THE MENTION OF A CHANCE FOR STORMS
THURSDAY AND THURSDAY NIGHT. TEMPERATURES SHOULD BE CLOSE TO
NORMAL OR A FEW DEGREES BELOW NORMAL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 637 AM EDT SAT JUL 18 2015
VFR CONDITIONS TO START THE PERIOD BUT UNCERTAINTY WITH TSRA
CHANCES THIS AFTERNOON AND OVERNIGHT. STRONG CAP EXPECTED TODAY
WITH HEAT BUT OUTFLOW BOUNDARIES FROM UPSTREAM CONVECTION AS WELL
AS POSSIBLE CONVECTIVELY INDUCED SHORT WAVE COULD BE ENOUGH TO
WEAKEN CAP LATE AFTERNOON AND EVENING WITH PLENTY OF INSTABILITY
FOR STRONG TSRA DEVELOPMENT. LOW CONFIDENCE IN COVERAGE...TIMING
AND LOCATION SO DID NOT ADD TSRA TO TAFS WITH THIS PACKAGE. KEPT
CONDITIONS VFR BUT MVFR AND IFR POSSIBLE WITH ANY TSRA THAT DO
DEVELOP.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...HEAT ADVISORY UNTIL 9 PM EDT /8 PM CDT/ THIS EVENING FOR
INZ003>009-012>018-020-022>027-032>034.
MI...HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR MIZ077>081.
OH...HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR OHZ001-002-004-005-
015-016-024-025.
LM...NONE.
&&
$$
UPDATE...NG
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...SKIPPER
AVIATION...LASHLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1014 AM EDT SAT JUL 18 2015
.UPDATE... NEAR TERM FOR THE REST OF TODAY HAS BEEN UPDATED
BELOW.
&&
.SYNOPSIS...
ISSUED AT 344 AM EDT SAT JUL 18 2015
A STRONG UPPER LEVEL RIDGE NOSING INTO THE AREA WILL MAKE FOR THE
HOTTEST DAY OF THE YEAR THUS FAR ACROSS CENTRAL INDIANA...WITH
HIGH TEMPERATURES IN THE LOW TO MID 90S AND HEAT INDEX VALUES IN
THE MID 100S. THE VERY HOT AND HUMID AIRMASS MAY ALLOW FOR
THUNDERSTORM DEVELOPMENT IN THE HEAT OF THE DAY ALONG REMNANT
BOUNDARIES FROM PRIOR CONVECTION. A MORE ORGANIZED FRONTAL SYSTEM
WILL APPROACH FROM THE NORTHWEST LATE TONIGHT AND DROP THROUGH THE
AREA SUNDAY INTO SUNDAY NIGHT...WITH STORMS LIKELY. THIS FRONTAL
BOUNDARY WILL BRING TEMPERATURES CLOSER TO NORMAL NEXT WEEK.
&&
.NEAR TERM /TODAY/...
ISSUED AT 1014 AM EDT SAT JUL 18 2015
.UPDATE...DROPPED TEMPERATURES SLIGHTLY SOME AREAS BASED ON CURRENT
TEMPERATURES AND WET GROUND. HOWEVER LOWER 90S WITH HEAT INDEX VALUES
FROM 101 TO 107 STILL LOOK GOOD. RAP SOUNDINGS LOOK MOSTLY CAPPED...
BUT I WOULD NOT RULE OUT AN ISOLATED THUNDERSTORM. NO OTHER UPDATES
ARE NEEDED AT THIS TIME.
PREVIOUS NEAR TERM DISCUSSION FOLLOWS...
HEIGHTS RISE ACROSS THE AREA TODAY AS THE RIDGE STRENGTHENS TO OUR
SOUTH...BUT WITH RESIDUAL BOUNDARIES FROM PRIOR CONVECTION AND A
VERY HOT AND HUMID AIRMASS IN PLACE...WITH DEWPOINTS WELL INTO THE
70S...WILL HAVE TO CARRY AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS
THIS AFTERNOON AND EVENING. OTHERWISE HEAT IS THE SIGNIFICANT
FORECAST VARIABLE.
CONSENSUS NUMBERS HAVE BEEN RUNNING COOL LATELY AND THIS LOOKS TO
BE THE CASE AGAIN. HAVE BUMPED THEM UP AT LEAST A COUPLE OF
DEGREES...AND EXPECT HIGHS TO REACH THE LOW TO MID 90S ACROSS THE
AREA. COUPLED WITH THE EXTREMELY HIGH DEWPOINTS...HEAT INDEX
VALUES WILL LIKELY REACH THE MID 100S. THIS IS COVERED WELL BY
PREVIOUSLY ISSUED HEAT ADVISORY.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 344 AM EDT SAT JUL 18 2015
STORMS FROM PEAK HEATING MAY LINGER INTO THE EVENING...AND THEN
ACROSS THE NORTH WILL REQUIRE POPS LATE TONIGHT AS THE FRONT
BEGINS TO APPROACH THE AREA. LIKELY POPS WILL BE REQUIRED SUNDAY
INTO SUNDAY NIGHT AS THIS BOUNDARY DROPS THROUGH THE AREA. AREA IS
OUTLOOKED DAY 2 AND THIS APPEARS REASONABLE. CHANCE POPS WILL BE
REQUIRED ACROSS THE SOUTH ON MONDAY NEARER THE LINGERING FRONTAL
BOUNDARY...AND THEN ACROSS THE ENTIRE AREA MONDAY NIGHT AS AN
UPPER LEVEL WAVE APPROACHES AND THE BOUNDARY BEGINS TO SHIFT BACK
NORTH.
CONSENSUS NUMBERS CONTINUE TO RUN COOL ON MAX TEMPS AND HAVE
ADJUSTED ACCORDINGLY. MIN TEMPS APPEAR MORE REASONABLE.
TEMPERATURES WILL BEGIN A GRADUAL RETURN TO MORE NORMAL NUMBERS
TOWARD THE END OF THE WEEKEND INTO EARLY NEXT WEEK.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 334 AM EDT SAT JUL 18 2015
UPPER RIDGE WILL RECENTER OVER THE HIGH PLAINS EARLY IN THE PERIOD
BEFORE SHIFTING BACK EAST AND EXPANDING INTO THE MISSISSIPPI
VALLEY BY NEXT WEEKEND AS AN UPPER LOW SHIFTS EAST INTO THE
CANADIAN MARITIMES. THIS WILL KEEP THE REGION ON THE RIDGE
PERIPHERY WITHIN A NORTHWEST FLOW PATTERN WITH AT LEAST A FEW
OPPORTUNITIES FOR STORMS.
GOOD CHANCE FOR SCATTERED STORMS TUESDAY WITH THE FRONTAL
BOUNDARY DROPPING SOUTH THROUGH THE OHIO VALLEY. HIGH PRESSURE
BUILDS IN BEHIND THE FRONT AND SHOULD PROVIDE AT LEAST A BRIEF
BREAK FROM THE STORMY WEATHER MIDWEEK. CONVECTIVE CHANCES WILL
RETURN THURSDAY AND FRIDAY AS A WARM FRONT APPROACHES FROM THE
WEST. APPEARS NOW THE POTENTIAL FOR HOTTER TEMPERATURES WILL HOLD
OFF UNTIL THE WEEKEND...WITH HIGHS PRIMARILY IN THE 80S THROUGH
THE EXTENDED.
&&
.AVIATION /DISCUSSION FOR 181200Z TAF ISSUANCE/...
ISSUED AT 710 AM EDT SAT JUL 18 2015
VFR CONDITIONS ANTICIPATED FOR MUCH OF THE FORECAST PERIOD. MVFR
VISIBILITIES POSSIBLE LATE TONIGHT AT KLAF.
STILL HAVE POCKETS OF STRATOCU LINGERING UNDERNEATH CIRRUS
STREAMING INTO THE REGION FROM THE NORTH AND WEST. SHOULD SEE
STRATOCU MIX AND LIFT INTO A SCATTERED VFR CU FIELD BY MIDDAY WITH
SOME HIGHER CLOUDS. CONVECTIVE POTENTIAL LOOKS LOWER DURING THE
DAYLIGHT HOURS AS RIDGING ALOFT AND MID LEVEL TEMPERATURES BOTH
INCREASE THROUGH THE DAY. WITH STRONG INSTABILITY PRESENT ACROSS
CENTRAL INDIANA...EXPECT ISOLATED CONVECTION WILL DEVELOP DURING
PEAK HEATING IN THE AFTERNOON AND EVENING. W/SW WINDS WILL PEAK AT
10-15KTS THIS AFTERNOON.
EVEN LOWER UNCERTAINTY FOR TONIGHT WITH RESPECT TO POTENTIAL
IMPACTS FROM LARGER CONVECTIVE CLUSTER EXPECTED TO DEVELOP OVER
THE WESTERN GREAT LAKES BY EARLY EVENING. WRF GUIDANCE TRACKING
THIS ACTIVITY INTO THE NORTHERN FORECAST AREA BEFORE WEAKENING
TONIGHT WHICH LOOKS ENTIRELY PLAUSIBLE CONSIDERING STEERING
CURRENTS ALOFT. HIGHEST CONFIDENCE IN IMPACTS AT KLAF AND HAVE
INTRODUCED A VCTS MENTION AFTER 06Z. COULD SEE STORMS TRACK
FURTHER INTO THE AREA LATE TONIGHT AND IMPACT THE OTHER THREE
SITES...BUT CONFIDENCE IN THIS OCCURRING IS LOW WITH HIGHER
HEIGHTS AND WARMER AIR ALOFT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
INZ021-028>031-035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...NIELD
NEAR TERM...NIELD/JH
SHORT TERM...NIELD
LONG TERM...RYAN
AVIATION...RYAN
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
642 AM EDT SAT JUL 18 2015
.SYNOPSIS...
ISSUED AT 116 AM EDT SAT JUL 18 2015
TODAY WILL BE VERY HOT AND HUMID ACROSS THE REGION. TEMPERATURES
WILL QUICKLY WARM INTO THE 80S THIS MORNING AND LOWER TO MIDDLE
90S THIS AFTERNOON. IT WILL BE VERY MUGGY AND THIS WILL MAKE IT
FEEL LIKE 100 TO 110 THIS AFTERNOON. THERE IS A SLIGHT CHANCE FOR
A LATE AFTERNOON THUNDERSTORM BUT BETTER CHANCES TONIGHT AND
SUNDAY. IT WILL REMAIN WARM AND MUGGY TONIGHT WITH TEMPERATURES
STAYING IN THE 80S THIS EVENING AND LOWS ONLY IN THE 70S
OVERNIGHT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 440 AM EDT SAT JUL 18 2015
HEAT AND HUMIDITY ARE FIRST ISSUES TO DEAL WITH IN THE
SHORT TERM PERIOD FOLLOWED BY TSRA CHANCES THIS AFTERNOON AND
TONIGHT. SEVERAL AREAS OF UPSTREAM CONVECTION WILL BE PROBLEMATIC
FOR OUR AREA BOTH IN TERMS OF CLOUD COVER AND ANY CONVECTIVELY
ENHANCED SHORT WAVES THAT PROPAGATE EAST LATER TODAY AND TONIGHT.
PERSISTENT AREA OF TSRA HAS BEEN ONGOING MOST OF THE NIGHT IN THE
CHICAGO AREA AND THIS HAS KEPT ANVIL CLOUDS OVER NORTHERN INDIANA
AND NORTHWEST OHIO. EXPECT THIS CONVECTION TO DIMINISH TOWARD
SUNRISE AND CLOUD COVER TO THIN BUT SATELLITE SHOWING CIRRUS FROM
MN/IA CONVECTION PROGRESSING TOWARD THE AREA. SHOULD SEE THIS THIN
AS WELL BUT THIN VEIL OF CLOUDS TO LIKELY PERSIST TODAY AND INHIBIT
TEMP RISE BY A COUPLE DEGREES. STILL SHOULD SEE HIGHS REACH LOWER
90S MOST AREAS WITH MID 90S POSSIBLE IF CIRRUS REMAINS THIN THROUGH
THE DAY. DEW POINTS STILL EXPECTED TO RISE WELL INTO THE MIDDLE AND
UPPER 70S BUT MIX A BIT IN AFTERNOON BACK TO LOWER 70S. NO REAL
CHANGE TO GOING HEAT ADVISORY AS APPARENT TEMPS WILL STILL BE
BETWEEN 100 AND 105 WITH SOME AREAS REACHING 110.
THE HEAT AND HUMIDITY WILL HELP PUSH MUCAPES TO BETWEEN 4000-5000
J/KG THIS AFTERNOON. DEEP LAYER SHEAR REMAINS WEAK UNTIL LATER
TONIGHT WHEN WESTERLIES SINK CLOSER TO THE AREA. HOWEVER...LARGE
AMOUNT OF INSTABILITY AND WEAK CAP MAY ALLOW AN ISOLATED TSRA TO
DEVELOP DURING PEAK HEATING. OTHER ISSUE WILL BE EVOLUTION AND
PROPAGATION OF UPSTREAM MESOSCALE CONVECTIVE SYSTEMS. NMM AND ARW
WANT TO BRING SOME CONVECTION INTO NORTHERN AREAS THIS AFTERNOON.
LATEST RUNS OF HRRR AND RAP HAVE BEEN INCONSISTENT FROM RUN TO RUN.
LATEST HRRR BRINGS A LINE OF CONVECTION INTO THE NORTH EARLY THIS
EVENING. WILL CONTINUE WITH SLIGHT CHANCE POPS THIS AFTERNOON FOR
ANY PULSE STORMS THAT CAN BREAK CAP WITH HELP OF ANY WEAK SHORT
WAVES. RAISED POPS TO CHANCE CATEGORY THIS EVENING AND OVERNIGHT FOR
POSSIBLE MCS DEVELOPMENT.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 440 AM EDT SAT JUL 18 2015
THE CHALLENGES THIS PERIOD INCLUDE THE TIMING AND COVERAGE OF
STORMS AND THE CHANCE FOR ANOTHER DAY OF EXCESSIVE HEAT ON SUNDAY.
A COLD FRONT ASSOCIATED WITH A POSITIVELY TILTED UPPER TROF WILL
MOVE EAST TOWARD THE UPPER GREAT LAKES REGION. THERE IS MUCH
UNCERTAINTY CONCERNING THE LOCATION OF ONGOING CONVECTION AND
EARLIER STORM OUTFLOW BOUNDARIES THAT MAY ACCENTUATE THE
FRONT...OR CAUSE ANY THERMAL GRADIENT TO BECOME MORE DIFFUSE. HAVE
MAINTAINED LIKELY CHANCES FOR STORMS SUNDAY...WITH THE MENTION OF
THE CHANCE FOR HEAVY RAIN GIVEN THE APPROACH OF THE FRONT DURING
THE TIME OF PEAK HEATING DURING THE DAY. FOR NOW...HAVE HEAT
INDICES RISING INTO THE 90S...BUT STAYING JUST SHY OF THE CRITERIA
FOR A HEAT ADVISORY. GIVEN THESE PARAMETERS WITH THE INCREASE OF
MID LEVEL WINDS...THERE IS THE CHANCE SOME STORMS COULD BECOME
SEVERE. OTHERWISE...THE UPPER LEVEL RIDGE OVER THE SOUTH WILL
BUILD WEST...WITH PLENTY OF ENERGY TOPPING THE RIDGE OVER OUR
AREA. IN THIS REGARD...KEPT THE MENTION OF A CHANCE FOR STORMS
THURSDAY AND THURSDAY NIGHT. TEMPERATURES SHOULD BE CLOSE TO
NORMAL OR A FEW DEGREES BELOW NORMAL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 637 AM EDT SAT JUL 18 2015
VFR CONDITIONS TO START THE PERIOD BUT UNCERTAINTY WITH TSRA
CHANCES THIS AFTERNOON AND OVERNIGHT. STRONG CAP EXPECTED TODAY
WITH HEAT BUT OUTFLOW BOUNDARIES FROM UPSTREAM CONVECTION AS WELL
AS POSSIBLE CONVECTIVELY INDUCED SHORT WAVE COULD BE ENOUGH TO
WEAKEN CAP LATE AFTERNOON AND EVENING WITH PLENTY OF INSTABILITY
FOR STRONG TSRA DEVELOPMENT. LOW CONFIDENCE IN COVERAGE...TIMING
AND LOCATION SO DID NOT ADD TSRA TO TAFS WITH THIS PACKAGE. KEPT
CONDITIONS VFR BUT MVFR AND IFR POSSIBLE WITH ANY TSRA THAT DO
DEVELOP.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...HEAT ADVISORY FROM NOON EDT /11 AM CDT/ TODAY TO 9 PM EDT /8 PM
CDT/ THIS EVENING FOR INZ003>009-012>018-020-022>027-
032>034.
MI...HEAT ADVISORY FROM NOON TODAY TO 9 PM EDT THIS EVENING FOR
MIZ077>081.
OH...HEAT ADVISORY FROM NOON TODAY TO 9 PM EDT THIS EVENING FOR
OHZ001-002-004-005-015-016-024-025.
LM...NONE.
&&
$$
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...SKIPPER
AVIATION...LASHLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
442 AM EDT SAT JUL 18 2015
.SYNOPSIS...
ISSUED AT 116 AM EDT SAT JUL 18 2015
TODAY WILL BE VERY HOT AND HUMID ACROSS THE REGION. TEMPERATURES
WILL QUICKLY WARM INTO THE 80S THIS MORNING AND LOWER TO MIDDLE
90S THIS AFTERNOON. IT WILL BE VERY MUGGY AND THIS WILL MAKE IT
FEEL LIKE 100 TO 110 THIS AFTERNOON. THERE IS A SLIGHT CHANCE FOR
A LATE AFTERNOON THUNDERSTORM BUT BETTER CHANCES TONIGHT AND
SUNDAY. IT WILL REMAIN WARM AND MUGGY TONIGHT WITH TEMPERATURES
STAYING IN THE 80S THIS EVENING AND LOWS ONLY IN THE 70S
OVERNIGHT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 440 AM EDT SAT JUL 18 2015
HEAT AND HUMIDITY ARE FIRST ISSUES TO DEAL WITH IN THE
SHORT TERM PERIOD FOLLOWED BY TSRA CHANCES THIS AFTERNOON AND
TONIGHT. SEVERAL AREAS OF UPSTREAM CONVECTION WILL BE PROBLEMATIC
FOR OUR AREA BOTH IN TERMS OF CLOUD COVER AND ANY CONVECTIVELY
ENHANCED SHORT WAVES THAT PROPAGATE EAST LATER TODAY AND TONIGHT.
PERSISTENT AREA OF TSRA HAS BEEN ONGOING MOST OF THE NIGHT IN THE
CHICAGO AREA AND THIS HAS KEPT ANVIL CLOUDS OVER NORTHERN INDIANA
AND NORTHWEST OHIO. EXPECT THIS CONVECTION TO DIMINISH TOWARD
SUNRISE AND CLOUD COVER TO THIN BUT SATELLITE SHOWING CIRRUS FROM
MN/IA CONVECTION PROGRESSING TOWARD THE AREA. SHOULD SEE THIS THIN
AS WELL BUT THIN VEIL OF CLOUDS TO LIKELY PERSIST TODAY AND INHIBIT
TEMP RISE BY A COUPLE DEGREES. STILL SHOULD SEE HIGHS REACH LOWER
90S MOST AREAS WITH MID 90S POSSIBLE IF CIRRUS REMAINS THIN THROUGH
THE DAY. DEW POINTS STILL EXPECTED TO RISE WELL INTO THE MIDDLE AND
UPPER 70S BUT MIX A BIT IN AFTERNOON BACK TO LOWER 70S. NO REAL
CHANGE TO GOING HEAT ADVISORY AS APPARENT TEMPS WILL STILL BE
BETWEEN 100 AND 105 WITH SOME AREAS REACHING 110.
THE HEAT AND HUMIDITY WILL HELP PUSH MUCAPES TO BETWEEN 4000-5000
J/KG THIS AFTERNOON. DEEP LAYER SHEAR REMAINS WEAK UNTIL LATER
TONIGHT WHEN WESTERLIES SINK CLOSER TO THE AREA. HOWEVER...LARGE
AMOUNT OF INSTABILITY AND WEAK CAP MAY ALLOW AN ISOLATED TSRA TO
DEVELOP DURING PEAK HEATING. OTHER ISSUE WILL BE EVOLUTION AND
PROPAGATION OF UPSTREAM MESOSCALE CONVECTIVE SYSTEMS. NMM AND ARW
WANT TO BRING SOME CONVECTION INTO NORTHERN AREAS THIS AFTERNOON.
LATEST RUNS OF HRRR AND RAP HAVE BEEN INCONSISTENT FROM RUN TO RUN.
LATEST HRRR BRINGS A LINE OF CONVECTION INTO THE NORTH EARLY THIS
EVENING. WILL CONTINUE WITH SLIGHT CHANCE POPS THIS AFTERNOON FOR
ANY PULSE STORMS THAT CAN BREAK CAP WITH HELP OF ANY WEAK SHORT
WAVES. RAISED POPS TO CHANCE CATEGORY THIS EVENING AND OVERNIGHT FOR
POSSIBLE MCS DEVELOPMENT.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 440 AM EDT SAT JUL 18 2015
THE CHALLENGES THIS PERIOD INCLUDE THE TIMING AND COVERAGE OF
STORMS AND THE CHANCE FOR ANOTHER DAY OF EXCESSIVE HEAT ON SUNDAY.
A COLD FRONT ASSOCIATED WITH A POSITIVELY TILTED UPPER TROF WILL
MOVE EAST TOWARD THE UPPER GREAT LAKES REGION. THERE IS MUCH
UNCERTAINTY CONCERNING THE LOCATION OF ONGOING CONVECTION AND
EARLIER STORM OUTFLOW BOUNDARIES THAT MAY ACCENTUATE THE
FRONT...OR CAUSE ANY THERMAL GRADIENT TO BECOME MORE DIFFUSE. HAVE
MAINTAINED LIKELY CHANCES FOR STORMS SUNDAY...WITH THE MENTION OF
THE CHANCE FOR HEAVY RAIN GIVEN THE APPROACH OF THE FRONT DURING
THE TIME OF PEAK HEATING DURING THE DAY. FOR NOW...HAVE HEAT
INDICES RISING INTO THE 90S...BUT STAYING JUST SHY OF THE CRITERIA
FOR A HEAT ADVISORY. GIVEN THESE PARAMETERS WITH THE INCREASE OF
MID LEVEL WINDS...THERE IS THE CHANCE SOME STORMS COULD BECOME
SEVERE. OTHERWISE...THE UPPER LEVEL RIDGE OVER THE SOUTH WILL
BUILD WEST...WITH PLENTY OF ENERGY TOPPING THE RIDGE OVER OUR
AREA. IN THIS REGARD...KEPT THE MENTION OF A CHANCE FOR STORMS
THURSDAY AND THURSDAY NIGHT. TEMPERATURES SHOULD BE CLOSE TO
NORMAL OR A FEW DEGREES BELOW NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 116 AM EDT SAT JUL 18 2015
CIRRUS BLOWOFF FROM UPSTREAM CONVECTION IN IL KEEPING KSBN CLOUDY
EARLY THIS MORNING AND THIS WILL INHIBIT BR DEVELOPMENT
INITIALLY. CLOUDS APPROACHING KFWA AS WELL. SATELLITE SHOWS SOME
THINNING BUT STILL OVC. ONCE SKIES PARTIALLY CLEAR SHOULD SEE
SOME MVFR BR DEVELOP WITH LIGHT WINDS. THIS WILL QUICKLY MIX AFTER
SUNRISE WITH SOUTHWEST WINDS 5 TO 10 KNOTS. A SLIGHT CHANCE FOR A
POP UP TSRA THIS AFTERNOON WITH HEAT BUT BUILDING RIDGE AND CAP
SHOULD KEEP THIS VERY ISOLATED AND TOO SMALL OF A CHANCE TO
MENTION IN TAFS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...HEAT ADVISORY FROM NOON EDT /11 AM CDT/ TODAY TO 9 PM EDT /8 PM
CDT/ THIS EVENING FOR INZ003>009-012>018-020-022>027-
032>034.
MI...HEAT ADVISORY FROM NOON TODAY TO 9 PM EDT THIS EVENING FOR
MIZ077>081.
OH...HEAT ADVISORY FROM NOON TODAY TO 9 PM EDT THIS EVENING FOR
OHZ001-002-004-005-015-016-024-025.
LM...NONE.
&&
$$
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...SKIPPER
AVIATION...LASHLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS DES MOINES IA
331 PM CDT SAT JUL 18 2015
.SHORT TERM /TONIGHT/...
ISSUED AT 328 PM CDT SAT JUL 18 2015
PRIMARY CONCERN WILL OBVIOUSLY REMAIN CONVECTIVE TRENDS INTO THE
NIGHT. IA CONTINUES TO BE INFLUENCED BY MODERATE WESTERLIES
UNDER MANITOBA SHORT WAVE TROUGH. STREAM OF WEAK SHORT WAVES
CONTINUES TO RIDE THIS FLOW FROM CO INTO IA WITH ONLY WEAK FORCING
NOTED IN OBJECTIVE RAP ANALYSIS AND SUBJECTIVE GLANCE AT WATER
VAPOR IMAGERY. 19Z SURFACE ANALYSIS SHOWS TWO AREAS OF GENESIS
CONCERN...ONE ALONG TRUE COLD FRONT MOVING THROUGH SIOUXLAND AREA
AND SECOND WITH TROUGH SW-NE THROUGH THE HEART OF IA. FORMER
AIRMASS IS UNCAPPED WITH CU DEVELOPMENT STARTING WITH SHOWERS OVER
SWRN MN...BUT RELATIVELY WEAK INSTABILITY...1000 J/G. THE LATTER
AIRMASS IS MORE UNSTABLE...2-3K J/KG...BUT STILL CAPPED WITH NON-
DESCRIPT CONVERGENCE. SOME CU HAS BEEN TRYING TO FORM IN THIS AREA
BUT LOOKS UNORGANIZED. FOR SENSIBLE WEATHER THIS MEANS PULLING LOW
END POPS INTO NWRN IA FOR A BIT...AND KEEPING PREVIOUSLY LOWERED
CHANCE POPS SE. MOST MODEL GUIDANCE SUGGESTS OUR BEST POTENTIAL
MAY BE FAR SOUTH LATER INTO THE NIGHT AS NOCTURNAL WARM ADVECTION
MATURES. RELATIVELY HIGHER EFFECTIVE SHEAR CONTINUES TO OVERSPREAD
IA...SO ANYTHING THE DOES GO COULD BECOME SEVERE WITH LARGE HAIL
AND DAMAGING WINDS THE HIGHEST THREATS WITH WEAK LOW LEVEL
KINEMATICS.
REGARDING THE PRESENT HEAT ADVISORY...WILL CANCEL SHORTLY AS 20Z
HEAT INDICES ARE NOT EVEN WITHIN 10 DEGREES OF CRITERIA WITH TEMPS
STRUGGLING TO TOP 90. A FEW SPOTS MAY JUST TOP 100F HI...BUT
THIS WOULD NOT SEEM TO JUSTIFY CURRENT WIDESPREAD HEADLINE.
.LONG TERM /SUNDAY THROUGH SATURDAY/...
ISSUED AT 328 PM CDT SAT JUL 18 2015
MAIN FORECAST CONCERN WAS FOCUSED ON SEVERE WEATHER POTENTIAL
LATE SUNDAY NIGHT INTO MONDAY AND TEMPERATURES THROUGH THE REST OF
THE WEEK. MODELS ARE IN DISARRAY WITH TIMING AND LOCATION OF THE
CONVECTION SUNDAY NIGHT THROUGH MONDAY AND LEANED TOWARD A BLEND
OF THE ECMWF/GFS/NAM.
SUNDAY INTO MONDAY...LARGE UPPER LEVEL RIDGE HOLDING IN PLACE OVER
THE LOWER MISSISSIPPI RIVER VALLEY AND SOUTHERN PLAINS WITH AN
UPPER LOW SLOWLY MOVING OVER ONTARIO SUNDAY AND MONDAY. THIS
PLACES IOWA GENERALLY IN ZONAL FLOW ALOFT WITH A SHORTWAVE TO CUT
ACROSS THE STATE EARLY MONDAY AHEAD OF A COLD FRONT TO PUSH
THROUGH LATER IN THE DAY. NAM AND ECMWF ARE FURTHER SOUTH WITH THE
SHORTWAVE THAN THE GFS AND THUS THE BULLSEYE OF QPF IS IN NORTHERN
MISSOURI. COLD FRONT LOOKS TO PUSH ACROSS THE STATE AND CLEAR THE
FORECAST AREA BY 00Z TUESDAY AT THE LATEST. NOT CONFIDENT THE
ATMOSPHERE WILL HAVE TIME TO DESTABILIZE AHEAD OF THE COLD FRONT
ONCE THE MORNING CONVECTION HAS CLEARED TO THE EAST MONDAY.
THINKING TIMING DIFFERENCE OF SHORTWAVE AND COLD FROPA ARE
MINIMAL...THUS ANY SEVERE WEATHER POTENTIAL MORE LIKELY WITH THE
SHORTWAVE. SHEAR IS UNIDIRECTIONAL AND INSTABILITY REMAINS LIMITED
EVEN AHEAD OF THE SHORTWAVE...SO ANY THREAT SEVERE THREAT WOULD BE
DAMAGING WINDS.
TUESDAY THROUGH FRIDAY...SURFACE HIGH PRESSURE AND LARGE UPPER
LEVEL RIDGE BUILD INTO THE STATE AND DOMINATE THROUGH MUCH OF
THE WORK WEEK. TRENDED TOWARD A DRIER FORECAST WITH THE ONLY
SIGNIFICANT CHANCE OF RAIN WEDNESDAY NIGHT INTO THURSDAY. WEAK
SHORTWAVE RIDES THE UPPER RIDGE BUT LOOKS TO DISSIPATE AS IT MOVES
EAST INTO IOWA THURSDAY. TRENDED DRIER THURSDAY OVER MUCH OF THE
AREA. TEMPERATURES REMAIN FAIRLY COOL THROUGHOUT THE WEEK WITH THE
COOLEST NIGHT ANTICIPATED ON TUESDAY NIGHT. LOWERED MINIMUM
TEMPERATURES DURING THIS TIME WITH DECENT RADIATIONAL COOLING
SETTING UP.
&&
.AVIATION...18/18Z
ISSUED AT 1256 PM CDT SAT JUL 18 2015
VFR THROUGH THE PERIOD UNTIL CONVECTIVE TRENDS BECOME MORE
CLEAR. STILL ANTICIPATING SOME SCATTERED STORMS WILL DEVELOP
DURING THE LATE AFTERNOON OR EVENING HOURS SOUTH AND EAST
SECTIONS...BUT CONFIDENCE IS LOW SO NO CHANGES BEYOND VFR VCTS
WORDING FOR NOW.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...REV
LONG TERM...PODRAZIK
AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1258 PM CDT SAT JUL 18 2015
.UPDATE...
ISSUED AT 1256 PM CDT SAT JUL 18 2015
OBJECTIVE ANALYSIS AT 1730Z WOULD SUGGEST FAVORABLE CONVERGENCE
AND UNCAPPED INSTABILITY IS HAVING DIFFICULTY COMING TOGETHER AT
THE MOMENT. RECENT RAP 0-1KM MOISTURE CONVERGENCE DOES ARC
BACKWARD FROM IL/WI MAX INTO S CENTRAL IA...BUT MUCH OF THIS
STILL HAS APPRECIABLE MLCINH IN OUR FORECAST AREA THIS FAR WEST.
MLCAPES ARE UNCAPPED FROM IL INTO WATERLOO WITH VALUES UP TO 2000
J/KG...BUT FAIRLY UNIFORM SWLY WINDS RESULT IN LITTLE CONVERGENCE
INTO NERN SECTIONS. FORECAST SOUNDINGS AND HI RES CONVECTION
ALLOWING MODELS ALL SUGGEST ANY GENESIS IN CENTRAL IA MAY TAKE
AWHILE DUE TO CAP. 17Z SUBJECTIVE SURFACE ANALYSIS SHOWS TRUE COLD
FRONT STILL UPSTREAM NW OF THE SIOUXLAND AREA WITH MORE OF A
PRESSURE TROUGH AND WEAK CONVERGENCE FROM KS INTO IA. THUS EARLY
AFTERNOON UPDATE WILL LIKELY PUSH BACK TIMING ON CONVECTIVE
INITIATION.
&&
.SHORT TERM /TODAY/...
ISSUED AT 355 AM CDT SAT JUL 18 2015
CONVECTIVE TRENDS THROUGHOUT THE DAY WILL BE THE PRIMARY FORECAST
CHALLENGE ALONG WITH THE SUBSEQUENT TRICKLE DOWN EFFECT TO THE
REMAINDER FORECAST ELEMENTS. OVERNIGHT THUNDERSTORMS FROM NORTHERN
IOWA AND INTO SOUTHERN MINNESOTA HAVE PUSHED AN OUTFLOW BOUNDARY
THROUGH THE NORTHWEST HALF OF THE STATE AND HAS BROUGHT A SWITCH TO
NORTHWEST WINDS AND HAS DROPPED DEWPOINTS INTO THE LOW TO MID 60S.
VERY GUSTY WINDS HAVE MAINTAINED OVER FAR NORTHWEST IOWA THE PAST
SEVERAL HOURS...ESPECIALLY AROUND THE STORM LAKE AREA WHERE GUSTS
HAVE BEEN AROUND 50 MPH. THE LATEST OB FROM STORM LAKE WITH A WIND
GUST TO 74 MPH SEEMS RELATED TO A HEAT BURST AS THE TEMPERATURE
JUMPED 15 DEGREES WHILE DEWPOINTS DROPPED TO 52. WILL NEED TO
MONITOR TO SEE IF THIS PHENOMENON BECOMES MORE WIDESPREAD.
CONVECTIVE TRENDS THROUGH THE MID MORNING HOURS SHOULD GRADUALLY
DIMINISH EXCEPT FOR POSSIBLE STORMS OVER FAR SOUTHWEST IOWA.
CONVECTIVE DEBRIS WILL BE AROUND FOR AT LEAST A PORTION THIS MORNING
AND WILL HELP SLOW TEMPERATURES OVER AT LEAST CENTRAL AND NORTHERN
IOWA. DEWPOINTS SHOULD RECOVER BY LATE MORNING AND INTO THE
AFTERNOON WITH SOME POOLING OCCURRING ALONG AND AHEAD OF A BOUNDARY
MOVING INTO NORTHWEST IOWA THIS AFTERNOON. POSSIBLE DEWPOINTS COULD
JUMP INTO THE UPPER 70S ALONG THE BOUNDARY. THE BEST CHANCE FOR
THUNDERSTORMS WILL BE ALONG THE BOUNDARY BY THIS AFTERNOON AS IT
SINKS INTO CENTRAL IOWA.
WILL BE ISSUING A HEAT ADVISORY AGAIN FOR THE SOUTHERN THREE TIER OF
COUNTIES WHERE HEAT INDEX VALUES SHOULD AGAIN BE NEAR 105. CURRENT
FORECAST FOR DSM WOULD PLACE THE METRO IN A 3RD STRAIGHT WITH MOIST
TROPICAL PLUS AIR MASS. THE MAIN UNCERTAINTY FOR INTERSTATE 80 AND
NORTH IS CLOUD COVER THROUGH THE DAY WHICH VERY WELL COULD KEEP
TEMPERATURES COOLER THAN FRIDAY THOUGH DEWPOINTS WILL BE SIMILAR.
.LONG TERM /TONIGHT THROUGH FRIDAY/...
ISSUED AT 355 AM CDT SAT JUL 18 2015
CONCERN FOR BEGINNING OF PERIOD WILL BE WITH PRECIPITATION CHANCES
AND THREAT FOR SEVERE WEATHER TONIGHT. MODELS...INCLUDING HIGH
RES...CONTINUE TO HOLD OFF ON PRECIPITATION DEVELOPMENT UNTIL
CLOSER TO 06Z...EXPECTING CAP TO REMAIN IN PLACE THROUGH AFTERNOON
AND EARLY EVENING BEFORE LLJ BEINGS TO INFLUENCE THE AREA.
HOWEVER...HAVE KEPT POPS IN THROUGH THE BEGINNING OF
PERIOD...EXPECTING ONGOING PRECIPITATION ACROSS THE AREA. BEST
CHANCES THROUGHOUT THE OVERNIGHT PERIOD WILL BE FOCUSED ALONG AND
SOUTH OF BOUNDARY...EXPECTED TO BE GENERALLY ACROSS SOUTHERN
PORTIONS OF THE CWA. WILL SEE A THREAT FOR HEAVY RAINFALL AGAIN IN
THIS AREA...WITH PWAT VALUES NEAR 1.9 INCHES AND GOOD WARM CLOUD
DEPTHS. MAY SEE POTENTIAL FOR FLASH FLOODING IN THE SOUTH
OVERNIGHT...BUT WILL HOLD OFF ON HEADLINES WITH PLACEMENT OF
PRECIPITATION STILL A BIT UNCERTAIN WITH SPEED OF BOUNDARY AND
POTENTIAL FOR REMNANTS OF OVERNIGHT CONVECTION TO INFLUENCE
CONVECTION. SHEAR WILL BE SOMEWHAT LACKING...BUT EXPECT
INSTABILITY TO BE STRONG ENOUGH TO OVERCOME LACKING SHEAR...MUCH
LIKE TONIGHT...TO WARRANT CHANCES FOR SEVERE THUNDERSTORMS EARLY
IN THE PERIOD.
BOUNDARY WILL PUSH SLOWLY SOUTH WITH PRECIPITATION CHANCES
LINGERING ALONG IT THROUGH SUNDAY MORNING IN THE SOUTH.
HOWEVER...MAY HAVE HELD ONTO CHANCES TOO LONG. WILL SEE A BREAK IN
HOT AND MUGGY CONDITIONS WITH A COOLER AIR MASS WORKING
IN...THOUGH TEMPS WILL STILL BE NEAR NORMAL....IN THE 80S. WAVE
WILL PUSH EAST THROUGH MOSTLY ZONAL FLOW FOR BEGINNING OF THE
WORK WEEK. HAVE INTRODUCED POPS FOR MONDAY WITH SYSTEM PUSHING
EAST...AND MODELS IN GOOD AGREEMENT ON TIMING AND PLACEMENT.
FORCING IS WEAK AND DO NOT HAVE HIGH CONFIDENCE. WEAK SURFACE HIGH
WILL KEEP CONDITIONS DRY UNTIL RIDGE BEGINS TO PUSH EAST FOR MID
WEEK. MODELS ARE NOT IN GOOD AGREEMENT WITH THIS SYSTEM. ECMWF IS
MUCH SLOWER...WITH BOTH ECMWF AND GEM KEEPING PRECIPITATION NORTH
AND SOUTH OF IOWA. GFS CONTINUES TO BRING SYSTEM THROUGH
IOWA...THOUGH BEST FORCING IS FURTHER SOUTH INTO MISSOURI.
THEREFORE...DO NOT HAVE HIGH CONFIDENCE AGAIN IN PRECIPITATION
CHANCES...BUT HAVE KEPT TRENDED TOWARDS THE GFS ATTM. WITH RIDGE
CONDITIONS WILL WARM FRIDAY...THOUGH WILL BE SHORT LIVED WITH
SECOND SYSTEM PUSHING EAST LATE FRIDAY...WITH ADDITIONAL
PRECIPITATION CHANCES INTO SATURDAY. AGAIN...NOT GOOD AGREEMENT ON
TIMING BETWEEN MODELS...AND HAVE BLENDED FOR NOW.
&&
.AVIATION...18/18Z
ISSUED AT 1256 PM CDT SAT JUL 18 2015
VFR THROUGH THE PERIOD UNTIL CONVECTIVE TRENDS BECOME MORE
CLEAR. STILL ANTICIPATING SOME SCATTERED STORMS WILL DEVELOP
DURING THE LATE AFTERNOON OR EVENING HOURS SOUTH AND EAST
SECTIONS...BUT CONFIDENCE IS LOW SO NO CHANGES BEYOND VFR VCTS
WORDING FOR NOW.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR ADAIR-ADAMS-
APPANOOSE-CASS-CLARKE-DALLAS-DAVIS-DECATUR-JASPER-LUCAS-MADISON-
MAHASKA-MARION-MONROE-POLK-POWESHIEK-RINGGOLD-TAYLOR-UNION-
WAPELLO-WARREN-WAYNE.
&&
$$
UPDATE...SMALL
SHORT TERM...DONAVON
LONG TERM...AWB
AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS DES MOINES IA
416 AM CDT SAT JUL 18 2015
.SHORT TERM /TODAY/...
ISSUED AT 355 AM CDT SAT JUL 18 2015
CONVECTIVE TRENDS THROUGHOUT THE DAY WILL BE THE PRIMARY FORECAST
CHALLENGE ALONG WITH THE SUBSEQUENT TRICKLE DOWN EFFECT TO THE
REMAINDER FORECAST ELEMENTS. OVERNIGHT THUNDERSTORMS FROM NORTHERN
IOWA AND INTO SOUTHERN MINNESOTA HAVE PUSHED AN OUTFLOW BOUNDARY
THROUGH THE NORTHWEST HALF OF THE STATE AND HAS BROUGHT A SWITCH TO
NORTHWEST WINDS AND HAS DROPPED DEWPOINTS INTO THE LOW TO MID 60S.
VERY GUSTY WINDS HAVE MAINTAINED OVER FAR NORTHWEST IOWA THE PAST
SEVERAL HOURS...ESPECIALLY AROUND THE STORM LAKE AREA WHERE GUSTS
HAVE BEEN AROUND 50 MPH. THE LATEST OB FROM STORM LAKE WITH A WIND
GUST TO 74 MPH SEEMS RELATED TO A HEAT BURST AS THE TEMPERATURE
JUMPED 15 DEGREES WHILE DEWPOINTS DROPPED TO 52. WILL NEED TO
MONITOR TO SEE IF THIS PHENOMENON BECOMES MORE WIDESPREAD.
CONVECTIVE TRENDS THROUGH THE MID MORNING HOURS SHOULD GRADUALLY
DIMINISH EXCEPT FOR POSSIBLE STORMS OVER FAR SOUTHWEST IOWA.
CONVECTIVE DEBRIS WILL BE AROUND FOR AT LEAST A PORTION THIS MORNING
AND WILL HELP SLOW TEMPERATURES OVER AT LEAST CENTRAL AND NORTHERN
IOWA. DEWPOINTS SHOULD RECOVER BY LATE MORNING AND INTO THE
AFTERNOON WITH SOME POOLING OCCURRING ALONG AND AHEAD OF A BOUNDARY
MOVING INTO NORTHWEST IOWA THIS AFTERNOON. POSSIBLE DEWPOINTS COULD
JUMP INTO THE UPPER 70S ALONG THE BOUNDARY. THE BEST CHANCE FOR
THUNDERSTORMS WILL BE ALONG THE BOUNDARY BY THIS AFTERNOON AS IT
SINKS INTO CENTRAL IOWA.
WILL BE ISSUING A HEAT ADVISORY AGAIN FOR THE SOUTHERN THREE TIER OF
COUNTIES WHERE HEAT INDEX VALUES SHOULD AGAIN BE NEAR 105. CURRENT
FORECAST FOR DSM WOULD PLACE THE METRO IN A 3RD STRAIGHT WITH MOIST
TROPICAL PLUS AIR MASS. THE MAIN UNCERTAINTY FOR INTERSTATE 80 AND
NORTH IS CLOUD COVER THROUGH THE DAY WHICH VERY WELL COULD KEEP
TEMPERATURES COOLER THAN FRIDAY THOUGH DEWPOINTS WILL BE SIMILAR.
.LONG TERM /TONIGHT THROUGH FRIDAY/...
ISSUED AT 355 AM CDT SAT JUL 18 2015
CONCERN FOR BEGINNING OF PERIOD WILL BE WITH PRECIPITATION CHANCES
AND THREAT FOR SEVERE WEATHER TONIGHT. MODELS...INCLUDING HIGH
RES...CONTINUE TO HOLD OFF ON PRECIPITATION DEVELOPMENT UNTIL
CLOSER TO 06Z...EXPECTING CAP TO REMAIN IN PLACE THROUGH AFTERNOON
AND EARLY EVENING BEFORE LLJ BEINGS TO INFLUENCE THE AREA.
HOWEVER...HAVE KEPT POPS IN THROUGH THE BEGINNING OF
PERIOD...EXPECTING ONGOING PRECIPITATION ACROSS THE AREA. BEST
CHANCES THROUGHOUT THE OVERNIGHT PERIOD WILL BE FOCUSED ALONG AND
SOUTH OF BOUNDARY...EXPECTED TO BE GENERALLY ACROSS SOUTHERN
PORTIONS OF THE CWA. WILL SEE A THREAT FOR HEAVY RAINFALL AGAIN IN
THIS AREA...WITH PWAT VALUES NEAR 1.9 INCHES AND GOOD WARM CLOUD
DEPTHS. MAY SEE POTENTIAL FOR FLASH FLOODING IN THE SOUTH
OVERNIGHT...BUT WILL HOLD OFF ON HEADLINES WITH PLACEMENT OF
PRECIPITATION STILL A BIT UNCERTAIN WITH SPEED OF BOUNDARY AND
POTENTIAL FOR REMNANTS OF OVERNIGHT CONVECTION TO INFLUENCE
CONVECTION. SHEAR WILL BE SOMEWHAT LACKING...BUT EXPECT
INSTABILITY TO BE STRONG ENOUGH TO OVERCOME LACKING SHEAR...MUCH
LIKE TONIGHT...TO WARRANT CHANCES FOR SEVERE THUNDERSTORMS EARLY
IN THE PERIOD.
BOUNDARY WILL PUSH SLOWLY SOUTH WITH PRECIPITATION CHANCES
LINGERING ALONG IT THROUGH SUNDAY MORNING IN THE SOUTH.
HOWEVER...MAY HAVE HELD ONTO CHANCES TOO LONG. WILL SEE A BREAK IN
HOT AND MUGGY CONDITIONS WITH A COOLER AIR MASS WORKING
IN...THOUGH TEMPS WILL STILL BE NEAR NORMAL....IN THE 80S. WAVE
WILL PUSH EAST THROUGH MOSTLY ZONAL FLOW FOR BEGINNING OF THE
WORK WEEK. HAVE INTRODUCED POPS FOR MONDAY WITH SYSTEM PUSHING
EAST...AND MODELS IN GOOD AGREEMENT ON TIMING AND PLACEMENT.
FORCING IS WEAK AND DO NOT HAVE HIGH CONFIDENCE. WEAK SURFACE HIGH
WILL KEEP CONDITIONS DRY UNTIL RIDGE BEGINS TO PUSH EAST FOR MID
WEEK. MODELS ARE NOT IN GOOD AGREEMENT WITH THIS SYSTEM. ECMWF IS
MUCH SLOWER...WITH BOTH ECMWF AND GEM KEEPING PRECIPITATION NORTH
AND SOUTH OF IOWA. GFS CONTINUES TO BRING SYSTEM THROUGH
IOWA...THOUGH BEST FORCING IS FURTHER SOUTH INTO MISSOURI.
THEREFORE...DO NOT HAVE HIGH CONFIDENCE AGAIN IN PRECIPITATION
CHANCES...BUT HAVE KEPT TRENDED TOWARDS THE GFS ATTM. WITH RIDGE
CONDITIONS WILL WARM FRIDAY...THOUGH WILL BE SHORT LIVED WITH
SECOND SYSTEM PUSHING EAST LATE FRIDAY...WITH ADDITIONAL
PRECIPITATION CHANCES INTO SATURDAY. AGAIN...NOT GOOD AGREEMENT ON
TIMING BETWEEN MODELS...AND HAVE BLENDED FOR NOW.
&&
.AVIATION...18/06Z
ISSUED AT 1203 AM CDT SAT JUL 18 2015
MCS OVER NEBRASKA WILL MOVE ACROSS IOWA OVERNIGHT...THOUGH
INSTABILITY REMAINS HIGH...LACK ORGANIZED SHEAR SHOULD RESULT IN
GRADUAL WEAKENING AS THE SYSTEM MOVES EAST NORTHEAST. HAVE ADDED
VCTS/VCSH BASED ON TIMING OF HRRR AND CURRENT TRENDS THROUGH 12Z.
OUTFLOW BOUNDARY TO LAY DOWN ACROSS CENTRAL/NORTHERN IOWA WHICH
WILL RESULT IN REDEVELOPMENT BETWEEN 18-21Z. EXACT TIMING AND
COVERAGE STILL IN QUESTION...SO CONFIDENCE LIMITED. IF STORMS HOLD
TOGETHER THROUGH 12Z...POSSIBLY SOME STRONG GUSTS NEAR KFOD AND
KMCW. /REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT THIS EVENING
FOR ADAIR-ADAMS-APPANOOSE-CASS-CLARKE-DAVIS-DECATUR-LUCAS-
MADISON-MAHASKA-MARION-MONROE-RINGGOLD-TAYLOR-UNION-WAPELLO-
WARREN-WAYNE.
&&
$$
SHORT TERM...DONAVON
LONG TERM...AWB
AVIATION...REV
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1207 AM CDT SAT JUL 18 2015
.SHORT TERM /TONIGHT/...
ISSUED AT 346 PM CDT FRI JUL 17 2015
AHEAD OF AN ADVANCING FRONT IN THE PLAINS...TEMPERATURES THIS
AFTERNOON HAVE WARMED TO THE THE LOWER AND MID 90S. DEWPOINTS
HAVE DECREASED THIS AFTERNOON IN SEVERAL LOCATIONS WITH SLIGHTLY
DRIER AIR MIXING DOWN TO THE SURFACE. HEAT INDEX VALUES HAVE RANGED
NEAR 100 TO 105 WITH THE HIGHEST HEAT INDICES IN SOUTHERN IOWA.
UPPER TROUGH NOTED ON WATER VAPOR IMAGERY WILL DIG INTO THE NORTHERN
PLAINS TONIGHT. THUNDERSTORMS WILL CONTINUE TO DEVELOP OVERNIGHT IN
THE NORTHERN PLAINS ALONG ADVANCING FRONT. THUNDERSTORM CHANCES
INCREASE AFTER MIDNIGHT ACROSS NORTH CENTRAL IOWA THROUGH DAY BREAK
WITH THE ARRIVAL OF THE FRONT. INSTABILITY AND SHEAR SUPPORT A
MARGINAL RISK FOR A FEW STRONG TO SEVERE THUNDERSTORMS.
.LONG TERM /SATURDAY THROUGH FRIDAY/...
ISSUED AT 346 PM CDT FRI JUL 17 2015
SATURDAY WILL BE HOT AND HUMID WITH SEVERE WEATHER POTENTIAL AT
TIMES...THEN THE FOLLOWING SEVERAL DAYS WILL SEE COOLER AND MOSTLY
DRY WEATHER. BY SUNRISE SATURDAY A POTENT 500 MB TROUGH WILL BE
SWINGING ACROSS NORTH DAKOTA AND SOUTHERN CANADA...PUSHING A
SURFACE COOL FRONT DOWN INTO FAR NORTHWESTERN IOWA. AS THE 500 MB
TROUGH MOVES RAPIDLY EASTWARD THE SURFACE FRONT WILL GRADUALLY SAG
INTO OUR AREA...LIKELY LYING ACROSS CENTRAL OR NORTHERN IOWA BY
AROUND 21Z. PRIOR TO THIS TIME...MODEST SOUTH SOUTHWEST SURFACE
FLOW AND MOISTURE POOLING SOUTH OF THE BOUNDARY WILL MAKE FOR
ANOTHER HOT AND VERY MUGGY DAY. THERE IS SOME QUESTION AS TO
WHETHER CONVECTION LATE TONIGHT ACROSS THE FAR NORTH WILL LEAVE
CONVECTIVE DEBRIS BEHIND BY MID MORNING SATURDAY...AND WHETHER IT
MAY PULL THE SYNOPTIC FRONT FURTHER SOUTH WITH IT THAN THE MODELS
ARE INDICATING. ALSO...THE ECMWF AND NAM HAVE PERSISTENTLY BEEN
DRIBBLING QPF AND MORE WIDESPREAD CLOUD COVER ACROSS CENTRAL IOWA
THROUGH THE DAY...WHICH WOULD OBVIOUSLY LIMIT DIURNAL HEATING.
HOWEVER...FORECAST SOUNDINGS INDICATE MOSTLY SUNNY SKIES AND A
CAPPING INVERSION FOR MOST OF THE DAY...WITH MOST HIGH RESOLUTION
MODELS SHOWING DRY CONDITIONS WHICH WILL PROMOTE MORE WARMING. FOR
NOW HAVE MAINTAINED A HIGH TEMPERATURE FORECAST CLOSE TO WHAT WAS
INHERITED...YIELDING PEAK HEAT INDEX VALUES IN THE 102 TO 104
RANGE ACROSS OUR SOUTH/SOUTHEAST COUNTIES. NO ADVISORY IS
THEREFORE BEING ISSUED AT THIS TIME...BUT THE OVERNIGHT SHIFT WILL
REASSESS SHORT TERM TRENDS AND MAKE A DETERMINATION AS TO WHETHER
OR NOT ONE WILL BE NECESSARY.
THERE WILL CLEARLY BE A VERY UNSTABLE AIRMASS AHEAD OF THE
APPROACHING FRONTAL BOUNDARY BY SATURDAY AFTERNOON. MOST OF THE
SUPPORTIVE DYNAMIC FORCING ASSOCIATED WITH THE UPPER LEVEL SYSTEM
WILL BE OFF TO OUR NORTHEAST AS THE 500 MB TROUGH DEPARTS...WHILE
ACROSS CENTRAL IOWA BULK SHEAR OF ABOUT 30 KNOTS IS FORECAST. THIS
SHOULD RESULT IN A THERMODYNAMICALLY DOMINANT SEVERE WEATHER
THREAT...WITH SCREAMING INSTABILITY AND THE BOUNDARY PROVIDING A
FAVORABLE ENVIRONMENT FOR SEVERE THUNDERSTORMS DESPITE THE
RELATIVE LACK OF UPPER SUPPORT. THE CONVECTIVE OUTLOOK FROM SPC
DESCRIBES THIS THREAT WELL. IT IS ALSO WORTH NOTING THAT THE
GFS...NMM AND ARW MODELS ARE NOT DEVELOPING ANY CONVECTION ACROSS
OUR AREA UNTIL AFTER SUNSET SATURDAY NIGHT WHEN THE LOW LEVEL JET
DEVELOPS. GFS FORECAST SOUNDINGS SHOW THE REASON...WITH A WARM
NUBBIN DEVELOPING AS AN EML MOVES IN FROM THE SOUTHWEST SATURDAY
AFTERNOON AND JUST BARELY KEEPING US CAPPED. THUS WE ARE LEFT WITH
AN ALL OR NOTHING FORECAST FOR THUNDERSTORMS SATURDAY AFTERNOON
AND EVENING...LIKELY BOOM OR BUST AS WE WILL EITHER STAY CAPPED
AND SEE SUNNY SKIES OR BREAK THE CAP AND HAVE MULTIPLE SEVERE
THUNDERSTORMS. FOR NOW HAVE DELAYED THE HIGHER POPS UNTIL AROUND
00Z BUT MAINTAINED 50 TO 60 PERCENT CHANCES ACROSS THE AREA IN
DEFERENCE TO THE VERY REAL SEVERE WEATHER THREAT AND A DESIRE TO
NOT FLIP FLOP THE FORECAST...PLUS IT SEEMS MORE LIKELY THAN NOT
THAT THE CAP WILL BREAK AND THUNDERSTORMS WILL DEVELOP. BY
SATURDAY NIGHT THE FRONT WILL HAVE MOVED SOUTH...LIKELY AIDED BY
CONVECTION...INTO SOUTHERN IOWA AND DOWN TOWARD THE MISSOURI
BORDER. IT IS INCREASINGLY PROBABLE THAT AS THE NOCTURNAL LOW
LEVEL JET DEVELOPS AND FEEDS INTO THE BOUNDARY FROM THE SOUTHWEST
IT WILL PROMOTE REGENERATION OF THUNDERSTORMS WITH A HEAVY RAIN
AND FLOODING THREAT. HOWEVER...AT THIS TIME IT IS DIFFICULT TO
DETERMINE WHETHER THIS WILL OCCUR IN OUR AREA OR DOWN IN NORTHERN
MISSOURI. HAVE MAINTAINED LIKELY POPS IN OUR FAR SOUTH TO ACCOUNT
FOR THIS...WITH THE BOUNDARY AND STORMS LIKELY PUSHING DOWN OUT OF
OUR AREA BY LATE MORNING OR MIDDAY SUNDAY.
AFTER COOLER AND QUIET WEATHER SUNDAY NIGHT...IT APPEARS THAT A
COMPACT BUT ROBUST 500 MB SHORTWAVE WILL MOVE QUICKLY ACROSS THE
AREA ON MONDAY AND MONDAY NIGHT...AND MAY GENERATE ADDITIONAL
THUNDERSTORMS ACROSS THE AREA. WHILE THERE IS DECENT FORCING FOR
CONVECTION...INSTABILITY WILL BE QUITE LIMITED AND CONFIDENCE IS
NOT HIGH IN THUNDERSTORM CHANCES RESULTING IN JUST SLIGHT CHANCE
POPS ACROSS THE NORTHERN HALF. ANY STORMS THAT DO OCCUR WILL NOT
POSE MUCH OF A SEVERE WEATHER THREAT. BEHIND THE MONDAY SHORTWAVE
A REINFORCING SHOT OF COOL AIR WILL PUSH SOUTHWARD INTO THE REGION
AS A LARGE HIGH PRESSURE CENTER BUILDS DOWN THE NORTHERN HIGH
PLAINS. THIS WILL KEEP US COOL AND DRY THROUGH TUESDAY. THEREAFTER
A ROUGHLY ZONAL STEERING PATTERN WILL PERSIST...WITH SLOWLY
MODERATING TEMPERATURES AND PERIODIC THUNDERSTORM CHANCES THROUGH
THE REMAINDER OF NEXT WEEK.
&&
.AVIATION...18/06Z
ISSUED AT 1203 AM CDT SAT JUL 18 2015
MCS OVER NEBRASKA WILL MOVE ACROSS IOWA OVERNIGHT...THOUGH
INSTABILITY REMAINS HIGH...LACK ORGANIZED SHEAR SHOULD RESULT IN
GRADUAL WEAKENING AS THE SYSTEM MOVES EAST NORTHEAST. HAVE ADDED
VCTS/VCSH BASED ON TIMING OF HRRR AND CURRENT TRENDS THROUGH 12Z.
OUTFLOW BOUNDARY TO LAY DOWN ACROSS CENTRAL/NORTHERN IOWA WHICH
WILL RESULT IN REDEVELOPMENT BETWEEN 18-21Z. EXACT TIMING AND
COVERAGE STILL IN QUESTION...SO CONFIDENCE LIMITED. IF STORMS HOLD
TOGETHER THROUGH 12Z...POSSIBLY SOME STRONG GUSTS NEAR KFOD AND
KMCW. /REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ANGLE
LONG TERM...LEE
AVIATION...REV
AREA FORECAST DISCUSSION
NWS GOODLAND KS
827 PM MDT SUN JUL 19 2015
.UPDATE...
ISSUED AT 825 PM MDT SUN JUL 19 2015
UPDATED GRIDS AND ZONES DUE TO CANCELLING SEVERE THUNDERSTORM
WATCH 444. ALSO CANCELLED THE FLASH FLOOD WATCH DUE TO STRONGER
STORMS WEAKENING AND MOVING OUT OF THE FA. DO NOT EXPECT ANY
ADDITIONAL STORMS OVERNIGHT THAT WOULD HAVE HEAVY RAINFALL
POTENTIAL.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 157 PM MDT SUN JUL 19 2015
COMPLICATED SURFACE PATTERN IN PLACE. EITHER OR SOME COMBINATION
OF A LEFT OVER OUTFLOW BOUNDARY...SURFACE TROUGH RETREATING FRONT
IS NOW NEAR OR OVER THE SOUTHERN PORTION OF THE AREA. SHORTWAVE
TROUGH IS STARTING TO MOVE THROUGH FROM THE SOUTH AND WEST. A WEAK
RIGHT REAR QUADRANT IS MOVING THROUGH THE AREA DURING THE NIGHT.
THE RAP IS CATCHING THE SURFACE WIND FIELD THE BEST RIGHT NOW. IT
AND THE HRRR WHICH DID WELL FROM LAST NIGHT...IS CATCHING THE WIND
FIELD AND THE CURRENT AND EXPECTED THUNDERSTORM DEVELOPMENT VERY
WELL RIGHT NOW. STORMS WILL CONTINUE INCREASE IN COVERAGE AND
INTENSITY THROUGH TONIGHT AS STORMS MOVE ACROSS THE AREA THROUGH
THE OVERNIGHT HOURS.
VERY UNSTABLE AIR MASS AND EXPECT SOME OF THESE STORMS TO BECOME
SEVERE. HOWEVER THE BIGGEST THREAT WILL BE THE HEAVY RAINFALL AND
POSSIBLE FLASH FLOODING. AIR MASS REMAINS VERY MOIST THROUGH A
DEEP DEPTH. WHERE THE THREAT FOR HEAVY RAINFALL MATCHES UP WITH
WHERE HEAVY RAINFALL/SOME FLASH FLOODING OCCURRED LAST NIGHT/EARLY
THIS MORNING IS OVER THE SOUTHERN HALF OF THE AREA. THEREFORE A
FLASH FLOOD WATCH HAS BEEN ISSUED THROUGH TONIGHT.
VERY LIGHT LINGERING RAINFALL MAY BE AROUND THROUGH MID MORNING.
AFTER THAT IT SHOULD STAY QUIET UNTIL MID AFTERNOON. WEST TO
NORTHWEST FLOW ALOFT WITH ANOTHER SHORTWAVE TROUGH TO MOVE
THROUGH. AIR MASS DOES NOT APPEAR AS MOIST. ALSO SURFACE BOUNDARY
LOOKS TO BE SOUTH OF AREA. MODELS ARE NOT VERY EXCITED ABOUT THE
AFTERNOON RAINFALL CHANCES. HOWEVER CONSIDERING THE RESIDUAL
MOISTURE IN PLACE AND A SHORTWAVE TROUGH IN A WEST TO NORTHWEST
FLOW ALOFT...AM KEEPING SLIGHT TO CHANCE POPS FOR NOW.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 254 PM MDT SUN JUL 19 2015
FOR THE EXTENDED FORECAST PERIOD...NEEDED TO MAKE SOME CHANGES FOR
THIS RUN AS MODELS HAVE COME INTO BETTER AGREEMENT WITH RESPECT TO
TWO FEATURES. FIRST...GUIDANCE IS HONING IN ON A MORE SOUTHERN
SOLUTION WITH REGARDS TO PRECIPITATION CHANCES MONDAY NIGHT THROUGH
TUESDAY NIGHT. THIS IS LIKELY DUE TO A FURTHER SOUTH PUSH FROM THE
FRONT THAN ORIGINALLY ANTICIPATED. SECOND...GUIDANCE IS IN BETTER
AGREEMENT ON THE LOCATION AND STRENGTH OF THE 500 MB HIGH PRESSURE
RIDGE THAT DEVELOPS TOWARDS THE END OF THE WEEK.
BEGINNING WITH MONDAY NIGHT...ANTICIPATE RELATIVELY QUIET WEATHER
DUE TO THE FRONT AND THUS CONVECTIVE ACTIVITY REMAINING FURTHER
SOUTH. SOME MODELS CONTINUE INDICATING ISENTROPIC LIFT DEVELOPING AS
A LOW LEVEL JET STRENGTHENS OVER THE FRONT. A NARROW TONGUE OF
INSTABILITY RETURNS WITHIN THE SOUTHEASTER FLOW EARLY TUESDAY
MORNING SO SOME ELEVATED SHOWERS/STORMS MAY BE ABLE TO DEVELOP. ALL
PARAMETERS ARE DELAYED BY 6-12 HOURS FROM YESTERDAY SO ACTIVITY MAY
HOLD OFF UNTIL AFTER SUNRISE TUESDAY. THEREFORE...LOWERED POPS FOR
MONDAY NIGHT.
FOR TUESDAY THROUGH WEDNESDAY...ANOTHER WET PERIOD IS ANTICIPATED.
UNCERTAINTY REMAINS ON THE EXACT AXIS WHERE THE RAIN WILL OCCUR. IN
ADDITION...THERE MAY BE A TIGHT GRADIENT BETWEEN LITTLE TO NO
RAINFALL AND ANOTHER ROUND OF BENEFICIAL SOAKING RAINS. THE BEST
FORCING SHOULD ARRIVE DURING THE DAY TUESDAY...SLOWLY TRANSITIONING
INTO CENTRAL KANSAS BY WEDNEDAY MORNING. THEREFORE...THE BEST
CHANCES FOR WIDESPREAD PRECIPITATION SHOULD OCCUR TUESDAY NIGHT WITH
CHANCES DIMINISHING WEDNESDAY. PRECIPITABLE WATER VALUES INCREASE
TUESDAY AND TUESDAY NIGHT...REACHING A MAXIMUM NEAR 1.60 INCHES BY
WEDNESDAY MORNING. THEREFORE...RAIN COULD BE HEAVY AT TIMES WITH
SOME THUNDERSTORMS.
BY LATE WEDNESDAY INTO THURSDAY...THE RIDGE OF HIGH PRESSURE OVER
THE SOUTHERN UNITED STATES SLIDES WEST AND STRENGTHENS/BUILDS NORTH
OVER THE HIGH PLAINS. THIS SHOULD LEAD TO AN END IN PRECIPITATION
CHANCES FOR THE MOST PART AS WELL AS A RETURN TO HOT TEMPERATURES.
FOR THURSDAY THROUGH AT LEAST NEXT WEEKEND...SOME MEMBERS OF THE
FORECAST GUIDANCE DO INDICATE CHANCES FOR ISOLATED THUNDERSTORMS.
HOWEVER...THERE IS NOT A CONSISTENT SIGNAL AMONGST THE GUIDANCE AND
NO TIME PERIODS IN PARTICULAR TO HONE IN ON. IN FACT...THINK THAT
MOST LIKELY THE REGION REMAINS DRY DUE TO CLOSENESS/STRENGTH OF THE
HIGH PRESSURE RIDGE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 456 PM MDT SUN JUL 19 2015
AFTER STORMS MOVE THROUGH KGLD AND KMCK THIS EVENING,VFR
CONDITIONS WILL RESUME AT BOTH SITES. SHORTWAVE ENERGY MOVING EAST
OF THE ROCKIES WILL SUPPORT CONTINUED THUNDERSTORM DEVELOPMENT
THIS EVENING. DO NOT SEE ANY STRATUS DEVELOPMENT BEHIND THE STORMS
MONDAY MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...FS
SHORT TERM...BULLER
LONG TERM...RRH
AVIATION...FS
...UPDATE TO AVIATION FORECAST DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 309 PM CDT SUN JUL 19 2015
THE UPPER LEVEL TROUGH AND MCV THAT HELPED PROVIDE ASCENT FOR THE
COMPLEX OF THUNDERSTORMS THAT MOVED ACROSS THE NORTHERN HALF OF THE
CWA THIS MORNING HAS NOW MOVED EAST ACROSS NORTHERN MO INTO IL. THE
NORTHERN COUNTIES OF THE CWA ALONG THE NE BORDER PICKED UP BETWEEN 2
TO 5 INCHES OF RAINFALL WHICH RESULTED IN SOME FLASH FLOODING
BETWEEN 6 AM-8AM. A SURFACE OUTFLOW BOUNDARY HAS MOVED SOUTH ACROSS
MUCH OF THE CWA...THOUGH THE SOUTHERN COUNTIES WERE BEGIN TO
RECOVER INTO THE LOWER 80S WITH MID 70 DEWPOINTS.
THE MESOSCALE MODELS DO NOT SHOW ANY THUNDERSTORMS DEVELOPING ALONG
THE OUTFLOW BOUNDARY ACROSS EAST CENTRAL KS. I`LL PROBABLY JUST GO
WITH 14 POPS FOR TONIGHT AND THROUGH MUCH OF THE EVENING HOURS.
EASTERLY UPSLOPE FLOW COMBINED WITH ASCENT FRONT ANOTHER WEAK UPPER
LEVEL TROUGH WILL CAUSE NUMEROUS SHOWERS AND THUNDERSTORMS TO
DEVELOP ACROSS THE HIGH PLAINS OF EASTERN CO AND WESTERN KS LATE
THIS AFTERNOON AND THROUGH THE EVENING HOURS. I EXPECT AN
MCS/COMPLEX OF THUNDERSTORMS TO DEVELOP ACROSS WESTERN KS DURING THE
MID EVENING HOURS AND TRACK EAST-NORTHEAST ACROSS EASTERN KS DURING
THE LATE EVENING AND MORNING HOURS OF MONDAY. THERE`S STILL SOME
UNCERTAINTY TO WHERE THE MCS WILL FORM AND TRACK. THE HRRR HAS BEEN
PERFORMING WELL BETWEEN 03Z-12Z THE PAST FEW DAYS AND SHOWS THE
COMPLEX OF STORMS DEVELOPING ACROSS WEST CENTRAL AND SOUTHWEST KS
AND MOVING NORTHEAST ACROSS THE NORTHERN COUNTIES OF THE CWA. THE
WRF SOLUTIONS ARE A BIT FARTHER SOUTH ALONG THE I-70 CORRIDOR. THE
12Z NAM SHOWS THE COMPLEX OF STORMS WEAKENING THROUGH THE EARLY
MORNING HOURS ONCE IT REACHES CENTRAL AND NORTH CENTRAL KS. DUE TO
THE HEAVY RAINFALL THIS MORNING ACROSS THE NORTHERN COUNTIES OF THE
CWA...AND THE CHANCE OF AN MCS OR COMPLEX OF STORMS MOVING ACROSS
THE SAME AREA DURING THE EARLY MORNING HOURS OF MONDAY...I HAVE
DECIDED TO ISSUE A FLASH FLOOD WATCH IN EFFECT FROM 9 PM THROUGH 11
AM MONDAY. THE FLASH FLOOD WATCH IS GENERALLY ALONG A MINNEAPOLIS TO
MANHATTAN...TO HOYT...TO OKALOOSA LINE. COUNTIES FARTHER SOUTH MAY
HAVE TO BE ADDED ON THIS EVENING IF THE MCS DEVELOPS FARTHER SOUTH
AND MOVES ACROSS THE CENTRAL OR SOUTHERN COUNTIES OF THE CWA. THE
ENVIRONMENT LATE TONIGHT AND THROUGH THE MORNING HOURS ACROSS
NORTHEAST KS WILL CONSIST OF 2000-3000 MUCAPE ALONG WITH 0-6KM
EFFECTIVE SHEAR OF 25 TO 35 KTS. THEREFORE SOME OF THE STRONGER
UPDRAFTS IN A COMPLEX OF STORMS MAY BE SEVERE WITH THE PRIMARY
HAZARD BEING DAMAGING WIND GUSTS AND HAIL UP TO HALF DOLLAR SIZE.
IF A FORWARD PROPAGATING MCS DEVELOPS THEN THERE MAY BE MORE
WIDESPREAD DAMAGING WIND GUSTS. ANY MCS OR COMPLEX OF
THUNDERSTORMS WILL PRODUCE HEAVY RAINFALL WITH FORECAST PWATS IN
THE 1.9-2.25 INCH RANGE.
MONDAY...THE COMPLEX OF STORMS WILL BE ONGOING ACROSS PORTIONS OF
THE CWA DURING THE MORNING HOURS. THE UPPER LEVEL TROUGH WILL MOVE
EAST-SOUTHEAST ACROSS EASTERN NE AND EASTERN KS DURING THE AFTERNOON
HOUR. THERE COULD BE A BREAK IN THE THUNDERSTORM CHANCES DURING THE
EARLY AFTERNOON HOURS BUT THE EASTERN COUNTIES MAY SEE NEW STORMS
DEVELOP ON A STRONGER SURFACE FRONT THAT WILL PUSH SOUTHEAST ACROSS
THE CWA DURING THE AFTERNOON HOURS. HIGHS WILL REMAIN COOLER DUE TO
THE MORNING RAIN CHANCES AND CLOUD COVER INTO THE EARLY AFTERNOON
HOURS. HIGHS WILL RANGE FROM THE MID 80S ALONG THE NE BORDER TO
LOWER 80S ACROSS THE SOUTHWEST COUNTIES.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 309 PM CDT SUN JUL 19 2015
MONDAY NIGHT THROUGH WEDNESDAY...PREVIOUSLY MENTIONED FRONT
PUSHES DOWN TO NEAR KS/OK BORDER BY MIDNIGHT MONDAY NIGHT. COULD
BE A FEW LINGERING STORMS IN THE EAST CENTRAL MONDAY EVENING.
AFTER MIDNIGHT...A WEAK SYSTEM MOVING THROUGH THE NEAR ZONAL FLOW
COMBINES WITH ISENTROPIC UPLIFT OVER THE THERMAL BOUNDARY TO GIVE
ANOTHER CHANCE FOR SHOWERS AND STORMS IN EAST CENTRAL KS AND
AREAS SOUTH. ON TUESDAY...SUBSIDENCE BEHIND WEAK WAVE AND
INFLUENCE OF SURFACE HIGH PRESSURE RIDGE SHOULD KEEP AREA DRY WITH
LOWER DEWPOINTS AND COOLER TEMPERATURES IN THE 80S.
ANOTHER WEAK TROUGH IN THE ZONAL FLOW ALOFT AFFECTS THE AREA ON
TUESDAY NIGHT AND WEDNESDAY. WHILE SURFACE BOUNDARY IS FORECAST BY
THE MODELS TO EDGE NORTHWARD...BEST LIFT SHOULD BE ACROSS THE
SOUTHERN HALF OF KS AND HAVE CONFINED HIGHEST POPS AND LARGER QPF
TO OUR EAST CENTRAL KS COUNTIES TO THE SOUTH OF I70.
THURSDAY THROUGH SUNDAY...LATE WEEK LOOKS TO HAVE SEVERAL ON AND
OFF CHANCES OF PRECIP. THURSDAY WILL LIKELY BE THE WETTEST DAY
WITH PLENTY OF SUBTROPICAL MOISTURE EXTENDING UP INTO THE REGION
AS WELL A COUPLE MID LEVEL IMPULSES WORKING OUT OF THE CENTRAL
ROCKIES AND OVER NORTHEASTERN KS. GENERALLY HAVE POPS DECREASING
HEADING INTO THURSDAY AFTERNOON TAPERING OFF FAIRLY SHARPLY BY
EVENING WITH A HIGHLY AMPLIFIED BUT NARROW UPPER RIDGE BUILDING
INTO THE CENTRAL PLAINS EXTENDING INTO THE UPPER MISSISSIPPI
VALLEY FOR FRIDAY. BY SATURDAY MORNING A BROADER MID LEVEL RIDGE
SITUATES ITSELF OVER THE SOUTHERN AND CENTRAL ROCKIES WITH A
NORTHWEST FLOW REGIME IN PLACE OVER THE OUTLOOK AREA. THIS WILL
LIKELY PROVIDE SOME SMALL CHANCES FOR SCATTERED PRECIP ON SATURDAY
MORNING MAINLY OVER AREAS NEAR THE KS/NE BORDER. THE LONG TERM
MODELS DIFFER A BIT AT THIS POINT AS THE ECMWF SUGGESTS THAT AN
MCS WILL HAVE DEVELOPED OVERNIGHT FRIDAY AND MOVE INTO THE REGION
BY SATURDAY MORNING, WHILE THE GFS AND CANADIAN SUGGEST THAT A
WEAK BOUNDARY WILL BE FORCED INTO THE AREA ASSOCIATED WITH THE
BROADER TROUGH OF THE WESTERLIES MOVING INTO THE UPPER MISSISSIPPI
VALLEY. EITHER WAY, IT DOES APPEAR THERE WILL BE AT LEAST SOME
SUPPORT FOR SHOWERS AND MORNING THUNDERSTORMS SATURDAY. WITH A
SITUATION THAT LOOKS TO LEAVE SEVERAL POTENTIAL BOUNDARIES IN PLAY
OVER THE REGION, SUNDAY COULD SEE ANOTHER CHANCE FOR PRECIP AS A
WEAK WAVE TURNS THE RIDGE AND INSTABILITY SETS UP WITH DAYTIME
HEATING.
HIGHS DURING THE PERIOD WILL LIKELY BE INTO THE 90S FOR FRIDAY
THROUGH SUNDAY WITH WARMEST TEMPERATURES IN PARTS OF CENTRAL KS.
LOWS LIKELY REMAIN IN THE 70S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 624 PM CDT SUN JUL 19 2015
TIMING OF OVERNIGHT CONVECTION MAIN CHALLENGE THIS TAF PERIOD.
WINDS BEGIN LIGHT AND VARIABLE...EXPECTED TO BECOME GUSTY AND
VARIABLE WITH RAIN. MHK HAVE STARTED AROUND 2AM WITH TEMPO GROUP
STARTING A FEW HOURS LATER AS POSSIBLE PRECIP SHIELD MOVES IN.
DOES LOOK TO CLEAR OUT IN THE MID TO LATER MORNING HOURS.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH MONDAY MORNING FOR KSZ008>012-020>024-
026-034.
&&
$$
SHORT TERM...GARGAN
LONG TERM...PHILLIPS/DRAKE
AVIATION...67
AREA FORECAST DISCUSSION
NWS JACKSON KY
134 PM EDT SAT JUL 18 2015
.UPDATE...
ISSUED AT 925 AM EDT SAT JUL 18 2015
WENT AHEAD AND UPDATED THE POPS TO INCLUDE ISOLATED CHANCES ACROSS
THE BOARD BY THIS AFTERNOON. WHILE THERE IS NOTHING GOING ON
ACROSS THE CWA AT THE MOMENT...SHOWERS ARE ALREADY STARTING TO POP
JUST TO OUR NORTH...SO DIDN/T FEEL COMFORTABLE NOT INCLUDING SOME
POSSIBILITY THAT OUR NORTHERN CWA WOULD SEE SOME OF THIS SHOWER
ACTIVITY. STILL THINK THE BEST ACTIVITY WILL DEVELOP ACROSS THE
SOUTHWEST CWA CLOSER TO THE LOCATION OF THE BOUNDARY...SO UPPED
POPS HERE AS WELL TO HIGH END ISOLATED. OVERALL...STILL EXPECT IT
TO BE A VERY HIT AND MISS DAY WITH ONLY LIGHT ACCUMULATIONS
EXPECTED UNDER THE SHOWERS THAT DO DEVELOP. BUT GIVEN THE CURRENT
RADAR WITH SHOWERS POPPING UP AND THE LATEST HI RES
MODELS...WANTED TO GO AHEAD AND INCLUDE EVERYONE IN THE ISOLATED
POTENTIAL.
THAT BEING SAID...THIS UPDATE ALSO INCLUDED AN UPDATE TO THE SKY
COVER...ESPECIALLY FOR THE MORNING HOURS AS HIGH CLOUDS ARE
ALREADY STARTING TO BUILD ACROSS THE AREA. INCREASED CLOUD
COVERAGE THROUGH THE AFTERNOON...BUT CHANGES WERE ONLY
MINOR...WITH FORECAST GROUPS NOW READING PARTLY CLOUDY INSTEAD OF
MOSTLY SUNNY BY THIS AFTERNOON WHEN SOME OF THE DIURNAL CLOUDS
BEGIN DEVELOPING. THIS WAS SUPPORTED BY THE LATEST NAM12 FORECAST
SOUNDINGS...AS WELL AS THE LATEST GFS40 FORECAST SOUNDING...THOUGH
CLOUD LAYERS MAY BE A BIT THINNER ACCORDING TO THE GFS.
FINALLY...ADJUSTED TEMPERATURES FOR TODAY SLIGHTLY. EVEN IF SOME
CLOUD COVER DEVELOPS...DON/T THINK IT WILL HAMPER THE WARM UP TOO
MUCH. AS SUCH...COUNTIES IN THE SW OF THE CWA ARE ALREADY SHOOTING
TO NEAR AND ABOVE 80 DEGREES...AS ARE A FEW IN THE NE CWA. WENT
AHEAD AND BUMPED UP HIGH TEMPERATURES FOR THESE LOCATION A COUPLE
DEGREES HIGHER...TO AROUND 92 INSTEAD OF 90. THIS ALSO MATCHED UP
BETTER WITH THE NEIGHBORING OFFICES WHO HAVE LOW TO MID 90S
FORECAST. WILL CONTINUE TO MONITOR TEMPS THROUGHOUT THE DAY IN
CASE ANY MORE ADJUSTMENTS/UPDATES ARE NEEDED...AS HIGH HUMIDITY
VALUES WILL PLAY A ROLE IN SOME POTENTIALLY PROBLEMATIC HEAT
INDEXES ACROSS THE REGION.
UPDATE ISSUED AT 736 AM EDT SAT JUL 18 2015
LAST OF THE EARLY MORNING SHOWERS HAVE PUSHED OUT OF THE
REGION...WITH DRY WEATHER LIKELY SETTING IN FOR THE REST OF THE
MORNING. HRRR HAS BEEN CONSISTENT ON SHOWING SOME REDEVELOPMENT
ACROSS EASTERN KENTUCKY THROUGH THE MORNING HOURS...BUT HAVE SEEN
NO EVIDENCE OF THIS HAPPENING YET. THUS...WILL MAINTAIN DRY
WEATHER OVER THE NEXT SEVERAL HOURS...BEFORE BRING SOME ISOLATED
SHOWERS/STORMS BACK IN THIS AFTERNOON WITH PEAK HEATING. MAIN AREA
OF FOCUS WILL BE A LEFT OVER OUTFLOW BOUNDARY THAT PUSHES SOUTH
ACROSS SOUTHERN KENTUCKY OVERNIGHT. THIS WILL BEAR WATCHING AS WE
HEAD INTO THE AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 250 AM EDT SAT JUL 18 2015
COMPLEX OF SHOWERS AND STORMS HAS WEAKENED CONSIDERABLY OVER THE
PAST FEW HOURS AS IT PUSHED INTO EASTERN KENTUCKY. BASED ON RADAR
TRENDS...IT LOOKS AS IF THE COMPLEX MIGHT SET UP A BOUNDARY ACROSS
SOUTHERN KENTUCKY...WHICH COULD TRIGGER ADDITIONAL SHOWER/STORMS
THROUGH DAYBREAK. THIS IDEA SEEMS TO BE WHAT THE LATEST HRRR IS
TRYING TO LATCH ONTO. HOWEVER...HI RES MODELS CONTINUE TO PERFORM
POORLY WITH VERY LITTLE CONSISTENCY. THUS...SHOWER/STORM CHANCES
WILL REMAIN LOW GIVEN THE DEGREE OF UNCERTAINTY. IT DOES LOOK LIKE
WE MAY END UP IN A HOLE OF SORTS TODAY...WITH CONVECTION STAYING
EAST/SOUTH/WEST OF THE AREA. THUS...WE COULD MANAGE A DRY DAY.
HOWEVER...WILL MAINTAIN SOME SLIGHT CHANCES GIVEN THE UNCERTAINTY.
BY TONIGHT...INSTABILITY SHOULD WANE AND RIDGE AXIS SHOULD PLANT
ITSELF OVER THE REGION. THUS...LOOKS LIKE A MUCH QUIETER NIGHT
TONIGHT. THE CLEAR SKIES AND LIGHT WINDS COULD YIELD SOME FOG
POTENTIAL IN THE VALLEYS.
ON SUNDAY...STILL NOT MUCH GOING ON WITH THE WEATHER. WE COULD SEE
A FEW SHOWERS OR STORMS POP UP WITH THE DAYTIME HEATING...BUT
SHOULD BE NOTHING WIDESPREAD AND ONLY WARRANTS A SLIGHT CHANCE AT
THIS POINT.
TEMPERATURES WILL REMAIN NEAR GUIDANCE OVER THE NEXT 36
HOURS...WITH HIGHS NEAR 90 WHICH CERTAINLY IS NOT UNCOMMON FOR
THIS TIME OF YEAR. HUMIDITY LEVELS WILL ALSO REMAIN ELEVATED
THROUGH THE WEEKEND...BUT ALSO FAIRLY TYPICAL FOR THIS TIME OF
YEAR. REGARDLESS...WITH THE SPS FOR HEAT ALREADY OUT...WILL JUST
RIDE WITH IT FOR NOW. IT DOES NOT LOOK LIKE WE WILL GET CLOSE TO
HEAT ADVISORY CRITERIA...ESPECIALLY GIVEN THAT TEMPERATURES MAY
NOT OVERACHIEVE GIVEN THE DEGREE OF GROUND SATURATION FROM RECENT
RAINS...WHICH MAY PUT THE CLAMPS ON HIGHS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 313 AM EDT SAT JUL 18 2015
NOT THE BEST OF AGREEMENT AMONGST THE GFS AND ECMWF MODELS THIS GO
ROUND. THE EXTENDED PORTION OF THE FORECAST WAS DERIVED FROM A
SLIGHTLY MODIFIED VERSION OF THE EXTENDED MODEL BLEND DATA. IN
GENERAL...THE FORECAST FOR THE UPCOMING WEEK IS SET TO FEATURE
PERIODS OF SHOWERS AND STORMS...MAINLY DURING THE AFTERNOON AND
EVENING HOURS. THE BEST CHANCE FOR RAIN AT THIS TIME APPEARS TO BE
MONDAY THROUGH TUESDAY...WHEN A FRONTAL BOUNDARY IS FORECAST TO
STALL ACROSS THE AREA. THE FRONT SHOULD FINALLY MAKE A
SOUTHEASTWARD PUSH ACROSS THE AREA TUESDAY NIGHT AND
WEDNESDAY...ALLOWING RAIN CHANCES TO DECREASE ACCORDINGLY. BY
WEDNESDAY MORNING...ONLY ISOLATED SHOWERS AND STORMS SHOULD
LINGER ACROSS EASTERN KENTUCKY. THAT TREND IS EXPECTED TO CONTINUE
THROUGH FRIDAY NIGHT...AS THE FRONT MAY STALL OUT JUST TO OUR
SOUTH...ALLOWING FOR A FEW SHOWERS AND STORMS TO FORM AS MOISTURE
FROM THE GULF OF MEXICO RIDES UP AND OVER THE BOUNDARY.
TEMPERATURES THROUGH OUT THE PERIOD WILL BE WARM AND MUGGY. DAY
TIME HIGHS WILL TOP OUT MOSTLY IN THE MID TO UPPER 80S...WITH A
FEW LOCATIONS PERHAPS BREAKING 90 ON MONDAY. OVERNIGHT LOWS WILL
BOTTOM OUT IN THE UPPER 60S AND LOWER 70S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 134 PM EDT SAT JUL 18 2015
A FEW POP UP SHOWERS AND THUNDERSTORMS WILL LIKELY CONTINUE
THROUGHOUT THE REMAINDER OF THE AFTERNOON. AS OF NOW...THEY ARE
NOT IMPACTING ANY TAF SITES...AND GIVEN THEIR LIMITED COVERAGE
AREA AND LIFESPAN...CHOSE NOT TO INCLUDE IN TAFS AT THIS TIME. IF
A SHOWER DOES IMPACT A TAF SITE...EXPECT ONLY A BRIEF REDUCTION
IN VISIBILITY. AS WE LOSE DAYTIME HEATING...THESE SHOWERS AND
THUNDERSTORMS WILL DISSIPATE AND HIGH PRESSURE WILL TAKE CONTROL.
THIS WILL ALLOW SKIES TO CLEAR SOME...BUT WILL ALSO TRAP LLVL
MOISTURE NEAR THE SURFACE AND LEAD TO SOME DECENT FOG
DEVELOPMENT...ESPECIALLY IN THE VALLEYS. THE FOG MAY LIFT ONTO THE
RIDGES AND AFFECT THE TAF SITES BEFORE DISSIPATING NEAR AND JUST
AFTER DAWN SUNDAY. AS SUCH...INCLUDED SOME IFR AND POSSIBLE LIFR
CONDITIONS FOR A COUPLE HOURS NEAR DAWN IN THE TAF. FOR
TOMORROW...HEAT AND HUMIDITY WILL CONTINUE...WITH SOME AFTERNOON
CONVECTION POSSIBLE ONCE MORE...ESPECIALLY IN THE FAR EASTERN
PORTION OF THE STATE. GIVEN THE LOW CONFIDENCE ON TIMING AND
LOCATION...CHOSE TO KEEP OUT OF TAFS. OTHERWISE...VFR CONDITIONS
ARE EXPECTED ACROSS THE BOARD WITH GENERALLY LIGHT WSW WINDS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JMW
SHORT TERM...KAS
LONG TERM...AR
AVIATION...JMW
AREA FORECAST DISCUSSION...UPDATED
NWS PADUCAH KY
1228 PM CDT SAT JUL 18 2015
.UPDATE...
ISSUED AT 1228 PM CDT SAT JUL 18 2015
THE AVIATION SECTION HAS BEEN UPDATED FOR THE 18Z TAF ISSUANCE.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 343 AM CDT SAT JUL 18 2015
THE CONSENSUS OF THE 00Z MODEL CYCLE IS THAT THE UPPER-LEVEL RIDGE
WILL HOLD STRONG ACROSS THE REGION THROUGH THE WEEKEND...AND THEN
IT WILL BE SUPPRESSED TO THE SOUTH/SOUTHWEST ON MONDAY. THE HEAT
ADVISORY LOOKS GOOD FOR TODAY AND SUNDAY. AT THIS TIME...DO NOT
SEE ANYTHING THAT WOULD INDICATE A NEED TO UPGRADE TO A WARNING.
THE MAIN CONCERN IS THE POTENTIAL FOR AT LEAST THE SOUTHERN HALF
OF THE AREA TO NEED A CONTINUATION INTO MONDAY. SINCE THE ENTIRE
AREA HAD 100+ HEAT INDICES YESTERDAY/FRIDAY...MONDAY WOULD BE THE
FOURTH CONSECUTIVE DAY OF 100+ HEAT INDICES WHICH WOULD SUPPORT A
CONTINUATION...EVEN IF ONLY 100-105 IS FORECAST. CONFIDENCE IN THE
MONDAY FORECAST IS QUITE LOW DUE TO A WEAK COLD FRONT AND
ASSOCIATED CONVECTION THAT IS EXPECTED TO BE DRAPED ACROSS THE
REGION. WILL LEAVE THE ADVISORY AS IS FOR NOW. AN UPDATED PRODUCT
WILL BE OUT BY 4 AM.
THE HRRR AND THE NMM AND ARW WRF RUNS ALL DEVELOP SOME ISOLATED TO
WIDELY SCATTERED THUNDERSTORMS OVER ROUGHLY THE EASTERN HALF OF
THE FORECAST AREA FROM MIDDAY TODAY THROUGH THIS AFTERNOON. THIS
WOULD BE DIURNAL ACTIVITY IN A VERY WEAK FLOW REGIME...SO A PULSY
STRONG STORM WILL BE POSSIBLE WITH ISOLATED STRONG WINDS...BUT
ORGANIZED SEVERE WEATHER IS NOT EXPECTED.
POPS WILL BE INCREASING FROM THE NORTH THROUGH THE DAY SUNDAY AND
MUCH OF SUNDAY NIGHT...AS A COLD FRONT APPROACHES THE REGION. THE
CONSENSUS OF 00Z GUIDANCE BRINGS THE FRONT INTO THE AREA IN THE
LATE EVENING AND PUSHES IT THROUGH THE ENTIRE AREA BY 15Z MONDAY.
WILL HAVE POPS UP TO LOW-END LIKELY LEVELS WITH THE FRONT ALONG
THE I-64 CORRIDOR SUNDAY NIGHT. SUNDAY IS LIKELY TO BE DRY...BUT
20-30 POPS ARE FORECAST MAINLY IN THE NORTH JUST TO BE SAFE. POPS
MONDAY WILL BE IN THE CHANCE RANGE DUE TO UNCERTAINTIES IN
FRONTAL LOCATION AND DIURNAL HEATING.
THE FLOW INCREASES SIGNIFICANTLY LATE SUNDAY NIGHT INTO
MONDAY...SO STORMS IN THIS PERIOD WILL LIKELY BE MORE ORGANIZED. A
FEW SEVERE STORMS WITH DAMAGING WINDS WILL BE POSSIBLE. OF COURSE
LOCALLY HEAVY RAINFALL AND FREQUENT LIGHTNING WILL ACCOMPANY ANY
THUNDERSTORMS THROUGH MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 343 AM CDT SAT JUL 18 2015
THIS EXTENDED FORECAST PACKAGE WOULD BE MORE FRUSTRATING TO DEAL
WITH CONSIDERING THE DAY TO DAY VARIATIONS OF THE DETERMINISTIC
GUIDANCE...PARTICULARLY THE GFS DETERMINISTIC MODEL. WITH THIS
PARTICULAR FORECAST PACKAGE...HAD TO FIGHT AGAINST THE EMPHASIS OF
THE DETERMINISTIC GFS GUIDANCE TO RETROGRADE THE SOUTHERN U.S. RIDGE
LATER IN THE WEEK TO ALLOW FOR FASTER AND SLIGHTLY WETTER FLOW AHEAD
OF THE RIDGE.
LOOKING AT THE WESTERN REGION FORECASTER CONFIDENCE TOOLKIT...THE
ENSEMBLE GUIDANCE...EVEN THE GFS ENSEMBLE CONTINUE TO HINT THAT THE
SOUTHERN U.S. RIDGE WILL REMAIN DOMINANT AND WILL NOT RETROGRADE
LATTER IN THE WEEK. CIPS AND OTHER ANALYSIS/ANALOG/ENSEMBLE PLOTS
CONTINUE TO HINT THAT NEXT WEEKEND /JULY 25-26/ WILL BE THE WARMEST
AND DRIEST SO FAR THIS SUMMER. I WOULD NOT BE SURPRISED IF A SPOT OR
TWO IN SOUTHEAST MISSOURI REACHES 98-100...ESPECIALLY BY NEXT
SATURDAY OR SUNDAY.
WITH THE ADJUSTMENT OF THE GRIDDED FORECAST TOWARD THE WARMER AND
DRIER SOLUTION...ADJUSTED DEWPOINTS DOWNWARD 1-2 DEGREES AND LOWERED
OPAQUE CLOUD COVER INTO THE PARTLY CLOUDY CATEGORY VERSUS MOSTLY
CLOUDY. ALL OF THESE CHANGES WILL SUGGEST AND SUPPORT GREATER
EVAPORATION AND INSOLATION...LEADING TO A LONGER DRY SPELL FOR THE
REGION.
FROM A HEAT STANDPOINT...IT LOOKS LIKE NEXT SATURDAY WILL BRING A
RETURN TO A HEAT ADVISORY (OR HIGHER) TO SOUTHEAST MISSOURI...WITH
HEAT INDEX VALUES NEAR 110 WIDESPREAD ON THAT DAY. SUNDAY DOES NOT
LOOK MUCH BETTER.
THERE REMAINS SOME CHALLENGE AS TO THE IMPACT AND COVERAGE OF
PRECIPITATION TUESDAY THROUGH THURSDAY OF NEXT WEEK.
HOWEVER...DEPENDING ON THE INTERPLAY BETWEEN THE RIDGE AND THE FAST
ZONAL FLOW JUST NORTH OF THE RIDGE...THE WFO PAH FORECAST AREA MAY
STILL SEE SOME CONVECTIVE ACTIVITY THROUGH THURSDAY.
&&
.AVIATION...
ISSUED AT 1228 PM CDT SAT JUL 18 2015
A RIDGE OF HIGH PRESSURE ALOFT SHOULD PRECLUDE THE DEVELOPMENT OF
CONVECTION AND KEEP ALL SITES VFR THROUGH THE PERIOD. SOUTHWEST
WINDS AT 8-14 KNOTS WILL DROP OFF TO AOB 5 KNOTS AROUND 00Z...THEN
SWING AROUND TO WESTERLY AOB 5 KNOTS MAINLY AFTER 15Z.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR ILZ075>078-080>094.
MO...HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR MOZ076-086-087-100-
107>112-114.
IN...HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR INZ081-082-085>088.
KY...HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR KYZ001>022.
&&
$$
SHORT TERM...DRS
LONG TERM...SMITH
AVIATION...JP
AREA FORECAST DISCUSSION
NWS JACKSON KY
925 AM EDT SAT JUL 18 2015
.UPDATE...
ISSUED AT 925 AM EDT SAT JUL 18 2015
WENT AHEAD AND UPDATED THE POPS TO INCLUDE ISOLATED CHANCES ACROSS
THE BOARD BY THIS AFTERNOON. WHILE THERE IS NOTHING GOING ON
ACROSS THE CWA AT THE MOMENT...SHOWERS ARE ALREADY STARTING TO POP
JUST TO OUR NORTH...SO DIDN/T FEEL COMFORTABLE NOT INCLUDING SOME
POSSIBILITY THAT OUR NORTHERN CWA WOULD SEE SOME OF THIS SHOWER
ACTIVITY. STILL THINK THE BEST ACTIVITY WILL DEVELOP ACROSS THE
SOUTHWEST CWA CLOSER TO THE LOCATION OF THE BOUNDARY...SO UPPED
POPS HERE AS WELL TO HIGH END ISOLATED. OVERALL...STILL EXPECT IT
TO BE A VERY HIT AND MISS DAY WITH ONLY LIGHT ACCUMULATIONS
EXPECTED UNDER THE SHOWERS THAT DO DEVELOP. BUT GIVEN THE CURRENT
RADAR WITH SHOWERS POPPING UP AND THE LATEST HI RES
MODELS...WANTED TO GO AHEAD AND INCLUDE EVERYONE IN THE ISOLATED
POTENTIAL.
THAT BEING SAID...THIS UPDATE ALSO INCLUDED AN UPDATE TO THE SKY
COVER...ESPECIALLY FOR THE MORNING HOURS AS HIGH CLOUDS ARE
ALREADY STARTING TO BUILD ACROSS THE AREA. INCREASED CLOUD
COVERAGE THROUGH THE AFTERNOON...BUT CHANGES WERE ONLY
MINOR...WITH FORECAST GROUPS NOW READING PARTLY CLOUDY INSTEAD OF
MOSTLY SUNNY BY THIS AFTERNOON WHEN SOME OF THE DIURNAL CLOUDS
BEGIN DEVELOPING. THIS WAS SUPPORTED BY THE LATEST NAM12 FORECAST
SOUNDINGS...AS WELL AS THE LATEST GFS40 FORECAST SOUNDING...THOUGH
CLOUD LAYERS MAY BE A BIT THINNER ACCORDING TO THE GFS.
FINALLY...ADJUSTED TEMPERATURES FOR TODAY SLIGHTLY. EVEN IF SOME
CLOUD COVER DEVELOPS...DON/T THINK IT WILL HAMPER THE WARM UP TOO
MUCH. AS SUCH...COUNTIES IN THE SW OF THE CWA ARE ALREADY SHOOTING
TO NEAR AND ABOVE 80 DEGREES...AS ARE A FEW IN THE NE CWA. WENT
AHEAD AND BUMPED UP HIGH TEMPERATURES FOR THESE LOCATION A COUPLE
DEGREES HIGHER...TO AROUND 92 INSTEAD OF 90. THIS ALSO MATCHED UP
BETTER WITH THE NEIGHBORING OFFICES WHO HAVE LOW TO MID 90S
FORECAST. WILL CONTINUE TO MONITOR TEMPS THROUGHOUT THE DAY IN
CASE ANY MORE ADJUSTMENTS/UPDATES ARE NEEDED...AS HIGH HUMIDITY
VALUES WILL PLAY A ROLE IN SOME POTENTIALLY PROBLEMATIC HEAT
INDEXES ACROSS THE REGION.
UPDATE ISSUED AT 736 AM EDT SAT JUL 18 2015
LAST OF THE EARLY MORNING SHOWERS HAVE PUSHED OUT OF THE
REGION...WITH DRY WEATHER LIKELY SETTING IN FOR THE REST OF THE
MORNING. HRRR HAS BEEN CONSISTENT ON SHOWING SOME REDEVELOPMENT
ACROSS EASTERN KENTUCKY THROUGH THE MORNING HOURS...BUT HAVE SEEN
NO EVIDENCE OF THIS HAPPENING YET. THUS...WILL MAINTAIN DRY
WEATHER OVER THE NEXT SEVERAL HOURS...BEFORE BRING SOME ISOLATED
SHOWERS/STORMS BACK IN THIS AFTERNOON WITH PEAK HEATING. MAIN AREA
OF FOCUS WILL BE A LEFT OVER OUTFLOW BOUNDARY THAT PUSHES SOUTH
ACROSS SOUTHERN KENTUCKY OVERNIGHT. THIS WILL BEAR WATCHING AS WE
HEAD INTO THE AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 250 AM EDT SAT JUL 18 2015
COMPLEX OF SHOWERS AND STORMS HAS WEAKENED CONSIDERABLY OVER THE
PAST FEW HOURS AS IT PUSHED INTO EASTERN KENTUCKY. BASED ON RADAR
TRENDS...IT LOOKS AS IF THE COMPLEX MIGHT SET UP A BOUNDARY ACROSS
SOUTHERN KENTUCKY...WHICH COULD TRIGGER ADDITIONAL SHOWER/STORMS
THROUGH DAYBREAK. THIS IDEA SEEMS TO BE WHAT THE LATEST HRRR IS
TRYING TO LATCH ONTO. HOWEVER...HI RES MODELS CONTINUE TO PERFORM
POORLY WITH VERY LITTLE CONSISTENCY. THUS...SHOWER/STORM CHANCES
WILL REMAIN LOW GIVEN THE DEGREE OF UNCERTAINTY. IT DOES LOOK LIKE
WE MAY END UP IN A HOLE OF SORTS TODAY...WITH CONVECTION STAYING
EAST/SOUTH/WEST OF THE AREA. THUS...WE COULD MANAGE A DRY DAY.
HOWEVER...WILL MAINTAIN SOME SLIGHT CHANCES GIVEN THE UNCERTAINTY.
BY TONIGHT...INSTABILITY SHOULD WANE AND RIDGE AXIS SHOULD PLANT
ITSELF OVER THE REGION. THUS...LOOKS LIKE A MUCH QUIETER NIGHT
TONIGHT. THE CLEAR SKIES AND LIGHT WINDS COULD YIELD SOME FOG
POTENTIAL IN THE VALLEYS.
ON SUNDAY...STILL NOT MUCH GOING ON WITH THE WEATHER. WE COULD SEE
A FEW SHOWERS OR STORMS POP UP WITH THE DAYTIME HEATING...BUT
SHOULD BE NOTHING WIDESPREAD AND ONLY WARRANTS A SLIGHT CHANCE AT
THIS POINT.
TEMPERATURES WILL REMAIN NEAR GUIDANCE OVER THE NEXT 36
HOURS...WITH HIGHS NEAR 90 WHICH CERTAINLY IS NOT UNCOMMON FOR
THIS TIME OF YEAR. HUMIDITY LEVELS WILL ALSO REMAIN ELEVATED
THROUGH THE WEEKEND...BUT ALSO FAIRLY TYPICAL FOR THIS TIME OF
YEAR. REGARDLESS...WITH THE SPS FOR HEAT ALREADY OUT...WILL JUST
RIDE WITH IT FOR NOW. IT DOES NOT LOOK LIKE WE WILL GET CLOSE TO
HEAT ADVISORY CRITERIA...ESPECIALLY GIVEN THAT TEMPERATURES MAY
NOT OVERACHIEVE GIVEN THE DEGREE OF GROUND SATURATION FROM RECENT
RAINS...WHICH MAY PUT THE CLAMPS ON HIGHS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 313 AM EDT SAT JUL 18 2015
NOT THE BEST OF AGREEMENT AMONGST THE GFS AND ECMWF MODELS THIS GO
ROUND. THE EXTENDED PORTION OF THE FORECAST WAS DERIVED FROM A
SLIGHTLY MODIFIED VERSION OF THE EXTENDED MODEL BLEND DATA. IN
GENERAL...THE FORECAST FOR THE UPCOMING WEEK IS SET TO FEATURE
PERIODS OF SHOWERS AND STORMS...MAINLY DURING THE AFTERNOON AND
EVENING HOURS. THE BEST CHANCE FOR RAIN AT THIS TIME APPEARS TO BE
MONDAY THROUGH TUESDAY...WHEN A FRONTAL BOUNDARY IS FORECAST TO
STALL ACROSS THE AREA. THE FRONT SHOULD FINALLY MAKE A
SOUTHEASTWARD PUSH ACROSS THE AREA TUESDAY NIGHT AND
WEDNESDAY...ALLOWING RAIN CHANCES TO DECREASE ACCORDINGLY. BY
WEDNESDAY MORNING...ONLY ISOLATED SHOWERS AND STORMS SHOULD
LINGER ACROSS EASTERN KENTUCKY. THAT TREND IS EXPECTED TO CONTINUE
THROUGH FRIDAY NIGHT...AS THE FRONT MAY STALL OUT JUST TO OUR
SOUTH...ALLOWING FOR A FEW SHOWERS AND STORMS TO FORM AS MOISTURE
FROM THE GULF OF MEXICO RIDES UP AND OVER THE BOUNDARY.
TEMPERATURES THROUGH OUT THE PERIOD WILL BE WARM AND MUGGY. DAY
TIME HIGHS WILL TOP OUT MOSTLY IN THE MID TO UPPER 80S...WITH A
FEW LOCATIONS PERHAPS BREAKING 90 ON MONDAY. OVERNIGHT LOWS WILL
BOTTOM OUT IN THE UPPER 60S AND LOWER 70S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 736 AM EDT SAT JUL 18 2015
MAINLY VFR CONDITIONS ARE EXPECTED THROUGH TODAY AND MOST OF
TONIGHT. HOWEVER...FOG SHOULD BE A LITTLE MORE ROBUST TONIGHT AS
SKIES HAVE A BETTER CHANCE OF CLEARING. THIS WOULD ALLOW LOCALLY
DENSE VALLEY FOG TO FORM. THE FOG COULD LIFT ONTO THE RIDGES
BEFORE DISSIPATING TOWARDS DAYBREAK SUNDAY. THUS...WILL GO WITH
FOG AT ALL THE TAF SITES FOR LATE TONIGHT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JMW
SHORT TERM...KAS
LONG TERM...AR
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
642 AM CDT SAT JUL 18 2015
.UPDATE...
ISSUED AT 642 AM CDT SAT JUL 18 2015
THE AVIATION SECTION HAS BEEN UPDATED FOR THE 12Z TAF ISSUANCE.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 343 AM CDT SAT JUL 18 2015
THE CONSENSUS OF THE 00Z MODEL CYCLE IS THAT THE UPPER-LEVEL RIDGE
WILL HOLD STRONG ACROSS THE REGION THROUGH THE WEEKEND...AND THEN
IT WILL BE SUPPRESSED TO THE SOUTH/SOUTHWEST ON MONDAY. THE HEAT
ADVISORY LOOKS GOOD FOR TODAY AND SUNDAY. AT THIS TIME...DO NOT
SEE ANYTHING THAT WOULD INDICATE A NEED TO UPGRADE TO A WARNING.
THE MAIN CONCERN IS THE POTENTIAL FOR AT LEAST THE SOUTHERN HALF
OF THE AREA TO NEED A CONTINUATION INTO MONDAY. SINCE THE ENTIRE
AREA HAD 100+ HEAT INDICES YESTERDAY/FRIDAY...MONDAY WOULD BE THE
FOURTH CONSECUTIVE DAY OF 100+ HEAT INDICES WHICH WOULD SUPPORT A
CONTINUATION...EVEN IF ONLY 100-105 IS FORECAST. CONFIDENCE IN THE
MONDAY FORECAST IS QUITE LOW DUE TO A WEAK COLD FRONT AND
ASSOCIATED CONVECTION THAT IS EXPECTED TO BE DRAPED ACROSS THE
REGION. WILL LEAVE THE ADVISORY AS IS FOR NOW. AN UPDATED PRODUCT
WILL BE OUT BY 4 AM.
THE HRRR AND THE NMM AND ARW WRF RUNS ALL DEVELOP SOME ISOLATED TO
WIDELY SCATTERED THUNDERSTORMS OVER ROUGHLY THE EASTERN HALF OF
THE FORECAST AREA FROM MIDDAY TODAY THROUGH THIS AFTERNOON. THIS
WOULD BE DIURNAL ACTIVITY IN A VERY WEAK FLOW REGIME...SO A PULSY
STRONG STORM WILL BE POSSIBLE WITH ISOLATED STRONG WINDS...BUT
ORGANIZED SEVERE WEATHER IS NOT EXPECTED.
POPS WILL BE INCREASING FROM THE NORTH THROUGH THE DAY SUNDAY AND
MUCH OF SUNDAY NIGHT...AS A COLD FRONT APPROACHES THE REGION. THE
CONSENSUS OF 00Z GUIDANCE BRINGS THE FRONT INTO THE AREA IN THE
LATE EVENING AND PUSHES IT THROUGH THE ENTIRE AREA BY 15Z MONDAY.
WILL HAVE POPS UP TO LOW-END LIKELY LEVELS WITH THE FRONT ALONG
THE I-64 CORRIDOR SUNDAY NIGHT. SUNDAY IS LIKELY TO BE DRY...BUT
20-30 POPS ARE FORECAST MAINLY IN THE NORTH JUST TO BE SAFE. POPS
MONDAY WILL BE IN THE CHANCE RANGE DUE TO UNCERTAINTIES IN
FRONTAL LOCATION AND DIURNAL HEATING.
THE FLOW INCREASES SIGNIFICANTLY LATE SUNDAY NIGHT INTO
MONDAY...SO STORMS IN THIS PERIOD WILL LIKELY BE MORE ORGANIZED. A
FEW SEVERE STORMS WITH DAMAGING WINDS WILL BE POSSIBLE. OF COURSE
LOCALLY HEAVY RAINFALL AND FREQUENT LIGHTNING WILL ACCOMPANY ANY
THUNDERSTORMS THROUGH MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 343 AM CDT SAT JUL 18 2015
THIS EXTENDED FORECAST PACKAGE WOULD BE MORE FRUSTRATING TO DEAL
WITH CONSIDERING THE DAY TO DAY VARIATIONS OF THE DETERMINISTIC
GUIDANCE...PARTICULARLY THE GFS DETERMINISTIC MODEL. WITH THIS
PARTICULAR FORECAST PACKAGE...HAD TO FIGHT AGAINST THE EMPHASIS OF
THE DETERMINISTIC GFS GUIDANCE TO RETROGRADE THE SOUTHERN U.S. RIDGE
LATER IN THE WEEK TO ALLOW FOR FASTER AND SLIGHTLY WETTER FLOW AHEAD
OF THE RIDGE.
LOOKING AT THE WESTERN REGION FORECASTER CONFIDENCE TOOLKIT...THE
ENSEMBLE GUIDANCE...EVEN THE GFS ENSEMBLE CONTINUE TO HINT THAT THE
SOUTHERN U.S. RIDGE WILL REMAIN DOMINANT AND WILL NOT RETROGRADE
LATTER IN THE WEEK. CIPS AND OTHER ANALYSIS/ANALOG/ENSEMBLE PLOTS
CONTINUE TO HINT THAT NEXT WEEKEND /JULY 25-26/ WILL BE THE WARMEST
AND DRIEST SO FAR THIS SUMMER. I WOULD NOT BE SURPRISED IF A SPOT OR
TWO IN SOUTHEAST MISSOURI REACHES 98-100...ESPECIALLY BY NEXT
SATURDAY OR SUNDAY.
WITH THE ADJUSTMENT OF THE GRIDDED FORECAST TOWARD THE WARMER AND
DRIER SOLUTION...ADJUSTED DEWPOINTS DOWNWARD 1-2 DEGREES AND LOWERED
OPAQUE CLOUD COVER INTO THE PARTLY CLOUDY CATEGORY VERSUS MOSTLY
CLOUDY. ALL OF THESE CHANGES WILL SUGGEST AND SUPPORT GREATER
EVAPORATION AND INSOLATION...LEADING TO A LONGER DRY SPELL FOR THE
REGION.
FROM A HEAT STANDPOINT...IT LOOKS LIKE NEXT SATURDAY WILL BRING A
RETURN TO A HEAT ADVISORY (OR HIGHER) TO SOUTHEAST MISSOURI...WITH
HEAT INDEX VALUES NEAR 110 WIDESPREAD ON THAT DAY. SUNDAY DOES NOT
LOOK MUCH BETTER.
THERE REMAINS SOME CHALLENGE AS TO THE IMPACT AND COVERAGE OF
PRECIPITATION TUESDAY THROUGH THURSDAY OF NEXT WEEK.
HOWEVER...DEPENDING ON THE INTERPLAY BETWEEN THE RIDGE AND THE FAST
ZONAL FLOW JUST NORTH OF THE RIDGE...THE WFO PAH FORECAST AREA MAY
STILL SEE SOME CONVECTIVE ACTIVITY THROUGH THURSDAY.
&&
.AVIATION...
ISSUED AT 642 AM CDT SAT JUL 18 2015
A FEW CU AND LIGHT SOUTH WINDS WILL BE THE RULE FOR THIS VFR
FORECAST. AN ISOLATED THUNDERSTORM WILL BE POSSIBLE THIS
AFTERNOON MAINLY NEAR KOWB AND POSSIBLY KEVV. WILL ADD TS TO THE
TAFS IF/WHEN IT BECOMES MORE OBVIOUS.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT SUNDAY FOR
ILZ075>078-080>094.
MO...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT SUNDAY FOR
MOZ076-086-087-100-107>112-114.
IN...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT SUNDAY FOR
INZ081-082-085>088.
KY...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT SUNDAY FOR
KYZ001>022.
&&
$$
UPDATE...DRS
SHORT TERM...DRS
LONG TERM...SMITH
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS JACKSON KY
736 AM EDT SAT JUL 18 2015
.UPDATE...
ISSUED AT 736 AM EDT SAT JUL 18 2015
LAST OF THE EARLY MORNING SHOWERS HAVE PUSHED OUT OF THE
REGION...WITH DRY WEATHER LIKELY SETTING IN FOR THE REST OF THE
MORNING. HRRR HAS BEEN CONSISTENT ON SHOWING SOME REDEVELOPMENT
ACROSS EASTERN KENTUCKY THROUGH THE MORNING HOURS...BUT HAVE SEEN
NO EVIDENCE OF THIS HAPPENING YET. THUS...WILL MAINTAIN DRY
WEATHER OVER THE NEXT SEVERAL HOURS...BEFORE BRING SOME ISOLATED
SHOWERS/STORMS BACK IN THIS AFTERNOON WITH PEAK HEATING. MAIN AREA
OF FOCUS WILL BE A LEFT OVER OUTFLOW BOUNDARY THAT PUSHES SOUTH
ACROSS SOUTHERN KENTUCKY OVERNIGHT. THIS WILL BEAR WATCHING AS WE
HEAD INTO THE AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 250 AM EDT SAT JUL 18 2015
COMPLEX OF SHOWERS AND STORMS HAS WEAKENED CONSIDERABLY OVER THE
PAST FEW HOURS AS IT PUSHED INTO EASTERN KENTUCKY. BASED ON RADAR
TRENDS...IT LOOKS AS IF THE COMPLEX MIGHT SET UP A BOUNDARY ACROSS
SOUTHERN KENTUCKY...WHICH COULD TRIGGER ADDITIONAL SHOWER/STORMS
THROUGH DAYBREAK. THIS IDEA SEEMS TO BE WHAT THE LATEST HRRR IS
TRYING TO LATCH ONTO. HOWEVER...HI RES MODELS CONTINUE TO PERFORM
POORLY WITH VERY LITTLE CONSISTENCY. THUS...SHOWER/STORM CHANCES
WILL REMAIN LOW GIVEN THE DEGREE OF UNCERTAINTY. IT DOES LOOK LIKE
WE MAY END UP IN A HOLE OF SORTS TODAY...WITH CONVECTION STAYING
EAST/SOUTH/WEST OF THE AREA. THUS...WE COULD MANAGE A DRY DAY.
HOWEVER...WILL MAINTAIN SOME SLIGHT CHANCES GIVEN THE UNCERTAINTY.
BY TONIGHT...INSTABILITY SHOULD WANE AND RIDGE AXIS SHOULD PLANT
ITSELF OVER THE REGION. THUS...LOOKS LIKE A MUCH QUIETER NIGHT
TONIGHT. THE CLEAR SKIES AND LIGHT WINDS COULD YIELD SOME FOG
POTENTIAL IN THE VALLEYS.
ON SUNDAY...STILL NOT MUCH GOING ON WITH THE WEATHER. WE COULD SEE
A FEW SHOWERS OR STORMS POP UP WITH THE DAYTIME HEATING...BUT
SHOULD BE NOTHING WIDESPREAD AND ONLY WARRANTS A SLIGHT CHANCE AT
THIS POINT.
TEMPERATURES WILL REMAIN NEAR GUIDANCE OVER THE NEXT 36
HOURS...WITH HIGHS NEAR 90 WHICH CERTAINLY IS NOT UNCOMMON FOR
THIS TIME OF YEAR. HUMIDITY LEVELS WILL ALSO REMAIN ELEVATED
THROUGH THE WEEKEND...BUT ALSO FAIRLY TYPICAL FOR THIS TIME OF
YEAR. REGARDLESS...WITH THE SPS FOR HEAT ALREADY OUT...WILL JUST
RIDE WITH IT FOR NOW. IT DOES NOT LOOK LIKE WE WILL GET CLOSE TO
HEAT ADVISORY CRITERIA...ESPECIALLY GIVEN THAT TEMPERATURES MAY
NOT OVERACHIEVE GIVEN THE DEGREE OF GROUND SATURATION FROM RECENT
RAINS...WHICH MAY PUT THE CLAMPS ON HIGHS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 313 AM EDT SAT JUL 18 2015
NOT THE BEST OF AGREEMENT AMONGST THE GFS AND ECMWF MODELS THIS GO
ROUND. THE EXTENDED PORTION OF THE FORECAST WAS DERIVED FROM A
SLIGHTLY MODIFIED VERSION OF THE EXTENDED MODEL BLEND DATA. IN
GENERAL...THE FORECAST FOR THE UPCOMING WEEK IS SET TO FEATURE
PERIODS OF SHOWERS AND STORMS...MAINLY DURING THE AFTERNOON AND
EVENING HOURS. THE BEST CHANCE FOR RAIN AT THIS TIME APPEARS TO BE
MONDAY THROUGH TUESDAY...WHEN A FRONTAL BOUNDARY IS FORECAST TO
STALL ACROSS THE AREA. THE FRONT SHOULD FINALLY MAKE A
SOUTHEASTWARD PUSH ACROSS THE AREA TUESDAY NIGHT AND
WEDNESDAY...ALLOWING RAIN CHANCES TO DECREASE ACCORDINGLY. BY
WEDNESDAY MORNING...ONLY ISOLATED SHOWERS AND STORMS SHOULD
LINGER ACROSS EASTERN KENTUCKY. THAT TREND IS EXPECTED TO CONTINUE
THROUGH FRIDAY NIGHT...AS THE FRONT MAY STALL OUT JUST TO OUR
SOUTH...ALLOWING FOR A FEW SHOWERS AND STORMS TO FORM AS MOISTURE
FROM THE GULF OF MEXICO RIDES UP AND OVER THE BOUNDARY.
TEMPERATURES THROUGH OUT THE PERIOD WILL BE WARM AND MUGGY. DAY
TIME HIGHS WILL TOP OUT MOSTLY IN THE MID TO UPPER 80S...WITH A
FEW LOCATIONS PERHAPS BREAKING 90 ON MONDAY. OVERNIGHT LOWS WILL
BOTTOM OUT IN THE UPPER 60S AND LOWER 70S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 736 AM EDT SAT JUL 18 2015
MAINLY VFR CONDITIONS ARE EXPECTED THROUGH TODAY AND MOST OF
TONIGHT. HOWEVER...FOG SHOULD BE A LITTLE MORE ROBUST TONIGHT AS
SKIES HAVE A BETTER CHANCE OF CLEARING. THIS WOULD ALLOW LOCALLY
DENSE VALLEY FOG TO FORM. THE FOG COULD LIFT ONTO THE RIDGES
BEFORE DISSIPATING TOWARDS DAYBREAK SUNDAY. THUS...WILL GO WITH
FOG AT ALL THE TAF SITES FOR LATE TONIGHT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...KAS
LONG TERM...AR
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
343 AM CDT SAT JUL 18 2015
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 343 AM CDT SAT JUL 18 2015
THE CONSENSUS OF THE 00Z MODEL CYCLE IS THAT THE UPPER-LEVEL RIDGE
WILL HOLD STRONG ACROSS THE REGION THROUGH THE WEEKEND...AND THEN
IT WILL BE SUPPRESSED TO THE SOUTH/SOUTHWEST ON MONDAY. THE HEAT
ADVISORY LOOKS GOOD FOR TODAY AND SUNDAY. AT THIS TIME...DO NOT
SEE ANYTHING THAT WOULD INDICATE A NEED TO UPGRADE TO A WARNING.
THE MAIN CONCERN IS THE POTENTIAL FOR AT LEAST THE SOUTHERN HALF
OF THE AREA TO NEED A CONTINUATION INTO MONDAY. SINCE THE ENTIRE
AREA HAD 100+ HEAT INDICES YESTERDAY/FRIDAY...MONDAY WOULD BE THE
FOURTH CONSECUTIVE DAY OF 100+ HEAT INDICES WHICH WOULD SUPPORT A
CONTINUATION...EVEN IF ONLY 100-105 IS FORECAST. CONFIDENCE IN THE
MONDAY FORECAST IS QUITE LOW DUE TO A WEAK COLD FRONT AND
ASSOCIATED CONVECTION THAT IS EXPECTED TO BE DRAPED ACROSS THE
REGION. WILL LEAVE THE ADVISORY AS IS FOR NOW. AN UPDATED PRODUCT
WILL BE OUT BY 4 AM.
THE HRRR AND THE NMM AND ARW WRF RUNS ALL DEVELOP SOME ISOLATED TO
WIDELY SCATTERED THUNDERSTORMS OVER ROUGHLY THE EASTERN HALF OF
THE FORECAST AREA FROM MIDDAY TODAY THROUGH THIS AFTERNOON. THIS
WOULD BE DIURNAL ACTIVITY IN A VERY WEAK FLOW REGIME...SO A PULSY
STRONG STORM WILL BE POSSIBLE WITH ISOLATED STRONG WINDS...BUT
ORGANIZED SEVERE WEATHER IS NOT EXPECTED.
POPS WILL BE INCREASING FROM THE NORTH THROUGH THE DAY SUNDAY AND
MUCH OF SUNDAY NIGHT...AS A COLD FRONT APPROACHES THE REGION. THE
CONSENSUS OF 00Z GUIDANCE BRINGS THE FRONT INTO THE AREA IN THE
LATE EVENING AND PUSHES IT THROUGH THE ENTIRE AREA BY 15Z MONDAY.
WILL HAVE POPS UP TO LOW-END LIKELY LEVELS WITH THE FRONT ALONG
THE I-64 CORRIDOR SUNDAY NIGHT. SUNDAY IS LIKELY TO BE DRY...BUT
20-30 POPS ARE FORECAST MAINLY IN THE NORTH JUST TO BE SAFE. POPS
MONDAY WILL BE IN THE CHANCE RANGE DUE TO UNCERTAINTIES IN
FRONTAL LOCATION AND DIURNAL HEATING.
THE FLOW INCREASES SIGNIFICANTLY LATE SUNDAY NIGHT INTO
MONDAY...SO STORMS IN THIS PERIOD WILL LIKELY BE MORE ORGANIZED. A
FEW SEVERE STORMS WITH DAMAGING WINDS WILL BE POSSIBLE. OF COURSE
LOCALLY HEAVY RAINFALL AND FREQUENT LIGHTNING WILL ACCOMPANY ANY
THUNDERSTORMS THROUGH MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 343 AM CDT SAT JUL 18 2015
THIS EXTENDED FORECAST PACKAGE WOULD BE MORE FRUSTRATING TO DEAL
WITH CONSIDERING THE DAY TO DAY VARIATIONS OF THE DETERMINISTIC
GUIDANCE...PARTICULARLY THE GFS DETERMINISTIC MODEL. WITH THIS
PARTICULAR FORECAST PACKAGE...HAD TO FIGHT AGAINST THE EMPHASIS OF
THE DETERMINISTIC GFS GUIDANCE TO RETROGRADE THE SOUTHERN U.S. RIDGE
LATER IN THE WEEK TO ALLOW FOR FASTER AND SLIGHTLY WETTER FLOW AHEAD
OF THE RIDGE.
LOOKING AT THE WESTERN REGION FORECASTER CONFIDENCE TOOLKIT...THE
ENSEMBLE GUIDANCE...EVEN THE GFS ENSEMBLE CONTINUE TO HINT THAT THE
SOUTHERN U.S. RIDGE WILL REMAIN DOMINANT AND WILL NOT RETROGRADE
LATTER IN THE WEEK. CIPS AND OTHER ANALYSIS/ANALOG/ENSEMBLE PLOTS
CONTINUE TO HINT THAT NEXT WEEKEND /JULY 25-26/ WILL BE THE WARMEST
AND DRIEST SO FAR THIS SUMMER. I WOULD NOT BE SURPRISED IF A SPOT OR
TWO IN SOUTHEAST MISSOURI REACHES 98-100...ESPECIALLY BY NEXT
SATURDAY OR SUNDAY.
WITH THE ADJUSTMENT OF THE GRIDDED FORECAST TOWARD THE WARMER AND
DRIER SOLUTION...ADJUSTED DEWPOINTS DOWNWARD 1-2 DEGREES AND LOWERED
OPAQUE CLOUD COVER INTO THE PARTLY CLOUDY CATEGORY VERSUS MOSTLY
CLOUDY. ALL OF THESE CHANGES WILL SUGGEST AND SUPPORT GREATER
EVAPORATION AND INSOLATION...LEADING TO A LONGER DRY SPELL FOR THE
REGION.
FROM A HEAT STANDPOINT...IT LOOKS LIKE NEXT SATURDAY WILL BRING A
RETURN TO A HEAT ADVISORY (OR HIGHER) TO SOUTHEAST MISSOURI...WITH
HEAT INDEX VALUES NEAR 110 WIDESPREAD ON THAT DAY. SUNDAY DOES NOT
LOOK MUCH BETTER.
THERE REMAINS SOME CHALLENGE AS TO THE IMPACT AND COVERAGE OF
PRECIPITATION TUESDAY THROUGH THURSDAY OF NEXT WEEK.
HOWEVER...DEPENDING ON THE INTERPLAY BETWEEN THE RIDGE AND THE FAST
ZONAL FLOW JUST NORTH OF THE RIDGE...THE WFO PAH FORECAST AREA MAY
STILL SEE SOME CONVECTIVE ACTIVITY THROUGH THURSDAY.
&&
.AVIATION...
ISSUED AT 615 PM CDT FRI JUL 17 2015
HIGH PRESSURE AT THE SURFACE AND ALOFT WILL PRODUCE DRY CONDITIONS
FOR ALL SITES THROUGH THE PERIOD. ANY CLOUD COVER THAT MAY OCCUR
FROM TIME TO TIME WILL BE VFR. WINDS WILL CONTINUE OUT OF THE SOUTH
SOUTHWEST TO SOUTHWEST GENERALLY AOB 10 KNOTS.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT SUNDAY FOR
ILZ075>078-080>094.
MO...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT SUNDAY FOR
MOZ076-086-087-100-107>112-114.
IN...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT SUNDAY FOR
INZ081-082-085>088.
KY...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT SUNDAY FOR
KYZ001>022.
&&
$$
SHORT TERM...DRS
LONG TERM...SMITH
AVIATION...DB
AREA FORECAST DISCUSSION
NWS JACKSON KY
313 AM EDT SAT JUL 18 2015
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 250 AM EDT SAT JUL 18 2015
COMPLEX OF SHOWERS AND STORMS HAS WEAKENED CONSIDERABLY OVER THE
PAST FEW HOURS AS IT PUSHED INTO EASTERN KENTUCKY. BASED ON RADAR
TRENDS...IT LOOKS AS IF THE COMPLEX MIGHT SET UP A BOUNDARY ACROSS
SOUTHERN KENTUCKY...WHICH COULD TRIGGER ADDITIONAL SHOWER/STORMS
THROUGH DAYBREAK. THIS IDEA SEEMS TO BE WHAT THE LATEST HRRR IS
TRYING TO LATCH ONTO. HOWEVER...HI RES MODELS CONTINUE TO PERFORM
POORLY WITH VERY LITTLE CONSISTENCY. THUS...SHOWER/STORM CHANCES
WILL REMAIN LOW GIVEN THE DEGREE OF UNCERTAINTY. IT DOES LOOK LIKE
WE MAY END UP IN A HOLE OF SORTS TODAY...WITH CONVECTION STAYING
EAST/SOUTH/WEST OF THE AREA. THUS...WE COULD MANAGE A DRY DAY.
HOWEVER...WILL MAINTAIN SOME SLIGHT CHANCES GIVEN THE UNCERTAINTY.
BY TONIGHT...INSTABILITY SHOULD WANE AND RIDGE AXIS SHOULD PLANT
ITSELF OVER THE REGION. THUS...LOOKS LIKE A MUCH QUIETER NIGHT
TONIGHT. THE CLEAR SKIES AND LIGHT WINDS COULD YIELD SOME FOG
POTENTIAL IN THE VALLEYS.
ON SUNDAY...STILL NOT MUCH GOING ON WITH THE WEATHER. WE COULD SEE
A FEW SHOWERS OR STORMS POP UP WITH THE DAYTIME HEATING...BUT
SHOULD BE NOTHING WIDESPREAD AND ONLY WARRANTS A SLIGHT CHANCE AT
THIS POINT.
TEMPERATURES WILL REMAIN NEAR GUIDANCE OVER THE NEXT 36
HOURS...WITH HIGHS NEAR 90 WHICH CERTAINLY IS NOT UNCOMMON FOR
THIS TIME OF YEAR. HUMIDITY LEVELS WILL ALSO REMAIN ELEVATED
THROUGH THE WEEKEND...BUT ALSO FAIRLY TYPICAL FOR THIS TIME OF
YEAR. REGARDLESS...WITH THE SPS FOR HEAT ALREADY OUT...WILL JUST
RIDE WITH IT FOR NOW. IT DOES NOT LOOK LIKE WE WILL GET CLOSE TO
HEAT ADVISORY CRITERIA...ESPECIALLY GIVEN THAT TEMPERATURES MAY
NOT OVERACHIEVE GIVEN THE DEGREE OF GROUND SATURATION FROM RECENT
RAINS...WHICH MAY PUT THE CLAMPS ON HIGHS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 313 AM EDT SAT JUL 18 2015
NOT THE BEST OF AGREEMENT AMONGST THE GFS AND ECMWF MODELS THIS GO
ROUND. THE EXTENDED PORTION OF THE FORECAST WAS DERIVED FROM A
SLIGHTLY MODIFIED VERSION OF THE EXTENDED MODEL BLEND DATA. IN
GENERAL...THE FORECAST FOR THE UPCOMING WEEK IS SET TO FEATURE
PERIODS OF SHOWERS AND STORMS...MAINLY DURING THE AFTERNOON AND
EVENING HOURS. THE BEST CHANCE FOR RAIN AT THIS TIME APPEARS TO BE
MONDAY THROUGH TUESDAY...WHEN A FRONTAL BOUNDARY IS FORECAST TO
STALL ACROSS THE AREA. THE FRONT SHOULD FINALLY MAKE A
SOUTHEASTWARD PUSH ACROSS THE AREA TUESDAY NIGHT AND
WEDNESDAY...ALLOWING RAIN CHANCES TO DECREASE ACCORDINGLY. BY
WEDNESDAY MORNING...ONLY ISOLATED SHOWERS AND STORMS SHOULD
LINGER ACROSS EASTERN KENTUCKY. THAT TREND IS EXPECTED TO CONTINUE
THROUGH FRIDAY NIGHT...AS THE FRONT MAY STALL OUT JUST TO OUR
SOUTH...ALLOWING FOR A FEW SHOWERS AND STORMS TO FORM AS MOISTURE
FROM THE GULF OF MEXICO RIDES UP AND OVER THE BOUNDARY.
TEMPERATURES THROUGH OUT THE PERIOD WILL BE WARM AND MUGGY. DAY
TIME HIGHS WILL TOP OUT MOSTLY IN THE MID TO UPPER 80S...WITH A
FEW LOCATIONS PERHAPS BREAKING 90 ON MONDAY. OVERNIGHT LOWS WILL
BOTTOM OUT IN THE UPPER 60S AND LOWER 70S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 130 AM EDT SAT JUL 18 2015
COMPLEX OF SHOWERS AND STORMS WILL PUSH ON THROUGH OVERNIGHT WITH
SOME SHARP REDUCTIONS IN VISIBILITIES IN THE STRONGER SHOWERS AND
STORMS. IT LOOKS LIKE SHOWERS AND STORMS WILL STAY JUST NORTH OF
KSME AND KLOZ...BUT CLOSE ENOUGH TO LEAVE IN A VCTS.
HOWEVER...KJKL AND KSJS WILL BE IN THE MAIN PATH OF THIS
COMPLEX...SO BEST CHANCES FOR REDUCED VISIBILITIES. WHILE SOME
SHOWERS WILL PERSIST AT KSYM...CONDITIONS SHOULD REMAIN VFR.
SHOWERS AND STORMS WILL MOVE ON OUT BY DAYBREAK...LEAVING BEHIND
VFR CONDITIONS. HOWEVER...THE THREAT OF A ROGUE SHOWER OR STORM
WILL CONTINUE...BUT CONFIDENCE IS LOW ENOUGH TO LEAVE OUT OF THE
TAFS PRESENTLY. WILL HOLD WITH A VFR FORECAST FOR THE DAYLIGHT
PORTION OF THE TAF.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KAS
LONG TERM...AR
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
250 AM EDT SAT JUL 18 2015
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 250 AM EDT SAT JUL 18 2015
COMPLEX OF SHOWERS AND STORMS HAS WEAKENED CONSIDERABLY OVER THE
PAST FEW HOURS AS IT PUSHED INTO EASTERN KENTUCKY. BASED ON RADAR
TRENDS...IT LOOKS AS IF THE COMPLEX MIGHT SET UP A BOUNDARY ACROSS
SOUTHERN KENTUCKY...WHICH COULD TRIGGER ADDITIONAL SHOWER/STORMS
THROUGH DAYBREAK. THIS IDEA SEEMS TO BE WHAT THE LATEST HRRR IS
TRYING TO LATCH ONTO. HOWEVER...HI RES MODELS CONTINUE TO PERFORM
POORLY WITH VERY LITTLE CONSISTENCY. THUS...SHOWER/STORM CHANCES
WILL REMAIN LOW GIVEN THE DEGREE OF UNCERTAINTY. IT DOES LOOK LIKE
WE MAY END UP IN A HOLE OF SORTS TODAY...WITH CONVECTION STAYING
EAST/SOUTH/WEST OF THE AREA. THUS...WE COULD MANAGE A DRY DAY.
HOWEVER...WILL MAINTAIN SOME SLIGHT CHANCES GIVEN THE UNCERTAINTY.
BY TONIGHT...INSTABILITY SHOULD WANE AND RIDGE AXIS SHOULD PLANT
ITSELF OVER THE REGION. THUS...LOOKS LIKE A MUCH QUIETER NIGHT
TONIGHT. THE CLEAR SKIES AND LIGHT WINDS COULD YIELD SOME FOG
POTENTIAL IN THE VALLEYS.
ON SUNDAY...STILL NOT MUCH GOING ON WITH THE WEATHER. WE COULD SEE
A FEW SHOWERS OR STORMS POP UP WITH THE DAYTIME HEATING...BUT
SHOULD BE NOTHING WIDESPREAD AND ONLY WARRANTS A SLIGHT CHANCE AT
THIS POINT.
TEMPERATURES WILL REMAIN NEAR GUIDANCE OVER THE NEXT 36
HOURS...WITH HIGHS NEAR 90 WHICH CERTAINLY IS NOT UNCOMMON FOR
THIS TIME OF YEAR. HUMIDITY LEVELS WILL ALSO REMAIN ELEVATED
THROUGH THE WEEKEND...BUT ALSO FAIRLY TYPICAL FOR THIS TIME OF
YEAR. REGARDLESS...WITH THE SPS FOR HEAT ALREADY OUT...WILL JUST
RIDE WITH IT FOR NOW. IT DOES NOT LOOK LIKE WE WILL GET CLOSE TO
HEAT ADVISORY CRITERIA...ESPECIALLY GIVEN THAT TEMPERATURES MAY
NOT OVERACHIEVE GIVEN THE DEGREE OF GROUND SATURATION FROM RECENT
RAINS...WHICH MAY PUT THE CLAMPS ON HIGHS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 250 AM EDT SAT JUL 18 2015
LONG TERM DISCUSSION WILL FOLLOW SHORTLY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 130 AM EDT SAT JUL 18 2015
COMPLEX OF SHOWERS AND STORMS WILL PUSH ON THROUGH OVERNIGHT WITH
SOME SHARP REDUCTIONS IN VISIBILITIES IN THE STRONGER SHOWERS AND
STORMS. IT LOOKS LIKE SHOWERS AND STORMS WILL STAY JUST NORTH OF
KSME AND KLOZ...BUT CLOSE ENOUGH TO LEAVE IN A VCTS.
HOWEVER...KJKL AND KSJS WILL BE IN THE MAIN PATH OF THIS
COMPLEX...SO BEST CHANCES FOR REDUCED VISIBILITIES. WHILE SOME
SHOWERS WILL PERSIST AT KSYM...CONDITIONS SHOULD REMAIN VFR.
SHOWERS AND STORMS WILL MOVE ON OUT BY DAYBREAK...LEAVING BEHIND
VFR CONDITIONS. HOWEVER...THE THREAT OF A ROGUE SHOWER OR STORM
WILL CONTINUE...BUT CONFIDENCE IS LOW ENOUGH TO LEAVE OUT OF THE
TAFS PRESENTLY. WILL HOLD WITH A VFR FORECAST FOR THE DAYLIGHT
PORTION OF THE TAF.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KAS
LONG TERM...AR
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
354 PM EDT SAT JUL 18 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 326 PM EDT SAT JUL 18 2015
NAM SHOWS A 500 MB TROUGH IN THE NORTHERN PLAINS THIS MORNING THAT
MOVES EAST TODAY AND THROUGH THE AREA TONIGHT.
COMPLICATED FORECAST CONTINUES AS NAM...HRR AND RUC ALL POINT TO NO
REDEVELOPMENT OF CONVECTION THIS AFTERNOON AND EVENING. PROBLEM IS
NONE OF THOSE MODELS ALSO HANDLED THE MCV/QLCS THAT WENT THROUGH
SOUTH OF HERE THIS MORNING EITHER. CANADIAN POINTS TO REDEVELOPMENT
THIS AFTERNOON ALONG WITH GFS AND ECMWF. TO COMPLICATE THINGS
FURTHER...THE 12Z MPX SOUNDING IS FAIRLY DRY AND CAPPED WHILE THE
12Z INL SOUNDING IS UNSTABLE AND MOIST. CONFIDENCE IS LOW THOUGH
WITH THIS FORECAST AND APPEARS THAT THE DRIER AND CAPPED MODEL
SOLUTION SEEMS TO BE VERIFYING AND WILL GO WITH THAT SCENARIO. ONLY
PROBLEM IS THAT IF SOMETHING WOULD GO...IT WOULD GO SEVERE IN A
HURRY AS STRONGER SHEAR AND STRONGER WINDS ARE FORECASTED TO COME IN
LATE THIS AFTERNOON...BUT WITH CAPPED ATMOSPHERE OVER THE
AREA...THINKING IS CUTTING POPS TO SLIGHT CHANCE IS THE WAY TO GO
WITH COLD FRONT COMING THROUGH THIS EVENING AND WILL GO SLIGHT
CHANCE IN CASE SOMETHING IS ABLE TO BREAK THAT CAP. STILL THINK
SMALL HAIL AND WIND GUSTS ARE POSSIBLE
OVERALL...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST FOR
TEMPERATURES. CUT BACK ON THE POPS THIS AFTERNOON AND TONIGHT AND
WENT SLIGHT CHANCE ONLY.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 353 PM EDT SAT JUL 18 2015
SUNDAY NIGHT THROUGH MONDAY NIGHT...AN UPPER LEVEL 500MB CLOSED LOW
AND ASSOCIATED SURFACE LOW WILL REMAIN NEARLY STATIONARY OVER HUDSON
BAY THROUGH THIS TIME PERIOD. THE MAIN IMPACTS FROM THIS WILL COME
FROM A SHORTWAVE AND SURFACE TROUGH/COLD FRONT...STRETCHING
SOUTHWEST INTO NORTHWEST MN SUNDAY NIGHT. THESE FEATURES WILL SLIDE
TO THE EAST...CROSSING THE U.P. BETWEEN 18Z/20 AND 00Z/21. THE VORT
MAX IS PROGGED TO REMAIN OVER LAKE SUPERIOR AND FARTHER NORTH OF
THE U.P. THIS CAN ALSO BE SEEN BY OVERLAYING DEEP LAYER 850MB-300MB
QCONV WITH DEEP LAYER RH. THERE WILL NOT BE A LOT OF MOISTURE TO
WORK WITH LIMITING THE POPS TO SLIGHT CHANCE DURING THIS TIME
PERIOD...AGAIN...THE BEST CHANCES WILL BE MONDAY AFTERNOON INTO THE
EARLY EVENING HOURS...DURING FRONTAL PASSAGE. HIGH TEMPERATURES
MONDAY AFTERNOON WILL WARM INTO THE MID 80S AHEAD OF THE COLD FRONT
AS 850MB TEMPS WARM TO AROUND 18C TO 19C...BEFORE COOLING FROM WEST
TO EAST LATE IN THE AFTERNOON INTO THE EVENING.
TUESDAY THROUGH WEDNESDAY NIGHT...AN ADDITIONAL...VERY WEAK WAVE
WILL SLIDE TO THE NORTH OF THE U.P. LATE MONDAY NIGHT INTO EARLY
TUESDAY MORNING...BUT LITTLE TO NO PRECIP IS EXPECTED FROM THIS
SYSTEM WITH CONTINUED LIMITED MOISTURE AROUND ALONG WITH VERY WEAK
FORCING. ADDITIONALLY...A SURFACE RIDGE WILL BEGIN BUILDING INTO THE
REGION BRINGING ANTICYCLONIC FLOW ALONG WITH EVEN DRYER AIR. THIS
HIGH PRESSURE CENTER WILL CONTINUE TO SLIDE ACROSS THE UPPER GREAT
LAKES REGION TUESDAY AFTERNOON THROUGH WEDNESDAY NIGHT ALLOWING FOR
MAINLY DRY CONDITIONS UNDER A MOSTLY CLEAR TO PARTLY CLOUDY SKY.
850MB TEMPS WILL FALL TO AROUND 12C TO 13C TUESDAY AFTERNOON AND
WEDNESDAY AFTERNOON ALLOWING TEMPERATURES TO COOL BACK TO THE MID
70S...WHICH IS CLOSE TO NORMAL FOR THIS TIME OF YEAR.
THURSDAY THROUGH SATURDAY...MODELS SHOW AN UPPER LEVEL 500MB RIDGE
AXIS SLIDING ACROSS THE UPPER GREAT LAKES REGION THURSDAY INTO
THURSDAY NIGHT IN ADVANCE OF A DEVELOPING LOW PRESSURE SYSTEM AND
ASSOCIATED COLD FRONT...ALLOWING TEMPERATURES TO WARM ONCE AGAIN.
THE COLD FRONT IS EXPECTED TO SLIDE ACROSS THE AREA FRIDAY AFTERNOON
THROUGH SATURDAY BRINGING THE NEXT...WIDESPREAD...CHANCE FOR SHOWERS
AND THUNDERSTORMS. AT THIS POINT DECIDED TO STICK WITH A CONSENSUS
OF THE MODELS DURING THIS TIME PERIOD...WHICH SEEMED REASONABLE WITH
TIMING OF THE FRONT. AS IS USUALLY THE CASE...BEING THIS FAR THERE
WILL LIKELY NEED TO BE ADJUSTMENTS TO TIMING AND INTENSITY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 121 PM EDT SAT JUL 18 2015
VFR CONDITIONS WILL CONTINUE THROUGH THE FORECAST PERIOD. CURRENT
THINKING IS WE WILL STAY CAPPED THIS AFTERNOON AND EVENING WHICH
WOULD PREVENT CONVECTION FROM BREAKING OUT AS A COLD FRONT PASSES
THROUGH THIS EVENING. CONFIDENCE IS LOW THOUGH AS COMPUTER MODELS
DID POORLY WITH COMPLEX THAT WENT TO THE SOUTH OF THE AREA THIS
MORNING AND SOME ARE INDICATING REDEVELOPMENT THIS AFTERNOON AND
SOME ARE DRY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 326 PM EDT SAT JUL 18 2015
ALTHOUGH WINDS WILL BE UNDER 20 KTS INTO TNGT... STRONGER WINDS WILL
BE POSSIBLE IN THUNDERSTORMS TODAY INTO TONIGHT AHEAD OF AN
APPROACHING COLD FRONT AS WATER TEMPS ARE WARMING UP...WHICH WILL
LIMIT LOW-LEVEL STABILITY AND INCREASE THE CHANCE STRONGER WINDS
WILL BE TRANSPORTED TO THE SURFACE. THEN TIGHTENING PRES GRADIENT
BEHIND THE COLD FRONT CROSSING THE LAKE TONIGHT AND BETWEEN HI PRES
MOVING THRU THE NCENTRAL PLAINS AND LO PRES OVER HUDSON BAY WILL
BRING SOME WSW WINDS AS HI AS 25 KTS FROM LATE TONIGHT AND SUN. THE
BEST CHANCE FOR MORE PERSISTENT...STRONGER WINDS WILL BE OVER THE W
AND NCENTRAL PORTIONS BETWEEN ISLE ROYALE AND THE KEWEENAW WHERE
TERRAIN WILL ENHANCE THE LOW LEVEL WINDS. WINDS AFTER SUN NIGHT WILL
DIMINISH TO UNDER 20 KTS AS A RELATIVELY WEAK PRES GRADIENT
DOMINATES NEXT WEEK. RATHER HUMID AIR WILL CAUSE SOME FOG OVER
MAINLY THE COOLER WATERS OF NORTHERN LAKE SUPERIOR THROUGH MON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...KEC
AVIATION...07
MARINE...07
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
326 PM EDT SAT JUL 18 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 326 PM EDT SAT JUL 18 2015
NAM SHOWS A 500 MB TROUGH IN THE NORTHERN PLAINS THIS MORNING THAT
MOVES EAST TODAY AND THROUGH THE AREA TONIGHT.
COMPLICATED FORECAST CONTINUES AS NAM...HRR AND RUC ALL POINT TO NO
REDEVELOPMENT OF CONVECTION THIS AFTERNOON AND EVENING. PROBLEM IS
NONE OF THOSE MODELS ALSO HANDLED THE MCV/QLCS THAT WENT THROUGH
SOUTH OF HERE THIS MORNING EITHER. CANADIAN POINTS TO REDEVELOPMENT
THIS AFTERNOON ALONG WITH GFS AND ECMWF. TO COMPLICATE THINGS
FURTHER...THE 12Z MPX SOUNDING IS FAIRLY DRY AND CAPPED WHILE THE
12Z INL SOUNDING IS UNSTABLE AND MOIST. CONFIDENCE IS LOW THOUGH
WITH THIS FORECAST AND APPEARS THAT THE DRIER AND CAPPED MODEL
SOLUTION SEEMS TO BE VERIFYING AND WILL GO WITH THAT SCENARIO. ONLY
PROBLEM IS THAT IF SOMETHING WOULD GO...IT WOULD GO SEVERE IN A
HURRY AS STRONGER SHEAR AND STRONGER WINDS ARE FORECASTED TO COME IN
LATE THIS AFTERNOON...BUT WITH CAPPED ATMOSPHERE OVER THE
AREA...THINKING IS CUTTING POPS TO SLIGHT CHANCE IS THE WAY TO GO
WITH COLD FRONT COMING THROUGH THIS EVENING AND WILL GO SLIGHT
CHANCE IN CASE SOMETHING IS ABLE TO BREAK THAT CAP. STILL THINK
SMALL HAIL AND WIND GUSTS ARE POSSIBLE
OVERALL...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST FOR
TEMPERATURES. CUT BACK ON THE POPS THIS AFTERNOON AND TONIGHT AND
WENT SLIGHT CHANCE ONLY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 357 AM EDT SAT JUL 18 2015
UPR MI WL BE DOMINATED BY A PROGRESSIVE WNW FLOW ALOFT BTWN UPR RDG
OVER THE SRN CONUS AND SOME TROFFING OVER ERN CANADA FOR MUCH OF THE
COMING MEDIUM/EXTENED FCST PERIOD. TIMING DISTURBANCES MOVING THRU
THIS FLOW AND THEIR IMPACT ON UPR MI WL BE THE PRIMARY FCST CONCERNS.
SUN...ARRIVAL OF LARGER SCALE QVECTOR DVGC/SUBSIDENCE...MID LVL
DRYING AND OVERALL ACYC WNW FLOW BEHIND DEPARTING COLD FROPA...
EXPECT A MOSUNNY DAY. WITH H85 TEMPS FCST TO REACH WITHIN A FEW
DEGREES OF 14C...TEMPS SHOULD TOP OUT IN THE 80 TO 85 RANGE AWAY FM
THE COOLING INFLUENCE OF LK SUP. A STEADY/GUSTY W WIND UNDER FAIRLY
TIGHT PRES GRADIENT TO THE NE OF SFC HI PRES CENTER MOVING TOWARD
THE MID MS RIVER VALLEY WL MAKE THE AIR FEEL A BIT COOLER.
SUN NGT...MODELS INDICATE ANOTHER SHRTWV/SFC LO EMBEDDED IN THE WNW
FLOW ALF WL TRACK THRU NW ONTARIO. SINCE THE BULK OF THE DPVA/LARGER
SCALE FORCING AND DEEP MOISTENING WL STAY TO THE N WITH DRY AIR
LINGERING OVER THE CWA...WL CARRY LO CHC POPS NO FARTHER S THAN NRN
LK SUP. SINCE THE SFC HI PRES CENTER WL BE WELL TO THE S...SHARPER
PRES GRADIENT BTWN THE LO TO THE N/STEADY W FLOW WL TEND TO LIMIT
THE DIURNAL TEMP DROP EVEN THOUGH SKIES WL BE CLR OVER THE S/PCLDY
TO THE N.
MON/MON NGT...FOLLOWING PASSAGE OF ONTARIO SHRTWV/SFC LO TO THE E...
ATTENDANT COLD FNT IS FCST TO MOVE INTO THE FAR NW CWA LATE IN THE
DAY AND THEN CROSS UPR MI ON MON NGT. WITH AN ABSENCE OF ANY SGFNT
MSTR INFLOW...POPS ACCOMPANYING THE FROPA WL BE LIMITED EVEN IF THE
MODELS THAT SHOW A STRONGER TRAILING SHRTWV/POCKET OF SHARPER DEEP
LYR QVECTOR CNVGC CATCHING UP TO THE FNT ARE CORRECT. SINCE THE FNT
WL BE AT LEAST APRCHG THE NW CWA LATE IN THE DAY WHEN DIURNAL
HEATING WL STILL BE A FACTOR...SEEMS LIKE THE BEST SHOT FOR SOME SCT
SHOWERS/TS WL BE IN THAT AREA. COMBINATION OF NEGATIVE H85 THETA E
ADVECTION/LARGER SCALE DRYING AND NOCTURNAL COOLING WL CAUSE ANY
SHOWERS TO DIMINISH OVERNGT. THE WARMEST TEMPS ON MON AFTN WL BE
OVER THE SCNTRL AWAY FM LK MI MODERATION. FCST H85 THERMAL RDG IN
THE 15-17C RANGE WL SUPPORT MAX TEMPS WELL INTO THE 80S.
TUE/WED...MEDIUM RANGE GUIDANCE IS IN GOOD AGREEMENT SHOWING SFC HI
PRES/SOMEWHAT COOLER AIR UNDER NW FLOW ALF TO THE W OF UPR TROF
DEEPENING INTO QUEBEC WL DOMINATE DURING THIS TIME. H85 TEMPS ARE
FCST TO BE ABOUT 11C ON TUE AFTN AND 13-14C ON WED...SUPPORTING HI
TEMPS MAINLY IN THE 70S AWAY FM LK COOLING. WITH PWAT FCST AS LO AS
0.75 INCH AND LIGHT WINDS ON TUE NGT UNDER THE INCOMING HI PRES...
SOME OF THE COOLER INTERIOR SPOTS COULD SEE LO TEMPS DROP INTO THE
40S.
WED NGT THRU FRI...IN GENERAL...THE EXTENDED RANGE GUIDANCE POINT TO
A BLDG UPR RDG OVER CENTRAL NAMERICA EXPANDING INTO THE GREAT LKS AS
TROF IN QUEBEC EDGES SLOWLY TO THE E. SHRTWV FCST TO RIDE THRU THE
UPR MIDWEST TO THE E OF THE BLDG RDG IN THE PLAINS WL SUPPORT SOME
CHC POPS WED NGT THRU THU...BUT MODEL TRENDS TOWARD A WEAKER SHRTWV/
MORE RESILIENT UPR HGTS/HIER MSLP OVER THE CWA SUGGEST PCPN CHCS ARE
LOWER THAN WHAT APPEARED IN PREVIOUS SHIFTS. BLDG HI PRES UNDER THE
ARPCHG RDG SHOULD BRING MAINLY DRY WX FOR FRI.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 121 PM EDT SAT JUL 18 2015
VFR CONDITIONS WILL CONTINUE THROUGH THE FORECAST PERIOD. CURRENT
THINKING IS WE WILL STAY CAPPED THIS AFTERNOON AND EVENING WHICH
WOULD PREVENT CONVECTION FROM BREAKING OUT AS A COLD FRONT PASSES
THROUGH THIS EVENING. CONFIDENCE IS LOW THOUGH AS COMPUTER MODELS
DID POORLY WITH COMPLEX THAT WENT TO THE SOUTH OF THE AREA THIS
MORNING AND SOME ARE INDICATING REDEVELOPMENT THIS AFTERNOON AND
SOME ARE DRY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 326 PM EDT SAT JUL 18 2015
ALTHOUGH WINDS WILL BE UNDER 20 KTS INTO TNGT... STRONGER WINDS WILL
BE POSSIBLE IN THUNDERSTORMS TODAY INTO TONIGHT AHEAD OF AN
APPROACHING COLD FRONT AS WATER TEMPS ARE WARMING UP...WHICH WILL
LIMIT LOW-LEVEL STABILITY AND INCREASE THE CHANCE STRONGER WINDS
WILL BE TRANSPORTED TO THE SURFACE. THEN TIGHTENING PRES GRADIENT
BEHIND THE COLD FRONT CROSSING THE LAKE TONIGHT AND BETWEEN HI PRES
MOVING THRU THE NCENTRAL PLAINS AND LO PRES OVER HUDSON BAY WILL
BRING SOME WSW WINDS AS HI AS 25 KTS FROM LATE TONIGHT AND SUN. THE
BEST CHANCE FOR MORE PERSISTENT...STRONGER WINDS WILL BE OVER THE W
AND NCENTRAL PORTIONS BETWEEN ISLE ROYALE AND THE KEWEENAW WHERE
TERRAIN WILL ENHANCE THE LOW LEVEL WINDS. WINDS AFTER SUN NIGHT WILL
DIMINISH TO UNDER 20 KTS AS A RELATIVELY WEAK PRES GRADIENT
DOMINATES NEXT WEEK. RATHER HUMID AIR WILL CAUSE SOME FOG OVER
MAINLY THE COOLER WATERS OF NORTHERN LAKE SUPERIOR THROUGH MON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...KC
AVIATION...07
MARINE...07
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1107 AM EDT SAT JUL 18 2015
LATEST UPDATE...
MESOSCALE DISCUSSION
.MESOSCALE DISCUSSION...
ISSUED AT 1105 AM EDT SAT JUL 18 2015
A DECREASING LINE OF SHOWERS AND THUNDERSTORMS IS MOVING TO THE
EAST SOUTHEAST AT ABOUT 35 MPH ACROSS CENTRAL LOWER MICHIGAN. THE
LINE CURRENTLY EXTENDS FROM GRATIOT COUNTY TO EATON COUNTY AND ON
TO KALAMAZOO COUNTY. AN AREA OF LIGHT RAIN IS MOVING THROUGH
BEHIND THE LINE OF STORMS.
&&
.SYNOPSIS...
ISSUED AT 329 AM EDT SAT JUL 18 2015
TODAY WILL BE THE HOTTEST DAY OF THE YEAR WITH HIGH
TEMPERATURES IN THE LOWER MID 90S INLAND OF LAKE MICHIGAN AND IT
WILL EASILY BE VERY HUMID. THE COMBINATION OF THESE WILL RESULT
IN SIGNIFICANT HEAT STRESS FOR THOSE OUTSIDE THIS AFTERNOON IN
SOUTHWEST MICHIGAN. THERE IS A GOOD CHANCE OF THUNDERSTORMS
TONIGHT AHEAD OF A COLD FRONT THAT COMES THROUGH SUNDAY MORNING. A
SECOND COLD FRONT WILL BRING YET COOLER AIR FOR THE MIDDLE OF THIS
COMING WEEK.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 329 AM EDT SAT JUL 18 2015
THE PRIMARY QUESTION IS WHAT HAPPENS TO THE MCS CROSSING MINNESOTAINTO
WISCONSIN THIS MORNING? DOES IT REACH LOWER MICHIGAN BY MIDDAY OR
DOES IF DISSIPATE? THEN NEXT QUESTION IS WILL THERE BE
THUNDERSTORMS AHEAD OF THE COLD FRONT TONIGHT? FINALLY WILL THE
TEMPERATURE REALLY MAKE IT IN TO THE LOWER TO MID 90S INLAND OF
LAKE MICHIGAN THIS AFTERNOON?
GIVEN THE SHORTWAVE RIDGING OVER LOWER MICHIGAN TODAY... AND
LOOKING AT MODEL SOUNDING IT WOULD SEEM THE AIR SHOULD BE TO DRY
ALOFT FOR THE UPSTREAM CONVECTION TO REACH LOWER MICHIGAN THIS
AFTERNOON. STILL WE WILL HAVE SURFACE BASE CAPES OVER 2500 J/KG
THIS AFTERNOON SO THE STORMS CAN NOT BE RULED OUT TOTALLY. AS A
RESULT I HAVE LOW CHANCE POPS JUST IN CASE.
THE NAM HAS 1000/925 MB THICKNESS VALUES HIGH ENOUGH FOR HIGHS IN
THE MID 90S. THE ONLY QUESTION IS WILL THERE BE TO MUCH CLOUD
COVER. GIVEN THE SHORTWAVE RIDGING I AM THINKING ANY MCS RELATEDCLOUDS
SHOULD QUICKLY MIX OUT BY MIDDAY.
IT WOULD SEE WE DO HAVE A GOOD SHOT AT THUNDERSTORMS TONIGHT GIVEN
THE COLD FRONT IS COMING THROUGH. PROBLEM IS THE UPPER JET LAGS
BEHIND.
IT WOULD BE MOSTLY SUNNY AND COOLER MONDAY BEHIND THE FRONT WITH
HIGH PRESSURE.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 329 AM EDT SAT JUL 18 2015
A COUPLE OF COLD FRONTS WILL MOVE THROUGH LOWER MICHIGAN NEXT WEEK
WHICH WILL KEEP TEMPERATURES NEAR TO SLIGHTLY BELOW NORMAL; HIGHS
AROUND 80 ARE EXPECTED.
A WEAK COLD FRONT WILL MOVE SOUTH THROUGH THE CWA MONDAY NIGHT BUT
GIVEN THE TIMING AND NW FLOW ALOFT WE DON/T SEE MUCH PCPN DURING
THAT TIME. THEN HIGH PRESSURE BUILDS INTO THE GREAT LAKES FOR A FEW
DAYS RESULTING IN PARTLY CLOUDY SKIES. MUCH LESS HUMIDITY IS
EXPECTED WITH DEWPOINTS IN THE UPPER 50S TOO. THE ECMWF/GFS SHOW A
SHORT WAVE COMING THROUGH THURSDAY/THURSDAY NIGHT IN CONJUNCTION
WITH SOUTH FLOW DEVELOP AND THIS MAY PRODUCE SOME LIGHT PCPN...BUT
CONFIDENCE IS LOW ON THIS HAPPENING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 741 AM EDT SAT JUL 18 2015
THE LINE THUNDERSTORMS OVER WISCONSIN IS HEADING EAST AROUND 40
MPH AND WOULD REACH THE MKG TAF SITE AROUND 1430Z BASED ON OUR
TIMING TOOL. THEY WOULD REACH THE GRAND RAPIDS AROUND 1530Z. USING
THE EXPERIMENTAL VERSION OF THE HRRR (WHICH HAS BEEN DOING VERY
NICELY WITH THE LOCATION AND TIMING OF THESE STORMS ALL NIGHT)
BRINGS THE STORMS INTO SOUTHWEST MICHIGAN AROUND 12Z-13Z THEN
DISPATES THEM TOTALLY BY 15Z. SEEMS THE STORMS WOULD GET TO THE
MKG TAF SITE BEFORE THEY DISIPATE SO I INCLUDED THEM IN THE MKG
TAF.
ONCE THE LINE IS THROUGH SKIES SHOULD BE MOSTLY SUNNY TODAY AS I
EXPECT THE THICK LAYERED CLOUDS FROM THE MCS TO MIX OUT BY LATE
MORNING. A SECOND LINE IS EXPECTED TO FORM LATE THIS AFTERNOON AND
MOVE ONSHORE AROUND 23Z OR SO. I PUT THESE STORMS IN THE TAF
FORECAST TOO AS THE HRRR HAS BEEN CONSISTANT IN FORECASTING THEST
STORM TOO. AFTER THE STORMS MOVE THROUGH I EXPECT VFR CIGS/VSBY
THROUGH SUNDAY MORNING.
&&
.MARINE...
ISSUED AT 329 AM EDT SAT JUL 18 2015
I KEPT THE MARINE DESNE FOG ADVISORY DUE TO THE HIGH DEW POINTS.
WE MAY NEED TO LOOK AT A SMALL CRAFT ADVIOSY SUNDAY FOR WINDS.
&&
.HYDROLOGY...
ISSUED AT 330 PM EDT FRI JUL 17 2015
STREAMFLOWS AT MOST OF OUR RIVER GAUGES ARE RUNNING WELL ABOVE
NORMAL FOR THIS TIME OF YEAR. THUNDERSTORMS THIS WEEKEND MAY PRODUCE
LOCALLY HEAVY RAINFALL... WHICH WOULD LEAD TO SHORT DURATION URBAN
AND LOW LYING AREA FLOODING. A FEW RIVERS COULD RISE OUT OF THEIR
BANKS IF HEAVY RAIN FALLS WITHIN CERTAIN DRAINAGE BASINS. THE MOST
SUSCEPTIBLE RIVERS TO FLOODING WILL BE THE ONES THAT WERE AFFECTED
BY HEAVY RAIN LAST MONTH... GENERALLY THE UPPER PORTION OF THE GRAND
RIVER BASIN (IONIA-LANSING-JACKSON AREAS) AND THE KALAMAZOO BASIN.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR MIZ056>059-064>067-
071>074.
LM...DENSE FOG ADVISORY UNTIL 8 AM EDT SUNDAY FOR LMZ844>849.
&&
$$
MESOSCALE...63
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...04
AVIATION...WDM
HYDROLOGY...CAS
MARINE...WDM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
854 AM EDT SAT JUL 18 2015
LATEST UPDATE...
MESOSCALE DISCUSSION
.MESOSCALE DISCUSSION...
ISSUED AT 853 AM EDT SAT JUL 18 2015
A LINE OF STRONG TO SEVERE THUNDERSTORMS IS CURRENTLY MOVING ON
SHORE JUST NORTH OF MUSKEGON TO NEAR LUDINGTON AT AROUND 45 MPH.
THE LINE IS MOVING INTO MORE STABLE AIR AND I EXPECT THE LINE TO
WEAKEN AS IT MOVES ONSHORE. STILL THE STORMS ARE EXPECTED HAVE
STRONG WIND GUSTS AS THEY MOVE ON SHORE. LOCALLY HEAVY RAIN IS
ALSO EXPECTED.
&&
.SYNOPSIS...
ISSUED AT 329 AM EDT SAT JUL 18 2015
TODAY WILL BE THE HOTTEST DAY OF THE YEAR WITH HIGH
TEMPERATURES IN THE LOWER MID 90S INLAND OF LAKE MICHIGAN AND IT
WILL EASILY BE VERY HUMID. THE COMBINATION OF THESE WILL RESULT
IN SIGNIFICANT HEAT STRESS FOR THOSE OUTSIDE THIS AFTERNOON IN
SOUTHWEST MICHIGAN. THERE IS A GOOD CHANCE OF THUNDERSTORMS
TONIGHT AHEAD OF A COLD FRONT THAT COMES THROUGH SUNDAY MORNING. A
SECOND COLD FRONT WILL BRING YET COOLER AIR FOR THE MIDDLE OF THIS
COMING WEEK.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 329 AM EDT SAT JUL 18 2015
THE PRIMARY QUESTION IS WHAT HAPPENS TO THE MCS CROSSING MINNESOTAINTO
WISCONSIN THIS MORNING? DOES IT REACH LOWER MICHIGAN BY MIDDAY OR
DOES IF DISSIPATE? THEN NEXT QUESTION IS WILL THERE BE
THUNDERSTORMS AHEAD OF THE COLD FRONT TONIGHT? FINALLY WILL THE
TEMPERATURE REALLY MAKE IT IN TO THE LOWER TO MID 90S INLAND OF
LAKE MICHIGAN THIS AFTERNOON?
GIVEN THE SHORTWAVE RIDGING OVER LOWER MICHIGAN TODAY... AND
LOOKING AT MODEL SOUNDING IT WOULD SEEM THE AIR SHOULD BE TO DRY
ALOFT FOR THE UPSTREAM CONVECTION TO REACH LOWER MICHIGAN THIS
AFTERNOON. STILL WE WILL HAVE SURFACE BASE CAPES OVER 2500 J/KG
THIS AFTERNOON SO THE STORMS CAN NOT BE RULED OUT TOTALLY. AS A
RESULT I HAVE LOW CHANCE POPS JUST IN CASE.
THE NAM HAS 1000/925 MB THICKNESS VALUES HIGH ENOUGH FOR HIGHS IN
THE MID 90S. THE ONLY QUESTION IS WILL THERE BE TO MUCH CLOUD
COVER. GIVEN THE SHORTWAVE RIDGING I AM THINKING ANY MCS RELATEDCLOUDS
SHOULD QUICKLY MIX OUT BY MIDDAY.
IT WOULD SEE WE DO HAVE A GOOD SHOT AT THUNDERSTORMS TONIGHT GIVEN
THE COLD FRONT IS COMING THROUGH. PROBLEM IS THE UPPER JET LAGS
BEHIND.
IT WOULD BE MOSTLY SUNNY AND COOLER MONDAY BEHIND THE FRONT WITH
HIGH PRESSURE.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 329 AM EDT SAT JUL 18 2015
A COUPLE OF COLD FRONTS WILL MOVE THROUGH LOWER MICHIGAN NEXT WEEK
WHICH WILL KEEP TEMPERATURES NEAR TO SLIGHTLY BELOW NORMAL; HIGHS
AROUND 80 ARE EXPECTED.
A WEAK COLD FRONT WILL MOVE SOUTH THROUGH THE CWA MONDAY NIGHT BUT
GIVEN THE TIMING AND NW FLOW ALOFT WE DON/T SEE MUCH PCPN DURING
THAT TIME. THEN HIGH PRESSURE BUILDS INTO THE GREAT LAKES FOR A FEW
DAYS RESULTING IN PARTLY CLOUDY SKIES. MUCH LESS HUMIDITY IS
EXPECTED WITH DEWPOINTS IN THE UPPER 50S TOO. THE ECMWF/GFS SHOW A
SHORT WAVE COMING THROUGH THURSDAY/THURSDAY NIGHT IN CONJUNCTION
WITH SOUTH FLOW DEVELOP AND THIS MAY PRODUCE SOME LIGHT PCPN...BUT
CONFIDENCE IS LOW ON THIS HAPPENING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 741 AM EDT SAT JUL 18 2015
THE LINE THUNDERSTORMS OVER WISCONSIN IS HEADING EAST AROUND 40
MPH AND WOULD REACH THE MKG TAF SITE AROUND 1430Z BASED ON OUR
TIMING TOOL. THEY WOULD REACH THE GRAND RAPIDS AROUND 1530Z. USING
THE EXPERIMENTAL VERSION OF THE HRRR (WHICH HAS BEEN DOING VERY
NICELY WITH THE LOCATION AND TIMING OF THESE STORMS ALL NIGHT)
BRINGS THE STORMS INTO SOUTHWEST MICHIGAN AROUND 12Z-13Z THEN
DISPATES THEM TOTALLY BY 15Z. SEEMS THE STORMS WOULD GET TO THE
MKG TAF SITE BEFORE THEY DISIPATE SO I INCLUDED THEM IN THE MKG
TAF.
ONCE THE LINE IS THROUGH SKIES SHOULD BE MOSTLY SUNNY TODAY AS I
EXPECT THE THICK LAYERED CLOUDS FROM THE MCS TO MIX OUT BY LATE
MORNING. A SECOND LINE IS EXPECTED TO FORM LATE THIS AFTERNOON AND
MOVE ONSHORE AROUND 23Z OR SO. I PUT THESE STORMS IN THE TAF
FORECAST TOO AS THE HRRR HAS BEEN CONSISTANT IN FORECASTING THEST
STORM TOO. AFTER THE STORMS MOVE THROUGH I EXPECT VFR CIGS/VSBY
THROUGH SUNDAY MORNING.
&&
.MARINE...
ISSUED AT 329 AM EDT SAT JUL 18 2015
I KEPT THE MARINE DESNE FOG ADVISORY DUE TO THE HIGH DEW POINTS.
WE MAY NEED TO LOOK AT A SMALL CRAFT ADVIOSY SUNDAY FOR WINDS.
&&
.HYDROLOGY...
ISSUED AT 330 PM EDT FRI JUL 17 2015
STREAMFLOWS AT MOST OF OUR RIVER GAUGES ARE RUNNING WELL ABOVE
NORMAL FOR THIS TIME OF YEAR. THUNDERSTORMS THIS WEEKEND MAY PRODUCE
LOCALLY HEAVY RAINFALL... WHICH WOULD LEAD TO SHORT DURATION URBAN
AND LOW LYING AREA FLOODING. A FEW RIVERS COULD RISE OUT OF THEIR
BANKS IF HEAVY RAIN FALLS WITHIN CERTAIN DRAINAGE BASINS. THE MOST
SUSCEPTIBLE RIVERS TO FLOODING WILL BE THE ONES THAT WERE AFFECTED
BY HEAVY RAIN LAST MONTH... GENERALLY THE UPPER PORTION OF THE GRAND
RIVER BASIN (IONIA-LANSING-JACKSON AREAS) AND THE KALAMAZOO BASIN.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...HEAT ADVISORY FROM NOON TODAY TO 9 PM EDT THIS EVENING FOR
MIZ056>059-064>067-071>074.
LM...DENSE FOG ADVISORY UNTIL 8 AM EDT SUNDAY FOR LMZ844>849.
&&
$$
MESOSCALE...WDM
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...04
AVIATION...WDM
HYDROLOGY...CAS
MARINE...WDM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
741 AM EDT SAT JUL 18 2015
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 329 AM EDT SAT JUL 18 2015
TODAY WILL BE THE HOTTEST DAY OF THE YEAR WITH HIGH
TEMPERATURES IN THE LOWER MID 90S INLAND OF LAKE MICHIGAN AND IT
WILL EASILY BE VERY HUMID. THE COMBINATION OF THESE WILL RESULT
IN SIGNIFICANT HEAT STRESS FOR THOSE OUTSIDE THIS AFTERNOON IN
SOUTHWEST MICHIGAN. THERE IS A GOOD CHANCE OF THUNDERSTORMS
TONIGHT AHEAD OF A COLD FRONT THAT COMES THROUGH SUNDAY MORNING. A
SECOND COLD FRONT WILL BRING YET COOLER AIR FOR THE MIDDLE OF THIS
COMING WEEK.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 329 AM EDT SAT JUL 18 2015
THE PRIMARY QUESTION IS WHAT HAPPENS TO THE MCS CROSSING MINNESOTAINTO
WISCONSIN THIS MORNING? DOES IT REACH LOWER MICHIGAN BY MIDDAY OR
DOES IF DISSIPATE? THEN NEXT QUESTION IS WILL THERE BE
THUNDERSTORMS AHEAD OF THE COLD FRONT TONIGHT? FINALLY WILL THE
TEMPERATURE REALLY MAKE IT IN TO THE LOWER TO MID 90S INLAND OF
LAKE MICHIGAN THIS AFTERNOON?
GIVEN THE SHORTWAVE RIDGING OVER LOWER MICHIGAN TODAY... AND
LOOKING AT MODEL SOUNDING IT WOULD SEEM THE AIR SHOULD BE TO DRY
ALOFT FOR THE UPSTREAM CONVECTION TO REACH LOWER MICHIGAN THIS
AFTERNOON. STILL WE WILL HAVE SURFACE BASE CAPES OVER 2500 J/KG
THIS AFTERNOON SO THE STORMS CAN NOT BE RULED OUT TOTALLY. AS A
RESULT I HAVE LOW CHANCE POPS JUST IN CASE.
THE NAM HAS 1000/925 MB THICKNESS VALUES HIGH ENOUGH FOR HIGHS IN
THE MID 90S. THE ONLY QUESTION IS WILL THERE BE TO MUCH CLOUD
COVER. GIVEN THE SHORTWAVE RIDGING I AM THINKING ANY MCS RELATEDCLOUDS
SHOULD QUICKLY MIX OUT BY MIDDAY.
IT WOULD SEE WE DO HAVE A GOOD SHOT AT THUNDERSTORMS TONIGHT GIVEN
THE COLD FRONT IS COMING THROUGH. PROBLEM IS THE UPPER JET LAGS
BEHIND.
IT WOULD BE MOSTLY SUNNY AND COOLER MONDAY BEHIND THE FRONT WITH
HIGH PRESSURE.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 329 AM EDT SAT JUL 18 2015
A COUPLE OF COLD FRONTS WILL MOVE THROUGH LOWER MICHIGAN NEXT WEEK
WHICH WILL KEEP TEMPERATURES NEAR TO SLIGHTLY BELOW NORMAL; HIGHS
AROUND 80 ARE EXPECTED.
A WEAK COLD FRONT WILL MOVE SOUTH THROUGH THE CWA MONDAY NIGHT BUT
GIVEN THE TIMING AND NW FLOW ALOFT WE DON/T SEE MUCH PCPN DURING
THAT TIME. THEN HIGH PRESSURE BUILDS INTO THE GREAT LAKES FOR A FEW
DAYS RESULTING IN PARTLY CLOUDY SKIES. MUCH LESS HUMIDITY IS
EXPECTED WITH DEWPOINTS IN THE UPPER 50S TOO. THE ECMWF/GFS SHOW A
SHORT WAVE COMING THROUGH THURSDAY/THURSDAY NIGHT IN CONJUNCTION
WITH SOUTH FLOW DEVELOP AND THIS MAY PRODUCE SOME LIGHT PCPN...BUT
CONFIDENCE IS LOW ON THIS HAPPENING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 741 AM EDT SAT JUL 18 2015
THE LINE THUNDERSTORMS OVER WISCONSIN IS HEADING EAST AROUND 40
MPH AND WOULD REACH THE MKG TAF SITE AROUND 1430Z BASED ON OUR
TIMING TOOL. THEY WOULD REACH THE GRAND RAPIDS AROUND 1530Z. USING
THE EXPERIMENTAL VERSION OF THE HRRR (WHICH HAS BEEN DOING VERY
NICELY WITH THE LOCATION AND TIMING OF THESE STORMS ALL NIGHT)
BRINGS THE STORMS INTO SOUTHWEST MICHIGAN AROUND 12Z-13Z THEN
DISPATES THEM TOTALLY BY 15Z. SEEMS THE STORMS WOULD GET TO THE
MKG TAF SITE BEFORE THEY DISIPATE SO I INCLUDED THEM IN THE MKG
TAF.
ONCE THE LINE IS THROUGH SKIES SHOULD BE MOSTLY SUNNY TODAY AS I
EXPECT THE THICK LAYERED CLOUDS FROM THE MCS TO MIX OUT BY LATE
MORNING. A SECOND LINE IS EXPECTED TO FORM LATE THIS AFTERNOON AND
MOVE ONSHORE AROUND 23Z OR SO. I PUT THESE STORMS IN THE TAF
FORECAST TOO AS THE HRRR HAS BEEN CONSISTANT IN FORECASTING THEST
STORM TOO. AFTER THE STORMS MOVE THROUGH I EXPECT VFR CIGS/VSBY
THROUGH SUNDAY MORNING.
&&
.MARINE...
ISSUED AT 329 AM EDT SAT JUL 18 2015
I KEPT THE MARINE DESNE FOG ADVISORY DUE TO THE HIGH DEW POINTS.
WE MAY NEED TO LOOK AT A SMALL CRAFT ADVIOSY SUNDAY FOR WINDS.
&&
.HYDROLOGY...
ISSUED AT 330 PM EDT FRI JUL 17 2015
STREAMFLOWS AT MOST OF OUR RIVER GAUGES ARE RUNNING WELL ABOVE
NORMAL FOR THIS TIME OF YEAR. THUNDERSTORMS THIS WEEKEND MAY PRODUCE
LOCALLY HEAVY RAINFALL... WHICH WOULD LEAD TO SHORT DURATION URBAN
AND LOW LYING AREA FLOODING. A FEW RIVERS COULD RISE OUT OF THEIR
BANKS IF HEAVY RAIN FALLS WITHIN CERTAIN DRAINAGE BASINS. THE MOST
SUSCEPTIBLE RIVERS TO FLOODING WILL BE THE ONES THAT WERE AFFECTED
BY HEAVY RAIN LAST MONTH... GENERALLY THE UPPER PORTION OF THE GRAND
RIVER BASIN (IONIA-LANSING-JACKSON AREAS) AND THE KALAMAZOO BASIN.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...HEAT ADVISORY FROM NOON TODAY TO 9 PM EDT THIS EVENING FOR
MIZ056>059-064>067-071>074.
LM...DENSE FOG ADVISORY UNTIL 8 AM EDT SUNDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...04
AVIATION...WDM
HYDROLOGY...CAS
MARINE...WDM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
155 AM EDT SAT JUL 18 2015
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 330 PM EDT FRI JUL 17 2015
A FEW SHOWERS AND STORMS WILL BE POSSIBLE LATE THIS AFTERNOON SOUTH
AND EAST OF INTERSTATE 69. THESE WILL MOVE OUT QUICKLY BY EARLY
EVENING.
HEAT AND HUMIDITY WILL BUILD IN ACROSS THE AREA THROUGH THE DAY ON
SATURDAY. TEMPERATURES ARE EXPECTED TO WARM INTO THE LOWER 90S SOUTH
WHILE HEAT INDICES WILL BE AROUND 100 DEGREES. THERE IS A SLIGHT
CHANCE OF A SHOWER OR STORM SATURDAY. A BETTER CHANCE OF STORMS WILL
COME IN LATER SATURDAY NIGHT AND SUNDAY AS A COLD FRONT PUSHES
THROUGH THE AREA. COOLER AND SOMEWHAT DRIER AIR WILL FILTER IN FOR
THE BEGINNING OF THE WORK WEEK NEXT WEEK.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 330 PM EDT FRI JUL 17 2015
OUR BIGGEST CONCERNS IN THE FCST THROUGH SUN NIGHT ARE THE STORM
CHCS THROUGH THE PERIOD...ALONG WITH THE HEAT POTENTIAL FOR SAT. A
HEAT ADVISORY WILL BE ISSUED WITH THIS FCST PACKAGE FOR THE SRN HALF
OF THE CWFA.
WE HAVE A FEW SHOWERS/STORMS THAT WILL REMAIN POSSIBLE LATE THIS
AFTERNOON MAINLY SOUTH AND EAST OF INTERSTATE 69. WE ARE WATCHING AN
ENHANCED CU FIELD THAT STRETCHES ROUGHLY FROM MIDLAND COUNTY TO EAST
OF SOUTH HAVEN. THIS IS AHEAD OF A WEAK TROUGH DROPPING SOUTHEAST
THROUGH THE AREA ALONG WITH SOME ENHANCEMENT OCCURRING DUE TO THE
WRLY FLOW OFF OF COOLER LAKE MICHIGAN. SOUTH OF THIS LINE...MU CAPES
ARE AROUND 3000 J/KG. DEEP LAYER SHEAR STILL LOOKS TO BE LACKING A
BIT...BUT WE COULD SEE SOME STRONGER PULSE TYPE STORMS POSSIBLE
BEFORE THEY MOVE OUT EARLY THIS EVENING.
THE NEXT LOW CHC OF SOME SHOWERS AND MAYBE A STORM WOULD COME ON SAT
MORNING...ESPECIALLY ACROSS THE WRN HALF OF THE CWFA. A COMPLEX OF
STORMS IS FCST TO DEVELOP/EXPAND ACROSS MN THIS EVENING AHEAD OF A
DEVELOPING LLJ/MOISTURE TRANSPORT THERE. THERE ARE SOME MODELS LIKE
THE HRRR AND NSSL WRF THAT BRING THIS E/SE AFTER DAYBREAK SAT
MORNING. THIS SEEMS PLAUSIBLE WITH DEEP LAYER THICKNESSES EXPECTED
TO BE ORIENTED THIS WAY AND A DEEP LAYER INSTABILITY GRADIENT VERY
SIMILAR. THE LLJ WEAKENS BY THE TIME IT GETS HERE...SO WE EXPECT IT
WOULD BE IN THE DECAYING STAGES IF IT MAKES IT HERE.
ONCE THE DECAYING LINE OF SHOWERS/STORMS IS OUT OF THE PICTURE...THE
HEAT WILL BE THE STORY. ASSUMING THERE IS NOT A PROBLEM WITH
CLEARING CLOUDS OUT SAT MORNING AND SOME POSSIBLE FOG...WE SHOULD
WARM UP QUICKLY AND DEW POINTS WILL REMAIN GENERALLY IN THE LOWER
70S. WE ARE LOOKING AT HEAT INDICES AROUND 100F ROUGHLY OVER THE SRN
HALF OF THE CWFA AWAY FROM THE IMMEDIATE LAKESHORE. WE CAN NOT RULE
OUT A POP UP STORM SAT AFTERNOON WITH A POSSIBLE OUTFLOW BOUNDARY
FLOATING AROUND AND POSSIBLE MU CAPES OF 5000 J/KG. WE LOOK VERY
CAPPED...SO THE CHCS OF A STORM ARE LIMITED TO ABOUT 10-20 PCT.
ANYTHING THAT POPS WOULD HAVE THE POTENTIAL TO BECOME SEVERE WITH
THE EXTREME INSTABILITY AVAILABLE...EVEN WITH WEAK SHEAR VALUES
AROUND 20 KNOTS.
THE BETTER CHC FOR STORMS WILL ROLL IN SAT NIGHT AND THEN MOVE OUT
LATER ON SUN. THE BEST MOISTURE TRANSPORT AND LLJ AHEAD OF THE FRONT
WILL DRIFT IN FROM THE NW SAT NIGHT. THIS WILL BRING SOME HIGHER
CHCS ACROSS THE NW PORTION OF THE AREA. THIS WILL BE ON THE EDGE OF
THE CAP AND WILL FOLLOW THE EDGE OF STRONG INSTABILITY. LARGE HAIL
WILL BE POSSIBLE...AND IT WILL HAVE THE POTENTIAL TO HAVE SOME
DAMAGING WINDS AND BE BETTER ORGANIZED AS A BETTER WIND FIELD ALOFT
MOVES IN. ADDITIONAL STORMS FIRING ALONG THE FRONT WILL HAVE THAT
POTENTIAL THEN ON SUN IF THE FRONT IS STILL IN THE AREA. IF THE
FRONT CLEARS THE CWFA SOONER RATHER THAN LATER ON SUN...THE SEVERE
THREAT WILL BE LOWER.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 330 PM EDT FRI JUL 17 2015
IN GENERAL NEXT WEEK LOOKS VERY SUMMER LIKE WITH HIGHS MAINLY IN THE
LOWER TO MID 80S AND LOWS IN THE MID 50S TO MID 60S. CHANCES FOR
SHOWERS AND THUNDERSTORMS LOOK RELATIVELY LOW.
CONFIDENCE IS HIGH THAT MONDAY WILL BE SUNNY AND LESS HUMID. A WEAK
COLD FRONT IS SHOWN TO DROP SOUTH THROUGH THE STATE ON TUESDAY
ALTHOUGH SOME TIMING DIFFERENCE EXISTS WITH THE ECMWF MUCH QUICKER
THAN THE GFS. EITHER WAY THE COVERAGE OF CONVECTION IS EXPECTED TO
BE LIMITED IN SW LWR MI WITH BETTER POPS IN ERN LWR MI WHERE BETTER
CONVERGENCE IS PROGGED.
HIGH PRESSURE IS EXPECTED TO DOMINATE ON WEDNESDAY AND POSSIBLY INTO
THURSDAY AS WELL. THE ECMWF IS A BIT MORE BULLISH THAN THE GFS WITH
THE RETURN OF WAA RELATED PRECIP...AIDED BY A SHORTWAVE ALOFT...
ALREADY SHOWING QPF ON THURSDAY. THE GFS MEANWHILE WANTS TO HOLD THE
SFC RIDGE AND DRY AIR THROUGH THE END OF THE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 153 AM EDT SAT JUL 18 2015
GIVEN HIGH DEWPOINTS AND LIGHT WIND...WE/LL SEE FOG DEVELOP PRIOR
TO SUNRISE. MVFR VSBYS EXPECTED. ALTHOUGH NOT IN THE TAFS...WE
COULD ALSO SEE SOME PCPN THIS MORNING AS A THUNDERSTORM COMPLEX
OVER MINNESOTA MOVES EAST. THINKING IS THAT IT WILL DISSIPATE
SOMEWHAT AND BE MAINLY NORTH OF THE TAF SITES...BUT NOT DEFINITE
ABOUT THAT. MORE SHOWERS/STORMS POSSIBLE THIS AFTERNOON AND
EVENING AS A COLD FRONT MOVES EAST TOWARD LOWER MICHIGAN.
&&
.MARINE...
ISSUED AT 330 PM EDT FRI JUL 17 2015
WE HAVE EXPANDED THE MARINE DENSE FOG ADVISORY THROUGH SAT NIGHT FOR
THE TIME BEING. VISIBLE SATELLITE IMAGERY THIS AFTERNOON COMBINED
WITH WEB CAMS ALONG THE SHORE SHOW FAIRLY DENSE FOG AT MOST
LOCATIONS. CONDITIONS ARE NOT QUITE AS BAD AT SOUTH HAVEN...BUT IT
HAS EXPANDED SOUTH THIS AFTERNOON AS WINDS HAVE GONE WRLY. EVEN
HIGHER DEW POINTS MOVING IN WITH DIMINISHING WINDS WILL KEEP THE
POTENTIAL HIGH THROUGH AT LEAST SAT NIGHT.
WINDS DO NOT LOOK TO BE A PROBLEM UNTIL AT LEAST SATURDAY NIGHT IF
NOT SUNDAY. A CORE OF WINDS ALOFT AHEAD OF THE INCOMING COLD FRONT
COULD RAMP WINDS UP SAT NIGHT...HOWEVER THIS IS ALWAYS TRICKY WITH
WARMER AIR OVER THE COOLER WATERS.
&&
.HYDROLOGY...
ISSUED AT 330 PM EDT FRI JUL 17 2015
STREAMFLOWS AT MOST OF OUR RIVER GAUGES ARE RUNNING WELL ABOVE
NORMAL FOR THIS TIME OF YEAR. THUNDERSTORMS THIS WEEKEND MAY PRODUCE
LOCALLY HEAVY RAINFALL... WHICH WOULD LEAD TO SHORT DURATION URBAN
AND LOW LYING AREA FLOODING. A FEW RIVERS COULD RISE OUT OF THEIR
BANKS IF HEAVY RAIN FALLS WITHIN CERTAIN DRAINAGE BASINS. THE MOST
SUSCEPTIBLE RIVERS TO FLOODING WILL BE THE ONES THAT WERE AFFECTED
BY HEAVY RAIN LAST MONTH... GENERALLY THE UPPER PORTION OF THE GRAND
RIVER BASIN (IONIA-LANSING-JACKSON AREAS) AND THE KALAMAZOO BASIN.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...HEAT ADVISORY FROM NOON TODAY TO 9 PM EDT THIS EVENING FOR
MIZ056>059-064>067-071>074.
LM...DENSE FOG ADVISORY UNTIL 8 AM EDT SUNDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...MEADE
AVIATION...04
HYDROLOGY...CAS
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS DULUTH MN
955 PM CDT SUN JUL 19 2015
.UPDATE...
ISSUED AT 955 PM CDT SUN JUL 19 2015
SHOWERS ARE DEVELOPING ALONG AND JUST AHEAD OF THE COLD FRONT THAT
HAS REACHED KOOCHICHING AND NORTHERN ST. LOUIS COUNTIES ATTM.
LATEST HRRR HAS SHOWERS CONTINUING TO ACCOMPANY THE FRONT AS IT
PROGRESSES THROUGH THE AREA TONIGHT. HAVE BUMPED UP THE POPS OR
ADDED POPS TO ACCOUNT FOR THIS TREND.
UPDATE ISSUED AT 736 PM CDT SUN JUL 19 2015
A FEW SHOWERS ARE MOVING THROUGH THE BWCAW AHEAD OF A COLD FRONT.
SOME ISOLD THUNDERSTORMS ARE JUST N OF THE CANADIAN BORDER AND MAY
CLIP NORTH CENTRAL INTO NE MN THIS EVENING. INSTABILITY APPEARS TO
DECREASE CONSIDERABLY AFTER 03Z AND JUST HAVE A MENTION OF
SHOWERS. MADE OTHER MINOR TWEAKS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 324 PM CDT SUN JUL 19 2015
THE FOCUS FOR TONIGHT AND MONDAY WILL BE A COLD FRONT THAT WILL
DROP SOUTHWARD ACROSS THE NORTHLAND. AN AREA OF SHOWERS WAS
CURRENTLY MOVING TOWARD LAKE OF THE WOODS OR A BIT NORTH OF THERE.
THE SHOWERS WERE DROPPING TO THE EAST SOUTHEAST AND MAY BRUSH
PORTIONS OF THE INTERNATIONAL BORDER REGION DURING THE EVENING.
SOME MARGINAL INSTABILITY HAD DEVELOPED ACROSS SOUTH CENTRAL
CANADA AND THE BORDER REGION. AS A RESULT...WE COULD SEE SOME
LIMITED SHOWERS AND THUNDERSTORMS OVERNIGHT...MAINLY ACROSS THE
NORTH AND NORTHEAST. COOLER AIR WILL INFILTRATE THE REGION LATER
TONIGHT AND MONDAY...ALTHOUGH TEMPERATURES WILL NOT BE TOO MUCH
COOLER BEHIND THIS FRONT. WILL ALSO CARRY A SMALL POP IN THE FAR
NORTH AND NORTHEAST INTO MONDAY.
GUSTY NORTH TO NORTHWEST WINDS ARE EXPECTED TO DEVELOP ON
MONDAY...AS HIGH PRESSURE PUSHES INTO THE DAKOTAS BEHIND THE
FRONT. TEMPERATURES WILL LARGELY BE IN THE 70S WITH SOME LOWER 80S
IN THE SOUTH/SOUTHEAST.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 324 PM CDT SUN JUL 19 2015
TUESDAY...HIGH PRESSURE WILL MOVE INTO THE UPPER MIDWEST...PROVIDING
THE NORTHLAND WITH CLEAR SKIES. HIGHS SHOULD RANGE BETWEEN THE
MIDDLE 70S TO NEAR 80 DEGREES.
WEDNESDAY AND WEDNESDAY NIGHT...AN UPPER LEVEL RIDGE IN THE NORTHERN
PLAINS WILL BEGIN TO SHIFT INTO THE UPPER MIDWEST...MEANING A WARMER
DAY FOR THE NORTHLAND. A WARM FRONT MIGHT SET UP NEAR THE SOUTHERN
AND WESTERN FORECAST AREA...AND COULD HELP DEVELOP SHOWERS AND
THUNDERSTORMS. THE GEM AND GFS ARE THE MOST AGGRESSIVE WITH PCPN
WITH THE WARM FRONT. HIGHS SHOULD RANGE FROM THE UPPER 70S TO LOW
80S.
THURSDAY...THE UPPER LEVEL RIDGE WILL SHIFT INTO THE UPPER MIDWEST.
THERE ARE LOW CHANCES OF SHOWERS AND STORMS OVER THE NORTHERN AND SE
FORECAST AREA.
FRIDAY...THE GFS/ECMWF/GEM ARE IN FAIRLY GOOD AGREEMENT THAT A
TROUGH WILL MOVE THROUGH THE NORTHLAND AND BRING SHOWERS AND
THUNDERSTORMS. INCREASED PCPN CHANCES BASED ON THE MODEL AGREEMENT.
SATURDAY...HIGH PRESSURE WILL LIKELY MOVE INTO THE PLAINS OR UPPER
MIDWEST IN THE WAKE OF THE TROUGH PASSAGE ON FRIDAY. SATURDAY WILL
LIKELY BE DRY...BUT THERE ARE LOW PCPN CHANCES IN THE FORECAST TO
ACCOUNT FOR THE POTENTIAL THAT THE TROUGH PASSAGE SLOWS DOWN IN
SUBSEQUENT MODEL RUNS. HIGHS WILL LIKELY BE IN THE LOW 80S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 628 PM CDT SUN JUL 19 2015
VFR THROUGH THE FORECAST. A FEW SHOWERS MAY AFFECT INL UNTIL 03Z
BEFORE A COLD FRONT ARRIVES. THE COLD FRONT WILL MOVE PAST ALL
TERMINALS BETWEEN 03Z AND 12Z. WINDS WILL SHIFT FROM SW TO NW
AFTER FROPA. GUSTY SFC WINDS WILL FOLLOW FROPA.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 63 77 57 78 / 70 10 0 0
INL 56 72 51 75 / 90 20 0 0
BRD 63 78 54 81 / 50 0 0 0
HYR 63 81 53 77 / 10 10 0 0
ASX 64 80 57 78 / 90 10 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
UPDATE...GSF
SHORT TERM...DAP
LONG TERM...GROCHOCINSKI
AVIATION...GSF
AREA FORECAST DISCUSSION
NWS DULUTH MN
341 PM CDT SAT JUL 18 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 341 PM CDT SAT JUL 18 2015
CONCERN FOR THE SHORT TERM IS PRECIP CHANCES THIS EVENING.
CURRENT SURFACE ANALYSIS INDICATES THUNDERSTORMS JUST NORTH OF THE
ARROWHEAD IN SOUTHERN CANADA. HRRR INDICATES THERE COULD BE SOME
SPOTTY PRECIP ACROSS THE BORDERLAND THIS EVENING BEHIND THE FRONT
AND A WEAK SHORTWAVE MOVE THROUGH THE REGION. FOR THE REST OF THE
FORECAST AREA THIS AFTERNOON...SKIES WILL STAY PARTLY CLOUDY AS
THE FRONT (IN NW WI AT 20Z) WILL CONTINUE TO MOVE THROUGH THE AREA.
IF ANY PRECIP DEVELOPS...IT WILL BE WIDELY SCATTERED. THE 12Z MPX
SOUNDING WAS CAPPED AND THERE IS NOT MUCH VERTICAL DEVELOPMENT TO
THE CLOUDS AS INDICATED BY OBSERVATION AND SATELLITE. ALL OF THE FORECAST
AREA WILL SEE CLEAR TO PARTLY CLOUDY SKIES LATER THIS EVENING
THROUGH THE OVERNIGHT. WEAK HIGH PRESSURE WILL BUILD INTO THE
REGION LATE TONIGHT AND WILL CAUSE PARTLY TO MOSTLY SUNNY SKIES ON
SUNDAY WITH LESS HUMID CONDITIONS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 341 PM CDT SAT JUL 18 2015
SUNDAY NIGHT...A COLD FRONT WILL MOVE INTO NORTHERN MINNESOTA
SUNDAY EVENING...THEN FINISH MOVING THROUGH THE REST OF THE
NORTHLAND OVERNIGHT INTO MONDAY MORNING. THE
GEM/GFS/ECMWF/NAM/SREF/WRF ARE INDICATING THE POTENTIAL FOR PCPN
OVER THE NORTHERN FORECAST AREA WITH THE PASSAGE OF THE COLD
FRONT. THE GEM IS THE MOST AGGRESSIVE WITH PCPN. THERE COULD BE
ENOUGH INSTABILITY FROM THE DAYTIME HEATING LEFT OVER IN THE
EVENING FOR THE COLD FRONT TO SET OFF SOME SHOWERS. THE THREAT OF
THUNDER LOOKS TO BE VERY LOW. THE NAM12/SREF/GFS INDICATE NEARLY
NO CAPE. IT APPEARS WARM UPPER LEVEL TEMPERATURES WILL LIMIT
MUCAPE FROM GETTING MUCH MORE THAN 100 OR 200 J/KG. LEFT THUNDER
OUT OF THE FORECAST SINCE THE THREAT OF THUNDER SEEMS SO LOW.
MONDAY...SLIGHTLY COOLER AND LESS HUMID WEATHER IS EXPECTED IN THE
NW FLOW PATTERN. THE CONVECTIVE TEMPERATURES SHOULD BE LOW ENOUGH TO
POP SCATTERED/BROKEN CUMULUS BY THE EARLY AFTERNOON FOR MOST AREAS.
HIGH TEMPERATURES SHOULD RANGE FROM THE LOWER 70S OVER THE NORTH TO
NEAR 80 IN NW WISCONSIN. BUMPED UP THE TEMPERATURE FOR PARK POINT
BEACH TO 83 TO ACCOUNT FOR DOWNSLOPE WARMING.
TUESDAY...HIGH PRESSURE WILL MOVE INTO THE UPPER MIDWEST...PROVIDING
THE NORTHLAND WITH A SUNNY AND COMFORTABLE DAY. HIGHS SHOULD BE IN
THE MIDDLE 70S.
WEDNESDAY THROUGH FRIDAY...THE GFS/ECMWF/GEM GENERALLY INDICATE AN
UPPER LEVEL RIDGE WILL SHIFT FROM THE WESTERN PLAINS INTO UPPER
MIDWEST DURING THIS TIMEFRAME. THIS WILL BRING A WARMING TREND
THROUGH FRIDAY...WITH HIGHS BUILDING BACK INTO THE 80S FOR THE LATE
WEEK. THE WARM LOW LEVEL SOUTHERLY FLOW PATTERN WILL CAUSE AFTERNOON
AND EARLY EVENING INSTABILITY FROM DAYTIME HEATING...BUT THERE IS
GENERALLY VERY LOW CHANCES OF SHOWERS AND THUNDERSTORMS IN THE
ABSENCE OF ANY SIGNIFICANT FORCING MECHANISM. THERE ARE SOME SIGNS A
SHORTWAVE TROUGH COULD LIFT THROUGH THE NORTHERN PLAINS OR WESTERN
LAKE SUPERIOR REGION SOMETIME WEDNESDAY NIGHT THROUGH FRIDAY...WHICH
WOULD GIVE A BETTER OPPORTUNITY FOR SHOWER AND STORM
DEVELOPMENT...BUT THE MODELS ARE LACKING AGREEMENT ON ITS TIMING.
THE GFS HAS THE SHORTWAVE TROUGH MOVING THROUGH THURSDAY...THE ECMWF
THURSDAY NIGHT...AND THE GEM NOT UNTIL FRIDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1234 PM CDT SAT JUL 18 2015
CONDITIONS HAVE WAFFLED BETWEEN VFR/MFVR THIS MORNING ACROSS OUR
TAF SITES AS 3KFT CIGS HAVE GONE SCATTERED.... THEN BROKEN... THEN
SCATTERED AGAIN. GENERALLY EXPECTING PREVAILING VFR OVER THE NEXT
24 HOURS... BUT HIGH END MVFR WILL NOT BE OUT OF THE QUESTION IN
THE SHORT TERM AS THE DRY COLD FRONT PASSES THROUGH MINNESOTA
TODAY. EXPECT GUSTY SW WINDS UP TO 30 KTS THIS AFTERNOON...
BECOMING LIGHTER OUT OF THE WEST OVERNIGHT... BUT STILL PERSISTING
AT 5 TO 10 KTS BEFORE BECOMING GUSTY AGAIN TOMORROW AFTER 15Z.
THERE WILL BE A CHANCE OF SCATTERED SHOWERS AS THE FRONT MOVES
THROUGH TODAY... BUT LATEST ANALYSIS FROM THE HRRR KEEPS SHOWER
COVERAGE VERY LOW. DUE TO LOW OVERALL SHOWER CONFIDENCE... REMOVED
MENTION OF VCTS FROM HYR... BUT MAY UPDATE TO ADD IT BACK IF
CONDITIONS CHANGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 60 79 62 79 / 10 0 0 10
INL 55 78 59 72 / 10 10 40 20
BRD 59 82 64 80 / 10 0 0 10
HYR 59 80 63 80 / 10 0 0 10
ASX 60 80 64 79 / 10 0 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
SHORT TERM...STEWART
LONG TERM...GROCHOCINSKI
AVIATION...MCLOVIN
AREA FORECAST DISCUSSION
NWS DULUTH MN
1247 PM CDT SAT JUL 18 2015
.UPDATE...
ISSUED AT 1234 PM CDT SAT JUL 18 2015
UPDATED FOR 18Z AVIATION DISCUSSION BELOW
UPDATE ISSUED AT 1003 AM CDT SAT JUL 18 2015
UPDATED TEMP AND PRECIP POP GRIDS BASED ON LATEST LOOK AT MODELS
AND CURRENT OBS. AT 15Z...COLD FRONT EXTENDED FROM CDD TO AIT TO
LJF. IT SHOULD REACH THE TWIN PORTS AROUND 17Z AND AN ASX-HYR
LINE BY 22Z. SATELLITE WAVE SHOWS CLOUDS AHEAD OF THE FRONT
EXTENDING FROM DLH TO CHG WHICH SHOWS SOME LIFT OCCURRING IN THAT
AREA. THAT LINE WILL BE THE FOCUS OF ANY DEVELOPMENT OF
THUNDERSTORMS. THE 13Z DAY ONE CONVECTIVE OUTLOOK PULLED THE
MARGINALAND SLIGHT RISK INTO SOUTHERN WISCONSIN. SPC INDICATED
THERE WILL NOT BE ANY ORGANIZED SEVERE THUNDERSTORMS BUT THERE
COULD BE AN ISOLATED SVR THUNDERSTORM WITH HAIL AND DAMAGING
WINDS. REST OF FCST UNCHANGED.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 334 AM CDT SAT JUL 18 2015
STRONG MCS EARLY THIS MORNING OVER SOUTHEAST MN/WESTERN WI
CONTINUING TO MOVE EAST...PRODUCING SOME SIGNIFICANT WIND DAMAGE
THERE. THE STRATIFORM RAIN ON THE NORTH SIDE OF THIS MCS IS
AFFECTING MY SOUTHERN CWA...WHICH IS EXPECTED TO CONTINUE TO SLIDE
EAST FOR THE NEXT FEW HOURS...AND HAVE PUT IN SOME HIGH POPS FOR
THIS. THIS IS ALL AHEAD OF A MESO LOW OVER CENTRAL MN...WHICH
SHOULD CONTINUE TO SWEEP EAST AS WELL. ANOTHER AREA OF SHOWERS AND
THUNDERSTORMS HAS DEVELOPED OVER NORTHWEST MINNESOTA... WHICH IS
SLOWLY DRIFTING NORTHEAST INDICATIVE OF ITS ELEVATED NATURE IN A
MID LEVEL CONVERGENCE AND FRONTOGENESIS ZONE. THE MAIN SURFACE LOW
IS STILL OVER SOUTHERN SASKATCHEWAN AND IS ASSOCIATED WITH THE
UPPER LOW ALSO OVER THE REGION. AS THE MAIN SURFACE LOW MOVES EAST
TODAY WE WILL GET ADDITIONAL DEVELOPMENT OF SHOWERS AND
THUNDERSTORMS IN VICINITY OF ANY SURFACE BOUNDARY THE NEXT 12-18
HOURS BEFORE THE MAIN SURFACE LOW AND COLD FRONT SWEEP EAST. UNTIL
THEN...THE MAIN AXIS OF INSTABILITY HAS BEEN ASSOCIATED WITH THE
OVERNIGHT MCS...AND WHILE ANOTHER MAY DEVELOP UP INTO THE CWA THIS
MORNING...IT WILL NOT GET AS UNSTABLE BEFORE BEING SWEPT EAST BY
EARLY AFTERNOON...DESPITE VERY GOOD SHEAR. THUS...SEVERE THREAT
FOR THE CWA IS LOOKING PRETTY MINIMAL...THOUGH IF THE TIMING IS
JUST RIGHT THE SOUTHEAST CORNER IS MOST AT RISK AS DEPICTED IN
THE DAY ONE SPC OUTLOOK. MAX TEMPERATURES TO GET VERY WARM WITH
DEEP MIXING AND A FAIR AMOUNT OF SUNSHINE CONTRIBUTING TO HIGHS
RANGING FROM AROUND 80 AROUND INL...TO THE MID 80S OVER NW WI.
TONIGHT AND SUNDAY GET MUCH QUIETER WITH THE COLD FRONT EAST OF
THE AREA AND WESTERLIES BRINGING IN COOLER AND DRIER AIR. SUNDAY
TO HAVE HIGHS IN THE MID 70S TO LOW 80S.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 334 AM CDT SAT JUL 18 2015
A WEAK COLD FRONT WILL DROP IN FROM THE NORTH LATE SUNDAY NIGHT AND
THROUGH THE DAY MONDAY...PRODUCING ADDITIONAL CLOUD COVER OVER MUCH
OF THE REGION AND A CHANCE OF SHOWERS AND A FEW WEAK THUNDERSTORMS.
THE MOST FAVORABLE AREA TO SEE PRECIPITATION WILL BE ACROSS THE
ARROWHEAD AND INTO NW WI. HIGH PRESSURE AT THE SURFACE AND RIDGING
ALOFT WILL COMBINE WITH DRY AIR MOVING IN TO KEEP CONDITIONS QUIET
MONDAY NIGHT THROUGH TUESDAY NIGHT. THERE WILL BE INCREASING CHANCES
FOR SHOWERS AND STORMS ON WED...BUT CONFIDENCE IS LOW AT THIS TIME
DUE TO DISAGREEMENT AMONG MODEL GUIDANCE. A MORE DOMINANT HIGH
BUILDS IN THURSDAY AND FRIDAY WITH A RETURN TO THE ACTIVE PATTERN BY
THE WEEKEND WITH MORE SHOWERS AND STORMS.
TEMPERATURES WILL STILL BE WARM BUT NOT AS HUMID ON MONDAY WITH
HIGHS TOPPING OUT IN THE LOWER TO MID 80S. NOTICEABLY COOLER
CONDITIONS WILL BE FELT ON TUESDAY...IN THE MID 70S...BUT THROUGH
THE REST OF THE WEEK A GRADUALLY WARMING TREND WILL DEVELOP WITH
HIGHS IN THE LOWER 80S BY FRIDAY. OVERNIGHT LOWS WILL REMAIN MILD IN
THE 50S AND 60S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1234 PM CDT SAT JUL 18 2015
CONDITIONS HAVE WAFFLED BETWEEN VFR/MFVR THIS MORNING ACROSS OUR
TAF SITES AS 3KFT CIGS HAVE GONE SCATTERED.... THEN BROKEN... THEN
SCATTERED AGAIN. GENERALLY EXPECTING PREVAILING VFR OVER THE NEXT
24 HOURS... BUT HIGH END MVFR WILL NOT BE OUT OF THE QUESTION IN
THE SHORT TERM AS THE DRY COLD FRONT PASSES THROUGH MINNESOTA
TODAY. EXPECT GUSTY SW WINDS UP TO 30 KTS THIS AFTERNOON...
BECOMING LIGHTER OUT OF THE WEST OVERNIGHT... BUT STILL PERSISTING
AT 5 TO 10 KTS BEFORE BECOMING GUSTY AGAIN TOMORROW AFTER 15Z.
THERE WILL BE A CHANCE OF SCATTERED SHOWERS AS THE FRONT MOVES
THROUGH TODAY... BUT LATEST ANALYSIS FROM THE HRRR KEEPS SHOWER
COVERAGE VERY LOW. DUE TO LOW OVERALL SHOWER CONFIDENCE... REMOVED
MENTION OF VCTS FROM HYR... BUT MAY UPDATE TO ADD IT BACK IF
CONDITIONS CHANGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 83 60 78 62 / 20 10 0 0
INL 79 55 77 59 / 40 10 10 10
BRD 82 59 80 61 / 10 10 0 0
HYR 84 59 78 60 / 30 10 0 0
ASX 86 60 80 60 / 30 10 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
SHORT TERM...LE
LONG TERM...TENTINGER
AVIATION...MCLOVIN
AREA FORECAST DISCUSSION
NWS DULUTH MN
1230 AM CDT SAT JUL 18 2015
.UPDATE...
ISSUED AT 659 PM CDT FRI JUL 17 2015
HAVE DELAYED THE ONSET OF SHOWERS AND STORMS CLOSER TO MIDNIGHT
OVER THE WESTERN THIRD OF THE FORECAST AREA PER THE LATEST HRRR.
AS SUCH...DELAYED OVER THE REST OF THE REGION TO AFTER MIDNIGHT.
OTHER MINOR ADJUSTMENTS HAVE BEEN MADE.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 248 PM CDT FRI JUL 17 2015
FORECAST FOCUS IN THE SHORT TERM WILL BE ON STORM
CHANCES...STRENGTH...AND POTENTIAL FOR HEAVY RAIN.
A FRONTAL BOUNDARY STRETCHED FROM SOUTHERN MANITOBA THROUGH THE
RED RIVER VALLEY INTO SOUTH DAKOTA AS OF LATE AFTERNOON AND WILL
MOVE EAST OVERNIGHT MOVING INTO CENTRAL MINNESOTA BY 12Z
SATURDAY...THEN JUST CLEARING OUR EASTERN CWA BY 00Z SUN. WATER
VAPOR IMAGERY SHOWED AN UPPER LOW OVER SOUTHERN SK...AND THIS IS
FORECAST TO TRACK ALONG AND JUST NORTH OF THE INTERNATIONAL
BORDER...LAGGING THE FRONT.
SHOWERS/STORMS WILL CONTINUE TO DEVELOP ALONG THE FRONT THIS
AFTERNOON INTO TONIGHT MOVING INTO THE NORTHLAND. THE MODELS WERE
OFFERING VARIOUS SOLUTIONS AS TO HOW FAR EAST THE RAIN WILL MAKE
IT TONIGHT...AND WE BLENDED THE HRRR WITH THE GFS/NAM/ECMWF.
MLCAPE VALUES HAVE BEEN CLIMBING THIS AFTERNOON AND WERE FROM
500 OVER THE ARROWHEAD TO 1500 J/KG ACROSS OUR SOUTHERN ZONES AS
OF THE 19Z SPC MESOANALYSIS. THE HIGHEST CAPE AND NOSE OF THE LLJ
WILL REMAIN SOUTH OF OUR CWA TONIGHT AND THE HRRR SEEMS TO HAVE A
GOOD HANDLE ON DEVELOPING STRONG TO SEVERE STORMS NEAR OR JUST
SOUTH OF OUR CWA THIS EVENING. A STRONG TO SEVERE STORM WILL
REMAIN POSSIBLE OVERNIGHT OVER OUR AREA...BUT CHANCES WILL BE
HIGHEST SOUTH. WE HAVE BEEN QUITE CONCERNED ABOUT ANOTHER ROUND OF
HEAVY RAIN TONIGHT IN AREAS THAT RECEIVED HEAVY RAIN FRIDAY/FRIDAY
EVENING...MAINLY FROM NORTHERN CASS COUNTY NNE TO NORTHERN SAINT
LOUIS COUNTY. PWAT VALUES RISE TO 1.5 TO 1.7 INCHES AGAIN
TONIGHT. WE THOUGHT ABOUT ISSUING A FLASH FLOOD WATCH...BUT IT
DOES NOT APPEAR THAT TRAINING THUNDERSTORMS WILL BE AS BIG A
THREAT AS LAST NIGHT. THE HRRR/NMM/ARW HIGH RES SOLUTIONS SUPPORT
A MORE PROGRESSIVE NATURE TO THE STORMS WITH THE STRONGEST STORMS
SOUTH. WE WILL HAVE TO MONITOR CLOSELY AS 2 TO 4 INCHES OF RAIN
FELL FROM NORTHERN CASS TO KOOCHICHING COUNTIES YESTERDAY INTO THE
EVENING. THE EVENING SHIFT WILL HAVE TO MONITOR STORM
MODE/STRENGTH AND MAY HAVE TO ISSUE HEADLINES IF NEEDED.
SHOWERS/STORMS SHOULD BE ONGOING IN SPOTS SATURDAY MORNING...THEN
MAY WEAKEN OR MOVE OFF LATE MORNING. ADDITIONAL STORMS WILL
DEVELOP ALONG THE FRONT SATURDAY AFTERNOON AND THEY COULD BE
SEVERE...MAINLY OVER PORTIONS OF NORTHWEST WISCONSIN WHERE A MOIST
UNSTABLE AIRMASS WILL BE IN PLACE. DEWPOINTS AHEAD OF THE FRONT
WILL BE FROM 65 TO AROUND 70...THEN DROP BEHIND IT. MOST AREAS
SHOULD RISE INTO THE UPPER 70S TO MID 80S ON SATURDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 248 PM CDT FRI JUL 17 2015
SATURDAY NIGHT...A COLD FRONT WILL FINISH MOVING THROUGH THE
NORTHLAND IN THE LATE EVENING...WHILE AN UPPER LEVEL TROUGH OVER
MANITOBA/ONTARIO LIFTS THROUGH THE REGION. THERE COULD BE LINGERING
SHOWERS AND STORMS IN NW WISCONSIN AND FAR NORTHERN MINNESOTA BEFORE
MIDNIGHT.
SUNDAY...WARMER AIR WILL BEGIN TO FILTER BACK INTO THE NORTHLAND
WITH THE WESTERLY FLOW. THE NAM12 SOUNDINGS INDICATE BREEZY
CONDITIONS DURING THE AFTERNOON AND EARLY EVENING. MOST OF THE
MODELS ARE DRY...BUT THE SREF IS INDICATING LOW PCPN CHANCES...SO
ADDED THE SREF TO THE MODEL BLEND TO GIVE LOW CHANCES OF SHOWERS AND
STORMS OVER NORTHERN MINNESOTA.
MONDAY...THE MODELS ARE NOT IN GOOD AGREEMENT...BUT GENERALLY
INDICATE ANOTHER COLD FRONT WILL MOVE FROM NW TO SE THROUGH THE
FORECAST AREA. THE ECMWF IS ABOUT 12 TO 18 HOURS FASTER THAN THE GFS
AND GEM. THE TIMING OF THE FRONT HAS IMPLICATIONS ON TEMPERATURES
AND PCPN CHANCES. SINCE THE ECMWF FRONT PASSAGE IS DURING THE WEE
HOURS OF MONDAY MORNING...IT DOES NOT HAVE THE INSTABILITY AND PCPN
THAT THE GFS AND GEM ARE INDICATING WITH THE AFTERNOON/EVENING
PASSAGE TIMEFRAME. THE GFS HAS MUCH HOTTER TEMPERATURES FOR
MONDAY...PARTLY SINCE ITS COLD FRONT PASSAGE IS NOT UNTIL MONDAY
NIGHT. USED A BLEND OF THE GFS/GEM/ECMWF/SREF.
TUESDAY...HIGH PRESSURE WILL LIKELY KEEP THE NORTHLAND DRY AND A BIT
COOLER FOR THIS DAY. TEMPERATURES WILL LIKELY BE SEASONAL NORMALS
WITH HIGHS IN THE UPPER 70S.
WEDNESDAY AND THURSDAY...THE MODELS ARE IN POOR AGREEMENT...BUT
GENERALLY SUGGEST A WARM AND HUMID SOUTHERLY LOW LEVEL FLOW PATTERN
SETTING UP DURING THIS TIME. THIS COULD BEGIN TO BRING WARMER AND
UNSTABLE AIR INTO THE REGION. SHOWERS AND THUNDERSTORMS ARE
POSSIBLE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1229 AM CDT SAT JUL 18 2015
THUNDERSTORMS APPEAR TO BE SOUTH OF THE TERMINALS THROUGH THE
FORECAST AND HAVE ADJUSTED ACCORDINGLY. HAVE A MENTION OF LIGHT
RAIN/VCSH HOWEVER AT ALL TERMINALS. LOOKING FOR VFR THROUGH THE
FORECAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 60 81 62 83 / 10 10 0 10
INL 57 78 60 79 / 10 20 10 20
BRD 59 84 62 85 / 0 10 0 10
HYR 60 81 60 83 / 0 10 0 20
ASX 61 81 61 84 / 10 10 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
UPDATE...GSF
SHORT TERM...MELDE
LONG TERM...GROCHOCINSKI
AVIATION...GSF
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
122 PM CDT SAT JUL 18 2015
.UPDATE:
ISSUED AT 112 PM CDT SAT JUL 18 2015
WITH LINGERING CLOUD COVER AND SCATTERED SHOWERS, ISOLATED
THUNDERSTORMS OVER PORTIONS OF THE FORECAST AREA, HAVE CANCELLED
SOME OF THE HEAT ADVISORY. THE ADVISORY HAS BEEN CANCELLED FOR
AREAS ALONG AND NORTH OF A COLUMBIA, MO TO MONTGOMERY CITY, MO TO
PITTSFIELD, IL LINE. OTHERWISE, ADJUSTED HIGH TEMPS FOR EVERYONE
ELSE DOWN A DEGREE OR TWO DUE TO THE CLOUD COVER, BUT STILL EXPECT
HEAT INDICES IN THE 100 TO 109 DEGREE RANGE THIS AFTERNOON.
BYRD
&&
.SHORT TERM: (THROUGH LATE THIS AFTERNOON)
ISSUED AT 410 AM CDT SAT JUL 18 2015
FIRST FORECAST CHALLENGE FOR TODAY IS POPS. SEEING EXPANDING
COVERAGE IN ISOLATED TO WIDELY SCATTERED CONVECTION OVER WEST
CENTRAL/NORTHWEST MISSOURI AT THIS TIME. HRRR SEEMS TO BE HANDLING
THIS WAA PRECIP THE BEST AT THE MOMENT, BUT LATEST RUNS OF THE RAP
DO SEEM TO BE CATCHING UP. FORECAST SOUNDINGS SHOW THE PROVERBIAL
CAP OF FORGED STEEL DEVELOPING...SO SURFACE BASED CONVECTION LOOKS
PRETTY UNLIKELY. MY GUT FEELING IS THAT THE HRRR IS TOO AGGRESSIVE
IN BOTH AREAL COVERAGE AND LONGEVITY IN KEEPING PRECIP GOING THROUGH
LATE MORNING AND EARLY AFTERNOON...AND THE RAP MAY NOT BE AGGRESSIVE
ENOUGH, SO I WENT SOMEWHERE IN BETWEEN INCREASING POPS TO SLIGHT
CHANCE ACROSS CENTRAL AND NORTHEAST MISSOURI INTO WEST CENTRAL
ILLINOIS.
SECOND CHALLENGE IS TEMPERATURES...AND THE HEAT ADVISORY WHICH IS
ALREADY IN EFFECT. OBVIOUSLY, PRECIPITATION AND CLOUD COVER WILL
HAVE A BIG IMPACT ON TEMPERATURES TODAY. IF THE HRRR IS MORE RIGHT
THAN WRONG TODAY, THEN ITS UNLIKELY THAT TEMPERATURES WILL HIT THE
MID AND UPPER 90S AS PER THE CURRENT FORECAST. STUCK WITH THE
WARMER FORECAST AND USED A BLEND OF GUIDANCE FOR HIGHS...LEANING
TOWARD A MIX-DOWN OF 850MB GFS TEMPERATURES. NO CHANGE TO THE HEAT
HEADLINES IS ANTICIPATED AT THIS TIME WITH THE CAVEAT THAT THIS
MORNING`S PRECIP DOESN`T DEVELOP INTO SOMETHING MORE SUBSTANTIAL.
CARNEY
.LONG TERM: (TONIGHT THROUGH FRIDAY)
ISSUED AT 410 AM CDT SAT JUL 18 2015
HEAT REMAINS THE PRIMARY FORECAST CONCERN THRU SUNDAY...AND PERHAPS
INTO MONDAY.
UPPER LEVEL RIDGE DOMINATING THE SOUTHERN CONUS WILL CONTINUE TO
COMMAND A STRONG INFLUENCE INTO OUR REGION INTO SUNDAY...BUT IS
EXPECTED TO BEGIN TO BREAKDOWN A BIT FROM THE NORTH AS THE FIRST IN
A SERIES OF UPPER LEVEL DISTURBANCES PASS THRU. AT THE SURFACE...
THIS WILL EQUATE TO OUR REGION REMAINING IN A S-SW FLOW INTO
SUNDAY...WITH A COLD FRONT DROPPING DOWN MAINLY FROM THE AFTERNOON
HOURS ONWARD. WHILE THIS FRONT IS EXPECTED TO SETTLE ACROSS
SOUTHERN MO AND FAR SOUTHERN IL BY SUNDAY NIGHT...THERE IS
INCREASING EVIDENCE IN THE MODELS THAT THIS FIRST FRONT WILL
DISSOLVE SUNDAY NIGHT WITH A SW FLOW RESUMING ALREADY ON MONDAY IN
TIME FOR ANOTHER FRONT TO DROP DOWN DURING THE AFTERNOON.
REFERENCE SHORT-TERM DISCUSSION ON HEAT FORECAST FOR TODAY.
THE DANGEROUS HEAT AND HUMIDITY IS STILL EXPECTED TO CONTINUE INTO
SUNDAY FOR MUCH OF OUR REGION...ENOUGH TO WARRANT MAINTAINING A HEAT
ADVISORY...ALTHOUGH WITH INCREASING UNCERTAINTY ON ITS NORTHERN
PERIPHERY...AS WHAT LOOKS TO BE A NOCTURNAL CONVECTIVE EVENT WILL
TAKE HOLD FOR LATE TONIGHT AND CARRY INTO SUNDAY MORNING FOR AREAS
MAINLY NORTH OF I-70. THIS WILL BRING WITH IT THE ASSOCIATED DEBRIS
CLOUD THAT WILL PROBABLY LINGER INTO SUNDAY AFTERNOON AND FURTHER
COMPLICATE TEMPS AND HEAT INDEX VALUES WITH A DECENT GRADIENT
SOMEWHERE IN THE VICINITY OF I-70... ALL THE WHILE WITH THE SURFACE
COLD FRONT DROPPING INTO THIS AREA AS WELL DURING THE AFTERNOON.
SOME AREAS MAY EVENTUALLY NEED TO BE LOPPED OFF FROM THE HEAT
ADVISORY BUT THE CONFIDENCE FOR DOING IT THIS PACKAGE IS NOT THERE.
TO FURTHER COMPLICATE THINGS...THE POSSIBLE DISSOLUTION OF THE FRONT
SUNDAY NIGHT AND RETURN OF THE HEAT ALREADY BY MONDAY MAY
NECESSITATE AN EXTENSION OF THE HEAT ADVISORY FOR PARTS OF OUR AREA
INTO MONDAY. BUT AGAIN...THE CONFIDENCE FOR DOING IT WITH THIS
PACKAGE IS SIMPLY NOT THERE AT THIS TIME.
FOCUS THEN SHIFTS TO RAIN CHCS AND SEVERE POTENTIAL FOR EARLY NEXT
WEEK.
THE NOCTURNAL CONVECTIVE EVENT FOR AREAS NORTH OF I-70 WILL HAVE
POTENTIAL FOR SEVERE STORMS PERHAPS ALONG THE FAR NORTHERN CWA FOR A
WINDOW OF TIME THIS EVENING. SEVERE STORM POTENTIAL ON SUNDAY WILL
BE HIGHLY DEPENDENT ON EXACTLY WHAT HAPPENS THE NIGHT BEFORE BUT
ENOUGH INSTABILITY SHOULD BE PRESENT FOR AT LEAST AN ISOLATED SEVERE
STORM THREAT. MORE OR LESS THE SAME ON MONDAY WITH A NEW FRONT AND
SIMILAR INSTABILITY IN PLACE.
THE LINGERING FRONTAL BOUNDARY THRU TUESDAY WILL KEEP RAIN CHANCES
GOING. WE MAY SEE A BRIEF REPRIEVE LATE TUESDAY THRU WEDNESDAY WITH
INFLUENCE OF SURFACE HI PRESSURE BUT A WARM FRONT LATE WEDNESDAY
NIGHT INTO THURSDAY WILL ALLOW FOR THE RETURN OF RAIN CHANCES INTO
THE AREA.
ANOTHER ROUND OF HEAT REMAINS ON TAP FOR PERHAPS AS EARLY AS
THURSDAY AFTERNOON...BUT MODEL CONSENSUS AGREES TO DELAY A DAY INTO
FRIDAY AND NEXT WEEKEND.
TES
&&
.AVIATION: (FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 112 PM CDT SAT JUL 18 2015
DECAYING MCS IS KEEPING MID AND HIGH CLOUDS OVER TAF SITES THIS
AFTERNOON. DID ADD VICINITY SHOWER MENTION TO KUIN AND KCOU
THROUGH 19Z SATURDAY. OTHERWISE, NEXT CHANCE FOR ACTIVITY WILL BE
LATE TONIGHT/EARLY SUNDAY MORNING AS FRONTAL BOUNDARY APPROACHES
REGION. FRONT TO MOVE THROUGH KUIN BY 12Z SUNDAY AND THROUGH I-70
CORRIDOR TAFS BETWEEN 15Z-16Z SUNDAY WITH SOUTH WINDS VEERING TO
THE WEST WITH FRONTAL PASSAGE. MOST SITES JUST HAVE VICINITY
THUNDERSTORM MENTION IN WITH FRONT, THOUGH DID KEEP TEMPO MENTION
FOR KUIN AS THEY REMAIN IN A MORE FAVORABLE REGION FOR STORMS.
SPECIFICS FOR KSTL:
DECAYING MCS IS KEEPING MID AND HIGH CLOUDS OVER TAF SITES THIS
AFTERNOON. NEXT CHANCE FOR ACTIVITY WILL BE LATE TONIGHT/EARLY
SUNDAY MORNING AS FRONTAL BOUNDARY APPROACHES METRO AREA. FRONT
TO MOVE THROUGH METRO AREA BY 16Z SUNDAY WITH SOUTH WINDS VEERING
TO THE WEST WITH FRONTAL PASSAGE. JUST HAVE VICINITY THUNDERSTORM
MENTION IN WITH FRONT FOR NOW AS COVERAGE AND TIMING HARD TO PIN
DOWN.
BYRD
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR COLE MO-CRAWFORD MO-
FRANKLIN MO-GASCONADE MO-IRON MO-JEFFERSON MO-LINCOLN MO-
MADISON MO-MONITEAU MO-OSAGE MO-REYNOLDS MO-ST. CHARLES MO-
ST. FRANCOIS MO-ST. LOUIS CITY MO-ST. LOUIS MO-STE.
GENEVIEVE MO-WARREN MO-WASHINGTON MO.
IL...HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR BOND IL-CALHOUN IL-
CLINTON IL-FAYETTE IL-GREENE IL-JERSEY IL-MACOUPIN IL-
MADISON IL-MARION IL-MONROE IL-MONTGOMERY IL-RANDOLPH IL-
ST. CLAIR IL-WASHINGTON IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
650 AM CDT SAT JUL 18 2015
.SHORT TERM: (THROUGH LATE THIS AFTERNOON)
ISSUED AT 410 AM CDT SAT JUL 18 2015
FIRST FORECAST CHALLENGE FOR TODAY IS POPS. SEEING EXPANDING
COVERAGE IN ISOLATED TO WIDELY SCATTERED CONVECTION OVER WEST
CENTRAL/NORTHWEST MISSOURI AT THIS TIME. HRRR SEEMS TO BE HANDLING
THIS WAA PRECIP THE BEST AT THE MOMENT, BUT LATEST RUNS OF THE RAP
DO SEEM TO BE CATCHING UP. FORECAST SOUNDINGS SHOW THE PROVERBIAL
CAP OF FORGED STEEL DEVELOPING...SO SURFACE BASED CONVECTION LOOKS
PRETTY UNLIKELY. MY GUT FEELING IS THAT THE HRRR IS TOO AGGRESSIVE
IN BOTH AREAL COVERAGE AND LONGEVITY IN KEEPING PRECIP GOING THROUGH
LATE MORNING AND EARLY AFTERNOON...AND THE RAP MAY NOT BE AGGRESSIVE
ENOUGH, SO I WENT SOMEWHERE IN BETWEEN INCREASING POPS TO SLIGHT
CHANCE ACROSS CENTRAL AND NORTHEAST MISSOURI INTO WEST CENTRAL
ILLINOIS.
SECOND CHALLENGE IS TEMPERATURES...AND THE HEAT ADVISORY WHICH IS
ALREADY IN EFFECT. OBVIOUSLY, PRECIPITATION AND CLOUD COVER WILL
HAVE A BIG IMPACT ON TEMPERATURES TODAY. IF THE HRRR IS MORE RIGHT
THAN WRONG TODAY, THEN ITS UNLIKELY THAT TEMPERATURES WILL HIT THE
MID AND UPPER 90S AS PER THE CURRENT FORECAST. STUCK WITH THE
WARMER FORECAST AND USED A BLEND OF GUIDANCE FOR HIGHS...LEANING
TOWARD A MIX-DOWN OF 850MB GFS TEMPERATURES. NO CHANGE TO THE HEAT
HEADLINES IS ANTICIPATED AT THIS TIME WITH THE CAVEAT THAT THIS
MORNING`S PRECIP DOESN`T DEVELOP INTO SOMETHING MORE SUBSTANTIAL.
CARNEY
.LONG TERM: (TONIGHT THROUGH FRIDAY)
ISSUED AT 410 AM CDT SAT JUL 18 2015
HEAT REMAINS THE PRIMARY FORECAST CONCERN THRU SUNDAY...AND PERHAPS
INTO MONDAY.
UPPER LEVEL RIDGE DOMINATING THE SOUTHERN CONUS WILL CONTINUE TO
COMMAND A STRONG INFLUENCE INTO OUR REGION INTO SUNDAY...BUT IS
EXPECTED TO BEGIN TO BREAKDOWN A BIT FROM THE NORTH AS THE FIRST IN
A SERIES OF UPPER LEVEL DISTURBANCES PASS THRU. AT THE SURFACE...
THIS WILL EQUATE TO OUR REGION REMAINING IN A S-SW FLOW INTO
SUNDAY...WITH A COLD FRONT DROPPING DOWN MAINLY FROM THE AFTERNOON
HOURS ONWARD. WHILE THIS FRONT IS EXPECTED TO SETTLE ACROSS
SOUTHERN MO AND FAR SOUTHERN IL BY SUNDAY NIGHT...THERE IS
INCREASING EVIDENCE IN THE MODELS THAT THIS FIRST FRONT WILL
DISSOLVE SUNDAY NIGHT WITH A SW FLOW RESUMING ALREADY ON MONDAY IN
TIME FOR ANOTHER FRONT TO DROP DOWN DURING THE AFTERNOON.
REFERENCE SHORT-TERM DISCUSSION ON HEAT FORECAST FOR TODAY.
THE DANGEROUS HEAT AND HUMIDITY IS STILL EXPECTED TO CONTINUE INTO
SUNDAY FOR MUCH OF OUR REGION...ENOUGH TO WARRANT MAINTAINING A HEAT
ADVISORY...ALTHOUGH WITH INCREASING UNCERTAINTY ON ITS NORTHERN
PERIPHERY...AS WHAT LOOKS TO BE A NOCTURNAL CONVECTIVE EVENT WILL
TAKE HOLD FOR LATE TONIGHT AND CARRY INTO SUNDAY MORNING FOR AREAS
MAINLY NORTH OF I-70. THIS WILL BRING WITH IT THE ASSOCIATED DEBRIS
CLOUD THAT WILL PROBABLY LINGER INTO SUNDAY AFTERNOON AND FURTHER
COMPLICATE TEMPS AND HEAT INDEX VALUES WITH A DECENT GRADIENT
SOMEWHERE IN THE VICINITY OF I-70... ALL THE WHILE WITH THE SURFACE
COLD FRONT DROPPING INTO THIS AREA AS WELL DURING THE AFTERNOON.
SOME AREAS MAY EVENTUALLY NEED TO BE LOPPED OFF FROM THE HEAT
ADVISORY BUT THE CONFIDENCE FOR DOING IT THIS PACKAGE IS NOT THERE.
TO FURTHER COMPLICATE THINGS...THE POSSIBLE DISSOLUTION OF THE FRONT
SUNDAY NIGHT AND RETURN OF THE HEAT ALREADY BY MONDAY MAY
NECESSITATE AN EXTENSION OF THE HEAT ADVISORY FOR PARTS OF OUR AREA
INTO MONDAY. BUT AGAIN...THE CONFIDENCE FOR DOING IT WITH THIS
PACKAGE IS SIMPLY NOT THERE AT THIS TIME.
FOCUS THEN SHIFTS TO RAIN CHCS AND SEVERE POTENTIAL FOR EARLY NEXT
WEEK.
THE NOCTURNAL CONVECTIVE EVENT FOR AREAS NORTH OF I-70 WILL HAVE
POTENTIAL FOR SEVERE STORMS PERHAPS ALONG THE FAR NORTHERN CWA FOR A
WINDOW OF TIME THIS EVENING. SEVERE STORM POTENTIAL ON SUNDAY WILL
BE HIGHLY DEPENDENT ON EXACTLY WHAT HAPPENS THE NIGHT BEFORE BUT
ENOUGH INSTABILITY SHOULD BE PRESENT FOR AT LEAST AN ISOLATED SEVERE
STORM THREAT. MORE OR LESS THE SAME ON MONDAY WITH A NEW FRONT AND
SIMILAR INSTABILITY IN PLACE.
THE LINGERING FRONTAL BOUNDARY THRU TUESDAY WILL KEEP RAIN CHANCES
GOING. WE MAY SEE A BRIEF REPRIEVE LATE TUESDAY THRU WEDNESDAY WITH
INFLUENCE OF SURFACE HI PRESSURE BUT A WARM FRONT LATE WEDNESDAY
NIGHT INTO THURSDAY WILL ALLOW FOR THE RETURN OF RAIN CHANCES INTO
THE AREA.
ANOTHER ROUND OF HEAT REMAINS ON TAP FOR PERHAPS AS EARLY AS
THURSDAY AFTERNOON...BUT MODEL CONSENSUS AGREES TO DELAY A DAY INTO
FRIDAY AND NEXT WEEKEND.
TES
&&
.AVIATION: (FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 630 AM CDT SAT JUL 18 2015
VFR FLIGHT CONDITIONS ARE EXPECTED TO PREVAIL TODAY ACROSS THE
AREA. SCATTERED SHOWERS AND POSSIBLY A FEW THUNDERSTORMS WILL
CONTINUE TO MOVE EAST INTO CENTRAL AND NORTHEAST MISSOURI THIS
MORNING. LATEST THINKING IS THAT THE HEAVIEST PRECIP WILL STAY
WELL WEST OF THE AREA TODAY...AND THAT THE MAJORITY OF THE RAIN
SHOULD DISSIPATE THROUGH THE LATE MORNING AND EARLY AFTERNOON.
THERE WILL BE A BETTER CHANCE OF STORMS ACROSS NORTHERN PORTIONS
OF THE AREA THIS EVENING AND OVERNIGHT AHEAD OF AN APPROACHING
COLD FRONT. VFR FLIGHT CONDITIONS ARE EXPECTED TO PREVAIL OUTSIDE
OF THE STORMS.
SPECIFICS FOR KSTL:
EXPECT VFR FLIGHT CONDITIONS TO PREVAIL TODAY AND INTO TONIGHT AT
LAMBERT. SHOWERS OVER WESTERN/CENTRAL MISSOURI SHOULD DISSIPATE
BEFORE REACHING THE TERMINAL; BUT I CAN`T TOTALLY RULE OUT A STRAY
SHOWER OR THUNDERSTORM. WIND WILL SHIFT FROM A WEST-SOUTHWEST TO A
SOUTHERLY DIRECTION TODAY, UNFORTUNATELY THIS MEANS THE WIND WILL
PROBABLY BE VERY NEARLY A DIRECT CTOSSWIND FOR THE MAIN RUNWAYS
DURING SOME PERIOD THIS AFTERNOON. THINK LAMBERT WILL BE FAR
ENOUGH SOUTH TO AVOID ANY STORMS TONIGHT, BUT THE CHANCES FOR
STORMS WILL INCREASE AFTER 12Z SUNDAY MORNING.
CARNEY
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...HEAT ADVISORY FROM NOON TODAY TO 8 PM CDT SUNDAY FOR CRAWFORD MO-
IRON MO-MADISON MO-REYNOLDS MO-ST. FRANCOIS MO-STE.
GENEVIEVE MO-WASHINGTON MO.
HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR AUDRAIN MO-BOONE MO-
CALLAWAY MO-COLE MO-FRANKLIN MO-GASCONADE MO-JEFFERSON MO-
LINCOLN MO-MONITEAU MO-MONTGOMERY MO-OSAGE MO-ST. CHARLES
MO-ST. LOUIS CITY MO-ST. LOUIS MO-WARREN MO.
HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR KNOX MO-LEWIS MO-
MARION MO-MONROE MO-PIKE MO-RALLS MO-SHELBY MO.
IL...HEAT ADVISORY FROM NOON TODAY TO 8 PM CDT SUNDAY FOR BOND IL-
CLINTON IL-FAYETTE IL-MARION IL-MONTGOMERY IL-RANDOLPH IL-
WASHINGTON IL.
HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR CALHOUN IL-GREENE IL-
JERSEY IL-MACOUPIN IL-MADISON IL-MONROE IL-ST. CLAIR IL.
HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR ADAMS IL-BROWN IL-
PIKE IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
410 AM CDT SAT JUL 18 2015
.SHORT TERM: (THROUGH LATE THIS AFTERNOON)
ISSUED AT 410 AM CDT SAT JUL 18 2015
FIRST FORECAST CHALLENGE FOR TODAY IS POPS. SEEING EXPANDING
COVERAGE IN ISOLATED TO WIDELY SCATTERED CONVECTION OVER WEST
CENTRAL/NORTHWEST MISSOURI AT THIS TIME. HRRR SEEMS TO BE HANDLING
THIS WAA PRECIP THE BEST AT THE MOMENT, BUT LATEST RUNS OF THE RAP
DO SEEM TO BE CATCHING UP. FORECAST SOUNDINGS SHOW THE PROVERBIAL
CAP OF FORGED STEEL DEVELOPING...SO SURFACE BASED CONVECTION LOOKS
PRETTY UNLIKELY. MY GUT FEELING IS THAT THE HRRR IS TOO AGGRESSIVE
IN BOTH AREAL COVERAGE AND LONGEVITY IN KEEPING PRECIP GOING THROUGH
LATE MORNING AND EARLY AFTERNOON...AND THE RAP MAY NOT BE AGGRESSIVE
ENOUGH, SO I WENT SOMEWHERE IN BETWEEN INCREASING POPS TO SLIGHT
CHANCE ACROSS CENTRAL AND NORTHEAST MISSOURI INTO WEST CENTRAL
ILLINOIS.
SECOND CHALLENGE IS TEMPERATURES...AND THE HEAT ADVISORY WHICH IS
ALREADY IN EFFECT. OBVIOUSLY, PRECIPITATION AND CLOUD COVER WILL
HAVE A BIG IMPACT ON TEMPERATURES TODAY. IF THE HRRR IS MORE RIGHT
THAN WRONG TODAY, THEN ITS UNLIKELY THAT TEMPERATURES WILL HIT THE
MID AND UPPER 90S AS PER THE CURRENT FORECAST. STUCK WITH THE
WARMER FORECAST AND USED A BLEND OF GUIDANCE FOR HIGHS...LEANING
TOWARD A MIX-DOWN OF 850MB GFS TEMPERATURES. NO CHANGE TO THE HEAT
HEADLINES IS ANTICIPATED AT THIS TIME WITH THE CAVEAT THAT THIS
MORNING`S PRECIP DOESN`T DEVELOP INTO SOMETHING MORE SUBSTANTIAL.
CARNEY
.LONG TERM: (TONIGHT THROUGH FRIDAY)
ISSUED AT 410 AM CDT SAT JUL 18 2015
HEAT REMAINS THE PRIMARY FORECAST CONCERN THRU SUNDAY...AND PERHAPS
INTO MONDAY.
UPPER LEVEL RIDGE DOMINATING THE SOUTHERN CONUS WILL CONTINUE TO
COMMAND A STRONG INFLUENCE INTO OUR REGION INTO SUNDAY...BUT IS
EXPECTED TO BEGIN TO BREAKDOWN A BIT FROM THE NORTH AS THE FIRST IN
A SERIES OF UPPER LEVEL DISTURBANCES PASS THRU. AT THE SURFACE...
THIS WILL EQUATE TO OUR REGION REMAINING IN A S-SW FLOW INTO
SUNDAY...WITH A COLD FRONT DROPPING DOWN MAINLY FROM THE AFTERNOON
HOURS ONWARD. WHILE THIS FRONT IS EXPECTED TO SETTLE ACROSS
SOUTHERN MO AND FAR SOUTHERN IL BY SUNDAY NIGHT...THERE IS
INCREASING EVIDENCE IN THE MODELS THAT THIS FIRST FRONT WILL
DISSOLVE SUNDAY NIGHT WITH A SW FLOW RESUMING ALREADY ON MONDAY IN
TIME FOR ANOTHER FRONT TO DROP DOWN DURING THE AFTERNOON.
REFERENCE SHORT-TERM DISCUSSION ON HEAT FORECAST FOR TODAY.
THE DANGEROUS HEAT AND HUMIDITY IS STILL EXPECTED TO CONTINUE INTO
SUNDAY FOR MUCH OF OUR REGION...ENOUGH TO WARRANT MAINTAINING A HEAT
ADVISORY...ALTHOUGH WITH INCREASING UNCERTAINTY ON ITS NORTHERN
PERIPHERY...AS WHAT LOOKS TO BE A NOCTURNAL CONVECTIVE EVENT WILL
TAKE HOLD FOR LATE TONIGHT AND CARRY INTO SUNDAY MORNING FOR AREAS
MAINLY NORTH OF I-70. THIS WILL BRING WITH IT THE ASSOCIATED DEBRIS
CLOUD THAT WILL PROBABLY LINGER INTO SUNDAY AFTERNOON AND FURTHER
COMPLICATE TEMPS AND HEAT INDEX VALUES WITH A DECENT GRADIENT
SOMEWHERE IN THE VICINITY OF I-70... ALL THE WHILE WITH THE SURFACE
COLD FRONT DROPPING INTO THIS AREA AS WELL DURING THE AFTERNOON.
SOME AREAS MAY EVENTUALLY NEED TO BE LOPPED OFF FROM THE HEAT
ADVISORY BUT THE CONFIDENCE FOR DOING IT THIS PACKAGE IS NOT THERE.
TO FURTHER COMPLICATE THINGS...THE POSSIBLE DISSOLUTION OF THE FRONT
SUNDAY NIGHT AND RETURN OF THE HEAT ALREADY BY MONDAY MAY
NECESSITATE AN EXTENSION OF THE HEAT ADVISORY FOR PARTS OF OUR AREA
INTO MONDAY. BUT AGAIN...THE CONFIDENCE FOR DOING IT WITH THIS
PACKAGE IS SIMPLY NOT THERE AT THIS TIME.
FOCUS THEN SHIFTS TO RAIN CHCS AND SEVERE POTENTIAL FOR EARLY NEXT
WEEK.
THE NOCTURNAL CONVECTIVE EVENT FOR AREAS NORTH OF I-70 WILL HAVE
POTENTIAL FOR SEVERE STORMS PERHAPS ALONG THE FAR NORTHERN CWA FOR A
WINDOW OF TIME THIS EVENING. SEVERE STORM POTENTIAL ON SUNDAY WILL
BE HIGHLY DEPENDENT ON EXACTLY WHAT HAPPENS THE NIGHT BEFORE BUT
ENOUGH INSTABILITY SHOULD BE PRESENT FOR AT LEAST AN ISOLATED SEVERE
STORM THREAT. MORE OR LESS THE SAME ON MONDAY WITH A NEW FRONT AND
SIMILAR INSTABILITY IN PLACE.
THE LINGERING FRONTAL BOUNDARY THRU TUESDAY WILL KEEP RAIN CHANCES
GOING. WE MAY SEE A BRIEF REPRIEVE LATE TUESDAY THRU WEDNESDAY WITH
INFLUENCE OF SURFACE HI PRESSURE BUT A WARM FRONT LATE WEDNESDAY
NIGHT INTO THURSDAY WILL ALLOW FOR THE RETURN OF RAIN CHANCES INTO
THE AREA.
ANOTHER ROUND OF HEAT REMAINS ON TAP FOR PERHAPS AS EARLY AS
THURSDAY AFTERNOON...BUT MODEL CONSENSUS AGREES TO DELAY A DAY INTO
FRIDAY AND NEXT WEEKEND.
TES
&&
.AVIATION: (FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1157 PM CDT FRI JUL 17 2015
VFR AND DRY THRU THE TAF PERIOD. HAVE ADDED LLWS FOR COU AND UIN
OVERNIGHT. OTHERWISE...WINDS WILL BE SLY AND BECOME SWLY SHORTLY
AFTER SUNRISE AS MIXING OCCURS. COU AND UIN MAY SEE GUSTS TO
AROUND 20 KTS DURING THE AFTERNOON.
TILLY
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...HEAT ADVISORY FROM NOON TODAY TO 8 PM CDT SUNDAY FOR CRAWFORD MO-
IRON MO-MADISON MO-REYNOLDS MO-ST. FRANCOIS MO-STE.
GENEVIEVE MO-WASHINGTON MO.
HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR AUDRAIN MO-BOONE MO-
CALLAWAY MO-COLE MO-FRANKLIN MO-GASCONADE MO-JEFFERSON MO-
LINCOLN MO-MONITEAU MO-MONTGOMERY MO-OSAGE MO-ST. CHARLES
MO-ST. LOUIS CITY MO-ST. LOUIS MO-WARREN MO.
HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR KNOX MO-LEWIS MO-
MARION MO-MONROE MO-PIKE MO-RALLS MO-SHELBY MO.
IL...HEAT ADVISORY FROM NOON TODAY TO 8 PM CDT SUNDAY FOR BOND IL-
CLINTON IL-FAYETTE IL-MARION IL-MONTGOMERY IL-RANDOLPH IL-
WASHINGTON IL.
HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR CALHOUN IL-GREENE IL-
JERSEY IL-MACOUPIN IL-MADISON IL-MONROE IL-ST. CLAIR IL.
HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR ADAMS IL-BROWN IL-
PIKE IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1159 PM CDT FRI JUL 17 2015
.UPDATE:
ISSUED AT 931 PM CDT FRI JUL 17 2015
THUNDERSTORMS HAVE MOVED EAST OUT OF THE AREA AND RAP MASS FIELDS
NOT SHOWING ANY LIKELIHOOD OF REDEVELOPMENT OVERNIGHT. HAVE KEPT
WITH THE DRY FORECAST. STILL LOOKS LIKE A WARM AND MUGGY NIGHT AS
CURRENT DEWPOINTS ARE IN THE MID-UPPER 70S IN MOST AREAS WITH
CURRENT TEMPERATURES STILL IN THE 80S.
BRITT
&&
.SHORT TERM: (THROUGH LATE TONIGHT)
ISSUED AT 239 PM CDT FRI JUL 17 2015
PESKY NARROW BAND OF CONVECTION FROM NORTHERN OZARKS TO S
SECTIONS OF STL METRO HAS BEEN FINALLY BEGUN TO WEAKEN OVER THE
PAST HOUR OR SO, WHILE CONVECTION OVER SOUTHERN IL HAS
INTENSIFIED JUST A BIT AS IT ENCOUNTERS A SLIGHTLY MORE FAVORABLE
ENVIRONMENT/SLIGHTLY COOLER MID LEVEL TEMPS. WILL MAINTAIN SOME
SLIGHT CHANCE POPS FOR VERY EARLY THIS EVENING FOR SOUTHEAST
SECTIONS OF THE CWA...DUE TO THE COMBINATION OF CURRENT ACTIVITY
AS WELL AS POTENTIAL FOR SOME OF THE WEAKENING UPSTREAM
CONVECTION OVER SW MO ADVECTING INTO THE AREA. OTHERWISE AND
ELSEWHERE...DRY WEATHER IS FORECAST WITH THE EMPHASIS REMAINING
ON THE WARM AND MUGGY JULY AIRMASS. HAVE GONE WITH LOWS IN THE
70S, BUT ITS CERTAINLY POSSIBLE THAT HEAT ISLAND OF STL METRO MAY
HAVE TROUBLE DIPPING BELOW 80.
TRUETT
.LONG TERM: (SATURDAY THROUGH NEXT FRIDAY)
ISSUED AT 239 PM CDT FRI JUL 17 2015
OPPRESSIVELY HOT AND HUMID CONDITIONS WILL LIKELY CONTINUE ACROSS
MOST OF THE AREA THROUGH SUNDAY EVENING UNTIL A COLD FRONT EDGES
INTO MO/IL ON SUNDAY NIGHT. NO CHANGES WERE MADE TO THE EXISTING
HEAT ADVISORY.
A WEAK VORT MAX ACCOMPANYING THE COLD FRONT SHOULD SUPPORT SCT
SH/TS AHEAD OF THE FRONT ON LATE SUNDAY AFTERNOON FOLLOWED BY
INCREASINGLY ELEVATED CONVECTION INVOF THE FRONT ON SUNDAY NIGHT
INTO MONDAY. MODELS SHOW THAT THE FRONT WILL BE MOVING INTO AN
ENVIRONMENT WITH AROUND 2000 J/KG OF CAPE AND 20-30 KTS OF 0-6 KM
SHEAR AS WELL AS 2" PWAT AND H7-H5 LAPSE RATES OF 6-6.5 DEG
C/KM...THEREFORE STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE ON
SUNDAY AFTN/EVE.
ADDITIONAL VORT MAXES OR MCVS COULD SUPPORT ISO-SCT SH/TS EARLY
NEXT WEEK DURING A BRIEF PERIOD OF NW FLOW ALOFT UNTIL THE UPPER
RIDGE RE-ESTABLISHES ITSELF BY MID/LATE WEEK.
KANOFSKY
&&
.AVIATION: (FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1157 PM CDT FRI JUL 17 2015
VFR AND DRY THRU THE TAF PERIOD. HAVE ADDED LLWS FOR COU AND UIN
OVERNIGHT. OTHERWISE...WINDS WILL BE SLY AND BECOME SWLY SHORTLY
AFTER SUNRISE AS MIXING OCCURS. COU AND UIN MAY SEE GUSTS TO
AROUND 20 KTS DURING THE AFTERNOON.
TILLY
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...HEAT ADVISORY FROM NOON SATURDAY TO 8 PM CDT SUNDAY FOR CRAWFORD
MO-IRON MO-MADISON MO-REYNOLDS MO-ST. FRANCOIS MO-STE.
GENEVIEVE MO-WASHINGTON MO.
HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR AUDRAIN MO-BOONE MO-
CALLAWAY MO-COLE MO-FRANKLIN MO-GASCONADE MO-JEFFERSON MO-
LINCOLN MO-MONITEAU MO-MONTGOMERY MO-OSAGE MO-ST. CHARLES
MO-ST. LOUIS CITY MO-ST. LOUIS MO-WARREN MO.
HEAT ADVISORY UNTIL 8 PM CDT SATURDAY FOR KNOX MO-LEWIS MO-
MARION MO-MONROE MO-PIKE MO-RALLS MO-SHELBY MO.
IL...HEAT ADVISORY FROM NOON SATURDAY TO 8 PM CDT SUNDAY FOR BOND IL-
CLINTON IL-FAYETTE IL-MARION IL-MONTGOMERY IL-RANDOLPH IL-
WASHINGTON IL.
HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR CALHOUN IL-GREENE IL-
JERSEY IL-MACOUPIN IL-MADISON IL-MONROE IL-ST. CLAIR IL.
HEAT ADVISORY UNTIL 8 PM CDT SATURDAY FOR ADAMS IL-BROWN IL-PIKE
IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
856 PM MDT SUN JUL 19 2015
.DISCUSSION...
BOTH HRRR AND RUC ANALYSIS A BIT AGGRESSIVE IN
DEVELOPING SHOWERS ACROSS PORTIONS OF THE HI-LINE THIS EVENING.
MODELS CONTINUE TO BRING A WEAK BOUNDARY SOUTH ACROSS THE BORDER
OVERNIGHT BUT HAVE LOWERED POPS UNTIL AFTER MIDNIGHT, WHEN SHOWERS
ARE MORE LIKELY TO DEVELOP. TEMPERATURES LOOK GOOD.
&&
.AVIATION...
UPDATED 2350Z.
MID-LEVEL CLOUDS CONTINUE TO INCREASE AHEAD OF A
BOUNDARY THAT WILL BRING A CHANCE OF SHOWERS TO THE HI-LINE
OVERNIGHT. THE AIRMASS WILL BECOME UNSTABLE AGAIN AFTER 18Z WITH
SCATTERED AFTERNOON THUNDERSTORMS DEVELOPING. VFR CONDITIONS PREVAIL
WITH MVFR CONDITIONS POSSIBLE IN THE VICINITY OF SHOWERS AND/OR
THUNDERSTORMS ALONG WITH GUSTY ERRATIC WINDS.
&&
.PREV DISCUSSION...ISSUED 257 PM MDT SUN JUL 19 2015
TONIGHT THROUGH TUESDAY...NORTHWEST FLOW ALOFT WILL CONTINUE
OVERNIGHT THROUGH MID-DAY MONDAY BEFORE SHORTWAVE RIDGING MOVES
OVER THE STATE. THIS FEATURE WILL BE WEAK AND TRANSIENT EXISTING
JUST LONG ENOUGH TO SWITCH THE FLOW ALOFT TO WESTERLY BEFORE THE
NEXT APPROACHING TROUGH BACKS IT AROUND TO THE SOUTHWEST AGAIN.
MODELS CONTINUE TO BRING A WEAK BOUNDARY SOUTHWARD INTO NORTH
CENTRAL MONTANA WITH ISOLATED TO SCATTERED SHOWERS DEVELOPING
ALONG THE HI-LINE OVERNIGHT. SCATTERED SHOWERS AND A FEW
THUNDERSTORMS CONTINUE THROUGH MONDAY MORNING BEFORE BECOMING
ENHANCED BY A DISTURBANCE ALOFT MONDAY AFTERNOON AND EVENING.
OVERNIGHT AIRMASS STABILITY IS EXPECTED TO DIMINISH THE SHOWERS
LATE MONDAY NIGHT THROUGH TUESDAY MORNING. HOWEVER, INSTABILITY IN
THE SOUTHWEST FLOW AHEAD OF THE NEXT TROUGH WILL TRIGGER ISOLATED
TO SCATTERED SHOWERS AND THUNDERSTORMS OVER SOUTHWEST MONTANA
TUESDAY AFTERNOON. HIGH TEMPERATURES ON MONDAY AND TUESDAY WILL
CLIMB 5 TO 10 DEGREES ABOVE SEASONAL AVERAGES. MPJ
TUESDAY NIGHT THROUGH SUNDAY...AN UPPER LEVEL LOW PRESSURE TROF WILL
MOVE OVER THE WEST COAST TUESDAY NIGHT. THIS WILL BRING A PERIOD OF
FALLING HEIGHTS ALOFT WITH INCREASING INSTABILITY. THE BEST CHANCE
FOR CONVECTION WILL BE OVER THE SOUTHWEST ZONES WHERE UNSETTLED
SOUTHWEST FLOW ALOFT WILL ALSO BRING ADDITIONAL MOISTURE INTO THE
AIRMASS. AN ASSOCIATED COLD FRONT WILL CROSS THE ROCKIES EARLY
WEDNESDAY AND PUSH ACROSS THE ZONES. THIS FRONT DOES NOT LOOK QUITE
AS STRONG AS EARLIER MODELS HAD FORECAST. THE TROF WILL BE
BROADENING AND MOVING SLOWLY AS IT CROSSES THE PACIFIC NORTHWEST
THURSDAY AND BY FRIDAY, AS IT MOVES OVER THE ZONES, FLOW ALOFT WILL
BE NEARLY ZONAL. A WEAK RIDGE WILL BUILD OVER THE ZONES FRIDAY NIGHT
BUT ANOTHER LOW PRESSURE TROF WILL BE APPROACHING THE WEST COAST AND
HEIGHTS ALOFT OVER THE ZONES WILL ALREADY BE DROPPING BY SATURDAY.
THE TROF WILL SLOWLY MOVE OVER THE PACIFIC NORTHWEST BY SUNDAY
NIGHT AND THE AIRMASS WILL BECOME MORE UNSETTLED BY THE VERY END
OF THE FORECAST PERIOD. ZELZER
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 57 87 57 90 / 10 30 20 10
CTB 53 84 52 85 / 20 30 10 10
HLN 60 89 60 92 / 10 20 20 20
BZN 53 87 53 89 / 10 20 20 10
WEY 42 74 43 76 / 10 10 10 30
DLN 51 83 52 85 / 10 20 20 20
HVR 56 87 56 93 / 30 20 30 10
LWT 55 84 56 89 / 20 20 20 20
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
WEATHER.GOV/GREATFALLS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
947 PM CDT SUN JUL 19 2015
.SYNOPSIS...
ISSUED AT 330 PM CDT SUN JUL 19 2015
BROAD UPPER LEVEL RIDGE ACROSS THE SOUTHERN CONUS WITH GENERALLY
ZONAL FLOW ACROSS THE AREA. REMNANTS OF TROPICAL SYSTEM DOLORES
ADDING MOISTURE TO THE MONSOON OF THE 4 CORNERS REGION. SFC STALLED
BOUNDARY STRETCHES ACROSS MISSOURI/KANSAS AND ALONG THE FRONT RANGE
IN COLORADO. ALSO ANALYZING A WEAK TROUGH MOVING ACROSS NORTHEAST
WYOMING AND WESTERN S DAKOTA. TEMPERATURES THIS AFTERNOON HAVE
WARMED INTO THE 80S WITH PARTLY CLOUDY SKIES.
&&
.UPDATE...
ISSUED AT 947 PM CDT SUN JUL 19 2015
UPDATED THE FORECAST TO ACCOUNT FOR LESSENING PRECIP CHANCES
THROUGH THE REMAINDER OF THE OVERNIGHT HOURS...WITH THE EXCEPTION
OF WHERE TSRA IS ONGOING. DECENT PV ANOMALY MOVING INTO SOUTHWEST
SD ATTM AND HELPING TO FOCUS TSRA IN THE CLUSTER MOVING ESEWD IN
NC NEB. THIS AREA SHOULD CONTINUE TO PUSH SEWD THROUGH THE NIGHT
BUT SHOULD WEAKEN AS BEST LLJ LOCATED SOUTH INTO KS. COULD BE A
FEW ISOLD SHOWERS/WEAK STORMS AHEAD OF SEWD ADVANCING COLD FRONT
OVERNIGHT AND HAVE KEPT THAT MENTION IN THE FCST. LOWS WILL BE
TRICKY AS INCREASING LOW LEVEL MOISTURE SHOULD KEEP TEMPS UP...BUT
DRIER AIR ASSOCIATED WITH THE COLD FRONT WILL ALLOW TEMPS TO DROP
BEHIND IT.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 330 PM CDT SUN JUL 19 2015
ANOTHER ROUND OF STORMS EXPECTED TONIGHT. THERE ARE TWO FOCUS POINTS
OF INTEREST TONIGHT FOR THUNDERSTORM ACTIVITY. ONE WILL BE AN UPPER
LEVEL DISTURBANCE RIDING ALONG THE NORTHERN PERIPHERY OF THE RIDGE.
THIS TRACK RESEMBLES THE ONE FROM YESTERDAY AND WILL IMPACT MAINLY
SOUTHWESTERN NEB. A COUPLE STORMS ALREADY FIRING ACROSS THE SOUTHERN
PANHANDLE AND NORTHEASTERN CO. ACTIVITY WILL INCREASE...BECOMING SCT
TO POSSIBLY A BROKEN LINE AS IT DRIFTS EAST. CAPE VALUES AROUND OR
GREATER THAN 1500 J/KG AND LOW LEVEL SHEAR OF 35-40 KTS SHOULD
SUFFICE FOR SOME SEVERE THUNDERSTORMS WITH WIND AND HAIL THE MAIN
THREAT. MEANWHILE THE SECOND AREA OF FOCUS WILL BE THE PROGRESSING
EASTWARD TROUGH ACROSS THE NORTH. MOISTURE LIMITED THIS EVENING
INITIALLY WITH DEW PTS ONLY IN THE LOWER 60S...HOWEVER RECENT
RAINFALL AND SOUTHERLY WINDS SHOULD BE ABLE TO BRING THOSE UP TO THE
MID AND UPPER 60S BY THE ARRIVAL OF THE TROUGH. SHEAR IS A LITTLE
WEAKER AND SEVERE THREAT NOT AS HIGH AS TO THE SOUTH...ALTHOUGH
STILL MARGINAL.
STORMS ADVANCE TO THE EAST AND EXIT THE CWA OVERNIGHT. WITH SOME
CLEARING BEHIND THE STORMS...TEMPS TO FALL INTO THE MID AND UPPER
50S OUT WEST...WHILE LOWER 60S ARE EXPECTED IN THE EAST WHERE CLOUDS
LAST TO DEPART. TOMORROW WILL CONTINUE TO SEE THE STALLED BOUNDARY
TO THE SOUTH WITH LITTLE CHANGE TO THE AIRMASS OVERHEAD. HIGHS
SHOULD BE SIMILAR...MID AND UPPER 80S WITH MAYBE A LOW 90 ACROSS THE
SOUTHWEST AS WE SEE A LITTLE MORE SUN. ANOTHER WAVE WILL MOVE ACROSS
THE ROCKIES DURING THE DAY BUT STORMS SHOULD REMAIN ACROSS THE
HIGHER COUNTRY TO THE WEST THROUGH THE AFTERNOON HOURS.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 PM CDT SUN JUL 19 2015
MID AND LONG TERM MODELS IN GOOD AGREEMENT AND HAVE GOOD
CONFIDENCE IN THE FORECAST. MONDAY NIGHT...SURFACE HIGH CENTERED
OVER SIOUX FALLS. UPSLOPE CONDITIONS OVER WESTERN NEBRASKA WITH A
WEAK COLD FRONT MOVING SOUTH OVER WESTERN NEBRASKA...MID LEVEL
WAVE MOVING ACROSS WYOMING. HAVE RETAINED SCHC POPS OVER THE
EASTERN NEBRASKA PANHANDLE AND CARRIED THEM INTO TUESDAY WITH
HIGHER CHANCES AS THE MID LEVEL WAVE MOVE EAST. HIGHS IN THE 80S
BEHIND THE FRONT. HAVE RETAINED PRECIP CHANCES TUESDAY NIGHT OVER
WESTERN NEBRASKA WITH SURFACE BOUNDARY ALONG NEBRASKA KANSAS
BORDER AND WEAK WAVE MOVING THROUGH THE SOUTHWEST FLOW. HIGHS
WEDNESDAY IN THE 80S. RIDGE BUILDS IN AND HEAT RETURNS THURSDAY
INTO THE WEEKEND WITH HIGHS IN THE 90S. STRONGER WAVE MOVES
THROUGH ON SATURDAY WITH BEST CHANCES FOR PRECIPITATION OVER
WESTERN NEBRASKA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 625 PM CDT SUN JUL 19 2015
FCST CHALLENGE AGAIN DEALS WITH CONVECTIVE POTENTIAL AND
TIMING...THEN FRONTAL PASSGE FROM NORTHWEST TO SOUTHEAST. TSRA
ALREADY DEVELOPING IN SW NEB FORCED PRIMAILY FROM WEAK UPSLOPE FLOW
TO THE NORTH OF A QUASI-STATIONARY FRONT IN KS AND UP AGAINST THE
FRONT RANGE...AIDED BY A SUBTLE WAVE MOVING NEWD ACROSS CO. DEEP
MOIST CONVECTIVE IS MAXIMIZED ACROSS WRN KS PER SPC MESOANALYSIS AND
WITH DEEPER BL MOISTURE IN THIS AREA WOULD EXPECT TSRA IN THIS
REGION TO GROW UPSCALE...THOUGH PRIMARILY SOUTH OF THE KLBF TAF
SITE. STORMS ARE SPLITTING ONCE AGAIN...SO THERE MAY BE A FEW
DIFFERENT MOTION VECTORS FOR EACH ORGANIZED UPDRAFT. THE CAVEAT TO
THIS IS NEW DEVELOPMENT ALONG ANY OUTFLOW BOUNDARIES...AND CURRENT
TSRA MAY BE ALONG A LEFT OVER BOUNDARY FROM LAST NIGHT.
REGARDLESS...TSRA SHOULD STILL BE ABLE TO PROPAGATE NEWD FOR A TIME
THIS EVENING BEFORE LARGER CLUSTER TAKES OVER FURTHER SOUTH. THIS IS
IN LINE WITH LATEST HRRR RUNS.
FURTHER N...MORE POTENT PV ANOMALY MOVING INTO WRN SD ATTM. A WEAKER
SFC FEATURE MAY BE EVIDENT ACROSS SC SD JUST NORTH OF KVTN. LARGER
SCALE LIFT ASSOCIATED WITH THE PV ANOMALY SHOULD BE ABLE TO FOCUS
CONVERGENCE ALONG THIS FEATURE AND THE ATTENDANT COLD FRONT WHICH
WILL MOVE INTO NW NEB LATE EVENING. FCST INCLUDES THIS POTENTIAL FOR
THE KVTN AREA THIS EVENING. AFTER CONVECTION CLEARS THE
AREA...PRIMARILY AFTER 07Z OR SO SKIES SHOULD GRADUALLY CLEAR AND
VFR THEREAFTER.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JWS
SYNOPSIS...MASEK
SHORT TERM...MASEK
LONG TERM...POWER
AVIATION...JWS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
625 PM CDT SUN JUL 19 2015
.SYNOPSIS...
ISSUED AT 330 PM CDT SUN JUL 19 2015
BROAD UPPER LEVEL RIDGE ACROSS THE SOUTHERN CONUS WITH GENERALLY
ZONAL FLOW ACROSS THE AREA. REMNANTS OF TROPICAL SYSTEM DOLORES
ADDING MOISTURE TO THE MONSOON OF THE 4 CORNERS REGION. SFC STALLED
BOUNDARY STRETCHES ACROSS MISSOURI/KANSAS AND ALONG THE FRONT RANGE
IN COLORADO. ALSO ANALYZING A WEAK TROUGH MOVING ACROSS NORTHEAST
WYOMING AND WESTERN S DAKOTA. TEMPERATURES THIS AFTERNOON HAVE
WARMED INTO THE 80S WITH PARTLY CLOUDY SKIES.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 330 PM CDT SUN JUL 19 2015
ANOTHER ROUND OF STORMS EXPECTED TONIGHT. THERE ARE TWO FOCUS POINTS
OF INTEREST TONIGHT FOR THUNDERSTORM ACTIVITY. ONE WILL BE AN UPPER
LEVEL DISTURBANCE RIDING ALONG THE NORTHERN PERIPHERY OF THE RIDGE.
THIS TRACK RESEMBLES THE ONE FROM YESTERDAY AND WILL IMPACT MAINLY
SOUTHWESTERN NEB. A COUPLE STORMS ALREADY FIRING ACROSS THE SOUTHERN
PANHANDLE AND NORTHEASTERN CO. ACTIVITY WILL INCREASE...BECOMING SCT
TO POSSIBLY A BROKEN LINE AS IT DRIFTS EAST. CAPE VALUES AROUND OR
GREATER THAN 1500 J/KG AND LOW LEVEL SHEAR OF 35-40 KTS SHOULD
SUFFICE FOR SOME SEVERE THUNDERSTORMS WITH WIND AND HAIL THE MAIN
THREAT. MEANWHILE THE SECOND AREA OF FOCUS WILL BE THE PROGRESSING
EASTWARD TROUGH ACROSS THE NORTH. MOISTURE LIMITED THIS EVENING
INITIALLY WITH DEW PTS ONLY IN THE LOWER 60S...HOWEVER RECENT
RAINFALL AND SOUTHERLY WINDS SHOULD BE ABLE TO BRING THOSE UP TO THE
MID AND UPPER 60S BY THE ARRIVAL OF THE TROUGH. SHEAR IS A LITTLE
WEAKER AND SEVERE THREAT NOT AS HIGH AS TO THE SOUTH...ALTHOUGH
STILL MARGINAL.
STORMS ADVANCE TO THE EAST AND EXIT THE CWA OVERNIGHT. WITH SOME
CLEARING BEHIND THE STORMS...TEMPS TO FALL INTO THE MID AND UPPER
50S OUT WEST...WHILE LOWER 60S ARE EXPECTED IN THE EAST WHERE CLOUDS
LAST TO DEPART. TOMORROW WILL CONTINUE TO SEE THE STALLED BOUNDARY
TO THE SOUTH WITH LITTLE CHANGE TO THE AIRMASS OVERHEAD. HIGHS
SHOULD BE SIMILAR...MID AND UPPER 80S WITH MAYBE A LOW 90 ACROSS THE
SOUTHWEST AS WE SEE A LITTLE MORE SUN. ANOTHER WAVE WILL MOVE ACROSS
THE ROCKIES DURING THE DAY BUT STORMS SHOULD REMAIN ACROSS THE
HIGHER COUNTRY TO THE WEST THROUGH THE AFTERNOON HOURS.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 PM CDT SUN JUL 19 2015
MID AND LONG TERM MODELS IN GOOD AGREEMENT AND HAVE GOOD
CONFIDENCE IN THE FORECAST. MONDAY NIGHT...SURFACE HIGH CENTERED
OVER SIOUX FALLS. UPSLOPE CONDITIONS OVER WESTERN NEBRASKA WITH A
WEAK COLD FRONT MOVING SOUTH OVER WESTERN NEBRASKA...MID LEVEL
WAVE MOVING ACROSS WYOMING. HAVE RETAINED SCHC POPS OVER THE
EASTERN NEBRASKA PANHANDLE AND CARRIED THEM INTO TUESDAY WITH
HIGHER CHANCES AS THE MID LEVEL WAVE MOVE EAST. HIGHS IN THE 80S
BEHIND THE FRONT. HAVE RETAINED PRECIP CHANCES TUESDAY NIGHT OVER
WESTERN NEBRASKA WITH SURFACE BOUNDARY ALONG NEBRASKA KANSAS
BORDER AND WEAK WAVE MOVING THROUGH THE SOUTHWEST FLOW. HIGHS
WEDNESDAY IN THE 80S. RIDGE BUILDS IN AND HEAT RETURNS THURSDAY
INTO THE WEEKEND WITH HIGHS IN THE 90S. STRONGER WAVE MOVES
THROUGH ON SATURDAY WITH BEST CHANCES FOR PRECIPITATION OVER
WESTERN NEBRASKA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 625 PM CDT SUN JUL 19 2015
FCST CHALLENGE AGAIN DEALS WITH CONVECTIVE POTENTIAL AND
TIMING...THEN FRONTAL PASSGE FROM NORTHWEST TO SOUTHEAST. TSRA
ALREADY DEVELOPING IN SW NEB FORCED PRIMAILY FROM WEAK UPSLOPE FLOW
TO THE NORTH OF A QUASI-STATIONARY FRONT IN KS AND UP AGAINST THE
FRONT RANGE...AIDED BY A SUBTLE WAVE MOVING NEWD ACROSS CO. DEEP
MOIST CONVECTIVE IS MAXIMIZED ACROSS WRN KS PER SPC MESOANALYSIS AND
WITH DEEPER BL MOISTURE IN THIS AREA WOULD EXPECT TSRA IN THIS
REGION TO GROW UPSCALE...THOUGH PRIMARILY SOUTH OF THE KLBF TAF
SITE. STORMS ARE SPLITTING ONCE AGAIN...SO THERE MAY BE A FEW
DIFFERENT MOTION VECTORS FOR EACH ORGANIZED UPDRAFT. THE CAVEAT TO
THIS IS NEW DEVELOPMENT ALONG ANY OUTFLOW BOUNDARIES...AND CURRENT
TSRA MAY BE ALONG A LEFT OVER BOUNDARY FROM LAST NIGHT.
REGARDLESS...TSRA SHOULD STILL BE ABLE TO PROPAGATE NEWD FOR A TIME
THIS EVENING BEFORE LARGER CLUSTER TAKES OVER FURTHER SOUTH. THIS IS
IN LINE WITH LATEST HRRR RUNS.
FURTHER N...MORE POTENT PV ANOMALY MOVING INTO WRN SD ATTM. A WEAKER
SFC FEATURE MAY BE EVIDENT ACROSS SC SD JUST NORTH OF KVTN. LARGER
SCALE LIFT ASSOCIATED WITH THE PV ANOMALY SHOULD BE ABLE TO FOCUS
CONVERGENCE ALONG THIS FEATURE AND THE ATTENDANT COLD FRONT WHICH
WILL MOVE INTO NW NEB LATE EVENING. FCST INCLUDES THIS POTENTIAL FOR
THE KVTN AREA THIS EVENING. AFTER CONVECTION CLEARS THE
AREA...PRIMARILY AFTER 07Z OR SO SKIES SHOULD GRADUALLY CLEAR AND
VFR THEREAFTER.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MASEK
SHORT TERM...MASEK
LONG TERM...POWER
AVIATION...JWS
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1144 AM MDT SAT JUL 18 2015
.AVIATION...
18Z TAF CYCLE
MID LEVEL CLOUDS ACROSS WESTERN AND NORTHERN NEW MEXICO WILL
GRADUALLY THIN AS MID DAY CONVECTION STARTS TO DEVELOP.
THUNDERSTORMS AND SHOWERS TO DEVELOP A LITTLE LATER TODAY...AROUND
20Z...OVER THE WESTERN AND HIGHER TERRAIN THEN MOVE EAST
NORTHEAST. THUNDERSTORMS WILL DIMINISH IN THE EVENING WITH A
TRANSITION TO MOSTLY SHOWERS ACROSS THE NORTHWEST THIRD OF THE
FORECAST AREA. ANY THUNDERSTORM WILL BE CAPABLE OF PRODUCING MVFR
CIGS AND VISIBILITIES AND SOME OCCASIONAL MOUNTAIN OBSCURATIONS.
GRADUAL CLEARING OF ANOTHER MID LEVEL DECK EARLY ON SUNDAY. VFR
CONDITIONS EXPECTED OUTSIDE OF THUNDERSTORMS.
05
&&
.PREV DISCUSSION...1119 AM MDT SAT JUL 18 2015...
.UPDATE...
THICK CLOUD COVER WHICH WAS IN PLACE YESTERDAY HAS THINNED
TODAY...THEREFORE RAISED MOST HIGH TEMPERATURES FOR THIS
AFTERNOON. CONSEQUENTLY CONVECTION GETTING STARTED A BIT EARLIER
SO INCREASED POPS AT BIT NORTHERN MTS AND A LITTLE FARTHER EAST
INTO THE PLAINS PER LATEST RAP AND HRRR. UPDATED ZFP JUST
TRANSMITTED.
&&
.PREV DISCUSSION...331 AM MDT SAT JUL 18 2015...
.SYNOPSIS...
THE REMNANT CIRCULATION OF FORMER HURRICANE DOLORES WILL PASS WEST
THAN NORTH OF NEW MEXICO TODAY THROUGH EARLY NEXT WEEK...BUT IT
WILL STEER A RICH MONSOON MOISTURE PLUME OVER NEW MEXICO.
PRECIPITATION INTENSITY AND COVERAGE WILL INCREASE LATE TODAY AND
TONIGHT ACROSS WESTERN NEW MEXICO...THEN ALSO FARTHER EAST
SUNDAY AND MONDAY AS THE MOISTURE MOVES MORE DIRECTLY OVERHEAD.
SUNDAY NIGHT AND MONDAY A BACK DOOR COLD FRONT WILL PENETRATE
NORTHEAST AND EAST CENTRAL AREAS...HELPING TO TRIGGER
THUNDERSTORMS THERE. DRIER AIR WILL BEGIN TO MOVE INTO WESTERN
AREAS FROM THE WEST TUESDAY...BUT CENTRAL AND EASTERN AREAS SHOULD
HOLD ONTO ENOUGH MOISTURE FOR ANOTHER ROUND OF SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS. TEMPERATURES THROUGH THIS
PERIOD WILL GENERALLY BE NEAR AND BELOW NORMAL...EXCEPT FOR SOME
ABOVE NORMAL READINGS ACROSS PARTS OF THE PLAINS TODAY THROUGH
SUNDAY.
&&
.DISCUSSION...
MODELS CONTINUE TO PROG A LONG WAVE TROUGH OVER THE WEST COAST
THROUGH THE EXTENDED. THE UPPER HIGH EAST OF NM WILL HELP STEER
THE RICH PLUM OF MONSOON MOISTURE OVER NM LATE SATURDAY THROUGH
TUESDAY. A SHORTWAVE TROUGH IS FORECAST TO EJECT EAST
NORTHEASTWARD ACROSS THE NORTHERN ROCKIES LATE TODAY THROUGH
SUNDAY...HELPING TO SPREAD THE MONSOON MOISTURE PLUME OVER NM AND
CO FROM AZ AND UT. THIS FIRST TROUGH WILL SEND THE AFOREMENTIONED
BACK DOOR COLD FRONT INTO THE PLAINS. MODELS HAVE BEEN CHANGING
THE TIMING OF THIS FRONT FROM RUN TO RUN...AND THERE IS SOME
UNCERTAINTY ABOUT HOW FAR IT WILL PENETRATE SOUTHWESTWARD INTO NM.
THE REMNANT CIRCULATION FROM FORMER HURRICANE DOLORES IS NOW
FORECAST TO OPEN INTO A TROUGH AND CROSS THE CENTRAL ROCKIES JUST
NORTH OF NM MONDAY NIGHT THROUGH TUESDAY NIGHT. CENTRAL AND
EASTERN AREAS COULD BE QUITE WET TUESDAY AS MOIST LOW LEVEL AIR IS
DRAWN NORTHWESTWARD INTO THE AREA AND THE MONSOON MOISTURE PLUME
IS FOCUSED BY DRIER AIR MOVING IN FROM THE WEST. LOCALLY HEAVY
RAINFALL WILL BE ESPECIALLY LIKELY TUESDAY AFTERNOON AND
EVENING...BUT THE RISK WILL FOR MINOR FLOODING WILL PROBABLY START
IN EARNEST WITH SUNDAY NIGHTS BACK DOOR COLD FRONT. SOME STRONG
TO SEVERE STORMS WILL ALSO BE POSSIBLE MONDAY AND TUESDAY.
44
&&
.FIRE WEATHER...
ABUNDANT MOISTURE ORGANIZING OVER ARIZONA WILL MOVE
EAST INTO WESTERN NEW MEXICO TODAY THEN SLIDE ACROSS CENTRAL AND
EASTERN AREAS SUNDAY THROUGH TUESDAY. HUMIDITIES WILL TREND UP EACH
DAY WHILE HIGH TEMPS REMAIN BELOW NORMAL. A MOIST BACK DOOR FRONTAL
BOUNDARY WILL FLIRT WITH THE NORTHEAST PLAINS SUNDAY AND PROVIDE AN
UPTICK IN STORM COVERAGE WITH HEAVY RAINFALL. THE FRONT WILL GET A
NUDGE TO THE SOUTHWEST SUNDAY NIGHT AND MONDAY WHILE THE MONSOON
MOISTURE PLUME SHIFTS EAST. THIS WILL PROVIDE AN EVEN BETTER SET UP
FOR LARGER FOOTPRINTS OF LOCALLY HEAVY RAINFALL FROM THE CENTRAL MT
CHAIN EAST MONDAY AND TUESDAY.
A RATHER STRONG DRY INTRUSION FOR MID JULY IS THEN ADVERTISED BY
GUIDANCE TO WORK EAST ACROSS AT LEAST WESTERN NM AS EARLY AS
TUESDAY...BUT MORE CONFIDENTLY BY WEDNESDAY. THE UPPER HIGH WILL
ALSO STRENGTHEN OVER TX AND BEGAN DRIFTING WEST TOWARD NM THROUGH
THE END OF THE WEEK. HUMIDITIES ARE EXPECTED TO TREND DOWN WHILE MAX
TEMPS RETURN TO NEAR NORMAL. MANY AREAS MAY SEE MIN RH FALL TO BTWN
15 AND 20 PCT WEDNESDAY AND THURSDAY WITH ONLY ISOLATED STORMS ON
TAP FOR THE HIGH TERRAIN. WHATEVER STORMS DO FORM MAY STILL DROP
DECENT RAINFALL WITH VERY WEAK STORM MOTION.
CONFIDENCE BEYOND THURSDAY IS LOW WITH GUIDANCE INCONSISTENT ON HOW
THE UPPER LEVEL HIGH AND MOISTURE PATTERN EVOLVE. NONETHELESS...NO
SIGNIFICANT BURSTS OF WIDESPREAD HEAVY RAIN APPEAR IN THE EXTENDED
RANGE FOR NOW.
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1119 AM MDT SAT JUL 18 2015
.UPDATE...
THICK CLOUD COVER WHICH WAS IN PLACE YESTERDAY HAS THINNED
TODAY...THEREFORE RAISED MOST HIGH TEMPERATURES FOR THIS
AFTERNOON. CONSEQUENTLY CONVECTION GETTING STARTED A BIT EARLIER
SO INCREASED POPS AT BIT NORTHERN MTS AND A LITTLE FARTHER EAST
INTO THE PLAINS PER LATEST RAP AND HRRR. UPDATED ZFP JUST
TRANSMITTED.
&&
.PREV DISCUSSION...546 AM MDT SAT JUL 18 2015...
.AVIATION...
12Z TAF CYCLE
THE CURRENT MID LEVEL DECK OVER NORTHERN/WESTERN NM WILL GIVE WAY
TO -SHRA/TSRA BY LATE DAY AT TERMINALS. RECENT DAYS SUGGEST TIMING
OF IMPACTS AT TAF SITES ON LATER SIDE DUE TO ABUNDANT CLOUD COVER
AND BELOW NORMAL TEMPS. DEVELOPMENT WILL OCCUR NEAR 20-21Z ON THE
HIGH TERRAIN THEN SPAWN ACTIVITY ON OUTFLOW BOUNDARIES INTO LOWER
TERRAIN AREAS. FOCUSED TARGET WINDOW AFT 22Z ALONG AND WEST OF THE
CONT DVD AND NEAR THE SANGRE DE CRISTOS...THEN AFT 00Z FOR CENTRAL
NM AND RIO GRANDE VALLEY. SHRA IN THE EVENING WILL TAPER TO BROKEN
CIGS THRU THE OVERNIGHT. STORM MOTIONS WILL BE E/NE NEAR 10 KTS.
GUYER
&&
.PREV DISCUSSION...331 AM MDT SAT JUL 18 2015...
.SYNOPSIS...
THE REMNANT CIRCULATION OF FORMER HURRICANE DOLORES WILL PASS WEST
THAN NORTH OF NEW MEXICO TODAY THROUGH EARLY NEXT WEEK...BUT IT
WILL STEER A RICH MONSOON MOISTURE PLUME OVER NEW MEXICO.
PRECIPITATION INTENSITY AND COVERAGE WILL INCREASE LATE TODAY AND
TONIGHT ACROSS WESTERN NEW MEXICO...THEN ALSO FARTHER EAST
SUNDAY AND MONDAY AS THE MOISTURE MOVES MORE DIRECTLY OVERHEAD.
SUNDAY NIGHT AND MONDAY A BACK DOOR COLD FRONT WILL PENETRATE
NORTHEAST AND EAST CENTRAL AREAS...HELPING TO TRIGGER
THUNDERSTORMS THERE. DRIER AIR WILL BEGIN TO MOVE INTO WESTERN
AREAS FROM THE WEST TUESDAY...BUT CENTRAL AND EASTERN AREAS SHOULD
HOLD ONTO ENOUGH MOISTURE FOR ANOTHER ROUND OF SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS. TEMPERATURES THROUGH THIS
PERIOD WILL GENERALLY BE NEAR AND BELOW NORMAL...EXCEPT FOR SOME
ABOVE NORMAL READINGS ACROSS PARTS OF THE PLAINS TODAY THROUGH
SUNDAY.
&&
.DISCUSSION...
MODELS CONTINUE TO PROG A LONG WAVE TROUGH OVER THE WEST COAST
THROUGH THE EXTENDED. THE UPPER HIGH EAST OF NM WILL HELP STEER
THE RICH PLUM OF MONSOON MOISTURE OVER NM LATE SATURDAY THROUGH
TUESDAY. A SHORTWAVE TROUGH IS FORECAST TO EJECT EAST
NORTHEASTWARD ACROSS THE NORTHERN ROCKIES LATE TODAY THROUGH
SUNDAY...HELPING TO SPREAD THE MONSOON MOISTURE PLUME OVER NM AND
CO FROM AZ AND UT. THIS FIRST TROUGH WILL SEND THE AFOREMENTIONED
BACK DOOR COLD FRONT INTO THE PLAINS. MODELS HAVE BEEN CHANGING
THE TIMING OF THIS FRONT FROM RUN TO RUN...AND THERE IS SOME
UNCERTAINTY ABOUT HOW FAR IT WILL PENETRATE SOUTHWESTWARD INTO NM.
THE REMNANT CIRCULATION FROM FORMER HURRICANE DOLORES IS NOW
FORECAST TO OPEN INTO A TROUGH AND CROSS THE CENTRAL ROCKIES JUST
NORTH OF NM MONDAY NIGHT THROUGH TUESDAY NIGHT. CENTRAL AND
EASTERN AREAS COULD BE QUITE WET TUESDAY AS MOIST LOW LEVEL AIR IS
DRAWN NORTHWESTWARD INTO THE AREA AND THE MONSOON MOISTURE PLUME
IS FOCUSED BY DRIER AIR MOVING IN FROM THE WEST. LOCALLY HEAVY
RAINFALL WILL BE ESPECIALLY LIKELY TUESDAY AFTERNOON AND
EVENING...BUT THE RISK WILL FOR MINOR FLOODING WILL PROBABLY START
IN EARNEST WITH SUNDAY NIGHTS BACK DOOR COLD FRONT. SOME STRONG
TO SEVERE STORMS WILL ALSO BE POSSIBLE MONDAY AND TUESDAY.
44
&&
.FIRE WEATHER...
ABUNDANT MOISTURE ORGANIZING OVER ARIZONA WILL MOVE
EAST INTO WESTERN NEW MEXICO TODAY THEN SLIDE ACROSS CENTRAL AND
EASTERN AREAS SUNDAY THROUGH TUESDAY. HUMIDITIES WILL TREND UP EACH
DAY WHILE HIGH TEMPS REMAIN BELOW NORMAL. A MOIST BACK DOOR FRONTAL
BOUNDARY WILL FLIRT WITH THE NORTHEAST PLAINS SUNDAY AND PROVIDE AN
UPTICK IN STORM COVERAGE WITH HEAVY RAINFALL. THE FRONT WILL GET A
NUDGE TO THE SOUTHWEST SUNDAY NIGHT AND MONDAY WHILE THE MONSOON
MOISTURE PLUME SHIFTS EAST. THIS WILL PROVIDE AN EVEN BETTER SET UP
FOR LARGER FOOTPRINTS OF LOCALLY HEAVY RAINFALL FROM THE CENTRAL MT
CHAIN EAST MONDAY AND TUESDAY.
A RATHER STRONG DRY INTRUSION FOR MID JULY IS THEN ADVERTISED BY
GUIDANCE TO WORK EAST ACROSS AT LEAST WESTERN NM AS EARLY AS
TUESDAY...BUT MORE CONFIDENTLY BY WEDNESDAY. THE UPPER HIGH WILL
ALSO STRENGTHEN OVER TX AND BEGAN DRIFTING WEST TOWARD NM THROUGH
THE END OF THE WEEK. HUMIDITIES ARE EXPECTED TO TREND DOWN WHILE MAX
TEMPS RETURN TO NEAR NORMAL. MANY AREAS MAY SEE MIN RH FALL TO BTWN
15 AND 20 PCT WEDNESDAY AND THURSDAY WITH ONLY ISOLATED STORMS ON
TAP FOR THE HIGH TERRAIN. WHATEVER STORMS DO FORM MAY STILL DROP
DECENT RAINFALL WITH VERY WEAK STORM MOTION.
CONFIDENCE BEYOND THURSDAY IS LOW WITH GUIDANCE INCONSISTENT ON HOW
THE UPPER LEVEL HIGH AND MOISTURE PATTERN EVOLVE. NONETHELESS...NO
SIGNIFICANT BURSTS OF WIDESPREAD HEAVY RAIN APPEAR IN THE EXTENDED
RANGE FOR NOW.
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
331 PM EDT SAT JUL 18 2015
.SYNOPSIS...
ISOLATED TO SCATTERED THUNDERSTORMS WILL CONTINUE TO DEVELOP INTO
THIS EVENING WITH THE HIGHEST CHANCES ACROSS NORTHEAST
PENNSYLVANIA AND THE CATSKILLS. AFTER THE THUNDERSTORMS DIE DOWN
LATE THIS EVENING A VERY HUMID AND WARM AIR MASS WILL BE IN
PLACE. HIGHS SUNDAY WILL TOP 90 DEGREES IN MANY AREAS WITH HEAT
INDICES IN THE MID TO UPPER 90S DUE TO THE HIGH HUMIDITY. THE
INCREASE IN HEAT AND HUMIDITY ALONG WITH A COLD FRONT COULD PRODUCE
SEVERE THUNDERSTORMS LATER SUNDAY AFTERNOON AND NIGHT. MORE
COMFORTABLE AIR RETURNS TO THE AREA BY EARLY NEXT WEEK AFTER THIS COLD
FRONT PASSES EAST OF THE REGION.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
RADAR SHOWS ISOLATED SHRA AND TSRA ACROSS CENTRAL NEW YORK. THE
CONVECTION WAS VERY LIMITED IN SCOPE WITH VERY LITTLE COVERAGE.
THE 7.4 MICRON IMAGERY CONTINUES TO SHOW SIGNIFICANT DARKENING IN
NY/PA SUGGESTING MID-LEVEL SUBSDC BEHIND THE SHORT WAVE THAT WAS
PASSING TO OUR EAST. THIS SUBSDC WAS FIGHTING THE CONVECTIVE
HEATING AND UPDRAFTS AS MIXED LAYER CAPES WERE OVER2000 J/KG IN AS
LARGE PART OF C NY AND NE PA. ONCE THIS VERY DARK PATCH PASSES E
OF THE REGION LATER THIS AFTERNOON THE SUBSC WILL LESSEN AND
BELIEVE ACVTY WILL INCREASE IN COVERAGE TO SCT IN NE PA/SC NY AND
REMAIN JUST ISOLATED IN THE NORTH PART OF CENTRAL NY. THIS ACVTY
DOES HAVE A LOT OF CAPE TO WORK WITH...BUT A SIGNIFICANT AMOUNT OF
DRY AIR AT MID TO UPPER LEVELS ALSO WAS HAMPERING DEVELOPMENT PLUS LACK
OF STRG FORCING. HENCE WE DON/T BELIEVE THERE WILL BE ANY
ORGANIZATION AND WE WILL HAVE POPS FROM SLGHT CHC TO CHC WITH THE
HIGHEST CHC IN NE PA/CATSKILLS AND LEAST CHC IN OUR LAKE ONTARIO
PLAIN COUNTIES. WE ARE NOT EXPECTING ANY SEVERE WEATHER WITH THIS
ACVTY. SINCE THE PRESENT ACVTY WAS DIURNALLY DRIVEN IT SHUD
WEAKEN AFTER SUNSET.
THEN SCT SHRA AND TSRA CUD ARRIVE AGAIN BTWN 9Z-12Z SUN OR SO AS
REMNANTS OF CONVECTIVE ACVTY OVER LOWER MICHIGAN ARE PROGGED TO
REACH C NY AS PER RAP AND HRRR. OTHER MODELS HINTS AT THIS TOO. IF
ANY ACVTY REACHES C NY IT WILL WEAKEN AFTER SUNRISE. HAVE SOME
POPS FOR THIS ACVTY AS WELL.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY/...
OUR ATTENTION TURNS TO A POTENTIAL SEVERE WEATHER OUTBREAK FOR
SUNDAY AFTERNOON/NIGHT. THE EURO...GFS...NAM...CMC AS WELL AS
HIGHER RESOLUTION MODELS ALL INDICATE SIGNIFICANT INSTABILITY
DEVELOPING SUNDAY AFTERNOON WITH THE PROJECTED HEAT AND HUMIDITY.
CAPES ON THE HI RES MODELS RANGE FROM 2000-4000 J/KG...LI/S ON
THE EURO ARE BETWEEN -8C AND -10C AT 00Z MON...THE GEM GETS DOWN
TO -8C LI. THIS INSTABILITY OCCURS AS A STRG UPR LVL JET MAX MOVES
INTO THE EASTERN GREAT LAKES BY 00Z MON AND PUSHES A COLD FRONT
INTO THIS AREA AS WELL. AS A RESULT...SHEAR PROFILES LOOK
IMPRESSIVE LATE IN THE DAY AS THIS MID TO UPPER LEVEL WIND MAX
ARRIVES. THIS WHOLE SHORT WAVE WAS RIDING E-SE TWD NY AND PA SUN
PM OVER THE UPPER LEVEL RDG WHICH IS RETROGRADING TO THE SC U.S.
THIS IS A CLASSIC NW FLOW SEVERE WEATHER PATTERN FOR OUR AREA.
GIVEN THE RESULTANT SHEAR PROFILES OF ARND 20 KNOTS 0-1 KM BULK
SHEAR...30-35 KNOTS 0-3 KM AND POTENTIALLY UP TO 50 KNOTS 0-6
KM SHEAR...WE CUD BE LOOKING AT AN EVENT WHERE SUPERCELLS FORM IN
THE EASTERN LAKES WHICH MERGE INTO A SQUALL LINE/DERECHO BY THE
TIME IT REACHES C NY AND NE PA SUN EVE. OUR LOCAL SEVERE WEATHER
CHECKLIST RETURNS A COUPLE OF OUR BIGGER DERECHO EVENTS. CONCUR
WITH SPC EXPANDING SLGHT RISK TO COVER OUR WHOLE AREA LATER SUNDAY
AND SUNDAY NIGHT AND WOULDN`T BE SURPRISED TO SEE THIS UPGRADED
FURTHER IF THE ABOVE MENTIONED PARAMETERS PERSIST ON THE LATER
MODEL RUNS.
IN ADDTN...GIVEN HOW WET IT HAS BEEN LATELY AND THE TROPICAL
CONNECTION THAT THIS NEXT WAVE HAS AS POINTED OUT BY WFO
BUFFALO...IF RAIN RATES ARE HEAVY ENOUGH THERE CUD BE SOME
LOCALIZED FLASH FLOODING. IT IS POSSIBLE THAT THE STORMS ARE
MOVING TOO FAST TO PRECLUDE MAJOR FLASH FLOODING SO JUST MENTIONED
FLASH FLOOD POTENTIAL IN HWO FOR NOW. ALSO MENTIONED POTENTIAL
FOR A SEVERE WEATHER OUTBREAK IN HWO.
LASTLY HEAT INDICES WILL RANGE IN THE MID TO UPPER 90S MOST AREAS
SUNDAY WHICH FALLS SHORT OF OUR HEAT ADVY CRITERIA OF 100F. WE
KEPT MENTION OF HEAT IN HWO FOR GOOD MEASURE.
WE EXPECT ANY ORGANIZED THUNDERSTORMS TO EXIT THE FORECAST AREA
LATE SUNDAY NIGHT WITH WEAK HIGH PRESSURE AND FAIR AND COOLER
WEATEHR FOR MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
230 PM UPDATE...
MONDAY NIGHT A WEAK RIDGE OF HIGH PRESSURE MOVES IN. MODELS BRING
IN A MODERATE STRENGTH SYSTEM WITH A SFC COLD FRONT AND UPPER
LEVEL TROF TUESDAY. MIDDAY FROPA NOT THE BEST FOR HEATING TO HELP
THE INSTABILITY. TIMING HAS CHANGED ON THIS AND STILL SEVERAL DAYS
OUT SO IT COULD CHANGE AGAIN.
FOLLOWED WPC GUIDANCE TUES NGT ON. BIGGEST CHANGE WAS TO LOWER
TEMPS SEVERAL DEGREES. SO NOW TEMPERATURES AT OR SLIGHTLY BELOW
NORMAL. EURO HAS A DEEPER TROF THAT LASTS LONGER.
SHOWERS MOVE OUT TUESDAY EVENING THEN HIGH PRESSURE BUILDS IN THU
AND LASTS INTO SATURDAY. CANADIAN AND EURO SIMILAR BUT GFS HAS
WEAK SYSTEMS MOVING THROUGH THE AREA THE ENTIRE WEEK.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
130 PM UPDATE...
MAINLY VFR INTO MIDDAY SUNDAY.
UP TO 20Z SOME SHOWERS ITH/BGM COULD CAUSE PERIODS OF MVFR CIGS
AND MAYBE VSBY. THESE SHOWERS SHOULD GET INTO AVP 20 TO 23Z WITH
SIMILAR RESULTS.
CLOUDS SHOULD DIMINISH THIS EVE WITH THE LOSS OF HEATING. WINDS
WILL GO LIGHT SO ELM COULD AGAIN HAVE IFR CONDITIONS NEAR FLIGHT
MINIMUMS 9 TO 12Z. BGM/AVP/ITH SHOULD FALL TO MVFR VSBYS WITH THE
SATURATED LOW LEVELS AND THE RAIN TODAY.
SUNDAY CONVECTION SHOULD START AFTER 18Z. LATE TONIGHT TO SUNDAY
MORNING SOME CONVECTIVE DEBRIS MAKE IT INTO THE THE AREA
ESPECIALLY THE NORTH.
SW WINDS SOUTH AND NW WINDS NORTH AT 10 KTS DROP TO LIGHT AND
VARIABLE OR CALM THIS EVENING AND LAST INTO SUNDAY MORNING. SUNDAY
AFTER 14Z SW WINDS AT 5 TO 10 KTS.
.OUTLOOK...
SUN AFTN THRU TUE...A FEW RESTRICTIONS FROM SCT SHRA-
TSRA...ESPECIALLY WITH FRONTAL PASSAGE LATE SUN AND AGAIN TUE.
WED...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...DJN
LONG TERM...TAC
AVIATION...TAC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
250 PM EDT SAT JUL 18 2015
.SYNOPSIS...
ISOLATED TO SCATTERED THUNDERSTORMS WILL DEVELOP THIS AFTERNOON,
WITH THE HIGHEST CHANCES ACROSS NORTHEAST PENNSYLVANIA AND THE
CATSKILLS. AFTER THE THUNDERSTORMS DIE DOWN THIS EVENING A VERY
HUMID AND WARM AIR MASS WILL BE IN PLACE. HIGHS SUNDAY WILL TOP 90
DEGREES IN MANY AREAS WITH HEAT INDICES APPROACHING 100 DEGREES
DUE TO THE HIGH HUMIDITY. THE INCREASE IN HEAT AND HUMIDITY ALONG
WITH A COLD FRONT MAY PRODUCE STRONG STORMS SUNDAY AFTERNOON AND
NIGHT. MORE COMFORTABLE AIR RETURNS TO THE AREA BY EARLY NEXT
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST KBGM RADAR SHOWS JUST A FEW ISOLATED SHRA IN PARTS OF THE
WESTERN CATSKILLS AND EXTREME NE PA AT THIS TIME WITH A FEW
SHRA/TSRA IN THE ALLEGHENIES OF WRN NY AND NC PA. LARGE SCALE
MOSAIC RADAR IMAGERY SHOWS AN MCS MOVING ACRS LAKE MICHIGAN AND
LWR MICHIGAN. THE HRRR...WRF_ARW...WRF_NMM...RAP AND NAM ALL SHOW
THAT THIS MCS WILL DIVE SE AND FALL APART AS DIURNAL HEATING
KICKS IN AND DISRUPTS THE INFLOW INTO THIS FEATURE. MODELS ALSO
SHOW ANOTHER SHORT WAVE PASSING ACRS NY AND PA THIS AFTERNOON
WHICH COULD BE CONVECTIVELY INDUCED BY THIS MCS. IN ADDTN...MODEL
MIXED LAYER CAPES THIS AFTERNOON VARY FROM 3000 TO 4000 J/KG ON
THE LATEST NAM...TO 2000-3000 J/KG ON THE WRF_NMM....TO 1000 TO
2000 J/KG ON THE HRRR AND WRF_ARW. THE GFS HAS AROUND 1000 J/KG.
VISIBLE SATELLITE IMAGERY ALSO SHOWS BREAKS AND DESTABILIZATION
BEGINNING TO TAKE PLACE. THE WATER VAPOR AND 7.4 MICRON IMAGERY
SHOWS A LOT OF DRY AIR ADVECTING OVER NY AND PA AS WELL LATE THIS
MORNING WITH STRG MID-LVL SUBSDC AT PRESENT. AS THIS SMALL SHORT
WAVE WORKS E THIS AFTERNOON THERE WILL BE SOME ASCENT AND ALL HI
RES CONVECTION ALLOWING MODELS POP MOST OF THE CONVECTION AS PER
MODEL RADAR IMAGERY FROM SC NY TO NE PA. SO HAVE HIGHEST POPS THIS
AFTERNOON INTO EARLY EVENING IN NE PA/SERN NY AND LEAST (SLGHT CHC
TO LO CHC) ON THE LAKE ONTARIO PLAIN.
THE 0-1, 0-3 AND 0-6 KM BULK SHEARS ARE NOT THAT IMPRESSIVE THIS
AFTERNOON RUNNING 15 KNOTS, 20 KNOTS AND 20 KNOTS RESPECTIVELY.
BUT GIVEN CAPES THERE CUD BE A FEW ISOLATED SVR STORMS WITH LARGE
HAIL AND MICROBURST WINDS GIVEN THE DRIER AIR ALOFT. SO WILL CONT
TO MENTION IN HWO FOR THIS AFTERNOON AND EVENING AND FOCUS ON NE
PA TO THE WRN CATSKILLS AND CONCUR WITH SPC MARGINAL RISK.
AFTER CONVECTION DIES DOWN THIS EVENING...WE HAVE SKIES CLEARING
WITH PATCHY FOG DEVELOPING LATE. HOWEVER LATEST RAP SUGGESTS MORE
CONVECTION LATE TONIGHT. OTHER 12Z MODELS SO FAR DO NOT. FOR NOW
WILL KEEP LATE TONIGHT DRY. BUT WILL HAVE TO REASSESS AS MORE
GUIDC COMES IN.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
430 AM UPDATE...
HOT AND HUMID, JUST LIKE SUMMER SHOULD BE. THAT SUMS UP SUNDAY.
DID LITTLE WITH TEMPS, WITH MOST OF THE LOWER ELEVATIONS IN THE
90-92 RANGE, AND ELEVATIONS 84 TO 88. WITH DEWPOINTS NEAR 70, HEAT
INDICES WILL BE IN THE MID TO UPPER 90S, WITH NEAR 100 POSSIBLE IN
THE METRO AREAS OF CNY AND NEPA. EXCELLENT HWO FROM YESTERDAY WAS
KEPT IN TACT FOR THE HEAT THREAT. IN ADDITION FROM JUST 24 HOURS
AGO, THREAT FOR STORMS LATER SUNDAY LOOKS A BIT HIGHER. BEST SHEAR
STILL LOOKS TO BE LATER SUNDAY NIGHT BUT WE SHOULD HAVE MORE OF A
TRIGGER SUNDAY AFTERNOON AND CAPES AGAIN AVERAGE 1000 TO 2000
J/KG.
BOTH THE EURO AND GFS CLEAR US OUT PRETTY QUICKLY MONDAY SO
BESIDES AN EARLY SHOWER, I CLEARED POPS FROM MONDAY AFTERNOON AS
COMFORTABLE AIR SETTLES IN.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
230 PM UPDATE...
MONDAY NIGHT A WEAK RIDGE OF HIGH PRESSURE MOVES IN. MODELS BRING
IN A MODERATE STRENGTH SYSTEM WITH A SFC COLD FRONT AND UPPER
LEVEL TROF TUESDAY. MIDDAY FROPA NOT THE BEST FOR HEATING TO HELP
THE INSTABILITY. TIMING HAS CHANGED ON THIS AND STILL SEVERAL DAYS
OUT SO IT COULD CHANGE AGAIN.
FOLLOWED WPC GUIDANCE TUES NGT ON. BIGGEST CHANGE WAS TO LOWER
TEMPS SEVERAL DEGREES. SO NOW TEMPERATURES AT OR SLIGHTLY BELOW
NORMAL. EURO HAS A DEEPER TROF THAT LASTS LONGER.
SHOWERS MOVE OUT TUESDAY EVENING THEN HIGH PRESSURE BUILDS IN THU
AND LASTS INTO SATURDAY. CANADIAN AND EURO SIMILAR BUT GFS HAS
WEAK SYSTEMS MOVING THROUGH THE AREA THE ENTIRE WEEK.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
130 PM UPDATE...
MAINLY VFR INTO MIDDAY SUNDAY.
UP TO 20Z SOME SHOWERS ITH/BGM COULD CAUSE PERIODS OF MVFR CIGS
AND MAYBE VSBY. THESE SHOWERS SHOULD GET INTO AVP 20 TO 23Z WITH
SIMILAR RESULTS.
CLOUDS SHOULD DIMINISH THIS EVE WITH THE LOSS OF HEATING. WINDS
WILL GO LIGHT SO ELM COULD AGAIN HAVE IFR CONDITIONS NEAR FLIGHT
MINIMUMS 9 TO 12Z. BGM/AVP/ITH SHOULD FALL TO MVFR VSBYS WITH THE
SATURATED LOW LEVELS AND THE RAIN TODAY.
SUNDAY CONVECTION SHOULD START AFTER 18Z. LATE TONIGHT TO SUNDAY
MORNING SOME CONVECTIVE DEBRIS MAKE IT INTO THE THE AREA
ESPECIALLY THE NORTH.
SW WINDS SOUTH AND NW WINDS NORTH AT 10 KTS DROP TO LIGHT AND
VARIABLE OR CALM THIS EVENING AND LAST INTO SUNDAY MORNING. SUNDAY
AFTER 14Z SW WINDS AT 5 TO 10 KTS.
.OUTLOOK...
SUN AFTN THRU TUE...A FEW RESTRICTIONS FROM SCT SHRA-
TSRA...ESPECIALLY WITH FRONTAL PASSAGE LATE SUN AND AGAIN TUE.
WED...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN/HEDEN
NEAR TERM...DJN
SHORT TERM...HEDEN
LONG TERM...TAC
AVIATION...TAC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1101 AM EDT SAT JUL 18 2015
.SYNOPSIS...
ISOLATED TO SCATTERED THUNDERSTORMS WILL DEVELOP THIS AFTERNOON,
WITH THE HIGHEST CHANCES ACROSS NORTHEAST PENNSYLVANIA AND THE
CATSKILLS. AFTER THE THUNDERSTORMS DIE DOWN THIS EVENING A VERY
HUMID AND WARM AIR MASS WILL BE IN PLACE. HIGHS SUNDAY WILL TOP 90
DEGREES IN MANY AREAS WITH HEAT INDICES APPROACHING 100 DEGREES
DUE TO THE HIGH HUMIDITY. THE INCREASE IN HEAT AND HUMIDITY ALONG
WITH A COLD FRONT MAY PRODUCE STRONG STORMS SUNDAY AFTERNOON AND
NIGHT. MORE COMFORTABLE AIR RETURNS TO THE AREA BY EARLY NEXT
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST KBGM RADAR SHOWS JUST A FEW ISOLATED SHRA IN PARTS OF THE
WESTERN CATSKILLS AND EXTREME NE PA AT THIS TIME WITH A FEW
SHRA/TSRA IN THE ALLEGHENIES OF WRN NY AND NC PA. LARGE SCALE
MOSAIC RADAR IMAGERY SHOWS AN MCS MOVING ACRS LAKE MICHIGAN AND
LWR MICHIGAN. THE HRRR...WRF_ARW...WRF_NMM...RAP AND NAM ALL SHOW
THAT THIS MCS WILL DIVE SE AND FALL APART AS DIURNAL HEATING
KICKS IN AND DISRUPTS THE INFLOW INTO THIS FEATURE. MODELS ALSO
SHOW ANOTHER SHORT WAVE PASSING ACRS NY AND PA THIS AFTERNOON
WHICH COULD BE CONVECTIVELY INDUCED BY THIS MCS. IN ADDTN...MODEL
MIXED LAYER CAPES THIS AFTERNOON VARY FROM 3000 TO 4000 J/KG ON
THE LATEST NAM...TO 2000-3000 J/KG ON THE WRF_NMM....TO 1000 TO
2000 J/KG ON THE HRRR AND WRF_ARW. THE GFS HAS AROUND 1000 J/KG.
VISIBLE SATELLITE IMAGERY ALSO SHOWS BREAKS AND DESTABILIZATION
BEGINNING TO TAKE PLACE. THE WATER VAPOR AND 7.4 MICRON IMAGERY
SHOWS A LOT OF DRY AIR ADVECTING OVER NY AND PA AS WELL LATE THIS
MORNING WITH STRG MID-LVL SUBSDC AT PRESENT. AS THIS SMALL SHORT
WAVE WORKS E THIS AFTERNOON THERE WILL BE SOME ASCENT AND ALL HI
RES CONVECTION ALLOWING MODELS POP MOST OF THE CONVECTION AS PER
MODEL RADAR IMAGERY FROM SC NY TO NE PA. SO HAVE HIGHEST POPS THIS
AFTERNOON INTO EARLY EVENING IN NE PA/SERN NY AND LEAST (SLGHT CHC
TO LO CHC) ON THE LAKE ONTARIO PLAIN.
THE 0-1, 0-3 AND 0-6 KM BULK SHEARS ARE NOT THAT IMPRESSIVE THIS
AFTERNOON RUNNING 15 KNOTS, 20 KNOTS AND 20 KNOTS RESPECTIVELY.
BUT GIVEN CAPES THERE CUD BE A FEW ISOLATED SVR STORMS WITH LARGE
HAIL AND MICROBURST WINDS GIVEN THE DRIER AIR ALOFT. SO WILL CONT
TO MENTION IN HWO FOR THIS AFTERNOON AND EVENING AND FOCUS ON NE
PA TO THE WRN CATSKILLS AND CONCUR WITH SPC MARGINAL RISK.
AFTER CONVECTION DIES DOWN THIS EVENING...WE HAVE SKIES CLEARING
WITH PATCHY FOG DEVELOPING LATE. HOWEVER LATEST RAP SUGGESTS MORE
CONVECTION LATE TONIGHT. OTHER 12Z MODELS SO FAR DO NOT. FOR NOW
WILL KEEP LATE TONIGHT DRY. BUT WILL HAVE TO REASSESS AS MORE
GUIDC COMES IN.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
430 AM UPDATE...
HOT AND HUMID, JUST LIKE SUMMER SHOULD BE. THAT SUMS UP SUNDAY.
DID LITTLE WITH TEMPS, WITH MOST OF THE LOWER ELEVATIONS IN THE
90-92 RANGE, AND ELEVATIONS 84 TO 88. WITH DEWPOINTS NEAR 70, HEAT
INDICES WILL BE IN THE MID TO UPPER 90S, WITH NEAR 100 POSSIBLE IN
THE METRO AREAS OF CNY AND NEPA. EXCELLENT HWO FROM YESTERDAY WAS
KEPT IN TACT FOR THE HEAT THREAT. IN ADDITION FROM JUST 24 HOURS
AGO, THREAT FOR STORMS LATER SUNDAY LOOKS A BIT HIGHER. BEST SHEAR
STILL LOOKS TO BE LATER SUNDAY NIGHT BUT WE SHOULD HAVE MORE OF A
TRIGGER SUNDAY AFTERNOON AND CAPES AGAIN AVERAGE 1000 TO 2000
J/KG.
BOTH THE EURO AND GFS CLEAR US OUT PRETTY QUICKLY MONDAY SO
BESIDES AN EARLY SHOWER, I CLEARED POPS FROM MONDAY AFTERNOON AS
COMFORTABLE AIR SETTLES IN.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
3 PM UPDATE...
FOLLOWED WPC GUIDANCE. MINOR CHANGES. IN GENERAL DRY AND AT OR
SLIGHTLY WARMER THAN NORMAL.
NO BIG SYSTEMS WITH WEAK HIGH PRESSURE TUESDAY AND THURSDAY. 20
POPS FOR WEDNESDAY WITH A WEAK FRONT. ANOTHER FRONT DROPS SOUTH
IN THE NW FLOW ALOFT ON FRIDAY WITH CHANCE POPS. MODELS DIFFER ON
THE DETAILS OF THE 2 RAIN MAKERS.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
SHRT WV AND SFC TROF IS TRIGGERING SOME SHWRS AND ISLTD TRWS THIS
MRNG RESULTING IN BRIEF MVFR CIGS AND VSBYS. WV WILL PASS IN THE
NEXT CPL HRS LVG VFR CONDS. SECOND WV WILL TRIGGER SOME SHWRS ARND
MIDDAY WITH PSBL BRIEF LWRG INTO MVFR AS WELL. BALANCE OF THE DAY
WILL CONT VFR CONDS. OVRNGT...LWRD CIGS AND VSBY PSBL IN THE
STABLE CONDS...WITH LIFR PSBL IN ELM IN DENSE FOG.
.OUTLOOK...
SAT THRU MON...A FEW RESTRICTIONS FROM SCT SHRA-
TSRA...ESPECIALLY WITH FRONTAL PASSAGE LATE SUN NGT-EARLY MON.
TUE/WED...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN/HEDEN
NEAR TERM...DJN
SHORT TERM...HEDEN
LONG TERM...TAC
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
745 AM EDT SAT JUL 18 2015
.SYNOPSIS...
SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS
WEEKEND. SOME STORMS MAY BE STRONG WITH GUSTY WINDS AND HEAVY
RAINFALL. BEST CHANCE FOR HEAVY RAIN WILL BE SUNDAY NIGHT AHEAD OF
A COLD FRONT WHICH WILL CROSS THE AREA VERY EARLY MONDAY MORNING.
WARMER THAN NORMAL TEMPERATURES THIS WEEKEND WILL TREND BACK
TOWARDS SEASONAL NORMALS DURING THE WEEK.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AS OF 723 AM EDT SATURDAY...SHOWERS AND THUNDERSTORMS ARE
CURRENTLY MOVING ACROSS NORTHERN VERMONT AND OUT OF OUR AREA. 7 AM
TEMPERATURES WERE GENERALLY IN THE 60S TO AROUND 70 WITH A LOT OF
OVERCAST CLOUD COVER IN PLACE. WITHOUT A LOT OF CLEARING...WILL BE
TOUGH TO GET ENOUGH INSTABILITY FOR SEVERE STORMS. AT THIS POINT
THINK THERE WILL STILL BE SOME AFTERNOON SHOWERS ACROSS
VERMONT...BUT NOT ANTICIPATING ANY SEVERE STORMS. VERY HEAVY RAIN
REMAINS A THREAT WITH PWATS VERY HIGH. ONLY HRRR HAS A DECENT
HANDLE ON CONVECTION ACROSS WESTERN NEW YORK AT THIS TIME. IT
TRACKS THIS ACTIVITY SOUTH OF OUR FORECAST AREA...BUT DOES DEVELOP
SOME SCATTERED SHOWERS ACROSS OUR AREA ANYHOW...DOES NOT LOOK
PARTICULARLY CONVECTIVE...BUT DO EXPECT LIGHTNING AS WE HAVE
ALREADY HAD SOME CONVECTION IN THE EARLY MORNING HOURS TODAY.
STILL FEEL BEST CHANCE FOR CONVECTION WILL BE ACROSS NORTHEASTERN
VERMONT...CLOSEST TO PASSAGE OF SHORTWAVE THIS AFTERNOON AND
EVENING. PREVIOUS DISCUSSION FOLLOWS.
OUR REGION WILL REMAIN IN THE WARM SECTOR TODAY WITH WARM FRONT
NORTH OF OUR AREA AND COLD FRONT STILL OFF TO OUR NORTHWEST.
SHOWERS MOVING ACROSS THE AREA EARLY THIS MORNING WILL PUSH
EASTWARD OUT OF OUR AREA. THERE WILL BE A BREAK IN
PRECIPITATION...AND PROBABLY SOME BREAKS IN THE CLOUDS AS WELL.
ANY SUNSHINE SHOULD HELP TO FURTHER DESTABILIZE THE ENVIRONMENT.
MODELS CONTINUE TO INDICATE MODEST CAPE IN THE AREA. THIS
AFTERNOON WILL SEE PWATS OVER 1.5 INCHES. A STRONG SHORTWAVE
PASSES JUST NORTHEAST OF OUR AREA. FEEL THAT FORCING WITH THIS
FEATURE AND UNSTABLE ENVIRONMENT ALREADY IN PLACE ALONG WITH
SURFACE HEATING WILL FIRE UP SOME STORMS...MAINLY ACROSS OUR
NORTHERN VERMONT ZONES. ANY THUNDERSTORM WILL PRESENT THE
POSSIBILITY OF SOME VERY HEAVY RAIN. THERE`S ALSO SOME DECENT 0-6
KM SHEAR AND HAVE CONTINUED WITH MENTION OF GUSTY WINDS AS
WELL...MAINLY FROM 15Z THRU 02Z.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH MONDAY/...
AS OF 441 AM EDT SATURDAY...TONIGHT WILL BRING A SHORT BREAK IN
THE THUNDERSTORM ACTION BEFORE ANOTHER ROUND ON SUNDAY.
TEMPERATURES WILL BE PRETTY MILD OVERNIGHT WITH AMPLE CLOUD COVER
IN PLACE STILL. ANY SHOWERS REMAINING WILL DISSIPATE WITH LOSS OF
DAYTIME HEATING AND SHORTWAVE ENERGY MOVING PAST OUR AREA. CAN
POTENTIALLY SEE SOME CLEARING BY SUNDAY MORNING WHICH WILL ADD TO
INSTABILITY FOR SHOWERS AND THUNDERSTORMS SUNDAY AFTERNOON. PWATS
STILL VERY HIGH...EVEN NEARING 2 INCHES ON SUNDAY AFTERNOON. NOT
MUCH OF A SURFACE FEATURE THOUGH...COLD FRONT WILL STILL BE WELL
WEST OF OUR FORECAST AREA. TEMPERATURES WILL BE WARMER ON
SUNDAY...EDGING INTO THE MID 80S ACROSS MUCH OF THE AREA. MODELS
ONCE AGAIN BRING SOME DECENT CAPE INTO OUR AREA. THERE WILL BE
LESS SHEAR SUNDAY THAN THERE WAS TODAY THOUGH. SHOWERS WILL
CONTINUE INTO THE OVERNIGHT AS COLD FRONT APPROACHES AND CROSSES
THE AREA EARLY MONDAY MORNING. SUNDAY NIGHT MAY ACTUALLY BE THE
BEST CHANCE FOR ANY WIDESPREAD PRECIPITATION IN THE SHORT TERM.
HAVE MENTIONED LIKELY POPS. HEAVY RAIN CONTINUES TO BE A
POSSIBILITY. MODELS ARE NOW SHOWING A QUICKER EXIT FOR THE SHOWERS
MONDAY MORNING AND MONDAY LOOKS TO BE MOSTLY DRY...HAVE LOWERED
POPS. TEMPERATURES WILL BE NEAR SEASONAL NORMALS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 419 AM EDT SATURDAY...MAINLY DRY CONDITIONS EXPECTED MONDAY
NIGHT WITH WEAK AREA OF HIGH PRESSURE OVER THE REGION. CHANCE OF
SHOWERS INCREASES DURING TUESDAY AS SHORTWAVE TROUGH TROUGH AND
ASSOCIATED SURFACE COLD FRONT ADVANCE RAPIDLY EAST FROM THE GREAT
LAKES. SOME WEAK INSTABILITY INDICATED...SO HAVE INCLUDED SLIGHT
CHANCE THUNDER. CLOUDS WILL PREVENT TEMPS FROM RISING MUCH ABOVE
SEASONAL NORMS...WITH HIGHS MAINLY IN THE LOWER 80S. SHOWERS TAPER
OFF TUESDAY NIGHT WITH PASSAGE OF FRONT AND TROUGH. DURING
WEDNESDAY...ANOTHER DISTURBANCE IN THE FLOW ALOFT COMBINED WITH
INSTABILITY GENERATED FROM DAYTIME HEATING WILL RESULT IN CHANCE
OF A FEW MORE AFTERNOON SHOWERS. SURFACE HIGH PRESSURE BUILDS IN
FOR LATER IN THE WEEK. WITH LARGE UPPER TROUGH PARKED OVER EASTERN
CANADA HOWEVER...WE WILL SEE SOME CLOUDS AND THE CHANCE FOR A FEW
LIGHT SHOWERS OR SPRINKLES OVER THE HIGHER TERRAIN. TEMPERATURES
ARE EXPECTED TO BE WITHIN A FEW DEGREES OF SEASONAL NORMS DURING
THE MID-LATE WEEK PERIOD. EXPECT HIGHS IN THE UPPER 70S AND LOWER
80S WITH LOWS IN THE MID 50S TO LOWER 60S.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 12Z SUNDAY...SCATTERED SHOWERS WILL TAPER OFF FROM WEST
TO EAST THROUGH 14Z. VISIBILITIES LOWERING TO MVFR AT TIMES IN
PRECIPITATION AND SOME LIGHT FOG/MIST. CEILINGS MAINLY MVFR WITH
SOME IFR AT SLK/MPV THIS MORNING. CEILINGS IMPROVE TO MVFR ALL
SITES BY 16Z AND TO MAINLY VFR BY 18Z. SCATTERED SHOWERS AND
THUNDERSTORMS POSSIBLE THIS AFTERNOON...MAINLY FROM CHAMPLAIN
VALLEY EAST. SOUTHERLY WINDS 5-10 KNOTS TODAY EXCEPT GUSTING
AROUND 20 KNOTS IN CHAMPLAIN VALLEY. WINDS BECOME LIGHT AND
VARIABLE TONIGHT. EXPECT SOME MVFR CONDITIONS TO DEVELOP AFTER
04Z WITH POSSIBLE IFR IN FOG AT MPV/SLK.
OUTLOOK 12Z SUNDAY THROUGH WEDNESDAY...
12Z SUN - 18Z SUN...MAINLY VFR.
18Z SUN - 12Z MON...VFR/MVFR IN PERIODS OF SHOWERS AND THUNDERSTORMS.
12Z MON - 12Z TUE...MAINLY VFR. EARLY MORNING IFR FOG PSBL MPV/SLK.
12Z TUE - 00Z THU...MAINLY VFR. CHANCE AFTERNOON
SHOWERS/THUNDERSTORMS BOTH DAYS WITH BRIEF MVFR POSSIBLE.
&&
.MARINE...
AS OF 730 AM EDT SATURDAY...A LAKE WIND ADVISORY IS CURRENTLY IN
EFFECT. STRONG SOUTHERLY WINDS 25-30 KNOTS ARE EXPECTED OVER LAKE
CHAMPLAIN THROUGH AROUND NOON. WIND WAVES ARE EXPECTED TO REACH
2-4 FEET DURING THIS EVENT.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...NEILES
NEAR TERM...NEILES
SHORT TERM...NEILES
LONG TERM...RJS
AVIATION...RJS
MARINE...NEILES
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
733 AM EDT SAT JUL 18 2015
.SYNOPSIS...
SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS
WEEKEND. SOME STORMS MAY BE STRONG WITH GUSTY WINDS AND HEAVY
RAINFALL. BEST CHANCE FOR HEAVY RAIN WILL BE SUNDAY NIGHT AHEAD OF
A COLD FRONT WHICH WILL CROSS THE AREA VERY EARLY MONDAY MORNING.
WARMER THAN NORMAL TEMPERATURES THIS WEEKEND WILL TREND BACK
TOWARDS SEASONAL NORMALS DURING THE WEEK.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AS OF 723 AM EDT SATURDAY...SHOWERS AND THUNDERSTORMS ARE
CURRENTLY MOVING ACROSS NORTHERN VERMONT AND OUT OF OUR AREA. 7 AM
TEMPERATURES WERE GENERALLY IN THE 60S TO AROUND 70 WITH A LOT OF
OVERCAST CLOUD COVER IN PLACE. WITHOUT A LOT OF CLEARING...WILL BE
TOUGH TO GET ENOUGH INSTABILITY FOR SEVERE STORMS. AT THIS POINT
THINK THERE WILL STILL BE SOME AFTERNOON SHOWERS ACROSS
VERMONT...BUT NOT ANTICIPATING ANY SEVERE STORMS. VERY HEAVY RAIN
REMAINS A THREAT WITH PWATS VERY HIGH. ONLY HRRR HAS A DECENT
HANDLE ON CONVECTION ACROSS WESTERN NEW YORK AT THIS TIME. IT
TRACKS THIS ACTIVITY SOUTH OF OUR FORECAST AREA...BUT DOES DEVELOP
SOME SCATTERED SHOWERS ACROSS OUR AREA ANYHOW...DOES NOT LOOK
PARTICULARLY CONVECTIVE...BUT DO EXPECT LIGHTNING AS WE HAVE
ALREADY HAD SOME CONVECTION IN THE EARLY MORNING HOURS TODAY.
STILL FEEL BEST CHANCE FOR CONVECTION WILL BE ACROSS NORTHEASTERN
VERMONT...CLOSEST TO PASSAGE OF SHORTWAVE THIS AFTERNOON AND
EVENING. PREVIOUS DISCUSSION FOLLOWS.
OUR REGION WILL REMAIN IN THE WARM SECTOR TODAY WITH WARM FRONT
NORTH OF OUR AREA AND COLD FRONT STILL OFF TO OUR NORTHWEST.
SHOWERS MOVING ACROSS THE AREA EARLY THIS MORNING WILL PUSH
EASTWARD OUT OF OUR AREA. THERE WILL BE A BREAK IN
PRECIPITATION...AND PROBABLY SOME BREAKS IN THE CLOUDS AS WELL.
ANY SUNSHINE SHOULD HELP TO FURTHER DESTABILIZE THE ENVIRONMENT.
MODELS CONTINUE TO INDICATE MODEST CAPE IN THE AREA. THIS
AFTERNOON WILL SEE PWATS OVER 1.5 INCHES. A STRONG SHORTWAVE
PASSES JUST NORTHEAST OF OUR AREA. FEEL THAT FORCING WITH THIS
FEATURE AND UNSTABLE ENVIRONMENT ALREADY IN PLACE ALONG WITH
SURFACE HEATING WILL FIRE UP SOME STORMS...MAINLY ACROSS OUR
NORTHERN VERMONT ZONES. ANY THUNDERSTORM WILL PRESENT THE
POSSIBILITY OF SOME VERY HEAVY RAIN. THERE`S ALSO SOME DECENT 0-6
KM SHEAR AND HAVE CONTINUED WITH MENTION OF GUSTY WINDS AS
WELL...MAINLY FROM 15Z THRU 02Z.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH MONDAY/...
AS OF 441 AM EDT SATURDAY...TONIGHT WILL BRING A SHORT BREAK IN
THE THUNDERSTORM ACTION BEFORE ANOTHER ROUND ON SUNDAY.
TEMPERATURES WILL BE PRETTY MILD OVERNIGHT WITH AMPLE CLOUD COVER
IN PLACE STILL. ANY SHOWERS REMAINING WILL DISSIPATE WITH LOSS OF
DAYTIME HEATING AND SHORTWAVE ENERGY MOVING PAST OUR AREA. CAN
POTENTIALLY SEE SOME CLEARING BY SUNDAY MORNING WHICH WILL ADD TO
INSTABILITY FOR SHOWERS AND THUNDERSTORMS SUNDAY AFTERNOON. PWATS
STILL VERY HIGH...EVEN NEARING 2 INCHES ON SUNDAY AFTERNOON. NOT
MUCH OF A SURFACE FEATURE THOUGH...COLD FRONT WILL STILL BE WELL
WEST OF OUR FORECAST AREA. TEMPERATURES WILL BE WARMER ON
SUNDAY...EDGING INTO THE MID 80S ACROSS MUCH OF THE AREA. MODELS
ONCE AGAIN BRING SOME DECENT CAPE INTO OUR AREA. THERE WILL BE
LESS SHEAR SUNDAY THAN THERE WAS TODAY THOUGH. SHOWERS WILL
CONTINUE INTO THE OVERNIGHT AS COLD FRONT APPROACHES AND CROSSES
THE AREA EARLY MONDAY MORNING. SUNDAY NIGHT MAY ACTUALLY BE THE
BEST CHANCE FOR ANY WIDESPREAD PRECIPITATION IN THE SHORT TERM.
HAVE MENTIONED LIKELY POPS. HEAVY RAIN CONTINUES TO BE A
POSSIBILITY. MODELS ARE NOW SHOWING A QUICKER EXIT FOR THE SHOWERS
MONDAY MORNING AND MONDAY LOOKS TO BE MOSTLY DRY...HAVE LOWERED
POPS. TEMPERATURES WILL BE NEAR SEASONAL NORMALS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 419 AM EDT SATURDAY...MAINLY DRY CONDITIONS EXPECTED MONDAY
NIGHT WITH WEAK AREA OF HIGH PRESSURE OVER THE REGION. CHANCE OF
SHOWERS INCREASES DURING TUESDAY AS SHORTWAVE TROUGH TROUGH AND
ASSOCIATED SURFACE COLD FRONT ADVANCE RAPIDLY EAST FROM THE GREAT
LAKES. SOME WEAK INSTABILITY INDICATED...SO HAVE INCLUDED SLIGHT
CHANCE THUNDER. CLOUDS WILL PREVENT TEMPS FROM RISING MUCH ABOVE
SEASONAL NORMS...WITH HIGHS MAINLY IN THE LOWER 80S. SHOWERS TAPER
OFF TUESDAY NIGHT WITH PASSAGE OF FRONT AND TROUGH. DURING
WEDNESDAY...ANOTHER DISTURBANCE IN THE FLOW ALOFT COMBINED WITH
INSTABILITY GENERATED FROM DAYTIME HEATING WILL RESULT IN CHANCE
OF A FEW MORE AFTERNOON SHOWERS. SURFACE HIGH PRESSURE BUILDS IN
FOR LATER IN THE WEEK. WITH LARGE UPPER TROUGH PARKED OVER EASTERN
CANADA HOWEVER...WE WILL SEE SOME CLOUDS AND THE CHANCE FOR A FEW
LIGHT SHOWERS OR SPRINKLES OVER THE HIGHER TERRAIN. TEMPERATURES
ARE EXPECTED TO BE WITHIN A FEW DEGREES OF SEASONAL NORMS DURING
THE MID-LATE WEEK PERIOD. EXPECT HIGHS IN THE UPPER 70S AND LOWER
80S WITH LOWS IN THE MID 50S TO LOWER 60S.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 06Z SUNDAY...WIDESPREAD SHOWERS ACROSS THE REGION WILL
TAPER OFF FROM WEST TO EAST 08Z-12Z. VISIBILITIES LOWERING TO MVFR
AT TIMES IN PRECIPITATION AND SOME LIGHT FOG/MIST. CEILINGS
LOWERING THROUGH THE NIGHT TO MVFR ALL SITES WITH IFR POSSIBLE
SLK/MPV AND POSSIBLY MSS. CEILINGS IMPROVE TO MVFR ALL SITES 12Z-
16Z AND TO MAINLY VFR BY 18Z. SCATTERED SHOWERS AND THUNDERSTORMS
POSSIBLE THIS AFTERNOON...MAINLY FROM CHAMPLAIN VALLEY EAST.
SOUTHERLY WINDS 5-10 KNOTS THRU 12Z AND UP TO 15-20 KNOTS IN
CHAMPLAIN VALLEY AFT 12Z SAT.
OUTLOOK 06Z SUNDAY THROUGH WEDNESDAY...
06Z SUN - 18Z SUN...MAINLY VFR. EARLY MORNING IFR FOG PSBL
KMPV/KSLK. 18Z SUN - 18Z MON...VFR/MVFR IN PERIODS OF SHOWERS AND
THUNDERSTORMS. 18Z MON - 12Z TUE...MAINLY VFR. EARLY MORNING IFR
FOG PSBL KMPV/KSLK. 12Z TUE - 00Z THU...MAINLY VFR. CHANCE
AFTERNOON SHOWERS/THUNDERSTORMS BOTH DAYS WITH BRIEF MVFR
POSSIBLE..
&&
.MARINE...
AS OF 730 AM EDT SATURDAY...A LAKE WIND ADVISORY IS CURRENTLY IN
EFFECT. STRONG SOUTHERLY WINDS 25-30 KNOTS ARE EXPECTED OVER LAKE
CHAMPLAIN THROUGH AROUND NOON. WIND WAVES ARE EXPECTED TO REACH
2-4 FEET DURING THIS EVENT.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...NEILES
NEAR TERM...NEILES
SHORT TERM...NEILES
LONG TERM...RJS
AVIATION...RJS
MARINE...NEILES
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
420 AM EDT SAT JUL 18 2015
.SYNOPSIS...
EXPECT AN ACTIVE WEEKEND OF SHOWERS WITH EMBEDDED THUNDERSTORMS
WITH THE POTENTIAL FOR HEAVY RAINFALL. THE HEAVIEST RAIN WILL FALL
AHEAD OF A COLD FRONT THAT MOVES THROUGH THE AREA MONDAY. ANOTHER
FRONT WILL BRING A CHANCE OF SHOWERS AGAIN MID WEEK. AHEAD OF THE
COLD FRONT THIS WEEKEND HOT AND HUMID TEMPERATURES ARE EXPECTED
WITH TEMPERATURES APPROACHING 90 DEGREES IN THE VALLEYS.
TEMPERATURES BEHIND THE FRONT WILL TREND BACK TOWARDS MORE
SEASONABLE HIGHS NEAR 80 AND LOWS NEAR 60.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 1241 AM EDT SATURDAY...THOUGH VIRGA OR VERY LIGHT SHOWERS
PREVAIL ACROSS MUCH OF VERMONT, STEADIER BAND OF RAIN HAS
DEVELOPED EXTENDING ALONG A MSS-SLK-GFL LINE AND WILL MOVE
EASTWARD INTO THE CHAMPLAIN VALLEY BEFORE MIDNIGHT, AND ACROSS THE
REST OF VERMONT AFTER MIDNIGHT. IN THE WAKE OF THIS WARM- FRONTAL
RAIN IS MORE SPOTTY, SCATTERED SHOWERS. UPSTREAM DETROIT RAOB
SHOWS SOME STEEPER MID- LEVEL LAPSE RATES IN A BROADLY CYCLONIC
WEST FLOW. THE LATEST RAP FORECAST PICKS UP ON THESE STEEPER LAPSE
RATES IN ITS DEPICTION OF WEAK NEGATIVE SHOWALTER INDICES
ADVECTING IN THROUGH THE OVERNIGHT. REGARDING POPS AND WEATHER,
I`VE ADDED IN SLIGHT CHANCE THUNDER TO THE GRIDS AFTER MIDNIGHT
ONCE THE MORE FOCUSED WARM FRONTAL RAIN LIFTS EAST.
CURRENT TEMPS GENERALLY IN THE MID 60S TO LOW 70S, WITH SOME
SLIGHT INCREASE IN DEWPOINTS SINCE EARLY EVENING - INTO THE UPPER
50S TO MID 60S. TEMPS WILL BE VERY SLOW TO FALL GIVEN SOUTH
WINDS, WARM ADVECTION REGIME AND OVERCAST SKIES. DEWPOINTS WILL
ALSO GRADUALLY BE ON THE CLIMB WITH MANY AREAS LIKELY TO BE IN THE
60S BY SUNRISE. SO ITS GOING TO BE AN INCREASINGLY MORE HUMID
NIGHT, WITH LOWS IN THE 60S.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH MONDAY/...
AS OF 343 PM EDT FRIDAY...TOMORROW IS STILL EXPECTED TO BE AN
ACTIVE DAY WITH SHOWERS AND THUNDERSTORMS STILL PROGRESSING ACROSS
THE REGION BEHIND THE WARM FRONT. THE WARM ADVECTION SHOWERS
SHOULD COME TO AN END SOME TIME IN THE MORNING WITH A CHANCE FOR
SOME LIGHT CLEARING. THE BEST CHANCE FOR CLEARING WILL BE ACROSS
NORTHERN NEW YORK AND NORTHERN VERMONT. AS THE SOUTHERLY WINDS
CONTINUE TO BRING IN MORE WARMER MOIST AIR EXPECT TOMORROW TO BE
QUITE MUGGY WITH SURFACE DEWPOINTS INCREASING TO THE UPPER 60S TO
NEAR 70 IN THE VALLEYS. THE HIGH DEW POINTS WILL COMBINE WITH
TEMPS AROUND 80 TO GENERATE 1500-2000 J/KG OF CAPE ALONG THE
INTERNATIONAL BORDER. WITH SURFACE CONVERGENCE INCREASING AS A
UPPER LEVEL SHORTWAVE VORT CROSSES THE NORTH COUNTRY EXPECT THERE
TO BE POTENTIAL FOR SOME STRONGER STORMS TO DEVELOP. I CONTINUED
THE MENTION OF HEAVY RAIN AND POTENTIAL FOR GUSTY WINDS IN THE
FORECAST BASED ON MODERATE 0-6KM SHEAR OF 30-40KTS AND THE
ENHANCED SURFACE AND ELEVATED INSTABILITY. EXPECT SCATTERED
SOUTHWESTWARD MOVING STORMS TO SLOWLY MOVE ACROSS THE AREA IN THE
AFTERNOON WITH RELATIVELY LIGHT CORFIDI VECTORS NORTHWEST AT 5-10KNOTS.
GIVEN THE LIGHT DIRECTIONAL WINDS AS THE PWATS INCREASE TO 2.0"
TOMORROW SOME OF THE STORMS COULD PRODUCE HEAVY RAINFALL AND
PRODUCE PONDING IN AREAS OF POOR DRAINAGE AND IN URBAN AREAS.
AS WE LOSE THE DIURNAL HEATING SATURDAY NIGHT EXPECT SHOWERS TO
DISSIPATE OVERNIGHT BEFORE FIRING AGAIN IN EARNEST BY MID MORNING
SUNDAY. SUNDAY WILL SEE CONTINUED HIGH DEWPOINTS WITH PLENTY OF
LOW LEVEL MOISTURE AND AS THE SHORTWAVE CLEARS THE REGION ON
SATURDAY EVENING EXPECT BETTER CLEARING ON SUNDAY MORNING. THE
RESULT OF THAT WILL BE AN EVEN BETTER CHANCE FOR SLOW MOVING
SHOWERS ON SUNDAY WITH DAYTIME TEMPERATURES IN THE UPPER 80S
APPROACHING NEAR 90 DEGREES IN THE SAINT LAWRENCE AND CHAMPLAIN
VALLEY. WITH WEAK SHEAR IN THE 0-6KM PROFILE I ANTICIPATE THE
THREAT FOR STRONG STORMS TO BE MINOR BUT WITH THE SURFACE
INSTABILITY STILL QUITE LARGE RANGING FROM 2000-3000 J/KG CAPE
OVER NORTHERN NEW YORK BY MID DAY ON SUNDAY STRONG TO SEVERE
STORMS CANT BE RULED OUT. DECENT LAPSE RATES IN THE 700-500MB
LAYER SHOW EVIDENCE OF A WELL DEVELOPED EML MOVING INTO THE AREA
SO THE THREAT OF HEAVY RAIN WILL CONTINUE SUNDAY AFTERNOON INTO
SUNDAY EVENING.
PWATS WILL BE 1 TO 2 STANDARD DEVIATIONS ABOVE NORMAL INTO SUNDAY
EVENING SO THE THREAT OF ISOLATE FLASH FLOODING IS POSSIBLE AND
THUS I WENT AHEAD AND UPDATED THE FORECAST TO SHOW THE ENHANCED
WORDING OF HEAVY RAINFALL FOR SUNDAY AFTERNOON AND SUNDAY EVENING
AHEAD OF THE COLD FRONT THAT PASSES THROUGH ON MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 419 AM EDT SATURDAY...MAINLY DRY CONDITIONS EXPECTED MONDAY
NIGHT WITH WEAK AREA OF HIGH PRESSURE OVER THE REGION. CHANCE OF
SHOWERS INCREASES DURING TUESDAY AS SHORTWAVE TROUGH TROUGH AND
ASSOCIATED SURFACE COLD FRONT ADVANCE RAPIDLY EAST FROM THE GREAT
LAKES. SOME WEAK INSTABILITY INDICATED...SO HAVE INCLUDED SLIGHT
CHANCE THUNDER. CLOUDS WILL PREVENT TEMPS FROM RISING MUCH ABOVE
SEASONAL NORMS...WITH HIGHS MAINLY IN THE LOWER 80S. SHOWERS TAPER
OFF TUESDAY NIGHT WITH PASSAGE OF FRONT AND TROUGH. DURING
WEDNESDAY...ANOTHER DISTURBANCE IN THE FLOW ALOFT COMBINED WITH
INSTABILITY GENERATED FROM DAYTIME HEATING WILL RESULT IN CHANCE
OF A FEW MORE AFTERNOON SHOWERS. SURFACE HIGH PRESSURE BUILDS IN
FOR LATER IN THE WEEK. WITH LARGE UPPER TROUGH PARKED OVER EASTERN
CANADA HOWEVER...WE WILL SEE SOME CLOUDS AND THE CHANCE FOR A FEW
LIGHT SHOWERS OR SPRINKLES OVER THE HIGHER TERRAIN. TEMPERATURES
ARE EXPECTED TO BE WITHIN A FEW DEGREES OF SEASONAL NORMS DURING
THE MID-LATE WEEK PERIOD. EXPECT HIGHS IN THE UPPER 70S AND LOWER
80S WITH LOWS IN THE MID 50S TO LOWER 60S.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 06Z SUNDAY...WIDESPREAD SHOWERS ACROSS THE REGION WILL
TAPER OFF FROM WEST TO EAST 08Z-12Z. VISIBILITIES LOWERING TO MVFR
AT TIMES IN PRECIPITATION AND SOME LIGHT FOG/MIST. CEILINGS
LOWERING THROUGH THE NIGHT TO MVFR ALL SITES WITH IFR POSSIBLE
SLK/MPV AND POSSIBLY MSS. CEILINGS IMPROVE TO MVFR ALL SITES
12Z-16Z AND TO MAINLY VFR BY 18Z. SCATTERED SHOWERS AND
THUNDERSTORMS POSSIBLE THIS AFTERNOON...MAINLY FROM CHAMPLAIN
VALLEY EAST. SOUTHERLY WINDS 5-10 KNOTS THRU 12Z AND UP TO 15-20
KNOTS IN CHAMPLAIN VALLEY AFT 12Z SAT.
OUTLOOK 06Z SUNDAY THROUGH WEDNESDAY...
06Z SUN - 18Z SUN...MAINLY VFR. EARLY MORNING IFR FOG PSBL KMPV/KSLK.
18Z SUN - 18Z MON...VFR/MVFR IN PERIODS OF SHOWERS AND THUNDERSTORMS.
18Z MON - 12Z TUE...MAINLY VFR. EARLY MORNING IFR FOG PSBL KMPV/KSLK.
12Z TUE - 00Z THU...MAINLY VFR. CHANCE AFTERNOON SHOWERS/THUNDERSTORMS
BOTH DAYS WITH BRIEF MVFR POSSIBLE..
&&
.MARINE...
AS OF 252 PM EDT FRIDAY...A LAKE WIND ADVISORY IS CURRENTLY IN
EFFECT. STRONG SOUTHERLY WINDS 25-30 KNOTS ARE EXPECTED OVER LAKE
CHAMPLAIN AFTER 8PM LASTING THROUGH THE OVERNIGHT HOURS. WIND
WAVES ARE EXPECTED TO REACH 2-4 FEET DURING THIS EVENT.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DEAL
NEAR TERM...NEILES/LOCONTO
SHORT TERM...DEAL
LONG TERM...RJS
AVIATION...RJS
MARINE...MV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
159 AM EDT SAT JUL 18 2015
.SYNOPSIS...
EXPECT AN ACTIVE WEEKEND OF SHOWERS WITH EMBEDDED THUNDERSTORMS
WITH THE POTENTIAL FOR HEAVY RAINFALL. THE HEAVIEST RAIN WILL FALL
AHEAD OF A COLD FRONT THAT MOVES THROUGH THE AREA MONDAY. ANOTHER
FRONT WILL BRING A CHANCE OF SHOWERS AGAIN MID WEEK. AHEAD OF THE
COLD FRONT THIS WEEKEND HOT AND HUMID TEMPERATURES ARE EXPECTED
WITH TEMPERATURES APPROACHING 90 DEGREES IN THE VALLEYS.
TEMPERATURES BEHIND THE FRONT WILL TREND BACK TOWARDS MORE
SEASONABLE HIGHS NEAR 80 AND LOWS NEAR 60.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 1241 AM EDT SATURDAY...THOUGH VIRGA OR VERY LIGHT SHOWERS
PREVAIL ACROSS MUCH OF VERMONT, STEADIER BAND OF RAIN HAS
DEVELOPED EXTENDING ALONG A MSS-SLK-GFL LINE AND WILL MOVE
EASTWARD INTO THE CHAMPLAIN VALLEY BEFORE MIDNIGHT, AND ACROSS THE
REST OF VERMONT AFTER MIDNIGHT. IN THE WAKE OF THIS WARM- FRONTAL
RAIN IS MORE SPOTTY, SCATTERED SHOWERS. UPSTREAM DETROIT RAOB
SHOWS SOME STEEPER MID- LEVEL LAPSE RATES IN A BROADLY CYCLONIC
WEST FLOW. THE LATEST RAP FORECAST PICKS UP ON THESE STEEPER LAPSE
RATES IN ITS DEPICTION OF WEAK NEGATIVE SHOWALTER INDICES
ADVECTING IN THROUGH THE OVERNIGHT. REGARDING POPS AND WEATHER,
I`VE ADDED IN SLIGHT CHANCE THUNDER TO THE GRIDS AFTER MIDNIGHT
ONCE THE MORE FOCUSED WARM FRONTAL RAIN LIFTS EAST.
CURRENT TEMPS GENERALLY IN THE MID 60S TO LOW 70S, WITH SOME
SLIGHT INCREASE IN DEWPOINTS SINCE EARLY EVENING - INTO THE UPPER
50S TO MID 60S. TEMPS WILL BE VERY SLOW TO FALL GIVEN SOUTH
WINDS, WARM ADVECTION REGIME AND OVERCAST SKIES. DEWPOINTS WILL
ALSO GRADUALLY BE ON THE CLIMB WITH MANY AREAS LIKELY TO BE IN THE
60S BY SUNRISE. SO ITS GOING TO BE AN INCREASINGLY MORE HUMID
NIGHT, WITH LOWS IN THE 60S.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH SUNDAY NIGHT/...
AS OF 343 PM EDT FRIDAY...TOMORROW IS STILL EXPECTED TO BE AN
ACTIVE DAY WITH SHOWERS AND THUNDERSTORMS STILL PROGRESSING ACROSS
THE REGION BEHIND THE WARM FRONT. THE WARM ADVECTION SHOWERS
SHOULD COME TO AN END SOME TIME IN THE MORNING WITH A CHANCE FOR
SOME LIGHT CLEARING. THE BEST CHANCE FOR CLEARING WILL BE ACROSS
NORTHERN NEW YORK AND NORTHERN VERMONT. AS THE SOUTHERLY WINDS
CONTINUE TO BRING IN MORE WARMER MOIST AIR EXPECT TOMORROW TO BE
QUITE MUGGY WITH SURFACE DEWPOINTS INCREASING TO THE UPPER 60S TO
NEAR 70 IN THE VALLEYS. THE HIGH DEW POINTS WILL COMBINE WITH
TEMPS AROUND 80 TO GENERATE 1500-2000 J/KG OF CAPE ALONG THE
INTERNATIONAL BORDER. WITH SURFACE CONVERGENCE INCREASING AS A
UPPER LEVEL SHORTWAVE VORT CROSSES THE NORTH COUNTRY EXPECT THERE
TO BE POTENTIAL FOR SOME STRONGER STORMS TO DEVELOP. I CONTINUED
THE MENTION OF HEAVY RAIN AND POTENTIAL FOR GUSTY WINDS IN THE
FORECAST BASED ON MODERATE 0-6KM SHEAR OF 30-40KTS AND THE
ENHANCED SURFACE AND ELEVATED INSTABILITY. EXPECT SCATTERED
SOUTHWESTWARD MOVING STORMS TO SLOWLY MOVE ACROSS THE AREA IN THE
AFTERNOON WITH RELATIVELY LIGHT CORFIDI VECTORS NORTHWEST AT 5-10KNOTS.
GIVEN THE LIGHT DIRECTIONAL WINDS AS THE PWATS INCREASE TO 2.0"
TOMORROW SOME OF THE STORMS COULD PRODUCE HEAVY RAINFALL AND
PRODUCE PONDING IN AREAS OF POOR DRAINAGE AND IN URBAN AREAS.
AS WE LOSE THE DIURNAL HEATING SATURDAY NIGHT EXPECT SHOWERS TO
DISSIPATE OVERNIGHT BEFORE FIRING AGAIN IN EARNEST BY MID MORNING
SUNDAY. SUNDAY WILL SEE CONTINUED HIGH DEWPOINTS WITH PLENTY OF
LOW LEVEL MOISTURE AND AS THE SHORTWAVE CLEARS THE REGION ON
SATURDAY EVENING EXPECT BETTER CLEARING ON SUNDAY MORNING. THE
RESULT OF THAT WILL BE AN EVEN BETTER CHANCE FOR SLOW MOVING
SHOWERS ON SUNDAY WITH DAYTIME TEMPERATURES IN THE UPPER 80S
APPROACHING NEAR 90 DEGREES IN THE SAINT LAWRENCE AND CHAMPLAIN
VALLEY. WITH WEAK SHEAR IN THE 0-6KM PROFILE I ANTICIPATE THE
THREAT FOR STRONG STORMS TO BE MINOR BUT WITH THE SURFACE
INSTABILITY STILL QUITE LARGE RANGING FROM 2000-3000 J/KG CAPE
OVER NORTHERN NEW YORK BY MID DAY ON SUNDAY STRONG TO SEVERE
STORMS CANT BE RULED OUT. DECENT LAPSE RATES IN THE 700-500MB
LAYER SHOW EVIDENCE OF A WELL DEVELOPED EML MOVING INTO THE AREA
SO THE THREAT OF HEAVY RAIN WILL CONTINUE SUNDAY AFTERNOON INTO
SUNDAY EVENING.
PWATS WILL BE 1 TO 2 STANDARD DEVIATIONS ABOVE NORMAL INTO SUNDAY
EVENING SO THE THREAT OF ISOLATE FLASH FLOODING IS POSSIBLE AND
THUS I WENT AHEAD AND UPDATED THE FORECAST TO SHOW THE ENHANCED
WORDING OF HEAVY RAINFALL FOR SUNDAY AFTERNOON AND SUNDAY EVENING
AHEAD OF THE COLD FRONT THAT PASSES THROUGH ON MONDAY.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 320 PM EDT FRIDAY...SURFACE COLD FRONT SHIFTING THROUGH THE
FORECAST AREA MONDAY MORNING WITH PRECIPITATION EXITING FROM WEST
TO EAST THROUGH THE DAY. MAX TEMPS WILL BE TRICKY WITH UNCERTAINTY
IN THE EXACT FROPA TIMING, BUT GIVEN THE WARM OVERNIGHT TEMPERATURES
ANY CLEARING IN THE AFTERNOON SHOULD ALLOW TEMPS TO REBOUND INTO
THE LOWER 80S.
DRIER CONDITIONS RETURN FOR MONDAY NIGHT THROUGH TUESDAY NIGHT AS A
WEAK RIDGE OF HIGH PRESSURE MOVES ACROSS THE AREA. A FEW WEAK
DISTURBANCES IN FLOW ALOFT COMBINED WITH SOME AFTERNOON INSTABILITY
MAY BE ENOUGH TO PRODUCE SOME SHOWERS OVER THE HIGHER TERRAIN
TUESDAY/WEDNESDAY, BUT OTHERWISE DRY WEATHER IS EXPECTED THROUGH THE
END OF THE WORK WEEK. TEMPS WILL RUN RIGHT AROUND NORMAL, MAYBE JUST
A FEW DEGREES ABOVE WITH HIGHS GENERALLY IN THE UPPER 70S TO MID 80S
AND LOWS IN THE MID 50S TO LOW 60S.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 06Z SUNDAY...WIDESPREAD SHOWERS ACROSS THE REGION WILL
TAPER OFF FROM WEST TO EAST 08Z-12Z. VISIBILITIES LOWERING TO MVFR
AT TIMES IN PRECIPITATION AND SOME LIGHT FOG/MIST. CEILINGS
LOWERING THROUGH THE NIGHT TO MVFR ALL SITES WITH IFR POSSIBLE
SLK/MPV AND POSSIBLY MSS. CEILINGS IMPROVE TO MVFR ALL SITES
12Z-16Z AND TO MAINLY VFR BY 18Z. SCATTERED SHOWERS AND
THUNDERSTORMS POSSIBLE THIS AFTERNOON...MAINLY FROM CHAMPLAIN
VALLEY EAST. SOUTHERLY WINDS 5-10 KNOTS THRU 12Z AND UP TO 15-20
KNOTS IN CHAMPLAIN VALLEY AFT 12Z SAT.
OUTLOOK 06Z SUNDAY THROUGH WEDNESDAY...
06Z SUN - 18Z SUN...MAINLY VFR. EARLY MORNING IFR FOG PSBL KMPV/KSLK.
18Z SUN - 18Z MON...VFR/MVFR IN PERIODS OF SHOWERS AND THUNDERSTORMS.
18Z MON - 12Z TUE...MAINLY VFR. EARLY MORNING IFR FOG PSBL KMPV/KSLK.
12Z TUE - 00Z THU...MAINLY VFR. CHANCE AFTERNOON SHOWERS/THUNDERSTORMS
BOTH DAYS WITH BRIEF MVFR POSSIBLE..
&&
.MARINE...
AS OF 252 PM EDT FRIDAY...A LAKE WIND ADVISORY IS CURRENTLY IN
EFFECT. STRONG SOUTHERLY WINDS 25-30 KNOTS ARE EXPECTED OVER LAKE
CHAMPLAIN AFTER 8PM LASTING THROUGH THE OVERNIGHT HOURS. WIND
WAVES ARE EXPECTED TO REACH 2-4 FEET DURING THIS EVENT.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DEAL
NEAR TERM...NEILES/LOCONTO
SHORT TERM...DEAL
LONG TERM...LAHIFF
AVIATION...RJS
MARINE...MV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1241 AM EDT SAT JUL 18 2015
.SYNOPSIS...
EXPECT AN ACTIVE WEEKEND OF SHOWERS WITH EMBEDDED THUNDERSTORMS
WITH THE POTENTIAL FOR HEAVY RAINFALL. THE HEAVIEST RAIN WILL FALL
AHEAD OF A COLD FRONT THAT MOVES THROUGH THE AREA MONDAY. ANOTHER
FRONT WILL BRING A CHANCE OF SHOWERS AGAIN MID WEEK. AHEAD OF THE
COLD FRONT THIS WEEKEND HOT AND HUMID TEMPERATURES ARE EXPECTED
WITH TEMPERATURES APPROACHING 90 DEGREES IN THE VALLEYS.
TEMPERATURES BEHIND THE FRONT WILL TREND BACK TOWARDS MORE
SEASONABLE HIGHS NEAR 80 AND LOWS NEAR 60.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 1241 AM EDT SATURDAY...THOUGH VIRGA OR VERY LIGHT SHOWERS
PREVAIL ACROSS MUCH OF VERMONT, STEADIER BAND OF RAIN HAS
DEVELOPED EXTENDING ALONG A MSS-SLK-GFL LINE AND WILL MOVE
EASTWARD INTO THE CHAMPLAIN VALLEY BEFORE MIDNIGHT, AND ACROSS THE
REST OF VERMONT AFTER MIDNIGHT. IN THE WAKE OF THIS WARM- FRONTAL
RAIN IS MORE SPOTTY, SCATTERED SHOWERS. UPSTREAM DETROIT RAOB
SHOWS SOME STEEPER MID- LEVEL LAPSE RATES IN A BROADLY CYCLONIC
WEST FLOW. THE LATEST RAP FORECAST PICKS UP ON THESE STEEPER LAPSE
RATES IN ITS DEPICTION OF WEAK NEGATIVE SHOWALTER INDICES
ADVECTING IN THROUGH THE OVERNIGHT. REGARDING POPS AND WEATHER,
I`VE ADDED IN SLIGHT CHANCE THUNDER TO THE GRIDS AFTER MIDNIGHT
ONCE THE MORE FOCUSED WARM FRONTAL RAIN LIFTS EAST.
CURRENT TEMPS GENERALLY IN THE MID 60S TO LOW 70S, WITH SOME
SLIGHT INCREASE IN DEWPOINTS SINCE EARLY EVENING - INTO THE UPPER
50S TO MID 60S. TEMPS WILL BE VERY SLOW TO FALL GIVEN SOUTH
WINDS, WARM ADVECTION REGIME AND OVERCAST SKIES. DEWPOINTS WILL
ALSO GRADUALLY BE ON THE CLIMB WITH MANY AREAS LIKELY TO BE IN THE
60S BY SUNRISE. SO ITS GOING TO BE AN INCREASINGLY MORE HUMID
NIGHT, WITH LOWS IN THE 60S.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH SUNDAY NIGHT/...
AS OF 343 PM EDT FRIDAY...TOMORROW IS STILL EXPECTED TO BE AN
ACTIVE DAY WITH SHOWERS AND THUNDERSTORMS STILL PROGRESSING ACROSS
THE REGION BEHIND THE WARM FRONT. THE WARM ADVECTION SHOWERS
SHOULD COME TO AN END SOME TIME IN THE MORNING WITH A CHANCE FOR
SOME LIGHT CLEARING. THE BEST CHANCE FOR CLEARING WILL BE ACROSS
NORTHERN NEW YORK AND NORTHERN VERMONT. AS THE SOUTHERLY WINDS
CONTINUE TO BRING IN MORE WARMER MOIST AIR EXPECT TOMORROW TO BE
QUITE MUGGY WITH SURFACE DEWPOINTS INCREASING TO THE UPPER 60S TO
NEAR 70 IN THE VALLEYS. THE HIGH DEW POINTS WILL COMBINE WITH
TEMPS AROUND 80 TO GENERATE 1500-2000 J/KG OF CAPE ALONG THE
INTERNATIONAL BORDER. WITH SURFACE CONVERGENCE INCREASING AS A
UPPER LEVEL SHORTWAVE VORT CROSSES THE NORTH COUNTRY EXPECT THERE
TO BE POTENTIAL FOR SOME STRONGER STORMS TO DEVELOP. I CONTINUED
THE MENTION OF HEAVY RAIN AND POTENTIAL FOR GUSTY WINDS IN THE
FORECAST BASED ON MODERATE 0-6KM SHEAR OF 30-40KTS AND THE
ENHANCED SURFACE AND ELEVATED INSTABILITY. EXPECT SCATTERED
SOUTHWESTWARD MOVING STORMS TO SLOWLY MOVE ACROSS THE AREA IN THE
AFTERNOON WITH RELATIVELY LIGHT CORFIDI VECTORS NORTHWEST AT 5-10KNOTS.
GIVEN THE LIGHT DIRECTIONAL WINDS AS THE PWATS INCREASE TO 2.0"
TOMORROW SOME OF THE STORMS COULD PRODUCE HEAVY RAINFALL AND
PRODUCE PONDING IN AREAS OF POOR DRAINAGE AND IN URBAN AREAS.
AS WE LOSE THE DIURNAL HEATING SATURDAY NIGHT EXPECT SHOWERS TO
DISSIPATE OVERNIGHT BEFORE FIRING AGAIN IN EARNEST BY MID MORNING
SUNDAY. SUNDAY WILL SEE CONTINUED HIGH DEWPOINTS WITH PLENTY OF
LOW LEVEL MOISTURE AND AS THE SHORTWAVE CLEARS THE REGION ON
SATURDAY EVENING EXPECT BETTER CLEARING ON SUNDAY MORNING. THE
RESULT OF THAT WILL BE AN EVEN BETTER CHANCE FOR SLOW MOVING
SHOWERS ON SUNDAY WITH DAYTIME TEMPERATURES IN THE UPPER 80S
APPROACHING NEAR 90 DEGREES IN THE SAINT LAWRENCE AND CHAMPLAIN
VALLEY. WITH WEAK SHEAR IN THE 0-6KM PROFILE I ANTICIPATE THE
THREAT FOR STRONG STORMS TO BE MINOR BUT WITH THE SURFACE
INSTABILITY STILL QUITE LARGE RANGING FROM 2000-3000 J/KG CAPE
OVER NORTHERN NEW YORK BY MID DAY ON SUNDAY STRONG TO SEVERE
STORMS CANT BE RULED OUT. DECENT LAPSE RATES IN THE 700-500MB
LAYER SHOW EVIDENCE OF A WELL DEVELOPED EML MOVING INTO THE AREA
SO THE THREAT OF HEAVY RAIN WILL CONTINUE SUNDAY AFTERNOON INTO
SUNDAY EVENING.
PWATS WILL BE 1 TO 2 STANDARD DEVIATIONS ABOVE NORMAL INTO SUNDAY
EVENING SO THE THREAT OF ISOLATE FLASH FLOODING IS POSSIBLE AND
THUS I WENT AHEAD AND UPDATED THE FORECAST TO SHOW THE ENHANCED
WORDING OF HEAVY RAINFALL FOR SUNDAY AFTERNOON AND SUNDAY EVENING
AHEAD OF THE COLD FRONT THAT PASSES THROUGH ON MONDAY.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 320 PM EDT FRIDAY...SURFACE COLD FRONT SHIFTING THROUGH THE
FORECAST AREA MONDAY MORNING WITH PRECIPITATION EXITING FROM WEST
TO EAST THROUGH THE DAY. MAX TEMPS WILL BE TRICKY WITH UNCERTAINTY
IN THE EXACT FROPA TIMING, BUT GIVEN THE WARM OVERNIGHT TEMPERATURES
ANY CLEARING IN THE AFTERNOON SHOULD ALLOW TEMPS TO REBOUND INTO
THE LOWER 80S.
DRIER CONDITIONS RETURN FOR MONDAY NIGHT THROUGH TUESDAY NIGHT AS A
WEAK RIDGE OF HIGH PRESSURE MOVES ACROSS THE AREA. A FEW WEAK
DISTURBANCES IN FLOW ALOFT COMBINED WITH SOME AFTERNOON INSTABILITY
MAY BE ENOUGH TO PRODUCE SOME SHOWERS OVER THE HIGHER TERRAIN
TUESDAY/WEDNESDAY, BUT OTHERWISE DRY WEATHER IS EXPECTED THROUGH THE
END OF THE WORK WEEK. TEMPS WILL RUN RIGHT AROUND NORMAL, MAYBE JUST
A FEW DEGREES ABOVE WITH HIGHS GENERALLY IN THE UPPER 70S TO MID 80S
AND LOWS IN THE MID 50S TO LOW 60S.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 00Z SUNDAY...VFR CONDITIONS WITH MID-HIGH CEILINGS WILL
QUICKLY LOWER WITH ASSOCIATED PRECIP/SHOWERS DEVELOP BETWEEN 00Z
AND 03Z SATURDAY. CIGS LOWERING TO MVFR AREA-WIDE AND LOCALLY IFR
FOR A BRIEF PERIOD AT KSLK/KMPV. PRECIP SHIFTS OUT OF THE REGION
AFTER 09-12Z WITH MVFR CIGS TRENDING TO VFR BY 18Z. HOWEVER...SOME
-SHRA/-TSRA MAY DEVELOP AFT 18Z BUT ARE NOT CURRENTLY IN TAFS DUE
TO UNCERTAINTY IN COVERAGE/TIME. SOUTHERLY WINDS 5-10KTS THRU 12Z
AND UP TO 15-20 KTS IN CHAMPLAON VALLEY AFT 12Z SAT.
OUTLOOK 00Z SUNDAY THROUGH WEDNESDAY...
00Z SAT - 06Z SUN...VFR/MVFR. SCATTERED SHOWERS AND
THUNDERSTORMS, MAINLY ACROSS VT ENDING.
06Z SUN - 18Z SUN...MAINLY VFR. EARLY MORNING IFR FOG POSSIBLE AT
KMPV/KSLK.
18Z SUN - 18Z MON...VFR/MVFR IN PERIODS OF SHOWERS AND
THUNDERSTORMS.
18Z MON - 12Z WED...MAINLY VFR. EARLY MORNING IFR
FOG POSSIBLE AT KMPV/KSLK.
12Z WED - 00Z THU...MAINLY VFR. CHANCE
AFTERNOON -SHRA.
&&
.MARINE...
AS OF 252 PM EDT FRIDAY...A LAKE WIND ADVISORY IS CURRENTLY IN
EFFECT. STRONG SOUTHERLY WINDS 25-30 KNOTS ARE EXPECTED OVER LAKE
CHAMPLAIN AFTER 8PM LASTING THROUGH THE OVERNIGHT HOURS. WIND
WAVES ARE EXPECTED TO REACH 2-4 FEET DURING THIS EVENT.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DEAL
NEAR TERM...NEILES/LOCONTO
SHORT TERM...DEAL
LONG TERM...LAHIFF
AVIATION...LAHIFF/SLW
MARINE...MV
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1015 PM EDT SUN JUL 19 2015
.SYNOPSIS...
HIGH HEAT AND HUMIDITY WILL CONTINUE THROUGH TUESDAY. ON WEDNESDAY
A COLD FRONT WILL ENTER THE AREA AND STALL FOR A FEW DAYS BRINGING
A BETTER COVERAGE OF SHOWERS AND THUNDERSTORMS AND A BREAK FROM
THE HEAT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 10 PM SUNDAY... CLOUD TOPS ARE WARMING ON INFRARED SATELLITE
IMAGERY AND THERE IS NO LONGER ANY CLOUD TO GROUND OR EVEN IN CLOUD
LIGHTNING NOTED IN THE AREA. AND ALTHOUGH THIS TOOK TWO HOURS LONGER
TO BE TRUE WHEN COMPARED TO YESTERDAY THERE IS NO UPSTREAM
CONVECTION ASSOC WITH THE NEXT SHORTWAVE. THUS FEEL THAT LOCAL HI
RES MODELS LIKE THE HRRR ARE CORRECT IN KEEPING US RAIN-FREE FOR THE
REST OF THE PERIOD. THE 00Z OPERATIONAL WRF HAS COME IN GIVING
SUPPORT TO THIS IDEA AS WELL IN CONTRAST WITH ITS EARLIER RUN THAT
HELD ON TO SOME LIGHT RAIN SHOWERS INTO AT LEAST PART OF THE
OVERNIGHT. THE REMAINDER OF THE NIGHT WILL FEATURE RAIN OVER NWRN
COUNTIES TIL ABOUT MIDNIGHT FOLLOWED BY A THINNING VEIL OF DEBRIS
CIRRUS. ANY FOG THAT DEVELOPS IN AREAS THAT SEE RAIN WILL ONLY BE OF
THE VARIETY OF CONCERN TO AVIATION/FIRE WEATHER. DEWPOINTS IN THE
LOW TO MID 70S WILL APPROXIMATE THE MUGGY NIGHTTIME LOW
TEMPERATURES.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...THE REGION WILL SPEND ONE LAST DAY ON THE
PERIPHERY OF A 5H RIDGE CENTERED OVER TX ON MON. TUE A 5H LOW OVER
EASTERN CANADA WILL EXPAND SOUTH...SUPPRESSING THE SOUTHERN CONUS
5H RIDGE. ALTHOUGH DEEP WEST TO NORTHWEST FLOW REMAINS IN PLACE
THROUGH THE PERIOD THE COMBINATION OF DEEP MOISTURE...PRECIPITABLE
WATER IS AROUND 2 INCHES EACH AFTERNOON...AND THE PIEDMONT
TROUGH/SEA BREEZE SHOULD GENERATE SOME ISOLATED AFTERNOON
CONVECTION. GFS AND NAM SHOW A WEAK SHORTWAVE PASSING EACH
DAY...BUT TIMING IS A LITTLE TOO EARLY BOTH MON AND TUE MEANING
LIMITED DIURNAL INSTABILITY. SUBSIDENCE AS THE WAVE IS EXITING
WILL WORK TO OFFSET CONVECTION DUE TO DIURNAL HEATING AND SURFACE
BOUNDARIES. STILL THINK SOME CONVECTION WILL DEVELOP EACH
AFTERNOON BUT COVERAGE WILL BE LIMITED TO SLIGHT CHC TO LOW CHC AT
BEST. ORGANIZED SEVERE IS HIGHLY UNLIKELY GIVEN THE LACK OF ANY
STRONG FEATURES BUT AN ISOLATED STRONG TO SEVERE STORM REMAINS A
POSSIBILITY.
BEST PRECIP CHANCES MAY BE AT THE END OF THE PERIOD...AHEAD OF
WEAKENING COLD FRONT DROPPING IN FROM THE NORTHWEST. ALTHOUGH THE
FRONT WILL BE ARRIVING LATE TUE NIGHT THERE WILL BE PLENTY OF
MOISTURE AHEAD OF THE BOUNDARY AND AT LEAST SOME LINGERING
INSTABILITY. DO NOT THINK WIDESPREAD PRECIP WILL DEVELOP BUT THINK
CHC POP IS WARRANTED TUE NIGHT...ESPECIALLY INLAND.
TEMPERATURES WILL REMAIN ABOVE CLIMO THROUGH TUE NIGHT. HIGHS WILL
BE IN THE MID TO UPPER 90S EACH AFTERNOON AWAY FROM THE PINNED SEA
BREEZE. COMBINATION OF DEEPER MOISTURE AND THE HEAT WILL RESULT IN
HEAT INDEX VALUES IN THE 105 TO 109 RANGE MON WITH POTENTIALLY
HIGHER VALUES IN PLACES ON TUE. BASED ON THE EXPECTED HEAT INDEX
VALUES MON HAVE ISSUED A HEAT ADVISORY FOR ALL ZONES...EVEN THE
COASTAL ZONES GIVEN THE EXPECTED LIMITED INLAND PENETRATION OF THE
SEA BREEZE.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 3 PM SUNDAY...AN EAST TO WEST FLATTER MID TO UPPER RIDGE
OVER THE SOUTH WILL BECOME MORE AMPLIFIED UP THE THROUGH THE
MIDWEST THROUGH MID TO LATE WEEK ALLOWING TROUGH TO DIG DOWN ALONG
THE EAST COAST. THEREFORE...A GENERAL WESTERLY FLOW ALOFT WED INTO
THURS WILL BEGIN TO VEER ON FRI BECOMING MORE N-NW BY FRI NIGHT
INTO SATURDAY. THE LATEST MODEL RUNS SHOW A WEAK FRONT PUSHING
SOUTHEAST THROUGH WED LEAVING AN AREA OF LOW PRESSURE AND TROUGH
LINGERING OVER OR JUST SOUTH OF AREA THURS INTO FRIDAY. BY
SATURDAY THE MID TO UPPER RIDGE BUILDS FAR ENOUGH TO THE NORTH
NORTHEAST INTO THE GREAT LAKES KEEPING MORE OF A DRIER NORTHERLY
FLOW ALOFT AND BETTER SUBSIDENCE AND DRY AIR THROUGH THE MID TO
UPPER LEVELS TO KEEP MOST CONVECTION AT BAY. THEREFORE WILL SHOW
GREATEST POPS COASTAL ON WED AS SEA BREEZE COMES AGAINST NW FLOW
BEHIND FRONT TO PRODUCE GREATEST CONVERGENCE CLOSER TO THE
COAST...THEN SHIFTING SOUTH INTO SC ON THURS INTO FRI AS BOUNDARY
LINGERS NEARBY. THEN DRIER AND RELATIVELY COOLER TEMPS BY NEXT
WEEKEND AS MID TO UPPER TROUGH DIGS DOWN AND TROUGH AXIS SHIFTS
OFF SHORE ALLOWING A DEEP N-NW FLOW TO SET UP. IF RIDGE DOES NOT
BUILD NORTHEAST INTO THE GREAT LAKES FAR ENOUGH AND WINDS STAY
MORE NW INSTEAD OF NORTHERLY ALOFT...THERE WILL BE A GREATER CHC
OF UPSTREAM CONVECTION/MCS OR SHORTWAVE ENERGY MAKING ITS WAY INTO
THE AREA LATE SAT INTO SUNDAY.
AS FOR TEMPS...WED WILL BEGIN THE END OF DANGEROUS HEAT AS LOW LEVEL
WINDS VEER AROUND WITH 850 TEMPS DOWN TO 18C BY WED AFTN AND
REMAINING AROUND THAT VALUE THROUGH THE WEEKEND. THE GRADIENT OF
DRIER VS MOISTER AIR WILL RUN MORE N-NW TO S-SE WITH PCP WATER
VALUES DROPPING DOWN CLOSER TO AN INCH OVER CENTRAL TO NORTHERN NC
AND REMAINING UP TO 2 INCHES OVER CENTRAL TO COASTAL SC ON WED SOUTH
OF FRONTAL BOUNDARY/TROUGH. THE SFC DEWPOINTS MAY NOT SEE AS GREAT A
CHANGE DEPENDING ON HOW FAR SOUTH THE SFC BOUNDARY ACTUALLY MAKES
IT. GFS SHOWS LOWER SFC DEWPOINTS BY WED INTO THURS MOVING INTO AREA
FROM THE NORTH BUT ECMWF SHOWS A GREATER CHANGE FOR NEXT WEEKEND.
OVERALL EXPECT TEMPS BACK DOWN CLOSER TO NORMAL VALUES OR POSSIBLY
BELOW WITH CLOUDS AND CONVECTION AFFECTING TEMPS AND POSSIBLE DRIER
AIR MOVING SOUTH INTO AREA.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 00Z...THUNDERSTORMS WEST OF KCRE/KMYR WILL PRODUCE ONLY
VCSH AT BEST EARLY THIS EVENING. VCTS EXPECTED AT KFLO/KLBT
THROUGH 02Z WITH A GOOD CHANCE OF TEMPO TSRA/IFR. CONVECTION
SHOULD DIE OFF BY 05Z. WINDS BECOME VARIABLE AFTER 02Z...EXCEPT AT
THE COASTAL TERMINALS WHERE WINDS WILL BECOME SW AROUND 4 KT BY
MIDNIGHT Z.
OVERNIGHT BR WILL DEVELOP WITH TEMPO IFR AT KFLO/KLBT DUE TO MOIST
SOILS FROM TODAYS ACTIVITY. TEMPO MVFR CAN BE EXPECTED AT THE
COASTAL TERMINALS. AFTER SUNRISE VFR EXPECTED WITH LIGHT WEST WINDS.
THE SEA BREEZE MOVES THROUGH THE COASTAL TERMINALS BY LATE MORNING
SHIFTING WINDS TO THE SSW...BUT WESTERLY WINDS ALOFT COULD DELAY
PASSAGE TO MID AFTERNOON.
EXTENDED OUTLOOK...BRIEF MVFR POSSIBLE THROUGH THE PERIOD FROM
DIURNAL CONVECTION. OTHERWISE VFR.
&&
.MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 10PM
SUNDAY...OUTFLOW FROM DYING CONVECTION INLAND MAY BRIEFLY DISRUPT
THE OTHERWISE SYNOPTIC SOUTHWESTERLY FLOW. NEXT FEW HOURS THIS MAY
EVEN MEAN A QUICK TURN TO THE W OR NW BUT FOR THE MOST PART THERE
MAY JUST BE A RELAXATION IN THE GRADIENT. ONCE THIS BOUNDARY WASHES
OUT (MIDNIGHT-1AM) IT WILL BE BACK TO THE INLAND TROUGH-BORNE
SOUTHWESTERLY FLOW.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...SOUTHWEST FLOW WILL CONTINUE OVER THE WATERS
THROUGH THE PERIOD WITH BERMUDA HIGH AND PIEDMONT TROUGH THE
DOMINANT FEATURES. LATE IN THE PERIOD A WEAK COLD FRONT WILL DROP
IN FROM THE NORTHWEST BUT WILL NOT REACH THE WATERS BEFORE THE END
OF THE PERIOD. SOUTHWEST FLOW ON MON WILL BE IN THE 10 TO 15 KT
RANGE...PEAKING AT A SOLID 15 KT IN THE EVENING. WINDS WILL BE
SLIGHTLY HIGHER TUE WITH SPEEDS AROUND 15 KT INCREASING TO 15 TO
20 KT IN THE EVENING. SEAS 2 TO 4 FT ON MON WILL RUN 3 TO 4 FT TUE
WITH POTENTIAL FOR SOME ISOLATED 5 FT NEAR 20 NM IN THE EVENING.
ALTHOUGH CANNOT RULE OUT A MARGINAL SCEC TUE EVENING/NIGHT
HEADLINES SEEM LIKE A LONG SHOT.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 3 PM SUNDAY...A WEAK FRONT WILL DROP SOUTH REACHING INTO
AREA WATERS ON WED. THE LATEST MODELS KEEP THIS BOUNDARY BISECTING
WATERS WITH SLIGHTLY STRONGER WINDS OUT OF THE SW-W SOUTH OF
BOUNDARY AND LIGHTER NORTHERLY FLOW BEHIND IT...MAINLY NORTH OF
CAPE FEAR. AS SEA BREEZE DEVELOPS...WINDS WILL BECOME MORE ON
SHORE THROUGH WED AND WILL REMAIN LIGHTER AND MORE VARIABLE WITH A
GENERAL EASTERLY FLOW THROUGH THURS INTO FRI. THE WEAKENING FLOW
WILL ALLOW LAND/SEA BREEZE TO DOMINATE THE WINDS WITH GREATER ON
SHORE FLOW EACH AFTN AND A LIGHT OFF SHORE FLOW OVERNIGHT HEADING
INTO THE WEEKEND. THIS LINGERING BOUNDARY WILL MEANDER ACROSS THE
WATERS WHILE IT WEAKENS FURTHER THROUGH THE PERIOD. OVERALL EXPECT
SEAS 2 TO 4 FT WITH A SLIGHT DOWNWARD TREND THROUGH WED AND SLIGHT
UPWARD TREND THURS INTO FRI IN AN ON SHORE EASTERLY FLOW.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...HEAT ADVISORY FROM 1 PM TO 7 PM EDT MONDAY FOR SCZ017-023-024-
032-033-039-053>056.
NC...HEAT ADVISORY FROM 1 PM TO 7 PM EDT MONDAY FOR NCZ087-096-099-
105>110.
MARINE...NONE.
&&
$$
NEAR TERM...MBB
SHORT TERM...III
LONG TERM...RGZ
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
310 PM EDT SAT JUL 18 2015
.SYNOPSIS...A SURFACE TROUGH WILL DEVELOP OVER THE AREA TODAY AND
REMAIN ACROSS THE REGION INTO NEXT WEEK. AN UPPER LEVEL DISTURBANCE
WILL TRACK SOUTHEASTWARD FROM FROM THE OHIO VALLEY THIS MORNING AND
ACROSS CENTRAL NC THIS AFTERNOON AND EVENING.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 1015 AM SATURDAY...
EARLIER COMPLEX OF SHOWERS MOVING INTO THE TRIAD HAS ALL BUT
DIMINISHED THIS HOUR WITH A BAD OF CLOUDS REMAINING FROM THE
FOOTHILLS...JUST NOW MOVING INTO THE NW PIEDMONT. NOT A LOT OF
ENHANCEMENT ON THE VISIBLE PICTURE AT THIS TIME AND THE HRRR HAS
BACKED OFF ON ALL PRECIPITATION UNTIL AROUND 17Z WHEN TEMPERATURES
RISE ENOUGH TO START GETTING CONVECTIVE INITIATION ACROSS THE AREA.
CONVECTION SHOULD BEGIN AS SCATTERED SHOWERS ACROSS MUCH OF THE CWA
BUT THEN A PUSH FROM A SHORTWAVE ENTERING THE TRIAD AFTER 18Z COULD
BEGIN TO ORGANIZE STORMS A LITTLE MORE. WITH BULK SHEAR VALUES IN
THE 20-25 KT RANGE AND INSTABILITY BETWEEN 1000-1500 J/KG WOULD
EXPECT SOME KIND OF LINEAR MULTICELLULAR FEATURE WHICH WILL WORK
THROUGH THE CWA FROM NW TO SE THIS AFTERNOON AND INTO THE EARLY
EVENING HOURS. EXPECT THE BEST UPPER LEVEL SUPPORT FROM 500 MB
VORTICITY TO MOVE THROUGH THE TRIANGLE AREA MID AFTERNOON AND THE I-
95 CORRIDOR BY EARLY EVENING. SPC CURRENTLY HAS THE AREA UNDER A
MARGINAL RISK FOR ANY SEVERE STORMS WITH DAMAGING WINDS THE PRIMARY
THREAT. ANY SEVERE ACTIVITY THIS AFTERNOON SHOULD REMAIN ISOLATED.
PREVIOUS DISCUSSION FOLLOWS. -ELLIS
HIGH TEMPS TODAY ARE EXPECTED TO BE LARGELY DEPENDENT ON THE AMOUNT
OF DEBRIS CLOUD COVER FROM THE APPROACHING CONVECTIVE COMPLEX. HAVE
LOWERED PREVIOUS HIGH TEMPS BY A DEGREE OR TWO... GIVEN INCREASING
CLOUD COVER LATER TODAY... ALONG WITH THE DEVELOPMENT OF EXPECTED
STORMS THIS AFTERNOON. THUS... WILL GO WITH HIGH TEMPS IN THE LOWER
TO MID 90S.
TONIGHT AND SUNDAY: ANY LINGERING CONVECTION IS EXPECTED TO PUSH TO
THE SOUTH AND EAST OF THE AREA AND/OR DISSIPATE BY EARLY SUNDAY
MORNING... WITH MID LEVEL FEATURE SHIFTING TO THE SOUTH AND EAST OF
THE AREA. OVERNIGHT LOWS SHOULD BE WARM AGAIN FOR TONIGHT... WITH
LOWS GENERALLY EXPECTED IN THE LOWER TO MID 70S.
THE CENTER OF THE MID LEVEL RIDGE IS EXPECTED TO REMAIN OVER THE
SOUTH CENTRAL U.S. ON SUNDAY... WITH CENTRAL NC ON THE PERIPHERY OF
THE EXTENDING EASTWARD RIDGE AXIS. THIS SHOULD ALLOW FOR A
CONTINUATION OF WEST TO NORTHWEST FLOW ALOFT. HOWEVER... THE LATEST
GUIDANCE DOES NOT SHOW MUCH IN THE WAY OF ANY DISTURBANCES ALOFT
TRACKING ACROSS THE AREA ON SUNDAY. THUS... EXPECT ANY CONVECTIVE
ACTIVITY WILL BE MORE ISOLATED TO WIDELY SCATTERED. THIS COUPLED
WITH SLIGHTLY HIGHER AFTERNOON LOW LEVEL THICKNESS VALUES THAN
TODAYS SHOULD YIELD HIGH TEMPS IN THE MID TO UPPER 90S... WITH
POSSIBLY A FEW LOCATIONS TOUCHING 100 ACROSS THE SOUTH/SOUTHWESTERN
PORTION OF THE FA. -BSD
&&
.SHORT TERM /SUNDAY NIGHT/...
AS OF 300 AM SATURDAY...
TO BE UPDATED SHORTLY.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 310 PM SATURDAY...
MON: HOT WITH LOWER-THAN-USUAL (FOR SUMMERTIME) STORM CHANCES. WE
REMAIN BENEATH NORTHWESTERLY STEERING FLOW... ON THE NE SIDE OF THE
SPRAWLING RIDGE FROM NW MEXICO ACROSS TX AND THE LOWER MISS
VALLEY... BUT THIS FLOW IS VERY LIGHT OVER NC WITH THE STRONGER MID
LEVEL WINDS AND DIFFLUENCE WELL TO OUR NW. A PROMINENT PERTURBATION
CROSSING KS/NRN/MO/IL/OH VALLEY INTO MON EVENING MAY HELP BUILD
SHORTWAVE RIDGING DOWNSTREAM OVER NC MUCH OF THE DAY... AND
ACCORDINGLY THE MODELS ARE FORECASTING LITTLE POTENTIAL BUOYANCY
WITH NC MUCAPE VALUES GENERALLY BELOW 1000 J/KG EVEN AT PEAK
HEATING... ALONG WITH SUB-20 KT DEEP LAYER SHEAR... AND A WARM 500-
300 MB LAYER. A WEAK SURFACE TROUGH WILL HOLD OVER THE COASTAL
PLAIN... AND THIS AREA WITH ITS HIGHER SURFACE DEWPOINTS MAY SEE A
BIT BETTER CHANCE FOR AFTERNOON CONVECTION... BUT STILL MEAGER GIVEN
THE LACK OF STRONG DYNAMIC OR THERMODYNAMIC SUPPORT. ANYTHING THAT
CAN GET GOING MAY GENERATE ENHANCED DOWNDRAFTS GIVEN THE INVERTED-V
FORECAST SOUNDING APPEARANCE AND DCAPE NEARING 1000 J/KG. WILL KEEP
POPS LOW AT 15-30% AT MOST... HIGHEST EAST OF I-95. OUR LOW LEVEL
THICKNESSES SHOULD BE WELL ABOVE NORMAL (BY 15-20 M)... WITH THE MID
LEVEL ANTICYCLONE CENTERED IN THE CLIMATOLOGICALLY IDEAL LOCATION
FOR ATYPICALLY HOT TEMPS IN NC. FOLLOWING THIS AND WITH THE WARMING
TREND OF GUIDANCE... EXPECT HIGHS OF 95-100... A FEW DEGREES SHY OF
THE DAILY RECORD HIGHS. HEAT INDICES COULD REACH 103-104 DEGREES
MAINLY IN THE SOUTHEAST... ALTHOUGH IF DEWPOINTS DON`T SLIP INTO THE
UPPER 60S WITH MIXING... READINGS COULD HIT 105 BRIEFLY. WE MAY SEE
ISOLATED DYING SHOWERS SPILLING OVER FROM THE HIGHER TERRAIN MON
NIGHT. WARM LOWS OF 71-76.
TUE: CONTINUE HOT WITH BETTER STORM CHANCES THAN MON. STILL
ANTICIPATE ABOVE NORMAL TEMPS BUT WILL PROBABLY BE MUTED FROM
MONDAY`S READINGS BY UPSTREAM CONVECTIVE DEBRIS CLOUDS MOVING
OVERHEAD... TRIMMING HEATING A BIT... SO EXPECT TUE HIGHS TO BE A
DEGREE OR TWO LOWER THAN MONDAY`S... DESPITE THICKNESSES COMPARABLE
TO THOSE EXPECTED MONDAY. HEAT INDICES SHOULD ONCE AGAIN APPROACH
103-104 DEGREES IN THE SOUTHEAST. PROJECTED MUCAPE TUE IS STILL
UNIMPRESSIVE... JUST 750-1500 J/KG... WITH MEAGER DEEP LAYER SHEAR
OF AROUND 20 KTS. BUT DYNAMIC FORCING WILL BE ON THE UPSWING AS THE
MID LEVEL LOW OVER QUEBEC DIGS ACROSS THE GREAT LAKES AND
NORTHEAST... PROVIDING SLIGHT DPVA AND HEIGHT FALLS ESPECIALLY LATE
TUE THROUGH TUE NIGHT... IN CONJUNCTION WITH THE SURFACE COLD FRONT
PUSHING IN FROM THE NW. WILL TOP OUT POPS AT 30-40%... ALTHOUGH THIS
MAY RISE IN LATER FORECASTS IF TIMING CAN BE PINNED DOWN.
WED-SAT: MOST OF THE AREA (EXCEPT FOR SE SECTIONS) WILL BE IN A
RELATIVE LULL CONVECTION-WISE AS THE SURFACE FRONT IS EXPECTED TO
SETTLE OVER SRN/ERN NC WITH HIGH PRESSURE STARTING TO BUILD IN FROM
THE NW. WILL KEEP GOOD CHANCE POPS ACROSS THE SOUTH AND EAST WED
WHERE PW VALUES WILL BE NEAR TO ABOVE NORMAL... HOWEVER DRIER AIR
ELSEWHERE SHOULD LIMIT STORM COVERAGE OVER THE NORTH AND WEST WED.
CONVECTION CHANCES LOOK TO RISE THU AND PEAK FRI... AS STRONG
SHORTWAVE ENERGY MOVES ESE INTO THE MIDATLANTIC REGION... INTO THE
MEAN TROUGH BASE... WITH A NORTHWARD SURGE OF THE SURFACE FRONTAL
ZONE. THE INITIALLY LOWER PW VALUES CLIMB BACK UP CLOSE TO 2.0
INCHES ESPECIALLY IN THE SOUTH HALF FRI... AND THIS IS WHERE THE
GREATEST COVERAGE SHOULD BE. THE MID LEVEL TROUGH AXIS AND SURFACE
FRONT SHOULD THEN SETTLE SOUTHEAST OF THE NC... USHERING IN A
SLIGHTLY DRIER AIR MASS TO START THE WEEKEND. THICKNESSES SUGGEST
CONTINUED ABOVE NORMAL TEMPS WED... A COUPLE OF DEGREES COOLER BUT
STILL SLIGHTLY ABOVE NORMAL THU... THEN NEAR NORMAL FRI/SAT. -GIH
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 200 PM SATURDAY...
24 HOUR TAF PERIOD: A LINE OF CONVECTION IS MOVING OVER KRDU AT THIS
TIME AND WILL BE APPROACHING KRWI IN THE NEXT FEW HOURS IF IT HOLDS
TOGETHER. TO THE SOUTH...MORE SCATTERED THUNDERSTORMS WILL APPROACH
THE VICINITY OF KFAY BY 20Z OR SO. WIND GUSTS OF 40-50 KTS ARE
POSSIBLE WITH THESE STORMS BUT THE MAJORITY OF CONVECTION WILL SEE
WIND GUSTS REMAIN UNDER 30 KTS. BEHIND THE LINE...WINDS ARE EXPECTED
TO BRIEFLY GO NORTHWESTERLY BEFORE RETURNING TO A GENERAL
SOUTHEASTERLY FLOW. OVERNIGHT...SOME VFR VISIBILITIES ARE POSSIBLE
AROUND DAYBREAK. WITH NO DISCERNIBLE SHORT WAVE IN THE
AREA...CONVECTIVE COVERAGE SUNDAY AFTERNOON SHOULD BE LESS THAN THIS
AFTERNOON.
LONG TERM: WITH A RETURN TO SOUTHERLY FLOW...EXPECT AN UPTICK IN
DIURNAL COVERAGE OF SHOWERS AND THUNDERSTORMS BEGINNING SATURDAY
AFTERNOON/EVENING AND CONTINUING THROUGH THE END OF THE LONG TERM
WHICH COULD PRESENT SOME ADVERSE CONDITIONS EACH DAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RAH
NEAR TERM...ELLIS/BSD
SHORT TERM...WSS
LONG TERM...HARTFIELD
AVIATION...ELLIS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
217 PM EDT SAT JUL 18 2015
.SYNOPSIS...A SURFACE TROUGH WILL DEVELOP OVER THE AREA TODAY AND
REMAIN ACROSS THE REGION INTO NEXT WEEK. AN UPPER LEVEL DISTURBANCE
WILL TRACK SOUTHEASTWARD FROM FROM THE OHIO VALLEY THIS MORNING AND
ACROSS CENTRAL NC THIS AFTERNOON AND EVENING.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 1015 AM SATURDAY...
EARLIER COMPLEX OF SHOWERS MOVING INTO THE TRIAD HAS ALL BUT
DIMINISHED THIS HOUR WITH A BAD OF CLOUDS REMAINING FROM THE
FOOTHILLS...JUST NOW MOVING INTO THE NW PIEDMONT. NOT A LOT OF
ENHANCEMENT ON THE VISIBLE PICTURE AT THIS TIME AND THE HRRR HAS
BACKED OFF ON ALL PRECIPITATION UNTIL AROUND 17Z WHEN TEMPERATURES
RISE ENOUGH TO START GETTING CONVECTIVE INITIATION ACROSS THE AREA.
CONVECTION SHOULD BEGIN AS SCATTERED SHOWERS ACROSS MUCH OF THE CWA
BUT THEN A PUSH FROM A SHORTWAVE ENTERING THE TRIAD AFTER 18Z COULD
BEGIN TO ORGANIZE STORMS A LITTLE MORE. WITH BULK SHEAR VALUES IN
THE 20-25 KT RANGE AND INSTABILITY BETWEEN 1000-1500 J/KG WOULD
EXPECT SOME KIND OF LINEAR MULTICELLULAR FEATURE WHICH WILL WORK
THROUGH THE CWA FROM NW TO SE THIS AFTERNOON AND INTO THE EARLY
EVENING HOURS. EXPECT THE BEST UPPER LEVEL SUPPORT FROM 500 MB
VORTICITY TO MOVE THROUGH THE TRIANGLE AREA MID AFTERNOON AND THE I-
95 CORRIDOR BY EARLY EVENING. SPC CURRENTLY HAS THE AREA UNDER A
MARGINAL RISK FOR ANY SEVERE STORMS WITH DAMAGING WINDS THE PRIMARY
THREAT. ANY SEVERE ACTIVITY THIS AFTERNOON SHOULD REMAIN ISOLATED.
PREVIOUS DISCUSSION FOLLOWS. -ELLIS
HIGH TEMPS TODAY ARE EXPECTED TO BE LARGELY DEPENDENT ON THE AMOUNT
OF DEBRIS CLOUD COVER FROM THE APPROACHING CONVECTIVE COMPLEX. HAVE
LOWERED PREVIOUS HIGH TEMPS BY A DEGREE OR TWO... GIVEN INCREASING
CLOUD COVER LATER TODAY... ALONG WITH THE DEVELOPMENT OF EXPECTED
STORMS THIS AFTERNOON. THUS... WILL GO WITH HIGH TEMPS IN THE LOWER
TO MID 90S.
TONIGHT AND SUNDAY: ANY LINGERING CONVECTION IS EXPECTED TO PUSH TO
THE SOUTH AND EAST OF THE AREA AND/OR DISSIPATE BY EARLY SUNDAY
MORNING... WITH MID LEVEL FEATURE SHIFTING TO THE SOUTH AND EAST OF
THE AREA. OVERNIGHT LOWS SHOULD BE WARM AGAIN FOR TONIGHT... WITH
LOWS GENERALLY EXPECTED IN THE LOWER TO MID 70S.
THE CENTER OF THE MID LEVEL RIDGE IS EXPECTED TO REMAIN OVER THE
SOUTH CENTRAL U.S. ON SUNDAY... WITH CENTRAL NC ON THE PERIPHERY OF
THE EXTENDING EASTWARD RIDGE AXIS. THIS SHOULD ALLOW FOR A
CONTINUATION OF WEST TO NORTHWEST FLOW ALOFT. HOWEVER... THE LATEST
GUIDANCE DOES NOT SHOW MUCH IN THE WAY OF ANY DISTURBANCES ALOFT
TRACKING ACROSS THE AREA ON SUNDAY. THUS... EXPECT ANY CONVECTIVE
ACTIVITY WILL BE MORE ISOLATED TO WIDELY SCATTERED. THIS COUPLED
WITH SLIGHTLY HIGHER AFTERNOON LOW LEVEL THICKNESS VALUES THAN
TODAYS SHOULD YIELD HIGH TEMPS IN THE MID TO UPPER 90S... WITH
POSSIBLY A FEW LOCATIONS TOUCHING 100 ACROSS THE SOUTH/SOUTHWESTERN
PORTION OF THE FA. -BSD
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...
AN EXPANSIVE UPPER LEVEL RIDGE OVER THE SOUTHERN U.S. AND A LEE SIDE
TROUGH OVER THE PIEDMONT WILL PRODUCE HOT AND MOSTLY DRY WEATHER
FACTORS FOR CENTRAL NC ON MONDAY. LOW LEVEL THICKNESSES VARY BETWEEN
1440S TO AROUND 1450M IN THE AFTERNOON...INDICATIVE OF TEMPERATURES
WELL INTO THE 90S AND POSSIBLY REACHING THE CENTURY MARK. WITH SFC
DEWPOINTS IN THE UPPER 60S TO NEAR 70...HEAT INDICES 102-106 WILL BE
COMMON WITH A HEAT ADVISORY POSSIBLY WARRANTED...MAINLY IN THE
SANDHILLS AND SECTIONS OF THE COASTAL PLAIN.
THE SUB-TROPICAL AIR MASS WILL PRODUCE SLIGHT-MODERATE INSTABILITY
BY AFTERNOON WHICH SHOULD INITIATE/SUPPORT A FEW THUNDERSTORMS
THOUGH COVERAGE AT THIS TIME APPEARS TO BE NO WORSE THAN 20-25
PERCENT AT ITS PEAK. WILL STILL NEED TO MONITOR UPSTREAM CONDITIONS
AS ANY CONVECTIVELY INDUCE VORT MAX IN THE NW FLOW WOULD LEAD TO
ENHANCE CONVECTIVE DEVELOPMENT OVER OUR REGION. EXPECT RATHER STEEP
LOW LEVEL LAPSE RATES MONDAY AFTERNOON WHICH SUGGEST A DECENT CHANCE
FOR STRONG GUSTY WINDS IN THE VICINITY OF ANY STORMS THAT OCCUR.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...
BY TUESDAY...UPPER RIDGE AMPLIFIES OVER THE CENTRAL U.S...EXTENDING
INTO THE NORTHERN PLAINS. THIS AMPLIFICATION WILL DEEPEN A L/W
TROUGH OVER ONTARIO/QUEBEC...INDUCING NWLY FLOW FROM THE GREAT LAKES
INTO THE CAROLINAS. THIS WILL SEND DISTURBANCES INTO OUR REGION AND
AN ENHANCED THREAT FOR SCATTERED CONVECTION BY TUESDAY. TIMING OF
THESE FEATURES DIFFICULT AND MODEL GUIDANCE IS USUALLY A LITTLE
TARDY. FOR NOW WILL MAINTAIN A CHANCE POP ACROSS THE
REGION...FAVORING TUESDAY AFTERNOON-EVENING. TEMPS TUESDAY DEPENDENT
ON TIMING OF SCATTERED CONVECTION AND EXTENT OF DEBRIS CLOUDINESS
UPSTREAM. FOR NOW WILL ADVERTISE MAX TEMPS ABOUT A CATEGORY LOWER
THAN MONDAY`S MAX TEMPS OVER THE NW THIRD WITH COMPARABLE TEMPS
ELSEWHERE.
WEDNESDAY THROUGH FRIDAY... UPPER RIDGE FLATTENS IN RESPONSE TO A
S/W CROSSING THE NORTHERN PLAINS. TUESDAY`S UPPER LEVEL SHEAR AXIS
PROJECTED TO LIE TO OUR SE ON WEDNESDAY WITH MAINLY WEAK ZONAL FLOW
OVERHEAD. THIS SET-UP CHANGES LITTLE ON THURSDAY. THIS SUGGEST HOT
CONDITIONS WITH MAINLY ISOLATED DIURNALLY DRIVEN CONVECTION BOTH
DAYS. MODEL GUIDANCE SUGGEST AN ENHANCED THREAT FOR CONVECTIVE
COVERAGE BY FRIDAY AS ANOTHER MID-UPPER LEVEL S/W APPROACHES FROM
THE NW. WILL GO WITH A CHANCE POP MOST LOCALES FRIDAY AND TEMPS
REMAINING A CATEGORY OR TWO ABOVE NORMAL.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 200 PM SATURDAY...
24 HOUR TAF PERIOD: A LINE OF CONVECTION IS MOVING OVER KRDU AT THIS
TIME AND WILL BE APPROACHING KRWI IN THE NEXT FEW HOURS IF IT HOLDS
TOGETHER. TO THE SOUTH...MORE SCATTERED THUNDERSTORMS WILL APPROACH
THE VICINITY OF KFAY BY 20Z OR SO. WIND GUSTS OF 40-50 KTS ARE
POSSIBLE WITH THESE STORMS BUT THE MAJORITY OF CONVECTION WILL SEE
WIND GUSTS REMAIN UNDER 30 KTS. BEHIND THE LINE...WINDS ARE EXPECTED
TO BRIEFLY GO NORTHWESTERLY BEFORE RETURNING TO A GENERAL
SOUTHEASTERLY FLOW. OVERNIGHT...SOME VFR VISIBILITIES ARE POSSIBLE
AROUND DAYBREAK. WITH NO DISCERNIBLE SHORT WAVE IN THE
AREA...CONVECTIVE COVERAGE SUNDAY AFTERNOON SHOULD BE LESS THAN THIS
AFTERNOON.
LONG TERM: WITH A RETURN TO SOUTHERLY FLOW...EXPECT AN UPTICK IN
DIURNAL COVERAGE OF SHOWERS AND THUNDERSTORMS BEGINNING SATURDAY
AFTERNOON/EVENING AND CONTINUING THROUGH THE END OF THE LONG TERM
WHICH COULD PRESENT SOME ADVERSE CONDITIONS EACH DAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RAH
NEAR TERM...ELLIS/BSD
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...ELLIS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1023 AM EDT SAT JUL 18 2015
.SYNOPSIS...A SURFACE TROUGH WILL DEVELOP OVER THE AREA TODAY AND
REMAIN ACROSS THE REGION INTO NEXT WEEK. AN UPPER LEVEL DISTURBANCE
WILL TRACK SOUTHEASTWARD FROM FROM THE OHIO VALLEY THIS MORNING AND
ACROSS CENTRAL NC THIS AFTERNOON AND EVENING.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 1015 AM SATURDAY...
EARLIER COMPLEX OF SHOWERS MOVING INTO THE TRIAD HAS ALL BUT
DIMINISHED THIS HOUR WITH A BAD OF CLOUDS REMAINING FROM THE
FOOTHILLS...JUST NOW MOVING INTO THE NW PIEDMONT. NOT A LOT OF
ENHANCEMENT ON THE VISIBLE PICTURE AT THIS TIME AND THE HRRR HAS
BACKED OFF ON ALL PRECIPITATION UNTIL AROUND 17Z WHEN TEMPERATURES
RISE ENOUGH TO START GETTING CONVECTIVE INITIATION ACROSS THE AREA.
CONVECTION SHOULD BEGIN AS SCATTERED SHOWERS ACROSS MUCH OF THE CWA
BUT THEN A PUSH FROM A SHORTWAVE ENTERING THE TRIAD AFTER 18Z COULD
BEGIN TO ORGANIZE STORMS A LITTLE MORE. WITH BULK SHEAR VALUES IN
THE 20-25 KT RANGE AND INSTABILITY BETWEEN 1000-1500 J/KG WOULD
EXPECT SOME KIND OF LINEAR MULTICELLULAR FEATURE WHICH WILL WORK
THROUGH THE CWA FROM NW TO SE THIS AFTERNOON AND INTO THE EARLY
EVENING HOURS. EXPECT THE BEST UPPER LEVEL SUPPORT FROM 500 MB
VORTICITY TO MOVE THROUGH THE TRIANGLE AREA MID AFTERNOON AND THE I-
95 CORRIDOR BY EARLY EVENING. SPC CURRENTLY HAS THE AREA UNDER A
MARGINAL RISK FOR ANY SEVERE STORMS WITH DAMAGING WINDS THE PRIMARY
THREAT. ANY SEVERE ACTIVITY THIS AFTERNOON SHOULD REMAIN ISOLATED.
PREVIOUS DISCUSSION FOLLOWS. -ELLIS
HIGH TEMPS TODAY ARE EXPECTED TO BE LARGELY DEPENDENT ON THE AMOUNT
OF DEBRIS CLOUD COVER FROM THE APPROACHING CONVECTIVE COMPLEX. HAVE
LOWERED PREVIOUS HIGH TEMPS BY A DEGREE OR TWO... GIVEN INCREASING
CLOUD COVER LATER TODAY... ALONG WITH THE DEVELOPMENT OF EXPECTED
STORMS THIS AFTERNOON. THUS... WILL GO WITH HIGH TEMPS IN THE LOWER
TO MID 90S.
TONIGHT AND SUNDAY: ANY LINGERING CONVECTION IS EXPECTED TO PUSH TO
THE SOUTH AND EAST OF THE AREA AND/OR DISSIPATE BY EARLY SUNDAY
MORNING... WITH MID LEVEL FEATURE SHIFTING TO THE SOUTH AND EAST OF
THE AREA. OVERNIGHT LOWS SHOULD BE WARM AGAIN FOR TONIGHT... WITH
LOWS GENERALLY EXPECTED IN THE LOWER TO MID 70S.
THE CENTER OF THE MID LEVEL RIDGE IS EXPECTED TO REMAIN OVER THE
SOUTH CENTRAL U.S. ON SUNDAY... WITH CENTRAL NC ON THE PERIPHERY OF
THE EXTENDING EASTWARD RIDGE AXIS. THIS SHOULD ALLOW FOR A
CONTINUATION OF WEST TO NORTHWEST FLOW ALOFT. HOWEVER... THE LATEST
GUIDANCE DOES NOT SHOW MUCH IN THE WAY OF ANY DISTURBANCES ALOFT
TRACKING ACROSS THE AREA ON SUNDAY. THUS... EXPECT ANY CONVECTIVE
ACTIVITY WILL BE MORE ISOLATED TO WIDELY SCATTERED. THIS COUPLED
WITH SLIGHTLY HIGHER AFTERNOON LOW LEVEL THICKNESS VALUES THAN
TODAYS SHOULD YIELD HIGH TEMPS IN THE MID TO UPPER 90S... WITH
POSSIBLY A FEW LOCATIONS TOUCHING 100 ACROSS THE SOUTH/SOUTHWESTERN
PORTION OF THE FA. -BSD
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...
AN EXPANSIVE UPPER LEVEL RIDGE OVER THE SOUTHERN U.S. AND A LEE SIDE
TROUGH OVER THE PIEDMONT WILL PRODUCE HOT AND MOSTLY DRY WEATHER
FACTORS FOR CENTRAL NC ON MONDAY. LOW LEVEL THICKNESSES VARY BETWEEN
1440S TO AROUND 1450M IN THE AFTERNOON...INDICATIVE OF TEMPERATURES
WELL INTO THE 90S AND POSSIBLY REACHING THE CENTURY MARK. WITH SFC
DEWPOINTS IN THE UPPER 60S TO NEAR 70...HEAT INDICES 102-106 WILL BE
COMMON WITH A HEAT ADVISORY POSSIBLY WARRANTED...MAINLY IN THE
SANDHILLS AND SECTIONS OF THE COASTAL PLAIN.
THE SUB-TROPICAL AIR MASS WILL PRODUCE SLIGHT-MODERATE INSTABILITY
BY AFTERNOON WHICH SHOULD INITIATE/SUPPORT A FEW THUNDERSTORMS
THOUGH COVERAGE AT THIS TIME APPEARS TO BE NO WORSE THAN 20-25
PERCENT AT ITS PEAK. WILL STILL NEED TO MONITOR UPSTREAM CONDITIONS
AS ANY CONVECTIVELY INDUCE VORT MAX IN THE NW FLOW WOULD LEAD TO
ENHANCE CONVECTIVE DEVELOPMENT OVER OUR REGION. EXPECT RATHER STEEP
LOW LEVEL LAPSE RATES MONDAY AFTERNOON WHICH SUGGEST A DECENT CHANCE
FOR STRONG GUSTY WINDS IN THE VICINITY OF ANY STORMS THAT OCCUR.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...
BY TUESDAY...UPPER RIDGE AMPLIFIES OVER THE CENTRAL U.S...EXTENDING
INTO THE NORTHERN PLAINS. THIS AMPLIFICATION WILL DEEPEN A L/W
TROUGH OVER ONTARIO/QUEBEC...INDUCING NWLY FLOW FROM THE GREAT LAKES
INTO THE CAROLINAS. THIS WILL SEND DISTURBANCES INTO OUR REGION AND
AN ENHANCED THREAT FOR SCATTERED CONVECTION BY TUESDAY. TIMING OF
THESE FEATURES DIFFICULT AND MODEL GUIDANCE IS USUALLY A LITTLE
TARDY. FOR NOW WILL MAINTAIN A CHANCE POP ACROSS THE
REGION...FAVORING TUESDAY AFTERNOON-EVENING. TEMPS TUESDAY DEPENDENT
ON TIMING OF SCATTERED CONVECTION AND EXTENT OF DEBRIS CLOUDINESS
UPSTREAM. FOR NOW WILL ADVERTISE MAX TEMPS ABOUT A CATEGORY LOWER
THAN MONDAY`S MAX TEMPS OVER THE NW THIRD WITH COMPARABLE TEMPS
ELSEWHERE.
WEDNESDAY THROUGH FRIDAY... UPPER RIDGE FLATTENS IN RESPONSE TO A
S/W CROSSING THE NORTHERN PLAINS. TUESDAY`S UPPER LEVEL SHEAR AXIS
PROJECTED TO LIE TO OUR SE ON WEDNESDAY WITH MAINLY WEAK ZONAL FLOW
OVERHEAD. THIS SET-UP CHANGES LITTLE ON THURSDAY. THIS SUGGEST HOT
CONDITIONS WITH MAINLY ISOLATED DIURNALLY DRIVEN CONVECTION BOTH
DAYS. MODEL GUIDANCE SUGGEST AN ENHANCED THREAT FOR CONVECTIVE
COVERAGE BY FRIDAY AS ANOTHER MID-UPPER LEVEL S/W APPROACHES FROM
THE NW. WILL GO WITH A CHANCE POP MOST LOCALES FRIDAY AND TEMPS
REMAINING A CATEGORY OR TWO ABOVE NORMAL.
&&
.AVIATION /11Z SATURDAY THROUGH WEDNESDAY/...
AS OF 700 AM SATURDAY...
24-HR TAF PERIOD: VFR CONDITIONS ARE GENERALLY EXPECTED TO PREVAIL
THIS MORNING AND INTO EARLY THIS AFTERNOON AT MOST LOCATIONS.
HOWEVER... WE COULD SEE SOME ISOLATED SHOWERS THIS MORNING ACROSS
THE PIEDMONT (MAINLY KGSO/KINT/KRDU). ISOLATED TO SCATTERED SHOWERS
AND STORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON AND EVENING WITH
THE APPROACH OF A MID LEVEL DISTURBANCE FROM THE NORTHWEST. IT NOW
APPEARS THE DISTURBANCE SHOULD MOVE ACROSS THE AREA IN A NORTHWEST
TO SOUTHEAST FASHION... WITH SHOWERS AND STORMS POSSIBLE IN THE
TRIAD BY EARLY AFTERNOON... TO MID TO LATE AFTERNOON ACROSS THE
SOUTHEASTERN PORTION OF THE AREA (KFAY). ANY STORMS WILL HAVE THE
POTENTIAL TO PRODUCE GUSTY WINDS AND SUB-VFR CONDITIONS. EXPECT ANY
SHOWERS AND STORMS SHOULD GENERALLY END BY MID EVENING... WITH ONLY
A SLIGHT CHANCE OF A FEW SHOWERS OVERNIGHT... ALONG WITH A SMALL
CHANCE OF PATCHY FOG.
LOOKING AHEAD: WEST TO NORTHWEST FLOW ALOFT WILL PREVAIL THROUGH
EARLY/MID NEXT WEEK...A RELATIVELY ENERGETIC SUMMER-TIME PATTERN IN
WHICH DIURNAL CONVECTION WILL POSE THE GREATEST CONCERN TO AVIATION.
NON-DIURNAL (I.E. OVERNIGHT) CONVECTION CANNOT BE RULED OUT IN THE
PRESENCE OF NW FLOW ALOFT...I.E. IF UPSTREAM MESOSCALE CONVECTIVE
SYSTEMS (MCS`S) PROPAGATE INTO THE REGION. MORNING STRATUS AND/OR
FOG WILL ALSO BE POSSIBLE EACH DAY GIVEN SEASONABLE MOISTURE...
PERIODS OF WEAK WARM ADVECTION... AND THE PRESENCE OF CONVECTION
DURING THE LATE EVENING HOURS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RAH
NEAR TERM...ELLIS/BSD
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...BSD/VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
700 AM EDT SAT JUL 18 2015
.SYNOPSIS...A SURFACE TROUGH WILL DEVELOP OVER THE AREA TODAY AND
REMAIN ACROSS THE REGION INTO NEXT WEEK. AN UPPER LEVEL DISTURBANCE
WILL TRACK SOUTHEASTWARD FROM FROM THE OHIO VALLEY THIS MORNING AND
ACROSS CENTRAL NC THIS AFTERNOON AND EVENING.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 305 AM SATURDAY...
TODAY: COMPLEX OF SHOWERS AND STORMS IS STILL GOING THIS MORNING
OVER PORTIONS OF EASTERN KY. HOWEVER... THE COMPLEX OF SHOWERS AND
STORMS IS SHOWING A DOWNWARD TREND IN INTENSITY AS IT SHIFTS EAST
AND SOUTHWARD. THE LATEST HRRR SHOWS THIS DISTURBANCE CONTINUING TO
WEAKEN THIS MORNING AS IT APPROACHES THE AREA. HOWEVER... AS THE
REMNANTS OF THE MCS MOVE ACROSS THE AREA LATE THIS MORNING AND INTO
THE AFTERNOON EXPECT WE SHOULD SEE REDEVELOPMENT ALONG AND AHEAD OF
THIS FEATURE... AND ALONG THE DEVELOPING LEE SIDE SURFACE TROUGH
ACROSS THE AREA FROM SW TO NE. WHILE THE LATEST HRRR SHOWS POSSIBLY
SOME ISOLATED CONVECTION DEVELOPING BY AS EARLY AS 12Z ACROSS THE
PIEDMONT... THINK THE BULK OF THE CONVECTION SHOULD OCCUR FROM THE
AFTERNOON INTO THE EVENING... DEVELOPING FIRST ACROSS THE PIEDMONT
(PROBABLY WESTERN PIEDMONT) THEN EXPANDING EAST AND SOUTHWARD.
THUS... WILL GO WITH SOLID CHANCE POPS FOR TODAY... EXPECTING
SCATTERED SHOWERS AND STORMS. WITH REGARD TO THE POTENTIAL FOR SVR
STORMS. MLCAPE VALUES ARE EXPECTED TO RANGE FROM GENERALLY 1000-2000
J/KG ACROSS THE AREA BY AFTERNOON AS THE AIRMASS CONTINUES TO
MOISTEN AND WARM IN THE WAKE OF THE DEPARTING SURFACE HIGH.
HOWEVER... DEEP LAYER SHEAR VALUES SHOULD GENERALLY BE LESS THAN 20-
25 KTS. THUS... WHILE WE COULD SEE SOME MULTICELLULAR ACTIVITY...
DONT EXPECT A LARGE LINE OF STORMS TO CROSS THE AREA. THE LATEST SPC
DAY 1 CONVECTIVE OUTLOOK HAS CENTRAL NC IN THE MARGINAL CATEGORY (A
FEW STRONG TO SEVERE STORMS POSSIBLE)... WHICH SEEMS REASONABLE
GIVEN THE ABOVE MENTIONED SETUP... WITH THE MAIN THREAT FROM
DAMAGING WIND GUSTS.
HIGH TEMPS TODAY ARE EXPECTED TO BE LARGELY DEPENDENT ON THE AMOUNT
OF DEBRIS CLOUD COVER FROM THE APPROACHING CONVECTIVE COMPLEX. HAVE
LOWERED PREVIOUS HIGH TEMPS BY A DEGREE OR TWO... GIVEN INCREASING
CLOUD COVER LATER TODAY... ALONG WITH THE DEVELOPMENT OF EXPECTED
STORMS THIS AFTERNOON. THUS... WILL GO WITH HIGH TEMPS IN THE LOWER
TO MID 90S.
TONIGHT AND SUNDAY: ANY LINGERING CONVECTION IS EXPECTED TO PUSH TO
THE SOUTH AND EAST OF THE AREA AND/OR DISSIPATE BY EARLY SUNDAY
MORNING... WITH MID LEVEL FEATURE SHIFTING TO THE SOUTH AND EAST OF
THE AREA. OVERNIGHT LOWS SHOULD BE WARM AGAIN FOR TONIGHT... WITH
LOWS GENERALLY EXPECTED IN THE LOWER TO MID 70S.
THE CENTER OF THE MID LEVEL RIDGE IS EXPECTED TO REMAIN OVER THE
SOUTH CENTRAL U.S. ON SUNDAY... WITH CENTRAL NC ON THE PERIPHERY OF
THE EXTENDING EASTWARD RIDGE AXIS. THIS SHOULD ALLOW FOR A
CONTINUATION OF WEST TO NORTHWEST FLOW ALOFT. HOWEVER... THE LATEST
GUIDANCE DOES NOT SHOW MUCH IN THE WAY OF ANY DISTURBANCES ALOFT
TRACKING ACROSS THE AREA ON SUNDAY. THUS... EXPECT ANY CONVECTIVE
ACTIVITY WILL BE MORE ISOLATED TO WIDELY SCATTERED. THIS COUPLED
WITH SLIGHTLY HIGHER AFTERNOON LOW LEVEL THICKNESS VALUES THAN
TODAYS SHOULD YIELD HIGH TEMPS IN THE MID TO UPPER 90S... WITH
POSSIBLY A FEW LOCATIONS TOUCHING 100 ACROSS THE SOUTH/SOUTHWESTERN
PORTION OF THE FA.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...
AN EXPANSIVE UPPER LEVEL RIDGE OVER THE SOUTHERN U.S. AND A LEE SIDE
TROUGH OVER THE PIEDMONT WILL PRODUCE HOT AND MOSTLY DRY WEATHER
FACTORS FOR CENTRAL NC ON MONDAY. LOW LEVEL THICKNESSES VARY BETWEEN
1440S TO AROUND 1450M IN THE AFTERNOON...INDICATIVE OF TEMPERATURES
WELL INTO THE 90S AND POSSIBLY REACHING THE CENTURY MARK. WITH SFC
DEWPOINTS IN THE UPPER 60S TO NEAR 70...HEAT INDICES 102-106 WILL BE
COMMON WITH A HEAT ADVISORY POSSIBLY WARRANTED...MAINLY IN THE
SANDHILLS AND SECTIONS OF THE COASTAL PLAIN.
THE SUB-TROPICAL AIR MASS WILL PRODUCE SLIGHT-MODERATE INSTABILITY
BY AFTERNOON WHICH SHOULD INITIATE/SUPPORT A FEW THUNDERSTORMS
THOUGH COVERAGE AT THIS TIME APPEARS TO BE NO WORSE THAN 20-25
PERCENT AT ITS PEAK. WILL STILL NEED TO MONITOR UPSTREAM CONDITIONS
AS ANY CONVECTIVELY INDUCE VORT MAX IN THE NW FLOW WOULD LEAD TO
ENHANCE CONVECTIVE DEVELOPMENT OVER OUR REGION. EXPECT RATHER STEEP
LOW LEVEL LAPSE RATES MONDAY AFTERNOON WHICH SUGGEST A DECENT CHANCE
FOR STRONG GUSTY WINDS IN THE VICINITY OF ANY STORMS THAT OCCUR.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...
BY TUESDAY...UPPER RIDGE AMPLIFIES OVER THE CENTRAL U.S...EXTENDING
INTO THE NORTHERN PLAINS. THIS AMPLIFICATION WILL DEEPEN A L/W
TROUGH OVER ONTARIO/QUEBEC...INDUCING NWLY FLOW FROM THE GREAT LAKES
INTO THE CAROLINAS. THIS WILL SEND DISTURBANCES INTO OUR REGION AND
AN ENHANCED THREAT FOR SCATTERED CONVECTION BY TUESDAY. TIMING OF
THESE FEATURES DIFFICULT AND MODEL GUIDANCE IS USUALLY A LITTLE
TARDY. FOR NOW WILL MAINTAIN A CHANCE POP ACROSS THE
REGION...FAVORING TUESDAY AFTERNOON-EVENING. TEMPS TUESDAY DEPENDENT
ON TIMING OF SCATTERED CONVECTION AND EXTENT OF DEBRIS CLOUDINESS
UPSTREAM. FOR NOW WILL ADVERTISE MAX TEMPS ABOUT A CATEGORY LOWER
THAN MONDAY`S MAX TEMPS OVER THE NW THIRD WITH COMPARABLE TEMPS
ELSEWHERE.
WEDNESDAY THROUGH FRIDAY... UPPER RIDGE FLATTENS IN RESPONSE TO A
S/W CROSSING THE NORTHERN PLAINS. TUESDAY`S UPPER LEVEL SHEAR AXIS
PROJECTED TO LIE TO OUR SE ON WEDNESDAY WITH MAINLY WEAK ZONAL FLOW
OVERHEAD. THIS SET-UP CHANGES LITTLE ON THURSDAY. THIS SUGGEST HOT
CONDITIONS WITH MAINLY ISOLATED DIURNALLY DRIVEN CONVECTION BOTH
DAYS. MODEL GUIDANCE SUGGEST AN ENHANCED THREAT FOR CONVECTIVE
COVERAGE BY FRIDAY AS ANOTHER MID-UPPER LEVEL S/W APPROACHES FROM
THE NW. WILL GO WITH A CHANCE POP MOST LOCALES FRIDAY AND TEMPS
REMAINING A CATEGORY OR TWO ABOVE NORMAL.
&&
.AVIATION /11Z SATURDAY THROUGH WEDNESDAY/...
AS OF 700 AM SATURDAY...
24-HR TAF PERIOD: VFR CONDITIONS ARE GENERALLY EXPECTED TO PREVAIL
THIS MORNING AND INTO EARLY THIS AFTERNOON AT MOST LOCATIONS.
HOWEVER... WE COULD SEE SOME ISOLATED SHOWERS THIS MORNING ACROSS
THE PIEDMONT (MAINLY KGSO/KINT/KRDU). ISOLATED TO SCATTERED SHOWERS
AND STORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON AND EVENING WITH
THE APPROACH OF A MID LEVEL DISTURBANCE FROM THE NORTHWEST. IT NOW
APPEARS THE DISTURBANCE SHOULD MOVE ACROSS THE AREA IN A NORTHWEST
TO SOUTHEAST FASHION... WITH SHOWERS AND STORMS POSSIBLE IN THE
TRIAD BY EARLY AFTERNOON... TO MID TO LATE AFTERNOON ACROSS THE
SOUTHEASTERN PORTION OF THE AREA (KFAY). ANY STORMS WILL HAVE THE
POTENTIAL TO PRODUCE GUSTY WINDS AND SUB-VFR CONDITIONS. EXPECT ANY
SHOWERS AND STORMS SHOULD GENERALLY END BY MID EVENING... WITH ONLY
A SLIGHT CHANCE OF A FEW SHOWERS OVERNIGHT... ALONG WITH A SMALL
CHANCE OF PATCHY FOG.
LOOKING AHEAD: WEST TO NORTHWEST FLOW ALOFT WILL PREVAIL THROUGH
EARLY/MID NEXT WEEK...A RELATIVELY ENERGETIC SUMMER-TIME PATTERN IN
WHICH DIURNAL CONVECTION WILL POSE THE GREATEST CONCERN TO AVIATION.
NON-DIURNAL (I.E. OVERNIGHT) CONVECTION CANNOT BE RULED OUT IN THE
PRESENCE OF NW FLOW ALOFT...I.E. IF UPSTREAM MESOSCALE CONVECTIVE
SYSTEMS (MCS`S) PROPAGATE INTO THE REGION. MORNING STRATUS AND/OR
FOG WILL ALSO BE POSSIBLE EACH DAY GIVEN SEASONABLE MOISTURE...
PERIODS OF WEAK WARM ADVECTION... AND THE PRESENCE OF CONVECTION
DURING THE LATE EVENING HOURS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RAH
NEAR TERM...BSD
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...BSD/VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
310 AM EDT SAT JUL 18 2015
.SYNOPSIS...A SURFACE TROUGH WILL DEVELOP OVER THE AREA TODAY AND
REMAIN ACROSS THE REGION INTO NEXT WEEK. AN UPPER LEVEL DISTURBANCE
WILL TRACK SOUTHEASTWARD FROM FROM THE OHIO VALLEY THIS MORNING AND
ACROSS CENTRAL NC THIS AFTERNOON AND EVENING.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 305 AM SATURDAY...
TODAY: COMPLEX OF SHOWERS AND STORMS IS STILL GOING THIS MORNING
OVER PORTIONS OF EASTERN KY. HOWEVER... THE COMPLEX OF SHOWERS AND
STORMS IS SHOWING A DOWNWARD TREND IN INTENSITY AS IT SHIFTS EAST
AND SOUTHWARD. THE LATEST HRRR SHOWS THIS DISTURBANCE CONTINUING TO
WEAKEN THIS MORNING AS IT APPROACHES THE AREA. HOWEVER... AS THE
REMNANTS OF THE MCS MOVE ACROSS THE AREA LATE THIS MORNING AND INTO
THE AFTERNOON EXPECT WE SHOULD SEE REDEVELOPMENT ALONG AND AHEAD OF
THIS FEATURE... AND ALONG THE DEVELOPING LEE SIDE SURFACE TROUGH
ACROSS THE AREA FROM SW TO NE. WHILE THE LATEST HRRR SHOWS POSSIBLY
SOME ISOLATED CONVECTION DEVELOPING BY AS EARLY AS 12Z ACROSS THE
PIEDMONT... THINK THE BULK OF THE CONVECTION SHOULD OCCUR FROM THE
AFTERNOON INTO THE EVENING... DEVELOPING FIRST ACROSS THE PIEDMONT
(PROBABLY WESTERN PIEDMONT) THEN EXPANDING EAST AND SOUTHWARD.
THUS... WILL GO WITH SOLID CHANCE POPS FOR TODAY... EXPECTING
SCATTERED SHOWERS AND STORMS. WITH REGARD TO THE POTENTIAL FOR SVR
STORMS. MLCAPE VALUES ARE EXPECTED TO RANGE FROM GENERALLY 1000-2000
J/KG ACROSS THE AREA BY AFTERNOON AS THE AIRMASS CONTINUES TO
MOISTEN AND WARM IN THE WAKE OF THE DEPARTING SURFACE HIGH.
HOWEVER... DEEP LAYER SHEAR VALUES SHOULD GENERALLY BE LESS THAN 20-
25 KTS. THUS... WHILE WE COULD SEE SOME MULTICELLULAR ACTIVITY...
DONT EXPECT A LARGE LINE OF STORMS TO CROSS THE AREA. THE LATEST SPC
DAY 1 CONVECTIVE OUTLOOK HAS CENTRAL NC IN THE MARGINAL CATEGORY (A
FEW STRONG TO SEVERE STORMS POSSIBLE)... WHICH SEEMS REASONABLE
GIVEN THE ABOVE MENTIONED SETUP... WITH THE MAIN THREAT FROM
DAMAGING WIND GUSTS.
HIGH TEMPS TODAY ARE EXPECTED TO BE LARGELY DEPENDENT ON THE AMOUNT
OF DEBRIS CLOUD COVER FROM THE APPROACHING CONVECTIVE COMPLEX. HAVE
LOWERED PREVIOUS HIGH TEMPS BY A DEGREE OR TWO... GIVEN INCREASING
CLOUD COVER LATER TODAY... ALONG WITH THE DEVELOPMENT OF EXPECTED
STORMS THIS AFTERNOON. THUS... WILL GO WITH HIGH TEMPS IN THE LOWER
TO MID 90S.
TONIGHT AND SUNDAY: ANY LINGERING CONVECTION IS EXPECTED TO PUSH TO
THE SOUTH AND EAST OF THE AREA AND/OR DISSIPATE BY EARLY SUNDAY
MORNING... WITH MID LEVEL FEATURE SHIFTING TO THE SOUTH AND EAST OF
THE AREA. OVERNIGHT LOWS SHOULD BE WARM AGAIN FOR TONIGHT... WITH
LOWS GENERALLY EXPECTED IN THE LOWER TO MID 70S.
THE CENTER OF THE MID LEVEL RIDGE IS EXPECTED TO REMAIN OVER THE
SOUTH CENTRAL U.S. ON SUNDAY... WITH CENTRAL NC ON THE PERIPHERY OF
THE EXTENDING EASTWARD RIDGE AXIS. THIS SHOULD ALLOW FOR A
CONTINUATION OF WEST TO NORTHWEST FLOW ALOFT. HOWEVER... THE LATEST
GUIDANCE DOES NOT SHOW MUCH IN THE WAY OF ANY DISTURBANCES ALOFT
TRACKING ACROSS THE AREA ON SUNDAY. THUS... EXPECT ANY CONVECTIVE
ACTIVITY WILL BE MORE ISOLATED TO WIDELY SCATTERED. THIS COUPLED
WITH SLIGHTLY HIGHER AFTERNOON LOW LEVEL THICKNESS VALUES THAN
TODAYS SHOULD YIELD HIGH TEMPS IN THE MID TO UPPER 90S... WITH
POSSIBLY A FEW LOCATIONS TOUCHING 100 ACROSS THE SOUTH/SOUTHWESTERN
PORTION OF THE FA.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...
AN EXPANSIVE UPPER LEVEL RIDGE OVER THE SOUTHERN U.S. AND A LEE SIDE
TROUGH OVER THE PIEDMONT WILL PRODUCE HOT AND MOSTLY DRY WEATHER
FACTORS FOR CENTRAL NC ON MONDAY. LOW LEVEL THICKNESSES VARY BETWEEN
1440S TO AROUND 1450M IN THE AFTERNOON...INDICATIVE OF TEMPERATURES
WELL INTO THE 90S AND POSSIBLY REACHING THE CENTURY MARK. WITH SFC
DEWPOINTS IN THE UPPER 60S TO NEAR 70...HEAT INDICES 102-106 WILL BE
COMMON WITH A HEAT ADVISORY POSSIBLY WARRANTED...MAINLY IN THE
SANDHILLS AND SECTIONS OF THE COASTAL PLAIN.
THE SUB-TROPICAL AIR MASS WILL PRODUCE SLIGHT-MODERATE INSTABILITY
BY AFTERNOON WHICH SHOULD INITIATE/SUPPORT A FEW THUNDERSTORMS
THOUGH COVERAGE AT THIS TIME APPEARS TO BE NO WORSE THAN 20-25
PERCENT AT ITS PEAK. WILL STILL NEED TO MONITOR UPSTREAM CONDITIONS
AS ANY CONVECTIVELY INDUCE VORT MAX IN THE NW FLOW WOULD LEAD TO
ENHANCE CONVECTIVE DEVELOPMENT OVER OUR REGION. EXPECT RATHER STEEP
LOW LEVEL LAPSE RATES MONDAY AFTERNOON WHICH SUGGEST A DECENT CHANCE
FOR STRONG GUSTY WINDS IN THE VICINITY OF ANY STORMS THAT OCCUR.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...
BY TUESDAY...UPPER RIDGE AMPLIFIES OVER THE CENTRAL U.S...EXTENDING
INTO THE NORTHERN PLAINS. THIS AMPLIFICATION WILL DEEPEN A L/W
TROUGH OVER ONTARIO/QUEBEC...INDUCING NWLY FLOW FROM THE GREAT LAKES
INTO THE CAROLINAS. THIS WILL SEND DISTURBANCES INTO OUR REGION AND
AN ENHANCED THREAT FOR SCATTERED CONVECTION BY TUESDAY. TIMING OF
THESE FEATURES DIFFICULT AND MODEL GUIDANCE IS USUALLY A LITTLE
TARDY. FOR NOW WILL MAINTAIN A CHANCE POP ACROSS THE
REGION...FAVORING TUESDAY AFTERNOON-EVENING. TEMPS TUESDAY DEPENDENT
ON TIMING OF SCATTERED CONVECTION AND EXTENT OF DEBRIS CLOUDINESS
UPSTREAM. FOR NOW WILL ADVERTISE MAX TEMPS ABOUT A CATEGORY LOWER
THAN MONDAY`S MAX TEMPS OVER THE NW THIRD WITH COMPARABLE TEMPS
ELSEWHERE.
WEDNESDAY THROUGH FRIDAY... UPPER RIDGE FLATTENS IN RESPONSE TO A
S/W CROSSING THE NORTHERN PLAINS. TUESDAY`S UPPER LEVEL SHEAR AXIS
PROJECTED TO LIE TO OUR SE ON WEDNESDAY WITH MAINLY WEAK ZONAL FLOW
OVERHEAD. THIS SET-UP CHANGES LITTLE ON THURSDAY. THIS SUGGEST HOT
CONDITIONS WITH MAINLY ISOLATED DIURNALLY DRIVEN CONVECTION BOTH
DAYS. MODEL GUIDANCE SUGGEST AN ENHANCED THREAT FOR CONVECTIVE
COVERAGE BY FRIDAY AS ANOTHER MID-UPPER LEVEL S/W APPROACHES FROM
THE NW. WILL GO WITH A CHANCE POP MOST LOCALES FRIDAY AND TEMPS
REMAINING A CATEGORY OR TWO ABOVE NORMAL.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 125 AM SATURDAY...
24-HR TAF PERIOD: VFR CONDITIONS ARE GENERALLY EXPECTED TO PREVAIL
THIS MORNING AND INTO EARLY THIS AFTERNOON AT MOST LOCATIONS.
HOWEVER... WE COULD SEE SOME PATCHY FOG DEVELOP THIS MORNING DURING
THE PRE-DAWN HOURS ACROSS THE COASTAL PLAIN AND SANDHILLS. FOG PRONE
KRWI APPEARS TO STAND THE BEST CHANCE OF SEEING SOME TEMPORARY SUB-
VFR VISBYS... THUS HAVE INTRODUCED A TEMPO GROUP BETWEEN 08-11Z THIS
MORNING FOR SUB-VFR VISBYS AT KRWI. ISOLATED TO SCATTERED SHOWERS
AND STORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON AND EVENING WITH
THE APPROACH OF A MID LEVEL DISTURBANCE FROM THE NORTHWEST. GIVEN
CONFIDENCE IS NOT HIGH IN NARROWING DOWN AN EXACT TIME AND COVERAGE
YET... HAVE ELECTED TO INCLUDE A PROB30 GROUP FOR THIS AFTERNOON
INTO THE EVENING FOR ALL SITES... WITH GUSTY WINDS AND SUB-VFR
CONDITIONS POSSIBLE WITH ANY STORMS.
LOOKING AHEAD: WEST TO NORTHWEST FLOW ALOFT WILL PREVAIL THROUGH
EARLY/MID NEXT WEEK...A RELATIVELY ENERGETIC SUMMER-TIME PATTERN IN
WHICH DIURNAL CONVECTION WILL POSE THE GREATEST CONCERN TO AVIATION.
NON-DIURNAL (I.E. OVERNIGHT) CONVECTION CANNOT BE RULED OUT IN THE
PRESENCE OF NW FLOW ALOFT...I.E. IF UPSTREAM MESOSCALE CONVECTIVE
SYSTEMS (MCS`S) PROPAGATE INTO THE REGION. MORNING STRATUS AND/OR
FOG WILL ALSO BE POSSIBLE EACH DAY GIVEN SEASONABLE MOISTURE...
PERIODS OF WEAK WARM ADVECTION... AND THE PRESENCE OF CONVECTION
DURING THE LATE EVENING HOURS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RAH
NEAR TERM...BSD
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...BSD/VINCENT
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1112 PM EDT SUN JUL 19 2015
.SYNOPSIS...
HOT AND HUMID WITH STORMS POSSIBLE AGAIN MONDAY. COLD FRONT
CROSSES TUESDAY...FOLLOWED BY A DRY MIDWEEK REPRIEVE.
&&
.NEAR TERM /THROUGH MONDAY/...
SECOND BATCH OF SHOWERS AND STORMS FALLING APART AS THEY CROSS THE
OH RIVER PER LATEST RADAR IMAGES. HIGH RESOLUTION MODELS DO NOT
BRING OTHER PERIODS OF PCPN OVERNIGHT. THEREFORE...DECREASED POPS
OVERNIGHT AND CANCELLED THE FLASH FLOOD WATCH FOR THE ENTIRE AREA.
PREVIOUS DISCUSSION BELOW...
ADJUSTED HOURLY POPS PER LATEST TRENDS ON DOPPLER RADAR. MOST OF
THE CONVECTION HAVE WEAKENED AS THE LINE OF SHOWERS AND STORMS
MOVED EAST. LIGHT PCPN REMAINS BEHIND THE MAIN LINE OF CONVECTION.
RADAR INDICATE ANOTHER ROUND OF STORMS CURRENTLY OVER CENTRAL
OH...EXPECTED TO CONTINUE TO MOVE EAST AND REACH SOUTHEAST OH AND
PORTIONS OF WV AROUND 02Z. LOWER HOURLY TEMPERATURES PER RECENT
SFC OBS.
REST OF FORECAST REMAINS ON TRACK.
PREVIOUS DISCUSSION BELOW...
LOOKING AT A FASTBALL OVER THE HEART OF THE PLATE AS AN MCS HAS
FORMED JUST UPSTREAM...OVER OHIO...THIS AFTERNOON. DOWNPOURS
ASSOCIATED WITH A THUNDERSTORMS COMPLEX LIKE THIS...EVEN WITH FAST
MOTION...WILL EASILY CAUSE HIGH WATER INCLUDING FLASH FLOODING
GIVEN EXCESSIVELY SATURATED GROUNDS THIS WET SUMMER. THIS SELF
PERPETUATING FEATURE WILL MOVE QUICKLY ACROSS THE AREA THROUGH
THIS EVENING IF NOT SOONER...BENEATH THE W UPPER LEVEL FLOW. THE
SYSTEM SPEED MAY BE FAST ENOUGH TO ALLOW TIME FOR OVERNIGHT
DEVELOPMENT OVERTOP OF THE WAKE COOL POOL.
FFA ISSUED THROUGH 08Z MON FOR ALL BUT FAR NORTHEASTERN COUNTIES
OF THE CWA.
THE WEATHER OUGHT TO SETTLE DOWN BY DAWN MON MORNING OR AT LEAST
LATER IN THE MORNING ON POST SUNRISE CLOUD TOP WARMING.
REDEVELOPMENT LATER MIN IS MOST LIKELY CENTRAL AND SOUTHERN
PORTIONS OF THE CWA...AS DRIER AIR PUNCHES IN ACROSS THE NORTHERN
TIER.
USED A MET/MAV/PREVIOUS/LAST NIGHT BLEND FOR NOT MUCH OVERALL
CHANGE ON LOWS TONIGHT...AND A MET/MAV/PREVIOUS BLEND FOR
SLIGHTLY HIGHER HIGHS MON...GUIDANCE WAS WELL CONVERGED&&
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
THE ACTIVE WEATHER PATTERN CONTINUES IN THE SHORT TERM PERIOD. A
FRONTAL BOUNDARY...WILL BE STALLED OUT ACROSS THE CWA MONDAY NIGHT
INTO EARLY TUESDAY...WITH ADDITIONAL UPPER DISTURBANCES MOVING
THROUGH THE CWA...TRIGGERING SHOWERS AND THUNDERSTORMS. THIS...WITH
THE HIGH MOISTURE CONTENT OF THE ATMOSPHERE...WILL KEEP FLASH
FLOODING A CONCERN...UNTIL AT LEAST LATER IN THE DAY TUESDAY....WHEN
A SECONDARY FRONT MOVES INTO THE REGION. BEHIND THIS FRONT...DRIER
AIR...DEW POINTS POSSIBLY INTO THE 50S TO EVEN 40S ACROSS THE
MOUNTAINS...AND COOLER TEMPERATURES. HIGH PRESSURE ACROSS THE AREA
WILL RESULT IN COOL...CLEARER NIGHTS...WITH FOG DEVELOPMENT A
POSSIBILITY IN THE MORNINGS.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
HIGH PRESSURE WILL GRADUALLY SLIDE OFF TO THE EAST BY FRIDAY INTO
SATURDAY...WITH MOISTURE GRADUALLY INCREASING...AND CHANCES FOR POPS
RETURNING...MAINLY ACROSS THE MOUNTAINS DURING PEAK HEATING HOURS.
ANOTHER SYSTEM WILL APPROACH THE AREA LATE IN THE WEEK...BRINGING A
RETURN OF SHOWERS AND THUNDERSTORMS.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
VERY BRIEF PERIODS OF IFR UNDER THUNDERSTORMS PASSING QUICKLY EAST
WHILE DIMINISHING IN INTENSITY. VCTS AT CKB...EKN AND BKW AT THE
BEGINNING OF THE PERIOD. THEN...THINGS GET COMPLICATED WITH THE
NEXT BATCH OF CONVECTION. THE HRRR MODEL KEEPS PCPN ACTIVITY ALIVE
WHILE CROSSING THE OH RIVER BY 05Z...AND CONTINUE TRACKING
SOUTHEAST TO AFFECT THE EXTREME SOUTHERN WV AND PORTIONS OF
SOUTHWEST VA OVERNIGHT.
ANY THUNDERSTORM CAN BRING IFR IN HEAVY RAIN ALONG WITH VERY
STRONG WIND GUSTS. OTHERWISE CONDITIONS WILL BE VFR TO AT TIMES
MVFR IN LOW CU/STRATOCU. IFR AREAS OF DENSE FOG MAY AGAIN FORM
OVERNIGHT TONIGHT...ESPECIALLY WHERE IT RAINS BEFOREHAND.
SFC FLOW LIGHT S TO SW AND LIGHT SW FLOW ALOFT INTO TONIGHT WILL
BECOME LIGHT W TO NW OVERNIGHT INTO MON.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z MONDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS...DUE TO THE SCATTERED NATURE OF
THUNDERSTORMS...SPECIFIC TIMING AND INTENSITY IS NOT INCLUDED IN THE
TAFS. FOG FORMATION OVERNIGHT TONIGHT WILL BE GREATLY ENHANCED
WHEREVER IT RAINS BEFOREHAND.
AFTER 00Z MONDAY... IFR IN SHOWERS/STORMS MONDAY NIGHT INTO
TUESDAY WITH FRONT IN THE AREA...AND IN FOG LATE TUESDAY NIGHT
INTO WEDNESDAY MORNING AND MAYBE AGAIN THE FOLLOWING NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/SL
NEAR TERM...ARJ/TRM
SHORT TERM...SL
LONG TERM...SL
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1041 PM EDT SUN JUL 19 2015
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL CONTINUE THIS EVENING AS AN UPPER
DISTURBANCE PUSHES EAST AND A WEAK COLD FRONT DROPS SOUTH ACROSS
THE AREA TONIGHT. MORE SHOWERS AND STORMS WILL DEVELOP ON MONDAY
AHEAD OF ANOTHER COLD FRONT THAT WILL PUSH THROUGH THE REGION
TUESDAY MORNING. A COOLER AND LESS HUMID AIRMASS WILL SETTLE IN
FOR THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
REMAINING CONVECTION CONTINUES TO WORK THROUGH THE ERN COUNTIES.
IT SHOULD BE EAST OF THE FA IN A FEW HOURS...LEAVING THE REST OF
THE NIGHT DRY. THE HEAVIEST RAINS HAVE COME TO AN END...SO
CANCELLED THE FLASH FLOOD WATCH.
CLOUDS SHOULD DECREASE ACROSS THE NRN COUNTIES AS THE NIGHT
PROGRESSES...BUT COULD LINGER ACROSS THE SOUTH.
A WEAK COLD FRONT WILL DROP SOUTHEASTWARD THROUGH THE ILN CWA
OVERNIGHT. LOW TEMPERATURES WILL BE THE COOLEST ACROSS THE
NORTHERN TIER OF COUNTIES IN THE MID 60S. ELSEWHERE THE
CONVECTION HAS CAUSED POCKETS OF COOLER LOCATIONS...TO LOWS WILL
RANGE FROM THE UPPER 60S TO LOWER 70S.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
THE WEAKENING COLD FRONT WILL STALL AND WASH OUT ALONG THE OHIO
RIVER MONDAY MORNING. ANOTHER SHORTWAVE WILL DIVE INTO THE OHIO
VALLEY FROM THE NORTHERN PLAINS BY LATE MONDAY AFTERNOON.
MEANWHILE...SURFACE LOW PRESSURE OVER HUDSON BAY WILL DRAG A COLD
FRONT THROUGH THE GREAT LAKES AND OHIO VALLEY REGION MONDAY NIGHT
INTO TUESDAY. THESE FORCING MECHANISMS WILL ALLOW FOR THE BEST
OPPORTUNITY FOR SHOWERS AND STORMS IN OUR AREA MONDAY AFTERNOON
AND EVENING. CONFIDENCE REMAINS LOW IN COVERAGE AND LOCATION...BUT
AT THIS TIME THE BETTER CHANCE LOOKS TO BE ACROSS MAINLY THE
SOUTHERN HALF OF THE CWA. 0-6 KM SHEAR VALUES WILL BE IN THE
20-40 KT RANGE WHILE MUCAPES WILL RANGE FROM AROUND 2000-3500
J/KG. HENCE...A CONTINUED POSSIBILITY FOR STRONG TO SEVERE STORMS
WITH THE POSSIBILITY OF SOME HEAVY RAINFALL. POTENTIAL FOR
CONVECTION WILL DIMINISH MONDAY NIGHT AS THE FRONT MOVES THROUGH
AND USHERS IN A COOLER AND LESS HUMID AIRMASS. HIGHS ON MONDAY
WILL BE IN THE MID 80S WITH TEMPERATURES DROPPING INTO THE UPPER
60S TO LOWER 70S MONDAY NIGHT.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
HAVE USED A BLEND OF THE GFS/ECMWF FOR THE IMMEDIATE LONG TERM.
THEREAFTER...HAVE USED A BLEND OF ECMWF/WPC GUIDANCE.
COLD FRONT TIMING FOR TUESDAY INTO TUESDAY NIGHT IS FASTER THAN
PREVIOUS RUNS. AS S/WV ENERGY DIGS EAST THROUGH THE GREAT
LAKES...THE FRONT WILL GRADUALLY BE PUSHED SOUTHEAST THROUGH THE
REMAINDER OF THE REGION. WILL MAINTAIN A CHANCE OF SHOWERS/STORMS
FOR ALL LOCATIONS ON TUESDAY..BUT THE THREAT SHOULD COME TO AN
END BY TUESDAY EVENING AS THE FRONT PUSHES AWAY AND DRIER AIR
BUILDS IN.
FOR THE PERIOD WEDNESDAY THROUGH SATURDAY...AS MID LEVEL RIDGE TRIES
TO REASSERT ITSELF NORTHWARD INTO THE PLAINS...WE WILL REMAIN IN A
NORTHWEST FLOW ALOFT. SURFACE HIGH PRESSURE IS EXPECTED TO TRAVERSE
OUR REGION. AT THIS TIME...IT SHOULD REMAIN DRY..
BY SUNDAY...ON THE BACK SIDE OF THE HIGH...WE WILL SEE AN INCREASE
IN LOW LEVEL MOISTURE. SOME DISTURBANCES IN THE NORTHWEST FLOW
ALOFT...COMBINED WITH INCREASED INSTABILITY...MAY BRING A THREAT OF
SHOWERS AND STORMS. GIVEN THIS IS WAY OUT IN THE EXTENDED...A
TYPICAL SUMMER 30 PERCENT CHANCE WILL BE EMPLOYED.
DRIER AIR AND SLIGHTLY BELOW NORMAL TEMPERATURES CAN BE EXPECTED
THROUGH AT LEAST FRIDAY...WITH AN UPTICK IN HIGHS BY THE WEEKEND.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
ANOTHER AREA OF THUNDERSTORMS IS WORKING THROUGH THE TAFS AS THE
PERIOD BEGINS. THIS IS ASSOCIATED WITH AN H5 VORT WORKING E
THROUGH THE FLOW. BASED ON LATEST RUNS OF THE HRRR AND RAP THIS
SHOULD BE THE LAST ROUND OF THE NIGHT. HAVE SOME MVFR VSBYS AND
WIND GUSTS FOR THE FIRST FEW HOURS IN THE NRN TAFS TAFS...BUT LEFT
CVG/LUK DRY.
EXPECT SKIES TO SCATTERED AGAIN OVERNIGHT...BEFORE SOME AC WORKS
BACK INTO CVG/LUK AROUND 09Z. CDFNT THAT IS FCST TO DROP INTO THE
FA TONIGHT WILL GRADUALLY WASH OUT TOMORROW. IT COULD ACT AS A
FOCUS FOR SOME SCATTERED PCPN AROUND CVG/LUK TOMORROW MORNING. THE
REST OF THE DAY LOOKS DRY.
IN THE CVG 30 HOUR...ADDITIONAL TSRA WILL BE POSSIBLE AHEAD OF
ANOTHER CDFNT.
OUTLOOK...THUNDERSTORMS POSSIBLE MONDAY NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...KURZ
NEAR TERM...SITES
SHORT TERM...KURZ
LONG TERM...HICKMAN
AVIATION...SITES
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
842 PM EDT SUN JUL 19 2015
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL CONTINUE THIS EVENING AS AN UPPER
DISTURBANCE PUSHES EAST AND A WEAK COLD FRONT DROPS SOUTH ACROSS
THE AREA TONIGHT. MORE SHOWERS AND STORMS WILL DEVELOP ON MONDAY
AHEAD OF ANOTHER COLD FRONT THAT WILL PUSH THROUGH THE REGION
TUESDAY MORNING. A COOLER AND LESS HUMID AIRMASS WILL SETTLE IN
FOR THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
A COMPLEX OF SHOWERS AND THUNDERSTORMS WHICH DEVELOPED AHEAD OF A
POTENT VORT MAX CURRENTLY OVER INDIANA ARE RAPIDLY PUSHING OFF TO
THE EAST. RECENT HRRR RUNS HANDLED THIS CONVECTIVE ACTIVITY FAIRLY
WELL AND ALSO ARE PINPOINTING ANOTHER CLUSTER OF SHOWERS AND
STORMS DEVELOPING LATE THIS AFTERNOON OVER INDIANA AND SHOWS THEM
MOVING INTO THE ILN CWA AROUND 22-23Z. COVERAGE FOR THIS NEXT
ROUND OF ACTIVITY IS NOT EXPECTED TO BE AS WIDESPREAD AS
EARLIER...BUT IT SHOULD DIMINISH AND MOVE OUT OF THE ILN AREA BY
AROUND 04Z. RAIN RATES WITH THIS FIRST ROUND OF STORMS THIS
AFTERNOON WERE NOT EXTREMELY HIGH BUT CONSIDERING VERY WET SOILS
IN MANY AREAS...PW/S INCREASING TO OVER 2 INCHES ACROSS THE
CWA...AND FAVORABLE WARM CLOUD DEPTHS...WILL ALLOW THE FLASH FLOOD
WATCH TO CONTINUE THROUGH 04Z. 0-6KM SHEAR WILL INCREASE A BIT
THROUGH THIS EVENING TO AROUND 20-30 KNOTS SO CANNOT RULE OUT AN
ISOLATED STORM OR TWO...BUT DAMAGING WIND POTENTIAL WILL BE
DIMINISHING AS DCAPES WILL DROP BELOW 1000 J/KG LATE THIS
AFTERNOON INTO EARLY EVENING.
A WEAK COLD FRONT WILL DROP SOUTHEASTWARD THROUGH THE ILN CWA
OVERNIGHT...SO TONIGHT/S LOW TEMPERATURES AND DEWPOINTS WILL BE A
TAD LOWER ACROSS THE NORTHERN HALF OF THE CWA TONIGHT AS A RESULT.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
THE WEAKENING COLD FRONT WILL STALL AND WASH OUT ALONG THE OHIO
RIVER MONDAY MORNING. ANOTHER SHORTWAVE WILL DIVE INTO THE OHIO
VALLEY FROM THE NORTHERN PLAINS BY LATE MONDAY AFTERNOON.
MEANWHILE...SURFACE LOW PRESSURE OVER HUDSON BAY WILL DRAG A COLD
FRONT THROUGH THE GREAT LAKES AND OHIO VALLEY REGION MONDAY NIGHT
INTO TUESDAY. THESE FORCING MECHANISMS WILL ALLOW FOR THE BEST
OPPORTUNITY FOR SHOWERS AND STORMS IN OUR AREA MONDAY AFTERNOON
AND EVENING. CONFIDENCE REMAINS LOW IN COVERAGE AND LOCATION...BUT
AT THIS TIME THE BETTER CHANCE LOOKS TO BE ACROSS MAINLY THE
SOUTHERN HALF OF THE CWA. 0-6 KM SHEAR VALUES WILL BE IN THE
20-40 KT RANGE WHILE MUCAPES WILL RANGE FROM AROUND 2000-3500
J/KG. HENCE...A CONTINUED POSSIBILITY FOR STRONG TO SEVERE STORMS
WITH THE POSSIBILITY OF SOME HEAVY RAINFALL. POTENTIAL FOR
CONVECTION WILL DIMINISH MONDAY NIGHT AS THE FRONT MOVES THROUGH
AND USHERS IN A COOLER AND LESS HUMID AIRMASS. HIGHS ON MONDAY
WILL BE IN THE MID 80S WITH TEMPERATURES DROPPING INTO THE UPPER
60S TO LOWER 70S MONDAY NIGHT.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
HAVE USED A BLEND OF THE GFS/ECMWF FOR THE IMMEDIATE LONG TERM.
THEREAFTER...HAVE USED A BLEND OF ECMWF/WPC GUIDANCE.
COLD FRONT TIMING FOR TUESDAY INTO TUESDAY NIGHT IS FASTER THAN
PREVIOUS RUNS. AS S/WV ENERGY DIGS EAST THROUGH THE GREAT
LAKES...THE FRONT WILL GRADUALLY BE PUSHED SOUTHEAST THROUGH THE
REMAINDER OF THE REGION. WILL MAINTAIN A CHANCE OF SHOWERS/STORMS
FOR ALL LOCATIONS ON TUESDAY..BUT THE THREAT SHOULD COME TO AN
END BY TUESDAY EVENING AS THE FRONT PUSHES AWAY AND DRIER AIR
BUILDS IN.
FOR THE PERIOD WEDNESDAY THROUGH SATURDAY...AS MID LEVEL RIDGE TRIES
TO REASSERT ITSELF NORTHWARD INTO THE PLAINS...WE WILL REMAIN IN A
NORTHWEST FLOW ALOFT. SURFACE HIGH PRESSURE IS EXPECTED TO TRAVERSE
OUR REGION. AT THIS TIME...IT SHOULD REMAIN DRY..
BY SUNDAY...ON THE BACK SIDE OF THE HIGH...WE WILL SEE AN INCREASE
IN LOW LEVEL MOISTURE. SOME DISTURBANCES IN THE NORTHWEST FLOW
ALOFT...COMBINED WITH INCREASED INSTABILITY...MAY BRING A THREAT OF
SHOWERS AND STORMS. GIVEN THIS IS WAY OUT IN THE EXTENDED...A
TYPICAL SUMMER 30 PERCENT CHANCE WILL BE EMPLOYED.
DRIER AIR AND SLIGHTLY BELOW NORMAL TEMPERATURES CAN BE EXPECTED
THROUGH AT LEAST FRIDAY...WITH AN UPTICK IN HIGHS BY THE WEEKEND.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
ANOTHER AREA OF THUNDERSTORMS IS WORKING THROUGH THE TAFS AS THE
PERIOD BEGINS. THIS IS ASSOCIATED WITH AN H5 VORT WORKING E
THROUGH THE FLOW. BASED ON LATEST RUNS OF THE HRRR AND RAP THIS
SHOULD BE THE LAST ROUND OF THE NIGHT. HAVE SOME MVFR VSBYS AND
WIND GUSTS FOR THE FIRST FEW HOURS IN THE NRN TAFS TAFS...BUT LEFT
CVG/LUK DRY.
EXPECT SKIES TO SCATTERED AGAIN OVERNIGHT...BEFORE SOME AC WORKS
BACK INTO CVG/LUK AROUND 09Z. CDFNT THAT IS FCST TO DROP INTO THE
FA TONIGHT WILL GRADUALLY WASH OUT TOMORROW. IT COULD ACT AS A
FOCUS FOR SOME SCATTERED PCPN AROUND CVG/LUK TOMORROW MORNING. THE
REST OF THE DAY LOOKS DRY.
IN THE CVG 30 HOUR...ADDITIONAL TSRA WILL BE POSSIBLE AHEAD OF
ANOTHER CDFNT.
OUTLOOK...THUNDERSTORMS POSSIBLE MONDAY NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR OHZ026-034-
035-042>046-051>056-060>065-070>074-077>082-088.
KY...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR KYZ089>100.
IN...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR INZ050-058-
059-066-073>075-080.
&&
$$
SYNOPSIS...KURZ
NEAR TERM...KURZ
SHORT TERM...KURZ
LONG TERM...HICKMAN
AVIATION...SITES
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
742 PM EDT SUN JUL 19 2015
.SYNOPSIS...
MCS CROSSES THIS EVENING. HOT AND HUMID WITH STORMS POSSIBLE AGAIN
MONDAY. COLD FRONT CROSSES TUESDAY...FOLLOWED BY A DRY MIDWEEK
REPRIEVE.
&&
.NEAR TERM /THROUGH MONDAY/...
ADJUSTED HOURLY POPS PER LATEST TRENDS ON DOPPLER RADAR. MOST OF
THE CONVECTION HAVE WEAKENED AS THE LINE OF SHOWERS AND STORMS
MOVED EAST. LIGHT PCPN REMAINS BEHIND THE MAIN LINE OF CONVECTION.
RADAR INDICATE ANOTHER ROUND OF STORMS CURRENTLY OVER CENTRAL
OH...EXPECTED TO CONTINUE TO MOVE EAST AND REACH SOUTHEAST OH AND
PORTIONS OF WV AROUND 02Z. LOWER HOURLY TEMPERATURES PER RECENT
SFC OBS.
REST OF FORECAST REMAINS ON TRACK.
LOOKING AT A FASTBALL OVER THE HEART OF THE PLATE AS AN MCS HAS
FORMED JUST UPSTREAM...OVER OHIO...THIS AFTERNOON. DOWNPOURS
ASSOCIATED WITH A THUNDERSTORMS COMPLEX LIKE THIS...EVEN WITH FAST
MOTION...WILL EASILY CAUSE HIGH WATER INCLUDING FLASH FLOODING
GIVEN EXCESSIVELY SATURATED GROUNDS THIS WET SUMMER. THIS SELF
PERPETUATING FEATURE WILL MOVE QUICKLY ACROSS THE AREA THROUGH
THIS EVENING IF NOT SOONER...BENEATH THE W UPPER LEVEL FLOW. THE
SYSTEM SPEED MAY BE FAST ENOUGH TO ALLOW TIME FOR OVERNIGHT
DEVELOPMENT OVERTOP OF THE WAKE COOL POOL.
FFA ISSUED THROUGH 08Z MON FOR ALL BUT FAR NORTHEASTERN COUNTIES
OF THE CWA.
THE WEATHER OUGHT TO SETTLE DOWN BY DAWN MON MORNING OR AT LEAST
LATER IN THE MORNING ON POST SUNRISE CLOUD TOP WARMING.
REDEVELOPMENT LATER MIN IS MOST LIKELY CENTRAL AND SOUTHERN
PORTIONS OF THE CWA...AS DRIER AIR PUNCHES IN ACROSS THE NORTHERN
TIER.
USED A MET/MAV/PREVIOUS/LAST NIGHT BLEND FOR NOT MUCH OVERALL
CHANGE ON LOWS TONIGHT...AND A MET/MAV/PREVIOUS BLEND FOR
SLIGHTLY HIGHER HIGHS MON...GUIDANCE WAS WELL CONVERGED&&
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
THE ACTIVE WEATHER PATTERN CONTINUES IN THE SHORT TERM PERIOD. A
FRONTAL BOUNDARY...WILL BE STALLED OUT ACROSS THE CWA MONDAY NIGHT
INTO EARLY TUESDAY...WITH ADDITIONAL UPPER DISTURBANCES MOVING
THROUGH THE CWA...TRIGGERING SHOWERS AND THUNDERSTORMS. THIS...WITH
THE HIGH MOISTURE CONTENT OF THE ATMOSPHERE...WILL KEEP FLASH
FLOODING A CONCERN...UNTIL AT LEAST LATER IN THE DAY TUESDAY....WHEN
A SECONDARY FRONT MOVES INTO THE REGION. BEHIND THIS FRONT...DRIER
AIR...DEW POINTS POSSIBLY INTO THE 50S TO EVEN 40S ACROSS THE
MOUNTAINS...AND COOLER TEMPERATURES. HIGH PRESSURE ACROSS THE AREA
WILL RESULT IN COOL...CLEARER NIGHTS...WITH FOG DEVELOPMENT A
POSSIBILITY IN THE MORNINGS.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
HIGH PRESSURE WILL GRADUALLY SLIDE OFF TO THE EAST BY FRIDAY INTO
SATURDAY...WITH MOISTURE GRADUALLY INCREASING...AND CHANCES FOR POPS
RETURNING...MAINLY ACROSS THE MOUNTAINS DURING PEAK HEATING HOURS.
ANOTHER SYSTEM WILL APPROACH THE AREA LATE IN THE WEEK...BRINGING A
RETURN OF SHOWERS AND THUNDERSTORMS.
&&
.AVIATION /23Z SUNDAY THROUGH FRIDAY/...
VERY BRIEF PERIODS OF IFR UNDER THUNDERSTORMS PASSING QUICKLY EAST
WHILE DIMINISHING IN INTENSITY. VCTS AT CKB...EKN AND BKW AT THE
BEGINNING OF THE PERIOD. THEN...THINGS GET COMPLICATED WITH THE
NEXT BATCH OF CONVECTION. THE HRRR MODEL KEEPS PCPN ACTIVITY ALIVE
WHILE CROSSING THE OH RIVER BY 05Z...AND CONTINUE TRACKING
SOUTHEAST TO AFFECT THE EXTREME SOUTHERN WV AND PORTIONS OF
SOUTHWEST VA OVERNIGHT.
ANY THUNDERSTORM CAN BRING IFR IN HEAVY RAIN ALONG WITH VERY
STRONG WIND GUSTS. OTHERWISE CONDITIONS WILL BE VFR TO AT TIMES
MVFR IN LOW CU/STRATOCU. IFR AREAS OF DENSE FOG MAY AGAIN FORM
OVERNIGHT TONIGHT...ESPECIALLY WHERE IT RAINS BEFOREHAND.
SFC FLOW LIGHT S TO SW AND LIGHT SW FLOW ALOFT INTO TONIGHT WILL
BECOME LIGHT W TO NW OVERNIGHT INTO MON.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z MONDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS...DUE TO THE SCATTERED NATURE OF
THUNDERSTORMS...SPECIFIC TIMING AND INTENSITY IS NOT INCLUDED IN THE
TAFS. FOG FORMATION OVERNIGHT TONIGHT WILL BE GREATLY ENHANCED
WHEREVER IT RAINS BEFOREHAND.
AFTER 00Z MONDAY... IFR IN SHOWERS/STORMS MONDAY NIGHT INTO
TUESDAY WITH FRONT IN THE AREA...AND IN FOG LATE TUESDAY NIGHT
INTO WEDNESDAY MORNING AND MAYBE AGAIN THE FOLLOWING NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLASH FLOOD WATCH UNTIL 4 AM EDT MONDAY FOR WVZ005>011-013>020-
024>031-033>039.
OH...FLASH FLOOD WATCH UNTIL 4 AM EDT MONDAY FOR OHZ066-067-075-076-
083>087.
KY...FLASH FLOOD WATCH UNTIL 4 AM EDT MONDAY FOR KYZ101>103-105.
VA...FLASH FLOOD WATCH UNTIL 4 AM EDT MONDAY FOR VAZ003-004.
&&
$$
SYNOPSIS...TRM/SL
NEAR TERM...ARJ/TRM
SHORT TERM...SL
LONG TERM...SL
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
328 PM EDT SAT JUL 18 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE REGION ON SUNDAY. HIGH PRESSURE
WILL BUILD OVER NORTHERN OHIO AND NORTHWESTERN PENNSYLVANIA
BRIEFLY ON MONDAY BEFORE ANOTHER COLD FRONT MOVES THROUGH THE
FORECAST AREA ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
HEAT ADVISORY IS IN EFFECT THIS EVENING FOR NORTHWEST OHIO. WITH
THE SHOWERS AND THUNDERSTORMS OVER THE AREA AND THE DEBRIS CLOUD
FROM THIS SYSTEM...HEAT INDEX VALUES WILL NOT EXCEED ADVISORY
CRITERIA. I WILL CANCEL THE HEAT ADVISORY WITH THE ISSUANCE OF
THIS FORECAST. SHOWERS AND THUNDERSTORMS ARE MOVING THROUGH THE
NORTHWEST PARTS OF THE FORECAST AREA THIS AFTERNOON. THESE STORMS
HAVE FORMED ON AN OUTFLOW BOUNDARY FROM THUNDERSTORMS OVERNIGHT.
THE HRRR SHOWS THESE STORMS SLOW PROGESSING EAST THIS AFTERNOON
BUT DECREASING IN INTENSITY. THE MODELS SUGGEST THE STORMS SHOULD
FALL APART BEFORE REACHING THE I-71 CORRIDOR. I HAVE PLACED
SCATTERED POPS IN THE FORECAST FOR AREAS WEST OF I-71. THE LAKE
BREEZE IS GENERATING A FEW SHOWERS OVER NORTHWEST PA. BASED ON
CURRENT SATELLITE IMAGERY THESE SHOWERS COULD ALSO EXTENDED INTO
NORTHEAST OHIO. I WILL PLACE SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS IN THESE AREAS. .
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY NIGHT/...
A COLD FRONT IS EXPECTED TO MOVE ACROSS THE FORECAST
AREA ON SUNDAY. THE UPPER LEVEL SUPPORT WITH THIS FRONT IS FAIRLY
WEAK BUT THERE IS PLENTY OF INSTABILITY IN THE LOWER ATMOSPHERE.
DEW POINTS IN THE 70S ARE WIDESPREAD OVER MUCH OF THE FORECAST AREA.
MODEL GUIDANCE VARIES SLIGHTLY WITH THE POPS ON SUNDAY WITH THE
PASSAGE OF THE FRONT RANGING BETWEEN 30 TO 60 PERCENT. I AM LEANING
TOWARD THE HIGHER POP RANGE WITH THE HIGH DEWPOINT UNSTABLE AIR
MASS. SHOWERS AND THUNDERSTORMS WILL ALSO PRODUCE HEAVY RAIN AND
ISOLATED FLASH FLOODING IS NOT OUT OF THE QUESTION. I DO NOT
BELIEVE THE THREAT IS WIDESPREAD ENOUGH TO WARRANT A FLASH FLOOD
WATCH BUT WE WILL MONITOR THE SITUATION. HIGH PRESSURE WILL BRIEFLY
BUILD OVER THE REGION ON MONDAY. ANOTHER COLD FRONT WILL MOVE
THROUGH THE FORECAST AREA ON TUESDAY. I WILL KEEP THE THUNDERSTORM
PROBABILITIES IN THE SCATTERED CATEGORY FOR TUESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
HIGH PRESSURE LOOKS TO BE IN CONTROL OF THE WEATHER ACROSS THE
REGION WEDNESDAY THROUGH FRIDAY. HOWEVER WE WILL NEED TO MONITOR THE
LAKE BREEZE THURSDAY INTO FRIDAY FOR THE POTENTIAL FOR SOME ISOLATED
CONVECTION. CHANCES ARE LOW ENOUGH TO KEEP FROM THE ZONES FOR NOW.
OTHERWISE PARTLY CLOUDY/MOSTLY CLEAR CONDITIONS ARE ANTICIPATED.
THE COOL DAY OF THE LONG TERM WILL BE WEDNESDAY WITH HIGHS RANGING
FROM THE MID 70S TO LOWER 80S. WARMER THURSDAY AND FRIDAY WITH HIGHS
VERY CLOSE TO SEASONAL AVERAGES.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
OUTFLOW FROM CONVECTIVE ACTIVITY OVER MICHIGAN WILL AT LEAST MOVE
ACROSS NW OHIO THIS AFTERNOON. MODELS HAVE VERY POOR HANDLE ON
THE EVOLUTION OF THE THUNDERSTORMS INTO THE EVENING. HAVE PLACED
THE MAIN EMPHASIS OF THE CONVECTION TO AN AREA NEAR AND WEST OF A
KCLE TO KMFD LINE THROUGH AROUND 00Z. THINKING IS THAT THE
EASTERN TAF SITES MAY REMAIN DRY BUT WILL CONTINUE TO MONITOR
CLOSELY AND ADJUST AS NEEDED. IFR CONDITIONS ARE ANTICIPATED WITH
THE STRONGER THUNDERSTORMS. THESE STORMS WILL BE CAPABLE OF
PRODUCING GUSTY WINDS AS WELL.
AFTER THESE LEADING THUNDERSTORMS DECREASE AROUND SUNSET OUR
ATTENTION WILL BE BACK TO THE CENTRAL GREAT LAKES AGAIN AS WE
AWAIT ANOTHER MCS TO DEVELOP ALONG AND AHEAD OF A COLD FRONT THAT
WILL IMPACT THE REGION SUNDAY NIGHT INTO MONDAY. OUTFLOW AND
OVERALL BETTER LOW LEVEL FLOW ON SUNDAY SHOULD BE ENOUGH FOR
THUNDER TO REDEVELOP BY LATE MORNING ACROSS NW OHIO.
WINDS WILL GENERALLY BE FROM THE SOUTHWEST AT 10 TO 15 KNOTS BUT
MUCH STRONGER IN AND NEAR THUNDERSTORMS.
OUTLOOK...AREAS OF NON VFR IN SHRA AND TSRA SUNDAY INTO MONDAY
THEN MORE ISOLATED TUE AND WED.
&&
.MARINE...
POTENTIAL FOR SOME THUNDERSTORMS TO MOVE ACROSS THE LAKE OVERNIGHT
INTO SUNDAY AHEAD OF COLD FRONT. THIS WEAK COLD FRONT WILL CROSS
LAKE ERIE LATE SUNDAY NIGHT INTO MONDAY MORNING WITH A BRIEF PERIOD
OF NORTHERLY WINDS. ANOTHER WEAK FRONT WILL MOVE ACROSS THE REGION
MONDAY NIGHT. HIGH PRESSURE WILL FINALLY RETURN TO THE REGION ON
WEDNESDAY AND PERSIST INTO THURSDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GARNET
NEAR TERM...GARNET
SHORT TERM...GARNET
LONG TERM...MULLEN
AVIATION...MULLEN
MARINE...MULLEN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
302 PM EDT SAT JUL 18 2015
.SYNOPSIS...
VERY WARM AND HUMID CONDITIONS WILL CONTINUE THROUGH SUNDAY BEFORE
A COLD FRONT SETTLES SOUTHWARD THROUGH THE AREA AND COOLS AND
DRIES THE AIRMASS ENOUGH TO REMOVE THE DANGEROUS HEAT INDICES THAT
ARE FELT DURING THE WEEKEND. GIVEN AN EXTREMELY WARM AND UNSTABLE
AIRMASS...SHOWERS AND STORMS MAY DEVELOP AT TIMES THROUGH THE
WEEKEND WITH THE POTENTIAL TO BE STRONG TO SEVERE. THE BEST CHANCE
OF WIDESPREAD STORMS WILL BE SUNDAY AFTERNOON AND EVENING...BUT
CHANCES WILL EXIST THROUGH TONIGHT AS WELL.
&&
.NEAR TERM /THROUGH TONIGHT/...
STILL VERY DIFFICULT/LOW CONFIDENCE FORECAST - AS MAJORITY OF
CONVECTION ALLOWING HIGH RESOLUTION GUIDANCE CONTINUES TO STRUGGLE
MIGHTILY WITH THE EXTREMELY UNSTABLE...WEAKLY SHEARED...AND WEAKLY
FORCED ENVIRONMENT OVER THE OHIO VALLEY. DESPITE RISING HEIGHTS
OVER THE OHIO VALLEY TODAY...A CLUSTER OF STORMS HAS MAINTAINED
ITSELF INTO NWRN OHIO AND IS BEING WATCHED FOR GROWTH/DEVELOPMENT
ON PROPAGATING OUTFLOWS WITH MLCAPE IN EXCESS OF 3500 J/KG
ENTRENCHED OVER THE ILN FORECAST AREA VIA DEW POINTS IN THE MID
70S AND TEMPERATURES APPROACHING/AROUND 90F. DESPITE WEAK SHEAR
/0-6KM BULK SHEAR ABOUT 20KTS AND 0-3KM SHEAR FROM 10 TO
15KTS/...THERE IS CONCERN IN THE SHORT TERM FOR STORMS TO GROW
UPSCALE ON COLD-POOL BALANCED SYSTEM WITH INSTBY /DCAPE TO 1500
J/KG/ COMPENSATING FOR LACK OF SHEAR. SHOULD THIS OCCUR IT WOULD
SEEM A EVOLVING LINE OF STORMS MAY AFFECT MUCH OF THE CWA THIS
AFTERNOON INTO THIS EVENING WITH A WIND DAMAGE THREAT.
ALSO A COMPLICATING FACTOR...VERY WEAK/SUBTLE MCV EMINTATING OUT
OF THE CENTRAL MISSISSIPPI VALLEY MAY SPARK N-S BAND OF LOOSELY
ORGANIZED STORMS OVER INDIANA LATER THIS AFTERNOON WHICH MAY MOVE
INTO THE AREA BEFORE DIMINISHING.
LASTLY...SOME INDICATIONS IN SOME OF THE HIGHER RES GUIDANCE OF A
LATE NIGHT MCS/BOW ECHO MOVING FROM THE UPPER MISSISSIPPI VALLEY
INTO THE GREAT LAKES/OHIO VALLEY LATER IN THE NIGHT.
CONFIDENCE IS EXTREMELY LOW GIVEN HRRR INABILITY TO PROPERLY
HANDLE ONGOING CONVECTION...AND VERY POOR HANDLING OF LAST NIGHT/S
WEAKLY FORCED ACTIVITY. THUS...WILL RUN WITH STORM CHANCES MOST
AREAS FROM THE LATE AFTERNOON THROUGH THE NIGHT AND UPDATE
ACCORDINGLY AS OPPORTUNITIES PRESENT TO INCREASE RAIN CHANCES.
A VERY HUMID NIGHT IS EXPECTED /ASSUMING MCS COLD POOLS REMAIN
LOCALIZED/ WITH SOME RECORD HIGH MINIMUM TEMPS POSSIBLE IN THE
METRO AREAS. EXCESSIVE HEAT WARNING CONTINUES ALL NIGHT FOR URBAN
AREAS OF HAMILTON COUNTY...AND HEAT ADVISORIES ELSEWHERE WILL COME
DOWN BY SUNSET.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
EXPECT ANY REMNANT MCS ACTIVITY /LOW CONFIDENCE HERE/ THAT IS
STILL AROUND ON SUNDAY MORNING TO QUICKLY SHIFT OFF AND WEAKEN
LEAVING ANOTHER VERY WARM/HUMID DAY ON TAP. DEW POINTS WILL RALLY
BACK INTO THE MID 70S AHEAD OF MODERATELY STRONG COLD FRONT
APPROACHING THE AREA FROM THE NORTHWEST BY MIDDAY. THINK TEMPS
WILL BE A TOUCH COOLER MOST AREAS...WITH UPPER 80S TO AROUND 90
EXPECTED...AND MAY BE MORE SO IF CLOUD DEBRIS FROM UPSTREAM MCS
ACTIVITY IS APPRECIABLE. THUS...DO NOT FEEL COMFORTABLE EXTENDING
HEAT ADVISORY BEYOND EXTREME SW OHIO...SERN INDIANA...AND NRN KY
WHERE IT IS CURRENTY PLACED. HEAT INDICES AREA-WIDE THOUGH WILL BE
95-100F AND HIGHEST IN THE ADVISORY AREA /LOW 100S LIKELY/.
ADVISORY MAY NEED TO BE EXPANDED NORTH/EAST A BIT IF BETTER
INSOLATION THAN WHAT IS EXPECTED DEVELOPS.
CONVECTION SHOULD INITIATE BY 18Z ACROSS NRN OH BACK INTO INDIANA
AND SINK SSE INTO THE AREA. PRETTY STRONG AGREEMENT IN THE
GUIDANCE OF A FAIRLY SOLID LINE OF STORMS AMIDST STRONG INSTBY BUT
AGAIN MODEST TO MARGINAL SHEAR. WIND DAMAGE TO BE THE MAIN THREAT
BUT 0-3KM SHEAR VECTORS...WHILE IN GOOD ORIENTATION TO THE
FORCING...ARE A LITTLE WEAK IN MAGNITUDE. HOWEVER LIKE RECENT
DAYS...EXTREME INSTBY/DCAPE MAY AUGMENT. MAY ALSO BE A FLASH FLOOD
THREAT GIVEN ORIENTATION OF LINE BUT STORMS SHOULD PROPOGATE TO
SOME DEGREE SO WILL HOLD ON A FLASH FLOOD WATCH FOR NOW. EXPECT
LINE TO SETTLE THROUGH AND OUT OF THE AREA LATER IN THE EVENING
WITH SKIES TURNING CLEAR/PARTLY CLOUDY IN ITS WAKE.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
COLD FRONT WILL BE NEAR OR JUST SOUTH OF THE OHIO RIVER BY MONDAY
MORNING WHERE IT WILL BECOME QUASI STATIONARY DURING THE DAY. WEAK
DISTURBANCES WITHIN THE FLOW ALOFT ALONG WITH THE BOUNDARY MEANS
THAT A CHANCE OF SHOWERS AND THUNDERSTORMS HAVE TO BE KEPT INTO THE
FORECAST FOR THESE LOCATIONS.
FOR MONDAY NIGHT INTO TUESDAY NIGHT...HAVE USED A BLEND OF THE NAM-
WRF AND ECMWF FOR TIMING OF NEXT S/WV ENERGY IN DEVELOPING NORTHWEST
FLOW ALOFT ALONG WITH ANOTHER COLD FRONT. AS S/WV ENERGY DIGS EAST
THROUGH THE GREAT LAKES...ANOTHER FRONT WILL GRADUALLY BE PUSHED
SOUTHEAST THROUGH THE REGION. WILL PLACE A CHANCE OF SHOWERS/STORMS
FOR ALL LOCATIONS BY TUESDAY MORNING AND CONTINUE THAT THREAT
THROUGH THE DAY. AS THE FRONT DROPS SOUTH OF THE OHIO RIVER BY
WEDNESDAY MORNING...AND WITH THE LOSS OF DAYTIME HEATING...PCPN
THREAT WILL PUSH SOUTH AND DIMINISH OVERNIGHT.
FOR THE PERIOD WEDNESDAY THROUGH FRIDAY...AS MID LEVEL RIDGE TRIES
TO REASSERT ITSELF NORTHWARD INTO THE PLAINS...WE WILL REMAIN IN A
NORTHWEST FLOW ALOFT. SURFACE HIGH PRESSURE IS EXPECTED TO TRAVERSE
OUR REGION. AT THIS TIME...IT SHOULD REMAIN DRY...EXCEPT FOR ALONG
AND SOUTH OF THE OHIO ON WEDNESDAY...WHERE LINGERING INSTABILITY MAY
POP A DIURNAL SHOWER OR STORM.
WILL CONTINUE THE DRY WEATHER INTO SATURDAY BUT BY THAT TIME MODELS
SUGGEST THAT ANOTHER WEAK FRONT MAY ARRIVE BY THEN OR SUNDAY.
TEMPERATURES WILL BE NEAR OR SLIGHTLY BELOW NORMAL THROUGH THURSDAY
WITH MAINLY TYPICAL JULY READINGS BY THE END OF THE WEEK.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
WHILE THE ABOVE NEAR-TERM DISCUSSION SHOWS THE THOUGHT PROCESS OF
STORMS DEVELOPING THIS AFTERNOON AND EVENING...PUTTING THEM AT A
POINT WITH ANY CONSIDERABLE CERTAINTY IS DIFFICULT. WILL CONTINUE
TO LEAVE MENTION OF THUNDERSTORMS OUT OF TAFS ATTM BUT USE A VCTS
AT KDAY WHERE THE PROBABILITY IS HIGHER THAN EVERYWHERE ELSE GIVEN
THE EXPECTED SE SLIDE OF AN MCS LATER TONIGHT.
THE MCS IS A LOW PROBABILITY OF OCCURRENCE BUT WILL HAVE A HIGH
IMPACT IF IT DOES. WILL KEEP AN EYE OUT ON UPSTREAM
OBS...PARTICULARLY RADAR AND SATELLITE AND AMEND WHEN THE SYSTEM
DEVELOPS OR MODELS APPEAR TO PICK UP ON WHAT IS BEING FORECAST
RIGHT NOW. EXPECT VFR CONDITIONS UNTIL CONVECTION POPS LATER TODAY
AND WHEN/IF MVFR FOG HITS RIVER VALLEYS AND KLUK TONIGHT.
OUTLOOK...THUNDERSTORMS POSSIBLE SUNDAY THROUGH TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR OHZ026-034-035-
042>046-051>056-060>065-072>074-079>082-088.
HEAT ADVISORY UNTIL 8 PM EDT SUNDAY FOR OHZ070-071-078.
EXCESSIVE HEAT WARNING UNTIL 8 PM EDT SUNDAY FOR OHZ077.
KY...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR KYZ097>100.
HEAT ADVISORY UNTIL 8 PM EDT SUNDAY FOR KYZ089>096.
IN...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR INZ050-058-059.
HEAT ADVISORY UNTIL 8 PM EDT SUNDAY FOR INZ066-073>075-080.
&&
$$
SYNOPSIS...BINAU
NEAR TERM...BINAU
SHORT TERM...BINAU
LONG TERM...HICKMAN
AVIATION...FRANKS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
932 AM EDT SAT JUL 18 2015
.SYNOPSIS...
WEAK HIGH PRESSURE WILL REMAIN OVER THE REGION TODAY AND TONIGHT.
A COLD FRONT WILL MOVE SOUTHEAST ACROSS THE LOCAL AREA SUNDAY
EVENING AND NIGHT. A STRONGER AREA OF HIGH PRESSURE WILL BUILD IN
BEHIND THE FRONT FOR THE START OF THE NEW WORKWEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
REMNANTS OF THE OVERNIGHT MCS SYSTEM ARE MOVING SOUTHEAST ACROSS
LAKE MICHIGAN. THE SYSTEM IS WEAKENING BUT LAYING OUTFLOW
BOUNDARIES OVER LOWER MICHIGAN. SPC DISCUSSION INDICATES NEW
THUNDERSTORM DEVELOPMENT MAY OCCUR ON THESE BOUNDARIES LATER THIS
AFTERNOON. THE HRRR MODEL SUPPORTS THIS AND INDICATES SOME
THUNDERSTORMS MAY REACH NW OHIO BY MID AFTERNOON. I HAVE ADDED A
SLIGHT CHANCE OF THUNDERSTORMS FOR THIS AFTERNOON FOR THE
NORTHWEST PART OF OUR COUNTY WARNING AREA. I WILL MONITOR THE
TRENDS AND THE PRECIPITATION CHANCES MAY NEED TO BE INCREASED WITH
THE NEXT UPDATE. TEMPERATURES APPEAR TO BE ON TRACK. 12Z DTX
SOUNDING INDICATES A MAX TEMP OF 88 WITH FULL SUN. THE ONLY
LIMITING FACTOR COULD BE THE CLOUD COVER FROM THE MCS. HOWEVER
WITH DEWPOINTS IN THE MID 70S AND THE RECENT COOL
SPELL...TEMPERATURES NEAR HEAT INDEX CRITERIA WILL FEEL VERY
UNCOMFORTABLE FOR MOST. I WILL LEAVE THE HEAT ADVISORY UNCHANGED.
PREVIOUS FORECAST...
THE SLIGHTLY DRIER AIR THAT WAS OVER INDIANA EARLIER IN THE NIGHT
HAS SPREAD ACROSS NW OHIO. THIS HAS CAUSED DEWPOINTS TO DIP INTO
THE MIDDLE 60S. THIS DRYING WILL BE BRIEF AS DEWPOINTS WILL CLIMB
BACK INTO THE 70S SHORTLY. SOME DEBRIS CLOUDS FROM THE CONVECTION
OVER WISCONSIN WILL EVENTUALLY FIND THEIR WAY TO THE AREA. THESE
SHOULD BE THIN SO NO CHANGES TO TEMPS.
PREVIOUS...NO CHANGES TO THE HEAT ADVISORY TODAY. WESTERN AREAS
WILL REACH MINIMAL CRITERIA. EXPECT SURFACE DEWPOINTS TO SURGE
INTO THE MIDDLE 70S BY 18Z. MIXING LATE IN THE AFTERNOON MAY CAUSE
THEM TO DROP BACK INTO THE LOWER 70S. GIVEN HOW GREEN AND MOIST IT
IS AT GROUND LEVEL CANNOT SEE TEMPS GETTING WARMER THAN GUIDANCE
NUMBERS TODAY. ABOUT THE WEST HALF OF THE AREA SHOULD REACH 90
WITH UPPER 80S MOST OF THE REST OF THE AREA.
THE NEXT CHALLENGE TODAY WILL BE PRECIP CHANCES. CURRENTLY A FEW
STORMS OVER EASTERN LAKE ERIE. THESE MAY CLIP NW PA THE NEXT FEW
HOURS. AFTER THAT AM GOING TO TRY FOR A DRY FORECAST. EVEN THOUGH THERE
WILL BE VERY IMPRESSIVE CAPES OF 4000 J/KG LATER TODAY DO NOT SEE
A SUITABLE LIFTING MECHANISM. IT IS POSSIBLE THAT THE LAKE BREEZE
BOUNDARY COULD KICK OFF A FEW STORMS BUT GIVEN THE FACT THAT 700MB
TEMPS WILL REACH PLUS 10 TODAY...THE ATMOSPHERE WILL BE CAPPED. DO
EXPECT A FEW POP UPS THIS AFTERNOON BUT COVERAGE WILL BE NO MORE
THAN 5 PERCENT SO COMFORTABLE GOING DRY. THE CURRENT ACTIVITY NEAR
CHICAGO SHOULD DISSIPATE AND ACTIVITY MOVING INTO WISCONSIN SHOULD
PASS TO THE NORTH IF IT HOLDS TOGETHER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
HUMID AIR WILL REMAIN OVER THE AREA TONIGHT AND SUNDAY. WILL START
TO SEE INCREASING PRECIP CHANCES LATE TONIGHT AS MID LEVELS BEGIN
TO SLOWLY COOL. BETTER CHANCES WILL COME SUNDAY AFTERNOON AND
EVENING AS A COLD FRONT APPROACHES FROM THE NORTHWEST. THIS FRONT
WILL BE SOUTH OF THE AREA BY DAYBREAK MONDAY. THE AREA WILL BE
OUTLOOKED FOR SEVERE WEATHER WITH THE FRONTAL PASSAGE AND THIS
SEEMS REASONABLE GIVEN THE AIRMASS. THE AREA COULD SEE A SQUALL
LINE DEVELOP AND MOVE THROUGH LATE SUNDAY. HAVE BUMPED PRECIP
CHANCES TO THE LIKELY CATEGORY ALL AREAS BASED ON THIS SCENARIO.
BY DAYBREAK MONDAY THE ENTIRE AREA SHOULD BE DRY. HIGH PRESSURE
WILL THEN BUILD OVER THE REGION RESULTING IN DRY WEATHER THROUGH
THE END OF THE PERIOD.
GIVEN THE PRECIP AND MORE CLOUDS EXPECTED ON SUNDAY...TEMPS WILL
BE A TAD COOLER THAN TODAY. SHOULD NOT NEED ANY HEAT HEADLINES.
THE AIRMASS BEHIND THE FRONT DOES NOT APPEAR TO BE QUITE AS COOL
AS EARLIER THOUGHT SO HAVE BUMPED HIGH TEMPS UP A LITTLE FOR
MONDAY AND A FEW DEGREES FOR TUESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
STRETCH OF DRY WEATHER SEEMS TO BE SETTING UP FOR THE LONG RANGE.
MODELS CONTINUE TO BE IN GOOD AGREEMENT FOR WEDNESDAY WITH SURFACE
HIGH PRESSURE MOVING SE OVER THE ENTIRE AREA. MODELS NOW INDICATE
SURFACE HIGH TO REMAIN OVER THE AREA INTO THE WEEKEND. YDY ECMWF
HAD SHORT WAVE MOVING ACROSS THE AREA ON FRIDAY. NOW THE ECMWF IS
COMING INTO LINE WITH THE GFS...KEEPING HIGH PRESSURE OVER THE
ENTIRE AREA INTO NEXT WEEKEND. SO HAVE REMOVED ALL MENTION OF
PRECIP FOR THE LONG RANGE FORECAST.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
PREDOMINATELY VFR CONDITIONS WILL CONTINUE TODAY. THIS AFTERNOON
CAPES SOAR TO 5,000 J/KG. HOWEVER WELL CAPED AT 700MB WITH NO
DISCERNIBLE TRIGGER. THAT SAID COULD SEE ISOLATED TSRA POP UP
ALMOST ANYWHERE THIS AFTERNOON...HOWEVER DID NOT PUT ANY TSRA IN
TAF BECAUSE IS SHOULD BE ISOLATED.
&&
.MARINE...
POTENTIAL FOR A FEW SHOWERS AND THUNDERSTORMS TODAY...BUT
OTHER THAN THAT THE LAKE WILL BE RATHER QUIET THIS WEEKEND AS HIGH
PRESSURE REMAINS OVER THE OHIO VALLEY. MODELS CONTINUE TO HOLD OFF
NEXT COLD FRONT UNTIL MONDAY. CONDITIONS MAY GET CHOPPY FOR A TIME
AS WIND SPEEDS INCREASE TO 15 KNOTS...BUT WILL REMAIN BELOW SMALL
CRAFT ADVISORY CRITERIA.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR OHZ003-006>009-
017>019-027-028-036.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KUBINA
NEAR TERM...KUBINA
SHORT TERM...GARNET
LONG TERM...DJB
AVIATION...DJB
MARINE...DJB
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
607 AM EDT SAT JUL 18 2015
.SYNOPSIS...
HOT AND HUMID FOR THE WEEKEND. SOME AFTERNOON THUNDERSTORMS
POSSIBLE. COLD FRONT IN VICINITY EARLY IN WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
NAM DOES NOT HAVE THE COMPLEX MOVING THROUGH EARLY THIS MORNING...SO
NOT SURE THAT THE MOISTURE FIELDS ARE REPRESENTATIVE AT LATER TIMES.
THEREFORE WILL RELY MORE ON THE HRRR AND THE GFS WHICH HANDLE THE
COMPLEX A BIT BETTER...THOUGH NOT PERFECTLY. THIS WILL ALLOW FOR
SOME THUNDERSTORMS TODAY...BUT DRY AIR PUNCHING IN FROM THE WEST
WILL LIMIT ACTIVITY TO THE MOUNTAINS BY LATER THIS AFTERNOON. THIS
DRY AIR WILL ALSO CAP THE AREA DURING THE EVENING AND OVERNIGHT
HOURS. WITH THE MOIST GROUND...MET MOS LOOKS WAY TO HIGH FOR TODAYS
HIGHS. WILL STAY CLOSER TO THE GFS MOS.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
A VERY SIMILAR DAY AS TODAY
IS EXPECTED ON SUNDAY WITH JUST AN ISOLATED SHOT A SHOWER OR STORM
AND MAINLY OVER THE HIGH TERRAIN. BY SUNDAY EVENING...A S/W TROF AND
ASSOCIATED COLD FRONT WILL MAKE A RUN INTO THE AREA WITH A LINE OF
SHOWERS AND STORMS...SOME OF WHICH MAY BE ON THE STRONG SIDE OVER SE
OH. HAVE SOME LIKELY POPS OVER MUCH OF THE AREA SUNDAY NIGHT UNTIL
THE TROF CAN PASS AND THE FRONT SLIP S. WHILE THE UPPER LEVEL
DISTURBANCE PASSES SAFELY THRU...THE SAME CANNOT BE SAID FOR THE
SURFACE BOUNDARY WHICH WILL RETURN N INTO THE AREA LATE MONDAY AND
BECOME NEARLY QUASI STATIONARY. THIS COMBINED WITH GOOD INSTABILITY
AND SOME PERTURBATIONS IN THE UPPER LEVEL FLOW...MEANS A RENEWED
FLASH FLOOD THREAT MONDAY NIGHT AND TUESDAY.
THINK BEST SHOT OF REACHING HEAT ADV CRITERIA ON SUNDAY WOULD
GENERALLY BE ALONG AND S OF I64. OTHERWISE...UPPER 80S TO LOW 90S
COMBINED WITH DEWPOINTS IN THE LOW 70S MEANS HEAT INDICES IN THE MID
TO UPPER 90S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
COLD FRONT WILL MOVE INTO THE AREA ON MONDAY. THERE IS THE
POTENTIAL FOR A FEW STRONG TO SEVERE STORMS ON MONDAY...BUT THIS
IS STILL UP IN THE AIR A BIT...AND WILL RELY SOMEWHAT ON TIMING OF
FRONT. FRONTAL BOUNDARY WILL EVENTUALLY STALL OUT ACROSS THE
SOUTHERN HALF OF THE AREA BRIEFLY...BEFORE SAGGING SOUTH LATER IN
THE DAY ON TUESDAY. HOWEVER...ANOTHER SYSTEM WILL AFFECT THE AREA
MID TO LATE WEEK. THUS...HEADING INTO YET ANOTHER WET
PERIOD...WITH THE POTENTIAL FOR CONTINUED WATER PROBLEMS.
HIGHLIGHTED IN THE HWO.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
SOME SHOWERS AND THUNDERSTORMS WILL CAUSE SOME BRIEF RESTRICTIONS
EARLY THIS MORNING...OTHERWISE GENERALLY VFR CONDITIONS WILL
PREVAIL.A CUMULUS DECK WILL THEN FORM TODAY...STARTING A BIT
LOWER THAN NORMAL DUE TO THE HIGH HUMIDITY. SOME SCATTERED AFTERNOON
THUNDERSTORMS CAN BE EXPECTED IN THE MOUNTAINS. THESE ARE NOT
EXPECTED TO LINGER INTO THE EVENING HOURS AS DRY AIR WILL PUSH IN
FROM THE WEST. SOME MVFR FOG IS POSSIBLE SATURDAY NIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z SUNDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS...
DUE TO THE SCATTERED AND LIMITED NATURE OF ANY IFR/MVFR CONDITIONS
IN SHOWERS AND THUNDERSTORMS...SPECIFIC CONDITIONS ARE NOT INCLUDED
IN THE TAFS.
AFTER 12 SUNDAY...
IFR IN MORE WIDESPREAD SHOWERS/STORMS SUNDAY NIGHT OR MONDAY NEAR
FRONT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/30
NEAR TERM...RPY
SHORT TERM...30
LONG TERM...SL
AVIATION...RPY
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
249 AM EDT SAT JUL 18 2015
.SYNOPSIS...
HOT AND HUMID FOR THE WEEKEND. SOME AFTERNOON THUNDERSTORMS
POSSIBLE. COLD FRONT IN VICINITY EARLY IN WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
NAM DOES NOT HAVE THE COMPLEX MOVING THROUGH EARLY THIS MORNING...SO
NOT SURE THAT THE MOISTURE FIELDS ARE REPRESENTATIVE AT LATER TIMES.
THEREFORE WILL RELY MORE ON THE HRRR AND THE GFS WHICH HANDLE THE
COMPLEX A BIT BETTER...THOUGH NOT PERFECTLY. THIS WILL ALLOW FOR
SOME THUNDERSTORMS TODAY...BUT DRY AIR PUNCHING IN FROM THE WEST
WILL LIMIT ACTIVITY TO THE MOUNTAINS BY LATER THIS AFTERNOON. THIS
DRY AIR WILL ALSO CAP THE AREA DURING THE EVENING AND OVERNIGHT
HOURS. WITH THE MOIST GROUND...MET MOS LOOKS WAY TO HIGH FOR TODAYS
HIGHS. WILL STAY CLOSER TO THE GFS MOS.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/... A VERY SIMILAR DAY AS TODAY
IS EXPECTED ON SUNDAY WITH JUST AN ISOLATED SHOT A SHOWER OR STORM
AND MAINLY OVER THE HIGH TERRAIN. BY SUNDAY EVENING...A S/W TROF AND
ASSOCIATED COLD FRONT WILL MAKE A RUN INTO THE AREA WITH A LINE OF
SHOWERS AND STORMS...SOME OF WHICH MAY BE ON THE STRONG SIDE OVER SE
OH. HAVE SOME LIKELY POPS OVER MUCH OF THE AREA SUNDAY NIGHT UNTIL
THE TROF CAN PASS AND THE FRONT SLIP S. WHILE THE UPPER LEVEL
DISTURBANCE PASSES SAFELY THRU...THE SAME CANNOT BE SAID FOR THE
SURFACE BOUNDARY WHICH WILL RETURN N INTO THE AREA LATE MONDAY AND
BECOME NEARLY QUASI STATIONARY. THIS COMBINED WITH GOOD INSTABILITY
AND SOME PERTURBATIONS IN THE UPPER LEVEL FLOW...MEANS A RENEWED
FLASH FLOOD THREAT MONDAY NIGHT AND TUESDAY.
THINK BEST SHOT OF REACHING HEAT ADV CRITERIA ON SUNDAY WOULD
GENERALLY BE ALONG AND S OF I64. OTHERWISE...UPPER 80S TO LOW 90S
COMBINED WITH DEWPOINTS IN THE LOW 70S MEANS HEAT INDICES IN THE MID
TO UPPER 90S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
COLD FRONT WILL MOVE INTO THE AREA ON MONDAY. THERE IS THE
POTENTIAL FOR A FEW STRONG TO SEVERE STORMS ON MONDAY...BUT THIS
IS STILL UP IN THE AIR A BIT...AND WILL RELY SOMEWHAT ON TIMING OF
FRONT. FRONTAL BOUNDARY WILL EVENTUALLY STALL OUT ACROSS THE
SOUTHERN HALF OF THE AREA BRIEFLY...BEFORE SAGGING SOUTH LATER IN
THE DAY ON TUESDAY. HOWEVER...ANOTHER SYSTEM WILL AFFECT THE AREA
MID TO LATE WEEK. THUS...HEADING INTO YET ANOTHER WET
PERIOD...WITH THE POTENTIAL FOR CONTINUED WATER PROBLEMS.
HIGHLIGHTED IN THE HWO.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
THE REMAINS OF A COMPLEX WILL MOVE THROUGH EASTERN KY...SOUTHERN
WV...AND SOUTHWESTERN VA EARLY THIS MORNING. SOME HEAVIER
THUNDERSTORMS COULD BRIEFLY CAUSE SOME IFR OR MVFR CONDITIONS...BUT
VFR CONDITIONS WILL PREVAIL FOR THE MAJORITY OF THE TIME.
A CUMULUS DECK WILL THEN FORM ON SATURDAY...STARTING A BIT LOWER
THAN NORMAL DUE TO THE HIGH HUMIDITY. SOME SCATTERED AFTERNOON
THUNDERSTORMS CAN BE EXPECTED IN THE MOUNTAINS. THESE ARE NOT
EXPECTED TO LINGER INTO THE EVENING HOURS AS DRY AIR WILL PUSH IN
FROM THE WEST.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z SUNDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS...DUE TO THE SCATTERED AND LIMITED NATURE OF ANY
IFR/MVFR CONDITIONS IN HEAVY RAIN THIS MORNING...THESE CONDITIONS
ARE NOT INCLUDED IN THE BKW TAF...JUST LIGHTER PRECIPITATION.
AFTER 06Z SUNDAY...
IFR IN MORE WIDESPREAD SHOWERS/STORMS SUNDAY NIGHT OR MONDAY NEAR
FRONT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/30
NEAR TERM...RPY
SHORT TERM...30
LONG TERM...SL
AVIATION...RPY
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1129 PM EDT SUN JUL 19 2015
.SYNOPSIS...
A PAIR OF COLD FRONTS WILL PUSH SOUTHEAST ACROSS THE REGION
TONIGHT AND ON TUESDAY. HIGH PRESSURE WILL BUILD OVER PENNSYLVANIA
DURING THE SECOND HALF OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
930 PM...
HEAT ADVISORY FOR SE HAS ENDED.
ONGOING CLUSTER OF SEVERE WEATHER ALONG I-80 CORRIDOR THIS MID
EVENING LOOKS LIKE IT WILL GRADUALLY WEAKEN OVER NEXT FEW HOURS.
WW443 CONTINUES FOR THIS REGION...BUT HAS BEEN SCALED BACK ALONG
NORTHERN BORDER WHERE THREAT HAS ENDED.
BEGAN TO TAPER POPS BACK GRADUALLY LATE THIS EVENING AND ESP
OVERNIGHT...THOUGH THREAT FOR SHOWERS/POSS A TSTM WILL PERSIST
UNTIL COLD FROPA.
6 PM...
EARLY CONVECTION WHICH POPPED UP IN THE HEAT OVER THE CENTRAL
MOUNTAINS HAVE DISSIPATED. OTHER THAN A FEW SPECKLES
ELSEWHERE...THE ONLY GAME IN TOWN IS NOW THE STORMS OVER THE FAR
NW. LOTS OF STORMS SEEM TO SPLIT AND LEAVE THE LEFT-MOVER AS THE
STRONGER CELL. SO HAIL IS ALSO A THREAT WITH THE WIND DAMAGE STILL
THE MAIN THREAT. HAIL MAY END UP MELTING DOWN SOME EVEN IF IT WAS
LARGE ALOFT DUE TO HOT TEMPS AND DEEP WARM CLOUD DEPTH. TWEAKS
MAINLY FOR TIMING AND PLACEMENT.
PREV...
SEVERE THUNDERSTORM WATCH #443 IS NOW IN EFFECT FOR THE NORTHERN
HALF OF CENTRAL PA THROUGH 11 PM EDT. PRELIMINARY CELLS FIRING
DUE TO DIURNAL DESTABILIZATION AND BOUNDARY LAYER THERMAL RIDGE
PUSHING EAST OF MY AREA. HOTTEST DAY OF SUMMER THUS FAR IN
PROGRESS WITH APPARENT TEMPS SURGING INTO THE 90S THROUGHOUT.
HEAT INDICES WILL TOP OUT BETWEEN 100F AND 104F ACROSS THE SUSQ
VALLEY.
VERY WARM ALOFT WITH BOUNDARY LAYER CAPPING OF EARLIER TOWERS
NOW DECREASING AS CIN ANALYSIS SHOWS DESTABLIZATION OCCURRING
OVER LAKE ERIE AND NORTHWEST PA. JUST ONE HOUR AGO...ELEVATED
HEAT SOURCE SHOWERS BRIEFLY SPROUTED OVER SOUTH MOUNTAIN BEFORE
MOVING OFF THE TERRAIN AND QUICKLY DISSIPATING. SIMILAR SHOWERS
TRYING TO GROW OVER PORTIONS OF THE CENTRAL MOUNTAINS...AND ARE
NOW OVERCOMING THE CAP. HRRR DOES DEVELOP AND PROPAGATE THIS
ISOLD TO SCT SHRA/TSRA AREA SIMILAR TO SAT EVENING ACTIVITY BEFORE
DISSIPATING IT WITH THE DECREASE IN DIURNAL HEATING BY 00Z.
MAIN ACTIVITY EXPECTED WITH APPROACHING SHORTWAVE/COLD FRONT FROM
THE EASTERN GLAKS THIS EVENING THROUGH LATE TONIGHT. NO REAL
CHANGES TO PREVIOUS THINKING...WITH NORTHERN AREAS STANDING THE
GREATEST THREAT OF STRONG TO LOCALLY SEVERE STORMS...AS THE PARENT
SHORTWAVE WILL LIFT WELL NORTH OF THE REGION THIS EVENING. FAR
SOUTHEAST MAY BE HARD PRESSED TO RAIN FROM THIS FRONT AS A RESULT
LATE TONIGHT...AS GREATER DISTANCE FROM THE WANING LG SCALE
FORCING ACCOMPANIES FROPA FURTHER SOUTH. THUS TAPERING POPS TO THE
SOUTHEAST WILL BE MAINTAINED.
COOLER/DRIER AIR IN WAKE OF COLD FRONT SHOULD MAKE SOME INROADS
ACROSS THE NW MTNS...WHERE LOWS IN THE L60S EXPECTED TONIGHT. THE
REST OF CENTRAL PA WILL REMAIN IN MUGGY AIR MASS FOR ANOTHER NIGHT
WITH LOWS BTWN 70-75F SOUTH OF I-80.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
STALLED OUT COLD FRONT NR THE MASON DIXON LINE WILL BE THE FOCUS
FOR SCT PM CONVECTION ON MONDAY. ELSEWHERE...ARRIVAL OF LOW PWAT
AIR ACROSS NORTHERN PA SHOULD ENSURE A DRY DAY. ENS MEAN 8H TEMPS
ARE SUPPORTIVE OF HIGHS FROM THE L80S OVR THE N MTNS...TO THE L90S
ACROSS THE LOWER SUSQ VALLEY.
DID NOT CHANGE MUCH ON THIS PERIOD. DID GO WITH A DRY FCST FOR THE
MORNING HOURS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
HARD TO SEE A LOT GOING ON AFTER THIS EVENING...DUE TO THE LACK
OF SFC CONVERGENCE.
DID GO WITH SOME CHC POPS LATER MONDAY INTO TUE. HIGHEST CHC
ON TUE...AS SECONDARY FRONT DROPS SE.
AFTER THIS...LOOKING AT MAINLY DRY WEATHER WED INTO FRIDAY.
SOME MODELS LIKE THE GFS40 HAVE SOME SHOWERS IN THE SW ON THU.
LEFT FCST DRY FOR NOW.
MAIN CHANGE WAS TO LOWER TEMPS MORE FOR THE PERIOD WED INTO
FRIDAY. MAIN FACTORS ARE LOWER 500 MB HEIGHTS ON THE MODELS LATELY
ALSO THE TENDENCY FOR THE AIRMASS BEHIND COLD FRONTS TO BE COLDER
THAN FCST LATELY. ALSO THE WET GROUND.
MID SHIFT DID PUT SOME SHOWERS IN FOR THE FIRST PART OF THE
WEEKEND. SOME MODELS SHOW VERY STRONG WARM ADVECTION AND
DIRECTIONAL SHEAR INTO AT LEAST NW PA ON SUNDAY. EC NOT REALLY
SHOWING MUCH OF THIS. FOR NOW...DID CARRY SHOWERS INTO SUNDAY.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
SHOWERS AND THUNDERSTORMS CONTINUE TO STREAM THROUGH THE CENTRAL
AND NORTHWESTERN PORTIONS OF THE STATE BRINGING TSRA TO UNV AND TO
BFD THROUGH 05Z. CURRENT RADAR SHOWS THESE SHOWERS AND
THUNDERSTORMS EXTEND BACK THROUGH CLEARFIELD COUNTY AND SHOULD
CONTINUE UNTIL AROUND 06Z.
ONCE THESE STORMS FADE THE NEXT QUESTION IS THE DEVELOPMENT OF
FOG/MIST OVER THE REGION. GIVEN THAT BFD...UNV AND SOON IPT WILL
HAVE RECEIVED RAINFALL...AND THAT LIGHT WINDS...CLEARING SKIES
WILL CONTINUE OVERNIGHT...PATCHY FOG/MIST SHOULD DEVELOP.
EXPECT MVFR TO BE POSSIBLE AT ALL BUT MDT AND LNS...WITH IFR
POSSIBLE AT UNV...IPT AND BFD. IFR IS MOST PROBABLE BETWEEN 09Z TO
14Z. EXPECT RESTRICTIONS TO IMPROVE BY 15Z.
TOMORROW WILL BRING ANOTHER DAY WITH POSSIBLE SHOWERS AND
THUNDERSTORMS...MAINLY ALONG THE SOUTHERN TIER OF PA
COUNTIES...THOUGH POSSIBLY AFFECTING JST...AOO...MDT AND LNS.
OUTLOOK...
MON...MAINLY VFR. SCT TSMS POSS SOUTH.
TUE...CIG RESTRICTIONS LIKELY NW HALF. CHANCE SHOWERS/TSTMS.
WED-FRI...MAINLY VFR. LOCAL A.M. FOG POSS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DEVOIR/RXR
NEAR TERM...DANGELO/DEVOIR/RXR
SHORT TERM...DEVOIR/MARTIN
LONG TERM...MARTIN
AVIATION...CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
932 PM EDT SUN JUL 19 2015
.SYNOPSIS...
A PAIR OF COLD FRONTS WILL PUSH SOUTHEAST ACROSS THE REGION
TONIGHT AND ON TUESDAY. HIGH PRESSURE WILL BUILD OVER PENNSYLVANIA
DURING THE SECOND HALF OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
930 PM...
HEAT ADVISORY FOR SE HAS ENDED.
ONGOING CLUSTER OF SEVERE WEATHER ALONG I-80 CORRIDOR THIS MID
EVENING LOOKS LIKE IT WILL GRADUALLY WEAKEN OVER NEXT FEW HOURS.
WW443 CONTINUES FOR THIS REGION...BUT HAS BEEN SCALED BACK ALONG
NORTHERN BORDER WHERE THREAT HAS ENDED.
BEGAN TO TAPER POPS BACK GRADUALLY LATE THIS EVENING AND ESP
OVERNIGHT...THOUGH THREAT FOR SHOWERS/POSS A TSTM WILL PERSIST
UNTIL COLD FROPA.
6 PM...
EARLY CONVECTION WHICH POPPED UP IN THE HEAT OVER THE CENTRAL
MOUNTAINS HAVE DISSIPATED. OTHER THAN A FEW SPECKLES
ELSEWHERE...THE ONLY GAME IN TOWN IS NOW THE STORMS OVER THE FAR
NW. LOTS OF STORMS SEEM TO SPLIT AND LEAVE THE LEFT-MOVER AS THE
STRONGER CELL. SO HAIL IS ALSO A THREAT WITH THE WIND DAMAGE STILL
THE MAIN THREAT. HAIL MAY END UP MELTING DOWN SOME EVEN IF IT WAS
LARGE ALOFT DUE TO HOT TEMPS AND DEEP WARM CLOUD DEPTH. TWEAKS
MAINLY FOR TIMING AND PLACEMENT.
PREV...
SEVERE THUNDERSTORM WATCH #443 IS NOW IN EFFECT FOR THE NORTHERN
HALF OF CENTRAL PA THROUGH 11 PM EDT. PRELIMINARY CELLS FIRING
DUE TO DIURNAL DESTABILIZATION AND BOUNDARY LAYER THERMAL RIDGE
PUSHING EAST OF MY AREA. HOTTEST DAY OF SUMMER THUS FAR IN
PROGRESS WITH APPARENT TEMPS SURGING INTO THE 90S THROUGHOUT.
HEAT INDICES WILL TOP OUT BETWEEN 100F AND 104F ACROSS THE SUSQ
VALLEY.
VERY WARM ALOFT WITH BOUNDARY LAYER CAPPING OF EARLIER TOWERS
NOW DECREASING AS CIN ANALYSIS SHOWS DESTABLIZATION OCCURRING
OVER LAKE ERIE AND NORTHWEST PA. JUST ONE HOUR AGO...ELEVATED
HEAT SOURCE SHOWERS BRIEFLY SPROUTED OVER SOUTH MOUNTAIN BEFORE
MOVING OFF THE TERRAIN AND QUICKLY DISSIPATING. SIMILAR SHOWERS
TRYING TO GROW OVER PORTIONS OF THE CENTRAL MOUNTAINS...AND ARE
NOW OVERCOMING THE CAP. HRRR DOES DEVELOP AND PROPOGATE THIS ISOLD
TO SCT SHRA/TSRA AREA SIMILAR TO SAT EVENING ACTIVITY BEFORE
DISSIPATING IT WITH THE DECREASE IN DIURNAL HEATING BY 00Z.
MAIN ACTIVITY EXPECTED WITH APPROACHING SHORTWAVE/COLD FRONT FROM
THE EASTERN GLAKS THIS EVENING THROUGH LATE TONIGHT. NO REAL
CHANGES TO PREVIOUS THINKING...WITH NORTHERN AREAS STANDING THE
GREATEST THREAT OF STRONG TO LOCALLY SEVERE STORMS...AS THE PARENT
SHORTWAVE WILL LIFT WELL NORTH OF THE REGION THIS EVENING. FAR
SOUTHEAST MAY BE HARD PRESSED TO RAIN FROM THIS FRONT AS A RESULT
LATE TONIGHT...AS GREATER DISTANCE FROM THE WANING LG SCALE
FORCING ACCOMPANIES FROPA FURTHER SOUTH. THUS TAPERING POPS TO THE
SOUTHEAST WILL BE MAINTAINED.
COOLER/DRIER AIR IN WAKE OF COLD FRONT SHOULD MAKE SOME INROADS
ACROSS THE NW MTNS...WHERE LOWS IN THE L60S EXPECTED TONIGHT. THE
REST OF CENTRAL PA WILL REMAIN IN MUGGY AIR MASS FOR ANOTHER NIGHT
WITH LOWS BTWN 70-75F SOUTH OF I-80.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
STALLED OUT COLD FRONT NR THE MASON DIXON LINE WILL BE THE FOCUS
FOR SCT PM CONVECTION ON MONDAY. ELSEWHERE...ARRIVAL OF LOW PWAT
AIR ACROSS NORTHERN PA SHOULD ENSURE A DRY DAY. ENS MEAN 8H TEMPS
ARE SUPPORTIVE OF HIGHS FROM THE L80S OVR THE N MTNS...TO THE L90S
ACROSS THE LOWER SUSQ VALLEY.
DID NOT CHANGE MUCH ON THIS PERIOD. DID GO WITH A DRY FCST FOR THE
MORNING HOURS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
HARD TO SEE A LOT GOING ON AFTER THIS EVENING...DUE TO THE LACK
OF SFC CONVERGENCE.
DID GO WITH SOME CHC POPS LATER MONDAY INTO TUE. HIGHEST CHC
ON TUE...AS SECONDARY FRONT DROPS SE.
AFTER THIS...LOOKING AT MAINLY DRY WEATHER WED INTO FRIDAY.
SOME MODELS LIKE THE GFS40 HAVE SOME SHOWERS IN THE SW ON THU.
LEFT FCST DRY FOR NOW.
MAIN CHANGE WAS TO LOWER TEMPS MORE FOR THE PERIOD WED INTO
FRIDAY. MAIN FACTORS ARE LOWER 500 MB HEIGHTS ON THE MODELS LATELY
ALSO THE TENDENCY FOR THE AIRMASS BEHIND COLD FRONTS TO BE COLDER
THAN FCST LATELY. ALSO THE WET GROUND.
MID SHIFT DID PUT SOME SHOWERS IN FOR THE FIRST PART OF THE
WEEKEND. SOME MODELS SHOW VERY STRONG WARM ADVECTION AND
DIRECTIONAL SHEAR INTO AT LEAST NW PA ON SUNDAY. EC NOT REALLY
SHOWING MUCH OF THIS. FOR NOW...DID CARRY SHOWERS INTO SUNDAY.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
VFR CONDS PREVAILING THROUGH MID AFTERNOON. ISOLATED RESTRICTIONS
BECOME POSSIBLE IN SCT TSTMS AFTER 20Z THIS AFTERNOON OVER
NORTHERN/CENTRAL MTNS. ACTIVITY WILL CONTINUE THROUGH THE
EVENING...UNTIL A COLD FRONT DROPS ACROSS CWA OVERNIGHT. STORMS
WILL BE MOST NUMEROUS /AND IMPACTS THE BIGGEST/ ACROSS NW HALF OF
CWA...AND SOME OF THESE TSTMS WILL BE STRONG TO SEVERE WITH SIG
LOCAL SHORT-LIVED IMPACTS TO CIGS/VSBYS AND STRONG WIND GUSTS.
OTHERWISE WINDS WILL BE FROM THE SW INCREASING TO AROUND 10 MPH.
OUTLOOK...
MON...CIG RESTRICTIONS POSS NW EARLY. OTHERWISE MAINLY VFR. SCT
TSMS POSS SOUTH.
TUE...CIG RESTRICTIONS LIKELY NW HALF. CHANCE SHOWERS/TSTMS.
WED-FRI...MAINLY VFR. LOCAL A.M. FOG POSS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DEVOIR/RXR
NEAR TERM...DANGELO/DEVOIR/RXR
SHORT TERM...DEVOIR/MARTIN
LONG TERM...MARTIN
AVIATION...DEVOIR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
308 AM EDT SAT JUL 18 2015
.SYNOPSIS...
AN UPPER LEVEL RIDGE WILL BUILD OVER THE NORTHEAST CONUS THIS
WEEKEND. A SHORT WAVE PASSING TO THE NORTH WILL PUSH A COLD FRONT
THROUGH PENNSYLVANIA ON MONDAY. HIGH PRESSURE IS LIKELY TO BUILD
SOUTHEAST INTO PENNSYLVANIA WEDNESDAY OR THURSDAY OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
HEAVY SHRA/TSRA FIRING OVR THE CENTRAL MTNS AT NOSE OF LL JET AS
OF 06Z. HIGH PWATS AND TRAINING CELLS POSE AT THREAT OF LOCALIZED
FLOODING ALONG THE I-80 CORRIDOR BTWN 06Z-09Z. HOWEVER...NEAR TERM
MDL DATA SUGGESTS LL JET AND ASSOC CONVECTION WILL WEAKEN AND PUSH
EAST OF THE CWA BY ARND DAWN. RADAR TRENDS AND LATEST HRRR SUPPORT
CAT TO LIKELY POPS ALONG THE I-80 CORRIDOR DURING THE PRE-DAWN
HOURS AND MUCH LOWER POPS OVER SOUTHERN PA AND THE N TIER.
TEMPS WON/T FALL MUCH FROM 06Z READINGS DUE TO HIGH HUMIDITY NOW
COVERING THE AREA. EXPECT MIN TEMPS ARND 70F ACROSS ALL OF CENTRAL
PA.
&&
.SHORT TERM /7 AM THIS MORNING THROUGH 6 PM SUNDAY/...
SHORTWAVE SHOULD HAVE PASSED EAST OF THE REGION BY DAWN...LEAVING
CENTRAL PA IN A REGION OF WEAK LG SCALE FORCING. EXPECT A DRY
MORNING OVR NEARLY THE ENTIRE AREA. HOWEVER...HEATING OF
MOIST/UNSTABLE AIR MASS SHOULD SPAWN SCT PM CONVECTION...WITH
GREATEST COVERAGE LIKELY ALONG AXIS OF HIGHEST PWATS OVER EASTERN
PA. ARRIVAL OF UPPER RIDGE AXIS AND ASSOC WARM TEMPS ALOFT SHOULD
LIMIT COVERAGE OF ANY STORMS ACROSS THE NW COUNTIES.
MODEL CAPES ABOUT AS HIGH AS WE SEE IN PA...BTWN 3000-5000 J/KG
SAT AFTN. HIGH CAPE AND WEAK SHEAR IMPLIES A LOW END THREAT OF
ISOLD PULSE TYPE SVR STORMS. SPC HAS ENTIRE AREA IN MGRL RISK.
BOUNDARY LAYER WARMING SUPPORTS WIDESPREAD HIGHS OF 85 TO 90. THIS
COMBINED WITH SFC DEWPOINTS IN THE LOWER 70S SHOULD CREATE HEAT
INDICES AS HIGH AS THE MID 90S IN THE SUSQ VALLEY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
THE RETURN TO MORE SUMMERLIKE WEATHER WILL CONTINUE ON
SUNDAY...AS 850HPA TEMPS RISE TO +2SD BY SUNDAY AFTN. AS TEMPS
CONTINUE TO WARM AND HUMIDITY CONTINUES TO CLIMB...HEAT INDICES
WILL APPROACH 100F /BORDERLINE HEAT ADVISORY CRITERIA/ IN THE
LOWER SUSQUEHANNA VALLEY SUNDAY AFTN.
A COLD FRONT WILL CROSS CENTRAL PA SUN NIGHT/EARLY
MONDAY...ACCOMPANIED BY A CHC FOR SHRA/TSRA. THE TIMING OF THE
FRONT EARLY IN THE DAY MAY BE A LIMITING FACTOR FOR SEVERE WX.
BEHIND THE FRONT...TEMPS WILL BE /SLIGHTLY/ COOLER AND THERE WILL
BE A RESPITE FROM THE MUGGINESS.
HIGH PRESSURE WILL ATTEMPT TO BUILD OVERHEAD LATE NEXT
WEEK...BEHIND ANOTHER WEAK COLD FRONT THAT IS FORECAST TO SETTLE
ACROSS CENTRAL PA NEXT WEDNESDAY.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
ACTIVE CLUSTER OF THUNDERSTORMS ACROSS CENTRAL AREAS OF THE REGION
TONIGHT. EARLIER...STORMS MOVED THROUGH KBFD AND KUNV. THE NEWLY
DEVELOPING STORMS WILL MAINLY BE SOUTH OF KBFD AND NORTH OF KAOO.
KUNV AND EVENTUALLY KIPT WILL AGAIN BE AFFECTED BY A ROUND OF
SHRA/TSRA.
INCREASED LOW LEVEL MOISTURE FROM THE CONVECTION...COUPLED WITH
LIGHT WINDS WILL LEAD TO OVERALL DEVELOPMENT OF LOWER CIGS ACROSS
MUCH OF THE REGION. EVEN THE LOWER SUSQUEHANNA VALLEY WITH AN
INFLUX OF LOW LEVEL MOISTURE HAS SEEN CIGS DROP INTO MVFR RANGE.
THIS WILL BE THE TREND OVERNIGHT...WITH WIDESPREAD MVFR TO IFR
CONDITIONS IN LOWER CLOUDS AND FOG. THERE MAY BE SOME LOCALLY
LOWER CONDITIONS IN ANY THUNDERSTORM ACTIVITY.
MOST IMPACTED HAS
BEEN KUNV...BUT BEFORE THE NIGHT IS OVER...KAOO AND KJST COULD
ALSO GET INTO THE SHRA/TSRA ACTION.
CONDITIONS DRY OUT FOR THE DAYTIME HOURS ON SATURDAY WITH VFR
CEILINGS AND VISIBILITIES RETURNING BY 13Z-15Z. AN ISOLATED
SHOWER OR THUNDERSTORM IS POSSIBLE AS DEWPOINTS REMAIN NEAR
70...HOWEVER NOT ENOUGH COVERAGE TO PLACE IN THE EXTENDED PORTION
OF THE FORECAST.
OUTLOOK...
SUN...SCT...MAINLY PM TSRA IMPACTS POSSIBLE.
MON...MORE NUMEROUS SHOWERS/TSRA LIKELY AS A COLD FRONT PUSHES
EAST ACROSS THE REGION.
TUE-WED...IMPROVING CONDS AS HIGH PRESSURE DOMINATING.
&&
.EQUIPMENT...
THE KBFD OBSERVATIONS ARE NOT AVAILABLE LONG-LINE DUE TO AN FAA COMMS
PROBLEM.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...DEVOIR/FITZGERALD
LONG TERM...EVANEGO
AVIATION...JUNG/TYBURSKI
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
845 PM CDT SUN JUL 19 2015
.DISCUSSION...
MINOR UPDATE MAINLY IN THE NORTHERN PORTION OF FORECAST AREA.
INCREASED POPS DUE TO STORMS IN MISSOURRI...WHICH THE HRRR BRINGS
INTO THE MID-SOUTH OVERNIGHT. NAM ALSO HINTS AT SOME PRECIPITATION
OVER AREA TONIGHT. HRRR IS MORE AGGRESSIVE AND MUCH MORE OF THE
AREA COVERED. HOWEVER...ONLY RAISED POPS SLIGHTLY AND THUS ONLY
NORTHERN PORTION HAVE HIGH ENOUGH POPS TO MENTION PRECIPITATION IN
THE FORECAST. HAVE TO WATCH THIS CLOSELY.
HEAT ADVISORY STILL CONTINUES FOR THROUGH TOMORROW. THIS IS
BEGINING TO LOOK LIKE A RARE EVENT FOR THE MID-SOUTH WITH
CONSECTUTIVE DAYS OF HEAT ADVISORIES...AT LEAST ACCORDING TO DATA
FOUND THIS EVENING AT OFFICE...SEE CLIMATE SECTION FOR MORE
DETAILS. TLSJR
&&
.PREV DISCUSSION... /ISSUED 306 PM CDT SUN JUL 19 2015/
DISCUSSION...WATER VAPOR SATELLITE TRENDS THIS AFTERNOON PLACE AN
UPPER LEVEL RIDGE OVER THE SOUTHERN PLAINS AND LOWER MISSISSIPPI
VALLEY. MOST AREAS HAVE REMAINED RAIN FREE EXCEPT FOR A PORTION OF
WEST TENNESSEE NEAR SAVANNAH AND EXTREME NORTHEAST MISSISSIPPI
WHERE ISOLATED SHOWERS AND THUNDERSTORMS DEVELOPED AND QUICKLY
PUSHED OUT OF THE FORECAST AREA. VISIBLE SATELLITE TRENDS INDICATE
MOSTLY SUNNY TO PARTLY SUNNY SKIES ACROSS THE MID SOUTH DUE TO THE
DEVELOPMENT OF DIURNAL BASED CUMULUS FROM LATE MORNING. AS OF 2 PM
CDT...TEMPERATURES ACROSS THE MID SOUTH ARE IN THE LOWER TO MIDDLE
90S AT MOST LOCATIONS. HEAT ADVISORY POTENTIAL THROUGH EARLY THIS
WEEK AND INCREASED CONVECTIVE POTENTIAL CHANCES ARE THE CHALLENGES
IN THIS AFTERNOON/S FORECAST ISSUANCE.
AFTERNOON TEMPERATURES IN THE LOWER TO MIDDLE 90S COMBINED WITH
SURFACE DEWPOINTS IN THE LOWER TO MIDDLE 70S HAS RESULTED IN HEAT
INDEX READINGS REACHING OR EXCEEDING 105 DEGREES THIS AFTERNOON.
SOME CLOUD COVER HAS TEMPORARILY DROPPED HEAT INDEX READINGS BELOW
ADVISORY CRITERIA ACROSS PORTIONS OF THE MID SOUTH...BUT POTENTIAL
EXISTS FOR THESE AREAS TO SEE VALUES AT OR ABOVE 105 DEGREES AGAIN
BEFORE SUNSET.
MODELS CONTINUE TO INDICATE AN UPPER LEVEL RIDGE AXIS HOLDING IN
PLACE ACROSS MUCH OF THE MID SOUTH THIS EVENING BUT WILL WEAKEN
ACROSS AREAS NEAR THE KENTUCKY/MISSOURI BORDER LATE TONIGHT AND
NORTH OF I-40 ON MONDAY. SHEAR WILL CONTINUE TO REMAIN WEAK
OVERALL AND THINK ANY CONVECTIVE ACTIVITY WILL BE TRIGGERED BY
CONVECTIVE TEMPERATURES BEING REACHED...RESULTING IN THE
DEVELOPMENT OF RATHER DISORGANIZED PULSE TYPE THUNDERSTORMS.
TEMPERATURES AGAIN WILL BE HOT ON MONDAY AND HIGH SURFACE
DEWPOINTS IN THE LOWER TO PERHAPS MIDDLE 70S WILL RESULT IN HEAT
INDEX READINGS ONCE AGAIN REACHING OR EXCEEDING 105 DEGREES. THE
HEAT ADVISORY WILL REMAIN IN EFFECT FOR THE ENTIRE MID SOUTH
THROUGH AT LEAST 7 PM CDT MONDAY.
BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS WILL ARRIVE FOR
TUESDAY AS A WEAK COLD FRONT DROPS INTO THE LOWER MISSISSIPPI
VALLEY. HEAT INDEX READINGS MAY ONCE AGAIN APPROACH/EXCEED 105
DEGREES AND THE CURRENT HEAT ADVISORY MAY ONCE AGAIN NEED TO BE
EXTENDED IN TIME. WILL HOLD OFF FOR THE TIME BEING TO UNCERTAINTY
RELATED TO CONVECTIVE COVERAGE AND ITS AFFECT ON TEMPERATURES.
BEST CHANCES FOR SHOWERS AND THUNDERSTORMS WILL PERSIST THROUGH
THURSDAY. LONG TERM MODELS INDICATE THE UPPER LEVEL RIDGE AXIS
WILL TRY TO BUILD BACK IN ACROSS THE LOWER MISSISSIPPI VALLEY WITH
THE BEST CHANCES FOR SHOWERS AND THUNDERSTORMS BEING SLIGHTLY EAST
OF THE MID SOUTH TOWARDS NEXT WEEKEND.
CJC
&&
.AVIATION...
00Z TAFS
VFR TO CONTINUE THROUGH THE NEXT 24 HOURS. NAM CU RULE CHART SHOWS
BEST CUMULUS COVERAGE MONDAY AFTERNOON NEAR MKL...WITH JBR AND MEM
POSSIBLY CLEAR.
PWB
&&
.CLIMATE...
LOOKING AT DATA FROM 2004 TO TODAY WHEN THE MEMPHIS OFFICE ISSUED
EITHER A HEAT ADVISORY OR EXCESSIVE HEAT WARNING. THE FOLLOWING
TABLES SHOW THE TOP SIX NUMBER OF DAYS IN A ROW A ADVISORY OR
WARNING WERE ISSUED. WE DON/T HAVE RECORDS OF HEAT INDEX VALUES
FOR ALL DAYS ACROSS THE MID-SOUTH SO USED THE ADVISORIES AND
WARNINGS.
FOR ALL THE MID-SOUTH (THAT IS ANYWHERE IN THE MID-SOUTH)
19 DAYS - JULY 29 - AUGUST 16, 2010
13 DAYS - JULY 26 - AUGUST 8, 2011
11 DAYS - JULY 16 - JULY 26, 2010
11 DAYS - JULY 26 - AUGUST 5, 2008
9 DAYS - JULY 18 - JULY 26, 2012
8 DAYS - JULY 12 - JULY 19, 2015 /TODAY/
8 DAYS - JULY 28 - AUGUST 5, 2012
8 DAYS - JUNE 18 - JUNE 25, 2010
8 DAYS - JULY 20 - JULY 27, 2005
WE SHOULD REACH THE TOP FIVE FOR THE AREA ON MONDAY.
LOOKING SPECIFICALLY AT MEMPHIS /SHELBY COUNTY/ IT IS ALREADY IN
THE TOP 5 FOR THE PAST 11 YEARS.
FOR SHELBY COUNTY
11 DAYS - JULY 26 - AUGUST 5, 2008
10 DAYS - JULY 30 - AUGUST 8, 2011
10 DAYS - AUGUST 7 - AUGUST 16, 2010
9 DAYS - JULY 18 - JULY 26, 2012
8 DAYS - JULY 12 - JULY 19, 2015 /TODAY/
8 DAYS - JULY 29 - AUGUST 5, 2010
8 DAYS - JUNE 18 - JUNE 25, 2010
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...HEAT ADVISORY UNTIL 7 PM CDT MONDAY FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI-
PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...HEAT ADVISORY UNTIL 7 PM CDT MONDAY FOR DUNKLIN-PEMISCOT.
MS...HEAT ADVISORY UNTIL 7 PM CDT MONDAY FOR ALCORN-BENTON MS-CALHOUN-
CHICKASAW-COAHOMA-DESOTO-ITAWAMBA-LAFAYETTE-LEE MS-MARSHALL-
MONROE-PANOLA-PONTOTOC-PRENTISS-QUITMAN-TALLAHATCHIE-TATE-
TIPPAH-TISHOMINGO-TUNICA-UNION-YALOBUSHA.
TN...HEAT ADVISORY UNTIL 7 PM CDT MONDAY FOR BENTON TN-CARROLL-
CHESTER-CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-
HARDIN-HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-
MCNAIRY-OBION-SHELBY-TIPTON-WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1103 AM CDT SAT JUL 18 2015
.UPDATE...
MORNING FORECAST UPDATE.
&&
.DISCUSSION...
OVERALL NOT A LOT OF CHANGE IN THE FORECAST. PRECIP WATER VALUES
RANGE FROM 1.7 TO 2.0 INCHES BASED ON SOUNDINGS AND GOES SATELLITE
DERIVED DATA. STILL A STRONG ENOUGH RIDGE ALOFT TO LIMIT ACTIVITY
MORE SO THAN YESTERDAY. STILL A SMALL CHANCE FOR A PASSING SHOWER
BUT EXPECT MOST AREAS TO STAY DRY. KEEP RAIN CHANCES AROUND 20
PERCENT BUT MENTION ISO COVERAGE. ONLY OTHER CONCERN WILL BE HEAT
INDEX VALUES. GIVEN ENOUGH DEEP MOISTURE...DO NOT THINK MIXING
WILL BE QUITE ENOUGH TO LOWER DEWPOINTS. TEMPS MAY BE A TAD LOWER
BUT STILL ENOUGH FOR HIGH HEAT INDEX VALUES NEAR 105. AT 16Z MOST
AREAS HAD HEAT INDEX VALUES AROUND 95 TO 103F. OTHERWISE FORECAST
LOOKS ON TRACK.
39
&&
.PREV DISCUSSION... /ISSUED 650 AM CDT SAT JUL 18 2015/
AVIATION...
A REPEAT MVFR DECK ADVANCING IN FROM CENTRAL TEXAS MAY CLIP AND
AFFECT KCLL FOR A COUPLE OF HOURS THIS MORNING. GENERALLY AREAWIDE
VFR THROUGHOUT THE PERIOD. HIGHER MOISTURE WITHIN AN AIR MASS THAT
WILL HEAT UP INTO THE MID 90S WILL LIKELY PRODUCE WIDELY SCATTERED
SHOWERS AND AN ISOLATED THUNDERSTORM. ANY CONVECTIVE ACTIVITY WILL
OCCUR FROM MID MORNING CLOSER TO THE COAST THROUGH THE LATE AFTERNOON
HOURS FURTHER INLAND. MAJORITY OF THE DAY WILL EXPERIENCE FAIR WEATHER
CUMULUS WITH 5-15 KT SOUTHWEST-VEERING-SOUTHERLY NEAR SURFACE WINDS.
31
PREV DISCUSSION... /ISSUED 303 AM CDT SAT JUL 18 2015/
DISCUSSION...
LINGERING MOISTURE LEVELS AND A SLIGHT WEAKNESS ALOFT MIGHT BE ENOUGH
TO GENERATE SOME SHOWERS AND POSSIBLE THUNDERSTORMS AGAIN TODAY...BUT
DO THINK COVERAGE WILL BE LESS THAN WHAT PARTS OF THE AREA SAW ON FRIDAY.
SPC`S LATEST DAY 1 CONVECTIVE OUTLOOK HAS PARTS OF OUR AREA IN GENERAL
THUNDER ONCE AGAIN...AND THE HRRR RUNS COMING IN SO FAR EARLY THIS MORNING
DO SHOW SOME ACTIVITY DEVELOPING DURING THE DAY. SO WILL CARRY 20% POPS
FOR THE COUNTIES GENERALLY ALONG AND SOUTH OF THE HIGHWAY 59 CORRIDOR.
WILL GO BACK TO A DRY FORECAST BEGINNING THIS EVENING AND CONTINUING
ON FOR THE REST OF THE WEEKEND AND THROUGHOUT THE UPCOMING WEEK AS
IT LOOKS LIKE MID/UPPER LEVEL RIDGING WILL BE STRONG ENOUGH TO KEEP
THE MAJORITY OF OUR AREA VERY WARM AND DRY. EVEN THOUGH WE WILL CONTINUE
TO SEE HEAT INDEX VALUES ACROSS A MAJORITY OF OUR AREA UNDER HEAT ADVISORY
LEVELS...US AND OUR PARTNERS WILL NEED TO CONTINUE TO GET THE WORD OUT
ON HEAT SAFETY.
FOR JULY 1-17...GALVESTON`S AVERAGE TEMPERATURE HAS BEEN 85.7 DEGREES.
IF THIS VALUE HOLDS FOR THE REST OF THE MONTH...JULY 2015 WOULD GO
DOWN AS THE 8TH WARMEST JULY ON RECORD. IN ADDITION...THEIR RAINFALL
TOTAL FOR THE MONTH OF 0.23 INCHES WOULD GO DOWN AS THE 7TH DRIEST
JULY ON RECORD. 42
MARINE...
HIGH PRESSURE CONTINUES TO RESIDE OVER THE GULF THE NEXT SEVERAL
DAYS AFFORDING A LIGHT SOUTHWEST TO SOUTHEAST WIND...PERIODS OF
WEEKEND SCATTERED SHOWERS. A SLIGHTLY TIGHTER LAND AND SEA THERMAL
GRADIENT WILL STRENGTHEN WINDS A BIT DURING THE OVERNIGHT HOURS.
SEAS WILL GENERALLY REMAIN AT OR UNDER THREE FEET...WITH AVERAGE
FOUR HEIGHTS WHERE THIS MORE MODERATE LATE EVENING INTO EARLY
MORNING ONSHORE FETCH EXISTS. 31
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 97 76 97 76 98 / 10 0 0 0 10
HOUSTON (IAH) 96 77 97 76 97 / 20 0 10 0 10
GALVESTON (GLS) 91 82 91 81 92 / 20 10 10 0 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...39
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
303 AM CDT SAT JUL 18 2015
.DISCUSSION...
LINGERING MOISTURE LEVELS AND A SLIGHT WEAKNESS ALOFT MIGHT BE ENOUGH
TO GENERATE SOME SHOWERS AND POSSIBLE THUNDERSTORMS AGAIN TODAY...BUT
DO THINK COVERAGE WILL BE LESS THAN WHAT PARTS OF THE AREA SAW ON FRIDAY.
SPC`S LATEST DAY 1 CONVECTIVE OUTLOOK HAS PARTS OF OUR AREA IN GENERAL
THUNDER ONCE AGAIN...AND THE HRRR RUNS COMING IN SO FAR EARLY THIS MORNING
DO SHOW SOME ACTIVITY DEVELOPING DURING THE DAY. SO WILL CARRY 20% POPS
FOR THE COUNTIES GENERALLY ALONG AND SOUTH OF THE HIGHWAY 59 CORRIDOR.
WILL GO BACK TO A DRY FORECAST BEGINNING THIS EVENING AND CONTINUING
ON FOR THE REST OF THE WEEKEND AND THROUGHOUT THE UPCOMING WEEK AS
IT LOOKS LIKE MID/UPPER LEVEL RIDGING WILL BE STRONG ENOUGH TO KEEP
THE MAJORITY OF OUR AREA VERY WARM AND DRY. EVEN THOUGH WE WILL CONTINUE
TO SEE HEAT INDEX VALUES ACROSS A MAJORITY OF OUR AREA UNDER HEAT ADVISORY
LEVELS...US AND OUR PARTNERS WILL NEED TO CONTINUE TO GET THE WORD OUT
ON HEAT SAFETY.
FOR JULY 1-17...GALVESTON`S AVERAGE TEMPERATURE HAS BEEN 85.7 DEGREES.
IF THIS VALUE HOLDS FOR THE REST OF THE MONTH...JULY 2015 WOULD GO
DOWN AS THE 8TH WARMEST JULY ON RECORD. IN ADDITION...THEIR RAINFALL
TOTAL FOR THE MONTH OF 0.23 INCHES WOULD GO DOWN AS THE 7TH DRIEST
JULY ON RECORD. 42
&&
.MARINE...
HIGH PRESSURE CONTINUES TO RESIDE OVER THE GULF THE NEXT SEVERAL
DAYS AFFORDING A LIGHT SOUTHWEST TO SOUTHEAST WIND...PERIODS OF
WEEKEND SCATTERED SHOWERS. A SLIGHTLY TIGHTER LAND AND SEA THERMAL
GRADIENT WILL STRENGTHEN WINDS A BIT DURING THE OVERNIGHT HOURS.
SEAS WILL GENERALLY REMAIN AT OR UNDER THREE FEET...WITH AVERAGE
FOUR HEIGHTS WHERE THIS MORE MODERATE LATE EVENING INTO EARLY
MORNING ONSHORE FETCH EXISTS. 31
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 97 76 97 76 98 / 10 0 0 0 10
HOUSTON (IAH) 96 77 97 76 97 / 20 0 10 0 10
GALVESTON (GLS) 91 82 91 81 92 / 20 10 10 0 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...42
AVIATION/MARINE...31
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
747 PM EDT SUN JUL 19 2015
.SYNOPSIS...
A SERIES UPPER LEVEL DISTURBANCES WILL KEEP SHOWERS AND STORMS IN
THE FORECAST THROUGH AT LEAST TUESDAY...WHEN AN ASSOCIATED COLD
FRONT WILL MOVE INTO AND THROUGH THE REGION. DRIER....COOLER...AND
LESS HUMID HIGH PRESSURE WILL BUILD INTO THE REGION FOR WEDNESDAY
AND THURSDAY. THE CENTER OF THE HIGH WILL SLOWLY MOVE EASTWARD
HEADING INTO THE WEEKEND...THIS WILL ALLOW FOR INCREASING
MOISTURE...PRECIPITATION CHANCES...AND WARMER CONDITIONS ACROSS THE
AREA.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 550 PM EDT SUNDAY...
QUICK UPDATE TO THE FORECAST TO REFLECT RADAR/MESO TRENDS.
ISOLATED CONVECTION MOVING OVER THE MTNS AND PIEDMONT THIS
AFTERNOON...WITH BETTER ORGANIZED LINE UPSTREAM OVER THE WV/OH/NE
KY BORDER...TRACKING SE. 20Z HRRR HAS THIS RADAR TREND PICKED UP A
BIT BUT THEN WEAKENS THIS LINE AS IT MOVES TWD OUR SE WV COUNTIES
BY 00Z. THE 21 RAP KEEPS TIMING SLOWER THAN MOVEMENT ON RADAR AND
SHOWING BEST LIFT TRACKING OVR SRN OHIO. THINK ENOUGH INSTABILITY
IN PLACE PLUS SOME MOISTURE CONVERGENCE TO KEEP CHANCE POPS IN THE
SE WV AND FAR SW VA AFTER 00Z...PER CURRENT FORECAST. THE REST OF
THE AREA WILL BE ISOLATED...WITH A FEW AREAS WHERE ITS MORE
SCATTERED THINKING MORE ACROSS SOUTHSIDE VA INTO NC...WHERE
MLCAPES ARE 3000 J/KG AT 21Z. THE AREA BETWEEN THE PIEDMONT AND
I-81 CORRIDOR IS LESS UNSTABLE AND DEALING WITH A LITTLE MORE
DOWNSLOPE PER NW FLOW ALOFT. TEMPS WILL STAY VERY WARM/HOT TIL
SUNSET EXCEPT COOLER WHERE IT RAINS. DEWPOINTS RUNNING HIGHER IN
THE SOUTH SO BUMPED THOSE UP THROUGH EARLY EVENING.
PREVIOUS DISCUSSION AT 230 PM...
ISOLATED TO SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL
CONTINUE ACROSS PARTS OF THE AREA THROUGH THE EARLY EVENING. THE
GREATEST CONCENTRATION WILL BE THOSE PARTS OF THE AREA CURRENTLY
EXPERIENCING THIS ACTIVITY....ACROSS THE WEST AND SOUTHWEST...AND
THE SOUTH AND SOUTHEAST AND EASTERN PARTS OF THE REGION. THE AREA
FROM ROUGHLY ROANOKE NORTH TO LEWISBURG AND EAST TO LEXINGTON IS
EXPECTED TO EXPERIENCE THE LEAST COVERAGE. THE ACTIVITY WILL WANE
DURING THE EVENING HOURS AFTER SUNSET.
OVERNIGHT...GUIDANCE CONTINUES TO OFFER A SOLUTION THAT BRINGS
ANOTHER THUNDERSTORM COMPLEX SOUTHEAST INTO THE REGION DURING THE
EARLY MORNING HOURS OF MONDAY. THIS SOLUTION IS REFLECTED IN OUR
CURRENT FORECAST...AND OUR UPCOMING FORECAST WILL CONTINUE TO AS
WELL. AS THE SYSTEM HEADS SOUTHEAST THROUGH THE AREA MONDAY
MORNING...IT COULD PAN OUT SIMILARLY TO WHAT HAPPENED ON SATURDAY.
THE SYSTEM ENTERED OUR REGION...DISSIPATED...AND LEFT A RESIDUAL
STABLE AREA OF DEBRIS CLOUD COVER OVER THE REGION. CONVECTION DID
NOT RE-ESTABLISH ITSELF UNTIL LATER IN THE AFTERNOON...AND THEN ON
THE FORWARD FLANK OF THE DIFFERENTIAL HEATING ZONE OF THE DISSIPATED
SYSTEM. WHILE HIS POTENTIAL EXISTS...A DIFFERENCE FROM SATURDAY WILL
BE A REINFORCING FRONTAL BOUNDARY MOVING TOWARD THE REGION DURING
THE AFTERNOON. WHILE THERE MAY BE A PERIOD OF STABILITY IMMEDIATELY
IN THE WAKE OF THE THUNDERSTORM COMPLEX...THE APPROACH OF THE FRONT
IS EXPECTED TO REFIRE ACTIVITY...ESPECIALLY IN THE WEST...MONDAY
AFTERNOON.
TEMPERATURES WILL CONTINUE TO BE ON THE WARM/HOT AND HUMID SIDE.
LOWS TONIGHT ARE EXPECTED TO BE IN THE UPPER 60S TO AROUND 70 IN THE
MOUNTAINS WITH THE LOWER 70S ACROSS THE PIEDMONT. HIGHS ON MONDAY
WILL RANGE FROM THE MID TO UPPER 80S ACROSS THE MOUNTAINS TO THE LOW
TO MID 90S ACROSS THE PIEDMONT. HEAT INDEX VALUES ARE EXPECTED TO
AGAIN TOP 100 DEGREES...MAINLY IN AREAS ALONG AND EAST OF A
YADKINVILLE NC...MARTINSVILLE VA...LYNCHBURG VA LINE. READINGS ARE
EXPECTED TO REMAIN BELOW THE HEAT ADVISORY CRITERIA OF 105+ DEGREES
FOR A LEAST A THREE HOUR WINDOW.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 340 PM EDT SUNDAY...
THE PRIMARY SYNOPTIC FEATURE THROUGH THE PERIOD WILL BE A
DEEPENING AND BROADENING UPPER TROUGH ACROSS THE GREAT LAKES AND
EASTERN CANADIAN PROVINCES...DRIFTING TOWARD THE CANADIAN
MARITIMES BY THE END OF THE WEEK. AS HAS BEEN THE CASE
RECENTLY...A SERIES OF DISTURBANCES WILL RIDE ESE-SE WITHIN THE
BASE OF THE UPPER TROUGH...TRACKING ACROSS OUR REGION AND
IMPINGING ON A MOIST/UNSTABLE AIR MASS. BY WEDNESDAY...THE TROUGH
WILL FINALLY DEEPEN ENOUGH TO PUSH A COLD FRONT/WEAK BOUNDARY
SOUTH OF THE AREA...WHICH WILL AT LEAST BRIEFLY GIVE MUCH OF THE
CWA A RESPITE FROM THE RECENT HIGH DEWPOINTS/RELATIVE HUMIDITY
AND VERY WARM TEMPERATURES.
THE KEY TO THIS FORECAST PERIOD WILL BE TIMING OF UPPER-LEVEL
SHORT WAVES/DISTURBANCES AND ASSOCIATED CONVECTION. ONE SUCH SHORT
WAVE SHOULD BE DRIFTING EAST OF THE AREA MONDAY EVENING/MONDAY
NIGHT...BUT ANOTHER STRONGER...MORE ORGANIZED
DISTURBANCE...AND WHAT APPEARS TO BE THE MAIN DISTURBANCE TIED TO
PUSHING THE FRONT AND DRIER AIR FURTHER SOUTH...WILL BE LOCATED
ACROSS THE MIDWEST/WESTERN GREAT LAKES. ONCE AGAIN IT APPEARS THAT
AN ASSOCIATED MCS WITH THIS LATER DISTURBANCE WILL DRIFT INTO THE
CWA EARLY TUESDAY MORNING. THIS SHOULD LEAVE THE WESTERN AREAS
WITH CONSIDERABLE CLOUD COVER/LIGHT SHOWERS/ISOLATED THUNDERSTORMS
IN THE MORNING...THEN POSSIBLE REDEVELOPMENT EAST OF THE BLUE
RIDGE BY AFTERNOON. CONFIDENCE IN THE LATER POSSIBILITY IS LOW AT
THIS POINT AS TIMING IS EVERYTHING WITH THIS TYPE OF CONVECTIVE
DEVELOPMENT.
BY TUESDAY EVENING/NIGHT...THE FRONT BECOMES MORE WEST-EAST
ORIENTED JUST TO OUR SOUTH. CONFIDENCE IN THE FRONT ACTUALLY
PUSHING COMPLETELY SOUTH OF THE CWA AND TAKING ALL OF THE
ASSOCIATED CONVECTION WITH IT IS LOW AT THIS POINT. YET ANOTHER
UPPER-LEVEL DISTURBANCE IS EVIDENT UPSTREAM ACROSS OK/KS/MO
AREA...WHICH LIKELY WILL BUCKLE THE FRONT BACK TO THE NORTH IN THE
WESTERN AREAS. THIS SCENARIO SHOULD RESULT IN A RESURGENCE OF
CONVECTION BACK INTO THE SOUTHWEST PART OF THE CWA WED
AFTERNOON/EVENING...BUT THE NORTHEASTERN TWO-THIRDS OF THE CWA
SHOULD BE DRY. ALL-IN-ALL...THE PERIOD FEATURES CHANCE TO
OCCASIONALLY LIKELY POPS ACROSS THE MOUNTAINS...WITH MONDAY
NIGHT/TUESDAY APPEARING TO BE THE MOST THE LIKELY PERIOD FOR
RAINFALL OVERALL. THE SEVERE WEATHER THREAT APPEARS LOW...BUT
DEPENDING ON TIMING...AN ISOLATED STRONG TO SEVERE STORM COULD NOT
BE RULED OUT TUESDAY AFTERNOON/EVENING.
TEMPERATURES WILL REMAIN ABOVE NORMAL THROUGH THIS
PERIOD...ESPECIALLY MIN TEMPS. MAX TEMPS WILL ALSO REMAIN WELL
ABOVE NORMAL TUESDAY IN THE EAST...BUT SHOULD BE A TAD COOLER IN
THE WEST GIVEN GREATER CLOUD COVER. TEMPERATURES SHOULD TREND DOWN
A COUPLE OF DEGREES WEDNESDAY...BUT IT APPEARS WE WILL HAVE TO
WAIT UNTIL THU MORNING FOR ANY REAL DRYING OF THE AIR MASS AND
LOWERING OF THE DEWPOINTS.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 350 PM EDT SUNDAY...
BROAD TROUGHING ACROSS THE NORTHEAST U.S. WILL DOMINATE THE
WEATHER AT THE BEGINNING OF THE PERIOD. THE FRONTAL
BOUNDARY/BAROCLINIC ZONE SHOULD BE LOCATED FROM THE MIDWEST INTO
THE SOUTHEAST STATES...HOPEFULLY SAFELY ENOUGH SOUTH OF OUR AREA
TO INHIBIT CONVECTION OF MUCH EXTENT. HOWEVER...WILL NEED TO WATCH
THU AS THERE IS YET ANOTHER UPSTREAM WAVE RIDING ALONG THE
BAROCLINIC ZONE THAT COULD BUCKLE THE BOUNDARY BACK FAR ENOUGH
NORTH TO ALLOW CONVECTION TO DRIFT BACK INTO THE SOUTHWEST PART OF
THE CWA...ESPECIALLY THE NW NC MOUNTAINS. THERE IS BETTER
PROBABILITY/CONFIDENCE THAT ONCE THIS FEATURE PASSES BY TO THE
SOUTH FRIDAY...WE WILL SEE GREATER POTENTIAL FOR THE FRONTAL
BOUNDARY TO DRIFT FURTHER SOUTH AND TAKE THE CONVECTION WITH IT. A
WEAK UPPER LOW CUTS OFF ACROSS THE SOUTHEAST STATES BY THE
WEEKEND AND STALLS. BY SAT-SUN...THE UPPER RIDGE AMPLIFIES ACROSS
THE CENTRAL U.S. AND WE QUICKLY RETURN BACK TO A MORE UNSTABLE
NORTHWEST FLOW AND THE POTENTIAL FOR UPSTREAM CONVECTIVE COMPLEXES
TO REACH THE REGION.
850MB TEMPS DROP BELOW +20C THU-SAT...CREEPING BACK ABOVE +20C
ACROSS MUCH OF THE CWA BY THE END OF NEXT WEEKEND. DEWPOINTS DROP
INTO THE 50S ACROSS THE NORTHERN PART OF THE CWA BY THU
MORNING...WHICH SHOULD BE QUITE REFRESHING...BEFORE THEY CREEP
BACK UP INTO THE 60S TO LOW 70S BY THE WEEKEND. NEAR TO SLIGHTLY
BELOW NORMAL TEMPS THU-FRI...SHOULD RETURN TO ABOVE NORMAL LEVELS
BY THE WEEKEND.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 735 PM EDT SUNDAY...
TRYING TO ZERO IN ON CONVECTION IS PROBLEMATIC IN TERMS OF TAFS.
CONVECTION STARTING TO WANE OVER WV BUT THINK IT MAY VERY WELL GET
CLOSE ENOUGH TO BLF FOR VCTS TIL 02Z. FURTHER UPSTREAM A MORE
PRONOUNCED SHORTWAVE EXISTS AND WILL WEAKEN AS IT MOVES INTO THE
MTNS AFTER MIDNIGHT...BUT WILL SEE SHOWERS ACROSS THIS AREA IN A
SCATTERED FASHION. NOT RULING OUT THUNDER BUT THINK INSTABILITY
WILL BE LIMITED. KEPT VCSH AT BLF/LWB OVERNIGHT.
IN THE MEANTIME...WILL SEE A MIX OF MID AND HIGH CLOUDS INTO THIS
EVENING IN THE WEST WITH MORE CLEARING IN THE EAST. MOISTURE IN
THE SFC-900 MB WILL STAY HIGH SO ANY CLEARING MAY ALLOW FOR SOME
FOG WORKING IN AT ALL SITES BUT ROANOKE. NOT TOO CONFIDENT ON
LOWER CIGS ALTHOUGH BLF COULD DROP TO MVFR WITH SHOWERS
APPROACHING IN THE OVERNIGHT TIME FRAME.
FOR MONDAY...APPEARS ATTM WILL SEE MAINLY SHOWERS AND STORMS
FIRING IN THE AFTERNOON AS UPPER ENERGY IS WEAK WITH BEST
SHORTWAVE IN THE MIDWEST. KEPT HIGHER POPS IN THE WEST SO WILL
HAVE VCTS FROM ROA WEST TOMORROW AFTERNOON UNDER VFR CIGS.
EXTENDED AVIATION DISCUSSION...
MONDAY NIGHT...WILL AWAIT AN DECAYING CONVECTIVE CLUSTER MOVING
OUT OF THE OHIO VALLEY INTO OUR AREA LATE. MAY SEE SOME
FOG/STRATUS BEFORE THIS OCCURS BUT CONDITIONS FAVOR LESS OF
THIS...GIVEN MORE DEBRIS CLOUDS.
TUESDAY WILL SEE A BETTER INCREASE IN STORM SINCE A FRONTAL
BOUNDARY WILL SINK SWD IN RESPONSE TO STRONGER TROUGH OVER THE
GREAT LAKES/NE. THIS FRONT SINKS SOUTH BY WEDNESDAY AND THURSDAY
AND BUCKLES NWD AGAIN FRIDAY. SO FOR NOW WILL EXPECT OVERALL VFR
CONDITIONS OUTSIDE CONVECTION TUESDAY...THEN FOG/STRATUS POSSIBLE
WED/THU MORNING IN THE BCB/LWB AREA PENDING HOW DRY THE AIR GETS
BEHIND THIS FRONT. THEN MORE SHOWERS AND STORMS POSSIBLE NEXT
FRIDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS
NEAR TERM...DS/WP
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
209 PM EDT SAT JUL 18 2015
.SYNOPSIS...
A WEAK TROUGH OF LOW PRESSURE WILL CROSS THE MOUNTAINS FROM THE
WEST THIS MORNING BEFORE EXITING THE PIEDMONT LATER THIS AFTERNOON.
ANOTHER WEAK FRONT WILL DRIFT INTO THE REGION FROM THE NORTHWEST
BY MONDAY...STALLING NEAR US AS WEAK WAVES OF LOW PRESSURE RIDE
ALONG THE BOUNDARY THROUGH THE FIRST HALF OF NEXT WEEK. THIS WILL
CONTINUE TO RESULT IN WARM AND HUMID CONDITIONS THROUGH THE PERIOD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM EDT SATURDAY...
CONVECTION IS STARTING TO TAKE PLACE JUST SOUTH OF THE
FORECAST AREA AND ALSO ACROSS THE FAR SOUTHEAST PART OF THE
FORECAST AREA. THIS REGION HAS BEEN OUTSIDE THE REGION OF
RESIDUAL CLOUD COVER FROM THE CONVECTION EARLY THIS MORNING. THAT
SAME CLOUD COVER HAS BEEN ERODING...AND IN ITS WAKE...AT LEAST
SOME CUMULUS CLOUDS HAVE BEEN FORMING ACROSS PARTS OF SOUTHWEST
VIRGINIA. ANTICIPATING ADDITIONAL DEVELOPMENT THIS AFTERNOON ACROSS
THE FORECAST AREA AS SURFACE HEATING CONTINUES. THE FOCUS FOR THE
BEST COVERAGE IS ACROSS THE PIEDMONT REGION WHERE THE LATEST SPC
DAY ONE CONVECTIVE OUTLOOK STILL PLACES A MARGINAL RISK IN THIS
AREA. HAVE TWEAKED HOURLY TEMPERATURE...DEW POINT AND SKY COVER
BASED UPON THE LATEST OBSERVATIONS AND EXPECTED TRENDS THROUGH THE
MID-AFTERNOON.
AS OF 945 AM EDT SATURDAY...
LITTLE REMAINS OF THE EARLIER DYING MCS THAT ENTERED THE REGION
EARLIER THIS MORNING. AT BEST...ISOLATED TO PATCHY LIGHT RAIN
SHOWERS WERE STILL NEAR AND NORTHEAST OF ROANOKE VIRGINIA ALONG
THE INTERSTATE-81 CORRIDOR. PLENTY OF RESIDUAL CLOUD COVER
CONTINUES TO EXIST ACROSS THE CENTRAL PORTION OF THE FORECAST
AREA...AND IS SLOW DRIFTING EASTWARD. THE FAR WESTERN AND
SOUTHEASTERN PARTS OF THE AREA ARE RECEIVING MOSTLY SUNNY TO SUNNY
CONDITIONS. IT WILL BE THESE TWO LOCATIONS THAT WILL HAVE THE BEST
OPPORTUNITY OF SHOWER AND THUNDERSTORM DEVELOPMENT HEADING INTO
THE AFTERNOON HOURS. WHILE THE CENTRAL PORTION OF THE AREA WILL
EVENTUALLY HAVE SOME SUNSHINE...IT WILL BE LATER IN THE DAY...AND
THIS REGION WILL BE SLOWER TO EXPERIENCE SURFACE BASED CONVECTION
DEVELOP. THAT IS NOT TO SAY THAT ACTIVITY THAT FORMS IN THE WEST
MAY NOT MOVE INTO CENTRAL PORTIONS LATER THIS AFTERNOON. THE
LATEST FORECAST UPDATE WILL REFLECT NO MAJOR CHANGES IN THE BIG
PICTURE TODAY. HOWEVER...IN THE NEAR TERM...A GREATER DISTINCTION
HAS BEEN MADE WHERE NO PRECIPITATION IS EXPECTED OVER THE NEXT FEW
HOURS VERSUS WHERE SCATTERED ACTIVITY IS EXPECTED. LIKEWISE...A
SIMILAR DISTINCTION HAS BEEN MADE TO CLOUDY VERSUS MOSTLY SUNNY TO
SUNNY AREAS.
AS OF 227 AM EDT SATURDAY...
MAIN CONCERN INITIALLY WITH RESIDUAL MCS CURRENTLY APPROACHING THE WESTERN
SLOPES AND JUST HOW FAR EAST THIS COMPLEX WILL GET THIS MORNING BEFORE
FADING. LATEST HRRR BRINGS A BAND OF REMNANT CONVECTION INTO THE FAR
WESTERN COUNTIES NEAR DAWN BEFORE SLIDING WEAKER SHOWERS EAST ACROSS
THE BLUE RIDGE...AND INTO THE EAST BEFORE FADING LATER THIS MORNING.
THUS BEEFED UP POPS WESTERN THIRD EARLY ON PENDING TRENDS BUT STAYED
WITH MAINLY CHANCE COVERAGE...EXCEPT LIKELYS MTN EMPIRE REGION
EARLY THIS MORNING FOR NOW GIVEN LESS INSTABILITY SEEN OUTSIDE THE
FAR WEST ATTM.
ONCE THIS FEATURE PASSES EAST...QUESTIONS WITH THE DEGREE OF ADDED
REDEVELOPMENT THIS AFTERNOON AS THE REMNANT MID LEVEL WAVE WORKS
EAST OF THE MOUNTAINS AND ENCOUNTERS THE EASTERN LEE TROF. MAIN
CONCERN IS WITH LACK OF DEEP INSTABILITY AS DEBRIS CLOUD SHIELD IN
THE WAKE OF THE REMNANT MCS COULD LINGER AND HELP INHIBIT ADDED
CONVECTION UNTIL LATE WITH ORGANIZATION LACKING. HOWEVER APPEARS
JUST ENOUGH HEATING/FOCUS TO HELP SCATTERED SHRA/TSRA REDEVELOP
OVER THE FAR WEST INITIALLY WHERE SHOULD SEE MORE SUN
SOONER...WITH COVERAGE HEADING OUT EAST LATER THIS AFTERNOON WHERE
AIDED BY POSSIBLE DIFFERENTIAL HEATING IF THE WESTERLY DOWNSLOPE
IS NOT TOO STRONG. THIS SIMILAR TO THE LATEST NCAR ENSEMBLE
ALTHOUGH SOLUTIONS QUITE VARIED FROM LITTLE ADDED PRECIP BEHIND
THE INITIAL MORNING BATCH PER NAM/CMC/EC...AND A COUPLE HIRES
MODELS...TO MOSTLY OVER THE WEST LIKE THE GFS. FOR NOW WILL LEAVE
IN CHANCE POPS MOST AREAS WITH BEST POTENTIAL FOR STRONGER PULSE
TSRA OVER THE SOUTH AND EAST WHERE FORECAST DCAPES ARE HIGHEST
PROVIDED SUFFICIENT HEATING DESPITE WEAK WIND FIELDS ALOFT. HIGH
TEMPS ALSO A BIT TRICKY GIVEN CLOUD SHIELD/SHRA EARLY AND PERHAPS
ENOUGH SUN TO REACH WARMER LATE DAY HIGHS OUT WEST. GIVEN
CLOUDIER TRENDS...LOWERED HIGHS A CAT OR SO WEST AND LEFT THE EAST
CLOSER TO THE COOLER MAV MOS AT THIS POINT.
WAVE PASSES TONIGHT WITH MOST EVENING CONVECTION LIKELY OVER THE
SOUTH AND EAST UNDER THE EXITING LOBE OF DEEPER MOISTURE. HOWEVER
UPSLOPE FLOW ACROSS THE NW ENOUGH TO KEEP SOME ISOLATED SHRA GOING
THERE OVERNIGHT WITH ONLY ISOLATED RESIDUAL -SHRA POSSIBLE ELSW
AFTER MIDNIGHT UNDER NW FLOW ALOFT AND LACK OF ADDED FOCUS. WILL
STILL BE WARM/MUGGY AS EXPECT MOIST DEWPOINTS AND CLOUDS TO HOLD
LOWS UP CLOSER TO THE 68-73 RANGE OVERALL.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 235 AM EDT SATURDAY...
AN UPPER LEVEL RIDGE WILL REMAIN OVER THE ARKLATEX REGION THROUGH
EARLY NEXT WEEK. THE POSITION OF THIS RIDGE MAY SEND A FEW
DISTURBANCES OUR WAY FROM THE MIDWEST...BUT THAT HAS YET TO BE SEEN
WITH THE LATEST MODELS. MODELS SUGGESTING A PULSE STORM ENVIRONMENT
WITH STORMS INITIATING OVER THE MOUNTAINS IN THE AFTERNOON...DRIFTING
EAST TO A LEE TROUGH OVER THE PIEDMONT IN THE EVENING. MODELS ARE A
LITTLE SLOWER WITH A COLD FRONT ENTERING THE OHIO VALLEY MONDAY.
THEREFORE WILL SLOW THE ARRIVAL OF ANY PREFRONTAL CONVECTION
ENTERING THE AREA UNTIL LATE MONDAY NIGHT-TUESDAY.
OUTSIDE OF SOME SCATTERED THUNDERSTORMS EACH AFTERNOON...THE HEAT
WILL BE THE MAIN TOPIC OF WEATHER CONVERSATIONS. TEMPERATURES SUNDAY
AND MONDAY AFTERNOON WILL RUN AROUND 5F WARMER THAN NORMAL...WITH
UPPER 80S WEST TO THE LOW TO MID 90S EAST. DEW POINTS WILL ALSO RUN
WARM AND IN THE UPPER 60S TO LOWER 70S. APPARENT TEMPERATURES...FOR
AT LEAST A FEW HOURS EACH AFTERNOON...WILL FEEL LIKE THE LOWER 90S
ACROSS THE MOUNTAINS AND AROUND 98F-103F ACROSS THE FOOTHILLS AND
PIEDMONT COUNTIES OF NW NC/SW VA.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 330 PM EDT FRIDAY...
EXPECT TO START TUESDAY MORNING WITH THE FRONT DRAPED AROUND OUR
AREA. LOW PRESSURE ARRIVING FROM THE WEST DURING THE AFTERNOON AND
EVENING WILL TRIGGER MORE SCATTERED SHOWER AND THUNDERSTORM ACTIVITY
FOR THE AFTERNOON AND EVENING. PASSAGE OF THE LOW ACROSS OUR AREA
WILL HELP PUSH THE FRONT INTO THE CAROLINAS TUESDAY NIGHT.
UPPER LEVEL WINDFLOW WILL TRANSITION TO A WEAK WEST TO EAST PATTERN
FOR THE MIDDLE OF NEXT WEEK...BRINGING A SERIES OF SUBTLE
DISTURBANCES ACROSS THE MID ATLANTIC. AS SUCH...EXPECT A CHANCE OF
SHOWERS AND THUNDERSTORMS EACH DAY...MAINLY THOSE WHICH DEVELOP WITH
DAYTIME HEATING. TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 145 PM EDT SATURDAY...
VFR CONDITIONS WILL PREVAIL ACROSS MOST OF THE REGION THROUGH THE
EARLY EVENING HOURS. ISOLATED TO SCATTERED SHOWERS AND STORMS ARE
EXPECTED TO DEVELOP AFTER 20-21Z/4PM-5PM. SOME BRIEF IFR/MVFR
CONDITIONS ARE EXPECTED UNDER THE HEAVY CORES THAT DEVELOP.
ANY SHOWERS OR STORMS THAT CONTINUE INTO THE EVENING HOURS WILL
WILL DISSIPATE BY 03Z/11PM. OVERNIGHT...ANTICIPATE SOME PATCHY
MVFR LIGHT FOG ALONG WITH SOME PATCHY MVFR STRATO-CU TO DEVELOP.
OTHERWISE...VFR CONDITIONS AND LIGHT OR CALM WINDS ARE EXPECTED.
ANY SUB-VFR CONDITIONS WILL IMPROVE TO VFR BY 12-13Z/8AM-9AM.
EXTENDED AVIATION DISCUSSION...
SUNDAY AFTERNOON AND EVENING SHOULD BRING MINIMAL CONVECTION AS A
SHORTWAVE RIDGE SITS OVER THE REGION ALONG A PREVAILING WESTERLY
FLOW.
MONDAY INTO TUESDAY...CONVECTION INCREASES AGAIN ACROSS THE AREA
WITH APPROACH AND PASSAGE OF A SHORTWAVE TROUGH AND ASSOCIATED
COLD FRONT. SUB-VFR CONDITIONS AGAIN WILL ACCOMPANY THE HEAVIER
CONVECTION.
WEDNESDAY...THE FRONTAL BOUNDARY MAY STILL BE CLOSE ENOUGH TO
SOUTHERN PORTION OF THE REGION FOR SOME LINGERING PRECIPITATION
AND SUB-VFR CONDITIONS.
HIGH PRESSURE LOOKS TO TAKE HOLD OF THE WEATHER FOR THE ENTIRE
REGION ON THURSDAY. EARLY MORNING MOUNTAIN AND RIVER VALLEY FOG
WILL BE POSSIBLE.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/RAB/WP
NEAR TERM...DS/JH
SHORT TERM...RCS
LONG TERM...AMS/NF
AVIATION...DS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
104 PM EDT SAT JUL 18 2015
.SYNOPSIS...
A WEAK TROUGH OF LOW PRESSURE WILL CROSS THE MOUNTAINS FROM THE
WEST THIS MORNING BEFORE EXITING THE PIEDMONT LATER THIS AFTERNOON.
ANOTHER WEAK FRONT WILL DRIFT INTO THE REGION FROM THE NORTHWEST
BY MONDAY...STALLING NEAR US AS WEAK WAVES OF LOW PRESSURE RIDE
ALONG THE BOUNDARY THROUGH THE FIRST HALF OF NEXT WEEK. THIS WILL
CONTINUE TO RESULT IN WARM AND HUMID CONDITIONS THROUGH THE PERIOD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM EDT SATURDAY...
CONVECTION IS STARTING TO TAKE PLACE JUST SOUTH OF THE
FORECAST AREA AND ALSO ACROSS THE FAR SOUTHEAST PART OF THE
FORECAST AREA. THIS REGION HAS BEEN OUTSIDE THE REGION OF
RESIDUAL CLOUD COVER FROM THE CONVECTION EARLY THIS MORNING. THAT
SAME CLOUD COVER HAS BEEN ERODING...AND IN ITS WAKE...AT LEAST
SOME CUMULUS CLOUDS HAVE BEEN FORMING ACROSS PARTS OF SOUTHWEST
VIRGINIA. ANTICIPATING ADDITIONAL DEVELOPMENT THIS AFTERNOON ACROSS
THE FORECAST AREA AS SURFACE HEATING CONTINUES. THE FOCUS FOR THE
BEST COVERAGE IS ACROSS THE PIEDMONT REGION WHERE THE LATEST SPC
DAY ONE CONVECTIVE OUTLOOK STILL PLACES A MARGINAL RISK IN THIS
AREA. HAVE TWEAKED HOURLY TEMPERATURE...DEW POINT AND SKY COVER
BASED UPON THE LATEST OBSERVATIONS AND EXPECTED TRENDS THROUGH THE
MID-AFTERNOON.
AS OF 945 AM EDT SATURDAY...
LITTLE REMAINS OF THE EARLIER DYING MCS THAT ENTERED THE REGION
EARLIER THIS MORNING. AT BEST...ISOLATED TO PATCHY LIGHT RAIN
SHOWERS WERE STILL NEAR AND NORTHEAST OF ROANOKE VIRGINIA ALONG
THE INTERSTATE-81 CORRIDOR. PLENTY OF RESIDUAL CLOUD COVER
CONTINUES TO EXIST ACROSS THE CENTRAL PORTION OF THE FORECAST
AREA...AND IS SLOW DRIFTING EASTWARD. THE FAR WESTERN AND
SOUTHEASTERN PARTS OF THE AREA ARE RECEIVING MOSTLY SUNNY TO SUNNY
CONDITIONS. IT WILL BE THESE TWO LOCATIONS THAT WILL HAVE THE BEST
OPPORTUNITY OF SHOWER AND THUNDERSTORM DEVELOPMENT HEADING INTO
THE AFTERNOON HOURS. WHILE THE CENTRAL PORTION OF THE AREA WILL
EVENTUALLY HAVE SOME SUNSHINE...IT WILL BE LATER IN THE DAY...AND
THIS REGION WILL BE SLOWER TO EXPERIENCE SURFACE BASED CONVECTION
DEVELOP. THAT IS NOT TO SAY THAT ACTIVITY THAT FORMS IN THE WEST
MAY NOT MOVE INTO CENTRAL PORTIONS LATER THIS AFTERNOON. THE
LATEST FORECAST UPDATE WILL REFLECT NO MAJOR CHANGES IN THE BIG
PICTURE TODAY. HOWEVER...IN THE NEAR TERM...A GREATER DISTINCTION
HAS BEEN MADE WHERE NO PRECIPITATION IS EXPECTED OVER THE NEXT FEW
HOURS VERSUS WHERE SCATTERED ACTIVITY IS EXPECTED. LIKEWISE...A
SIMILAR DISTINCTION HAS BEEN MADE TO CLOUDY VERSUS MOSTLY SUNNY TO
SUNNY AREAS.
AS OF 227 AM EDT SATURDAY...
MAIN CONCERN INITIALLY WITH RESIDUAL MCS CURRENTLY APPROACHING THE WESTERN
SLOPES AND JUST HOW FAR EAST THIS COMPLEX WILL GET THIS MORNING BEFORE
FADING. LATEST HRRR BRINGS A BAND OF REMNANT CONVECTION INTO THE FAR
WESTERN COUNTIES NEAR DAWN BEFORE SLIDING WEAKER SHOWERS EAST ACROSS
THE BLUE RIDGE...AND INTO THE EAST BEFORE FADING LATER THIS MORNING.
THUS BEEFED UP POPS WESTERN THIRD EARLY ON PENDING TRENDS BUT STAYED
WITH MAINLY CHANCE COVERAGE...EXCEPT LIKELYS MTN EMPIRE REGION
EARLY THIS MORNING FOR NOW GIVEN LESS INSTABILITY SEEN OUTSIDE THE
FAR WEST ATTM.
ONCE THIS FEATURE PASSES EAST...QUESTIONS WITH THE DEGREE OF ADDED
REDEVELOPMENT THIS AFTERNOON AS THE REMNANT MID LEVEL WAVE WORKS
EAST OF THE MOUNTAINS AND ENCOUNTERS THE EASTERN LEE TROF. MAIN
CONCERN IS WITH LACK OF DEEP INSTABILITY AS DEBRIS CLOUD SHIELD IN
THE WAKE OF THE REMNANT MCS COULD LINGER AND HELP INHIBIT ADDED
CONVECTION UNTIL LATE WITH ORGANIZATION LACKING. HOWEVER APPEARS
JUST ENOUGH HEATING/FOCUS TO HELP SCATTERED SHRA/TSRA REDEVELOP
OVER THE FAR WEST INITIALLY WHERE SHOULD SEE MORE SUN
SOONER...WITH COVERAGE HEADING OUT EAST LATER THIS AFTERNOON WHERE
AIDED BY POSSIBLE DIFFERENTIAL HEATING IF THE WESTERLY DOWNSLOPE
IS NOT TOO STRONG. THIS SIMILAR TO THE LATEST NCAR ENSEMBLE
ALTHOUGH SOLUTIONS QUITE VARIED FROM LITTLE ADDED PRECIP BEHIND
THE INITIAL MORNING BATCH PER NAM/CMC/EC...AND A COUPLE HIRES
MODELS...TO MOSTLY OVER THE WEST LIKE THE GFS. FOR NOW WILL LEAVE
IN CHANCE POPS MOST AREAS WITH BEST POTENTIAL FOR STRONGER PULSE
TSRA OVER THE SOUTH AND EAST WHERE FORECAST DCAPES ARE HIGHEST
PROVIDED SUFFICIENT HEATING DESPITE WEAK WIND FIELDS ALOFT. HIGH
TEMPS ALSO A BIT TRICKY GIVEN CLOUD SHIELD/SHRA EARLY AND PERHAPS
ENOUGH SUN TO REACH WARMER LATE DAY HIGHS OUT WEST. GIVEN
CLOUDIER TRENDS...LOWERED HIGHS A CAT OR SO WEST AND LEFT THE EAST
CLOSER TO THE COOLER MAV MOS AT THIS POINT.
WAVE PASSES TONIGHT WITH MOST EVENING CONVECTION LIKELY OVER THE
SOUTH AND EAST UNDER THE EXITING LOBE OF DEEPER MOISTURE. HOWEVER
UPSLOPE FLOW ACROSS THE NW ENOUGH TO KEEP SOME ISOLATED SHRA GOING
THERE OVERNIGHT WITH ONLY ISOLATED RESIDUAL -SHRA POSSIBLE ELSW
AFTER MIDNIGHT UNDER NW FLOW ALOFT AND LACK OF ADDED FOCUS. WILL
STILL BE WARM/MUGGY AS EXPECT MOIST DEWPOINTS AND CLOUDS TO HOLD
LOWS UP CLOSER TO THE 68-73 RANGE OVERALL.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 235 AM EDT SATURDAY...
AN UPPER LEVEL RIDGE WILL REMAIN OVER THE ARKLATEX REGION THROUGH
EARLY NEXT WEEK. THE POSITION OF THIS RIDGE MAY SEND A FEW
DISTURBANCES OUR WAY FROM THE MIDWEST...BUT THAT HAS YET TO BE SEEN
WITH THE LATEST MODELS. MODELS SUGGESTING A PULSE STORM ENVIRONMENT
WITH STORMS INITIATING OVER THE MOUNTAINS IN THE AFTERNOON...DRIFTING
EAST TO A LEE TROUGH OVER THE PIEDMONT IN THE EVENING. MODELS ARE A
LITTLE SLOWER WITH A COLD FRONT ENTERING THE OHIO VALLEY MONDAY.
THEREFORE WILL SLOW THE ARRIVAL OF ANY PREFRONTAL CONVECTION
ENTERING THE AREA UNTIL LATE MONDAY NIGHT-TUESDAY.
OUTSIDE OF SOME SCATTERED THUNDERSTORMS EACH AFTERNOON...THE HEAT
WILL BE THE MAIN TOPIC OF WEATHER CONVERSATIONS. TEMPERATURES SUNDAY
AND MONDAY AFTERNOON WILL RUN AROUND 5F WARMER THAN NORMAL...WITH
UPPER 80S WEST TO THE LOW TO MID 90S EAST. DEW POINTS WILL ALSO RUN
WARM AND IN THE UPPER 60S TO LOWER 70S. APPARENT TEMPERATURES...FOR
AT LEAST A FEW HOURS EACH AFTERNOON...WILL FEEL LIKE THE LOWER 90S
ACROSS THE MOUNTAINS AND AROUND 98F-103F ACROSS THE FOOTHILLS AND
PIEDMONT COUNTIES OF NW NC/SW VA.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 330 PM EDT FRIDAY...
EXPECT TO START TUESDAY MORNING WITH THE FRONT DRAPED AROUND OUR
AREA. LOW PRESSURE ARRIVING FROM THE WEST DURING THE AFTERNOON AND
EVENING WILL TRIGGER MORE SCATTERED SHOWER AND THUNDERSTORM ACTIVITY
FOR THE AFTERNOON AND EVENING. PASSAGE OF THE LOW ACROSS OUR AREA
WILL HELP PUSH THE FRONT INTO THE CAROLINAS TUESDAY NIGHT.
UPPER LEVEL WINDFLOW WILL TRANSITION TO A WEAK WEST TO EAST PATTERN
FOR THE MIDDLE OF NEXT WEEK...BRINGING A SERIES OF SUBTLE
DISTURBANCES ACROSS THE MID ATLANTIC. AS SUCH...EXPECT A CHANCE OF
SHOWERS AND THUNDERSTORMS EACH DAY...MAINLY THOSE WHICH DEVELOP WITH
DAYTIME HEATING. TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 640 AM EDT SATURDAY...
CLUSTERS OF SHRA/TSRA CONTINUE OVER PARTS OF THE MOUNTAINS EARLY
THIS MORNING...BUT MAINLY REMOVED FROM ANY OF THE TAF SITES.
EXPECT A FEW ADDED SHOWERS MAY AFFECT KBLF/KLWB THROUGH MID
MORNING SO INCLUDING MAINLY A VCSH/VCTS FOR A COUPLE MORE HOURS
THIS MORNING. SOME OF THESE SHOWERS MAY ALSO WORK OUT TO KBCB
AND KROA BUT TOO IFFY TO INCLUDE A VCSH MENTION FOR NOW.
ADDITIONAL SHOWER DEVELOPMENT MAY PUSH INTO EASTERN SECTIONS
THIS MORNING AS WELL WITH DEBRIS CLOUDS MAKING FOR LINGERING LOW
END VFR TO MVFR CIGS OVER THE WEST AND THROUGH MIDDAY. SHOULD
FINALLY SEE A RETURN TO VFR FOR A WHILE THIS AFTERNOON AS HEATING
WINS OUT WITH THE BEST THREAT FOR ADDED CONVECTION IN THE LEE OF
THE RIDGES AS THE REMNANT WAVE HEADS EAST AND COMBINES WITH
AFTERNOON HEATING. EXPECT CIGS BY LATE MORNING TO BE IN THE MID
DECK/AC AREA...WITH SCT TO BKN CU FORMING IN THE AFTERNOON AROUND
4-5KFT. KEPT VCTS AT KROA/KLYH/KDAN WHERE POPS ARE HIGHEST AND
ADDED IN AT KBLF AROUND 19Z AND BEYOND GIVEN POTENTIAL FOR HEATING
TO REBOUND BEHIND THE EARLY CLOUD SHIELD/SHRA.
ANY LINGERING SHOWERS SHOULD EXIT THE EAST/SOUTH THIS EVENING
FOLLOWED BY CLEARING SKIES UNDER LIGHT WINDS. THIS MAY LEAD TO FOG
DEVELOPMENT ESPCLY IN THE VALLEYS OVERNIGHT AND AT ANY LOCATION
THAT SEES HEAVIER DOWNPOURS TODAY. APPEARS KLWB LIKELY TO DROP
DOWN TO LIFR IN FOG/STRATUS WITH MVFR TO IFR AT KBCB AND PERHAPS A
PERIOD OF MVFR OR WORSE AT KLYH/KDAN LATE TONIGHT.
EXTENDED AVIATION DISCUSSION...
SUNDAY APPEARS TO BRING A MINIMUM IN CONVECTION WITH SHORT WAVE
RIDGING. MONDAY SHOULD SEE AN INCREASE IN CONVECTION
AGAIN...POTENTIALLY LINGERING INTO TUESDAY WITH WAVES OF LOW
PRESSURE RIDING THROUGH THE REGION IN A WEST TO WEST- NORTHWEST
FLOW. BOUNDARY MAY PUSH FAR ENOUGH SOUTH IN THE WAKE OF THE
CONVECTION TO BRING MAINLY VFR WITH ONLY ISOLATED
AFTERNOON/EVENING SHRA/TSRA ACROSS THE SOUTH ON WEDNESDAY.
OUTSIDE SHRA/TSRA AND EARLY MORNING FOG/LOW CLOUDS...GENERALLY
VFR CONDITIONS EXPECTED THROUGH MUCH OF THE PERIOD.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/RAB/WP
NEAR TERM...DS/JH
SHORT TERM...RCS
LONG TERM...AMS/NF
AVIATION...JH/JR/RAB/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
953 AM EDT SAT JUL 18 2015
.SYNOPSIS...
A WEAK TROUGH OF LOW PRESSURE WILL CROSS THE MOUNTAINS FROM THE
WEST THIS MORNING BEFORE EXITING THE PIEDMONT LATER THIS AFTERNOON.
ANOTHER WEAK FRONT WILL DRIFT INTO THE REGION FROM THE NORTHWEST
BY MONDAY...STALLING NEAR US AS WEAK WAVES OF LOW PRESSURE RIDE
ALONG THE BOUNDARY THROUGH THE FIRST HALF OF NEXT WEEK. THIS WILL
CONTINUE TO RESULT IN WARM AND HUMID CONDITIONS THROUGH THE PERIOD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM EDT SATURDAY...
LITTLE REMAINS OF THE EARLIER DYING MCS THAT ENTERED THE REGION
EARLIER THIS MORNING. AT BEST...ISOLATED TO PATCHY LIGHT RAIN
SHOWERS WERE STILL NEAR AND NORTHEAST OF ROANOKE VIRGINIA ALONG
THE INTERSTATE-81 CORRIDOR. PLENTY OF RESIDUAL CLOUD COVER
CONTINUES TO EXIST ACROSS THE CENTRAL PORTION OF THE FORECAST
AREA...AND IS SLOW DRIFTING EASTWARD. THE FAR WESTERN AND
SOUTHEASTERN PARTS OF THE AREA ARE RECEIVING MOSTLY SUNNY TO SUNNY
CONDITIONS. IT WILL BE THESE TWO LOCATIONS THAT WILL HAVE THE BEST
OPPORTUNITY OF SHOWER AND THUNDERSTORM DEVELOPMENT HEADING INTO
THE AFTERNOON HOURS. WHILE THE CENTRAL PORTION OF THE AREA WILL
EVENTUALLY HAVE SOME SUNSHINE...IT WILL BE LATER IN THE DAY...AND
THIS REGION WILL BE SLOWER TO EXPERIENCE SURFACE BASED CONVECTION
DEVELOP. THAT IS NOT TO SAY THAT ACTIVITY THAT FORMS IN THE WEST
MAY NOT MOVE INTO CENTRAL PORTIONS LATER THIS AFTERNOON. THE
LATEST FORECAST UPDATE WILL REFLECT NO MAJOR CHANGES IN THE BIG
PICTURE TODAY. HOWEVER...IN THE NEAR TERM...A GREATER DISTINCTION
HAS BEEN MADE WHERE NO PRECIPITATION IS EXPECTED OVER THE NEXT FEW
HOURS VERSUS WHERE SCATTERED ACTIVITY IS EXPECTED. LIKEWISE...A
SIMILAR DISTINCTION HAS BEEN MADE TO CLOUDY VERSUS MOSTLY SUNNY TO
SUNNY AREAS.
AS OF 227 AM EDT SATURDAY...
MAIN CONCERN INITIALLY WITH RESIDUAL MCS CURRENTLY APPROACHING THE WESTERN
SLOPES AND JUST HOW FAR EAST THIS COMPLEX WILL GET THIS MORNING BEFORE
FADING. LATEST HRRR BRINGS A BAND OF REMNANT CONVECTION INTO THE FAR
WESTERN COUNTIES NEAR DAWN BEFORE SLIDING WEAKER SHOWERS EAST ACROSS
THE BLUE RIDGE...AND INTO THE EAST BEFORE FADING LATER THIS MORNING.
THUS BEEFED UP POPS WESTERN THIRD EARLY ON PENDING TRENDS BUT STAYED
WITH MAINLY CHANCE COVERAGE...EXCEPT LIKELYS MTN EMPIRE REGION
EARLY THIS MORNING FOR NOW GIVEN LESS INSTABILITY SEEN OUTSIDE THE
FAR WEST ATTM.
ONCE THIS FEATURE PASSES EAST...QUESTIONS WITH THE DEGREE OF ADDED
REDEVELOPMENT THIS AFTERNOON AS THE REMNANT MID LEVEL WAVE WORKS
EAST OF THE MOUNTAINS AND ENCOUNTERS THE EASTERN LEE TROF. MAIN
CONCERN IS WITH LACK OF DEEP INSTABILITY AS DEBRIS CLOUD SHIELD IN
THE WAKE OF THE REMNANT MCS COULD LINGER AND HELP INHIBIT ADDED
CONVECTION UNTIL LATE WITH ORGANIZATION LACKING. HOWEVER APPEARS
JUST ENOUGH HEATING/FOCUS TO HELP SCATTERED SHRA/TSRA REDEVELOP
OVER THE FAR WEST INITIALLY WHERE SHOULD SEE MORE SUN
SOONER...WITH COVERAGE HEADING OUT EAST LATER THIS AFTERNOON WHERE
AIDED BY POSSIBLE DIFFERENTIAL HEATING IF THE WESTERLY DOWNSLOPE
IS NOT TOO STRONG. THIS SIMILAR TO THE LATEST NCAR ENSEMBLE
ALTHOUGH SOLUTIONS QUITE VARIED FROM LITTLE ADDED PRECIP BEHIND
THE INITIAL MORNING BATCH PER NAM/CMC/EC...AND A COUPLE HIRES
MODELS...TO MOSTLY OVER THE WEST LIKE THE GFS. FOR NOW WILL LEAVE
IN CHANCE POPS MOST AREAS WITH BEST POTENTIAL FOR STRONGER PULSE
TSRA OVER THE SOUTH AND EAST WHERE FORECAST DCAPES ARE HIGHEST
PROVIDED SUFFICIENT HEATING DESPITE WEAK WIND FIELDS ALOFT. HIGH
TEMPS ALSO A BIT TRICKY GIVEN CLOUD SHIELD/SHRA EARLY AND PERHAPS
ENOUGH SUN TO REACH WARMER LATE DAY HIGHS OUT WEST. GIVEN
CLOUDIER TRENDS...LOWERED HIGHS A CAT OR SO WEST AND LEFT THE EAST
CLOSER TO THE COOLER MAV MOS AT THIS POINT.
WAVE PASSES TONIGHT WITH MOST EVENING CONVECTION LIKELY OVER THE
SOUTH AND EAST UNDER THE EXITING LOBE OF DEEPER MOISTURE. HOWEVER
UPSLOPE FLOW ACROSS THE NW ENOUGH TO KEEP SOME ISOLATED SHRA GOING
THERE OVERNIGHT WITH ONLY ISOLATED RESIDUAL -SHRA POSSIBLE ELSW
AFTER MIDNIGHT UNDER NW FLOW ALOFT AND LACK OF ADDED FOCUS. WILL
STILL BE WARM/MUGGY AS EXPECT MOIST DEWPOINTS AND CLOUDS TO HOLD
LOWS UP CLOSER TO THE 68-73 RANGE OVERALL.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 235 AM EDT SATURDAY...
AN UPPER LEVEL RIDGE WILL REMAIN OVER THE ARKLATEX REGION THROUGH
EARLY NEXT WEEK. THE POSITION OF THIS RIDGE MAY SEND A FEW
DISTURBANCES OUR WAY FROM THE MIDWEST...BUT THAT HAS YET TO BE SEEN
WITH THE LATEST MODELS. MODELS SUGGESTING A PULSE STORM ENVIRONMENT
WITH STORMS INITIATING OVER THE MOUNTAINS IN THE AFTERNOON...DRIFTING
EAST TO A LEE TROUGH OVER THE PIEDMONT IN THE EVENING. MODELS ARE A
LITTLE SLOWER WITH A COLD FRONT ENTERING THE OHIO VALLEY MONDAY.
THEREFORE WILL SLOW THE ARRIVAL OF ANY PREFRONTAL CONVECTION
ENTERING THE AREA UNTIL LATE MONDAY NIGHT-TUESDAY.
OUTSIDE OF SOME SCATTERED THUNDERSTORMS EACH AFTERNOON...THE HEAT
WILL BE THE MAIN TOPIC OF WEATHER CONVERSATIONS. TEMPERATURES SUNDAY
AND MONDAY AFTERNOON WILL RUN AROUND 5F WARMER THAN NORMAL...WITH
UPPER 80S WEST TO THE LOW TO MID 90S EAST. DEW POINTS WILL ALSO RUN
WARM AND IN THE UPPER 60S TO LOWER 70S. APPARENT TEMPERATURES...FOR
AT LEAST A FEW HOURS EACH AFTERNOON...WILL FEEL LIKE THE LOWER 90S
ACROSS THE MOUNTAINS AND AROUND 98F-103F ACROSS THE FOOTHILLS AND
PIEDMONT COUNTIES OF NW NC/SW VA.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 330 PM EDT FRIDAY...
EXPECT TO START TUESDAY MORNING WITH THE FRONT DRAPED AROUND OUR
AREA. LOW PRESSURE ARRIVING FROM THE WEST DURING THE AFTERNOON AND
EVENING WILL TRIGGER MORE SCATTERED SHOWER AND THUNDERSTORM ACTIVITY
FOR THE AFTERNOON AND EVENING. PASSAGE OF THE LOW ACROSS OUR AREA
WILL HELP PUSH THE FRONT INTO THE CAROLINAS TUESDAY NIGHT.
UPPER LEVEL WINDFLOW WILL TRANSITION TO A WEAK WEST TO EAST PATTERN
FOR THE MIDDLE OF NEXT WEEK...BRINGING A SERIES OF SUBTLE
DISTURBANCES ACROSS THE MID ATLANTIC. AS SUCH...EXPECT A CHANCE OF
SHOWERS AND THUNDERSTORMS EACH DAY...MAINLY THOSE WHICH DEVELOP WITH
DAYTIME HEATING. TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
AS OF 640 AM EDT SATURDAY...
CLUSTERS OF SHRA/TSRA CONTINUE OVER PARTS OF THE MOUNTAINS EARLY
THIS MORNING...BUT MAINLY REMOVED FROM ANY OF THE TAF SITES.
EXPECT A FEW ADDED SHOWERS MAY AFFECT KBLF/KLWB THROUGH MID
MORNING SO INCLUDING MAINLY A VCSH/VCTS FOR A COUPLE MORE HOURS
THIS MORNING. SOME OF THESE SHOWERS MAY ALSO WORK OUT TO KBCB
AND KROA BUT TOO IFFY TO INCLUDE A VCSH MENTION FOR NOW.
ADDITIONAL SHOWER DEVELOPMENT MAY PUSH INTO EASTERN SECTIONS
THIS MORNING AS WELL WITH DEBRIS CLOUDS MAKING FOR LINGERING LOW
END VFR TO MVFR CIGS OVER THE WEST AND THROUGH MIDDAY. SHOULD
FINALLY SEE A RETURN TO VFR FOR A WHILE THIS AFTERNOON AS HEATING
WINS OUT WITH THE BEST THREAT FOR ADDED CONVECTION IN THE LEE OF
THE RIDGES AS THE REMNANT WAVE HEADS EAST AND COMBINES WITH
AFTERNOON HEATING. EXPECT CIGS BY LATE MORNING TO BE IN THE MID
DECK/AC AREA...WITH SCT TO BKN CU FORMING IN THE AFTERNOON AROUND
4-5KFT. KEPT VCTS AT KROA/KLYH/KDAN WHERE POPS ARE HIGHEST AND
ADDED IN AT KBLF AROUND 19Z AND BEYOND GIVEN POTENTIAL FOR HEATING
TO REBOUND BEHIND THE EARLY CLOUD SHIELD/SHRA.
ANY LINGERING SHOWERS SHOULD EXIT THE EAST/SOUTH THIS EVENING
FOLLOWED BY CLEARING SKIES UNDER LIGHT WINDS. THIS MAY LEAD TO FOG
DEVELOPMENT ESPCLY IN THE VALLEYS OVERNIGHT AND AT ANY LOCATION
THAT SEES HEAVIER DOWNPOURS TODAY. APPEARS KLWB LIKELY TO DROP
DOWN TO LIFR IN FOG/STRATUS WITH MVFR TO IFR AT KBCB AND PERHAPS A
PERIOD OF MVFR OR WORSE AT KLYH/KDAN LATE TONIGHT.
EXTENDED AVIATION DISCUSSION...
SUNDAY APPEARS TO BRING A MINIMUM IN CONVECTION WITH SHORT WAVE
RIDGING. MONDAY SHOULD SEE AN INCREASE IN CONVECTION
AGAIN...POTENTIALLY LINGERING INTO TUESDAY WITH WAVES OF LOW
PRESSURE RIDING THROUGH THE REGION IN A WEST TO WEST- NORTHWEST
FLOW. BOUNDARY MAY PUSH FAR ENOUGH SOUTH IN THE WAKE OF THE
CONVECTION TO BRING MAINLY VFR WITH ONLY ISOLATED
AFTERNOON/EVENING SHRA/TSRA ACROSS THE SOUTH ON WEDNESDAY.
OUTSIDE SHRA/TSRA AND EARLY MORNING FOG/LOW CLOUDS...GENERALLY
VFR CONDITIONS EXPECTED THROUGH MUCH OF THE PERIOD.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/RAB/WP
NEAR TERM...DS/JH
SHORT TERM...RCS
LONG TERM...AMS/NF
AVIATION...JH/JR/RAB/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
654 AM EDT SAT JUL 18 2015
.SYNOPSIS...
A WEAK TROUGH OF LOW PRESSURE WILL CROSS THE MOUNTAINS FROM THE
WEST THIS MORNING BEFORE EXITING THE PIEDMONT LATER THIS AFTERNOON.
ANOTHER WEAK FRONT WILL DRIFT INTO THE REGION FROM THE NORTHWEST
BY MONDAY...STALLING NEAR US AS WEAK WAVES OF LOW PRESSURE RIDE
ALONG THE BOUNDARY THROUGH THE FIRST HALF OF NEXT WEEK. THIS WILL
CONTINUE TO RESULT IN WARM AND HUMID CONDITIONS THROUGH THE PERIOD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 227 AM EDT SATURDAY...
MAIN CONCERN INITIALLY WITH RESIDUAL MCS CURRENTLY APPROACHING THE WESTERN
SLOPES AND JUST HOW FAR EAST THIS COMPLEX WILL GET THIS MORNING BEFORE
FADING. LATEST HRRR BRINGS A BAND OF REMNANT CONVECTION INTO THE FAR
WESTERN COUNTIES NEAR DAWN BEFORE SLIDING WEAKER SHOWERS EAST ACROSS
THE BLUE RIDGE...AND INTO THE EAST BEFORE FADING LATER THIS MORNING.
THUS BEEFED UP POPS WESTERN THIRD EARLY ON PENDING TRENDS BUT STAYED
WITH MAINLY CHANCE COVERAGE...EXCEPT LIKELYS MTN EMPIRE REGION
EARLY THIS MORNING FOR NOW GIVEN LESS INSTABILITY SEEN OUTSIDE THE
FAR WEST ATTM.
ONCE THIS FEATURE PASSES EAST...QUESTIONS WITH THE DEGREE OF ADDED
REDEVELOPMENT THIS AFTERNOON AS THE REMNANT MID LEVEL WAVE WORKS
EAST OF THE MOUNTAINS AND ENCOUNTERS THE EASTERN LEE TROF. MAIN
CONCERN IS WITH LACK OF DEEP INSTABILITY AS DEBRIS CLOUD SHIELD IN
THE WAKE OF THE REMNANT MCS COULD LINGER AND HELP INHIBIT ADDED
CONVECTION UNTIL LATE WITH ORGANIZATION LACKING. HOWEVER APPEARS
JUST ENOUGH HEATING/FOCUS TO HELP SCATTERED SHRA/TSRA REDEVELOP
OVER THE FAR WEST INITIALLY WHERE SHOULD SEE MORE SUN
SOONER...WITH COVERAGE HEADING OUT EAST LATER THIS AFTERNOON WHERE
AIDED BY POSSIBLE DIFFERENTIAL HEATING IF THE WESTERLY DOWNSLOPE
IS NOT TOO STRONG. THIS SIMILAR TO THE LATEST NCAR ENSEMBLE
ALTHOUGH SOLUTIONS QUITE VARIED FROM LITTLE ADDED PRECIP BEHIND
THE INITIAL MORNING BATCH PER NAM/CMC/EC...AND A COUPLE HIRES
MODELS...TO MOSTLY OVER THE WEST LIKE THE GFS. FOR NOW WILL LEAVE
IN CHANCE POPS MOST AREAS WITH BEST POTENTIAL FOR STRONGER PULSE
TSRA OVER THE SOUTH AND EAST WHERE FORECAST DCAPES ARE HIGHEST
PROVIDED SUFFICIENT HEATING DESPITE WEAK WIND FIELDS ALOFT. HIGH
TEMPS ALSO A BIT TRICKY GIVEN CLOUD SHIELD/SHRA EARLY AND PERHAPS
ENOUGH SUN TO REACH WARMER LATE DAY HIGHS OUT WEST. GIVEN
CLOUDIER TRENDS...LOWERED HIGHS A CAT OR SO WEST AND LEFT THE EAST
CLOSER TO THE COOLER MAV MOS AT THIS POINT.
WAVE PASSES TONIGHT WITH MOST EVENING CONVECTION LIKELY OVER THE
SOUTH AND EAST UNDER THE EXITING LOBE OF DEEPER MOISTURE. HOWEVER
UPSLOPE FLOW ACROSS THE NW ENOUGH TO KEEP SOME ISOLATED SHRA GOING
THERE OVERNIGHT WITH ONLY ISOLATED RESIDUAL -SHRA POSSIBLE ELSW
AFTER MIDNIGHT UNDER NW FLOW ALOFT AND LACK OF ADDED FOCUS. WILL
STILL BE WARM/MUGGY AS EXPECT MOIST DEWPOINTS AND CLOUDS TO HOLD
LOWS UP CLOSER TO THE 68-73 RANGE OVERALL.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 235 AM EDT SATURDAY...
AN UPPER LEVEL RIDGE WILL REMAIN OVER THE ARKLATEX REGION THROUGH
EARLY NEXT WEEK. THE POSITION OF THIS RIDGE MAY SEND A FEW
DISTURBANCES OUR WAY FROM THE MIDWEST...BUT THAT HAS YET TO BE SEEN
WITH THE LATEST MODELS. MODELS SUGGESTING A PULSE STORM ENVIRONMENT
WITH STORMS INITIATING OVER THE MOUNTAINS IN THE AFTERNOON...DRIFTING
EAST TO A LEE TROUGH OVER THE PIEDMONT IN THE EVENING. MODELS ARE A
LITTLE SLOWER WITH A COLD FRONT ENTERING THE OHIO VALLEY MONDAY.
THEREFORE WILL SLOW THE ARRIVAL OF ANY PREFRONTAL CONVECTION
ENTERING THE AREA UNTIL LATE MONDAY NIGHT-TUESDAY.
OUTSIDE OF SOME SCATTERED THUNDERSTORMS EACH AFTERNOON...THE HEAT
WILL BE THE MAIN TOPIC OF WEATHER CONVERSATIONS. TEMPERATURES SUNDAY
AND MONDAY AFTERNOON WILL RUN AROUND 5F WARMER THAN NORMAL...WITH
UPPER 80S WEST TO THE LOW TO MID 90S EAST. DEW POINTS WILL ALSO RUN
WARM AND IN THE UPPER 60S TO LOWER 70S. APPARENT TEMPERATURES...FOR
AT LEAST A FEW HOURS EACH AFTERNOON...WILL FEEL LIKE THE LOWER 90S
ACROSS THE MOUNTAINS AND AROUND 98F-103F ACROSS THE FOOTHILLS AND
PIEDMONT COUNTIES OF NW NC/SW VA.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 330 PM EDT FRIDAY...
EXPECT TO START TUESDAY MORNING WITH THE FRONT DRAPED AROUND OUR
AREA. LOW PRESSURE ARRIVING FROM THE WEST DURING THE AFTERNOON AND
EVENING WILL TRIGGER MORE SCATTERED SHOWER AND THUNDERSTORM ACTIVITY
FOR THE AFTERNOON AND EVENING. PASSAGE OF THE LOW ACROSS OUR AREA
WILL HELP PUSH THE FRONT INTO THE CAROLINAS TUESDAY NIGHT.
UPPER LEVEL WINDFLOW WILL TRANSITION TO A WEAK WEST TO EAST PATTERN
FOR THE MIDDLE OF NEXT WEEK...BRINGING A SERIES OF SUBTLE
DISTURBANCES ACROSS THE MID ATLANTIC. AS SUCH...EXPECT A CHANCE OF
SHOWERS AND THUNDERSTORMS EACH DAY...MAINLY THOSE WHICH DEVELOP WITH
DAYTIME HEATING. TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 640 AM EDT SATURDAY...
CLUSTERS OF SHRA/TSRA CONTINUE OVER PARTS OF THE MOUNTAINS EARLY
THIS MORNING...BUT MAINLY REMOVED FROM ANY OF THE TAF SITES.
EXPECT A FEW ADDED SHOWERS MAY AFFECT KBLF/KLWB THROUGH MID
MORNING SO INCLUDING MAINLY A VCSH/VCTS FOR A COUPLE MORE HOURS
THIS MORNING. SOME OF THESE SHOWERS MAY ALSO WORK OUT TO KBCB
AND KROA BUT TOO IFFY TO INCLUDE A VCSH MENTION FOR NOW.
ADDITIONAL SHOWER DEVELOPMENT MAY PUSH INTO EASTERN SECTIONS
THIS MORNING AS WELL WITH DEBRIS CLOUDS MAKING FOR LINGERING LOW
END VFR TO MVFR CIGS OVER THE WEST AND THROUGH MIDDAY. SHOULD
FINALLY SEE A RETURN TO VFR FOR A WHILE THIS AFTERNOON AS HEATING
WINS OUT WITH THE BEST THREAT FOR ADDED CONVECTION IN THE LEE OF
THE RIDGES AS THE REMNANT WAVE HEADS EAST AND COMBINES WITH
AFTERNOON HEATING. EXPECT CIGS BY LATE MORNING TO BE IN THE MID
DECK/AC AREA...WITH SCT TO BKN CU FORMING IN THE AFTERNOON AROUND
4-5KFT. KEPT VCTS AT KROA/KLYH/KDAN WHERE POPS ARE HIGHEST AND
ADDED IN AT KBLF AROUND 19Z AND BEYOND GIVEN POTENTIAL FOR HEATING
TO REBOUND BEHIND THE EARLY CLOUD SHIELD/SHRA.
ANY LINGERING SHOWERS SHOULD EXIT THE EAST/SOUTH THIS EVENING
FOLLOWED BY CLEARING SKIES UNDER LIGHT WINDS. THIS MAY LEAD TO FOG
DEVELOPMENT ESPCLY IN THE VALLEYS OVERNIGHT AND AT ANY LOCATION
THAT SEES HEAVIER DOWNPOURS TODAY. APPEARS KLWB LIKELY TO DROP
DOWN TO LIFR IN FOG/STRATUS WITH MVFR TO IFR AT KBCB AND PERHAPS A
PERIOD OF MVFR OR WORSE AT KLYH/KDAN LATE TONIGHT.
EXTENDED AVIATION DISCUSSION...
SUNDAY APPEARS TO BRING A MINIMUM IN CONVECTION WITH SHORT WAVE
RIDGING. MONDAY SHOULD SEE AN INCREASE IN CONVECTION
AGAIN...POTENTIALLY LINGERING INTO TUESDAY WITH WAVES OF LOW
PRESSURE RIDING THROUGH THE REGION IN A WEST TO WEST- NORTHWEST
FLOW. BOUNDARY MAY PUSH FAR ENOUGH SOUTH IN THE WAKE OF THE
CONVECTION TO BRING MAINLY VFR WITH ONLY ISOLATED
AFTERNOON/EVENING SHRA/TSRA ACROSS THE SOUTH ON WEDNESDAY.
OUTSIDE SHRA/TSRA AND EARLY MORNING FOG/LOW CLOUDS...GENERALLY
VFR CONDITIONS EXPECTED THROUGH MUCH OF THE PERIOD.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/RAB/WP
NEAR TERM...JH
SHORT TERM...RCS
LONG TERM...AMS/NF
AVIATION...JH/JR/RAB/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
320 AM EDT SAT JUL 18 2015
.SYNOPSIS...
A WEAK TROUGH OF LOW PRESSURE WILL CROSS THE MOUNTAINS FROM THE
WEST THIS MORNING BEFORE EXITING THE PIEDMONT LATER THIS AFTERNOON.
ANOTHER WEAK FRONT WILL DRIFT INTO THE REGION FROM THE NORTHWEST
BY MONDAY...STALLING NEAR US AS WEAK WAVES OF LOW PRESSURE RIDE
ALONG THE BOUNDARY THROUGH THE FIRST HALF OF NEXT WEEK. THIS WILL
CONTINUE TO RESULT IN WARM AND HUMID CONDITIONS THROUGH THE PERIOD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 227 AM EDT SATURDAY...
MAIN CONCERN INITIALLY WITH RESIDUAL MCS CURRENTLY APPROACHING THE WESTERN
SLOPES AND JUST HOW FAR EAST THIS COMPLEX WILL GET THIS MORNING BEFORE
FADING. LATEST HRRR BRINGS A BAND OF REMNANT CONVECTION INTO THE FAR
WESTERN COUNTIES NEAR DAWN BEFORE SLIDING WEAKER SHOWERS EAST ACROSS
THE BLUE RIDGE...AND INTO THE EAST BEFORE FADING LATER THIS MORNING.
THUS BEEFED UP POPS WESTERN THIRD EARLY ON PENDING TRENDS BUT STAYED
WITH MAINLY CHANCE COVERAGE...EXCEPT LIKELYS MTN EMPIRE REGION
EARLY THIS MORNING FOR NOW GIVEN LESS INSTABILITY SEEN OUTSIDE THE
FAR WEST ATTM.
ONCE THIS FEATURE PASSES EAST...QUESTIONS WITH THE DEGREE OF ADDED
REDEVELOPMENT THIS AFTERNOON AS THE REMNANT MID LEVEL WAVE WORKS
EAST OF THE MOUNTAINS AND ENCOUNTERS THE EASTERN LEE TROF. MAIN
CONCERN IS WITH LACK OF DEEP INSTABILITY AS DEBRIS CLOUD SHIELD IN
THE WAKE OF THE REMNANT MCS COULD LINGER AND HELP INHIBIT ADDED
CONVECTION UNTIL LATE WITH ORGANIZATION LACKING. HOWEVER APPEARS
JUST ENOUGH HEATING/FOCUS TO HELP SCATTERED SHRA/TSRA REDEVELOP
OVER THE FAR WEST INITIALLY WHERE SHOULD SEE MORE SUN
SOONER...WITH COVERAGE HEADING OUT EAST LATER THIS AFTERNOON WHERE
AIDED BY POSSIBLE DIFFERENTIAL HEATING IF THE WESTERLY DOWNSLOPE
IS NOT TOO STRONG. THIS SIMILAR TO THE LATEST NCAR ENSEMBLE
ALTHOUGH SOLUTIONS QUITE VARIED FROM LITTLE ADDED PRECIP BEHIND
THE INITIAL MORNING BATCH PER NAM/CMC/EC...AND A COUPLE HIRES
MODELS...TO MOSTLY OVER THE WEST LIKE THE GFS. FOR NOW WILL LEAVE
IN CHANCE POPS MOST AREAS WITH BEST POTENTIAL FOR STRONGER PULSE
TSRA OVER THE SOUTH AND EAST WHERE FORECAST DCAPES ARE HIGHEST
PROVIDED SUFFICIENT HEATING DESPITE WEAK WIND FIELDS ALOFT. HIGH
TEMPS ALSO A BIT TRICKY GIVEN CLOUD SHIELD/SHRA EARLY AND PERHAPS
ENOUGH SUN TO REACH WARMER LATE DAY HIGHS OUT WEST. GIVEN
CLOUDIER TRENDS...LOWERED HIGHS A CAT OR SO WEST AND LEFT THE EAST
CLOSER TO THE COOLER MAV MOS AT THIS POINT.
WAVE PASSES TONIGHT WITH MOST EVENING CONVECTION LIKELY OVER THE
SOUTH AND EAST UNDER THE EXITING LOBE OF DEEPER MOISTURE. HOWEVER
UPSLOPE FLOW ACROSS THE NW ENOUGH TO KEEP SOME ISOLATED SHRA GOING
THERE OVERNIGHT WITH ONLY ISOLATED RESIDUAL -SHRA POSSIBLE ELSW
AFTER MIDNIGHT UNDER NW FLOW ALOFT AND LACK OF ADDED FOCUS. WILL
STILL BE WARM/MUGGY AS EXPECT MOIST DEWPOINTS AND CLOUDS TO HOLD
LOWS UP CLOSER TO THE 68-73 RANGE OVERALL.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 235 AM EDT SATURDAY...
AN UPPER LEVEL RIDGE WILL REMAIN OVER THE ARKLATEX REGION THROUGH
EARLY NEXT WEEK. THE POSITION OF THIS RIDGE MAY SEND A FEW
DISTURBANCES OUR WAY FROM THE MIDWEST...BUT THAT HAS YET TO BE SEEN
WITH THE LATEST MODELS. MODELS SUGGESTING A PULSE STORM ENVIRONMENT
WITH STORMS INITIATING OVER THE MOUNTAINS IN THE AFTERNOON...DRIFTING
EAST TO A LEE TROUGH OVER THE PIEDMONT IN THE EVENING. MODELS ARE A
LITTLE SLOWER WITH A COLD FRONT ENTERING THE OHIO VALLEY MONDAY.
THEREFORE WILL SLOW THE ARRIVAL OF ANY PREFRONTAL CONVECTION
ENTERING THE AREA UNTIL LATE MONDAY NIGHT-TUESDAY.
OUTSIDE OF SOME SCATTERED THUNDERSTORMS EACH AFTERNOON...THE HEAT
WILL BE THE MAIN TOPIC OF WEATHER CONVERSATIONS. TEMPERATURES SUNDAY
AND MONDAY AFTERNOON WILL RUN AROUND 5F WARMER THAN NORMAL...WITH
UPPER 80S WEST TO THE LOW TO MID 90S EAST. DEW POINTS WILL ALSO RUN
WARM AND IN THE UPPER 60S TO LOWER 70S. APPARENT TEMPERATURES...FOR
AT LEAST A FEW HOURS EACH AFTERNOON...WILL FEEL LIKE THE LOWER 90S
ACROSS THE MOUNTAINS AND AROUND 98F-103F ACROSS THE FOOTHILLS AND
PIEDMONT COUNTIES OF NW NC/SW VA.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 330 PM EDT FRIDAY...
EXPECT TO START TUESDAY MORNING WITH THE FRONT DRAPED AROUND OUR
AREA. LOW PRESSURE ARRIVING FROM THE WEST DURING THE AFTERNOON AND
EVENING WILL TRIGGER MORE SCATTERED SHOWER AND THUNDERSTORM ACTIVITY
FOR THE AFTERNOON AND EVENING. PASSAGE OF THE LOW ACROSS OUR AREA
WILL HELP PUSH THE FRONT INTO THE CAROLINAS TUESDAY NIGHT.
UPPER LEVEL WINDFLOW WILL TRANSITION TO A WEAK WEST TO EAST PATTERN
FOR THE MIDDLE OF NEXT WEEK...BRINGING A SERIES OF SUBTLE
DISTURBANCES ACROSS THE MID ATLANTIC. AS SUCH...EXPECT A CHANCE OF
SHOWERS AND THUNDERSTORMS EACH DAY...MAINLY THOSE WHICH DEVELOP WITH
DAYTIME HEATING. TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
AS OF 101 AM EDT SATURDAY...
VFR ACROSS THE REGION WILL GRADUALLY GIVE WAY TO LOWERING CIGS
OVER THE WESTERN MOUNTAINS OVERNIGHT AND ALONG THE BLUE RIDGE
PRIOR TO DAYBREAK. LEADING OUTFLOW DRIVEN SHRA/TSRA MAY PUSH INTO
THE KBLF/KLWB CORRIDOR PRIOR TO DAWN WITH MVFR CIGS AND POSSIBLY A
PERIOD OF MVFR/IFR VSBYS PENDING HOW FAR EAST ANY OF THE RESIDUAL
CONVECTION MAKES IT. SOME OF THESE SHOWERS MAY ALSO WORK OUT TO
KBCB AND KROA. THUS INCLUDED A TEMPO GROUP AT KBLF/KLWB FOR LOWER
VSBYS/CIGS WITHIN SHRA/TSRA...AND ADDED A VCSH FARTHER EAST TO
THE BLUE RIDGE IN LINE WITH THE LATEST HRRR OUTPUT.
SOME OF THESE WEAKENING SHOWERS MAY PUSH INTO EASTERN SECTIONS
SATURDAY MORNING WITH PLENTY OF DEBRIS CLOUDS MAKING FOR LINGERING
LOW END VFR TO MVFR CIGS OVER THE WEST THROUGH MIDDAY SATURDAY.
SHOULD FINALLY SEE A RETURN TO VFR FOR A WHILE SATURDAY AFTERNOON
AS HEATING WINS OUT WITH THE BEST THREAT FOR ADDED CONVECTION IN
THE LEE OF THE RIDGES AS THE REMNANT WAVE HEADS EAST AND COMBINES
WITH AFTERNOON HEATING. EXPECT CIGS BY LATE MORNING TO BE IN THE
MID DECK/AC AREA...WITH SCT TO BKN CU FORMING IN THE AFTERNOON
AROUND 4-5KFT. KEPT VCTS AT KROA/KLYH/KDAN WHERE POPS ARE HIGHEST
AND ADDED IN AT KBLF AROUND 19Z AND BEYOND GIVEN POTENTIAL FOR
HEATING TO REBOUND BEHIND THE EARLY CLOUD SHIELD/SHRA.
EXTENDED AVIATION DISCUSSION...
SUNDAY APPEARS TO BRING A MINIMUM IN CONVECTION WITH SHORT WAVE
RIDGING. MONDAY SHOULD SEE AN INCREASE IN CONVECTION
AGAIN...POTENTIALLY LINGERING INTO TUESDAY WITH WAVES OF LOW
PRESSURE RIDING THROUGH THE REGION IN A WEST TO WEST- NORTHWEST
FLOW. BOUNDARY MAY PUSH FAR ENOUGH SOUTH IN THE WAKE OF THE
CONVECTION TO BRING MAINLY VFR WITH ONLY ISOLATED
AFTERNOON/EVENING SHRA/TSRA ACROSS THE SOUTH ON WEDNESDAY.
OUTSIDE SHRA/TSRA AND EARLY MORNING FOG/LOW CLOUDS...GENERALLY
VFR CONDITIONS EXPECTED THROUGH MUCH OF THE PERIOD.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/RAB/WP
NEAR TERM...JH
SHORT TERM...RCS
LONG TERM...AMS/NF
AVIATION...JH/JR/RAB/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
112 AM EDT SAT JUL 18 2015
.SYNOPSIS...
A WEAK TROUGH OF LOW PRESSURE WILL CROSS THE MOUNTAINS FROM THE
WEST THIS MORNING BEFORE EXITING THE PIEDMONT LATER SATURDAY
AFTERNOON. ANOTHER WEAK FRONT WILL DRIFT INTO THE REGION FROM THE
NORTHWEST BY MONDAY...STALLING NEAR US AS WEAK WAVES OF LOW
PRESSURE RIDE ALONG THE BOUNDARY THROUGH THE FIRST HALF OF NEXT
WEEK. THIS WILL CONTINUE TO RESULT IN WARM AND HUMID CONDITIONS
THROUGH THE PERIOD.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 920 PM EDT FRIDAY...
00Z RNK SOUNDING SHOWING AMPLE SBCAPE OF 3200 J/KG...BUT LACKING
MOISTURE AND TRIGGERING MECHANISM. ATTM...RADAR IS CLEAR EXCEPT
FOR A LEADING EDGE OF SHOWERS/STORMS FROM UPSTREAM CONVECTION
MOVING TOWARD HTS WV. A THETA-E RIDGE PROTRUDES TOWARD THE
GREENBRIER VALLEY THIS EVENING SOME MOISTURE CONVERGENCE...SO KEPT
SLIGHT CHANCE IN THIS AREA TIL MIDNIGHT THEN SHOULD GRADUALLY SEE
THE UPSTREAM SHOWERS AND STORMS MOVE INTO THE MTNS AFTER
MIDNIGHT...BUT IN A WEAKENED STATE.
THE TEMPS AND DEWPOINTS REMAIN ELEVATED...AND LOWS TONIGHT ON
TRACK FOR MID 60S MTNS TO LOWER 70S PIEDMONT...AS CLOUDS INCREASE
OVERNIGHT.
PREVIOUS DISCUSSION ISSUED EARLIER THIS AFTERNOON...
MAIN FOCUS THROUGH THIS PERIOD WILL BE ON A SHORT WAVE...CURRENTLY
MOVING THROUGH THE GREAT LAKES. THE MAIN DYNAMICS FROM THIS SYSTEM
WILL TRACK TO OUR NORTHEAST AS A BROAD UPPER RIDGE REMAINS ACROSS
THE ENTIRE SOUTHERN U.S. HOWEVER...THUNDERSTORMS DEVELOPING ACROSS
IN/OH THIS AFTERNOON HAVE THE POTENTIAL TO DRIFT SOUTHEAST
OVERNIGHT...AS INDICATED BY SEVERAL OF THE SYNOPTIC-SCALE MODELS.
THE MESO-SCALE MODELS ARE IN LESS AGREEMENT ABOUT THIS...HINGING
MORE ON DIURNAL DEVELOPMENT ACROSS THE MOUNTAINS...WHICH AS OF
THIS WRITING HAS FAILED TO MATERIALIZE. THE SOLUTION PRESENTED BY
THE GFS...AND SEVERAL OF THE SYNOPTIC MODELS...SEEMS PLAUSIBLE
GIVEN THE PATTERN AND RECENT TREND OF THIS IN RECENT WEEKS.
THEREFORE...CURRENT THINKING IS THAT A REMNANT MCS/CONVECTIVE
COMPLEX WILL DRIFT INTO THE WV MOUNTAINS AFTER MIDNIGHT...THEN
DIMINISH AS IT ATTEMPTS TO CROSS THE MOUNTAINS. NOT REALLY
EXPECTING MUCH MORE THAN A FEW LIGHT SHOWERS TO MAKE IT EAST OF
THE MOUNTAINS AND MOST LIGHTNING/THUNDER SHOULD BE GONE BY THE
11Z-12Z TIME FRAME.
SATURDAYS FORECAST DEPENDS LARGELY ON THE ABOVE SCENARIO UNFOLDING
AS EXPECTED. CONSIDERABLE CONVECTIVE CLOUD DEBRIS AND EVEN LIGHT
SHOWERS SHOULD BE LINGERING AT DAYBREAK AND SHORTLY THEREAFTER
ACROSS THE WESTERN PART OF THE CWA...WEST OF THE BLUE RIDGE. THIS
CLOUD COVER...COMBINED WITH THE BETTER UPPER-LEVEL DYNAMICS
SHIFTING INTO THE PIEDMONT/NC AREA BY AFTERNOON...SHOULD LEAVE THE
NORTHWEST HALF OF THE CWA CLOUDY AND MAINLY CONVECTIVE FREE
THROUGH MUCH OF THE DAY UNTIL PERHAPS ISOLATED DIURNAL ACTIVITY
DEVELOPS ACROSS THE MOUNTAINS LATER IN THE DAY. HOWEVER...EAST AND
SOUTH OF THE BLUE RIDGE...WOULD EXPECT MORE WIDESPREAD CONVECTION
TO DEVELOP FROM DIFFERENTIAL HEATING ON THE EDGE OF MORNING CLOUD
DEBRIS...AND IN AN AREA OF BETTER HEATING AND INSTABILITY. THERE
COULD POSSIBLE EVEN BE A FEW STRONG TO SEVERE THUNDERSTORMS IN
THIS AREA DURING THE AFTERNOON...BUT CONFIDENCE IS LOW IN THIS AND
SPC DOES NOT CURRENTLY HAVE ANY AREA HIGHLIGHTED FOR SUCH. ONLY
SLIGHTLY BETTER THAN A PULSE-TYPE THUNDERSTORM ENVIRONMENT. ANY
CONVECTION WILL DRIFT SOUTH OF THE CWA SHORTLY AFTER SUNSET.
TEMPERATURES WILL BE MOSTLY ABOVE NORMAL THROUGH THE PERIOD.
CONSIDERABLE CLOUD COVER TONIGHT WILL LIMIT COOLING WEST AND
LIKELY RADIATIONAL FOG AS WELL. WESTERN AREAS MAY REMAIN A TAD
COOLER SATURDAY THAN TODAY BECAUSE OF CLOUD COVER...BUT LATE
AFTERNOON BREAKS COULD ALLOW TEMPERATURES TO RECOVER FAIRLY
QUICKLY. 850MB TEMPS HOVER NEAR +20C...OF SLIGHTLY HIGHER
PIEDMONT...SO THERE IS LITTLE COOLING TO BE HAD OTHER THAN CLOUDS
AND PRECIPITATION.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
AS OF 300 PM EDT FRIDAY...
SUBTROPICAL RIDGING OVER THE WESTERN GULF COAST REGION WILL BUILD
EAST THROUGH THE PERIOD...WHILE SOUTHWESTERLY WINDFLOW IN THE LOW
LEVELS WILL CONTINUE TO DRAW WARM HUMID AIR UP THE APPALACHIAN
CHAIN. AS SUCH...WE CAN EXPECT TEMPERATURES FOR SUNDAY AND MONDAY TO
BE SOME OF THE WARMEST OUR AREA HAS EXPERIENCED THIS SUMMER AS
AFTERNOON HIGHS RANGE FROM THE MID/UPPER 80S ACROSS THE MOUNTAINS...
TO THE LOW/MID 90S ACROSS THE PIEDMONT...PERHAPS A FEW UPPER 90S
ACROSS THE SOUTHSIDE. THESE TEMPERATURES WILL PUSH HEAT INDICES INTO
THE 100F TO 105F RANGE BOTH DAY EAST OF A DANVILLE TO LYNCHBURG
LINE...AND WE MAY BE ISSUING OUR FIRST HEAT ADVISORIES OF THE
YEAR. OVERNIGHTS WILL BE ON THE WARM AND MUGGY SIDE...WITH LOWS
RANGING FROM THE MID 60S TO THE LOW 70S AREAWIDE.
NOT MUCH SUPPORT FOR MORE THAN SPOTTY SHOWER AND THUNDERSTORM
ACTIVITY FOR SUNDAY...MAINLY ACROSS THE MOUNTAINS DURING THE
AFTERNOON AND EARLY EVENING...BUT PERHAPS WITH A FEW STORMS DRIFTING
ACROSS THE PIEDMONT BEFORE SUNSET. INSTABILITY WILL REMAIN
MARGINAL...WITH CAPES RISING TO AROUND ~1500 J/KG...WHICH WILL
SUPPORT A FEW STRONG STORMS.
EXPECT MORE WIDESPREAD CONVECTION ON MONDAY HOWEVER DUE TO STRONGER
SURFACE CONVERGENCE AS A COLD FRONT SINKS SOUTH TOWARD OUR AREA.
UPPER LEVEL WINDS REMAIN WEAK...BUT WITH DEEPER MOISTURE POOLING
ACROSS OUR AREA AHEAD OF THE FRONT PUSHING PRECIPITABLE WATER VALUES
TO THE 1.5 TO 1.8 INCH RANGE FOR OUR AREA...LOOKING AT BETTER
CHANCES FOR PRECIPITATION LOADING TO ENHANCE THUNDERSTORMS
DOWNDRAFTS. COMBINE THAT WITH CAPES EXCEEDING 2000 J/KG...AND ITS
LOOKING LIKE A DECENT CHANCE FOR SOME STORMS TO BECOME SEVERE. THE
COLD FRONT WILL CONTINUE TO SINK SOUTH INTO THE EVENING...EVENTUALLY
SETTLING SOMEWHERE OVER OR AROUND OUR AREA BY DAWN TUESDAY.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 330 PM EDT FRIDAY...
EXPECT TO START TUESDAY MORNING WITH THE FRONT DRAPED AROUND OUR
AREA. LOW PRESSURE ARRIVING FROM THE WEST DURING THE AFTERNOON AND
EVENING WILL TRIGGER MORE SCATTERED SHOWER AND THUNDERSTORM ACTIVITY
FOR THE AFTERNOON AND EVENING. PASSAGE OF THE LOW ACROSS OUR AREA
WILL HELP PUSH THE FRONT INTO THE CAROLINAS TUESDAY NIGHT.
UPPER LEVEL WINDFLOW WILL TRANSITION TO A WEAK WEST TO EAST PATTERN
FOR THE MIDDLE OF NEXT WEEK...BRINGING A SERIES OF SUBTLE
DISTURBANCES ACROSS THE MID ATLANTIC. AS SUCH...EXPECT A CHANCE OF
SHOWERS AND THUNDERSTORMS EACH DAY...MAINLY THOSE WHICH DEVELOP WITH
DAYTIME HEATING. TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 101 AM EDT SATURDAY...
VFR ACROSS THE REGION WILL GRADUALLY GIVE WAY TO LOWERING CIGS
OVER THE WESTERN MOUNTAINS OVERNIGHT AND ALONG THE BLUE RIDGE
PRIOR TO DAYBREAK. LEADING OUTFLOW DRIVEN SHRA/TSRA MAY PUSH INTO
THE KBLF/KLWB CORRIDOR PRIOR TO DAWN WITH MVFR CIGS AND POSSIBLY A
PERIOD OF MVFR/IFR VSBYS PENDING HOW FAR EAST ANY OF THE RESIDUAL
CONVECTION MAKES IT. SOME OF THESE SHOWERS MAY ALSO WORK OUT TO
KBCB AND KROA. THUS INCLUDED A TEMPO GROUP AT KBLF/KLWB FOR LOWER
VSBYS/CIGS WITHIN SHRA/TSRA...AND ADDED A VCSH FARTHER EAST TO
THE BLUE RIDGE IN LINE WITH THE LATEST HRRR OUTPUT.
SOME OF THESE WEAKENING SHOWERS MAY PUSH INTO EASTERN SECTIONS
SATURDAY MORNING WITH PLENTY OF DEBRIS CLOUDS MAKING FOR LINGERING
LOW END VFR TO MVFR CIGS OVER THE WEST THROUGH MIDDAY SATURDAY.
SHOULD FINALLY SEE A RETURN TO VFR FOR A WHILE SATURDAY AFTERNOON
AS HEATING WINS OUT WITH THE BEST THREAT FOR ADDED CONVECTION IN
THE LEE OF THE RIDGES AS THE REMNANT WAVE HEADS EAST AND COMBINES
WITH AFTERNOON HEATING. EXPECT CIGS BY LATE MORNING TO BE IN THE
MID DECK/AC AREA...WITH SCT TO BKN CU FORMING IN THE AFTERNOON
AROUND 4-5KFT. KEPT VCTS AT KROA/KLYH/KDAN WHERE POPS ARE HIGHEST
AND ADDED IN AT KBLF AROUND 19Z AND BEYOND GIVEN POTENTIAL FOR
HEATING TO REBOUND BEHIND THE EARLY CLOUD SHIELD/SHRA.
EXTENDED AVIATION DISCUSSION...
SUNDAY APPEARS TO BRING A MINIMUM IN CONVECTION WITH SHORT WAVE
RIDGING. MONDAY SHOULD SEE AN INCREASE IN CONVECTION
AGAIN...POTENTIALLY LINGERING INTO TUESDAY WITH WAVES OF LOW
PRESSURE RIDING THROUGH THE REGION IN A WEST TO WEST- NORTHWEST
FLOW. BOUNDARY MAY PUSH FAR ENOUGH SOUTH IN THE WAKE OF THE
CONVECTION TO BRING MAINLY VFR WITH ONLY ISOLATED
AFTERNOON/EVENING SHRA/TSRA ACROSS THE SOUTH ON WEDNESDAY.
OUTSIDE SHRA/TSRA AND EARLY MORNING FOG/LOW CLOUDS...GENERALLY
VFR CONDITIONS EXPECTED THROUGH MUCH OF THE PERIOD.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/RAB/WP
NEAR TERM...RAB/WP
SHORT TERM...NF
LONG TERM...AMS/NF
AVIATION...JH/JR/RAB/WP
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
253 PM CDT SAT JUL 18 2015
.TONIGHT AND SUNDAY - CONFIDENCE...MEDIUM.
THE LAST OF A SMALL MCS WILL MOVE THROUGH THE FORECAST AREA THIS
EVENING. THE 18.18Z HRRR IS SHOWING DRY CONDITIONS OVERNIGHT ONCE
THIS MCS MOVES OUT. A COLD FRONT IS EXPECTED TO MOVE THROUGH THE
AREA OVERNIGHT AND INTO THE EARLY MORNING HOURS SUNDAY. WINDS WILL
VEER TO A MORE WESTERLY DIRECTION OVERNIGHT AND FROM THE NORTHWEST
BY DAWN. WINDS WILL BE A LITTLE GUSTY AS WINDS REMAIN FROM THE SOUTH
AHEAD OF THE COLD FRONT BOUNDARY. THE COLD FRONT COULD SPARK A
THUNDERSTORM OR TWO AS IT SWINGS THROUGH THE AREA OVERNIGHT...SO
KEPT SLIGHT CHANCE POPS FOR NOW. RAIN CHANCES WILL BE GONE BY LATER
SUNDAY MORNING. EXPECT DRIER CONDITIONS FOR SUNDAY...ALONG WITH
SLOWLY CLEARING SKIES.
.SUNDAY NIGHT...FORECAST CONFIDENCE IS HIGH.
DRY WITH HIGH PRESSURE BRIEFLY MOVING THROUGH. LOWS SHOULD FEEL
MORE REFRESHING THAN WHAT WE/VE SEEN OVER THE PAST FEW NIGHT.
.MONDAY INTO MONDAY NIGHT...FORECAST CONFIDENCE IS
A COLD FRONT WILL DROP IN QUICKLY MONDAY AFTERNOON AND EVENING.
MOISTURE WILL STREAM NORTH AHEAD OF THE FRONT...BUT THE NAM IS
BEING TOO AGGRESSIVE AS USUAL. FOR NOW WILL CARRY CHCY POPS WITH
THIS POSITIVE TILT SYSTEM.
.TUESDAY THROUGH WEDNESDAY NIGHT...FORECAST CONFIDENCE IS HIGH.
REFRESHING HIGH PRESSURE BUILDS IN WITH NOTICEABLY LOWER DEW
POINTS AND NEAR NORMAL TEMPERATURES. LOOKS DRY THIS PERIOD.
.THURSDAY THROUGH SATURDAY...FORECAST CONFIDENCE IS MEDIUM.
A SLOW MOVING TROUGH OF LOW PRESSURE WILL PUSH INTO THE REGION BY
THE END OF NEXT WEEK RAISING A SMALL THREAT...AT LEAST AT THIS
TIME...FOR SHOWERS AND A FEW THUNDERSTORMS. THERE IS PLENTY OF
MODEL DISAGREEMENT SO STAY TUNED.
&&
.AVIATION/00Z TAFS/...
A LINE OF SHOWERS AND THUNDERSTORMS IS MOVING OFF TO THE EAST THIS
AFTERNOON...BRINGING HEAVY RAINS AND REDUCED CIGS AND VSBYS. THIS
LINE WILL AFFECT THE MKE AND ENW TAF SITES LATER THIS AFTERNOON.
CONDITIONS COULD QUICKLY CHANGE FROM VFR TO MVFR AS THIS LINE MOVES
THROUGH. THINGS SHOULD DRY UP ONCE THIS LINE OF STORMS MOVES OUT.
EXPECT WINDS TO SLOWLY VEER OVERNIGHT TO A MORE WESTERLY DIRECTION
AHEAD OF A COLD FRONT EXPECTED TO MOVE THROUGH TONIGHT. AN ISOLATED
THUNDERSTORM IS POSSIBLE TONIGHT AS THIS COLD FRONT MOVES THROUGH.
&&
.MARINE...
A LINE OF THUNDERSTORMS WILL MOVE THROUGH THE NEARSHORE WATERS THIS
AFTERNOON. WINDS COULD BE GUSTY BETWEEN 25 AND 35 KTS AS THIS LINE
MOVES THROUGH. A COLD FRONT WILL SWING THROUGH THE REGION TONIGHT
AND BRING WINDS AROUND TO THE WEST AND NORTHWEST THROUGH THE REST OF
THE WEEKEND.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TONIGHT/SUNDAY AND AVIATION/MARINE...JTS
SUNDAY NIGHT THROUGH SATURDAY...DAVIS
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1105 AM CDT SAT JUL 18 2015
.UPDATE...
CONTINUED THE HEAT ADVISORY AS IS FOR NOW...FROM NOON UNTIL 8 PM
TODAY ACROSS MOST OF THE AREA. SHOULD GET ENOUGH SUN TO GET HIGHS
TO AROUND 90 DEGREES. DEW POINTS SHOULD ALSO RECOVER INTO THE
LOWER TO MID 70S AT LEAST...WHICH GIVES HEAT INDEX VALUES AROUND
100 DEGREES. ONE CONCERN IS POSSIBLE CONVECTION AND ASSOCIATED
CLOUDS...WHICH WOULD LIMIT HEATING THIS AFTERNOON. ANOTHER CONCERN
IS ONSHORE WINDS LINGERING THIS AFTERNOON NEAR THE LAKE FROM
MILWAUKEE SOUTHWARD...WHICH WOULD LIMIT HIGHS THERE.
A FEW CELLS ARE DEVELOPING IN GRANT COUNTY...AHEAD OF ADVANCING
500 MB VORTICITY MAXIMUM IN NORTHEAST IOWA. THIS FEATURE IS
EXPECTED TO PUSH EAST THROUGH THE AREA THIS AFTERNOON. IN
ADDITION...OUTFLOW BOUNDARY FROM EARLY MORNING STORMS LIES FROM
THE CHICAGO AREA INTO SOUTHERN GRANT COUNTY. COMBINATION OF
OUTFLOW BOUNDARY AND ADVANCING VORTICITY MAXIMUM MAY HELP GENERATE
MORE CELLS OVER THE NEXT HOUR OR TWO.
HRRR MODEL TAKES THESE INITIAL CELLS AND DEVELOPS AN AREA OF
STRONG CONVECTION AS IT MOVES EAST ACROSS THE AREA THIS AFTERNOON.
ONCE CONVECTIVE INHIBITION IS OVERCOME BY EARLY AFTERNOON...SHOULD
SEE STRONG/SEVERE CONVECTION DEVELOP GIVEN STRONG MEAN LAYER CAPE
AND DEEP LAYER SHEAR VALUES. LARGE HAIL AND DAMAGING WINDS WOULD
BE THE MAIN HAZARDS. ANY TORNADO RISK WOULD BE TIED TO THE OUTFLOW
BOUNDARY LOCATION...WHICH AT THIS TIME LOOKS TO REMAIN SOUTH OF
THE AREA.
WILL UPDATE POPS TO REFLECT AFTERNOON TIMING WITH STORMS...WHICH
SHOULD EXIT THE EAST BY AROUND 00Z SUNDAY.
&&
.AVIATION/18Z TAFS/...
POSSIBLE STRONG/SEVERE STORMS MAY PUSH EAST ACROSS SOUTHERN
WISCONSIN THIS AFTERNOON. ALREADY SEEING DEVELOPMENT IN FAR
SOUTHWEST WISCONSIN...AND THIS MAY CONTINUE TO DEVELOP AND BECOME
STRONGER INTO THE AFTERNOON.
MADISON WOULD SEE BEST SHOT OF THIS BETWEEN 18Z AND 21Z
SATURDAY...AND THE EASTERN SITES BETWEEN 20Z SATURDAY AND 00Z
SUNDAY. IFR VISIBILITIES AND MVFR CEILINGS WOULD BE POSSIBLE IN
ANY STORMS...AS WELL AS LARGE HAIL AND STRONG WINDS.
VFR CONDITIONS ARE EXPECTED OTHERWISE THIS AFTERNOON INTO SUNDAY.
MODERATE SOUTH/SOUTHWEST WINDS ARE EXPECTED AT MADISON AND
WAUKESHA...WITH SOUTH/SOUTHEAST WINDS AT MILWAUKEE AND KENOSHA.
WINDS WILL SHIFT TO THE WEST NORTHWEST LATER TONIGHT AFTER COLD
FRONT MOVES THROUGH THE AREA...REMAINING SO ON SUNDAY. SOME
MIDDLE TO HIGH CLOUDS MAY LINGER LATER TONIGHT INTO SUNDAY.
&&
.MARINE...
SOUTH/SOUTHEAST WINDS MAY GUST TO AROUND 20 KNOTS THIS AFTERNOON.
NOT EXPECTING SMALL CRAFT ADVISORY LEVEL WAVES OR GUSTS AT THIS
TIME.
&&
.PREV DISCUSSION... /ISSUED 338 AM CDT SAT JUL 18 2015/
SHORT TERM...
TODAY AND TONIGHT- CONFIDENCE...MEDIUM.
AN ACTIVE WEATHER PATTERN IS EXPECTED FOR TODAY WITH THREE MAIN
FEATURES OF CONCERN.
THE FIRST BEING WITH THE CURRENT MCS ROLLING INTO WESTERN WISCONSIN
WHERE THERE IS A LONG HISTORY OF DAMAGING WINDS ASSOCIATED WITH
IT. THE MAIN UNCERTAINTY IS WITH HOW LONG IT WILL REMAIN AT SEVERE
LEVELS AS IT STARTS TO OUTRUN SOME OF THE BETTER LOW LEVEL
MOISTURE TRANSPORT WHICH IS ANGLED UP TOWARD SOUTHERN MINNESOTA.
18.08Z RAP ANALYSIS SHOWS A HIGHLY UNSTABLE ENVIRONMENT SITUATED
FROM SOUTHEAST MINNESOTA DOWN INTO SOUTHWEST WISCONSIN WHERE 0-3KM
MUCAPE IS AROUND 4000 J/KG. CURRENTLY...THE STRONGEST PART OF THE
LINE IS IN NORTHERN WISCONSIN WHERE THE MCV IS ALONG WITH A BETTER
REAR INFLOW JET...BUT AM EXPECTING THE SOUTHERN PORTION OF THE
LINE TO BE MAINTAINED AND RIDE ALONG THE INSTABILITY GRADIENT
THROUGH SOUTHERN WISCONSIN THIS MORNING. WHETHER IT WILL BE SEVERE
OR NOT IS UNCERTAIN AS IT WILL BE LEAVING THE BETTER LOW LEVEL
MOISTURE TRANSPORT CHANNEL. TRENDS WILL CONTINUE TO BE MONITORED.
CLOUD COVER AND HOW FAST THE MCS MOVES OUT OF THE REGION PLAYS INTO
HOW HOT CONDITIONS WILL BE TODAY. THERE CURRENTLY IS AN EXPANSIVE
UPPER LEVEL CLOUD DECK BLOWING OFF OF THE MCS WHICH COULD SLOW HOW
FAST TEMPERATURES RISE THIS MORNING...PARTICULARLY IF WE HAVE SOME
RAIN MOVE THROUGH. STRONG SOUTHERLY LOW LEVEL FLOW IS EXPECTED TO
HELP CLEAR CONDITIONS OUT GOING INTO THIS AFTERNOON WHICH SHOULD
ALLOW TEMPERATURES TO RISE UP TO 90F OR ABOVE. SURFACE DEW POINTS
ARE ALREADY IN THE LOW 70S WITH THE AIR MASS TO THE SOUTH SHOWING
DEW POINTS IN THE MID TO UPPER 70S. THE EXPECTED COMBINATION OF
TEMPERATURES IN THE 90S AND DEW POINTS IN THE 70S ARE EXPECTED TO
PUSH HEAT INDICES INTO THE 100-104 DEGREE RANGE TODAY ACROSS MUCH OF
THE REGION. FDL AND WASHINGTON COUNTIES LOOK TO BE JUST AS WARM AS
COUNTIES TO THE WEST...SO HAVE ADDED THEM TO THE ADVISORY.
THE FOCUS THEN TURNS TO THE SEVERE POTENTIAL FOR THIS AFTERNOON AND
EVENING AS THE ENVIRONMENT RECHARGES AFTER THE MCS CLEARS. 18.00Z
NAM/GFS/RAP SOUNDINGS ALL SHOW A HIGHLY UNSTABLE/FAT CAPE PROFILE
AHEAD OF A COLD FRONT. THERE DOES APPEAR TO BE SOME WIND SHEAR AS
WELL...MAINLY IN THE LOWEST 3KM...BUT IT DOES EXTEND TO THE TOP
PORTIONS OF THE SOUNDING WHERE AN UPPER LEVEL JET STREAK WILL BE
PROPAGATING EAST INTO THE REGION. LARGE HAIL AND DAMAGING WINDS
LOOK TO BE THE MAIN THREATS DUE TO THE HIGH INSTABILITY/0-3KM
SHEAR...BUT THERE COULD BE A BOUNDARY LEFT OVER FROM THIS MORNINGS
MCS WHICH COULD BE A FOCUS FOR TORNADO DEVELOPMENT. 0-1KM SHEAR
WOULD LIKELY BE MAXIMIZED ALONG THIS BOUNDARY IF THE SOUTHERLY LOW
LEVEL FLOW DOES NOT WIPE IT OUT OR PUSH IT BACK TO THE NORTH.
SOUNDINGS ALSO ARE NOT LOOKING AS CAPPED AS PREVIOUSLY THOUGHT...SO
CONVECTION MAY INITIATE A BIT EARLIER IN THE AFTERNOON THAN
TYPICALLY WOULD OCCUR. THE MAIN WINDOW FOR SEVERE WEATHER APPEARS
TO BE FROM THIS AFTERNOON INTO THE EARLY EVENING HOURS.
SUNDAY... FORECAST CONFIDENCE HIGH.
THE COLD FRONT WILL LIKELY CLEAR SOUTHEAST WI BY MID SUNDAY MORNING.
IT IS A SMALL CHANCE... BUT THUNDERSTORMS COULD EITHER BE ONGOING OR
TRIGGERED BY THE FRONTAL PASSAGE AS IT MOVES THROUGH SOUTHERN WI
SUNDAY MORNING.
PLAN ON QUIET AND MORE COMFORTABLE WEATHER LATER SUNDAY AFTERNOON
AND NIGHT BEHIND THE FRONT. HIGH TEMPS WILL BE COOLER THAN THE
PREVIOUS TWO DAYS... ONLY IN THE LOWER 80S. DEWPOINTS WILL BE
STEADILY FALLING THROUGH THE AFTERNOON. WINDS WILL BE A LITTLE
BREEZY OUT OF THE NORTHWEST SUNDAY AFTERNOON.
LONG TERM...
MONDAY... FORECAST CONFIDENCE MEDIUM.
THE ECMWF AND GFS ARE NOW BRINGING CHANCES FOR SHOWERS AND
THUNDERSTORMS INTO CENTRAL AND SOUTHERN WI MONDAY AFTERNOON AND
NIGHT. THIS IS DUE TO A SHORTWAVE TROUGH AND RIGHT ENTRANCE REGION
OF AN UPPER JET. A COLD FRONT WILL SLIDE SOUTH THROUGH WI LATE
MONDAY NIGHT. THESE FEATURES ARRIVE EARLIER THAN PREVIOUS FORECASTS.
TUESDAY THROUGH FRIDAY... FORECAST CONFIDENCE MEDIUM.
HIGH PRESSURE WILL SET UP OVER THE GREAT LAKES REGION FOR MUCH OF
NEXT WEEK. DRY AIR IN PLACE WILL MAKE IT DIFFICULT FOR ANY
SHORTWAVES CROSSING THE AREA TO PRODUCE PRECIP. THE GFS AND ECMWF HAVE
BACKED OFF ON QPF FOR SOUTHERN WI ON WED THROUGH FRI. EXPECT POPS
TO BE CUT BACK IN LATER FORECASTS. THE NEXT REAL CHANCE FOR PRECIP
NOW LOOKS LIKE SATURDAY.
TEMPERATURES WILL REMAIN AROUND NORMAL WITH HIGHS AROUND 80.
AVIATION/12Z TAFS/...
THE MAIN FOCUS AT THE TAF SITES IS WITH TWO POSSIBLE ROUNDS OF
CONVECTION...ONE POSSIBLY COMING THIS MORNING WITH ANOTHER ROUND
POSSIBLE THIS AFTERNOON/EVENING. A LINE OF STORMS CURRENTLY IN WEST
CENTRAL WISCONSIN IS EXPECTED TO TRACK EAST SOUTHEAST THIS MORNING
AND COULD ROLL THROUGH THE REGION AND BRING SOME STRONG WINDS AND
LOW VISIBILITIES ALONG WITH IT. AFTER THAT SYSTEM MOVES
THROUGH...SOUTHERLY WINDS WILL PICK UP DURING THE DAY AS A HOT AND
HUMID AIR MASS CREATES A VERY UNSTABLE ATMOSPHERE FOR THIS AFTERNOON
AND EVENING. ANOTHER ROUND OF STORMS SHOULD DEVELOP AHEAD OF A COLD
FRONT WHICH WILL PUSH THROUGH THIS EVENING. STRONG WINDS AND LOW
VISIBILITY WILL AGAIN BE POSSIBLE WITH THIS ROUND OF STORMS.
MARINE...
TWO ROUNDS OF STORMS MAY AFFECT THE NEARSHORE WATERS OF LAKE
MICHIGAN THIS MORNING AND THEN AGAIN THIS AFTERNOON AND EARLY
EVENING. WINDS WILL BE ON THE INCREASE INTO THIS AFTERNOON OUT OF
THE SOUTH WITH SOME GUSTS POSSIBLY REACHING THE 20 TO 25 KT RANGE.
A COLD FRONT WILL SWING THROUGH THE REGION TONIGHT AND BRING WINDS
AROUND TO THE WEST NORTHWEST THROUGH THE REST OF THE WEEKEND.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR WIZ046-047-051-
056>059-062>072.
LM...NONE.
&&
$$
UPDATE...WOOD
TODAY/TONIGHT AND AVIATION/MARINE...HALBACH
SUNDAY THROUGH FRIDAY...MRC
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1238 PM MDT SAT JUL 18 2015
.UPDATE...
ISSUED AT 1058 AM MDT SAT JUL 18 2015
FORECAST PRETTY WELL ON TRACK FOR TODAY. MADE SOME MINOR
ADJUSTMENTS TO DECREASE CLOUD COVER SOMEWHAT THIS MORNING AND
EARLY AFTERNOON IN THE EASTERN FORECAST AREA. THE OTHER SMALL
CHANGE WAS TO INCREASE CHANCES FOR THUNDERSTORMS IN FAR SOUTHEAST
WYOMING AND INTO THE NEBRASKA PANHANDLE. INCREASING CONFIDENCE FOR
THE DEVELOPMENT OF THUNDERSTORMS OVER THE HIGHER TERRAIN OF
SOUTHEAST WYOMING BY EARLY THIS AFTERNOON WITH THUNDERSTORMS
INCREASING IN COVERAGE WHILE QUICKLY MOVING EASTWARD.
NUMERICAL MODELS DO HAVE SUBSTANTIAL DIFFERENCES IN THE
PROGRESSION OF THUNDERSTORM ACTIVITY TODAY. TENDED TO LEAN TOWARD
THE HRRR WITH THE FASTER TIMING. THE MAIN REASONS FOR GOING CLOSER
TO THE HRRR IS DUE TO THE STRONG WESTERLY FLOW ALOFT. CAPE VALUES
AROUND 1500 J/KG WILL NOT SUPPORT UPDRAFTS STRONG ENOUGH TO
OVERCOME THE OVERALL SHEAR...SUCH THAT STORMS SHOULD BECOME
OUTFLOW DOMINATE AND MOVE RAPIDLY TO THE EAST. ALTHOUGH THE FIRST
FEW THUNDERSTORMS MAY HAVE SOME SUPERCELL CHARACTERISTICS WITH
LARGE HAIL POSSIBLE...MORE CONCERNED ABOUT THE WIND THREAT TODAY.
STORM MOVEMENT SHOULD BE AROUND 40 MPH AND WHEN COMBINED WITH
STORM RELATIVE WINDS...WOULD NOT BE SURPRISED TO SEE WINDS TO
AROUND 70 MPH INTO THE PLAINS.
MAY SEE A LINE OF THUNDERSTORMS DEVELOP WITH A SQUALL LINE MOVING
OUT OF FAR SOUTHEAST WYOMING INTO THE NEBRASKA BY EARLY THIS
EVENING. THERE IS STILL SOME QUESTION AS TO WHERE A NEARLY
STATIONARY BOUNDARY WILL BE LOCATED THIS AFTERNOON. CURRENTLY IT
LOOKS LIKE IT WILL BE LINED UP ALONG OR JUST NORTH OF INTERSTATE
80 BETWEEN CHEYENNE AND SIDNEY. ALTHOUGH WINDS LOOK TO BE THE MAIN
SEVERE CONCERN TODAY...A SUPERCELL COULD OCCUR WITHIN OR AHEAD OF
ANY SQUALL LINE ON THE STATIONARY BOUNDARY. ANY SUPERCELL WOULD
HAVE AN INCREASED HAIL POTENTIAL AND A REMOTE POTENTIAL FOR
TORNADIC DEVELOPMENT. LCLS ALONG THE FRONT WILL BE BETWEEN
AROUND 4000 FEET SUCH THAT A TORNADO IS POSSIBLE BUT OVERALL
THREAT IS MINIMAL.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 237 AM MDT SAT JUL 18 2015
PREDAWN WATER VAPOR SATELLITE AND OBJECTIVE UPPER AIR ANALYSIS SHOWS
A VIGOROUS MID LEVEL SHORTWAVE TROUGH NOW TRACKING ACROSS EASTERN MT
INTO WESTERN ND. FARTHER WEST...A SEPARATE DISTURBANCE WAS DRIFTING
SOUTHEAST INTO THE GREAT BASIN. MOIST SOUTHWESTERLY FLOW ALOFT WILL
BECOME ESTABLISHED LATER TODAY ACROSS THE CENTRAL ROCKIES WITH GOOD
MONSOONAL MOISTURE STREAMING OVER THE CWA PER RECENT H7-H3 RH PROGS
FROM MOST GUIDANCE. RECENT SURFACE ANALYSIS DATA SHOWS A WEAK COOL
FRONT HAS ALREADY MOVED SOUTH INTO CO...SO EXPECT TEMPERATURES TODAY
TO BE COOLER THAN PREVIOUS DAYS. SFC FLOW SHOULD EVENTUALLY BEGIN TO
TURN MORE UPSLOPE ALONG/EAST OF THE LARAMIE RANGE IN THE AFTN...WITH
LLVL MOISTURE RAPIDLY INCREASING AS A RESULT. IN ADDITION...THE GFS
SHOWS A 100 KT H25 JET STREAK LIFTING INTO CENTRAL WY BY 00Z WITH A
LARGE PART OF THE CWA IN THE FAVORED RRQ. SCATTERED/NUMEROUS SHOWERS
AND TSTMS SHOULD BE THE NET RESULT. TENDENCY IS TO LEAN MORE TOWARD
THE NAM GIVEN THE RECENT DRY BIAS OF THE GFS WITH SURFACE DEW POINTS
5-10 DEGREES TOO LOW IN THE AFTN. DEW POINTS IN THE LOW-MID 50S AND
SURFACE TEMPS IN THE MID 70S YIELD SBCAPE OVER 1500 J/KG AS FAR WEST
AS CHEYENNE...WHICH COMBINED WITH 0 TO 6 KM VERTICAL SHEAR EXCEEDING
50 KTS WOULD SUGGEST SOME SEVERE POTENTIAL. PRIMARY AREA OF CONCERN
WOULD BE THE I80 CORRIDOR BETWEEN CYS-SNY. THE 06Z SPC DAY 1 OUTLOOK
HAS THIS REGION HIGHLIGHTED IN A SLGT RISK. INCREASING LLVL THETA-E
ADVECTION BETWEEN 00Z-06Z WOULD SUGGEST CONVECTION BECOMING FOCUSED
OVER THE SOUTHERN PANHANDLE...WITH THE THREAT TRANSITIONING TO VERY
HEAVY RAIN GIVEN NAM PWATS BETWEEN 1.5 AND 2.0 INCHES.
WHILE MODELS STILL DIFFER IN THE TIMING...THE GENERAL CONSENSUS IS
FOR THE AFOREMENTIONED TROUGH AXIS TO TRANSLATE EASTWARD ACROSS THE
CWA ON SUN. A PLUME OF MONSOONAL MOISTURE WILL REMAIN IN PLACE...SO
AT LEAST ISOLATED AFTERNOON CONVECTION CAN BE EXPECTED. THE 06Z NAM
IS COMING IN MORE BULLISH WITH QPF FIELDS...LIKELY DUE TO ENHANCED
LLVL CONVERGENCE VIA LEE TROUGHING AND LINGERING JET SUPPORT OVER
OUR NORTHERN ZONES. WE MAY NEED TO LOOK INTO BUMPING POPS INTO THE
SCATTERED CATEGORY IF THIS TREND CONTINUES. THIS COULD BE ANOTHER
OPPORTUNITY FOR STRONG/SEVERE STORMS EAST OF THE SFC TROUGH...IF
CLOUD COVER DOES NOT INHIBIT INSTABILITY. SPCS MARGINAL RISK LOOKS
GOOD FOR NOW. FOR MONDAY...THE MODELS ARE STILL HAVING A VERY HARD
TIME HANDLING SHORTWAVES WITHIN AN ACTIVE NORTHERN STREAM. GFS/ECM
CONTINUE TO ADVERTISE THE BATTLE OF TROUGH VS RIDGE...SO CONTINUED
TO KEEP LOW-END POPS OVER THE MOUNTAINS UNTIL WE CAN RESOLVE FINE
SCALE DETAILS.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY NIGHT)
ISSUED AT 310 AM MDT SAT JUL 18 2015
MEDIUM RANGE DETERMINISTIC MODELS CONTINUE TO STRUGGLE WITH
SHORTWAVE ENERGY MOVING EASTWARD EMBEDDED IN THE MEAN WESTERLY
FLOW ALOFT. THE GFS IS NOW MUCH MORE PROGRESSIVE WITH THE SECOND
SHORTWAVE FORECAST TO MOVE ACROSS WYOMING ON TUESDAY...WITH
ANOTHER ROUND OF SCATTERED SHOWERS AND TSTORMS MAINLY FOR THE
SOUTHERN TWO THIRDS OF THE FORECAST AREA. THE ECMWF AND GEM ARE
NEARLY 18 HOURS LATER WITH THIS SHORTWAVE AND DO NOT SHOW MUCH IN
THE WAY OF FORCING TUESDAY AND TUESDAY EVENING. THE ECMWF SHOWS
THIS SHORTWAVE CLIPPING THE AREA ON WEDNESDAY HOWEVER AS THE UPPER
LEVEL FLOW BEGINS TO VEER INTO THE NORTHWEST BEHIND THE WEAK UPPER
LEVEL TROUGH. KEPT POP BETWEEN 20 T0 40 PERCENT BOTH
DAYS...ESPECIALLY ALONG AND JUST NORTH OF THE I80 CORRIDOR. AT
THIS POINT...VERY DIFFICULT TO GET SPECIFIC FOR THE MIDDLE OF NEXT
WEEK. TEMPERATURES SHOULD TREND WARMER BY WEDNESDAY...BUT HIGHS
WILL BE NEAR OR SLIGHTLY BELOW NORMAL FOR THIS TIME OF THE YEAR.
BY THE END OF THE WEEK...MODELS SHOW A TYPICAL JULY WEATHER
PATTERN WITH VERY WARM TEMPERATURES AND RIDGING ALOFT EXTENDING
NORTHWARD ACROSS THE CENTRAL ROCKY MOUNTAINS. HIGH TEMPERATURES
IN THE MID 80S TO MID 90S ARE EXPECTED THROUGH THURSDAY AND
FRIDAY. CHANCES OF THUNDERSTORMS ARE UNCLEAR AT THIS TIME SINCE
MODELS IN THE LONG RANGE HAVE STRUGGLED WITH BOUNDARY LAYER
MOISTURE PROFILES THIS SUMMER. CAN NOT RULE OUT ISOLATED
THUNDERSTORMS ACROSS THE MOUNTAINS AND HIGH PLAINS AT THE VERY
LEAST...MAINLY DUE TO TRENDS THE LAST FEW MONTHS. THE GFS
ESPECIALLY HAS HAD THE TENDENCY TO SHOW A VERY DRY BOUNDARY LAYER
IN SOUTHWEST FLOW...SO WILL NOT PUT MUCH FAITH IN THIS SOLUTION AT
THIS TIME. DID INCREASE POP A BIT...BUT KEPT VALUES BELOW 15
PERCENT FOR NOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1224 PM MDT SAT JUL 18 2015
MAIN FORECAST CHALLENGE THIS TAF CYCLE IS TRYING TO PIN DOWN
THUNDERSTORM TIMING AND EXTENT THIS AFTERNOON. LATEST MODELS SHOW
CONVECTION INITIATING IN THE VICINTY OF KLAR AND KCYS BETWEEN
19-20Z WITH ADDL DEVELOPMENT THEREAFTER AS STORM MERGE ACROSS THE
ERN PLAINS. FOR NOW...CONFIDENCE IS THE GREATEST IN SEEING
THUNDERSTORM ACTIVITY AT KCYS SO INTRODUCED A TEMPO GROUP THERE
21-01Z. ELSEWHERE...KEPT VCTS MENTION AT MOST OTHER AIRFIELDS THIS
AFTERNOON AND EVEN AS THE ANTICIPATED THUNDERSTORM COMPLEX SHIFTS
EAST INTO WRN NEBRASKA. CONVECTION WILL DEPART W-E DURING THE
EVENING HOURS AND BE OUT OF THE AREA 04-06Z. THE OTHER CHANGE TO
THE FORECAST WAS TO INTRODUCE FOG POTENTIAL AT KCYS...KBFF AND
KSNY 10-15Z. CONFIDENCE IS NOT ALL THAT HIGH IN THIS
OCCURRING...BUT WANTED TO STEER THE TAFS THAT DIRECTION.
&&
.FIRE WEATHER...
ISSUED AT 237 AM MDT SAT JUL 18 2015
MINIMAL FIRE WEATHER CONCERNS. SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS WILL DEVELOP ACROSS SOUTHEAST WY AND THE WESTERN NE
PANHANDLE TODAY AND TONIGHT...YIELDING A GOOD CHANCE FOR WETTING
RAINS OVER MUCH OF THE AREA. GUSTY/ERRATIC WINDS COULD ACCOMPANY
SOME THUNDERSTORMS. OVERALL CONDITIONS SHOULD REMAIN NON-CRITICAL
THROUGH THE WEEKEND WITH AFTERNOON RH VALUES ABOVE 20 PCT. A TREND
TOWARD WARMER AND DRIER CONDITIONS IS EXPECTED NEXT WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...SML
SHORT TERM...CLH
LONG TERM...TJT
AVIATION...CAH
FIRE WEATHER...CLH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1058 AM MDT SAT JUL 18 2015
.UPDATE...
ISSUED AT 1058 AM MDT SAT JUL 18 2015
FORECAST PRETTY WELL ON TRACK FOR TODAY. MADE SOME MINOR
ADJUSTMENTS TO DECREASE CLOUD COVER SOMEWHAT THIS MORNING AND
EARLY AFTERNOON IN THE EASTERN FORECAST AREA. THE OTHER SMALL
CHANGE WAS TO INCREASE CHANCES FOR THUNDERSTORMS IN FAR SOUTHEAST
WYOMING AND INTO THE NEBRASKA PANHANDLE. INCREASING CONFIDENCE FOR
THE DEVELOPMENT OF THUNDERSTORMS OVER THE HIGHER TERRAIN OF
SOUTHEAST WYOMING BY EARLY THIS AFTERNOON WITH THUNDERSTORMS
INCREASING IN COVERAGE WHILE QUICKLY MOVING EASTWARD.
NUMERICAL MODELS DO HAVE SUBSTANTIAL DIFFERENCES IN THE
PROGRESSION OF THUNDERSTORM ACTIVITY TODAY. TENDED TO LEAN TOWARD
THE HRRR WITH THE FASTER TIMING. THE MAIN REASONS FOR GOING CLOSER
TO THE HRRR IS DUE TO THE STRONG WESTERLY FLOW ALOFT. CAPE VALUES
AROUND 1500 J/KG WILL NOT SUPPORT UPDRAFTS STRONG ENOUGH TO
OVERCOME THE OVERALL SHEAR...SUCH THAT STORMS SHOULD BECOME
OUTFLOW DOMINATE AND MOVE RAPIDLY TO THE EAST. ALTHOUGH THE FIRST
FEW THUNDERSTORMS MAY HAVE SOME SUPERCELL CHARACTERISTICS WITH
LARGE HAIL POSSIBLE...MORE CONCERNED ABOUT THE WIND THREAT TODAY.
STORM MOVEMENT SHOULD BE AROUND 40 MPH AND WHEN COMBINED WITH
STORM RELATIVE WINDS...WOULD NOT BE SURPRISED TO SEE WINDS TO
AROUND 70 MPH INTO THE PLAINS.
MAY SEE A LINE OF THUNDERSTORMS DEVELOP WITH A SQUALL LINE MOVING
OUT OF FAR SOUTHEAST WYOMING INTO THE NEBRASKA BY EARLY THIS
EVENING. THERE IS STILL SOME QUESTION AS TO WHERE A NEARLY
STATIONARY BOUNDARY WILL BE LOCATED THIS AFTERNOON. CURRENTLY IT
LOOKS LIKE IT WILL BE LINED UP ALONG OR JUST NORTH OF INTERSTATE
80 BETWEEN CHEYENNE AND SIDNEY. ALTHOUGH WINDS LOOK TO BE THE MAIN
SEVERE CONCERN TODAY...A SUPERCELL COULD OCCUR WITHIN OR AHEAD OF
ANY SQUALL LINE ON THE STATIONARY BOUNDARY. ANY SUPERCELL WOULD
HAVE AN INCREASED HAIL POTENTIAL AND A REMOTE POTENTIAL FOR
TORNADIC DEVELOPMENT. LCLS ALONG THE FRONT WILL BE BETWEEN
AROUND 4000 FEET SUCH THAT A TORNADO IS POSSIBLE BUT OVERALL
THREAT IS MINIMAL.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 237 AM MDT SAT JUL 18 2015
PREDAWN WATER VAPOR SATELLITE AND OBJECTIVE UPPER AIR ANALYSIS SHOWS
A VIGOROUS MID LEVEL SHORTWAVE TROUGH NOW TRACKING ACROSS EASTERN MT
INTO WESTERN ND. FARTHER WEST...A SEPARATE DISTURBANCE WAS DRIFTING
SOUTHEAST INTO THE GREAT BASIN. MOIST SOUTHWESTERLY FLOW ALOFT WILL
BECOME ESTABLISHED LATER TODAY ACROSS THE CENTRAL ROCKIES WITH GOOD
MONSOONAL MOISTURE STREAMING OVER THE CWA PER RECENT H7-H3 RH PROGS
FROM MOST GUIDANCE. RECENT SURFACE ANALYSIS DATA SHOWS A WEAK COOL
FRONT HAS ALREADY MOVED SOUTH INTO CO...SO EXPECT TEMPERATURES TODAY
TO BE COOLER THAN PREVIOUS DAYS. SFC FLOW SHOULD EVENTUALLY BEGIN TO
TURN MORE UPSLOPE ALONG/EAST OF THE LARAMIE RANGE IN THE AFTN...WITH
LLVL MOISTURE RAPIDLY INCREASING AS A RESULT. IN ADDITION...THE GFS
SHOWS A 100 KT H25 JET STREAK LIFTING INTO CENTRAL WY BY 00Z WITH A
LARGE PART OF THE CWA IN THE FAVORED RRQ. SCATTERED/NUMEROUS SHOWERS
AND TSTMS SHOULD BE THE NET RESULT. TENDENCY IS TO LEAN MORE TOWARD
THE NAM GIVEN THE RECENT DRY BIAS OF THE GFS WITH SURFACE DEW POINTS
5-10 DEGREES TOO LOW IN THE AFTN. DEW POINTS IN THE LOW-MID 50S AND
SURFACE TEMPS IN THE MID 70S YIELD SBCAPE OVER 1500 J/KG AS FAR WEST
AS CHEYENNE...WHICH COMBINED WITH 0 TO 6 KM VERTICAL SHEAR EXCEEDING
50 KTS WOULD SUGGEST SOME SEVERE POTENTIAL. PRIMARY AREA OF CONCERN
WOULD BE THE I80 CORRIDOR BETWEEN CYS-SNY. THE 06Z SPC DAY 1 OUTLOOK
HAS THIS REGION HIGHLIGHTED IN A SLGT RISK. INCREASING LLVL THETA-E
ADVECTION BETWEEN 00Z-06Z WOULD SUGGEST CONVECTION BECOMING FOCUSED
OVER THE SOUTHERN PANHANDLE...WITH THE THREAT TRANSITIONING TO VERY
HEAVY RAIN GIVEN NAM PWATS BETWEEN 1.5 AND 2.0 INCHES.
WHILE MODELS STILL DIFFER IN THE TIMING...THE GENERAL CONSENSUS IS
FOR THE AFOREMENTIONED TROUGH AXIS TO TRANSLATE EASTWARD ACROSS THE
CWA ON SUN. A PLUME OF MONSOONAL MOISTURE WILL REMAIN IN PLACE...SO
AT LEAST ISOLATED AFTERNOON CONVECTION CAN BE EXPECTED. THE 06Z NAM
IS COMING IN MORE BULLISH WITH QPF FIELDS...LIKELY DUE TO ENHANCED
LLVL CONVERGENCE VIA LEE TROUGHING AND LINGERING JET SUPPORT OVER
OUR NORTHERN ZONES. WE MAY NEED TO LOOK INTO BUMPING POPS INTO THE
SCATTERED CATEGORY IF THIS TREND CONTINUES. THIS COULD BE ANOTHER
OPPORTUNITY FOR STRONG/SEVERE STORMS EAST OF THE SFC TROUGH...IF
CLOUD COVER DOES NOT INHIBIT INSTABILITY. SPCS MARGINAL RISK LOOKS
GOOD FOR NOW. FOR MONDAY...THE MODELS ARE STILL HAVING A VERY HARD
TIME HANDLING SHORTWAVES WITHIN AN ACTIVE NORTHERN STREAM. GFS/ECM
CONTINUE TO ADVERTISE THE BATTLE OF TROUGH VS RIDGE...SO CONTINUED
TO KEEP LOW-END POPS OVER THE MOUNTAINS UNTIL WE CAN RESOLVE FINE
SCALE DETAILS.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY NIGHT)
ISSUED AT 310 AM MDT SAT JUL 18 2015
MEDIUM RANGE DETERMINISTIC MODELS CONTINUE TO STRUGGLE WITH
SHORTWAVE ENERGY MOVING EASTWARD EMBEDDED IN THE MEAN WESTERLY
FLOW ALOFT. THE GFS IS NOW MUCH MORE PROGRESSIVE WITH THE SECOND
SHORTWAVE FORECAST TO MOVE ACROSS WYOMING ON TUESDAY...WITH
ANOTHER ROUND OF SCATTERED SHOWERS AND TSTORMS MAINLY FOR THE
SOUTHERN TWO THIRDS OF THE FORECAST AREA. THE ECMWF AND GEM ARE
NEARLY 18 HOURS LATER WITH THIS SHORTWAVE AND DO NOT SHOW MUCH IN
THE WAY OF FORCING TUESDAY AND TUESDAY EVENING. THE ECMWF SHOWS
THIS SHORTWAVE CLIPPING THE AREA ON WEDNESDAY HOWEVER AS THE UPPER
LEVEL FLOW BEGINS TO VEER INTO THE NORTHWEST BEHIND THE WEAK UPPER
LEVEL TROUGH. KEPT POP BETWEEN 20 T0 40 PERCENT BOTH
DAYS...ESPECIALLY ALONG AND JUST NORTH OF THE I80 CORRIDOR. AT
THIS POINT...VERY DIFFICULT TO GET SPECIFIC FOR THE MIDDLE OF NEXT
WEEK. TEMPERATURES SHOULD TREND WARMER BY WEDNESDAY...BUT HIGHS
WILL BE NEAR OR SLIGHTLY BELOW NORMAL FOR THIS TIME OF THE YEAR.
BY THE END OF THE WEEK...MODELS SHOW A TYPICAL JULY WEATHER
PATTERN WITH VERY WARM TEMPERATURES AND RIDGING ALOFT EXTENDING
NORTHWARD ACROSS THE CENTRAL ROCKY MOUNTAINS. HIGH TEMPERATURES
IN THE MID 80S TO MID 90S ARE EXPECTED THROUGH THURSDAY AND
FRIDAY. CHANCES OF THUNDERSTORMS ARE UNCLEAR AT THIS TIME SINCE
MODELS IN THE LONG RANGE HAVE STRUGGLED WITH BOUNDARY LAYER
MOISTURE PROFILES THIS SUMMER. CAN NOT RULE OUT ISOLATED
THUNDERSTORMS ACROSS THE MOUNTAINS AND HIGH PLAINS AT THE VERY
LEAST...MAINLY DUE TO TRENDS THE LAST FEW MONTHS. THE GFS
ESPECIALLY HAS HAD THE TENDENCY TO SHOW A VERY DRY BOUNDARY LAYER
IN SOUTHWEST FLOW...SO WILL NOT PUT MUCH FAITH IN THIS SOLUTION AT
THIS TIME. DID INCREASE POP A BIT...BUT KEPT VALUES BELOW 15
PERCENT FOR NOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH SATURDAY NIGHT)
ISSUED AT 237 AM MDT SAT JUL 18 2015
VFR CONDITIONS ACROSS THE AREA EARLY THIS MORNING...BUT CAN NOT
RULE OUT THE POSSIBILITY OF SOME LOW STRATUS AND PATCHY FOG ACROSS
WESTERN NEBRASKA THROUGH SUNRISE. KEPT MVFR CONDITIONS FROM KSNY
NORTHWARD TO KBFF AND KAIA UNTIL 15Z. OTHERWISE...WINDS WILL SHIFT
INTO THE EAST OR SOUTHEAST TODAY AS A DISTURBANCE ALOFT MOVES
ACROSS THE AREA. THIS DISTURBANCE COMBINED WITH LLVL MOISTURE WILL
RESULT IN SCATTERED SHOWERS AND TSTORMS BY THIS AFTERNOON ACROSS
SOUTHEAST WYOMING AND WESTERN NEBRASKA. BRIEF MVFR TO NEAR IFR
CONDITIONS ARE POSSIBLE IN AND NEAR THE STRONGEST TSTORMS THROUGH
THIS EVENING.
&&
.FIRE WEATHER...
ISSUED AT 237 AM MDT SAT JUL 18 2015
MINIMAL FIRE WEATHER CONCERNS. SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS WILL DEVELOP ACROSS SOUTHEAST WY AND THE WESTERN NE
PANHANDLE TODAY AND TONIGHT...YIELDING A GOOD CHANCE FOR WETTING
RAINS OVER MUCH OF THE AREA. GUSTY/ERRATIC WINDS COULD ACCOMPANY
SOME THUNDERSTORMS. OVERALL CONDITIONS SHOULD REMAIN NON-CRITICAL
THROUGH THE WEEKEND WITH AFTERNOON RH VALUES ABOVE 20 PCT. A TREND
TOWARD WARMER AND DRIER CONDITIONS IS EXPECTED NEXT WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...SML
SHORT TERM...CLH
LONG TERM...TJT
AVIATION...TJT
FIRE WEATHER...CLH
AREA FORECAST DISCUSSION...UPDATED
NWS LITTLE ROCK AR
1230 AM CDT MON JUL 20 2015
.AVIATION...
OTHER THAN SUNRISE FOG AT KADF...VFR CONDITIONS WILL PREVAIL.
CURRENT TSRA ACROSS SOUTHERN MISSOURI SHOULD STAY AWAY FROM THE
NORTHERN SITES. AS THE COLD FRONT SAGS SOUTH TODAY...CLOUD COVER
WILL INCREASE. PRECIP WILL HOLD OFF UNTIL AFTER THIS TAF CYCLE.
&&
.PREV DISCUSSION... /ISSUED 939 PM CDT SUN JUL 19 2015/
UPDATE...
QUICK UPDATE TO THE FORECAST WITH SHOWERS AND THUNDERSTORMS
CONTINUING TO DEVELOP IN MISSOURI. IN ADDITION TO THE 12Z
WRF AND 00Z NAM...THE LATEST HRRR RUNS HAVE SHOWED FAIRLY GOOD
CONTINUITY WITH THESE THUNDERSTORMS CONTINUING TO DEVELOP AND PUSH
SOUTH THROUGH THE OVERNIGHT AND EARLY MORNING HOURS ACROSS
NORTHERN AND NORTHEAST ARKANSAS. CURRENT RADAR TRENDS DO SUGGEST
THE BEST CHANCES FOR PRECIPITATION WILL BE TO THE NORTHEAST OF
THE CWA...BUT WITHIN THE PAST HOUR ADDITIONAL STORMS HAVE BEGUN TO
DEVELOP A BIT FURTHER TO THE WEST OF THE MAIN SET OF STORMS. AS
SUCH...TOOK A CONSERVATIVE APPROACH FOR NOW AND JUST ADDED SOME
SLIGHT CHANCE POPS TO NORTHERN ARKANSAS...AS THESE STORMS SHOULD
WEAKEN DURING THE EARLY MORNING HOURS.
&&
.LZK WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ARKANSAS-BRADLEY-
CALHOUN-CLARK-CLEBURNE-CLEVELAND-CONWAY-DALLAS-DESHA-DREW-
FAULKNER-GARLAND-GRANT-HOT SPRING-INDEPENDENCE-JACKSON-JEFFERSON-
LINCOLN-LONOKE-MONROE-OUACHITA-PERRY-PRAIRIE-PULASKI-SALINE-
WHITE-WOODRUFF.
&&
$$
AVIATION...58
AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
250 AM PDT MON JUL 20 2015
.SYNOPSIS...
TROPICAL MOISTURE WILL CONTINUE FLOWING INTO THE REGION FROM THE
SOUTH THROUGH THE REMAINDER OF TODAY. AS A RESULT...THERE WILL
REMAIN A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH THIS EVENING. A
DRYING TREND AND A RETURN TO SUMMER LIKE TEMPERATURES IS EXPECTED BY
MID WEEK AS THE TROPICAL MOISTURE GETS PUSHED OUT OF OUR AREA.
&&
.DISCUSSION...
ALTHOUGH TROPICAL MOISTURE CONTINUED TO MOVE INTO CALIFORNIA SUNDAY
THE FOCUS WAS OVER THE SOUTHERN PART OF THE STATE...INCLUDING KERN
AND TULARE COUNTIES. THUNDERSTORMS CAUSED FLOODING AND MUD SLIDES IN
THE TEHACHAPI AND SAN EMIGDIO MOUNTAINS...AND ALTHOUGH THE RAINS HAD
TAPERED OFF AS OF 08Z /0100 PDT/...THE THREAT CONTINUED FROM SHOWERS
AND THUNDERSTORMS OVER INYO AND SAN BERNARDINO COUNTIES.
AN UPPER-LEVEL RIDGE PERSISTS OVER THE SOUTHERN UNITED STATES THIS
MORNING AS AN UPPER-LEVEL TROUGH DROPS INTO THE PACIFIC NORTHWEST.
THIS PATTERN RESULTS IN A SOUTHWESTERLY FLOW ALOFT OVER CENTRAL
CALIFORNIA WHICH CARRIES TROPICAL MOISTURE FROM FORMER HURRICANE
DOLORES INTO THE WFO HANFORD WARNING/FORECAST AREA.
DESPITE LESS CLOUDS THAN ORIGINALLY ANTICIPATED...HIGH TEMPERATURES
SUNDAY IN THE CENTRAL AND SOUTHERN SAN JOAQUIN VALLEY WERE WELL
BELOW NORMAL...IN THE UPPER 80S TO LOWER 90S. TEMPERATURES EARLY
THIS MORNING WERE RUNNING SIMILAR TO EARLY SUNDAY MORNING...SO
SHOULD SEE ANOTHER DAY WITH BELOW-NORMAL HIGHS.
ALTHOUGH CONVECTION HAS TEMPORARILY CEASED OVER THE CENTRAL
CALIFORNIA INTERIOR...THE MODELS KEEP ABUNDANT MID-LEVEL MOISTURE
OVER AT LEAST THE SOUTHERN HALF OF THE WFO HANFORD WARNING/FORECAST
AREA. OF INTEREST IS THAT BOTH THE NAM-12 AND THE HRRR HAVE LIMITED
MOISTURE OVER MERCED AND MARIPOSA COUNTIES TODAY...WITH THE NAM-12
FINALLY BRINGING THE MOISTURE NORTHWARD THIS EVENING AS KERN COUNTY
BEGINS TO DRY OUT. IF THIS VERIFIES...CONVECTION COULD CONTINUE OVER
MUCH OF THE REGION NORTH OF KERN COUNTY OVERNIGHT RATHER THAN BEING
CONFINED MAINLY TO THE SOUTHERN SIERRA NEVADA AFTER MIDNIGHT.
SUNDAY MORNING/S RFC QPF GUIDANCE FOR INTERIOR CENTRAL CALIFORNIA
CONTINUED A TREND OF BEING WETTER WITH EACH SUCCESSIVE RUN. THE RFC
STORM-TOTAL QPF FOR THE SOUTHERN SIERRA NEVADA FORECAST POINTS WAS
OVER AN INCH THROUGH TUESDAY MORNING. FURTHER SOUTH...ALTHOUGH THERE
ARE NO FORECAST POINTS...THE GROUND IS SATURATED FROM SUNDAY/S RAIN
SO THERE LIKELY WILL BE FLOODING FROM EXCESSIVE RUNOFF. WILL KEEP
THE FLASH FLOOD WATCH FOR THE MOUNTAIN AND DESERT AREAS IN PLACE
THROUGH THIS EVENING.
AS THE TROUGH DROPS THROUGH THE PACIFIC NORTHWEST AND INTO CENTRAL
CALIFORNIA THE SOUTHWEST FLOW ALOFT WILL STRENGTHEN AND BEGIN DRYING
OUT THE REGION BEGINNING WEDNESDAY. IN TURN...THE RIDGE IS FORECAST
TO BUILD BACK INTO CALIFORNIA WITH THE 500-MB 5880-METER HEIGHT LINE
PUSHING NORTH OF THE WFO HANFORD WARNING/FORECAST AREA BY FRIDAY.
&&
.AVIATION...
SCATTERED THUNDERSTORM ACTIVITY WILL PERSIST ACROSS THE MOUNTAIN AND
DESERT AREAS OF CENTRAL CALIFORNIA...WITH ISOLATED THUNDERSTORMS
ALSO POSSIBLE IN THE SAN JOAQUIN VALLEY OVER THE NEXT 24 HOURS.
THESE STORMS WILL BRING AREAS OF MVFR AND LOCAL IFR/VLIFR CONDITIONS
ALONG WITH WITH SOME POSSIBLE MOUNTAIN OBSCURATIONS IN THE HIGHER
TERRAIN. GUSTY AND ERRATIC WINDS AROUND 40 KTS CAN ALSO ACCOMPANY
THE STORMS. OTHERWISE...VFR CONDITIONS WILL PREVAIL OVER THE CENTRAL
CALIFORNIA INTERIOR.
&&
.AIR QUALITY ISSUES...
NONE.
&&
.CERTAINTY...
THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS HIGH.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM.
THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED
BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD.
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL
INFORMATION AND/OR TO PROVIDE FEEDBACK.
&&
.CLIMATE...
RECORDS
SITE DATE HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR
KFAT 07-20 111:1908 81:1973 78:1938 54:1903
KFAT 07-21 112:1908 79:1987 82:2006 56:1973
KFAT 07-22 112:2006 83:1896 84:2006 56:1903
KBFL 07-20 112:1938 84:1973 82:1979 49:1906
KBFL 07-21 112:1938 81:1987 83:1969 50:1906
KBFL 07-22 113:1908 82:1984 88:1910 50:1903
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS EVENING FOR THE SOUTHERN SIERRA
NEVADA FROM YOSEMITE NATIONAL PARK TO THE KERN COUNTY LINE
/CAZ096-097/.
FLASH FLOOD WATCH THROUGH THIS EVENING FOR THE KERN COUNTY
MOUNTAINS AND DESERT AND THE INDIAN WELLS VALLEY /CAZ095-098-099/.
&&
$$
PUBLIC...SANGER
AVN/FW...DURFEE
SYNOPSIS...ANDERSEN
WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS ALBANY NY
415 AM EDT MON JUL 20 2015
.SYNOPSIS...
A WEAK COLD FRONT WILL CONTINUE TO MOVE ACROSS THE REGION THIS
MORNING AND SLOW ITS PROGRESS ONCE IT REACHES THE MID HUDSON
VALLEY AND LITCHFIELD HILLS THIS AFTERNOON. THIS WILL RESULT IN
ISOLATED THUNDERSTORMS INTO EARLY EVENING. OTHERWISE...HIGH
PRESSURE WILL BUILD ACROSS THE REST OF THE REGION TODAY WITH
CONTINUED VERY WARM TEMPERATURES BUT LOWER HUMIDITY LEVELS. THE
HIGH WILL THEN SLIDE OFFSHORE TONIGHT. A STRONGER COLD FRONT WILL
CROSS THE REGION ON TUESDAY...BRINGING ADDITIONAL CHANCES FOR
SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD FROM CANADA
INTO THE GREAT LAKES WEDNESDAY...USHERING IN A COOLER AND DRIER
AIR MASS INTO THE REGION FOR MID WEEK TO LATE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 415 AM EDT...A WIND SHIFT BOUNDARY IS CURRENTLY PUSHING
EASTWARD ACROSS THE REGION...AS WINDS HAVE BECOME WESTERLY FOR
AREAS WEST OF THE HUDSON RIVER VALLEY EARLY THIS MORNING.
DEWPOINTS ARE STILL RATHER HIGH GENERALLY IN THE MID TO UPPER
60S...AS A SECONDARY DEWPOINT BOUNDARY IS LAGGING BACK TO THE
NORTH AND WEST OF LAKE ONTARIO AT THIS HOUR.
CONVECTION HAS WANED ACROSS OUR AREA...ALTHOUGH WE ARE WATCHING A
SMALL CLUSTER OF SHOWERS AND THUNDERSTORMS ACROSS THE SOUTHERN
CENTRAL TIER OF NY MOVING EASTWARD ALONG THE TAIL END OF THE WIND
SHIFT BOUNDARY ARCING BACK TO THE SOUTH AND WEST OF OUR REGION.
HI- RES MODELS INCLUDING THE LOCAL WRF AND HRRR INDICATE THIS
ACTIVITY SHOULD WEAKEN AS IT MOVES EAST WITH INSTABILITY
WEAKENING.
THE BOUNDARY WILL SHIFT SOUTHEASTWARD THROUGH THE DAY BUT SLOW
ITS PROGRESS AS IT REACHES ULSTER...DUTCHESS AND LITCHFIELD
COUNTIES. THE LINGERING BOUNDARY MAY BE ABLE TO PROVIDE ENOUGH LOW
LEVEL CONVERGENCE FOR ISOLATED THUNDERSTORMS THIS AFTERNOON INTO
EARLY EVENING FOR THIS LIMITED AREA. THERE SHOULD BE SUFFICIENT
SURFACE HEATING ALONG WITH DEWPOINTS IN THE MID 60S TO RESULT IN
SBCAPE VALUES IN THE 500-1000 J/KG RANGE. ELSEWHERE IT WILL BE DRY
WITH GRADUALLY LOWERING HUMIDITY LEVELS.
NOT MUCH OF A THERMAL GRADIENT ASSOCIATED WITH THE SURFACE
BOUNDARY...SO TEMPERATURES WILL BE VERY WARM AGAIN TODAY WITH
UPPER 80S IN MOST VALLEY LOCATIONS EXCEPT LOWER 90S IN THE MID
HUDSON VALLEY AND LITCHFIELD CT. IT WILL BE SLIGHTLY COOLER TO THE
NORTH AND WEST...WITH LOWER TO MID 80S FOR THE ADIRONDACKS AND
MOHAWK VALLEY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY/...
ANY ISOLATED CONVECTION ACROSS SOUTHERN AREAS WILL QUICKLY DIMINISH
AFTER DARK WITH LOSS OF DAYTIME HEATING. TONIGHT WILL BE COOLER THAN
RECENT NIGHTS WITH THE LOWER HUMIDITY...WITH VALLEY LOCATIONS
DROPPING INTO THE LOWER 60S WITH MID TO UPPER 50S IN THE HIGHER
TERRAIN. A COLD FRONT WILL BE MOVING EASTWARD THROUGH THE CENTRAL
AND EASTERN GREAT LAKES...AND WILL LIKELY BE JUST TO THE WEST OF OUR
REGION TUESDAY MORNING.
THE COLD FRONT AND ASSOCIATED UPPER LEVEL TROUGH WILL BE CROSSING
THE REGION FROM WEST TO EAST DURING THE DAY TUESDAY. THERE SHOULD BE
ENOUGH SURFACE HEATING AND LOW LEVEL MOISTURE INCREASING TO DEVELOP
AROUND 700-1500 J/KG OF SBCAPE AHEAD OF THE COLD FRONT. 0-6 KM SHEAR
IS FORECAST TO INCREASE TO BETWEEN 40-50 KTS DURING THE AFTERNOON
HOURS. SHOULD THE HIGHER RANGE OF INSTABILITY BE REALIZED...THERE
COULD BE A CONDITIONAL THREAT FOR SOME STRONGER ORGANIZED STORMS
PRODUCING GUSTY WINDS. MID LEVEL LAPSE RATES ARE FORECAST TO BE
SOMEWHAT MARGINAL...SO WE ARE NOT CONFIDENT IN MENTIONING ANY SEVERE
STORMS AT THIS TIME. TRENDS WILL BE MONITORED TO SEE IF SUFFICIENT
INSTABILITY CAN DEVELOP. TEMPERATURES WILL SPIKE AHEAD OF THE COLD
FRONT TO BETWEEN 85 AND 90 DEGREES FROM MAINLY THE HUDSON VALLEY AND
POINTS EAST. THIS WILL BE THE LAST DAY OF WELL ABOVE NORMAL
TEMPERATURES FOR THE REST OF THE WEEK.
BASED ON TIMING FROM MODEL GUIDANCE...CONVECTION SHOULD DIMINISH
TUESDAY EVENING AS THE COLD FRONT PUSHES SOUTH AND EAST OF OUR
AREA AND SUBSIDENCE TAKES OVER AS A SHORT WAVE RIDGE BUILDS IN AT
THE SURFACE. A COOLER AND DRIER PATTERN LOOKS TO DEVELOP ON
WEDNESDAY COURTESY OF A NORTHWEST FLOW REGIME. GENERAL TROUGHINESS
ALOFT WILL RESULT IN SOME DIURNAL CLOUDINESS ESPECIALLY OVER THE
HIGHER TERRAIN...WITH A FEW BRIEF SHOWERS POSSIBLE ACROSS THE
ADIRONDACKS. TEMPERATURES WILL BE NOTICEABLY COOLER AND SLIGHTLY
BELOW NORMAL. DEWPOINTS WILL DROP INTO THE 50S...MAKING IT FEEL
QUITE COMFORTABLE FOR LATE JULY. THE COOLER AND DRIER AIR MASS
WILL RESULT IN TEMPERATURES DROPPING INTO THE 50S WEDNESDAY NIGHT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
CYCLONIC UPPER FLOW IN EASTERN NORTH AMERICA WITH MEAN UPPER
TROUGHING WILL SUPPORT TEMPERATURES A LITTLE BELOW NORMAL WITH SOME
INTERVALS OF CLOUDS. THE MEAN AXIS OF THE UPPER TROUGH SHOULD BE
JUST EAST OF OUR REGION...SO ANY POSSIBLE SHOWERS ALONG THE SOUTHERN
PERIPHERY OF THE CYCLONIC UPPER FLOW SHOULD BE ISOLATED AND MAINLY
CONFINED TO NORTHERN AREAS THURSDAY AND FRIDAY. HIGHS BOTH DAYS IN
THE MID TO UPPER 70S...NEAR 80 SOUTH AND AROUND 70 TO LOWER 70S
NORTH.
ANOTHER ORGANIZED UPPER IMPULSE APPROACHES THE REGION LATER SATURDAY
WITH INCREASING WARM ADVECTION AND BOUNDARY LAYER FLOW SHIFTS TO
MORE SOUTHERLY WITH SOME MOISTURE ADVECTION AS WELL. BY SATURDAY
NIGHT AND SUNDAY...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS OVER
MOST OF THE REGION. WITH THE INTERVALS OF CLOUDS AND SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS...HIGHS SATURDAY AND SUNDAY IN
THE UPPER 70S TO LOWER 80S...LOWER 70S NORTHERN AREAS.
THERE ARE SOME DIFFERENCES IN LONG RANGE GUIDANCE IN THE SATURDAY
AND SUNDAY TIME FRAME AS TO THE STRENGTH OF UPPER DYNAMICS...LOW
LEVEL FORCING...MOISTURE AVAILABILITY AND TIMING OF THE SYSTEM...AND
DETAILS WILL GET CLEARER AS WE GET CLOSER TO NEXT WEEKEND.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
COLD FRONT SLOW TO TRACK THROUGH THE REGION...AS NEW THUNDERSTORMS
IN THE SOUTHERN ADIRONDACKS WILL GRADUALLY BUILD EAST AND SOUTH
THROUGH ABOUT 09Z...POSSIBLY GETTING INTO THE VICINITY OF KGFL.
PUTTING VCTS AT KGFL THROUGH 09Z...WHEN MESOSCALE MODELS SUGGEST THE
THUNDERSTORMS SHOULD DISSIPATE DUE TO DECREASING INSTABILITY DURING
THE EARLY MORNING HOURS.
THERE ARE SOME HINTS OF LOW LEVEL MOISTURE POSSIBLY CONTRIBUTING TO
SOME INTERVALS OF LOW CLOUDS AND FOG AT ALL TAF SITES THROUGH
SUNRISE...BUT THICK HIGH CLOUDS AND ENOUGH OF A TEMPERATURE DEW
POINT SPREAD ARE PREVENTING MUCH DEVELOPMENT OF FOG OR LOW CLOUDS.
THERE ARE ALSO SOME PERSISTENT LIGHT WINDS PREVENTING MUCH OF THE
FOG AND LOW CLOUDS AS WELL.
ONCE CONVECTION ENDS AROUND OR AFTER 09Z...HIGH CLOUDS SHOULD THIN
AND EXIT...SO SOME FOG AND LOW CLOUDINESS COULD AFFECT THE
CLIMATOLOGICALLY FAVORED SITES SUCH AS KGFL AND KPSF. SO...
INDICATING SOME BORDERLINE MVFR/IFR VISIBILITIES AND AT LEAST SOME
SCATTERED/BROKEN CLOUDS BELOW 1000 FEET THROUGH 13Z-14Z.
AFTER 13Z-14Z...ALL AREAS VFR THROUGH THE REST OF DAY AND EVENING
WITH JUST SCATTERED HIGH CLOUDS AT THE MOST. SOUTH TO SOUTHWEST
WINDS AT 6 KT OR LESS THROUGH SUNRISE ARE EXPECTED TO BECOME WEST TO
NORTHWEST THIS MORNING AND AFTERNOON AT LESS THAN 10 KT. WINDS
BECOME LIGHT AND VARIABLE AT LESS THAN 6 KT THIS EVENING.
OUTLOOK...
TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF TSRA.
TUESDAY NIGHT TO FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY: LOW OPERATIONAL IMPACT. ISOLATED SHRA.
&&
.FIRE WEATHER...
A WEAK COLD FRONT WILL CONTINUE TO MOVE ACROSS THE REGION THIS
MORNING AND SLOW ITS PROGRESS ONCE IT REACHES THE MID HUDSON VALLEY
AND LITCHFIELD HILLS THIS AFTERNOON. THIS WILL RESULT IN ISOLATED
THUNDERSTORMS INTO EARLY EVENING. OTHERWISE...HIGH PRESSURE WILL
BUILD ACROSS THE REST OF THE REGION TODAY WITH CONTINUED VERY WARM
TEMPERATURES BUT LOWER HUMIDITY LEVELS. THE HIGH WILL THEN SLIDE
OFFSHORE TONIGHT. A STRONGER COLD FRONT WILL CROSS THE REGION ON
TUESDAY...BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS.
HIGH PRESSURE WILL BUILD FROM CANADA INTO THE GREAT LAKES
WEDNESDAY...USHERING IN A COOLER AND DRIER AIR MASS INTO THE REGION
FOR MID WEEK TO LATE WEEK.
MINIMUM RELATIVE HUMIDITY VALUES THIS AFTERNOON ARE FORECAST TO BE
AROUND 35 TO 45 PERCENT...RECOVERING TO MAXIMUM VALUES OF 80 TO 100
PERCENT TONIGHT. MINIMUM RH VALUES ON TUESDAY WILL BE BETWEEN 35 AND
50 PERCENT.
WINDS TODAY WILL BECOME WESTERLY AROUND 5 TO 10 MPH...SHIFTING THE
NORTHWEST AROUND 5 MPH TONIGHT. WINDS ON TUESDAY WILL BECOME
SOUTHWEST AND INCREASE TO AROUND 10 TO 15 MPH.
&&
.HYDROLOGY...
MAINLY DRY CONDITIONS ARE EXPECTED THROUGH TONIGHT...WITH THE
EXCEPTION OF ISOLATED THUNDERSTORMS ACROSS ULSTER...DUTCHESS AND
LITCHFIELD COUNTIES...WHICH MAY BRING A QUICK BURST OF HEAVY RAIN IN
SOME SPOTS.
THE NEXT CHANCE OF AT LEAST SCATTERED SHOWERS AND THUNDERSTORMS
ARRIVES ON TUESDAY ASSOCIATED WITH A COLD FRONT. SOME LOCALLY HEAVY
RAINFALL WILL BE POSSIBLE IN ANY STRONGER STORMS...WITH PONDING OF
WATER IN URBAN AND POOR DRAINAGE LOCATIONS.
MAINLY DRY WEATHER IS THEN EXPECTED FROM WEDNESDAY THROUGH FRIDAY
EXCEPT FOR A FEW SHOWERS ACROSS PORTIONS OF THE ADIRONDACKS EACH DAY.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR
WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...JPV
NEAR TERM...JPV
SHORT TERM...JPV
LONG TERM...NAS
AVIATION...NAS
FIRE WEATHER...JPV
HYDROLOGY...JPV
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
344 AM EDT MON JUL 20 2015
.DISCUSSION...
TODAY AND TONIGHT...PRESENCE OF A FRONTAL TROUGH FROM THE MID ATLC
SEABOARD TO THE FL PANHANDLE WL KEEP THE SUBTROPICAL RIDGE
SITUATED SOUTH OF THE REGION. A PERSISTENT WEATHER FORECAST WITH
SCATTERED AFTERNOON STORMS IS EXPECTED WITH PRECIPITABLE WATER
SUITABLE NEAR 2.0 INCHES. SWLY WINDS FROM THE SFC THROUGH THE
STEERING LEVEL FAVOR THE EAST PENINSULA FOR OPTIMAL CONV
DEVELOPMENT FROM MID AFTERNOON ONWARD.
DEVELOPMENT OF A SLOW MOVING EAST COAST BREEZE BOUNDARY WL LEAD
TO HIGHEST RAIN AMOUNTS ALONG THE I-95 CORRIDOR SPACE COAST NWD.
LTST HRRR GUID SHOWS THIS SCENARIO SIMILAR TO WHAT OCCURRED ON
SUNDAY FROM AROUND 19Z THROUGH LATE AFTERNOON. THE ONLY INHIBITING
FACTOR REMAINS MID LEVEL TEMPS AROUND -6C (WHICH IS ABOUT 1-2C
WARMER THAN NORMAL). STORMS WL LARGELY COME TO AN END FROM 9-10
PM WHILE SHIFTING OVER THE ATLC WATERS AND DISSIPATING.
TUESDAY...PERSISTENT MID LEVEL TROUGHING OVER THE EASTERN U.S.
WL CONTINUE TO KEEP THE DLM RIDGE SUPPRESSED TO THE SOUTH OVER
THE FLORIDA STRAITS. GIVEN THE NARROW MOISTURE RIBBON AND LITTLE
MID AND UPPER LEVEL SUPPORT TRIMMED POP BACK TO 50 NORTH AND
DECREASING TO 30 SOUTH TUESDAY AFTERNOON.
SHOULD START TO SEE LATE MORNING SHOWERS COMING IN FROM THE
WEST/GULF SIDE OF CENTRAL FLORIDA. SHOWERS BECOME STORMS MID TO
LATE AFTERNOON WITH MAX HEATING AND AS THEY NEAR THE EAST/ATLANTIC
SIDE OF CENTRAL FLORIDA AS THEY HAVE BEEN DOING THE PAST DAYS.
TUESDAY NIGHT POPS LOOKED WAY TOO HIGH BASED ON WHAT HAS BEEN
ACTUALLY HAPPENING THE PAST FEW DAYS THUS LOWERED THE NIGHT POP TO
20 PERCENT. STORMS AND/OR SHOWER SHOULD BE ALL OVER WITHIN AN HOUR
OR TWO OF SUNSET. HIGHS TUESDAY LOW 90S AND LOWS WEDNESDAY MORNING
MID 70S EXCEPT LOW/MID 70S AT THE COAST MELBOURNE SOUTH WHERE
SLIGHTLY COOLER AIR FROM THE INTERIOR IS PUSHED EAST BY LAND
BREEZES.
WED-SUN...MODELS HAVE BEEN CONSISTENT IN SLOWLY PUSHING A FRONT
SOUTHWARD ACROSS THE SOUTHEAST STATES AND DOWN THE FLORIDA PENINSULA
PAST FEW RUNS. CONTINUED SOUTHWEST TO WEST WINDS AND LOW/MID 90S
EACH AFTERNOON. SCATTERED/CHANCE AFTERNOON POPS WED-THU. AS THE
FRONT NEARS LIKELY POP VOLUSIA/NORTH LAKE FRI THEN NORTH HALF SAT
SHIFTING TO THE SOUTH HALF SUN AS THE FRONT CONTINUES IT SLOW PUSH
DOWN THE STATE. HIGHS STILL IN THE LOW 90S. MORNING LOWS IN THE LOW
AND MID 70S.
&&
.AVIATION...THRU 21/12Z
WINDS: THRU 20/14Z...S/SW 3-6KTS. BTWN 20/14Z-20/17Z...S/SW
6-9KTS. BTWN 20/17Z-20/23Z...COASTAL SITES S/SE 8-12KTS...INTERIOR
SITES SW 7-10KTS. BTWN 20/23Z-21/03Z...S/SW 5-8KTS. AFT 21/03Z
S/SW AOB 4KTS.
VSBYS/WX/CIGS: BTWN 20/14Z-20/17Z...SLGT CHC MVFR SHRAS ALL
SITES. BTWN 20/17Z-20/24Z...SCT MVFR SHRAS/IFR TSRAS ALL
SITES...ISOLD LIFR +TSRAS WITH SFC G NR 35KTS.
&&
.MARINE...
TODAY AND TONIGHT...ATLC RIDGE AXIS OVER S FL WILL COMBINE WITH A WEAK
FRONTAL TROF OVER N FL TO MAINTAIN A PERSISTENT LIGHT TO GENTLE
S/SWRLY BREEZE OVER THE LCL ATLC...BCMG S/SE NEAR THE COAST IN THE
EARLY AFTN WITH THE FORMATION OF THE EAST COAST SEA BREEZE. SEAS AOB
2FT NEARSHORE AND 2-3FT OFFSHORE. SCT SHRAS/TSRAS MVG OFFSHORE
BTWN 2 PM AND SUNSET.
TUE-FRI...WEST TO SOUTHWEST WINDS THROUGH THE PERIOD. WINDS SHOULD
BE STRONG FRI AS THE GRADIENT AHEAD OF THE ADVANCING FRONT
STRENGTHENS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 92 75 92 76 / 50 20 50 20
MCO 93 74 92 76 / 40 20 50 20
MLB 92 74 91 76 / 40 20 40 20
VRB 92 73 92 74 / 40 30 30 20
LEE 91 77 91 78 / 50 20 50 20
SFB 93 77 92 77 / 50 20 50 20
ORL 92 76 92 77 / 40 20 50 20
FPR 93 72 91 74 / 40 30 30 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...PENDERGRAST
LONG TERM....WIMMER
AREA FORECAST DISCUSSION
NWS LINCOLN IL
319 AM CDT MON JUL 20 2015
.SHORT TERM...(TODAY)
ISSUED AT 318 AM CDT MON JUL 20 2015
CONVECTION THAT DEVELOPED NEAR ST.LOUIS LAST EVENING HAS SHIFTED
SOUTHEAST INTO EXTREME SOUTHERN ILLINOIS EARLY THIS MORNING. THE
STORMS ARC BACK TO THE NORTHWEST INTO PARTS OF WESTERN MO INTO
NORTHEAST KS ALONG A FRONTAL BOUNDARY WHICH LOOKS TO BE THE MAIN
FOCUS FOR ADDITIONAL DEVELOPMENT LATER TODAY. QUESTION BECOMES WHAT
AFFECT FURTHER NORTH INTO OUR AREA IT MAY HAVE ON COVERAGE OF
SHOWERS AND STORMS THIS AFTERNOON AND THIS EVENING AS ANOTHER COOL
FRONT TRACKS ACROSS THE AREA FROM THE NORTHWEST LATE TODAY.
USING THE TIMING AND COVERAGE OFF THE RAP MODEL WOULD SUGGEST A
SLOWER ONSET OF PRECIP THAN EARLIER EXPECTED WITH THE BULK OF THE
ACTIVITY TIED TO THE SURFACE BOUNDARY STRETCHING ACROSS MISSOURI
THRU FAR SOUTHERN ILLINOIS...WITH A SECONDARY BAND OF SHOWERS AND
STORMS SHOWING UP ALONG THE WEAK COOL FRONT WHICH IS FORECAST TO BE
JUST TO OUR NORTHWEST LATE THIS AFTERNOON. THE HIGHER POPS WILL BE
FOR MAINLY THIS AFTERNOON WITH ONLY LOW CHANCE POPS FOR PRECIP THIS
MORNING ACROSS OUR WEST. MIXED LAYER CAPES OFF THE NAM MODEL FOR
THIS AFTERNOON ARE EXPECTED TO RANGE FROM 1500-2000 J/KG WITH 0-6KM
SHEAR VALUES OF 30 KTS. 700-500 MB LAPSE RATES NOT LOOKING THAT
IMPRESSIVE THOUGH...BUT STILL CAN`T RULE OUT A STRONG TO LOCALLY
SEVERE STORM THAT MAY BE CAPABLE OF PRODUCING GUSTY WINDS ALONG WITH
HEAVY RAINFALL DURING THE MID TO LATE AFTERNOON HOURS. SPC HAS
SHIFTED THE SLIGHT RISK FURTHER SOUTH AND WEST...CLOSER TO THE
AFOREMENTIONED BOUNDARY OVER MISSOURI. WITH THE MAIN CONVECTIVE
FRONT EXPECTED TO REMAIN TO OUR SOUTH...IT APPEARS THAT IS WHERE THE
MORE CONCENTRATED AREA OF HEAVY RAINFALL WILL OCCUR...AS A
RESULT...WILL NOT BE INCLUDING ANY FLASH FLOOD WATCH AT THIS TIME
FOR OUR FAR WESTERN COUNTIES WHICH RECEIVED HEAVY RAINFALL LAST
NIGHT.
&&
.LONG TERM...(TONIGHT THROUGH SUNDAY)
ISSUED AT 318 AM CDT MON JUL 20 2015
SEVERAL WEAK BOUNDARIES IN THE REGION AND WILL CONTINUE TO PROVIDE
FOCUS FOR AN IMPULSE BRINGING PRECIP TODAY AND INTO TONIGHT.
HOWEVER, MODELS ARE SHIFTING SOUTH SOMEWHAT AND FOR THE MOST PART,
PUSH A COLD FRONT THROUGH THE STATE CONSIDERABLY FASTER TONIGHT.
GFS AND ECMWF ARE LARGELY DRY AFTER 06Z, WITH THE NAM STILL
STRUGGLING. HAVE PUSHED THE GRIDS CLOSER TO THAT SOLUTION, BUT THE
SLOWING NATURE OF THE BOUNDARY TOWARDS TOMORROW MORNING...HAVE KEPT
THE SLIGHTS ALONG AND SOUTH OF I-70, ALTHOUGH THOSE SMALL POPS MAY
ALSO GET PULLED WITH SUBSEQUENT FORECASTS IF THE TRENDS CONTINUE.
ELUSIVE DRY TREND IS BACK IN THE FORECAST FROM TOMORROW AFTERNOON
THROUGH WED EVENING, AND MUCH OF THURSDAY. THURSDAY A WAVE DIVES
INTO THE REGION AND ALTHOUGH MUCH OF THE PRECIP LOOKS TO PASS TO THE
SW, SOME SMALL POPS ARE WORKING THEIR WAY INTO THE SUPERBLEND ALONG
AND SW OF A LINE FROM HAVANA TO LAWRENCEVILLE. CONCERNED WITH THE
LOOK OF THE MODELS IN THAT TIME FRAME ARE NOT PROPERLY REPRESENTED
IN THE SUPERBLEND JUST YET. GFS IS MORE AGGRESSIVE WITH THE QPF ON
THURSDAY NIGHT OVER IL...AND ECMWF PASSES THE WAVE ALOFT IN THE SAME
TIME FRAME WITH LITTLE TO SHOW AT THE SFC. EXPECT SOME CHANGES IN
THIS PORTION OF THE FORECAST. WARMING TREND CONTINUES THROUGH THE
END OF THE WEEK, WITH THE HIGHEST TEMPS IN THE FORECAST NEXT WEEKEND
AGAIN. WITH THE WARM TEMPS, A RIDGE BUILDS IN THE DESERT SW AND
SOUTHERN PLAINS. ILLINOIS HAS VERY LITTLE IN THE WAY OF STEERING
FLOW AND MODELS ARE A BIT MORE SCATTERED WITH WEAK WAVES...WITH THE
GFS AND ECMWF DIVERGING AT THE WEEKEND DEALING WITH A TROF PASSING
ACROSS THE NRN TIER OF THE CONUS. FOR NOW, SLIGHT/CHANCE POPS
THROUGH THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1154 PM CDT SUN JUL 19 2015
SKIES HAVE BECOME CLEAR ACROSS THE AREA AND WITH WINDS BECOMING
LIGHT OVERNIGHT...EXPECTING LIGHT FOG TO DEVELOP AT ALL SITES. SO
WILL START ALL SITES WITH FOG AND CONTINUE THAT UNTIL THE MORNING
HOURS AROUND 14Z. THEN DURING THE MORNING HOURS...BELIEVE
CONVECTION WILL BEGIN TO ADVECT INTO THE AREA FROM THE WEST AS AN
MCS FROM THE PLAINS GETS INTO THE AREA...SOMETIME AFTER 15Z. THE
THREAT OF CONVECTION WILL OCCUR WITH THE MORNING STUFF AND THEN
CONTINUE INTO THE AFTERNOON AFTER SOME HEATING AND ANOTHER WAVE
MOVING THROUGH THE AREA. THIS LAST WAVE SHOULD PUSH OUT OF THE
AREA DURING THE EVENING BRINGING DRY WEATHER TO THE AREA FOR THE
REST OF THE FORECAST PERIOD. WINDS WILL BE LIGHT AND VARIABLE
OVERNIGHT AND THEN BECOME SOUTHWESTERLY AGAIN TOMORROW...THEN
FOLLOWED BY LIGHT AND VARIABLE AGAIN TOMORROW EVENING AS HIGH
PRESSURE BEGINS TO BUILD INTO THE AREA.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SMITH
LONG TERM...HJS
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
350 AM EDT MON JUL 20 2015
.SYNOPSIS...
ISSUED AT 350 AM EDT MON JUL 20 2015
HIGH PRESSURE WILL QUICKLY MOVE ACROSS THE REGION TODAY. A WEAK
COLD FRONT WILL APPROACH LATE THIS AFTERNOON AND MOVE ACROSS THE
AREA TONIGHT. THERE WILL BE A SMALL CHANCE FOR SHOWERS AND
THUNDERSTORMS NEAR THIS FRONT. OTHERWISE TODAY WILL BEGIN MOSTLY
SUNNY WITH INCREASING CLOUDS THIS AFTERNOON. HIGH TEMPERATURES
WILL BE IN THE LOWER TO MIDDLE 80S. LOWS TONIGHT WILL BE IN THE
LOWER AND MIDDLE 60S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM EDT MON JUL 20 2015
WEAK HIGH PRESSURE WILL MOVE EAST TODAY WHILE SHORT WAVE AND
ASSOCIATED COLD FRONT APPROACH LATE THIS AFTERNOON AND MOVE
THROUGH CWA TONIGHT. FORCING AND MOISTURE FLUX WEAK WITH THIS
SYSTEM BUT ENOUGH AMBIENT MOISTURE AND WEAK LIFT TO SUPPORT CHANCE
POPS FROM LATE THIS AFTERNOON THROUGH TONIGHT. RAP AND HRRR SEEM
TO HAVE BEST HANDLE ON UPSTREAM CONVECTION EARLY THIS MORNING.
BOTH MODELS WEAKEN CONVECTION AS IT MOVES EAST TODAY BUT STILL
SHOW SOME SCATTERED DEVELOPMENT IN OUR AREA BY LATE AFTERNOON AND
THROUGH THE EVENING. SEVERE WEATHER THREAT LOOKS MINIMAL AS
MUCAPES ONLY IN THE 1-2K J/KG RANGE AT BEST AND 0-3KM SHEAR
BETWEEN 20 AND 30KTS. LACK OF STRONG CONVERGENCE AND OVERNIGHT
TIMING SHOULD ALSO LIMIT DEVELOPMENT. COLD FRONT WILL PUSH SOUTH
BY EARLY TUESDAY MORNING ENDING PCPN CHANCES FROM NORTH TO SOUTH
OVERNIGHT WITH EVEN DRIER AIR WORKING IN.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 349 AM EDT MON JUL 20 2015
A SECOND SURGE OF COOL AIR WILL SPREAD ACROSS THE REGION BEHIND A
COLD FRONT EARLY TUESDAY. A SURFACE HIGH PRESSURE SYSTEM WILL BE
OVER THE REGION FOR THE NEXT SEVERAL DAYS. TEMPERATURES WILL FALL
WELL BELOW NORMAL BEHIND THE COOL FRONT TUESDAY NIGHT...FOLLOWED
BY A GRADUAL MODERATION LATER IN THE WEEK. THE SUBTROPICAL RIDGE
WILL EXTEND WELL INLAND...INTO THE SOUTHERN PLAINS... AND
EVENTUALLY BUILD FURTHER WEST INTO THE SOUTHWEST CONUS. HIGHS HERE
WILL BE IN THE 70S TUESDAY AND WEDNESDAY...RISING INTO THE 80S BY
FRIDAY AS A PORTION OF THE UPPER LEVEL RIDGE TEMPORARILY BUILDS
INTO THE AREA. CONDITIONS SHOULD BE DRY THROUGH FRIDAY...BUT SOME
ENERGY SHOULD BE ABLE TO TOP THE UPPER LEVEL RIDGE AND BRING A
CHANCE FOR THUNDERSTORMS THIS COMING WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 117 AM EDT MON JUL 20 2015
VFR CONDITIONS GENERALLY EXPECTED THROUGH THE PERIOD BUT POCKETS
OF GROUND FOG ARE POSSIBLE BRIEFLY AROUND DAYBREAK. A WEAK COLD
FRONT WILL MOVE THROUGH TONIGHT. THERE IS A SMALL CHANCE FOR
SHOWERS OR THUNDERSTORMS NEAR THIS FRONT BUT CHANCES ARE TOO LOW
FOR INCLUSION IN TAF AT THIS TIME.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...SKIPPER
AVIATION...LASHLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
124 AM EDT MON JUL 20 2015
.SYNOPSIS...
ISSUED AT 120 AM EDT MON JUL 20 2015
HIGH PRESSURE WILL QUICKLY MOVE ACROSS THE REGION TODAY. A WEAK
COLD FRONT WILL APPROACH LATE THIS AFTERNOON AND MOVE ACROSS THE
AREA TONIGHT. THERE WILL BE A SMALL CHANCE FOR SHOWERS AND
THUNDERSTORMS NEAR THIS FRONT. OTHERWISE TODAY WILL BEGIN MOSTLY
SUNNY WITH INCREASING CLOUDS THIS AFTERNOON. HIGH TEMPERATURES
WILL BE IN THE LOWER TO MIDDLE 80S. LOWS TONIGHT WILL BE IN THE
LOWER AND MIDDLE 60S.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 343 PM EDT SUN JUL 19 2015
COLD FRONT IS CURRENTLY PUSHING SE THROUGH THE FORECAST AREA AS
OF 1930Z. SCATTERED CONVECTION HAS DEVELOPED AHEAD OF THE FRONT
FROM FORT WAYNE EASTWARD TO FINDLAY...WHERE SBCAPES HAVE REACHED
3000 TO 4000 J/KG. SHEAR IS WEAK WITH 500MB SPEED MAX WELL NORTH
OF THE AREA. FRONTAL FORCING IS WEAK AS WELL...WITH BETTER VEERING
WINDS AND LOWER TEMPS/DEWPOINTS WELL TO THE NORTHWEST. W/ MARGINAL
LAPSE RATES AND WEAK FORCING/SHEAR...EXPECT SEVERE THREAT TO BE
FAIRLY MINIMAL THROUGH THE REST OF THE AFTERNOON/EARLY EVENING.
ASIDE FROM A LOW DAMAGING WIND THREAT...HEAVY RAINFALL IS THE
PRIMARY THREAT GOING FORWARD...W/ PWATS MAXING OUT NEAR 2.00
INCHES SOUTH OF THE BOUNDARY.
AS FAR AS POPS GO...KEPT THEM IN THE CHANCE RANGE THROUGH 00Z...WITH
A GRADUAL DIMINISH FROM NORTH TO SOUTH AND THE FRONT CONTINUES TO
PUSH THROUGH THE AREA. THERE MAY BE AN UPTICK IN COVERAGE BETWEEN
21Z AND 00Z AS FRONTAL FORCING BECOMES A BIT STRONGER...HOWEVER HI
RES GUIDANCE...PARTICULARLY RECENT HRRR RUNS...HAVE SUGGESTED
MINIMAL ADDITIONAL COVERAGE THROUGH THIS TIME PERIOD. TAPERED OFF TO
DRY CONDITIONS AFTER 06Z...WITH CLEARING SKIES WORKING SOUTH THROUGH
THE FORECAST AREA AS WELL. LOWS SHOULD RANGE FROM THE LOW TO MID 60S
ACROSS THE AREA.
HIGH PRESSURE WILL MOVE QUICKLY ACROSS THE GREAT LAKES REGION LATE
OVERNIGHT THROUGH THE DAY MONDAY...AS THE FRONTAL BOUNDARY LINGERS
JUST SOUTH OF THE AREA. CLOUD COVER WILL INCREASE FROM THE WEST
THROUGH THE DAY AS A SHORTWAVE TRACKS EAST FROM KANSAS TOWARDS THE
OHIO VALLEY...AND ANOTHER COLD FRONT DROPS TOWARD THE AREA FROM THE
NORTHWEST. THIS MAY SPARK AN AFTERNOON THUNDERSTORM...MAINLY ACROSS
THE WEST/SOUTHWEST PART OF THE FORECAST AREA...AS VERY WEAK
DESTABILIZATION OCCURS...MAINLY SOUTHWEST OF THE FORECAST AREA.
CONFIDENCE IS LOW AT ANY PRECIP COVERAGE BEFORE 00Z...HOWEVER FOR
COLLABORATION SAKE...ADDED SLIGHT CHANCE POPS WEST/SOUTHWEST AFTER
21Z. HIGH TEMPS SHOULD REMAIN IN THE LOW TO MID 80S. WENT SLIGHTLY
COOLER THAN PREVIOUS FCST GIVEN EXPECTED CLOUD COVER AHEAD OF
UPSTREAM SYSTEMS.
&&
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 343 PM EDT SUN JUL 19 2015
DIFFUSE CDFNT MOVG THROUGH OUR AREA TODAY WILL STALL OUT OVER THE
OH VALLEY/MID MS VALLEY TONIGHT WITH REMNANT BOUNDARY AND
ASSOCIATED MOISTURE POOL LIFTING BACK N-NE MONDAY AS SHRTWV AND
ASSOCIATED CDFNT OVER SASK MOVES SE INTO THE UPR GRTLKS AND SECOND
VORT MAX OVER WY GETS INGESTED INTO THE WRLYS AND MOVES TO THE
MID MS VALLEY. COMBINATION OF THESE TWO FORCING MECHANISMS AND
RETURN MOISTURE/DESTABILIZATION MAY BE SUFFICIENT TO CAUSE SCT
TSTMS IN OUR AREA MONDAY NIGHT... CONTINUED WITH HIGHEST POPS
ACROSS SOUTHERN PORTION OF THE CWA CLOSER TO THE TRACK OF THE SRN
STREAM VORT MAX. THE NRN STREAM SHRTWV MOVG THROUGH THE UPR GRTLKS
WILL RESULT IN STRENGTHENING OF THE ONTARIO UPR LOW AND
AMPLIFICATION OF THE FLOW ALOFT ACROSS THE CENTRAL CONUS/CANADA.
THIS WILL ALLOW A RATHER STRONG SFC HIGH TO DRIFT SLOWLY SE-E FROM
THE NRN PLAINS ACROSS THE GRTLKS PROVIDING FAIR WX ACROSS OUR AREA
FOR THE REMAINDER OF THE WORK-WEEK. BY THE WEEKEND... SFC HIGH
SHOULD MOVE TO THE ERN CONUS WITH MOISTURE/INSTABILITY/WAA
RETURNING TO OUR AREA AND COMBINING WITH WK SHRTWV`S MOVG OVER THE
TOP OF THE SRN PLAINS/ROCKIES UPR HIGH BRINGING A CHC OF TSTMS
BACK TO OUR AREA. THE NW FLOW ALOFT SHOULD KEEP TEMPS BLO NORMAL
THROUGH THE WORKWEEK...PSBLY RISING BACK ABOVE NORMAL NEXT
WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 117 AM EDT MON JUL 20 2015
VFR CONDITIONS GENERALLY EXPECTED THROUGH THE PERIOD BUT POCKETS
OF GROUND FOG ARE POSSIBLE BRIEFLY AROUND DAYBREAK. A WEAK COLD
FRONT WILL MOVE THROUGH TONIGHT. THERE IS A SMALL CHANCE FOR
SHOWERS OR THUNDERSTORMS NEAR THIS FRONT BUT CHANCES ARE TOO LOW
FOR INCLUSION IN TAF AT THIS TIME.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...LASHLEY
SHORT TERM...NG
LONG TERM...JT
AVIATION...LASHLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
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AREA FORECAST DISCUSSION
NWS GOODLAND KS
1139 PM MDT SUN JUL 19 2015
.UPDATE...
ISSUED AT 825 PM MDT SUN JUL 19 2015
UPDATED GRIDS AND ZONES DUE TO CANCELLING SEVERE THUNDERSTORM
WATCH 444. ALSO CANCELLED THE FLASH FLOOD WATCH DUE TO STRONGER
STORMS WEAKENING AND MOVING OUT OF THE FA. DO NOT EXPECT ANY
ADDITIONAL STORMS OVERNIGHT THAT WOULD HAVE HEAVY RAINFALL
POTENTIAL.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 157 PM MDT SUN JUL 19 2015
COMPLICATED SURFACE PATTERN IN PLACE. EITHER OR SOME COMBINATION
OF A LEFT OVER OUTFLOW BOUNDARY...SURFACE TROUGH RETREATING FRONT
IS NOW NEAR OR OVER THE SOUTHERN PORTION OF THE AREA. SHORTWAVE
TROUGH IS STARTING TO MOVE THROUGH FROM THE SOUTH AND WEST. A WEAK
RIGHT REAR QUADRANT IS MOVING THROUGH THE AREA DURING THE NIGHT.
THE RAP IS CATCHING THE SURFACE WIND FIELD THE BEST RIGHT NOW. IT
AND THE HRRR WHICH DID WELL FROM LAST NIGHT...IS CATCHING THE WIND
FIELD AND THE CURRENT AND EXPECTED THUNDERSTORM DEVELOPMENT VERY
WELL RIGHT NOW. STORMS WILL CONTINUE INCREASE IN COVERAGE AND
INTENSITY THROUGH TONIGHT AS STORMS MOVE ACROSS THE AREA THROUGH
THE OVERNIGHT HOURS.
VERY UNSTABLE AIR MASS AND EXPECT SOME OF THESE STORMS TO BECOME
SEVERE. HOWEVER THE BIGGEST THREAT WILL BE THE HEAVY RAINFALL AND
POSSIBLE FLASH FLOODING. AIR MASS REMAINS VERY MOIST THROUGH A
DEEP DEPTH. WHERE THE THREAT FOR HEAVY RAINFALL MATCHES UP WITH
WHERE HEAVY RAINFALL/SOME FLASH FLOODING OCCURRED LAST NIGHT/EARLY
THIS MORNING IS OVER THE SOUTHERN HALF OF THE AREA. THEREFORE A
FLASH FLOOD WATCH HAS BEEN ISSUED THROUGH TONIGHT.
VERY LIGHT LINGERING RAINFALL MAY BE AROUND THROUGH MID MORNING.
AFTER THAT IT SHOULD STAY QUIET UNTIL MID AFTERNOON. WEST TO
NORTHWEST FLOW ALOFT WITH ANOTHER SHORTWAVE TROUGH TO MOVE
THROUGH. AIR MASS DOES NOT APPEAR AS MOIST. ALSO SURFACE BOUNDARY
LOOKS TO BE SOUTH OF AREA. MODELS ARE NOT VERY EXCITED ABOUT THE
AFTERNOON RAINFALL CHANCES. HOWEVER CONSIDERING THE RESIDUAL
MOISTURE IN PLACE AND A SHORTWAVE TROUGH IN A WEST TO NORTHWEST
FLOW ALOFT...AM KEEPING SLIGHT TO CHANCE POPS FOR NOW.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 254 PM MDT SUN JUL 19 2015
FOR THE EXTENDED FORECAST PERIOD...NEEDED TO MAKE SOME CHANGES FOR
THIS RUN AS MODELS HAVE COME INTO BETTER AGREEMENT WITH RESPECT TO
TWO FEATURES. FIRST...GUIDANCE IS HONING IN ON A MORE SOUTHERN
SOLUTION WITH REGARDS TO PRECIPITATION CHANCES MONDAY NIGHT THROUGH
TUESDAY NIGHT. THIS IS LIKELY DUE TO A FURTHER SOUTH PUSH FROM THE
FRONT THAN ORIGINALLY ANTICIPATED. SECOND...GUIDANCE IS IN BETTER
AGREEMENT ON THE LOCATION AND STRENGTH OF THE 500 MB HIGH PRESSURE
RIDGE THAT DEVELOPS TOWARDS THE END OF THE WEEK.
BEGINNING WITH MONDAY NIGHT...ANTICIPATE RELATIVELY QUIET WEATHER
DUE TO THE FRONT AND THUS CONVECTIVE ACTIVITY REMAINING FURTHER
SOUTH. SOME MODELS CONTINUE INDICATING ISENTROPIC LIFT DEVELOPING AS
A LOW LEVEL JET STRENGTHENS OVER THE FRONT. A NARROW TONGUE OF
INSTABILITY RETURNS WITHIN THE SOUTHEASTER FLOW EARLY TUESDAY
MORNING SO SOME ELEVATED SHOWERS/STORMS MAY BE ABLE TO DEVELOP. ALL
PARAMETERS ARE DELAYED BY 6-12 HOURS FROM YESTERDAY SO ACTIVITY MAY
HOLD OFF UNTIL AFTER SUNRISE TUESDAY. THEREFORE...LOWERED POPS FOR
MONDAY NIGHT.
FOR TUESDAY THROUGH WEDNESDAY...ANOTHER WET PERIOD IS ANTICIPATED.
UNCERTAINTY REMAINS ON THE EXACT AXIS WHERE THE RAIN WILL OCCUR. IN
ADDITION...THERE MAY BE A TIGHT GRADIENT BETWEEN LITTLE TO NO
RAINFALL AND ANOTHER ROUND OF BENEFICIAL SOAKING RAINS. THE BEST
FORCING SHOULD ARRIVE DURING THE DAY TUESDAY...SLOWLY TRANSITIONING
INTO CENTRAL KANSAS BY WEDNEDAY MORNING. THEREFORE...THE BEST
CHANCES FOR WIDESPREAD PRECIPITATION SHOULD OCCUR TUESDAY NIGHT WITH
CHANCES DIMINISHING WEDNESDAY. PRECIPITABLE WATER VALUES INCREASE
TUESDAY AND TUESDAY NIGHT...REACHING A MAXIMUM NEAR 1.60 INCHES BY
WEDNESDAY MORNING. THEREFORE...RAIN COULD BE HEAVY AT TIMES WITH
SOME THUNDERSTORMS.
BY LATE WEDNESDAY INTO THURSDAY...THE RIDGE OF HIGH PRESSURE OVER
THE SOUTHERN UNITED STATES SLIDES WEST AND STRENGTHENS/BUILDS NORTH
OVER THE HIGH PLAINS. THIS SHOULD LEAD TO AN END IN PRECIPITATION
CHANCES FOR THE MOST PART AS WELL AS A RETURN TO HOT TEMPERATURES.
FOR THURSDAY THROUGH AT LEAST NEXT WEEKEND...SOME MEMBERS OF THE
FORECAST GUIDANCE DO INDICATE CHANCES FOR ISOLATED THUNDERSTORMS.
HOWEVER...THERE IS NOT A CONSISTENT SIGNAL AMONGST THE GUIDANCE AND
NO TIME PERIODS IN PARTICULAR TO HONE IN ON. IN FACT...THINK THAT
MOST LIKELY THE REGION REMAINS DRY DUE TO CLOSENESS/STRENGTH OF THE
HIGH PRESSURE RIDGE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1137 PM MDT SUN JUL 19 2015
VFR CONDITIONS ARE EXPECTED OVERNIGHT AND MONDAY BEHIND THE
CURRENT EXITING SHORTWAVE. RADAR SHOWING THE BACK EDGE OF STORMS
MOVING WELL TO THE EAST OF THE AREA. THERE IS A SLIGHT CHANCE OF
ANOTHER ROUND OF STORMS MONDAY AFTERNOON AND EVENING BUT THE FRONT
SHOULD BE SOUTH OF THE TERMINALS WITH LITTLE CHANCE OF ANY STORM
IMPACTING THEM.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...FS
SHORT TERM...BULLER
LONG TERM...RRH
AVIATION...FS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
358 AM CDT MON JUL 20 2015
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 358 AM CDT MON JUL 20 2015
THE DILEMMA TODAY IS HOW TO RECONCILE 2 MCS/S WITH THE POTENTIAL
FOR A HEAT ADVISORY OVER MUCH OF THE AREA. ONE MCS IS CURRENTLY RAINING
ITSELF OUT OVER OUR REGION...WHILE A SECOND ONE IS MOVING EASTWARD
OUT OF NORTHEAST KANSAS AND WESTERN MISSOURI. THERE IS A CORRIDOR
OF CONVECTION WITH THE POTENTIAL FOR FLASH FLOODING EXTENDING
BETWEEN THE TWO SYSTEMS FROM REYNOLDS COUNTY NORTHWESTWARD.
THE LATEST HRRR HAS A GOOD HANDLE ON THE FIRST MCS...SLOWLY
DISSIPATING IT AS IT MOVES OVER WEST KENTUCKY THROUGH 14Z. IT DOES
NOT HAVE A GOOD HANDLE ON THE CONVECTION FROM REYNOLDS COUNTY
WESTWARD. IT TAKES THE BULK OF THE WESTERN MCS EASTWARD...KEEPING
IT NORTHWEST OF OUR AREA THROUGH 18Z. UNFORTUNATELY...THERE IS
SOME POTENTIAL FOR THE REYNOLDS COUNTY CONVECTION TO PUSH EAST AND
IMPACT AREAS ALONG AND NORTH OF A PIEDMONT TO CAPE GIRARDEAU LINE.
CONTEMPLATED JOINING SGF AND LSX IN ISSUING A FLASH FLOOD WATCH
FOR A PORTION OF SOUTHEAST MISSOURI...BUT RECENT RADAR TRENDS SHOW
ENOUGH EASTWARD MOVEMENT OF THE ENTIRE ZONE THAT IT SHOULD NOT BE
A MAJOR ISSUE IN OUR AREA.
WITH THE RAIN OVER THE AREA SURFACE DEWPOINTS WILL LIKELY HOLD IN
THE MID TO UPPER 70S THROUGH THE DAY. IF THE PRECIPITATION AND THE
ASSOCIATED CLOUD COVER DISSIPATE...TEMPERATURES COULD QUICKLY
CLIMB BACK INTO THE 90S. THE BOTTOM LINE IS THAT HEAT INDICES ARE
FORECAST TO REACH NEAR 105 OVER MOST OF SOUTHEAST MISSOURI...THE
PURCHASE AND LAKES AREAS OF WEST KENTUCKY...AND ADJACENT PORTIONS
OF SOUTHERN ILLINOIS.
CONTEMPLATED ISSUING A HEAT ADVISORY GIVEN THIS FORECAST...BUT
THERE ARE A LOT OF MOVING PARTS THAT HAVE TO COME TOGETHER TO MAKE
IT HAPPEN. CONFIDENCE IS JUST NOT HIGH ENOUGH. IF I WOULD HAVE
ISSUED AN ADVISORY WITH THIS PACKAGE IT WOULD HAVE ONLY BEEN FOR
BUTLER...RIPLEY AND CARTER COUNTIES...WHERE THEY ARE MOST LIKELY
TO SEE A GOOD BIT OF SUNSHINE TODAY. WILL LET THE DAY SHIFT
MONITOR RADAR AND SATELLITE TRENDS AND ISSUE AN ADVISORY WHEN
CONFIDENCE INCREASES ENOUGH.
CONFIDENCE IN CONVECTIVE TRENDS BEYOND THIS MORNING IS QUITE LOW.
THE GENERAL TRENDS ARE FOR BETTER CHANCE POPS OVER THE WESTERN
HALF OF SOUTHERN ILLINOIS THIS AFTERNOON AS THE KS/MO MCS GLANCES
BY THE REGION. TONIGHT A COLD FRONT IS STILL SUPPOSED TO REACH THE
AREA...SO WILL HAVE LIKELY POPS OVER MUCH OF THE REGION.
THE CONSENSUS OF 00Z GUIDANCE HAS THE FRONT OUT OF THE AREA BY
EARLY TUESDAY...SO WOULD NOT BE TERRIBLY SURPRISED IF MUCH IF NOT
ALL OF THE AREA IS DRY TUESDAY THROUGH WEDNESDAY. THE NAM AND GFS
GENERATE SCATTERED CONVECTION ALONG WHAT LOOKS LIKE THE 925MB OR
850MB FRONT OVER THE SOUTHERN OR SOUTHEASTERN HALF OF THE AREA
TUESDAY. THIS SIGNAL WAS THERE 24 HOURS AGO...SO WILL KEEP 30-40
PERCENT POPS FOR MUCH OF THE AREA.
PROBABLY HAVE TOO MUCH POP LEFT OVER TUESDAY NIGHT AND WEDNESDAY.
IF THERE IS TO BE CONVECTION IN THE AREA IN THESE PERIODS IT WOULD
MOST LIKELY BE IN OUR WESTERN SOUTHEAST MISSOURI COUNTIES.
WITH NORTHERLY WINDS EXPECTED TUESDAY THROUGH WEDNESDAY...A
COOLING TREND IS FORECAST. HIGHS WILL RANGE FROM THE LOWER 80S
NORTH TO THE MID 80S SOUTH ON WEDNESDAY. ENJOY!
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 358 AM CDT MON JUL 20 2015
THE LONG TERM PORTION OF THE FORECAST CENTERS AROUND THE BEHAVIOR OF
AN UPPER LEVEL RIDGE OVER THE PLAINS. THE MODELS HAVE SHOWN
VARIATIONS REGARDING HOW QUICKLY /AND TO WHAT EXTENT/ THE RIDGE
EXPANDS EAST OVER THE MISSISSIPPI VALLEY. THE 00Z MODEL SUITE DOES
NOT SHOW ANY MORE MODEL AGREEMENT THAN EARLIER RUNS. TAKING A BLEND
OF ALL THE MODELS...THERE WILL BE A GRADUAL RETURN TO HOTTER AND
MORE HUMID WEATHER ALONG WITH SMALL DAILY PRECIP CHANCES.
AS FAR AS THE DAILY DETAILS...
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...IT APPEARS A FRONTAL
BOUNDARY WILL BECOME STATIONARY OVER OUR REGION. THE NORTHWEST TO
SOUTHEAST ORIENTED BOUNDARY SHOULD BE THE FOCUS FOR SCATTERED
SHOWERS AND STORMS. HIGH PRESSURE OVER THE UPPER OHIO VALLEY WILL
FUNNEL RELATIVELY DRY AIR INTO SOUTHWEST INDIANA AND ADJACENT AREAS.
THEREFORE...POPS WILL BE NO HIGHER THAN SLIGHT CHANCE THERE.
SOUTHWEST OF THE BOUNDARY...RICHER BOUNDARY LAYER MOISTURE WILL
SUPPORT POPS OCCASIONALLY IN THE LIKELY CATEGORY IN PARTS OF
SOUTHEAST MISSOURI. EXTENSIVE CLOUDS AND PRECIP WILL LIMIT HIGHS
TO THE LOWER AND MID 80S...EVEN SOUTH OF THE BOUNDARY.
ON FRIDAY AND FRIDAY NIGHT...RISING 500 MB HEIGHTS ASSOCIATED WITH
THE PLAINS RIDGE WILL TRANSLATE INTO A GRADUAL WARMING AND DRYING
TREND. THE RIDGE WILL NOT BUILD EAST SUFFICIENTLY TO QUASH ALL
CHANCES OF CONVECTION. THERE WILL STILL BE A SMALL CHANCE OF PRECIP
DUE TO THE POTENTIAL FOR IMPULSES IN THE WEAK NORTHWEST FLOW ALOFT.
HIGHS WILL GENERALLY BE AROUND 90 ON FRIDAY...EXCEPT FOR MID TO
UPPER 80S NEAR AND NORTH OF INTERSTATE 64.
SATURDAY THROUGH SUNDAY...THE FLOW PATTERN WILL BECOME VERY WEAK AT
LOWER AND MID LEVELS. ANY EXPANSION OF THE RIDGE WILL BE VERY
SLIGHT. ISOLATED DIURNALLY INDUCED CONVECTION IS POSSIBLE BOTH
DAYS...BUT NOT ENOUGH TO WARRANT POPS IN MOST AREAS. ALONG AND WEST
OF THE MISSISSIPPI VALLEY...WILL MENTION SLIGHT CHANCE POPS DUE TO
THE STRONGER INSTABILITY AND HIGHER DEW POINTS IN THAT AREA. HIGHS
SHOULD GENERALLY BE IN THE LOWER 90S WITH LOWS IN THE LOWER 70S.
&&
.AVIATION...
ISSUED AT 621 PM CDT SUN JUL 19 2015
AN ISOLATED SHOWER/THUNDERSTORM MAY CONTINUE IN THE VICINITY OF
KOWB EARLY THIS EVENING. WILL RE-INTRODUCE VICINITY
SHOWERS/THUNDERSTORMS AT ALL TAF SITES OVERNIGHT AS A WEAK COLD
FRONT PUSHES SOUTH TOWARD THE REGION WITH SUPPORT FROM AN UPPER
LEVEL DISTURBANCE. WILL ALSO INCLUDE A VICINITY THUNDERSTORM AT
KEVV AND KOWB LATE MONDAY AFTERNOON. WINDS WILL EITHER BE LIGHT
AND VARIABLE OR OUT OF THE SOUTHWEST TO WEST AOB 6 KNOTS TONIGHT
WITH A SLIGHT INCREASE MONDAY.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...DRS
LONG TERM...MY
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
358 AM EDT MON JUL 20 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM EDT MON JUL 20 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A WNW FLOW ALOFT
ALONG THE CNDN BORDER E OF AN UPR RDG OVER THE ROCKIES. SHRTWV AND
ASSOCIATED SFC LO EMBEDDED IN THIS FLOW ARE MOVING THRU NW
ONTARIO...WITH ATTENDANT SFC COLD FNT STRETCHING INTO MN. SOME ISOLD
SHOWERS ARE PRESENT JUST AHEAD OF THIS FNT AND MOVING THRU NW LK SUP
TOWARD THE KEWEENAW. BUT WITH AN ABSENCE OF MSTR INFLOW INTO THE
SHRTWV AND NOCTURNAL COOLING...THESE SHOWERS HAVE TENDED TO DIMINISH
WITH TIME TO THE S OF SHARPER DPVA/DEEP LYR QVECTOR CNVGC PASSING TO
THE N CLOSER TO THE SHRTWV TRACK. OTRW...STEADY WSW WINDS AHEAD OF
THE FNT ARE RESULTING IN WELL ABV NORMAL TEMPS EARLY THIS MRNG.
MAIN FCST CONCERNS IN THE SHORT TERM WL BE ON POPS TODAY ASSOCIATED
WITH APRCHG COLD FNT AS WELL AS GUSTY WINDS.
TODAY...SHRTWV MOVING THRU NW ONTARIO JUST N OF LK SUP IS FCST TO
MOVE QUICKLY ESEWD TO NEAR THE QUEBEC/ONTARIO BORDER BY 00Z THIS
EVNG. ATTENDANT COLD FNT IS PROGGED TO SWING THRU THE CWA...REACHING
THE SE ZNS ARND 18Z BEFORE CONTINUING AWAY TO THE SE IN THE AFTN.
WHILE THERE MAY BE SOME ISOLATED SHOWERS THIS MRNG OVER MAINLY THE
NRN TIER CLOSER TO THE SHRTWV TRACK/CORE OF SHARPER FORCING...EXPECT
A MAINLY DRY FROPA BECAUSE THE TIMING WL BE AHEAD OF THE FULL IMPACT
OF DAYTIME HEATING. A BIT CONCERNED THE LATER ARRIVAL EARLY THIS
AFTN OVER THE SE CWA WITH SOME ENHANCED LLVL CNVGC WITH LK BREEZE
OFF LK MI COULD RESULT IN SOME ISOLD SHOWERS/TS THERE AS HINTED AT
BY SOME OF THE HIER RES MODELS...SO DID MENTION SOME SCHC POPS IN
THIS AREA BEFORE MORE VIGOROUS DRYING AND THE ARRIVAL OF LARGER
SCALE DNVA/DEEP LYR QVECTOR DVGC ENDS THE PCPN CHCS BY LATE AFTN.
EXPECT SOME GUSTY WINDS AGAIN TODAY AHEAD OF AND FOLLOWING THE COLD
FROPA WITH H925 WSW WINDS UP TO 25-30 KTS SHIFTING TO THE WNW IN THE
AFTN. EXPECT THE HIEST MAX TEMPS INTO THE 80S OVER THE SCNTRAL. COOL
AIR ADVECTION IN THE WAKE OF THE FROPA WITH H85 TEMPS PROGGED TO
FALL TO NEAR 10C OVER THE NW CWA BY 00Z WL LIMIT THE DAYTIME DIURNAL
TEMP RISE TO THE NW.
TNGT...ANOTHER SHRTWV/SOME MID LVL MSTR ARE FCST TO SWING SE INTO
THE UPR LKS WITHIN DEEPENING UPR TROF. WHILE THERE MAY BE SOME CLDS
ACCOMPANYING THIS DISTURBANCE...NONE OF THE MODELS SHOW ANY PCPN
OVER UPR MI. WL MAINTAIN A DRY FCST DURING PERIOD OF NOCTURNAL
COOLING. OVERNGT LOWS WL BE QUITE A BIT LOWER THAN THIS MRNG WITH
SOME UPR 40S AT SOME OF THE COOL SPOTS. BUT STEADY NW WINDS WL TEND
TO LIMIT THE TEMP DROP.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 340 AM EDT MON JUL 20 2015
IMPACTS...NO SIGNIFICANT IMPACTS ARE WITHIN PREDICTABLE RANGE.
POSSIBILITY FOR STRONG TO SEVERE STORMS OVER PARTS OF THE REGION
LATE FRI INTO EARLY SAT...BUT STILL VERY UNCERTAIN ON THAT ASPECT.
MAY SEE A LIGHT SHOWER OR TWO ON TUE AFTERNOON AS A SHORTWAVE MAY
PASS THROUGH...BUT WILL LEAVE THE FORECAST DRY FOR NOW GIVEN LIMITED
COVERAGE/PRECIP AMOUNT/CONFIDENCE.
MAY SEE SHOWERS AND THUNDERSTORMS ALONG AND/OR NEAR THE WI BORDER
LATE WED INTO THU NIGHT AS MODELS SHOW A WARM FRONT MOVING INTO THE
AREA FROM THE SW ALONG WITH MOISTURE ADVECTION. WILL KEEP POPS SW OF
THE CWA ON WED...BUT WILL CONTINUE TO BRING SLIGHT CHANCE POPS INTO
AREAS ALONG THE WI BORDER WED NIGHT AND THU AS THE FRONT SLOWLY
MOVES NE. TIMING/LOCATION MAY BE CHANGED IF ANY DISTURBANCES FORM
THAT CAUSE THE FRONT/MOISTURE ADVECTION TO SURGE FARTHER N.
THE DISTURBANCE THAT THE WARM FRONT IS TIED TO WILL MOVE ACROSS
MANITOBA CANADA AND HUDSON BAY FRI INTO SUN...DRAGGING A SFC
TROUGH/COLD FRONT THROUGH THE AREA. DEFINITELY SOME DIFFERENCES
BETWEEN MODELS WITH THIS SYSTEM...WITH THE GFS BEING STRONGER AND
CONSIDERABLY FARTHER S THAN THE ECMWF. WILL USE CONSENSUS GUIDANCE
GIVEN THE UNKNOWNS INVOLVED...WHICH WILL SHOW SHOWERS AND
THUNDERSTORMS MOVING W TO E ACROSS THE CWA FROM LATE FRI THROUGH
SAT. SUN LOOKS DRY FOR NOW.
TEMPS WILL BE COOLEST TUE AND WED WITH NEAR TO SLIGHTLY BELOW NORMAL
TEMPS EXPECTED. AN UPPER RIDGE MOVES OVER THE AREA LATE IN THE WEEK
AHEAD OF THE CANADIAN DISTURBANCE...LEADING TO NEAR NORMAL TEMPS THU
AND ABOVE NORMAL TEMPS FRI THROUGH SUN. LOOKS LIKE UPPER RIDGING W
OF THE REGION IS FOR THE MOST PART HERE TO STAY THROUGH THE END OF
JULY...WITH ABOVE NORMAL TEMPS. CFS ALSO POINTS TO ABOVE NORMAL
TEMPS THROUGH MOST OF THE REST OF THE MONTH...WITH BELOW NORMAL
TEMPS TO START AUGUST OFF.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 122 AM EDT MON JUL 20 2015
VFR CEILINGS AND VIS WILL PREVAIL THROUGH THE PERIOD. LLWS IS
EXPECTED AT KIWD AND KSAW OVERNIGHT AS A LOW-LEVEL WIND MAX MOVES
OVER THE AREA. WINDS WILL INCREASE AGAIN AT THE SURFACE LATER
TONIGHT AT KCMX AND ACROSS ALL OF THE TAF SITES ON MONDAY IN THE
WAKE OF A MAINLY DRY COLD FRONTAL PASSAGE. STRONGEST WINDS WILL BE
AT KCMX WHERE WIND GUSTS WILL BE OVER 30 KTS FROM LATE MORNING INTO
MID AFTERNOON ON MONDAY. WINDS WILL DIMINISH MONDAY EVENING WITH
LOSS OF DIURNAL MIXING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 340 AM EDT MON JUL 20 2015
LOW PRESSURE FROM W ONTARIO TO JUST NW OF JAMES BAY WILL SWING INTO
S HUDSON BAY AND W QUEBEC TODAY WHILE DRAGGING A TROUGH ACROSS LAKE
SUPERIOR. WITH THE TIGHT PRESSURE GRADIENT...25KT WINDS WILL REMAIN
POSSIBLE ACROSS LAKE SUPERIOR.
A LARGE AREA OF HIGH PRESSURE FROM S CENTRAL CANADA THROUGH THE
CENTRAL PLAINS STATES TONIGHT WILL SLOWLY EDGE E...AND BUILD ACROSS
THE UPPER GREAT LAKES THROUGH THURSDAY...WITH WINDS RETURNING TO
AROUND 20KTS OR LESS. VERY PATCHY FOG /MAINLY N/ WILL ALSO DIMINISH
MONDAY. EXPECT A N PLAINS LOW THURSDAY NIGHT TO SHIFT TO N ONTARIO
BY THE END OF THE DAY FRIDAY...WITH A TROUGH PUSHING ACROSS
MINNESOTA AND W LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...VOSS
MARINE...TITUS
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1231 AM CDT MON JUL 20 2015
.UPDATE...
ISSUED AT 955 PM CDT SUN JUL 19 2015
SHOWERS ARE DEVELOPING ALONG AND JUST AHEAD OF THE COLD FRONT THAT
HAS REACHED KOOCHICHING AND NORTHERN ST. LOUIS COUNTIES ATTM.
LATEST HRRR HAS SHOWERS CONTINUING TO ACCOMPANY THE FRONT AS IT
PROGRESSES THROUGH THE AREA TONIGHT. HAVE BUMPED UP THE POPS OR
ADDED POPS TO ACCOUNT FOR THIS TREND.
UPDATE ISSUED AT 736 PM CDT SUN JUL 19 2015
A FEW SHOWERS ARE MOVING THROUGH THE BWCAW AHEAD OF A COLD FRONT.
SOME ISOLD THUNDERSTORMS ARE JUST N OF THE CANADIAN BORDER AND MAY
CLIP NORTH CENTRAL INTO NE MN THIS EVENING. INSTABILITY APPEARS TO
DECREASE CONSIDERABLY AFTER 03Z AND JUST HAVE A MENTION OF
SHOWERS. MADE OTHER MINOR TWEAKS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 324 PM CDT SUN JUL 19 2015
THE FOCUS FOR TONIGHT AND MONDAY WILL BE A COLD FRONT THAT WILL
DROP SOUTHWARD ACROSS THE NORTHLAND. AN AREA OF SHOWERS WAS
CURRENTLY MOVING TOWARD LAKE OF THE WOODS OR A BIT NORTH OF THERE.
THE SHOWERS WERE DROPPING TO THE EAST SOUTHEAST AND MAY BRUSH
PORTIONS OF THE INTERNATIONAL BORDER REGION DURING THE EVENING.
SOME MARGINAL INSTABILITY HAD DEVELOPED ACROSS SOUTH CENTRAL
CANADA AND THE BORDER REGION. AS A RESULT...WE COULD SEE SOME
LIMITED SHOWERS AND THUNDERSTORMS OVERNIGHT...MAINLY ACROSS THE
NORTH AND NORTHEAST. COOLER AIR WILL INFILTRATE THE REGION LATER
TONIGHT AND MONDAY...ALTHOUGH TEMPERATURES WILL NOT BE TOO MUCH
COOLER BEHIND THIS FRONT. WILL ALSO CARRY A SMALL POP IN THE FAR
NORTH AND NORTHEAST INTO MONDAY.
GUSTY NORTH TO NORTHWEST WINDS ARE EXPECTED TO DEVELOP ON
MONDAY...AS HIGH PRESSURE PUSHES INTO THE DAKOTAS BEHIND THE
FRONT. TEMPERATURES WILL LARGELY BE IN THE 70S WITH SOME LOWER 80S
IN THE SOUTH/SOUTHEAST.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 324 PM CDT SUN JUL 19 2015
TUESDAY...HIGH PRESSURE WILL MOVE INTO THE UPPER MIDWEST...PROVIDING
THE NORTHLAND WITH CLEAR SKIES. HIGHS SHOULD RANGE BETWEEN THE
MIDDLE 70S TO NEAR 80 DEGREES.
WEDNESDAY AND WEDNESDAY NIGHT...AN UPPER LEVEL RIDGE IN THE NORTHERN
PLAINS WILL BEGIN TO SHIFT INTO THE UPPER MIDWEST...MEANING A WARMER
DAY FOR THE NORTHLAND. A WARM FRONT MIGHT SET UP NEAR THE SOUTHERN
AND WESTERN FORECAST AREA...AND COULD HELP DEVELOP SHOWERS AND
THUNDERSTORMS. THE GEM AND GFS ARE THE MOST AGGRESSIVE WITH PCPN
WITH THE WARM FRONT. HIGHS SHOULD RANGE FROM THE UPPER 70S TO LOW
80S.
THURSDAY...THE UPPER LEVEL RIDGE WILL SHIFT INTO THE UPPER MIDWEST.
THERE ARE LOW CHANCES OF SHOWERS AND STORMS OVER THE NORTHERN AND SE
FORECAST AREA.
FRIDAY...THE GFS/ECMWF/GEM ARE IN FAIRLY GOOD AGREEMENT THAT A
TROUGH WILL MOVE THROUGH THE NORTHLAND AND BRING SHOWERS AND
THUNDERSTORMS. INCREASED PCPN CHANCES BASED ON THE MODEL AGREEMENT.
SATURDAY...HIGH PRESSURE WILL LIKELY MOVE INTO THE PLAINS OR UPPER
MIDWEST IN THE WAKE OF THE TROUGH PASSAGE ON FRIDAY. SATURDAY WILL
LIKELY BE DRY...BUT THERE ARE LOW PCPN CHANCES IN THE FORECAST TO
ACCOUNT FOR THE POTENTIAL THAT THE TROUGH PASSAGE SLOWS DOWN IN
SUBSEQUENT MODEL RUNS. HIGHS WILL LIKELY BE IN THE LOW 80S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1231 AM CDT MON JUL 20 2015
A COLD FRONT WILL PASS THROUGH DLH/BRD/HYR BY 09Z AND BE
ACCOMPANIED BY SHOWERS. EXACT TIMING IS DIFFICULT AND HAVE USED A
VCSH MENTION. WITH FROPA...WINDS TURN TO THE WEST OR NORTHWEST.
AFTER 12Z...GUSTY NW WINDS WILL AFFECT ALL TERMINALS. VFR IS
FORECAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 57 78 56 79 / 0 0 0 10
INL 51 75 49 79 / 0 0 0 0
BRD 54 81 57 83 / 0 0 20 20
HYR 53 77 53 79 / 0 0 0 20
ASX 57 78 54 78 / 0 0 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
UPDATE...GSF
SHORT TERM...DAP
LONG TERM...GROCHOCINSKI
AVIATION...GSF
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
333 AM CDT MON JUL 20 2015
.SHORT TERM: (THROUGH LATE THIS AFTERNOON)
ISSUED AT 316 AM CDT MON JUL 20 2015
CONVECTION TRENDS ARE THE PRIMARY FOCUS FOR TODAY`S FORECAST.
LATEST SHORT RANGE GUIDANCE INCLUDING THE RAP, NAM, AND TO A
LESSER EXTENT THE HRRR SHOW THE LINE OF BACKBUILDING THUNDERSTORMS
CURRENTLY OVER SOUTH-CENTRAL MISSOURI CONTINUING AND SLOWLY MOVING
EAST-NORTHEAST THROUGH THE EARLY AND MID MORNING HOURS. THE RAP
SEEMS TO BE HANDLING THIS BEST WITH MASS FIELDS PICKING UP THE
CONVECTION PRETTY WELL AT THIS TIME. NOT SURE HOW FAR EAST-
NORTHEAST THE STORMS WILL GET THIS MORNING...BUT HEAVY RAIN OVER
OUR EASTERN OZARK COUNTIES LOOKS LIKELY SO HAVE EXPANDED THE FLASH
FLOOD WATCH ACCORDINGLY. THE AREA OF STORMS NOW MOVING INTO WEST
CENTRAL/NORTHWEST MISSOURI WILL FURTHER COMPLICATE THE FORECAST.
SHOULD SEE THAT AREA GRADUALLY DIMINISH THIS MORNING AS THE LOW
LEVEL JET WEAKENS, BUT I DON`T THINK IT WILL TOTALLY FALL APART.
SHOULD SEE REDEVELOPMENT IN THE VICINITY OF THE MCV THIS AFTERNOON
AS DIURNAL HEATING REINVIGORATES CONVECTION. COVERAGE IS
UNCERTAIN AT THIS TIME, BUT THINK AT LEAST 40-50 POPS ARE
WARRANTED THIS AFTERNOON.
SECOND CONCERN IS POTENTIAL FOR HEAT INDEX VALUES IN EXCESS OF 100
DEGREES AGAIN TODAY. THIS SEEMS LESS LIKELY THAN PREVIOUS DAYS DUE
TO EXTENSIVE CLOUD COVER FROM CONVECTIVE DEBRIS AND AFTERNOON
THUNDERSTORMS. THOUGH FORECAST HEAT INDEX VALUES COME VERY NEAR
100 DEGREES (AND I CANNOT RULE OUT THERE WON`T BE SOME 100+ DEGREE
READINGS IN A FEW PLACES THIS AFTERNOON), FEEL THERE ARE TOO MANY
FACTORS AGAINST WIDESPREAD 100+ HEAT INDEX VALUES TO ISSUE ANY
HEADLINES AT THIS TIME.
CARNEY
.LONG TERM: (TONIGHT THROUGH SUNDAY)
ISSUED AT 333 AM CDT MON JUL 20 2015
AT THE START OF THE PERIOD TONIGHT, IT LOOKS LIKE THE HIGHEST PROBS
FOR RAIN WILL BE FOR AREAS NEAR I-70 AND INTO SOUTHEAST MO WITH WHAT
SHOULD BE MUCH MORE DIURNALLY DEPENDENT SCATTERED CONVECTION FURTHER
TO THE NORTH. ANOTHER COLD FRONT WILL MOVE THRU OUR REGION THIS
EVENING AND WILL, OVER TIME, SUPPRESS THE MORE WIDESPREAD SHRA/TSRA
OVER OUR SOUTHERN FORECAST AREA TO THE SOUTH WHILE THE NORTHERN
SCATTERED CONVECTION WILL LIKELY DISSIPATE.
HIGH PRESSURE WILL THEN BE THE DOMINANT INFLUENCE OVER MOST OF OUR
REGION TUESDAY MORNING THRU WEDNESDAY AFTERNOON. ENOUGH DRY AIR IS
EXPECTED TO BUILD IN MOST AREAS TO RESULT IN DRY WX WITH NIGHTTIME
MIN TEMPS POSSIBLY CLIPPING THE 50S NORTH OF I-70 WITH LOW 60S
EXPECTED MOST ELSEWHERE. MAX TEMPS ARE EXPECTED TO BE A RELATIVELY
BENIGN LOW-MID 80S. UPPER LEVEL DISTURBANCES ARE ANTICIPATED TO
HAVE JUST ENOUGH MOISTURE TO WORK WITH AS THEY TRAVERSE ACROSS FAR
SOUTHERN MO AND SOUTHERN IL TO RESULT IN CONTINUED CHANCES FOR RAIN
THIS PERIOD.
THE OLD FRONT TO THE SOUTH IS EXPECTED TO PUSH BACK TO THE NORTH
WEDNESDAY NIGHT FOR INCREASING RAIN CHANCES AREAWIDE. AT THIS
POINT...THERE IS GOOD MODEL CONSENSUS ON AMPLIFICATION UPSTREAM TO
THE ALREADY EXISTING MID AND UPPER LEVEL NW FLOW THAT IT LOOKS
LIKE WHERE THE FRONT WINDS UP EARLY THURSDAY MAY BE WHERE IT STAYS
FOR THE REMAINDER OF THE WEEK...RESULTING IN PERSISTENT RAIN CHANCES
FOR LATE WEEK. THE OTHER SOLUTION...WHICH WAS FAVORED UNTIL
RECENTLY...WAS THE FRONT PUSHING NORTH BRIEFLY AS A WARM FRONT...BUT
THE MODELS HAVE BEEN GRADUALLY BACKING AWAY FROM THIS SCENARIO OVER
THE PAST FEW DAYS.
THE AMPLIFIED UPPER LEVEL HIGH TO OUR WEST IS THEN EXPECTED TO
PERSIST THRU THE UPCOMING WEEKEND...AND WHILE TEMPS SHOULD BOUNCE
BACK...THEIR LIKELIHOOD OF GETTING MUCH ABOVE AVERAGE IS LOOKING
SLIMMER BY THE DAY.
TES
&&
.AVIATION: (FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 639 PM CDT SUN JUL 19 2015
OUTFLOW BNDY CURRENTLY STRETCHES FROM KC REGION TO JUST S OF KJEF
TO KFAM AREA. BELIEVE THIS WILL BE THE FOCUS FOR TSRA THIS EVE.
EXPECT A TSRA COMPLEX TO DEVELOP ACROSS ERN KS OR WRN MO OVERNIGHT
AND MOVE EWD IMPACTING TERMINALS DURING THE PRE-DAWN AND INTO MID
MORNING HOURS. A BRIEF LULL MAY OCCUR DURING THE LATE MORNING
HOURS FOR SUS/CPS AND PERHAPS COU BEFORE ANOTHER ROUND BEING
POSSIBLE DURING THE AFTERNOON HRS. HOWEVER, THIS WILL GREATLY
DEPEND ON TIMING OF MORNING CONVECTION AND EXACT PLACEMENT...WHICH
MAY INSTEAD BE A MORE PROLONGED PERIOD OF STORMS BEFORE PUSHING S
OF THE TERMINALS. UIN CURRENTLY HAS THE BEST CHANCE FOR DEVELOPING
FG OVERNIGHT AND GOING FCST MAY NOT HAVE VSBYS LOW ENUF.
OTHERWISE, EXPECT VFR CONDITIONS OUTSIDE OF TSRA.
SPECIFICS FOR KSTL: EXPECT TSRA TO IMPACT TERMINAL AROUND SUNRISE
MONDAY WITH A LULL IN THE LATE MORNING INTO AFTERNOON BEFORE
ANOTHER ROUND POSSIBLE IN THE LATE AFTERNOON INTO EVE.
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...FLASH FLOOD WATCH UNTIL NOON CDT TODAY FOR AUDRAIN MO-BOONE MO-
CALLAWAY MO-COLE MO-CRAWFORD MO-FRANKLIN MO-GASCONADE MO-
IRON MO-JEFFERSON MO-KNOX MO-LEWIS MO-LINCOLN MO-MADISON MO-
MARION MO-MONITEAU MO-MONROE MO-MONTGOMERY MO-OSAGE MO-PIKE
MO-RALLS MO-REYNOLDS MO-SHELBY MO-ST. CHARLES MO-ST.
FRANCOIS MO-ST. LOUIS CITY MO-ST. LOUIS MO-WARREN MO-
WASHINGTON MO.
IL...FLASH FLOOD WATCH UNTIL NOON CDT TODAY FOR ADAMS IL-BOND IL-
BROWN IL-CALHOUN IL-GREENE IL-JERSEY IL-MACOUPIN IL-MADISON
IL-MONROE IL-MONTGOMERY IL-PIKE IL-ST. CLAIR IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
331 AM CDT MON JUL 20 2015
.SHORT TERM: (THROUGH LATE THIS AFTERNOON)
ISSUED AT 316 AM CDT MON JUL 20 2015
CONVECTION TRENDS ARE THE PRIMARY FOCUS FOR TODAY`S FORECAST.
LATEST SHORT RANGE GUIDANCE INCLUDING THE RAP, NAM, AND TO A
LESSER EXTENT THE HRRR SHOW THE LINE OF BACKBUILDING THUNDERSTORMS
CURRENTLY OVER SOUTH-CENTRAL MISSOURI CONTINUING AND SLOWLY MOVING
EAST-NORTHEAST THROUGH THE EARLY AND MID MORNING HOURS. THE RAP
SEEMS TO BE HANDLING THIS BEST WITH MASS FIELDS PICKING UP THE
CONVECTION PRETTY WELL AT THIS TIME. NOT SURE HOW FAR EAST-
NORTHEAST THE STORMS WILL GET THIS MORNING...BUT HEAVY RAIN OVER
OUR EASTERN OZARK COUNTIES LOOKS LIKELY SO HAVE EXPANDED THE FLASH
FLOOD WATCH ACCORDINGLY. THE AREA OF STORMS NOW MOVING INTO WEST
CENTRAL/NORTHWEST MISSOURI WILL FURTHER COMPLICATE THE FORECAST.
SHOULD SEE THAT AREA GRADUALLY DIMINISH THIS MORNING AS THE LOW
LEVEL JET WEAKENS, BUT I DON`T THINK IT WILL TOTALLY FALL APART.
SHOULD SEE REDEVELOPMENT IN THE VICINITY OF THE MCV THIS AFTERNOON
AS DIURNAL HEATING REINVIGORATES CONVECTION. COVERAGE IS
UNCERTAIN AT THIS TIME, BUT THINK AT LEAST 40-50 POPS ARE
WARRANTED THIS AFTERNOON.
SECOND CONCERN IS POTENTIAL FOR HEAT INDEX VALUES IN EXCESS OF 100
DEGREES AGAIN TODAY. THIS SEEMS LESS LIKELY THAN PREVIOUS DAYS DUE
TO EXTENSIVE CLOUD COVER FROM CONVECTIVE DEBRIS AND AFTERNOON
THUNDERSTORMS. THOUGH FORECAST HEAT INDEX VALUES COME VERY NEAR
100 DEGREES (AND I CANNOT RULE OUT THERE WON`T BE SOME 100+ DEGREE
READINGS IN A FEW PLACES THIS AFTERNOON), FEEL THERE ARE TOO MANY
FACTORS AGAINST WIDESPREAD 100+ HEAT INDEX VALUES TO ISSUE ANY
HEADLINES AT THIS TIME.
CARNEY
.LONG TERM: (MONDAY THROUGH NEXT SUNDAY)
ISSUED AT 327 PM CDT SUN JUL 19 2015
CONVECTION AND ATTENDANT HEAVY RAIN THREAT SHOULD BE ONGOING BY
EARLY MONDAY MORNING ALONG AND NORTH OF THE I-70 CORRIDOR (AND
ESPECIALLY WEST OF THE MISSISSIPPI RIVER), WITH THIS CONVECTION
ROLLING EAST/SOUTHEAST ACROSS THE REGION DURING THE DAY. FOR NOW
I`VE MAINTAINED A CLIMATOLOGICAL FLAVOR TO THE HEAVY RAIN THREAT
AND PRIMARILY KEPT THIS MENTION DURING THE MORNING. IT`S
CERTAINLY POSSIBLE SOME HEAVY RAIN WILL LINGER INTO THE AFTERNOON,
BUT WILL LET MID SHIFT GET A BETTER LOOK AT TRENDS BEFORE
EXPANDING FFA FURTHER IN EITHER AREA OR TIME.
NO REAL CHANGES TO GOING FORECAST THROUGH TUESDAY, AS 12Z
GUIDANCE CONTINUES TO INDICATE UPPER TROF DEEPENING OVER THE
NORTHEAST CONUS WHICH WILL ALLOW SECONDARY COLD FRONT TO DROP INTO
THE MID MISSISSIPPI VALLEY. THIS WILL GRADUALLY SUPPRESS THE
THUNDERSTORM THREAT SOUTHWARD WHILE IT ALSO USHERING COOLER AND
LESS HUMID AIR INTO THE FA WITH TIME. HOWEVER, THERE IS
CONSIDERABLE DISAGREEMENT IN THE SYNOPTIC SOLUTIONS REGARDING
THUNDERSTORM THREAT BY MIDWEEK, WITH GFS AND ECMWF MUCH FUTHER
NORTH THAT NAM ON WEDNESDAY. FOR NOW GONE WITH A BLEND OF
GUIDANCE, AND GENERALLY KEPT POPS IN THE CHANCE CATEGORY OVER
SOUTHERN SECTIONS OF THE FA.
MEDIUM RANGE SOLUTIONS ARE STILL FORECASTING REINTENSIFICATION OF
UPPER RIDGE ACROSS THE AREA DURING THE LATTER HALF OF THE WEEK,
BUT GUIDANCE CERTAINLY HINTS AT SOME THREAT OF CONVECTION EVEN AS
HEIGHTS BUILD OVER THE REGION. BECAUSE OF THE THREAT DID NOT GO
TOO EXTREME ON HIGH TEMPS, BUT IT SHOULD CERTAINLY MEAN A RETURN
OF HIGH DEWPOINTS/APPARENT TEMPS AFTER THE MID-WEEK RESPITE.
TRUETT
&&
.AVIATION: (FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 639 PM CDT SUN JUL 19 2015
OUTFLOW BNDY CURRENTLY STRETCHES FROM KC REGION TO JUST S OF KJEF
TO KFAM AREA. BELIEVE THIS WILL BE THE FOCUS FOR TSRA THIS EVE.
EXPECT A TSRA COMPLEX TO DEVELOP ACROSS ERN KS OR WRN MO OVERNIGHT
AND MOVE EWD IMPACTING TERMINALS DURING THE PRE-DAWN AND INTO MID
MORNING HOURS. A BRIEF LULL MAY OCCUR DURING THE LATE MORNING
HOURS FOR SUS/CPS AND PERHAPS COU BEFORE ANOTHER ROUND BEING
POSSIBLE DURING THE AFTERNOON HRS. HOWEVER, THIS WILL GREATLY
DEPEND ON TIMING OF MORNING CONVECTION AND EXACT PLACEMENT...WHICH
MAY INSTEAD BE A MORE PROLONGED PERIOD OF STORMS BEFORE PUSHING S
OF THE TERMINALS. UIN CURRENTLY HAS THE BEST CHANCE FOR DEVELOPING
FG OVERNIGHT AND GOING FCST MAY NOT HAVE VSBYS LOW ENUF.
OTHERWISE, EXPECT VFR CONDITIONS OUTSIDE OF TSRA.
SPECIFICS FOR KSTL: EXPECT TSRA TO IMPACT TERMINAL AROUND SUNRISE
MONDAY WITH A LULL IN THE LATE MORNING INTO AFTERNOON BEFORE
ANOTHER ROUND POSSIBLE IN THE LATE AFTERNOON INTO EVE.
&&
.PRELIMINARY POINT TEMPS/POPS:
SAINT LOUIS 91 72 85 66 / 60 50 10 10
QUINCY 86 64 80 61 / 60 40 5 5
COLUMBIA 88 68 84 64 / 70 40 5 10
JEFFERSON CITY 89 69 84 65 / 70 50 10 10
SALEM 89 72 85 62 / 50 50 10 10
FARMINGTON 90 72 85 64 / 50 60 30 20
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...FLASH FLOOD WATCH UNTIL NOON CDT TODAY FOR AUDRAIN MO-BOONE MO-
CALLAWAY MO-COLE MO-CRAWFORD MO-FRANKLIN MO-GASCONADE MO-
IRON MO-JEFFERSON MO-KNOX MO-LEWIS MO-LINCOLN MO-MADISON MO-
MARION MO-MONITEAU MO-MONROE MO-MONTGOMERY MO-OSAGE MO-PIKE
MO-RALLS MO-REYNOLDS MO-SHELBY MO-ST. CHARLES MO-ST.
FRANCOIS MO-ST. LOUIS CITY MO-ST. LOUIS MO-WARREN MO-
WASHINGTON MO.
IL...FLASH FLOOD WATCH UNTIL NOON CDT TODAY FOR ADAMS IL-BOND IL-
BROWN IL-CALHOUN IL-GREENE IL-JERSEY IL-MACOUPIN IL-MADISON
IL-MONROE IL-MONTGOMERY IL-PIKE IL-ST. CLAIR IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
1040 PM MDT SUN JUL 19 2015
UPDATED AVIATION SECTION
.DISCUSSION...
BOTH HRRR AND RUC ANALYSIS A BIT AGGRESSIVE IN
DEVELOPING SHOWERS ACROSS PORTIONS OF THE HI-LINE THIS EVENING.
MODELS CONTINUE TO BRING A WEAK BOUNDARY SOUTH ACROSS THE BORDER
OVERNIGHT BUT HAVE LOWERED POPS UNTIL AFTER MIDNIGHT, WHEN SHOWERS
ARE MORE LIKELY TO DEVELOP. TEMPERATURES LOOK GOOD.
&&
.AVIATION...
UPDATED 0440Z.
MID-LEVEL CLOUDS WILL CONTINUE TO INCREASE AHEAD OF A
BOUNDARY THAT WILL BRING A CHANCE OF SHOWERS TO THE HI-LINE AND
PORTIONS OF NORTH CENTRAL MONTANA OVERNIGHT. THE AIRMASS WILL BECOME
UNSTABLE AGAIN AFTER 18Z WITH SCATTERED AFTERNOON THUNDERSTORMS
DEVELOPING. VFR CONDITIONS PREVAIL WITH MVFR CONDITIONS POSSIBLE IN
THE VICINITY OF SHOWERS AND/OR THUNDERSTORMS ALONG WITH GUSTY
ERRATIC WINDS.
&&
.PREV DISCUSSION...ISSUED 257 PM MDT SUN JUL 19 2015
TONIGHT THROUGH TUESDAY...NORTHWEST FLOW ALOFT WILL CONTINUE
OVERNIGHT THROUGH MID-DAY MONDAY BEFORE SHORTWAVE RIDGING MOVES
OVER THE STATE. THIS FEATURE WILL BE WEAK AND TRANSIENT EXISTING
JUST LONG ENOUGH TO SWITCH THE FLOW ALOFT TO WESTERLY BEFORE THE
NEXT APPROACHING TROUGH BACKS IT AROUND TO THE SOUTHWEST AGAIN.
MODELS CONTINUE TO BRING A WEAK BOUNDARY SOUTHWARD INTO NORTH
CENTRAL MONTANA WITH ISOLATED TO SCATTERED SHOWERS DEVELOPING
ALONG THE HI-LINE OVERNIGHT. SCATTERED SHOWERS AND A FEW
THUNDERSTORMS CONTINUE THROUGH MONDAY MORNING BEFORE BECOMING
ENHANCED BY A DISTURBANCE ALOFT MONDAY AFTERNOON AND EVENING.
OVERNIGHT AIRMASS STABILITY IS EXPECTED TO DIMINISH THE SHOWERS
LATE MONDAY NIGHT THROUGH TUESDAY MORNING. HOWEVER, INSTABILITY IN
THE SOUTHWEST FLOW AHEAD OF THE NEXT TROUGH WILL TRIGGER ISOLATED
TO SCATTERED SHOWERS AND THUNDERSTORMS OVER SOUTHWEST MONTANA
TUESDAY AFTERNOON. HIGH TEMPERATURES ON MONDAY AND TUESDAY WILL
CLIMB 5 TO 10 DEGREES ABOVE SEASONAL AVERAGES. MPJ
TUESDAY NIGHT THROUGH SUNDAY...AN UPPER LEVEL LOW PRESSURE TROF WILL
MOVE OVER THE WEST COAST TUESDAY NIGHT. THIS WILL BRING A PERIOD OF
FALLING HEIGHTS ALOFT WITH INCREASING INSTABILITY. THE BEST CHANCE
FOR CONVECTION WILL BE OVER THE SOUTHWEST ZONES WHERE UNSETTLED
SOUTHWEST FLOW ALOFT WILL ALSO BRING ADDITIONAL MOISTURE INTO THE
AIRMASS. AN ASSOCIATED COLD FRONT WILL CROSS THE ROCKIES EARLY
WEDNESDAY AND PUSH ACROSS THE ZONES. THIS FRONT DOES NOT LOOK QUITE
AS STRONG AS EARLIER MODELS HAD FORECAST. THE TROF WILL BE
BROADENING AND MOVING SLOWLY AS IT CROSSES THE PACIFIC NORTHWEST
THURSDAY AND BY FRIDAY, AS IT MOVES OVER THE ZONES, FLOW ALOFT WILL
BE NEARLY ZONAL. A WEAK RIDGE WILL BUILD OVER THE ZONES FRIDAY NIGHT
BUT ANOTHER LOW PRESSURE TROF WILL BE APPROACHING THE WEST COAST AND
HEIGHTS ALOFT OVER THE ZONES WILL ALREADY BE DROPPING BY SATURDAY.
THE TROF WILL SLOWLY MOVE OVER THE PACIFIC NORTHWEST BY SUNDAY
NIGHT AND THE AIRMASS WILL BECOME MORE UNSETTLED BY THE VERY END
OF THE FORECAST PERIOD. ZELZER
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 57 87 57 90 / 10 30 20 10
CTB 53 84 52 85 / 20 30 10 10
HLN 60 89 60 92 / 10 20 20 20
BZN 53 87 53 89 / 10 20 20 10
WEY 42 74 43 76 / 10 10 10 30
DLN 51 83 52 85 / 10 20 20 20
HVR 56 87 56 93 / 30 20 30 10
LWT 55 84 56 89 / 20 20 20 20
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
WEATHER.GOV/GREATFALLS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
316 AM CDT MON JUL 20 2015
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 316 AM CDT MON JUL 20 2015
REGIONAL RADAR MOSAIC SHOWING A COUPLE AREAS OF CONVECTION TO
CONTEND WITH THIS MORNING. FIRST IS CLUSTER OF STORMS OVER SD
PUSHING INTO THE NRN CWA ALONG A COLD FRONT THAT IS PROGGED TO
PUSH DEEPER INTO THE CNTRL PLAINS LATER TODAY. MEANWHILE A LINE OF
STORMS WAS LIFTING ACROSS KS ON NOSE OF LLVL JET/THETA-E ADV.
LATEST HRRR/RAP13 ARE IN REASONABLE AGREEMENT AREAL COVERAGE WILL
INCREASE AS ACTIVITY MERGES EARLY THIS MORNING...BUT THEN QUICKLY
DISSIPATES BY LATE MORNING WHEN THE BNDRY MOVES SOUTH OF THE CWA.
THE HRRR IS ALSO SHOWING POTENTIAL FOR POST-FRONTAL REDEVELOPMENT
ALONG THE 850MB WARM FRONT/MID LYR AGEOSTROPHIC LIFT MAINLY OVER
THE SRN CWA LATER THIS AFTN. RELATIVELY MILD CONDITIONS ON TAP
THEN THROUGH AT LEAST WED AS AS COOLER AIR MASS REMAINS IN CONTROL
OVER THE REGION. GOING FCST HAS SMALL POPS IN PLACE OVER THE SRN
CWA WED NIGHT ASSOCIATED WITH A WARM FRONT LIFTING OUT OF KS/MO.
WITH LATEST MODELS STILL SUPPORTING POSSIBLE DEVELOPMENT...SEE
LITTLE REASON TO MAKE ANY CHANGES.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 316 AM CDT MON JUL 20 2015
OVERALL THE GFS/ECM/CMC MAY BE IN AGREEMENT IN REGARDS TO LARGE
SCALE FLOW EVOLVING TO A LOW AMPLITUDE RIDGE PATTERN ENCOMPASSING
THE CONUS HEADING INTO NEXT WEEKEND...BUT CONSIDERABLE DIFFERENCES
SEEN IN REGARDS TO SFC FEATURES/FROPA. THIS BEST DEPICTED ON SAT/06Z
WITH PCPN DEVELOPMENT PER THE GFS ASSOCIATED WITH A COLD FRONT
DROPPING INTO THE CNTRL PLAINS. ECM ON THE OTHER HAND AT THAT TIME
DEVELOPS PCPN ASSOCIATED WITH A WARM FRONT LIFTING OUT OF KS. GIVEN
THAT THE EVOLVING PATTERN IS NOT ALL THAT FAVORABLE FOR PCPN
ACTIVITY...HAVE TAKEN THE LIBERTY OF REMOVING POPS FROM MOST OF THE
EXTENDED PDS EXCEPT FOR FRIDAY NIGHT LEAVING TOKEN 20S IN PLACE.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1145 PM CDT SUN JUL 19 2015
OCCASIONAL MVFR CONDITIONS IN THUNDERSTORMS ARE POSSIBLE AT KOFK
BETWEEN 06Z AND 12Z AS STORMS TRACK SOUTHEAST THROUGH NORTHEAST
NEBRASKA. MORE STORMS PROGRESSING NORTHEAST FROM KANSAS WILL
APPROACH KLNK BY 09Z AND KOMA BY 11Z...AND AGAIN COULD PRODUCE
OCCASIONAL MVFR CONDITIONS. EXPECT SHOWERS OR STORMS TO MOVE
SOUTHEAST OF ALL TAF SITES BEFORE 18Z...LEAVING NORTH WINDS
BETWEEN 15 AND 25K FOR THE AFTERNOON WITH GRADUALLY SCATTERING
CLOUDS. CLEAR SKIES AND LIGHT NORTH WINDS ARE FORECAST BY 00Z AND
BEYOND AT ALL TAF SITES.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...DEE
LONG TERM...DEE
AVIATION...DERGAN
AREA FORECAST DISCUSSION
NWS RALEIGH NC
511 AM EDT MON JUL 20 2015
.SYNOPSIS...A RELATIVELY ACTIVE SUMMER PATTERN...NORTHWEST FLOW
ALOFT...WILL PREVAIL ACROSS THE REGION THROUGH NEXT WEEKEND AS AN
UPPER LEVEL RIDGE STRENGTHENS OVER THE CENTRAL PLAINS.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 400 AM MONDAY...
...HEAT ADVISORY REMAINS IN EFFECT THIS AFTERNOON...
CENTRAL NC REMAINS ON THE EAST NORTHEAST PERIPHERY OF AN UPPER LEVEL
RIDGE CENTERED OVER THE SOUTH-CENTRAL CONUS - AT THE SOUTHERN FRINGE
OF THE WESTERLIES IN WNW FLOW ALOFT. IN SUCH A PATTERN...A VARIETY
OF ADDITIONAL VARIABLES CAN INFLUENCE THE DEVELOPMENT/EVOLUTION (OR
LACK THEREOF) OF CONVECTION...INCLUDING UPSTREAM CONVECTION OR THE
REMNANTS THEREOF (MCV`S/OUTFLOW BOUNDARIES)...SMALL AMPLITUDE
BAROCLINIC WAVES AT THE SOUTHERN FRINGE OF THE WESTERLIES...LOW-
LEVEL MOISTURE ADVECTION...DEPTH/DEGREE OF MIXING...ETC. AS A
RESULT...CONFIDENCE IN CONVECTIVE CHANCES/COVERAGE/TIMING THIS
AFTERNOON AND EVENING IS BELOW AVERAGE.
H85 TEMPS OF 18-20C AND STRONG INSOLATION/MIXING CONTINUE TO SUGGEST
HIGHS IN THE MID/UPPER 90S THIS AFTERNOON. HOWEVER...CONFIDENCE IN
SFC DEWPOINTS...RELATIVE HUMIDITY AND HEAT INDICES REMAINS
UNCERTAIN. LOW-LEVEL THERMODYNAMIC PROFILES FCST BY THE GFS/NAM ARE
CONSIDERABLY DIFFERENT FOR THIS AFTERNOON. THE NAM SUGGESTS 16-18C
H85 DEWPOINTS OVER CENTRAL NC...WITH SFC DEWPOINTS RANGING FROM THE
MID 60S (NW) TO ~70F (E/SE). AS A RESULT...THE NAM SUGGESTS MODERATE
DESTABILIZATION AND HEAT INDICES AT/AROUND ADVISORY CRITERIA SOUTH
AND EAST OF THE TRIANGLE. THE GFS INDICATES H85 DEWPOINTS ~14C...
DEEPER MIXING...SFC DEWPOINTS IN THE LOWER 60S...MARGINAL
INSTABILITY LARGELY CONFINED TO THE WEST/NW PIEDMONT...AND LOWER
HEAT INDICES OF 100-103F SOUTH AND EAST OF THE TRIANGLE. SPC
MESOANALYSIS DATA INDICATES A DRY LOW-LEVEL AIRMASS IN PLACE OVER
CENTRAL NC EARLY THIS MORNING WITH H85 DEWPOINTS OF 12-15C (16-17C
ALONG THE COAST AND ALONG/WEST OF THE MOUNTAINS). THOUGH WEAK
WESTERLY FLOW SHOULD ALLOW BETTER LOW-LEVEL MOISTURE TO ADVECT INTO
PORTIONS OF THE WEST/SW PIEDMONT THIS AFTERNOON...THE AFOREMENTIONED
MESOANALYSIS DATA SUGGESTS THERMODYNAMIC PROFILES WILL BE CLOSER TO
THOSE DEPICTED BY THE GFS THAN THE NAM.
TWO SMALL AMPLITUDE WAVES (BAROCLINIC/MCV/OR A COMBINATION THEREOF)
WERE LOCATED UPSTREAM OF THE AREA THIS MORNING...ONE IN WV AND THE
OTHER ALONG THE WESTERN TN/KY BORDER. THE LATEST RAP GUIDANCE
SUGGESTS THE WAVE IN WV WILL TRACK EASTWARD THROUGH CENTRAL/
NORTHERN VA LATE THIS MORNING AND EARLY THIS AFTERNOON...WHILE THE
KY/TN WAVE TAKES A MORE UNCERTAIN COURSE (INTO A WEAKER FLOW REGIME)
EAST SOUTHEAST ACROSS SOUTHWEST NC AND UPSTATE SC LATE THIS
AFTERNOON. THE LATTER WAVE TRACKING INTO WESTERN NC/SC APPEARS MOST
LIKELY TO AID CONVECTIVE DEVELOPMENT THIS AFT/EVE GIVEN EXCELLENT
DIURNAL TIMING AND A TRACK WHICH TAKES IS THROUGH A MORE FAVORABLE
THERMODYNAMIC ENVIRONMENT. GIVEN UNCERTAINTY IN THERMODYNAMIC
PROFILES (AS MENTIONED ABOVE)...UNCERTAINTY IN THE PRECISE
TRACK/TIMING OF THE AFOREMENTIONED WAVES IN ADDITION TO THE
POTENTIAL CONTRIBUTION FROM MESOSCALE FORCING...WILL INDICATE A 20-
30% CHANCE OF CONVECTION...HIGHEST IN THE WEST/SW PIEDMONT AND FAR
NE COASTAL PLAIN. -VINCENT
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 430 AM MONDAY...
...HEAT ADVISORY WILL LIKELY BE NEEDED FOR PORTIONS OF CENTRAL NC...
FORECAST CHALLENGES WILL BE SIMILAR TO TODAY...ALBEIT WITH A BETTER
OVERALL POTENTIAL FOR CONVECTION AS THE WESTERLIES STRENGTHEN
/EXTEND FURTHER SOUTH/ IN RESPONSE TO AMPLIFICATION OF AN UPPER
LEVEL TROUGH OVER PORTIONS OF EASTERN CANADA...THE GREAT LAKES...AND
NEW ENGLAND. LATEST GUIDANCE SUGGESTS DRY CONDITIONS FOR MOST OF THE
DAY...WITH A RAPID INCREASE IN CONVECTIVE POTENTIAL AFTER 21Z AND
THE BEST OVERALL POTENTIAL BETWEEN LATE AFTERNOON AND MIDNIGHT (21-
04Z). EXPECT HIGHS SIMILAR TO TODAY...ALBEIT SLIGHTLY COOLER IN THE
FAR NW PIEDMONT. ANOTHER HEAT ADVISORY WILL LIKELY BE NEEDED...
PERHAPS ALONG/EAST OF THE HWY 1 CORRIDOR (I.E. INCLUDING THE
TRIANGLE)...DEPENDING ON LOW-LEVEL MOISTURE. -VINCENT
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 320 AM MONDAY...
MEDIUM RANGE MODELS ARE IN GENERAL AGREEMENT IN SHOWING A SURFACE
FRONT STALLING NEAR OR JUST TO THE SOUTH OF CENTRAL NC FROM MID TO
LATE WEEK... BEFORE SHIFTING FURTHER SOUTH OVER THE WEEKEND AS A
SURFACE HIGH BUILDS MORE AGGRESSIVELY IN FROM THE NORTH (AS IT
SHIFTS EASTWARD AND EVENTUALLY OFFSHORE) WHILE THE MID LEVEL TROUGH
AXIS OVER THE NORTHEAST PUSHES OFFSHORE. THIS SHOULD ALLOW FOR
MAINLY DIURNAL CHANCES FOR SHOWERS AND STORMS FROM MID TO LATE
WEEK... MAINLY ACROSS SOUTHERN PORTIONS OF THE AREA...INVOF THE
FRONT... WITH GENERALLY DRY WEATHER RETURNING FOR THE WEEKEND (SMALL
CHANCE OF CONVECTION ON SUNDAY... DEPENDING ON THE TIMING OF ANOTHER
NORTHERN STREAM S/W TRACKING ACROSS THE NORTHERN HALF OF THE
COUNTRY).
HIGH TEMPS DURING THE MEDIUM RANGE SHOULD BE NEAR NORMAL... WITH
HIGHS IN THE UPPER 80S TO LOWER 90S. LOW TEMPS WILL FOLLOW A SIMILAR
TREND... GENERALLY UPPER 60S NORTH TO LOWER 70S SOUTH.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 230 AM MONDAY...
24-HR TAF PERIOD: EXPECT VFR CONDITIONS TO PREVAIL THROUGH THE
MAJORITY OF THE TAF PERIOD...ASIDE FROM A SMALL POTENTIAL FOR
SHOWERS/STORMS LATE THIS AFT/EVE...PRIMARILY AT THE INT/GSO
TERMINALS...THOUGH POSSIBLY AT ANY TERMINAL (SEE NEAR TERM
DISCUSSION). EXPECT LIGHT/VARIABLE OR CALM WINDS TO BECOME WESTERLY
AT ~10 KT THIS AFTERNOON.
LONG TERM: WITH AN UPPER LEVEL RIDGE EXPECTED TO PERSIST OVER THE
CENTRAL CONUS AND AN EXTENDED PERIOD OF NW FLOW ALOFT DOWNSTREAM
ACROSS THE APPALACHIANS AND MID-ATLANTIC...EXPECT AN ACTIVE SUMMER-
TIME PATTERN TO PERSIST ACROSS THE REGION...WITH THE PRIMARY
AVIATION HAZARD ASSOCIATED WITH DIURNAL CONVECTION...THOUGH
NOCTURNAL CONVECTION CANNOT BE RULED OUT AT TIMES. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM 1 PM TO 7 PM EDT MONDAY FOR NCZ011-027-028-042-
043-077-078-085-086-088-089.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...VINCENT
LONG TERM...77
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1235 AM EDT MON JUL 20 2015
.SYNOPSIS...
HIGH HEAT AND HUMIDITY WILL CONTINUE THROUGH TUESDAY. ON WEDNESDAY
A COLD FRONT WILL ENTER THE AREA AND STALL FOR A FEW DAYS BRINGING
A BETTER COVERAGE OF SHOWERS AND THUNDERSTORMS AND A BREAK FROM
THE HEAT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 AM MONDAY...CONVECTION DIED 1-2 HOURS AGO AND THE REMNANT
MID AND UPPER LEVEL MOISTURE IS JUST ABOUT DONE RAINING ITSELF OUT
NOW. POPS HAVE BEEN REMOVED FOR THE REMAINDER OF THE NIGHT...AND
DEBRIS CLOUDINESS SHOULD ALSO DISSIPATE IN THE 2-4 AM TIMEFRAME.
WINDS ARE OVERALL LIGHTER THAN MODELS INDICATED LIKELY DUE TO
INTERFERENCE FROM THE SOUTHWARD MOVING CONVECTION EARLIER IN THE
NIGHT. IS THE SURFACE INVERSION WELL ENOUGH ESTABLISHED TO RESIST
THE MODEST LOW LEVEL JET THAT WOULD TRY TO ADD SOME MOMENTUM BACK
INTO THE BOUNDARY LAYER? I`M BETTING THE INVERSION WILL WIN WITH
LIGHT WINDS CONTINUING THROUGH DAYBREAK. I HAVE LOWERED LOW TEMP
FORECASTS BY 1-2 DEGREES AT MOST INLAND SITES WITH LITTLE CHANGE
NECESSARY ALONG THE COAST. DISCUSSION FROM 1030 PM FOLLOWS...
CLOUD TOPS ARE WARMING ON INFRARED SATELLITE IMAGERY AND THERE IS NO
LONGER ANY CLOUD TO GROUND OR EVEN IN CLOUD LIGHTNING NOTED IN THE
AREA. AND ALTHOUGH THIS TOOK TWO HOURS LONGER TO BE TRUE WHEN
COMPARED TO YESTERDAY THERE IS NO UPSTREAM CONVECTION ASSOC WITH THE
NEXT SHORTWAVE. THUS FEEL THAT LOCAL HI RES MODELS LIKE THE HRRR ARE
CORRECT IN KEEPING US RAIN-FREE FOR THE REST OF THE PERIOD. THE 00Z
OPERATIONAL WRF HAS COME IN GIVING SUPPORT TO THIS IDEA AS WELL IN
CONTRAST WITH ITS EARLIER RUN THAT HELD ON TO SOME LIGHT RAIN
SHOWERS INTO AT LEAST PART OF THE OVERNIGHT. THE REMAINDER OF THE
NIGHT WILL FEATURE RAIN OVER NWRN COUNTIES TIL ABOUT MIDNIGHT
FOLLOWED BY A THINNING VEIL OF DEBRIS CIRRUS. ANY FOG THAT DEVELOPS
IN AREAS THAT SEE RAIN WILL ONLY BE OF THE VARIETY OF CONCERN TO
AVIATION/FIRE WEATHER. DEWPOINTS IN THE LOW TO MID 70S WILL
APPROXIMATE THE MUGGY NIGHTTIME LOW TEMPERATURES.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...THE REGION WILL SPEND ONE LAST DAY ON THE
PERIPHERY OF A 5H RIDGE CENTERED OVER TX ON MON. TUE A 5H LOW OVER
EASTERN CANADA WILL EXPAND SOUTH...SUPPRESSING THE SOUTHERN CONUS
5H RIDGE. ALTHOUGH DEEP WEST TO NORTHWEST FLOW REMAINS IN PLACE
THROUGH THE PERIOD THE COMBINATION OF DEEP MOISTURE...PRECIPITABLE
WATER IS AROUND 2 INCHES EACH AFTERNOON...AND THE PIEDMONT
TROUGH/SEA BREEZE SHOULD GENERATE SOME ISOLATED AFTERNOON
CONVECTION. GFS AND NAM SHOW A WEAK SHORTWAVE PASSING EACH
DAY...BUT TIMING IS A LITTLE TOO EARLY BOTH MON AND TUE MEANING
LIMITED DIURNAL INSTABILITY. SUBSIDENCE AS THE WAVE IS EXITING
WILL WORK TO OFFSET CONVECTION DUE TO DIURNAL HEATING AND SURFACE
BOUNDARIES. STILL THINK SOME CONVECTION WILL DEVELOP EACH
AFTERNOON BUT COVERAGE WILL BE LIMITED TO SLIGHT CHC TO LOW CHC AT
BEST. ORGANIZED SEVERE IS HIGHLY UNLIKELY GIVEN THE LACK OF ANY
STRONG FEATURES BUT AN ISOLATED STRONG TO SEVERE STORM REMAINS A
POSSIBILITY.
BEST PRECIP CHANCES MAY BE AT THE END OF THE PERIOD...AHEAD OF
WEAKENING COLD FRONT DROPPING IN FROM THE NORTHWEST. ALTHOUGH THE
FRONT WILL BE ARRIVING LATE TUE NIGHT THERE WILL BE PLENTY OF
MOISTURE AHEAD OF THE BOUNDARY AND AT LEAST SOME LINGERING
INSTABILITY. DO NOT THINK WIDESPREAD PRECIP WILL DEVELOP BUT THINK
CHC POP IS WARRANTED TUE NIGHT...ESPECIALLY INLAND.
TEMPERATURES WILL REMAIN ABOVE CLIMO THROUGH TUE NIGHT. HIGHS WILL
BE IN THE MID TO UPPER 90S EACH AFTERNOON AWAY FROM THE PINNED SEA
BREEZE. COMBINATION OF DEEPER MOISTURE AND THE HEAT WILL RESULT IN
HEAT INDEX VALUES IN THE 105 TO 109 RANGE MON WITH POTENTIALLY
HIGHER VALUES IN PLACES ON TUE. BASED ON THE EXPECTED HEAT INDEX
VALUES MON HAVE ISSUED A HEAT ADVISORY FOR ALL ZONES...EVEN THE
COASTAL ZONES GIVEN THE EXPECTED LIMITED INLAND PENETRATION OF THE
SEA BREEZE.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 3 PM SUNDAY...AN EAST TO WEST FLATTER MID TO UPPER RIDGE
OVER THE SOUTH WILL BECOME MORE AMPLIFIED UP THE THROUGH THE
MIDWEST THROUGH MID TO LATE WEEK ALLOWING TROUGH TO DIG DOWN ALONG
THE EAST COAST. THEREFORE...A GENERAL WESTERLY FLOW ALOFT WED INTO
THURS WILL BEGIN TO VEER ON FRI BECOMING MORE N-NW BY FRI NIGHT
INTO SATURDAY. THE LATEST MODEL RUNS SHOW A WEAK FRONT PUSHING
SOUTHEAST THROUGH WED LEAVING AN AREA OF LOW PRESSURE AND TROUGH
LINGERING OVER OR JUST SOUTH OF AREA THURS INTO FRIDAY. BY
SATURDAY THE MID TO UPPER RIDGE BUILDS FAR ENOUGH TO THE NORTH
NORTHEAST INTO THE GREAT LAKES KEEPING MORE OF A DRIER NORTHERLY
FLOW ALOFT AND BETTER SUBSIDENCE AND DRY AIR THROUGH THE MID TO
UPPER LEVELS TO KEEP MOST CONVECTION AT BAY. THEREFORE WILL SHOW
GREATEST POPS COASTAL ON WED AS SEA BREEZE COMES AGAINST NW FLOW
BEHIND FRONT TO PRODUCE GREATEST CONVERGENCE CLOSER TO THE
COAST...THEN SHIFTING SOUTH INTO SC ON THURS INTO FRI AS BOUNDARY
LINGERS NEARBY. THEN DRIER AND RELATIVELY COOLER TEMPS BY NEXT
WEEKEND AS MID TO UPPER TROUGH DIGS DOWN AND TROUGH AXIS SHIFTS
OFF SHORE ALLOWING A DEEP N-NW FLOW TO SET UP. IF RIDGE DOES NOT
BUILD NORTHEAST INTO THE GREAT LAKES FAR ENOUGH AND WINDS STAY
MORE NW INSTEAD OF NORTHERLY ALOFT...THERE WILL BE A GREATER CHC
OF UPSTREAM CONVECTION/MCS OR SHORTWAVE ENERGY MAKING ITS WAY INTO
THE AREA LATE SAT INTO SUNDAY.
AS FOR TEMPS...WED WILL BEGIN THE END OF DANGEROUS HEAT AS LOW LEVEL
WINDS VEER AROUND WITH 850 TEMPS DOWN TO 18C BY WED AFTN AND
REMAINING AROUND THAT VALUE THROUGH THE WEEKEND. THE GRADIENT OF
DRIER VS MOISTER AIR WILL RUN MORE N-NW TO S-SE WITH PCP WATER
VALUES DROPPING DOWN CLOSER TO AN INCH OVER CENTRAL TO NORTHERN NC
AND REMAINING UP TO 2 INCHES OVER CENTRAL TO COASTAL SC ON WED SOUTH
OF FRONTAL BOUNDARY/TROUGH. THE SFC DEWPOINTS MAY NOT SEE AS GREAT A
CHANGE DEPENDING ON HOW FAR SOUTH THE SFC BOUNDARY ACTUALLY MAKES
IT. GFS SHOWS LOWER SFC DEWPOINTS BY WED INTO THURS MOVING INTO AREA
FROM THE NORTH BUT ECMWF SHOWS A GREATER CHANGE FOR NEXT WEEKEND.
OVERALL EXPECT TEMPS BACK DOWN CLOSER TO NORMAL VALUES OR POSSIBLY
BELOW WITH CLOUDS AND CONVECTION AFFECTING TEMPS AND POSSIBLE DRIER
AIR MOVING SOUTH INTO AREA.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 06Z...PATCHY LIGHT RAIN HAS DISSIPATED. WINDS THROUGH SUNRISE
BE VARIABLE...EXCEPT AT THE COASTAL TERMINALS WHERE WINDS WILL BE SW
AROUND 4 KT.
BR WILL DEVELOP WITH HIGHEST CONFIDENCE OF TEMPO IFR AT KFLO/KLBT DUE
TO MOIST SOILS FROM YESTERDAYS ACTIVITY. TEMPO MVFR CAN BE EXPECTED
AT
THE COASTAL TERMINALS ALTHOUGH CONFIDENCE IS NOT AS HIGH. AFTER
SUNRISE
VFR EXPECTED WITH LIGHT WEST WINDS. THE SEA BREEZE MOVES THROUGH THE
COASTAL TERMINALS BY LATE MORNING SHIFTING WINDS TO THE SSW...BUT
WESTERLY
WINDS ALOFT COULD DELAY PASSAGE TO MID AFTERNOON.
EXTENDED OUTLOOK...BRIEF MVFR POSSIBLE THROUGH THE PERIOD FROM
DIURNAL CONVECTION. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 AM MONDAY...WINDS NEAR THE BEACHES HAVE DROPPED TO LESS
THAN 10 KNOTS WHILE OUT AT THE FRYING PAN SHOALS BUOY WINDS ARE
BARELY REACHING 15 KNOTS. THIS IS LIGHTER THAN MOST OF THE SYNOPTIC
SCALE GUIDANCE INDICATES...BUT IS RIGHT IN LINE WITH THE LATEST RUC
AND HRRR OUTPUT. I HAVE REDUCED FORECAST WIND SPEEDS THROUGH THE
REST OF THE NIGHT WITH ATTENDANT REDUCTIONS IN SEA HEIGHT FORECASTS
AS WELL. LATEST BUOYS CLUSTERED NEAR CAPE FEAR SHOW NOTHING HIGHER
THAN ABOUT 3 FEET. DISCUSSION FROM 1030 PM FOLLOWS...
OUTFLOW FROM DYING CONVECTION INLAND MAY BRIEFLY DISRUPT THE
OTHERWISE SYNOPTIC SOUTHWESTERLY FLOW. NEXT FEW HOURS THIS MAY
EVEN MEAN A QUICK TURN TO THE W OR NW BUT FOR THE MOST PART THERE
MAY JUST BE A RELAXATION IN THE GRADIENT. ONCE THIS BOUNDARY WASHES
OUT (MIDNIGHT-1AM) IT WILL BE BACK TO THE INLAND TROUGH-BORNE
SOUTHWESTERLY FLOW.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...SOUTHWEST FLOW WILL CONTINUE OVER THE WATERS
THROUGH THE PERIOD WITH BERMUDA HIGH AND PIEDMONT TROUGH THE
DOMINANT FEATURES. LATE IN THE PERIOD A WEAK COLD FRONT WILL DROP
IN FROM THE NORTHWEST BUT WILL NOT REACH THE WATERS BEFORE THE END
OF THE PERIOD. SOUTHWEST FLOW ON MON WILL BE IN THE 10 TO 15 KT
RANGE...PEAKING AT A SOLID 15 KT IN THE EVENING. WINDS WILL BE
SLIGHTLY HIGHER TUE WITH SPEEDS AROUND 15 KT INCREASING TO 15 TO
20 KT IN THE EVENING. SEAS 2 TO 4 FT ON MON WILL RUN 3 TO 4 FT TUE
WITH POTENTIAL FOR SOME ISOLATED 5 FT NEAR 20 NM IN THE EVENING.
ALTHOUGH CANNOT RULE OUT A MARGINAL SCEC TUE EVENING/NIGHT
HEADLINES SEEM LIKE A LONG SHOT.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 3 PM SUNDAY...A WEAK FRONT WILL DROP SOUTH REACHING INTO
AREA WATERS ON WED. THE LATEST MODELS KEEP THIS BOUNDARY BISECTING
WATERS WITH SLIGHTLY STRONGER WINDS OUT OF THE SW-W SOUTH OF
BOUNDARY AND LIGHTER NORTHERLY FLOW BEHIND IT...MAINLY NORTH OF
CAPE FEAR. AS SEA BREEZE DEVELOPS...WINDS WILL BECOME MORE ON
SHORE THROUGH WED AND WILL REMAIN LIGHTER AND MORE VARIABLE WITH A
GENERAL EASTERLY FLOW THROUGH THURS INTO FRI. THE WEAKENING FLOW
WILL ALLOW LAND/SEA BREEZE TO DOMINATE THE WINDS WITH GREATER ON
SHORE FLOW EACH AFTN AND A LIGHT OFF SHORE FLOW OVERNIGHT HEADING
INTO THE WEEKEND. THIS LINGERING BOUNDARY WILL MEANDER ACROSS THE
WATERS WHILE IT WEAKENS FURTHER THROUGH THE PERIOD. OVERALL EXPECT
SEAS 2 TO 4 FT WITH A SLIGHT DOWNWARD TREND THROUGH WED AND SLIGHT
UPWARD TREND THURS INTO FRI IN AN ON SHORE EASTERLY FLOW.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...HEAT ADVISORY FROM 1 PM TO 7 PM EDT MONDAY FOR SCZ017-023-024-
032-033-039-053>056.
NC...HEAT ADVISORY FROM 1 PM TO 7 PM EDT MONDAY FOR NCZ087-096-099-
105>110.
MARINE...NONE.
&&
$$
NEAR TERM...MBB/TRA
SHORT TERM...III
LONG TERM...RGZ
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
439 AM EDT MON JUL 20 2015
.SYNOPSIS...
A PAIR OF COLD FRONTS WILL PUSH SOUTHEAST ACROSS THE REGION
TONIGHT AND ON TUESDAY. HIGH PRESSURE WILL BUILD OVER PENNSYLVANIA
DURING THE SECOND HALF OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
930 PM...
HEAT ADVISORY FOR SE HAS ENDED.
ONGOING CLUSTER OF SEVERE WEATHER ALONG I-80 CORRIDOR THIS MID
EVENING LOOKS LIKE IT WILL GRADUALLY WEAKEN OVER NEXT FEW HOURS.
WW443 CONTINUES FOR THIS REGION...BUT HAS BEEN SCALED BACK ALONG
NORTHERN BORDER WHERE THREAT HAS ENDED.
BEGAN TO TAPER POPS BACK GRADUALLY LATE THIS EVENING AND ESP
OVERNIGHT...THOUGH THREAT FOR SHOWERS/POSS A TSTM WILL PERSIST
UNTIL COLD FROPA.
6 PM...
EARLY CONVECTION WHICH POPPED UP IN THE HEAT OVER THE CENTRAL
MOUNTAINS HAVE DISSIPATED. OTHER THAN A FEW SPECKLES
ELSEWHERE...THE ONLY GAME IN TOWN IS NOW THE STORMS OVER THE FAR
NW. LOTS OF STORMS SEEM TO SPLIT AND LEAVE THE LEFT-MOVER AS THE
STRONGER CELL. SO HAIL IS ALSO A THREAT WITH THE WIND DAMAGE STILL
THE MAIN THREAT. HAIL MAY END UP MELTING DOWN SOME EVEN IF IT WAS
LARGE ALOFT DUE TO HOT TEMPS AND DEEP WARM CLOUD DEPTH. TWEAKS
MAINLY FOR TIMING AND PLACEMENT.
PREV...
SEVERE THUNDERSTORM WATCH #443 IS NOW IN EFFECT FOR THE NORTHERN
HALF OF CENTRAL PA THROUGH 11 PM EDT. PRELIMINARY CELLS FIRING
DUE TO DIURNAL DESTABILIZATION AND BOUNDARY LAYER THERMAL RIDGE
PUSHING EAST OF MY AREA. HOTTEST DAY OF SUMMER THUS FAR IN
PROGRESS WITH APPARENT TEMPS SURGING INTO THE 90S THROUGHOUT.
HEAT INDICES WILL TOP OUT BETWEEN 100F AND 104F ACROSS THE SUSQ
VALLEY.
VERY WARM ALOFT WITH BOUNDARY LAYER CAPPING OF EARLIER TOWERS
NOW DECREASING AS CIN ANALYSIS SHOWS DESTABLIZATION OCCURRING
OVER LAKE ERIE AND NORTHWEST PA. JUST ONE HOUR AGO...ELEVATED
HEAT SOURCE SHOWERS BRIEFLY SPROUTED OVER SOUTH MOUNTAIN BEFORE
MOVING OFF THE TERRAIN AND QUICKLY DISSIPATING. SIMILAR SHOWERS
TRYING TO GROW OVER PORTIONS OF THE CENTRAL MOUNTAINS...AND ARE
NOW OVERCOMING THE CAP. HRRR DOES DEVELOP AND PROPAGATE THIS
ISOLD TO SCT SHRA/TSRA AREA SIMILAR TO SAT EVENING ACTIVITY BEFORE
DISSIPATING IT WITH THE DECREASE IN DIURNAL HEATING BY 00Z.
MAIN ACTIVITY EXPECTED WITH APPROACHING SHORTWAVE/COLD FRONT FROM
THE EASTERN GLAKS THIS EVENING THROUGH LATE TONIGHT. NO REAL
CHANGES TO PREVIOUS THINKING...WITH NORTHERN AREAS STANDING THE
GREATEST THREAT OF STRONG TO LOCALLY SEVERE STORMS...AS THE PARENT
SHORTWAVE WILL LIFT WELL NORTH OF THE REGION THIS EVENING. FAR
SOUTHEAST MAY BE HARD PRESSED TO RAIN FROM THIS FRONT AS A RESULT
LATE TONIGHT...AS GREATER DISTANCE FROM THE WANING LG SCALE
FORCING ACCOMPANIES FROPA FURTHER SOUTH. THUS TAPERING POPS TO THE
SOUTHEAST WILL BE MAINTAINED.
COOLER/DRIER AIR IN WAKE OF COLD FRONT SHOULD MAKE SOME INROADS
ACROSS THE NW MTNS...WHERE LOWS IN THE L60S EXPECTED TONIGHT. THE
REST OF CENTRAL PA WILL REMAIN IN MUGGY AIR MASS FOR ANOTHER NIGHT
WITH LOWS BTWN 70-75F SOUTH OF I-80.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
STALLED OUT COLD FRONT NR THE MASON DIXON LINE WILL BE THE FOCUS
FOR SCT PM CONVECTION ON MONDAY. ELSEWHERE...ARRIVAL OF LOW PWAT
AIR ACROSS NORTHERN PA SHOULD ENSURE A DRY DAY. ENS MEAN 8H TEMPS
ARE SUPPORTIVE OF HIGHS FROM THE L80S OVR THE N MTNS...TO THE L90S
ACROSS THE LOWER SUSQ VALLEY.
DID NOT CHANGE MUCH ON THIS PERIOD. DID GO WITH A DRY FCST FOR THE
MORNING HOURS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HARD TO SEE A LOT GOING ON AFTER THIS EVENING...DUE TO THE LACK
OF SFC CONVERGENCE.
DID GO WITH SOME CHC POPS LATER MONDAY INTO TUE. HIGHEST CHC
ON TUE...AS SECONDARY FRONT DROPS SE.
AFTER THIS...LOOKING AT MAINLY DRY WEATHER WED INTO FRIDAY.
SOME MODELS LIKE THE GFS40 HAVE SOME SHOWERS IN THE SW ON THU.
LEFT FCST DRY FOR NOW.
MAIN CHANGE WAS TO LOWER TEMPS MORE FOR THE PERIOD WED INTO
FRIDAY. MAIN FACTORS ARE LOWER 500 MB HEIGHTS ON THE MODELS LATELY
ALSO THE TENDENCY FOR THE AIRMASS BEHIND COLD FRONTS TO BE COLDER
THAN FCST LATELY. ALSO THE WET GROUND.
MID SHIFT DID PUT SOME SHOWERS IN FOR THE FIRST PART OF THE
WEEKEND. SOME MODELS SHOW VERY STRONG WARM ADVECTION AND
DIRECTIONAL SHEAR INTO AT LEAST NW PA ON SUNDAY. EC NOT REALLY
SHOWING MUCH OF THIS. FOR NOW...DID CARRY SHOWERS INTO SUNDAY.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
ISOLATED SHOWERS WITH AN EVEN RARER TSTM STILL IMPACTING CENTRAL
PA EARLY THIS MORNING AHEAD OF AN APPROACHING COLD FRONT. BUT
ACTIVITY SIGNIFICANTLY DIMINISHED SINCE THE EVENING HOURS.
ATTENTION DURING THE PREDAWN HOURS WILL TURN TO DEVELOPMENT OF
FOG/MIST AND CIG RESTRICTIONS. MOST LIKELY AREAS FOR FOG WILL BE
ACROSS THE NORTHERN HALF WHERE RAIN OCCURRED /FROM KBFD-KUNV-
KIPT/. LIGHT SW FLOW AHEAD OF THE APPROACHING COLD FRONT WILL ALSO
BRING AN MVFR/IFR CLOUD DECK TO MAINLY WESTERN SECTIONS. THE SE
SHOULD REMAIN VFR...WITH JUST A BIT OF MVFR FOG POSS RIGHT AROUND
SUNRISE.
EXPECT RESTRICTIONS TO IMPROVE BETWEEN 12-15Z. MONDAY WILL BRING
MAINLY VFR CONDITIONS AS DRIER AIR WORKS IN FROM THE NW. BUT
SLIGHT CHANCE FOR A SHOWER OR TSTM WILL REMAIN ALONG THE SOUTHERN
TIER AND POSS VICINITY OF KMDT-KLNS WHERE DEWPOINTS REMAIN HIGH.
WINDS WILL REMAIN WESTERLY AND PICK UP TO NEAR 10 MPH DURING THE
DAY.
OUTLOOK...
TUE...ANOTHER COLD FRONT WILL BRING SCT SHOWERS/TSTMS. CIG
RESTRICTIONS LIKELY NW HALF...PRIMARILY VFR SE.
WED-FRI...MAINLY VFR. LOCAL A.M. FOG POSS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DEVOIR/RXR
NEAR TERM...DANGELO/DEVOIR/RXR
SHORT TERM...DEVOIR/MARTIN
LONG TERM...MARTIN
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
346 AM CDT MON JUL 20 2015
.DISCUSSION...
CURRENTLY...AT 3 AM AROUND THE MIDSOUTH TEMPERATURES RANGE FROM
THE MID 70S IN THE EAST TO THE LOWER 80S IN THE WEST. CURRENT
INFRARED SATELLITE IMAGERY DEPICTS CLOUDS MOVING INTO NORTHERN
REACHES OF THE FA ASSOCIATED WITH ONGOING CONVECTION OVER
SOUTHEAST MISSOURI...SOUTHERN ILLINOIS...AND WESTERN KENTUCKY.
THIS ACTIVITY IS MARCHING TOWARD THE MIDSOUTH AND WILL LIKELY
AFFECT NORTHERN COUNTIES THROUGH SUNRISE. H5 ANALYSIS DEPICTS A
HIGH PRESSURE CENTER LOCATED OVER WEST TEXAS...AND THE CONTINUED
WESTWARD MIGRATION OF THE FEATURE WILL ALLOW DAILY SHOWER AND
THUNDERSTORM CHANCES TO RETURN TO THE REGION.
A HEAT ADVISORY REMAINS IN EFFECT THROUGH 7 PM THIS EVENING WITH
TEMPERATURES TOPPING OUT ONCE AGAIN IN THE UPPER 90S AT MOST
LOCATIONS TODAY...LEADING TO HEAT INDICES IN EXCESS OF 105
DEGREES. UNCERTAINTY EXISTS IN REGARD TO THE ADVISORY AFTER THIS
EVENING...AND THUS THE DAY SHIFT WILL DETERMINE EXACTLY WHERE AND
FOR HOW LONG TO EXTEND. TEMPERATURES WILL COOL UNDER INCREASED
CLOUD COVER AND CONVECTION THROUGHOUT THE WEEK...THOUGH AREAS
PRIMARILY LOCATED IN NORTH MISSISSIPPI COULD SEE HEAT INDICES JUST
NEAR CRITERIA AT LEAST THROUGH WEDNESDAY.
WITH THE INFLUENCE OF THE RIDGE ABSENT FROM THE REGION...A COLD
FRONT WILL BEGIN TO APPROACH THE REGION...LEADING TO AN INCREASE
IN SHOWER AND THUNDERSTORM CHANCES. THESE CHANCES WILL GRADUALLY
INCREASE FROM NORTH TO SOUTH AS WE ADVANCE THE WEEK WITH THE
MIGRATION OF THE BOUNDARY SOUTH. TUESDAY THROUGH THURSDAY WILL
HOLD THE BEST PRECIPITATION CHANCES THIS WEEK AS THE BOUNDARY
REMAINS STATIONED IN THE VICINITY OF THE MIDSOUTH WITH SEVERAL
SUBTLE IMPULSES ALOFT INTERACTING WITH THE FEATURE. A FEW STORMS
COULD BE STRONG THIS WEEK WITH GUSTY WINDS AND HEAVY
RAIN...PARTICULARLY DURING THE AFTERNOON AND EVENING HOURS WHEN
THE GREATEST INSTABILITY IS REALIZED. ALONG WITH INCREASED
PRECIPITATION CHANCES COMES A RELIEF FROM THE OPPRESSIVE
HEAT...WITH TEMPERATURES RANGING FROM THE UPPER 80S TO MID 90S FOR
MUCH OF THE WEEK AFTER MONDAY.
CHANCES FOR PRECIPITATION WILL DECREASE LATE IN THE WEEK AND INTO
THE WEEKEND WITH TEMPERATURES SLOWLY INCREASING AS MODELS HINT AT
THE AMPLIFIED RIDGE BUILDING BACK INTO THE REGION.
ZDM
&&
.AVIATION...
06Z TAFS
LATE EVENING RADAR TRENDS AND SHORT TERM MODEL DATA SUGGESTS THE
SOUTHERN FRINGES OF TSRA COMPLEX IN SOUTHEAST MO MAY ENTER
NORTHEAST AR AND NORTHWEST TN DURING THE OVERNIGHT. IT MAY BE
CLOSE CALL IF THE HRRR IS CORRECT. NAM REMAINS FURTHER NORTH...
KEEPING MKL AND JBR DRY OVERNIGHT
WITH UPPER RIDGE RETROGRADING FURTHER ON MONDAY... ADDITIONAL
AFTERNOON TSRA WILL BE POSSIBLE NEAR THE TN RIVER... POSSIBLY
INTO THE MKL VICINITY.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI-
PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR DUNKLIN-PEMISCOT.
MS...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ALCORN-BENTON MS-
CALHOUN-CHICKASAW-COAHOMA-DESOTO-ITAWAMBA-LAFAYETTE-LEE MS-
MARSHALL-MONROE-PANOLA-PONTOTOC-PRENTISS-QUITMAN-
TALLAHATCHIE-TATE-TIPPAH-TISHOMINGO-TUNICA-UNION-YALOBUSHA.
TN...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR BENTON TN-CARROLL-
CHESTER-CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-
HARDIN-HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-
MCNAIRY-OBION-SHELBY-TIPTON-WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
1143 PM CDT SUN JUL 19 2015
.UPDATE...
UPDATED FOR 06Z AVIATION DISCUSSION BELOW.
&&
.PREV DISCUSSION... /ISSUED 845 PM CDT SUN JUL 19 2015/
DISCUSSION...
MINOR UPDATE MAINLY IN THE NORTHERN PORTION OF FORECAST AREA.
INCREASED POPS DUE TO STORMS IN MISSOURI...WHICH THE HRRR BRINGS
INTO THE MID-SOUTH OVERNIGHT. NAM ALSO HINTS AT SOME PRECIPITATION
OVER AREA TONIGHT. HRRR IS MORE AGGRESSIVE AND MUCH MORE OF THE
AREA COVERED. HOWEVER...ONLY RAISED POPS SLIGHTLY AND THUS ONLY
NORTHERN PORTION HAVE HIGH ENOUGH POPS TO MENTION PRECIPITATION IN
THE FORECAST. HAVE TO WATCH THIS CLOSELY.
HEAT ADVISORY STILL CONTINUES FOR THROUGH TOMORROW. THIS IS
BEGINNING TO LOOK LIKE A RARE EVENT FOR THE MID-SOUTH WITH
CONSECUTIVE DAYS OF HEAT ADVISORIES...AT LEAST ACCORDING TO DATA
FOUND THIS EVENING AT OFFICE...SEE CLIMATE SECTION FOR MORE
DETAILS. TLSJR
PREV DISCUSSION... /ISSUED 306 PM CDT SUN JUL 19 2015/
DISCUSSION...WATER VAPOR SATELLITE TRENDS THIS AFTERNOON PLACE AN
UPPER LEVEL RIDGE OVER THE SOUTHERN PLAINS AND LOWER MISSISSIPPI
VALLEY. MOST AREAS HAVE REMAINED RAIN FREE EXCEPT FOR A PORTION OF
WEST TENNESSEE NEAR SAVANNAH AND EXTREME NORTHEAST MISSISSIPPI
WHERE ISOLATED SHOWERS AND THUNDERSTORMS DEVELOPED AND QUICKLY
PUSHED OUT OF THE FORECAST AREA. VISIBLE SATELLITE TRENDS INDICATE
MOSTLY SUNNY TO PARTLY SUNNY SKIES ACROSS THE MID SOUTH DUE TO THE
DEVELOPMENT OF DIURNAL BASED CUMULUS FROM LATE MORNING. AS OF 2 PM
CDT...TEMPERATURES ACROSS THE MID SOUTH ARE IN THE LOWER TO MIDDLE
90S AT MOST LOCATIONS. HEAT ADVISORY POTENTIAL THROUGH EARLY THIS
WEEK AND INCREASED CONVECTIVE POTENTIAL CHANCES ARE THE CHALLENGES
IN THIS AFTERNOON/S FORECAST ISSUANCE.
AFTERNOON TEMPERATURES IN THE LOWER TO MIDDLE 90S COMBINED WITH
SURFACE DEWPOINTS IN THE LOWER TO MIDDLE 70S HAS RESULTED IN HEAT
INDEX READINGS REACHING OR EXCEEDING 105 DEGREES THIS AFTERNOON.
SOME CLOUD COVER HAS TEMPORARILY DROPPED HEAT INDEX READINGS BELOW
ADVISORY CRITERIA ACROSS PORTIONS OF THE MID SOUTH...BUT POTENTIAL
EXISTS FOR THESE AREAS TO SEE VALUES AT OR ABOVE 105 DEGREES AGAIN
BEFORE SUNSET.
MODELS CONTINUE TO INDICATE AN UPPER LEVEL RIDGE AXIS HOLDING IN
PLACE ACROSS MUCH OF THE MID SOUTH THIS EVENING BUT WILL WEAKEN
ACROSS AREAS NEAR THE KENTUCKY/MISSOURI BORDER LATE TONIGHT AND
NORTH OF I-40 ON MONDAY. SHEAR WILL CONTINUE TO REMAIN WEAK
OVERALL AND THINK ANY CONVECTIVE ACTIVITY WILL BE TRIGGERED BY
CONVECTIVE TEMPERATURES BEING REACHED...RESULTING IN THE
DEVELOPMENT OF RATHER DISORGANIZED PULSE TYPE THUNDERSTORMS.
TEMPERATURES AGAIN WILL BE HOT ON MONDAY AND HIGH SURFACE
DEWPOINTS IN THE LOWER TO PERHAPS MIDDLE 70S WILL RESULT IN HEAT
INDEX READINGS ONCE AGAIN REACHING OR EXCEEDING 105 DEGREES. THE
HEAT ADVISORY WILL REMAIN IN EFFECT FOR THE ENTIRE MID SOUTH
THROUGH AT LEAST 7 PM CDT MONDAY.
BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS WILL ARRIVE FOR
TUESDAY AS A WEAK COLD FRONT DROPS INTO THE LOWER MISSISSIPPI
VALLEY. HEAT INDEX READINGS MAY ONCE AGAIN APPROACH/EXCEED 105
DEGREES AND THE CURRENT HEAT ADVISORY MAY ONCE AGAIN NEED TO BE
EXTENDED IN TIME. WILL HOLD OFF FOR THE TIME BEING TO UNCERTAINTY
RELATED TO CONVECTIVE COVERAGE AND ITS AFFECT ON TEMPERATURES.
BEST CHANCES FOR SHOWERS AND THUNDERSTORMS WILL PERSIST THROUGH
THURSDAY. LONG TERM MODELS INDICATE THE UPPER LEVEL RIDGE AXIS
WILL TRY TO BUILD BACK IN ACROSS THE LOWER MISSISSIPPI VALLEY WITH
THE BEST CHANCES FOR SHOWERS AND THUNDERSTORMS BEING SLIGHTLY EAST
OF THE MID SOUTH TOWARDS NEXT WEEKEND.
CJC
&&
.CLIMATE...
LOOKING AT DATA FROM 2004 TO TODAY WHEN THE MEMPHIS OFFICE ISSUED
EITHER A HEAT ADVISORY OR EXCESSIVE HEAT WARNING. THE FOLLOWING
TABLES SHOW THE TOP SIX NUMBER OF DAYS IN A ROW A ADVISORY OR
WARNING WERE ISSUED. WE DON/T HAVE RECORDS OF HEAT INDEX VALUES
FOR ALL DAYS ACROSS THE MID-SOUTH SO USED THE ADVISORIES AND
WARNINGS.
FOR ALL THE MID-SOUTH (THAT IS ANYWHERE IN THE MID-SOUTH)
19 DAYS - JULY 29 - AUGUST 16, 2010
13 DAYS - JULY 26 - AUGUST 8, 2011
11 DAYS - JULY 16 - JULY 26, 2010
11 DAYS - JULY 26 - AUGUST 5, 2008
9 DAYS - JULY 18 - JULY 26, 2012
8 DAYS - JULY 12 - JULY 19, 2015 /TODAY/
8 DAYS - JULY 28 - AUGUST 5, 2012
8 DAYS - JUNE 18 - JUNE 25, 2010
8 DAYS - JULY 20 - JULY 27, 2005
WE SHOULD REACH THE TOP FIVE FOR THE AREA ON MONDAY.
LOOKING SPECIFICALLY AT MEMPHIS /SHELBY COUNTY/ IT IS ALREADY IN
THE TOP 5 FOR THE PAST 11 YEARS.
FOR SHELBY COUNTY
11 DAYS - JULY 26 - AUGUST 5, 2008
10 DAYS - JULY 30 - AUGUST 8, 2011
10 DAYS - AUGUST 7 - AUGUST 16, 2010
9 DAYS - JULY 18 - JULY 26, 2012
8 DAYS - JULY 12 - JULY 19, 2015 /TODAY/
8 DAYS - JULY 29 - AUGUST 5, 2010
8 DAYS - JUNE 18 - JUNE 25, 2010
&&
.AVIATION...
06Z TAFS
LATE EVENING RADAR TRENDS AND SHORT TERM MODEL DATA SUGGESTS THE
SOUTHERN FRINGES OF TSRA COMPLEX IN SOUTHEAST MO MAY ENTER
NORTHEAST AR AND NORTHWEST TN DURING THE OVERNIGHT. IT MAY BE
CLOSE CALL IF THE HRRR IS CORRECT. NAM REMAINS FURTHER NORTH...
KEEPING MKL AND JBR DRY OVERNIGHT
WITH UPPER RIDGE RETROGRADING FURTHER ON MONDAY... ADDITIONAL
AFTERNOON TSRA WILL BE POSSIBLE NEAR THE TN RIVER... POSSIBLY
INTO THE MKL VICINITY.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...HEAT ADVISORY UNTIL 7 PM CDT MONDAY FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI-
PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...HEAT ADVISORY UNTIL 7 PM CDT MONDAY FOR DUNKLIN-PEMISCOT.
MS...HEAT ADVISORY UNTIL 7 PM CDT MONDAY FOR ALCORN-BENTON MS-CALHOUN-
CHICKASAW-COAHOMA-DESOTO-ITAWAMBA-LAFAYETTE-LEE MS-MARSHALL-
MONROE-PANOLA-PONTOTOC-PRENTISS-QUITMAN-TALLAHATCHIE-TATE-
TIPPAH-TISHOMINGO-TUNICA-UNION-YALOBUSHA.
TN...HEAT ADVISORY UNTIL 7 PM CDT MONDAY FOR BENTON TN-CARROLL-
CHESTER-CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-
HARDIN-HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-
MCNAIRY-OBION-SHELBY-TIPTON-WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1105 PM CDT SUN JUL 19 2015
.AVIATION AND MESOSCALE UPDATE...FOR 06Z FORECAST
MESO CONVECTIVE SYSTEM HAS DEVELOPED IN SOUTHEAST MISSOURI. THIS
IN AREA OF 700 MBAR THERMAL TROUGH AND SHORT WAVE AS CAN BE SEEN
IN LATEST RUC RUN. HOW FAR SOUTHEAST THIS COMPLEX WILL GET IS IN
QUESTION SINCE IT WILL BE MOVING INTO AN AREA THAT IS CURRENTLY
CAPPED WITH TEMPS AROUND 11 DEGREE CELSIUS ALONG TENNESSEE/KENTUCKY
BORDER UNDERNEATH WARM UPPER LEVEL ANTICYCLONE AND AROUND 14
DEGREES ACROSS A GOOD PART OF ARKANSAS INTO SOUTHWESTERN TENNESSEE.
I DID NOTICE WHAT APPEARS TO BE A STATIONARY FRONT OR SOME TYPE OF
BOUNDARY FEATURE STRUNG OUT FROM CENTRAL MISSOURI EASTWARD TO
ALONG THE OHIO RIVER NORTH OF LOUISVILLE. NOT SURE HOW THIS
FEATURE EVOLVED BUT IT IS DEFINITELY THERE. WINDS ARE LIGHT
NORTHERLY NORTH OF THIS FEATURE AND LIGHT SOUTHERLY SOUTH.
DEWPOINTS CONTINUE TO POOL ACROSS SOUTHEAST MISSOURI AND FAR
WESTERN KENTUCKY AHEAD OF COMPLEX. H-TRIPLE-R WORKS COMPLEX DOWN
INTO FAR NORTHWEST MIDDLE TENNESSEE AROUND 09Z THE PLAYS IT OUT
TOWARD DAYBREAK. WILL BASE 06Z FORECASTS ON THIS SCENARIO AS IT
SEEMS REASONABLE AT THIS TIME.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 7 PM CDT MONDAY FOR TNZ005>009-023>030-
056>064-075-077-093>095.
&&
$$
BOYD
01
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
418 AM EDT MON JUL 20 2015
.SYNOPSIS...
A COLD FRONT EXTENDING FROM LAKE ONTARIO TO IOWA THIS MORNING WILL
MOVE SOUTH INTO THE REGION TODAY. A SECOND STRONGER FRONT WILL
PASS THROUGH THE REGION LATE TUESDAY. EXPECT PERIODS OF SHOWERS
AND THUNDERSTORMS AHEAD OF THE FRONTS...THEN DRY WEATHER WITH LESS
HUMID AND COOLER AIR BEHIND THE BOUNDARY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 400 AM EDT MONDAY...
500 MB SHORT WAVE MOVING INTO WEST VIRGINIA WILL BRING SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS INTO THE WESTERN COUNTY WARNING
AREA THIS MORNING. HRRR AND LOCAL WRF SHOWED SOME INDICATIONS THAT
PRECIPITATION MAY SURVIVE ACROSS THE NORTHERN COUNTY WARNING AREA
BUT OVERALL TREND WILL BE FOR SHOWERS AND THUNDERSTORMS TO WEAKEN
BEFORE 12Z/8AM.
WEST TO NORTHWEST SURFACE AND LOW LEVEL WIND EXPECTED TODAY WHICH
FAVORS DEVELOPMENT OF ADDITIONAL SHOWERS AND THUNDERSTORMS AGAIN
IN THE MOUNTAINS THIS AFTERNOON. WITH LEE TROUGHING IN
PLACE...FAR EASTERN PIEDMONT MAY ALSO HAVE BETTER COVERAGE.
WEST TO NORTHWEST WINDS WILL CREATE DOWNSLOPING AND MIXING BY THIS
AFTERNOON...ENOUGH TO LOWER DEW POINTS INTO THE 60S IN THE
FOOTHILLS AND KEEP THE HEAT INDEX EAST OF THE BLUE RIDGE FROM
REACHING ADVISORY LEVELS. NO HEAT ADVISORY PLANNED AT THIS TIME.
MORE ORGANIZED SHOWERS AND THUNDERSTORMS WILL DEVELOP AHEAD OF
THE FRONT ACROSS THE OHIO VALLEY THIS AFTERNOON. THESE STORMS WILL
MOVE INTO THE WESTERN COUNTY WARNING AREA LATE TONIGHT.
USED A BLEND OF BIAS CORRECTED MET/MAV GUIDANCE FOR MAXIMUM
TEMPERATURES TODAY AND LOWS TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 AM EDT MONDAY...
A COLD FRONT WILL MOVE OVER THE OHIO RIVER VALLEY TUESDAY MORNING
AND IS EXPECTED TO JUMP TO THE LEE TROUGH PERCHED ACROSS THE
PIEDMONT IN THE AFTERNOON. A PREFRONTAL SHORT WAVE WILL TRACK ACROSS
KENTUCKY TUESDAY MORNING...BRINGING SHOWERS AND POSSIBLY A FEW
RUMBLES OF THUNDER...TO THE FAR WESTERN FORECAST AREA (BLUEFIELD VA-
LEWISBURG WV). LOW AND MID LEVEL FLOW TURNS WESTERLY
QUICKLY...REDUCING SHOWER ACTIVITY MOVING EAST TO THE BLUE RIDGE.
MORNING SHOWERS MAY NOT COMPLETELY FADE AS THEY APPROACH THE BLUE
RIDGE AS THIS WAVE TRACKS EAST OVER THE AREA. AS THE FRONT JUMPS TO
THE LEE TROUGH IN THE AFTERNOON...A NEW LINE OF CONVECTION WILL
FORM. ALL MODELS ARE HAVING A TOUGH TIME PINPOINTING WHERE THIS LINE
WILL INITIATE. BASED ON WHERE MODELS HAVE THE LEE TROUGH
POSITIONED...THIS LINE WILL BE EAST OF HWY 29...POSSIBLY EAST OF HWY
501. THE DEW POINT FRONT LAGS BEHIND AND THE MOUNTAINS MAY NOT SEE
SHOWERS CLEARING THE AREA UNTIL LATE IN THE EVENING...WITH CLEARING
IN THE PIEDMONT DURING THE EARLY MORNING HOURS WEDNESDAY. BY SUNRISE
WEDNESDAY MORNING...THE DEW POINT FRONT SHOULD BE SOUTH INTO NORTH
CAROLINA. A WEAK BUT COOL AREA OF HIGH PRESSURE WILL MOVE OVER THE
REGION WEDNESDAY...KEEPING THE REGION DRY FOR A COUPLE OF DAYS.
TUESDAY SHOULD BE THE LAST OF THE HOT DAY FOR THIS WEEK. DEPENDING
ON THE TIMING OF SHOWERS...HIGH TEMPERATURES ACROSS THE MOUNTAINS
WILL RANGE IN THE 80S...WITH LOWER TO MID 90S EAST. WEDNESDAY
TEMPERATURES WILL FALL BACK CLOSER TO NORMAL AS THE FRONT SINKS
SOUTH.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 350 PM EDT SUNDAY...
BROAD TROUGHING ACROSS THE NORTHEAST U.S. WILL DOMINATE THE
WEATHER AT THE BEGINNING OF THE PERIOD. THE FRONTAL
BOUNDARY/BAROCLINIC ZONE SHOULD BE LOCATED FROM THE MIDWEST INTO
THE SOUTHEAST STATES...HOPEFULLY SAFELY ENOUGH SOUTH OF OUR AREA
TO INHIBIT CONVECTION OF MUCH EXTENT. HOWEVER...WILL NEED TO WATCH
THURSDAY AS THERE IS YET ANOTHER UPSTREAM WAVE RIDING ALONG THE
BAROCLINIC ZONE THAT COULD BUCKLE THE BOUNDARY BACK FAR ENOUGH
NORTH TO ALLOW CONVECTION TO DRIFT BACK INTO THE SOUTHWEST PART OF
THE CWA...ESPECIALLY THE NW NC MOUNTAINS.
THERE IS BETTER PROBABILITY/CONFIDENCE THAT ONCE THIS FEATURE
PASSES BY TO THE SOUTH FRIDAY...WE WILL SEE GREATER POTENTIAL FOR
THE FRONTAL BOUNDARY TO DRIFT FURTHER SOUTH AND TAKE THE
CONVECTION WITH IT.
A WEAK UPPER LOW CUTS OFF ACROSS THE SOUTHEAST STATES BY THE
WEEKEND AND STALLS. BY SAT-SUN...THE UPPER RIDGE AMPLIFIES ACROSS
THE CENTRAL U.S. AND WE QUICKLY RETURN BACK TO A MORE UNSTABLE
NORTHWEST FLOW AND THE POTENTIAL FOR UPSTREAM CONVECTIVE COMPLEXES
TO REACH THE REGION.
850MB TEMPS DROP BELOW +20C THU-SAT...CREEPING BACK ABOVE +20C
ACROSS MUCH OF THE CWA BY THE END OF NEXT WEEKEND. DEWPOINTS DROP
INTO THE 50S ACROSS THE NORTHERN PART OF THE CWA BY THU
MORNING...WHICH SHOULD BE QUITE REFRESHING...BEFORE THEY CREEP
BACK UP INTO THE 60S TO LOW 70S BY THE WEEKEND. NEAR TO SLIGHTLY
BELOW NORMAL TEMPS THU-FRI...SHOULD RETURN TO ABOVE NORMAL LEVELS
BY THE WEEKEND.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
AS OF 130 AM EDT MONDAY...
WEAK SHORT WAVE COMING OUT OF OHIO WILL GENERATE SCATTERED SHOWERS
AND THUNDERSTORMS OVER SOUTHERN WEST VIRGINIA THIS MORNING. EXPECT
STORMS TO WEAKEN AS THEY MOVE EAST BUT HAVE KEPT VCSH IN THE KBLF
AND KLWB TAF BEFORE 12Z. FORMATION OF MVFR FOG EARLY THIS MORNING
WILL DEPEND ON AMOUNT OF CLOUD COVER. NO FOG FOG NOW EXPECTED AT
KROA BUT CONFIDENCE IS HIGH ENOUGH TO INCLUDE IN KBCB/KLYH AND
KDAN THROUGH 13Z/9AM.
WILL SEE MORE SHOWERS AND THUNDERSTORMS THIS AFTERNOON AS UPPER
ENERGY CROSSES THE AREA. EXPECT HIGHER POPS IN THE WEST. LOWER
CONFIDENCE THAT STORMS WILL IMPACT KLYH AND KDAN. THREAT OF
SHOWERS AND THUNDERSTORMS WILL DIMINISH AFTER SUNSET. REMOVED THE
CHANCE OF PRECIPITATION FROM THE FORECAST BY 03Z/11PM.
EXTENDED AVIATION DISCUSSION...
TUESDAY WILL SEE MORE WIDESPREAD THUNDERSTORMS SINCE A FRONT WILL
SINK SWD IN RESPONSE TO STRONGER UPPER TROUGH OVER THE GREAT
LAKES AND NORTHEAST UNITED STATES. THIS FRONT SINKS SOUTH OF THE
AREA FOR WEDNESDAY AND THURSDAY AND BUCKLES NWD AGAIN FRIDAY. SO
FOR NOW WILL EXPECT OVERALL VFR CONDITIONS OUTSIDE CONVECTION
TUESDAY...THEN FOG/STRATUS POSSIBLE WED/THU MORNING IN THE BCB/LWB
AREA PENDING HOW DRY THE AIR GETS BEHIND THIS FRONT. THEN MORE
SHOWERS AND STORMS POSSIBLE FRIDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...RCS
LONG TERM...RAB
AVIATION...AMS/WP
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
338 AM CDT MON JUL 20 2015
.SHORT TERM...
TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM.
THE MAIN FOCUS FOR TODAY IS ON THE CHANCES FOR CONVECTION AHEAD OF A
COLD FRONT WHICH WILL PUSH THROUGH THE REGION BY THIS EVENING.
A CLUSTER OF SHOWERS OUT IN NORTHWEST IOWA AND SOUTHWEST MINNESOTA
ASSOCIATED WITH A MID LEVEL SHORT WAVE TROUGH IS EXPECTED TO
DIMINISH IN COVERAGE/INTENSITY OVER THE NEXT FEW HOURS...BUT COULD
CLIP PORTIONS OF SOUTH CENTRAL WISCONSIN THIS MORNING...SO HAVE PUT
SOME HIGH CHANCES IN THERE FOR THE SHOWERS. INSTABILITY WILL BE ON
THE INCREASE TODAY AHEAD OF THE COLD FRONT WHICH IS CURRENTLY IN
CENTRAL MINNESOTA AND WILL EXTEND FROM NORTHEAST WISCONSIN TO WEST
CENTRAL WISCONSIN AROUND NOON TODAY. HAVE LIKED THE RAP THIS
MORNING AND ITS TRENDS WITH SURFACE DEW POINTS/INSTABILITY...WHICH
IS ON THE LOWER SIDE AT 1000 J/KG MLCAPE WHEN COMPARED TO THE 20.00Z
NAM/GFS WHICH ARE PUSHING CLOSER TO 2000-3000 J/KG THANKS TO
FORECAST SURFACE DEW POINTS OVER 70F. SHOULD THE RAP THERMAL
PROFILE PAN OUT...IT WOULD MEAN A SKINNY CAPE SCENARIO WITH
DECREASING SHEAR DUE TO THE LEAD SHORTWAVE TROUGH DEPARTING TO THE
SOUTHEAST. THEREFORE...OUTSIDE OF A FEW HIGHER GUSTS POSSIBLE DUE
TO THE DRY SOUNDING...AM NOT ANTICIPATING MUCH IN THE WAY OF SEVERE
WEATHER FOR TODAY. AFTER THE COLD FRONT MOVES THROUGH...SKIES WILL
CLEAR OUT WITH WINDS GOING LIGHT TONIGHT.
.LONG TERM...
TUESDAY THROUGH FRIDAY... FORECAST CONFIDENCE HIGH.
DRIER AIR WILL SETTLE INTO SOUTHERN WI ON TUESDAY. A HIGH AMPLITUDE
UPPER RIDGE OVER THE CENTER OF THE COUNTRY AND A SPRAWLING UPPER LOW
OVER ONTARIO AND QUEBEC CANADA WILL SET UP A BLOCKING PATTERN AND WE
WILL BE UNDER A DRY NORTHWEST FLOW PATTERN THROUGH MUCH OF THE WEEK.
SURFACE HIGH PRESSURE WILL TAKE HOLD OVER THE GREAT LAKES REGION AND
WE CAN EXPECT LIGHT WESTERLY WINDS. MAX TEMPERATURES WILL ONLY BE IN
THE UPPER 70S TUESDAY AND GRADUALLY MODIFY INTO THE LOWER 80S BY
FRIDAY... EXCEPT SLIGHTLY COOLER BY THE LAKESHORE.
THE GFS ALLOWS A SHORTWAVE TO MAKE IT ACROSS A HIGH-AMPLITUDE RIDGE
OVER THE UPPER MIDWEST AND BRING PRECIP TO WI ON THURSDAY. THE ECMWF
SHOWS A WEAKER SHORTWAVE THAT RUNS INTO THE DRY AIR AND KEEPS THE
AREA DRY. TRENDED TOWARD THE DRIER FORECAST FOR THU SINCE PRECIP
WILL HAVE A HARD TIME OVERCOMING THE DRY AIR IN PLACE.
SATURDAY... FORECAST CONFIDENCE MEDIUM.
THERE IS BETTER AGREEMENT FOR A STRONGER SHORTWAVE TROUGH TO REACH
THE GREAT LAKES ON FRI NIGHT OR SATURDAY AND BRING SHOWER AND
THUNDERSTORM CHANCES TO WI. THE GFS IS STRONGER AND BRINGS A BOWLING
BALL UPPER LOW THROUGH SOUTHERN CANADA WITH THE SURFACE TROUGH
CROSSING WI FRIDAY NIGHT. THE ECMWF HAS A WEAKER UPPER TROUGH AND
DELAYS THE SURFACE TROUGH UNTIL SATURDAY AFTERNOON. A FRIDAY NIGHT
FRONTAL PASSAGE WOULD KEEP SEVERE THUNDERSTORM CHANCES DOWN.
SUNDAY AND MONDAY... FORECAST CONFIDENCE MEDIUM.
A RIDGE OVER THE SOUTHWEST STATES WILL KEEP US IN A FAIRLY DRY
NORTHWEST FLOW PATTERN EARLY NEXT WEEK. WEAK SHORTWAVES RIDING OVER
THE RIDGE WILL LEAD TO INTERMITTENT PRECIP CHANCES. EXPECT MAX
TEMPERATURES TO REMAIN IN THE LOWER 80S DURING THIS TIME.
&&
.AVIATION/12Z TAFS/...
THE MAIN FOCUS AT THE TAF SITES IS ON THE POTENTIAL FOR SHOWERS AND
THUNDERSTORMS TODAY AHEAD OF A COLD FRONT. WINDS WILL BECOME GUSTY
AS WELL OUT OF THE SOUTHWEST AHEAD OF THE FRONT WITH SOME GUSTS
POSSIBLY REACHING THE 20-25KT RANGE. ANY SHOWERS OR THUNDERSTORMS
COULD PRODUCE SOME WINDY CONDITIONS AS WELL...BUT THINK THAT FLIGHT
CONDITIONS SHOULD MAINLY STAY VFR GIVEN HOW DRY CONDITIONS ARE.
SKIES WILL CLEAR OUT AND WINDS WILL GO LIGHT THIS EVENING AS THE
FRONT PUSHES OFF TO THE SOUTHEAST.
&&
.MARINE...
THE MAIN CONCERN FOR TODAY IS WITH THE GUSTY OFF SHORE WINDS WHICH
LOOK LIKE THEY WILL PUSH INTO THE 20 TO 30KT RANGE...PARTICULARLY
FURTHER TO THE NORTH. WAVES WILL BE THE HIGHEST OUT TOWARD THE OPEN
WATER DUE TO THE WEST-SOUTHWEST WINDS. MAY HAVE TO PUSH OUT A SMALL
CRAFT ADVISORY DUE TO THESE POTENTIALLY HIGHER GUSTS.
OTHERWISE...SOME SHOWERS AND THUNDERSTORMS ARE POSSIBLE TODAY AS
WELL WHEN A COLD FRONT DROPS THROUGH THE REGION. SOME GUSTY WINDS
MAY ACCOMPANY THESE SHOWERS AND STORMS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...HALBACH
TUESDAY THROUGH SUNDAY...MRC
AREA FORECAST DISCUSSION...UPDATED
NWS SAN JOAQUIN VALLEY - HANFORD CA
550 AM PDT MON JUL 20 2015
.UPDATE...
UPDATED FOR URBAN AND SMALL STREAM FLOOD ADVISORY.
&&
.SYNOPSIS...
TROPICAL MOISTURE WILL CONTINUE FLOWING INTO THE REGION FROM THE
SOUTH THROUGH THE REMAINDER OF TODAY. AS A RESULT...THERE WILL
REMAIN A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH THIS EVENING. A
DRYING TREND AND A RETURN TO SUMMER LIKE TEMPERATURES IS EXPECTED BY
MID WEEK AS THE TROPICAL MOISTURE GETS PUSHED OUT OF OUR AREA.
&&
.DISCUSSION...
RUNOFF FROM THE STRONG THUNDERSTORMS OVER THE TEHACHAPI MOUNTAINS
SUNDAY NIGHT HAS BEGUN SPILLING INTO THE FAR SOUTH END OF THE SAN
JOAQUIN VALLEY. THE CALIFORNIA HIGHWAY PATROL HAS REPORTED SOME
ROAD FLOODING AND MUD FLOWS ON ROADS IN THE SOUTH END. RUNOFF FROM
THE MOUNTAINS LIKELY WILL CONTINUE OVER THE NEXT FEW HOURS. HAVE
THEREFORE ISSUED AN URBAN AND SMALL STREAM FLOOD ADVISORY FOR THE
SOUTH END OF THE SAN JOAQUIN VALLEY THROUGH 1615Z /0915 PDT/ THIS
MORNING.
&&
.PREV DISCUSSION... /ISSUED 250 AM PDT MON JUL 20 2015/
DISCUSSION...
ALTHOUGH TROPICAL MOISTURE CONTINUED TO MOVE INTO CALIFORNIA SUNDAY
THE FOCUS WAS OVER THE SOUTHERN PART OF THE STATE...INCLUDING KERN
AND TULARE COUNTIES. THUNDERSTORMS CAUSED FLOODING AND MUD SLIDES IN
THE TEHACHAPI AND SAN EMIGDIO MOUNTAINS...AND ALTHOUGH THE RAINS HAD
TAPERED OFF AS OF 08Z /0100 PDT/...THE THREAT CONTINUED FROM SHOWERS
AND THUNDERSTORMS OVER INYO AND SAN BERNARDINO COUNTIES.
AN UPPER-LEVEL RIDGE PERSISTS OVER THE SOUTHERN UNITED STATES THIS
MORNING AS AN UPPER-LEVEL TROUGH DROPS INTO THE PACIFIC NORTHWEST.
THIS PATTERN RESULTS IN A SOUTHWESTERLY FLOW ALOFT OVER CENTRAL
CALIFORNIA WHICH CARRIES TROPICAL MOISTURE FROM FORMER HURRICANE
DOLORES INTO THE WFO HANFORD WARNING/FORECAST AREA.
DESPITE LESS CLOUDS THAN ORIGINALLY ANTICIPATED...HIGH TEMPERATURES
SUNDAY IN THE CENTRAL AND SOUTHERN SAN JOAQUIN VALLEY WERE WELL
BELOW NORMAL...IN THE UPPER 80S TO LOWER 90S. TEMPERATURES EARLY
THIS MORNING WERE RUNNING SIMILAR TO EARLY SUNDAY MORNING...SO
SHOULD SEE ANOTHER DAY WITH BELOW-NORMAL HIGHS.
ALTHOUGH CONVECTION HAS TEMPORARILY CEASED OVER THE CENTRAL
CALIFORNIA INTERIOR...THE MODELS KEEP ABUNDANT MID-LEVEL MOISTURE
OVER AT LEAST THE SOUTHERN HALF OF THE WFO HANFORD WARNING/FORECAST
AREA. OF INTEREST IS THAT BOTH THE NAM-12 AND THE HRRR HAVE LIMITED
MOISTURE OVER MERCED AND MARIPOSA COUNTIES TODAY...WITH THE NAM-12
FINALLY BRINGING THE MOISTURE NORTHWARD THIS EVENING AS KERN COUNTY
BEGINS TO DRY OUT. IF THIS VERIFIES...CONVECTION COULD CONTINUE OVER
MUCH OF THE REGION NORTH OF KERN COUNTY OVERNIGHT RATHER THAN BEING
CONFINED MAINLY TO THE SOUTHERN SIERRA NEVADA AFTER MIDNIGHT.
SUNDAY MORNING/S RFC QPF GUIDANCE FOR INTERIOR CENTRAL CALIFORNIA
CONTINUED A TREND OF BEING WETTER WITH EACH SUCCESSIVE RUN. THE RFC
STORM-TOTAL QPF FOR THE SOUTHERN SIERRA NEVADA FORECAST POINTS WAS
OVER AN INCH THROUGH TUESDAY MORNING. FURTHER SOUTH...ALTHOUGH THERE
ARE NO FORECAST POINTS...THE GROUND IS SATURATED FROM SUNDAY/S RAIN
SO THERE LIKELY WILL BE FLOODING FROM EXCESSIVE RUNOFF. WILL KEEP
THE FLASH FLOOD WATCH FOR THE MOUNTAIN AND DESERT AREAS IN PLACE
THROUGH THIS EVENING.
AS THE TROUGH DROPS THROUGH THE PACIFIC NORTHWEST AND INTO CENTRAL
CALIFORNIA THE SOUTHWEST FLOW ALOFT WILL STRENGTHEN AND BEGIN DRYING
OUT THE REGION BEGINNING WEDNESDAY. IN TURN...THE RIDGE IS FORECAST
TO BUILD BACK INTO CALIFORNIA WITH THE 500-MB 5880-METER HEIGHT LINE
PUSHING NORTH OF THE WFO HANFORD WARNING/FORECAST AREA BY FRIDAY.
&&
.AVIATION...
SCATTERED THUNDERSTORM ACTIVITY WILL PERSIST ACROSS THE MOUNTAIN AND
DESERT AREAS OF CENTRAL CALIFORNIA...WITH ISOLATED THUNDERSTORMS
ALSO POSSIBLE IN THE SAN JOAQUIN VALLEY OVER THE NEXT 24 HOURS.
THESE STORMS WILL BRING AREAS OF MVFR AND LOCAL IFR/VLIFR CONDITIONS
ALONG WITH WITH SOME POSSIBLE MOUNTAIN OBSCURATIONS IN THE HIGHER
TERRAIN. GUSTY AND ERRATIC WINDS AROUND 40 KTS CAN ALSO ACCOMPANY
THE STORMS. OTHERWISE...VFR CONDITIONS WILL PREVAIL OVER THE CENTRAL
CALIFORNIA INTERIOR.
&&
.AIR QUALITY ISSUES...
NONE.
&&
.CERTAINTY...
THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS HIGH.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM.
THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED
BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD.
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL
INFORMATION AND/OR TO PROVIDE FEEDBACK.
&&
.CLIMATE...
RECORDS
SITE DATE HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR
KFAT 07-20 111:1908 81:1973 78:1938 54:1903
KFAT 07-21 112:1908 79:1987 82:2006 56:1973
KFAT 07-22 112:2006 83:1896 84:2006 56:1903
KBFL 07-20 112:1938 84:1973 82:1979 49:1906
KBFL 07-21 112:1938 81:1987 83:1969 50:1906
KBFL 07-22 113:1908 82:1984 88:1910 50:1903
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
URBAN AND SMALL STREAM FLOOD ADVISORY THROUGH 0915 PDT THIS
MORNING FOR THE SOUTH END OF THE SAN JOAQUIN VALLEY /CAC029/.
FLASH FLOOD WATCH THROUGH THIS EVENING FOR THE SOUTHERN SIERRA
NEVADA FROM YOSEMITE NATIONAL PARK TO THE KERN COUNTY LINE
/CAZ096-097/.
FLASH FLOOD WATCH THROUGH THIS EVENING FOR THE KERN COUNTY
MOUNTAINS AND DESERT AND THE INDIAN WELLS VALLEY /CAZ095-098-099/.
&&
$$
PUBLIC...SANGER
AVN/FW...DURFEE
PREV DISCUSSION...SANGER
SYNOPSIS...ANDERSEN
WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
909 AM EDT MON JUL 20 2015
.UPDATE...
SO FAR EVERYTHING LOOKING TO BE ON TRACK THIS MORNING WITH
ISOLATED CONVECTION OVER APALACHE BAY AND THE NATURE COAST. LARGE
AREA OF LOW TO MID LEVEL CLOUDINESS OVER THE SOUTHEASTERN AREA OF
RESPONSIBILITY MAY INHIBIT CONVECTION THIS MORNING AND THINK THE
HRRR MODEL MAY BE OVER DOING THINGS JUST A BIT OVER THE SOUTH.
EXPECT IT WILL POP THIS AFTERNOON BUT MAYBE A BIT AFTER THE
EARLIER RUNS OF THE MODEL INDICATED. LATEST HRRR RUN NOW SEEMS TO
HAVE PICKED UP ON THAT TREND AND IS A BIT LATER IN DEVELOPMENT
SOUTH OF FLORIDA STATE ROAD 16.
&&
.AVIATION...
OVERALL WILL KEEP THE MENTION OT THUNDERSTORMS IN THE VICINITY
FOR RIGHT NOW BUT MAY HAVE TO AMEND LATER. THAT WILL BE ESPECIALLY
TRUE FOR SGJ AND GNV.
&&
.MARINE... NO CHANGE TO CURRENT FORECAST OR THINKING. WILL HAVE TO
WATCH FOR A NOCTURNAL SURGE OVER THE OFFSHORE WATERS FOR TONIGHT.
WITH A SYNOPTIC SOUTHWEST FLOW LATE AFTERNOON AND EVENING STORMS
WILL BE A CONCERN FOR OFFSHORE BOATERS.
RIP CURRENTS: LOW RISK.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 95 75 94 75 / 50 30 50 20
SSI 93 78 92 79 / 60 30 40 10
JAX 93 75 93 77 / 60 40 50 10
SGJ 92 76 92 76 / 60 40 50 10
GNV 92 74 92 76 / 70 30 60 10
OCF 90 74 90 74 / 40 30 60 20
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
SANDRIK/SHASHY
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
806 AM EDT MON JUL 20 2015
.SYNOPSIS...
A PRESSURE RIDGE WILL EXTEND FROM THE ATLANTIC WESTWARD THROUGH
THE GULF OF MEXICO THROUGH WEDNESDAY. NORTH OF THE RIDGE A
PRESSURE TROUGH WILL REMAIN IN THE FORECAST AREA. THE PATTERN WILL
BRING ABOVE NORMAL TEMPERATURES WITH SCATTERED MAINLY DIURNAL
THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE SURFACE PRESSURE TROUGH WILL REMAIN IN THE FORECAST AREA
THROUGH TONIGHT. ALOFT...THE AREA WILL BE ON THE EASTERN PERIPHERY
OF THE SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY RIDGE. THE
MODELS AND WATER VAPOR IMAGERY TRENDS INDICATE ANOTHER IN A SERIES
OF MID-LEVEL SHORTWAVE TROUGHS WILL AFFECT THE AREA. THUNDERSTORM
COVERAGE MAY BE LIMITED BY THE UPPER RIDGING AND SLOW STORM
MOVEMENT AS INDICATED BY DIFLUENT HEIGHTS. THE HRRR AND ARW
DISPLAY ISOLATED TO SCATTERED COVERAGE TODAY. THE SPC WRF
INDICATED CONSIDERABLE COVERAGE THIS EVENING. WE LEANED TOWARD THE
HIGHER GUIDANCE POPS BASED ON THE PATTERN WITH THE GREATEST CHANCE
LATE THIS AFTERNOON INTO THE EVENING. THE NAM HAS SURFACE-BASED
LI/S -6 TO -8 TODAY. MODERATE INSTABILITY WITH AN INVERTED-V
SOUNDING INDICATES DAMAGING WIND MAY OCCUR WITH A FEW OF THE
THUNDERSTORMS. A SLOW STORM MOVEMENT AND PRECIPITABLE WATER NEAR 2
INCHES ALSO INDICATES A POSSIBILITY OF LOCALIZED FLOODING. THE
RECENT BIAS SUPPORTS THE HIGHER TEMPERATURE GUIDANCE. IT WILL BE
ANOTHER HOT DAY WITH HIGHS AROUND 100.
THUNDERSTORM COVERAGE SHOULD DIMINISH OVERNIGHT WITH THE LOSS OF
HEATING AND PREVIOUS CONVECTION ALTHOUGH ANOTHER IN A SERIES OF
MID-LEVEL SHORTWAVE TROUGHS SUPPORTS A CONTINUED CHANCE LATE. USED
THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
THE SURFACE TROUGH WILL CONTINUE IN THE FORECAST AREA AHEAD OF AN
APPROACHING COLD FRONT THROUGH TUESDAY NIGHT. THERE WILL ALSO
BE A SERIES OF MID-LEVEL SHORTWAVE TROUGHS IN THE WESTERLY FLOW.
THE PATTERN SUPPORTS A CONTINUED CHANCE OF THUNDERSTORMS.
FORECASTED THE HIGHER POPS NEAR THE TIME OF MAXIMUM HEATING. USED
THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST. IT WILL
REMAIN HOT AHEAD OF THE FRONT TUESDAY WITH HIGHS AROUND 100.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE GFS AND ECMWF DISPLAY A FRONT STALLED IN THE FORECAST AREA
EARLY IN THE MEDIUM-RANGE PERIOD. THE FRONT MAY BE JUST SOUTH OF
THE AREA LATER IN THE PERIOD. ALOFT...THE MODELS INDICATE UPPER
TROUGHING ALONG THE EAST COAST. THE PATTERN SUPPORTS CHANCE POPS
WITH TEMPERATURES LOWERING TO NEAR CLIMATOLOGY. THE GFS...
ECMWF...AND EKD MOS HAVE HIGHS NEAR 100 WEDNESDAY AND IN THE LOWER
AND MIDDLE 90S DURING THE REST OF THE PERIOD. THE MOS HAS POPS 20
TO 40 PERCENT THROUGH THE PERIOD.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS EXPECTED OUTSIDE OF DIURNAL THUNDERSTORMS AND EARLY
MORNING FOG.
LIGHT WEST WINDS DURING THE MORNING BECOMING SOUTHWEST 8-10 KNOTS
THIS AFTERNOON. SCATTERED DIURNAL CONVECTION TO DEVELOP AFTER 18Z
AND CONTINUING INTO THE EARLY EVENING. MODELS INDICATE POTENTIAL
FOR FOG EARLY TUESDAY MORNING...ALTHOUGH A 25 TO 30 KNOT NOCTURNAL
JET SHOULD LIMIT DEVELOPMENT. FOG POTENTIAL MAY ALSO DEPEND ON
WHICH SITES RECEIVE RAIN TODAY.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS EXPECTED IN DIURNAL
CONVECTION TUESDAY THROUGH FRIDAY. AREAS OF MVFR VSBYS POSSIBLE
DURING THE EARLY MORNING EACH DAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
615 AM EDT MON JUL 20 2015
.SYNOPSIS...
A PRESSURE RIDGE WILL EXTEND FROM THE ATLANTIC WESTWARD THROUGH
THE GULF OF MEXICO THROUGH WEDNESDAY. NORTH OF THE RIDGE A
PRESSURE TROUGH WILL REMAIN IN THE FORECAST AREA. THE PATTERN WILL
BRING ABOVE NORMAL TEMPERATURES WITH SCATTERED MAINLY DIURNAL
THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
PATCHY FOG HAS DEVELOPED...MAINLY IN AREAS THAT RECEIVED RAIN
YESTERDAY. HEATING AND MIXING WILL DISSIPATE ANY FOG EARLY THIS
MORNING.
THE SURFACE PRESSURE TROUGH WILL REMAIN IN THE FORECAST AREA
THROUGH TONIGHT. ALOFT...THE AREA WILL BE ON THE EASTERN PERIPHERY
OF THE SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY RIDGE. THE
MODELS AND WATER VAPOR IMAGERY TRENDS INDICATE ANOTHER IN A SERIES
OF MID-LEVEL SHORTWAVE TROUGHS WILL AFFECT THE AREA. THUNDERSTORM
COVERAGE MAY BE LIMITED BY THE UPPER RIDGING AND SLOW STORM
MOVEMENT AS INDICATED BY DIFLUENT HEIGHTS. THE HRRR AND ARW DISPLAY
ISOLATED TO SCATTERED COVERAGE TODAY. THE SPC WRF INDICATED
CONSIDERABLE COVERAGE THIS EVENING. WE LEANED TOWARD THE HIGHER
GUIDANCE POPS BASED ON THE PATTERN WITH THE GREATEST CHANCE LATE
THIS AFTERNOON INTO THE EVENING. THE NAM HAS SURFACE-BASED LI/S
-6 TO -8 TODAY. MODERATE INSTABILITY WITH AN INVERTED-V SOUNDING
INDICATES DAMAGING WIND MAY OCCUR WITH A FEW OF THE THUNDERSTORMS.
A SLOW STORM MOVEMENT AND PRECIPITABLE WATER NEAR 2 INCHES ALSO
INDICATES A POSSIBILITY OF LOCALIZED FLOODING. THE RECENT BIAS
SUPPORTS THE HIGHER TEMPERATURE GUIDANCE. IT WILL BE ANOTHER HOT
DAY WITH HIGHS AROUND 100.
THUNDERSTORM COVERAGE SHOULD DIMINISH OVERNIGHT WITH THE LOSS OF
HEATING AND PREVIOUS CONVECTION ALTHOUGH ANOTHER IN A SERIES OF
MID-LEVEL SHORTWAVE TROUGHS SUPPORTS A CONTINUED CHANCE LATE. USED
THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
THE SURFACE TROUGH WILL CONTINUE IN THE FORECAST AREA AHEAD OF AN
APPROACHING COLD FRONT THROUGH TUESDAY NIGHT. THERE WILL ALSO
BE A SERIES OF MID-LEVEL SHORTWAVE TROUGHS IN THE WESTERLY FLOW.
THE PATTERN SUPPORTS A CONTINUED CHANCE OF THUNDERSTORMS.
FORECASTED THE HIGHER POPS NEAR THE TIME OF MAXIMUM HEATING. USED
THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST. IT WILL
REMAIN HOT AHEAD OF THE FRONT TUESDAY WITH HIGHS AROUND 100.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE GFS AND ECMWF DISPLAY A FRONT STALLED IN THE FORECAST AREA
EARLY IN THE MEDIUM-RANGE PERIOD. THE FRONT MAY BE JUST SOUTH OF
THE AREA LATER IN THE PERIOD. ALOFT...THE MODELS INDICATE UPPER
TROUGHING ALONG THE EAST COAST. THE PATTERN SUPPORTS CHANCE POPS
WITH TEMPERATURES LOWERING TO NEAR CLIMATOLOGY. THE GFS...
ECMWF...AND EKD MOS HAVE HIGHS NEAR 100 WEDNESDAY AND IN THE LOWER
AND MIDDLE 90S DURING THE REST OF THE PERIOD. THE MOS HAS POPS 20
TO 40 PERCENT THROUGH THE PERIOD.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
AREAS OF MVFR VSBYS POSSIBLE 12Z-13Z. SHOULD SEE VFR CONDITIONS
RETURN TO ALL TAF SITES BY 14Z AS MIXING COMMENCES. LIGHT WEST WINDS
DURING THE MORNING BECOMING SOUTHWEST 8-10 KNOTS IN THE AFTERNOON.
SCATTERED DIURNAL CONVECTION TO DEVELOP AFTER 18Z AND CONTINUING
INTO THE EARLY EVENING.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS EXPECTED IN DIURNAL
CONVECTION TUESDAY THROUGH FRIDAY. AREAS OF MVFR VSBYS POSSIBLE
DURING THE EARLY MORNING EACH DAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1041 AM CDT MON JUL 20 2015
.UPDATE...
ISSUED AT 1040 AM CDT MON JUL 20 2015
UPDATED THE FORECAST TO REMOVE PATCHY FOG THIS MORNING AND ALSO
LOWERED CHANCES OF SHOWERS AND THUNDERSTORMS THIS MORNING. ANOTHER
VERY WARM AND HUMID DAY EXPECTED WITH HIGHS IN THE MID TO UPPER
80S AND DEWPOINTS IN THE LOW TO MID 70S. HEAT INDICES THIS
AFTERNOON TO PEAK IN THE UPPER 80S/LOWER 90S OVER CENTRAL IL AND
MID TO UPPER 90S IN SOUTHEAST IL. MCS MOVING EAST OUT OF MO INTO
SW AND WEST CENTRAL IL WITH LEADING EDGE OF SHOWERS/THUNDERSTORMS
AS FAR EAST AS A BEARDSTOWN TO JACKSONVILLE TO EAST OF ST LOUIS
LINE AND TRACKING EAST AT 35 MPH. RAP MODEL APPEARED TO HAVE BEST
HANDLE ON THIS MCS AND IT SPREADS QPF EAST ACROSS AREAS FROM
RUSHVILLE TO RANTOUL SOUTH DURING THE AFTERNOON. A COLD FRONT OVER
CENTRAL PARTS OF WI/IA TO TRACK SE INTO NW IL LATER THIS AFTERNOON
AND TO HAVE SHOWERS AND THUNDERSTORMS ALONG THIS BOUNDARY AS WELL
MOVING INTO IL RIVER VALLEY LATE TODAY. SO WILL CONTINUE CHANCES
OF SHOWERS AND THUNDESTORMS ACROSS CENTRAL/SE IL THIS AFTERNOON
WITH HIGHEST CHANCES OF RAIN FROM I-72 SOUTH. SPC HAS SHIFTED
SLIGHT RISK OF SEVERE STORMS THIS AFTERNOON/EVENING SOUTH OF
CLAY...RICHLAND AND LAWERENCE COUNTIES. BUT MARGINAL RISK OF
SEVERE STORMS COVERS CENTRAL IL CWA WITH 5-15% RISK OF HAIL AND
DAMAGING WIND GUSTS. LOCALLY HEAVY RAINS AND FREQUENT LIGHTNING
ALSO POSSIBLE WITH STRONGER STORMS FROM MID AFTERNOON INTO EARLY
EVENING UNTIL SUNSET.
&&
.SHORT TERM...(TODAY)
ISSUED AT 318 AM CDT MON JUL 20 2015
CONVECTION THAT DEVELOPED NEAR ST.LOUIS LAST EVENING HAS SHIFTED
SOUTHEAST INTO EXTREME SOUTHERN ILLINOIS EARLY THIS MORNING. THE
STORMS ARC BACK TO THE NORTHWEST INTO PARTS OF WESTERN MO INTO
NORTHEAST KS ALONG A FRONTAL BOUNDARY WHICH LOOKS TO BE THE MAIN
FOCUS FOR ADDITIONAL DEVELOPMENT LATER TODAY. QUESTION BECOMES WHAT
AFFECT FURTHER NORTH INTO OUR AREA IT MAY HAVE ON COVERAGE OF
SHOWERS AND STORMS THIS AFTERNOON AND THIS EVENING AS ANOTHER COOL
FRONT TRACKS ACROSS THE AREA FROM THE NORTHWEST LATE TODAY.
USING THE TIMING AND COVERAGE OFF THE RAP MODEL WOULD SUGGEST A
SLOWER ONSET OF PRECIP THAN EARLIER EXPECTED WITH THE BULK OF THE
ACTIVITY TIED TO THE SURFACE BOUNDARY STRETCHING ACROSS MISSOURI
THRU FAR SOUTHERN ILLINOIS...WITH A SECONDARY BAND OF SHOWERS AND
STORMS SHOWING UP ALONG THE WEAK COOL FRONT WHICH IS FORECAST TO BE
JUST TO OUR NORTHWEST LATE THIS AFTERNOON. THE HIGHER POPS WILL BE
FOR MAINLY THIS AFTERNOON WITH ONLY LOW CHANCE POPS FOR PRECIP THIS
MORNING ACROSS OUR WEST. MIXED LAYER CAPES OFF THE NAM MODEL FOR
THIS AFTERNOON ARE EXPECTED TO RANGE FROM 1500-2000 J/KG WITH 0-6KM
SHEAR VALUES OF 30 KTS. 700-500 MB LAPSE RATES NOT LOOKING THAT
IMPRESSIVE THOUGH...BUT STILL CAN`T RULE OUT A STRONG TO LOCALLY
SEVERE STORM THAT MAY BE CAPABLE OF PRODUCING GUSTY WINDS ALONG WITH
HEAVY RAINFALL DURING THE MID TO LATE AFTERNOON HOURS. SPC HAS
SHIFTED THE SLIGHT RISK FURTHER SOUTH AND WEST...CLOSER TO THE
AFOREMENTIONED BOUNDARY OVER MISSOURI. WITH THE MAIN CONVECTIVE
FRONT EXPECTED TO REMAIN TO OUR SOUTH...IT APPEARS THAT IS WHERE THE
MORE CONCENTRATED AREA OF HEAVY RAINFALL WILL OCCUR...AS A
RESULT...WILL NOT BE INCLUDING ANY FLASH FLOOD WATCH AT THIS TIME
FOR OUR FAR WESTERN COUNTIES WHICH RECEIVED HEAVY RAINFALL LAST
NIGHT.
.LONG TERM...(TONIGHT THROUGH SUNDAY)
ISSUED AT 318 AM CDT MON JUL 20 2015
SEVERAL WEAK BOUNDARIES IN THE REGION AND WILL CONTINUE TO PROVIDE
FOCUS FOR AN IMPULSE BRINGING PRECIP TODAY AND INTO TONIGHT.
HOWEVER, MODELS ARE SHIFTING SOUTH SOMEWHAT AND FOR THE MOST PART,
PUSH A COLD FRONT THROUGH THE STATE CONSIDERABLY FASTER TONIGHT.
GFS AND ECMWF ARE LARGELY DRY AFTER 06Z, WITH THE NAM STILL
STRUGGLING. HAVE PUSHED THE GRIDS CLOSER TO THAT SOLUTION, BUT THE
SLOWING NATURE OF THE BOUNDARY TOWARDS TOMORROW MORNING...HAVE KEPT
THE SLIGHTS ALONG AND SOUTH OF I-70, ALTHOUGH THOSE SMALL POPS MAY
ALSO GET PULLED WITH SUBSEQUENT FORECASTS IF THE TRENDS CONTINUE.
ELUSIVE DRY TREND IS BACK IN THE FORECAST FROM TOMORROW AFTERNOON
THROUGH WED EVENING, AND MUCH OF THURSDAY. THURSDAY A WAVE DIVES
INTO THE REGION AND ALTHOUGH MUCH OF THE PRECIP LOOKS TO PASS TO THE
SW, SOME SMALL POPS ARE WORKING THEIR WAY INTO THE SUPERBLEND ALONG
AND SW OF A LINE FROM HAVANA TO LAWRENCEVILLE. CONCERNED WITH THE
LOOK OF THE MODELS IN THAT TIME FRAME ARE NOT PROPERLY REPRESENTED
IN THE SUPERBLEND JUST YET. GFS IS MORE AGGRESSIVE WITH THE QPF ON
THURSDAY NIGHT OVER IL...AND ECMWF PASSES THE WAVE ALOFT IN THE SAME
TIME FRAME WITH LITTLE TO SHOW AT THE SFC. EXPECT SOME CHANGES IN
THIS PORTION OF THE FORECAST. WARMING TREND CONTINUES THROUGH THE
END OF THE WEEK, WITH THE HIGHEST TEMPS IN THE FORECAST NEXT WEEKEND
AGAIN. WITH THE WARM TEMPS, A RIDGE BUILDS IN THE DESERT SW AND
SOUTHERN PLAINS. ILLINOIS HAS VERY LITTLE IN THE WAY OF STEERING
FLOW AND MODELS ARE A BIT MORE SCATTERED WITH WEAK WAVES...WITH THE
GFS AND ECMWF DIVERGING AT THE WEEKEND DEALING WITH A TROF PASSING
ACROSS THE NRN TIER OF THE CONUS. FOR NOW, SLIGHT/CHANCE POPS
THROUGH THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 605 AM CDT MON JUL 20 2015
IFR TO VLIFR CONDITIONS IN FOG EXPECTED TO QUICKLY IMPROVE OVER
THE NEXT COUPLE OF HOURS. ONCE THE FOG LIFTS...WE EXPECT VFR
CONDITIONS THRU THIS FORECAST PERIOD. A COLD FRONT TO OUR
NORTHWEST EARLY THIS MORNING WILL PUSH ACROSS THE AREA LATE THIS
AFTERNOON OR EARLY THIS EVENING. MEANWHILE...A BAND OF SHOWERS
AND STORMS WAS MOVING ACROSS IOWA AND MISSOURI AND MAY PUSH
INTO THE AREA BY LATE MORNING OR EARLY AFTERNOON...HOWEVER
MODELS NOT VERY AGREEABLE AS TO WHETHER THE BAND WILL HOLD
TOGETHER BEFORE MOVING INTO OUR AREA. FOR NOW WILL CONTINUE WITH
THE VCTS OVER OUR WESTERN AREAS BY 16Z...AND MOVING INTO THE
EASTERN TAF LOCATIONS BY 18 OR 19Z. THE RAIN THREAT SHOULD END
FROM NORTHWEST TO SOUTHEAST THIS EVENING AS THE FRONT SHIFTS
AWAY FROM OUR AREA. SURFACE WINDS WILL BE SOUTHWEST AT 8 TO
13 KTS TODAY AND THEN SHIFT INTO A LIGHT NORTHWEST DIRECTION
AFTER FROPA LATER THIS EVENING AND DURING THE OVERNIGHT HOURS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...07
SHORT TERM...SMITH
LONG TERM...HJS
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
615 AM CDT MON JUL 20 2015
.SHORT TERM...(TODAY)
ISSUED AT 318 AM CDT MON JUL 20 2015
CONVECTION THAT DEVELOPED NEAR ST.LOUIS LAST EVENING HAS SHIFTED
SOUTHEAST INTO EXTREME SOUTHERN ILLINOIS EARLY THIS MORNING. THE
STORMS ARC BACK TO THE NORTHWEST INTO PARTS OF WESTERN MO INTO
NORTHEAST KS ALONG A FRONTAL BOUNDARY WHICH LOOKS TO BE THE MAIN
FOCUS FOR ADDITIONAL DEVELOPMENT LATER TODAY. QUESTION BECOMES WHAT
AFFECT FURTHER NORTH INTO OUR AREA IT MAY HAVE ON COVERAGE OF
SHOWERS AND STORMS THIS AFTERNOON AND THIS EVENING AS ANOTHER COOL
FRONT TRACKS ACROSS THE AREA FROM THE NORTHWEST LATE TODAY.
USING THE TIMING AND COVERAGE OFF THE RAP MODEL WOULD SUGGEST A
SLOWER ONSET OF PRECIP THAN EARLIER EXPECTED WITH THE BULK OF THE
ACTIVITY TIED TO THE SURFACE BOUNDARY STRETCHING ACROSS MISSOURI
THRU FAR SOUTHERN ILLINOIS...WITH A SECONDARY BAND OF SHOWERS AND
STORMS SHOWING UP ALONG THE WEAK COOL FRONT WHICH IS FORECAST TO BE
JUST TO OUR NORTHWEST LATE THIS AFTERNOON. THE HIGHER POPS WILL BE
FOR MAINLY THIS AFTERNOON WITH ONLY LOW CHANCE POPS FOR PRECIP THIS
MORNING ACROSS OUR WEST. MIXED LAYER CAPES OFF THE NAM MODEL FOR
THIS AFTERNOON ARE EXPECTED TO RANGE FROM 1500-2000 J/KG WITH 0-6KM
SHEAR VALUES OF 30 KTS. 700-500 MB LAPSE RATES NOT LOOKING THAT
IMPRESSIVE THOUGH...BUT STILL CAN`T RULE OUT A STRONG TO LOCALLY
SEVERE STORM THAT MAY BE CAPABLE OF PRODUCING GUSTY WINDS ALONG WITH
HEAVY RAINFALL DURING THE MID TO LATE AFTERNOON HOURS. SPC HAS
SHIFTED THE SLIGHT RISK FURTHER SOUTH AND WEST...CLOSER TO THE
AFOREMENTIONED BOUNDARY OVER MISSOURI. WITH THE MAIN CONVECTIVE
FRONT EXPECTED TO REMAIN TO OUR SOUTH...IT APPEARS THAT IS WHERE THE
MORE CONCENTRATED AREA OF HEAVY RAINFALL WILL OCCUR...AS A
RESULT...WILL NOT BE INCLUDING ANY FLASH FLOOD WATCH AT THIS TIME
FOR OUR FAR WESTERN COUNTIES WHICH RECEIVED HEAVY RAINFALL LAST
NIGHT.
.LONG TERM...(TONIGHT THROUGH SUNDAY)
ISSUED AT 318 AM CDT MON JUL 20 2015
SEVERAL WEAK BOUNDARIES IN THE REGION AND WILL CONTINUE TO PROVIDE
FOCUS FOR AN IMPULSE BRINGING PRECIP TODAY AND INTO TONIGHT.
HOWEVER, MODELS ARE SHIFTING SOUTH SOMEWHAT AND FOR THE MOST PART,
PUSH A COLD FRONT THROUGH THE STATE CONSIDERABLY FASTER TONIGHT.
GFS AND ECMWF ARE LARGELY DRY AFTER 06Z, WITH THE NAM STILL
STRUGGLING. HAVE PUSHED THE GRIDS CLOSER TO THAT SOLUTION, BUT THE
SLOWING NATURE OF THE BOUNDARY TOWARDS TOMORROW MORNING...HAVE KEPT
THE SLIGHTS ALONG AND SOUTH OF I-70, ALTHOUGH THOSE SMALL POPS MAY
ALSO GET PULLED WITH SUBSEQUENT FORECASTS IF THE TRENDS CONTINUE.
ELUSIVE DRY TREND IS BACK IN THE FORECAST FROM TOMORROW AFTERNOON
THROUGH WED EVENING, AND MUCH OF THURSDAY. THURSDAY A WAVE DIVES
INTO THE REGION AND ALTHOUGH MUCH OF THE PRECIP LOOKS TO PASS TO THE
SW, SOME SMALL POPS ARE WORKING THEIR WAY INTO THE SUPERBLEND ALONG
AND SW OF A LINE FROM HAVANA TO LAWRENCEVILLE. CONCERNED WITH THE
LOOK OF THE MODELS IN THAT TIME FRAME ARE NOT PROPERLY REPRESENTED
IN THE SUPERBLEND JUST YET. GFS IS MORE AGGRESSIVE WITH THE QPF ON
THURSDAY NIGHT OVER IL...AND ECMWF PASSES THE WAVE ALOFT IN THE SAME
TIME FRAME WITH LITTLE TO SHOW AT THE SFC. EXPECT SOME CHANGES IN
THIS PORTION OF THE FORECAST. WARMING TREND CONTINUES THROUGH THE
END OF THE WEEK, WITH THE HIGHEST TEMPS IN THE FORECAST NEXT WEEKEND
AGAIN. WITH THE WARM TEMPS, A RIDGE BUILDS IN THE DESERT SW AND
SOUTHERN PLAINS. ILLINOIS HAS VERY LITTLE IN THE WAY OF STEERING
FLOW AND MODELS ARE A BIT MORE SCATTERED WITH WEAK WAVES...WITH THE
GFS AND ECMWF DIVERGING AT THE WEEKEND DEALING WITH A TROF PASSING
ACROSS THE NRN TIER OF THE CONUS. FOR NOW, SLIGHT/CHANCE POPS
THROUGH THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 605 AM CDT MON JUL 20 2015
IFR TO VLIFR CONDITIONS IN FOG EXPECTED TO QUICKLY IMPROVE OVER
THE NEXT COUPLE OF HOURS. ONCE THE FOG LIFTS...WE EXPECT VFR
CONDITIONS THRU THIS FORECAST PERIOD. A COLD FRONT TO OUR
NORTHWEST EARLY THIS MORNING WILL PUSH ACROSS THE AREA LATE THIS
AFTERNOON OR EARLY THIS EVENING. MEANWHILE...A BAND OF SHOWERS
AND STORMS WAS MOVING ACROSS IOWA AND MISSOURI AND MAY PUSH
INTO THE AREA BY LATE MORNING OR EARLY AFTERNOON...HOWEVER
MODELS NOT VERY AGREEABLE AS TO WHETHER THE BAND WILL HOLD
TOGETHER BEFORE MOVING INTO OUR AREA. FOR NOW WILL CONTINUE WITH
THE VCTS OVER OUR WESTERN AREAS BY 16Z...AND MOVING INTO THE
EASTERN TAF LOCATIONS BY 18 OR 19Z. THE RAIN THREAT SHOULD END
FROM NORTHWEST TO SOUTHEAST THIS EVENING AS THE FRONT SHIFTS
AWAY FROM OUR AREA. SURFACE WINDS WILL BE SOUTHWEST AT 8 TO
13 KTS TODAY AND THEN SHIFT INTO A LIGHT NORTHWEST DIRECTION
AFTER FROPA LATER THIS EVENING AND DURING THE OVERNIGHT HOURS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SMITH
LONG TERM...HJS
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
631 AM EDT MON JUL 20 2015
.SYNOPSIS...
ISSUED AT 350 AM EDT MON JUL 20 2015
HIGH PRESSURE WILL QUICKLY MOVE ACROSS THE REGION TODAY. A WEAK
COLD FRONT WILL APPROACH LATE THIS AFTERNOON AND MOVE ACROSS THE
AREA TONIGHT. THERE WILL BE A SMALL CHANCE FOR SHOWERS AND
THUNDERSTORMS NEAR THIS FRONT. OTHERWISE TODAY WILL BEGIN MOSTLY
SUNNY WITH INCREASING CLOUDS THIS AFTERNOON. HIGH TEMPERATURES
WILL BE IN THE LOWER TO MIDDLE 80S. LOWS TONIGHT WILL BE IN THE
LOWER AND MIDDLE 60S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM EDT MON JUL 20 2015
WEAK HIGH PRESSURE WILL MOVE EAST TODAY WHILE SHORT WAVE AND
ASSOCIATED COLD FRONT APPROACH LATE THIS AFTERNOON AND MOVE
THROUGH CWA TONIGHT. FORCING AND MOISTURE FLUX WEAK WITH THIS
SYSTEM BUT ENOUGH AMBIENT MOISTURE AND WEAK LIFT TO SUPPORT CHANCE
POPS FROM LATE THIS AFTERNOON THROUGH TONIGHT. RAP AND HRRR SEEM
TO HAVE BEST HANDLE ON UPSTREAM CONVECTION EARLY THIS MORNING.
BOTH MODELS WEAKEN CONVECTION AS IT MOVES EAST TODAY BUT STILL
SHOW SOME SCATTERED DEVELOPMENT IN OUR AREA BY LATE AFTERNOON AND
THROUGH THE EVENING. SEVERE WEATHER THREAT LOOKS MINIMAL AS
MUCAPES ONLY IN THE 1-2K J/KG RANGE AT BEST AND 0-3KM SHEAR
BETWEEN 20 AND 30KTS. LACK OF STRONG CONVERGENCE AND OVERNIGHT
TIMING SHOULD ALSO LIMIT DEVELOPMENT. COLD FRONT WILL PUSH SOUTH
BY EARLY TUESDAY MORNING ENDING PCPN CHANCES FROM NORTH TO SOUTH
OVERNIGHT WITH EVEN DRIER AIR WORKING IN.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 349 AM EDT MON JUL 20 2015
A SECOND SURGE OF COOL AIR WILL SPREAD ACROSS THE REGION BEHIND A
COLD FRONT EARLY TUESDAY. A SURFACE HIGH PRESSURE SYSTEM WILL BE
OVER THE REGION FOR THE NEXT SEVERAL DAYS. TEMPERATURES WILL FALL
WELL BELOW NORMAL BEHIND THE COOL FRONT TUESDAY NIGHT...FOLLOWED
BY A GRADUAL MODERATION LATER IN THE WEEK. THE SUBTROPICAL RIDGE
WILL EXTEND WELL INLAND...INTO THE SOUTHERN PLAINS... AND
EVENTUALLY BUILD FURTHER WEST INTO THE SOUTHWEST CONUS. HIGHS HERE
WILL BE IN THE 70S TUESDAY AND WEDNESDAY...RISING INTO THE 80S BY
FRIDAY AS A PORTION OF THE UPPER LEVEL RIDGE TEMPORARILY BUILDS
INTO THE AREA. CONDITIONS SHOULD BE DRY THROUGH FRIDAY...BUT SOME
ENERGY SHOULD BE ABLE TO TOP THE UPPER LEVEL RIDGE AND BRING A
CHANCE FOR THUNDERSTORMS THIS COMING WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 630 AM EDT MON JUL 20 2015
VFR CONDITIONS GENERALLY EXPECTED THROUGH THE PERIOD BUT POCKETS
OF GROUND FOG ARE POSSIBLE THROUGH 13Z. A WEAK COLD FRONT WILL
MOVE THROUGH TONIGHT. THERE IS A SMALL CHANCE FOR SHOWERS OR
THUNDERSTORMS NEAR THIS FRONT BUT LIFT IS WEAK AND CHANCES ARE
TOO LOW FOR INCLUSION IN TAF AT THIS TIME.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...SKIPPER
AVIATION...LASHLEY
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AREA FORECAST DISCUSSION
NWS JACKSON KY
1057 AM EDT MON JUL 20 2015
.UPDATE...
ISSUED AT 1057 AM EDT MON JUL 20 2015
ISOLATED RAIN SHOWERS CONTINUE ACROSS THE CWA. WHILE LATEST HI RES
MODELS HAVE NOT BEEN PERFORMING VERY WELL FOR THE LAST FEW
DAYS...THE HRRR IS ACTUALLY INITIATING QUITE WELL OVER THE LAST
COUPLE HOURS. BASED ON THE LATEST RADAR TRENDS...AS WELL AS THE
LATEST HRRR...DON/T EXPECT THINGS TO REALLY START TICKING UP TO
SCATTERED TO NUMEROUS UNTIL LATE IN THE AFTERNOON. AS SUCH...WENT
AHEAD AND CUT BACK POPS DURING THE REST OF THE MORNING TO SLOW
DOWN THE INCREASE IN COVERAGE. ALSO...LOADED IN THE LATEST
OBSERVATIONAL DATA INTO THE NEAR TERM GRIDS FOR TEMPS...DEW
POINTS...AND WINDS...TO MAKE SURE OUR FORECAST MATCHED UP WITH THE
ONGOING CONDITIONS.
UPDATE ISSUED AT 649 AM EDT MON JUL 20 2015
THE FORECAST IS IN GOOD SHAPE SO FAR THIS MORNING. ISOLATED RAIN
SHOWERS ARE ALREADY MOVING INTO THE AREA FROM THE WEST. THIS TREND
IS EXPECTED TO CONTINUE THROUGHOUT THE MORNING...WITH
THUNDERSTORMS GETTING INTO THE MIX BY 15 OR 16Z. ASIDE FROM
INGESTING THE LATEST OBS DATA INTO THE FORECAST GRIDS...NO CHANGES
TO THE FORECAST WERE NECESSARY.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 301 AM EDT MON JUL 20 2015
SCATTERED SHOWERS AND THUNDERSTORMS ARE BRINGING LOCALLY HEAVY
RAINFALL TO PORTIONS OF EASTERN KENTUCKY THIS OVERNIGHT.
PIKE...ROCKCASTLE...AND LAUREL COUNTIES IN PARTICULAR WERE
EXPERIENCING HEAVY RAIN AT AFD ISSUANCE. ISOLATED TO SCATTERED
SHOWERS AND STORMS WILL LIKELY CONTINUE THROUGH THE NIGHT...WITH A
GRADUAL WEAKENING TREND EXPECTED THROUGH SUN RISE. SCATTERED TO
NUMEROUS SHOWERS AND STORMS ARE EXPECTED TO FIRE UP AGAIN THIS
AFTERNOON...AS A COLD FRONT APPROACHES FROM THE NORTH. SOME OF THE
STORMS THIS AFTERNOON COULD BE STRONG...WITH GUSTY WINDS...LOCALLY
HEAVY RAINFALL AND SMALL HAIL ALL POSSIBLE. SCATTERED STORMS ARE
EXPECTED TO CONTINUE AGAIN THROUGH TUESDAY MORNING. THE SHOWERS
AND STORMS WILL THEN BECOME NUMEROUS AGAIN TUESDAY AFTERNOON AND
EVENING...AS THE COLD FRONT PUSHES SLOWLY ACROSS THE AREA. THE
MODELS IN GENERAL DO NOT HAVE A GOOD HANDLE ON THE CURRENT
WEATHER...SO A MODIFIED BLEND OF MODEL DATA WAS USED TO CREATE THE
FORECAST.
TEMPERATURES THROUGH TOMORROW ARE EXPECTED TO RUN AT OR SLIGHTLY
ABOVE NORMAL TODAY...RIGHT AT NORMAL TOMORROW...AND SEVERAL
DEGREES ABOVE NORMAL TONIGHT. TODAYS HIGHS ARE EXPECTED TO TOP OUT
IN THE MID TO UPPER 80S FOR MOST LOCATIONS...WITH A FEW STRAY
READINGS AT OR JUST ABOVE 90 NOT OUT OF THE QUESTION ALONG THE
TENNESSEE BORDER. TONIGHTS LOWS WILL ONCE AGAIN BE QUITE
BALMY...WITH MIN READINGS IN THE LOWER 70S ON TAP. HIGHS ON
TUESDAY SHOULD COME IN RIGHT ABOUT NORMAL...WITH MAX READINGS IN
THE MID 80S EXPECTED.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 301 AM EDT MON JUL 20 2015
WHILE THE LONG TERM PORTION OF THE FORECAST CERTAINLY LOOKS QUIETER
AND LESS ACTIVE...STILL LOTS OF UNCERTAINTY IN THE FORECAST...ALL
REVOLVING AROUND EXACTLY HOW FAR SOUTH THE FRONTAL BOUNDARY MAKES IT
ON TUESDAY. GFS PUSHES THIS BOUNDARY OFF TO THE SOUTH...WITH DRY
WEATHER ARRIVING FOR THE MIDDLE OF THE WEEK...WHILE THE ECMWF HANGS
UP THE BOUNDARY FARTHER NORTH...KEEPING AT LEAST THE SOUTHERN HALF
OF KENTUCKY WITH A THREAT OF SHOWERS/STORMS THROUGH THE REMAINDER OF
THE WEEK. GIVEN THE ABUNDANCE OF WET WEATHER LATELY AND THE TENDENCY
FOR FRONTS TO NOT MAKE A GOOD PUSH SOUTH THIS TIME OF YEAR...HAVE
OPTED TO KEEP SOME POPS ACROSS SOUTHERN KENTUCKY THROUGH MOST OF THE
WEEK. PLAN TO KEEP THINGS IN THE 20 TO 30 RANGE FOR POPS GIVEN THE
UNCERTAINTY. NORTHERN KENTUCKY...HAS A BETTER SHOT OF HAVING A LONGER
PERIOD OF DRY WEATHER THROUGH THE SECOND HALF OF THE WEEK. MODELS
ARE ALL OVER THE PLACE AS WE HEAD INTO NEXT WEEKEND WITH THE GFS
BRINGING OUR NEXT SYSTEM INTO THE AREA...WHILE THE ECMWF REMAINS
DRY. THUS...WILL JUST STAY WITH A COMPROMISED APPROACH AND GO WITH
SOME LOW POPS FOR SATURDAY INTO SUNDAY.
DESPITE THE MODEL DISAGREEMENTS...IT DOES LOOK LIKE SOME REASONABLE
AGREEMENT ON TEMPERATURES AS NO MATTER THE SOLUTION...WE SHOULD SEE
COOLER TEMPERATURES FOR THE MIDDLE OF THE WEEK AS THE FRONTAL
BOUNDARY SHOULD SET UP SOUTH OF THE AREA...OR EVEN IF IT
DOESN`T...WE WILL SEE MORE CLOUD COVER WHICH WILL ALSO KEEP
TEMPERATURES LOWER. TEMPERATURES WILL BEGIN TO WARM AGAIN HEADING
INTO NEXT WEEKEND AS THE TROUGH OVER THE EAST BREAKS DOWN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 649 AM EDT MON JUL 20 2015
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO AFFECT THE TAF SITES
AFTER 18Z TODAY. LOCALLY HEAVY RAINFALL...STRONG WINDS...AND
FREQUENT LIGHTNING WILL BE THE PRIMARY THREATS WITH ANY
THUNDERSTORMS. CONDITIONS AT THE TAF SITES WILL REMAIN VFR DURING
DRY PERIODS...WITH MVFR TO IFR CONDITIONS POSSIBLE DURING INTENSE
RAIN SHOWERS OR ANY THUNDERSTORMS. THE SHOWERS AND STORMS WILL
PERSIST THROUGH THE END OF THE TAF PERIOD...WITH PEAK ACTIVITY
DURING THE AFTERNOON AND EVENING HOURS TODAY AND TOMORROW.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR KYZ044-050>052-
058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...JMW
SHORT TERM...AR
LONG TERM...AR
AVIATION...AR
AREA FORECAST DISCUSSION
NWS PADUCAH KY
649 AM CDT MON JUL 20 2015
.UPDATE...
ISSUED AT 649 AM CDT MON JUL 20 2015
THE AVIATION SECTION HAS BEEN UPDATED FOR THE 12Z TAF ISSUANCE.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 358 AM CDT MON JUL 20 2015
THE DILEMMA TODAY IS HOW TO RECONCILE 2 MCS/S WITH THE POTENTIAL
FOR A HEAT ADVISORY OVER MUCH OF THE AREA. ONE MCS IS CURRENTLY RAINING
ITSELF OUT OVER OUR REGION...WHILE A SECOND ONE IS MOVING EASTWARD
OUT OF NORTHEAST KANSAS AND WESTERN MISSOURI. THERE IS A CORRIDOR
OF CONVECTION WITH THE POTENTIAL FOR FLASH FLOODING EXTENDING
BETWEEN THE TWO SYSTEMS FROM REYNOLDS COUNTY NORTHWESTWARD.
THE LATEST HRRR HAS A GOOD HANDLE ON THE FIRST MCS...SLOWLY
DISSIPATING IT AS IT MOVES OVER WEST KENTUCKY THROUGH 14Z. IT DOES
NOT HAVE A GOOD HANDLE ON THE CONVECTION FROM REYNOLDS COUNTY
WESTWARD. IT TAKES THE BULK OF THE WESTERN MCS EASTWARD...KEEPING
IT NORTHWEST OF OUR AREA THROUGH 18Z. UNFORTUNATELY...THERE IS
SOME POTENTIAL FOR THE REYNOLDS COUNTY CONVECTION TO PUSH EAST AND
IMPACT AREAS ALONG AND NORTH OF A PIEDMONT TO CAPE GIRARDEAU LINE.
CONTEMPLATED JOINING SGF AND LSX IN ISSUING A FLASH FLOOD WATCH
FOR A PORTION OF SOUTHEAST MISSOURI...BUT RECENT RADAR TRENDS SHOW
ENOUGH EASTWARD MOVEMENT OF THE ENTIRE ZONE THAT IT SHOULD NOT BE
A MAJOR ISSUE IN OUR AREA.
WITH THE RAIN OVER THE AREA SURFACE DEWPOINTS WILL LIKELY HOLD IN
THE MID TO UPPER 70S THROUGH THE DAY. IF THE PRECIPITATION AND THE
ASSOCIATED CLOUD COVER DISSIPATE...TEMPERATURES COULD QUICKLY
CLIMB BACK INTO THE 90S. THE BOTTOM LINE IS THAT HEAT INDICES ARE
FORECAST TO REACH NEAR 105 OVER MOST OF SOUTHEAST MISSOURI...THE
PURCHASE AND LAKES AREAS OF WEST KENTUCKY...AND ADJACENT PORTIONS
OF SOUTHERN ILLINOIS.
CONTEMPLATED ISSUING A HEAT ADVISORY GIVEN THIS FORECAST...BUT
THERE ARE A LOT OF MOVING PARTS THAT HAVE TO COME TOGETHER TO MAKE
IT HAPPEN. CONFIDENCE IS JUST NOT HIGH ENOUGH. IF I WOULD HAVE
ISSUED AN ADVISORY WITH THIS PACKAGE IT WOULD HAVE ONLY BEEN FOR
BUTLER...RIPLEY AND CARTER COUNTIES...WHERE THEY ARE MOST LIKELY
TO SEE A GOOD BIT OF SUNSHINE TODAY. WILL LET THE DAY SHIFT
MONITOR RADAR AND SATELLITE TRENDS AND ISSUE AN ADVISORY WHEN
CONFIDENCE INCREASES ENOUGH.
CONFIDENCE IN CONVECTIVE TRENDS BEYOND THIS MORNING IS QUITE LOW.
THE GENERAL TRENDS ARE FOR BETTER CHANCE POPS OVER THE WESTERN
HALF OF SOUTHERN ILLINOIS THIS AFTERNOON AS THE KS/MO MCS GLANCES
BY THE REGION. TONIGHT A COLD FRONT IS STILL SUPPOSED TO REACH THE
AREA...SO WILL HAVE LIKELY POPS OVER MUCH OF THE REGION.
THE CONSENSUS OF 00Z GUIDANCE HAS THE FRONT OUT OF THE AREA BY
EARLY TUESDAY...SO WOULD NOT BE TERRIBLY SURPRISED IF MUCH IF NOT
ALL OF THE AREA IS DRY TUESDAY THROUGH WEDNESDAY. THE NAM AND GFS
GENERATE SCATTERED CONVECTION ALONG WHAT LOOKS LIKE THE 925MB OR
850MB FRONT OVER THE SOUTHERN OR SOUTHEASTERN HALF OF THE AREA
TUESDAY. THIS SIGNAL WAS THERE 24 HOURS AGO...SO WILL KEEP 30-40
PERCENT POPS FOR MUCH OF THE AREA.
PROBABLY HAVE TOO MUCH POP LEFT OVER TUESDAY NIGHT AND WEDNESDAY.
IF THERE IS TO BE CONVECTION IN THE AREA IN THESE PERIODS IT WOULD
MOST LIKELY BE IN OUR WESTERN SOUTHEAST MISSOURI COUNTIES.
WITH NORTHERLY WINDS EXPECTED TUESDAY THROUGH WEDNESDAY...A
COOLING TREND IS FORECAST. HIGHS WILL RANGE FROM THE LOWER 80S
NORTH TO THE MID 80S SOUTH ON WEDNESDAY. ENJOY!
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 358 AM CDT MON JUL 20 2015
THE LONG TERM PORTION OF THE FORECAST CENTERS AROUND THE BEHAVIOR OF
AN UPPER LEVEL RIDGE OVER THE PLAINS. THE MODELS HAVE SHOWN
VARIATIONS REGARDING HOW QUICKLY /AND TO WHAT EXTENT/ THE RIDGE
EXPANDS EAST OVER THE MISSISSIPPI VALLEY. THE 00Z MODEL SUITE DOES
NOT SHOW ANY MORE MODEL AGREEMENT THAN EARLIER RUNS. TAKING A BLEND
OF ALL THE MODELS...THERE WILL BE A GRADUAL RETURN TO HOTTER AND
MORE HUMID WEATHER ALONG WITH SMALL DAILY PRECIP CHANCES.
AS FAR AS THE DAILY DETAILS...
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...IT APPEARS A FRONTAL
BOUNDARY WILL BECOME STATIONARY OVER OUR REGION. THE NORTHWEST TO
SOUTHEAST ORIENTED BOUNDARY SHOULD BE THE FOCUS FOR SCATTERED
SHOWERS AND STORMS. HIGH PRESSURE OVER THE UPPER OHIO VALLEY WILL
FUNNEL RELATIVELY DRY AIR INTO SOUTHWEST INDIANA AND ADJACENT AREAS.
THEREFORE...POPS WILL BE NO HIGHER THAN SLIGHT CHANCE THERE.
SOUTHWEST OF THE BOUNDARY...RICHER BOUNDARY LAYER MOISTURE WILL
SUPPORT POPS OCCASIONALLY IN THE LIKELY CATEGORY IN PARTS OF
SOUTHEAST MISSOURI. EXTENSIVE CLOUDS AND PRECIP WILL LIMIT HIGHS
TO THE LOWER AND MID 80S...EVEN SOUTH OF THE BOUNDARY.
ON FRIDAY AND FRIDAY NIGHT...RISING 500 MB HEIGHTS ASSOCIATED WITH
THE PLAINS RIDGE WILL TRANSLATE INTO A GRADUAL WARMING AND DRYING
TREND. THE RIDGE WILL NOT BUILD EAST SUFFICIENTLY TO QUASH ALL
CHANCES OF CONVECTION. THERE WILL STILL BE A SMALL CHANCE OF PRECIP
DUE TO THE POTENTIAL FOR IMPULSES IN THE WEAK NORTHWEST FLOW ALOFT.
HIGHS WILL GENERALLY BE AROUND 90 ON FRIDAY...EXCEPT FOR MID TO
UPPER 80S NEAR AND NORTH OF INTERSTATE 64.
SATURDAY THROUGH SUNDAY...THE FLOW PATTERN WILL BECOME VERY WEAK AT
LOWER AND MID LEVELS. ANY EXPANSION OF THE RIDGE WILL BE VERY
SLIGHT. ISOLATED DIURNALLY INDUCED CONVECTION IS POSSIBLE BOTH
DAYS...BUT NOT ENOUGH TO WARRANT POPS IN MOST AREAS. ALONG AND WEST
OF THE MISSISSIPPI VALLEY...WILL MENTION SLIGHT CHANCE POPS DUE TO
THE STRONGER INSTABILITY AND HIGHER DEW POINTS IN THAT AREA. HIGHS
SHOULD GENERALLY BE IN THE LOWER 90S WITH LOWS IN THE LOWER 70S.
&&
.AVIATION...
ISSUED AT 649 AM CDT MON JUL 20 2015
ONE AREA OF SHOWERS AND STORMS WILL PUSH SOUTHEAST OF ALL
TERMINALS IN THE NEXT COUPLE OF HOURS. SOME MVFR RAIN WILL BE
POSSIBLE IN THE MEANTIME. WINDS SHOULD RECOVER TO SOUTHWEST BY
MIDDAY. THE HRRR INDICATES THAT THE NEXT ROUND OF STORMS WILL
ARRIVE AT KCGI AROUND 18Z...AND WILL PROGRESS EASTWARD THROUGH THE
AFTERNOON. CURRENT INDICATIONS ARE THAT TS POTENTIAL WILL BE
CONFINED TO KCGI AND KPAH...WITH ONLY SHOWERS AT KEVV AND KOWB.
CANNOT RULE OUT MORE CONVECTION TONIGHT...BUT CONFIDENCE IS TOO
LOW TO ADD IT TO THE FORECASTS AT THIS TIME. A COLD FRONTAL WIND
SHIFT MAY REACH KCGI AND KEVV BY THE END OF THE PERIOD. WENT ON
THE OPTIMISTIC SIDE WITH CEILINGS AND VISIBILITIES THROUGHOUT.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...DRS
LONG TERM...MY
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1047 AM CDT MON JUL 20 2015
.DISCUSSION...
GENERALLY DRY HOT AND HUMID CONDITIONS EXPECTED AGAIN TODAY AS
HIGH PRES REMAINS ANCHORED OVER THE REGION. A FEW SHOWERS OR TSTMS
WILL BE POSSIBLE MAINLY DURING THE AFTN AND PRIMARILY ACRS
PORTIONS OF ACADIANA AND THE LOWER ATCHAFALAYA BASIN.
MEANWHILE...THE BIGGEST ISSUE WILL BE THE ONGOING HEAT WITH
TEMPERATURES ALREADY NEAR 90 DEGREES AT 10 AM THIS MORNING ON
THEIR WAY TO HIGHS IN THE MIDDLE AND UPPER 90S. COMBINED WITH THE
HUMIDITY...HEAT INDEX VALUES WILL BE WELL ABV 100 DEGREES WITH
SEVERAL LOCATIONS ACRS THE ERN HALF OF THE AREA APPROACHING 110.
THE HEAT ADVISORY REMAINS IN EFFECT FOR AREAS EAST OF AN
ALEXANDRIA TO EUNICE TO PECAN ISLAND LINE THROUGH EARLY THIS
EVENING.
OVERALL...FEW CHANGES TO THE CURRENT FCST. MADE SOME MINOR
ADJUSTMENTS TO THE POP/WX GRIDS TO REFLECT RECENT RADAR
OBS/TRENDS...BUT THESE CHANGES WERE NOT SIGNIFICANT ENOUGH TO
WARRANT AN UPDATE TO THE ZONES. 24
&&
.PREV DISCUSSION... /ISSUED 644 AM CDT MON JUL 20 2015/
AVIATION...VFR WITH LIGHT WINDS WITH THE POSSIBLE EXCEPTION OF
BPT WHERE I LEFT IN THE TEMPO MVFR CIG/VIS FOR THE NEXT COUPLE OF
HOURS...TROPICAL CU UNTIL THE BOUNDARY LAYER MIXES OUT AND SOME
LIGHT FOG POSSIBLE AS DEW POINT SPREAD IS WITHIN A DEGREE.
INCLUDED VCTS THIS AFTERNOON FOR ACADIANA TERMINALS LFT AND ARA.
THE GFS AND HRRR AGREE AS DOES PERSISTENCE.
SWEENEY
PREV DISCUSSION... /ISSUED 347 AM CDT MON JUL 20 2015/
DISCUSSION...
AREA REMAINS ON THE SOUTHERN PERIPHERY OF RIDGE CENTERED NEAR THE
ARKLATEX REGION. TEMPERATURES ARE IN THE MID 70S TO LOWER 80S WITH
JUST SOME HIGH CLOUDS MOVING ACROSS THE AREA. SO FAR THE RADAR IS
CLEAR.
GUIDANCE CONTINUES TO INDICATE LITTLE CHANGE IN THE PATTERN. THERE
IS AN AREA OF DEEPER MOISTURE LOCATED ALONG THE CENTRAL GULF COAST
THAT WILL BE MOVING WEST DURING THE DAY. THIS SHOULD CAUSE AN
INCREASE IN AREAL COVERAGE OF SHOWERS AND THUNDERSTORMS ACROSS
SOUTH CENTRAL LOUISIANA TODAY. OUTSIDE OF THE SHOWERS AND
THUNDERSTORMS...HEAT INDEX VALUES WILL BE GETTING UP OVER 108
ACROSS EASTERN PORTIONS OF THE AREA AND THE CURRENT ADVISORY STILL
LOOKS GOOD.
STILL LOOKS LIKE THE DEEPER MOISTURE WILL CONTINUE TO SPREAD WEST
TUESDAY AND WEDNESDAY. WITH THIS MOISTURE MORE CLOUDS AND A FEW
SHOWERS WILL DIAL BACK THE AFTERNOON HIGHS JUST A TAD. WHILE THERE
ARE RAIN CHANCES...THE POPS ARE STILL BELOW CLIMO FOR THIS TIME OF
YEAR.
FOR LATE WEEK...THE CENTER OF THE RIDGE GETS A LITTLE CLOSER AND
SOMEWHAT DRIER AIRMASS WILL RESULT IN LOWER POPS AND TEMPERATURES
WARMING UP ONCE AGAIN. DEEPER MOISTURE IS FORECAST TO MOVE OVER
DURING THE WEEKEND WITH SLIGHTLY HIGHER RAIN CHANCES...BUT STILL
AT OR SLIGHTLY BELOW CLIMO.
27
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 98 76 96 76 / 10 10 20 10
LCH 94 78 93 78 / 10 10 20 10
LFT 96 78 93 78 / 20 10 30 10
BPT 95 77 94 78 / 10 10 20 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR LAZ028-029-032-033-
043>045-052>055.
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
644 AM CDT MON JUL 20 2015
.AVIATION...VFR WITH LIGHT WINDS WITH THE POSSIBLE EXCEPTION OF
BPT WHERE I LEFT IN THE TEMPO MVFR CIG/VIS FOR THE NEXT COUPLE OF
HOURS...TROPICAL CU UNTIL THE BOUNDARY LAYER MIXES OUT AND SOME
LIGHT FOG POSSIBLE AS DEW POINT SPREAD IS WITHIN A DEGREE.
INCLUDED VCTS THIS AFTERNOON FOR ACADIANA TERMINALS LFT AND ARA.
THE GFS AND HRRR AGREE AS DOES PERSISTENCE.
SWEENEY
&&
.PREV DISCUSSION... /ISSUED 347 AM CDT MON JUL 20 2015/
DISCUSSION...
AREA REMAINS ON THE SOUTHERN PERIPHERY OF RIDGE CENTERED NEAR THE
ARKLATEX REGION. TEMPERATURES ARE IN THE MID 70S TO LOWER 80S WITH
JUST SOME HIGH CLOUDS MOVING ACROSS THE AREA. SO FAR THE RADAR IS
CLEAR.
GUIDANCE CONTINUES TO INDICATE LITTLE CHANGE IN THE PATTERN. THERE
IS AN AREA OF DEEPER MOISTURE LOCATED ALONG THE CENTRAL GULF COAST
THAT WILL BE MOVING WEST DURING THE DAY. THIS SHOULD CAUSE AN
INCREASE IN AREAL COVERAGE OF SHOWERS AND THUNDERSTORMS ACROSS
SOUTH CENTRAL LOUISIANA TODAY. OUTSIDE OF THE SHOWERS AND
THUNDERSTORMS...HEAT INDEX VALUES WILL BE GETTING UP OVER 108
ACROSS EASTERN PORTIONS OF THE AREA AND THE CURRENT ADVISORY STILL
LOOKS GOOD.
STILL LOOKS LIKE THE DEEPER MOISTURE WILL CONTINUE TO SPREAD WEST
TUESDAY AND WEDNESDAY. WITH THIS MOISTURE MORE CLOUDS AND A FEW
SHOWERS WILL DIAL BACK THE AFTERNOON HIGHS JUST A TAD. WHILE THERE
ARE RAIN CHANCES...THE POPS ARE STILL BELOW CLIMO FOR THIS TIME OF
YEAR.
FOR LATE WEEK...THE CENTER OF THE RIDGE GETS A LITTLE CLOSER AND
SOMEWHAT DRIER AIRMASS WILL RESULT IN LOWER POPS AND TEMPERATURES
WARMING UP ONCE AGAIN. DEEPER MOISTURE IS FORECAST TO MOVE OVER
DURING THE WEEKEND WITH SLIGHTLY HIGHER RAIN CHANCES...BUT STILL
AT OR SLIGHTLY BELOW CLIMO.
27
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 98 76 96 76 / 10 10 20 10
LCH 94 78 93 78 / 10 10 20 10
LFT 96 78 93 78 / 30 10 30 10
BPT 95 77 94 78 / 10 10 20 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...HEAT ADVISORY FROM 11 AM THIS MORNING TO 7 PM CDT THIS EVENING
FOR LAZ028-029-032-033-043>045-052>055.
TX...NONE.
GM...NONE.
&&
$$
AVIATION...11
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
721 AM EDT MON JUL 20 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM EDT MON JUL 20 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A WNW FLOW ALOFT
ALONG THE CNDN BORDER E OF AN UPR RDG OVER THE ROCKIES. SHRTWV AND
ASSOCIATED SFC LO EMBEDDED IN THIS FLOW ARE MOVING THRU NW
ONTARIO...WITH ATTENDANT SFC COLD FNT STRETCHING INTO MN. SOME ISOLD
SHOWERS ARE PRESENT JUST AHEAD OF THIS FNT AND MOVING THRU NW LK SUP
TOWARD THE KEWEENAW. BUT WITH AN ABSENCE OF MSTR INFLOW INTO THE
SHRTWV AND NOCTURNAL COOLING...THESE SHOWERS HAVE TENDED TO DIMINISH
WITH TIME TO THE S OF SHARPER DPVA/DEEP LYR QVECTOR CNVGC PASSING TO
THE N CLOSER TO THE SHRTWV TRACK. OTRW...STEADY WSW WINDS AHEAD OF
THE FNT ARE RESULTING IN WELL ABV NORMAL TEMPS EARLY THIS MRNG.
MAIN FCST CONCERNS IN THE SHORT TERM WL BE ON POPS TODAY ASSOCIATED
WITH APRCHG COLD FNT AS WELL AS GUSTY WINDS.
TODAY...SHRTWV MOVING THRU NW ONTARIO JUST N OF LK SUP IS FCST TO
MOVE QUICKLY ESEWD TO NEAR THE QUEBEC/ONTARIO BORDER BY 00Z THIS
EVNG. ATTENDANT COLD FNT IS PROGGED TO SWING THRU THE CWA...REACHING
THE SE ZNS ARND 18Z BEFORE CONTINUING AWAY TO THE SE IN THE AFTN.
WHILE THERE MAY BE SOME ISOLATED SHOWERS THIS MRNG OVER MAINLY THE
NRN TIER CLOSER TO THE SHRTWV TRACK/CORE OF SHARPER FORCING...EXPECT
A MAINLY DRY FROPA BECAUSE THE TIMING WL BE AHEAD OF THE FULL IMPACT
OF DAYTIME HEATING. A BIT CONCERNED THE LATER ARRIVAL EARLY THIS
AFTN OVER THE SE CWA WITH SOME ENHANCED LLVL CNVGC WITH LK BREEZE
OFF LK MI COULD RESULT IN SOME ISOLD SHOWERS/TS THERE AS HINTED AT
BY SOME OF THE HIER RES MODELS...SO DID MENTION SOME SCHC POPS IN
THIS AREA BEFORE MORE VIGOROUS DRYING AND THE ARRIVAL OF LARGER
SCALE DNVA/DEEP LYR QVECTOR DVGC ENDS THE PCPN CHCS BY LATE AFTN.
EXPECT SOME GUSTY WINDS AGAIN TODAY AHEAD OF AND FOLLOWING THE COLD
FROPA WITH H925 WSW WINDS UP TO 25-30 KTS SHIFTING TO THE WNW IN THE
AFTN. EXPECT THE HIEST MAX TEMPS INTO THE 80S OVER THE SCNTRAL. COOL
AIR ADVECTION IN THE WAKE OF THE FROPA WITH H85 TEMPS PROGGED TO
FALL TO NEAR 10C OVER THE NW CWA BY 00Z WL LIMIT THE DAYTIME DIURNAL
TEMP RISE TO THE NW.
TNGT...ANOTHER SHRTWV/SOME MID LVL MSTR ARE FCST TO SWING SE INTO
THE UPR LKS WITHIN DEEPENING UPR TROF. WHILE THERE MAY BE SOME CLDS
ACCOMPANYING THIS DISTURBANCE...NONE OF THE MODELS SHOW ANY PCPN
OVER UPR MI. WL MAINTAIN A DRY FCST DURING PERIOD OF NOCTURNAL
COOLING. OVERNGT LOWS WL BE QUITE A BIT LOWER THAN THIS MRNG WITH
SOME UPR 40S AT SOME OF THE COOL SPOTS. BUT STEADY NW WINDS WL TEND
TO LIMIT THE TEMP DROP.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 340 AM EDT MON JUL 20 2015
IMPACTS...NO SIGNIFICANT IMPACTS ARE WITHIN PREDICTABLE RANGE.
POSSIBILITY FOR STRONG TO SEVERE STORMS OVER PARTS OF THE REGION
LATE FRI INTO EARLY SAT...BUT STILL VERY UNCERTAIN ON THAT ASPECT.
MAY SEE A LIGHT SHOWER OR TWO ON TUE AFTERNOON AS A SHORTWAVE MAY
PASS THROUGH...BUT WILL LEAVE THE FORECAST DRY FOR NOW GIVEN LIMITED
COVERAGE/PRECIP AMOUNT/CONFIDENCE.
MAY SEE SHOWERS AND THUNDERSTORMS ALONG AND/OR NEAR THE WI BORDER
LATE WED INTO THU NIGHT AS MODELS SHOW A WARM FRONT MOVING INTO THE
AREA FROM THE SW ALONG WITH MOISTURE ADVECTION. WILL KEEP POPS SW OF
THE CWA ON WED...BUT WILL CONTINUE TO BRING SLIGHT CHANCE POPS INTO
AREAS ALONG THE WI BORDER WED NIGHT AND THU AS THE FRONT SLOWLY
MOVES NE. TIMING/LOCATION MAY BE CHANGED IF ANY DISTURBANCES FORM
THAT CAUSE THE FRONT/MOISTURE ADVECTION TO SURGE FARTHER N.
THE DISTURBANCE THAT THE WARM FRONT IS TIED TO WILL MOVE ACROSS
MANITOBA CANADA AND HUDSON BAY FRI INTO SUN...DRAGGING A SFC
TROUGH/COLD FRONT THROUGH THE AREA. DEFINITELY SOME DIFFERENCES
BETWEEN MODELS WITH THIS SYSTEM...WITH THE GFS BEING STRONGER AND
CONSIDERABLY FARTHER S THAN THE ECMWF. WILL USE CONSENSUS GUIDANCE
GIVEN THE UNKNOWNS INVOLVED...WHICH WILL SHOW SHOWERS AND
THUNDERSTORMS MOVING W TO E ACROSS THE CWA FROM LATE FRI THROUGH
SAT. SUN LOOKS DRY FOR NOW.
TEMPS WILL BE COOLEST TUE AND WED WITH NEAR TO SLIGHTLY BELOW NORMAL
TEMPS EXPECTED. AN UPPER RIDGE MOVES OVER THE AREA LATE IN THE WEEK
AHEAD OF THE CANADIAN DISTURBANCE...LEADING TO NEAR NORMAL TEMPS THU
AND ABOVE NORMAL TEMPS FRI THROUGH SUN. LOOKS LIKE UPPER RIDGING W
OF THE REGION IS FOR THE MOST PART HERE TO STAY THROUGH THE END OF
JULY...WITH ABOVE NORMAL TEMPS. CFS ALSO POINTS TO ABOVE NORMAL
TEMPS THROUGH MOST OF THE REST OF THE MONTH...WITH BELOW NORMAL
TEMPS TO START AUGUST OFF.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 720 AM EDT MON JUL 20 2015
ALTHOUGH THERE MAY BE AN EXPANSION OF SC TODAY AS SOME MOISTER AIR
ARRIVES FM THE NW FOLLOWING A MORNING COLD FROPA...TIMING DURING
PERIOD OF DIURNAL HEATING SUGGESTS VFR CIGS WL PREVAIL. MIXING
ASSOCIATED WITH THIS HEATING WL ALSO RESULT IN GUSTY WINDS...
ESPECIALLY AT THE MORE EXPOSED CMX LOCATION. WINDS WL DIMINISH THIS
EVNG WITH LOSS OF DAYTIME HEATING/MIXING. VFR CONDITIONS WL CONTINUE
TNGT WITH INFLUX OF DRIER NEAR SFC AIR EVEN IF THERE ARE SOME
LINGERING CLDS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 340 AM EDT MON JUL 20 2015
LOW PRESSURE FROM W ONTARIO TO JUST NW OF JAMES BAY WILL SWING INTO
S HUDSON BAY AND W QUEBEC TODAY WHILE DRAGGING A TROUGH ACROSS LAKE
SUPERIOR. WITH THE TIGHT PRESSURE GRADIENT...25KT WINDS WILL REMAIN
POSSIBLE ACROSS LAKE SUPERIOR.
A LARGE AREA OF HIGH PRESSURE FROM S CENTRAL CANADA THROUGH THE
CENTRAL PLAINS STATES TONIGHT WILL SLOWLY EDGE E...AND BUILD ACROSS
THE UPPER GREAT LAKES THROUGH THURSDAY...WITH WINDS RETURNING TO
AROUND 20KTS OR LESS. VERY PATCHY FOG /MAINLY N/ WILL ALSO DIMINISH
MONDAY. EXPECT A N PLAINS LOW THURSDAY NIGHT TO SHIFT TO N ONTARIO
BY THE END OF THE DAY FRIDAY...WITH A TROUGH PUSHING ACROSS
MINNESOTA AND W LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...KC
MARINE...TITUS
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
645 AM CDT MON JUL 20 2015
.SHORT TERM: (THROUGH LATE THIS AFTERNOON)
ISSUED AT 316 AM CDT MON JUL 20 2015
CONVECTION TRENDS ARE THE PRIMARY FOCUS FOR TODAY`S FORECAST.
LATEST SHORT RANGE GUIDANCE INCLUDING THE RAP, NAM, AND TO A
LESSER EXTENT THE HRRR SHOW THE LINE OF BACKBUILDING THUNDERSTORMS
CURRENTLY OVER SOUTH-CENTRAL MISSOURI CONTINUING AND SLOWLY MOVING
EAST-NORTHEAST THROUGH THE EARLY AND MID MORNING HOURS. THE RAP
SEEMS TO BE HANDLING THIS BEST WITH MASS FIELDS PICKING UP THE
CONVECTION PRETTY WELL AT THIS TIME. NOT SURE HOW FAR EAST-
NORTHEAST THE STORMS WILL GET THIS MORNING...BUT HEAVY RAIN OVER
OUR EASTERN OZARK COUNTIES LOOKS LIKELY SO HAVE EXPANDED THE FLASH
FLOOD WATCH ACCORDINGLY. THE AREA OF STORMS NOW MOVING INTO WEST
CENTRAL/NORTHWEST MISSOURI WILL FURTHER COMPLICATE THE FORECAST.
SHOULD SEE THAT AREA GRADUALLY DIMINISH THIS MORNING AS THE LOW
LEVEL JET WEAKENS, BUT I DON`T THINK IT WILL TOTALLY FALL APART.
SHOULD SEE REDEVELOPMENT IN THE VICINITY OF THE MCV THIS AFTERNOON
AS DIURNAL HEATING REINVIGORATES CONVECTION. COVERAGE IS
UNCERTAIN AT THIS TIME, BUT THINK AT LEAST 40-50 POPS ARE
WARRANTED THIS AFTERNOON.
SECOND CONCERN IS POTENTIAL FOR HEAT INDEX VALUES IN EXCESS OF 100
DEGREES AGAIN TODAY. THIS SEEMS LESS LIKELY THAN PREVIOUS DAYS DUE
TO EXTENSIVE CLOUD COVER FROM CONVECTIVE DEBRIS AND AFTERNOON
THUNDERSTORMS. THOUGH FORECAST HEAT INDEX VALUES COME VERY NEAR
100 DEGREES (AND I CANNOT RULE OUT THERE WON`T BE SOME 100+ DEGREE
READINGS IN A FEW PLACES THIS AFTERNOON), FEEL THERE ARE TOO MANY
FACTORS AGAINST WIDESPREAD 100+ HEAT INDEX VALUES TO ISSUE ANY
HEADLINES AT THIS TIME.
CARNEY
.LONG TERM: (TONIGHT THROUGH SUNDAY)
ISSUED AT 333 AM CDT MON JUL 20 2015
AT THE START OF THE PERIOD TONIGHT, IT LOOKS LIKE THE HIGHEST PROBS
FOR RAIN WILL BE FOR AREAS NEAR I-70 AND INTO SOUTHEAST MO WITH WHAT
SHOULD BE MUCH MORE DIURNALLY DEPENDENT SCATTERED CONVECTION FURTHER
TO THE NORTH. ANOTHER COLD FRONT WILL MOVE THRU OUR REGION THIS
EVENING AND WILL, OVER TIME, SUPPRESS THE MORE WIDESPREAD SHRA/TSRA
OVER OUR SOUTHERN FORECAST AREA TO THE SOUTH WHILE THE NORTHERN
SCATTERED CONVECTION WILL LIKELY DISSIPATE.
HIGH PRESSURE WILL THEN BE THE DOMINANT INFLUENCE OVER MOST OF OUR
REGION TUESDAY MORNING THRU WEDNESDAY AFTERNOON. ENOUGH DRY AIR IS
EXPECTED TO BUILD IN MOST AREAS TO RESULT IN DRY WX WITH NIGHTTIME
MIN TEMPS POSSIBLY CLIPPING THE 50S NORTH OF I-70 WITH LOW 60S
EXPECTED MOST ELSEWHERE. MAX TEMPS ARE EXPECTED TO BE A RELATIVELY
BENIGN LOW-MID 80S. UPPER LEVEL DISTURBANCES ARE ANTICIPATED TO
HAVE JUST ENOUGH MOISTURE TO WORK WITH AS THEY TRAVERSE ACROSS FAR
SOUTHERN MO AND SOUTHERN IL TO RESULT IN CONTINUED CHANCES FOR RAIN
THIS PERIOD.
THE OLD FRONT TO THE SOUTH IS EXPECTED TO PUSH BACK TO THE NORTH
WEDNESDAY NIGHT FOR INCREASING RAIN CHANCES AREAWIDE. AT THIS
POINT...THERE IS GOOD MODEL CONSENSUS ON AMPLIFICATION UPSTREAM TO
THE ALREADY EXISTING MID AND UPPER LEVEL NW FLOW THAT IT LOOKS
LIKE WHERE THE FRONT WINDS UP EARLY THURSDAY MAY BE WHERE IT STAYS
FOR THE REMAINDER OF THE WEEK...RESULTING IN PERSISTENT RAIN CHANCES
FOR LATE WEEK. THE OTHER SOLUTION...WHICH WAS FAVORED UNTIL
RECENTLY...WAS THE FRONT PUSHING NORTH BRIEFLY AS A WARM FRONT...BUT
THE MODELS HAVE BEEN GRADUALLY BACKING AWAY FROM THIS SCENARIO OVER
THE PAST FEW DAYS.
THE AMPLIFIED UPPER LEVEL HIGH TO OUR WEST IS THEN EXPECTED TO
PERSIST THRU THE UPCOMING WEEKEND...AND WHILE TEMPS SHOULD BOUNCE
BACK...THEIR LIKELIHOOD OF GETTING MUCH ABOVE AVERAGE IS LOOKING
SLIMMER BY THE DAY.
TES
&&
.AVIATION: (FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 636 AM CDT MON JUL 20 2015
AREAS OF IFR STRATUS AND FOG WILL RISE TO MVFR AND VFR. EXPECT THE
AREA OF RAIN AND THUNDERSTORMS TO WEAKEN THIS MORNING, BUT
REDEVELOP THIS AFTERNOON. INTENSITY AND AREAL COVERAGE IN STORMS
IS UNCERTAIN AT THIS TIME, WHICH IS WHY I DIDN`T HIT THE
THUNDERSTORMS HARDER IN THE TERMINAL FORECASTS. STORMS SHOULD
PERSIST INTO EARLY EVENING, BUT INDICATIONS ARE THAT THEY SHOULD
BE WEAKENING AFTER 02Z. COULD BE SOME FOG OVERNIGHT TONIGHT, BUT
DID NOT PUT MENTION INTO TAFS DUE TO THE UNCERTAINTIES IN THE
FORECAST.
SPECIFICS FOR KSTL:
SHORT RANGE GUIDANCE IS INDICATING THAT THE STORMS OVER CENTRAL
MISSOURI WILL WEAKEN AS THEY CONTINUE MOVING EAST. THINK THERE
MAY BE SOME LIGHT RAIN REMAINING AS IT MOVES INTO THE STL AREA
AFTER 16Z...BUT I AM NOT CERTAIN OF THIS. EXPECT SCATTERED THUNDERSTORMS
TO REDEVELOP THIS AFTERNOON AND PERSIST INTO THE EARLY
EVENING...WEAKENING/MOVING OUT OF THE AREA BY 02Z.
CARNEY
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...FLASH FLOOD WATCH UNTIL NOON CDT TODAY FOR AUDRAIN MO-BOONE MO-
CALLAWAY MO-COLE MO-CRAWFORD MO-FRANKLIN MO-GASCONADE MO-
IRON MO-JEFFERSON MO-KNOX MO-LEWIS MO-LINCOLN MO-MADISON MO-
MARION MO-MONITEAU MO-MONROE MO-MONTGOMERY MO-OSAGE MO-PIKE
MO-RALLS MO-REYNOLDS MO-SHELBY MO-ST. CHARLES MO-ST.
FRANCOIS MO-ST. LOUIS CITY MO-ST. LOUIS MO-WARREN MO-
WASHINGTON MO.
IL...FLASH FLOOD WATCH UNTIL NOON CDT TODAY FOR ADAMS IL-BOND IL-
BROWN IL-CALHOUN IL-GREENE IL-JERSEY IL-MACOUPIN IL-MADISON
IL-MONROE IL-MONTGOMERY IL-PIKE IL-ST. CLAIR IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
626 AM CDT MON JUL 20 2015
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 316 AM CDT MON JUL 20 2015
REGIONAL RADAR MOSAIC SHOWING A COUPLE AREAS OF CONVECTION TO
CONTEND WITH THIS MORNING. FIRST IS CLUSTER OF STORMS OVER SD
PUSHING INTO THE NRN CWA ALONG A COLD FRONT THAT IS PROGGED TO
PUSH DEEPER INTO THE CNTRL PLAINS LATER TODAY. MEANWHILE A LINE OF
STORMS WAS LIFTING ACROSS KS ON NOSE OF LLVL JET/THETA-E ADV.
LATEST HRRR/RAP13 ARE IN REASONABLE AGREEMENT AREAL COVERAGE WILL
INCREASE AS ACTIVITY MERGES EARLY THIS MORNING...BUT THEN QUICKLY
DISSIPATES BY LATE MORNING WHEN THE BNDRY MOVES SOUTH OF THE CWA.
THE HRRR IS ALSO SHOWING POTENTIAL FOR POST-FRONTAL REDEVELOPMENT
ALONG THE 850MB WARM FRONT/MID LYR AGEOSTROPHIC LIFT MAINLY OVER
THE SRN CWA LATER THIS AFTN. RELATIVELY MILD CONDITIONS ON TAP
THEN THROUGH AT LEAST WED AS AS COOLER AIR MASS REMAINS IN CONTROL
OVER THE REGION. GOING FCST HAS SMALL POPS IN PLACE OVER THE SRN
CWA WED NIGHT ASSOCIATED WITH A WARM FRONT LIFTING OUT OF KS/MO.
WITH LATEST MODELS STILL SUPPORTING POSSIBLE DEVELOPMENT...SEE
LITTLE REASON TO MAKE ANY CHANGES.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 316 AM CDT MON JUL 20 2015
OVERALL THE GFS/ECM/CMC MAY BE IN AGREEMENT IN REGARDS TO LARGE
SCALE FLOW EVOLVING TO A LOW AMPLITUDE RIDGE PATTERN ENCOMPASSING
THE CONUS HEADING INTO NEXT WEEKEND...BUT CONSIDERABLE DIFFERENCES
SEEN IN REGARDS TO SFC FEATURES/FROPA. THIS BEST DEPICTED ON SAT/06Z
WITH PCPN DEVELOPMENT PER THE GFS ASSOCIATED WITH A COLD FRONT
DROPPING INTO THE CNTRL PLAINS. ECM ON THE OTHER HAND AT THAT TIME
DEVELOPS PCPN ASSOCIATED WITH A WARM FRONT LIFTING OUT OF KS. GIVEN
THAT THE EVOLVING PATTERN IS NOT ALL THAT FAVORABLE FOR PCPN
ACTIVITY...HAVE TAKEN THE LIBERTY OF REMOVING POPS FROM MOST OF THE
EXTENDED PDS EXCEPT FOR FRIDAY NIGHT LEAVING TOKEN 20S IN PLACE.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 623 AM CDT MON JUL 20 2015
MORNING SHOWERS/STORMS COULD SKIRT NEAR KOMA/KOFK...AND HAVE
INCLUDED MENTION OF TSRA AT KOMA THIS MORNING. COLD FRONT FOLLOWS
BEHIND THE SHOWERS/STORMS...WITH WINDS BECOMING NORTHWESTERLY AND
INCREASING TO AROUND 10-14KT BY THIS AFTERNOON. MAY SEE SHOWERS OR
AN ISOLATED STORM DEVELOP AGAIN NEAR KOMA/KLNK THIS
AFTERNOON...BUT HAVE KEPT MENTION OUT FOR NOW WITH LOW CONFIDENCE
ON DEVELOPMENT AND LOCATION. WINDS WILL DECREASE AFTER SUNDOWN TO
AROUND 5KT OR LESS.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...DEE
LONG TERM...DEE
AVIATION...MAYES
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
749 AM PDT MON JUL 20 2015
.SYNOPSIS...A DISTURBANCE STRETCHING FROM THE COAST TO THE SOUTHERN
GREAT BASIN WILL AIDE IN SHOWER AND THUNDERSTORM DEVELOPMENT TODAY
THROUGH TUESDAY. STORMS IN THIS TYPE OF ENVIRONMENT CAN PRODUCE
LOCALLY HEAVY RAIN IN A SHORT PERIOD OF TIME AND RESULT IN FLASH
FLOODING. ANYONE PLANNING OUTDOOR ACTIVITIES OR A TRIP IN THE NEXT
COUPLE OF DAYS ARE ENCOURAGED TO REMAIN WEATHER AWARE. BY MID
WEEK...DRIER AIR IS EXPECTED TO SPREAD ACROSS THE REGION BRINGING AN
END TO THUNDERSTORM ACTIVITY THAT WILL LAST INTO THE WEEKEND.
&&
.UPDATE...WATER VAPOR SHOWS THE CENTER OF THE MID/UPPER LEVEL LOW
SWIRLING OFF THE COAST OF CALIFORNIA THIS MORNING WEST OF POINT
CONCEPTION. MEANWHILE ACROSS SOUTHEAST CALIFORNIA THE MID-LEVEL WAVE
AND ASSOCIATED PV MAX THAT HELPED TO TRIGGER THE OVERNIGHT CONVECTION
WAS LIFTING NORTH TOWARD THE NEVADA BORDER. DRIER AIR WAS ALREADY
EVIDENT WORKING ON NORTH.
OVERALL POPS WERE ADJUSTED UP ACROSS MUCH OF LINCOLN, SOUTHERN NYE
AND NORTHERN MOHAVE COUNTIES FOR THE REST OF THIS MORNING BASED ON
THE LATEST RADAR RETURNS. POPS WERE ALSO BUMPED UP ACROSS THE
NORTHWEST CWFA FOR THIS AFTERNOON AND EVENING BASED ON THE HRRR AND
WRF AS THIS AREA SHOULD GET MORE ACTIVE GIVEN THE FEATURES PRESENT
TO PROVIDE FORCING (APPROACHING JET STREAK, LOW OFFSHORE, WAVE
RIDING NORTH). SOME ADJUSTMENTS WERE ALSO MADE FOR TUESDAY TO BETTER
MATCH THE NEIGHBORING WFO`S AND GIVEN WE HAVE A FLASH FLOOD WATCH
OUT.
THE REST OF THE FORECAST LOOKS IN GOOD SHAPE AT THIS TIME.
&&
.AVIATION...FOR MCCARRAN...CLOUD BASES WILL REMAIN BETWEEN 6 AND 11K
FEET THROUGH EARLY THIS EVENING. A FEW SHRA AND POSSIBLY A TSRA THIS
MORNING THOUGH IT APPEARS ANY HEAVIER TSRA ACTIVITY WOULD HOLD OFF
UNTIL LATER THIS AFTERNOON OR EARLY THIS EVENING THAT WOULD DIRECTLY
IMPACT THE AIRPORT COMPLEX. AWAY FROM ANY SHRA/TSRA OR OUTFLOW
BOUNDARIES WINDS WILL MAINLY FAVOR DIURNAL DIRECTIONAL TRENDS
THROUGH TONIGHT. SHOWERS AND THUNDERSTORMS WILL MOST PREVALENT IN
THE BEATTY AND MORMON MESA CORRIDORS WITH ISOLATED SHRA/TSRA IN THE
OTHER APPROACH CORRIDORS.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA AND SOUTHEAST
CALIFORNIA...SHRA/TSRA ACTIVITY WILL SHIFT SLOWLY NORTH TODAY WITH
DRIER CONDITIONS EXPECTED SOUTH OF INTERSTATE 40 BY THIS AFTERNOON.
OUTSIDE OF THUNDERSTORM OUTFLOW, WINDS WILL GENERALLY FOLLOW DIURNAL
DIRECTIONAL TRENDS THROUGH TONIGHT. BASES WILL MAINLY BE BETWEEN 7K
AND 12K FEET LOWERING TO BETWEEN 4K AND 6K FEET NEAR ANY SHRA/TSRA.
&&
.PREVIOUS DISCUSSION...
ISSUED AT 244 AM PDT MON JUL 20 2015
.SHORT TERM...THROUGH WEDNESDAY NIGHT.
TODAY COULD BE AN INTERESTING DAY ACROSS MUCH OF THE AREA,
ESPECIALLY NORTH OF INTERSTATE 40 WITH VARIOUS BOUNDARIES FROM
PREVIOUS DAY CONVECTION PROVIDING FOCUS FOR STORM INITIATION. IN
ADDITION, THE REMNANTS OF DOLORES IS FORECAST TO COMBINE WITH LOW
PRESSURE OFF THE WEST COAST WITH A 50KT JET FORECAST TO DEVELOP
AROUND THE BASE OF THE LOW AND MOVE INTO SOUTHERN CALIFORNIA
BECOMING AN EXTRA SOURCE OF LIFT. MODELS FORECAST DRIER, MORE STABLE
AIR OVER SOUTHERN MOHAVE INTO SOUTHEAST SAN BERNARDINO COUNTY
HEADING INTO THE AFTERNOON HOURS TODAY AND SHOWER ACTIVITY MAY SHUT
DOWN EARLY THERE. A FLASH FLOOD WATCH REMAINS FOR MOST AREAS THROUGH
MID DAY THEN THE SOUTHERN AREAS GET TRIMMED OUT AS THE DRIER AIR
MOVES INTO THE DESERTS FOR THIS AFTERNOON.
THE LOW OFF THE COAST OPENS UP TONIGHT AND CROSSES THE AREA TUESDAY
WITH THE FOCUS FOR SHOWERS/STORMS SHIFTING MAINLY TO INYO COUNTY AND
THE SOUTHERN GREAT BASIN. WEAK INSTABILITY EXTENDS INTO PORTIONS OF
CLARK COUNTY ON TUESDAY AND THE MOUNTAINS COULD SEE A FEW SHOWERS AS
WELL.
BY WEDNESDAY, TROUGHING MOVES TO THE NORTHWEST COAST AND THE
NORTHWEST CWA LIES IN THE RIGHT ENTRANCE REGION OF A 70+ KNOT JET
PROVIDING SOME UPPER LEVEL SUPPORT FOR LINGERING MOISTURE IN THAT
AREA FOR ANOTHER SHOT AT THUNDERSTORMS. DRIER, MORE STABLE AIR WILL
BE IN PLACE ELSEWHERE AND MAINLY DRY CONDITIONS ARE EXPECTED. A
WARMING TREND IS FORECAST THROUGH MID WEEK BUT TEMPERATURES WILL
REMAIN BELOW NORMAL.
.LONG TERM...THURSDAY THROUGH SUNDAY.
LONG TERM STARTS OUT WITH A TROUGH EXTENDING FROM THE THE PAC NW
SOUTHWARD INTO NORTHERN CALIFORNIA. MODELS STILL TRYING TO DEVELOP A
CONVERGENCE ZONE FROM NEAR BISHOP NORTHEAST INTO CENTRAL NEVADA
THURSDAY. ADDED SLIGHTLY HIGHER POPS TO NORTHERN ESMERALDA COUNTY AS
AN ISOLATED SHOWER OR THUNDERSTORM COULD DEVELOP. OTHERWISE, DRIER
SOUTHWEST FLOW WILL TRANSLATE TO A BREEZY AFTERNOON ALONG WITH
WARMER TEMPERATURES.
FRIDAY AND SATURDAY WILL BE DRY AND WARMER YET WITH TEMPERATURES
NEAR SEASONAL NORMALS. FOR SUNDAY...INCREASED POPS ACROSS EASTERN
MOHAVE AS MONSOON MOISTURE COULD SNEAK BACK WEST INTO THE COUNTY.
REMAINDER OF THE AREA LOOKS TO STAY DRY WITH SEASONABLE
TEMPERATURES.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION MAY BE NEEDED
TODAY AND/OR TUESDAY. REPORTS OF FLASH FLOODING, THUNDERSTORM WINDS,
DUST, HAIL AND RELATED DAMAGE AS WELL AS RAINFALL TOTALS ARE
ENCOURAGED. SPOTTER ACTIVATION IS NOT EXPECTED BEYOND WEDNESDAY
THROUGH NEXT WEEKEND.
&&
$$
UPDATE/AVIATION...STACHELSKI
PREVIOUS...SALMEN/PIERCE
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1115 AM EDT MON JUL 20 2015
.SYNOPSIS...A RELATIVELY ACTIVE SUMMER PATTERN...NORTHWEST FLOW
ALOFT...WILL PREVAIL ACROSS THE REGION THROUGH NEXT WEEKEND AS AN
UPPER LEVEL RIDGE STRENGTHENS OVER THE CENTRAL PLAINS.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 1100 AM MONDAY...
...HEAT ADVISORY REMAINS IN EFFECT THIS AFTERNOON...
LATE MORNING UPDATE WILL MAINLY SLOW DOWN THE MIXING TRENDS THIS
AFTERNOON...WHICH WILL STILL RESULT IN MARGINAL HEAT INDICES TO
SUPPORT THE ONGOING ADVISORY.
PREVIOUS DISCUSSION... CENTRAL NC REMAINS ON THE EAST NORTHEAST
PERIPHERY OF AN UPPER LEVEL RIDGE CENTERED OVER THE SOUTH-CENTRAL
CONUS - AT THE SOUTHERN FRINGE OF THE WESTERLIES IN WNW FLOW ALOFT.
IN SUCH A PATTERN...A VARIETY OF ADDITIONAL VARIABLES CAN INFLUENCE
THE DEVELOPMENT/EVOLUTION (OR LACK THEREOF) OF
CONVECTION...INCLUDING UPSTREAM CONVECTION OR THE REMNANTS THEREOF
(MCV`S/OUTFLOW BOUNDARIES)...SMALL AMPLITUDE BAROCLINIC WAVES AT THE
SOUTHERN FRINGE OF THE WESTERLIES...LOW-LEVEL MOISTURE
ADVECTION...DEPTH/DEGREE OF MIXING...ETC. AS A RESULT...CONFIDENCE
IN CONVECTIVE CHANCES/COVERAGE/TIMING THIS AFTERNOON AND EVENING IS
BELOW AVERAGE.
H85 TEMPS OF 18-20C AND STRONG INSOLATION/MIXING CONTINUE TO SUGGEST
HIGHS IN THE MID/UPPER 90S THIS AFTERNOON. HOWEVER...CONFIDENCE IN
SFC DEWPOINTS...RELATIVE HUMIDITY AND HEAT INDICES REMAINS
UNCERTAIN. LOW-LEVEL THERMODYNAMIC PROFILES FCST BY THE GFS/NAM ARE
CONSIDERABLY DIFFERENT FOR THIS AFTERNOON. THE NAM SUGGESTS 16-18C
H85 DEWPOINTS OVER CENTRAL NC...WITH SFC DEWPOINTS RANGING FROM THE
MID 60S (NW) TO ~70F (E/SE). AS A RESULT...THE NAM SUGGESTS MODERATE
DESTABILIZATION AND HEAT INDICES AT/AROUND ADVISORY CRITERIA SOUTH
AND EAST OF THE TRIANGLE. THE GFS INDICATES H85 DEWPOINTS ~14C...
DEEPER MIXING...SFC DEWPOINTS IN THE LOWER 60S...MARGINAL
INSTABILITY LARGELY CONFINED TO THE WEST/NW PIEDMONT...AND LOWER
HEAT INDICES OF 100-103F SOUTH AND EAST OF THE TRIANGLE. SPC
MESOANALYSIS DATA INDICATES A DRY LOW-LEVEL AIRMASS IN PLACE OVER
CENTRAL NC EARLY THIS MORNING WITH H85 DEWPOINTS OF 12-15C (16-17C
ALONG THE COAST AND ALONG/WEST OF THE MOUNTAINS). THOUGH WEAK
WESTERLY FLOW SHOULD ALLOW BETTER LOW-LEVEL MOISTURE TO ADVECT INTO
PORTIONS OF THE WEST/SW PIEDMONT THIS AFTERNOON...THE AFOREMENTIONED
MESOANALYSIS DATA SUGGESTS THERMODYNAMIC PROFILES WILL BE CLOSER TO
THOSE DEPICTED BY THE GFS THAN THE NAM.
TWO SMALL AMPLITUDE WAVES (BAROCLINIC/MCV/OR A COMBINATION THEREOF)
WERE LOCATED UPSTREAM OF THE AREA THIS MORNING...ONE IN WV AND THE
OTHER ALONG THE WESTERN TN/KY BORDER. THE LATEST RAP GUIDANCE
SUGGESTS THE WAVE IN WV WILL TRACK EASTWARD THROUGH CENTRAL/
NORTHERN VA LATE THIS MORNING AND EARLY THIS AFTERNOON...WHILE THE
KY/TN WAVE TAKES A MORE UNCERTAIN COURSE (INTO A WEAKER FLOW REGIME)
EAST SOUTHEAST ACROSS SOUTHWEST NC AND UPSTATE SC LATE THIS
AFTERNOON. THE LATTER WAVE TRACKING INTO WESTERN NC/SC APPEARS MOST
LIKELY TO AID CONVECTIVE DEVELOPMENT THIS AFT/EVE GIVEN EXCELLENT
DIURNAL TIMING AND A TRACK WHICH TAKES IS THROUGH A MORE FAVORABLE
THERMODYNAMIC ENVIRONMENT. GIVEN UNCERTAINTY IN THERMODYNAMIC
PROFILES (AS MENTIONED ABOVE)...UNCERTAINTY IN THE PRECISE
TRACK/TIMING OF THE AFOREMENTIONED WAVES IN ADDITION TO THE
POTENTIAL CONTRIBUTION FROM MESOSCALE FORCING...WILL INDICATE A 20-
30% CHANCE OF CONVECTION...HIGHEST IN THE WEST/SW PIEDMONT AND FAR
NE COASTAL PLAIN. -VINCENT
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 430 AM MONDAY...
...HEAT ADVISORY WILL LIKELY BE NEEDED FOR PORTIONS OF CENTRAL NC...
FORECAST CHALLENGES WILL BE SIMILAR TO TODAY...ALBEIT WITH A BETTER
OVERALL POTENTIAL FOR CONVECTION AS THE WESTERLIES STRENGTHEN
/EXTEND FURTHER SOUTH/ IN RESPONSE TO AMPLIFICATION OF AN UPPER
LEVEL TROUGH OVER PORTIONS OF EASTERN CANADA...THE GREAT LAKES...AND
NEW ENGLAND. LATEST GUIDANCE SUGGESTS DRY CONDITIONS FOR MOST OF THE
DAY...WITH A RAPID INCREASE IN CONVECTIVE POTENTIAL AFTER 21Z AND
THE BEST OVERALL POTENTIAL BETWEEN LATE AFTERNOON AND MIDNIGHT (21-
04Z). EXPECT HIGHS SIMILAR TO TODAY...ALBEIT SLIGHTLY COOLER IN THE
FAR NW PIEDMONT. ANOTHER HEAT ADVISORY WILL LIKELY BE NEEDED...
PERHAPS ALONG/EAST OF THE HWY 1 CORRIDOR (I.E. INCLUDING THE
TRIANGLE)...DEPENDING ON LOW-LEVEL MOISTURE. -VINCENT
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 320 AM MONDAY...
MEDIUM RANGE MODELS ARE IN GENERAL AGREEMENT IN SHOWING A SURFACE
FRONT STALLING NEAR OR JUST TO THE SOUTH OF CENTRAL NC FROM MID TO
LATE WEEK... BEFORE SHIFTING FURTHER SOUTH OVER THE WEEKEND AS A
SURFACE HIGH BUILDS MORE AGGRESSIVELY IN FROM THE NORTH (AS IT
SHIFTS EASTWARD AND EVENTUALLY OFFSHORE) WHILE THE MID LEVEL TROUGH
AXIS OVER THE NORTHEAST PUSHES OFFSHORE. THIS SHOULD ALLOW FOR
MAINLY DIURNAL CHANCES FOR SHOWERS AND STORMS FROM MID TO LATE
WEEK... MAINLY ACROSS SOUTHERN PORTIONS OF THE AREA...INVOF THE
FRONT... WITH GENERALLY DRY WEATHER RETURNING FOR THE WEEKEND (SMALL
CHANCE OF CONVECTION ON SUNDAY... DEPENDING ON THE TIMING OF ANOTHER
NORTHERN STREAM S/W TRACKING ACROSS THE NORTHERN HALF OF THE
COUNTRY).
HIGH TEMPS DURING THE MEDIUM RANGE SHOULD BE NEAR NORMAL... WITH
HIGHS IN THE UPPER 80S TO LOWER 90S. LOW TEMPS WILL FOLLOW A SIMILAR
TREND... GENERALLY UPPER 60S NORTH TO LOWER 70S SOUTH.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 800 AM MONDAY...
24-HR TAF PERIOD: EXPECT VFR CONDITIONS TO PREVAIL THROUGH THE
MAJORITY OF THE TAF PERIOD...ASIDE FROM A SMALL POTENTIAL FOR
SHOWERS/STORMS LATE THIS AFT/EVE...PRIMARILY AT THE INT/GSO
TERMINALS...THOUGH POSSIBLY AT ANY TERMINAL (SEE NEAR TERM
DISCUSSION). EXPECT LIGHT/VARIABLE OR CALM WINDS TO BECOME WESTERLY
AT ~10 KT THIS AFTERNOON...THEN WEAKENING TO 5 KT OR LESS BY
MIDNIGHT.
LONG TERM: WITH AN UPPER LEVEL RIDGE EXPECTED TO PERSIST OVER THE
CENTRAL CONUS AND AN EXTENDED PERIOD OF NW FLOW ALOFT DOWNSTREAM
ACROSS THE APPALACHIANS AND MID-ATLANTIC...EXPECT AN ACTIVE SUMMER-
TIME PATTERN TO PERSIST ACROSS THE REGION...WITH THE PRIMARY
AVIATION HAZARD ASSOCIATED WITH DIURNAL CONVECTION...THOUGH
NOCTURNAL CONVECTION CANNOT BE RULED OUT AT TIMES. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM 1 PM TO 7 PM EDT MONDAY FOR NCZ011-027-028-042-
043-077-078-085-086-088-089.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...MLM/VINCENT
SHORT TERM...VINCENT
LONG TERM...77
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
803 AM EDT MON JUL 20 2015
.SYNOPSIS...A RELATIVELY ACTIVE SUMMER PATTERN...NORTHWEST FLOW
ALOFT...WILL PREVAIL ACROSS THE REGION THROUGH NEXT WEEKEND AS AN
UPPER LEVEL RIDGE STRENGTHENS OVER THE CENTRAL PLAINS.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 400 AM MONDAY...
...HEAT ADVISORY REMAINS IN EFFECT THIS AFTERNOON...
CENTRAL NC REMAINS ON THE EAST NORTHEAST PERIPHERY OF AN UPPER LEVEL
RIDGE CENTERED OVER THE SOUTH-CENTRAL CONUS - AT THE SOUTHERN FRINGE
OF THE WESTERLIES IN WNW FLOW ALOFT. IN SUCH A PATTERN...A VARIETY
OF ADDITIONAL VARIABLES CAN INFLUENCE THE DEVELOPMENT/EVOLUTION (OR
LACK THEREOF) OF CONVECTION...INCLUDING UPSTREAM CONVECTION OR THE
REMNANTS THEREOF (MCV`S/OUTFLOW BOUNDARIES)...SMALL AMPLITUDE
BAROCLINIC WAVES AT THE SOUTHERN FRINGE OF THE WESTERLIES...LOW-
LEVEL MOISTURE ADVECTION...DEPTH/DEGREE OF MIXING...ETC. AS A
RESULT...CONFIDENCE IN CONVECTIVE CHANCES/COVERAGE/TIMING THIS
AFTERNOON AND EVENING IS BELOW AVERAGE.
H85 TEMPS OF 18-20C AND STRONG INSOLATION/MIXING CONTINUE TO SUGGEST
HIGHS IN THE MID/UPPER 90S THIS AFTERNOON. HOWEVER...CONFIDENCE IN
SFC DEWPOINTS...RELATIVE HUMIDITY AND HEAT INDICES REMAINS
UNCERTAIN. LOW-LEVEL THERMODYNAMIC PROFILES FCST BY THE GFS/NAM ARE
CONSIDERABLY DIFFERENT FOR THIS AFTERNOON. THE NAM SUGGESTS 16-18C
H85 DEWPOINTS OVER CENTRAL NC...WITH SFC DEWPOINTS RANGING FROM THE
MID 60S (NW) TO ~70F (E/SE). AS A RESULT...THE NAM SUGGESTS MODERATE
DESTABILIZATION AND HEAT INDICES AT/AROUND ADVISORY CRITERIA SOUTH
AND EAST OF THE TRIANGLE. THE GFS INDICATES H85 DEWPOINTS ~14C...
DEEPER MIXING...SFC DEWPOINTS IN THE LOWER 60S...MARGINAL
INSTABILITY LARGELY CONFINED TO THE WEST/NW PIEDMONT...AND LOWER
HEAT INDICES OF 100-103F SOUTH AND EAST OF THE TRIANGLE. SPC
MESOANALYSIS DATA INDICATES A DRY LOW-LEVEL AIRMASS IN PLACE OVER
CENTRAL NC EARLY THIS MORNING WITH H85 DEWPOINTS OF 12-15C (16-17C
ALONG THE COAST AND ALONG/WEST OF THE MOUNTAINS). THOUGH WEAK
WESTERLY FLOW SHOULD ALLOW BETTER LOW-LEVEL MOISTURE TO ADVECT INTO
PORTIONS OF THE WEST/SW PIEDMONT THIS AFTERNOON...THE AFOREMENTIONED
MESOANALYSIS DATA SUGGESTS THERMODYNAMIC PROFILES WILL BE CLOSER TO
THOSE DEPICTED BY THE GFS THAN THE NAM.
TWO SMALL AMPLITUDE WAVES (BAROCLINIC/MCV/OR A COMBINATION THEREOF)
WERE LOCATED UPSTREAM OF THE AREA THIS MORNING...ONE IN WV AND THE
OTHER ALONG THE WESTERN TN/KY BORDER. THE LATEST RAP GUIDANCE
SUGGESTS THE WAVE IN WV WILL TRACK EASTWARD THROUGH CENTRAL/
NORTHERN VA LATE THIS MORNING AND EARLY THIS AFTERNOON...WHILE THE
KY/TN WAVE TAKES A MORE UNCERTAIN COURSE (INTO A WEAKER FLOW REGIME)
EAST SOUTHEAST ACROSS SOUTHWEST NC AND UPSTATE SC LATE THIS
AFTERNOON. THE LATTER WAVE TRACKING INTO WESTERN NC/SC APPEARS MOST
LIKELY TO AID CONVECTIVE DEVELOPMENT THIS AFT/EVE GIVEN EXCELLENT
DIURNAL TIMING AND A TRACK WHICH TAKES IS THROUGH A MORE FAVORABLE
THERMODYNAMIC ENVIRONMENT. GIVEN UNCERTAINTY IN THERMODYNAMIC
PROFILES (AS MENTIONED ABOVE)...UNCERTAINTY IN THE PRECISE
TRACK/TIMING OF THE AFOREMENTIONED WAVES IN ADDITION TO THE
POTENTIAL CONTRIBUTION FROM MESOSCALE FORCING...WILL INDICATE A 20-
30% CHANCE OF CONVECTION...HIGHEST IN THE WEST/SW PIEDMONT AND FAR
NE COASTAL PLAIN. -VINCENT
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 430 AM MONDAY...
...HEAT ADVISORY WILL LIKELY BE NEEDED FOR PORTIONS OF CENTRAL NC...
FORECAST CHALLENGES WILL BE SIMILAR TO TODAY...ALBEIT WITH A BETTER
OVERALL POTENTIAL FOR CONVECTION AS THE WESTERLIES STRENGTHEN
/EXTEND FURTHER SOUTH/ IN RESPONSE TO AMPLIFICATION OF AN UPPER
LEVEL TROUGH OVER PORTIONS OF EASTERN CANADA...THE GREAT LAKES...AND
NEW ENGLAND. LATEST GUIDANCE SUGGESTS DRY CONDITIONS FOR MOST OF THE
DAY...WITH A RAPID INCREASE IN CONVECTIVE POTENTIAL AFTER 21Z AND
THE BEST OVERALL POTENTIAL BETWEEN LATE AFTERNOON AND MIDNIGHT (21-
04Z). EXPECT HIGHS SIMILAR TO TODAY...ALBEIT SLIGHTLY COOLER IN THE
FAR NW PIEDMONT. ANOTHER HEAT ADVISORY WILL LIKELY BE NEEDED...
PERHAPS ALONG/EAST OF THE HWY 1 CORRIDOR (I.E. INCLUDING THE
TRIANGLE)...DEPENDING ON LOW-LEVEL MOISTURE. -VINCENT
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 320 AM MONDAY...
MEDIUM RANGE MODELS ARE IN GENERAL AGREEMENT IN SHOWING A SURFACE
FRONT STALLING NEAR OR JUST TO THE SOUTH OF CENTRAL NC FROM MID TO
LATE WEEK... BEFORE SHIFTING FURTHER SOUTH OVER THE WEEKEND AS A
SURFACE HIGH BUILDS MORE AGGRESSIVELY IN FROM THE NORTH (AS IT
SHIFTS EASTWARD AND EVENTUALLY OFFSHORE) WHILE THE MID LEVEL TROUGH
AXIS OVER THE NORTHEAST PUSHES OFFSHORE. THIS SHOULD ALLOW FOR
MAINLY DIURNAL CHANCES FOR SHOWERS AND STORMS FROM MID TO LATE
WEEK... MAINLY ACROSS SOUTHERN PORTIONS OF THE AREA...INVOF THE
FRONT... WITH GENERALLY DRY WEATHER RETURNING FOR THE WEEKEND (SMALL
CHANCE OF CONVECTION ON SUNDAY... DEPENDING ON THE TIMING OF ANOTHER
NORTHERN STREAM S/W TRACKING ACROSS THE NORTHERN HALF OF THE
COUNTRY).
HIGH TEMPS DURING THE MEDIUM RANGE SHOULD BE NEAR NORMAL... WITH
HIGHS IN THE UPPER 80S TO LOWER 90S. LOW TEMPS WILL FOLLOW A SIMILAR
TREND... GENERALLY UPPER 60S NORTH TO LOWER 70S SOUTH.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 800 AM MONDAY...
24-HR TAF PERIOD: EXPECT VFR CONDITIONS TO PREVAIL THROUGH THE
MAJORITY OF THE TAF PERIOD...ASIDE FROM A SMALL POTENTIAL FOR
SHOWERS/STORMS LATE THIS AFT/EVE...PRIMARILY AT THE INT/GSO
TERMINALS...THOUGH POSSIBLY AT ANY TERMINAL (SEE NEAR TERM
DISCUSSION). EXPECT LIGHT/VARIABLE OR CALM WINDS TO BECOME WESTERLY
AT ~10 KT THIS AFTERNOON...THEN WEAKENING TO 5 KT OR LESS BY
MIDNIGHT.
LONG TERM: WITH AN UPPER LEVEL RIDGE EXPECTED TO PERSIST OVER THE
CENTRAL CONUS AND AN EXTENDED PERIOD OF NW FLOW ALOFT DOWNSTREAM
ACROSS THE APPALACHIANS AND MID-ATLANTIC...EXPECT AN ACTIVE SUMMER-
TIME PATTERN TO PERSIST ACROSS THE REGION...WITH THE PRIMARY
AVIATION HAZARD ASSOCIATED WITH DIURNAL CONVECTION...THOUGH
NOCTURNAL CONVECTION CANNOT BE RULED OUT AT TIMES. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM 1 PM TO 7 PM EDT MONDAY FOR NCZ011-027-028-042-
043-077-078-085-086-088-089.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...VINCENT
LONG TERM...77
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS MEDFORD OR
827 AM PDT MON JUL 20 2015
.DISCUSSION...ANOTHER MORNING WITH LOW CLOUDS WELL ENTRENCHED
ALONG THE COAST, AND INTO THE COASTAL VALLEYS NORTH OF CAPE
BLANCO. HAVE UPDATED CLOUD FIELDS IN THE FORECAST TO BRING THINGS
IN LINE WITH CURRENT SATELLITE OBSERVATIONS AND THE EXPECTED
TRENDS, BUT MADE VERY LITTLE CHANGES ELSEWHERE.
MAIN FOCUS OF EFFORTS TO DAY WILL BE THE THUNDERSTORM CHANCES OVER
THE NEXT THREE DAYS. THE FIRST ROUND THIS EVENING, LIKELY TO BE
THE WEAKEST OF THE THREE, IS ONLY EXPECTED TO IMPACT AREAS
BETWEEN MEDICINE LAKE AND THE TRINITY ALPS IN SISKIYOU COUNTY,
AND THIS IS SUPPORTED BY THE HIGHER RESOLUTION HRRR AND NAM MODEL
VARIANTS. HOWEVER, CHANCES EXPAND NORTH AND EAST TUESDAY, THEN
MORE SO WEDNESDAY. THE LIMITING FACTOR FOR CONVECTION WOULD APPEAR
TO BE THE TIMING AND STRENGTH OF A TRIGGER FEATURE, AND THIS HAS
THROWN A GOOD DEAL OF UNCERTAINTY INTO THE MIX. FEEL CONFIDENT
THAT ISOLATED STORMS WILL FORM, BUT MUCH LESS SO THAT SCATTERED
DEVELOPMENT WILL OCCUR. WILL EVALUATE LATEST MODEL RUNS AND ADJUST
THE FORECAST AS NECESSARY FOR THE AFTERNOON PACKAGE.
SEE THE PREVIOUS DISCUSSION BELOW FOR ADDITIONAL INFORMATION. -BPN
&&
.AVIATION...FOR THE 20/12Z TAF CYCLE...STRATUS WITH IFR TO LIFR
CIGS/VIS WILL CONTINUE ALONG MUCH OF THE IMMEDIATE COASTLINE,
INCLUDING AT KOTH, INTO THE MORNING, THEN GRADUALLY LIFT. ELSEWHERE,
VFR CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD. /FB
&&
.MARINE...UPDATED 815 AM PDT, MONDAY, 19 JULY 2015... NORTH WINDS
WILL RETURN TODAY AS HIGH PRESSURE REBUILDS FROM THE WEST AND LOW
PRESSURE NUDGES NORTHWARD FROM CALIFORNIA. NORTH WINDS AND SEAS ARE
EXPECTED TO REACH ADVISORY LEVELS SOUTH OF CAPE BLANCO THIS
AFTERNOON THROUGH TUESDAY EVENING BEFORE THEY BEGIN TO SUBSIDE
WEDNESDAY THROUGH THURSDAY. THE WIND ADVISORY AREA IS EXPECTED TO
SHRINK FOR WEDNESDAY TO A PORTION OF THE AREA SOUTH OF CAPE BLANCO
BEYOND 10 NAUTICAL MILES WEST OF GOLD BEACH AND POINT SAINT GEORGE,
WHILE ADVISORY LEVEL SEAS WILL BE SLOWER TO SUBSIDE. WINDS AND SEAS
ARE EXPECTED TO BE MOST HAZARDOUS LATE TUESDAY AFTERNOON THROUGH MID
EVENING. HIGH PRESSURE OFFSHORE IS EXPECTED TO SHIFT INLAND SOME
LATER THIS WEEK CAUSING THESE NORTH WINDS TO WEAKEN. /FB
&&
.FIRE WEATHER...UPDATED 600 AM PDT, MONDAY 18 JULY 2015...MOISTURE
AND WEAK DISTURBANCES MOVING UP FROM THE SOUTH WILL BRING A SLIGHT
CHANCE FOR THUNDERSTORMS IN SOUTHERN SISKIYOU AND SOUTHERN MODOC
COUNTIES THIS AFTERNOON AND EVENING. THUNDERSTORM COVERAGE IS
EXPECTED TO INCREASE ON TUESDAY AS ADDITIONAL MID LEVEL MOISTURE AND
DISTURBANCE MOVE INTO THE AREA FROM THE SOUTH. WITH THE BEST
POTENTIAL FOR SCATTERED STORMS ON TUESDAY NEAR AND NORTHEAST OF
MOUNT SHASTA AND OVER EASTERN AREAS, ESPECIALLY ZONES 284, 285,
SOUTHEAST 624 AND SOUTHERN 625. PRECIPITABLE WATER WILL NOT BE AS
HIGH AS WHEN THE LAST ROUND OF STORMS WENT THROUGH AROUND 2 WEEKS
AGO. MOREOVER STORMS ARE EXPECTED TO MOVE WEST TO EAST QUICKLY AT
10 TO 15 MPH ON TUESDAY RESULTING IN ONLY LIGHT TO MODERATE RAIN.
A FIRE WEATHER WATCH WAS ISSUED EARLIER TO REFLECT THE POTENTIAL FOR
SCATTERED THUNDERSTORM COVERAGE ON TUESDAY. SEE DETAILED HAZARD ON
OUR HOMEPAGE FOR THE ACTUAL LOCATION.
ON WEDNESDAY, THE UPPER TROUGH WILL BRING A MARINE PUSH INLAND WITH
SEVERAL DEGREES OF COOLING AND BREEZY SOUTHWEST TO WEST FLOW. THE
STRONGEST WINDS ARE EXPECTED FROM THE CASCADES EAST WITH WINDS OF 10
TO 15 MPH AND GUSTS UP TO 30 MPH. MODELS CONTINUE TO INDICATE A
POTENTIAL FOR THUNDERSTORMS INTO WEDNESDAY EAST OF THE CASCADES IN
OREGON AND FROM CENTRAL SISKIYOU COUNTY EASTWARD INTO MODOC COUNTY.
/FB
&&
.PREV DISCUSSION... /ISSUED 625 AM PDT MON JUL 20 2015/
UPDATED AVIATION AND FIRE WEATHER SECTIONS.
DISCUSSION...TODAY WILL FEATURE ONE MORE ROUND OF WARM TEMPERATURES
ACROSS INLAND PORTIONS OF THE FORECAST AREA...WITH READINGS
EXPECTED TO PEAK THIS AFTERNOON ABOUT 5 DEGREES ABOVE NORMAL
VALUES. MIDLEVEL FLOW WILL SWITCH TO SOUTHERLY OVER NORTHERN
CALIFORNIA...AND THIS WILL USHER IN ENOUGH MOISTURE...LOOSELY
CONNECTED TO REMNANTS OF TROPICAL STORM DOLORES...TO SUPPORT A
SLIGHT CHANCE OF THUNDERSTORMS OVER SISKIYOU AND MODOC COUNTIES.
THE SLIGHT CHANCE OF STORMS CONTINUES OVERNIGHT DUE TO NAM12 H7-H5
MUCAPE IN THE HUNDREDS AND STEEP UPPER LEVEL LEVEL RATES. A WELL-
DEFINED MARINE LAYER WILL CONTINUE TO AFFECT THE COAST MUCH OF
TODAY...WITH COASTAL VALLEYS SEEING SUNSHINE IN THE AFTERNOON.
ON TUESDAY MORE MOISTURE WILL FEED INTO NORTHERN CALIFORNIA AND WILL
ACT IN CONCERT WITH COOLING TEMPERATURES ALOFT...SOME DEFORMATION
ASSOCIATED WITH THE APPROACHING UPPER TROUGH...AND WEAK IMPULSE
ALOFT TO GENERATE THE POTENTIAL FOR SCATTERED THUNDERSTORMS. THE
GFS AND NAM ARE IN GOOD AGREEMENT WITH THE AXIS OF MOST
SIGNIFICANT INSTABILITY...WITH BOTH SHOWING SWATHS OF -3C 850MB
COMPUTED LI VALUES...AND LITTLE IN THE WAY OF CONVECTIVE
INHIBITION. ADDITIONALLY...THE HIGH-RES ARW AND NMM MODELS INFER
SCATTERED AFTERNOON THUNDERSTORMS FROM EASTERN SISKIYOU COUNTY
INTO MODOC AND SOUTHERN KLAMATH AND LAKE COUNTIES. IN SHORT...THIS
SUPPORTS A FIRE WEATHER WATCH...FOUND AT RFWMFR. THE TRIGGER
CONTINUES TO BE THE WEAKEST INGREDIENT IN THIS THUNDERSTORM
RECIPE...BUT BELIEVE THE OTHER INGREDIENTS ARE STRONG ENOUGH TO
ACT ON EVEN A WEAK TRIGGER. ONE NOTE IS THAT STORM MOTION WILL BE
TO THE EAST AT ABOUT 15KT IN MODOC AND LAKE COUNTIES...LIMITING
WETTING RAIN POTENTIAL THERE ASSOCIATED WITH THE STORMS.
WEDNESDAY WILL BE SHARPLY COOLER OVER THE CWA...WITH TEMPERATURES
DROPPING TO 5 TO 10 DEGREES BELOW NORMAL. THE DAY SHOULD START OUT
CLOUDY IN MOST AREAS WEST OF THE CASCADES AS THE UPPER TROUGH LIFTS
AND USHERS IN MARINE STRATUS ALL THE WAY TO THE CASCADE FOOTHILLS.
CLOUDS WILL CLEAR OUT BY THE AFTERNOON AND BREEZY CONDITIONS ARE
EXPECTED MOST AREAS. THUNDERSTORM CHANCES CONTINUE ON WEDNESDAY
AFTERNOON FOR THE SOUTHEAST PORTION OF THE CWA...THOUGH SHOULD BE
LIMITED IN COVERAGE DUE TO LESS MOISTURE AND INSTABILITY.
ANOTHER COOL DAY ON THURSDAY WILL GIVE WAY TO WARMING CONDITIONS
FRIDAY AND INTO THE WEEKEND AS TEMPERATURES REACH BACK UP TO NEAR
NORMAL READINGS...UNDER THE INFLUENCE OF A BUILDING RIDGE OVER THE
DESERT SW.
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR ORZ624-625.
CA...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR CAZ281-284-285.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS FROM 5 PM THIS AFTERNOON TO 5 AM
PDT THURSDAY FOR PZZ356-376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 2 PM THIS AFTERNOON
TO 5 AM PDT THURSDAY FOR PZZ356-376.
$$
BPN/FJB/NSK
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1003 AM EDT MON JUL 20 2015
.SYNOPSIS...
A COLD FRONT EXTENDING FROM LAKE ONTARIO TO IOWA THIS MORNING WILL
MOVE SOUTH INTO THE REGION TODAY. A SECOND STRONGER FRONT WILL
PASS THROUGH THE REGION LATE TUESDAY. EXPECT PERIODS OF SHOWERS
AND THUNDERSTORMS AHEAD OF THE FRONTS...THEN DRY WEATHER WITH LESS
HUMID AND COOLER AIR BEHIND THE BOUNDARY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 955 AM EDT MONDAY...
SHOWERS ACROSS THE AREA ARE OCCURRING IN TWO DISTINCT AREAS. THERE
ARE WEAK AND ISOLATED SHOWERS HEADING EASTWARD THROUGH PARTS OF
BATH AND ALLEGHANY COUNTIES OF VIRGINIA. THERE ARE MORE
SUBSTANTIAL SHOWERS...AND A FEW THUNDERSTORMS...HEADING SOUTHEAST
THROUGH THE NORTHERN MOUNTAINS OF NORTH CAROLINA FROM NORTHEAST
TENNESSEE. COVERAGE WILL CONTINUE TO BE MINIMAL THROUGH THE
REMAINDER OF THE MORNING HOURS AND ALSO THE EARLY AFTERNOON. LOOK
FOR COVERAGE IN INCREASE ONCE WE REACH THE MID AFTERNOON...AND
CONTINUE INTO THE EVENING HOURS. NO NOTABLE CHANGES HAVE BEEN MADE
TO THE FORECAST HIGH TEMPERATURES. HOWEVER...SOME MINOR
ADJUSTMENTS WERE MADE TO THE HOURLY TEMPERATURES THROUGH THE NEXT
FEW HOURS BASED UPON CURRENT OBSERVATIONS AND EXPECTED TRENDS.
AS OF 400 AM EDT MONDAY...
500 MB SHORT WAVE MOVING INTO WEST VIRGINIA WILL BRING SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS INTO THE WESTERN COUNTY WARNING
AREA THIS MORNING. HRRR AND LOCAL WRF SHOWED SOME INDICATIONS THAT
PRECIPITATION MAY SURVIVE ACROSS THE NORTHERN COUNTY WARNING AREA
BUT OVERALL TREND WILL BE FOR SHOWERS AND THUNDERSTORMS TO WEAKEN
BEFORE 12Z/8AM.
WEST TO NORTHWEST SURFACE AND LOW LEVEL WIND EXPECTED TODAY WHICH
FAVORS DEVELOPMENT OF ADDITIONAL SHOWERS AND THUNDERSTORMS AGAIN
IN THE MOUNTAINS THIS AFTERNOON. WITH LEE TROUGHING IN
PLACE...FAR EASTERN PIEDMONT MAY ALSO HAVE BETTER COVERAGE.
WEST TO NORTHWEST WINDS WILL CREATE DOWNSLOPING AND MIXING BY THIS
AFTERNOON...ENOUGH TO LOWER DEW POINTS INTO THE 60S IN THE
FOOTHILLS AND KEEP THE HEAT INDEX EAST OF THE BLUE RIDGE FROM
REACHING ADVISORY LEVELS. NO HEAT ADVISORY PLANNED AT THIS TIME.
MORE ORGANIZED SHOWERS AND THUNDERSTORMS WILL DEVELOP AHEAD OF
THE FRONT ACROSS THE OHIO VALLEY THIS AFTERNOON. THESE STORMS WILL
MOVE INTO THE WESTERN COUNTY WARNING AREA LATE TONIGHT.
USED A BLEND OF BIAS CORRECTED MET/MAV GUIDANCE FOR MAXIMUM
TEMPERATURES TODAY AND LOWS TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 AM EDT MONDAY...
A COLD FRONT WILL MOVE OVER THE OHIO RIVER VALLEY TUESDAY MORNING
AND IS EXPECTED TO JUMP TO THE LEE TROUGH PERCHED ACROSS THE
PIEDMONT IN THE AFTERNOON. A PREFRONTAL SHORT WAVE WILL TRACK ACROSS
KENTUCKY TUESDAY MORNING...BRINGING SHOWERS AND POSSIBLY A FEW
RUMBLES OF THUNDER...TO THE FAR WESTERN FORECAST AREA (BLUEFIELD VA-
LEWISBURG WV). LOW AND MID LEVEL FLOW TURNS WESTERLY
QUICKLY...REDUCING SHOWER ACTIVITY MOVING EAST TO THE BLUE RIDGE.
MORNING SHOWERS MAY NOT COMPLETELY FADE AS THEY APPROACH THE BLUE
RIDGE AS THIS WAVE TRACKS EAST OVER THE AREA. AS THE FRONT JUMPS TO
THE LEE TROUGH IN THE AFTERNOON...A NEW LINE OF CONVECTION WILL
FORM. ALL MODELS ARE HAVING A TOUGH TIME PINPOINTING WHERE THIS LINE
WILL INITIATE. BASED ON WHERE MODELS HAVE THE LEE TROUGH
POSITIONED...THIS LINE WILL BE EAST OF HWY 29...POSSIBLY EAST OF HWY
501. THE DEW POINT FRONT LAGS BEHIND AND THE MOUNTAINS MAY NOT SEE
SHOWERS CLEARING THE AREA UNTIL LATE IN THE EVENING...WITH CLEARING
IN THE PIEDMONT DURING THE EARLY MORNING HOURS WEDNESDAY. BY SUNRISE
WEDNESDAY MORNING...THE DEW POINT FRONT SHOULD BE SOUTH INTO NORTH
CAROLINA. A WEAK BUT COOL AREA OF HIGH PRESSURE WILL MOVE OVER THE
REGION WEDNESDAY...KEEPING THE REGION DRY FOR A COUPLE OF DAYS.
TUESDAY SHOULD BE THE LAST OF THE HOT DAY FOR THIS WEEK. DEPENDING
ON THE TIMING OF SHOWERS...HIGH TEMPERATURES ACROSS THE MOUNTAINS
WILL RANGE IN THE 80S...WITH LOWER TO MID 90S EAST. WEDNESDAY
TEMPERATURES WILL FALL BACK CLOSER TO NORMAL AS THE FRONT SINKS
SOUTH.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 350 PM EDT SUNDAY...
BROAD TROUGHING ACROSS THE NORTHEAST U.S. WILL DOMINATE THE
WEATHER AT THE BEGINNING OF THE PERIOD. THE FRONTAL
BOUNDARY/BAROCLINIC ZONE SHOULD BE LOCATED FROM THE MIDWEST INTO
THE SOUTHEAST STATES...HOPEFULLY SAFELY ENOUGH SOUTH OF OUR AREA
TO INHIBIT CONVECTION OF MUCH EXTENT. HOWEVER...WILL NEED TO WATCH
THURSDAY AS THERE IS YET ANOTHER UPSTREAM WAVE RIDING ALONG THE
BAROCLINIC ZONE THAT COULD BUCKLE THE BOUNDARY BACK FAR ENOUGH
NORTH TO ALLOW CONVECTION TO DRIFT BACK INTO THE SOUTHWEST PART OF
THE CWA...ESPECIALLY THE NW NC MOUNTAINS.
THERE IS BETTER PROBABILITY/CONFIDENCE THAT ONCE THIS FEATURE
PASSES BY TO THE SOUTH FRIDAY...WE WILL SEE GREATER POTENTIAL FOR
THE FRONTAL BOUNDARY TO DRIFT FURTHER SOUTH AND TAKE THE
CONVECTION WITH IT.
A WEAK UPPER LOW CUTS OFF ACROSS THE SOUTHEAST STATES BY THE
WEEKEND AND STALLS. BY SAT-SUN...THE UPPER RIDGE AMPLIFIES ACROSS
THE CENTRAL U.S. AND WE QUICKLY RETURN BACK TO A MORE UNSTABLE
NORTHWEST FLOW AND THE POTENTIAL FOR UPSTREAM CONVECTIVE COMPLEXES
TO REACH THE REGION.
850MB TEMPS DROP BELOW +20C THU-SAT...CREEPING BACK ABOVE +20C
ACROSS MUCH OF THE CWA BY THE END OF NEXT WEEKEND. DEWPOINTS DROP
INTO THE 50S ACROSS THE NORTHERN PART OF THE CWA BY THU
MORNING...WHICH SHOULD BE QUITE REFRESHING...BEFORE THEY CREEP
BACK UP INTO THE 60S TO LOW 70S BY THE WEEKEND. NEAR TO SLIGHTLY
BELOW NORMAL TEMPS THU-FRI...SHOULD RETURN TO ABOVE NORMAL LEVELS
BY THE WEEKEND.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
AS OF 1730 AM EDT MONDAY...
ISOLATED SHOWERS SHOWN ON RADAR WILL MOVE EAST AND WEAKEN BEFORE
14Z. NO IMPACT IS EXPECTED FOR LOCAL AIRPORTS. THERE WILL BE MORE
SHOWERS AND THUNDERSTORMS THIS AFTERNOON AS UPPER ENERGY CROSSES
THE AREA. EXPECT HIGHER PROBABILITY OF PRECIPITATION IN THE WEST.
LOWER CONFIDENCE THAT STORMS WILL IMPACT KLYH AND KDAN. THREAT OF
SHOWERS AND THUNDERSTORMS WILL DIMINISH AFTER SUNSET. REMOVED THE
CHANCE OF PRECIPITATION FROM THE FORECAST AFTER 03Z/11PM.
EXTENDED AVIATION DISCUSSION...
TUESDAY WILL SEE MORE WIDESPREAD THUNDERSTORMS SINCE A FRONT WILL
SINK SWD IN RESPONSE TO STRONGER UPPER TROUGH OVER THE GREAT
LAKES AND NORTHEAST UNITED STATES. THIS FRONT SINKS SOUTH OF THE
AREA FOR WEDNESDAY AND THURSDAY AND BUCKLES NWD AGAIN FRIDAY. SO
FOR NOW WILL EXPECT OVERALL VFR CONDITIONS OUTSIDE CONVECTION
TUESDAY...THEN FOG/STRATUS POSSIBLE WED/THU MORNING IN THE BCB/LWB
AREA PENDING HOW DRY THE AIR GETS BEHIND THIS FRONT. THEN MORE
SHOWERS AND STORMS POSSIBLE FRIDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/DS
SHORT TERM...RCS
LONG TERM...RAB
AVIATION...AMS/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
731 AM EDT MON JUL 20 2015
.SYNOPSIS...
A COLD FRONT EXTENDING FROM LAKE ONTARIO TO IOWA THIS MORNING WILL
MOVE SOUTH INTO THE REGION TODAY. A SECOND STRONGER FRONT WILL
PASS THROUGH THE REGION LATE TUESDAY. EXPECT PERIODS OF SHOWERS
AND THUNDERSTORMS AHEAD OF THE FRONTS...THEN DRY WEATHER WITH LESS
HUMID AND COOLER AIR BEHIND THE BOUNDARY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 400 AM EDT MONDAY...
500 MB SHORT WAVE MOVING INTO WEST VIRGINIA WILL BRING SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS INTO THE WESTERN COUNTY WARNING
AREA THIS MORNING. HRRR AND LOCAL WRF SHOWED SOME INDICATIONS THAT
PRECIPITATION MAY SURVIVE ACROSS THE NORTHERN COUNTY WARNING AREA
BUT OVERALL TREND WILL BE FOR SHOWERS AND THUNDERSTORMS TO WEAKEN
BEFORE 12Z/8AM.
WEST TO NORTHWEST SURFACE AND LOW LEVEL WIND EXPECTED TODAY WHICH
FAVORS DEVELOPMENT OF ADDITIONAL SHOWERS AND THUNDERSTORMS AGAIN
IN THE MOUNTAINS THIS AFTERNOON. WITH LEE TROUGHING IN
PLACE...FAR EASTERN PIEDMONT MAY ALSO HAVE BETTER COVERAGE.
WEST TO NORTHWEST WINDS WILL CREATE DOWNSLOPING AND MIXING BY THIS
AFTERNOON...ENOUGH TO LOWER DEW POINTS INTO THE 60S IN THE
FOOTHILLS AND KEEP THE HEAT INDEX EAST OF THE BLUE RIDGE FROM
REACHING ADVISORY LEVELS. NO HEAT ADVISORY PLANNED AT THIS TIME.
MORE ORGANIZED SHOWERS AND THUNDERSTORMS WILL DEVELOP AHEAD OF
THE FRONT ACROSS THE OHIO VALLEY THIS AFTERNOON. THESE STORMS WILL
MOVE INTO THE WESTERN COUNTY WARNING AREA LATE TONIGHT.
USED A BLEND OF BIAS CORRECTED MET/MAV GUIDANCE FOR MAXIMUM
TEMPERATURES TODAY AND LOWS TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 AM EDT MONDAY...
A COLD FRONT WILL MOVE OVER THE OHIO RIVER VALLEY TUESDAY MORNING
AND IS EXPECTED TO JUMP TO THE LEE TROUGH PERCHED ACROSS THE
PIEDMONT IN THE AFTERNOON. A PREFRONTAL SHORT WAVE WILL TRACK ACROSS
KENTUCKY TUESDAY MORNING...BRINGING SHOWERS AND POSSIBLY A FEW
RUMBLES OF THUNDER...TO THE FAR WESTERN FORECAST AREA (BLUEFIELD VA-
LEWISBURG WV). LOW AND MID LEVEL FLOW TURNS WESTERLY
QUICKLY...REDUCING SHOWER ACTIVITY MOVING EAST TO THE BLUE RIDGE.
MORNING SHOWERS MAY NOT COMPLETELY FADE AS THEY APPROACH THE BLUE
RIDGE AS THIS WAVE TRACKS EAST OVER THE AREA. AS THE FRONT JUMPS TO
THE LEE TROUGH IN THE AFTERNOON...A NEW LINE OF CONVECTION WILL
FORM. ALL MODELS ARE HAVING A TOUGH TIME PINPOINTING WHERE THIS LINE
WILL INITIATE. BASED ON WHERE MODELS HAVE THE LEE TROUGH
POSITIONED...THIS LINE WILL BE EAST OF HWY 29...POSSIBLY EAST OF HWY
501. THE DEW POINT FRONT LAGS BEHIND AND THE MOUNTAINS MAY NOT SEE
SHOWERS CLEARING THE AREA UNTIL LATE IN THE EVENING...WITH CLEARING
IN THE PIEDMONT DURING THE EARLY MORNING HOURS WEDNESDAY. BY SUNRISE
WEDNESDAY MORNING...THE DEW POINT FRONT SHOULD BE SOUTH INTO NORTH
CAROLINA. A WEAK BUT COOL AREA OF HIGH PRESSURE WILL MOVE OVER THE
REGION WEDNESDAY...KEEPING THE REGION DRY FOR A COUPLE OF DAYS.
TUESDAY SHOULD BE THE LAST OF THE HOT DAY FOR THIS WEEK. DEPENDING
ON THE TIMING OF SHOWERS...HIGH TEMPERATURES ACROSS THE MOUNTAINS
WILL RANGE IN THE 80S...WITH LOWER TO MID 90S EAST. WEDNESDAY
TEMPERATURES WILL FALL BACK CLOSER TO NORMAL AS THE FRONT SINKS
SOUTH.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 350 PM EDT SUNDAY...
BROAD TROUGHING ACROSS THE NORTHEAST U.S. WILL DOMINATE THE
WEATHER AT THE BEGINNING OF THE PERIOD. THE FRONTAL
BOUNDARY/BAROCLINIC ZONE SHOULD BE LOCATED FROM THE MIDWEST INTO
THE SOUTHEAST STATES...HOPEFULLY SAFELY ENOUGH SOUTH OF OUR AREA
TO INHIBIT CONVECTION OF MUCH EXTENT. HOWEVER...WILL NEED TO WATCH
THURSDAY AS THERE IS YET ANOTHER UPSTREAM WAVE RIDING ALONG THE
BAROCLINIC ZONE THAT COULD BUCKLE THE BOUNDARY BACK FAR ENOUGH
NORTH TO ALLOW CONVECTION TO DRIFT BACK INTO THE SOUTHWEST PART OF
THE CWA...ESPECIALLY THE NW NC MOUNTAINS.
THERE IS BETTER PROBABILITY/CONFIDENCE THAT ONCE THIS FEATURE
PASSES BY TO THE SOUTH FRIDAY...WE WILL SEE GREATER POTENTIAL FOR
THE FRONTAL BOUNDARY TO DRIFT FURTHER SOUTH AND TAKE THE
CONVECTION WITH IT.
A WEAK UPPER LOW CUTS OFF ACROSS THE SOUTHEAST STATES BY THE
WEEKEND AND STALLS. BY SAT-SUN...THE UPPER RIDGE AMPLIFIES ACROSS
THE CENTRAL U.S. AND WE QUICKLY RETURN BACK TO A MORE UNSTABLE
NORTHWEST FLOW AND THE POTENTIAL FOR UPSTREAM CONVECTIVE COMPLEXES
TO REACH THE REGION.
850MB TEMPS DROP BELOW +20C THU-SAT...CREEPING BACK ABOVE +20C
ACROSS MUCH OF THE CWA BY THE END OF NEXT WEEKEND. DEWPOINTS DROP
INTO THE 50S ACROSS THE NORTHERN PART OF THE CWA BY THU
MORNING...WHICH SHOULD BE QUITE REFRESHING...BEFORE THEY CREEP
BACK UP INTO THE 60S TO LOW 70S BY THE WEEKEND. NEAR TO SLIGHTLY
BELOW NORMAL TEMPS THU-FRI...SHOULD RETURN TO ABOVE NORMAL LEVELS
BY THE WEEKEND.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 1730 AM EDT MONDAY...
ISOLATED SHOWERS SHOWN ON RADAR WILL MOVE EAST AND WEAKEN BEFORE
14Z. NO IMPACT IS EXPECTED FOR LOCAL AIRPORTS. THERE WILL BE MORE
SHOWERS AND THUNDERSTORMS THIS AFTERNOON AS UPPER ENERGY CROSSES
THE AREA. EXPECT HIGHER PROBABILITY OF PRECIPITATION IN THE WEST.
LOWER CONFIDENCE THAT STORMS WILL IMPACT KLYH AND KDAN. THREAT OF
SHOWERS AND THUNDERSTORMS WILL DIMINISH AFTER SUNSET. REMOVED THE
CHANCE OF PRECIPITATION FROM THE FORECAST AFTER 03Z/11PM.
EXTENDED AVIATION DISCUSSION...
TUESDAY WILL SEE MORE WIDESPREAD THUNDERSTORMS SINCE A FRONT WILL
SINK SWD IN RESPONSE TO STRONGER UPPER TROUGH OVER THE GREAT
LAKES AND NORTHEAST UNITED STATES. THIS FRONT SINKS SOUTH OF THE
AREA FOR WEDNESDAY AND THURSDAY AND BUCKLES NWD AGAIN FRIDAY. SO
FOR NOW WILL EXPECT OVERALL VFR CONDITIONS OUTSIDE CONVECTION
TUESDAY...THEN FOG/STRATUS POSSIBLE WED/THU MORNING IN THE BCB/LWB
AREA PENDING HOW DRY THE AIR GETS BEHIND THIS FRONT. THEN MORE
SHOWERS AND STORMS POSSIBLE FRIDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...RCS
LONG TERM...RAB
AVIATION...AMS/WP
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1011 AM CDT MON JUL 20 2015
.UPDATE...
500 MB SHORTWAVE TROUGH OVER NORTHWEST IOWA INTO NORTHEAST
NEBRASKA IS EXPECTED TO SLIDE SOUTHEASTWARD THIS AFTERNOON AND
EARLY THIS EVENING...CLIPPING SOUTHERN WISCONSIN. A COLD FRONT
WILL ALSO MOVE SOUTHEAST THROUGH THE AREA LATER THIS AFTERNOON AND
EARLY THIS EVENING. AREA OF SHOWERS WITH A FEW THUNDERSTORMS BEING
HELPED ALONG BY THESE FEATURES ACROSS SOUTHWEST WISCONSIN INTO
CENTRAL IOWA.
MESOSCALE MODELS WERE MIXED WITH INITIALIZATION OF CURRENT
FEATURES...AND DIFFER WITH HOW MUCH OF THIS ACTIVITY MOVES THROUGH
THE AREA THIS AFTERNOON. RAP SOUNDINGS SHOWING DECENT HANDLE ON
SURFACE DEW POINTS...WITH TALL AND SKINNY MEAN LAYER CAPES UP TO
800 J/KG OR SO. DEEP LAYER SHEAR IS MODEST...WITH POOR MID LEVEL
LAPSE RATES.
GIVEN THE ABOVE...EXPECTING SCATTERED SHOWERS AND SOME STORMS
ACROSS THE AREA THIS AFTERNOON...ENDING BY EARLY EVENING...AS THE
FRONT AND SHORTWAVE TROUGH MOVE THROUGH. SOME GUSTY WINDS MAY
OCCUR WITH THE STORMS. BROKEN CLOUD COVER IS EXPECTED THROUGH MOST
OF THE REST OF THE DAY...WHICH MAY HOLD DOWN HIGHS A BIT. MAY HAVE
TO ADJUST THESE DOWNWARD FROM THE CURRENT MID 80S.
&&
.AVIATION/18Z TAFS/...
BROKEN VFR CLOUDS WILL CONTINUE TO SPREAD ACROSS THE AREA TODAY
INTO EARLY THIS EVENING. COLD FRONT IS EXPECTED TO SLIDE SOUTHEAST
TOWARD THE AREA THIS AFTERNOON...THEN ACROSS THE AREA EARLY THIS
EVENING. SCATTERED SHOWERS AND THUNDERSTORMS ARE ANTICIPATED ALONG
AND AHEAD OF THE FRONT...MAINLY IN THE AFTERNOON.
GIVEN SOME UNCERTAINTY WITH TIMING AND AREAL COVERAGE...USED
VICINITY SHOWER WORDING IN TAFS FOR NOW. MVFR VISIBILITIES AND
CEILINGS ARE POSSIBLE IN ANY STORMS. GUSTY SOUTHWEST WINDS WILL
DEVELOP AND LINGER THROUGH THE AFTERNOON. GUSTS TO AROUND 20 KNOTS
ARE EXPECTED.
WINDS WILL SHIFT TO THE NORTHWEST BEHIND THE FRONT TONIGHT AND
LINGER ON TUESDAY. CLOUDS WILL GRADUALLY MOVE OUT OF THE AREA
LATER THIS EVENING...WITH MOSTLY CLEAR SKIES LATER TONIGHT INTO
TUESDAY.
&&
.MARINE...
SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE NEARSHORE WATERS OF
LAKE MICHIGAN UNTIL 10 PM CDT THIS EVENING. GUSTY SOUTHWEST WINDS
ARE EXPECTED TO DEVELOP OVER THE NEXT HOUR OR TWO...AND LINGER
UNTIL EARLY THIS EVENING. FREQUENT GUSTS UP TO AROUND 25 KNOTS ARE
ANTICIPATED...ESPECIALLY NEAR THE SHORELINE. HIGH WAVES WILL
REMAIN OVER THE OPEN WATERS...WITH THE OFFSHORE FLOW.
&&
.PREV DISCUSSION... /ISSUED 338 AM CDT MON JUL 20 2015/
SHORT TERM...
TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM.
THE MAIN FOCUS FOR TODAY IS ON THE CHANCES FOR CONVECTION AHEAD OF A
COLD FRONT WHICH WILL PUSH THROUGH THE REGION BY THIS EVENING.
A CLUSTER OF SHOWERS OUT IN NORTHWEST IOWA AND SOUTHWEST MINNESOTA
ASSOCIATED WITH A MID LEVEL SHORT WAVE TROUGH IS EXPECTED TO
DIMINISH IN COVERAGE/INTENSITY OVER THE NEXT FEW HOURS...BUT COULD
CLIP PORTIONS OF SOUTH CENTRAL WISCONSIN THIS MORNING...SO HAVE PUT
SOME HIGH CHANCES IN THERE FOR THE SHOWERS. INSTABILITY WILL BE ON
THE INCREASE TODAY AHEAD OF THE COLD FRONT WHICH IS CURRENTLY IN
CENTRAL MINNESOTA AND WILL EXTEND FROM NORTHEAST WISCONSIN TO WEST
CENTRAL WISCONSIN AROUND NOON TODAY. HAVE LIKED THE RAP THIS
MORNING AND ITS TRENDS WITH SURFACE DEW POINTS/INSTABILITY...WHICH
IS ON THE LOWER SIDE AT 1000 J/KG MLCAPE WHEN COMPARED TO THE 20.00Z
NAM/GFS WHICH ARE PUSHING CLOSER TO 2000-3000 J/KG THANKS TO
FORECAST SURFACE DEW POINTS OVER 70F. SHOULD THE RAP THERMAL
PROFILE PAN OUT...IT WOULD MEAN A SKINNY CAPE SCENARIO WITH
DECREASING SHEAR DUE TO THE LEAD SHORTWAVE TROUGH DEPARTING TO THE
SOUTHEAST. THEREFORE...OUTSIDE OF A FEW HIGHER GUSTS POSSIBLE DUE
TO THE DRY SOUNDING...AM NOT ANTICIPATING MUCH IN THE WAY OF SEVERE
WEATHER FOR TODAY. AFTER THE COLD FRONT MOVES THROUGH...SKIES WILL
CLEAR OUT WITH WINDS GOING LIGHT TONIGHT.
LONG TERM...
TUESDAY THROUGH FRIDAY... FORECAST CONFIDENCE HIGH.
DRIER AIR WILL SETTLE INTO SOUTHERN WI ON TUESDAY. A HIGH AMPLITUDE
UPPER RIDGE OVER THE CENTER OF THE COUNTRY AND A SPRAWLING UPPER LOW
OVER ONTARIO AND QUEBEC CANADA WILL SET UP A BLOCKING PATTERN AND WE
WILL BE UNDER A DRY NORTHWEST FLOW PATTERN THROUGH MUCH OF THE WEEK.
SURFACE HIGH PRESSURE WILL TAKE HOLD OVER THE GREAT LAKES REGION AND
WE CAN EXPECT LIGHT WESTERLY WINDS. MAX TEMPERATURES WILL ONLY BE IN
THE UPPER 70S TUESDAY AND GRADUALLY MODIFY INTO THE LOWER 80S BY
FRIDAY... EXCEPT SLIGHTLY COOLER BY THE LAKESHORE.
THE GFS ALLOWS A SHORTWAVE TO MAKE IT ACROSS A HIGH-AMPLITUDE RIDGE
OVER THE UPPER MIDWEST AND BRING PRECIP TO WI ON THURSDAY. THE ECMWF
SHOWS A WEAKER SHORTWAVE THAT RUNS INTO THE DRY AIR AND KEEPS THE
AREA DRY. TRENDED TOWARD THE DRIER FORECAST FOR THU SINCE PRECIP
WILL HAVE A HARD TIME OVERCOMING THE DRY AIR IN PLACE.
SATURDAY... FORECAST CONFIDENCE MEDIUM.
THERE IS BETTER AGREEMENT FOR A STRONGER SHORTWAVE TROUGH TO REACH
THE GREAT LAKES ON FRI NIGHT OR SATURDAY AND BRING SHOWER AND
THUNDERSTORM CHANCES TO WI. THE GFS IS STRONGER AND BRINGS A BOWLING
BALL UPPER LOW THROUGH SOUTHERN CANADA WITH THE SURFACE TROUGH
CROSSING WI FRIDAY NIGHT. THE ECMWF HAS A WEAKER UPPER TROUGH AND
DELAYS THE SURFACE TROUGH UNTIL SATURDAY AFTERNOON. A FRIDAY NIGHT
FRONTAL PASSAGE WOULD KEEP SEVERE THUNDERSTORM CHANCES DOWN.
SUNDAY AND MONDAY... FORECAST CONFIDENCE MEDIUM.
A RIDGE OVER THE SOUTHWEST STATES WILL KEEP US IN A FAIRLY DRY
NORTHWEST FLOW PATTERN EARLY NEXT WEEK. WEAK SHORTWAVES RIDING OVER
THE RIDGE WILL LEAD TO INTERMITTENT PRECIP CHANCES. EXPECT MAX
TEMPERATURES TO REMAIN IN THE LOWER 80S DURING THIS TIME.
AVIATION/12Z TAFS/...
THE MAIN FOCUS AT THE TAF SITES IS ON THE POTENTIAL FOR SHOWERS AND
THUNDERSTORMS TODAY AHEAD OF A COLD FRONT. WINDS WILL BECOME GUSTY
AS WELL OUT OF THE SOUTHWEST AHEAD OF THE FRONT WITH SOME GUSTS
POSSIBLY REACHING THE 20-25KT RANGE. ANY SHOWERS OR THUNDERSTORMS
COULD PRODUCE SOME WINDY CONDITIONS AS WELL...BUT THINK THAT FLIGHT
CONDITIONS SHOULD MAINLY STAY VFR GIVEN HOW DRY CONDITIONS ARE.
SKIES WILL CLEAR OUT AND WINDS WILL GO LIGHT THIS EVENING AS THE
FRONT PUSHES OFF TO THE SOUTHEAST.
MARINE...
THE MAIN CONCERN FOR TODAY IS WITH THE GUSTY OFF SHORE WINDS WHICH
LOOK LIKE THEY WILL PUSH INTO THE 20 TO 30KT RANGE...PARTICULARLY
FURTHER TO THE NORTH. WAVES WILL BE THE HIGHEST OUT TOWARD THE OPEN
WATER DUE TO THE WEST-SOUTHWEST WINDS. MAY HAVE TO PUSH OUT A SMALL
CRAFT ADVISORY DUE TO THESE POTENTIALLY HIGHER GUSTS.
OTHERWISE...SOME SHOWERS AND THUNDERSTORMS ARE POSSIBLE TODAY AS
WELL WHEN A COLD FRONT DROPS THROUGH THE REGION. SOME GUSTY WINDS
MAY ACCOMPANY THESE SHOWERS AND STORMS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR LMZ643>645.
&&
$$
UPDATE...WOOD
TODAY/TONIGHT AND AVIATION/MARINE...HALBACH
TUESDAY THROUGH SUNDAY...MRC
AREA FORECAST DISCUSSION
NWS PUEBLO CO
325 PM MDT MON JUL 20 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 243 PM MDT MON JUL 20 2015
CURRENTLY...A HEALTHY AMOUNT OF CLOUD COVER THROUGH MUCH OF THE DAY
HAS PUT A DAMPER ON MUCH OF THE POTENTIAL ACTIVITY FOR TODAY...AND
CONVECTION CURRENTLY OVER THE HIGHER TERRAIN WAS SLOW TO START. NO
REPORTS OF HEAVY RAINFALL AS OF YET...AS SOUNDINGS THIS MORNING
CONFIRMED THAT THE GREATER AMOUNT OF MOISTURE IS AVAILABLE IN NM.
TEMPS HAVE WARMED INTO THE UPPER 70S TO UPPER 80S ACROSS THE PLAINS
AS OF 3 PM...AND IN THE 60S AND 70S FOR THE HIGH VALLEYS. SFC WINDS
ACROSS THE PLAINS HAVE BEEN GENERALLY OUR OF THE EAST...BUT WITHIN
THE PAST COUPLE OF HOURS HAVE SHIFTED TO A MORE S-SE DIRECTION.
TONIGHT...A FLAT RIDGE OF HIGH PRESSURE OVER THE SOUTHERN U.S. WILL
STAY THAT WAY FOR ANOTHER DAY OR SO...AS A COUPLE OF UPPER
DISTURBANCES CROSS THE GREAT BASIN AND NORTHERN ROCKIES. HI RES
MODELS INCLUDING THE HRRR INDICATE THAT THE CURRENT ACTIVITY WILL
CONTINUE WELL INTO THE NIGHT...WITH SOME SPILL OVER ACROSS THE I25
CORRIDOR THIS EVENING BETWEEN 22Z AND 06Z. OTHERWISE...FEEL THAT
ACTIVITY WILL BE MAINLY TIED TO THE MTS. SO...NOT A LOT OF
IMPRESSIVE STORMS JUST YET AND THE UPPER W-SW FLOW HAS BEEN KEEPING
STORMS MOVING...CUTTING DOWN ON THE FLASH FLOOD THREAT. PRECIPITABLE
WATER AMOUNTS SOUTH OF THE STATE LINE IN NM ARE WELL OVER AN
INCH...BUT UP NORTH IN THE PUB CWA ARE CLOSER TO .6 TO .7 OF AN
INCH. OF COURSE...THE THREAT OF FLASH FLOODING FOR AREA BURN SCARS
REMAINS THIS EVE AND WILL HAVE TO BE MONITORED.
TOMORROW...THE ACTIVE PATTERN CONTINUES AS A SHORTWAVE CROSSES
WY...PROVIDING THE TRIGGER FOR A RAPID INCREASE IN CONVECTION OVER
ALL OF THE MTS AND ADJACENT PLAINS BY 15Z. AS THIS WAVE CONTINUE
EAST...THE BAND OF ENHANCED LIFT WILL CROSS THE I25 CORRIDOR AND E
PLAINS THROUGH THE AFTN HRS...AND AN ATTEMPT HAS BEEN MADE IN THE
POP GRIDS TO SHOW THIS. STRONG TO SEVERE STORMS WILL ALSO BE A
POSSIBILITY TOMORROW AFTN AS THIS WAVE CROSSES THE AREA...AS THERE
WILL BE PLENTY OF MOISTURE AND SHEAR ON TAP...AND SPC HAS PAINTED
MUCH OF THE E PLAINS IN THE MARGINAL AREA. MAX TEMPS TOMORROW MAY BE
A DEGREE OR TWO COOLER...BUT SHOULD STILL WARM INTO THE 70S AND 80S
FOR THE PLAINS...60S AND 70S FOR THE HIGH VALLEYS. MOORE
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 243 PM MDT MON JUL 20 2015
TUESDAY NIGHT...
AN AREA OF SHOWERS AND STORMS WILL LIKELY BE MOVING ACROSS THE
EASTERN PLAINS AS A DISTURBANCE OVER THE REGION CONTINUES TO MOVE
EAST. LOCALLY HEAVY RAIN WILL BE POSSIBLE AND STRONG TO MARGINALLY
SVR STORMS WILL BE POSSIBLE GIVEN THE MODEST CAPE AND SHEAR THAT
WILL BE OVER THE PLAINS.
WEDNESDAY THROUGH FRIDAY...
OVERALL IT WILL BE DRY AND WARM AS MONSOON TAP WILL BE DECREASED
AS HEIGHTS RISE ACROSS THE REGION. MAX TEMPS OVER THE PLAINS WILL
RISE BACK UP INTO THE 90S. WE WILL STILL SEE SOME ISOLD TSRA
ACROSS THE REGION...BUT OVERALL COVERAGE WILL BE LESS THAN THE
LAST FEW DAYS.
SATURDAY INTO MONDAY..
GUIDANCE INDICATES MONSOON MOISTURE WILL ONCE AGAIN BE ON THE
UPSWING AS SW FLOW CONTINUES ALOFT AND A TROUGH TO OUR WEST MOVES
TOWARDS THE REGION. TEMPS WILL COOL SLIGHTLY AND SHOWERS AND
STORMS SHOULD INCREASE DURING THE AFTERNOON AND EVENING TIME
PERIODS. /HODANISH
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 243 PM MDT MON JUL 20 2015
CONVECTION IS EXPECTED TO CONTINUE ACROSS THE HIGHER TERRAIN THIS
EVE...BUT SFC WINDS SHIFTING TO A MORE S-SE DIRECTION THIS AFTN WILL
ALLOW A FEW OF THE STORMS TO CROSS THE I25 CORRIDOR. THEREFORE...AN
ISOLATED STORM PROBABLE FOR KCOS OR KPUB...BUT MORE SO OUTFLOW
WINDS. KALS WILL HAVE A BETTER CHANCE FOR SHOWER AND STORM ACTIVITY
IN THE VCNTY THROUGH 07Z. LOOK FOR VFR CONDITIONS OVER THE NEXT 24
HRS FOR MUCH OF THE AREA...WITH MVFR TO IFR CONDITIONS AT TIMES OVER
THE MT PASSES ASSOCIATED WITH STRONGER STORMS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...MOORE
LONG TERM...HODANISH
AVIATION...MOORE
AREA FORECAST DISCUSSION
NWS NEW YORK NY
154 PM EDT MON JUL 20 2015
.SYNOPSIS...
A SURFACE TROUGH WILL SET UP OVER THE AREA TODAY. A COLD FRONT
WILL APPROACH ON TUESDAY...AND MOVE THROUGH TUESDAY EVENING. HIGH
PRESSURE WILL THEN BUILD IN FROM WEDNESDAY THROUGH FRIDAY...MOVING
OFF THE COAST SATURDAY. A WEAK COLD FRONT APPROACHES SATURDAY
NIGHT AND SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
TEMPERATURES CONTINUE TO WARM INTO THE LOWER AND MIDDLE 90S. THE
WARMEST LOCATIONS ACROSS THE CWA AT NOON ARE ACROSS LONG ISLAND.
THE ISLIP MACARTHUR AIRPORT HAS REACHED 92 DEGREES AS OF
NOON...WHICH IS THE FIRST TIME SINCE JULY 20TH 2013 THAT THE
TEMPS HAS REACHED 90 OR HIGHER AT THIS LOCATION. TEMPS ARE IN THE
UPPER 80S AND LOWER 90S ELSEWHERE. HEAT INDICES ARE HIGHEST ACROSS
LONG ISLAND AND COASTAL CONNECTICUT...IN THE MIDDLE AND UPPER 90S.
DEW POINTS ARE IN THE MIDDLE 60S ACROSS THE NYC AND NJ METRO SO
HEAT INDICES ARE IN THE LOWER TO MIDDLE 90S.
HAVE ADJUSTED HOURLY TEMPS TO BETTER REFLECT THE LATEST
OBSERVATIONAL TRENDS. THIS CONTINUES TO GIVE HIGHS IN THE LOWER TO
MIDDLE 90S. MAX HEAT INDICES WILL BE IN THE UPPER 90S FOR THE NYC
METRO AND NEAR 100 ACROSS NE NJ.
SURFACE TROUGH IS BEGINNING TO REDEVELOP ACROSS THE NYC METRO. SEA
BREEZES HAVE ALSO DEVELOPS ACROSS THE SOUTH SHORE OF LONG ISLAND
AND COASTAL CT. THESE SEA BREEZES WILL SLOWLY MOVE INLAND THROUGH
THE AFTERNOON. THE LATEST RAP AND HRRR MODELS CONTINUE TO BRING
THIS BOUNDARY THROUGH THE NYC METRO LATE THIS AFTERNOON. IT IS
POSSIBLE THIS IS OVERDONE. HOWEVER...IF IT DOES MOVE THROUGH...DEW
POINTS COULD BOUNCE BACK UP INTO THE LOWER 70S.
SO FAR...NO CONVECTION HAS DEVELOPED ON THE SEA BREEZE
CONVERGENCE. STILL FEEL THAT THIS CONVERGENCE IS THE ONLY FOCUS
FOR ANY CONVECTIVE DEVELOPMENT. INSTABILITY IS VERY HIGH...2000 TO
3000 J/KG TODAY. ANY STRONGER CELL COULD PRODUCE STRONG WIND GUSTS
WITH INVERTED V SOUNDINGS INDICATED BY BUFKIT.
&&
.SHORT TERM /TUESDAY/...
A COLD FRONT CURRENTLY OVER THE NRN PLAINS WILL APPROACH...BUT THE
FEATURE APPEARS TO HAVE SLOWED SOMEWHAT FROM PREVIOUS PROGS. THIS
COULD RESULT IN A COMPLETELY DRY DAY ACROSS THE CWA. HAVE TRIMMED
BACK POPS TO SCHC AS A RESULT...KEEPING IN MIND THAT THERE MAY BE
SOME RESIDUAL BOUNDARIES IN THE AREA. HOT TEMPS BUT THE HX ATTM
BLW 95 IN THE CITY. THE ADVY WAS THEREFORE NOT EXTENDED. TEMPS DO
HAVE A TENDENCY TO RISE HIGHER THAN MODEL GUIDANCE AHEAD OF A
COLD FRONT...SO THIS WILL NEED TO BE WATCHED.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
BROAD UPPER TROUGH AND ASSOCIATED CLOSED LOW ACROSS EASTERN CANADA
MOVES SLOWLY EAST TUESDAY INTO TUESDAY NIGHT. A WEAK SHORTWAVE
ROTATES THROUGH THE TROUGH AND EAST OF THE REGION BY LATER TUESDAY
NIGHT. THE SHORTWAVE WILL BE ACCOMPANIED BY A WEAK COLD FRONT.
SCATTERED CONVECTION WILL BE POSSIBLE WITH THE FRONT. TIMING OF THE
COLD FRONT IS CONSISTENT AMONG THE GUIDANCE. HOWEVER...GUIDANCE
BRINGS THE FRONT THROUGH MAINLY DRY TUESDAY EVENING. WILL HAVE JUST
SLIGHT CHANCE POPS AT THIS TIME.
HIGH PRESSURE BUILDS IN SLOWLY FROM THE WEST TUESDAY NIGHT INTO
SATURDAY WITH A HIGHLY AMPLIFIES UPPER FLOW AS A RIDGE BUILDS INTO
THE CENTRAL UNITED STATES AND CANADA WITH A PACIFIC NORTHWEST
TROUGH AND THE EASTERN CANADIAN TROUGH.
THE UPPER RIDGE WEAKENS BY THE WEEKEND WITH THE UPPER TROUGH
SHIFTING OFF THE CANADIAN MARITIME AND NORTHEAST COAST. THIS ALLOWS
A NORTHERN STREAM SHORTWAVE TO MOVE NORTH OF THE REGION SATURDAY
NIGHT INTO SUNDAY. A WEAKENING COLD FRONT MOVES SLOWLY INTO THE AREA
FOR SUNDAY. NEXT CHANCE OF PRECIPITATION WILL BE SUNDAY NIGHT INTO
NEXT MONDAY AND WILL HAVE LOW CHANCE POPS AT THIS TIME.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
A TROUGH OF LOW PRESSURE WILL REMAIN NEARLY STATIONARY ACROSS THE
AREA THROUGH EARLY TONIGHT. A COLD FRONT WILL APPROACH ON TUESDAY
PASSING EAST OF THE AREA TUESDAY NIGHT.
PREVAILING WEATHER WILL BE VFR. TEMPO MVFR IN CIGS AND VSBY POSSIBLE
IN AFTN AND EVE ISOLATED TO SCT TSTMS EACH DAY. CONFIDENCE IS TOO
LOW TO INCLUDE IN TAFS.
WINDS...THE SEA BREEZE FRONT BETWEEN KJFK AND KLGA EXTENDING EAST
ACROSS CENTRAL LONG ISLAND WILL STRUGGLE NORTH AND WEST. SW WINDS
ARND 10 KT ARE FCST ARND 19Z KLGA. HOWEVER...WINDS WILL REMAIN
MAINLY W ACROSS METRO NJ AND THE LOWER HUDSON VALLEY LESS THAN 10
KT.
WINDS WILL BECOME LIGHT AND VARIABLE AFT SUNSET.
SW WINDS ARE FCST TO DEVELOP BETWEEN 15Z AND 18Z ARND 10 KT ON
TUE.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT:
HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR ISOLATED TSTMS 18Z-
00Z.
KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR LATER DEVELOPMENT
OF SEABREEZE. ISOLATED TSTM POSSIBLE 18Z-00Z.
KEWR FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR ISOLATED TSTM 18Z-
00Z.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR ISOLATED TSTM 18Z-
00Z.
KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR ISOLATED TSTM 18Z-
00Z.
KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR ISOLATED TSTM 18Z-
00Z.
.OUTLOOK FOR 00Z TUESDAY AFTN THROUGH SATURDAY...
.TUE AFTN AND EVE...POSSIBLE MVFR IN ISOLATED-SCT TSTMS.
.WED-SAT...VFR.
&&
.MARINE...
NO CHANGES AT THIS TIME.
DUE TO A WEAK PRES GRAD OVER THE WATERS...WINDS AND SEAS BLW SCA
LVLS THRU TUE. A COLD FRONT MOVES ACROSS THE FORECAST WATERS
TUESDAY EVENING. HIGH PRESSURE BUILDS SLOWLY EAST TUESDAY NIGHT
THROUGH THURSDAY AND MOVES OVER THE WATERS FRIDAY. WIND AND SEAS
REMAIN BELOW SMALL CRAFT LEVELS TUESDAY NIGHT THROUGH FRIDAY.
&&
.HYDROLOGY...
ANY TSTMS THAT DEVELOP TODAY WILL BE SLOW MOVING. AS A
RESULT...THERE IS AN ISOLD FLASH FLOOD THREAT. NO SIGNIFICANT
PRECIPITATION EXPECTED TUESDAY AND TUESDAY EVENING. DRY FROM
TUESDAY NIGHT THROUGH FRIDAY.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NYZ072>075-176-
178.
NJ...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NJZ004-006-
103>108.
MARINE...NONE.
&&
$$
SYNOPSIS...JMC/MET
NEAR TERM...DS
SHORT TERM...JMC
LONG TERM...MET
AVIATION...GC
MARINE...JMC/MET
HYDROLOGY...JMC/MET
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1234 PM EDT MON JUL 20 2015
.SYNOPSIS...
A SURFACE TROUGH WILL SET UP OVER THE AREA TODAY. A COLD FRONT
WILL APPROACH ON TUESDAY...AND MOVE THROUGH TUESDAY EVENING. HIGH
PRESSURE WILL THEN BUILD IN FROM WEDNESDAY THROUGH FRIDAY...MOVING
OFF THE COAST SATURDAY. A WEAK COLD FRONT APPROACHES SATURDAY
NIGHT AND SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
TEMPERATURES CONTINUE TO WARM INTO THE LOWER AND MIDDLE 90S. THE
WARMEST LOCATIONS ACROSS THE CWA AT NOON ARE ACROSS LONG ISLAND.
THE ISLIP MACARTHUR AIRPORT HAS REACHED 92 DEGREES AS OF
NOON...WHICH IS THE FIRST TIME SINCE JULY 20TH 2013 THAT THE
TEMPS HAS REACHED 90 OR HIGHER AT THIS LOCATION. TEMPS ARE IN THE
UPPER 80S AND LOWER 90S ELSEWHERE. HEAT INDICES ARE HIGHEST ACROSS
LONG ISLAND AND COASTAL CONNECTICUT...IN THE MIDDLE AND UPPER 90S.
DEW POINTS ARE IN THE MIDDLE 60S ACROSS THE NYC AND NJ METRO SO
HEAT INDICES ARE IN THE LOWER TO MIDDLE 90S.
HAVE ADJUSTED HOURLY TEMPS TO BETTER REFLECT THE LATEST
OBSERVATIONAL TRENDS. THIS CONTINUES TO GIVE HIGHS IN THE LOWER TO
MIDDLE 90S. MAX HEAT INDICES WILL BE IN THE UPPER 90S FOR THE NYC
METRO AND NEAR 100 ACROSS NE NJ.
SURFACE TROUGH IS BEGINNING TO REDEVELOP ACROSS THE NYC METRO. SEA
BREEZES HAVE ALSO DEVELOPS ACROSS THE SOUTH SHORE OF LONG ISLAND
AND COASTAL CT. THESE SEA BREEZES WILL SLOWLY MOVE INLAND THROUGH
THE AFTERNOON. THE LATEST RAP AND HRRR MODELS CONTINUE TO BRING
THIS BOUNDARY THROUGH THE NYC METRO LATE THIS AFTERNOON. IT IS
POSSIBLE THIS IS OVERDONE. HOWEVER...IF IT DOES MOVE THROUGH...DEW
POINTS COULD BOUNCE BACK UP INTO THE LOWER 70S.
SO FAR...NO CONVECTION HAS DEVELOPED ON THE SEA BREEZE
CONVERGENCE. STILL FEEL THAT THIS CONVERGENCE IS THE ONLY FOCUS
FOR ANY CONVECTIVE DEVELOPMENT. INSTABILITY IS VERY HIGH...2000 TO
3000 J/KG TODAY. ANY STRONGER CELL COULD PRODUCE STRONG WIND GUSTS
WITH INVERTED V SOUNDINGS INDICATED BY BUFKIT.
&&
.SHORT TERM /TUESDAY/...
A COLD FRONT CURRENTLY OVER THE NRN PLAINS WILL APPROACH...BUT THE
FEATURE APPEARS TO HAVE SLOWED SOMEWHAT FROM PREVIOUS PROGS. THIS
COULD RESULT IN A COMPLETELY DRY DAY ACROSS THE CWA. HAVE TRIMMED
BACK POPS TO SCHC AS A RESULT...KEEPING IN MIND THAT THERE MAY BE
SOME RESIDUAL BOUNDARIES IN THE AREA. HOT TEMPS BUT THE HX ATTM
BLW 95 IN THE CITY. THE ADVY WAS THEREFORE NOT EXTENDED. TEMPS DO
HAVE A TENDENCY TO RISE HIGHER THAN MODEL GUIDANCE AHEAD OF A
COLD FRONT...SO THIS WILL NEED TO BE WATCHED.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
BROAD UPPER TROUGH AND ASSOCIATED CLOSED LOW ACROSS EASTERN CANADA
MOVES SLOWLY EAST TUESDAY INTO TUESDAY NIGHT. A WEAK SHORTWAVE
ROTATES THROUGH THE TROUGH AND EAST OF THE REGION BY LATER TUESDAY
NIGHT. THE SHORTWAVE WILL BE ACCOMPANIED BY A WEAK COLD FRONT.
SCATTERED CONVECTION WILL BE POSSIBLE WITH THE FRONT. TIMING OF THE
COLD FRONT IS CONSISTENT AMONG THE GUIDANCE. HOWEVER...GUIDANCE
BRINGS THE FRONT THROUGH MAINLY DRY TUESDAY EVENING. WILL HAVE JUST
SLIGHT CHANCE POPS AT THIS TIME.
HIGH PRESSURE BUILDS IN SLOWLY FROM THE WEST TUESDAY NIGHT INTO
SATURDAY WITH A HIGHLY AMPLIFIES UPPER FLOW AS A RIDGE BUILDS INTO
THE CENTRAL UNITED STATES AND CANADA WITH A PACIFIC NORTHWEST
TROUGH AND THE EASTERN CANADIAN TROUGH.
THE UPPER RIDGE WEAKENS BY THE WEEKEND WITH THE UPPER TROUGH
SHIFTING OFF THE CANADIAN MARITIME AND NORTHEAST COAST. THIS ALLOWS
A NORTHERN STREAM SHORTWAVE TO MOVE NORTH OF THE REGION SATURDAY
NIGHT INTO SUNDAY. A WEAKENING COLD FRONT MOVES SLOWLY INTO THE AREA
FOR SUNDAY. NEXT CHANCE OF PRECIPITATION WILL BE SUNDAY NIGHT INTO
NEXT MONDAY AND WILL HAVE LOW CHANCE POPS AT THIS TIME.
&&
.AVIATION /16Z MONDAY THROUGH FRIDAY/...
A TROUGH OF LOW PRESSURE WILL REMAIN ACROSS THE AREA THROUGH EARLY
TONIGHT. A COLD FRONT WILL APPROACH ON TUESDAY...AND MOVE THROUGH
TUESDAY EVENING.
PREVAILING WEATHER WILL BE VFR. TEMPO MVFR IN CIGS AND VSBY POSSIBLE
IN AFTN AND EVE ISOLATED TO SCT TSTMS EACH DAY. CONFIDENCE IS TOO
LOW TO INCLUDE IN TAFS.
WINDS...TIMING THE DEVELOPMENT AND WESTWARD EXTENT OF SEA BREEZES
ACROSS THE METRO AREA REMAINS UNCERTAIN. HIGHEST CONFIDENCE IS
FROM KJFK AND KLGA EAST WITH SEA BREEZES DEVELOPING 16Z-18Z AT
ARND 10 KT. SEA BREEZES MIGHT NOT REACH KEWR / KTEB AND KHPN.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT:
HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: AMENDMENTS POSSIBLE WITH LATER DEVELOPMENT
OF SEABREEZE. ISOLATED TSTM POSSIBLE 18Z-00Z.
KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE WITH LATER DEVELOPMENT
OF SEABREEZE. ISOLATED TSTM POSSIBLE 18Z-00Z.
KEWR FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR SEABREEZE WIND
SHIFT. ISOLATED TSTM POSSIBLE 18Z-00Z.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE WITH SEABREEZE WIND
SHIFT. ISOLATED TSTM POSSIBLE 18Z-00Z.
KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE WITH LOW CHC OF
SEABREEZE. ISOLATED TSTM POSSIBLE 18Z-00Z.
KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE WITH LATER DEVELOPMENT
OF SEABREEZE. ISOLATED TSTM POSSIBLE 18Z-00Z.
.OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY...
.MONDAY NIGHT-TUESDAY NIGHT...VFR. ISOLD-SCT SHRA/TSRA WITH
LOCALLY MVFR CONDITIONS POSSIBLE...HOWEVER MOST PLACES MORE LIKELY
TO NOT EXPERIENCE THAN TO EXPERIENCE ANY CONVECTION.
.WEDNESDAY-THURSDAY...VFR. NW WINDS G15-20KT POSSIBLE.
.THURSDAY NIGHT-FRIDAY...VFR.
&&
.MARINE...
NO CHANGES AT THIS TIME.
DUE TO A WEAK PRES GRAD OVER THE WATERS...WINDS AND SEAS BLW SCA
LVLS THRU TUE. A COLD FRONT MOVES ACROSS THE FORECAST WATERS
TUESDAY EVENING. HIGH PRESSURE BUILDS SLOWLY EAST TUESDAY NIGHT
THROUGH THURSDAY AND MOVES OVER THE WATERS FRIDAY. WIND AND SEAS
REMAIN BELOW SMALL CRAFT LEVELS TUESDAY NIGHT THROUGH FRIDAY.
&&
.HYDROLOGY...
ANY TSTMS THAT DEVELOP TODAY WILL BE SLOW MOVING. AS A
RESULT...THERE IS AN ISOLD FLASH FLOOD THREAT. NO SIGNIFICANT
PRECIPITATION EXPECTED TUESDAY AND TUESDAY EVENING. DRY FROM
TUESDAY NIGHT THROUGH FRIDAY.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NYZ072>075-176-
178.
NJ...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NJZ004-006-
103>108.
MARINE...NONE.
&&
$$
SYNOPSIS...JMC/MET
NEAR TERM...DS
SHORT TERM...JMC
LONG TERM...MET
AVIATION...GC
MARINE...JMC/MET
HYDROLOGY...JMC/MET
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
342 PM EDT MON JUL 20 2015
...NUMEROUS SHOWERS AND THUNDERSTORMS EXPECTED EACH DAY THIS WEEK
WITH LOCALLY HEAVY RAINFALL AND FREQUENT LIGHTNING POSSIBLE...
.NEAR TERM /TONIGHT THROUGH TUESDAY/...THE SHORT RANGE PATTERN
REMAINS STATIC WITH A MEAN UPPER LEVEL TROUGH ALONG THE EAST
COAST...STRONG UPPER LEVEL HIGH PRESSURE OVER THE THE LOWER
MISSISSIPPI RIVER VALLEY AND TEXAS...A SURFACE RIDGE ALONG THE
FLORIDA EAST COAST AND TROUGHING OVER THE CONTINENTAL SOUTHEAST
STATES. WITH THE MEAN FLOW OUT OF THE WEST- SOUTHWEST THE EARLY
ACTIVITY ON TUESDAY SHOULD BE FROM THE GULF...THEN MOVING ACROSS
THE NATURE COAST AND THEN TOWARD SAINT AUGUSTINE AND THE FLORIDA
EAST COAST. LATER IN THE DAY OUR BARRAGE OF OUTFLOW BOUNDARIES AND
CONVECTION SHOULD CONTINUE TO DROP OUT OF CENTRAL GEORGIA AND
TOWARD SOUTHEAST GEORGIA/INTERSTATE-10. TEMPERATURES ACROSS
INTERIOR SOUTHEAST GEORGIA AND THE SUWANNEE VALLEY SHOULD CONTINUE
IN THE MID TO UPPER 90S AND EVEN FLIRTING WITH THE CENTURY MARK IN
A FEW PLACES. WITH EARLIER CONVECTION AND HIGHER HUMIDITY SOUTH OF
INTERSTATE 10 TEMPS WILL BE IN THE LOWER TO MID 90S WITH SCATTERED
TO NUMEROUS THUNDERSTORMS.
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...SFC TROUGH
CONTINUES TO MOVE SOUTHWARD DOWN THE ATLANTIC COAST THROUGH
WEDNESDAY NIGHT WHEN IT CLOSES OFF OVER SC AND ASSOCIATED FRONTAL
BOUNDARY BECOMES STATIONARY ACROSS NORTHERN GA/AL. UNSTABLE
SOUTHWESTERLY FLOW WILL INTERACT WITH SFC TROUGH BOTH DAYS
ALLOWING AN EARLY START TO SHOWERS AND TSTORMS EACH MORNING NEAR
THE GOMEX THEN SPREADING AREA WIDE...PEAKING IN COVERAGE DURING
THE MID AFTERNOON HOURS. AS THE INTENSITY OF STORMS INCREASES EACH
DAY AND FORECAST SOUNDINGS CONTINUE TO SHOW PWATS OF AROUND 2.00
TO 2.25 INCHES HEAVY RAINFALL COULD BE A POTENTIAL CONCERN FOR
WEDS AND THURS AFTERNOONS. ACTIVITY WILL WEAKEN AFTER SUNSET EACH
DAY AND REMAIN ISOLATED DURING THE OVERNIGHT HOURS. HEAT INDICES
STILL A CONCERN WEDS AND THURS AFTERNOONS REACHING 102-107 DEGREES
AS DEWPOINTS DO NOT WAVER FROM THE MID 70S.
.LONG TERM /FRIDAY THROUGH SUNDAY NIGHT/...WET PATTERN PERSISTS INTO
THE FIRST PART OF THE WEEKEND AS SFC TROUGH AND ASSOCIATED FRONTAL
BOUNDARY CONTINUE TO MOVE TOWARDS THE LOCAL AREA AND MID LEVEL
RIDGE STRENGTHENS OVER THE CENTRAL US. SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS ARE EXPECTED AREA WIDE ON FRIDAY
AFTERNOON AHEAD OF THE FRONTAL BOUNDARY...BEGINNING EARLY IN THE
DAY NEAR THE GOMEX AND SUWANNEE VALLEY THEN INCREASING IN COVERAGE
THROUGHOUT THE AFTERNOON. LOW WILL CENTER OVER THE AREA ON
SATURDAY CONTINUING ITS SOUTHWARD PROGRESSION AS HIGH PRESSURE
BRIEFLY BUILDS IN OVER SOUTHEAST GA ON SATURDAY NIGHT AND SUNDAY.
SATURDAY WILL SEE HIGHEST CHANCES FOR CONVECTION FOCUSED ACROSS NE
FL AS BOUNDARY WILL BE PRESENT NEAR THE FL/GA BORDER AND HIGHEST
LEVELS OF MOISTURE REMAIN LOCATED TO ITS SOUTH. BY SUNDAY PATTERN
BEGINS TO CHANGE AS BOUNDARY PUSHES SOUTHWARD AND DRIER AIR MASS
MOVES OVER SE GA. PRECIP CHANCES WILL BE HIGHEST IN OUR SOUTHERN
ZONES IN NORTH CENTRAL FL WITH ONLY WIDELY SCATTERED ACTIVITY
EXPECTED OVER SE GA. TEMPS WILL REMAIN NEAR NORMAL WITH MAXS IN
THE UPPER 80S/LOW 90S AND LOWS IN THE LOW/MID 70S THROUGHOUT THE
LONG TERM.
&&
.AVIATION...
WILL CONTINUE TO KEEP TEMPOS IN FOR ALL OF THE FLORIDA FIELDS
WITH CEILINGS ABOUT 3 KFT IN THUNDERSTORMS THROUGH THIS EVENING.
WITH WITH MORE SUBSIDENCE IN EVIDENCE OVER GEORGIA WILL KEEP
CONVECTION AS VICINITY FOR SAINT SIMONS ISLAND BUT THAT MAY NEED
TO BE AMENDED IF CONVECTION POPS AS THE HRRR MODEL IS ADVERTISING.
TUESDAY...LOOK FOR A PATTERN VERY SIMILAR TO TODAY WITH EARLY
STORMS OVER THE FIELDS SOUTH OF INTERSTATE 10 AND LATER ACTIVITY
NORTH OF THERE.
&&
.MARINE...
WINDS WITH TONIGHTS NOCTURNAL SOUTHWESTERLY SURGE LOOK LIKE THEY
WILL REACH SCEC CRITERIA OVER THE OFFSHORE WATERS WHICH SHOULD CONTINUE
INTO TUESDAY. OTHERWISE...LOOK FOR CONVECTION TO DROP OFF DURING
THE EARLY EVENING HOURS TONIGHT AND THEN A REPEAT OF EARLY
CONVECTION MOVING OFF THE ATLANTIC COAST TOMORROW AFTERNOON IS
EXPECTED.
RIP CURRENTS: LOW RISK.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 76 94 76 95 / 40 50 30 50
SSI 79 90 79 91 / 40 40 20 40
JAX 76 93 78 94 / 50 50 20 50
SGJ 77 90 77 91 / 50 50 20 40
GNV 74 91 76 91 / 60 60 20 60
OCF 74 90 75 90 / 60 60 20 60
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
GUILLET/SANDRIK/SHASHY
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
155 PM EDT MON JUL 20 2015
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL DOMINATE THROUGH MID WEEK WITH AN
UPPER LEVEL DISTURBANCE APPROACHING THE SOUTHEAST US WEDNESDAY.
ABOVE NORMAL TEMPERATURES EARLY IN THE PERIOD WITH A SLIGHT COOLING
TREND BY THE END OF THE WEEK. SCATTERED DIURNAL THUNDERSTORMS EACH
DAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE SURFACE PRESSURE TROUGH WILL REMAIN IN THE FORECAST AREA
THROUGH TONIGHT. ALOFT...THE AREA WILL BE ON THE EASTERN PERIPHERY
OF THE SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY RIDGE. THE
MODELS AND WATER VAPOR IMAGERY TRENDS INDICATE ANOTHER IN A SERIES
OF MID-LEVEL SHORTWAVE TROUGHS WILL AFFECT THE AREA. THUNDERSTORM
COVERAGE MAY BE LIMITED BY THE UPPER RIDGING AND SLOW STORM
MOVEMENT AS INDICATED BY DIFLUENT HEIGHTS. THE HRRR AND ARW
DISPLAY ISOLATED TO SCATTERED COVERAGE TODAY. THE SPC WRF
INDICATED CONSIDERABLE COVERAGE THIS EVENING. WE LEANED TOWARD THE
HIGHER GUIDANCE POPS BASED ON THE PATTERN WITH THE GREATEST CHANCE
LATE THIS AFTERNOON INTO THE EVENING. THE NAM HAS SURFACE-BASED
LI/S -6 TO -8 TODAY. MODERATE INSTABILITY WITH AN INVERTED-V
SOUNDING INDICATES DAMAGING WIND MAY OCCUR WITH A FEW OF THE
THUNDERSTORMS. A SLOW STORM MOVEMENT AND PRECIPITABLE WATER NEAR 2
INCHES ALSO INDICATES A POSSIBILITY OF LOCALIZED FLOODING. THE
RECENT BIAS SUPPORTS THE HIGHER TEMPERATURE GUIDANCE. IT WILL BE
ANOTHER HOT DAY WITH HIGHS AROUND 100.
THUNDERSTORM COVERAGE SHOULD DIMINISH OVERNIGHT WITH THE LOSS OF
HEATING AND PREVIOUS CONVECTION ALTHOUGH ANOTHER IN A SERIES OF
MID-LEVEL SHORTWAVE TROUGHS SUPPORTS A CONTINUED CHANCE LATE. USED
THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
SURFACE TROUGH HANGS IN OVER THE FORECAST AREA AHEAD OF AN
APPROACHING COLD FRONT THOUGH WEDNESDAY. FAIRLY ACTIVE PATTERN
WITH SERIES OF MOSTLY WEAK SHORTWAVES MOVING NEAR THE AREA IN A
WESTERLY FLOW ALOFT...A MORE PRONOUNCED SHORTWAVE WILL PUSH
ACROSS THE REGION LATE WEDNESDAY. SPC CURRENTLY HAS US IN GENERAL
THUNDER BUT COULD HAVE A FEW STRONGER STROMS ALONG COLD FRONT. MAY
NEED A HEAT ADVISORY FOR SOUTHERN HALF OF CWA TUESDAY AFTERNOON
18-22Z OR SO...ENDED UP HAVING TO ISSUE ONE THIS AFTERNOON FOR
AREAS SOUTH. DEWPOINTS IN LOWER 70S AND TEMPS AROUND 100 WILL
BRING APPARENT TEMPS UP TO NEAR ADVISORY CRITERIA. GUIDANCE
CONSENSUS FOR THE TEMPERATURE FORECAST SEEMS REASONABLE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
EXTENDED GUIDANCE KEEPS UPPER RIDGE OVER CENTRAL US WITH TROUGH
OVER THE NE US. WEAK SHORTWAVES IN THE WEST TO NORTHWEST FLOW
ALOFT WILL PROVIDE A TRIGGER FOR MAINLY SCATTERED CONVECTION.
BEST CHANCE WHEN TRIGGER COINCIDES WITH BEST DIURNAL HEATING.
TEMPERATURES LOWERING TO NEAR CLIMATOLOGY...LOWER TO MID 90S...BY
THE WEEKEND. 20 TO 40 PERCENT POPS THROUGH THE PERIOD.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
VFR CONDITIONS EXPECTED OUTSIDE OF AFTERNOON/EVENING THUNDERSTORMS.
A SURFACE TROUGH OVER THE REGION AND APPROACHING SHORTWAVE ENERGY
WILL PROMOTE SCATTERED DIURNAL CONVECTION MAINLY DURING THE LATE
AFTERNOON AND EVENING HOURS. DAMAGING WINDS ARE THE MAIN THREAT
WITH THESE STORMS. MODELS INDICATE POTENTIAL FOR BRIEF MVFR FOG
EARLY TUESDAY MORNING...ALTHOUGH A 25 TO 30 KNOT LOW LEVEL JET
SHOULD LIMIT DEVELOPMENT. FOG POTENTIAL AT THE TAF SITES MAY ALSO
DEPEND ON WHICH SITES RECEIVE RAIN TODAY. WINDS WILL BE OUT OF THE
SOUTHWEST AT AROUND 8 KNOTS THIS AFTERNOON BECOMING LIGHT AND
VARIABLE AFTER SUNSET.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS EXPECTED IN DIURNAL
CONVECTION TUESDAY THROUGH FRIDAY. AREAS OF MVFR VSBYS POSSIBLE
DURING THE EARLY MORNING EACH DAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR SCZ018-025-030-
035>038-041.
GA...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR GAZ040-063>065-
077.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
140 PM EDT MON JUL 20 2015
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL DOMINATE THROUGH MID WEEK WITH AN
UPPER LEVEL DISTURBANCE APPROACHING THE SOUTHEAST US WEDNESDAY.
ABOVE NORMAL TEMPERATURES EARLY IN THE PERIOD WITH A SLIGHT COOLING
TREND BY THE END OF THE WEEK. SCATTERED DIURNAL THUNDERSTORMS EACH
DAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE SURFACE PRESSURE TROUGH WILL REMAIN IN THE FORECAST AREA
THROUGH TONIGHT. ALOFT...THE AREA WILL BE ON THE EASTERN PERIPHERY
OF THE SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY RIDGE. THE
MODELS AND WATER VAPOR IMAGERY TRENDS INDICATE ANOTHER IN A SERIES
OF MID-LEVEL SHORTWAVE TROUGHS WILL AFFECT THE AREA. THUNDERSTORM
COVERAGE MAY BE LIMITED BY THE UPPER RIDGING AND SLOW STORM
MOVEMENT AS INDICATED BY DIFLUENT HEIGHTS. THE HRRR AND ARW
DISPLAY ISOLATED TO SCATTERED COVERAGE TODAY. THE SPC WRF
INDICATED CONSIDERABLE COVERAGE THIS EVENING. WE LEANED TOWARD THE
HIGHER GUIDANCE POPS BASED ON THE PATTERN WITH THE GREATEST CHANCE
LATE THIS AFTERNOON INTO THE EVENING. THE NAM HAS SURFACE-BASED
LI/S -6 TO -8 TODAY. MODERATE INSTABILITY WITH AN INVERTED-V
SOUNDING INDICATES DAMAGING WIND MAY OCCUR WITH A FEW OF THE
THUNDERSTORMS. A SLOW STORM MOVEMENT AND PRECIPITABLE WATER NEAR 2
INCHES ALSO INDICATES A POSSIBILITY OF LOCALIZED FLOODING. THE
RECENT BIAS SUPPORTS THE HIGHER TEMPERATURE GUIDANCE. IT WILL BE
ANOTHER HOT DAY WITH HIGHS AROUND 100.
THUNDERSTORM COVERAGE SHOULD DIMINISH OVERNIGHT WITH THE LOSS OF
HEATING AND PREVIOUS CONVECTION ALTHOUGH ANOTHER IN A SERIES OF
MID-LEVEL SHORTWAVE TROUGHS SUPPORTS A CONTINUED CHANCE LATE. USED
THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
SURFACE TROUGH HANGS IN OVER THE FORECAST AREA AHEAD OF AN
APPROACHING COLD FRONT THOUGH WEDNESDAY. FAIRLY ACTIVE PATTERN
WITH SERIES OF MOSTLY WEAK SHORTWAVES MOVING NEAR THE AREA IN A
WESTERLY FLOW ALOFT...A MORE PRONOUCED SHORTWAVE WILL PUSH ACROSS
THE REGION LATE WEDNESDAY. SPC CURRENTLY HAS US IN GENERAL THUNDER
BUT COULD HAVE A FEW STRONGER STROMS ALONG COLD FRONT. MAY NEED A
HEAT ADVISORY FOR SOUTHERN HALF OF CWA TUESDAY AFTERNOON 18-22Z OR
SO...ENDED UP HAVING TO ISSUE ONE THIS AFTERNOON FOR AREAS SOUTH.
DEWPOINTS IN LOWER 70S AND TEMPS AROUND 100 WILL BRING APPARENT
TEMPS UP TO NEAR ADVISORY CRITERIA. GUIDANCE CONSENSUS FOR THE
TEMPERATURE FORECAST SEEMS REASONABLE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
EXTENDED GUIDANCE KEEPS UPPER RIDGE OVER CENTRAL US WITH TROUGH
OVER THE NE US. WEAK SHORTWAVES IN THE WEST TO NORTHWEST FLOW
ALOFT WILL PROVIDE A TRIGGER FOR MAINLY SCATTERED CONVECTION.
BEST CHANCE WHEN TRIGGER COINCIDES WITH BEST DIURNAL HEATING.
TEMPERATURES LOWERING TO NEAR CLIMATOLOGY...LOWER TO MID 90S...BY
THE WEEKEND. 20 TO 40 PERCENT POPS THROUGH THE PERIOD.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
VFR CONDITIONS EXPECTED OUTSIDE OF DIURNAL THUNDERSTORMS AND EARLY
MORNING FOG.
LIGHT WEST WINDS DURING THE MORNING BECOMING SOUTHWEST 8-10 KNOTS
THIS AFTERNOON. SCATTERED DIURNAL CONVECTION TO DEVELOP AFTER 18Z
AND CONTINUING INTO THE EARLY EVENING. MODELS INDICATE POTENTIAL
FOR FOG EARLY TUESDAY MORNING...ALTHOUGH A 25 TO 30 KNOT NOCTURNAL
JET SHOULD LIMIT DEVELOPMENT. FOG POTENTIAL MAY ALSO DEPEND ON
WHICH SITES RECEIVE RAIN TODAY.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS EXPECTED IN DIURNAL
CONVECTION TUESDAY THROUGH FRIDAY. AREAS OF MVFR VSBYS POSSIBLE
DURING THE EARLY MORNING EACH DAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR SCZ018-025-030-
035>038-041.
GA...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR GAZ040-063>065-
077.
&&
$$
87
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
514 PM CDT MON JUL 20 2015
.SHORT TERM...
230 PM CDT
THROUGH TONIGHT...
A SHORT WAVE TROUGH AXIS ORIENTED FROM SOUTHWEST WISCONSIN THROUGH
FAR WESTERN ILLINOIS AS OF 230 PM WILL MOVE OVER THE FORECAST
AREA LATE THIS AFTERNOON. A PATCH OF CLEARING HAS ALLOWED
TEMPERATURES TO REACH MID 80S WITH A FEW UPPER 80S ATTAINED IN
EASTERN AREAS. THESE ARE AT CONVECTIVE VALUES GIVEN THE DEW POINTS
AND ACCORDINGLY SOME CUMULUS...A FEW TOWERING...HAVE DEVELOPED IN
THE AREA. LAPSE RATES ABOVE THE LFC REMAIN NON-IMPRESSIVE PER
AMDAR AND RAP ANALYSIS SO WHILE SOME SHOWERS MAY DEVELOP/INCREASE
IN COVERAGE WITH THIS IMPULSE AS IT MOVES EAST...THUNDER MAY STILL
BE HARD TO COME BY.
A SURFACE COLD FRONT EXTENDING FROM A LOW AT THE SOUTHERN TIP OF
JAMES BAY IN CANADA WILL MOVE SOUTHEAST THROUGH THE AREA THIS
EVENING...BASICALLY RIGHT IN THE WAKE OF THE AFOREMENTIONED SHORT
WAVE TROUGH. THE AIR MASS AHEAD OF THE FRONT IN WISCONSIN TO
EASTERN IOWA HAS STRUGGLED TO DESTABILIZE GIVEN CLOUD COVER...BUT
A FEW STORMS ARE STARTING TO POP AS THAT MOVES EAST. SCATTERED
SHOWERS AND A FEW STORMS SHOULD DEVELOP IMMEDIATELY UPSTREAM AND
SOME ARE ANTICIPATED TO PROGRESS INTO THE CWA BETWEEN 6 AND 9 PM.
COVERAGE SHOULD REMAIN SCATTERED. AS NOTED EARLIER...THE SOMEWHAT
LIMITED INSTABILITY SHOULD KEEP COVERAGE 30-50 PERCENT ALONG THE
BOUNDARY. WHILE SOME 35 MPH PLUS GUSTS MAY ACCOMPANY A FEW STORMS
GIVEN MARGINAL EFFECTIVE DEEP LAYER SHEAR AND 700-1000 J/KG OF
DCAPE...THE ATMOSPHERE REMAINS NON-CONDUCIVE FOR SEVERE STORMS.
THE FOCUS FOR SHOWERS SHOULD CLEAR THE CWA BY MIDNIGHT WITH
CLOUDS QUICKLY CLEARING AS WELL. A SECONDARY MOMENTUM PUSH OF THE
DRIER AIR MASS SHOULD ARRIVE LATE ON NORTHERLY WINDS...WITH LOW
TEMPERATURES BY DAYBREAK NEAR NORMAL.
MTF
&&
.LONG TERM...
328 PM CDT
TUESDAY THROUGH MONDAY...
NO SIGNIFICANT WEATHER CONCERNS FOR ONE OF THE FEW TIMES THIS
METEOROLOGICAL SUMMER. SURFACE HIGH PRESSURE REMAINING NEARLY
STATIONARY OVER THE REGION SHOULD KEEP THINGS DRY THROUGH
FRIDAY. EXPECTING DAILY LAKE BREEZE FORMATION THROUGH AT LEAST
THURSDAY. 12Z NAM DID HAVE A FEW PERIODS WITH CONVECTION FORECAST
TO POP ON LAKE BREEZE...WEDNESDAY EVENING AND THURSDAY
AFTERNOON...THOUGH DEWPOINTS SEEM TO BE HIGH BIASED EVEN WITH VERY
WET SUMMER SO FAR. THUS THINKING IS INSTABILITY WILL REMAIN
MINIMAL EVEN WITH A FEW UPPER DISTURBANCES MOVING OVER THE AREA
LATE WEDNESDAY AND AGAIN ON THURSDAY...COUPLING WITH DRY COLUMN TO
ENABLE DRY CONDITIONS TO PREVAIL. CANNOT COMPLETELY RULE OUT A
FEW ISOLATED SHOWERS BEING SQUEEZED OUT ON THURSDAY GIVEN STRONGER
VORT MAX.
TEMPERATURES ON TUESDAY SHOULD REACH AROUND 80 INLAND
BASED ON 925 MB TEMPS IN THE UPPER TEENS CELSIUS AND FAIRLY DEEP
MIXING. THEN EXPECT GRADUAL WARMING THE REST OF THE WEEK INTO THE
WEEKEND DUE TO RISING HEIGHTS FROM SOUTHERN CONUS MID/UPPER RIDGE.
GUIDANCE HAS OFTEN VERIFIED TOO HIGH THIS SUMMER WITH TEMPS...BUT
WONDER IF PROGGED THERMAL PROFILES MAY BE SUPPORTIVE OF A BIT
WARMER THAN FORECAST LOWER 80S ON WEDNESDAY AND THURSDAY AND LOWER
TO MID 80S ON FRIDAY SINCE THERE WILL LIKELY NOT BE CONVECTIVE
DEBRIS CLOUD COVER TO CONTEND WITH. DOES APPEAR A BIT BETTER
CHANCE FOR MID AND HIGH CLOUDS ON THURSDAY THOUGH AFTER A FEW TO
SCT CU ON WEDNESDAY. A COLD FRONT WILL APPROACH FROM THE NORTHWEST
ON FRIDAY NIGHT AND THEN MOVE ACROSS THE AREA ON
SATURDAY...BRINGING A THREAT FOR SHOWERS AND THUNDERSTORMS.
THERE IS UNCERTAINTY ON TIMING...COVERAGE AND INTENSITY THIS FAR
OUT AND THEN WITH OVERALL PATTERN EVOLUTION BEYOND SATURDAY
EVENING FRONT. STILL APPEARS IT WILL GENERALLY BE LESS ACTIVE THAN
WHAT WE HAVE SEEN MUCH OF THIS SUMMER AND SEASONABLY WARM.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* CHANCE OF SHRA/ISOLATED TSRA...MAINLY EARLY EVENING.
* NE WINDS ABOVE 10 KT LATE TONIGHT INTO EARLY TUESDAY.
MDB
//DISCUSSION...UPDATED 22Z...
UPPER LEVEL SHORTWAVE CONTINUES TO DRIVE SHRA/TSRA SOUTH OF THE
TERMINALS GENERALLY SOUTH OF A LINE FROM KC09 TO KIGQ WITH SOME
SPOTTY SPRINKLES/LIGHT RAIN TO THE NORTH. NOT EXPECTING THIS AREA
OF SHRA/TSRA TO EXPAND NORTHWARD MUCH OF AT ALL. SCATTERED
SHRA/TSRA HAS DEVELOPED ALONG OR JUST BEHIND AN APPROACHING COOL
FRONT ACROSS CENTRAL AND SOUTHWEST WISCONSIN. RADAR TRENDS SUPPORT
THIS ACTIVITY MOVING ACROSS THE TERMINALS EARLY THIS EVENING BUT
IT MAY HAVE A DIFFICULT TIME HOLDING TOGETHER WITH TIME AS IT WILL
BE MOVING INTO AN AREA THAT HAS HAD FAIRLY EXTENSIVE CLOUD COVER
MOST OF THE DAY. WILL MAINTAIN TEMPO SHRA MENTION BUT SLOW THE
TIMING SLIGHTLY. COULD SEE SOME ISOLATED THUNDER BUT THE POTENTIAL
IS TOO LOW TO MENTION IN THE TAF.
MDB
FROM 18Z...
CURRENT SHOWER ACTIVITY PUSHING THROUGH SOUTHERN WISCONSIN AND
CROSSING THE MISSISSIPPI RIVER INTO ILLINOIS IS TIED TO A POTENT
UPPER LEVEL SHORT WAVE IN IOWA. THIS ACTIVITY IS OUT AHEAD OF A
COLD FRONT SLATED TO COME THROUGH NORTHEAST ILLINOIS LATER THIS
EVENING. UPSTREAM OBSERVATIONS ARE IN A SLIGHTLY MORE MOIST
ENVIRONMENT AND HAVE BEEN ABLE TO SATURATE THE LOWER LEVELS TO
SUPPORT SOME RAIN. DEWPOINTS OVER NORTHEAST ILLINOIS ARE LOWER
THAN THESE AREAS...THEREFORE IN SPITE OF THE WAVE TRACKING RIGHT
THROUGH THE AREA THIS AFTERNOON...SHOWER ACTIVITY...AND ESPECIALLY
ANY LIMITED THUNDER POTENTIAL...WILL STRUGGLE INITIALLY. THERE IS
SOME CUMULUS DEVELOPMENT AHEAD OF THIS WAVE AS WELL. HAVE
INTRODUCED VCSH FOR THE TAFS FOR LATER THIS AFTERNOON TO ACCOUNT
FOR THIS PERIOD...BUT OVERALL IMPACTS SHOULD BE MINIMAL.
AFTER THE WAVE GOES PAST...IT APPEARS THE SLIGHTLY BETTER CHANCE
FOR SCATTERED SHOWER/ISOLATED THUNDER DEVELOPMENT WILL BE TIED TO
THE COLD FRONT...WHICH TRAILS THE UPPER LEVEL FORCING. WHILE
COVERAGE IS STILL IN QUESTION...BEST TIMING OF ACTIVITY WILL BE
JUST AHEAD OF THE FRONT IN THE 0-3Z TIME FRAME...WITH A SHIFT TO
NW WINDS 4-6Z. CURRENT TAFS PEG THE 0-2Z TIME FRAME AT THE
CHICAGO TERMINALS...COULD BE 1-3Z PER SOME CONVECTIVE ALLOWING
MODELS. A FLOP OVER TO NE WINDS IS EXPECTED OVERNIGHT WITH AN
INCREASE IN SPEEDS ABOVE 11 KT POSSIBLY INTO THE MORNING RUSH.
WINDS BACK TO NNW LATER TUESDAY....THOUGH THEY HANG ON NE CLOSER
TO THE LAKE.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM-HIGH IN TIMING OF SHRA POTENTIAL. MEDIUM-HIGH CONFIDENCE
THAT TSRA POTENTIAL AT THE TERMINALS IS LOW BUT MEDIUM IN SHRA
OCCURRENCE.
* MEDIUM-HIGH ON WIND SPEEDS AND TRENDS.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT THROUGH FRIDAY...VFR. WX NIL.
SATURDAY...CHANCE TSRA THROUGH THE EVENING. OTRW...VFR.
SUNDAY...VFR. WX NIL.
KREIN
&&
.MARINE...
230 PM CDT
A COLD FRONT WILL MOVE SOUTHWARD ACROSS THE LAKE THIS EVENING
TURNING WINDS NORTH AND EVEN BRIEFLY NORTH-NORTHEAST. THERE IS
LIKELY TO BE SCATTERED SHOWERS AND A FEW STORMS AHEAD OF THE FRONT
ACROSS THE SOUTHERN HALF OF THE LAKE THROUGH MID-EVENING. THE
NORTHERLY WINDS BEHIND THE FRONT ARE EXPECTED TO REACH 15 TO 20 KT
FOR A 3-4 HOUR OR SO PERIOD LATE TONIGHT INTO EARLY TUESDAY
MORNING WITH POSSIBLY A FEW HIGHER GUSTS. BECAUSE OF THE SHORT
DURATION OF THE HIGHER SPEEDS...THIS IS EXPECTED TO ONLY BUILD
WAVES TO 2 TO 4 FEET ACROSS THE ILLINOIS AND INDIANA NEARSHORES ON
TUESDAY MORNING. HIGH PRESSURE IS THEN EXPECTED TO MOVE OVER THE
LAKE FOR A QUIET MIDWEEK PERIOD.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
330 PM CDT MON JUL 20 2015
.SHORT TERM...
230 PM CDT
THROUGH TONIGHT...
A SHORT WAVE TROUGH AXIS ORIENTED FROM SOUTHWEST WISCONSIN THROUGH
FAR WESTERN ILLINOIS AS OF 230 PM WILL MOVE OVER THE FORECAST
AREA LATE THIS AFTERNOON. A PATCH OF CLEARING HAS ALLOWED
TEMPERATURES TO REACH MID 80S WITH A FEW UPPER 80S ATTAINED IN
EASTERN AREAS. THESE ARE AT CONVECTIVE VALUES GIVEN THE DEW POINTS
AND ACCORDINGLY SOME CUMULUS...A FEW TOWERING...HAVE DEVELOPED IN
THE AREA. LAPSE RATES ABOVE THE LFC REMAIN NON-IMPRESSIVE PER
AMDAR AND RAP ANALYSIS SO WHILE SOME SHOWERS MAY DEVELOP/INCREASE
IN COVERAGE WITH THIS IMPULSE AS IT MOVES EAST...THUNDER MAY STILL
BE HARD TO COME BY.
A SURFACE COLD FRONT EXTENDING FROM A LOW AT THE SOUTHERN TIP OF
JAMES BAY IN CANADA WILL MOVE SOUTHEAST THROUGH THE AREA THIS
EVENING...BASICALLY RIGHT IN THE WAKE OF THE AFOREMENTIONED SHORT
WAVE TROUGH. THE AIR MASS AHEAD OF THE FRONT IN WISCONSIN TO
EASTERN IOWA HAS STRUGGLED TO DESTABILIZE GIVEN CLOUD COVER...BUT
A FEW STORMS ARE STARTING TO POP AS THAT MOVES EAST. SCATTERED
SHOWERS AND A FEW STORMS SHOULD DEVELOP IMMEDIATELY UPSTREAM AND
SOME ARE ANTICIPATED TO PROGRESS INTO THE CWA BETWEEN 6 AND 9 PM.
COVERAGE SHOULD REMAIN SCATTERED. AS NOTED EARLIER...THE SOMEWHAT
LIMITED INSTABILITY SHOULD KEEP COVERAGE 30-50 PERCENT ALONG THE
BOUNDARY. WHILE SOME 35 MPH PLUS GUSTS MAY ACCOMPANY A FEW STORMS
GIVEN MARGINAL EFFECTIVE DEEP LAYER SHEAR AND 700-1000 J/KG OF
DCAPE...THE ATMOSPHERE REMAINS NON-CONDUCIVE FOR SEVERE STORMS.
THE FOCUS FOR SHOWERS SHOULD CLEAR THE CWA BY MIDNIGHT WITH
CLOUDS QUICKLY CLEARING AS WELL. A SECONDARY MOMENTUM PUSH OF THE
DRIER AIR MASS SHOULD ARRIVE LATE ON NORTHERLY WINDS...WITH LOW
TEMPERATURES BY DAYBREAK NEAR NORMAL.
MTF
&&
.LONG TERM...
328 PM CDT
TUESDAY THROUGH MONDAY...
NO SIGNIFICANT WEATHER CONCERNS FOR ONE OF THE FEW TIMES THIS
METEOROLOGICAL SUMMER. SURFACE HIGH PRESSURE REMAINING NEARLY
STATIONARY OVER THE REGION SHOULD KEEP THINGS DRY THROUGH
FRIDAY. EXPECTING DAILY LAKE BREEZE FORMATION THROUGH AT LEAST
THURSDAY. 12Z NAM DID HAVE A FEW PERIODS WITH CONVECTION FORECAST
TO POP ON LAKE BREEZE...WEDNESDAY EVENING AND THURSDAY
AFTERNOON...THOUGH DEWPOINTS SEEM TO BE HIGH BIASED EVEN WITH VERY
WET SUMMER SO FAR. THUS THINKING IS INSTABILITY WILL REMAIN
MINIMAL EVEN WITH A FEW UPPER DISTURBANCES MOVING OVER THE AREA
LATE WEDNESDAY AND AGAIN ON THURSDAY...COUPLING WITH DRY COLUMN TO
ENABLE DRY CONDITIONS TO PREVAIL. CANNOT COMPLETELY RULE OUT A
FEW ISOLATED SHOWERS BEING SQUEEZED OUT ON THURSDAY GIVEN STRONGER
VORT MAX.
TEMPERATURES ON TUESDAY SHOULD REACH AROUND 80 INLAND
BASED ON 925 MB TEMPS IN THE UPPER TEENS CELSIUS AND FAIRLY DEEP
MIXING. THEN EXPECT GRADUAL WARMING THE REST OF THE WEEK INTO THE
WEEKEND DUE TO RISING HEIGHTS FROM SOUTHERN CONUS MID/UPPER RIDGE.
GUIDANCE HAS OFTEN VERIFIED TOO HIGH THIS SUMMER WITH TEMPS...BUT
WONDER IF PROGGED THERMAL PROFILES MAY BE SUPPORTIVE OF A BIT
WARMER THAN FORECAST LOWER 80S ON WEDNESDAY AND THURSDAY AND LOWER
TO MID 80S ON FRIDAY SINCE THERE WILL LIKELY NOT BE CONVECTIVE
DEBRIS CLOUD COVER TO CONTEND WITH. DOES APPEAR A BIT BETTER
CHANCE FOR MID AND HIGH CLOUDS ON THURSDAY THOUGH AFTER A FEW TO
SCT CU ON WEDNESDAY. A COLD FRONT WILL APPROACH FROM THE NORTHWEST
ON FRIDAY NIGHT AND THEN MOVE ACROSS THE AREA ON
SATURDAY...BRINGING A THREAT FOR SHOWERS AND THUNDERSTORMS.
THERE IS UNCERTAINTY ON TIMING...COVERAGE AND INTENSITY THIS FAR
OUT AND THEN WITH OVERALL PATTERN EVOLUTION BEYOND SATURDAY
EVENING FRONT. STILL APPEARS IT WILL GENERALLY BE LESS ACTIVE THAN
WHAT WE HAVE SEEN MUCH OF THIS SUMMER AND SEASONABLY WARM.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* CHANCE OF SHRA/ISOLATED TSRA...MAINLY EARLY EVENING.
* NE WINDS ABOVE 10 KT LATE TONIGHT INTO EARLY TUESDAY.
KMD
//DISCUSSION...UPDATED 18Z...
CURRENT SHOWER ACTIVITY PUSHING THROUGH SOUTHERN WISCONSIN AND
CROSSING THE MISSISSIPPI RIVER INTO ILLINOIS IS TIED TO A POTENT
UPPER LEVEL SHORT WAVE IN IOWA. THIS ACTIVITY IS OUT AHEAD OF A
COLD FRONT SLATED TO COME THROUGH NORTHEAST ILLINOIS LATER THIS
EVENING. UPSTREAM OBSERVATIONS ARE IN A SLIGHTLY MORE MOIST
ENVIRONMENT AND HAVE BEEN ABLE TO SATURATE THE LOWER LEVELS TO
SUPPORT SOME RAIN. DEWPOINTS OVER NORTHEAST ILLINOIS ARE LOWER
THAN THESE AREAS...THEREFORE IN SPITE OF THE WAVE TRACKING RIGHT
THROUGH THE AREA THIS AFTERNOON...SHOWER ACTIVITY...AND ESPECIALLY
ANY LIMITED THUNDER POTENTIAL...WILL STRUGGLE INITIALLY. THERE IS
SOME CUMULUS DEVELOPMENT AHEAD OF THIS WAVE AS WELL. HAVE
INTRODUCED VCSH FOR THE TAFS FOR LATER THIS AFTERNOON TO ACCOUNT
FOR THIS PERIOD...BUT OVERALL IMPACTS SHOULD BE MINIMAL.
AFTER THE WAVE GOES PAST...IT APPEARS THE SLIGHTLY BETTER CHANCE
FOR SCATTERED SHOWER/ISOLATED THUNDER DEVELOPMENT WILL BE TIED TO
THE COLD FRONT...WHICH TRAILS THE UPPER LEVEL FORCING. WHILE
COVERAGE IS STILL IN QUESTION...BEST TIMING OF ACTIVITY WILL BE
JUST AHEAD OF THE FRONT IN THE 0-3Z TIME FRAME...WITH A SHIFT TO
NW WINDS 4-6Z. CURRENT TAFS PEG THE 0-2Z TIME FRAME AT THE
CHICAGO TERMINALS...COULD BE 1-3Z PER SOME CONVECTIVE ALLOWING
MODELS. A FLOP OVER TO NE WINDS IS EXPECTED OVERNIGHT WITH AN
INCREASE IN SPEEDS ABOVE 11 KT POSSIBLY INTO THE MORNING RUSH.
WINDS BACK TO NNW LATER TUESDAY....THOUGH THEY HANG ON NE CLOSER
TO THE LAKE.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM/HIGH IN TIMING IF ANY SHOWERS ARE TO OCCUR. LOW IN TSRA
DIRECTLY IMPACTING THE TERMINALS BUT MEDIUM IN SHRA.
* MEDIUM/HIGH ON WIND SPEEDS AND TRENDS.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT THROUGH FRIDAY...VFR. WX NIL.
SATURDAY...CHANCE TSRA THROUGH THE EVENING. OTRW...VFR.
SUNDAY...VFR. WX NIL.
KREIN
&&
.MARINE...
230 PM CDT
A COLD FRONT WILL MOVE SOUTHWARD ACROSS THE LAKE THIS EVENING
TURNING WINDS NORTH AND EVEN BRIEFLY NORTH-NORTHEAST. THERE IS
LIKELY TO BE SCATTERED SHOWERS AND A FEW STORMS AHEAD OF THE FRONT
ACROSS THE SOUTHERN HALF OF THE LAKE THROUGH MID-EVENING. THE
NORTHERLY WINDS BEHIND THE FRONT ARE EXPECTED TO REACH 15 TO 20 KT
FOR A 3-4 HOUR OR SO PERIOD LATE TONIGHT INTO EARLY TUESDAY
MORNING WITH POSSIBLY A FEW HIGHER GUSTS. BECAUSE OF THE SHORT
DURATION OF THE HIGHER SPEEDS...THIS IS EXPECTED TO ONLY BUILD
WAVES TO 2 TO 4 FEET ACROSS THE ILLINOIS AND INDIANA NEARSHORES ON
TUESDAY MORNING. HIGH PRESSURE IS THEN EXPECTED TO MOVE OVER THE
LAKE FOR A QUIET MIDWEEK PERIOD.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
239 PM CDT MON JUL 20 2015
.SHORT TERM...
230 PM CDT
THROUGH TONIGHT...
A SHORT WAVE TROUGH AXIS ORIENTED FROM SOUTHWEST WISCONSIN THROUGH
FAR WESTERN ILLINOIS AS OF 230 PM WILL MOVE OVER THE FORECAST
AREA LATE THIS AFTERNOON. A PATCH OF CLEARING HAS ALLOWED
TEMPERATURES TO REACH MID 80S WITH A FEW UPPER 80S ATTAINED IN
EASTERN AREAS. THESE ARE AT CONVECTIVE VALUES GIVEN THE DEW POINTS
AND ACCORDINGLY SOME CUMULUS...A FEW TOWERING...HAVE DEVELOPED IN
THE AREA. LAPSE RATES ABOVE THE LFC REMAIN NON-IMPRESSIVE PER
AMDAR AND RAP ANALYSIS SO WHILE SOME SHOWERS MAY DEVELOP/INCREASE
IN COVERAGE WITH THIS IMPULSE AS IT MOVES EAST...THUNDER MAY STILL
BE HARD TO COME BY.
A SURFACE COLD FRONT EXTENDING FROM A LOW AT THE SOUTHERN TIP OF
JAMES BAY IN CANADA WILL MOVE SOUTHEAST THROUGH THE AREA THIS
EVENING...BASICALLY RIGHT IN THE WAKE OF THE AFOREMENTIONED SHORT
WAVE TROUGH. THE AIR MASS AHEAD OF THE FRONT IN WISCONSIN TO
EASTERN IOWA HAS STRUGGLED TO DESTABILIZE GIVEN CLOUD COVER...BUT
A FEW STORMS ARE STARTING TO POP AS THAT MOVES EAST. SCATTERED
SHOWERS AND A FEW STORMS SHOULD DEVELOP IMMEDIATELY UPSTREAM AND
SOME ARE ANTICIPATED TO PROGRESS INTO THE CWA BETWEEN 6 AND 9 PM.
COVERAGE SHOULD REMAIN SCATTERED. AS NOTED EARLIER...THE SOMEWHAT
LIMITED INSTABILITY SHOULD KEEP COVERAGE 30-50 PERCENT ALONG THE
BOUNDARY. WHILE SOME 35 MPH PLUS GUSTS MAY ACCOMPANY A FEW STORMS
GIVEN MARGINAL EFFECTIVE DEEP LAYER SHEAR AND 700-1000 J/KG OF
DCAPE...THE ATMOSPHERE REMAINS NON-CONDUCIVE FOR SEVERE STORMS.
THE FOCUS FOR SHOWERS SHOULD CLEAR THE CWA BY MIDNIGHT WITH
CLOUDS QUICKLY CLEARING AS WELL. A SECONDARY MOMENTUM PUSH OF THE
DRIER AIR MASS SHOULD ARRIVE LATE ON NORTHERLY WINDS...WITH LOW
TEMPERATURES BY DAYBREAK NEAR NORMAL.
MTF
&&
.LONG TERM...
TUESDAY THROUGH SUNDAY...
TO BE ISSUED SHORTLY.
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* CHANCE OF SHRA/ISOLATED TSRA...MAINLY EARLY EVENING.
* NE WINDS ABOVE 10 KT LATE TONIGHT INTO EARLY TUESDAY.
KMD
//DISCUSSION...UPDATED 18Z...
CURRENT SHOWER ACTIVITY PUSHING THROUGH SOUTHERN WISCONSIN AND
CROSSING THE MISSISSIPPI RIVER INTO ILLINOIS IS TIED TO A POTENT
UPPER LEVEL SHORT WAVE IN IOWA. THIS ACTIVITY IS OUT AHEAD OF A
COLD FRONT SLATED TO COME THROUGH NORTHEAST ILLINOIS LATER THIS
EVENING. UPSTREAM OBSERVATIONS ARE IN A SLIGHTLY MORE MOIST
ENVIRONMENT AND HAVE BEEN ABLE TO SATURATE THE LOWER LEVELS TO
SUPPORT SOME RAIN. DEWPOINTS OVER NORTHEAST ILLINOIS ARE LOWER
THAN THESE AREAS...THEREFORE IN SPITE OF THE WAVE TRACKING RIGHT
THROUGH THE AREA THIS AFTERNOON...SHOWER ACTIVITY...AND ESPECIALLY
ANY LIMITED THUNDER POTENTIAL...WILL STRUGGLE INITIALLY. THERE IS
SOME CUMULUS DEVELOPMENT AHEAD OF THIS WAVE AS WELL. HAVE
INTRODUCED VCSH FOR THE TAFS FOR LATER THIS AFTERNOON TO ACCOUNT
FOR THIS PERIOD...BUT OVERALL IMPACTS SHOULD BE MINIMAL.
AFTER THE WAVE GOES PAST...IT APPEARS THE SLIGHTLY BETTER CHANCE
FOR SCATTERED SHOWER/ISOLATED THUNDER DEVELOPMENT WILL BE TIED TO
THE COLD FRONT...WHICH TRAILS THE UPPER LEVEL FORCING. WHILE
COVERAGE IS STILL IN QUESTION...BEST TIMING OF ACTIVITY WILL BE
JUST AHEAD OF THE FRONT IN THE 0-3Z TIME FRAME...WITH A SHIFT TO
NW WINDS 4-6Z. CURRENT TAFS PEG THE 0-2Z TIME FRAME AT THE
CHICAGO TERMINALS...COULD BE 1-3Z PER SOME CONVECTIVE ALLOWING
MODELS. A FLOP OVER TO NE WINDS IS EXPECTED OVERNIGHT WITH AN
INCREASE IN SPEEDS ABOVE 11 KT POSSIBLY INTO THE MORNING RUSH.
WINDS BACK TO NNW LATER TUESDAY....THOUGH THEY HANG ON NE CLOSER
TO THE LAKE.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM/HIGH IN TIMING IF ANY SHOWERS ARE TO OCCUR. LOW IN TSRA
DIRECTLY IMPACTING THE TERMINALS BUT MEDIUM IN SHRA.
* MEDIUM/HIGH ON WIND SPEEDS AND TRENDS.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT THROUGH FRIDAY...VFR. WX NIL.
SATURDAY...CHANCE TSRA THROUGH THE EVENING. OTRW...VFR.
SUNDAY...VFR. WX NIL.
KREIN
&&
.MARINE...
230 PM CDT
A COLD FRONT WILL MOVE SOUTHWARD ACROSS THE LAKE THIS EVENING
TURNING WINDS NORTH AND EVEN BRIEFLY NORTH-NORTHEAST. THERE IS
LIKELY TO BE SCATTERED SHOWERS AND A FEW STORMS AHEAD OF THE FRONT
ACROSS THE SOUTHERN HALF OF THE LAKE THROUGH MID-EVENING. THE
NORTHERLY WINDS BEHIND THE FRONT ARE EXPECTED TO REACH 15 TO 20 KT
FOR A 3-4 HOUR OR SO PERIOD LATE TONIGHT INTO EARLY TUESDAY
MORNING WITH POSSIBLY A FEW HIGHER GUSTS. BECAUSE OF THE SHORT
DURATION OF THE HIGHER SPEEDS...THIS IS EXPECTED TO ONLY BUILD
WAVES TO 2 TO 4 FEET ACROSS THE ILLINOIS AND INDIANA NEARSHORES ON
TUESDAY MORNING. HIGH PRESSURE IS THEN EXPECTED TO MOVE OVER THE
LAKE FOR A QUIET MIDWEEK PERIOD.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
231 PM CDT MON JUL 20 2015
.SHORT TERM...
230 PM CDT
THROUGH TONIGHT...
A SHORT WAVE TROUGH AXIS ORIENTED FROM SOUTHWEST WISCONSIN THROUGH
FAR WESTERN ILLINOIS AS OF 230 PM WILL MOVE OVER THE FORECAST
AREA LATE THIS AFTERNOON. A PATCH OF CLEARING HAS ALLOWED
TEMPERATURES TO REACH MID 80S WITH A FEW UPPER 80S ATTAINED IN
EASTERN AREAS. THESE ARE AT CONVECTIVE VALUES GIVEN THE DEW POINTS
AND ACCORDINGLY SOME CUMULUS...A FEW TOWERING...HAVE DEVELOPED IN
THE AREA. LAPSE RATES ABOVE THE LFC REMAIN NON-IMPRESSIVE PER
AMDAR AND RAP ANALYSIS SO WHILE SOME SHOWERS MAY DEVELOP/INCREASE
IN COVERAGE WITH THIS IMPULSE AS IT MOVES EAST...THUNDER MAY STILL
BE HARD TO COME BY.
A SURFACE COLD FRONT EXTENDING FROM A LOW AT THE SOUTHERN TIP OF
JAMES BAY IN CANADA WILL MOVE SOUTHEAST THROUGH THE AREA THIS
EVENING...BASICALLY RIGHT IN THE WAKE OF THE AFOREMENTIONED SHORT
WAVE TROUGH. THE AIR MASS AHEAD OF THE FRONT IN WISCONSIN TO
EASTERN IOWA HAS STRUGGLED TO DESTABILIZE GIVEN CLOUD COVER...BUT
A FEW STORMS ARE STARTING TO POP AS THAT MOVES EAST. SCATTERED
SHOWERS AND A FEW STORMS SHOULD DEVELOP IMMEDIATELY UPSTREAM AND
SOME ARE ANTICIPATED TO PROGRESS INTO THE CWA BETWEEN 6 AND 9 PM.
COVERAGE SHOULD REMAIN SCATTERED. AS NOTED EARLIER...THE SOMEWHAT
LIMITED INSTABILITY SHOULD KEEP COVERAGE 30-50 PERCENT ALONG THE
BOUNDARY. WHILE SOME 35 MPH PLUS GUSTS MAY ACCOMPANY A FEW STORMS
GIVEN MARGINAL EFFECTIVE DEEP LAYER SHEAR AND 700-1000 J/KG OF
DCAPE...THE ATMOSPHERE REMAINS NON-CONDUCIVE FOR SEVERE STORMS.
THE FOCUS FOR SHOWERS SHOULD CLEAR THE CWA BY MIDNIGHT WITH
CLOUDS QUICKLY CLEARING AS WELL. A SECONDARY MOMENTUM PUSH OF THE
DRIER AIR MASS SHOULD ARRIVE LATE ON NORTHERLY WINDS...WITH LOW
TEMPERATURES BY DAYBREAK NEAR NORMAL.
MTF
&&
.LONG TERM...
TUESDAY THROUGH SUNDAY...
TO BE ISSUED SHORTLY.
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* CHANCE OF SHRA/ISOLATED TSRA...MAINLY EARLY EVENING. SCHC LATE
THIS AFTERNOON.
* NE WINDS ABOVE 10 KT LATE TONIGHT INTO EARLY TUESDAY.
KMD
//DISCUSSION...UPDATED 18Z...
CURRENT SHOWER ACTIVITY PUSHING THROUGH SOUTHERN WISCONSIN AND
CROSSING THE MISSISSIPPI RIVER INTO ILLINOIS IS TIED TO A POTENT
UPPER LEVEL SHORT WAVE IN IOWA. THIS ACTIVITY IS OUT AHEAD OF A
COLD FRONT SLATED TO COME THROUGH NORTHEAST ILLINOIS LATER THIS
EVENING. UPSTREAM OBSERVATIONS ARE IN A SLIGHTLY MORE MOIST
ENVIRONMENT AND HAVE BEEN ABLE TO SATURATE THE LOWER LEVELS TO
SUPPORT SOME RAIN. DEWPOINTS OVER NORTHEAST ILLINOIS ARE LOWER
THAN THESE AREAS...THEREFORE IN SPITE OF THE WAVE TRACKING RIGHT
THROUGH THE AREA THIS AFTERNOON...SHOWER ACTIVITY...AND ESPECIALLY
ANY LIMITED THUNDER POTENTIAL...WILL STRUGGLE INITIALLY. THERE IS
SOME CUMULUS DEVELOPMENT AHEAD OF THIS WAVE AS WELL. HAVE
INTRODUCED VCSH FOR THE TAFS FOR LATER THIS AFTERNOON TO ACCOUNT
FOR THIS PERIOD...BUT OVERALL IMPACTS SHOULD BE MINIMAL.
AFTER THE WAVE GOES PAST...IT APPEARS THE SLIGHTLY BETTER CHANCE
FOR SCATTERED SHOWER/ISOLATED THUNDER DEVELOPMENT WILL BE TIED TO
THE COLD FRONT...WHICH TRAILS THE UPPER LEVEL FORCING. WHILE
COVERAGE IS STILL IN QUESTION...BEST TIMING OF ACTIVITY WILL BE
JUST AHEAD OF THE FRONT IN THE 0-3Z TIME FRAME...WITH A SHIFT TO
NW WINDS 4-6Z. CURRENT TAFS PEG THE 0-2Z TIME FRAME AT THE
CHICAGO TERMINALS...COULD BE 1-3Z PER SOME CONVECTIVE ALLOWING
MODELS. A FLOP OVER TO NE WINDS IS EXPECTED OVERNIGHT WITH AN
INCREASE IN SPEEDS ABOVE 11 KT POSSIBLY INTO THE MORNING RUSH.
WINDS BACK TO NNW LATER TUESDAY....THOUGH THEY HANG ON NE CLOSER
TO THE LAKE.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM/HIGH IN TIMING IF ANY SHOWERS ARE TO OCCUR. LOW IN TSRA
DIRECTLY IMPACTING THE TERMINALS BUT MEDIUM IN SHRA.
* MEDIUM/HIGH ON WIND SPEEDS AND TRENDS.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT THROUGH FRIDAY...VFR. WX NIL.
SATURDAY...CHANCE TSRA THROUGH THE EVENING. OTRW...VFR.
SUNDAY...VFR. WX NIL.
KREIN
&&
.MARINE...
230 PM CDT
A COLD FRONT WILL MOVE SOUTHWARD ACROSS THE LAKE THIS EVENING
TURNING WINDS NORTH AND EVEN BRIEFLY NORTH-NORTHEAST. THERE IS
LIKELY TO BE SCATTERED SHOWERS AND A FEW STORMS AHEAD OF THE FRONT
ACROSS THE SOUTHERN HALF OF THE LAKE THROUGH MID-EVENING. THE
NORTHERLY WINDS BEHIND THE FRONT ARE EXPECTED TO REACH 15 TO 20 KT
FOR A 3-4 HOUR OR SO PERIOD LATE TONIGHT INTO EARLY TUESDAY
MORNING WITH POSSIBLY A FEW HIGHER GUSTS. BECAUSE OF THE SHORT
DURATION OF THE HIGHER SPEEDS...THIS IS EXPECTED TO ONLY BUILD
WAVES TO 2 TO 4 FEET ACROSS THE ILLINOIS AND INDIANA NEARSHORES ON
TUESDAY MORNING. HIGH PRESSURE IS THEN EXPECTED TO MOVE OVER THE
LAKE FOR A QUIET MIDWEEK PERIOD.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
1248 PM CDT MON JUL 20 2015
.UPDATE...
ISSUED AT 1040 AM CDT MON JUL 20 2015
UPDATED THE FORECAST TO REMOVE PATCHY FOG THIS MORNING AND ALSO
LOWERED CHANCES OF SHOWERS AND THUNDERSTORMS THIS MORNING. ANOTHER
VERY WARM AND HUMID DAY EXPECTED WITH HIGHS IN THE MID TO UPPER
80S AND DEWPOINTS IN THE LOW TO MID 70S. HEAT INDICES THIS
AFTERNOON TO PEAK IN THE UPPER 80S/LOWER 90S OVER CENTRAL IL AND
MID TO UPPER 90S IN SOUTHEAST IL. MCS/MCV MOVING EAST OUT OF MO
INTO SW AND WEST CENTRAL IL WITH LEADING EDGE OF SHOWERS AND
THUNDERSTORMS AS FAR EAST AS A BEARDSTOWN TO JACKSONVILLE TO EAST
OF ST LOUIS LINE AND TRACKING EAST AT 35 MPH. RAP MODEL APPEARED
TO HAVE BEST HANDLE ON THIS MCS AND IT SPREADS QPF EAST ACROSS
AREAS FROM RUSHVILLE TO RANTOUL SOUTH DURING THE AFTERNOON. A COLD
FRONT OVER CENTRAL PARTS OF WI/IA AND SHORT WAVE OVER IA TO TRACK
SE INTO NW IL LATER THIS AFTERNOON AND TO HAVE SHOWERS AND
THUNDERSTORMS ALONG THIS BOUNDARY AS WELL MOVING INTO IL RIVER
VALLEY LATE TODAY. SO WILL CONTINUE CHANCES OF SHOWERS AND
THUNDESTORMS ACROSS CENTRAL/SE IL THIS AFTERNOON WITH HIGHEST
CHANCES OF RAIN FROM I-72 SOUTH. SPC HAS SHIFTED SLIGHT RISK OF
SEVERE STORMS THIS AFTERNOON/EVENING SOUTH OF CLAY...RICHLAND AND
LAWERENCE COUNTIES. BUT MARGINAL RISK OF SEVERE STORMS COVERS
CENTRAL IL CWA WITH 5-15% RISK OF HAIL AND DAMAGING WIND GUSTS.
MODEST MUCAPES ARE 1500-2500 J/KG SW CWA THIS AFTERNOON WHILE
MODEST BULK SHEAR IS 25-35 KTS. LOCALLY HEAVY RAINS AND FREQUENT
LIGHTNING ALSO POSSIBLE WITH STRONGER STORMS FROM MID AFTERNOON
INTO EARLY EVENING UNTIL SUNSET.
&&
.SHORT TERM...(TODAY)
ISSUED AT 318 AM CDT MON JUL 20 2015
CONVECTION THAT DEVELOPED NEAR ST.LOUIS LAST EVENING HAS SHIFTED
SOUTHEAST INTO EXTREME SOUTHERN ILLINOIS EARLY THIS MORNING. THE
STORMS ARC BACK TO THE NORTHWEST INTO PARTS OF WESTERN MO INTO
NORTHEAST KS ALONG A FRONTAL BOUNDARY WHICH LOOKS TO BE THE MAIN
FOCUS FOR ADDITIONAL DEVELOPMENT LATER TODAY. QUESTION BECOMES WHAT
AFFECT FURTHER NORTH INTO OUR AREA IT MAY HAVE ON COVERAGE OF
SHOWERS AND STORMS THIS AFTERNOON AND THIS EVENING AS ANOTHER COOL
FRONT TRACKS ACROSS THE AREA FROM THE NORTHWEST LATE TODAY.
USING THE TIMING AND COVERAGE OFF THE RAP MODEL WOULD SUGGEST A
SLOWER ONSET OF PRECIP THAN EARLIER EXPECTED WITH THE BULK OF THE
ACTIVITY TIED TO THE SURFACE BOUNDARY STRETCHING ACROSS MISSOURI
THRU FAR SOUTHERN ILLINOIS...WITH A SECONDARY BAND OF SHOWERS AND
STORMS SHOWING UP ALONG THE WEAK COOL FRONT WHICH IS FORECAST TO BE
JUST TO OUR NORTHWEST LATE THIS AFTERNOON. THE HIGHER POPS WILL BE
FOR MAINLY THIS AFTERNOON WITH ONLY LOW CHANCE POPS FOR PRECIP THIS
MORNING ACROSS OUR WEST. MIXED LAYER CAPES OFF THE NAM MODEL FOR
THIS AFTERNOON ARE EXPECTED TO RANGE FROM 1500-2000 J/KG WITH 0-6KM
SHEAR VALUES OF 30 KTS. 700-500 MB LAPSE RATES NOT LOOKING THAT
IMPRESSIVE THOUGH...BUT STILL CAN`T RULE OUT A STRONG TO LOCALLY
SEVERE STORM THAT MAY BE CAPABLE OF PRODUCING GUSTY WINDS ALONG WITH
HEAVY RAINFALL DURING THE MID TO LATE AFTERNOON HOURS. SPC HAS
SHIFTED THE SLIGHT RISK FURTHER SOUTH AND WEST...CLOSER TO THE
AFOREMENTIONED BOUNDARY OVER MISSOURI. WITH THE MAIN CONVECTIVE
FRONT EXPECTED TO REMAIN TO OUR SOUTH...IT APPEARS THAT IS WHERE THE
MORE CONCENTRATED AREA OF HEAVY RAINFALL WILL OCCUR...AS A
RESULT...WILL NOT BE INCLUDING ANY FLASH FLOOD WATCH AT THIS TIME
FOR OUR FAR WESTERN COUNTIES WHICH RECEIVED HEAVY RAINFALL LAST
NIGHT.
.LONG TERM...(TONIGHT THROUGH SUNDAY)
ISSUED AT 318 AM CDT MON JUL 20 2015
SEVERAL WEAK BOUNDARIES IN THE REGION AND WILL CONTINUE TO PROVIDE
FOCUS FOR AN IMPULSE BRINGING PRECIP TODAY AND INTO TONIGHT.
HOWEVER, MODELS ARE SHIFTING SOUTH SOMEWHAT AND FOR THE MOST PART,
PUSH A COLD FRONT THROUGH THE STATE CONSIDERABLY FASTER TONIGHT.
GFS AND ECMWF ARE LARGELY DRY AFTER 06Z, WITH THE NAM STILL
STRUGGLING. HAVE PUSHED THE GRIDS CLOSER TO THAT SOLUTION, BUT THE
SLOWING NATURE OF THE BOUNDARY TOWARDS TOMORROW MORNING...HAVE KEPT
THE SLIGHTS ALONG AND SOUTH OF I-70, ALTHOUGH THOSE SMALL POPS MAY
ALSO GET PULLED WITH SUBSEQUENT FORECASTS IF THE TRENDS CONTINUE.
ELUSIVE DRY TREND IS BACK IN THE FORECAST FROM TOMORROW AFTERNOON
THROUGH WED EVENING, AND MUCH OF THURSDAY. THURSDAY A WAVE DIVES
INTO THE REGION AND ALTHOUGH MUCH OF THE PRECIP LOOKS TO PASS TO THE
SW, SOME SMALL POPS ARE WORKING THEIR WAY INTO THE SUPERBLEND ALONG
AND SW OF A LINE FROM HAVANA TO LAWRENCEVILLE. CONCERNED WITH THE
LOOK OF THE MODELS IN THAT TIME FRAME ARE NOT PROPERLY REPRESENTED
IN THE SUPERBLEND JUST YET. GFS IS MORE AGGRESSIVE WITH THE QPF ON
THURSDAY NIGHT OVER IL...AND ECMWF PASSES THE WAVE ALOFT IN THE SAME
TIME FRAME WITH LITTLE TO SHOW AT THE SFC. EXPECT SOME CHANGES IN
THIS PORTION OF THE FORECAST. WARMING TREND CONTINUES THROUGH THE
END OF THE WEEK, WITH THE HIGHEST TEMPS IN THE FORECAST NEXT WEEKEND
AGAIN. WITH THE WARM TEMPS, A RIDGE BUILDS IN THE DESERT SW AND
SOUTHERN PLAINS. ILLINOIS HAS VERY LITTLE IN THE WAY OF STEERING
FLOW AND MODELS ARE A BIT MORE SCATTERED WITH WEAK WAVES...WITH THE
GFS AND ECMWF DIVERGING AT THE WEEKEND DEALING WITH A TROF PASSING
ACROSS THE NRN TIER OF THE CONUS. FOR NOW, SLIGHT/CHANCE POPS
THROUGH THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1245 PM CDT MON JUL 20 2015
MCV SOUTH OF VANDALIA WILL TRACK EAST ACROSS SE CWA THIS AFTERNOON
WHERE BEST CHANCES OF SHOWERS AND THUNDERSTORMS WILL BE SOUTH OF
I-72. MEANWHILE A COLD FRONT OVER CENTRAL PARTS OF WI/IA WILL
MOVE SE INTO THE IL RIVER VALLEY BY SUNSET WHILE A SHORT WAVE OVER
IA MOVES INTO IL BY 00Z/7 PM. THIS MOVING INTO A WARM/HUMID AIR
MASS WITH DEWPOINTS OF 70-75F TO DEVELOP ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS DURING MID/LATE AFTERNOON AND CONTINUE
UNTIL EARLY OR MID EVENING. MUCAPES OF 1500-2500 J/KG OVER SW CWA
WHILE BULK SHEAR OF 25-35 KTS TO SUPPORT A FEW STRONG TO POSSIBLE
SEVERE THUNDERSTORMS FROM 20Z-01Z. MVFR CEILINGS AND VSBYS
POSSIBLE WITH THUNDERSTORMS FROM MID AFTERNOON INTO EARLY EVENING.
COLD FRONT TO MOVE SE TO PIA BETWEEN 06Z-07Z AND REACH DEC AND CMI
BY 09Z WITH SW WINDS UNDER 10 KTS SHIFTING NW OVERNIGHT AND NORTH
TUE MORNING.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...07
SHORT TERM...SMITH
LONG TERM...HJS
AVIATION...07
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
136 PM EDT MON JUL 20 2015
.SYNOPSIS...
ISSUED AT 134 PM EDT MON JUL 20 2015
HIGH PRESSURE WILL QUICKLY MOVE ACROSS THE REGION TODAY. A WEAK
COLD FRONT WILL APPROACH LATE THIS AFTERNOON AND MOVE ACROSS THE
AREA TONIGHT. THERE WILL BE A SMALL CHANCE FOR SHOWERS AND
THUNDERSTORMS NEAR THIS FRONT. SKIES WILL BE PARTLY TO MOSTLY
CLOUDY ACROSS THE AREA THIS AFTERNOON. HIGH TEMPERATURES WILL BE
IN THE LOWER TO MIDDLE 80S. LOWS TONIGHT WILL BE IN THE LOWER AND
MIDDLE 60S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM EDT MON JUL 20 2015
WEAK HIGH PRESSURE WILL MOVE EAST TODAY WHILE SHORT WAVE AND
ASSOCIATED COLD FRONT APPROACH LATE THIS AFTERNOON AND MOVE
THROUGH CWA TONIGHT. FORCING AND MOISTURE FLUX WEAK WITH THIS
SYSTEM BUT ENOUGH AMBIENT MOISTURE AND WEAK LIFT TO SUPPORT CHANCE
POPS FROM LATE THIS AFTERNOON THROUGH TONIGHT. RAP AND HRRR SEEM
TO HAVE BEST HANDLE ON UPSTREAM CONVECTION EARLY THIS MORNING.
BOTH MODELS WEAKEN CONVECTION AS IT MOVES EAST TODAY BUT STILL
SHOW SOME SCATTERED DEVELOPMENT IN OUR AREA BY LATE AFTERNOON AND
THROUGH THE EVENING. SEVERE WEATHER THREAT LOOKS MINIMAL AS
MUCAPES ONLY IN THE 1-2K J/KG RANGE AT BEST AND 0-3KM SHEAR
BETWEEN 20 AND 30KTS. LACK OF STRONG CONVERGENCE AND OVERNIGHT
TIMING SHOULD ALSO LIMIT DEVELOPMENT. COLD FRONT WILL PUSH SOUTH
BY EARLY TUESDAY MORNING ENDING PCPN CHANCES FROM NORTH TO SOUTH
OVERNIGHT WITH EVEN DRIER AIR WORKING IN.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 349 AM EDT MON JUL 20 2015
A SECOND SURGE OF COOL AIR WILL SPREAD ACROSS THE REGION BEHIND A
COLD FRONT EARLY TUESDAY. A SURFACE HIGH PRESSURE SYSTEM WILL BE
OVER THE REGION FOR THE NEXT SEVERAL DAYS. TEMPERATURES WILL FALL
WELL BELOW NORMAL BEHIND THE COOL FRONT TUESDAY NIGHT...FOLLOWED
BY A GRADUAL MODERATION LATER IN THE WEEK. THE SUBTROPICAL RIDGE
WILL EXTEND WELL INLAND...INTO THE SOUTHERN PLAINS... AND
EVENTUALLY BUILD FURTHER WEST INTO THE SOUTHWEST CONUS. HIGHS HERE
WILL BE IN THE 70S TUESDAY AND WEDNESDAY...RISING INTO THE 80S BY
FRIDAY AS A PORTION OF THE UPPER LEVEL RIDGE TEMPORARILY BUILDS
INTO THE AREA. CONDITIONS SHOULD BE DRY THROUGH FRIDAY...BUT SOME
ENERGY SHOULD BE ABLE TO TOP THE UPPER LEVEL RIDGE AND BRING A
CHANCE FOR THUNDERSTORMS THIS COMING WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 133 PM EDT MON JUL 20 2015
VFR CONDITIONS EXPECTED THROUGH THE TAF PD. CONTINUED WITH VCSH
MENTION AT KSBN AS COLD FRONT APPROACHES FROM THE WEST...HOWEVER
PUSHED TIMING BACK A BIT AND CONFIDENCE ON ANY PRECIPITATION IS
CONTINUING TO LOWER. FRONT WILL SLIDE THROUGH THE TERMINALS
BETWEEN 06Z AND 12Z...WITH WINDS VEERING NORTHERLY.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...SKIPPER
AVIATION...NG
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AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
322 PM EDT Mon Jul 20 2015
.SHORT TERM (Now through Tuesday Night)...
Issued at 315 PM EDT Mon Jul 20 2015
Plenty of debris cloudiness overhead as a result of convection that
affected western Kentucky early this morning. Within the last hour
we have seen storms develop where the old outflow boundary is
interacting with the Cumberland Escarpment, but these storms are
already pushing onto the Plateau as we speak. Main challenge is
timing and impact of the round, or rounds of storms that could
affect mainly central Kentucky through tonight.
Even the hi-res models seem to really be struggling from one run to
the next, so this is quite a low-confidence forecast. A couple of
weak swirls were apparent in visible imagery over southern Illinois
and western Kentucky, but even this juicy environment is not
responding yet. Earlier HRRR runs have seemed to be the only models
with any handle on initial conditions, and have hinted that one
round of convection could come through in the hours just before
sunset, with others keying on the actual front which would arrive
around midnight. Less confident in the SPC slight risk as progged
DCAPE is well out of sync with current analysis, and the effective
source of lift remains unclear. Best chance is from roughly 22Z to
05Z Tue, but not likely to affect that entire time period.
Even with the low-confidence forecast, any storms that do develop
could be prolific rain producers due to high precipitable water and
storm motion parallel to a nearly stationary boundary. Flash Flood
Guidance is quite low especially across the Bluegrass, where 1-hr
FFG is 1.5 inches or less in many places. Therefore will continue
with the Flash Flood Watch until Tuesday morning, but no extension
is planned unless convective trends show themselves more clearly.
Whatever organized storms we see should clear the area around
midnight or not too long after. Wind shift arrives by mid-morning,
but we`ll hang on to high dewpoints and chance POPs through the day
as fropa seems to occur in pieces. Mid-level WNW winds picking up to
around 30 kt could support a few strong storms with gusty winds over
east-central KY, but organized SVR potential is farther north and
east as our precip chances will be diminishing as the afternoon
progresses. Chance POPs in the middle of the day will be dropping
off by mid/late afternoon, with only south central KY in a slight
chance for storms for Tue night. Drier air will be filtering in,
with dewpoints dropping into the lower/mid 60s and temps dropping to
the upper 60s/near 70.
.LONG TERM (Wednesday through Monday)...
Issued at 300 PM EDT Mon Jul 20 2015
The synoptic pattern at the start of the long term period will
feature generally northwest flow across the Ohio Valley, as ridging
over the south-central CONUS remains in place. This ridging will
actually build NNE into the region by this weekend, bringing a
return to the hot and humid conditions.
A weak frontal boundary will have pushed into TN at the start of the
long term period. There is some discrepancy in the guidance as to
how far south this boundary will get, which will be the deciding
factor as to whether or not southern KY ends up dry. For now, will
continue with slight chance pops across southern KY Wednesday into
Thursday as impulses riding along this boundary may be enough to
bring precip into the region, but suspect most will end up dry.
Given the majority of the region will be on the northern side of the
front, temperatures and humidity values will be rather comfortable.
Look for highs in the low to mid 80s with dewpoints in the low to
mid 60s, perhaps pushing into the upper 60s over southern KY.
Heading into Friday and through the upcoming weekend, upper-level
ridging will build back into the Ohio Valley which will bring
increasing heat and humidity. The region will still be on the
periphery of the mid-level westerlies/northwesterlies, so cannot
completely rule out thunderstorm chances this weekend. It appears
the best chance for a disturbance to impact the region may come
Saturday night into Sunday, but confidence in that scenario is quite
low and does not warrant any higher mention than just slight chance
to chance POPs (20-30%). Otherwise, it will be hot and humid as
upper-level ridging builds in and 850mb temps rise back to near
20C. Look for highs back in the upper 80s and lower 90s with heat
indices from 95-100 degrees at times.
&&
.AVIATION (18Z TAF Update)...
Updated 1250 PM EDT Mon Jul 20 2015
Decent cu field already developing anywhere that the mid/high cloud
deck has thinned. Bases are only between 3-4K feet as temp/dewpoint
spreads are not that big. Expect enough continued cu development for
ceilings this afternoon, but should remain VFR. Otherwise we`ll
remain convectively quiet until very late in the afternoon, at which
point a weakening precip shield now moving across southern Illinois
will arrive.
Best chance for storms will be this evening, either with the leading
upper impulse or if convection develops along the actual front,
which would swing in closer to midnight. Still enough uncertainty in
the timing to limit the mention to VCTS/CB over a period longer than
we expect actual impacts. Will stay VFR, but brief IFR will likely
accompany any thunderstorm that directly impacts an airport.
SW winds will come around to NW around daybreak for SDF, but more
like mid to late morning in BWG and LEX.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...FLASH FLOOD WATCH through Tuesday morning FOR KYZ029>043-045>049-
054>057-065>067-077-078-081-082.
IN...FLASH FLOOD WATCH through Tuesday morning FOR INZ078-079-091-092.
&&
$$
Short Term........RAS
Long Term.........KJD
Aviation..........RAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
200 PM EDT MON JUL 20 2015
.UPDATE...
ISSUED AT 1057 AM EDT MON JUL 20 2015
ISOLATED RAIN SHOWERS CONTINUE ACROSS THE CWA. WHILE LATEST HI RES
MODELS HAVE NOT BEEN PERFORMING VERY WELL FOR THE LAST FEW
DAYS...THE HRRR IS ACTUALLY INITIATING QUITE WELL OVER THE LAST
COUPLE HOURS. BASED ON THE LATEST RADAR TRENDS...AS WELL AS THE
LATEST HRRR...DON/T EXPECT THINGS TO REALLY START TICKING UP TO
SCATTERED TO NUMEROUS UNTIL LATE IN THE AFTERNOON. AS SUCH...WENT
AHEAD AND CUT BACK POPS DURING THE REST OF THE MORNING TO SLOW
DOWN THE INCREASE IN COVERAGE. ALSO...LOADED IN THE LATEST
OBSERVATIONAL DATA INTO THE NEAR TERM GRIDS FOR TEMPS...DEW
POINTS...AND WINDS...TO MAKE SURE OUR FORECAST MATCHED UP WITH THE
ONGOING CONDITIONS.
UPDATE ISSUED AT 649 AM EDT MON JUL 20 2015
THE FORECAST IS IN GOOD SHAPE SO FAR THIS MORNING. ISOLATED RAIN
SHOWERS ARE ALREADY MOVING INTO THE AREA FROM THE WEST. THIS TREND
IS EXPECTED TO CONTINUE THROUGHOUT THE MORNING...WITH
THUNDERSTORMS GETTING INTO THE MIX BY 15 OR 16Z. ASIDE FROM
INGESTING THE LATEST OBS DATA INTO THE FORECAST GRIDS...NO CHANGES
TO THE FORECAST WERE NECESSARY.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 301 AM EDT MON JUL 20 2015
SCATTERED SHOWERS AND THUNDERSTORMS ARE BRINGING LOCALLY HEAVY
RAINFALL TO PORTIONS OF EASTERN KENTUCKY THIS OVERNIGHT.
PIKE...ROCKCASTLE...AND LAUREL COUNTIES IN PARTICULAR WERE
EXPERIENCING HEAVY RAIN AT AFD ISSUANCE. ISOLATED TO SCATTERED
SHOWERS AND STORMS WILL LIKELY CONTINUE THROUGH THE NIGHT...WITH A
GRADUAL WEAKENING TREND EXPECTED THROUGH SUN RISE. SCATTERED TO
NUMEROUS SHOWERS AND STORMS ARE EXPECTED TO FIRE UP AGAIN THIS
AFTERNOON...AS A COLD FRONT APPROACHES FROM THE NORTH. SOME OF THE
STORMS THIS AFTERNOON COULD BE STRONG...WITH GUSTY WINDS...LOCALLY
HEAVY RAINFALL AND SMALL HAIL ALL POSSIBLE. SCATTERED STORMS ARE
EXPECTED TO CONTINUE AGAIN THROUGH TUESDAY MORNING. THE SHOWERS
AND STORMS WILL THEN BECOME NUMEROUS AGAIN TUESDAY AFTERNOON AND
EVENING...AS THE COLD FRONT PUSHES SLOWLY ACROSS THE AREA. THE
MODELS IN GENERAL DO NOT HAVE A GOOD HANDLE ON THE CURRENT
WEATHER...SO A MODIFIED BLEND OF MODEL DATA WAS USED TO CREATE THE
FORECAST.
TEMPERATURES THROUGH TOMORROW ARE EXPECTED TO RUN AT OR SLIGHTLY
ABOVE NORMAL TODAY...RIGHT AT NORMAL TOMORROW...AND SEVERAL
DEGREES ABOVE NORMAL TONIGHT. TODAYS HIGHS ARE EXPECTED TO TOP OUT
IN THE MID TO UPPER 80S FOR MOST LOCATIONS...WITH A FEW STRAY
READINGS AT OR JUST ABOVE 90 NOT OUT OF THE QUESTION ALONG THE
TENNESSEE BORDER. TONIGHTS LOWS WILL ONCE AGAIN BE QUITE
BALMY...WITH MIN READINGS IN THE LOWER 70S ON TAP. HIGHS ON
TUESDAY SHOULD COME IN RIGHT ABOUT NORMAL...WITH MAX READINGS IN
THE MID 80S EXPECTED.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 301 AM EDT MON JUL 20 2015
WHILE THE LONG TERM PORTION OF THE FORECAST CERTAINLY LOOKS QUIETER
AND LESS ACTIVE...STILL LOTS OF UNCERTAINTY IN THE FORECAST...ALL
REVOLVING AROUND EXACTLY HOW FAR SOUTH THE FRONTAL BOUNDARY MAKES IT
ON TUESDAY. GFS PUSHES THIS BOUNDARY OFF TO THE SOUTH...WITH DRY
WEATHER ARRIVING FOR THE MIDDLE OF THE WEEK...WHILE THE ECMWF HANGS
UP THE BOUNDARY FARTHER NORTH...KEEPING AT LEAST THE SOUTHERN HALF
OF KENTUCKY WITH A THREAT OF SHOWERS/STORMS THROUGH THE REMAINDER OF
THE WEEK. GIVEN THE ABUNDANCE OF WET WEATHER LATELY AND THE TENDENCY
FOR FRONTS TO NOT MAKE A GOOD PUSH SOUTH THIS TIME OF YEAR...HAVE
OPTED TO KEEP SOME POPS ACROSS SOUTHERN KENTUCKY THROUGH MOST OF THE
WEEK. PLAN TO KEEP THINGS IN THE 20 TO 30 RANGE FOR POPS GIVEN THE
UNCERTAINTY. NORTHERN KENTUCKY...HAS A BETTER SHOT OF HAVING A LONGER
PERIOD OF DRY WEATHER THROUGH THE SECOND HALF OF THE WEEK. MODELS
ARE ALL OVER THE PLACE AS WE HEAD INTO NEXT WEEKEND WITH THE GFS
BRINGING OUR NEXT SYSTEM INTO THE AREA...WHILE THE ECMWF REMAINS
DRY. THUS...WILL JUST STAY WITH A COMPROMISED APPROACH AND GO WITH
SOME LOW POPS FOR SATURDAY INTO SUNDAY.
DESPITE THE MODEL DISAGREEMENTS...IT DOES LOOK LIKE SOME REASONABLE
AGREEMENT ON TEMPERATURES AS NO MATTER THE SOLUTION...WE SHOULD SEE
COOLER TEMPERATURES FOR THE MIDDLE OF THE WEEK AS THE FRONTAL
BOUNDARY SHOULD SET UP SOUTH OF THE AREA...OR EVEN IF IT
DOESN`T...WE WILL SEE MORE CLOUD COVER WHICH WILL ALSO KEEP
TEMPERATURES LOWER. TEMPERATURES WILL BEGIN TO WARM AGAIN HEADING
INTO NEXT WEEKEND AS THE TROUGH OVER THE EAST BREAKS DOWN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 157 PM EDT MON JUL 20 2015
SHOWERS AND THUNDERSTORMS ARE FINALLY STARTING TO POP UP ACROSS
SOUTHEAST KY...AND WILL CONTINUE TO INTENSIFY OVER THE NEXT
COUPLE OF HOURS...BECOMING MORE SCATTERED IN NATURE. SKY
CONDITIONS ACROSS THE REGION WILL BE A MIX OF SCT AND BKN UPPER
END MVFR CONDITIONS THROUGH THE AFTERNOON AND EVENING. IN ADDITION
TO THE ALREADY HIGH MOISTURE RATES...ANY SHOWERS WHICH DO AFFECT
TAF SITES WILL LIKELY LEAD TO FOG DEVELOP OVERNIGHT. THE EXACT
IMPACTS FROM THIS FOG ARE STILL SOMEWHAT UNCERTAIN...SO WHILE
ONLY IFR CONDITIONS ARE FORECAST...SOME MOMENTS OF EVEN LOWER
CONDITIONS ARE POSSIBLE...ESPECIALLY NEAR DAWN AS SOME OF THE
VALLEY FOG LIFTS. SHOWERS AND THUNDERSTORMS WILL ALSO BE ONGOING
ACROSS PORTIONS OF THE CWA DURING THE NIGHT...AND WILL CONTINUE
ON INTO THE DAY TUESDAY. VIS WILL LIKELY BE REDUCED TO SOME
VARYING DEGREE AT THE TAF SITE UNDER ANY STORM WHICH AFFECTS THEM.
OVERALL...WINDS WILL REMAIN LIGHT...GENERALLY LESS THAN 5 KNOTS.
HOWEVER...SOME OF THE LARGER STORMS MAY PRODUCE MUCH STRONGER WIND
GUSTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR KYZ044-050>052-
058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...JMW
SHORT TERM...AR
LONG TERM...KAS
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
130 PM CDT MON JUL 20 2015
.AVIATION...
RIDGE ALOFT WITH KEEP STORMS AND CLOUDS IN CHECK ACROSS SOUTHEAST
TEXAS AND SOUTHWEST LOUISIANA. STORMS OVER EASTERN LOUISIANA WILL
MOVE INTO SOUTH-CENTRAL LOUISIANA DURING THE LATE AFTERNOON HOURS.
THIS PRECIP LOOKS TO BE LIMITED ATTM. BUT THOSE LCTNS GETTING THE
STORMS WILL SEE LWR CLD DECKS. CONDS TO IMPROVE TWRDS SS.
&&
.PREV DISCUSSION... /ISSUED 1047 AM CDT MON JUL 20 2015/
DISCUSSION...
GENERALLY DRY HOT AND HUMID CONDITIONS EXPECTED AGAIN TODAY AS
HIGH PRES REMAINS ANCHORED OVER THE REGION. A FEW SHOWERS OR TSTMS
WILL BE POSSIBLE MAINLY DURING THE AFTN AND PRIMARILY ACRS
PORTIONS OF ACADIANA AND THE LOWER ATCHAFALAYA BASIN.
MEANWHILE...THE BIGGEST ISSUE WILL BE THE ONGOING HEAT WITH
TEMPERATURES ALREADY NEAR 90 DEGREES AT 10 AM THIS MORNING ON
THEIR WAY TO HIGHS IN THE MIDDLE AND UPPER 90S. COMBINED WITH THE
HUMIDITY...HEAT INDEX VALUES WILL BE WELL ABV 100 DEGREES WITH
SEVERAL LOCATIONS ACRS THE ERN HALF OF THE AREA APPROACHING 110.
THE HEAT ADVISORY REMAINS IN EFFECT FOR AREAS EAST OF AN
ALEXANDRIA TO EUNICE TO PECAN ISLAND LINE THROUGH EARLY THIS
EVENING.
OVERALL...FEW CHANGES TO THE CURRENT FCST. MADE SOME MINOR
ADJUSTMENTS TO THE POP/WX GRIDS TO REFLECT RECENT RADAR
OBS/TRENDS...BUT THESE CHANGES WERE NOT SIGNIFICANT ENOUGH TO
WARRANT AN UPDATE TO THE ZONES. 24
PREV DISCUSSION... /ISSUED 644 AM CDT MON JUL 20 2015/
AVIATION...VFR WITH LIGHT WINDS WITH THE POSSIBLE EXCEPTION OF
BPT WHERE I LEFT IN THE TEMPO MVFR CIG/VIS FOR THE NEXT COUPLE OF
HOURS...TROPICAL CU UNTIL THE BOUNDARY LAYER MIXES OUT AND SOME
LIGHT FOG POSSIBLE AS DEW POINT SPREAD IS WITHIN A DEGREE.
INCLUDED VCTS THIS AFTERNOON FOR ACADIANA TERMINALS LFT AND ARA.
THE GFS AND HRRR AGREE AS DOES PERSISTENCE.
SWEENEY
PREV DISCUSSION... /ISSUED 347 AM CDT MON JUL 20 2015/
DISCUSSION...
AREA REMAINS ON THE SOUTHERN PERIPHERY OF RIDGE CENTERED NEAR THE
ARKLATEX REGION. TEMPERATURES ARE IN THE MID 70S TO LOWER 80S WITH
JUST SOME HIGH CLOUDS MOVING ACROSS THE AREA. SO FAR THE RADAR IS
CLEAR.
GUIDANCE CONTINUES TO INDICATE LITTLE CHANGE IN THE PATTERN. THERE
IS AN AREA OF DEEPER MOISTURE LOCATED ALONG THE CENTRAL GULF COAST
THAT WILL BE MOVING WEST DURING THE DAY. THIS SHOULD CAUSE AN
INCREASE IN AREAL COVERAGE OF SHOWERS AND THUNDERSTORMS ACROSS
SOUTH CENTRAL LOUISIANA TODAY. OUTSIDE OF THE SHOWERS AND
THUNDERSTORMS...HEAT INDEX VALUES WILL BE GETTING UP OVER 108
ACROSS EASTERN PORTIONS OF THE AREA AND THE CURRENT ADVISORY STILL
LOOKS GOOD.
STILL LOOKS LIKE THE DEEPER MOISTURE WILL CONTINUE TO SPREAD WEST
TUESDAY AND WEDNESDAY. WITH THIS MOISTURE MORE CLOUDS AND A FEW
SHOWERS WILL DIAL BACK THE AFTERNOON HIGHS JUST A TAD. WHILE THERE
ARE RAIN CHANCES...THE POPS ARE STILL BELOW CLIMO FOR THIS TIME OF
YEAR.
FOR LATE WEEK...THE CENTER OF THE RIDGE GETS A LITTLE CLOSER AND
SOMEWHAT DRIER AIRMASS WILL RESULT IN LOWER POPS AND TEMPERATURES
WARMING UP ONCE AGAIN. DEEPER MOISTURE IS FORECAST TO MOVE OVER
DURING THE WEEKEND WITH SLIGHTLY HIGHER RAIN CHANCES...BUT STILL
AT OR SLIGHTLY BELOW CLIMO.
27
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 76 96 76 95 / 10 20 10 20
LCH 78 93 78 92 / 10 20 10 20
LFT 78 93 78 93 / 10 30 10 40
BPT 77 94 78 93 / 10 20 10 20
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR LAZ028-029-032-033-
043>045-052>055.
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
328 PM EDT MON JUL 20 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM EDT MON JUL 20 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A WNW FLOW ALOFT
ALONG THE CNDN BORDER E OF AN UPR RDG OVER THE ROCKIES. SHRTWV AND
ASSOCIATED SFC LO EMBEDDED IN THIS FLOW ARE MOVING THRU NW
ONTARIO...WITH ATTENDANT SFC COLD FNT STRETCHING INTO MN. SOME ISOLD
SHOWERS ARE PRESENT JUST AHEAD OF THIS FNT AND MOVING THRU NW LK SUP
TOWARD THE KEWEENAW. BUT WITH AN ABSENCE OF MSTR INFLOW INTO THE
SHRTWV AND NOCTURNAL COOLING...THESE SHOWERS HAVE TENDED TO DIMINISH
WITH TIME TO THE S OF SHARPER DPVA/DEEP LYR QVECTOR CNVGC PASSING TO
THE N CLOSER TO THE SHRTWV TRACK. OTRW...STEADY WSW WINDS AHEAD OF
THE FNT ARE RESULTING IN WELL ABV NORMAL TEMPS EARLY THIS MRNG.
MAIN FCST CONCERNS IN THE SHORT TERM WL BE ON POPS TODAY ASSOCIATED
WITH APRCHG COLD FNT AS WELL AS GUSTY WINDS.
TODAY...SHRTWV MOVING THRU NW ONTARIO JUST N OF LK SUP IS FCST TO
MOVE QUICKLY ESEWD TO NEAR THE QUEBEC/ONTARIO BORDER BY 00Z THIS
EVNG. ATTENDANT COLD FNT IS PROGGED TO SWING THRU THE CWA...REACHING
THE SE ZNS ARND 18Z BEFORE CONTINUING AWAY TO THE SE IN THE AFTN.
WHILE THERE MAY BE SOME ISOLATED SHOWERS THIS MRNG OVER MAINLY THE
NRN TIER CLOSER TO THE SHRTWV TRACK/CORE OF SHARPER FORCING...EXPECT
A MAINLY DRY FROPA BECAUSE THE TIMING WL BE AHEAD OF THE FULL IMPACT
OF DAYTIME HEATING. A BIT CONCERNED THE LATER ARRIVAL EARLY THIS
AFTN OVER THE SE CWA WITH SOME ENHANCED LLVL CNVGC WITH LK BREEZE
OFF LK MI COULD RESULT IN SOME ISOLD SHOWERS/TS THERE AS HINTED AT
BY SOME OF THE HIER RES MODELS...SO DID MENTION SOME SCHC POPS IN
THIS AREA BEFORE MORE VIGOROUS DRYING AND THE ARRIVAL OF LARGER
SCALE DNVA/DEEP LYR QVECTOR DVGC ENDS THE PCPN CHCS BY LATE AFTN.
EXPECT SOME GUSTY WINDS AGAIN TODAY AHEAD OF AND FOLLOWING THE COLD
FROPA WITH H925 WSW WINDS UP TO 25-30 KTS SHIFTING TO THE WNW IN THE
AFTN. EXPECT THE HIEST MAX TEMPS INTO THE 80S OVER THE SCNTRAL. COOL
AIR ADVECTION IN THE WAKE OF THE FROPA WITH H85 TEMPS PROGGED TO
FALL TO NEAR 10C OVER THE NW CWA BY 00Z WL LIMIT THE DAYTIME DIURNAL
TEMP RISE TO THE NW.
TNGT...ANOTHER SHRTWV/SOME MID LVL MSTR ARE FCST TO SWING SE INTO
THE UPR LKS WITHIN DEEPENING UPR TROF. WHILE THERE MAY BE SOME CLDS
ACCOMPANYING THIS DISTURBANCE...NONE OF THE MODELS SHOW ANY PCPN
OVER UPR MI. WL MAINTAIN A DRY FCST DURING PERIOD OF NOCTURNAL
COOLING. OVERNGT LOWS WL BE QUITE A BIT LOWER THAN THIS MRNG WITH
SOME UPR 40S AT SOME OF THE COOL SPOTS. BUT STEADY NW WINDS WL TEND
TO LIMIT THE TEMP DROP.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 328 PM EDT MON JUL 20 2015
A FAIRLY QUIET LONG TERM FORECAST IS IN STORE FOR UPPER
MICHIGAN...AS THE UPPER GREAT LAKES REGION WILL BE INCREASINGLY
INFLUENCED BY AN UPPER RIDGE. AS THIS OCCURS...A HIGH PRESSURE RIDGE
STRETCHING FROM NORTHERN MANITOBA TO THE MID MISSISSIPPI VALLEY ON
TUESDAY EVENING WILL SLOWLY PUSH EAST ACROSS THE REGION THROUGH
THURSDAY...BEFORE DEPARTING BY FRIDAY MORNING. WILL MODELS SHOWING
LIMITED MOISTURE...EXPECT MOSTLY CLEAR SKIES THROUGH MUCH OF THE
PERIOD AND MAYBE JUST A FEW DIURNAL CU DURING THE AFTERNOON HOURS. A
FEW MODELS ARE SHOWING A WEAK SHORTWAVE UNDERCUTTING THE RIDGE
WEDNESDAY AFTERNOON IN THE DAKOTAS AND THEN NEARING THE AREA ON
WEDNESDAY NIGHT INTO THURSDAY...BUT AT THIS POINT...THINK THE
PRECIPITATION SHOULD STAY TO THE SOUTHWEST OF THE AREA AND KEPT THE
SLIGHT CHANCE POPS ALONG OR JUST SOUTHWEST OF THE WISCONSIN BORDER
OVER THE WESTERN U.P. TEMPERATURES DURING THIS PERIOD LOOK TO BE
NEAR NORMAL WITH DEEP MIXING DURING MOST AFTERNOONS. DID TREND
DEWPOINTS DOWN A COUPLE DEGREES ON WEDNESDAY...WHICH PUSHES RH
VALUES INTO THE LOWER 30S. BUT WITH WINDS GENERALLY STAYING BELOW
15KTS...THINK FIRE WEATHER CONCERNS WILL BE LIMITED EVEN WITH THE
RECENT DRIER WEATHER.
THE BEST CHANCE FOR PRECIPITATION WILL COME LATE FRIDAY INTO THE
FIRST HALF OF THE WEEKEND...AS THE UPPER TROUGH CURRENTLY MOVING
THROUGH BRITISH COLUMBIA WILL MAKE ITS WAY EAST THROUGH SOUTHERN
CANADA THIS WEEK BEFORE LIFTING NORTHEAST TOWARDS HUDSON BAY BY
SATURDAY. THIS NORTHEAST MOVEMENT AS THE WAVE AND ASSOCIATED
SURFACE TROUGH NEARS THE AREA HAS THE POTENTIAL TO LIMIT THE AMOUNT
OF PRECIPITATION THAT OCCURS AND IN TURN WILL LIMIT THE POPS FROM
BEING ABOVE THE CHANCE CATEGORY. AT THIS POINT...BEST CHANCE LOOKS
TO BE OVER THE WESTERN HALF OF THE U.P. WHERE THEY WILL BE ASSISTED
BY THE BETTER TIMING WITH PEAK HEATING THUNDERSTORMS OVER NORTHEAST
MINNESOTA MOVING INTO THE AREA. BEHIND THAT WAVE...AN UPPER RIDGE
AND HIGH PRESSURE WILL BUILD BACK INTO THE UPPER GREAT LAKES REGION
FOR THE END OF THE WEEKEND AND EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 150 PM EDT MON JUL 20 2015
EXPANSION OF CU/SC CLOUDS ACROSS TAF SITES INTO MID AFTN WITH CLOUDS
SCATTERING OUT BY EVENING. CONDITIONS WILL REMAIN VFR. ONLY OTHER
ISSUE TODAY WILL BE GUSTY WEST WINDS...OVER 30 KTS INTO MID AFTN AT
KCMX...AND RESULTING IN CROSSWIND AT KSAW. WINDS WILL DIMINISH THIS
EVENING AT ALL TAF SITES WITH LOSS OF DAYTIME HEATING. VFR
CONDITIONS WL CONTINUE TNGT BUT THERE MAY BE LINGERING SCT-BKN MID
CLOUDS. MORE VFR CU/SC EXPECTED ON TUESDAY. WEST WINDS COULD BE
GUSTY AGAIN WITH OVER 20 KTS POSSIBLE AT KCMX IN THE AFTN. MORE
TYPICAL LAKE BREEZE DIRECTIONS EXPECTED AT KIWD AND KSAW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 340 AM EDT MON JUL 20 2015
LOW PRESSURE FROM W ONTARIO TO JUST NW OF JAMES BAY WILL SWING INTO
S HUDSON BAY AND W QUEBEC TODAY WHILE DRAGGING A TROUGH ACROSS LAKE
SUPERIOR. WITH THE TIGHT PRESSURE GRADIENT...25KT WINDS WILL REMAIN
POSSIBLE ACROSS LAKE SUPERIOR.
A LARGE AREA OF HIGH PRESSURE FROM S CENTRAL CANADA THROUGH THE
CENTRAL PLAINS STATES TONIGHT WILL SLOWLY EDGE E...AND BUILD ACROSS
THE UPPER GREAT LAKES THROUGH THURSDAY...WITH WINDS RETURNING TO
AROUND 20KTS OR LESS. VERY PATCHY FOG /MAINLY N/ WILL ALSO DIMINISH
MONDAY. EXPECT A N PLAINS LOW THURSDAY NIGHT TO SHIFT TO N ONTARIO
BY THE END OF THE DAY FRIDAY...WITH A TROUGH PUSHING ACROSS
MINNESOTA AND W LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...JLA
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
153 PM EDT MON JUL 20 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM EDT MON JUL 20 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A WNW FLOW ALOFT
ALONG THE CNDN BORDER E OF AN UPR RDG OVER THE ROCKIES. SHRTWV AND
ASSOCIATED SFC LO EMBEDDED IN THIS FLOW ARE MOVING THRU NW
ONTARIO...WITH ATTENDANT SFC COLD FNT STRETCHING INTO MN. SOME ISOLD
SHOWERS ARE PRESENT JUST AHEAD OF THIS FNT AND MOVING THRU NW LK SUP
TOWARD THE KEWEENAW. BUT WITH AN ABSENCE OF MSTR INFLOW INTO THE
SHRTWV AND NOCTURNAL COOLING...THESE SHOWERS HAVE TENDED TO DIMINISH
WITH TIME TO THE S OF SHARPER DPVA/DEEP LYR QVECTOR CNVGC PASSING TO
THE N CLOSER TO THE SHRTWV TRACK. OTRW...STEADY WSW WINDS AHEAD OF
THE FNT ARE RESULTING IN WELL ABV NORMAL TEMPS EARLY THIS MRNG.
MAIN FCST CONCERNS IN THE SHORT TERM WL BE ON POPS TODAY ASSOCIATED
WITH APRCHG COLD FNT AS WELL AS GUSTY WINDS.
TODAY...SHRTWV MOVING THRU NW ONTARIO JUST N OF LK SUP IS FCST TO
MOVE QUICKLY ESEWD TO NEAR THE QUEBEC/ONTARIO BORDER BY 00Z THIS
EVNG. ATTENDANT COLD FNT IS PROGGED TO SWING THRU THE CWA...REACHING
THE SE ZNS ARND 18Z BEFORE CONTINUING AWAY TO THE SE IN THE AFTN.
WHILE THERE MAY BE SOME ISOLATED SHOWERS THIS MRNG OVER MAINLY THE
NRN TIER CLOSER TO THE SHRTWV TRACK/CORE OF SHARPER FORCING...EXPECT
A MAINLY DRY FROPA BECAUSE THE TIMING WL BE AHEAD OF THE FULL IMPACT
OF DAYTIME HEATING. A BIT CONCERNED THE LATER ARRIVAL EARLY THIS
AFTN OVER THE SE CWA WITH SOME ENHANCED LLVL CNVGC WITH LK BREEZE
OFF LK MI COULD RESULT IN SOME ISOLD SHOWERS/TS THERE AS HINTED AT
BY SOME OF THE HIER RES MODELS...SO DID MENTION SOME SCHC POPS IN
THIS AREA BEFORE MORE VIGOROUS DRYING AND THE ARRIVAL OF LARGER
SCALE DNVA/DEEP LYR QVECTOR DVGC ENDS THE PCPN CHCS BY LATE AFTN.
EXPECT SOME GUSTY WINDS AGAIN TODAY AHEAD OF AND FOLLOWING THE COLD
FROPA WITH H925 WSW WINDS UP TO 25-30 KTS SHIFTING TO THE WNW IN THE
AFTN. EXPECT THE HIEST MAX TEMPS INTO THE 80S OVER THE SCNTRAL. COOL
AIR ADVECTION IN THE WAKE OF THE FROPA WITH H85 TEMPS PROGGED TO
FALL TO NEAR 10C OVER THE NW CWA BY 00Z WL LIMIT THE DAYTIME DIURNAL
TEMP RISE TO THE NW.
TNGT...ANOTHER SHRTWV/SOME MID LVL MSTR ARE FCST TO SWING SE INTO
THE UPR LKS WITHIN DEEPENING UPR TROF. WHILE THERE MAY BE SOME CLDS
ACCOMPANYING THIS DISTURBANCE...NONE OF THE MODELS SHOW ANY PCPN
OVER UPR MI. WL MAINTAIN A DRY FCST DURING PERIOD OF NOCTURNAL
COOLING. OVERNGT LOWS WL BE QUITE A BIT LOWER THAN THIS MRNG WITH
SOME UPR 40S AT SOME OF THE COOL SPOTS. BUT STEADY NW WINDS WL TEND
TO LIMIT THE TEMP DROP.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 340 AM EDT MON JUL 20 2015
IMPACTS...NO SIGNIFICANT IMPACTS ARE WITHIN PREDICTABLE RANGE.
POSSIBILITY FOR STRONG TO SEVERE STORMS OVER PARTS OF THE REGION
LATE FRI INTO EARLY SAT...BUT STILL VERY UNCERTAIN ON THAT ASPECT.
MAY SEE A LIGHT SHOWER OR TWO ON TUE AFTERNOON AS A SHORTWAVE MAY
PASS THROUGH...BUT WILL LEAVE THE FORECAST DRY FOR NOW GIVEN LIMITED
COVERAGE/PRECIP AMOUNT/CONFIDENCE.
MAY SEE SHOWERS AND THUNDERSTORMS ALONG AND/OR NEAR THE WI BORDER
LATE WED INTO THU NIGHT AS MODELS SHOW A WARM FRONT MOVING INTO THE
AREA FROM THE SW ALONG WITH MOISTURE ADVECTION. WILL KEEP POPS SW OF
THE CWA ON WED...BUT WILL CONTINUE TO BRING SLIGHT CHANCE POPS INTO
AREAS ALONG THE WI BORDER WED NIGHT AND THU AS THE FRONT SLOWLY
MOVES NE. TIMING/LOCATION MAY BE CHANGED IF ANY DISTURBANCES FORM
THAT CAUSE THE FRONT/MOISTURE ADVECTION TO SURGE FARTHER N.
THE DISTURBANCE THAT THE WARM FRONT IS TIED TO WILL MOVE ACROSS
MANITOBA CANADA AND HUDSON BAY FRI INTO SUN...DRAGGING A SFC
TROUGH/COLD FRONT THROUGH THE AREA. DEFINITELY SOME DIFFERENCES
BETWEEN MODELS WITH THIS SYSTEM...WITH THE GFS BEING STRONGER AND
CONSIDERABLY FARTHER S THAN THE ECMWF. WILL USE CONSENSUS GUIDANCE
GIVEN THE UNKNOWNS INVOLVED...WHICH WILL SHOW SHOWERS AND
THUNDERSTORMS MOVING W TO E ACROSS THE CWA FROM LATE FRI THROUGH
SAT. SUN LOOKS DRY FOR NOW.
TEMPS WILL BE COOLEST TUE AND WED WITH NEAR TO SLIGHTLY BELOW NORMAL
TEMPS EXPECTED. AN UPPER RIDGE MOVES OVER THE AREA LATE IN THE WEEK
AHEAD OF THE CANADIAN DISTURBANCE...LEADING TO NEAR NORMAL TEMPS THU
AND ABOVE NORMAL TEMPS FRI THROUGH SUN. LOOKS LIKE UPPER RIDGING W
OF THE REGION IS FOR THE MOST PART HERE TO STAY THROUGH THE END OF
JULY...WITH ABOVE NORMAL TEMPS. CFS ALSO POINTS TO ABOVE NORMAL
TEMPS THROUGH MOST OF THE REST OF THE MONTH...WITH BELOW NORMAL
TEMPS TO START AUGUST OFF.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 150 PM EDT MON JUL 20 2015
EXPANSION OF CU/SC CLOUDS ACROSS TAF SITES INTO MID AFTN WITH CLOUDS
SCATTERING OUT BY EVENING. CONDITIONS WILL REMAIN VFR. ONLY OTHER
ISSUE TODAY WILL BE GUSTY WEST WINDS...OVER 30 KTS INTO MID AFTN AT
KCMX...AND RESULTING IN CROSSWIND AT KSAW. WINDS WILL DIMINISH THIS
EVENING AT ALL TAF SITES WITH LOSS OF DAYTIME HEATING. VFR
CONDITIONS WL CONTINUE TNGT BUT THERE MAY BE LINGERING SCT-BKN MID
CLOUDS. MORE VFR CU/SC EXPECTED ON TUESDAY. WEST WINDS COULD BE
GUSTY AGAIN WITH OVER 20 KTS POSSIBLE AT KCMX IN THE AFTN. MORE
TYPICAL LAKE BREEZE DIRECTIONS EXPECTED AT KIWD AND KSAW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 340 AM EDT MON JUL 20 2015
LOW PRESSURE FROM W ONTARIO TO JUST NW OF JAMES BAY WILL SWING INTO
S HUDSON BAY AND W QUEBEC TODAY WHILE DRAGGING A TROUGH ACROSS LAKE
SUPERIOR. WITH THE TIGHT PRESSURE GRADIENT...25KT WINDS WILL REMAIN
POSSIBLE ACROSS LAKE SUPERIOR.
A LARGE AREA OF HIGH PRESSURE FROM S CENTRAL CANADA THROUGH THE
CENTRAL PLAINS STATES TONIGHT WILL SLOWLY EDGE E...AND BUILD ACROSS
THE UPPER GREAT LAKES THROUGH THURSDAY...WITH WINDS RETURNING TO
AROUND 20KTS OR LESS. VERY PATCHY FOG /MAINLY N/ WILL ALSO DIMINISH
MONDAY. EXPECT A N PLAINS LOW THURSDAY NIGHT TO SHIFT TO N ONTARIO
BY THE END OF THE DAY FRIDAY...WITH A TROUGH PUSHING ACROSS
MINNESOTA AND W LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...JLA
MARINE...TITUS
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1242 PM CDT MON JUL 20 2015
.UPDATE:
ISSUED AT 1235 PM CDT MON JUL 20 2015
LET FLASH FLOOD WATCH EXPIRE AT NOON AS MAIN AREA OF RAIN HAS
MOVED OFF TO THE EAST AND DIMINISHED. COULD SEE REDEVELOPMENT THIS
AFTERNOON AHEAD OF COLD FRONT AS MCV MOVES THROUGH. OTHERWISE,
PARTLY TO MOSTLY CLOUDY SKIES WITH HIGHS IN THE MID 80S TO MID
90S. FAR SOUTHERN PORTIONS OF FORECAST AREA COULD SEE HEAT
INDICES BETWEEN 100 AND 105.
BYRD
&&
.SHORT TERM: (THROUGH LATE THIS AFTERNOON)
ISSUED AT 316 AM CDT MON JUL 20 2015
CONVECTION TRENDS ARE THE PRIMARY FOCUS FOR TODAY`S FORECAST.
LATEST SHORT RANGE GUIDANCE INCLUDING THE RAP, NAM, AND TO A
LESSER EXTENT THE HRRR SHOW THE LINE OF BACKBUILDING THUNDERSTORMS
CURRENTLY OVER SOUTH-CENTRAL MISSOURI CONTINUING AND SLOWLY MOVING
EAST-NORTHEAST THROUGH THE EARLY AND MID MORNING HOURS. THE RAP
SEEMS TO BE HANDLING THIS BEST WITH MASS FIELDS PICKING UP THE
CONVECTION PRETTY WELL AT THIS TIME. NOT SURE HOW FAR EAST-
NORTHEAST THE STORMS WILL GET THIS MORNING...BUT HEAVY RAIN OVER
OUR EASTERN OZARK COUNTIES LOOKS LIKELY SO HAVE EXPANDED THE FLASH
FLOOD WATCH ACCORDINGLY. THE AREA OF STORMS NOW MOVING INTO WEST
CENTRAL/NORTHWEST MISSOURI WILL FURTHER COMPLICATE THE FORECAST.
SHOULD SEE THAT AREA GRADUALLY DIMINISH THIS MORNING AS THE LOW
LEVEL JET WEAKENS, BUT I DON`T THINK IT WILL TOTALLY FALL APART.
SHOULD SEE REDEVELOPMENT IN THE VICINITY OF THE MCV THIS AFTERNOON
AS DIURNAL HEATING REINVIGORATES CONVECTION. COVERAGE IS
UNCERTAIN AT THIS TIME, BUT THINK AT LEAST 40-50 POPS ARE
WARRANTED THIS AFTERNOON.
SECOND CONCERN IS POTENTIAL FOR HEAT INDEX VALUES IN EXCESS OF 100
DEGREES AGAIN TODAY. THIS SEEMS LESS LIKELY THAN PREVIOUS DAYS DUE
TO EXTENSIVE CLOUD COVER FROM CONVECTIVE DEBRIS AND AFTERNOON
THUNDERSTORMS. THOUGH FORECAST HEAT INDEX VALUES COME VERY NEAR
100 DEGREES (AND I CANNOT RULE OUT THERE WON`T BE SOME 100+ DEGREE
READINGS IN A FEW PLACES THIS AFTERNOON), FEEL THERE ARE TOO MANY
FACTORS AGAINST WIDESPREAD 100+ HEAT INDEX VALUES TO ISSUE ANY
HEADLINES AT THIS TIME.
CARNEY
.LONG TERM: (TONIGHT THROUGH SUNDAY)
ISSUED AT 333 AM CDT MON JUL 20 2015
AT THE START OF THE PERIOD TONIGHT, IT LOOKS LIKE THE HIGHEST PROBS
FOR RAIN WILL BE FOR AREAS NEAR I-70 AND INTO SOUTHEAST MO WITH WHAT
SHOULD BE MUCH MORE DIURNALLY DEPENDENT SCATTERED CONVECTION FURTHER
TO THE NORTH. ANOTHER COLD FRONT WILL MOVE THRU OUR REGION THIS
EVENING AND WILL, OVER TIME, SUPPRESS THE MORE WIDESPREAD SHRA/TSRA
OVER OUR SOUTHERN FORECAST AREA TO THE SOUTH WHILE THE NORTHERN
SCATTERED CONVECTION WILL LIKELY DISSIPATE.
HIGH PRESSURE WILL THEN BE THE DOMINANT INFLUENCE OVER MOST OF OUR
REGION TUESDAY MORNING THRU WEDNESDAY AFTERNOON. ENOUGH DRY AIR IS
EXPECTED TO BUILD IN MOST AREAS TO RESULT IN DRY WX WITH NIGHTTIME
MIN TEMPS POSSIBLY CLIPPING THE 50S NORTH OF I-70 WITH LOW 60S
EXPECTED MOST ELSEWHERE. MAX TEMPS ARE EXPECTED TO BE A RELATIVELY
BENIGN LOW-MID 80S. UPPER LEVEL DISTURBANCES ARE ANTICIPATED TO
HAVE JUST ENOUGH MOISTURE TO WORK WITH AS THEY TRAVERSE ACROSS FAR
SOUTHERN MO AND SOUTHERN IL TO RESULT IN CONTINUED CHANCES FOR RAIN
THIS PERIOD.
THE OLD FRONT TO THE SOUTH IS EXPECTED TO PUSH BACK TO THE NORTH
WEDNESDAY NIGHT FOR INCREASING RAIN CHANCES AREAWIDE. AT THIS
POINT...THERE IS GOOD MODEL CONSENSUS ON AMPLIFICATION UPSTREAM TO
THE ALREADY EXISTING MID AND UPPER LEVEL NW FLOW THAT IT LOOKS
LIKE WHERE THE FRONT WINDS UP EARLY THURSDAY MAY BE WHERE IT STAYS
FOR THE REMAINDER OF THE WEEK...RESULTING IN PERSISTENT RAIN CHANCES
FOR LATE WEEK. THE OTHER SOLUTION...WHICH WAS FAVORED UNTIL
RECENTLY...WAS THE FRONT PUSHING NORTH BRIEFLY AS A WARM FRONT...BUT
THE MODELS HAVE BEEN GRADUALLY BACKING AWAY FROM THIS SCENARIO OVER
THE PAST FEW DAYS.
THE AMPLIFIED UPPER LEVEL HIGH TO OUR WEST IS THEN EXPECTED TO
PERSIST THRU THE UPCOMING WEEKEND...AND WHILE TEMPS SHOULD BOUNCE
BACK...THEIR LIKELIHOOD OF GETTING MUCH ABOVE AVERAGE IS LOOKING
SLIMMER BY THE DAY.
TES
&&
.AVIATION: (FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1235 PM CDT MON JUL 20 2015
MAIN RAIN SHIELD HAS EXITED TAF SITES, SO KEPT TAFS DRY FOR NOW.
DID KEEP VICINITY THUNDERSTORMS AT KUIN AND KCOU AS FRONT MOVES
THROUGH LATER THIS AFTERNOON. OTHERWISE, VFR CONDITIONS WITH SOUTH
WINDS VEERING TO THE WEST THEN NORTH THROUGH THE FORECAST PERIOD.
SPECIFICS FOR KSTL:
MAIN RAIN SHIELD HAS EXITED METRO AREA, SO KEPT TAF DRY FOR NOW.
MAY NEED TO ADD VICINITY THUNDERSTORMS MENTION AS FRONT MOVES
THROUGH THIS EVENING. OTHERWISE, VFR CONDITIONS WITH SOUTH WINDS
VEERING TO THE WEST BY 00Z TUESDAY THEN NORTH BY 13Z TUESDAY.
BYRD
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1207 PM CDT MON JUL 20 2015
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 316 AM CDT MON JUL 20 2015
REGIONAL RADAR MOSAIC SHOWING A COUPLE AREAS OF CONVECTION TO
CONTEND WITH THIS MORNING. FIRST IS CLUSTER OF STORMS OVER SD
PUSHING INTO THE NRN CWA ALONG A COLD FRONT THAT IS PROGGED TO
PUSH DEEPER INTO THE CNTRL PLAINS LATER TODAY. MEANWHILE A LINE OF
STORMS WAS LIFTING ACROSS KS ON NOSE OF LLVL JET/THETA-E ADV.
LATEST HRRR/RAP13 ARE IN REASONABLE AGREEMENT AREAL COVERAGE WILL
INCREASE AS ACTIVITY MERGES EARLY THIS MORNING...BUT THEN QUICKLY
DISSIPATES BY LATE MORNING WHEN THE BNDRY MOVES SOUTH OF THE CWA.
THE HRRR IS ALSO SHOWING POTENTIAL FOR POST-FRONTAL REDEVELOPMENT
ALONG THE 850MB WARM FRONT/MID LYR AGEOSTROPHIC LIFT MAINLY OVER
THE SRN CWA LATER THIS AFTN. RELATIVELY MILD CONDITIONS ON TAP
THEN THROUGH AT LEAST WED AS AS COOLER AIR MASS REMAINS IN CONTROL
OVER THE REGION. GOING FCST HAS SMALL POPS IN PLACE OVER THE SRN
CWA WED NIGHT ASSOCIATED WITH A WARM FRONT LIFTING OUT OF KS/MO.
WITH LATEST MODELS STILL SUPPORTING POSSIBLE DEVELOPMENT...SEE
LITTLE REASON TO MAKE ANY CHANGES.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 316 AM CDT MON JUL 20 2015
OVERALL THE GFS/ECM/CMC MAY BE IN AGREEMENT IN REGARDS TO LARGE
SCALE FLOW EVOLVING TO A LOW AMPLITUDE RIDGE PATTERN ENCOMPASSING
THE CONUS HEADING INTO NEXT WEEKEND...BUT CONSIDERABLE DIFFERENCES
SEEN IN REGARDS TO SFC FEATURES/FROPA. THIS BEST DEPICTED ON SAT/06Z
WITH PCPN DEVELOPMENT PER THE GFS ASSOCIATED WITH A COLD FRONT
DROPPING INTO THE CNTRL PLAINS. ECM ON THE OTHER HAND AT THAT TIME
DEVELOPS PCPN ASSOCIATED WITH A WARM FRONT LIFTING OUT OF KS. GIVEN
THAT THE EVOLVING PATTERN IS NOT ALL THAT FAVORABLE FOR PCPN
ACTIVITY...HAVE TAKEN THE LIBERTY OF REMOVING POPS FROM MOST OF THE
EXTENDED PDS EXCEPT FOR FRIDAY NIGHT LEAVING TOKEN 20S IN PLACE.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1205 PM CDT MON JUL 20 2015
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. A FEW-SCT CU ARE
EXPECTED TODAY BEHIND THE COLD FRONT WITH NORTHWEST WINDS THAT
WILL DIMINISH THIS EVENING. CLEAR SKIES ARE EXPECTED TONIGHT WITH
WINDS BECOME SOUTHEAST ON TUE MORNING.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...DEE
LONG TERM...DEE
AVIATION...
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1042 AM PDT MON JUL 20 2015
.SYNOPSIS...A DISTURBANCE STRETCHING FROM THE COAST TO THE SOUTHERN
GREAT BASIN WILL AIDE IN SHOWER AND THUNDERSTORM DEVELOPMENT TODAY
THROUGH TUESDAY. STORMS IN THIS TYPE OF ENVIRONMENT CAN PRODUCE
LOCALLY HEAVY RAIN IN A SHORT PERIOD OF TIME AND RESULT IN FLASH
FLOODING. ANYONE PLANNING OUTDOOR ACTIVITIES OR A TRIP IN THE NEXT
COUPLE OF DAYS ARE ENCOURAGED TO REMAIN WEATHER AWARE. BY MID
WEEK...DRIER AIR IS EXPECTED TO SPREAD ACROSS THE REGION BRINGING AN
END TO THUNDERSTORM ACTIVITY THAT WILL LAST INTO THE WEEKEND.
&&
.UPDATE...THICK CLOUD COVER IS HOLDING DOWN TEMPS SIGNIFICANTLY
ACROSS MUCH OF THE AREA ESPECIALLY NORTH OF INTERSTATE 15. AS A
RESULT, I LOWERED HIGH TEMPS IN THIS AREA ANYWHERE BETWEEN 3 AND 8
DEGREES ON AVERAGE. FURTHER SOUTH THE CLOUD SHIELD HAS ERODED AS
DRIER AIR ALOFT HAS WORKED IN AND HIGH TEMPS LOOK MUCH MORE
ACHIEVABLE HERE. UPDATED GRIDS AND ASSOCIATED PRODUCTS HAVE BEEN
SENT OUT.
&&
.PREVIOUS UPDATE...ISSUED AT 749 AM PDT MON JUL 20 105
WATER VAPOR SHOWS THE CENTER OF THE MID/UPPER LEVEL LOW SWIRLING OFF
THE COAST OF CALIFORNIA THIS MORNING WEST OF POINT CONCEPTION.
MEANWHILE ACROSS SOUTHEAST CALIFORNIA THE MID-LEVEL WAVE AND
ASSOCIATED PV MAX THAT HELPED TO TRIGGER THE OVERNIGHT CONVECTION
WAS LIFTING NORTH TOWARD THE NEVADA BORDER. DRIER AIR WAS ALREADY
EVIDENT WORKING ON NORTH.
OVERALL POPS WERE ADJUSTED UP ACROSS MUCH OF LINCOLN, SOUTHERN NYE
AND NORTHERN MOHAVE COUNTIES FOR THE REST OF THIS MORNING BASED ON
THE LATEST RADAR RETURNS. POPS WERE ALSO BUMPED UP ACROSS THE
NORTHWEST CWFA FOR THIS AFTERNOON AND EVENING BASED ON THE HRRR AND
WRF AS THIS AREA SHOULD GET MORE ACTIVE GIVEN THE FEATURES PRESENT
TO PROVIDE FORCING (APPROACHING JET STREAK, LOW OFFSHORE, WAVE
RIDING NORTH). SOME ADJUSTMENTS WERE ALSO MADE FOR TUESDAY TO BETTER
MATCH THE NEIGHBORING WFO`S AND GIVEN WE HAVE A FLASH FLOOD WATCH
OUT.
THE REST OF THE FORECAST LOOKS IN GOOD SHAPE AT THIS TIME.
&&
.AVIATION...FOR MCCARRAN...CLOUD BASES WILL REMAIN BETWEEN 6 AND 11K
FEET THROUGH EARLY THIS EVENING. A FEW SHRA AND POSSIBLY A TSRA THIS
MORNING THOUGH IT APPEARS ANY HEAVIER TSRA ACTIVITY WOULD HOLD OFF
UNTIL LATER THIS AFTERNOON OR EARLY THIS EVENING THAT WOULD DIRECTLY
IMPACT THE AIRPORT COMPLEX. AWAY FROM ANY SHRA/TSRA OR OUTFLOW
BOUNDARIES WINDS WILL MAINLY FAVOR DIURNAL DIRECTIONAL TRENDS
THROUGH TONIGHT. SHOWERS AND THUNDERSTORMS WILL MOST PREVALENT IN
THE BEATTY AND MORMON MESA CORRIDORS WITH ISOLATED SHRA/TSRA IN THE
OTHER APPROACH CORRIDORS.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA AND SOUTHEAST
CALIFORNIA...SHRA/TSRA ACTIVITY WILL SHIFT SLOWLY NORTH TODAY WITH
DRIER CONDITIONS EXPECTED SOUTH OF INTERSTATE 40 BY THIS AFTERNOON.
OUTSIDE OF THUNDERSTORM OUTFLOW, WINDS WILL GENERALLY FOLLOW DIURNAL
DIRECTIONAL TRENDS THROUGH TONIGHT. BASES WILL MAINLY BE BETWEEN 7K
AND 12K FEET LOWERING TO BETWEEN 4K AND 6K FEET NEAR ANY SHRA/TSRA.
&&
.PREVIOUS DISCUSSION...
ISSUED AT 244 AM PDT MON JUL 20 2015
.SHORT TERM...THROUGH WEDNESDAY NIGHT.
TODAY COULD BE AN INTERESTING DAY ACROSS MUCH OF THE AREA,
ESPECIALLY NORTH OF INTERSTATE 40 WITH VARIOUS BOUNDARIES FROM
PREVIOUS DAY CONVECTION PROVIDING FOCUS FOR STORM INITIATION. IN
ADDITION, THE REMNANTS OF DOLORES IS FORECAST TO COMBINE WITH LOW
PRESSURE OFF THE WEST COAST WITH A 50KT JET FORECAST TO DEVELOP
AROUND THE BASE OF THE LOW AND MOVE INTO SOUTHERN CALIFORNIA
BECOMING AN EXTRA SOURCE OF LIFT. MODELS FORECAST DRIER, MORE STABLE
AIR OVER SOUTHERN MOHAVE INTO SOUTHEAST SAN BERNARDINO COUNTY
HEADING INTO THE AFTERNOON HOURS TODAY AND SHOWER ACTIVITY MAY SHUT
DOWN EARLY THERE. A FLASH FLOOD WATCH REMAINS FOR MOST AREAS THROUGH
MID DAY THEN THE SOUTHERN AREAS GET TRIMMED OUT AS THE DRIER AIR
MOVES INTO THE DESERTS FOR THIS AFTERNOON.
THE LOW OFF THE COAST OPENS UP TONIGHT AND CROSSES THE AREA TUESDAY
WITH THE FOCUS FOR SHOWERS/STORMS SHIFTING MAINLY TO INYO COUNTY AND
THE SOUTHERN GREAT BASIN. WEAK INSTABILITY EXTENDS INTO PORTIONS OF
CLARK COUNTY ON TUESDAY AND THE MOUNTAINS COULD SEE A FEW SHOWERS AS
WELL.
BY WEDNESDAY, TROUGHING MOVES TO THE NORTHWEST COAST AND THE
NORTHWEST CWA LIES IN THE RIGHT ENTRANCE REGION OF A 70+ KNOT JET
PROVIDING SOME UPPER LEVEL SUPPORT FOR LINGERING MOISTURE IN THAT
AREA FOR ANOTHER SHOT AT THUNDERSTORMS. DRIER, MORE STABLE AIR WILL
BE IN PLACE ELSEWHERE AND MAINLY DRY CONDITIONS ARE EXPECTED. A
WARMING TREND IS FORECAST THROUGH MID WEEK BUT TEMPERATURES WILL
REMAIN BELOW NORMAL.
.LONG TERM...THURSDAY THROUGH SUNDAY.
LONG TERM STARTS OUT WITH A TROUGH EXTENDING FROM THE THE PAC NW
SOUTHWARD INTO NORTHERN CALIFORNIA. MODELS STILL TRYING TO DEVELOP A
CONVERGENCE ZONE FROM NEAR BISHOP NORTHEAST INTO CENTRAL NEVADA
THURSDAY. ADDED SLIGHTLY HIGHER POPS TO NORTHERN ESMERALDA COUNTY AS
AN ISOLATED SHOWER OR THUNDERSTORM COULD DEVELOP. OTHERWISE, DRIER
SOUTHWEST FLOW WILL TRANSLATE TO A BREEZY AFTERNOON ALONG WITH
WARMER TEMPERATURES.
FRIDAY AND SATURDAY WILL BE DRY AND WARMER YET WITH TEMPERATURES
NEAR SEASONAL NORMALS. FOR SUNDAY...INCREASED POPS ACROSS EASTERN
MOHAVE AS MONSOON MOISTURE COULD SNEAK BACK WEST INTO THE COUNTY.
REMAINDER OF THE AREA LOOKS TO STAY DRY WITH SEASONABLE
TEMPERATURES.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION MAY BE NEEDED
TODAY AND/OR TUESDAY. REPORTS OF FLASH FLOODING, THUNDERSTORM WINDS,
DUST, HAIL AND RELATED DAMAGE AS WELL AS RAINFALL TOTALS ARE
ENCOURAGED. SPOTTER ACTIVATION IS NOT EXPECTED BEYOND WEDNESDAY
THROUGH NEXT WEEKEND.
&&
$$
UPDATE/AVIATION...STACHELSKI
PREVIOUS...SALMEN/PIERCE
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
258 PM EDT MON JUL 20 2015
.SYNOPSIS...
OPPRESSIVE HEAT WILL CONTINUE THROUGH TUESDAY. WEDNESDAY A COLD
FRONT WILL DROP INTO THE AREA AND LESSEN THE HEAT WHILE INCREASING
THUNDERSTORM CHANCES. THIS BOUNDARY WILL SLOWLY SLIP OFF TO THE
SOUTH ON FRIDAY. COOLER AND DRIER HIGH PRESSURE WILL BUILD IN FROM
THE NORTHWEST FOR THE WEEKEND AND START OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM MONDAY...PREVIOUS UPDATES TO THE CURRENT FCST STILL
LOOKS AOK THRU THIS EVENING. WIDELY SCATTERED WEAK CONVECTIVE
ACTIVITY IN THE VICINITY OF THE PIEDMONT TROF HAS DEVELOPED AND IS
IN LINE WITH THE EARLIER HRRR PROGGED REFLECTIVITY DISPLAY.
THIS UPDATE IS CONCERNED WITH TWEAKS WITH TONIGHTS LOWS. VARIOUS
MODEL GUIDANCE FOR TONIGHT LOWS HAVE INCREASED BY A DEGREE OR 3 FROM
PREVIOUS RUNS AND THEREFORE HAVE UPDATED THE LOWS TO THE 76-81
DEGREE RANGE...WITH THE LOW 80S ALONG THE IMMEDIATE COAST WHERE
LOCAL SSTS ARE IN THE 80S. THIN/OPAQUE CLOUDS WILL BECOME MAINLY
THIN THIS EVENING AND OVERNIGHT. ACTIVE WINDS IN THE 5 MPH
INLAND...5 TO 10 MPH ALONG THE COAST SHOULD KEEP FOG AT BAY.
PREVIOUS..........................................................
AS OF 1145 AM MONDAY...TWEAKED AFTN/EVENING WINDS ACROSS THE
FA...MAINLY CLOSER TO THE COAST WITH RESPECT TO THE SEA BREEZE AND
ITS FORWARD AND LIMITED INLAND PROGRESSION. HAVE CONTINUED WITH
GUSTS AOA 20 MPH ALONG THE IMMEDIATE COAST LATER THIS AFTN AND
EVENING TO ACCOUNT FOR THE STRENGTH OF TODAYS SEA BREEZE. IN
ADDITION...FURTHER LIMITED AFTN AND EVENING CLOUD COVERAGE BASED ON
LATEST SATELLITE VIS TRENDS AND LESS COVERAGE OF CONVECTION UPSTREAM
AND ACROSS THE FA WHICH IN TURN WILL LIMIT CONVECTIVE DEBRIS
CLOUDINESS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...PROGRESSIVE MID LEVEL PATTERN DEVELOPING DURING
THE PERIOD WILL PUSH A WEAK COLD FRONT INTO THE AREA LATE TUE NIGHT.
FRONT STALLS ON WED AS THE BOUNDARY ENDS UP LAYING PARALLEL TO THE
STEERING FLOW. DEEP MOISTURE WILL BE PRESENT THROUGH THE PERIOD WITH
PRECIPITABLE WATER VALUES RUNNING RIGHT AROUND 2 INCHES. AHEAD OF
THE FRONT ON TUE THE PIEDMONT TROUGH AND SEA BREEZE WILL BE THE
FOCAL POINT FOR DEEPER CONVECTION. COVERAGE ON TUE IS LIKELY TO BE
SOMEWHAT LIMITED AS THERE WILL STILL BE SOME WEAK MID LEVEL
SUBSIDENCE ASSOCIATED WITH THE RETREATING 5H RIDGE CENTERED OVER TX.
INHERITED LOW CHC POP MESHES WELL WITH VARIOUS GUIDANCE FOR TUE SO
PLAN ONLY MINOR TWEAKS.
COMBINATION OF LOW LEVEL SOUTHWEST FLOW...INCREASING IN THE
AFTERNOON...AND WEAK MID LEVEL SUBSIDENCE WILL ONCE AGAIN RESULT IN
HIGHS ABOVE CLIMO. TEMPS IN THE MID TO UPPER 90S AND ABUNDANT
MOISTURE WILL AGAIN PUSH HEAT INDEX VALUES OVER 105 DEGREES...WITH
SOME INLAND AREAS EXCEEDING 110 DEGREES. HAVE ISSUED A HEAT ADVISORY
FOR THE COAST AND COLUMBUS COUNTY WITH AN EXCESSIVE HEAT WARNING IN
EFFECT FOR THE REMAINING INLAND COUNTIES.
FRONT STALLS JUST SOUTH OF THE AREA WED MORNING THEN LIFTS BACK
NORTH AS THE SEA BREEZE DEVELOPS. SURFACE BOUNDARY WILL WILL BECOME
DIFFICULT TO DISTINGUISH AS THE SEA BREEZE BECOMES MORE DOMINANT.
WEST TO NORTHWEST FLOW WILL EXIST FROM NEAR THE SURFACE THROUGH AT
LEAST 200 MB. ALTHOUGH PRECIPITABLE WATER VALUES REMAIN ELEVATED THE
FLAT MID LEVEL FLOW AND LACK OF ANY STRONG TRIGGERING MECHANISMS
WILL LIMIT COVERAGE OF CONVECTION TO ABOUT 30 PERCENT. TEMPERATURES
ARE AGAIN EXPECTED TO BE ABOVE CLIMO...WARMEST ACROSS SOUTHERN SC
COUNTIES WHERE A HEAT ADVISORY MAY ONCE AGAIN BE NEEDED.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...MODELS CONTINUE TO SHOW LINGERING BOUNDARY AS
NW FLOW FLATTENS OUT ON BOTTOM OF MID TO UPPER TROUGH OVER THE
CAROLINAS. PCP WATER FIELDS SHOW BOUNDARY NICELY WITH VALUES DOWN
BELOW 1.5 IN DRIER AIR TO THE NORTH HEADING INTO THURS MORNING AND
HIGHER VALUES UP TO 2 INCHES TO THE SOUTH OVER SC. BUT BOUNDARY
MAY BUCKLE UP AS WIND FIELDS SHOW A WEAK SFC LOW DEVELOPING OVER
INLAND CAPE FEAR REGION. THIS WILL ALLOW A MORE EASTERLY FETCH TO
CARRY MORE MOISTURE RICH AIR BACK INTO THE AREA ON THURS. THIS
SHOULD ALSO PRODUCE A FOCAL POINT FOR CONVECTION AS SEA BREEZE
ENHANCES CONVERGENCE AS A SHORTWAVE RIDES ALONG THE BASE OF THE
TROUGH INTO THE COASTAL CAROLINAS. MODELS SUGGESTING LIKELY POPS
ON THURS. FOR NOW...HAVE PUSHED THE POPS UP TO HIGH CHC BUT WILL
WAIT FOR ANOTHER MODEL RUN TO JUMP UP ANY FURTHER. WILL KEEP WITH
TREND OF GREATEST CHC OF CONVECTION SHIFTING SOUTH INTO SC ON
THURS INTO FRI AS BOUNDARY LINGERS NEARBY.
ONCE THIS SHORTWAVE AND LOW MOVES OUT OFF TO THE EAST ON
FRI...PLENTY OF DRY AIR AND SUBSIDENCE WILL WORK ITS WAY DOWN FROM
THE NORTH IN DEEP N-NW FLOW AS HIGH PRESSURE BUILDS DOWN AT THE SFC.
BY FRI AFTN ANY MOISTURE SHOULD BE DISPLACED WELL SOUTH AND EAST OF
LOCAL AREA LEAVING PCP WATER VALUES DOWN LESS THAN 1.5 INCHES
THROUGH MUCH OF THE WEEKEND.
POSSIBLE NW FLOW CONVECTIVE DEBRIS CLOUDS OR A LITTLE SHORTWAVE
ENERGY LATE SUN INTO MON COULD BRING IN SOME CLOUD OR POSSIBLY
PRODUCE A LOCALIZED SHWR BY SUN. FOR NOW...ONLY KEEPING LOW END
SLIGHT CHC OF LOCALIZED BUILDUP ALONG SEA BREEZE OVER THE
WEEKEND...MAINLY JUST INLAND OF COAST. BY SUN NIGHT INTO MONDAY...
A MORE TYPICAL SUMMERTIME PATTERN SETS UP ONCE AGAIN WITH POSSIBLE
SHORTWAVE OR WEAK FRONT ENHANCING SOME CONVECTION UP STREAM AND
POSSIBLY ALONG PIEDMONT TROUGH INLAND.
OVERALL...AFTER EARLY FRI...HEADING INTO DRIER AND SEASONABLE
WEATHER WITH TEMPS CLOSE TO NORMAL.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 18Z...EXPECT VFR THRUOUT THE FORECAST PERIOD.
EXPECT VFR TO PREVAIL THIS AFTERNOON WITH DIURNAL CU AND HIGH CLOUDS
AS WELL. WOULD NOT ENTIRELY RULE OUT AN ISOLATED TSRA LATE THIS
AFTERNOON THROUGH MID-EVENING...THOUGH GIVEN LOW CONFIDENCE HAVE
ONLY INTRODUCED VCTS AT THE INLAND TERMINALS. COULD SEE DEBRIS
CONVECTIVE CLOUDS OVERNIGHT BUT FOR NOW HAVE LIMITED THEIR
OCCURRENCE TO BETWEEN 15K-25K FEET. ACROSS THE COASTAL TERMS...AN
ACTIVE SEA BREEZE WILL RESULT IN SSE-SSW WINDS 10-15 KT WITH GUSTS
AROUND 20 KT THRU MID- LATE EVENING...EVENTUALLY SUBSIDING LATE
EVENING AND OVERNIGHT HOURS. WINDS TO STAY ACTIVE OVERNIGHT...EVEN
ACROSS INLAND TERMINALS...AND THUS HAVE KEPT FOG OFF THE BOOKS.
AFTER DAYBREAK ON TUESDAY...EXPECT VFR WITH WSW WINDS 5 TO 10 KTS
WITH THIN CI/CS.
EXTENDED OUTLOOK...BRIEF MVFR POSSIBLE THROUGH THE PERIOD FROM
DIURNAL CONVECTION. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM MONDAY...UPDATED WINDS AND SIGNIFICANT SEAS FROM
EARLIER STILL LOOKING AOK THROUGH DAYBREAK TUESDAY. NO ADDITIONAL
CHANGES NEEDED AT THIS TIME.
PREVIOUS...........................................................
AS OF 1145 AM MONDAY...TWEAKED WINDS...MAINLY WIND SPEEDS SLIGHTLY
HIER BY UP TO SEVERAL KNOTS ACROSS THE AREA WATERS FOR THE OVERNIGHT
PERIOD. IN ESSENCE...THIS WILL RESULT IN THE WIND SPEEDS IN THE 15
TO OCCASIONALLY 20 KT RANGE FOR THE MAJORITY OF THE TONIGHT PERIOD.
THIS WILL RESULT IN SIGNIFICANT SEAS BUILDING TO 3 TO 5 FT TONIGHT.
THE PROBLEM IS WHETHER THE COMBINED 15-20 KT WINDS AND 3-5 FT
SIGNIFICANT SEAS LAST LONG ENOUGH TO WARRANT A SMALL CRAFT EXERCISE
CAUTION FLAG. THIS WILL BE DETERMINED AT THE NEXT UPDATE.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...BERMUDA HIGH AND PIEDMONT TROUGH WILL MAINTAIN
SOUTHWEST FLOW ACROSS THE WATERS TUE INTO TUE NIGHT. GRADIENT WILL
BECOME A LITTLE MORE DEFINED LATER TUE AND TUE NIGHT WITH SPEEDS
HITTING A SOLID 20 KT AT TIMES. SEAS TUE AND TUE NIGHT MAY FLIRT
WITH 5 FT NEAR THE 20 NM LIMIT BUT THE BULK OF THE ZONES WILL BE 3
TO 4 FT WITH SOME 2 FT NEAR SHORE. WEAK FRONT SETTLES OVER THE AREA
LATE TUE...PUSHING JUST SOUTH OF THE AREA BY DAYBREAK WED. FRONT
WILL BE OBSCURED WED BY DEVELOPING SEA BREEZE...WHICH WILL RESULT IN
SOUTHERLY FLOW RETURNING TO THE WATERS. GRADIENT WEAKENS FOR WED
WITH SPEEDS 10 TO 15 KT. SEAS WILL DROP TO 2 TO 4 FT LATE TUE NIGHT
AND REMAIN UNCHANGED THROUGH THE END OF THE PERIOD.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 PM MONDAY...LINGERING FRONTAL BOUNDARY MAY PRODUCE MORE
VARIABLE WINDS ON THURS...BUT REMAINING VERY LIGHT OVERALL. SOME
MODELS HINT AT A BROAD WEAK SFC LOW DEVELOPING ON THURS BUT EITHER
WAY A MORE ON SHORE FLOW LESS THAN 10 KTS THURS BECOMING MORE
NORTHERLY ON FRI UP TO 10 TO 15 KTS INTO THE WEEKEND AS HIGH
PRESSURE BUILDS DOWN FROM THE NORTH. SEAS WILL BASICALLY REMAIN
BETWEEN 2 AND 4 FT THROUGH THE PERIOD. EXPECT A SLIGHT UPTICK IN
WINDS AND SEAS EACH AFTN AS SEA BREEZE DEVELOPS NEAR SHORE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...EXCESSIVE HEAT WARNING FROM NOON TO 7 PM EDT TUESDAY FOR
SCZ017-023-024-032-033-039.
HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR SCZ017-023-024-
032-033-039-053>056.
HEAT ADVISORY FROM NOON TO 7 PM EDT TUESDAY FOR SCZ053>056.
NC...EXCESSIVE HEAT WARNING FROM NOON TO 7 PM EDT TUESDAY FOR
NCZ087-096.
HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR NCZ087-096-099-
105>110.
HEAT ADVISORY FROM NOON TO 7 PM EDT TUESDAY FOR NCZ099-105>110.
MARINE...NONE.
&&
$$
NEAR TERM...DCH
SHORT TERM...III
LONG TERM...RGZ
AVIATION...DCH/SGL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
130 PM EDT MON JUL 20 2015
.SYNOPSIS...A RELATIVELY ACTIVE SUMMER PATTERN...NORTHWEST FLOW
ALOFT...WILL PREVAIL ACROSS THE REGION THROUGH THE WEEK AS AN UPPER
LEVEL RIDGE STRENGTHENS OVER THE CENTRAL PLAINS.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 1100 AM MONDAY...
...HEAT ADVISORY REMAINS IN EFFECT THIS AFTERNOON...
LATE MORNING UPDATE WILL MAINLY SLOW DOWN THE MIXING TRENDS THIS
AFTERNOON...WHICH WILL STILL RESULT IN MARGINAL HEAT INDICES TO
SUPPORT THE ONGOING ADVISORY.
PREVIOUS DISCUSSION... CENTRAL NC REMAINS ON THE EAST NORTHEAST
PERIPHERY OF AN UPPER LEVEL RIDGE CENTERED OVER THE SOUTH-CENTRAL
CONUS - AT THE SOUTHERN FRINGE OF THE WESTERLIES IN WNW FLOW ALOFT.
IN SUCH A PATTERN...A VARIETY OF ADDITIONAL VARIABLES CAN INFLUENCE
THE DEVELOPMENT/EVOLUTION (OR LACK THEREOF) OF
CONVECTION...INCLUDING UPSTREAM CONVECTION OR THE REMNANTS THEREOF
(MCV`S/OUTFLOW BOUNDARIES)...SMALL AMPLITUDE BAROCLINIC WAVES AT THE
SOUTHERN FRINGE OF THE WESTERLIES...LOW-LEVEL MOISTURE
ADVECTION...DEPTH/DEGREE OF MIXING...ETC. AS A RESULT...CONFIDENCE
IN CONVECTIVE CHANCES/COVERAGE/TIMING THIS AFTERNOON AND EVENING IS
BELOW AVERAGE.
H85 TEMPS OF 18-20C AND STRONG INSOLATION/MIXING CONTINUE TO SUGGEST
HIGHS IN THE MID/UPPER 90S THIS AFTERNOON. HOWEVER...CONFIDENCE IN
SFC DEWPOINTS...RELATIVE HUMIDITY AND HEAT INDICES REMAINS
UNCERTAIN. LOW-LEVEL THERMODYNAMIC PROFILES FCST BY THE GFS/NAM ARE
CONSIDERABLY DIFFERENT FOR THIS AFTERNOON. THE NAM SUGGESTS 16-18C
H85 DEWPOINTS OVER CENTRAL NC...WITH SFC DEWPOINTS RANGING FROM THE
MID 60S (NW) TO ~70F (E/SE). AS A RESULT...THE NAM SUGGESTS MODERATE
DESTABILIZATION AND HEAT INDICES AT/AROUND ADVISORY CRITERIA SOUTH
AND EAST OF THE TRIANGLE. THE GFS INDICATES H85 DEWPOINTS ~14C...
DEEPER MIXING...SFC DEWPOINTS IN THE LOWER 60S...MARGINAL
INSTABILITY LARGELY CONFINED TO THE WEST/NW PIEDMONT...AND LOWER
HEAT INDICES OF 100-103F SOUTH AND EAST OF THE TRIANGLE. SPC
MESOANALYSIS DATA INDICATES A DRY LOW-LEVEL AIRMASS IN PLACE OVER
CENTRAL NC EARLY THIS MORNING WITH H85 DEWPOINTS OF 12-15C (16-17C
ALONG THE COAST AND ALONG/WEST OF THE MOUNTAINS). THOUGH WEAK
WESTERLY FLOW SHOULD ALLOW BETTER LOW-LEVEL MOISTURE TO ADVECT INTO
PORTIONS OF THE WEST/SW PIEDMONT THIS AFTERNOON...THE AFOREMENTIONED
MESOANALYSIS DATA SUGGESTS THERMODYNAMIC PROFILES WILL BE CLOSER TO
THOSE DEPICTED BY THE GFS THAN THE NAM.
TWO SMALL AMPLITUDE WAVES (BAROCLINIC/MCV/OR A COMBINATION THEREOF)
WERE LOCATED UPSTREAM OF THE AREA THIS MORNING...ONE IN WV AND THE
OTHER ALONG THE WESTERN TN/KY BORDER. THE LATEST RAP GUIDANCE
SUGGESTS THE WAVE IN WV WILL TRACK EASTWARD THROUGH CENTRAL/
NORTHERN VA LATE THIS MORNING AND EARLY THIS AFTERNOON...WHILE THE
KY/TN WAVE TAKES A MORE UNCERTAIN COURSE (INTO A WEAKER FLOW REGIME)
EAST SOUTHEAST ACROSS SOUTHWEST NC AND UPSTATE SC LATE THIS
AFTERNOON. THE LATTER WAVE TRACKING INTO WESTERN NC/SC APPEARS MOST
LIKELY TO AID CONVECTIVE DEVELOPMENT THIS AFT/EVE GIVEN EXCELLENT
DIURNAL TIMING AND A TRACK WHICH TAKES IS THROUGH A MORE FAVORABLE
THERMODYNAMIC ENVIRONMENT. GIVEN UNCERTAINTY IN THERMODYNAMIC
PROFILES (AS MENTIONED ABOVE)...UNCERTAINTY IN THE PRECISE
TRACK/TIMING OF THE AFOREMENTIONED WAVES IN ADDITION TO THE
POTENTIAL CONTRIBUTION FROM MESOSCALE FORCING...WILL INDICATE A 20-
30% CHANCE OF CONVECTION...HIGHEST IN THE WEST/SW PIEDMONT AND FAR
NE COASTAL PLAIN. -VINCENT
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 430 AM MONDAY...
...HEAT ADVISORY WILL LIKELY BE NEEDED FOR PORTIONS OF CENTRAL NC...
FORECAST CHALLENGES WILL BE SIMILAR TO TODAY...ALBEIT WITH A BETTER
OVERALL POTENTIAL FOR CONVECTION AS THE WESTERLIES STRENGTHEN
/EXTEND FURTHER SOUTH/ IN RESPONSE TO AMPLIFICATION OF AN UPPER
LEVEL TROUGH OVER PORTIONS OF EASTERN CANADA...THE GREAT LAKES...AND
NEW ENGLAND. LATEST GUIDANCE SUGGESTS DRY CONDITIONS FOR MOST OF THE
DAY...WITH A RAPID INCREASE IN CONVECTIVE POTENTIAL AFTER 21Z AND
THE BEST OVERALL POTENTIAL BETWEEN LATE AFTERNOON AND MIDNIGHT (21-
04Z). EXPECT HIGHS SIMILAR TO TODAY...ALBEIT SLIGHTLY COOLER IN THE
FAR NW PIEDMONT. ANOTHER HEAT ADVISORY WILL LIKELY BE NEEDED...
PERHAPS ALONG/EAST OF THE HWY 1 CORRIDOR (I.E. INCLUDING THE
TRIANGLE)...DEPENDING ON LOW-LEVEL MOISTURE. -VINCENT
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 320 AM MONDAY...
MEDIUM RANGE MODELS ARE IN GENERAL AGREEMENT IN SHOWING A SURFACE
FRONT STALLING NEAR OR JUST TO THE SOUTH OF CENTRAL NC FROM MID TO
LATE WEEK... BEFORE SHIFTING FURTHER SOUTH OVER THE WEEKEND AS A
SURFACE HIGH BUILDS MORE AGGRESSIVELY IN FROM THE NORTH (AS IT
SHIFTS EASTWARD AND EVENTUALLY OFFSHORE) WHILE THE MID LEVEL TROUGH
AXIS OVER THE NORTHEAST PUSHES OFFSHORE. THIS SHOULD ALLOW FOR
MAINLY DIURNAL CHANCES FOR SHOWERS AND STORMS FROM MID TO LATE
WEEK... MAINLY ACROSS SOUTHERN PORTIONS OF THE AREA...INVOF THE
FRONT... WITH GENERALLY DRY WEATHER RETURNING FOR THE WEEKEND (SMALL
CHANCE OF CONVECTION ON SUNDAY... DEPENDING ON THE TIMING OF ANOTHER
NORTHERN STREAM S/W TRACKING ACROSS THE NORTHERN HALF OF THE
COUNTRY).
HIGH TEMPS DURING THE MEDIUM RANGE SHOULD BE NEAR NORMAL... WITH
HIGHS IN THE UPPER 80S TO LOWER 90S. LOW TEMPS WILL FOLLOW A SIMILAR
TREND... GENERALLY UPPER 60S NORTH TO LOWER 70S SOUTH.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 130 PM MONDAY...
24-HR TAF PERIOD: EXPECT VFR CONDITIONS TO PREVAIL THROUGH THE TAF
PERIOD...ASIDE FROM A SMALL POTENTIAL FOR SHOWERS/STORMS LATE THIS
AFT/EVE...PRIMARILY AT THE INT/GSO TERMINALS...THOUGH POSSIBLY AT
ANY TERMINAL. GENERALLY WESTERLY WINDS ~10 KT THIS AFTERNOON WILL
BECOME LIGHT AFTER SUNSET.
LONG TERM: TYPICAL SUMMERY PATTERN FEATURING DIURNAL CONVECTION WILL
CONTINUE INTO THE WEEKEND WITH AN UPPER RIDGE PERSISTING OVER THE
CENTRAL CONUS PRODUCING NORTHWEST FLOW ALOFT DOWNSTREAM ACROSS THE
APPALACHIANS AND MID-ATLANTIC. THE PRIMARY AVIATION HAZARD WILL BE
LATE DAY CONVECTION...GENERALLY 18-02Z...ALTHOUGH NOCTURNAL ACTIVITY
WILL BE A POSSIBILITY IF WE HAVE STRONG DOWNSTREAM CONVECTION THAT
MOVES INTO THE AREA OVERNIGHT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM 1 PM TO 7 PM EDT MONDAY FOR NCZ011-027-028-042-
043-077-078-085-086-088-089.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...MLM/VINCENT
SHORT TERM...VINCENT
LONG TERM...77
AVIATION...MLM
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
406 PM EDT MON JUL 20 2015
.SYNOPSIS...
A WEAK SHORTWAVE WILL MOVE EAST THROUGH THE OHIO VALLEY
TODAY...BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS...MAINLY
NEAR AND SOUTH OF THE OHIO RIVER. A COLD FRONT WILL MOVE SOUTHEAST
THROUGH THE REGION ON TUESDAY...WITH DRIER AND SLIGHTLY COOLER
CONDITIONS EXPECTED THROUGH THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
THE AIR MASS OVER THE OHIO VALLEY REMAINS WARM AND MOIST...THOUGH
NOT QUITE TO THE EXTENT THAT IT WAS OVER THE WEEKEND. DEWPOINTS
ARE IN THE UPPER 60S TO MID 70...BUT SURFACE TEMPERATURES ARE
GENERALLY IN THE MID 80S...RATHER THAN PUSHING TOWARD 90 DEGREES.
THERE HAVE BEEN SEVERAL LAYERS OF CLOUDS HELPING TO SLIGHTLY
INHIBIT HEATING...WITH THICK LAYERS OF CUMULUS (2500-4000 FEET)
AND SOME HIGH CLOUDS MOVING IN THE WESTERLY FLOW ALOFT.
SPC MESOANALYSIS INDICATES THAT THE SOUTHERN HALF OF THE FORECAST
AREA HAS BEEN ABLE TO DEVELOP ABOUT 1500 J/KG OF MLCAPE. A WEAK
MID-LEVEL WAVE IS FORECAST TO MOVE EAST THROUGH THE REGION THIS
EVENING...AND THERE ARE SIGNS OF A WEAK VORTICITY CENTER OVER
SOUTHEASTERN ILLINOIS...MOVING INTO INDIANA AS OF ABOUT 19Z.
SHOWER AND THUNDERSTORM DEVELOPMENT IS EXPECTED TO BEGIN DURING
THE NEXT FEW HOURS...MAINLY IMPACTING THE SOUTHERN HALF OF THE
FORECAST AREA BETWEEN 22Z-04Z. THERE APPEARS TO BE JUST ENOUGH
DEEP-LAYER SHEAR AND INSTABILITY TO SUPPORT A RISK FOR A FEW
STRONG STORMS...THOUGH NONE OF THE HIGH-RES GUIDANCE (12Z SPC-WRF
OR RECENT HRRR RUNS) INDICATE THAT DEVELOPMENT WILL BE
PARTICULARLY EXPLOSIVE. WITH WEAK FORCING THAT TIMES OUT A LITTLE
TOO LATE FOR THE PEAK OF THE DIURNAL CYCLE...THE SEVERE THREAT
APPEARS LIMITED.
PRECIPITATION POTENTIAL WILL DIMINISH DURING THE SECOND HALF OF
THE OVERNIGHT...AS THE SHORTWAVE MOVES AWAY...AND THE DIURNAL
CYCLE HEADS TOWARD ITS LOWER END. HOWEVER...THE AIR MASS WILL NOT
YET BE CHANGING SIGNIFICANTLY...AS THE APPROACHING COLD FRONT WILL
STILL BE NORTH OF THE FORECAST AREA. THUS...ANOTHER ROUND OF
FAIRLY WARM MIN TEMPS CAN BE EXPECTED...WITH LOWER 70S IN THE
SOUTH AND UPPER 60S IN THE NORTH.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
ON TUESDAY MORNING...A COLD FRONT WILL BE MOVING ACROSS THE
MICHIGAN BORDER...CONTINUING ITS SOUTHEASTWARD TREK INTO INDIANA
AND OHIO. THIS FRONT DELINEATES THE LEADING EDGE OF A SLIGHTLY
COOLER AND SIGNIFICANTLY DRIER AIR MASS...WHICH WILL BE MOVING
INTO THE OHIO VALLEY FOR THE MIDDLE OF THE WEEK.
TUESDAY WILL STILL BE A TRANSITION DAY FOR THE REGION...THOUGH
PREVAILING DRY CONDITIONS ARE LIKELY FOR MOST OF THE FORECAST
AREA. FORCING ALONG THE FRONT IS NOT PARTICULARLY STRONG...AND
OVERALL MOISTURE CONTENT IS NOTHING NOTEWORTHY FOR JULY (CLOSE TO
CLIMATOLOGICAL MEANS BETWEEN 1.0-1.5 INCHES). NORTH WINDS AND
DRIER AIR WILL ALREADY BE MOVING INTO THE NORTHERN SECTIONS OF THE
FORECAST AREA BY NOON...ESSENTIALLY ENDING ANY CHANCE FOR A
PASSING SHOWER. HOWEVER...FOR THE SOUTHEASTERN THIRD OF THE
FORECAST AREA...INSTABILITY IS EXPECTED TO BUILD AHEAD OF THE
FRONT. THUS...MAINLY BETWEEN NOON AND 6PM...SOME SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP.
WITH THE PASSAGE OF THE FRONT...THERE SHOULD BE A GRADIENT FOR MAX
TEMPS...WITH UPPER 70S IN THE NORTH AND MID 80S IN THE SOUTH.
SKIES WILL CLEAR FROM THE NORTH DURING THE EVENING...AND MOSTLY
CLEAR CONDITIONS ARE EXPECTED OVERNIGHT. WITH DEWPOINTS ALSO
SIGNIFICANTLY LOWER THAN EARLY TUESDAY MORNING (AS MUCH AS 10-15
DEGREES LOWER)...MIN TEMPS WILL EASILY BE ABLE TO DROP BELOW
NORMAL BY WEDNESDAY MORNING...IN THE UPPER 50S TO AROUND 60
DEGREES.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
HAVE USED A BLEND OF THE GFS/ECMWF/WPC FOR THE LONG TERM FORECAST.
FOR THE PERIOD WEDNESDAY THROUGH FRIDAY...AS A MID LEVEL RIDGE
REASSERTS ITSELF NORTHWARD INTO THE PLAINS...WE WILL REMAIN IN A
NORTHWEST FLOW ALOFT. SURFACE HIGH PRESSURE IS EXPECTED TO TRAVERSE
OUR REGION. AT THIS TIME...IT SHOULD REMAIN DRY...WITH JUST SOME
CLOUDS FROM TIME TO TIME.
FOR THE WEEKEND...IT NOW LOOKS LIKE A WEAK FRONTAL SYSTEM WILL PUSH
THROUGH OUR REGION. WE MAY REMAIN DRY DURING THE DAY SATURDAY...WITH
CHANCE POPS FOR SHOWERS/STORMS ADDED TO THE FORECAST FOR SATURDAY
NIGHT INTO SUNDAY.
FOR MONDAY...CURRENT FORECAST CALLS FOR DRY CONDITIONS AS MODELS
SUGGEST WE WILL BE BETWEEN SYSTEMS.
DRIER AIR AND SLIGHTLY BELOW NORMAL TEMPERATURES CAN BE EXPECTED
THROUGH AT LEAST FRIDAY...WITH AN UPTICK IN HIGHS AND HUMIDITY BY
THE WEEKEND INTO NEXT WEEK.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
PESKY STRATUS DECK AT KILN IS FINALLY BREAKING UP AND REST OF CWA
WILL CONTINUE TO SEE CU DEVELOPMENT THIS AFTERNOON TOPPED BY THIN
CI. STORMS WILL BECOME MORE PROMINENT LATER THIS EVENING AND END
OVERNIGHT. SURFACE FRONT CROSSES CWA TOWARDS 12Z TOMORROW MORNING
AND WINDS SHIFT NORTHWARD WITH A DRIER AIRMASS EXPECTED IN ITS
WAKE AS HIGH PRESSURE BUILDS NORTH AND WEST OF THE REGION.
VFR CONDITIONS ARE EXPECTED OUTSIDE OF THUNDERSTORM ACTIVITY
TONIGHT.
OUTLOOK...NO SIGNIFICANT WEATHER IS EXPECTED AT THIS TIME.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...HICKMAN
AVIATION...FRANKS
THE LONG TERM FORECAST DISCUSSION WILL BE UPDATED SHORTLY
PREVIOUS DISCUSSION >
UPPER RIDGING WILL DEVELOP INTO THE REGION DURING THE LATTER PART
OF THE WEEK. BUT THEN ANOTHER SYSTEM MOVING ALONG THE NORTHERN
TIER WILL SUPPRESS THE RIDGE AND TEMPORARILY BRING TROUGHING BACK
TO THE GREAT LAKES AND UPPER OHIO VALLEY OVER THE WEEKEND.
AT THE SURFACE HIGH PRESSURE WILL PREDOMINATE THROUGH FRIDAY WITH
BELOW NORMAL TEMPERATURES THAT WILL SLOWLY MODERATE. FORECAST THEN
LEANS TOWARDS GFS ENSEMBLE MEAN WHICH IS A COMPROMISE BETWEEN MORE
AGGRESSIVE/FASTER 00Z GFS AND SLOWER 00Z ECMWF IN DROPPING A
FRONT INTO THE REGION OVER THE WEEKEND. THIS FRONT WILL BRING A
CHANCE OF SHOWERS AND THUNDERSTORMS ALTHOUGH TEMPERATURES WILL BE
SEASONAL.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
PESKY STRATUS DECK AT KILN IS FINALLY BREAKING UP AND REST OF CWA
WILL CONTINUE TO SEE CU DEVELOPMENT THIS AFTERNOON TOPPED BY THIN
CI. STORMS WILL BECOME MORE PROMINENT LATER THIS EVENING AND END
OVERNIGHT. SURFACE FRONT CROSSES CWA TOWARDS 12Z TOMORROW MORNING
AND WINDS SHIFT NORTHWARD WITH A DRIER AIRMASS EXPECTED IN ITS
WAKE AS HIGH PRESSURE BUILDS NORTH AND WEST OF THE REGION.
VFR CONDITIONS ARE EXPECTED OUTSIDE OF THUNDERSTORM ACTIVITY
TONIGHT.
OUTLOOK...NO SIGNIFICANT WEATHER IS EXPECTED AT THIS TIME.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...
AVIATION...FRANKS
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
335 PM CDT MON JUL 20 2015
.DISCUSSION... JUST NOW SEEING THE BEGINNINGS OF THE NEXT MCS WHICH
IS EXPECTED TO MOVE OUR WAY TONIGHT. CONFIDENCE IS NOT REAL HIGH.
HOWEVER...DEVELOPMENT OVER EASTERN MO IS SUPPORTED BY THE HRRR BUT
THE MODELS TRANSFER THE BULK OF THE MOISTURE ON AN EASTWARD
TRACK...PRIMARILY NORTH OF OUR AREA. AT ANY RATE...FOR THE FCST THIS
EVENING...WILL ADHERE LARGELY TO THE LATEST RADAR SCANS AND INCLUDE
POPS BASED ON TRENDS. OVERNIGHT HOWEVER...WILL NEED TO KEEP POPS A
LITTLE ELEVATED ACROSS OUR NORTHWEST AREAS. AS FOR SEVERE
POTENTIAL...OUR NW COUNTIES ARE STILL IN A SLIGHT RISK. NOT REALLY
SEEING MUCH UPPER DIVERGENCE SUPPORT BUT LOW LEVEL FORCING WILL
COMBINE WITH A 20 KT FLOW AT 850 TO PERHAPS MAKE THINGS INTERESTING.
TUESDAY AND WEDNESDAY...MODEL DIFFERENCES DO ABOUND AS FAR AS THE
SOUTHWARD INTRUSION OF THE DRY AIR GOES AS WELL AS THE SOUTHWARD
EXTENT OF THE FRONTAL BOUNDARY. GFS IS MORE BULLISH BUT
STILL...CAPES ARE RATHER HEFTY THE NEXT 2 AFTERNOONS ACROSS OUR
SOUTH. OVERALL...MODELS HAVE BACKED OFF ON THE OVERALL CONVECTION
CHANCES. I WILL MAKE A SLIGHT DOWNWARD TREND BUT GIVEN THE FACT THAT
THE EURO AND NAM ARE MORE UNCERTAIN WITH THE FRONTS SOUTHWARD
PROGRESS...LOW POPS WILL GENERALLY STILL REMAIN.
FOR THE NEAR TERM TEMPS...MANY PLACES ARE CURRENTLY IN THE 100 TO
105 HEAT INDEX ZONE. WILL GO AHEAD AND ALLOW THE HEAT ADVISORY TO
CONTINUE UNTIL 7 PM AS SCHEDULED. OTW...NUMERICAL MODELS ALL HINT
TOWARD LOWER HUMIDITIES BEGINNING ON WEDNESDAY. TEMPS WILL BACK OFF
A FEW DEGREES FOR BOTH HIGHS AND LOWS AS WE RETURN TO MORE NORMAL
VALUES AND HUMIDITIES.
IN THE EXT FCST...THE POTENTIALLY ACTIVE NW FLOW PATTERN WILL
CONTINUE THU AND FRIDAY. OVER THE WEEKEND...HOWEVER...UPPER RIDGE
OVER THE SOUTHERN PLAINS WILL STRENGTHEN. HEIGHTS WILL RISE OVER TN
AND POPS WILL LOWER.
WE WILL SEE A WARMING TREND WITH TEMPS BACK UP INTO THE 90S THROUGH
MUCH OF THE EXTENDED BUT THE LOWER LEVEL GULF FETCH WILL NO LONGER
BE IN TACT. THUS...A SOMEWHAT DRIER AND LESS HUMID TEMP REGIME IS
EXPECTED. INSTEAD OF THE MID 70S DEWPOINTS...WE WILL BE LOOKING AT
UPPER 60S TO NEAR 70 DEWPOINTS...WHICH IS A CONSIDERABLE
DIFFERENCE.
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 76 93 72 90 / 30 30 20 30
CLARKSVILLE 73 91 69 86 / 50 30 20 20
CROSSVILLE 72 88 68 84 / 40 30 30 20
COLUMBIA 76 94 72 90 / 30 30 30 30
LAWRENCEBURG 75 94 72 90 / 20 40 30 40
WAVERLY 73 91 70 87 / 40 30 30 30
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR TNZ005>009-023>030-
056>064-075-077-093>095.
&&
$$
21
AREA FORECAST DISCUSSION
NWS AMARILLO TX
242 PM CDT MON JUL 20 2015
.DISCUSSION...
LATEST WATER VAPOR CHANNEL LOOP AND GOES DERIVED TPW SHOWS ANOMALOUS
MOISTURE FLOWING NORTHWARD ACROSS EASTERN NEW MEXICO ON THE WESTERN
EDGE OF UPPER RIDGE. 12Z SOUNDINGS CONFIRM THIS WITH A SIGNIFICANT
INCREASE IN PWAT FROM 00Z LAST NIGHT (1.47 VS 0.82 INCHES). THIS IS
APPROACHING 2 STANDARD DEVIATIONS ABOVE CLIMATOLOGY. DOWNSTREAM...A
SHORTWAVE AND EXTENSIVE CONVECTION CONTINUES TO MOVE EASTWARD OUT OF
THE CENTRAL PLAINS TOWARD THE MIDDLE MISSISSIPPI VALLEY WITH WEAK
SUBSIDENCE EVIDENT BEHIND IT. VISIBLE SATELLITE REVEALS SOME
MID-HIGH LEVEL CLOUDS LEFT IN THE WAKE OF OVERNIGHT CONVECTION AND
THIS COULD POTENTIALLY LIMIT DIABATIC HEATING SOME THIS AFTERNOON
WITH A TREND TOWARD PARTIAL CLEARING IN THE FAR SOUTH TEXAS
PANHANDLE. SUBJECTIVE SURFACE ANALYSIS AT 18Z SHOWS A WEAK COLD
FRONT/COMPOSITE OUTFLOW ORIENTED NORTHEAST TO SOUTHWEST FROM NEAR
WHEELER TO JUST SOUTH OF CANYON. STORMS HAVE ALREADY FORMED NEAR
CLOVIS AND CU/TCU HAS RECENTLY FORMED NEAR THIS BOUNDARY FURTHER
EAST ACROSS THE FAR SOUTHERN PORTION OF OUR AREA. THIS SHOULD BE THE
INITIAL FOCUS WITH MORE WIDESPREAD CONVECTION OCCURRING LATER THIS
EVENING.
THE TENDENCY OF MID LEVEL HEIGHTS WILL BE TO FALL SLIGHTLY AS UPPER
RIDGE DEAMPLIFIES AND THIS SHOULD SUPPORT GREATER COVERAGE OF
CONVECTION THAN HAS BEEN SEEN IN PREVIOUS DAYS. PRESENCE OF
ANOMALOUS MOISTURE COMBINED WITH SLOW STORM MOTIONS RAISES CONCERN
FOR FLASH FLOODING. FLASH FLOOD GUIDANCE IS AT OR ABOVE CURRENT QPF
OUTPUT FROM MOST GUIDANCE. IN THE ABSENCE OF A WELL DEFINED
SHORTWAVE TO FOCUS DEVELOPMENT BELIEVE THAT THE IMPACTS WOULD BE
LOCALIZED. SOME OF THE SHORT RANGE HI-RES GUIDANCE AMOUNTS ARE MORE
AGGRESSIVE BUT THERE IS SOME QUESTION ABOUT HOW MUCH OF THIS IS
INFLUENCED BY THE BAD AWOS OBSERVATION AT PLAINVIEW/KPVW. THIS IS
GETTING INTO THE RAP AND HAS CONSISTENTLY RESULTED IN A SPURIOUS
7000+ CAPE BULLSEYE IN THE SOUTH TEXAS PANHANDLE THE LAST SEVERAL
DAYS. CAM GUIDANCE NESTED WITHIN THE RAP SUCH AS THE HRRR MAY BE
EXAGGERATED WITH CONVECTIVE COVERAGE AND QPF AS A RESULT.
SEVERE THUNDERSTORMS ARE A SECONDARY CONCERN TODAY ALTHOUGH DEEP
LAYER SHEAR SHOULD BE TOO WEAK TO SUPPORT SUSTAINED UPDRAFTS. SEVERE
EPISODES SHOULD BE BRIEF AND MARGINAL. MID LEVEL LAPSE RATES ARE NOT
PARTICULARLY STEEP WHICH IS TYPICAL FOR THIS MONSOON PATTERN BUT ARE
STEEP ENOUGH TO SUPPORT AROUND 1000 J/KG CAPE IN THE HAIL GROWTH
ZONE. ISOLATED OCCURRENCES OF MARGINALLY SEVERE HAIL ARE POSSIBLE
BUT MODERATE INSTABILITY AND WEAK SHEAR SUPPORTING FAIRLY INTENSE
BUT VERTICAL UPDRAFTS WITH WATER LOADING BENEATH STEEPENING LOW
LEVEL LAPSE RATES SHOULD SUPPORT PRIMARILY A WIND THREAT FROM BRIEF
DOWNBURSTS LATE THIS AFTERNOON THROUGH AT LEAST MID EVENING.
OVERNIGHT...WEAK ASCENT IS DEPICTED BY THE MODELS ON THE 315K
SURFACE WHICH IS FAIRLY MOIST AND THIS SHOULD BE ENOUGH TO SUSTAIN
CHANCES FOR CONVECTION INTO THE NIGHT AND IN A WEAKENED STATE
PROBABLY EVEN INTO THE MORNING HOURS ESPECIALLY ACROSS THE EAST.
SIMILAR CHALLENGES TO TODAY ARE EXPECTED TOMORROW WITH OVERNIGHT
CONVECTION AND MESOSCALE BOUNDARIES/RESIDUAL CLOUDS MAKING SPATIAL
AND TEMPORAL DETAILS UNCLEAR AT THIS POINT. FORECAST CONFIDENCE
SHOULD INCREASE LATER TONIGHT AND BY MORNING AS WE MONITOR HOW
EVENING/OVERNIGHT CONVECTION EVOLVES. STARTING WEDNESDAY MID LEVEL
HEIGHTS RISE AS UPPER HIGH BUILDS NORTH/NORTHWESTWARD ONCE AGAIN
RESULTING IN DRY WEATHER AND WARMER TEMPERATURES THROUGH AT LEAST
THE END OF THE WEEK. TOWARD SATURDAY MEDIUM RANGE GUIDANCE CONSENSUS
IS FOR RIDGE FLATTENS AGAIN AND MEAN WEST-NORTHWESTERLY FLOW MAY BE
ENOUGH FOR CONVECTION TO MOVE INTO AT LEAST WESTERN AND NORTHERN
SECTIONS.
BRB
&&
.PRELIMINARY POINT TEMPS/POPS...
AMARILLO TX 89 66 82 66 91 / 40 60 50 30 10
BEAVER OK 91 68 78 66 91 / 30 60 60 50 20
BOISE CITY OK 84 63 79 62 92 / 30 60 60 40 20
BORGER TX 91 70 82 69 94 / 30 60 60 40 20
BOYS RANCH TX 89 67 84 67 95 / 40 60 60 30 20
CANYON TX 91 66 84 65 92 / 40 60 50 30 10
CLARENDON TX 95 69 85 68 94 / 30 60 50 30 10
DALHART TX 86 65 82 65 94 / 40 60 60 30 20
GUYMON OK 91 67 80 65 93 / 30 60 60 50 20
HEREFORD TX 92 66 86 66 92 / 40 60 50 30 20
LIPSCOMB TX 94 69 79 67 93 / 30 60 60 50 20
PAMPA TX 90 66 79 65 91 / 30 60 60 40 10
SHAMROCK TX 96 70 85 68 95 / 30 60 50 40 10
WELLINGTON TX 98 71 89 69 97 / 20 50 50 30 10
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
17
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
134 PM EDT MON JUL 20 2015
.SYNOPSIS...
A COLD FRONT EXTENDING FROM LAKE ONTARIO TO IOWA THIS MORNING WILL
MOVE SOUTH INTO THE REGION TODAY. A SECOND STRONGER FRONT WILL
PASS THROUGH THE REGION LATE TUESDAY. EXPECT PERIODS OF SHOWERS
AND THUNDERSTORMS AHEAD OF THE FRONTS...THEN DRY WEATHER WITH LESS
HUMID AND COOLER AIR BEHIND THE BOUNDARY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1245 PM EDT MONDAY...
THE FORECAST UPDATE FOR THIS AFTERNOON WILL REFLECT A DECREASE IN
PRECIPITATION CHANCES ACROSS THE AREA UNTIL LATER THIS AFTERNOON.
THE NEWLY ARRIVED 12Z/8AM NAM AND GFS SUPPORT WHAT THE MESO-SCALE
MODELS HAVE BEEN HINTING AT...NAMELY LESS COVERAGE OF SHOWERS AND
STORMS TODAY UNTIL LATER IN THE AFTERNOON...WITH THE GREATEST
CONCENTRATION OVER THE FAR SOUTHWEST PORTION OF THE AREA. THIS
APPEARS REASONABLE GIVEN OUR MOST RECENT RADAR TRENDS OF VERY
LITTLE IN THE WAY OF SHOWERS ACROSS THE REGION...WITH NO
THUNDERSTORMS CURRENTLY. FOR HIGH TEMPERATURES...HAVE MADE ONLY
SMALL CHANGES TO THE ONGOING FORECAST. THE BIGGEST ADJUSTMENT WAS
A SLIGHT LOWERING OF TEMPERATURES ACROSS THE NORTHERN MOUNTAINS OF
NORTH CAROLINA WHERE SHOWERS WERE PERSISTENT THROUGH THE
MORNING...AND LINGERING CLOUD COVER WILL HELP SLOW THE RISE OF
TEMPERATURES THIS AFTERNOON.
AS OF 955 AM EDT MONDAY...
SHOWERS ACROSS THE AREA ARE OCCURRING IN TWO DISTINCT AREAS. THERE
ARE WEAK AND ISOLATED SHOWERS HEADING EASTWARD THROUGH PARTS OF
BATH AND ALLEGHANY COUNTIES OF VIRGINIA. THERE ARE MORE
SUBSTANTIAL SHOWERS...AND A FEW THUNDERSTORMS...HEADING SOUTHEAST
THROUGH THE NORTHERN MOUNTAINS OF NORTH CAROLINA FROM NORTHEAST
TENNESSEE. COVERAGE WILL CONTINUE TO BE MINIMAL THROUGH THE
REMAINDER OF THE MORNING HOURS AND ALSO THE EARLY AFTERNOON. LOOK
FOR COVERAGE IN INCREASE ONCE WE REACH THE MID AFTERNOON...AND
CONTINUE INTO THE EVENING HOURS. NO NOTABLE CHANGES HAVE BEEN MADE
TO THE FORECAST HIGH TEMPERATURES. HOWEVER...SOME MINOR
ADJUSTMENTS WERE MADE TO THE HOURLY TEMPERATURES THROUGH THE NEXT
FEW HOURS BASED UPON CURRENT OBSERVATIONS AND EXPECTED TRENDS.
AS OF 400 AM EDT MONDAY...
500 MB SHORT WAVE MOVING INTO WEST VIRGINIA WILL BRING SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS INTO THE WESTERN COUNTY WARNING
AREA THIS MORNING. HRRR AND LOCAL WRF SHOWED SOME INDICATIONS THAT
PRECIPITATION MAY SURVIVE ACROSS THE NORTHERN COUNTY WARNING AREA
BUT OVERALL TREND WILL BE FOR SHOWERS AND THUNDERSTORMS TO WEAKEN
BEFORE 12Z/8AM.
WEST TO NORTHWEST SURFACE AND LOW LEVEL WIND EXPECTED TODAY WHICH
FAVORS DEVELOPMENT OF ADDITIONAL SHOWERS AND THUNDERSTORMS AGAIN
IN THE MOUNTAINS THIS AFTERNOON. WITH LEE TROUGHING IN
PLACE...FAR EASTERN PIEDMONT MAY ALSO HAVE BETTER COVERAGE.
WEST TO NORTHWEST WINDS WILL CREATE DOWNSLOPING AND MIXING BY THIS
AFTERNOON...ENOUGH TO LOWER DEW POINTS INTO THE 60S IN THE
FOOTHILLS AND KEEP THE HEAT INDEX EAST OF THE BLUE RIDGE FROM
REACHING ADVISORY LEVELS. NO HEAT ADVISORY PLANNED AT THIS TIME.
MORE ORGANIZED SHOWERS AND THUNDERSTORMS WILL DEVELOP AHEAD OF
THE FRONT ACROSS THE OHIO VALLEY THIS AFTERNOON. THESE STORMS WILL
MOVE INTO THE WESTERN COUNTY WARNING AREA LATE TONIGHT.
USED A BLEND OF BIAS CORRECTED MET/MAV GUIDANCE FOR MAXIMUM
TEMPERATURES TODAY AND LOWS TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 AM EDT MONDAY...
A COLD FRONT WILL MOVE OVER THE OHIO RIVER VALLEY TUESDAY MORNING
AND IS EXPECTED TO JUMP TO THE LEE TROUGH PERCHED ACROSS THE
PIEDMONT IN THE AFTERNOON. A PREFRONTAL SHORT WAVE WILL TRACK ACROSS
KENTUCKY TUESDAY MORNING...BRINGING SHOWERS AND POSSIBLY A FEW
RUMBLES OF THUNDER...TO THE FAR WESTERN FORECAST AREA (BLUEFIELD VA-
LEWISBURG WV). LOW AND MID LEVEL FLOW TURNS WESTERLY
QUICKLY...REDUCING SHOWER ACTIVITY MOVING EAST TO THE BLUE RIDGE.
MORNING SHOWERS MAY NOT COMPLETELY FADE AS THEY APPROACH THE BLUE
RIDGE AS THIS WAVE TRACKS EAST OVER THE AREA. AS THE FRONT JUMPS TO
THE LEE TROUGH IN THE AFTERNOON...A NEW LINE OF CONVECTION WILL
FORM. ALL MODELS ARE HAVING A TOUGH TIME PINPOINTING WHERE THIS LINE
WILL INITIATE. BASED ON WHERE MODELS HAVE THE LEE TROUGH
POSITIONED...THIS LINE WILL BE EAST OF HWY 29...POSSIBLY EAST OF HWY
501. THE DEW POINT FRONT LAGS BEHIND AND THE MOUNTAINS MAY NOT SEE
SHOWERS CLEARING THE AREA UNTIL LATE IN THE EVENING...WITH CLEARING
IN THE PIEDMONT DURING THE EARLY MORNING HOURS WEDNESDAY. BY SUNRISE
WEDNESDAY MORNING...THE DEW POINT FRONT SHOULD BE SOUTH INTO NORTH
CAROLINA. A WEAK BUT COOL AREA OF HIGH PRESSURE WILL MOVE OVER THE
REGION WEDNESDAY...KEEPING THE REGION DRY FOR A COUPLE OF DAYS.
TUESDAY SHOULD BE THE LAST OF THE HOT DAY FOR THIS WEEK. DEPENDING
ON THE TIMING OF SHOWERS...HIGH TEMPERATURES ACROSS THE MOUNTAINS
WILL RANGE IN THE 80S...WITH LOWER TO MID 90S EAST. WEDNESDAY
TEMPERATURES WILL FALL BACK CLOSER TO NORMAL AS THE FRONT SINKS
SOUTH.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 350 PM EDT SUNDAY...
BROAD TROUGHING ACROSS THE NORTHEAST U.S. WILL DOMINATE THE
WEATHER AT THE BEGINNING OF THE PERIOD. THE FRONTAL
BOUNDARY/BAROCLINIC ZONE SHOULD BE LOCATED FROM THE MIDWEST INTO
THE SOUTHEAST STATES...HOPEFULLY SAFELY ENOUGH SOUTH OF OUR AREA
TO INHIBIT CONVECTION OF MUCH EXTENT. HOWEVER...WILL NEED TO WATCH
THURSDAY AS THERE IS YET ANOTHER UPSTREAM WAVE RIDING ALONG THE
BAROCLINIC ZONE THAT COULD BUCKLE THE BOUNDARY BACK FAR ENOUGH
NORTH TO ALLOW CONVECTION TO DRIFT BACK INTO THE SOUTHWEST PART OF
THE CWA...ESPECIALLY THE NW NC MOUNTAINS.
THERE IS BETTER PROBABILITY/CONFIDENCE THAT ONCE THIS FEATURE
PASSES BY TO THE SOUTH FRIDAY...WE WILL SEE GREATER POTENTIAL FOR
THE FRONTAL BOUNDARY TO DRIFT FURTHER SOUTH AND TAKE THE
CONVECTION WITH IT.
A WEAK UPPER LOW CUTS OFF ACROSS THE SOUTHEAST STATES BY THE
WEEKEND AND STALLS. BY SAT-SUN...THE UPPER RIDGE AMPLIFIES ACROSS
THE CENTRAL U.S. AND WE QUICKLY RETURN BACK TO A MORE UNSTABLE
NORTHWEST FLOW AND THE POTENTIAL FOR UPSTREAM CONVECTIVE COMPLEXES
TO REACH THE REGION.
850MB TEMPS DROP BELOW +20C THU-SAT...CREEPING BACK ABOVE +20C
ACROSS MUCH OF THE CWA BY THE END OF NEXT WEEKEND. DEWPOINTS DROP
INTO THE 50S ACROSS THE NORTHERN PART OF THE CWA BY THU
MORNING...WHICH SHOULD BE QUITE REFRESHING...BEFORE THEY CREEP
BACK UP INTO THE 60S TO LOW 70S BY THE WEEKEND. NEAR TO SLIGHTLY
BELOW NORMAL TEMPS THU-FRI...SHOULD RETURN TO ABOVE NORMAL LEVELS
BY THE WEEKEND.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 130 PM EDT MONDAY...
CURRENTLY...ALL TAF SITES ALONG AND EAST OF THE BLUE RIDGE ARE
HOLDING WITH VFR CONDITIONS...WHILE KLWB/KBLF CONTINUE TO FLIRT WITH
THE VFR/MVFR LINE. CEILING HEIGHTS ARE EXPECTED TO CONTINUE TO CLIMB
INTO VFR CATEGORIES THROUGH THE AFTERNOON HOURS.
UPPER-LEVEL ENERGY WILL CROSSES THE AREA...AS A COLD FRONT SINKS
TOWARD THE WV/VA LINE THIS AFTERNOON. REMOVED VCTS FROM ALL SITES
EXCEPT KBLF DUE TO A DROP EXPECTED PRECIPITATION COVERAGE...IN
PART TO EARLY MORNING SHOWER ACTIVITY ACROSS THE RIVER VALLEYS OF
VA AND HIGHLANDS OF NC. NEAR-TERM MODELS TEND TO AGREE..WITH
LITTLE TO NO INITIATION EXPECTED THROUGH 00Z TONIGHT. THIS MAY
NEED AMENDING BASED ON FUTURE RADAR TRENDS...ESPECIALLY IF
HEATING BECOMES ENOUGH FOR SPOTTY INITIATION LATER THIS AFTERNOON.
EXPECT HIGHER PROBABILITY OF PRECIPITATION AND POTENTIAL STORM/LTG
FORMATION MAINLY IN THE FAR WEST. LOWER CONFIDENCE THAT STORMS WILL
IMPACT KLYH AND KDAN. THREAT OF SHOWERS AND THUNDERSTORMS WILL
DIMINISH AFTER SUNSET. REMOVED THE CHANCE OF PRECIPITATION FROM THE
FORECAST AFTER 02Z/10PM AT KBLF.
BR/FG FORMATION WILL BE WIDELY SCATTERED...AND LIKELY DEPENDENT ON
THE OCCURRENCE OF RAINFALL...AND RESIDUAL CLOUDS TUESDAY AM. KEPT
BR/FG FORMATION AT KLWB AND BR AT KBLF WITH MEDIUM CONFIDENCE. THE
REMAINDER OF THE SITES HAVE BEEN LEFT OFF DUE TO THE LIKELIHOOD OF
AN AM MID-DECK ALONG WITH LOW MON EVENING POPS. THIS MAY NEED TO BE
AMENDED BASED ON RAINFALL AMOUNTS EXPERIENCED.
EXTENDED AVIATION DISCUSSION...
MORE WIDESPREAD THUNDERSTORM FORMATION WILL OCCUR ON TUESDAY... AS A
REINFORCED FRONT SINKS SWD IN RESPONSE TO STRONGER UPPER TROUGH OVER
THE GREAT LAKES AND NORTHEAST UNITED STATES. A BIT CONCERNED WITH
THE TIMING OF THE DRY-AIR BEHIND THE FRONT...WHICH SOME MODELS BRING
INTO THE AREA WELL BEFORE PEAK-HEATING...WHICH COULD GREATLY
DIMINISH COVERAGE AND SEVERITY OF PRECIPITATION AND CONVECTION.
THIS FRONT SINKS SOUTH OF THE AREA FOR WEDNESDAY AND THURSDAY AND
BUCKLES NWD AGAIN FRIDAY. SO FOR NOW WILL EXPECT OVERALL VFR
CONDITIONS OUTSIDE CONVECTION TUESDAY...THEN FOG/STRATUS POSSIBLE
WED/THU MORNING IN THE BCB/LWB AREA PENDING HOW DRY THE AIR GETS
BEHIND THIS FRONT. THEN MORE SHOWERS AND STORMS POSSIBLE FRIDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/DS
SHORT TERM...RCS
LONG TERM...DS/JM
AVIATION...AMS/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1251 PM EDT MON JUL 20 2015
.SYNOPSIS...
A COLD FRONT EXTENDING FROM LAKE ONTARIO TO IOWA THIS MORNING WILL
MOVE SOUTH INTO THE REGION TODAY. A SECOND STRONGER FRONT WILL
PASS THROUGH THE REGION LATE TUESDAY. EXPECT PERIODS OF SHOWERS
AND THUNDERSTORMS AHEAD OF THE FRONTS...THEN DRY WEATHER WITH LESS
HUMID AND COOLER AIR BEHIND THE BOUNDARY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1245 PM EDT MONDAY...
THE FORECAST UPDATE FOR THIS AFTERNOON WILL REFLECT A DECREASE IN
PRECIPITATION CHANCES ACROSS THE AREA UNTIL LATER THIS AFTERNOON.
THE NEWLY ARRIVED 12Z/8AM NAM AND GFS SUPPORT WHAT THE MESO-SCALE
MODELS HAVE BEEN HINTING AT...NAMELY LESS COVERAGE OF SHOWERS AND
STORMS TODAY UNTIL LATER IN THE AFTERNOON...WITH THE GREATEST
CONCENTRATION OVER THE FAR SOUTHWEST PORTION OF THE AREA. THIS
APPEARS REASONABLE GIVEN OUR MOST RECENT RADAR TRENDS OF VERY
LITTLE IN THE WAY OF SHOWERS ACROSS THE REGION...WITH NO
THUNDERSTORMS CURRENTLY. FOR HIGH TEMPERATURES...HAVE MADE ONLY
SMALL CHANGES TO THE ONGOING FORECAST. THE BIGGEST ADJUSTMENT WAS
A SLIGHT LOWERING OF TEMPERATURES ACROSS THE NORTHERN MOUNTAINS OF
NORTH CAROLINA WHERE SHOWERS WERE PERSISTENT THROUGH THE
MORNING...AND LINGERING CLOUD COVER WILL HELP SLOW THE RISE OF
TEMPERATURES THIS AFTERNOON.
AS OF 955 AM EDT MONDAY...
SHOWERS ACROSS THE AREA ARE OCCURRING IN TWO DISTINCT AREAS. THERE
ARE WEAK AND ISOLATED SHOWERS HEADING EASTWARD THROUGH PARTS OF
BATH AND ALLEGHANY COUNTIES OF VIRGINIA. THERE ARE MORE
SUBSTANTIAL SHOWERS...AND A FEW THUNDERSTORMS...HEADING SOUTHEAST
THROUGH THE NORTHERN MOUNTAINS OF NORTH CAROLINA FROM NORTHEAST
TENNESSEE. COVERAGE WILL CONTINUE TO BE MINIMAL THROUGH THE
REMAINDER OF THE MORNING HOURS AND ALSO THE EARLY AFTERNOON. LOOK
FOR COVERAGE IN INCREASE ONCE WE REACH THE MID AFTERNOON...AND
CONTINUE INTO THE EVENING HOURS. NO NOTABLE CHANGES HAVE BEEN MADE
TO THE FORECAST HIGH TEMPERATURES. HOWEVER...SOME MINOR
ADJUSTMENTS WERE MADE TO THE HOURLY TEMPERATURES THROUGH THE NEXT
FEW HOURS BASED UPON CURRENT OBSERVATIONS AND EXPECTED TRENDS.
AS OF 400 AM EDT MONDAY...
500 MB SHORT WAVE MOVING INTO WEST VIRGINIA WILL BRING SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS INTO THE WESTERN COUNTY WARNING
AREA THIS MORNING. HRRR AND LOCAL WRF SHOWED SOME INDICATIONS THAT
PRECIPITATION MAY SURVIVE ACROSS THE NORTHERN COUNTY WARNING AREA
BUT OVERALL TREND WILL BE FOR SHOWERS AND THUNDERSTORMS TO WEAKEN
BEFORE 12Z/8AM.
WEST TO NORTHWEST SURFACE AND LOW LEVEL WIND EXPECTED TODAY WHICH
FAVORS DEVELOPMENT OF ADDITIONAL SHOWERS AND THUNDERSTORMS AGAIN
IN THE MOUNTAINS THIS AFTERNOON. WITH LEE TROUGHING IN
PLACE...FAR EASTERN PIEDMONT MAY ALSO HAVE BETTER COVERAGE.
WEST TO NORTHWEST WINDS WILL CREATE DOWNSLOPING AND MIXING BY THIS
AFTERNOON...ENOUGH TO LOWER DEW POINTS INTO THE 60S IN THE
FOOTHILLS AND KEEP THE HEAT INDEX EAST OF THE BLUE RIDGE FROM
REACHING ADVISORY LEVELS. NO HEAT ADVISORY PLANNED AT THIS TIME.
MORE ORGANIZED SHOWERS AND THUNDERSTORMS WILL DEVELOP AHEAD OF
THE FRONT ACROSS THE OHIO VALLEY THIS AFTERNOON. THESE STORMS WILL
MOVE INTO THE WESTERN COUNTY WARNING AREA LATE TONIGHT.
USED A BLEND OF BIAS CORRECTED MET/MAV GUIDANCE FOR MAXIMUM
TEMPERATURES TODAY AND LOWS TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 AM EDT MONDAY...
A COLD FRONT WILL MOVE OVER THE OHIO RIVER VALLEY TUESDAY MORNING
AND IS EXPECTED TO JUMP TO THE LEE TROUGH PERCHED ACROSS THE
PIEDMONT IN THE AFTERNOON. A PREFRONTAL SHORT WAVE WILL TRACK ACROSS
KENTUCKY TUESDAY MORNING...BRINGING SHOWERS AND POSSIBLY A FEW
RUMBLES OF THUNDER...TO THE FAR WESTERN FORECAST AREA (BLUEFIELD VA-
LEWISBURG WV). LOW AND MID LEVEL FLOW TURNS WESTERLY
QUICKLY...REDUCING SHOWER ACTIVITY MOVING EAST TO THE BLUE RIDGE.
MORNING SHOWERS MAY NOT COMPLETELY FADE AS THEY APPROACH THE BLUE
RIDGE AS THIS WAVE TRACKS EAST OVER THE AREA. AS THE FRONT JUMPS TO
THE LEE TROUGH IN THE AFTERNOON...A NEW LINE OF CONVECTION WILL
FORM. ALL MODELS ARE HAVING A TOUGH TIME PINPOINTING WHERE THIS LINE
WILL INITIATE. BASED ON WHERE MODELS HAVE THE LEE TROUGH
POSITIONED...THIS LINE WILL BE EAST OF HWY 29...POSSIBLY EAST OF HWY
501. THE DEW POINT FRONT LAGS BEHIND AND THE MOUNTAINS MAY NOT SEE
SHOWERS CLEARING THE AREA UNTIL LATE IN THE EVENING...WITH CLEARING
IN THE PIEDMONT DURING THE EARLY MORNING HOURS WEDNESDAY. BY SUNRISE
WEDNESDAY MORNING...THE DEW POINT FRONT SHOULD BE SOUTH INTO NORTH
CAROLINA. A WEAK BUT COOL AREA OF HIGH PRESSURE WILL MOVE OVER THE
REGION WEDNESDAY...KEEPING THE REGION DRY FOR A COUPLE OF DAYS.
TUESDAY SHOULD BE THE LAST OF THE HOT DAY FOR THIS WEEK. DEPENDING
ON THE TIMING OF SHOWERS...HIGH TEMPERATURES ACROSS THE MOUNTAINS
WILL RANGE IN THE 80S...WITH LOWER TO MID 90S EAST. WEDNESDAY
TEMPERATURES WILL FALL BACK CLOSER TO NORMAL AS THE FRONT SINKS
SOUTH.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 350 PM EDT SUNDAY...
BROAD TROUGHING ACROSS THE NORTHEAST U.S. WILL DOMINATE THE
WEATHER AT THE BEGINNING OF THE PERIOD. THE FRONTAL
BOUNDARY/BAROCLINIC ZONE SHOULD BE LOCATED FROM THE MIDWEST INTO
THE SOUTHEAST STATES...HOPEFULLY SAFELY ENOUGH SOUTH OF OUR AREA
TO INHIBIT CONVECTION OF MUCH EXTENT. HOWEVER...WILL NEED TO WATCH
THURSDAY AS THERE IS YET ANOTHER UPSTREAM WAVE RIDING ALONG THE
BAROCLINIC ZONE THAT COULD BUCKLE THE BOUNDARY BACK FAR ENOUGH
NORTH TO ALLOW CONVECTION TO DRIFT BACK INTO THE SOUTHWEST PART OF
THE CWA...ESPECIALLY THE NW NC MOUNTAINS.
THERE IS BETTER PROBABILITY/CONFIDENCE THAT ONCE THIS FEATURE
PASSES BY TO THE SOUTH FRIDAY...WE WILL SEE GREATER POTENTIAL FOR
THE FRONTAL BOUNDARY TO DRIFT FURTHER SOUTH AND TAKE THE
CONVECTION WITH IT.
A WEAK UPPER LOW CUTS OFF ACROSS THE SOUTHEAST STATES BY THE
WEEKEND AND STALLS. BY SAT-SUN...THE UPPER RIDGE AMPLIFIES ACROSS
THE CENTRAL U.S. AND WE QUICKLY RETURN BACK TO A MORE UNSTABLE
NORTHWEST FLOW AND THE POTENTIAL FOR UPSTREAM CONVECTIVE COMPLEXES
TO REACH THE REGION.
850MB TEMPS DROP BELOW +20C THU-SAT...CREEPING BACK ABOVE +20C
ACROSS MUCH OF THE CWA BY THE END OF NEXT WEEKEND. DEWPOINTS DROP
INTO THE 50S ACROSS THE NORTHERN PART OF THE CWA BY THU
MORNING...WHICH SHOULD BE QUITE REFRESHING...BEFORE THEY CREEP
BACK UP INTO THE 60S TO LOW 70S BY THE WEEKEND. NEAR TO SLIGHTLY
BELOW NORMAL TEMPS THU-FRI...SHOULD RETURN TO ABOVE NORMAL LEVELS
BY THE WEEKEND.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 1730 AM EDT MONDAY...
ISOLATED SHOWERS SHOWN ON RADAR WILL MOVE EAST AND WEAKEN BEFORE
14Z. NO IMPACT IS EXPECTED FOR LOCAL AIRPORTS. THERE WILL BE MORE
SHOWERS AND THUNDERSTORMS THIS AFTERNOON AS UPPER ENERGY CROSSES
THE AREA. EXPECT HIGHER PROBABILITY OF PRECIPITATION IN THE WEST.
LOWER CONFIDENCE THAT STORMS WILL IMPACT KLYH AND KDAN. THREAT OF
SHOWERS AND THUNDERSTORMS WILL DIMINISH AFTER SUNSET. REMOVED THE
CHANCE OF PRECIPITATION FROM THE FORECAST AFTER 03Z/11PM.
EXTENDED AVIATION DISCUSSION...
TUESDAY WILL SEE MORE WIDESPREAD THUNDERSTORMS SINCE A FRONT WILL
SINK SWD IN RESPONSE TO STRONGER UPPER TROUGH OVER THE GREAT
LAKES AND NORTHEAST UNITED STATES. THIS FRONT SINKS SOUTH OF THE
AREA FOR WEDNESDAY AND THURSDAY AND BUCKLES NWD AGAIN FRIDAY. SO
FOR NOW WILL EXPECT OVERALL VFR CONDITIONS OUTSIDE CONVECTION
TUESDAY...THEN FOG/STRATUS POSSIBLE WED/THU MORNING IN THE BCB/LWB
AREA PENDING HOW DRY THE AIR GETS BEHIND THIS FRONT. THEN MORE
SHOWERS AND STORMS POSSIBLE FRIDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/DS
SHORT TERM...RCS
LONG TERM...RAB
AVIATION...AMS/WP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
248 PM CDT MON JUL 20 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 248 PM CDT MON JUL 20 2015
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT
ANALYSIS SHOWED A DEEP TROUGH PLOWING INTO BRITISH COLUMBIA...
RIDGING OVER THE NORTHERN U.S. ROCKIES INTO ALBERTA /
SASKATCHEWAN...AND TROUGHING FROM NORTHERN ONTARIO INTO NORTHERN
MN. A SHORTWAVE WAS ALSO EVIDENT OVER EASTERN IOWA...WHICH
COMBINED WITH A SURGE OF 850MB MOISTURE TRANSPORT...MID LEVEL
FRONTOGENESIS AND PRECIPITABLE WATER AROUND 1.5 INCHES HELPED
BRING SHOWERS AND SOME THUNDERSTORMS TO THE SOUTHEAST HALF OF THE
FORECAST AREA THIS MORNING. A SURFACE COLD FRONT WAS ALSO MARCHING
THROUGH THE FORECAST AREA...NOW FROM GREEN BAY TO OELWEIN.
INSTABILITY HAS BEEN BEEN LIMITED DUE TO MORNING CLOUDS/SHOWERS...
BUT RAP MESOANALYSIS SUGGESTS UP TO 1000 J/KG OF MLCAPE EXISTS
ALONG THE FRONT. THIS INSTABILITY HAS RESULTED IN SOME ISOLATED
SHOWERS ALONG THE FRONT...WITH WEAK LOW LEVEL CONVERGENCE
PREVENTING MORE DEVELOPMENT. IN THE WAKE OF THE FRONT...
PRECIPITABLE WATER DROPS DOWN TO 0.75 INCHES...RESULTING IN DRYING
OF THE AIR INCLUDING AT THE SURFACE. HOWEVER...A FEW SHOWERS WERE
NOTED IN THE COLD POOL REGION UNDERNEATH THE TROUGH IN FAR
NORTHERN MN/ONTARIO. BREEZY CONDITIONS NOTED TOO BEHIND THE FRONT
WITH TIGHTER PRESSURE GRADIENT AND DAYTIME MIXING. THESE NORTHWEST
WINDS WERE DRIVING IN COLDER AIR...NOTED BY 850MB TEMPS OF 16-18C
AHEAD COMPARED TO 8-10C OVER NORTHERN MN. SURFACE RIDGE RESIDED
WELL TO THE WEST OVER THE WESTERN DAKOTAS.
ANY SHOWERS/STORMS THE DEVELOP ALONG THE COLD FRONT OVER THE
SOUTHEAST THIRD OF THE FORECAST AREA SHOULD EXIT BY 23/00Z AS THE
FRONT CONTINUES TO PUSH SOUTHEAST. AFTER THAT...COOLER...DRIER AIR
REMAINS ON TRACK TO DROP INTO THE REGION FOR TONIGHT AND MONDAY. THE
EXTENSION OF THE UPPER TROUGH IN NORTHERN MN LOOKS TO SWING ACROSS
ALL OF WI TONIGHT AND INTO THE EASTERN GREAT LAKES ON TUESDAY. THIS
UPPER TROUGH WILL HELP DRIVE 850MB TEMPS DOWN TO 10-11C BY 12Z TUE.
ANY OF THE SHOWERS ACCOMPANYING THE COLD POOL LOOK TO STAY WELL
NORTH AND DIMINISH WITH LOSS OF DAYTIME HEATING THIS EVENING. SKIES
WILL CLEAR OUT QUICKLY THIS EVENING AS DRY AIR INFILTRATES AND LOSS
OF DAYTIME HEATING DISSIPATES CUMULUS. IF NOT FOR A PERSISTENT
NORTHWEST BREEZE WE COULD SEE A DECENT VALLEY FOG EVENT.
NEVERTHELESS...THE MORE SHELTERED SMALLER VALLEYS LIKE THE WISCONSIN
WILL FOG. THE TYPICAL COLD SPOTS SHOULD ALSO RADIATE NICELY AND DIP
DOWN INTO THE UPPER 40S. THE REST OF THE REGION SHOULD SEE LOWS IN
THE 50S. PLENTY OF SUN ON TRACK FOR TUESDAY WITH DRY AIR IN PLACE
AND HIGH PRESSURE BUILDING IN. WITH 850MB TEMPS CLIMBING TO 12-14C
BY 00Z WEDNESDAY THANKS TO DEEP MIXING...HIGHS IN THE 70S SHOULD BE
COMMON WITH LOW 80S FOUND IN RIVER VALLEYS AND SANDY SOIL AREAS. THE
DEEP MIXING ALSO SHOULD PROMOTE IN QUITE A BIT LOWER DEWPOINTS
COMPARED TO TODAY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 248 PM CDT MON JUL 20 2015
UPPER RIDGING SEEN OVER THE NORTHERN ROCKIES AND SASKATCHEWAN /
ALBERTA IS PROGGED TO GRADUALLY MOVE EAST INTO THE REGION OVER
THE NEXT FEW DAYS...MOVING OVERHEAD AROUND 12Z FRIDAY. SUBSIDENCE
WITH THIS UPPER RIDGING BUILDING IN...COMBINED WITH THE FRONT
TODAY PUSHING ALL THE MOISTURE SOUTH OF I-70 RESULT IN DRY
CONDITIONS FOR THE MOST PART THROUGH THURSDAY NIGHT.
HOWEVER...THERE IS A BAND OF MID LEVEL FRONTOGENESIS THAT LOOKS TO
SET UP LATE WEDNESDAY INTO THURSDAY...SITUATED FROM CENTRAL MN
INTO NORTH CENTRAL WI. THE 20.12Z NAM/ECMWF/CANADIAN HAVE BACKED
OFF ON THE INTENSITY AND THUS QPF PRODUCTION TO THE POINT OF
NEARLY DRY. ON THE OTHER HAND THE 20.12Z GFS STILL PRODUCES SOME
QPF. BELIEVE THE GFS MIGHT BE OVERLY MOIST...A KNOWN BIAS...AND
THEREFORE HAVE TRENDED DRY FOR TAYLOR/CLARK COUNTIES DURING MID-
WEEK. TEMPERATURES WEDNESDAY AND THURSDAY WILL BE ON A WARMING
TREND AS 850MB TEMPS EVENTUALLY CLIMB TO 14-16C BY 00Z FRI. MAY
HAVE TO CONTEND WITH VALLEY FOG TUESDAY NIGHT WITH LIGHT
WINDS...BUT THERE ARE HINTS OF SOME CLOUDS PASSING THROUGH.
THEREFORE...HAVE KEPT MUCH FOG OUT.
FOR FRIDAY THROUGH MONDAY...THE MAIN FEATURE OF INTEREST IS A
PORTION OF THE DEEP TROUGH IN BRITISH COLUMBIA THAT DROPS THROUGH
THE REGION LATE FRIDAY THROUGH SATURDAY EVENING. 20.12Z
GFS/ECMWF/CANADIAN ALL WANT TO DEVELOP CONVECTION IN WARM ADVECTION
AHEAD OF THE SHORTWAVE TROUGH...THEN ADDITIONAL CONVECTION AS THE
COLD FRONT ASSOCIATED WITH THE TROUGH COMES THROUGH. SOME TIMING
ISSUES THUS PRECIPITATION CHANCES ARE SPREAD OUT...THOUGH IF TRENDS
CONTINUE SHOULD BE ABLE TO PULL OUT CHANCES FOR SATURDAY NIGHT AND
EVEN SATURDAY AFTERNOON. IF THE GFS PANS OUT WE MIGHT HAVE TO DEAL
WITH SOME SEVERE STORMS...PARTICULARLY FRIDAY NIGHT...BUT THE ECMWF
WOULD KEEP ITS SEVERE THREAT FARTHER TO THE SOUTHWEST. SOMETHING TO
WATCH. DRIER WEATHER THEN FOLLOWS FOR SUNDAY AS UPPER AND SURFACE
RIDGING BEGINS BUILDING BACK IN. PERHAPS ANOTHER INTERESTING PERIOD
COULD SETUP SUNDAY NIGHT AND MONDAY...PARTICULARLY IN THE ECMWF...AS
A SHORTWAVE COMES DOWN THE RIDGE BUILDING IN. FOR NOW JUST HAVE SOME
LOW CHANCES ON MONDAY PER CONSENSUS BUT THESE MAY NEED ADJUSTMENT.
OVERALL TEMPERATURES LOOK TO STAY AT OR ABOVE SEASONABLE
NORMALS...AND SOME OF THE HIGHS IN THE CURRENT FORECAST ALTHOUGH
NEAR CONSENSUS COULD END UP BEING A LITTLE HIGHER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1226 PM CDT MON JUL 20 2015
A COLD FRONT EXTENDED FROM NEAR KMCW TO KRST TO KRPD AT 20.1730Z
AND WILL CONTINUE TO SLIDE EAST-SOUTHEAST THROUGH THE AFTERNOON.
MAJORITY OF SHOWERS WITH EMBEDDED ISOLATED THUNDERSTORMS FROM
NORTHEAST IA INTO SOUTHERN WI/NORTHERN IL WILL MOVE OUT OF THE
REGION...BUT COULD SEE SOME SCATTERED CONVECTION REDEVELOP ALONG
THE COLD FRONT THIS AFTERNOON. THIS ACTIVITY SHOULD BE EAST OF THE
TAF SITES...KEEPING THEM DRY THROUGH THE PERIOD. DRY AIR MASS
BEHIND THE FRONT WILL RESULT IN MOSTLY SUNNY/CLEAR/VFR CONDITIONS
THROUGH 21.18Z. WINDS WILL SHIFT TO THE NORTHWEST WITH THE FRONTAL
PASSAGE...GUSTING OCCASIONALLY UP TO 20 KTS AT KRST THIS
AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...ROGERS