Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/14/12
AREA FORECAST DISCUSSION
NWS DENVER CO
331 PM MDT THU JUL 12 2012
.SHORT TERM...IN THE VERY SHORT TERM...MONITORING A LINE OF
CUMULUS/TOWERING CUMULUS BUILDING ALONG A SFC CONVERGENCE
BOUNDARY ALIGNED ACROSS SOUTHEAST ELBERT...NORTHERN LINCOLN...
SOUTHEAST WASHINGTON AND EASTERN PORTIONS OF PHILLIPS AND
SEDGWICK COUNTIES. LOWER/MID 50 DEWPTS POOLED ALONG THIS
LINE OF WITH THE 18Z/RUC INDICATING CAPES IN THE 1500-2000 J/KG
RANGE IN THE AREA. HOWEVER THE RUC WAS ALSO INDICATING
CIN/CONVECTIVE INHIBITION/ VALUES IN THE 40-80 J/KG IN THE AREA.
ONE REASON FOR THE SLUGGISH CONVECTIVE DEVELOPMENT OUT THAT WAY.
OTHERWISE HEAT GENERATED ISOLATED T-STORMS POPPING UP IN THE HIGH
COUNTRY GENERALLY LOW INTENSITY. LIGHT RAIN SHOWERS...CG
LIGHTNING AND GUSTY WINDS PRETTY MUCH ALL WE/VE SEEN SO FAR
THIS AFTERNOON. TRAJECTORY OF STORMS SHIFTED FROM SOUTHEASTERLY
TO SOUTHERLY EARLY IN THE AFTERNOON WITH THE UPPER RIDGE OUT WEST
NOSE EASTWARD OVER COLORADO. CURRENT PRECIPITABLE WATER VALUES
ALONG THE FRONT RANGE LOWER THAN 24 HRS AGO BY ABOUT 0.10
INCH...BUT UP SLIGHTLY IN THE PAST 1-2 HOURS WITH LIGHT
NORTHEASTERLY UPSLOPE FLOW. SHOULD COULD TO SEE FURTHER STORM
DEVELOPMENT IN THE HIGH COUNTRY AND ALONG THE CONVERGENCE BOUNDARY
ON THE PLAINS DURING THE NEXT 2-4 HOURS. WITH ALL THE PENT UP
ENERGY ALONG THE PLAINS BOUNDARY...WOULD NOT BE SURPRISED TO SEE A
FEW STORMS GENERATE HAIL AT LEAST 3/4 INCH IN DIAMETER...RAINFALL
RATES UP TO 0.75 INCH PER HOUR...AND OUTFLOW WIND GUSTS TO 50 MPH.
PROBABLY BEST CHANCE FOR THIS OCCURRING IS UP NEAR THE NORTHEAST
CORNER WHERE GREATEST CAPE VALUES NOW EXIST.
FOR TONIGHT...AFTER THE ISOLATED STORMS DESCRIBED ABOVE DISSIPATE
SOMETIME AROUND 20-21Z...SHOULD SEE SKIES CLEAR AND THE
DEVELOPMENT OF A TYPICAL NOCTURNAL DRAINAGE WIND PATTERN IN AND
NEAR THE HIGH TERRAIN...AND A SOUTHERLY WIND OF 8-15KT FARTHER OUT
ACROSS THE PLAINS. LOOK FOR LOWS TONIGHT NEAR SEASONAL VALUES.
ON FRIDAY...THE HOT UPPER RIDGE OUT WEST AT THE MOMENT MIGRATES
EASTWARD OVER COLORADO...RESULTING IN A MUCH LIGHTER FLOW ALOFT
AND LIGHTER WINDS AT THE SURFACE. WARMING ALOFT FURTHER
STABILIZES THE BOUNDARY LAYER ESPECIALLY OVER THE PLAINS.
THEREFORE CHANCES FOR STORMS AT LOWER ELEVATIONS LOWER THAN TODAY.
IN THE HIGH COUNTRY CHANCES ABOUT THE SAME...BUT ANY STORMS THAT
MANGE TO FORM IN THIS SLIGHTLY DRIER AND POORLY SHEARED ATMOSPHERE
NOT EXPECTED TO REMAIN INTACT FOR LONG. HIGH TEMPERATURES ON
FRIDAY 1-2C HIGHER THAN TODAY. COULD SEE THE MERCURY PUSHING THE
CENTURY MARK ALONG THE SOUTH PLATTE RIVER NORTHEAST OF DENVER.
.LONG TERM...A FEW STORMS WILL BE POSSIBLE ACROSS THE HIGHER
TERRAIN FRIDAY EVENING WHERE WEAK UPSLOPE WILL PERSIST. CAPES
MINIMAL...GENERALLY AROUND 200 J/KG...SO ANY STORMS WILL BE WEAK.
PRECIPITABLE WATER VALUES AROUND SIX TENTHS OF AN INCH...SO ONLY
LIGHT RAINFALL EXPECTED. MODELS SHOW UPPER RIDGE AXIS CENTERED
OVER COLORADO BEGINS TO SHIFT A BIT EASTWARD INTO EASTERN COLORADO
OVERNIGHT FRIDAY INTO SATURDAY. FLOW ALOFT TO BECOME MORE
SOUTHWEST ALLOWING FOR SOME INCREASE IN MOISTURE ACROSS AREA. A
FEW STORMS COULD LINGER BEYOND MIDNIGHT BUT WILL BE FIGHTING
SUBSIDENCE. ON SATURDAY...BOTH NAM AND GFS CONTINUE TO SHOW AN
INCREASE IN THE MOISTURE FROM THE SOUTHWEST ACROSS THE AREA...
THOUGH THE BULK OF THE MOISTURE LOOKS TO REMAIN WEST OF COLORADO.
THERE APPEARS TO BE SOME INCREASE IN MOISTURE ACROSS CENTRAL
PLAINS AS WELL. GFS PRECIPITABLE WATER VALUES INCREASE TO AROUND
EIGHT TENTHS OF AN INCH ACROSS THE MOUNTAINS BY AFTERNOON. SHOULD
SEE STORM CHANCES INCREASE..NAM LESS WITH VALUES AROUND SEVEN TENTHS OF
AN INCH. BOTH MODELS SIMILAR ACROSS PLAINS WITH VALUES CLOSE TO AN
INCH. MODEL CROSS SECTIONS SHOWING MOST OF THIS MOISTURE ABOVE
MOUNTAIN TOP. BETTER CHANCE FOR STORMS EXPECTED BY AFTERNOON...
MAINLY ACROSS MOUNTAINS AND HIGHER FOOTHILLS. CAPE VALUES ROUGHLY
IN THE 300-500 J/KG RANGE...SO NOT EXPECTING WIDESPREAD COVERAGE.
WINDS ALOFT WILL REMAIN LIGHT SO ANY STORMS WILL BE SLOW MOVING.
THE STRONGER STORMS COULD PRODUCE MODERATE TO BRIEF HEAVY RAIN.
TEMPERATURES ACROSS PLAINS LOOK TO REACH THE MID 90S. MODELS SHOW
RIDGE AXIS SHIFTING INTO WESTERN KANSAS SUNDAY...WHICH SHOULD
ALLOW FOR A BIT MORE MOISTURE TO BE ADVECTED INTO AREA IN THE
SOUTHWEST FLOW ALOFT. MODELS INDICATE 700 MB SPECIFIC WATER VALUES
INCREASING TO AROUND 8 G/KG. INTERESTING THAT THE GFS PRECIPITABLE
WATER VALUES IS ONLY AROUND EIGHT TENTHS OF AN INCH.
ANYWAY...SHOULD SEE A GOOD CHANCE OF MAINLY AFTERNOON AND EVENING
THUNDERSTORMS WITH THE BEST CHANCE OVER THE HIGHER TERRAIN.
STORMS TO BE SLOW MOVING AND COULD DUMP BRIEF HEAVY RAIN.
TEMPERATURES TO BE A FEW DEGREES COOLER WITH EXPECTED CLOUD COVER
AND ANTICIPATED PRECIPITATION.
PATTERN LOOKS TO CHANGE LITTLE MONDAY THROUGH THURSDAY...WITH A
CONTINUED MOISTURE FLOW FROM THE SOUTHWEST. MODELS CONTINUE TO
GENERATE QPF DURING THE AFTERNOON AND EVENING HOURS. WILL CONTINUE
THE SLIGHT CHANCE OF MAINLY AFTERNOON AND EVENING THUNDERSTORMS. MODELS
CONTINUE TO HINT AT A WEAK DISTURBANCE MOVING ACROSS THE AREA
TUESDAY WHICH COULD INCREASE STORM CHANCES ALONG WITH PERHAPS A
BETTER CHANCE OF PRECIPITATION. TEMPERATURES TO REMAIN NEAR OR
SLIGHTLY ABOVE NORMAL.
&&
.AVIATION...VFR CONDITIONS ANTICIPATED AT DENVER AREA AIRPORTS
DURING THE NEXT 24 HOURS. ANY HIGH BASED CONVECTION PASSING OVER
THE DENVER METRO AREA BETWEEN 21Z/THU AND 01Z/FRI COULD STILL
PRODUCE BRIEF OUTFLOW GUSTS TO 30KTS AND SOME CLOUD-TO-GROUND
LIGHTNING...BUT LITTLE IF ANY RAINFALL. AFTER 01Z THIS EVENING...
SKIES WILL GRADUALLY CLEAR WITH TYPICAL DRAINAGE WINDS OF 7-13KT
OVERNIGHT. ON FRIDAY...THIS DRAINAGE WIND PATTERN IS EXPECTED TO
LINGER THROUGH MOST OF THE MORNING BEFORE GRADUALLY SHIFTING A
TYPICAL UPSLOPE/EAST-NORTHEAST COMPONENT OF 6-12KT IN THE
AFTERNOON. ANY THUNDERSTORMS TOMORROW EXPECTED TO REMAIN WEST-
SOUTHWEST OF THE DENVER METRO AREA.
&&
.HYDROLOGY...NO THREAT OF HEAVY RAIN OR FLASH FLOODING DURING THE
NEXT 24 HOURS. ISOLATED WEAK THUNDERSTORMS DRIFTING SOUTHWEST OVER
THE FRONT RANGE MOUNTAINS AND FOOTHILLS COULD DEPOSIT UP TO 0.25
INCH IN 45 MINUTES AND WIND GUSTS TO 35 MPH. STORMS SHOULD END IN
THE MOUNTAIN AREAS BY 8 PM THIS EVENING.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BAKER
LONG TERM....D-L
AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1025 PM MDT WED JUL 11 2012
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 315 PM MDT WED JUL 11 2012
SMALL DISTURBANCE MOVING INTO NE UT AT MID-AFTERNOON REACHES FAR
NW CO THIS EVENING PER RAP MODEL. HIGH-RES MODELS DO NOT SHOW MUCH
PRECIP WITH IT...CONSISTENT WITH THE DRIER AIR SHOWN THERE ON THE
19Z PRECIPITABLE WATER ANALYSIS. BUT A BIT MORE VERTICAL SHEAR
WITH THIS DISTURBANCE COULD RESULT IN LONGER LIVED STORMS THERE.
DAYTIME HEATING AND INSTABILITY APPEARED TO BE THE MAIN DRIVER OF
AFTERNOON CONVECTION ACROSS THE CENTRAL AND SOUTHERN MTNS WITH THE
DEEPER MOISTURE ACROSS THE SOUTH WHERE LOCALLY MODERATE TO HEAVY
RAIN IS POSSIBLE. STORMS WILL DRIFT OVER THE LOWER VALLEYS LATE
TODAY AND THIS EVENING. A FEW STORMS MAY PRODUCE SMALL HAIL...AS
SOME DID TUESDAY EVENING. GUSTY OUTFLOW WINDS ARE POSSIBLE FROM
ANY STORM BUT ESPECIALLY ACROSS THE NORTH WHERE FORECAST SOUNDINGS
EXHIBITED A MORE PRONOUNCED INVERTED-V SIGNATURE. CONVECTION
SHOULD DIMINISH BY LATE EVENING.
NOT MUCH CHANGE IS EXPECTED ON THU WITH SOME AFTERNOON AND EVENING
THUNDERSTORMS ONCE AGAIN. AFTERNOON TEMPS WILL CLIMB ANOTHER
COUPLE OF DEGREES WITH SOME LOWER VALLEYS IN ERN UT AND WEST-
CENTRAL CO AROUND THE 100 DEG MARK. THE UPPER RIDGE THAT HAS BEEN
ENTRENCHED OVER THE GREAT BASIN SHOULD FINALLY BEGIN SLIDING EAST
LATE THU. MODELS HAVE IT CENTERED IN THE VICINITY OF THE 4 CORNERS
BY FRI MORNING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 315 PM MDT WED JUL 11 2012
THE HIGH PRESSURE CENTER WILL SHIFT SOUTHEAST IN RESPONSE TO LOW
PRESSURE MOVING INTO THE PACIFIC NORTHWEST LATE THIS WEEK. AS THE
HIGH SHIFTS EAST...THE SUB-TROPICAL MOISTURE PLUME WILL ALSO SHIFT
EAST FROM EASTERN NV/WESTERN UT TO EASTERN UT/WESTERN CO.
THEREFORE MOISTURE WILL BEGIN TO INCREASE OVER OUR AREA ON FRIDAY
AND DEEPEN ON SATURDAY...FOR A RETURN TO A WETTER REGIME. IN
ADDITION...THE GRADIENT WILL TIGHTEN BETWEEN THE PACIFIC LOW AND
THE HIGH PRESSURE MOVING TO OUR SOUTHEAST...FOR A MORE ENERGETIC
SOUTHWEST FLOW OVER OUR AREA. MODELS INDICATE A DISTURBANCE
ROTATING AROUND THE LOW FRI NIGHT INTO EARLY SAT MAY KEEP
CONVECTION ONGOING OVERNIGHT. BY SATURDAY THE HIGH WILL BE
CENTERED OVER NORTH-CENTRAL NM TO SOUTHEAST CO...THEN GRADUALLY
SHIFT EAST THROUGH THE FIRST HALF OF THE WORK WEEK. A MOIST AND
UNSTABLE SOUTHWEST FLOW WILL CONTINUE TO STREAM OVER THE AREA. ANY
EMBEDDED DISTURBANCES WILL ONLY ENHANCE CONVECTION. BY MIDWEEK THE
LOW SHIFTS EAST ACROSS THE NORTHERN ROCKIES AND DRIER AIR MOVES
INTO OUR AREA...ESPECIALLY OVER THE WEST-NORTHWEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1023 PM MDT WED JUL 11 2012
VFR CONDITIONS IN GENERAL EXPECTED AT THE TAF SITES THROUGH
THURSDAY NIGHT. ISOLATED TO SCATTERED AFTERNOON AND EVENING
THUNDERSTORMS WILL REDEVELOP THURSDAY AFTERNOON AND LINGER THROUGH
LATE THURSDAY EVENING. LOCAL MVFR CONDITIONS POSSIBLE IN STORMS
PRODUCING HEAVIER RAIN. ALL THUNDERSTORMS WILL BE CAPABLE OF
PRODUCING STRONG AND ERRATIC OUTFLOW WIND GUSTS.
&&
.FIRE WEATHER...
ISSUED AT 315 PM MDT WED JUL 11 2012
A FEW THUNDERSTORMS THIS EVENING AND AGAIN ON THURSDAY AFTERNOON
ALONG OVER THE FAR NORTH MAY PRODUCE LIGHTNING AND GUSTY WINDS BUT
LITTLE RAIN. HOWEVER THE COVERAGE OF THESE DRY STORMS IS EXPECTED
TO BE ISOLATED AT BEST...WITH SOME STORMS OVER THIS SAME PORTION
OF THE AREA PRODUCING BETTER RAINFALL. ISOLATED TO SCATTERED
STORMS OVER THE REMAINDER OF THE FORECAST AREA THROUGH THURSDAY
EVENING ARE GENERALLY EXPECTED TO BE OF THE WET VARIETY.
MOISTURE INCREASES OVER THE AREA BEGINNING ON FRIDAY AND INTO THE
WEEKEND. THEREFORE THE MAIN FIRE WEATHER CONCERN FOR LATE THIS
WEEK THROUGH EARLY NEXT WEEK WILL BE THE POTENTIAL FOR MODERATE TO
HEAVY RAIN ON RECENT BURN SCARS. ANY GOOD RAINS OVER THESE SCARS
COULD PRODUCE EXCESSIVE RUNOFF AND DEBRIS FLOWS.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...JAD
LONG TERM...EH
AVIATION...JDC
FIRE WEATHER...EH
AREA FORECAST DISCUSSION
NWS NEW YORK NY
147 PM EDT THU JUL 12 2012
.SYNOPSIS...
HIGH PRESSURE OVER THE REGION WILL RESULT IN A CONTINUATION OF
WARM AND DRY WEATHER THROUGH FRIDAY. HUMIDITY INCREASES OVER THE
WEEKEND AS A WARM FRONT MOVES NORTHEAST ACROSS THE REGION BRINGING
SCATTERED SHOWERS AND THUNDERSTORMS MAINLY SATURDAY NIGHT INTO
SUNDAY. A STATIONARY FRONT SETS UP OVER THE REGION EARLY NEXT WEEK
RESULTING IN A CONTINUATION OF THE WARM AND HUMID WEATHER.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A FEW SHOWERS AND TSTMS HAVE DEVELOPED SOUTH OF ALBANY. GIVEN THE
STRONG SUBSIDENCE OVER THE LOCAL AREA...AND THE RELATIVE SLOW
MOVEMENT OF THE STORMS...DO NOT THINK THEY WILL MAKE IT TO THE
LOCAL AREA. LATEST HRRR SHOWS SOME CONVECTION WELL NORTH OF THE
AREA...BUT NONE REALLY MAKES IT TO THE LOCAL AREA. WILL KEEP A DRY
FORECAST ON TAP FOR THE REST OF THE AFTERNOON.
VERY WARM DAY WITH HIGHS APPROACHING 90 FOR NYC/NORTHEAST
NJ...AND IN THE MID TO UPPER 80S ELSEWHERE. HIGHS ALONG THE COAST
WILL TOP OFF IN THE LOW TO MID 80S.
GENERALLY MOSTLY SUNNY SKIES ON TAP...BUT THAT SUN WILL BE
FILTERED THROUGH CIRRUS CLOUDS FROM TIME TO TIME. AFTERNOON
CUMULUS WILL DEVELOP DUE TO THE SEA BREEZE AND WITH AFTERNOON
HEATING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
ADDED SOME PATCHY FOG IN OUTLYING AREAS FOR LATE TONIGHT IN AREAS
SIMILAR TO WHERE FOG DEVELOPED LATE LAST NIGHT AND EARLY THIS
MORNING...GIVEN SIMILAR CONDS.
RIDGING CONTINUES TO BUILD IN ALOFT TONIGHT - HIGH LEVEL MOISTURE
INCREASE FROM DOWNSTREAM FLOW FROM THE MIDWEST UPPER TROUGH.
ATTM...THINK THAT THE CIRRUS WILL BE THIN. THUS...A MOSTLY CLEAR
NIGHT IS FCST WITH LIGHT/CALM WINDS. BLENDED MOS WAS USE.
FRIDAY APPEARS CLOSE TO A CARBON COPY OF TODAY. SEA BREEZES
DEVELOP A LITTLE SOONER DUE TO THE LACK OF ANY SYNOPTIC SURFACE
FLOW. IT MIGHT BE A DEGREE OR TWO WARMER...BUT A BIT MORE HUMID
WITH DEW POINT TEMPS IN THE LOWER 60S. STILL NOT BAD FOR MID
JULY.
THE PLUME OF THIN CIRRUS CONTINUES AND SUBSIDENCE ALOFT CONTINUES
TO SUPPRESS AFTN SHOWER/TSTM DEVELOPMENT.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
FRIDAY NIGHT...UNCERTAINTY EXISTS AS TO WHETHER FORCING AND DEEPER
LOW LEVEL THETA-E AIR ASSOCIATED WITH A WARM FRONT OVER THE DEEP
SOUTH ATTM WILL MAKE IT INTO THE AREA THIS EARLY...WITH THE GFS
FASTER AND THE ECMWF DELAYED UNTIL SAT AFTERNOON. DECIDED TO LEAN
SLIGHTLY IN FAVOR OF THE GFS...WITH DRY CONDS THE FIRST HALF OF FRI
NIGHT...AND LOW CHANCE POP FROM NYC WEST LATE AT NIGHT.
SATURDAY AND SUNDAY...HIGHER CONFIDENCE ON A VERY WARM...MOIST AND
INCREASINGLY UNSTABLE MARITIME TROPICAL AIR MASS MOVING IN AS
ISENTROPIC LIFT INCREASES BASED ON A DEPARTING OFFSHORE HIGH.
ALTHOUGH HIGH TEMPS ARE FORECAST TO RANGE FROM 85-90 BOTH DAYS
BECAUSE OF INCREASED CLOUD COVER...DEWPOINTS RISING INTO THE MID 60S
ON SAT AND LOWER 70S ON SUNDAY WILL MAKE IT FEEL UNCOMFORTABLE...
WITH MAX HEAT INDICES NEAR 90 ON SATURDAY AND MID 90S ON SUNDAY.
CHANCES FOR SHOWERS AND TSTMS WILL INCREASE WITH THE PASSAGE OF A
WARM FRONT ON SAT...THEN ALSO INTO SUNDAY WITH A WEAK SFC TROUGH
REMAINING NEARBY AND AS UPPER LEVEL DISTURBANCES RIDE AROUND AN
UPPER RIDGE TO THE SOUTH. THERE IS A CHC THAT CONVECTION THAT
DEVELOPS COULD PRODUCE TORRENTIAL RAIN AND FLASH FLOODING. STAY
TUNED.
MONDAY...THREAT OF ADDITIONAL SCT HVY SHOWERS AND TSTMS SHOULD
CONTINUE AS ADDITIONAL UPPER LVL SHORT WAVES APPROACH...WITH MAX
TEMPS IN THE LOWER 90S AND AND MAX HEAT INDICES IN THE MID AND UPPER
90S.
TUESDAY AND WEDNESDAY...FAIR AS HIGH PRESSURE BUILDS EAST.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
VFR THROUGH THE PERIOD WITH HIGH PRESSURE OVER THE REGION AND LOW
PRESSURE MOVING TO THE SOUTH AND EAST.
GENERALLY A SOUTH-SOUTHWEST FLOW WILL CONTINUE THROUGH THE
AFTERNOON WITH SPEEDS BETWEEN 6-12 KT. WINDS TONIGHT WILL BECOME
LIGHT AND VARIABLE AND CONTINUE THROUGH THE EARLY MORNING HOURS ON
FRIDAY. BY MID MORNING...SPEEDS WILL INCREASE TO AROUND 8 KT AND A
SOUTHERLY FLOW WILL DEVELOP.
...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)
KEWR FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KJFK FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KLGA FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KTEB FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KPHN FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KISP FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY...
.FRIDAY AFTERNOON-FRIDAY NIGHT...VFR.
.SATURDAY-MONDAY...MVFR POSSIBLE IN ISO-SCT SHRA/TSRA.
.TUESDAY...VFR.
&&
.MARINE...
MARINE FORECAST ON TRACK. SUB SMALL CRAFT CONDITIONS ARE
FORECAST TO CONTINUE THROUGH SUNDAY. SEAS ON THE OCEAN THIS
MORNING ARE AROUND 4 FT...BUT THESE ARE EXPECTED TO SLOWLY SUBSIDE
BY FRIDAY AND CONTINUE IN THE 2-3 FT RANGE THROUGH THE WEEKEND.
LIGHT WINDS WILL INCREASE TO AROUND 10 KT IN THE AFTERNOONS WITH
SEA BREEZE CIRCULATIONS.
COMBINED WIND WAVES FROM SW WINDS 10-15 KT AND INCOMING SE SWELLS
SHOULD BUILD SEAS UP TO 4 FT FOR A TIME SUNDAY NIGHT...JUST BELOW
SCA LEVELS.
&&
.HYDROLOGY...
NO RAINFALL IS EXPECTED THROUGH FRIDAY.
MULTIPLE ROUNDS OF SCT HVY SHOWERS AND TSTMS ARE POSSIBLE AS EARLY
AS FRIDAY NIGHT...BUT MORE LIKELY LATE SAT THROUGH MON. THIS IS
DUE TO AN APPROACHING WARM FRONT FRIDAY NIGHT INTO SATURDAY NIGHT
AND THE PASSAGE OF AN UPPER LEVEL DISTURBANCES SUNDAY/MONDAY.
HOURLY RAINFALL RATES COULD EXCEED 1 INCH PER HOUR AND CAUSE
LOCAL FLASH FLOODING AS PRECIPITABLE WATER VALUES RISE TO OVER 2
INCHES. MESO BETA ELEMENT / CORFIDI VECTORS OF 10 KT OR LESS
SUGGEST SLOW MOVING CONVECTIVE CLUSTERS AND POTENTIAL FOR URBAN
FLASH FLOODING.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JST
NEAR TERM...MPS
SHORT TERM...JST
LONG TERM...GOODMAN
AVIATION...BC
MARINE...GOODMAN/JST
HYDROLOGY...GOODMAN/JST
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1240 PM EDT THU JUL 12 2012
.SYNOPSIS...
HIGH PRESSURE OVER THE REGION WILL RESULT IN A CONTINUATION OF
WARM AND DRY WEATHER THROUGH FRIDAY. HUMIDITY INCREASES OVER THE
WEEKEND AS A WARM FRONT MOVES NORTHEAST ACROSS THE REGION BRINGING
SCATTERED SHOWERS AND THUNDERSTORMS MAINLY SATURDAY NIGHT INTO
SUNDAY. A STATIONARY FRONT SETS UP OVER THE REGION EARLY NEXT WEEK
RESULTING IN A CONTINUATION OF THE WARM AND HUMID WEATHER.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A FEW SHOWERS AND TSTMS HAVE DEVELOPED SOUTH OF ALBANY. GIVEN THE
STRONG SUBSIDENCE OVER THE LOCAL AREA...AND THE RELATIVE SLOW
MOVEMENT OF THE STORMS...DO NOT THINK THEY WILL MAKE IT TO THE
LOCAL AREA. LATEST HRRR SHOWS SOME CONVECTION WELL NORTH OF THE
AREA...BUT NONE REALLY MAKES IT TO THE LOCAL AREA. WILL KEEP A DRY
FORECAST ON TAP FOR THE REST OF THE AFTERNOON.
VERY WARM DAY WITH HIGHS APPROACHING 90 FOR NYC/NORTHEAST
NJ...AND IN THE MID TO UPPER 80S ELSEWHERE. HIGHS ALONG THE COAST
WILL TOP OFF IN THE LOW TO MID 80S.
GENERALLY MOSTLY SUNNY SKIES ON TAP...BUT THAT SUN WILL BE
FILTERED THROUGH CIRRUS CLOUDS FROM TIME TO TIME. AFTERNOON
CUMULUS WILL DEVELOP DUE TO THE SEA BREEZE AND WITH AFTERNOON
HEATING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
ADDED SOME PATCHY FOG IN OUTLYING AREAS FOR LATE TONIGHT IN AREAS
SIMILAR TO WHERE FOG DEVELOPED LATE LAST NIGHT AND EARLY THIS
MORNING...GIVEN SIMILAR CONDS.
RIDGING CONTINUES TO BUILD IN ALOFT TONIGHT - HIGH LEVEL MOISTURE
INCREASE FROM DOWNSTREAM FLOW FROM THE MIDWEST UPPER TROUGH.
ATTM...THINK THAT THE CIRRUS WILL BE THIN. THUS...A MOSTLY CLEAR
NIGHT IS FCST WITH LIGHT/CALM WINDS. BLENDED MOS WAS USE.
FRIDAY APPEARS CLOSE TO A CARBON COPY OF TODAY. SEA BREEZES
DEVELOP A LITTLE SOONER DUE TO THE LACK OF ANY SYNOPTIC SURFACE
FLOW. IT MIGHT BE A DEGREE OR TWO WARMER...BUT A BIT MORE HUMID
WITH DEW POINT TEMPS IN THE LOWER 60S. STILL NOT BAD FOR MID
JULY.
THE PLUME OF THIN CIRRUS CONTINUES AND SUBSIDENCE ALOFT CONTINUES
TO SUPPRESS AFTN SHOWER/TSTM DEVELOPMENT.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
FRIDAY NIGHT...UNCERTAINTY EXISTS AS TO WHETHER FORCING AND DEEPER
LOW LEVEL THETA-E AIR ASSOCIATED WITH A WARM FRONT OVER THE DEEP
SOUTH ATTM WILL MAKE IT INTO THE AREA THIS EARLY...WITH THE GFS
FASTER AND THE ECMWF DELAYED UNTIL SAT AFTERNOON. DECIDED TO LEAN
SLIGHTLY IN FAVOR OF THE GFS...WITH DRY CONDS THE FIRST HALF OF FRI
NIGHT...AND LOW CHANCE POP FROM NYC WEST LATE AT NIGHT.
SATURDAY AND SUNDAY...HIGHER CONFIDENCE ON A VERY WARM...MOIST AND
INCREASINGLY UNSTABLE MARITIME TROPICAL AIR MASS MOVING IN AS
ISENTROPIC LIFT INCREASES BASED ON A DEPARTING OFFSHORE HIGH.
ALTHOUGH HIGH TEMPS ARE FORECAST TO RANGE FROM 85-90 BOTH DAYS
BECAUSE OF INCREASED CLOUD COVER...DEWPOINTS RISING INTO THE MID 60S
ON SAT AND LOWER 70S ON SUNDAY WILL MAKE IT FEEL UNCOMFORTABLE...
WITH MAX HEAT INDICES NEAR 90 ON SATURDAY AND MID 90S ON SUNDAY.
CHANCES FOR SHOWERS AND TSTMS WILL INCREASE WITH THE PASSAGE OF A
WARM FRONT ON SAT...THEN ALSO INTO SUNDAY WITH A WEAK SFC TROUGH
REMAINING NEARBY AND AS UPPER LEVEL DISTURBANCES RIDE AROUND AN
UPPER RIDGE TO THE SOUTH. THERE IS A CHC THAT CONVECTION THAT
DEVELOPS COULD PRODUCE TORRENTIAL RAIN AND FLASH FLOODING. STAY
TUNED.
MONDAY...THREAT OF ADDITIONAL SCT HVY SHOWERS AND TSTMS SHOULD
CONTINUE AS ADDITIONAL UPPER LVL SHORT WAVES APPROACH...WITH MAX
TEMPS IN THE LOWER 90S AND AND MAX HEAT INDICES IN THE MID AND UPPER
90S.
TUESDAY AND WEDNESDAY...FAIR AS HIGH PRESSURE BUILDS EAST.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
VFR THROUGH THE PERIOD WITH HIGH PRESSURE OVER THE REGION AND LOW
PRESSURE MOVING TO THE SOUTH AND EAST.
THERE MAY BE SOME BRIEF SUB-VFR CONDITIONS AT KGON WHERE SOME FOG
OVER THE WATER MAY SPREAD INTO THE TERMINAL.
LIGHT AND VRB FLOW BECOMES ENE THIS MORNING. SEA BREEZES ALONG
THE COAST WILL DEVELOP AND CAUSE WINDS TO VEER SE TO S BY THIS
AFTERNOON. TIMING OF THE WIND SHIFT IS LIKELY PLUS OR MINUS 1 HOUR
WITH HIGH CONFIDENCE IN THE OVERALL WIND FORECAST.
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)
KEWR FCSTER COMMENTS: AMENDMENT MAY BE NEEDED FOR SHIFTING WINDS.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: AMENDMENT MAY BE NEEDED FOR SHIFTING WINDS.
KLGA FCSTER COMMENTS: AMENDMENT MAY BE NEEDED FOR SHIFTING WINDS.
KTEB FCSTER COMMENTS: AMENDMENT MAY BE NEEDED FOR SHIFTING WINDS.
KPHN FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KISP FCSTER COMMENTS: AMENDMENT MAY BE NEEDED FOR SHIFTING WINDS.
OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
.FRIDAY-FRIDAY NIGHT...VFR.
.SATURDAY-MONDAY...MVFR POSSIBLE IN ISO-SCT SHRA/TSRA.
&&
.MARINE...
MARINE FORECAST ON TRACK. SUB SMALL CRAFT CONDITIONS ARE
FORECAST TO CONTINUE THROUGH SUNDAY. SEAS ON THE OCEAN THIS
MORNING ARE AROUND 4 FT...BUT THESE ARE EXPECTED TO SLOWLY SUBSIDE
BY FRIDAY AND CONTINUE IN THE 2-3 FT RANGE THROUGH THE WEEKEND.
LIGHT WINDS WILL INCREASE TO AROUND 10 KT IN THE AFTERNOONS WITH
SEA BREEZE CIRCULATIONS.
COMBINED WIND WAVES FROM SW WINDS 10-15 KT AND INCOMING SE SWELLS
SHOULD BUILD SEAS UP TO 4 FT FOR A TIME SUNDAY NIGHT...JUST BELOW
SCA LEVELS.
&&
.HYDROLOGY...
NO RAINFALL IS EXPECTED THROUGH FRIDAY.
MULTIPLE ROUNDS OF SCT HVY SHOWERS AND TSTMS ARE POSSIBLE AS EARLY
AS FRIDAY NIGHT...BUT MORE LIKELY LATE SAT THROUGH MON. THIS IS
DUE TO AN APPROACHING WARM FRONT FRIDAY NIGHT INTO SATURDAY NIGHT
AND THE PASSAGE OF AN UPPER LEVEL DISTURBANCES SUNDAY/MONDAY.
HOURLY RAINFALL RATES COULD EXCEED 1 INCH PER HOUR AND CAUSE
LOCAL FLASH FLOODING AS PRECIPITABLE WATER VALUES RISE TO OVER 2
INCHES. MESO BETA ELEMENT / CORFIDI VECTORS OF 10 KT OR LESS
SUGGEST SLOW MOVING CONVECTIVE CLUSTERS AND POTENTIAL FOR URBAN
FLASH FLOODING.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JST
NEAR TERM...MPS
SHORT TERM...JST
LONG TERM...GOODMAN
AVIATION...BC/SEARS
MARINE...GOODMAN/JST
HYDROLOGY...GOODMAN/JST
AREA FORECAST DISCUSSION
NWS MIAMI FL
203 AM EDT THU JUL 12 2012
.AVIATION...
FOR THE SHORT TERM...THE MOST ACTIVE AREA WITH CONVECTION IS OVER
THE GULF WATERS TO THE WEST OF TERMINAL KAPF WHICH WAS ASSIGNED
VCSH AT 06Z BUT COULD BE AMENDED TO VCTS IF THE THUNDERSTORMS
BECOME MORE ACTIVE IN THIS AREA. TERMINAL KAPF COULD ALSO HAVE
PERIODS OF SUB-VFR TO BRIEF PERIODS OF IFR CONDITIONS THE NEXT
COUPLE OF HOURS WITH ANY HEAVY SHOWERS AND/OR THUNDERSTORMS. ALL
EAST COAST TERMINALS HAVE BEEN ASSIGNED VCSH AT 06Z WITH ONLY
ISOLATED SHOWERS OVER THE ATLANTIC WATERS AT THE MOMENT.
HOWEVER...THERE IS A PERSIST LOW LEVEL TO MIDDLE LEVEL TROUGH
ACROSS THE REGION WITH A CHANCE OF SHOWERS AND/OR THUNDERSTORMS
INCREASING ACROSS THE REGION EARLY THIS MORNING. EAST COAST
TERMINALS EXPECTED TO HAVE MAINLY VFR CONDITIONS WITH BRIEF
PERIODS OF SUB-VFR CONDITIONS WITH OCCURRENCE OF SHOWERS OR
ISOLATED THUNDERSTORMS.
60
&&
.PREV DISCUSSION... /ISSUED 859 PM EDT WED JUL 11 2012/
UPDATE...SATELLITE IMAGERY TODAY SHOWED A VERY NICE SPIN OVER
SOUTH FL. THE EVENING MIAMI SOUNDING SHOWED THE DRAMATIC SWITCH IN
THE LOW/MID LEVEL WIND FIELD ASSOCIATED WITH THIS LOW TO MID LEVEL
LOW CENTER WITH WINDS YESTERDAY EVENING SOUTHEAST, THIS MORNING
SOUTH, AND THIS EVENING DUE WESTERLY. THIS SPIN NOW LOOKS TO BE
OVER THE PALM BEACH COUNTY COAST. MODELS SHOWS THIS LOW STRETCHING
OUT AND EVENTUALLY MOVING SOUTHWEST TOMORROW WITH HIGH PRESSURE
BUILDING IN FROM THE NORTHEAST, BEFORE ANOTHER TROUGH ALOFT MOVES
ACROSS SOUTH FL FROM THE WEST OVER THE WEEKEND. MOISTURE WILL ONLY
GRADUALLY DECREASE TONIGHT-THU. FOR TONIGHT, WITH LESSER
CONVERGENCE, WE EXPECT MUCH LESS ACTIVITY THAN OCCURRED LAST
NIGHT. THE HRRR SHOWS ACTIVITY DEVELOPING OVER THE ATLANTIC, BUT
KEEPS IT MAINLY OFF THE COAST DUE TO THE WESTERLY STEERING
FLOW. HOWEVER, WINDS ARE STILL ONSHORE UP THROUGH 3K FT...SO THERE
COULD BE SOME ATLANTIC COASTAL CONVERGENCE SETTING UP. HAVE GONE
WITH 20 POPS INTERIOR/GULF COAST AND 30 POPS ALONG THE ATLANTIC
COAST. /GREGORIA
PREV DISCUSSION... /ISSUED 812 PM EDT WED JUL 11 2012/
AVIATION...
THE LATEST WRF AND HRRR MODEL REFLECTIVITIES INDICATE THE BEST
CHANCE FOR OVERNIGHT SHOWERS REMAINING OVER THE ADJACENT ATLANTIC
WATERS AND ALONG THE EAST COAST LOCATIONS. THE LOCALLY RUN WRF
INDICATED THE BEST COVERAGE SETTING UP ALONG THE EAST COAST AROUND
9-10Z. HOWEVER...NOT CONFIDENT ENOUGH AT THIS TIME TO INCLUDE VCSH
THROUGH THESE OVERNIGHT HOURS AND WILL UPDATE AS NECESSARY. WINDS
WILL REMAIN LIGHT OUT OF THE SE THROUGH THE NIGHT ALONG THE EAST
COAST AND MAY BECOME LIGHT AND VARIABLE INLAND AND AT APF.
SCATTERED SHOWERS/TSTMS WILL BE POSSIBLE ONCE AGAIN THROUGH THE
DAY TOMORROW. 85/AG
PREV DISCUSSION... /ISSUED 227 PM EDT WED JUL 11 2012/
DISCUSSION...LATE NIGHT/EARLY MORNING WIDESPREAD CONVECTION
SLOWLY ERODING. APPEARS TO BE SEVERAL CONTRIBUTING FACTORS AS TO
THE CAUSE OF THIS OUTBREAK, BUT AT ANY RATE THE MODELS WERE
CLUELESS. IN FACT, THE SHORT TERM MODELS SUCH AS THE RAPID REFRESH
DID NOT RECOGNIZE ANYTHING WAS OCCURRING AND NEITHER THE GFS NOR
THE NAM FORECASTED WELL WITH ONLY ISOLD POPS. OF COURSE, THE
PERSISTENT DEEP EAST TO SOUTHEAST WIND FLOW WAS A MAJOR PLAYER
ALONG WITH ABOVE AVERAGE PWAT VALUES. THIS ALL INTERACTED WITH A
TROF NOW IN THE EASTERN GULF BUT EXTENDS FROM THE SFC TO 70H, SOME
WEAK UPPER LEVEL DIVERGENCE, AND SOME WEAK SFC CONVERGENCE THAT
SET UP ALONG THE SE CST AS AN OUTFLOW BOUNDARY MOVED OFFSHORE
AROUND 06-07Z AND INTERACTED WITH THE CONVECTION MOVING ONSHORE.
HAVING SAID ALL OF THIS, THE VERY SHORT TERM FCST FOR THE
REMAINDER OF THIS AFTERNOON INTO THE EVENING IS HIGHLY UNCERTAIN.
THE QUESTION IS JUST HOW MUCH CAN THE ATMOSPHERE RECOVER FROM THE
RAIN COOLED AIR MASS UNDER PLACE EVEN THOUGH VISIBLE SATELLITE
SHOWS THE CLOUDS NOW RAPIDLY CLEARING. IN FACT, EVEN THE AREAS OF
OUR NW INTERIOR HAVE BEEN SUNNY BUT THEY ALSO MAY REMAIN UNDER SOME
SORT OF SUBSIDENCE INHIBITING ANY DEEP CONVECTION. BUT CURRENT
PLAN IS TO STILL INDICATE LATE AFTERNOON ACTIVITY IN THOSE AREAS
AS ISOLD CONVECTION CURRENTLY BEGINNING TO BUILD SOUTH INTO
COLLIER COUNTY AS OF THIS WRITING.
THE DEEP EAST FLOW WILL CONTINUE THROUGH THE SHORT TERM AS A RIDGE
BOTH AT MID LEVELS AND AT THE SFC REMAINS ACROSS N FL AND STRETCHING
INTO THE ATLANTIC. SO ALSO WILL CONTINUE TO GO ABOVE POP GUIDANCE AS
BOTH THE MET AND MAV HAVE BEEN RUNNING ON THE LOW SIDE, ESPECIALLY
THIS MORNING. THERE IS ALSO A TUTT LIKE FEATURE THAT IS SLOWLY
DRIFTING WEST OVER THE ATLANTIC NORTH OF THE BAHAMAS AND THIS WILL
LIKELY BE APPROACHING THE PENINSULA LATE IN THE WEEK OR EARLY THIS
WEEKEND. A DRY SLOT ON THE WESTERN PERIPHERY OF THE TROF COULD LOWER
CONVECTIVE ACTIVITY TEMPORARILY BUT THEN AS THE TROF CONTINUES INTO
THE GULF, HIGH PWAT`S WILL AGAIN MOVE OVER THE AREA. SO BASICALLY,
IT APPEARS THAT AN UNSETTLED WX PATTERN WILL CONTINUE FOR AT LEAST
THE NEXT FEW DAYS.
IN THE EXTENDED PERIOD FOR THE WEEKEND INTO EARLY NEXT WEEK, THE
DEEP LAYER RIDGE WILL GRADUALLY SHIFT BACK TO THE SOUTH EARLY NEXT
WEEK. THIS WILL ALLOW FOR THE EAST FLOW TO WEAKEN AND CONVECTION
WILL BE DRIVEN MORE BY SEA BREEZE BOUNDARIES AND GO BACK TO THE MORE
PRONOUNCED AFTERNOON/EARLY EVENING VARIETY CONVECTION OVER THE MAINLAND.
MARINE...OUTSIDE OF SHOWERS AND THUNDERSTORMS, WINDS WILL BE EAST
TO SOUTHEAST AT 15 KT OR LESS. THIS WILL KEEP SEAS BELOW ADVISORY
CRITERIA BUT THERE COULD BE SOME LOCALLY ROUGH SEAS NEAR THE
STRONGER STORMS ESPECIALLY THROUGH FRIDAY.
FIRE WEATHER...NO PROBLEMS OR CONCERNS WITH AMPLE TROPICAL
MOISTURE REMAINING IN PLACE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 88 77 89 78 / 40 30 40 20
FORT LAUDERDALE 89 79 89 79 / 40 30 40 20
MIAMI 90 77 89 78 / 50 30 40 20
NAPLES 89 75 91 75 / 50 30 50 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...14/MJB
AVIATION/RADAR...60/BD
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
218 AM EDT THU JUL 12 2012
.SYNOPSIS...
A FRONT WILL REMAIN DRAPED ACROSS THE CENTRAL CAROLINAS THROUGH
FRIDAY BEFORE LIFTING NORTH AS ATLANTIC HIGH PRESSURE EXTENDS
ACROSS THE SOUTHEAST STATES THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
A VERY MUGGY LOW-LEVEL AIRMASS IN PLACE WITH PRECIPITABLE WATER OF
2.19 INCHES ON OUR 00Z SOUNDING. A LOT OF INTERESTING BOUNDARIES
ARE SHOWING UP ON OUR RADAR EARLY THIS MORNING. THE MOST
PRONOUNCED IS A NEARLY LINEAR CONVERGENCE AXIS ABOUT A MILE OFF
OUR COASTLINE MOVING SLOWLY TOWARD LAND. THE OTHER IS A FINE LINE
MOVING INTO NORTHWEST BERKELEY AND DORCHESTER COUNTIES...
APPARENTLY A CONVECTIVE OUTFLOW FROM EARLIER THAT JUST RECENTLY
BECAME VISIBLE ON RADAR. A COUPLE SHOWERS HAVE RECENTLY DEVELOPED
ALONG THIS LATTER BOUNDARY AS IT MOVES SLOWLY EAST TOWARD
SUMMERVILLE AND THE WESTERN EDGE OF LAKE MOULTRIE. IT WILL BE
INTERESTING TO WATCH WHAT HAPPENS WHEN THIS WESTERN BOUNDARY
EVENTUALLY CONVERGES WITH THE MARITIME CONVERGENCE AXIS IN A FEW
HOURS. THE LATEST HRRR SHOWS QUITE A BIT OF CONVECTIVE DEVELOP
ALONG THE SC/GA COAST IN ASSOCIATION WITH THE INCOMING MOISTURE
CONVERGENCE. THE BEST COVERAGE SHOULD BE ACROSS THE TRI-COUNTY
AREA WHERE MULTIPLE BOUNDARIES COLLIDE. WE BUMPED POPS UP A BIT
FOR THE REMAINDER OF THE NIGHT WITH 30-40 POPS IN THE TRI-COUNTY
AND 20-30 ALONG THE COAST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/...
THURSDAY...A WEAK FRONT WILL MEANDER JUST TO THE NORTH/NORTHWEST
ACROSS THE CENTRAL CAROLINAS...WHILE A SUBTLE SURFACE TROUGH LINGERS
ALONG THE COASTLINE. MODEL FORECAST SOUNDINGS INDICATE PWAT VALUES
REMAINING NEAR 2 INCHES...INDICATIVE OF ABUNDANT DEEP MOISTURE
ACROSS THE REGION. ISOLATED SHOWERS AND THUNDERSTORMS COULD PERSIST
ALONG THE IMMEDIATE COASTLINE DURING THE MORNING HOURS WITHIN
INITIALLY BETTER INSTABILITY AND CONVERGENCE FOUND OVER THE WATERS
AND ADJACENT LAND AREAS. AS HEATING AND INSTABILITY INCREASE INLAND
BY LATE MORNING...EXPECT CONVECTIVE COVERAGE TO ALSO INCREASE ACROSS
THE FORECAST AREA AS THE AFTERNOON PROGRESSES. GIVEN THE LINGERING
FRONT TO THE NORTHWEST...AS WELL AS ABUNDANT RESIDUAL MESOSCALE
BOUNDARIES FROM EARLIER SHOWER/THUNDERSTORM ACTIVITY...THERE WILL BE
SUFFICIENT MOISTURE AND FORCING TO SUPPORT POPS IN THE 40 TO 50
PERCENT RANGE ALONG AND AHEAD OF THE INLAND-PROGRESSING SEABREEZE.
GFS AND NAM INSTABILITY PARAMETERS ARE SLIGHTLY LOWER THAN
FORECASTED FOR WEDNESDAY AFTERNOON...AND LACKING ANY NOTABLE UPPER
LEVEL SUPPORT...ANY ISOLATED STRONG TO SEVERE THUNDERSTORMS WILL
MAINLY BE THE RESULT OF BOUNDARY COLLISIONS. TEMPERATURES WILL RISE
INTO THE UPPER 80S NORTH TO THE LOWER 90S SOUTHEAST GEORGIA UNDER A
BUILDING RIDGE OF HIGH PRESSURE.
EXPECT ISOLATED TO SCATTERED CONVECTION OVER LAND AREAS TO
DECREASE IN COVERAGE AS HEATING/INSTABILITY WANES AFTER SUNSET.
BEST INSTABILITY WILL THEN TRANSITION TO THE WATERS AND IMMEDIATE
COASTLINE...WHERE A SLIGHT CHANCE OF SHOWER/THUNDERSTORMS WILL
PERSIST AFTER MIDNIGHT.
FRIDAY AND SATURDAY...THE WEAKENING FRONT ACROSS THE CAROLINAS
WILL DISSIPATE AND/OR LIFT NORTHWARD ON FRIDAY...WITH ATLANTIC HIGH
PRESSURE AT THE SURFACE AND ALOFT STRENGTHENING ACROSS THE
SOUTHEAST STATES INTO THE WEEKEND. ISOLATED TO SCATTERED CONVECTION
WILL LIKELY BE DRIVEN BY SEABREEZE CONVERGENCE AND MESOSCALE
BOUNDARY INTERACTIONS...MAINLY OCCURRING DURING THE FAVORED
AFTERNOON/EARLY EVENING HOURS OF MAXIMUM HEATING AND INSTABILITY.
WITHIN THIS MORE SEASONAL PATTERN...HIGH TEMPERATURES WILL REACH
THE UPPER 80S TO LOWER 90S AWAY FROM THE LOCALLY COOLER COASTLINE
EACH AFTERNOON...WITH LOW TEMPERATURES IN THE 70S EACH NIGHT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
A DEEP LAYER OF ATLANTIC HIGH PRESSURE IS EXPECTED TO REMAIN
CENTERED JUST NORTH OF THE REGION THROUGH AT LEAST MONDAY...WITH
DEEP EAST/SOUTHEAST FLOW. MODELS INDICATING RATHER MARGINAL DEEP
LAYER MOISTURE...WITH MEAN RH VALUES BELOW 60 PERCENT THROUGH MONDAY.
THUS...HAVE KEPT SLIGHT CHANCE POPS...ESPECIALLY AWAY FROM THE COAST
EACH AFTERNOON. TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE NORMAL.
BY TUESDAY AND WEDNESDAY...GLOBAL MODELS BEGIN TO DIVERGE ON THE
LARGE SCALE. THE CONSENSUS OF THE SOLUTIONS SEEMS TO POINT TOWARD A
MID AND UPPER LEVEL TROUGH DEVELOPING OVER THE MID
ATLANTIC...STRETCHING SOUTHWARD INTO INTERIOR SOUTH CAROLINA AND
GEORGIA. IF THIS OCCURS...THE MEAN LOW LEVEL FLOW SHOULD TURN MORE
SOUTHERLY AND PRECIP CHANCES SHOULD INCREASE. FOR NOW...HAVE GONE
WITH SLIGHT CHANCE POPS. HOWEVER...IF THE MODELS CONTINUE TO TREND
TOWARD A LARGE SCALE TROUGH OVER THE INTERIOR...POPS WILL NEED TO BE
RAISED. TEMPERATURES ARE EXPECTED TO REMAIN NEAR NORMAL.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
A SOUPY AIRMASS REMAINS IN PLACE AND SEVERAL CONVECTIVE OUTFLOW
BOUNDARIES WILL SOON COLLIDE ACROSS THE KCHS TERMINAL SO WE HAVE
VICINITY SHOWERS THROUGH DAYBREAK. RECENT CLEARING OF MID AND HIGH
CLOUDS COULD BE THE EXPLANATION FOR RECENT BKN003 CEILING AT CHS.
NOT SURE IF LIFR CONDITIONS WILL CONTINUE MUCH LONGER AS SHOWERS
MOVE IN FROM THE WEST...BUT MVFR COULD VERY POSSIBLY PERSIST
THROUGH DAYBREAK.
CONVECTION WILL PROBABLY GO UP LATE THIS MORNING AT EITHER
TERMINAL ALONG THE SEABREEZE. HARD TO NARROW DOWN THE WINDOW OF
OPPORTUNITY TO LESS THAN 6 HRS SO WE JUST MAINTAINED THE VICINITY
TSTMS AT BOTH SITES FOR MUCH OF THE AFTERNOON. MOST OF THE
CONVECTION SHOULD BE THROUGH BY LATE AFTERNOON WITH DIMINISHING
CHANCES THEREAFTER.
EXTENDED AVIATION OUTLOOK...THERE WILL BE A SMALL CHANCE FOR
MVFR/IFR CONDITIONS IN MAINLY AFTERNOON/EVENING SHOWERS/THUNDERSTORMS
FRIDAY. EXPECT DECREASING CHANCES FOR CONVECTION OVER THE
WEEKEND...WITH VFR CONDITIONS PREVAILING.
&&
.MARINE...
A DEEP LAYER ATLANTIC HIGH PRESSURE SYSTEM IS EXPECTED TO BE
CENTERED NORTH OF THE REGION THROUGH THE PERIOD. THIS WILL RESULT
IN EAST/SOUTHEAST WINDS OF GENERALLY 15 KT OR LESS...AND SEAS 3
TO 4 FEET OR LESS. WINDS COULD BECOME A LITTLE STRONGER EACH
AFTERNOON NEAR THE COAST WITH THE SEA BREEZE...BUT ARE EXPECTED TO
REMAIN BELOW ADVISORY LEVELS. GENERALLY LATE NIGHT AND MORNING
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL PREVAIL.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...JRL
SHORT TERM...79
LONG TERM...RFM
AVIATION...JRL/79
MARINE...
AREA FORECAST DISCUSSION
NWS GOODLAND KS
457 PM MDT THU JUL 12 2012
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 146 PM MDT THU JUL 12 2012
SURFACE TROUGH IS STARTING TO PUSH INTO THE WESTERN PORTION OF
THE AREA WITH A SHORTWAVE MOVING OVER THE TOP OF IT BEGINNING THIS
AFTERNOON. DECENT SURFACE CONVERGENCE ALONG IT WITH LITTLE TO NO
INHIBITION. SO DO EXPECT THUNDERSTORMS TO DEVELOP BUT HOW FAR EAST
TO TAKE THEM IS A QUESTION. STORM MOVEMENTS NEAR 15 KNOTS SO THEY
SHOULD MAKE SOME PROGRESS. EARLIER MODEL OUTPUT WAS NOT TOTALLY
EXCITED ABOUT GENERATING PRECIPITATION ACROSS CWA THROUGH TONIGHT.
HOWEVER...THE LATEST HRRR IS GENERATING SOME LIGHT QPF.
WITH THE AMOUNT OF INSTABILITY AND LIFT BELIEVE THERE IS ENOUGH
THERE TO HAVE A SLIGHT CHANCE THROUGH THE ENTIRE NIGHT. SO GRIDS
WERE ADJUSTED ACCORDINGLY THROUGH TONIGHT. WINDS LOOK TO BECOME
LIGHT AND CLOUDS DECREASE AFTER WHATEVER CONVECTION THERE IS IS
DONE. DEPENDING ON HOW LOW THE DEWPOINTS ARE...TEMPERATURES COULD
DROP A LITTLE...ESPECIALLY IN THE WEST. LOOK TO HAVE PLENTY OF SUN
TOMORROW WITH MODELS SHOWING A RATHER CHAOTIC WIND FIELD...MOSTLY
FROM AN EASTERLY DIRECTION. NAM 2M/NWP HAS BEEN DOING WELL IN THIS
HOT PATTERN AND THINK IT IS ON THE RIGHT TRACK. GFS STILL LOOKS TOO
MOIST AND COOL IN THE LOWER LEVELS. SO BASED ON THE NAM 2M/NWP AND
850 MB TEMPERATURE CONCENSUS...RAISED MAXES FOR FRIDAY TO NEAR 100
FOR MANY LOCATIONS. MUCH WARMER AND DRIER AT MID LEVELS LOOKS TO
KEEP IT DRY TOMORROW AS WELL.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 240 PM MDT THU JUL 12 2012
AT THE START OF THE EXTENDED PERIOD...THE UPPER HIGH NOW OVER UTAH
WILL HAVE MIGRATED TO THE CO-NM AREA AS THE LARGE SCALE UPPER TROUGH
BECOMES ESTABLISHED IN THE WEST. THE UPPER HIGH WILL BE THE
DOMINANT PLAYER IN OUR WEATHER AS IT STALLS OVER THE CENTRAL PLAINS
EARLY NEXT WEEK. WITH WEAK FLOW ALOFT AND LACK OF SURFACE FEATURES
TO FOCUS CONVECTION...THUNDERSTORM POTENTIAL DURING THIS PERIOD WILL
BE ISOLATED AT BEST. BOTH THE GFS AND ECMWF SUGGEST THE POTENTIAL
FOR INCREASING THUNDERSTORM COVERAGE IN DAYS 6 AND 7 AS A CANADIAN
SURFACE HIGH BUILDS SOUTH AND STALLS CLOSE TO OUR FORECAST AREA. IF
THIS SCENARIO DOES UNFOLD THEN POPS IN THE FAR EXTENDED PERIODS WILL
NEED TO BE ADJUSTED UPWARD.
DAY-TO-DAY TEMPERATURE CHANGES ARE EXPECTED TO BE INSIGNIFICANT.
MODELS FORECAST 850 TEMPS AROUND 30-32C THROUGH THE PERIOD WHICH
WILL TRANSLATE TO HIGHS IN THE MID 90S TO NEAR 100 DEGREES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 448 PM MDT THU JUL 12 2012
A WEAK SURFACE TROUGH NEAR KGLD AND KMCK HAS BEEN THE FOCUS FOR
ISOLATED THUNDERSTORMS OVER THE LAST FEW HOURS. CHANCES OF A STORM
TO AFFECT KGLD AND KMCK WILL BE LOW. EXPECT SOME SCATTERED CLOUDS
AROUND 12KFT AND LIGHT SOUTHEAST WIND FOR THE NEXT 24 HOURS AS
HIGH PRESSURE ALOFT CONTINUES OVER THE ROCKIES.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...DLF
AVIATION...FS
AREA FORECAST DISCUSSION...CORRECTED SHORT TERM
NWS GOODLAND KS
240 PM MDT THU JUL 12 2012
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 146 PM MDT THU JUL 12 2012
SURFACE TROUGH IS STARTING TO PUSH INTO THE WESTERN PORTION OF
THE AREA WITH A SHORTWAVE MOVING OVER THE TOP OF IT BEGINNING THIS
AFTERNOON. DECENT SURFACE CONVERGENCE ALONG IT WITH LITTLE TO NO
INHIBITION. SO DO EXPECT THUNDERSTORMS TO DEVELOP BUT HOW FAR EAST
TO TAKE THEM IS A QUESTION. STORM MOVEMENTS NEAR 15 KNOTS SO THEY
SHOULD MAKE SOME PROGRESS. EARLIER MODEL OUTPUT WAS NOT TOTALLY
EXCITED ABOUT GENERATING PRECIPITATION ACROSS CWA THROUGH TONIGHT.
HOWEVER...THE LATEST HRRR IS GENERATING SOME LIGHT QPF.
WITH THE AMOUNT OF INSTABILITY AND LIFT BELIEVE THERE IS ENOUGH
THERE TO HAVE A SLIGHT CHANCE THROUGH THE ENTIRE NIGHT. SO GRIDS
WERE ADJUSTED ACCORDINGLY THROUGH TONIGHT. WINDS LOOK TO BECOME
LIGHT AND CLOUDS DECREASE AFTER WHATEVER CONVECTION THERE IS IS
DONE. DEPENDING ON HOW LOW THE DEWPOINTS ARE...TEMPERATURES COULD
DROP A LITTLE...ESPECIALLY IN THE WEST. LOOK TO HAVE PLENTY OF SUN
TOMORROW WITH MODELS SHOWING A RATHER CHAOTIC WIND FIELD...MOSTLY
FROM AN EASTERLY DIRECTION. NAM 2M/NWP HAS BEEN DOING WELL IN THIS
HOT PATTERN AND THINK IT IS ON THE RIGHT TRACK. GFS STILL LOOKS TOO
MOIST AND COOL IN THE LOWER LEVELS. SO BASED ON THE NAM 2M/NWP AND
850 MB TEMPERATURE CONCENSUS...RAISED MAXES FOR FRIDAY TO NEAR 100
FOR MANY LOCATIONS. MUCH WARMER AND DRIER AT MID LEVELS LOOKS TO
KEEP IT DRY TOMORROW AS WELL.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 240 PM MDT THU JUL 12 2012
AT THE START OF THE EXTENDED PERIOD...THE UPPER HIGH NOW OVER UTAH
WILL HAVE MIGRATED TO THE CO-NM AREA AS THE LARGE SCALE UPPER TROUGH
BECOMES ESTABLISHED IN THE WEST. THE UPPER HIGH WILL BE THE
DOMINANT PLAYER IN OUR WEATHER AS IT STALLS OVER THE CENTRAL PLAINS
EARLY NEXT WEEK. WITH WEAK FLOW ALOFT AND LACK OF SURFACE FEATURES
TO FOCUS CONVECTION...THUNDERSTORM POTENTIAL DURING THIS PERIOD WILL
BE ISOLATED AT BEST. BOTH THE GFS AND ECMWF SUGGEST THE POTENTIAL
FOR INCREASING THUNDERSTORM COVERAGE IN DAYS 6 AND 7 AS A CANADIAN
SURFACE HIGH BUILDS SOUTH AND STALLS CLOSE TO OUR FORECAST AREA. IF
THIS SCENARIO DOES UNFOLD THEN POPS IN THE FAR EXTENDED PERIODS WILL
NEED TO BE ADJUSTED UPWARD.
DAY-TO-DAY TEMPERATURE CHANGES ARE EXPECTED TO BE INSIGNIFICANT.
MODELS FORECAST 850 TEMPS AROUND 30-32C THROUGH THE PERIOD WHICH
WILL TRANSLATE TO HIGHS IN THE MID 90S TO NEAR 100 DEGREES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1139 AM MDT THU JUL 12 2012
WEAK SURFACE TROUGH/COLD FRONT WILL PUSH INTO THE AREA LATE THIS
AFTERNOON INTO TONIGHT. THIS COMBINED WITH AN UPPER LEVEL
SHORTWAVE WILL CREATE THE POSSIBILITY OF ISOLATED THUNDERSTORMS
NEAR BOTH TAF SITES AFTER 00Z. DUE TO ISOLATED COVERAGE AND
UNCERTAINTY ON MOST LIKELY AREA OF INITIATION...COVERED THAT
POSSIBILITY WITH VCTS. DO NOT EXPECTED ANY SUB VFR CONDITIONS AT
THIS TIME.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...DLF
AVIATION...BULLER
AREA FORECAST DISCUSSION...CORRECTED SHORT TERM
NWS GOODLAND KS
155 PM MDT THU JUL 12 2012
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 146 PM MDT THU JUL 12 2012
SURFACE TROUGH IS STARTING TO PUSH INTO THE WESTERN PORTION OF
THE AREA WITH A SHORTWAVE MOVING OVER THE TOP OF IT BEGINNING THIS
AFTERNOON. DECENT SURFACE CONVERGENCE ALONG IT WITH LITTLE TO NO
INHIBITION. SO DO EXPECT THUNDERSTORMS TO DEVELOP BUT HOW FAR EAST
TO TAKE THEM IS A QUESTION. STORM MOVEMENTS NEAR 15 KNOTS SO THEY
SHOULD MAKE SOME PROGRESS. EARLIER MODEL OUTPUT WAS NOT TOTALLY
EXCITED ABOUT GENERATING PRECIPITATION ACROSS CWA THROUGH TONIGHT.
HOWEVER...THE LATEST HRRR IS GENERATING SOME LIGHT QPF.
WITH THE AMOUNT OF INSTABILITY AND LIFT BELIEVE THERE IS ENOUGH
THERE TO HAVE A SLIGHT CHANCE THROUGH THE ENTIRE NIGHT. SO GRIDS
WERE ADJUSTED ACCORDINGLY THROUGH TONIGHT. WINDS LOOK TO BECOME
LIGHT AND CLOUDS DECREASE AFTER WHATEVER CONVECTION THERE IS IS
DONE. DEPENDING ON HOW LOW THE DEWPOINTS ARE...TEMPERATURES COULD
DROP A LITTLE...ESPECIALLY IN THE WEST. LOOK TO HAVE PLENTY OF SUN
TOMORROW WITH MODELS SHOWING A RATHER CHAOTIC WIND FIELD...MOSTLY
FROM AN EASTERLY DIRECTION. NAM 2M/NWP HAS BEEN DOING WELL IN THIS
HOT PATTERN AND THINK IT IS ON THE RIGHT TRACK. GFS STILL LOOKS TOO
MOIST AND COOL IN THE LOWER LEVELS. SO BASED ON THE NAM 2M/NWP AND
850 MB TEMPERATURE CONCENSUS...RAISED MAXES FOR FRIDAY TO NEAR 100
FOR MANY LOCATIONS. MUCH WARMER AND DRIER AT MID LEVELS LOOKS TO
KEEP IT DRY TOMORROW AS WELL.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 533 AM MDT THU JUL 12 2012
A FAIRLY STAGNANT PATTERN IS EXPECTED FOR THE EXTENDED FORECAST AS
THE CURRENT RIDGE BECOMES PARKED OVER THE CENTRAL AND SOUTHERN PLAINS WITH
A DEEP LATER TROUGH OVER THE WESTERN THIRD OF THE CONUS. AS SUCH DAY TO
DAY HIGH TEMPS ARE EXPECTED IN THE UPPER 90S TO AROUND 100 DEGREES
WITH GENERALLY SOUTHERLY WINDS AND ONLY SMALL CHANCES FOR PRECIP.
THE MID- AND UPR-LVL FLOW PATTERN WILL ALLOW FOR A CHANNEL OF RICHER
MOISTURE TO STREAM NORTH INTO THE CNTRL ROCKIES. THAT SHOULD HELP
FOSTER THE DEVELOP OF DIURNALLY DRIVEN SCATTERED STORMS OVER THE
HIGHER TERRAIN AND THEN POSSIBLY MOVE INTO THE WRN PORTION OF THE
CWA NEARLY EACH LATE AFTERNOON OR EVENING. THEREFORE THE WRN/NWRN
THIRD OF THE CWA STANDS THE BEST CHANCE FOR SCATTERED ACTIVITY THE
WAY THINGS APPEAR AT THIS TIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1139 AM MDT THU JUL 12 2012
WEAK SURFACE TROUGH/COLD FRONT WILL PUSH INTO THE AREA LATE THIS
AFTERNOON INTO TONIGHT. THIS COMBINED WITH AN UPPER LEVEL
SHORTWAVE WILL CREATE THE POSSIBILITY OF ISOLATED THUNDERSTORMS
NEAR BOTH TAF SITES AFTER 00Z. DUE TO ISOLATED COVERAGE AND
UNCERNTAINTY ON MOST LIKELY AREA OF INITIATION...COVERED THAT
POSSIBILITY WITH VCTS. DO NOT EXPECTED ANY SUB VFR CONDITIONS AT
THIS TIME.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...05
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1054 PM MDT WED JUL 11 2012
.SHORT TERM...(THIS AFTERNOON THROUGH THURSDAY)
ISSUED AT 1202 PM MDT WED JUL 11 2012
14Z WATER VAPOR IMAGERY INDICATED LARGE UPPER LEVEL RIDGE IN PLACE
ACROSS THE MUCH OF THE WESTERN CONUS...WITH CENTER OF RIDGE LOCATED
OVER THE FOUR CORNERS. RUC 1.5 PVU ANALYSIS INDICATED SEVERAL SMALL
PV ANOMALIES MOVING AROUND PERIPHERY OF RIDGE INTO THE NORTHERN
PLAINS. 12Z RAOBS CONTINUED THE WARMING/DRYING TREND OBSERVED
YESTERDAY...WITH MOST SIGNIFICANT WARMING NOTED AT DNR AROUND H65.
AT THE SFC...1020MB HIGH WAS IN PLACE ACROSS THE EASTERN CWA WITH
TROUGH EXTENDING SOUTH FROM LOW ACROSS WESTERN NORTH DAKOTA.
PRIMARY FORECAST CONCERNS WILL BE TEMPS AND PRECIP CHANCES TOMORROW.
REST OF TODAY...EXPECT QUIET WEATHER TO CONTINUE THROUGH THE
AFTERNOON AS SFC HIGH SHIFTS EAST AND TROUGH BECOMES ESTABLISHED
ACROSS COLORADO. NET RESULT WILL BE FOR LIGHT WINDS TO CONTINUE
ACROSS THE EASTERN CWA WITH WINDS GRADUALLY SHIFTING TO THE SOUTH
AND INCREASING ACROSS THE WEST. TEMPS SHOULD BE SLIGHTLY WARMER
TODAY THAN YESTERDAY...BUT GIVEN MINIMAL CHANGES OBSERVED ON
SOUNDINGS DO NOT THINK THINGS WILL BE DRASTICALLY DIFFERENT TEMP
WISE. WHILE THERE IS A BIT OF INSTABILITY AND WEAK CINH TODAY...HAVE
DOUBTS THAT ANYTHING WILL DEVELOP GIVING WARMING ALOFT NOTED TO THE
NORTH OF THE AREA AND THINK DRY FORECAST STILL WARRANTED.
TONIGHT-TOMORROW...PV ANOMALY WILL MOVE INTO THE NEB PANHANDLE
THROUGH THE EVENING HOURS...INDUCING AN AREA OF WEAK WARM AIR
ADVECTION ON EDGE OF H7 THERMAL RIDGE. WHILE THERE APPEARS TO BE A
SMALL POCKET OF ELEVATED INSTABILITY IN THIS AREA...ELEVATED CINH
PROFILES REMAIN QUITE STRONG AND HAVE DOUBTS THAT OVERALL WEAK LARGE
SCALE FORCING WILL BE ENOUGH TO INITIATE ANY OVERNIGHT SHOWERS OR
STORMS. PV ANOMALY WILL BE MOVING ACROSS AREA DURING THE EARLY
AFTERNOON ON THURSDAY...WITH SFC FRONT LAGGING WELL BEHIND IT. GIVEN
LIMITED INSTABILITY AND BEST NEAR SFC FORCING ALONG FRONTAL
ZONE...HAVE DOUBTS ABOUT HOW MUCH OF A PRECIP THREAT THERE WILL BE
DURING THE AFTERNOON HOURS. SLOW STORM MOTIONS ALSO MAKE IT DOUBTFUL
THAT ANYTHING INITIATING ALONG THE FRONT WILL MAKE IT FAR INTO THE
CWA BY 00Z. AS A RESULT...HAVE DELAYED PRECIP CHANCES UNTIL AFTER
21Z IN THE NORTH AND REMOVED THEM ELSEWHERE.
FOR TEMPS...EXPECT SOUTHERLY WINDS AND INCREASING TEMPS ALOFT TO
HOLD UP LOWS A FEW DEGREES IN THE WEST...BUT WITH A PERIOD OF LIGHT
AND VARIABLE WINDS EXPECTED IN EASTERN CWA WILL NOT BE SURPRISED TO
SEE TEMPS DIP INTO THE UPPER TO MID 50S IN SOME LOCATIONS. HIGHS
WILL WARM A FEW DEGREES TOMORROW WITH MID AND UPPER 90S EXPECTED
ACROSS ENTIRE AREA.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 245 PM MDT WED JUL 11 2012
LONGER TERM GUIDANCE IS IN FAIRLY GOOD AGREEMENT WITH THE EVOLUTION
OF THE UPPER PATTERN INTO THE WEEKEND. CLOSED UPPER LOW CURRENTLY
OFF THE PACIFIC NORTHWEST COAST IS FORECAST TO MOVE ONSHORE AND
GRADUALLY CARVE OUT A SIGNIFICANT TROUGH OVER THE WESTERN THIRD OF
THE COUNTRY BY FRIDAY. AS THIS OCCURS...THE UPPER HIGH OVER UTAH
WILL SHIFT EAST TO THE PLAINS RESULTING IN A WEAK SOUTHWEST FLOW
ALOFT ACROSS THE CENTRAL HIGH PLAINS. THIS WILL OPEN THE DOOR THIS
WEEKEND FOR THE POSSIBILITY OF AFTERNOON THUNDERSTORMS FORMING OVER
THE HIGHER TERRAIN AND MOVING TOWARD THE FORECAST AREA BY EVENING.
IN THE NEARTERM...AN UPPER TROUGH NOW OVER MONTANA WILL CONTINUE TO
SLOWLY DEEPEN AS IT WORKS TOWARD THE WESTERN GREAT LAKES BY LATE
TOMORROW. THIS FEATURE AND AN ASSOCIATED SURFACE COLD FRONT WILL
RESULT IN THUNDERSTORM FORMATION THURSDAY OVER THE DAKOTAS AND
NEBRASKA WHICH WILL THEN MOVE SOUTH AND SOUTHEAST TOWARD THE
FORECAST AREA THURSDAY NIGHT. STILL SOME UNCERTAINTIES IN TERMS OF
COVERAGE BUT HAVE KEPT POPS GOING THURSDAY NIGHT.
HAVE INCLUDED LOW CHANCES OF EVENING AND OVERNIGHT THUNDERSTORMS
STARTING SATURDAY...MAINLY ACROSS THE WEST AND NORTHWEST...TO COVER
THE POTENTIAL FOR STORMS WORKING OFF THE HIGHER TERRAIN AND
ADVECTING IN. THE ECMWF CONTINUES TO KEEP THINGS DRIER THROUGH THE
EXTENDED PERIOD WHILE THE GFS IS MAYBE TOO AGGRESSIVE WITH PRECIP
CHANCES. CONFIDENCE IN WHICH DAYS HAVE THE BEST POTENTIAL REMAINS
LOW UNTIL IT BECOMES MORE APPARENT HOW THE UPPER PATTERN ULTIMATELY
EVOLVES.
TEMPERATURE GUIDANCE FROM ALL MODELS SUGGESTS A CONTINUATION OF THE
SLOW WARMING TREND INTO THE WEEKEND AS 850 MB TEMPERATURES WARM 2-3
DEGREES EACH DAY THROUGH FRIDAY AND THEN HOLD IN THE 30-32C RANGE
OVER THE WEEKEND. FORECAST AFTERNOON HIGHS WILL THEREFORE TREND
BACK INTO THE 90S TO POSSIBLY NEAR 100...BUT AT THIS TIME IT DOES
NOT APPEAR THAT A REPEAT OF THE RECORD HEAT FROM LATE JUNE WILL
RETURN DURING THIS PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1046 PM MDT WED JUL 11 2012
HIGH PRESSURE ALOFT AND AT THE SURFACE WITH RESULTING SUBSIDENCE
WILL KEEP THUNDERSTORMS OUT OF THE FORECAST FOR KGLD AND KMCK
OVERNIGHT AND THROUGH MOST OF THURSDAY. A WEAK SURFACE TROUGH WILL
MOVE INTO EASTERN COLORADO THURSDAY WITH A SLIGHT CHANCE OF
THUNDERSTORMS NEAR THE TROUGH THURSDAY AFTERNOON AND EVENING.
POINT FORECAST SOUNDINGS SHOW ONLY VERY HIGH BASED MOISTURE AND
INSTABILITY IS LACKING UNTIL AFTER 06Z FRIDAY. CONSEQUENTLY EXPECT
VFR CONDITIONS AT BOTH SITES FOR THE NEXT 24 HOURS WITH LIGHT
SOUTHERLY WIND.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JRM
LONG TERM...DLF
AVIATION...FS
AREA FORECAST DISCUSSION
NWS WICHITA KS
1140 PM CDT WED JUL 11 2012
.AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
AVIATION CONCERNS ARE EXPECTED TO BE NIL THROUGH THIS TAF PERIOD.
THE UPPER WAVE THAT BROUGHT ISOLATED SHOWERS AND STORMS IS NOW
SINKING SOUTH OVER EASTERN OK AND THE OZARK REGION. A FEW SCATTERED
MID CLOUDS MAY LINGER THIS EVENING WITH HIGH CONFIDENCE THAT VFR
CONDITIONS WILL PREVAIL AREA WIDE THROUGH THIS TAF PERIOD. UNLIKE
WED THERE WILL NOT BE ANY FEATURE TO HELP DEVELOP ISOLATED SHOWERS
AND STORMS.
LAWSON
&&
.PREV DISCUSSION... /ISSUED 642 PM CDT WED JUL 11 2012/
AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
VERY LITTLE IN THE WAY OF AVIATION CONCERNS THROUGH THE NEXT 24
HOURS.
THE STORMS THIS AFTERNOON OVER SE KS WERE THE RESULT OF A SLOW
MOVING UPPER WAVE THAT IS EXPECTED TO CONTINUE TRACKING SOUTHEAST
TONIGHT. THE FEW SHOWERS AND STORMS THAT ARE LEFT WILL QUICKLY
DISSIPATE AS SUNSET APPROACHES. THIS WILL LEAVE CLEAR SKIES IN
PLACE. WITHOUT ANY FEATURES TO FOCUS CONVECTION ON...NOT EXPECTING
ANY SHOWERS OR STORMS IN THE AREA FOR THU. THEREFORE CONFIDENCE
REMAINS HIGH THAT VFR CONDITIONS WILL CONTINUE.
LAWSON
PREV DISCUSSION... /ISSUED 255 PM CDT WED JUL 11 2012/
DISCUSSION...
FORECAST CHALLENGE...TEMPERATURES WITH RETURN OF ANOTHER HOT AND
DRY STRETCH OF WEATHER THRU EARLY NEXT WEEK.
TONIGHT-SATURDAY
DIURNAL HEATING HAS PROMOTED AN EXTENSIVE CU FIELD MAINLY
ALONG/EAST OF THE KANSAS TURNPIKE THIS AFTERNOON. SOMEWHAT COOLER
TEMPERATURES WITHIN THE THERMAL TROF ALOFT HAS ALSO RESULTED IN A
BIT MORE INSTABILITY WITH MLCAPE VALUES OF 1000-1500 J/KG. A FEW
ISOLATED SHOWERS HAVE DEVELOPED AND LATEST RUC AND HRRR SUGGEST
THEY WILL CONTINUE THRU THE LATE AFTERNOON...SO WILL CARRY ISOLATED
MENTION UNTIL AROUND 00Z. OTHERWISE TEMPERATURES WILL WARM A BIT
UNDER SUBTLE RIDGING ALOFT INTO THURSDAY...SO EXPECT A BIT LESS
DIURNAL CU AND LITTLE CHANCE FOR MEASURABLE RAIN. AN UPPER
SHORTWAVE TROF IS STILL PROGGED TO DROP SOUTHEAST ACROSS THE
UPPER MIDWEST ON FRIDAY WITH THE TAIL END OF VORTICITY AND UPPER
JET NOSING INTO KANSAS. HOWEVER MODEST MOISTURE AND INSTABILITY
SHOULD MITIGATE OR LIMIT CONVECTIVE CHANCES TO A ROGUE/ISOLATED
NATURE SO WILL KEEP FORECAST DRY FOR NOW. THE UPPER RIDGE WILL
BUILD EAST ACROSS THE HIGH PLAINS FROM FRIDAY INTO SATURDAY WITH
TEMPERATURES CREEPING BACK ABOVE SEASONAL CLIMO AND PERHAPS
APPROACHING THE CENTURY MARK ACROSS CENTRAL KANSAS.
SUNDAY-WEDNESDAY
WHILE THE MEDIUM RANGE GENERALLY SUGGESTS HOT AND DRY CONDITIONS
THRU EARLY NEXT WEEK...SUBTLE VARIANCES IN THE HANDLING OF WEAK
TROUGHINESS WITHIN THE UPPER RIDGE DO POSE SOME CHALLENGES. THIS
IS MAINLY WITHIN THE EASTERLIES MIGRATING UNDER THE RIDGE FROM
THE LOUISIANA/TEXAS GULF COAST PERHAPS ACROSS THE SOUTHERN PLAINS
EARLY NEXT WEEK. THIS COULD TEMPER THE COMING HOT STRETCH AND AT
THE MOMENT IT DOES NOT LOOK AS BRUTAL AS WHAT WE EXPERIENCED IN
LATE JUNE. THAT SAID...MAXS AROUND THE CENTURY MARK AND HEAT
INDICES TO MATCH SEEM VERY REASONABLE AND CLOSE TO THE GOING
FORECAST.
DARMOFAL
AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
QUIET AVIATION WEATHER ANTICIPATED THROUGH AT LEAST THE NEXT 24
HOURS FOR ALL TERMINALS ACROSS CENTRAL...SOUTH-CENTRAL AND
SOUTHEAST KS. LIGHT NORTHEAST SURFACE WINDS WILL TRANSITION TO
LIGHT EAST/SOUTHEASTERLY WINDS TONIGHT...AND VEERING TO MORE
SOUTHERLY AND INCREASING SLIGHTLY AFTER SUNRISE THURSDAY.
AFTERNOON HEATING WILL GIVE WAY TO FEW-SCT DIURNAL CUMULUS AROUND
FROM 6000-9000 FT AGL THIS AFTERNOON. CANNOT COMPLETELY RULE OUT A
VERY ISOLATED SHOWER/THUNDERSTORM THIS AFTERNOON IN THE VICINITY
OF KCNU...AS A WEAK UPPER IMPULSE APPROACHING FROM THE NORTH
INTERACTS WITH A WEAKLY UNSTABLE AIRMASS...BUT WILL LEAVE OUT OF
KCNU TAF DUE TO LOW PROBABILITIES AND SPARSE COVERAGE.
KLEINSASSER
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 69 96 69 96 / 0 0 0 10
HUTCHINSON 66 96 68 96 / 0 0 0 10
NEWTON 67 95 68 95 / 0 0 0 10
ELDORADO 66 95 67 95 / 10 0 0 10
WINFIELD-KWLD 67 96 69 96 / 10 0 0 10
RUSSELL 65 96 68 97 / 0 0 10 10
GREAT BEND 65 95 67 96 / 0 0 10 10
SALINA 67 96 69 96 / 0 0 0 10
MCPHERSON 66 96 68 96 / 0 0 0 10
COFFEYVILLE 68 96 69 96 / 10 10 0 10
CHANUTE 66 95 68 95 / 10 10 0 10
IOLA 66 95 68 95 / 10 10 0 10
PARSONS-KPPF 66 95 68 95 / 10 10 0 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
557 PM EDT THU JUL 12 2012
.UPDATE...
ISSUED AT 557 PM EDT THU JUL 12 2012
ACROSS EASTERN KENTUCKY...A SHIELD OF SOAKING RAINFALL CONTINUES TO EDGE
NORTH INTO THE FORECAST AREA WITH AN EMBEDDED RUMBLE OF THUNDER OR TWO.
THE CONVECTION NORTH OF THE EDGE OF THE RAINFALL HAS SINCE DIED OFF
AND SO WILL EXPECT FEW INSTANCES OF THUNDER THROUGH THE OVERNIGHT
PERIOD. HAVE ADJUSTED THE TEMPERATURE TRENDS AND DEWS ACCORDING TO
THE APPROACH OF THE RAINFALL. DECIDED NOT TO ISSUE A NEW ZFP AND SENT
GRIDS TO NDFD...HOWEVER...IF STRIKES ACROSS THE AREA CONTINUE TO BE
NIL INTO THE EVENING...MAY PULL THUNDER FOR THE NIGHT WITH THE NEXT
ZFP ISSUANCE.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 340 PM EDT THU JUL 12 2012
18Z SFC ANALYSIS SHOWS HIGH PRESSURE TO THE NORTHEAST OF THE AREA
WITH AN INVERTED TROUGH TAKING SHAPE THROUGH WESTERN TENNESSEE AND UP
INTO CENTRAL KENTUCKY. AT THE NOSE OF THIS...A LARGE PCPN SHIELD IS
STEADILY OVERTAKING MORE OF THE JKL CWA FROM SOUTHEAST TO NORTHWEST.
THE THICK CLOUDS AND EARLY PCPN REALLY KEPT TEMPERATURES FROM
CLIMBING TOO HIGH IN THE CUMBERLAND VALLEY AND AS SUCH THE STABILITY
HAS TAKEN THE FORM OF MAINLY SHOWERS THERE. FURTHER TO THE NORTH AND
WEST...THOUGH...MORE HEATING AND INSTABILITY HAS LED TO HEALTHIER
CONVECTIVE CELLS AND EVEN THE ODD THUNDERSTORM. EXPECT THAT TO BE THE
CASE THROUGH THE EVENING...THOUGH THE BULK OF THE PCPN WILL FALL AS
SHOWERS. SPECIFICALLY...TEMPERATURE READINGS AT 2 PM EDT VARIED FROM
THE LOWER 80S IN THE NORTHWEST WITH THE THINNER CLOUDS...TO LOWER 70S
IN THE FAR SOUTHEAST IN THE SHOWERS. WINDS HAVE BEEN LIGHT THROUGH
THE DAY AND GENERALLY FROM THE SOUTHEAST...WHICH HAS ALSO LIKELY
HELPED TO GENERATE LOW LEVEL DOWNSLOPING WORKING AGAINST THE PCPN
THROUGH THIS AFTERNOON. EVEN SO...WHERE THE CONVECTION HAS BEEN
STRONGER IT ALSO HAS MOVED SLOWLY AND IS LEAVING BEHIND DECENT
RAINFALL TOTALS OVER A SHORT AMOUNT OF TIME...GIVEN THE HIGH PW
ENVIRONMENT.
THE MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE UPPER LEVEL PATTERN
AND FEATURES TO AFFECT THE REGION THROUGH THE SHORT TERM. KENTUCKY
AND THE MID MISSISSIPPI VALLEY WILL BE IN BETWEEN TWO RIDGES TO THE
WEST AND EAST. THIS LOWER HEIGHT REGION IS POOLING WEAK PACKETS OF
SHORTWAVE ENERGY WHILE THE NEAREST TROUGH STAYS OFF TO THE NORTH
CLOSER TO GREAT LAKES AND NOT ABLE TO PUSH OUT THE LOST ENERGY...
THROUGH SATURDAY MORNING. THE WEAKNESS ALOFT COMBINED WITH SOME
ENERGY AND HIGH PWS OVER THE AREA WILL KEEP THE THREAT OF WIDESPREAD
AND OCCASIONALLY HEAVY RAINS IN THE FORECAST FOR THE BULK OF THE
PERIOD. WITH THE MODEL SIMILARITIES HAVE FOLLOWED A BLENDED APPROACH
FAVORING THE NAM12 FOR MESOSCALE DETAILS.
SENSIBLE WEATHER WILL FEATURE A MUCH NEEDED SOAKING RAIN EVENT
THROUGH FRIDAY AS THE UPPER LEVEL FACTORS COMBINE WITH THE HIGH PWS
AIR IN PLACE TO SUPPORT CONVECTION. SPECIFICALLY...EXPECT THE BEST
CHANCE FOR HEAVY RAINS TO OCCUR LATER TONIGHT AND INTO THE FIRST
PART OF FRIDAY PER THE EVOLUTION DEPICTED IN THE LATEST HRRR AND
NAM12. THIS WILL GIVE A FAIRLY UNIFORM PATTERN OF HIGHER RAIN
AMOUNTS...BUT THERE WILL STILL LIKELY BE CONSIDERABLE VARIABILITY
WITH LOCALIZED HIGHER AMOUNTS GIVEN THE CONVECTIVE NATURE. WILL
CONTINUE TO MENTION THE EXCESSIVE POTENTIAL IN THE HWO...BUT STILL
LEAVE IT OUT FROM THE GRIDS AND ZONES. THE PCPN WILL START TO WANE
LATER ON FRIDAY AS THE CORE OF IT SHIFTS NORTHWEST AND OUT OF THE
BULK OF THE CWA. THERE WILL STILL BE A GOOD THREAT OF SHOWERS AND
EVEN A THUNDERSTORM INTO SATURDAY MORNING BUT THE BEST RAINS WILL
HAVE MOVED ON BY THEN. THIS RAIN IS QUITE BENEFICIAL AND WILL
HOPEFULLY PUT A DECENT DENT IN OUR RAINFALL DEFICIT. AS FOR TEMPS...
KEPT THEM FAIRLY UNIFORM SPATIALLY AND ELEVATIONALLY...WITH THE
DIFFERENCES DRIVEN MORE BY THE RAIN PATTERN AND HIGH MOISTURE CONTENT
OF THE AIR RATHER THAN ANY TERRAIN DIFFERENCES.
FOLLOWED THE MET TEMPERATURES AND DEWPOINTS MOST CLOSELY FOR THE
SHORT TERM AS THEY LOOKED REASONABLE FOR THE PCPN PATTERN AND MATCHED
WELL WITH THE INHERITED GRIDS. AS FOR POPS...GENERALLY ENDED UP ON
THE HIGH SIDE OF GUIDANCE...WHICH WAS ALSO FAIRLY SIMILAR THROUGH THE
PERIOD.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 320 PM EDT THU JUL 12 2012
THE MODELS CONTINUE TO SHOW AN UNSETTLED PATTERN TO REMAIN ACROSS
THE OHIO AND TENNESSEE VALLEYS THROUGH THE EXTENDED AS AN UPPER
LEVEL RIDGE REMAINS NEARLY ANCHORED ACROSS BERMUDA...KEEPING A
PERSISTENT FEED OF MOISTURE ACROSS EASTERN KENTUCKY...WHILE AT THE
SAME TIME EXPOSING THE REGION TO PASSING WEAK DISTURBANCES IN THE
FLOW AROUND THE RIDGE. GIVEN THE CONTINUED LOW CONFIDENCE IN TIMING
ANYTHING THIS FAR OUT...WILL KEEP THE HIGHEST POPS CENTERED AROUND
THE DIURNALLY FAVORED PERIODS. TOWARDS THE END OF THE WORK WEEK...A
NORTHERN STREAM TROUGH WILL ATTEMPT TO BRING A COLD FRONT THROUGH
THE AREA. WILL STICK WITH A SLOWER TIMING WITH THIS FEATURE.
FOR TEMPERATURES...SLIGHTLY ABOVE NORMAL READINGS WILL REIGN...WITH
HIGHS IN THE MID TO UPPER 80S...AND LOWS AROUND 70.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 225 PM EDT THU JUL 12 2012
THE TIMING OF THE PCPN THREAT FROM THE EARLIER TAF HAS BEEN WORKING
OUT. EXPECT THEM ALL TO START REPORTING PCPN OVER THE NEXT COUPLE OF
HOURS WITH BRIEF DIPS DOWN TO MVFR IN NY HEAVIER SHOWERS. WILL GO
WITH VCTS AT THE TAF SITES THROUGH THE TAF PERIOD AND A TEMPO FOR IFR
DURING THE LATE NIGHT HOURS WHEN THE MODELS INDICATE THE HEAVY RAIN
POTENTIAL. AWAY FROM ANY STORMS...WINDS WILL BE LIGHT AND VARIABLE.
SCATTERED SHRA
WITH VSBY IN THE IFR/MVFR RANGE DUE TO HIGH MOISTURE CONTENT OF THE
AIR AS THE NOCTURNAL COOLING BEGINS TO TAKE EFFECT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...GREIF
LONG TERM....GEOGERIAN
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
340 PM EDT THU JUL 12 2012
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 340 PM EDT THU JUL 12 2012
18Z SFC ANALYSIS SHOWS HIGH PRESSURE TO THE NORTHEAST OF THE AREA
WITH AN INVERTED TROUGH TAKING SHAPE THROUGH WESTERN TENNESSEE AND UP
INTO CENTRAL KENTUCKY. AT THE NOSE OF THIS...A LARGE PCPN SHIELD IS
STEADILY OVERTAKING MORE OF THE JKL CWA FROM SOUTHEAST TO NORTHWEST.
THE THICK CLOUDS AND EARLY PCPN REALLY KEPT TEMPERATURES FROM
CLIMBING TOO HIGH IN THE CUMBERLAND VALLEY AND AS SUCH THE STABILITY
HAS TAKEN THE FORM OF MAINLY SHOWERS THERE. FURTHER TO THE NORTH AND
WEST...THOUGH...MORE HEATING AND INSTABILITY HAS LED TO HEALTHIER
CONVECTIVE CELLS AND EVEN THE ODD THUNDERSTORM. EXPECT THAT TO BE THE
CASE THROUGH THE EVENING...THOUGH THE BULK OF THE PCPN WILL FALL AS
SHOWERS. SPECIFICALLY...TEMPERATURE READINGS AT 2 PM EDT VARIED FROM
THE LOWER 80S IN THE NORTHWEST WITH THE THINNER CLOUDS...TO LOWER 70S
IN THE FAR SOUTHEAST IN THE SHOWERS. WINDS HAVE BEEN LIGHT THROUGH
THE DAY AND GENERALLY FROM THE SOUTHEAST...WHICH HAS ALSO LIKELY
HELPED TO GENERATE LOW LEVEL DOWNSLOPING WORKING AGAINST THE PCPN
THROUGH THIS AFTERNOON. EVEN SO...WHERE THE CONVECTION HAS BEEN
STRONGER IT ALSO HAS MOVED SLOWLY AND IS LEAVING BEHIND DECENT
RAINFALL TOTALS OVER A SHORT AMOUNT OF TIME...GIVEN THE HIGH PW
ENVIRONMENT.
THE MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE UPPER LEVEL PATTERN
AND FEATURES TO AFFECT THE REGION THROUGH THE SHORT TERM. KENTUCKY
AND THE MID MISSISSIPPI VALLEY WILL BE IN BETWEEN TWO RIDGES TO THE
WEST AND EAST. THIS LOWER HEIGHT REGION IS POOLING WEAK PACKETS OF
SHORTWAVE ENERGY WHILE THE NEAREST TROUGH STAYS OFF TO THE NORTH
CLOSER TO GREAT LAKES AND NOT ABLE TO PUSH OUT THE LOST ENERGY...
THROUGH SATURDAY MORNING. THE WEAKNESS ALOFT COMBINED WITH SOME
ENERGY AND HIGH PWS OVER THE AREA WILL KEEP THE THREAT OF WIDESPREAD
AND OCCASIONALLY HEAVY RAINS IN THE FORECAST FOR THE BULK OF THE
PERIOD. WITH THE MODEL SIMILARITIES HAVE FOLLOWED A BLENDED APPROACH
FAVORING THE NAM12 FOR MESOSCALE DETAILS.
SENSIBLE WEATHER WILL FEATURE A MUCH NEEDED SOAKING RAIN EVENT
THROUGH FRIDAY AS THE UPPER LEVEL FACTORS COMBINE WITH THE HIGH PWS
AIR IN PLACE TO SUPPORT CONVECTION. SPECIFICALLY...EXPECT THE BEST
CHANCE FOR HEAVY RAINS TO OCCUR LATER TONIGHT AND INTO THE FIRST
PART OF FRIDAY PER THE EVOLUTION DEPICTED IN THE LATEST HRRR AND
NAM12. THIS WILL GIVE A FAIRLY UNIFORM PATTERN OF HIGHER RAIN
AMOUNTS...BUT THERE WILL STILL LIKELY BE CONSIDERABLE VARIABILITY
WITH LOCALIZED HIGHER AMOUNTS GIVEN THE CONVECTIVE NATURE. WILL
CONTINUE TO MENTION THE EXCESSIVE POTENTIAL IN THE HWO...BUT STILL
LEAVE IT OUT FROM THE GRIDS AND ZONES. THE PCPN WILL START TO WANE
LATER ON FRIDAY AS THE CORE OF IT SHIFTS NORTHWEST AND OUT OF THE
BULK OF THE CWA. THERE WILL STILL BE A GOOD THREAT OF SHOWERS AND
EVEN A THUNDERSTORM INTO SATURDAY MORNING BUT THE BEST RAINS WILL
HAVE MOVED ON BY THEN. THIS RAIN IS QUITE BENEFICIAL AND WILL
HOPEFULLY PUT A DECENT DENT IN OUR RAINFALL DEFICIT. AS FOR TEMPS...
KEPT THEM FAIRLY UNIFORM SPATIALLY AND ELEVATIONALLY...WITH THE
DIFFERENCES DRIVEN MORE BY THE RAIN PATTERN AND HIGH MOISTURE CONTENT
OF THE AIR RATHER THAN ANY TERRAIN DIFFERENCES.
FOLLOWED THE MET TEMPERATURES AND DEWPOINTS MOST CLOSELY FOR THE
SHORT TERM AS THEY LOOKED REASONABLE FOR THE PCPN PATTERN AND MATCHED
WELL WITH THE INHERITED GRIDS. AS FOR POPS...GENERALLY ENDED UP ON
THE HIGH SIDE OF GUIDANCE...WHICH WAS ALSO FAIRLY SIMILAR THROUGH THE
PERIOD.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 320 PM EDT THU JUL 12 2012
THE MODELS CONTINUE TO SHOW AN UNSETTLED PATTERN TO REMAIN ACROSS
THE OHIO AND TENNESSEE VALLEYS THROUGH THE EXTENDED AS AN UPPER
LEVEL RIDGE REMAINS NEARLY ANCHORED ACROSS BERMUDA...KEEPING A
PERSISTENT FEED OF MOISTURE ACROSS EASTERN KENTUCKY...WHILE AT THE
SAME TIME EXPOSING THE REGION TO PASSING WEAK DISTURBANCES IN THE
FLOW AROUND THE RIDGE. GIVEN THE CONTINUED LOW CONFIDENCE IN TIMING
ANYTHING THIS FAR OUT...WILL KEEP THE HIGHEST POPS CENTERED AROUND
THE DIURNALLY FAVORED PERIODS. TOWARDS THE END OF THE WORK WEEK...A
NORTHERN STREAM TROUGH WILL ATTEMPT TO BRING A COLD FRONT THROUGH
THE AREA. WILL STICK WITH A SLOWER TIMING WITH THIS FEATURE.
FOR TEMPERATURES...SLIGHTLY ABOVE NORMAL READINGS WILL REIGN...WITH
HIGHS IN THE MID TO UPPER 80S...AND LOWS AROUND 70.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 225 PM EDT THU JUL 12 2012
THE TIMING OF THE PCPN THREAT FROM THE EARLIER TAF HAS BEEN WORKING
OUT. EXPECT THEM ALL TO START REPORTING PCPN OVER THE NEXT COUPLE OF
HOURS WITH BRIEF DIPS DOWN TO MVFR IN NY HEAVIER SHOWERS. WILL GO
WITH VCTS AT THE TAF SITES THROUGH THE TAF PERIOD AND A TEMPO FOR IFR
DURING THE LATE NIGHT HOURS WHEN THE MODELS INDICATE THE HEAVY RAIN
POTENTIAL. AWAY FROM ANY STORMS...WINDS WILL BE LIGHT AND VARIABLE.
SCATTERED SHRA
WITH VSBY IN THE IFR/MVFR RANGE DUE TO HIGH MOISTURE CONTENT OF THE
AIR AS THE NOCTURNAL COOLING BEGINS TO TAKE EFFECT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM....GEOGERIAN
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1248 AM EDT THU JUL 12 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD EAST THROUGH THURSDAY. A WEAK COLD FRONT
BRIEFLY CROSSES NORTHERN MAINE LATE THURSDAY. A WARM FRONT WILL
THEN BRING WARMER AND MORE HUMID CONDITIONS ON FRIDAY INTO THE
WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
1245 AM UPDATE...SATELLITE IS SHOWING A BANK OF FOG ROLLING IN OFF
THE OCEAN, WITH KBHB NOW 1/2SM AND OVERCAST AT 200 FT. HAVE
THEREFORE UPDATED TO ADD FOG ALONG THE COAST THROUGH ABOUT
DAYBREAK. THE HRRR HAS A PRETTY GOOD HANDLE ON THE FOG AND KEEPS
IT LIMITED TO RIGHT ALONG THE COAST, SO KEPT ANY MENTION OF FOG
OUT OF THE INLAND ZONES. NO OTHER CHANGES WERE NEEDED.
PREVIOUS DISCUSSION...HIGH PRESSURE WILL MOVE EAST AS A WEAK COLD
FRONT TO DIP SOUTH OUT OF CANADA INTO NORTHERN MAINE TOMORROW
EVENING AROUND THE END OF THE PERIOD. THE GFS...ECMWF...NAM...AND
UKMET KEEP THE FRONT ACROSS EXTREME NRN ME OR JUST TO THE NORTH.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
A WEAK SURFACE BOUNDARY IS EXPECTED TO SAG SOUTH ACROSS NORTHERN
MAINE LATE THURSDAY NIGHT INTO FRIDAY. MODELS ARE IN SOME
DISAGREEMENT AS TO JUST HOW FAST AND HOW FAR SOUTH IT WILL MAKE IT.
THE GENERAL CONSENSUS IS FOR IT TO REACH FROM SAINT PAMPHILE TO
HOULTON BY LATE FRIDAY AFTERNOON. FORECAST SOUNDINGS SHOW SOME
INSTABILITY PRESENT DURING THE AFTERNOON. THAT COMBINED WITH THE
BOUNDARY TO FOCUS DEVELOPMENT...WOULD EXPECT SCATTERED SHOWERS AND
POSSIBLY THUNDERSTORMS FOR THAT AREA WITH A BUFFER OF SLIGHT CHANCE
SHOWERS WHICH INCLUDES MAINLY THE NORTHEAST HALF OF THE FORECAST
AREA. WILL BACK OFF ON MENTION OF THUNDER FRIDAY NIGHT WITH THE LOSS
OF DAYTIME HEATING THEN BRING MENTION OF THUNDER BACK FOR NORTHEAST
MAINE ON SATURDAY. MAX TEMPS SHOULD REACH THE 80S FOR MOST LOCATIONS
FRIDAY AND SATURDAY WITH IN THE 50S AND LOWER 60S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
UPPER TROF OVER LABRADOR FINALLY BEGINS TO PULL INTO ATLANTIC
WITH WARM MOIST RETURN FLOW BEGINNING TO ESTABLISH FOR MOST OF
CWA BY SATURDAY. EXCEPTION CONTINUES TO BE MOST NORTHERN AREAS
WHERE A WEAK FRONTAL BOUNDARY CONTINUES TO HANG ON ALONG ST JOHN
RIVER VALLEY. RESULT IS THAT CLOUD COVER ALONE WILL BE SUFFICIENT
TO KEEP NORTHERN ZONES A BIT COOLER. ECMWF CONTINUES TO BE MUCH
SLOWER THAN GFS ON ADVECTION OF MOISTURE UP MISSISSIPPI AND OHIO
VALLEYS. FOR NOW WILL STAY WITH CONTINUITY AND GO WITH CHC AFTN
SHWR/TSTM POPS ACROSS ALL AREAS SUN. A WEAK COLD FRONT PUSHES
ACROSS AREA MONDAY AND TUESDAY WITH CHC SHWR/TSTM POPS THROUGH
TUESDAY EVENING BEFORE COOLER DRIER AIR ADVECTS IN FOR WEDNESDAY.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
NEAR TERM: MARINE FOG HAS MOVED SLIGHTLY INLAND INTO BAR HARBOR
EARLY THIS MORNING. VISIBILITY IS NOW 1/2SM AND CEILINGS BELOW 500
FT. THESE CONDITIONS WILL REMAIN THROUGH ABOUT DAYBREAK. THE FOG
AND IFR WILL REMAIN LIMITED TO RIGHT ALONG THE COAST. AT ALL OTHER
TERMINALS, VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. CLOUD
HEIGHTS WILL LOWER ACROSS NRN ME STARTING TOMORROW AFTERNOON.
EXPECT A MID CLOUD DECK ACROSS FVE. SCT TO BKN MID CLOUDS FOR CAR
AND PQI.
SHORT TERM: VFR CONDITIONS EXPECTED TO CONTINUE FOR MOST LOCATIONS THROUGH
MONDAY. THE ONLY EXCEPTION MAY BE KBHB WHERE LIGHT ONSHORE FLOW
AND CLEAR SKIES MAY AID IN THE DEVELOPMENT OF OVERNIGHT FOG.
&&
.MARINE...
NEAR TERM: HIGH PRESSURE WILL DOMINATE ACROSS THE COASTAL WATERS
THROUGH THE NEAR TERM PERIOD. WINDS AND SEAS WILL REMAIN BELOW SCA
CRITERIA THROUGH THE PERIOD.
SHORT TERM: CONDITIONS EXPECTED TO REMAIN BELOW SMALL CRAFT
LEVELS THROUGH THE WEEKEND.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HASTINGS/NORTON
SHORT TERM...RUNYAN
LONG TERM...PJR
AVIATION...HASTINGS/NORTON
MARINE...HASTINGS/NORTON/RUNYAN
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
512 PM EDT THU JUL 12 2012
.SYNOPSIS...
SOUTHERLY WINDS, IN THE WAKE OF HIGH PRESSURE HEADING TO THE EAST
COAST, WILL BRING HIGHER HUMIDITY TO THE UPPER OHIO VALLEY, WHICH
WILL PROMOTE A CHANCE OF THUNDERSTORMS INTO EARLY EVENING, AND
THEN A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
UPDATING TO COVER AREA OF CONVECTION, WHICH APPEARS TO BE
DEVELOPING ALONG AN OLD BOUNDARY. EXPECT ACTIVITY TO WANE WITH
SUNSET.
PREVIOUS FORECAST...
PER RECENT SURFACE AND SATELLITE DATA, HAVE MADE SMALL ADJUSTMENTS
TO CLOUD COVER ACROSS THE UPPER OHIO VALLEY. HAVE CONTINUED A
SLIGHT CHANCE OF THUNDERSTORMS THROUGH EARLY EVENING, AS RECENT
SATELLITE DATA SHOWS CUMULUS BUILDUPS AND HRRR MODEL OUTPUT SHOWS
ISOLATED THUNDERSTORM DEVELOPMENT, MAINLY NEAR THE ERIE LAKE
BREEZE FRONT AND THE APPALACHIAN MOUNTAINS.
EXPECT EARLY MORNING LOWS TO BE 2 TO 5 DEGREES WARMER THAN NORMAL
PER BLEND OF RECENT GFS AND NAM MOS.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
BLEND OF RECENT SREF MODEL OUTPUT, COUPLED WITH DETAILS FROM
RECENT NAM MODEL OUTPUT, SHOW THUNDERSTORM CHANCES ACROSS THE
UPPER OHIO VALLEY INCREASING THIS PERIOD.
THIS IS DUE TO A COUPLE FACTORS. THE FIRST FACTOR IS INCREASING
SURFACE LAYER HUMIDITY THAT WILL PROMOTE INCREASED VERTICAL
INSTABILITY. THE SECOND FACTOR IS A TREND TOWARD BETTER ORGANIZED
LIFTING MECHANISMS. AT SOME POINT THERE WILL BE INCREASED
MOISTURE CONVERGENCE ALONG THE LEADING EDGE OF THE HIGHER SURFACE
DEW POINTS, A MESOSCALE FEATURE THAT COULD BE TERMED A DEW POINT
WARM FRONT. THE SLOW EASTWARD PROGRESSION OF AN UPPER LEVEL SHORT-
WAVE TROUGH NEAR THE GREAT LAKES, CAN PROVIDE ANOTHER SOURCE OF
LIFT AND INSTABILITY WITH ITS PRECEDING DIFFLUENT FLOW AND
SLIGHTLY COLDER TEMPERATURES ALOFT.
DESPITE THE INCREASED THUNDERSTORM POTENTIAL, CONCUR WITH SPC
REGARDING RESTRICTED SEVERE POTENTIAL DUE TO LACK OF VERTICAL
WIND SHEAR. THERE CAN BE MORE OF A POTENTIAL FOR HEAVIER
THUNDERSTORM RAINS DUE TO LARGER THAN NORMAL PRECIPITABLE WATER
VALUES AND POTENTIAL FOR SLOW THUNDERSTORM MOVEMENT OR TRAINING.
SOIL CONDITIONS ARE SUCH THAT MORE THAN 2 INCHES OF RAIN WOULD BE
NEEDED IN 2 HOURS OR LESS TO CAUSE FLOODING ISSUES.
FORECASTED WARMER THAN NORMAL TEMPERATURES THIS PERIOD, BUT WITH A
SLIGHTLY SMALL DIURNAL TEMPERATURE RANGE DUE TO AN INCREASED CLOUD
COVER, MORE HUMID SURFACE LAYER, AND THUNDERSTORM POTENTIAL. THIS
IS SUPPORTED BY RECENT GFS AND NAM MOS, WHICH SHOWED MOST PERIODS
WITH TEMPERATURES 2 TO 5 DEGREES WARMER THAN NORMAL.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
MAINTAINED A CHANCE OF SHOWERS AND THUNDERSTORMS THIS PERIOD WITH
CONTINUED HIGHER HUMIDITY AND WARMER THAN NORMAL TEMPERATURES.
BLEND OF RECENT NAEFS AND ECMWF MODEL OUTPUT CONTINUE TO SHOW
WEAK SOUTH TO SOUTHWESTERLY WINDS AT LOW LEVELS ACROSS THE UPPER
OHIO VALLEY.
AT UPPER LEVELS, THE INITIAL WEAK SHORT-WAVE TROUGH NEAR THE GREAT
LAKES MAY BE SHEARED AS SHORT-WAVE TROUGH MOVES TOWARD THE GREAT
LAKES FROM CENTRAL CANADA. THIS SCENARIO COULD RESULT IN A
SOUTHEASTWARD MOVING COLD FRONT THROUGH THE GREAT LAKES AND
PERHAPS UPPER OHIO VALLEY, BUT LIKELY NOT BEFORE THURSDAY.
SO EXPECT CONTINUED HUMID CONDITIONS ACROSS THE UPPER OHIO VALLEY
THIS PERIOD, WHICH WILL PROMOTE A CONTINUING CHANCE OF SHOWERS AND
THUNDERSTORMS.
FORECASTED TEMPERATURES UP TO 7 DEGREES WARMER THAN NORMAL BASED
ON HPC GUIDANCE WHICH IN GENERAL WAS A COUPLE DEGREES WARMER THAN
GFS AND ECMWF MOS BUT CLOSE TO NAEFS MEDIAN VALUES.
&&
.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
EAST COAST HIGH PRESSURE WILL PROVIDE GENERAL VFR CONDITIONS INTO
FRIDAY NIGHT, ALTHOUGH ISOLATED THUNDERSTORMS CAN POTENTIALLY
PROVIDE BRIEF RESTRICTIONS. PATCHY MVFR FOG AND HAZE IS ALSO POSSIBLE
EARLY FRIDAY MORNING, BUT ONLY INCLUDED SUCH RESTRICTIONS AT THE
TYPICALLY-PREFERRED TAF SITES SUCH AS KFKL AND KZZV.
OUTLOOK...FRIDAY NIGHT THROUGH TUESDAY...
CONTINUED HUMID CONDITIONS WILL PROMOTE POSSIBLE RESTRICTIONS DUE
TO PATCHY FOG AND HAZE EACH MORNING, AND SCATTERED THUNDERSTORMS
AT ANY TIME.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1145 AM EDT THU JUL 12 2012
.SYNOPSIS...
SOUTHERLY WINDS, IN THE WAKE OF HIGH PRESSURE HEADING TO THE EAST
COAST, WILL BRING INCREASING HUMIDITY TO THE UPPER OHIO VALLEY,
WHICH WILL PROMOTE A SLIGHT CHANCE OF THUNDERSTORMS THIS AFTERNOON,
THEN A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS THIS WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
PER RECENT SURFACE AND SATELLITE DATA, HAVE MADE SMALL ADJUSTMENTS
TO CLOUD COVER ACROSS THE UPPER OHIO VALLEY. EXPECT DEVELOPING
CUMULUS CLOUDS TO PARTLY DECREASE THE AMOUNT OF SUNSHINE THIS
AFTERNOON.
EXPECT A SLIGHT CHANCE OF THUNDERSTORMS THIS AFTERNOON, AS NAM
MODEL PROFILES SHOW INCREASED SURFACE LAYER HUMIDITY HAS LOWERED
CONVECTIVE TEMPERATURES INTO THE LOWER 80S. RECENT HRRR MODEL
OUTPUT SHOWS A DEVELOPING ERIE LAKE BREEZE FRONT CAN BECOME
FOCUS OF ISOLATED THUNDERSTORMS NEAR THE I-80 CORRIDOR BEFORE MID
AFTERNOON. OROGRAPHICALLY-INFLUENCED DIFFERENTIAL SURFACE HEATING
ACROSS THE APPALACHIAN MOUNTAINS CAN LIKEWISE FOCUS AFTERNOON
THUNDERSTORM DEVELOPMENT.
FORECASTED AFTERNOON HIGH TEMPERATURES CLOSER TO WARMER NAM MOS,
WHICH MEANS SOME LOWER ELEVATION LOCATIONS SOUTH MAY REACH 90
DEGREES. LOWS TONIGHT WILL BE 2 TO 5 DEGREES WARMER THAN NORMAL
PER BLEND OF RECENT GFS AND NAM MOS.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
BLEND OF RECENT SREF MODEL OUTPUT, COUPLED WITH DETAILS FROM
THE MOST RECENT NAM MODEL OUTPUT, SHOW THUNDERSTORM CHANCES
ACROSS THE UPPER OHIO VALLEY INCREASING THIS PERIOD.
THIS IS DUE TO TWO FACTORS. THE FIRST FACTOR IS INCREASING
SURFACE LAYER HUMIDITY THAT WILL PROMOTE INCREASED VERTICAL
INSTABILITY. THE SECOND FACTOR IS BETTER ORGANIZED LIFTING
MECHANISMS. PART OF THIS IS DUE TO MOISTURE CONVERGENCE ALONG THE
LEADING EDGE OF THE HIGHER SURFACE DEW POINTS, WHICH COULD BE
TERMED A DEW POINT WARM FRONT. THE OTHER PART IS THE APPROACH OF A
SLOW EASTBOUND UPPER LEVEL SHORT-WAVE TROUGH SATURDAY.
FORECASTED A SLIGHTLY SMALL DIURNAL TEMPERATURE RANGE THIS PERIOD
DUE TO THE INCREASED CLOUD COVER AND THUNDERSTORM POTENTIAL, WHICH
IS SUPPORTED BY RECENT GFS AND NAM MOS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
BLEND OF RECENT NAEFS AND ECMWF MODEL OUTPUT SHOW AN INITIAL WEAK
UPPER LEVEL TROUGH ACROSS THE GREAT LAKES, DISSIPATING TOWARD
MID-WEEK. HOWEVER, WEAK SOUTH TO SOUTHWESTERLY WINDS WILL CONTINUE
AT LOW LEVELS AND THUS PROVIDE AN CONTINUED INFLUX OF GULF MOISTURE
INTO THE UPPER OHIO VALLEY.
THERE CAN STILL BE A DIFFUSE WARM FRONT ACROSS THE UPPER OHIO VALLEY
EARLY NEXT WEEK, BUT MESOSCALE THUNDERSTORM EVOLUTIONS MAY BETTER
DICTATE THE POSITION OF SUCH A BOUNDARY WITH REGARD TO ITS POTENTIAL
AS A LIFTING MECHANISM.
HENCE, CONCUR WITH HPC GUIDANCE, BASED ON GFS, ECMWF, AND NAEFS
MODEL OUTPUT, OF MAINTAINING WARMER AND MORE HUMID THAN NORMAL
CONDITIONS ACROSS THE UPPER OHIO VALLEY THIS PERIOD, ALONG WITH A
CHANCE OF INSTABILITY-INDUCED THUNDERSTORMS.
&&
.AVIATION /16Z THURSDAY THROUGH MONDAY/...
HIGH PRESSURE WILL PROVIDE GENERAL VFR CONDITIONS INTO TONIGHT,
WITH ISOLATED AFTERNOON THUNDERSTORMS POTENTIALLY PROVIDING BRIEF
RESTRICTIONS. PATCHY MVFR FOG AND HAZE IS POSSIBLE EARLY FRIDAY MORNING.
OUTLOOK...FRIDAY THROUGH MONDAY...
HUMID CONDITIONS WILL PROMOTE POSSIBLE RESTRICTIONS DUE TO EARLY
MORNING PATCHY FOG AND HAZE EACH DAY. A SLOW NORTHWARD MOVING
WARM FRONT WILL PROVIDE A CHANCE OF THUNDERSTORMS AND RESTRICTIONS INTO
EARLY NEXT WEEK.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
426 AM EDT THU JUL 12 2012
.SYNOPSIS...
HIGH PRESSURE CENTERED EAST OF THE AREA WILL ALLOW FOR ANOTHER DAY
OF MOSTLY DRY WEATHER WITH A FEW ISOLATED SHOWERS AND
THUNDERSTORMS ACROSS THE OHIO VALLEY THIS AFTERNOON. THE PATTERN
WILL THEN BECOME MORE UNSETTLED WITH INCREASING HUMIDITY BRINGING A
BETTER CHANCE FOR SHOWERS AND STORMS EACH DAY THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES DRY AIR IN PLACE WITH
A WEAK CYCLONIC FLOW CENTERED ACROSS OHIO. AT THE SURFACE, A
1023MB HIGH IS CENTERED ALONG THE JERSEY COAST WITH HIGH PRESSURE
EXTENDING WESTWARD INTO THE UPPER OHIO VALLEY. ASIDE FROM
A FEW PATCHES OF MID-DECK CLOUDS, SKIES ARE CLEAR ACROSS THE AREA.
TODAY AND TONIGHT...A 500MB TROUGH AXIS CENTERED ACROSS THE
ARKLATEX REGION WILL NUDGE NORTHEASTWARD, ADVECTING LOW-LEVEL
MOISTURE ACROSS THE TENNESSEE VALLEY AND INTO OHIO BY EVENING.
FORCING WILL BE LACKING MOSTLY THROUGH MUCH OF THE AFTERNOON AND
THE HRRR/WRF-NMM INDICATE THAT CONVECTION WILL BE DIURNALLY
DRIVEN AND ISOLATED. CONVECTION WILL MOSTLY DIMINISH BY SUNSET
WITH SCHC POPS FOR THE PITTSBURGH METRO AND POINTS SOUTHWARD
TONIGHT.
FOR TEMPS, FORECAST IS AROUND 5 DEGREES ABOVE LAMP GUIDANCE FOR
HIGHS, CLOSEST TO THE WARMER MET. HIGHS WILL RANGE FROM THE MID TO
UPPER 80S ACROSS THE LOWLANDS TO THE UPPER 70S ACROSS THE EASTERN
RIDGES. AS LOW-LEVEL MOISTURE AND WARMER TDS ADVECTING IN FROM THE
SOUTHWEST THIS LIMIT LOW TEMPS SOMEWHAT. LOWS TONIGHT ARE CLOSE TO
A MAV/MET BLEND, IN THE MID 60S ACROSS MOST LOCATIONS.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
THE GFS/ECMWF ARE IN AGREEMENT THAT A LONG WAVE TROUGH ACROSS THE
MISSISSIPPI VALLEY WILL DE-AMPLIFY AND SWING A PIECE OF ITS ENERGY
INTO THE OHIO VALLEY ON FRIDAY AS MORE OF A SHORT WAVE. SCHC POPS
START THE DAY AND RAMP UP TO 40-50 POPS ACROSS MUCH OF THE AREA AS
VORT MAX PUSHES FROM OHIO NORTHEASTWARD INTO WESTERN PA. PRECIP
FROM THE WAVE WILL ONLY SLIGHTLY ALLEVIATE INCREASING DROUGHT
CONDITIONS IN MOST AREAS. A QUARTER TO A HALF OF AN INCH RAINFALL
IS FORECAST WITH THIS SYSTEM THROUGH FRIDAY NIGHT. WEAK
INSTABILITY AND SHEAR CURRENTLY APPEAR TO BE INHIBITORS FOR SEVERE
WEATHER AT THIS TIME. HOWEVER, LOCALLY HEAVY DOWNPOURS WILL BE
POSSIBLE FOR AREAS SOUTH OF THE PITTSBURGH METRO WITH A WEAK WIND
FIELD IN PLACE AND THE GFS INDICATING PRECIPITABLE WATER VALUES
INCREASING TO 1.75 TO 2 INCHES SOUTH OF PITTSBURGH BY FRIDAY
EVENING.
A MID-LEVEL TROUGH WILL SLIDE FROM THE UPPER MIDWEST INTO THE
WESTERN GREAT LAKES, LEAVING THE UPPER OHIO VALLEY IN A
SOUTHWESTERLY FLOW WITH A DEEP LAYER OF MOISTURE IN PLACE. WITH
MODERATE INSTABILITY AND ABUNDANT MOISTURE, 40-50 POPS ARE AGAIN
FORECAST ACROSS THE AREA ON SATURDAY. THE POTENTIAL FOR LOCALLY
HEAVY DOWNPOURS WILL CONTINUE ON SATURDAY WITH PWATS AROUND 2
INCHES.
FOR TEMPS, FRIDAY FORECAST IS LOW CONFIDENCE AS GFS SEEMS TO BE
OVERDOING COOLER TEMPS IN RAIN-COOLED AIR WITH THE PASSING SHORT
WAVE. FORECAST IS CLOSEST TO THE ECMWF WITH HIGHS RANGING FROM THE
LOW 80S ACROSS NORTH-CENTRAL WV TO THE MID 80S FOR THE PITTSBURGH
METRO AND AREAS TO THE NORTH. SATURDAY WILL BE NOTICEABLY MORE
HUMID AS TDS INCREASE TO NEAR 70 WITH HIGHS AROUND 5 DEGREES ABOVE
NORMAL.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
BLEND OF RECENT NAEFS AND ECMWF MODEL OUTPUT SHOW AN INITIAL WEAK
UPPER LEVEL TROUGH ACROSS THE GREAT LAKES, DISSIPATING TOWARD
MID-WEEK. HOWEVER, WEAK SOUTH TO SOUTHWESTERLY WINDS WILL CONTINUE
AT LOW LEVELS AND THUS PROVIDE AN CONTINUED INFLUX OF GULF MOISTURE
INTO THE UPPER OHIO VALLEY.
THERE CAN STILL BE A DIFFUSE WARM FRONT ACROSS THE UPPER OHIO VALLEY
EARLY NEXT WEEK, BUT MESOSCALE THUNDERSTORM EVOLUTIONS MAY BETTER
DICTATE THE POSITION OF SUCH A BOUNDARY WITH REGARD TO ITS POTENTIAL
AS A LIFTING MECHANISM.
HENCE, CONCUR WITH HPC GUIDANCE, BASED ON GFS, ECMWF, AND NAEFS
MODEL OUTPUT, OF MAINTAINING WARMER AND MORE HUMID THAN NORMAL
CONDITIONS ACROSS THE UPPER OHIO VALLEY THIS PERIOD, ALONG WITH A
CHANCE OF INSTABILITY-INDUCED THUNDERSTORMS.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
HIGH PRESSURE WILL PROVIDE GENERAL VFR CONDITIONS FOR TODAY AND
TONIGHT. SOME PATCHY MVFR FOG IS POSSIBLE AROUND DAYBREAK.
OUTLOOK...FRIDAY THROUGH MONDAY...
PATCHY FOG POSSIBLE DURING EARLY MORNING EACH DAY. A SLOW MOVING
WARM FRONT FRIDAY AFTERNOON WILL MOVE NORTH CAUSING SCATTERED
THUNDERSTORMS. THE CHANCE OF THUNDERSTORMS REMAINS EACH DAY
BEGINNING FRIDAY AS LOW LEVEL MOISTURE CONTINUES TO MOVE
NORTHWARD.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
202 AM EDT THU JUL 12 2012
.SYNOPSIS...
HIGH PRESSURE CENTERED EAST OF THE AREA WILL ALLOW FOR ANOTHER DAY
OF MOSTLY DRY WEATHER WITH A FEW ISOLATED SHOWERS AND
THUNDERSTORMS ACROSS THE OHIO VALLEY THIS AFTERNOON. THE PATTERN
WILL THEN BECOME MORE UNSETTLED AS A PAIR OF UPPER LEVEL
DISTURBANCES MOVE INTO THE GREAT LAKES AND BRING A BETTER CHANCE
FOR SHOWERS AND STORMS EACH DAY THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE 06Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO
REMOVE THE MENTION OF SHOWERS AND THUNDERSTORMS OVERNIGHT.
OTHERWISE, LITTLE CHANGE TO THE GOING FORECAST.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES DRY AIR IN PLACE WITH A
WEAK CYCLONIC FLOW CENTERED ACROSS OHIO. AT THE SURFACE, A 1023MB
HIGH IS CENTERED ALONG THE JERSEY COAST WITH HIGH PRESSURE
EXTENDING WESTWARD INTO THE UPPER OHIO VALLEY. ASIDE FROM LINGERING
PATCHES OF MID-DECK CLOUDS RESULTANT FROM EARLIER CONVECTION,
SKIES ARE CLEAR ACROSS THE AREA.
TODAY AND TONIGHT...A 500MB TROUGH AXIS CENTERED ACROSS THE
ARKLATEX REGION WILL NUDGE NORTHEASTWARD, ADVECTING LOW-LEVEL
MOISTURE ACROSS THE TENNESSEE VALLEY AND INTO OHIO BY EVENING. A
FORCING MECHANISM WILL BE LACKING MOSTLY THROUGH MUCH OF THE AFTERNOON
AND CONVECTION IS ANTICIPATED TO BE DIURNALLY DRIVEN AND ISOLATED.
TOWARDS THE EVENING, A DEW POINT BOUNDARY WILL EDGE APPROACH FROM
THE WEST AND MAY PROVIDE SUFFICIENT FORCING TO BE THE FOCUS OF
CONVECTION LATE IN THE DAY. CONVECTION IS ANTICIPATED TO MOSTLY
DIMINISH BY SUNSET WITH A DRY FORECAST TONIGHT.
FOR TEMPS, FORECAST IS AROUND 5 DEGREES ABOVE LAMP GUIDANCE FOR
HIGHS, CLOSEST TO THE WARMER MET. HIGHS WILL RANGE FROM THE MID TO
UPPER 80S ACROSS THE LOWLANDS TO THE UPPER 70S ACROSS THE EASTERN
RIDGES. AS LOW-LEVEL MOISTURE AND WARMER TDS ADVECTING IN FROM THE
SOUTHWEST THIS LIMIT LOW TEMPS SOMEWHAT. LOWS TONIGHT ARE CLOSE TO
A MAV/MET BLEND, IN THE MID 60S ACROSS MOST LOCATIONS.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
500MB HIGH OVER THE ATLANTIC OCEAN WILL EXTEND A RIDGE TO THE WEST
ACROSS THE EAST COAST FOR FRIDAY AND SATURDAY. IT APPEARS THAT THIS
WILL PUSH MOISTURE AND BEST DYNAMICS A LITTLE FARTHER WEST THAN
PREVIOUSLY EXPECTED...GENERALLY ACROSS OHIO. AS A RESULT...WILL KEEP
CHANCE POPS FOR MUCH OF THIS FORECAST PERIOD...WITH THE HIGHEST POPS
GENERALLY WEST OF A LINE FROM DUBOIS TO PITTSBURGH TO ZANESVILLE.
ALTHOUGH SKIES WILL BE MOSTLY CLOUDY...SOUTHERLY WINDS WILL ALLOW
TEMPERATURES TO REMAIN NEAR NORMAL.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
BLEND OF RECENT NAEFS AND ECMWF MODEL OUTPUT SHOW AN INITIAL WEAK
UPPER LEVEL TROUGH ACROSS THE GREAT LAKES, DISSIPATING TOWARD
MID-WEEK. HOWEVER, WEAK SOUTH TO SOUTHWESTERLY WINDS WILL CONTINUE
AT LOW LEVELS AND THUS PROVIDE AN CONTINUED INFLUX OF GULF MOISTURE
INTO THE UPPER OHIO VALLEY.
THERE CAN STILL BE A DIFFUSE WARM FRONT ACROSS THE UPPER OHIO VALLEY
EARLY NEXT WEEK, BUT MESOSCALE THUNDERSTORM EVOLUTIONS MAY BETTER
DICTATE THE POSITION OF SUCH A BOUNDARY WITH REGARD TO ITS POTENTIAL
AS A LIFTING MECHANISM.
HENCE, CONCUR WITH HPC GUIDANCE, BASED ON GFS, ECMWF, AND NAEFS
MODEL OUTPUT, OF MAINTAINING WARMER AND MORE HUMID THAN NORMAL
CONDITIONS ACROSS THE UPPER OHIO VALLEY THIS PERIOD, ALONG WITH A
CHANCE OF INSTABILITY-INDUCED THUNDERSTORMS.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
HIGH PRESSURE WILL PROVIDE GENERAL VFR CONDITIONS FOR TODAY AND
TONIGHT. SOME PATCHY MVFR FOG IS POSSIBLE AROUND DAYBREAK.
OUTLOOK...FRIDAY THROUGH MONDAY...
PATCHY FOG POSSIBLE DURING EARLY MORNING EACH DAY. A SLOW MOVING
WARM FRONT FRIDAY AFTERNOON WILL MOVE NORTH CAUSING SCATTERED
THUNDERSTORMS. THE CHANCE OF THUNDERSTORMS REMAINS EACH DAY
BEGINNING FRIDAY AS LOW LEVEL MOISTURE CONTINUES TO MOVE
NORTHWARD.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1257 PM EDT THU JUL 12 2012
.SYNOPSIS...
ISSUED AT 335 AM EDT THU JUL 12 2012
HIGH PRESSURE WILL REMAIN OVER THE GREAT LAKES REGION THROUGH THE
REMAINDER OF THE WEEK...BRINGING WITH IT MODERATING TEMPERATURES AND
DRY WEATHER. TEMPERATURES WILL SLOWLY CLIMB INTO THE MID AND UPPER
80S THROUGH THE WEEK...AND INTO THE UPCOMING WEEKEND.
&&
.UPDATE...
ISSUED AT 1257 PM EDT THU JUL 12 2012
VERY QUIET BUT BEAUTIFUL WEATHER ONGOING OUT THE WINDOW...WITH
EARLIER THOUGHTS CONFIRMED AS DEW POINTS ARE IN THE PROCESS OF
TANKING. IN SPITE OF THIS...A RATHER HEALTHY CU FIELD HAS FIRED UP
OVER THE SOUTHERN COUNTIES IN SLIGHTLY BETTER LOW LEVEL MOISTURE
AXIS...BUT SHOULD RATHER QUICKLY BE ON THE DECLINE AS MIXING
CONTINUES TO DEEPEN. GOING HIGHS WELL INTO THE 80S (PERHAPS A SPOT
OR TWO NEAR 90) WILL WORK JUST FINE.
UPDATE ISSUED AT 1004 AM EDT THU JUL 12 2012
ONLY MINOR CHANGES NEEDED TO GOING FORECAST...WITH THE MAIN ONE
BEING TO FURTHER LOWER AFTERNOON DEW POINTS. SETUP ACROSS THE
REGION HAS CHANGED LITTLE FROM THIS TIME YESTERDAY...FEATURING
OVERALL FAIRLY FLAT FLOW ALOFT OVER THE GREAT LAKES...WHILE
EXPANSIVE AND ELONGATED LOW LEVEL RIDGING RESIDES FROM THE
NORTHEAST/MID ATLANTIC STATES RIGHT ON BACK INTO OUR NECK OF THE
WOODS. AIRMASS REMAINS QUITE DRY FOR THIS TIME OF THE
YEAR...LIKELY A FEEDBACK MECHANISM FROM THE ONGOING VERY DRY
CONDITIONS JUST TO OUR SOUTHWEST. PWATS HAVE INCHED UP OVER THE
PAST 24 HOURS...UP TO A WHOPPING 0.57 INCHES PER 12Z APX
RAOB...BUT MOST OF THAT MOISTURE IS UP TOP...WHILE THE LOW LEVELS
HAVE ACTUALLY FURTHER DRIED OUT FROM THIS TIME YESTERDAY.
DESPITE WHAT SHOULD BE LIMITED MIXING TODAY GIVEN VERY LIGHT WIND
FIELDS...MIXING UP TO 800MB STILL PUTS MUCH OF NORTHERN LOWER
FIRMLY IN AN AXIS OF VERY DRY AIR ALOFT. HINTS ON MET GUIDANCE AND
LATEST HRRR NUMBERS BOOST CONFIDENCE THAT READINGS MAY DIP INTO
THE 30S IN A NUMBER OF SPOTS THIS AFTERNOON (AWAY FROM THE LAKE
BREEZE INFLUENCE NEAR THE COASTS...OF COURSE). COMBINED WITH HIGHS
A COUPLE OF DEGREES WARMER THAN YESTERDAY GIVEN WEAK ONGOING WARM
ADVECTION...SHOULD SEE MIN RH VALUES DOWN INTO THE TEENS IN
SPOTS...WITH GOING ELEVATED FIRE DANGER MENTION DEFINITELY
WARRANTED.
OTHERWISE...NO MAJOR CHANGES MADE TO THE FORECAST...SAVE FOR
RAISING HIGHS A FEW DEGREES CLOSER TO THE WATER BEFORE LAKE
BREEZES KICK IN AFTER 17Z. COULD ALSO SEE A RENEWED CU FIELD
CLOSER TO LAKE SUPERIOR INTO EARLY AFTERNOON WITHIN AN AXIS OF
DEEPER MOISTURE LAID OUT OVER THE U.P...WITH EVEN AN OUTSIDE
CHANCE AT A ROGUE BRIEF SHOWER...THOUGH PROBABLY NOT GIVEN SLOWLY
GROWING CAP UP AROUND 600MB. OUTSIDE OF THAT...SIMPLY A BEAUTIFUL
SUMMERTIME DAY ACROSS NORTHERN MICHIGAN. ENJOY!
UPDATE ISSUED AT 636 AM EDT THU JUL 12 2012
NO CHANGES TO THE GOING FORECAST. BATCH OF MID CLOUD PRESENT
ACROSS EASTERN UPPER MICHIGAN AND THE STRAITS...WITH SOME HIGH
CLOUDS (CONVECTIVE DEBRIS) ALSO NOSING INTO THE NRN PART OF THE
STATE. HAVE PARTLY-MOSTLY SUNNY SKIES UP THAT WAY ALREADY.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 335 AM EDT THU JUL 12 2012
LOW AMPLITUDE 4-WAVE LONG WAVE HEMISPHERIC PATTERN CURRENTLY IN
PLACE WITH SUBTLE TROUGHING ACROSS EASTERN NOAM. LITTLE CHANGE IN
THIS PATTERN OVER THE NEXT FEW DAY WITH THE MAIN FLOW BOTTLED UP
ACROSS CANADA. AT THE SFC...BROAD HIGH PRESSURE REMAINS NEARLY
FIXED FROM MICHIGAN TO THE ATLANTIC COAST WITH STRONGER WARM/MOIST
ADVECTION FLOW PRESENT ACROSS SUPERIOR INTO ONTARIO PRODUCING A
FEW ROUNDS OF CONVECTION UP THAT WAY. ONE SMALL MCS IS CAUGHT UP
IN RELATIVE WEAK FLOW JUST NORTH OF LAKE SUPERIOR...DRIFTING
VERY SLOWLY SOUTHWARD TOWARD LAKE SUPERIOR AND PRODUCING A NICE
DUMPING OF RAIN FOR THAT AREA.
TODAY AND TONIGHT...HIGH PRESSURE WILL CONTINUE TO DOMINATE TODAY AND
TONIGHT WITH FAIR CONDITIONS PERSISTING. CONVECTION JUST NORTH OF
SUPERIOR NOT MAKING ANY SOUTHWARD PROGRESS...DYING AS IT GETS INTO
THE MORE STABLE ENVIRONMENT SOUTH OF ONTARIO. SO...THIS FEATURE
POSES LITTLE IF ANY PRECIP THREAT TO THIS CWA...BUT OF COURSE WILL
WATCH IT. SOME ASSOCIATED CLOUD COVER MAY DRIFT INTO THE NRN PARTS
OF THE CWA HOWEVER...ALONG WITH A BATCH OF MID CLOUD THAT HAS
DEVELOPED OVER EASTERN UPPER MICHIGAN AND THE STRAITS. OTHERWISE...
GIVEN THE VERY DRY AIRMASS OVER THE REGION...DAYTIME CU POTENTIAL
LOOKING PRETTY LOW TODAY...UNLESS SFC DEWPOINTS STAY UP A LITTLE
HIGHER THAN EXPECTED.
TEMPERATURES...FORECAST SOUNDINGS SUGGEST SLIGHTLY WARMER DAYTIME
HIGHS AS COMPARED TO WEDNESDAY...SOLID MID 80S...A LITTLE COOLER
NEAR THE LAKE SHORES WITH LIGHT WINDS/LAKE BREEZES SETTING UP BY
AFTERNOON. LIGHT WINDS/LOW DEWPOINTS AND MAINLY CLEAR SKIES WILL
ALLOW TEMPS TO DROP BACK INTO THE 50S TONIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 335 AM EDT THU JUL 12 2012
FRIDAY...THE GFS HAS MORE SFC MOISTURE THAN THE ECMWF AND ALSO HAS A
MORE DEVELOPED 500 MB WAVE MOVING INTO W LAKE SUPERIOR. THE GFS ALSO
HAS MUCH MORE MOISTURE WITH THE SYSTEM IN THE SE STATES WHICH SPILLS
UP NORTH TO US. THINK THAT THIS IS TOO MOIST STILL AS THE SFC
MOISTURE BIAS, SHOWN IN THE SFC DEWPOINTS, IS TRYING TO DEVELOPING
THINGS TOO MUCH. INTERESTINGLY, THE MOISTURE AT IN THE 700-500 MB
LAYER, LOOKS THE SAME. SO IF THE SFC MOISTURE WASN`T SO HIGH ON GFS
WOULD THINK IT WOULD LOOK LIKE THE ECMWF. NAM TRIES TO DEVELOP
SOMETHING LATE(AFTER 21Z) IN S LOWER AND MOVES IT UP INTO NW LOWER.
NOT SURE I BELIEVE THIS FEATURE EITHER AS IT IS USUALLY DRY BETWEEN
SYSTEMS LIKE THIS. SO HAVE CONTINUED TO KEEP THE POPS DRY OVER THE
REGION.
FRIDAY NIGHT...WITH THE RETURN FLOW JUST STARTING, WE SHOULD
CONTINUE TO REMAIN DRY. THE GFS IS SUGGESTING THAT THINGS CONTINUE
AND FALL APART OVERNIGHT, BUT THAT SEEMS A LITTLE TOO AGGRESSIVE,
PROBABLY FROM THE EXCESSIVE MOISTURE. THE 500 MB WAVE TO THE NW WILL
BE IN W UPPER BY THE 12Z, SO WILL THINK THAT THE CLOUDS MAY START TO
MOVE INTO THE REGION BY THE MORNING. THE NAM IS WAY TOO WEST AS
WELL, AND IT LOOKS LIKE IT IS KICKING OFF RAIN FROM SMALL AMOUNTS OF
CAPE (BMJ PARAMETRIZATION). SO IF THINGS SHOULD REMAIN DRY
OVERNIGHT IF IT DOES DURING THE DAY. THE ONLY EXCEPTION TO THAT IS
THE MOISTURE THAT IS EDGING ITS WAY NORTH THAT COULD GET INTO
GLADWIN AND ARENAC COUNTIES.
SATURDAY...GFS CONTINUES TO LOOK WAY TOO WET COMPARED TO THE WAY
THIS YEAR HAS TRENDED. WILL CONTINUE THE DRY FORECAST. THINK THAT
THIS DAY WILL REMAIN DRY. MOISTURE IS RATHER THIN ON THE ECMWF WITH
LESS AMPLITUDE IN THE WAVES MOVING INTO THE THE GREAT LAKES
OVERNIGHT. WILL KEEP THE NIGHT DRY AS WELL. THINK THAT THE GFS AND
NAM ARE BOTH SHOWING SOME CONVECTIVE FEEDBACK/PARAMETRIZATION OVER
DEVELOPMENT OR MOISTURE BIAS. ITS HARD TO TAKE THESE MODELS TOO
SERIOUSLY.
EXTENDED (SUNDAY THROUGH WEDNESDAY)...SUNDAY, MOISTURE GETS INTO THE
REGION WITH THE 500 MB SHORTWAVE TROUGH THAT HAS BEEN MOVING INTO
THE REGION SATURDAY NIGHT. THIS HAS THE POTENTIAL TO KICK OFF
AFTERNOON THUNDERSTORMS, ESPECIALLY IN NE LOWER AS THE WAVE MOVES
THROUGH. MONDAY, CONTINUED TO PUSH THE POPS DOWN AS ONE WAVE MOVES
OFF, AND THE NEXT WAVE IS STILL UPSTREAM. THERE IS A BETTER JET
STREAK FORMING ALONG THE BOUNDARY WATERS AREA, AND LOOKS LIKE DRIVES
MOST OF THE DYNAMICS TO THE NORTH IN LAKE SUPERIOR. THIS KEEPS THE
THUNDER POTENTIAL MAINLY IN E UPPER AND IN THE TIP OF THE MIT. GFS
HAS BACKED OFF ON THE SFC LOW THAT SPUN UP ON LAST NIGHT`S RUN. IT
IS IN BETTER AGREEMENT WITH THE ECMWF. SO THE RAIN STARTS OVERNIGHT.
TUESDAY, LOOKS LIKE A SECONDARY WAVE MOVES THROUGH THE STATE PUSHING
THUNDER INTO MORE OF N LOWER. GFS IS NOW BOMBING A SFC LOW TUESDAY
NIGHT OVER THE WESTERN GREAT LAKES. WHILE THE ECMWF HAS A SFC TROUGH
AND DECENT NW FLOW. LOW POPS ARE EXPECTED, BUT NOTHING AS SEVERE AS
THE GFS IDEA. WEDNESDAY, NOW THE MODELS FLIP WITH THE ECMWF HAVING
ALL THE RAIN IN NW FLOW AND THE TROUGH SINKING SLOWLY THROUGH THE
FORECAST AREA. THE GFS HAS MAJOR SUBSIDENCE BEHIND THE LOW. GUESS,
IF I GO WITH THE ECMWF WITH LESS DEVELOPED LOW/SFC TROUGH, SHOULD GO
WITH IT, WITH THE WEAKER SFC HIGH, AND LESS SUBSIDENCE. SO WILL
CONTINUE THE POPS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1257 PM EDT THU JUL 12 2012
AS QUIET AS IT GETS IN THE AVIATION DEPARTMENT THE NEXT 24
HOURS...WITH HIGH PRESSURE IN CONTROL AND MAINLY CLEAR SKIES.
LAKE BREEZES AT OR UNDER 10 KNOTS WILL CONTINUE THROUGH EARLY
EVENING...GIVING WAY TO LIGHT OR CALM WINDS THROUGH THE NIGHT AND
A RETURN TO SLIGHTLY STRONGER SOUTHERLY WINDS UP TO 10 KNOTS INTO
MIDDAY FRIDAY.
&&
.MARINE...
ISSUED AT 335 AM EDT THU JUL 12 2012
HIGH PRESSURE WILL REMAIN DOMINANT FOR THE NEXT FEW DAYS...WITH
LIGHT WINDS/WAVES THROUGH FRIDAY NIGHT. TREND FOR INCREASE IN WIND
SPEEDS DURING THE DAY WITH LAKE BREEZES DEVELOPING EVERYWHERE BY
AFTERNOON.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...LAWRENCE
SYNOPSIS...JL
SHORT TERM...BA
LONG TERM...JL
AVIATION...LAWRENCE
MARINE...BA
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1004 AM EDT THU JUL 12 2012
.SYNOPSIS...
ISSUED AT 335 AM EDT THU JUL 12 2012
HIGH PRESSURE WILL REMAIN OVER THE GREAT LAKES REGION THROUGH THE
REMAINDER OF THE WEEK...BRINGING WITH IT MODERATING TEMPERATURES AND
DRY WEATHER. TEMPERATURES WILL SLOWLY CLIMB INTO THE MID AND UPPER
80S THROUGH THE WEEK...AND INTO THE UPCOMING WEEKEND.
&&
.UPDATE...
ISSUED AT 1004 AM EDT THU JUL 12 2012
ONLY MINOR CHANGES NEEDED TO GOING FORECAST...WITH THE MAIN ONE
BEING TO FURTHER LOWER AFTERNOON DEW POINTS. SETUP ACROSS THE
REGION HAS CHANGED LITTLE FROM THIS TIME YESTERDAY...FEATURING
OVERALL FAIRLY FLAT FLOW ALOFT OVER THE GREAT LAKES...WHILE
EXPANSIVE AND ELONGATED LOW LEVEL RIDGING RESIDES FROM THE
NORTHEAST/MID ATLANTIC STATES RIGHT ON BACK INTO OUR NECK OF THE
WOODS. AIRMASS REMAINS QUITE DRY FOR THIS TIME OF THE
YEAR...LIKELY A FEEDBACK MECHANISM FROM THE ONGOING VERY DRY
CONDITIONS JUST TO OUR SOUTHWEST. PWATS HAVE INCHED UP OVER THE
PAST 24 HOURS...UP TO A WHOPPING 0.57 INCHES PER 12Z APX
RAOB...BUT MOST OF THAT MOISTURE IS UP TOP...WHILE THE LOW LEVELS
HAVE ACTUALLY FURTHER DRIED OUT FROM THIS TIME YESTERDAY.
DESPITE WHAT SHOULD BE LIMITED MIXING TODAY GIVEN VERY LIGHT WIND
FIELDS...MIXING UP TO 800MB STILL PUTS MUCH OF NORTHERN LOWER
FIRMLY IN AN AXIS OF VERY DRY AIR ALOFT. HINTS ON MET GUIDANCE AND
LATEST HRRR NUMBERS BOOST CONFIDENCE THAT READINGS MAY DIP INTO
THE 30S IN A NUMBER OF SPOTS THIS AFTERNOON (AWAY FROM THE LAKE
BREEZE INFLUENCE NEAR THE COASTS...OF COURSE). COMBINED WITH HIGHS
A COUPLE OF DEGREES WARMER THAN YESTERDAY GIVEN WEAK ONGOING WARM
ADVECTION...SHOULD SEE MIN RH VALUES DOWN INTO THE TEENS IN
SPOTS...WITH GOING ELEVATED FIRE DANGER MENTION DEFINITELY
WARRANTED.
OTHERWISE...NO MAJOR CHANGES MADE TO THE FORECAST...SAVE FOR
RAISING HIGHS A FEW DEGREES CLOSER TO THE WATER BEFORE LAKE
BREEZES KICK IN AFTER 17Z. COULD ALSO SEE A RENEWED CU FIELD
CLOSER TO LAKE SUPERIOR INTO EARLY AFTERNOON WITHIN AN AXIS OF
DEEPER MOISTURE LAID OUT OVER THE U.P...WITH EVEN AN OUTSIDE
CHANCE AT A ROGUE BRIEF SHOWER...THOUGH PROBABLY NOT GIVEN SLOWLY
GROWING CAP UP AROUND 600MB. OUTSIDE OF THAT...SIMPLY A BEAUTIFUL
SUMMERTIME DAY ACROSS NORTHERN MICHIGAN. ENJOY!
UPDATE ISSUED AT 636 AM EDT THU JUL 12 2012
NO CHANGES TO THE GOING FORECAST. BATCH OF MID CLOUD PRESENT
ACROSS EASTERN UPPER MICHIGAN AND THE STRAITS...WITH SOME HIGH
CLOUDS (CONVECTIVE DEBRIS) ALSO NOSING INTO THE NRN PART OF THE
STATE. HAVE PARTLY-MOSTLY SUNNY SKIES UP THAT WAY ALREADY.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 335 AM EDT THU JUL 12 2012
LOW AMPLITUDE 4-WAVE LONG WAVE HEMISPHERIC PATTERN CURRENTLY IN
PLACE WITH SUBTLE TROUGHING ACROSS EASTERN NOAM. LITTLE CHANGE IN
THIS PATTERN OVER THE NEXT FEW DAY WITH THE MAIN FLOW BOTTLED UP
ACROSS CANADA. AT THE SFC...BROAD HIGH PRESSURE REMAINS NEARLY
FIXED FROM MICHIGAN TO THE ATLANTIC COAST WITH STRONGER WARM/MOIST
ADVECTION FLOW PRESENT ACROSS SUPERIOR INTO ONTARIO PRODUCING A
FEW ROUNDS OF CONVECTION UP THAT WAY. ONE SMALL MCS IS CAUGHT UP
IN RELATIVE WEAK FLOW JUST NORTH OF LAKE SUPERIOR...DRIFTING
VERY SLOWLY SOUTHWARD TOWARD LAKE SUPERIOR AND PRODUCING A NICE
DUMPING OF RAIN FOR THAT AREA.
TODAY AND TONIGHT...HIGH PRESSURE WILL CONTINUE TO DOMINATE TODAY AND
TONIGHT WITH FAIR CONDITIONS PERSISTING. CONVECTION JUST NORTH OF
SUPERIOR NOT MAKING ANY SOUTHWARD PROGRESS...DYING AS IT GETS INTO
THE MORE STABLE ENVIRONMENT SOUTH OF ONTARIO. SO...THIS FEATURE
POSES LITTLE IF ANY PRECIP THREAT TO THIS CWA...BUT OF COURSE WILL
WATCH IT. SOME ASSOCIATED CLOUD COVER MAY DRIFT INTO THE NRN PARTS
OF THE CWA HOWEVER...ALONG WITH A BATCH OF MID CLOUD THAT HAS
DEVELOPED OVER EASTERN UPPER MICHIGAN AND THE STRAITS. OTHERWISE...
GIVEN THE VERY DRY AIRMASS OVER THE REGION...DAYTIME CU POTENTIAL
LOOKING PRETTY LOW TODAY...UNLESS SFC DEWPOINTS STAY UP A LITTLE
HIGHER THAN EXPECTED.
TEMPERATURES...FORECAST SOUNDINGS SUGGEST SLIGHTLY WARMER DAYTIME
HIGHS AS COMPARED TO WEDNESDAY...SOLID MID 80S...A LITTLE COOLER
NEAR THE LAKE SHORES WITH LIGHT WINDS/LAKE BREEZES SETTING UP BY
AFTERNOON. LIGHT WINDS/LOW DEWPOINTS AND MAINLY CLEAR SKIES WILL
ALLOW TEMPS TO DROP BACK INTO THE 50S TONIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 335 AM EDT THU JUL 12 2012
FRIDAY...THE GFS HAS MORE SFC MOISTURE THAN THE ECMWF AND ALSO HAS A
MORE DEVELOPED 500 MB WAVE MOVING INTO W LAKE SUPERIOR. THE GFS ALSO
HAS MUCH MORE MOISTURE WITH THE SYSTEM IN THE SE STATES WHICH SPILLS
UP NORTH TO US. THINK THAT THIS IS TOO MOIST STILL AS THE SFC
MOISTURE BIAS, SHOWN IN THE SFC DEWPOINTS, IS TRYING TO DEVELOPING
THINGS TOO MUCH. INTERESTINGLY, THE MOISTURE AT IN THE 700-500 MB
LAYER, LOOKS THE SAME. SO IF THE SFC MOISTURE WASN`T SO HIGH ON GFS
WOULD THINK IT WOULD LOOK LIKE THE ECMWF. NAM TRIES TO DEVELOP
SOMETHING LATE(AFTER 21Z) IN S LOWER AND MOVES IT UP INTO NW LOWER.
NOT SURE I BELIEVE THIS FEATURE EITHER AS IT IS USUALLY DRY BETWEEN
SYSTEMS LIKE THIS. SO HAVE CONTINUED TO KEEP THE POPS DRY OVER THE
REGION.
FRIDAY NIGHT...WITH THE RETURN FLOW JUST STARTING, WE SHOULD
CONTINUE TO REMAIN DRY. THE GFS IS SUGGESTING THAT THINGS CONTINUE
AND FALL APART OVERNIGHT, BUT THAT SEEMS A LITTLE TOO AGGRESSIVE,
PROBABLY FROM THE EXCESSIVE MOISTURE. THE 500 MB WAVE TO THE NW WILL
BE IN W UPPER BY THE 12Z, SO WILL THINK THAT THE CLOUDS MAY START TO
MOVE INTO THE REGION BY THE MORNING. THE NAM IS WAY TOO WEST AS
WELL, AND IT LOOKS LIKE IT IS KICKING OFF RAIN FROM SMALL AMOUNTS OF
CAPE (BMJ PARAMETRIZATION). SO IF THINGS SHOULD REMAIN DRY
OVERNIGHT IF IT DOES DURING THE DAY. THE ONLY EXCEPTION TO THAT IS
THE MOISTURE THAT IS EDGING ITS WAY NORTH THAT COULD GET INTO
GLADWIN AND ARENAC COUNTIES.
SATURDAY...GFS CONTINUES TO LOOK WAY TOO WET COMPARED TO THE WAY
THIS YEAR HAS TRENDED. WILL CONTINUE THE DRY FORECAST. THINK THAT
THIS DAY WILL REMAIN DRY. MOISTURE IS RATHER THIN ON THE ECMWF WITH
LESS AMPLITUDE IN THE WAVES MOVING INTO THE THE GREAT LAKES
OVERNIGHT. WILL KEEP THE NIGHT DRY AS WELL. THINK THAT THE GFS AND
NAM ARE BOTH SHOWING SOME CONVECTIVE FEEDBACK/PARAMETRIZATION OVER
DEVELOPMENT OR MOISTURE BIAS. ITS HARD TO TAKE THESE MODELS TOO
SERIOUSLY.
EXTENDED (SUNDAY THROUGH WEDNESDAY)...SUNDAY, MOISTURE GETS INTO THE
REGION WITH THE 500 MB SHORTWAVE TROUGH THAT HAS BEEN MOVING INTO
THE REGION SATURDAY NIGHT. THIS HAS THE POTENTIAL TO KICK OFF
AFTERNOON THUNDERSTORMS, ESPECIALLY IN NE LOWER AS THE WAVE MOVES
THROUGH. MONDAY, CONTINUED TO PUSH THE POPS DOWN AS ONE WAVE MOVES
OFF, AND THE NEXT WAVE IS STILL UPSTREAM. THERE IS A BETTER JET
STREAK FORMING ALONG THE BOUNDARY WATERS AREA, AND LOOKS LIKE DRIVES
MOST OF THE DYNAMICS TO THE NORTH IN LAKE SUPERIOR. THIS KEEPS THE
THUNDER POTENTIAL MAINLY IN E UPPER AND IN THE TIP OF THE MIT. GFS
HAS BACKED OFF ON THE SFC LOW THAT SPUN UP ON LAST NIGHT`S RUN. IT
IS IN BETTER AGREEMENT WITH THE ECMWF. SO THE RAIN STARTS OVERNIGHT.
TUESDAY, LOOKS LIKE A SECONDARY WAVE MOVES THROUGH THE STATE PUSHING
THUNDER INTO MORE OF N LOWER. GFS IS NOW BOMBING A SFC LOW TUESDAY
NIGHT OVER THE WESTERN GREAT LAKES. WHILE THE ECMWF HAS A SFC TROUGH
AND DECENT NW FLOW. LOW POPS ARE EXPECTED, BUT NOTHING AS SEVERE AS
THE GFS IDEA. WEDNESDAY, NOW THE MODELS FLIP WITH THE ECMWF HAVING
ALL THE RAIN IN NW FLOW AND THE TROUGH SINKING SLOWLY THROUGH THE
FORECAST AREA. THE GFS HAS MAJOR SUBSIDENCE BEHIND THE LOW. GUESS,
IF I GO WITH THE ECMWF WITH LESS DEVELOPED LOW/SFC TROUGH, SHOULD GO
WITH IT, WITH THE WEAKER SFC HIGH, AND LESS SUBSIDENCE. SO WILL
CONTINUE THE POPS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 636 AM EDT THU JUL 12 2012
SOLID VFR CONDITIONS THROUGH FRIDAY MORNING AS HIGH PRESSURE
REMAINS ACROSS THE STATE. BATCH OF MID CLOUD OVER EASTERN UPPER
MICHIGAN AND THE STRAITS MAY DRIFT INTO THE PLN TERMINAL SITE
THROUGH THIS MORNING...ALONG WITH SOME HIGH LEVEL CONVECTIVE
DEBRIS CLOUD. OTHERWISE...FAIR SKIES AND LIGHT WINDS WILL
DOMINATE WITH LAKE BREEZE WIND DIRECTIONS DEVELOPING THIS
AFTERNOON. CALM WINDS TONIGHT.
&&
.MARINE...
ISSUED AT 335 AM EDT THU JUL 12 2012
HIGH PRESSURE WILL REMAIN DOMINANT FOR THE NEXT FEW DAYS...WITH
LIGHT WINDS/WAVES THROUGH FRIDAY NIGHT. TREND FOR INCREASE IN WIND
SPEEDS DURING THE DAY WITH LAKE BREEZES DEVELOPING EVERYWHERE BY
AFTERNOON.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...LAWRENCE
SYNOPSIS...JL
SHORT TERM...BA
LONG TERM...JL
AVIATION...BA
MARINE...BA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
357 PM CDT THU JUL 12 2012
.DISCUSSION...
TONIGHT AND FRIDAY...TRANSITIONING FLOW ALOFT ALONG WITH AN
INCOMING FRONTAL SYSTEM WILL MAKE FOR A BIT OF A MESSY FCST OVER
THE NEXT 12-24 HOURS. LARGE UPPER RIDGE CENTERED OVER THE
4-CORNERS REGION WILL RETROGRADE BACK TO THE SW...WANING ITS
INFLUENCE OVER THE REGION TONIGHT. MEANWHILE...AS THE RIDGE BACKS
OFF...A COMPACT UPPER LEVEL LOW WILL DROP IN FROM MANITOBA AND
HELP NUDGE ALONG THE FRONTAL SYSTEM. AN INCREASE IN MID- AND
UPPER-LEVEL MOISTURE BEING DRAGGED IN FROM THE PACIFIC ALONG WITH
MUCAPES INCRG TO THE 1500-2000 J/KG RANGE MAY BE CAPABLE OF
PRODUCING ISOLD STRONG TO SEVERE TSTMS TNGT THRU TMRW. HOWEVER...
POOR LAPSE RATES SHOULD MITIGATE ANY SUBSTANTIAL COVERAGE. HAVE
CAPPED POPS IN THE CHC RANGE SINCE THIS WILL NOT BE ANY KIND OF
WASHOUT BUT RATHER SHORT-DURATION PRECIP OF THE HIT-AND-MISS
VARIETY. POPS INCRS TNGT WITH HIGHEST POPS DURG THE DAY ON FRIDAY.
HAVE ALSO KEPT THE HIGHEST QPF OVER NRN PORTIONS OF THE AREA...BUT
THAT SAID...AM NOT LOOKING FOR SITES TO RECEIVE MORE THAN 0.25
INCHES OF RAIN. TEMPS WILL CONTINUE THEIR WARMING TREND THRU THE
NEXT 24 HRS AS LOW LEVEL SOUTHERLY FLOW TAKES HOLD OVER THE
REGION. WARM SECTORING WILL PLAY A PART AS THE COLD FRONT SLOGS
ITS WAY INTO WESTERN AND CENTRAL MN...ALTHOUGH TEMPERED A BIT BY
SCATTERED SHWRS/TSTMS. HIGHS WILL REACH THE UPPER 80S TO ARND 90.
FRIDAY NIGHT THROUGH SUNDAY...ELEVATED INSTABILITY WILL REMAIN IN
PLACE THRU SATURDAY AHEAD OF THE CDFNT WHILE MODEST UPPER FORCING
ALSO SLOWLY PROGRESSES THRU THE REGION. LAPSE RATES STILL ARE NOT
OVERLY IMPRESSIVE...BUT RELATIVELY WEAK CAPPING SHOULD PROMOTE
SHWR/TSTM ACTIVITY ONGOING FRI EVENING THAT WILL CONTINUE SLOWLY
SHIFT E THRU THE DAY SAT INTO SAT EVE. AGAIN...CAPPED POPS IN THE
CHC RANGE DUE TO LARGE UNCERTAINTY WITH THE COVERAGE/LOCATION OF
CONVECTIVE ACTIVITY. IT MAY AGAIN WELL BE THAT LOCATIONS THAT
RECEIVED RAINFALL FRIDAY MAY SEE IT AGAIN ON SATURDAY WHILE SOME
SPOTS SEE PRECIP ON NEITHER DAY...AGAIN THE HIT-AND-MISS VARIETY.
THE CDFNT WILL PUSH INTO ERN MN AND WRN WI SAT EVE THEN EXIT THE
REGION SAT NIGHT INTO SUN...RESULTING IN A DRY DAY ON SUN. STILL
THE POSSIBILITY IS THERE FOR ISOLD STRONG TO SEVERE TSTMS FRI EVE
BUT AS THE FORCING SHIFTS E...THE THREAT WILL DIMINISH FRI NIGHT
INTO SAT. EVEN WITH THE COLD FROPA...THERE WILL NOT BE A DROP IN
TEMPS BEHIND AS A WARM DOME OF HIGH PRESSURE OVER THE 4-CORNERS
REGION LOOKS TO RE-EXTEND ITSELF INTO THE NORTHERN PLAINS AND
UPPER MISSISSIPPI RIVER VALLEY. BY SUNDAY...HIGHS WILL REACH THE
LOWER 90S FOR MUCH OF THE WFO MPX CWFA.
MONDAY THROUGH WEDNESDAY...STRONG WARMING WILL CONTINUE INTO
MONDAY AS THE UPPER LEVEL RIDGE AXIS SHIFTS ACRS THE REGION...
RESULTING IN STRONG CAPPING DESPITE INCREASED HUMIDITY AND
TEMPERATURES. MAY SEE SOME ISOLD ACTIVITY OVER NRN PORTIONS OF THE
AREA MONDAY...BUT THE MAIN STORY WILL BE THE HEAT. HIGHS WILL
REACH THE MIDDLE TO POSSIBLY UPPER 90S WHILE DEWPOINTS INCREASE TO
ARND 70. THIS WILL NUDGE HEAT INDEX VALUES INTO THE 100-105
DEGREES RANGE...SO THIS WITH LOWS IN THE LOW TO MID 70S SUN NIGHT
AND MON NIGHT MAY CREATE HEAT ADVISORY CONDITIONS. AS THE BUBBLE
HIGH SHIFTS E...THE HEAT WILL THEN TRANSITION INTO CENTRAL WI TUE
THEN LOSE ITS INFLUENCE BY WED AS NORTHERLY SFC WINDS WITH NW
UPPER FLOW BRINGS A SLIGHT COOLDOWN TO THE AREA. AS FOR PRECIP...
NOT A WHOLE LOT TO SPEAK UP DURING THE FIRST HALF OF THE WEEK AS
SIDE FROM A FEW WEAK UPPER LEVEL DISTURBANCES GLIDING THROUGH NRN
MN WHICH MAY EXTEND ENOUGH S INTO CENTRAL MN TO SPARK OFF ISOLD
CONVECTION. CAPPED POPS AT 20 PERCENT...WITH MANY LOCATIONS NOT
EVEN HAVING ANYTHING MENTIONABLE THROUGH THE PERIOD.
&&
.AVIATION.../18Z TAF ISSUANCE/
EXPECT VFR CONDITIONS FOR THE MAJORITY OF THE TAF PERIOD...WITH
THE EXCEPTION BEING LATER THIS AFTERNOON AND EVENING IN CENTRAL
AND WESTERN MINNESOTA AS SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
DEVELOP. AS OF EARLY AFTERNOON...A FEW SHOWERS...MOSTLY MID LEVEL
CLOUDS AND VIRGA ARE NOTED NORTHEAST OF RWF AND WEST OF MSP. WE DO
EXPECT DEVELOPMENT OF SOME SHOWER ACTIVITY OVER THE WESTERN HALF
OF MN THIS LATER THIS AFTERNOON AND INTO THE EVENING HOURS DUE TO
DIURNAL HEATING COUPLED WITH A WEAK COLD FRONT/UPPER LEVEL TROUGH
THAT IS SLOWLY MEANDERING FROM EASTERN ND AND WILL BE LOCATED OVER
CENTRAL MN BY 12Z FRIDAY. WE MAY SEE SOME ISOLATED STRONG TO
SEVERE STORMS ALONG THE MN/ND BORDER THIS AFTERNOON AND EVENING
AND THAT WILL TRANSLATED EAST INTO CENTRAL AND EASTERN MN BY THE
21-24Z TIME FRAME. LEFT THE POSSIBILITY OF TS OUT OF THE TAFS FOR
NOW. DO NOT HAVE CONFIDENCE THAT TS ACTIVITY WILL BE WIDESPREAD
ENOUGH TO MENTION AT THIS POINT IN TIME. THERE ARE HINTS THAT
IN THE MEAN TIME...EXPECT BREEZY SOUTHERLY WINDS THIS AFTERNOON.
KMSP...SHOWERS AND THUNDERSTORMS WILL BE SLOW TO ARRIVE IN THE
METRO AREA...SO HAVE NO SHOWER ACTIVITY UNTIL 12Z...AND TRIED TO
TIME THE BEST CHANCE FOR SHOWER AND OR THUNDER WITH A TEMPO GROUP
FRIDAY AFTERNOON. HRRR SHOWS PRECIPITATION MOVING TOWARD MSP
AROUND 03Z OR LATER BUT VERY WEAK ECHOS AND WRF SUPPORTS NO SHRA
UNTIL AFTER 12Z. HENCE SHRA AT 12Z AND PROBABLY LATER.
/OUTLOOK/
SATURDAY...VFR WITH SHRA ENDING. WINDS NW AT 5 TO 10KTS.
SUNDAY...VFR. WINDS W AT 5-10 KTS.
MONDAY...VFR. WINDS S-SW 10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JPC/DRL
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
102 PM CDT THU JUL 12 2012
.UPDATED FOR 18Z AVIATION...
&&
.DISCUSSION...
/ISSUED AT 404 AM CDT THU JUL 12 2012/
DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST... WITH THE
PRIMARY ISSUE BEING CHANCES FOR PCPN TODAY THROUGH FRIDAY AS
THE 850MB THETA-E RIDGE BUILDS INTO THE AREA... BOOSTING PW VALUES
AND HELPING TO KEEP A CONVECTIVELY UNSTABLE AIRMASS IN PLACE FOR
SEVERAL DAYS. A FEW SHORTWAVES AND A SLOWLY MOVING SURFACE TROUGH
WILL MIGRATE ACROSS THE REGION THROUGH THE SATURDAY... WITH THE
BEST CHANCES FOR PCPN BEING TIED TO THOSE FEATURES IN CONJUNCTION
WITH THE DIURNAL CONVECTIVE CYCLE. MADE SOME ATTEMPT TO LIMIT BEST
PCPN CHANCES TO NARROWER WINDOWS IN TIME... BUT POPS STILL MAKE IT
LOOK TO BE WETTER THAN IT WILL SEEMS SINCE THERE CERTAINLY DOESN/T
LOOK TO BE A PROLONGED PERIOD OF RAIN... SIMPLY PERIODIC CHANCES
FOR SHRA/TSRA. IN THE BIG PICTURE... THE UPPER FLOW LOOKS TO
REMAIN MAINLY ZONAL OR FROM THE NORTHWEST THROUGH THE WEEKEND...
WITH THE HEART OF THE JET REMAINING NORTH OF THE AREA. THERE IS
SOME INDICATION THAT THE UPPER RIDGE COULD MIGRATE EAST TO THE
CENTER OF THE CONUS BY THE MIDDLE OF NEXT WEEK... ALTHOUGH THE GFS
AND ECMWF DO NOT AGREE ON THAT SCENARIO... AND THEIR RESPECTIVE
ENSEMBLES STILL OFFER A MULTITUDE OF SOLUTIONS. THAT CHANGE WOULD
OBVIOUSLY LEAD US BACK INTO A PERIOD OF WELL ABOVE NORMAL
TEMPERATURES ONCE AGAIN... BUT EVEN WITHOUT THAT WE STILL LOOK TO
KEEP READINGS THAT ARE SOMEWHAT ABOVE NORMAL AS WE/VE SEEN FOR THE
PAST SEVERAL DAYS.
FOR TODAY WE SHOULD SEE THE CHANCE FOR SHRA/TSRA CREEP INTO THE
AREA FROM WEST TO EAST... ALTHOUGH THE BEST FORCING ASSOCIATED
WITH THE SHORTWAVE CURRENTLY NEAR THE NORTH DAKOTA/CANADA BORDER
WILL OBVIOUSLY STAY NORTH OF OUR AREA. HOWEVER... A SECOND JET MAX
AND ASSOCIATED SHORTWAVE CAN BE SEEN OVER WYOMING... AND THIS WILL
WORK EAST THROUGH THE DAY... AND HELP TO NUDGE THE 850MB THETA-E
RIDGE FARTHER EAST ACROSS OUR AREA... AND ENHANCE CHANCES FOR PCPN
LATER TODAY INTO TONIGHT. THE SURFACE TROUGH OVER THE PLAINS WILL
GRUDGINGLY MOVE EAST OVER THE UPCOMING 48 HOURS... WHICH LEADS TO
A PROLONGED PERIOD WITH SOME CHANCE FOR SHRA/TSRA ACROSS OUR
REGION. 850-500MB DIFFERENTIAL THETA-E PROGS FROM THE NAM BRING
CONVECTIVELY UNSTABLE AIR INTO THE AREA TODAY... AND LINGER IT
INTO SATURDAY. LOW LEVEL FORCING FROM THE SURFACE-850MB TROUGH
WILL COMBINE BEST WITH MID-UPPER LEVEL FORCING ON FRIDAY AS A
DECENT SHORTWAVE DROPS EAST-SOUTHEAST ACROSS THE AREA. ONCE THE
INSTABILITY BUILDS IN TODAY... WE SHOULD SEE MUCAPE VALUES OVER THE
NEXT FEW DAYS AOA 1500 J/KG MUCH OF THE TIME. POPS LOOK TO BE
MAXIMIZED FRIDAY INTO FRIDAY EVENING AS THE UPPER WAVE MOVES
THROUGH AND HELPS DRAG THE SURFACE TROUGH EASTWARD. FAVORED A
BLEND OF THE ECMWF AND NAM... WHICH ARE SLIGHTLY MORE PROGRESSIVE
THAN THE GFS... AND MANAGE TO KICK MOST OF THE ACTIVITY OUT OF OUR
AREA FOR SATURDAY NIGHT AND SUNDAY. IN TERMS OF SEVERE WEATHER
POTENTIAL... THINGS LOOK FAIRLY LIMITED DUE TO A LACK OF
SIGNIFICANT DEEP LAYER SHEAR THROUGH THE PERIOD. HOWEVER... CAPE
VALUES WILL BE SUFFICIENT FOR A FEW STORMS TO BECOME SEVERE...
MAINLY ON FRIDAY WITH HAIL BEING THE PRIMARY THREAT.
ANOTHER SURFACE LOW WILL TAKE SHAPE OVER THE NORTHERN PLAINS BY
MONDAY... AND WORK ACROSS THE UPPER MIDWEST AND NORTHERN GREAT
LAKES MONDAY AFTERNOON THROUGH TUESDAY. AT THIS POINT... PCPN
LOOKS TO BE MOST FOCUSED NEAR THE WARM FRONTAL BOUNDARY WHICH WILL
LIKELY BE OVER NORTHERN MINNESOTA... SO TAPERED POPS FROM NORTH TO
SOUTH MONDAY AND TUESDAY... AND TRIED TO KEEP THINGS DRY OVER AT
LEAST THE SOUTHERN PORTION OF THE AREA. KEPT SOME LOW POPS INTO
WEDNESDAY TO KEEP SOME CONTINUITY WITH EARLIER MODEL SOLUTIONS AND
THE PREVIOUS FORECASTS... BUT THE MOST RECENT GUIDANCE SUGGESTS A
DECENT SURFACE HIGH SHOULD PUSH SOUTH INTO THE AREA AND DISPLACE
THE BAROCLINIC ZONE SOUTH OF THE AREA. SO... SUBSEQUENT FORECASTS
MAY BE ABLE TO REMOVE POPS FOR WEDNESDAY IF THIS TREND PERSISTS.
&&
.AVIATION.../18Z TAF ISSUANCE/
EXPECT VFR CONDITIONS FOR THE MAJORITY OF THE TAF PERIOD...WITH
THE EXCEPTION BEING LATER THIS AFTERNOON AND EVENING IN CENTRAL
AND WESTERN MINNESOTA AS SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
DEVELOP. AS OF EARLY AFTERNOON...A FEW SHOWERS...MOSTLY MID LEVEL
CLOUDS AND VIRGA ARE NOTED NORTHEAST OF RWF AND WEST OF MSP. WE DO
EXPECT DEVELOPMENT OF SOME SHOWER ACTIVITY OVER THE WESTERN HALF
OF MN THIS LATER THIS AFTERNOON AND INTO THE EVENING HOURS DUE TO
DIURNAL HEATING COUPLED WITH A WEAK COLD FRONT/UPPER LEVEL TROUGH
THAT IS SLOWLY MEANDERING FROM EASTERN ND AND WILL BE LOCATED OVER
CENTRAL MN BY 12Z FRIDAY. WE MAY SEE SOME ISOLATED STRONG TO
SEVERE STORMS ALONG THE MN/ND BORDER THIS AFTERNOON AND EVENING
AND THAT WILL TRANSLATED EAST INTO CENTRAL AND EASTERN MN BY THE
21-24Z TIME FRAME. LEFT THE POSSIBILITY OF TS OUT OF THE TAFS FOR
NOW. DO NOT HAVE CONFIDENCE THAT TS ACTIVITY WILL BE WIDESPREAD
ENOUGH TO MENTION AT THIS POINT IN TIME. THERE ARE HINTS THAT
IN THE MEAN TIME...EXPECT BREEZY SOUTHERLY WINDS THIS AFTERNOON.
KMSP...SHOWERS AND THUNDERSTORMS WILL BE SLOW TO ARRIVE IN THE
METRO AREA...SO HAVE NO SHOWER ACTIVITY UNTIL 12Z...AND TRIED TO
TIME THE BEST CHANCE FOR SHOWER AND OR THUNDER WITH A TEMPO GROUP
FRIDAY AFTERNOON. HRRR SHOWS PRECIPITATION MOVING TOWARD MSP
AROUND 03Z OR LATER BUT VERY WEAK ECHOS AND WRF SUPPORTS NO SHRA
UNTIL AFTER 12Z. HENCE SHRA AT 12Z AND PROBABLY LATER.
/OUTLOOK/
SATURDAY...VFR WITH SHRA ENDING. WINDS NW AT 5 TO 10KTS.
SUNDAY...VFR. WINDS W AT 5-10 KTS.
MONDAY...VFR. WINDS S-SW 10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
TRH/DRL
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
802 PM CDT FRI JUL 13 2012
.UPDATE...
ISSUED AT 750 PM CDT FRI JUL 13 2012
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE ACROSS
WEST CENTRAL ILLINOIS AND EAST CENTRAL AND SOUTHEAST MISSOURI THIS
EVENING ALONG AN OUTFLOW BOUNDARY FROM THIS AFTERNOONS CONVECTION.
GIVEN THE LOSS OF DIURNAL HEATING...SEVERE WEATHER IS NOT
ANTICIPATED...THOUGH SOME LOCATIONS COULD SEE VERY HEAVY
DOWNPOURS AND GUSTY WINDS. GIVEN THE SHORTWAVE PROGGED TO MOVE
INTO NORTHERN MISSOURI TONIGHT...EXPECT SOME ISOLATED STORMS TO
CONTINUE INTO THE OVERNIGHT HOURS ACROSS THE AREA.
TEMPERATURES ACROSS CENTRAL...NORTHEASTERN...AND EAST CENTRAL
MISSOURI HAVE COOLED DOWN SIGNIFICANTLY DUE TO PRECIPITATION
ACROSS THE AREA THIS AFTERNOON AND EVENING...THUS HAVE MADE
ADJUSTMENTS TO BOTH THE SHORT TERM TEMPERATURE TRENDS AND THE
OVERNIGHT LOW TEMPERATURES. ASIDE FROM TEMPERATURES...JUST MINOR
CHANGES TO OTHER FORECAST VARIABLES HAVE BEEN WARRANTED...AS THE
GOING FORECAST IS ON TRACK.
JP
&&
.SHORT TERM...
ISSUED AT 248 PM CDT FRI JUL 13 2012
(TONIGHT)
SCATTERED CONVECTION HAS DEVELOPED ACROSS THE NWRN HALF OF THE CWA
AHEAD OF A PV ANOMALY THAT WAS LOCATED OVER IA PER WATER VAPOR
IMAGERY AND RAP 1.5 PVU FIELDS. MAINLY PULSE-TYPE THUNDERSTORMS ARE
EXPECTED DUE TO WEAK SHEAR COMBINED WITH LITTLE CINH AND A FEW
THOUSAND J/KG OF CAPE. DRY SUBCLOUD LAYER AND A WELL-MIXED
BOUNDARY LAYER WILL ONCE AGAIN SUPPORT OCCASIONAL DOWNBURSTS WHEN
THE CORES OF THE STRONGEST STORMS COLLAPSE HOWEVER WIDESPREAD
SEVERE WEATHER IS NOT EXPECTED AT THIS TIME. PCPN COVERAGE SHOULD
DIMINISH LATER THIS EVENING WITH THE LOSS OF DAYTIME HEATING
HOWEVER A FEW AREAS OF ELEVATED CONVECTION MIGHT CONTINUE TO
PERCOLATE OVERNIGHT AS THE SHORTWAVE MOVES INTO NRN MO.
KANOFSKY/CARNEY
&&
.LONG TERM...
ISSUED AT 248 PM CDT FRI JUL 13 2012
(TOMORROW THROUGH NEXT THURSDAY)
VORT MAX MOVING ACROSS THE UPPER MIDWEST AND ITS ASSOCIATED SFC
TROF WILL PROVIDE BOTH A SOURCE OF LARGE SCALE LIFT AND A LOW
LEVEL FOCUSING MECHANISM FOR SCT TSRA/SHRA TOMORROW. GENERALLY
PULSE-TYPE THUNDERSTORMS ARE EXPECTED DUE TO WEAK SHEAR. ISOLATED
DIURNAL PCPN MAY REDEVELOP AND LINGER ACROSS THE SERN HALF OF THE
CWA ON SUN AND MON AS THE TROF SETTLES SEWD AND THE ELONGATED
VORTICITY AXIS SHEARS OUT.
A GRADUAL WARMING TREND IS EXPECTED OVER THE NEXT SEVERAL DAYS AS AN
UPPER LEVEL RIDGE BUILDS EWD. H85 TEMPERATURES OF 20-24 DEG C WOULD
SUPPORT AFTN HIGHS RANGING FROM THE MID 90S TO NEAR THE CENTURY
MARK. THE CENTRAL REGION ALLBLEND INITIALIZATION REMAINS
CONTAMINATED BY INCORRECT GFS OUTPUT /NCEP STAFF CONTINUE TO
TROUBLESHOOT BUT HAVE NOT YET IDENTIFIED THE SOURCE OF THE
PROBLEM/ THEREFORE I DEVIATED SIGNIFICANTLY FROM THE RECOMMENDED
INITIALIZATION TO REDUCE POPS AND RAISE TEMPS ON DAYS 4-7. A WEAK
SFC FRONT WILL APPROACH THE CWA ON WED/THU AND MOISTURE POOLING
AHEAD OF THE FRONT COULD DRIVE HEAT INDEX READINGS OVER 105 DEG F
IN SOME AREAS. ISOLATED TO SCATTERED THUNDERSTORMS WILL BE
POSSIBLE THROUGH THE EXTENDED PD HOWEVER THERE ARE NO STRONG
SIGNALS TO SUPPORT HIGHER THAN SCHC POPS ACROSS MO/IL WHICH
REMAINS IN A MODERATE TO SEVERE DROUGHT.
KANOFSKY
&&
.AVIATION...
ISSUED AT 527 PM CDT FRI JUL 13 2012
LINE OF SCATTERED THUNDERSTORMS FROM CENTRAL MISSOURI TO WEST
CENTRAL ILLINOIS HAS PRODUCED QUITE AN OUTFLOW THAT IS MOVING
SOUTHEAST TOWARD THE ST. LOUIS METRO TAF SITES. THIS WILL SWING
WINDS AROUND TO THE NORTHWEST WITH GUSTS TO 25KT AROUND 00Z.
COULD SEE THUNDERSTORMS REDEVELOP ALONG THIS BOUNDARY AND HAVE
INCLUDED A TEMPO FOR AN HOUR TO ACCOUNT FOR THIS. OF COURSE THIS
WILL BE NOWCASTED WITH LATEST RADAR TRENDS.
CONVECTION SHOULD WEAKEN WITH LOSS OF DAYTIME HEATING AFTER
SUNSET...ALTHOUGH A FEW SHOWERS COULD LINGER GIVEN VICINITY OF
WEAK MID/UPPER LEVEL TROF. WIND WILL BE LIGHT AND VARIABLE OVERNIGHT.
HAVE A RENEWED CHANCE OF SCATTERED CONVECTION TOMORROW AFTERNOON
FOR ST. LOUIS METRO TAF SITES AS 500MB SHEAR AXIS IS FORECAST TO
BE OVERHEAD. HAVE HANDLED THIS THREAT WITH A PROB30 GROUP.
SPECIFICS FOR KSTL...
EXPECT OUTFLOW BOUNDARY TO IMPACT TERMINAL AROUND 00Z WITH A WIND
SHIFT TO THE NORTHWEST AND GUSTS TO 25KT. ALSO WILL BE WATCHING TO
SEE IF THUNDERSTORMS CAN REDEVELOP ALONG THIS BOUNDARY.
OTHERWISE...VFR CONDITIONS EXPECTED OVERNIGHT WITH WINDS BECOMING
LIGHT AND VARIABLE. A RENEWED THREAT OF THUNDERSTORMS TOMORROW
AFTERNOON...BUT COVERAGE WILL REMAIN SCT...SO HAVE ONLY INCLUDED
A PROB30 GROUP AT THIS TIME.
CVKING
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1215 PM CDT THU JUL 12 2012
.AVIATION...18Z KGRI TAF. VFR CONDITIONS TO CONTINUE THROUGH THE
NEXT 24 HOURS. HIGH LEVEL CLOUDS NEAR 12000FT AGL WILL BE ON THE
INCREASE THIS AFTERNOON. SURFACE WINDS...AT AROUND 08KTS...WILL
START FROM THE SOUTHWEST EARLY THIS AFTERNOON...PERHAPS BACKING TO
MORE OF A SOUTH/SOUTHEASTERLY DIRECTION BY LATE AFTERNOON/EARLY
EVENING AND THEN BECOME LIGHT AND VARIABLE AFTER SUNSET.
VISIBILITY RESTRICTIONS ARE NOT EXPECTED THROUGH THE NEXT 24
HOURS.
&&
.PREV DISCUSSION... /ISSUED 1013 AM CDT THU JUL 12 2012/
UPDATE...MORNING UPPER AIR ANALYSIS INDICATES RIDGING OVER
THE SOUTHWESTERN CONUS...WITH A WEAK TROUGH OVER THE EAST. A MID
LEVEL SHORT WAVE IS NOTED OVER SOUTH CENTRAL CANADA AND THE NORTHERN
PLAINS...AND A MID LEVEL LOW IS EVIDENT NEARING THE NORTHWESTERN
CONUS FROM THE PACIFIC. WITH THE BULK OF MID AND UPPER LEVEL JET
ENERGY RELEGATED TO CANADA...WEAK MID AND UPPER LEVEL TROPOSPHERIC
FLOW PERSISTS OVER MUCH OF THE CONUS WITH ONLY A ~60KT UPPER LEVEL
JET STREAK TO SPEAK OF OVER THE NORTHWESTERN CONUS. WATER VAPOR
IMAGERY SHOWS PLENTY OF MID LEVEL MOISTURE OVER THE SOUTHWESTERN
CONUS...AS WELL AS THE SOUTHEASTERN CONUS. SOME OF THIS INCREASED
MID LEVEL MOISTURE IS BEGINNING TO SPILL OVER THE SOUTHWESTERN
CONUS RIDGE INTO THE CENTRAL PLAINS. AT THE SURFACE A RIDGE OF
HIGH PRESSURE IS NOTED OVER THE MISSISSIPPI VALLEY...WITH LOW
LEVEL RETURN FLOW TRYING TO ESTABLISH ITSELF ACROSS THE CENTRAL
PLAINS. A SURFACE TROUGH IS ALSO NOTED EXTENDING FROM THE DAKOTAS
INTO WESTERN NEBRASKA.
OVERALL TODAYS FORECAST REMAINS IN GREAT SHAPE. THE ONLY
SIGNIFICANT CHANGE AT THIS TIME WAS TO ADD SLIGHT CHANCE POPS
ACROSS OUR EXTREME NORTHWEST 21Z-00Z THIS AFTERNOON/EVENING.
CONSENSUS FROM OVERNIGHT GUIDANCE SUGGESTED ISOLATED CONVECTION
ACROSS OUR EXTREME NORTHWEST...WITH THE 12Z NAM AND HRRR REMAINING
CONSISTENT IN SUGGESTING THE SAME.
INTERESTING TO NOTE SURFACE DEW POINTS ACROSS THE EASTERN HALF OF
OUR CWA ARE REALLY SPIKING THIS MORNING...WITH DEW POINTS FROM
KJYR TO KK61 ALREADY IN THE MID TO UPPER 60S. THAT BEING
SAID...THIS MOISTURE RETURN HAS NOT YET INFILTRATED OUR
WEST/NORTHWESTERN CWA WHERE SURFACE DEW POINTS ARE STILL IN THE MID
TO UPPER 50S FROM KODX TO KLXN. SHORT TERM GUIDANCE SUGGESTS
SURFACE DEW POINTS ACROSS OUR WEST/NORTHWEST SHOULD REMAIN RELATIVELY
LOW WHEN COMPARED TO LOCATIONS FARTHER EAST...THUS RESULTING IN
RELATIVELY LOWER INSTABILITY VALUES. 12Z NAM SUGGESTS 0-1KM MLCAPE
VALUES WILL ONLY APPROACH 1000J/KG ACROSS OUR WEST/NORTHWEST THIS
AFTERNOON...WITH HIGHER VALUES FARTHER EAST. THE AFOREMENTIONED
WEAK MID TO UPPER LEVEL TROPOSPHERIC FLOW IS ALSO HELPING PROMOTE
WEAK DEEP LAYER BULK SHEAR VALUES...WITH THESE VALUES EXPECTED TO
REMAIN IN THE 20-30KT RANGE THIS AFTERNOON. GIVEN ALL
THIS...CONTINUE TO FIND IT HARD TO BELIEVE WE WILL SEE MUCH IN THE
WAY OF SEVERE WEATHER SHOULD DEEP CONVECTION BE REALIZED ACROSS
OUR NORTHWEST LATE THIS AFTERNOON/EVENING...BUT WHAT INSTABILITY
AND SHEAR ARE AVAILABLE MAY BE ENOUGH TO PROMOTE AN ISOLATED
STRONG STORM AND WILL CONTINUE SUCH WORDING IN THE HWO.
PREV DISCUSSION... /ISSUED 357 AM CDT THU JUL 12 2012/
SHORT TERM...TODAY THROUGH SATURDAY NIGHT.
A QUICK OVERNIGHT UPPER LEVEL ANALYSIS REVEALS A DEEPENING TROUGH
ACROSS THE SOUTHERN MISSISSIPPI RIVER VALLEY WHILE AN UPPER LEVEL
RIDGE CONTINUES TO LINGER ACROSS THE SOUTHWEST. A FEW UPPER LEVEL
TROUGHS CONTINUE TO TRAVERSE THE NORTHERN HALF OF THE UNITED STATES
POSITIONED ACROSS THE WEST COAST...DAKOTAS AND FURTHER NORTHEAST
ACROSS QUEBEC. AT THE SURFACE LOW PRESSURE ALSO CONTINUES TO SLIDE
EASTWARD ACROSS THE DAKOTAS WITH A LINGERING SURFACE TROUGH ACROSS
THE FRONT RANGE OF THE ROCKIES.
THE MAIN CONCERN FOR THE SHORT TERM PERIOD WILL FOCUS ON
PRECIPITATION CHANCES ACROSS THE AREA. BEGINNING THURSDAY AFTERNOON
AND OVERNIGHT...THE UPPER LEVEL TROUGH ACROSS THE DAKOTAS WILL SLIDE EAST
SOUTHEAST ALONG THE PERIPHERY OF THE UPPER LEVEL RIDGE. THIS IN
COMBINATION WITH THE SURFACE TROUGH PUSHING SOUTHEAST ACROSS THE
AREA WILL LIKELY GENERATE AT LEAST SOME CHANCES FOR SHOWERS AND
THUNDERSTORMS ACROSS PORTIONS OF NEBRASKA. BEST CHANCES REMAIN
ACROSS THE NORTH AND EAST PORTIONS OF THE FORECAST AREA...AS UPPER
LEVEL FORCING WILL LIKELY REMAIN FAR ENOUGH TO THE NORTH AND EAST TO
REALLY IMPACT A GOOD PORTION OF THE AREA.
CONTINUING INTO FRIDAY...MODELS CONTINUE TO LINGER THE SURFACE
BOUNDARY MAINLY JUST NORTH OF THE NEBRASKA KANSAS BORDER...WHILE THE
UPPER LEVEL TROUGH DEEPENS ACROSS MINNESOTA...IOWA...AND MISSOURI.
CONTINUED PRECIPITATION CHANCES THROUGH THE FRIDAY AND FRIDAY NIGHT
TIME FRAME...WITH THE BOUNDARY ACROSS THE AREA...AND WEAK UPPER
LEVEL WAVES SHIFTING THROUGH THE REGION. WHILE NOT EXACTLY THE BEST
SETUP...THERE COULD BE A FEW SHOWERS ESPECIALLY ACROSS THE EASTERN
PORTION OF THE FORECAST AREA THROUGH THE FRIDAY INTO FRIDAY NIGHT
TIME FRAME. CERTAINLY NOT EXPECTING A WASH OUT AT THIS TIME.
CONCERNING SEVERE WEATHER CHANCES...BOTH THIS AFTERNOON AND
FRIDAY...SHEAR WILL BE THE LIMITING FACTOR. AT LEAST 1500 TO 2000
J/KG REMAINS SITUATED ACROSS PORTIONS OF THE FORECAST AREA...ACROSS
THE NORTHWEST THIS AFTERNOON AND ACROSS THE FAR EAST ON FRIDAY.
HOWEVER...IN BOTH CASES DEEP LAYER SHEAR LOOKS TO BE NEAR OR LESS
THAN 30 KTS IN BOTH CASES. GIVEN A BIT MORE INSTABILITY ON
FRIDAY...AND FOR THE SAKE OF CONTINUITY WILL CONTINUE WITH STRONG
WORDING THIS AFTERNOON AND STRONG TO SEVERE WORDING ON FRIDAY.
REGARDING TEMPERATURES...WENT AHEAD AND RAISED HIGH TEMPERATURES A
FEW DEGREES BOTH TODAY...FRIDAY AND SATURDAY. GIVEN THAT MODEL
GUIDANCE WAS HIGHER ALL THREE DAYS AND AN ONE INSTANCE WAS AS MUCH
AS 10 DEGREES HIGHER...WENT AHEAD WITH A FEW DEGREES INCREASE. CLOUD
COVER AND THE SURFACE TROUGH COULD BE A LIMITING FACTOR BUT STILL
EXPECTING TEMPERATURES IN THE LOW TO MID 90S ACROSS THE FORECAST
AREA.
LONG TERM...SUNDAY THROUGH WEDNESDAY. THE EXTENDED PERIODS WILL
SEE A RETURN OF HOT CONDITIONS AS AN UPPER RIDGE OF HIGH PRESSURE
REBUILDS ACROSS THE INTERIOR CONUS. WITH THE HOT AIRMASS SETTLING
IN...HIGH TEMPERATURES SHOULD AVERAGE IN THE 90S...WITH LOWS IN THE
70S. HAVE KEPT CONDITIONS DRY IN THIS PATTERN...BUT WILL NEED TO
MONITOR SURFACE BOUNDARY FEATURES TOWARDS THE MIDDLE WEEK OF NEXT
WEEK AS FRONT MAY TRY TO SAG SOUTH INTO CENTRAL NEBRASKA
TUESDAY/WEDNESDAY...BUT CONFIDENCE IN BOUNDARY LOCATION THIS FAR OUT
IS NOT HIGH AND WILL MAINTAIN A DRY FORECAST...MORE IN LINE WITH
ECMWF THAN GFS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AVIATION/1013 AM UPDATE...BRYANT
SHORT TERM...SALTZMAN
LONG TERM...FAY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1013 AM CDT THU JUL 12 2012
.UPDATE...MORNING UPPER AIR ANALYSIS INDICATES RIDGING OVER
THE SOUTHWESTERN CONUS...WITH A WEAK TROUGH OVER THE EAST. A MID
LEVEL SHORT WAVE IS NOTED OVER SOUTH CENTRAL CANADA AND THE NORTHERN
PLAINS...AND A MID LEVEL LOW IS EVIDENT NEARING THE NORTHWESTERN
CONUS FROM THE PACIFIC. WITH THE BULK OF MID AND UPPER LEVEL JET
ENERGY RELEGATED TO CANADA...WEAK MID AND UPPER LEVEL TROPOSPHERIC
FLOW PERSISTS OVER MUCH OF THE CONUS WITH ONLY A ~60KT UPPER LEVEL
JET STREAK TO SPEAK OF OVER THE NORTHWESTERN CONUS. WATER VAPOR
IMAGERY SHOWS PLENTY OF MID LEVEL MOISTURE OVER THE SOUTHWESTERN
CONUS...AS WELL AS THE SOUTHEASTERN CONUS. SOME OF THIS INCREASED
MID LEVEL MOISTURE IS BEGINNING TO SPILL OVER THE SOUTHWESTERN
CONUS RIDGE INTO THE CENTRAL PLAINS. AT THE SURFACE A RIDGE OF
HIGH PRESSURE IS NOTED OVER THE MISSISSIPPI VALLEY...WITH LOW
LEVEL RETURN FLOW TRYING TO ESTABLISH ITSELF ACROSS THE CENTRAL
PLAINS. A SURFACE TROUGH IS ALSO NOTED EXTENDING FROM THE DAKOTAS
INTO WESTERN NEBRASKA.
OVERALL TODAYS FORECAST REMAINS IN GREAT SHAPE. THE ONLY
SIGNIFICANT CHANGE AT THIS TIME WAS TO ADD SLIGHT CHANCE POPS
ACROSS OUR EXTREME NORTHWEST 21Z-00Z THIS AFTERNOON/EVENING.
CONSENSUS FROM OVERNIGHT GUIDANCE SUGGESTED ISOLATED CONVECTION
ACROSS OUR EXTREME NORTHWEST...WITH THE 12Z NAM AND HRRR REMAINING
CONSISTENT IN SUGGESTING THE SAME.
INTERESTING TO NOTE SURFACE DEW POINTS ACROSS THE EASTERN HALF OF
OUR CWA ARE REALLY SPIKING THIS MORNING...WITH DEW POINTS FROM
KJYR TO KK61 ALREADY IN THE MID TO UPPER 60S. THAT BEING
SAID...THIS MOISTURE RETURN HAS NOT YET INFILTRATED OUR
WEST/NORTHWESTERN CWA WHERE SURFACE DEW POINTS ARE STILL IN THE MID
TO UPPER 50S FROM KODX TO KLXN. SHORT TERM GUIDANCE SUGGESTS
SURFACE DEW POINTS ACROSS OUR WEST/NORTHWEST SHOULD REMAIN RELATIVELY
LOW WHEN COMPARED TO LOCATIONS FARTHER EAST...THUS RESULTING IN
RELATIVELY LOWER INSTABILITY VALUES. 12Z NAM SUGGESTS 0-1KM MLCAPE
VALUES WILL ONLY APPROACH 1000J/KG ACROSS OUR WEST/NORTHWEST THIS
AFTERNOON...WITH HIGHER VALUES FARTHER EAST. THE AFOREMENTIONED
WEAK MID TO UPPER LEVEL TROPOSPHERIC FLOW IS ALSO HELPING PROMOTE
WEAK DEEP LAYER BULK SHEAR VALUES...WITH THESE VALUES EXPECTED TO
REMAIN IN THE 20-30KT RANGE THIS AFTERNOON. GIVEN ALL
THIS...CONTINUE TO FIND IT HARD TO BELIEVE WE WILL SEE MUCH IN THE
WAY OF SEVERE WEATHER SHOULD DEEP CONVECTION BE REALIZED ACROSS
OUR NORTHWEST LATE THIS AFTERNOON/EVENING...BUT WHAT INSTABILITY
AND SHEAR ARE AVAILABLE MAY BE ENOUGH TO PROMOTE AN ISOLATED
STRONG STORM AND WILL CONTINUE SUCH WORDING IN THE HWO.
&&
.PREV DISCUSSION... /ISSUED 626 AM CDT THU JUL 12 2012/
AVIATION...12Z TAF. VFR CONDITIONS ARE EXPECTED THROUGH THE TAF
PERIOD. A SURFACE COOL FRONT WILL EDGE INTO WESTERN AND NORTHERLY
NEBRASKA THIS AFTERNOON AND TONIGHT. SHOWERS AND THUNDERSTORMS ARE
POSSIBLE MAINLY NORTH OF KGRI LATE THIS EVENING INTO TONIGHT...BUT
DUE TO THE ISOLATED OR SCATTERED NATURE OF ACTIVITY DID NOT
INCLUDE IN TAF JUST YET. WINDS WILL BE FAIRLY LIGHT AND VARIABLE
BUT WILL FAVOR A SOUTHERLY DIRECTION FOR MUCH OF THE DAY.
PREV DISCUSSION... /ISSUED 357 AM CDT THU JUL 12 2012/
SHORT TERM...TODAY THROUGH SATURDAY NIGHT.
A QUICK OVERNIGHT UPPER LEVEL ANALYSIS REVEALS A DEEPENING TROUGH
ACROSS THE SOUTHERN MISSISSIPPI RIVER VALLEY WHILE AN UPPER LEVEL
RIDGE CONTINUES TO LINGER ACROSS THE SOUTHWEST. A FEW UPPER LEVEL
TROUGHS CONTINUE TO TRAVERSE THE NORTHERN HALF OF THE UNITED STATES
POSITIONED ACROSS THE WEST COAST...DAKOTAS AND FURTHER NORTHEAST
ACROSS QUEBEC. AT THE SURFACE LOW PRESSURE ALSO CONTINUES TO SLIDE
EASTWARD ACROSS THE DAKOTAS WITH A LINGERING SURFACE TROUGH ACROSS
THE FRONT RANGE OF THE ROCKIES.
THE MAIN CONCERN FOR THE SHORT TERM PERIOD WILL FOCUS ON
PRECIPITATION CHANCES ACROSS THE AREA. BEGINNING THURSDAY AFTERNOON
AND OVERNIGHT...THE UPPER LEVEL TROUGH ACROSS THE DAKOTAS WILL SLIDE EAST
SOUTHEAST ALONG THE PERIPHERY OF THE UPPER LEVEL RIDGE. THIS IN
COMBINATION WITH THE SURFACE TROUGH PUSHING SOUTHEAST ACROSS THE
AREA WILL LIKELY GENERATE AT LEAST SOME CHANCES FOR SHOWERS AND
THUNDERSTORMS ACROSS PORTIONS OF NEBRASKA. BEST CHANCES REMAIN
ACROSS THE NORTH AND EAST PORTIONS OF THE FORECAST AREA...AS UPPER
LEVEL FORCING WILL LIKELY REMAIN FAR ENOUGH TO THE NORTH AND EAST TO
REALLY IMPACT A GOOD PORTION OF THE AREA.
CONTINUING INTO FRIDAY...MODELS CONTINUE TO LINGER THE SURFACE
BOUNDARY MAINLY JUST NORTH OF THE NEBRASKA KANSAS BORDER...WHILE THE
UPPER LEVEL TROUGH DEEPENS ACROSS MINNESOTA...IOWA...AND MISSOURI.
CONTINUED PRECIPITATION CHANCES THROUGH THE FRIDAY AND FRIDAY NIGHT
TIME FRAME...WITH THE BOUNDARY ACROSS THE AREA...AND WEAK UPPER
LEVEL WAVES SHIFTING THROUGH THE REGION. WHILE NOT EXACTLY THE BEST
SETUP...THERE COULD BE A FEW SHOWERS ESPECIALLY ACROSS THE EASTERN
PORTION OF THE FORECAST AREA THROUGH THE FRIDAY INTO FRIDAY NIGHT
TIME FRAME. CERTAINLY NOT EXPECTING A WASH OUT AT THIS TIME.
CONCERNING SEVERE WEATHER CHANCES...BOTH THIS AFTERNOON AND
FRIDAY...SHEAR WILL BE THE LIMITING FACTOR. AT LEAST 1500 TO 2000
J/KG REMAINS SITUATED ACROSS PORTIONS OF THE FORECAST AREA...ACROSS
THE NORTHWEST THIS AFTERNOON AND ACROSS THE FAR EAST ON FRIDAY.
HOWEVER...IN BOTH CASES DEEP LAYER SHEAR LOOKS TO BE NEAR OR LESS
THAN 30 KTS IN BOTH CASES. GIVEN A BIT MORE INSTABILITY ON
FRIDAY...AND FOR THE SAKE OF CONTINUITY WILL CONTINUE WITH STRONG
WORDING THIS AFTERNOON AND STRONG TO SEVERE WORDING ON FRIDAY.
REGARDING TEMPERATURES...WENT AHEAD AND RAISED HIGH TEMPERATURES A
FEW DEGREES BOTH TODAY...FRIDAY AND SATURDAY. GIVEN THAT MODEL
GUIDANCE WAS HIGHER ALL THREE DAYS AND AN ONE INSTANCE WAS AS MUCH
AS 10 DEGREES HIGHER...WENT AHEAD WITH A FEW DEGREES INCREASE. CLOUD
COVER AND THE SURFACE TROUGH COULD BE A LIMITING FACTOR BUT STILL
EXPECTING TEMPERATURES IN THE LOW TO MID 90S ACROSS THE FORECAST
AREA.
LONG TERM...SUNDAY THROUGH WEDNESDAY. THE EXTENDED PERIODS WILL
SEE A RETURN OF HOT CONDITIONS AS AN UPPER RIDGE OF HIGH PRESSURE
REBUILDS ACROSS THE INTERIOR CONUS. WITH THE HOT AIRMASS SETTLING
IN...HIGH TEMPERATURES SHOULD AVERAGE IN THE 90S...WITH LOWS IN THE
70S. HAVE KEPT CONDITIONS DRY IN THIS PATTERN...BUT WILL NEED TO
MONITOR SURFACE BOUNDARY FEATURES TOWARDS THE MIDDLE WEEK OF NEXT
WEEK AS FRONT MAY TRY TO SAG SOUTH INTO CENTRAL NEBRASKA
TUESDAY/WEDNESDAY...BUT CONFIDENCE IN BOUNDARY LOCATION THIS FAR OUT
IS NOT HIGH AND WILL MAINTAIN A DRY FORECAST...MORE IN LINE WITH
ECMWF THAN GFS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
1013 AM UPDATE...BRYANT
SHORT TERM...SALTZMAN
LONG TERM...FAY
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1249 AM CDT THU JUL 12 2012
.AVIATION...
VFR IS EXPECTED MOST AREAS TONIGHT AND THURSDAY. THE DISTURBANCE
ACROSS WRN NEB TONIGHT WILL DRIFT SLOWLY EAST OVERNIGHT WITH A
SECOND WEAK DISTURBANCE MOVING THROUGH DURING THE AFTERNOON
THURSDAY. ISOLATED TO PERHAPS SCATTERED TSTM ACTIVITY IS EXPECTED AS
THESE DISTURBANCES MOVE THROUGH. OTHERWISE VFR IS EXPECTED. STORM
ACTIVITY MAY CONTINUE INTO EARLY THURSDAY EVENING.
&&
.PREV DISCUSSION... /ISSUED 854 PM CDT WED JUL 11 2012/
UPDATE...
THE SHORT WAVE DISTURBANCE ACROSS ERN WY IS MOVING EAST FASTER THAN
ANY OF THE MODELS WOULD INDICATE. ALL MODELS ARE EITHER SILENT OR
DISSIPATE THE CONVECTION BEFORE IT MOVES VERY FAR EAST INTO NEB.
THE FCST HAS BEEN UPDATED FOR ISOLATED TSTMS WITH GUSTY WINDS
ALONG AND WEST OF HIGHWAY 61.
PREV DISCUSSION... /ISSUED 254 PM CDT WED JUL 11 2012/
SYNOPSIS...WATER VAPOR IMAGERY INDICATES TWO SIGNIFICANT SHORT
WAVES MOVING AROUND THE WESTERN STATES UPPER RIDGE. THE FIRST IS
PUSHING INTO WRN ND AND THE SECOND MOVING INTO SWRN MT PER WV
IMAGERY AND RAP PVU FIELDS. AHEAD OF THESE FEATURES SCT
THUNDERSTORMS HAVE DEVELOPED IN THE HIGHER TERRAIN AND ARE PUSHING
EWD. ACROSS WESTERN AND NORTH CENTRAL NEBRASKA SKIES ARE MAINLY
CLEAR EXCEPT FOR CUMULUS FIELD DEVELOPING FROM MCK TO VTN. NORTH
CENTRAL NEBRASKA LIES IN SFC THERMAL RIDGE AHEAD OF ADVANCING COLD
FRONT PUSHING INTO THE NORTHERN HIGH PLAINS.
SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT). UPPER FEATURE
MOVING INTO SOUTHWEST MT WILL CONTINUE TO PUSH SEWD TONIGHT INTO
THURSDAY. MODELS SIMILAR IN PROGRESSION OF THIS FEATURE BUT DIFFER
IN THE HANDLING OF ASSOCIATED UPPER PV FEATURES AND RESULTING
CONVECTION AS THE SFC REFLECTION /COLD FRONT/ MOVES INTO NORTHWEST
NEBRASKA. GFS KEEPS A STRONGER UPPER PV MAX AND HENCE BETTER LARGE
SCALE FORCING FOR ASCENT ACROSS THE DAKOTAS...WHILE THE NAM HAS AN
UPPER PV MAX MOVING INTO NWRN NEBRASKA WHICH SERVES TO PROMOTE
BETTER CONVERGENCE ALONG THE FRONT IN WESTERN NEBRASKA THROUGH THE
DAY THURSDAY. WILL SIDE WITH THE NAM SOLUTION BELIEVING THE GFS
IDEA IS AT LEAST PARTIAL DRIVEN BY CONVECTIVE FEEDBACK. THIS WOULD
YIELD CHC POPS ALONG AND IN THE VCNTY OF THE FRONT AS THE FRONT
SLIDES SLOWLY SOUTH ACROSS NEBRASKA. FRONT WILL BE MEETING
RESISTANCE AS IT ENCOUNTERS DIURNAL PLAINS LLJ THRU THURS MORNING
AND PRE-EXISTING HEAT ACROSS THE CENTRAL PLAINS. TEMPERATURES
AHEAD OF THE FRONT SHOULD WARM QUICKLY THURSDAY WITH PLENTY OF
SUNSHINE....SO LOW TO MID 90S IN THE SOUTH STILL LOOKS PLAUSIBLE.
CONVECTION SHOULD BE LIMITED PRIMARILY TO THE FORCING ALONG THE
FRONT BUT AS LOW LEVEL MOISTURE POOLS AHEAD OF IT THE INSTABILITY
SHOULD INCREASE THROUGH THE AFTERNOON. HOWEVER...FCST SOUNDINGS
SUGGEST CAPE DISTRIBUTION IS IN A NARROW CORRIDOR VERTICALLY SO
WITH MARGINAL DEEP LAYER SHEAR WOULD EXPECT UPDRAFTS WILL BE PULSE
TYPE EXCEPT WHERE ORGANIZATION CAN BE SUSTAINED...SUCH AS CLOSE TO
THE FRONT AND WHERE STORM-SCALE INTERACTIONS DICTATE. RESULT
SHOULD BE LIMITED LARGE HAIL THREAT BUT SOME POTENTIAL FOR NEAR SVR
WIND GUSTS.
EXTENDED...FRIDAY THROUGH NEXT WEDNESDAY...
ON FRIDAY...AN UPPER LEVEL WAVE WILL BE EXITING THE REGION WITH
NORTHWEST FLOW ALOFT EXPECTED ACROSS THE REGION IN ITS WAKE. A WEAK
COLD FRONT WILL PUSH INTO NEBRASKA FROM THE NORTH ON FRIDAY
MORNING...BUT HAVE A HARD TIME MAKING IT TOO FAR INTO THE STATE.
BEHIND THE DEPARTING UPPER WAVE...AN UPPER LEVEL RIDGE WILL BUILD IN
OVER THE CENTRAL U.S. ALLOWING ABOVE AVERAGE TEMPERATURES TO
CONTINUE ACROSS THE AREA FOR SATURDAY. THE UPPER LEVEL RIDGE AXIS
WILL DRIFT EAST OVER THE WEEKEND...WITH AN UPPER LEVEL DISTURBANCE
FOLLOWING RIGHT BEHIND IT IN SOUTHWEST FLOW ALOFT. THE ECMWF AND GFS
MODELS ARE IN GOOD AGREEMENT REGARDING THIS WAVE...WHICH MAY PROVIDE
SOME PRECIPITATION CHANCES ACROSS THE NORTHWEST FORECAST AREA
SATURDAY NIGHT. HAVE NUDGED TEMPERATURES UP FOR FRIDAY AND
SATURDAY...CLOSER TO THE WARMER ECMWF/GEM/FIM MODELS...AND MANY OF
THE BIAS CORRECTED GRID VALUES.
TEMPERATURES ARE EXPECTED TO REMAIN ABOVE AVERAGE FOR THE BEGINNING
OF NEXT WEEK AS SOUTHWEST FLOW ALOFT WILL KEEP WARM SOUTHERLY FLOW
IN THE LOW LEVELS. MODELS HINT AT AN UPPER WAVE MOVING EAST ACROSS
THE CANADIAN BORDER TOWARD MID WEEK...POSSIBLY USHERING IN A COLD
FRONT ACROSS THE NORTHERN PLAINS STATES.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/EXTENDED...JWS
AVIATION...POWER
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1116 PM CDT WED JUL 11 2012
.UPDATE...
.AVIATION...
DISTURBANCE ACROSS WRN NEB TONIGHT WILL DRIFT SLOWLY EAST
OVERNIGHT WITH A SECOND WEAK DISTURBANCE MOVING THROUGH DURING THE
AFTERNOON THURSDAY. ISOLATED TO PERHAPS SCATTERED TSTM ACTIVITY IS
EXPECTED AS THESE DISTURBANCES MOVE THROUGH. OTHERWISE VFR IS EXPECTED.
&&
.PREV DISCUSSION... /ISSUED 854 PM CDT WED JUL 11 2012/
UPDATE...
THE SHORT WAVE DISTURBANCE ACROSS ERN WY IS MOVING EAST FASTER THAN
ANY OF THE MODELS WOULD INDICATE. ALL MODELS ARE EITHER SILENT OR
DISSIPATE THE CONVECTION BEFORE IT MOVES VERY FAR EAST INTO NEB.
THE FCST HAS BEEN UPDATED FOR ISOLATED TSTMS WITH GUSTY WINDS
ALONG AND WEST OF HIGHWAY 61.
PREV DISCUSSION... /ISSUED 618 PM CDT WED JUL 11 2012/
UPDATE...
AVIATION...
VFR IS EXPECTED MOST AREAS TONIGHT AND FRIDAY. A WEAK UPPER LEVEL
DISTURBANCE ACROSS WY/SCNTL MT THIS EVENING WILL MOVE EAST TONIGHT AND
THEN SOUTHEAST THROUGH THE FCST AREA FRIDAY MORNING. THE
DISTURBANCE MAY PRODUCE ISOLATED SHRA/TSTMS. OTHERWISE VFR ALL AREAS.
PREV DISCUSSION... /ISSUED 254 PM CDT WED JUL 11 2012/
SYNOPSIS...WATER VAPOR IMAGERY INDICATES TWO SIGNIFICANT SHORT
WAVES MOVING AROUND THE WESTERN STATES UPPER RIDGE. THE FIRST IS
PUSHING INTO WRN ND AND THE SECOND MOVING INTO SWRN MT PER WV
IMAGERY AND RAP PVU FIELDS. AHEAD OF THESE FEATURES SCT
THUNDERSTORMS HAVE DEVELOPED IN THE HIGHER TERRAIN AND ARE PUSHING
EWD. ACROSS WESTERN AND NORTH CENTRAL NEBRASKA SKIES ARE MAINLY
CLEAR EXCEPT FOR CUMULUS FIELD DEVELOPING FROM MCK TO VTN. NORTH
CENTRAL NEBRASKA LIES IN SFC THERMAL RIDGE AHEAD OF ADVANCING COLD
FRONT PUSHING INTO THE NORTHERN HIGH PLAINS.
SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT). UPPER FEATURE
MOVING INTO SOUTHWEST MT WILL CONTINUE TO PUSH SEWD TONIGHT INTO
THURSDAY. MODELS SIMILAR IN PROGRESSION OF THIS FEATURE BUT DIFFER
IN THE HANDLING OF ASSOCIATED UPPER PV FEATURES AND RESULTING
CONVECTION AS THE SFC REFLECTION /COLD FRONT/ MOVES INTO NORTHWEST
NEBRASKA. GFS KEEPS A STRONGER UPPER PV MAX AND HENCE BETTER LARGE
SCALE FORCING FOR ASCENT ACROSS THE DAKOTAS...WHILE THE NAM HAS AN
UPPER PV MAX MOVING INTO NWRN NEBRASKA WHICH SERVES TO PROMOTE
BETTER CONVERGENCE ALONG THE FRONT IN WESTERN NEBRASKA THROUGH THE
DAY THURSDAY. WILL SIDE WITH THE NAM SOLUTION BELIEVING THE GFS
IDEA IS AT LEAST PARTIAL DRIVEN BY CONVECTIVE FEEDBACK. THIS WOULD
YIELD CHC POPS ALONG AND IN THE VCNTY OF THE FRONT AS THE FRONT
SLIDES SLOWLY SOUTH ACROSS NEBRASKA. FRONT WILL BE MEETING
RESISTENCE AS IT ENCOUNTERS DIURNAL PLAINS LLJ THRU THURS MORNING
AND PRE-EXISTING HEAT ACROSS THE CENTRAL PLAINS. TEMPERATURES
AHEAD OF THE FRONT SHOULD WARM QUICKLY THURSDAY WITH PLENTY OF
SUNSHINE....SO LOW TO MID 90S IN THE SOUTH STILL LOOKS PLAUSIBLE.
CONVECTION SHOULD BE LIMITED PRIMARILY TO THE FORCING ALONG THE
FRONT BUT AS LOW LEVEL MOISTURE POOLS AHEAD OF IT THE INSTABILITY
SHOULD INCREASE THROUGH THE AFTERNOON. HOWEVER...FCST SOUNDINGS
SUGGEST CAPE DISTRIBUTION IS IN A NARROW CORRIDOR VERTICALLY SO
WITH MARGINAL DEEP LAYER SHEAR WOULD EXPECT UPDRAFTS WILL BE PULSE
TYPE EXCEPT WHERE ORGANIZATION CAN BE SUSTAINED...SUCH AS CLOSE TO
THE FRONT AND WHERE STORM-SCALE INTERACTIONS DICTATE. RESULT
SHOULD BE LIMTED LARGE HAIL THREAT BUT SOME POTENTIAL FOR NEAR SVR
WIND GUSTS.
EXTENDED...FRIDAY THROUGH NEXT WEDNESDAY...
ON FRIDAY...AN UPPER LEVEL WAVE WILL BE EXITING THE REGION WITH
NORTHWEST FLOW ALOFT EXPECTED ACROSS THE REGION IN ITS WAKE. A WEAK
COLD FRONT WILL PUSH INTO NEBRASKA FROM THE NORTH ON FRIDAY
MORNING...BUT HAVE A HARD TIME MAKING IT TOO FAR INTO THE STATE.
BEHIND THE DEPARTING UPPER WAVE...AN UPPER LEVEL RIDGE WILL BUILD IN
OVER THE CENTRAL U.S. ALLOWING ABOVE AVERAGE TEMPERATURES TO
CONTINUE ACROSS THE AREA FOR SATURDAY. THE UPPER LEVEL RIDGE AXIS
WILL DRIFT EAST OVER THE WEEKEND...WITH AN UPPER LEVEL DISTURBANCE
FOLLOWING RIGHT BEHIND IT IN SOUTHWEST FLOW ALOFT. THE ECMWF AND GFS
MODELS ARE IN GOOD AGREEMENT REGARDING THIS WAVE...WHICH MAY PROVIDE
SOME PRECIPITATION CHANCES ACROSS THE NORTHWEST FORECAST AREA
SATURDAY NIGHT. HAVE NUDGED TEMPERATURES UP FOR FRIDAY AND
SATURDAY...CLOSER TO THE WARMER ECMWF/GEM/FIM MODELS...AND MANY OF
THE BIAS CORRECTED GRID VALUES.
TEMPERATURES ARE EXPECTED TO REMAIN ABOVE AVERAGE FOR THE BEGINNING
OF NEXT WEEK AS SOUTHWEST FLOW ALOFT WILL KEEP WARM SOUTHERLY FLOW
IN THE LOW LEVELS. MODELS HINT AT AN UPPER WAVE MOVING EAST ACROSS
THE CANADIAN BORDER TOWARD MID WEEK...POSSIBLY USHERING IN A COLD
FRONT ACROSS THE NORTHERN PLAINS STATES.
AVIATION...18Z TAF FOR KLBF AND KVTN.
VFR CIGS/VSBY THROUGH THE PERIOD. WILL LIKELY SEE SOME HIGH BASED
CU THIS AFTERNOON ESPECIALLY ACROSS NORTH CENTRAL NEBRASKA FROM
KVTN-KLBF BUT SHOULDNT GET BEYOND SCT. OTHERWISE COLD FRONT WILL
APPROACH THE AREA LATE IN THE PERIOD BUT PASSAGE EXPECTED AFTER
18Z...WHEN ISOLD TO SCT TSRA WOULD BE POSSIBLE NEAR KVTN...BUT
AGAIN AFTER 12/18Z.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/EXTENDED...JACOBS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
749 PM PDT FRI JUL 13 2012
.SYNOPSIS...AN UPPER LEVEL DISTURBANCE COMBINED WITH ABUNDANT
MOISTURE IN THE ATMOSPHERE WILL RESULT IN NUMEROUS SHOWERS AND
THUNDERSTORMS THROUGH SATURDAY. SOME OF THE STORMS WILL PRODUCE
LOCALLY HEAVY DOWNPOURS WHICH COULD RESULT IN FLASH FLOODING. THIS
DISTURBANCE IS EXPECTED TO MOVE TO THE NORTHEAST BY SATURDAY
NIGHT...HOWEVER LINGERING MOISTURE WILL STILL EXIST ACROSS THE AREA
RESULTING IN THE CHANCE FOR SHOWERS AND THUNDERSTORMS IN MOST AREAS
AGAIN ON SUNDAY. BY MONDAY INTO TUESDAY DRIER AIR WILL GRADUALLY
SPREAD EAST ACROSS THE AREA AS A TROUGH MOVES THROUGH THE
REGION...GRADUALLY REDUCING THE CHANCES FOR THUNDERSTORMS. DRY
CONDITIONS ARE EXPECTED JUST ABOUT AREAWIDE BY WEDNESDAY.
&&
.UPDATE...BASED ON RADAR TRENDS I MADE SOME ADJUSTMENTS TO POPS
FOR TONIGHT. THE BIGGEST CHANGES WERE ACROSS NORTHWEST SAN
BERNARDINO COUNTY WHERE IT APPEARS CONVECTION HAS LITTLE CHANCE OF
REALLY GETTING GOING BEFORE MIDNIGHT AND THE FLASH FLOOD WATCH
HERE WAS CANCELLED. IN AND AROUND LAS VEGAS...I ALSO LOWERED POPS
FOR EARLY TONIGHT - BEFORE MIDNIGHT - AS RADAR WAS RELATIVELY
QUIET AND TRENDS SUGGEST LITTLE SIGNIFICANT DEVELOPMENT TAKING
PLACE. THE LATEST NMM AND HRRR MODELS SHOW THAT ACTIVITY ON THE
BACK SIDE OF THE ELONGATED VORTICITY FEATURE ACROSS INYO COUNTY
SHOULD SLIDE SOUTHEAST TONIGHT. THE NMM WEAKENS MOST OF THIS
BEFORE IT EXITS THE SOUTH END OF DEATH VALLEY NATIONAL PARK AND
CENTRAL NYE COUNTY WHILE THE HRRR SUGGESTS THIS AREA MAY GET GOING
AND ARRIVE IN LAS VEGAS LATE TONIGHT. BASED ON THE LACK OF
IMPRESSIVE RETURNS ON RADAR IN THIS AREA PRESENTLY I HAVE HARD
TIME BUYING THE HRRR SOLUTION WITH RESPECT TO THE NORTHERN BATCH
OF CONVECTION. OVER THE SOUTHEAST CWFA THIS SHOULD REMAIN THE MOST
ACTIVE PART OF THE AREA THROUGH MIDNIGHT AND NO CHANGES WERE MADE.
SIGNIFICANT FLASH FLOODING WAS REPORTED IN LAKE HAVASU CITY THIS
EVENING AND MORE DETAIL REPORTS WILL BE FORTHCOMING AS WE GET
THEM. SATELLITE IMAGERY...RADAR AND THE HRRR MODEL ALL SUGGEST THE
FOCUS WITHIN THE NEXT 2-4 HOURS WILL BE OVER THE SOUTHERN HALF OF
MOHAVE COUNTY AND FAR SOUTHEAST SAN BERNARDINO COUNTY. THE PRIMARY
HAZARD HERE WILL CONTINUE TO BE FLASH FLOODING. THE 00Z SOUNDING
FROM OUR OFFICE SHOWED A PWAT OF 1.60 INCHES SO THE HEAVIEST THUNDERSTORMS
COULD CERTAINLY DUMP OVER TWO INCHES OF RAIN ESPECIALLY IF THEY
MOVE SLOW ENOUGH.
&&
.AVIATION...FOR MCCARRAN...
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...FOR MCCARRAN...THE MAIN ISSUE TONIGHT WILL BE WHEN ANY TSRA
WILL MOVE BACK INTO THE VALLEY. WHILE SHRA/TSRA ARE POSSIBLE LATER
TONIGHT CONFIDENCE IN TIMING IS REDUCED HOWEVER IT LOOKS LIKE
THROUGH AT LEAST 06Z IT SHOULD STAY DRY IN THE VALLEY FOR THE MOST
PART. ADDITIONAL SHRA/TSRA WILL BE POSSIBLE AGAIN ON SATURDAY
ESPECIALLY AFTER 18Z. GUSTY AND ERRATIC WINDS AND REDUCED
CIGS/VSBY WILL BE THE MAIN HAZARD WITH ANY TSRA AND OUTFLOW
BOUNDARIES. OTHERWISE WINDS WILL MAINLY BE UNDER 10 KTS. SCT-BKN
CLOUDS MAINLY AOA 8K- 12K FEET AWAY FROM TSRA.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SCT SHRA/TSRA WILL CONTINUE THROUGH TONIGHT THOUGH THE
COVERAGE OF ACTIVITY SHOULD DECREASE BETWEEN 05Z AND 07Z SUNDAY.
ADDITIONAL SHRA AND TSRA WILL BE POSSIBLE AGAIN ON SATURDAY. GUSTY
AND ERRATIC WINDS AND REDUCED CIGS/VSBY POSSIBLE IN AND NEAR ANY
STORMS. AWAY FROM SHRA/TSRA WINDS SHOULD FAVOR DIURNAL DIRECTIONAL
TRENDS. SCT-BKN CLOUDS AOA 8K-12K FEET AWAY FROM TSRA.
&&
.PREVIOUS DISCUSSION...
ISSUED 321 PM PDT FRI JUL 13 2012
.SHORT TERM...THE DISTURBANCE ALOFT OVER SOCAL CONTINUES TO BECOME
STRETCHED OUT ON WATER VAPOR IMAGERY AND TAKING ON MORE OF AN
ELONGATED LOOK TO IT AS IT HEADS NORTHEAST. MODEL 500 MB PROGS
SHOWED THIS IN THEIR VORTICITY AND HEIGHT FIELDS QUITE NICELY ON THE
12Z RUNS AND OVERALL WITH RESPECT TO GENERAL SYNOPTIC SET-UP THINGS
LOOK ON TRACK. THIS DISTURBANCE SHOULD HEAD TOWARDS THE MOJAVE
NATIONAL PRESERVE THIS EVENING AND THEN TOWARDS SOUTHEASTERN NEVADA
(LINCOLN AND CLARK COUNTIES) BY SATURDAY BEFORE MOVING INTO SOUTHERN
UTAH BY SATURDAY EVENING.
ABUNDANT MOISTURE (PWAT WAS 1.46 INCH ON THE 12Z SOUNDING FROM OUR
OFFICE AND 1.44 INCH ON A 13Z SOUNDING FROM EDWARDS AFB) LIES IN
PLACE SO THIS FEATURE WILL CERTAINLY HAVE THAT TO WORK WITH. THE 12Z
GFS SHOWS A 50 KT+ JET STREAK AT 250 MB SHOULD MOVE ACROSS THE LOWER
DESERTS OF SOCAL THIS EVENING TOWARDS NORTHWEST ARIZONA ON THE
SOUTHERN EDGE OF THE DISTURBANCE WHICH SHOULD HELP TO ENHANCE LIFT
ACROSS THE AREA THIS EVENING. OVER THE SOUTHERN GREAT BASIN THE
BROAD AREA OF CLOUDS AND SHOWERS/ISOLATED THUNDERSTORMS SHOULD
CONTINUE TO MOVE NORTH THIS EVENING AND OVERALL EXPECT THE MAIN
ISSUE IN THIS AREA TO BE LOCALLY HEAVY DOWNPOURS THAT COULD TRIGGER
FLASH FLOODING. FURTHER SOUTH THINGS COULD BE MORE INTERESTING THIS
EVENING AS A DRY PUNCH OF AIR HAS PUSHED NORTH ACROSS THE MOJAVE
DESERT AND ALLOWED FOR SOME CLEARING AND GIVEN THE ATMOSPHERE A
BETTER CHANCE TO DESTABILIZE. AS A RESULT...THIS WILL BE THE AREA TO
WATCH FOR MORE INTENSE CONVECTIVE DEVELOPMENT THIS EVENING. STORMS
IN THIS AREA MAY HAVE A BETTER SHOT TO BECOME SEVERE...WITH THE
PRIMARY HAZARD BEING GUSTY WINDS. HAIL IS POSSIBLE...THOUGH MOST
LIKELY WOULD BE SMALL...WITH FREEZING LEVELS AROUND 15000 FEET. THE
WRF AND LOCAL NMM MODELS BOTH HAVE INDICATED THAT CONVECTION SHOULD
DEVELOP OVER THE SAN BERNARDINO COUNTY DESERTS THIS EVENING...THEN
MOVE NORTHWARD TOWARDS SOUTHERN NEVADA AND SOUTHEAST INYO COUNTY.
POPS THIS EVENING WERE BASED ON A BLEND OF THE WRF AND NMM AND RADAR
TRENDS. THE FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH MIDNIGHT AS
THE PRIMARY HAZARD WILL BE FLASH FLOODING DUE TO THE ABUNDANT
MOISTURE IN PLACE AND THE HIGH UNLOAD POTENTIAL IN ANY STRONGER
STORMS FOR HEAVY RAIN. ACTIVITY SHOULD WIND DOWN IN MOST AREAS BY
MIDNIGHT...BUT LINCOLN COUNTY COULD STAY QUITE ACTIVE AS EVERYTHING
THAT DEVELOPS FURTHER SOUTH THIS EVENING HEADS IN THAT GENERAL
DIRECTION. LOWS TONIGHT AGAIN WILL BE TRICKY AND BLENDED CONTINUITY
WITH THE BETTER PERFORMING GUIDANCE.
ALTHOUGH WE SHOULD SEE A DOWNWARD TREND IN CONVECTION OVERNIGHT THE
FLASH FLOOD WATCH WAS EXTENDED FOR MOST AREAS THROUGH SATURDAY
EVENING EXCEPT FOR NW SAN BERNARDINO COUNTY...THE MORONGO AND CADIZ
BASINS. ABUNDANT MOISTURE IS SHOWN TO REMAIN IN PLACE ON SATURDAY
WITH PWATS OF 1.25 INCHES OR GREATER AND 850 MB DEWPOINTS OF 12C+
OVER THE EASTERN CWFA AND ONCE AGAIN THE UNLOAD POTENTIAL WILL BE
THERE IN ANY THUNDERSTORMS THAT REALLY GET GOING. IN ADDITION THE
PRESENCE OF THE MID-LEVEL VORTICITY FEATURE OVER LINCOLN/CLARK
COUNTIES SHOULD HELP TO ENHANCE CONVECTION IN THESE AREAS. FURTHER
WEST DRIER AND MORE STABLE AIR WILL START TO WORK IN FROM THE
PACIFIC AHEAD OF A MID/UPPER LEVEL TROUGH DIGGING SOUTH. I DID TRIM
POPS BACK A LITTLE ESPECIALLY WEST OF BARSTOW. AS LONG AS WE CLEAR
OUT TOMORROW MORNING...WE SHOULD HAVE A GOOD START TO GET CONVECTION
GOING AND I DID ADJUST UP POPS SLIGHTLY IN THESE AREAS. GUSTY WINDS
WILL ONCE AGAIN BE A THREAT WITH ANY STRONGER STORMS. TEMPS TOMORROW
SHOULD TREND UP WHERE WE GET MORE SUN BUT IN MANY AREAS FURTHER EAST
WILL ONCE AGAIN BE 10 OR MORE DEGREES BELOW NORMAL. A BLEND OF THE
MET AND MAV WERE USED FOR HIGH TEMPS SATURDAY. MOST AREAS SHOULD SEE
CONVECTION WIND DOWN SATURDAY EVENING.
.LONG TERM...THE AFOREMENTIONED DISTURBANCE GETS KICKED ACROSS UTAH
ON SUNDAY AS THE MID/UPPER LEVEL TROUGH OFFSHORE DIGS SOUTH INTO
CALIFORNIA. OPERATIONAL MODELS NOW SHOW ANOTHER PIECE OF ENERGY
ROTATING THROUGH THE BASE OF THE TROUGH THEN TOWARDS SOCAL. WITH
MOISTURE STILL LINGERING ACROSS OUR AREA AND THIS ENERGY ADDITIONAL
SHOWERS/THUNDERSTORMS WILL BE POSSIBLE ON SUNDAY ESPECIALLY IN THE
AFTERNOON AND EVENING. OVER THE FAR SOUTHWEST CWFA DRIER AND STABLE
AIR IS SHOWN TO BE MORE FIRMLY IN PLACE AND THESE AREAS SHOULD STAY
FREE OF CONVECTION. POPS WERE INCREASED SUNDAY OVER THE NORTHWEST
CWFA AS THE WRF ESPECIALLY DEVELOPS CONVECTION OVER THESE AREAS IN
THE AFTERNOON. ADDITIONAL PIECES OF ENERGY ARE FORECAST TO ROTATE
THROUGH THE BASE OF THE TROUGH ON MONDAY INTO TUESDAY AS THE TROUGH
MOVES EAST AND ACROSS CALIFORNIA. ALTHOUGH THIS WILL GRADUALLY
RESULT IN DRIER AIR SPREADING IN FROM THE WEST LINGERING MOISTURE
AND INSTABILITY IN THE EAST WILL STILL SUPPORT KEEPING IN
THUNDERSTORM CHANCES ON MONDAY WITH MUCH LESS OF A CHANCE ON
TUESDAY. AGAIN THE MOIST-DRY BOUNDARY MAY SERVE AS A FOCUSING AREA
FOR THUNDERSTORM DEVELOPMENT. I ADJUSTED DOWN MAX TEMPS TOWARDS A
BLEND OF THE MEX AND ECMWF MOS AS BIAS CORRECTED NUMBERS LOOKED
CONTAMINATED BY RECENT TRENDS.
BY WEDNESDAY THE TROUGH OFFSHORE LIFTS NORTH IN RESPONSE TO A
BUILDING RIDGE ALOFT OVER THE SOUTHERN CONUS THAT EDGES WEST INTO
ARIZONA. THIS SHOULD ALLOW FOR A WARMING TREND WITH HIGH TEMPS
TRENDING BACK CLOSER TO NORMAL. BY THURSDAY THE FLOW ALOFT MAY TURN
SOUTHERLY ENOUGH TO ALLOW SOME MOISTURE TO SNEAK BACK IN. THUS WE
LEFT IN SOME HIGH GHOST POPS TO LOW END SLIGHT CHANCE POPS FOR
THURSDAY. BY FRIDAY THESE WERE INCREASED TO MORE OF A BROADBRUSHED
SLIGHT CHANCE OF THUNDERSTORMS IN MOST AREAS...ESPECIALLY THE HIGHER
ELEVATIONS. EVEN WITH THE INCREASED CLOUDS AROUND...TEMPS SHOULD BE
NEAR NORMAL GIVEN THE HIGHER HEIGHTS PROGGED TO BE IN PLACE THEN.
&&
.FIRE WEATHER...WET STORMS ARE EXPECTED THIS EVENING AND AGAIN ON
SATURDAY SO NO HEADLINES APPEAR NEEDED AT THIS TIME. GUSTY WINDS IN
AND NEAR STORMS WILL BE A HAZARD NEAR ANY CURRENT FIRES ALREADY
GOING.
&&
&&
.VEF WATCHES/WARNINGS/ADVISORIES...
NV...FLASH FLOOD WATCH THROUGH SATURDAY EVENING FOR NVZ015>022.
AZ...FLASH FLOOD WATCH THROUGH SATURDAY EVENING FOR AZZ001>003-036.
CA...FLASH FLOOD WATCH THROUGH SATURDAY EVENING FOR CAZ522-524-527.
FLASH FLOOD WATCH UNTIL MIDNIGHT PDT TONIGHT FOR CAZ525-526.
&&
$$
STACHELSKI/99
HTTP://WEATHER.GOV/LASVEGAS
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
654 AM EDT THU JUL 12 2012
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH TOMORROW AFTERNOON. A
WEAK UPPER LEVEL DISTURBANCE FRIDAY AFTERNOON...WILL BRING A
CHANCE OF A SHOWER TO THE SOUTHERN TIER. DAYTIME HIGHS WILL BE IN
THE 80S TO NEAR 90 WITH LOWS MOSTLY IN THE UPPER 50S AND LOW 60S
FOR TODAY AND FRIDAY. OVER THE WEEKEND THERE IS A BETTER CHANCE OF
SHOWERS AND THUNDERSTORMS WITH AS MOISTURE RETURNS TO THE AREA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
4 AM DISCUSSION...HIGH PRESSURE IS STILL PROGGED BY THE MODELS TO
REMAIN IN PLACE UNTIL TOMORROW AFTERNOON. THEY SHOW 500MB HEIGHTS
BUILDING THROUGH THE DAY TODAY, WHICH WILL PLACE A FAIRLY GOOD CAP
AROUND 700MB. THIS SHOULD KEEP THE WEATHER QUIET TODAY. THERE WILL
BE MOSTLY SUNNY SKIES FOR MOST OF THE AREA. SOME AFTERNOON CUMULUS
MAY TRY TO DEVELOP OVER THE CWA. GIVEN THE CAP AND LACK OF ANY
REAL FORCING, HAVE TAKEN POPS OUT OF THE FORECAST FOR NOW.
HOWEVER, THE HRRR IS TRYING TO DEVELOP A FEW ISOLD SHOWERS ACROSS
THE AREA AFTER 17Z. THINKING IT MAY BE OVER AMPLIFYING THE
AFTERNOON CU.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
MODELS SHOWING THE UPPER LEVEL RIDGE BUILDING TO AROUND 590
DECAMETERS ON FRIDAY. HOWEVER, BY LATER FRIDAY AFTERNOON, THEY A
SHOWING A SHORTWAVE RIDING AROUND A THE RIDGE, WHICH MAY PRODUCE ENOUGH
FORCING, WHEN COMBINED WITH DAYTIME HEATING, TO ALLOW A FEW
SHOWERS TO DEVELOP IN THE WESTERN ZONES.
BY SATURDAY MORNING, MOISTURE RIDING AROUND A BERMUDA HIGH, WILL MOVE
IN FROM THE SOUTHWEST. THIS WILL POSSIBLY ALLOW SOME CONVECTIVE
CELLS TO FIRE UP LATE SATURDAY MORNING THROUGH SUNDAY MORNING. THERE
WILL BE A CONTINUOUS FLOW OF EMBEDDED SHORT WAVES RIDDING AROUND
THE RIDGE. HAVE SLOWLY INCREASED POPS THROUGH THE WEEKEND AS MORE
MOISTURE FEEDS INTO THE AREA.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
THE EXTENDED PERIOD WILL REMAIN WARM AND HUMID WITH A SOUTHWEST
FLOW ACROSS THE REGION DUE TO RETURN FLOW FROM HIGH PRESSURE
OFF THE MID ATLANTIC COAST. ALOFT A FLAT RIDGE WILL REMAIN OVER
THE NORTHEAST. DUE TO A RATHER MOIST AIR MASS ACROSS THE AREA WILL
CONTINUE WITH CHC POPS FOR PRIMARILY DIURNAL CONVECTION. LATEST
GFS/ECMWF INDICATE A SFC COLD FRONT WILL CROSS THE AREA ON
WEDNESDAY, FOLLOWED BY COOLER AND DRIER AIR FOR LATE WEEK.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
HIGH PRESSURE OVER THE REGION WILL PROVIDE VFR CONDITIONS THROUGH
THIS TAF PERIOD. AT KELM, THERE IS THE POTENTIAL FOR MVFR CONDITIONS
AGAIN TONIGHT BETWEEN 09Z-12Z DUE TO BR. EXPECT FEW/SCT ALTO CU
AROUND 6-8K FT THROUGH THE PERIOD.
LIGHT AND VARIABLE WINDS BECOMING W/SW THIS AFTERNOON AROUND 5
KNOTS THEN LIGHT AGAIN OVERNIGHT.
OUTLOOK...
FRI...VFR.
SAT/SUN/MON...GENERALLY VFR. CHC FOR SCT MVFR IN
SHWRS/TSTMS...MAINLY IN THE AFTN/EVNG.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...SLI
NEAR TERM...SLI
SHORT TERM...SLI
LONG TERM...RRM
AVIATION...RRM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
414 AM EDT THU JUL 12 2012
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH TOMORROW AFTERNOON. A
WEAK UPPER LEVEL DISTURBANCE FRIDAY AFTERNOON...WILL BRING A
CHANCE OF A SHOWER TO THE SOUTHERN TIER. DAYTIME HIGHS WILL BE IN
THE 80S TO NEAR 90 WITH LOWS MOSTLY IN THE UPPER 50S AND LOW 60S
FOR TODAY AND FRIDAY. OVER THE WEEKEND THERE IS A BETTER CHANCE OF
SHOWERS AND THUNDERSTORMS WITH AS MOISTURE RETURNS TO THE AREA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
4 AM DISCUSSION...HIGH PRESSURE IS STILL PROGGED BY THE MODELS TO
REMAIN IN PLACE UNTIL TOMORROW AFTERNOON. THEY SHOW 500MB HEIGHTS
BUILDING THROUGH THE DAY TODAY, WHICH WILL PLACE A FAIRLY GOOD CAP
AROUND 700MB. THIS SHOULD KEEP THE WEATHER QUIET TODAY. THERE WILL
BE MOSTLY SUNNY SKIES FOR MOST OF THE AREA. SOME AFTERNOON CUMULUS
MAY TRY TO DEVELOP OVER THE CWA. GIVEN THE CAP AND LACK OF ANY
REAL FORCING, HAVE TAKEN POPS OUT OF THE FORECAST FOR NOW.
HOWEVER, THE HRRR IS TRYING TO DEVELOP A FEW ISOLD SHOWERS ACROSS
THE AREA AFTER 17Z. THINKING IT MAY BE OVER AMPLIFYING THE
AFTERNOON CU.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
MODELS SHOWING THE UPPER LEVEL RIDGE BUILDING TO AROUND 590
DECAMETERS ON FRIDAY. HOWEVER, BY LATER FRIDAY AFTERNOON, THEY A
SHOWING A SHORTWAVE RIDING AROUND A THE RIDGE, WHICH MAY PRODUCE ENOUGH
FORCING, WHEN COMBINED WITH DAYTIME HEATING, TO ALLOW A FEW
SHOWERS TO DEVELOP IN THE WESTERN ZONES.
BY SATURDAY MORNING, MOISTURE RIDING AROUND A BERMUDA HIGH, WILL MOVE
IN FROM THE SOUTHWEST. THIS WILL POSSIBLY ALLOW SOME CONVECTIVE
CELLS TO FIRE UP LATE SATURDAY MORNING THROUGH SUNDAY MORNING. THERE
WILL BE A CONTINUOUS FLOW OF EMBEDDED SHORT WAVES RIDDING AROUND
THE RIDGE. HAVE SLOWLY INCREASED POPS THROUGH THE WEEKEND AS MORE
MOISTURE FEEDS INTO THE AREA.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
THE EXTENDED PERIOD WILL REMAIN WARM AND HUMID WITH A SOUTHWEST
FLOW ACROSS THE REGION DUE TO RETURN FLOW FROM HIGH PRESSURE
OFF THE MID ATLANTIC COAST. ALOFT A FLAT RIDGE WILL REMAIN OVER
THE NORTHEAST. DUE TO A RATHER MOIST AIR MASS ACROSS THE AREA WILL
CONTINUE WITH CHC POPS FOR PRIMARILY DIURNAL CONVECTION. LATEST
GFS/ECMWF INDICATE A SFC COLD FRONT WILL CROSS THE AREA ON
WEDNESDAY, FOLLOWED BY COOLER AND DRIER AIR FOR LATE WEEK.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
HIGH PRESSURE OVER THE REGION WILL PROVIDE VFR CONDITIONS THROUGH
THIS TAF PERIOD. AT KELM, THERE IS THE POTENTIAL FOR BRIEF MVFR
CONDITIONS BETWEEN 09Z-11Z DUE TO BR. EXPECT CLEAR SKIES THROUGH
LATE MORNING FOLLOWED BY FEW/SCT CU AROUND 6-7K FT THIS AFTERNOON
THEN CLEAR SKIES AGAIN OVERNIGHT.
LIGHT AND VARIABLE WINDS BECOMING W/SW THIS AFTERNOON AROUND 5
KNOTS THEN LIGHT AGAIN THIS EVENING.
OUTLOOK...
FRI...VFR.
SAT/SUN/MON...GENERALLY VFR. CHC FOR SCT MVFR IN
SHWRS/TSTMS...MAINLY IN THE AFTN/EVNG.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...SLI
NEAR TERM...SLI
SHORT TERM...SLI
LONG TERM...RRM
AVIATION...RRM
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1028 PM EDT FRI JUL 13 2012
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL EXTEND ACROSS THE REGION THROUGH
EARLY NEXT WEEK. A COLD FRONT WILL APPROACH FROM THE NORTH
BY THE END OF NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 1030 PM EDT FRIDAY...CONTRARY TO THE HRRR MODEL...SHOWERS
ARE EXPANDING ACROSS THE COASTAL WATERS AND THE COASTAL CAROLINAS
AS WELL. A GLANCE OUTSIDE THE NWS OFFICE A FEW MINUTES AGO SHOWS
LARGE TOWERING CUMULUS DOTTING THE SKY...EACH SHOWING UP AS 30-35
DBZ SHOWERS ON RADAR. WE`VE INCREASED POPS TO 30 PERCENT ALONG THE
COAST AND 20 PERCENT EVEN FAR INLAND WHERE SOME SHOWERS WERE
OBSERVED ON RADAR IN NORTHERN WILLIAMSBURG COUNTY AND WESTERN
ROBESON COUNTY. ANY OTHER CHANGES ARE MINOR. PREVIOUS DISCUSSION
FROM 730 PM FOLLOWS...
YESTERDAY`S OLD STALLED FRONT ACROSS THE EASTERN CAROLINAS IS NOW
IMPOSSIBLE TO FIND. THERE IS FOCUSED SYNOPTIC LOW-LEVEL
CONVERGENCE ACROSS THE WESTERN CAROLINAS AND NORTHERN GEORGIA THAT
MAY STILL BE A REMNANT OF THAT OLD BOUNDARY. HERE ON THE COAST
TROPICAL AIR CONTINUES TO STREAM ONSHORE IN A DEEP SOUTHEASTERLY
FLOW. PRECIPITABLE WATER VALUES ARE NEAR 2 INCHES AND DEEP-LAYER
LAPSE RATES ARE JUST SLIGHTLY STEEPER THAN MOIST ADIABATIC. THIS
IS THE PERFECT AIRMASS FOR SCATTERED TROPICAL SHOWERS LIKE WE`VE
SEEN MOST OF THE DAY. MODELS SHOW THIS ACTIVITY SHOULD WANE INLAND
OVER THE NEXT COUPLE OF HOURS BUT MAY CONTINUE ACROSS THE COASTAL
WATERS THROUGH MOST OF THE NIGHT... OCCASIONALLY AFFECTING THE
COASTAL COUNTIES WITH A FEW MINUTES OF LIGHT TO MODERATE RAIN.
THE AIRMASS WILL BEGIN TO DRY OUT FROM THE TOP LATE TONIGHT. WATER
VAPOR SATELLITE SHOWS A RIBBON OF DRY AIR APPROACHING THE
SOUTHEAST U.S. COAST IN ADVANCE OF A MID AND UPPER LEVEL
CIRCULATION STILL MANY HUNDREDS OF MILES EAST OF THE FLORIDA EAST
COAST. PRECIPITABLE WATER VALUES WILL BEGIN TO SLIDE DOWNWARD ALONG
THE COAST AFTER 2 AM WITH DRYING PARTICULARLY NOTED IN THE 850-500
MB LAYER.
LOW TEMPERATURES TONIGHT SHOULD AGAIN HOLD IN THE LOWER TO MIDDLE
70S...WITH WARMER READINGS ALONG THE BEACHES WITH THE ONSHORE
WINDS. CONSIDERABLE CONVECTIVE DEBRIS CLOUDINESS WILL ALLOW ONLY A
SLOW SLIDE IN TEMPERATURES THROUGH THE EVENING HOURS.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 340 PM EDT FRIDAY...THE DEEP LAYERED ATLC RIDGE WILL CONTINUE
TO DOMINATE THE WEATHER PATTERN ACROSS THE CAROLINAS THIS WEEKEND.
IN FACT...MID LEVEL HEIGHTS WILL BE BUILDING WITH TIME FROM E TO W
WHILE THE LOW LEVEL RIDGE AXIS INITIATES A SLOW SOUTHWARD DRIFTING
TREND LATE IN THE WEEKEND. WATER VAPOR SATELLITE IMAGERY INDICATES
AN ELONGATED SLOT OF DEEP LAYERED DRIER AIR BEYOND THE GULF STREAM
AND MODELS WERE DENOTING THIS FEATURE WITH PWATS NEAR OR BELOW 1.5
INCHES. AS THE RIDGE BUILDS W ON SAT...THIS SWATCH OF DRYING IS
FORECAST TO ADVECT INTO COASTAL AREAS ON SAT WHICH ENSURE DRY
WEATHER OVER THE SE HALF OF THE FORECAST AREA INCLUDING THE BEACHES
AFTER ONLY A SLIGHT CHANCE OF AN EARLY MORNING SHOWER FROM WEAK
COASTAL CONVERGENCE. SAT AFTERNOON...SLIGHTLY DEEPER MOISTURE
FURTHER INLAND TOWARD THE SANDHILLS SUGGEST KEEPING 20/30 POPS FOR
SEA BREEZE CONVECTION MOVING INLAND. THEN ON SAT NIGHT...DRY WEATHER
WITH MOSTLY CLEAR TO PARTLY CLOUDY SKIES ON TAP.
BY SUNDAY...THE SLOT OF DEEP LAYERED DRY AIR IS EXPECTED TO BE
SUPPLANTED BY DEEPER MOISTURE ONCE AGAIN...THIS TIMING SLIDING IN
FROM THE SE UNDERNEATH THE RIDGE IN ASSOCIATED WITH A WEAK UPPER
TROPOSPHERIC LOW CURRENTLY WELL NE OF THE BAHAMAS. MODELS SUGGEST
ISOLATED WITH SCATTERED CONVECTION ALONG THE SEA BREEZE POSSIBLE
ON SUNDAY IN MODEST H850 MB THETA-E ADVECTION FROM THE SE.
NO BIG CHANGES TO TEMPS OVER THE WEEKEND...SLIGHTLY WARMER INLAND
HIGHS ON SUNDAY A TAD HIGH LOW LEVEL THICKNESS VALUES AND SOME
STRONG MORNING HEATING. DIMINISHED RAIN CHANCE INDICATE SOME WARMER
AFTERNOON READINGS THAN THE PAST COUPLE OF DAYS.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 340 PM EDT FRIDAY...BROAD UPPER RIDGE WILL HAVE A LINGERING
MID LEVEL WEAKNESS IN THE SE STATES EARLY NEXT WEEK. DEEPER MOISTURE
SHOULD ALIGN FROM THE NORTHERN COASTAL PLAIN WSW TO THE SOUTH
CAROLINA UPSTATE OR JUST N THROUGH NW OF OUR INLAND TIER OF ZONES.
THE LOW LEVEL RIDGE AXIS SLIDES S OF THE REGION ON MON AND
CONTINUING INTO MID WEEK. THIS WILL ALLOW FOR TEMPS WARMING BACK
ABOVE CLIMO AND HEAT INDICES WILL ALSO CLIMB TO NEAR HEAT ADVISORY
LEVELS ONCE AGAIN BY MID WEEK. WE INDICATED LOW DIURNAL POPS ALONG
THE SEA BREEZE AND BOUNDARIES...BUT IT LOOKS MAINLY ISOLATED. LATE
WEEK...A COLD FRONT MAY SAG S THROUGH THE MID ATLC REGION INTO NORTH
CAROLINA...POTENTIALLY INCREASING BOTH POPS AND CLOUDS.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 00Z...PERIODS OF MVFR...POSSIBLY IFR INLAND...DUE TO
FOG/STRATUS EARLY SATURDAY MORNING. OTHERWISE EXPECT VFR.
ATTM VFR PREVAILS WITH CURRENT SATELLITE IMAGERY DEPICTING LINGERING
FEW/SCT/BKN LOW TO HIGH-LEVEL CLOUDS ACROSS THE AREA. WITH LIGHT
SOUTH-SOUTHEAST WINDS OVERNIGHT...FCST GUIDANCE SUGGESTS MVFR FOG
WITH LOW CIGS DUE TO STRATUS POSSIBLE BY EARLY MORNING. HAVE ALSO
INTRODUCED TEMPO IFR AT INLAND SITES. EXPECT ANY LINGERING FOG TO
CLEAR OUT BY MORNING..WITH LOW CIGS ANTICIPATED TO LINGER AROUND
2500-3000FT THROUGH POSSIBLY EARLY AFTERNOON. CANNOT RULE OUT AN
ISOLATED SHRA/TSRA ON SATURDAY...HOWEVER INVADING DRY AIR WILL LOWER
CHANCES COMPARED TO THOSE SEEN IN PAST FEW DAYS. OTHERWISE EXPECT
VFR WITH SOUTH-SOUTHEAST WINDS AOB 10 KTS.
EXTENDED OUTLOOK...PATCHY LOW CLOUDS OR LIGHT INLAND FOG POSSIBLE
DURING THE LATE NIGHT THROUGH MID MORNING HOURS THIS WEEKEND.
&&
.MARINE...
NEAR TERM /THROUGH 6 AM SATURDAY/...
AS OF 1030 PM FRIDAY...NO SIGNIFICANT CHANGES WITH THIS LATE
EVENING NEAR-TERM UPDATE. PREVIOUS DISCUSSION FROM 730 PM FOLLOWS...
ISOLATED SHOWERS ACROSS THE COASTAL WATERS MAY INCREASE IN
COVERAGE SLIGHTLY LATER THIS EVENING AND OVERNIGHT AS WE REMAIN IN
A WARM AND HUMID TROPICAL AIRMASS. OBJECTIVE COMPUTER MODELS
INDICATE ACTIVITY SHOULD NOT BECOME WIDESPREAD AT ANY RATE.
SOUTHEAST WINDS 10-12 KNOTS SHOULD CONTINUE THROUGH MOST OF THE
NIGHT...PERHAPS BACKING TO THE EAST OR EVEN NORTHEAST AT THE
IMMEDIATE COASTLINE LATE TONIGHT WITH THE NOCTURNAL INVERSION
SETTING UP. SEAS RANGE FROM 2 FT NEARSHORE TO 3 FT OFFSHORE WITH 7
SECOND DOMINANT PERIODS...AND LITTLE CHANGE IS ANTICIPATED
OVERNIGHT.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 340 PM FRIDAY..FAIRLY WEAK ONSHORE FLOW EXPECTED ON SAT
WITH SPEEDS LESS THAN 15 KT AND THEN DECREASING FURTHER SAT NIGHT AS
SURFACE HIGH PRES BLANKETS THE CAROLINAS AND ADJACENT WATERS. LATE
IN THE WEEKEND...SURFACE FLOW OVER THE WATERS WILL VEER TO MORE
SOUTHERLY COMPONENT AS THE RIDGE AXIS SAGS S. SEAS AVERAGE 2-3 FT
OVER THE WEEKEND...OCCASIONALLY 4 FT WELL OFFSHORE.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 340 PM FRIDAY...SOUTHWEST WINDS GENERALLY IN THE 10 TO 15 KT
RANGE AND SEAS AVERAGING 2 TO 4 FT THROUGH THE PERIOD...THE MOST
COMMON SET OF CONDITIONS LOCALLY FOR THE SUMMER. BY WED...SW FLOW
MAY BEGIN TO INCREASE WITH DIURNAL/NOCTURNAL SURGES OFF THE COAST
AND SEAS INCREASING TO 3 TO 5 FT...HIGHEST SE OF CAPE FEAR AND WELL
OFFSHORE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TRA
NEAR TERM...TRA
SHORT TERM...99
LONG TERM...99
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
315 AM EDT THU JUL 12 2012
.SYNOPSIS...
A STATIONARY FRONT WILL LINGER OFF THE NORTH CAROLINA COAST
INTO FRIDAY...WHILE SLOWLY WEAKENING. HIGH PRESSURE BUILDS IN
FROM THE WESTERN ATLANTIC THIS WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 3 AM THU...THE BROAD UPPER TROUGH ACROSS THE NERN STATES IS
SLOWLY WEAKENING AS AN UPPER LOW PUSHES INTO THE CANADIAN
MARITIMES ALLOWING FOR GRADUAL HEIGHT RISES ACROSS ERN NC TODAY
WHILE A FRONTAL BOUNDARY WILL REMAIN STALLED ALONG OR JUST OFF
THE NC COAST. CONVECTION FROM LAST EVENING HAS SINCE DISSIPATED
WITH JUST A FEW AREAS OF STRATIFORM RAIN PERSISTING ACROSS THE
SOUNDS AND OBX. HRRR INDICATES LIGHT SHOWERS TO CONTINUE IN THIS
SAME GENERAL AREA THROUGH MOST OF THE MORNING HOURS AND WILL KEEP
CHC POPS IN THIS AREA AND WILL HAVE SLT CHC POPS ELSEWHERE.
WHILE UPPER LEVEL SUPPORT WEAKENS TODAY A VERY MOIST AIRMASS WILL
PERSIST ACROSS THE REGION WITH PW`S IN EXCESS OF 2" AND EXPECT A
DESCENT COVERAGE OF CONVECTION AGAIN THIS AFTERNOON. BEST CHANCES
WILL BE INLAND WHERE GREATER INSTABILITY WILL RESIDE...CAPE AROUND
1000-1500 J/KG...AND SEA BREEZE AND OTHER LINGERING BOUNDARY
INTERACTIONS LIKELY TO OCCUR. WITH HIGH PW VALUES...LOCALLY HEAVY
RAINFALL WILL BE POSSIBLE AGAIN AND COULD SEE LOCALIZED FLOODING
OF POOR DRAINAGE AREAS IF STORMS TRAIN OVER THE SAME AREA. A FEW
STORMS COULD BECOME STRONG PRODUCING GUSTY WINDS BUT THE OVERALL
SEVERE THREAT IS EXPECTED TO BE LOW. LITTLE CHANGE IN LOW LEVEL
THICKNESSES WITH ABUNDANT CLOUDS ACROSS THE REGION EXPECT HIGHS
SIMILAR TO YDA...IN THE L/M80S.
&&
.SHORT TERM /TONIGHT/...
AS OF 3 AM THU...LITTLE CHANGE IN THE OVERALL PATTERN TONIGHT WITH
THE FRONT REMAINED STALLED ACROSS THE AREA AND GRADUAL HEIGHT
RISES ALOFT. CONVECTION WILL GRADUALLY DISSIPATE THROUGH THE
EVENING HOURS WITH LOSS OF INSOLATION BUT STRATIFORM PCPN WILL
LIKELY PERSIST INTO THE EARLY MORNING HOURS...ESPECIALLY NEAR THE
COAST AS HAS OCCURRED THE PREVIOUS COUPLE NIGHTS. SIGNIFICANT
CLOUDS COVERAGE WILL HOLD LOWS MAINLY IN THE 68-75 DEGREE RANGE.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 2 AM THU...FORCING ALOFT BEGINS TO WEAKEN FRI AS SUBTROPICAL
RIDGE OVER THE WESTERN ATLANTIC BUILDS WEST. STILL HAVE DEEP
MOISTURE IN PLACE WITH PRECIP WATER NEAR 2 INCHES SO WILL CONT CHC
POPS MAINLY INLAND FRI AFTN. OVER THE WEEKEND PRECIP WTR LOWERS AND
EXPECT LITTLE IF ANY CONVECTION INTO MON. MDLS DIFFER A BIT TUE AND
WED WITH ECMWF HOLDING ON TO THE RIDGE WHILE GFS SHOWS BROAD UPR TRF
TO THE W...KEPT ISOLD POPS IN DURING THE AFTN BOTH TUE AND WED. HIGH
TEMPS WILL LIKELY HOLD A LITTLE BELOW 90 INLAND FRI THEN REACH
AROUND 90 SAT. FROM SUNDAY ON EXPECT LOWER 90S INLAND WITH RDG NEAR
OR JUST TO THE E.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
.SHORT TERM /THROUGH TONIGHT/...
AS OF 3 AM THU...ABUNDANT MOISTURE PERSISTS ACROSS RTES THROUGH
THE SHORT TERM WITH A FRONTAL BOUNDARY STALLED ALONG OR JUST OFF
THE COAST. WIDELY VARIABLE CIGS FROM LIFR TO VFR WILL CONTINUE
ACROSS THE REGION THROUGH THE EARLY MORNING HOURS WITH CLOUD COVER
LIMITING BEST RADIATIONAL COOLING AND WIDESPREAD FOG DEVELOPMENT.
SOMEWHAT IMPROVED CIGS TO MVFR/VFR WILL DEVELOP BY LATE MORNING
AND AFTERNOON OUTSIDE OF CONVECTION. TSTM DEVELOPMENT EXPECTED
AGAIN THIS AFTERNOON WHICH WILL BRING VERY HEAVY RAINFALL AND
COULD BRING STRONG WIND GUSTS TO THE TERMINALS THIS AFTERNOON AND
EVENING. CLOUD COVERAGE WILL LIKELY LIMIT WIDESPREAD FOG
DEVELOPMENT AGAIN TONIGHT BUT EXPECT TO SEE WIDELY VARIABLE
CIGS/VSBYS AGAIN LATE TONIGHT OCCASIONALLY LOWERING TO LIFR.
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 2 AM THU...FOG/STRATUS GOOD BET FRI MORN WITH LIGHT TO CALM
WINDS AND MOIST LOW LVLS. ISOLD/SCT CONVECTION EXPECTED DURING THE
AFTN FRIDAY AND SATURDAY WITH POSSIBLY SOME BRIEF REDUCTIONS IN
CIGS/VSBYS. UPPER RIDGE OVER THE WESTERN ATLANTIC EXPANDS OVER THE
REGION OVER THE WEEKEND AND INTO EARLY NEXT WEEK WITH MAINLY VFR
AFTER ANY EARLY MORNING FOG/STRATUS BURNS OFF.
&&
.MARINE...
.SHORT TERM /THROUGH TONIGHT/...
AS OF 3 AM THU...A FRONTAL BOUNDARY WILL REMAIN STALLED ACROSS THE
SOUTHERN AND CENTRAL WATERS THROUGH THE SHORT TERM BRINGING LIGHT
WINDS AOB 15 KT ACROSS THE WATERS...GENERALLY S/SWLY ACROSS THE
SRN WATERS AND NE/ELY ACROSS THE NRN WATERS. SEAS WILL REMAIN
AROUND 2-4 FT MAINLY IN MEDIUM PERIOD SWELLS AROUND 9-11 SEC BUT A
SHORTER PERIOD CHOP AROUND 5 SEC MAY PERSIST ACROSS NEARSHORE
ONSLOW BAY THIS MORNING.
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 2 AM THU...WEAK FRONT ALONG THE CST EARLY FRI WILL DISSIPATE
WITH LIGHT S/SE WINDS DEVELOPING DURING THE AFTN. HIGH PRES WELL
OFFSHORE WILL BECOME DOMINANT FEATURE FROM SAT ON WITH MAINLY S/SW
WINDS OF 5 TO 15 KT...HIGHEST MON AS TROF DEVELOPS TO THE W.
SEAS WILL BE 2 TO 3 FEET FRI...AN INCREASING SE SWELL WILL LEAD TO
SOME 4 TO POSS 5 FOOT SEAS LATER SAT INTO MON.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SK
NEAR TERM...SK
SHORT TERM...SK
LONG TERM...RF
AVIATION...RF/SK
MARINE...RF/SK
AREA FORECAST DISCUSSION
NWS RALEIGH NC
300 AM EDT THU JUL 12 2012
.SYNOPSIS...
A VERY MOIST AIR MASS AND WEAK SURFACE FRONT WILL PERSIST OVER THE
AREA THROUGH THURSDAY...BRINGING PERIODS OF SHOWERS AND
THUNDERSTORMS. A HIGH PRESSURE RIDGE OFFSHORE WILL THEN SLOWLY
BEGIN TO EXTEND ACROSS THE AREA THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 1050 PM...
CURRENT RADAR IMAGERY SHOWS SHOWERS DISSIPATING ACROSS THE NC/SC
BORDER AND ACROSS PORTIONS OF THE NORTHWEST PIEDMONT...ELSEWHERE
SHOWERS HAVE LONG SINCE ENDED AND WILL LIKELY REMAIN DRY FOR THE
NEXT SEVERAL HOURS. HAVE DECREASED PRECIP CHANCES/AMOUNTS ACROSS
MUCH OF THE AREA TO REFLECT THAT. 00Z 850 MB ANALYSIS SHOWS THE
FRONT SET UP ACROSS CENTRAL NC FROM WEST TO EAST. AROUND
07Z THE 21Z HRRR 1KM REFLECTIVITY FORECASTS SHOW THE CONVECTION OVER
NORTHERN GA AND WESTERN SC MOVING NNE TOWARD CENTRAL NC. THIS IS
SUPPORTED BY THE 00Z 250 MB ANALYSIS...WHICH SHOWS A JET STREAK JUST
TO THE WSW OF NC AND AND THE 700 MB SHEAR AXIS AND POSSIBLE
REFLECTION OF THE FRONT AT 850 MB. THUS...HAVE IN GENERAL THE
HIGHEST RAIN CHANCE FORECAST ACROSS THE SOUTH AND SOUTHWEST
OVERNIGHT...WITH LOWER POPS AROUND 30 TO 40 PERCENT ELSEWHERE. LOW
TEMPERATURES IN THE MID 60S NORTH TO AROUND 70 SOUTH.
850 MILLIBAR TROUGH IS EXPECTED TO DROP TOWARD THE SOUTH CAROLINA
BORDER TONIGHT BEFORE DISSIPATING THURSDAY IN SOUTH SOUTHEAST FLOW
AROUND AN OFFSHORE HIGH. A SURFACE TROUGH JUST INLAND FROM THE COAST
WILL PERSIST THROUGH THE PERIOD. WITH WINDS NORTHEAST TO EAST
THURSDAY AND AMPLE CLOUDINESS... EXPECT ANOTHER DAY SIMILAR TO
TODAY. SCATTERED RAIN SHOWERS AND A THUNDERSTORM OR TWO... WITH HIGH
TEMPERATURES UPPER 70S TO MID 80S. WITH LITTLE UPPER LEVEL SUPPORT
FOR CONVECTION FORECAST THURSDAY NIGHT... RAIN CHANCES DROP TO 30
PERCENT. LOW TEMPERATURES UPPER 60S TO LOWER 70S.
ON FRIDAY...DEEPER MOISTURE AND PERSISTENT SHEAR AXIS WILL STILL BE
WRAPPED AROUND THE RIDGE...PRODUCING BETTER CONVECTIVE COVERAGE WITH
POPS IN THE HIGH CHANCE...50 PERCENT RANGE. TEMPERATURES WILL BE
TEMPERED BY THE HEAVY CLOUD AND PRECIPITATION COVERAGE...EXPECTING
OUR LAST DAY OF HIGHS TOPPING OUT IN THE MID 80S.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 250 AM THURSDAY...
UPPER LEVEL RIDGING WILL BE BUILDING WEST FROM THE ATLANTIC AND INTO
THE MID ATLANTIC REGION THROUGHOUT THIS PERIOD. AS A RESULT...WE
WILL SEE DECREASING PRECIP CHANCES...HOWEVER MODELS STILL PROG
ENOUGH MOISTURE ON THE WESTERN PERIPHERY OF THE RIDGE (PWATS VALUES
RANGING FROM 1.6 TO 1.9 INCHES) TO WARRANT CHANCE POPS ACROSS THE
WESTERN HALF OF THE FORECAST AREA THROUGH SATURDAY (WILL ONLY SHOW
SLIGHT CHANCE ACROSS EASTERN PORTIONS DUE MORE INFLUENCE FROM THE
UPPER LEVEL RIDGE). SATURDAY NIGHT SHOULD BE MOSTLY DRY AS WE
TRANSITION BACK INTO DIURNALLY DRIVEN CONVECTION. SATURDAY SHOULD BE
OUR LAST DAY OF BELOW NORMAL TEMPS...WITH HIGHS EXPECTED TO BE
SLIGHTLY BELOW NORMAL...GENERALLY IN THE MID/UPPER 80S TO NEAR 90
DEGREES. OVERNIGHT LOWS WILL CONTINUE TO BE IN THE UPPER 60S TO
LOWER 70S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 250 AM THURSDAY...
A RETURN TO A FAIRLY TYPICAL SUMMERTIME PATTERN IS EXPECTED AS UPPER
LEVEL RIDGING WILL BE IN PLACE OVER THE REGION THROUGH THE LONG TERM
PERIOD...WITH MAYBE SOME SLIGHT WEAKENING TOWARDS THE MIDDLE OF NEXT
WEEK. WITH WARMING TEMPS ALOFT AND A DECREASE IN DEEP LAYER MOISTURE
(PWAT VALUES PROGGED TO REMAIN BELOW 1.5 INCHES)...AM EXPECTING ONLY
ISOLATED DIURNALLY DRIVEN POPS EACH AFTERNOON. INCREASING HEIGHTS
ALOFT AND MORE IN THE WAY OF SUNSHINE WILL RESULT IN HIGH TEMPS
TRENDING BACK TO ABOVE NORMAL...WITH MOSTLY LOW 90S EXPECTED EACH
DAY. OVERNIGHT LOWS WILL GENERALLY REMAIN IN THE LOW/MID 70S.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 145 AM THURSDAY...
MVFR CEILINGS ARE OBSERVED FROM KGSO/KINT TO KRDU AT 06Z...WITH IFR
AND LIFR CEILINGS IN AND AROUND THE KFAY AREA. THESE CONDITIONS
SHOULD CONTINUE FOR THE REMAINDER OF THE NIGHT...POSSIBLY DROPPING
TO IFR/LIFR AT KGSO/KINT BY 08-09Z AS AN AREA OF SHOWERS MOVES INTO
THE FOOTHILLS FROM THE SOUTHWEST. DESPITE ABUNDANT MOISTURE OVER
THE AREA...FORECAST SOUNDINGS SHOW DRYING IN THE LOW LEVELS AND
MIXING WHICH SHOULD ALLOW CONDITIONS TO LIFT TO MVFR OR EVEN VFR BY
LATE MORNING. SCATTERED SHOWERS AND THUNDERSTORMS ARE THEN EXPECTED
FOR IN CENTRAL NORTH CAROLINA THIS AFTERNOON. OVERALL DEVELOPMENT IN
THE AFTERNOON MAY BE A LITTLE LATER...AND SHOWERS MAY BECOME MORE
NUMEROUS ESPECIALLY AROUND KFAY LATE IN THE DAY WHERE HIGHER
INSTABILITY WILL LIE.
BEYOND THE 06Z VALID TAF PERIOD...THE CHANCES FOR SHOWERS WILL BEGIN
TO SLOWLY DIMINISH DAILY FRIDAY INTO MONDAY. HOWEVER...ISOLATED TO
WIDELY SCATTERED SHOWERS AND THUNDERSTORMS FOCUSED ON THE AFTERNOON
AND EARLY EVENING ARE POSSIBLE. IN ADDITION TO CONDITIONS WITH ANY
THUNDERSTORMS...WITH LINGERING LOW-LEVEL MOISTURE...PERIODS OF
SUB-VFR CONDITIONS IN LOW CLOUDS AND FOG CAN BE EXPECTED. THE LATEST
FORECAST GUIDANCE WOULD SUGGEST THE BETTER POTENTIAL OF LOW CLOUDS
LATER IN THE WEEKEND AND EARLY NEXT WEEK BEING TOWARD THE TRIAD.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RAH
NEAR TERM...KC/MLM
SHORT TERM...KRR
LONG TERM...KRR
AVIATION...DJF/SMITH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
145 AM EDT THU JUL 12 2012
.SYNOPSIS...
A VERY MOIST AIR MASS AND WEAK SURFACE FRONT WILL PERSIST OVER THE
AREA TODAY...BRINGING PERIODS OF SHOWERS AND THUNDERSTORMS. A HIGH
PRESSURE RIDGE OFFSHORE WILL THEN SLOWLY BEGIN TO EXTEND ACROSS THE
AREA THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 1050 PM...
CURRENT RADAR IMAGERY SHOWS SHOWERS DISSIPATING ACROSS THE NC/SC
BORDER AND ACROSS PORTIONS OF THE NORTHWEST PIEDMONT...ELSEWHERE
SHOWERS HAVE LONG SINCE ENDED AND WILL LIKELY REMAIN DRY FOR THE
NEXT SEVERAL HOURS. HAVE DECREASED PRECIP CHANCES/AMOUNTS ACROSS
MUCH OF THE AREA TO REFLECT THAT. 00Z 850 MB ANALYSIS SHOWS THE
FRONT SET UP ACROSS CENTRAL NC FROM WEST TO EAST. AROUND
07Z THE 21Z HRRR 1KM REFLECTIVITY FORECASTS SHOW THE CONVECTION OVER
NORTHERN GA AND WESTERN SC MOVING NNE TOWARD CENTRAL NC. THIS IS
SUPPORTED BY THE 00Z 250 MB ANALYSIS...WHICH SHOWS A JET STREAK JUST
TO THE WSW OF NC AND AND THE 700 MB SHEAR AXIS AND POSSIBLE
REFLECTION OF THE FRONT AT 850 MB. THUS...HAVE IN GENERAL THE
HIGHEST RAIN CHANCE FORECAST ACROSS THE SOUTH AND SOUTHWEST
OVERNIGHT...WITH LOWER POPS AROUND 30 TO 40 PERCENT ELSEWHERE. LOW
TEMPERATURES IN THE MID 60S NORTH TO AROUND 70 SOUTH.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
AS OF 250 PM...
850 MILLIBAR TROUGH IS EXPECTED TO DROP TOWARD THE SOUTH CAROLINA
BORDER TONIGHT BEFORE DISSIPATING THURSDAY IN SOUTH SOUTHEAST FLOW
AROUND AN OFFSHORE HIGH. A SURFACE TROUGH JUST INLAND FROM THE COAST
WILL PERSIST THROUGH THE PERIOD. WITH WINDS NORTHEAST TO EAST
THURSDAY AND AMPLE CLOUDINESS... EXPECT ANOTHER DAY SIMILAR TO
TODAY. SCATTERED RAIN SHOWERS AND A THUNDERSTORM OR TWO... WITH HIGH
TEMPERATURES UPPER 70S TO MID 80S. WITH LITTLE UPPER LEVEL SUPPORT
FOR CONVECTION FORECAST THURSDAY NIGHT... RAIN CHANCES DROP TO 30
PERCENT. LOW TEMPERATURES UPPER 60S TO LOWER 70S.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 135 PM WEDNESDAY...
WILL SEE GRADUAL DRYING AND A WARMING TREND LATE WEEK INTO THE
WEEKEND AS DEEP RIDGING BUILDS WEST OFF THE ATLANTIC INTO THE MID
ATLANTIC STATES.
ON FRIDAY...DEEPER MOISTURE AND PERSISTENT SHEAR AXIS WILL STILL BE
WRAPPED AROUND THE RIDGE...PRODUCING BETTER CONVECTIVE COVERAGE WITH
POPS IN THE HIGH CHANCE...50 PERCENT RANGE. TEMPERATURES WILL BE
TEMPERED BY THE HEAVY CLOUD AND PRECIPITATION COVERAGE...
EXPECTING OUR LAST DAY OF HIGHS TOPPING OUT IN THE MID 80S.
RIDGING WILL BE FIRMLY IN PLACE FROM SATURDAY ONWARD...WITH A
WARM...NOT HOT... AND MOIST AIR MASS IN PLACE. TEMPERATURES WILL
BE ON THE INCREASE... WITH HIGHS MOSTLY IN THE UPPER 80S
SATURDAY... EDGING UP TO THE VERY HIGH 80S TO LOWER 90S SUNDAY...
AND IN THE LOWER 90S MONDAY THROUGH WEDNESDAY. NO CHANGE OF AIR
MASS IS IN SIGHT... SO PERSISTENT MINIMUM TEMPERATURES IN THE 70
TO 75 RANGE WILL BE THE RULE THROUGH THE PERIOD.
THE STRENGTHENING RIDGE WILL CAP AND DAMPEN CONVECTIVE
ACTIVITY... WITH LARGELY DIURNAL CHANCE POPS THROUGH THE WEEKEND
DIMINISHING TO SLIGHT CHANCES MONDAY THROUGH WEDNESDAY. THESE
DIURNAL POPS WILL BE GRADUATED HIGHER TOWARDS THE WEST WHERE
DIFFERENTIAL HEATING AND SUBSEQUENT EASTWARD DRIFT WILL INCREASE THE
CHANCES SOME SLIGHT DEGREE.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 145 AM THURSDAY...
MVFR CEILINGS ARE OBSERVED FROM KGSO/KINT TO KRDU AT 06Z...WITH IFR
AND LIFR CEILINGS IN AND AROUND THE KFAY AREA. THESE CONDITIONS
SHOULD CONTINUE FOR THE REMAINDER OF THE NIGHT...POSSIBLY DROPPING
TO IFR/LIFR AT KGSO/KINT BY 08-09Z AS AN AREA OF SHOWERS MOVES INTO
THE FOOTHILLS FROM THE SOUTHWEST. DESPITE ABUNDANT MOISTURE OVER
THE AREA...FORECAST SOUNDINGS SHOW DRYING IN THE LOW LEVELS AND
MIXING WHICH SHOULD ALLOW CONDITIONS TO LIFT TO MVFR OR EVEN VFR BY
LATE MORNING. SCATTERED SHOWERS AND THUNDERSTORMS ARE THEN EXPECTED
FOR IN CENTRAL NORTH CAROLINA THIS AFTERNOON. OVERALL DEVELOPMENT IN
THE AFTERNOON MAY BE A LITTLE LATER...AND SHOWERS MAY BECOME MORE
NUMEROUS ESPECIALLY AROUND KFAY LATE IN THE DAY WHERE HIGHER
INSTABILITY WILL LIE.
BEYOND THE 06Z VALID TAF PERIOD...THE CHANCES FOR SHOWERS WILL BEGIN
TO SLOWLY DIMINISH DAILY FRIDAY INTO MONDAY. HOWEVER...ISOLATED TO
WIDELY SCATTERED SHOWERS AND THUNDERSTORMS FOCUSED ON THE AFTERNOON
AND EARLY EVENING ARE POSSIBLE. IN ADDITION TO CONDITIONS WITH ANY
THUNDERSTORMS...WITH LINGERING LOW-LEVEL MOISTURE...PERIODS OF
SUB-VFR CONDITIONS IN LOW CLOUDS AND FOG CAN BE EXPECTED. THE LATEST
FORECAST GUIDANCE WOULD SUGGEST THE BETTER POTENTIAL OF LOW CLOUDS
LATER IN THE WEEKEND AND EARLY NEXT WEEK BEING TOWARD THE TRIAD.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RAH
NEAR TERM...KC
SHORT TERM...RAH
LONG TERM...MLM
AVIATION...DJF/SMITH
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
1039 AM CDT THU JUL 12 2012
.DISCUSSION...PULLING OUT HAIR TRYING TO FIGURE DETAILS FOR
TODAY. UPPER CIRCULATION ACROSS SOUTHERN MANITOBA WILL BE NEAR THE
NORTHERN VALLEY AROUND 00Z. 15Z WATER VAPOR IMAGERY ALSO INDICATES
A COUPLE CIRCULATIONS ACROSS SOUTHERN NORTH DAKOTA...WHICH WILL BE
THROUGH THE FA BY 00Z. NOT SEEING ANY ADDITIONAL WAVES THAT WILL
AFFECT THE REGION THIS AFTERNOON. YESTERDAY...SEVERE WEATHER IN
SOUTHWEST/SOUTH CENTRAL NORTH DAKOTA WAS ASSOCIATED WITH A
STRONGER WAVE...WHILE CAPPING HELD WHERE THERE WAS NO HELPING
LIFT. TEMPERATURES AND ASSOCIATED MLCAPE VALUES WILL DEPEND ON
CLOUD COVER THIS AFTERNOON. A MAJORITY OF THE FA SHOULD BE AT
LEAST PARTLY CLOUDY (EXCPET FOR THE FAR NORTHERN FA CLOSER TO THE
MAIN UPPER LOW). GIVEN DEWPOINT VALUES MID-UPPER 60S AND POSSIBLE
POOLING NEAR 70F...MLCAPE VALUES LIKELY WILL BE AROUND 2000-2500
J/KG IN AREAS. HOWEVER...MODEL SOUNDINGS INDICATE A WARM 850MB-
700MB LAYER THAT WILL PROVIDE A CAP. GIVEN THE ABOVE
THINKING...MUCH OF TODAY SHOULD BE DRY. THE BEST CHANCES FOR
THUNDER WILL BE NEAR THE UPPER CIRCULATION THIS AFTERNOON NEAR THE
INTERNATIONAL BORDER (12Z HRRR INDICATES ACTIVITY AFTER 20Z ACROSS
ONLY THE FAR NORTHERN FA). WILL ADJUST POPS A BIT TO THIS
THINKING. WILL KEEP THE SEVERE MENTION WHERE THE SLIGHT RISK AREA
IS LOCATED GIVEN MODERATE INSTABILIY...ALTHOUGH DEEP LAYER WILL BE
WEAK. LIKELY WILL BE PULSE TYPE LARGE HAIL STORMS...AND HEAVY RAIN
GIVEN SLOW STORM MOTIONS.
&&
.AVIATION...MOST SITES WILL BE VFR TODAY...ALTHOUGH THERE IS THE
POTENTIAL FOR BRIEF PERIODS OF MVFR CIGS. SCATTERED TO ISOLATED
THUNDER THIS AFTERNOON/EVENING...NOT ENOUGH CONFIDENCE THAT THEY
WILL BE ABLE TO HIT A TAF SITE.
&&
.PREV DISCUSSION... /ISSUED 412 AM CDT THU JUL 12 2012/
SHORT TERM...TODAY THROUGH SATURDAY NIGHT.
WATER VAPOR LOOP AND RADAR INDICATED A SHORT WAVE OVER EASTERN ND
AND WAS MOVING EAST ABOUT 30 KNOTS. UPPER LEVEL TROUGH REMAINS OVER
NORTHWEST ND. UPPER LEVEL TROUGH FORECAST TO MOVE ACROSS THE
FORECAST AREA TONIGHT AND FRI MORNING. SLIGHT RISK OF SEVERE
THUNDERSTORMS FOR THIS AFTERNOON AND EVENING. WILL INCLUDE CHANCE
FOR LARGE HAIL.
AFTERNOON HEATING AND UPPER LOW OVER NORTHWEST ND WILL MOVE THROUGH
AND PRODUCE SCATTERED THUNDERSTORMS ACROSS THE FORECAST AREA FOR
THIS AFTERNOON AND EVENING. SYSTEM CLOSES OFF AT LOWER LEVELS WHILE
UPPER WAVE REMAINS OPEN. PRECIPITABLE WATER RISES TO AROUND 1.75
INCHES FOR THIS AFTERNOON. WITH SYSTEM CLOSING OFF AT LOWER LEVELS
PRECIPITATION WILL BE SLOW TO MOVE OUT OF THE AREA. WILL KEEP POPS
MAINLY IN THE EASTERN ZONES FOR FRI AND FRI NIGHT.
SHOWALTER INDEX LOWERS WITH AFTERNOON HEATING AND COLD FRONT TO
BACKDOOR THE AREA. CONVECTIVE TEMPS FORECAST TO BE IN THE MIDDLE
80S. WILL ADD LOW POPS ON THE MN SIDE SAT AFTERNOON AND EVENING.
LONG TERM (SUN-WED)...
LONG RANGE MODELS HAVE SOME ISSUES IN REGARDS TO STRENGTH OF THE 500
MB RIDGE FROM THE SOUTHWESTERN U.S. INTO THE CENTRAL PLAINS. 00Z
CANADIAN GEM MODEL IS A BIT STRONGER AND FARTHER NORTH WITH RIDGE
AND THUS A BIT WARMER. 00Z ECMWF IS WARM AS WELL WITH 00Z GFS A BIT
FLATTER AND NOT AS WARM. THIS HAS BEEN THE TREND FOR THE PAST FEW
WEEKS AND THE WARMER SOLN HAS SO FAR WORKED OUT BEST. THUS WENT AT
OR JUST ABOVE GIVEN ALL BLEND HIGH TEMPS NEXT WEEK. WARMEST DAYS
WILL BE MON-TUE. AS FOR PRECIPITATION....TYPICAL VERY LOW
CONFIDENCE MID SUMMER ISSUES. BLEND FROM MODELS WOULD INDICATE BEST
CHANCES SUN NIGHT-MON TIME FRAME AND THEN AGAIN THURSDAY. GIVEN
PATTERN AND SUCH LOW CONFIDENCE WENT ALONG WITH ALL BLEND POPS WHICH
GIVES CHANCES MOST PERIODS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
TG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
231 PM EDT THU JUL 12 2012
.SYNOPSIS...
A WEAK BUT MOIST AREA OF HIGH PRESSURE WILL REMAIN NOSED INTO THE
REGION THE NEXT FEW DAYS. BERMUDA HIGH PRESSURE WILL THEN BUILD IN
LATER THIS WEEKEND AND LINGER INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 215 PM...WATER VAPOR IMAGERY SHOWED AN ELONGATED TROUGH AXIS
ALONG THE MS RIVER VALLEY. WEAK VORTICITY LOBES AHEAD OF THIS
FEATURE CONTINUE TO RIPPLE NE THROUGH ERN TN...BRUSHING EXTREME WRN
NC AS WELL. FARTHER EAST...WEAK COLD AIR DAMMING REMAINS IN PLACE
EAST OF THE MOUNTAINS...AND CLOUDS THROUGHOUT THE AREA HAVE BEEN
SLOW TO LIFT AND EVEN SLOWER TO SCATTER IN THE MOIST PROFILES WITH
WEAK UPGLIDE APPARENT. SFC BASED CAPE ON THE LATEST LAPS ANALYSIS
SHOWS AROUND 1000 J/KG ALONG THE SE FRINGE OF THE AREA. THESE VALUES
WILL RISE ALONG THE PERIPHERY OF THE WEDGE...AND VALUES OF 500 TO
1000 J/KG ARE LIKELY WITHIN THE SHALLOW WEDGE LAYER WHERE BREAKS
DEVELOP. ALTHOUGH THE MORNING RAOB AND CURRENT LAPS SOUNDINGS
EXHIBIT ABUNDANT MOISTURE...LAPSE RATES ARE WEAK AND WINDS ALOFT ARE
FAIRLY LIGHT...SO SEVERE TSTM POTENTIAL IS QUITE LIMITED. WITH
PRECIPITABLE WATER VALUES RANGING FROM 1.6 INCHES IN THE MTNS TO
NEARLY 2 INCHES NEAR CLT...THE LIGHT STEERING FLOW MAY LEAD TO
POCKETS OF HEAVY RAINFALL WHERE RATES ARE HIGHEST AND ANY DEGREE OF
TRAINING OR UPSLOPE ANCHORING DEVELOPS. WILL KEEP THE BEST
AFTN/EVENING POPS FOCUSED ON THE MTNS CLOSER TO THE UPPER FORCING
AND WHERE SE TO S UPSLOPE FLOW IS BEST. WILL KEEP THE BEST TSTM
CHANCES ALONG THE SE FRINGE IN THE HIGHEST INSTABILITY. POPS MAY
THEN FOCUS ON THE ERN ESCARPMENT OVERNIGHT AS INSTABILITY WANES BUT
UPSLOPE CONTINUES.
850 MB WARM ADVECTION AND LOW LEVEL UPSLOPE FLOW WILL PERSIST ACROSS
THE SRN APPALACHIANS AND VICINITY THROUGH FRIDAY. HOWEVER...SLIGHTLY
LESS MOISTURE IS EVIDENT IN MODEL PROFILES ON FRI COMPARED TO TODAY
AS AN ATLANTIC RIDGE BUILDS WESTWARD. THIS SHOULD ALLOW CLOUDS TO
LIFT AND PARTIALLY SCATTER A BIT MORE QUICKLY...LEADING TO WARMER
MAXES...AND INSTABILITY BUBBLING TO 1500 TO 2000 J/KG CAPE. WILL
WARM MAX TEMPS AT LEAST A CATEGORY OVER TODAY AND FEATURE LIKELY
WEST TO SOLID CHC EAST POPS...WITH MORE OF A THUNDER MENTION.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AS OF 200 PM THURSDAY...THE PERSISTENT UPPER TROUGH OVER THE LOWER
MISS VALLEY/TENN VALLEY WILL CONTINUE TO WEAKEN THROUGH THE
WEEKEND...AS AN UPPER RIDGE BUILDS WESTWARD FROM THE WESTERN
ATLANTIC. THIS WILL EVENTUALLY ALLOW FOR THE TRANSITION TO MORE OF A
TYPICAL SUMMERTIME/BERMUDA HIGH PATTERN DURING THE SHORT TERM.
FRIDAY NIGHT THROUGH SATURDAY NIGHT...THE AIR MASS WILL REMAIN
UNSTABLE AND UNSEASONABLY MOIST...WITH A DEEP (ALBEIT WEAK)
SOUTHEAST FLOW. THIS SHOULD RESULT IN AT LEAST SCATTERED SHOWERS AND
TSRA OVER THE AREA...WITH THE BEST POPS OCCURRING ALONG THE BLUE
RIDGE DURING THE AFTERNOON/EVENINGS. THERE ARE ALSO SIGNALS IN THE
MODEL GUIDANCE THAT OUTFLOW FROM SEA BREEZE CONVECTION MAY PUSH AS
FAR WEST/NORTH AS THE PIEDMONT SATURDAY (NOT AT ALL UNUSUAL IN SE
FLOW SITUATIONS)...SO SOLID CHANCE POPS WILL ALSO BE CARRIED THERE.
BY SUNDAY AFTERNOON...MODEL GUIDANCE ADVECTS MUCH DRIER DEEP LAYER
AIR INTO THE REGION...AND THERE IS IN FACT VERY LITTLE QPF RESPONSE
OUTSIDE THE MTNS. THEREFORE...THE BEST POPS WILL BE CARRIED OVER THE
HIGHER TERRAIN SUNDAY AFTERNOON...WITH ONLY TOKEN LOW/SLIGHT CHANCES
IN THE PIEDMONT. TEMPS START OUT SLIGHTLY BELOW NORMAL SATURDAY WITH
PERSISTENT CONSIDERABLE CLOUD COVER AND EAST/SOUTHEAST FLOW.
HOWEVER...MAXES SHOULD CLIMB TO NEAR NORMAL LEVELS BY SUNDAY AS THE
AIR MASS BEGINS TO DRY OUT SOME.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AT 120 PM THURSDAY...A PRETTY TYPICAL MID-SUMMER PATTERN WILL BE
FEATURED EARLY NEXT WEEK AS THE WESTWARD EXTENT OF BERMUDA HIPRES
LINGERS ATOP THE SE CONUS AND LEE/PIEDMONT SFC TROUGHING DEVELOPS.
EXPECTED SENSIBLE WX FOR MONDAY AND TUESDAY WILL FEATURE MAX TEMPS
AROUND CLIMO AND DIURNAL SLIGHT AND/OR SMALL TSTM PROBABILITIES. THE
OP AND ENS MEAN ECMWF IS ADVERTISING DEVELOPING ERN CONUS L/WV
TROUGH FOR THE LATTER HALF OF THE PERIOD. BASED ON THIS AND THE
PERCEIVED INCREASE IN DEEP CONVECTIVE ACTIVITY SAID THOUGH WILL
HAVE...WILL NUDGE POPS UPWARD WEDNESDAY AND THURSDAY TO A MORE SOLID
DAILY CHANCE AND KEEP TEMPERATURES WITHIN A FEW DEGREES OF NORMAL.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
AT KCLT...THE AIRFIELD REMAINS DOMINATED BY WEAK CAD LIKE
CONDITIONS...HOWEVER THE LATEST LAPS ANALYSIS SHOWS A HIGHER
INSTABILITY GRADIENT NOT FAR TO THE SE. STILL THINK IT WILL TAKE
SOME TIME FOR THE INSTABILITY TO IMPROVE WITH ANY MINOR BREAKS IN
THE CLOUDS...AND THE HRRR DELAYS CONVECTION IN THE IMMEDIATE AREA
UNTIL 22Z. WILL THUS FEATURE TEMPO TSRA 21Z TO 01Z WITH SLIGHTLY
SLOWER ONSET. CONDITIONS SHOULD REMAIN MVFR WITH A RETURN TO IFR
OVERNIGHT. CLOUDS SHOULD LIFT AND SCATTER TO MVFR CIRCA 14Z TO 15Z
FRIDAY...WITH ANY NEW CONVECTION LIKELY HOLDING OFF UNTIL AFTER THE
CURRENT PERIOD. EXPECT MAINLY LIGHT NE TO ENE FLOW...BECOMING LIGHT
ESE LATE IN THE PERIOD.
ELSEWHERE...MOIST UPGLIDE WILL CONTINUE ACROSS THE MOUNTAINS...WHILE
A WEDGE LIKE CONFIGURATION PERSISTS OVER THE FOOTHILL TAF SITES.
THIS SHOULD MEAN SHOWERS FOR KAVL AND KHKY FOR THE BULK OF THE
PERIOD...WITH MORE SCATTERED SHOWERS AND VICINITY THUNDER FOR THE
UPSTATE TAF SITES WHERE BREAKS IN THE LOW OVERCAST MAY DEVELOP THIS
AFTN AND EVENING. CIGS SHOULD REMAIN MVFR ON AVERAGE
THROUGHOUT...WITH A RETURN TO IFR OVERNIGHT...AND LOW IFR POSSIBLE
AT TIMES TOWARD DAYBREAK. LOW CLOUDS WILL STEADILY LIFT AND SCATTER
THROUGH THE MORNING HOURS...WITH UPGLIDE/UPSLOPE SHOWERS HOLDING ON
THE LONGEST AT KAVL TO KHKY. EXPECT PERSISTENT E TO NE FLOW AT THE
FOOTHILL SITES AND LIGHT SE AT KAVL THROUGH THE PERIOD.
OUTLOOK...RETURNING ATLANTIC HIGH PRESSURE WILL MEAN MORE OF A
DIURNAL NATURE TO ANY SHOWERS AND THUNDERSTORMS FRIDAY AFTERNOON
THROUGH NEXT TUESDAY. THE BEST TSTM CHANCES WILL BE OVER THE
MOUNTAINS EACH DAY...WITH MORNING LOW CLOUDS AND FOG POSSIBLE EACH
MORNING THROUGHOUT.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...CSH
NEAR TERM...HG
SHORT TERM...JDL
LONG TERM...CSH
AVIATION...HG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
206 PM EDT THU JUL 12 2012
.SYNOPSIS...
A WEAK BUT MOIST AREA OF HIGH PRESSURE WILL REMAIN NOSED INTO THE
REGION THE NEXT FEW DAYS. BERMUDA HIGH PRESSURE WILL THEN BUILD IN
LATER THIS WEEKEND AND LINGER INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 1245 PM...WATER VAPOR IMAGERY SHOWED AN ELONGATED TROUGH AXIS
STRETCHED ALONG THE MS RIVER VALLEY. WEAK WAVES AHEAD OF THIS
FEATURE CONTINUE TO RIPPLE NE THROUGH ERN TN...BRUSHING EXTREME WRN
NC AS WELL. FARTHER EAST...WEAK COLD AIR DAMMING REMAINS IN PLACE
EAST OF THE MOUNTAINS...AND CLOUDS THROUGHOUT THE AREA HAVE BEEN
SLOW TO LIFT AND EVEN SLOWER TO SCATTER IN THE MOIST PROFILES WITH
WEAK UPGLIDE APPARENT. SFC BASED CAPE ON THE LATEST LAPS ANALYSIS
SHOWS AROUND 1000 J/KG ALONG THE SE FRINGE OF THE AREA. THESE VALUES
WILL RISE ALONG THE PERIPHERY OF THE WEDGE...AND VALUES OF 500 TO
1000 J/KG ARE LIKELY WITHIN THE SHALLOW WEDGE LAYER WHERE BREAKS
DEVELOP. ALTHOUGH THE MORNING RAOB AND CURRENT LAPS SOUNDINGS
EXHIBIT ABUNDANT MOISTURE...LAPSE RATES ARE WEAK...WINDS ALOFT ARE
FAIRLY LIGHT...SO SEVERE TSTM POTENTIAL IS QUITE LIMITED. WITH
PRECIPITABLE WATER VALUES RANGING FROM 1.6 INCHES IN THE MTNS TO
NEARLY 2 INCHES NEAR CLT...THE LIGHT STEERING FLOW MAY LEAD TO
POCKETS OF HEAVY RAINFALL WHERE RATES ARE HIGHEST AND ANY DEGREE OF
TRAINING OR UPSLOPE ANCHORING DEVELOPS. WILL KEEP THE BEST
AFTN/EVENING POPS FOCUSED ON THE MTNS CLOSER TO THE UPPER FORCING
AND WHERE SE TO S UPSLOPE FLOW IS BEST. WILL KEEP THE BEST TSTM
CHANCES ALONG THE SE FRINGE IN THE HIGHEST INSTABILITY. POPS MAY
THEN FOCUS ON THE ERN ESCARPMENT OVERNIGHT AS INSTABILITY WANES BUT
UPSLOPE CONTINUES.
850 MB WARM ADVECTION AND LOW LEVEL UPSLOPE FLOW WILL PERSIST ACROSS
THE SRN APPALACHIANS AND VICINITY THROUGH FRIDAY. HOWEVER...SLIGHTLY
LESS MOISTURE IS EVIDENT IN MODEL PROFILES ON FRI COMPARED TO TODAY
AS AN ATLANTIC RIDGE BUILDS WESTWARD. THIS SHOULD ALLOW CLOUDS TO
LIFT AND SCATTER A BIT MORE QUICKLY...LEADING TO WARMER MAXES...AND
INSTABILITY BUBBLING TO 1500 TO 2000 J/KG CAPE. WILL WARM MAX TEMPS
AT LEAST A CATEGORY OVER TODAY AND FEATURE LIKELY WEST TO SOLID CHC
EAST POPS...WITH MORE OF A THUNDER MENTION.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
AT 3 AM EDT THURSDAY...AN UPPER TROUGH WILL WEAKEN OVER THE MS RIVER
VALLEY ON FRIDAY AND SATURDAY...WHILE AN UPPER RIDGE OVER THE
ATLANTIC BUILDS WEST OVER THE CAROLINAS AND GA. A WARM FRONT WILL
MOVE SLOWLY NORTH OVER OUR AREA ON FRIDAY AS A SURFACE WAVE TO THE
WEST LIFTS NORTH THROUGH THE MS RIVER VALLEY. THE FRONT APPEARS TO
LEAVE OUR AREA ON SATURDAY. PRECIPITATION WILL FOCUS ALONG THIS
BOUNDARY AS SOUTHERLY LOW LEVEL ISENTROPIC UPGLIDE IS PRESENT. IN
THE WAKE OF THE FRONT...A MOIST SOUTHEASTERLY UPSLOPE FLOW WILL
MAXIMIZE PRECIPITATION ALONG THE BLUE RIDGE ESCARPMENT. ALTHOUGH
THERE WILL BE A LACK OF UPPER LEVEL FORCING EITHER DAY...MANY
PORTIONS OF THE AREA WILL BE PRIMED FOR FLOODING FOLLOWING SEVERAL
DAYS OF RAINFALL. MAXIMUM TEMPERATURES WILL REMAIN BELOW NORMAL...
BUT WITH A WARMING TREND AS HEIGHTS RISE ALOFT. MINIMUM TEMPERATURES
WILL BE NEAR OF SLIGHTLY ABOVE NORMAL IN A MOIST AIR MASS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AT 120 PM THURSDAY...A PRETTY TYPICAL MID-SUMMER PATTERN WILL BE
FEATURED EARLY NEXT WEEK AS THE WESTWARD EXTENT OF BERMUDA HIPRES
LINGERS ATOP THE SE CONUS AND LEE/PIEDMONT SFC TROUGHING DEVELOPS.
EXPECTED SENSIBLE WX FOR MONDAY AND TUESDAY WILL FEATURE MAX TEMPS
AROUND CLIMO AND DIURNAL SLIGHT AND/OR SMALL TSTM PROBABILITIES. THE
OP AND ENS MEAN ECMWF IS ADVERTISING DEVELOPING ERN CONUS L/WV
TROUGH FOR THE LATTER HALF OF THE PERIOD. BASED ON THIS AND THE
PERCEIVED INCREASE IN DEEP CONVECTIVE ACTIVITY SAID THOUGH WILL
HAVE...WILL NUDGE POPS UPWARD WEDNESDAY AND THURSDAY TO A MORE SOLID
DAILY CHANCE AND KEEP TEMPERATURES WITHIN A FEW DEGREES OF NORMAL.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AT KCLT...THE AIRFIELD REMAINS DOMINATED BY WEAK CAD LIKE
CONDITIONS...HOWEVER THE LATEST LAPS ANALYSIS SHOWS A HIGHER
INSTABILITY GRADIENT NOT FAR TO THE SE. STILL THINK IT WILL TAKE
SOME TIME FOR THE INSTABILITY TO IMPROVE WITH ANY MINOR BREAKS IN
THE CLOUDS...AND THE HRRR DELAYS CONVECTION IN THE IMMEDIATE AREA
UNTIL 22Z. WILL THUS FEATURE TEMPO TSRA 21Z TO 01Z WITH SLIGHTLY
SLOWER ONSET. CONDITIONS SHOULD REMAIN MVFR WITH A RETURN TO IFR
OVERNIGHT. CLOUDS SHOULD LIFT AND SCATTER TO MVFR CIRCA 14Z TO 15Z
FRIDAY...WITH ANY NEW CONVECTION LIKELY HOLDING OFF UNTIL AFTER THE
CURRENT PERIOD. EXPECT MAINLY LIGHT NE TO ENE FLOW...BECOMING LIGHT
ESE LATE IN THE PERIOD.
ELSEWHERE...MOIST UPGLIDE WILL CONTINUE ACROSS THE MOUNTAINS...WHILE
A WEDGE LIKE CONFIGURATION PERSISTS OVER THE FOOTHILL TAF SITES.
THIS SHOULD MEAN SHOWERS FOR KAVL AND KHKY FOR THE BULK OF THE
PERIOD...WITH MORE SCATTERED SHOWERS AND VICINITY THUNDER FOR THE
UPSTATE TAF SITES WHERE BREAKS IN THE LOW OVERCAST MAY DEVELOP THIS
AFTN AND EVENING. CIGS SHOULD REMAIN MVFR ON AVERAGE
THROUGHOUT...WITH A RETURN TO IFR OVERNIGHT...AND LOW IFR POSSIBLE
AT TIMES TOWARD DAYBREAK. LOW CLOUDS WILL STEADILY LIFT AND SCATTER
THROUGH THE MORNING HOURS...WITH UPGLIDE/UPSLOPE SHOWERS HOLDING ON
THE LONGEST AT KAVL TO KHKY. EXPECT PERSISTENT E TO NE FLOW AT THE
FOOTHILL SITES AND LIGHT SE AT KAVL THROUGH THE PERIOD.
OUTLOOK...RETURNING ATLANTIC HIGH PRESSURE WILL MEAN MORE OF A
DIURNAL NATURE TO ANY SHOWERS AND THUNDERSTORMS FRIDAY AFTERNOON
THROUGH NEXT TUESDAY. THE BEST TSTM CHANCES WILL BE OVER THE
MOUNTAINS EACH DAY...WITH MORNING LOW CLOUDS AND FOG POSSIBLE EACH
MORNING THROUGHOUT.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...CSH
NEAR TERM...HG
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...HG
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
911 PM CDT FRI JUL 13 2012
.UPDATE...BAND OF MOSTLY CLEAR SKIES OVER MIDDLE TN THIS EVENING,
BETWEEN I-65 AND THE CUMBERLAND PLATEAU, IS PROBABLY THE MOST
EXTENSIVE AREA OF DECREASED CLOUDINESS THAT WE`VE SEEN IN THE LAST
2 TO 4 DAYS. THIS BAND COINCIDES WITH AN AREA OF DECREASED
1000-500MB MEAN RH, WHICH IS EXPECTED TO MIGRATE SLOWLY TO THE
NORTHWEST OVERNIGHT AND REMAIN, FOR THE MOST PART, REMAIN PRECIP-
FREE. THE BEST CHANCE FOR SHOWERS AND THUNDERSTORMS WILL BE OVER
THE EXTREME NORTHWEST AND SOUTHERN AND WESTERN AREAS, WHERE
REGIONAL RADAR LOOPS SHOW EITHER ONGOING OR APPROACHING SHOWERS.
LATEST WRF, HRR AND RUC MODEL SOLUTIONS APPEAR TO AGREE WITH THIS
GENERAL IDEA
WILL LOWER POPS TO 20% IN THE BAND OF DECREASED MEAN RH (INCLUDING
THE NASHVILLE AREA), AND ADD THE POSSIBILITY FOR LATE NIGHT PATCHY FOG
(ESPECIALLY IN AREAS WHERE CLOUDS REMAIN THINNEST THE LONGEST).
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
19
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1037 AM CDT THU JUL 12 2012
.UPDATE...ADJUSTED POPS IN THE NW A TAD DOWNWARD...OTHERWISE
NO OTHER CHANGES. FRONT TO THE SOUTH WILL GRADUALLY DISSIPATE AND
POPS WILL DECLINE LATE TOMORROW AND WILL GO BACK TO A MORE DIURNAL
CONVECTIVE SITUATION WITH ACTIVITY MAINLY IN THE AFTERNOON AND EVENING.
&&
.PREV DISCUSSION... /ISSUED 621 AM CDT THU JUL 12 2012/
UPDATE...FOR 12Z AVIATION FORECAST
AVIATION...
POOR FLYING WEATHER ACROSS THE MID STATE NEXT 24 HOURS AS WIDESPREAD
AREA OF RAIN WILL KEEP CEILINGS AND VSBYS LOW.
A STATIONARY FRONT COUPLED WITH AN INVERTED TROUGH OF LOW PRESSURE
IS DRAPED WEST TO EAST ACROSS MIDDLE TENNESSEE THIS MORNING AND IS
PROGGED TO REMAIN IN SITU THROUGH TODAY. AT THE UPPER LEVEL (250
MILLIBARS) THERE IS AN ANTICYCLONICALLY CURVED JET SPRAWLED ACROSS
THE OHIO VALLEY AND NORTHERN PART OF THE TENNESSEE VALLEY.
STREAMLINE ANALYSIS SHOWS DIVERGENCE IN THE RIGHT REAR QUADRANT OF
THE JET AS WOULD BE EXPECTED WHICH MEANS PLENTY OF LIFT ACROSS THE
MID STATE FOR THE NEXT 24 HOURS. RAIN HAS ALREADY SPREAD NORTHWARD
IN THE OVERNIGHT HOURS AND WILL TRY AND OVERSPREAD ALL OF MIDDLE
TENNESSEE DURING THE DAY AND CONTINUE INTO TONIGHT. EXPECT THERE
WILL BE PERIODS OF HEAVY RAINFALL. AS FOR THUNDER...DID NOT INCLUDE
IN TERMINAL FORECASTS BUT EXPECT THERE WILL BE SOME EMBEDDED
THUNDERSTORMS ASSOCIATED WITH THE HEAVIER DOWNPOURS BUT THEY COULD
OCCUR AT ANYTIME AND ANY PLACE WITH THIS TYPE OF SETUP.
BOYD
PREV DISCUSSION... /ISSUED 334 AM CDT THU JUL 12 2012/
SHORT TERM...
WATER VAPOR IMAGERY THIS MORNING SHOWS A 250 MB TROUGH AXIS
DIGGING SOUTHEASTWARD ACROSS ARKANSAS...WITH SUBSTANTIAL MOISTURE
ADVECTION TO THE EAST OVER THE LOWER MISSISSIPPI AND TENNESSEE
VALLEYS. RADAR IMAGERY IN OUR NECK OF THE WOODS SHOWS AN AREA OF
LIGHT TO MODERATE RAIN OVER SOUTHERN ZONES EXPANDING NORTHWARD
ACROSS THE MID STATE...WITH ADDITIONAL SHOWERS DEVELOPING ACROSS
NORTHERN MISSISSIPPI. HPC SURFACE ANALYSIS INDICATES THE WEAK
FRONTAL BOUNDARY IS NOW LOCATED OVER SOUTHERN ZONES...WITH
TEMPERATURES AND DEWPOINTS IN THE 60S AND 70S AREAWIDE.
LATEST GLOBAL...SHORT TERM...AND HIGH RESOLUTION GUIDANCE
INCLUDING WRF AND HRRR MODELS INDICATES CURRENT AREA OF RAIN OVER
SOUTHERN ZONES WILL CONTINUE TO EXPAND NORTHWARD THROUGHOUT THE
DAY WITH ADDITIONAL SHOWERS AND THUNDERSTORMS FORMING AS WELL.
THIS APPEARS TO BE IN RESPONSE TO INCREASING LIFT AHEAD OF THE H25
TROUGH AXIS TO OUR WEST AND STRENGTHENING WAA OVER THE CWA AS
WEAK FRONT OVER SOUTHERN ZONES SLOWLY LIFTS NORTHWARD. THUS WILL
KEEP CATEGORICAL POPS GOING FOR TODAY WITH OFF AND ON SHOWERS AND
STORMS EXPECTED...AND HAVE LOWEST POPS IN THE NORTHWEST AND
HIGHEST IN THE SOUTHEAST. MUCH OF THE PLATEAU REGION WILL LIKELY
SEE RAIN ALL DAY LONG. WITH EXPECTED PRECIPITATION AND WIDESPREAD
CLOUD COVER...LITTLE DIURNAL RISE IN TEMPS IS ANTICIPATED TODAY
WITH HIGHS IN THE 70S AND LOWER 80S. AS FRONTAL BOUNDARY CONTINUE
TO LIFT NORTHWARD TONIGHT INTO TOMORROW...WILL KEEP LIKELY POPS
IN THE FORECAST BUT COVERAGE IS EXPECTED TO BE LESS THAN WE WILL
SEE ACROSS THE AREA TODAY.
GUIDANCE HAS BEEN TOO AGGRESSIVE AND OPTIMISTIC ON TIMING AND
INTENSITY OF CONVECTION YESTERDAY INTO EARLY THIS MORNING...AND
APPEARS HEAVY RAINFALL AND POSSIBLE FLOOD THREATS ARE LESSENING.
HPC HAS ACCORDINGLY LOWERED TOTAL RAINFALL FOR TODAY INTO FRIDAY
DOWN TO 1 TO 2 INCHES WITH SOME LOCALLY HIGHER AMOUNTS...BUT THIS
SHOULD BE EASILY HANDLED BY THE SOIL WITH THE ONGOING DROUGHT
CONDITIONS. THEREFORE...ALTHOUGH WE ARE EXPECTING WIDESPREAD
PRECIPITATION TODAY INTO TOMORROW...WILL NOT REISSUE HEAVY
RAINFALL SPS AT THIS TIME. SOME LOCALIZED FLOODING IS STILL NOT
OUT OF THE QUESTION WHERE THE HEAVIEST THUNDERSTORMS SET UP SHOP
AND WILL CONTINUE TO CLOSELY MONITOR THE SITUATION.
LONG TERM...
OVERALL PATTERN FOR THE REST OF THE FORECAST PERIOD APPEARS
SIMILAR TO PREVIOUS FORECASTS...WITH CWA REMAINING ON THE WEST
SIDE OF A GRADUALLY STRENGTHENING BERMUDA RIDGE OVER THE WESTERN
ATLANTIC AND EAST OF A PERSISTENT BUT WEAKENING TROUGH ALONG THE
MISSISSIPPI RIVER. A HIGHLY MOIST AIRMASS WILL ALSO REMAIN IN
PLACE THROUGHOUT THE FORECAST PERIOD WITH GFS INDICATING PWATS
WILL HOVER AROUND THE 2 INCH MARK. THIS PATTERN WILL ALLOW FOR
CONTINUED DAILY BUT MORE DIURNAL POPS...WITH A GRADUAL DECREASE
IN PRECIP CHANCES WHILE TEMPS INCREASE TO NEAR/ABOVE NORMAL
LEVELS. HAVE KEPT POPS/TEMPS UNDER BUT NOT FAR FROM MEX MOS
NUMBERS.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
18
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
928 AM EDT THU JUL 12 2012
.DISCUSSION...
A QUICK UPDATE TO THE POP...WX...AND QPF GRIDS TO ACCOUNT FOR ONGOING
SHOWERS ACROSS THE WESTERN HALF OF THE FORECAST AREA. ALSO AFTER
LOOKING AT THE HRRR AND 06Z NAM DECIDED TO ADJUST POPS LOWER IN
SOUTHWEST NC. TEMPERATURES LOOK REASONABLE AND NO ADJUSTMENTS WERE
MADE. BENEFICIAL RAINS WILL PERSIST FOR THE NEXT SEVERAL HOURS
ACROSS THE PLATEAU.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 80 69 87 71 90 / 100 70 70 40 50
KNOXVILLE MCGHEE TYSON AIRPORT, TN 79 68 85 70 89 / 90 80 70 40 50
OAK RIDGE, TN 78 68 84 70 89 / 100 80 70 40 50
TRI CITIES AIRPORT, TN 76 67 83 66 87 / 100 80 70 30 50
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
AC
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
621 AM CDT THU JUL 12 2012
.UPDATE...FOR 12Z AVIATION FORECAST
&&
.AVIATION...
POOR FLYING WEATHER ACROSS THE MID STATE NEXT 24 HOURS AS WIDESPREAD
AREA OF RAIN WILL KEEP CEILINGS AND VSBYS LOW.
A STATIONARY FRONT COUPLED WITH AN INVERTED TROUGH OF LOW PRESSURE
IS DRAPED WEST TO EAST ACROSS MIDDLE TENNESSEE THIS MORNING AND IS
PROGGED TO REMAIN IN SITU THROUGH TODAY. AT THE UPPER LEVEL (250
MILLIBARS) THERE IS AN ANTICYCLONICALLY CURVED JET SPRAWLED ACROSS
THE OHIO VALLEY AND NORTHERN PART OF THE TENNESSEE VALLEY.
STREAMLINE ANALYSIS SHOWS DIVERGENCE IN THE RIGHT REAR QUADRANT OF
THE JET AS WOULD BE EXPECTED WHICH MEANS PLENTY OF LIFT ACROSS THE
MID STATE FOR THE NEXT 24 HOURS. RAIN HAS ALREADY SPREAD NORTHWARD
IN THE OVERNIGHT HOURS AND WILL TRY AND OVERSPREAD ALL OF MIDDLE
TENNESSEE DURING THE DAY AND CONTINUE INTO TONIGHT. EXPECT THERE
WILL BE PERIODS OF HEAVY RAINFALL. AS FOR THUNDER...DID NOT INCLUDE
IN TERMINAL FORECASTS BUT EXPECT THERE WILL BE SOME EMBEDDED
THUNDERSTORMS ASSOCIATED WITH THE HEAVIER DOWNPOURS BUT THEY COULD
OCCUR AT ANYTIME AND ANY PLACE WITH THIS TYPE OF SETUP.
BOYD
&&
.PREV DISCUSSION... /ISSUED 334 AM CDT THU JUL 12 2012/
SHORT TERM...
WATER VAPOR IMAGERY THIS MORNING SHOWS A 250 MB TROUGH AXIS
DIGGING SOUTHEASTWARD ACROSS ARKANSAS...WITH SUBSTANTIAL MOISTURE
ADVECTION TO THE EAST OVER THE LOWER MISSISSIPPI AND TENNESSEE
VALLEYS. RADAR IMAGERY IN OUR NECK OF THE WOODS SHOWS AN AREA OF
LIGHT TO MODERATE RAIN OVER SOUTHERN ZONES EXPANDING NORTHWARD
ACROSS THE MID STATE...WITH ADDITIONAL SHOWERS DEVELOPING ACROSS
NORTHERN MISSISSIPPI. HPC SURFACE ANALYSIS INDICATES THE WEAK
FRONTAL BOUNDARY IS NOW LOCATED OVER SOUTHERN ZONES...WITH
TEMPERATURES AND DEWPOINTS IN THE 60S AND 70S AREAWIDE.
LATEST GLOBAL...SHORT TERM...AND HIGH RESOLUTION GUIDANCE
INCLUDING WRF AND HRRR MODELS INDICATES CURRENT AREA OF RAIN OVER
SOUTHERN ZONES WILL CONTINUE TO EXPAND NORTHWARD THROUGHOUT THE
DAY WITH ADDITIONAL SHOWERS AND THUNDERSTORMS FORMING AS WELL.
THIS APPEARS TO BE IN RESPONSE TO INCREASING LIFT AHEAD OF THE H25
TROUGH AXIS TO OUR WEST AND STRENGTHENING WAA OVER THE CWA AS
WEAK FRONT OVER SOUTHERN ZONES SLOWLY LIFTS NORTHWARD. THUS WILL
KEEP CATEGORICAL POPS GOING FOR TODAY WITH OFF AND ON SHOWERS AND
STORMS EXPECTED...AND HAVE LOWEST POPS IN THE NORTHWEST AND
HIGHEST IN THE SOUTHEAST. MUCH OF THE PLATEAU REGION WILL LIKELY
SEE RAIN ALL DAY LONG. WITH EXPECTED PRECIPITATION AND WIDESPREAD
CLOUD COVER...LITTLE DIURNAL RISE IN TEMPS IS ANTICIPATED TODAY
WITH HIGHS IN THE 70S AND LOWER 80S. AS FRONTAL BOUNDARY CONTINUE
TO LIFT NORTHWARD TONIGHT INTO TOMORROW...WILL KEEP LIKELY POPS
IN THE FORECAST BUT COVERAGE IS EXPECTED TO BE LESS THAN WE WILL
SEE ACROSS THE AREA TODAY.
GUIDANCE HAS BEEN TOO AGGRESSIVE AND OPTIMISTIC ON TIMING AND
INTENSITY OF CONVECTION YESTERDAY INTO EARLY THIS MORNING...AND
APPEARS HEAVY RAINFALL AND POSSIBLE FLOOD THREATS ARE LESSENING.
HPC HAS ACCORDINGLY LOWERED TOTAL RAINFALL FOR TODAY INTO FRIDAY
DOWN TO 1 TO 2 INCHES WITH SOME LOCALLY HIGHER AMOUNTS...BUT THIS
SHOULD BE EASILY HANDLED BY THE SOIL WITH THE ONGOING DROUGHT
CONDITIONS. THEREFORE...ALTHOUGH WE ARE EXPECTING WIDESPREAD
PRECIPITATION TODAY INTO TOMORROW...WILL NOT REISSUE HEAVY
RAINFALL SPS AT THIS TIME. SOME LOCALIZED FLOODING IS STILL NOT
OUT OF THE QUESTION WHERE THE HEAVIEST THUNDERSTORMS SET UP SHOP
AND WILL CONTINUE TO CLOSELY MONITOR THE SITUATION.
LONG TERM...
OVERALL PATTERN FOR THE REST OF THE FORECAST PERIOD APPEARS
SIMILAR TO PREVIOUS FORECASTS...WITH CWA REMAINING ON THE WEST
SIDE OF A GRADUALLY STRENGTHENING BERMUDA RIDGE OVER THE WESTERN
ATLANTIC AND EAST OF A PERSISTENT BUT WEAKENING TROUGH ALONG THE
MISSISSIPPI RIVER. A HIGHLY MOIST AIRMASS WILL ALSO REMAIN IN
PLACE THROUGHOUT THE FORECAST PERIOD WITH GFS INDICATING PWATS
WILL HOVER AROUND THE 2 INCH MARK. THIS PATTERN WILL ALLOW FOR
CONTINUED DAILY BUT MORE DIURNAL POPS...WITH A GRADUAL DECREASE
IN PRECIP CHANCES WHILE TEMPS INCREASE TO NEAR/ABOVE NORMAL
LEVELS. HAVE KEPT POPS/TEMPS UNDER BUT NOT FAR FROM MEX MOS
NUMBERS.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
334 AM CDT THU JUL 12 2012
.SHORT TERM...
WATER VAPOR IMAGERY THIS MORNING SHOWS A 250 MB TROUGH AXIS
DIGGING SOUTHEASTWARD ACROSS ARKANSAS...WITH SUBSTANTIAL MOISTURE
ADVECTION TO THE EAST OVER THE LOWER MISSISSIPPI AND TENNESSEE
VALLEYS. RADAR IMAGERY IN OUR NECK OF THE WOODS SHOWS AN AREA OF
LIGHT TO MODERATE RAIN OVER SOUTHERN ZONES EXPANDING NORTHWARD
ACROSS THE MID STATE...WITH ADDITIONAL SHOWERS DEVELOPING ACROSS
NORTHERN MISSISSIPPI. HPC SURFACE ANALYSIS INDICATES THE WEAK
FRONTAL BOUNDARY IS NOW LOCATED OVER SOUTHERN ZONES...WITH
TEMPERATURES AND DEWPOINTS IN THE 60S AND 70S AREAWIDE.
LATEST GLOBAL...SHORT TERM...AND HIGH RESOLUTION GUIDANCE
INCLUDING WRF AND HRRR MODELS INDICATES CURRENT AREA OF RAIN OVER
SOUTHERN ZONES WILL CONTINUE TO EXPAND NORTHWARD THROUGHOUT THE
DAY WITH ADDITIONAL SHOWERS AND THUNDERSTORMS FORMING AS WELL.
THIS APPEARS TO BE IN RESPONSE TO INCREASING LIFT AHEAD OF THE H25
TROUGH AXIS TO OUR WEST AND STRENGTHENING WAA OVER THE CWA AS
WEAK FRONT OVER SOUTHERN ZONES SLOWLY LIFTS NORTHWARD. THUS WILL
KEEP CATEGORICAL POPS GOING FOR TODAY WITH OFF AND ON SHOWERS AND
STORMS EXPECTED...AND HAVE LOWEST POPS IN THE NORTHWEST AND
HIGHEST IN THE SOUTHEAST. MUCH OF THE PLATEAU REGION WILL LIKELY
SEE RAIN ALL DAY LONG. WITH EXPECTED PRECIPITATION AND WIDESPREAD
CLOUD COVER...LITTLE DIURNAL RISE IN TEMPS IS ANTICIPATED TODAY
WITH HIGHS IN THE 70S AND LOWER 80S. AS FRONTAL BOUNDARY CONTINUE
TO LIFT NORTHWARD TONIGHT INTO TOMORROW...WILL KEEP LIKELY POPS
IN THE FORECAST BUT COVERAGE IS EXPECTED TO BE LESS THAN WE WILL
SEE ACROSS THE AREA TODAY.
GUIDANCE HAS BEEN TOO AGGRESSIVE AND OPTIMISTIC ON TIMING AND
INTENSITY OF CONVECTION YESTERDAY INTO EARLY THIS MORNING...AND
APPEARS HEAVY RAINFALL AND POSSIBLE FLOOD THREATS ARE LESSENING.
HPC HAS ACCORDINGLY LOWERED TOTAL RAINFALL FOR TODAY INTO FRIDAY
DOWN TO 1 TO 2 INCHES WITH SOME LOCALLY HIGHER AMOUNTS...BUT THIS
SHOULD BE EASILY HANDLED BY THE SOIL WITH THE ONGOING DROUGHT
CONDITIONS. THEREFORE...ALTHOUGH WE ARE EXPECTING WIDESPREAD
PRECIPITATION TODAY INTO TOMORROW...WILL NOT REISSUE HEAVY
RAINFALL SPS AT THIS TIME. SOME LOCALIZED FLOODING IS STILL NOT
OUT OF THE QUESTION WHERE THE HEAVIEST THUNDERSTORMS SET UP SHOP
AND WILL CONTINUE TO CLOSELY MONITOR THE SITUATION.
.LONG TERM...
OVERALL PATTERN FOR THE REST OF THE FORECAST PERIOD APPEARS
SIMILAR TO PREVIOUS FORECASTS...WITH CWA REMAINING ON THE WEST
SIDE OF A GRADUALLY STRENGTHENING BERMUDA RIDGE OVER THE WESTERN
ATLANTIC AND EAST OF A PERSISTENT BUT WEAKENING TROUGH ALONG THE
MISSISSIPPI RIVER. A HIGHLY MOIST AIRMASS WILL ALSO REMAIN IN
PLACE THROUGHOUT THE FORECAST PERIOD WITH GFS INDICATING PWATS
WILL HOVER AROUND THE 2 INCH MARK. THIS PATTERN WILL ALLOW FOR
CONTINUED DAILY BUT MORE DIURNAL POPS...WITH A GRADUAL DECREASE
IN PRECIP CHANCES WHILE TEMPS INCREASE TO NEAR/ABOVE NORMAL
LEVELS. HAVE KEPT POPS/TEMPS UNDER BUT NOT FAR FROM MEX MOS
NUMBERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 79 69 85 72 / 80 70 60 30
CLARKSVILLE 81 68 84 69 / 80 70 60 30
CROSSVILLE 75 66 80 68 / 90 70 60 30
COLUMBIA 79 69 86 71 / 80 70 60 30
LAWRENCEBURG 78 68 86 70 / 90 70 60 30
WAVERLY 80 68 84 69 / 80 70 60 30
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHAMBURGER
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
100 AM CDT THU JUL 12 2012
.UPDATE...
UPDATED FOR AVIATION.
&&
.PREV DISCUSSION... /ISSUED 945 PM CDT WED JUL 11 2012/
DISCUSSION...
A WEAK SURFACE BOUNDARY EXTENDS FROM SOUTHERN ARKANSAS ROUGHLY
ALONG THE TN/MS BORDER. MEANWHILE A WEAK UPPER LOW IS CENTERED
NEAR MEMPHIS. SIMILAR TO THE PAST COUPLE OF EVENINGS...CONVECTIVE
ACTIVITY HAS DIMINISHED SIGNIFICANTLY OVER THE PAST SEVERAL HOURS
WITH THE LOSS OF SURFACE HEATING. 12/18Z MODELS CONTINUE TO
INDICATE ADDITIONAL DEVELOPMENT OVERNIGHT BUT THE 23Z HRRR IS
FAIRLY QUIET OVERNIGHT WITH SOME ADDITIONAL DEVELOPMENT ACROSS NE
MS TOWARD MORNING. GIVEN CURRENT RADAR TRENDS THE HRRR SEEMS ON
THE RIGHT TRACK. WILL GO AHEAD AND CUT POPS 20 PERCENT...LEAVING
LIKELY POP ACROSS NE MS. WILL ALSO TRIM BACK THUNDER MENTION.
TEMPS AND SKY LOOK FINE.
SJM
PREV DISCUSSION... /ISSUED 318 PM CDT WED JUL 11 2012/
EXTENSIVE CLOUD COVER HAS REMAINED IN PLACE ACROSS THE MIDSOUTH
TODAY KEEPING TEMPERATURES IN THE 70S AND LOWER 80S AT MOST
LOCATIONS. THE EXCEPTION IS IN EAST ARKANSAS WHERE THINNER CLOUD
COVER HAS ALLOWED READINGS TO CLIMB INTO THE UPPER 80S. SHOWERS
WITH EMBEDDED THUNDERSTORMS ARE WIDESPREAD ACROSS NORTH
MISSISSIPPI AND DEVELOPING ACROSS MOST OF WEST TENNESSEE.
DEVELOPMENT IS EXPECTED TO CONTINUE THROUGH THE AFTERNOON HOURS. A
WEAK UPPER LEVEL LOW AND WEAK SURFACE REFLECTION WILL MOVE FROM
NORTH LOUISIANA ACROSS NORTH MISSISSIPPI DURING THE OVERNIGHT
HOURS. THESE FEATURES WILL ENHANCE PRECIPITATION
OVERNIGHT...ESPECIALLY ACROSS NORTH MISSISSIPPI. WE MAY END UP
WITH A FAIRLY TIGHT PRECIPITATION GRADIENT BETWEEN EAST ARKANSAS
AND NORTH MISSISSIPPI OVERNIGHT. HOWEVER AFTER SUNRISE...AS
TEMPERATURES WARM THE PRECIPITATION SHIELD SHOULD EXPAND RESULTING
IN A BETTER CHANCE OF RAIN IN THE WEST.
FRIDAY RAINFALL WILL BE LARGELY BE DIURNALLY DRIVEN AS A TROUGH
DIGS ALONG THE MISSISSIPPI VALLEY. THE TROUGH WILL GRADUALLY SHIFT
ACROSS THE MIDSOUTH SATURDAY INTO SUNDAY. DEPENDING ON ITS EXACT
ORIENTATION MUCH OF THE AREA COULD RECEIVE ADDITIONAL RAIN AND
THUNDERSTORMS...OR WE COULD SEE A SITUATION WHERE THE EASTERN
AREAS GET A NICE SOAKING RAIN WHILE FARTHER WEST IN EAST
ARKANSAS...WHERE RAIN IS MORE NEEDED...SHOWERS ARE LESS ABUNDANT.
EARLIER MODEL RUNS INDICATED A STRONGER COLD FRONT MOVING ACROSS
THE MIDSOUTH WITH THE TROUGH OVER THE WEEKEND. CURRENT GUIDANCE IS
NOT AS BULLISH WITH THIS SOLUTION...ACTUALLY KEEPING THE FRONT
WELL TO OUR NORTH. HOWEVER EVEN THE TROUGH ALOFT WITHOUT THE
SURFACE FRONT SHOULD KEEP RAIN CHANCES ABOVE CLIMATOLOGY.
TEMPERATURES WILL BEGIN TO TREND WARMER FRIDAY WITH NEAR NORMAL
READINGS EXPECTED SATURDAY...AND NEAR TO SLIGHTLY WARMER THAN
NORMAL READINGS EARLY NEXT WEEK.
&&
.AVIATION...
06Z TAFS
EXPECT PROGRESSIVELY LOWERING CIGS OVERNIGHT...SIMILAR TO 24 HOURS
AGO. IFR WAS NOTED AT TUP AT 06Z... AND WILL BE POSSIBLE AT MEM
TOWARD 10Z. AREAS SOUTH OF A MEM/MKL LINE REMAIN THE FAVORED AREA
FOR OVERNIGHT SHOWERS.
PWB
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 71 88 72 90 / 40 50 40 50
MKL 70 87 70 88 / 50 50 40 50
JBR 70 89 71 88 / 30 30 30 40
TUP 70 88 71 90 / 50 50 40 50
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
831 PM CDT FRI JUL 13 2012
.UPDATE...
WILL LET FLASH FLOOD WATCH EXPIRE AT 9PM THIS EVENING. SOME MINOR
SHORT TERM CHANGES FOR TEMPS..DEW POINTS...SKY COVER AND REDUCE
OVERNIGHT PCPN CHANCES.
&&
.DISCUSSION...
AS PER PAST FEW EVENINGS SHRA/TSRA ARE WINDING DOWN QUICKLY WITH
LOSS OF DAYTIME HEATING. SKY COVERAGE ALSO DECREASING. AREA 00Z
RAOBS STILL HAVE 1.9 TO NEAR 2.0 INCH PWAT VALUES SO THE
ATMOSPHERE REMAINS MOISTURE LADEN. 1000-700MB MEAN TROUGH DID SAG
SOUTHEASTWARD TODAY AS SUGGESTED BY LARGER SCALE GUIDANCE LAST
NIGHT. 18Z GFS AND 12Z ECM BEGIN TO RETREAT THE TROUGH TO THE
NORTHWEST OVER THE WEEKEND. ONE DIFFERENCE IS THAT NAM/GFS
FORECAST SOUNDINGS DO NOT LOOK NEARLY AS UNSTABLE IN THE OVERNIGHT
HOURS BUT BEGIN TO DEVELOPMENT ATTAINABLE CAPE BY MID TO LATE
MORNING. LATEST HRRR AND TX TECH WRF RUNS DO NOT FORECAST
EXPLOSIVE TSRA/HVY RAIN OVERNIGHT. HAVE REDUCED OVERNIGHT
PRECIPITATION CHANCES AND WILL ALLOW FF WATCH TO
EXPIRE ESPECIALLY GIVEN THE REDUCED CHANCE OF OVERNIGHT HVY RAINS
KEEPS A DECENTLY LONG NUMBER OF HOURS OF MOSTLY DRY WEATHER. NEXT
WHICH SHIFT MIGHT NEED TO ISSUE A NEW FF WATCH FOR PORTIONS OF THE
AREA..POSSIBLY MID-MORNING THROUGH THE AFTERNOON. NOT ENOUGH
CONFIDENCE AT THIS POINT TO PINPOINT AREAS FOR POSSIBLE WATCH
GIVEN NO NEWER LARGE SCALE 00Z MODEL GUIDANCE.
NEW ZONES AND PRODUCTS BY 9PM. 04
&&
.HYDROLOGY...
ALTHOUGH THE FLASH FLOOD WATCH HAS BEEN ALLOWED TO EXPIRE SEVERAL
CREEKS..RIVERS AND STREAMS ARE IN FLOOD STAGE OR VERY CLOSE.
PLEASE REFER TO RVSHGX AND FLSHGX PRODUCTS FOR FURTHER DETAILS.
THESE ARE ALSO AVAILABLE ON OUR WEB SITE. 04
&&
.PREV DISCUSSION... /ISSUED 633 PM CDT FRI JUL 13 2012/
AVIATION...
ACTIVITY QUICKLY DISSIPATING EARLY THIS EVENING WITH NO SHRA/TSRA NEAR
ANY TAF SITES. THE FORECAST PATTERN REMAINS THE SAME THE NEXT COUPLE
OF DAYS AS THE UPPER TROF LINGERS NEAR THE AREA. THE 00Z TAFS HAVE KEPT
VCSH/VCTS DURING THE DAYTIME HOURS TOMORROW UNDER GENERALLY VFR CONDITIONS.
42
PREV DISCUSSION... /ISSUED 340 PM CDT FRI JUL 13 2012/
DISCUSSION...
SCATTERED CONVECTION HAS SHIFTED WESTWARD THIS AFTERNOON WITH THE
HEAVIEST ACTIVITY LOCATED ACROSS WESTERN BRAZORIA COUNTY AND ALONG
A LINE FROM NEAR COLUMBUS NORTHWESTWARD TO BURNET. EXPECTING THAT
COVERAGE WILL CONTINUE TO DECREASE ACROSS THE REGION THROUGH THE
EVENING HOURS ALTHOUGH ANY REMAINING THUNDERSTORMS WILL BE CAPABLE
OF PRODUCING BRIEF HEAVY DOWNPOURS...GUSTY WINDS...AND FREQUENT
CLOUD TO GROUND LIGHTNING. THE FLASH FLOOD WATCH WILL REMAIN IN
EFFECT FOR MOST OF SOUTHEAST TEXAS THROUGH 9 PM THIS EVENING.
MAIN CONCERN FOR THIS FORECAST REMAINS THE POTENTIAL FOR
ADDITIONAL RAINFALL ACROSS THE REGION OVER THE WEEKEND. BOTH THE
ECMWF AND GFS RUNS FROM THIS MORNING BEGIN TO DRIFT THE UPPER
LEVEL WEAKNESS BACK TO THE WEST AND HAVE IT OVERHEAD BY LATE
SATURDAY. STILL THINK THAT SATURDAY WILL BE A RELATIVELY DRIER DAY
FOR MUCH OF THE REGION WITH THE HEAVIEST TOTALS MAINLY ACROSS OUR
EASTERN COUNTIES BUT WILL CARRY CHANCE POPS AREAWIDE THROUGH THE
AFTERNOON. WILL KEEP CHANCE POPS IN FOR SUNDAY AS WELL BUT THESE
MAY NEED TO BE RAISED AS THE TROUGH CONTINUES TO TRANSIT THE
REGION.
HEADING INTO THE EXTENDED...THE UPPER LEVEL WEAKNESS THAT HAS
PERSISTED ACROSS THE REGION WILL MOVE WELL WEST OF THE REGION AS
AN INVERTED TROUGH WITH THE UPPER LEVEL RIDGE BEGINNING TO
REESTABLISH ITSELF ACROSS THE CENTRAL PLAINS. THIS WILL HELP TO
LOWER OUR RAIN CHANCES THROUGH THE WEEK BUT WILL CONTINUE TO KEEP
SLIGHT CHANCE TO CHANCE POPS IN THE FORECAST AS HEIGHTS WILL
REMAIN LOW ENOUGH THAT WE COULD SEE A FEW SHOWERS AND
THUNDERSTORMS DEVELOP WITH DAYTIME HEATING EACH AFTERNOON. 38
MARINE...
NO SIGNIFICANT CHANGES TO CURRENT FCST TRENDS. A WEAK SURFACE TROUGH
WILL KEEP A LIGHT WINDS IN PLACE THROUGH THE WEEKEND. THE LINGERING
UPPER LEVEL TROF WILL ALSO KEEP SCATTERED STORMS IN THE FCST THROUGH
THE END OF THE WEEK. BRIEF GUSTY WINDS/ELEVATED SEAS ARE POSSIBLE IN
AND NEAR THE STRONGER STORMS. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 73 90 73 91 73 / 20 50 30 50 20
HOUSTON (IAH) 74 90 73 90 74 / 30 50 20 50 20
GALVESTON (GLS) 82 88 82 89 82 / 30 50 30 40 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...FLASH FLOOD WATCH UNTIL 9 PM CDT THIS EVENING FOR THE FOLLOWING
ZONES: AUSTIN...BRAZORIA...CHAMBERS...COLORADO...FORT
BEND...GALVESTON...HARRIS...JACKSON...LIBERTY...MATAGORDA...
MONTGOMERY...POLK...SAN JACINTO...WALLER...WHARTON.
GM...NONE.
&&
$$
DISCUSSION...04
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1211 PM CDT THU JUL 12 2012
.DISCUSSION...
SEE AVIATION DISCUSSION BELOW...
&&
.AVIATION...
A FAIRLY DECENT CUMULUS FIELD HAS DEVELOPED ACROSS THE AREA THIS
AFTERNOON. CANNOT RULE OUT AN ISOLATED SHOWER OR THUNDERSTORM THIS
AFTERNOON...BUT CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE IN THE
CURRENT TAF PACKAGE. LIGHT EAST WINDS THIS AFTERNOON...WILL
BECOME LIGHT AND VARIABLE OVERNIGHT. VFR CONDITIONS ARE EXPECTED
THROUGH THE NEXT 24 HOURS.
&&
.PREV DISCUSSION... /ISSUED 1135 AM CDT THU JUL 12 2012/
UPDATE...
TO UPDATE POPS
DISCUSSION...
VISIBLE SATELLITE INDICATES A FAIRLY GOOD CUMULUS FIELD DEVELOPING
ACROSS MUCH OF WEST CENTRAL TEXAS. LAST FEW RUNS OF THE HRRR HIGH
RESOLUTION MODEL INDICATES SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS DEVELOPING ACROSS MUCH OF THE AREA THIS AFTERNOON.
LITTLE CAP SHOULD ALLOW FOR A FEW SHOWERS TO DEVELOP...SO HAVE
INCREASED POPS TO SLIGHT CHANCE. COVERAGE SHOULD REMAIN FAIRLY
ISOLATED THIS AFTERNOON...WITH MOST AREAS REMAINING DRY.
PREV DISCUSSION... /ISSUED 920 AM CDT THU JUL 12 2012/
UPDATE...
TO REMOVE FOG FROM THE GRIDS
DISCUSSION...
FOG HAS DISSIPATED ACROSS OUR SOUTHERN COUNTIES THIS MORNING. SENT
OUT A QUICK UPDATE TO REMOVE FOG FROM THE WEATHER GRIDS.
OTHERWISE...NO OTHER CHANGES NEEDED AT THIS TIME.
PREV DISCUSSION... /ISSUED 619 AM CDT THU JUL 12 2012/
DISCUSSION...
LOOK FOR VFR CONDITIONS TO DOMINATE WEST CENTRAL TEXAS FOR THE
NEXT 24 HOURS. SEE AVIATION BELOW FOR DETAILS.
AVIATION...
EXPECT VFR CONDITIONS AND LIGHT WINDS TO DOMINATE WEST CENTRAL
TEXAS FOR THE NEXT 24 HOURS. CLEAR SKIES AND LIGHT WINDS HAVE
CREATED FAVORABLE CONDITIONS FOR PATCH LIGHT FOG ACROSS OUR
SOUTHEASTERN COUNTIES THIS MORNING...WHERE WE HAVE RECORDED THE
MOST RAINFALL OVER THE LAST SEVERAL DAYS. THUS...I DECIDED TO
INCLUDE TEMPO GROUPS FOR 5SM AND LIGHT FOG FOR A FEW HOURS THIS
MORNING. OTHERWISE...WEATHER NIL FOR ALL FIVE TERMINALS FOR THE
NEXT 24 HOURS.
HUBER
PREV DISCUSSION... /ISSUED 339 AM CDT THU JUL 12 2012/
SHORT TERM...
RAIN CHANCES FOR THE NEXT 24 HOURS DO NOT LOOK PROMISING. DRIER AIR
HAS MOVED INTO WEST CENTRAL TEXAS FROM THE NORTH...AS THE OLD
SURFACE FRONTAL BOUNDARY MOVED SOUTH. LATEST SURFACE ANALYSIS PLACES
THIS OLD SURFACE BOUNDARY JUST SOUTHEAST OF OUR COUNTIES...SOMEWHERE
ACROSS THE TEXAS HILL COUNTRY. THAT AREA WILL LIKELY BE THE FOCUS
FOR SHOWERS AND THUNDERSTORMS THIS AFTERNOON. THUS...I HAVE DECIDED
TO GO WITH 10 POPS ACROSS THE BOARD FOR THE NEXT 24 HOURS. WITH CALM
WINDS AND SURFACE DEWPOINT TEMPERATURES AROUND 70 ACROSS SOME OF OUR
SOUTHEASTERN COUNTIES...I DECIDED TO GO WITH PATCH FOG FOR A FEW
HOURS THERE THIS MORNING. OTHERWISE...WEATHER NIL ACROSS THE BOARD
FOR THE NEXT 24 HOURS. DECREASED CLOUDS TODAY WILL HELP PUSH
AFTERNOON HIGHS INTO MAINLY THE LOWER TO MID 90S RANGE. OVERNIGHT
TONIGHT...LOWS NEAR PERSISTENCE LOOK ON TRACK.
HUBER
LONG TERM...
UPPER LEVEL TROUGH EXTENDING FROM NE TEXAS INTO MISSOURI THIS
MORNING...IS INDICATED TO SLOW DOWN AND BECOME STATIONARY OVER
THE LOWER MISSISSIPPI VALLEY FRIDAY...THEN RETROGRADE SLOWLY
WESTWARD INTO EAST TEXAS THIS WEEKEND. CONFIDENCE LOW...BUT A FEW
SHOWERS AND THUNDERSTORMS POSSIBLE THIS WEEKEND...MAINLY OVER
EASTERN AND SOUTHERN ZONES OF WEST CENTRAL TEXAS. BOTH THE EC AND
GFS DEVELOP AN UPPER LOW OVER SOUTH TEXAS THE START OF NEXT
WEEK...PERHAPS AS AN EXTENSION OF THE UPPER TROUGH OVER EAST
TEXAS. WHILE THIS MAY BRING A FEW SHOWERS OVER THE THE I-10
CORRIDOR...CONFIDENCE IN ITS DEVELOPMENT REMAINS TOO LOW TO
INTRODUCE RAIN CHANCES. OTHERWISE...HIGHS CONTINUE 3 TO 5 DEGREES
ABOVE GFS MOS GUIDANCE... AND WILL INCREASE ACCORDINGLY.
04
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 71 97 69 95 71 / 10 10 10 10 10
SAN ANGELO 71 97 73 94 71 / 10 10 10 10 10
JUNCTION 71 94 71 93 71 / 10 10 10 10 20
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DANIELS
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1135 AM CDT THU JUL 12 2012
.UPDATE...
TO UPDATE POPS
&&
.DISCUSSION...
VISIBLE SATELLITE INDICATES A FAIRLY GOOD CUMULUS FIELD DEVELOPING
ACROSS MUCH OF WEST CENTRAL TEXAS. LAST FEW RUNS OF THE HRRR HIGH
RESOLUTION MODEL INDICATES SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS DEVELOPING ACROSS MUCH OF THE AREA THIS AFTERNOON.
LITTLE CAP SHOULD ALLOW FOR A FEW SHOWERS TO DEVELOP...SO HAVE
INCREASED POPS TO SLIGHT CHANCE. COVERAGE SHOULD REMAIN FAIRLY
ISOLATED THIS AFTERNOON...WITH MOST AREAS REMAINING DRY.
&&
.PREV DISCUSSION... /ISSUED 920 AM CDT THU JUL 12 2012/
UPDATE...
TO REMOVE FOG FROM THE GRIDS
DISCUSSION...
FOG HAS DISSIPATED ACROSS OUR SOUTHERN COUNTIES THIS MORNING. SENT
OUT A QUICK UPDATE TO REMOVE FOG FROM THE WEATHER GRIDS.
OTHERWISE...NO OTHER CHANGES NEEDED AT THIS TIME.
PREV DISCUSSION... /ISSUED 619 AM CDT THU JUL 12 2012/
DISCUSSION...
LOOK FOR VFR CONDITIONS TO DOMINATE WEST CENTRAL TEXAS FOR THE
NEXT 24 HOURS. SEE AVIATION BELOW FOR DETAILS.
AVIATION...
EXPECT VFR CONDITIONS AND LIGHT WINDS TO DOMINATE WEST CENTRAL
TEXAS FOR THE NEXT 24 HOURS. CLEAR SKIES AND LIGHT WINDS HAVE
CREATED FAVORABLE CONDITIONS FOR PATCH LIGHT FOG ACROSS OUR
SOUTHEASTERN COUNTIES THIS MORNING...WHERE WE HAVE RECORDED THE
MOST RAINFALL OVER THE LAST SEVERAL DAYS. THUS...I DECIDED TO
INCLUDE TEMPO GROUPS FOR 5SM AND LIGHT FOG FOR A FEW HOURS THIS
MORNING. OTHERWISE...WEATHER NIL FOR ALL FIVE TERMINALS FOR THE
NEXT 24 HOURS.
HUBER
PREV DISCUSSION... /ISSUED 339 AM CDT THU JUL 12 2012/
SHORT TERM...
RAIN CHANCES FOR THE NEXT 24 HOURS DO NOT LOOK PROMISING. DRIER AIR
HAS MOVED INTO WEST CENTRAL TEXAS FROM THE NORTH...AS THE OLD
SURFACE FRONTAL BOUNDARY MOVED SOUTH. LATEST SURFACE ANALYSIS PLACES
THIS OLD SURFACE BOUNDARY JUST SOUTHEAST OF OUR COUNTIES...SOMEWHERE
ACROSS THE TEXAS HILL COUNTRY. THAT AREA WILL LIKELY BE THE FOCUS
FOR SHOWERS AND THUNDERSTORMS THIS AFTERNOON. THUS...I HAVE DECIDED
TO GO WITH 10 POPS ACROSS THE BOARD FOR THE NEXT 24 HOURS. WITH CALM
WINDS AND SURFACE DEWPOINT TEMPERATURES AROUND 70 ACROSS SOME OF OUR
SOUTHEASTERN COUNTIES...I DECIDED TO GO WITH PATCH FOG FOR A FEW
HOURS THERE THIS MORNING. OTHERWISE...WEATHER NIL ACROSS THE BOARD
FOR THE NEXT 24 HOURS. DECREASED CLOUDS TODAY WILL HELP PUSH
AFTERNOON HIGHS INTO MAINLY THE LOWER TO MID 90S RANGE. OVERNIGHT
TONIGHT...LOWS NEAR PERSISTENCE LOOK ON TRACK.
HUBER
LONG TERM...
UPPER LEVEL TROUGH EXTENDING FROM NE TEXAS INTO MISSOURI THIS
MORNING...IS INDICATED TO SLOW DOWN AND BECOME STATIONARY OVER
THE LOWER MISSISSIPPI VALLEY FRIDAY...THEN RETROGRADE SLOWLY
WESTWARD INTO EAST TEXAS THIS WEEKEND. CONFIDENCE LOW...BUT A FEW
SHOWERS AND THUNDERSTORMS POSSIBLE THIS WEEKEND...MAINLY OVER
EASTERN AND SOUTHERN ZONES OF WEST CENTRAL TEXAS. BOTH THE EC AND
GFS DEVELOP AN UPPER LOW OVER SOUTH TEXAS THE START OF NEXT
WEEK...PERHAPS AS AN EXTENSION OF THE UPPER TROUGH OVER EAST
TEXAS. WHILE THIS MAY BRING A FEW SHOWERS OVER THE THE I-10
CORRIDOR...CONFIDENCE IN ITS DEVELOPMENT REMAINS TOO LOW TO
INTRODUCE RAIN CHANCES. OTHERWISE...HIGHS CONTINUE 3 TO 5 DEGREES
ABOVE GFS MOS GUIDANCE... AND WILL INCREASE ACCORDINGLY.
04
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 94 71 97 69 95 / 20 10 10 10 10
SAN ANGELO 94 71 97 73 94 / 20 10 10 10 10
JUNCTION 93 71 94 71 93 / 20 10 10 10 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DANIELS
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1149 PM CDT WED JUL 11 2012
.AVIATION...
MOST MODELS CONTINUE TO INDICATE ADDITIONAL SHRA DEVELOPING OVERNIGHT
AND THEN SHRA/TSRA DEVELOPMENT DURING THE DAY TOMORROW...SO PLAN ON
KEEPING VCSH AND VCTS THROUGH AROUND 00Z ON THE 06Z TAFS. THE EXACT
LOCATION AND AXIS OF DEVELOPING ACTIVITY REMAINS DIFFICULT TO
PINPOINT...SO AVIATION FORECASTER CONFIDENCE IS STILL LOW. EXPECT
TO SEE SOME MVFR/IFR CEILINGS AND VISIBILITIES IN/NEAR THE STORMS.
ALSO...WITH DECREASING CLOUDS TRYING TO EDGE INTO THE AREA FROM THE
NORTHWEST...COULD SEE SOME FOG DEVELOPMENT IN/AROUND THE CLL SITE.
42
&&
.PREV DISCUSSION... /ISSUED 904 PM CDT WED JUL 11 2012/
UPDATE...
MINOR UPDATES BELOW.
DISCUSSION...
CONVECTION HAS WOUND DOWN CONSIDERABLY THIS EVENING SIMILAR TO
YESTERDAY. IN THE VERY SHORT TERM THIS EVENING HAVE UPDATED GRIDS
AND ZONE WORDING FOR ONLY ISOLATED THUNDER...AFTER MIDNIGHT IS
ANOTHER STORY. EXPECT SHOWERS AND THUNDERSTORMS TO DEVELOP AGAIN
DURING THE OVERNIGHT HOURS PER THE PERSISTENT TREND. HRRR MODEL
GUIDANCE DID QUITE WELL LAST NIGHT WITH PLACEMENT OF TSRA ALONG
THE COAST. TONIGHT THE HRRR DEVELOPS STORMS FURTHER INLAND AS DOES
THE NEW 00Z NAM12. IF THIS SCENARIO HOLDS TRUE STORMS SHOULD FIRE
UP AROUND 07-08Z CLOSER TO METRO AREA THAN LAST NIGHT. STILL NOT
ENOUGH CONFIDENCE IN THAT SOLUTION TO REFINE THE SIZE OF THE FLASH
FLOOD WATCH AREA. AREA SOUNDINGS STILL HAVE EXTREMELY MOIST
ATMOSPHERE WITH 00Z KLCH PWAT OF 2.05 INCH AND KSHV 2.27 INCH.
BLENDED PWAT PRODUCT AGREES WITH SLIGHTLY HIGHER PWAT AIR POOLING
A LITTLE FURTHER NORTH IN CWA...BUT IT`S ALL HIGH. SATURATED
GROUNDS OVER MUCH OF THE CWA FROM RECENT RAINS...CONTINUATION OF
FLASH FLOOD WATCH IS PRUDENT DESPITE THIS TEMPORARY LULL.
FEW SMALL TEMP AND DEW POINT CHANGES AS A FEW INLAND AREAS RUNNING
COOLER THAN FORECAST. 04
PREV DISCUSSION... /ISSUED 353 PM CDT WED JUL 11 2012/
DISCUSSION...
SHOWERS AND THUNDERSTORMS SHOULD CONTINUE TO DEVELOP ACROSS THE
NORTH AND NORTHWEST 1/3 OF SOUTHEAST TEXAS THIS AFTERNOON AND
EVENING. THESE STORMS MAY PRODUCE SOME LOCALLY HEAVY RAINFALL WITH
RATES UP TO 2 INCHES PER HOUR. THIS ACTIVITY SHOULD EVENTUALLY
DISSIPATE WITH THE LOSS OF HEATING AND GIVE MUCH OF THE AREA A
BREAK FROM PRECIPITATION.
HOWEVER...EXPECT ANOTHER ROUND OF PRECIPITATION TO DEVELOP AFTER
MIDNIGHT AND TOWARD MORNING. IT IS NOT CLEAR EXACTLY WHERE THIS
RAIN WILL INITIATE - WHETHER IT BE ALONG THE COAST OR FURTHER
INLAND. SURFACE AND UPPER LEVEL CONDITIONS ARE FAVORABLE FOR BOTH
SCENARIOS WITH EXCELLENT UPPER DIFFLUENCE ALOFT AND GOOD SURFACE SPEED
CONVERGENCE FCST ALONG THE COAST. THIS COMBINED WITH 2.2-2.4"
PW`S.
PRECIPITATION WILL EXPAND IN COVERAGE THROUGH THE MORNING HOURS
THURSDAY...RESIDENTS SHOULD BE PREPARED FOR SOME TRAINING LOCALLY
HEAVY RAINFALL THAT MAY PRODUCE RIVER...CREEK AND STREET FLOODING.
THE FLASH FLASH FLOOD WATCH HAS BEEN EXTENDED THROUGH 4PM THURS.
SEE THAT PRODUCT FOR MORE SHORT TERM WX DETAILS. POTENTIALLY
DANGEROUS SITUATION IF THE HEAVIEST RAIN AFFECTS AREAS THAT HAVE
BEEN GETTING HIT HARD IN THE PAST 18 HOURS.
TROF AXIS/WEAKNESS LOOKS TO MEANDER AROUND THRU THE WEEKEND.
THOUGH MOISTURE LEVELS MIGHT DIMINISH A TOUCH THEY SHOULD STILL
HOVER AROUND 2" INTO EARLY NEXT WEEK. FEEL THAT WE SHOULD CONTINUE
TO SEE DECENT COVERAGE - PROBABLY BECOMING MORE DIURNAL IN NATURE
- INTO NEXT WEEK SO NUDGE AFTN POPS UPWARDS. MODEL TRENDS HAS
BEEN FOR DECREASING POPS ABOUT T+48 WHICH STILL HASN`T HAPPENED...SO
GENERAL PERSISTENCE IS PROBABLY THE WAY TO GO UNTIL SOMETHING
CHANGES. 47
MARINE...
NOT A LOT OF CHANGES TO THE GOING FCST TRENDS. A WEAK SURFACE TROUGH
WILL KEEP A LIGHT WIND REGIME IN PLACE THROUGH THE WEEKEND. AN UPPER
LEVEL TROUGH WILL ALSO KEEP SCATTERED STORMS IN THE FCST THROUGH THE
END OF THE WEEK. BRIEF GUSTY WINDS AND ELEVATED SEAS ARE POSSIBLE IN
AND NEAR ANY THUNDERSTORM ACTIVITY. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 73 88 73 89 73 / 70 60 40 50 30
HOUSTON (IAH) 74 86 74 89 73 / 70 70 40 50 40
GALVESTON (GLS) 78 85 78 88 78 / 70 70 40 50 50
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...FLASH FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR THE FOLLOWING
ZONES: AUSTIN...BRAZORIA...BRAZOS...BURLESON...CHAMBERS...
COLORADO...FORT BEND...GALVESTON...GRIMES...HARRIS...
JACKSON...LIBERTY...MADISON...MATAGORDA...MONTGOMERY...
POLK...SAN JACINTO...WALKER...WALLER...WASHINGTON...WHARTON.
GM...NONE.
&&
$$
DISCUSSION...04
AVIATION/MARINE...42
AREA FORECAST DISCUSSION
NWS SPOKANE WA
439 PM PDT Fri Jul 13 2012
.SYNOPSIS...
Warm and increasingly humid conditions are expected over the
Inland Northwest through the weekend as a slow-moving upper level
low tracks through the region. this air mass will contribute to a
chance of thunderstorms on both Saturday and Sunday. Some of the
storms could produce locally heavy rains and possibly some large
hail. the low will track out of the region late Sunday night or
Monday followed by Seasonably with slight chances for thunderstorms.
&&
.DISCUSSION...
Tonight: Upper level low pressure system is spinning along coastal
WA this afternoon. This is bring up monsoonal moisture from the
Desert Southwest. This moisture is expected to push into our
southeastern zones tonight. However, the more immediate threat
will be surface based convection that is expected to develop
during the late afternoon hours. First we need to break through
the cap to release what is potentially a considerable amount of
convective potential energy (CAPE). The strongest CAPE values of
up to 2000 J/KG is located across the northern mountains with
around 20-40 J/KG of convective inhibition (CIN) that has capped
the atmosphere. South of a line from southern Kootenai County to
Moses Lake will be significantly more CIN that will likely not get
broken through the evening hours. The HRRR model shows Some
convection begin to develop during the afternoon or early evening
hours along and north of a line from Coeur d`Alene, Wilbur and to
Moses Lake. This convection will move northward with potential
risks including hail (potentially some sever in size), gusty
outflow winds and cloud to ground lightning strikes.
During the overnight hours, the monsoonal moisture moving
northward will being to spread across our southeastern zones.
Upper level laps rates will become increasingly more unstable
through the night into tomorrow morning north and westward.
Water vapor satellite imagery shows an upper level wave at the
base of the low pressure system, currently across southwestern WA
into western OR. This short wave will continue to rotate around
the low in a counter-clockwise fashion where it is expected to
swing around into southeast WA by the early morning hours tomorrow
morning. This short wave will provide the lift that will kick off
more widespread thunderstorm activity. /SVH
Saturday...the closed upper low currently over NW WA will remain fixed
over the region at least through Saturday afternoon. Models are in
very good agreement that the low will dip slowly SE during the
next 24 hrs...centering itself near The Dalles. As the low moves
toward this area...it will begin to pool of monsoonal moisture
currently over southern Idaho northward into much of our forecast
area. This will result in increasing chances of precipitation
through the day especially for locations north and east of the
center of the low. Model guidance has been fairly wishy-washy on
where to place the heaviest rain...but it should be co-located
where we expected the greatest upper level difluence...NE WA/N ID
and near the core of the low near the Cascades. Model stability
parameters would place the greatest risk of thunderstorms along a
theta-e ridge axis wrapping around the top of the low...or from
the central ID Panhandle through the northern tier of WA and into
the Cascades. We cannot entirely rule out severe thunderstorms
based on CAPE values ranging from 1000-2000 j/kg with much weaker
CIN or convective caps than what we are seeing today...however
shear values away from the low are very weak.
By Sunday...the low is only expected to move into the Blue Mts before
opening up into a trough during the afternoon. This will result in
likely showers and thunderstorms across the eastern third of WA
and all of N Idaho through early afternoon. Then yet another
strong upper level low tracks into the nw WA by late in the day.
This low will likely destabilize the Cascades and result in
another round of thunderstorms for much of the area. Heavy rains
will again be possible.
By Monday the second low is expected to meander slowly
s-sw...through SW WA/NW OR which should lessen the chance for
widespread convection for locations north of i90 and keep the risk
of thunder going elsewhere.
Temperatures forecasts over the next several days will prove a
difficult task as much will depend on how widespread the convection
becomes and what areas are impacted. Locations which see full
sunshine will continue to see daytime readings in the 90s...while
locations which see little if any sun could conceivably see highs
in the mid 70s to lower 80s. fx
Monday Night through Friday: No significant changes were made to
the extended range part of the fcst, which keeps the upper low
nearly stationary over the Pacific Nw through Wed. The recent
trend in model guidance has the ECMWF becoming increasingly more
aligned with the GFS the last couple runs. However...the ECMWF was
the quickest with ejecting this stalled upper low NE across the
region than the GFS by mid weak. Now it`s the GFS that has the
faster ejection of the low, pushing its core NE through Oregon and
WA Wed and Wed Nt. A nearly non-existent upper trough on the ECMWF
will dig south down the BC coast Wed Nt. These two models are
nearly 180 degrees out of phase with this digging 500 mb low at
this point...with the GFS much stronger, and certainly a more
effective kicker/ejector of the stalled low. That said, we
continued with a very conservative approach to making any big
changes in the fcst based on the high level of uncertainty caused
by the above mentioned differences. So, we did not go with a wet
fcst for Wed Nt per the GFS. Leaning heavily toward a pattern
recognition approach, we kept at least isolated rain showers and
thunderstorms in nearly every period of the fcst. bz
&&
.AVIATION...
00Z TAFS: Upper level low pressure system spinning over
southwestern WA will continue to bring the risk for thunderstorms
through Saturday afternoon. Strong uncapped instability across the
Cascades and Okanogan Highlands will support the best chances for
evening thunderstorms with the potential for a few strong storms.
KEAT and more so KMWH will be on the southern fringe of this
convection and may see a thunderstorm or two this activity lifts
northward this evening. By tonight, the threat will shift to elevated
thunderstorms around 03Z around the KLWS and KPUW taf sites then
continuing to spread northward and westward into KGEG, KSFF, KCOE
and possibly KMWH by the overnight hours. Convection will develop
again Saturday afternoon with the possibility of -TSRA at all TAF
sites through 00Z Sunday. /EK
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 68 87 65 81 60 84 / 30 40 50 70 50 20
Coeur d`Alene 66 86 62 76 58 84 / 50 50 60 70 50 20
Pullman 64 86 61 82 58 83 / 50 40 50 70 30 20
Lewiston 71 94 70 91 66 92 / 50 30 50 70 20 10
Colville 64 89 62 79 60 87 / 50 60 50 70 60 30
Sandpoint 63 82 58 76 55 82 / 60 70 50 70 50 30
Kellogg 64 83 60 76 56 84 / 90 70 60 80 50 30
Moses Lake 67 93 66 92 62 89 / 20 40 30 30 20 20
Wenatchee 69 93 70 89 65 88 / 30 30 30 30 20 20
Omak 67 95 66 87 63 89 / 50 60 30 50 50 40
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Red Flag Warning until 5 PM PDT Sunday for East Washington
Central Cascade Valleys (Zone 677)-East Washington Northern
Columbia Basin (Zone 673)-East Washington Okanogan/Methow
Valleys (Zone 684)-East Washington South Central Cascade
Valleys (Zone 676).
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
851 PM CDT FRI JUL 13 2012
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND SATURDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW VARIOUS
SHORTWAVE TROUGHS EXTENDING FROM THE BOUNDARY WATERS OF MINNESOTA TO
THE SOUTHERN MISSOURI VALLEY EARLY THIS AFTERNOON. AHEAD OF THESE
TROUGHS...SHOWERS AND THUNDERSTORMS ARE MOST CLUSTERED OVER NORTHERN
MINNESOTA AND ALSO OVER EASTERN IOWA AND NORTHERN MISSOURI. LOCAL
MESOANALYSIS SHOWS CIN HAS ERODED OVER MUCH OF THE AREA WITH DAYTIME
HEATING...AND WIDELY SCATTERED SHOWERS AND STORMS ARE NOW POPPING
ACROSS MUCH OF THE FORECAST AREA. AS THE UPPER TROUGHS UPSTREAM
SLOWLY MOVE EAST OVER THE NEXT 24 HOURS...PRECIP CHANCES ARE THE
MAIN FORECAST CONCERN.
TONIGHT...SHORTWAVE TROUGH OVER MINNESOTA AND OTHER WEAK IMPULSES
ROTATING AROUND IT WILL SLOWLY MOVE SOUTHEAST ACROSS EASTERN
MINNESOTA AND WESTERN WISCONSIN. LARGE-SCALE ASCENT IS PRETTY WEAK
AND MID-LEVEL LAPSE RATES ARE ONLY AROUND 6 C/KM BUT THERE IS AMPLE
MOISTURE AVAILABLE WITH PWATS AROUND AND SLIGHTLY HIGHER THAN 1.50
INCHES. AS A RESULT...THINK SPOTTY SHOWER ACTIVITY THAT POPPED UP
THIS AFTERNOON WILL DIMINISH THIS EVENING. THEN AS THE SHORTWAVE
ENERGY MOVES CLOSER...WILL SEE SCATTERED SHOWERS AND ISOLATED
THUNDER PUSH BACK INTO THE WESTERN AND SOUTHERN PARTS OF THE
FORECAST AREA. NOT ENTIRELY CONFIDENT IN COVERAGE SINCE SHOWERS AND
STORMS WERE FAIRLY WIDESPREAD OVER WESTERN WISCONSIN WHEN I WALKED
IN THE DOOR THIS MORNING. WILL PLAY THE ODDS OF THE DIURNAL CYCLE
AND ERROR ON THE LOW SIDE. A MUGGY NIGHT WITH LOWS IN THE 60S.
SATURDAY...THE SHORTWAVE TROUGH WILL MAKE SLOW PROGRESS EASTBOUND
ACROSS THE STATE THROUGH THE DAY. THE 09Z SREF INDICATES THAT WILL
SEE SHOWERS AND STORMS DEVELOP FAIRLY QUICKLY BETWEEN 15-18Z
TOMORROW WHEN LOW LEVEL LAPSE RATES HAVE A CHANCE TO STEEPEN AND
INSTABILITY TO DEVELOP. CAPES ARE NOT THAT IMPRESSIVE (600-700
J/KG) AND THEY ARE RATHER SKINNY...BUT THERE IS PLENTY OF MOISTURE
AROUND (STILL 1.5 INCHES). WIND FIELDS ARE RATHER LIGHT SO STORMS
SHOULD BE SLOW MOVING...BUT COVERAGE UPSTREAM ONLY SUGGESTS AN
ISOLATED DAMAGING WIND AND HEAVY RAIN THREAT. THOUGH TEMPS WILL BE
A FEW DEGREES COOLER...HIGHER HUMIDITY WILL MAKE IT FEEL MORE
MUGGY. HIGHS RANGING THROUGH THE 80S.
.LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY.
AN UPPER LEVEL SHORT WAVE AND A SURFACE BOUNDARY WILL PASS EAST
OF WISCONSIN DURING THE FIRST PERIOD OF THE FORECAST. ONLY HAVE
CHANCE POPS GOING IN THE EAST AND THEN NOTHING AFTER 06Z
SUNDAY...EXCEPT FOR SOME PATCHY FOG. A WARM FRONT PUSHING NORTH
INTO WISCONSIN WILL BRING MUCH ABOVE NORMAL TEMPERATURES TO THE
AREA...MAINLY ON MONDAY. THERE WILL BE A SLIGHT CHANCE OF SHOWERS
AND STORMS IN THE NORTH ON MONDAY IN THE VICINITY OF THE FRONT.
THERE IS A CHANCE OF THUNDERSTORMS MONDAY NIGHT AND TUESDAY ACROSS
CENTRAL WISCONSIN AS A COLD FRONT MOVES THROUGH THE STATE.
TEMPERATURES SHOULD REMAIN VERY WARM/HOT ON TUESDAY BUT THEY
SHOULD BE A BIT COOLER THAN MONDAY WITH CLOUDS AND POSSIBLE
CONVECTION. PRECIPITATION CHANCES MAINLY CONFINED TO CENTRAL AND
EAST CENTRAL WISCONSIN ON TUESDAY NIGHT...THEN IT LOOKS LIKE A
PERIOD OF DRY WEATHER WITH TEMPERATURES A LITTLE CLOSER TO NORMAL
FOR THIS TIME OF YEAR. A SHORT WAVE MOVING SOUTHEAST ACROSS THE
WESTERN GREAT LAKES REGION WILL BRING A CHANCE OF SHOWERS AND
STORMS TO NORTHERN WISCONSIN ON FRIDAY.
&&
.AVIATION...MOSTLY VFR WEATHER IS EXPECTED OVERNIGHT THOUGH THERE
WILL BE SCATTERED SHOWERS OR THUNDERSTORMS WITH BRIEF MVFR CIGS
AND VSBYS. AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE AREA
SATURDAY AND PRODUCE A GREATER AMOUNT OF SHOWER AND THUNDERSTORM
ACTIVITY.
RDM
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PUEBLO CO
354 AM MDT SAT JUL 14 2012
.SHORT TERM...
(TODAY AND TONIGHT)
PRECIPITABLE WATERS IN 00Z SOUNDINGS AND IN DERIVED
SATELLITE PRODUCTS RUNNING FROM 50 TO 75 PERCENT OF NORMAL ACROSS
THE EASTERN HALF OF THE FORECAST AREA...TO NEAR 130% OF NORMAL
ACROSS THE SOUTHWEST MOUNTAINS. DEEPEST FETCH OF MONSOON MOISTURE
IS CURRENTLY ORIENTED ALONG AN AXIS FROM AZ THROUGH UT INTO ID AND
WESTERN WY. UPPER RIDGE AXIS IS PROGGED TO SHIFT SLOWLY EASTWARD
TODAY PUTTING SOUTH CENTRAL AND SOUTHEAST COLORADO UNDER MORE OF A
SOUTH TO SOUTHWEST FLOW ALOFT. THIS WILL HELP SPEED UP STORM
MOTIONS TODAY (TO THE NORTH NORTHEAST AROUND 10 MPH)...AS WELL AS
EDGE THE MOISTURE AXIS EASTWARD. NAM12 AND HRRR KEEP DEW POINTS
TODAY IN THE LOWER 40S ACROSS CHAFFEE AND LAKE COUNTIES...UP FROM
YESTERDAYS VALUES IN THE 20S AND EVEN SOME TEENS. NAM12 SFC DEW
POINTS ARE STILL LIKELY A BIT OVERDONE...BUT THINK AFTERNOON DEW
POINTS MAINTAINING IN THE 30S LOOKS PLAUSIBLE TODAY AS THE
MOISTURE PLUME SHIFTS EASTWARD. MEANWHILE...SOUTHEAST MTS/PIKES
PEAK REGION SHOULD SEE ANOTHER DAY OF SFC DEW POINTS DROPPING INTO
THE 30S BY AFTERNOON...WHICH SHOULD HELP CUT BACK ON CAPE VALUES
AND KEEP STORMS MORE ISOLATED IN NATURE. WITH STORM MOTIONS TO THE
NORTH OR NORTHEAST...THEY MAY HAVE A SLIGHTLY BETTER CHANCE OF
DRIFTING OFF THE SE MTS INTO THE I-25 CORRIDOR. BUT WITH DRY
SUBCLOUD LAYER...THINK THAT MAIN THREAT WILL BE GUSTY WINDS UP TO
50 MPH...BRIEF LIGHT TO MODERATE RAINFALL AND LIGHTNING...BEFORE
THEY QUICKLY DIMINISH AS THEY MOVE ONTO THE ADJACENT PLAINS.
MEANWHILE...THE HIGHER PRECIPITABLE WATERS ACROSS THE SOUTHWEST AND
CENTRAL MOUNTAINS WILL LEAD TO A BETTER CHANCE FOR HEAVY RAINFALL
OUT THAT WAY...THOUGH WITH STORM MOTIONS A LITTLE FASTER
TODAY...THIS SHOULD KEEP THE FLASH FLOOD THREAT MORE LOCALIZED TO
BURN SCARS AND SUSCEPTIBLE AREAS SUCH AS THE CHALK CLIFFS. ONCE
AGAIN...NOT ENOUGH OF A THREAT TO WARRANT ANY FLASH FLOOD
WATCHES AT THIS POINT.
MAX TEMPERATURES ARE LIKELY TO BE SIMILAR TO THOSE OF
YESTERDAY...PERHAPS A DEGREE OR TWO WARMER ALONG THE I-25 CORRIDOR
DUE TO SOME STRONGER WINDS AND SLIGHTLY DEEPER MIXING. ONCE
CONVECTION DEVELOPS OVER THE MTS THOUGH...CLOUD COVER FROM
THUNDERSTORM ANVILS MAY TEMPER FURTHER WARMING...WHICH SHOULD KEEP
THE I-25 CORRIDOR FROM SEEING TEMPS HIT 100. FARTHER TO THE EAST
HOWEVER...TEMPS WILL LIKELY BREAK THE CENTURY MARK ONCE AGAIN.
THUNDERSTORMS WILL DECREASE IN COVERAGE DIURNALLY SATURDAY
NIGHT...THOUGH WILL KEEP ISOLATED POPS GOING ALONG THE CONTINENTAL
DIVIDE WHERE ACTIVE MONSOON PLUME WILL BE OVERHEAD. MIN TEMPS WILL
BE ON THE WARM SIDE ONCE AGAIN DUE TO CONVECTIVE DEBRIS CLOUDINESS
LINGERING OVER THE REGION. -KT
.LONG TERM...
(SUNDAY THROUGH SATURDAY)
...THREAT OF MORE HEAVY RAIN NEXT WEEK...
NO BIG CHANGES TO THE EXTENDED FORECAST. SUNDAY STILL LOOKS TO BE THE
WARMEST DAY AS H7 TEMPS CLIMB TO 18 DEG C OR HIGHER OVER THE SRN
FRONT RANGE. BULK OF THE PRECIP SHOULD AGAIN BE CONFINED TO THE
CONTDVD...AND WITH SRLY TO SW WINDS...SHOULD EASILY APPROACH OR
EXCEED THE 100 DEG MARK OVR THE ERN PLAINS.
MONDAY...A WEAK FRONTAL SURGE PUSHES ACROSS SERN CO IN THE
AFTERNOON...AS THE MONSOONAL PLUME SHIFTS A BIT EWD INTO CENTRAL
CO. THE INCREASE IN MID LEVEL MOISTURE ALONG WITH INCREASED
UPSLOPE FROM THE SURGE SHOULD SPARK AN INCREASE INCONVECTION ALONG
THE ERN MTS AND ADJACENT PLAINS BY LATE MON AFTERNOON OR EARLY EVE.
HOW QUICKLY THIS OCCURS WILL DETERMINE HIGH TEMPS FOR THE
PLAINS...AS THE LESS AGGRESSIVE GFS SUGGESTS TEMPS NR 100 DEG AGAIN
FOR KPUB. HAVE KEPT CLOSER TO THE SLIGHTLY COOLER NAM/MET...WHICH
PROGS UPPER 90S FOR THE PLAINS.
BY TUE-WED...THE MONSOON IS IN FULL SWING...WITH THE PLUME OVR ERN
CO AS THE UPPER HIGH SHIFTS EWD TO THE SRN PLAINS. SHOULD SEE A
GOOD RAMP UP OF STORMS OVR THE ENTIRE AREA...AND STORMS PERSISTING
A BIT LATER INTO THE EVENING HOURS. FLASH FLOODING FOR THE FLOOD
PRONE AREAS WILL AGAIN BE THE CHIEF CONCERN. GREATEST THREAT ATTM
APPEARS TO BE CENTERED AROUND TUE EVENING...WHEN WE COULD SEE SOME
LOCAL QPF IN THE ONE TO TWO INCH RANGE.
BY THU-FRI...STILL A BIT OF UNCERTAINTY HOW THE SYNOPTIC PICTURE
EVOLVES. IT LOOKS LIKELY THAT THE HIGH WILL START TO SHIFT WWD
AGAIN...BUT TO WHAT EXTENT AND HOW IT WILL AFFECT THE MOISTURE
PLUME IS A BIT UP IN THE AIR. THE EC CONTINUES TO BE ON THE DRY
SIDE...WHILE THE GFS IS SLOWER TO STRENGTHEN THE HIGH OVR AREA AND
CONSEQUENTLY KEEPS MORE MOISTURE STREAMING UP FROM THE S ON THU
AND POSSIBLY INTO FRI. BY LATE IN THE PERIOD...A COMPLICATING
FACTOR IS THE POSSIBILITY OF SOME SUBTROPICAL MOISTURE BEING
CAUGHT UP IN THE UPPER FLOW...WHICH IS HINTED AT IN THE 00Z GFS.
FOR NOW...STUCK WITH THE ENSEMBLE GUIDANCE FOR THE LATTER PART OF
THE FORECAST...WHICH IS FAIRLY CLOSE TO CLIMATOLOGY FOR
POPS/TEMPS. ROSE
&&
.AVIATION...
VFR CONDITIONS EXPECTED AT TAF SITES. SCATTERED TO NUMEROUS
THUNDERSTORMS WILL DEVELOP ALONG THE CONTINENTAL DIVIDE THIS
AFTERNOON AND EVENING...WITH ISOLATED TO SCATTERED THUNDERSTORMS
ACROSS THE SOUTHEAST MOUNTAINS...DRIFTING OFF INTO THE NEIGHBORING
VALLEYS DURING THE AFTERNOON. KALS HAS THE BEST CHANCE OF SEEING AN
ISOLATED -TSRA AND WILL MAINTAIN VCTS IN THE TAF FOR THAT
SITE...WHERE BRIEF VFR CIGS/VIS WILL BE POSSIBLE WITH
THUNDERSTORMS. THERE WILL BE MUCH LESS OF A CHANCE FOR
THUNDERSTORMS TO HIT THE KCOS AND KPUB TAF SITES...SO WILL LEAVE ANY
MENTION OF TS OUT OF THOSE SITES FOR NOW. WINDS WILL INCREASE OUT
OF THE SOUTHEAST AT AROUND 15 KTS FOR BOTH KPUB AND KCOS DURING THE
AFTERNOON. -TSRA WILL DIMINISH QUICKLY AFTER 01-02Z...WITH
CONVECTIVE DEBRIS CLOUD COVER DECREASING GRADUALLY THROUGH THE
OVERNIGHT HOURS. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31/44
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
319 AM CDT SAT JUL 14 2012
.SYNOPSIS...
06Z SFC ANALYSIS HAS SEVERAL SUBTLE TROFS FROM LAKE MICHIGAN BACK
INTO MINNESOTA WITH A COLLAPSING MESOHIGH NEAR KRST. DEW POINTS WERE
GENERALLY IN THE 60S WITH 70S IN THE DEEP SOUTH AND LOWER OHIO
VALLEY. RADAR TRENDS OVER THE PAST SEVERAL HOURS SHOWS OVERALL
CONVECTION IS SLOWLY DISSIPATING.
&&
.SHORT TERM...TODAY AND TONIGHT...
PRECIPITATION SINCE MIDNIGHT HAS EITHER ENDED OR DIMINISHED TO
SPRINKLES/ISOLATED SHRA. EAST OF THE MISSISSIPPI ELEVATED CONVECTION
HAS PERSISTED OR DEVELOPED. RAP TRENDS SHOW THE CONVECTION IS MAINLY
ASSOCIATED WITH SPEED/MOISTURE CONVERGENCE AT 850MB IN RELATIVELY
STRONG LIFT AHEAD OF THE VORT MAX THAT IS ALONG THE MISSISSIPPI. RAP
TRENDS INDICATE THAT THIS ELEVATED CONVECTION WILL PERSIST THE
REMAINDER OF THE NIGHT AND SHOULD DISSIPATE OR EXIT THE CWFA AROUND
MID MORNING.
WEST OF THE MISSISSIPPI SPRINKLES OR ISOLATED ELEVATED CONVECTION
WILL PERSIST OR POSSIBLY DEVELOP AS THE NEXT VORT MAX DROPS INTO THE
TROF FROM NORTHERN IOWA.
FROM LATE MORNING AND CONTINUING INTO THE AFTERNOON...DIURNAL
HEATING WILL ALLOW NEW CONVECTION TO BREAK OUT ACROSS THE CWFA.
BASED ON THE PROJECTED LOCATION OF THE VORT MAXES AND NEGATIVE THETA
E LAPSE RATES...AREAS ALONG/EAST OF THE MISSISSIPPI SHOULD HAVE THE
BETTER CHANCES OF SEEING CONVECTION. THUS THE HIGHER POPS WILL BE
ALONG/EAST OF THE MISSISSIPPI FROM LATE MORNING THROUGH THE
AFTERNOON.
CONVECTION THAT DEVELOPS DURING THE AFTERNOON WILL PERSIST INTO THE
EVENING AND SLOWLY DISSIPATE WITH SUNSET. AFTER MIDNIGHT GENERALLY
DRY CONDITIONS SHOULD BE SEEN WITH SUBSIDENCE BEHIND THE DEPARTING
SHORT WAVE AND BUILDING HEIGHTS. 08
.LONG TERM...SUNDAY THROUGH FRIDAY...
HEAT AND MORE HUMID CONDITIONS WILL RETURN TO THE REGION FOR THE
FIRST HALF OF THE WEEK AS THE WESTERN U.S. UPPER RIDGE EDGES EAST
INTO THE PLAINS. THE DEVELOPING UPPER RIDGE WILL KEEP THE AREA DRY
SUNDAY AND MONDAY. WITH INCREASING SOUTHERLY FLOW AND WAA TEMP
WILL TOP OUT IN THE LOW TO MID 90S SUNDAY AND MAINLY MID 90S FOR
MONDAY. HELD DEW POINTS IN THE MID/UPPER 60S BOTH DAYS WHICH WILL
SUPPORT HEAT INDEX VALUES IN THE 95 TO AROUND 100 RANGE BOTH DAYS.
TUESDAY INTO THURSDAY A DEVELOPING TROF OVER GREAT LAKES AND NEW
ENGLAND WILL SENT A COLD FRONT SOUTH THROUGH THE REGION. THE FRONT
WILL TAKE THE EDGE OFF THE EARLY WEEK HEAT AND IT WILL ALSO
PROVIDE A CHANCE OF RAIN FOR THE REGION. THE FORECAST WAS SKEWED
TOWARD THE ECMWF WHICH BRINGS THE FRONT THROUGH SLOWER THAN THE
OTHER MODELS...ESPECIALLY THE GFS. THE SLOWER MOVEMENT SEEMS
REASONABLE WITH THE FRONT MOVING INTO THE UPPER RIDGE. ALSO MODELS
ARE SHOWING WARM MID LEVELS ALONG AND AHEAD OF THE BOUNDARY
SUGGESTING THE WARM SECTOR WILL BE CAPPED. WITH ALL THE PRECIP
EXPECTED TO BE POST FRONTAL HAVE KEPT TUESDAY DRY AND LIMITED POPS
TUESDAY NIGHT TO THE NORTH HALF. LOW CHANCE POP WERE MAINTAINED
OVER THE ENTIRE AREA WEDNESDAY THEN STARTED TO DRY THE FORECAST OUT
FROM NORTH TO SOUTH WEDNESDAY NIGHT INTO FRIDAY AS THE BOUNDARY PUSHES
FAR ENOUGH SOUTH. WITH THE WARM MID LEVEL TEMPERATURES IN PLACE
AND FORCING ALONG AND NORTH OF THE FRONT REMAINING WEAK ANY
SHRA/TSRA OCCURRING WITH THIS SYSTEM SHOULD BE SCATTERED.
THE FRONT WILL ALSO BRING SOME SLIGHTLY COOLER TEMPERATURES TO THE
AREA FOR MID TO LATE WEEK. HEAT INDEX VALUES AROUND 100 ARE
EXPECTED OVER THE ENTIRE AREA TUESDAY BUT SHOULD BE LIMITED TO THE
SOUTH HALF OF THE AREA WEDNESDAY AND THURSDAY.
DLF
&&
.AVIATION...
ELEVATED CONVECTION HAS DECREASED/DISSIPATED WEST OF THE MISSISSIPPI
WHILE CONTINUING EAST OF THE MISSISSIPPI. DIURNAL HEATING WILL ALLOW
NEW CONVECTION TO DEVELOP AFT 15Z/14 AND BECOME MORE WIDESPREAD
18Z/14 TO 01Z/15. TSRA MAY OCCUR AT ANY TAF SITE WITH KDBQ/KMLI/KBRL
HAVING A BETTER CHANCE THAN KCID. THUS VCTS WILL BE INCLUDED IN THE
12Z TAFS. ONCE DIURNAL HEATING ELIMINATES THE SPOTTY MVFR
CONDITIONS...VFR CONDITIONS ARE EXPECTED THROUGH 12Z/15. MVFR
CONDITIONS WILL BE POSSIBLE WITH ANY TSRA. 08
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
111 AM CDT SAT JUL 14 2012
...UPDATED TO INCLUDE SMALL PRECIPITATION CHANCES MAINLY IN SOUTH
CENTRAL KANSAS...
.SYNOPSIS...
ISSUED AT 1203 AM CDT SAT JUL 14 2012
A 500MB HIGH WAS CENTERED OVER COLORADO AT 00Z SATURDAY WITH AN
UPPER LEVEL RIDGE EXTENDING NORTHWARD ACROSS EASTERN WYOMING AND
MONTANA. AN UPPER LOW WAS LOCATED NEAR THE COAST OF WASHINGTON AND
NORTHWEST OREGON. BETWEEN THIS UPPER HIGH AND LOW TROPICAL
MOISTURE STRETCHED FROM OLD MEXICO ACROSS THE WESTERN UNITED
STATES. EAST OF THE ROCKIES AT 00Z SATURDAY THE 700MB TEMPERATURES
RANGED FROM 11C AT DODGE CITY AND NORTH PLATTE TO +17C AT DENVER.
ALONG AND JUST EAST OF THE GRADIENT AN AREA OF HIGHER DEWPOINTS
WERE OBSERVED ACROSS WESTERN KANSAS. ALSO ACROSS WESTERN KANSAS
THE 850MB TEMPERATURES VARIED FROM THE MID 20S IN SOUTH CENTRAL
KANSAS TO THE UPPER 20S NEAR THE COLORADO BORDER.
&&
.UPDATE...
ISSUED AT 102 AM CDT SAT JUL 14 2012
ISOLATED SHOWERS HAVE BEGUN TO DEVELOP ACROSS PORTIONS OF SOUTH
CENTRAL KANSAS EARLY THIS MORNING. UPPER AIR ANALYSIS DID
INDICATED SOME MID LEVEL MOISTURE PRESENT AS THE NOSE OF A 50-60KT
UPPER LEVEL JET MOVES SOUTH ACROSS CENTRAL KANSAS. HRRR APPEARS TO BE
THE ONLY MODEL PICKING UP ON THIS. DO HOWEVER THINK COVERAGE WILL
NOT BE WIDESPREAD AS WHAT THE HRRR SUGGEST GIVEN THAT WESTERN
KANSAS IS CLOSER TO THE RIGHT EXIT REGION OF THE UPPER JET.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 247 PM CDT FRI JUL 13 2012
VISIBLE SATELLITE IMAGERY SHOWED A BAND OF CUMULUS EXTENDING FROM
THE WAKEENEY/HAYS AREA DOWN THROUGH SOUTH CENTRAL KANSAS. RADAR
WAS SHOWING ISOLATED SHOWERS DEVELOPING ALONG THE OUTFLOW BOUNDARY
AS IT MOVES WEST. THIS BOUNDARY MAY MAKE IT AS FAR WEST AS THE
HAYS/LARNED/STAFFORD VICINITIES LATER THIS AFTERNOON SO WILL ADD
A MENTION OF ISOLATED THUNDERSTORMS IN THAT AREA. THE UPPER LEVEL
HIGH PRESSURE AREA AND UPPER JET WILL BE SLOWLY PROPAGATING EAST
TONIGHT THROUGH SATURDAY. WITH THE BETTER UPPER DYNAMICS MOVING
EAST AND SOUTHEAST OF WESTERN KANSAS WE SHOULD SEE ANY LATE DAY
THUNDERSTORMS DIMINISHING FAIRLY RAPIDLY THIS EVENING. LOW LEVEL
TEMPERATURES AND THICKNESS VALUES ARE NEARLY SIMILAR OR SLIGHTLY
HIGHER ON SATURDAY THAN TODAY. EXPECT HIGH TEMPERATURES TO BE
VERY SIMILAR TO A FEW DEGREES WARMER ON SATURDAY, ESPECIALLY UP
ALONG INTERSTATE 70.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 247 PM CDT FRI JUL 13 2012
MODELS ARE STILL IN GOOD AGREEMENT IN SLOWLY SHIFTING AN UPPER LEVEL
HIGH FROM THE HIGH PLAINS LATE THIS WEEKEND INTO THE MISSISSIPPI
VALLEY BY THE MID PART OF NEXT WEEK. THIS IS DUE TO AN UPPER LEVEL
LONGWAVE TROUGH BUILDING INTO THE WESTERN CONUS. THE MID LEVELS OF
THE ATMOSPHERE WILL REMAIN FAIRLY DRY THROUGH THE FIRST PART OF NEXT
WEEK LEAVING MOSTLY CLEAR SKIES AND DRY CONDITIONS ACROSS WESTERN
KANSAS. THE ONLY EXCEPTION TO THIS WILL BE IN THE AFTERNOON`S WHERE
A FEW CUMULUS CLOUDS COULD FORM. AT THE SURFACE, LEE TROUGHING WILL
CONTINUE ACROSS EASTERN COLORADO IN RESPONSE TO THE AFOREMENTIONED
TROUGH IN THE WESTERN UNITED STATES. SOUTHERLY WINDS WILL BE FELT
ACROSS WESTERN KANSAS BECOMING BREEZY IN THE AFTERNOON DUE TO
ATMOSPHERIC MIXING.
EXTENDED MODELS SUGGEST A FEW WEAK UPPER LEVEL DISTURBANCES TO MOVE
ACROSS EASTERN COLORADO TUESDAY TROUGH THURSDAY MORNING AS THE UPPER
LEVEL HIGH MOVES INTO THE MISSISSIPPI VALLEY. THIS WILL ALLOW FOR
STORMS TO DEVELOP ACROSS EASTERN COLORADO DURING TUESDAY AND
WEDNESDAY AFTERNOON. IF STORMS DO FORM ACROSS EASTERN COLORADO THEY
WILL HAVE TO POTENTIAL TO MOVE INTO FAR WESTERN KANSAS TUESDAY AND
WEDNESDAY NIGHT. I HAVE PLACED A SLIGHT CHANCE OF THUNDERSTORMS IN
THE GRIDS TO REFLECT THIS. ALSO, MOISTURE LOOKS TO INCREASE IN THE
MID LEVELS OF THE ATMOSPHERE DURING THIS TIMEFRAME WHICH WILL ALSO
INCREASE CLOUD COVER ACROSS WESTERN KANSAS. OTHERWISE, THE REMAINDER
OF THE FORECAST AREA LOOKS TO REMAIN DRY WITH PARTLY CLOUDY SKIES.
THE ENTIRE FORECAST AREA LOOKS TO REMAIN DRY ON THURSDAY AS THE
UPPER LEVEL LONG WAVE TROUGH STARTS TO GET EJECTED NORTHWARD AND THE
UPPER LEVEL HIGH REBUILDS ACROSS THE ROCKIES.
AS FOR TEMPERATURES, 850MB TEMPS LOOK TO REMAIN IN THE MID TO UPPER
20S CELSIUS WHICH WOULD TRANSLATE TO HIGHS IN THE MID TO UPPER 90S
ACROSS WESTERN KANSAS. THE ONLY EXCEPTION TO THIS IS IF STORMS MOVE
INTO WESTERN KANSAS TUESDAY AND WEDNESDAY NIGHT AS THE HIGHS COULD
BE A FEW DEGREES COOLER. LOWS THROUGHOUT THE EXTENDED FORECAST
ARE FORECASTED TO RANGE FROM THE UPPER 60S ACROSS THE KS/CO BORDER
TO MID 70S ACROSS SOUTH CENTRAL KANSAS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1203 AM CDT SAT JUL 14 2012
BUFR SOUNDINGS INDICATING ANY MOISTURE ACROSS WESTERN KANSAS WILL
BE AT OR ABOVE THE 9000 FT LEVEL. LATE DAY HEATING SHOULD GIVE
RISE TO INCREASE CLOUDS DURING THE LATE AFTERNOON AND EARLY
EVENING, HOWEVER VFR CONDITIONS ARE EXPECTED. SOUTHEAST WINDS WILL
CONTINUE AT AVERAGE AROUND 10 KNOTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 99 69 97 71 / 10 10 0 10
GCK 99 69 98 70 / 0 0 0 0
EHA 98 68 97 69 / 0 10 0 10
LBL 100 69 98 71 / 0 0 0 10
HYS 101 70 99 73 / 10 10 0 10
P28 100 72 97 73 / 10 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BURGERT
SYNOPSIS...BURGERT
SHORT TERM...GERARD
LONG TERM...HOVORKA_42
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
357 AM EDT SAT JUL 14 2012
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES ALONG WITH INCREASING
HUMIDITY WILL BRING SHOWERS AND A CHANCE FOR THUNDERSTORMS TO THE
AREA THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES AN EAST-WEST ORIENTED
RIDGE AXIS ACROSS THE CAROLINAS WITH A TROUGH AXIS EXTENDING FROM
THE UPPER MIDWEST INTO THE MISSOURI VALLEY. THE UPPER OHIO VALLEY
REMAINS IN A SOUTHWESTERLY FLOW BETWEEN THE TWO FEATURES. AT THE
SURFACE, MOISTURE CONTINUES TO BE ON THE INCREASE WITH WARM DEW
POINT ADVECTION. A WEAK BOUNDARY ACROSS WEST VIRGINIA ALONG WITH A
LOBE OF VORT ENERGY ARE PROVIDING FORCING FOR SCATTERED SHOWERS
MOVING NORTHEASTWARD ACROSS THE STATE.
THE TROUGH AXIS ACROSS THE UPPER MIDWEST WILL EDGE SLOWLY EASTWARD
INTO THE WESTERN GREAT LAKES TODAY WITH A MID-LEVEL SOUTHWESTERLY
FLOW CONTINUING ACROSS THE UPPER OHIO VALLEY. THIS WILL ALLOW FOR
DEEP MOISTURE TO ADVECT ACROSS THE AREA TODAY WITH PRECIPITABLE
WATER VALUES INCREASING TO 1.9 TO 2 INCHES BY EARLY AFTERNOON. THERE
IS A CHANCE OF SHOWERS EARLY AS VORT ENERGY FROM OHIO-WV MOVES INTO
WESTERN PA. THIS AFTERNOON, MORE HEATING IS ANTICIPATED ACROSS THE
FORECAST AREA WITH BREAKS IN CLOUD COVERAGE. WITH SURFACE-BASED
INSTABILITY INCREASING TO AROUND 2000 J/KG AND DEEP LAYER MOISTURE
IN PLACE, SHOWERS ARE LIKELY WITH A CHANCE OF THUNDERSTORMS THIS
AFTERNOON. HEAVY DOWNPOURS WILL BE POSSIBLE WITH CONVECTION TODAY,
ALTHOUGH HAVE HELD OFF ON MENTIONING ANY FLASH FLOODING THREAT IN
THE HWO DUE TO 20-30KT STORM MOTION ANTICIPATED TODAY. GENERALLY A
TENTH TO A QUARTER OF AN INCH OF PRECIPITATION IS FORECAST WITH,
ALTHOUGH LOCALLY HEAVIER AMOUNTS WILL OCCUR WITHIN THUNDERSTORMS.
MAV/MET GUIDANCE HAS TRENDED COOLER FOR TEMPS TODAY, WITH HIGHS IN
THE RANGING FROM THE LOWER 80S NORTH OF PITTSBURGH TO THE MID 80S
ACROSS NORTH- CENTRAL WV.
VORT ENERGY WITH RIPPLES IN 500MB SOUTHWESTERLY FLOW WILL CONTINUE
TO MOVE ACROSS THE AREA TONIGHT. CHANCE POPS WILL CONTINUE DESPITE
THE LOSS OF HEATING. WITH CLOUD COVERAGE AND TDS IN THE UPPER 60S,
LOWS ARE A FEW DEGREES WARMER THAN MAV/MET GUIDANCE, NEAR 70
ACROSS MOST OF THE LOWLANDS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
THERE IS GFS/NAM AGREEMENT THAT THE POSITIVELY MID-LEVEL TROUGH
WILL DE-AMPLIFY AS IT CROSSES THE GREAT LAKES WITH THE FLOW
BECOMING MORE ZONAL LOCALLY ON SUNDAY. WITH A SATURATED
ATMOSPHERIC COLUMN REMAINING IN PLACE AND MODERATE INSTABILITY
ONCE AGAIN, THIS WILL ALLOW FOR SCATTERED SHOWERS AND
THUNDERSTORMS WITH LOCALLY HEAVY DOWNPOURS ACROSS THE AREA.
COVERAGE WILL INCREASE DURING THE AFTERNOON AND EARLY EVENING
HOURS ON SUNDAY. AN ADDITIONAL QUARTER TO HALF OF AN INCH OF
PRECIP IS EXPECTED DURING THE DAY SUNDAY.
NAM/ECMWF INDICATE THAT THE MID-LEVEL FLOW WILL SHIFT TO MORE
NORTHWESTERLY ACROSS THE UPPER OHIO VALLEY AS THE TROUGH SHIFTS EAST
OF THE AREA AND RIDGING BUILDS WESTWARD FROM THE CAROLINAS INTO THE
TN VALLEY. DEEP MOISTURE WILL SHIFT EAST OF THE AREA, WITH
1000-800MB MOISTURE LINGERING. THIS MAY BE SUFFICIENT FOR AN
ISOLATED SHOWER OR THUNDERSTORM TO DEVELOP ON MONDAY AFTERNOON.
TEMPS WILL BE NEAR NORMAL SEASONAL VALUES ON SUNDAY. WITH DRIER
AIR ALOFT ADVECTING INTO THE AREA, DECREASED CLOUD COVERAGE ON
MONDAY WIL ALLOW TEMPS TO WARM TO A FEW DEGREES ABOVE NORMAL, INTO
THE MID TO UPPER 80S ACROSS THE LOWLANDS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
EXPECT CONTINUED HUMID CONDITIONS AND WARMER THAN NORMAL
TEMPERATURES ACROSS THE UPPER OHIO VALLEY DURING THE EXTENDED
PERIOD. WENT CLOSE TO HPC NUMBERS WHICH ARE GENERALLY BETWEEN 5 AND
10 DEGREES ABOVE THE NORM.
A COLD FRONT IS PROGGED TO MOVE SLOWLY SOUTHWARD ACROSS THE GREAT
LAKES TUESDAY INTO EARLY WEDNESDAY...AND THROUGH THE FORECAST AREA
WEDNESDAY. BEHIND THE FRONT, GFSE/ECMWF ARE IN AGREEMENT THAT A
DRIER, NORTHWESTERLY FLOW WILL BRING DRY END TO THE WORK WEEK.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
THE LOW CLOUD DECK ACROSS THE AREA SEEMS TO BE RATHER RAGGED AND
DISCONTINUOUS EARLY THIS MORNING. IT WOULD SEEM THAT THIS DECK
SHOULD AT LEAST PERSIST IF NOT BECOME A BIT MORE DENSE IN THE
AREAS OF MID AND HIGH LEVEL CLEARING TRANSITING NORTHWARD ACROSS
THE AREA PER INFRARED IMAGERY. A NORTHEASTWARD MOVING SYSTEM WILL
BRING THICKER CLOUD COVER AND SHOWERS NORTHWARD ACROSS THE AREA
FROM SOUTH TO NORTH STARTING ROUGHLY 08Z FIRST AROUND KMGW. ALL
SITES SHOULD SEE SHOWERS AT TIME THROUGH THE DAY ON SATURDAY.
AREAS THAT SEE SOME BREAKS ARE QUITE LIKELY TO SEE THUNDERSTORMS
DEVELOP...HOWEVER THEIR LOCATION AND TIMING IS FAR TOO UNCERTAIN
TO PLACE INTO THE CODED TAFS AT THIS TIME. MVFR CONDITIONS WILL
REMAIN COMMON THROUGH THE MORNING HOURS THEN AGAIN BECOME COMMON
AFTER SHOWERS END SATURDAY EVENING. FRIES
OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY...
INCREASED SURFACE LAYER HUMIDITY CAN PROMOTE POSSIBLE RESTRICTIONS
DUE TO PATCHY FOG AND HAZE EACH MORNING, AND SHOWERS AND
THUNDERSTORMS AT ANY TIME.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
244 AM EDT SAT JUL 14 2012
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES ALONG WITH INCREASING
HUMIDITY WILL BRING SHOWERS AND A CHANCE FOR THUNDERSTORMS TO THE
AREA THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
06Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO MAKE
ADJUSTMENTS BASED ON RECENT RADAR TRENDS AND TO LOWER TEMPS A FEW
DEGREES FOR HIGHS TODAY.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES AN EAST-WEST ORIENTED
RIDGE AXIS ACROSS THE CAROLINAS WITH A TROUGH AXIS EXTENDING FROM
THE UPPER MIDWEST INTO THE MISSOURI VALLEY. THE UPPER OHIO VALLEY
REMAINS IN A SOUTHWESTERLY FLOW BETWEEN THE TWO FEATURES. AT THE
SURFACE, MOISTURE CONTINUES TO BE ON THE INCREASE WITH WARM DEW
POINT ADVECTION. A WEAK BOUNDARY ACROSS WEST VIRGINIA ALONG WITH A
LOBE OF VORT ENERGY ARE PROVIDING FORCING FOR SCATTERED SHOWERS
MOVING NORTHEASTWARD ACROSS THE STATE.
THE TROUGH AXIS ACROSS THE UPPER MIDWEST WILL EDGE SLOWLY EASTWARD
INTO THE WESTERN GREAT LAKES TODAY WITH A MID-LEVEL SOUTHWESTERLY
FLOW CONTINUING ACROSS THE UPPER OHIO VALLEY. THIS WILL ALLOW FOR
DEEP MOISTURE TO ADVECT ACROSS THE AREA TODAY WITH PRECIPITABLE
WATER VALUES INCREASING TO 1.9 TO 2 INCHES BY EARLY AFTERNOON. THERE
IS A CHANCE OF SHOWERS EARLY AS VORT ENERGY FROM OHIO-WV MOVES INTO
WESTERN PA. THIS AFTERNOON, MORE HEATING IS ANTICIPATED ACROSS THE
FORECAST AREA WITH BREAKS IN CLOUD COVERAGE. WITH SURFACE-BASED
INSTABILITY INCREASING TO AROUND 2000 J/KG AND DEEP LAYER MOISTURE
IN PLACE, THUNDERSTORMS ARE LIKELY THIS AFTERNOON. HEAVY DOWNPOURS
WILL BE POSSIBLE WITH CONVECTION TODAY, ALTHOUGH HAVE HELD OFF ON
MENTIONING ANY FLASH FLOODING THREAT IN THE HWO DUE TO 20-30KT
STORM MOTION ANTICIPATED TODAY. MAV/MET GUIDANCE HAS TRENDED
COOLER FOR TEMPS TODAY, WITH HIGHS IN THE LOWER 80S ACROSS THE
MAJORITY OF THE LOWLANDS TODAY.
VORT ENERGY WITH RIPPLES IN 500MB SOUTHWESTERLY FLOW WILL CONTINUE
TO MOVE ACROSS THE AREA TONIGHT, WITH CHANCE POPS CONTINUING DESPITE
THE LOSS OF HEATING. WITH CLOUD COVERAGE AND TDS IN THE UPPER 60S,
LOWS ARE A FEW DEGREES WARMER THAN MAV/MET GUIDANCE, NEAR 70 ACROSS
MOST OF THE LOWLANDS.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
UPPER LEVEL TROUGH WILL EXTEND FROM UPPER MICHIGAN SOUTH INTO
ILLINOIS SATURDAY NIGHT...AND WILL TRACK INTO PENNSYLVANIA BY
SUNDAY. MOIST...SOUTHWESTERLY FLOW WILL BRING A CONTINUED CHANCE
FOR SHOWERS AND STORMS. PRECIPITABLE WATER VALUES AROUND 2 INCHES
WILL BRING A CHANCE FOR HEAVY DOWNPOURS IN ANY THUNDERSTORMS THAT
DEVELOP. WITH THE TROUGH AXIS TO THE EAST BY SUNDAY NIGHT AND
MONDAY...CHANCE FOR SHOWERS SHOULD DROP CONSIDERABLY. HAVE DROPPED
POPS TO SLIGHT CHANCE ON MONDAY...EXCEPT FOR CHANCE POPS IN THE
RIDGES. TEMPERATURES SHOULD BE NEAR OR SLIGHTLY ABOVE NORMAL.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
EXPECT CONTINUED HUMID CONDITIONS AND WARMER THAN NORMAL
TEMPERATURES ACROSS THE UPPER OHIO VALLEY DURING THE EXTENDED
PERIOD. WENT CLOSE TO HPC NUMBERS WHICH ARE GENERALLY BETWEEN 5 AND
10 DEGREES ABOVE THE NORM.
A COLD FRONT IS PROGGED TO MOVE SLOWLY SOUTHWARD ACROSS THE GREAT
LAKES TUESDAY INTO EARLY WEDNESDAY...AND THROUGH THE FORECAST AREA
WEDNESDAY INTO THURSDAY. FORECAST INCLUDES SCATTERED POPS FOR
SHOWERS AND STORMS WEDNESDAY INTO THURSDAY...TAPERING TO ISOLATED
COVERAGE BY FRIDAY.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
THE LOW CLOUD DECK ACROSS THE AREA SEEMS TO BE RATHER RAGGED AND
DISCONTINUOUS EARLY THIS MORNING. IT WOULD SEEM THAT THIS DECK
SHOULD AT LEAST PERSIST IF NOT BECOME A BIT MORE DENSE IN THE
AREAS OF MID AND HIGH LEVEL CLEARING TRANSITING NORTHWARD ACROSS
THE AREA PER INFRARED IMAGERY. A NORTHEASTWARD MOVING SYSTEM WILL
BRING THICKER CLOUD COVER AND SHOWERS NORTHWARD ACROSS THE AREA
FROM SOUTH TO NORTH STARTING ROUGHLY 08Z FIRST AROUND KMGW. ALL
SITES SHOULD SEE SHOWERS AT TIME THROUGH THE DAY ON SATURDAY.
AREAS THAT SEE SOME BREAKS ARE QUITE LIKELY TO SEE THUNDERSTORMS
DEVELOP...HOWEVER THEIR LOCATION AND TIMING IS FAR TOO UNCERTAIN
TO PLACE INTO THE CODED TAFS AT THIS TIME. MVFR CONDITIONS WILL
REMAIN COMMON THROUGH THE MORNING HOURS THEN AGAIN BECOME COMMON
AFTER SHOWERS END SATURDAY EVENING. FRIES
OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY...
INCREASED SURFACE LAYER HUMIDITY CAN PROMOTE POSSIBLE RESTRICTIONS
DUE TO PATCHY FOG AND HAZE EACH MORNING, AND SHOWERS AND
THUNDERSTORMS AT ANY TIME.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1156 PM CDT FRI JUL 13 2012
.UPDATE...
ISSUED AT 750 PM CDT FRI JUL 13 2012
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE ACROSS
WEST CENTRAL ILLINOIS AND EAST CENTRAL AND SOUTHEAST MISSOURI THIS
EVENING ALONG AN OUTFLOW BOUNDARY FROM THIS AFTERNOONS CONVECTION.
GIVEN THE LOSS OF DIURNAL HEATING...SEVERE WEATHER IS NOT
ANTICIPATED...THOUGH SOME LOCATIONS COULD SEE VERY HEAVY
DOWNPOURS AND GUSTY WINDS. GIVEN THE SHORTWAVE PROGGED TO MOVE
INTO NORTHERN MISSOURI TONIGHT...EXPECT SOME ISOLATED STORMS TO
CONTINUE INTO THE OVERNIGHT HOURS ACROSS THE AREA.
TEMPERATURES ACROSS CENTRAL...NORTHEASTERN...AND EAST CENTRAL
MISSOURI HAVE COOLED DOWN SIGNIFICANTLY DUE TO PRECIPITATION
ACROSS THE AREA THIS AFTERNOON AND EVENING...THUS HAVE MADE
ADJUSTMENTS TO BOTH THE SHORT TERM TEMPERATURE TRENDS AND THE
OVERNIGHT LOW TEMPERATURES. ASIDE FROM TEMPERATURES...JUST MINOR
CHANGES TO OTHER FORECAST VARIABLES HAVE BEEN WARRANTED...AS THE
GOING FORECAST IS ON TRACK.
JP
&&
.SHORT TERM...
ISSUED AT 248 PM CDT FRI JUL 13 2012
(TONIGHT)
SCATTERED CONVECTION HAS DEVELOPED ACROSS THE NWRN HALF OF THE CWA
AHEAD OF A PV ANOMALY THAT WAS LOCATED OVER IA PER WATER VAPOR
IMAGERY AND RAP 1.5 PVU FIELDS. MAINLY PULSE-TYPE THUNDERSTORMS ARE
EXPECTED DUE TO WEAK SHEAR COMBINED WITH LITTLE CINH AND A FEW
THOUSAND J/KG OF CAPE. DRY SUBCLOUD LAYER AND A WELL-MIXED
BOUNDARY LAYER WILL ONCE AGAIN SUPPORT OCCASIONAL DOWNBURSTS WHEN
THE CORES OF THE STRONGEST STORMS COLLAPSE HOWEVER WIDESPREAD
SEVERE WEATHER IS NOT EXPECTED AT THIS TIME. PCPN COVERAGE SHOULD
DIMINISH LATER THIS EVENING WITH THE LOSS OF DAYTIME HEATING
HOWEVER A FEW AREAS OF ELEVATED CONVECTION MIGHT CONTINUE TO
PERCOLATE OVERNIGHT AS THE SHORTWAVE MOVES INTO NRN MO.
KANOFSKY/CARNEY
&&
.LONG TERM...
ISSUED AT 248 PM CDT FRI JUL 13 2012
(TOMORROW THROUGH NEXT THURSDAY)
VORT MAX MOVING ACROSS THE UPPER MIDWEST AND ITS ASSOCIATED SFC
TROF WILL PROVIDE BOTH A SOURCE OF LARGE SCALE LIFT AND A LOW
LEVEL FOCUSING MECHANISM FOR SCT TSRA/SHRA TOMORROW. GENERALLY
PULSE-TYPE THUNDERSTORMS ARE EXPECTED DUE TO WEAK SHEAR. ISOLATED
DIURNAL PCPN MAY REDEVELOP AND LINGER ACROSS THE SERN HALF OF THE
CWA ON SUN AND MON AS THE TROF SETTLES SEWD AND THE ELONGATED
VORTICITY AXIS SHEARS OUT.
A GRADUAL WARMING TREND IS EXPECTED OVER THE NEXT SEVERAL DAYS AS AN
UPPER LEVEL RIDGE BUILDS EWD. H85 TEMPERATURES OF 20-24 DEG C WOULD
SUPPORT AFTN HIGHS RANGING FROM THE MID 90S TO NEAR THE CENTURY
MARK. THE CENTRAL REGION ALLBLEND INITIALIZATION REMAINS
CONTAMINATED BY INCORRECT GFS OUTPUT /NCEP STAFF CONTINUE TO
TROUBLESHOOT BUT HAVE NOT YET IDENTIFIED THE SOURCE OF THE
PROBLEM/ THEREFORE I DEVIATED SIGNIFICANTLY FROM THE RECOMMENDED
INITIALIZATION TO REDUCE POPS AND RAISE TEMPS ON DAYS 4-7. A WEAK
SFC FRONT WILL APPROACH THE CWA ON WED/THU AND MOISTURE POOLING
AHEAD OF THE FRONT COULD DRIVE HEAT INDEX READINGS OVER 105 DEG F
IN SOME AREAS. ISOLATED TO SCATTERED THUNDERSTORMS WILL BE
POSSIBLE THROUGH THE EXTENDED PD HOWEVER THERE ARE NO STRONG
SIGNALS TO SUPPORT HIGHER THAN SCHC POPS ACROSS MO/IL WHICH
REMAINS IN A MODERATE TO SEVERE DROUGHT.
KANOFSKY
&&
.AVIATION...
ISSUED AT 1152 PM CDT FRI JUL 13 2012
VFR CONDITIONS EXPECTED OUTSIDE OF CONVECTION. MID AND HIGH LEVEL
DEBRIS CLOUDS FROM EARLY EVENING CONVECTION WILL SLOWLY DISSIPATE
OVERNIGHT. NEXT SHORTWAVE MOVING SOUTH THROUGH IOWA COULD SPARK A
FEW SHOWERS OVERNIGHT...BUT COVERAGE TOO LOW TO INCLUDE INTO
FORECAST AT THIS TIME.
A BETTER CHANCE OF SCT CONVECTION WILL DEVELOP WITH DAYTIME
HEATING SATURDAY AFTERNOON. HAVE PROB30 IN FORECAST FOR ST. LOUIS
METRO TERMINALS.
SPECIFICS FOR KSTL...
VFR CONDITIONS TO CONTINUE WITH LIGHT AND VARIABLE WIND OVERNIGHT.
A RENEWED THREAT OF CONVECTION WILL DEVELOP SATURDAY AFTERNOON AS
ATMOSPHERE BECOMES UNSTABLE AND WEAK SHORTWAVE RIPPLES SOUTHEAST
INTO THE AREA.
CVKING
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BUFFALO NY
348 AM EDT SAT JUL 14 2012
.SYNOPSIS...
WARM AND MOIST AIR FROM THE OHIO VALLEY WILL BUILD INTO THE
REGION THIS WEEKEND...RESULTING IN A CONTINUATION OF ABOVE NORMAL
TEMPERATURES AND AN INCREASING CHANCE FOR SHOWERS AND THUNDERSTORMS.
SLIGHTLY DRIER AIR WILL ENTER EARLY NEXT WEEK...WHILE THE MID-SUMMER
HEAT IS FORECAST TO REMAIN IN PLACE.
&&
.NEAR TERM /THROUGH TONIGHT/...
BROAD HIGH PRESSURE WILL REMAIN ACROSS THE EASTERN SEABOARD...WHICH
WILL MAINTAIN A WARM SOUTHERLY FLOW ACROSS WESTERN NEW YORK. TODAY
SHOULD START OFF WITH A FAIR AMOUNT OF SUNSHINE ACROSS WESTERN NEW
YORK. ANY SHOWER SHOULD BE VERY ISOLATED IN NATURE THROUGH THE
MORNING HOURS.
AS WAS THE CASE YESTERDAY...DIURNAL INSTABILITY WILL DEVELOP DURING
THE AFTERNOON HOURS. WHILE A WEAK UPPER LEVEL DISTURBANCE MOVED
ACROSS THE REGION YESTERDAY...GUIDANCE SUGGESTS WEAK UPPER RIDGING
THIS AFTERNOON. WHILE THIS PROBABLY WILL NOT BE ENOUGH TO PREVENT
CONVECTION TO DEVELOP...THIS SHOULD KEEP COVERAGE QUITE
LIMITED...PERHAPS EVEN A BIT LESS THAN YESTERDAY. THIS STILL
JUSTIFIES CHANCE POPS IN THE SAME REGIONS PRONE TO SHOWERS AND
THUNDERSTORMS YESTERDAY...THOUGH CELLS MAY DEVELOP IN SLIGHTLY
DIFFERENT LOCATIONS. MEAN QPF FORECASTS FROM THE SREF/NAM/RGEM/GFS
ACTUALLY PAINT A PRETTY GOOD GENERAL PICTURE OF THIS...AND RUNS OF
THE HRRR APPEAR TO SPARK CONVECTION SHORTLY AFTER NOON.
LAKE BREEZES WILL ENHANCE SURFACE CONVERGENCE...WITH THE BEST CHANCE
FOR THUNDERSTORMS SOUTH AND EAST OF BUFFALO ALONG AND EAST OF THE
ERIE LAKE BREEZE. STORMS WILL AGAIN BE SLOW MOVERS...AND WHILE THE
MAJORITY OF THE REGION WILL REMAIN DRY...THUNDERSTORMS WHICH DO
DEVELOP COULD BRING SIGNIFICANT RAINS TO A ISOLATED LOCATIONS.
TODAY SHOULD CONTINUE TO BE WARM...WITH HIGHS LIKELY TO CLIMB INTO
THE 80S ACROSS THE REGION...SIMILAR TO PERHAPS A TAD COOLER THAN
YESTERDAY.
THE FORECAST GETS A BIT TRICKIER TONIGHT. MORE MOIST AIR ACROSS THE
OHIO VALLEY WILL BUILD INTO THE REGION TONIGHT. DEW POINTS WILL RISE
INTO THE UPPER 60S TO LOWER 70S...WHICH WILL INCREASE INSTABILITY
EVEN DURING THE NIGHTTIME HOURS. MODEL GUIDANCE IS INCONSISTENT ON
THE DEVELOPMENT OF SHOWERS TONIGHT...WITH SOME MODELS (NAM/RGEM)
FAIRLY BULLISH ON THUNDERSTORMS TONIGHT WHILE OTHERS
(UKMET/EUROPEAN/GFS) TENDING TO SHOW LESS ACTIVITY OR KEEP IT TO THE
SOUTH. WITH NO WELL DEFINED BOUNDARY...EXPECT ANY ACTIVITY TO BE
SCATTERED IN NATURE...AND LIKELY TO COME WITH OR AFTER THE MOIST
AIRMASS BUILDS IN. THERE IS A SLIGHTLY GREATER CHANCE FOR SHOWERS
AND THUNDERSTORMS IN THE SOUTHERN TIER...BUT SEE A CHANCE AT ANY
LOCATION LATE TONIGHT AS THE MOIST AIR MOVES INTO THE BOUNDARY LAYER.
WARMER DEW POINTS SHOULD KEEP TEMPERATURES FROM DROPPING TOO MUCH
TONIGHT...WITH OVERNIGHT LOWS LIKELY TO BE IN THE UPPER 60S AND
LOWER 70S. ALSO EXPECT FOG TO BE A BIT MORE WIDESPREAD...ESPECIALLY
IF SKIES CLEAR OUT AT ALL.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
ON SUNDAY...THE SHORT TERM GUIDANCE IS IN FAIR AGREEMENT THAT AN
INITIAL WEAK SHORTWAVE TROUGH DRAPED FROM THE FINGER LAKES EASTWARD
INTO CENTRAL/EASTERN NEW YORK WILL SLIDE EAST OF THE AREA DURING THE
COURSE OF SUNDAY MORNING...WITH ITS ASSOCIATED SWATH OF DEEPER
MOISTURE/POSSIBLE CONVECTION ALSO GETTING DRAGGED OFF INTO EASTERN
NEW YORK. "POSSIBLE" IS THE KEY WORD HERE WITH RESPECT TO THE
CONVECTIVE POTENTIAL ASSOCIATED WITH THIS INITIAL WAVE...AS THE
VARIOUS GUIDANCE PACKAGES EXHIBIT CONSIDERABLE DISAGREEMENT AS TO
THE EXTENT OF THE AVAILABLE LIFT/MOISTURE AND RESULTANT CONVECTION.
IN ONE CAMP ARE THE NAM AND GFS...WHICH ARE A BIT MORE ROBUST AND
SHOW AT LEAST SOME SCATTERED CONVECTION ACROSS PORTIONS OF THE
FINGER LAKES AND NORTH COUNTRY...WHILE THE ECMWF AND GEM ARE BOTH
NOTABLY WEAKER AND ACTUALLY GENERATE LITTLE IF ANY CONVECTION.
BEHIND THIS INITIAL WAVE...CLOUD COVER WILL LIKELY THIN OUT AT LEAST
ENOUGH TO ALLOW FOR SOME PARTIAL SUNSHINE BY LATE MORNING/EARLY
AFTERNOON AS THE DEEPER MOISTURE SLIDES OFF TO OUR EAST...ALLOWING
FOR DECENT HEATING OF A VERY WARM AND HUMID AIRMASS...AND IN TURN
LEADING TO INCREASING AMOUNTS OF DIURNAL INSTABILITY. AT THE SAME
TIME...THE MAIN AXIS OF THE LARGE-SCALE UPPER TROUGH WILL BE SLIDING
EAST FROM THE CENTRAL GREAT LAKES...AND THIS ALONG WITH POTENTIAL
LAKE BREEZE BOUNDARIES SHOULD HELP TO TRIGGER A ROUND OF MORE
GENERAL SCATTERED CONVECTION DURING THE AFTERNOON.
WITH ALL OF THE ABOVE FACTORS IN MIND...HAVE ELECTED TO CUT BACK ON
SUNDAY`S POPS FROM OUR EXISTING CONTINUITY...LOWERING THESE FROM LOW
LIKELY BACK TO THE CHANCE RANGE. MORE SPECIFICALLY...FOR SUNDAY
MORNING HAVE INDICATED HIGH CHANCE POPS ACROSS OUR EASTERN ZONES IN
ASSOCIATION WITH THE INITIAL DEPARTING WAVE AND ASSOCIATED SLUG OF
DEEPER MOISTURE...WHILE PLACING PROGRESSIVELY LOWER PRECIP CHANCES
FURTHER TO THE WEST. AFTER THAT...HAVE TRANSITIONED TO MORE OF A
BROADBRUSH MID-CHANCE RANGE POP FOR THE AFTERNOON DUE TO THE
APPROACHING UPPER TROUGH AXIS AND INCREASING DAYTIME INSTABILITY.
AS FOR TEMPS...EXPECT VERY WARM AND HUMID CONDITIONS TO CONTINUE...
WITH WIDESPREAD HIGHS IN THE MID-UPPER 80S COUPLED WITH DEWPOINTS
IN THE UPPER 60S.
SUNDAY NIGHT...ANY LINGERING DIURNALLY-DRIVEN CONVECTION SHOULD TEND
TO SLOWLY FADE OUT FROM WEST TO EAST WITH THE LOSS OF DAYTIME
HEATING AND THE DEPARTURE OF THE AFOREMENTIONED TROUGH AXIS...WHICH
WILL GIVE WAY TO BROAD/FLAT SHORTWAVE RIDGING. ACCORDINGLY...HAVE
INDICATED PRECIP CHANCES FALLING BACK THROUGH THE CHANCE RANGE AND
EVENTUALLY TO SLIGHT CHANCE DURING THE OVERNIGHT HOURS...WITH MUCH
OF THE SECOND HALF OF THE NIGHT LIKELY TO BE LARGELY RAIN FREE.
SULTRY CONDITIONS WILL CONTINUE THOUGH...WITH OVERNIGHT LOWS RANGING
FROM THE MID 60S IN THE INTERIOR OF THE SOUTHERN TIER AND NORTH
COUNTRY...TO THE LOWER 70S ACROSS THE LAKE PLAINS.
THEREAFTER...THE REMAINDER OF THE SHORT TERM PERIOD SHOULD LARGELY
FEATURE A CONTINUATION OF UNCOMFORTABLY WARM TO HOT AND HUMID
TEMPERATURES ALONG WITH LARGELY DRY CONDITIONS...AS OUR AREA WILL
REMAIN UNDER THE INFLUENCE OF A BROAD/FLAT UPPER RIDGE OUT AHEAD OF
A COLD FRONT SLOWLY SAGGING SOUTHWARD FROM CENTRAL ONTARIO PROVINCE.
THIS RIDGE SHOULD PROVIDE ENOUGH OF A CAP TO PRECLUDE MUCH MORE THAN
SOME ISOLATED DIURNAL CONVECTION ACROSS THE BULK OF THE AREA BOTH
DAYS...THOUGH SLIGHTLY HIGHER CHANCES FOR CONVECTION COULD REACH THE
SAINT LAWRENCE VALLEY AND NORTH COUNTRY LATER TUESDAY AFTERNOON IF
THE CURRENT GFS/ECMWF TIMING OF THE FRONT DOES INDEED COME TO
FRUITION.
IN TERMS OF TEMPERATURES...850 MB TEMPS OF AROUND +17C MONDAY WILL
CLIMB TO AS HIGH AS +18C/+19C TUESDAY...WHICH SHOULD BE ENOUGH TO
SUPPORT FAIRLY WIDESPREAD HIGHS IN THE UPPER 80S TO LOWER 90S
MONDAY...AND LIKELY EVEN A FEW DEGREES HIGHER THAN THAT ON TUESDAY.
IN BETWEEN WILL BE ANOTHER SULTRY NIGHT MONDAY NIGHT...WHEN LOWS
WILL AGAIN MAINLY RANGE FROM THE MID 60S TO LOWER 70S. THROUGHOUT
THIS TIME...DEWPOINTS WILL REMAIN AT UNCOMFORTABLE LEVELS IN THE MID
TO UPPER 60S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
THE GFS AND ECMWF ARE IN DECENT AGREEMENT IN SHOWING THE COLD FRONT
CROSSING THE FORECAST AREA SOMETIME BETWEEN TUESDAY NIGHT AND
WEDNESDAY...WITH CANADIAN HIGH PRESSURE THEN BUILDING ACROSS THE
GREAT LAKES DURING THE REMAINDER OF THE PERIOD ALONG WITH A RETURN
TO COOLER/DRIER WEATHER. GIVEN SOME CONTINUED DIFFERENCES IN THE
EXACT TIMING OF THE FRONT...WILL CARRY BROADBRUSH SHOWER AND
THUNDERSTORM CHANCES TUESDAY NIGHT AND WEDNESDAY...WITH DRY WEATHER
THEN INDICATED FOR THE REMAINDER OF THE WORK WEEK.
TEMPERATURE-WISE...WILL HAVE VERY WARM AND HUMID CONDITIONS
CONTINUING INTO TUESDAY NIGHT IN ADVANCE OF THE APPROACHING
FRONT...WITH READINGS THEN SETTLING BACK TO AT LEAST MORE SEASONABLE
LEVELS FOR THE BALANCE OF THE WEEK...ALONG WITH MUCH MORE
COMFORTABLE HUMIDITY TO BOOT. IN FACT...IF THE LATEST GFS/ECMWF
DEPICTION OF 850 MB TEMPS OF +8C TO +10C FOR THURSDAY AND FRIDAY
TURNS OUT TO BE CORRECT...TEMPS THEN COULD EVEN BE A BIT COOLER THAN
PRESENTLY INDICATED.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE WILL REMAIN GENERALLY IN CONTROL THROUGH THIS
MORNING...WITH MINIMAL SHOWER ACTIVITY EXPECTED THROUGH THE MORNING
HOURS. TEMP/DEW POINT SPREADS STILL RUNNING QUITE WIDE...WITH ALL
SITES LIKELY TO REMAIN FOG-FREE.
AFTER THIS...DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS SHOULD
DEVELOP. LIKE YESTERDAY...THESE SHOULD BE SCATTERED IN
NATURE...TENDING TO FORM ALONG OR INLAND OF LAKE-BREEZE
BOUNDARIES. WHILE ITS HARD TO COMPLETELY RULE OUT A SHOWER OR
THUNDERSTORM AT BUF/IAG/ART...FEEL CHANCES ARE QUITE LOW...WITH A
SLIGHTLY BETTER CHANCE AT ROC. THE BEST CHANCE IS AT JHW...WITH
THUNDERSTORMS LIKELY TO DEVELOP AT OR NEAR THE TAF SITE DURING THE
AFTERNOON HOURS TODAY...THOUGH THE EXACT TIMING REMAINS PROBLEMATIC.
ADDITIONAL MOISTURE WILL MOVE IN TONIGHT...AND THIS WILL BRING A
CHANCE OF SHOWERS AND THUNDERSTORMS LATE THIS EVENING AND TONIGHT.
WHATEVER ACTIVITY DOES DEVELOP SHOULD MOVE FROM WEST TO EAST ACROSS
THE REGION TONIGHT. FOG IS ALSO A POSSIBILITY...THOUGH IT WILL
DEPEND ON WHERE SHOWERS DEVELOP AND IF SKIES CLEAR FOLLOWING THIS
DEVELOPMENT.
OUTLOOK...
SUNDAY...AREAS OF MVFR IN SCATTERED -SHRA/-TSRA.
MONDAY AND TUESDAY...MAINLY VFR.
WEDNESDAY...AREAS OF MVFR IN SCATTERED -SHRA/-TSRA.
&&
.MARINE...
HIGH PRESSURE OVER PA WILL MOVE TO THE EAST COAST TODAY...WITH A
WEAK TROUGH MOVING IN ON SUNDAY. SCATTERED CONVECTION MAY DEVELOP
WITH TROUGH...PRIMARILY SATURDAY NIGHT AND/OR SUNDAY. WINDS AND
WAVES WILL OTHERWISE REMAIN GENERALLY LIGHT WITH LOCAL LAKE BREEZE
CIRCULATIONS TODAY. A SOUTHWESTERLY FLOW WILL PREVAIL ON SUNDAY BUT
WITH SUB-SMALL CRAFT CONDITIONS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL
MARINE...APFFEL/JJR
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1142 PM CDT FRI JUL 13 2012
.UPDATE...ADDED AVIATION SECTION FOR 06Z TAF`S.
&&
.AVIATION...BNA/CKV/CSV...A FEW SHOWERS REMAINS FROM THE EARLIER
ACTIVITY, WITH DEW POINT DEPRESSIONS SHRINKING AND GENERALLY CALM
WINDS. EXPECT MAINLY LIGHT FOG TO DEVELOP AFTER MIDNIGHT, AS THE
GROUND REMAINS SOGGY AFTER SEVERAL DAYS OF RAINFALL. CONVECTION
WILL ONCE AGAIN DEVELOP TOMORROW MAINLY DURING THE LATE MORNING
AND AFTERNOON AS THE ATMOSPHERE REMAINS MOIST AND UNSTABLE AND AN
UPPER TROUGH APPROACHES MIDDLE TENNESSEE.
&&
.PREV DISCUSSION... /ISSUED 911 PM CDT FRI JUL 13 2012/
UPDATE...BAND OF MOSTLY CLEAR SKIES OVER MIDDLE TN THIS EVENING,
BETWEEN I-65 AND THE CUMBERLAND PLATEAU, IS PROBABLY THE MOST
EXTENSIVE AREA OF DECREASED CLOUDINESS THAT WE`VE SEEN IN THE LAST
2 TO 4 DAYS. THIS BAND COINCIDES WITH AN AREA OF DECREASED
1000-500MB MEAN RH, WHICH IS EXPECTED TO MIGRATE SLOWLY TO THE
NORTHWEST OVERNIGHT AND REMAIN, FOR THE MOST PART, REMAIN PRECIP-
FREE. THE BEST CHANCE FOR SHOWERS AND THUNDERSTORMS WILL BE OVER
THE EXTREME NORTHWEST AND SOUTHERN AND WESTERN AREAS, WHERE
REGIONAL RADAR LOOPS SHOW EITHER ONGOING OR APPROACHING SHOWERS.
LATEST WRF, HRR AND RUC MODEL SOLUTIONS APPEAR TO AGREE WITH THIS
GENERAL IDEA
WILL LOWER POPS TO 20% IN THE BAND OF DECREASED MEAN RH (INCLUDING
THE NASHVILLE AREA), AND ADD THE POSSIBILITY FOR LATE NIGHT PATCHY FOG
(ESPECIALLY IN AREAS WHERE CLOUDS REMAIN THINNEST THE LONGEST).
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
ROSE
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
413 AM CDT SAT JUL 14 2012
.DISCUSSION...
RADAR IS FAIRLY QUIET THIS MORNING BUT AM EXPECTING SHRA/TSRA TO
INCREASE IN COVERAGE TOWARD DAYBREAK. AT 850 MB...A WEAK AREA OF
LOW PRESSURE WAS NOTED OVER EAST CENTRAL LOUISIANA AND THIS
POSITION IS MUCH FURTHER EAST THAN THE PAST FEW MORNINGS. A WEAK
TROUGH AXIS EXTENDS SOUTH INTO THE NORTHERN GULF OF MEXICO. 850 MB
DEW PTS HAVE DROPPED TO 12-14C BUT PW VALUES REMAIN FAIRLY HIGH
BETWEEN 1.9 AND 2.0 INCHES. AT 250 MB...AN UPPER LEVEL RIDGE WAS
LOCATED OVER THE FOUR CORNERS WITH A SECOND RIDGE OVER GEORGIA.
BETWEEN THE TWO RIDGES IS CYCLONIC SHEAR AXIS THAT EXTENDS FROM
SOUTHERN ILLINOIS TO TEXARKANA TO CORPUS CHRISTI. SOUTHEAST TEXAS
WILL LIE TO THE EAST OF THIS FEATURE TODAY SO AM EXPECTING
SCATTERED SHRA/TSRA. MOISTURE LEVELS ARE STILL RATHER HIGH AND
STORM MOTION IS SLOW SO ANY STORMS THAT DEVELOP WILL HAVE THE
POTENTIAL TO PRODUCE LOCALLY HEAVY RAIN. THAT SAID...FEEL THE
THE HEAVY RAIN THREAT IS LESS THAN THE PAST FEW DAYS AND ATTM DO
NOT FEEL A FLOOD WATCH IS WARRANTED. THE RAP MODEL IS AGGRESSIVE
WITH RAIN CHANCES THIS MORNING WHILE OTHER SHORT TERM MODELS ARE
MORE BENIGN.
THE UPPER LEVEL SHEAR AXIS WILL SLOWLY SHIFT WEST ON SUNDAY. THE
NAM AND ECMWF CONTINUE TO DEVELOP A WEAK 500 MB LOW OR INVERTED
TROUGH. THIS WILL KEEP SOUTHEAST TEXAS IN A FAVORABLE POSITION
FOR ADDITIONAL PCPN. WILL LEAN TOWARD A NAM/ECMWF BLEND FOR
SUNDAY. MON-WED LOOK TO BE FAIRLY TYPICAL FOR SOUTHEAST TEXAS WITH
MAX TEMPS IN THE LOW TO MID 90S AND SHRA/TSRA DEVELOPING ALONG THE
SEA BREEZE. WILL CONTINUE TO 20/30 POPS FOR THE PERIOD. UPPER
LEVEL RIDGING WILL TRY TO BUILD BACK INTO SOUTHEAST TEXAS LATER
NEXT WEEK SO WILL TREND THE SECOND HALF OF NEXT WEEK WARMER AND
DRIER. 43
&&
.AVIATION...
CENTRAL AND NORTHERN TAF SITES WILL HAVE MOSTLY MVFR CIGS THIS AM
WHILE VFR CONDITIONS WILL PREVAIL CLOSER TO THE COAST. IFR CIGS IS
ALSO POSSIBLE ESPECIALLY AT KCXO WITH SOME MVFR VSBY POSSIBLE.
EXPECT CONDITIONS TO BECOME MOSTLY VFR AFTER 16Z. RAINSHOWERS AND
SOME WIDELY SCATTERED THUNDERSTORMS WILL BEGIN TO DEVELOP AFTER 14Z
AND INCREASE IN COVERAGE AFTER 18Z WITH MVFR CIGS AND VSBY POSSIBLE
IN AND NEAR PCPN ALONG WITH SOME GUSTY WINDS. EXPECT PCPN TO
DIMINISH AROUND 00Z WITH MVFR CIGS RETURNING TO MOST TAF SITES AFTER
06Z. 34
&&
.MARINE...
NO SIGNIFICANT CHANGES TO CURRENT FCST TRENDS. A WEAK SURFACE TROUGH
WILL KEEP LIGHT WINDS IN PLACE THROUGH THE WEEKEND. THE LINGERING
UPPER LEVEL TROF WILL ALSO KEEP SCATTERED STORMS IN THE FCST THROUGH
THE WEEKEND. BRIEF GUSTY WINDS/ELEVATED SEAS ARE POSSIBLE IN AND
NEAR THE STRONGER STORMS. 34
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 91 73 90 73 92 / 40 20 50 20 30
HOUSTON (IAH) 90 74 89 74 91 / 50 20 50 20 30
GALVESTON (GLS) 88 80 88 82 90 / 50 30 50 30 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...43
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1145 PM CDT FRI JUL 13 2012
.AVIATION...
SOME MVFR CLOUDS HAVE DEVELOPED LATE THIS EVENING ACROSS SOUTHEAST TEXAS
WHILE RADAR REMAINS QUIET. HAVE GONE AHEAD AND MENTIONED SOME LOW CLOUDS
AND POSSIBLE FOG AT SOME OF THE SITES. STILL THINK THE MAJORITY OF AREA
SHRA/TSRA DEVELOPMENT WILL BE DURING THE DAYLIGHT HOURS TOMORROW. SEE
A REPEAT PATTERN SETTING UP FOR THE NEXT SEVERAL DAYS. 42
&&
.PREV DISCUSSION... /ISSUED 831 PM CDT FRI JUL 13 2012/
UPDATE...
WILL LET FLASH FLOOD WATCH EXPIRE AT 9PM THIS EVENING. SOME MINOR
SHORT TERM CHANGES FOR TEMPS..DEW POINTS...SKY COVER AND REDUCE
OVERNIGHT PCPN CHANCES.
DISCUSSION...
AS PER PAST FEW EVENINGS SHRA/TSRA ARE WINDING DOWN QUICKLY WITH
LOSS OF DAYTIME HEATING. SKY COVERAGE ALSO DECREASING. AREA 00Z
RAOBS STILL HAVE 1.9 TO NEAR 2.0 INCH PWAT VALUES SO THE
ATMOSPHERE REMAINS MOISTURE LADEN. 1000-700MB MEAN TROUGH DID SAG
SOUTHEASTWARD TODAY AS SUGGESTED BY LARGER SCALE GUIDANCE LAST
NIGHT. 18Z GFS AND 12Z ECM BEGIN TO RETREAT THE TROUGH TO THE
NORTHWEST OVER THE WEEKEND. ONE DIFFERENCE IS THAT NAM/GFS
FORECAST SOUNDINGS DO NOT LOOK NEARLY AS UNSTABLE IN THE OVERNIGHT
HOURS BUT BEGIN TO DEVELOPMENT ATTAINABLE CAPE BY MID TO LATE
MORNING. LATEST HRRR AND TX TECH WRF RUNS DO NOT FORECAST
EXPLOSIVE TSRA/HVY RAIN OVERNIGHT. HAVE REDUCED OVERNIGHT
PRECIPITATION CHANCES AND WILL ALLOW FF WATCH TO
EXPIRE ESPECIALLY GIVEN THE REDUCED CHANCE OF OVERNIGHT HVY RAINS
KEEPS A DECENTLY LONG NUMBER OF HOURS OF MOSTLY DRY WEATHER. NEXT
WHICH SHIFT MIGHT NEED TO ISSUE A NEW FF WATCH FOR PORTIONS OF THE
AREA..POSSIBLY MID-MORNING THROUGH THE AFTERNOON. NOT ENOUGH
CONFIDENCE AT THIS POINT TO PINPOINT AREAS FOR POSSIBLE WATCH
GIVEN NO NEWER LARGE SCALE 00Z MODEL GUIDANCE.
NEW ZONES AND PRODUCTS BY 9PM. 04
HYDROLOGY...
ALTHOUGH THE FLASH FLOOD WATCH HAS BEEN ALLOWED TO EXPIRE SEVERAL
CREEKS..RIVERS AND STREAMS ARE IN FLOOD STAGE OR VERY CLOSE.
PLEASE REFER TO RVSHGX AND FLSHGX PRODUCTS FOR FURTHER DETAILS.
THESE ARE ALSO AVAILABLE ON OUR WEB SITE. 04
PREV DISCUSSION... /ISSUED 340 PM CDT FRI JUL 13 2012/
DISCUSSION...
SCATTERED CONVECTION HAS SHIFTED WESTWARD THIS AFTERNOON WITH THE
HEAVIEST ACTIVITY LOCATED ACROSS WESTERN BRAZORIA COUNTY AND ALONG
A LINE FROM NEAR COLUMBUS NORTHWESTWARD TO BURNET. EXPECTING THAT
COVERAGE WILL CONTINUE TO DECREASE ACROSS THE REGION THROUGH THE
EVENING HOURS ALTHOUGH ANY REMAINING THUNDERSTORMS WILL BE CAPABLE
OF PRODUCING BRIEF HEAVY DOWNPOURS...GUSTY WINDS...AND FREQUENT
CLOUD TO GROUND LIGHTNING. THE FLASH FLOOD WATCH WILL REMAIN IN
EFFECT FOR MOST OF SOUTHEAST TEXAS THROUGH 9 PM THIS EVENING.
MAIN CONCERN FOR THIS FORECAST REMAINS THE POTENTIAL FOR
ADDITIONAL RAINFALL ACROSS THE REGION OVER THE WEEKEND. BOTH THE
ECMWF AND GFS RUNS FROM THIS MORNING BEGIN TO DRIFT THE UPPER
LEVEL WEAKNESS BACK TO THE WEST AND HAVE IT OVERHEAD BY LATE
SATURDAY. STILL THINK THAT SATURDAY WILL BE A RELATIVELY DRIER DAY
FOR MUCH OF THE REGION WITH THE HEAVIEST TOTALS MAINLY ACROSS OUR
EASTERN COUNTIES BUT WILL CARRY CHANCE POPS AREAWIDE THROUGH THE
AFTERNOON. WILL KEEP CHANCE POPS IN FOR SUNDAY AS WELL BUT THESE
MAY NEED TO BE RAISED AS THE TROUGH CONTINUES TO TRANSIT THE
REGION.
HEADING INTO THE EXTENDED...THE UPPER LEVEL WEAKNESS THAT HAS
PERSISTED ACROSS THE REGION WILL MOVE WELL WEST OF THE REGION AS
AN INVERTED TROUGH WITH THE UPPER LEVEL RIDGE BEGINNING TO
REESTABLISH ITSELF ACROSS THE CENTRAL PLAINS. THIS WILL HELP TO
LOWER OUR RAIN CHANCES THROUGH THE WEEK BUT WILL CONTINUE TO KEEP
SLIGHT CHANCE TO CHANCE POPS IN THE FORECAST AS HEIGHTS WILL
REMAIN LOW ENOUGH THAT WE COULD SEE A FEW SHOWERS AND
THUNDERSTORMS DEVELOP WITH DAYTIME HEATING EACH AFTERNOON. 38
MARINE...
NO SIGNIFICANT CHANGES TO CURRENT FCST TRENDS. A WEAK SURFACE TROUGH
WILL KEEP A LIGHT WINDS IN PLACE THROUGH THE WEEKEND. THE LINGERING
UPPER LEVEL TROF WILL ALSO KEEP SCATTERED STORMS IN THE FCST THROUGH
THE END OF THE WEEK. BRIEF GUSTY WINDS/ELEVATED SEAS ARE POSSIBLE IN
AND NEAR THE STRONGER STORMS. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 73 90 73 91 73 / 20 50 30 50 20
HOUSTON (IAH) 74 90 73 90 74 / 30 50 20 50 20
GALVESTON (GLS) 82 88 82 89 82 / 30 50 30 40 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...04
AVIATION/MARINE...42
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
315 AM EDT SAT JUL 14 2012
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH THROUGH THE REGION THIS MORNING
BEFORE DISSIPATING. HIGH PRESSURE OFFSHORE WILL BUILD INTO THE
REGION LATER THIS WEEKEND BRINGING A RETURN OF MUCH WARMER
WEATHER BY EARLY NEXT WEEK. A COLD FRONT WILL TRY TO MAKE ITS WAY
INTO AND THROUGH THE HIGH BY THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 255 AM EDT SATURDAY...
WARM FRONT ACROSS THE CENTRAL CWA THIS MORNING WILL LIFT NORTH AND
BASICALLY DISSIPATE BY AFTERNOON AS A GRADUALLY DEEPENING SOUTH/SW
FLOW DEVELOPS AROUND THE RIDGE OFFSHORE. BEHIND THE FRONT WILL SEE A
CONTINUED INFLUX OF WARMER AND MORE HUMID AIR WHICH PROVIDED ENOUGH
HEATING SHOULD SPARK ANOTHER ROUND OF SHRA/TSRA INTO THIS EVENING.
HOWEVER IN THE WAKE OF THE BOUNDARY...FOCUS LIKELY TIED MORE TO
OROGRAPHICS IN THE WEST AND OLD OUTFLOW IN THE EAST...PRODUCING A
MORE SCATTERED NATURE COVERAGE PER LATEST HRRR AND LOCAL WRF SOLNS.
APPEARS DEVELOPING SW FLOW AND HIGHER THETA-E MOUNTAINS SHOULD
SUPPORT BETTER COVERAGE NEAR THE BLUE RIDGE AND PERHAPS THE NW
WHERE WILL BE CLOSEST TO THE RESIDUAL FRONT. THUS MAY INCLUDE SOME
LOW AFTERNOON LIKELY POPS IN SPOTS ALONG THE RIDGES...WITH MAINLY
CHANCE COVERAGE ELSW WITH SOME OF THIS DEVELOPING LATER THIS
MORNING AS HEATING GETS GOING. LATEST FORECAST SOUNDINGS ALSO SHOW
WEAK MID LEVEL STEERING OF AROUND 10 MPH AND VERY MOIST PWATS OF
1.75 INCHES OR BETTER SO SLOW MOVING HEAVY RAINERS A THREAT
ESPCLY IF THINGS BAND UP ALONG THE RIDGES. DEGREE OF CLOUD COVER
TRICKY BY AFTERNOON WITH GUIDANCE SUGGESTING SOME BREAKS BUT THEN
QUICKLY DEVELOP CONVECTION WHICH MAY CURTAIL TEMP RISES. LATEST
MAV MOS LOOKS TOO WARM GIVEN EARLY CLOUDS AND AFTERNOON SHRA WHILE
THE MET TOO SLOW TO EXIT THE WEAK WEDGE. THUS GOING IN BETWEEN AND
CLOSER TO THE ENSEMBLE HIGHS WHICH PUTS THE WEST IN THE 76-82
RANGE AND MAINLY MID/UPR 80S EAST.
UPPER RIDGE OFFSHORE SHIFTS FARTHER WEST OVERNIGHT PUSHING THE
LINGERING DEEPER MOISTURE AXIS ALONG THE WESTERN SLOPES FARTHER
INLAND. THIS ALONG WITH SLIGHTLY HIGHER 5H HEIGHTS SHOULD END MOST
CONVECTION THIS EVENING ALLOWING FOR MOSTLY CLEAR TO PC SKIES
OVERNIGHT WITH SOME PATCHY FOG AROUND...AND ONLY AN ISOLATED SHRA
THREAT FAR WEST. WILL BE QUITE WARM AND MUGGY WITH LOWS 65-72
UNDER A MOIST AND SOUPY ENVIRONMENT IN THE WAKE OF ANY EARLIER
STORMS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
SEVERAL WEATHER FEATURES WILL CONVERGE OVER THE MID ATLANTIC REGION
AND KEEP THE CHANCES FOR SHOWERS AND THUNDERSTORMS IN THE FORECAST
THROUGH EARLY NEXT WEEK. AN UPPER LEVEL TROUGH OVER THE GREAT LAKES
AND A VORTICITY AXIS IN THE OHIO VALLEY WILL SLOWLY MOVE TO THE EAST
THROUGH THE PERIOD. AN UPPER LEVEL RIDGE...CURRENT OVER THE
REGION...WILL DRIFT TO THE SOUTH ALLOWING THE VORTICITY AXIS TO MOVE
OVER THE MOUNTAINS SUNDAY AND THE UPPER LEVEL TROUGH TO MOVE INTO
THE REGION MONDAY AND TUESDAY. WITH THE ADDITION OF SHORT WAVES
COMING AROUND THE UPPER LEVEL RIDGE AND A SURFACE LEE TROUGH IN THE
PIEDMONT...SCATTERED SHOWERS AND THUNDERSTORMS WILL REMAIN IN THE
FORECAST THROUGH THE PERIOD. WILL KEEP THE HIGHEST POPS DURING PEAK
HEATING AND MAINLY OVER THE MOUNTAINS SUNDAY AND MONDAY. ANY STRONG
STORMS THAT DEVELOP DURING THIS PERIOD WILL MOVE SLOW AND COULD
RESULT IN LOCALIZE FLASH FLOODING.
SCATTERED SHOWERS SHOULD HELP COOL AFTERNOON TEMPERATURES...BUT
UNTIL THEY DO...AFTERNOON TEMPERATURES WILL RUN ABOVE NORMAL BY 5F
TO 10F. IF THESE SHOWERS COOLING THE TEMPERATURES...RELATIVE
HUMIDITY WILL INCREASE...RESULTING IN MUGGY AND UNCOMFORTABLE
CONDITIONS. MOS GUIDANCE TEMPERATURES ARE SIMILAR...THERE I DID NOT
STRAY TO FAR FROM THEM.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 300 PM EDT FRIDAY...
BROAD UPPER RIDGE REMAINS OVER THE SOUTHEAST UNITED STATES. RIDGE
FLATTENS ON THURSDAY AND FRIDAY. SURFACE FRONT DROPS THROUGH SOUTH
INTO THE MID ATLANTIC REGION BY FRIDAY. CHANCE OF SHOWERS AND
THUNDERSTORMS WILL IMPROVE THURSDAY AND FRIDAY AHEAD OF THE FRONT.
OTHERWISE NO DISTINCT FEATURES TO HELP ORGANIZE ANY THUNDERSTORMS
TUESDAY AND WEDNESDAY. HOWEVER...AIR MASS WILL BE WARM AND UNSTABLE
WITH 850 MB TEMPERATURES IN THE +18 TO +20 RANGE. WILL KEEP DAILY
PROBABILITY OF AFTERNOON AND EVENING THUNDERSTORMS IN THROUGH THE
PERIOD. TEMPERATURES WILL REMAIN SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1255 AM EDT SATURDAY...
SHOWERS CONTINUE TO SLOWLY FADE OR EXIT THE REGION ATTM AND
SHOULD END BY DAYBREAK IF NOT SOONER. OTRW ANTICIPATE A GRADUAL
TREND TOWARD IFR/MVFR CONDITIONS FOR BOTH CIGS AND VSBYS THROUGH
THE EARLY MORNING HOURS OF SATURDAY. ANY SUB- VFR CONDITIONS
SHOULD IMPROVE TO VFR BY 14-16Z...10AM- NOON...ON SATURDAY.
SHOWERS AND STORMS WILL AGAIN BE POSSIBLE BY THE LATE MORNING TO
EARLY AFTERNOON ON SATURDAY. APPEARS THAT WITH ENOUGH HEATING MAY
HAVE DECENT COVERAGE ESPCLY ACROSS THE MOUNTAINS SO ENOUGH
CONFIDENCE TO INCLUDE AT LEAST A VCTS MENTION OVER THE WEST AND
VCSH OUT EAST IN THE AFTERNOON. THESE STORMS MAY BE SLOW MOVING
WITH PERIODS OF MVFR/IFR POSSIBLE PENDING THE DEGREE OF
ORGANIZATION LATER ON.
THE FRONT WILL CONTINUE TO LIFT NORTH DURING THE REMAINDER OF THE
WEEKEND. SHRA/TSRA COVERAGE WILL CONTINUE TO TREND MORE DIURNAL
AND ALONG THE MOUNTAIN RIDGES. MOST AREAS WILL EXPERIENCE VFR
CONDITIONS OUTSIDE OF THE HEAVIER SHRA/TSRA. LATE NIGHT IFR/MVFR
MOUNTAIN AND RIVER VALLEY FOG WILL BE POSSIBLE.
EARLY NEXT WEEK...HIGH PRESSURE GRADUALLY BUILDS INTO THE AREA
WITH PROGRESSIVELY MILDER TEMPERATURES AND A STRONG CAPPING
INVERSION ALOFT. CONDITIONS WILL BE MAINLY VFR EXPECT BRIEFLY
UNDER THOSE ISOLATED AREAS THAT RECEIVE A MODERATE TO HEAVY SHOWER
OR STORM.
&&
.EQUIPMENT...
NOAA ALL HAZARDS RADIO FOR THE HINTON TRANSMITTER REMAINS OFF THE
AIR DUE TO COMMERCIAL POWER NOT REACHING THE SITE.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/DS
NEAR TERM...JH
SHORT TERM...RCS
LONG TERM...AMS
AVIATION...DS/JH/KK
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS ALBANY NY
1042 AM EDT SAT JUL 14 2012
.SYNOPSIS...
A DISTURBANCE WILL MOVE ON BY TO OUR EAST DURING THE MORNING
HOURS...BRINGING SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS...MAINLY FROM ALBANY SOUTHWARD. SUNSHINE AND HOT
WEATHER WILL RETURN BY AFTERNOON. A STRONGER DISTURBANCE OVER
WISCONSIN WILL BRING A BETTER CHANCE OF MORE SIGNIFICANT SHOWERS AND
POSSIBLY THUNDERSTORMS ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1030 AM...CONVECTION HAS DIMINISHED AS THE COMBINATION OF THE
DEPARTURE FROM THE SHORT WAVE AND INCREASED SUBSIDENCE IN ITS WAKE.
SHORT WAVE RIDING WAS APPROACHING FROM THE WEST WHERE MOSUNNY SKIES
PREVAIL THIS SATURDAY MORNING. ANTICIPATION IS FOR THE CLOUDS TO
DISSIPATE WITH INCREASING AMOUNTS OF SUNSHINE. HOWEVER...WITH THE
DAYTIME HEATING AND SURFACE TEMPS APPROACHING THE CONVECTIVE TEMPS
INTO THE UPPER 80S AND LOWER 90S...EXPECTATION IS FOR ADDITIONAL CU
TO DEVELOP. LATEST RUN OF THE RAP/HRRR SUGGEST SBCAPES WILL AVERAGE
BETWEEN 1K-2K J/KG AS MID LEVEL LAPSE RATES BEING SLIGHTLY BETTER
THAN 6 C/KM IN THE 850-500MB LAYER. IF CONVECTION WERE TO
DEVELOP...THE ELEVATED HEAT SOURCES /TERRAIN/ WOULD LIKELY BE THE
FIRST TO OBSERVE AS SUGGESTED BY THE EXPERIMENTAL HRRR REFLECTIVITY
FORECASTS. SO FOR THIS UPDATE...PLACE SLIGHT CHANCE POPS FOR THE
TERRAIN THIS AFTERNOON AND LEFT THE PREVIOUSLY ADJUSTED MAX TEMPS
ALONE AT THIS TIME.
AS OF 8 AM...HAVE INCREASED POPS ACROSS THE MOHAWK VALLEY...CAPITAL
REGION AND PORTIONS OF THE MID HUDSON VALLEY AS ONGOING CONVECTION
CONTINUES TO REDEVELOP ACROSS THESE AREAS. H2O VAPOR LOOP REVEALS A
SHORT WAVE OVER EASTERN NY THAT WILL CONTINUE TO TRACK EAST INTO NEW
ENGLAND THROUGH THE REMAINDER OF THIS MORNING. THEREAFTER...SHORT
WAVE RIDGING IS EXPECTED WHICH SHOULD DECREASE CONVECTIVE
POTENTIAL...BUT NOT COMPLETELY. THE COMBINATION OF RESIDUAL OUTFLOW
BOUNDARIES ALONG WITH HIGHER DEWPOINTS DUE TO THE RAINFALL AND
PERHAPS DIFFERENTIAL HEATING BOUNDARIES...THERE COULD BE ISOLATED
CONVECTION ONCE AGAIN THIS AFTERNOON DURING MAX HEATING. SPEAKING
OF HEATING...WITH CONSIDERABLE CLOUD COVER AND SOME IMPROVEMENTS ARE
EXPECTED...WE HAVE LOWERED HIGH TEMPS A COUPLE OF DEGREES.
WITH THE RETURN OF SUNSHINE THIS AFTERNOON...AND H850 TEMPS AROUND
+18C...IT LOOKS AS IF WE MAY APPROACH OR EXCEED 90 DEGREES...MID
TO UPPER 80S HIGHER TERRAIN THIS AFTERNOON. HEAT INDICES LOOK TO
APPROACH BUT NOT QUITE REACHING 100 DEGREES. NO HEAT HEADLINES
EXPECTED AT THIS TIME BUT WILL REFERENCE THE HEAT IN THE HWO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
AS OF 615 AM...A STRONGER DISTURBANCE OVER THE GREAT LAKES LOOKS TO
APPROACH OUR REGION LATER TONIGHT...INCREASING CLOUDS. SLIGHTLY
DELAYED POPS TONIGHT AS IT MIGHT TAKE A LITTLE LONGER FOR POSSIBLE
SHOWERS AND THUNDERSTORMS TO REACH THE REGION.
THIS SYSTEM LOOKED A LITTLE MORE PROMISING TO BRING MORE SIGNIFICANT
RAINFALL TO MUCH OF THE REGION. IT CONTAINS A WEAK SIGNATURE OF A H
H850 SPEED MAX (NOSE OF A JET) AS WELL AS A THETA-E RIDGE POKING
INTO OUR REGION. HOWEVER...THE 00Z ECMWF AND THE ESPECIALLY THE
LATEST NAM HAVE BACK OFF THE QPF SOMEWHAT...ESPECIALLY FROM ALBANY
NORTHWARD. PWAT VALUES ARE EXPECTED TO APPROACH 2.00 INCHES.
THAT SAID...WE ACTUALLY RAISED POPS TO LIKELY (60) SOUTH OF
ALBANY...BUT KEPT THE POPS AROUND 50 PERCENT FROM ALBANY NORTHWARD
FOR NOW.
INITIALLY...SHOWALTER VALUES OF THE NAM WERE BELOW 0...IMPLYING
INSTABILITY FROM THE H850 LEVEL UPWARD TONIGHT. LATER...THE VALUES
WERE FORECAST TO BE AROUND ZERO. EITHER WAY...WILL CONTINUE WITH THE
CHANCE OF THUNDER ON SUNDAY.
WITH MORE CLOUDS AND POSSIBLE SHOWERS...LEANED WITH THE LOWER MET
GUIDANCE REGARDING HIGH TEMPERATURES ON SUNDAY. LOOK FOR HIGH
TEMPERATURES MAINLY IN THE 80S IN THE VALLEYS...WITH MID TO UPPER
70S ACROSS THE HIGHER TERRAIN. MID LEVEL LAPSE RATES ARE MODEST
AROUND 5.5C/KM. HOWEVER...DEEP SHEAR OF UP TO 30KTS AND ANY HEATING
DURING THE AFTERNOON...COULD SUPPORT THUNDERSTORMS CAPABLE OF
PRODUCING GUSTY SUB-SEVERE WINDS DURING THE AFTERNOON.
THE TROUGH LOOKS TO MOVE EAST EVEN BY LATE AFTERNOON. MOST IF NOT
ALL CONVECTIVE ACTIVITY LOOKS TO DEPART DURING THE EVENING HOURS. IN
THE WAKE OF THE SYSTEM...THE SKY LOOKS TO CLEAR. HOWEVER...WITH
LIGHT WIND...THIS COULD THE STAGE FOR SOME PRETTY GOOD PATCHY FOG.
HAVE INTRODUCED PATCHY FOG INTO THE GRIDS.
MONDAY LOOKS TO SEE A RETURN TO HOT CONDITIONS. HIGH PRESSURE WILL
BUILD IN FROM THE OHIO VALLEY. ONCE AGAIN TEMPERATURES LOOK TO CRACK
90 IN MANY LOCATIONS...EXCEPT MID TO UPPER 80S ACROSS THE MOUNTAINS.
OVERNIGHT LOWS SATURDAY AND SUNDAY NIGHT NIGHT LOOK TO BE IN THE 65
TO 70 RANGE.
OVERALL WENT WITH A MET/MAV BLEND.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE EXTENDED FORECAST CONTINUES WITH THE HEAT AND HUMIDITY ACROSS
THE REGION INTO MIDWEEK...THEN THERE IS A GENERAL CONSENSUS WITH THE
MEDIUM RANGE GUIDANCE AND HPC THAT A COLD FRONT WILL MOVE SOUTHWARD
ACROSS THE REGION LATE TUES NIGHT AND WED...WITH HIGH PRESSURE
BUILDING IN FOR THURSDAY AND FRIDAY WITH SEASONABLE TEMPERATURES AND
COMFORTABLE LEVELS OF HUMIDITY.
A WEAK SURFACE RIDGE AXIS WILL BUILD INTO THE REGION MONDAY NIGHT...
AND THIS SHOULD BE ENOUGH TO SUPPRESS ANY SCT CONVECTION MONDAY
NIGHT AND TUESDAY MORNING. AS A LOW PRESSURE SYSTEM TRACKS EAST
ACROSS SOUTHERN QUEBEC TUESDAY AND TUESDAY NIGHT...THE COLD FRONT
WILL LINE UP WEST TO EAST JUST TO THE NORTH OF THE REGION...AND
RESULT IN A SLIGHT OR LOW CHANCE FOR SHWRS/TSTMS TUESDAY
AFTERNOON...WHICH WILL GRADUALLY PUSH FURTHER SOUTH TUESDAY NIGHT.
THE COLD FRONT WILL CONTINUE TO SUBSIDE SOUTH ON WEDNESDAY...AND BE
SOUTH OF THE ENTIRE FORECAST AREA BY WEDNESDAY EVENING. HAVE
FORECAST 35 TO 50 PERCENT CHANCE OF SHOWERS/TSTMS LATE TUESDAY NIGHT
THRU WEDNESDAY ACROSS THE REGION...THEN ONLY SLIGHT CHANCE TO LOW
CHANCE POPS LINGERING OVER THE EXTREME SOUTH WEDNESDAY EVENING.
AFTER THAT...MAINLY CLEAR SKIES AND DRY WEATHER ARE FORECAST AS THE
CANADIAN HIGH PRESSURE SYSTEM BUILDS INTO THE REGION.
TEMPS WILL START OUT VERY WARM WITH LOWS MONDAY NIGHT IN THE 60S.
HIGHS TUESDAY WILL BE IN THE MID 80S TO MID 90S WITH HEAT INDICES
LIKELY REACHING THE MID AND UPPER 90S IN VALLEY AREAS FROM THE THE
CAPITAL DISTRICT SOUTH. LOWS TUESDAY NIGHT WILL BE IN THE MID 60S TO
LOWER 70S. HIGHS WEDNESDAY WILL SHOW A WIDE RANGE WITH HIGHS IN THE
UPPER 70S OVER THE ADIRONDACK ZONES DUE TO THE EARLIER FRONTAL
PASSAGE PASSAGE...RANGING TO THE LOWER 90S IN THE MID HUDSON VALLEY.
ANY HEAT INDICES IN THE MID OR UPPER 90S ON WEDNESDAY WILL BE
CONFINED TO THE MID HUDSON VALLEY AND SOUTHERN LITCHFIELD COUNTY.
MUCH MORE SEASONABLE AND COMFORTABLE AIR WILL ARRIVE FOR WEDNESDAY
NIGHT WITH LOWS IN THE 50S TO LOWER 60S. HIGHS THURSDAY AND FRIDAY
IN THE MID 70S TO MID 80S. LOWS THURSDAY NIGHT ALSO IN THE 50S TO
LOWER 60S.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS A WEAK UPPER LEVEL TROF LIFTS EAST-NORTHEAST ACROSS THE REGION
THIS MORNING ...SHOWERS AND THUNDERSTORMS OVER THE KALB TAF SITE
/INCLUDING THE MOHAWK VALLEY AND CAPITAL REGION/ WILL LINGER INTO
THE EARLY PART OF THE TAF PERIOD (UNTIL ABOUT 15Z). THE SHOWERS MAY
REACH KPSF AND HAVE INDICATED A TEMP GROUP THERE FOR SHOWERS THROUGH
14Z. PROBABILITY OF SHOWERS REMAIN TO LOW AT THIS TIME TO WARRANT
ANY MENTION AT KGFL OR KPOU FOR THIS TAF PERIOD.
BESIDES THE EARLY MORNING SHOWERS/TSTMS...EXPECT VFR CONDITIONS AT
THE TAF SITES AFTER 14Z FOR MOST OF THE REST OF THE TAF PERIOD
ENDING AT 12Z SUNDAY...BUT THERE COULD BE SOME MVFR FOG LATE TONIGHT.
SURFACE WINDS WILL GENERALLY BE WEST OR SOUTHWEST AT 8 KTS OR
LESS....AND MAINLY CALM OR LIGHT AND VARIABLE DURING NIGHTTIME HOURS.
OUTLOOK...
SUN-WED...VFR/MVFR. ISOLD-SCT SHOWERS/TSTMS.
&&
.FIRE WEATHER...
A WEAK DISTURBANCE WILL SLIDE TO OUR SOUTH EARLY TODAY...WITH A
SHOWER OR THUNDERSTORM POSSIBLE...MAINLY SOUTH OF INTERSTATE 90
DURING THE MORNING HOURS. MOST AREAS WILL FAIL TO RECEIVE 0.25
INCHES OF RAINFALL.
ON SUNDAY...A STRONGER DISTURBANCE WILL MOVE FROM THE GREAT LAKES
ACROSS OUR REGION...BRINGING SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS AND HUMID CONDITIONS. THIS SYSTEM HAS THE POTENTIAL TO
BRING 0.25 INCHES OR MORE...MAINLY SOUTH OF ALBANY.
HIGH PRESSURE WILL BUILD EAST FROM THE OHIO VALLEY INTO OUR REGION
ON MONDAY...BRINGING DRY HOT WEATHER.
RELATIVE HUMIDITY VALUES WILL DROP TO MODERATE LEVELS THIS
AFTERNOON...RECOVER TO 80 TO 100 PERCENT TONIGHT...AND REMAIN
ELEVATED 60 TO 80 PERCENT MOST OF SUNDAY.
HUMIDITY VALUES WILL REMAIN ELEVATED THROUGH MONDAY...DESPITE NO
MORE RAIN EXPECTED.
ONLY ISOLATED THUNDERSTORMS ARE EXPECTED TUESDAY WITH POSSIBLY MORE
SIGNIFICANT ACTIVITY ON WEDNESDAY.
THE SURFACE WIND WILL BE LIGHT AND VARIABLE AND GENERALLY 10 MPH OR
LESS. LOCALLY HIGHER GUSTS ARE POSSIBLE WITH ANY THUNDERSTORM.
&&
.HYDROLOGY...
NO SIGNIFICANT HYDRO PROBLEMS ARE EXPECTED FOR THE NEXT FIVE DAYS.
DURING THE PAST MONTH...ALBANY INTERNATIONAL AIRPORT HAD ONLY
RECEIVED 0.33 INCHES OF RAINFALL. AT MY COCORAHS SITE (0.5SW ALBANY)
I HAD ONLY RECEIVED 0.12 INCHES!
SCATTERED SHOWERS AND THUNDERSTORMS...MAINLY SOUTH OF ALBANY EARLY
ON SATURDAY...COULD PRODUCE VERY LOCALIZED AMOUNTS OVER HALF AN
INCH. HOWEVER...RAINFALL BASIN AVERAGE WILL REMAIN WELL BELOW 0.25
INCHES WITH NO EFFECT ON THE SLUGGISH WATERSHEDS.
THERE IS POTENTIAL FOR A AVERAGE RIVER BASIN QUARTER INCH OR MORE OF
RAINFALL...MAINLY SOUTH OF ALBANY ON SUNDAY. SOME LOCALITIES COULD
RECEIVE OVER AN INCH OF RAINFALL FROM DOWNPOURS. FURTHER
NORTH...FROM ALBANY NORTHWARD...IT LOOKS AS LESS THAN A QUARTER OF
AN INCH OF RAIN WILL FALL ACROSS THE RIVER BASIN.
EITHER WAY...EVEN THESE RAIN WILL BE ONLY MINOR RELIEF FROM OUR
INCREASE DRY SPELL...WITH NO RISES ON ANY RIVERS EXPECTED.
AFTER SUNDAY...OUR NEXT CHANCE OF ANY REAL SHOWERS AND STORMS WILL
BE LATE TUESDAY OR EARLY WEDNESDAY WITH THE PASSAGE OF A PRETTY
STRONG COLD FRONT FOR THE TIME OF YEAR.
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...HWJIV
NEAR TERM...HWJIV/BGM
SHORT TERM...HWJIV
LONG TERM...GJM
AVIATION...GJM/BGM
FIRE WEATHER...HWJIV
HYDROLOGY...SNYDER
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
1100 AM CDT SAT JUL 14 2012
.DISCUSSION...
1100 AM CDT
GOING GENERAL FORECAST IDEA OF SCATTERED THUNDERSTORMS DEVELOPING
THIS AFTERNOON REMAINS SUPPORTED BY LATEST TRENDS. ALL IN ALL JUST
MINOR TWEAKS MADE MAINLY BASED ON THERMAL INFLUENCE OF EARLY
MORNING CONVECTION.
FAIRLY AMPLIFIED UPPER TROUGH FOR SUMMERTIME SEEN ON THE WATER
VAPOR SATELLITE LATE THIS MORNING REMAINS LITTERED WITH EMBEDDED
VORTICITY MAXIMA. ONE SUCH IMPULSE LIFTING NORTHEAST FROM CENTRAL
IL EARLY THIS MORNING HAS BECOME SHEARED OUT AND THE ASSOCIATED
SHOWERS AND EMBEDDED CONVECTION WEAKENED RATHER QUICKLY AS A
RESULT. THE 850-700MB CONVERGENT ZONE/TROUGH MENTIONED IN PREV
DISCUSSION IS STILL IN PLACE ACROSS THE CENTRAL FORECAST AREA IN
THE WAKE OF THESE SHOWERS. OUTFLOW FROM THE DECAYED CONVECTION SEEN
ON VISIBLE SATELLITE AND RADAR HAS PUSHED EAST AND IS LOCATED
FROM PORTER COUNTY INDIANA SOUTHWEST TOWARD CHAMPAIGN-URBANA.
CELLS HAVE STARTED TO DEVELOP ON AND AHEAD OF THE SOUTHERN PORTION
OF THIS BOUNDARY WHERE THE CAP LOOKS TO HAVE ERODED. THE LOW-LEVEL
COLD POOL BEHIND THE OUTFLOW BOUNDARY ACROSS MUCH OF THE EASTERN
HALF OF THE FORECAST AREA IS SHALLOW PER PROFILER WIND FIELD...AND
1000 TO 1500 J/KG OF MUCAPE EXISTS ABOVE THIS LAYER PER ILX
SOUNDING AND RAP ANALYSIS. SO SCATTERED REDEVELOPMENT FROM WHERE
EARLIER CONVECTION DECAYED/ALONG THE 850-700MB CONVERGENT AXIS AND
EASTWARD REMAINS FAVORED THIS AFTERNOON. A LAKE BREEZE COMPONENT
SHOULD ONLY AID THIS. DOWNDRAFT CAPE VALUES OF 700-1000 J/KG ON
RAP ANALYSIS WOULD FAVOR SOME STRONGER DOWNDRAFTS WITHIN STORMS.
BACK TO THE WEST...CONVECTION AHEAD OF THE SURFACE BOUNDARY ACROSS
NORTHEAST IA CONTINUES TO TRACK SOUTHEAST AIDED BY A BETTER
DEFINED SHORT WAVE ACROSS WESTERN WI MOVING SOUTHEAST. INHIBITION
IMMEDIATELY AHEAD OF THIS APPEARS TO BE VERY MINIMAL IF ANY PER
MODIFIED 12Z DVN SOUNDING. SO EXPECT THIS AREA TO CONTINUE TO
MIGRATE SOUTHEAST WITH SOME ADDITIONAL DEVELOPMENT AHEAD AS AREAS
OF NORTHWEST/NORTH CENTRAL IL DESTABILIZE. THIS WOULD FAVOR THE
WESTERN FORECAST AREA FOR SOME SCATTERED CONVECTION...ESPECIALLY
IN THE MID TO LATE AFTERNOON AND POTENTIALLY EARLY EVENING.
HAVE LOWERED TEMPERATURES SOME NEAR PONTIAC AND STREATOR WHERE
MID CLOUD LOOKS TO BE MOST PERSISTENT AND RESIDUAL COLD POOL WILL
KEEP TEMPERATURES SLOWER TO WARM. MUCH OF THE CHICAGO AREA LOOKS
TO REACH NEAR 90 WITH ONLY LIMITED LAKE INFLUENCE DUE TO 5-10 MPH
OFFSHORE COMPONENT AT PRESENT.
MTF
&&
.PREV DISCUSSION...
331 AM CDT
PRIMARY FORECAST CHALLENGES THIS MORNING ARE PRECIP/CONVECTIVE
TRENDS TODAY FOLLOWED BY A SHORTER AND LESS INTENSE BOUT OF HEAT
THAN WHAT WE SAW LAST WEEK.
UPPER TROUGH OVER THE MIDDLE AND UPPER MISSISSIPPI VALLEY IS SLOWING
MOVING EAST THIS MORNING WITH WATER VAPOR IMAGERY SHOWING SEVERAL
SMALLER VORTICITY MAXIMA EMBEDDED WITHIN THIS TROUGH. THE RATHER
WEAK AND SOMEWHAT ILL DEFINED FORCING IS RESULTING IN FAIRLY LOW
CONFIDENCE IN PRECIP TRENDS THE NEXT 24 HOURS. SOME STORMS ARE
FIRING UP NOW IN VICINITY OF 850MB TROUGH/CONVERGENCE AXIS. LATEST
RAP GUIDANCE SUGGESTS THAT THIS CONVERGENCE WILL WEAKEN THIS MORNING
WHICH IF IT VERIFIES WOULD ALSO LIKELY SPELL THE SLOW DEMISE OR AT
LEAST WEAKENING OF THIS CURRENT CONVECTION.
FAIRLY EXPANSIVE AREA OF WHAT APPEARS TO BE ALTO STRATUS OVER WESTERN
IL/EASTERN MO IS SLOWLY PROGRESSING EASTWARD AND WILL LIKELY RETARD
HEATING TODAY LIMITING INSTABILITY. WHERE MIXED SUNSHINE DOES OCCUR
EXPECT SUFFICIENT SURFACE BASED INSTABILITY TO DEVELOP TO SUPPORT
RENEWED SCATTERED THUNDERSTORM DEVELOPMENT THIS AFTERNOON...WHICH
SEEMS LIKE IT MAY TEND TO FAVOR OUR EASTERN CWA AND POTENTIALLY
ALONG LAKE BREEZE AGAIN THIS AFTERNOON. CONVECTION LIKELY TO
GRADUALLY WANE AND SHIFT EASTWARD OUT OF THE AREA TONIGHT AS TROUGH
MIGRATES EASTWARD.
UPPER RIDGE THEN BEGINS TO BUILD INTO THE AREA WHICH SHOULD RESULT
IN DRIER AND HOT CONDITIONS SUNDAY THROUGH TUESDAY. BY MONDAY AND
TUESDAY MID TO UPPER 90S LOOK LIKE A GOOD BET WITH EVEN A CHANCE OF
ISOLATED SPOTS NEARING THE CENTURY MARK. WEAK COLD FRONT LIKELY TO
SLOWLY SAG SOUTHWARD ACROSS THE AREA TUESDAY NIGHT INTO WEDNESDAY
BRINGING SOMEWHAT COOLER CONDITIONS...ESPECIALLY NEAR THE LAKE...AS
WELL AS AN INCREASED THREAT OF AT LEAST SOME SHOWERS AND
THUNDERSTORMS. DRIER CONDITIONS ARE THEN EXPECTED TOWARD THE END OF
THE WEEK AS FRONT SETTLES SOUTH OF THE AREA. NO STRONG PUSH OF
COOLER AIR BEHIND THE FRONT SO WOULD EXPECT TEMPS TO REMAIN SLIGHTLY
ABOVE AVERAGE.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* SHRA/TSRA IN THE AREA WEAKENING THROUGH THE MORNING AND
REDEVELOPING BY EARLY AFTERNOON.
* LIGHT WESTERLY WINDS BECOMING SOUTHWESTERLY BY EARLY AFTERNOON.
SOME VARIABILITY THROUGH THE MORNING DUE TO SHRA IN THE AREA.
* POTENTIAL FOR LAKE BREEZE BOUNDARY TO CROSS THE TERMINALS AND
SHIFT WINDS TO EAST-SOUTHEAST THIS AFTERNOON.
PAW
//DISCUSSION...UPDATED 12Z...
FORECAST CONCERN CONTINUES TO BE SHRA/TSRA THROUGH THE DAY. AN
UPPER TROUGH AND ASSOCIATED IMPULSES SLOWLY MOVING ACROSS THE
REGION WILL CONTINUE TO SUPPORT ON AND OFF TSRA DEVELOPMENT
THROUGH THE DAY. CURRENT ACTIVITY FOCUSED FROM JUST NORTH OF ORD
BACK TO VYS TO PIA WILL CONTINUE TO MOVE SLOWLY EAST-NORTHEASTWARD
THIS MORNING BUT MAY START TO FADE IN INTENSITY AND COVERAGE AS IT
APPROACHES THE CHI AREA TERMINALS IN THE NEXT 1-2 HRS. AS
INSTABILITY BUILDS INTO THE AFTERNOON THE UPPER FORCING WILL
CONTINUE RESULTING IN ISOLD-SCT TSRA DEVELOPMENT WHICH WOULD
LIKELY BE FOCUSED ACROSS NORTHEAST IL AND NORTHWEST INDIANA. IN
ADDITION TO THE UPPER TROUGH...A LAKE BREEZE MAY BE ABLE TO FORM
AND WORK INLAND OFFERING AN ADDITIONAL FOCUS FOR TSRA.
HOWEVER...THE LAKE BREEZE MAY NOT DEVELOP GIVEN POTENTIAL CLOUD
COVER AND OUTFLOW FROM CURRENT ACTIVITY. IF THE CURRENT ACTIVITY
CAN DIMINISH THEN THERE MAY BE A SEVERAL HOUR BREAK IN ACTIVITY
DURING THE MID/LATE MORNING BEFORE THE NEXT ROUND OF FORCING
MECHANISMS DRAWS NEARER AND INSTABILITY BUILDS. GIVEN THE GOOD
POTENTIAL FOR TSRA OCCURRENCE THROUGH AT LEAST LATE AFTERNOON BUT
THE UNCERTAINTY IN COVERAGE AND HOW DIRECTLY THE TERMINALS WILL BE
AFFECTED...WILL INCLUDE AN EXTENDED PERIOD OF VCTS IN THE TAF AND
ADD DETAIL WITH PREVAILING/TEMPO TSRA AS THINGS BECOME MORE CLEAR
IN THE NEAR TERM. IT IS POSSIBLE THAT SHRA/TSRA ACTIVITY FESTERS
ACROSS THE AREA THROUGH MOST OF THE DAY.
WINDS WILL BE GENERALLY LIGHT AND VARIABLE THROUGH THE MORNING BUT
OUTFLOW FROM THE EARLIER STORMS HAS TURNED THEM NORTHWESTERLY
ACROSS MUCH OF THE CHI METRO AREA. THIS WILL LIKELY BE SHORT LIVED
WITH WINDS TURNING VARIABLE BEFORE TOO LONG. EXPECT A LIGHT
SOUTHWEST DIRECTION TO TAKE OVER LATE THIS MORNING OR EARLY THIS
AFTERNOON. OUTFLOW FROM ANY STORMS THAT DO CROSS THE AREA WILL
LIKELY RESULT IN ERRATIC WIND DIRECTION AND SPEEDS WITH FAIRLY
STRONG GUSTS POSSIBLE FROM THE STRONGEST STORMS.
SHRA/TSRA POTENTIAL CONTINUES THIS EVENING BUT HAVE LITTLE
CONFIDENCE IN HOW HIGH THE POTENTIAL IS. WILL LEAVE ANY MENTION OF
SHRA/TSRA OUT OF THE TAFS FOR THE EVENING UNTIL CONFIDENCE GROWS
AND PRECIP POTENTIAL INCREASES.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM CONFIDENCE THAT SHRA/TSRA WILL REDEVELOP BY EARLY
AFTERNOON.
* MEDIUM CONFIDENCE IN PREVAILING WIND DIRECTION. MEDIUM
CONFIDENCE THAT A LAKE BREEZE WILL DEVELOP. LOW CONFIDENCE IN
WHETHER IT MOVES INLAND FAR ENOUGH TO REACH THE TERMINALS.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT THROUGH TUESDAY...VFR.
TUESDAY NIGHT AND WEDNESDAY...CHANCE OF TSRA...OTHERWISE VFR.
THURSDAY AND FRIDAY...VFR.
MDB
&&
.MARINE...
303 AM CDT
HIGH PRESSURE REMAINS SPRAWLED ACROSS THE EASTERN U.S. WITH LOW
PRESSURE OVER WESTERN HUDSON BAY EXTENDING INTO THE EASTERN
DAKOTAS/WESTERN MINNESOTA. SOUTHERLY WINDS WILL CONTINUE ACROSS LAKE
MICHIGAN TODAY WITH THE EXCEPTION OF WINDS TURNING ONSHORE OVER THE
FAR SOUTHERN PART OF THE LAKE. THE STRONGEST WINDS WILL BE ACROSS
THE NORTHERN PART OF THE LAKE TODAY AS THE PRESSURE GRADIENT
TIGHTENS AHEAD OF THE APPROACHING LOW. THE LOW WILL CROSS THE LAKE
TONIGHT TURNING WINDS MORE WESTERLY AND NORTHWESTERLY INTO SUNDAY
MORNING BUT A SHIFT TO THE SOUTHWEST IS EXPECTED BY SUNDAY AFTERNOON
AS HIGH PRESSURE RETURNS. ANOTHER SURFACE LOW WILL MOVE FROM THE
DAKOTAS TO LAKE SUPERIOR MONDAY AND MONDAY NIGHT. THE PRESSURE
GRADIENT WILL TIGHTEN UP AHEAD OF THIS LOW MONDAY NIGHT AND LATEST
INDICATIONS ARE THAT GUSTS COULD PUSH 30 KT ACROSS THE NORTHERN
THIRD OR SO OF THE LAKE MONDAY EVENING. WINDS WILL THEN TURN NORTH
AND NORTHEAST AS THE LOW PASSES AND A COOL FRONT PUSHES SOUTHWARD
LATE TUESDAY OR EARLY WEDNESDAY. WINDS SHOULD REMAIN ELEVATED BEHIND
THE LOW WITH SPEEDS GENERALLY IN THE 15 TO 20 KT RANGE INTO
WEDNESDAY NIGHT. HIGH PRESSURE WILL THEN REMAIN ACROSS THE LAKE INTO
THE END OF THE WEEK KEEPING LIGHTER WINDS IN PLACE.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1022 AM CDT SAT JUL 14 2012
.UPDATE...
LINE OF STORMS SAGGING INTO NW CWA ATTIM. HAVE RAISED POPS
MAINLY N/NW SECTIONS REST OF TDY WHERE BETTER UPPER SUPPORT
PROGGED IN FORM OF MID LEVEL SHORTWAVE. ISOLD SEVERE STORM
WITH STRONG WINDS TO 60 MPH AND HAIL TO AROUND QUARTER SIZE
NOT OUT OF QUESTION IN MAINLY PULSE TYPE ENVIRONMENT. WILL
CONTINUE TO MONITOR TRENDS FOR ANY ADDITIONAL UPDATES TO FCST.
&&
.PREV DISCUSSION... /ISSUED 651 AM CDT SAT JUL 14 2012/
UPDATE...
THE FCST WILL BE UPDATED SHORTLY TO REFLECT CURRENT TRENDS.
CONVECTION EAST OF THE MISSISSIPPI IS GENERALLY SUPPORTED BY LIFT
AHEAD OF THE FIRST SHORTWAVE CROSSING THE MISSISSIPPI. THIS
CONVECTION IS SLOWLY DISSIPATING AND SHOULD END OR EXIT THE CWFA
AROUND MID MORNING. THE NEXT VORT MAX/SHORTWAVE OVER NORTHERN IOWA
WILL DROP SOUTHEAST DURING THE MORNING AND HELP INITIATE NEW
CONVECTION BY LATE MORNING AND CONTINUING THROUGH THE AFTERNOON.
BASED ON FCST SOUNDINGS...THE DIURNAL CONVECTION SHOULD BE FAIRLY
HIGH BASED WHICH COULD PRODUCE LOCALLY GUSTY WINDS. 08
AVIATION...
MVFR AND SPOTTY IFR VSBYS WILL IMPROVE TO VFR BY 15Z/14. OTHERWISE
VFR CONDITIONS WILL BE SEEN THROUGH 06Z/15. VCSH WILL SLOWLY END
PRIOR TO 18Z WITH NEW CONVECTION STARTING AROUND 18Z/14 AND
CONTINUING THROUGH SUNSET. VCTS WAS ADDED TO ALL TAF SITES FOR THE
DIURNAL CONVECTION. CIGS WITH CONVECTION SHOULD REMAIN VFR BUT
BRIEF MVFR VSBYS WILL BE POSSIBLE. AFT 06Z/15 LIGHT WINDS SHOULD
ALLOW MVFR AND POSSIBLY IFR CONDITIONS TO DVLP. 08
PREV DISCUSSION... /ISSUED 319 AM CDT SAT JUL 14 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS SEVERAL SUBTLE TROFS FROM LAKE MICHIGAN BACK
INTO MINNESOTA WITH A COLLAPSING MESOHIGH NEAR KRST. DEW POINTS WERE
GENERALLY IN THE 60S WITH 70S IN THE DEEP SOUTH AND LOWER OHIO
VALLEY. RADAR TRENDS OVER THE PAST SEVERAL HOURS SHOWS OVERALL
CONVECTION IS SLOWLY DISSIPATING.
SHORT TERM...TODAY AND TONIGHT...
PRECIPITATION SINCE MIDNIGHT HAS EITHER ENDED OR DIMINISHED TO
SPRINKLES/ISOLATED SHRA. EAST OF THE MISSISSIPPI ELEVATED CONVECTION
HAS PERSISTED OR DEVELOPED. RAP TRENDS SHOW THE CONVECTION IS MAINLY
ASSOCIATED WITH SPEED/MOISTURE CONVERGENCE AT 850MB IN RELATIVELY
STRONG LIFT AHEAD OF THE VORT MAX THAT IS ALONG THE MISSISSIPPI. RAP
TRENDS INDICATE THAT THIS ELEVATED CONVECTION WILL PERSIST THE
REMAINDER OF THE NIGHT AND SHOULD DISSIPATE OR EXIT THE CWFA AROUND
MID MORNING.
WEST OF THE MISSISSIPPI SPRINKLES OR ISOLATED ELEVATED CONVECTION
WILL PERSIST OR POSSIBLY DEVELOP AS THE NEXT VORT MAX DROPS INTO THE
TROF FROM NORTHERN IOWA.
FROM LATE MORNING AND CONTINUING INTO THE AFTERNOON...DIURNAL
HEATING WILL ALLOW NEW CONVECTION TO BREAK OUT ACROSS THE CWFA.
BASED ON THE PROJECTED LOCATION OF THE VORT MAXES AND NEGATIVE THETA
E LAPSE RATES...AREAS ALONG/EAST OF THE MISSISSIPPI SHOULD HAVE THE
BETTER CHANCES OF SEEING CONVECTION. THUS THE HIGHER POPS WILL BE
ALONG/EAST OF THE MISSISSIPPI FROM LATE MORNING THROUGH THE
AFTERNOON.
CONVECTION THAT DEVELOPS DURING THE AFTERNOON WILL PERSIST INTO THE
EVENING AND SLOWLY DISSIPATE WITH SUNSET. AFTER MIDNIGHT GENERALLY
DRY CONDITIONS SHOULD BE SEEN WITH SUBSIDENCE BEHIND THE DEPARTING
SHORT WAVE AND BUILDING HEIGHTS. ..08..
LONG TERM...SUNDAY THROUGH FRIDAY...
HEAT AND MORE HUMID CONDITIONS WILL RETURN TO THE REGION FOR THE
FIRST HALF OF THE WEEK AS THE WESTERN U.S. UPPER RIDGE EDGES EAST
INTO THE PLAINS. THE DEVELOPING UPPER RIDGE WILL KEEP THE AREA DRY
SUNDAY AND MONDAY. WITH INCREASING SOUTHERLY FLOW AND WAA TEMP
WILL TOP OUT IN THE LOW TO MID 90S SUNDAY AND MAINLY MID 90S FOR
MONDAY. HELD DEW POINTS IN THE MID/UPPER 60S BOTH DAYS WHICH WILL
SUPPORT HEAT INDEX VALUES IN THE 95 TO AROUND 100 RANGE BOTH DAYS.
TUESDAY INTO THURSDAY A DEVELOPING TROF OVER GREAT LAKES AND NEW
ENGLAND WILL SENT A COLD FRONT SOUTH THROUGH THE REGION. THE FRONT
WILL TAKE THE EDGE OFF THE EARLY WEEK HEAT AND IT WILL ALSO
PROVIDE A CHANCE OF RAIN FOR THE REGION. THE FORECAST WAS SKEWED
TOWARD THE ECMWF WHICH BRINGS THE FRONT THROUGH SLOWER THAN THE
OTHER MODELS...ESPECIALLY THE GFS. THE SLOWER MOVEMENT SEEMS
REASONABLE WITH THE FRONT MOVING INTO THE UPPER RIDGE. ALSO MODELS
ARE SHOWING WARM MID LEVELS ALONG AND AHEAD OF THE BOUNDARY
SUGGESTING THE WARM SECTOR WILL BE CAPPED. WITH ALL THE PRECIP
EXPECTED TO BE POST FRONTAL HAVE KEPT TUESDAY DRY AND LIMITED POPS
TUESDAY NIGHT TO THE NORTH HALF. LOW CHANCE POP WERE MAINTAINED
OVER THE ENTIRE AREA WEDNESDAY THEN STARTED TO DRY THE FORECAST OUT
FROM NORTH TO SOUTH WEDNESDAY NIGHT INTO FRIDAY AS THE BOUNDARY PUSHES
FAR ENOUGH SOUTH. WITH THE WARM MID LEVEL TEMPERATURES IN PLACE
AND FORCING ALONG AND NORTH OF THE FRONT REMAINING WEAK ANY
SHRA/TSRA OCCURRING WITH THIS SYSTEM SHOULD BE SCATTERED.
THE FRONT WILL ALSO BRING SOME SLIGHTLY COOLER TEMPERATURES TO THE
AREA FOR MID TO LATE WEEK. HEAT INDEX VALUES AROUND 100 ARE
EXPECTED OVER THE ENTIRE AREA TUESDAY BUT SHOULD BE LIMITED TO THE
SOUTH HALF OF THE AREA WEDNESDAY AND THURSDAY.
DLF
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
651 AM CDT SAT JUL 14 2012
.UPDATE...
THE FCST WILL BE UPDATED SHORTLY TO REFLECT CURRENT TRENDS.
CONVECTION EAST OF THE MISSISSIPPI IS GENERALLY SUPPORTED BY LIFT
AHEAD OF THE FIRST SHORTWAVE CROSSING THE MISSISSIPPI. THIS
CONVECTION IS SLOWLY DISSIPATING AND SHOULD END OR EXIT THE CWFA
AROUND MID MORNING. THE NEXT VORT MAX/SHORTWAVE OVER NORTHERN IOWA
WILL DROP SOUTHEAST DURING THE MORNING AND HELP INITIATE NEW
CONVECTION BY LATE MORNING AND CONTINUING THROUGH THE AFTERNOON.
BASED ON FCST SOUNDINGS...THE DIURNAL CONVECTION SHOULD BE FAIRLY
HIGH BASED WHICH COULD PRODUCE LOCALLY GUSTY WINDS. ..08..
&&
.AVIATION...
MVFR AND SPOTTY IFR VSBYS WILL IMPROVE TO VFR BY 15Z/14. OTHERWISE
VFR CONDITIONS WILL BE SEEN THROUGH 06Z/15. VCSH WILL SLOWLY END
PRIOR TO 18Z WITH NEW CONVECTION STARTING AROUND 18Z/14 AND
CONTINUING THROUGH SUNSET. VCTS WAS ADDED TO ALL TAF SITES FOR THE
DIURNAL CONVECTION. CIGS WITH CONVECTION SHOULD REMAIN VFR BUT
BRIEF MVFR VSBYS WILL BE POSSIBLE. AFT 06Z/15 LIGHT WINDS SHOULD
ALLOW MVFR AND POSSIBLY IFR CONDITIONS TO DVLP. ..08..
&&
.PREV DISCUSSION... /ISSUED 319 AM CDT SAT JUL 14 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS SEVERAL SUBTLE TROFS FROM LAKE MICHIGAN BACK
INTO MINNESOTA WITH A COLLAPSING MESOHIGH NEAR KRST. DEW POINTS WERE
GENERALLY IN THE 60S WITH 70S IN THE DEEP SOUTH AND LOWER OHIO
VALLEY. RADAR TRENDS OVER THE PAST SEVERAL HOURS SHOWS OVERALL
CONVECTION IS SLOWLY DISSIPATING.
SHORT TERM...TODAY AND TONIGHT...
PRECIPITATION SINCE MIDNIGHT HAS EITHER ENDED OR DIMINISHED TO
SPRINKLES/ISOLATED SHRA. EAST OF THE MISSISSIPPI ELEVATED CONVECTION
HAS PERSISTED OR DEVELOPED. RAP TRENDS SHOW THE CONVECTION IS MAINLY
ASSOCIATED WITH SPEED/MOISTURE CONVERGENCE AT 850MB IN RELATIVELY
STRONG LIFT AHEAD OF THE VORT MAX THAT IS ALONG THE MISSISSIPPI. RAP
TRENDS INDICATE THAT THIS ELEVATED CONVECTION WILL PERSIST THE
REMAINDER OF THE NIGHT AND SHOULD DISSIPATE OR EXIT THE CWFA AROUND
MID MORNING.
WEST OF THE MISSISSIPPI SPRINKLES OR ISOLATED ELEVATED CONVECTION
WILL PERSIST OR POSSIBLY DEVELOP AS THE NEXT VORT MAX DROPS INTO THE
TROF FROM NORTHERN IOWA.
FROM LATE MORNING AND CONTINUING INTO THE AFTERNOON...DIURNAL
HEATING WILL ALLOW NEW CONVECTION TO BREAK OUT ACROSS THE CWFA.
BASED ON THE PROJECTED LOCATION OF THE VORT MAXES AND NEGATIVE THETA
E LAPSE RATES...AREAS ALONG/EAST OF THE MISSISSIPPI SHOULD HAVE THE
BETTER CHANCES OF SEEING CONVECTION. THUS THE HIGHER POPS WILL BE
ALONG/EAST OF THE MISSISSIPPI FROM LATE MORNING THROUGH THE
AFTERNOON.
CONVECTION THAT DEVELOPS DURING THE AFTERNOON WILL PERSIST INTO THE
EVENING AND SLOWLY DISSIPATE WITH SUNSET. AFTER MIDNIGHT GENERALLY
DRY CONDITIONS SHOULD BE SEEN WITH SUBSIDENCE BEHIND THE DEPARTING
SHORT WAVE AND BUILDING HEIGHTS. ..08..
LONG TERM...SUNDAY THROUGH FRIDAY...
HEAT AND MORE HUMID CONDITIONS WILL RETURN TO THE REGION FOR THE
FIRST HALF OF THE WEEK AS THE WESTERN U.S. UPPER RIDGE EDGES EAST
INTO THE PLAINS. THE DEVELOPING UPPER RIDGE WILL KEEP THE AREA DRY
SUNDAY AND MONDAY. WITH INCREASING SOUTHERLY FLOW AND WAA TEMP
WILL TOP OUT IN THE LOW TO MID 90S SUNDAY AND MAINLY MID 90S FOR
MONDAY. HELD DEW POINTS IN THE MID/UPPER 60S BOTH DAYS WHICH WILL
SUPPORT HEAT INDEX VALUES IN THE 95 TO AROUND 100 RANGE BOTH DAYS.
TUESDAY INTO THURSDAY A DEVELOPING TROF OVER GREAT LAKES AND NEW
ENGLAND WILL SENT A COLD FRONT SOUTH THROUGH THE REGION. THE FRONT
WILL TAKE THE EDGE OFF THE EARLY WEEK HEAT AND IT WILL ALSO
PROVIDE A CHANCE OF RAIN FOR THE REGION. THE FORECAST WAS SKEWED
TOWARD THE ECMWF WHICH BRINGS THE FRONT THROUGH SLOWER THAN THE
OTHER MODELS...ESPECIALLY THE GFS. THE SLOWER MOVEMENT SEEMS
REASONABLE WITH THE FRONT MOVING INTO THE UPPER RIDGE. ALSO MODELS
ARE SHOWING WARM MID LEVELS ALONG AND AHEAD OF THE BOUNDARY
SUGGESTING THE WARM SECTOR WILL BE CAPPED. WITH ALL THE PRECIP
EXPECTED TO BE POST FRONTAL HAVE KEPT TUESDAY DRY AND LIMITED POPS
TUESDAY NIGHT TO THE NORTH HALF. LOW CHANCE POP WERE MAINTAINED
OVER THE ENTIRE AREA WEDNESDAY THEN STARTED TO DRY THE FORECAST OUT
FROM NORTH TO SOUTH WEDNESDAY NIGHT INTO FRIDAY AS THE BOUNDARY PUSHES
FAR ENOUGH SOUTH. WITH THE WARM MID LEVEL TEMPERATURES IN PLACE
AND FORCING ALONG AND NORTH OF THE FRONT REMAINING WEAK ANY
SHRA/TSRA OCCURRING WITH THIS SYSTEM SHOULD BE SCATTERED.
THE FRONT WILL ALSO BRING SOME SLIGHTLY COOLER TEMPERATURES TO THE
AREA FOR MID TO LATE WEEK. HEAT INDEX VALUES AROUND 100 ARE
EXPECTED OVER THE ENTIRE AREA TUESDAY BUT SHOULD BE LIMITED TO THE
SOUTH HALF OF THE AREA WEDNESDAY AND THURSDAY.
DLF
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
815 AM EDT SAT JUL 14 2012
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES ALONG WITH INCREASING
HUMIDITY WILL BRING SHOWERS AND A CHANCE FOR THUNDERSTORMS TO THE
AREA THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE TO INCREASE POPS ACROSS THE SOUTHERN HALF OF THE CWA. LAST
FEW RUNS OF THE HRRR INDICATE SHOWERS SHOULD BECOME MORE NUMEROUS
OVER THE LATE MORNING HOURS.
PREVIOUS DISCUSSION...
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES AN EAST-WEST ORIENTED
RIDGE AXIS ACROSS THE CAROLINAS WITH A TROUGH AXIS EXTENDING FROM
THE UPPER MIDWEST INTO THE MISSOURI VALLEY. THE UPPER OHIO VALLEY
REMAINS IN A SOUTHWESTERLY FLOW BETWEEN THE TWO FEATURES. AT THE
SURFACE, MOISTURE CONTINUES TO BE ON THE INCREASE WITH WARM DEW
POINT ADVECTION. A WEAK BOUNDARY ACROSS WEST VIRGINIA ALONG WITH A
LOBE OF VORT ENERGY ARE PROVIDING FORCING FOR SCATTERED SHOWERS
MOVING NORTHEASTWARD ACROSS THE STATE.
THE TROUGH AXIS ACROSS THE UPPER MIDWEST WILL EDGE SLOWLY EASTWARD
INTO THE WESTERN GREAT LAKES TODAY WITH A MID-LEVEL SOUTHWESTERLY
FLOW CONTINUING ACROSS THE UPPER OHIO VALLEY. THIS WILL ALLOW FOR
DEEP MOISTURE TO ADVECT ACROSS THE AREA TODAY WITH PRECIPITABLE
WATER VALUES INCREASING TO 1.9 TO 2 INCHES BY EARLY AFTERNOON. THERE
IS A CHANCE OF SHOWERS EARLY AS VORT ENERGY FROM OHIO-WV MOVES INTO
WESTERN PA. THIS AFTERNOON, MORE HEATING IS ANTICIPATED ACROSS THE
FORECAST AREA WITH BREAKS IN CLOUD COVERAGE. WITH SURFACE-BASED
INSTABILITY INCREASING TO AROUND 2000 J/KG AND DEEP LAYER MOISTURE
IN PLACE, SHOWERS ARE LIKELY WITH A CHANCE OF THUNDERSTORMS THIS
AFTERNOON. HEAVY DOWNPOURS WILL BE POSSIBLE WITH CONVECTION TODAY,
ALTHOUGH HAVE HELD OFF ON MENTIONING ANY FLASH FLOODING THREAT IN
THE HWO DUE TO 20-30KT STORM MOTION ANTICIPATED TODAY. GENERALLY A
TENTH TO A QUARTER OF AN INCH OF PRECIPITATION IS FORECAST WITH,
ALTHOUGH LOCALLY HEAVIER AMOUNTS WILL OCCUR WITHIN THUNDERSTORMS.
MAV/MET GUIDANCE HAS TRENDED COOLER FOR TEMPS TODAY, WITH HIGHS IN
THE RANGING FROM THE LOWER 80S NORTH OF PITTSBURGH TO THE MID 80S
ACROSS NORTH- CENTRAL WV.
VORT ENERGY WITH RIPPLES IN 500MB SOUTHWESTERLY FLOW WILL CONTINUE
TO MOVE ACROSS THE AREA TONIGHT. CHANCE POPS WILL CONTINUE DESPITE
THE LOSS OF HEATING. WITH CLOUD COVERAGE AND TDS IN THE UPPER 60S,
LOWS ARE A FEW DEGREES WARMER THAN MAV/MET GUIDANCE, NEAR 70
ACROSS MOST OF THE LOWLANDS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
THERE IS GFS/NAM AGREEMENT THAT THE POSITIVELY MID-LEVEL TROUGH
WILL DE-AMPLIFY AS IT CROSSES THE GREAT LAKES WITH THE FLOW
BECOMING MORE ZONAL LOCALLY ON SUNDAY. WITH A SATURATED
ATMOSPHERIC COLUMN REMAINING IN PLACE AND MODERATE INSTABILITY
ONCE AGAIN, THIS WILL ALLOW FOR SCATTERED SHOWERS AND
THUNDERSTORMS WITH LOCALLY HEAVY DOWNPOURS ACROSS THE AREA.
COVERAGE WILL INCREASE DURING THE AFTERNOON AND EARLY EVENING
HOURS ON SUNDAY. AN ADDITIONAL QUARTER TO HALF OF AN INCH OF
PRECIP IS EXPECTED DURING THE DAY SUNDAY.
NAM/ECMWF INDICATE THAT THE MID-LEVEL FLOW WILL SHIFT TO MORE
NORTHWESTERLY ACROSS THE UPPER OHIO VALLEY AS THE TROUGH SHIFTS EAST
OF THE AREA AND RIDGING BUILDS WESTWARD FROM THE CAROLINAS INTO THE
TN VALLEY. DEEP MOISTURE WILL SHIFT EAST OF THE AREA, WITH
1000-800MB MOISTURE LINGERING. THIS MAY BE SUFFICIENT FOR AN
ISOLATED SHOWER OR THUNDERSTORM TO DEVELOP ON MONDAY AFTERNOON.
TEMPS WILL BE NEAR NORMAL SEASONAL VALUES ON SUNDAY. WITH DRIER
AIR ALOFT ADVECTING INTO THE AREA, DECREASED CLOUD COVERAGE ON
MONDAY WIL ALLOW TEMPS TO WARM TO A FEW DEGREES ABOVE NORMAL, INTO
THE MID TO UPPER 80S ACROSS THE LOWLANDS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
EXPECT CONTINUED HUMID CONDITIONS AND WARMER THAN NORMAL
TEMPERATURES ACROSS THE UPPER OHIO VALLEY DURING THE EXTENDED
PERIOD. WENT CLOSE TO HPC NUMBERS WHICH ARE GENERALLY BETWEEN 5 AND
10 DEGREES ABOVE THE NORM.
A COLD FRONT IS PROGGED TO MOVE SLOWLY SOUTHWARD ACROSS THE GREAT
LAKES TUESDAY INTO EARLY WEDNESDAY...AND THROUGH THE FORECAST AREA
WEDNESDAY. BEHIND THE FRONT, GFSE/ECMWF ARE IN AGREEMENT THAT A
DRIER, NORTHWESTERLY FLOW WILL BRING DRY END TO THE WORK WEEK.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
THE LOW CLOUD DECK ACROSS THE AREA SEEMS TO BE RATHER RAGGED AND
DISCONTINUOUS EARLY THIS MORNING. IT WOULD SEEM THAT THIS DECK
SHOULD AT LEAST PERSIST IF NOT BECOME A BIT MORE DENSE IN THE
AREAS OF MID AND HIGH LEVEL CLEARING TRANSITING NORTHWARD ACROSS
THE AREA PER INFRARED IMAGERY. A NORTHEASTWARD MOVING SYSTEM WILL
BRING THICKER CLOUD COVER AND SHOWERS NORTHWARD ACROSS THE AREA
FROM SOUTH TO NORTH STARTING ROUGHLY 08Z FIRST AROUND KMGW. ALL
SITES SHOULD SEE SHOWERS AT TIME THROUGH THE DAY ON SATURDAY.
AREAS THAT SEE SOME BREAKS ARE QUITE LIKELY TO SEE THUNDERSTORMS
DEVELOP...HOWEVER THEIR LOCATION AND TIMING IS FAR TOO UNCERTAIN
TO PLACE INTO THE CODED TAFS AT THIS TIME. MVFR CONDITIONS WILL
REMAIN COMMON THROUGH THE MORNING HOURS THEN AGAIN BECOME COMMON
AFTER SHOWERS END SATURDAY EVENING. FRIES
OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY...
INCREASED SURFACE LAYER HUMIDITY CAN PROMOTE POSSIBLE RESTRICTIONS
DUE TO PATCHY FOG AND HAZE EACH MORNING, AND SHOWERS AND
THUNDERSTORMS AT ANY TIME.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1053 AM EDT SAT JUL 14 2012
.SYNOPSIS...
THOUGH MAINLY DRY TODAY...ISOLATED SHOWERS AND PERHAPS A
THUNDERSTORM ARE AGAIN POSSIBLE THIS AFTERNOON INTO EVENING. A
MOIST SOUTHWEST FLOW WILL BRING MUCH BETTER CHANCES FOR RAIN AND
SCATTERED THUNDERSTORMS LATE TONIGHT INTO SUNDAY...ALONG WITH
HIGHER HUMIDITY LEVELS. AFTER ABOVE NORMAL TEMPERATURES EARLY IN
THE WORKWEEK...OUR NEXT BETTER CHANCE FOR RAIN WILL BE WITH AN
EXPECTED COLD FRONT TUESDAY NIGHT OR WEDNESDAY.
&&
.NEAR TERM /THROUGH SUNDAY/...
1030 AM UPDATE...
SMALL WAVE THAT CAUSED SLOW MOVING SHOWERS/THUNDER IN THE
NORTHEAST ZONES DURING THE PREDAWN HOURS...IS NOW SHIFTING EAST AS
UPPER RIDGING OCCURS TODAY. A WEAK VESTIGE OF THAT WAVE
THOUGH...EXTENDS ACROSS NORTHEAST PA. DIFFERENTIAL HEATING
BOUNDARY...BETWEEN CLOUDS ALONG AND SOUTH OF WYOMING VALLEY...AND
SUNSHINE TO THE NORTH...MAY LEAD TO ATTEMPTED CONVECTIVE
DEVELOPMENT WITH DIURNAL HEATING. HOWEVER...THE STRUGGLE TODAY
COMPARED TO THE LAST COUPLE AFTERNOONS...IS THAT SIGNIFICANT
WARMING ALOFT WILL CAUSE MORE INHIBITION. USING THE PRECIPITABLE
WATER VALUES OF HIGH RESOLUTION MODELS SUCH AS THE HRRR AND
WRFARW...I PLACED A WNW-ESE AXIS OF ONLY SLIGHT CHANCE POPS
INITIALLY ALONG THE DIFFERENTIAL HEATING BOUNDARY AND THEN LIFTING
SLOWLY NORTHWARD ACROSS MOST OF THE AREA THIS AFTERNOON. GOOD
NORTH-TO-SOUTH GRADIENT IN HIGH TEMPERATURES TODAY...FROM LOWER
90S IN LAKE PLAIN WITH MORE SUNSHINE...TO ONLY LOWER 80S IN MUCH
OF NORTHEAST PA WITH MORE CLOUDS AND MOISTURE /EVEN UPPER 70S
HIGHER ELEVS/.
SO MAINLY DRY TODAY...ONLY ISOLATED SHOWERS/THUNDER AT BEST. MAIN
RAIN CHANCES ARE DEFINITELY LATE TONIGHT THROUGH SUNDAY. BECAUSE
OF THE WARMING ALOFT...IT WILL TAKE ADVECTING IN THE SOUPY AIR
MASS OF 1.75-2 INCHES PRECIPITABLE WATER FROM THE SOUTHWEST...FOR
ATMOSPHERIC COLUMN TO OVERCOME INHIBITION. SOUNDINGS BECOME NEARLY
MOIST ADIABATIC...SUGGESTING EFFICIENT RAINERS...YET SOUTHWEST
FLOW ALSO INCREASES WHICH WILL ALLOW CONVECTIVE ACTIVITY TO
ACTUALLY PROGRESS RATHER THAN DRIFTING SLOWLY AS HAS BEEN THE CASE
RECENTLY.
THERE WILL BE LITTLE SURFACE REFLECTION...BUT ALOFT THIS WILL VERY
MUCH RESEMBLE A WARM FRONT-TO-COLD FRONT SITUATION. SOUTHWEST FLOW
WAVE /PSEUDO-WARM FRONT/ IS SET TO PASS 06Z-12Z SUNDAY...FOLLOWED BY
WAVE COMING IN FROM THE WEST-NORTHWEST /PSEUDO-COLD FRONT/ LATE IN
THE DAY TO EARLY EVENING...AIDED BY DIURNAL HEATING AHEAD OF
IT...WHILE ACTUAL SURFACE REFLECTION OF COLD FRONT MAY LINGER TO
OUR NORTHWEST AND NOT EVEN GET INTO OUR AREA. POPS UPDATED TO HIGH
CHANCE OR LIKELY WITH THESE FEATURES...WITH FOCUS ESPECIALLY ON
CENTRAL TO SOUTHEAST ZONES WHERE MOISTURE AVAILABILITY AND TIMING
OF INGREDIENTS WILL COME TOGETHER BEST. LOOKING AT AREAL AVERAGE
QPF TOTAL RANGING FROM ROUGHLY A QUARTER- TO-THIRD OF AN INCH
NORTHWEST...TO MORE LIKE TWO-THIRDS TO THREE- QUARTERS OF AN INCH
SOUTHEAST. GIVEN VERY MOIST SOUNDINGS THOUGH...WE WILL HAVE TO
WATCH FOR MESOSCALE INFLUENCES TO PRODUCE LOCALIZED AREAS IN
EXCESS OF AN INCH. VAST MAJORITY OF THE AREA HAS BEEN VERY DRY
LEADING UP TO THIS EVENT...AND WILL EASILY BE ABLE TO HANDLE THE
RAINFALL. WILL INSTEAD HAVE TO MONITOR FOR URBAN AREAS FOR
RUNOFF/PONDING OF WATER ON ROADS OR OTHER VERY LOCALIZED MINOR
WATER ISSUES.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
THE BERMUDA HIGH WILL SHIFT WESTWARD AND DEVELOP OVER THE
SOUTHERN STATES...WITH FLOW AROUND IT USHERING OUR MOISTURE OFF TO
THE EAST FOR MONDAY. THIS WILL ALLOW FOR A ANOTHER QUIETER WEATHER
DAY FOR MONDAY...WITH JUST A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. HIGHS MONDAY SHOULD BE IN THE MID TO UPPER 80S AND
LOWS IN THE MID TO UPPER 60S SUNDAY NIGHT-MONDAY NIGHT.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
WE STARTED WITH HPC GUIDANCE BUT DID MAKE SOME TWEEKS AT THE START
OF THE MEDIUM RNG PD DUE TO GOOD AGREEMENT BETWEEN THE 12Z GFS
AND 00Z EURO...SUGGESTING A FASTER FROPA THAT CRNTLY INDICATED BY
HPC. MDLS SUGGEST THE FRONT WILL MOVE INTO THE NRN BGM CWA LATE ON
TUE NGT...AND MOV INTO NE PA ON WED AFTN...WITH A CHC FOR
SHRA/TSRA. AFTER FROPA...A LARGE AREA OF HIGH PRES IS FCST TO WORK
EWD INTO THE RGN FROM THE UPPER GT LAKES...SO WE ELIMINATED LOW
CHC/SLGT CHC POPS FOR THE LATTER PART OF THE WEEK (ALTHO AN ISOLD
-SHRA CAN`T BE RULED OUT DUE TO WEAK IMPULSES IN THE NWLY FLOW
ALOFT). MAIN THEME IS A RETURN TO VERY PLEASANT CONDITIONS AFTER
MIDWEEK FROPA.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
UPR WV SLOWLY EXITING THE AREA THIS MRNG. SCT CONV WEAKENING AS
DRIER AIR MVES IN SO NO NEED OF TRW IN THE TAFS. LL MOISTURE HAS
BROUGHT MVFR FOG TO ELM...THIS SHD RAPIDLY MIX OUT LTR THIS MRNG.
ISLTD WEAK CONV WILL NOT BRING ENUF CVRG TO MENTION IN TAFS THIS
AFTN. NEXT WV APRCHS LATE IN THE TAF PD TO INCRS THE MOISTURE IN
THE AREA THIS WILL BRING BACK THE PSBLTY OF MVFR FOG IN ELM...BUT
OVRNGT STABILITY SHD LIMIT CONV. WEAK FLOW WILL BRING LGT WINDS
THRU THE PD.
OUTLOOK...
SUN...SCT MVFR IN SHWRS/TSTMS.
SUN NGT/MON...VFR. ISOLD SHRA/TSRA PSBL.
TUE...VFR.
TUE NGT/WED...SCT MVFR IN SHRA/TSRA.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...MDP
SHORT TERM...MDP/SLI
LONG TERM...
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1016 AM EDT SAT JUL 14 2012
.SYNOPSIS...
WARM AND MOIST AIR FROM THE OHIO VALLEY WILL BUILD INTO THE
REGION THIS WEEKEND...RESULTING IN A CONTINUATION OF ABOVE NORMAL
TEMPERATURES AND AN INCREASING CHANCE FOR SHOWERS AND THUNDERSTORMS.
SLIGHTLY DRIER AIR WILL ENTER EARLY NEXT WEEK...WHILE THE MID-SUMMER
HEAT IS FORECAST TO REMAIN IN PLACE.
&&
.NEAR TERM /THROUGH TONIGHT/...
A BROAD AREA OF HIGH PRESSURE WILL REMAIN ACROSS THE EASTERN
SEABOARD...WHICH WILL MAINTAIN A WARM SOUTHERLY FLOW ACROSS
WESTERN NEW YORK. TODAY SHOULD START OFF WITH A FAIR AMOUNT OF
SUNSHINE ACROSS WESTERN NEW YORK.
AS WAS THE CASE YESTERDAY...DIURNAL INSTABILITY WILL DEVELOP DURING
THE AFTERNOON HOURS. WHILE A WEAK UPPER LEVEL DISTURBANCE MOVED
ACROSS THE REGION YESTERDAY...GUIDANCE SUGGESTS WEAK UPPER RIDGING
THIS AFTERNOON. THE 12Z BUFFALO SOUNDING SHOWS FAIRLY STEEP LAPSE
RATES ABOVE 850 MB...BUT IT IS ALSO QUITE DRY. WHILE THIS PROBABLY
WILL NOT BE ENOUGH TO ENTIRELY SUPPRESS CONVECTION...AREAL COVERAGE
OF SHOWERS SHOULD BE LIMITED...PERHAPS EVEN A BIT LESS THAN
YESTERDAY. THIS STILL JUSTIFIES CHANCE POPS IN THE SAME REGIONS
PRONE TO SHOWERS AND THUNDERSTORMS YESTERDAY...THOUGH CELLS MAY
DEVELOP IN SLIGHTLY DIFFERENT LOCATIONS. EXPECT ISOLATED TO
SCATTERED STORMS TO DEVELOP BY MID AFTERNOON ACROSS THE INTERIOR
SOUTHERN TIER AND GENESEE VALLEY MAINLY SOUTH OF THE THRUWAY. MEAN
QPF FORECASTS FROM THE SREF/NAM/RGEM/GFS ACTUALLY PAINT A PRETTY
GOOD GENERAL PICTURE OF THIS...AND RUNS OF THE HRRR APPEAR TO SPARK
CONVECTION SHORTLY AFTER NOON.
LAKE BREEZES WILL ENHANCE SURFACE CONVERGENCE...WITH THE BEST CHANCE
FOR THUNDERSTORMS SOUTH AND EAST OF BUFFALO ALONG AND EAST OF THE
ERIE LAKE BREEZE. STORMS WILL AGAIN BE SLOW MOVERS...AND WHILE THE
MAJORITY OF THE REGION WILL REMAIN DRY...THUNDERSTORMS WHICH DO
DEVELOP COULD BRING SIGNIFICANT RAINS TO ISOLATED LOCATIONS.
TODAY SHOULD CONTINUE TO BE WARM...WITH HIGHS LIKELY TO CLIMB INTO
THE 80S ACROSS THE REGION...SIMILAR TO PERHAPS A TAD COOLER THAN
YESTERDAY.
THE FORECAST GETS A BIT TRICKIER TONIGHT. MORE MOIST AIR ACROSS THE
OHIO VALLEY WILL BUILD INTO THE REGION TONIGHT. DEW POINTS WILL RISE
INTO THE UPPER 60S TO LOWER 70S...WHICH WILL INCREASE INSTABILITY
EVEN DURING THE NIGHTTIME HOURS. MODEL GUIDANCE IS INCONSISTENT ON
THE DEVELOPMENT OF SHOWERS TONIGHT...WITH SOME MODELS (NAM/RGEM)
FAIRLY BULLISH ON THUNDERSTORMS TONIGHT WHILE OTHERS
(UKMET/EUROPEAN/GFS) TENDING TO SHOW LESS ACTIVITY OR KEEP IT TO THE
SOUTH. WITH NO WELL DEFINED BOUNDARY...EXPECT ANY ACTIVITY TO BE
SCATTERED IN NATURE...AND LIKELY TO COME WITH OR AFTER THE MOIST
AIRMASS BUILDS IN. THERE IS A SLIGHTLY GREATER CHANCE FOR SHOWERS
AND THUNDERSTORMS IN THE SOUTHERN TIER...BUT SEE A CHANCE AT ANY
LOCATION LATE TONIGHT AS THE MOIST AIR MOVES INTO THE BOUNDARY LAYER.
WARMER DEW POINTS SHOULD KEEP TEMPERATURES FROM DROPPING TOO MUCH
TONIGHT...WITH OVERNIGHT LOWS LIKELY TO BE IN THE UPPER 60S AND
LOWER 70S. ALSO EXPECT FOG TO BE A BIT MORE WIDESPREAD...ESPECIALLY
IF SKIES CLEAR OUT AT ALL.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
ON SUNDAY...THE SHORT TERM GUIDANCE IS IN FAIR AGREEMENT THAT AN
INITIAL WEAK SHORTWAVE TROUGH DRAPED FROM THE FINGER LAKES EASTWARD
INTO CENTRAL/EASTERN NEW YORK WILL SLIDE EAST OF THE AREA DURING THE
COURSE OF SUNDAY MORNING...WITH ITS ASSOCIATED SWATH OF DEEPER
MOISTURE/POSSIBLE CONVECTION ALSO GETTING DRAGGED OFF INTO EASTERN
NEW YORK. "POSSIBLE" IS THE KEY WORD HERE WITH RESPECT TO THE
CONVECTIVE POTENTIAL ASSOCIATED WITH THIS INITIAL WAVE...AS THE
VARIOUS GUIDANCE PACKAGES EXHIBIT CONSIDERABLE DISAGREEMENT AS TO
THE EXTENT OF THE AVAILABLE LIFT/MOISTURE AND RESULTANT CONVECTION.
IN ONE CAMP ARE THE NAM AND GFS...WHICH ARE A BIT MORE ROBUST AND
SHOW AT LEAST SOME SCATTERED CONVECTION ACROSS PORTIONS OF THE
FINGER LAKES AND NORTH COUNTRY...WHILE THE ECMWF AND GEM ARE BOTH
NOTABLY WEAKER AND ACTUALLY GENERATE LITTLE IF ANY CONVECTION.
BEHIND THIS INITIAL WAVE...CLOUD COVER WILL LIKELY THIN OUT AT LEAST
ENOUGH TO ALLOW FOR SOME PARTIAL SUNSHINE BY LATE MORNING/EARLY
AFTERNOON AS THE DEEPER MOISTURE SLIDES OFF TO OUR EAST...ALLOWING
FOR DECENT HEATING OF A VERY WARM AND HUMID AIRMASS...AND IN TURN
LEADING TO INCREASING AMOUNTS OF DIURNAL INSTABILITY. AT THE SAME
TIME...THE MAIN AXIS OF THE LARGE-SCALE UPPER TROUGH WILL BE SLIDING
EAST FROM THE CENTRAL GREAT LAKES...AND THIS ALONG WITH POTENTIAL
LAKE BREEZE BOUNDARIES SHOULD HELP TO TRIGGER A ROUND OF MORE
GENERAL SCATTERED CONVECTION DURING THE AFTERNOON.
WITH ALL OF THE ABOVE FACTORS IN MIND...HAVE ELECTED TO CUT BACK ON
SUNDAY`S POPS FROM OUR EXISTING CONTINUITY...LOWERING THESE FROM LOW
LIKELY BACK TO THE CHANCE RANGE. MORE SPECIFICALLY...FOR SUNDAY
MORNING HAVE INDICATED HIGH CHANCE POPS ACROSS OUR EASTERN ZONES IN
ASSOCIATION WITH THE INITIAL DEPARTING WAVE AND ASSOCIATED SLUG OF
DEEPER MOISTURE...WHILE PLACING PROGRESSIVELY LOWER PRECIP CHANCES
FURTHER TO THE WEST. AFTER THAT...HAVE TRANSITIONED TO MORE OF A
BROADBRUSH MID-CHANCE RANGE POP FOR THE AFTERNOON DUE TO THE
APPROACHING UPPER TROUGH AXIS AND INCREASING DAYTIME INSTABILITY.
AS FOR TEMPS...EXPECT VERY WARM AND HUMID CONDITIONS TO CONTINUE...
WITH WIDESPREAD HIGHS IN THE MID-UPPER 80S COUPLED WITH DEWPOINTS
IN THE UPPER 60S.
SUNDAY NIGHT...ANY LINGERING DIURNALLY-DRIVEN CONVECTION SHOULD TEND
TO SLOWLY FADE OUT FROM WEST TO EAST WITH THE LOSS OF DAYTIME
HEATING AND THE DEPARTURE OF THE AFOREMENTIONED TROUGH AXIS...WHICH
WILL GIVE WAY TO BROAD/FLAT SHORTWAVE RIDGING. ACCORDINGLY...HAVE
INDICATED PRECIP CHANCES FALLING BACK THROUGH THE CHANCE RANGE AND
EVENTUALLY TO SLIGHT CHANCE DURING THE OVERNIGHT HOURS...WITH MUCH
OF THE SECOND HALF OF THE NIGHT LIKELY TO BE LARGELY RAIN FREE.
SULTRY CONDITIONS WILL CONTINUE THOUGH...WITH OVERNIGHT LOWS RANGING
FROM THE MID 60S IN THE INTERIOR OF THE SOUTHERN TIER AND NORTH
COUNTRY...TO THE LOWER 70S ACROSS THE LAKE PLAINS.
THEREAFTER...THE REMAINDER OF THE SHORT TERM PERIOD SHOULD LARGELY
FEATURE A CONTINUATION OF UNCOMFORTABLY WARM TO HOT AND HUMID
TEMPERATURES ALONG WITH LARGELY DRY CONDITIONS...AS OUR AREA WILL
REMAIN UNDER THE INFLUENCE OF A BROAD/FLAT UPPER RIDGE OUT AHEAD OF
A COLD FRONT SLOWLY SAGGING SOUTHWARD FROM CENTRAL ONTARIO PROVINCE.
THIS RIDGE SHOULD PROVIDE ENOUGH OF A CAP TO PRECLUDE MUCH MORE THAN
SOME ISOLATED DIURNAL CONVECTION ACROSS THE BULK OF THE AREA BOTH
DAYS...THOUGH SLIGHTLY HIGHER CHANCES FOR CONVECTION COULD REACH THE
SAINT LAWRENCE VALLEY AND NORTH COUNTRY LATER TUESDAY AFTERNOON IF
THE CURRENT GFS/ECMWF TIMING OF THE FRONT DOES INDEED COME TO
FRUITION.
IN TERMS OF TEMPERATURES...850 MB TEMPS OF AROUND +17C MONDAY WILL
CLIMB TO AS HIGH AS +18C/+19C TUESDAY...WHICH SHOULD BE ENOUGH TO
SUPPORT FAIRLY WIDESPREAD HIGHS IN THE UPPER 80S TO LOWER 90S
MONDAY...AND LIKELY EVEN A FEW DEGREES HIGHER THAN THAT ON TUESDAY.
IN BETWEEN WILL BE ANOTHER SULTRY NIGHT MONDAY NIGHT...WHEN LOWS
WILL AGAIN MAINLY RANGE FROM THE MID 60S TO LOWER 70S. THROUGHOUT
THIS TIME...DEWPOINTS WILL REMAIN AT UNCOMFORTABLE LEVELS IN THE MID
TO UPPER 60S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
THE GFS AND ECMWF ARE IN DECENT AGREEMENT IN SHOWING THE COLD FRONT
CROSSING THE FORECAST AREA SOMETIME BETWEEN TUESDAY NIGHT AND
WEDNESDAY...WITH CANADIAN HIGH PRESSURE THEN BUILDING ACROSS THE
GREAT LAKES DURING THE REMAINDER OF THE PERIOD ALONG WITH A RETURN
TO COOLER/DRIER WEATHER. GIVEN SOME CONTINUED DIFFERENCES IN THE
EXACT TIMING OF THE FRONT...WILL CARRY BROADBRUSH SHOWER AND
THUNDERSTORM CHANCES TUESDAY NIGHT AND WEDNESDAY...WITH DRY WEATHER
THEN INDICATED FOR THE REMAINDER OF THE WORK WEEK.
TEMPERATURE-WISE...WILL HAVE VERY WARM AND HUMID CONDITIONS
CONTINUING INTO TUESDAY NIGHT IN ADVANCE OF THE APPROACHING
FRONT...WITH READINGS THEN SETTLING BACK TO AT LEAST MORE SEASONABLE
LEVELS FOR THE BALANCE OF THE WEEK...ALONG WITH MUCH MORE
COMFORTABLE HUMIDITY TO BOOT. IN FACT...IF THE LATEST GFS/ECMWF
DEPICTION OF 850 MB TEMPS OF +8C TO +10C FOR THURSDAY AND FRIDAY
TURNS OUT TO BE CORRECT...TEMPS THEN COULD EVEN BE A BIT COOLER THAN
PRESENTLY INDICATED.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE WILL REMAIN GENERALLY IN CONTROL THROUGH THIS
MORNING...WITH MINIMAL SHOWER ACTIVITY EXPECTED THROUGH THE MORNING
HOURS. AFTER THIS...DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS
SHOULD DEVELOP. LIKE YESTERDAY...THESE SHOULD BE SCATTERED IN
NATURE...TENDING TO FORM ALONG OR INLAND OF LAKE-BREEZE
BOUNDARIES. WHILE ITS HARD TO COMPLETELY RULE OUT A SHOWER OR
THUNDERSTORM AT BUF/IAG/ART...FEEL CHANCES ARE QUITE LOW...WITH A
SLIGHTLY BETTER CHANCE AT ROC. THE BEST CHANCE IS AT JHW...WITH
THUNDERSTORMS LIKELY TO DEVELOP AT OR NEAR THE TAF SITE DURING THE
AFTERNOON HOURS TODAY...THOUGH THE EXACT TIMING REMAINS
PROBLEMATIC.
ADDITIONAL MOISTURE WILL MOVE IN TONIGHT...AND THIS WILL BRING A
CHANCE OF SHOWERS AND THUNDERSTORMS LATE THIS EVENING AND TONIGHT.
WHATEVER ACTIVITY DOES DEVELOP SHOULD MOVE FROM WEST TO EAST ACROSS
THE REGION TONIGHT. FOG IS ALSO A POSSIBILITY...THOUGH IT WILL
DEPEND ON WHERE SHOWERS DEVELOP AND IF SKIES CLEAR FOLLOWING THIS
DEVELOPMENT.
OUTLOOK...
SUNDAY...AREAS OF MVFR IN SCATTERED -SHRA/-TSRA.
MONDAY AND TUESDAY...MAINLY VFR.
WEDNESDAY...AREAS OF MVFR IN SCATTERED -SHRA/-TSRA.
&&
.MARINE...
HIGH PRESSURE OVER PA WILL MOVE TO THE EAST COAST TODAY...WITH A
WEAK TROUGH MOVING IN ON SUNDAY. SCATTERED CONVECTION MAY DEVELOP
WITH TROUGH...PRIMARILY SATURDAY NIGHT AND/OR SUNDAY. WINDS AND
WAVES WILL OTHERWISE REMAIN GENERALLY LIGHT WITH LOCAL LAKE BREEZE
CIRCULATIONS TODAY. A SOUTHWESTERLY FLOW WILL PREVAIL ON SUNDAY BUT
WITH SUB-SMALL CRAFT CONDITIONS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL/HITCHCOCK
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL
MARINE...APFFEL/JJR
AREA FORECAST DISCUSSION
NWS BUFFALO NY
745 AM EDT SAT JUL 14 2012
.SYNOPSIS...
WARM AND MOIST AIR FROM THE OHIO VALLEY WILL BUILD INTO THE
REGION THIS WEEKEND...RESULTING IN A CONTINUATION OF ABOVE NORMAL
TEMPERATURES AND AN INCREASING CHANCE FOR SHOWERS AND THUNDERSTORMS.
SLIGHTLY DRIER AIR WILL ENTER EARLY NEXT WEEK...WHILE THE MID-SUMMER
HEAT IS FORECAST TO REMAIN IN PLACE.
&&
.NEAR TERM /THROUGH TONIGHT/...
A BROAD AREA OF HIGH PRESSURE WILL REMAIN ACROSS THE EASTERN
SEABOARD...WHICH WILL MAINTAIN A WARM SOUTHERLY FLOW ACROSS
WESTERN NEW YORK. TODAY SHOULD START OFF WITH A FAIR AMOUNT OF
SUNSHINE ACROSS WESTERN NEW YORK.
AS WAS THE CASE YESTERDAY...DIURNAL INSTABILITY WILL DEVELOP DURING
THE AFTERNOON HOURS. WHILE A WEAK UPPER LEVEL DISTURBANCE MOVED
ACROSS THE REGION YESTERDAY...GUIDANCE SUGGESTS WEAK UPPER RIDGING
THIS AFTERNOON. THE 12Z BUFFALO SOUNDING SHOWS FAIRLY STEEP LAPSE
RATES ABOVE 850 MB...BUT IT IS ALSO QUITE DRY. WHILE THIS PROBABLY
WILL NOT BE ENOUGH TO ENTIRELY SUPPRESS CONVECTION...AREAL COVERAGE
OF SHOWERS SHOULD BE LIMITED...PERHAPS EVEN A BIT LESS THAN
YESTERDAY. THIS STILL JUSTIFIES CHANCE POPS IN THE SAME REGIONS
PRONE TO SHOWERS AND THUNDERSTORMS YESTERDAY...THOUGH CELLS MAY
DEVELOP IN SLIGHTLY DIFFERENT LOCATIONS. MEAN QPF FORECASTS FROM
THE SREF/NAM/RGEM/GFS ACTUALLY PAINT A PRETTY GOOD GENERAL PICTURE
OF THIS...AND RUNS OF THE HRRR APPEAR TO SPARK CONVECTION SHORTLY
AFTER NOON.
LAKE BREEZES WILL ENHANCE SURFACE CONVERGENCE...WITH THE BEST CHANCE
FOR THUNDERSTORMS SOUTH AND EAST OF BUFFALO ALONG AND EAST OF THE
ERIE LAKE BREEZE. STORMS WILL AGAIN BE SLOW MOVERS...AND WHILE THE
MAJORITY OF THE REGION WILL REMAIN DRY...THUNDERSTORMS WHICH DO
DEVELOP COULD BRING SIGNIFICANT RAINS TO ISOLATED LOCATIONS.
TODAY SHOULD CONTINUE TO BE WARM...WITH HIGHS LIKELY TO CLIMB INTO
THE 80S ACROSS THE REGION...SIMILAR TO PERHAPS A TAD COOLER THAN
YESTERDAY.
THE FORECAST GETS A BIT TRICKIER TONIGHT. MORE MOIST AIR ACROSS THE
OHIO VALLEY WILL BUILD INTO THE REGION TONIGHT. DEW POINTS WILL RISE
INTO THE UPPER 60S TO LOWER 70S...WHICH WILL INCREASE INSTABILITY
EVEN DURING THE NIGHTTIME HOURS. MODEL GUIDANCE IS INCONSISTENT ON
THE DEVELOPMENT OF SHOWERS TONIGHT...WITH SOME MODELS (NAM/RGEM)
FAIRLY BULLISH ON THUNDERSTORMS TONIGHT WHILE OTHERS
(UKMET/EUROPEAN/GFS) TENDING TO SHOW LESS ACTIVITY OR KEEP IT TO THE
SOUTH. WITH NO WELL DEFINED BOUNDARY...EXPECT ANY ACTIVITY TO BE
SCATTERED IN NATURE...AND LIKELY TO COME WITH OR AFTER THE MOIST
AIRMASS BUILDS IN. THERE IS A SLIGHTLY GREATER CHANCE FOR SHOWERS
AND THUNDERSTORMS IN THE SOUTHERN TIER...BUT SEE A CHANCE AT ANY
LOCATION LATE TONIGHT AS THE MOIST AIR MOVES INTO THE BOUNDARY LAYER.
WARMER DEW POINTS SHOULD KEEP TEMPERATURES FROM DROPPING TOO MUCH
TONIGHT...WITH OVERNIGHT LOWS LIKELY TO BE IN THE UPPER 60S AND
LOWER 70S. ALSO EXPECT FOG TO BE A BIT MORE WIDESPREAD...ESPECIALLY
IF SKIES CLEAR OUT AT ALL.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
ON SUNDAY...THE SHORT TERM GUIDANCE IS IN FAIR AGREEMENT THAT AN
INITIAL WEAK SHORTWAVE TROUGH DRAPED FROM THE FINGER LAKES EASTWARD
INTO CENTRAL/EASTERN NEW YORK WILL SLIDE EAST OF THE AREA DURING THE
COURSE OF SUNDAY MORNING...WITH ITS ASSOCIATED SWATH OF DEEPER
MOISTURE/POSSIBLE CONVECTION ALSO GETTING DRAGGED OFF INTO EASTERN
NEW YORK. "POSSIBLE" IS THE KEY WORD HERE WITH RESPECT TO THE
CONVECTIVE POTENTIAL ASSOCIATED WITH THIS INITIAL WAVE...AS THE
VARIOUS GUIDANCE PACKAGES EXHIBIT CONSIDERABLE DISAGREEMENT AS TO
THE EXTENT OF THE AVAILABLE LIFT/MOISTURE AND RESULTANT CONVECTION.
IN ONE CAMP ARE THE NAM AND GFS...WHICH ARE A BIT MORE ROBUST AND
SHOW AT LEAST SOME SCATTERED CONVECTION ACROSS PORTIONS OF THE
FINGER LAKES AND NORTH COUNTRY...WHILE THE ECMWF AND GEM ARE BOTH
NOTABLY WEAKER AND ACTUALLY GENERATE LITTLE IF ANY CONVECTION.
BEHIND THIS INITIAL WAVE...CLOUD COVER WILL LIKELY THIN OUT AT LEAST
ENOUGH TO ALLOW FOR SOME PARTIAL SUNSHINE BY LATE MORNING/EARLY
AFTERNOON AS THE DEEPER MOISTURE SLIDES OFF TO OUR EAST...ALLOWING
FOR DECENT HEATING OF A VERY WARM AND HUMID AIRMASS...AND IN TURN
LEADING TO INCREASING AMOUNTS OF DIURNAL INSTABILITY. AT THE SAME
TIME...THE MAIN AXIS OF THE LARGE-SCALE UPPER TROUGH WILL BE SLIDING
EAST FROM THE CENTRAL GREAT LAKES...AND THIS ALONG WITH POTENTIAL
LAKE BREEZE BOUNDARIES SHOULD HELP TO TRIGGER A ROUND OF MORE
GENERAL SCATTERED CONVECTION DURING THE AFTERNOON.
WITH ALL OF THE ABOVE FACTORS IN MIND...HAVE ELECTED TO CUT BACK ON
SUNDAY`S POPS FROM OUR EXISTING CONTINUITY...LOWERING THESE FROM LOW
LIKELY BACK TO THE CHANCE RANGE. MORE SPECIFICALLY...FOR SUNDAY
MORNING HAVE INDICATED HIGH CHANCE POPS ACROSS OUR EASTERN ZONES IN
ASSOCIATION WITH THE INITIAL DEPARTING WAVE AND ASSOCIATED SLUG OF
DEEPER MOISTURE...WHILE PLACING PROGRESSIVELY LOWER PRECIP CHANCES
FURTHER TO THE WEST. AFTER THAT...HAVE TRANSITIONED TO MORE OF A
BROADBRUSH MID-CHANCE RANGE POP FOR THE AFTERNOON DUE TO THE
APPROACHING UPPER TROUGH AXIS AND INCREASING DAYTIME INSTABILITY.
AS FOR TEMPS...EXPECT VERY WARM AND HUMID CONDITIONS TO CONTINUE...
WITH WIDESPREAD HIGHS IN THE MID-UPPER 80S COUPLED WITH DEWPOINTS
IN THE UPPER 60S.
SUNDAY NIGHT...ANY LINGERING DIURNALLY-DRIVEN CONVECTION SHOULD TEND
TO SLOWLY FADE OUT FROM WEST TO EAST WITH THE LOSS OF DAYTIME
HEATING AND THE DEPARTURE OF THE AFOREMENTIONED TROUGH AXIS...WHICH
WILL GIVE WAY TO BROAD/FLAT SHORTWAVE RIDGING. ACCORDINGLY...HAVE
INDICATED PRECIP CHANCES FALLING BACK THROUGH THE CHANCE RANGE AND
EVENTUALLY TO SLIGHT CHANCE DURING THE OVERNIGHT HOURS...WITH MUCH
OF THE SECOND HALF OF THE NIGHT LIKELY TO BE LARGELY RAIN FREE.
SULTRY CONDITIONS WILL CONTINUE THOUGH...WITH OVERNIGHT LOWS RANGING
FROM THE MID 60S IN THE INTERIOR OF THE SOUTHERN TIER AND NORTH
COUNTRY...TO THE LOWER 70S ACROSS THE LAKE PLAINS.
THEREAFTER...THE REMAINDER OF THE SHORT TERM PERIOD SHOULD LARGELY
FEATURE A CONTINUATION OF UNCOMFORTABLY WARM TO HOT AND HUMID
TEMPERATURES ALONG WITH LARGELY DRY CONDITIONS...AS OUR AREA WILL
REMAIN UNDER THE INFLUENCE OF A BROAD/FLAT UPPER RIDGE OUT AHEAD OF
A COLD FRONT SLOWLY SAGGING SOUTHWARD FROM CENTRAL ONTARIO PROVINCE.
THIS RIDGE SHOULD PROVIDE ENOUGH OF A CAP TO PRECLUDE MUCH MORE THAN
SOME ISOLATED DIURNAL CONVECTION ACROSS THE BULK OF THE AREA BOTH
DAYS...THOUGH SLIGHTLY HIGHER CHANCES FOR CONVECTION COULD REACH THE
SAINT LAWRENCE VALLEY AND NORTH COUNTRY LATER TUESDAY AFTERNOON IF
THE CURRENT GFS/ECMWF TIMING OF THE FRONT DOES INDEED COME TO
FRUITION.
IN TERMS OF TEMPERATURES...850 MB TEMPS OF AROUND +17C MONDAY WILL
CLIMB TO AS HIGH AS +18C/+19C TUESDAY...WHICH SHOULD BE ENOUGH TO
SUPPORT FAIRLY WIDESPREAD HIGHS IN THE UPPER 80S TO LOWER 90S
MONDAY...AND LIKELY EVEN A FEW DEGREES HIGHER THAN THAT ON TUESDAY.
IN BETWEEN WILL BE ANOTHER SULTRY NIGHT MONDAY NIGHT...WHEN LOWS
WILL AGAIN MAINLY RANGE FROM THE MID 60S TO LOWER 70S. THROUGHOUT
THIS TIME...DEWPOINTS WILL REMAIN AT UNCOMFORTABLE LEVELS IN THE MID
TO UPPER 60S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
THE GFS AND ECMWF ARE IN DECENT AGREEMENT IN SHOWING THE COLD FRONT
CROSSING THE FORECAST AREA SOMETIME BETWEEN TUESDAY NIGHT AND
WEDNESDAY...WITH CANADIAN HIGH PRESSURE THEN BUILDING ACROSS THE
GREAT LAKES DURING THE REMAINDER OF THE PERIOD ALONG WITH A RETURN
TO COOLER/DRIER WEATHER. GIVEN SOME CONTINUED DIFFERENCES IN THE
EXACT TIMING OF THE FRONT...WILL CARRY BROADBRUSH SHOWER AND
THUNDERSTORM CHANCES TUESDAY NIGHT AND WEDNESDAY...WITH DRY WEATHER
THEN INDICATED FOR THE REMAINDER OF THE WORK WEEK.
TEMPERATURE-WISE...WILL HAVE VERY WARM AND HUMID CONDITIONS
CONTINUING INTO TUESDAY NIGHT IN ADVANCE OF THE APPROACHING
FRONT...WITH READINGS THEN SETTLING BACK TO AT LEAST MORE SEASONABLE
LEVELS FOR THE BALANCE OF THE WEEK...ALONG WITH MUCH MORE
COMFORTABLE HUMIDITY TO BOOT. IN FACT...IF THE LATEST GFS/ECMWF
DEPICTION OF 850 MB TEMPS OF +8C TO +10C FOR THURSDAY AND FRIDAY
TURNS OUT TO BE CORRECT...TEMPS THEN COULD EVEN BE A BIT COOLER THAN
PRESENTLY INDICATED.
&&
.AVIATION /11Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE WILL REMAIN GENERALLY IN CONTROL THROUGH THIS
MORNING...WITH MINIMAL SHOWER ACTIVITY EXPECTED THROUGH THE MORNING
HOURS. AFTER THIS...DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS
SHOULD DEVELOP. LIKE YESTERDAY...THESE SHOULD BE SCATTERED IN
NATURE...TENDING TO FORM ALONG OR INLAND OF LAKE-BREEZE
BOUNDARIES. WHILE ITS HARD TO COMPLETELY RULE OUT A SHOWER OR
THUNDERSTORM AT BUF/IAG/ART...FEEL CHANCES ARE QUITE LOW...WITH A
SLIGHTLY BETTER CHANCE AT ROC. THE BEST CHANCE IS AT JHW...WITH
THUNDERSTORMS LIKELY TO DEVELOP AT OR NEAR THE TAF SITE DURING THE
AFTERNOON HOURS TODAY...THOUGH THE EXACT TIMING REMAINS
PROBLEMATIC.
ADDITIONAL MOISTURE WILL MOVE IN TONIGHT...AND THIS WILL BRING A
CHANCE OF SHOWERS AND THUNDERSTORMS LATE THIS EVENING AND TONIGHT.
WHATEVER ACTIVITY DOES DEVELOP SHOULD MOVE FROM WEST TO EAST ACROSS
THE REGION TONIGHT. FOG IS ALSO A POSSIBILITY...THOUGH IT WILL
DEPEND ON WHERE SHOWERS DEVELOP AND IF SKIES CLEAR FOLLOWING THIS
DEVELOPMENT.
OUTLOOK...
SUNDAY...AREAS OF MVFR IN SCATTERED -SHRA/-TSRA.
MONDAY AND TUESDAY...MAINLY VFR.
WEDNESDAY...AREAS OF MVFR IN SCATTERED -SHRA/-TSRA.
&&
.MARINE...
HIGH PRESSURE OVER PA WILL MOVE TO THE EAST COAST TODAY...WITH A
WEAK TROUGH MOVING IN ON SUNDAY. SCATTERED CONVECTION MAY DEVELOP
WITH TROUGH...PRIMARILY SATURDAY NIGHT AND/OR SUNDAY. WINDS AND
WAVES WILL OTHERWISE REMAIN GENERALLY LIGHT WITH LOCAL LAKE BREEZE
CIRCULATIONS TODAY. A SOUTHWESTERLY FLOW WILL PREVAIL ON SUNDAY BUT
WITH SUB-SMALL CRAFT CONDITIONS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL
MARINE...APFFEL/JJR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1012 AM CDT SAT JUL 14 2012
.DISCUSSION...ONLY MADE SMALL CHANGES TO THE GOING FORECAST TO
INCREASE CLOUDS...ESPECIALLY IN THE WEST. DID NOT CHANGE HIGHS
MUCH AT THIS POINT...THOUGH THERE IS SOME CONCERN THE INCREASED
CLOUDS COULD IMPACT HIGHS TO SOME DEGREE. WILL WATCH TRENDS AND
ADJUST IF IT APPEARS THE CLOUDS BEGIN TO HOLD BACK TEMPERATURES.
HELD ONTO THE SMALL POPS IN THE NORTH CENTRAL PART OF THE STATE
THIS MORNING SINCE KBIS SHOWS A FEW LIGHT RETURNS MOVING IN THAT
DIRECTION...AND THE LATEST RAP STILL BRINGS SOME LIGHT QPF TO THAT
AREA AS WELL.
&&
.AVIATION...SMOKE WILL AT TIMES BRING MINOR VISIBILITY REDUCTIONS
AT KMOT/KISN THIS MORNING...OTHERWISE VFR CONDITIONS WILL PREVAIL.
KBIS SHOWS A FEW LIGHT ECHOES THIS MORNING IN PARTS WESTERN NORTH
DAKOTA...AND AN ISOLATED LIGHT SHOWER CAN NOT BE TOTALLY RULED OUT
AT EITHER KISN OR KMOT THIS MORNING...BUT CHANCES APPEAR SLIM
ENOUGH TO KEEP OUT OF THE TERMINAL FORECASTS.
THUNDERSTORMS WILL BEGIN TO PUSH FROM WEST TO EAST ACROSS NORTH
DAKOTA TONIGHT. THIS ACTIVITY SHOULD BEGIN TO IMPACT KISN/KDIK
AFTER 04Z...THEN IMPACT KMOT/KBIS AFTER 08Z.
&&
.FIRE WEATHER...WINDS ARE EXPECTED TO INCREASE THIS AFTERNOON
WHICH WILL COMBINE WITH VERY DRY VEGETATION AND RELATIVE HUMIDITY
VALUES IN THE 20 TO 25 PERCENT RANGE TO CREATE CRITICAL FIRE
WEATHER CONDITIONS. CLOUDS HAVE INCREASED A BIT MORE THAN INITIALLY
ANTICIPATED...BUT WITH SOME CLEARING ALREADY DEVELOPING IN THE
SOUTHWEST...THINK THERE IS STILL PLENTY OF TIME FOR TEMPERATURES
TO WARM...AND RELATIVE HUMIDITY VALUES TO DROP.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 10 PM CDT /9 PM MDT/ THIS EVENING FOR
NDZ017-031-032-040-043.
&&
$$
CK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1102 AM EDT SAT JUL 14 2012
.SYNOPSIS...
HIGH PRESSURE WILL BE IN CONTROL THROUGH THE WEEKEND AND WILL REMAIN
INTO NEXT WEEK. TEMPERATURES ARE FORECAST TO REMAIN SLIGHTLY ABOVE
NORMAL WITH HUMID CONDITIONS. A FRONTAL BOUNDARY OVER THE OHIO
VALLEY IS EXPECTED TO DROP SOUTH ACROSS THE REGION BY NEXT FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 AM SAT...UPSLOPE SHOWERS HAVE WEAKENED AND DISSIPATED AS
925 MB TO 850 MB FLOW HAS VEERED SLIGHTLY SRLY AND DIMINISHED ON
KGSP VAD WINDS AND RUC PROFILES. THE REGION IS OFF TO A WARMER START
WITH EARLIER DISSIPATION OF THE LOW CLOUDS AND FOG COMPARED TO
YESTERDAY...AND CLOUD STREETS ON DEVELOPING WEAK CONVECTIVE ROLLS
ARE APPARENT IN VISIBLE SATELLITE IMAGERY. WEAK SHOWER ACTIVITY
SHOULD INCREASE IN COVERAGE INTO THE EARLY AFTERNOON...BUT THERE IS
LITTLE MECHANISM FOR MORE ORGANIZED TSTM DEVELOPMENT AT PRESENT.
THERE ARE ALREADY SOME POCKETS OF 2000+ J/KG SFC BASED CAPE...AND
VALUES WELL OVER 3000 ARE LIKELY THIS AFTERNOON GIVEN THE MOIST
DEWPOINTS AND LIMITED MIX OUT. WILL THUS FEATURE SHOTGUN SOLID CHC
POPS ACROSS THE REGION THIS AFTN...WITH THE HIGHEST CHC IN THE WRN
MTNS NEAR BETTER CONVERGENCE AND DIFFERENTIAL HEATING. LAPSE RATES
ARE ONCE AGAIN QUITE LOW...WHICH SHOULD LIMIT SEVERE TSTM POTENTIAL
IN THIS MOIST AIRMASS. ISOLD LOCALIZED FLOODING REMAINS POSSIBLE
WITH ANY TRAINING OF CELLS. TEMPS HAVE BEEN WARMED A DEGREE TOWARD
06Z MAV GUIDANCE WITH THE UPDATE.
THE ATLANTIC RIDGE WILL BE CENTERED DIRECTLY OVER THE WRN CAROLINAS
BY THIS EVENING. A LIGHT SRLY UPSLOPE FLOW AROUND THE RIDGE WILL
LIKELY YIELD ADDITIONAL NOCTURNAL UPSLOPE SHOWERS FOCUSED ON THE SRN
ESCARPMENT TONIGHT. LOW CLOUDS AND PATCHY FOG ARE LIKELY ONCE AGAIN
IN THE MOIST AIRMASS. ANY HYDRO PROBLEMS WITH ANCHORING UPSLOPE
SHOWERS SHOULD BE VERY ISOLD.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 2 AM SATURDAY...ON SUNDAY...A WEAK MID LEVEL TROF IS EXPECTED
TO RIPPLE WEST...REACHING THE GA COAST BY 0Z MON. OTHERWISE...IT
APPEARS THAT HEIGHTS WILL REMAIN A LITTLE MORE THAN 590DAM DURING
THE AFTERNOON. AT THE SFC...A WEAK LEE TROF MAY FORM ACROSS THE
FOOTHILLS AND PIEDMONT. FORCING ACROSS THE REGION SHOULD REMAIN
MINIMAL...FAVORING AREAS ACROSS THE MTNS AND WITHIN THE LEE TROF TO
SEE THE GREATEST COVERAGE OF DEEP CONVECTION. HOWEVER...FORECAST
SOUNDINGS SHOW A SIGNIFICANT INVERSION AROUND 5 KFT...RESULTING IN
AFTERNOON CIN VALUES OF 10 TO 20 J/KG EAST OF THE MTNS. CAPE VALUES
ARE FORECAST TO RANGE BETWEEN 1000 TO 2000 J/KG. IT APPEARS THAT THE
FOOTHILLS AND PIEDMONT WILL REMAIN CAPPED FOR MUCH OF THE
DAY...POSSIBLY BREAKING THE CAP DURING THE HEAT OF THE AFTERNOON.
HEATING OF THE RIDGES SHOULD RESULT IN TSRA BY EARLY
AFTERNOON...INCREASING THROUGH THE EARLY EVENING. I WILL FORECAST
40S POPS ACROSS THE RIDGES WITH 30 TO 20 POPS EAST. COVERAGE SHOULD
FADE DURING THE LATE EVENING. HIGHS SHOULD RANGE AROUND CLIMO.
ON MONDAY...GFS INDICATES THAT MID LEVEL TROF WILL PIVOT OVER THE
MTNS DURING THE AFTERNOON. HOWEVER...THE NAM AND ECMWF MAINTAIN A
RIDGE OVER THE SOUTHERN APPALACHIAN REGION WITH A WEAK LOW OVER
SOUTHERN GA/AL. I WILL FAVOR A NAM/ECMWF BLEND. FORECAST SOUNDINGS
INDICATE THAT THE INVERSION FROM SUNDAY WILL WEAKEN AND CIN SHOULD
BREAK DOWN A LITTLE EARLIER. LITTLE CHANGE IS EXPECTED NEAR THE
SFC...YIELDING ANOTHER DAY OF MTN INITIATION DURING THE EARLY
AFTERNOON. HOWEVER...WEAKER CAPPING SHOULD ALLOW ADDITIONAL
CONVECTION TO FORM NEAR OUTFLOW BOUNDARIES. THIS PROCESS SHOULD
YIELD CHC POPS EAST WITH 30 TO 40 POPS ACROSS THE MTNS. TEMPS SHOULD
WARM OVER SUNDAY VALUES BY A DEGREE OR TWO.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 230 AM SATURDAY...BROAD RIDGING IS EXPECTED TO REMAIN ACROSS THE
REGION THROUGH THE EXTENDED PERIOD. TUESDAY AND WEDNESDAY...SFC
FEATURES WILL REMAIN VERY SUBTLE. CONVECTION SHOULD FOLLOW A DIURNAL
PATTERN BOTH DAYS. FORECAST SOUNDINGS SUPPORT EARLY AFTERNOON
CONVECTION OVER THE MTNS WITH COVERAGE SPREADING EAST DURING THE MID
AFTERNOON. I WILL FORECAST COVERAGE AROUND 30 PERCENT. TEMPERATURES
SHOULD RANGE SLIGHTLY ABOVE NORMAL ON TUESDAY...AND POSSIBLY
REACHING INTO THE MID 90S ON WEDNESDAY.
THURSDAY AND FRIDAY...A LONGWAVE TROF WILL LIKELY DEEPEN ACROSS THE
EAST COAST. A BACKDOOR COLD FRONT WILL SINK SOUTHWARD...PUSHING INTO
THE REGION THURSDAY NIGHT INTO FRIDAY. COVERAGE OF CONVECTION SHOULD
INCREASE ALONG AND AHEAD OF THE FRONT...WITH 30 TO 40 POPS AT NIGHT
AND INCREASING TO 50 POPS DURING THE AFTERNOON AND EVENING.
TEMPERATURES SHOULD REMAIN SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...CLOUD STREETS AROUND THE CLT AIRFIELD SHOULD LEAD TO
MAINLY MVFR CIGS THROUGH LATE MORNING AND THEN VFR CIGS THROUGH MUCH
OF THE AFTN. CONVECTION MAY GET A SLIGHTLY EARLIER START THAN
YESTERDAY GIVEN THE EARLY BREAKUP OF LOW CLOUDS...BUT MESOSCALE
MODELS HAVE NO CONSENSUS ON TSTM TIMING AT THE TERMINAL. WILL
MAINTAIN CONSISTENCY AND FEATURE TEMPO TSRA 20Z TO 00Z LATE THIS
AFTN/EARLY EVENING. LIGHT S TO SE FLOW WITH MIXING IS
EXPECTED...ALONG WITH A RETURN TO MAINLY MVFR LOW CLOUDS TONIGHT.
ELSEWHERE...MOST LOCATIONS HAVE SCATTERED OR LIFTED TO MVFR...BUT
WITH TEMPO MVFR CIGS STILL POSSIBLE NEAR CONVECTIVE CLOUD ROLLS
DEVELOPING. VCSH COVERAGE SHOULD FILL IN WITH HEATING...BUT THERE
ARE NO EASILY TIMED FEATURES TO PIN DOWN THE TSTM MENTION AT
PRESENT. VCTS AFT 18Z STILL LOOKS BEST. WINDS WILL BE LIGHT ON S TO
SE FLOW AROUND THE ATLANTIC RIDGE...WITH A RETURN TO MVFR THEN IFR
CONDITIONS TONIGHT...WITH LIFR POSSIBLE KAVL TO KHKY.
OUTLOOK...A DIURNAL SHOWER AND THUNDERSTORM PATTERN WILL CONTINUE
INTO THE MIDDLE OF NEXT WEEK. THE BEST CHANCE FOR TSTMS WILL BE OVER
MTNS EACH AFTN/EVENING. PATCHY MORNING LOW CLOUDS AND FOG WILL BE
PSBL EACH DAY AS WELL...ESPECIALLY IN THE MOUNTAINS.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...NED
NEAR TERM...HG
SHORT TERM...NED
LONG TERM...NED
AVIATION...HG
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
620 AM CDT SAT JUL 14 2012
.DISCUSSION... /ISSUED 435 AM CDT SAT JUL 14 2012/
THE UPPER LEVEL SHEAR AXIS THAT HAS BOROUGH UNSETTLED WEATHER TO
THE MIDSOUTH OVER THE PAST SEVERAL DAYS WILL WEAKEN...AS AN UPPER
LEVEL SUBTROPICAL HEIGHT RIDGE BUILDS IN FROM THE SOUTHEAST. THIS
WEAKENING WILL OCCUR THROUGH MONDAY... WITH CHANCES OF SHOWERS AND
THUNDERSTORMS CONTINUING IN THE INTERIM.
THE EARLY TO MIDDLE PORTIONS OF THE UPCOMING WEEK WILL SEE A 590DM
500MB HEIGHT RIDGE OVER THE LOWER MS RIVER VALLEY. THE UPPER RIDGE WILL
SERVE TO SUPPRESS MOST OF NOT ALL NIGHTTIME THUNDERSTORMS. ISOLATED
TO SCATTERED AFTERNOON THUNDERSTORMS WILL REMAIN POSSIBLE...WITH THE
GFS HINTING AT WEAKNESSES IN THE UPPER RIDGE AND 700MB TEMPS ONLY
9C TO 10C. WITH AFTERNOON TEMPS IN THE MID 90S...DEWPOINTS IN THE
LOWER 70S AND WEAK SHEAR...ISOLATED TO SCATTERED PULSE THUNDERSTORMS
WILL BE POSSIBLE DURING THE HEAT OF THE DAY.
FOR THE MID TO LATTER PART OF NEXT WEEK... 00Z GFS AND ECMWF WERE
CONSISTENT IN AMPLIFYING THE UPPER RIDGE OVER THE PLAINS AND ROCKY
MOUNTAINS... WHILE HEIGHT FALLS OVER THE NORTHEAST AND APPALACHIA
RESULT IN WEAK NORTHWEST UPPER LEVEL FLOW OVER THE MIDSOUTH. GIVEN
OUR PROXIMITY TO A SOUTHERN PLAINS UPPER RIDGE CENTER... TEMPS
ACROSS THE MIDSOUTH WILL AVERAGE SEVERAL DEGREES ABOVE NORMAL...
BUT NOT AS HOT AS THE PLAINS WILL LIKELY SEE. WEAK DAYTIME CONVECTIVE
INHIBITION DURING THE LATE WEEK PERIODS WILL LIKELY RESULT IN
CONTINUED CHANCES OF MAINLY AFTERNOON THUNDERSTORMS.
PWB
&&
.AVIATION...
12Z TAF SET
LIGHT RAIN CONTINUES TO DEVELOP MAINLY WEST OF THE MISSISSIPPI
RIVER. THE LATEST HRRR MODEL SHOWS THIS CONTINUING THROUGH 18Z.
KMEM WILL LIKELY BE ON THE EDGE. VSBYS COULD BE REDUCED AT KJBR
AND KMEM FROM ANY HEAVIER SHOWERS THAT OCCUR. AFTER 16Z...THE HRRR
WHICH SEEMS TO HAVE BEST HANDLE OF WHAT IS CURRENTLY GOING
ON...INDICATES A LINE OF TSRA DEVELOPING NEAR KMKL SOUTHWARD. HAVE
INTRODUCED A TEMPO GROUP AT KMKL BETWEEN 18Z AND 21Z. NOT AS
CONFIDENT ON ANY OTHER POTENTIAL TSRA DEVELOPMENT TODAY THUS WILL
LEAVE VCTS WORDING AT KMEM FROM 18Z-01Z AND AT KTUP FROM 16Z-01Z.
KJBR WILL LIKELY BE WORKED OVER FROM THIS MORNINGS RAIN THUS
CHANCES OF ANY TSRAS THIS AFTERNOON SEEMS LOW THUS HAVE REMOVED
VCTS WORDING. LIGHT WINDS GENERALLY EXPECTED OVER NEXT 24 HOURS.
KRM
&&
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 89 74 91 75 / 60 30 50 20
MKL 88 71 91 71 / 60 30 50 20
JBR 88 71 91 72 / 60 40 50 20
TUP 88 73 92 73 / 70 40 40 20
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1042 AM CDT SAT JUL 14 2012
.DISCUSSION...
LOW PRESSURE CAN BE SEEN SPINNING AWAY JUST SOUTH OF SHREVEPORT ON
SATELLITE AND RADAR. WATER VAPOR HIGHLIGHTING THE DIFFERENCE IN
AIRMASS ACROSS THE AREA WITH THE VERY MOIST AIRMASS SOUTH FROM A TXK-
UTS-VCT LINE. 12Z LCH SOUNDING THIS MORNING SHOWING NEARLY 2" PW
AND WITH NO CAP AND CAPE INCREASING TO 2000+ WITH HEATING/K-INDEX
34 OR BETTER EXPECT SCATTERED SHOWERS AND THUNDERSTORMS THIS
MORNING ESPECIALLY ALONG THE COAST AND EASTERN AREAS. AFTERNOON
HEATING SHOULD HELP TO BRING OUT THE SEABREEZE AND HAVE SOME
CONCERNS THAT THE SOUTHWESTERN AREAS WILL HAVE LOCALLY HEAVY
RAINFALL THREAT. HIGHER CAPE AND MODELS INDICATING THE STORM
MOTIONS TO SLOW AND THEN REVERSE. HAVE ADDED LOCALLY HEAVY RAIN
POSSIBLE IN THESE AREAS. DRIER AIR ALOFT MAY HELP TO KEEP THEM
FORWARD MOVING. WESTERN HALF OF THE AREA SHOULD MORE EASILY REACH
THE 89-92 DEGREE RANGE AWAY FROM THE THICKER CLOUD COVER AND
MORNING PRECIP...COOLER SOUTH AND EAST.
IMPROVING CONDITIONS ON MOST OF THE AREA RIVER ISSUES OBVIOUSLY
CONTINUING MOST OF THE RIVERS/CREEKS THAT HAVE BEEN HARDEST HIT
THE LAST COUPLE OF DAYS HAVE CRESTED AND BEGUN SLOW FALLS BUT
DOWNSTREAM LOCATIONS SUCH AS SPRING CREEK AT SPRING AT CREST OR
JUST MAKING THE DOWNWARD TURN. LUCE BAYOU STILL CLIMBING.
SUNDAY...EARLY 12Z GUIDANCE STILL FAVORING SETX WITH MORE
SIGNIFICANT RAINFALL AND MAY HAVE TO HOIST THE FLOOD WATCH AGAIN
FOR SUNDAY. WILL WAIT TO GET A LOOK AT THE REMAINDER OF THE 12Z
GUIDANCE BEFORE DOING SO.
45
&&
.PREV DISCUSSION... /ISSUED 644 AM CDT SAT JUL 14 2012/
AVIATION...
UPPER LEVEL LOW PRESSURE LOCATED TO THE EAST OF HGX TAF SITES.
THIS SYSTEM WILL CONTINUE TO CREATE UNSTABLE ATMOSPHERE ALONG WITH
ABUNDANT MOISTURE WILL KEEP CHANCES OF RAINSHOWERS AND SOME
THUNDERSTORMS IN THE AREA TODAY. SOME AREAS OF MVFR CIGS WILL
PERSIST THIS AM BECOMING VFR CONDITIONS EXCEPT IN AND NEAR PCPN
AREAS. WINDS WILL BE GENERALLY LIGHT MOSTLY FROM THE SOUTH TODAY.
AFTER 00Z CONDITIONS WILL IMPROVE WITH MOSTLY VFR CONDITIONS
EXISTING TIL AFTER 06Z WHEN SOME AREAS OF MVFR CIGS WILL RETURN,
PCPN MIGHT INCREASE IN COVERAGE ON SUNDAY AS UPPER LOW TRACKS BACK
TO THE WEST.
PREV DISCUSSION... /ISSUED 413 AM CDT SAT JUL 14 2012/
DISCUSSION...
RADAR IS FAIRLY QUIET THIS MORNING BUT AM EXPECTING SHRA/TSRA TO
INCREASE IN COVERAGE TOWARD DAYBREAK. AT 850 MB...A WEAK AREA OF
LOW PRESSURE WAS NOTED OVER EAST CENTRAL LOUISIANA AND THIS
POSITION IS MUCH FURTHER EAST THAN THE PAST FEW MORNINGS. A WEAK
TROUGH AXIS EXTENDS SOUTH INTO THE NORTHERN GULF OF MEXICO. 850 MB
DEW PTS HAVE DROPPED TO 12-14C BUT PW VALUES REMAIN FAIRLY HIGH
BETWEEN 1.9 AND 2.0 INCHES. AT 250 MB...AN UPPER LEVEL RIDGE WAS
LOCATED OVER THE FOUR CORNERS WITH A SECOND RIDGE OVER GEORGIA.
BETWEEN THE TWO RIDGES IS CYCLONIC SHEAR AXIS THAT EXTENDS FROM
SOUTHERN ILLINOIS TO TEXARKANA TO CORPUS CHRISTI. SOUTHEAST TEXAS
WILL LIE TO THE EAST OF THIS FEATURE TODAY SO AM EXPECTING
SCATTERED SHRA/TSRA. MOISTURE LEVELS ARE STILL RATHER HIGH AND
STORM MOTION IS SLOW SO ANY STORMS THAT DEVELOP WILL HAVE THE
POTENTIAL TO PRODUCE LOCALLY HEAVY RAIN. THAT SAID...FEEL THE
THE HEAVY RAIN THREAT IS LESS THAN THE PAST FEW DAYS AND ATTM DO
NOT FEEL A FLOOD WATCH IS WARRANTED. THE RAP MODEL IS AGGRESSIVE
WITH RAIN CHANCES THIS MORNING WHILE OTHER SHORT TERM MODELS ARE
MORE BENIGN.
THE UPPER LEVEL SHEAR AXIS WILL SLOWLY SHIFT WEST ON SUNDAY. THE
NAM AND ECMWF CONTINUE TO DEVELOP A WEAK 500 MB LOW OR INVERTED
TROUGH. THIS WILL KEEP SOUTHEAST TEXAS IN A FAVORABLE POSITION
FOR ADDITIONAL PCPN. WILL LEAN TOWARD A NAM/ECMWF BLEND FOR
SUNDAY. MON-WED LOOK TO BE FAIRLY TYPICAL FOR SOUTHEAST TEXAS WITH
MAX TEMPS IN THE LOW TO MID 90S AND SHRA/TSRA DEVELOPING ALONG THE
SEA BREEZE. WILL CONTINUE TO 20/30 POPS FOR THE PERIOD. UPPER
LEVEL RIDGING WILL TRY TO BUILD BACK INTO SOUTHEAST TEXAS LATER
NEXT WEEK SO WILL TREND THE SECOND HALF OF NEXT WEEK WARMER AND
DRIER. 43
AVIATION...
CENTRAL AND NORTHERN TAF SITES WILL HAVE MOSTLY MVFR CIGS THIS AM
WHILE VFR CONDITIONS WILL PREVAIL CLOSER TO THE COAST. IFR CIGS IS
ALSO POSSIBLE ESPECIALLY AT KCXO WITH SOME MVFR VSBY POSSIBLE.
EXPECT CONDITIONS TO BECOME MOSTLY VFR AFTER 16Z. RAINSHOWERS AND
SOME WIDELY SCATTERED THUNDERSTORMS WILL BEGIN TO DEVELOP AFTER 14Z
AND INCREASE IN COVERAGE AFTER 18Z WITH MVFR CIGS AND VSBY POSSIBLE
IN AND NEAR PCPN ALONG WITH SOME GUSTY WINDS. EXPECT PCPN TO
DIMINISH AROUND 00Z WITH MVFR CIGS RETURNING TO MOST TAF SITES AFTER
06Z. 34
MARINE...
NO SIGNIFICANT CHANGES TO CURRENT FCST TRENDS. A WEAK SURFACE TROUGH
WILL KEEP LIGHT WINDS IN PLACE THROUGH THE WEEKEND. THE LINGERING
UPPER LEVEL TROF WILL ALSO KEEP SCATTERED STORMS IN THE FCST THROUGH
THE WEEKEND. BRIEF GUSTY WINDS/ELEVATED SEAS ARE POSSIBLE IN AND
NEAR THE STRONGER STORMS. 34
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 91 73 90 73 92 / 40 20 50 20 30
HOUSTON (IAH) 88 74 89 74 91 / 50 20 50 20 30
GALVESTON (GLS) 88 80 88 82 90 / 50 30 50 30 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...45
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
644 AM CDT SAT JUL 14 2012
.AVIATION...
UPPER LEVEL LOW PRESSURE LOCATED TO THE EAST OF HGX TAF SITES.
THIS SYSTEM WILL CONTINUE TO CREATE UNSTABLE ATMOSPHERE ALONG WITH
ABUNDANT MOISTURE WILL KEEP CHANCES OF RAINSHOWERS AND SOME
THUNDERSTORMS IN THE AREA TODAY. SOME AREAS OF MVFR CIGS WILL
PERSIST THIS AM BECOMING VFR CONDITIONS EXCEPT IN AND NEAR PCPN
AREAS. WINDS WILL BE GENERALLY LIGHT MOSTLY FROM THE SOUTH TODAY.
AFTER 00Z CONDITIONS WILL IMPROVE WITH MOSTLY VFR CONDITIONS
EXISTING TIL AFTER 06Z WHEN SOME AREAS OF MVFR CIGS WILL RETURN,
PCPN MIGHT INCREASE IN COVERAGE ON SUNDAY AS UPPER LOW TRACKS BACK
TO THE WEST.
&&
.PREV DISCUSSION... /ISSUED 413 AM CDT SAT JUL 14 2012/
DISCUSSION...
RADAR IS FAIRLY QUIET THIS MORNING BUT AM EXPECTING SHRA/TSRA TO
INCREASE IN COVERAGE TOWARD DAYBREAK. AT 850 MB...A WEAK AREA OF
LOW PRESSURE WAS NOTED OVER EAST CENTRAL LOUISIANA AND THIS
POSITION IS MUCH FURTHER EAST THAN THE PAST FEW MORNINGS. A WEAK
TROUGH AXIS EXTENDS SOUTH INTO THE NORTHERN GULF OF MEXICO. 850 MB
DEW PTS HAVE DROPPED TO 12-14C BUT PW VALUES REMAIN FAIRLY HIGH
BETWEEN 1.9 AND 2.0 INCHES. AT 250 MB...AN UPPER LEVEL RIDGE WAS
LOCATED OVER THE FOUR CORNERS WITH A SECOND RIDGE OVER GEORGIA.
BETWEEN THE TWO RIDGES IS CYCLONIC SHEAR AXIS THAT EXTENDS FROM
SOUTHERN ILLINOIS TO TEXARKANA TO CORPUS CHRISTI. SOUTHEAST TEXAS
WILL LIE TO THE EAST OF THIS FEATURE TODAY SO AM EXPECTING
SCATTERED SHRA/TSRA. MOISTURE LEVELS ARE STILL RATHER HIGH AND
STORM MOTION IS SLOW SO ANY STORMS THAT DEVELOP WILL HAVE THE
POTENTIAL TO PRODUCE LOCALLY HEAVY RAIN. THAT SAID...FEEL THE
THE HEAVY RAIN THREAT IS LESS THAN THE PAST FEW DAYS AND ATTM DO
NOT FEEL A FLOOD WATCH IS WARRANTED. THE RAP MODEL IS AGGRESSIVE
WITH RAIN CHANCES THIS MORNING WHILE OTHER SHORT TERM MODELS ARE
MORE BENIGN.
THE UPPER LEVEL SHEAR AXIS WILL SLOWLY SHIFT WEST ON SUNDAY. THE
NAM AND ECMWF CONTINUE TO DEVELOP A WEAK 500 MB LOW OR INVERTED
TROUGH. THIS WILL KEEP SOUTHEAST TEXAS IN A FAVORABLE POSITION
FOR ADDITIONAL PCPN. WILL LEAN TOWARD A NAM/ECMWF BLEND FOR
SUNDAY. MON-WED LOOK TO BE FAIRLY TYPICAL FOR SOUTHEAST TEXAS WITH
MAX TEMPS IN THE LOW TO MID 90S AND SHRA/TSRA DEVELOPING ALONG THE
SEA BREEZE. WILL CONTINUE TO 20/30 POPS FOR THE PERIOD. UPPER
LEVEL RIDGING WILL TRY TO BUILD BACK INTO SOUTHEAST TEXAS LATER
NEXT WEEK SO WILL TREND THE SECOND HALF OF NEXT WEEK WARMER AND
DRIER. 43
AVIATION...
CENTRAL AND NORTHERN TAF SITES WILL HAVE MOSTLY MVFR CIGS THIS AM
WHILE VFR CONDITIONS WILL PREVAIL CLOSER TO THE COAST. IFR CIGS IS
ALSO POSSIBLE ESPECIALLY AT KCXO WITH SOME MVFR VSBY POSSIBLE.
EXPECT CONDITIONS TO BECOME MOSTLY VFR AFTER 16Z. RAINSHOWERS AND
SOME WIDELY SCATTERED THUNDERSTORMS WILL BEGIN TO DEVELOP AFTER 14Z
AND INCREASE IN COVERAGE AFTER 18Z WITH MVFR CIGS AND VSBY POSSIBLE
IN AND NEAR PCPN ALONG WITH SOME GUSTY WINDS. EXPECT PCPN TO
DIMINISH AROUND 00Z WITH MVFR CIGS RETURNING TO MOST TAF SITES AFTER
06Z. 34
MARINE...
NO SIGNIFICANT CHANGES TO CURRENT FCST TRENDS. A WEAK SURFACE TROUGH
WILL KEEP LIGHT WINDS IN PLACE THROUGH THE WEEKEND. THE LINGERING
UPPER LEVEL TROF WILL ALSO KEEP SCATTERED STORMS IN THE FCST THROUGH
THE WEEKEND. BRIEF GUSTY WINDS/ELEVATED SEAS ARE POSSIBLE IN AND
NEAR THE STRONGER STORMS. 34
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 91 73 90 73 92 / 40 20 50 20 30
HOUSTON (IAH) 90 74 89 74 91 / 50 20 50 20 30
GALVESTON (GLS) 88 80 88 82 90 / 50 30 50 30 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...43
AVIATION/MARINE...34
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1202 PM EDT SAT JUL 14 2012
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH THROUGH THE REGION TODAY. AN UPPER
TROUGH WILL PROGRESS THROUGH THE NORTHERN MID-ATLANTIC REGION
SUNDAY. HIGH PRESSURE ANCHORED OVER THE WESTERN ATLANTIC WILL LEAD
TO HOT AND HUMID CONDITIONS THROUGH THE MIDDLE OF NEXT WEEK. A
COLD FRONT MAY PASS THROUGH THE AREA LATE IN THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
FLASH FLOOD WATCH HAS BEEN ISSUED FOR THE CENTRAL FOOTHILLS...
SHENANDOAH VLY AND POTOMAC HIGHLANDS THRU MIDNIGHT. LAST FEW RUNS
OF THE HRRR AND LOCAL WRF ARW4N/NMM4N CONTINUE TO DEPICT
CONVECTION FIRING ACROSS THIS AREA THIS AFTN... WHERE BREAKS IN
CLOUD COVER WILL LEAD TO HIGHER INSTABILITY. STORMS LIKELY FOCUS
ALONG THE WARM FRONT/DIFFERENTIAL HEATING BOUNDARY. SETUP SUPPORTS
POTENTIAL TRAINING OF STORMS AS STORM MOTION WILL BE ALMOST PARALLEL
TO THE BOUNDARY. MAY NEED TO EXPAND WATCH EWD INTO THE CITIES...
BUT COVERAGE OF STORMS AND FLASH FLOOD THREAT APPEARS TO BE LOWER
ATTM.
PREVIOUS DISCUSSION...
14Z SFC ANALYSIS REVEALS A DIFFUSE WARM FRONT OVER CENTRAL VA AND
SRN MD. THIS BOUNDARY IS MARKED BY LGT NELY WINDS AND DEWPOINTS IN
THE MID 60S TO THE NORTH...WITH SLY FLOW AND DEWPOINTS IN THE LOW
TO MID 70S IN THE WARM SECTOR. DEWPOINTS WILL CONTINUE TO INCREASE
THRUOUT THE DAY AS THE WARM FRONT MOVES NWD AND HIGHER DEWPOINTS
MIX DOWN TO THE SFC.
H8 THETA-E RIDGE AXIS HAS PROGRESSED INTO THE AREA THIS MRNG.
ISENTROPIC LIFT NEAR THE NOSE OF THE RIDGE THAT PRODUCED THE ERY
MRNG ROUND OF SHOWERS HAS ADVANCED NORTH AND EAST OF THE CWA...
WHICH WILL LEAD TO A TEMPORARY LULL IN PRECIP DURING THE LATE
MRNG AND MIDDAY. POP GRIDS HAVE BEEN UPDATED ACCORDINGLY.
EARLIER THIS MRNG...AN ISO TSTM ACROSS THE NRN SUBURBS OF DC
PRODUCED AN IMPRESSIVE 1-2 INCHES OF PRECIP IN UNDER AN HR.
THE ENVIRONMENT IS SUPPORTIVE OF EFFICIENT RAINFALL PRODUCERS/HI-
PRECIP RATES AS EVIDENT IN THE 12Z IAD RAOB SOUNDING...WHICH
SHOWS SATURATION THRU MOST OF THE TROPOSPHERE...PWATS OVER 2
INCHES AND A DEEP WARM CLOUD LAYER. THERE IS A CONCERN FOR AT
LEAST LOCALIZED FLASH FLOODING THIS AFTN...WHEN WE LIKELY SEE AN
UPTICK IN CONVECTION FOLLOWING A SEVERAL HRS OF DAYTIME
DESTABILIZATION. WHILE THE THERMODYNAMIC/MOISTURE PARAMETERS
CLEARLY SUPPORT ISSUANCE OF A FF WATCH...THERE IS STILL
UNCERTAINTY WITH THE DEGREE OF COVERAGE AND LOCATION OF CONVECTION
THIS AFTN AND EVE AS FORCING NEAR THE WARM FRONT BECOMES DIFFUSE.
ALSO...FFG GUIDANCE IS HIGH IN THE CWA...EXCEPT FOR LOCALLY LOWER
AMOUNTS IN AREAS THAT RECEIVED HVY RAIN FROM TSTMS OVER THE PAST
COUPLE OF DAYS. WILL CONTINUE TO MONITOR OBS /HI-RES MODEL
TRENDS...AND MAY ISSUE A FF WATCH ONCE LOCATION AND TSTM COVERAGE
IN THREAT AREA BECOMES CLEARER.
TRENDED COOLER WITH MAX TEMPS TDA FOR LOCATIONS NEAR THE MASON
DIXON LINE...WHERE CLOUD COVER WILL LIMIT DAYTIME HEATING...AND
WARMER ACROSS CENTRAL VA AND SRN MD.
WMFNT WL MAKE ITS WAY N OF CWFA TNGT...SPCLY AFTER MIDNGT...LEAVING
BEHIND JUST A MUGGY AMS. WL ATTEMPT TO SNEAK IN A DRY PD OVNGT DUE
TO DIURNAL MIN AND H8-5 RDG PARKED JUST S OF CWFA...THO RECOGNIZE
THAT LINGERING BNDRYS AND ELEV INSTBY MAY BE ALL IT TAKES TO
TRIGGER A STRAY STORM. NRN/WRN CNTYS MOST LIABLE. STUCK WARM ON
MIN-T DUE TO CLDS/HUMIDITY.
&&
.SHORT TERM /SUNDAY/...
AFTER ABOUT A WEEK OF NEAR-AVERAGE TEMPS AND LOWER HUMIDITY THAN
WE`VE HAD IN RECENT MEMORY...THE HOT/HUMID CONDITIONS WILL RETURN.
CURRENT MODEL TRENDS KEEP THE MAX TEMPS/MAX AFTN HUMIDITY LEVELS
JUST A TOUCH BELOW THE POST-DERECHO WEEK. HOWEVER...THE CAUTIONARY
NOTE IS THAT FORECAST TEMPS 4-5 DAYS OUT COULD EASILY RAISE A COUPLE
OF DEGREES BETWEEN NOW-THEN AFTN DEWPOINTS IN THE U60S/L70S WILL BE
HAZARDOUS REGARDLESS OF THE EXACT TEMP - SO THESE MID-WEEK DAYS
SHOULD BE TAKEN W/ JUST AS MUCH CAUTION AS A COUPLE OF WEEKS AGO.
THE FIRST COUPLE OF DAYS THIS UPCOMING WEEK /SUN-MON/ WILL BE MARKED
BY THE SLOW-STEADY PASSAGE OF A COLD FRONT THE WILL GRADUALLY SETTLE
DOWN ACROSS THE CAROLINAS...LIKE THE LAST COUPLE OF FRONTAL
BOUNDARIES WE`VE HAD MORE THROUGH THE AREA. SUN WILL BE ESPECIALLY
ACTIVE AS THE BOUNDARY DRIFTS ACROSS THE CWA FROM N-S. THE FRONT
WILL UTILIZE MODEST INSTABILITY AND WEAK LOW LEVEL CONVERGENCE AS IT
DRIFTS ACROSS THE REGION. SVR WX FROM THE MID MS VLY TO THE MID ATLC
COAST WILL BE POSSIBLE. A 50-70KT UPPER JET WILL BE CENTERED OVER
THE NY/PA BORDER SUN AND INTO EARLY MON...AIDING CONVECTION DOWN
ACROSS OUR REGION.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
MONDAY...THE FRONTAL BOUNDARY WILL STILL BE SLIDING SWD BUT CLOSE
ENOUGH FOR A LOW POTENTIAL TO DEVELOP AFTN CONVECTION MAINLY TO THE
SOUTH OF THE METRO AREAS BUT A MUCH LOWER CHANCE THAN SUN. ANOTHER
COMPACT LOW PRESSURE SYSTEM WILL BE SLIDING DOWN ACROSS THE GREAT
LAKES MON-TUE. BY WED...A LARGE UPPER TROUGH WELL TO OUR NORTH WILL
HELP PUSH THIS SYSTEM AND IT`S FRONTAL BOUNDARY DOWN ACROSS THE MID
ATLC. THIS APPEARS TO BE A NEWER TREND IN MED RANGE GUIDANCE...BUT A
GOOD ENOUGH CONSENSUS TO RAISE POPS ACROSS THE AREA INTO A HIGHER
CHANCE RANGE. THE POTENTIAL BENEFIT AFTER SUCH AN OCCURRENCE ON WED
/THOUGH ANOTHER ROUND OF SVR WX COULD OCCUR/ WOULD BE A SHARPER
DECREASE IN TEMPS TO CLOSE-OUT THE WEEK IF THE UPPER WAVE PUSHES
ENOUGH COOLER/DRIER NRN AIR TO STIFLE THE HIGHER TEMPS - AND GET US
CLOSER TO AVERAGE LEVELS. WILL MONITOR THIS TREND.
&&
.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
WMFNT NEAR CHO. LOW CLOUDS HAVE HELD ON NORTH OF THE FRONT...WHERE
MVFR CIGS ARE IMPACTING IAD/MRB. BKN TO OVC CIGS WILL PERSIST THRU
MOST OF THE DAY...EXCEPT CIGS MAY SCT BY MIDDAY AT CHO AFTER THE
WARM FRONT PUSHES NORTH OF THE TERMINAL.
SHRA SHUD BECOME MORE NMRS AREAWIDE THIS AFTN AND CONT INTO ELY
EVNG...ANY OF WHICH WL PRODUCE LOCAL VSBY RESTRICTIONS. TOUGH TO
PINPOINT SPECIFICALLY WHEN/WHERE. IFR VSBY PSBL W/IN ANY
SHRA/TSRA AS THESE WILL PRODUCE VERY HVY DOWNPOURS. DIDNT WANT A
LONG PD OF RESTRICTIONS THAT LOW IN THE TAFS...SO COVERED BY VCTS
FOR NOW.
FAIRLY WIDESPREAD SHOWERS/TSTMS POSSIBLE ON SUN AFTN/EVE AS ANOTHER
COLD FRONT SLOWLY SINKS SWD ACROSS THE REGION...EVENTUALLY STALLING
OUT OVER THE CAROLINAS MON-WED. ANOTHER COLD FRONT WILL APPROACH THE
AREA FROM THE GREAT LAKES MID WEEK...PUSHING ACROSS THE REGION ON
WED. GIVEN THIS SOLN...A QUIET END TO THE COMING WEEK WILL BE
EXPECTED W/ HIGH PRESSURE THEN BUILDING IN FROM THE NORTH.
&&
.MARINE...
AS OF 10 AM...WARM FRONT NOW NEAR THE MID TIDAL POTOMAC RVR AND
SRN MD PORTION OF THE CHSPK BAY. SLY FLOW WL BACK OUT OF THE
NORTHEAST IMMEDIATELY PRECEDING THE FRONT...FOLLOWED BY SLY FLOW
ONCE IN WARM SECTOR.
MAY HV SLY CHANNELING TNGT...OTRW FLOW SHUD BE NO MORE THAN 10 KT.
SHRA WL BECOME MORE NRMS TDA...W/ TSRA ALSO PSBL THIS AFTN AND EVE.
OF COURSE WINDS/WAVES WL BE LOCALLY HIER IN/NEAR TSTMS...OTRW
LIGHTNING AND TEMPORARY LOW VSBYS IN HVY DOWNPOURS MAY BE BIGGEST
THREAT. HV KEPT WNDS BLO SCA CRIT...EVEN TNGT ON THE BAY.
A COUPLE OF SLOW-MOVING AND RELATIVELY WEAK FRONTAL BOUNDARIES WILL
MOVE ACROSS THE REGION OVER THE COMING WEEK. THE FIRST WILL SLIDE
DOWN FROM THE NORTH ON SUN EVE...THE OTHER TOWARD THE MIDDLE OF THE
WEEK. EACH PASSAGE WILL CARRY RELATIVELY LIGHT SFC WINDS BUT THERE
WILL BE THE POTENTIAL FOR TSTMS THAT WILL CARRY THEIR OWN CONCERNS
FOR HEAVY RAIN/GUSTY WINDS/LIGHTNING. HIGH PRESSURE IS EXPECTED TO
GRADUALLY MOVE IN TO CLOSE OUT THE WEEK...BEHIND THE MID WEEK COLD
FRONT.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR VAZ025>031-036>040-
503-504.
WV...FLASH FLOOD WATCH THROUGH THIS EVENING FOR WVZ050-055-501>506.
MARINE...NONE.
&&
$$
UPDATE...KLEIN
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
707 AM EDT SAT JUL 14 2012
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH THROUGH THE REGION THIS MORNING
BEFORE DISSIPATING. HIGH PRESSURE OFFSHORE WILL BUILD INTO THE
REGION LATER THIS WEEKEND BRINGING A RETURN OF MUCH WARMER
WEATHER BY EARLY NEXT WEEK. A COLD FRONT WILL TRY TO MAKE ITS WAY
INTO AND THROUGH THE HIGH BY THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 255 AM EDT SATURDAY...
WARM FRONT ACROSS THE CENTRAL CWA THIS MORNING WILL LIFT NORTH AND
BASICALLY DISSIPATE BY AFTERNOON AS A GRADUALLY DEEPENING SOUTH/SW
FLOW DEVELOPS AROUND THE RIDGE OFFSHORE. BEHIND THE FRONT WILL SEE A
CONTINUED INFLUX OF WARMER AND MORE HUMID AIR WHICH PROVIDED ENOUGH
HEATING SHOULD SPARK ANOTHER ROUND OF SHRA/TSRA INTO THIS EVENING.
HOWEVER IN THE WAKE OF THE BOUNDARY...FOCUS LIKELY TIED MORE TO
OROGRAPHICS IN THE WEST AND OLD OUTFLOW IN THE EAST...PRODUCING A
MORE SCATTERED NATURE COVERAGE PER LATEST HRRR AND LOCAL WRF SOLNS.
APPEARS DEVELOPING SW FLOW AND HIGHER THETA-E MOUNTAINS SHOULD
SUPPORT BETTER COVERAGE NEAR THE BLUE RIDGE AND PERHAPS THE NW
WHERE WILL BE CLOSEST TO THE RESIDUAL FRONT. THUS MAY INCLUDE SOME
LOW AFTERNOON LIKELY POPS IN SPOTS ALONG THE RIDGES...WITH MAINLY
CHANCE COVERAGE ELSW WITH SOME OF THIS DEVELOPING LATER THIS
MORNING AS HEATING GETS GOING. LATEST FORECAST SOUNDINGS ALSO SHOW
WEAK MID LEVEL STEERING OF AROUND 10 MPH AND VERY MOIST PWATS OF
1.75 INCHES OR BETTER SO SLOW MOVING HEAVY RAINERS A THREAT
ESPCLY IF THINGS BAND UP ALONG THE RIDGES. DEGREE OF CLOUD COVER
TRICKY BY AFTERNOON WITH GUIDANCE SUGGESTING SOME BREAKS BUT THEN
QUICKLY DEVELOP CONVECTION WHICH MAY CURTAIL TEMP RISES. LATEST
MAV MOS LOOKS TOO WARM GIVEN EARLY CLOUDS AND AFTERNOON SHRA WHILE
THE MET TOO SLOW TO EXIT THE WEAK WEDGE. THUS GOING IN BETWEEN AND
CLOSER TO THE ENSEMBLE HIGHS WHICH PUTS THE WEST IN THE 76-82
RANGE AND MAINLY MID/UPR 80S EAST.
UPPER RIDGE OFFSHORE SHIFTS FARTHER WEST OVERNIGHT PUSHING THE
LINGERING DEEPER MOISTURE AXIS ALONG THE WESTERN SLOPES FARTHER
INLAND. THIS ALONG WITH SLIGHTLY HIGHER 5H HEIGHTS SHOULD END MOST
CONVECTION THIS EVENING ALLOWING FOR MOSTLY CLEAR TO PC SKIES
OVERNIGHT WITH SOME PATCHY FOG AROUND...AND ONLY AN ISOLATED SHRA
THREAT FAR WEST. WILL BE QUITE WARM AND MUGGY WITH LOWS 65-72
UNDER A MOIST AND SOUPY ENVIRONMENT IN THE WAKE OF ANY EARLIER
STORMS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
SEVERAL WEATHER FEATURES WILL CONVERGE OVER THE MID ATLANTIC REGION
AND KEEP THE CHANCES FOR SHOWERS AND THUNDERSTORMS IN THE FORECAST
THROUGH EARLY NEXT WEEK. AN UPPER LEVEL TROUGH OVER THE GREAT LAKES
AND A VORTICITY AXIS IN THE OHIO VALLEY WILL SLOWLY MOVE TO THE EAST
THROUGH THE PERIOD. AN UPPER LEVEL RIDGE...CURRENT OVER THE
REGION...WILL DRIFT TO THE SOUTH ALLOWING THE VORTICITY AXIS TO MOVE
OVER THE MOUNTAINS SUNDAY AND THE UPPER LEVEL TROUGH TO MOVE INTO
THE REGION MONDAY AND TUESDAY. WITH THE ADDITION OF SHORT WAVES
COMING AROUND THE UPPER LEVEL RIDGE AND A SURFACE LEE TROUGH IN THE
PIEDMONT...SCATTERED SHOWERS AND THUNDERSTORMS WILL REMAIN IN THE
FORECAST THROUGH THE PERIOD. WILL KEEP THE HIGHEST POPS DURING PEAK
HEATING AND MAINLY OVER THE MOUNTAINS SUNDAY AND MONDAY. ANY STRONG
STORMS THAT DEVELOP DURING THIS PERIOD WILL MOVE SLOW AND COULD
RESULT IN LOCALIZE FLASH FLOODING.
SCATTERED SHOWERS SHOULD HELP COOL AFTERNOON TEMPERATURES...BUT
UNTIL THEY DO...AFTERNOON TEMPERATURES WILL RUN ABOVE NORMAL BY 5F
TO 10F. IF THESE SHOWERS COOLING THE TEMPERATURES...RELATIVE
HUMIDITY WILL INCREASE...RESULTING IN MUGGY AND UNCOMFORTABLE
CONDITIONS. MOS GUIDANCE TEMPERATURES ARE SIMILAR...THERE I DID NOT
STRAY TO FAR FROM THEM.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 300 PM EDT FRIDAY...
BROAD UPPER RIDGE REMAINS OVER THE SOUTHEAST UNITED STATES. RIDGE
FLATTENS ON THURSDAY AND FRIDAY. SURFACE FRONT DROPS THROUGH SOUTH
INTO THE MID ATLANTIC REGION BY FRIDAY. CHANCE OF SHOWERS AND
THUNDERSTORMS WILL IMPROVE THURSDAY AND FRIDAY AHEAD OF THE FRONT.
OTHERWISE NO DISTINCT FEATURES TO HELP ORGANIZE ANY THUNDERSTORMS
TUESDAY AND WEDNESDAY. HOWEVER...AIR MASS WILL BE WARM AND UNSTABLE
WITH 850 MB TEMPERATURES IN THE +18 TO +20 RANGE. WILL KEEP DAILY
PROBABILITY OF AFTERNOON AND EVENING THUNDERSTORMS IN THROUGH THE
PERIOD. TEMPERATURES WILL REMAIN SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 645 AM EDT SATURDAY...
SHOWERS CONTINUE ALONG THE SOUTHERN BLUE RIDGE ATTM AND EXPECT
SOME THIS COVERAGE MAY AFFECT KBCB/KROA OVER THE NEXT FEW HOURS
BEFORE FADING. OTRW EXPECT A VARIETY OF CIGS AND VSBYS ACROSS THE
REGION EARLY ON...RANGING FROM IFR/MVFR ALONG AND EAST OF THE BLUE
RIDGE TO MAINLY VFR OVER THE WEST. MAY ADD IN A VCSH MENTION AT
KBCB AND KROA THIS MORNING BEFORE THINGS MIX OUT A BIT TO PERHAPS
A PERIOD OF VFR AT ALL LOCATIONS BEFORE RENEWED CONVECTION GETS
GOING AFTER MIDDAY. SHOWERS AND STORMS WILL AGAIN BE POSSIBLE BY
EARLY AFTERNOON ESPCLY OVER THE WEST WITH MORE WIDELY SCATTERED
COVERAGE LIKELY ACROSS EASTERN LOCATIONS. APPEARS THAT WITH
ENOUGH HEATING MAY HAVE DECENT COVERAGE ESPCLY ACROSS THE
MOUNTAINS SO ENOUGH CONFIDENCE TO INCLUDE AT LEAST A VCTS OR
PREVAILING SHRA MENTION OVER A FEW LOCATIONS IN THE WEST AND VCSH
OUT EAST IN THE AFTERNOON. THESE STORMS MAY BE SLOW MOVING WITH
PERIODS OF MVFR/IFR POSSIBLE PENDING THE DEGREE OF ORGANIZATION
LATER ON. EXPECTING SHRA/TSRA TO FADE A BIT SOONER THIS EVENING
BEFORE GIVING WAY TO VFR BEFORE FOG DEVELOPS MAINLY AFTER
MIDNIGHT ESPCLY IN THE VALLEYS AND WHERE EARLIER RAIN OCCURRED.
THE FRONT WILL CONTINUE TO LIFT NORTH DURING THE REMAINDER OF THE
WEEKEND. SHRA/TSRA COVERAGE WILL CONTINUE TO TREND MORE DIURNAL
AND ALONG THE MOUNTAIN RIDGES. MOST AREAS WILL EXPERIENCE VFR
CONDITIONS OUTSIDE OF THE HEAVIER SHRA/TSRA. LATE NIGHT IFR/MVFR
MOUNTAIN AND RIVER VALLEY FOG WILL BE POSSIBLE.
EARLY NEXT WEEK...HIGH PRESSURE GRADUALLY BUILDS INTO THE AREA
WITH PROGRESSIVELY MILDER TEMPERATURES AND A STRONG CAPPING
INVERSION ALOFT. CONDITIONS WILL BE MAINLY VFR EXPECT BRIEFLY
UNDER THOSE ISOLATED AREAS THAT RECEIVE A MODERATE TO HEAVY SHOWER
OR STORM.
&&
.EQUIPMENT...
NOAA ALL HAZARDS RADIO FOR THE HINTON TRANSMITTER REMAINS OFF THE
AIR DUE TO COMMERCIAL POWER NOT REACHING THE SITE.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH
SHORT TERM...RCS
LONG TERM...AMS
AVIATION...DS/JH/KK
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS RENO NV
201 PM PDT SAT JUL 14 2012
.SHORT TERM...
CURRENT WATER VAPOR IMAGERY DEPICTS A VERY DRY AIRMASS ALOFT THAT
HAS MOVED ACROSS WESTERN NEVADA OVERNIGHT AND THIS MORNING.
COMPARED TO YESTERDAY MORNING, THE 12Z OBSERVED PRECIPITABLE
WATER AT KRNO DROPPED 0.20 INCHES (TO 0.37 IN). WITH THE DEEPER
MOISTURE DISPLACED TO THE EAST, CONVECTION HAS BEEN A LOT SLOWER
TO DEVELOP THIS AFTERNOON. BASED ON THE LATEST HRRR FORECAST,
VISIBLE SATELLITE AND RADAR TRENDS, DECIDED TO TRIM BACK COVERAGE
OF THUNDERSTORMS FOR THIS AFTERNOON AND EVENING. THE BEST CHANCE
WILL BE ACROSS MINERAL, EASTERN MONO AND SOUTHEASTERN CHURCHILL
COUNTIES WHERE THE LATEST SPC MESOANALYSIS SHOWS MUCAPES OF AROUND
500 J/KG. WITH LITTLE IN THE WAY OF SHEAR, ANY STORMS THAT FORM
WILL BE PULSE STORMS THAT WILL SLOWLY DRIFT TO THE EAST-NORTHEAST.
ON SUNDAY, THE 12Z GFS/NAM/ECMWF ARE IN GOOD AGREEMENT THAT THE
AREA OF LOW PRESSURE OVER CENTRAL OREGON WILL LIFT TO THE
NORTHEAST WHILE A WEAK AREA OF LOW PRESSURE DEVELOPS NEAR THE
CENTRAL CALIFORNIA COAST. THIS WILL SET UP AN AREA OF DEFORMATION
ACROSS THE RENO CWA FROM TAHOE NORTHEAST TO WINNEMUCCA. SOUTH OF THIS
BOUNDARY, THE FLOW WILL TURN MORE SOUTHERLY, ALLOWING MONSOON
MOISTURE TO BUILD BACK ACROSS SOUTHEASTERN HALF OF THE CWA WITH
MODEL PWATS INCREASING TO NEAR 0.75 INCHES. THE EXISTING FORECAST
LOOKS GOOD WITH ISOLATED COVERAGE SOUTH OF I-80 AND SCATTERED
STORMS SOUTH OF US-50. THE STORMS ACROSS MINERAL AND MONO COUNTIES
WILL BE ON THE WET SIDE, WITH WET/DRY HYBRID STORMS CLOSER TO THE
MOISTURE BOUNDARY BETWEEN I-80 AND US-50 (SEE THE FIRE WEATHER
DISCUSSION BELOW FOR MORE DETAILS).
THE WEAKNESS NEAR THE CALIFORNIA COAST WILL WEAKEN ON MONDAY AS A
STRONGER AREA OF LOW PRESSURE BUILDS SOUTH ACROSS WESTERN
WASHINGTON AND OREGON. THIS WILL TURN THE UPPER LEVEL FLOW BACK TO
THE SOUTHWEST, USHERING IN DRIER AIR ACROSS THE RENO CWA. THE BEST
CHANCE FOR ANY CONVECTION WILL BE ACROSS MINERAL AND MONO
COUNTIES, CLOSER TO THE DEEPER MOISTURE.
THE AREA OF LOW PRESSURE WILL CONTINUE TO SLIDE SLOWLY SOUTH
ACROSS WESTERN OREGON ON TUESDAY. THIS WILL KEEP DRY SOUTHWEST
FLOW IN PLACE. DEPENDING ON THE PLACEMENT OF THE LOW, THERE IS A
VERY SMALL CHANCE THAT EXTREME NORTHERN LASSEN COUNTY AND THE
SURPRISE VALLEY COULD SEE A PASSING SHOWER ON TUESDAY AFTERNOON
SO A SLGT CHANCE WAS INTRODUCED WITH THIS PACKAGE FOR THOSE AREAS.
MYRICK
.LONG TERM...WEDNESDAY THROUGH SATURDAY...
A TROUGH LOCATED OVER THE PACIFIC NORTHWEST WILL CREATE A DRY AND
STABLE SOUTHWEST FLOW ALOFT WEDNESDAY AND THURSDAY. NUMERICAL
GUIDANCE DIFFERS FOR FRIDAY AND SATURDAY...SOME SOLUTIONS BRING
THE TROUGH EASTWARD WHILE OTHER SOLUTIONS MOVE IT WESTWARD AND
BUILD THE RIDGE OVER THE EASTERN SIERRA AND WESTERN NEVADA. THE
OVERALL CONSENSUS IS FOR A DRY FORECAST WITH A WARMING TREND
THROUGH SATURDAY...WHICH IS ALREADY COVERED WELL BY THE ONGOING
FORECAST.
ONE WILD CARD IS THE SLIGHT CHANCE THAT MOISTURE FROM THE REMNANTS
OF HURRICANE FABIO COULD BE DRAWN NORTHWARD FRIDAY. TWO RECENT RUNS
OF THE GFS ARE THE ONLY ONES SHOWING THIS SOLUTION. WITH FABIO
CURRENTLY LOCATED 550 MILES SSW OF THE SOUTHERN TIP OF
BAJA-CALIFORNIA CONFIDENCE IS VERY LOW IN THIS SCENARIO. FOR NOW A
SLIGHT CHANCE OF THUNDERSTORMS WAS INTRODUCED FRIDAY FOR MONO
COUNTY. JCM
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL OVERALL THROUGH THE WEEKEND AND INTO
NEXT WEEK. THUNDERSTORMS ARE POSSIBLE SUNDAY AFTERNOON FROM I-80
SOUTHWARD. IN THE VICINITY OF THESE STORMS THE CIG/VSBYS SHOULD BE
AOA 5000/5 WITH GUSTY SFC WINDS.
FOR THE TERMINALS ISOLATED STORMS ARE POSSIBLE SUNDAY AFTERNOON AND
EARLY EVENING IN THE VICINITIES OF KTRK..KTVL AND KRNO...WITH
SOMEWHAT BETTER POTENTIAL FOR THUNDERSTORMS IN THE VICINITY OF KMMH.
JCM
&&
.FIRE WEATHER...
HAVE TRIMMED BACK THUNDERSTORM COVERAGE THIS AFTERNOON BASED ON
LATEST RADAR AND SATELLITE TRENDS TO ENCOMPASS EASTERN MONO COUNTY
INTO MINERAL AND EASTERN CHURCHILL COUNTIES. WITH PLENTY OF MID AND
UPPER LEVEL DRY AIR WORKING INTO THE REGION IT HAS SUPPRESSED
THUNDERSTORM DEVELOPMENT.
TYPICAL AFTERNOON ZEPHYR WINDS CAN BE EXPECTED WITH GUSTS OF 25 TO
30 MPH LATE THIS AFTERNOON AND INTO THE EARLY EVENING. THESE GUSTS
WILL CORRESPOND WITH HUMIDITY VALUES AROUND 10-15% WITH LOCALLY
CRITICAL CONDITIONS POSSIBLE. HOWEVER, THESE WILL NOT BE WIDESPREAD
ENOUGH TO WARRANT ANY RED FLAG WARNINGS TODAY. AFTERNOON WESTERLY
WINDS CAN BE EXPECTED AGAIN SUNDAY, BUT WILL BE ABOUT 5 MPH LESS IN
SPEED.
A PIECE OF ENERGY AND WEAK DEFORMATION BAND WILL HELP TO FOCUS
THUNDERSTORM DEVELOPMENT SUNDAY AFTERNOON WITH ISOLATED COVERAGE
POSSIBLE BETWEEN INTERSTATE 80 AND HIGHWAY 50 AND SCATTERED COVERAGE
SOUTH OF HIGHWAY 50. THE DEEPEST MOISTURE WILL BE SOUTH OF HIGHWAY
50 AND EAST OF HIGHWAY 95, SO STORMS THROUGH THIS AREA WILL BE WET.
NORTH AND WEST OF THERE, A HYBRID OF STORMS ARE POSSIBLE WITH THE
POTENTIAL FOR A DRY LIGHTNING STRIKE OUTSIDE OF THE WET THUNDERSTORM
CORE. THIS COULD START NEW FIRES, BUT WITH THE SMALL AREA OF HYBRID
STORMS, AM NOT PLANNING ANY RED FLAG WARNINGS AT THIS TIME. IN
ADDITION, WATCHING HOW THE DRY AIR WORKING INTO CALIFORNIA AND
WESTERN NEVADA HAS SQUELCHED THUNDERSTORM DEVELOPMENT TODAY, AM A
BIT CONCERNED THAT MODELS MAY BE OVERDOING THE CONVECTIVE POTENTIAL
SUNDAY AND COVERAGE MAY NEED TO BE TRIMMED A BIT. DF
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS DENVER CO
343 PM MDT SAT JUL 14 2012
.SHORT TERM...THE UPPER LEVEL RIDGE OVER EASTERN CO TONIGHT WILL
CONTINUE TO SLOWLY SHIFT TO THE EAST FOR SUNDAY. AS A RESULT...THE
SUBTROPICAL MOISTURE OVER WESTERN CO WILL CONTINUE TO SPREAD EAST
INTO THE NORTHEASTERN PLAINS AS WELL. THE LATEST HRRR CONFINES THE
DEEP CONVECTION TO THE HIGH COUNTRY TONIGHT. WITH THE RIDGE
OVERHEAD IT WILL BE TOO STABLE OVER THE NORTHEAST PLAINS FOR
THUNDERSTORMS. WL KEEP ISOLD POPS IN ZONE 38 BUT DROP IT FOR THE
REMAINDER THE URBAN CORRIDOR. ON SUNDAY...PRECIPITABLE WATER VALUES
CONTINUE TO CLIMB WITH VALUES CLOSE TO ONE INCH IN THE AFTERNOON.
FCST CAPES IN THE MOUNTAINS 300-400 J/KG WITH VALUES 800-1100 J/KG
OVER THE URBAN CORRIDOR AND NORTHEAST PLAINS. ALTHOUGH IT WILL BE
HOT AGAIN SUNDAY AFTN...CLOUD COVER AND THUNDERSTORMS SHOULD
INHIBIT HEATING SLIGHTLY IN THE AFTERNOON.
.LONG TERM...591 RIDGE OVER THE WESTERN GREAT PLAINS CONTINUES ITS
SLOW EASTWARD PROGRESSION OVER THE GREAT PLAINS THROUGH MID-WEEK.
THE SHIFT ALLOWS SOUTHWESTERLY FLOW ON THE WEST SIDE OF THIS RIDGE
TO TRANSPORT INCREASING AMOUNTS OF MOIST SUBTROPICAL AIR UP OVER
COLORADO DURING THE FIRST HALF OF THE WEEK. THIS LATEST PLUME OF
MONSOONAL MOISTURE LOOKS NEITHER AS MOIST OR AS DEEP AS THE PLUME
WE DEALT WITH A WEEK OR SO AGO WHEN STORMS BROUGHT HEAVY RAIN AND
RESULTING FLASH FLOODING TO THE FORECAST AREA. THE AXIS OF THE
500-700MB MOISTURE STREAM STARTS OUT OVER THE WESTERN VALLEYS OF
COLORADO MONDAY MORNING AND THROUGH THE DAY MODELS SHOW IT
SHIFTING EAST OVER THE MTNS AND AND FRONT RANGE FOOTHILLS WITH
PRECIPITABLE WATER VALUES UP AROUND 1.25 INCHES OVER THE FRONT
RANGE BY LATE IN THE DAY. MODELS ALSO SHOW A WEAK MID-LEVEL SHORTWAVE
TROUGH/THERMAL TROUGH EMBEDDED IN THE SOUTHWEST FLOW ALOFT
PASSING OVER THE NORTH CENTRAL MTNS IN THE AFTERNOON AND OVER THE
NORTHEAST PLAINS MONDAY EVENING WHICH SHOULD FURTHER ENHANCE
T-STORM DEVELOPMENT IN THE AREA. HIGH SCATTERED POPS LOOK GOOD FOR
NOW FOR THE MTNS AND NEARBY PLAINS...WITH CHANCES FOR PCPN
DECREASING FARTHER OUT ACROSS THE PLAINS WHERE THE AIRMAS STILL
APPEARS WEAKLY CAPPED. COULD SEE LOCALLY HEAVY RAINFALL FROM
STORMS IN AND NEAR THE FRONT RANGE. SHEAR NOT ALL THAT GREAT...SO
THE CHANCE FOR SEVERE APPEARS LOW.
FOR THE REMAINDER OF THE WEEK...TUESDAY LOOKS TO BE NEARLY AS
WET/STORMY AS ON MONDAY WITH THE MONSOON MOISTURE PLUME
CONTINUING TO CREEP EASTWARD OVER THE STATE. ONCE AGAIN COULD SEE
A FEW LATE STORMS PRODUCING LOCALLY HEAVY RAINFALL...MAINLY OVER
AND NEAR THE MTNS. SHOULD ALSO SEE RAIN CHANCES INCREASE ON THE
PLAINS WITH INFLUX OF LOW-LEVEL MOISTURE WITH A GUSTY SOUTHEAST
FLOW. CAN`T RULE OUT AN ISOLATED SEVERE T-STORM ON THE PLAINS
WITH BETTER SHEAR AND INSTABILITY IN PLACE. BY WEDNESDAY...THE
MONSOON MOISTURE FLOW APPEARS TO WEAKEN WITH THE UPPER RIDGE OUT
EAST WEAKENING SOME. THEREFORE T-STORM CHANCES SHOULD GO DOWN AND
WITH MORE SUNSHINE TEMPERATURES WILL BEGIN TO NUDGE UPWARD.
THURSDAY AND BEYOND...MEDIUM RANGE MODELS SHOW THE GREAT PLAINS
RIDGE STRENGTHENING AGAIN AS IT BEGINS TO BUILD WESTERN TOWARDS
THE ROCKY MTN REGION. INCREASE SOUTHERLY FLOW AHEAD OF THIS RIDGE
APPEARS TO BRING ANOTHER SURGE OF MOIST SUBTROPICAL AIR UP INTO
THE FOUR CORNERS AREA BY WEEK`S END...AND POSSIBLY OVER THE
REMAINDER OF COLORADO BY THE WEEK. SO POSSIBLY ANOTHER SHOT FOR
DECENT RAINFALL BY END OF THE EXTENDED PERIOD.
&&
.AVIATION...GUSTY SELY WINDS WILL CONTINUE INTO EARLY EVENING
THEN SHIFT TO MORE OF A SOUTHERLY DIRECTION AND DECREASE AFTER
06Z. DO NOT ANTICIPATE TSTMS IN ANY OF THE DENVER TAFS THIS
AFTERNOON AND EVENING...WITH BETTER POTENTIAL FOR STORMS SUNDAY
AFTN. VFR CONDITIONS WITH NO RESTRICTIONS OVER THE NEXT 18Z HOURS
WITH JUST A SLIGHT CHANCE OF STORMS AFTER 20Z SUNDAY.
&&
.HYDROLOGY...THERE WILL BE A SLIGHT CHANCE OF TSTMS IN THE BURN
AREAS UNTIL AROUND 04Z...ALTHOUGH THE THREAT IS LOW...THE STORMS
COULD PRODUCE 0.10-0.20 INCHES OF RAINFALL IN 30 MINUTES.
INCREASING CHANCE OF TSTMS SUNDAY AFTERNOON WITH A GREATER
POTENTIAL FOR BRIEF HEAVY RAINFALL AFTER 20Z SUNDAY.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...COOPER
LONG TERM....BAKER
AVIATION...COOPER
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1131 AM MDT SAT JUL 14 2012
.AVIATION...VFR CONDITIONS EXPECTED AT TAF SITES TODAY AND TONIGHT.
SCATTERED TO NUMEROUS TSRA WILL DEVELOP ALONG THE CONTINENTAL
DIVIDE THIS AFTERNOON AND EVENING...WITH ISOLATED TO SCATTERED
STORMS ACROSS THE SOUTHEAST MOUNTAINS...DRIFTING OFF INTO THE
NEIGHBORING VALLEYS DURING THE AFTERNOON. WILL MAINTAIN VCTS IN
THE ALS TAF 20Z-02Z TIME FRAME...THOUGH AGAIN GUSTY WINDS TO 40 KTS
WILL BE MORE OF A THREAT THAN LOW CIGS/VIS. -TSRA WILL DIMINISH
QUICKLY AFTER 02Z...WITH CONVECTIVE DEBRIS CLOUD COVER DECREASING
GRADUALLY THROUGH THE OVERNIGHT HOURS.
&&
.PREV DISCUSSION... /ISSUED 354 AM MDT SAT JUL 14 2012/
SHORT TERM...
(TODAY AND TONIGHT)
PRECIPITABLE WATERS IN 00Z SOUNDINGS AND IN DERIVED
SATELLITE PRODUCTS RUNNING FROM 50 TO 75 PERCENT OF NORMAL ACROSS
THE EASTERN HALF OF THE FORECAST AREA...TO NEAR 130% OF NORMAL
ACROSS THE SOUTHWEST MOUNTAINS. DEEPEST FETCH OF MONSOON MOISTURE
IS CURRENTLY ORIENTED ALONG AN AXIS FROM AZ THROUGH UT INTO ID AND
WESTERN WY. UPPER RIDGE AXIS IS PROGGED TO SHIFT SLOWLY EASTWARD
TODAY PUTTING SOUTH CENTRAL AND SOUTHEAST COLORADO UNDER MORE OF A
SOUTH TO SOUTHWEST FLOW ALOFT. THIS WILL HELP SPEED UP STORM
MOTIONS TODAY (TO THE NORTH NORTHEAST AROUND 10 MPH)...AS WELL AS
EDGE THE MOISTURE AXIS EASTWARD. NAM12 AND HRRR KEEP DEW POINTS
TODAY IN THE LOWER 40S ACROSS CHAFFEE AND LAKE COUNTIES...UP FROM
YESTERDAYS VALUES IN THE 20S AND EVEN SOME TEENS. NAM12 SFC DEW
POINTS ARE STILL LIKELY A BIT OVERDONE...BUT THINK AFTERNOON DEW
POINTS MAINTAINING IN THE 30S LOOKS PLAUSIBLE TODAY AS THE
MOISTURE PLUME SHIFTS EASTWARD. MEANWHILE...SOUTHEAST MTS/PIKES
PEAK REGION SHOULD SEE ANOTHER DAY OF SFC DEW POINTS DROPPING INTO
THE 30S BY AFTERNOON...WHICH SHOULD HELP CUT BACK ON CAPE VALUES
AND KEEP STORMS MORE ISOLATED IN NATURE. WITH STORM MOTIONS TO THE
NORTH OR NORTHEAST...THEY MAY HAVE A SLIGHTLY BETTER CHANCE OF
DRIFTING OFF THE SE MTS INTO THE I-25 CORRIDOR. BUT WITH DRY
SUBCLOUD LAYER...THINK THAT MAIN THREAT WILL BE GUSTY WINDS UP TO
50 MPH...BRIEF LIGHT TO MODERATE RAINFALL AND LIGHTNING...BEFORE
THEY QUICKLY DIMINISH AS THEY MOVE ONTO THE ADJACENT PLAINS.
MEANWHILE...THE HIGHER PRECIPITABLE WATERS ACROSS THE SOUTHWEST AND
CENTRAL MOUNTAINS WILL LEAD TO A BETTER CHANCE FOR HEAVY RAINFALL
OUT THAT WAY...THOUGH WITH STORM MOTIONS A LITTLE FASTER
TODAY...THIS SHOULD KEEP THE FLASH FLOOD THREAT MORE LOCALIZED TO
BURN SCARS AND SUSCEPTIBLE AREAS SUCH AS THE CHALK CLIFFS. ONCE
AGAIN...NOT ENOUGH OF A THREAT TO WARRANT ANY FLASH FLOOD
WATCHES AT THIS POINT.
MAX TEMPERATURES ARE LIKELY TO BE SIMILAR TO THOSE OF
YESTERDAY...PERHAPS A DEGREE OR TWO WARMER ALONG THE I-25 CORRIDOR
DUE TO SOME STRONGER WINDS AND SLIGHTLY DEEPER MIXING. ONCE
CONVECTION DEVELOPS OVER THE MTS THOUGH...CLOUD COVER FROM
THUNDERSTORM ANVILS MAY TEMPER FURTHER WARMING...WHICH SHOULD KEEP
THE I-25 CORRIDOR FROM SEEING TEMPS HIT 100. FARTHER TO THE EAST
HOWEVER...TEMPS WILL LIKELY BREAK THE CENTURY MARK ONCE AGAIN.
THUNDERSTORMS WILL DECREASE IN COVERAGE DIURNALLY SATURDAY
NIGHT...THOUGH WILL KEEP ISOLATED POPS GOING ALONG THE CONTINENTAL
DIVIDE WHERE ACTIVE MONSOON PLUME WILL BE OVERHEAD. MIN TEMPS WILL
BE ON THE WARM SIDE ONCE AGAIN DUE TO CONVECTIVE DEBRIS CLOUDINESS
LINGERING OVER THE REGION. -KT
LONG TERM...
(SUNDAY THROUGH SATURDAY)
..THREAT OF MORE HEAVY RAIN NEXT WEEK...
NO BIG CHANGES TO THE EXTENDED FORECAST. SUNDAY STILL LOOKS TO BE THE
WARMEST DAY AS H7 TEMPS CLIMB TO 18 DEG C OR HIGHER OVER THE SRN
FRONT RANGE. BULK OF THE PRECIP SHOULD AGAIN BE CONFINED TO THE
CONTDVD...AND WITH SRLY TO SW WINDS...SHOULD EASILY APPROACH OR
EXCEED THE 100 DEG MARK OVR THE ERN PLAINS.
MONDAY...A WEAK FRONTAL SURGE PUSHES ACROSS SERN CO IN THE
AFTERNOON...AS THE MONSOONAL PLUME SHIFTS A BIT EWD INTO CENTRAL
CO. THE INCREASE IN MID LEVEL MOISTURE ALONG WITH INCREASED
UPSLOPE FROM THE SURGE SHOULD SPARK AN INCREASE INCONVECTION ALONG
THE ERN MTS AND ADJACENT PLAINS BY LATE MON AFTERNOON OR EARLY EVE.
HOW QUICKLY THIS OCCURS WILL DETERMINE HIGH TEMPS FOR THE
PLAINS...AS THE LESS AGGRESSIVE GFS SUGGESTS TEMPS NR 100 DEG AGAIN
FOR KPUB. HAVE KEPT CLOSER TO THE SLIGHTLY COOLER NAM/MET...WHICH
PROGS UPPER 90S FOR THE PLAINS.
BY TUE-WED...THE MONSOON IS IN FULL SWING...WITH THE PLUME OVR ERN
CO AS THE UPPER HIGH SHIFTS EWD TO THE SRN PLAINS. SHOULD SEE A
GOOD RAMP UP OF STORMS OVR THE ENTIRE AREA...AND STORMS PERSISTING
A BIT LATER INTO THE EVENING HOURS. FLASH FLOODING FOR THE FLOOD
PRONE AREAS WILL AGAIN BE THE CHIEF CONCERN. GREATEST THREAT ATTM
APPEARS TO BE CENTERED AROUND TUE EVENING...WHEN WE COULD SEE SOME
LOCAL QPF IN THE ONE TO TWO INCH RANGE.
BY THU-FRI...STILL A BIT OF UNCERTAINTY HOW THE SYNOPTIC PICTURE
EVOLVES. IT LOOKS LIKELY THAT THE HIGH WILL START TO SHIFT WWD
AGAIN...BUT TO WHAT EXTENT AND HOW IT WILL AFFECT THE MOISTURE
PLUME IS A BIT UP IN THE AIR. THE EC CONTINUES TO BE ON THE DRY
SIDE...WHILE THE GFS IS SLOWER TO STRENGTHEN THE HIGH OVR AREA AND
CONSEQUENTLY KEEPS MORE MOISTURE STREAMING UP FROM THE S ON THU
AND POSSIBLY INTO FRI. BY LATE IN THE PERIOD...A COMPLICATING
FACTOR IS THE POSSIBILITY OF SOME SUBTROPICAL MOISTURE BEING
CAUGHT UP IN THE UPPER FLOW...WHICH IS HINTED AT IN THE 00Z GFS.
FOR NOW...STUCK WITH THE ENSEMBLE GUIDANCE FOR THE LATTER PART OF
THE FORECAST...WHICH IS FAIRLY CLOSE TO CLIMATOLOGY FOR
POPS/TEMPS. 44
AVIATION...
VFR CONDITIONS EXPECTED AT TAF SITES. SCATTERED TO NUMEROUS
THUNDERSTORMS WILL DEVELOP ALONG THE CONTINENTAL DIVIDE THIS
AFTERNOON AND EVENING...WITH ISOLATED TO SCATTERED THUNDERSTORMS
ACROSS THE SOUTHEAST MOUNTAINS...DRIFTING OFF INTO THE NEIGHBORING
VALLEYS DURING THE AFTERNOON. KALS HAS THE BEST CHANCE OF SEEING AN
ISOLATED -TSRA AND WILL MAINTAIN VCTS IN THE TAF FOR THAT
SITE...WHERE BRIEF VFR CIGS/VIS WILL BE POSSIBLE WITH
THUNDERSTORMS. THERE WILL BE MUCH LESS OF A CHANCE FOR
THUNDERSTORMS TO HIT THE KCOS AND KPUB TAF SITES...SO WILL LEAVE ANY
MENTION OF TS OUT OF THOSE SITES FOR NOW. WINDS WILL INCREASE OUT
OF THE SOUTHEAST AT AROUND 15 KTS FOR BOTH KPUB AND KCOS DURING THE
AFTERNOON. -TSRA WILL DIMINISH QUICKLY AFTER 01-02Z...WITH
CONVECTIVE DEBRIS CLOUD COVER DECREASING GRADUALLY THROUGH THE
OVERNIGHT HOURS. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
10/23
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
514 PM CDT SAT JUL 14 2012
.DISCUSSION...
210 PM CDT
CONCERNS WITH THE FORECAST ARE CENTERED ON CONVECTION THROUGH THIS
EVENING...AND THEN HOT TEMPERATURES THE NEXT SEVERAL DAYS.
SHORT TERM...REST OF THIS AFTERNOON THROUGH SUNDAY...
TOWERING CUMULUS ALONG WITH SOME SCATTERED STORMS HAVE DEVELOPED
EARLY THIS AFTERNOON ACROSS MAINLY THE EASTERN HALF OF THE
FORECAST AREA ALONG AND AHEAD OF A SHEARED OUT UPPER IMPULSE AND
AN ELEVATED /850-700MB/ WIND AND MOISTURE CONVERGENCE ZONE. GIVEN
A FAIRLY UNSTABLE AIR MASS PER MODIFIED AMDAR SOUNDINGS AND RAP
ANALYSIS...WITH MLCAPE VALUES OF 1000 TO 1500 J/KG...THESE STORMS
SHOULD CONTINUE TO REGENERATE WITH THE FURTHER FOCI OF BOUNDARY
INTERACTIONS. HAVE ALREADY SEEN THE DIVERGENT VELOCITY SIGNATURES
ON RADAR UNDERNEATH THESE STORMS WITHIN JUST TWO RADAR
VCPS...SHOWING THE DOWNDRAFT POTENTIAL ONCE AGAIN. ENVIRONMENTAL
DCAPE VALUES ANALYZED BY THE RAP OF 700 TO 1000 J/KG ARE SLIGHTLY
LESS THAN YESTERDAY...BUT SUFFICIENT ENOUGH FOR A POSSIBLE
ISOLATED SEVERE GUST...INCLUDING IN NEARSHORE AREAS OF THE LAKE IN
ANY STORMS THAT DRIFT NORTHEAST OVER THAT AREA.
AN UPPER LEVEL SHORT WAVE...AS PART OF THE LARGER BROAD
TROUGH...IS MOVING SOUTHEAST ACROSS WESTERN WI EARLY THIS
AFTERNOON. THE INITIAL SURFACE BOUNDARY UNDERNEATH THIS IS HELPING
TO FOCUS SOME SCATTERED STORMS...WITH SIMILAR ML INSTABILITY OF
1000 TO 1500 J/KG. MORE DEVELOPMENT IS ANTICIPATED THROUGH EARLY
EVENING IN ADVANCE OF THIS AS CONVERGENCE IMPROVES...AND SOME OF
THIS MAY POTENTIALLY BE ALONG OUTFLOW THAT IS ALREADY INTO
NORTHWEST IL. EXPLICIT CONVECTIVE MODELS DO KEY IN ON SCATTERED
STORM DEVELOPMENT TOWARD THE I-39 CORRIDOR BY LATE AFTERNOON. WITH
THE SHORT WAVE AND FRONTAL APPROACH...ALONG WITH DEEP LAYER SHEAR
VALUES OF SEMI-DECENT 30 KT PROJECTED...THESE SHOWERS AND
STORMS HAVE POTENTIAL TO HANG ON LATER INTO THE EVENING.
THE COOL FRONT WILL MOVE THROUGH THE AREA LATE TONIGHT AND SUNDAY
MORNING...BUT WASHING OUT AS IT DOES. TEMPERATURES ON SUNDAY ARE
ACTUALLY EXPECTED TO BE SLIGHTLY HIGHER THAN TODAY...AND DEW
POINTS SHOULD BE CLOSE. THIS WILL AGAIN PROVIDE MODEST
INSTABILITY...BUT HEIGHT RISES ALOFT SHOULD TEMPER STORM
DEVELOPMENT. A ROGUE LATE AFTERNOON CELL OR TWO CANNOT BE RULED
OUT ALONG WEAK SURFACE CONVERGENCE...BUT HAVE NOT MENTIONED IN THE
FORECAST AT THIS TIME. HIGHS ON SUNDAY LOOK TO TOP OUT IN THE
LOWER TO MID 90S...WITH A LAKE BREEZE PROVIDING SOME COOLING FOR
DOWNTOWN CHICAGO AND NEARBY AREAS DURING THE AFTERNOON. THESE LAKE
SHORE AREAS STILL MAY REACH 90 OR NEAR IT BEFORE THE LAKE BREEZE
PUSHES THROUGH.
MTF
LONG TERM...SUNDAY NIGHT THROUGH SATURDAY...
THE UPPER LEVEL RIDGE REESTABLISHES ITSELF ACROSS THE CENTRAL US AS
THE TROUGH MOVES OFF TOWARD THE NEW ENGLAND AREA. A WEAKENING AREA
OF LOW PRESSURE MOVES NORTH OF THE GREAT LAKES MONDAY NIGHT...WHILE
ITS COLD FRONT SINKS SOUTH DOWN THE LAKE ON TUESDAY.
PRECIP CHANCES DIMINISH AS THE TROUGH DRIFTS EASTWARD SUNDAY NIGHT.
THE BEST CHANCE OF PRECIP IN THE EXTENDED IS ALONG THE COLD FRONT
LATE TUESDAY THROUGH WEDNESDAY. GUIDANCE DIFFERS ON THE SPEED OF
THE FRONT...WITH THE GFS BRINGING THE FRONT THROUGH MUCH FASTER THAN
THE ECMWF. GIVEN ISSUES WITH THE GFS LATELY...AND THE ECMWF HAVING
VERY CONSISTENT TIMING OVER THE PAST FEW DAYS...GOING WITH THE
SLOWER SOLUTION. BOTH MODELS INDICATE MOISTURE WILL POOL ALONG THE
FRONT...BUT THEN DISSIPATE AS THE FRONT ENTERS NORTHERN IL.
THEREFORE...KEPT BEST PRECIP CHANCES NORTH OF I-80. LIMITED ACTUAL
PRECIP CHANCES TO LESS THAN 50 PERCENT GIVEN THE MODEL TRENDS AND
DRY CONDITIONS.
HIGH PRESSURE BUILDS IN BEHIND THE FRONT...AND GUIDANCE SUGGESTS
RANDOM PERIODS OF PRECIP DURING THE LATTER HALF OF NEXT WEEK.
HOWEVER...WITH NO CLEAR SOURCE OF FORCING...QUESTIONABLE MOISTURE
SOURCES...AND DROUGHT CONDITIONS...DECIDED TO KEEP THE REMAINDER OF
THE EXTENDED DRY. AT THIS POINT THE BIGGER CRIME IS GETTING FOLKS
HOPES UP FOR RAIN ONLY TO DISAPPOINT.
HEAT BUILDS ACROSS THE REGION THROUGH TUESDAY. GUIDANCE SUGGESTS
THERE WILL ONLY BE A SMALL PUSH OF SLIGHTLY COOLER AIR BEHIND THE
FRONT...WITH WEDNESDAY LOOKING TO BE A BIT COOLER. HOWEVER 850 HPA
TEMPS BEGIN TO WARM ALMOST IMMEDIATELY WITH THE UPPER LEVEL RIDGE SW
OF THE CWA. THEREFORE...THE LATTER HALF OF NEXT WEEK LOOKS ABOVE
AVERAGE.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* SHRA/TSRA DIMINISHING ACROSS IMMEDIATE TERMINAL AREAS...WITH
FOCUS FOR CONTINUED ADDITIONAL DEVELOPMENT EAST THROUGH SOUTH OF
ORD/MDW NEXT FEW HOURS.
* OUTFLOW/LAKE BREEZE DISTURBED WIND FIELD GENERALLY EAST-
SOUTHEAST SHOULD GRADUALLY VEER MORE SOUTH-SOUTHEAST THROUGH
EARLY EVENING...THEN LIGHT SOUTHWEST OVERNIGHT.
RATZER
//DISCUSSION...UPDATED 18Z...
PRIMARY FORECAST CONCERN CONTINUES TO BE SHRA/TSRA REDEVELOPMENT.
MORNING TSRA SERVED TO STABILIZE THE ATMOSPHERE TEMPORARILY. SO
FAR THINGS HAVE BEEN SLOW TO RECOVER. THE TSRA ACTIVITY IN EAST
CENTRAL ILLINOIS INTO CENTRAL INDIANA IS ALSO HELPING TO SLOW
REDEVELOPMENT OVER NORTHERN ILLINOIS. AN UPPER LEVEL TROUGH IS
STILL OVER THE AREA PROVIDING SUPPORT FOR TSRA AND MODELS CONTINUE
TO INDICATE REDEVELOPMENT. HAVE OPTED TO LEAVE TSRA MENTION IN THE
TAFS FOR NOW...BUT HAVE ADJUSTED THE TIMING TO LATER...WHICH
SHORTENS THE TIME FRAME...AND WILL MONITOR THE SITUATION CLOSELY
FOR FURTHER UPDATES.
WINDS WILL BE LIGHT AND SOMEWHAT VARIABLE. BY MID TO LATE
AFTERNOON A SOUTHWESTERLY DIRECTION SHOULD BE FAVORED. THE
QUESTION IS THE WHETHER THE LAKE BREEZE WILL MAKE IT AS FAR INLAND
AS ORD OR MDW.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM-HIGH CONFIDENCE IN WIND TRENDS OUTSIDE OF LINGERING
OUTFLOW EFFECTS.
* MEDIUM-HIGH CONFIDENCE IN PRECIP/TSRA TRENDS.
RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT THROUGH TUESDAY...VFR.
TUESDAY NIGHT AND WEDNESDAY...CHANCE OF TSRA...OTHERWISE VFR.
THURSDAY AND FRIDAY...VFR.
MDB
&&
.MARINE...
145 PM CDT
LOW PRESSURE ACROSS LAKE SUPERIOR WILL CONTINUE TO MOVE EAST
THROUGH SUNDAY. THIS WILL STEER A COOL FRONT ACROSS THE LAKE LATE
TONIGHT. AHEAD OF THIS WILL BE SOME SCATTERED STORMS...SOME OF
WHICH ARE LIKELY TO BE GUSTY BASED ON THE ENVIRONMENT. THESE WILL
BE MOST FAVORED ACROSS THE SOUTHERN THIRD OF THE LAKE INCLUDING
NEAR SHORE AREAS OF IL...IN...AND SOUTHWEST MI. WINDS BEHIND THE
FRONT ON SUNDAY WILL BECOME LIGHT AND BEGIN TURNING BACK TO
SOUTHERLY ALREADY BY AFTERNOON. SOUTHWEST WINDS WILL INCREASE ON
MON...WITH OPEN WATER LOCATIONS ACROSS THE NORTH LIKELY REACHING
30 KT DURING MON NIGHT. A COOL FRONT WILL SLOWLY WORK SOUTH
ACROSS THE LAKE ON TUESDAY AND TUESDAY NIGHT. THIS WILL SHIFT
WINDS TO THE NORTH AND PROVIDE A FOCUS FOR SCATTERED THUNDERSTORMS
ONCE AGAIN.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
302 PM CDT SAT JUL 14 2012
.DISCUSSION...
ISSUED 236 PM CDT SAT JUL 14 2012
SCATTERED SHOWERS ACROSS CENTRAL ILLINOIS CONTINUE...WITH VERY
LITTLE MOVEMENT UNDER A WEAK UPPER LEVEL TROF. CONVECTIVE ACTIVITY
TO THE NW THIS MORNING SHOWING UP AS A LITTLE WEAK VORTEX ON VIS
SAT IMAGERY THIS AFTERNOON. BECAUSE OF THAT...HAVE MADE A COUPLE
OF CHANGES TO THE POPS FOR THE OVERNIGHT. OTHER THAN
THAT...FORECAST IS MOSTLY DRY BEYOND TONIGHT. NEXT CHANCE FOR
PRECIP COMES MID WEEK NEXT WEEK. ECMWF NOW HAVING SIMILAR ISSUE TO
THE LAST FEW RUNS OF THE GFS...SO KEEP SCALING BACK THE EXTENDED
POPS
SHORT TERM...TONIGHT AND TOMORROW...
FIRST CONCERN IS THE SMALL VORTEX TO THE NW MOVING NEAR THE REGION
IN THE OVERNIGHT. NEITHER HRRR NOR THE 4KM WRF ARE PICKING UP ON
THE SYSTEM...BUT THE AVAILABLE MOISTURE HAS NOW BEEN A BIT
ALTERED... PARTICULARLY IN THE EASTERN HALF OF THE CWA. FEEL LESS
LIKE THE SHOWERS AFTER 00Z WILL BE LIMITED TO REMNANTS FROM
TODAY...AND HAVE EXPANDED THE CHANCE POPS TO COVER THE ENTIRE
OVERNIGHT. IN ANY SPOTS THAT CLEAR OUT IN THE
OVERNIGHT...PARTICULARLY IN THE EAST WHERE THE BOUNDARY LAYER
MOISTURE HAS BEEN SIGNIF INCREASED BY THE SHOWERS AND
THUNDERSTORMS THIS AFTERNOON...PATCHY FOG WILL BE POSSIBLE IN THE
EARLY MORNING...AND HAVE PLACED THE MENTION IN THE GRIDS FOR A
COUPLE HOURS... MAINLY EAST OF I-55. TOMORROW...IN THE WAKE OF
EXITING SHOWERS...SOME SMALL POPS MOSTLY SOUTH OF INTERSTATE 70.
THESE POPS ARE MOSTLY A PRODUCT OF PREVIOUS MODEL SOLUTIONS WITH
THE ACTIVITY IN THE OHIO RIVER VALLEY. WILL KEEP THEM IN FOR ANY
LINGERING OVERNIGHT PRECIP...BUT MOSTLY REFLECTIVE OF EARLY IN THE
DAY.
LONG TERM...MONDAY THROUGH FRIDAY...
SCATTERED PRECIP THIS AFTERNOON WILL DO LITTLE TO ALLEVIATE THE
DROUGHT OVER THE REGION... PARTICULARLY WITH THE RIDGE BUILDING IN
THE WESTERN CONUS YET AGAIN...AND PUSHING 850MB TEMPS UP AND SFC
TEMPS BACK INTO THE MID-UPPER 90S. DRY WEATHER CONTINUES...HAVE
RAISED MAX TEMPS A DEGREE OR TWO OVER GUIDANCE SINCE MODELS KEEP
PRECIP AND CLOUD COVER IN ABSENCE OF REAL MOISTURE. BEST CHANCES FOR
PRECIP IN EXTENDED COME WITH WED NIGHT AND A PASSING TROF/SFC
BOUNDARY AS AN UPPER WAVE RIPPLES THROUGH THE 500MB FLOW ALONG THE
US/CAN BORDER. THIS FAR SOUTH...AVAILABLE MOISTURE WILL BE
QUESTIONABLE...AS WILL THE AMOUNT OF SFC CONVERGENCE. HAVE PULLED
BACK THE BLENDED POPS WHEREVER POSSIBLE. SCT SHOWER ACTIVITY IS
ALL THAT IS LIKELY IN THIS FORECAST...A VERY SMALL PERCENTAGE OF
AREA WILL SEE THE PRECIP.
HJS
&&
.AVIATION...
ISSUED 1248 PM CDT SAT JUL 14 2012
ISOLATED CONVECTION FIRING THIS AFTERNOON IN AN UNSTABLE
ATMOSPHERE. BEST T-STORM COVERAGE FOR NEXT COUPLE HOURS NEAR
KDEC/KCMI ALONG WEAK CONVERGENCE LINE AND HAVE TEMPO THUNDER HERE. BY
MID AFTERNOON AIRMASS OVER WESTERN TAF SITES WILL HAVE RECOVERED
FROM MORNING CONVECTION AND HAVE VCTS UNTIL 02Z. IN ANY STORMS
BRIEF VSBY REDUCTIONS TO 1SM AND WIND GUSTS TO 30 KTS
POSSIBLE...THOUGH CHANCES OF THIS HITTING A TAF SITE VERY LOW. THEN
FOR OVERNIGHT THROUGH 18Z SUNDAY ONLY EXPECT SCATTED MID AND HIGH
LEVEL CLOUDS AS THE MID LEVEL TROUGH RESPONSIBLE FOR UNSETTLED
WEATHER BEGINS TO SHIFT EAST. SITES THAT GET RAIN TODAY WILL LIKELY
SEE REDUCED VSBYS LATE TONIGHT IN LIGHT WIND REGIME AND CURRENTLY
HAVE REDUCED TO 3SM FOR KPIA/KCMI 09-13Z SUNDAY.
25
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
248 PM CDT SAT JUL 14 2012
.DISCUSSION...
210 PM CDT
CONCERNS WITH THE FORECAST ARE CENTERED ON CONVECTION THROUGH THIS
EVENING...AND THEN HOT TEMPERATURES THE NEXT SEVERAL DAYS.
SHORT TERM...REST OF THIS AFTERNOON THROUGH SUNDAY...
TOWERING CUMULUS ALONG WITH SOME SCATTERED STORMS HAVE DEVELOPED
EARLY THIS AFTERNOON ACROSS MAINLY THE EASTERN HALF OF THE
FORECAST AREA ALONG AND AHEAD OF A SHEARED OUT UPPER IMPULSE AND
AN ELEVATED /850-700MB/ WIND AND MOISTURE CONVERGENCE ZONE. GIVEN
A FAIRLY UNSTABLE AIR MASS PER MODIFIED AMDAR SOUNDINGS AND RAP
ANALYSIS...WITH MLCAPE VALUES OF 1000 TO 1500 J/KG...THESE STORMS
SHOULD CONTINUE TO REGENERATE WITH THE FURTHER FOCI OF BOUNDARY
INTERACTIONS. HAVE ALREADY SEEN THE DIVERGENT VELOCITY SIGNATURES
ON RADAR UNDERNEATH THESE STORMS WITHIN JUST TWO RADAR
VCPS...SHOWING THE DOWNDRAFT POTENTIAL ONCE AGAIN. ENVIRONMENTAL
DCAPE VALUES ANALYZED BY THE RAP OF 700 TO 1000 J/KG ARE SLIGHTLY
LESS THAN YESTERDAY...BUT SUFFICIENT ENOUGH FOR A POSSIBLE
ISOLATED SEVERE GUST...INCLUDING IN NEARSHORE AREAS OF THE LAKE IN
ANY STORMS THAT DRIFT NORTHEAST OVER THAT AREA.
AN UPPER LEVEL SHORT WAVE...AS PART OF THE LARGER BROAD
TROUGH...IS MOVING SOUTHEAST ACROSS WESTERN WI EARLY THIS
AFTERNOON. THE INITIAL SURFACE BOUNDARY UNDERNEATH THIS IS HELPING
TO FOCUS SOME SCATTERED STORMS...WITH SIMILAR ML INSTABILITY OF
1000 TO 1500 J/KG. MORE DEVELOPMENT IS ANTICIPATED THROUGH EARLY
EVENING IN ADVANCE OF THIS AS CONVERGENCE IMPROVES...AND SOME OF
THIS MAY POTENTIALLY BE ALONG OUTFLOW THAT IS ALREADY INTO
NORTHWEST IL. EXPLICIT CONVECTIVE MODELS DO KEY IN ON SCATTERED
STORM DEVELOPMENT TOWARD THE I-39 CORRIDOR BY LATE AFTERNOON. WITH
THE SHORT WAVE AND FRONTAL APPROACH...ALONG WITH DEEP LAYER SHEAR
VALUES OF SEMI-DECENT 30 KT PROJECTED...THESE SHOWERS AND
STORMS HAVE POTENTIAL TO HANG ON LATER INTO THE EVENING.
THE COOL FRONT WILL MOVE THROUGH THE AREA LATE TONIGHT AND SUNDAY
MORNING...BUT WASHING OUT AS IT DOES. TEMPERATURES ON SUNDAY ARE
ACTUALLY EXPECTED TO BE SLIGHTLY HIGHER THAN TODAY...AND DEW
POINTS SHOULD BE CLOSE. THIS WILL AGAIN PROVIDE MODEST
INSTABILITY...BUT HEIGHT RISES ALOFT SHOULD TEMPER STORM
DEVELOPMENT. A ROGUE LATE AFTERNOON CELL OR TWO CANNOT BE RULED
OUT ALONG WEAK SURFACE CONVERGENCE...BUT HAVE NOT MENTIONED IN THE
FORECAST AT THIS TIME. HIGHS ON SUNDAY LOOK TO TOP OUT IN THE
LOWER TO MID 90S...WITH A LAKE BREEZE PROVIDING SOME COOLING FOR
DOWNTOWN CHICAGO AND NEARBY AREAS DURING THE AFTERNOON. THESE LAKE
SHORE AREAS STILL MAY REACH 90 OR NEAR IT BEFORE THE LAKE BREEZE
PUSHES THROUGH.
MTF
LONG TERM...SUNDAY NIGHT THROUGH SATURDAY...
THE UPPER LEVEL RIDGE REESTABLISHES ITSELF ACROSS THE CENTRAL US AS
THE TROUGH MOVES OFF TOWARD THE NEW ENGLAND AREA. A WEAKENING AREA
OF LOW PRESSURE MOVES NORTH OF THE GREAT LAKES MONDAY NIGHT...WHILE
ITS COLD FRONT SINKS SOUTH DOWN THE LAKE ON TUESDAY.
PRECIP CHANCES DIMINISH AS THE TROUGH DRIFTS EASTWARD SUNDAY NIGHT.
THE BEST CHANCE OF PRECIP IN THE EXTENDED IS ALONG THE COLD FRONT
LATE TUESDAY THROUGH WEDNESDAY. GUIDANCE DIFFERS ON THE SPEED OF
THE FRONT...WITH THE GFS BRINGING THE FRONT THROUGH MUCH FASTER THAN
THE ECMWF. GIVEN ISSUES WITH THE GFS LATELY...AND THE ECMWF HAVING
VERY CONSISTENT TIMING OVER THE PAST FEW DAYS...GOING WITH THE
SLOWER SOLUTION. BOTH MODELS INDICATE MOISTURE WILL POOL ALONG THE
FRONT...BUT THEN DISSIPATE AS THE FRONT ENTERS NORTHERN IL.
THEREFORE...KEPT BEST PRECIP CHANCES NORTH OF I-80. LIMITED ACTUAL
PRECIP CHANCES TO LESS THAN 50 PERCENT GIVEN THE MODEL TRENDS AND
DRY CONDITIONS.
HIGH PRESSURE BUILDS IN BEHIND THE FRONT...AND GUIDANCE SUGGESTS
RANDOM PERIODS OF PRECIP DURING THE LATTER HALF OF NEXT WEEK.
HOWEVER...WITH NO CLEAR SOURCE OF FORCING...QUESTIONABLE MOISTURE
SOURCES...AND DROUGHT CONDITIONS...DECIDED TO KEEP THE REMAINDER OF
THE EXTENDED DRY. AT THIS POINT THE BIGGER CRIME IS GETTING FOLKS
HOPES UP FOR RAIN ONLY TO DISAPPOINT.
HEAT BUILDS ACROSS THE REGION THROUGH TUESDAY. GUIDANCE SUGGESTS
THERE WILL ONLY BE A SMALL PUSH OF SLIGHTLY COOLER AIR BEHIND THE
FRONT...WITH WEDNESDAY LOOKING TO BE A BIT COOLER. HOWEVER 850 HPA
TEMPS BEGIN TO WARM ALMOST IMMEDIATELY WITH THE UPPER LEVEL RIDGE SW
OF THE CWA. THEREFORE...THE LATTER HALF OF NEXT WEEK LOOKS ABOVE
AVERAGE.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* TSRA IN THE AREA UNTIL EARLY EVENING. MOST SIGNIFICANT IMPACT
THROUGH 21Z.
* WINDS VARIABLE THROUGH EARLY EVENING DUE TO TSRA IN THE AREA.
BECOMING LIGHT SOUTHWESTERLY LATER IN THE EVENING.
PAW
//DISCUSSION...UPDATED 18Z...
PRIMARY FORECAST CONCERN CONTINUES TO BE SHRA/TSRA REDEVELOPMENT.
MORNING TSRA SERVED TO STABILIZE THE ATMOSPHERE TEMPORARILY. SO
FAR THINGS HAVE BEEN SLOW TO RECOVER. THE TSRA ACTIVITY IN EAST
CENTRAL ILLINOIS INTO CENTRAL INDIANA IS ALSO HELPING TO SLOW
REDEVELOPMENT OVER NORTHERN ILLINOIS. AN UPPER LEVEL TROUGH IS
STILL OVER THE AREA PROVIDING SUPPORT FOR TSRA AND MODELS CONTINUE
TO INDICATE REDEVELOPMENT. HAVE OPTED TO LEAVE TSRA MENTION IN THE
TAFS FOR NOW...BUT HAVE ADJUSTED THE TIMING TO LATER...WHICH
SHORTENS THE TIME FRAME...AND WILL MONITOR THE SITUATION CLOSELY
FOR FURTHER UPDATES.
WINDS WILL BE LIGHT AND SOMEWHAT VARIABLE. BY MID TO LATE
AFTERNOON A SOUTHWESTERLY DIRECTION SHOULD BE FAVORED. THE
QUESTION IS THE WHETHER THE LAKE BREEZE WILL MAKE IT AS FAR INLAND
AS ORD OR MDW.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE IN TSRA TREND.
* MEDIUM CONFIDENCE IN WIND TREND.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT THROUGH TUESDAY...VFR.
TUESDAY NIGHT AND WEDNESDAY...CHANCE OF TSRA...OTHERWISE VFR.
THURSDAY AND FRIDAY...VFR.
MDB
&&
.MARINE...
145 PM CDT
LOW PRESSURE ACROSS LAKE SUPERIOR WILL CONTINUE TO MOVE EAST
THROUGH SUNDAY. THIS WILL STEER A COOL FRONT ACROSS THE LAKE LATE
TONIGHT. AHEAD OF THIS WILL BE SOME SCATTERED STORMS...SOME OF
WHICH ARE LIKELY TO BE GUSTY BASED ON THE ENVIRONMENT. THESE WILL
BE MOST FAVORED ACROSS THE SOUTHERN THIRD OF THE LAKE INCLUDING
NEAR SHORE AREAS OF IL...IN...AND SOUTHWEST MI. WINDS BEHIND THE
FRONT ON SUNDAY WILL BECOME LIGHT AND BEGIN TURNING BACK TO
SOUTHERLY ALREADY BY AFTERNOON. SOUTHWEST WINDS WILL INCREASE ON
MON...WITH OPEN WATER LOCATIONS ACROSS THE NORTH LIKELY REACHING
30 KT DURING MON NIGHT. A COOL FRONT WILL SLOWLY WORK SOUTH
ACROSS THE LAKE ON TUESDAY AND TUESDAY NIGHT. THIS WILL SHIFT
WINDS TO THE NORTH AND PROVIDE A FOCUS FOR SCATTERED THUNDERSTORMS
ONCE AGAIN.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
211 PM CDT SAT JUL 14 2012
.DISCUSSION...
210 PM CDT
CONCERNS WITH THE FORECAST ARE CENTERED ON CONVECTION THROUGH THIS
EVENING...AND THEN HOT TEMPERATURES THE NEXT SEVERAL DAYS.
SHORT TERM...REST OF THIS AFTERNOON THROUGH SUNDAY...
TOWERING CUMULUS ALONG WITH SOME SCATTERED STORMS HAVE DEVELOPED
EARLY THIS AFTERNOON ACROSS MAINLY THE EASTERN HALF OF THE
FORECAST AREA ALONG AND AHEAD OF A SHEARED OUT UPPER IMPULSE AND
AN ELEVATED /850-700MB/ WIND AND MOISTURE CONVERGENCE ZONE. GIVEN
A FAIRLY UNSTABLE AIR MASS PER MODIFIED AMDAR SOUNDINGS AND RAP
ANALYSIS...WITH MLCAPE VALUES OF 1000 TO 1500 J/KG...THESE STORMS
SHOULD CONTINUE TO REGENERATE WITH THE FURTHER FOCI OF BOUNDARY
INTERACTIONS. HAVE ALREADY SEEN THE DIVERGENT VELOCITY SIGNATURES
ON RADAR UNDERNEATH THESE STORMS WITHIN JUST TWO RADAR
VCPS...SHOWING THE DOWNDRAFT POTENTIAL ONCE AGAIN. ENVIRONMENTAL
DCAPE VALUES ANALYZED BY THE RAP OF 700 TO 1000 J/KG ARE SLIGHTLY
LESS THAN YESTERDAY...BUT SUFFICIENT ENOUGH FOR A POSSIBLE
ISOLATED SEVERE GUST...INCLUDING IN NEARSHORE AREAS OF THE LAKE IN
ANY STORMS THAT DRIFT NORTHEAST OVER THAT AREA.
AN UPPER LEVEL SHORT WAVE...AS PART OF THE LARGER BROAD
TROUGH...IS MOVING SOUTHEAST ACROSS WESTERN WI EARLY THIS
AFTERNOON. THE INITIAL SURFACE BOUNDARY UNDERNEATH THIS IS HELPING
TO FOCUS SOME SCATTERED STORMS...WITH SIMILAR ML INSTABILITY OF
1000 TO 1500 J/KG. MORE DEVELOPMENT IS ANTICIPATED THROUGH EARLY
EVENING IN ADVANCE OF THIS AS CONVERGENCE IMPROVES...AND SOME OF
THIS MAY POTENTIALLY BE ALONG OUTFLOW THAT IS ALREADY INTO
NORTHWEST IL. EXPLICIT CONVECTIVE MODELS DO KEY IN ON SCATTERED
STORM DEVELOPMENT TOWARD THE I-39 CORRIDOR BY LATE AFTERNOON. WITH
THE SHORT WAVE AND FRONTAL APPROACH...ALONG WITH DEEP LAYER SHEAR
VALUES OF SEMI-DECENT 30 KT PROJECTED...THESE SHOWERS AND
STORMS HAVE POTENTIAL TO HANG ON LATER INTO THE EVENING.
THE COOL FRONT WILL MOVE THROUGH THE AREA LATE TONIGHT AND SUNDAY
MORNING...BUT WASHING OUT AS IT DOES. TEMPERATURES ON SUNDAY ARE
ACTUALLY EXPECTED TO BE SLIGHTLY HIGHER THAN TODAY...AND DEW
POINTS SHOULD BE CLOSE. THIS WILL AGAIN PROVIDE MODEST
INSTABILITY...BUT HEIGHT RISES ALOFT SHOULD TEMPER STORM
DEVELOPMENT. A ROGUE LATE AFTERNOON CELL OR TWO CANNOT BE RULED
OUT ALONG WEAK SURFACE CONVERGENCE...BUT HAVE NOT MENTIONED IN THE
FORECAST AT THIS TIME. HIGHS ON SUNDAY LOOK TO TOP OUT IN THE
LOWER TO MID 90S...WITH A LAKE BREEZE PROVIDING SOME COOLING FOR
DOWNTOWN CHICAGO AND NEARBY AREAS DURING THE AFTERNOON. THESE LAKE
SHORE AREAS STILL MAY REACH 90 OR NEAR IT BEFORE THE LAKE BREEZE
PUSHES THROUGH.
MTF
LONG TERM...SUNDAY NIGHT THROUGH SATURDAY...
THE UPPER LEVEL RIDGE REESTABLISHES ITSELF ACROSS THE CENTRAL US AS
THE TROUGH MOVES OFF TOWARD THE NEW ENGLAND AREA. A WEAKENING AREA
OF LOW PRESSURE MOVES NORTH OF THE GREAT LAKES MONDAY NIGHT...WHILE
ITS COLD FRONT SINKS SOUTH DOWN THE LAKE ON TUESDAY.
PRECIP CHANCES DIMINISH AS THE TROUGH DRIFTS EASTWARD SUNDAY NIGHT.
THE BEST CHANCE OF PRECIP IN THE EXTENDED IS ALONG THE COLD FRONT
LATE TUESDAY THROUGH WEDNESDAY. GUIDANCE DIFFERS ON THE SPEED OF
THE FRONT...WITH THE GFS BRINGING THE FRONT THROUGH MUCH FASTER THAN
THE ECMWF. GIVEN ISSUES WITH THE GFS LATELY...AND THE ECMWF HAVING
VERY CONSISTENT TIMING OVER THE PAST FEW DAYS...GOING WITH THE
SLOWER SOLUTION. BOTH MODELS INDICATE MOISTURE WILL POOL ALONG THE
FRONT...BUT THEN DISSIPATE AS THE FRONT ENTERS NORTHERN IL.
THEREFORE...KEPT BEST PRECIP CHANCES NORTH OF I-80. LIMITED ACTUAL
PRECIP CHANCES TO LESS THAN 50 PERCENT GIVEN THE MODEL TRENDS AND
DRY CONDITIONS.
HIGH PRESSURE BUILDS IN BEHIND THE FRONT...AND GUIDANCE SUGGESTS
RANDOM PERIODS OF PRECIP DURING THE LATTER HALF OF NEXT WEEK.
HOWEVER...WITH NO CLEAR SOURCE OF FORCING...QUESTIONABLE MOISTURE
SOURCES...AND DROUGHT CONDITIONS...DECIDED TO KEEP THE REMAINDER OF
THE EXTENDED DRY. AT THIS POINT THE BIGGER CRIME IS GETTING FOLKS
HOPES UP FOR RAIN ONLY TO DISAPPOINT.
HEAT BUILDS ACROSS THE REGION THROUGH TUESDAY. GUIDANCE SUGGESTS
THERE WILL ONLY BE A SMALL PUSH OF SLIGHTLY COOLER AIR BEHIND THE
FRONT...WITH WEDNESDAY LOOKING TO BE A BIT COOLER. HOWEVER 850 HPA
TEMPS BEGIN TO WARM ALMOST IMMEDIATELY WITH THE UPPER LEVEL RIDGE SW
OF THE CWA. THEREFORE...THE LATTER HALF OF NEXT WEEK LOOKS ABOVE
AVERAGE.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* POTENTIAL FOR SHRA/TSRA DEVELOPMENT THIS AFTERNOON.
* LIGHT VARIABLE WINDS BECOMING SOUTHWESTERLY BY MID AFTERNOON.
* POTENTIAL FOR LAKE BREEZE BOUNDARY TO CROSS THE TERMINALS AND
SHIFT WINDS TO EAST-SOUTHWEST DURING THE AFTERNOON.
PAW
//DISCUSSION...UPDATED 18Z...
PRIMARY FORECAST CONCERN CONTINUES TO BE SHRA/TSRA REDEVELOPMENT.
MORNING TSRA SERVED TO STABILIZE THE ATMOSPHERE TEMPORARILY. SO
FAR THINGS HAVE BEEN SLOW TO RECOVER. THE TSRA ACTIVITY IN EAST
CENTRAL ILLINOIS INTO CENTRAL INDIANA IS ALSO HELPING TO SLOW
REDEVELOPMENT OVER NORTHERN ILLINOIS. AN UPPER LEVEL TROUGH IS
STILL OVER THE AREA PROVIDING SUPPORT FOR TSRA AND MODELS CONTINUE
TO INDICATE REDEVELOPMENT. HAVE OPTED TO LEAVE TSRA MENTION IN THE
TAFS FOR NOW...BUT HAVE ADJUSTED THE TIMING TO LATER...WHICH
SHORTENS THE TIME FRAME...AND WILL MONITOR THE SITUATION CLOSELY
FOR FURTHER UPDATES.
WINDS WILL BE LIGHT AND SOMEWHAT VARIABLE. BY MID TO LATE
AFTERNOON A SOUTHWESTERLY DIRECTION SHOULD BE FAVORED. THE
QUESTION IS THE WHETHER THE LAKE BREEZE WILL MAKE IT AS FAR INLAND
AS ORD OR MDW.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE THAT SHRA/TSRA WILL DEVELOP THIS AFTERNOON.
* MEDIUM CONFIDENCE IN PREVAILING WIND DIRECTION. MEDIUM
CONFIDENCE IN LAKE BREEZE DEVELOPING...LOW CONFIDENCE IN WHETHER
IT WILL MOVE INLAND FAR ENOUGH TO REACH THE TERMINALS.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT THROUGH TUESDAY...VFR.
TUESDAY NIGHT AND WEDNESDAY...CHANCE OF TSRA...OTHERWISE VFR.
THURSDAY AND FRIDAY...VFR.
MDB
&&
.MARINE...
145 PM CDT
LOW PRESSURE ACROSS LAKE SUPERIOR WILL CONTINUE TO MOVE EAST
THROUGH SUNDAY. THIS WILL STEER A COOL FRONT ACROSS THE LAKE LATE
TONIGHT. AHEAD OF THIS WILL BE SOME SCATTERED STORMS...SOME OF
WHICH ARE LIKELY TO BE GUSTY BASED ON THE ENVIRONMENT. THESE WILL
BE MOST FAVORED ACROSS THE SOUTHERN THIRD OF THE LAKE INCLUDING
NEAR SHORE AREAS OF IL...IN...AND SOUTHWEST MI. WINDS BEHIND THE
FRONT ON SUNDAY WILL BECOME LIGHT AND BEGIN TURNING BACK TO
SOUTHERLY ALREADY BY AFTERNOON. SOUTHWEST WINDS WILL INCREASE ON
MON...WITH OPEN WATER LOCATIONS ACROSS THE NORTH LIKELY REACHING
30 KT DURING MON NIGHT. A COOL FRONT WILL SLOWLY WORK SOUTH
ACROSS THE LAKE ON TUESDAY AND TUESDAY NIGHT. THIS WILL SHIFT
WINDS TO THE NORTH AND PROVIDE A FOCUS FOR SCATTERED THUNDERSTORMS
ONCE AGAIN.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1245 PM CDT SAT JUL 14 2012
.DISCUSSION...
1100 AM CDT
GOING GENERAL FORECAST IDEA OF SCATTERED THUNDERSTORMS DEVELOPING
THIS AFTERNOON REMAINS SUPPORTED BY LATEST TRENDS. ALL IN ALL JUST
MINOR TWEAKS MADE MAINLY BASED ON THERMAL INFLUENCE OF EARLY
MORNING CONVECTION.
FAIRLY AMPLIFIED UPPER TROUGH FOR SUMMERTIME SEEN ON THE WATER
VAPOR SATELLITE LATE THIS MORNING REMAINS LITTERED WITH EMBEDDED
VORTICITY MAXIMA. ONE SUCH IMPULSE LIFTING NORTHEAST FROM CENTRAL
IL EARLY THIS MORNING HAS BECOME SHEARED OUT AND THE ASSOCIATED
SHOWERS AND EMBEDDED CONVECTION WEAKENED RATHER QUICKLY AS A
RESULT. THE 850-700MB CONVERGENT ZONE/TROUGH MENTIONED IN PREV
DISCUSSION IS STILL IN PLACE ACROSS THE CENTRAL FORECAST AREA IN
THE WAKE OF THESE SHOWERS. OUTFLOW FROM THE DECAYED CONVECTION SEEN
ON VISIBLE SATELLITE AND RADAR HAS PUSHED EAST AND IS LOCATED
FROM PORTER COUNTY INDIANA SOUTHWEST TOWARD CHAMPAIGN-URBANA.
CELLS HAVE STARTED TO DEVELOP ON AND AHEAD OF THE SOUTHERN PORTION
OF THIS BOUNDARY WHERE THE CAP LOOKS TO HAVE ERODED. THE LOW-LEVEL
COLD POOL BEHIND THE OUTFLOW BOUNDARY ACROSS MUCH OF THE EASTERN
HALF OF THE FORECAST AREA IS SHALLOW PER PROFILER WIND FIELD...AND
1000 TO 1500 J/KG OF MUCAPE EXISTS ABOVE THIS LAYER PER ILX
SOUNDING AND RAP ANALYSIS. SO SCATTERED REDEVELOPMENT FROM WHERE
EARLIER CONVECTION DECAYED/ALONG THE 850-700MB CONVERGENT AXIS AND
EASTWARD REMAINS FAVORED THIS AFTERNOON. A LAKE BREEZE COMPONENT
SHOULD ONLY AID THIS. DOWNDRAFT CAPE VALUES OF 700-1000 J/KG ON
RAP ANALYSIS WOULD FAVOR SOME STRONGER DOWNDRAFTS WITHIN STORMS.
BACK TO THE WEST...CONVECTION AHEAD OF THE SURFACE BOUNDARY ACROSS
NORTHEAST IA CONTINUES TO TRACK SOUTHEAST AIDED BY A BETTER
DEFINED SHORT WAVE ACROSS WESTERN WI MOVING SOUTHEAST. INHIBITION
IMMEDIATELY AHEAD OF THIS APPEARS TO BE VERY MINIMAL IF ANY PER
MODIFIED 12Z DVN SOUNDING. SO EXPECT THIS AREA TO CONTINUE TO
MIGRATE SOUTHEAST WITH SOME ADDITIONAL DEVELOPMENT AHEAD AS AREAS
OF NORTHWEST/NORTH CENTRAL IL DESTABILIZE. THIS WOULD FAVOR THE
WESTERN FORECAST AREA FOR SOME SCATTERED CONVECTION...ESPECIALLY
IN THE MID TO LATE AFTERNOON AND POTENTIALLY EARLY EVENING.
HAVE LOWERED TEMPERATURES SOME NEAR PONTIAC AND STREATOR WHERE
MID CLOUD LOOKS TO BE MOST PERSISTENT AND RESIDUAL COLD POOL WILL
KEEP TEMPERATURES SLOWER TO WARM. MUCH OF THE CHICAGO AREA LOOKS
TO REACH NEAR 90 WITH ONLY LIMITED LAKE INFLUENCE DUE TO 5-10 MPH
OFFSHORE COMPONENT AT PRESENT.
MTF
//PREV DISCUSSION...
331 AM CDT
PRIMARY FORECAST CHALLENGES THIS MORNING ARE PRECIP/CONVECTIVE
TRENDS TODAY FOLLOWED BY A SHORTER AND LESS INTENSE BOUT OF HEAT
THAN WHAT WE SAW LAST WEEK.
UPPER TROUGH OVER THE MIDDLE AND UPPER MISSISSIPPI VALLEY IS SLOWING
MOVING EAST THIS MORNING WITH WATER VAPOR IMAGERY SHOWING SEVERAL
SMALLER VORTICITY MAXIMA EMBEDDED WITHIN THIS TROUGH. THE RATHER
WEAK AND SOMEWHAT ILL DEFINED FORCING IS RESULTING IN FAIRLY LOW
CONFIDENCE IN PRECIP TRENDS THE NEXT 24 HOURS. SOME STORMS ARE
FIRING UP NOW IN VICINITY OF 850MB TROUGH/CONVERGENCE AXIS. LATEST
RAP GUIDANCE SUGGESTS THAT THIS CONVERGENCE WILL WEAKEN THIS MORNING
WHICH IF IT VERIFIES WOULD ALSO LIKELY SPELL THE SLOW DEMISE OR AT
LEAST WEAKENING OF THIS CURRENT CONVECTION.
FAIRLY EXPANSIVE AREA OF WHAT APPEARS TO BE ALTO STRATUS OVER WESTERN
IL/EASTERN MO IS SLOWLY PROGRESSING EASTWARD AND WILL LIKELY RETARD
HEATING TODAY LIMITING INSTABILITY. WHERE MIXED SUNSHINE DOES OCCUR
EXPECT SUFFICIENT SURFACE BASED INSTABILITY TO DEVELOP TO SUPPORT
RENEWED SCATTERED THUNDERSTORM DEVELOPMENT THIS AFTERNOON...WHICH
SEEMS LIKE IT MAY TEND TO FAVOR OUR EASTERN CWA AND POTENTIALLY
ALONG LAKE BREEZE AGAIN THIS AFTERNOON. CONVECTION LIKELY TO
GRADUALLY WANE AND SHIFT EASTWARD OUT OF THE AREA TONIGHT AS TROUGH
MIGRATES EASTWARD.
UPPER RIDGE THEN BEGINS TO BUILD INTO THE AREA WHICH SHOULD RESULT
IN DRIER AND HOT CONDITIONS SUNDAY THROUGH TUESDAY. BY MONDAY AND
TUESDAY MID TO UPPER 90S LOOK LIKE A GOOD BET WITH EVEN A CHANCE OF
ISOLATED SPOTS NEARING THE CENTURY MARK. WEAK COLD FRONT LIKELY TO
SLOWLY SAG SOUTHWARD ACROSS THE AREA TUESDAY NIGHT INTO WEDNESDAY
BRINGING SOMEWHAT COOLER CONDITIONS...ESPECIALLY NEAR THE LAKE...AS
WELL AS AN INCREASED THREAT OF AT LEAST SOME SHOWERS AND
THUNDERSTORMS. DRIER CONDITIONS ARE THEN EXPECTED TOWARD THE END OF
THE WEEK AS FRONT SETTLES SOUTH OF THE AREA. NO STRONG PUSH OF
COOLER AIR BEHIND THE FRONT SO WOULD EXPECT TEMPS TO REMAIN SLIGHTLY
ABOVE AVERAGE.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* POTENTIAL FOR SHRA/TSRA DEVELOPMENT THIS AFTERNOON.
* LIGHT VARIABLE WINDS BECOMING SOUTHWESTERLY BY MID AFTERNOON.
* POTENTIAL FOR LAKE BREEZE BOUNDARY TO CROSS THE TERMINALS AND
SHIFT WINDS TO EAST-SOUTHWEST DURING THE AFTERNOON.
PAW
//DISCUSSION...UPDATED 18Z...
PRIMARY FORECAST CONCERN CONTINUES TO BE SHRA/TSRA REDEVELOPMENT.
MORNING TSRA SERVED TO STABILIZE THE ATMOSPHERE TEMPORARILY. SO
FAR THINGS HAVE BEEN SLOW TO RECOVER. THE TSRA ACTIVITY IN EAST
CENTRAL ILLINOIS INTO CENTRAL INDIANA IS ALSO HELPING TO SLOW
REDEVELOPMENT OVER NORTHERN ILLINOIS. AN UPPER LEVEL TROUGH IS
STILL OVER THE AREA PROVIDING SUPPORT FOR TSRA AND MODELS CONTINUE
TO INDICATE REDEVELOPMENT. HAVE OPTED TO LEAVE TSRA MENTION IN THE
TAFS FOR NOW...BUT HAVE ADJUSTED THE TIMING TO LATER...WHICH
SHORTENS THE TIME FRAME...AND WILL MONITOR THE SITUATION CLOSELY
FOR FURTHER UPDATES.
WINDS WILL BE LIGHT AND SOMEWHAT VARIABLE. BY MID TO LATE
AFTERNOON A SOUTHWESTERLY DIRECTION SHOULD BE FAVORED. THE
QUESTION IS THE WHETHER THE LAKE BREEZE WILL MAKE IT AS FAR INLAND
AS ORD OR MDW.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE THAT SHRA/TSRA WILL DEVELOP THIS AFTERNOON.
* MEDIUM CONFIDENCE IN PREVAILING WIND DIRECTION. MEDIUM
CONFIDENCE IN LAKE BREEZE DEVELOPING...LOW CONFIDENCE IN WHETHER
IT WILL MOVE INLAND FAR ENOUGH TO REACH THE TERMINALS.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT THROUGH TUESDAY...VFR.
TUESDAY NIGHT AND WEDNESDAY...CHANCE OF TSRA...OTHERWISE VFR.
THURSDAY AND FRIDAY...VFR.
MDB
&&
.MARINE...
303 AM CDT
HIGH PRESSURE REMAINS SPRAWLED ACROSS THE EASTERN U.S. WITH LOW
PRESSURE OVER WESTERN HUDSON BAY EXTENDING INTO THE EASTERN
DAKOTAS/WESTERN MINNESOTA. SOUTHERLY WINDS WILL CONTINUE ACROSS LAKE
MICHIGAN TODAY WITH THE EXCEPTION OF WINDS TURNING ONSHORE OVER THE
FAR SOUTHERN PART OF THE LAKE. THE STRONGEST WINDS WILL BE ACROSS
THE NORTHERN PART OF THE LAKE TODAY AS THE PRESSURE GRADIENT
TIGHTENS AHEAD OF THE APPROACHING LOW. THE LOW WILL CROSS THE LAKE
TONIGHT TURNING WINDS MORE WESTERLY AND NORTHWESTERLY INTO SUNDAY
MORNING BUT A SHIFT TO THE SOUTHWEST IS EXPECTED BY SUNDAY AFTERNOON
AS HIGH PRESSURE RETURNS. ANOTHER SURFACE LOW WILL MOVE FROM THE
DAKOTAS TO LAKE SUPERIOR MONDAY AND MONDAY NIGHT. THE PRESSURE
GRADIENT WILL TIGHTEN UP AHEAD OF THIS LOW MONDAY NIGHT AND LATEST
INDICATIONS ARE THAT GUSTS COULD PUSH 30 KT ACROSS THE NORTHERN
THIRD OR SO OF THE LAKE MONDAY EVENING. WINDS WILL THEN TURN NORTH
AND NORTHEAST AS THE LOW PASSES AND A COOL FRONT PUSHES SOUTHWARD
LATE TUESDAY OR EARLY WEDNESDAY. WINDS SHOULD REMAIN ELEVATED BEHIND
THE LOW WITH SPEEDS GENERALLY IN THE 15 TO 20 KT RANGE INTO
WEDNESDAY NIGHT. HIGH PRESSURE WILL THEN REMAIN ACROSS THE LAKE INTO
THE END OF THE WEEK KEEPING LIGHTER WINDS IN PLACE.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1107 AM CDT SAT JUL 14 2012
.DISCUSSION...
1100 AM CDT
GOING GENERAL FORECAST IDEA OF SCATTERED THUNDERSTORMS DEVELOPING
THIS AFTERNOON REMAINS SUPPORTED BY LATEST TRENDS. ALL IN ALL JUST
MINOR TWEAKS MADE MAINLY BASED ON THERMAL INFLUENCE OF EARLY
MORNING CONVECTION.
FAIRLY AMPLIFIED UPPER TROUGH FOR SUMMERTIME SEEN ON THE WATER
VAPOR SATELLITE LATE THIS MORNING REMAINS LITTERED WITH EMBEDDED
VORTICITY MAXIMA. ONE SUCH IMPULSE LIFTING NORTHEAST FROM CENTRAL
IL EARLY THIS MORNING HAS BECOME SHEARED OUT AND THE ASSOCIATED
SHOWERS AND EMBEDDED CONVECTION WEAKENED RATHER QUICKLY AS A
RESULT. THE 850-700MB CONVERGENT ZONE/TROUGH MENTIONED IN PREV
DISCUSSION IS STILL IN PLACE ACROSS THE CENTRAL FORECAST AREA IN
THE WAKE OF THESE SHOWERS. OUTFLOW FROM THE DECAYED CONVECTION SEEN
ON VISIBLE SATELLITE AND RADAR HAS PUSHED EAST AND IS LOCATED
FROM PORTER COUNTY INDIANA SOUTHWEST TOWARD CHAMPAIGN-URBANA.
CELLS HAVE STARTED TO DEVELOP ON AND AHEAD OF THE SOUTHERN PORTION
OF THIS BOUNDARY WHERE THE CAP LOOKS TO HAVE ERODED. THE LOW-LEVEL
COLD POOL BEHIND THE OUTFLOW BOUNDARY ACROSS MUCH OF THE EASTERN
HALF OF THE FORECAST AREA IS SHALLOW PER PROFILER WIND FIELD...AND
1000 TO 1500 J/KG OF MUCAPE EXISTS ABOVE THIS LAYER PER ILX
SOUNDING AND RAP ANALYSIS. SO SCATTERED REDEVELOPMENT FROM WHERE
EARLIER CONVECTION DECAYED/ALONG THE 850-700MB CONVERGENT AXIS AND
EASTWARD REMAINS FAVORED THIS AFTERNOON. A LAKE BREEZE COMPONENT
SHOULD ONLY AID THIS. DOWNDRAFT CAPE VALUES OF 700-1000 J/KG ON
RAP ANALYSIS WOULD FAVOR SOME STRONGER DOWNDRAFTS WITHIN STORMS.
BACK TO THE WEST...CONVECTION AHEAD OF THE SURFACE BOUNDARY ACROSS
NORTHEAST IA CONTINUES TO TRACK SOUTHEAST AIDED BY A BETTER
DEFINED SHORT WAVE ACROSS WESTERN WI MOVING SOUTHEAST. INHIBITION
IMMEDIATELY AHEAD OF THIS APPEARS TO BE VERY MINIMAL IF ANY PER
MODIFIED 12Z DVN SOUNDING. SO EXPECT THIS AREA TO CONTINUE TO
MIGRATE SOUTHEAST WITH SOME ADDITIONAL DEVELOPMENT AHEAD AS AREAS
OF NORTHWEST/NORTH CENTRAL IL DESTABILIZE. THIS WOULD FAVOR THE
WESTERN FORECAST AREA FOR SOME SCATTERED CONVECTION...ESPECIALLY
IN THE MID TO LATE AFTERNOON AND POTENTIALLY EARLY EVENING.
HAVE LOWERED TEMPERATURES SOME NEAR PONTIAC AND STREATOR WHERE
MID CLOUD LOOKS TO BE MOST PERSISTENT AND RESIDUAL COLD POOL WILL
KEEP TEMPERATURES SLOWER TO WARM. MUCH OF THE CHICAGO AREA LOOKS
TO REACH NEAR 90 WITH ONLY LIMITED LAKE INFLUENCE DUE TO 5-10 MPH
OFFSHORE COMPONENT AT PRESENT.
MTF
//PREV DISCUSSION...
331 AM CDT
PRIMARY FORECAST CHALLENGES THIS MORNING ARE PRECIP/CONVECTIVE
TRENDS TODAY FOLLOWED BY A SHORTER AND LESS INTENSE BOUT OF HEAT
THAN WHAT WE SAW LAST WEEK.
UPPER TROUGH OVER THE MIDDLE AND UPPER MISSISSIPPI VALLEY IS SLOWING
MOVING EAST THIS MORNING WITH WATER VAPOR IMAGERY SHOWING SEVERAL
SMALLER VORTICITY MAXIMA EMBEDDED WITHIN THIS TROUGH. THE RATHER
WEAK AND SOMEWHAT ILL DEFINED FORCING IS RESULTING IN FAIRLY LOW
CONFIDENCE IN PRECIP TRENDS THE NEXT 24 HOURS. SOME STORMS ARE
FIRING UP NOW IN VICINITY OF 850MB TROUGH/CONVERGENCE AXIS. LATEST
RAP GUIDANCE SUGGESTS THAT THIS CONVERGENCE WILL WEAKEN THIS MORNING
WHICH IF IT VERIFIES WOULD ALSO LIKELY SPELL THE SLOW DEMISE OR AT
LEAST WEAKENING OF THIS CURRENT CONVECTION.
FAIRLY EXPANSIVE AREA OF WHAT APPEARS TO BE ALTO STRATUS OVER WESTERN
IL/EASTERN MO IS SLOWLY PROGRESSING EASTWARD AND WILL LIKELY RETARD
HEATING TODAY LIMITING INSTABILITY. WHERE MIXED SUNSHINE DOES OCCUR
EXPECT SUFFICIENT SURFACE BASED INSTABILITY TO DEVELOP TO SUPPORT
RENEWED SCATTERED THUNDERSTORM DEVELOPMENT THIS AFTERNOON...WHICH
SEEMS LIKE IT MAY TEND TO FAVOR OUR EASTERN CWA AND POTENTIALLY
ALONG LAKE BREEZE AGAIN THIS AFTERNOON. CONVECTION LIKELY TO
GRADUALLY WANE AND SHIFT EASTWARD OUT OF THE AREA TONIGHT AS TROUGH
MIGRATES EASTWARD.
UPPER RIDGE THEN BEGINS TO BUILD INTO THE AREA WHICH SHOULD RESULT
IN DRIER AND HOT CONDITIONS SUNDAY THROUGH TUESDAY. BY MONDAY AND
TUESDAY MID TO UPPER 90S LOOK LIKE A GOOD BET WITH EVEN A CHANCE OF
ISOLATED SPOTS NEARING THE CENTURY MARK. WEAK COLD FRONT LIKELY TO
SLOWLY SAG SOUTHWARD ACROSS THE AREA TUESDAY NIGHT INTO WEDNESDAY
BRINGING SOMEWHAT COOLER CONDITIONS...ESPECIALLY NEAR THE LAKE...AS
WELL AS AN INCREASED THREAT OF AT LEAST SOME SHOWERS AND
THUNDERSTORMS. DRIER CONDITIONS ARE THEN EXPECTED TOWARD THE END OF
THE WEEK AS FRONT SETTLES SOUTH OF THE AREA. NO STRONG PUSH OF
COOLER AIR BEHIND THE FRONT SO WOULD EXPECT TEMPS TO REMAIN SLIGHTLY
ABOVE AVERAGE.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* SHRA/TSRA REDEVELOPING IN THE AREA EARLY THIS AFTERNOON.
* LIGHT VARIABLE WINDS BECOMING SOUTHWESTERLY BY EARLY AFTERNOON.
* POTENTIAL FOR LAKE BREEZE BOUNDARY TO CROSS THE TERMINALS AND
SHIFT WINDS TO EAST-SOUTHEAST THIS AFTERNOON.
PAW
//DISCUSSION...UPDATED 12Z...
FORECAST CONCERN CONTINUES TO BE SHRA/TSRA THROUGH THE DAY. AN
UPPER TROUGH AND ASSOCIATED IMPULSES SLOWLY MOVING ACROSS THE
REGION WILL CONTINUE TO SUPPORT ON AND OFF TSRA DEVELOPMENT
THROUGH THE DAY. CURRENT ACTIVITY FOCUSED FROM JUST NORTH OF ORD
BACK TO VYS TO PIA WILL CONTINUE TO MOVE SLOWLY EAST-NORTHEASTWARD
THIS MORNING BUT MAY START TO FADE IN INTENSITY AND COVERAGE AS IT
APPROACHES THE CHI AREA TERMINALS IN THE NEXT 1-2 HRS. AS
INSTABILITY BUILDS INTO THE AFTERNOON THE UPPER FORCING WILL
CONTINUE RESULTING IN ISOLD-SCT TSRA DEVELOPMENT WHICH WOULD
LIKELY BE FOCUSED ACROSS NORTHEAST IL AND NORTHWEST INDIANA. IN
ADDITION TO THE UPPER TROUGH...A LAKE BREEZE MAY BE ABLE TO FORM
AND WORK INLAND OFFERING AN ADDITIONAL FOCUS FOR TSRA.
HOWEVER...THE LAKE BREEZE MAY NOT DEVELOP GIVEN POTENTIAL CLOUD
COVER AND OUTFLOW FROM CURRENT ACTIVITY. IF THE CURRENT ACTIVITY
CAN DIMINISH THEN THERE MAY BE A SEVERAL HOUR BREAK IN ACTIVITY
DURING THE MID/LATE MORNING BEFORE THE NEXT ROUND OF FORCING
MECHANISMS DRAWS NEARER AND INSTABILITY BUILDS. GIVEN THE GOOD
POTENTIAL FOR TSRA OCCURRENCE THROUGH AT LEAST LATE AFTERNOON BUT
THE UNCERTAINTY IN COVERAGE AND HOW DIRECTLY THE TERMINALS WILL BE
AFFECTED...WILL INCLUDE AN EXTENDED PERIOD OF VCTS IN THE TAF AND
ADD DETAIL WITH PREVAILING/TEMPO TSRA AS THINGS BECOME MORE CLEAR
IN THE NEAR TERM. IT IS POSSIBLE THAT SHRA/TSRA ACTIVITY FESTERS
ACROSS THE AREA THROUGH MOST OF THE DAY.
WINDS WILL BE GENERALLY LIGHT AND VARIABLE THROUGH THE MORNING BUT
OUTFLOW FROM THE EARLIER STORMS HAS TURNED THEM NORTHWESTERLY
ACROSS MUCH OF THE CHI METRO AREA. THIS WILL LIKELY BE SHORT LIVED
WITH WINDS TURNING VARIABLE BEFORE TOO LONG. EXPECT A LIGHT
SOUTHWEST DIRECTION TO TAKE OVER LATE THIS MORNING OR EARLY THIS
AFTERNOON. OUTFLOW FROM ANY STORMS THAT DO CROSS THE AREA WILL
LIKELY RESULT IN ERRATIC WIND DIRECTION AND SPEEDS WITH FAIRLY
STRONG GUSTS POSSIBLE FROM THE STRONGEST STORMS.
SHRA/TSRA POTENTIAL CONTINUES THIS EVENING BUT HAVE LITTLE
CONFIDENCE IN HOW HIGH THE POTENTIAL IS. WILL LEAVE ANY MENTION OF
SHRA/TSRA OUT OF THE TAFS FOR THE EVENING UNTIL CONFIDENCE GROWS
AND PRECIP POTENTIAL INCREASES.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM CONFIDENCE THAT SHRA/TSRA WILL REDEVELOP BY EARLY
AFTERNOON.
* MEDIUM CONFIDENCE IN PREVAILING WIND DIRECTION. MEDIUM
CONFIDENCE THAT A LAKE BREEZE WILL DEVELOP. LOW CONFIDENCE IN
WHETHER IT MOVES INLAND FAR ENOUGH TO REACH THE TERMINALS.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT THROUGH TUESDAY...VFR.
TUESDAY NIGHT AND WEDNESDAY...CHANCE OF TSRA...OTHERWISE VFR.
THURSDAY AND FRIDAY...VFR.
MDB
&&
.MARINE...
303 AM CDT
HIGH PRESSURE REMAINS SPRAWLED ACROSS THE EASTERN U.S. WITH LOW
PRESSURE OVER WESTERN HUDSON BAY EXTENDING INTO THE EASTERN
DAKOTAS/WESTERN MINNESOTA. SOUTHERLY WINDS WILL CONTINUE ACROSS LAKE
MICHIGAN TODAY WITH THE EXCEPTION OF WINDS TURNING ONSHORE OVER THE
FAR SOUTHERN PART OF THE LAKE. THE STRONGEST WINDS WILL BE ACROSS
THE NORTHERN PART OF THE LAKE TODAY AS THE PRESSURE GRADIENT
TIGHTENS AHEAD OF THE APPROACHING LOW. THE LOW WILL CROSS THE LAKE
TONIGHT TURNING WINDS MORE WESTERLY AND NORTHWESTERLY INTO SUNDAY
MORNING BUT A SHIFT TO THE SOUTHWEST IS EXPECTED BY SUNDAY AFTERNOON
AS HIGH PRESSURE RETURNS. ANOTHER SURFACE LOW WILL MOVE FROM THE
DAKOTAS TO LAKE SUPERIOR MONDAY AND MONDAY NIGHT. THE PRESSURE
GRADIENT WILL TIGHTEN UP AHEAD OF THIS LOW MONDAY NIGHT AND LATEST
INDICATIONS ARE THAT GUSTS COULD PUSH 30 KT ACROSS THE NORTHERN
THIRD OR SO OF THE LAKE MONDAY EVENING. WINDS WILL THEN TURN NORTH
AND NORTHEAST AS THE LOW PASSES AND A COOL FRONT PUSHES SOUTHWARD
LATE TUESDAY OR EARLY WEDNESDAY. WINDS SHOULD REMAIN ELEVATED BEHIND
THE LOW WITH SPEEDS GENERALLY IN THE 15 TO 20 KT RANGE INTO
WEDNESDAY NIGHT. HIGH PRESSURE WILL THEN REMAIN ACROSS THE LAKE INTO
THE END OF THE WEEK KEEPING LIGHTER WINDS IN PLACE.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
311 PM EDT SAT JUL 14 2012
.SHORT TERM...
OTHER THAN BAND OF ISOLD CONVN FORMING ALG NRN EDGE OF SUB-TROPICAL
MSTR PLUME THIS AFTN...ATTN FOCUSED ON SLW EWD PROGRESSION OF MCV
OVR NE IL EMBEDDED WITHIN LARGER SCALE TROUGHING ANCHORED BY POTENT
SW SEEN IN VAPOR OVR NE MN. TAIL END OF IL MCV ACTIVELY CONVG
THROUGH E/NE IL ATTM WITHIN AXIS OF STG SFC BASED
HEATING/DESTABILIZATION. SHRT TERM RUC SOLUTIONS CARRY ORGANIZING
CLUSTER FM KMDW - S OF KIKK E/NEWD THROUGH NWRN CWA LT THIS
AFTN/EVE AND HAVE GENERALLY BOUGHT INTO ITS SOLUTION...DROPPING
POP/WX MENTION AFT 03Z.
OTHERWISE NRN STREAM SW TROUGH AND ASSOCD SFC TROUGH WILL BUCK EWD
THIS PD W/UNFVRBL TIMING SUN AFTN AND PER GENERAL WKNG OF UPR TROUGH
AND POORLY ALIGNED LL FLW SWD THROUGH THE OH VALLEY...MEASURABLE
PCPN CHCS APPEAR SLIM AND FIT IN CONTEXT OF HIGHRES INDICATIONS OF
AT BEST ISOLD AFTN DVLPMNT OVR FAR ERN/SERN AREAS. THUS PER THE
PREPONDERANCE OF MODEL BASED GUIDANCE WILL CHOP CONSIDERABLY AND
CONFINED TO SUN AFTN PD ALONE. TEMPS CONTD WELL ABV NORMAL THROUGH
THE PD.
&&
.LONG TERM...MONDAY THROUGH SATURDAY
MID LEVEL HEIGHTS TO BUILD ACROSS THE SOUTHERN GREAT LAKES REGION ON
MONDAY AS VORT FILAMENT CONTINUES TO GET ELONGATED AND WEAKEN FROM
NEW ENGLAND INTO THE MID MS RIVER VALLEY. MEANWHILE...UPPER LOW
WHICH HAS BEEN DIVORCED FROM MAIN WESTERLIES ACROSS THE PACIFIC
NORTHWEST WILL EVENTUALLY GET ABSORBED BY A STRONGER PV ANOMALY
DROPPING SOUTHWARD ACROSS BC CANADA. SEVERAL WEAK DISTURBANCES WILL
EJECT EASTWARD FROM THIS PV ANOMALY ACROSS FAR SOUTHERN CANADA/GREAT
LAKES REGION INTO TUESDAY...THROUGH THE BASE OF HUDSON BAY UPPER
LEVEL TROUGH. THIS WILL EVENTUALLY ALLOW A COOL FRONT TO DROP
SOUTHWARD ACROSS THE SOUTHERN GREAT LAKES TUESDAY NIGHT INTO
WEDNESDAY. IN THE MEANTIME...STRONGER WEST/SOUTHWEST LOW LEVEL FLOW
BETWEEN LOW LEVEL TROUGHING TO THE NORTHWEST AND SOUTHEAST CONUS
ANTICYCLONE. THIS WILL ALLOW A WEST TO EAST ORIENTED LOW LEVEL
THERMAL RIDGE TO ADVECT EASTWARD IN ADVANCE OF THE COOL FRONT
MONDAY/TUESDAY. MORE FAVORABLE LOW LEVEL THERMAL RIDGE POSITIONING
ON TUESDAY SHOULD MAKE THIS THE HOTTEST DAY OF THE PERIOD...ALTHOUGH
WILDCARD WILL BE POTENTIAL OF SOME CIRRUS BLOWOFF FROM UPSTREAM
CONVECTION. COMPLICATING THE TEMPERATURE FORECAST THIS PERIOD ARE
LARGE DIFFERENCES IN GUIDANCE THERMODYNAMIC PROFILES. 12Z NAM
SUGGESTS MIXING UP TO ABOUT 725 HPA TUESDAY AFTERNOON WHILE GFS IS
MOISTER AND MUCH MORE SHALLOW WITH MIXING. HAVE GENERALLY DISCOUNTED
GFS IDEA WITH MOIST LOW LEVEL BIAS AS OF LATE...WITH MORE WEIGHT TO
THE DEEPER MIXED NAM...ALTHOUGH THIS SOLUTION MAY BE TOO WELL MIXED.
THIS LARGELY SUPPORTS GOING HIGHS IN THE MID TO UPPER 90S AND HAVE
SLIGHTLY ADJUSTED PREVIOUS FORECAST UPWARD...ALTHOUGH POTENTIAL
AFOREMENTIONED HIGH CLOUD ISSUES WILL NEED TO BE CONSIDERED. MAY
NEED TO CONSIDER HEAT HEADLINES EVENTUALLY FOR TUESDAY WITH HEAT
INDICES AROUND 100 EXPECTED.
NO SIGNIFICANT CHANGES MADE TO LOW CHANCE TSRA POPS LATE TUESDAY
NIGHT ACROSS THE NORTH...EXPANDING ACROSS REMAINDER OF FORECAST AREA
WEDNESDAY WITH THE FRONT. LIMITING FACTORS FOR ORGANIZED CONVECTION
ARE MORE SUBSTANTIAL SHEAR PROFILES WELL BEHIND THE FRONT...LIMITED
MID LEVEL LAPSE RATES...AND STRONGER UPPER FORCING TRACKING ACROSS
THE NORTHERN GREAT LAKES. COOLER CONDITIONS FOR THURSDAY AND FRIDAY
BEHIND THE FRONT...ALTHOUGH IT APPEARS HEAT WILL RETURN AS UPPER
RIDGING BUILDS BACK INTO THE AREA JUST BEYOND THIS FORECAST PERIOD.
LOCAL AREA COULD BE PRONE TO CONVECTIVE CHANCES IN ADVANCE OF THIS
BUILDING RIDGE TOWARD THE END OF THE PERIOD...BUT CONFIDENCE MUCH TO
LOW TO INCLUDE IN ONGOING VERY DRY PATTERN.
&&
.AVIATION...
BROKE FM 12Z CONTINUITY AND CARRIED BRIEF TEMPO TSRA GROUPING AT
BOTH TERMINALS THIS AFTN CORRESPONDING W/NWD ADVTN OF SUB-TROPICAL
MSTR PLUME WHICH WAS SPRUNING A NWD ADVG LINE OF ISOLD-SCT CONVN
THIS AFTN. APPEARS THIS WILL LARGELY MISS KFWA YET MAY NEED TO BE
EXTENDED IN A LTR UPDATE AT KSBN. WILL CONT TO MONIOR NR TERM CONV
DVLPMNTS. OTHERWISE VFR CONDS XPCD TO CONT THROUGH THE PD W/SFC
WINDS BLO 10KTS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...T
LONG TERM...MARSILI
AVIATION...T
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1242 PM CDT SAT JUL 14 2012
.AVIATION...
THUNDERSTORM CHCS AND FOG MAIN ITEMS FOR 18Z TAFS. PCPN SHIELD
MAINLY LIGHT RAIN WITH EMBEDDED THUNDER MOVING SWD PASSING NEAR
KDBQ AND KCID TERMINALS ATTIM. HAVE GONE WITH VCTS WORDING AT BOTH
SITES UNTIL 19Z AS MAIN FOCUS FOR SCATTERED STORMS PUSHES SOUTH
WITH OUTFLOW BOUNDARY REST OF THIS AFTN. HAVE CONTINUED VCTS
WORDING FOR A FEW HRS MID TO LATE AFTN AT KMLI AND KBRL AHEAD OF
THE OUTFLOW. ANY STORMS WILL HAVE POTENTIAL FOR HAIL AND GUSTY
WINDS AND MVFR TO LOCALLY IFR CONDITIONS MOSTLY DUE TO LOWER
VSBYS. OUTFLOW BOUNDARY SHOULD SHIFT E OF AREA THIS EVE ALONG WITH
AN UPPER LEVEL DISTURBANCE WITH PCPN ENDING. VERY WEAK LOW LEVEL WIND
FIELDS AND RATHER DIFFUSE SURFACE PATTERN COUPLED WITH LOW LEVEL
MOISTURE WILL BRING MORE FOG OVRNGT INTO EARLY SUN AM WITH MVFR TO
LOCALIZED IFR AND POSSIBLY LIFR VSBYS.
&&
.PREV DISCUSSION... /ISSUED 1022 AM CDT SAT JUL 14 2012/
UPDATE...
LINE OF STORMS SAGGING INTO NW CWA ATTIM. HAVE RAISED POPS
MAINLY N/NW SECTIONS REST OF TDY WHERE BETTER UPPER SUPPORT
PROGGED IN FORM OF MID LEVEL SHORTWAVE. ISOLD SEVERE STORM
WITH STRONG WINDS TO 60 MPH AND HAIL TO AROUND QUARTER SIZE
NOT OUT OF QUESTION IN MAINLY PULSE TYPE ENVIRONMENT. WILL
CONTINUE TO MONITOR TRENDS FOR ANY ADDITIONAL UPDATES TO FCST.
PREV DISCUSSION... /ISSUED 651 AM CDT SAT JUL 14 2012/
UPDATE...
THE FCST WILL BE UPDATED SHORTLY TO REFLECT CURRENT TRENDS.
CONVECTION EAST OF THE MISSISSIPPI IS GENERALLY SUPPORTED BY LIFT
AHEAD OF THE FIRST SHORTWAVE CROSSING THE MISSISSIPPI. THIS
CONVECTION IS SLOWLY DISSIPATING AND SHOULD END OR EXIT THE CWFA
AROUND MID MORNING. THE NEXT VORT MAX/SHORTWAVE OVER NORTHERN IOWA
WILL DROP SOUTHEAST DURING THE MORNING AND HELP INITIATE NEW
CONVECTION BY LATE MORNING AND CONTINUING THROUGH THE AFTERNOON.
BASED ON FCST SOUNDINGS...THE DIURNAL CONVECTION SHOULD BE FAIRLY
HIGH BASED WHICH COULD PRODUCE LOCALLY GUSTY WINDS. 08
AVIATION...
MVFR AND SPOTTY IFR VSBYS WILL IMPROVE TO VFR BY 15Z/14. OTHERWISE
VFR CONDITIONS WILL BE SEEN THROUGH 06Z/15. VCSH WILL SLOWLY END
PRIOR TO 18Z WITH NEW CONVECTION STARTING AROUND 18Z/14 AND
CONTINUING THROUGH SUNSET. VCTS WAS ADDED TO ALL TAF SITES FOR THE
DIURNAL CONVECTION. CIGS WITH CONVECTION SHOULD REMAIN VFR BUT
BRIEF MVFR VSBYS WILL BE POSSIBLE. AFT 06Z/15 LIGHT WINDS SHOULD
ALLOW MVFR AND POSSIBLY IFR CONDITIONS TO DVLP. 08
PREV DISCUSSION... /ISSUED 319 AM CDT SAT JUL 14 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS SEVERAL SUBTLE TROFS FROM LAKE MICHIGAN BACK
INTO MINNESOTA WITH A COLLAPSING MESOHIGH NEAR KRST. DEW POINTS WERE
GENERALLY IN THE 60S WITH 70S IN THE DEEP SOUTH AND LOWER OHIO
VALLEY. RADAR TRENDS OVER THE PAST SEVERAL HOURS SHOWS OVERALL
CONVECTION IS SLOWLY DISSIPATING.
SHORT TERM...TODAY AND TONIGHT...
PRECIPITATION SINCE MIDNIGHT HAS EITHER ENDED OR DIMINISHED TO
SPRINKLES/ISOLATED SHRA. EAST OF THE MISSISSIPPI ELEVATED CONVECTION
HAS PERSISTED OR DEVELOPED. RAP TRENDS SHOW THE CONVECTION IS MAINLY
ASSOCIATED WITH SPEED/MOISTURE CONVERGENCE AT 850MB IN RELATIVELY
STRONG LIFT AHEAD OF THE VORT MAX THAT IS ALONG THE MISSISSIPPI. RAP
TRENDS INDICATE THAT THIS ELEVATED CONVECTION WILL PERSIST THE
REMAINDER OF THE NIGHT AND SHOULD DISSIPATE OR EXIT THE CWFA AROUND
MID MORNING.
WEST OF THE MISSISSIPPI SPRINKLES OR ISOLATED ELEVATED CONVECTION
WILL PERSIST OR POSSIBLY DEVELOP AS THE NEXT VORT MAX DROPS INTO THE
TROF FROM NORTHERN IOWA.
FROM LATE MORNING AND CONTINUING INTO THE AFTERNOON...DIURNAL
HEATING WILL ALLOW NEW CONVECTION TO BREAK OUT ACROSS THE CWFA.
BASED ON THE PROJECTED LOCATION OF THE VORT MAXES AND NEGATIVE THETA
E LAPSE RATES...AREAS ALONG/EAST OF THE MISSISSIPPI SHOULD HAVE THE
BETTER CHANCES OF SEEING CONVECTION. THUS THE HIGHER POPS WILL BE
ALONG/EAST OF THE MISSISSIPPI FROM LATE MORNING THROUGH THE
AFTERNOON.
CONVECTION THAT DEVELOPS DURING THE AFTERNOON WILL PERSIST INTO THE
EVENING AND SLOWLY DISSIPATE WITH SUNSET. AFTER MIDNIGHT GENERALLY
DRY CONDITIONS SHOULD BE SEEN WITH SUBSIDENCE BEHIND THE DEPARTING
SHORT WAVE AND BUILDING HEIGHTS. ..08..
LONG TERM...SUNDAY THROUGH FRIDAY...
HEAT AND MORE HUMID CONDITIONS WILL RETURN TO THE REGION FOR THE
FIRST HALF OF THE WEEK AS THE WESTERN U.S. UPPER RIDGE EDGES EAST
INTO THE PLAINS. THE DEVELOPING UPPER RIDGE WILL KEEP THE AREA DRY
SUNDAY AND MONDAY. WITH INCREASING SOUTHERLY FLOW AND WAA TEMP
WILL TOP OUT IN THE LOW TO MID 90S SUNDAY AND MAINLY MID 90S FOR
MONDAY. HELD DEW POINTS IN THE MID/UPPER 60S BOTH DAYS WHICH WILL
SUPPORT HEAT INDEX VALUES IN THE 95 TO AROUND 100 RANGE BOTH DAYS.
TUESDAY INTO THURSDAY A DEVELOPING TROF OVER GREAT LAKES AND NEW
ENGLAND WILL SENT A COLD FRONT SOUTH THROUGH THE REGION. THE FRONT
WILL TAKE THE EDGE OFF THE EARLY WEEK HEAT AND IT WILL ALSO
PROVIDE A CHANCE OF RAIN FOR THE REGION. THE FORECAST WAS SKEWED
TOWARD THE ECMWF WHICH BRINGS THE FRONT THROUGH SLOWER THAN THE
OTHER MODELS...ESPECIALLY THE GFS. THE SLOWER MOVEMENT SEEMS
REASONABLE WITH THE FRONT MOVING INTO THE UPPER RIDGE. ALSO MODELS
ARE SHOWING WARM MID LEVELS ALONG AND AHEAD OF THE BOUNDARY
SUGGESTING THE WARM SECTOR WILL BE CAPPED. WITH ALL THE PRECIP
EXPECTED TO BE POST FRONTAL HAVE KEPT TUESDAY DRY AND LIMITED POPS
TUESDAY NIGHT TO THE NORTH HALF. LOW CHANCE POP WERE MAINTAINED
OVER THE ENTIRE AREA WEDNESDAY THEN STARTED TO DRY THE FORECAST OUT
FROM NORTH TO SOUTH WEDNESDAY NIGHT INTO FRIDAY AS THE BOUNDARY PUSHES
FAR ENOUGH SOUTH. WITH THE WARM MID LEVEL TEMPERATURES IN PLACE
AND FORCING ALONG AND NORTH OF THE FRONT REMAINING WEAK ANY
SHRA/TSRA OCCURRING WITH THIS SYSTEM SHOULD BE SCATTERED.
THE FRONT WILL ALSO BRING SOME SLIGHTLY COOLER TEMPERATURES TO THE
AREA FOR MID TO LATE WEEK. HEAT INDEX VALUES AROUND 100 ARE
EXPECTED OVER THE ENTIRE AREA TUESDAY BUT SHOULD BE LIMITED TO THE
SOUTH HALF OF THE AREA WEDNESDAY AND THURSDAY.
DLF
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
437 PM CDT SAT JUL 14 2012
...UPDATE TO LONG TERM...
.SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 304 PM
CDT SAT JUL 14 2012
A RIDGE OF UPPER LEVEL HIGH PRESSURE WILL DOMINATE THE HIGH PLAINS
FROM NEW MEXICO INTO WESTERN KANSAS AND NEBRASKA INTO SUNDAY. A LEE
TROUGH OF LOW PRESSURE WILL ALSO REMAIN IN EASTERN COLORADO WITH
LIGHT SOUTH TO SOUTHEAST WINDS TONIGHT. THE PRESSURE GRADIENT THEN
TIGHTENS ON SUNDAY WITH SOUTH TO SOUTHWEST WINDS OF 15 TO 25 MPH AND
GUSTY. A MID LEVEL CAPPING INVERSION WILL ALSO CONTINUE INTO SUNDAY
AFTERNOON, AND WITH TEMPERATURES APPROACHING 100, THE CAP MAY WEAKEN
ENOUGH TO SUPPORT SOME HIGH BASED THUNDERSTORMS LATE THIS AFTERNOON
INTO EARLY EVENING AND AGAIN ON SUNDAY. WILL ADD A SLIGHT CHANCE OF
THUNDER MAINLY EAST OF A LINE FROM WAKEENEY TO MEADE. WITH DEWPOINTS
ALSO MIXING OUT, IF ANY THUNDERSTORMS FORM, THEY COULD PUT OUT SOME
LOCALLY STRONG GUSTS FROM 40 TO 50 MPH. THE HRRR MESOSCALE MODEL
ALSO SUPPORTS A FEW THUNDERSTORMS LATE THIS AFTERNOON AND EARLY
EVENING.
OVERNIGHT LOWS WILL BE MILD AND IN THE MID TO UPPER 60S UNDER MOSTLY
CLEAR SKIES. FOR SUNDAY EXPECT HIGHS NEAR THE CENTURY MARK WITH
MOSTLY CLEAR TO PARTLY CLOUDY SKIES.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 435 PM CDT SAT JUL 14 2012
THERE WERE LITTLE OVERALL CHANGES IN EXPECTATIONS NOTED FOR THE
EXTENDED FORECAST PERIOD. THE GENERAL PATTERN CONTINUES TO INDICATE
A WEAKLY POSITIVE TILTED UPPER RIDGE BUILDING INTO THE GREAT PLAINS.
THE RIDGE BECOMES SLOWLY FLATTENED WITH TIME AS SHORTWAVES RIDE THE
NORTHERN PERIPHERY OF THIS RIDGE THROUGH THE WEEK. THIS WARM AIRMASS
WILL BE MARKED BY WARM TEMPERATURES IN THE MID TO UPPER 90S, AND
TEMPERATURES AROUND 100 DEGREES BY MID TO LATE WEEK. CAPPING IS
WEAK, ESPECIALLY ACROSS CENTRAL KANSAS WHERE 700 MB TEMPERATURES ARE
UNDER 10 DEGREES C. AN ISOLATED BRIEF AIRMASS THUNDERSTORM CANNOT
BE COMPLETELY RULED OUT ANY DAY, BUT CHANCES ARE QUITE LOW GIVEN THE
LACK OF NOTED SURFACE CONVERGENCE. THE BEST CHANCES MIGHT BE FARTHER
WEST AND SOUTH ON THE HIGHER TERRAIN OF THE PANHANDLES AND EASTERN
COLORADO. SOUTHWEST KANSAS SHOULD REMAIN IN A WARM SECTOR THROUGH HE
ENTIRE PERIOD, WHILE A STATIONARY FRONT RUNNING FROM IOWA THROUGH
NEBRASKA AND SOUTH DAKOTA SHOULD BE A FOCUS FOR MESOSCALE CONVECTIVE
SYSTEMS EACH NIGHT THROUGH THE MID TO LATE WEEK, AND REMAIN FOCUSED
WELL AWAY FROM CENTRAL KANSAS. CONVECTIVE STORMS THAT DEVELOP FARTHER
WEST WILL HAVE POOR STEERING FLOW WITH SUCH LIGHT MEAN WINDS DUE TO
THE UPPER HIGH. THE ATMOSPHERE WILL PROBABLY BE MORE CONDUCIVE TO
HEAT BURSTS AND GUSTY WINDS THAN TO SEVERE THUNDERSTORMS, ESPECIALLY
WEST OF HIGHWAY 283 TO THE COLORADO LINE.
TEMPERATURES BY LATE IN THE WEEK WERE RAISED A FEW DEGREES. SOME OF
THE BIAS CORRECTED MODEL OUTPUT STATISTICS GUIDANCE IS SUPPORTIVE OF
WARMER HIGHS UNDER THE UPPER RIDGE BY FRIDAY AND SATURDAY.
WIDESPREAD TEMPERATURES IN EXCESS OF 100 DEGREES AND POSSIBLY TO
AROUND 105 ARE INDICATED BY THIS GUIDANCE, AND SEEMS QUITE
REASONABLE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1232 PM CDT SAT JUL 14 2012
AN UPPER LEVEL RIDGE WILL MOVE SLOWLY EAST ACROSS THE PLAINS WITH
A TROUGH OF LOW PRESSURE FROM EASTERN COLORADO INTO WESTERN
NEBRASKA. THE PRESSURE GRADIENT WILL TIGHTEN UP SUNDAY AFTERNOON
ACROSS WESTERN KANSAS WITH SOUTH TO SOUTHWEST WINDS INCREASING TO
15-25 KTS. EXPECT VFR CONDITIONS THROUGH THIS TAF PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 69 100 72 97 / 10 10 0 10
GCK 68 100 70 98 / 10 10 0 0
EHA 68 98 68 99 / 10 10 10 10
LBL 70 100 70 99 / 10 10 0 10
HYS 68 101 71 98 / 10 10 0 10
P28 72 99 72 96 / 20 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KRUSE
LONG TERM...RUSSELL
AVIATION...KRUSE
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
307 PM CDT SAT JUL 14 2012
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 304 PM CDT SAT JUL 14 2012
A RIDGE OF UPPER LEVEL HIGH PRESSURE WILL DOMINATE THE HIGH PLAINS
FROM NEW MEXICO INTO WESTERN KANSAS AND NEBRASKA INTO SUNDAY. A LEE
TROUGH OF LOW PRESSURE WILL ALSO REMAIN IN EASTERN COLORADO WITH
LIGHT SOUTH TO SOUTHEAST WINDS TONIGHT. THE PRESSURE GRADIENT THEN
TIGHTENS ON SUNDAY WITH SOUTH TO SOUTHWEST WINDS OF 15 TO 25 MPH AND
GUSTY. A MID LEVEL CAPPING INVERSION WILL ALSO CONTINUE INTO SUNDAY
AFTERNOON, AND WITH TEMPERATURES APPROACHING 100, THE CAP MAY WEAKEN
ENOUGH TO SUPPORT SOME HIGH BASED THUNDERSTORMS LATE THIS AFTERNOON
INTO EARLY EVENING AND AGAIN ON SUNDAY. WILL ADD A SLIGHT CHANCE OF
THUNDER MAINLY EAST OF A LINE FROM WAKEENEY TO MEADE. WITH DEWPOINTS
ALSO MIXING OUT, IF ANY THUNDERSTORMS FORM, THEY COULD PUT OUT SOME
LOCALLY STRONG GUSTS FROM 40 TO 50 MPH. THE HRRR MESOSCALE MODEL
ALSO SUPPORTS A FEW THUNDERSTORMS LATE THIS AFTERNOON AND EARLY
EVENING.
OVERNIGHT LOWS WILL BE MILD AND IN THE MID TO UPPER 60S UNDER MOSTLY
CLEAR SKIES. FOR SUNDAY EXPECT HIGHS NEAR THE CENTURY MARK WITH
MOSTLY CLEAR TO PARTLY CLOUDY SKIES.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 346 AM CDT SAT JUL 14 2012
UPPER-LEVEL RIDGING WILL REMAIN ACROSS THE CENTRAL PLAINS INTO
SUNDAY WITH A CONTINUATION OF HOT AFTERNOON TEMPERATURES AND NO
PRECIPITATION. OPTED TO GO WITH THE NAM FOR HIGH TEMPERATURES FOR
SUNDAY IN THIS DRY REGIME. THE MODELS INDICATE SOME WEAKENING OF
THE UPPER-LEVEL RIDGE BY MONDAY EVENING INTO TUESDAY, WITH AN
INCREASE IN MID-LEVEL MOISTURE ACROSS THE SOUTHERN HIGH PLAINS.
ANY THUNDERSTORMS THAT DEVELOP DURING THIS PERIOD SHOULD BE
ISOLATED AND WEAK DUE TO LIMITED SURFACE BASED CAPE, AND THE BEST
CHANCE (10-15%) WILL BE IN FAR SOUTHWEST KANSAS. I OPTED TO GO
WITH THE ECMWF MAXIMUM TEMPERATURES FOR MONDAY AND TUESDAY (UPPER
90S TO 100F) AS THIS MODEL HAS A GOOD TRACK RECORD WITH HIGH
TEMPERATURES THIS SUMMER.
BY WEDNESDAY AND THURSDAY THE ECMWF INDICATES SOME MID-LEVEL MOISTURE
MOVING NORTHWARD FROM THE TROPICS INTO THE SOUTHERN HIGH PLAINS.
ISOLATED THUNDERSTORMS CANNOT BE RULED OUT, BUT THE BEST CHANCES
WILL BE TO THE SOUTH AND WEST ON THE ELEVATED TERRAIN. TEMPERATURES
WILL REMAIN HOT AND OPTED AGAIN TO USE THE ECMWF HIGH TEMPERATURES,
WHICH WERE GENERALLY 95 TO 100F. LOW TEMPERATURES SHOULD MANAGE TO FALL
INTO THE UPPER 60S TO MID 70S GIVEN THE FAIRLY LIGHT WINDS.
BY FRIDAY AND SATURDAY, THE ECMWF BUILDS A STRONGER RIDGE BACK OVER
WESTERN KANSAS. THUS, HIGH TEMPERATURES MAY EXCEED 100F DURING THIS
PERIOD. AGAIN, LOW TEMPERATURES SHOULD MANAGE TO FALL INTO THE
UPPER 60S TO MID 70S GIVEN THE FAIRLY LIGHT SOUTHERLY WINDS AT 10
KTS OR LESS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1232 PM CDT SAT JUL 14 2012
AN UPPER LEVEL RIDGE WILL MOVE SLOWLY EAST ACROSS THE PLAINS WITH
A TROUGH OF LOW PRESSURE FROM EASTERN COLORADO INTO WESTERN
NEBRASKA. THE PRESSURE GRADIENT WILL TIGHTEN UP SUNDAY AFTERNOON
ACROSS WESTERN KANSAS WITH SOUTH TO SOUTHWEST WINDS INCREASING TO
15-25 KTS. EXPECT VFR CONDITIONS THROUGH THIS TAF PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 69 100 72 97 / 10 10 0 10
GCK 68 100 70 98 / 10 10 0 0
EHA 68 98 68 99 / 10 10 10 10
LBL 70 100 70 99 / 10 10 0 10
HYS 68 101 71 98 / 10 10 0 10
P28 72 99 72 96 / 20 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KRUSE
LONG TERM...FINCH
AVIATION...KRUSE
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
345 PM EDT SAT JUL 14 2012
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 335 PM EDT SAT JUL 14 2012
19Z SFC ANALYSIS SHOWS A WEAK PRESSURE PATTERN THROUGHOUT EAST
KENTUCKY WITH NO CLEAR SYNOPTIC SCALE FEATURES TO KEY IN ON.
HOWEVER...GIVEN THE HIGH PW AIR IN PLACE...NO CAP...AND SOME UPPER
LEVEL ENERGY...NOT MUCH WAS NEEDED TO INITIATE THE STORMS LATE THIS
MORNING THAT CONTINUE TO PERCOLATE OVER THE CWA AT THIS HOUR. THE
CLOUDS FILLED IN FROM THE SOUTH BY MID MORNING AND CONVECTION
FOLLOWED SHORTLY THEREAFTER. A FEW OF THE CELLS HAVE GOTTEN STRONG
AND OTHERS HAVE MERGED/TRAINED OVER THE SAME SPOTS CREATING A CONCERN
FOR MINOR URBAN OR SMALL STREAM FLOODING. REGARDLESS...THE RAINS IN
MANY LOCATIONS ARE NOW PUTTING A SERIOUS DENT IN THEIR ANNUAL
RAINFALL DEFICIT THANKS TO THESE PAST FEW DAYS. TEMPERATURES THIS
AFTERNOON HAVE BEEN HIGHLY DEPENDENT ON THE CONVECTIVE PATTERN AND
BREAKS FOR SUNSHINE WITH READINGS CURRENTLY RANGING FROM THE LOW 70S
IN THE RAIN COOLED SOUTHERN I-75 CORRIDOR TO MID 80S JUST SOUTH OF
STORMS NEAR I-64 AND IN THE...THUS FAR RAIN FREE...FAR SOUTHEAST.
DEWPOINTS...MEANWHILE...REMAIN PEGGED IN THE LOW TO MID 70S SUPPLYING
ALL THE JUICE THE CONVECTION COULD NEED.
THE MODELS REMAIN IN AGREEMENT THAT EAST KENTUCKY WILL BE ON THE
FRINGE OF THE WESTERN EXTENT OF A WEAK BERMUDA RIDGE AND AHEAD OF
TROUGHING COMING FROM THE NORTHERN PLAINS AND CROSSING THE GREAT
LAKES ON SUNDAY. THE ENERGY FROM THIS TROUGH WILL PASS BY TO THE
NORTH LATER SUNDAY AND THIS WILL SERVE TO FURTHER LIMIT THE EFFECT OF
THE EASTERN RIDGE ON OUR WEATHER INTO THE START OF THE NEW WORK WEEK.
IN THIS ENVIRONMENT THE MESOSCALE...OR SMALLER...WILL DOMINATE SO
HAVE LEANED MOST HEAVILY ON THE DETAILS OF THE NAM12 WITH A HEALTHY
DOSE OF THE HRRR EARLY ON TONIGHT.
SENSIBLE WEATHER WILL FEATURE SHOWERS AND THUNDERSTORMS WINDING
DOWN...FOR THE MOST PART...AFTER SUNSET...BUT NOT BEFORE LEAVING
BEHIND A FAIR AMOUNT OF RAINFALL IN SEVERAL LOCATIONS. EXPECT A LULL
THROUGH THE MIDDLE OF THE NIGHT WITH PATCHY FOG A GOOD BET. THE
APPROACH OF A SHORTWAVE INTO THE OHIO VALLEY LATE TONIGHT GIVES SOME
CREDENCE TO THE NAM12/S IDEA OF A CONVECTIVE CLUSTER FORMING OVER
CENTRAL TENNESSEE AND DRIFTING INTO THE CUMBERLAND VALLEY BY DAWN.
SOME SUPPORT FROM THE GFS BOLSTERS THIS IDEA...AS WELL. ACCORDINGLY...
HAVE DEVIATED FROM A STRICTLY DIURNALLY DRIVEN POP AND WX PATTERN TO
ALLOW FOR THIS IDEA IN THE GRIDS...THOUGH NOT WHOLE HOG JUST YET.
OTHERWISE...EXPECT A NEAR REPEAT OF TODAY FOR SUNDAY WITH CONVECTION
DRIVEN MAINLY BY DIURNAL HEATING AND MINOR OUTFLOWS/DIFFERENTIAL
HEATING BOUNDARIES. FOR BOTH TONIGHT AND SUNDAY NIGHT HAVE BEEN
GENEROUS WITH THE PATCHY FOG IN THE GRIDS AFTER MIDNIGHT...BUT HELD
OFF ON ANY DENSE UNTIL IT BECOMES MORE APPARENT WHERE THE BEST
NOCTURNAL CLEARING WILL OCCUR.
FOR TEMPERATURES...FOLLOWED A BLEND OF THE INHERITED GRIDS...
PERSISTENCE...AND SOME OF THE LATEST MET VALUES...AGAIN NOT MUCH IN
THE WAY OF TERRAIN EFFECTS FOR LOWS GIVEN THE HIGH DEWPOINTS. AS FOR
POPS...HAVE ENDED UP SIMILAR TO A BLEND OF THE MET AND MAV MOS
THROUGHOUT THE PERIOD.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 340 PM EDT SAT JUL 14 2012
THE MODELS REMAIN IN VERY GOOD AGREEMENT WITH THE GENERAL LONG WAVE
PATTERN THROUGH THE EXTENDED. A SHORT WAVE TROUGH WILL BE EXITING
THE APPALACHIANS ON MONDAY...HELPING TO TEMPORARILY BUCKLE
RIDGING ACROSS THE PLAINS AND INTO THE MISSISSIPPI VALLEY THROUGH
TUESDAY. THE RIDGE WILL THEN BUILD BACK IN STRONGER ACROSS THE
PLAINS...WITH A MORE VIGOROUS SHORT WAVE TROUGH TO MOVE THROUGH THE
GREAT LAKES AND NEW ENGLAND FOR WEDNESDAY AND THURSDAY...SENDING A
COLD FRONT SOUTH ACROSS THE OHIO VALLEY. THE MODELS HAVE COME ON
BOARD A BIT MORE...WITH A MORE PROGRESSIVE SOLUTION FOR THESE
FEATURES. FOR EASTERN KENTUCKY...THIS WILL KEEP THE THREAT OF
SCATTERED...MAINLY DIURNALLY DRIVEN CONVECTION ACROSS MOST OF THE AREA
THROUGH FRIDAY...BEFORE DEEPER MOISTURE SINKS FAR ENOUGH SOUTH ON
SATURDAY...TO ONLY JUSTIFY A FEW POPS UP ALONG THE TN/VA BORDER.
TEMPERATURES CONTINUE TO LOOK SLIGHTLY ABOVE NORMAL...WITH
PERSISTENT HUMIDITY UNTIL NEXT WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 240 PM EDT SAT JUL 14 2012
ANOTHER TRICKY AVN FORECAST WITH DIURNALLY DRIVEN CONVECTION TAPERING
OFF THIS EVENING AND THEN PERHAPS A RENEWAL TOWARDS DAWN AS A
SHORTWAVE COMES THROUGH. THE DIURNAL EFFECT WILL KICK IN AGAIN ON
SUNDAY WITH ANOTHER ROUND OF SCATTERED TO NUMEROUS STORMS. HAVE
PLAYED THE NEAR TERM STORMS WITH A TEMPO FOR MVFR OR WORSE
CONDITIONS. DID ALSO INCLUDE SOME FOG IN THE TAFS AFTER MIDNIGHT
TONIGHT. OUTSIDE OF ANY STORM...WINDS WILL BE LIGHT AND GENERALLY
FROM THE SOUTH.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM....GEOGERIAN
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
304 PM EDT SAT JUL 14 2012
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH THROUGH THE REGION THIS AFTERNOON AND
EVENING. AN UPPER TROUGH WILL PROGRESS THROUGH THE NORTHERN MID-
ATLANTIC REGION SUNDAY. HIGH PRESSURE BUILDS IN EARLY NEXT
WEEK...BUT A COLD FRONT WILL MOVE THROUGH ON WEDNESDAY. HIGH
PRESSURE IS FORECAST TO RETURN LATE NEXT WEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
UPPER RIDGE AXIS/SFC HIPRES REMAINS CENTERED OVER THE CAROLINAS. 18Z
SFC ANALYSIS REVEALS A DIFFUSE WARM FRONT OVER CENTRAL VA AND SRN
MD. THIS BOUNDARY IS DEPICTED BY LGT E-NE WINDS/ TEMPS IN THE MID
TO UPPER 70S/ DEWPOINTS IN THE UPPER 60S TO THE NORTH...AND SLY
WINDS/ TEMPS IN THE MID TO UPPER 80S/ DEWPOINTS IN THE LOW 70S TO
THE SOUTH. DIFFERENTIAL HEATING HAS ENHANCED THE TEMP GRADIENT
NEAR THE BOUNDARY OVER THE PAST FEW HRS SINCE BREAKS IN THE CLOUD
COVER HAVE OCCURRED IN THE WARM SECTOR.
PAST SEVERAL RUNS OF THE HRRR AND LOCAL WRF ARW4N/NMM4N HAVE
CONSISTENTLY DEVELOPED CONVECTION ALONG AND SOUTH OF THE BOUNDARY
THIS AFTN IN THE WRN HIGHLANDS...CENTRAL/SRN VA AND SRN MD. WHILE
INITIATION HAS OCCURRED QUICKER THAN MODELS INDICATED...THE
LOCATION SEEMS REASONABLE.
THE MOIST ENVIRONMENT IS SUPPORTIVE OF EFFICIENT RAINFALL
PRODUCERS AND HI-PRECIP RATES...WITH A DEEP WARM CLOUD LAYER AND
PWATS OVER 2 INCHES. A FLASH FLOOD WATCH WAS ISSUED FOR THE
CENTRAL FOOTHILLS...SHENANDOAH VLY AND POTOMAC HIGHLANDS THRU
MIDNIGHT...WHERE COVERAGE AND POTENTIAL FOR STORM TRAINING SHOULD
BE GREATEST. DECIDED NOT TO EXPAND FF WATCH EWD INTO THE CITIES AS
COVERAGE OF STORMS IS EXPECTED TO BE LOWER AND FLASH FLOOD THREAT
MORE LOCALIZED.
THE WARM FRONT WILL GRADUALLY LIFT NWD THRU THE NRN HALF OF THE CWA
THIS EVE. SHOWERS AND STORMS WILL EVENTUALLY EXPAND NEWD INTO THE
CITIES DURING THE ERY EVE. WITH THE LOSS OF DAYTIME HEATING AND LACK
OF ORGANIZED LIFT...ACTIVITY IS EXPECTED TO DIMINISH LATE THIS EVE.
TRIED TO KEEP THE FCST DRY LATE TNGT/ERY SUN MRNG...BUT A STRAY
SHOWER OR STORM CANNOT BE RULED OUT IN THIS TROPICAL AIRMASS...
ESPECIALLY NEAR THE MASON-DIXON LINE AND ALLEGHENY FRONT.
ON SUN...THE REGION WILL BE SITUATED ON THE NRN PERIPHERY OF THE
UPPER RIDGE AND DOWNSTREAM OF A SHORTWAVE TROUGH THAT WILL BE MOVING
OVER THE GREAT LAKES REGION. MAX TEMPS IN THE LOW TO MID 90S AND
DEWPOINTS IN THE LOW 70S WILL YIELD A MODERATE AMT OF INSTABILITY
DURING THE AFTN. 12Z MODELS HAVE TRENDED SLIGHTLY SLOWER AND
FARTHER NORTH WITH THE SHORTWAVE TROUGH. LOCATION AND TIMING OF
INGREDIENTS FOR A SEVERE TSTM EPISODE IS IN QUESTION AS LIFT
ASSOCIATED WITH THE TROUGH MAY REMAIN NORTH OF THE AREA AND COME
AFTER THE PEAK DAYTIME HRS. WILL STILL MENTION OUTSIDE THREAT IN
HWO...AND FOCUS THREAT MAINLY OVER THE NRN CWA.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
SUN NGT...CDFNT WILL CONT SLIDING ACRS CWA...WITH SHWRS/TSTMS
GRADUALLY DIMINISHING IN STRENGTH AND CVRG. ULVL RIDGE TAKES HOLD
BY MON...TRIGGERING SVRL DAYS OF MUCH ABV NRML TEMPS. MAXIMA SHUD BE
IN 90S MON/TUE...WITH MINIMA MOSTLY IN 70S. DAILY RECORD HIGH
MINIMUM TEMPS MAY BE THREATENED AT THE CLIMATE SITES...AND HEAT
HEADLINES MAY BE WARRANTED FOR SOME AREAS. CHC FOR CNVCTN IN
VICINITY OF AFOREMENTIONED CDFNT...BUT 12Z GUIDANCE PUSHES THIS
FEATURE FURTHER S INTO SRN VA...SO FCST FOR CWA IS DRY MON/TUE.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
RIDGE WILL FLATTEN SLIGHTLY WED AS ULVL SHRTWV TROF DIGS THRU NEW
ENGLAND. A CDFNT WILL APPROACH WED AND MOVE THRU BY WED NGT. S OF
FRONT...MOIST ATMOSPHERE AND HOT TEMPS MAY AGAIN WARRANT HEAT
HEADLINES FOR SOME AREAS...ESPECIALLY E OF BLUE RIDGE. WITH TEMPS
WELL INTO 90S...SBCAPE VALUES SHUD REACH AOA 2000 J/KG WED
AFTN...AND SHEAR WILL INCR. TSTMS SHUD DVLP ALONG/AHEAD OF FRONT AND
MOVE ACRS CWA...AND SOME MAY BE SVR. LIMITING FACTORS WILL BE DECENT
CAP...AND RATHER MODEST FORCING...WITH BEST DYNAMICS RMNG WELL N OF
MID-ATLC. STILL SOME MODEL DISAGREEMENT IN HOW FAST THIS SYSTEM WILL
EXIT CWA...WITH LATEST GUIDANCE PROPOSING FASTER SOLN/DRIER THU.
FOR NOW...WILL HOLD ONTO LOW POPS THRU THU...BEFORE HIPRES BUILDS
IN. AFTER FROPA...TEMPS WILL MODERATE TO SLIGHTLY ABV NRML FOR THE
LATTER PORTIONS OF WK.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
FOR THIS AFTERNOON AND EVENING...SHOWERS AND THUNDERSTORMS MAY
BRIEFLY REDUCE CIGS TO MVFR LEVELS. OCCASIONAL VSBY REDUCTIONS TO
5SM OR BELOW ARE POSSIBLE IN HEAVIER SHOWERS AND STORMS.
OVERNIGHT...RH LEVELS WILL REMAIN HIGH WITH PATCHY FOG POSSIBLE
AT CHO...IAD AND MRB. ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS
ARE POSSIBLE TOMORROW AFTERNOON AS A FRONT REMAINS NEAR THE AREA.
VSBY/CIG RESTRICTIONS MAY PERSIST THRU SUN NGT WITH SCT/NUM
SHWRS/TSTMS SLOWLY DIMINISHING...BUT BOUNDARY LYR RMNG NEARLY
SATURATED. HIGH PRESSURE SHUD CREATE VFR CONDS MON/TUE. A COLD
FRONT IS PROGGED TO MOVE THRU TERMINALS WED...BRINGING WITH IT
ANOTHER CHC OF SHWRS/TSTMS AND PTNL FOR FLIGHT RESTRICTIONS.
&&
.MARINE...
WARM FRONT THIS AFTN NEAR THE MID TIDAL POTOMAC RVR AND CENTRAL MD
PORTION OF THE CHSPK BAY. SLY FLOW HAS BACKED OUT OF THE NORTHEAST
IMMEDIATELY PRECEDING THE FRONT...FOLLOWED BY SLY FLOW IN WARM
SECTOR. MAIN CONCERN THRU THE EVE WILL BE GUSTY WINDS...LIGHTNING
AND POOR VISIBILITIES IN TSTMS. SPECIAL MARINE WRNGS...WHICH WAS
ALREADY ISSUED FOR SRN ZONES...MAY BE NECESSARY FARTHER NWD LATER
TDA.
SLY WINDS WILL LIKELY CHANNEL UP THE BAY TNGT...RESULTING IN LOCALLY
HIGHER GUSTS TO 15 KT.
MORE SHOWERS AND STORMS ARE EXPECTED SUN AFTN AS A TROUGH APPROACHES
FROM THE NW. SHOWERS AND STORMS WILL BE ACCOMPANIED BY HVY
DOWNPOURS...LIGHTNING AND LOCALLY GUSTY WINDS.
NO STRONG SYNOPTIC WINDS FCST FOR NEXT WEEK...SO NO NON-CNVCTV
HEADLINES ANTICIPATED. SHWRS/TSTMS WILL CONT INTO SUN NGT AS CDFNT
CROSSES WATERS. DRIER CONDS MON/TUE...BUT ADDITIONAL TSTMS PSBL WED
WITH ANOTHER FROPA.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR VAZ025>031-
036>040-503-504.
WV...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR WVZ050-055-
501>506.
MARINE...NONE.
&&
$$
SYNOPSIS...KLEIN/KONARIK
NEAR TERM...KLEIN
SHORT TERM...KONARIK
LONG TERM...KONARIK
AVIATION...KLEIN/KONARIK/CJL
MARINE...KLEIN/KONARIK
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
234 PM EDT SAT JUL 14 2012
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES ALONG WITH INCREASING
HUMIDITY WILL BRING SHOWERS AND A CHANCE FOR THUNDERSTORMS TO THE
AREA THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
SHOWERS AND THUNDERSTORMS DEVELOPING AS EXPECTED ALONG WARM
FRONT. SURFACE DEWPOINTS GETTING INTO THE LOWER 70S GENERALLY
SOUTH OF INTERSTATE 70 AS DEEP MOISTURE ADVECTS IN AND
PRECIPITABLE WATER VALUES INCREASING TO 1.9 TO 2 INCHES. SOME
BREAKS IN THE CLOUD COVER SOUTH OF THE WARM FRONT TRIGGERING SOME
THUNDERSTORMS. ACTIVITIY WILL CONTINUE OVERNINGHT AS WEAK PULSES
MOVE THROUGH IN THE SOUTHWEST FLOW. HRRR INDICATES THAT ACTIVITY
MAY INCREASE IN COVERAGE TO OUR SOUTHWEST AND A MOVE THROUGH THE
REGION AROUND 03Z-07Z. TEMPERATURES REACHED THE LOWER 80S SOUTH OF
THE FRONT BUT MID 70S NORTH OF IT. OVERNIGHT TEMPS ONLY IN THE
UPPER 60S TO 70.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/ ...
EXPECT ANOTHER ROUND OF WIDESPREAD SHOWERS SUNDAY MORNING ALONG A
MOISTURE CONFLUENCE REGION DEVELOPING WITH APROACHING SHORTWAVE.
DEEP MOISTURE AVAILABLE... AS PRECIPITABLE WATER FORECASTS WILL BE
VERY HI AROUND 2 INCHES. POTENTIAL FOR THE TRAINING WITH CELLS AS
THEY ORIENT THEMSELVES ALONG AN EAST WEST AXIS WITH LOCALIZED
AREAS OF HEAVY RAINFALL RATES.
GIVEN CLOUD COVER AND PRECIP TEMPS WILL BE NEAR NORMAL SEASONAL
VALUES ON SUNDAY. WITH DRIER AIR ALOFT ADVECTING INTO THE AREA,
DECREASED CLOUD COVERAGE ON MONDAY AND TUESDAY WILL ALLOW TEMPS TO
WARM TO ABOVE NORMAL, INTO THE MID TO UPPER 80S ACROSS THE
LOWLANDS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A COLD FRONT IS PROGGED TO MOVE SLOWLY SOUTHWARD ACROSS THE GREAT
LAKES AND THROUGH THE UPPER OHIO VALLEY TUESDAY NIGHT AND
WEDNESDAY. SCATTERED SHOWERS AND THUNDERSTORMS WILL ACCOMPANY THIS
BOUNDARY THROUGH WEDNESDAY EVENING. DRY CONDITIONS CAN BE EXPECTED
THURSDAY THROUGH SATURDAY AS SURFACE HIGH PRESSURE BUILDS IN ACROSS
THE GREAT LAKES AND INTO NEW ENGLAND.
STAYED CLOSE TO HPC NUMBERS WITH TEMPERATURES REMAINING BETWEEN 5
AND 10 DEGREES ABOVE NORMAL THROUGH WEDNESDAY NIGHT...THEN CLOSER TO
NORMAL FOR THE LATTER PART OF THE WEEK.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
A WARM FRONT STRETCHED ACROSS CENTRAL OH INTO SOUTHWEST PA SHOULD
PUSH SLOWLY NORTHWARD THROUGH THIS EVENING. GENERALLY MVFR CEILINGS
WILL PERSIST NORTH OF THIS BOUNDARY THROUGH THIS EVENING. VFR SHOULD
PREVAIL IN THE WARM SECTOR WITH BRIEF RESTRICTIONS IN SCATTERED
SHOWERS AND THUNDERSTORMS.
SCATTERED COVERAGE OF SHOWERS SHOULD CONTINUE INTO TONIGHT AS
SOUTHWEST FLOW CONTINUES TO BRING MOISTURE INTO THE REGION. AREAS OF
MVFR CEILINGS AND FOG WILL LIKELY FORM AT MOST TAF LOCATIONS LATE
TONIGHT. EXPECT COVERAGE OF PRECIPITATION TO INCREASE AGAIN BY
SUNDAY MORNING AHEAD OF AN APPROACHING SHORT WAVE TROUGH.
OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...
WEAK RIDGING SHOULD PROVIDE GENERALLY VFR CONDITIONS MONDAY INTO
TUESDAY. A COLD FRONT WILL SAG SOUTHWARD ACROSS THE GREAT LAKES AND
THROUGH THE OHIO VALLEY TUESDAY NIGHT AND WEDNESDAY. RESTRICTIONS
CAN BE EXPECTED IN SCATTERED THUNDERSTORMS. PREVAILING VFR WEATHER
SHOULD RETURN BY THURSDAY AS A SURFACE HIGH BUILDS IN.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BUFFALO NY
120 PM EDT SAT JUL 14 2012
.SYNOPSIS...
WARM AND MOIST AIR FROM THE OHIO VALLEY WILL BUILD INTO THE
REGION THIS WEEKEND...RESULTING IN A CONTINUATION OF ABOVE NORMAL
TEMPERATURES AND AN INCREASING CHANCE FOR SHOWERS AND THUNDERSTORMS.
SLIGHTLY DRIER AIR WILL ENTER EARLY NEXT WEEK...WHILE THE MID-SUMMER
HEAT IS FORECAST TO REMAIN IN PLACE.
&&
.NEAR TERM /THROUGH TONIGHT/...
A BROAD AREA OF HIGH PRESSURE WILL REMAIN ACROSS THE EASTERN
SEABOARD...WHICH WILL MAINTAIN A WARM SOUTHERLY FLOW ACROSS
WESTERN NEW YORK. TODAY SHOULD START OFF WITH A FAIR AMOUNT OF
SUNSHINE ACROSS WESTERN NEW YORK.
AS WAS THE CASE YESTERDAY...DIURNAL INSTABILITY WILL DEVELOP DURING
THE AFTERNOON HOURS. WHILE A WEAK UPPER LEVEL DISTURBANCE MOVED
ACROSS THE REGION YESTERDAY...GUIDANCE SUGGESTS WEAK UPPER RIDGING
THIS AFTERNOON. THE 12Z BUFFALO SOUNDING SHOWS FAIRLY STEEP LAPSE
RATES ABOVE 850 MB...BUT IT IS ALSO QUITE DRY. WHILE THIS PROBABLY
WILL NOT BE ENOUGH TO ENTIRELY SUPPRESS CONVECTION...AREAL COVERAGE
OF SHOWERS SHOULD BE LIMITED...PERHAPS EVEN A BIT LESS THAN
YESTERDAY. THIS STILL JUSTIFIES CHANCE POPS IN THE SAME REGIONS
PRONE TO SHOWERS AND THUNDERSTORMS YESTERDAY...THOUGH CELLS MAY
DEVELOP IN SLIGHTLY DIFFERENT LOCATIONS. EXPECT ISOLATED TO WIDELY
SCATTERED STORMS TO DEVELOP BY MID AFTERNOON ACROSS THE INTERIOR
SOUTHERN TIER AND GENESEE VALLEY MAINLY SOUTH OF THE THRUWAY. MEAN
QPF FORECASTS FROM THE SREF/NAM/RGEM/GFS ACTUALLY PAINT A PRETTY
GOOD GENERAL PICTURE OF THIS...AND RUNS OF THE HRRR APPEAR TO SPARK
CONVECTION SHORTLY AFTER NOON.
LAKE BREEZES WILL ENHANCE SURFACE CONVERGENCE...WITH THE BEST CHANCE
FOR THUNDERSTORMS SOUTH AND EAST OF BUFFALO ALONG AND EAST OF THE
ERIE LAKE BREEZE. STORMS WILL AGAIN BE SLOW MOVERS...AND WHILE THE
MAJORITY OF THE REGION WILL REMAIN DRY...THUNDERSTORMS WHICH DO
DEVELOP COULD BRING SIGNIFICANT RAINS TO ISOLATED LOCATIONS.
TODAY SHOULD CONTINUE TO BE WARM...WITH HIGHS LIKELY TO CLIMB INTO
THE 80S ACROSS THE REGION...SIMILAR TO PERHAPS A TAD COOLER THAN
YESTERDAY.
THE FORECAST GETS A BIT TRICKIER TONIGHT. MORE MOIST AIR ACROSS THE
OHIO VALLEY WILL BUILD INTO THE REGION TONIGHT. DEW POINTS WILL RISE
INTO THE UPPER 60S TO LOWER 70S...WHICH WILL INCREASE INSTABILITY
EVEN DURING THE NIGHTTIME HOURS. MODEL GUIDANCE IS INCONSISTENT ON
THE DEVELOPMENT OF SHOWERS TONIGHT...WITH SOME MODELS (NAM/RGEM)
FAIRLY BULLISH ON THUNDERSTORMS TONIGHT WHILE OTHERS
(UKMET/EUROPEAN/GFS) TENDING TO SHOW LESS ACTIVITY OR KEEP IT TO THE
SOUTH. WITH NO WELL DEFINED BOUNDARY...EXPECT ANY ACTIVITY TO BE
SCATTERED IN NATURE...AND LIKELY TO COME WITH OR AFTER THE MOIST
AIRMASS BUILDS IN. THERE IS A SLIGHTLY GREATER CHANCE FOR SHOWERS
AND THUNDERSTORMS IN THE SOUTHERN TIER...BUT SEE A CHANCE AT ANY
LOCATION LATE TONIGHT AS THE MOIST AIR MOVES INTO THE BOUNDARY LAYER.
WARMER DEW POINTS SHOULD KEEP TEMPERATURES FROM DROPPING TOO MUCH
TONIGHT...WITH OVERNIGHT LOWS LIKELY TO BE IN THE UPPER 60S AND
LOWER 70S. ALSO EXPECT FOG TO BE A BIT MORE WIDESPREAD...ESPECIALLY
IF SKIES CLEAR OUT AT ALL.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
ON SUNDAY...THE SHORT TERM GUIDANCE IS IN FAIR AGREEMENT THAT AN
INITIAL WEAK SHORTWAVE TROUGH DRAPED FROM THE FINGER LAKES EASTWARD
INTO CENTRAL/EASTERN NEW YORK WILL SLIDE EAST OF THE AREA DURING THE
COURSE OF SUNDAY MORNING...WITH ITS ASSOCIATED SWATH OF DEEPER
MOISTURE/POSSIBLE CONVECTION ALSO GETTING DRAGGED OFF INTO EASTERN
NEW YORK. "POSSIBLE" IS THE KEY WORD HERE WITH RESPECT TO THE
CONVECTIVE POTENTIAL ASSOCIATED WITH THIS INITIAL WAVE...AS THE
VARIOUS GUIDANCE PACKAGES EXHIBIT CONSIDERABLE DISAGREEMENT AS TO
THE EXTENT OF THE AVAILABLE LIFT/MOISTURE AND RESULTANT CONVECTION.
IN ONE CAMP ARE THE NAM AND GFS...WHICH ARE A BIT MORE ROBUST AND
SHOW AT LEAST SOME SCATTERED CONVECTION ACROSS PORTIONS OF THE
FINGER LAKES AND NORTH COUNTRY...WHILE THE ECMWF AND GEM ARE BOTH
NOTABLY WEAKER AND ACTUALLY GENERATE LITTLE IF ANY CONVECTION.
BEHIND THIS INITIAL WAVE...CLOUD COVER WILL LIKELY THIN OUT AT LEAST
ENOUGH TO ALLOW FOR SOME PARTIAL SUNSHINE BY LATE MORNING/EARLY
AFTERNOON AS THE DEEPER MOISTURE SLIDES OFF TO OUR EAST...ALLOWING
FOR DECENT HEATING OF A VERY WARM AND HUMID AIRMASS...AND IN TURN
LEADING TO INCREASING AMOUNTS OF DIURNAL INSTABILITY. AT THE SAME
TIME...THE MAIN AXIS OF THE LARGE-SCALE UPPER TROUGH WILL BE SLIDING
EAST FROM THE CENTRAL GREAT LAKES...AND THIS ALONG WITH POTENTIAL
LAKE BREEZE BOUNDARIES SHOULD HELP TO TRIGGER A ROUND OF MORE
GENERAL SCATTERED CONVECTION DURING THE AFTERNOON.
WITH ALL OF THE ABOVE FACTORS IN MIND...HAVE ELECTED TO CUT BACK ON
SUNDAY`S POPS FROM OUR EXISTING CONTINUITY...LOWERING THESE FROM LOW
LIKELY BACK TO THE CHANCE RANGE. MORE SPECIFICALLY...FOR SUNDAY
MORNING HAVE INDICATED HIGH CHANCE POPS ACROSS OUR EASTERN ZONES IN
ASSOCIATION WITH THE INITIAL DEPARTING WAVE AND ASSOCIATED SLUG OF
DEEPER MOISTURE...WHILE PLACING PROGRESSIVELY LOWER PRECIP CHANCES
FURTHER TO THE WEST. AFTER THAT...HAVE TRANSITIONED TO MORE OF A
BROADBRUSH MID-CHANCE RANGE POP FOR THE AFTERNOON DUE TO THE
APPROACHING UPPER TROUGH AXIS AND INCREASING DAYTIME INSTABILITY.
AS FOR TEMPS...EXPECT VERY WARM AND HUMID CONDITIONS TO CONTINUE...
WITH WIDESPREAD HIGHS IN THE MID-UPPER 80S COUPLED WITH DEWPOINTS
IN THE UPPER 60S.
SUNDAY NIGHT...ANY LINGERING DIURNALLY-DRIVEN CONVECTION SHOULD TEND
TO SLOWLY FADE OUT FROM WEST TO EAST WITH THE LOSS OF DAYTIME
HEATING AND THE DEPARTURE OF THE AFOREMENTIONED TROUGH AXIS...WHICH
WILL GIVE WAY TO BROAD/FLAT SHORTWAVE RIDGING. ACCORDINGLY...HAVE
INDICATED PRECIP CHANCES FALLING BACK THROUGH THE CHANCE RANGE AND
EVENTUALLY TO SLIGHT CHANCE DURING THE OVERNIGHT HOURS...WITH MUCH
OF THE SECOND HALF OF THE NIGHT LIKELY TO BE LARGELY RAIN FREE.
SULTRY CONDITIONS WILL CONTINUE THOUGH...WITH OVERNIGHT LOWS RANGING
FROM THE MID 60S IN THE INTERIOR OF THE SOUTHERN TIER AND NORTH
COUNTRY...TO THE LOWER 70S ACROSS THE LAKE PLAINS.
THEREAFTER...THE REMAINDER OF THE SHORT TERM PERIOD SHOULD LARGELY
FEATURE A CONTINUATION OF UNCOMFORTABLY WARM TO HOT AND HUMID
TEMPERATURES ALONG WITH LARGELY DRY CONDITIONS...AS OUR AREA WILL
REMAIN UNDER THE INFLUENCE OF A BROAD/FLAT UPPER RIDGE OUT AHEAD OF
A COLD FRONT SLOWLY SAGGING SOUTHWARD FROM CENTRAL ONTARIO PROVINCE.
THIS RIDGE SHOULD PROVIDE ENOUGH OF A CAP TO PRECLUDE MUCH MORE THAN
SOME ISOLATED DIURNAL CONVECTION ACROSS THE BULK OF THE AREA BOTH
DAYS...THOUGH SLIGHTLY HIGHER CHANCES FOR CONVECTION COULD REACH THE
SAINT LAWRENCE VALLEY AND NORTH COUNTRY LATER TUESDAY AFTERNOON IF
THE CURRENT GFS/ECMWF TIMING OF THE FRONT DOES INDEED COME TO
FRUITION.
IN TERMS OF TEMPERATURES...850 MB TEMPS OF AROUND +17C MONDAY WILL
CLIMB TO AS HIGH AS +18C/+19C TUESDAY...WHICH SHOULD BE ENOUGH TO
SUPPORT FAIRLY WIDESPREAD HIGHS IN THE UPPER 80S TO LOWER 90S
MONDAY...AND LIKELY EVEN A FEW DEGREES HIGHER THAN THAT ON TUESDAY.
IN BETWEEN WILL BE ANOTHER SULTRY NIGHT MONDAY NIGHT...WHEN LOWS
WILL AGAIN MAINLY RANGE FROM THE MID 60S TO LOWER 70S. THROUGHOUT
THIS TIME...DEWPOINTS WILL REMAIN AT UNCOMFORTABLE LEVELS IN THE MID
TO UPPER 60S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
THE GFS AND ECMWF ARE IN DECENT AGREEMENT IN SHOWING THE COLD FRONT
CROSSING THE FORECAST AREA SOMETIME BETWEEN TUESDAY NIGHT AND
WEDNESDAY...WITH CANADIAN HIGH PRESSURE THEN BUILDING ACROSS THE
GREAT LAKES DURING THE REMAINDER OF THE PERIOD ALONG WITH A RETURN
TO COOLER/DRIER WEATHER. GIVEN SOME CONTINUED DIFFERENCES IN THE
EXACT TIMING OF THE FRONT...WILL CARRY BROADBRUSH SHOWER AND
THUNDERSTORM CHANCES TUESDAY NIGHT AND WEDNESDAY...WITH DRY WEATHER
THEN INDICATED FOR THE REMAINDER OF THE WORK WEEK.
TEMPERATURE-WISE...WILL HAVE VERY WARM AND HUMID CONDITIONS
CONTINUING INTO TUESDAY NIGHT IN ADVANCE OF THE APPROACHING
FRONT...WITH READINGS THEN SETTLING BACK TO AT LEAST MORE SEASONABLE
LEVELS FOR THE BALANCE OF THE WEEK...ALONG WITH MUCH MORE
COMFORTABLE HUMIDITY TO BOOT. IN FACT...IF THE LATEST GFS/ECMWF
DEPICTION OF 850 MB TEMPS OF +8C TO +10C FOR THURSDAY AND FRIDAY
TURNS OUT TO BE CORRECT...TEMPS THEN COULD EVEN BE A BIT COOLER THAN
PRESENTLY INDICATED.
&&
.AVIATION /17Z SATURDAY THROUGH WEDNESDAY/...
LOW LEVEL MOISTURE CONTINUES TO SPREAD NORTH ACROSS THE SOUTHERN
TIER THIS AFTERNOON WITH A DECK OF STRATOCUMULUS AT ABOUT 3500FT.
THIS WILL CONTINUE TO SPREAD NORTH AND COMBINE WITH DAYTIME HEATING
TO PRODUCE DIURNAL CUMULUS FIELDS ACROSS MOST OF THE REGION WITH VFR
PREVAILING. THERE WILL BE A FEW ISOLATED SHOWERS AND STORMS
DEVELOPING FOR A FEW HOURS DURING THE LATE AFTERNOON AND EARLY
EVENING...WITH MOST OF THIS CONFINED TO THE INTERIOR SOUTHERN TIER
AND WESTERN FINGER LAKES REGION. GIVEN VERY SPARSE COVERAGE AND
EXPECTATION THAT STABLE LAKE SHADOWS WILL PROTECT MOST OF THE TAF
SITES...WILL NOT INCLUDE ANY MENTION AT THIS TIME.
TONIGHT LOW LEVEL MOISTURE WILL CONTINUE TO SLOWLY SPREAD
NORTH...AND THIS WILL LIKELY PRODUCE AREAS OF MVFR CIGS OVERNIGHT
ACROSS THE HIGHER TERRAIN OF THE SOUTHERN TIER. A WEAK MID LEVEL
DISTURBANCE WILL COMBINE WITH THE MOISTURE TO PRODUCE A CLUSTER OF
SHOWERS AND EMBEDDED STORMS LIFTING FROM SOUTHWEST TO NORTHEAST
ACROSS THE AREA IN THE 08Z-15Z TIME FRAME. IT APPEARS THE BEST
COVERAGE OF RAIN WILL BE FOUND FROM THE INTERIOR SOUTHERN TIER INTO
THE FINGER LAKES GIVEN RECENT MODEL TRENDS. FOLLOWING THIS INITIAL
BATCH OF MORNING CONVECTION EXPECT ADDITIONAL SCATTERED STORMS TO
DEVELOP WITH DAYTIME HEATING AND THE APPROACH OF ANOTHER MID LEVEL
TROUGH. ANY STORM WILL PRODUCE BRIEFLY HEAVY RAIN AND LOCAL MVFR/IFR
CONDITIONS...BUT VFR WILL STILL PREVAIL MOST OF THE TIME ON SUNDAY
BETWEEN CONVECTIVE ROUNDS.
OUTLOOK...
MONDAY AND TUESDAY...MAINLY VFR.
TUESDAY NIGHT...AREAS OF MVFR IN SCATTERED -SHRA/-TSRA.
WEDNESDAY...BECOMING VFR.
THURSDAY...VFR.
&&
.MARINE...
HIGH PRESSURE OVER PA WILL MOVE TO THE EAST COAST TODAY...WITH A
WEAK TROUGH MOVING IN ON SUNDAY. SCATTERED CONVECTION MAY DEVELOP
WITH TROUGH...PRIMARILY SATURDAY NIGHT AND/OR SUNDAY. WINDS AND
WAVES WILL OTHERWISE REMAIN GENERALLY LIGHT WITH LOCAL LAKE BREEZE
CIRCULATIONS TODAY. A SOUTHWESTERLY FLOW WILL PREVAIL ON SUNDAY BUT
WITH SUB-SMALL CRAFT CONDITIONS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL/HITCHCOCK
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...HITCHCOCK
MARINE...APFFEL/JJR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
603 PM EDT SAT JUL 14 2012
.SYNOPSIS...
AN APPROACHING WARM FRONT WILL BRING INCREASINGLY MOIST AND
UNSETTLED CONDITIONS TO THE REGION FOR THE REMAINDER OF THE
WEEKEND. WARM AND HUMID WEATHER WILL CONTINUE THROUGH MIDWEEK
BEFORE A COLD FRONT BRINGS DRIER AND A MORE COMFORTABLE AIRMASS
FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
CLOUDS APPEAR TO BE DIMINISHING A BIT OVER THE REGION...BUT THERE
IS A GOOD MIX OF LOW...MID...AND HIGH CLOUDS SO CENTRAL AREAS WILL
JUST SEE PEEKS OF SUN. MOSTLY SUNNY IN THE NORTHEASTERN AREAS AND
A BIT OF A CLEAR SLOT MOVING INTO THE WEST.
RADAR SHOWS SHOWER ACTIVITY ON THE WANE. ONLY TWO SHOWERS OF NOTE
WELL TO OUR WEST. SO...LOWERED THE POPS THIS EVENING AND EARLY
TONIGHT. ADDITIONALLY THE HRRR AND 4KM NAM SHOW SOME MAINLY RANDOM
SHOWERS. THE 15Z SREF POPS ARE LOWER THAN THE 0900 UTC RUN.
LOWERED THE POPS...BEST CHANCE IN WEST OVERNIGHT BASED ON SREF
POPS AND ALL THE LIGHTNING ON THE SATELLITE IMAGERY OVER NORTHERN
KY AND SOUTHERN OH. SOME OF THAT COULD BRING MORE CLOUDS AND RAIN
TO SOUTHWESTERN AREAS OVERNIGHT. ANY STORMS THAT DEVELOP COULD
EASILY PRODUCE 1-2 INCHES OF QPF. SREF SHOWS AREAS OF 30 PERCENT
CHANCE OF 1 OR MORE INCHES. PW IS 45 T0 50 MM SO 1-2 INCHES SEEMS
REASONABLE. HIGHEST PROBABILITY WOULD BE IN WESTERN THIRD OF PA
OVERNIGHT. WOULD NOT KNOW IS WHERE UNTIL THE STORM/SHOWERS
APPEARED ON RADAR.
A BIT WARMER OVERNIGHT TONIGHT THAN LAST NIGHT TOO.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
THE 15Z SREF WAS CAUSE TO LOWER POPS A BIT ON SUNDAY BUT STILL ALL
SIGNALS POINT TO BEST CHANCE SHOWERS AND THUNDERSTORMS WOULD BE
SUNDAY. THE HIGHER PW AIR IS PUSHING EAST SUNDAY SO THE WETTER
SUSPECTS WOULD BE IN THE EAST. THE GOOD NEWS IS MOST AREAS ARE IN
THE 50 TO 70 POPS RANGE IN MOST GUIDANCE AND DRIER AIR IS MOVING
IN. THE WEATHER IN THE WEST COULD IMPROVE LATE IN THE AFTERNOON
AND EVENING SUNDAY. DRY AIR IS GOING TO END OUR (BY SUNDAY
AFTERNOON) 3 DAY MOSTLY CLOUDY HUMID PERIOD.
PREVIOUS DISCUSSION HITS MOST OF THE POINTS :
BASICALLY ALL THE GUIDANCE POINTS TO A NEAR CERTAINTY OF SEEING
MEASURABLE RAIN OVER MOST OF THE REGION TOMORROW...ESPECIALLY IN
THE AFTERNOON. MUCH NEEDED RAINFALL SHOULD AMOUNT TO BASIN AVERAGE
AMOUNTS IN THE 0.25-0.50 RANGE ACROSS MUCH OF CENTRAL PENN. THE
LIKELIHOOD OF LOCALIZED 1-2 INCH AMOUNTS EXISTS IN AREAS IMPACTED
BY REPEAT SHOWERS/STORMS SUNDAY AFTERNOON AND EVENING.
MAX TEMPS SUNDAY WILL BE HIGHLY DEPENDENT ON THE AMOUNT OF
INSOLATION WE CAN GET THROUGH THE RATHER EXPANSIVE LAYERED MID
CLOUD DECK. FCST HIGHS CURRENTLY RANGE FROM AROUND 80F ACROSS THE
MTNS...TO A STEAMY 90 DEGREES ACROSS THE LOWER SUSQ VALLEY REGION.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
A WEAK TROF IN THE GENERALLY WESTERLY FLOW WILL BE EXITING TO THE
EAST AT THE START OF THE PERIOD. A RISE IN HEIGHTS BEHIND THE TROF
WILL BE SHORT LIVED AS A NORTHERN STREAM UPPER TROF/LOW CENTER IS
FORECAST TO COME TO A HALT OVER NORTHERN QUEBEC BY MID WEEK. THIS
WILL LEAD TO STEADILY FALLING HEIGHTS OVER THE NEW ENGLAND AND THE
MID ATLANTIC STATES....AND THE PASSAGE OF A COLD FRONT AROUND MID
WEEK. AHEAD OF THE FRONT ANOTHER HOT SPELL LOOKS IN THE OFFING
WITH A DISTINCT COOLING OFF/DRYING OUT PERIOD LATE IN THE WEEK
BEHIND THE FRONT.
MINS AT DAYBREAK MONDAY WILL BE ABOVE NORMAL...VARYING FROM THE
LOWER TO MID 60S ACROSS THE MTNS...TO UPPER 60S TO AROUND 70
DEGREES ELSEWHERE.
FOR MONDAY...A SFC RIDGE OF HIGH PRESSURE EXTENDING NE ALONG THE
APPALACHIANS...AND FLAT RIDGING SLIDING SOUTHEAST ALOFT WILL SUPPLY
US WITH A PARTLY TO MOSTLY SUNNY...HOT AND HUMID MONDAY. LATER
SHIFTS WILL NEED TO KEEP AN EYE ON POTENTIAL HEAT INDICES CLIMBING
TO AROUND 100-102 IN THE LOWER SUSQ VALLEY SHOULD TEMPS AND SFC
DEWPOINTS TURN OUT TO BE ANOTHER FEW DEGREES HIGHER. CURRENTLY...
HEAT INDICES IN THAT AREA ARE FORECAST TO BE IN THE LOW-MID 90S.
ISOLATED TO SCTD AFTERNOON AN EVENING TSRA ARE POSSIBLE ALONG THE
LEE TROUGH THAT SHOULD RESIDE ACROSS OUR FAR SERN ZONES MONDAY.
MINIMAL CHANCES FOR RAIN CONTINUE FOR MOST OF THE CENTRAL AND
EASTERN PORTIONS OF THE CWA ON TUESDAY...AS A MID LEVEL THERMAL
RIDGE CRESTING THE AREA HELPS TO CAP OFF THE MAJORITY OF CONVECTION.
THE PEAK IN THE UPCOMING...SHORT-LIVED HEAT WAVE WILL BE TUESDAY
WHEN 850 TEMPS VIA THE 00Z GEFS CLIMB TO AROUND PLUS 2 ST DEVIATIONS
OR 20-22C. THIS WILL TRANSLATE INTO MAX TEMPS IN THE U80S ACROSS THE
HIGHER TERRAIN OF THE NORTH AND WEST...AND LOWER TO MID 90S
THROUGHOUT THE CENTRAL AND SE VALLEYS.
DEEP LAYER...WEST TO NWRLY SHEAR INCREASES WEDNESDAY AS A POTENT
UPPER TROUGH AND SFC COLD FRONT PUSHES SE FROM THE GLAKES REGION.
A ROUND OR TWO OF GUSTY TSRA IS POSSIBLE WITH THIS FRONTAL
PASSAGE.
TO CLOSE OUT THE WEEK...A REFRESHINGLY DRIER AND RELATIVELY COOLER
AIRMASS WILL OVERSPREAD THE STATE AS A DEEP UPPER LOW SLIDES ACROSS
EASTERN CANADA WITH STRONG NW FLOW ALOFT OVER THE GREAT LAKES AND
NERN U.S.. DRY DEWPOINTS IN THE U40S TO 50S WILL SUPPORT COOL
COMFORTABLE NIGHTS WEDNESDAY NIGHT THROUGH FRIDAY NIGHT.
&&
.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
ISOLATED SHOWERS AND THUNDERSTORMS SW OF SOMERSET...SW OF
JST. SOME OF THIS ACTIVITY MAY BRUSH AOO AND PERHAPS JST.
DEWPOINTS NOT REAL HIGH...SO VISIBILITIES VFR...BUT CIGS
IN SOME SPOTS ARE MVFR. 21Z TAFS ADJUSTED.
EARLIER DISCUSSION BELOW.
TERMINALS OVER THE SRN PART OF THE FCST AREA CONTINUE
TO STRUGGLE WITH CEILINGS IN THE 1000-3000 FOOT RANGE...WITH THE
ELEVATED JST COMING IN EVEN LOWER...JUST BELOW 1000`. VISIBILITIES
ARE GENERALLY NOT A PROBLEM OUTSIDE OF SOME PATCHY THIN HAZE AND
SCATTERED SHOWER ACTIVITY.
AS MOISTURE CONTINUES TO ADVECT INTO THE REGION...EXPECT CEILINGS
TO HANG IN THE 2500-5000` RANGE FOR THE MOST PART WITH LOWER
CONDITIONS POSSIBLE IN PASSING SHOWERS AND ISOLATED THUNDERSTORMS.
THIS SHOULD CONTINUE INTO THE OVERNIGHT WHEN CEILINGS COULD EVEN
DETERIORATE DOWN CLOSER TO IFR LEVELS.
SUNDAY WILL START OFF WITH IFR/MVFR CONDITIONS SLOWLY IMPROVING
WITH DAYTIME HEATING. EXPECT ALL SITES TO BE VFR BY LATE
MORNING...WITH THE EXCEPTION OF SOME HAZE AND SHOWERS/STORMS THAT
COULD LIMIT VIZ TO THE 3-6 MILE RANGE INTO THE AFTERNOON.
OUTLOOK...
MON...MAINLY VFR BUT WITH ISOLATED SHOWERS/STORMS PSBL.
TUE...VFR/NO SIG WX.
WED...SCT TSTM IMPACTS PSBL.
THU...ISOLATED SHWR PSBL ACROSS S PA EARLY...
OTHERWISE VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...GRUMM/LA CORTE
SHORT TERM...GRUMM/LA CORTE
LONG TERM...LAMBERT/GARTNER
AVIATION...LA CORTE/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
429 PM EDT SAT JUL 14 2012
.SYNOPSIS...
AN APPROACHING WARM FRONT WILL BRING INCREASINGLY MOIST AND
UNSETTLED CONDITIONS TO THE REGION FOR THE REMAINDER OF THE
WEEKEND. WARM AND HUMID WEATHER WILL CONTINUE THROUGH MIDWEEK
BEFORE A COLD FRONT BRINGS DRIER AND A MORE COMFORTABLE AIRMASS
FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING.
CLOUDS APPEAR TO BE DIMINISHING A BIT OVER THE REGION...BUT THERE
IS A GOOD MIX OF LOW...MID...AND HIGH CLOUDS SO CENTRAL AREAS WILL
JUST SEE PEEKS OF SUN. MOSTLY SUNNY IN THE NORTHEASTERN AREAS AND
A BIT OF A CLEAR SLOT MOVING INTO THE WEST.
RADAR SHOWS SHOWER ACTIVITY ON THE WANE. ONLY TWO SHOWERS OF NOTE
WELL TO OUR WEST. SO...LOWERED THE POPS THIS EVENING AND EARLY
TONIGHT. ADDITIONALLY THE HRRR AND 4KM NAM SHOW SOME MAINLY RANDOM
SHOWERS. THE 15Z SREF POPS ARE LOWER THAN THE 0900 UTC RUN.
LOWERED THE POPS...BEST CHANCE IN WEST OVERNIGHT BASED ON SREF
POPS AND ALL THE LIGHTNING ON THE SATELLITE IMAGERY OVER NORTHERN
KY AND SOUTHERN OH. SOME OF THAT COULD BRING MORE CLOUDS AND RAIN
TO SOUTHWESTERN AREAS OVERNIGHT. ANY STORMS THAT DEVELOP COULD
EASILY PRODUCE 1-2 INCHES OF QPF. SREF SHOWS AREAS OF 30 PERCENT
CHANCE OF 1 OR MORE INCHES. PW IS 45 T0 50 MM SO 1-2 INCHES SEEMS
REASONABLE. HIGHEST PROBABILITY WOULD BE IN WESTERN THIRD OF PA
OVERNIGHT. WOULD NOT KNOW IS WHERE UNTIL THE STORM/SHOWERS
APPEARED ON RADAR.
A BIT WARMER OVERNIGHT TONIGHT THAN LAST NIGHT TOO.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
THE 15Z SREF WAS CAUSE TO LOWER POPS A BIT ON SUNDAY BUT STILL ALL
SIGNALS POINT TO BEST CHANCE SHOWERS AND THUNDERSTORMS WOULD BE
SUNDAY. THE HIGHER PW AIR IS PUSHING EAST SUNDAY SO THE WETTER
SUSPECTS WOULD BE IN THE EAST. THE GOOD NEWS IS MOST AREAS ARE IN
THE 50 TO 70 POPS RANGE IN MOST GUIDANCE AND DRIER AIR IS MOVING
IN. THE WEATHER IN THE WEST COULD IMPROVE LATE IN THE AFTERNOON
AND EVENING SUNDAY. DRY AIR IS GOING TO END OUR (BY SUNDAY AFTERNOON) 3 DAY
MOSTLY CLOUDY HUMID PERIOD.
PREVIOUS DISCUSSION HITS MOST OF THE POINTS :
BASICALLY ALL THE GUIDANCE POINTS TO A NEAR CERTAINTY OF SEEING
MEASURABLE RAIN OVER MOST OF THE REGION TOMORROW...ESPECIALLY IN
THE AFTERNOON. MUCH NEEDED RAINFALL SHOULD AMOUNT TO BASIN AVERAGE
AMOUNTS IN THE 0.25-0.50 RANGE ACROSS MUCH OF CENTRAL PENN. THE
LIKELIHOOD OF LOCALIZED 1-2 INCH AMOUNTS EXISTS IN AREAS IMPACTED
BY REPEAT SHOWERS/STORMS SUNDAY AFTERNOON AND EVENING.
MAX TEMPS SUNDAY WILL BE HIGHLY DEPENDENT ON THE AMOUNT OF
INSOLATION WE CAN GET THROUGH THE RATHER EXPANSIVE LAYERED MID CLOUD
DECK. FCST HIGHS CURRENTLY RANGE FROM AROUND 80F ACROSS THE
MTNS...TO A STEAMY 90 DEGREES ACROSS THE LOWER SUSQ VALLEY REGION.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
A WEAK TROF IN THE GENERALLY WESTERLY FLOW WILL BE EXITING TO THE
EAST AT THE START OF THE PERIOD. A RISE IN HEIGHTS BEHIND THE TROF
WILL BE SHORT LIVED AS A NORTHERN STREAM UPPER TROF/LOW CENTER IS
FORECAST TO COME TO A HALT OVER NORTHERN QUEBEC BY MID WEEK. THIS
WILL LEAD TO STEADILY FALLING HEIGHTS OVER THE NEW ENGLAND AND THE
MID ATLANTIC STATES....AND THE PASSAGE OF A COLD FRONT AROUND MID
WEEK. AHEAD OF THE FRONT ANOTHER HOT SPELL LOOKS IN THE OFFING
WITH A DISTINCT COOLING OFF/DRYING OUT PERIOD LATE IN THE WEEK
BEHIND THE FRONT.
MINS AT DAYBREAK MONDAY WILL BE ABOVE NORMAL...VARYING FROM THE
LOWER TO MID 60S ACROSS THE MTNS...TO UPPER 60S TO AROUND 70
DEGREES ELSEWHERE.
FOR MONDAY...A SFC RIDGE OF HIGH PRESSURE EXTENDING NE ALONG THE
APPALACHIANS...AND FLAT RIDGING SLIDING SOUTHEAST ALOFT WILL SUPPLY
US WITH A PARTLY TO MOSTLY SUNNY...HOT AND HUMID MONDAY. LATER
SHIFTS WILL NEED TO KEEP AN EYE ON POTENTIAL HEAT INDICES CLIMBING
TO AROUND 100-102 IN THE LOWER SUSQ VALLEY SHOULD TEMPS AND SFC
DEWPOINTS TURN OUT TO BE ANOTHER FEW DEGREES HIGHER. CURRENTLY...
HEAT INDICES IN THAT AREA ARE FORECAST TO BE IN THE LOW-MID 90S.
ISOLATED TO SCTD AFTERNOON AN EVENING TSRA ARE POSSIBLE ALONG THE
LEE TROUGH THAT SHOULD RESIDE ACROSS OUR FAR SERN ZONES MONDAY.
MINIMAL CHANCES FOR RAIN CONTINUE FOR MOST OF THE CENTRAL AND
EASTERN PORTIONS OF THE CWA ON TUESDAY...AS A MID LEVEL THERMAL
RIDGE CRESTING THE AREA HELPS TO CAP OFF THE MAJORITY OF CONVECTION.
THE PEAK IN THE UPCOMING...SHORT-LIVED HEAT WAVE WILL BE TUESDAY
WHEN 850 TEMPS VIA THE 00Z GEFS CLIMB TO AROUND PLUS 2 ST DEVIATIONS
OR 20-22C. THIS WILL TRANSLATE INTO MAX TEMPS IN THE U80S ACROSS THE
HIGHER TERRAIN OF THE NORTH AND WEST...AND LOWER TO MID 90S
THROUGHOUT THE CENTRAL AND SE VALLEYS.
DEEP LAYER...WEST TO NWRLY SHEAR INCREASES WEDNESDAY AS A POTENT
UPPER TROUGH AND SFC COLD FRONT PUSHES SE FROM THE GLAKES REGION. A
ROUND OR TWO OF GUSTY TSRA IS POSSIBLE WITH THIS FRONTAL PASSAGE.
TO CLOSE OUT THE WEEK...A REFRESHINGLY DRIER AND RELATIVELY COOLER
AIRMASS WILL OVERSPREAD THE STATE AS A DEEP UPPER LOW SLIDES ACROSS
EASTERN CANADA WITH STRONG NW FLOW ALOFT OVER THE GREAT LAKES AND
NERN U.S.. DRY DEWPOINTS IN THE U40S TO 50S WILL SUPPORT COOL
COMFORTABLE NIGHTS WEDNESDAY NIGHT THROUGH FRIDAY NIGHT.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
TERMINALS OVER THE SRN PART OF THE FCST AREA CONTINUE TO STRUGGLE
WITH CEILINGS IN THE 1000-3000 FOOT RANGE...WITH THE ELEVATED JST
COMING IN EVEN LOWER...JUST BELOW 1000`. VISIBILITIES ARE
GENERALLY NOT A PROBLEM OUTSIDE OF SOME PATCHY THIN HAZE AND
SCATTERED SHOWER ACTIVITY.
AS MOISTURE CONTINUES TO ADVECT INTO THE REGION...EXPECT CEILINGS
TO HANG IN THE 2500-5000` RANGE FOR THE MOST PART WITH LOWER
CONDITIONS POSSIBLE IN PASSING SHOWERS AND ISOLATED THUNDERSTORMS.
THIS SHOULD CONTINUE INTO THE OVERNIGHT WHEN CEILINGS COULD EVEN
DETERIORATE DOWN CLOSER TO IFR LEVELS.
SUNDAY WILL START OFF WITH IFR/MVFR CONDITIONS SLOWLY IMPROVING
WITH DAYTIME HEATING. EXPECT ALL SITES TO BE VFR BY LATE
MORNING...WITH THE EXCEPTION OF SOME HAZE AND SHOWERS/STORMS THAT
COULD LIMIT VIZ TO THE 3-6 MILE RANGE INTO THE AFTERNOON.
OUTLOOK...
MON...MAINLY VFR BUT WITH ISOLATED SHOWERS/STORMS PSBL.
TUE...VFR/NO SIG WX.
WED...SCT TSTM IMPACTS PSBL.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...GRUMM/LA CORTE
SHORT TERM...GRUMM/LA CORTE
LONG TERM...LAMBERT/GARTNER
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
339 PM CDT SAT JUL 14 2012
.DISCUSSION...
.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT.
HEAVY SHOWERS AND THUNDERSTORMS CONTINUE THIS AFTERNOON...MAINLY
EAST OF I-55. A STRANGE AREA OF SUBSIDENCE HAS EVOLVED OVER EAST
CENTRAL ARKANSAS WITH MOSTLY CLEAR SKIES. THINK THIS WILL FILL
BACK IN WITH TIME WITH THE STORMS OVER WRN AND NRN AR PROPAGATING
SOUTHWARD. SOME CU IS NOW REDEVELOPING OVER THIS AREA.
THUNDERSTORMS WILL BE MOST NUMEROUS TONIGHT AND SUNDAY ALONG THE
SHEAR AXIS EXTENDING FROM EAST TEXAS THOUGH ARKANSAS AND NORTHEAST
INTO THE OHIO VALLEY. HEAVY RAINFALL IS POSSIBLE GIVEN OBSERVED
PW VALUES OF 2.1 AND 2.17 INCHES AT LITTLE ROCK AND NASHVILLE...
RESPECTIVELY...WHICH MAY INCREASE TOWARD 2.25 INCHES ON SUNDAY.
GIVEN THE OVERALL DISORGANIZED NATURE OF THIS ACTIVITY...IT IS
HARD TO PULL THE TRIGGER ON A FLASH FLOOD WATCH.
KEPT TEMPERATURES ON THE WARMEST SIDE OF GUIDANCE TONIGHT AND
SUNDAY NIGHT WITH HIGHS ON THE COOLER SIDE SUNDAY WITH THE CLOUDS
AND RAINFALL.
.LONG TERM...MONDAY THROUGH SATURDAY.
THE BLISTERING HEAT WAVE WILL RETURN TO THE MIDWEST NEXT WEEK AS
HEIGHTS INCREASE OVER THE CENTER OF THE NATION. THE MIDSOUTH WILL
REMAIN IN AN EASTERLY MID LEVEL FLOW ON THE SOUTHEASTERN EDGE OF
THIS RIDGE SO THUNDERSTORMS ARE EXPECTED TO CONTINUE EACH
DAY...ESPECIALLY OVER NORTHEAST MISSISSIPPI. A SOUTHERLY SURFACE
FLOW WILL UNDERCUT THE BUILDING RIDGE WHICH WILL MAKE FOR HOT AND
VERY HUMID CONDITIONS BY THE MIDDLE OF THE WEEK. DEW POINTS IN THE
MID/UPPER 70S ARE POSSIBLE. THAT LEVEL OF HUMIDITY WITH HIGHS
PRESUMABLY IN THE MID 90S WILL BRING HEAT INDICES IN THE 105 TO
110 RANGE.
THE RIDGE MAY RETROGRADE A BIT FOR LATE WEEK WITH MORE OF A
NORTHERLY FLOW TAKING HOLD BY FRIDAY. COOLER AND SLIGHTLY LESS
HUMID CONDITIONS ARE EXPECTED.
BORGHOFF
&&
.AVIATION...
12Z TAF SET
LIGHT RAIN CONTINUES TO DEVELOP MAINLY WEST OF THE MISSISSIPPI
RIVER. THE LATEST HRRR MODEL SHOWS THIS CONTINUING THROUGH 18Z.
KMEM WILL LIKELY BE ON THE EDGE. VSBYS COULD BE REDUCED AT KJBR
AND KMEM FROM ANY HEAVIER SHOWERS THAT OCCUR. AFTER 16Z...THE HRRR
WHICH SEEMS TO HAVE BEST HANDLE OF WHAT IS CURRENTLY GOING
ON...INDICATES A LINE OF TSRA DEVELOPING NEAR KMKL SOUTHWARD. HAVE
INTRODUCED A TEMPO GROUP AT KMKL BETWEEN 18Z AND 21Z. NOT AS
CONFIDENT ON ANY OTHER POTENTIAL TSRA DEVELOPMENT TODAY THUS WILL
LEAVE VCTS WORDING AT KMEM FROM 18Z-01Z AND AT KTUP FROM 16Z-01Z.
KJBR WILL LIKELY BE WORKED OVER FROM THIS MORNINGS RAIN THUS
CHANCES OF ANY TSRAS THIS AFTERNOON SEEMS LOW THUS HAVE REMOVED
VCTS WORDING. LIGHT WINDS GENERALLY EXPECTED OVER NEXT 24 HOURS.
KRM
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 75 88 76 94 / 60 60 20 30
MKL 71 86 71 92 / 60 60 30 30
JBR 74 87 75 94 / 50 60 20 20
TUP 73 88 73 93 / 50 60 20 30
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
1126 AM CDT SAT JUL 14 2012
.UPDATE...
SCATTERED TO NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE
LATE THIS MORNING ACROSS THE MIDSOUTH. A LOW PRESSURE CENTER NEAR
SHREVEPORT LA IS CLEARLY VISIBLE ON SATELLITE. THIS IS ON THE
LOWER END OF A SHEAR AXIS STRETCHING NORTHEAST ACROSS THE
MIDSOUTH. THIS SHEAR AXIS SHOULD CONTINUE TO BE A FOCUS FOR
SHOWER/ISO TSTORM DEVELOPMENT THROUGH THE AFTERNOON AND
POTENTIALLY WELL INTO THE EVENING. INCREASED POPS THIS AFTERNOON
TO NUM-OCNL. REST OF THE GRIDS LOOK FINE.
BORGHOFF
&&
.PREV DISCUSSION... /ISSUED 435 AM CDT SAT JUL 14 2012/
THE UPPER LEVEL SHEAR AXIS THAT HAS BOROUGH UNSETTLED WEATHER TO
THE MIDSOUTH OVER THE PAST SEVERAL DAYS WILL WEAKEN...AS AN UPPER
LEVEL SUBTROPICAL HEIGHT RIDGE BUILDS IN FROM THE SOUTHEAST. THIS
WEAKENING WILL OCCUR THROUGH MONDAY... WITH CHANCES OF SHOWERS AND
THUNDERSTORMS CONTINUING IN THE INTERIM.
THE EARLY TO MIDDLE PORTIONS OF THE UPCOMING WEEK WILL SEE A 590DM
500MB HEIGHT RIDGE OVER THE LOWER MS RIVER VALLEY. THE UPPER RIDGE WILL
SERVE TO SUPPRESS MOST OF NOT ALL NIGHTTIME THUNDERSTORMS. ISOLATED
TO SCATTERED AFTERNOON THUNDERSTORMS WILL REMAIN POSSIBLE...WITH THE
GFS HINTING AT WEAKNESSES IN THE UPPER RIDGE AND 700MB TEMPS ONLY
9C TO 10C. WITH AFTERNOON TEMPS IN THE MID 90S...DEWPOINTS IN THE
LOWER 70S AND WEAK SHEAR...ISOLATED TO SCATTERED PULSE THUNDERSTORMS
WILL BE POSSIBLE DURING THE HEAT OF THE DAY.
FOR THE MID TO LATTER PART OF NEXT WEEK... 00Z GFS AND ECMWF WERE
CONSISTENT IN AMPLIFYING THE UPPER RIDGE OVER THE PLAINS AND ROCKY
MOUNTAINS... WHILE HEIGHT FALLS OVER THE NORTHEAST AND APPALACHIA
RESULT IN WEAK NORTHWEST UPPER LEVEL FLOW OVER THE MIDSOUTH. GIVEN
OUR PROXIMITY TO A SOUTHERN PLAINS UPPER RIDGE CENTER... TEMPS
ACROSS THE MIDSOUTH WILL AVERAGE SEVERAL DEGREES ABOVE NORMAL...
BUT NOT AS HOT AS THE PLAINS WILL LIKELY SEE. WEAK DAYTIME CONVECTIVE
INHIBITION DURING THE LATE WEEK PERIODS WILL LIKELY RESULT IN
CONTINUED CHANCES OF MAINLY AFTERNOON THUNDERSTORMS.
PWB
&&
.AVIATION...
12Z TAF SET
LIGHT RAIN CONTINUES TO DEVELOP MAINLY WEST OF THE MISSISSIPPI
RIVER. THE LATEST HRRR MODEL SHOWS THIS CONTINUING THROUGH 18Z.
KMEM WILL LIKELY BE ON THE EDGE. VSBYS COULD BE REDUCED AT KJBR
AND KMEM FROM ANY HEAVIER SHOWERS THAT OCCUR. AFTER 16Z...THE HRRR
WHICH SEEMS TO HAVE BEST HANDLE OF WHAT IS CURRENTLY GOING
ON...INDICATES A LINE OF TSRA DEVELOPING NEAR KMKL SOUTHWARD. HAVE
INTRODUCED A TEMPO GROUP AT KMKL BETWEEN 18Z AND 21Z. NOT AS
CONFIDENT ON ANY OTHER POTENTIAL TSRA DEVELOPMENT TODAY THUS WILL
LEAVE VCTS WORDING AT KMEM FROM 18Z-01Z AND AT KTUP FROM 16Z-01Z.
KJBR WILL LIKELY BE WORKED OVER FROM THIS MORNINGS RAIN THUS
CHANCES OF ANY TSRAS THIS AFTERNOON SEEMS LOW THUS HAVE REMOVED
VCTS WORDING. LIGHT WINDS GENERALLY EXPECTED OVER NEXT 24 HOURS.
KRM
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 88 74 91 75 / 80 40 50 20
MKL 86 71 91 71 / 80 30 50 20
JBR 85 71 91 72 / 80 40 50 20
TUP 90 73 92 73 / 70 40 40 20
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1217 PM CDT SAT JUL 14 2012
.AVIATION...
SCATTERED SHRA/TSRA DEVELOPING ACROSS THE AREA. 18Z TAFS WILL
CARRY VCSH/VCTS THROUGH THIS AFTERNOON. EXPECT DECREASING COVERAGE
THIS EVENING WITH THE LOSS OF HEATING. WE THEN ANTICIPATE DEVELOPMENT
AGAIN DURING THE OVERNIGHT HOURS...SO HAVE ADDED VCSH STARTING AROUND
09Z-10Z...THEN VCTS FOR LATE TOMORROW MORNING AND INTO TOMORROW AFTERNOON.
MVFR CEILINGS COULD DEVELOP OVERNIGHT TOO. EXPECT TO SEE MVFR/IFR
CEILINGS AND VISIBILITIES IN/NEAR THE SHRA/TSRA. 42
&&
.PREV DISCUSSION... /ISSUED 1042 AM CDT SAT JUL 14 2012/
DISCUSSION...
LOW PRESSURE CAN BE SEEN SPINNING AWAY JUST SOUTH OF SHREVEPORT ON
SATELLITE AND RADAR. WATER VAPOR HIGHLIGHTING THE DIFFERENCE IN
AIRMASS ACROSS THE AREA WITH THE VERY MOIST AIRMASS SOUTH FROM A TXK-
UTS-VCT LINE. 12Z LCH SOUNDING THIS MORNING SHOWING NEARLY 2" PW
AND WITH NO CAP AND CAPE INCREASING TO 2000+ WITH HEATING/K-INDEX
34 OR BETTER EXPECT SCATTERED SHOWERS AND THUNDERSTORMS THIS
MORNING ESPECIALLY ALONG THE COAST AND EASTERN AREAS. AFTERNOON
HEATING SHOULD HELP TO BRING OUT THE SEABREEZE AND HAVE SOME
CONCERNS THAT THE SOUTHWESTERN AREAS WILL HAVE LOCALLY HEAVY
RAINFALL THREAT. HIGHER CAPE AND MODELS INDICATING THE STORM
MOTIONS TO SLOW AND THEN REVERSE. HAVE ADDED LOCALLY HEAVY RAIN
POSSIBLE IN THESE AREAS. DRIER AIR ALOFT MAY HELP TO KEEP THEM
FORWARD MOVING. WESTERN HALF OF THE AREA SHOULD MORE EASILY REACH
THE 89-92 DEGREE RANGE AWAY FROM THE THICKER CLOUD COVER AND
MORNING PRECIP...COOLER SOUTH AND EAST.
IMPROVING CONDITIONS ON MOST OF THE AREA RIVER ISSUES OBVIOUSLY
CONTINUING MOST OF THE RIVERS/CREEKS THAT HAVE BEEN HARDEST HIT
THE LAST COUPLE OF DAYS HAVE CRESTED AND BEGUN SLOW FALLS BUT
DOWNSTREAM LOCATIONS SUCH AS SPRING CREEK AT SPRING AT CREST OR
JUST MAKING THE DOWNWARD TURN. LUCE BAYOU STILL CLIMBING.
SUNDAY...EARLY 12Z GUIDANCE STILL FAVORING SETX WITH MORE
SIGNIFICANT RAINFALL AND MAY HAVE TO HOIST THE FLOOD WATCH AGAIN
FOR SUNDAY. WILL WAIT TO GET A LOOK AT THE REMAINDER OF THE 12Z
GUIDANCE BEFORE DOING SO.
45
PREV DISCUSSION... /ISSUED 413 AM CDT SAT JUL 14 2012/
DISCUSSION...
RADAR IS FAIRLY QUIET THIS MORNING BUT AM EXPECTING SHRA/TSRA TO
INCREASE IN COVERAGE TOWARD DAYBREAK. AT 850 MB...A WEAK AREA OF
LOW PRESSURE WAS NOTED OVER EAST CENTRAL LOUISIANA AND THIS
POSITION IS MUCH FURTHER EAST THAN THE PAST FEW MORNINGS. A WEAK
TROUGH AXIS EXTENDS SOUTH INTO THE NORTHERN GULF OF MEXICO. 850 MB
DEW PTS HAVE DROPPED TO 12-14C BUT PW VALUES REMAIN FAIRLY HIGH
BETWEEN 1.9 AND 2.0 INCHES. AT 250 MB...AN UPPER LEVEL RIDGE WAS
LOCATED OVER THE FOUR CORNERS WITH A SECOND RIDGE OVER GEORGIA.
BETWEEN THE TWO RIDGES IS CYCLONIC SHEAR AXIS THAT EXTENDS FROM
SOUTHERN ILLINOIS TO TEXARKANA TO CORPUS CHRISTI. SOUTHEAST TEXAS
WILL LIE TO THE EAST OF THIS FEATURE TODAY SO AM EXPECTING
SCATTERED SHRA/TSRA. MOISTURE LEVELS ARE STILL RATHER HIGH AND
STORM MOTION IS SLOW SO ANY STORMS THAT DEVELOP WILL HAVE THE
POTENTIAL TO PRODUCE LOCALLY HEAVY RAIN. THAT SAID...FEEL THE
THE HEAVY RAIN THREAT IS LESS THAN THE PAST FEW DAYS AND ATTM DO
NOT FEEL A FLOOD WATCH IS WARRANTED. THE RAP MODEL IS AGGRESSIVE
WITH RAIN CHANCES THIS MORNING WHILE OTHER SHORT TERM MODELS ARE
MORE BENIGN.
THE UPPER LEVEL SHEAR AXIS WILL SLOWLY SHIFT WEST ON SUNDAY. THE
NAM AND ECMWF CONTINUE TO DEVELOP A WEAK 500 MB LOW OR INVERTED
TROUGH. THIS WILL KEEP SOUTHEAST TEXAS IN A FAVORABLE POSITION
FOR ADDITIONAL PCPN. WILL LEAN TOWARD A NAM/ECMWF BLEND FOR
SUNDAY. MON-WED LOOK TO BE FAIRLY TYPICAL FOR SOUTHEAST TEXAS WITH
MAX TEMPS IN THE LOW TO MID 90S AND SHRA/TSRA DEVELOPING ALONG THE
SEA BREEZE. WILL CONTINUE TO 20/30 POPS FOR THE PERIOD. UPPER
LEVEL RIDGING WILL TRY TO BUILD BACK INTO SOUTHEAST TEXAS LATER
NEXT WEEK SO WILL TREND THE SECOND HALF OF NEXT WEEK WARMER AND
DRIER. 43
MARINE...
NO SIGNIFICANT CHANGES TO CURRENT FCST TRENDS. A WEAK SURFACE TROUGH
WILL KEEP LIGHT WINDS IN PLACE THROUGH THE WEEKEND. THE LINGERING
UPPER LEVEL TROF WILL ALSO KEEP SCATTERED STORMS IN THE FCST THROUGH
THE WEEKEND. BRIEF GUSTY WINDS/ELEVATED SEAS ARE POSSIBLE IN AND
NEAR THE STRONGER STORMS. 34
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 91 73 90 73 92 / 40 20 50 20 30
HOUSTON (IAH) 88 74 89 74 91 / 50 20 50 20 30
GALVESTON (GLS) 88 80 88 82 90 / 50 30 50 30 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...45
AVIATION/MARINE...42
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
218 PM EDT SAT JUL 14 2012
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH THROUGH THE REGION THIS MORNING
BEFORE DISSIPATING. HIGH PRESSURE OFFSHORE WILL BUILD INTO THE
REGION LATER THIS WEEKEND BRINGING A RETURN OF MUCH WARMER
WEATHER BY EARLY NEXT WEEK. A COLD FRONT WILL TRY TO MAKE ITS WAY
INTO AND THROUGH THE HIGH BY THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1225 PM EDT SATURDAY...
RADAR INDICATED SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPED IN
THE VIRGINA FOOTHILLS AND PIEDMONT. EXPECT SCATTERED TO NUMEROUS
STORMS SUPPORTED BY THE LOW LEVEL SOUTHWEST FLOW INTO THE
SOUTHERN BLUE RIDGE. SCATTERED THUNDERSTORMS ARE ALSO EXPECTED
OVER SOUTHEAST WEST VIRGINIA MORE ON THE EDGE OF UPPER RIDGE.
MSAS ANALYSIS OF THETA-E VALUES AND THE LIFTED INDEX SHOWS THE
WARM FRONT HAS LIFTED NORTH AND EXTENDED FROM MARYLAND TO SOUTHERN
OHIO. THE WEDGE HAS ERODED. MODIFIED SOUNDINGS FROM RNK AND GSO
SHOWED CAPES THIS AFTERNOON NEAR 3000 J/KG AND DCAPES AROUND 500
J/KG. A FLASH FLOOD WATCH HAS BEEN ISSUED ALONG AND EAST OF THE
BLUE RIDGE.
AS OF 255 AM EDT SATURDAY...
WARM FRONT ACROSS THE CENTRAL CWA THIS MORNING WILL LIFT NORTH AND
BASICALLY DISSIPATE BY AFTERNOON AS A GRADUALLY DEEPENING SOUTH/SW
FLOW DEVELOPS AROUND THE RIDGE OFFSHORE. BEHIND THE FRONT WILL SEE A
CONTINUED INFLUX OF WARMER AND MORE HUMID AIR WHICH PROVIDED ENOUGH
HEATING SHOULD SPARK ANOTHER ROUND OF SHRA/TSRA INTO THIS EVENING.
HOWEVER IN THE WAKE OF THE BOUNDARY...FOCUS LIKELY TIED MORE TO
OROGRAPHICS IN THE WEST AND OLD OUTFLOW IN THE EAST...PRODUCING A
MORE SCATTERED NATURE COVERAGE PER LATEST HRRR AND LOCAL WRF SOLNS.
APPEARS DEVELOPING SW FLOW AND HIGHER THETA-E MOUNTAINS SHOULD
SUPPORT BETTER COVERAGE NEAR THE BLUE RIDGE AND PERHAPS THE NW
WHERE WILL BE CLOSEST TO THE RESIDUAL FRONT. THUS MAY INCLUDE SOME
LOW AFTERNOON LIKELY POPS IN SPOTS ALONG THE RIDGES...WITH MAINLY
CHANCE COVERAGE ELSW WITH SOME OF THIS DEVELOPING LATER THIS
MORNING AS HEATING GETS GOING. LATEST FORECAST SOUNDINGS ALSO SHOW
WEAK MID LEVEL STEERING OF AROUND 10 MPH AND VERY MOIST PWATS OF
1.75 INCHES OR BETTER SO SLOW MOVING HEAVY RAINERS A THREAT
ESPCLY IF THINGS BAND UP ALONG THE RIDGES. DEGREE OF CLOUD COVER
TRICKY BY AFTERNOON WITH GUIDANCE SUGGESTING SOME BREAKS BUT THEN
QUICKLY DEVELOP CONVECTION WHICH MAY CURTAIL TEMP RISES. LATEST
MAV MOS LOOKS TOO WARM GIVEN EARLY CLOUDS AND AFTERNOON SHRA WHILE
THE MET TOO SLOW TO EXIT THE WEAK WEDGE. THUS GOING IN BETWEEN AND
CLOSER TO THE ENSEMBLE HIGHS WHICH PUTS THE WEST IN THE 76-82
RANGE AND MAINLY MID/UPR 80S EAST.
UPPER RIDGE OFFSHORE SHIFTS FARTHER WEST OVERNIGHT PUSHING THE
LINGERING DEEPER MOISTURE AXIS ALONG THE WESTERN SLOPES FARTHER
INLAND. THIS ALONG WITH SLIGHTLY HIGHER 5H HEIGHTS SHOULD END MOST
CONVECTION THIS EVENING ALLOWING FOR MOSTLY CLEAR TO PC SKIES
OVERNIGHT WITH SOME PATCHY FOG AROUND...AND ONLY AN ISOLATED SHRA
THREAT FAR WEST. WILL BE QUITE WARM AND MUGGY WITH LOWS 65-72
UNDER A MOIST AND SOUPY ENVIRONMENT IN THE WAKE OF ANY EARLIER
STORMS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
SEVERAL WEATHER FEATURES WILL CONVERGE OVER THE MID ATLANTIC REGION
AND KEEP THE CHANCES FOR SHOWERS AND THUNDERSTORMS IN THE FORECAST
THROUGH EARLY NEXT WEEK. AN UPPER LEVEL TROUGH OVER THE GREAT LAKES
AND A VORTICITY AXIS IN THE OHIO VALLEY WILL SLOWLY MOVE TO THE EAST
THROUGH THE PERIOD. AN UPPER LEVEL RIDGE...CURRENT OVER THE
REGION...WILL DRIFT TO THE SOUTH ALLOWING THE VORTICITY AXIS TO MOVE
OVER THE MOUNTAINS SUNDAY AND THE UPPER LEVEL TROUGH TO MOVE INTO
THE REGION MONDAY AND TUESDAY. WITH THE ADDITION OF SHORT WAVES
COMING AROUND THE UPPER LEVEL RIDGE AND A SURFACE LEE TROUGH IN THE
PIEDMONT...SCATTERED SHOWERS AND THUNDERSTORMS WILL REMAIN IN THE
FORECAST THROUGH THE PERIOD. WILL KEEP THE HIGHEST POPS DURING PEAK
HEATING AND MAINLY OVER THE MOUNTAINS SUNDAY AND MONDAY. ANY STRONG
STORMS THAT DEVELOP DURING THIS PERIOD WILL MOVE SLOW AND COULD
RESULT IN LOCALIZE FLASH FLOODING.
SCATTERED SHOWERS SHOULD HELP COOL AFTERNOON TEMPERATURES...BUT
UNTIL THEY DO...AFTERNOON TEMPERATURES WILL RUN ABOVE NORMAL BY 5F
TO 10F. IF THESE SHOWERS COOLING THE TEMPERATURES...RELATIVE
HUMIDITY WILL INCREASE...RESULTING IN MUGGY AND UNCOMFORTABLE
CONDITIONS. MOS GUIDANCE TEMPERATURES ARE SIMILAR...THERE I DID NOT
STRAY TO FAR FROM THEM.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 300 PM EDT FRIDAY...
BROAD UPPER RIDGE REMAINS OVER THE SOUTHEAST UNITED STATES. RIDGE
FLATTENS ON THURSDAY AND FRIDAY. SURFACE FRONT DROPS THROUGH SOUTH
INTO THE MID ATLANTIC REGION BY FRIDAY. CHANCE OF SHOWERS AND
THUNDERSTORMS WILL IMPROVE THURSDAY AND FRIDAY AHEAD OF THE FRONT.
OTHERWISE NO DISTINCT FEATURES TO HELP ORGANIZE ANY THUNDERSTORMS
TUESDAY AND WEDNESDAY. HOWEVER...AIR MASS WILL BE WARM AND UNSTABLE
WITH 850 MB TEMPERATURES IN THE +18 TO +20 RANGE. WILL KEEP DAILY
PROBABILITY OF AFTERNOON AND EVENING THUNDERSTORMS IN THROUGH THE
PERIOD. TEMPERATURES WILL REMAIN SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 215 PM EDT SATURDAY...
RADAR SHOWED SCATTERED THUNDERSTORMS BETWEEN DANVILLE AND
LYNCHBURG AND BETWEEN BLUEFIELD AND LEWISBURG THIS AFTERNOON. IT
WILL TAKE FER MORE HOURS FOR STORMS TO REACH BCB AND ROA. MORNING
SOUNDINGS AT RNK AND GSO SHOWED THE POTENTIAL FOR VERY HEAVY RAIN
WITH THE STORMS THIS AFTERNOON AND EVENING. MVFR CEILINGS AND
VISIBILITIES ARE LIKELY. MOST AREAS OUTSIDE THE STORMS WILL
EXPERIENCE VFR CONDITIONS.
LATE NIGHT IFR/MVFR MOUNTAIN AND RIVER VALLEY FOG WILL BE
POSSIBLE. LIFR FOG IS EXPECTED AT LWB...ESPECIALLY IF THEY HAVE
RAIN THIS AFTERNOON.
SUNDAY AND MONDAY...HIGH PRESSURE GRADUALLY BUILDS INTO THE AREA WITH
PROGRESSIVELY MILDER TEMPERATURES AND A STRONG CAPPING INVERSION
ALOFT. CONDITIONS WILL BE MAINLY VFR EXPECT BRIEFLY UNDER THOSE
ISOLATED AREAS THAT RECEIVE A MODERATE TO HEAVY SHOWER OR STORM.
BY THURSDAY...A COLD FRONT APPROACHES THE REGION. THIS WILL RESULT
IN MORE WIDESPREAD SHOWERS AND THUNDERSTORMS.
&&
.HYDROLOGY...
A FLASH FLOOD WATCH HAS BEEN ISSUED ALONG AND EAST OF THE BLUE
RIDGE FOR THIS AFTERNOON AND EVENING. MODIFIED SOUNDINGS FROM RNK
AND GSO SHOWED PRECIPITABLE WATER VALUES OF 1.7 TO 2.0 INCHES
WHICH IS ABOUT 140 PERCENT OF NORMAL. WARM CLOUD DEPTH IS AROUND
20,000 FEET AND STEERING FLOW IS ONLY 5 TO 10 KNOTS SO HEAVY RAIN
IS EXPECTED. FFG IN SOME SPOTS OF THE FOOTHILLS AND PIEDMONT...
ESPECIALLY FROM WILKES COUNTY INTO PITTSYLVANIA COUNTY IS NEAR 2
INCHES. GETTING RATES OF 2 INCHES IN AN HOUR IS POSSIBLE TODAY.
&&
.EQUIPMENT...
NOAA ALL HAZARDS RADIO FOR THE HINTON TRANSMITTER REMAINS OFF THE
AIR DUE TO COMMERCIAL POWER NOT REACHING THE SITE.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR VAZ015>017-
022>024-032>035-043>047-058-059.
NC...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR NCZ001>006-
018>020.
WV...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...AMS/JH
SHORT TERM...RCS
LONG TERM...AMS
AVIATION...AMS/JH
HYDROLOGY...AMS
EQUIPMENT...AMS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1240 PM EDT SAT JUL 14 2012
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH THROUGH THE REGION THIS MORNING
BEFORE DISSIPATING. HIGH PRESSURE OFFSHORE WILL BUILD INTO THE
REGION LATER THIS WEEKEND BRINGING A RETURN OF MUCH WARMER
WEATHER BY EARLY NEXT WEEK. A COLD FRONT WILL TRY TO MAKE ITS WAY
INTO AND THROUGH THE HIGH BY THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1225 PM EDT SATURDAY...
RADAR INDICATED SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPED IN
THE VIRGINA FOOTHILLS AND PIEDMONT. EXPECT SCATTERED TO NUMEROUS
STORMS SUPPORTED BY THE LOW LEVEL SOUTHWEST FLOW INTO THE
SOUTHERN BLUE RIDGE. SCATTERED THUNDERSTORMS ARE ALSO EXPECTED
OVER SOUTHEAST WEST VIRGINIA MORE ON THE EDGE OF UPPER RIDGE.
MSAS ANALYSIS OF THETA-E VALUES AND THE LIFTED INDEX SHOWS THE
WARM FRONT HAS LIFTED NORTH AND EXTENDED FROM MARYLAND TO SOUTHERN
OHIO. THE WEDGE HAS ERODED. MODIFIED SOUNDINGS FROM RNK AND GSO
SHOWED CAPES THIS AFTERNOON NEAR 3000 J/KG AND DCAPES AROUND 500
J/KG. A FLASH FLOOD WATCH HAS BEEN ISSUED ALONG AND EAST OF THE
BLUE RIDGE.
AS OF 255 AM EDT SATURDAY...
WARM FRONT ACROSS THE CENTRAL CWA THIS MORNING WILL LIFT NORTH AND
BASICALLY DISSIPATE BY AFTERNOON AS A GRADUALLY DEEPENING SOUTH/SW
FLOW DEVELOPS AROUND THE RIDGE OFFSHORE. BEHIND THE FRONT WILL SEE A
CONTINUED INFLUX OF WARMER AND MORE HUMID AIR WHICH PROVIDED ENOUGH
HEATING SHOULD SPARK ANOTHER ROUND OF SHRA/TSRA INTO THIS EVENING.
HOWEVER IN THE WAKE OF THE BOUNDARY...FOCUS LIKELY TIED MORE TO
OROGRAPHICS IN THE WEST AND OLD OUTFLOW IN THE EAST...PRODUCING A
MORE SCATTERED NATURE COVERAGE PER LATEST HRRR AND LOCAL WRF SOLNS.
APPEARS DEVELOPING SW FLOW AND HIGHER THETA-E MOUNTAINS SHOULD
SUPPORT BETTER COVERAGE NEAR THE BLUE RIDGE AND PERHAPS THE NW
WHERE WILL BE CLOSEST TO THE RESIDUAL FRONT. THUS MAY INCLUDE SOME
LOW AFTERNOON LIKELY POPS IN SPOTS ALONG THE RIDGES...WITH MAINLY
CHANCE COVERAGE ELSW WITH SOME OF THIS DEVELOPING LATER THIS
MORNING AS HEATING GETS GOING. LATEST FORECAST SOUNDINGS ALSO SHOW
WEAK MID LEVEL STEERING OF AROUND 10 MPH AND VERY MOIST PWATS OF
1.75 INCHES OR BETTER SO SLOW MOVING HEAVY RAINERS A THREAT
ESPCLY IF THINGS BAND UP ALONG THE RIDGES. DEGREE OF CLOUD COVER
TRICKY BY AFTERNOON WITH GUIDANCE SUGGESTING SOME BREAKS BUT THEN
QUICKLY DEVELOP CONVECTION WHICH MAY CURTAIL TEMP RISES. LATEST
MAV MOS LOOKS TOO WARM GIVEN EARLY CLOUDS AND AFTERNOON SHRA WHILE
THE MET TOO SLOW TO EXIT THE WEAK WEDGE. THUS GOING IN BETWEEN AND
CLOSER TO THE ENSEMBLE HIGHS WHICH PUTS THE WEST IN THE 76-82
RANGE AND MAINLY MID/UPR 80S EAST.
UPPER RIDGE OFFSHORE SHIFTS FARTHER WEST OVERNIGHT PUSHING THE
LINGERING DEEPER MOISTURE AXIS ALONG THE WESTERN SLOPES FARTHER
INLAND. THIS ALONG WITH SLIGHTLY HIGHER 5H HEIGHTS SHOULD END MOST
CONVECTION THIS EVENING ALLOWING FOR MOSTLY CLEAR TO PC SKIES
OVERNIGHT WITH SOME PATCHY FOG AROUND...AND ONLY AN ISOLATED SHRA
THREAT FAR WEST. WILL BE QUITE WARM AND MUGGY WITH LOWS 65-72
UNDER A MOIST AND SOUPY ENVIRONMENT IN THE WAKE OF ANY EARLIER
STORMS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
SEVERAL WEATHER FEATURES WILL CONVERGE OVER THE MID ATLANTIC REGION
AND KEEP THE CHANCES FOR SHOWERS AND THUNDERSTORMS IN THE FORECAST
THROUGH EARLY NEXT WEEK. AN UPPER LEVEL TROUGH OVER THE GREAT LAKES
AND A VORTICITY AXIS IN THE OHIO VALLEY WILL SLOWLY MOVE TO THE EAST
THROUGH THE PERIOD. AN UPPER LEVEL RIDGE...CURRENT OVER THE
REGION...WILL DRIFT TO THE SOUTH ALLOWING THE VORTICITY AXIS TO MOVE
OVER THE MOUNTAINS SUNDAY AND THE UPPER LEVEL TROUGH TO MOVE INTO
THE REGION MONDAY AND TUESDAY. WITH THE ADDITION OF SHORT WAVES
COMING AROUND THE UPPER LEVEL RIDGE AND A SURFACE LEE TROUGH IN THE
PIEDMONT...SCATTERED SHOWERS AND THUNDERSTORMS WILL REMAIN IN THE
FORECAST THROUGH THE PERIOD. WILL KEEP THE HIGHEST POPS DURING PEAK
HEATING AND MAINLY OVER THE MOUNTAINS SUNDAY AND MONDAY. ANY STRONG
STORMS THAT DEVELOP DURING THIS PERIOD WILL MOVE SLOW AND COULD
RESULT IN LOCALIZE FLASH FLOODING.
SCATTERED SHOWERS SHOULD HELP COOL AFTERNOON TEMPERATURES...BUT
UNTIL THEY DO...AFTERNOON TEMPERATURES WILL RUN ABOVE NORMAL BY 5F
TO 10F. IF THESE SHOWERS COOLING THE TEMPERATURES...RELATIVE
HUMIDITY WILL INCREASE...RESULTING IN MUGGY AND UNCOMFORTABLE
CONDITIONS. MOS GUIDANCE TEMPERATURES ARE SIMILAR...THERE I DID NOT
STRAY TO FAR FROM THEM.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 300 PM EDT FRIDAY...
BROAD UPPER RIDGE REMAINS OVER THE SOUTHEAST UNITED STATES. RIDGE
FLATTENS ON THURSDAY AND FRIDAY. SURFACE FRONT DROPS THROUGH SOUTH
INTO THE MID ATLANTIC REGION BY FRIDAY. CHANCE OF SHOWERS AND
THUNDERSTORMS WILL IMPROVE THURSDAY AND FRIDAY AHEAD OF THE FRONT.
OTHERWISE NO DISTINCT FEATURES TO HELP ORGANIZE ANY THUNDERSTORMS
TUESDAY AND WEDNESDAY. HOWEVER...AIR MASS WILL BE WARM AND UNSTABLE
WITH 850 MB TEMPERATURES IN THE +18 TO +20 RANGE. WILL KEEP DAILY
PROBABILITY OF AFTERNOON AND EVENING THUNDERSTORMS IN THROUGH THE
PERIOD. TEMPERATURES WILL REMAIN SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 645 AM EDT SATURDAY...
SHOWERS CONTINUE ALONG THE SOUTHERN BLUE RIDGE ATTM AND EXPECT
SOME THIS COVERAGE MAY AFFECT KBCB/KROA OVER THE NEXT FEW HOURS
BEFORE FADING. OTRW EXPECT A VARIETY OF CIGS AND VSBYS ACROSS THE
REGION EARLY ON...RANGING FROM IFR/MVFR ALONG AND EAST OF THE BLUE
RIDGE TO MAINLY VFR OVER THE WEST. MAY ADD IN A VCSH MENTION AT
KBCB AND KROA THIS MORNING BEFORE THINGS MIX OUT A BIT TO PERHAPS
A PERIOD OF VFR AT ALL LOCATIONS BEFORE RENEWED CONVECTION GETS
GOING AFTER MIDDAY. SHOWERS AND STORMS WILL AGAIN BE POSSIBLE BY
EARLY AFTERNOON ESPCLY OVER THE WEST WITH MORE WIDELY SCATTERED
COVERAGE LIKELY ACROSS EASTERN LOCATIONS. APPEARS THAT WITH
ENOUGH HEATING MAY HAVE DECENT COVERAGE ESPCLY ACROSS THE
MOUNTAINS SO ENOUGH CONFIDENCE TO INCLUDE AT LEAST A VCTS OR
PREVAILING SHRA MENTION OVER A FEW LOCATIONS IN THE WEST AND VCSH
OUT EAST IN THE AFTERNOON. THESE STORMS MAY BE SLOW MOVING WITH
PERIODS OF MVFR/IFR POSSIBLE PENDING THE DEGREE OF ORGANIZATION
LATER ON. EXPECTING SHRA/TSRA TO FADE A BIT SOONER THIS EVENING
BEFORE GIVING WAY TO VFR BEFORE FOG DEVELOPS MAINLY AFTER
MIDNIGHT ESPCLY IN THE VALLEYS AND WHERE EARLIER RAIN OCCURRED.
THE FRONT WILL CONTINUE TO LIFT NORTH DURING THE REMAINDER OF THE
WEEKEND. SHRA/TSRA COVERAGE WILL CONTINUE TO TREND MORE DIURNAL
AND ALONG THE MOUNTAIN RIDGES. MOST AREAS WILL EXPERIENCE VFR
CONDITIONS OUTSIDE OF THE HEAVIER SHRA/TSRA. LATE NIGHT IFR/MVFR
MOUNTAIN AND RIVER VALLEY FOG WILL BE POSSIBLE.
EARLY NEXT WEEK...HIGH PRESSURE GRADUALLY BUILDS INTO THE AREA
WITH PROGRESSIVELY MILDER TEMPERATURES AND A STRONG CAPPING
INVERSION ALOFT. CONDITIONS WILL BE MAINLY VFR EXPECT BRIEFLY
UNDER THOSE ISOLATED AREAS THAT RECEIVE A MODERATE TO HEAVY SHOWER
OR STORM.
&&
.HYDROLOGY...
A FLASH FLOOD WATCH HAS BEEN ISSUED ALONG AND EAST OF THE BLUE
RIDGE FOR THIS AFTERNOON AND EVENING. MODIFIED SOUNDINGS FROM RNK
AND GSO SHOWED PRECIPITABLE WATER VALUES OF 1.7 TO 2.0 INCHES
WHICH IS ABOUT 140 PERCENT OF NORMAL. WARM CLOUD DEPTH IS AROUND
20,000 FEET AND STEERING FLOW IS ONLY 5 TO 10 KNOTS SO HEAVY RAIN
IS EXPECTED. FFG IN SOME SPOTS OF THE FOOTHILLS AND PIEDMONT...
ESPECIALLY FROM WILKES COUNTY INTO PITTSYLVANIA COUNTY IS NEAR 2
INCHES. GETTING RATES OF 2 INCHES IN AN HOUR IS POSSIBLE TODAY.
&&
.EQUIPMENT...
NOAA ALL HAZARDS RADIO FOR THE HINTON TRANSMITTER REMAINS OFF THE
AIR DUE TO COMMERCIAL POWER NOT REACHING THE SITE.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR VAZ015>017-
022>024-032>035-043>047-058-059.
NC...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR NCZ001>006-
018>020.
WV...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...AMS/JH
SHORT TERM...RCS
LONG TERM...AMS
AVIATION...DS/JH/KK
HYDROLOGY...AMS
EQUIPMENT...JH
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
229 PM CDT SAT JUL 14 2012
.SHORT TERM...TONIGHT AND SUNDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW WEAK SHORTWAVE
TROUGHING EXTENDING FROM LAKE SUPERIOR TO THE SOUTHERN MISSISSIPPI
VALLEY EARLY THIS AFTERNOON. SCATTERED TO NUMEROUS SHOWER ACTIVITY
DEVELOPED MIDDAY OVER NORTH-CENTRAL AND FAR NORTHEAST WISCONSIN
THOUGH ACTIVITY HAS BEEN MUCH SLOWER TO DEVELOP OVER THE FOX VALLEY
AND CENTRAL WISCONSIN. THE MOST PROMINENT BAND OF BROKEN SHOWERS APPEARS TO
BE ALONG A SURFACE TROUGH WHICH EXTENDS FROM ABOUT HOUGHTON TO EAU
CLAIRE. AS THE TROUGH EXITS THE AREA LATE THIS EVENING...PRECIP
CHANCES ARE THE MAIN FORECAST CONCERN TONIGHT FOLLOWED BY TEMPS
TOMORROW.
TONIGHT...THE SHORTWAVE TROUGH WILL MOVE ACROSS EASTERN WISCONSIN
DURING THE EVENING HOURS. FEEL THAT MUCH OF THE SHOWER AND
THUNDERSTORM ACTIVITY WILL DIMINISH FAIRLY QUICKLY WITH LOSS OF
DAYTIME HEATING...BUT CONVERGENCE UP TO 700 MB DOES LINGER OVER THE
FAR EAST UNTIL 06Z SO WILL KEEP AN ISOLATED SHOWER MENTION THROUGH
THAT TIME. PLENTY OF MOSTLY CLEAR SKIES UPSTREAM OVER MINNESOTA AND
THINK THIS CLEARING WILL ARRIVE TONIGHT BEHIND THE TROUGH. THE
BOUNDARY LAYER WILL REMAIN MOIST...ESPECIALLY IF GOOD RAINS DEVELOP
THIS AFTERNOON...SO THINK THE COMBO OF LIGHT WINDS AND CLEAR SKIES
WILL PROMOTE FOG FORMATION. WILL INCREASE WORDING TO AREAS OF FOG
OVER THE HIGHER TERRAIN. LOWS MAINLY IN THE 60S WITH SOME 50S IN
THE COLD SPOTS.
SUNDAY...THE TROUGH WILL HAVE MOVED WELL TO EAST AT THE START OF
SUNDAY...AND MID-LEVEL HEIGHTS WILL BE REBOUNDING THROUGH THE DAY.
LIKE THE PREVIOUS FORECAST MENTIONED...WILL HAVE INSTABILITY DEVELOP
THROUGH THE DAY WITH STEEP LOW LEVEL LAPSE RATES. BUT PLENTY OF DRY
AIR WILL EXIST ABOVE THE MIXED LEVEL AND PROGGED SOUNDINGS INDICATE
CAPPING WILL STRENGTHEN AS HEIGHTS REBOUND. DESPITE WEAK
CONVERGENCE DEVELOPING OVER NE WISCONSIN ALONG THE LAKE
BREEZE...THINK THE MIXING OF THE DRIER AIR ALOFT AND STRENGTHENING
CAPPING WILL THWART SHOWER DEVELOPMENT. WILL STICK WITH A DRY
FORECAST. 850MB TEMPS AROUND 20C ARGUES FOR LOW 90S FOR HIGHS...AND
WILL GO WITH UPPER 80S NORTH TO MID 90S SOUTH.
.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY.
OVERALL CURRENT TROF AND RIDGE PATTERN OVER THE U.S TO FLUCTUATE A
BIT OVER AREA THROUGH THE PERIOD WITH MAIN WESTERLIES REMAINING
OVER CENTRAL CANADA. MUCH OF THIS PERIOD WILL BE DEALING WITH
RIDGE...ITS STRENGTH AND LOCATION AND ITS EFFECT ON TEMPERATURES.
EXPECT CONTINUATION OF VERY WARM TO HOT CONDITIONS FOR MONDAY AND
OVER THE SOUTH HALF ON TUESDAY BEFORE CANADIAN HIGH PRESSURE
BRINGS SOME RELIEF TO ENTIRE AREA WEDNESDAY ONWARD. OVERALL MAX
TEMPERATURES TO RUN AT OR ABOVE NORMS.
ON MONDAY...INCREASING SOUTH TO SOUTHWEST FLOW AHEAD OF LOW
PRESSURE OVER THE PLAINS TO CONTINUE HOT AND HUMID CONDITIONS WITH
OVERNIGHT CONDITIONS SUN AND MON LEANING TOWARDS MUGGY SIDE. HEAT
INDICES OVER FAR SOUTHERN CWA TO REACH 100 DURING THE AFTERNOON.
LOW PRESSURE PASS TO OUR NORTH WILL PULL FRONT INTO LAKE SUPERIOR
REGION. HAVE SLOWED PCPN MOVING INTO AREA KEEPING IT CLOSER TO OR
BEHIND FRONT...MORE COLLATED WITH 850 BAROCLINIC ZONE. BEST POPS
NORTH MON NIGHT CLOSER TO SUPPORTING JET DYNAMICS.
ON TUESDAY...FRONT TO DROP SOUTH INTO SOUTHERN WI BY LATE
AFTERNOON. FRONT WEAKENS AND HAVE LOSS OF JET SUPPORT...SO WILL
STAY WITH LOWER POPS AS IT MOVES SOUTH. QUESTION THIS DAY IS MORE
ON TEMPS WITH CLOUDS AND PCPN CAUSING ISSUES. FOR BOTH MONDAY AND
TUESDAY...WESTERLY COMPONENT TO LLVL WINDS TO KEEP LAKE BREEZE RIGHT
ALONG LAKE. SHEER IS LIMITED THROUGH THE PERIOD...SO DO NOT EXPECT
ANY SIG SEVERE ATTM.
HIGH PRESSURE DROPPING OUT OF CANADA WILL BRING A BIT LESS HEAT
BUT ALSO DRIER AIRMASS INTO STATE...WITH DEW POINTS RETURNING INTO
THE LOWER HALF OF THE 50S. DROPPED OVERNIGHT LOWS SLIGHTLY.
&&
.AVIATION...AN UPPER TROUGH WILL SLOWLY MOVE ACROSS CENTRAL AND
EASTERN WISCONSIN THROUGH THIS EVENING. SHOWERS AND THUNDERSTORMS
ARE STILL EXPECTED TO DEVELOP ACROSS THE AREA BY EARLY THIS
AFTERNOON. THE STRONGER STORMS WILL BE CAPABLE OF PRODUCING MVFR
CIGS...IFR VSBYS AND GUSTY WINDS UP TO 40 MPH. PRECIPITATION WILL
BE DIMINISHING THIS EVENING WITH LOSS OF DAYTIME HEATING...THOUGH
FOG WILL THEN BECOME A CONCERN THROUGH THE NIGHT ASSUMING SHOWERS
HIT THE TAF SITES. HAVE KEPT THE PREVIOUS FORECAST IN TACT FOR
FOG...THOUGH LATER SHIFTS MAY REVISE DEPENDING UPON SHOWER COVERAGE
THIS AFTERNOON. ONCE THE FOG BURNS OFF TOMORROW MORNING...VFR
CONDITIONS WILL RESUME.
MPC
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MPC/TE
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1153 AM CDT SAT JUL 14 2012
.UPDATE...
WEAK THETA-E ADVECTION IN SOUTHEAST WI HAS SHIFTED OUT OF THE
FORECAST AREA SO SHOWERS DISSIPATED.
THUNDERSTORMS CURRENTLY IN NORTHEAST IOWA ARE BEING DRIVEN BY THE
500MB VORTICITY ADVECTION WITH A SHARP UPPER TROUGH MOVING
ACROSS...RIGHT ALONG A SURFACE WIND SHIFT AXIS. THEY ARE SUPPORTED
BY 250MB DIVERGENCE...850-700MB Q-VECTOR CONVERGENCE...AND WEAK
925-850MB FRONTOGENESIS. EXPECT THIS AREA OF FORCING TO VERY SLOWLY
MOVE INTO SOUTH CENTRAL WI THIS AFTERNOON.
ASIDE FROM THUNDERSTORMS EXPECTED TO DEVELOP ALONG THE MAIN UPPER
TROUGH AXIS AS IT MOVES INTO SOUTH CENTRAL WI THIS AFTERNOON...THERE
IS WEAK FORCING AND INSTABILITY TO SUPPORT SCATTERED SHOWERS AND
THUNDERSTORMS TO DEVELOP ELSEWHERE ACROSS THE FORECAST AREA BY EARLY
AFTERNOON. ACTIVITY WILL BE FOUND MOSTLY IN THE FORM OF SMALL
CLUSTERS OR SHORT LINES...AND OLD OUTFLOW BOUNDARIES WILL BE FAVORED
LOCATIONS FOR STORM GENERATION...GIVEN LACK OF A COLD FRONT OR WARM
FRONT PASSAGE.
KEPT SCATTERED THUNDERSTORM WORDING IN THE FORECAST FOR THIS
AFTERNOON. CUMULUS CLOUDS ARE ALREADY STARTING TO GROW TALLER PER
LATEST VISIBLE SATELLITE IMAGERY. PRECIPITABLE WATER VALUES ARE
AROUND 1.5 TO 1.7 THIS AFTERNOON AND K INDEX VALUES ARE IN THE MID
30S...SIMILAR TO THE SCENARIO YESTERDAY. RAP SHORT TERM MODEL STILL
SHOWS MINIMAL CAPE AND SHEAR...SO MAIN THREAT FOR ANY THUNDERSTORMS
WILL BE GUSTY WINDS UP TO 40 MPH DUE TO THE RELATIVELY DRY AIR BELOW
5000 FEET...ALONG WITH HEAVY DOWNPOURS.
MAY NEED TO BUMP UP TEMPS A BIT CLOSER TO 90 FOR TODAY IF THE SKIES
STAY CLEAR LONGER. WAS ORIGINALLY EXPECTING MORE CLOUD COVER...AND
THE CLOUDS SHOULD STILL FILL IN MORE THIS AFTERNOON WITH THE DAYTIME
HEATING AND RICH LOW LEVEL MOISTURE. DEWPOINT TEMPS ARE IN THE MID
60S.
&&
.AVIATION/18Z TAFS/...
SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ACROSS ALL OF
SOUTH CENTRAL AND SOUTHEAST WI UNTIL THE UPPER TROUGH MOVES THROUGH
BY MIDNIGHT TONIGHT. DAYTIME SURFACE HEATING WILL ALSO AID IN THE
DEVELOPMENT OF AFTERNOON STORMS TODAY. ACTIVITY WILL BE FOUND MOSTLY
IN THE FORM OF SMALL CLUSTERS OR SHORT LINES...AND OLD OUTFLOW
BOUNDARIES WILL BE FAVORED LOCATIONS FOR STORM GENERATION...GIVEN
LACK OF A COLD FRONT OR WARM FRONT PASSAGE. IF A THUNDERSTORM MOVES
OVER THE TAF SITE...VISIBILITIES WILL DROP WITH BRIEF PERIODS OF
HEAVY RAIN...AND GUSTS TO 35 KNOTS AND SMALL HAIL ARE POSSIBLE.
BEST CHANCE FOR STRONGER THUNDERSTORMS WILL BE ALONG THE TROUGH AXIS
AND SURFACE WIND SHIFT AXIS...WHICH IS IN NORTHEAST IOWA/FAR WESTERN
WI THIS MORNING...AND WILL BE VERY SLOWLY MOVING EASTWARD ACROSS
SOUTH CENTRAL WI THIS AFTERNOON. IT WILL NOT REACH SOUTHEAST WI
UNTIL THIS EVENING.
&&
.PREV DISCUSSION... /ISSUED 318 AM CDT SAT JUL 14 2012/
TODAY AND TONIGHT...FORECAST CONFIDENCE HIGH.
MODELS HAVE BEEN PERSISTENT IN MOVING SOMEWHAT SHARP SHORT-WAVE
ACROSS WISCONSIN TODAY AND TONIGHT. AHEAD OF THIS FEATURE IS FOUND
WARM AIR ADVECTION AND CONVERGENCE FROM 5 TO 10 THSD FT AGL...WHICH
HAS FUELED BANDS AND CLUSTERS OF SHOWERS AND STORMS. ONE BAND WILL
MOVE ACROSS SOUTHERN WI EARLY THIS MORNING. LATER ON IN MID-LATE
MORNING HOURS WE SHOULD SEE EFFECTS OF MAIN TROF COUPLED WITH
DAYTIME HEATING. MAIN TROUGH IS REFLECTED BY LINE OF CONVECTION FROM
WEST OF LA CROSSE UP TO TAYLOR COUNTY AT 3 AM. AS THE STORM
PREDICTION CENTER INDICATED...DAYTIME HEATING WITH DECENT CAP...BUT
LIMITED BULK SHEAR WILL ONLY ALLOW FOR ISOLATED LOW-END SEVERE
STORMS. IN ANY CASE...ANY STORMS TODAY SHOULD BE ABLE TO PRODUCE
WIND GUSTS TO 40 MPH AND SOME SMALL HAIL...SIMILAR TO YESTERDAY AND
OVERNIGHT.
THETA-E CONVERGENCE AND CYCLONIC FLOW WITH SHORT WAVE TONIGHT WILL
LEAD TO CONTINUATION OF FORMATION OF BANDS AND SMALL CLUSTERS OF
SHOWERS AND STORMS...SO WILL GO WITH POPS OF 40 TO 60 PERCENT GIVEN
DEWPOINTS IN THE 60S. MODELS PRETTY MUCH BRING BACK SIDE OF TROUGH
THROUGH BY 06Z. AFTER 06Z THE NAM/GFS/ECMWF LINGER SOME SHOWER
ACTIVITY ACROSS SOUTHEAST WISCONSIN WITH HANG-BACK PORTION OF
TROUGH. HOWEVER...CANADIAN MODEL ENDS PRECIPITATION CHANCES BY 06Z.
HAVE GONE DRY AFTER 06Z TO BLEND IN WITH NEIGHBORING WEATHER
OFFICES.
SUNDAY - CONFIDENCE...MEDIUM
SURFACE/850 MILLIBAR TROUGH AXIS EXITS THE SOUTHEAST CORNER. PRECIP
CONFINED TO THE EAST OF THIS FEATURE. WILL STICK WITH THE GOING DRY
LOOK PER ALLBLEND POPS. MAIN STORY WILL BE THE BUILDING UPPER RIDGE
WITH WARMING 925 TEMPS. GFS HAS A USUAL COOL AND MOIST BIAS WHILE
THE ECMWF AND NAM ARE ON THE SAME PAGE WITH THE 925 TEMPS REACHING
25-28C...EAST TO WEST. LEANED TOWARDS THE LOWER NAM MOS DEW POINTS.
MONDAY - CONFIDENCE...MEDIUM
588-590DM UPPER RIDGE ACROSS THE UPPER MIDWEST. THE HEAT KICKS IN
EVEN FURTHER WITH 925 TEMPS NOW TO 28-30C. SHOULD BE ABLE TO CRACK
100 IN SOME SPOTS AGAIN. GFS DEW POINTS LOOK TOO HIGH...LEANED MORE
IN THE MID TO UPPER 60S. WILL LIKELY REACH ADVISORY CRITERIA.
TUESDAY AND WEDNESDAY - CONFIDENCE...MEDIUM
UPPER RIDGE COLLAPSES A BIT WITH SURFACE/850 FRONT STARTING TO MAKE
A SOUTHWARD PUSH...HOWEVER NAM/ECMWF/GEMNH SUGGEST PRECIP CONFINED
MORE TO NORTHERN/CENTRAL WI IN CLOSER PROXIMITY TO 850 MILLIBAR
BAROCLINIC ZONE. ECMWF/GFS SURFACE FRONTAL TIMING FAIRLY
CLOSE...EDGING INTO SRN WI DURING THE AFTERNOON. HOWEVER PRIOR TO
THE ARRIVAL OF THE FRONT THE 925 TEMPS DO STILL SUGGEST A HOT
AIRMASS WILL BE MAINTAINED ACROSS MUCH OF SRN WI WITH READINGS OF
28-30C. DEW POINTS WELL INTO THE 60S SHOULD ONCE AGAIN LIKELY
SUPPORT ADVISORY TYPE HEAT HEADLINES. TRENDED POPS NORTH AS GFS
GENERATING TOO MUCH WARM SECTOR PRECIP. APPEARS AIRMASS WILL LIKELY
BE CAPPED WITH BULK OF CONVECTION ELEVATED IN POST-FRONTAL FASHION.
THIS BEST PLAYED OUT BY ECMWF/GEM AND EXTRAP OF NAM. THIS TRANSLATES
TO BEST WINDOW FOR SRN WI PRECIP TUESDAY NIGHT INTO WEDNESDAY
MORNING.
THURSDAY AND FRIDAY - CONFIDENCE...MEDIUM
HIGH PRESSURE LOOKS TO BE IN CONTROL. A BRIEF COOLER REGIME THURSDAY
WITH EASTERLY FLOW THEN TEMPS REBOUND AGAIN FRIDAY WITH A MORE OF A
LOW LEVEL SOUTHERLY FLOW. UPPER RIDGE AXIS TO OUR WEST WITH SOME
HINT OF RIPPLES RIDING EAST THEN SOUTHEAST IN THE UPPER FLOW. GEM
AND GFS MORE AMPLIFIED WITH RIDGE THAN ECMWF.
AVIATION/12Z TAFS/...DOMINATE WEATHER WILL BE VFR CONDITIONS FOR
THE TAF PERIOD...BUT THERE WILL BE SCATTERED SHOWERS AND
THUNDERSTORMS. HOWEVER...MOISTURE FROM THE SHOWERS WILL ALLOW FOR
SCATTERED AREAS OF FOG THROUGH 12Z WITH VISIBILITIES OF 3 TO 5
MILES. IF A THUNDERSTORM MOVES OVER THE TAF SITE...VISIBILITIES
WILL DROP TO AROUND 3 MILES...AND GUSTS TO 35 KNOTS AND SMALL HAIL
ARE POSSIBLE. THIS HAPPENED WITH A CELL THAT MOVED OVER THE MTROVS
/BOSCOBEL/ LOCATION IN THE PREDAWN HOURS OF SATURDAY MORNING. AN
UPPER-LEVEL WEATHER DISTURBANCE WILL DROP SOUTHEAST ACROSS
WISCONSIN TODAY AND EARLY TONIGHT. DAYTIME SURFACE HEATING WILL
ALSO AID IN THE DEVELOPMENT OF AFTERNOON STORMS. ACTIVITY WILL BE
FOUND MOSTLY IN THE FORM OF SMALL CLUSTERS OR SHORT LINES...AND
OLD OUTFLOW BOUNDARIES WILL BE FAVORED LOCATIONS FOR STORM
GENERATION...GIVEN LACK OF A COLD FRONT OR WARM FRONT PASSAGE.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...KAPELA
SUNDAY THROUGH FRIDAY...COLLAR