Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/15/15
AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
846 PM PDT TUE JUL 14 2015
.UPDATE...
A FEW THUNDERSTORMS CONTINUE ACROSS EASTERN MONO INTO MINERAL
COUNTIES AT THIS HOUR, INCLUDING ONE RATHER PERSISTENT CELL WHICH
TRACKED FROM WEST OF HAWTHORNE TO NEAR LUNING. THIS AREA HAD
SLIGHTLY ENHANCED 3-6KM AGL SHEAR SO NOT ENTIRELY SURPRISING THE
STORM SUSTAINED ITSELF FOR A WHILE. EVEN SOME VERY BROAD ROTATION
SEEN ON NWS RENO RADAR.
BASED ON LATEST RADAR TRENDS AND HRRR GUIDANCE, THIS ACTIVITY
SHOULD CONTINUE FOR ANOTHER COUPLE HOURS BEFORE DISSIPATING. UPPER
WAVE WHICH PROVIDED SOME SUPPORT FOR STORM DEVELOPMENT THIS
AFTERNOON WILL SCOOT TO THE EAST BY 6Z WHICH SHOULD PUT AN END TO
SHOWERS OVERNIGHT IN THE ABSENCE OF SUFFICIENT INSTABILITY ALOFT.
REST OF THE FORECAST IS UNCHANGED. CS
&&
.PREVIOUS DISCUSSION... /ISSUED 1245 PM PDT TUE JUL 14 2015/
SYNOPSIS...
A SLOW WARMING TREND THIS WEEK WILL BRING AFTERNOON TEMPERATURES TO
NEAR NORMAL BY FRIDAY. A LOW PRESSURE SYSTEM FROM THE PACIFIC NORTHWEST
INCREASES THE CHANCES FOR THUNDERSTORMS STARTING FRIDAY, AND
THERE IS POTENTIAL FOR A COOLER AND WETTER WEATHER PATTERN FOR THE
START OF NEXT WEEK.
SHORT TERM...
A WEAK UPPER-LEVEL WAVE IS CURRENTLY CROSSING WESTERN NV.
MEANWHILE, CUMULUS DEVELOPED OVER HIGHER TERRAIN SOUTH OF I-80
AFTER 11 AM THIS MORNING. WHILE THE AIR MASS IS OVERALL FAIRLY
STABLE TODAY, AFTERNOON HEATING COULD LEAD TO ISOLATED
THUNDERSTORMS IN MONO/MINERAL COUNTIES THIS AFTERNOON, POSSIBLY
MOVING INTO WESTERN LYON AND SOUTHERN CHURCHILL COUNTIES BY LATE
AFTERNOON OR EVENING. CONFIDENCE IS LOWER, BUT ISOLATED STORMS
THIS AFTERNOON IN THE CONVERGENCE ZONE DOWNSTREAM OF LASSEN PEAK
ALSO CAN`T BE RULED OUT.
FOR TOMORROW, WEAK UPPER LOW-PRESSURE WITH A TROUGH AXIS OVER CA
WILL LEAD TO A SLIGHTLY WARMER AIR MASS BUT LITTLE INCREASE IN
INSTABILITY. THERE IS STILL A SLIGHT CHANCE FOR AFTERNOON
THUNDERSTORMS IN ALPINE, MONO AND MINERAL COUNTIES. FOR THE TAHOE
BASIN TOMORROW, CUMULUS BUILDUPS ARE EXPECTED BUT WITH NOT QUITE
ENOUGH INSTABILITY FOR THUNDERSTORMS. FOR THURSDAY, THE UPPER-
LEVEL PATTERN WILL PERSIST BUT WITH A SLIGHT EASTWARD PUSH OF
MOISTURE ACROSS THE SIERRA. AS SUCH, THE BEST POTENTIAL FOR
THUNDERSTORMS THURSDAY AFTERNOON/EVENING IS OVER THE SIERRA AND
ALONG THE SIERRA FRONT RANGE. JCM
LONG TERM...FRIDAY THROUGH MONDAY...
NOT MUCH CHANGE IN THE LOCATION OF LARGE SCALE PATTERN OVER THE LAST
24 HOURS. TWO LARGE HIGH PRESSURE SYSTEMS, ONE OVER TEXAS AND THE
SECOND OVER THE NORTHEAST PACIFIC, REMAIN THE DOMINATE WEATHER
FEATURES. HOWEVER FORECAST CONFIDENCE REMAINS LOW TO MEDIUM DUE TO
VARYING MODEL SOLUTIONS WITH SMALLER FEATURES TRACKING AROUND THE
HIGHS.
ENERGY FROM A SPLITTING TROUGH FROM THE PACIFIC NORTHWEST SHOULD
DIG OFF THE NORTHERN CALIFORNIA COAST ON FRIDAY AND SATURDAY. THIS
MAY LEAD TO COOLER, CLOUDY CONDITIONS WITH SHOWERS AND
THUNDERSTORMS FRIDAY, SATURDAY AND SUNDAY. BREEZY AFTERNOON AND
EVENING WINDS ARE ALSO POSSIBLE ALONG THE SIERRA FRONT FRIDAY AND
SATURDAY.
BY THE START OF NEXT WEEK THE RIDGE OVER TEXAS MAY RETROGRADE TO
THE DESERT SOUTHWEST AND HELP PUSH THE REMNANTS OF DOLORES
NORTHWARD. MODELS CONTINUE TO VARY WIDELY, FROM KEEPING DOLORES WELL
OVER THE PACIFIC AND WITH LITTLE IF ANY IMPACT, TO DRIVING MID AND
UPPER LEVEL MOISTURE INTO CALIFORNIA. CERTAINLY SOMETHING TO KEEP AN
EYE ON THE NEXT FEW DAYS ESPECIALLY IF THE TEXAS RIDGE SHIFTS OVER
THE DESERT SOUTHWEST. THIS COULD PRODUCE MORE UNSTABLE CONDITIONS
ALONG THE SIERRA CREST AND WESTERN NEVADA WITH A NORTHWARD MOISTURE
PUSH FROM THE SUBTROPICS. BRONG
AVIATION...
ISOLATED THUNDERSTORMS ARE POSSIBLE SOUTH OF BRIDGEPORT-FALLON AND
NORTH OF SUSANVILLE-GERLACH UNTIL 03Z. BRIEF HEAVY RAIN AND OUTFLOW
WINDS TO 45 KTS ARE POSSIBLE.
A FEW THUNDERSTORMS MAY BE ABLE TO DEVELOP WEDNESDAY AFTER 21Z SOUTH
OF MINDEN-FALLON. THUNDERSTORM POTENTIAL INCREASES A BIT FOR
THURSDAY WITH 10-15% CHANCE OF STORMS AROUND THE RENO-CARSON-TAHOE
AREA. BRONG
&&
.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 PUEBLO CO
551 PM MDT TUE JUL 14 2015
.UPDATE...
ISSUED AT 550 PM MDT TUE JUL 14 2015
BUMPED UP POPS OVER FAR EASTERN PLAINS AND MENTIONED HEAVY RAIN IN
THE NDFD. /HODANISH
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 300 PM MDT TUE JUL 14 2015
UPPER LEVEL HIGH PRESSURE REMAINS CENTERED OVER TX THIS
AFTERNOON...KEEPING MOIST SSW MID LEVEL FLOW IN PLACE ACROSS
COLORADO. LOWER LEVELS HAVE CONTINUED TO MOISTEN TODAY...AS SURFACE
DEWPOINTS ARE RUNNING AROUND 10F HIGHER THAN 24 HRS AGO. OVER THE
MOUNTAINS...CAPES ARE IN THE 500-1000 J/KG RANGE...WHILE CAPE OVER
THE PLAINS ALONG THE NM AND KS BORDERS EXCEEDS 1000 J/KG. RELATIVE
MIN IN THE INSTABILITY FIELD LIES OVER EL PASO/PUEBLO/CROWLEY/OTERO
COUNTIES...WHERE DEWPOINTS HAVE DROPPED OFF INTO THE MID TO UPPER
40S...LEADING TO CAPES GENERALLY IN THE 400-800 J/KG RANGE.
CONVECTIVE STRENGTH AND COVERAGE SO FAR TODAY HAS THUS BEEN HIGHER
THAN YESTERDAY MOST AREAS...AND WITH WEAK LEE SURFACE TROUGH OVER
THE PLAINS ENHANCING LOW LEVEL WINDS SLIGHTLY...APPEARS THERE WILL
BE AT LEAST A LOW THREAT OF SEVERE STORMS OVER THE FAR EASTERN
PLAINS...AS 0-6KM SHEAR CLIMBS ABOVE 30 KTS FOR A TIME LATE THIS
AFTERNOON/EARLY THIS EVENING. WHILE WATER VAPOR LOOP SUGGESTS
STRONGEST UPPER WAVE IS FAIRLY FAR TO THE SOUTH OVER SERN
AZ...STREAM OF WEAKER WAVES EMBEDDED IN THE MOIST PLUME WILL
CONTINUE PUSH OVER THE AREA LATE THIS AFTERNOON INTO
TONIGHT...HELPING TO KEEP CONVECTION GOING PAST SUNSET...ESPECIALLY
OVER THE MOUNTAINS AND ACROSS THE FAR EASTERN PLAINS ALONG THE KS
BORDER. MESOSCALE MODELS SUPPORT THIS IDEA...WITH MAIN CLUSTER OF
CONVECTION OVER THE PLAINS THIS EVENING PUSHING INTO KS TOWARD
06Z...WITH HRRR SHOWING A SECONDARY AREA OF MOUNTAIN CONVECTION
MOVING INTO THE I-25 CORRIDOR THIS EVENING. APPEARS MOST STORMS WILL
THEN FADE AWAY BY EARLY WED MORNING...THOUGH CONVECTIVE DEBRIS
CLOUDS MAY LINGER LONG ENOUGH TO KEEP MINS RATHER MILD.
ON WEDNESDAY...MOISTURE LEVELS ACROSS THE MOUNTAINS DON`T CHANGE
VERY MUCH...LEADING TO ANOTHER ROUND OF SCATTERED CONVECTION OVER
MOST HIGH TERRAIN LOCATIONS IN THE AFTERNOON. OVER THE I-25 CORRIDOR
AND EASTERN PLAINS...MODELS SHOW LOW LEVEL WINDS BECOMING WEAKLY
WESTERLY THROUGH THE DAY...SHUNTING THE DEEPER MOISTURE AND
INSTABILITY INTO KS BY LATE AFTERNOON. STILL ENOUGH RESIDUAL
MOISTURE IN PLACE TO PRODUCE ISOLATED TO LOW END SCATTERED
CONVECTION...THOUGH EXPECT BOTH COVERAGE AND INTENSITY TO DECREASE
AS SURFACE LAYER DRIES. MAX TEMPS DRIFT DOWNWARD JUST SLIGHTLY WED
AS MID LEVEL TEMPS COOL...THOUGH READINGS MOST LOCATIONS WILL END UP
WITHIN A COUPLE DEGF OF TUESDAY`S READINGS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 300 PM MDT TUE JUL 14 2015
MODELS CONTINUE TO HAVE ISSUES IN THE EXTENDED PERIOD WITH
DIFFERENCES BETWEEN THE OPERATIONAL SOLUTIONS AND HIGH ENSEMBLE
SPREADS. BOTH THE ECMWF AND GFS ARE IN AGREEMENT THAT SOMETHING
WILL MOVE ACROSS THE AREA...BUT THERE ARE BIG DIFFERENCES IN
TIMING AND TRACK.
WEDNESDAY NIGHT...AN UPPER LEVEL DISTURBANCE WILL BE MOVING ACROSS
THE REGION WEDNESDAY EVENING AND INTO THE CENTRAL PLAINS BY
THURSDAY MORNING. MODELS CONTINUE TO DEVELOP A THUNDERSTORM
COMPLEX ACROSS THE EASTERN PLAINS AND TRACK IT EAST THROUGH THE
OVERNIGHT HOURS. THERE CONTINUE TO BE MODEL DIFFERENCES...WITH
SEVERAL SOLUTIONS ACROSS NORTHEAST COLORADO...AND OTHER OVER
SOUTHEASTERN COLORADO. THUNDERSTORMS THAT DO DEVELOP OVER THE
PLAINS WILL BE CAPABLE OF HEAVY RAINFALL AND AN ELEVATED FLASH
FLOOD RISK...ESPECIALLY WHERE THE STRONG STORMS EXIST. EXPECT
SHOWERS AND THUNDERSTORMS TO SHIFT EAST INTO KANSAS BY THURSDAY
MORNING.
THURSDAY THROUGH SATURDAY...HIGH PRESSURE IS FORECAST TO SIT OVER
TEXAS AND A TROUGH WILL REMAIN OVER THE WEST COAST WITH PERSISTENT
SOUTHWEST FLOW ACROSS COLORADO. SEVERAL EMBEDDED DISTURBANCES IN
THE FLOW WILL LEAD TO NEAR DAILY SHOWERS AND THUNDERSTORMS OVER
THE MOUNTAINS. MODEST STEERING FLOWS ALOFT WILL LIKELY HELP PUSH
THIS ACTIVITY OUT INTO THE I-25 CORRIDOR THROUGH THE EVENING HOURS
BEFORE DISSIPATING AFTER SUNSET. THUNDERSTORMS WILL BE CAPABLE OF
PRODUCING LOCALLY HEAVY RAINFALL AND STRONG THUNDERSTORM WIND
GUSTS. TEMPERATURES WILL REMAIN WARM WITH 90S ACROSS THE LOWER
ELEVATIONS.
SUNDAY THROUGH TUESDAY...MODEL DIFFERENCES BEGIN TO DIVERGE SUNDAY
INTO EARLY NEXT WEEK. BOTH THE ECMWF AND GFS RETROGRADE THE HIGH
PRESSURE FROM TEXAS INTO THE DESERT SOUTHWEST WHILE THE TROUGH
OVER THE WEST COAST EJECT TO THE EAST. THE GFS IS FURTHEST SOUTH
WITH THE UPPER TROUGH...BRINGING IT ACROSS THE AREA SUNDAY INTO
MONDAY WITH WIDESPREAD SHOWERS AND THUNDERSTORMS ACROSS THE
REGION BEFORE DRYING OUT TUESDAY. LOCALLY HEAVY RAINFALL WOULD BE
POSSIBLE WITH A CONTINUED RISK OF FLOODING. THE ECMWF BRINGS THE
UPPER TROUGH ACROSS TO THE NORTH AND SENDS A COLD FRONT ACROSS THE
AREA ON SUNDAY AFTERNOON. IT BRINGS A QUICK SHOT OF WIDESPREAD
SHOWERS AND THUNDERSTORMS TO THE AREA SUNDAY. BY MONDAY THE ECMWF
IS MUCH DRIER WITH WEAK HIGH PRESSURE BUILDING ACROSS THE AREA AND
THE MAIN ENERGY TRACK TO THE SOUTH. GIVEN THE UNCERTAINTY...HAVE
LOW POPS ACROSS THE AREA SUNDAY THROUGH TUESDAY...WITH SUNDAY AND
MONDAY POTENTIALLY BEING WET ACROSS THE AREA. MOZLEY
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 300 PM MDT TUE JUL 14 2015
EXPECT SCATTERED TSRA TO CONTINUE OVER THE AREA INTO THE
EVENING...AND WILL KEEP A VCTS MENTION AT ALL TAF SITES THROUGH 02Z-
04Z. CONVECTION THEN SLOWLY SHIFTS INTO KS AND WEAKENS OVERNIGHT
WITH PERHAPS SOME STRATUS AND FOG OVER THE PLAINS EAST OF I-25 BY
EARLY WED MORNING. WITH WEAK N-NW WINDS AT KCOS AND KPUB...WILL KEEP
CONDITIONS VFR OVERNIGHT...THOUGH THERE IS A LOW CHANCE THAT MCS
OUTFLOW LATE TONIGHT COULD PUSH CLOUDS BACK FARTHER WEST THAN
EXPECTED. ON WED...VFR CONDITIONS AT THE TERMINALS...WITH TSRA
DEVELOPING OVER THE MOUNTAINS BY LATE MORNING ONCE AGAIN. LOW LEVELS
WILL BE SLIGHTLY DRIER OVER THE PLAINS WED...WHICH MAY LEAD TO
WEAKER STORMS BUT STRONGER OUTFLOW WINDS AT KPUB AND KCOS IN THE
AFTERNOON.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HODANISH
SHORT TERM...PETERSEN
LONG TERM...MOZLEY
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
315 PM MDT MON JUL 13 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 235 PM MDT MON JUL 13 2015
UPR HIGH PRESSURE IS CENTERED ABOUT OVR CENTRAL TX TODAY...WITH A
PLUME OF SUB TROPICAL MSTR WORKING ITS WAY AROUND THE BACK SIDE OF
THE UPR HIGH AND INTO CO. AS A RESULT...ISOLD TO SCT SHOWERS AND
TSTMS ARE EXPECTED ACRS THE FORECAST AREA THIS EVENING. AREAS OVR
AND NR THE MTNS SHOULD HAVE THE HIGHEST COVERAGE OF PCPN THIS
EVENING. MUCH OF THE CONVECTIVE ACTIVITY IS EXPECTED TO END BY
AROUND MIDNIGHT...BUT THE NAM AND HRRR INDICATE THE POSSIBILITY OF
SOME ISOLD ACTIVITY CONTINUING THRU THE LATE NIGHT HOURS AND INTO
TUE MORNING.
ON TUE THE UPR HIGH CENTER IS FORECAST TO SHIFT EASTWARD AND BECOME
CENTERED OVR ERN TX AS AN UPR TROF MOVES OVR THE WRN STATES. THE
PLUME OF MSTR WL CONTINUE STREAMING OVR THE AREA ON TUE...AND THERE
WL BE ANOTHER ROUND OF SCT SHOWERS AND TSTMS ACRS MUCH OF THE
FORECAST AREA...MAINLY IN THE AFTERNOON AND EVENING HOURS. LATEST
NAM SHOWS DEW POINTS TUE AFTERNOON IN THE MID OR UPR 40S ALONG THE I-
25 CORRIDOR AND IN THE MID TO UPR 50S NR THE KS BORDER. CAPE VALUES
LOOK FAIRLY LOW OVR MUCH OF THE AREA TUE AFTERNOON ALONG WITH WEAK
DEEP LAYER SHEAR...HOWEVER NR THE KS BORDER 1000-2000 J/KG IS
FORECAST WITH 0-6 KM SHEAR OF 35 TO 40 KTS. AS A RESULT...SPC HAS
THE SOUTHEAST PLAINS IN THE MARGINAL RISK AREA FOR SEVERE STORMS ON
TUE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 235 PM MDT MON JUL 13 2015
MODELS IN DECENT AGREEMENT THROUGH THE FIRST HALF OF THE EXTENDED
PERIOD WITH DIFFERENCE AMONG THE VARIOUS OPERATIONAL SOLUTIONS AND
HIGH ENSEMBLE SPREADS THIS COMING WEEKEND INTO EARLY NEXT WEEK.
TUESDAY NIGHT THROUGH WEDNESDAY...THE UPPER PATTERN WILL FEATURE
HIGH PRESSURE OVER THE SOUTHEAST CONUS WHILE AN UPPER TROUGH SITS
OVER THE PACIFIC NORTHWEST. TWO STRONG WAVES ARE FORECAST TO MOVE
OUT OF THE DESERT SOUTHWEST AND ACROSS COLORADO. THE FIRST WILL BE
LIFTING ACROSS THE ROCKIES TUESDAY EVENING...WITH WIDESPREAD
SHOWERS AND THUNDERSTORMS OVER THE MOUNTAINS EARLY...SPREADING
EAST THROUGH THE OVERNIGHT HOURS. THERE ARE MODEL DIFFERENCES WITH
THE GFS DEVELOPING AN MCS OVER THE PALMER DIVIDE AND LIFTING IT
INTO NORTHEAST COLORADO...WHILE THE NAM DEVELOPS AN MCS AND TRACKS
IT EAST ACROSS OUR EASTERN PLAINS. HEAVY RAIN WILL BE POSSIBLE
ALONG WITH THE THREAT OF FLOODING...INITIALLY OVER THE MOUNTAINS
AND THEN OVER THE PLAINS. HEAVIER RAIN FOR THE PLAINS WILL BE
HIGHLY DEPENDENT ON WHERE THE MCS TRACKS.
ANOTHER WAVE IS FORECAST TO LIFT NORTHEAST ACROSS COLORADO ON
WEDNESDAY AFTERNOON. EXPECT ANOTHER ROUND SHOWERS AND
THUNDERSTORMS BY WEDNESDAY AFTERNOON WITH INITIAL DEVELOPMENT OVER
THE MOUNTAINS. AGAIN...ABUNDANT MOISTURE WILL LEAD TO AREAS OF
HEAVY RAINFALL UNDER STRONGER STORMS. MODELS PUSH THE ACTIVITY
EAST OFF THE MOUNTAINS AND ACROSS THE PLAINS WEDNESDAY EVENING AND
OVERNIGHT. THERE IS THE POTENTIAL OF ANOTHER MCS DEVELOPING...WITH
MODEL SOLUTIONS FOCUSING IT OVER THE FAR SOUTHEASTERN COUNTIES
WEDNESDAY NIGHT.
THURSDAY THROUGH SATURDAY...AN UPPER LEVEL LOW IS FORECAST TO
DEVELOP OVER THE PACIFIC NORTHWEST HELPING TO AMPLIFY AND DRAW THE
HIGH PRESSURE OVER THE SOUTHEAST CONUS TO THE WEST. THIS WILL
FORCE THE MAIN MOISTURE PLUME AND ENERGY IN THE SOUTHERLY FLOW TO
THE WEST. WEAK ENERGY MOVING THROUGH THE RIDGE WILL HELP BRING
AFTERNOON AND EVENING THUNDERSTORMS TO THE MOUNTAINS EACH DAY.
LOCALLY HEAVY RAINFALL WILL REMAIN POSSIBLE ALONG WITH GUSTY
OUTFLOW WINDS AND LIGHTNING. STEERING FLOWS ALOFT WILL REMAIN WEAK
AND EASTWARD PROGRESSION OFF THE MOUNTAINS LOOKS LIMITED TO THE
PALMER DIVIDE AND I-25 CORRIDOR DURING THE EVENING HOURS BEFORE
DISSIPATING WITH SUNDOWN.
SUNDAY AND MONDAY...MODELS BEGIN TO DIVERGE WITH HIGH ENSEMBLE
SPREADS AND LOWERED CONFIDENCE IN ANY SOLUTION. THE GFS BRINGS THE
PACIFIC NORTHWEST STORM SYSTEM ACROSS THE AREA SUNDAY INTO MONDAY.
THIS WOULD BRING MORE WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY
ALONG WITH COOLER TEMPERATURES TO THE REGION...ESPECIALLY ON
SUNDAY. THE ECMWF KEEPS THE PATTERN STATUS QUO...WITH THE UPPER
SYSTEM OVER THE PACIFIC NORTHWEST WEAKENING AND THE HIGH PRESSURE
REMAINING OVER TEXAS. THIS WOULD KEEP THE MAIN MOISTURE AND ENERGY
TO THE WEST...WITH CONTINUED DAILY AFTERNOON AND EVENING SHOWER
AND THUNDERSTORM ACTIVITY FOR THE MOUNTAINS...WITH LIMITED
MOVEMENT THROUGH THE EVENING. MOZLEY
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 235 PM MDT MON JUL 13 2015
VFR CONDITIONS CAN BE EXPECTED TONIGHT THROUGH TUESDAY. SHOWERS AND
TSTMS WL BE POSSIBLE IN THE VCNTY OF THE TERMINAL FORECAST SITES
THIS EVENING AND AGAIN TUESDAY AFTERNOON. IF TSTMS MOVE INTO THE
VCNTY...THERE WL BE THE POTENTIAL FOR MODERATE TO HEAVY RAIN TO
CAUSE BRIEF MVFR CONDITIONS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...28
LONG TERM...MOZLEY
AVIATION...28
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
314 PM MDT MON JUL 13 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 310 PM MDT MON JUL 13 2015
IN SW FLOW A WAVE PASSED LAST NIGHT LEAVING THE FORECAST AREA IN A
SUBSIDENT REGION THROUGH THE MORNING HOURS. PRECIPITABLE WATER
VALUES HAVE ALSO DIMINISHED A BIT THROUGH TODAY WITH NO FAVORABLE
GRADIENT AREAS OVER THE FORECAST AREA. NO ORGANIZED FORCING IS
SEEN FOR THIS LATE AFTERNOON OR OVERNIGHT SO CONVECTION WILL FIRE
OVER HIGHER TERRAIN AND POTENTIALLY DRIFT TO NEARBY VALLEYS TO THE
NE. HRRR SHOWS A QUICK DIMINISHING OF STORM COVERAGE WITH SUNSET
EXCEPT NEAR THE FOUR CORNERS TO SW SAN JUANS WHERE STORMS MAY
PERSIST TO AROUND MIDNIGHT.
TUESDAY...MOISTURE INCREASES A BIT FROM THE SOUTH AND FORCING
INCREASES AS THE RIGHT ENTRANCE QUADRANT OF THE JET PUSHES ACROSS
THE NORTHERN FORECAST AREA THROUGH THE AFTERNOON WITH RESULTING
LOW LEVEL CONVERGENCE DEVELOPING BY LATE AFTERNOON ALONG THE UT-
CO STATE LINE. THE RELATIVELY SLOW STORM MOTION...TO THE NE AT
10KTS...WILL LEAD TO POTENTIAL FLOODING CONCERNS FAVORING EASTERN
UTAH AND FAR WESTERN COLORADO UNDER THE BEST LATE AFTERNOON-
EVENING JET FORCING. SCATTERED STORMS AND SHOWERS ARE EXPECTED TO
PERSIST BEYOND MIDNIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 310 PM MDT MON JUL 13 2015
WEDNESDAY...THE WESTERN TROUGH PUSHES INTO THE GREAT BASIN
BRINGING A DRIER W-SW FLOW TO EASTERN UTAH. MOST AFTERNOON
SHOWERS AND STORMS WILL BE CONFINED TO WESTERN COLORADO. THE TREND
IS FOR LESS DRYING THAN PROGGED. THE DRYING TREND CONTINUES ON
THURSDAY WHICH MAY BE THE WARMEST DAY OF THE NEW WEEK.
PRECIPITABLE WATER VALUES FALL TO AROUND 0.5 INCH...SO ISOLATED
LATE-DAY STORMS WILL PRODUCE GUSTY WINDS AND LIGHTNING BUT LITTLE
RAIN.
THE NEXT MONSOONAL SURGE BEGINS LATE FRIDAY IN THE GFS WITH ITS
DEEPER WESTERN TROUGH. THE EC DELAYS THE SURGE UNTIL LATE
SATURDAY. SO FOR THIS FORECAST WE SHOWED A WETTER TREND FOR THOSE
DAYS WITH SUNDAY EXPECTED TO HAVE SIGNIFICANTLY MORE STORM
COVERAGE. THE WET PERIOD COULD INTO MONDAY WHEN THE EC BEGINS TO
PULL MOISTURE OFF OF HURRICANE DOLORES INTO THE NORTHERN FORECAST
AREA ACROSS THE TOP OF THE SUBTROPICAL HIGH. THE GFS KEEPS
DOLORES FURTHER OUT TO SEA PERHAPS PULLING MOISTURE INTO THE
NORTHERN CWA BY NEXT WEDNESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 310 PM MDT MON JUL 13 2015
SCATTERED LATE DAY STORMS TO HUG HIGHER TERRAIN AND VALLEY
LOCATIONS TO THE NE. THROUGH 05Z THIS EVENING KEGE KASE KTEX KDRO
HAVE A 40 PERCENT CHANCE OF -TSRA WITH ERRATIC OUTFLOW WINDS AND
CIGS BLO ILS BREAK POINTS. 04Z-18Z STORMS WILL BE ISOLATED AND
CIRCUMNAVIGABLE WITH PREVAILING VFR CONDITIONS. AFT 18Z TUESDAY
ALL TAF SITES HAVE A CHANCE OF -TSRA AND CIGS BLO ILS BREAK
POINTS.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...JOE
LONG TERM...JOE
AVIATION...JOE
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1055 PM EDT TUE JUL 14 2015
.SYNOPSIS...
A WARM FRONT REMAINS TO THE SOUTH OVERNIGHT...AS LOW PRESSURE
WILL BE APPROACHING LATE TONIGHT AND PASSES TO THE SOUTH
WEDNESDAY. THIS LOW MOVES SOUTHEAST OF LONG ISLAND WEDNESDAY NIGHT
AS A CANADIAN HIGH BUILDS IN FROM THE NORTHWEST. THIS HIGH
CONTINUES TO GRADUALLY BUILD CLOSER TO THE LOCAL REGION THROUGH
FRIDAY. A WARM FRONT WILL MOVE TOWARD THE AREA FRIDAY NIGHT INTO
SATURDAY MORNING AND REMAIN NEAR THE AREA THROUGH SATURDAY NIGHT.
THE WARM FRONT LIFTS WELL NORTH OF THE AREA SUNDAY NIGHT INTO
MONDAY. A COLD FRONT SLOWLY APPROACHES THE AREA FOR THE BEGINNING
OF THE NEW WORK WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
LATEST RADAR TRENDS 00Z NAM ALONG WITH LATEST RUC AND HRRR SUPPORT
EARLY CHANGE TO MAINLY DRY FORECAST FOR THE REMAINDER OF TONIGHT.
IT APPEARS THAT NEGATIVE VORTICITY ADVECTION AT 700-500 HPA WILL
BE THE DOMINATE PLAYER. THUS...HAVE REDUCED POPS LATE TONIGHT TO
20 PERCENT AND SCALED BACK TO ONLY W 1/4 OF CWA (MAINLY W OF
HUDSON). MIGHT SEE SOME SHOWERS MOVE INTO W ORANGE COUNTY
AROUND/JUST AFTER 6Z...HOWEVER CONFIDENCE IN THIS IS NOT HIGH AS
HRRR APPEARS TO HAVE OVERDONE INITIAL STRENGTH/COVERAGE OF THE
CONVECTION IT IS MOVING THERE.
LOWS GENERALLY ON TRACK...WITH MAINLY UPPER 60S N TO LOWER 70S S.
UPDATED WITH BLEND OF 00Z NAM 2-METER TEMPERATURES 18Z MAV
GUIDANCE 1Z LAV AND 12Z MET GUIDANCE.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
THERE ARE SOME INDICATIONS THAT PRECIPITATION MAY NOT DEVELOP
UNTIL LATER WEDNESDAY MORNING THAN CURRENTLY FORECAST. WILL WAIT
FOR ENTIRE 00Z SUITE TO COME IN BEFORE CHANGING FORECAST.
WEDNESDAY...A VERY ACTIVE DAY IN TERMS OF CONVECTION ESPECIALLY
BY MIDDAY. MORE ELEVATED INSTABILITY EXISTS EARLY WITH THE WARM
AND MOIST AIR ADVECTION WITH THE NOSE OF THE LOW LEVEL JET WITHIN
THE REGION. THE LOW LEVEL JET EXITS BY THE AFTERNOON AND THEN WITH
A LIGHT NE FLOW AT THE SURFACE...THERE WILL BE SOME LINGERING
SHOWERS AND THUNDERSTORMS...BUT WOULD EXPECT THE THUNDERSTORMS TO
BE WIDELY SCATTERED AT THAT POINT.
LAYER PRECIPITABLE WATERS WILL BE LOWERING FROM NW TO SE LATER BY
WEDNESDAY EVENING. SHOWERS WILL TAPER OFF FROM NW TO SE WEDNESDAY
NIGHT.
FOR HIGHS WEDNESDAY...CHOSE RELATIVELY COOLER MET/ECS GUIDANCE AND
LOWS WEDNESDAY NIGHT...CHOSE THIS BLEND AGAIN.
FOR THURSDAY THROUGH FRIDAY...A MORE QUIET AND TRANQUIL WEATHER
PATTERN IS CONVEYED BY THE MORE ZONAL FLOW GETTING ESTABLISHED IN
THE MID LEVELS WITH OVERALL...RIDGING IN MID TO UPPER LEVELS. AT
THE SURFACE...HIGH PRESSURE WILL GRADUALLY BUILD IN FROM THE GREAT
LAKES AND SOUTHEAST CANADA. DEWPOINTS WILL TREND LOWER...MAINLY IN
THE 50S...SO A MUCH LESS HUMID AIRMASS WILL BE ENTERING THE AREA.
FOR TEMPERATURES...USED MOSTLY ECE GUIDANCE WITH SOME BLENDING OF
GMOS FOR THURSDAY NIGHT AND FRIDAY.
THERE IS A MODERATE RISK FOR THE METEOROLOGICAL ENHANCEMENT OF RIP
CURRENT DEVELOPMENT AT ATLANTIC BEACHES WEDNESDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
ZONAL FLOW ALOFT FRIDAY NIGHT WILL BE REPLACED BY A WEAK SHORTWAVE
THAT WILL MOVE ACROSS THE NORTHEAST FRIDAY NIGHT INTO SATURDAY
NIGHT. THEREAFTER...AN UPPER LEVEL LONGWAVE TROUGH WILL APPROACH
FROM THE MID-WEST AND GREAT LAKES REGION INTO THE BEGINNING OF THE
NEW WORK WEEK. THERE IS UNCERTAINTY WITH THE AMPLITUDE OF THIS
TROUGH AS THE 12Z ECMWF IS MUCH MORE AMPLIFIED THAN THE 12Z GFS.
THIS WILL FEED INTO THE UNCERTAINTY WITH THE SURFACE FEATURES
THROUGH THIS TIME PERIOD.
AT THE SURFACE...A WARM FRONT WILL LIFT TOWARD THE REGION FRIDAY
NIGHT...AND REMAIN NEAR THE AREA SUNDAY MORNING. THE WARM FRONT
WILL THEN LIFT WELL NORTH OF THE AREA SUNDAY INTO SUNDAY NIGHT.
THEREAFTER...THE ASSOCIATED COLD FRONT WILL APPROACH INTO THE
BEGINNING OF THE NEW WORK WEEK. THE MORE AMPLIFIED UPPER LEVEL
TROUGH IN THE 12Z ECMWF MOVES THE COLD FRONT FASTER THAN THE LESS
AMPLIFIED 12Z GFS. GIVEN THE LARGE UNCERTAINTY...WILL SIDE HEAVILY
ON WPC IN THIS TIME FRAME.
SEASONABLE...BUT WARMING TEMPERATURES THROUGH THE PERIOD AS THE WARM
FRONT INTRODUCES A WARM AND HUMID AIRMASS...WITH THE AREA ALSO BEING
WARM SECTORED FOR SUNDAY AND MONDAY.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
A WARM FRONT JUST SW OF THE NYC METRO TERMINALS IS EXPECTED TO
REMAIN NEARLY STATIONARY THROUGH TONIGHT AS LOW PRES OVER THE
EASTERN GREAT LAKES TRACKS SOUTHEAST TO THE SRN NJ COAST BY
MORNING. THIS LOW WILL THEN CONTINUE EWD ON WED.
AS OF 02Z...WARM FRONT HASN`T MOVED MUCH EXTENDING IN A LINE FROM
JUST N OF KBLM TO KUNV AND UP INTO LAKE ERIE. AM EXPECTING THIS
BOUNDARY TO REMAIN NEARLY STATIONARY TONIGHT AS LOW PRES OVER LAKE
ERIE TRACKS SE. AS SUCH...HAVE GONE AGAINST MUCH OF THE GUIDANCE
WHICH APPEARS TO HAVE LIFTED THE FRONT THROUGH OR DOES SO IN THE
NEXT COUPLE OF HOURS. HIGH BUST POTENTIAL IF THE FRONT DOES END UP
LIFTING THROUGH WITH PERHAPS ONLY MARGINAL CONDS AT WORST
OVERNIGHT.
SHRA/TSTM ACTIVITY IN CENTRAL PA IS TRACKING NE AND SHOULD NOT
IMPACT ANY OF THE TERMINALS. OUTSIDE OF A STRAY SHOWER/TSTM
OVERNIGHT WITH THE FRONT IN THE AREA...EXPECT DRY CONDS UNTIL
MORNING. 00Z GUIDANCE CONTINUES TO SUPPORT ACTIVITY DEVELOPING
AFT 12Z...SO HAVE PUSHED THIS BACK. TSTMS ALSO POSSIBLE...BUT TOO
FAR OUT TO INCLUDE IN THE TAFS AND WOULD LIKE TO GET A BETTER
HANDLE ON TIMING OF PCPN FIRST.
MODERATE TO HIGH CONFIDENCE IN WINDS.
.OUTLOOK FOR 00Z WED THROUGH SAT...
.WED NIGHT...VFR CONDS RETURNING IN THE EVE.
.THU-FRI...VFR.
.SAT...MVFR OR LOWER POSSIBLE IN SCT SHRA/TSRA.
&&
.MARINE...
MADE MINOR CHANGES THIS UPDATE. THE FORECAST APPEARS ON TRACK.
SUB SCA CONDITIONS ARE EXPECTED TO CONTINUE ACROSS ALL WATERS
WITH A RELATIVELY WEAK PRESSURE GRADIENT IN PLACE THROUGH TONIGHT.
A SE SWELL BUILDING WEDNESDAY WILL EVENTUALLY LEAD TO HIGHER SEAS
IN ADDITION TO THE CONTINUED SOUTHERLY FETCH FOR WEDNESDAY
AFTERNOON...FROM EAST TO WEST. WESTERN OCEAN WILL NOT GET TO SCA
RANGE UNTIL WEDNESDAY EVENING. OVERALL...PRESSURE GRADIENT
INCREASE BEHIND THE LOW WEDNESDAY NIGHT AND NORTHERLY WINDS WILL
INCREASE TO 15-23 KT WITH GUSTS A FEW KT HIGHER. SCA MORE
PROBABLE FOR BOTH WINDS AND SEAS WEDNESDAY NIGHT ACROSS ALL OCEAN.
THESE SCA OCEAN CONDITIONS MAY POTENTIALLY CONTINUE INTO THURSDAY
AND THURSDAY EVENING BUT WITH SOME UNCERTAINTY...DID NOT WANT TO
EXTEND SCA YET. THE SEAS WILL BE MAIN DETERMINANT HERE.
SUB SCA CONDITIONS EXPECTED LATE THURSDAY NIGHT AND FRIDAY WITH A
WEAK PRESSURE GRADIENT WITH HIGH PRESSURE TAKING CONTROL.
NON OCEAN WATERS EXPECTED TO STAY MOSTLY BELOW SCA THROUGH FRIDAY.
WINDS AND WAVES SHOULD REMAIN BELOW SCA CRITERIA FROM FRIDAY NIGHT
THROUGH THE END OF THE LONG TERM.
&&
.HYDROLOGY...
A BASIN AVERAGE OF 1/2-3/4 INCH OF RAINFALL THROUGH WEDNESDAY
NIGHT. DUE TO THE CONVECTIVE NATURE AND RELATIVELY SLOW FORWARD
MOTION OF SHOWERS DURING THIS PERIOD...FAIRLY LARGE DEVIATIONS
FROM THIS AVERAGE WILL PROBABLY OCCUR. PINPOINTING LOCATIONS THAT
WILL RECEIVE THE GREATEST AMOUNTS...AND HOW MUCH ABOVE THE BASIN
AVERAGE THOSE LOCATIONS WOULD RECEIVE IS DIFFICULT WITH THIS
SETUP.
WHAT IS SOMEWHAT MORE CERTAIN IS THAT THE BETTER CHANCES OF
WIDESPREAD RAINFALL ACROSS THE TRI STATE AREA OCCUR LATE TONIGHT
AND WEDNESDAY. THERE WILL PROBABLY BE A FEW AREAS OF MINOR
URBAN/SMALL STREAM/POOR DRAINAGE FLOODING...BUT CONFIDENCE IN A
WIDESPREAD FLASH FLOODING SCENARIO IS TOO LOW TO GO WITH ANY WATCH
AT THIS TIME. WITH THAT SAID...LOCALIZED FLASH FLOODING WILL BE
POSSIBLE AT ANY TIME TODAY THROUGH WEDNESDAY AFTERNOON.
NO HYDROLOGIC PROBLEMS EXPECTED WEDNESDAY NIGHT THROUGH THE END OF
THE WEEK.
SCATTERED SHOWERS AND THUNDERSTORMS ARE IN THE FORECAST FOR THE
WEEKEND AND EARLY NEXT WEEK. A WIDESPREAD RAINFALL IS NOT EXPECTED.
ANY SLOW MOVING SHOWER OR THUNDERSTORM COULD PRODUCE HEAVY RAIN WITH
ISOLATED FLOODING.
&&
.TIDES/COASTAL FLOODING...
SOME TIDAL LOCATIONS ALONG WESTERN LONG ISLAND SOUND AND SOUTH
SHORE BAYS WILL PROBABLY TOUCH MINOR BENCHMARKS WITH THE CONTINUED
SOUTHEAST FETCH DURING HIGH TIDES OVERNIGHT.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 PM WEDNESDAY TO 6 AM EDT THURSDAY
FOR ANZ355.
SMALL CRAFT ADVISORY FROM 2 PM WEDNESDAY TO 6 AM EDT THURSDAY
FOR ANZ350-353.
&&
$$
SYNOPSIS...MALOIT/JM/JP
NEAR TERM...MALOIT
SHORT TERM...MALOIT/JM
LONG TERM...JP
AVIATION...24
MARINE...MALOIT/JM/JP
HYDROLOGY...MALOIT/JM/JP
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS ALBANY NY
1018 PM EDT TUE JUL 14 2015
.SYNOPSIS...
A DISTURBANCE WILL WORK ACROSS OUR REGION WITH SCATTERED SHOWERS
AND POSSIBLY THUNDERSTORMS TONIGHT. THEN A STRONG COLD FRONT WILL
SLIDE THROUGH REGION TOWARD DAYBREAK. A WAVE MIGHT FORM ALONG THIS
FRONT SLOWING IT DOWN TO OUR SOUTH. MORE SHOWERS ARE LIKELY
THROUGH EARLY WEDNESDAY. CANADIAN HIGH PRESSURE WILL BRING A
RETURN TO DRY WEATHER LATE WEDNESDAY THROUGH FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 1015 PM EDT...WIDELY SCATTERED CONVECTION ACROSS THE DACKS
WITH A MORE ORGANIZED CONVECTION ALONG THE COLD FRONT NEAR ST
LAWRENCE VALLEY/LAKE ONTARIO. A MORE CONCENTRATED AREA OF
CONVECTION REMAINS INTACT APPROACHING THE CATSKILLS BUT WEAKENING.
THE REMAINDER OF THE OVERNIGHT...PER THE HRRR AND RAP13...THIS
ACTIVITY SHOULD CONTINUE TO WEAKEN BUT NOT COMPLETE DISSIPATE.
HOWEVER...WE KEPT SCT-CHC POPS ACROSS THE REGION. A MUGGY NIGHT
WITH DEWPOINTS WELL INTO THE 60S TO NEAR 70F WHERE SOME PATCHY FOG
AND/OR LOW STRATUS WILL DEVELOP. SO OVERNIGHT LOWS GENERALLY IN
THE 60S...WITH A FEW UPPER 50S ACROSS THE ADIRONDACK PARK WITH THE
TIMING OF THE FRONTAL PASSAGE.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
BY EARLY WEDNESDAY...THE SURFACE COLD FRONT SHOULD HAVE SLIPPED SOUTH
OF I-90. HOWEVER...THE UPPER LEVEL TROUGH MIGHT LAG A LITTLE
BEHIND...KEEPING THINGS UNSETTLED INITIALLY...EVEN NORTH OF THE
FRONT. THE DAY WILL START WITH PLENTY OF CLOUDS AND CHANCES FOR
SHOWERS FROM ALBANY NORTH...WHILE FURTHER SOUTH SHOWERS WILL BE LIKELY
WITH STILL THE CHANCE FOR THUNDERSTORMS.
BY MIDDAY...CLOUDS SHOULD BEGIN TO CLEAR IN OUR NORTHERN AREAS...REACHING
IN THE CAPITAL REGION DURING THE AFTERNOON. IT MIGHT REMAIN MOSTLY
CLOUDY WITH RESIDUAL SHOWERS AND POSSIBLY ANOTHER THUNDERSTORM IN
OUR SOUTHERN AREAS MUCH OF THE AFTERNOON.
BASED ON UPSTREAM OBS AND LOTS OF CLOUDS TOMORROW...IT WILL TURN
NOTICEABLY COOLER BEHIND THE FRONT WITH A NORTHERLY BREEZE KICKING
IN. WHILE NOT GOING AS LOW AS THE MET GUIDANCE WE ACTUALLY SIDED A
LITTLE MORE WITH IT...THAN THE WARMER MAV NUMBERS. THAT MEANS HIGHS WILL
ONLY REACH AROUND 70 IN OUR NORTHERN ZONES (DESPITE SEEING SOME
CLEARING EARLIER)...MID 70S CAPITAL REGION AND NEAR 80 SOUTH WHERE
THE FRONT AGAIN WILL BE LAST TO CLEAR. DEWPOINTS LOOK TO PLUNGE TO
THE 40S NORTH AND WEST OF ALBANY DURING THE AFTERNOON...50S LOCALLY IN THE
CAPITAL REGION. TO THE SOUTH...DEWPOINTS STARTING OUT NEAR 70...WILL
BE TRIMMED BACK TO THE 60S BY LATE IN THE DAY.
A NORTHERLY BREEZE WILL KICK IN AROUND 10 MPH...BUT COULD GUST OVER
20 MPH AT TIMES.
BY WEDNESDAY NIGHT...A MUCH DRIER AIRMASS WILL WORK IN
EVERYWHERE...CLEARING THE SKY AND MAKING FOR A REFRESHINGLY COOLER
NIGHT. A LIGHT NORTH BREEZE WILL CONTINUE IN MOST AREAS. OVERNIGHT
LOWS LOOK TO DROP INTO THE LOWER TO MID 50S ACROSS MOST AREAS...BUT
DOWN INTO THE MID TO UPPER 40S ACROSS OUR NORTHERN AREAS.
THURSDAY LOOKS LIKE A BEAUTIFUL DAY WITH A FEW CU FORMING. OTHERWISE
IT WILL BE SUNNY WITH RATHER LOW HUMIDITY (DEWPOINTS FROM THE MID
40S TO LOWER 50S) AND HIGH TEMPERATURES 75-80 IN THE VALLEYS...70-75
HIGHER TERRAIN.
THURSDAY NIGHT HIGH PRESSURE WILL CREST OVER THE REGION BRINGING
ANOTHER MAINLY CLEAR AND COOL NIGHT. LOOK FOR LOWS AGAIN LOWER TO
MID 50S ALBANY SOUTH...MID TO UPPER 40S MOST OTHER AREAS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE EXTENDED FORECAST OPENS WITH DRY WEATHER TO CLOSE THE
WORK WEEK...AS A SFC ANTICYCLONE DRIFTS EAST OF NEW ENGLAND BY THE
AFTERNOON. THE CLOSED H500 ANTICYCLONE CONTINUES TO BE CENTERED
NEAR TX...AND THE LOWER MS RIVER VALLEY. THE NRN PERIPHERY OF THE
MID LEVEL RIDGE CONTINUES TO HAVE FLAT RELATIVELY FAST FLOW ALOFT AS
WE ENTER THE WEEKEND. A LOW PRESSURE SYSTEM WILL BE MOVING ACROSS
THE UPPER MIDWEST AND WRN GREAT LAKES REGION FRIDAY AFTERNOON. A
WARM FRONT EXTENDING EAST/SOUTHEAST OF THE WAVE WILL ALLOW MID AND
HIGH CLOUDS TO INCREASE FROM THE WEST LATE IN DAY...AND INTO THE
NIGHT PERIOD. THE GFS/ECMWF/WPC GUIDANCE CONTINUE TO HAVE SOME
ISOLD-SCT SHOWERS AND PERHAPS SOME ISOLD THUNDERSTORM INCREASING
FROM WEST TO EAST OVER THE FCST AREA...ESPECIALLY AFTER MIDNIGHT DUE
TO THE WEAK ISENTROPIC LIFT AHEAD OF THE BOUNDARY. THE BETTER CHC
OF SHOWERS AND ISOLD THUNDERSTORMS LOOKS TO BE NORTH AND WEST OF THE
CAPITAL DISTRICT AND MID HUDSON VALLEY. HIGHS ON FRIDAY WILL BE IN
THE U70S TO L80S IN THE VALLEY AREAS...AND 70S OVER THE MTNS. LOWS
FRI NIGHT WILL RANGE FROM THE MID 50S TO L60S OVER THE FCST AREA.
SAT-SAT NIGHT...THE FIRST WEAK SFC LOW LIFTS NORTH AND EAST OF THE
REGION...AND THE WARM FRONT MAY LIFT NORTH OF MOST OF THE FCST AREA.
IN THE WARM SECTOR...SFC DEWPTS MAY GET WELL INTO THE 60S. MODERATE
AMOUNTS OF SFC BASED INSTABILITY MAY SET UP OVER THE FCST AREA IF
ENOUGH HEATING OCCURS. THE LATEST GFS HAS SBCAPES OF 1000-2000 J/KG
FROM ABOUT THE HUDSON RIVER VALLEY WESTWARD BY 00Z/SUN. SOME STRONG
THUNDERSTORMS WITH HEAVY RAINFALL WILL BE POSSIBLE AS PWATS MAY RISE
A STANDARD DEVIATION OR SO ABOVE NORMAL. CHANCES OF SHOWERS AND
THUNDERSTORMS ARE POSSIBLE ESPECIALLY SATURDAY AFTERNOON INTO THE
EARLY EVENING WITH HIGHS IN THE M70S TO L80S OVER THE FCST AREA.
EXPECTING THE SHOWERS AND THUNDERSTORMS TO DECREASE OVERNIGHT WITH
MUGGY CONDITIONS WITH LOWS IN THE 60S. THE WEAK SYSTEM LIFTS NORTH
AND EAST...AND THE COLD FRONT LOOKS TO WASH OUT NEAR THE FCST AREA.
SUNDAY INTO TUESDAY...THE H500 RIDGE CENTERED OVER THE SRN
PLAINS/SOUTHEAST MAY AMPLIFY A BIT AS WE CLOSE THE WEEKEND. THIS
WILL ALLOW THE OLD COLD FRONT TO MOVE BACK NORTH AND EAST OF UPSTATE
NY AND NEW ENGLAND AS A WARM FRONT. THE ECMWF ACTUALLY SHOWS A
RELATIVELY DRY SUNDAY...WITH THE NEXT DISTURBANCE APPROACHING FROM
THE GREAT LAKES REGION. THE GFS/CMC/ENSEMBLES AND WPC GUIDANCE
INDICATE MORE SHOWERS AND THUNDERSTORMS MAY OCCUR ALONG AND BEHIND
THE WARM FRONT. A CHC OF SHOWERS AND THUNDERSTORM WAS KEPT IN THE
FCST TO CLOSE THE WEEKEND. TEMPS MAY NUDGE A TAD ABOVE NORMAL WITH
MID AND U80S IN THE VALLEYS...AND U70S TO L80S OVER THE HIGHER
PEAKS. SCATTERED SHOWERS PERSIST INTO THE EARLY EVENING...AS
A STICKY AIR MASS CONTINUES OVER THE FCST AREA.
MONDAY MAY FEATURE AIR MASS OR DIFFERENTIAL HEATING ISOLD-SCT
THUNDERSTORMS TIED TO THE PEAK DIURNAL HEATING WELL IN ADVANCE OF
THE NEXT SYSTEM APPROACHING FROM THE GREAT LAKES REGION. IT MAY NOT
BE A COMPLETE WASHOUT. A PROGRESSIVE NRN STREAM TROUGH WILL BE
MOVING OVER THE NRN GREAT LAKES REGION AND S-CNTRL ONTARIO MON NIGHT
INTO TUESDAY. THERE IS A BETTER CHC OF SCT SHOWERS AND
THUNDERSTORMS AHEAD OF THE COLD FRONT AND A PREFRONTAL SFC TROUGH.
SOME HEAVY LOCALLY HEAVY RAINFALL WILL BE POSSIBLE WITH PWATS
POTENTIALLY 1-2 STD DEVS ABOVE NORMAL ON THE GEFS AS WE HEAD INTO
EARLY NEXT WEEK. HIGHS AND LOWS STILL LOOK A LITTLE ABOVE NORMAL AS
WE MOVE INTO EARLY NEXT WEEK.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
EXTREMELY CHALLENGING SET OF TAFS AS ALL LOCATIONS ARE CURRENTLY
VFR. STRATUS WILL LIKELY RESULT IN A PERIOD OF MVFR AT KPOU AS
DEWPOINTS HERE WERE NEAR 70F WITH A LIGHT ESE WIND. LATER
TONIGHT...COMBINATION OF MOIST LOW LEVELS AND THE CHANCE FOR
ADDITIONAL SHOWERS FROM ACTIVITY ACROSS CENTRAL NY AND ALONG THE
COLD FRONT NORTH OF THE U.S. BORDER...WE WILL PLACE TEMPO GROUPS
FOR MVFR CONDITIONS THROUGH THE LATE EVENING AND EARLY OVERNIGHT.
THEN FLIGHT CONDITION SHOULD REMAIN WITHIN MVFR THRESHOLDS /OR BE
VERY CLOSE/ OVERNIGHT WITH THE CONTINUED THREAT FOR MORE SHOWERS.
COLD FRONT APPROACHING WEDNESDAY MORNING WITH ADDITIONAL ROUND FOR
CONVECTION YET OVERALL COVERAGE REMAINS IN QUESTION AS WE WILL
PLACE A VCSH AS WE CONTINUE TO WATCH TRENDS UNFOLD WEDNESDAY.
LIGHT SOUTHERLY WINDS THIS EVENING WILL LIKELY BECOME LIGHT AND
VARIABLE OVERNIGHT. THEN A SHIFT TOWARD A NORTHERLY DIRECTION
WEDNESDAY MORNING WITH THE FRONTAL PASSAGE AND AN INCREASE IN
MAGNITUDES TOWARD 10 KTS.
OUTLOOK...
WEDNESDAY THROUGH FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SATURDAY THROUGH SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF
SHRA...TSRA.
&&
.FIRE WEATHER...
MOST AREAS SHOULD SEE SOME SHOWERS AND POSSIBLY A
THUNDERSTORM TONIGHT INTO EARLY WEDNESDAY WITH AVERAGE RAINFALL
GENERALLY A QUARTER INCH OR MORE...WHILE SOME AREAS LOCALLY RECEIVING UP TO
AN INCH OR MORE.
A COOLER DRIER CANADIAN AIR MASS WILL BEGIN TO TAKE HOLD LATER
WEDNESDAY AND ESPECIALLY WEDNESDAY NIGHT. DRY WEATHER IS
EXPECTED THURSDAY AND FRIDAY. TEMPERATURES WILL BE A LITTLE LOWER
THAN NORMAL ON THURSDAY...TRENDING TOWARD SEASONAL ON FRIDAY.
THE NEXT CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE SATURDAY.
&&
.HYDROLOGY...
A BROAD AREA OF LOW PRESSURE WILL MOVE SLOWLY EASTWARD ACROSS THE
REGION THROUGH WEDNESDAY. IN THE MEANTIME...A COLD FRONT WILL
APPROACH FROM THE NORTHWEST AND WILL CROSS THE REGION WEDNESDAY.
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL OCCUR AS THESE
FEATURES MOVE ACROSS THE REGION.
AVERAGE BASIN RAINFALL AMOUNTS WILL BE FROM A QUARTER TO THREE QUARTERS OF AN INCH...
BUT THERE WILL BE LOCALIZED AREAS POSSIBLY EXCEEDING AN INCH.
WITH PWATS MAXING OUT BETWEEN 1.5-2 INCHES...ANY SHOWER OR THUNDERSTORM
COULD PRODUCE ENOUGH RAINFALL TO PRODUCE LOCALIZED
PONDING OF WATER ON ROADWAYS PERHAPS EVEN SOME URBAN FLOODING.
DRIER WEATHER RETURNS LATER WEDNESDAY INTO FRIDAY WITH THE NEXT CHANCE OF SHOWERS
AND THUNDERSTORMS RETURNING ON SATURDAY.
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.
&&
.EQUIPMENT...
OUR RADAR /KENX/ IS DOWN UNTIL WEDNESDAY AFTERNOON...AND
EMERGENCY PARTS ARE ON ORDER. WE APOLOGIZE FOR THE INCONVENIENCE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV/BGM
NEAR TERM...HWJIV/BGM
SHORT TERM...HWJIV
LONG TERM...WASULA
AVIATION...SND/HWJIV
FIRE WEATHER...HWJIV
HYDROLOGY...IAA/HWJIV
EQUIPMENT...BGM
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS ALBANY NY
155 PM EDT MON JUL 13 2015
.SYNOPSIS...
HIGH PRESSURE OVER THE REGION WILL WEAKEN TODAY AS A DISTURBANCE
IN THE UPPER LEVELS OF THE ATMOSPHERE APPROACHES FROM THE GREAT
LAKES. AS A RESULT...THERE IS A CHANCE OF SHOWERS AND
THUNDERSTORMS THIS AFTERNOON INTO THE EARLY EVENING. THE CHANCE
FOR SHOWERS AND STORMS CONTINUES TUESDAY THROUGH WEDNESDAY AS A
COLD FRONT APPROACHES FROM THE NORTHWEST AND CROSSES THE AREA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BAND OF CLOUDINESS ACROSS THE CENTRAL PART OF THE FORECAST AREA
ASSOCIATED WITH UPPER LEVEL TROUGH. REST OF AREA GENERALLY SUNNY.
ADJUSTED CLOUD COVER TO BE IN LINE WITH CURRENT SATELLITE IMAGE.
CLOUDS WILL INCREASE ACROSS THE FORECAST AREA AS HAZY...HOT AND
HUMID CONDITIONS WILL DEVELOP.
CURRENT TEMPERATURES IN 70S TO NEAR 80 DEGREES. WINDS ARE LIGHT
AND FROM THE SOUTHEAST. MODELS INDICATE WINDS WILL INCREASE FROM
THE SOUTH-SOUTHEAST LATER TODAY AND BECOME BREEZY.
LATEST HRRR SHOWS SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING
AFTER NOON WITH GREATEST COVERAGE ACROSS THE TACONICS...SOUTHERN
VERMONT...BERKSHIRE COUNTY MA AND THE CATSKILLS. ALSO A FEW
ISOLATED CELLS EXPECTED OVER THE ADIRONDACKS THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
THE UPPER LEVEL DISTURBANCE WILL PASS TO OUR SOUTH AND WEST
TUESDAY NIGHT INTO WEDNESDAY. GUIDANCE KEEPS THE UPPER LEVEL
TROUGH POSITIVELY TILTED AND PROGRESSIVE. A COLD FRONT WILL ALSO
APPROACH AND IS EXPECTED TO CROSS THE REGION WEDNESDAY AFTERNOON
AND NIGHT. THIS WILL RESULT IN CHANCES STORMS TUESDAY THROUGH
WEDNESDAY. NO STRONG FORCING WILL BE PRESENT SO STORMS ARE NOT
EXPECTED TO BE STRONG OR SEVERE. THE STORM PREDICTION CENTER ONLY
HAS THE LOCAL AREA UNDER A GENERAL THUNDERSTORMS OUTLOOK.
GUIDANCE DOES INDICATE PWATS VALUES WILL RISE TO 1.5+ INCHES
TUESDAY NIGHT INTO WEDNESDAY AHEAD OF THE COLD FRONT...SO STORMS
WILL BE CAPABLE OF PRODUCING HEAVY DOWNPOURS WHICH COULD CAUSE
SOME URBAN AND POOR DRAINAGE FLOODING. WILL CONTINUE TO H8IGHLIGHT
THIS IN OUR HAZARDOUS WEATHER OUTLOOK.
SEASONABLY WARM TEMPERATURES ARE EXPECTED BOTH TUESDAY AND
WEDNESDAY. TUESDAY NIGHT WILL BE A MILD AND MUGGY NIGHT. HOWEVER
WITH THE PASSAGE OF THE COLD FRONT DRIER AIR WILL BE FILTERED IN
ON A NORTHERLY FLOW FOR WEDNESDAY NIGHT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
HIGH PRESSURE WILL BE SITUATED OVER THE REGION TO START THE LONG
TERM PERIOD FOR THURSDAY INTO FRIDAY. SKIES WILL BE PARTLY TO MOSTLY
CLEAR WITH NO PRECIP EXPECTED. HIGHS LOOK TO BE IN THE LOW TO MID
80S FOR VALLEY AREAS...AND LOWS WILL BE IN THE 50S FOR THURSDAY
NIGHT...AND 60S FOR FRIDAY NIGHT.
WITH STRONG RIDGING ESTABLISHING ITSELF OVER THE CENTRAL US...THE
NORTHEAST WILL BE SITUATED WITHIN NORTHWEST FLOW ALOFT. THIS WILL
ALLOW A SERIES OF WEAK UPPER LEVEL DISTURBANCES TO MOVE TOWARDS THE
REGION FROM SOUTHERN CANADA. THE TIMING OF THESE SUBTLE FEATURES IS
STILL UNKNOWN...BUT EACH DISTURBANCE WILL ALLOW A CHANCE FOR SOME
SCATTERED SHOWERS AND THUNDERSTORMS...ESP WITHIN PEAK DAYTIME
HEATING OF AFTN INTO THE EARLY EVENING HOURS. POPS START TO RISE
FOR LATE FRIDAY NIGHT...AND WILL ALLOW FOR CHC POPS ON BOTH
SAT/SUNDAY. IT LOOKS LIKE THESE CONDITIONS WILL CONTINUE INTO
EARLY NEXT WEEK AS WELL. IT WON/T BE A WASHOUT BY ANY MEANS...BUT
CAN/T RULE OUT THESE SHOWERS AND THUNDERSTORMS THANKS TO THE
PASSING SHORTWAVE ALOFT.
MAX TEMPS OVER THE WEEKEND WILL GENERALLY BE IN THE MID 80S...WITH
MID 60S FOR LOW TEMPS. IT WILL BE FAIRLY MUGGY AS WELL...WITH
DEWPOINTS WELL INTO THE 60S.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
MAINLY VFR CONDITIONS EXPECTED AT THE TAF SITES THROUGH 18Z
WEDNESDAY.
RADAR SHOWS SHOWERS AND THUNDERSTORMS OVER THE HIGHER
TERRAIN SURROUNDING THE TAF SITES THIS AFTERNOON. SOME SHOWERS
AND AN ISOLATED THUNDERSTORM ARE POSSIBLE NEAR THE TAF SITES THIS
AFTERNOON. COVERED THIS IN TAFS WITH VCTS.
MODEL SOUNDING SHOW MORNING FOG AND SOME LOW CLOUDS DEVELOPING AT
ALL TAF SITES A COUPLE OF HOURS BEFORE SUNRISE ON TUESDAY...AND
LASTING A FEW HOURS. FOG/LOW CLOUDS SHOULD BURN OFF BY 13Z TUESDAY.
WINDS FORECAST TO BE FROM THE SOUTH TO SOUTHEAST AT 10-15 KTS TODAY.
WINDS BECOMING LIGHT AND VARIABLE TONIGHT...BEFORE INCREASING TO
10 TO 15 KTS FROM THE SOUTH TO SOUTHEAST ON TUESDAY.
OUTLOOK...
TUESDAY NIGHT THROUGH WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE
OF SHRA...TSRA.
WEDNESDAY NIGHT THROUGH FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT THROUGH SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF
SHRA...TSRA.
&&
.FIRE WEATHER...
HIGH PRESSURE OVER THE REGION WILL WEAKEN TODAY AS A DISTURBANCE
IN THE UPPER LEVELS OF THE ATMOSPHERE APPROACHES FROM THE GREAT
LAKES REGION. AS A RESULT WILL BE CHANCES FOR SHOWERS AND
THUNDERSTORMS THIS AFTERNOON INTO THE EARLY EVENING. WE WILL
HAVE CHANCES FOR STORMS TUESDAY THROUGH WEDNESDAY AS A COLD
FRONT ALSO APPROACHES AND CROSSES THE AREA.
&&
.HYDROLOGY...
THERE ARE CHANCES FOR SHOWERS AND THUNDERSTORMS THIS AFTERNOON
INTO EARLY EVENING AS AN UPPER LEVEL DISTURBANCE APPROACHES FROM
THE GREAT LAKES REGION TODAY. THE DISTURBANCE WILL PASS TO OUR
SOUTH AND WEST TUESDAY NIGHT INTO WEDNESDAY AND A COLD FRONT WILL
APPROACH AND CROSS THE REGION RESULTING IN CHANCES STORMS TUESDAY
THROUGH WEDNESDAY. MODELS INDICATE PWATS VALUES WILL RISE TO 1.5+
INCHES TUESDAY NIGHT INTO WEDNESDAY AHEAD OF THE COLD FRONT...SO
STORMS WILL BE CAPABLE OF PRODUCING HEAVY DOWNPOURS WHICH COULD
CAUSE SOME URBAN AND POOR DRAINAGE FLOODING.
MAINLY DRY WEATHER IS EXPECTED THURSDAY AND FRIDAY WITH OUR NEXT
CHANCES FOR STORMS COMING OVER THE WEEKEND AS A SERIES OF WEAK
UPPER LEVEL DISTURBANCES APPROACH AND CROSS THE REGION.
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...IAA
NEAR TERM...IAA/SND
SHORT TERM...IAA
LONG TERM...FRUGIS
AVIATION...SND
FIRE WEATHER...IAA
HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS ALBANY NY
1028 AM EDT MON JUL 13 2015
.SYNOPSIS...
HIGH PRESSURE OVER THE REGION WILL WEAKEN TODAY AS A DISTURBANCE
IN THE UPPER LEVELS OF THE ATMOSPHERE APPROACHES FROM THE GREAT
LAKES. AS A RESULT...THERE IS A CHANCE OF SHOWERS AND
THUNDERSTORMS THIS AFTERNOON INTO THE EARLY EVENING. THE CHANCE
FOR SHOWERS AND STORMS CONTINUES TUESDAY THROUGH WEDNESDAY AS A
COLD FRONT APPROACHES FROM THE NORTHWEST AND CROSSES THE AREA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BAND OF CLOUDINESS ACROSS THE CENTRAL PART OF THE FORECAST AREA
ASSOCIATED WITH UPPER LEVEL TROUGH. REST OF AREA GENERALLY SUNNY.
ADJUSTED CLOUD COVER TO BE IN LINE WITH CURRENT SATELLITE IMAGE.
CLOUDS WILL INCREASE ACROSS THE FORECAST AREA AS HAZY...HOT AND
HUMID CONDITIONS WILL DEVELOP.
CURRENT TEMPERATURES IN 70S TO NEAR 80 DEGREES. WINDS ARE LIGHT
AND FROM THE SOUTHEAST. MODELS INDICATE WINDS WILL INCREASE FROM
THE SOUTH-SOUTHEAST LATER TODAY AND BECOME BREEZY.
LATEST HRRR SHOWS SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING
AFTER NOON WITH GREATEST COVERAGE ACROSS THE TACONICS...SOUTHERN
VERMONT...BERKSHIRE COUNTY MA AND THE CATSKILLS. ALSO A FEW
ISOLATED CELLS EXPECTED OVER THE ADIRONDACKS THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
THE UPPER LEVEL DISTURBANCE WILL PASS TO OUR SOUTH AND WEST
TUESDAY NIGHT INTO WEDNESDAY. GUIDANCE KEEPS THE UPPER LEVEL
TROUGH POSITIVELY TILTED AND PROGRESSIVE. A COLD FRONT WILL ALSO
APPROACH AND IS EXPECTED TO CROSS THE REGION WEDNESDAY AFTERNOON
AND NIGHT. THIS WILL RESULT IN CHANCES STORMS TUESDAY THROUGH
WEDNESDAY. NO STRONG FORCING WILL BE PRESENT SO STORMS ARE NOT
EXPECTED TO BE STRONG OR SEVERE. THE STORM PREDICTION CENTER ONLY
HAS THE LOCAL AREA UNDER A GENERAL THUNDERSTORMS OUTLOOK.
GUIDANCE DOES INDICATE PWATS VALUES WILL RISE TO 1.5+ INCHES
TUESDAY NIGHT INTO WEDNESDAY AHEAD OF THE COLD FRONT...SO STORMS
WILL BE CAPABLE OF PRODUCING HEAVY DOWNPOURS WHICH COULD CAUSE
SOME URBAN AND POOR DRAINAGE FLOODING. WILL CONTINUE TO H8IGHLIGHT
THIS IN OUR HAZARDOUS WEATHER OUTLOOK.
SEASONABLY WARM TEMPERATURES ARE EXPECTED BOTH TUESDAY AND
WEDNESDAY. TUESDAY NIGHT WILL BE A MILD AND MUGGY NIGHT. HOWEVER
WITH THE PASSAGE OF THE COLD FRONT DRIER AIR WILL BE FILTERED IN
ON A NORTHERLY FLOW FOR WEDNESDAY NIGHT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
HIGH PRESSURE WILL BE SITUATED OVER THE REGION TO START THE LONG
TERM PERIOD FOR THURSDAY INTO FRIDAY. SKIES WILL BE PARTLY TO MOSTLY
CLEAR WITH NO PRECIP EXPECTED. HIGHS LOOK TO BE IN THE LOW TO MID
80S FOR VALLEY AREAS...AND LOWS WILL BE IN THE 50S FOR THURSDAY
NIGHT...AND 60S FOR FRIDAY NIGHT.
WITH STRONG RIDGING ESTABLISHING ITSELF OVER THE CENTRAL US...THE
NORTHEAST WILL BE SITUATED WITHIN NORTHWEST FLOW ALOFT. THIS WILL
ALLOW A SERIES OF WEAK UPPER LEVEL DISTURBANCES TO MOVE TOWARDS THE
REGION FROM SOUTHERN CANADA. THE TIMING OF THESE SUBTLE FEATURES IS
STILL UNKNOWN...BUT EACH DISTURBANCE WILL ALLOW A CHANCE FOR SOME
SCATTERED SHOWERS AND THUNDERSTORMS...ESP WITHIN PEAK DAYTIME
HEATING OF AFTN INTO THE EARLY EVENING HOURS. POPS START TO RISE
FOR LATE FRIDAY NIGHT...AND WILL ALLOW FOR CHC POPS ON BOTH
SAT/SUNDAY. IT LOOKS LIKE THESE CONDITIONS WILL CONTINUE INTO
EARLY NEXT WEEK AS WELL. IT WON/T BE A WASHOUT BY ANY MEANS...BUT
CAN/T RULE OUT THESE SHOWERS AND THUNDERSTORMS THANKS TO THE
PASSING SHORTWAVE ALOFT.
MAX TEMPS OVER THE WEEKEND WILL GENERALLY BE IN THE MID 80S...WITH
MID 60S FOR LOW TEMPS. IT WILL BE FAIRLY MUGGY AS WELL...WITH
DEWPOINTS WELL INTO THE 60S.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
SOME RADIATIONAL FOG DEVELOPED OVERNIGHT AT KGFL/KPSF...BUT THIS
WILL BE DISSIPATING QUICKLY THANKS TO THE ONSET OF DAYTIME
HEATING/MIXING. ANY LOWER VSBYS/CIGS SHOULD BE GONE WITHIN THE NEXT
HOUR OR SO...ALLOWING FOR VFR CONDITIONS TO RETURN FOR ALL SITES
FOR THE MORNING HOURS.
AN UPPER LEVEL DISTURBANCE IS APPROACHING THE REGION FROM THE
EASTERN GREAT LAKES. SCT-BKN CLOUDS ARE STREAMING AHEAD OF THIS
SYSTEM...MOSTLY HIGH CIRROSTRATUS CLOUDS AROUND 25 KFT. THROUGH THE
MORNING HOURS THERE WILL BE SOME HIGH CLOUDS AROUND...WITH A LIGHT
S-SE SFC WIND DEVELOPING AROUND 5 KTS.
SOME BREAKS IN THE HIGH CLOUDS DURING THE AFTN HOURS MAY ALLOW FOR
SOME CU TO DEVELOP AND PERHAPS EVEN A FEW SPOTTY SHOWERS...MAINLY
OVER THE HIGHER ELEVATIONS. WILL INCLUDE A VCSH FOR ALL TERMINALS TO
ACCOUNT THIS LOW PROBABILITY OF A SHOWER. CANNOT EVEN RULE OUT SOME
THUNDER...BUT CONFIDENCE IS TOO LOW TO INCLUDE AT THIS TAF ISSUANCE.
SHOWERS WILL DISSIPATE BY EVENING WITH THE LOSS OF DAYTIME HEATING.
WITH THE UPPER LEVEL DISTURBANCE NEARBY...MORE SCT-BKN HIGH CLOUDS
ARE EXPECTED FOR TONIGHT WITH NEARLY CALM SFC WINDS ONCE AGAIN. IF
ENOUGH BREAKS IN THE HIGH CLOUDS OCCUR...SOME RADIATIONAL FOG WILL
BE POSSIBLE FOR KGFL/KPSF...WITH AT LEAST MVFR CIGS/VSBYS POSSIBLE.
OUTLOOK...
TUESDAY NIGHT THROUGH WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE
OF SHRA...TSRA.
WEDNESDAY NIGHT THROUGH FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT THROUGH SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF
SHRA...TSRA.
&&
.FIRE WEATHER...
HIGH PRESSURE OVER THE REGION WILL WEAKEN TODAY AS A DISTURBANCE
IN THE UPPER LEVELS OF THE ATMOSPHERE APPROACHES FROM THE GREAT
LAKES REGION. AS A RESULT WILL BE CHANCES FOR SHOWERS AND
THUNDERSTORMS THIS AFTERNOON INTO THE EARLY EVENING. WE WILL
HAVE CHANCES FOR STORMS TUESDAY THROUGH WEDNESDAY AS A COLD
FRONT ALSO APPROACHES AND CROSSES THE AREA.
&&
.HYDROLOGY...
THERE ARE CHANCES FOR SHOWERS AND THUNDERSTORMS THIS AFTERNOON
INTO EARLY EVENING AS AN UPPER LEVEL DISTURBANCE APPROACHES FROM
THE GREAT LAKES REGION TODAY. THE DISTURBANCE WILL PASS TO OUR
SOUTH AND WEST TUESDAY NIGHT INTO WEDNESDAY AND A COLD FRONT WILL
APPROACH AND CROSS THE REGION RESULTING IN CHANCES STORMS TUESDAY
THROUGH WEDNESDAY. MODELS INDICATE PWATS VALUES WILL RISE TO 1.5+
INCHES TUESDAY NIGHT INTO WEDNESDAY AHEAD OF THE COLD FRONT...SO
STORMS WILL BE CAPABLE OF PRODUCING HEAVY DOWNPOURS WHICH COULD
CAUSE SOME URBAN AND POOR DRAINAGE FLOODING.
MAINLY DRY WEATHER IS EXPECTED THURSDAY AND FRIDAY WITH OUR NEXT
CHANCES FOR STORMS COMING OVER THE WEEKEND AS A SERIES OF WEAK
UPPER LEVEL DISTURBANCES APPROACH AND CROSS THE REGION.
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...IAA
NEAR TERM...IAA/SND
SHORT TERM...IAA
LONG TERM...FRUGIS
AVIATION...SND/FRUGIS
FIRE WEATHER...IAA
HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
848 PM EDT TUE JUL 14 2015
.Near Term [Through Tonight]...
The main concern for the overnight hours is the massive MCS
located across portions of northern GA and AL moving southward.
Cloud tops with this MCS have occasionally been as colder than
-80C, which is quite impressive indeed. While the atmosphere ahead
of it is currently unstable, the current thinking is that as the
night progresses, the low levels will stabilize somewhat with the
loss of diurnal heating, and the MCS will begin to weaken. There
is a chance it could reach the far northern counties in a
weakening state. The 23z HRRR run shows the MCS reaching our
northern row of counties around the 1 am-2 am hour and then
weakening rapidly after that.
The greater concern will be on Wednesday with some of the hi-res
models showing additional potential for another MCS to organize
across the area. Overall conditions appear favorable for some
severe weather on Wednesday.
&&
.Aviation...
[Through 00Z Thursday] Showers and thunderstorms are expected once
again tomorrow afternoon particularly at VLD and TLH. Some storms
will contain strong or even severe winds. VFR conditions expected
outside of thunderstorms.
&&
.Prev Discussion [400 PM EDT]...
.Short Term [Wednesday Through Thursday Night]...
On Wednesday, the trough over the Atlantic Seaboard will begin to
move out into the Atlantic. By Thursday, the ridge to the west
will begin to move into the region. However, sfc features (weak
low pressure and cool/stationary boundaries) will still be present
to sustain the increased rain chances. Afternoon showers and
thunderstorms will be more numerous particularly along the
seabreeze. With instability already in place, a few severe
thunderstorms are likely with the main threat being damaging
winds. A cool front will likely move in bringing nocturnal
convection particularly near the coast for Wednesday night and
Thursday night. Highs will be in the low to mid 90s with heat
indices in excess of 100 degrees.
.Long Term [Friday Through Tuesday]...
An upper level ridge will be over the region throughout most of
this forecast period. However, sfc features (weak low pressure and
cool/stationary boundaries) will still be present to sustain the
increased rain chances. The best chance for rain and thunderstorms
will be in the eastern and southeastern counties of Georgia and
Florida. Nocturnal convection is likely near the coast and over
the Gulf. Expect this wet pattern to continue into next week as
weak low pressure will linger at the sfc. This pattern will bring
some relief to the heat, particularly in the southeast portion of
the region where rain and clouds will prevail. Afternoon highs
will be in the low to mid 90s.
.Marine...
Moderate southwesterly winds will increase to cautionary levels
by late Wednesday morning along with 3 to 4 foot seas. By Friday,
winds will become light to moderate again. An unsettled weather
pattern will be in place this week, bringing increased chances for
rain and thunderstorms. Some thunderstorms will likely have very
gusty winds.
.Fire Weather...
Hazardous fire weather conditions are not expected over the next
several days.
.Hydrology...
Area rivers remain below bankfull levels. Scattered showers and
storms are expected this week, but heavy rainfall should be
relatively localized. Flooding is not expected on any of the
larger area rivers.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 76 94 76 93 77 / 30 50 30 60 40
Panama City 81 90 79 90 80 / 30 30 30 50 40
Dothan 76 96 75 95 76 / 20 40 30 40 30
Albany 75 96 75 95 76 / 40 40 40 40 20
Valdosta 76 95 75 94 75 / 40 50 30 60 40
Cross City 76 90 76 90 76 / 40 40 40 60 50
Apalachicola 81 89 79 90 80 / 30 30 40 50 40
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AL...NONE.
GM...NONE.
&&
$$
NEAR TERM...DVD
SHORT TERM...MCDERMOTT
LONG TERM...MCDERMOTT
AVIATION...MCDERMOTT
MARINE...MCDERMOTT
FIRE WEATHER...DVD
HYDROLOGY...MCDERMOTT
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
345 AM EDT MON JUL 13 2015
.Near Term [Through Today]...
The synoptic pattern this morning generally consists of a large
upper ridge centered over the Southern Plains, with a shortwave
trough axis slicing through the Northeast, then continuing
southeast off the Mid-Atlantic coast. At the surface, a very weak
pressure pattern is observed where hot afternoon temperatures
generated broad troughing across the Southeast, which has been
further disturbed by clusters of convection. A 06z subjective
analysis did pick up on a weak surface trough laid out southwest
to northeast from near Ft. Benning through Augusta. Outflow from
waning convection in this area may get just enough convergence
along this trough to generate a few scattered storms through the
remainder of the night, though a continued dissipating trend is
expected.
Ridging aloft, northwest steering flow, and no local synoptic
forcing should favor the lower coverage, type 8 seabreeze regime
this afternoon. While the overall coverage will be rather low,
near to slightly above climo PoPs will sprawl west to east across
north Florida (primarily south of Interstate-10). A large area of
SBCAPE at least 4000J/kg is analyzed offshore in the northeast
Gulf this morning. As flow turns onshore early this afternoon in
the seabreeze zone, this plume of high CAPE will be advected
towards the coast, and possibly inland along the immediate coast
(especially the southeast Big Bend). The 06z RAP depicts 4500J/kg
SBCAPE along the Taylor and Dixie coastline late this afternoon.
Thus, with the typical late storm development in this regime and
little inland penetration to the seabreeze fronts, expect the
possibility for some strong to severe storms later today. The
strongest storms will likely be near the coast or just offshore.
Additionally, with plentiful instability behind the seabreeze,
expect outflow to continue to initiate storms into the early
evening.
High temperatures will be quite hot once again today, probably
only a degree or so below yesterday`s temperatures. Heat indices
will likely remain in the 103-106 range today, which do not
warrant an advisory though caution should still be exercised if
outdoors today.
.Short Term [Tonight Through Wednesday]...
The synoptic pattern east of the Rockies will not change
appreciably over the first half of the work week, with a stout
mid-upper level high remaining centered over the Arklatex. This
will set up northwesterly flow aloft from the Great Lakes to the
Southeast, and raises the possibility of some effects from
upstream convection even this far south. Essentially all the
models show some +PV anomalies propagating southeast along the
periphery of the ridge, with some passing through or very near our
forecast area. However, the timing is somewhat inconsistent, and
models tend to struggle handling convection in persistent
northwest flow regimes over the eastern US. However, these flow
patterns do usually yield at least one or two MCVs, outflow
boundaries, or shortwaves that reach our area and enhance
convective intensity, organization, and coverage. Due to timing
uncertainties, we maintained higher PoPs at night over land areas
than would be climatologically likely this time of year. It`s
worth noting that there is fairly good agreement amongst the
models in showing a stronger shortwave reaching the Carolinas and
eastern Georgia by late Wednesday. The Storm Prediction Center has
outlined a slight risk of severe storms for later Wednesday across
parts of our area, so that may be a period when our area could see
some more organized thunderstorms.
While high temperatures may return closer to seasonal normals in
the low-mid 90s, models indicate higher afternoon dewpoints -
possibly remaining in the mid 70s in some areas. This should
continue to produce widespread heat indices around 105 degrees,
with a few areas possibly approaching Heat Advisory criteria. This
will need to be monitored, although the aforementioned uncertainty
surrounding convective timing makes it difficult to identify any
specific area or day that would be more likely to see those sort
of conditions.
.Long Term [Wednesday Night Through Monday]...
The upper level ridge will remain centered over the Arklatex
region through the extended period, which should continue to place
the forecast area in N-NW flow. This traditionally favors higher
rain chances in our Florida zones, although any areas of organized
convection that initiate north of our area could also push south
and affect more of the forecast area. The forecast continues to
indicate a chance of showers and storms each day, with highs
remaining slightly above normal - in the mid 90s. Models indicate
a continuation of elevated dewpoints during the daytime hours, so
heat indices should continue to regularly be above 100 degrees.
&&
.Aviation...
[Through 06Z Tuesday] VFR conditions are expected through the TAF
period, the only exception will be in thunderstorms. Current
thinking gives ECP the best chance for storms today, though a
storm cant be ruled out at TLH and VLD late in the afternoon.
&&
.Marine...
West winds will begin to increase later on Tuesday, with SCEC
level winds possible from Tuesday Night to Thursday Night. 15-20
knot winds are above the climatological normal for this time of
year, especially lingering for such a long period of time. In
addition, expected large atmospheric instability levels over the
coastal waters will contribute to a persistent threat of severe
winds from thunderstorms over the waters. Mariners should be
prepared for stronger winds and choppier seas than are normally
expected in July, as well as the possibility of some significant
storms over the waters this week.
&&
.Fire Weather...
Hazardous fire weather conditions are not expected over the next
several days.
&&
.Hydrology...
Area rivers remain below bankfull levels. Scattered showers and
storms are expected this week, but heavy rainfall should be
relatively localized. Flooding is not expected on any of the
larger area rivers.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 98 76 94 75 94 / 30 40 60 30 50
Panama City 93 81 90 80 90 / 30 20 40 30 40
Dothan 97 76 97 77 95 / 20 30 40 30 40
Albany 98 75 97 75 94 / 20 30 40 30 40
Valdosta 100 74 94 74 95 / 40 40 60 30 50
Cross City 95 76 90 76 92 / 50 30 50 30 50
Apalachicola 92 80 90 80 91 / 40 20 40 30 40
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AL...NONE.
GM...NONE.
&&
$$
NEAR TERM...HARRIGAN
SHORT TERM...LAMERS
LONG TERM...LAMERS
AVIATION...HARRIGAN
MARINE...LAMERS
FIRE WEATHER...HARRIGAN
HYDROLOGY...LAMERS
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1036 AM EDT MON JUL 13 2015
.SYNOPSIS...
AN INLAND TROUGH OF LOW PRESSURE WILL PERSIST THROUGH TUESDAY BEFORE
A WEAK COLD FRONT MOVES INTO THE AREA ON WEDNESDAY. THE FRONT WILL
STALL OVER AREA THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
MADE A QUICK UPDATE TO ACCOUNT FOR THE SHOWERS WHICH RECENTLY
DEVELOPED ALONG THE OLD CONVERGENCE LINE. DUE TO THE THICKER CLOUD
COVER...I ALSO NUDGED DOWN THE MAX TEMPS A DEGREE OR TWO.
12Z SOUNDING FROM CHS SHOWS A MOISTENING OF THE COLUMN BETWEEN 800
AND 600 MB COMPARED TO LAST NIGHT...LIKELY DUE TO SOME MOISTURE
DEBRIS FROM UPSTREAM CONVECTION BEING ADVECTED INTO THE TRI COUNTY
AREA. THIS CAN ALSO BE SEEN ON A LOOP OF THE GOES 7.4 UM SOUNDER
IMAGERY.
THE IMAGERY LOOP ALSO SHOWS SOME DRIER AIR AT MID LEVELS DUE TO
MOVE INTO THE AREA ALONG AND SOUTHWEST OF THE SAVANNAH RIVER
VALLEY...INDICATING THOSE AREAS WILL BECOME MORE UNSTABLE BY
AFTERNOON...HENCE SEE A SLIGHTLY BETTER CHANCE OF CONVECTION
BECOMING SEVERE. THE LATEST HRRR SEEMS TO HAVE AT LEAST A HINT
THAT THIS IS GOING ON AND HITS THE CONVECTION HARDER IN THOSE
AREAS AS WELL. STILL DOES NOT LOOK LIKE ANY KIND OF ORGANIZED
SYSTEM TODAY WITH BULK SHEAR STILL QUITE WEAK...BUT THE SURFACE
CONVERGENCE FROM THE INLAND TROF...AS WELL AS THE WESTWARD MOVING
SEA BREEZE LATER IN THE DAY...WILL KICK OFF SCATTERED CONVECTION
THIS AFTERNOON. THE CONVECTION WILL THEN LIKELY FOLLOW THE
BOUNDARIES AS THEY PROPAGATE OUTWARD FROM THE INITIAL CONVECTION.
FOR TEMPERATURES...I HAVE NOT MADE MUCH CHANGE YET...BUT MID CLOUD
DECK MOVING IN FROM THE NORTHWEST COULD PUT A CAP ON THE MAX TEMPS
TODAY AND MAY REQUIRE A SLIGHT ADJUSTMENT DOWNWARD WITH THE EARLY
AFTERNOON UPDATE.
TONIGHT...THE MODELS ARE AGAIN PROVIDING US WITH MIXED SIGNALS AS TO
WHETHER OR NOT AN MCS WILL FORM EITHER UPSTREAM OR OVER THE LOCAL
AREA. THERE IS LARGE SCALE SUPPORT FOR FORCING PROVIDED BY THE
CONTINUED LEADING EDGE OF THE UPPER JET AND POSSIBLY ANOTHER
SHORT WAVE THAT ARRIVES WITHIN THE PROBLEMATIC NW FLOW ALOFT.
SINCE THE HIGH-RES MODELS AND ECMWF ARE NOT INDICATING ANY MCS
DEVELOPING...OUR FORECAST WILL BE MORE CONSERVATIVE AND SHOW ONLY
ISOLATED TO SCATTERED POPS AND NOT INDICATIVE OF ANY ORGANIZED
SYSTEM AT THIS TIME. TEMPS WILL BE SLIGHTLY ABOVE MID-JULY NORMS
WITH ENOUGH MIXING TO PERSIST THROUGH MUCH OF THE NIGHT.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
TUESDAY...A NORTHWEST FLOW WILL HELP DIG A MID LVL TROUGH OF LOW
PRESSURE OVER THE NORTHEAST AND MID ATLANTIC STATES. AT THE SFC...AN
AREA OF LOW PRESSURE WILL BEGIN TO SHIFT TOWARD THE NORTHEASTERN
STATES...HELPING ENHANCE A PIEDMONT TROUGH TO ITS SOUTH/SOUTHWEST.
STRONG SFC HEATING AS WELL AS DEEPENING MOISTURE TO THE EAST OF THE
PIEDMONT TROUGH SHOULD FAVOR SCATTERED SHOWERS AND THUNDERSTORMS
DURING AFTERNOON AND EVENING HOURS...PARTICULARLY WHEN AN H5
SHORTWAVE SHIFTS OVER THE REGION AND A SEABREEZE SHIFTS INLAND.
THERE WILL BE A RISK OF SEVERE WEATHER LATE AFTERNOON INTO EARLY
OVERNIGHT HOURS...WITH THE PRIMARY RISKS BEING DAMAGING WINDS AND
HAIL. STRONGEST ACTIVITY IS FAVORED WHERE LOW LVL WIND FIELDS BECOME
ENHANCED...MAINLY IN SOUTHEAST SOUTH CAROLINA. A FEW STORMS COULD
LINGER INTO THE OVERNIGHT PERIOD...BUT THE GENERAL CONSENSUS IS THAT
COVERAGE AND STRENGTH OF STORMS SHOULD DECREASE WITH THE LOSS OF
DAYTIME HEATING. OVERALL HIGHS WILL RANGE IN THE LOW TO MID 90S.
LOWS SHOULD BE IN THE MID/UPPER 70S.
WEDNESDAY...A LARGE SFC LOW WILL BEGIN TO SHIFT OFF THE MID ATLANTIC
COAST WITH A WEAK COLD FRONT EXTENDING TO THE SOUTH/SOUTHWEST.
ALOFT...A STRONGER H5 SHORTWAVE WILL SHIFT OVER THE SOUTHEASTERN
UNITED STATES WITHIN A NORTHWEST FLOW WHILE A 30-35 KT LOW LVL JET
EXTENDS WEST/EAST ACROSS MUCH OF THE AREA. GIVEN THE POSITION OF THE
MOST SUBSTANTIAL FORCING ASSOCIATED WITH THE H5 SHORTWAVE AND THE
LIKELIHOOD OF CONVECTION DEVELOPING SOUTH AND EAST OF THE WEAK COLD
FRONT...SHOWER AND THUNDERSTORM COVERAGE APPEAR GREATEST NEAR
COASTAL AREAS IN SOUTHEAST SOUTH CAROLINA AND IN MOST AREAS OF
SOUTHEAST GEORGIA. SOME THUNDERSTORMS COULD BE STRONG AND/OR SEVERE
DURING THE AFTERNOON/EVENING...WITH DAMAGING WINDS AND HAIL BEING
THE PRIMARY CONCERN. HIGH TEMPS WILL BE DEPENDENT ON CLOUD COVER
PRECIP COVERAGE...BUT SHOULD PEAK BETWEEN THE LOW TO MID 90S OVER
MOST AREAS.
THURSDAY...THE BULK OF H5 SHORTWAVE ACTIVITY WILL BE OFF THE MID
ATLANTIC COAST AS WELL AS THE PRIMARY AREA OF LOW PRESSURE AT THE
SFC. HOWEVER...A WEAK AREA OF LOW PRESSURE WILL REMAIN OVER MUCH OF
THE SOUTHEAST NEAR THE VICINITY OF A STALLED AND/OR DISSIPATING
FRONT. SFC HEATING AND MOISTURE LEVELS NEAR THE WEAK LOW SHOULD
SUPPORT CHANCES OF SHOWERS/THUNDERSTORMS OVER MOST AREAS.
HOWEVER...THE THREAT OF STRONGER THUNDERSTORMS WILL BE LOWER THAN
PREVIOUS DAYS. OVERALL...HIGH TEMPS SHOULD RANGE IN THE LOW TO MID
90S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
CHANCES OF SHOWERS AND THUNDERSTORMS WILL REMAIN IN THE FORECAST
EACH DAY AS A SFC TROUGH OF LOW PRESSURE REDEVELOPS INLAND LATE
WEEK. HOWEVER...COVERAGE COULD BE SLIGHTLY MORE LIMITED ON FRIDAY AS
A LARGE RIDGE OF HIGH PRESSURE NUDGES EASTWARD OVER THE AREA.
GREATER PRECIP CHANCES SHOULD RETURN OVER THE WEEKEND AS THE DEEP
LAYERED RIDGE RETROGRADES WESTWARD IN RESPONSE TO MID LVL TROUGHING
OVER THE EASTERN CONUS. MODELS HINT AT AN UPPER LVL LOW BECOMING
CENTERED OVER THE SOUTHEASTERN UNITED STATES LATE WEEKEND INTO EARLY
NEXT WEEK...PRODUCING ADDITIONAL CHANCES OF SHOWERS AND
THUNDERSTORMS EACH DAY. OVERALL...HIGH TEMPS SHOULD RANGE IN THE LOW
TO MID 90S THROUGH LATE WEEK...THEN POSSIBLY BECOME A FEW DEGREES
COOLER AS THE MID/UPPER LVL LOW BECOMES POSITIONED OVER THE AREA
EARLY NEXT WEEK.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
PREVAILING VFR THROUGH 12Z TUESDAY. OUR NEXT CHANCE OF
CONVECTION AT THE AIRFIELDS WILL ARRIVE DURING THE AFTERNOON IN
RESPONSE TO THE SEA BREEZE...VARIOUS BOUNDARIES AND SOME ENERGY
ALOFT. PROBABILITIES ARE STILL NOT SUFFICIENT ENOUGH TO SHOW WITH
THE 12Z TAFS...SINCE MODEL CONSENSUS IS POOR. THERE IS THEN THE
RISK OF A CLUSTER OF ORGANIZED CONVECTION /AN MCS/ THAT COULD
APPROACH FROM THE NORTH/NW TONIGHT. BUT AGAIN THE MODEL CONSENSUS
IS LACKING. HOWEVER...SHOULD ANY CONVECTION DIRECTLY IMPACT THE
TERMINALS...EITHER THIS AFTERNOON OR TONIGHT...THEN THEN PERIODIC
FLIGHT RESTRICTIONS WOULD OCCUR.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS SHOULD GENERALLY PREVAIL
THROUGH LATE WEEK...BUT FLIGHT RESTRICTIONS WILL BE POSSIBLE WITH
SHOWERS AND/OR THUNDERSTORMS...ESPECIALLY TUESDAY AFTERNOON THROUGH
WEDNESDAY EVENING.
&&
.MARINE...
TODAY...CURRENT MARINE OBSERVATIONS SHOW FORECAST IS ON TRACK. A
RECOGNIZABLE SYNOPTIC PATTERN WILL AGAIN PREVAIL...SIMILAR TO WHAT
WE HAVE SEEN MUCH OF THE PAST SEVERAL WEEKS. A NE-SW ALIGNED
PIEDMONT TROUGH AND SUB- TROPICAL ATLANTIC RIDGING ACROSS FLORIDA.
THIS PROVIDES THE REGION WITH A SW FLOW THIS MORNING...BEFORE
WINDS BACK TO THE SOUTH WITH SEA BREEZE INFLUENCES THIS AFTERNOON.
WINDS WILL HOLD AT OR BELOW 10 OR 12 KT THIS MORNING...THEN RISE
UP TO 12- 16 KT THIS AFTERNOON...GREATEST IN CHARLESTON HARBOR
AND THE CHARLESTON COUNTY ATLANTIC WATERS. OF COURSE SHOULD
CONVECTIVE CLOUDINESS INCREASE IN GREATER COVERAGE...THEN THIS
FORECAST MIGHT BE A BIT ON THE HIGH SIDE. BUT BASED ON THESE WINDS
WE LOOK FOR SEA NO MORE THAN 2 OR 3 FT.
TONIGHT...OUR FORECAST IS BASED ON A SCENARIO OF INLAND TROUGH AND
RIDGING TO THE SOUTH/SE...WITH DECENT NOCTURNAL JETTING INFLUENCES TO
BOOST SOUTH/SW WINDS UP TO 15-20 KT AND GUSTY. WE MIGHT EVEN FLIRT
WITH MARGINAL SCA/S OVER OUR AMZ350 AS A RESULT. HOWEVER...SHOULD
ANY CONVECTIVE COMPLEXES DEVELOP OVER OR NEAR THE AREA THEN ALL
BETS ARE OFF...AS CONVECTION WILL STRONGLY IMPACT THESE EXPECTED
SYNOPTIC WINDS.
TUESDAY THROUGH SATURDAY...THE COASTAL WATERS WILL REMAIN SITUATED
BETWEEN HIGH PRESSURE OVER THE WESTERN ATLANTIC AND A TROUGH OF LOW
PRESSURE INLAND TO START OFF THE WEEK. A WEAK COLD FRONT COULD SHIFT
OVER THE WATERS WEDNESDAY...WITH SOME STRONGER THUNDERSTORMS AHEAD
OF IT STARTING TUESDAY NIGHT. MARGINAL SMALL CRAFT ADVISORY LEVEL
CONDITIONS WILL ALSO BE POSSIBLE AS THE PRESSURE GRADIENT TIGHTENS
AHEAD OF THE APPROACHING FRONT...STARTING TUESDAY AFTERNOON AND
PERSISTING INTO WEDNESDAY NIGHT. WEAK LOW PRESSURE SHOULD THEN
SETTLE OVER THE WATERS INTO LATE WEEK.
IN GENERAL...SOUTH/SOUTHWEST WINDS WILL INCREASE TO 15-20 KTS WITH
GUSTS AROUND 25 KTS TUESDAY AFTERNOON INTO WEDNESDAY NIGHT. WINDS
SHOULD THEN IMPROVE LATE WEEK AND BECOME MORE ONSHORE AS WEAK LOW
PRESSURE REMAINS CENTERED INLAND. SEAS WILL RANGE BETWEEN 2-4 FT
EARLY ON TUESDAY...THEN GRADUALLY BUILD TO 3-5 FT MID WEEK. WE COULD
SEE 6 FT SEAS IN OUTER GEORGIA WATERS MID WEEK. SEAS SHOULD THEN
SUBSIDE LATE WEEK.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...FWA
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
959 AM EDT MON JUL 13 2015
.SYNOPSIS...
AN INLAND TROUGH OF LOW PRESSURE WILL PERSIST THROUGH TUESDAY BEFORE
A WEAK COLD FRONT MOVES INTO THE AREA ON WEDNESDAY. THE FRONT WILL
STALL OVER AREA THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
12Z SOUNDING FROM CHS SHOWS A MOISTENING OF THE COLUMN BETWEEN 800
AND 600 MB COMPARED TO LAST NIGHT...LIKELY DUE TO SOME MOISTURE
DEBRIS FROM UPSTREAM CONVECTION BEING ADVECTED INTO THE TRI COUNTY
AREA. THIS CAN ALSO BE SEEN ON A LOOP OF THE GOES 7.4 UM SOUNDER
IMAGERY.
THE IMAGERY LOOP ALSO SHOWS SOME DRIER AIR AT MID LEVELS DUE TO
MOVE INTO THE AREA ALONG AND SOUTHWEST OF THE SAVANNAH RIVER
VALLEY...INDICATING THOSE AREAS WILL BECOME MORE UNSTABLE BY
AFTERNOON...HENCE SEE A SLIGHTLY BETTER CHANCE OF CONVECTION
BECOMING SEVERE. THE LATEST HRRR SEEMS TO HAVE AT LEAST A HINT
THAT THIS IS GOING ON AND HITS THE CONVECTION HARDER IN THOSE
AREAS AS WELL. STILL DOES NOT LOOK LIKE ANY KIND OF ORGANIZED
SYSTEM TODAY WITH BULK SHEAR STILL QUITE WEAK...BUT THE SURFACE
CONVERGENCE FROM THE INLAND TROF...AS WELL AS THE WESTWARD MOVING
SEA BREEZE LATER IN THE DAY...WILL KICK OFF SCATTERED CONVECTION
THIS AFTERNOON. THE CONVECTION WILL THEN LIKELY FOLLOW THE
BOUNDARIES AS THEY PROPAGATE OUTWARD FROM THE INITIAL CONVECTION.
FOR TEMPERATURES...I HAVE NOT MADE MUCH CHANGE YET...BUT MID CLOUD
DECK MOVING IN FROM THE NORTHWEST COULD PUT A CAP ON THE MAX TEMPS
TODAY AND MAY REQUIRE A SLIGHT ADJUSTMENT DOWNWARD WITH THE EARLY
AFTERNOON UPDATE.
TONIGHT...THE MODELS ARE AGAIN PROVIDING US WITH MIXED SIGNALS AS TO
WHETHER OR NOT AN MCS WILL FORM EITHER UPSTREAM OR OVER THE LOCAL
AREA. THERE IS LARGE SCALE SUPPORT FOR FORCING PROVIDED BY THE
CONTINUED LEADING EDGE OF THE UPPER JET AND POSSIBLY ANOTHER
SHORT WAVE THAT ARRIVES WITHIN THE PROBLEMATIC NW FLOW ALOFT.
SINCE THE HIGH-RES MODELS AND ECMWF ARE NOT INDICATING ANY MCS
DEVELOPING...OUR FORECAST WILL BE MORE CONSERVATIVE AND SHOW ONLY
ISOLATED TO SCATTERED POPS AND NOT INDICATIVE OF ANY ORGANIZED
SYSTEM AT THIS TIME. TEMPS WILL BE SLIGHTLY ABOVE MID-JULY NORMS
WITH ENOUGH MIXING TO PERSIST THROUGH MUCH OF THE NIGHT.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
TUESDAY...A NORTHWEST FLOW WILL HELP DIG A MID LVL TROUGH OF LOW
PRESSURE OVER THE NORTHEAST AND MID ATLANTIC STATES. AT THE SFC...AN
AREA OF LOW PRESSURE WILL BEGIN TO SHIFT TOWARD THE NORTHEASTERN
STATES...HELPING ENHANCE A PIEDMONT TROUGH TO ITS SOUTH/SOUTHWEST.
STRONG SFC HEATING AS WELL AS DEEPENING MOISTURE TO THE EAST OF THE
PIEDMONT TROUGH SHOULD FAVOR SCATTERED SHOWERS AND THUNDERSTORMS
DURING AFTERNOON AND EVENING HOURS...PARTICULARLY WHEN AN H5
SHORTWAVE SHIFTS OVER THE REGION AND A SEABREEZE SHIFTS INLAND.
THERE WILL BE A RISK OF SEVERE WEATHER LATE AFTERNOON INTO EARLY
OVERNIGHT HOURS...WITH THE PRIMARY RISKS BEING DAMAGING WINDS AND
HAIL. STRONGEST ACTIVITY IS FAVORED WHERE LOW LVL WIND FIELDS BECOME
ENHANCED...MAINLY IN SOUTHEAST SOUTH CAROLINA. A FEW STORMS COULD
LINGER INTO THE OVERNIGHT PERIOD...BUT THE GENERAL CONSENSUS IS THAT
COVERAGE AND STRENGTH OF STORMS SHOULD DECREASE WITH THE LOSS OF
DAYTIME HEATING. OVERALL HIGHS WILL RANGE IN THE LOW TO MID 90S.
LOWS SHOULD BE IN THE MID/UPPER 70S.
WEDNESDAY...A LARGE SFC LOW WILL BEGIN TO SHIFT OFF THE MID ATLANTIC
COAST WITH A WEAK COLD FRONT EXTENDING TO THE SOUTH/SOUTHWEST.
ALOFT...A STRONGER H5 SHORTWAVE WILL SHIFT OVER THE SOUTHEASTERN
UNITED STATES WITHIN A NORTHWEST FLOW WHILE A 30-35 KT LOW LVL JET
EXTENDS WEST/EAST ACROSS MUCH OF THE AREA. GIVEN THE POSITION OF THE
MOST SUBSTANTIAL FORCING ASSOCIATED WITH THE H5 SHORTWAVE AND THE
LIKELIHOOD OF CONVECTION DEVELOPING SOUTH AND EAST OF THE WEAK COLD
FRONT...SHOWER AND THUNDERSTORM COVERAGE APPEAR GREATEST NEAR
COASTAL AREAS IN SOUTHEAST SOUTH CAROLINA AND IN MOST AREAS OF
SOUTHEAST GEORGIA. SOME THUNDERSTORMS COULD BE STRONG AND/OR SEVERE
DURING THE AFTERNOON/EVENING...WITH DAMAGING WINDS AND HAIL BEING
THE PRIMARY CONCERN. HIGH TEMPS WILL BE DEPENDENT ON CLOUD COVER
PRECIP COVERAGE...BUT SHOULD PEAK BETWEEN THE LOW TO MID 90S OVER
MOST AREAS.
THURSDAY...THE BULK OF H5 SHORTWAVE ACTIVITY WILL BE OFF THE MID
ATLANTIC COAST AS WELL AS THE PRIMARY AREA OF LOW PRESSURE AT THE
SFC. HOWEVER...A WEAK AREA OF LOW PRESSURE WILL REMAIN OVER MUCH OF
THE SOUTHEAST NEAR THE VICINITY OF A STALLED AND/OR DISSIPATING
FRONT. SFC HEATING AND MOISTURE LEVELS NEAR THE WEAK LOW SHOULD
SUPPORT CHANCES OF SHOWERS/THUNDERSTORMS OVER MOST AREAS.
HOWEVER...THE THREAT OF STRONGER THUNDERSTORMS WILL BE LOWER THAN
PREVIOUS DAYS. OVERALL...HIGH TEMPS SHOULD RANGE IN THE LOW TO MID
90S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
CHANCES OF SHOWERS AND THUNDERSTORMS WILL REMAIN IN THE FORECAST
EACH DAY AS A SFC TROUGH OF LOW PRESSURE REDEVELOPS INLAND LATE
WEEK. HOWEVER...COVERAGE COULD BE SLIGHTLY MORE LIMITED ON FRIDAY AS
A LARGE RIDGE OF HIGH PRESSURE NUDGES EASTWARD OVER THE AREA.
GREATER PRECIP CHANCES SHOULD RETURN OVER THE WEEKEND AS THE DEEP
LAYERED RIDGE RETROGRADES WESTWARD IN RESPONSE TO MID LVL TROUGHING
OVER THE EASTERN CONUS. MODELS HINT AT AN UPPER LVL LOW BECOMING
CENTERED OVER THE SOUTHEASTERN UNITED STATES LATE WEEKEND INTO EARLY
NEXT WEEK...PRODUCING ADDITIONAL CHANCES OF SHOWERS AND
THUNDERSTORMS EACH DAY. OVERALL...HIGH TEMPS SHOULD RANGE IN THE LOW
TO MID 90S THROUGH LATE WEEK...THEN POSSIBLY BECOME A FEW DEGREES
COOLER AS THE MID/UPPER LVL LOW BECOMES POSITIONED OVER THE AREA
EARLY NEXT WEEK.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
PREVAILING VFR THROUGH 12Z TUESDAY. OUR NEXT CHANCE OF
CONVECTION AT THE AIRFIELDS WILL ARRIVE DURING THE AFTERNOON IN
RESPONSE TO THE SEA BREEZE...VARIOUS BOUNDARIES AND SOME ENERGY
ALOFT. PROBABILITIES ARE STILL NOT SUFFICIENT ENOUGH TO SHOW WITH
THE 12Z TAFS...SINCE MODEL CONSENSUS IS POOR. THERE IS THEN THE
RISK OF A CLUSTER OF ORGANIZED CONVECTION /AN MCS/ THAT COULD
APPROACH FROM THE NORTH/NW TONIGHT. BUT AGAIN THE MODEL CONSENSUS
IS LACKING. HOWEVER...SHOULD ANY CONVECTION DIRECTLY IMPACT THE
TERMINALS...EITHER THIS AFTERNOON OR TONIGHT...THEN THEN PERIODIC
FLIGHT RESTRICTIONS WOULD OCCUR.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS SHOULD GENERALLY PREVAIL
THROUGH LATE WEEK...BUT FLIGHT RESTRICTIONS WILL BE POSSIBLE WITH
SHOWERS AND/OR THUNDERSTORMS...ESPECIALLY TUESDAY AFTERNOON THROUGH
WEDNESDAY EVENING.
&&
.MARINE...
TODAY...CURRENT MARINE OBSERVATIONS SHOW FORECAST IS ON TRACK. A
RECOGNIZABLE SYNOPTIC PATTERN WILL AGAIN PREVAIL...SIMILAR TO WHAT
WE HAVE SEEN MUCH OF THE PAST SEVERAL WEEKS. A NE-SW ALIGNED
PIEDMONT TROUGH AND SUB- TROPICAL ATLANTIC RIDGING ACROSS FLORIDA.
THIS PROVIDES THE REGION WITH A SW FLOW THIS MORNING...BEFORE
WINDS BACK TO THE SOUTH WITH SEA BREEZE INFLUENCES THIS AFTERNOON.
WINDS WILL HOLD AT OR BELOW 10 OR 12 KT THIS MORNING...THEN RISE
UP TO 12- 16 KT THIS AFTERNOON...GREATEST IN CHARLESTON HARBOR
AND THE CHARLESTON COUNTY ATLANTIC WATERS. OF COURSE SHOULD
CONVECTIVE CLOUDINESS INCREASE IN GREATER COVERAGE...THEN THIS
FORECAST MIGHT BE A BIT ON THE HIGH SIDE. BUT BASED ON THESE WINDS
WE LOOK FOR SEA NO MORE THAN 2 OR 3 FT.
TONIGHT...OUR FORECAST IS BASED ON A SCENARIO OF INLAND TROUGH AND
RIDGING TO THE SOUTH/SE...WITH DECENT NOCTURNAL JETTING INFLUENCES TO
BOOST SOUTH/SW WINDS UP TO 15-20 KT AND GUSTY. WE MIGHT EVEN FLIRT
WITH MARGINAL SCA/S OVER OUR AMZ350 AS A RESULT. HOWEVER...SHOULD
ANY CONVECTIVE COMPLEXES DEVELOP OVER OR NEAR THE AREA THEN ALL
BETS ARE OFF...AS CONVECTION WILL STRONGLY IMPACT THESE EXPECTED
SYNOPTIC WINDS.
TUESDAY THROUGH SATURDAY...THE COASTAL WATERS WILL REMAIN SITUATED
BETWEEN HIGH PRESSURE OVER THE WESTERN ATLANTIC AND A TROUGH OF LOW
PRESSURE INLAND TO START OFF THE WEEK. A WEAK COLD FRONT COULD SHIFT
OVER THE WATERS WEDNESDAY...WITH SOME STRONGER THUNDERSTORMS AHEAD
OF IT STARTING TUESDAY NIGHT. MARGINAL SMALL CRAFT ADVISORY LEVEL
CONDITIONS WILL ALSO BE POSSIBLE AS THE PRESSURE GRADIENT TIGHTENS
AHEAD OF THE APPROACHING FRONT...STARTING TUESDAY AFTERNOON AND
PERSISTING INTO WEDNESDAY NIGHT. WEAK LOW PRESSURE SHOULD THEN
SETTLE OVER THE WATERS INTO LATE WEEK.
IN GENERAL...SOUTH/SOUTHWEST WINDS WILL INCREASE TO 15-20 KTS WITH
GUSTS AROUND 25 KTS TUESDAY AFTERNOON INTO WEDNESDAY NIGHT. WINDS
SHOULD THEN IMPROVE LATE WEEK AND BECOME MORE ONSHORE AS WEAK LOW
PRESSURE REMAINS CENTERED INLAND. SEAS WILL RANGE BETWEEN 2-4 FT
EARLY ON TUESDAY...THEN GRADUALLY BUILD TO 3-5 FT MID WEEK. WE COULD
SEE 6 FT SEAS IN OUTER GEORGIA WATERS MID WEEK. SEAS SHOULD THEN
SUBSIDE LATE WEEK.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...FWA
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
349 PM CDT MON JUL 13 2015
.MESOSCALE DISCUSSION...
252 PM CDT
MESOSCALE ENVIRONMENT CONTINUES TO BE MONITORED THIS AFTERNOON
FOR EVIDENCE OF CONVECTION INITIATION. CAP NOTED IN DVN 18Z RAOB
SUGGESTS A LITTLE LATER DEVELOPMENT...WHILE WARM FRONT APPEARS TO BE
EVOLVING FARTHER NORTHEAST INTO NORTHERN IL AND SUGGESTS MORE
THE MORE SUBSTANTIAL RISK MAY EXISTS FARTHER NORTH/EAST.
18Z SOUNDINGS FROM ILX AND DVN DEPICT A STRONG LOW-LEVEL CAP
NEAR/NORTH OF THE WARM FRONT (DVN)...AND EXTREME INSTABILITY (MUCAPE
OF 5300 J/KG AT DVN AND 6600 J/KG AT ILX). BOTH SOUNDINGS DEPICT
STRONG DEEP LAYER BULK SHEAR AROUND 50 KTS. THIS DATA CONTINUES TO
INDICATE A STRONG POTENTIAL FOR SEVERE THUNDERSTORMS...WITH EROSION
OF THE CAP AND TIME AND LOCATION OF INITIATION THE MAIN QUESTION.
FORECAST SOUNDINGS FROM RECENT RAP RUNS DO INDICATE WEAKENING OF THE
CAP THROUGH LATE AFTERNOON IN THE 22-00Z TIME FRAME. SATELLITE DATA
INDICATES ONE MID-LEVEL SHORT WAVE APPEARS TO BE MOVING EAST ACROSS
LAKE MICHIGAN/NORTHERN INDIANA AT 19Z...WITH A COUPLE OF ADDITIONAL
RIPPLES NOTED BACK TOWARD SOUTHEAST MINNESOTA. WITH SOME CONSISTENCY
CONVECTION ALLOWING MODELS...SUCH AS THE HRRR...SUGGEST THAT
CONVECTION INITIATION MAY VERY WELL OCCUR ACROSS PARTS OF SOUTHEAST
MINNESOTA/NORTHEAST IOWA/SOUTHWEST WISCONSIN...WHERE OUR
NORTHEASTWARD DEVELOPING WARM FRONT INTERSECTS A SW-NE SYNOPTIC
TROUGH ACROSS EASTERN IOWA. STORM MODE IS STILL ANTICIPATED TO BE
DISCRETE SUPERCELLS OR CLUSTERS...THOUGH THE LOW LEVEL WIND FIELD
HAS BECOME MORE HOMOGENEOUSLY SOUTHWEST WITH THE WARM FRONT/OLD
OUTFLOW LESS DISTINCT THAN EARLIER. THEREFORE THE INITIAL SEVERE
THREAT STILL LOOKS TO BE DAMAGING WINDS...VERY LARGE HAIL...AND
TORRENTIAL RAINFALL. SOMEWHAT WEAKER 0-1 KM SHEAR AND 0-1 KM SRH
APPEAR TO INDICATE A LOWER TORNADO THREAT...THOUGH WILL STILL
CERTAINLY EXIST WHERE A STORM INTERACTS WITH LOCALLY BACKED FLOW
ALONG ANY LINGERING BOUNDARIES. UPSCALE GROWTH INTO A LINEAR/BOWING
MCS IS STILL ANTICIPATED LATER THIS EVENING...PERHAPS CONGEALING
OVER OUR SOUTHEASTERN CWA BEFORE EXITING INTO INDIANA.
WITH THE WARM FRONT EVOLVING FARTHER NORTHEAST...IT DOES APPEAR THAT
THE SEVERE WEATHER THREAT REMAINS SIGNIFICANT ACROSS ABOUT ALL OF
THE WFO CHICAGO CWA...AND HAVE COLLABORATED WITH SPC WHO WILL
SHORTLY BE EXPANDING THE MODERATE RISK FARTHER NORTHEAST INCLUDING
THE CHICAGO METRO AREA.
RATZER
&&
.SHORT TERM...
332 PM CDT
LATE TONIGHT THROUGH TUESDAY...
BULK OF THUNDERSTORM ACTIVITY WILL EXIT DURING THE REMAINING
OVERNIGHT HOURS...HOWEVER...BROAD CYCLONIC FLOW USHERING IN A
STEADY STREAM OF SHORTWAVE ENERGY COULD ALLOW FOR ADDITIONAL
ISOLATED TO SCATTERED DEVELOPMENT THROUGH EARLY TUESDAY MORNING.
COVERAGE WILL LIKELY BE LOW...AND SO HAVE ONLY MAINTAINED SLIGHT
CHANCE TO LOW CHANCE POPS. FRONT WILL PUSH THROUGH THE AREA
THROUGH TUESDAY MORNING...BUT DONT THINK LOW LEVEL MOISTURE WILL
SCOUR TOO MUCH. GUIDANCE IN FAIR AGREEMENT WITH LOWER 70S
DEWPOINTS STILL LINGERING ACROSS THE CWA THROUGH TUESDAY. WITH
MODERATE INSTABILITY REMAINING PRESENT OVER THE CWA AND WITH
ADDITIONAL SURFACE FOCUS OWING TO SOUTHWARD MOVING SURFACE
TROUGH/BOUNDARY...THINK SCATTERED THUNDERSTORM DEVELOPMENT WILL
ONCE AGAIN BE POSSIBLE BY EARLY TUESDAY AFTERNOON. FLOW ALOFT
REMAINS SUFFICIENT FOR MODERATE BULK SHEAR VALUES TO BE IN
PLACE...AND WITH ALL OF THE FEATURES...DO THINK THAT THERE IS AT
LEAST A DECENT POSSIBILITY FOR ADDITIONAL STRONG STORMS DURING
THIS TIME.
RODRIGUEZ
&&
.LONG TERM...
240 PM CDT
TUESDAY NIGHT THROUGH MONDAY...
AN UPPER TROUGH AXIS WILL BE CLEARING THE AREA TUESDAY EVENING
WHILE UPPER RIDGING AMPLIFIES INTO THE NORTHERN PLAINS. SURFACE
HIGH PRESSURE WILL SPREAD SOUTHEASTWARD INTO THE GREAT LAKES. THIS
WILL BRING A COOL DOWN ALONG WITH NORTHEASTERLY LOW LEVEL FLOW. SO
WHILE INLAND AREAS WILL WARM TO THE UPPER 70S TO NEAR 80 LAKESHORE
AREAS WILL BE HELD TO THE LOWER 70S WEDNESDAY. THE SURFACE HIGH
WILL SHIFT EAST WEDNESDAY NIGHT WHILE THE UPPER RIDGE AXIS IS
SHUNTED EASTWARD OVER THE LOCAL AREA BY AN UPPER TROUGH MOVING
ACROSS THE MID/UPPER MISSISSIPPI RIVER VALLEY. THIS WILL RESULT IN
A PUSH OF WARM ADVECTION AND A STEADIER SOUTHERLY LOW LEVEL FLOW
FOR THURSDAY WHICH WILL MEAN WARMER TEMPS. THE BEST FORCING LOOKS
TO BE NORTH OF THE AREA AHEAD OF THE UPPER TROUGH BUT WAA WILL
PROBABLY BE STRONG ENOUGH TO BRING SOME SHOWER AND THUNDERSTORM
ACTIVITY FROM WEST TO EAST ACROSS THE AREA THURSDAY. THE UPPER
FLOW WILL BE DE-AMPLIFYING AS IT PASSES BUT SEVERAL SHORTWAVES
LOOK TO MOVE THROUGH THE FLOW AND A SURFACE LOW IS EXPECTED TO
MOVE NEAR/NORTH OF THE AREA THURSDAY NIGHT. THIS WILL KEEP DECENT
CHANCES FOR SHOWERS AND STORMS IN THE FORECAST. THE LOW WEAKENS AS
IT MOVES NORTHEAST AND ITS ATTENDANT FRONT WASHES OUT TO SOME
EXTENT SO WARMTH WILL CONTINUE TO BUILD ON SOUTHWEST WINDS. SOME
PRECIP COULD LINGER FRIDAY MORNING BUT IT DOES APPEAR DRY
CONDITIONS WILL RETURN FOR AT LEAST A SHORT TIME LATER IN THE DAY
AND FRIDAY NIGHT. ANOTHER UPPER RIDGE AMPLIFIES INTO THE AREA
SATURDAY SO WARM AND HUMID CONDITIONS WILL CONTINUE WITH A PARADE
OF SHORTWAVES BRINGING PERIODIC THUNDERSTORM CHANCES THROUGH THE
WEEKEND. SATURDAY LOOKS TO BE THE WARMEST DAY WHERE SOME AREAS
COULD REACH 90..ESPECIALLY SOUTH AND WEST...BEFORE TEMPS MODERATE
SLIGHTLY SUNDAY.
MDB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* TIMING...EXTENT...AND DURATION OF CONVECTION THIS AFTERNOON.
LENNING
//DISCUSSION...UPDATED 18Z...
THUNDERSTORMS ARE EXPECTED TO FIRE THIS AFTERNOON ACROSS
SOUTHEAST IOWA INTO CENTRAL ILLINOIS WHERE A BOUNDARY EXISTS
BETWEEN COOL OUTFLOW FROM MORNING STORMS AND THE WARM MOIST AIR
PUSHING UP FROM THE SOUTH. ADDITIONAL DEVELOPMENT EAST OF THIS
AREA WOULD THEN SPREAD INTO THE ORD/MDW TERMINALS TOWARD MID TO
LATE AFTERNOON. ISOLATED SHOWERS ARE POSSIBLE AHEAD OF THIS
ACTIVITY. THE TAF SHOWS A FOUR HOUR TEMPO WINDOW OF GREATEST
LIKELIHOOD BUT THIS ACTIVITY WOULD NOT BE EXPECTED TO PERSIST FOR
THAT LONG.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE THAT STORMS WILL DEVELOP BUT MEDIUM CONFIDENCE
ON TIMING INTO THE LOCAL TERMINALS. IN LATEST TAF AMENDMENT
PUSHED START TIME BACK AN HOUR...AND WILL CONTINUE MONITORING
NEED FOR ADDITIONAL CHANGES.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT......SLIGHT CHANCE SHRA/TSRA...OTHERWISE VFR.
WEDNESDAY AND THURSDAY...PRIMARILY VFR.
THURSDAY NIGHT AND FRIDAY...SHRA/TSRA POSSIBLE.
SATURDAY...VFR LIKELY.
SUNDAY...SHRA POSSIBLE. VFR LIKELY.
LENNING
&&
.MARINE...
349 PM CDT
SOUTHERLY WINDS OF 10 TO 20 KT CONTINUE ACROSS THE LAKE THIS
AFTERNOON...AS LOW PRESSURE REMAINS JUST TO THE WEST/NORTHWEST.
EXPECT THIS SOUTHERLY FLOW TO PERSIST FOR A PORTION OF THIS
EVENING/TONIGHT UNTIL WINDS SHIFT TO THE NORTH...AS THIS LOW AND
ASSOCIATED FRONTAL BOUNDARY MOVE THROUGH THE REGION. THESE
NORTHERLY WINDS WILL INCREASE ON TUESDAY...WITH NORTH WINDS OF 15
TO 25 KT AND THEN TO 30 KT LIKELY BY THE AFTERNOON AND EARLY
EVENING. WAVES WILL BUILD THROUGH THIS PERIOD AND THINK HAZARDOUS
CONDITIONS FOR SMALL CRAFT WILL OCCUR FOR BOTH THE ILLINOIS AND
INDIANA NEARSHORE WATERS BY EARLY TUESDAY EVENING.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 1 AM TUESDAY.
HEAT ADVISORY...ILZ010-ILZ019-ILZ021-ILZ023-ILZ032-ILZ033-ILZ039
UNTIL 7 PM MONDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 1
AM TUESDAY.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
334 PM CDT MON JUL 13 2015
.MESOSCALE DISCUSSION...
252 PM CDT
MESOSCALE ENVIRONMENT CONTINUES TO BE MONITORED THIS AFTERNOON
FOR EVIDENCE OF CONVECTION INITIATION. CAP NOTED IN DVN 18Z RAOB
SUGGESTS A LITTLE LATER DEVELOPMENT...WHILE WARM FRONT APPEARS TO BE
EVOLVING FARTHER NORTHEAST INTO NORTHERN IL AND SUGGESTS MORE
THE MORE SUBSTANTIAL RISK MAY EXISTS FARTHER NORTH/EAST.
18Z SOUNDINGS FROM ILX AND DVN DEPICT A STRONG LOW-LEVEL CAP
NEAR/NORTH OF THE WARM FRONT (DVN)...AND EXTREME INSTABILITY (MUCAPE
OF 5300 J/KG AT DVN AND 6600 J/KG AT ILX). BOTH SOUNDINGS DEPICT
STRONG DEEP LAYER BULK SHEAR AROUND 50 KTS. THIS DATA CONTINUES TO
INDICATE A STRONG POTENTIAL FOR SEVERE THUNDERSTORMS...WITH EROSION
OF THE CAP AND TIME AND LOCATION OF INITIATION THE MAIN QUESTION.
FORECAST SOUNDINGS FROM RECENT RAP RUNS DO INDICATE WEAKENING OF THE
CAP THROUGH LATE AFTERNOON IN THE 22-00Z TIME FRAME. SATELLITE DATA
INDICATES ONE MID-LEVEL SHORT WAVE APPEARS TO BE MOVING EAST ACROSS
LAKE MICHIGAN/NORTHERN INDIANA AT 19Z...WITH A COUPLE OF ADDITIONAL
RIPPLES NOTED BACK TOWARD SOUTHEAST MINNESOTA. WITH SOME CONSISTENCY
CONVECTION ALLOWING MODELS...SUCH AS THE HRRR...SUGGEST THAT
CONVECTION INITIATION MAY VERY WELL OCCUR ACROSS PARTS OF SOUTHEAST
MINNESOTA/NORTHEAST IOWA/SOUTHWEST WISCONSIN...WHERE OUR
NORTHEASTWARD DEVELOPING WARM FRONT INTERSECTS A SW-NE SYNOPTIC
TROUGH ACROSS EASTERN IOWA. STORM MODE IS STILL ANTICIPATED TO BE
DISCRETE SUPERCELLS OR CLUSTERS...THOUGH THE LOW LEVEL WIND FIELD
HAS BECOME MORE HOMOGENEOUSLY SOUTHWEST WITH THE WARM FRONT/OLD
OUTFLOW LESS DISTINCT THAN EARLIER. THEREFORE THE INITIAL SEVERE
THREAT STILL LOOKS TO BE DAMAGING WINDS...VERY LARGE HAIL...AND
TORRENTIAL RAINFALL. SOMEWHAT WEAKER 0-1 KM SHEAR AND 0-1 KM SRH
APPEAR TO INDICATE A LOWER TORNADO THREAT...THOUGH WILL STILL
CERTAINLY EXIST WHERE A STORM INTERACTS WITH LOCALLY BACKED FLOW
ALONG ANY LINGERING BOUNDARIES. UPSCALE GROWTH INTO A LINEAR/BOWING
MCS IS STILL ANTICIPATED LATER THIS EVENING...PERHAPS CONGEALING
OVER OUR SOUTHEASTERN CWA BEFORE EXITING INTO INDIANA.
WITH THE WARM FRONT EVOLVING FARTHER NORTHEAST...IT DOES APPEAR THAT
THE SEVERE WEATHER THREAT REMAINS SIGNIFICANT ACROSS ABOUT ALL OF
THE WFO CHICAGO CWA...AND HAVE COLLABORATED WITH SPC WHO WILL
SHORTLY BE EXPANDING THE MODERATE RISK FARTHER NORTHEAST INCLUDING
THE CHICAGO METRO AREA.
RATZER
&&
.SHORT TERM...
332 PM CDT
LATE TONIGHT THROUGH TUESDAY...
BULK OF THUNDERSTORM ACTIVITY WILL EXIT DURING THE REMAINING
OVERNIGHT HOURS...HOWEVER...BROAD CYCLONIC FLOW USHERING IN A
STEADY STREAM OF SHORTWAVE ENERGY COULD ALLOW FOR ADDITIONAL
ISOLATED TO SCATTERED DEVELOPMENT THROUGH EARLY TUESDAY MORNING.
COVERAGE WILL LIKELY BE LOW...AND SO HAVE ONLY MAINTAINED SLIGHT
CHANCE TO LOW CHANCE POPS. FRONT WILL PUSH THROUGH THE AREA
THROUGH TUESDAY MORNING...BUT DONT THINK LOW LEVEL MOISTURE WILL
SCOUR TOO MUCH. GUIDANCE IN FAIR AGREEMENT WITH LOWER 70S
DEWPOINTS STILL LINGERING ACROSS THE CWA THROUGH TUESDAY. WITH
MODERATE INSTABILITY REMAINING PRESENT OVER THE CWA AND WITH
ADDITIONAL SURFACE FOCUS OWING TO SOUTHWARD MOVING SURFACE
TROUGH/BOUNDARY...THINK SCATTERED THUNDERSTORM DEVELOPMENT WILL
ONCE AGAIN BE POSSIBLE BY EARLY TUESDAY AFTERNOON. FLOW ALOFT
REMAINS SUFFICIENT FOR MODERATE BULK SHEAR VALUES TO BE IN
PLACE...AND WITH ALL OF THE FEATURES...DO THINK THAT THERE IS AT
LEAST A DECENT POSSIBILITY FOR ADDITIONAL STRONG STORMS DURING
THIS TIME.
RODRIGUEZ
&&
.LONG TERM...
240 PM CDT
TUESDAY NIGHT THROUGH MONDAY...
AN UPPER TROUGH AXIS WILL BE CLEARING THE AREA TUESDAY EVENING
WHILE UPPER RIDGING AMPLIFIES INTO THE NORTHERN PLAINS. SURFACE
HIGH PRESSURE WILL SPREAD SOUTHEASTWARD INTO THE GREAT LAKES. THIS
WILL BRING A COOL DOWN ALONG WITH NORTHEASTERLY LOW LEVEL FLOW. SO
WHILE INLAND AREAS WILL WARM TO THE UPPER 70S TO NEAR 80 LAKESHORE
AREAS WILL BE HELD TO THE LOWER 70S WEDNESDAY. THE SURFACE HIGH
WILL SHIFT EAST WEDNESDAY NIGHT WHILE THE UPPER RIDGE AXIS IS
SHUNTED EASTWARD OVER THE LOCAL AREA BY AN UPPER TROUGH MOVING
ACROSS THE MID/UPPER MISSISSIPPI RIVER VALLEY. THIS WILL RESULT IN
A PUSH OF WARM ADVECTION AND A STEADIER SOUTHERLY LOW LEVEL FLOW
FOR THURSDAY WHICH WILL MEAN WARMER TEMPS. THE BEST FORCING LOOKS
TO BE NORTH OF THE AREA AHEAD OF THE UPPER TROUGH BUT WAA WILL
PROBABLY BE STRONG ENOUGH TO BRING SOME SHOWER AND THUNDERSTORM
ACTIVITY FROM WEST TO EAST ACROSS THE AREA THURSDAY. THE UPPER
FLOW WILL BE DE-AMPLIFYING AS IT PASSES BUT SEVERAL SHORTWAVES
LOOK TO MOVE THROUGH THE FLOW AND A SURFACE LOW IS EXPECTED TO
MOVE NEAR/NORTH OF THE AREA THURSDAY NIGHT. THIS WILL KEEP DECENT
CHANCES FOR SHOWERS AND STORMS IN THE FORECAST. THE LOW WEAKENS AS
IT MOVES NORTHEAST AND ITS ATTENDANT FRONT WASHES OUT TO SOME
EXTENT SO WARMTH WILL CONTINUE TO BUILD ON SOUTHWEST WINDS. SOME
PRECIP COULD LINGER FRIDAY MORNING BUT IT DOES APPEAR DRY
CONDITIONS WILL RETURN FOR AT LEAST A SHORT TIME LATER IN THE DAY
AND FRIDAY NIGHT. ANOTHER UPPER RIDGE AMPLIFIES INTO THE AREA
SATURDAY SO WARM AND HUMID CONDITIONS WILL CONTINUE WITH A PARADE
OF SHORTWAVES BRINGING PERIODIC THUNDERSTORM CHANCES THROUGH THE
WEEKEND. SATURDAY LOOKS TO BE THE WARMEST DAY WHERE SOME AREAS
COULD REACH 90..ESPECIALLY SOUTH AND WEST...BEFORE TEMPS MODERATE
SLIGHTLY SUNDAY.
MDB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* TIMING...EXTENT...AND DURATION OF CONVECTION THIS AFTERNOON.
LENNING
//DISCUSSION...UPDATED 18Z...
THUNDERSTORMS ARE EXPECTED TO FIRE THIS AFTERNOON ACROSS
SOUTHEAST IOWA INTO CENTRAL ILLINOIS WHERE A BOUNDARY EXISTS
BETWEEN COOL OUTFLOW FROM MORNING STORMS AND THE WARM MOIST AIR
PUSHING UP FROM THE SOUTH. ADDITIONAL DEVELOPMENT EAST OF THIS
AREA WOULD THEN SPREAD INTO THE ORD/MDW TERMINALS TOWARD MID TO
LATE AFTERNOON. ISOLATED SHOWERS ARE POSSIBLE AHEAD OF THIS
ACTIVITY. THE TAF SHOWS A FOUR HOUR TEMPO WINDOW OF GREATEST
LIKELIHOOD BUT THIS ACTIVITY WOULD NOT BE EXPECTED TO PERSIST FOR
THAT LONG.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE THAT STORMS WILL DEVELOP BUT MEDIUM CONFIDENCE
ON TIMING INTO THE LOCAL TERMINALS. IN LATEST TAF AMENDMENT
PUSHED START TIME BACK AN HOUR...AND WILL CONTINUE MONITORING
NEED FOR ADDITIONAL CHANGES.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT......SLIGHT CHANCE SHRA/TSRA...OTHERWISE VFR.
WEDNESDAY AND THURSDAY...PRIMARILY VFR.
THURSDAY NIGHT AND FRIDAY...SHRA/TSRA POSSIBLE.
SATURDAY...VFR LIKELY.
SUNDAY...SHRA POSSIBLE. VFR LIKELY.
LENNING
&&
.MARINE...
207 AM CDT
WITH LOW PRESSURE APPROACHING FROM THE WEST TODAY...WINDS WILL WANT
TO BE SOUTHERLY ACROSS LAKE MICHIGAN. THE EXCEPTION TO THIS WILL
BE THIS MORNING WHEN A STORM COMPLEX PASSES OVER CENTRAL AND
SOUTHERN PORTIONS OF THE LAKE. THESE STORMS WILL LIKELY
TEMPORARILY SHIFT WINDS WESTERLY AND POSSIBLY WITH BRIEF GUSTS IN
EXCESS OF 35 KNOTS. AS THE LOW PASSES OVER THE CENTRAL PART OF THE
LAKE NEAR MIDNIGHT...WINDS WILL TURN NORTH ACROSS THE NORTHERN
PART OF THE LAKE. DURING THE DAY TUESDAY THESE NORTHERLY WINDS
SHOULD ENVELOP THE LAKE WITH 20-25KT GUSTS PROBABLE. THIS WILL
LEAD TO BUILDING WAVES THROUGH TUESDAY AFTERNOON AND EVENING IN
THE ILLINOIS AND INDIANA NEARSHORES...THOUGH AT THIS TIME SMALL
CRAFT ADVISORY CRITERIA IS NOT FORECAST.
THE ONLY OTHER THING TO NOTE IS THAT THE FOG THREAT OVER THE LAKE
PER WEBCAMS AND OBSERVATIONS APPEARS TO BE LOW...WITH ANY FOG MORE
IN PATCHES AT PRESENT PER SATELLITE DERIVED PRODUCTS. THE WARMING
WATER TEMPERATURES IN JUST THE PAST WEEK AND A HALF HAVE LIKELY
HELPED TO MINIMIZE THAT CONCERN.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 1 AM TUESDAY.
HEAT ADVISORY...ILZ010-ILZ019-ILZ021-ILZ023-ILZ032-ILZ033-ILZ039
UNTIL 7 PM MONDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 1
AM TUESDAY.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
304 PM CDT MON JUL 13 2015
.MESOSCALE DISCUSSION...
252 PM CDT
MESOSCALE ENVIRONMENT CONTINUES TO BE MONITORED THIS AFTERNOON
FOR EVIDENCE OF CONVECTION INITIATION. CAP NOTED IN DVN 18Z RAOB
SUGGESTS A LITTLE LATER DEVELOPMENT...WHILE WARM FRONT APPEARS TO BE
EVOLVING FARTHER NORTHEAST INTO NORTHERN IL AND SUGGESTS MORE
THE MORE SUBSTANTIAL RISK MAY EXISTS FARTHER NORTH/EAST.
18Z SOUNDINGS FROM ILX AND DVN DEPICT A STRONG LOW-LEVEL CAP
NEAR/NORTH OF THE WARM FRONT (DVN)...AND EXTREME INSTABILITY (MUCAPE
OF 5300 J/KG AT DVN AND 6600 J/KG AT ILX). BOTH SOUNDINGS DEPICT
STRONG DEEP LAYER BULK SHEAR AROUND 50 KTS. THIS DATA CONTINUES TO
INDICATE A STRONG POTENTIAL FOR SEVERE THUNDERSTORMS...WITH EROSION
OF THE CAP AND TIME AND LOCATION OF INITIATION THE MAIN QUESTION.
FORECAST SOUNDINGS FROM RECENT RAP RUNS DO INDICATE WEAKENING OF THE
CAP THROUGH LATE AFTERNOON IN THE 22-00Z TIME FRAME. SATELLITE DATA
INDICATES ONE MID-LEVEL SHORT WAVE APPEARS TO BE MOVING EAST ACROSS
LAKE MICHIGAN/NORTHERN INDIANA AT 19Z...WITH A COUPLE OF ADDITIONAL
RIPPLES NOTED BACK TOWARD SOUTHEAST MINNESOTA. WITH SOME CONSISTENCY
CONVECTION ALLOWING MODELS...SUCH AS THE HRRR...SUGGEST THAT
CONVECTION INITIATION MAY VERY WELL OCCUR ACROSS PARTS OF SOUTHEAST
MINNESOTA/NORTHEAST IOWA/SOUTHWEST WISCONSIN...WHERE OUR
NORTHEASTWARD DEVELOPING WARM FRONT INTERSECTS A SW-NE SYNOPTIC
TROUGH ACROSS EASTERN IOWA. STORM MODE IS STILL ANTICIPATED TO BE
DISCRETE SUPERCELLS OR CLUSTERS...THOUGH THE LOW LEVEL WIND FIELD
HAS BECOME MORE HOMOGENEOUSLY SOUTHWEST WITH THE WARM FRONT/OLD
OUTFLOW LESS DISTINCT THAN EARLIER. THEREFORE THE INITIAL SEVERE
THREAT STILL LOOKS TO BE DAMAGING WINDS...VERY LARGE HAIL...AND
TORRENTIAL RAINFALL. SOMEWHAT WEAKER 0-1 KM SHEAR AND 0-1 KM SRH
APPEAR TO INDICATE A LOWER TORNADO THREAT...THOUGH WILL STILL
CERTAINLY EXIST WHERE A STORM INTERACTS WITH LOCALLY BACKED FLOW
ALONG ANY LINGERING BOUNDARIES. UPSCALE GROWTH INTO A LINEAR/BOWING
MCS IS STILL ANTICIPATED LATER THIS EVENING...PERHAPS CONGEALING
OVER OUR SOUTHEASTERN CWA BEFORE EXITING INTO INDIANA.
WITH THE WARM FRONT EVOLVING FARTHER NORTHEAST...IT DOES APPEAR THAT
THE SEVERE WEATHER THREAT REMAINS SIGNIFICANT ACROSS ABOUT ALL OF
THE WFO CHICAGO CWA...AND HAVE COLLABORATED WITH SPC WHO WILL
SHORTLY BE EXPANDING THE MODERATE RISK FARTHER NORTHEAST INCLUDING
THE CHICAGO METRO AREA.
RATZER
&&
.SHORT TERM...
400 AM CDT
THROUGH WEDNESDAY NIGHT...
SEVERE & FLASH FLOOD THREAT TODAY/TONIGHT & HEAT/HUMIDITY TODAY...
EXTREMELY COMPLEX FORECAST THE REST OF TODAY INTO TONIGHT AND ONE
THAT INCLUDES THE POTENTIAL FOR HIGHER END SEVERE WEATHER OF ALL
HAZARDS. ALSO SOME OPPRESSIVE HEAT POSSIBLY IN THE MIX. THE DEVIL
IS IN THE DETAILS...AND MESOSCALE EVOLUTION TODAY WILL IMPACT
MAGNITUDE AND LOCATION OF SEVERE THREAT...AS WELL AS TEMPS AND
HEAT INDEX VALUES ATTAINED. EVEN WITH LOWER CONFIDENCE DUE TO
UNCERTAINTY IN CONVECTIVE EVOLUTION TODAY...WILL BE ISSUING A HEAT
ADVISORY FOR THE SOUTHWEST THIRD OF THE CWA.
THE BIG QUESTION IS WHAT HAPPENS BEYOND THE ONGOING MCS TO OUR
NORTH THAT WILL LIKELY AFFECT ALL IF NOT MOST OF THE CWA THIS
MORNING AND THEN COULD SHIFT SOUTHEAST OF THE CWA BY MID DAY. FOR
ADDITIONAL DETAILS ON MCS AND ASSOCIATED SEVERE/HEAVY RAIN
POTENTIAL...REFER TO MESOSCALE DISCUSSION. FOR HI-RES CONVECTIVE
ALLOWING GUIDANCE THAT ASSISTED IN NEAR TERM PORTION OF
FORECAST...REFERRED TO MORE CONSISTENT 4KM NAM AND ARW/NMM-EAST.
HAVE DISCOUNTED HRRR/RAP AND WILD RUN TO RUN VARIATION EXHIBITED.
CONCEPTUALLY...EXPECTATION FOR MCS AND ASSOCIATED SHORTWAVE/SPEED
MAX TO PROPAGATE SOUTHEAST WOULD PUT US IN A SUBSIDENT REGIME FROM
THE MID-LATE MORNING INTO THE EARLY AFTERNOON. THERE WILL BE
DISRUPTION OF WIND FIELD AND CANNOT RULE OUT A WAKE LOW...AS WELL
AS PERIOD OF ONSHORE FLOW SLOWING TEMPERATURE RISE ALONG
LAKESHORE. IF NO BACKBUILDING OF MCS OCCURS...REMNANT OUTFLOW
BOUNDARIES ARE STILL LIKELY TO BE LEFT BEHIND. BUT TIMING OF WAVE
SHOULD ALLOW FOR CLOUD COVER TO DISSIPATE AND IMPRESSIVE EML
SAMPLED BY 00Z RAOBS TO OUR SOUTH AND WEST WILL BE ABLE TO FULLY
ADVECT EASTWARD. CLEARING/SUBSIDENCE WILL ALSO ALLOW WARM FRONT
CURRENTLY STRETCHING FROM SOUTHERN MN TO WEST CENTRAL IL TO LIFT
NORTHEAST. LAST 2 RUNS OF NAM12 HAVE REDEVELOPED CONVECTION AROUND
MID-DAY OVER CENTRAL CWA AND THEN PROPAGATED IT SOUTHEAST...WHICH
SLOWS RECOVERY PROCESS...BUT HAVE ALSO LARGELY DISCOUNTED THIS
SOLUTION.
ASSUMING WARM FRONT DOES LIFT NORTHEAST AND BRING CWA INTO WARM
SECTOR...OBS WEST OF THE BOUNDARY ON SUNDAY GENERALLY FEATURED
HIGHS IN THE UPPER 80S TO LOWER 90S AND DEWPOINTS IN THE UPPER 70S
TO AROUND 80. EXTREMELY WET SEASON SO FAR IN SOUTHERN CWA AND
EVAPOTRANSPIRATION FROM LARGE/MATURE CORN CROP LEADS ME TO BELIEVE
THAT AT LEAST A FEW SPOTS IN OUR SOUTHWEST CWA WILL REACH THESE 80
DEGREE/NEAR 80 DEWPOINTS THIS AFTERNOON. COUPLED WITH HIGHS NEAR
90...THIS WILL ENABLE HEAT INDEX VALUES TO PEAK IN 105 TO 110
RANGE...AND THUS ISSUED HEAT ADVISORY FROM LEE COUNTY TO IROQUOIS
COUNTY AND WEST. THE REST OF THE CWA SHOULD SEE PEAK HEAT INDEX
VALUES IN THE 95 TO 105 RANGE...WHICH IS STILL QUITE UNCOMFORTABLE
AND NOT SOMETHING COMMONLY EXPERIENCED THIS SUMMER SO FAR.
TEMP/DEWPOINT/CLOUD COVER FORECAST WILL THEN DICTATE WHETHER
INSTABILITY CAN BE MAXIMIZED OVER THE AREA...AND IF IT
DOES...MLCAPE VALUES OF AT LEAST 4000-5000 J/KG ARE POSSIBLE
THANKS TO HIGH DEWPOINTS AND STEEP MIDLEVEL LAPSE RATES. VOLATILE
AIRMASS WILL ALSO BE TOPPED BY NOSE OF UPPER LEVEL JET MAX OF
60-80 KT AND ABOUT 50 KT OF MIDLEVEL FLOW...PROVIDING 45-50 KT OF
NORTHWEST 0-6KM LAYER SHEAR THIS AFTERNOON INTO THIS EVENING. AT
LEAST ISOLATED TSRA CANNOT BE RULED OUT IN POSSIBLE LULL
PERIOD...BUT IF WE DO GET IT...REINITIATION OF TSRA IS EXPECTED TO
OCCUR LATE AFTERNOON INTO EARLY EVENING JUST TO WEST OR NORTHWEST
OF CWA. S0UTH-SOUTHWEST SURFACE WINDS...WESTERLY 850 MB WINDS OF
25-35 KT AND NORTHWEST MIDLEVEL WINDS WILL PROVIDE PLENTY OF
VEERING WITH HEIGHT. LOCATION OF INITIATION IS IN QUESTION...BUT
SUSPECT THAT APPROACHING COLD FRONT TRAILING FROM SURFACE LOW TO
NORTH...ASCENT FROM UPPER WAVE OVER UPPER MIDWEST AND ALSO
ELONGATED VORT MAX INTO WEST CENTRAL IL WILL BE ENOUGH TO BREAK
ANY CAPPING. ORIENTATION OF NORTHWEST SHEAR VECTOR TO INITIATING
BOUNDARY SHOULD RESULT IN AT LEAST INITIAL DISCRETE SUPERCELL
STORM MODE. THIS ALSO ADDS UNCERTAINTY TO POPS AS COVERAGE COULD
VERY WELL BE SCATTERED AND EVEN STAY SCATTERED IF EVOLUTION INTO
MCS/QLCS DOES NOT OCCUR THIS EVENING.
EXTREME INSTABILITY AND MORE THAN SUFFICIENT SHEAR...INCLUDING AT
THE LOW LEVELS...ESPECIALLY NEAR ANY LEFTOVER BOUNDARIES...MEANS
THAT EXPLOSIVE DEVELOPMENT AND ALL SEVERE HAZARDS ARE POSSIBLE.
THIS INCLUDES THE POTENTIAL FOR HIGH END DAMAGING WINDS/ESPECIALLY
IF TRANSITION TO A SEVERE MCS/QLCS OCCURS. IN ADDITION...DISCRETE
DEVELOPMENT REMAINING DOMINANT WOULD FAVOR POTENTIAL FOR
TORNADOES...INCLUDING A STRONG TORNADO OR TWO...AND LARGE TO VERY
LARGE HAIL. STORM MOTION WOULD FAVOR SOUTHEAST MOVEMENT INTO THE
MID TO LATE EVENING. IF SHORT WAVE APPROACHING FROM IA THIS
AFTERNOON ENDS UP BEING FOCUS FOR MORE WIDESPREAD
DEVELOPMENT...THIS COULD KEEP HIGHER END SEVERE THREAT OUT OF FAR
NORTHERN AND NORTHEAST IL AND EXTREME NORTHWEST INDIANA...AS PER
CURRENT DEPICTION OF MODERATE AND ENHANCED RISK FROM CWA. ANY
INTENSE CONVECTION WILL BE IN AN EXTREMELY MOIST AIRMASS...SO
EXCESSIVE RAIN RATES AND FLASH FLOODING WOULD BE LIKELY...AS IT
WONT TAKE MUCH WHETHER OVER INUNDATED SOUTHERN CWA OR URBAN AREAS.
NO CHANGES TO GOING FLASH FLOOD WATCH FOR THIS REASON. THE BOTTOM
LINE TODAY INTO TONIGHT IS STAY WEATHER AWARE...HAVE A WAY TO
RECEIVE WARNINGS...AND ALSO HAVE A SEVERE WEATHER SAFETY PLAN IN
PLACE AHEAD OF TIME SHOULD YOU NEED TO ACT. THERE ARE CERTAINLY
SCENARIOS IN WHICH CONVECTIVE EVOLUTION CAN STILL MODULATE OR EVEN
LESSEN SEVERE THREAT TODAY...BUT GIVEN PATTERN RECOGNITION OF
EXTREME CAPE AND SUFFICIENT SHEAR...SUSPECT AT LEAST PARTS OF CWA
WILL EXPERIENCE SEVERE WEATHER LATER TODAY INTO THIS EVENING AFTER
WHATEVER OCCURS THIS MORNING.
TUESDAY THROUGH WEDNESDAY NIGHT...
TUESDAY COULD FEATURE AT LEAST SCATTERED TSRA DEVELOPMENT AS
SECONDARY COLD FRONT/TROUGH AXIS INTERACTS WITH A STILL WARM AND
MOIST AIR MASS. COOLER AND DRIER AIR LOOKS TO MAKE A BRIEF RETURN
ON WEDNESDAY.
RC
&&
.LONG TERM...
240 PM CDT
TUESDAY NIGHT THROUGH MONDAY...
AN UPPER TROUGH AXIS WILL BE CLEARING THE AREA TUESDAY EVENING
WHILE UPPER RIDGING AMPLIFIES INTO THE NORTHERN PLAINS. SURFACE
HIGH PRESSURE WILL SPREAD SOUTHEASTWARD INTO THE GREAT LAKES. THIS
WILL BRING A COOL DOWN ALONG WITH NORTHEASTERLY LOW LEVEL FLOW. SO
WHILE INLAND AREAS WILL WARM TO THE UPPER 70S TO NEAR 80 LAKESHORE
AREAS WILL BE HELD TO THE LOWER 70S WEDNESDAY. THE SURFACE HIGH
WILL SHIFT EAST WEDNESDAY NIGHT WHILE THE UPPER RIDGE AXIS IS
SHUNTED EASTWARD OVER THE LOCAL AREA BY AN UPPER TROUGH MOVING
ACROSS THE MID/UPPER MISSISSIPPI RIVER VALLEY. THIS WILL RESULT IN
A PUSH OF WARM ADVECTION AND A STEADIER SOUTHERLY LOW LEVEL FLOW
FOR THURSDAY WHICH WILL MEAN WARMER TEMPS. THE BEST FORCING LOOKS
TO BE NORTH OF THE AREA AHEAD OF THE UPPER TROUGH BUT WAA WILL
PROBABLY BE STRONG ENOUGH TO BRING SOME SHOWER AND THUNDERSTORM
ACTIVITY FROM WEST TO EAST ACROSS THE AREA THURSDAY. THE UPPER
FLOW WILL BE DE-AMPLIFYING AS IT PASSES BUT SEVERAL SHORTWAVES
LOOK TO MOVE THROUGH THE FLOW AND A SURFACE LOW IS EXPECTED TO
MOVE NEAR/NORTH OF THE AREA THURSDAY NIGHT. THIS WILL KEEP DECENT
CHANCES FOR SHOWERS AND STORMS IN THE FORECAST. THE LOW WEAKENS AS
IT MOVES NORTHEAST AND ITS ATTENDANT FRONT WASHES OUT TO SOME
EXTENT SO WARMTH WILL CONTINUE TO BUILD ON SOUTHWEST WINDS. SOME
PRECIP COULD LINGER FRIDAY MORNING BUT IT DOES APPEAR DRY
CONDITIONS WILL RETURN FOR AT LEAST A SHORT TIME LATER IN THE DAY
AND FRIDAY NIGHT. ANOTHER UPPER RIDGE AMPLIFIES INTO THE AREA
SATURDAY SO WARM AND HUMID CONDITIONS WILL CONTINUE WITH A PARADE
OF SHORTWAVES BRINGING PERIODIC THUNDERSTORM CHANCES THROUGH THE
WEEKEND. SATURDAY LOOKS TO BE THE WARMEST DAY WHERE SOME AREAS
COULD REACH 90..ESPECIALLY SOUTH AND WEST...BEFORE TEMPS MODERATE
SLIGHTLY SUNDAY.
MDB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* TIMING...EXTENT...AND DURATION OF CONVECTION THIS AFTERNOON.
LENNING
//DISCUSSION...UPDATED 18Z...
THUNDERSTORMS ARE EXPECTED TO FIRE THIS AFTERNOON ACROSS
SOUTHEAST IOWA INTO CENTRAL ILLINOIS WHERE A BOUNDARY EXISTS
BETWEEN COOL OUTFLOW FROM MORNING STORMS AND THE WARM MOIST AIR
PUSHING UP FROM THE SOUTH. ADDITIONAL DEVELOPMENT EAST OF THIS
AREA WOULD THEN SPREAD INTO THE ORD/MDW TERMINALS TOWARD MID TO
LATE AFTERNOON. ISOLATED SHOWERS ARE POSSIBLE AHEAD OF THIS
ACTIVITY. THE TAF SHOWS A FOUR HOUR TEMPO WINDOW OF GREATEST
LIKELIHOOD BUT THIS ACTIVITY WOULD NOT BE EXPECTED TO PERSIST FOR
THAT LONG.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE THAT STORMS WILL DEVELOP BUT MEDIUM CONFIDENCE
ON TIMING INTO THE LOCAL TERMINALS. IN LATEST TAF AMENDMENT
PUSHED START TIME BACK AN HOUR...AND WILL CONTINUE MONITORING
NEED FOR ADDITIONAL CHANGES.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT......SLIGHT CHANCE SHRA/TSRA...OTHERWISE VFR.
WEDNESDAY AND THURSDAY...PRIMARILY VFR.
THURSDAY NIGHT AND FRIDAY...SHRA/TSRA POSSIBLE.
SATURDAY...VFR LIKELY.
SUNDAY...SHRA POSSIBLE. VFR LIKELY.
LENNING
&&
.MARINE...
207 AM CDT
WITH LOW PRESSURE APPROACHING FROM THE WEST TODAY...WINDS WILL WANT
TO BE SOUTHERLY ACROSS LAKE MICHIGAN. THE EXCEPTION TO THIS WILL
BE THIS MORNING WHEN A STORM COMPLEX PASSES OVER CENTRAL AND
SOUTHERN PORTIONS OF THE LAKE. THESE STORMS WILL LIKELY
TEMPORARILY SHIFT WINDS WESTERLY AND POSSIBLY WITH BRIEF GUSTS IN
EXCESS OF 35 KNOTS. AS THE LOW PASSES OVER THE CENTRAL PART OF THE
LAKE NEAR MIDNIGHT...WINDS WILL TURN NORTH ACROSS THE NORTHERN
PART OF THE LAKE. DURING THE DAY TUESDAY THESE NORTHERLY WINDS
SHOULD ENVELOP THE LAKE WITH 20-25KT GUSTS PROBABLE. THIS WILL
LEAD TO BUILDING WAVES THROUGH TUESDAY AFTERNOON AND EVENING IN
THE ILLINOIS AND INDIANA NEARSHORES...THOUGH AT THIS TIME SMALL
CRAFT ADVISORY CRITERIA IS NOT FORECAST.
THE ONLY OTHER THING TO NOTE IS THAT THE FOG THREAT OVER THE LAKE
PER WEBCAMS AND OBSERVATIONS APPEARS TO BE LOW...WITH ANY FOG MORE
IN PATCHES AT PRESENT PER SATELLITE DERIVED PRODUCTS. THE WARMING
WATER TEMPERATURES IN JUST THE PAST WEEK AND A HALF HAVE LIKELY
HELPED TO MINIMIZE THAT CONCERN.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 1 AM TUESDAY.
HEAT ADVISORY...ILZ010-ILZ019-ILZ021-ILZ023-ILZ032-ILZ033-ILZ039
UNTIL 7 PM MONDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 1
AM TUESDAY.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
252 PM CDT MON JUL 13 2015
.MESOSCALE DISCUSSION...
252 PM CDT
MESOSCALE ENVIRONMENT CONTINUES TO BE MONITORED THIS AFTERNOON
FOR EVIDENCE OF CONVECTION INITIATION. CAP NOTED IN DVN 18Z RAOB
SUGGESTS A LITTLE LATER DEVELOPMENT...WHILE WARM FRONT APPEARS TO BE
EVOLVING FARTHER NORTHEAST INTO NORTHERN IL AND SUGGESTS MORE
THE MORE SUBSTANTIAL RISK MAY EXISTS FARTHER NORTH/EAST.
18Z SOUNDINGS FROM ILX AND DVN DEPICT A STRONG LOW-LEVEL CAP
NEAR/NORTH OF THE WARM FRONT (DVN)...AND EXTREME INSTABILITY (MUCAPE
OF 5300 J/KG AT DVN AND 6600 J/KG AT ILX). BOTH SOUNDINGS DEPICT
STRONG DEEP LAYER BULK SHEAR AROUND 50 KTS. THIS DATA CONTINUES TO
INDICATE A STRONG POTENTIAL FOR SEVERE THUNDERSTORMS...WITH EROSION
OF THE CAP AND TIME AND LOCATION OF INITIATION THE MAIN QUESTION.
FORECAST SOUNDINGS FROM RECENT RAP RUNS DO INDICATE WEAKENING OF THE
CAP THROUGH LATE AFTERNOON IN THE 22-00Z TIME FRAME. SATELLITE DATA
INDICATES ONE MID-LEVEL SHORT WAVE APPEARS TO BE MOVING EAST ACROSS
LAKE MICHIGAN/NORTHERN INDIANA AT 19Z...WITH A COUPLE OF ADDITIONAL
RIPPLES NOTED BACK TOWARD SOUTHEAST MINNESOTA. WITH SOME CONSISTENCY
CONVECTION ALLOWING MODELS...SUCH AS THE HRRR...SUGGEST THAT
CONVECTION INITIATION MAY VERY WELL OCCUR ACROSS PARTS OF SOUTHEAST
MINNESOTA/NORTHEAST IOWA/SOUTHWEST WISCONSIN...WHERE OUR
NORTHEASTWARD DEVELOPING WARM FRONT INTERSECTS A SW-NE SYNOPTIC
TROUGH ACROSS EASTERN IOWA. STORM MODE IS STILL ANTICIPATED TO BE
DISCRETE SUPERCELLS OR CLUSTERS...THOUGH THE LOW LEVEL WIND FIELD
HAS BECOME MORE HOMOGENEOUSLY SOUTHWEST WITH THE WARM FRONT/OLD
OUTFLOW LESS DISTINCT THAN EARLIER. THEREFORE THE INITIAL SEVERE
THREAT STILL LOOKS TO BE DAMAGING WINDS...VERY LARGE HAIL...AND
TORRENTIAL RAINFALL. SOMEWHAT WEAKER 0-1 KM SHEAR AND 0-1 KM SRH
APPEAR TO INDICATE A LOWER TORNADO THREAT...THOUGH WILL STILL
CERTAINLY EXIST WHERE A STORM INTERACTS WITH LOCALLY BACKED FLOW
ALONG ANY LINGERING BOUNDARIES. UPSCALE GROWTH INTO A LINEAR/BOWING
MCS IS STILL ANTICIPATED LATER THIS EVENING...PERHAPS CONGEALING
OVER OUR SOUTHEASTERN CWA BEFORE EXITING INTO INDIANA.
WITH THE WARM FRONT EVOLVING FARTHER NORTHEAST...IT DOES APPEAR THAT
THE SEVERE WEATHER THREAT REMAINS SIGNIFICANT ACROSS ABOUT ALL OF
THE WFO CHICAGO CWA...AND HAVE COLLABORATED WITH SPC WHO WILL
SHORTLY BE EXPANDING THE MODERATE RISK FARTHER NORTHEAST INCLUDING
THE CHICAGO METRO AREA.
RATZER
&&
.SHORT TERM...
400 AM CDT
THROUGH WEDNESDAY NIGHT...
SEVERE & FLASH FLOOD THREAT TODAY/TONIGHT & HEAT/HUMIDITY TODAY...
EXTREMELY COMPLEX FORECAST THE REST OF TODAY INTO TONIGHT AND ONE
THAT INCLUDES THE POTENTIAL FOR HIGHER END SEVERE WEATHER OF ALL
HAZARDS. ALSO SOME OPPRESSIVE HEAT POSSIBLY IN THE MIX. THE DEVIL
IS IN THE DETAILS...AND MESOSCALE EVOLUTION TODAY WILL IMPACT
MAGNITUDE AND LOCATION OF SEVERE THREAT...AS WELL AS TEMPS AND
HEAT INDEX VALUES ATTAINED. EVEN WITH LOWER CONFIDENCE DUE TO
UNCERTAINTY IN CONVECTIVE EVOLUTION TODAY...WILL BE ISSUING A HEAT
ADVISORY FOR THE SOUTHWEST THIRD OF THE CWA.
THE BIG QUESTION IS WHAT HAPPENS BEYOND THE ONGOING MCS TO OUR
NORTH THAT WILL LIKELY AFFECT ALL IF NOT MOST OF THE CWA THIS
MORNING AND THEN COULD SHIFT SOUTHEAST OF THE CWA BY MID DAY. FOR
ADDITIONAL DETAILS ON MCS AND ASSOCIATED SEVERE/HEAVY RAIN
POTENTIAL...REFER TO MESOSCALE DISCUSSION. FOR HI-RES CONVECTIVE
ALLOWING GUIDANCE THAT ASSISTED IN NEAR TERM PORTION OF
FORECAST...REFERRED TO MORE CONSISTENT 4KM NAM AND ARW/NMM-EAST.
HAVE DISCOUNTED HRRR/RAP AND WILD RUN TO RUN VARIATION EXHIBITED.
CONCEPTUALLY...EXPECTATION FOR MCS AND ASSOCIATED SHORTWAVE/SPEED
MAX TO PROPAGATE SOUTHEAST WOULD PUT US IN A SUBSIDENT REGIME FROM
THE MID-LATE MORNING INTO THE EARLY AFTERNOON. THERE WILL BE
DISRUPTION OF WIND FIELD AND CANNOT RULE OUT A WAKE LOW...AS WELL
AS PERIOD OF ONSHORE FLOW SLOWING TEMPERATURE RISE ALONG
LAKESHORE. IF NO BACKBUILDING OF MCS OCCURS...REMNANT OUTFLOW
BOUNDARIES ARE STILL LIKELY TO BE LEFT BEHIND. BUT TIMING OF WAVE
SHOULD ALLOW FOR CLOUD COVER TO DISSIPATE AND IMPRESSIVE EML
SAMPLED BY 00Z RAOBS TO OUR SOUTH AND WEST WILL BE ABLE TO FULLY
ADVECT EASTWARD. CLEARING/SUBSIDENCE WILL ALSO ALLOW WARM FRONT
CURRENTLY STRETCHING FROM SOUTHERN MN TO WEST CENTRAL IL TO LIFT
NORTHEAST. LAST 2 RUNS OF NAM12 HAVE REDEVELOPED CONVECTION AROUND
MID-DAY OVER CENTRAL CWA AND THEN PROPAGATED IT SOUTHEAST...WHICH
SLOWS RECOVERY PROCESS...BUT HAVE ALSO LARGELY DISCOUNTED THIS
SOLUTION.
ASSUMING WARM FRONT DOES LIFT NORTHEAST AND BRING CWA INTO WARM
SECTOR...OBS WEST OF THE BOUNDARY ON SUNDAY GENERALLY FEATURED
HIGHS IN THE UPPER 80S TO LOWER 90S AND DEWPOINTS IN THE UPPER 70S
TO AROUND 80. EXTREMELY WET SEASON SO FAR IN SOUTHERN CWA AND
EVAPOTRANSPIRATION FROM LARGE/MATURE CORN CROP LEADS ME TO BELIEVE
THAT AT LEAST A FEW SPOTS IN OUR SOUTHWEST CWA WILL REACH THESE 80
DEGREE/NEAR 80 DEWPOINTS THIS AFTERNOON. COUPLED WITH HIGHS NEAR
90...THIS WILL ENABLE HEAT INDEX VALUES TO PEAK IN 105 TO 110
RANGE...AND THUS ISSUED HEAT ADVISORY FROM LEE COUNTY TO IROQUOIS
COUNTY AND WEST. THE REST OF THE CWA SHOULD SEE PEAK HEAT INDEX
VALUES IN THE 95 TO 105 RANGE...WHICH IS STILL QUITE UNCOMFORTABLE
AND NOT SOMETHING COMMONLY EXPERIENCED THIS SUMMER SO FAR.
TEMP/DEWPOINT/CLOUD COVER FORECAST WILL THEN DICTATE WHETHER
INSTABILITY CAN BE MAXIMIZED OVER THE AREA...AND IF IT
DOES...MLCAPE VALUES OF AT LEAST 4000-5000 J/KG ARE POSSIBLE
THANKS TO HIGH DEWPOINTS AND STEEP MIDLEVEL LAPSE RATES. VOLATILE
AIRMASS WILL ALSO BE TOPPED BY NOSE OF UPPER LEVEL JET MAX OF
60-80 KT AND ABOUT 50 KT OF MIDLEVEL FLOW...PROVIDING 45-50 KT OF
NORTHWEST 0-6KM LAYER SHEAR THIS AFTERNOON INTO THIS EVENING. AT
LEAST ISOLATED TSRA CANNOT BE RULED OUT IN POSSIBLE LULL
PERIOD...BUT IF WE DO GET IT...REINITIATION OF TSRA IS EXPECTED TO
OCCUR LATE AFTERNOON INTO EARLY EVENING JUST TO WEST OR NORTHWEST
OF CWA. S0UTH-SOUTHWEST SURFACE WINDS...WESTERLY 850 MB WINDS OF
25-35 KT AND NORTHWEST MIDLEVEL WINDS WILL PROVIDE PLENTY OF
VEERING WITH HEIGHT. LOCATION OF INITIATION IS IN QUESTION...BUT
SUSPECT THAT APPROACHING COLD FRONT TRAILING FROM SURFACE LOW TO
NORTH...ASCENT FROM UPPER WAVE OVER UPPER MIDWEST AND ALSO
ELONGATED VORT MAX INTO WEST CENTRAL IL WILL BE ENOUGH TO BREAK
ANY CAPPING. ORIENTATION OF NORTHWEST SHEAR VECTOR TO INITIATING
BOUNDARY SHOULD RESULT IN AT LEAST INITIAL DISCRETE SUPERCELL
STORM MODE. THIS ALSO ADDS UNCERTAINTY TO POPS AS COVERAGE COULD
VERY WELL BE SCATTERED AND EVEN STAY SCATTERED IF EVOLUTION INTO
MCS/QLCS DOES NOT OCCUR THIS EVENING.
EXTREME INSTABILITY AND MORE THAN SUFFICIENT SHEAR...INCLUDING AT
THE LOW LEVELS...ESPECIALLY NEAR ANY LEFTOVER BOUNDARIES...MEANS
THAT EXPLOSIVE DEVELOPMENT AND ALL SEVERE HAZARDS ARE POSSIBLE.
THIS INCLUDES THE POTENTIAL FOR HIGH END DAMAGING WINDS/ESPECIALLY
IF TRANSITION TO A SEVERE MCS/QLCS OCCURS. IN ADDITION...DISCRETE
DEVELOPMENT REMAINING DOMINANT WOULD FAVOR POTENTIAL FOR
TORNADOES...INCLUDING A STRONG TORNADO OR TWO...AND LARGE TO VERY
LARGE HAIL. STORM MOTION WOULD FAVOR SOUTHEAST MOVEMENT INTO THE
MID TO LATE EVENING. IF SHORT WAVE APPROACHING FROM IA THIS
AFTERNOON ENDS UP BEING FOCUS FOR MORE WIDESPREAD
DEVELOPMENT...THIS COULD KEEP HIGHER END SEVERE THREAT OUT OF FAR
NORTHERN AND NORTHEAST IL AND EXTREME NORTHWEST INDIANA...AS PER
CURRENT DEPICTION OF MODERATE AND ENHANCED RISK FROM CWA. ANY
INTENSE CONVECTION WILL BE IN AN EXTREMELY MOIST AIRMASS...SO
EXCESSIVE RAIN RATES AND FLASH FLOODING WOULD BE LIKELY...AS IT
WONT TAKE MUCH WHETHER OVER INUNDATED SOUTHERN CWA OR URBAN AREAS.
NO CHANGES TO GOING FLASH FLOOD WATCH FOR THIS REASON. THE BOTTOM
LINE TODAY INTO TONIGHT IS STAY WEATHER AWARE...HAVE A WAY TO
RECEIVE WARNINGS...AND ALSO HAVE A SEVERE WEATHER SAFETY PLAN IN
PLACE AHEAD OF TIME SHOULD YOU NEED TO ACT. THERE ARE CERTAINLY
SCENARIOS IN WHICH CONVECTIVE EVOLUTION CAN STILL MODULATE OR EVEN
LESSEN SEVERE THREAT TODAY...BUT GIVEN PATTERN RECOGNITION OF
EXTREME CAPE AND SUFFICIENT SHEAR...SUSPECT AT LEAST PARTS OF CWA
WILL EXPERIENCE SEVERE WEATHER LATER TODAY INTO THIS EVENING AFTER
WHATEVER OCCURS THIS MORNING.
TUESDAY THROUGH WEDNESDAY NIGHT...
TUESDAY COULD FEATURE AT LEAST SCATTERED TSRA DEVELOPMENT AS
SECONDARY COLD FRONT/TROUGH AXIS INTERACTS WITH A STILL WARM AND
MOIST AIR MASS. COOLER AND DRIER AIR LOOKS TO MAKE A BRIEF RETURN
ON WEDNESDAY.
RC
&&
.LONG TERM...
240 PM CDT
TUESDAY NIGHT THROUGH MONDAY...
AN UPPER TROUGH AXIS WILL BE CLEARING THE AREA TUESDAY EVENING
WHILE UPPER RIDGING AMPLIFIES INTO THE NORTHERN PLAINS. SURFACE
HIGH PRESSURE WILL SPREAD SOUTHEASTWARD INTO THE GREAT LAKES. THIS
WILL BRING A COOL DOWN ALONG WITH NORTHEASTERLY LOW LEVEL FLOW. SO
WHILE INLAND AREAS WILL WARM TO THE UPPER 70S TO NEAR 80 LAKESHORE
AREAS WILL BE HELD TO THE LOWER 70S WEDNESDAY. THE SURFACE HIGH
WILL SHIFT EAST WEDNESDAY NIGHT WHILE THE UPPER RIDGE AXIS IS
SHUNTED EASTWARD OVER THE LOCAL AREA BY AN UPPER TROUGH MOVING
ACROSS THE MID/UPPER MISSISSIPPI RIVER VALLEY. THIS WILL RESULT IN
A PUSH OF WARM ADVECTION AND A STEADIER SOUTHERLY LOW LEVEL FLOW
FOR THURSDAY WHICH WILL MEAN WARMER TEMPS. THE BEST FORCING LOOKS
TO BE NORTH OF THE AREA AHEAD OF THE UPPER TROUGH BUT WAA WILL
PROBABLY BE STRONG ENOUGH TO BRING SOME SHOWER AND THUNDERSTORM
ACTIVITY FROM WEST TO EAST ACROSS THE AREA THURSDAY. THE UPPER
FLOW WILL BE DE-AMPLIFYING AS IT PASSES BUT SEVERAL SHORTWAVES
LOOK TO MOVE THROUGH THE FLOW AND A SURFACE LOW IS EXPECTED TO
MOVE NEAR/NORTH OF THE AREA THURSDAY NIGHT. THIS WILL KEEP DECENT
CHANCES FOR SHOWERS AND STORMS IN THE FORECAST. THE LOW WEAKENS AS
IT MOVES NORTHEAST AND ITS ATTENDANT FRONT WASHES OUT TO SOME
EXTENT SO WARMTH WILL CONTINUE TO BUILD ON SOUTHWEST WINDS. SOME
PRECIP COULD LINGER FRIDAY MORNING BUT IT DOES APPEAR DRY
CONDITIONS WILL RETURN FOR AT LEAST A SHORT TIME LATER IN THE DAY
AND FRIDAY NIGHT. ANOTHER UPPER RIDGE AMPLIFIES INTO THE AREA
SATURDAY SO WARM AND HUMID CONDITIONS WILL CONTINUE WITH A PARADE
OF SHORTWAVES BRINGING PERIODIC THUNDERSTORM CHANCES THROUGH THE
WEEKEND. SATURDAY LOOKS TO BE THE WARMEST DAY WHERE SOME AREAS
COULD REACH 90..ESPECIALLY SOUTH AND WEST...BEFORE TEMPS MODERATE
SLIGHTLY SUNDAY.
MDB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* TIMING AND EXTENT OF THUNDERSTORMS THIS AFTERNOON AND EVENING.
* WIND TRENDS IN AND AROUND CONVECTION.
LENNING
//DISCUSSION...UPDATED 18Z...
THUNDERSTORMS ARE EXPECTED TO FIRE THIS AFTERNOON ACROSS
SOUTHEAST IOWA INTO CENTRAL ILLINOIS WHERE A BOUNDARY EXISTS
BETWEEN COOL OUTFLOW FROM MORNING STORMS AND THE WARM MOIST AIR
PUSHING UP FROM THE SOUTH. ADDITIONAL DEVELOPMENT EAST OF THIS
AREA WOULD THEN SPREAD INTO THE ORD/MDW TERMINALS TOWARD MID TO
LATE AFTERNOON. ISOLATED SHOWERS ARE POSSIBLE AHEAD OF THIS
ACTIVITY. THE TAF SHOWS A FOUR HOUR TEMPO WINDOW OF GREATEST
LIKELIHOOD BUT THIS ACTIVITY WOULD NOT BE EXPECTED TO PERSIST FOR
THAT LONG.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE ON TSRA TRENDS TODAY. HIGHER CONFIDENCE IN
WIND TRENDS.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT......SLIGHT CHANCE SHRA/TSRA...OTHERWISE VFR.
WEDNESDAY AND THURSDAY...PRIMARILY VFR.
THURSDAY NIGHT AND FRIDAY...SHRA/TSRA POSSIBLE.
SATURDAY...VFR LIKELY.
SUNDAY...SHRA POSSIBLE. VFR LIKELY.
LENNING
&&
.MARINE...
207 AM CDT
WITH LOW PRESSURE APPROACHING FROM THE WEST TODAY...WINDS WILL WANT
TO BE SOUTHERLY ACROSS LAKE MICHIGAN. THE EXCEPTION TO THIS WILL
BE THIS MORNING WHEN A STORM COMPLEX PASSES OVER CENTRAL AND
SOUTHERN PORTIONS OF THE LAKE. THESE STORMS WILL LIKELY
TEMPORARILY SHIFT WINDS WESTERLY AND POSSIBLY WITH BRIEF GUSTS IN
EXCESS OF 35 KNOTS. AS THE LOW PASSES OVER THE CENTRAL PART OF THE
LAKE NEAR MIDNIGHT...WINDS WILL TURN NORTH ACROSS THE NORTHERN
PART OF THE LAKE. DURING THE DAY TUESDAY THESE NORTHERLY WINDS
SHOULD ENVELOP THE LAKE WITH 20-25KT GUSTS PROBABLE. THIS WILL
LEAD TO BUILDING WAVES THROUGH TUESDAY AFTERNOON AND EVENING IN
THE ILLINOIS AND INDIANA NEARSHORES...THOUGH AT THIS TIME SMALL
CRAFT ADVISORY CRITERIA IS NOT FORECAST.
THE ONLY OTHER THING TO NOTE IS THAT THE FOG THREAT OVER THE LAKE
PER WEBCAMS AND OBSERVATIONS APPEARS TO BE LOW...WITH ANY FOG MORE
IN PATCHES AT PRESENT PER SATELLITE DERIVED PRODUCTS. THE WARMING
WATER TEMPERATURES IN JUST THE PAST WEEK AND A HALF HAVE LIKELY
HELPED TO MINIMIZE THAT CONCERN.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 1 AM TUESDAY.
HEAT ADVISORY...ILZ010-ILZ019-ILZ021-ILZ023-ILZ032-ILZ033-ILZ039
UNTIL 7 PM MONDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 1
AM TUESDAY.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
459 AM CDT MON JUL 13 2015
.MESOSCALE DISCUSSION..450 AM CDT
THE MCS OVER SOUTHERN WISCONSIN HAS SHOWN A STRENGTHENING TREND
OVER THE PAST 90 MINUTES OR SO AS IT CONTINUES TO MOVE SOUTHEAST.
IT APPEARS A SECOND MCV /AFTER THE FIRST NOW IN NORTHEAST WI/ HAS
DEVELOPED JUST NORTHWEST OF THE MILWAUKEE METRO AND IS A SIGN OF
SOME LONGEVITY OF THE CURRENT SEVERE WEATHER THREAT. THE OVERALL
COMPLEX CONTINUES TO MOVE SOUTHEAST...ALTHOUGH THE MOST INTENSE
CELLS/BOWS/INTERACTIONS HAVE MAINLY BEEN PROPAGATING EAST. THIS IS
LIKELY DUE TO THE BETTER ORIENTATION OF THE 0-1KM AND 0-3KM SHEAR
VECTORS AS INDICATED BY THE RAP MODEL. IN THESE AREAS...ISOLATED
DAMAGING WIND SPEEDS HAVE BEEN OBSERVED PER LSRS FROM WFO MKX. THE
LOW-LEVEL WIND SHEAR MAGNITUDE ON THE WFO MKX VAD PROFILE AND SPC
RAP ANALYSIS /25-30 KT IN 0-1KM DEPTH/ AS WELL AS INDICATIONS THAT
THE BOUNDARY LAYER IS MIXED AHEAD OF THE LINE...DO INDICATE THE
POSSIBILITY OF A BRIEF TORNADO AS WELL...AND HAVE SEEN TEMPORARY
RADAR SIGNATURES INDICATING ROTATION.
OVERALL EXPECT THE MCS TO PROPAGATE SOUTHEASTWARD THROUGH THE
FORECAST AREA...INCLUDING MOVING THROUGH THE CHICAGO METRO AREA
BETWEEN 6 AM AND 730 AM. WHILE THE SEVERE THREAT IS EXPECTED TO
BE ISOLATED TO SCATTERED WITHIN THE LINE...FAIRLY WIDESPREAD 40-45
MPH GUSTS ARE LIKELY ESPECIALLY NORTH OF I-80 THROUGH 6-7 A.M PER
UPSTREAM OBSERVATIONS.
MTF
&&
.SHORT TERM...
400 AM CDT
THROUGH WEDNESDAY NIGHT...
SEVERE & FLASH FLOOD THREAT TODAY/TONIGHT & HEAT/HUMIDITY TODAY...
EXTREMELY COMPLEX FORECAST THE REST OF TODAY INTO TONIGHT AND ONE
THAT INCLUDES THE POTENTIAL FOR HIGHER END SEVERE WEATHER OF ALL
HAZARDS. ALSO SOME OPPRESSIVE HEAT POSSIBLY IN THE MIX. THE DEVIL
IS IN THE DETAILS...AND MESOSCALE EVOLUTION TODAY WILL IMPACT
MAGNITUDE AND LOCATION OF SEVERE THREAT...AS WELL AS TEMPS AND
HEAT INDEX VALUES ATTAINED. EVEN WITH LOWER CONFIDENCE DUE TO
UNCERTAINTY IN CONVECTIVE EVOLUTION TODAY...WILL BE ISSUING A HEAT
ADVISORY FOR THE SOUTHWEST THIRD OF THE CWA.
THE BIG QUESTION IS WHAT HAPPENS BEYOND THE ONGOING MCS TO OUR
NORTH THAT WILL LIKELY AFFECT ALL IF NOT MOST OF THE CWA THIS
MORNING AND THEN COULD SHIFT SOUTHEAST OF THE CWA BY MID DAY. FOR
ADDITIONAL DETAILS ON MCS AND ASSOCIATED SEVERE/HEAVY RAIN
POTENTIAL...REFER TO MESOSCALE DISCUSSION. FOR HI-RES CONVECTIVE
ALLOWING GUIDANCE THAT ASSISTED IN NEAR TERM PORTION OF
FORECAST...REFERRED TO MORE CONSISTENT 4KM NAM AND ARW/NMM-EAST.
HAVE DISCOUNTED HRRR/RAP AND WILD RUN TO RUN VARIATION EXHIBITED.
CONCEPTUALLY...EXPECTATION FOR MCS AND ASSOCIATED SHORTWAVE/SPEED
MAX TO PROPAGATE SOUTHEAST WOULD PUT US IN A SUBSIDENT REGIME FROM
THE MID-LATE MORNING INTO THE EARLY AFTERNOON. THERE WILL BE
DISRUPTION OF WIND FIELD AND CANNOT RULE OUT A WAKE LOW...AS WELL
AS PERIOD OF ONSHORE FLOW SLOWING TEMPERATURE RISE ALONG
LAKESHORE. IF NO BACKBUILDING OF MCS OCCURS...REMNANT OUTFLOW
BOUNDARIES ARE STILL LIKELY TO BE LEFT BEHIND. BUT TIMING OF WAVE
SHOULD ALLOW FOR CLOUD COVER TO DISSIPATE AND IMPRESSIVE EML
SAMPLED BY 00Z RAOBS TO OUR SOUTH AND WEST WILL BE ABLE TO FULLY
ADVECT EASTWARD. CLEARING/SUBSIDENCE WILL ALSO ALLOW WARM FRONT
CURRENTLY STRETCHING FROM SOUTHERN MN TO WEST CENTRAL IL TO LIFT
NORTHEAST. LAST 2 RUNS OF NAM12 HAVE REDEVELOPED CONVECTION AROUND
MID-DAY OVER CENTRAL CWA AND THEN PROPAGATED IT SOUTHEAST...WHICH
SLOWS RECOVERY PROCESS...BUT HAVE ALSO LARGELY DISCOUNTED THIS
SOLUTION.
ASSUMING WARM FRONT DOES LIFT NORTHEAST AND BRING CWA INTO WARM
SECTOR...OBS WEST OF THE BOUNDARY ON SUNDAY GENERALLY FEATURED
HIGHS IN THE UPPER 80S TO LOWER 90S AND DEWPOINTS IN THE UPPER 70S
TO AROUND 80. EXTREMELY WET SEASON SO FAR IN SOUTHERN CWA AND
EVAPOTRANSPIRATION FROM LARGE/MATURE CORN CROP LEADS ME TO BELIEVE
THAT AT LEAST A FEW SPOTS IN OUR SOUTHWEST CWA WILL REACH THESE 80
DEGREE/NEAR 80 DEWPOINTS THIS AFTERNOON. COUPLED WITH HIGHS NEAR
90...THIS WILL ENABLE HEAT INDEX VALUES TO PEAK IN 105 TO 110
RANGE...AND THUS ISSUED HEAT ADVISORY FROM LEE COUNTY TO IROQUOIS
COUNTY AND WEST. THE REST OF THE CWA SHOULD SEE PEAK HEAT INDEX
VALUES IN THE 95 TO 105 RANGE...WHICH IS STILL QUITE UNCOMFORTABLE
AND NOT SOMETHING COMMONLY EXPERIENCED THIS SUMMER SO FAR.
TEMP/DEWPOINT/CLOUD COVER FORECAST WILL THEN DICTATE WHETHER
INSTABILITY CAN BE MAXIMIZED OVER THE AREA...AND IF IT
DOES...MLCAPE VALUES OF AT LEAST 4000-5000 J/KG ARE POSSIBLE
THANKS TO HIGH DEWPOINTS AND STEEP MIDLEVEL LAPSE RATES. VOLATILE
AIRMASS WILL ALSO BE TOPPED BY NOSE OF UPPER LEVEL JET MAX OF
60-80 KT AND ABOUT 50 KT OF MIDLEVEL FLOW...PROVIDING 45-50 KT OF
NORTHWEST 0-6KM LAYER SHEAR THIS AFTERNOON INTO THIS EVENING. AT
LEAST ISOLATED TSRA CANNOT BE RULED OUT IN POSSIBLE LULL
PERIOD...BUT IF WE DO GET IT...REINITIATION OF TSRA IS EXPECTED TO
OCCUR LATE AFTERNOON INTO EARLY EVENING JUST TO WEST OR NORTHWEST
OF CWA. S0UTH-SOUTHWEST SURFACE WINDS...WESTERLY 850 MB WINDS OF
25-35 KT AND NORTHWEST MIDLEVEL WINDS WILL PROVIDE PLENTY OF
VEERING WITH HEIGHT. LOCATION OF INITIATION IS IN QUESTION...BUT
SUSPECT THAT APPROACHING COLD FRONT TRAILING FROM SURFACE LOW TO
NORTH...ASCENT FROM UPPER WAVE OVER UPPER MIDWEST AND ALSO
ELONGATED VORT MAX INTO WEST CENTRAL IL WILL BE ENOUGH TO BREAK
ANY CAPPING. ORIENTATION OF NORTHWEST SHEAR VECTOR TO INITIATING
BOUNDARY SHOULD RESULT IN AT LEAST INITIAL DISCRETE SUPERCELL
STORM MODE. THIS ALSO ADDS UNCERTAINTY TO POPS AS COVERAGE COULD
VERY WELL BE SCATTERED AND EVEN STAY SCATTERED IF EVOLUTION INTO
MCS/QLCS DOES NOT OCCUR THIS EVENING.
EXTREME INSTABILITY AND MORE THAN SUFFICIENT SHEAR...INCLUDING AT
THE LOW LEVELS...ESPECIALLY NEAR ANY LEFTOVER BOUNDARIES...MEANS
THAT EXPLOSIVE DEVELOPMENT AND ALL SEVERE HAZARDS ARE POSSIBLE.
THIS INCLUDES THE POTENTIAL FOR HIGH END DAMAGING WINDS/ESPECIALLY
IF TRANSITION TO A SEVERE MCS/QLCS OCCURS. IN ADDITION...DISCRETE
DEVELOPMENT REMAINING DOMINANT WOULD FAVOR POTENTIAL FOR
TORNADOES...INCLUDING A STRONG TORNADO OR TWO...AND LARGE TO VERY
LARGE HAIL. STORM MOTION WOULD FAVOR SOUTHEAST MOVEMENT INTO THE
MID TO LATE EVENING. IF SHORT WAVE APPROACHING FROM IA THIS
AFTERNOON ENDS UP BEING FOCUS FOR MORE WIDESPREAD
DEVELOPMENT...THIS COULD KEEP HIGHER END SEVERE THREAT OUT OF FAR
NORTHERN AND NORTHEAST IL AND EXTREME NORTHWEST INDIANA...AS PER
CURRENT DEPICTION OF MODERATE AND ENHANCED RISK FROM CWA. ANY
INTENSE CONVECTION WILL BE IN AN EXTREMELY MOIST AIRMASS...SO
EXCESSIVE RAIN RATES AND FLASH FLOODING WOULD BE LIKELY...AS IT
WONT TAKE MUCH WHETHER OVER INUNDATED SOUTHERN CWA OR URBAN AREAS.
NO CHANGES TO GOING FLASH FLOOD WATCH FOR THIS REASON. THE BOTTOM
LINE TODAY INTO TONIGHT IS STAY WEATHER AWARE...HAVE A WAY TO
RECEIVE WARNINGS...AND ALSO HAVE A SEVERE WEATHER SAFETY PLAN IN
PLACE AHEAD OF TIME SHOULD YOU NEED TO ACT. THERE ARE CERTAINLY
SCENARIOS IN WHICH CONVECTIVE EVOLUTION CAN STILL MODULATE OR EVEN
LESSEN SEVERE THREAT TODAY...BUT GIVEN PATTERN RECOGNITION OF
EXTREME CAPE AND SUFFICIENT SHEAR...SUSPECT AT LEAST PARTS OF CWA
WILL EXPERIENCE SEVERE WEATHER LATER TODAY INTO THIS EVENING AFTER
WHATEVER OCCURS THIS MORNING.
TUESDAY THROUGH WEDNESDAY NIGHT...
TUESDAY COULD FEATURE AT LEAST SCATTERED TSRA DEVELOPMENT AS
SECONDARY COLD FRONT/TROUGH AXIS INTERACTS WITH A STILL WARM AND
MOIST AIR MASS. COOLER AND DRIER AIR LOOKS TO MAKE A BRIEF RETURN
ON WEDNESDAY.
RC
&&
.LONG TERM...
342 AM CDT
THURSDAY THROUGH SUNDAY...
THE EMPHASIS ON THE FORECAST WAS CERTAINLY ON THE SHORT TERM THIS
MORNING SO HAVE GONE HEAVILY WITH A WELL-VERIFYING WEIGHTED MODEL
BLEND FOR MOST OF LATE WEEK AND NEXT WEEKEND. WARM ADVECTION IS
EXPECTED TO RETURN ON THURSDAY WITH BUILDING HEIGHTS AS THE BELT OF
UPPER LEVEL WESTERLIES UNDULATES NORTH. WITH BUILDING THICKNESSES
AND LIKELY INCREASING TEMPERATURES AND MOISTURE LATE IN THE
WEEK...DAILY QPF AND OUTPUT CHANCES OF STORMS ARE PRESENTLY
PROVIDED BY GUIDANCE...ALTHOUGH A PERIOD OF A DAY OR TWO OF
CAPPING LOOKS POSSIBLE...MAINLY FRIDAY-SATURDAY. TEMPERATURES
POSSIBLY COULD REACH THE 90S WITH 850MB TEMPERATURES FORECAST BY
THE NAEFS TO BE IN THE TOP 15 PERCENTILE FOR JULY BY SATURDAY.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* PERIOD OF EARLY MORNING TSRA WITH IFR VISIBILITY CENTERED AROUND
DAYBREAK.
* WINDS BRIEFLY TURNING NORTHWEST AND GUSTING IN EXCESS OF 30 KT
WITH THE STORMS...WITH ISOLATED GUSTS IN EXCESS OF 45 KT
POSSIBLE.
* MVFR CIGS DEVELOPING PRIOR TO TSRA WITH A CHANCE FOR IFR DURING
AND JUST AFTER TSRA THROUGH MID-MORNING.
* 1-3 HOUR PERIOD OF SOUTHEAST WINDS POSSIBLY AROUND 10 KT LIKELY IN
THE WAKE OF MORNING STORMS.
* ANOTHER ROUND OF TSRA PROBABLE MONDAY AFTERNOON OR EVENING.
//DISCUSSION...UPDATED 06Z...
THE ORGANIZED AREA OF STORMS ACROSS WESTERN WI AND SOUTHEAST MN
AS OF 06Z WILL CONTINUE TO MOVE SOUTHEAST THROUGH DAYBREAK WITH
SCATTERED STORMS CONTINUE TO DEVELOP AHEAD OF THE AREA. THESE
STORMS ARE LIKELY TO FILL IN SOME PRIOR TO THE MAIN STORMS
ARRIVAL...THOUGH THAT FILL-IN MAY BE MORE OVER SOUTHERN WI. THE
ORGANIZED AREA OF STORMS IS LIKELY TO BRING TEMPORARY IFR
CONDITIONS WITH THE HEAVIEST RAIN...AS WELL AS A WIND SHIFT TO
NORTHWEST. IN THE WAKE OF THE STORMS...AS IS OFTEN SEEN IN THE
WAKE OF MCS MODE...THE WINDS WILL PROBABLY TURN EASTERLY OR
SOUTHEASTERLY DURING THE MID-MORNING. THIS MAY ONLY BE SHORT-
LIVED BUT COULD HAVE SPEEDS AROUND 10 KT.
THE CONTINUED MOIST AND VERY UNSTABLE ATMOSPHERE...ESPECIALLY
ALOFT...WILL PRESENT THE CHANCE OF STORMS AT ANY POINT TODAY AND
THE UPCOMING EVENING. THE TAFS CONTINUE TO REFLECT WHERE WE
BELIEVE THE MOST PROBABLE PERIOD IS FOR REDEVELOPING STORMS. THE
MORNING STORMS WILL INEVITABLY HAVE SOME EFFECT...POSSIBLY
DETERRING REFIRING OF ANY STORMS UNTIL LATE AFTERNOON OR EVEN
EVENING...OR POSSIBLY HAVING THEM RE-FIRE JUST WEST OF SOUTH OF
CHICAGOLAND AIRPORTS. SO THAT MAKES THE FORECAST CHALLENGING AND
DOES NOT ALLOW FOR ANYTHING MORE THAN A PROB30 REGARDING THE
SECOND ROUND...AT LEAST AT THIS TIME. ANY STORMS THAT DO REDEVELOP
IN THE AFTERNOON LIKELY WILL BE POTENT GIVEN A HIGH AMOUNT OF
INSTABILITY AND SUPPORTIVE SHEAR.
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* HIGH IN PERIOD OF TSRA AROUND DAYBREAK AND MEDIUM-HIGH IN WINDS
WITH STORMS. MEDIUM-HIGH IN TEMPORARY IFR CONDITIONS WITH STORMS.
* MEDIUM-HIGH IN PERIOD OF SOUTHEAST WINDS IN THE WAKE OF STORMS
BUT LOW IN SPEEDS AND SPECIFICALLY HOW LONG THE SHIFT WILL
LAST.
* LOW-MEDIUM IN CIGS AND VISBY THROUGH THE STORMS AND IN THEIR
WAKE.
* MEDIUM IN SECOND ROUND OF TSRA AT SOME POINT THIS AFTERNOON
AND/OR EVENING. LOW IN TIMING.
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...SLIGHT CHANCE SHRA/TSRA...OTHERWISE VFR.
WEDNESDAY AND THURSDAY...PRIMARILY VFR.
THURSDAY NIGHT AND FRIDAY...SHRA/TSRA POSSIBLE.
SATURDAY...VFR LIKELY.
MTF/IZZI
&&
.MARINE...
207 AM CDT
WITH LOW PRESSURE APPROACHING FROM THE WEST TODAY...WINDS WILL WANT
TO BE SOUTHERLY ACROSS LAKE MICHIGAN. THE EXCEPTION TO THIS WILL
BE THIS MORNING WHEN A STORM COMPLEX PASSES OVER CENTRAL AND
SOUTHERN PORTIONS OF THE LAKE. THESE STORMS WILL LIKELY
TEMPORARILY SHIFT WINDS WESTERLY AND POSSIBLY WITH BRIEF GUSTS IN
EXCESS OF 35 KNOTS. AS THE LOW PASSES OVER THE CENTRAL PART OF THE
LAKE NEAR MIDNIGHT...WINDS WILL TURN NORTH ACROSS THE NORTHERN
PART OF THE LAKE. DURING THE DAY TUESDAY THESE NORTHERLY WINDS
SHOULD ENVELOP THE LAKE WITH 20-25KT GUSTS PROBABLE. THIS WILL
LEAD TO BUILDING WAVES THROUGH TUESDAY AFTERNOON AND EVENING IN
THE ILLINOIS AND INDIANA NEARSHORES...THOUGH AT THIS TIME SMALL
CRAFT ADVISORY CRITERIA IS NOT FORECAST.
THE ONLY OTHER THING TO NOTE IS THAT THE FOG THREAT OVER THE LAKE
PER WEBCAMS AND OBSERVATIONS APPEARS TO BE LOW...WITH ANY FOG MORE
IN PATCHES AT PRESENT PER SATELLITE DERIVED PRODUCTS. THE WARMING
WATER TEMPERATURES IN JUST THE PAST WEEK AND A HALF HAVE LIKELY
HELPED TO MINIMIZE THAT CONCERN.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 1 AM TUESDAY.
HEAT ADVISORY...ILZ010-ILZ019-ILZ021-ILZ023-ILZ032-ILZ033-
ILZ039...NOON MONDAY TO 7 PM MONDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 1
AM TUESDAY.
LM...NONE.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
452 AM CDT MON JUL 13 2015
.MESOSCALE DISCUSSION...450 AM CDT
THE MCS OVER SOUTHERN WISCONSIN HAS SHOWN A STRENGTHENING TREND
OVER THE PAST 90 MINUTES OR SO AS IT CONTINUES TO MOVE SOUTHEAST.
IT APPEARS A SECOND MCV /AFTER THE FIRST NOW IN NORTHEAST WI/ HAS
DEVELOPED JUST NORTHWEST OF THE MILWAUKEE METRO AND IS A SIGN OF
SOME LONGEVITY OF THE CURRENT SEVERE WEATHER THREAT. THE OVERALL
COMPLEX CONTINUES TO MOVE SOUTHEAST...ALTHOUGH THE MOST INTENSE
CELLS/BOWS/INTERACTIONS HAVE MAINLY BEEN PROPAGATING EAST. THIS IS
LIKELY DUE TO THE BETTER ORIENTATION OF THE 0-1KM AND 0-3KM SHEAR
VECTORS AS INDICATED BY THE RAP MODEL. IN THESE AREAS...ISOLATED
DAMAGING WIND SPEEDS HAVE BEEN OBSERVED PER LSRS FROM WFO MKX. THE
LOW-LEVEL WIND SHEAR MAGNITUDE ON THE WFO MKX VAD PROFILE AND SPC
RAP ANALYSIS /25-30 KT IN 0-1KM DEPTH/ AS WELL AS INDICATIONS THAT
THE BOUNDARY LAYER IS MIXED AHEAD OF THE LINE...DO INDICATE THE
POSSIBILITY OF A BRIEF TORNADO AS WELL...AND HAVE SEEN TEMPORARY
RADAR SIGNATURES INDICATING ROTATION.
OVERALL EXPECT THE MCS TO PROPAGATE SOUTHEASTWARD THROUGH THE
FORECAST AREA...INCLUDING MOVING THROUGH THE CHICAGO METRO AREA
BETWEEN 6 AM AND 730 AM. WHILE THE SEVERE THREAT IS EXPECTED TO
BE ISOLATED TO SCATTERED WITHIN THE LINE...FAIRLY WIDESPREAD 40-45
MPH GUSTS ARE LIKELY ESPECIALLY NORTH OF I-80 THROUGH 6-7 A.M PER
UPSTREAM OBSERVATIONS.
MTF
&&
.SHORT TERM...
400 AM CDT
THROUGH WEDNESDAY NIGHT...
SEVERE & FLASH FLOOD THREAT TODAY/TONIGHT & HEAT/HUMIDITY TODAY...
EXTREMELY COMPLEX FORECAST THE REST OF TODAY INTO TONIGHT AND ONE
THAT INCLUDES THE POTENTIAL FOR HIGHER END SEVERE WEATHER OF ALL
HAZARDS. ALSO SOME OPPRESSIVE HEAT POSSIBLY IN THE MIX. THE DEVIL
IS IN THE DETAILS...AND MESOSCALE EVOLUTION TODAY WILL IMPACT
MAGNITUDE AND LOCATION OF SEVERE THREAT...AS WELL AS TEMPS AND
HEAT INDEX VALUES ATTAINED. EVEN WITH LOWER CONFIDENCE DUE TO
UNCERTAINTY IN CONVECTIVE EVOLUTION TODAY...WILL BE ISSUING A HEAT
ADVISORY FOR THE SOUTHWEST THIRD OF THE CWA.
THE BIG QUESTION IS WHAT HAPPENS BEYOND THE ONGOING MCS TO OUR
NORTH THAT WILL LIKELY AFFECT ALL IF NOT MOST OF THE CWA THIS
MORNING AND THEN COULD SHIFT SOUTHEAST OF THE CWA BY MID DAY. FOR
ADDITIONAL DETAILS ON MCS AND ASSOCIATED SEVERE/HEAVY RAIN
POTENTIAL...REFER TO MESOSCALE DISCUSSION. FOR HI-RES CONVECTIVE
ALLOWING GUIDANCE THAT ASSISTED IN NEAR TERM PORTION OF
FORECAST...REFERRED TO MORE CONSISTENT 4KM NAM AND ARW/NMM-EAST.
HAVE DISCOUNTED HRRR/RAP AND WILD RUN TO RUN VARIATION EXHIBITED.
CONCEPTUALLY...EXPECTATION FOR MCS AND ASSOCIATED SHORTWAVE/SPEED
MAX TO PROPAGATE SOUTHEAST WOULD PUT US IN A SUBSIDENT REGIME FROM
THE MID-LATE MORNING INTO THE EARLY AFTERNOON. THERE WILL BE
DISRUPTION OF WIND FIELD AND CANNOT RULE OUT A WAKE LOW...AS WELL
AS PERIOD OF ONSHORE FLOW SLOWING TEMPERATURE RISE ALONG
LAKESHORE. IF NO BACKBUILDING OF MCS OCCURS...REMNANT OUTFLOW
BOUNDARIES ARE STILL LIKELY TO BE LEFT BEHIND. BUT TIMING OF WAVE
SHOULD ALLOW FOR CLOUD COVER TO DISSIPATE AND IMPRESSIVE EML
SAMPLED BY 00Z RAOBS TO OUR SOUTH AND WEST WILL BE ABLE TO FULLY
ADVECT EASTWARD. CLEARING/SUBSIDENCE WILL ALSO ALLOW WARM FRONT
CURRENTLY STRETCHING FROM SOUTHERN MN TO WEST CENTRAL IL TO LIFT
NORTHEAST. LAST 2 RUNS OF NAM12 HAVE REDEVELOPED CONVECTION AROUND
MID-DAY OVER CENTRAL CWA AND THEN PROPAGATED IT SOUTHEAST...WHICH
SLOWS RECOVERY PROCESS...BUT HAVE ALSO LARGELY DISCOUNTED THIS
SOLUTION.
ASSUMING WARM FRONT DOES LIFT NORTHEAST AND BRING CWA INTO WARM
SECTOR...OBS WEST OF THE BOUNDARY ON SUNDAY GENERALLY FEATURED
HIGHS IN THE UPPER 80S TO LOWER 90S AND DEWPOINTS IN THE UPPER 70S
TO AROUND 80. EXTREMELY WET SEASON SO FAR IN SOUTHERN CWA AND
EVAPOTRANSPIRATION FROM LARGE/MATURE CORN CROP LEADS ME TO BELIEVE
THAT AT LEAST A FEW SPOTS IN OUR SOUTHWEST CWA WILL REACH THESE 80
DEGREE/NEAR 80 DEWPOINTS THIS AFTERNOON. COUPLED WITH HIGHS NEAR
90...THIS WILL ENABLE HEAT INDEX VALUES TO PEAK IN 105 TO 110
RANGE...AND THUS ISSUED HEAT ADVISORY FROM LEE COUNTY TO IROQUOIS
COUNTY AND WEST. THE REST OF THE CWA SHOULD SEE PEAK HEAT INDEX
VALUES IN THE 95 TO 105 RANGE...WHICH IS STILL QUITE UNCOMFORTABLE
AND NOT SOMETHING COMMONLY EXPERIENCED THIS SUMMER SO FAR.
TEMP/DEWPOINT/CLOUD COVER FORECAST WILL THEN DICTATE WHETHER
INSTABILITY CAN BE MAXIMIZED OVER THE AREA...AND IF IT
DOES...MLCAPE VALUES OF AT LEAST 4000-5000 J/KG ARE POSSIBLE
THANKS TO HIGH DEWPOINTS AND STEEP MIDLEVEL LAPSE RATES. VOLATILE
AIRMASS WILL ALSO BE TOPPED BY NOSE OF UPPER LEVEL JET MAX OF
60-80 KT AND ABOUT 50 KT OF MIDLEVEL FLOW...PROVIDING 45-50 KT OF
NORTHWEST 0-6KM LAYER SHEAR THIS AFTERNOON INTO THIS EVENING. AT
LEAST ISOLATED TSRA CANNOT BE RULED OUT IN POSSIBLE LULL
PERIOD...BUT IF WE DO GET IT...REINITIATION OF TSRA IS EXPECTED TO
OCCUR LATE AFTERNOON INTO EARLY EVENING JUST TO WEST OR NORTHWEST
OF CWA. SOUTHWEST SURFACE WINDS...WESTERLY 850 MB WINDS OF 25-35
KT AND NORTHWEST MIDLEVEL WINDS WILL PROVIDE PLENTY OF VEERING
WITH HEIGHT. LOCATION OF INITIATION IS IN QUESTION...BUT SUSPECT
THAT APPROACHING COLD FRONT TRAILING FROM SURFACE LOW TO
NORTH...ASCENT FROM UPPER WAVE OVER UPPER MIDWEST AND ALSO
ELONGATED VORT MAX INTO WEST CENTRAL IL WILL BE ENOUGH TO BREAK
ANY CAPPING. ORIENTATION OF NORTHWEST SHEAR VECTOR TO INITIATING
BOUNDARY SHOULD RESULT IN AT LEAST INITIAL DISCRETE SUPERCELL
STORM MODE. THIS ALSO ADDS UNCERTAINTY TO POPS AS COVERAGE COULD
VERY WELL BE SCATTERED AND EVEN STAY SCATTERED IF EVOLUTION INTO
MCS/QLCS DOES NOT OCCUR THIS EVENING.
EXTREME INSTABILITY AND MORE THAN SUFFICIENT SHEAR...INCLUDING AT
THE LOW LEVELS...ESPECIALLY NEAR ANY LEFTOVER BOUNDARIES...MEANS
THAT EXPLOSIVE DEVELOPMENT AND ALL SEVERE HAZARDS ARE POSSIBLE.
THIS INCLUDES THE POTENTIAL FOR HIGH END DAMAGING WINDS/ESPECIALLY
IF TRANSITION TO A SEVERE MCS/QLCS OCCURS. IN ADDITION...DISCRETE
DEVELOPMENT REMAINING DOMINANT WOULD FAVOR POTENTIAL FOR
TORNADOES...INCLUDING A STRONG TORNADO OR TWO...AND LARGE TO VERY
LARGE HAIL. STORM MOTION WOULD FAVOR SOUTHEAST MOVEMENT INTO THE
MID TO LATE EVENING. IF SHORT WAVE APPROACHING FROM IA THIS
AFTERNOON ENDS UP BEING FOCUS FOR MORE WIDESPREAD
DEVELOPMENT...THIS COULD KEEP HIGHER END SEVERE THREAT OUT OF FAR
NORTHERN AND NORTHEAST IL AND EXTREME NORTHWEST INDIANA...AS PER
CURRENT DEPICTION OF MODERATE AND ENHANCED RISK FROM CWA. ANY
INTENSE CONVECTION WILL BE IN AN EXTREMELY MOIST AIRMASS...SO
EXCESSIVE RAIN RATES AND FLASH FLOODING WOULD BE LIKELY...AS IT
WONT TAKE MUCH WHETHER OVER INUNDATED SOUTHERN CWA OR URBAN AREAS.
NO CHANGES TO GOING FLASH FLOOD WATCH FOR THIS REASON. THE BOTTOM
LINE TODAY INTO TONIGHT IS STAY WEATHER AWARE...HAVE A WAY TO
RECEIVE WARNINGS...AND ALSO HAVE A SEVERE WEATHER SAFETY PLAN IN
PLACE AHEAD OF TIME SHOULD YOU NEED TO ACT. THERE ARE CERTAINLY
SCENARIOS IN WHICH CONVECTIVE EVOLUTION CAN STILL MODULATE OR EVEN
LESSEN SEVERE THREAT TODAY...BUT GIVEN PATTERN RECOGNITION OF
EXTREME CAPE AND SUFFICIENT SHEAR...SUSPECT AT LEAST PARTS OF CWA
WILL EXPERIENCE SEVERE WEATHER LATER TODAY INTO THIS EVENING AFTER
WHATEVER OCCURS THIS MORNING.
TUESDAY THROUGH WEDNESDAY NIGHT...
TUESDAY COULD FEATURE AT LEAST SCATTERED TSRA DEVELOPMENT AS
SECONDARY COLD FRONT/TROUGH AXIS INTERACTS WITH A STILL WARM AND
MOIST AIR MASS. COOLER AND DRIER AIR LOOKS TO MAKE A BRIEF RETURN
ON WEDNESDAY.
RC
&&
.LONG TERM...
342 AM CDT
THURSDAY THROUGH SUNDAY...
THE EMPHASIS ON THE FORECAST WAS CERTAINLY ON THE SHORT TERM THIS
MORNING SO HAVE GONE HEAVILY WITH A WELL-VERIFYING WEIGHTED MODEL
BLEND FOR MOST OF LATE WEEK AND NEXT WEEKEND. WARM ADVECTION IS
EXPECTED TO RETURN ON THURSDAY WITH BUILDING HEIGHTS AS THE BELT OF
UPPER LEVEL WESTERLIES UNDULATES NORTH. WITH BUILDING THICKNESSES
AND LIKELY INCREASING TEMPERATURES AND MOISTURE LATE IN THE
WEEK...DAILY QPF AND OUTPUT CHANCES OF STORMS ARE PRESENTLY
PROVIDED BY GUIDANCE...ALTHOUGH A PERIOD OF A DAY OR TWO OF
CAPPING LOOKS POSSIBLE...MAINLY FRIDAY-SATURDAY. TEMPERATURES
POSSIBLY COULD REACH THE 90S WITH 850MB TEMPERATURES FORECAST BY
THE NAEFS TO BE IN THE TOP 15 PERCENTILE FOR JULY BY SATURDAY.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* PERIOD OF EARLY MORNING TSRA WITH IFR VISIBILITY CENTERED AROUND
DAYBREAK.
* WINDS BRIEFLY TURNING NORTHWEST AND GUSTING IN EXCESS OF 30 KT
WITH THE STORMS...WITH ISOLATED GUSTS IN EXCESS OF 45 KT
POSSIBLE.
* MVFR CIGS DEVELOPING PRIOR TO TSRA WITH A CHANCE FOR IFR DURING
AND JUST AFTER TSRA THROUGH MID-MORNING.
* 1-3 HOUR PERIOD OF SOUTHEAST WINDS POSSIBLY AROUND 10 KT LIKELY IN
THE WAKE OF MORNING STORMS.
* ANOTHER ROUND OF TSRA PROBABLE MONDAY AFTERNOON OR EVENING.
//DISCUSSION...UPDATED 06Z...
THE ORGANIZED AREA OF STORMS ACROSS WESTERN WI AND SOUTHEAST MN
AS OF 06Z WILL CONTINUE TO MOVE SOUTHEAST THROUGH DAYBREAK WITH
SCATTERED STORMS CONTINUE TO DEVELOP AHEAD OF THE AREA. THESE
STORMS ARE LIKELY TO FILL IN SOME PRIOR TO THE MAIN STORMS
ARRIVAL...THOUGH THAT FILL-IN MAY BE MORE OVER SOUTHERN WI. THE
ORGANIZED AREA OF STORMS IS LIKELY TO BRING TEMPORARY IFR
CONDITIONS WITH THE HEAVIEST RAIN...AS WELL AS A WIND SHIFT TO
NORTHWEST. IN THE WAKE OF THE STORMS...AS IS OFTEN SEEN IN THE
WAKE OF MCS MODE...THE WINDS WILL PROBABLY TURN EASTERLY OR
SOUTHEASTERLY DURING THE MID-MORNING. THIS MAY ONLY BE SHORT-
LIVED BUT COULD HAVE SPEEDS AROUND 10 KT.
THE CONTINUED MOIST AND VERY UNSTABLE ATMOSPHERE...ESPECIALLY
ALOFT...WILL PRESENT THE CHANCE OF STORMS AT ANY POINT TODAY AND
THE UPCOMING EVENING. THE TAFS CONTINUE TO REFLECT WHERE WE
BELIEVE THE MOST PROBABLE PERIOD IS FOR REDEVELOPING STORMS. THE
MORNING STORMS WILL INEVITABLY HAVE SOME EFFECT...POSSIBLY
DETERRING REFIRING OF ANY STORMS UNTIL LATE AFTERNOON OR EVEN
EVENING...OR POSSIBLY HAVING THEM RE-FIRE JUST WEST OF SOUTH OF
CHICAGOLAND AIRPORTS. SO THAT MAKES THE FORECAST CHALLENGING AND
DOES NOT ALLOW FOR ANYTHING MORE THAN A PROB30 REGARDING THE
SECOND ROUND...AT LEAST AT THIS TIME. ANY STORMS THAT DO REDEVELOP
IN THE AFTERNOON LIKELY WILL BE POTENT GIVEN A HIGH AMOUNT OF
INSTABILITY AND SUPPORTIVE SHEAR.
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* HIGH IN PERIOD OF TSRA AROUND DAYBREAK AND MEDIUM-HIGH IN WINDS
WITH STORMS. MEDIUM-HIGH IN TEMPORARY IFR CONDITIONS WITH STORMS.
* MEDIUM-HIGH IN PERIOD OF SOUTHEAST WINDS IN THE WAKE OF STORMS
BUT LOW IN SPEEDS AND SPECIFICALLY HOW LONG THE SHIFT WILL
LAST.
* LOW-MEDIUM IN CIGS AND VISBY THROUGH THE STORMS AND IN THEIR
WAKE.
* MEDIUM IN SECOND ROUND OF TSRA AT SOME POINT THIS AFTERNOON
AND/OR EVENING. LOW IN TIMING.
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...SLIGHT CHANCE SHRA/TSRA...OTHERWISE VFR.
WEDNESDAY AND THURSDAY...PRIMARILY VFR.
THURSDAY NIGHT AND FRIDAY...SHRA/TSRA POSSIBLE.
SATURDAY...VFR LIKELY.
MTF/IZZI
&&
.MARINE...
207 AM CDT
WITH LOW PRESSURE APPROACHING FROM THE WEST TODAY...WINDS WILL WANT
TO BE SOUTHERLY ACROSS LAKE MICHIGAN. THE EXCEPTION TO THIS WILL
BE THIS MORNING WHEN A STORM COMPLEX PASSES OVER CENTRAL AND
SOUTHERN PORTIONS OF THE LAKE. THESE STORMS WILL LIKELY
TEMPORARILY SHIFT WINDS WESTERLY AND POSSIBLY WITH BRIEF GUSTS IN
EXCESS OF 35 KNOTS. AS THE LOW PASSES OVER THE CENTRAL PART OF THE
LAKE NEAR MIDNIGHT...WINDS WILL TURN NORTH ACROSS THE NORTHERN
PART OF THE LAKE. DURING THE DAY TUESDAY THESE NORTHERLY WINDS
SHOULD ENVELOP THE LAKE WITH 20-25KT GUSTS PROBABLE. THIS WILL
LEAD TO BUILDING WAVES THROUGH TUESDAY AFTERNOON AND EVENING IN
THE ILLINOIS AND INDIANA NEARSHORES...THOUGH AT THIS TIME SMALL
CRAFT ADVISORY CRITERIA IS NOT FORECAST.
THE ONLY OTHER THING TO NOTE IS THAT THE FOG THREAT OVER THE LAKE
PER WEBCAMS AND OBSERVATIONS APPEARS TO BE LOW...WITH ANY FOG MORE
IN PATCHES AT PRESENT PER SATELLITE DERIVED PRODUCTS. THE WARMING
WATER TEMPERATURES IN JUST THE PAST WEEK AND A HALF HAVE LIKELY
HELPED TO MINIMIZE THAT CONCERN.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 1 AM TUESDAY.
HEAT ADVISORY...ILZ010-ILZ019-ILZ021-ILZ023-ILZ032-ILZ033-
ILZ039...NOON MONDAY TO 7 PM MONDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 1
AM TUESDAY.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
353 PM EDT MON JUL 13 2015
.SYNOPSIS...
ISSUED AT 349 PM EDT MON JUL 13 2015
SEVERE STORMS ARE EXPECTED TO DEVELOP EARLY THIS EVENING AND
CONTINUE THROUGH LATE TONIGHT. THE GREATEST THREAT WILL BE ALONG
AND SOUTH OF U.S. 30 IN INDIANA...BUT SEVERE WEATHER IS POSSIBLE
ACROSS THE ENTIRE FORECAST AREA. DAMAGING WINDS...LARGE
HAIL...AND HEAVY RAIN ARE ALL EXPECTED. BE PREPARED TO TAKE ACTION
IF A WARNING IS ISSUED FOR YOUR AREA.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 316 PM EDT MON JUL 13 2015
RAPID DESTABILIZATION HAS BEGUN ACROSS NORTHERN ILLINOIS AS EXPECTED
AT 18Z THIS AFTERNOON. THIS DESTABILIZATION WILL CONTINUE TO ADVECT
EASTWARD THROUGH THE AFTERNOON WITH THE WESTERN HALF OF OUR FORECAST
AREA INTO THE WARM SECTOR BY EARLY EVENING. 18Z DVN SPECIAL SOUNDING
SAMPLED NEARLY DRY ADIABATIC LAPSE RATES FROM H850 TO H500 AND
NEARLY 100 KNOTS OF FLOW ABOVE 300MB. WITH SURFACE TEMPERATURES IN
THE MID 80S AND DEWPOINTS IN THE UPPER 70S BENEATH THIS EML...EXPECT
EXTREME INSTABILITY OF 4000 TO 6000 J/KG BY 22Z. THIS INSTABILITY
COUPLED WITH DEEP LAYER SHEAR OF 55 TO 65 KNOTS WILL LEAD TO
EXPLOSIVE STORM DEVELOPMENT AND ORGANIZATION LATER THIS EVENING. HP
SUPERCELLS WILL BE THE PRIMARY STORM MODE FOR THE FIRST FEW HOURS
BEFORE STORMS CONGEAL INTO A FORWARD PROPAGATING MCS.
DURING THIS 22Z TO 02Z TIMEFRAME...SURFACE WINDS WILL REMAIN OUT OF
THE SSW WITH A STRENGTHENING WESTERLY LOW LEVEL JET. EXTREMELY LOW
LCLS COUPLED WITH THIS STRONG LOW LEVEL SHEAR WILL LEAD TO AN
ENHANCED TORNADIC RISK DURING THIS TIMEFRAME. ADDITIONALLY...A
STRONG TORNADO CANNOT BE RULED OUT...ESPECIALLY IF STRONGER 850 FLOW
(35 TO 40 KNOTS) FROM THE LATEST HRRR VERIFIES.
EACH RUN OF THE HRRR HAS ADVECTED THE WARM FRONT PROGRESSIVELY
FURTHER EAST...SO CANNOT RULE OUT A GREATER THREAT FURTHER NORTHEAST
THAN THE CURRENT AREA OF FOCUS WHICH IS ALONG AND SOUTH OF US 30 IN
INDIANA.
MOST OF THE CWA RECEIVED BETWEEN 1 AND 1.5 INCHES WITH THE ROUND OF
RAIN THIS MORNING. FLASH FLOODING APPEARS INCREASINGLY LIKELY THIS
EVENING WITH A VERY HIGH THETA E AIRMASS AND TRAINING STORMS
POSSIBLE. THEREFORE...WILL KEEP THE FLASH FLOOD WATCH IN EFFECT
THROUGH 06Z.
ONCE THESE STORMS MOVE THROUGH...ADDITIONAL STORMS ARE POSSIBLE LATE
TONIGHT AND INTO THE DAY TOMORROW AS THE FRONT DROPS SOUTH THROUGH
OUR AREA. EXPECT THE FRONT TO MOVE SOUTH OF OUR FORECAST AREA BEFORE
ENOUGH INSTABILITY DEVELOPS FOR SEVERE WEATHER WITHIN OUR CWA.
&&
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 316 PM EDT MON JUL 13 2015
ROBUST NRN STREAM DISTURBANCE OVR NRN MN WILL DIG SEWD
INTO THE ERN LAKES ON TUE. RESULTING TROUGH AMPLIFICATION ACRS THE
LAKES WILL SHUNT UNSTABLE LL THETA-E RIDGE SWWD UNDER PERSISTENT H5
RIDGE CNTRD ACRS E TX. HWVR RESPITE FM WET PATTN LIKELY FLEETING AS
SRN PLAINS RIDGE BLDS BACK NORTH AGAIN W/EWD FOLDING THETA-E RIDGE
XPCD DOWNSTREAM OF A SERIES OF AT TIMES CONVECTIVELY ENHANCED
DISTURBANCES EJECT OUT OF AMPLIFYING WRN US TROUGHING.
AS SUCH AND IN LIGHT OF GOOD INTERMODEL AGREEMENT REORDERED POPS/WX
FRI-SUN TO HIGHLIGHT BTR CHCS ACRS THE NORTH IN PROXIMITY TO IMPLIED
UPR JET STREAM ACRS LWR MI AND INVOF OSCILLATING SFC FNTL ZONE.
OTRWS VRY WARM TEMPS XPCD TO MANIFEST UNDERNEATH STEADILY NWD BLDG
UPR RIDGE AXIS AND NO DOUBT HOT...HUMID 90S LIKELY THIS WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 125 PM EDT MON JUL 13 2015
BOTH TERMINALS WILL BE ON THE NORTHEASTERN FRINGE OF THE BEST
THUNDERSTORM CHANCES THIS EVENING. THEREFORE HAVE KEPT ONLY A VCTS
MENTION AT THIS TIME. SCATTERED TO BROKEN CUMULUS FIELD EXPECTED
TO DEVELOP AHEAD OF THESE STORMS DURING THE LATE AFTERNOON/EARLY
EVENING WITH BASES BETWEEN 2KFT AND 3KFT. ANY STORMS WHICH DO
DEVELOP MAY BE SEVERE WITH STRONG WIND GUSTS. WILL AMEND TAF AS
NEEDED THIS EVENING IF EITHER TERMINAL APPEARS TO BE IMPACTED BY
STORMS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...FLASH FLOOD WATCH UNTIL 2 AM EDT /1 AM CDT/ TUESDAY FOR INZ003-
012-013-015-020-022>027-032>034.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...MCD
SHORT TERM...BENTLEY
LONG TERM...T
AVIATION...BENTLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
318 PM EDT MON JUL 13 2015
.SYNOPSIS...
ISSUED AT 1133 AM EDT MON JUL 12 2015
THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS THE AREA LATER THIS
AFTERNOON AND EVENING WITH SEVERE WEATHER POSSIBLE ALONG AND SOUTH
OF US 30. AFTERNOON HIGHS WILL BE AROUND 80 IN SOUTH CENTRAL
MICHIGAN TO THE UPPER 80S INTO NORTHWEST AND WEST CENTRAL INDIANA.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 316 PM EDT MON JUL 13 2015
RAPID DESTABILIZATION HAS BEGUN ACROSS NORTHERN ILLINOIS AS EXPECTED
AT 18Z THIS AFTERNOON. THIS DESTABILIZATION WILL CONTINUE TO ADVECT
EASTWARD THROUGH THE AFTERNOON WITH THE WESTERN HALF OF OUR FORECAST
AREA INTO THE WARM SECTOR BY EARLY EVENING. 18Z DVN SPECIAL SOUNDING
SAMPLED NEARLY DRY ADIABATIC LAPSE RATES FROM H850 TO H500 AND
NEARLY 100 KNOTS OF FLOW ABOVE 300MB. WITH SURFACE TEMPERATURES IN
THE MID 80S AND DEWPOINTS IN THE UPPER 70S BENEATH THIS EML...EXPECT
EXTREME INSTABILITY OF 4000 TO 6000 J/KG BY 22Z. THIS INSTABILITY
COUPLED WITH DEEP LAYER SHEAR OF 55 TO 65 KNOTS WILL LEAD TO
EXPLOSIVE STORM DEVELOPMENT AND ORGANIZATION LATER THIS EVENING. HP
SUPERCELLS WILL BE THE PRIMARY STORM MODE FOR THE FIRST FEW HOURS
BEFORE STORMS CONGEAL INTO A FORWARD PROPAGATING MCS.
DURING THIS 22Z TO 02Z TIMEFRAME...SURFACE WINDS WILL REMAIN OUT OF
THE SSW WITH A STRENGTHENING WESTERLY LOW LEVEL JET. EXTREMELY LOW
LCLS COUPLED WITH THIS STRONG LOW LEVEL SHEAR WILL LEAD TO AN
ENHANCED TORNADIC RISK DURING THIS TIMEFRAME. ADDITIONALLY...A
STRONG TORNADO CANNOT BE RULED OUT...ESPECIALLY IF STRONGER 850 FLOW
(35 TO 40 KNOTS) FROM THE LATEST HRRR VERIFIES.
EACH RUN OF THE HRRR HAS ADVECTED THE WARM FRONT PROGRESSIVELY
FURTHER EAST...SO CANNOT RULE OUT A GREATER THREAT FURTHER NORTHEAST
THAN THE CURRENT AREA OF FOCUS WHICH IS ALONG AND SOUTH OF US 30 IN
INDIANA.
MOST OF THE CWA RECEIVED BETWEEN 1 AND 1.5 INCHES WITH THE ROUND OF
RAIN THIS MORNING. FLASH FLOODING APPEARS INCREASINGLY LIKELY THIS
EVENING WITH A VERY HIGH THETA E AIRMASS AND TRAINING STORMS
POSSIBLE. THEREFORE...WILL KEEP THE FLASH FLOOD WATCH IN EFFECT
THROUGH 06Z.
ONCE THESE STORMS MOVE THROUGH...ADDITIONAL STORMS ARE POSSIBLE LATE
TONIGHT AND INTO THE DAY TOMORROW AS THE FRONT DROPS SOUTH THROUGH
OUR AREA. EXPECT THE FRONT TO MOVE SOUTH OF OUR FORECAST AREA BEFORE
ENOUGH INSTABILITY DEVELOPS FOR SEVERE WEATHER WITHIN OUR CWA.
&&
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 316 PM EDT MON JUL 13 2015
ROBUST NRN STREAM DISTURBANCE OVR NRN MN WILL DIG SEWD
INTO THE ERN LAKES ON TUE. RESULTING TROUGH AMPLIFICATION ACRS THE
LAKES WILL SHUNT UNSTABLE LL THETA-E RIDGE SWWD UNDER PERSISTENT H5
RIDGE CNTRD ACRS E TX. HWVR RESPITE FM WET PATTN LIKELY FLEETING AS
SRN PLAINS RIDGE BLDS BACK NORTH AGAIN W/EWD FOLDING THETA-E RIDGE
XPCD DOWNSTREAM OF A SERIES OF AT TIMES CONVECTIVELY ENHANCED
DISTURBANCES EJECT OUT OF AMPLIFYING WRN US TROUGHING.
AS SUCH AND IN LIGHT OF GOOD INTERMODEL AGREEMENT REORDERED POPS/WX
FRI-SUN TO HIGHLIGHT BTR CHCS ACRS THE NORTH IN PROXIMITY TO IMPLIED
UPR JET STREAM ACRS LWR MI AND INVOF OSCILLATING SFC FNTL ZONE.
OTRWS VRY WARM TEMPS XPCD TO MANIFEST UNDERNEATH STEADILY NWD BLDG
UPR RIDGE AXIS AND NO DOUBT HOT...HUMID 90S LIKELY THIS WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 125 PM EDT MON JUL 13 2015
BOTH TERMINALS WILL BE ON THE NORTHEASTERN FRINGE OF THE BEST
THUNDERSTORM CHANCES THIS EVENING. THEREFORE HAVE KEPT ONLY A VCTS
MENTION AT THIS TIME. SCATTERED TO BROKEN CUMULUS FIELD EXPECTED
TO DEVELOP AHEAD OF THESE STORMS DURING THE LATE AFTERNOON/EARLY
EVENING WITH BASES BETWEEN 2KFT AND 3KFT. ANY STORMS WHICH DO
DEVELOP MAY BE SEVERE WITH STRONG WIND GUSTS. WILL AMEND TAF AS
NEEDED THIS EVENING IF EITHER TERMINAL APPEARS TO BE IMPACTED BY
STORMS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...FLASH FLOOD WATCH UNTIL 2 AM EDT /1 AM CDT/ TUESDAY FOR INZ003-
012-013-015-020-022>027-032>034.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...BENTLEY
SHORT TERM...BENTLEY
LONG TERM...T
AVIATION...BENTLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
125 PM EDT MON JUL 13 2015
.SYNOPSIS...
ISSUED AT 1133 AM EDT MON JUL 12 2015
THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS THE AREA LATER THIS
AFTERNOON AND EVENING WITH SEVERE WEATHER POSSIBLE ALONG AND SOUTH
OF US 30. AFTERNOON HIGHS WILL BE AROUND 80 IN SOUTH CENTRAL
MICHIGAN TO THE UPPER 80S INTO NORTHWEST AND WEST CENTRAL INDIANA.
&&
.UPDATE...
ISSUED AT 1131 AM EDT MON JUL 13 2015
GROWING CONCERN FOR SIGNIFICANT SEVERE WEATHER THIS
AFTERNOON...MAINLY SOUTH OF US 30. TEMPERATURES HAVE ALREADY JUMPED
INTO THE UPPER 70S ACROSS NORTHERN ILLINOIS IN THE WAKE OF MORNING
CONVECTION. EXPECT TEMPERATURES TO RISE QUICKLY IN OUR AREA BY EARLY
AFTERNOON. FULL SUN FOR SEVERAL HOURS AND EFFICIENT
EVAPOTRANSPORATION SHOULD RESULT IN MODERATE TO EXTREME
DESTABILIZATION ALONG AND WEST OF A MICHIGAN CITY TO FORT WAYNE
LINE. LAST FEW RUNS OF THE HRRR HAVE SUPPORTED THIS THINKING WITH
STORMS DEVELOPING ALONG THIS FRONT BY LATE AFTERNOON. IF STORMS
DEVELOP IN THAT ENVIRONMENT...SUPERCELLS WILL BE THE PRIMARY STORM
MODE WITH 0-6 KM SHEAR IN EXCESS OF 50 KNOTS...STEEP MID LEVEL LAPSE
RATES...AND SIGNIFICANT TURNING OF THE WINDS WITH HEIGHT. TORNADOES
WILL ALSO BE POSSIBLE IN THIS SCENARIO GIVEN SOUTHERLY SURFACE WINDS
AND AN INCREASINGLY STRONG LOW LEVEL JET FROM THE WEST. MAY NEED TO
ADD SEVERE WORDING TO THE GRIDS WITHIN THE NEXT FEW HOURS IF
DESTABILIZATION BEGINS AS EXPECTED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 458 AM EDT MON JUL 13 2015
INTERESTING CONDITIONAL SEVERE EPISODE IN THE MAKE WITH NOTABLE
VARIABLES WHICH INCLUDE ONGOING SEVERE UPSTREAM CONVECTION ACRS
SRN/CNTL WI AND RESULTANT OUTFLOWS/BOUNDARIES AND CONVECTIVE
RENEWAL TIMING UPSTREAM BY MID/LATE AFTN WITH LOW POTNL FOR
DUAL/CONSECUTIVE CONVECTIVE COMPLEXES WITH THE LATTER NOT TO TRACK
THROUGH REGION UNTIL EARLY TUE AM...SEVERAL HOURS AFTER FIRST.
WILL FOCUS PRIMARILY ON THE FIRST TWO EPISODES WITH MAINTENANCE OF
CONVECTION FAVORED ALONG SHARP INSTABILITY/ISODROSOTHERMAL
GRADIENT WHICH SHOULD FOCUS WI BOWING SEGMENT APEX OF WI SQUALL
LINE ADVANCEMENT MORE RIGHT/SRLY WITH TIME...ADVANCING INTO WRN
CWA AFTER 12 UTC. STRENGTHENING WNWLY STEERING FLOW SHOULD ALSO
ALLOW EWD SPREAD THROUGH SCNTL CWA THROUGH AM HOURS AS STORMS
BECOME ELEVATED INTO ERN FRINGES OF WARM ADVECTION LEAF. PRIMARY
COMPOSITE OUTFLOW CORE TO LIKELY EXTEND NW/SE FM NRN IL TO WCNTL
IN. ESTABLISHED RICH POOL OF LWR/MID 70S SFC DPS ACRS MID MS VLY
WITH ERN BOUNDARY THROUGH NERN IL TO SRN IN. AS UPSTREAM SWRLY
FLOW STRENGTHENS LATER TODAY STRONG THETA-E ADVECTION INTO
SWRN/SRN CWA...ENHANCED FURTHER BY EFFECTIVE CNTL IL
EVAPOTRANSPIRATIVE PROCESSES...WILL FOCUS STRONG SFC BASED
INSTABILITY RESERVOIR /5000+ J/KG IN SWEPT ARC S-SW- W-NW OF CWA
BY MID/LATE AFTN. MEANWHILE STRENGTHENING AND VEERING MID
TROPOSPHERIC FLOW TO 50-60KTS. FOCUS FOR INITIATION UPSTREAM ACRS
WI IN MID/LATE AFTN HOURS APPEARS TIED TO EJECTION OF DUMBELLED
SHORTWAVE FEATURE ACRS NRN MN TIED TO PRESENTLY REXED WAVE NEAR
ND/SASK/MAN BORDERS. AS LEAD SHORTWAVE ENTERS RAPID CONFLUENCY
BTWN HUDSON BAY VORTEX AND STOIC NRN TX RIDGE. SHOULD BE
SUFFICIENT INDUCEMENT TO CONVECT WITH SUBSEQUENT/RAPID
INTENSIFICATION...WITH EVOLUTION INTO LINEAR SEGMENT/S/ BY EVENING
AND ENTRY INTO NWRN/WRN CWA BYND 00 UTC. DEEP LYR SHEAR ON ORDER
OF 45 KTS FAR SWRN CWA TO 30 KTS NE ALONG WITH PRESENTATION OF
INSTABILITY FAVORS SWRN/SRN CWA FOR SEVERE WITH DAMAGING WIND
GUSTS LARGEST RISK GIVEN MID LEVEL SPEEDS ENTRAINED INTO REAR
INFLOWS. HIGHLY CONDITIONAL NATURE OF THIRD LATE PD 2 EPSIODE TOO
UNCERTAIN AND DWINDLE SCT TSRA/HIR SHRA POPS TO CHC BYND 06 UTC.
LACK OF STRONG DESTABILZATION DOWNSTREAM OF CONVECTION TRAVERSING
SRN LK MICHIGAN SHOULD KEEP STORMS ACRS NERN CWA BLO SVR LIMITS.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 458 AM EDT MON JUL 13 2015
LONG TERM FORECAST FAIRLY QUIET FROM A RELATIVE PERSPECTIVE. MAIN
VORTICITY LOBE AND ASSOCIATED SECONDARY LOW LEVEL FRONTAL BOUNDARY
WILL PUSH THROUGH OUR AREA DURING THE DAY TUESDAY. PRIMARY THETA-E
RIDGE LONG GONE BY THAT POINT BUT ENOUGH RESIDUAL MOISTURE TO TOUCH
OFF SCT/NUM SHOWERS...ESPECIALLY IN OUR SOUTHERN ZONES. ALSO SOME
MARGINAL INSTABILITY IN THOSE SOUTHERN COUNTIES SO WOULD NOT BE
SURPRISED TO SEE SOME EMBEDDED THUNDER. QPF AMOUNTS WILL BE FAIRLY
LIGHT BUT THE HIGHEST AMOUNTS (0.25-0.5 INCHES) WILL BE IN THE SOUTH
AND MAY PROLONG FLOODING DUE TO SHORT TERM CONVECTION.
WED/THURS STILL LOOKING DRY AS GREAT LAKES RECEIVE A HEALTHY DOSE OF
AVA/SUBSIDENCE IN THE WAKE OF DEPARTING TROUGH AXIS. NORTHEAST FLOW
WILL YIELD A SLIGHT COOL DOWN BUT THERMAL PROFILES NOT PARTICULARLY
COLD AND WILL BE AT LEAST PARTIALLY OFFSET BY A FAIR AMOUNT OF SOLAR
INSOLATION. KEPT HIGHS IN THE UPPER 70S TO AROUND 80F. RETURN TO
MORE ACTIVE WEATHER BY THE END OF THE WEEK AS A MUCH WARMER AND
MOISTURE-LADEN AIRMASS FOLDS BACK INTO THE OHIO VALLEY COURTESY OF
STALWART SOUTHERN PLAINS RIDGE. WESTERLY MID/UPPER LEVEL FLOW WILL
BRING ANOTHER PARADE OF LOW AMPLITUDE SYSTEMS INTO THE WEEKEND BUT
(NOT SURPRISINGLY) MEDIUM RANGE MODELS CONTINUE TO STRUGGLE
IMMENSELY WITH EXACT TIMING AND PLACEMENT. WILL CONTINUE TO HOLD
WITH LOW CHANCE POPS UNTIL DETAILS CAN BE SORTED OUT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 125 PM EDT MON JUL 13 2015
BOTH TERMINALS WILL BE ON THE NORTHEASTERN FRINGE OF THE BEST
THUNDERSTORM CHANCES THIS EVENING. THEREFORE HAVE KEPT ONLY A VCTS
MENTION AT THIS TIME. SCATTERED TO BROKEN CUMULUS FIELD EXPECTED
TO DEVELOP AHEAD OF THESE STORMS DURING THE LATE AFTERNOON/EARLY
EVENING WITH BASES BETWEEN 2KFT AND 3KFT. ANY STORMS WHICH DO
DEVELOP MAY BE SEVERE WITH STRONG WIND GUSTS. WILL AMEND TAF AS
NEEDED THIS EVENING IF EITHER TERMINAL APPEARS TO BE IMPACTED BY
STORMS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR INZ003-012-013-015-
020-022>027-032>034.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
UPDATE...BENTLEY
SYNOPSIS...MURPHY
SHORT TERM...MURPHY
LONG TERM...AGD
AVIATION...BENTLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1133 AM EDT MON JUL 13 2015
.SYNOPSIS...
ISSUED AT 1133 AM EDT MON JUL 12 2015
THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS THE AREA LATER THIS
AFTERNOON AND EVENING WITH SEVERE WEATHER POSSIBLE ALONG AND SOUTH
OF US 30. AFTERNOON HIGHS WILL BE AROUND 80 IN SOUTH CENTRAL
MICHIGAN TO THE UPPER 80S INTO NORTHWEST AND WEST CENTRAL INDIANA.
&&
.UPDATE...
ISSUED AT 1131 AM EDT MON JUL 13 2015
GROWING CONCERN FOR SIGNIFICANT SEVERE WEATHER THIS
AFTERNOON...MAINLY SOUTH OF US 30. TEMPERATURES HAVE ALREADY JUMPED
INTO THE UPPER 70S ACROSS NORTHERN ILLINOIS IN THE WAKE OF MORNING
CONVECTION. EXPECT TEMPERATURES TO RISE QUICKLY IN OUR AREA BY EARLY
AFTERNOON. FULL SUN FOR SEVERAL HOURS AND EFFICIENT
EVAPOTRANSPORATION SHOULD RESULT IN MODERATE TO EXTREME
DESTABILIZATION ALONG AND WEST OF A MICHIGAN CITY TO FORT WAYNE
LINE. LAST FEW RUNS OF THE HRRR HAVE SUPPORTED THIS THINKING WITH
STORMS DEVELOPING ALONG THIS FRONT BY LATE AFTERNOON. IF STORMS
DEVELOP IN THAT ENVIRONMENT...SUPERCELLS WILL BE THE PRIMARY STORM
MODE WITH 0-6 KM SHEAR IN EXCESS OF 50 KNOTS...STEEP MID LEVEL LAPSE
RATES...AND SIGNIFICANT TURNING OF THE WINDS WITH HEIGHT. TORNADOES
WILL ALSO BE POSSIBLE IN THIS SCENARIO GIVEN SOUTHERLY SURFACE WINDS
AND AN INCREASINGLY STRONG LOW LEVEL JET FROM THE WEST. MAY NEED TO
ADD SEVERE WORDING TO THE GRIDS WITHIN THE NEXT FEW HOURS IF
DESTABILIZATION BEGINS AS EXPECTED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 458 AM EDT MON JUL 13 2015
INTERESTING CONDITIONAL SEVERE EPISODE IN THE MAKE WITH NOTABLE
VARIABLES WHICH INCLUDE ONGOING SEVERE UPSTREAM CONVECTION ACRS
SRN/CNTL WI AND RESULTANT OUTFLOWS/BOUNDARIES AND CONVECTIVE
RENEWAL TIMING UPSTREAM BY MID/LATE AFTN WITH LOW POTNL FOR
DUAL/CONSECUTIVE CONVECTIVE COMPLEXES WITH THE LATTER NOT TO TRACK
THROUGH REGION UNTIL EARLY TUE AM...SEVERAL HOURS AFTER FIRST.
WILL FOCUS PRIMARILY ON THE FIRST TWO EPISODES WITH MAINTENANCE OF
CONVECTION FAVORED ALONG SHARP INSTABILITY/ISODROSOTHERMAL
GRADIENT WHICH SHOULD FOCUS WI BOWING SEGMENT APEX OF WI SQUALL
LINE ADVANCEMENT MORE RIGHT/SRLY WITH TIME...ADVANCING INTO WRN
CWA AFTER 12 UTC. STRENGTHENING WNWLY STEERING FLOW SHOULD ALSO
ALLOW EWD SPREAD THROUGH SCNTL CWA THROUGH AM HOURS AS STORMS
BECOME ELEVATED INTO ERN FRINGES OF WARM ADVECTION LEAF. PRIMARY
COMPOSITE OUTFLOW CORE TO LIKELY EXTEND NW/SE FM NRN IL TO WCNTL
IN. ESTABLISHED RICH POOL OF LWR/MID 70S SFC DPS ACRS MID MS VLY
WITH ERN BOUNDARY THROUGH NERN IL TO SRN IN. AS UPSTREAM SWRLY
FLOW STRENGTHENS LATER TODAY STRONG THETA-E ADVECTION INTO
SWRN/SRN CWA...ENHANCED FURTHER BY EFFECTIVE CNTL IL
EVAPOTRANSPIRATIVE PROCESSES...WILL FOCUS STRONG SFC BASED
INSTABILITY RESERVOIR /5000+ J/KG IN SWEPT ARC S-SW- W-NW OF CWA
BY MID/LATE AFTN. MEANWHILE STRENGTHENING AND VEERING MID
TROPOSPHERIC FLOW TO 50-60KTS. FOCUS FOR INITIATION UPSTREAM ACRS
WI IN MID/LATE AFTN HOURS APPEARS TIED TO EJECTION OF DUMBELLED
SHORTWAVE FEATURE ACRS NRN MN TIED TO PRESENTLY REXED WAVE NEAR
ND/SASK/MAN BORDERS. AS LEAD SHORTWAVE ENTERS RAPID CONFLUENCY
BTWN HUDSON BAY VORTEX AND STOIC NRN TX RIDGE. SHOULD BE
SUFFICIENT INDUCEMENT TO CONVECT WITH SUBSEQUENT/RAPID
INTENSIFICATION...WITH EVOLUTION INTO LINEAR SEGMENT/S/ BY EVENING
AND ENTRY INTO NWRN/WRN CWA BYND 00 UTC. DEEP LYR SHEAR ON ORDER
OF 45 KTS FAR SWRN CWA TO 30 KTS NE ALONG WITH PRESENTATION OF
INSTABILITY FAVORS SWRN/SRN CWA FOR SEVERE WITH DAMAGING WIND
GUSTS LARGEST RISK GIVEN MID LEVEL SPEEDS ENTRAINED INTO REAR
INFLOWS. HIGHLY CONDITIONAL NATURE OF THIRD LATE PD 2 EPSIODE TOO
UNCERTAIN AND DWINDLE SCT TSRA/HIR SHRA POPS TO CHC BYND 06 UTC.
LACK OF STRONG DESTABILZATION DOWNSTREAM OF CONVECTION TRAVERSING
SRN LK MICHIGAN SHOULD KEEP STORMS ACRS NERN CWA BLO SVR LIMITS.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 458 AM EDT MON JUL 13 2015
LONG TERM FORECAST FAIRLY QUIET FROM A RELATIVE PERSPECTIVE. MAIN
VORTICITY LOBE AND ASSOCIATED SECONDARY LOW LEVEL FRONTAL BOUNDARY
WILL PUSH THROUGH OUR AREA DURING THE DAY TUESDAY. PRIMARY THETA-E
RIDGE LONG GONE BY THAT POINT BUT ENOUGH RESIDUAL MOISTURE TO TOUCH
OFF SCT/NUM SHOWERS...ESPECIALLY IN OUR SOUTHERN ZONES. ALSO SOME
MARGINAL INSTABILITY IN THOSE SOUTHERN COUNTIES SO WOULD NOT BE
SURPRISED TO SEE SOME EMBEDDED THUNDER. QPF AMOUNTS WILL BE FAIRLY
LIGHT BUT THE HIGHEST AMOUNTS (0.25-0.5 INCHES) WILL BE IN THE SOUTH
AND MAY PROLONG FLOODING DUE TO SHORT TERM CONVECTION.
WED/THURS STILL LOOKING DRY AS GREAT LAKES RECEIVE A HEALTHY DOSE OF
AVA/SUBSIDENCE IN THE WAKE OF DEPARTING TROUGH AXIS. NORTHEAST FLOW
WILL YIELD A SLIGHT COOL DOWN BUT THERMAL PROFILES NOT PARTICULARLY
COLD AND WILL BE AT LEAST PARTIALLY OFFSET BY A FAIR AMOUNT OF SOLAR
INSOLATION. KEPT HIGHS IN THE UPPER 70S TO AROUND 80F. RETURN TO
MORE ACTIVE WEATHER BY THE END OF THE WEEK AS A MUCH WARMER AND
MOISTURE-LADEN AIRMASS FOLDS BACK INTO THE OHIO VALLEY COURTESY OF
STALWART SOUTHERN PLAINS RIDGE. WESTERLY MID/UPPER LEVEL FLOW WILL
BRING ANOTHER PARADE OF LOW AMPLITUDE SYSTEMS INTO THE WEEKEND BUT
(NOT SURPRISINGLY) MEDIUM RANGE MODELS CONTINUE TO STRUGGLE
IMMENSELY WITH EXACT TIMING AND PLACEMENT. WILL CONTINUE TO HOLD
WITH LOW CHANCE POPS UNTIL DETAILS CAN BE SORTED OUT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 730 AM EDT MON JUL 13 2015
UPSTREAM CONVECTION INVOF KSBN AND LINEAR COMPLEX OVR SRN LK MI
REQUIRES TSRA MENTION FROM START AT KSBN THROUGH 15 UTC. TIMING OF
LINE TO KFWA ROUGHLY AROUND 15 UTC. PERTURBED MOIST BOUNDARY
LAYER AND PRECIP SHOULD CONTINUE TO SUPPORT FUELING/ALTERNATE CIGS
IF NOT BRIEF IFR UNTIL PASSAGE OF TSRA. THEREAFTER...GREAT DEAL OF
UNCERTAINTY ESPECIALLY WITH RESPECT TO TIMING AND POTNL FOR
RENEWED CONVECTION. FOR NOW COVER WITH VCTS AT 02/04 UTC FOR
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR INZ003-012-013-015-
020-022>027-032>034.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
UPDATE...BENTLEY
SYNOPSIS...MURPHY
SHORT TERM...MURPHY
LONG TERM...AGD
AVIATION...MURPHY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1132 PM CDT SUN JUL 12 2015
.SHORT TERM /TONIGHT/...
ISSUED AT 337 PM CDT SUN JUL 12 2015
MAIN ISSUE OVERNIGHT IS THE THREAT OF THUNDERSTORMS...SOME OF
WHICH COULD BE SEVERE.
FRONTAL BOUNDARY ALIGNS ROUGHLY WITH PERSISTENT STRATUS
FIELD...AND DEWPOINTS HAVE POOLED JUST UPSTREAM FROM THIS
BOUNDARY. CLOSEST ACTIVE CONVECTION IS STILL IN NORTHERN
MINNESOTA...BUT SHORT WAVE TROF IS APPROACHING SOUTH DAKOTA
MINNESOTA LINE AT THIS TIME AND SHOULD ENHANCE CONVECTIVE
COVERAGE. MOST CONVECTIVE ALLOWING MODELS KEEP MAIN MCS EAST OF
THIS FORECAST AREA BUT THE HRRR HAS BEEN INDICATING A POSSIBILITY
OF ISOLATED STORMS ALONG THE SOUTHWESTERN END OF THE ADVANCING
CONVECTION. IF THESE FORM IT WILL QUICKLY GO SEVERE WITH LARGE
HAIL AND WIND THE PRIMARY THREAT. MAIN MCS SHOULD MOVE PAST THE
AREA BY 12 UTC AND FRONT DOESN`T REALLY MOVE MUCH BY THEN.
.LONG TERM /MONDAY THROUGH SUNDAY/...
ISSUED AT 337 PM CDT SUN JUL 12 2015
HOT AND HUMID CONDITIONS CONTINUE ON MONDAY OVER THE SOUTHERN
HALF OF THE FORECAST AREA AND RAIN CHANCES WEDNESDAY NIGHT INTO
THURSDAY WERE THE MAIN ISSUES DURING THE EXTENDED PERIOD. LEANED
TOWARD A NAM12/ECMWF BLEND FOR TEMPS MONDAY INTO TUESDAY AND
CLOSER TO THE ECMWF/GFS THROUGH NEXT WEEKEND.
MONDAY AND TUESDAY...TWEAKED MAX TEMPS UP SLIGHTLY ALONG WITH DEW
POINTS OVER CENTRAL TO SOUTHEAST PORTIONS OF THE FORECAST AREA
AS THE COLD FRONT LOOKS TO BE A BIT SLOWER IN PROGRESSING ACROSS
THE STATE UNTIL LATER IN THE AFTERNOON. NOT A SIGNIFICANT AMOUNT
OF FORCING WITH THE FRONT...BUT ENOUGH THERE TO KEEP SLIGHT POPS
GOING IN THE AFTERNOON ACROSS THE EAST. SURFACE HIGH PRESSURE AND
UPPER LEVEL RIDGE HOLD IN PLACE ON TUESDAY WILL PROVIDE A MUCH
LESS HUMID AIR MASS OVER THE STATE. SOME MIXING LOOKS TO PUSH
TEMPS BACK INTO THE LOWER 90S OVER THE CENTRAL TO SOUTH
TUESDAY...BUT WITH LESS HUMIDITY NOT CONCERNED WITH EXTREME HEAT
INDEX VALUES.
WEDNESDAY INTO THURSDAY...LARGE UPPER LEVEL RIDGE PERSISTS ACROSS
THE CENTRAL U.S. THROUGH THE END OF THE WEEK. THE STRONGEST
SHORTWAVE AND BEST CONFIDENCE IN ANY PRECIPITATION DURING THE
EXTENDED IS WEDNESDAY NIGHT INTO THURSDAY. ECMWF AND GFS ARE IN
SOMEWHAT GOOD AGREEMENT WRT TO PRECIP CHANCES DURING THE
AFOREMENTIONED TIME FRAME. ANOTHER HEAVY RAIN EVENT LOOKS POSSIBLE
WITH WARM LAYER CLOUD DEPTHS AS HIGH AS 4000 METERS AND
PRECIPITABLE WATER NEAR 2 INCHES. LOWER CONFIDENCE WITH SEVERE
POTENTIAL WITH NO SIGNIFICANT AMOUNT OF INSTABILITY AND SHEAR
PRESENT.
FRIDAY THROUGH SUNDAY...TRENDED DRIER FRIDAY INTO SATURDAY AS
EXTENDED MODELS DO NOT HAVE A GOOD HANDLE OF TIMING AND LOCATION
OF WHEN AND IF ANY SHORTWAVE RIDING THE UPPER LEVEL RIDGE WILL
AFFECT THE FORECAST AREA. THUS...WENT WITH LESSER POPS LATE IN THE
PERIOD. PLUS WITH THE DRIER FORECAST...TRENDED WARMER FOR HIGHS
OVER THE WEEKEND AS THINKING LESS CLOUD COVER AND MODELS AT LEAST
HINTING ON STRONGER WAA.
&&
.AVIATION...13/06Z
ISSUED AT 1132 PM CDT SUN JUL 12 2015
MAINLY VFR CONDITIONS EXPECTED ACROSS TAF LOCATIONS BUT THERE WILL
BE PATCHY FOG AND ISOLD TSRA POSSIBLE INVOF KMCW AND KALO TAF SITES
BTWN 09Z AND 11Z.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM NOON TO 7 PM CDT MONDAY FOR ADAIR-ADAMS-APPANOOSE-
AUDUBON-BOONE-CARROLL-CASS-CLARKE-CRAWFORD-DALLAS-DAVIS-DECATUR-
GREENE-GUTHRIE-JASPER-LUCAS-MADISON-MAHASKA-MARION-MARSHALL-MONROE-
POLK-POWESHIEK-RINGGOLD-STORY-TAMA-TAYLOR-UNION-WAPELLO-WARREN-WAYNE.
&&
$$
SHORT TERM...HARDING
LONG TERM...PODRAZIK
AVIATION...FAB
...UPDATE TO AVIATION FORECAST DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 326 PM CDT SUN JUL 12 2015
UPPER HIGH REMAINS OVER THE SOUTHERN PLAINS, CENTERED OVER WEST
TEXAS EARLY THIS AFTERNOON, WITH UPPER LOW OVER SOUTHERN
SASKATCHEWAN. UPPER MOISTURE PLUME HAD WORKED ITS WAY NORTH AND EAST
ACROSS THE SOUTHERN ROCKIES AND INTO KANSAS WITH A FEW CUMULUS
RECENTLY NOTED IN HYS/HLC VICINITY NEAR WEAK LOW PRESSURE TROUGH.
DEWPOINTS REMAINED IN THE LOWER TO MIDDLE 70S IN LESS IMPRESSIVE
MIXING, AND TEMPS IN THE LOWER TO MIDDLE 90S.
WILL NEED TO WATCH LOCATIONS TO THE WEST IN THE NEXT FEW HOURS FOR
CONVECTIVE DEVELOPMENT. INHIBITION TO CONVECTION IS LOW THOUGH SO IS
FORCING. DEEP LAYER SHEAR REMAINS DECENT AND COULD KEEP SOME
ORGANIZATION TO STORMS THAT FORM TO THE WEST. LATEST HRRR DEVELOPS
SOME CONVECTION NEAR THE CUMULUS, THOUGH AS IT HAS BEEN RECENTLY,
ALREADY HAS STORMS BY THIS POINT AND IT HAS BEEN OVERZEALOUS ON
PRECIP IN RECENT DAYS. WILL GO AHEAD WITH A SMALL POP IN THE FAR
WEST AROUND 0Z.
NORTHERN UPPER LOW SINKS SOUTHEAST MONDAY, DRAGGING A WEAK COLD
FRONT INTO THE AREA IN THE AFTERNOON. MODELS CONTINUE TO SHOW
VARIOUS IDEAS ON LOW LEVEL THERMODYNAMICS, AND MIXING AGAIN IS NOT
VERY IMPRESSIVE, LIKELY KEEPING DEWPOINTS RATHER HIGH. HAVE LOWERED
MAX TEMPS A BIT BUT THIS STILL SHOULD PROVIDE AN ENVIRONMENT WITH
LIMITED CIN AND, LIKE TODAY, LIMITED FORCING. WITH A MORE DEFINED
BOUNDARY, WILL INCREASE POPS A BIT, WITH AGAIN SOME DEEP-LAYER SHEAR
SUPPORTING MAINLY DOWNBURST WINDS AND PERHAPS HAIL NEAR SEVERE
LEVELS. HEAT HEADLINES REMAIN, WITH APPARENT TEMPS AROUND 110 LIKELY
IN SOUTHERN AND EASTERN AREAS. AGAIN EXACT VALUES HARD TO NAIL DOWN
AND SOME ADJUSTMENTS IN WARNING AREAS COULD BE NEEDED LATER.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 326 PM CDT SUN JUL 12 2015
MODELS SHOW A LOW AMPLITUDE UPPER RIDGE REMAINING ANCHORED NEAR THE
SOUTHERN PLAINS THROUGH THE PERIOD. THIS PLACES THE FORECAST AREA
NEAR THE NORTHERN EDGE OF THE UPPER RIDGE WITH THE POTENTIAL FOR
SHORTWAVE ENERGY TO AFFECT THE REGION. HOWEVER THUNDERSTORM
CHANCES SHOULD BE CONDITIONAL AS MID LEVEL TEMPS WARM TO AROUND
+13C PROVIDING A SUBSTANTIAL CAP OVER THE BOUNDARY LAYER. IN
GENERAL THERE DOES NOT APPEAR TO BE A PERIOD WHERE PRECIP CHANCES
ARE OBVIOUS. THE FORECAST HAS SOME SMALL POPS IN FOR MONDAY NIGHT
AND TUESDAY WITH A WEAK BOUNDARY PROGGED TO BE IN THE AREA. MODELS
HAVE A BETTER DEFINED SHORTWAVE LIFTING THROUGH WESTERN KS AND
CENTRAL NEB ON WEDNESDAY. BECAUSE OF THIS HAVE SOME CHANCE POPS
GOING. THEN SLIGHT CHANCE POPS CONTINUE THROUGH THURSDAY TO
ACCOUNT FOR THE POSSIBILITY FOR SOME LOW LEVEL CONVERGENCE ALONG
A SURFACE TROUGH AXIS. THERE DOES NOT APPEAR TO BE ANY SIGNIFICANT
LIFT OR FORCING PROGGED BY THE MODELS FOR FRIDAY AND SATURDAY, SO
THE FORECAST REMAINS DRY. ANOTHER SURFACE TROUGH MAY MOVE INTO
EASTERN KS FOR SUNDAY SO HAVE SOME SLIGHT CHANCE POPS.
THE CENTER OF THE THERMAL RIDGE BACKS OFF TO THE SOUTHWEST BY
TUESDAY. HOWEVER THE FORECAST AREA IS LIKELY TO REMAIN WITHIN THE
THERMAL RIDGE AXIS THROUGH THE EXTENDED SO TEMPS ARE LIKELY TO
REMAIN HOT WHICH IS NOT UNCOMMON FOR THIS TIME OF YEAR. IN GENERAL
HAVE HIGHS IN THE 90S WITH LOWS IN THE LOWER AND MID 70S THROUGH
NEXT WEEKEND. WHILE THE MAGNITUDE OF THE HEAT MAY NOT BE HAS
EXTREME AS WE ARE EXPECTING TOMORROW, AFTERNOON HEAT INDICES ARE
LIKELY TO REMAIN AROUND 100 FOR THE FORESEEABLE FUTURE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1154 PM CDT SUN JUL 12 2015
THERE MAY BE SOME MARGINAL LOW-LEVEL WINDSHEAR WITH A
SOUTHWESTERLY 35KT LOW- LEVEL JET AT ABOUT 1000 FEET ABOVE THE
SURFACE AND SOUTH-SOUTHWEST SURFACE WINDS AROUND 5KTS. MAY SEE
SOME WIDELY SCATTERED TO SCATTERED THUNDERSTORMS DEVELOP AROUND
THE TERMINALS AFTER 21Z AND THROUGH 02Z TUE. OTHERWISE, EXPECT VFR
CONDITIONS THROUGH MOST OF THE PERIOD.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
EXCESSIVE HEAT WARNING FROM NOON TO 9 PM CDT MONDAY FOR KSZ012-
024-026-038>040-054>056-058-059.
HEAT ADVISORY UNTIL NOON CDT MONDAY FOR KSZ012-024-026-038>040-
054>056-058-059.
HEAT ADVISORY UNTIL 9 PM CDT MONDAY FOR KSZ008>011-020>023-
034>037.
&&
$$
SHORT TERM...65
LONG TERM...WOLTERS
AVIATION...GARGAN
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
349 PM EDT MON JUL 13 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 340 PM EDT MON JUL 13 2015
UPPER AND SFC TROUGHS OVER THE AREA WILL BEGIN TO QUICKLY MOVE SE
TONIGHT AND TUE...BRINGING A COLD FRONT THROUGH THIS EVENING INTO
TONIGHT AHEAD OF A SFC RIDGE MOVING IN FROM THE NW. SHOWERS HAVE
BEEN ONGOING ACROSS PARTS OF THE AREA TODAY AND ARE NOW MAINLY
CONFINED TO MORE NRN PARTS OF UPPER MI AND LAKE SUPERIOR. EXPECT
SOME REDEVELOPMENT OF SCATTERED SHOWERS AND THUNDERSTORMS LATE THIS
AFTERNOON AND EVENING AS THE UPPER TROUGH AND SFC COLD FRONT MOVE
IN. COULD SEE A STRONGER STORM OR TWO OVER SRN UPPER MI...DEPENDING
ON CONVECTIVE DEVELOPMENT...AS RUC ANALYSIS SHOWS 500 TO AROUND
1000J/KG OF CAPE AROUND AROUND 20KTS OF EFFECTIVE SHEAR...BUT
CERTAINLY NOT EXPECTING SEVERE STORMS. USED A BLEND OF HIGH-RES
GUIDANCE THROUGH TUE WITH A HIGHER LEVEL OF UNCERTAINTY LATE THIS
AFTERNOON INTO TONIGHT DUE TO CONVECTION.
MARINE FOG WILL BE PUSHED ONSHORE BEHIND THE FRONT LATE THIS EVENING
AND TONIGHT...WITH RAIN SHOWERS FORMING IN UPSLOPE AREAS BEHIND THE
FRONT. EXPECT MOST OR ALL PRECIP TO BE DONE BY TUE AFTERNOON...BUT
DID LAG CLOUDS BACK FROM MODEL GUIDANCE AS CLEARING IS OFTEN SLOWER
THAN SHOWN BY MODELS. HIGHS ON TUE WILL BE IN THE 60S TO MID
70S...WARMEST SOUTH.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 349 PM EDT MON JUL 13 2015
HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE UPPER GREAT LAKES
REGION AT THE START OF THE LONG TERM PERIOD AND REMAIN IN PLACE
INTO WEDNESDAY NIGHT BEFORE SHIFTING TO THE EAST OF THE AREA ON
THURSDAY. THIS WILL LEAD TO A PERIOD OF DRY WEATHER AND BELOW NORMAL
TEMPERATURES FOR THE U.P. EXPECT SKIES TO BE MOSTLY CLEAR DURING
THIS PERIOD...ALTHOUGH THERE ARE HINTS OF SOME HIGH CLOUDS
STREAMING ACROSS THE AREA ON WEDNESDAY MORNING AND THEN A FEW
DIURNAL CU OVER THE WESTERN HALF OF THE U.P. ON WEDNESDAY
AFTERNOON.
ON THURSDAY...THE SURFACE RIDGE WILL BE DEPARTING BUT THERE WILL BE
ENOUGH DRY AIR IN PLACE TO LEAD TO ANOTHER NICE DAY ACROSS THE
AREA (TEMPERATURES RETURNING TO NORMAL). WILL LIKELY SEE INCREASING
HIGH CLOUDS THROUGH THE DAY AHEAD OF AN APPROACHING SHORTWAVE AND
BROAD SURFACE TROUGH THAT WILL MOVE THROUGH THE AREA THURSDAY NIGHT
INTO FRIDAY. MODELS FAIRLY CONSISTENT ON THIS IDEA...ALTHOUGH THEY
ARE VARYING ON THE TIMING/LOCATION OF THE BEST FORCING AS IT MOVES
THROUGH. WILL TRY TO SHOW A LITTLE BETTER TIMING...MAINLY IN THE
LATE THURSDAY NIGHT AND FRIDAY MORNING PERIOD...WITH THE WAVE
MOVING OUT OF THE AREA FRIDAY AFTERNOON/EVENING.
FRIDAY NIGHT INTO SATURDAY IS A LITTLE MORE UNCERTAIN...AS MODELS
ARE INCONSISTENT ON THE SUBTLE FEATURES (WHICH IS TO BE EXPECTED AT
5 DAYS OUT). OVERALL...IT APPEARS THAT A WEAK UPPER RIDGE WILL
SLIDE EAST ACROSS THE AREA ON SATURDAY AND WILL KEEP POPS BELOW
CLIMO FOR THIS TIME OF YEAR. IT DOES LOOK LIKE IT WILL BE
WARM/HUMID ON SATURDAY WITH HIGHS IN THE 80S AND DEWPOINTS IN THE
LOWER 60S. UNCERTAINTY REMAINS FOR THE SECOND HALF OF THE WEEKEND
AND INTO EARLY NEXT WEEK...AS THE MODELS ARE GIVING A VARIETY OF
SOLUTIONS FOR WAVE EJECTING EAST-NORTHEAST FROM THE UPPER TROUGH
OVER WESTERN CANADA AND POTENTIALLY THE PACIFIC NORTHWEST. WILL
FOLLOW A GENERAL CONSENSUS AT THIS POINT...WITH TEMPERATURES AT OR
SLIGHTLY ABOVE NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 139 PM EDT MON JUL 13 2015
EXPECT SOME IMPROVEMENT THIS AFTERNOON/EVENING BEFORE LOW LEVEL
MOISTURE SURGES IN BEHIND A COLD FRONT. LOWERED CIGS WILL PERSIST
INTO TUE...WITH IMPROVEMENT EXPECTED TOWARD THE END OF THE 18Z TAF
PERIOD. AM STILL UNCERTAIN ON EXTENT/HEIGHT OF CIGS THIS
AFTERNOON/EVENING AND ALSO ON EXTENT OF SHOWERS AND MAYBE SOME
THUNDER. WENT WITH A CONSENSUS APPROACH FOR THE AFTERNOON/EVENING
GIVEN THAT DECREASED CONFIDENCE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 340 PM EDT MON JUL 13 2015
A WEAK TROUGH MOVING THROUGH THE NRN LAKES TODAY INTO THIS EVENING
WILL KEEP WINDS BELOW 20 KNOTS. A COLD FRONT WILL DROP SOUTH ACROSS
LAKE SUPERIOR LATE TONIGHT...SHIFTING THE WINDS TO A NORTHERLY
DIRECTION. WINDS MAY INCREASE TO AROUND 20 KNOTS LATE TONIGHT INTO
TUE MORNING BEHIND THE FRONT BUT SHOULD DIMINISH TUE AFTERNOON. A
HIGH PRESSURE RIDGE WILL THEN MOVE OVER LAKE SUPERIOR FOR TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT AND KEEP WINDS LIGHT.
AREAS OF FOG WILL CONTINUE TO AFFECT LAKE SUPERIOR INTO TONIGHT AS
WINDS REMAIN RELATIVELY LIGHT AND ABUNDANT LOW LEVEL MOISTURE
REMAINS OVER THE REGION. SO...THE DENSE FOG ADVY REMAINS IN EFFECT
THROUGH TONIGHT. AS DRIER AIR AND STRONGER MIXING ARRIVE LATER
TUESDAY INTO TUESDAY NIGHT BEHIND THE COLD FRONT...EXPECT THE FOG TO
DISSIPATE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 8 AM EDT TUESDAY FOR LSZ263-264-266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...TITUS
LONG TERM...SRF
AVIATION...TITUS
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
340 PM EDT MON JUL 13 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 340 PM EDT MON JUL 13 2015
UPPER AND SFC TROUGHS OVER THE AREA WILL BEGIN TO QUICKLY MOVE SE
TONIGHT AND TUE...BRINGING A COLD FRONT THROUGH THIS EVENING INTO
TONIGHT AHEAD OF A SFC RIDGE MOVING IN FROM THE NW. SHOWERS HAVE
BEEN ONGOING ACROSS PARTS OF THE AREA TODAY AND ARE NOW MAINLY
CONFINED TO MORE NRN PARTS OF UPPER MI AND LAKE SUPERIOR. EXPECT
SOME REDEVELOPMENT OF SCATTERED SHOWERS AND THUNDERSTORMS LATE THIS
AFTERNOON AND EVENING AS THE UPPER TROUGH AND SFC COLD FRONT MOVE
IN. COULD SEE A STRONGER STORM OR TWO OVER SRN UPPER MI...DEPENDING
ON CONVECTIVE DEVELOPMENT...AS RUC ANALYSIS SHOWS 500 TO AROUND
1000J/KG OF CAPE AROUND AROUND 20KTS OF EFFECTIVE SHEAR...BUT
CERTAINLY NOT EXPECTING SEVERE STORMS. USED A BLEND OF HIGH-RES
GUIDANCE THROUGH TUE WITH A HIGHER LEVEL OF UNCERTAINTY LATE THIS
AFTERNOON INTO TONIGHT DUE TO CONVECTION.
MARINE FOG WILL BE PUSHED ONSHORE BEHIND THE FRONT LATE THIS EVENING
AND TONIGHT...WITH RAIN SHOWERS FORMING IN UPSLOPE AREAS BEHIND THE
FRONT. EXPECT MOST OR ALL PRECIP TO BE DONE BY TUE AFTERNOON...BUT
DID LAG CLOUDS BACK FROM MODEL GUIDANCE AS CLEARING IS OFTEN SLOWER
THAN SHOWN BY MODELS. HIGHS ON TUE WILL BE IN THE 60S TO MID
70S...WARMEST SOUTH.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 529 AM EDT MON JUL 13 2015
OUR OFF AND ON SHOWER/TS ACTIVITY WILL BE DIMINISHING SIGNIFICANTLY
AFTER TUESDAY MORNING...AND MAY BE MORE LIMITED THROUGH THE REST OF
THE FCST PERIOD IF THE NEXT COUPLE OF SYSTEMS ARE UNABLE TO BREAK
DOWN THE STUBBORN 500MB RIDGE ACROSS MUCH OF THE CENTRAL U.S.
EXPECT SOME BRIEF GUSTY WINDS TUESDAY AS THE DEEPENING SFC LOW OVER
N LOWER MI AT 12Z SINKS ACROSS LAKE ERIE...AND LARGE HIGH PRESSURE
PUSHES IN FROM CENTRAL CANADA. THIS WILL BE WHILE THE 500MB LOW OVER
N QUEBEC AND TROUGH EXTENDING ACROSS LOWER MI EXIT TOO.
PW VALUES WILL FALL FROM AN AVG 1.5IN AT 12Z TUESDAY TO 0.3IN
TUESDAY NIGHT AS 850MB TEMPS FALL TO AROUND 11C /FROM NEAR 16C/.
MODEL GUIDANCE FOLLOWS THIS TREND PRETTY WELL...AND LOWERING THE
OVERNIGHT TEMPS EVEN MORE FOR TUESDAY NIGHT MAY BE NECESSARY BY
LATER SHIFTS. CURRENTLY EXPECT TEMPS TO BOTTOM OUT IN THE MID 40S TO
RIGHT AROUND 50F...WARMEST ALONG THE GREAT LAKES SHORELINES. LOOK
FOR SLOWLY INCREASING MOISTURE DURING THE DAY WEDNESDAY. THE SFC
HIGH WILL BE DIRECTLY OVER UPPER MI WEDNESDAY AFTERNOON...BEFORE
SLOWLY CENTERING ACROSS LAKE HURON AND THE LOWER GREAT LAKES
THURSDAY AFTERNOON...AND THE NEW ENGLAND STATES THURSDAY EVENING.
A LARGE AREA OF HIGH PRESSURE OVER S CENTRAL AND THE N TO CENTRAL
PLAINS STATES THURSDAY EVENING WILL BE PRESENT THROUGH THE WEEKEND.
THE 500MB RIDGE ACROSS MUCH OF THE E TWO-THIRDS OF THE NATION LOOKS
TO BECOME MORE ZONAL OVER THE UPPER GREAT LAKES FRIDAY MORNING. THE
RIDGE WILL REBOUND SATURDAY. THERE ARE SOME SIGNIFICANT DIFFERENCES
BETWEEN THE GFS AND ECMWF LATE SUNDAY AFTERNOON INTO MONDAY. A
GENERAL MODEL BLEND LOOKS TO BE BEST THAT FAR OUT...WITH 20-40
PERCENT POPS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 139 PM EDT MON JUL 13 2015
EXPECT SOME IMPROVEMENT THIS AFTERNOON/EVENING BEFORE LOW LEVEL
MOISTURE SURGES IN BEHIND A COLD FRONT. LOWERED CIGS WILL PERSIST
INTO TUE...WITH IMPROVEMENT EXPECTED TOWARD THE END OF THE 18Z TAF
PERIOD. AM STILL UNCERTAIN ON EXTENT/HEIGHT OF CIGS THIS
AFTERNOON/EVENING AND ALSO ON EXTENT OF SHOWERS AND MAYBE SOME
THUNDER. WENT WITH A CONSENSUS APPROACH FOR THE AFTERNOON/EVENING
GIVEN THAT DECREASED CONFIDENCE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 340 PM EDT MON JUL 13 2015
A WEAK TROUGH MOVING THROUGH THE NRN LAKES TODAY INTO THIS EVENING
WILL KEEP WINDS BELOW 20 KNOTS. A COLD FRONT WILL DROP SOUTH ACROSS
LAKE SUPERIOR LATE TONIGHT...SHIFTING THE WINDS TO A NORTHERLY
DIRECTION. WINDS MAY INCREASE TO AROUND 20 KNOTS LATE TONIGHT INTO
TUE MORNING BEHIND THE FRONT BUT SHOULD DIMINISH TUE AFTERNOON. A
HIGH PRESSURE RIDGE WILL THEN MOVE OVER LAKE SUPERIOR FOR TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT AND KEEP WINDS LIGHT.
AREAS OF FOG WILL CONTINUE TO AFFECT LAKE SUPERIOR INTO TONIGHT AS
WINDS REMAIN RELATIVELY LIGHT AND ABUNDANT LOW LEVEL MOISTURE
REMAINS OVER THE REGION. SO...THE DENSE FOG ADVY REMAINS IN EFFECT
THROUGH TONIGHT. AS DRIER AIR AND STRONGER MIXING ARRIVE LATER
TUESDAY INTO TUESDAY NIGHT BEHIND THE COLD FRONT...EXPECT THE FOG TO
DISSIPATE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 8 AM EDT TUESDAY FOR LSZ263-264-266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...TITUS
LONG TERM...KF
AVIATION...TITUS
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
140 PM EDT MON JUL 13 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 507 AM EDT MON JUL 13 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A BORAD MID/UPPER LEVEL RIDGE
CENTERED OVER THE SRN PLAINS AND A TROUGH OVER SRN MANITOBA. AT THE
SFC...A FRONTAL BOUNDARY FROM SE NORTH DAKOTA THROUGH SE MN INTO NRN
IL. THE STRONGEST CONVECTION WITH A LARGE MCS THAT DEVELOPED OVER MN
HAS SLIDE SE INTO CNTRL/SRN WI ALONG AND NORTH OF THE FRONT AND
MUCAPE GRADIENT. SHOWERS AND EMBEDDED TSRA ASSOCIATED WITH THE
LEFTOVER MCV PERSISTED INTO WRN LAKE SUPERIOR AND WRN UPPER MI.
TODAY...RADR TRENDS AND SHORT RANGE HIGH RES MODELS SUGGEST THAT THE
SHRA/TSRA OVER WRN UPPER MI WILL CONTINUE TO GRADUALLY SLIDE TO THE
EAST EARLY THIS MORNING WHILE ALSO WEAKENING AS THE PCPN MOVES AWAY
FROM THE AREA OF GREATER INSTABILITY. HOWEVER...THE APPROACH OF A
WEAK SHRTWV IN ADVANCE OF THE MANITOBA TROUGH MAY RESULT IN
ADDITIONAL DEVELOPMENT BY LATE MORNING INTO THE EARLY AFTERNOON AS
DAYTIME HEATING INCREASES AND A WEAK SFC TROUGH MOVES THROUGH THAT
COULD ALSO INTERACT WITH LAKE BREEZE BOUNDARIES. OVERALL CONFIDENCE
IN PCPN TIMING/COVERAGE IS LOW GIVEN MODEL DIFFERENCES AND LINGERING
EFFECTS OF THE LARGE MCS. WITH FCST MLCAPE VALUES ONLY INTO THE 500-
1000 J/KG RANGE AND WEAK 0-6KM/0-1KM SHEAR MAINLY JUST BRIEF HEAVY
RAIN WOULD BE THE MAIN HAZARD.
TONIGHT...EXPECT THE MID LEVEL TROUGH INTO THE NRN LAKES TO
GRADUALLY SINK OFF TO THE SE. WITH THE LOSS OF DAYTIME INSTABILITY
AND ANY WEAK MID LEVEL FORCING WITH THE TROUGH...SHRA/TSRA WILL
DIMINISH FROM THE NW OVERNIGHT. THERE MAY BE SOME SHOWERS LATE INTO
THE NORTH AS THE COLD FRONT SLIDES INTO THE AREA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 529 AM EDT MON JUL 13 2015
OUR OFF AND ON SHOWER/TS ACTIVITY WILL BE DIMINISHING SIGNIFICANTLY
AFTER TUESDAY MORNING...AND MAY BE MORE LIMITED THROUGH THE REST OF
THE FCST PERIOD IF THE NEXT COUPLE OF SYSTEMS ARE UNABLE TO BREAK
DOWN THE STUBBORN 500MB RIDGE ACROSS MUCH OF THE CENTRAL U.S.
EXPECT SOME BRIEF GUSTY WINDS TUESDAY AS THE DEEPENING SFC LOW OVER
N LOWER MI AT 12Z SINKS ACROSS LAKE ERIE...AND LARGE HIGH PRESSURE
PUSHES IN FROM CENTRAL CANADA. THIS WILL BE WHILE THE 500MB LOW OVER
N QUEBEC AND TROUGH EXTENDING ACROSS LOWER MI EXIT TOO.
PW VALUES WILL FALL FROM AN AVG 1.5IN AT 12Z TUESDAY TO 0.3IN
TUESDAY NIGHT AS 850MB TEMPS FALL TO AROUND 11C /FROM NEAR 16C/.
MODEL GUIDANCE FOLLOWS THIS TREND PRETTY WELL...AND LOWERING THE
OVERNIGHT TEMPS EVEN MORE FOR TUESDAY NIGHT MAY BE NECESSARY BY
LATER SHIFTS. CURRENTLY EXPECT TEMPS TO BOTTOM OUT IN THE MID 40S TO
RIGHT AROUND 50F...WARMEST ALONG THE GREAT LAKES SHORELINES. LOOK
FOR SLOWLY INCREASING MOISTURE DURING THE DAY WEDNESDAY. THE SFC
HIGH WILL BE DIRECTLY OVER UPPER MI WEDNESDAY AFTERNOON...BEFORE
SLOWLY CENTERING ACROSS LAKE HURON AND THE LOWER GREAT LAKES
THURSDAY AFTERNOON...AND THE NEW ENGLAND STATES THURSDAY EVENING.
A LARGE AREA OF HIGH PRESSURE OVER S CENTRAL AND THE N TO CENTRAL
PLAINS STATES THURSDAY EVENING WILL BE PRESENT THROUGH THE WEEKEND.
THE 500MB RIDGE ACROSS MUCH OF THE E TWO-THIRDS OF THE NATION LOOKS
TO BECOME MORE ZONAL OVER THE UPPER GREAT LAKES FRIDAY MORNING. THE
RIDGE WILL REBOUND SATURDAY. THERE ARE SOME SIGNIFICANT DIFFERENCES
BETWEEN THE GFS AND ECMWF LATE SUNDAY AFTERNOON INTO MONDAY. A
GENERAL MODEL BLEND LOOKS TO BE BEST THAT FAR OUT...WITH 20-40
PERCENT POPS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 139 PM EDT MON JUL 13 2015
EXPECT SOME IMPROVEMENT THIS AFTERNOON/EVENING BEFORE LOW LEVEL
MOISTURE SURGES IN BEHIND A COLD FRONT. LOWERED CIGS WILL PERSIST
INTO TUE...WITH IMPROVEMENT EXPECTED TOWARD THE END OF THE 18Z TAF
PERIOD. AM STILL UNCERTAIN ON EXTENT/HEIGHT OF CIGS THIS
AFTERNOON/EVENING AND ALSO ON EXTENT OF SHOWERS AND MAYBE SOME
THUNDER. WENT WITH A CONSENSUS APPROACH FOR THE AFTERNOON/EVENING
GIVEN THAT DECREASED CONFIDENCE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 515 AM EDT MON JUL 13 2015
A WEAK TROUGH MOVING THROUGH THE NRN LAKES TODAY INTO THIS EVENING
WILL KEEP WINDS BELOW 20 KNOTS. A COLD FRONT WILL DROP SOUTH ACROSS
LAKE SUPERIOR LATE TONIGHT...SHIFTING THE WINDS TO A NORTHERLY
DIRECTION. WINDS MAY INCREASE TO AROUND 20 KNOTS LATE TONIGHT INTO
TUE MORNING BEHIND THE FRONT BUT SHOULD DIMINISH TUE AFTERNOON. A
HIGH PRESSURE RIDGE WILL THEN MOVE OVER LAKE SUPERIOR FOR TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT AND KEEP WINDS LIGHT.
AREAS OF FOG WILL CONTINUE TO AFFECT LAKE SUPERIOR TODAY INTO
TONIGHT AS WINDS REMAIN RELATIVELY LIGHT AND ABUNDANT LOW LEVEL
MOISTURE REMAINS OVER THE REGION. SO...THE DENSE FOG ADVY REMAINS IN
EFFECT THROUGH TONIGHT. AS DRIER AIR AND STRONGER MIXING ARRIVE
LATER TUESDAY INTO TUESDAY NIGHT BEHIND THE COLD FRONT...EXPECT THE
FOG TO DISSIPATE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 8 AM EDT TUESDAY FOR LSZ263-264-266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...TITUS
MARINE...JLB
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1157 AM EDT MON JUL 13 2015
LATEST UPDATE...
MESOSCALE DISCUSSION
.MESOSCALE DISCUSSION...
ISSUED AT 1157 AM EDT MON JUL 13 2015
A BRIEF PERIOD OF STRONGER EAST/SOUTHEAST SFC WINDS WITH GUSTS TO
30-35 MPH HAVE BEEN NOTED AT A FEW OB SITES ON THE BACK SIDE OF
THE AREA SHOWERS AND THUNDERSTORMS THIS MORNING. THIS IS WAKE LOW
DRIVEN AND THE WINDS SHOULD RETURN TO UNIFORM SOUTHWEST 5 TO 15
MPH THIS AFTERNOON.
EXPECT A RELATIVE LULL IN CONVECTIVE POTENTIAL BEHIND DEPARTING
MORNING CONVECTION AND POSSIBLY SOME SUNSHINE AS WELL.
UNFORTUNATELY CONFIDENCE IS LOW REGARDING COVERAGE/INTENSITY OF
CONVECTION LATER TODAY AND TONIGHT DUE TO DIFFERING SOLUTIONS IN
SHORTER RANGE GUIDANCE. CONSENSUS HOWEVER SEEMS TO BE THAT IF
ANYTHING OCCURS IT WOULD BE AFTER 00Z WITH THE APPROACH OF THE MID
LEVEL SHORTWAVE AND SFC COLD FRONT FROM THE NORTHWEST.
THE LATEST RAP GUIDANCE SHOWS MU CAPES RISING TO 1500-2500 J/KG
ALONG THE I-94 CORRIDOR AFTER 18Z AND LINGERING WELL INTO THE
EVENING. 0-6 KM SHEAR VALUES ARE PROGGED TO BE 30-40 KNOTS SO
THERE IS SOME POTENTIAL FOR A CLUSTER OR TWO OF ORGANIZED STRONG
TO SVR STORMS WITH WIND GUSTS OVER 50 MPH TO RIDE NW TO SE
THROUGH SW LWR MI THIS EVENING.
.SYNOPSIS...
ISSUED AT 306 AM EDT MON JUL 13 2015
A WAVE OF LOW PRESSURE WILL TRACK SOUTHEASTWARD FROM THE NORTHERN
PLAINS AND INTO THE GREAT LAKES REGION TODAY INTO TUESDAY. THIS
SYSTEM WILL GENERATE SCATTERED SHOWERS AND THUNDERSTORMS. THE
MOISTURE WILL BE ON THE INCREASE AS THIS SYSTEM MOVES IN. A MUCH
DRIER AIRMASS ARRIVES ON WEDNESDAY AS THE WINDS SHIFT AND BECOME
NORTHERLY.
&&
.UPDATE...
ISSUED AT 750 AM EDT MON JUL 13 2015
STRONGER CONVECTION MOVING INTO WRN ZONES WILL CAUSE MORE
WIDESPREAD PRECIPITATION THAN CURRENTLY FORECAST. THE ZONES HAVE
BEEN UPDATED TO REFLECT THIS TREND.
UPDATE ISSUED AT 642 AM EDT MON JUL 13 2015
ADDED SOME DENSE FOG TO THE FORECAST THIS MORNING FOR THE AREA
SOUTH OF INTERSTATE 96. SEVERAL SITES SHOWING VALUES AROUND A
QUARTER MILE.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 306 AM EDT MON JUL 13 2015
MCS TRACKING THROUGH WRN WI...WILL DIVE SOUTHEAST WITH THE
STRONGEST CONVECTION STAYING SOUTHWEST OF THE CWA. THIS IS
EXPECTED TO HAPPEN BECAUSE THERE IS VERY LITTLE IN THE WAY OF
INSTABILITY PRESENT OVER SOUTHWEST LOWER MI BASED OFF THE MESO
ANALYSIS PAGE FROM SPC. WE SHOULD SEE ELEVATED SHOWERS WITH
EMBEDDED THUNDERSTORMS MOVING INTO MAINLY COASTAL LOCATIONS THIS
MORNING. WILL KEEP THE HIGH POPS GOING FOR WRN ZONES THIS
DECAYING MCS.
THIS AFTERNOON WILL NEED TO BE MONITORED FOR POSSIBLE STRONGER
CONVECTION. OVERALL IT APPEARS THE MODELS MAY HAVE TOO MUCH
INSTABILITY AS DEBRIS CLOUDS SHOULD PERSIST THROUGH MUCH OF THE
MORNING INTO THE EARLY AFTERNOON HOURS. DEEP LAYER SHEAR DOES
INCREASE...SO A RISK OF ORGANIZED CONVECTION IS ELEVATED. HOWEVER
THE COVERAGE OF STORMS MAY BE LIMITED UNTIL THE PEAK HEATING WHICH
MAY NOT OCCUR UNTIL MID TO LATE AFTERNOON. WILL HOLD ONTO THE
CHANCE FOR STORMS THIS AFTERNOON.
TONIGHT WE WILL SEE A MOIST ATMOSPHERE WITH PWATS OVER 1.75
INCHES...MID LEVEL HEIGHT FALLS AS A SHORTWAVE DIGS IN AND SOME
INSTABILITY. SUSPECT WE WILL SEE THE CONVECTION INCREASE AGAIN.
THIS INSTABILITY LOOKS LIMITED SO IT APPEARS UNLIKELY THAT WE WILL
SEE AN MCS DEVELOP. SOUTHWEST ZONES WILL SEE THE MOST INSTABILITY
AND BEST SHEAR SO THIS IS THE REGION THAT WILL NEED TO BE
MONITORED.
ADDITIONAL STORMS ARE POSSIBLE TUE AS THE MID LEVEL WAVE PUSHES
OFF TO THE EAST AND FLOW ALOFT IS CYC. WILL KEEP THE LOW CHC
GOING.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 306 AM EDT MON JUL 13 2015
THE LONG TERM PORTION OF THE FCST IS EXPECTED TO START OUT QUIET AND
SEASONABLE...BEFORE LIKELY HEATING UP A BIT AND BECOMING POTENTIALLY
UNSETTLED THROUGH NEXT WEEKEND.
WE ARE EXPECTING MAINLY DRY WEATHER FOR THE WED NIGHT AND THU TIME
PERIODS FOR THE AREA. THE TROUGH MOVING THROUGH ON TUE WILL BE LONG
GONE...AND WE WILL SEE A BIT OF A LONG WAVE RIDGE SLOWLY BUILD
TOWARD THE AREA IN RESPONSE TO TROUGHING MOVING IN OVER THE PACIFIC
NW. THE LOW LEVEL FLOW N/NE FLOW WILL BE FROM CANADA KEEPING THE
ATMOSPHERE DRY.
THE THREAT OF SHOWERS AND STORMS WILL INCREASE THU NIGHT AND
CONTINUE INTO THE DAY ON FRI. THE UPPER RIDGE WILL SHIFT EAST OF THE
AREA. THERE WILL BE A FAIRLY DECENT SHORT WAVE BEING EJECTED FROM
THE PACIFIC NW LONG WAVE TROUGH THAT WILL APPROACH THE AREA. THE
TRACK OF THIS WAVE HAS BEEN INCONSISTENT...ALTHOUGH THERE SEEMS TO
BE A CONSENSUS DEVELOPING OF IT MOVING THROUGH AT LEAST A PORTION OF
THE AREA. THE INSTABILITY WITH THIS DOES NOT LOOK TO BE IMPRESSIVE
AT THIS TIME WITH CLOUDS AND PCPN COMING IN THU NIGHT AND LIMITING
HEATING ON FRI.
THERE IS SOME POTENTIAL THAT SAT COULD END BEING MAINLY DRY WITH
PCPN CHCS STARTING TO INCREASE BY LATER ON SUN. THE THU NIGHT/FRI
WAVE WILL EXIT THE AREA LEAVING SOME SHORT WAVE RIDGING FOR AT LEAST
ON SAT. WE ARE NOT SO SURE ABOUT SUN STAYING DRY AS IT APPEARS WE
WILL HAVE SHORT WAVES/STORM COMPLEXES THAT WILL BE APPROACHING THE
REGION AROUND THE PERIPHERY OF THE RIDGE. THE RISING HEIGHTS WILL
HELP H850 TEMPS APPROACH 20C WHICH WOULD GIVE THE AREA A POTENTIAL
OF POSSIBLY HITTING 90 FOR THE FIRST TIME THIS SUMMER.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 750 AM EDT MON JUL 13 2015
TAFS FEATURE MORE IFR THAN PREVIOUSLY FORECASTED...ESPECIALLY
SOUTHERN TAF SITES FROM KAZO...KBTL TO KJXN. THIS SHOULD LAST FOR
AN HR OR TWO THIS AM DUE TO FOG AND LOW CLOUDS. ALSO THE
THUNDERSTORMS MOVING INTO THE KMKG REGION WILL FEATURE VARIABLE
GUSTY WINDS...ESPECIALLY WRN TAF SITES KMKG AND KAZO. VISIBILITIES
COULD BE REDUCED IFR LEVELS AS WELL. ONCE THIS INITIAL ROUND OF
STORMS MOVES THROUGH...IT WILL TAKE TIL MID TO LATE AFTERNOON FOR
NEW STORMS TO DEVELOP.
&&
.MARINE...
ISSUED AT 306 AM EDT MON JUL 13 2015
THUNDERSTORMS WILL POSE A RISK TO MARINERS THROUGH TUESDAY.
OVERALL IT APPEARS THE WINDS WILL REMAIN LOW ENOUGH TO LIMIT THE
POTENTIAL FOR HAZARDOUS MARINE CONDITIONS. SOUTHERLY WINDS
AHEAD OF THE APPROACHING STORMS THIS MORNING SHOULD SUPPORT THE
HIGHEST WAVES NEAR LITTLE AND BIG SABLE POINTS. THE PRESSURE
GRADIENT DROPS OFF TONIGHT. WILL NEED TO MONITOR THE NORTHERLY
COOL AND DRY FLOW FOR TUE NIGHT INTO WEDNESDAY AS SOMETIMES THE
WAVES END UP HIGHER THAN EXPECTED IN THESE SITUATION.
&&
.HYDROLOGY...
ISSUED AT 144 PM EDT SUN JUL 12 2015
ALL RIVER SITES ARE CURRENTLY WITHIN BANK...BUT STREAMFLOWS ACROSS
MUCH OF THE AREA ARE RUNNING ABOVE NORMAL. PORTIONS OF THE GRAND
AND KALAMAZOO RIVER BASINS ARE RUNNING MUCH ABOVE NORMAL.
RAINFALL THROUGH WEDNESDAY MORNING LOOKS TO AVERAGE FROM A QUARTER
TO A HALF INCH ACROSS PORTIONS OF CENTRAL LOWER MICHIGAN TO
POTENTIALLY AROUND AN INCH TOWARDS VAN BUREN COUNTY.
WE ARE EXPECTING A DECAYING AREA OF SHOWERS AND THUNDERSTORMS TO
MOVE TOWARDS AND INTO SOUTHWEST LOWER MICHIGAN LATE TONIGHT AND
MONDAY MORNING. SHOWERS AND STORMS WILL THEN LIKELY REFIRE MONDAY
AFTERNOON AND EVENING AHEAD OF A LOW PRESSURE SYSTEM MOVING
THROUGH THE REGION.
DEPENDING ON THE INTENSITY OF THE RAINFALL...OR IF RAINFALL OVER
PERFORMS JUST A BIT WE COULD BE LOOKING AT SOME RIVER ADVISORIES
ONCE AGAIN. THE HEAVIEST RAIN IN OUR AREA WILL BE IN AREAS SOUTH
OF INTERSTATE 96 MOST LIKELY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
MESOSCALE...MEADE
UPDATE...MJS
SYNOPSIS...MJS
SHORT TERM...MJS
LONG TERM...NJJ
AVIATION...MJS
HYDROLOGY...DUKE
MARINE...MJS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
740 AM EDT MON JUL 13 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 507 AM EDT MON JUL 13 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A BORAD MID/UPPER LEVEL RIDGE
CENTERED OVER THE SRN PLAINS AND A TROUGH OVER SRN MANITOBA. AT THE
SFC...A FRONTAL BOUNDARY FROM SE NORTH DAKOTA THROUGH SE MN INTO NRN
IL. THE STRONGEST CONVECTION WITH A LARGE MCS THAT DEVELOPED OVER MN
HAS SLIDE SE INTO CNTRL/SRN WI ALONG AND NORTH OF THE FRONT AND
MUCAPE GRADIENT. SHOWERS AND EMBEDDED TSRA ASSOCIATED WITH THE
LEFTOVER MCV PERSISTED INTO WRN LAKE SUPERIOR AND WRN UPPER MI.
TODAY...RADR TRENDS AND SHORT RANGE HIGH RES MODELS SUGGEST THAT THE
SHRA/TSRA OVER WRN UPPER MI WILL CONTINUE TO GRADUALLY SLIDE TO THE
EAST EARLY THIS MORNING WHILE ALSO WEAKENING AS THE PCPN MOVES AWAY
FROM THE AREA OF GREATER INSTABILITY. HOWEVER...THE APPROACH OF A
WEAK SHRTWV IN ADVANCE OF THE MANITOBA TROUGH MAY RESULT IN
ADDITIONAL DEVELOPMENT BY LATE MORNING INTO THE EARLY AFTERNOON AS
DAYTIME HEATING INCREASES AND A WEAK SFC TROUGH MOVES THROUGH THAT
COULD ALSO INTERACT WITH LAKE BREEZE BOUNDARIES. OVERALL CONFIDENCE
IN PCPN TIMING/COVERAGE IS LOW GIVEN MODEL DIFFERENCES AND LINGERING
EFFECTS OF THE LARGE MCS. WITH FCST MLCAPE VALUES ONLY INTO THE 500-
1000 J/KG RANGE AND WEAK 0-6KM/0-1KM SHEAR MAINLY JUST BRIEF HEAVY
RAIN WOULD BE THE MAIN HAZARD.
TONIGHT...EXPECT THE MID LEVEL TROUGH INTO THE NRN LAKES TO
GRADUALLY SINK OFF TO THE SE. WITH THE LOSS OF DAYTIME INSTABILITY
AND ANY WEAK MID LEVEL FORCING WITH THE TROUGH...SHRA/TSRA WILL
DIMINISH FROM THE NW OVERNIGHT. THERE MAY BE SOME SHOWERS LATE INTO
THE NORTH AS THE COLD FRONT SLIDES INTO THE AREA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 529 AM EDT MON JUL 13 2015
OUR OFF AND ON SHOWER/TS ACTIVITY WILL BE DIMINISHING SIGNIFICANTLY
AFTER TUESDAY MORNING...AND MAY BE MORE LIMITED THROUGH THE REST OF
THE FCST PERIOD IF THE NEXT COUPLE OF SYSTEMS ARE UNABLE TO BREAK
DOWN THE STUBBORN 500MB RIDGE ACROSS MUCH OF THE CENTRAL U.S.
EXPECT SOME BRIEF GUSTY WINDS TUESDAY AS THE DEEPENING SFC LOW OVER
N LOWER MI AT 12Z SINKS ACROSS LAKE ERIE...AND LARGE HIGH PRESSURE
PUSHES IN FROM CENTRAL CANADA. THIS WILL BE WHILE THE 500MB LOW OVER
N QUEBEC AND TROUGH EXTENDING ACROSS LOWER MI EXIT TOO.
PW VALUES WILL FALL FROM AN AVG 1.5IN AT 12Z TUESDAY TO 0.3IN
TUESDAY NIGHT AS 850MB TEMPS FALL TO AROUND 11C /FROM NEAR 16C/.
MODEL GUIDANCE FOLLOWS THIS TREND PRETTY WELL...AND LOWERING THE
OVERNIGHT TEMPS EVEN MORE FOR TUESDAY NIGHT MAY BE NECESSARY BY
LATER SHIFTS. CURRENTLY EXPECT TEMPS TO BOTTOM OUT IN THE MID 40S TO
RIGHT AROUND 50F...WARMEST ALONG THE GREAT LAKES SHORELINES. LOOK
FOR SLOWLY INCREASING MOISTURE DURING THE DAY WEDNESDAY. THE SFC
HIGH WILL BE DIRECTLY OVER UPPER MI WEDNESDAY AFTERNOON...BEFORE
SLOWLY CENTERING ACROSS LAKE HURON AND THE LOWER GREAT LAKES
THURSDAY AFTERNOON...AND THE NEW ENGLAND STATES THURSDAY EVENING.
A LARGE AREA OF HIGH PRESSURE OVER S CENTRAL AND THE N TO CENTRAL
PLAINS STATES THURSDAY EVENING WILL BE PRESENT THROUGH THE WEEKEND.
THE 500MB RIDGE ACROSS MUCH OF THE E TWO-THIRDS OF THE NATION LOOKS
TO BECOME MORE ZONAL OVER THE UPPER GREAT LAKES FRIDAY MORNING. THE
RIDGE WILL REBOUND SATURDAY. THERE ARE SOME SIGNIFICANT DIFFERENCES
BETWEEN THE GFS AND ECMWF LATE SUNDAY AFTERNOON INTO MONDAY. A
GENERAL MODEL BLEND LOOKS TO BE BEST THAT FAR OUT...WITH 20-40
PERCENT POPS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 737 AM EDT MON JUL 13 2015
SHOWERS AND AN INFLUX OF LOW LEVEL MOISTURE HAS DROPPED CIGS TO IFR
AT TIMES AT CMX AND SAW. HOWEVER...CONDITIONS HAD IMPROVED TO VFR AT
IWD BEHIND THE MCS THAT MOVED THROUGH OVERNIGHT. MORE SHOWERS AND
PERHAPS MVFR CONDITIONS MAY LINGER THROUGH MUCH OF THE MORNING AS
WELL AT CMX/SAW WITH THE MVFR CONDITIONS DOWN TO IFR AT TIMES. BUT
IN THE AFTERNOON...DAYTIME HEATING IS LIKELY TO CAUSE A RETURN TO
VFR WEATHER. THIS HEATING MAY ALSO CAUSE MORE SHOWERS AND PERHAPS A TS TO
DEVELOP AS WELL...ESPECIALLY AT IWD AND SAW AWAY FROM LAKE SUPERIOR
MODERATION. MVFR CONDITIONS WILL BE POSSIBLE AGAIN BY LATE EVENING
WITH LINGERING LOW LEVEL MOISTURE AND NOCTURNAL COOLING. AS WINDS
VEER TO THE NORTH BEHIND A COLD FRONT...UPSLOPE FLOW IS EXPECTED TO
DROP CIGS BACK TO IFR AT CMX AND SAW AND POSSIBLY AT IWD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 515 AM EDT MON JUL 13 2015
A WEAK TROUGH MOVING THROUGH THE NRN LAKES TODAY INTO THIS EVENING
WILL KEEP WINDS BELOW 20 KNOTS. A COLD FRONT WILL DROP SOUTH ACROSS
LAKE SUPERIOR LATE TONIGHT...SHIFTING THE WINDS TO A NORTHERLY
DIRECTION. WINDS MAY INCREASE TO AROUND 20 KNOTS LATE TONIGHT INTO
TUE MORNING BEHIND THE FRONT BUT SHOULD DIMINISH TUE AFTERNOON. A
HIGH PRESSURE RIDGE WILL THEN MOVE OVER LAKE SUPERIOR FOR TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT AND KEEP WINDS LIGHT.
AREAS OF FOG WILL CONTINUE TO AFFECT LAKE SUPERIOR TODAY INTO
TONIGHT AS WINDS REMAIN RELATIVELY LIGHT AND ABUNDANT LOW LEVEL
MOISTURE REMAINS OVER THE REGION. SO...THE DENSE FOG ADVY REMAINS IN
EFFECT THROUGH TONIGHT. AS DRIER AIR AND STRONGER MIXING ARRIVE
LATER TUESDAY INTO TUESDAY NIGHT BEHIND THE COLD FRONT...EXPECT THE
FOG TO DISSIPATE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 8 AM EDT TUESDAY FOR LSZ263-264-266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
529 AM EDT MON JUL 13 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 507 AM EDT MON JUL 13 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A BORAD MID/UPPER LEVEL RIDGE
CENTERED OVER THE SRN PLAINS AND A TROUGH OVER SRN MANITOBA. AT THE
SFC...A FRONTAL BOUNDARY FROM SE NORTH DAKOTA THROUGH SE MN INTO NRN
IL. THE STRONGEST CONVECTION WITH A LARGE MCS THAT DEVELOPED OVER MN
HAS SLIDE SE INTO CNTRL/SRN WI ALONG AND NORTH OF THE FRONT AND
MUCAPE GRADIENT. SHOWERS AND EMBEDDED TSRA ASSOCIATED WITH THE
LEFTOVER MCV PERSISTED INTO WRN LAKE SUPERIOR AND WRN UPPER MI.
TODAY...RADR TRENDS AND SHORT RANGE HIGH RES MODELS SUGGEST THAT THE
SHRA/TSRA OVER WRN UPPER MI WILL CONTINUE TO GRADUALLY SLIDE TO THE
EAST EARLY THIS MORNING WHILE ALSO WEAKENING AS THE PCPN MOVES AWAY
FROM THE AREA OF GREATER INSTABILITY. HOWEVER...THE APPROACH OF A
WEAK SHRTWV IN ADVANCE OF THE MANITOBA TROUGH MAY RESULT IN
ADDITIONAL DEVELOPMENT BY LATE MORNING INTO THE EARLY AFTERNOON AS
DAYTIME HEATING INCREASES AND A WEAK SFC TROUGH MOVES THROUGH THAT
COULD ALSO INTERACT WITH LAKE BREEZE BOUNDARIES. OVERALL CONFIDENCE
IN PCPN TIMING/COVERAGE IS LOW GIVEN MODEL DIFFERENCES AND LINGERING
EFFECTS OF THE LARGE MCS. WITH FCST MLCAPE VALUES ONLY INTO THE 500-
1000 J/KG RANGE AND WEAK 0-6KM/0-1KM SHEAR MAINLY JUST BRIEF HEAVY
RAIN WOULD BE THE MAIN HAZARD.
TONIGHT...EXPECT THE MID LEVEL TROUGH INTO THE NRN LAKES TO
GRADUALLY SINK OFF TO THE SE. WITH THE LOSS OF DAYTIME INSTABILITY
AND ANY WEAK MID LEVEL FORCING WITH THE TROUGH...SHRA/TSRA WILL
DIMINISH FROM THE NW OVERNIGHT. THERE MAY BE SOME SHOWERS LATE INTO
THE NORTH AS THE COLD FRONT SLIDES INTO THE AREA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 529 AM EDT MON JUL 13 2015
OUR OFF AND ON SHOWER/TS ACTIVITY WILL BE DIMINISHING SIGNIFICANTLY
AFTER TUESDAY MORNING...AND MAY BE MORE LIMITED THROUGH THE REST OF
THE FCST PERIOD IF THE NEXT COUPLE OF SYSTEMS ARE UNABLE TO BREAK
DOWN THE STUBBORN 500MB RIDGE ACROSS MUCH OF THE CENTRAL U.S.
EXPECT SOME BRIEF GUSTY WINDS TUESDAY AS THE DEEPENING SFC LOW OVER
N LOWER MI AT 12Z SINKS ACROSS LAKE ERIE...AND LARGE HIGH PRESSURE
PUSHES IN FROM CENTRAL CANADA. THIS WILL BE WHILE THE 500MB LOW OVER
N QUEBEC AND TROUGH EXTENDING ACROSS LOWER MI EXIT TOO.
PW VALUES WILL FALL FROM AN AVG 1.5IN AT 12Z TUESDAY TO 0.3IN
TUESDAY NIGHT AS 850MB TEMPS FALL TO AROUND 11C /FROM NEAR 16C/.
MODEL GUIDANCE FOLLOWS THIS TREND PRETTY WELL...AND LOWERING THE
OVERNIGHT TEMPS EVEN MORE FOR TUESDAY NIGHT MAY BE NECESSARY BY
LATER SHIFTS. CURRENTLY EXPECT TEMPS TO BOTTOM OUT IN THE MID 40S TO
RIGHT AROUND 50F...WARMEST ALONG THE GREAT LAKES SHORELINES. LOOK
FOR SLOWLY INCREASING MOISTURE DURING THE DAY WEDNESDAY. THE SFC
HIGH WILL BE DIRECTLY OVER UPPER MI WEDNESDAY AFTERNOON...BEFORE
SLOWLY CENTERING ACROSS LAKE HURON AND THE LOWER GREAT LAKES
THURSDAY AFTERNOON...AND THE NEW ENGLAND STATES THURSDAY EVENING.
A LARGE AREA OF HIGH PRESSURE OVER S CENTRAL AND THE N TO CENTRAL
PLAINS STATES THURSDAY EVENING WILL BE PRESENT THROUGH THE WEEKEND.
THE 500MB RIDGE ACROSS MUCH OF THE E TWO-THIRDS OF THE NATION LOOKS
TO BECOME MORE ZONAL OVER THE UPPER GREAT LAKES FRIDAY MORNING. THE
RIDGE WILL REBOUND SATURDAY. THERE ARE SOME SIGNIFICANT DIFFERENCES
BETWEEN THE GFS AND ECMWF LATE SUNDAY AFTERNOON INTO MONDAY. A
GENERAL MODEL BLEND LOOKS TO BE BEST THAT FAR OUT...WITH 20-40
PERCENT POPS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 124 AM EDT MON JUL 13 2015
SOME SHOWERS/EMBEDDED TS ON THE NRN FRINGE OF CONVECTIVE COMPLEX
MOVING THRU WI ARE LIKELY TO IMPACT IWD THE FIRST COUPLE HRS OF THE
FCST PERIOD...RESULTING IN SOME MVFR AND PERHAPS IFR CONDITIONS. THE
REMNANTS OF THESE SHOWERS MAY REACH CMX AND SAW AS WELL LATER...BUT
TS ARE NOT LIKELY ENUF AT THESE PLACES TO WARRANT A SPECIFIC MENTION
IN THE TAF. MVFR CONDITIONS ARE POSSIBLE AT THESE SITES AS WELL WITH
HUMID AIR AND NOCTURNAL COOLING...ESPECIALLY IF THE SHOWERS REACH
THESE AIRPORTS. MORE SHOWERS AND PERHAPS MVFR CONDITIONS MAY LINGER
THRU MUCH OF THE MRNG AS WELL ALONG WITH THE MVFR CONDITIONS. BUT IN
THE AFTN...DAYTIME HEATING IS LIKELY TO CAUSE A RETURN TO VFR WX.
THIS HEATING MAY ALSO CAUSE MORE SHOWERS AND PERHAPS A TS TO DEVELOP
AS WELL...ESPECIALLY AT IWD AND SAW AWAY FM LK SUP MODERATION. MVFR
CONDITIONS WL BE POSSIBLE AGAIN BY LATE EVNG WITH LINGERING LLVL
MSTR/NOCTURNAL COOLING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 515 AM EDT MON JUL 13 2015
A WEAK TROUGH MOVING THROUGH THE NRN LAKES TODAY INTO THIS EVENING
WILL KEEP WINDS BELOW 20 KNOTS. A COLD FRONT WILL DROP SOUTH ACROSS
LAKE SUPERIOR LATE TONIGHT...SHIFTING THE WINDS TO A NORTHERLY
DIRECTION. WINDS MAY INCREASE TO AROUND 20 KNOTS LATE TONIGHT INTO
TUE MORNING BEHIND THE FRONT BUT SHOULD DIMINISH TUE AFTERNOON. A
HIGH PRESSURE RIDGE WILL THEN MOVE OVER LAKE SUPERIOR FOR TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT AND KEEP WINDS LIGHT.
AREAS OF FOG WILL CONTINUE TO AFFECT LAKE SUPERIOR TODAY INTO
TONIGHT AS WINDS REMAIN RELATIVELY LIGHT AND ABUNDANT LOW LEVEL
MOISTURE REMAINS OVER THE REGION. SO...THE DENSE FOG ADVY REMAINS IN
EFFECT THROUGH TONIGHT. AS DRIER AIR AND STRONGER MIXING ARRIVE
LATER TUESDAY INTO TUESDAY NIGHT BEHIND THE COLD FRONT...EXPECT THE
FOG TO DISSIPATE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 8 AM EDT TUESDAY FOR LSZ263-264-266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
516 AM EDT MON JUL 13 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 507 AM EDT MON JUL 13 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A BORAD MID/UPPER LEVEL RIDGE
CENTERED OVER THE SRN PLAINS AND A TROUGH OVER SRN MANITOBA. AT THE
SFC...A FRONTAL BOUNDARY FROM SE NORTH DAKOTA THROUGH SE MN INTO NRN
IL. THE STRONGEST CONVECTION WITH A LARGE MCS THAT DEVELOPED OVER MN
HAS SLIDE SE INTO CNTRL/SRN WI ALONG AND NORTH OF THE FRONT AND
MUCAPE GRADIENT. SHOWERS AND EMBEDDED TSRA ASSOCIATED WITH THE
LEFTOVER MCV PERSISTED INTO WRN LAKE SUPERIOR AND WRN UPPER MI.
TODAY...RADR TRENDS AND SHORT RANGE HIGH RES MODELS SUGGEST THAT THE
SHRA/TSRA OVER WRN UPPER MI WILL CONTINUE TO GRADUALLY SLIDE TO THE
EAST EARLY THIS MORNING WHILE ALSO WEAKENING AS THE PCPN MOVES AWAY
FROM THE AREA OF GREATER INSTABILITY. HOWEVER...THE APPROACH OF A
WEAK SHRTWV IN ADVANCE OF THE MANITOBA TROUGH MAY RESULT IN
ADDITIONAL DEVELOPMENT BY LATE MORNING INTO THE EARLY AFTERNOON AS
DAYTIME HEATING INCREASES AND A WEAK SFC TROUGH MOVES THROUGH THAT
COULD ALSO INTERACT WITH LAKE BREEZE BOUNDARIES. OVERALL CONFIDENCE
IN PCPN TIMING/COVERAGE IS LOW GIVEN MODEL DIFFERENCES AND LINGERING
EFFECTS OF THE LARGE MCS. WITH FCST MLCAPE VALUES ONLY INTO THE 500-
1000 J/KG RANGE AND WEAK 0-6KM/0-1KM SHEAR MAINLY JUST BRIEF HEAVY
RAIN WOULD BE THE MAIN HAZARD.
TONIGHT...EXPECT THE MID LEVEL TROUGH INTO THE NRN LAKES TO
GRADUALLY SINK OFF TO THE SE. WITH THE LOSS OF DAYTIME INSTABILITY
AND ANY WEAK MID LEVEL FORCING WITH THE TROUGH...SHRA/TSRA WILL
DIMINISH FROM THE NW OVERNIGHT. THERE MAY BE SOME SHOWERS LATE INTO
THE NORTH AS THE COLD FRONT SLIDES INTO THE AREA.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 301 PM EDT SUN JUL 12 2015
NAM SHOWS A TROUGH ON THE WEST COAST...A RIDGE OVER THE
ROCKIES...SHORTWAVE OVER THE UPPER GREAT LAKES 00Z TUE. A COLD FRONT
MOVES THROUGH THE AREA MON NIGHT INTO TUE AND THEN WENT DRY FOR TUE
NIGHT AND WED. OVERALL...DID NOT MAKE TOO MANY CHANGES TO THE GOING
FORECAST FOR TEMPERATURES OR WEATHER.
IN THE EXTENDED...GFS AND ECMWF SHOW A BROAD 500 MB TROUGH IN THE
WESTERN U.S. AND A RIDGE ACROSS THE GULF COAST 12Z THU. THERE IS
ALSO A SHORTWAVE OVER THE NORTHERN PLAINS 12Z THU THAT MOVES INTO
THE UPPER GREAT LAKES 12Z FRI. BEHIND THIS SHORTWAVE...UPPER RIDGING
MOVES INTO THE UPPER GREAT LAKES ON SAT INTO SUN WITH SOME WARMER
AIR TRYING TO GET INTO THE AREA THIS NEXT WEEKEND. SFC FRONTS WILL
BE IN THE AREA WITH THE AREA BEING ON THE BOUNDARY BETWEEN VERY WARM
AND HUMID AIR TO THE SOUTH AND COOLER AND DRIER AIR TO THE NORTH AND
HAVING SOME POPS IN FOR THE EXTENDED SEEMS WARRANTED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 124 AM EDT MON JUL 13 2015
SOME SHOWERS/EMBEDDED TS ON THE NRN FRINGE OF CONVECTIVE COMPLEX
MOVING THRU WI ARE LIKELY TO IMPACT IWD THE FIRST COUPLE HRS OF THE
FCST PERIOD...RESULTING IN SOME MVFR AND PERHAPS IFR CONDITIONS. THE
REMNANTS OF THESE SHOWERS MAY REACH CMX AND SAW AS WELL LATER...BUT
TS ARE NOT LIKELY ENUF AT THESE PLACES TO WARRANT A SPECIFIC MENTION
IN THE TAF. MVFR CONDITIONS ARE POSSIBLE AT THESE SITES AS WELL WITH
HUMID AIR AND NOCTURNAL COOLING...ESPECIALLY IF THE SHOWERS REACH
THESE AIRPORTS. MORE SHOWERS AND PERHAPS MVFR CONDITIONS MAY LINGER
THRU MUCH OF THE MRNG AS WELL ALONG WITH THE MVFR CONDITIONS. BUT IN
THE AFTN...DAYTIME HEATING IS LIKELY TO CAUSE A RETURN TO VFR WX.
THIS HEATING MAY ALSO CAUSE MORE SHOWERS AND PERHAPS A TS TO DEVELOP
AS WELL...ESPECIALLY AT IWD AND SAW AWAY FM LK SUP MODERATION. MVFR
CONDITIONS WL BE POSSIBLE AGAIN BY LATE EVNG WITH LINGERING LLVL
MSTR/NOCTURNAL COOLING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 515 AM EDT MON JUL 13 2015
A WEAK TROUGH MOVING THROUGH THE NRN LAKES TODAY INTO THIS EVENING
WILL KEEP WINDS BELOW 20 KNOTS. A COLD FRONT WILL DROP SOUTH ACROSS
LAKE SUPERIOR LATE TONIGHT...SHIFTING THE WINDS TO A NORTHERLY
DIRECTION. WINDS MAY INCREASE TO AROUND 20 KNOTS LATE TONIGHT INTO
TUE MORNING BEHIND THE FRONT BUT SHOULD DIMINISH TUE AFTERNOON. A
HIGH PRESSURE RIDGE WILL THEN MOVE OVER LAKE SUPERIOR FOR TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT AND KEEP WINDS LIGHT.
AREAS OF FOG WILL CONTINUE TO AFFECT LAKE SUPERIOR TODAY INTO
TONIGHT AS WINDS REMAIN RELATIVELY LIGHT AND ABUNDANT LOW LEVEL
MOISTURE REMAINS OVER THE REGION. SO...THE DENSE FOG ADVY REMAINS IN
EFFECT THROUGH TONIGHT. AS DRIER AIR AND STRONGER MIXING ARRIVE
LATER TUESDAY INTO TUESDAY NIGHT BEHIND THE COLD FRONT...EXPECT THE
FOG TO DISSIPATE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 8 AM EDT TUESDAY FOR LSZ263-264-266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...07
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
508 AM EDT MON JUL 13 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 507 AM EDT MON JUL 13 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A BORAD MID/UPPER LEVEL RIDGE
CENTERED OVER THE SRN PLAINS AND A TROUGH OVER SRN MANITOBA. AT THE
SFC...A FRONTAL BOUNDARY FROM SE NORTH DAKOTA THROUGH SE MN INTO NRN
IL. THE STRONGEST CONVECTION WITH A LARGE MCS THAT DEVELOPED OVER MN
HAS SLIDE SE INTO CNTRL/SRN WI ALONG AND NORTH OF THE FRONT AND
MUCAPE GRADIENT. SHOWERS AND EMBEDDED TSRA ASSOCIATED WITH THE
LEFTOVER MCV PERSISTED INTO WRN LAKE SUPERIOR AND WRN UPPER MI.
TODAY...RADR TRENDS AND SHORT RANGE HIGH RES MODELS SUGGEST THAT THE
SHRA/TSRA OVER WRN UPPER MI WILL CONTINUE TO GRADUALLY SLIDE TO THE
EAST EARLY THIS MORNING WHILE ALSO WEAKENING AS THE PCPN MOVES AWAY
FROM THE AREA OF GREATER INSTABILITY. HOWEVER...THE APPROACH OF A
WEAK SHRTWV IN ADVANCE OF THE MANITOBA TROUGH MAY RESULT IN
ADDITIONAL DEVELOPMENT BY LATE MORNING INTO THE EARLY AFTERNOON AS
DAYTIME HEATING INCREASES AND A WEAK SFC TROUGH MOVES THROUGH THAT
COULD ALSO INTERACT WITH LAKE BREEZE BOUNDARIES. OVERALL CONFIDENCE
IN PCPN TIMING/COVERAGE IS LOW GIVEN MODEL DIFFERENCES AND LINGERING
EFFECTS OF THE LARGE MCS. WITH FCST MLCAPE VALUES ONLY INTO THE 500-
1000 J/KG RANGE AND WEAK 0-6KM/0-1KM SHEAR MAINLY JUST BRIEF HEAVY
RAIN WOULD BE THE MAIN HAZARD.
TONIGHT...EXPECT THE MID LEVEL TROUGH INTO THE NRN LAKES TO
GRADUALLY SINK OFF TO THE SE. WITH THE LOSS OF DAYTIME INSTABILITY
AND ANY WEAK MID LEVEL FORCING WITH THE TROUGH...SHRA/TSRA WILL
DIMINISH FROM THE NW OVERNIGHT. THERE MAY BE SOME SHOWERS LATE INTO
THE NORTH AS THE COLD FRONT SLIDES INTO THE AREA.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 301 PM EDT SUN JUL 12 2015
NAM SHOWS A TROUGH ON THE WEST COAST...A RIDGE OVER THE
ROCKIES...SHORTWAVE OVER THE UPPER GREAT LAKES 00Z TUE. A COLD FRONT
MOVES THROUGH THE AREA MON NIGHT INTO TUE AND THEN WENT DRY FOR TUE
NIGHT AND WED. OVERALL...DID NOT MAKE TOO MANY CHANGES TO THE GOING
FORECAST FOR TEMPERATURES OR WEATHER.
IN THE EXTENDED...GFS AND ECMWF SHOW A BROAD 500 MB TROUGH IN THE
WESTERN U.S. AND A RIDGE ACROSS THE GULF COAST 12Z THU. THERE IS
ALSO A SHORTWAVE OVER THE NORTHERN PLAINS 12Z THU THAT MOVES INTO
THE UPPER GREAT LAKES 12Z FRI. BEHIND THIS SHORTWAVE...UPPER RIDGING
MOVES INTO THE UPPER GREAT LAKES ON SAT INTO SUN WITH SOME WARMER
AIR TRYING TO GET INTO THE AREA THIS NEXT WEEKEND. SFC FRONTS WILL
BE IN THE AREA WITH THE AREA BEING ON THE BOUNDARY BETWEEN VERY WARM
AND HUMID AIR TO THE SOUTH AND COOLER AND DRIER AIR TO THE NORTH AND
HAVING SOME POPS IN FOR THE EXTENDED SEEMS WARRANTED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 124 AM EDT MON JUL 13 2015
SOME SHOWERS/EMBEDDED TS ON THE NRN FRINGE OF CONVECTIVE COMPLEX
MOVING THRU WI ARE LIKELY TO IMPACT IWD THE FIRST COUPLE HRS OF THE
FCST PERIOD...RESULTING IN SOME MVFR AND PERHAPS IFR CONDITIONS. THE
REMNANTS OF THESE SHOWERS MAY REACH CMX AND SAW AS WELL LATER...BUT
TS ARE NOT LIKELY ENUF AT THESE PLACES TO WARRANT A SPECIFIC MENTION
IN THE TAF. MVFR CONDITIONS ARE POSSIBLE AT THESE SITES AS WELL WITH
HUMID AIR AND NOCTURNAL COOLING...ESPECIALLY IF THE SHOWERS REACH
THESE AIRPORTS. MORE SHOWERS AND PERHAPS MVFR CONDITIONS MAY LINGER
THRU MUCH OF THE MRNG AS WELL ALONG WITH THE MVFR CONDITIONS. BUT IN
THE AFTN...DAYTIME HEATING IS LIKELY TO CAUSE A RETURN TO VFR WX.
THIS HEATING MAY ALSO CAUSE MORE SHOWERS AND PERHAPS A TS TO DEVELOP
AS WELL...ESPECIALLY AT IWD AND SAW AWAY FM LK SUP MODERATION. MVFR
CONDITIONS WL BE POSSIBLE AGAIN BY LATE EVNG WITH LINGERING LLVL
MSTR/NOCTURNAL COOLING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 351 PM EDT SUN JUL 12 2015
A WEAKENING RIDGE COMBINED WITH AN LOW PRESSURE SYSTEM MOVING FROM
SOUTHEAST SASKATCHEWAN THROUGH SOUTHERN WISCONSIN WILL KEEP WINDS
BELOW 20KTS THROUGH MONDAY EVENING. A COLD FRONT WILL DROP SOUTH
ACROSS LAKE SUPERIOR LATE MONDAY NIGHT...SHIFTING THE WINDS TO A
NORTHERLY DIRECTION...BUT SPEEDS WILL LARGELY STAY BELOW 20KTS. A
HIGH PRESSURE RIDGE WILL THEN MOVE OVER LAKE SUPERIOR FOR TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT AND KEEP WINDS LIGHT.
AREAS OF FOG CONTINUE TO AFFECT LAKE SUPERIOR TODAY AS WARM...MOIST
AIR IS FLOWING OVER THE RELATIVELY COOL OPEN WATERS OF LAKE
SUPERIOR. THIS MORNING THE FOG WAS CONFINED TO THE NORTHERN HALF
OF THE LAKE...BUT LIGHT NORTHEASTERLY FLOW HAS EDGED THAT FOG A
LITTLE FARTHER TO THE SOUTH. SEVERAL SHIP OBS TODAY INDICATED THE
FOG WAS DENSE AT TIMES...SO DECIDED TO ISSUE A MARINE DENSE FOG
ADVISORY FOR THE NORTHERN PORTIONS OF LAKE SUPERIOR INTO MONDAY
NIGHT. WITH THE CONTINUED WARM AND MOIST AIR...ALONG WITH
SOME RAIN TONIGHT INTO MONDAY...WILL CONTINUE TO SHOW AREAS OF FOG
THROUGH MONDAY NIGHT. THEN AS DRIER AIR ARRIVES LATER TUESDAY INTO
TUESDAY NIGHT BEHIND THE COLD FRONT...EXPECT THE FOG POTENTIAL TO
DIMINISH.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 8 AM EDT TUESDAY FOR LSZ263-264-266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...07
AVIATION...KC
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
125 AM EDT MON JUL 13 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 351 PM EDT SUN JUL 12 2015
THE UPPER RIDGE THAT HAS BEEN OVER THE UPPER GREAT LAKES REGION WILL
BREAK DOWN THROUGH THE SHORT TERM PERIOD...SETTING THE STAGE TO A
RETURN TO BELOW NORMAL TEMPERATURES FOR THE TUESDAY-THURSDAY TIME
FRAME. THIS BREAKDOWN WILL BE DRIVEN BY THE SEVERAL EMBEDDED WAVES
ASSOCIATED WITH THE UPPER TROUGH OVER SOUTHERN ALBERTA/SASKATCHEWAN
AND MONTANA. A BROAD 1000MB SURFACE LOW IS LOCATED BELOW THIS UPPER
LOW AND A TROUGH STRETCHES SOUTHEAST INTO THE EASTERN DAKOTAS. THESE
FEATURES WILL BE THE MAIN FOCUS FOR CONVECTION LATE THIS AFTERNOON
INTO MONDAY. TO THE EAST OF THOSE FEATURES AND OVER UPPER
MICHIGAN...A HIGH PRESSURE RIDGE HAS BEEN WEAKENING AND DEPARTING
THE AREA TO THE SOUTHEAST. SOUTHERLY FLOW AROUND THIS HIGH CONTINUES
TO LEAD TO THE WARM/HUMID CONDITIONS ACROSS THE U.P....WITH
AFTERNOON TEMPERATURES IN THE LOWER 80S AND DEWPOINTS IN THE UPPER
50S AND LOWER 60S. WITH SUNSHINE TO START THE DAY...DIURNAL HEATING
HAS PRODUCED A CU FIELD OVER THE INTERIOR WEST...WHILE THE LAKE
BREEZE OVER THE EAST OFF LAKE MICHIGAN (KISQ ONLY 72 AT 3PM) HAS
STABILIZED THAT AREA AND KEEP CONDITIONS MOSTLY SUNNY. THUNDERSTORMS
HAVE CONTINUED TO DEVELOP IN THE NORTHEAST EDGE OF THE 850MB WARM
AIR ADVECTION IN NORTHEAST MINNESOTA AND NORTHWEST WISCONSIN...WHICH
IS NOW PUSHING SHOWERS AND THUNDERSTORMS EAST ACROSS WESTERN LAKE
SUPERIOR. THE TREND HAS BEEN FOR THEM TO DIMINISH AS THEY PUSH EAST
INTO THE WEAKER MID LEVEL LAPSE RATES AND AWAY FROM THE BETTER
FORCING. EXPECT THAT TO ALSO OCCUR WITH THE STORMS IN WESTERN LAKE
SUPERIOR AND HAVE SEEN A DOWNWARD TREND ON RADAR AND LIGHTNING OVER
THE LAST 15-30MIN. HAVE SEEN A FEW BRIEF SHOWERS DEVELOP OVER
WESTERN/CENTRAL UPPER MICHIGAN THIS AFTERNOON...BUT OVERALL THEY
HAVE BEEN FAIRLY SMALL AND VERY ISOLATED. EXPECT THAT ISOLATED
POTENTIAL TO CONTINUE...INHIBITED BY THE WEAKER MID LEVEL LAPSE
RATES AND RAP SOUNDINGS SHOWING SOME CAPPING NEAR 725MB. IF
SOMETHING COULD GET GOING WOULD LARGELY EXPECT BRIEF HEAVY RAIN AND
SMALL HAIL DUE TO THE HIGH FREEZING LEVELS. ANY OF THESE SHOWERS
THAT DO DEVELOP SHOULD DIMINISH AS DIURNAL HEATING IS LOST.
THE FORECAST THEN TURNS TO WHAT WILL OCCUR UPSTREAM IN EASTERN NORTH
DAKOTA AND NORTHWEST MINNESOTA OVER THE NEXT FEW HOURS.
THUNDERSTORMS WILL QUICKLY DEVELOP IN THAT AREA THIS EVENING
(ALREADY STARTING TO SEE DEVELOPMENT SOUTH AND EAST OF FARGO ALONG
THE WARM FRONT) IN ASSOCIATION WITH A SHORTWAVE NOW MOVING THROUGH
CENTRAL NORTH DAKOTA. WHILE THEY WILL BE DISCRETE STORMS
INITIALLY...THE EXPECTATION IS FOR THEM TO DEVELOP SOUTHEAST INTO AN
MCS THROUGH THE NIGHT. AT THIS POINT...THE EXPECTED DEVELOPMENT
LOCATION AND STORM MOTION WOULD MOVE THE STORMS TO THE EAST ACROSS
THE NORTHERN/CENTRAL PORTIONS OF MINNESOTA AND THEN DIVE FARTHER TO
THE SOUTHEAST AS THEY NEAR WESTERN WISCONSIN DUE TO THE SOUTHEAST
POINTING FORWARD PROPAGATING CORFIDI VECTORS AND THE LOCATION OF THE
MUCAPE GRADIENT. WHILE THE STRONGEST STORMS SHOULD STAY TO THE SOUTH
OF THE CWA...STILL THINK THE AREA WILL SEE THE NORTHERN SIDE OF THE
COMPLEX...WHICH WILL PRODUCE SHOWERS AND THUNDERSTORMS (ESPECIALLY
NEAR THE WISCONSIN BORDER OUT WEST). WILL CONTINUE TO SHOW THE
HIGHEST POPS THERE DURING THE OVERNIGHT HOURS AND THEN DIMINISH THEM
AS THE MAIN COMPLEX SLIDES AWAY FROM THE AREA. WILL ADD A MENTION OF
STRONG STORMS PRODUCING GUSTY WINDS FOR THE NORTHERN EDGE OF THE MCS
BRUSHING THE WISCONSIN BORDER.
THE QUESTION THEN TURNS TO WHAT WILL HAPPEN TOMORROW BEHIND THE MCS
THAT MOVES TO THE SOUTH OF THE AREA. THERE STILL WILL BE UPPER LEVEL
SUPPORT FOR SHOWERS/THUNDERSTORMS AS THE UPPER TROUGH ENERGY MOVES
THROUGH THE REGION (ALONG WITH THE SURFACE TROUGH). WILL CONTINUE TO
SHOW CHANCE POPS...LIKELY TIED TO THE COMBINATION OF THE UPPER
TROUGH AND WHAT IS LEFT OVER FROM THE NORTHERN EDGE OF THE MCS. THE
POPS WILL NEED TO BE FINE TUNED TONIGHT ONCE THE MCS HAS SHOWN ITS
LOCATION/MOVEMENT...AS IT WILL LIKELY AFFECT THE LOCATION OF THE
PRECIPITATION TOMORROW. INSTABILITY WILL NOT BE AS STRONG AS
TODAY...MUCAPE VALUES GENERALLY STRUGGLING TO EVEN GET TO 750J/KG
(EXCEPT OVER FAR WESTERN UPPER MICHIGAN)...SO THINK THE THUNDER
CHANCES WILL BE LIMITED BUT STILL KEEP THE CHANCE THERE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 301 PM EDT SUN JUL 12 2015
NAM SHOWS A TROUGH ON THE WEST COAST...A RIDGE OVER THE
ROCKIES...SHORTWAVE OVER THE UPPER GREAT LAKES 00Z TUE. A COLD FRONT
MOVES THROUGH THE AREA MON NIGHT INTO TUE AND THEN WENT DRY FOR TUE
NIGHT AND WED. OVERALL...DID NOT MAKE TOO MANY CHANGES TO THE GOING
FORECAST FOR TEMPERATURES OR WEATHER.
IN THE EXTENDED...GFS AND ECMWF SHOW A BROAD 500 MB TROUGH IN THE
WESTERN U.S. AND A RIDGE ACROSS THE GULF COAST 12Z THU. THERE IS
ALSO A SHORTWAVE OVER THE NORTHERN PLAINS 12Z THU THAT MOVES INTO
THE UPPER GREAT LAKES 12Z FRI. BEHIND THIS SHORTWAVE...UPPER RIDGING
MOVES INTO THE UPPER GREAT LAKES ON SAT INTO SUN WITH SOME WARMER
AIR TRYING TO GET INTO THE AREA THIS NEXT WEEKEND. SFC FRONTS WILL
BE IN THE AREA WITH THE AREA BEING ON THE BOUNDARY BETWEEN VERY WARM
AND HUMID AIR TO THE SOUTH AND COOLER AND DRIER AIR TO THE NORTH AND
HAVING SOME POPS IN FOR THE EXTENDED SEEMS WARRANTED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 124 AM EDT MON JUL 13 2015
SOME SHOWERS/EMBEDDED TS ON THE NRN FRINGE OF CONVECTIVE COMPLEX
MOVING THRU WI ARE LIKELY TO IMPACT IWD THE FIRST COUPLE HRS OF THE
FCST PERIOD...RESULTING IN SOME MVFR AND PERHAPS IFR CONDITIONS. THE
REMNANTS OF THESE SHOWERS MAY REACH CMX AND SAW AS WELL LATER...BUT
TS ARE NOT LIKELY ENUF AT THESE PLACES TO WARRANT A SPECIFIC MENTION
IN THE TAF. MVFR CONDITIONS ARE POSSIBLE AT THESE SITES AS WELL WITH
HUMID AIR AND NOCTURNAL COOLING...ESPECIALLY IF THE SHOWERS REACH
THESE AIRPORTS. MORE SHOWERS AND PERHAPS MVFR CONDITIONS MAY LINGER
THRU MUCH OF THE MRNG AS WELL ALONG WITH THE MVFR CONDITIONS. BUT IN
THE AFTN...DAYTIME HEATING IS LIKELY TO CAUSE A RETURN TO VFR WX.
THIS HEATING MAY ALSO CAUSE MORE SHOWERS AND PERHAPS A TS TO DEVELOP
AS WELL...ESPECIALLY AT IWD AND SAW AWAY FM LK SUP MODERATION. MVFR
CONDITIONS WL BE POSSIBLE AGAIN BY LATE EVNG WITH LINGERING LLVL
MSTR/NOCTURNAL COOLING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 351 PM EDT SUN JUL 12 2015
A WEAKENING RIDGE COMBINED WITH AN LOW PRESSURE SYSTEM MOVING FROM
SOUTHEAST SASKATCHEWAN THROUGH SOUTHERN WISCONSIN WILL KEEP WINDS
BELOW 20KTS THROUGH MONDAY EVENING. A COLD FRONT WILL DROP SOUTH
ACROSS LAKE SUPERIOR LATE MONDAY NIGHT...SHIFTING THE WINDS TO A
NORTHERLY DIRECTION...BUT SPEEDS WILL LARGELY STAY BELOW 20KTS. A
HIGH PRESSURE RIDGE WILL THEN MOVE OVER LAKE SUPERIOR FOR TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT AND KEEP WINDS LIGHT.
AREAS OF FOG CONTINUE TO AFFECT LAKE SUPERIOR TODAY AS WARM...MOIST
AIR IS FLOWING OVER THE RELATIVELY COOL OPEN WATERS OF LAKE
SUPERIOR. THIS MORNING THE FOG WAS CONFINED TO THE NORTHERN HALF
OF THE LAKE...BUT LIGHT NORTHEASTERLY FLOW HAS EDGED THAT FOG A
LITTLE FARTHER TO THE SOUTH. SEVERAL SHIP OBS TODAY INDICATED THE
FOG WAS DENSE AT TIMES...SO DECIDED TO ISSUE A MARINE DENSE FOG
ADVISORY FOR THE NORTHERN PORTIONS OF LAKE SUPERIOR INTO MONDAY
NIGHT. WITH THE CONTINUED WARM AND MOIST AIR...ALONG WITH
SOME RAIN TONIGHT INTO MONDAY...WILL CONTINUE TO SHOW AREAS OF FOG
THROUGH MONDAY NIGHT. THEN AS DRIER AIR ARRIVES LATER TUESDAY INTO
TUESDAY NIGHT BEHIND THE COLD FRONT...EXPECT THE FOG POTENTIAL TO
DIMINISH.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 8 AM EDT TUESDAY FOR LSZ263-264-266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...07
AVIATION...KC
MARINE...SRF
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1239 AM CDT MON JUL 13 2015
.UPDATE...
ISSUED AT 1239 AM CDT MON JUL 13 2015
UPDATED FOR THE NEW 06Z AVIATION DISCUSSION BELOW.
UPDATE ISSUED AT 555 PM CDT SUN JUL 12 2015
UPDATED TO ADD TORNADO WATCH. LOW LEVEL SHEAR HAS BEEN INCREASING
IN THE WATCH AREA. HAVE BEEN WATCHING TORNADIC STORMS TO THE WEST
AND EXPECT THIS SYSTEM TO EVENTUALLY SPREAD INTO EACH AREA IN THE
NEXT HOUR OR SO AS DESTABILIZATION INCREASES. LOOKS LIKE EARLIER
CIN IS GONE...SO WILL SEE A RAPID INCREASE IN STORM STREGTH. GOOD-
LOOKING HODOGRAPH FOR BRAINERD SUGGEST STRONG POTENTIAL FOR
ROTATING STORMS WITH LARGE HAIL DAMAGING WINDS AND TORNADOES.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 333 PM CDT SUN JUL 12 2015
THE FORECAST AREA WAS BETWEEN DEPARTING HIGH PRESSURE OVER NORTHERN
LAKE SUPERIOR AND LOW PRESSURE MOVING THROUGH SE ND. A WARM FRONT
EXTENDED SEWD FROM THE LOW THROUGH WEST CENTRAL AND SW MN. THE LAST
REMNANTS OF THE MORNING THUNDERSTORMS WAS OVER THE TIP OF THE
ARROWHEAD AND SHOULD EXIT BY 21Z. NEW SHOWERS AND STORMS WERE
DEVELOPING IN WEST CENTRAL MN N OF THE WARM FRONT AND A COUPLE
COUNTIES W OF THE AREA. SOME OF THE CLOUDS HAVE DISSIPATED ALLOWING
FOR SOME WARMING AND AN INCREASE IN DEWPOINTS AS WELL AS AN INCREASE
IN INSTABILITY. EXPECT THUNDERSTORMS TO FORM ALONG AND N OF THE WARM
FRONT THROUGH THE REST OF THE AFTERNOON AND GRADUALLY SPREAD INTO
THE WESTERN PORTION OF THE REGION.
EXPECT SOME OF THE STORMS TO BECOME SEVERE TONIGHT AND PERCOLATE IN
THE VCNTY OF THE FORECAST AREA UNTIL 06Z. LATEST HRRR IS IN
AGREEMENT WITH THIS ASSESSMENT. SOME STORMS WILL STILL BE AROUND
THROUGH THE OVERNIGHT WITH HEAVY RAIN ACCOMPANYING SOME OF THE
STRONGER STORMS. HAVE SHOWN A GRADUAL DECREASE IN POPS AFTER 08Z
THROUGH 12Z AS HIGH PRESSURE BEGINS TO BUILD INTO THE AREA. EVEN
THOUGH SOME NICE RAIN WAS NOTED DURING THE DAY...NOT EXPECTING ANY
FLOODING ISSUES WITH THE STORMS TONIGHT.
ON MONDAY...THE SFC LOW MOVES ACROSS CENTRAL MN INTO NORTHERN WI.
SOME AREAS WILL GET A BREAK FROM THE STORMS IN THE MORNING BEFORE
REDEVELOPMENT BEGINS BY AFTERNOON. SOME OF THE STORMS MAY CONTAIN
BRIEF MODERATE DOWNPOURS. THE MAJORITY OF THE RAIN WILL FALL ALONG
AND N OF THE LOW TRACK WHERE AN UPPER LEVEL SHORT WAVE WILL TRACK
THROUGH THE AREA AS WELL.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 333 PM CDT SUN JUL 12 2015
ACTIVE WEATHER PATTERN STILL LOOKS LIKELY WITH CHANCES FOR SHOWERS
AND STORMS MOST DAYS THIS WEEK. TEMPERATURES WILL BRIEFLY COOL DOWN
TO MORE SEASONABLE TEMPS MID-WEEK...RETURNING TO THE UNSEASONABLY
WARM AND HUMID WEATHER BY THE WEEKEND.
ON THE SYNOPTIC SCALE THE INFLUENCE OF THE 500MB RIDGE/UPPER HIGH
OVER THE SOUTHERN PLAINS WILL GIVE WAY TO A SERIES OF MID-LEVEL
DISTURBANCES THAT WILL MOVE ACROSS THE NORTHERN TIER OF THE COUNTRY.
A DEEP LONGWAVE TROUGH OVER THE WEST COAST WILL BEGIN TO FLATTEN OUT
AND CAUSE A SERIES OF MID-LEVEL SHORTWAVES TO MOVE EAST OVER THE
RIDGE. ON MONDAY NIGHT INTO TUESDAY A DEPARTING SFC LOW WILL GIVE
WAY TO A COLD FRONT MOVING IN FROM THE NORTH ON LATE TUESDAY. THIS
FRONTAL PASSAGE WILL RESULT IN NORTH TO NORTHEASTERLY WINDS AT LOW
LEVELS AND THUS COOLER TEMPS. THE COMBINATION OF THE ORIGIN OF THIS
AIR /CANADA/ AND THE FACT THAT MOST OF IT IS MOVING OVER LAKE
SUPERIOR BEFORE REACHING LAND WILL RESULT IN MUCH COOLER AND DRIER
/LOWER DEW POINT/ AIR. HOWEVER...WITH A RIDGE AXIS ALOFT MOVING
ACROSS THE AREA EARLY WEDNESDAY SOUTHWESTERLY FLOW WILL RETURN
RESULTING IN RISING TEMPS AND DEW POINT VALUES.
LATE IN THE WEEK WE HAVE FAIRLY HIGH PRECIP CHANCES...THOUGH THE
EXACT DETAILS OF EACH DAY ARE STILL TOUGH TO PIN DOWN.
REGARDLESS...OVERALL PATTERN IS FAVORABLE FOR SHOWERS AND STORMS
EACH DAY. LATE IN THE WEEK INTO THE WEEKEND GUIDANCE IS DEPICTING
MUCH STRONGER WINDS ALOFT WITH A 120KT OR SO JET AT 250MB. THESE
STRONGER WINDS ALOFT COULD LEAD TO A BETTER ENVIRONMENT THUNDERSTORM
DEVELOPMENT...DEPENDING ON HOW MUCH INSTABILITY CAN DEVELOP. WILL
DEFINITELY BE SOMETHING TO WATCH AS IT HAS BEEN A WHILE SINCE WE
HAVE HAD STRONGER WINDS ALOFT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1239 AM CDT MON JUL 13 2015
A POTENT COMPLEX OF THUNDERSTORMS WAS CONTINUING TO MOVE THROUGH
MINNESOTA AND WISCONSIN EARLY THIS MORNING. THE STRONGEST STORMS
HAD EXITED NE MINNESOTA AND NW WISCONSIN BY THE TIME OF WRITING
THIS DISCUSSION. THE KHYR/KDLH/KHIB CAN EXPECT RAIN AND OCCASIONAL
LIGHTNING THROUGH THE WEE HOURS OF THIS MORNING.
FOG AND LOW STRATUS COULD FORM EARLY THIS MORNING...AND POSSIBLY
BRING PERIODS OF LIFR/IFR CONDITIONS. THE FOG SHOULD DISSIPATE BY
8 AM.
SCATTERED SHOWERS AND THUNDERSTORMS WILL LIKELY DEVELOP LATE THIS
AFTERNOON AND THIS EVENING. THE SHOWERS AND STORMS WILL BECOME
LESS WIDESPREAD LATER TONIGHT...BUT COULD CONTINUE OVERNIGHT AS A
COLD FRONT DROPS OUT OF CANADA AND MOVES THROUGH NE MINNESOTA AND
THEN NW WISCONSIN.
THE ASOS AT KBRD HAS BEEN MALFUNCTIONING SINCE POWERFUL
THUNDERSTORMS ROLLED THROUGH THE AREA THIS PAST EVENING...AND HAS
NOT BEEN RELIABLY REPORTING WIND/VISIBILITY/CEILING INFORMATION.
AMENDMENTS ARE NOT SCHEDULED UNTIL THE ASOS CAN BE REPAIRED.
TECHNICIANS WILL BE NOTIFIED LATER THIS MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 64 71 55 73 / 30 40 10 20
INL 62 78 56 79 / 30 40 30 20
BRD 64 82 59 83 / 40 50 10 20
HYR 63 76 56 79 / 30 30 10 20
ASX 60 69 53 75 / 30 40 10 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
UPDATE...GROCHOCINSKI
SHORT TERM...GSF
LONG TERM...JJM
AVIATION...GRANING/GROCHOCINSKI
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
544 PM CDT Mon Jul 13 2015
.SHORT TERM...(This Evening through Tuesday)
Issued at 215 PM CDT MON JUL 13 2015
High pressure remained in control of the Ozarks weather today with
most locations across the region seeing afternoon temperatures in
in the upper 80s to lower 90s. Heat index values along and north
of I-44 were in from 100 to 108.
The region will remain on the eastern edge of the upper level
ridge overnight tonight and again on Tuesday. This will allow
temperatures and heat index values to reach similar levels seen
today, though probably a degree or two cooler. Despite this
slightly cooler expectation, heat index values should still climb
into the 100 to 106 degree range across the current heat advisory
area. AS a result will extend the heat advisory through 00z
Tuesday.
Mesoscale models have also been hinting at the convection ongoing
across SE Nebraska and NE Kansas continuing through this evening
and overnight and sagging into central SW Missouri. The concern is
that the ongoing convection can get a small cold pool going and
ride south into the Ozarks along the eastern edge of the 700mb
ridge. The primary concern would be strong straight line winds
with very large available CAPE and weak shear. Have increased rain
chances as a result but did not go more than slight/chance pops
due to continued uncertainty if the cold pool will form. This
will be a short term concern going into this evening and
overnight.
The issues for tonight and Tuesday boil down to the continuation
of the heat advisory through early Tuesday evening and potential
convection this evening and overnight. Cloud cover from the
potential storms would then potentially impact temperatures
Tuesday and a lingering surface/low level boundary may allow for
moisture pooling across central Missouri, which may locally
enhance heat index values.
.LONG TERM...(Tuesday Night through Monday)
Issued at 215 PM CDT MON JUL 13 2015
Upper ridge over the southern and central plains to flatten into
zonal flow bringing marginal but still welcome relief from the
bout of heat. Of greater note will be the lowered dew points as
winds shift in response to Canadian high pressure descending into
the Great Lakes Wednesday.
Models depict some scattered TSRA along a developing warm front
late Wednesday into Thursday but confidence is modest on how
widespread this rainfall will be.
Chances for precipitation then look to be largely west and north
of the region into the weekend as the northern stream looks to
remain active.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday Evening)
Issued at 540 PM CDT MON JUL 13 2015
Strong to severe convection beginning to develop along boundary
north and northwest of the CWA. Very unstable atmosphere in area
where initiation is occuring. HRRR seems to be handling this
fairly well and with cold pool development would take storms to
the south and into the cwa this evening. Have main convection
remaining north and east of the forecast TAF points but with
boundary moving into the area overnight, did put some VCTS in for
SGF/JLN towards morning. Will have some low level wind shear
during the overnight hours.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...HEAT ADVISORY until 7 PM CDT Tuesday FOR MOZ055>058-066>071-
077>081-088>090-093-094-101.
KS...HEAT ADVISORY until 7 PM CDT Tuesday FOR KSZ073-097-101.
&&
$$
SHORT TERM...Hatch
LONG TERM...Runnels
AVIATION...Lindenberg
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
534 PM CDT MON JUL 13 2015
.SHORT TERM: (THROUGH LATE TONIGHT)
ISSUED AT 410 PM CDT MON JUL 13 2015
HEAT ADVISORY CONTINUES ACROSS THE ENTIRE AREA UNTIL LATER THIS
EVENING WITH SURFACE TEMPERATURES IN THE 90S AND DEW POINTS IN THE
70S THIS AFTERNOON. HEAT INDICES WERE MAINLY FROM 100 TO 110,
TOPPING OUT AT 113 AT LAMBERT FIELD. CONVECTION CONTINUES TO
DEVELOP ACROSS NORTHERN MO ON THE NORTHERN FRINGES OF THE CAP AND
AHEAD OF A COLD FRONT WHICH EXTENDS FROM NORTHWESTERN WI SOUTHWEST
INTO CENTRAL KS. CONVECTION WILL CONTINUE TO DEVELOP TONIGHT AS THE
FRONT SINKS SLOWLY SOUTHWARD INTO OUR AREA AND THE CAP GRADUALLY
WEAKENS. WITH EXTREME INSTABILITY AND AMPLE WIND SHEAR SOME OF THE
STORMS WILL BE SEVERE WITH DAMAGING WINDS BEING THE MOST LIKELY
HAZARD. MOST OF THE CONVECTION WILL BE ACROSS NORTHEAST MO AND WEST
CENTRAL IL THIS EVENING, THEN SHIFT SOUTHWARD INTO CENTRAL AND
SOUTHEAST MO AND SOUTHWEST ILLINOIS LATE TONIGHT. SLIGHTLY COOLER
CONDITIONS CAN BE EXPECTED ACROSS NORTHEAST MO LATE TONIGHT BEHIND
THE COLD FRONT, WITH CONTINUED WARM AND MUGGY CONDITIONS ELSEWHERE.
GKS
.LONG TERM: (TUESDAY THROUGH NEXT MONDAY)
ISSUED AT 410 PM CDT MON JUL 13 2015
UPPER LEVEL HIGH CENTERED OVER THE SOUTH-CENTRAL CONUS WILL MOVE
LITTLE OVER THE NEXT SEVEN DAYS...BUT ITS DOMINANCE OVER OUR REGION
WILL WAX AND WANE AT TIMES.
THIS UPPER LEVEL HIGH WILL LOSE SOME OF ITS INFLUENCE BEGINNING
TUESDAY AND THIS WILL BE ACCOMPANIED BY PASSAGE OF THE MAIN COLD
FRONT. HOWEVER...THIS COLD FRONTAL PASSAGE WILL COME TOO LITTLE TOO
LATE FOR MANY AREAS WITH W-SW WINDS EXPECTED THRU MUCH OF THE DAY
AND IN THE WAKE OF THE LEFTOVER CONVECTION FROM THE PRE-FRONTAL TROF
THE NIGHT BEFORE...MANY AREAS SHOULD SEE DECENT SUNSHINE RETURN.
MOS TEMPS SEEM TO HAVE A GOOD HANDLE ON THIS WITH A RETURN OF MID
90S TEMPS AND COUPLED WITH DEWPOINTS IN THE LOW-MID 70S WILL RESULT
IN HEAT INDICES BETWEEN 100-105 FOR A FOURTH CONSECUTIVE DAY FOR THE
CORRIDOR BETWEEN COU/JEF AND STL METRO. HAVE EXTENDED IN TIME THRU
EARLY TUESDAY EVENING THE HEAT ADVISORY FOR THIS AREA WITH POSSIBLE
AREAL EXPANSION ELSEWHERE ON TUESDAY. FOR NOW...THE HEAT ADVISORY
EXPIRES ELSEWHERE AT 9PM THIS EVENING.
COOLER TEMPS THEN TAKE HOLD FOR A COUPLE OF DAYS ON WEDNESDAY AND
THURSDAY PROVIDING SOME RELIEF AND KEEPING MAX TEMPS IN THE 80S FOR
MOST AREAS WITH LOWER HUMIDITIES.
THE HEAT AND HUMIDITY IS SET TO RETURN FOR FRIDAY AND THRU EARLY
NEXT WEEK WITH POSSIBLE RE-ISSUANCE OF HEAT HEADLINES.
OTHERWISE...RAIN CHANCES LOOK MEAGER FOR MUCH OF THIS PERIOD WITH
EITHER THE MAIN FOCUS TO OUR SOUTH IN THE CASE OF WEDNESDAY...AND A
WELL CAPPED ATMOSPHERE FOR FRIDAY THRU NEXT MONDAY. THE BEST
CHANCES WILL BE WEDNESDAY NIGHT AND THURSDAY WITH A WARM FRONT
BUCKLING BACK NORTH. DESPITE THE MAIN COLD FRONT MOVING THRU
TUESDAY AFTERNOON...THE PRE-FRONTAL TROF STEALS THE SHOW JUST ENOUGH
WITH MOISTURE TO ALLOW THE CAP TO LIKELY MAINTAIN THRU MUCH OF ITS
PASSAGE THRU THE FORECAST AREA.
TES
&&
.AVIATION: (FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 520 PM CDT MON JUL 13 2015
WEAK BOUNDARY, MORE OF A WIND SHIFT WITH A PRE-FRONTAL TROF, LIES
ACROSS NORTHERN MO. ONE BIG THUNDERSTORM AND SOEM SHOWERS ARE
MOVING EAST SOUTHEAST NEAR THIS BOUNDARY. SURFACE HEATING AND
ABUNDANT INSTABILITY LIKELY THE DRIVING FACTOR. HRRR BLOWS UP THE
LINE AND MOVE IT SOUTH. RAP AND THE LONGER TERM MODELS DO NOT,
KILLING IT AND THEN REDEVELOPING ABOUT 10Z ACROSS CENTRAL TO
EASTERN MO. THIS SCENARIO LOOKS BETTER GIVEN THE CAP AND CURRENT
TREND OF THE RAIN SHRINKING (EXCEPT FOR THE ONE STORM. BOUNDARY
WILL CONTINUE SOUTH WITH THE REAL COLD FRONT ARRIVING TUESDAY
AFTERNOON.
SPECIFICS FOR KSTL: NOT HIGH ON THE HRRR SOLUTION SO AM PRETTY MUCH
FOLLOWING THE NAM AND OTHER MODELS WHICH ARE IN BETTER AGREEMENT.
WILL WATCH THE CURRENT RAIN AND MAY NEED A VCSH/VCTS SOMETIME
THIS EVENING. OTHERWISE WILL PUT ANOTHER VCTS ABOUT 09-10Z BASED
ON THE NAM AND RAP. CAP SHOULD BE WEAKER BY THEN. WEST WIND
TUESDAY GOING NORTHWEST LATE IN THE AFTERNOON.
JPK
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...HEAT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR CRAWFORD MO-IRON
MO-KNOX MO-LEWIS MO-MADISON MO-MARION MO-MONROE MO-PIKE MO-
RALLS MO-REYNOLDS MO-SHELBY MO-ST. FRANCOIS MO-WASHINGTON
MO.
HEAT ADVISORY UNTIL 8 PM CDT TUESDAY FOR AUDRAIN MO-BOONE MO-
CALLAWAY MO-COLE MO-FRANKLIN MO-GASCONADE MO-JEFFERSON MO-
LINCOLN MO-MONITEAU MO-MONTGOMERY MO-OSAGE MO-ST. CHARLES
MO-ST. LOUIS CITY MO-ST. LOUIS MO-STE. GENEVIEVE MO-WARREN
MO.
IL...HEAT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR ADAMS IL-BOND IL-
BROWN IL-CLINTON IL-FAYETTE IL-GREENE IL-MACOUPIN IL-MARION
IL-MONTGOMERY IL-PIKE IL-WASHINGTON IL.
HEAT ADVISORY UNTIL 8 PM CDT TUESDAY FOR CALHOUN IL-JERSEY IL-
MADISON IL-MONROE IL-RANDOLPH IL-ST. CLAIR IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
352 AM CDT MON JUL 13 2015
.SHORT TERM: (TODAY AND TONIGHT)
ISSUED AT 330 AM CDT MON JUL 13 2015
THE MAIN FORECAST ISSUES REMAIN HEAT AND THUNDERSTORM POTENTIAL
AND THE CAVEATS DISCUSSED THE LAST FEW DAYS HAVEN`T CHANGED. ALL
INDICATIONS SUGGEST THAT TODAY WE WILL SEE THE HOTTEST DAY THUS
FAR THIS SUMMER. SOUTHWESTERLY LOWER TROP FLOW, CONTINUED LOW-MID
LEVEL WARMING, GOOD SUNSHINE, AND A WARM START ALL POINT TO HIGH
TEMPERATURES IN THE 90S WITH THE HOTEST READINGS IN THE UPPER 90S
IN METRO ST. LOUIS. AFTERNOON HEAT INDICES WILL BE IN DANGEROUS
LEVELS OF 105+ AND I HAVE EXPANDED THE HEAT ADVISORY TO INCLUDED
THE ENTIRE CWA.
WE CONTINUE TO WRESTLE WITH THUNDERSTORM CHANCES TODAY. ALL OF THE
DETERMINISTIC MODELS SHOW SIGNIFICANT MID LEVEL WARMING WITH H7
TEMPS AOA +12 DEGC BY LATE AFTERNOON. THE DETERMINISTIC MODELS
ALSO HAVE LITTLE IF ANY QPF AND WHERE THEY DO IS ON THE FRINGES OF
THE CWA. ALTERNATIVELY A NUMBER OF THE CONVECTION ALLOWING MODELS
BRING THE NORTHWEST FLOW CONVECTIVE COMPLEXES ACROSS ILLINOIS AND
THEN HAVE OUTFLOW GENERATED CONVECTION WELL INTO EASTERN MO THIS
AFTERNOON. MY BEST FEELING IS THAT THE WESTERN EDGE OF THE MCS
NOW CENTERED IN WISCONSIN OR ITS REMNANT BOUNDARY HAS POTENTIAL TO
BRING THUNDERSTORMS TO THE FAR EASTERN CWA/SOUTH CENTRAL IL WHERE
I HAVE CHANCE POPS - AND IF THESE DO IN FACT OCCUR THEY COULD BE
SEVERE. I HAVE ADDED SOME SLIGHT CHANCE POPS INTO THE FORECAST
FURTHER TO THE WEST INTO MO TO ACCOUNT FOR AT LEAST SOME UNCERTAINTY
AND ALSO TO MESH WITH MY WESTERN NWS NEIGHBORS, HOWEVER CONFIDENCE
IS QUITE LOW GIVEN THE CAP STRENGTH THIS AFTERNOON.
I THINK OUR BEST POTENTIAL TO SEE STORMS WILL BE THIS EVENING
AHEAD OF THE COLD FRONT THAT WILL BE PUSHING INTO THE AREA FROM
IOWA. HEIGHT FALLS/COOLING ALOFT ASSOCIATED WITH NORTHWEST FLOW
IMPULSES APPEAR TO BE SUFFICIENT TO WEAKEN THE CAP AND ALLOW
SCATTERED THUNDERSTORMS TO DEVELOP ACROSS NORTHERN MO THIS
EVENING, TRACKING SOUTHEAST AND ALSO MOVING SOUTHWARD WITH THE
BOUNDARY. GIVEN THE AMOUNT OF INSTABILITY AND RATHER STRONG DEEP
LAYER SHEAR THE POTENTIAL EXISTS FOR ORGANIZED SEVERE STORMS, BUT
THIS IS CONDITIONAL THAT STORMS DO IN FACT DEVELOP.
GLASS
.LONG TERM: (TUESDAY THROUGH SUNDAY)
ISSUED AT 330 AM CDT MON JUL 13 2015
THE INITIAL COLD FRONT/BOUNDARY WILL PUSH THROUGH THE AREA ON
TUESDAY WITH THE MAIN IMPACT BEING ADVECTION OF LOWER DEW POINTS.
TEMPERATURES WILL REMAIN SEASONABLY HOT GIVEN THE WEST/NORTHWEST
FLOW AND LACK OF COOLING. GIVEN THE DRIER AIR IT APPEARS THAT HEAT
INDICES WILL REMAIN BELOW ADVISORY CRITERIA ALTHOUGH THE STL METRO
WILL NEED TO BE WATCHED CLOSELY. A SECOND AND BETTER DEFINED COLD
FRONT WITH COOLER AIR AND ACCOMPANYING HIGH PRESSURE WILL MOVE
INTO AND THROUGH THE AREA TUESDAY NIGHT INTO WEDNESDAY. THIS FRONT
SHOULD AT LEAST PUT THE HOT TEMPERATURES IN CHECK FOR A DAY OR
TWO. HOWEVER THE FRONT RETREATS BACK NORTHWARD WEDNESDAY NIGHT
INTO THURSDAY WITH AN ACCOMPANYING CHANCE OF SHOWERS AND
THUNDERSTORMS, WHILE ALSO ALLOWING HEAT AND HUMIDITY TO RETURN FOR
LATE WEEK. THE HEAT APPEARS TO BUILD INTO THE WEEKEND AS THE UPPER
HIGH/RIDGE CENTERED TO OUR SOUTH THEN AMPLIFIES INTO THE UPPER MS
VALLEY.
GLASS
&&
.AVIATION: (FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1059 PM CDT SUN JUL 12 2015
ONLY QUESTION TONIGHT IS WHETHER PRECIPITATION WILL MAKE IT INTO
THE AREA OVERNIGHT. MOST MODELS, EXCEPT FOR THE GFS AND
OPERATIONAL HRRR, MOVE CURRENT COMPLEX(S) OVER THE UPPER MIDWEST
TO THE EAST. EXPERIMENTAL HRRR (WHICH LOADS ACTUAL RADAR DATA
FIRST) LOOKS GOOD WITH THE CURRENT COMPLEX AND ALSO KEEPS THE
MOVEMENT TO THE EAST. MAJORITY RULES SO WILL KEEP TAFS DRY. VFR
WITH SOUTH TO SOUTHWEST WIND.
SPECIFICS FOR KSTL: VFR WITH SOUTH TO SOUTHWEST WIND.
JPK
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...HEAT ADVISORY FROM NOON TODAY TO 8 PM CDT THIS EVENING FOR
AUDRAIN MO-BOONE MO-CALLAWAY MO-COLE MO-CRAWFORD MO-
FRANKLIN MO-GASCONADE MO-IRON MO-JEFFERSON MO-KNOX MO-LEWIS
MO-LINCOLN MO-MADISON MO-MARION MO-MONITEAU MO-MONROE MO-
MONTGOMERY MO-OSAGE MO-PIKE MO-RALLS MO-REYNOLDS MO-SHELBY
MO-ST. FRANCOIS MO-STE. GENEVIEVE MO-WARREN MO-WASHINGTON
MO.
HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR ST. CHARLES MO-ST.
LOUIS CITY MO-ST. LOUIS MO.
IL...HEAT ADVISORY FROM NOON TODAY TO 8 PM CDT THIS EVENING FOR ADAMS
IL-BOND IL-BROWN IL-CALHOUN IL-CLINTON IL-FAYETTE IL-GREENE
IL-JERSEY IL-MACOUPIN IL-MARION IL-MONROE IL-MONTGOMERY IL-
PIKE IL-RANDOLPH IL-WASHINGTON IL.
HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR MADISON IL-ST.
CLAIR IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1105 PM CDT SUN JUL 12 2015
.SHORT TERM: (THROUGH LATE TONIGHT)
ISSUED AT 345 PM CDT SUN JUL 12 2015
JUST A SCATTERED DIURNAL CUMULUS FIELD ACROSS OUR AREA THIS
AFTERNOON WITH BETTER COVERAGE ACROSS THE OZARKS OF SOUTHEAST MO.
COULD NOT RULE OUT AN ISOLATED LATE AFTERNOON SHOWER/STORM IN THIS
AREA, BUT IT APPEARS THAT IT WILL BE DRY FOR THE REMAINDER OF THE
AFTERNOON INTO THE EVENING. HEAT ADVISORY CONTINUES IN EFFECT FOR
THE ST LOUIS METRO AREA WITH CURRENT HEAT INDICES AROUND 102-103
ACROSS THIS AREA THIS AFTERNOON. IT WILL BE A WARM MUGGY NIGHT
WITH SURFACE DEW POINTS IN THE 70S. CONVECTION IS EXPECTED TO
DEVELOP ACROSS THE UPPER MIDWEST AND DROP SOUTH SOUTHEASTWARD
THROUGH IL LATER TONIGHT. THERE IS SOME UNCERTAINTY WITH THE
WESTWARD EXTENT OF THIS CONVECTION AS WARMER MID LEVEL
TEMPERATURES, CAPPING SPREAD EASTWARD TONIGHT. THE GFS MODEL LOOKS
TOO FAR WEST WITH ITS QPF TONIGHT, WHILE THE NAM MODEL MAY BE TOO
FAR EAST WITH ITS QFF. DUE TO THIS UNCERTAINTY WILL JUST INCLUDE
CHANCE POPS MAINLY LATE TONIGHT ACROSS NORTHEAST MO AND WEST
CENTRAL AND SOUTHWEST IL, NORTH AND EAST OF STL. ALTHOUGH THE
CONVECTION SHOULD IN THE WEAKENING STAGES AS IT DROPS SOUTH
SOUTHEASTWARD INTO THE NORTHEASTERN PORTION OF OUR FORECAST AREA,
IT MAY STILL BE CAPABLE OF PRODUCING STRONG WIND GUSTS ACROSS
NORTHEAST MO AND WEST CENTRAL IL LATE TONIGHT.
GKS
.LONG TERM: (MONDAY THROUGH NEXT SUNDAY)
ISSUED AT 345 PM CDT SUN JUL 12 2015
UPPER LEVEL HIGH CENTERED OVER THE SOUTH-CENTRAL CONUS WILL MOVE
LITTLE OVER THE NEXT SEVEN DAYS...BUT ITS DOMINANCE OVER OUR
REGION WILL WAX AND WANE AT TIMES. THE MODELS HAVE REMAINED
CONSISTENT IN SHOWING THE DOMINANCE OF THIS UPPER HIGH FADING LATE
MONDAY...AND ROUGHLY CORRESPONDING WITH A SURFACE COLD FRONT
DROPPING THRU MONDAY NIGHT. THE UPPER HIGH`S INFLUENCE IS THEN
EXPECTED TO EXPAND HEADING INTO THURSDAY AND THE WEEKEND AND THIS
ROUGHLY CORRESPONDS TO A SURFACE WARM FRONT PUSHING BACK THRU ON
THURSDAY.
WHEN THE FRONT IS TO OUR NORTH...NAMELY THRU MONDAY AND AGAIN
HEADING INTO LATE THIS WEEK AND NEXT WEEKEND...DANGEROUS LEVELS OF
HEAT AND HUMIDITY WILL BE A REAL CONCERN AND FOR THE ONGOING
SITUATION...A HEAT ADVISORY HAS ALREADY BEEN ISSUED AND WILL COVER
MUCH OF OUR REGION BY MONDAY. THIS HANDLES WELL THE CURRENT
FORECAST AND NO CHANGES WILL BE MADE. THE POTENTIAL HEAT AND
HUMIDITY EVENT FOR LATE WEEK IS TOO FAR OUT TO DEAL WITH HEADLINES
AT THE MOMENT BUT MERITS A CLOSE WATCH.
DESPITE A COLD FRONT EXPECTED TO MOVE THRU MONDAY NIGHT AND THE
FRONT SETTLING TO OUR SOUTH THRU WEDNESDAY...THERE WILL NOT BE A
SIGNIFICANT COOLDOWN ON TEMPS BUT PERHAPS ENOUGH OF ONE TO PLACE A
HOLD ON ANY HEAT HEADLINES. MAX TEMPS ON TUESDAY ARE STILL EXPECTED
TO BE IN THE LOW-MID 90S...BUT CONFIDENCE IN THESE TEMPS IS LOWER
THAN MONDAY DUE TO LEFTOVER CLOUDS FROM FRONTAL PASSAGE AND PCPN
CHANCES FOR SOME AREAS. THE ANTICIPATED DROP IN HUMIDITY FROM
MONDAY WILL MAKE ANY TEMPORAL EXTENSION OF A HEAT ADVISORY ENOUGH IN
DOUBT TO NOT TOUCH HEADLINES WITH THIS PACKAGE AND LET SUBSEQUENT
SHIFTS TAKE ANOTHER LOOK.
PCPN CHANCES FOR MONDAY SHOULD BE CONFINED MAINLY TO SOME SECTIONS
OF SOUTHWEST IL...WHICH WILL BE ON THE EDGE OF WHAT SHOULD BE A
SIGNIFICANT SEVERE WX EVENT FURTHER TO THE EAST...AND SOME AREAS OF
WEST-CENTRAL ILLINOIS AND NORTHEAST MISSOURI LATE MONDAY AFTERNOON
WITH WHAT SHOULD BEGIN TO DEVELOP ALONG AN APPROACHING COLD FRONT.
THIS COLD FRONT IS THEN EXPECTED TO DROP THRU THE AREA MONDAY NIGHT
WITH SMALL CHANCES FOR STORMS. THE ATMOSPHERE SHOULD INITIALLY BE
WELL CAPPED BUT THIS CAP WILL ERODE ENOUGH ON APPROACH OF THE FRONT
WHERE IT SHOULD RESULT IN SCATTERED CONVECTION. FRONT IS THEN
EXPECTED TO BE TO OUR SOUTH TUESDAY AND MUCH OF WEDNESDAY BEFORE
RIDING BACK NORTH THRU OUR AREA AS A WARM FRONT WITH ADDITIONAL
CHANCES FOR STORMS.
TES
&&
.AVIATION: (FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1059 PM CDT SUN JUL 12 2015
ONLY QUESTION TONIGHT IS WHETHER PRECIPITATION WILL MAKE IT INTO
THE AREA OVERNIGHT. MOST MODELS, EXCEPT FOR THE GFS AND
OPERATIONAL HRRR, MOVE CURRENT COMPLEX(S) OVER THE UPPER MIDWEST
TO THE EAST. EXPERIMENTAL HRRR (WHICH LOADS ACTUAL RADAR DATA
FIRST) LOOKS GOOD WITH THE CURRENT COMPLEX AND ALSO KEEPS THE
MOVEMENT TO THE EAST. MAJORITY RULES SO WILL KEEP TAFS DRY. VFR
WITH SOUTH TO SOUTHWEST WIND.
SPECIFICS FOR KSTL: VFR WITH SOUTH TO SOUTHWEST WIND.
JPK
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...HEAT ADVISORY FROM NOON TO 8 PM CDT MONDAY FOR AUDRAIN MO-BOONE
MO-CALLAWAY MO-COLE MO-CRAWFORD MO-FRANKLIN MO-GASCONADE MO-
JEFFERSON MO-KNOX MO-LEWIS MO-LINCOLN MO-MARION MO-MONITEAU
MO-MONROE MO-MONTGOMERY MO-OSAGE MO-PIKE MO-RALLS MO-SHELBY
MO-ST. FRANCOIS MO-STE. GENEVIEVE MO-WARREN MO-WASHINGTON
MO.
HEAT ADVISORY UNTIL 8 PM CDT MONDAY FOR ST. CHARLES MO-ST. LOUIS
CITY MO-ST. LOUIS MO.
IL...HEAT ADVISORY FROM NOON TO 8 PM CDT MONDAY FOR ADAMS IL-BOND IL-
BROWN IL-CALHOUN IL-CLINTON IL-FAYETTE IL-GREENE IL-JERSEY
IL-MACOUPIN IL-MARION IL-MONROE IL-MONTGOMERY IL-PIKE IL-
RANDOLPH IL-WASHINGTON IL.
HEAT ADVISORY UNTIL 8 PM CDT MONDAY FOR MADISON IL-ST. CLAIR IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
927 AM MDT MON JUL 13 2015
.UPDATE...
MADE ONLY A FEW ADJUSTMENTS TO THE INHERITED FORECAST. RADAR
SHOWED SOME CONVECTION OVER S ID STRETCHING INTO NW WY. THIS
CONVECTION WAS OCCURRING UNDER STREAMWISE VORTICITY IN THE SW FLOW
ALOFT ON THE WESTERN SIDE OF THE UPPER RIDGE OVER THE FORECAST
AREA. THE FLOW WILL BECOME SW OVER THE AREA THROUGH THIS EVENING
AND WILL CONTINUE ON TUE. THIS WILL ALLOW WEAK ENERGY TO MOVE
ACROSS THE AREA. INSTABILITY WILL BE BETWEEN 500-1000 J/KG THIS
AFTERNOON THROUGH 03Z THIS EVENING BASED ON THE SREF...ALTHOUGH
THE RAP WAS NOT AS UNSTABLE. SHEAR WILL BE LIMITED. MODELS LIMITED
THE CONVECTION TO OVER AND NEAR THE TERRAIN TODAY WHICH LOOKED
REASONABLE.
GOOD MIXING TO 700-600 MB WILL RESULT IN INVERTED-V SOUNDINGS.
WINDS WERE STILL 20 TO 30 KT AT 700 MB THIS AFTERNOON OVER THE
EASTERN ZONES WHICH WILL RESULT IN 15 TO 25 MPH MIXDOWN WINDS
THERE. BASED ON THE RAP DEWPOINTS THIS AFTERNOON...HAVE TRENDED
FORECAST DEWPOINTS A FEW DEGREES LOWER...RESULTING IN RH/S IN THE
TEENS OVER THE E ZONES. TEMPERATURES IN THE 80S TO LOWER 90S WERE
IN GOOD SHAPE. ADJUSTED SKY COVER TO COINCIDE CLOSER TO THE
OBSERVED VISIBLE SATELLITE THROUGH 18Z.
MODELS KEPT CHANCES FOR CONVECTION GOING THROUGH THE NIGHT WHICH
WAS IN LINE WITH THE PREVIOUS FORECAST. CHANCES FOR CONVECTION
WILL CONTINUE ON TUE. THE SREF SHOWED THE POTENTIAL FOR HIGHER
CAPES ACROSS THE AREA ON TUE WITH LOW SHEAR...SO WILL NEED TO
WATCH FOR SOME POSSIBLE STRONG STORMS ON TUE. ARTHUR
&&
.SHORT TERM...VALID FOR TDY AND TUE...
TODAY WILL BE DOMINATED BY SHORT WAVE RIDGING. WINDS WILL AGAIN BE
OUT OF THE WEST. THIS DOWNSLOPE FLOW COMBINED WITH THE SUBSIDENCE
FROM THE RIDGE SHOULD SUPPRESS RAIN CHANCES. HAVING SAID
THAT...SOME MID LEVEL MOISTURE IS STILL PRESENT ACROSS THE AREA
AND OVER THE MOUNTAINS SOME SHOWERS AND THUNDERSTORMS ARE
POSSIBLE.
HIGHS WILL AGAIN BE RISING INTO THE UPPER 80S TO LOWER 90S THIS
AFTERNOON. THESE WARM TEMPERATURES WILL HELP TO DEEPLY MIX THE
ATMOSPHERE. THIS WILL HELP TO INCREASE WINDS THIS
AFTERNOON...CREATING WINDS SIMILAR TO YESTERDAY. WIND GUSTS UP TO
35 MPH ARE POSSIBLE THIS AFTERNOON.
OVERNIGHT WHILE MUCH OF THE AREA WILL REMAIN DRY...A WEAK PULSE
OF ENERGY WILL MOVE ACROSS WESTERN MONTANA ALONG WITH SOME JET
DIVERGENCE. THIS WILL AT LEAST KEEP SOME RAIN CHANCES IN THE
MOUNTAINS AND SOME MAY DRIFT OFF ONTO THE ADJACENT PLANES.
FOR TUESDAY...THE RIDGE WILL SHIFT TO THE EAST WHICH WILL PUT THE
AREA IN SOUTHWEST FLOW. CAPE VALUES WILL BE GETTING INTO THE 500
TO 1500 J/KG RANGE WITH SOME DECENT SHEAR. THE SETUP DOES NOT LOOK
LIKE WIDESPREAD SEVERE WEATHER...BUT A FEW THUNDERSTORMS COULD BE
STRONG TO SEVERE. REIMER
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
MODELS CONTINUE TO SHOW BASIC BROAD PATTERN SIMILARITIES THROUGH
MOST OF THE EXTENDED PERIOD...BUT VARY IN THE TIMING OF SHORT
WAVES WITHIN THE FLOW. WE USED A BLEND OF SOLUTIONS FOR THE MOST
PART AS TIMING SHORT WAVES THIS FAR OUT IS OFTEN FUTILE...BUT DID
LEAN TOWARD CLIMATOLOGY FOR TIMING.
MODELS DO TEND TO AGREE ON THE MOST ACTIVE THUNDERSTORM DAYS
BEING WEDNESDAY AND FRIDAY EVENING. THERE IS POTENTIALLY A DECENT
COOLING TREND TOWARD THE WEEKEND AS A TROUGH DROPS INTO THE
NORTHWEST AND NORTHERN ROCKIES...BUT THE GFS AND ECMWF HANDLE THIS
FEATURE DIFFERENTLY WITH THE GFS DROPPING THE UPPER LOW DOWN THE
WEST COAST AND THE ECMWF TAKING THE TROUGH AXIS ACROSS US.
AGAIN...WE LEANED ON BLENDS AS 500MB ENSEMBLE SPREADS WERE RATHER
WIDE UPSTREAM OF OUR REGION OUT ALONG THE NORTHWEST COAST. BT
&&
.AVIATION...
MOSTLY CLEAR CONDITIONS CAN BE EXPECTED OVER AREAS EAST OF KBIL
THROUGH 21Z. ISOLATED SHOWERS/THUNDERSTORMS ARE POSSIBLE OVER THE
WESTERN TERRAIN MAINLY AFTER 20Z. MOUNTAIN OBSCURATIONS WILL BE
POSSIBLE IN THESE SHOWERS/TSRA. ANY SHOWERS/STORMS THAT FORM WILL
BE MOVING EASTWARDS AND WE COULD SEE VCSH/VCTS IN BIL/SHR...MAINLY
FROM 00-06Z. CS/WD
&&
.PRELIMINARY POINT TEMP/POPS...
TDY TUE WED THU FRI SAT SUN
-------------------------------------------------------
BIL 090 061/087 060/086 060/089 060/084 056/078 057/082
1/B 33/T 33/T 30/B 22/T 43/T 32/T
LVM 087 053/082 053/082 052/084 053/080 051/077 050/081
2/T 34/T 34/T 32/T 23/T 43/T 42/T
HDN 092 059/091 057/087 058/090 059/085 056/081 056/085
1/B 23/T 34/T 30/B 22/T 33/T 22/T
MLS 092 062/092 062/091 062/091 062/087 059/084 059/085
0/U 12/T 32/T 40/B 22/T 53/T 22/T
4BQ 091 061/092 062/090 060/090 061/089 058/084 059/084
0/U 13/T 33/T 40/B 22/T 22/T 22/T
BHK 089 059/089 061/089 059/088 059/086 057/084 058/082
0/N 02/T 34/T 41/B 22/T 42/T 22/T
SHR 088 055/087 055/085 055/086 056/086 054/080 054/082
2/T 24/T 33/T 21/B 22/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
654 PM CDT TUE JUL 14 2015
.SHORT TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 239 PM CDT TUE JUL 14 2015
TWO ROUNDS OF THUNDERSTORMS ARE ANTICIPATED IN THE SHORT TERM WITH
THE FIRST ROUND ADVANCING NORTHEAST INTO THE CWA FROM NORTH
CENTRAL KANSAS/SOUTH CENTRAL NEBRASKA OVERNIGHT INTO THE EARLY
MORNING HOURS WEDNESDAY AND THE SECOND ROUND DEVELOPING WEDNESDAY
AFTERNOON.
LATEST WATER VAPOR IMAGERY AND RAP 500 MB ANALYSIS SHOW AN UPPER
LEVEL RIDGE AXIS EXTENDING FROM THE SOUTH CENTRAL CONUS THROUGH
SOUTH CENTRAL CANADA. MONSOONAL FLOW CONTINUES TO MOVE THROUGH THE
INTERMOUNTAIN WEST WITH TWO DISTINCT SHORTWAVE TROUGHS THAT WILL
SOON IMPACT THE REGION. THE FIRST SHORTWAVE IS CURRENTLY LOCATED
OVER SOUTHEAST COLORADO WITH THE SECOND CURRENTLY OVER
SOUTHWESTERN NEW MEXICO.
AHEAD OF THIS...A FEW ISOLATED THUNDERSTORMS HAVE DEVELOPED NEAR
THE RIDGE AXIS IN CENTRAL NEBRASKA THIS AFTERNOON. A FEW OF THE
CAM`S BRING THIS ACTIVITY INTO OUR FAR WESTERN COUNTIES LATER THIS
EVENING BUT GENERAL FEELING IS THAT THEY WILL WEAKEN AS THEY
CONTINUE EAST AND HAVE LITTLE IMPACT ON THE CWA.
TSTMS ARE EXPECTED TO DEVELOP LATER ACROSS NORTH CENTRAL KANSAS
OVERNIGHT IN ADVANCE OF ABOVE MENTIONED SHORTWAVE IN STRONG WAA
REGIME AIDED BY NOSE OF NOCTURNAL LOW LEVEL JET. THIS ACTIVITY
WILL SPREAD NORTHEAST THROUGH THE MORNING AND LIKELY EXIT THE AREA
BY NOON. SOME OF THESE STORMS COULD BE SEVERE...BUT WILL BE
ELEVATED.
A DEVELOPING SURFACE LOW OVER WESTERN KANSAS AND ASSOCIATED
NORTHEASTWARD EXTENDING WARM FRONT WILL PUSH INTO SOUTHERN
NEBRASKA BY PEAK HEATING WEDNESDAY. IN ADDITION...THE SECOND ABOVE
MENTIONED PIECE OF SHORTWAVE ENERGY WILL MOVE TOWARD CENTRAL
NEBRASKA. DEPENDING ON SPEED OF EXITING MORNING TSTMS...THE
ATMOSPHERE SHOULD BE ABLE TO RECOVER LEADING TO MODERATE TO STRONG
INSTABILITY OVER THE FORECAST AREA BY PEAK HEATING. STRONG BULK
LAYER SHEAR VALUES WOULD INDICATE POTENTIAL FOR SUPERCELLS
INITIALLY...WITH A TORNADIC THREAT ALONG AND AHEAD OF THE WARM
FRONT. IN ADDITION TO SEVERE WEATHER...HEAVY RAIN IS ALSO POSSIBLE
WITH THE MORNING CONVECTION AND THE AFTERNOON/EVENING CONVECTION
WITH PW`S AOA 2.00". MUCH OF THE CWA IS OUTLOOKED IN THE SLIGHT
CATEGORY FOR EXCESSIVE RAINFALL AND FEEL THIS IS QUITE REASONABLE
GIVEN AMOUNT OF AVAILABLE MOISTURE. SOUTHWESTERLY NOCTURNAL LOW
LEVEL JET SHOULD SUSTAIN TSTM ACTIVITY AS IT PROGRESSES NORTHEAST
THROUGH THE CWA...ENDING IT THURSDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 239 PM CDT TUE JUL 14 2015
MODEST WESTERLY/SOUTHWESTERLY FLOW ALOFT WILL PERSIST INTO THE
WEEKEND. VERY HARD TO PIN DOWN EXACT TIMING OF THESE WAVES IN THE
LONG TERM...BUT CANNOT REALLY RULE OUT TSTMS IN ANY PARTICULAR PERIOD
WITH THIS TYPE OF PATTERN. WILL CARRY A LOW CONFIDENCE SMALL POP
THROUGH MUCH OF THE PERIOD. TEMPERATURES OVERALL LOOK SEASONAL.
&&
.AVIATION...(00Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 643 PM CDT TUE JUL 14 2015
SFC LOW PRES IS EXPECTED TO ORGANIZE OVER WRN KS BY 12Z WED
MORNING WITH ATTENDANT WARM FRONT EXTENDING EWD THRU KS. AREAL
COVERAGE OF TSRA WILL INCREASE THRU WED MORNING AS THE SFC BNDRY
LIFTS INTO ERN NEB. FOR NOW...WILL CONTINUE PROB30 GROUPS WITH
THIS ISSUANCE UNTIL DETAILS BECOME A BIT MORE REFINED.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...KERN
LONG TERM...KERN
AVIATION...DEE
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1226 PM CDT MON JUL 13 2015
.UPDATE...
ISSUED AT 1222 PM CDT MON JUL 13 2015
CONVECTION CONTINUES TO FIRE ACROSS SOUTHEAST NEBRASKA...ALONG THE
WIND SHIFT/PRESSURE CONVERGENCE LINE. ISOLATED SHOWERS WERE ALSO
NOTED ACROSS SOUTHWEST IOWA. OTHERWISE...DRIER AIR IS MOVING INTO
THE REGION WITH DEWPOINTS NOW DOWN INTO THE MID TO UPPER 60S
ALONG/NORTH OF I80. MID TO UPPER 70S DEWPOINTS PERSIST ACROSS
SOUTHEAST NEBRASKA AND SOUTHWEST IOWA. WILL LEAVE ONGOING HEAT
ADVISORY IN PLACE FOR NOW...BUT THE NORTHERN FRINGE ALONG I80 MAY
NOT REMAIN IN CRITERIA VERY LONG IF DEWPOINTS DROP JUST A BIT MORE.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 310 AM CDT MON JUL 13 2015
HEAT AND HUMIDITY TODAY...ISOLATED STORMS INTO MID MORNING AND
THEN SLIGHT CHANCE OF TSTMS LATE TODAY INTO THIS EVENING ARE THE
PRIMARY FORECAST CONCERNS THROUGH THIS PERIOD.
UPPER AIR CHARTS FROM LAST EVENING SHOWED THE FOLLOWING. AT 300 MB
A JET STREAK OF 80-90 KNOTS EXTENDED FROM ERN WY ACROSS SRN SD. AT
500 MB...WEAK HEIGHT FALLS WERE MOVING EWD ACROSS THE DAKOTAS AND
MN AND RIDGE ALOFT WAS STILL CENTERED OVER TX. THERMAL RIDGE AT
700 MB STRETCHED FROM NM INTO CO AND KS. ACROSS NEBRASKA...700 MB
TEMPERATURES WERE GENERALLY 12-13 DEGREES C. THERMAL RIDGE AT 850
MB WAS LOCATED FROM NM INTO WRN SD. DRIER AIR WAS OVER THE HIGH
PLAINS BUT 850 MB DEWPOINTS WERE IN THE TEENS FROM IA BACK INTO
ERN NE. THE KOAX SOUNDING FROM 00Z WAS FAIRLY MOIST...WITH A
PRECIPITABLE WATER OF 1.48 INCHES. SURFACE ANALYSIS AT 08Z SHOWED
A TROUGH OF LOW PRESSURE CURVING FROM THE ERN SD INTO NWRN KS.
AHEAD OF THIS TROUGH...DEWPOINTS WERE MOSTLY IN THE 70S BUT DROP
TO 60S AND 50S WEST OF THE TROUGH.
JUST HOW FAST DRIER AIR WILL BE ABLE TO MOVE IN TODAY WILL HAVE A
BIG IMPACT ON HEAT INDICES. LEFT PREVIOUSLY ISSUED HEAT ADVISORY
AS IS...BUT MAY NEED A SLIGHT ADJUSTMENT LATER TODAY. OTHERWISE...
ISOLATED TSRA WERE OCCURRING OVER PARTS OF NERN NE. THESE WERE
VERY HIGH BASED...ABOVE THE MID LEVEL CAP AND POSSIBLY GETTING
SOME SUPPORT BY THE JET STREAK MENTIONED EARLIER AND VERY WEAK
MID LEVEL HEIGHT FALLS. THESE MAY LAST INTO MID MORNING AS THEY
CONTINUE TO TRACK EAST. AFTER THAT...THE REST OF THE DAY IS
EXPECTED TO BE DRY...EXCEPT DID INCLUDE A SLIGHT CHANCE OF TSTMS
IN OUR FAR SRN COUNTIES TOWARD 6 PM AND THEN THROUGH EARLY THIS
EVENING. HRRR AND SOME OF THE OTHER HIGH RESOLUTION MODELS HAVE
GENERALLY BEEN TOO BULLISH WITH STORM DEVELOPMENT/COVERAGE THE
PAST FEW DAYS...BUT WEAK SIGNALS ARE THERE FOR POSSIBLE ISOLATED
ACTIVITY LATER TODAY. KEPT HIGHS CLOSE TO PREVIOUS FORECAST...
IN THE MID AND UPPER 90S.
THE 00Z GFS DEVELOPED MORE PCPN OVERNIGHT ALONG THE KS/NE BORDER
BUT FELT THAT WAS OVERDONE AT THIS POINT. HAVE MOST OF THE AREA
DRY OVERNIGHT WITH LOWS IN THE MID OR UPPER 60S NORTH AND LOWER
70S SOUTH. RIGHT NOW...TUESDAY LOOKS TO BE A FEW DEGREES COOLER
THAN TODAY...WITH HEAT INDICES STAYING MAINLY BELOW 100.
RAIN CHANCES START TO INCREASE TUESDAY NIGHT AND THEN MORE ON
WEDNESDAY AS HEIGHTS DECREASE A BIT. THIS WILL ALLOW SHORTWAVE
ENERGY TO MOVE OUT OF THE WESTERN UNITED STATES TROUGH AND TAP
INTO SOME MONSOONAL MOISTURE. DUE TO MORE CLOUD COVER...HAVE
HIGHS WEDNESDAY MAINLY 85 TO 90.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 310 AM CDT MON JUL 13 2015
500 MB RIDGE WILL GENERALLY REMAIN CENTERED OVER LA OR ERN TX
THROUGH THIS PERIOD. OUR AREA WILL BE MOSTLY IN SOUTHWEST MID
LEVEL FLOW...AHEAD OF THE TROUGH LOCATED MAINLY ACROSS THE PACIFIC
NORTHWEST. TEMPERATURES WILL GENERALLY BE SEASONAL WITH OCCASIONAL
SMALL CHANCES FOR PCPN. BEST CHANCES LOOK TO BE WEDNESDAY NIGHT
INTO THURSDAY AND THEN AGAIN SUNDAY NIGHT.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1222 PM CDT MON JUL 13 2015
VFR CONDITIONS THROUGH THE PERIOD WITH NORTHWEST FLOW AT ALL
SITES...BECOMING LIGHT AND VARIABLE BY 23-00Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR NEZ045-051>053-
066>068-078-088>093.
IA...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR IAZ055-056-069-079-
080-090-091.
&&
$$
UPDATE...DEWALD
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
639 AM CDT MON JUL 13 2015
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 310 AM CDT MON JUL 13 2015
HEAT AND HUMIDITY TODAY...ISOLATED STORMS INTO MID MORNING AND
THEN SLIGHT CHANCE OF TSTMS LATE TODAY INTO THIS EVENING ARE THE
PRIMARY FORECAST CONCERNS THROUGH THIS PERIOD.
UPPER AIR CHARTS FROM LAST EVENING SHOWED THE FOLLOWING. AT 300 MB
A JET STREAK OF 80-90 KNOTS EXTENDED FROM ERN WY ACROSS SRN SD. AT
500 MB...WEAK HEIGHT FALLS WERE MOVING EWD ACROSS THE DAKOTAS AND
MN AND RIDGE ALOFT WAS STILL CENTERED OVER TX. THERMAL RIDGE AT
700 MB STRETCHED FROM NM INTO CO AND KS. ACROSS NEBRASKA...700 MB
TEMPERATURES WERE GENERALLY 12-13 DEGREES C. THERMAL RIDGE AT 850
MB WAS LOCATED FROM NM INTO WRN SD. DRIER AIR WAS OVER THE HIGH
PLAINS BUT 850 MB DEWPOINTS WERE IN THE TEENS FROM IA BACK INTO
ERN NE. THE KOAX SOUNDING FROM 00Z WAS FAIRLY MOIST...WITH A
PRECIPITABLE WATER OF 1.48 INCHES. SURFACE ANALYSIS AT 08Z SHOWED
A TROUGH OF LOW PRESSURE CURVING FROM THE ERN SD INTO NWRN KS.
AHEAD OF THIS TROUGH...DEWPOINTS WERE MOSTLY IN THE 70S BUT DROP
TO 60S AND 50S WEST OF THE TROUGH.
JUST HOW FAST DRIER AIR WILL BE ABLE TO MOVE IN TODAY WILL HAVE A
BIG IMPACT ON HEAT INDICES. LEFT PREVIOUSLY ISSUED HEAT ADVISORY
AS IS...BUT MAY NEED A SLIGHT ADJUSTMENT LATER TODAY. OTHERWISE...
ISOLATED TSRA WERE OCCURRING OVER PARTS OF NERN NE. THESE WERE
VERY HIGH BASED...ABOVE THE MID LEVEL CAP AND POSSIBLY GETTING
SOME SUPPORT BY THE JET STREAK MENTIONED EARLIER AND VERY WEAK
MID LEVEL HEIGHT FALLS. THESE MAY LAST INTO MID MORNING AS THEY
CONTINUE TO TRACK EAST. AFTER THAT...THE REST OF THE DAY IS
EXPECTED TO BE DRY...EXCEPT DID INCLUDE A SLIGHT CHANCE OF TSTMS
IN OUR FAR SRN COUNTIES TOWARD 6 PM AND THEN THROUGH EARLY THIS
EVENING. HRRR AND SOME OF THE OTHER HIGH RESOLUTION MODELS HAVE
GENERALLY BEEN TOO BULLISH WITH STORM DEVELOPMENT/COVERAGE THE
PAST FEW DAYS...BUT WEAK SIGNALS ARE THERE FOR POSSIBLE ISOLATED
ACTIVITY LATER TODAY. KEPT HIGHS CLOSE TO PREVIOUS FORECAST...
IN THE MID AND UPPER 90S.
THE 00Z GFS DEVELOPED MORE PCPN OVERNIGHT ALONG THE KS/NE BORDER
BUT FELT THAT WAS OVERDONE AT THIS POINT. HAVE MOST OF THE AREA
DRY OVERNIGHT WITH LOWS IN THE MID OR UPPER 60S NORTH AND LOWER
70S SOUTH. RIGHT NOW...TUESDAY LOOKS TO BE A FEW DEGREES COOLER
THAN TODAY...WITH HEAT INDICES STAYING MAINLY BELOW 100.
RAIN CHANCES START TO INCREASE TUESDAY NIGHT AND THEN MORE ON
WEDNESDAY AS HEIGHTS DECREASE A BIT. THIS WILL ALLOW SHORTWAVE
ENERGY TO MOVE OUT OF THE WESTERN UNITED STATES TROUGH AND TAP
INTO SOME MONSOONAL MOISTURE. DUE TO MORE CLOUD COVER...HAVE
HIGHS WEDNESDAY MAINLY 85 TO 90.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 310 AM CDT MON JUL 13 2015
500 MB RIDGE WILL GENERALLY REMAIN CENTERED OVER LA OR ERN TX
THROUGH THIS PERIOD. OUR AREA WILL BE MOSTLY IN SOUTHWEST MID
LEVEL FLOW...AHEAD OF THE TROUGH LOCATED MAINLY ACROSS THE PACIFIC
NORTHWEST. TEMPERATURES WILL GENERALLY BE SEASONAL WITH OCCASIONAL
SMALL CHANCES FOR PCPN. BEST CHANCES LOOK TO BE WEDNESDAY NIGHT
INTO THURSDAY AND THEN AGAIN SUNDAY NIGHT.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 631 AM CDT MON JUL 13 2015
VFR CONDITIONS THROUGH THE TAF PERIOD. ISOLATED THUNDERSTORMS
EARLY THIS MORNING AT KOMA WITH CIGS BKN FL060-100. NOT SURE IF
THESE WILL MAKE IT TO KLNK...SO WILL MENTION SHOWERS EARLY AND
MONITOR FOR ANY OTHER POP UPS WITH THE COLD FRONT SLIPPING SOUTH
TODAY. SOME GUSTY WINDS POSSIBLE NEAR THE SHOWERS AND STORMS. NORTHWEST
WINDS TO INCREASE TO 10 TO 15KTS THIS MORNING AND THEN DIMINISH TO
LIGHT AND VARIABLE THIS EVENING.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT THIS EVENING
FOR NEZ045-051>053-066>068-078-088>093.
IA...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT THIS EVENING
FOR IAZ055-056-069-079-080-090-091.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...ZAPOTOCNY
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
310 AM CDT MON JUL 13 2015
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 310 AM CDT MON JUL 13 2015
HEAT AND HUMIDITY TODAY...ISOLATED STORMS INTO MID MORNING AND
THEN SLIGHT CHANCE OF TSTMS LATE TODAY INTO THIS EVENING ARE THE
PRIMARY FORECAST CONCERNS THROUGH THIS PERIOD.
UPPER AIR CHARTS FROM LAST EVENING SHOWED THE FOLLOWING. AT 300 MB
A JET STREAK OF 80-90 KNOTS EXTENDED FROM ERN WY ACROSS SRN SD. AT
500 MB...WEAK HEIGHT FALLS WERE MOVING EWD ACROSS THE DAKOTAS AND
MN AND RIDGE ALOFT WAS STILL CENTERED OVER TX. THERMAL RIDGE AT
700 MB STRETCHED FROM NM INTO CO AND KS. ACROSS NEBRASKA...700 MB
TEMPERATURES WERE GENERALLY 12-13 DEGREES C. THERMAL RIDGE AT 850
MB WAS LOCATED FROM NM INTO WRN SD. DRIER AIR WAS OVER THE HIGH
PLAINS BUT 850 MB DEWPOINTS WERE IN THE TEENS FROM IA BACK INTO
ERN NE. THE KOAX SOUNDING FROM 00Z WAS FAIRLY MOIST...WITH A
PRECIPITABLE WATER OF 1.48 INCHES. SURFACE ANALYSIS AT 08Z SHOWED
A TROUGH OF LOW PRESSURE CURVING FROM THE ERN SD INTO NWRN KS.
AHEAD OF THIS TROUGH...DEWPOINTS WERE MOSTLY IN THE 70S BUT DROP
TO 60S AND 50S WEST OF THE TROUGH.
JUST HOW FAST DRIER AIR WILL BE ABLE TO MOVE IN TODAY WILL HAVE A
BIG IMPACT ON HEAT INDICES. LEFT PREVIOUSLY ISSUED HEAT ADVISORY
AS IS...BUT MAY NEED A SLIGHT ADJUSTMENT LATER TODAY. OTHERWISE...
ISOLATED TSRA WERE OCCURRING OVER PARTS OF NERN NE. THESE WERE
VERY HIGH BASED...ABOVE THE MID LEVEL CAP AND POSSIBLY GETTING
SOME SUPPORT BY THE JET STREAK MENTIONED EARLIER AND VERY WEAK
MID LEVEL HEIGHT FALLS. THESE MAY LAST INTO MID MORNING AS THEY
CONTINUE TO TRACK EAST. AFTER THAT...THE REST OF THE DAY IS
EXPECTED TO BE DRY...EXCEPT DID INCLUDE A SLIGHT CHANCE OF TSTMS
IN OUR FAR SRN COUNTIES TOWARD 6 PM AND THEN THROUGH EARLY THIS
EVENING. HRRR AND SOME OF THE OTHER HIGH RESOLUTION MODELS HAVE
GENERALLY BEEN TOO BULLISH WITH STORM DEVELOPMENT/COVERAGE THE
PAST FEW DAYS...BUT WEAK SIGNALS ARE THERE FOR POSSIBLE ISOLATED
ACTIVITY LATER TODAY. KEPT HIGHS CLOSE TO PREVIOUS FORECAST...
IN THE MID AND UPPER 90S.
THE 00Z GFS DEVELOPED MORE PCPN OVERNIGHT ALONG THE KS/NE BORDER
BUT FELT THAT WAS OVERDONE AT THIS POINT. HAVE MOST OF THE AREA
DRY OVERNIGHT WITH LOWS IN THE MID OR UPPER 60S NORTH AND LOWER
70S SOUTH. RIGHT NOW...TUESDAY LOOKS TO BE A FEW DEGREES COOLER
THAN TODAY...WITH HEAT INDICES STAYING MAINLY BELOW 100.
RAIN CHANCES START TO INCREASE TUESDAY NIGHT AND THEN MORE ON
WEDNESDAY AS HEIGHTS DECREASE A BIT. THIS WILL ALLOW SHORTWAVE
ENERGY TO MOVE OUT OF THE WESTERN UNITED STATES TROUGH AND TAP
INTO SOME MONSOONAL MOISTURE. DUE TO MORE CLOUD COVER...HAVE
HIGHS WEDNESDAY MAINLY 85 TO 90.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 310 AM CDT MON JUL 13 2015
500 MB RIDGE WILL GENERALLY REMAIN CENTERED OVER LA OR ERN TX
THROUGH THIS PERIOD. OUR AREA WILL BE MOSTLY IN SOUTHWEST MID
LEVEL FLOW...AHEAD OF THE TROUGH LOCATED MAINLY ACROSS THE PACIFIC
NORTHWEST. TEMPERATURES WILL GENERALLY BE SEASONAL WITH OCCASIONAL
SMALL CHANCES FOR PCPN. BEST CHANCES LOOK TO BE WEDNESDAY NIGHT
INTO THURSDAY AND THEN AGAIN SUNDAY NIGHT.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1135 PM CDT SUN JUL 12 2015
DESPITE LARGE CAPE VALUES AND GOOD SHEAR ACROSS THE
AREA...CONVECTION HAS HAD A HARD TIME MAINTAINING ITSELF THIS
EVENING WEST OF THE AREA. MAY SEE SOME BRIEF HIT OR MISS THUNDER
AS SURFACE TROUGH MOVES ACROSS THE AREA DURING THE PERIOD BUT TOO
LIMITED TO MENTION. VFR CONDITIONS EXPECTED TO PREVAIL WITH WINDS
BECOMING NORTHERLY BEHIND THE TROUGH.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT THIS EVENING
FOR NEZ045-051>053-066>068-078-088>093.
IA...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT THIS EVENING
FOR IAZ055-056-069-079-080-090-091.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...FOBERT
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1136 PM CDT SUN JUL 12 2015
.SHORT TERM...(TONIGHT THROUGH WEDNESDAY)
ISSUED AT 319 PM CDT SUN JUL 12 2015
FEELS LIKE TEMPERATURES OUT THERE ARE VERY HOT...WITH MANY LOCATIONS
REPORTING HEAT INDICES AROUND 105 AT 3 PM. WE ARE ANTICIPATING THIS
AGAIN MONDAY FOR QUITE A FEW COUNTIES IN OUR SOUTHEASTERN CWA AND
IS THE MAIN CONCERN IN THE NEXT 24 HOURS.
LATEST WATER VAPOR IMAGERY AND RAP 500MB ANALYSIS SHOWS LARGE HIGH
PRESSURE DOME OVER THE SOUTHERN PLAINS WITH A SHORTWAVE TROUGH
MOVING ACROSS THE NORTHERN PLAINS. VERY HIGH SFC DEWPOINTS REMAIN
OVER THE AREA THIS AFTERNOON WITH READINGS VARYING BETWEEN THE
LOWER 70S IN OUR WEST TO THE UPPER 70S IN OUR EAST. WE ALSO HAVE
THE SPORADIC IOWA AWOS VALUES IN THE LOW 80S. LATEST SURFACE
ANALYSIS SHOWS LOW PRESSURE CENTERED OVER SOUTHEASTERN NORTH
DAKOTA WITH A SECONDARY LOW ACROSS SOUTHWEST KANSAS. A TROUGH IN
BETWEEN THESE TWO AREAS CURRENTLY EXTENDS ACROSS OUR FAR
NORTHWESTERN COUNTIES AND THIS FEATURE WILL CONTINUE TO SLOWLY
PUSH EAST ACROSS THE FORECAST AREA THROUGH MONDAY...BRINGING IN
LOWER DEWPOINTS TO THE AREA.
TEMPERATURES SHOULD MIX OUT INTO THE UPPER 90S NEAR THE BOUNDARY
MONDAY. COMBINED WITH MID-UPPER 70S DEWPOINTS IN THE SOUTHEASTERN
HALF OF THE CWA...WE SHOULD PUSH HEAT INDICES INTO THE ADVISORY
CATEGORY ONCE AGAIN SO DID HOIST AN ADVISORY FOR MONDAY.
WARM CONDITIONS WILL CONTINUE ON TUESDAY ALTHOUGH WILL NOT BE QUITE
AS HOT. HEAT INDICES WILL BE LOWER AS WELL WITH DEWPOINTS IN THE
60S. BY TUESDAY NIGHT...THE FIRST IN A SERIES OF SEVERAL
SHORTWAVES WILL BE PASSING THROUGH THE MID LEVELS. WITH AMPLE
MOISTURE IN THE ATMOSPHERE...WE CANNOT RULE OUT PCPN CHANCES WITH
ANY OF THESE WAVES. CONVECTION MAY BEGIN AS EARLY AS TUESDAY
EVENING OVER THE HIGH PLAINS ASSOCIATED WITH THE FIRST WAVE...THEN
SPREAD EAST INTO THE CWA OVERNIGHT TUESDAY NIGHT INTO WEDNESDAY
MORNING.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 319 PM CDT SUN JUL 12 2015
TSTM CHANCES CONTINUE WEDNESDAY NIGHT AS ANOTHER STRONG SHORTWAVE
MOVES ACROSS THE HIGH PLAINS DURING THE AFTERNOON WEDNESDAY AND
INTO OUR CWA WEDNESDAY EVENING. A STRONG SOUTHWESTERLY LOW LEVEL
JET SHOULD AID CONTINUED CONVECTION THROUGH THE OVERNIGHT HOURS.
THE AREA WILL REMAIN IN WEST/SOUTHWESTERLY FLOW ALOFT THROUGH NEXT
WEEKEND BRINGING SEVERAL SMALL CHANCES OF TSTMS THROUGH THE
PERIOD. TEMPS SHOULD BE QUITE SEASONABLE FOR THIS TIME OF YEAR.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1135 PM CDT SUN JUL 12 2015
DESPITE LARGE CAPE VALUES AND GOOD SHEAR ACROSS THE
AREA...CONVECTION HAS HAD A HARD TIME MAINTAINING ITSELF THIS
EVENING WEST OF THE AREA. MAY SEE SOME BRIEF HIT OR MISS THUNDER
AS SURFACE TROUGH MOVES ACROSS THE AREA DURING THE PERIOD BUT TOO
LIMITED TO MENTION. VFR CONDITIONS EXPECTED TO PREVAIL WITH WINDS
BECOMING NORTHERLY BEHIND THE TROUGH.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...HEAT ADVISORY FROM 1 PM TO 8 PM CDT MONDAY FOR NEZ045-051>053-
066>068-078-088>093.
IA...HEAT ADVISORY FROM 1 PM TO 8 PM CDT MONDAY FOR IAZ055-056-069-
079-080-090-091.
&&
$$
SHORT TERM...KERN
LONG TERM...KERN
AVIATION...FOBERT
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1131 PM MDT SUN JUL 12 2015
.AVIATION...
06Z TAF CYCLE
SHOWERS AND THUNDERSTORMS HAVE LARGELY DISSIPATED ACROSS THE
WESTERN HALF OF NEW MEXICO...AND THIS TREND SHOULD CONTINUE INTO
THE EARLY MORNING HOURS MONDAY. ACTIVITY HAS LARGELY TURNED TO
BATCHES OF LIGHT TO MODERATE RAIN WITH ONLY A FEW EMBEDDED
CONVECTIVE OR THUNDERSTORM CELLS LINGERING. THIS WILL LIMIT THE
AVIATION HAZARDS...BUT SOME ERRATIC GUSTY WINDS COULD ACCOMPANY
THESE STRONGER EMBEDDED CELLS. SCATTERED TO NUMEROUS
THUNDERSTORMS WILL REDEVELOP MONDAY AFTERNOON. STORMS ON MONDAY
WILL AGAIN FAVOR THE WESTERN TO CENTRAL AREAS OF NEW MEXICO WITH
THE USUAL THREATS OF GUSTY DOWNBURST WINDS...HEAVY DOWNPOURS...AND
SMALL HAIL.
52
&&
.PREV DISCUSSION...348 PM MDT SUN JUL 12 2015...
.SYNOPSIS...
AS UPPER LEVEL HIGH PRESSURE REMAINS ANCHORED OVER THE SOUTHERN
PLAINS A RATHER CLASSIC MONSOON MOISTURE PLUME WILL CONTINUE TO
BRING SCATTERED THUNDERSTORMS WITH LOCALLY HEAVY RAINFALL TO MUCH
OF CENTRAL AND WESTERN NEW MEXICO THIS EVENING THROUGH AT LEAST
MID WEEK. STORM COVERAGE IS EXPECTED TO TREND DOWN SOMEWHAT THURSDAY
AS DRY AIR ALOFT WORKS IN FROM THE WEST. THE MOISTURE PLUME RE-
ESTABLISHES ITSELF FRIDAY AND SATURDAY FOR A RETURN TO SCATTERED
ACTIVITY.
&&
.DISCUSSION...
UPPER LEVEL HIGH CENTERED NEAR LUBBOCK TX THIS AFTERNOON. MODELS
IN VERY GOOD AGREEMENT THAT DEEP SUBTROPICAL MOISTURE WILL CONTINUE
STREAMING INTO WESTERN AND CENTRAL NM THROUGH AT LEAST WEDNESDAY.
BOTH 18Z NAM12 AND 20Z HRRR PICKING UP ON PERTURBATION/VORT LOBE
CURRENTLY MOVING INTO FAR SE ARIZONA. BOTH MODELS BRING THIS
FEATURE INTO SWRN AND WEST CENTRAL NM AFTER MIDNIGHT...HELPING TO
KEEP SHOWERS AND STORMS GOING THERE THROUGH EARLY MONDAY MORNING.
MODELS CONTINUE TO SHIFT THE UPPER HIGH SLIGHTLY EASTWARD MONDAY
AND TUESDAY...ALLOWING STORMS TO PROPAGATE EWD MORE EASILY INTO
THE NE AND EAST-CENTRAL PLAINS. MODELS REMAIN IN RELATIVELY GOOD
AGREEMENT THAT SOME DRIER AIR ALOFT WILL ATTEMPT TO WORK INTO NW
AND NORTH-CENTRAL NM THURSDAY...LEADING TO A POSSIBLE DOWN DAY
THERE. THE DEEP MOISTURE PLUME HANGS TOUGH ELSEWHERE.
12Z GFS PROGGING AN INCREASE IN SELY WINDS BETWEEN THE UPPER HIGH
AND WHAT IS NOW TROPICAL STORM DOLORES. THIS INCREASING FLOW
HAS THE POTENTIAL TO TAP DEEP SUBTROPICAL MOISTURE AND DEEP
CONVECTION OVER FAR NW MEXICO AND SRN ARIZONA. 12Z GFS GOES SO FAR
AS TO DEVELOP A WARM CORE LOW OVER SE AZ/WRN NM THURSDAY NIGHT
AND FRIDAY. SUCH A FEATURE WOULD RESULT IN A MARKED INCREASE IN
HEAVY RAIN/FLASH FLOODING POTENTIAL FRIDAY INTO FRIDAY NIGHT. TOO
FAR OUT AT THIS POINT TO NAIL DOWN THE TIMING OF A FEATURE YET TO
DEVELOP BUT IT WILL BE CLOSELY MONITORED IN THE COMING DAYS.
SUNDAY COULD BE THE NEXT DOWNDAY AS THE UPPER HIGH ATTEMPTS TO
RETROGRADE WWD INTO SRN AZ. CONFIDENCE IN THIS SOLUTION REMAINS
LOW AS 12Z ECMWF KEEPS THE UPPER HIGH CENTER OVER SE NM...KEEPING
WRN AND NRN NM ACTIVE SUNDAY INTO EARLY NEXT WEEK.
33
&&
.FIRE WEATHER...
THE SHOWER AND THUNDERSTORM CROP TODAY IS GREATER IN
NUMBER AND AT LEAST AS VIGOROUS AS WAS THE CASE SAT...MOST TODAY
BEING ACROSS THE WEST TWO THIRDS OF THE STATE. MONSOONAL MOISTURE
PLUME HOLDING FIRM ACROSS THIS GENERAL AREA AND INTO EAST AZ. NO
MAJOR CHANGE IN OVERALL PATTERN FOR THE WORK WEEK...THOUGH FCST
MODELS ARE HINTING AT ANY SIGNIFICANT DRYING TO BE THU TO FRI AND
MAY BE SHORTER IN DURATION THAN WHAT WAS INDICATED THE PAST DAY OR
TWO. LESS INDICATION THAN 12 TO 24 HRS AGO OF A WEAK BACK DOOR FRONT
PUSHING INTO NE NM NEAR MON TO MON NIGHT PERIOD...THOUGH IF
CONVECTION DOES RAMP UP IN SE CO THERE STILL WILL LIKELY BE AT LEAST
A STORM COMPLEX OUTFLOW BOUNDARY INTO THE FAR NE. IF IT DOES NOT
HAPPEN THEN STORM COVERAGE IN NE NM MAY NOT INCREASE ALL THAT MUCH.
FCST MODELS FOR THE MOST PART CONTINUING TO DELAY...A FEW EVEN
ELIMINATE...THE BUILDING OF THE UPPER HIGH CENTER OVER THE STATE...
LEAVING THE MOISTURE PLUME MORE INTACT OVER WEST HALF OF NM. NEXT
WEEKEND INTO MID NEXT WEEK A TROPICAL SYSTEM IS STILL INDICATED AS
MOVING UP AND OVER THE RIDGE INTO CA WITH THE BULK OF ITS MOISTURE
WELL TO OUR WEST.
HIGH TEMPERATURES WILL REMAIN BELOW AVERAGE WEST...BUT RISE TO
AVERAGE OR SLIGHTLY ABOVE...THIS WEEK. VENT RATES GENERALLY GOOD TO
EXCELLENT ALTHOUGH SOME POCKETS OF FAIR TO POOR RATES WILL EXIST
NORTH AND WEST THROUGH WED...WITH SOME DECREASE POSS THU.
43
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1008 PM EDT TUE JUL 14 2015
.SYNOPSIS...THE FINAL DISTURBANCE IN THE UPPER TROUGH WILL PUSH
SOUTHEAST ACROSS NC TONIGHT. HIGH PRESSURE WILL BUILD INTO THE
REGION WEDNESDAY AND THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 PM TUESDAY...
..SLIGHT RISK OF SEVERE THUNDERSTORMS REMOVED...
IT APPEARS THAT RAPIDLY DEVELOPING CONVECTIVE INHIBITION WITH
NIGHTFALL WILL LIKELY NOT BE SUPPORTIVE OF REDEVELOPMENT OF THE
CONVECTIVE LINE AS THE REMNANTS MOVE OFF THE BLUE RIDGE OF VA/NC
INTO OUR NW PIEDMONT. THE MORE FAVORABLE CONVECTIVE PARAMETERS FOR
CONVECTION CONTINUE OVER CENTRAL AND NORTHERN VA AND THIS IS WHERE
THE LINE WAS RE-FIRING AND HEADED TOWARD RICHMOND.
WE WILL KEEP LOW CHANCE POP FOR SOME RESIDUAL SHOWERS AND ISOLATED
THUNDER CHANCE FOR A FEW MORE HOURS IN THE NW-NE PIEDMONT AND FAR NE
ZONES OF THE COASTAL PLAIN... OTHERWISE PARTLY CLOUDY OVERNIGHT.
LOWS 68-73.
PREVIOUS DISCUSSION AT 730 PM...
ANOTHER... THE LAST IN THE SERIES OF CONVECTIVE COMPLEXES WAS DIVING
SOUTHEAST INTO WESTERN AND SOUTHWESTERN VIRGINIA AIMED AT NORTHERN
NORTH CAROLINA AT 725 PM. THE HIGHEST INSTABILITY RESIDED OUT AHEAD
OF THE LINE OVER VIRGINIA. THE INSTABILITY AXIS WEAKENED BUT
EXTENDED INTO THE NORTHERN AND EASTERN SECTIONS OF NC. SURFACE DEW
POINTS WERE IN THE 70S NORTH AND EAST... AND 60S IN THE SW PIEDMONT.
DEEP LAYER SHEAR WAS BEST TO OUR NORTH AS WELL... BUT 35-45KT OF
SHEAR EXTENDED OVER THE REGION NEAR THE NC/VA BORDER.
INTERESTINGLY... EVEN AS THE LINE WAS ONLY 2-3 HOURS FROM
POTENTIALLY AFFECTING A PORTION OF OUR REGION... MANY OF THE NEAR
TERM MODELS INCLUDING THE ARW AND HRRR WERE FORECASTING THE CORE OF
THE MCS TO DIVE SOUTH THEN SOUTHWEST TOWARD BOONE/BRISTOL/TRI CITIES
AREA BY LATE EVENING. THE STORM PREDICTION CENTER FELT THAT THE LINE
WOULD CONTINUE MOVING SE AND EITHER MAINTAIN ITSELF OR WEAKEN...
THEN RE-INTENSIFY AS IT HITS A FAVORABLE ENVIRONMENT MENTIONED ABOVE
IN THE VA/FAR NORTHERN NC PIEDMONT. THIS IS WHERE A SEVERE
THUNDERSTORM WATCH WAS PLACED AS FAR SOUTH AS MOUNT AIRY AND
YANCEYVILLE THROUGH 100 AM.
JUST AS IN THE PREVIOUS NW FLOW CONVECTIVE COMPLEXES AND LINES THAT
HAVE AFFECTED OUR REGION - IT WILL LIKELY HAVE TO BE NOWCAST RATHER
THAN FORECAST AS TO THE HOW IT WILL AFFECT OUR REGION. AT THE
CURRENT TIME IT APPEARS LIKELY THAT AT LEAST THE NORTH-NORTHEAST
PIEDMONT FROM THE TRIAD TO ROXBORO TO THE NORTHERN PART OF THE
TRIANGLE WILL HAVE TO DEAL WITH AT LEAST SOME GUSTY WINDS AND
LOCALLY HEAVY RAIN BETWEEN 900 PM AND MIDNIGHT.
WE WILL MAINTAIN THE CURRENT FORECAST WORDING AND THE CURRENT
HAZARDOUS WEATHER OUTLOOK UNTIL THE THREAT FROM THIS SYSTEM
DIMINISHES OR PASSES. IT APPEARS THE THREAT OF SEVERE STORMS IS
LOWEST IN THE SOUTH AND WEST (WHERE THE CONVECTIVE PARAMETERS ARE
MUCH LOWER) - DUE TO SOME NEGATIVE RESIDUAL AFFECTS OF THE SYSTEM
THAT PASSED BY THIS MORNING AND THE CURRENT ONE THAT BRUSHED BY TO
THE WEST OF ASHEVILLE.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 315 PM TUESDAY...
A MID LEVEL TROUGH IS PROGGED TO BE SHIFTING OFF THE MID ATLANTIC
COAST THROUGHOUT THE DAY ON WEDNESDAY. AS THIS DOES SO...A COLD
FRONT WILL GRADUALLY TRACK ACROSS THE REGION...EVENTUALLY SETTLING
SOUTH OF THE AREA BY WEDNESDAY NIGHT. ALL OF THIS WILL LEAD TO A
DECREASE IN CONVECTIVE COVERAGE AS THE BEST FORCING AND MOISTURE
WILL GRADUALLY BE SHIFTING OFF TO THE NORTH AND EAST OF THE AREA.
THEREFORE...WILL SHOW A GRADUAL PROGRESSION OF DECREASING PRECIP
CHANCES FROM WEST TO EAST THROUGHOUT THE DAY...HOWEVER POPS WILL BE
NO HIGHER THAN SLIGHT CHANCE. TEMPS WILL BE SLIGHTLY ABOVE NORMAL
(RANGING FROM NEAR 90 DEGREES TO THE LOWER 90S)...ALTHOUGH HUMIDITY
VALUES WILL BE LOWER THAN PREVIOUS DAYS.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 315 PM TUESDAY...
THURSDAY AND FRIDAY...HEIGHTS WILL BEGIN TO RISE OVER THE REGION AS
THE AFOREMENTIONED MID LEVEL TROUGH (SEE SHORT TERM DISCUSSION
ABOVE) PULLS FURTHER OUT TO SEA. AT THE SURFACE...A NEARLY
STATIONARY FRONT WILL REMAIN SOUTH OF THE REGION...ALLOWING HIGH
PRESSURE TO RIDGE DOWN ONTO THE AREA. ALL OF THIS WILL RESULT IN
QUIET WEATHER TO CLOSE OUT THE WORK WEEK...WITH SLIGHTLY ABOVE
NORMAL TEMPS (BUT CONTINUED LOWER RELATIVE HUMIDITIES).
SATURDAY THROUGH TUESDAY...THE SURFACE HIGH PRESSURE WILL SHIFT
OFFSHORE TO BEGIN THE WEEKEND...ALLOWING MOISTURE TO RETURN TO THE
REGION. IN ADDITION...NORTHWESTERLY FLOW ALOFT WILL BECOME RE-
ESTABLISHED OVER THE REGION GIVEN THE MID LEVEL RIDGE OVER THE DEEP
SOUTH. ALL OF THIS WILL LEAD TO INCREASING CHANCES OF PRECIP...
MOSTLY DIURNAL IN NATURE. TEMPS WILL CONTINUE TO BE ABOVE NORMAL.
&&
.AVIATION /18Z TUESDAY THROUGH SATURDAY/...
AS OF 930 PM TUESDAY...
00-06Z WED: AN UPSTREAM MCS HAS SIGNIFICANTLY WEAKENED WHILE
PROPAGATING S/SW ACROSS THE WV/VA MOUNTAINS OVER THE PAST SEVERAL
HOURS. THOUGH ADDITIONAL CONVECTION MAY DEVELOP/PERSIST THROUGH 04Z
ON THE EASTERN PERIPHERY OF THE COLD POOL PROGRESSING EASTWARD
THROUGH CENTRAL VA...ADDITIONAL DEVELOPMENT IS EXTREMELY UNLIKELY
ALONG THE SOUTHERN PERIPHERY OF THE COLD POOL PROGRESSING SOUTH
TOWARD THE TRIAD/NW PIEDMONT IN THE 02-05Z TIME FRAME. AS A
RESULT...THE IMPACT OF THIS CONVECTIVE SYSTEM ON CENTRAL NC WILL BE
MINIMAL AT BEST AND CONFINED TO THE INT/GSO TERMINALS WHERE A WIND
SHIFT TO THE WNW/NW AT 10-15 KT (GUSTS UP TO 25 KT PERHAPS) CAN BE
EXPECTED INVOF THE 03-05Z TIME FRAME. A BRIEF PERIOD OF SUB-VFR
CONDITIONS ASSOC/W DECAYING SHOWER ACTIVITY ATTENDANT THE REMNANT
COLD POOL CANNOT BE RULED OUT AT INT/GSO DURING THE AFOREMENTIONED
TIME FRAME...THOUGH THE PROBABILITY THEREOF APPEARS LOW ENOUGH TO
PRECLUDE EXPLICIT MENTION.
06Z WED TO 00Z THU: VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH
THE REMAINDER OF THE TAF PERIOD AT ALL TERMINALS AS A DRIER AIRMASS
ADVECTS INTO THE REGION FROM THE NORTHWEST IN THE WAKE OF A COLD
FRONTAL PASSAGE DURING THE DAY WED. ISOLD CONVECTION WILL BE
POSSIBLE INVOF THE FRONT NEAR THE NC COAST WED AFTERNOON...THOUGH
ACTIVITY SHOULD REMAIN EAST/SOUTH OF THE FAY TERMINAL.
LOOKING AHEAD: VFR CONDITIONS WILL GENERALLY PREVAIL THROUGH THE
WEEKEND...ASIDE FROM A POTENTIAL FOR STRATUS /SUB-VFR CEILINGS/ 08-
14Z FRIDAY MORNING AND A CLIMATOLOGICAL POTENTIAL FOR DIURNAL
CONVECTION ATTENDANT MOISTURE RETURN EARLY NEXT WEEK. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...PWB
NEAR TERM...PWB
SHORT TERM...KRD
LONG TERM...KRD
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
950 PM EDT TUE JUL 14 2015
.SYNOPSIS...THE FINAL DISTURBANCE IN THE UPPER TROUGH WILL PUSH
SOUTHEAST ACROSS NC TONIGHT. HIGH PRESSURE WILL BUILD INTO THE
REGION WEDNESDAY AND THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 PM TUESDAY...
..SLIGHT RISK OF SEVERE THUNDERSTORMS REMOVED...
IT APPEARS THAT RAPIDLY DEVELOPING CONVECTIVE INHIBITION WITH
NIGHTFALL WILL LIKELY NOT BE SUPPORTATIVE OF REDEVELOPMENT OF THE
CONVECTIVE LINE AS THE REMNANTS MOVE OFF THE BLUE RIDGE OF VA/NC
INTO OUR NW PIEDMONT. THE MORE FAVORABLE CONVECTIVE PARAMETERS FOR
CONVECTION CONTINUE OVER CENTRAL AND NORTHERN VA AND THIS IS WHERE
THE LINE WAS REFIRING AND HEADED TOWARD RICHMOND.
WE WILL KEEP LOW CHANCE POP FOR SOME RESIDUAL SHOWERS AND ISOLATED
THUNDER CHANCE FOR A FEW MORE HOURS IN THE NW-NE PIEDMONT AND FAR NE
ZONES OF THE COASTAL PLAIN... OTHERWISE PARTLY CLOUDY OVERNIGHT.
LOWS 68-73.
PREVIOUS DISCUSSION AT 730 PM...
ANOTHER... THE LAST IN THE SERIES OF CONVECTIVE COMPLEXES WAS DIVING
SOUTHEAST INTO WESTERN AND SOUTHWESTERN VIRGINIA AIMED AT NORTHERN
NORTH CAROLINA AT 725 PM. THE HIGHEST INSTABILITY RESIDED OUT AHEAD
OF THE LINE OVER VIRGINIA. THE INSTABILITY AXIS WEAKENED BUT
EXTENDED INTO THE NORTHERN AND EASTERN SECTIONS OF NC. SURFACE DEW
POINTS WERE IN THE 70S NORTH AND EAST... AND 60S IN THE SW PIEDMONT.
DEEP LAYER SHEAR WAS BEST TO OUR NORTH AS WELL... BUT 35-45KT OF
SHEAR EXTENDED OVER THE REGION NEAR THE NC/VA BORDER.
INTERESTINGLY... EVEN AS THE LINE WAS ONLY 2-3 HOURS FROM
POTENTIALLY AFFECTING A PORTION OF OUR REGION... MANY OF THE NEAR
TERM MODELS INCLUDING THE ARW AND HRRR WERE FORECASTING THE CORE OF
THE MCS TO DIVE SOUTH THEN SOUTHWEST TOWARD BOONE/BRISTOL/TRI CITIES
AREA BY LATE EVENING. THE STORM PREDICTION CENTER FELT THAT THE LINE
WOULD CONTINUE MOVING SE AND EITHER MAINTAIN ITSELF OR WEAKEN...
THEN RE-INTENSIFY AS IT HITS A FAVORABLE ENVIRONMENT MENTIONED ABOVE
IN THE VA/FAR NORTHERN NC PIEDMONT. THIS IS WHERE A SEVERE
THUNDERSTORM WATCH WAS PLACED AS FAR SOUTH AS MOUNT AIRY AND
YANCEYVILLE THROUGH 100 AM.
JUST AS IN THE PREVIOUS NW FLOW CONVECTIVE COMPLEXES AND LINES THAT
HAVE AFFECTED OUR REGION - IT WILL LIKELY HAVE TO BE NOWCAST RATHER
THAN FORECAST AS TO THE HOW IT WILL AFFECT OUR REGION. AT THE
CURRENT TIME IT APPEARS LIKELY THAT AT LEAST THE NORTH-NORTHEAST
PIEDMONT FROM THE TRIAD TO ROXBORO TO THE NORTHERN PART OF THE
TRIANGLE WILL HAVE TO DEAL WITH AT LEAST SOME GUSTY WINDS AND
LOCALLY HEAVY RAIN BETWEEN 900 PM AND MIDNIGHT.
WE WILL MAINTAIN THE CURRENT FORECAST WORDING AND THE CURRENT
HAZARDOUS WEATHER OUTLOOK UNTIL THE THREAT FROM THIS SYSTEM
DIMINISHES OR PASSES. IT APPEARS THE THREAT OF SEVERE STORMS IS
LOWEST IN THE SOUTH AND WEST (WHERE THE CONVECTIVE PARAMETERS ARE
MUCH LOWER) - DUE TO SOME NEGATIVE RESIDUAL AFFECTS OF THE SYSTEM
THAT PASSED BY THIS MORNING AND THE CURRENT ONE THAT BRUSHED BY TO
THE WEST OF ASHEVILLE.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 315 PM TUESDAY...
A MID LEVEL TROUGH IS PROGGED TO BE SHIFTING OFF THE MID ATLANTIC
COAST THROUGHOUT THE DAY ON WEDNESDAY. AS THIS DOES SO...A COLD
FRONT WILL GRADUALLY TRACK ACROSS THE REGION...EVENTUALLY SETTLING
SOUTH OF THE AREA BY WEDNESDAY NIGHT. ALL OF THIS WILL LEAD TO A
DECREASE IN CONVECTIVE COVERAGE AS THE BEST FORCING AND MOISTURE
WILL GRADUALLY BE SHIFTING OFF TO THE NORTH AND EAST OF THE AREA.
THEREFORE...WILL SHOW A GRADUAL PROGRESSION OF DECREASING PRECIP
CHANCES FROM WEST TO EAST THROUGHOUT THE DAY...HOWEVER POPS WILL BE
NO HIGHER THAN SLIGHT CHANCE. TEMPS WILL BE SLIGHTLY ABOVE NORMAL
(RANGING FROM NEAR 90 DEGREES TO THE LOWER 90S)...ALTHOUGH HUMIDITY
VALUES WILL BE LOWER THAN PREVIOUS DAYS.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 315 PM TUESDAY...
THURSDAY AND FRIDAY...HEIGHTS WILL BEGIN TO RISE OVER THE REGION AS
THE AFOREMENTIONED MID LEVEL TROUGH (SEE SHORT TERM DISCUSSION
ABOVE) PULLS FURTHER OUT TO SEA. AT THE SURFACE...A NEARLY
STATIONARY FRONT WILL REMAIN SOUTH OF THE REGION...ALLOWING HIGH
PRESSURE TO RIDGE DOWN ONTO THE AREA. ALL OF THIS WILL RESULT IN
QUIET WEATHER TO CLOSE OUT THE WORK WEEK...WITH SLIGHTLY ABOVE
NORMAL TEMPS (BUT CONTINUED LOWER RELATIVE HUMIDITIES).
SATURDAY THROUGH TUESDAY...THE SURFACE HIGH PRESSURE WILL SHIFT
OFFSHORE TO BEGIN THE WEEKEND...ALLOWING MOISTURE TO RETURN TO THE
REGION. IN ADDITION...NORTHWESTERLY FLOW ALOFT WILL BECOME RE-
ESTABLISHED OVER THE REGION GIVEN THE MID LEVEL RIDGE OVER THE DEEP
SOUTH. ALL OF THIS WILL LEAD TO INCREASING CHANCES OF PRECIP...
MOSTLY DIURNAL IN NATURE. TEMPS WILL CONTINUE TO BE ABOVE NORMAL.
&&
.AVIATION /18Z TUESDAY THROUGH SATURDAY/...
AS OF 140 PM TUESDAY...
VFR CONDITIONS ACROSS CENTRAL NC THIS AFTERNOON WILL GENERALLY
CONTINUE INTO THE LATE AFTERNOON HOURS. AN ISOLATED SHOWER OR
THUNDERSTORM IS POSSIBLE...MAINLY TO THE WEST AND SOUTHWEST OF KGSO.
THE THREAT OF SHOWERS AND THUNDERSTORMS WILL INCREASE DURING THE
EVENING AS CONVECTION IS LIKELY TO DEVELOP ACROSS THE OH VALLEY AND
THE APPALACHIANS AND POTENTIALLY MOVE INTO CENTRAL NC BETWEEN 23Z
AND 06Z. CONFIDENCE IN THE EVOLUTION AND COVERAGE IS NOT GREAT SO
HAVE OPTED TO INCLUDE A MENTION OF SHOWERS WITH REDUCED CIGS AND
VSBYS. IF THE CONVECTION MAINTAINS ITSELF...SCT THUNDERSTORMS WITH
GUSTY WINDS CAN BE EXPECTED. THE THREAT OF CONVECTION AND
RESTRICTIONS WILL DECREASE FROM WEST TO EAST AFTER MIDNIGHT. PATCHY
MVFR STRATUS IS POSSIBLE TOWARD DAYBREAK...ESPECIALLY IN LOCATIONS
WITH PRECIPITATION. AFTER ANY LINGERING STRATUS BURNS OFF...VFR
CONDITIONS ARE EXPECTED ON WEDNESDAY. SOUTHWEST WINDS TODAY AT
AROUND 10KTS WITH GUSTS TO 15KTS OR SO WILL CONTINUE INTO THE
EVENING HOURS AND BECOME WESTERLY AT 10KTS WITH GUSTS UP TO 20 KTS
ON WEDNESDAY.
LOOKING AHEAD...A QUIETER PERIOD OF WEATHER WILL ARRIVE ON WEDNESDAY
AND PERSIST THROUGH THE WORK WEEK AS HIGH PRESSURE EXTENDS INTO THE
REGION. AN ISOLATED SHOWER OR THUNDERSTORM IS POSSIBLE DURING THE
AFTERNOON OR EVENING BUT THE COVERAGE SHOULD BE LIMITED. A SLIGHT
INCREASE IN AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS ARRIVES
FOR THE WEEKEND. -BLAES
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...PWB
NEAR TERM...PWB
SHORT TERM...KRD
LONG TERM...KRD
AVIATION...BLAES
AREA FORECAST DISCUSSION
NWS RALEIGH NC
725 PM EDT TUE JUL 14 2015
.SYNOPSIS...THE FINAL DISTURBANCE IN THE UPPER TROUGH WILL PUSH
SOUTHEAST ACROSS NC TONIGHT. HIGH PRESSURE WILL BUILD INTO THE
REGION WEDNESDAY AND THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 725 PM TUESDAY...
..SLIGHT RISK OF SEVERE THUNDERSTORMS OVER THE NORTHERN AND EASTERN
SECTIONS TONIGHT...
ANOTHER... THE LAST IN THE SERIES OF CONVECTIVE COMPLEXES WAS DIVING
SOUTHEAST INTO WESTERN AND SOUTHWESTERN VIRGINIA AIMED AT NORTHERN
NORTH CAROLINA AT 725 PM. THE HIGHEST INSTABILITY RESIDED OUT AHEAD
OF THE LINE OVER VIRGINIA. THE INSTABILITY AXIS WEAKENED BUT
EXTENDED INTO THE NORTHERN AND EASTERN SECTIONS OF NC. SURFACE DEW
POINTS WERE IN THE 70S NORTH AND EAST... AND 60S IN THE SW PIEDMONT.
DEEP LAYER SHEAR WAS BEST TO OUR NORTH AS WELL... BUT 35-45KT OF
SHEAR EXTENDED OVER THE REGION NEAR THE NC/VA BORDER.
INTERESTINGLY... EVEN AS THE LINE WAS ONLY 2-3 HOURS FROM
POTENTIALLY AFFECTING A PORTION OF OUR REGION... MANY OF THE NEAR
TERM MODELS INCLUDING THE ARW AND HRRR WERE FORECASTING THE CORE OF
THE MCS TO DIVE SOUTH THEN SOUTHWEST TOWARD BOONE/BRISTOL/TRI CITIES
AREA BY LATE EVENING. THE STORM PREDICTION CENTER FELT THAT THE LINE
WOULD CONTINUE MOVING SE AND EITHER MAINTAIN ITSELF OR WEAKEN...
THEN RE-INTENSIFY AS IT HITS A FAVORABLE ENVIRONMENT MENTIONED ABOVE
IN THE VA/FAR NORTHERN NC PIEDMONT. THIS IS WHERE A SEVERE
THUNDERSTORM WATCH WAS PLACED AS FAR SOUTH AS MOUNT AIRY AND
YANCEYVILLE THROUGH 100 AM.
JUST AS IN THE PREVIOUS NW FLOW CONVECTIVE COMPLEXES AND LINES THAT
HAVE AFFECTED OUR REGION - IT WILL LIKELY HAVE TO BE NOWCAST RATHER
THAN FORECAST AS TO THE HOW IT WILL AFFECT OUR REGION. AT THE
CURRENT TIME IT APPEARS LIKELY THAT AT LEAST THE NORTH-NORTHEAST
PIEDMONT FROM THE TRIAD TO ROXBORO TO THE NORTHERN PART OF THE
TRIANGLE WILL HAVE TO DEAL WITH AT LEAST SOME GUSTY WINDS AND
LOCALLY HEAVY RAIN BETWEEN 900 PM AND MIDNIGHT.
WE WILL MAINTAIN THE CURRENT FORECAST WORDING AND THE CURRENT
HAZARDOUS WEATHER OUTLOOK UNTIL THE THREAT FROM THIS SYSTEM
DIMINISHES OR PASSES. IT APPEARS THE THREAT OF SEVERE STORMS IS
LOWEST IN THE SOUTH AND WEST (WHERE THE CONVECTIVE PARAMETERS ARE
MUCH LOWER) - DUE TO SOME NEGATIVE RESIDUAL AFFECTS OF THE SYSTEM
THAT PASSED BY THIS MORNING AND THE CURRENT ONE THAT BRUSHED BY TO
THE WEST OF ASHEVILLE.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 315 PM TUESDAY...
A MID LEVEL TROUGH IS PROGGED TO BE SHIFTING OFF THE MID ATLANTIC
COAST THROUGHOUT THE DAY ON WEDNESDAY. AS THIS DOES SO...A COLD
FRONT WILL GRADUALLY TRACK ACROSS THE REGION...EVENTUALLY SETTLING
SOUTH OF THE AREA BY WEDNESDAY NIGHT. ALL OF THIS WILL LEAD TO A
DECREASE IN CONVECTIVE COVERAGE AS THE BEST FORCING AND MOISTURE
WILL GRADUALLY BE SHIFTING OFF TO THE NORTH AND EAST OF THE AREA.
THEREFORE...WILL SHOW A GRADUAL PROGRESSION OF DECREASING PRECIP
CHANCES FROM WEST TO EAST THROUGHOUT THE DAY...HOWEVER POPS WILL BE
NO HIGHER THAN SLIGHT CHANCE. TEMPS WILL BE SLIGHTLY ABOVE NORMAL
(RANGING FROM NEAR 90 DEGREES TO THE LOWER 90S)...ALTHOUGH HUMIDITY
VALUES WILL BE LOWER THAN PREVIOUS DAYS.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 315 PM TUESDAY...
THURSDAY AND FRIDAY...HEIGHTS WILL BEGIN TO RISE OVER THE REGION AS
THE AFOREMENTIONED MID LEVEL TROUGH (SEE SHORT TERM DISCUSSION
ABOVE) PULLS FURTHER OUT TO SEA. AT THE SURFACE...A NEARLY
STATIONARY FRONT WILL REMAIN SOUTH OF THE REGION...ALLOWING HIGH
PRESSURE TO RIDGE DOWN ONTO THE AREA. ALL OF THIS WILL RESULT IN
QUIET WEATHER TO CLOSE OUT THE WORK WEEK...WITH SLIGHTLY ABOVE
NORMAL TEMPS (BUT CONTINUED LOWER RELATIVE HUMIDITIES).
SATURDAY THROUGH TUESDAY...THE SURFACE HIGH PRESSURE WILL SHIFT
OFFSHORE TO BEGIN THE WEEKEND...ALLOWING MOISTURE TO RETURN TO THE
REGION. IN ADDITION...NORTHWESTERLY FLOW ALOFT WILL BECOME RE-
ESTABLISHED OVER THE REGION GIVEN THE MID LEVEL RIDGE OVER THE DEEP
SOUTH. ALL OF THIS WILL LEAD TO INCREASING CHANCES OF PRECIP...
MOSTLY DIURNAL IN NATURE. TEMPS WILL CONTINUE TO BE ABOVE NORMAL.
&&
.AVIATION /18Z TUESDAY THROUGH SATURDAY/...
AS OF 140 PM TUESDAY...
VFR CONDITIONS ACROSS CENTRAL NC THIS AFTERNOON WILL GENERALLY
CONTINUE INTO THE LATE AFTERNOON HOURS. AN ISOLATED SHOWER OR
THUNDERSTORM IS POSSIBLE...MAINLY TO THE WEST AND SOUTHWEST OF KGSO.
THE THREAT OF SHOWERS AND THUNDERSTORMS WILL INCREASE DURING THE
EVENING AS CONVECTION IS LIKELY TO DEVELOP ACROSS THE OH VALLEY AND
THE APPALACHIANS AND POTENTIALLY MOVE INTO CENTRAL NC BETWEEN 23Z
AND 06Z. CONFIDENCE IN THE EVOLUTION AND COVERAGE IS NOT GREAT SO
HAVE OPTED TO INCLUDE A MENTION OF SHOWERS WITH REDUCED CIGS AND
VSBYS. IF THE CONVECTION MAINTAINS ITSELF...SCT THUNDERSTORMS WITH
GUSTY WINDS CAN BE EXPECTED. THE THREAT OF CONVECTION AND
RESTRICTIONS WILL DECREASE FROM WEST TO EAST AFTER MIDNIGHT. PATCHY
MVFR STRATUS IS POSSIBLE TOWARD DAYBREAK...ESPECIALLY IN LOCATIONS
WITH PRECIPITATION. AFTER ANY LINGERING STRATUS BURNS OFF...VFR
CONDITIONS ARE EXPECTED ON WEDNESDAY. SOUTHWEST WINDS TODAY AT
AROUND 10KTS WITH GUSTS TO 15KTS OR SO WILL CONTINUE INTO THE
EVENING HOURS AND BECOME WESTERLY AT 10KTS WITH GUSTS UP TO 20 KTS
ON WEDNESDAY.
LOOKING AHEAD...A QUIETER PERIOD OF WEATHER WILL ARRIVE ON WEDNESDAY
AND PERSIST THROUGH THE WORK WEEK AS HIGH PRESSURE EXTENDS INTO THE
REGION. AN ISOLATED SHOWER OR THUNDERSTORM IS POSSIBLE DURING THE
AFTERNOON OR EVENING BUT THE COVERAGE SHOULD BE LIMITED. A SLIGHT
INCREASE IN AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS ARRIVES
FOR THE WEEKEND. -BLAES
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...PWB
NEAR TERM...PWB
SHORT TERM...KRD
LONG TERM...KRD
AVIATION...BLAES
AREA FORECAST DISCUSSION
NWS RALEIGH NC
335 PM EDT MON JUL 13 2015
.SYNOPSIS...AN INCREASINGLY ACTIVE NORTHWEST FLOW ALOFT WILL
BRING A SERIES OF DISTURBANCES ACROSS THE REGION THROUGH MIDWEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 335 PM MONDAY...
A SERIES OF DISTURBANCES ALOFT WILL CAUSE A L/W TROUGH TO AMPLIFY
OVER THE EASTERN U.S. THROUGH MID WEEK. THIS AMPLIFICATION WILL LEAD
TO AN INCREASE CHANCE FOR ACTIVE CONVECTIVE WEATHER ACROSS CENTRAL
NC THIS PERIOD.
REST OF THE AFTERNOON AND TONIGHT... SCATTERED CONVECTION WILL
PERSIST THROUGH THIS AFTERNOON IN VICINITY OF A DIFFERENTIAL HEATING
BOUNDARY OVER THE SANDHILLS EXTENDING INTO THE EASTERN PIEDMONT. THE
SLY LOW LEVEL FLOW IS FEEDING MODERATELY UNSTABLE AIR MASS INTO THIS
BOUNDARY. THE INSTABILITY AXIS AT MID AFTERNOON EXTENDS FROM THE
TRIAD INTO THE SOUTHERN PIEDMONT...SO EXPECT THE SCATTERED STORMS TO
EVENTUALLY GENERATE/BUILD WESTWARD INTO THIS SECTION OF THE FORECAST
AREA BY LATE THIS AFTERNOON-EARLY EVENING. EFFECTIVE SHEAR
RELATIVELY WEAK IN THIS REGION SO ORGANIZED BANDS OF CONVECTION
APPEAR TO BE MINIMAL LATE THIS AFTERNOON/EARLY EVENING. STORMS WHICH
EXHIBIT SUSTAINED UPDRAFTS AND ASSOCIATED PRECIP LOADING WILL HAVE
THE THREAT TO PRODUCE LOCALLY STRONG/DAMAGING WIND GUSTS WHEN THE
PRECIP LOAD DESCENDS TO THE SURFACE. THIS THREAT APPEARS TO BE
HIGHEST OVER THE WESTERN AND SOUTHERN PIEDMONT WHICH HAS SEEN THE
MOST HEATING TODAY.
LATER TONIGHT (AFTER 02Z-4Z)...CONVECTIVE COMPLEX CURRENTLY CROSSING
SOUTHERN OH-NORTHERN KY WILL BE APPROACHING OUR NW COUNTIES.
MAJORITY OF WRF MODELS DISSIPATE THIS COMPLEX AS IT MOVES SEWD INTO
OUR REGION...THOUGH THE PAST FEW RUNS OF THE HRRR DRAGS THIS SYSTEM
(THOUGH IN SOMEWHAT WEAKER FORM) ACROSS THE REGION. GFS HAS HAD A
STRONG SIGNAL THE PAST FEW RUNS A WELL...BRING THIS SYSTEM THOUGH
OVERNIGHT. THUS...WILL MAINTAIN A HIGH END CHANCE OF CONVECTION
ACROSS MOST OF THE PIEDMONT.
EFFECTIVE BULK SHEAR EXPECTED TO INCREASE TO BETWEEN 20-30KTS WITH
MLCAPE 400-800J/KG. THIS SUGGEST A CHANCE FOR ORGANIZED CONVECTION
IN THE FORM OF BROKEN BANDS WITH SOME BOWING FEATURES POSSIBLE.
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 335 PM MONDAY...
...RISK OF SEVERE THUNDERSTORMS WITH WIDESPREAD DAMAGING WINDS
PROBABLE TUESDAY NIGHT...
CONVECTIVE DEBRIS CLOUDINESS AND LINGERING SHOWERS OVER THE COASTAL
PLAIN WILL GRADUALLY MOVE OUT OR DIMINISH BY LATE MORNING. HEATING
OF THE MOIST AIR MASS WILL GENERATE A MODERATELY UNSTABLE ATMOSPHERE
BY AFTERNOON. A STEADY SW WIND AROUND 10KTS WITH GUSTS NEAR 20KTS
WILL PUSH AFTERNOON TEMPS WELL INTO THE 90S. NOT SEEING MUCH IN THE
MANNER OF A MECHANISM ALOFT TO TRIGGER ORGANIZED CONVECTION IN THE
AFTERNOON THOUGH PULSE TYPE THUNDERSTORMS A DEFINITE POSSIBILITY.
BULK SHEAR WILL BEGIN TO INCREASE LATE IN THE DAY...AND MORE SO
TUESDAY NIGHT AS A MID LEVEL 45-50KT ROUNDS THE BASE OF THE TROUGH.
THIS ENHANCED SHEAR WILL RESULT IN EFFECTIVE BULK SHEAR 30-40KTS. A
S/W RESPONSIBLE FOR CONVECTION EXPECTED TO FIRE OVER THE UPPER
MIDWEST THIS EVENING WILL INITIATE/SUSTAIN THIS CONVECTIVE COMPLEX
ACROSS CENTRAL NC. DUE TO THE STRONG HEATING EXPECTED TUESDAY
AFTERNOON...EXPECT DECENT LOW LEVEL LAPSE RATES TO PERSIST WELL INTO
THE EVENING HOURS. THE ENHANCED LOW LEVEL LAPSE RATES ALONG WITH THE
ABNORMALLY STRONG BULK SHEAR SUGGEST A GOOD PROBABILITY OF DAMAGING
WINDS WITH THE STRONGER/SEVERE STORMS. AN ISOLATED TORNADO OR TWO
CANNOT BE RULED OUT. THIS SEVERE WEATHER EPISODE MAY PERSIST WELL
INTO THE OVERNIGHT/PRE-DAWN HOURS.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 230 PM MONDAY...
THE UPPER TROUGH AXIS AND ASSOC SFC BOUNDARY ARE PROGGED TO MOVE
EAST OF I-95 BY 18Z WED...SO LOOK FOR PRECIP CHANCES TO WIND DOWN
DURING THE MORNING TO MID-DAY PERIOD WED. WITH THE AIRMASS CHANGE
LAGGING...HIGHS ON WED SHOULD STILL REACH THE LOW-MID 90S.
HIGH PRESSURE IN THE WAKE OF THE FRONT WILL BUILD INTO NC FOR THU
AND FRI...PROVIDING FAIR WEATHER AND COOLER TEMPS WITH READINGS NEAR
OR PERHAPS A FEW DEGREES BELOW NORMAL.
RAIN CHANCES WILL INCREASE BACK TO CLIMO AND PERHAPS ABOVE CLIMO
OVER THE WEEKEND INTO EARLY NEXT WEEK AS THE RIDGE CENTER OVER THE
LOWER MISS VALLEY MOVES WEST AND A SERIES OF SHORT WAVES ROUND THE
RIDGE TOP AND DROP SOUTHEAST ACROSS THE CAROLINAS. TEMPS DURING THIS
TIME WILL MODERATE BACK ABOVE NORMAL BY THE END OF THE WEEKEND AND
INTO MONDAY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 125 PM MONDAY...
AN ACTIVE WEATHER PATTERN ACROSS THE EASTERN U.S. WILL RESULT IN
PERIODS OF CONVECTION ACROSS CENTRAL NC THROUGH WEDNESDAY AND
ASSOCIATED MVFR/IFR CONDITIONS DUE TO CEILINGS AND HEAVY RAIN
SHOWERS. ASIDE FROM THE CONVECTION...EXPECT VFR CONDITIONS.
THE HIGHEST THREAT FOR WIDESPREAD CONVECTION APPEARS TO BE TWOFOLD:
THE FIRST LATE THIS EVENING THROUGH THE OVERNIGHT HOURS...STARTING
AROUND 03Z IN THE TRIAD...SPREADING EAST BY 06Z. THE SECOND HIGHER
THAN NORMAL THREAT WILL BE TUESDAY NIGHT INTO WEDNESDAY MORNING.
OTHERWISE...EXPECT ISOLATED TO SCATTERED CONVECTION LATER THIS
AFTERNOON THROUGH EARLY EVENING. THIS IMMEDIATE CONVECTIVE THREAT
APPEARS HIGHEST OVER THE NORTHERN PIEDMONT...AND MAY AFFECT THE
TRIAD AND KRDU TERMINALS BETWEEN 21Z-01Z.
FOR THURSDAY THROUGH SATURDAY...EXPECT A RETURN TO A MORE TYPICAL
SUMMER PATTERN WITH EXTENDED PERIODS OF VFR CONDITIONS WITH ISOLATED
CONVECTION HIGHLY PROBABLE IN THE AFTERNOON-EARLY EVENING HOURS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLAES/CBL
NEAR TERM...WSS
SHORT TERM...WSS
LONG TERM...RAH
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
653 AM EDT MON JUL 13 2015
.SYNOPSIS...
AN INLAND TROUGH AND HIGH PRESSURE OFFSHORE WILL PROVIDE A
CHANCE OF SHOWERS AND THUNDERSTORM EACH DAY THROUGH MID WEEK. A FEW
THUNDERSTORMS COULD BECOME STRONG TO SEVERE EACH AFTERNOON...
ESPECIALLY LATER TUESDAY AS LOW PRESSURE DEEPENS OVER THE AREA.
DRIER WEATHER WILL DEVELOP ON THURSDAY BUT A RETURN TO MORE HUMID
WEATHER WILL RETURN DURING THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 640 AM MONDAY...LONGWAVE UPPER PATTERN IS PRETTY MUCH SET
FOR THE REMAINDER OF THIS WEEK...WITH UPPER RIDGING ACROSS THE
MID- SECTION OF THE U.S. AND UPPER TROFFING LYING JUST OFF THE
MID- ATLANTIC AND SOUTHEAST COASTS. THIS LEAVES THE FORECAST AREA
UNDER THE INFLUENCE OF NW FLOW ALOFT...ACCOMPANIED BY THE
OCCASIONAL S/W TROF OR VORT DROPPING SOUTHEAST AFFECTING ALL OR
PORTIONS OF THE FA THIS PERIOD...AND SUBSEQUENT PERIODS THERE-
AFTER.
AT THE MOMENT...THE FA IS UNDER THE INFLUENCE OF A MID-LEVEL S/W
TROF EMBEDDED IN THIS UPPER NW FLOW. THE BEST DYNAMICS ACCORDING TO
THE RAP WILL STAY NORTH OF THE FA. ENOUGH JUICE IE. CAPE AND
MOISTURE IDENTIFIED BY MODEL SOUNDINGS REMAINS AVAILABLE FOR
CONVECTION THIS MORNING...MAINLY IN THE FORM OF SHOWERS. ITS NOT
UNTIL A FEW HRS AFTER DAYBREAK THAT MODEL SOUNDINGS INDICATE A MORE
FAVORABLE PROFILE...IE. INCREASING CAPE DUE TO THE DAYS
INSOLATION...FOR THUNDERSTORMS TO OCCUR. FOR THIS AFTERNOON AND
EVENING...MODELS...ESPECIALLY THE NAM...INDICATE SOME NVA SUBSIDENCE
ALOFT TO PUSH ACROSS THE FA IN THE WAKE OF THIS CURRENT MID-LEVEL
S/W TROF. WILL LEAN TOWARDS THE NAM...AND TONE DOWN THE POPS ACROSS
THE FA...ESPECIALLY ACROSS THE ILM SC COUNTIES. BEAR IN MIND STILL
THE THREAT FOR CONVECTION JUST NOT AS PRONOUNCED AS THE HRS LEADING
UP TO THIS AFTERNOON. SFC CONVERGENCE ALONG THE DEEPENING SFC TROF
ACROSS THE EASTERN CAROLINAS WILL AID THE CONTINUED LOW THREAT OF
CONVECTION THIS AFTN AND EVENING.
FOR THE LATE EVENING HOURS INTO THE PRE-DAWN HRS OF TUE...THE FA
ONCE AGAIN BECOMES UNDER THE INFLUENCE OF A MID-LEVEL S/W
TROF...WITH THE BEST DYNAMICS FROM THIS FEATURE AFFECTING MAINLY THE
ILM NC PORTIONS OF THE FA AND FURTHER NORTHWARD. HAVE INCREASED POPS
DURING THIS TIME PERIOD...HIER ACROSS THE ILM NC CWA. THERE IS A
POSSIBILITY THAT A NOCTURNAL MCS/MCC MAY DEVELOP UPSTREAM AND
EVENTUALLY DROP TO THE SOUTHEAST AND AFFECT THE FA LATE TONIGHT.
FOR MAX/MIN TEMPS...DID A BLEND OF AVBL MOS GUIDANCE. FOR MAX TEMPS
ONLY...LOWERED THIS BLEND BY A DEGREE OR 2 AS A RESULT OF MORE
WIDESPREAD OPAQUE CLOUDINESS AND THE SHRA/TSRA THREAT.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 340 AM MONDAY...ACTIVE PERIOD OF WEATHER EXPECTED TUESDAY INTO
WEDNESDAY...WITH AN ENHANCED RISK FOR SEVERE WEATHER HIGHLIGHTED BY
THE STORM PREDICTION CENTER ACROSS OUR WEST/NORTHWEST FORECAST AREA
TUESDAY. DURING TUESDAY STRONGER IMPULSES WILL APPROACH IN THE
NORTHWEST FLOW ALOFT WHILE AN H3 JET NOSES INTO THE CAROLINAS AS AN
INLAND SURFACE TROUGH STRENGTHENS. STRONG INSTABILITY IS EXPECTED
WITH BREEZY SOUTH-SOUTHWESTERLY FLOW PREVAILING EAST OF THE TROUGH.
THE PRESSURE GRADIENT WILL LIKELY LEAD TO A SEGMENTED RESULTANT
BOUNDARY ALONG THE COAST. OVERALL...THE PATTERN WILL SUPPORT
VEERING/INCREASING WINDS WITH HEIGHT AND SUBSEQUENT HELICITY IN
EXCESS OF 300 M2/S2 ACROSS INLAND AREAS. AS A RESULT...THINK THE
PRIMARY SEVERE WEATHER THREAT LATER TUESDAY WILL BE FROM DAMAGING
WINDS WITH SOME LARGE HAIL POSSIBLE...AND GIVEN THE AFOREMENTIONED
HELICITY CAN/T RULE OUT TORNADOES.
DURING WEDNESDAY...THE SURFACE TROUGH REMAINS INLAND WHILE THE H5
SHORT WAVE TROUGH WILL BEGIN SHIFTING OFF THE MID-ATLANTIC AND
CAROLINA COASTS DURING THE EVENING. THE PASSAGE OF THIS FEATURE
LEADS TO HIGHER CONFIDENCE THAT THE SURFACE BOUNDARY WILL FINALLY
PUSH OFF THE COAST LATE WEDNESDAY NIGHT. INSTABILITY MAY BE LOWER
COMPARED TO TUESDAY PER BUFKIT DURING WEDNESDAY...HOWEVER
ENOUGH WILL EXISTS ALONG WITH DECENT PRECIPITABLE WATER AND SUPPORT
ALOFT TO CONTINUE GOOD CHANCE SHOWERS/TSTMS. A FEW OF THESE STORMS
MAY BECOME STRONG TO SEVERE AS WELL. POPS WILL TREND LOWER WEDNESDAY
NIGHT AS THE TROUGH PUSHES FARTHER EAST. MAV MAX TEMPERATURES
WEDNESDAY MAY BE ON THE HIGH SIDE GIVEN THE COVERAGE OF STORMS
EXPECTED.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 340 AM MONDAY...THE H5 SHORTWAVE TROUGH WILL BE OFF THE MID-
ATLANTIC COAST EARLY THURSDAY...WHILE AT THE SURFACE THE TROUGH WILL
SHIFT OFFSHORE AS WEAK LOW PRESSURE EVOLVES OFF THE OUTER BANKS. THE
GFS HAS TRENDED TOWARD THIS SOLUTION OVER THE LAST DAY AND
CONFIDENCE IS INCREASING THAT THE PRECIPITABLE WATER WILL LOWER AND
THE BEST SURFACE FORCING WILL REMAIN OFFSHORE ASSOCIATED WITH THE
TROUGH DURING THURSDAY. AS A RESULT...LOWERED MAX TEMPERATURES A
CATEGORY AND LOWERED POPS AS WELL. BY FRIDAY NIGHT THE MID/UPPER
SUBTROPICAL RIDGE WILL BEGIN DRIFTING BACK TO THE WEST FROM THE MS
VALLEY ALLOWING A WEAK TROUGH TO BECOME RE-ESTABLISHED ACROSS THE
EAST COAST THIS WEEKEND. MEX GUIDANCE HAS TRENDED COOLER LIKELY
SINCE THE SURFACE FLOW IS ONSHORE...VERSUS THE HUMID SOUTHWEST FLOW
WE HAVE EXPERIENCED MULTIPLE DAYS THIS SUMMER. THUS...LOWERED MAX
TEMPS THIS WEEKEND...HOWEVER IN THE END MAX TEMPS MAY NEED TO BE
LOWERED ANOTHER CATEGORY OR TWO IF BETTER CONSISTENCY DEVELOPS IN
UPCOMING MODEL RUNS.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 12Z...A SERIES OF WEAK PERTURBATION WILL MOVE THROUGH IN THE
NORTHWEST FLOW OVER THE NEXT SEVERAL DAYS. TIMING OF THE CONVECTION
WILL BE DIFFICULT...WITH BEST CHANCES IN THE AFTERNOON. FLO IS
CURRENTLY IN IFR CONDITIONS...WHICH SHOULD MIX UP TO MVFR BY 14Z. WE
SHOULD GENERATE SOME DECENT CAPE THIS AFTERNOON...WITH ABOUT 25 KTS
OF SHEAR THIS COULD STIR UP SOME GOOD STORMS WITH BRIEF IFR
CONDITIONS AND GUSTY WINDS POSSIBLE.
EXTENDED OUTLOOK...POTENTIAL FOR BRIEF PERIODS OF MVFR IN
SHRA/TSRA. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 640 AM MONDAY...THE STORY FOR THIS PERIOD WILL BE THE
INCREASING SSW TO SW WINDS ACROSS THE AREA WATERS FROM MIDDAY THRU
TONIGHT...AND INTO SUBSEQUENT PERIODS. THIS A RESULT OF THE SFC PG
TIGHTENING BETWEEN AN AMPLIFIED NE-SW ORIENTED SFC TROF ACROSS THE
EAST-CENTRAL CAROLINAS...AND STRONG RIDGING FROM HIGH PRESSURE
CENTERED OVER THE HIGH SEAS WELL OUT IN THE ATLANTIC. LOOK FOR
WIND SPEEDS TO INCREASE TO AROUND 15 KT LATER THIS AFTERNOON...AND
FURTHER INCREASE TO A SOLID 15 TO 20 KT WITH POSSIBLE GUSTS UP TO
25 KT LATER TONIGHT. THE GUSTS IN PART FROM A 30+ KT LOW LEVEL JET
OCCURRING OVER THE AREA WATERS...VIA VARIOUS MODEL SOUNDINGS FOR
FRYING PAN SHOALS.
SIGNIFICANT SEAS WILL INITIALLY RUN AROUND 2 FT THRUOUT...THEN BEGIN
BUILDING TO AROUND 3 FT BY EARLY THIS EVENING...AND THEN FURTHER
BUILD TO 3 TO 5 FT THRUOUT BY LATE THIS EVENING AND THRU THE PRE-
DAWN TUE HOURS. A LAZY ESE 1 TO 1.5 FOOT GROUND SWELL WILL INITIALLY
DOMINATE THE SIG. SEAS. AS WINDS INCREASE...LOOK FOR LOCALLY
PRODUCED WIND DRIVEN WAVES AT 4 TO 5 SECOND PERIODS TO DOMINATE
LATE THIS AFTERNOON AND DEFINITELY DURING TONIGHT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 340 AM MONDAY...MARGINAL SMALL CRAFT CONDITIONS ARE POSSIBLE
TUESDAY AFTERNOON INTO WEDNESDAY AS A RESULT OF A TIGHTENED PRESSURE
GRADIENT AND RESULTANT SOUTHWEST FETCH. WIND WAVES WILL DOMINANT
DURING THIS PERIOD AS WELL AS THE BULK OF THE SPECTRAL WAVE ENERGY
IS FOCUSED IN THE 5-6 SEC RANGE. SIGNIFICANT WAVE HEIGHTS WILL BE IN
THE 3-5 FT WITHIN 10 NM AND POSSIBLE 5-6 FOOTERS ACROSS THE OUTER
WATERS. SEAS WILL SLOWLY SUBSIDE LATE WEDNESDAY NIGHT AS THE SURFACE
TROUGH PUSHES OFF THE COAST ALLOWING THE SOUTHWEST FETCH TO WEAKEN
AND VEER WITH ITS PASSAGE.
LONG TERM MARINE/THURSDAY THROUGH FRIDAY/
AS OF 340 AM MONDAY...INCREASING CONFIDENCE THAT THE SURFACE TROUGH
WILL SHIFT ACROSS THE WATERS BY THURSDAY MORNING AS WEAK LOW
PRESSURE EXISTS OFF THE OUTER BANKS. AS THIS COMES TO FRUITION THE
RATHER LIGHT FLOW WILL BECOME OFFSHORE...THEN VEER TO A LIGHT
NORTHEAST FLOW AS THE LOW EXITS TO THE NORTHEAST DURING THE EARLY
AFTERNOON. AS A WEAK RIDGE BUILDS IN FROM THE NORTHEAST THE
NORTHEAST TO EAST FLOW WILL PERSIST THROUGH FRIDAY. THINK CHANCES
FOR SHOWERS/TSTMS WILL DECREASE THURSDAY...WITH A FEW STORMS
POSSIBLE FRIDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SRP
NEAR TERM...DCH
SHORT TERM...SRP
LONG TERM...SRP
AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
608 EDT MON JUL 13 2015
.SYNOPSIS...
AN INLAND TROUGH AND HIGH PRESSURE OFFSHORE WILL PROVIDE A
CHANCE OF SHOWERS AND THUNDERSTORM EACH DAY THROUGH MID WEEK. A FEW
THUNDERSTORMS COULD BECOME STRONG TO SEVERE EACH AFTERNOON...
ESPECIALLY LATER TUESDAY AS LOW PRESSURE DEEPENS OVER THE AREA.
DRIER WEATHER WILL DEVELOP ON THURSDAY BUT A RETURN TO MORE HUMID
WEATHER WILL RETURN DURING THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 340 AM MONDAY...LONGWAVE UPPER PATTERN IS PRETTY MUCH SET FOR
THE REMAINDER OF THIS WEEK...WITH UPPER RIDGING ACROSS THE MID-
SECTION OF THE U.S. AND UPPER TROFFING LYING JUST OFF THE MID-
ATLANTIC AND SOUTHEAST COASTS. THIS LEAVES THE FORECAST AREA UNDER
THE INFLUENCE OF NW FLOW ALOFT...ACCOMPANIED BY THE OCCASIONAL S/W
TROF OR VORT DROPPING SOUTHEAST AFFECTING ALL OR PORTIONS OF THE FA
THIS PERIOD...AND SUBSEQUENT PERIODS THERE-AFTER.
AT THE MOMENT...THE FA IS UNDER THE INFLUENCE OF A MID-LEVEL S/W
TROF EMBEDDED IN THIS UPPER NW FLOW. THE BEST DYNAMICS ACCORDING TO
THE RAP WILL STAY NORTH OF THE FA. ENOUGH JUICE IE. CAPE AND
MOISTURE IDENTIFIED BY MODEL SOUNDINGS REMAINS AVAILABLE FOR
CONVECTION THIS MORNING...MAINLY IN THE FORM OF SHOWERS. ITS NOT
UNTIL A FEW HRS AFTER DAYBREAK THAT MODEL SOUNDINGS INDICATE A MORE
FAVORABLE PROFILE...IE. INCREASING CAPE DUE TO THE DAYS
INSOLATION...FOR THUNDERSTORMS TO OCCUR. FOR THIS AFTERNOON AND
EVENING...MODELS...ESPECIALLY THE NAM...INDICATE SOME NVA SUBSIDENCE
ALOFT TO PUSH ACROSS THE FA IN THE WAKE OF THIS CURRENT MID-LEVEL
S/W TROF. WILL LEAN TOWARDS THE NAM...AND TONE DOWN THE POPS ACROSS
THE FA...ESPECIALLY ACROSS THE ILM SC COUNTIES. BEAR IN MIND STILL
THE THREAT FOR CONVECTION JUST NOT AS PRONOUNCED AS THE HRS LEADING
UP TO THIS AFTERNOON. SFC CONVERGENCE ALONG THE DEEPENING SFC TROF
ACROSS THE EASTERN CAROLINAS WILL AID THE CONTINUED LOW THREAT OF
CONVECTION THIS AFTN AND EVENING.
FOR THE LATE EVENING HOURS INTO THE PRE-DAWN HRS OF TUE...THE FA
ONCE AGAIN BECOMES UNDER THE INFLUENCE OF A MID-LEVEL S/W
TROF...WITH THE BEST DYNAMICS FROM THIS FEATURE AFFECTING MAINLY THE
ILM NC PORTIONS OF THE FA AND FURTHER NORTHWARD. HAVE INCREASED POPS
DURING THIS TIME PERIOD...HIER ACROSS THE ILM NC CWA. THERE IS A
POSSIBILITY THAT A NOCTURNAL MCS/MCC MAY DEVELOP UPSTREAM AND
EVENTUALLY DROP TO THE SOUTHEAST AND AFFECT THE FA LATE TONIGHT.
FOR MAX/MIN TEMPS...DID A BLEND OF AVBL MOS GUIDANCE. FOR MAX TEMPS
ONLY...LOWERED THIS BLEND BY A DEGREE OR 2 AS A RESULT OF MORE
WIDESPREAD OPAQUE CLOUDINESS AND THE SHRA/TSRA THREAT.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 340 AM MONDAY...ACTIVE PERIOD OF WEATHER EXPECTED TUESDAY INTO
WEDNESDAY...WITH AN ENHANCED RISK FOR SEVERE WEATHER HIGHLIGHTED BY
THE STORM PREDICTION CENTER ACROSS OUR WEST/NORTHWEST FORECAST AREA
TUESDAY. DURING TUESDAY STRONGER IMPULSES WILL APPROACH IN THE
NORTHWEST FLOW ALOFT WHILE AN H3 JET NOSES INTO THE CAROLINAS AS AN
INLAND SURFACE TROUGH STRENGTHENS. STRONG INSTABILITY IS EXPECTED
WITH BREEZY SOUTH-SOUTHWESTERLY FLOW PREVAILING EAST OF THE TROUGH.
THE PRESSURE GRADIENT WILL LIKELY LEAD TO A SEGMENTED RESULTANT
BOUNDARY ALONG THE COAST. OVERALL...THE PATTERN WILL SUPPORT
VEERING/INCREASING WINDS WITH HEIGHT AND SUBSEQUENT HELICITY IN
EXCESS OF 300 M2/S2 ACROSS INLAND AREAS. AS A RESULT...THINK THE
PRIMARY SEVERE WEATHER THREAT LATER TUESDAY WILL BE FROM DAMAGING
WINDS WITH SOME LARGE HAIL POSSIBLE...AND GIVEN THE AFOREMENTIONED
HELICITY CAN/T RULE OUT TORNADOES.
DURING WEDNESDAY...THE SURFACE TROUGH REMAINS INLAND WHILE THE H5
SHORT WAVE TROUGH WILL BEGIN SHIFTING OFF THE MID-ATLANTIC AND
CAROLINA COASTS DURING THE EVENING. THE PASSAGE OF THIS FEATURE
LEADS TO HIGHER CONFIDENCE THAT THE SURFACE BOUNDARY WILL FINALLY
PUSH OFF THE COAST LATE WEDNESDAY NIGHT. INSTABILITY MAY BE LOWER
COMPARED TO TUESDAY PER BUFKIT DURING WEDNESDAY...HOWEVER
ENOUGH WILL EXISTS ALONG WITH DECENT PRECIPITABLE WATER AND SUPPORT
ALOFT TO CONTINUE GOOD CHANCE SHOWERS/TSTMS. A FEW OF THESE STORMS
MAY BECOME STRONG TO SEVERE AS WELL. POPS WILL TREND LOWER WEDNESDAY
NIGHT AS THE TROUGH PUSHES FARTHER EAST. MAV MAX TEMPERATURES
WEDNESDAY MAY BE ON THE HIGH SIDE GIVEN THE COVERAGE OF STORMS
EXPECTED.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 340 AM MONDAY...THE H5 SHORTWAVE TROUGH WILL BE OFF THE MID-
ATLANTIC COAST EARLY THURSDAY...WHILE AT THE SURFACE THE TROUGH WILL
SHIFT OFFSHORE AS WEAK LOW PRESSURE EVOLVES OFF THE OUTER BANKS. THE
GFS HAS TRENDED TOWARD THIS SOLUTION OVER THE LAST DAY AND
CONFIDENCE IS INCREASING THAT THE PRECIPITABLE WATER WILL LOWER AND
THE BEST SURFACE FORCING WILL REMAIN OFFSHORE ASSOCIATED WITH THE
TROUGH DURING THURSDAY. AS A RESULT...LOWERED MAX TEMPERATURES A
CATEGORY AND LOWERED POPS AS WELL. BY FRIDAY NIGHT THE MID/UPPER
SUBTROPICAL RIDGE WILL BEGIN DRIFTING BACK TO THE WEST FROM THE MS
VALLEY ALLOWING A WEAK TROUGH TO BECOME RE-ESTABLISHED ACROSS THE
EAST COAST THIS WEEKEND. MEX GUIDANCE HAS TRENDED COOLER LIKELY
SINCE THE SURFACE FLOW IS ONSHORE...VERSUS THE HUMID SOUTHWEST FLOW
WE HAVE EXPERIENCED MULTIPLE DAYS THIS SUMMER. THUS...LOWERED MAX
TEMPS THIS WEEKEND...HOWEVER IN THE END MAX TEMPS MAY NEED TO BE
LOWERED ANOTHER CATEGORY OR TWO IF BETTER CONSISTENCY DEVELOPS IN
UPCOMING MODEL RUNS.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 12Z...A SERIES OF WEAK PERTURBATION WILL MOVE THROUGH IN THE
NORTHWEST FLOW OVER THE NEXT SEVERAL DAYS. TIMING OF THE CONVECTION
WILL BE DIFFICULT...WITH BEST CHANCES IN THE AFTERNOON. FLO IS
CURRENTLY IN IFR CONDITIONS...WHICH SHOULD MIX UP TO MVFR BY 14Z. WE
SHOULD GENERATE SOME DECENT CAPE THIS AFTERNOON...WITH ABOUT 25 KTS
OF SHEAR THIS COULD STIR UP SOME GOOD STORMS WITH BRIEF IFR
CONDITIONS AND GUSTY WINDS POSSIBLE.
EXTENDED OUTLOOK...POTENTIAL FOR BRIEF PERIODS OF MVFR IN
SHRA/TSRA. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 340 AM MONDAY...THE STORY FOR THIS PERIOD WILL BE THE
INCREASING SSW TO SW WINDS ACROSS THE AREA WATERS FROM MIDDAY THRU
TONIGHT...AND INTO SUBSEQUENT PERIODS. THIS A RESULT OF THE SFC PG
TIGHTENING BETWEEN AN AMPLIFIED NE-SW ORIENTED SFC TROF ACROSS THE
EAST-CENTRAL CAROLINAS...AND STRONG RIDGING FROM HIGH PRESSURE
CENTERED OVER THE HIGH SEAS WELL OUT IN THE ATLANTIC. LOOK FOR WIND
SPEEDS TO INCREASE TO AROUND 15 KT LATER THIS AFTERNOON...AND
FURTHER INCREASE TO A SOLID 15 TO 20 KT WITH POSSIBLE GUSTS UP TO 25
KT LATER TONIGHT. THE GUSTS IN PART FROM A 30+ KT LOW LEVEL JET
OCCURRING OVER THE AREA WATERS...VIA VARIOUS MODEL SOUNDINGS FOR
FRYING PAN SHOALS.
SIGNIFICANT SEAS WILL INITIALLY RUN AROUND 2 FT THRUOUT...THEN BEGIN
BUILDING TO AROUND 3 FT BY EARLY THIS EVENING...AND THEN FURTHER
BUILD TO 3 TO 5 FT THRUOUT BY LATE THIS EVENING AND THRU THE PRE-
DAWN TUE HOURS. A LAZY ESE 1 TO 1.5 FOOT GROUND SWELL WILL INITIALLY
DOMINATE THE SIG. SEAS. AS WINDS INCREASE...LOOK FOR LOCALLY
PRODUCED WIND DRIVEN WAVES AT 4 TO 5 SECOND PERIODS TO DOMINATE
LATE THIS AFTERNOON AND DEFINITELY DURING TONIGHT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 340 AM MONDAY...MARGINAL SMALL CRAFT CONDITIONS ARE POSSIBLE
TUESDAY AFTERNOON INTO WEDNESDAY AS A RESULT OF A TIGHTENED PRESSURE
GRADIENT AND RESULTANT SOUTHWEST FETCH. WIND WAVES WILL DOMINANT
DURING THIS PERIOD AS WELL AS THE BULK OF THE SPECTRAL WAVE ENERGY
IS FOCUSED IN THE 5-6 SEC RANGE. SIGNIFICANT WAVE HEIGHTS WILL BE IN
THE 3-5 FT WITHIN 10 NM AND POSSIBLE 5-6 FOOTERS ACROSS THE OUTER
WATERS. SEAS WILL SLOWLY SUBSIDE LATE WEDNESDAY NIGHT AS THE SURFACE
TROUGH PUSHES OFF THE COAST ALLOWING THE SOUTHWEST FETCH TO WEAKEN
AND VEER WITH ITS PASSAGE.
LONG TERM MARINE/THURSDAY THROUGH FRIDAY/
AS OF 340 AM MONDAY...INCREASING CONFIDENCE THAT THE SURFACE TROUGH
WILL SHIFT ACROSS THE WATERS BY THURSDAY MORNING AS WEAK LOW
PRESSURE EXISTS OFF THE OUTER BANKS. AS THIS COMES TO FRUITION THE
RATHER LIGHT FLOW WILL BECOME OFFSHORE...THEN VEER TO A LIGHT
NORTHEAST FLOW AS THE LOW EXITS TO THE NORTHEAST DURING THE EARLY
AFTERNOON. AS A WEAK RIDGE BUILDS IN FROM THE NORTHEAST THE
NORTHEAST TO EAST FLOW WILL PERSIST THROUGH FRIDAY. THINK CHANCES
FOR SHOWERS/TSTMS WILL DECREASE THURSDAY...WITH A FEW STORMS
POSSIBLE FRIDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DCH
SHORT TERM...SRP
LONG TERM...SRP
AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
346 AM EDT MON JUL 13 2015
.SYNOPSIS...
AN INLAND TROUGH AND HIGH PRESSURE OFFSHORE WILL PROVIDE A
CHANCE OF SHOWERS AND THUNDERSTORM EACH DAY THROUGH MID WEEK. A FEW
THUNDERSTORMS COULD BECOME STRONG TO SEVERE EACH AFTERNOON...
ESPECIALLY LATER TUESDAY AS LOW PRESSURE DEEPENS OVER THE AREA.
DRIER WEATHER WILL DEVELOP ON THURSDAY BUT A RETURN TO MORE HUMID
WEATHER WILL RETURN DURING THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 340 AM MONDAY...LONGWAVE UPPER PATTERN IS PRETTY MUCH SET FOR
THE REMAINDER OF THIS WEEK...WITH UPPER RIDGING ACROSS THE MID-
SECTION OF THE U.S. AND UPPER TROFFING LYING JUST OFF THE MID-
ATLANTIC AND SOUTHEAST COASTS. THIS LEAVES THE FORECAST AREA UNDER
THE INFLUENCE OF NW FLOW ALOFT...ACCOMPANIED BY THE OCCASIONAL S/W
TROF OR VORT DROPPING SOUTHEAST AFFECTING ALL OR PORTIONS OF THE FA
THIS PERIOD...AND SUBSEQUENT PERIODS THERE-AFTER.
AT THE MOMENT...THE FA IS UNDER THE INFLUENCE OF A MID-LEVEL S/W
TROF EMBEDDED IN THIS UPPER NW FLOW. THE BEST DYNAMICS ACCORDING TO
THE RAP WILL STAY NORTH OF THE FA. ENOUGH JUICE IE. CAPE AND
MOISTURE IDENTIFIED BY MODEL SOUNDINGS REMAINS AVAILABLE FOR
CONVECTION THIS MORNING...MAINLY IN THE FORM OF SHOWERS. ITS NOT
UNTIL A FEW HRS AFTER DAYBREAK THAT MODEL SOUNDINGS INDICATE A MORE
FAVORABLE PROFILE...IE. INCREASING CAPE DUE TO THE DAYS
INSOLATION...FOR THUNDERSTORMS TO OCCUR. FOR THIS AFTERNOON AND
EVENING...MODELS...ESPECIALLY THE NAM...INDICATE SOME NVA SUBSIDENCE
ALOFT TO PUSH ACROSS THE FA IN THE WAKE OF THIS CURRENT MID-LEVEL
S/W TROF. WILL LEAN TOWARDS THE NAM...AND TONE DOWN THE POPS ACROSS
THE FA...ESPECIALLY ACROSS THE ILM SC COUNTIES. BEAR IN MIND STILL
THE THREAT FOR CONVECTION JUST NOT AS PRONOUNCED AS THE HRS LEADING
UP TO THIS AFTERNOON. SFC CONVERGENCE ALONG THE DEEPENING SFC TROF
ACROSS THE EASTERN CAROLINAS WILL AID THE CONTINUED LOW THREAT OF
CONVECTION THIS AFTN AND EVENING.
FOR THE LATE EVENING HOURS INTO THE PRE-DAWN HRS OF TUE...THE FA
ONCE AGAIN BECOMES UNDER THE INFLUENCE OF A MID-LEVEL S/W
TROF...WITH THE BEST DYNAMICS FROM THIS FEATURE AFFECTING MAINLY THE
ILM NC PORTIONS OF THE FA AND FURTHER NORTHWARD. HAVE INCREASED POPS
DURING THIS TIME PERIOD...HIER ACROSS THE ILM NC CWA. THERE IS A
POSSIBILITY THAT A NOCTURNAL MCS/MCC MAY DEVELOP UPSTREAM AND
EVENTUALLY DROP TO THE SOUTHEAST AND AFFECT THE FA LATE TONIGHT.
FOR MAX/MIN TEMPS...DID A BLEND OF AVBL MOS GUIDANCE. FOR MAX TEMPS
ONLY...LOWERED THIS BLEND BY A DEGREE OR 2 AS A RESULT OF MORE
WIDESPREAD OPAQUE CLOUDINESS AND THE SHRA/TSRA THREAT.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 340 AM MONDAY...ACTIVE PERIOD OF WEATHER EXPECTED TUESDAY INTO
WEDNESDAY...WITH AN ENHANCED RISK FOR SEVERE WEATHER HIGHLIGHTED BY
THE STORM PREDICTION CENTER ACROSS OUR WEST/NORTHWEST FORECAST AREA
TUESDAY. DURING TUESDAY STRONGER IMPULSES WILL APPROACH IN THE
NORTHWEST FLOW ALOFT WHILE AN H3 JET NOSES INTO THE CAROLINAS AS AN
INLAND SURFACE TROUGH STRENGTHENS. STRONG INSTABILITY IS EXPECTED
WITH BREEZY SOUTH-SOUTHWESTERLY FLOW PREVAILING EAST OF THE TROUGH.
THE PRESSURE GRADIENT WILL LIKELY LEAD TO A SEGMENTED RESULTANT
BOUNDARY ALONG THE COAST. OVERALL...THE PATTERN WILL SUPPORT
VEERING/INCREASING WINDS WITH HEIGHT AND SUBSEQUENT HELICITY IN
EXCESS OF 300 M2/S2 ACROSS INLAND AREAS. AS A RESULT...THINK THE
PRIMARY SEVERE WEATHER THREAT LATER TUESDAY WILL BE FROM DAMAGING
WINDS WITH SOME LARGE HAIL POSSIBLE...AND GIVEN THE AFOREMENTIONED
HELICITY CAN/T RULE OUT TORNADOES.
DURING WEDNESDAY...THE SURFACE TROUGH REMAINS INLAND WHILE THE H5
SHORT WAVE TROUGH WILL BEGIN SHIFTING OFF THE MID-ATLANTIC AND
CAROLINA COASTS DURING THE EVENING. THE PASSAGE OF THIS FEATURE
LEADS TO HIGHER CONFIDENCE THAT THE SURFACE BOUNDARY WILL FINALLY
PUSH OFF THE COAST LATE WEDNESDAY NIGHT. INSTABILITY MAY BE LOWER
COMPARED TO TUESDAY PER BUFKIT DURING WEDNESDAY...HOWEVER
ENOUGH WILL EXISTS ALONG WITH DECENT PRECIPITABLE WATER AND SUPPORT
ALOFT TO CONTINUE GOOD CHANCE SHOWERS/TSTMS. A FEW OF THESE STORMS
MAY BECOME STRONG TO SEVERE AS WELL. POPS WILL TREND LOWER WEDNESDAY
NIGHT AS THE TROUGH PUSHES FARTHER EAST. MAV MAX TEMPERATURES
WEDNESDAY MAY BE ON THE HIGH SIDE GIVEN THE COVERAGE OF STORMS
EXPECTED.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 340 AM MONDAY...THE H5 SHORTWAVE TROUGH WILL BE OFF THE MID-
ATLANTIC COAST EARLY THURSDAY...WHILE AT THE SURFACE THE TROUGH WILL
SHIFT OFFSHORE AS WEAK LOW PRESSURE EVOLVES OFF THE OUTER BANKS. THE
GFS HAS TRENDED TOWARD THIS SOLUTION OVER THE LAST DAY AND
CONFIDENCE IS INCREASING THAT THE PRECIPITABLE WATER WILL LOWER AND
THE BEST SURFACE FORCING WILL REMAIN OFFSHORE ASSOCIATED WITH THE
TROUGH DURING THURSDAY. AS A RESULT...LOWERED MAX TEMPERATURES A
CATEGORY AND LOWERED POPS AS WELL. BY FRIDAY NIGHT THE MID/UPPER
SUBTROPICAL RIDGE WILL BEGIN DRIFTING BACK TO THE WEST FROM THE MS
VALLEY ALLOWING A WEAK TROUGH TO BECOME RE-ESTABLISHED ACROSS THE
EAST COAST THIS WEEKEND. MEX GUIDANCE HAS TRENDED COOLER LIKELY
SINCE THE SURFACE FLOW IS ONSHORE...VERSUS THE HUMID SOUTHWEST FLOW
WE HAVE EXPERIENCED MULTIPLE DAYS THIS SUMMER. THUS...LOWERED MAX
TEMPS THIS WEEKEND...HOWEVER IN THE END MAX TEMPS MAY NEED TO BE
LOWERED ANOTHER CATEGORY OR TWO IF BETTER CONSISTENCY DEVELOPS IN
UPCOMING MODEL RUNS.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 06Z...MAINLY VFR CONDITIONS TO CONTINUE THROUGH THE EARLY
MORNING HOURS WITH ISOLATED -SHRA POSSIBLE WITHIN THE NW FLOW
ALOFT.
ON THE WHOLE...EXPECT VFR CONDITIONS TO DOMINATE THROUGHOUT DAYTIME
MON THRU MON EVENING. THE TIMING AND EXACT LOCATION OF
ISOLATED/SCATTERED SHOWERS AND THUNDERSTORMS WILL BE DIFFICULT TO
PINPOINT AHEAD OF A WEAK UPPER LEVEL IMPULSE WITHIN THE NW FLOW
ALOFT. AGAIN...THE TIMING FOR BRIEF PERIODS OF MVFR AND EVEN
POSSIBLE IFR FROM THE STRONGER CONVECTION...REMAINS THE CHALLENGE.
FOR NOW WILL INDICATE VCNTY SHRA ALL TERMINALS FOR THIS MORNING.
THEN...TRANSITION TO TSRA DURING DAYTIME/EVENING MONDAY. WINDS
SSE TO SW AT 3 TO 6 KT THIS MORNING...BECOMING 6 TO 12 KT DURING
DAYTIME/EVENING MONDAY...WITH POSSIBLE GUSTS 15+ KT ALONG THE
IMMEDIATE COAST.
EXTENDED OUTLOOK...POTENTIAL FOR BRIEF PERIODS OF MVFR IN
SHRA/TSRA. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 340 AM MONDAY...THE STORY FOR THIS PERIOD WILL BE THE
INCREASING SSW TO SW WINDS ACROSS THE AREA WATERS FROM MIDDAY THRU
TONIGHT...AND INTO SUBSEQUENT PERIODS. THIS A RESULT OF THE SFC PG
TIGHTENING BETWEEN AN AMPLIFIED NE-SW ORIENTED SFC TROF ACROSS THE
EAST-CENTRAL CAROLINAS...AND STRONG RIDGING FROM HIGH PRESSURE
CENTERED OVER THE HIGH SEAS WELL OUT IN THE ATLANTIC. LOOK FOR WIND
SPEEDS TO INCREASE TO AROUND 15 KT LATER THIS AFTERNOON...AND
FURTHER INCREASE TO A SOLID 15 TO 20 KT WITH POSSIBLE GUSTS UP TO 25
KT LATER TONIGHT. THE GUSTS IN PART FROM A 30+ KT LOW LEVEL JET
OCCURRING OVER THE AREA WATERS...VIA VARIOUS MODEL SOUNDINGS FOR
FRYING PAN SHOALS.
SIGNIFICANT SEAS WILL INITIALLY RUN AROUND 2 FT THRUOUT...THEN BEGIN
BUILDING TO AROUND 3 FT BY EARLY THIS EVENING...AND THEN FURTHER
BUILD TO 3 TO 5 FT THRUOUT BY LATE THIS EVENING AND THRU THE PRE-
DAWN TUE HOURS. A LAZY ESE 1 TO 1.5 FOOT GROUND SWELL WILL INITIALLY
DOMINATE THE SIG. SEAS. AS WINDS INCREASE...LOOK FOR LOCALLY
PRODUCED WIND DRIVEN WAVES AT 4 TO 5 SECOND PERIODS TO DOMINATE
LATE THIS AFTERNOON AND DEFINITELY DURING TONIGHT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 340 AM MONDAY...MARGINAL SMALL CRAFT CONDITIONS ARE POSSIBLE
TUESDAY AFTERNOON INTO WEDNESDAY AS A RESULT OF A TIGHTENED PRESSURE
GRADIENT AND RESULTANT SOUTHWEST FETCH. WIND WAVES WILL DOMINANT
DURING THIS PERIOD AS WELL AS THE BULK OF THE SPECTRAL WAVE ENERGY
IS FOCUSED IN THE 5-6 SEC RANGE. SIGNIFICANT WAVE HEIGHTS WILL BE IN
THE 3-5 FT WITHIN 10 NM AND POSSIBLE 5-6 FOOTERS ACROSS THE OUTER
WATERS. SEAS WILL SLOWLY SUBSIDE LATE WEDNESDAY NIGHT AS THE SURFACE
TROUGH PUSHES OFF THE COAST ALLOWING THE SOUTHWEST FETCH TO WEAKEN
AND VEER WITH ITS PASSAGE.
LONG TERM MARINE/THURSDAY THROUGH FRIDAY/
AS OF 340 AM MONDAY...INCREASING CONFIDENCE THAT THE SURFACE TROUGH
WILL SHIFT ACROSS THE WATERS BY THURSDAY MORNING AS WEAK LOW
PRESSURE EXISTS OFF THE OUTER BANKS. AS THIS COMES TO FRUITION THE
RATHER LIGHT FLOW WILL BECOME OFFSHORE...THEN VEER TO A LIGHT
NORTHEAST FLOW AS THE LOW EXITS TO THE NORTHEAST DURING THE EARLY
AFTERNOON. AS A WEAK RIDGE BUILDS IN FROM THE NORTHEAST THE
NORTHEAST TO EAST FLOW WILL PERSIST THROUGH FRIDAY. THINK CHANCES
FOR SHOWERS/TSTMS WILL DECREASE THURSDAY...WITH A FEW STORMS
POSSIBLE FRIDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DCH
SHORT TERM...SRP
LONG TERM...SRP
AVIATION...DCH
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
223 AM EDT MON JUL 13 2015
.SYNOPSIS...
UPPER LEVEL DISTURBANCES IN NORTHWEST FLOW THROUGH WEDNESDAY. WEAK
RIDGING ALOFT THURSDAY.
&&
.NEAR TERM /THROUGH TODAY/...
800 PM UPDATE...
INCREASED POPS TONIGHT FROM THE C LOWLANDS AND ESPECIALLY INTO THE
N LOWLANDS/MTNS. A WEAK LOW PRESSURE SYS OVER OH WILL DRIFT SE
INTO THE AREA OVERNIGHT. THIS COMBINED WITH SOME MID LEVEL LIFT
OVER THE AREA SHOULD ALLOW SHRA INCREASE IN COVERAGE THIS AFTER
MIDNIGHT. AS THIS SYS SPIRALS INTO THE AREA...EXPECT LOW CIGS TO
DEVELOP ALONG WITH PATCHY FG.
PREVIOUS DISCUSSION BELOW...
LATEST SATELLITE IMAGERY DEPICTS A RATHER CHAOTIC IMAGE OVER THE
MIDDLE ATLANTIC STATES THIS AFTERNOON...WITH SEVERAL FEATURES OF
NOTE. ACROSS CENTRAL AND EASTERN OHIO THERE IS A FAIRLY WELL
DEFINED SHORTWAVE KICKING OFF SHOWER ACTIVITY ACROSS NORTHEASTERN
OHIO. SKIES HAVE STARTED TO CLEAR SOME ACROSS CENTRAL AND EASTERN
KY...IN THE WAKE OF MCS WHICH MOVED THROUGH THIS MORNING. SEVERAL
OUTFLOW BOUNDARIES CAN BE SEEN IN EASTERN TN AND SOUTHERN KY AS
WELL. THESE HELPING TO KICK OFF CONVECTION. ACROSS WEST VIRGINIA A
SOLID MID DECK OF BLOW CLOUDS HAVE IMPEDED DAYTIME HEATING. THUS
THERE IS A LACK OF CONVECTION INITIATION SO FAR. HOWEVER...BL
HEATING ACROSS THE ELEVATED TERRAIN ALLOWING SOME CU TO FORM.
LATEST SHORT TERM MODELS HAVE BEEN SLOW TO CATCH ON WITH ALL OF
THESE SMALLER SCALE FEATURES. HOWEVER...LATEST RUNS SEEM TO SHOW A
TREND THAT PRECIPITATION SHOULD REMAIN SUPPRESSED FOR THE VERY NEAR
TERM WITH THE RUC AND HRRR IN GENERAL AGREEMENT. AS SHORTWAVE TRACKS
ACROSS THE NORTHERN TIER THIS EVENING...RAMPS POPS BACK UP. FOR
MONDAY...BROAD BUSHED POPS WITH AN EYE ON FEATURES THAT MAY TRACK
ACROSS IN NORTHWEST FLOW.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
GOING TO KEEP IT SHORT THIS MORNING DUE TO OTHER PRESSING CONCERNS.
LAST OF THE UPPER LEVEL TROUGHS IN THE NORTHWEST FLOW DIPS INTO THE
CENTRAL APPALACHIANS KEEPING THE THREAT FOR ACTIVE WEATHER GOING
THROUGH TUESDAY NIGHT AND ENDING WEDNESDAY. SPC DAY 2 OUTLOOK IS
LARGELY UNCHANGED WITH THE THREAT FOR SEVERE WEATHER PRIMARILY OVER
THE SOUTHERN TWO THIRDS OF THE FORECAST AREA. WITH WIND BEING THE
MAIN DRIVER. THE ACTIVE PATTERN WARRANT LIKELY POPS FOR THE BULK OF
TUESDAY INTO TUESDAY NIGHT...EVEN THOUGH IT WILL BE DIFFICULT TO
DETERMINE CONVECTIVE INITIATION AND TIMING.
PATTERN FINALLY TRANSITIONS TO MORE RIDGING ALOFT WEDNESDAY NIGHT
AND THURSDAY WITH HIGH PRESSURE INFLUENCES FROM THE NORTH AT THE
SURFACE. THURSDAY WILL LIKELY BREAK THE CONSECUTIVE DAYS WITH
PRECIPITATION STREAK IF NOT WEDNESDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
FOR WEDNESDAY...THE AREA WILL STILL BE UNDER THE INFLUENCE OF A
BROAD UPPER LEVEL TROUGH AND NORTHWEST FLOW...KEEPING THE AREA UNDER
CHANCES FOR ADDITIONAL SHOWERS AND THUNDERSTORMS LESS NUMEROUS THAN
THE PREVIOUS DAYS...AT LEAST THROUGH WEDNESDAY NIGHT. EXPECT A LULL
IN RAINFALL ACTIVITY THURSDAY. UPPER LEVEL FLOW FLATTENS ON FRIDAY.
MODELS DEVELOP A DEEP UPPER LEVEL RIDGE THAT SHOULD BRING SUBSIDENCE
AND RELATED WIDESPREAD DRIER CONDITIONS TO THE AREA SATURDAY NIGHT
THROUGH THE BEGINNING OF NEXT WEEK.
WENT WITH WPC FOR TEMPERATURES THROUGH THE PERIOD.
&&
.AVIATION /07Z MONDAY THROUGH FRIDAY/...
06Z MONDAY THRU 06Z TUESDAY...
AN ORGANIZED AREA OF SHOWERS AND STORMS WILL CROSS THE EASTERN
PORTION OF THE AREA 06Z TO 12Z...AFFECTING MAINLY CKB...EKN...AND
BKW.
LOOK FOR MVFR TO IFR IN THE ORGANIZED AREA OF SHOWERS...THEN IFR
CEILINGS AND VSBY DEVELOPING BEHIND THE SHOWERS
OVERNIGHT...AFFECTING ALL MAJOR TERMINALS. A RETURN TO VFR
CONDITIONS BY AROUND 15Z...WITH PERHAPS A BRIEF PERIOD OF MVFR
CIGS IN THE TRANSITION. LOOK FOR ANOTHER ORGANIZED AREA OF
SHRA/TSRA...WITH MVFR TO LOCALLY IFR CONDITIONS...TO RAPIDLY CROSS
THE AREA FROM NORTHWEST TO SOUTHEAST IN THE AFTN AND EVE HRS. SOME
OF THESE WILL BE STRONG TO SVR BUT AT THIS DISTANCE.
AFTER THIS BATCH OF SHOWERS...LOOK FOR IFR TO RETURN IN LOW CLOUDS
AND VSBY AFTER 02Z.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z TUESDAY...
FORECAST CONFIDENCE:MEDIUM.
ALTERNATE SCENARIOS: EXTENT OF LOW STRATUS AND FG IN QUESTION.
AFTER 06Z TUESDAY...IFR CONDITIONS POSSIBLE IN THUNDERSTORMS EACH
DAY.
&&
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KMC/ARJ/26
NEAR TERM...KMC/30
SHORT TERM...26
LONG TERM...JB/ARJ
AVIATION...JMV
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
158 AM EDT MON JUL 13 2015
.SYNOPSIS...
UPPER LEVEL DISTURBANCES WILL CROSS THE AREA IN NORTHWEST FLOW
THRU NEXT WEEK...KEEPING UNSETTLED CONDITIONS IN PLACE. AN UPPER
LEVEL RIDGE MAY DEVELOP BY THE END OF NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
800 PM UPDATE...
INCREASED POPS TONIGHT FROM THE C LOWLANDS AND ESPECIALLY INTO THE
N LOWLANDS/MTNS. A WEAK LOW PRESSURE SYS OVER OH WILL DRIFT SE
INTO THE AREA OVERNIGHT. THIS COMBINED WITH SOME MID LEVEL LIFT
OVER THE AREA SHOULD ALLOW SHRA INCREASE IN COVERAGE THIS AFTER
MIDNIGHT. AS THIS SYS SPIRALS INTO THE AREA...EXPECT LOW CIGS TO
DEVELOP ALONG WITH PATCHY FG.
PREVIOUS DISCUSSION BELOW...
LATEST SATELLITE IMAGERY DEPICTS A RATHER CHAOTIC IMAGE OVER THE
MIDDLE ATLANTIC STATES THIS AFTERNOON...WITH SEVERAL FEATURES OF
NOTE. ACROSS CENTRAL AND EASTERN OHIO THERE IS A FAIRLY WELL
DEFINED SHORTWAVE KICKING OFF SHOWER ACTIVITY ACROSS NORTHEASTERN
OHIO. SKIES HAVE STARTED TO CLEAR SOME ACROSS CENTRAL AND EASTERN
KY...IN THE WAKE OF MCS WHICH MOVED THROUGH THIS MORNING. SEVERAL
OUTFLOW BOUNDARIES CAN BE SEEN IN EASTERN TN AND SOUTHERN KY AS
WELL. THESE HELPING TO KICK OFF CONVECTION. ACROSS WEST VIRGINIA A
SOLID MID DECK OF BLOW CLOUDS HAVE IMPEDED DAYTIME HEATING. THUS
THERE IS A LACK OF CONVECTION INITIATION SO FAR. HOWEVER...BL
HEATING ACROSS THE ELEVATED TERRAIN ALLOWING SOME CU TO FORM.
LATEST SHORT TERM MODELS HAVE BEEN SLOW TO CATCH ON WITH ALL OF
THESE SMALLER SCALE FEATURES. HOWEVER...LATEST RUNS SEEM TO SHOW A
TREND THAT PRECIPITATION SHOULD REMAIN SUPPRESSED FOR THE VERY NEAR
TERM WITH THE RUC AND HRRR IN GENERAL AGREEMENT. AS SHORTWAVE TRACKS
ACROSS THE NORTHERN TIER THIS EVENING...RAMPS POPS BACK UP. FOR
MONDAY...BROAD BUSHED POPS WITH AN EYE ON FEATURES THAT MAY TRACK
ACROSS IN NORTHWEST FLOW.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
THE GFS AND ECMWF MODELS ARE IN BETTER AGREEMENT WITH AN H500
SHORTWAVE UNDER NORTHWEST FLOW CROSSING THE AREA MONDAY NIGHT. THE
NAM LOOKS ABOUT 6-12 HOURS SLOWER BRINGING MOST OF THE ENERGY BY 12Z
TUESDAY. PREFER THE CONSENSUS FROM GFS/ECMWF. THEREFORE...EXPECT
THIS SHORTWAVE TO BRING GOOD CHANCES FOR SHOWERS OR THUNDERSTORMS...
SOME WITH PERIODS OF HEAVY RAIN INTO EARLY TUESDAY.
MODELS ARE IN AGREEMENT WITH A STRONGER TROUGH/LOW PRESSURE SYSTEM
TO DROP FROM THE GREAT LAKES REGION...SOUTHEAST ACROSS PA AND
PORTIONS OF NORTHERN WV TUESDAY NIGHT. ADDITIONAL ROUNDS FOR SHOWERS
AND THUNDERSTORMS WITH HEAVY RAIN WILL BE POSSIBLE. HAVE CODED
LIKELY POPS FOR BOTH DAYS WITH EACH SYSTEM.
CONCERNS FOR FLOODING CONTINUES DURING THIS PERIOD...AND WILL
CONTINUE MENTION IN THE HAZARDOUS WEATHER OUTLOOK. TEMPERATURES WILL
CONTINUE TO BE MODERATE WITH CLOUDS AND SHOWERS...BUT ALSO REMAINING
QUITE HUMID. MINOR CHANGES MADE TO PREVIOUS TEMPERATURES.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
FOR WEDNESDAY...THE AREA WILL STILL BE UNDER THE INFLUENCE OF A
BROAD UPPER LEVEL TROUGH AND NORTHWEST FLOW...KEEPING THE AREA UNDER
CHANCES FOR ADDITIONAL SHOWERS AND THUNDERSTORMS LESS NUMEROUS THAN
THE PREVIOUS DAYS...AT LEAST THROUGH WEDNESDAY NIGHT. EXPECT A LULL
IN RAINFALL ACTIVITY THURSDAY. UPPER LEVEL FLOW FLATTENS ON FRIDAY.
MODELS DEVELOP A DEEP UPPER LEVEL RIDGE THAT SHOULD BRING SUBSIDENCE
AND RELATED WIDESPREAD DRIER CONDITIONS TO THE AREA SATURDAY NIGHT
THROUGH THE BEGINNING OF NEXT WEEK.
WENT WITH WPC FOR TEMPERATURES THROUGH THE PERIOD.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
06Z MONDAY THRU 06Z TUESDAY...
AN ORGANIZED AREA OF SHOWERS AND STORMS WILL CROSS THE EASTERN
PORTION OF THE AREA 06Z TO 12Z...AFFECTING MAINLY CKB...EKN...AND
BKW.
LOOK FOR MVFR TO IFR IN THE ORGANIZED AREA OF SHOWERS...THEN IFR
CEILINGS AND VSBY DEVELOPING BEHIND THE SHOWERS
OVERNIGHT...AFFECTING ALL MAJOR TERMINALS. A RETURN TO VFR
CONDITIONS BY AROUND 15Z...WITH PERHAPS A BRIEF PERIOD OF MVFR
CIGS IN THE TRANSITION. LOOK FOR ANOTHER ORGANIZED AREA OF
SHRA/TSRA...WITH MVFR TO LOCALLY IFR CONDITIONS...TO RAPIDLY CROSS
THE AREA FROM NORTHWEST TO SOUTHEAST IN THE AFTN AND EVE HRS. SOME
OF THESE WILL BE STRONG TO SVR BUT AT THIS DISTANCE.
AFTER THIS BATCH OF SHOWERS...LOOK FOR IFR TO RETURN IN LOW CLOUDS
AND VSBY AFTER 02Z.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z TUESDAY...
FORECAST CONFIDENCE:MEDIUM.
ALTERNATE SCENARIOS: EXTENT OF LOW STRATUS AND FG IN QUESTION.
AFTER 06Z TUESDAY...IFR CONDITIONS POSSIBLE IN THUNDERSTORMS EACH
DAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KMC/ARJ
NEAR TERM...KMC/30
SHORT TERM...ARJ
LONG TERM...JB/ARJ
AVIATION...JMV
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1158 PM EDT TUE JUL 14 2015
.SYNOPSIS...
A COMPLEX FRONTAL SYSTEM WILL MOVE THROUGH THE AREA OVERNIGHT.
HIGH PRESSURE BUILDING SOUTHEAST FROM THE GREAT LAKES WILL BRING A
DRIER WEATHER PATTERN DURING THE SECOND HALF OF THE WEEK BEFORE
INCREASING HEAT AND HUMIDITY MAKE A RETURN FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
MESO ANAL AS OF 9 PM SHOWS A LOW OVER LAKE ERIE WITH A VERY
COMPLEX FRONTAL SYSTEM IN PLACE OVER THE REGION. LOW PRESSURE IS
BEGINNING TO FORM OVER THE SOUTH-CENTRAL MOUNTAINS ALONG WHAT WAS
THE WARM FRONT...AND IT SEEMS TO BE THE FOCUS MECHANISM FOR
CONVECTION THAT CONTINUES TO FIRE EVEN AT THIS HOUR.
THE HRRR KEEPS US ACTIVE THROUGH AT LEAST MIDNIGHT BEFORE
ACTIVITY BEGINS TO WANE AS THE FRONTAL SYSTEM FINALLY STARTS TO
SETTLE OFF TO THE SOUTH AND EAST.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
AS THE COLD FRONT COMES THROUGH IT SHOULD BRING DRIER AIR AND MOVE
MOST OF THE STORMS TO THE SOUTHEAST. WILL LINGER HIGH CHC POPS
INTO THE MORNING ON WEDNESDAY FOR THE FAR SERN COS...THOUGH.
THE CURRENT LOW TRACK SOUTHWARD...MOVING THE FRONT THROUGH WEST
VIRGINIA. WIDESPREAD SHOWERS AND THUNDERSTORMS REMAIN POSSIBLE
TONIGHT INTO THE EARLY WEDNESDAY. IN THE WAKE OF THE FRONT EXPECT
DRIER CONDITIONS WHICH COULD LEAD TO PATCHY EARLY MORNING FOG.
IMPROVEMENT IS EXPECTED OVER MOST OF THE AREA LATE WED MORNING AND
THROUGH THE AFTERNOON. HIGHS SHOULD RECOVER CLOSE TO 80F IN THE
S...BUT KEEP AT OR BELOW 70F IN THE FAR NW.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
SHOWERS WILL END OVER SOUTHERN/EASTERN AREAS BY 00Z THURSDAY AS
THE COLD FRONT PUSHES SEWD TOWARD THE MID ATLC COAST. BEHIND THE
FRONT...A LARGE AREA OF BELOW NORMAL PW AIR WILL OVERSPREAD THE
NORTHEAST AND MID ATLANTIC STATES FROM WED NGT THROUGH
THURSDAY...ACCOMPANIED BY AN EXPANSIVE AREA OF HIGH PRESSURE
MIGRATING EWD FROM SERN CANADA INTO THE N. ATLC OCEAN...WHICH
WILL ENSURE DRY WX DURING THIS TIME. MUCH OF FRIDAY ALSO LOOKS DRY
WITH A LOW RISK OF A LATE DAY SHOWER/TSTM ACROSS THE FAR WRN/NWRN
ALLEGHENY MTNS. WED/THU NIGHTS WILL BE REFRESHINGLY COOL WITH LOWS
IN THE MID 40S TO LOW 50S AND VALLEY FOG ACROSS THE NRN TIER.
500MB HEIGHTS SHOULD STEADILY REBOUND THROUGH THE WEEKEND WITH
VERY WARM/HOT AND HUMID CONDITIONS FORECAST INTO EARLY NEXT WEEK.
CENTRAL PA IS CURRENTLY NEAR/AT THE HOTTEST TIME OF THE YEAR
/JULY 11-20/ BASED ON THE MOST RECENT 30-YEAR CLIMATE NORMALS.
HEAT INDEX VALUES MAY APPROACH 100F OVER THE LWR SUSQ VALLEY SUN-
MON WITH GUIDANCE SHOWING HIGHS AROUND 90F.
THE UPSTREAM FLOW ALOFT IS FCST TO TREND FROM QUASI-ZONAL ON THE
NRN PERIPHERY OF SRN PLAINS RIDGE...FROM THE MIDWEST THROUGH THE
GREAT LAKES...EVENTUALLY TOWARD MORE OF A WEST-NORTHWEST FLOW WITH
GENERAL TROUGHING LKLY TO CONTINUE OVER THE EASTERN QUARTER OF
NOAM. NRN STREAM S/WVS MOVING INTO THE AREA FROM THE WNW...ALONG
WITH DIURNAL INSTABILITY...MAY BE A FOCUS FOR SHOWERS/TSTMS SAT-
SUN. A BETTER FOCUS FOR PCPN SHOULD EVOLVE INTO THE MON-TUE TIME
FRAME AS A FRONTAL BOUNDARY PUSHES SEWD FROM THE GREAT LAKES.
&&
.AVIATION /04Z WEDNESDAY THROUGH SUNDAY/...
A COLD FRONT MOVING SE ACROSS THE REGION WILL BRING NUMEROUS SHRA
AND TSRA TO THE AREA THRU ARND 06Z...MAINLY FROM KUNV SOUTH AND
EASTWARD. BRIEF IFR REDUCTIONS ARE POSSIBLE IN THIS AREA BTWN
04Z-07Z.
AS THE COLD FRONT MOVES EAST OF THE AREA...FOCUS LATE TONIGHT
WILL SHIFT TOWARD THE LIKELIHOOD OF LOW CIGS ACROSS THE W MTNS.
RESIDUAL LOW LVL MOISTURE ASCENDING THE ALLEGHENY MTNS WILL LIKELY
RESULT IN IFR CIGS AT KBFD AND KJST LATE TONIGHT. A LIGHT
DOWNSLOPING NW FLOW SHOULD YIELD MORE FAVORABLE CONDS FURTHER
EAST...WITH MVFR CIGS/VSBYS LIKELY LATE TONIGHT ACROSS MOST
CENTRAL PA AIRFIELDS.
LOW CIGS COULD LINGER UNTIL ARND MIDDAY WED ARND KJST. OTHERWISE...EXPECT
IMPROVING FLYING CONDS...AS NORTHERLY FLOW DRAWS DRIER AIR INTO
THE REGION. WIDESPREAD VFR CONDS EXPECTED EVERYWHERE WED AFTN.
OUTLOOK...
THU...NO SIG WX EXPECTED.
FRI...ISOLD PM TSRA IMPACTS POSS W MTNS.
SAT-SUN...SCT PM TSRA IMPACTS POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...DANGELO/CERU
LONG TERM...STEINBUGL
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1036 PM EDT TUE JUL 14 2015
.SYNOPSIS...
A COMPLEX FRONTAL SYSTEM WILL MOVE THROUGH THE AREA OVERNIGHT.
HIGH PRESSURE BUILDING SOUTHEAST FROM THE GREAT LAKES WILL BRING A
DRIER WEATHER PATTERN DURING THE SECOND HALF OF THE WEEK BEFORE
INCREASING HEAT AND HUMIDITY MAKE A RETURN FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
MESO ANAL AS OF 9 PM SHOWS A LOW OVER LAKE ERIE WITH A VERY
COMPLEX FRONTAL SYSTEM IN PLACE OVER THE REGION. LOW PRESSURE IS
BEGINNING TO FORM OVER THE SOUTH-CENTRAL MOUNTAINS ALONG WHAT WAS
THE WARM FRONT...AND IT SEEMS TO BE THE FOCUS MECHANISM FOR
CONVECTION THAT CONTINUES TO FIRE EVEN AT THIS HOUR.
THE HRRR KEEPS US ACTIVE THROUGH AT LEAST MIDNIGHT BEFORE
ACTIVITY BEGINS TO WANE AS THE FRONTAL SYSTEM FINALLY STARTS TO
SETTLE OFF TO THE SOUTH AND EAST.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
AS THE COLD FRONT COMES THROUGH IT SHOULD BRING DRIER AIR AND MOVE
MOST OF THE STORMS TO THE SOUTHEAST. WILL LINGER HIGH CHC POPS
INTO THE MORNING ON WEDNESDAY FOR THE FAR SERN COS...THOUGH.
THE CURRENT LOW TRACK SOUTHWARD...MOVING THE FRONT THROUGH WEST
VIRGINIA. WIDESPREAD SHOWERS AND THUNDERSTORMS REMAIN POSSIBLE
TONIGHT INTO THE EARLY WEDNESDAY. IN THE WAKE OF THE FRONT EXPECT
DRIER CONDITIONS WHICH COULD LEAD TO PATCHY EARLY MORNING FOG.
IMPROVEMENT IS EXPECTED OVER MOST OF THE AREA LATE WED MORNING AND
THROUGH THE AFTERNOON. HIGHS SHOULD RECOVER CLOSE TO 80F IN THE
S...BUT KEEP AT OR BELOW 70F IN THE FAR NW.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
SHOWERS WILL END OVER SOUTHERN/EASTERN AREAS BY 00Z THURSDAY AS
THE COLD FRONT PUSHES SEWD TOWARD THE MID ATLC COAST. BEHIND THE
FRONT...A LARGE AREA OF BELOW NORMAL PW AIR WILL OVERSPREAD THE
NORTHEAST AND MID ATLANTIC STATES FROM WED NGT THROUGH
THURSDAY...ACCOMPANIED BY AN EXPANSIVE AREA OF HIGH PRESSURE
MIGRATING EWD FROM SERN CANADA INTO THE N. ATLC OCEAN...WHICH
WILL ENSURE DRY WX DURING THIS TIME. MUCH OF FRIDAY ALSO LOOKS DRY
WITH A LOW RISK OF A LATE DAY SHOWER/TSTM ACROSS THE FAR WRN/NWRN
ALLEGHENY MTNS. WED/THU NIGHTS WILL BE REFRESHINGLY COOL WITH LOWS
IN THE MID 40S TO LOW 50S AND VALLEY FOG ACROSS THE NRN TIER.
500MB HEIGHTS SHOULD STEADILY REBOUND THROUGH THE WEEKEND WITH
VERY WARM/HOT AND HUMID CONDITIONS FORECAST INTO EARLY NEXT WEEK.
CENTRAL PA IS CURRENTLY NEAR/AT THE HOTTEST TIME OF THE YEAR
/JULY 11-20/ BASED ON THE MOST RECENT 30-YEAR CLIMATE NORMALS.
HEAT INDEX VALUES MAY APPROACH 100F OVER THE LWR SUSQ VALLEY SUN-
MON WITH GUIDANCE SHOWING HIGHS AROUND 90F.
THE UPSTREAM FLOW ALOFT IS FCST TO TREND FROM QUASI-ZONAL ON THE
NRN PERIPHERY OF SRN PLAINS RIDGE...FROM THE MIDWEST THROUGH THE
GREAT LAKES...EVENTUALLY TOWARD MORE OF A WEST-NORTHWEST FLOW WITH
GENERAL TROUGHING LKLY TO CONTINUE OVER THE EASTERN QUARTER OF
NOAM. NRN STREAM S/WVS MOVING INTO THE AREA FROM THE WNW...ALONG
WITH DIURNAL INSTABILITY...MAY BE A FOCUS FOR SHOWERS/TSTMS SAT-
SUN. A BETTER FOCUS FOR PCPN SHOULD EVOLVE INTO THE MON-TUE TIME
FRAME AS A FRONTAL BOUNDARY PUSHES SEWD FROM THE GREAT LAKES.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
A COLD FRONT MOVING SE ACROSS THE REGION WILL BRING NUMEROUS SHRA
AND TSRA TO THE AREA THRU ARND 03Z...MAINLY NORTH AND WEST OF
KMDT. BRIEF IFR REDUCTIONS ARE POSSIBLE IN THIS AREA EARLY THIS
EVENING FROM PASSING SHRA/TSRA...DESPITE PREVAILING VFR CONDS OVR
MOST OF THE REGION EARLY THIS EVENING.
AS THE COLD FRONT MOVES EAST OF THE AREA...FOCUS LATE TONIGHT
WILL SHIFT TOWARD THE POSSIBILITY OF LOW CIGS ACROSS THE W MTNS.
RESIDUAL LOW LVL MOISTURE ASCENDING THE ALLEGHENY MTNS WILL LIKELY
RESULT IN IFR CIGS AT KBFD AND KJST LATE TONIGHT. A LIGHT
DOWNSLOPING NW FLOW SHOULD YIELD MORE FAVORABLE CONDS FURTHER
EAST...WITH MVFR CIGS/VSBYS LIKELY LATE TONIGHT ACROSS MOST
CENTRAL PA AIRFIELDS.
LOW CIGS COULD LINGER UNTIL ARND MIDDAY WED ARND KJST. OTHERWISE...EXPECT
IMPROVING FLYING CONDS...AS NORTHERLY FLOW DRAWS DRIER AIR INTO
THE REGION. WIDESPREAD VFR CONDS EXPECTED EVERYWHERE WED AFTN.
OUTLOOK...
THU...NO SIG WX EXPECTED.
FRI...ISOLD PM TSRA IMPACTS POSS W MTNS.
SAT-SUN...SCT PM TSRA IMPACTS POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...DANGELO/CERU
LONG TERM...STEINBUGL
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1023 PM EDT TUE JUL 14 2015
.SYNOPSIS...
A COMPLEX FRONTAL SYSTEM WILL MOVE THROUGH THE AREA OVERNIGHT.
HIGH PRESSURE BUILDING SOUTHEAST FROM THE GREAT LAKES WILL BRING A
DRIER WEATHER PATTERN DURING THE SECOND HALF OF THE WEEK BEFORE
INCREASING HEAT AND HUMIDITY MAKE A RETURN FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
MESO ANAL AS OF 9 PM SHOWS A LOW OVER LAKE ERIE WITH A VERY
COMPLEX FRONTAL SYSTEM IN PLACE OVER THE REGION. LOW PRESSURE IS
BEGINNING TO FORM OVER THE SOUTH-CENTRAL MOUNTAINS ALONG WHAT WAS
THE WARM FRONT...AND IT SEEMS TO BE THE FOCUS MECHANISM FOR
CONVECTION THAT CONVECTION CONTINUES TO FIRE EVEN AT THIS HOUR.
THE HRRR KEEPS US ACTIVE THROUGH AT LEAST MIDNIGHT BEFORE
ACTIVITY BEGINS TO WANE AS THE FRONTAL SYSTEM FINALLY STARTS TO
SETTLE OFF TO THE SOUTH AND EAST.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
AS THE COLD FRONT COMES THROUGH IT SHOULD BRING DRIER AIR AND MOVE
MOST OF THE STORMS TO THE SOUTHEAST. WILL LINGER HIGH CHC POPS
INTO THE MORNING ON WEDNESDAY FOR THE FAR SERN COS...THOUGH.
THE CURRENT LOW TRACK SOUTHWARD...MOVING THE FRONT THROUGH WEST
VIRGINIA. WIDESPREAD SHOWERS AND THUNDERSTORMS REMAIN POSSIBLE
TONIGHT INTO THE EARLY WEDNESDAY. IN THE WAKE OF THE FRONT EXPECT
DRIER CONDITIONS WHICH COULD LEAD TO PATCHY EARLY MORNING FOG.
IMPROVEMENT IS EXPECTED OVER MOST OF THE AREA LATE WED MORNING AND
THROUGH THE AFTERNOON. HIGHS SHOULD RECOVER CLOSE TO 80F IN THE
S...BUT KEEP AT OR BELOW 70F IN THE FAR NW.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
SHOWERS WILL END OVER SOUTHERN/EASTERN AREAS BY 00Z THURSDAY AS
THE COLD FRONT PUSHES SEWD TOWARD THE MID ATLC COAST. BEHIND THE
FRONT...A LARGE AREA OF BELOW NORMAL PW AIR WILL OVERSPREAD THE
NORTHEAST AND MID ATLANTIC STATES FROM WED NGT THROUGH
THURSDAY...ACCOMPANIED BY AN EXPANSIVE AREA OF HIGH PRESSURE
MIGRATING EWD FROM SERN CANADA INTO THE N. ATLC OCEAN...WHICH
WILL ENSURE DRY WX DURING THIS TIME. MUCH OF FRIDAY ALSO LOOKS DRY
WITH A LOW RISK OF A LATE DAY SHOWER/TSTM ACROSS THE FAR WRN/NWRN
ALLEGHENY MTNS. WED/THU NIGHTS WILL BE REFRESHINGLY COOL WITH LOWS
IN THE MID 40S TO LOW 50S AND VALLEY FOG ACROSS THE NRN TIER.
500MB HEIGHTS SHOULD STEADILY REBOUND THROUGH THE WEEKEND WITH
VERY WARM/HOT AND HUMID CONDITIONS FORECAST INTO EARLY NEXT WEEK.
CENTRAL PA IS CURRENTLY NEAR/AT THE HOTTEST TIME OF THE YEAR
/JULY 11-20/ BASED ON THE MOST RECENT 30-YEAR CLIMATE NORMALS.
HEAT INDEX VALUES MAY APPROACH 100F OVER THE LWR SUSQ VALLEY SUN-
MON WITH GUIDANCE SHOWING HIGHS AROUND 90F.
THE UPSTREAM FLOW ALOFT IS FCST TO TREND FROM QUASI-ZONAL ON THE
NRN PERIPHERY OF SRN PLAINS RIDGE...FROM THE MIDWEST THROUGH THE
GREAT LAKES...EVENTUALLY TOWARD MORE OF A WEST-NORTHWEST FLOW WITH
GENERAL TROUGHING LKLY TO CONTINUE OVER THE EASTERN QUARTER OF
NOAM. NRN STREAM S/WVS MOVING INTO THE AREA FROM THE WNW...ALONG
WITH DIURNAL INSTABILITY...MAY BE A FOCUS FOR SHOWERS/TSTMS SAT-
SUN. A BETTER FOCUS FOR PCPN SHOULD EVOLVE INTO THE MON-TUE TIME
FRAME AS A FRONTAL BOUNDARY PUSHES SEWD FROM THE GREAT LAKES.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
A COLD FRONT MOVING SE ACROSS THE REGION WILL BRING NUMEROUS SHRA
AND TSRA TO THE AREA THRU ARND 03Z...MAINLY NORTH AND WEST OF
KMDT. BRIEF IFR REDUCTIONS ARE POSSIBLE IN THIS AREA EARLY THIS
EVENING FROM PASSING SHRA/TSRA...DESPITE PREVAILING VFR CONDS OVR
MOST OF THE REGION EARLY THIS EVENING.
AS THE COLD FRONT MOVES EAST OF THE AREA...FOCUS LATE TONIGHT
WILL SHIFT TOWARD THE POSSIBILITY OF LOW CIGS ACROSS THE W MTNS.
RESIDUAL LOW LVL MOISTURE ASCENDING THE ALLEGHENY MTNS WILL LIKELY
RESULT IN IFR CIGS AT KBFD AND KJST LATE TONIGHT. A LIGHT
DOWNSLOPING NW FLOW SHOULD YIELD MORE FAVORABLE CONDS FURTHER
EAST...WITH MVFR CIGS/VSBYS LIKELY LATE TONIGHT ACROSS MOST
CENTRAL PA AIRFIELDS.
LOW CIGS COULD LINGER UNTIL ARND MIDDAY WED ARND KJST. OTHERWISE...EXPECT
IMPROVING FLYING CONDS...AS NORTHERLY FLOW DRAWS DRIER AIR INTO
THE REGION. WIDESPREAD VFR CONDS EXPECTED EVERYWHERE WED AFTN.
OUTLOOK...
THU...NO SIG WX EXPECTED.
FRI...ISOLD PM TSRA IMPACTS POSS W MTNS.
SAT-SUN...SCT PM TSRA IMPACTS POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...DANGELO/CERU
LONG TERM...STEINBUGL
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
752 PM EDT TUE JUL 14 2015
.SYNOPSIS...
A COMPLEX FRONTAL SYSTEM WILL MOVE THROUGH THE AREA OVERNIGHT.
HIGH PRESSURE BUILDING SOUTHEAST FROM THE GREAT LAKES WILL BRING A
DRIER WEATHER PATTERN DURING THE SECOND HALF OF THE WEEK BEFORE
INCREASING HEAT AND HUMIDITY MAKE A RETURN FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
MESO ANAL AS OF 7 PM SHOWS A LOW OVER LAKE ERIE WITH A VERY
COMPLEX FRONTAL SYSTEM IN PLACE OVER THE REGION. CONVECTION HAS
MADE THE WARM FRONT HARD TO FIND BUT IT LOOKS TO BE ROUGHLY IN THE
NEIGHBORHOOD OF I-80...WITH THE COLD FRONT/OCCLUSION FROM NW PA
DOWN INTO OHIO.
RADAR IS VERY ACTIVE WITH THE BEST CLUSTERING OF STORMS EXTENDING
FROM THE SOUTHERN LAUREL HIGHLANDS UP THROUGH POTTER AND TIOGA
COUNTIES. THE HRRR KEEPS US ACTIVE THROUGH AT LEAST MIDNIGHT
BEFORE ACTIVITY BEGINS TO WANE WITH THE PASSAGE OF THE FRONTAL
SYSTEM.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
AS THE COLD FRONT COMES THROUGH IT SHOULD BRING DRIER AIR AND MOVE
MOST OF THE STORMS TO THE SOUTHEAST. WILL LINGER HIGH CHC POPS
INTO THE MORNING ON WEDNESDAY FOR THE FAR SERN COS...THOUGH.
THE CURRENT LOW TRACK SOUTHWARD...MOVING THE FRONT THROUGH WEST
VIRGINIA. WIDESPREAD SHOWERS AND THUNDERSTORMS REMAIN POSSIBLE
TONIGHT INTO THE EARLY WEDNESDAY. IN THE WAKE OF THE FRONT EXPECT
DRIER CONDITIONS WHICH COULD LEAD TO PATCHY EARLY MORNING FOG.
IMPROVEMENT IS EXPECTED OVER MOST OF THE AREA LATE WED MORNING AND
THROUGH THE AFTERNOON. HIGHS SHOULD RECOVER CLOSE TO 80F IN THE
S...BUT KEEP AT OR BELOW 70F IN THE FAR NW.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
SHOWERS WILL END OVER SOUTHERN/EASTERN AREAS BY 00Z THURSDAY AS
THE COLD FRONT PUSHES SEWD TOWARD THE MID ATLC COAST. BEHIND THE
FRONT...A LARGE AREA OF BELOW NORMAL PW AIR WILL OVERSPREAD THE
NORTHEAST AND MID ATLANTIC STATES FROM WED NGT THROUGH
THURSDAY...ACCOMPANIED BY AN EXPANSIVE AREA OF HIGH PRESSURE
MIGRATING EWD FROM SERN CANADA INTO THE N. ATLC OCEAN...WHICH
WILL ENSURE DRY WX DURING THIS TIME. MUCH OF FRIDAY ALSO LOOKS DRY
WITH A LOW RISK OF A LATE DAY SHOWER/TSTM ACROSS THE FAR WRN/NWRN
ALLEGHENY MTNS. WED/THU NIGHTS WILL BE REFRESHINGLY COOL WITH LOWS
IN THE MID 40S TO LOW 50S AND VALLEY FOG ACROSS THE NRN TIER.
500MB HEIGHTS SHOULD STEADILY REBOUND THROUGH THE WEEKEND WITH
VERY WARM/HOT AND HUMID CONDITIONS FORECAST INTO EARLY NEXT WEEK.
CENTRAL PA IS CURRENTLY NEAR/AT THE HOTTEST TIME OF THE YEAR
/JULY 11-20/ BASED ON THE MOST RECENT 30-YEAR CLIMATE NORMALS.
HEAT INDEX VALUES MAY APPROACH 100F OVER THE LWR SUSQ VALLEY SUN-
MON WITH GUIDANCE SHOWING HIGHS AROUND 90F.
THE UPSTREAM FLOW ALOFT IS FCST TO TREND FROM QUASI-ZONAL ON THE
NRN PERIPHERY OF SRN PLAINS RIDGE...FROM THE MIDWEST THROUGH THE
GREAT LAKES...EVENTUALLY TOWARD MORE OF A WEST-NORTHWEST FLOW WITH
GENERAL TROUGHING LKLY TO CONTINUE OVER THE EASTERN QUARTER OF
NOAM. NRN STREAM S/WVS MOVING INTO THE AREA FROM THE WNW...ALONG
WITH DIURNAL INSTABILITY...MAY BE A FOCUS FOR SHOWERS/TSTMS SAT-
SUN. A BETTER FOCUS FOR PCPN SHOULD EVOLVE INTO THE MON-TUE TIME
FRAME AS A FRONTAL BOUNDARY PUSHES SEWD FROM THE GREAT LAKES.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
A COLD FRONT MOVING THROUGH THE REGION WILL BRING NUMEROUS SHRA
AND TSRA TO THE AREA THIS EVENING BETWEEN 21Z AND 03Z. ALTHOUGH
VFR CONDS WILL PREDOMINATE...BRIEF VIS REDUCTIONS ARE LIKELY WITH
PASSING TSRA. AS COLD FRONT MOVES EAST OF THE AREA...FOCUS LATE
TONIGHT WILL SHIFT TOWARD THE POSSIBILITY OF LOW CIGS ACROSS THE
W MTNS. RESIDUAL LOW LVL MOISTURE ASCENDING THE ALLEGHENY MTNS
WILL LIKELY RESULT IN IFR CIGS AT KBFD AND KJST LATE TONIGHT. A
LIGHT DOWNSLOPING NW FLOW WILL YIELD MORE FAVORABLE CONDS TO THE
EAST WITH MVFR CIGS/VSBYS LIKELY.
LOW CIGS COULD LINGER UNTIL ARND MIDDAY WED ARND KJST. OTHERWISE...EXPECT
IMPROVING CONDS WED AS NORTHERLY FLOW DRAWS DRIER AIR INTO THE
REGION. WIDESPREAD VFR CONDS EXPECTED EVERYWHERE WED AFTN.
OUTLOOK...
WED...EARLY AM LOW CIGS LIKELY ACROSS THE W MTNS.
THU-FRI...NO SIG WX EXPECTED.
SAT...SCT PM TSRA IMPACTS POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LA CORTE/CERU
NEAR TERM...DANGELO/LA CORTE/CERU
SHORT TERM...DANGELO/CERU
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/TYBURSKI
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
758 PM CDT TUE JUL 14 2015
.UPDATE...
UPDATE TO REMOVE SEVERE THUNDERSTORM AND FLASH FLOOD WATCHES FROM
THE MID SOUTH.
&&
.DISCUSSION...
THE POWERFUL MESOSCALE CONVECTIVE COMPLEX (MCS) THAT MOVED ACROSS
THE MID SOUTH RESULTING IN WIDESPREAD WIND DAMAGE HAS FINALLY
EXITED TO THE SOUTHEAST AND INTO CENTRAL ALABAMA. THE RAIN COOLED
AIR HAS STABILIZED THE ATMOSPHERE THIS EVENING AND ANY LINGERING
STORMS SHOULD DIMINISH LATER THIS EVENING. MODELS CONTINUE TO
SUGGEST THAT THE ADDITIONAL SHOWERS AND THUNDERSTORMS MAY DEVELOP
ACROSS NORTHEAST PORTIONS OF THE REGION LATE TONIGHT. IT APPEARS
POSSIBLE AS THE AIRMASS ATTEMPTS TO RECOVER SOME...BUT THINK THAT
COVERAGE SHOULD REMAIN LOW. MAINTAINED SLIGHT CHANCE/LOW END
CHANCE POPS AFTER MIDNIGHT...BUT MAY NEED TO REASSESS LATER THIS
EVENING AS CONFIDENCE IN THIS OCCURRING CONTINUES TO DECREASE.
ALL THREATS FOR SEVERE WEATHER AND FLASH FLOODING ACROSS THE MID
SOUTH HAVE ENDED FOR TONIGHT AND THE LATEST HWO REFLECTS THIS
THINKING. PLEASE PASS ALONG ANY WIND DAMAGE REPORTS FROM EARLIER
STORMS...IT IS GREATLY APPRECIATED.
ADDITIONAL UPDATES WILL BE PROVIDED THROUGH THE EVENING AS
NECESSARY.
JLH
&&
.PREV DISCUSSION... /ISSUED 459 PM CDT TUE JUL 14 2015/
UPDATE...
UPDATE TO INCREASE POPS ACROSS MUCH OF THE REGION AND CLEAN UP
SEVERE THUNDERSTORM WATCH PRODUCTS.
DISCUSSION...
A FORWARD PROPAGATING MESOSCALE CONVECTIVE SYSTEM (MCS) IS
ADVANCING THROUGH SOUTHERN WEST TENNESSEE AND PORTIONS OF NORTH
MISSISSIPPI. THIS SYSTEM HAS HAD A HISTORY OF WIDESPREAD AND
SOMETIMES SIGNIFICANT WIND DAMAGE WITH WIND GUSTS IN EXCESS OF 70
MPH AT TIMES. THERE HAS ALSO BEEN TRAINING THUNDERSTORMS ACROSS
WEST TENNESSEE NEAR THE I-40 CORRIDOR WHERE LOW LEVEL CONVERGENCE
IS BECOMING MAXIMIZED. THIS REGION WILL BE AN AREA WHERE HEAVY
RAINFALL AND FLASH FLOODING WILL BECOME MORE OF AN ISSUE WITH TIME
THROUGH THIS EVENING.
CONVECTION SHOULD CONTINUE TO ADVANCE THROUGH EAST ARKANSAS AND
NORTH MISSISSIPPI THROUGH THE REMAINDER OF THIS EVENING AS THE
CONVECTIVE LINE MOVES INTO A STRONGLY UNSTABLE ENVIRONMENT
CHARACTERIZED BY MLCAPE VALUES IN EXCESS OF 3500 J/KG. ALSO...A
WELL ESTABLISHED COLD POOL WILL SUSTAIN STORM STRUCTURE AND
CONTINUED WIND DAMAGE POTENTIAL IS EXPECTED. STORM COVERAGE AND
INTENSITY SHOULD DIMINISH AREAWIDE AFTER MIDNIGHT.
UPDATED PRODUCTS HAVE BEEN SENT AND WILL BE UPDATED AS NEEDED
THROUGH THE EVENING.
JLH
&&
.PREV DISCUSSION... /ISSUED 344 PM CDT TUE JUL 14 2015/
DISCUSSION...
CURRENTLY... ANOTHER WARM HUMID DAY THROUGHOUT THE MIDSOUTH. HEAT
ADVISORY CRITERIA HAS BEEN MET AT ALL 4 CLIMATE SITES AS
TEMPERATURES CLIMB INTO THE MID TO UPPER 90S. MOISTURE CONTINUES
TO POOL INTO THE MIDSOUTH AHEAD OF A CLUSTER OF THUNDERSTORMS THAT
HAVE ENTERED THE NORTHWESTERN CORNER OF OUR CWA AND WILL CONTINUE
TO MOVE SOUTHEAST TOWARDS THE MISSISSIPPI RIVER. WE ARE ALSO
MONITORING THE NORTHEASTERN PORTIONS OF THE CWA FOR CONVECTION
THAT IS THE RESULT OF WAA ALONG AN OUTFLOW BOUNDARY PRODUCED BY A
DECAYING MCS FURTHER EAST. THE HRRR FORMS A LINE OF THESE TWO
DISTURBANCES AND CARRIES THEM SOUTHWARD INTO NORTH MISSISSIPPI
BEFORE THEY BEGIN TO DIE AS WE LOSE DAYTIME HEATING. AN EXTREMELY
UNSTABLE PRE STORM AIRMASS AIR MASS EXISTS AHEAD OF THESE STORMS
THROUGHOUT THE MIDSOUTH WITH SBCAPE VALUES RANGING FROM 4500-6500
J/KG. SEVERE WIND GUSTS WILL BE THE MAIN THREAT WITH ANY STORMS
TODAY. THE WALNUT RIDGE AWOS STATION HAS ALREADY REPORTED A WIND
GUST OF 66 MPH AT 1935Z. SEVERE HAIL WILL BE A SECONDARY THREAT.
TEMPERATURES TOMORROW WILL BE 1-2 DEGREES COOLER THAN TODAY AS
CLOUD COVER ASSOCIATED WITH A WEAK COLD FRONT PROHIBIT THE TYPE OF
TEMPS THAT WE SAW TODAY. THE HEAT ADVISORY WILL BE RE-EVALUATED
DURING THE MIDNIGHT SHIFT.
TEMPERATURES INCREASE TO THE 90S ON THURSDAY THROUGH THE WEEKEND
AS THE UPPER LEVEL RIDGE SHIFTS EAST AND BECOMES CENTERED OVER
THE LOWER MISSISSIPPI RIVER VALLEY. HEAT INDICES WILL ONCE AGAIN
BECOME OPPRESSIVE FROM THURSDAY THROUGH EARLY NEXT WEEK. TEMPS AT
THE 850 MB LEVEL WILL REMAIN 22-23C. THAT CORRELATES TO
TEMPERATURES IN THE UPPER 90S AT THE SURFACE. DEWPOINTS WILL BE IN
THE LOWER TO MID 70S EACH DAY. CONFIDENT IN THE NEED FOR HEAT
ADVISORIES FOR AT LEAST A FEW IF NOT EVERY DAY THROUGHOUT THE
PERIOD.
LONG TERM MODELS AGREE ON THE UPPER RIDGE BREAKING DOWN AND
RETROGRADING WEST BY NEXT WEDNESDAY. THIS SHOULD RESULT IN COOLER
TEMPS BY MID WEEK.
JPM3
&&
.AVIATION...
CONVECTION WRAPPING UP ACROSS THE TAF SITES...WITH T-STORMS
INITIALLY NEAR TUP. LATER TONIGHT ISOLATED T-STORMS COULD
REFORM...BUT COVERAGE APPEARS TOO MINIMAL TO PLACE IN TAF BODY.
OTHERWISE...CIGS WILL BE VFR THROUGH THE NIGHT WITH THE
POSSIBILITY OF FOG/MVFR VSBY AT ALL SITES EXCEPT MEM. WINDS
OUTSIDE OF CONVECTION WILL BECOME LIGHT FROM THE SOUTHWEST OR WEST
SHIFTING NORTH AND NORTHEAST WEDNESDAY MORNING AS A WEAK FRONT
PUSHES IN. VC T-STORMS LATE IN THE PERIOD AT MEM...JBR AND TUP.
JAB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...HEAT ADVISORY UNTIL 7 PM CDT WEDNESDAY FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI-
PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...HEAT ADVISORY UNTIL 7 PM CDT WEDNESDAY FOR DUNKLIN-PEMISCOT.
MS...HEAT ADVISORY UNTIL 7 PM CDT WEDNESDAY FOR ALCORN-BENTON MS-
CALHOUN-CHICKASAW-COAHOMA-DESOTO-ITAWAMBA-LAFAYETTE-LEE MS-
MARSHALL-MONROE-PANOLA-PONTOTOC-PRENTISS-QUITMAN-
TALLAHATCHIE-TATE-TIPPAH-TISHOMINGO-TUNICA-UNION-YALOBUSHA.
TN...HEAT ADVISORY UNTIL 7 PM CDT WEDNESDAY FOR BENTON TN-CARROLL-
CHESTER-CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-
HARDIN-HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-
MCNAIRY-OBION-SHELBY-TIPTON-WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
622 PM CDT TUE JUL 14 2015
.DISCUSSION...
UPDATED FOR 00Z AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 459 PM CDT TUE JUL 14 2015/
.UPDATE...
UPDATE TO INCREASE POPS ACROSS MUCH OF THE REGION AND CLEAN UP
SEVERE THUNDERSTORM WATCH PRODUCTS.
DISCUSSION...
A FORWARD PROPAGATING MESOSCALE CONVECTIVE SYSTEM (MCS) IS
ADVANCING THROUGH SOUTHERN WEST TENNESSEE AND PORTIONS OF NORTH
MISSISSIPPI. THIS SYSTEM HAS HAD A HISTORY OF WIDESPREAD AND
SOMETIMES SIGNIFICANT WIND DAMAGE WITH WIND GUSTS IN EXCESS OF 70
MPH AT TIMES. THERE HAS ALSO BEEN TRAINING THUNDERSTORMS ACROSS
WEST TENNESSEE NEAR THE I-40 CORRIDOR WHERE LOW LEVEL CONVERGENCE
IS BECOMING MAXIMIZED. THIS REGION WILL BE AN AREA WHERE HEAVY
RAINFALL AND FLASH FLOODING WILL BECOME MORE OF AN ISSUE WITH TIME
THROUGH THIS EVENING.
CONVECTION SHOULD CONTINUE TO ADVANCE THROUGH EAST ARKANSAS AND
NORTH MISSISSIPPI THROUGH THE REMAINDER OF THIS EVENING AS THE
CONVECTIVE LINE MOVES INTO A STRONGLY UNSTABLE ENVIRONMENT
CHARACTERIZED BY MLCAPE VALUES IN EXCESS OF 3500 J/KG. ALSO...A
WELL ESTABLISHED COLD POOL WILL SUSTAIN STORM STRUCTURE AND
CONTINUED WIND DAMAGE POTENTIAL IS EXPECTED. STORM COVERAGE AND
INTENSITY SHOULD DIMINISH AREAWIDE AFTER MIDNIGHT.
UPDATED PRODUCTS HAVE BEEN SENT AND WILL BE UPDATED AS NEEDED
THROUGH THE EVENING.
JLH
&&
.PREV DISCUSSION... /ISSUED 344 PM CDT TUE JUL 14 2015/
DISCUSSION...
CURRENTLY... ANOTHER WARM HUMID DAY THROUGHOUT THE MIDSOUTH. HEAT
ADVISORY CRITERIA HAS BEEN MET AT ALL 4 CLIMATE SITES AS
TEMPERATURES CLIMB INTO THE MID TO UPPER 90S. MOISTURE CONTINUES
TO POOL INTO THE MIDSOUTH AHEAD OF A CLUSTER OF THUNDERSTORMS THAT
HAVE ENTERED THE NORTHWESTERN CORNER OF OUR CWA AND WILL CONTINUE
TO MOVE SOUTHEAST TOWARDS THE MISSISSIPPI RIVER. WE ARE ALSO
MONITORING THE NORTHEASTERN PORTIONS OF THE CWA FOR CONVECTION
THAT IS THE RESULT OF WAA ALONG AN OUTFLOW BOUNDARY PRODUCED BY A
DECAYING MCS FURTHER EAST. THE HRRR FORMS A LINE OF THESE TWO
DISTURBANCES AND CARRIES THEM SOUTHWARD INTO NORTH MISSISSIPPI
BEFORE THEY BEGIN TO DIE AS WE LOSE DAYTIME HEATING. AN EXTREMELY
UNSTABLE PRE STORM AIRMASS AIR MASS EXISTS AHEAD OF THESE STORMS
THROUGHOUT THE MIDSOUTH WITH SBCAPE VALUES RANGING FROM 4500-6500
J/KG. SEVERE WIND GUSTS WILL BE THE MAIN THREAT WITH ANY STORMS
TODAY. THE WALNUT RIDGE AWOS STATION HAS ALREADY REPORTED A WIND
GUST OF 66 MPH AT 1935Z. SEVERE HAIL WILL BE A SECONDARY THREAT.
TEMPERATURES TOMORROW WILL BE 1-2 DEGREES COOLER THAN TODAY AS
CLOUD COVER ASSOCIATED WITH A WEAK COLD FRONT PROHIBIT THE TYPE OF
TEMPS THAT WE SAW TODAY. THE HEAT ADVISORY WILL BE RE-EVALUATED
DURING THE MIDNIGHT SHIFT.
TEMPERATURES INCREASE TO THE 90S ON THURSDAY THROUGH THE WEEKEND
AS THE UPPER LEVEL RIDGE SHIFTS EAST AND BECOMES CENTERED OVER
THE LOWER MISSISSIPPI RIVER VALLEY. HEAT INDICES WILL ONCE AGAIN
BECOME OPPRESSIVE FROM THURSDAY THROUGH EARLY NEXT WEEK. TEMPS AT
THE 850 MB LEVEL WILL REMAIN 22-23C. THAT CORRELATES TO
TEMPERATURES IN THE UPPER 90S AT THE SURFACE. DEWPOINTS WILL BE IN
THE LOWER TO MID 70S EACH DAY. CONFIDENT IN THE NEED FOR HEAT
ADVISORIES FOR AT LEAST A FEW IF NOT EVERY DAY THROUGHOUT THE
PERIOD.
LONG TERM MODELS AGREE ON THE UPPER RIDGE BREAKING DOWN AND
RETROGRADING WEST BY NEXT WEDNESDAY. THIS SHOULD RESULT IN COOLER
TEMPS BY MID WEEK.
JPM3
&&
.AVIATION...
CONVECTION WRAPPING UP ACROSS THE TAF SITES...WITH T-STORMS
INITIALLY NEAR TUP. LATER TONIGHT ISOLATED T-STORMS COULD
REFORM...BUT COVERAGE APPEARS TOO MINIMAL TO PLACE IN TAF BODY.
OTHERWISE...CIGS WILL BE VFR THROUGH THE NIGHT WITH THE
POSSIBILITY OF FOG/MVFR VSBY AT ALL SITES EXCEPT MEM. WINDS
OUTSIDE OF CONVECTION WILL BECOME LIGHT FROM THE SOUTHWEST OR WEST
SHIFTING NORTH AND NORTHEAST WEDNESDAY MORNING AS A WEAK FRONT
PUSHES IN. VC T-STORMS LATE IN THE PERIOD AT MEM...JBR AND TUP.
JAB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...HEAT ADVISORY UNTIL 7 PM CDT WEDNESDAY FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI-
PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...HEAT ADVISORY UNTIL 7 PM CDT WEDNESDAY FOR DUNKLIN-PEMISCOT.
MS...HEAT ADVISORY UNTIL 7 PM CDT WEDNESDAY FOR ALCORN-BENTON MS-
CALHOUN-CHICKASAW-COAHOMA-DESOTO-ITAWAMBA-LAFAYETTE-LEE MS-
MARSHALL-MONROE-PANOLA-PONTOTOC-PRENTISS-QUITMAN-
TALLAHATCHIE-TATE-TIPPAH-TISHOMINGO-TUNICA-UNION-YALOBUSHA.
FLASH FLOOD WATCH UNTIL 1 AM CDT WEDNESDAY FOR ALCORN-PRENTISS-
TIPPAH-TISHOMINGO.
TN...HEAT ADVISORY UNTIL 7 PM CDT WEDNESDAY FOR BENTON TN-CARROLL-
CHESTER-CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-
HARDIN-HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-
MCNAIRY-OBION-SHELBY-TIPTON-WEAKLEY.
FLASH FLOOD WATCH UNTIL 1 AM CDT WEDNESDAY FOR CHESTER-DECATUR-
HARDEMAN-HARDIN-HENDERSON-MADISON-MCNAIRY.
&&
$$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
737 PM EDT TUE JUL 14 2015
.SYNOPSIS...
LOW PRESSURE WAS OVER LAKE ERIE WITH A COLD FRONT TRAILING FROM
THE LOW INTO NORTHERN MISSOURI. THIS LOW AND COLD FRONT WILL MOVE
SOUTHEAST TONIGHT AND WEDNESDAY AND WILL BE OFF THE MID ATLANTIC
COAST BY WEDNESDAY NIGHT. HIGH PRESSURE...AND LESS HUMID
AIR...WILL BUILD IN BEHIND THE FRONT AND WILL COVER THE REGION
THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS 730 PM EDT TUESDAY...
SVR THUNDERSTORM WATCH 426 IN EFFECT FOR MOST OF OUR FORECAST AREA
UNTIL 1 AM. MAIN LINE OF STRONG TO SEVERE TSRA LIES FROM
GREENBRIER TO THE KY/VA BORDER MOVING SE AT 40-50 MPH. ISOLATED
STORMS ARE FIRING IN THE PIEDMONT IN BETTER MOISTURE POOLING AND
SBCAPES OF 1500 J/KG. BEST EFFECTIVE SHEAR EXISTS OVER KY INTO WV
WITH BETTER CAPES IN THE PIEDMONT HENCE THE AREAL COVERAGE OF THE
WATCH. NO OTHER MAJOR CHANGES TO THE FORECAST THIS UPDATE.
PREVIOUS DISCUSSION AT 4 PM...
FLASH FLOOD GUIDANCE WAS LOW IN THE MOUNTAINS...AND FLASH FLOOD
THREAT WAS HIGHEST IN GREENBRIER COUNTY DOWN TO TAZEWELL COUNTY. NO
FLASH FLOOD WATCH AT THIS TIME SINCE STORMS MOTION WILL LIMIT
HEAVY RAIN...EVEN THOUGH RATES MAY BE HIGH.
UPPER TROF AXIS FORECAST TO BE EXITING THE EASTERN COUNTY WARNING
AREA WEDNESDAY MORNING. SURFACE COLD FRONT ALSO CROSSES THROUGH THE
FORECAST AREA IN THE MORNING.
HAVE HIGH PROBABILITY OF PRECIPITATION THROUGH MIDNIGHT USING THE
TIMING OF THE HRRR AND SPC HRRR. PROBABILITY OF PRECIPITATION WILL
DROP OFF SHARPLY AFTER THE FRONT GOES BY IN THE MORNING...WITH THE
UPSLOPE AREAS HAVE THE BEST CHANCE OF GETTING SHOWERS.
TEMPERATURES OVERNIGHT WILL REMAIN MILD WITH SURFACE DEW POINTS FROM
THE LOWER 60S TO LOWER 70S. STAYED CLOSED TO COOLED GUIDANCE BEHIND
THE FRONT FOR MAXIMUM TEMPERATURES ON WEDNESDAY. AS USUAL...AMOUNT
OF CLOUD COVER IN THE MORNING WILL HAVE A LARGE INFLUENCE ON THE
DAYTIME HIGHS.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
AS OF 100 PM EDT TUESDAY...
WEDNESDAY NIGHT THROUGH FRIDAY NIGHT NIGHT MAY BE ONE OF THE DRIEST
TIME PERIODS WE HAVE HAD FOR A WHILE. THIS PATTERN IS BEING ATTRIBUTED
TO BOTH SURFACE HIGH PRESSURE...AND AN UPPER RIDGE OF HIGH PRESSURE
BUILDING OVER THE REGION. THIS WILL HAVE THE IMPACT OF SQUELCHING
ANY CONVECTION AND TRENDING TEMPERATURES COOLER...AS COMPARED TO
READINGS DURING THE EARLY PART OF THE WEEK. OUR SMALL CHANCES OF
PRECIPITATION WILL COME IN TWO FORMS ON DIFFERENT DAYS.
ON WEDNESDAY EVENING...CONVECTION FROM WEDNESDAY AFTERNOON OVER
SOUTHEAST WEST VIRGINIA WILL LINGER INTO THE EVENING HOURS...BUT
DISSIPATE QUICKLY..AND LIKELY BE ONLY SHOWERS.
ON FRIDAY...THE CENTER OF THE SURFACE HIGH SHIFTS A BIT EAST...AND A
WEAK SOUTHEAST UPSLOPE FLOW DEVELOPS. THIS MAY ALLOW FOR ENOUGH
CONVERGENCE TO HELP INCREASE THE MAGNITUDE OF THE LIFT THAT PURE
DIURNAL HEATING WILL GENERATE. THIS EXTRA LIFT MAY ALLOW FOR
ISOLATED STORMS TO DEVELOP.
WHILE THE FORECAST WILL REFLECT A DRY FRIDAY NIGHT...SOME MODEL
GUIDANCE IS HINTING THAT SOME CONVECTION MAY REACH THE WESTERN PARTS
OF THE REGION BY LATE IN THE NIGHT IN ADVANCE OF OUR NEXT
APPROACHING GREAT LAKES SYSTEM. FOR NOW...THE FORECAST WILL FAVOR
THE SLOWER SOLUTIONS...AND THUS KEEP THE FORECAST PRECIPITATION FREE.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 130 PM EDT TUESDAY...
DURING THIS PORTION OF THE FORECAST WE WILL RETURN TO A WETTER
PATTERN...ONE NOT TOO UNLIKE WHAT HAS BEEN THE NORM FOR THE FIRST
HALF OF JULY. THE NORTHERN JET WILL PLAY A GREATER ROLE IN OUR
WEATHER PATTERN...BRINGING SHORTWAVE AFTER SHORTWAVE ACROSS THE TOP
OF THE UPPER RIDGE AXIS. THIS WILL HAVE THE AFFECT OF RETROGRADING
THE CENTER OF THE RIDGE BACK TO THE MIDDLE MISSISSIPPI VALLEY WITH
NORTHWEST FLOW AGAIN THE DOMINANT STEERING FLOW ACROSS OUR REGION.
LOOK FOR A RETURN OF DAILY SHOWERS AND THUNDERSTORMS. SOME TIME
PERIODS WILL HAVE A GREATER COVERAGE WITH THE POTENTIAL FOR
THUNDERSTORM COMPLEXES TO AGAIN HEAD INTO OR THROUGH THE REGION.
WHILE TIMING WILL LIKELY CHANGE...THE LATEST GUIDANCE OFFERS A
SOLUTION OF SATURDAY NIGHT...AND THEN AGAIN TUESDAY OR TUESDAY NIGHT
AS THE MOST LIKELY TIME FRAME FOR THESE. TEMPERATURES WILL TREND
WARMER BY THE END OF THE WEEKEND...AND THEN WARM A LITTLE BIT MORE
BY TUESDAY.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
AS OF 730 PM EDT TUESDAY...
TRYING TO TIME LINE OF CONVECTION AND INCLUDED IN ALL TAFS AS
THINK LINE WILL HOLD TOGETHER ENOUGH GIVEN STRONG INSTABILITY TO
THE EAST AND DYNAMICS ACROSS THE AREA FROM UPPER JET.
BASICALLY LOOKING AT NOW UNTIL 02Z FOR THE MTNS...TO 01-3Z EAST
WITH LINGER SHOWERS AT LEAST UNTIL 06Z. COULD BE SOME FOG
OVERNIGHT IF THE MIXING OF THE AIRMASS DOES NOT ARRIVE BEHIND THIS
SYSTEM...GIVEN EXTENT OF RAIN/GROUND MOISTURE.
CIGS/VSBYS WILL IMPROVE TO VFR AFTER THE STORMS MOVE ACROSS...WITH
WINDS STAYING MORE OUT OF THE WEST.
AFTER FRONTAL PASSAGE AND SHORTWAVE WEDNESDAY EXPECT HIGH PRESSURE
TO BUILD ACROSS THE NORTHEAST AND KEEP US VFR.
EXTENDED AVIATION DISCUSSION...
VFR FOR WEDNESDAY NIGHT INTO FRIDAY. CANNOT RULE OUT SOME WIDELY
SCATTERED AFTERNOON AND EVENING SHOWERS...BUT NOT EXPECTING
ANYTHING ORGANIZED FOR THE LATER HALF OF THE WEEK.
WITH OPPORTUNITY FOR CLEARING TO TAKE PLACE AT NIGHT...WILL HAVE
SOME MORNING FOG/LOW CLOUDS ISSUES IN THE MOUNTAIN VALLEYS...AND
GROUND FOG FOR THE LOW LYING AREAS OF THE FOOTHILLS AND PIEDMONT.
OVERALL CONDITIONS HOWEVER SHOULD BE MAINLY VFR.
THE CHANCE OF SHOWERS AND THUNDERSTORMS RETURNS TO THE REGION ON
SATURDAY AND SUNDAY. MVFR CONDITIONS ARE POSSIBLE WITH ANY OF THE
STORMS. OTHERWISE VFR CEILINGS AND VISIBILITIES ARE EXPECTED.
&&
.EQUIPMENT...
AS OF 1000 AM EDT TUESDAY...
NOAA WEATHER RADIO STATION WXM72 IN HINTON WEST VIRGINIA...
OPERATING ON A FREQUENCY OF 162.425 MEGAHERTZ...IS EXPERIENCING
INTERMITTENT OUTAGES. TECHNICIANS ARE ADDRESSING THE PROBLEM.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/WP
SHORT TERM...DS
LONG TERM...DS
AVIATION...AMS/PM/WP
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
221 AM EDT MON JUL 13 2015
.SYNOPSIS...
A WEAK WARM FRONT WILL LIFT SLOWLY NORTHEAST TOWARD THE REGION
TONIGHT BEFORE PASSING TO THE NORTH LATER MONDAY INTO MONDAY NIGHT.
NORTHWEST FLOW ALOFT WILL ALLOW UPPER LEVEL DISTURBANCES TO SPILL
SOUTHEAST INTO THE AREA ALONG THE BOUNDARY THROUGH TUESDAY
RESULTING IN PERIODIC ROUND OF SHOWERS AND THUNDERSTORMS. A WEAK
COOL FRONT SHOULD DROP THROUGH THE REGION FROM THE NORTH BY MID
WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 730 PM EDT SUNDAY...
STILL NO CLEAR MODEL CONSENSUS ON TIMING OR INTENSITY OF
PRECIPITATION...BUT SO FAR TODAY...ONLY RAIN SHOWERS HAVE IMPACTED
THE CWA. A CELL WEST OF TAZEWELL ONGOING CURRENTLY...IS THE FIRST
CELL I HAVE SEEN EVEN NEAR OUR CWA YET TO EXHIBIT ANY LIGHTNING.
MESO-SCALE MODELS HAVE VARYING DEGREES OF CONVECTION IMPACTING THE
AREA OVERNIGHT. THE HRRR BRINGS THE ACTIVITY CURRENTLY IN KENTUCKY
INTO OUR REGION IN A DIMINISHED STATE TOWARD MIDNIGHT. THE LOCAL
WRF KEEPS ALL SIGNIFICANT ACTIVITY WEST OF I-77...DROPPING THE
MOST INTENSE CONVECTION SOUTHWARD THROUGH EASTERN KY/EASTERN TN.
NCEP WRF MODELS IN BETWEEN...BUT AGAIN SHOW NOTHING SIGNIFICANT IN
OUR CWA TODAY OR TOMORROW. HAVE ADJUSTED POPS SOMEWHAT OVERNIGHT
INTO THE EARLY MORNING HOURS TO ACCOUNT FOR BETTER THREAT FOR
CONVECTION WEST OF I-77...LESS LEAST OF THE BLUE RIDGE. ONLY MINOR
ADJUSTMENTS TO T/TD NEEDED AT THIS TIME.
AS OF 355 PM EDT SUNDAY...
MODELS OFFERING SEVERAL DIFFERENT SOLUTIONS FOR TONIGHT AND
MONDAY...ESPECIALLY LOOKING AT WINDS...LOCATION OF PRECIPITATION
AND MAXIMUM TEMPERATURES ON MONDAY.
SATELLITE TOTAL PRECIPITABLE WATER PRODUCT AND VERTICAL PROFILERS
INDICATED PRECIPITABLE WATER VALUES HAVE RISEN TO AROUND 1.5
INCHES. WIDELY SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS HAVE
DEVELOPED ON THE EASTERN EDGE OF A OLD MESOSCALE COMPLEX. SOME
GUIDANCE SUGGESTS THE CHANCE OF PRECIPITATION WILL EXTEND WELL
INTO THE EASTERN COUNTY WARNING AREA TONIGHT.
ANOTHER CLUSTER OF SHOWERS AND THUNDERSTORMS WILL DEVELOP UPSTREAM
TONIGHT WITH MORE PRECIPITATION IN THE FORECAST AREA MONDAY
AFTERNOON. BUT OVERALL INSTABILITY AND SHEAR IS MARGINAL. BELIEVE
BEST PROBABILITY FOR PRECIPITATION AND HIGHEST RAINFALL AMOUNTS
WILL BE ALONG AND WEST OF I-77 THROUGH MONDAY AFTERNOON.
WITH HIGHER SURFACE DEW POINTS BACK IN THE AREA...MINIMUM TEMPERATURES
WILL BE MILDER TONIGHT THAN ON SUNDAY MORNING. THE AMOUNT OF CLOUD
COVER IN THE MORNING AND PRECIPITATION IN THE AFTERNOON WILL
IMPACT THE TEMPERATURES ON MONDAY. STAYED CLOSER TO BIAS CORRECTED
MAV GUIDANCE FOR TONIGHT AND ON MONDAY.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 230 PM EDT SUNDAY...
WEATHER SCENARIO REMAINS QUITE COMPLICATED WITH TIMING OF FEATURES
ACROSS THE AREA WITHIN A VERY MOIST/UNSTABLE ENVIRONMENT WHILE LIMITED
VIA WESTERLY WINDS ALOFT AND ONLY WEAK SURFACE FEATURES UNTIL LATE
TUESDAY. LATEST SUITE OF SOLUTIONS SUGGEST THAT MAY INIT BETWEEN UPPER
WAVES MONDAY EVENING AS A LEAD SHORTWAVE EXITS THE PIEDMONT AHEAD OF
PERHAPS ANOTHER UPSTREAM VORT/MCS THAT LOOKS TO DIVE SE TOWARD THE
SOUTHERN APPALACHIANS BY EARLY TUESDAY. APPEARS THIS IMPULSE MAY ACT TO
ENHANCE CONVERGENCE ALONG THE WESTERN SLOPES MONDAY EVENING WITH SOME
OF THIS POSSIBLY JETTING ACROSS THE SW OVERNIGHT ALONG THE RETREATING
WARM FRONT. THIS COULD PROVIDE A TIGHT GRADIENT TO POPS WITH LITTLE OUT
EAST AFTER ANY EVENING COVERAGE FADES WITH A COUPLE ROUNDS POSSIBLE OUT
WEST WHERE FOR NOW WILL KEEP OVERALL LIKELY POPS IN PLACE.
STRONG UPPER TROUGH FOR JULY WILL DIG SE OUT OF THE GREAT LAKES TUESDAY
BEFORE SLIDING TO NEAR THE DELMARVA ON WEDNESDAY. THIS WILL PUSH THE
TRAILING SHORTWAVE TROUGH AXIS SE TOWARD THE REGION LATE IN THE DAY
TUESDAY...AIDED BY INCREASING WINDS ALOFT AND HIGH INSTABILITY...
PROVIDED CAN GET ENOUGH HEATING THROUGH RESIDUAL DEBRIS CLOUDS...AND
ISOLATED SHOWERS ESPCLY WEST. HOWEVER GUIDANCE SHOWS A VERY PRONOUNCED
WEST/NW TRAJECTORY JUST ABOVE THE BOUNDARY LAYER WHICH WOULD TEND TO
FOCUS MOST BANDED CONVECTION OVER THE WEST AS THE NW FLOW CONVEYOR BELT
SHOULD BE ABOUT OVERHEAD BY THEN. LEE TROUGH ALSO QUITE STRONG BY LATER
TUESDAY WHICH IN CONJUNCTION WITH A SURFACE LOW FORMING IN RESPONSE TO
THE 5H SYSTEM MAY CAUSE A QUICK JUMP TO THE EAST OF THE AREA LATE IN
THE DAY. SINCE THIS LOOKS QUITE REALISTIC PENDING TIMING...WILL ADJUST
POPS TO HIGHER LIKELYS FAR WEST TUESDAY PER HIGH FORECAST THETA-
E/DIVERGENCE ALOFT...AND GO HIGHER CHANCE EAST WITH LEAST COVERAGE BLUE
RIDGE GIVEN DOWNSLOPE INTO TUESDAY NIGHT. THIS APPEARS TO BE THE PERIOD
FOR MORE WIDESPREAD SEVERE SO KEEPING IN THE HWO PER GOING SPC
OUTLOOKS.
AREA WILL SPILL UNDER THE COLD POOL ALOFT WITH THE 5H LOW TO THE NE ON
WEDNESDAY WITH QUITE A BIT OF SUPPORT ROTATING AROUND THIS FEATURE TO
KEEP DECENT LIFT GOING THROUGH LATE WEDNESDAY. THINK MORE OF A
NORTHERLY TRAJECTORY SHOULD TEND TO LIMIT SHRA ACROSS THE FAR SOUTH BUT
APPEARS COULD SEE MORE WIDESPREAD WEAKER SHRA/ISOLATED TSRA WEDNESDAY
BEFORE DRIER AIR ALOFT ADVECTS IN AND ENDS THE SHOWER THREAT DURING THE
EVENING. OVERALL PLAN TO KEEP POPS ON THE CHANCE SIDE PENDING LATER
RUNS SINCE THE DEGREE OF RESIDUAL MOISTURE RATHER UNCERTAIN FOR NOW.
KEPT TEMPS ON THE WARM SIDE OF MOS INTO TUESDAY NIGHT WITH LOW AND EVEN
MID 90S POSSIBLE EAST TUESDAY IF CLOUDS/SHRA ARE LESS. SHOULD BE A BIT
COOLER UNDER MORE CLOUDS...SHOWERS AND NORTHERLY FLOW WEDNESDAY WITH
MOSTLY 80S EXCEPT PERHAPS ONLY SOME 70S FOR HIGHS WEST.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 100 PM EDT SUNDAY...
5H HEIGHTS WILL BUILD EAST ACROSS THE REGION THROUGH MUCH OF THE PERIOD
AS THE LARGE UPPER HIGH OVER THE SOUTHERN PLAINS NUDGES EASTWARD INTO
NEXT WEEKEND. THIS SHOULD MEAN A MORE DIURNALLY DRIVEN LESS ORGANIZED
PATTERN TO CONVECTION AS FOCUS SHIFTS TO MORE OUTFLOW DRIVEN SHRA/TSRA
PERHAPS AIDED BY FAINT SHORTWAVE ENERGY PASSING AROUND THE RIDGE IN THE
WEST/NW FLOW ALOFT. INITIALLY SHOULD BE IN THE WAKE OF THE FRONT TO THE
SOUTH AND THE UPPER SYSTEM TO THE EAST THURSDAY...WITH WEAK HIGH
PRESSURE TO THE NORTH BRINGING A PERIOD OF WEAK SUBSIDENCE THURSDAY
INTO THURSDAY NIGHT INCLUDING ONLY ISOLATED CONVECTION AT BEST.
MOISTURE SHOULD START TO MAKE A SLOW RETURN FRIDAY AND ESPCLY SATURDAY
AS THE WEAK FRONT SHIFTS BACK NORTH AND WEAK RETURN FLOW DEVELOPS. THIS
LOOKS TO BRING SCATTERED NATURE POPS BACK BY FRIDAY AFTERNOON WITH
HIGHER CHANCES SATURDAY UNDER BETTER PWATS. NEXT WEAK UPPER TROUGH AND
ITS ASSOCIATED COOL FRONT APPROACHES ON SUNDAY WHILE PRECEDED BY MORE
WESTERLY FLOW. THIS SUGGESTS BEST CHANCE POPS WEST/NORTH AND LESS OUT
EAST DESPITE DEEP MOISTURE AND GOOD HEATING.
A SLIGHTLY COOLER/DRIER PERIOD THURSDAY/THURSDAY NIGHT LOOKS TO REBOUND
BACK TO HIGHS OF 85-90 WEST AND LOW/MID 90S EAST BY NEXT WEEKEND UNDER
WESTERLY FLOW AND PROGGED 85H TEMPS OF +22-23C.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 200 AM EDT MONDAY...
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP OVER THE AREA
THROUGH DAYBREAK AS W-E NOCTURNAL 85H JET FEEDS UNSTABLE AIR INTO
THE REGION FROM THE OHIO VALLEY. THERE HAS BEEN A CONSIDERABLE
AMOUNT OF LIGHTNING WITH THESE STORMS IN ADDITIONS TO TORRENTIAL
DOWNPOURS WITH IFR VSBYS.
THE 85H JET IS EXPECTED TO WEAKEN AFTER DAYBREAK YIELDING A DEMISE
IN THE SHOWER ACTIVITY BETWEEN 12Z/8AM AND 15Z/11AM. VFR
CONDITIONS ARE EXPECTED TO RETURN AFTER 15Z AND PERSIST THROUGH
THE AFTERNOON.
NEXT OPPORTUNITY FOR SHOWERS/STORMS WITH POTENTIAL TO DISRUPT
AVIATION WILL COME FROM AN ORGANIZED MESOSCALE CONVECTIVE SYSTEM
WHICH IS EXPECTED TO DROP SOUTHEAST FROM THE UPPER MIDWEST
TODAY...CROSSING THE OHIO VALLEY LATE THIS AFTERNOON. THIS FEATURE
WILL LIKELY BE ACCOMPANIED BY SEVERE WEATHER...WITH THE POTENTIAL
TO IMPACT THE CENTRAL APPALACHIANS TOWARD SUNSET. FOR NOW WILL
PLACE VCTS IN THE TAFS BEGINNING 00Z/8PM AND WILL REFINE THE
FORECAST AS RADAR TRENDS DICTATE.
WINDS TODAY ARE EXPECTED TO BE LIGHT AND VARIABLE. THE ONLY
EXCEPTION WILL BE POTENTIAL FOR WIND GUSTS OF 20 KTS VCNTY OF
SHOWERS/STORMS THIS MORNING. THE STORM COMPLEX WHICH IS FORECAST
TO DROP SOUTHEAST THROUGH THE OHIO VALLEY IS EXPECTED TO CONTAIN
SEVERE GUSTS...50 KTS OR MORE. THE STORM PREDICTION CENTER HAS
POSTED A MODERATE RISK FOR SEVERE WEATHER FROM ILLINOIS TO
KENTUCKY.
EXTENDED AVIATION DISCUSSION...
POTENTIAL FOR NUMEROUS SHOWERS/STORMS WILL CONTINUE THROUGH
TUESDAY. AN ACTIVE NORTHWEST/BAROCLINIC FLOW WILL REMAIN IN PLACE
ALONG THE NORTHEAST SIDE OF A STRONG SUBTROPICAL RIDGE OF HIGH
PRESSURE ANCHORED IN THE SOUTHERN PLAINS. ONE OR MORE CONVECTIVE
COMPLEXES APPEAR LIKELY WITHIN THIS TIME FRAME...BUT LOW
CONFIDENCE ON EXACT TIMING ATTM. PLACEMENT FAVORS A TRACK FROM THE
UPPER MIDWEST THROUGH THE LOWER OHIO VALLEY AND INTO THE SOUTHERN
APPALACHIANS.
MORE TYPICAL SUMMERTIME CONDITIONS RETURN FOR THE LATER
HALF OF THE WEEK WITH EARLY MORNING FOG/LOW CLOUDS IN THE USUAL
SPOTS...KLWB/KBCB/KLYH...AND ISOLATED TO SCATTERED AFTERNOON/EVENING
SHOWERS AND THUNDERSTORMS. OVERALL...CIGS AND VSBYS SHOULD BE VFR
MUCH OF THE TIME PERIOD.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/PM
NEAR TERM...AMS/RAB
SHORT TERM...JH
LONG TERM...JH
AVIATION...PM
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
329 PM CDT MON JUL 13 2015
.SHORT TERM...
.TONIGHT... FORECAST CONFIDENCE MEDIUM.
INSTABILITY IS ON THE RISE IN SOUTH CENTRAL WI WITH MIXED LAYER CAPE
OVER 2500 J/KG AND NO CIN PER LATEST SPC MESOANALYSIS PAGE. THIS
AXIS OF INSTABILITY EXTENDS NORTHWESTWARD THROUGH EAST CENTRAL MN.
THUNDERSTORMS ARE POPPING UP IN THAT AREA AS OF 20Z AS A SHORTWAVE
WORKS INTO THE AREA. THE HRRR MODEL AND OTHER MESO MODELS HAVE BEEN
CONSISTENT IN DEVELOPING THUNDERSTORMS EAST CENTRAL/SOUTHEAST MN AND
THEY HAVE THE THUNDERSTORMS CONTINUING TO DEVELOP DOWNSTREAM WITH
THE SHORTWAVE. ALL OF SOUTHERN WI IS UNDER A SEVERE THUNDERSTORM
WATCH THROUGH 02Z OR 9 PM.
THE HIGH CAPE FORECAST OF 3500-4500 J/KG /DEPENDING ON MODEL/ AND
HIGH UNIDIRECTIONAL SHEAR AROUND 40 KNOTS SUPPORTS RAPID SUPERCELL
DEVELOPMENT. LARGE HAIL AND DAMAGING WINDS ARE LIKELY WITH THESE
STORMS. A TORNADO IS POSSIBLE.
STAY TUNED FOR UPDATES AND POTENTIAL SEVERE THUNDERSTORM WARNINGS.
AFTER THESE STORMS ROLL THROUGH... THERE IS A SMALL CHANCE FOR
ANOTHER ROUND OF WEAKER SHOWERS AND THUNDERSTORMS WITH ANOTHER
SHORTWAVE TRACKING THROUGH SOUTHERN WI LATE TONIGHT.
TUESDAY... FORECAST CONFIDENCE MEDIUM.
A COLD FRONT WILL SLIDE SOUTHWEST DOWN LAKE MICHIGAN THROUGH SOUTH
CENTRAL WI TUESDAY AFTERNOON IN THE WAKE OF AN UPPER LEVEL
SHORTWAVE. LOOK FOR A WIND SHIFT TO THE NORTH-NORTHEAST AND FALLING
TEMPERATURES. THERE MAY BE A LOW CLOUD DECK ALONG THE LEADING EDGE
OF THE FRONT. MODELS ARE SHOWING LOW CAPE AND LIGHT QPF... SO SOME
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ALONG THE FRONT AS THEY
COLLIDE WITH THAT WARM AND MOIST AIR MASS IN PLACE.
.TUESDAY NIGHT AND WEDNESDAY...FORECAST CONFIDENCE MEDIUM
THE MID/UPPER LEVEL FLOW IS NORTHWEST AS A RIDGE EXITS THE DAKOTASAND
PUSHES INTO MINNESOTA. WEAK 700 MB DOWNWARD MOTION WITH MAINLY
WEAK UPPER CONVERGENCE UNTIL EVENING IN THE SOUTHWEST. 700 MB
DEWPOINTS ARE LOW...BUT BEGIN TO RISE WEDNESDAY AFTERNOON. 850 MB
TEMPERATURES COOL THROUGH THE PERIOD WITH THE 850 MB RIDGE OVER
WISCONSIN ON WEDNESDAY. 850 MB DEWPOINTS DROP THROUGH THE DAY
WEDNESDAY.
A BRISK NORTHEAST FLOW OFF LAKE MICHIGAN TUESDAY EVENING WITH
DIMINISH AS HIGH PRESSURE BUILDS INTO THE GREAT LAKES REGION.
DEWPOINTS ARE EXPECTED TO DROP INTO THE 40S AND LOWER 50S.
.WEDNESDAY NIGHT AND THURSDAY...FORECAST CONFIDENCE...MEDIUM.
THE UPPER RIDGE MOVES INTO WISCONSIN THURSDAY MORNING AS A
SHORTWAVE MOVES ACROSS THE NORTHERN/CENTRAL PLAINS. THE UPPER
DIVERGENCE INCREASES LATE WEDNESDAY NIGHT AND THURSDAY MORNING.
700 MB DEW POINTS CONTINUE TO INCREASE...ESPECIALLY OVER SOUTH
CENTRAL WISCONSIN. 700 MB UPWARD MOTION INCREASES...ESPECIALLY
THURSDAY.
AS THE SURFACE HIGH OVER THE GREAT LAKES RECEDES TO THE EAST...A
RETURN FLOW RESULTS IN A CHANCE OF THUNDERSTORMS
THURSDAY...ESPECIALLY OVER SOUTH CENTRAL WISCONSIN.
SURFACE DEWPOINTS ARE SLOW TO RISE INITIALLY BUT THEN INCREASES
INTO THE MID AND UPPER 60S OVER SOUTH CENTRAL WISCONSIN THURSDAY
AFTERNOON.
.LONG TERM...
.THURSDAY NIGHT AND FRIDAY...FORECAST CONFIDENCE MEDIUM
THE GFS AND 00Z ECMWF HAVE A FAIRLY ZONAL FLOW WITH ONE SHORTWAVE
EXITING WISCONSIN THURSDAY NIGHT AS A STRONG TROUGH DROPS INTO
THE NORTHWEST U.S.
A SURFACE TROUGH MOVES ACROSS WISCONSIN THURSDAY NIGHT AND OFF TO
LOWER MICHIGAN FRIDAY WITH AN AREA OF SHOWERS AND THUNDERSTORMS.
.SATURDAY...FORECAST CONFIDENCE MEDIUM
THE 00Z ECMWF PUSHES A MID LEVEL TROUGH INTO THE NORTHERN ROCKIES
AND NORTHERN PLAINS...WHILE THE GFS HAS A MORE CLOSED LOW OVER THE
PACIFIC NORTHWEST...WITH A SHORTWAVE MOVING TOWARD SOUTH CENTRAL
CANADA.
A SURFACE TROUGH DEVELOPS IN THE PLAINS WITH A WEAK SOUTH TO
SOUTHEAST FLOW OVER SOUTHERN WISCONSIN.
.SUNDAY AND MONDAY...FORECAST CONFIDENCE LOW
THE 00Z ECMWF MOVES A RATHER STRONG SHORTWAVE INTO
MINNESOTA SUNDAY AND INTO WISCONSIN MONDAY. HOWEVER THE 12Z GFS
STILL HAS A TROUGH OVER THE WESTERN U.S. SUNDAY THEN FINALLY
KICKING OUT A SHORTWAVE INTO THE NORTHERN PLAINS MONDAY
AFTERNOON.
BOTH MODELS SHOW SHOWER AND THUNDERSTORM CHANCES.
&&
.AVIATION/00Z TAFS/...
AREA OF DIURNAL CU WITH BASES AROUND 2000 FEET ARE SPREADING INTO
SOUTH CENTRAL WI THIS AFTERNOON WITH INCREASING DEWPOINT TEMPS AND
WSW WINDS. SCATTERED THUNDERSTORMS DEVELOPING IN SOUTHEAST MN NOW
WILL CONTINUE TO DEVELOP DOWNSTREAM IN WEST CENTRAL WI AND
EVENTUALLY SOUTH CENTRAL AND SOUTHEAST WI LATER THIS AFTERNOON AND
INTO THE EVENING. SOME STORMS COULD BE SEVERE. BRIEF MVFR CONDITIONS
AND GUSTY WINDS AND HAIL ARE POSSIBLE IN THESE THUNDERSTORMS.
THERE IS A CHANCE FOR WEAKER SHOWERS AND THUNDERSTORMS ACROSS
SOUTHERN WI LATER TONIGHT. A BRIEF PERIOD OF MVFR CIGS AND MAYBE
SOME SHOWERS/THUNDER WILL BE POSSIBLE WITH A COLD FRONT TRACKING
FROM NORTHERN LAKE MICHIGAN SOUTHWEST THROUGH SOUTHERN WI TUESDAY
AFTERNOON.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TONIGHT/TUESDAY AND AVIATION/MARINE...MRC
TUESDAY NIGHT THROUGH MONDAY...HENTZ
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1120 PM MDT SUN JUL 12 2015
.UPDATE...
ISSUED AT 921 PM MDT SUN JUL 12 2015
REGIONAL RADARS INDICATED THAT THE ISOLATED CONVECTION OVER THE
NORTHEAST CWA DISSIPATED SHORTLY AFTER SUNSET...WITH SKIES BECOMING
MOSTLY CLEAR. LIKEWISE...WIND SPEEDS DIMINISHED AND WILL REMAIN
BETWEEN 10 AND 15 MPH TONIGHT. UPDATED EVENING ZONES HAVE BEEN
DISSEMINATED.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH TUESDAY NIGHT)
ISSUED AT 258 PM MDT SUN JUL 12 2015
LOW-LEVEL CUMULUS CONTINUES TO EXPAND IN BOTH COVERAGE AND VERTICAL
EXTENT THIS AFTERNOON AS CONVECTIVE TEMPERATURES ARE REACHED. RECENT
TRENDS IN RADAR AND VISIBLE SATELLITE IMAGERY HAVE SHOWN DIFFICULTY
FOR CONVECTION TO INITIATE. THIS IS PARTIALLY DUE TO STRONG CAPPING
WITH H7 TEMPS AROUND +14 TO +16 DEG C AND LOW-LEVEL DRYING OWING TO
STRONG MIXING. THE MODELS DO NOT SHOW ANY QPF...AND THE HRRR OFFERS
LITTLE SUPPORT FOR THUNDERSTORMS TODAY. HOWEVER...OPTED TO MAINTAIN
SLIGHT CHANCE POPS THROUGH 00Z GIVEN THE RIGHT REAR QUADRANT OF A
110 KT H25 JET STREAK AND A MID-LEVEL VORT MAX OVERHEAD. SHORTWAVE
RIDGING AND RESULTANT SUBSIDENCE WILL KEEP THINGS DRY FROM TONIGHT
THROUGH MUCH OF THE DAY ON MON.
A WEAK FROPA IS STILL EXPECTED TO OCCUR ACROSS THE FAR NORTH EARLY
IN THE DAY ON MON...BUT THIS WILL HAVE LITTLE IMPACT ON OUR SENSIBLE
WEATHER AS WARM ADVECTION OCCURS BENEATH RIDGING ALOFT. THINK THIS
WILL KEEP CONVECTION SUPPRESSED OUTSIDE OF THE MOUNTAINS UNTIL AROUND
21-00Z. INCREASING MONSOONAL MOISTURE IN THE H7-H3 LAYER AND SEVERAL
DISTURBANCES EMBEDDED WITHIN SOUTHWEST FLOW ALOFT WILL ALLOW SHOWERS
AND THUNDERSTORMS TO DEVELOP EASTWARD ONTO THE PLAINS BY LATE AFTN
OR EARLY EVE. NAM/GFS BUFKIT SOUNDINGS SHOW BIG TIME DIFFERENCES IN
THE INSTABILITY PARAMETERS. THE NAM SHOWS 1500-2000 J/KG OF SBCAPE
OVER CYS ON MON AFTN...WHILE THE GFS SHOWS 200 J/KG AT MOST. 0 TO 6
KM SHEAR IS NOT IMPRESSIVE FROM EITHER MODEL...SO DO NOT EXPECT TO
SEE ANYTHING SEVERE. ANY STORMS THAT DEVELOP WILL HAVE THE POTENTIAL
FOR GUSTY WINDS GIVEN INVERTED-V PROFILES.
MOIST SOUTHWEST FLOW BECOMES BETTER ESTABLISHED ON TUE. THE INCREASE
IN MONSOONAL MOISTURE AND LARGE SCALE FORCING SHOULD PROMOTE FAIRLY
WIDESPREAD SHOWERS AND THUNDERSTORMS ACROSS THE CWA. MAINTAINED AT
LEAST SCATTERED POPS FOR MOST AREAS...HIGHEST IN THE MOUNTAINS. WEAK
FLOW ALOFT SUGGESTS LITTLE CONCERN FOR STRONGER CONVECTION DESPITE
MODERATE INSTABILITY WITH CAPES EXCEEDING 1000 J/KG. THE MODELS SHOW
THE COOLEST TEMPERATURES ALOFT ON TUE...BUT NOT MUCH DIFFERENT THAN
PREVIOUS DAYS. CONTINUED TO TREND COOLER FOR HIGHS GIVEN THAT SHOWER
ACTIVITY AND MID LEVEL CLOUD COVER SHOULD BE MORE WIDESPREAD.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 258 PM MDT SUN JUL 12 2015
MODELS TRENDING WARMER INTO THE EXTENDED FORECAST PERIOD AS
WESTERLY FLOW ALOFT DEVELOPS OVER SOUTHEAST WYOMING AND
PANHANDLE. TEMPERATURES WILL RISE INTO THE 80S OVER MUCH OF
SOUTHEAST WYOMING FROM MID WEEK INTO THE EARLY WEEKEND WITH SOME
90S INTO THE PLAINS. 90 DEGREE HIGHS LIKELY FOR THE NEBRASKA
PANHANDLE AND WOULD NOT BE SURPRISED TO SEE A SOME 100 DEGREE
READINGS LATE INTO THE WEEK IN PLACES LIKE CHADRON AND SCOTTS
BLUFF. MODELS ALSO TRENDING DRIER THROUGH THIS PERIOD WITH
WESTERLY DOWNSLOPE FLOW BECOMING MORE LIKELY.
NUMERICAL MODELS ARE STRUGGLING TO RESOLVE THE MOVEMENT OF AN
UPPER LEVEL TROUGH OVER THE PACIFIC NORTHWEST LATE IN THE WEEK.
YESTERDAYS EC AND GFS BOTH WERE SHOWING THE TROUGH MOVING ACROSS
THE NORTHERN AND CENTRAL ROCKIES THIS UPCOMING WEEKEND. LAST
NIGHTS EC AND GFS BOTH INDICATED SPLITTING ENERGY WITH A CLOSED
LOW DEVELOPING OVER THE PACIFIC NORTHWEST WITH THE REST OF THE
ENERGY MOVING INTO CENTRAL CANADA. TODAYS MODEL RUNS ARE SOMEWHERE
IN BETWEEN. THE DIFFERENCE BETWEEN THE CLOSED LOW SOLUTION AND THE
PROGRESSIVE SOLUTION IS THE DIFFERENCE BETWEEN COOL AND WET AND
HOT AND DRY RESPECTIVELY. NOT REMOTELY CONFIDENT IN ANY SOLUTION
AT THIS TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH MONDAY AFTERNOON)
VFR CONDITIONS AND LIGHT WINDS ARE EXPECTED FOR THE REST OF TONIGHT
AND INTO MONDAY FOR MOST OF SOUTHEAST WYOMING AND WESTERN NEBRASKA.
KRWL AND KLAR MAY GUST UP TO 20 KNOTS MONDAY AFTERNOON DUE TO LLVL
MIXING. OTHERWISE THUNDERSTORMS ARE EXPECTED TO DEVELOP AROUND THE
MOUNTAINS MONDAY AFTERNOON...MAINLY ALONG AND SOUTH OF I80. ADDED
VCTS FOR KLAR AND KCYS MONDAY AFTERNOON.
&&
.FIRE WEATHER...
ISSUED AT 250 PM MDT SUN JUL 12 2015
WARM AND DRY CONDITIONS WILL CONTINUE THIS AFTERNOON THROUGH MUCH OF
THE DAY ON MON. ELEVATED CONDITIONS ARE OCCURRING OVER EAST CENTRAL
WYOMING WITH HUMIDITIES NEAR 15 PERCENT AND WIND GUSTS TO 25 MPH AT
LUSK...BUT THIS SHOULD IMPROVE SHORTLY. LIGHT WINDS ARE EXPECTED ON
MON WITH MINIMUM HUMIDITIES AROUND 20 PERCENT. THE BEST CHANCE FOR
WETTING RAINS WILL ARRIVE ON TUE WITH SCATTERED TO NUMEROUS SHOWERS
AND THUNDERSTORMS LIKELY ACROSS MUCH OF THE AREA.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...MAJ
SHORT TERM...CLH
LONG TERM...SML
AVIATION...TJT
FIRE WEATHER...CLH
AREA FORECAST DISCUSSION
NWS TUCSON AZ
930 PM MST TUE JUL 14 2015
.SYNOPSIS...ADEQUATE MOISTURE WILL PROVIDE A CHANCE OF SHOWERS AND
THUNDERSTORMS MOSTLY FROM TUCSON EAST AND SOUTH THROUGH FRIDAY.
INCREASED MOISTURE FROM TROPICAL SYSTEM DOLORES SHOULD ENHANCE
RAINFALL CHANCES AREA WIDE THIS WEEKEND. NEAR NORMAL DAYTIME
TEMPERATURES WILL CONTINUE THROUGH THURSDAY FOLLOWED BY RELATIVELY
COOLER TEMPERATURES BY THIS WEEKEND.
&&
.DISCUSSION...ISOLATED STRONG STORMS LATE THIS AFTERNOON INTO THE
EARLY EVENING HOURS. ALSO HAD SOME AREAS WHERE FLOODING ISSUES WERE
ALSO A CONCERN. AS OF THIS WRITING...A FEW LIGHT SHOWERS WERE
OCCURRING ACROSS SRN COCHISE COUNTY WITH ISOLATED STORM NORTH OF
TUCSON. LATEST HRRR RUNS KEEP ISOLATED ACTIVITY DURING THE OVERNIGHT
HOURS. WILL RUN A QUICK UPDATE TO THE FORECAST FOR THE OVERNIGHT
TIME FRAME. ANOTHER ROUND OF STORMS ONCE AGAIN WEDNESDAY AFTERNOON
AND EVENING.
&&
.AVIATION...VALID THRU 16/00Z.
ISOLD -TSRA/-SHRA MAINLY EAST OF KTUS LATE TNGT INTO WED AM. CLOUD
DECKS NR STORMS MAINLY 7-11K FT OTRW DEBRIS CLOUDS WILL BE DCRSG
OVRNGT. SFC WIND OVRNGT INTO WED AM MAINLY LESS THAN 10 KTS. ANOTHER
ROUND OF TSRA/SHRA IS EXPECTED FROM KTUS EWD WED AFTN INTO THE
EVENING HOURS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS MAINLY
EAST OF FIRE WEATHER ZONE 150 THROUGH THURSDAY. BRIEF GUSTY WINDS...
LOCALLY HEAVY RAINFALL...AND FREQUENT LIGHTNING WILL OCCUR WITH THE
STRONGER THUNDERSTORMS. INCREASED MOISTURE FROM TROPICAL SYSTEM
DOLORES WILL ENHANCE RAINFALL CHANCES AREA-WIDE STARTING FRIDAY AND
LASTING THROUGH THE UPCOMING WEEKEND. A REDUCTION IN SHOWER AND
THUNDERSTORM ACTIVITY SHOULD THEN OCCUR EARLY NEXT WEEK. OUTSIDE OF
ANY AREAS OF PRECIPITATION...GENERALLY LIGHT TERRAIN DRIVEN WINDS
WILL PREVAIL WITH OCCASIONAL AFTERNOON GUSTS DUE TO DAYTIME HEATING.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1120 PM MDT TUE JUL 14 2015
.UPDATE...
ISSUED AT 550 PM MDT TUE JUL 14 2015
BUMPED UP POPS OVER FAR EASTERN PLAINS AND MENTIONED HEAVY RAIN IN
THE NDFD. /HODANISH
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 300 PM MDT TUE JUL 14 2015
UPPER LEVEL HIGH PRESSURE REMAINS CENTERED OVER TX THIS
AFTERNOON...KEEPING MOIST SSW MID LEVEL FLOW IN PLACE ACROSS
COLORADO. LOWER LEVELS HAVE CONTINUED TO MOISTEN TODAY...AS SURFACE
DEWPOINTS ARE RUNNING AROUND 10F HIGHER THAN 24 HRS AGO. OVER THE
MOUNTAINS...CAPES ARE IN THE 500-1000 J/KG RANGE...WHILE CAPE OVER
THE PLAINS ALONG THE NM AND KS BORDERS EXCEEDS 1000 J/KG. RELATIVE
MIN IN THE INSTABILITY FIELD LIES OVER EL PASO/PUEBLO/CROWLEY/OTERO
COUNTIES...WHERE DEWPOINTS HAVE DROPPED OFF INTO THE MID TO UPPER
40S...LEADING TO CAPES GENERALLY IN THE 400-800 J/KG RANGE.
CONVECTIVE STRENGTH AND COVERAGE SO FAR TODAY HAS THUS BEEN HIGHER
THAN YESTERDAY MOST AREAS...AND WITH WEAK LEE SURFACE TROUGH OVER
THE PLAINS ENHANCING LOW LEVEL WINDS SLIGHTLY...APPEARS THERE WILL
BE AT LEAST A LOW THREAT OF SEVERE STORMS OVER THE FAR EASTERN
PLAINS...AS 0-6KM SHEAR CLIMBS ABOVE 30 KTS FOR A TIME LATE THIS
AFTERNOON/EARLY THIS EVENING. WHILE WATER VAPOR LOOP SUGGESTS
STRONGEST UPPER WAVE IS FAIRLY FAR TO THE SOUTH OVER SERN
AZ...STREAM OF WEAKER WAVES EMBEDDED IN THE MOIST PLUME WILL
CONTINUE PUSH OVER THE AREA LATE THIS AFTERNOON INTO
TONIGHT...HELPING TO KEEP CONVECTION GOING PAST SUNSET...ESPECIALLY
OVER THE MOUNTAINS AND ACROSS THE FAR EASTERN PLAINS ALONG THE KS
BORDER. MESOSCALE MODELS SUPPORT THIS IDEA...WITH MAIN CLUSTER OF
CONVECTION OVER THE PLAINS THIS EVENING PUSHING INTO KS TOWARD
06Z...WITH HRRR SHOWING A SECONDARY AREA OF MOUNTAIN CONVECTION
MOVING INTO THE I-25 CORRIDOR THIS EVENING. APPEARS MOST STORMS WILL
THEN FADE AWAY BY EARLY WED MORNING...THOUGH CONVECTIVE DEBRIS
CLOUDS MAY LINGER LONG ENOUGH TO KEEP MINS RATHER MILD.
ON WEDNESDAY...MOISTURE LEVELS ACROSS THE MOUNTAINS DON`T CHANGE
VERY MUCH...LEADING TO ANOTHER ROUND OF SCATTERED CONVECTION OVER
MOST HIGH TERRAIN LOCATIONS IN THE AFTERNOON. OVER THE I-25 CORRIDOR
AND EASTERN PLAINS...MODELS SHOW LOW LEVEL WINDS BECOMING WEAKLY
WESTERLY THROUGH THE DAY...SHUNTING THE DEEPER MOISTURE AND
INSTABILITY INTO KS BY LATE AFTERNOON. STILL ENOUGH RESIDUAL
MOISTURE IN PLACE TO PRODUCE ISOLATED TO LOW END SCATTERED
CONVECTION...THOUGH EXPECT BOTH COVERAGE AND INTENSITY TO DECREASE
AS SURFACE LAYER DRIES. MAX TEMPS DRIFT DOWNWARD JUST SLIGHTLY WED
AS MID LEVEL TEMPS COOL...THOUGH READINGS MOST LOCATIONS WILL END UP
WITHIN A COUPLE DEGF OF TUESDAY`S READINGS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 300 PM MDT TUE JUL 14 2015
MODELS CONTINUE TO HAVE ISSUES IN THE EXTENDED PERIOD WITH
DIFFERENCES BETWEEN THE OPERATIONAL SOLUTIONS AND HIGH ENSEMBLE
SPREADS. BOTH THE ECMWF AND GFS ARE IN AGREEMENT THAT SOMETHING
WILL MOVE ACROSS THE AREA...BUT THERE ARE BIG DIFFERENCES IN
TIMING AND TRACK.
WEDNESDAY NIGHT...AN UPPER LEVEL DISTURBANCE WILL BE MOVING ACROSS
THE REGION WEDNESDAY EVENING AND INTO THE CENTRAL PLAINS BY
THURSDAY MORNING. MODELS CONTINUE TO DEVELOP A THUNDERSTORM
COMPLEX ACROSS THE EASTERN PLAINS AND TRACK IT EAST THROUGH THE
OVERNIGHT HOURS. THERE CONTINUE TO BE MODEL DIFFERENCES...WITH
SEVERAL SOLUTIONS ACROSS NORTHEAST COLORADO...AND OTHER OVER
SOUTHEASTERN COLORADO. THUNDERSTORMS THAT DO DEVELOP OVER THE
PLAINS WILL BE CAPABLE OF HEAVY RAINFALL AND AN ELEVATED FLASH
FLOOD RISK...ESPECIALLY WHERE THE STRONG STORMS EXIST. EXPECT
SHOWERS AND THUNDERSTORMS TO SHIFT EAST INTO KANSAS BY THURSDAY
MORNING.
THURSDAY THROUGH SATURDAY...HIGH PRESSURE IS FORECAST TO SIT OVER
TEXAS AND A TROUGH WILL REMAIN OVER THE WEST COAST WITH PERSISTENT
SOUTHWEST FLOW ACROSS COLORADO. SEVERAL EMBEDDED DISTURBANCES IN
THE FLOW WILL LEAD TO NEAR DAILY SHOWERS AND THUNDERSTORMS OVER
THE MOUNTAINS. MODEST STEERING FLOWS ALOFT WILL LIKELY HELP PUSH
THIS ACTIVITY OUT INTO THE I-25 CORRIDOR THROUGH THE EVENING HOURS
BEFORE DISSIPATING AFTER SUNSET. THUNDERSTORMS WILL BE CAPABLE OF
PRODUCING LOCALLY HEAVY RAINFALL AND STRONG THUNDERSTORM WIND
GUSTS. TEMPERATURES WILL REMAIN WARM WITH 90S ACROSS THE LOWER
ELEVATIONS.
SUNDAY THROUGH TUESDAY...MODEL DIFFERENCES BEGIN TO DIVERGE SUNDAY
INTO EARLY NEXT WEEK. BOTH THE ECMWF AND GFS RETROGRADE THE HIGH
PRESSURE FROM TEXAS INTO THE DESERT SOUTHWEST WHILE THE TROUGH
OVER THE WEST COAST EJECT TO THE EAST. THE GFS IS FURTHEST SOUTH
WITH THE UPPER TROUGH...BRINGING IT ACROSS THE AREA SUNDAY INTO
MONDAY WITH WIDESPREAD SHOWERS AND THUNDERSTORMS ACROSS THE
REGION BEFORE DRYING OUT TUESDAY. LOCALLY HEAVY RAINFALL WOULD BE
POSSIBLE WITH A CONTINUED RISK OF FLOODING. THE ECMWF BRINGS THE
UPPER TROUGH ACROSS TO THE NORTH AND SENDS A COLD FRONT ACROSS THE
AREA ON SUNDAY AFTERNOON. IT BRINGS A QUICK SHOT OF WIDESPREAD
SHOWERS AND THUNDERSTORMS TO THE AREA SUNDAY. BY MONDAY THE ECMWF
IS MUCH DRIER WITH WEAK HIGH PRESSURE BUILDING ACROSS THE AREA AND
THE MAIN ENERGY TRACK TO THE SOUTH. GIVEN THE UNCERTAINTY...HAVE
LOW POPS ACROSS THE AREA SUNDAY THROUGH TUESDAY...WITH SUNDAY AND
MONDAY POTENTIALLY BEING WET ACROSS THE AREA. MOZLEY
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1115 PM MDT TUE JUL 14 2015
VFR CONDITIONS ARE ANTICIPATED AT DURING THE NEXT 24H AT ALL 3 TAF
SITES...KPUB...KALS AND KCOS. WINDS WILL BE LIGHT AND DIURNALLY
DRIVEN. ISOLATED TSRA WILL BE POSSIBLE TOMORROW AFTERNOON AT EACH
TAF SITE...BUT PROBABILITY OF OCCURRENCE IS TOO LOW TO MENTION
EXPLICITLY IN TAF PRODUCT.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HODANISH
SHORT TERM...PETERSEN
LONG TERM...MOZLEY
AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS ALBANY NY
511 AM EDT WED JUL 15 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTHEASTWARD ACROSS THE REGION TODAY. WITH
ITS PASSAGE THE HUMID AIRMASS IN PLACE WILL BE REPLACED BY A MUCH
DRIER ONE. HIGH PRESSURE WILL BUILD IN TONIGHT AND MOVE EASTWARD
ACROSS THE REGION THURSDAY...EVENTUALLY SHIFTING OFFSHORE FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A COLD FRONT IS MOVING INTO THE LOCAL AREA FROM THE SAINT
LAWRENCE VALLEY. STORMS ARE EXPECTED TO DEVELOP AHEAD OF THE COLD
FRONT IN THE MOIST AIRMASS ACROSS THE AREA. THE ACTIVITY IS
EXPECTED TO BE MAINLY SOUTH OF THE CAPITAL DISTRICT WHERE THERE
WILL BE SOME INSTABILITY. HAVE NO MENTION OF THUNDER FROM THE
CAPITAL DISTRICT NORTHWARD. PWATS ARE HIGH AROUND 1.5 INCHES SO
ANY STORM WILL BE CAPABLE OF PRODUCING HEAVY DOWNPOURS. ALSO FLOW
ACROSS THE AREA REMAINS WEAK SO THE STORMS WILL BE SLOW MOVERS
WHICH COULD LEAD TO SOME URBAN AND POOR DRAINAGE FLOODING.
WITH THE PASSAGE OF THE BOUNDARY A MUCH DRIER AIRMASS WILL BEGIN
TO FILTER INTO THE REGION ON A NORTHERLY WIND WITH DEW POINTS
DROPPING INTO THE 50S TODAY AND EVEN INTO THE UPPER 40S ACROSS
SOUTHERN ADIRONDACKS BY THIS EVENING. ALSO CLOUDS WILL GIVE WAY TO
INCREASING SUNSHINE ESPECIALLY THIS AFTERNOON.
HIGHS TODAY WILL RANGE FROM A COOL MID/UPPER 60S ACROSS THE
WESTERN ADIRONDACKS TO THE LOWER 80S ACROSS THE MID HUDSON VALLEY
INTO NORTHWESTERN CONNECTICUT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
MUCH COOLER AND DRIER TONIGHT AS HIGH PRESSURE BUILDS IN FROM
CANADA. EXPECTING LOWS TO DROP INTO THE 40S ACROSS MAINLY THE
HIGHER TERRAIN WITH LOWER TO MID 50S ELSEWHERE. WITH LIGHT TO CALM
WIND AND MAINLY CLEAR SKIES SOME PATCHY FOG IS EXPECTED MAINLY IN
VALLEY LOCATIONS.
FAIR WEATHER THROUGH FRIDAY. THE SURFACE HIGH WILL MOVE EASTWARD
PASSING OVER THE REGION THURSDAY NIGHT AND SHIFTING OFFSHORE FRIDAY.
WHILE ALOFT THE FLOW BECOMES ZONAL ACROSS THE NORTHERN CONUS.
THURSDAY WILL BE MOSTLY SUNNY AND DRY WITH HIGHS MAINLY IN THE 70S
ABOUT 5 DEGREES BELOW NORMAL FOR MID JULY. DEW POINTS ARE EXPECTED
TO BE IN THE MID TO UPPER 40S. ANOTHER COOL NIGHT THURSDAY WITH
LOWS SIMILAR TO WEDNESDAY`S NIGHT.
FRIDAY WILL BE WARMER AS A RETURN FLOW SETS UP AS THE SURFACE HIGH
SHIFTS OFFSHORE AND DEW POINTS WILL RISE INTO THE 50S. EXPECTING
SEASONABLE HIGHS IN THE MID 70S TO LOWER 80S.
A SHORT WAVE WILL BE APPROACHING THE REGION IN THE FAST ZONAL FLOW
FRIDAY NIGHT SO CHANCES FOR SHOWERS RETURN TO THE FORECAST.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
ALTHOUGH UNSETTLED WEATHER IS EXPECTED THROUGH MUCH OF THE LONG TERM
PERIOD...PRECIP WILL BE MAINLY SCATTERED IN NATURE AND ANY ONE
PARTICULAR LOCATION WON/T SEE A LONG DURATION WASHOUT THROUGH THE
ENTIRE PERIOD.
AN UPPER LEVEL DISTURBANCE WILL SLIDE BY TO THE NORTH OF THE REGION
FOR SATURDAY INTO SATURDAY NIGHT...AND A SURFACE WARM FRONT WILL BE
SITUATED CLOSE TO THE REGION AS WELL. THE COMBINATION OF THESE TWO
FEATURES COULD ALLOW FOR THE CHANCE OF SOME SHOWERS AND
THUNDERSTORMS...WITH THE BEST CHANCE FOR NORTHERN AREAS...PRIMARILY
DURING THE DIURNALLY FAVORED AFTN AND EARLY EVENING HOURS. STILL TOO
EARLY TO SPECULATE ON JUST HOW STRONG ANY THUNDERSTORM ACTIVITY
COULD BE...AS THERE MAY BE A DECENT AMOUNT OF INSTABILITY PRESENT
THANKS TO SURFACE HEATING...ALTHOUGH 0-6 BULK SHEAR AMOUNTS LOOK
TO BE FAIRLY LIMITED. TEMPS CLOSE TO SEASONAL NORMALS...WITH HIGHS
IN THE UPPER 70S TO MID 80S...AND LOWS IN THE 60S.
HEIGHTS WILL RISE SOMEWHAT FOR SUNDAY INTO MONDAY WITH WARMING TEMPS
ALOFT. STILL...CANNOT RULE OUT A SHOWER OR THUNDERSTORM DURING THESE
DAYS...ESP FOR THE AFTN AND EVENING HOURS...THANKS TO A NEARBY
STALLED SFC FRONTAL BOUNDARY. WITH MID LEVEL LAPSE RATES ONLY AROUND
5.5 TO 6 DEGREES C/KM AND 0-6 BULK SHEAR VALUES MAINLY 25 KTS OR
LESS...IT MAY BE TOUGH FOR ANY STORMS TO GET VERY STRONG ON SUNDAY
INTO MONDAY...BUT WILL CONTINUE TO MONITOR MODEL TRENDS. HIGHS WILL
BE WARMER IN THE MID TO UPPER 80S FOR VALLEY AREAS...AND LOWS IN THE
MID TO UPPER 60S. IT WILL BE MUGGY AS WELL...WITH DEWPOINTS WELL
INTO THE 60S AS WELL.
A STRONGER UPPER LEVEL DISTURBANCE AND FRONTAL BOUNDARY LOOKS TO
CROSS THE REGION FOR MONDAY NIGHT INTO TUESDAY. THIS WILL BRING THE
BEST CHANCE DURING THE LONG TERM PERIOD OF
SHOWERS/THUNDERSTORMS...ALTHOUGH THE EXACT TIMING OF THIS FEATURE IS
STILL SOMEWHAT UNCERTAIN. WITH THE VERY HUMID CONDITIONS AHEAD OF
THIS FEATURE...THERE COULD POTENTIALLY BE SOME HEAVY RAINFALL WITH
ANY THUNDERSTORMS. TEMPS LOOK CLOSE TO SEASONAL NORMALS. DRIER AND
LESS HUMID CONDITIONS LOOK TO OCCUR TOWARDS THE MIDDLE OF THE WEEK
BEHIND THIS FEATURE WITH CONTINUED NEAR NORMAL TEMPS.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
A FRONTAL SYSTEM IS IN THE PROCESS OF MOVING ACROSS THE REGION.
AHEAD OF THIS SYSTEM...A VERY MOIST AIRMASS IS IN PLACE...ALONG
WITH SOME SCATTERED RAIN SHOWERS. ACCORDING TO RADAR TRENDS AND
THE 12KM NAM AND 3KM HRRR GUIDANCE...IT APPEARS SOUTHERN AREAS
WILL HAVE THE BEST CHANCE OF SEEING SHOWERS THROUGH THE REMAINDER
OF THE OVERNIGHT HOURS. BETWEEN CHANCE FOR PRECIP...LOW
STRATUS...AND SOME FOG OVERNIGHT...KPSF IS MOST LIKELY TO SEE AN
EXTENDED PERIOD OF IFR CONDITIONS THROUGH SUNRISE WEDNESDAY. KPOU
WILL LIKELY SEE A PERIOD OF MVFR CIGS...AND POSSIBLY A BRIEF
PERIOD OF IFR CIGS AS WELL. FURTHER NORTH...CANNOT RULE OUT SOME
MVFR CIGS FOR KGFL/KALB...BUT IFR CONDITIONS APPEARS LESS LIKELY.
WINDS WILL BE NEARLY CALM AHEAD OF THE BOUNDARY BUT CHANGE TO THE
N-NW BEHIND THE FRONTAL BOUNDARY ON WEDNESDAY MORNING. THIS WILL
ALSO END THE THREAT FOR RAIN SHOWERS...AND ALLOW CIGS TO GRADUALLY
SCT OUT BY AFTN. VFR CONDITIONS LOOK TO RETURN BEHIND THE
BOUNDARY...AND THIS WILL BE IN PLACE FOR THE REMAINDER OF
WEDNESDAY INTO WEDNESDAY NIGHT.
OUTLOOK...
THU NIGHT-FRI: NO OPERATIONAL IMPACT. NO SIG WX.
FRI NIGHT-SUN: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
SUN NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...TSRA.
MON: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
&&
.FIRE WEATHER...
A COLD FRONT WILL MOVE SOUTHEASTWARD ACROSS THE REGION TODAY. WITH
ITS PASSAGE THE HUMID AIRMASS IN PLACE WILL BE REPLACED BY A MUCH
DRIER ONE. HIGH PRESSURE WILL BUILD IN TONIGHT AND MOVE EASTWARD
ACROSS THE REGION THURSDAY...EVENTUALLY SHIFTING OFFSHORE FRIDAY.
UNSETTLED WEATHER IS EXPECTED OVER THE WEEKEND.&&
.HYDROLOGY...
A COLD FRONT WILL SOUTHEASTWARD ACROSS THE REGION TODAY WITH
STORMS EXPECTED MAINLY SOUTH OF THE CAPITAL DISTRICT. PWATS ARE
HIGH AROUND 1.5 INCHES SO ANY STORM WILL BE CAPABLE OF PRODUCING
HEAVY DOWNPOURS. ALSO FLOW ACROSS THE AREA REMAINS WEAK SO THE
STORMS WILL BE SLOW MOVERS WHICH COULD LEAD TO SOME URBAN AND POOR
DRAINAGE FLOODING.
FAIR WEATHER EXPECTED TONIGHT THROUGH FRIDAY AS HIGH PRESSURE
DOMINATES. UNSETTLED WEATHER EXPECTED OVER THE WEEKEND WITH
PRECIPITATION MAINLY SCATTERED IN NATURE.
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.
&&
.EQUIPMENT...
OUR RADAR /KENX/ IS OUT OF SERVICE WITH PARTS ON EMERGENCY ORDER.
THE RADAR IS EXPECTED TO BE DOWN AT LEAST INTO THIS AFTERNOON.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA
NEAR TERM...IAA
SHORT TERM...IAA
LONG TERM...FRUGIS
AVIATION...FRUGIS
FIRE WEATHER...IAA
HYDROLOGY...IAA
EQUIPMENT...ALY STAFF
AREA FORECAST DISCUSSION
NWS ALBANY NY
148 AM EDT WED JUL 15 2015
.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL PASS TO OUR SOUTH AS A COLD FRONT
MOVES SOUTHEASTWARD ACROSS THE REGION WEDNESDAY. THIS WILL KEEP
THE WEATHER UNSETTLED ACROSS THE AREA WITH BETTER CHANCES FOR
STORMS TO THE SOUTH AND EAST OF THE CAPITAL DISTRICT. CANADIAN
HIGH PRESSURE WILL BRING A RETURN TO DRY WEATHER WEDNESDAY NIGHT
THROUGH FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
SHOWERS ARE OCCURRING MAINLY TO THE WEST OF THE HUDSON RIVER VALLEY
ACROSS A PORTION OF THE SOUTHERN ADIRONDACKS AND EASTERN CATSKILLS.
THE MESOSCALE MODELS ARE NOT HANDLING CURRENT CONVECTION WELL
HOWEVER THE OVERALL TREND IS THAT THE CONVECTION WILL WEAKEN AS IT
MOVES EASTWARD. WITH A SURFACE LOW PASSING TO OUR SOUTH AND A COLD
FRONT OVER THE SAINT LAWRENCE RIVER VALLEY AND HEADING SOUTHEASTWARD
HAVE MAINTAINED POPS ACROSS AREA OVERNIGHT.
MUGGY NIGHT WITH OVERNIGHT LOWS MAINLY IN THE 60S WITH DEW POINTS
IN 60S AS WELL.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
BY EARLY WEDNESDAY...THE SURFACE COLD FRONT SHOULD HAVE SLIPPED SOUTH
OF I-90. HOWEVER...THE UPPER LEVEL TROUGH MIGHT LAG A LITTLE
BEHIND...KEEPING THINGS UNSETTLED INITIALLY...EVEN NORTH OF THE
FRONT. THE DAY WILL START WITH PLENTY OF CLOUDS AND CHANCES FOR
SHOWERS FROM ALBANY NORTH...WHILE FURTHER SOUTH SHOWERS WILL BE LIKELY
WITH STILL THE CHANCE FOR THUNDERSTORMS.
BY MIDDAY...CLOUDS SHOULD BEGIN TO CLEAR IN OUR NORTHERN AREAS...REACHING
IN THE CAPITAL REGION DURING THE AFTERNOON. IT MIGHT REMAIN MOSTLY
CLOUDY WITH RESIDUAL SHOWERS AND POSSIBLY ANOTHER THUNDERSTORM IN
OUR SOUTHERN AREAS MUCH OF THE AFTERNOON.
BASED ON UPSTREAM OBS AND LOTS OF CLOUDS TOMORROW...IT WILL TURN
NOTICEABLY COOLER BEHIND THE FRONT WITH A NORTHERLY BREEZE KICKING
IN. WHILE NOT GOING AS LOW AS THE MET GUIDANCE WE ACTUALLY SIDED A
LITTLE MORE WITH IT...THAN THE WARMER MAV NUMBERS. THAT MEANS HIGHS WILL
ONLY REACH AROUND 70 IN OUR NORTHERN ZONES (DESPITE SEEING SOME
CLEARING EARLIER)...MID 70S CAPITAL REGION AND NEAR 80 SOUTH WHERE
THE FRONT AGAIN WILL BE LAST TO CLEAR. DEWPOINTS LOOK TO PLUNGE TO
THE 40S NORTH AND WEST OF ALBANY DURING THE AFTERNOON...50S LOCALLY IN THE
CAPITAL REGION. TO THE SOUTH...DEWPOINTS STARTING OUT NEAR 70...WILL
BE TRIMMED BACK TO THE 60S BY LATE IN THE DAY.
A NORTHERLY BREEZE WILL KICK IN AROUND 10 MPH...BUT COULD GUST OVER
20 MPH AT TIMES.
BY WEDNESDAY NIGHT...A MUCH DRIER AIRMASS WILL WORK IN
EVERYWHERE...CLEARING THE SKY AND MAKING FOR A REFRESHINGLY COOLER
NIGHT. A LIGHT NORTH BREEZE WILL CONTINUE IN MOST AREAS. OVERNIGHT
LOWS LOOK TO DROP INTO THE LOWER TO MID 50S ACROSS MOST AREAS...BUT
DOWN INTO THE MID TO UPPER 40S ACROSS OUR NORTHERN AREAS.
THURSDAY LOOKS LIKE A BEAUTIFUL DAY WITH A FEW CU FORMING. OTHERWISE
IT WILL BE SUNNY WITH RATHER LOW HUMIDITY (DEWPOINTS FROM THE MID
40S TO LOWER 50S) AND HIGH TEMPERATURES 75-80 IN THE VALLEYS...70-75
HIGHER TERRAIN.
THURSDAY NIGHT HIGH PRESSURE WILL CREST OVER THE REGION BRINGING
ANOTHER MAINLY CLEAR AND COOL NIGHT. LOOK FOR LOWS AGAIN LOWER TO
MID 50S ALBANY SOUTH...MID TO UPPER 40S MOST OTHER AREAS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE EXTENDED FORECAST OPENS WITH DRY WEATHER TO CLOSE THE
WORK WEEK...AS A SFC ANTICYCLONE DRIFTS EAST OF NEW ENGLAND BY THE
AFTERNOON. THE CLOSED H500 ANTICYCLONE CONTINUES TO BE CENTERED
NEAR TX...AND THE LOWER MS RIVER VALLEY. THE NRN PERIPHERY OF THE
MID LEVEL RIDGE CONTINUES TO HAVE FLAT RELATIVELY FAST FLOW ALOFT AS
WE ENTER THE WEEKEND. A LOW PRESSURE SYSTEM WILL BE MOVING ACROSS
THE UPPER MIDWEST AND WRN GREAT LAKES REGION FRIDAY AFTERNOON. A
WARM FRONT EXTENDING EAST/SOUTHEAST OF THE WAVE WILL ALLOW MID AND
HIGH CLOUDS TO INCREASE FROM THE WEST LATE IN DAY...AND INTO THE
NIGHT PERIOD. THE GFS/ECMWF/WPC GUIDANCE CONTINUE TO HAVE SOME
ISOLD-SCT SHOWERS AND PERHAPS SOME ISOLD THUNDERSTORM INCREASING
FROM WEST TO EAST OVER THE FCST AREA...ESPECIALLY AFTER MIDNIGHT DUE
TO THE WEAK ISENTROPIC LIFT AHEAD OF THE BOUNDARY. THE BETTER CHC
OF SHOWERS AND ISOLD THUNDERSTORMS LOOKS TO BE NORTH AND WEST OF THE
CAPITAL DISTRICT AND MID HUDSON VALLEY. HIGHS ON FRIDAY WILL BE IN
THE U70S TO L80S IN THE VALLEY AREAS...AND 70S OVER THE MTNS. LOWS
FRI NIGHT WILL RANGE FROM THE MID 50S TO L60S OVER THE FCST AREA.
SAT-SAT NIGHT...THE FIRST WEAK SFC LOW LIFTS NORTH AND EAST OF THE
REGION...AND THE WARM FRONT MAY LIFT NORTH OF MOST OF THE FCST AREA.
IN THE WARM SECTOR...SFC DEWPTS MAY GET WELL INTO THE 60S. MODERATE
AMOUNTS OF SFC BASED INSTABILITY MAY SET UP OVER THE FCST AREA IF
ENOUGH HEATING OCCURS. THE LATEST GFS HAS SBCAPES OF 1000-2000 J/KG
FROM ABOUT THE HUDSON RIVER VALLEY WESTWARD BY 00Z/SUN. SOME STRONG
THUNDERSTORMS WITH HEAVY RAINFALL WILL BE POSSIBLE AS PWATS MAY RISE
A STANDARD DEVIATION OR SO ABOVE NORMAL. CHANCES OF SHOWERS AND
THUNDERSTORMS ARE POSSIBLE ESPECIALLY SATURDAY AFTERNOON INTO THE
EARLY EVENING WITH HIGHS IN THE M70S TO L80S OVER THE FCST AREA.
EXPECTING THE SHOWERS AND THUNDERSTORMS TO DECREASE OVERNIGHT WITH
MUGGY CONDITIONS WITH LOWS IN THE 60S. THE WEAK SYSTEM LIFTS NORTH
AND EAST...AND THE COLD FRONT LOOKS TO WASH OUT NEAR THE FCST AREA.
SUNDAY INTO TUESDAY...THE H500 RIDGE CENTERED OVER THE SRN
PLAINS/SOUTHEAST MAY AMPLIFY A BIT AS WE CLOSE THE WEEKEND. THIS
WILL ALLOW THE OLD COLD FRONT TO MOVE BACK NORTH AND EAST OF UPSTATE
NY AND NEW ENGLAND AS A WARM FRONT. THE ECMWF ACTUALLY SHOWS A
RELATIVELY DRY SUNDAY...WITH THE NEXT DISTURBANCE APPROACHING FROM
THE GREAT LAKES REGION. THE GFS/CMC/ENSEMBLES AND WPC GUIDANCE
INDICATE MORE SHOWERS AND THUNDERSTORMS MAY OCCUR ALONG AND BEHIND
THE WARM FRONT. A CHC OF SHOWERS AND THUNDERSTORM WAS KEPT IN THE
FCST TO CLOSE THE WEEKEND. TEMPS MAY NUDGE A TAD ABOVE NORMAL WITH
MID AND U80S IN THE VALLEYS...AND U70S TO L80S OVER THE HIGHER
PEAKS. SCATTERED SHOWERS PERSIST INTO THE EARLY EVENING...AS
A STICKY AIR MASS CONTINUES OVER THE FCST AREA.
MONDAY MAY FEATURE AIR MASS OR DIFFERENTIAL HEATING ISOLD-SCT
THUNDERSTORMS TIED TO THE PEAK DIURNAL HEATING WELL IN ADVANCE OF
THE NEXT SYSTEM APPROACHING FROM THE GREAT LAKES REGION. IT MAY NOT
BE A COMPLETE WASHOUT. A PROGRESSIVE NRN STREAM TROUGH WILL BE
MOVING OVER THE NRN GREAT LAKES REGION AND S-CNTRL ONTARIO MON NIGHT
INTO TUESDAY. THERE IS A BETTER CHC OF SCT SHOWERS AND
THUNDERSTORMS AHEAD OF THE COLD FRONT AND A PREFRONTAL SFC TROUGH.
SOME HEAVY LOCALLY HEAVY RAINFALL WILL BE POSSIBLE WITH PWATS
POTENTIALLY 1-2 STD DEVS ABOVE NORMAL ON THE GEFS AS WE HEAD INTO
EARLY NEXT WEEK. HIGHS AND LOWS STILL LOOK A LITTLE ABOVE NORMAL AS
WE MOVE INTO EARLY NEXT WEEK.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
A FRONTAL SYSTEM IS IN THE PROCESS OF MOVING ACROSS THE REGION.
AHEAD OF THIS SYSTEM...A VERY MOIST AIRMASS IS IN PLACE...ALONG
WITH SOME SCATTERED RAIN SHOWERS. ACCORDING TO RADAR TRENDS AND
THE 12KM NAM AND 3KM HRRR GUIDANCE...IT APPEARS SOUTHERN AREAS
WILL HAVE THE BEST CHANCE OF SEEING SHOWERS THROUGH THE REMAINDER
OF THE OVERNIGHT HOURS. BETWEEN CHANCE FOR PRECIP...LOW
STRATUS...AND SOME FOG OVERNIGHT...KPSF IS MOST LIKELY TO SEE AN
EXTENDED PERIOD OF IFR CONDITIONS THROUGH SUNRISE WEDNESDAY. KPOU
WILL LIKELY SEE A PERIOD OF MVFR CIGS...AND POSSIBLY A BRIEF
PERIOD OF IFR CIGS AS WELL. FURTHER NORTH...CANNOT RULE OUT SOME
MVFR CIGS FOR KGFL/KALB...BUT IFR CONDITIONS APPEARS LESS LIKELY.
WINDS WILL BE NEARLY CALM AHEAD OF THE BOUNDARY BUT CHANGE TO THE
N-NW BEHIND THE FRONTAL BOUNDARY ON WEDNESDAY MORNING. THIS WILL
ALSO END THE THREAT FOR RAIN SHOWERS...AND ALLOW CIGS TO GRADUALLY
SCT OUT BY AFTN. VFR CONDITIONS LOOK TO RETURN BEHIND THE
BOUNDARY...AND THIS WILL BE IN PLACE FOR THE REMAINDER OF
WEDNESDAY INTO WEDNESDAY NIGHT.
OUTLOOK...
THURSDAY INTO FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF
SHRA...TSRA.
SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF
SHRA...TSRA.
SATURDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF
SHRA...TSRA.
SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF
SHRA...TSRA.
SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF
SHRA.
MONDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
&&
.FIRE WEATHER...
MOST AREAS SHOULD SEE SOME SHOWERS AND POSSIBLY A
THUNDERSTORM TONIGHT INTO EARLY WEDNESDAY WITH AVERAGE RAINFALL
GENERALLY A QUARTER INCH OR MORE...WHILE SOME AREAS LOCALLY RECEIVING UP TO
AN INCH OR MORE.
A COOLER DRIER CANADIAN AIR MASS WILL BEGIN TO TAKE HOLD LATER
WEDNESDAY AND ESPECIALLY WEDNESDAY NIGHT. DRY WEATHER IS
EXPECTED THURSDAY AND FRIDAY. TEMPERATURES WILL BE A LITTLE LOWER
THAN NORMAL ON THURSDAY...TRENDING TOWARD SEASONAL ON FRIDAY.
THE NEXT CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE SATURDAY.
&&
.HYDROLOGY...
A BROAD AREA OF LOW PRESSURE WILL MOVE SLOWLY EASTWARD ACROSS THE
REGION THROUGH WEDNESDAY. IN THE MEANTIME...A COLD FRONT WILL
APPROACH FROM THE NORTHWEST AND WILL CROSS THE REGION WEDNESDAY.
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL OCCUR AS THESE
FEATURES MOVE ACROSS THE REGION.
AVERAGE BASIN RAINFALL AMOUNTS WILL BE FROM A QUARTER TO THREE
QUARTERS OF AN INCH...BUT THERE WILL BE LOCALIZED AREAS POSSIBLY
EXCEEDING AN INCH.
WITH PWATS MAXING OUT BETWEEN 1.5-2 INCHES...ANY SHOWER OR THUNDERSTORM
COULD PRODUCE ENOUGH RAINFALL TO PRODUCE LOCALIZED PONDING OF
WATER ON ROADWAYS PERHAPS EVEN SOME URBAN FLOODING.
DRIER WEATHER RETURNS LATER WEDNESDAY INTO FRIDAY WITH THE NEXT
CHANCE OF SHOWERS AND THUNDERSTORMS RETURNING ON SATURDAY.
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.
&&
.EQUIPMENT...
OUR RADAR /KENX/ IS DOWN UNTIL WEDNESDAY AFTERNOON...AND
EMERGENCY PARTS ARE ON ORDER. WE APOLOGIZE FOR THE INCONVENIENCE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA/HWJIV/BGM
NEAR TERM...HWJIV/BGM
SHORT TERM...HWJIV
LONG TERM...WASULA
AVIATION...FRUGIS
FIRE WEATHER...HWJIV
HYDROLOGY...IAA/HWJIV
EQUIPMENT...WFO ALY STAFF
AREA FORECAST DISCUSSION
NWS NEW YORK NY
142 AM EDT WED JUL 15 2015
.SYNOPSIS...
A WARM FRONT REMAINS TO THE SOUTH OVERNIGHT...AS LOW PRESSURE
WILL BE APPROACHING LATE TONIGHT AND PASSES TO THE SOUTH
WEDNESDAY. THIS LOW MOVES SOUTHEAST OF LONG ISLAND WEDNESDAY NIGHT
AS A CANADIAN HIGH BUILDS IN FROM THE NORTHWEST. THIS HIGH
CONTINUES TO GRADUALLY BUILD CLOSER TO THE LOCAL REGION THROUGH
FRIDAY. A WARM FRONT WILL MOVE TOWARD THE AREA FRIDAY NIGHT INTO
SATURDAY MORNING AND REMAIN NEAR THE AREA THROUGH SATURDAY NIGHT.
THE WARM FRONT LIFTS WELL NORTH OF THE AREA SUNDAY NIGHT INTO
MONDAY. A COLD FRONT SLOWLY APPROACHES THE AREA FOR THE BEGINNING
OF THE NEW WORK WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
LATEST RADAR TRENDS 00Z NAM ALONG WITH LATEST RUC AND HRRR SUPPORT
EARLY CHANGE TO MAINLY DRY FORECAST FOR THE REMAINDER OF TONIGHT.
IT APPEARS THAT NEGATIVE VORTICITY ADVECTION AT 700-500 HPA WILL
BE THE DOMINATE PLAYER. THUS...HAVE REDUCED POPS LATE TONIGHT TO
20 PERCENT AND SCALED BACK TO ONLY W 1/4 OF CWA (MAINLY W OF
HUDSON). MIGHT SEE SOME SHOWERS MOVE INTO W ORANGE COUNTY
AROUND/JUST AFTER 6Z...HOWEVER CONFIDENCE IN THIS IS NOT HIGH AS
HRRR APPEARS TO HAVE OVERDONE INITIAL STRENGTH/COVERAGE OF THE
CONVECTION IT IS MOVING THERE.
LOWS GENERALLY ON TRACK...WITH MAINLY UPPER 60S N TO LOWER 70S S.
UPDATED WITH BLEND OF 00Z NAM 2-METER TEMPERATURES 18Z MAV
GUIDANCE 1Z LAV AND 12Z MET GUIDANCE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY/...
THERE ARE SOME INDICATIONS THAT PRECIPITATION MAY NOT DEVELOP
UNTIL LATER WEDNESDAY MORNING THAN CURRENTLY FORECAST. WILL WAIT
FOR ENTIRE 00Z SUITE TO COME IN BEFORE CHANGING FORECAST.
WEDNESDAY...A VERY ACTIVE DAY IN TERMS OF CONVECTION ESPECIALLY
BY MIDDAY. MORE ELEVATED INSTABILITY EXISTS EARLY WITH THE WARM
AND MOIST AIR ADVECTION WITH THE NOSE OF THE LOW LEVEL JET WITHIN
THE REGION. THE LOW LEVEL JET EXITS BY THE AFTERNOON AND THEN WITH
A LIGHT NE FLOW AT THE SURFACE...THERE WILL BE SOME LINGERING
SHOWERS AND THUNDERSTORMS...BUT WOULD EXPECT THE THUNDERSTORMS TO
BE WIDELY SCATTERED AT THAT POINT.
LAYER PRECIPITABLE WATERS WILL BE LOWERING FROM NW TO SE LATER BY
WEDNESDAY EVENING. SHOWERS WILL TAPER OFF FROM NW TO SE WEDNESDAY
NIGHT.
FOR HIGHS WEDNESDAY...CHOSE RELATIVELY COOLER MET/ECS GUIDANCE AND
LOWS WEDNESDAY NIGHT...CHOSE THIS BLEND AGAIN.
FOR THURSDAY THROUGH FRIDAY...A MORE QUIET AND TRANQUIL WEATHER
PATTERN IS CONVEYED BY THE MORE ZONAL FLOW GETTING ESTABLISHED IN
THE MID LEVELS WITH OVERALL...RIDGING IN MID TO UPPER LEVELS. AT
THE SURFACE...HIGH PRESSURE WILL GRADUALLY BUILD IN FROM THE GREAT
LAKES AND SOUTHEAST CANADA. DEWPOINTS WILL TREND LOWER...MAINLY IN
THE 50S...SO A MUCH LESS HUMID AIRMASS WILL BE ENTERING THE AREA.
FOR TEMPERATURES...USED MOSTLY ECE GUIDANCE WITH SOME BLENDING OF
GMOS FOR THURSDAY NIGHT AND FRIDAY.
THERE IS A MODERATE RISK FOR THE METEOROLOGICAL ENHANCEMENT OF RIP
CURRENT DEVELOPMENT AT ATLANTIC BEACHES WEDNESDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
ZONAL FLOW ALOFT FRIDAY NIGHT WILL BE REPLACED BY A WEAK SHORTWAVE
THAT WILL MOVE ACROSS THE NORTHEAST FRIDAY NIGHT INTO SATURDAY
NIGHT. THEREAFTER...AN UPPER LEVEL LONGWAVE TROUGH WILL APPROACH
FROM THE MID-WEST AND GREAT LAKES REGION INTO THE BEGINNING OF THE
NEW WORK WEEK. THERE IS UNCERTAINTY WITH THE AMPLITUDE OF THIS
TROUGH AS THE 12Z ECMWF IS MUCH MORE AMPLIFIED THAN THE 12Z GFS.
THIS WILL FEED INTO THE UNCERTAINTY WITH THE SURFACE FEATURES
THROUGH THIS TIME PERIOD.
AT THE SURFACE...A WARM FRONT WILL LIFT TOWARD THE REGION FRIDAY
NIGHT...AND REMAIN NEAR THE AREA SUNDAY MORNING. THE WARM FRONT
WILL THEN LIFT WELL NORTH OF THE AREA SUNDAY INTO SUNDAY NIGHT.
THEREAFTER...THE ASSOCIATED COLD FRONT WILL APPROACH INTO THE
BEGINNING OF THE NEW WORK WEEK. THE MORE AMPLIFIED UPPER LEVEL
TROUGH IN THE 12Z ECMWF MOVES THE COLD FRONT FASTER THAN THE LESS
AMPLIFIED 12Z GFS. GIVEN THE LARGE UNCERTAINTY...WILL SIDE HEAVILY
ON WPC IN THIS TIME FRAME.
SEASONABLE...BUT WARMING TEMPERATURES THROUGH THE PERIOD AS THE WARM
FRONT INTRODUCES A WARM AND HUMID AIRMASS...WITH THE AREA ALSO BEING
WARM SECTORED FOR SUNDAY AND MONDAY.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
A WARM FRONT IS LOCATED ACROSS THE FORECAST AREA...MAINLY FROM
KEWR...TO KBDR TO JUST SOUTH OF KPVD. THIS FRONT WILL REMAIN
NEARLY STATIONARY TONIGHT AS LOW PRESSURE OVER PENNSYLVANIA TRACKS
SOUTHEAST TO THE SOUTHERN NEW JERSEY COAST BY MORNING. THIS LOW
WILL THEN CONTINUE EASTWARD ON WEDNESDAY.
CIGS AND VSBYS VARY ACROSS THE REGION FROM VFR TO SUB IFR.
THINKING THAT CONDITIONS WILL LOWER A BIT OVERNIGHT TO MVFR OR
LESS THROUGH ABOUT 15Z. ALL 00Z FORECAST GUIDANCE HINTING THAT
MOST TERMINALS BECOME VFR LATE MORNING EARLY AFTERNOON. WITH THE
FRONT NORTH OF LONG ISLAND...THINKING A PERIOD OF VFR MAY BE
LIKELY.
WITH RESPECT TO PRECIPITATION...WILL CONTINUE TO WATCH SHRA/TSTM
ACTIVITY IN CENTRAL PA WHICH IS TRACKING NE. MOST OF THE AREA
SHOULD REMAIN DRY THROUGH 12Z...HOWEVER FAR WESTERN TERMINALS MAY
BE IMPACTED. OTHERWISE...EXPECT MOSTLY DRY CONDITIONS...BUT CAN
NOT RULE OUT A STRAY SHOWER/TSTM WITH THE FRONT IN THE AREA.
PRECIPITATION BECOMES MORE NUMEROUS THIS MORNING AND AFTERNOON.
THUNDERSTORMS WILL BE POSSIBLE...BUT TOO FAR OUT TO INCLUDE IN THE
TAFS AND WOULD LIKE TO GET A BETTER HANDLE ON TIMING OF
PRECIPITATION FIRST.
MODERATE TO HIGH CONFIDENCE IN WINDS.
.OUTLOOK FOR 00Z WED THROUGH SAT...
.WED NIGHT...VFR CONDS RETURNING IN THE EVE.
.THU-FRI...VFR.
.SAT...MVFR OR LOWER POSSIBLE IN SCT SHRA/TSRA.
&&
.MARINE...
MADE MINOR CHANGES THIS UPDATE. THE FORECAST APPEARS ON TRACK.
SUB SCA CONDITIONS ARE EXPECTED TO CONTINUE ACROSS ALL WATERS
WITH A RELATIVELY WEAK PRESSURE GRADIENT IN PLACE THROUGH TONIGHT.
A SE SWELL BUILDING WEDNESDAY WILL EVENTUALLY LEAD TO HIGHER SEAS
IN ADDITION TO THE CONTINUED SOUTHERLY FETCH FOR WEDNESDAY
AFTERNOON...FROM EAST TO WEST. WESTERN OCEAN WILL NOT GET TO SCA
RANGE UNTIL WEDNESDAY EVENING. OVERALL...PRESSURE GRADIENT
INCREASE BEHIND THE LOW WEDNESDAY NIGHT AND NORTHERLY WINDS WILL
INCREASE TO 15-23 KT WITH GUSTS A FEW KT HIGHER. SCA MORE
PROBABLE FOR BOTH WINDS AND SEAS WEDNESDAY NIGHT ACROSS ALL OCEAN.
THESE SCA OCEAN CONDITIONS MAY POTENTIALLY CONTINUE INTO THURSDAY
AND THURSDAY EVENING BUT WITH SOME UNCERTAINTY...DID NOT WANT TO
EXTEND SCA YET. THE SEAS WILL BE MAIN DETERMINANT HERE.
SUB SCA CONDITIONS EXPECTED LATE THURSDAY NIGHT AND FRIDAY WITH A
WEAK PRESSURE GRADIENT WITH HIGH PRESSURE TAKING CONTROL.
NON OCEAN WATERS EXPECTED TO STAY MOSTLY BELOW SCA THROUGH FRIDAY.
WINDS AND WAVES SHOULD REMAIN BELOW SCA CRITERIA FROM FRIDAY NIGHT
THROUGH THE END OF THE LONG TERM.
&&
.HYDROLOGY...
A BASIN AVERAGE OF 1/2-3/4 INCH OF RAINFALL THROUGH WEDNESDAY
NIGHT. DUE TO THE CONVECTIVE NATURE AND RELATIVELY SLOW FORWARD
MOTION OF SHOWERS DURING THIS PERIOD...FAIRLY LARGE DEVIATIONS
FROM THIS AVERAGE WILL PROBABLY OCCUR. PINPOINTING LOCATIONS THAT
WILL RECEIVE THE GREATEST AMOUNTS...AND HOW MUCH ABOVE THE BASIN
AVERAGE THOSE LOCATIONS WOULD RECEIVE IS DIFFICULT WITH THIS
SETUP.
WHAT IS SOMEWHAT MORE CERTAIN IS THAT THE BETTER CHANCES OF
WIDESPREAD RAINFALL ACROSS THE TRI STATE AREA OCCUR LATE TONIGHT
AND WEDNESDAY. THERE WILL PROBABLY BE A FEW AREAS OF MINOR
URBAN/SMALL STREAM/POOR DRAINAGE FLOODING...BUT CONFIDENCE IN A
WIDESPREAD FLASH FLOODING SCENARIO IS TOO LOW TO GO WITH ANY WATCH
AT THIS TIME. WITH THAT SAID...LOCALIZED FLASH FLOODING WILL BE
POSSIBLE AT ANY TIME TODAY THROUGH WEDNESDAY AFTERNOON.
NO HYDROLOGIC PROBLEMS EXPECTED WEDNESDAY NIGHT THROUGH THE END OF
THE WEEK.
SCATTERED SHOWERS AND THUNDERSTORMS ARE IN THE FORECAST FOR THE
WEEKEND AND EARLY NEXT WEEK. A WIDESPREAD RAINFALL IS NOT EXPECTED.
ANY SLOW MOVING SHOWER OR THUNDERSTORM COULD PRODUCE HEAVY RAIN WITH
ISOLATED FLOODING.
&&
.TIDES/COASTAL FLOODING...
SOME TIDAL LOCATIONS ALONG WESTERN LONG ISLAND SOUND AND SOUTH
SHORE BAYS WILL PROBABLY TOUCH MINOR BENCHMARKS WITH THE CONTINUED
SOUTHEAST FETCH DURING HIGH TIDES OVERNIGHT.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 6 AM EDT
THURSDAY FOR ANZ355.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 6 AM EDT
THURSDAY FOR ANZ350-353.
&&
$$
SYNOPSIS...MALOIT/JM/JP
NEAR TERM...MALOIT
SHORT TERM...MALOIT/JM
LONG TERM...JP
AVIATION...BC/24
MARINE...MALOIT/JM/JP
HYDROLOGY...MALOIT/JM/JP
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
424 AM EDT WED JUL 15 2015
...Severe Storms Possible Today...
.Near Term [Through Today]...
An earlier convective line that pushed south across the northern
half of Alabama and Georgia diminished earlier tonight. However,
its effects on the boundary layer are still being observed with
a fairly expansive cold pool across the same areas - temperatures
around 70 degrees with dew points in the upper 60s. Meanwhile,
further south over our area, low-level moisture has pooled and
dew points are in the mid-upper 70s, and even into the low 80s in
some spots. Thus, the environment over our forecast area remains
relatively undisturbed and quite unstable. This is expected to set
up an active day with respect to convective activity.
Both hi-res and global models indicate considerable convective
development early this morning (10-15Z) across the far
northeastern Gulf of Mexico and into the Florida Big Bend. The
latest objective RAP analysis at 07Z indicated MLCAPE hovering
around 2500 j/kg with very little CINH over our coastal waters,
and regional radars did show some scattered convection already
developing. Hi-res models forecast thunderstorms to become quite
numerous south of a Mexico Beach to Valdosta line in the early-to-
mid morning, particularly over Taylor, Dixie, and Lafayette
Counties. PoPs were increased to 60-70% in those areas. With
precipitable water values analyzed over 2 inches, the storms could
be efficient rain producers, and hi-res models suggest some
potential for training echoes. Therefore, locally heavy rainfall
and flooding can`t be ruled out and heavy rainfall wording was
inserted into the morning forecast. The hi-res models are also
explicitly forecasting some 35-50 knot gusts, so some of the
storms may produce gusty winds as well.
The focus will then turn to the north for the afternoon and early
evening. Additional showers and storms may develop in the early-
mid afternoon along the sea breeze and/or periphery of the upper
level cloud shield associated with the morning convection.
Additionally, a cold front currently situated over Kentucky is
expected to arrive in central Alabama and central Georgia by
21-00Z. Hi-res and global models are in excellent agreement with
initiating another round of storms along that front, possibly
coalescing into one or more convective clusters/lines and then
propagating to the south into our forecast area. Those organized
linear storms, as well as any scattered early-mid afternoon storms
in areas of stronger heating across our forecast area, would pose
a risk of damaging wind gusts. NAM- and WRF-based models also show
an increase in low-level shear as surface and near-surface winds
back to the southwest and increase with the approach of the front.
Other models are less keen on that scenario, but if it were to
unfold that way there would likely be a greater threat for
organized severe storms.
.Short Term [Tonight Through Friday]...
There is a higher than normal degree of agreement among the
plethora of CAMs we have been looking at this morning that
convection will linger well into the evening hours. The latest
ECAM came in with likely PoPs across most of the region after 00Z.
While the overall severe threat will eventually diurnally ebb, the
atmosphere should remain sufficiently unstable for a threat to
last perhaps as late as midnight. Enhanced wording was maintained
in the weather grids through 04Z. Some graphics are being prepared
that will highlight the severe weather risk for today and tonight.
A surface cold front will settle to a position just north of the
forecast area on Thursday morning and may actually dip into our
northernmost zones. This boundary will couple with residual TS
outflow boundaries and the sea breeze to trigger convection in a
very unstable environment. Marginally severe storms are expected
with wind/hail the primary threat. The current PoP for Thursday is
roughly 40-50%, but the latest ECAM came in with 80-90% PoPs south
of U.S. 84, so we would expect the official forecast to trend
upward in later packages. The remnant front will remain in the
vicinity on Friday with somewhat drier air working into our
northern zones. PoPs will be slightly lower north than south.
Temps will be running a couple of degrees above normal by day and
several degrees above at night.
.Long Term [Friday Night Through Wednesday]...
The eastern upper level trough will lift eastward during this
period which should allow the ridge to edge closer to the
region. This will bring another uptick in daytime temps. There
will be a surface through in the vicinity at least through the
weekend, and of course there will be the typical mesoscale
boundaries around to trigger convection each day. Daytime PoPs
will generally hover in the 35-45% range through the period.
&&
.Aviation...
[Through 06Z Thursday] Scattered to numerous showers and storms
are expected today, and may arrive in a couple rounds. Early-mid
morning storms are likely to be concentrated further south and
closer to the Gulf of Mexico, so ECP and TLH would be most likely
to be impacted. After that, scattered afternoon storms will be
possible at all terminals. Between 21Z and 03Z, more organized
lines of storms may push across the area from north to south. DHN
and ABY would be most likely to be affected by those more
organized storms, and gusty winds would be a possibility. A TEMPO
group was added at DHN and ABY with gusts up to 35 knots. Outside
of thunderstorms, VFR conditions should generally prevail.
&&
.Marine...
The pressure gradient across the northeastern Gulf of Mexico will
remain tighter than is typical for mid summer. The result will be
a continuation of WSW winds around 15 knots, occasionally
increasing to cautionary levels through Thursday night. Conditions
will be unsettled over the waters during this time with a few
rounds of strong to severe storms possible. By Friday, winds will
finally drop back to seasonal speeds with daily enhancements each
afternoon and evening in the sea breeze.
&&
.Fire Weather...
Hazardous fire weather conditions are not expected over the next
several days.
&&
.Hydrology...
Area rivers remain well below action stage and we do not
anticipate any main stem concerns. That said, some localized
flooding will be possible due to training of thunderstorms over
the next couple of days. While most areas will get lower amounts,
several inches of rain will be possible in localized areas.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 93 77 94 77 96 / 50 30 50 30 40
Panama City 88 80 89 80 90 / 30 30 40 30 40
Dothan 97 76 96 76 98 / 40 50 40 20 30
Albany 96 75 95 75 96 / 60 60 30 20 30
Valdosta 94 75 94 75 96 / 50 40 40 30 40
Cross City 88 76 91 76 93 / 60 40 50 30 40
Apalachicola 89 80 92 80 93 / 70 30 40 30 30
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AL...NONE.
GM...NONE.
&&
$$
NEAR TERM...LAMERS
SHORT TERM...WOOL
LONG TERM...WOOL
AVIATION...LAMERS
MARINE...WOOL
FIRE WEATHER...WOOL
HYDROLOGY...WOOL
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
330 AM EDT WED JUL 15 2015
.SHORT TERM /TODAY THROUGH THURSDAY/...
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A WEAKENING COMPLEX WILL
GRAZE NORTHERN GA EARLY THIS MORNING. SATELLITE TRENDS SHOW A
GENERAL WARMING OF TOPS AND A DECREASE IN LIGHTNING. ATMOS FOR THE
NORTHERN HALF OF THE CWFA WAS WORKED OVER PRETTY WELL LAST EVENING
WHEN A STRONGER THUNDERSTORM COMPLEX MOVED ACROSS THE AREA. A FEW
RUMBLES OF THUNDER ARE POSSIBLE THIS MORNING ACROSS THE NORTH...BUT
SEVERE WEATHER IS NOT ANTICIPATED.
A WEAK FRONT/TROUGH WILL MOVE SOUTH ACROSS THE CWFA TODAY. THIS
SURFACE FEATURE IN ADDITION TO A SHORTWAVE TROUGH WILL TEND TO FOCUS
CONVECTION TODAY. IN ADDITION...ANY OUTFLOW BOUNDARY THAT THE
CONVECTION CURRENTLY TO THE NORTH LAYS OUT...MAY PROVIDE ENOUGH
SURFACE CONVERGENCE FOR CONVECTION. HI-RES MODELS...ESPECIALLY THE
WRF...HAVE PERFORMED RATHER DECENTLY OVER THE LAST FEW DAYS. BOTH
THE HRRR AND THE WRF ARE PROGGING THE BULK OF ANY ACTIVITY TODAY
ACROSS THE SOUTHERN THIRD OF THE CWFA.
THE ATMOS DOWN SOUTH HASN`T BEEN WORKED OVER AS MUCH AS FURTHER
NORTH...AND DEEP MOISTURE STILL RESIDES DOWN THERE. SURFACE
INSTABILITY WILL DEFINITELY BE PRESENT. SURFACE CONVERGENCE PROVIDED
BY THE FRONT/TROUGH...OUTFLOW BOUNDARY AND/OR SEABREEZE SHOULD
PROVIDE AMPLE LIFT TO GET THINGS STARTED. IN ADDITION...MID LEVEL
DYNAMICS WILL ALSO BE IN PLAY AS A SHORTWAVE ROUNDS THE BASE OF THE
EASTERN TROUGH. INVERTED V ON THE FORECAST SOUNDINGS SHOW THE
PRIMARY MODE OF SEVERE WEATHER SHOULD BE DAMAGING WIND GUSTS.
HOWEVER...A FEW HAIL REPORTS CANNOT BE RULED OUT AS THE SHORTWAVE
WILL SERVE TO STEEPEN LAPSE RATES.
OLD FRONT/TROUGH WILL REMAIN SITUATED ACROSS SOUTHERN GA THROUGH
TOMORROW. HOWEVER...500MB HIGH PRESSURE WILL BEGIN TO BUILD BACK
EASTWARD. THE UPPER HIGH MAY LIMIT CONVECTIVE DEVELOPMENT...BUT THE
SURFACE FEATURE MAY PROVIDE JUST ENOUGH FOCUS FOR CONVECTIVE
ACTIVITY ACROSS THE SOUTH.
HEAT INDICES ACROSS EAST CENTRAL GEORGIA WILL HAVE THE POTENTIAL TO
REACH NEAR 105 DEGREES AGAIN TODAY. HAVE GONE AHEAD AND ISSUED
ANOTHER HEAT ADVISORY FOR THE REGION.
NLISTEMAA
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THE UPPER RIDGE HAS NOSED BACK OVER THE AREA TO START THE LONG TERM.
A SURFACE TROUGH OR DISSIPATING STATIONARY FRONT ACROSS CENTRAL GA
WILL CONTINUE SMALL CHANCES FOR SHOWERS AND THUNDERSTORMS THURSDAY
NIGHT.
OTHERWISE THE UPPER RIDGE CONTINUES OVER THE AREA THROUGH SUNDAY
AND BEGINS TO WEAKEN MONDAY AND EVEN MORE SO ON TUESDAY.
THIS WILL ALLOW FOR MAINLY DIURNAL AFTERNOON AND EVENING SHOWERS
AND THUNDERSTORMS FROM THE AFTERNOON HOT TEMPERATURES AND HUMIDITY.
TEMPERATURES FOR THE MOST PART WILL BE A COUPLE TO AS MUCH AS 5-6
DEGREES ABOVE NORMAL DURING THE LONG TERM PERIOD.
BDL
&&
.AVIATION...
06Z UPDATE...
HI-RES MODELS CONTINUE TO WEAKEN THE ACTIVITY ACROSS SOUTHERN TN
THIS MORNING AND KEEP IT ACROSS FAR NORTHERN GA. PLENTY OF HIGH
CLOUD DEBRIS AROUND EARLY THIS MORNING. HI-RES WRF AND HRRR KEEP
MOST OF THE PRECIP FOR WEDNESDAY SOUTH OF THE NORTHERN TERMINAL
SITES...NEAR A SURFACE TROUGH. CIGS SHOULD REMAIN VFR. WINDS WILL
REMAIN ON THE WEST SIDE. FREQUENT GUSTS BETWEEN 15 AND 20KT LIKELY
TODAY.
//ATL CONFIDENCE...06Z UPDATE...
HIGH CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 94 72 92 72 / 40 30 10 10
ATLANTA 91 74 92 74 / 40 30 10 10
BLAIRSVILLE 85 62 85 65 / 30 30 10 10
CARTERSVILLE 91 68 91 69 / 30 30 10 10
COLUMBUS 95 76 95 75 / 40 40 30 20
GAINESVILLE 90 71 89 72 / 30 30 10 10
MACON 96 73 96 73 / 40 40 20 20
ROME 92 69 92 69 / 30 30 10 10
PEACHTREE CITY 92 71 92 71 / 40 40 20 10
VIDALIA 96 75 95 75 / 40 40 40 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM EDT THIS EVENING
FOR THE FOLLOWING ZONES: BLECKLEY...DODGE...EMANUEL...
JEFFERSON...JOHNSON...LAURENS...MONTGOMERY...PULASKI...TELFAIR...
TOOMBS...TREUTLEN...TWIGGS...WASHINGTON...WHEELER...WILCOX...
WILKINSON.
&&
$$
SHORT TERM...NLISTEMAA
LONG TERM....BDL
AVIATION...NLISTEMAA
AREA FORECAST DISCUSSION
NWS CARIBOU ME
316 AM EDT WED JUL 15 2015
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO CROSS THE THROUGH THIS AFTERNOON.
HIGH PRESSURE WILL BUILD IN FROM CANADA TONIGHT THROUGH THURSDAY
AND CREST OVER THE REGION ON FRIDAY. LOW PRESSURE FROM THE GREAT
LAKES WILL APPROACH THE REGION ON SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE COLD FRONT LIES POISED ALONG OUR NORTHWESTERN BORDER EARLY
THIS MORNING. THIS BOUNDARY WILL CONTINUE TO SLIDE SOUTHEAST
THROUGH THE DAY TODAY. A BAND OF SHOWERS CAN BE SEEN ON RADAR JUST
AHEAD OF THE BOUNDARY, AND THESE TOO WILL CROSS THE PINE TREE
STATE TODAY. A FEW LIGHTNING STRIKES HAVE BEEN REPORTED IN QUEBEC,
AND THE LATEST MODEL PROGS DO INDICATE THERE WILL BE SOME MAINLY
ELEVATED INSTABILITY OUT AHEAD OF THE FRONT. HAVE THEREFORE KEPT
ISOLATED THUNDER IN THE FORECAST THROUGH EARLY AFTERNOON. PWATS OF
UP TO 1.75 INCHES EXIST AHEAD OF THE FRONT AS WELL, SO HEAVIER
SHOWERS AND ESPECIALLY ANY THUNDERSTORMS WILL BE CAPABLE OF
PRODUCING A QUICK DOWNPOUR. MOST LOCATIONS WILL SEE LESS THAN A
HALF INCH OF RAIN, BUT WOULDN`T BE SURPRISED TO SEE SOME LOCALLY
HIGHER AMOUNTS AROUND THREE-QUARTERS OF AN INCH, ESPECIALLY IN OUR
NORTHWESTERN AREAS. THE LATEST HRRR HAS A GOOD HANDLE ON THE
CURRENT SETUP, AND IT INDICATES THE FRONT WILL BE OFFSHORE BY 4 PM
OR SO. MUCH DRIER AIR WILL OVERSPREAD THE REGION IN THE FRONT`S
WAKE; DEWPOINTS UPSTREAM ARE IN THE 40S, WITH EVEN SOME UPPER 30S.
AS SUCH, EXPECT PRECIPITATION WILL COME TO A QUICK END ONCE THE
FRONT GOES BY AND SKIES WILL RAPIDLY BECOME CLEAR.
FOR TONIGHT...HIGH PRESSURE WILL BEGIN TO BUILD EASTWARD FROM THE
GREAT LAKES. IT WILL BE A MUCH MORE COMFORTABLE NIGHT AS DEWPOINTS
DROP INTO THE 40S. AIRMASS WILL BE DRY ENOUGH TO PRECLUDE ANY FOG
DEVELOPMENT IN SPITE OF CLEAR SKIES AND LIGHT WINDS. LOWS WILL RANGE
FROM THE MID 40S NORTH TO THE LOWER 50S DOWNEAST.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
NO SIG CHGS IN THE FCST WITH REGARD TO THU AND THU NGT...WITH ALL
MODELS SHOWING CAN SFC HI PRES APCHG THE FA TUN AND CRESTING OVRHD
THU NGT. HI TEMPS THU AFTN WILL BE ABOUT 4 TO 8 DEG F BELOW AVG
WITH A LGT NW BREEZE UNDER MSLY SUNNY SKIES WITH SOME PATCHY SC
SPCLY OVR NRN PTNS OF THE FA. WINDS WILL THEN DIMINISH BY SUNSET
THU EVE...ALLOWING FOR CLR SKIES AND GOOD RADIATIONAL COOLING
OVRNGT THU AS THE SFC HI SETTLES OVRHD BY ERLY FRI MORN. WE ADDED
PATCHY LOWING LYING EVAP/CONDENSATIONAL RVR FOG LATE THU NGT AS
SFC TEMPS OVR BROAD VLY FALLS BELOW RVR WATER TEMPS FROM CNTRL
PTNS OF THE FA NWRD.
ANY PATCHY LOW LYING FOG SHOULD LIFT AND DISSIPATE WITHIN AN HR OR
TWO AFT SUNRISE FRI...WITH TEMPS RECOVERING FROM CHILLY ERLY MORN
LOWS TO NEAR SEASONAL NORMS FOR AFTN HI TEMPS WITH LGT SW WINDS.
AFTWRDS...CLDS WILL BEGIN TO INCREASE FRI NGT AS THE SFC HI CONTS
TO MOVE E TOWARD THE OPEN ATLC...AND A S/WV WITH WEAK SFC LOW PRES
FROM THE GREAT LAKES BEGINS TO APCH. THE COMBO OF INCREASING CLD
CVR AND LGT SW WINDS ASSOCIATED WITH LLVL WARM ADVCN WILL KEEP
OVRNGT LOWS FRI NGT SIG MILDER THAN THU NGT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
LONGER RANGE MODELS DIFFER ON THE ONSET SPEED OF RNFL ON SAT FROM
THE GREAT LKS S/WV AS IT APCHS AND CROSSES OUR FA SAT/SAT NGT. THE
00Z DTMNSTC GFS AND NAM ARE IN THE FASTER MODEL CAMP WHILE THE 00Z
ECMWF IS SLOWER. THE 00Z CANGEM AND GFS ESMN AS WELL AS THE 21Z
SREF ARE IN THE MIDDLE...SO WENT WITH THE SUPERBLEND POPS WHICH
REFLECTED COMPROMISED ONSET TMG RESULTING IN SHWRS MOVG INTO THE
FA DURG THE DAY SAT. FOR NOW...GIVEN MODEL TMG AND OVRRNG POTENTIAL
DIFFERENCES...WE KEPT MAX POPS IN THE HI CHC CAT FOR NOW.
OTHERWISE...WITH ADDITIONAL S/WVS AND CONTD SRLY LLVL FLOW ACROSS
THE FA...WE KEPT CHC SHWR POPS GOING THRU SUN AND MON...ALTHOUGH
SIG PTNS OF EACH DAY WILL LIKELY BE RN FREE OVR ANY PARTICULAR
LCTN ACROSS THE FA. A STRONGER S/WV WILL BRING A BETTER CHC OF
SHWRS TUE INTO ERLY WED MORN...WHERE WE GO WITH LOW LIKELY MAX
POPS BY TUE AFTN INTO TUE NGT. ALTHOUGH WE CANNOT RULE OUT TSTMS
DURG THE AFTN/EVE HRS FROM SUN TO TUE...THE FACT THAT HI TEMPS
WILL LIKELY BE HELD DOWN TO AOB SEASONAL NORMS COULD KEEP SFC/ML
CAPES TO LOW...SO FOR NOW WE HELD OFF ANY MENTION OF THUNDER FOR
THESE DAYS ATTM. OVRNGT LOWS WILL BE A LITTLE ABV AVG MSLY DUE TO
POTENTIAL CLD CVR AND SRLY BREEZES.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: WIDESPREAD IFR CONDITIONS IN SHOWERS AND FOG TO
CONTINUE EARLY THIS MORNING, ESPECIALLY AT KBGR AND KBHB. A COLD
FRONT WILL CONTINUE TO SLIDE SOUTHEAST ACROSS THE REGION, WITH
SHOWERS ALONG AND AHEAD OF IT. CONDITIONS WILL QUICKLY IMPROVE
ONCE THE FRONT GOES BY AS DRIER AIR WORKS INTO THE STATE. EXPECT
VFR AT KFVE BY 18Z...AND AT KBHB BY 00Z. HIGH PRESSURE AND VFR
CONDITIONS TO PREVAIL THEREAFTER.
SHORT TERM: VFR XPCTD ALL TAF SITES THU THRU FRI NGT. MVFR CLGS
AND VSBYS POSSIBLE WITH CLGS AND SHWRS/RN SAT...SPCLY SAT AFTN.
MVFR OR IFR CLGS/VSBYS POSSIBLE SAT NGT WITH SHWRS PERHAPS SLOWLY
RECOVERING TO HI MVFR/VFR BY SUN AFTN.
&&
.MARINE...
NEAR TERM: A COLD FRONT WILL APPROACH THE WATERS FROM THE
NORTHWEST THIS MORNING AND MOVE OFFSHORE THIS AFTERNOON. SOUTH-
SOUTHWEST WINDS 5 TO 10 KT WILL BECOME NORTH-NORTHWEST BY THIS
EVENING. SOME INCREASE IN THE WINDS IS EXPECTED OVERNIGHT AS THE
PRESSURE GRADIENT TIGHTENS; IN GENERAL AROUND 10 KT WITH GUSTS TO
20 KT. SEAS WILL BUILD IN RESPONSE, BUT BOTH WAVES AND WINDS WILL
REMAIN BELOW SMALL CRAFT LEVELS. THEREFORE NO HEADLINES ARE
ANTICIPATED.
SHORT TO LONG TERM: THE FCST OPENS IN THE NEAR TERM WITH NEAR SCA
WV HTS MSLY OVR OUR OUTER MZS THU MORN DUE TO LEFT OVR LONG PD
SWELL FROM THE OPEN ATLC...WITH WV HTS GRADUALLY SUBSIDING LATER
THU AFTN AND NGT. WINDS ARE XPCTD TO REMAIN BLO SCA THRU THE SHORT
INTO LONG TERM. WE WENT WITH 90 PERCENT OF CONSRAW DATA FOR
SUSTAINED WIND SPEEDS OVR THE WATERS AND ABOUT 65 PERCENT OF WW3
WV GUIDANCE OVR THE NEAR SHORE UP TO 90 PERCENT OF WW3 WV GUIDANCE
OVR THE OUTER MZ WATERS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HASTINGS
SHORT TERM...VJN
LONG TERM...VJN
AVIATION...HASTINGS/VJN
MARINE...HASTINGS/VJN
AREA FORECAST DISCUSSION
NWS GRAY ME
122 AM EDT WED JUL 15 2015
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE WEST TONIGHT AND CROSS MAINE
AND NEW HAMPSHIRE DURING THE DAY ON WEDNESDAY...BRINGING SHOWERS
AND THUNDERSTORMS. HIGH PRESSURE THEN MOVES IN FOR WEDNESDAY NIGHT
THROUGH FRIDAY. THE HIGH WILL SHIFT OFFSHORE OVER THE WEEKEND
ALLOWING FOR A WARMER AND MORE MOIST AIRMASS TO MOVE IN...POSSIBLY
ASSOCIATED WITH SHOWERS AND THUNDERSTORMS. THIS ACTIVITY COULD
PERSIST INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
UPDATE...
HAVE UPDATED THE GRIDS BASED ON CURRENT CONDTIONS. THERE IS VERY
LITTLE IN THE WAY OF SCATTERED SHOWERS ACROSS THE FORECAST AREA AS
OF 05Z. SOME PRECIP TO OUR WEST WILL MOVE INTO THE
REGION...HOWEVER LATEST HRRR HAS THIS SHOWER ACTIVITY DISSIPATING
AS IT MOVES TO THE EAST AND INTO NEW HAMPSHIRE.
MINOR ADJUSTMENTS MADE TO DEW POINTS AND TEMPERATURES LATE THIS
EVENING.
PREV DISC...
910 PM UPDATE: OCEAN LOW CLOUDS AND STRATUS HAVE
MOVED WEST ALONG THE ME COAST AND SOME INLAND AREAS OF ME BUT HAVE
NOT REACHED FAR ENOUGH WEST INTO NH. SOME AREAS OF FOG HAD
DEVELOPED BUT IS NOT WIDESPREAD. MADE ADJUSTMENTS ON THE 6 PM
UPDATE TO PUSH BACK FOG DEVELOPMENT AND LOOKS GOOD AT THIS TIME.
FOG MAY BECOME DENSE IN A FEW AREAS BUT GENERALLY NOT EXPECTING
WIDESPREAD DENSE FOG.
ALSO ON EARLIER UPDATE ADJUSTED FORECAST TO REFLECT ONLY SOME
LIGHT SHOWERS FOR THE REST OF THE EVENING AND ELIMINATED ANY
MENTION OF THUNDER. WILL KEEP THIS THINKING IN TACT AND ANY
MENTION OF THUNDER WILL NOT BE UNTIL WELL AFTER MIDNIGHT...RADAR/SATELLITE
CONFIRMS THIS THINKING. MINOR ADJUSTMENTS TO TEMPERATURES BASED ON
LATEST OBSERVATIONS.
PREVIOUS DISCUSSION:
A COLD FRONT WILL GRADUALLY DROP SOUTHEASTWARD INTO MAINE AND NEW
HAMPSHIRE TONIGHT...AND LIKELY BE POSITIONED JUST WEST OF THE
COASTAL PLAIN COME 12Z WEDNESDAY. SCT SHOWERS WILL MOVE FROM S TO
N ACROSS THE REGION THROUGH EARLY THIS EVENING BEFORE STRONGER
FORCING FOR ASCENT ARRIVES LATER IN THE EVENING. THIS SHOULD
RESULT IN AN INCREASE IN SHOWERS ACROSS WESTERN AND NORTHERN ZONES
LATE THIS EVENING AND OVERNIGHT WHILE THE COASTAL PLAIN REMAINS
MAINLY DRY. MAY HAVE TO BE ON THE LOOKOUT FOR LOCALIZED
FLOODING...ESPECIALLY IN COOS COUNTY WHERE THEY RECEIVED HEAVY
RAIN YESTERDAY.
AREAS OF DENSE FOG MAY BECOME AN ISSUE FROM YORK COUNTY NORTHWARD
THROUGH CUMBERLAND COUNTY AND ON NORTHEASTWARD UP I-95 ON EAST.
WILL HOLD OFF ON DENSE FOG ADVISORY AT THIS TIME DUE TO
UNCERTAINTY ON HOW WIDESPREAD 1/4 MILE OR LESS VSBYS WILL BE...BUT
ONE COULD BE NECESSARY LATER ON.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
COLD FRONT TO MOVE OFFSHORE PRIOR TO 18Z WEDNESDAY. SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO ACCOMPANY THIS FRONT...ESPECIALLY
ON THE COASTAL PLAIN WHERE SOME EARLY HEATING AND LINEAR FORCING
MAY ALLOW FOR MORE ROBUST AND WIDESPREAD UPDRAFTS. NOT THINKING
SEVERE AT THIS TIME...BUT SOME GUSTY WINDS...FREQUENT
LIGHTNING...AND HEAVY DOWNPOURS WILL BE POSSIBLE PRIOR TO FRONTAL
PASSAGE.
RAPID CLEARING TO TAKE PLACE PRIOR TO SUNSET...WITH COOLER AND
DRIER AIR MOVING IN FOR WEDNESDAY EVENING/NIGHT. LOWS IN THE THE
LOWER TO MID 40S LIKELY IN THE MOUNTAINS AS REFRESHING AIRMASS
MOVES ON IN.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
HIGH PRES BUILDS IN EARLY THU...AND REMAINS IN CONTROL OF THE
REGION THRU FRI. NLY BREEZE WILL FOLLOW THE DEPARTING COLD
FRONT...AS COOLER AND DRIER AIR WORKS IN. RIDGE AXIS SETTLES
OVERHEAD THU NIGHT INTO EARLY FRI. EXPECT A GOOD RADIATIONAL
COOLING NIGHT...AND WENT A FEW DEGREES BELOW GUIDANCE TO ACCOUNT
FOR THIS. ALSO EXPECT AREAS OF VALLEY FOG TO DEVELOP IN THE
FAVORED LOW LYING AREAS AND COOL SPOTS.
WX BECOMES MORE UNSETTLED INTO THE WEEKEND...AS HIGH PRES SLIDES
EWD AND RIDGING ALOFT DEPARTS. A POSSIBLY CONVECTIVELY ENHANCED
S/WV TROF WILL PASS THRU THE GREAT LAKES AND APPROACH WRN ZONES
SAT. CONFIDENCE IS PRETTY LOW ON TIMING AND COVERAGE OF ANY
PRECIP...SO WILL KEEP THINGS CHANCE POP FOR NOW. WEAK S/WV RIDGING
IS EVIDENT IN MODEL GUIDANCE FOR SUN...SO MAYBE POP IS A BIT
OVERDONE IN THIS PERIOD...BUT STRONGER S/WV TROF ARRIVES EARLY
NEXT WEEK AND INCREASES THE CHANCES FOR MORE SHOWERS/TSTMS.
TEMPS LOOK TO AVERAGE NEAR NORMAL FOR HIGHS...AND SLIGHTLY ABOVE
NORMAL FOR LOWS...AS IT WILL TEND TOWARDS RETURN FLOW AND MORE
MOIST AIR MASSES.
&&
.AVIATION /05Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM...MAINLY VFR CONDITIONS ARE EXPECTED THROUGH ABOUT
22-23Z EARLY THIS EVENING BEFORE FOG AND STRATUS IS EXPECTED TO
MOVE IN ON THE COASTAL PLAIN...MAINLY NORTH OF PSM. CIGS/VSBYS
SHOULD DROP TO LIFR FOR KPWM UP THROUGH KRKD AND REMAIN THAT WAY
OVERNIGHT. AUG WILL LIKELY SEE THIS AS WELL. SOME UNCERTAINTY
EXISTS ON SOUTHWARD EXTENT...BUT WE THINK PSM SHOULD STILL SEE
SOME IFR CONDITIONS. FURTHER INLAND...LOW CONDITIONS WILL NOT BE
AS WIDESPREAD...BUT SHOWERS AND POSSIBLE THUNDER ARE LIKELY IN THE
INTERIOR OVERNIGHT. ON WEDNESDAY...LOW CONDITIONS IN THE EARLY
MORNING SHOULD GIVE WAY TO IMPROVEMENT BY 14Z...BUT BE REPLACED BY
SHOWERS AND THUNDERSTORMS BETWEEN 14Z AND 18Z. THEREAFTER...VFR
CONDITIONS ARE EXPECTED THROUGH WED NIGHT.
LONG TERM...VFR GENERALLY EXPECTED TO BEGIN THE PERIOD FOR ALL
TERMINALS. HIGH PRES SETTLING OVERHEAD EARLY FRI MAY LEAD TO AREAS
OF VALLEY FOG...ESPECIALLY AT FAVORED LOCATIONS LIKE HIE AND LEB.
BY THE WEEKEND...WEAK UPPER TROF MOVING THRU THE AREA MAY LEAD TO
SCATTERED SHRA/TSRA...WITH AREAS OF MVFR AND LOCAL IFR CONDITIONS
POSSIBLE.
&&
.MARINE...
SHORT TERM...WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SCA
CRITERIA THROUGH WEDNESDAY NIGHT...ALTHOUGH SEAS MAY APPROACH OR
BRIEFLY EXCEED 5 FT ON THE OUTER WATERS WED AFTERNOON AND
EVENING...MAINLY DUE TO SWELL.
LONG TERM...WINDS AND SEAS GENERALLY EXPECTED TO REMAIN BELOW SCA
THRESHOLDS. SOME SEAS NEAR 5 FT POSSIBLE EARLY THU...MAINLY DUE TO
SWELL.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1152 PM CDT TUE JUL 14 2015
.SHORT TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 239 PM CDT TUE JUL 14 2015
TWO ROUNDS OF THUNDERSTORMS ARE ANTICIPATED IN THE SHORT TERM WITH
THE FIRST ROUND ADVANCING NORTHEAST INTO THE CWA FROM NORTH
CENTRAL KANSAS/SOUTH CENTRAL NEBRASKA OVERNIGHT INTO THE EARLY
MORNING HOURS WEDNESDAY AND THE SECOND ROUND DEVELOPING WEDNESDAY
AFTERNOON.
LATEST WATER VAPOR IMAGERY AND RAP 500 MB ANALYSIS SHOW AN UPPER
LEVEL RIDGE AXIS EXTENDING FROM THE SOUTH CENTRAL CONUS THROUGH
SOUTH CENTRAL CANADA. MONSOONAL FLOW CONTINUES TO MOVE THROUGH THE
INTERMOUNTAIN WEST WITH TWO DISTINCT SHORTWAVE TROUGHS THAT WILL
SOON IMPACT THE REGION. THE FIRST SHORTWAVE IS CURRENTLY LOCATED
OVER SOUTHEAST COLORADO WITH THE SECOND CURRENTLY OVER
SOUTHWESTERN NEW MEXICO.
AHEAD OF THIS...A FEW ISOLATED THUNDERSTORMS HAVE DEVELOPED NEAR
THE RIDGE AXIS IN CENTRAL NEBRASKA THIS AFTERNOON. A FEW OF THE
CAM`S BRING THIS ACTIVITY INTO OUR FAR WESTERN COUNTIES LATER THIS
EVENING BUT GENERAL FEELING IS THAT THEY WILL WEAKEN AS THEY
CONTINUE EAST AND HAVE LITTLE IMPACT ON THE CWA.
TSTMS ARE EXPECTED TO DEVELOP LATER ACROSS NORTH CENTRAL KANSAS
OVERNIGHT IN ADVANCE OF ABOVE MENTIONED SHORTWAVE IN STRONG WAA
REGIME AIDED BY NOSE OF NOCTURNAL LOW LEVEL JET. THIS ACTIVITY
WILL SPREAD NORTHEAST THROUGH THE MORNING AND LIKELY EXIT THE AREA
BY NOON. SOME OF THESE STORMS COULD BE SEVERE...BUT WILL BE
ELEVATED.
A DEVELOPING SURFACE LOW OVER WESTERN KANSAS AND ASSOCIATED
NORTHEASTWARD EXTENDING WARM FRONT WILL PUSH INTO SOUTHERN
NEBRASKA BY PEAK HEATING WEDNESDAY. IN ADDITION...THE SECOND ABOVE
MENTIONED PIECE OF SHORTWAVE ENERGY WILL MOVE TOWARD CENTRAL
NEBRASKA. DEPENDING ON SPEED OF EXITING MORNING TSTMS...THE
ATMOSPHERE SHOULD BE ABLE TO RECOVER LEADING TO MODERATE TO STRONG
INSTABILITY OVER THE FORECAST AREA BY PEAK HEATING. STRONG BULK
LAYER SHEAR VALUES WOULD INDICATE POTENTIAL FOR SUPERCELLS
INITIALLY...WITH A TORNADIC THREAT ALONG AND AHEAD OF THE WARM
FRONT. IN ADDITION TO SEVERE WEATHER...HEAVY RAIN IS ALSO POSSIBLE
WITH THE MORNING CONVECTION AND THE AFTERNOON/EVENING CONVECTION
WITH PW`S AOA 2.00". MUCH OF THE CWA IS OUTLOOKED IN THE SLIGHT
CATEGORY FOR EXCESSIVE RAINFALL AND FEEL THIS IS QUITE REASONABLE
GIVEN AMOUNT OF AVAILABLE MOISTURE. SOUTHWESTERLY NOCTURNAL LOW
LEVEL JET SHOULD SUSTAIN TSTM ACTIVITY AS IT PROGRESSES NORTHEAST
THROUGH THE CWA...ENDING IT THURSDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 239 PM CDT TUE JUL 14 2015
MODEST WESTERLY/SOUTHWESTERLY FLOW ALOFT WILL PERSIST INTO THE
WEEKEND. VERY HARD TO PIN DOWN EXACT TIMING OF THESE WAVES IN THE
LONG TERM...BUT CANNOT REALLY RULE OUT TSTMS IN ANY PARTICULAR PERIOD
WITH THIS TYPE OF PATTERN. WILL CARRY A LOW CONFIDENCE SMALL POP
THROUGH MUCH OF THE PERIOD. TEMPERATURES OVERALL LOOK SEASONAL.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1143 PM CDT TUE JUL 14 2015
DETERIORATING CONDITIONS A DISTINCT POSSIBILITY WITHIN THE NEXT
COUPLE HOURS AT THE TAF SITES. LATEST MODEL GUIDANCE IS SUGGESTING
A LINE OF CONVECTION INITIATING OVER S-CNTRL SD INTO ERN NEB BTWN
15/08Z-12Z THIS MORNING WITH ACTIVITY POSSIBLY CONTINUING THRU MID
MORNING. HOWEVER HAVE DECIDED TO LIMIT TEMPO GROUPS TO A COUPLE
HOURS DUE TO LOW CONFIDENCE OF AREAL COVERAGE. ANOTHER ROUND OS
TSRA POSSIBLE LATER THIS AFTN ALONG A WARM FRONT LIFTING OUT OF KS
AND INTO NEB. SVR TSTMS APPEAR PROBABLE FROM LATE AFTERNOON UNTIL
EARLY EVENING.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...KERN
LONG TERM...KERN
AVIATION...DEE
AREA FORECAST DISCUSSION
NWS RALEIGH NC
326 AM EDT WED JUL 15 2015
.SYNOPSIS...UPPER TROUGH OVER THE AREA THIS MORNING WILL MOVE OFF
THE MID-ATLANTIC COAST THIS AFTERNOON. THE ATTENDANT SURFACE COLD
FRONT WILL FOLLOW SUITE...WITH HIGH PRESSURE BUILDING INTO THE AREA
TONIGHT THROUGH THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 PM TUESDAY...
..SLIGHT RISK OF SEVERE THUNDERSTORMS REMOVED...
IT APPEARS THAT RAPIDLY DEVELOPING CONVECTIVE INHIBITION WITH
NIGHTFALL WILL LIKELY NOT BE SUPPORTIVE OF REDEVELOPMENT OF THE
CONVECTIVE LINE AS THE REMNANTS MOVE OFF THE BLUE RIDGE OF VA/NC
INTO OUR NW PIEDMONT. THE MORE FAVORABLE CONVECTIVE PARAMETERS FOR
CONVECTION CONTINUE OVER CENTRAL AND NORTHERN VA AND THIS IS WHERE
THE LINE WAS RE-FIRING AND HEADED TOWARD RICHMOND.
WE WILL KEEP LOW CHANCE POP FOR SOME RESIDUAL SHOWERS AND ISOLATED
THUNDER CHANCE FOR A FEW MORE HOURS IN THE NW-NE PIEDMONT AND FAR NE
ZONES OF THE COASTAL PLAIN... OTHERWISE PARTLY CLOUDY OVERNIGHT.
LOWS 68-73.
PREVIOUS DISCUSSION AT 730 PM...
ANOTHER... THE LAST IN THE SERIES OF CONVECTIVE COMPLEXES WAS DIVING
SOUTHEAST INTO WESTERN AND SOUTHWESTERN VIRGINIA AIMED AT NORTHERN
NORTH CAROLINA AT 725 PM. THE HIGHEST INSTABILITY RESIDED OUT AHEAD
OF THE LINE OVER VIRGINIA. THE INSTABILITY AXIS WEAKENED BUT
EXTENDED INTO THE NORTHERN AND EASTERN SECTIONS OF NC. SURFACE DEW
POINTS WERE IN THE 70S NORTH AND EAST... AND 60S IN THE SW PIEDMONT.
DEEP LAYER SHEAR WAS BEST TO OUR NORTH AS WELL... BUT 35-45KT OF
SHEAR EXTENDED OVER THE REGION NEAR THE NC/VA BORDER.
INTERESTINGLY... EVEN AS THE LINE WAS ONLY 2-3 HOURS FROM
POTENTIALLY AFFECTING A PORTION OF OUR REGION... MANY OF THE NEAR
TERM MODELS INCLUDING THE ARW AND HRRR WERE FORECASTING THE CORE OF
THE MCS TO DIVE SOUTH THEN SOUTHWEST TOWARD BOONE/BRISTOL/TRI CITIES
AREA BY LATE EVENING. THE STORM PREDICTION CENTER FELT THAT THE LINE
WOULD CONTINUE MOVING SE AND EITHER MAINTAIN ITSELF OR WEAKEN...
THEN RE-INTENSIFY AS IT HITS A FAVORABLE ENVIRONMENT MENTIONED ABOVE
IN THE VA/FAR NORTHERN NC PIEDMONT. THIS IS WHERE A SEVERE
THUNDERSTORM WATCH WAS PLACED AS FAR SOUTH AS MOUNT AIRY AND
YANCEYVILLE THROUGH 100 AM.
JUST AS IN THE PREVIOUS NW FLOW CONVECTIVE COMPLEXES AND LINES THAT
HAVE AFFECTED OUR REGION - IT WILL LIKELY HAVE TO BE NOWCAST RATHER
THAN FORECAST AS TO THE HOW IT WILL AFFECT OUR REGION. AT THE
CURRENT TIME IT APPEARS LIKELY THAT AT LEAST THE NORTH-NORTHEAST
PIEDMONT FROM THE TRIAD TO ROXBORO TO THE NORTHERN PART OF THE
TRIANGLE WILL HAVE TO DEAL WITH AT LEAST SOME GUSTY WINDS AND
LOCALLY HEAVY RAIN BETWEEN 900 PM AND MIDNIGHT.
WE WILL MAINTAIN THE CURRENT FORECAST WORDING AND THE CURRENT
HAZARDOUS WEATHER OUTLOOK UNTIL THE THREAT FROM THIS SYSTEM
DIMINISHES OR PASSES. IT APPEARS THE THREAT OF SEVERE STORMS IS
LOWEST IN THE SOUTH AND WEST (WHERE THE CONVECTIVE PARAMETERS ARE
MUCH LOWER) - DUE TO SOME NEGATIVE RESIDUAL AFFECTS OF THE SYSTEM
THAT PASSED BY THIS MORNING AND THE CURRENT ONE THAT BRUSHED BY TO
THE WEST OF ASHEVILLE.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 315 PM TUESDAY...
A MID LEVEL TROUGH IS PROGGED TO BE SHIFTING OFF THE MID ATLANTIC
COAST THROUGHOUT THE DAY ON WEDNESDAY. AS THIS DOES SO...A COLD
FRONT WILL GRADUALLY TRACK ACROSS THE REGION...EVENTUALLY SETTLING
SOUTH OF THE AREA BY WEDNESDAY NIGHT. ALL OF THIS WILL LEAD TO A
DECREASE IN CONVECTIVE COVERAGE AS THE BEST FORCING AND MOISTURE
WILL GRADUALLY BE SHIFTING OFF TO THE NORTH AND EAST OF THE AREA.
THEREFORE...WILL SHOW A GRADUAL PROGRESSION OF DECREASING PRECIP
CHANCES FROM WEST TO EAST THROUGHOUT THE DAY...HOWEVER POPS WILL BE
NO HIGHER THAN SLIGHT CHANCE. TEMPS WILL BE SLIGHTLY ABOVE NORMAL
(RANGING FROM NEAR 90 DEGREES TO THE LOWER 90S)...ALTHOUGH HUMIDITY
VALUES WILL BE LOWER THAN PREVIOUS DAYS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 325 AM WEDNESDAY...
A FRONT INITIALLY OVER THE SAVANNAH BASIN WILL RETREAT NORTHEAST
ACROSS NC FRI-SAT...IN ADVANCE OF AN AREA OF LOW PRESSURE FORECAST
TO MIGRATE THROUGH THE GREAT LAKES. PRECEDING HIGH PRESSURE
INITIALLY CENTERED ALONG THE NORTHERN MIDDLE ATLANTIC COAST...AND
ASSOCIATED ENE FLOW ACROSS CENTRAL-EASTERN NC...WILL MAINTAIN
STABILITY OVER MOST OF THE REGION ON FRI. THE EXCEPTION WILL BE NEAR
THE YADKIN RIVER...WHERE THE RETREAT OF THE BOUNDARY AND ASSOCIATED
LOW LEVEL CONFLUENT FLOW AND INCREASING BOUNDARY LAYER MOISTURE MAY
SUPPORT A FEW SHOWERS OR STORMS FRI AFTERNOON.
OTHERWISE...BOTH TEMPERATURES AND HUMIDITY LEVELS WILL INCREASE
THROUGH THE WEEKEND AS THE LOW LEVEL FLOW ASSUMES A MORE SW
DIRECTION...AND SUB-TROPICAL RIDGING ALOFT CENTERED OVER THE LOWER
MS VALLEY AND SOUTHERN PLAINS BUILDS EAST INTO THE SOUTHERN-CENTRAL
APPALACHIANS. NEAR CLIMO PROBABILITY OF PRECIPITATION --WITH A FOCUS
ALONG THE MOUNTAINS; PIEDMONT TROUGH; AND SEA BREEZE-- IS GENERALLY
EXPECTED...WITH PERHAPS A RELATIVE PEAK THIS WEEKEND WHEN THE
ORIENTATION AND LOCATION OF THE SUB-TROPICAL RIDGE WOULD ALLOW FOR
WEAK DISTURBANCES IN NW TO NNW FLOW ALOFT TO DRIFT ACROSS NC.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 200 AM WEDNESDAY...
UPPER LEVEL TROUGH MOVING THROUGH THE AREA THIS MORNING MAY SUPPORT
AN ISOLATED SHOWER OR TWO. OTHERWISE...VFR CONDITIONS ARE EXPECTED
TO PREVAIL THROUGH THE TAF PERIOD. THE EXCEPTION WILL BE ACROSS THE
COASTAL SECTIONS...WHERE ISOLD CONVECTION WILL BE POSSIBLE INVOF THE
EXITING COLD FRONT...THOUGH ACTIVITY SHOULD REMAIN EAST/SOUTH OF THE
FAY TERMINAL.
LOOKING AHEAD: THURSDAY THROUGH SUNDAY WILL BE LESS ACTIVE THAN
PREVIOUS DAYS...WITH MORE IN THE WAY OF TYPICAL DIURNAL CONVECTION
THROUGH THE PERIOD. ASIDE FROM SOME PREDAWN MORNING
FOG/STRATUS...EXPECT PREDOMINATELY VFR CONDITIONS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...PWB
SHORT TERM...KRD
LONG TERM...26
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
326 AM EDT TUE JUL 15 2015
.SYNOPSIS...UPPER TROUGH OVER THE AREA THIS MORNING WILL MOVE OFF
THE MID-ATLANTIC COAST THIS AFTERNOON. THE ATTENDANT SURFACE COLD
FRONT WILL FOLLOW SUITE...WITH HIGH PRESSURE BUILDING INTO THE AREA
TONIGHT THROUGH THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 PM TUESDAY...
..SLIGHT RISK OF SEVERE THUNDERSTORMS REMOVED...
IT APPEARS THAT RAPIDLY DEVELOPING CONVECTIVE INHIBITION WITH
NIGHTFALL WILL LIKELY NOT BE SUPPORTIVE OF REDEVELOPMENT OF THE
CONVECTIVE LINE AS THE REMNANTS MOVE OFF THE BLUE RIDGE OF VA/NC
INTO OUR NW PIEDMONT. THE MORE FAVORABLE CONVECTIVE PARAMETERS FOR
CONVECTION CONTINUE OVER CENTRAL AND NORTHERN VA AND THIS IS WHERE
THE LINE WAS RE-FIRING AND HEADED TOWARD RICHMOND.
WE WILL KEEP LOW CHANCE POP FOR SOME RESIDUAL SHOWERS AND ISOLATED
THUNDER CHANCE FOR A FEW MORE HOURS IN THE NW-NE PIEDMONT AND FAR NE
ZONES OF THE COASTAL PLAIN... OTHERWISE PARTLY CLOUDY OVERNIGHT.
LOWS 68-73.
PREVIOUS DISCUSSION AT 730 PM...
ANOTHER... THE LAST IN THE SERIES OF CONVECTIVE COMPLEXES WAS DIVING
SOUTHEAST INTO WESTERN AND SOUTHWESTERN VIRGINIA AIMED AT NORTHERN
NORTH CAROLINA AT 725 PM. THE HIGHEST INSTABILITY RESIDED OUT AHEAD
OF THE LINE OVER VIRGINIA. THE INSTABILITY AXIS WEAKENED BUT
EXTENDED INTO THE NORTHERN AND EASTERN SECTIONS OF NC. SURFACE DEW
POINTS WERE IN THE 70S NORTH AND EAST... AND 60S IN THE SW PIEDMONT.
DEEP LAYER SHEAR WAS BEST TO OUR NORTH AS WELL... BUT 35-45KT OF
SHEAR EXTENDED OVER THE REGION NEAR THE NC/VA BORDER.
INTERESTINGLY... EVEN AS THE LINE WAS ONLY 2-3 HOURS FROM
POTENTIALLY AFFECTING A PORTION OF OUR REGION... MANY OF THE NEAR
TERM MODELS INCLUDING THE ARW AND HRRR WERE FORECASTING THE CORE OF
THE MCS TO DIVE SOUTH THEN SOUTHWEST TOWARD BOONE/BRISTOL/TRI CITIES
AREA BY LATE EVENING. THE STORM PREDICTION CENTER FELT THAT THE LINE
WOULD CONTINUE MOVING SE AND EITHER MAINTAIN ITSELF OR WEAKEN...
THEN RE-INTENSIFY AS IT HITS A FAVORABLE ENVIRONMENT MENTIONED ABOVE
IN THE VA/FAR NORTHERN NC PIEDMONT. THIS IS WHERE A SEVERE
THUNDERSTORM WATCH WAS PLACED AS FAR SOUTH AS MOUNT AIRY AND
YANCEYVILLE THROUGH 100 AM.
JUST AS IN THE PREVIOUS NW FLOW CONVECTIVE COMPLEXES AND LINES THAT
HAVE AFFECTED OUR REGION - IT WILL LIKELY HAVE TO BE NOWCAST RATHER
THAN FORECAST AS TO THE HOW IT WILL AFFECT OUR REGION. AT THE
CURRENT TIME IT APPEARS LIKELY THAT AT LEAST THE NORTH-NORTHEAST
PIEDMONT FROM THE TRIAD TO ROXBORO TO THE NORTHERN PART OF THE
TRIANGLE WILL HAVE TO DEAL WITH AT LEAST SOME GUSTY WINDS AND
LOCALLY HEAVY RAIN BETWEEN 900 PM AND MIDNIGHT.
WE WILL MAINTAIN THE CURRENT FORECAST WORDING AND THE CURRENT
HAZARDOUS WEATHER OUTLOOK UNTIL THE THREAT FROM THIS SYSTEM
DIMINISHES OR PASSES. IT APPEARS THE THREAT OF SEVERE STORMS IS
LOWEST IN THE SOUTH AND WEST (WHERE THE CONVECTIVE PARAMETERS ARE
MUCH LOWER) - DUE TO SOME NEGATIVE RESIDUAL AFFECTS OF THE SYSTEM
THAT PASSED BY THIS MORNING AND THE CURRENT ONE THAT BRUSHED BY TO
THE WEST OF ASHEVILLE.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 315 PM TUESDAY...
A MID LEVEL TROUGH IS PROGGED TO BE SHIFTING OFF THE MID ATLANTIC
COAST THROUGHOUT THE DAY ON WEDNESDAY. AS THIS DOES SO...A COLD
FRONT WILL GRADUALLY TRACK ACROSS THE REGION...EVENTUALLY SETTLING
SOUTH OF THE AREA BY WEDNESDAY NIGHT. ALL OF THIS WILL LEAD TO A
DECREASE IN CONVECTIVE COVERAGE AS THE BEST FORCING AND MOISTURE
WILL GRADUALLY BE SHIFTING OFF TO THE NORTH AND EAST OF THE AREA.
THEREFORE...WILL SHOW A GRADUAL PROGRESSION OF DECREASING PRECIP
CHANCES FROM WEST TO EAST THROUGHOUT THE DAY...HOWEVER POPS WILL BE
NO HIGHER THAN SLIGHT CHANCE. TEMPS WILL BE SLIGHTLY ABOVE NORMAL
(RANGING FROM NEAR 90 DEGREES TO THE LOWER 90S)...ALTHOUGH HUMIDITY
VALUES WILL BE LOWER THAN PREVIOUS DAYS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 325 AM WEDNESDAY...
A FRONT INITIALLY OVER THE SAVANNAH BASIN WILL RETREAT NORTHEAST
ACROSS NC FRI-SAT...IN ADVANCE OF AN AREA OF LOW PRESSURE FORECAST
TO MIGRATE THROUGH THE GREAT LAKES. PRECEDING HIGH PRESSURE
INITIALLY CENTERED ALONG THE NORTHERN MIDDLE ATLANTIC COAST...AND
ASSOCIATED ENE FLOW ACROSS CENTRAL-EASTERN NC...WILL MAINTAIN
STABILITY OVER MOST OF THE REGION ON FRI. THE EXCEPTION WILL BE NEAR
THE YADKIN RIVER...WHERE THE RETREAT OF THE BOUNDARY AND ASSOCIATED
LOW LEVEL CONFLUENT FLOW AND INCREASING BOUNDARY LAYER MOISTURE MAY
SUPPORT A FEW SHOWERS OR STORMS FRI AFTERNOON.
OTHERWISE...BOTH TEMPERATURES AND HUMIDITY LEVELS WILL INCREASE
THROUGH THE WEEKEND AS THE LOW LEVEL FLOW ASSUMES A MORE SW
DIRECTION...AND SUB-TROPICAL RIDGING ALOFT CENTERED OVER THE LOWER
MS VALLEY AND SOUTHERN PLAINS BUILDS EAST INTO THE SOUTHERN-CENTRAL
APPALACHIANS. NEAR CLIMO PROBABILITY OF PRECIPITATION --WITH A FOCUS
ALONG THE MOUNTAINS; PIEDMONT TROUGH; AND SEA BREEZE-- IS GENERALLY
EXPECTED...WITH PERHAPS A RELATIVE PEAK THIS WEEKEND WHEN THE
ORIENTATION AND LOCATION OF THE SUB-TROPICAL RIDGE WOULD ALLOW FOR
WEAK DISTURBANCES IN NW TO NNW FLOW ALOFT TO DRIFT ACROSS NC.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 200 AM WEDNESDAY...
UPPER LEVEL TROUGH MOVING THROUGH THE AREA THIS MORNING MAY SUPPORT
AN ISOLATED SHOWER OR TWO. OTHERWISE...VFR CONDITIONS ARE EXPECTED
TO PREVAIL THROUGH THE TAF PERIOD. THE EXCEPTION WILL BE ACROSS THE
COASTAL SECTIONS...WHERE ISOLD CONVECTION WILL BE POSSIBLE INVOF THE
EXITING COLD FRONT...THOUGH ACTIVITY SHOULD REMAIN EAST/SOUTH OF THE
FAY TERMINAL.
LOOKING AHEAD: THURSDAY THROUGH SUNDAY WILL BE LESS ACTIVE THAN
PREVIOUS DAYS...WITH MORE IN THE WAY OF TYPICAL DIURNAL CONVECTION
THROUGH THE PERIOD. ASIDE FROM SOME PREDAWN MORNING
FOG/STRATUS...EXPECT PREDOMINATELY VFR CONDITIONS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...PWB
SHORT TERM...KRD
LONG TERM...26
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
200 AM EDT TUE JUL 15 2015
.SYNOPSIS...UPPER TROUGH OVER THE AREA THIS MORNING WILL MOVE OFF
THE MID-ATLANTIC COAST THIS AFTERNOON. THE ATTENDANT SURFACE COLD
FRONT WILL FOLLOW SUITE...WITH HIGH PRESSURE BUILDING INTO THE AREA
TONIGHT THROUGH THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 PM TUESDAY...
..SLIGHT RISK OF SEVERE THUNDERSTORMS REMOVED...
IT APPEARS THAT RAPIDLY DEVELOPING CONVECTIVE INHIBITION WITH
NIGHTFALL WILL LIKELY NOT BE SUPPORTIVE OF REDEVELOPMENT OF THE
CONVECTIVE LINE AS THE REMNANTS MOVE OFF THE BLUE RIDGE OF VA/NC
INTO OUR NW PIEDMONT. THE MORE FAVORABLE CONVECTIVE PARAMETERS FOR
CONVECTION CONTINUE OVER CENTRAL AND NORTHERN VA AND THIS IS WHERE
THE LINE WAS RE-FIRING AND HEADED TOWARD RICHMOND.
WE WILL KEEP LOW CHANCE POP FOR SOME RESIDUAL SHOWERS AND ISOLATED
THUNDER CHANCE FOR A FEW MORE HOURS IN THE NW-NE PIEDMONT AND FAR NE
ZONES OF THE COASTAL PLAIN... OTHERWISE PARTLY CLOUDY OVERNIGHT.
LOWS 68-73.
PREVIOUS DISCUSSION AT 730 PM...
ANOTHER... THE LAST IN THE SERIES OF CONVECTIVE COMPLEXES WAS DIVING
SOUTHEAST INTO WESTERN AND SOUTHWESTERN VIRGINIA AIMED AT NORTHERN
NORTH CAROLINA AT 725 PM. THE HIGHEST INSTABILITY RESIDED OUT AHEAD
OF THE LINE OVER VIRGINIA. THE INSTABILITY AXIS WEAKENED BUT
EXTENDED INTO THE NORTHERN AND EASTERN SECTIONS OF NC. SURFACE DEW
POINTS WERE IN THE 70S NORTH AND EAST... AND 60S IN THE SW PIEDMONT.
DEEP LAYER SHEAR WAS BEST TO OUR NORTH AS WELL... BUT 35-45KT OF
SHEAR EXTENDED OVER THE REGION NEAR THE NC/VA BORDER.
INTERESTINGLY... EVEN AS THE LINE WAS ONLY 2-3 HOURS FROM
POTENTIALLY AFFECTING A PORTION OF OUR REGION... MANY OF THE NEAR
TERM MODELS INCLUDING THE ARW AND HRRR WERE FORECASTING THE CORE OF
THE MCS TO DIVE SOUTH THEN SOUTHWEST TOWARD BOONE/BRISTOL/TRI CITIES
AREA BY LATE EVENING. THE STORM PREDICTION CENTER FELT THAT THE LINE
WOULD CONTINUE MOVING SE AND EITHER MAINTAIN ITSELF OR WEAKEN...
THEN RE-INTENSIFY AS IT HITS A FAVORABLE ENVIRONMENT MENTIONED ABOVE
IN THE VA/FAR NORTHERN NC PIEDMONT. THIS IS WHERE A SEVERE
THUNDERSTORM WATCH WAS PLACED AS FAR SOUTH AS MOUNT AIRY AND
YANCEYVILLE THROUGH 100 AM.
JUST AS IN THE PREVIOUS NW FLOW CONVECTIVE COMPLEXES AND LINES THAT
HAVE AFFECTED OUR REGION - IT WILL LIKELY HAVE TO BE NOWCAST RATHER
THAN FORECAST AS TO THE HOW IT WILL AFFECT OUR REGION. AT THE
CURRENT TIME IT APPEARS LIKELY THAT AT LEAST THE NORTH-NORTHEAST
PIEDMONT FROM THE TRIAD TO ROXBORO TO THE NORTHERN PART OF THE
TRIANGLE WILL HAVE TO DEAL WITH AT LEAST SOME GUSTY WINDS AND
LOCALLY HEAVY RAIN BETWEEN 900 PM AND MIDNIGHT.
WE WILL MAINTAIN THE CURRENT FORECAST WORDING AND THE CURRENT
HAZARDOUS WEATHER OUTLOOK UNTIL THE THREAT FROM THIS SYSTEM
DIMINISHES OR PASSES. IT APPEARS THE THREAT OF SEVERE STORMS IS
LOWEST IN THE SOUTH AND WEST (WHERE THE CONVECTIVE PARAMETERS ARE
MUCH LOWER) - DUE TO SOME NEGATIVE RESIDUAL AFFECTS OF THE SYSTEM
THAT PASSED BY THIS MORNING AND THE CURRENT ONE THAT BRUSHED BY TO
THE WEST OF ASHEVILLE.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 315 PM TUESDAY...
A MID LEVEL TROUGH IS PROGGED TO BE SHIFTING OFF THE MID ATLANTIC
COAST THROUGHOUT THE DAY ON WEDNESDAY. AS THIS DOES SO...A COLD
FRONT WILL GRADUALLY TRACK ACROSS THE REGION...EVENTUALLY SETTLING
SOUTH OF THE AREA BY WEDNESDAY NIGHT. ALL OF THIS WILL LEAD TO A
DECREASE IN CONVECTIVE COVERAGE AS THE BEST FORCING AND MOISTURE
WILL GRADUALLY BE SHIFTING OFF TO THE NORTH AND EAST OF THE AREA.
THEREFORE...WILL SHOW A GRADUAL PROGRESSION OF DECREASING PRECIP
CHANCES FROM WEST TO EAST THROUGHOUT THE DAY...HOWEVER POPS WILL BE
NO HIGHER THAN SLIGHT CHANCE. TEMPS WILL BE SLIGHTLY ABOVE NORMAL
(RANGING FROM NEAR 90 DEGREES TO THE LOWER 90S)...ALTHOUGH HUMIDITY
VALUES WILL BE LOWER THAN PREVIOUS DAYS.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 315 PM TUESDAY...
THURSDAY AND FRIDAY...HEIGHTS WILL BEGIN TO RISE OVER THE REGION AS
THE AFOREMENTIONED MID LEVEL TROUGH (SEE SHORT TERM DISCUSSION
ABOVE) PULLS FURTHER OUT TO SEA. AT THE SURFACE...A NEARLY
STATIONARY FRONT WILL REMAIN SOUTH OF THE REGION...ALLOWING HIGH
PRESSURE TO RIDGE DOWN ONTO THE AREA. ALL OF THIS WILL RESULT IN
QUIET WEATHER TO CLOSE OUT THE WORK WEEK...WITH SLIGHTLY ABOVE
NORMAL TEMPS (BUT CONTINUED LOWER RELATIVE HUMIDITIES).
SATURDAY THROUGH TUESDAY...THE SURFACE HIGH PRESSURE WILL SHIFT
OFFSHORE TO BEGIN THE WEEKEND...ALLOWING MOISTURE TO RETURN TO THE
REGION. IN ADDITION...NORTHWESTERLY FLOW ALOFT WILL BECOME RE-
ESTABLISHED OVER THE REGION GIVEN THE MID LEVEL RIDGE OVER THE DEEP
SOUTH. ALL OF THIS WILL LEAD TO INCREASING CHANCES OF PRECIP...
MOSTLY DIURNAL IN NATURE. TEMPS WILL CONTINUE TO BE ABOVE NORMAL.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 200 AM WEDNESDAY...
UPPER LEVEL TROUGH MOVING THROUGH THE AREA THIS MORNING MAY SUPPORT
AN ISOLATED SHOWER OR TWO. OTHERWISE...VFR CONDITIONS ARE EXPECTED
TO PREVAIL THROUGH THE TAF PERIOD. THE EXCEPTION WILL BE ACROSS THE
COASTAL SECTIONS...WHERE ISOLD CONVECTION WILL BE POSSIBLE INVOF THE
EXITING COLD FRONT...THOUGH ACTIVITY SHOULD REMAIN EAST/SOUTH OF THE
FAY TERMINAL.
LOOKING AHEAD: THURSDAY THROUGH SUNDAY WILL BE LESS ACTIVE THAN
PREVIOUS DAYS...WITH MORE IN THE WAY OF TYPICAL DIURNAL CONVECTION
THROUGH THE PERIOD. ASIDE FROM SOME PREDAWN MORNING
FOG/STRATUS...EXPECT PREDOMINATELY VFR CONDITIONS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...PWB
SHORT TERM...KRD
LONG TERM...KRD
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS BISMARCK ND
332 AM CDT WED JUL 15 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM CDT WED JUL 15 2015
FOCUS IN THE SHORT TERM IS ON CHANCES FOR THUNDERSTORMS WEDNESDAY.
UPPER LEVEL RIDGE REMAINS CENTERED OVER NORTH DAKOTA EARLY THIS
MORNING. THROUGH THE AFTERNOON AND EVENING THE RIDGE WILL PROPAGATE
EAST ALONG WITH A WEAK SURFACE BOUNDARY. AMPLE CAPE AND MARGINAL
BULK SHEAR VALUES WILL MOST LIKELY PRODUCE NUMEROUS THUNDERSTORMS
ACROSS WESTERN AND CENTRAL NORTH DAKOTA THIS AFTERNOON AND TONIGHT.
SHORT RANGE MODELS AS OF LATE HAVE BEEN MORE MISS THAN HIT OVER THE
LAST WEEK OR SO...HOWEVER THE PREVIOUS FEW HRRR MODEL RUNS HAVE BEEN
FAIRLY CONSISTENT WITH NUMEROUS STORMS SETTING UP FROM THE TURTLE
MOUNTAINS INTO SOUTHWESTERN NORTH DAKOTA AROUND 18 UTC AND THEN
PROPAGATING EAST. WITH THAT SAID THE HRRR HAS NOT DONE WELL WITH THE
STORMS THAT WILL NOT SEEM TO STOP ACROSS WILLIAMS AND MCKENZIE
COUNTIES EARLY THIS MORNING. THUS HAVE WENT WITH A BLEND BETWEEN THE
HRRR AND LONGER RANGE MODELS FOR TODAY THROUGH TONIGHT.
THE SPC WEDNESDAY OUTLOOK CONTINUES TO SHOW NORTH DAKOTA IN A SLIGHT
RISK FOR SEVERE THUNDERSTORMS...WITH THE MAIN RISK AS LARGE HAIL AND
GUSTY WINDS. AS OF NOW HAVE A MENTION OF SEVERE IN THE GRIDS
STARTING AT 18 UTC AND PERSISTING INTO THE NIGHT. JUDGING BY THE
POTENTIALLY STRONG STORMS ALREADY IN PLACE IN THE NORTHWEST IT IS
CERTAINLY POSSIBLE TO SEE SEVERE THUNDERSTORMS POP UP EARLY THIS
AFTERNOON.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 316 AM CDT WED JUL 15 2015
AN ACTIVE WEATHER PATTERN CONTINUES TO HIGHLIGHT THE EXTENDED
FORECAST.
THE 00 UTC GLOBAL DETERMINISTIC AND ENSEMBLE SUITES ARE IN
AGREEMENT ON QUASI-ZONAL FLOW ALOFT ACROSS THE NORTHERN PLAINS
THURSDAY AND FRIDAY TRANSITIONING TO SOUTHWEST THIS WEEKEND AS A
POSITIVELY TILTED NORTHERN CONUS AND CANADIAN ROCKIES TROUGH
MODESTLY AMPLIFIES BEFORE PROPAGATING DOWNSTREAM OF THE REGION
INTO EARLY NEXT WEEK. AS A RESULT...DAILY CHANCES FOR
THUNDERSTORMS ARE FORECAST TO CONTINUE THURSDAY THROUGH AT LEAST
SATURDAY...BEFORE A POTENTIAL DECREASE IN STORM ACTIVITY NEXT
WEEK. WHILE THE SEVERE THREAT IS NON-ZERO THURSDAY AND MORE SO ON
FRIDAY AHEAD OF THE SURFACE COLD FRONT...UNCERTAINTY IS TOO HIGH
AT THIS TIME TO ADD A SEVERE MENTION TO THE GRIDS. THIS IS IN LINE
WITH THE SPC OUTLOOK SUITE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1224 AM CDT WED JUL 15 2015
VFR CONDITIONS ARE FORECAST THROUGH 06Z TAF PERIOD. HAVE OPTED TO
PUT VCTS IN FOR ALL 5 CENTRAL AND WESTERN NORTH DAKOTA TAF SITES
STARTING BETWEEN 18Z AND 21Z. STORMS WILL PERSIST INTO THE NIGHT
BEYOND 06Z JULY 16.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...MM
LONG TERM...AYD
AVIATION...MM
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
328 AM CDT WED JUL 15 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 328 AM CDT WED JUL 15 2015
CONVECTION TIMING AND STRENGTH WILL BE THE MAIN FORECAST ISSUES
FOR THE SHORT TERM.
UPPER RIDGING CONTINUES TO BUILD OVER THE PLAINS...BUT WV LOOP
SHOWS SEVERAL WEAK EMBEDDED SHORTWAVES HEADED INTO THE REGION. SFC
LOW PRESSURE WILL BE DEVELOPING TO OUR WEST...AND SOUTH WINDS WILL
HELP KEEP PLENTY OF MOISTURE IN THE REGION. SOME STORMS HAVE
ALREADY STARTED TO DEVELOP OVER WESTERN ND IN RESPONSE TO ONE OF
THE WEAK SHORTWAVES. 06Z HRRR HAS SOME CONVECTION FIRING IN THAT
AREA...BUT SEEMS TO FIZZLE IT OUT AND DEVELOP STORMS FURTHER SOUTH
NEAR THE SD BORDER. A FEW STORMS HAVE BEEN FIRING OVER NORTHERN
MN...MOSTLY TO OUR EAST BUT SHORT RANGE MODELS PERSIST IN BREAKING
OUT SOME CONVECTION OVER THE FAR EASTERN TIER DURING THE EARLY
MORNING HOURS.
OUT OF THE SHORT RANGE MODELS THE HRRR SEEMS TO HAVE THE BEST
HANDLE ON WHAT IS CURRENTLY GOING ON...AND EVEN THEN IT IS NOT
PERFECT. THINK THAT THE STORMS OVER WESTERN ND WILL MOVE EAST
THROUGH THE MORNING...WITH THE DEVILS LAKE BASIN THE BEST SHOT OF
SEEING SOME CONVECTION THIS MORNING. THINK MORE VIGOROUS
CONVECTION WILL MOVE IN FROM THE WEST LATER THIS AFTERNOON AND
INTO THE EVENING AS A SHORTWAVE CURRENTLY OVER WESTERN WY COMES
OVER THE TOP OF THE RIDGE. MODEL SOUNDINGS HAVE CAPE VALUES OF
1000-1500 J/KG AND SHEAR VALUES AROUND 30 KTS...SO SOME SEVERE
LATER THIS AFTERNOON IS NOT OUT OF THE QUESTION DEPENDING ON HOW
THE MORNING CONVECTION PLAYS OUT. CONVECTION SHOULD MOVE EASTWARD
AND BECOME MORE WIDESPREAD AS THE UPPER SHORTWAVE COMES OUT INTO
THE PLAINS. THE MAIN SFC LOW WILL BE TO OUR SOUTH...ALTHOUGH THE
LATEST 06Z NAM BRINGS IT CLOSER TO OUR SOUTHERN COUNTIES THAN
PREVIOUS RUNS.
THURSDAY...THE MAIN UPPER SHORTWAVE THAT THE MODELS ARE PINGING ON
MOVES OFF INTO MN...BUT THE MODELS HAVE ANOTHER ONE FOLLOWING
SHORTLY FURTHER NORTH OVER OUR NORTHERN COUNTIES. MODELS HAVE A
GOOD AMOUNT OF QPF FOR MUCH OF THE DAY...SO KEPT POPS HIGH AND
TEMPS MAY BE SUPPRESSED A BIT BY ONGOING PRECIP SO HAVE MORE
READINGS IN THE UPPER 70S. DO NOT AT THIS POINT THINK THERE WILL
BE MUCH SEVERE DUE TO WEAK DEEP LAYER BULK SHEAR VALUES.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 328 AM CDT WED JUL 15 2015
THURSDAY NIGHT THROUGH FRIDAY NIGHT...MORE WEAK SHORTWAVE TROUGHS
COMING IN AS SOUTHWESTERLY FLOW ALOFT SETS UP OVER THE REGION.
TIMING OF PRECIP IS DIFFICULT TO TELL AT THIS POINT BUT HAVE A
BIT OF A BREAK LATE THURSDAY NIGHT BEFORE THE NEXT SFC TROUGH AXIS
MOVES IN FRIDAY AND SETS OFF MORE CONVECTION. KEEP POPS FAIRLY
HIGH AND TEMPS SHOULD BE NEAR SEASONAL AVERAGES ALTHOUGH SLIGHTLY
MORE MILD ON LOWS DUE TO CLOUDS AND PRECIP.
SATURDAY THROUGH TUESDAY...MODELS IN GOOD AGREEMENT WITH POSITIONING
OF UPPER LEVEL FEATURES. INDICATIONS ARE FOR A TROF DIGGING OVER
THE INTERMOUNTAIN WEST...KEEPING MORE OF A SW FLOW REGIME OVER THE
AREA. VARIOUS IMPULSES ARE EXPECTED TO PROPAGATE THRU THE
FLOW...BRINGING ENOUGH INSTABILITY TO TRIGGER SHOWERS OR STORMS
ACROSS THE AREA EACH DAY. OTHERWISE...TEMPS WILL REMAIN MAINLY ON
THE WARM SIDE...ALTHOUGH A SLIGHT COOLING MAY OCCUR NEAR THE END
OF THE PERIOD AS A WEAK UPPER TROF CROSSES ALONG THE CANADIAN
BORDER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1127 PM CDT TUE JUL 14 2015
FOLLOWED SHORT RANGE MODEL GUIDANCE KEEPING FA DRY THROUGH MOST OF
THE FORECAST PERIOD. MAY SEE SOME UPPER LEVEL CONVECTIVE DEBRIS
CLOUD COVER BUT OVERALL A VFR PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...JR
LONG TERM...JR/HOPKINS
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
141 AM EDT WED JUL 15 2015
.SYNOPSIS...
A COMPLEX FRONTAL SYSTEM WILL MOVE THROUGH THE AREA OVERNIGHT.
HIGH PRESSURE BUILDING SOUTHEAST FROM THE GREAT LAKES WILL BRING A
DRIER WEATHER PATTERN DURING THE SECOND HALF OF THE WEEK BEFORE
INCREASING HEAT AND HUMIDITY MAKE A RETURN FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
MESO ANAL AS OF 9 PM SHOWS A LOW OVER LAKE ERIE WITH A VERY
COMPLEX FRONTAL SYSTEM IN PLACE OVER THE REGION. LOW PRESSURE IS
BEGINNING TO FORM OVER THE SOUTH-CENTRAL MOUNTAINS ALONG WHAT WAS
THE WARM FRONT...AND IT SEEMS TO BE THE FOCUS MECHANISM FOR
CONVECTION THAT CONTINUES TO FIRE EVEN AT THIS HOUR.
THE HRRR KEEPS US ACTIVE THROUGH AT LEAST MIDNIGHT BEFORE
ACTIVITY BEGINS TO WANE AS THE FRONTAL SYSTEM FINALLY STARTS TO
SETTLE OFF TO THE SOUTH AND EAST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
AS THE COLD FRONT COMES THROUGH IT SHOULD BRING DRIER AIR AND MOVE
MOST OF THE STORMS TO THE SOUTHEAST. WILL LINGER HIGH CHC POPS
INTO THE MORNING ON WEDNESDAY FOR THE FAR SERN COS...THOUGH.
THE CURRENT LOW TRACK SOUTHWARD...MOVING THE FRONT THROUGH WEST
VIRGINIA. WIDESPREAD SHOWERS AND THUNDERSTORMS REMAIN POSSIBLE
TONIGHT INTO THE EARLY WEDNESDAY. IN THE WAKE OF THE FRONT EXPECT
DRIER CONDITIONS WHICH COULD LEAD TO PATCHY EARLY MORNING FOG.
IMPROVEMENT IS EXPECTED OVER MOST OF THE AREA LATE WED MORNING AND
THROUGH THE AFTERNOON. HIGHS SHOULD RECOVER CLOSE TO 80F IN THE
S...BUT KEEP AT OR BELOW 70F IN THE FAR NW.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
SHOWERS WILL END OVER SOUTHERN/EASTERN AREAS BY 00Z THURSDAY AS
THE COLD FRONT PUSHES SEWD TOWARD THE MID ATLC COAST. BEHIND THE
FRONT...A LARGE AREA OF BELOW NORMAL PW AIR WILL OVERSPREAD THE
NORTHEAST AND MID ATLANTIC STATES FROM WED NGT THROUGH
THURSDAY...ACCOMPANIED BY AN EXPANSIVE AREA OF HIGH PRESSURE
MIGRATING EWD FROM SERN CANADA INTO THE N. ATLC OCEAN...WHICH
WILL ENSURE DRY WX DURING THIS TIME. MUCH OF FRIDAY ALSO LOOKS DRY
WITH A LOW RISK OF A LATE DAY SHOWER/TSTM ACROSS THE FAR WRN/NWRN
ALLEGHENY MTNS. WED/THU NIGHTS WILL BE REFRESHINGLY COOL WITH LOWS
IN THE MID 40S TO LOW 50S AND VALLEY FOG ACROSS THE NRN TIER.
500MB HEIGHTS SHOULD STEADILY REBOUND THROUGH THE WEEKEND WITH
VERY WARM/HOT AND HUMID CONDITIONS FORECAST INTO EARLY NEXT WEEK.
CENTRAL PA IS CURRENTLY NEAR/AT THE HOTTEST TIME OF THE YEAR
/JULY 11-20/ BASED ON THE MOST RECENT 30-YEAR CLIMATE NORMALS.
HEAT INDEX VALUES MAY APPROACH 100F OVER THE LWR SUSQ VALLEY SUN-
MON WITH GUIDANCE SHOWING HIGHS AROUND 90F.
THE UPSTREAM FLOW ALOFT IS FCST TO TREND FROM QUASI-ZONAL ON THE
NRN PERIPHERY OF SRN PLAINS RIDGE...FROM THE MIDWEST THROUGH THE
GREAT LAKES...EVENTUALLY TOWARD MORE OF A WEST-NORTHWEST FLOW WITH
GENERAL TROUGHING LKLY TO CONTINUE OVER THE EASTERN QUARTER OF
NOAM. NRN STREAM S/WVS MOVING INTO THE AREA FROM THE WNW...ALONG
WITH DIURNAL INSTABILITY...MAY BE A FOCUS FOR SHOWERS/TSTMS SAT-
SUN. A BETTER FOCUS FOR PCPN SHOULD EVOLVE INTO THE MON-TUE TIME
FRAME AS A FRONTAL BOUNDARY PUSHES SEWD FROM THE GREAT LAKES.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
A COLD FRONT MOVING SE ACROSS THE REGION WILL BRING NUMEROUS SHRA
AND TSRA TO THE AREA OVERNIGHT...MAINLY FROM KUNV SOUTH AND
EASTWARD. HEAVIEST ACTIVITY CURRENTLY ALONG AND TO THE EAST OF THE
SUSQUEHANNA RIVER WITH CONVECTION MOVING NORTHEAST FROM EASTERN
MARYLAND TOWARD KLNS.
AS THE COLD FRONT MOVES EAST OF THE AREA...FOCUS LATE TONIGHT
WILL SHIFT TOWARD THE LIKELIHOOD OF LOW CIGS ACROSS THE W MTNS.
RESIDUAL LOW LVL MOISTURE ASCENDING THE ALLEGHENY MTNS WILL LIKELY
RESULT IN IFR CIGS AT KBFD AND KJST LATE TONIGHT. A LIGHT
DOWNSLOPING NW FLOW SHOULD YIELD MORE FAVORABLE CONDS FURTHER
EAST...WITH MVFR CIGS/VSBYS LIKELY LATE TONIGHT ACROSS MOST
CENTRAL PA AIRFIELDS.
LOW CIGS COULD LINGER UNTIL ARND MIDDAY WED ARND KJST. OTHERWISE...EXPECT
IMPROVING FLYING CONDS...AS NORTHERLY FLOW DRAWS DRIER AIR INTO
THE REGION. WIDESPREAD VFR CONDS EXPECTED EVERYWHERE WED AFTN.
OUTLOOK...
THU...NO SIG WX EXPECTED.
FRI...ISOLD PM TSRA IMPACTS POSS W MTNS.
SAT-SUN...SCT PM TSRA IMPACTS POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...DANGELO/CERU
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/TYBURSKI
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1135 PM CDT TUE JUL 14 2015
.DISCUSSION...
UPDATED FOR 06Z AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 758 PM CDT TUE JUL 14 2015/
.UPDATE...
UPDATE TO REMOVE SEVERE THUNDERSTORM AND FLASH FLOOD WATCHES FROM
THE MID SOUTH.
DISCUSSION...
THE POWERFUL MESOSCALE CONVECTIVE COMPLEX (MCS) THAT MOVED ACROSS
THE MID SOUTH RESULTING IN WIDESPREAD WIND DAMAGE HAS FINALLY
EXITED TO THE SOUTHEAST AND INTO CENTRAL ALABAMA. THE RAIN COOLED
AIR HAS STABILIZED THE ATMOSPHERE THIS EVENING AND ANY LINGERING
STORMS SHOULD DIMINISH LATER THIS EVENING. MODELS CONTINUE TO
SUGGEST THAT THE ADDITIONAL SHOWERS AND THUNDERSTORMS MAY DEVELOP
ACROSS NORTHEAST PORTIONS OF THE REGION LATE TONIGHT. IT APPEARS
POSSIBLE AS THE AIRMASS ATTEMPTS TO RECOVER SOME...BUT THINK THAT
COVERAGE SHOULD REMAIN LOW. MAINTAINED SLIGHT CHANCE/LOW END
CHANCE POPS AFTER MIDNIGHT...BUT MAY NEED TO REASSESS LATER THIS
EVENING AS CONFIDENCE IN THIS OCCURRING CONTINUES TO DECREASE.
ALL THREATS FOR SEVERE WEATHER AND FLASH FLOODING ACROSS THE MID
SOUTH HAVE ENDED FOR TONIGHT AND THE LATEST HWO REFLECTS THIS
THINKING. PLEASE PASS ALONG ANY WIND DAMAGE REPORTS FROM EARLIER
STORMS...IT IS GREATLY APPRECIATED.
ADDITIONAL UPDATES WILL BE PROVIDED THROUGH THE EVENING AS
NECESSARY.
JLH
&&
.PREV DISCUSSION... /ISSUED 459 PM CDT TUE JUL 14 2015/
UPDATE...
UPDATE TO INCREASE POPS ACROSS MUCH OF THE REGION AND CLEAN UP
SEVERE THUNDERSTORM WATCH PRODUCTS.
DISCUSSION...
A FORWARD PROPAGATING MESOSCALE CONVECTIVE SYSTEM (MCS) IS
ADVANCING THROUGH SOUTHERN WEST TENNESSEE AND PORTIONS OF NORTH
MISSISSIPPI. THIS SYSTEM HAS HAD A HISTORY OF WIDESPREAD AND
SOMETIMES SIGNIFICANT WIND DAMAGE WITH WIND GUSTS IN EXCESS OF 70
MPH AT TIMES. THERE HAS ALSO BEEN TRAINING THUNDERSTORMS ACROSS
WEST TENNESSEE NEAR THE I-40 CORRIDOR WHERE LOW LEVEL CONVERGENCE
IS BECOMING MAXIMIZED. THIS REGION WILL BE AN AREA WHERE HEAVY
RAINFALL AND FLASH FLOODING WILL BECOME MORE OF AN ISSUE WITH TIME
THROUGH THIS EVENING.
CONVECTION SHOULD CONTINUE TO ADVANCE THROUGH EAST ARKANSAS AND
NORTH MISSISSIPPI THROUGH THE REMAINDER OF THIS EVENING AS THE
CONVECTIVE LINE MOVES INTO A STRONGLY UNSTABLE ENVIRONMENT
CHARACTERIZED BY MLCAPE VALUES IN EXCESS OF 3500 J/KG. ALSO...A
WELL ESTABLISHED COLD POOL WILL SUSTAIN STORM STRUCTURE AND
CONTINUED WIND DAMAGE POTENTIAL IS EXPECTED. STORM COVERAGE AND
INTENSITY SHOULD DIMINISH AREAWIDE AFTER MIDNIGHT.
UPDATED PRODUCTS HAVE BEEN SENT AND WILL BE UPDATED AS NEEDED
THROUGH THE EVENING.
JLH
&&
.PREV DISCUSSION... /ISSUED 344 PM CDT TUE JUL 14 2015/
DISCUSSION...
CURRENTLY... ANOTHER WARM HUMID DAY THROUGHOUT THE MIDSOUTH. HEAT
ADVISORY CRITERIA HAS BEEN MET AT ALL 4 CLIMATE SITES AS
TEMPERATURES CLIMB INTO THE MID TO UPPER 90S. MOISTURE CONTINUES
TO POOL INTO THE MIDSOUTH AHEAD OF A CLUSTER OF THUNDERSTORMS THAT
HAVE ENTERED THE NORTHWESTERN CORNER OF OUR CWA AND WILL CONTINUE
TO MOVE SOUTHEAST TOWARDS THE MISSISSIPPI RIVER. WE ARE ALSO
MONITORING THE NORTHEASTERN PORTIONS OF THE CWA FOR CONVECTION
THAT IS THE RESULT OF WAA ALONG AN OUTFLOW BOUNDARY PRODUCED BY A
DECAYING MCS FURTHER EAST. THE HRRR FORMS A LINE OF THESE TWO
DISTURBANCES AND CARRIES THEM SOUTHWARD INTO NORTH MISSISSIPPI
BEFORE THEY BEGIN TO DIE AS WE LOSE DAYTIME HEATING. AN EXTREMELY
UNSTABLE PRE STORM AIRMASS AIR MASS EXISTS AHEAD OF THESE STORMS
THROUGHOUT THE MIDSOUTH WITH SBCAPE VALUES RANGING FROM 4500-6500
J/KG. SEVERE WIND GUSTS WILL BE THE MAIN THREAT WITH ANY STORMS
TODAY. THE WALNUT RIDGE AWOS STATION HAS ALREADY REPORTED A WIND
GUST OF 66 MPH AT 1935Z. SEVERE HAIL WILL BE A SECONDARY THREAT.
TEMPERATURES TOMORROW WILL BE 1-2 DEGREES COOLER THAN TODAY AS
CLOUD COVER ASSOCIATED WITH A WEAK COLD FRONT PROHIBIT THE TYPE OF
TEMPS THAT WE SAW TODAY. THE HEAT ADVISORY WILL BE RE-EVALUATED
DURING THE MIDNIGHT SHIFT.
TEMPERATURES INCREASE TO THE 90S ON THURSDAY THROUGH THE WEEKEND
AS THE UPPER LEVEL RIDGE SHIFTS EAST AND BECOMES CENTERED OVER
THE LOWER MISSISSIPPI RIVER VALLEY. HEAT INDICES WILL ONCE AGAIN
BECOME OPPRESSIVE FROM THURSDAY THROUGH EARLY NEXT WEEK. TEMPS AT
THE 850 MB LEVEL WILL REMAIN 22-23C. THAT CORRELATES TO
TEMPERATURES IN THE UPPER 90S AT THE SURFACE. DEWPOINTS WILL BE IN
THE LOWER TO MID 70S EACH DAY. CONFIDENT IN THE NEED FOR HEAT
ADVISORIES FOR AT LEAST A FEW IF NOT EVERY DAY THROUGHOUT THE
PERIOD.
LONG TERM MODELS AGREE ON THE UPPER RIDGE BREAKING DOWN AND
RETROGRADING WEST BY NEXT WEDNESDAY. THIS SHOULD RESULT IN COOLER
TEMPS BY MID WEEK.
JPM3
&&
.AVIATION...
WEAK COLD FRONT WILL PUSH THROUGH THE TAF SITES NEXT 24 HOURS.
CONVECTION IS EXPECTED TO REFORM BY MORNING BUT WON`T START
INTENSIFYING UNITL MIDDAY. MEM AND TUP WILL HAVE THE BEST THREAT
FOR T-STORMS IN TH AREA...WITH TEMPO SHRAS. OCCASIONAL MVFR
WEATHER DURING CONVECTION...OTHERWISE PREDOMINATELY VFR THIS
PERIOD. LIGHT WINDS WILL TURN NORTHEAST AT 4-9 KTS BEHIND FRONT.
JAB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...HEAT ADVISORY UNTIL 7 PM CDT WEDNESDAY FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI-
PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...HEAT ADVISORY UNTIL 7 PM CDT WEDNESDAY FOR DUNKLIN-PEMISCOT.
MS...HEAT ADVISORY UNTIL 7 PM CDT WEDNESDAY FOR ALCORN-BENTON MS-
CALHOUN-CHICKASAW-COAHOMA-DESOTO-ITAWAMBA-LAFAYETTE-LEE MS-
MARSHALL-MONROE-PANOLA-PONTOTOC-PRENTISS-QUITMAN-
TALLAHATCHIE-TATE-TIPPAH-TISHOMINGO-TUNICA-UNION-YALOBUSHA.
TN...HEAT ADVISORY UNTIL 7 PM CDT WEDNESDAY FOR BENTON TN-CARROLL-
CHESTER-CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-
HARDIN-HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-
MCNAIRY-OBION-SHELBY-TIPTON-WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION
NWS TUCSON AZ
340 AM MST WED JUL 15 2015
.SYNOPSIS...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS MOSTLY FROM
TUCSON EAST AND SOUTH THROUGH THURSDAY. THE COVERAGE OF SHOWERS AND
THUNDERSTORMS WILL EXPAND WEST OF TUCSON FRIDAY THROUGH SUNDAY DUE
TO INCREASED MOISTURE FROM TROPICAL SYSTEM DOLORES. NEAR NORMAL
DAYTIME TEMPERATURES WILL CONTINUE THROUGH THURSDAY FOLLOWED BY A
COOLING TREND FRIDAY INTO THIS WEEKEND. WARMER DAYTIME TEMPERATURES
WILL RETURN MONDAY INTO TUESDAY.
&&
.DISCUSSION...STRONG HIGH PRESSURE ALOFT WAS CENTERED OVER EAST
TEXAS AND A LOW AMPLITUDE TROUGH WAS OVER THE WESTERN CONUS EARLY
THIS MORNING. MEANWHILE...HURRICANE DOLORES WITH MAXIMUM SUSTAINED
WINDS OF 130 MPH WAS CENTERED NEAR 18N/110W...OR ABOUT 320 MILES
SOUTH OF CABO SAN LUCAS MEXICO AS PER THE 3 AM MDT NATIONAL
HURRICANE CENTER ADVISORY. MOISTURE PLUME AS PER WATER VAPOR IMAGERY
WILL CONTINUE MAINLY ACROSS CENTRAL/ERN SECTIONS OF THIS FORECAST
AREA INTO THURSDAY AS LITTLE CHANGE IN THE UPPER PATTERN WILL OCCUR.
FOR TODAY...SOME COMPLEXITY HAS BEEN INTRODUCED TO THE EVOLUTION OF
SHOWERS/TSTMS THIS AFTERNOON AND EVENING GIVEN THE COOLING CLOUD
TOPS/INCREASING COVERAGE OF SHOWERS/TSTMS OCCURRING AT THIS TIME
ACROSS ERN SECTIONS. THE SUBSEQUENT DEBRIS CLOUDINESS MAY LIMIT
SHOWER/TSTM CHANCES LATER TODAY...ESPECIALLY NEAR THE NEW MEXICO
BORDER. THE MOST RECENT HRRR SOLUTION FAVORS LOCATIONS SOUTH-TO-
SOUTHWEST OF TUCSON THIS AFTERNOON FOR THE BEST COVERAGE OF PRECIP.
THIS SOLUTION IS A DEVIATION FROM SEVERAL PREVIOUS HRRR SOLUTIONS...
THAT FAVORED A MORE NORTHWARD PROGRESSION OF SHOWERS/TSTMS THAT
WOULD GIVE A GREATER POTENTIAL FOR PRODUCING SOME BLOWING DUST
NORTHWEST OF TUCSON INTO SOUTH CENTRAL ARIZONA LATE THIS AFTERNOON
AND EVENING.
AT ANY RATE...THE OFFICIAL FORECAST DEPICTS SCATTERED SHOWERS/TSTMS
FROM TUCSON EWD TO THE NEW MEXICO BORDER THIS AFTERNOON/EVENING.
ISOLATED SHOWERS/TSTMS EXISTS ACROSS THE TOHONO O`ODHAM NATION AND
SOUTH CENTRAL PINAL COUNTY...WITH PRECIP-FREE CONDITIONS ACROSS WRN
PIMA COUNTY. PER COORD WITH WFO PSR...INTRODUCED PATCHY BLOWING DUST
GENERALLY NORTHWEST OF TUCSON LATE THIS AFTERNOON AND EARLY THIS
EVENING. AGAIN...THIS SCENARIO WILL DEPEND UPON A FARTHER NORTHWARD
PROGRESSION OF SHOWERS/TSTMS THAN DEPICTED BY THE LATEST HRRR
SOLUTION. THERE IS A SLIGHT CHANCE OF SHOWERS/TSTMS LATE TONIGHT AND
THUR MORNING MAINLY EAST TO SOUTH OF TUCSON...THEN ANOTHER ROUND OF
SCATTERED SHOWERS/TSTMS MAINLY FROM TUCSON EWD/SWD THUR AFTERNOON.
15/00Z GFS/ECMWF CONTINUED TO DEPICT INCREASING PRECIP WATER VALUES
TO OCCUR ESPECIALLY ACROSS WRN SECTIONS STARTING THUR NIGHT AND
CONTINUING INTO THIS WEEKEND. THE GFS DEPICTED PWATS BY MIDDAY SAT
TO BE NEAR 1.90 INCHES ACROSS WRN PIMA COUNTY TO AROUND ONE INCH
ACROSS THE WHITE MOUNTAINS. THESE VALUES ARE DOWN NEARLY 0.20 INCH
ACROSS WRN PIMA COUNTY VERSUS THE 14/00Z GFS.
THUS...HAVE OPTED TO MAKE ONLY VERY MINOR ADJUSTMENTS TO THE
INHERITED POPS FOR THIS FORECAST ISSUANCE. EXPECT SCATTERED TO
PERHAPS NUMEROUS SHOWERS/TSTMS FRI-SAT. THE COVERAGE OF SHOWERS/
TSTMS SAT WILL LIKELY FAVOR WRN SECTIONS VERSUS ERN LOCALES. THE
MAIN CONCERN WILL BE FOR MORE WIDESPREAD COVERAGE OF HEAVY RAINFALL
VERSUS THE PAST SEVERAL DAYS. BETTER RAINFALL CHANCES SHOULD
TRANSLATE NORTH OF THIS FORECAST AREA SUN. MOISTURE WILL REMAIN
ADEQUATE FOR CHANCE-CATEGORY POPS AREA-WIDE SUN.
THEREAFTER...THE GFS DEPICTED A SUBSTANTIAL DRYING TREND BY NEXT
TUE...WITH PRECIP WATER VALUES PROGGED TO RANGE FROM 0.50 - 0.75
INCH. BELIEVE THIS DRYING TREND IS TOO AGGRESSIVE...ALTHOUGH A
GRADUAL REDUCTION IN SHOWER/TSTM COVERAGE EARLY NEXT WEEK SHOULD
OCCUR. THUS...HAVE CONTINUED WITH A RETURN OF ISOLATED TO SCATTERED
SHOWERS/TSTMS MAINLY FROM TUCSON EWD/SWD BY TUE.
HIGH TEMPS TODAY AND THURSDAY WILL GENERALLY BE WITHIN A COUPLE OF
DEGS OF NORMAL FOR MUCH OF THE AREA. A COOLING TREND IS ON TAP FRI-
SAT...AND DAYTIME TEMPS SUN ARE FORECAST TO BE ABOUT 5-8 DEGS F
BELOW NORMAL. HIGH TEMPS ARE FORECAST TO RETURN CLOSE TO SEASONAL
NORMALS NEXT TUE.
&&
.AVIATION...VALID THRU 16/12Z.
EXPECT SCATTERED -TSRA/-SHRA FROM KTUS VICINITY EASTWARD AND
SOUTHWARD TO THE NEW MEXICO/INTERNATIONAL BORDERS GENERALLY AFTER
18Z TODAY AND CONTINUING INTO THIS EVENING. ISOLD -TSRA/-SHRA WILL
PREVAIL MAINLY EAST OF KTUS LATE TONIGHT INTO THURSDAY MORNING. THE
STRONGER TSRA WILL PRODUCE WIND GUSTS AROUND 35-45 KTS ESPECIALLY
THIS AFTERNOON AND EARLY THIS EVENING. OTHERWISE...CLOUD DECKS WILL
MOSTLY BE ABOVE 10K FT AGL AND SURFACE WIND WILL BE LESS THAN 10 KTS
INTO THURSDAY MORNING. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
&&
.FIRE WEATHER...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS MAINLY
FROM TUCSON EAST AND SOUTH THROUGH THURSDAY. BRIEF GUSTY WINDS AND
LOCALLY HEAVY RAINFALL WILL OCCUR WITH THE STRONGER THUNDERSTORMS.
THE COVERAGE OF SHOWERS AND THUNDERSTORMS WILL THEN EXPAND WESTWARD
FRIDAY THROUGH SUNDAY TO INCLUDE FIRE ZONE 150. A RETURN OF SHOWERS
AND THUNDERSTORMS MAINLY FROM TUCSON EAST AND SOUTH SHOULD OCCUR BY
THE MIDDLE OF NEXT WEEK. OTHERWISE...GENERALLY LIGHT TERRAIN DRIVEN
WINDS WILL PREVAIL WITH AFTERNOON GUSTS DUE TO DAYTIME HEATING.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
DISCUSSION...FRANCIS
AVIATION/FIRE WEATHER...CERNIGLIA
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
715 AM EDT WED JUL 15 2015
.Aviation...
[Through 12Z Thursday] Showers and storms are already developing
across the northeast Gulf of Mexico and adjacent coastline. Some
of the storms could affect ECP and TLH this morning prior to 15Z.
Otherwise, scattered to numerous showers and storms are expected
this afternoon with all terminals possibly affected with gusty
winds and brief IFR visibilities. More organized thunderstorms are
possible around DHN and ABY later in the afternoon, so 35 knot
gusts in a TEMPO group were maintained for those terminals. Outside
of thunderstorms, VFR conditions should generally prevail.
&&
.Prev Discussion [424 AM EDT]...
.Near Term [Through Today]...
An earlier convective line that pushed south across the northern
half of Alabama and Georgia diminished earlier tonight. However,
its effects on the boundary layer are still being observed with
a fairly expansive cold pool across the same areas - temperatures
around 70 degrees with dew points in the upper 60s. Meanwhile,
further south over our area, low-level moisture has pooled and
dew points are in the mid-upper 70s, and even into the low 80s in
some spots. Thus, the environment over our forecast area remains
relatively undisturbed and quite unstable. This is expected to set
up an active day with respect to convective activity.
Both hi-res and global models indicate considerable convective
development early this morning (10-15Z) across the far
northeastern Gulf of Mexico and into the Florida Big Bend. The
latest objective RAP analysis at 07Z indicated MLCAPE hovering
around 2500 j/kg with very little CINH over our coastal waters,
and regional radars did show some scattered convection already
developing. Hi-res models forecast thunderstorms to become quite
numerous south of a Mexico Beach to Valdosta line in the early-to-
mid morning, particularly over Taylor, Dixie, and Lafayette
Counties. PoPs were increased to 60-70% in those areas. With
precipitable water values analyzed over 2 inches, the storms could
be efficient rain producers, and hi-res models suggest some
potential for training echoes. Therefore, locally heavy rainfall
and flooding can`t be ruled out and heavy rainfall wording was
inserted into the morning forecast. The hi-res models are also
explicitly forecasting some 35-50 knot gusts, so some of the
storms may produce gusty winds as well.
The focus will then turn to the north for the afternoon and early
evening. Additional showers and storms may develop in the early-
mid afternoon along the sea breeze and/or periphery of the upper
level cloud shield associated with the morning convection.
Additionally, a cold front currently situated over Kentucky is
expected to arrive in central Alabama and central Georgia by
21-00Z. Hi-res and global models are in excellent agreement with
initiating another round of storms along that front, possibly
coalescing into one or more convective clusters/lines and then
propagating to the south into our forecast area. Those organized
linear storms, as well as any scattered early-mid afternoon storms
in areas of stronger heating across our forecast area, would pose
a risk of damaging wind gusts. NAM- and WRF-based models also show
an increase in low-level shear as surface and near-surface winds
back to the southwest and increase with the approach of the front.
Other models are less keen on that scenario, but if it were to
unfold that way there would likely be a greater threat for
organized severe storms.
.Short Term [Tonight Through Friday]...
There is a higher than normal degree of agreement among the
plethora of CAMs we have been looking at this morning that
convection will linger well into the evening hours. The latest
ECAM came in with likely PoPs across most of the region after 00Z.
While the overall severe threat will eventually diurnally ebb, the
atmosphere should remain sufficiently unstable for a threat to
last perhaps as late as midnight. Enhanced wording was maintained
in the weather grids through 04Z. Some graphics are being prepared
that will highlight the severe weather risk for today and tonight.
A surface cold front will settle to a position just north of the
forecast area on Thursday morning and may actually dip into our
northernmost zones. This boundary will couple with residual TS
outflow boundaries and the sea breeze to trigger convection in a
very unstable environment. Marginally severe storms are expected
with wind/hail the primary threat. The current PoP for Thursday is
roughly 40-50%, but the latest ECAM came in with 80-90% PoPs south
of U.S. 84, so we would expect the official forecast to trend
upward in later packages. The remnant front will remain in the
vicinity on Friday with somewhat drier air working into our
northern zones. PoPs will be slightly lower north than south.
Temps will be running a couple of degrees above normal by day and
several degrees above at night.
.Long Term [Friday Night Through Wednesday]...
The eastern upper level trough will lift eastward during this
period which should allow the ridge to edge closer to the
region. This will bring another uptick in daytime temps. There
will be a surface through in the vicinity at least through the
weekend, and of course there will be the typical mesoscale
boundaries around to trigger convection each day. Daytime PoPs
will generally hover in the 35-45% range through the period.
.Marine...
The pressure gradient across the northeastern Gulf of Mexico will
remain tighter than is typical for mid summer. The result will be
a continuation of WSW winds around 15 knots, occasionally
increasing to cautionary levels through Thursday night. Conditions
will be unsettled over the waters during this time with a few
rounds of strong to severe storms possible. By Friday, winds will
finally drop back to seasonal speeds with daily enhancements each
afternoon and evening in the sea breeze.
.Fire Weather...
Hazardous fire weather conditions are not expected over the next
several days.
.Hydrology...
Area rivers remain well below action stage and we do not
anticipate any main stem concerns. That said, some localized
flooding will be possible due to training of thunderstorms over
the next couple of days. While most areas will get lower amounts,
several inches of rain will be possible in localized areas.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 93 77 94 77 96 / 50 30 50 30 40
Panama City 88 80 89 80 90 / 30 30 40 30 40
Dothan 97 76 96 76 98 / 40 50 40 20 30
Albany 96 75 95 75 96 / 60 60 30 20 30
Valdosta 94 75 94 75 96 / 50 40 40 30 40
Cross City 88 76 91 76 93 / 60 40 50 30 40
Apalachicola 89 80 92 80 93 / 70 30 40 30 30
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AL...NONE.
GM...NONE.
&&
$$
NEAR TERM...LAMERS
SHORT TERM...WOOL
LONG TERM...WOOL
AVIATION...LAMERS
MARINE...WOOL
FIRE WEATHER...LAMERS
HYDROLOGY...WOOL
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1025 AM EDT WED JUL 15 2015
.UPDATE...
ISSUED AT 1025 AM EDT WED JUL 15 2015
14Z SFC ANALYSIS SHOWS HIGH PRESSURE BUILDING INTO EASTERN
KENTUCKY AND PROVIDING A BREATHER FROM THE ACTIVE WEATHER OF THE
PAST SEVERAL DAYS. ACCOMPANYING THE HIGH IS A BAND OF LOWER
STRATUS SINKING SOUTH THROUGH THE CWA. THANKS TO THIS MANY
LOCATIONS IN THE NORTHERN PARTS OF EAST KENTUCKY ARE STILL IN THE
UPPER 60S WHILE SPOTS TO THE SOUTH HAVE CLIMBED INTO THE LOWER AND
MIDDLE 70S. NORTHWEST TO NORTH WINDS OF 5 TO 10 KTS ARE BRINGING
IN DRIER AIR...AS WELL...WITH DEWPOINTS RUNNING ABOUT 10 DEGREES
LOWER THAN THOSE OF YESTERDAY. ON RADAR...THERE HAVE BEEN A FEW
VERY LIGHT RETURNS ACROSS THE FAR EAST OVER THE PAST COUPLE OF
HOURS...BUT IT IS DOUBTFUL THAT ANY MORE THAN A FEW SPRINKLES
MAKING IT TO THE GROUND. THE REST OF THE DAY WILL BE PARTLY CLOUDY
AND DRIER/COOLER THAN YESTERDAY THANKS TO THE CLOUDS AND NORTHERLY
SFC WINDS. THE HRRR AND...TO A CERTAIN DEGREE...THE NAM12 ARE
HINTING THAT SOME VERY LIGHT AND BRIEF SHOWERS WILL BE POSSIBLE
THROUGH THE AREA. AS THIS WILL BE INSIGNIFICANT...FOR NOW...WILL
KEEP THE POPS SUB 14 PERCENT AND ANY PCPN OUT OF THE WX
GRIDS/ZONES. HAVE UPDATED THE FORECAST MAINLY TO REMOVE THE FOG
MENTION AND ALSO TO TWEAK TEMPS/DEWPOINTS PER THE LATEST OBS AND
TRENDS. THE GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS IN
ADDITION TO A FRESHENED SET OF ZONES.
UPDATE ISSUED AT 721 AM EDT WED JUL 15 2015
9Z SURFACE ANALYSIS HAD THE FRONT MOSTLY THROUGH THE ARE AND
SHOULD MAKE IT THE REST OF THE WAY BY AROUND 12Z. A FEW STRATUS
CLOUDS ARE MOVING THROUGH AND ARE STILL EXPECTED TO LIFT OUT BY
THE AFTERNOON. NO MAJOR CHANGES NEEDED THIS UPDATE WITH MINOR
ADJUSTMENTS TO ACCOUNT FOR LATEST OBS AND TRENDS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 327 AM EDT WED JUL 15 2015
WATER VAPOR SHOWS A POTENT UPPER LOW FOR THIS TIME OF YEAR SPINNING
EAST ACROSS THE MID ATLANTIC THIS MORNING. WHILE THERE IS IS BIT
MORE IN THE WAY OF MID/UPPER LEVEL DRYING ACROSS THE OHIO VALLEY.
THEREFORE LOOKING AT REGIONAL RADAR DATA THIS MORNING SHOWS MUCH
OF THE SHOWER AND THUNDERSTORM ACTION SEEN YESTERDAY EVENING HAS
MOVED INTO THE SOUTHERN TENNESSEE VALLEY REGION THIS MORNING. THE
FRONT IS LAGGING BEHIND THIS AND THAT COUPLED WITH SOME DIVERGENCE
ALOFT GENERATED SOME ISOLATED SHOWERS IN THE FAR EAST AND
SOUTHEAST...HOWEVER THIS WILL CONTINUE SOUTHEAST OUT OF THE AREA
THIS MORNING. GIVEN THAT ACTIVITY HAS MOVED OUT OF THE REGION AND
NOT ADDITIONAL RAINFALL IS EXPECTED IN THE SHORT TERM PERIOD WILL
LET THE FLASH FLOOD WATCH EXPIRE WITH PACKAGE ISSUANCE. SOME
STRATUS IS INDICATED BY IR SAT AND UPSTREAM OBS MOVING SOUTH OUT
OF OHIO THIS MORNING AND THIS COULD SWEEP ACROSS THE REGION. ALSO
SHOULD NOTE MODEL SOUNDINGS AND TIME HEIGHTS WANT TO KEEP A BIT OF
LOWER MOISTURE IN PLACE..SO TRY TO REFLECT THIS THROUGH THE MID
MORNING TIME FRAME IN THE GRIDS. OTHERWISE DOES LOOK LIKE OVERALL
CLOUDS WILL BE ON THE DECREASE THROUGH THE DAY. THIS WILL BE A
SIGH OF RELIEF AFTER SUCH A ACTIVE WEATHER PATTERN OVER THE PAST
SEVERAL DAYS.
REST OF THE PERIOD STAYS QUIET AS MODELS STAY IN GOOD AGREEMENT
WITH HEIGHT RISES AS UPPER HIGH MEANDERS AROUND NEAR THE ARKLATEX
REGION. AT THE SURFACE A HIGH PRESSURE TRAVERSES THE GREAT LAKES
INTO SOUTHERN NEW ENGLAND. ALL OF THESE ELEMENTS WILL COMBINE TO
BRING NEAR TO BELOW NORMAL TEMPS AND MOSTLY SUNNY SKIES BY
THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 455 AM EDT WED JUL 15 2015
THE MODELS REMAIN IN GOOD AGREEMENT WITH UPPER LEVEL RIDGING
BUILDING INTO THE LOWER AND MIDDLE MISSISSIPPI VALLEY THROUGH THE
FIRST HALF OF THE WEEKEND...BEFORE ANOTHER TROUGH SHIFTS EAST
ACROSS THE NORTHERN CONUS...SUPPRESSING THE RIDGE TO THE SOUTH AND
SOUTHWEST. THERE ARE MORE MODEL DIFFERENCES WITH REGARDS TO THE
STRENGTH OF THE APPROACHING TROUGH...WITH THE GFS ON THE WEAKER
SIDE...WHILE THE ECMWF IS MORE ROBUST. AS SUCH...FOLLOWED THE
BLEND PRETTY CLOSE.
FOR EASTERN KENTUCKY...PLENTY OF HEAT AND HUMIDITY WILL BE ON TAP
FROM FRIDAY THROUGH MONDAY...WITH HIGHS AROUND 90 AND LOWS AROUND
70. HEAT INDICES WILL GENERALLY PEAK IN THE 95 TO 100 DEGREE RANGE
FROM SATURDAY THROUGH MONDAY. TEMPERATURES WILL THEN COOL OFF A
BIT ON TUESDAY...WITH HIGHS DROPPING BACK INTO THE MID AND UPPER
80S. ALONG WITH THE HEAT AND HUMIDITY...WILL BE THE RETURN OF
SHOWER AND THUNDERSTORM CHANCES...GENERALLY PEAKING DURING THE
AFTERNOON AND EARLY EVENING HOURS. THE BEST POPS WILL ARRIVE EARLY
NEXT WEEK AS A COLD FRONT SHIFTS SOUTHEAST ACROSS THE AREA. STUCK
FAIRLY CLOSE TO BLENDED GUIDANCE...ALTHOUGH DID UNDERCUT POPS A
BIT MORE DURING PERIODS OF WEAKER FORCING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 700 AM EDT WED JUL 15 2015
MUCH BETTER PERIOD IS SHAPING UP OVERALL FOR THIS TAF PERIOD
COMPARED TO THE PAST COUPLE OF DAYS. WHILE CONFIDENT A FEW PARTS
OF THE AREA ARE SEEING AT LEAST MVFR VIS...MOST SITES HAVE BEEN
ABLE TO KEEP MOSTLY VFR IN THAT REGARD OVERNIGHT. THIS HAS BEEN
AIDED BY SOME STRATUS THAT DROPPED SOUTHWARD OUT OF OHIO
OVERNIGHT. THIS WILL PLAGUE PORTIONS OF THE REGION THROUGH THE
MORNING HOURS...HOWEVER DOES APPEAR THIS WILL BE MOSTLY MVFR
CEILINGS. OTHERWISE THE NEXT CONCERN WILL BE FOG OR NOT TO FOG
TONIGHT. DID GO AHEAD AND LEAN IN THAT DIRECTION...BUT STILL NOT
CONFIDENT HOW THAT WILL SHAPE UP OVERALL. GIVEN HIGH PRESSURE AND
BUILDING HEIGHTS EXPECTING GENERALLY LIGHT WINDS OVERALL.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...DJ
LONG TERM...GEOGERIAN
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1007 AM CDT WED JUL 15 2015
.UPDATE...LATEST RUC CONFIRMING SUBSIDENCE EFFECTS FROM DYNAMIC
HIGH PRESSURE FROM THE UPPER LEVELS. ADJUSTED TEMPS UP FOR
INTERIOR AREAS FROM GUIDANCE. CLOSER TO THE COAST, ONLY A TWEAK
HIGHER. COMBINED WITH UPDATED DEW POINTS, HEAT INDICES APPROACH
BUT DO NOT REACH ADVISORY LEVELS BUT WILL MONITOR THIS. REMAINDER
OF THE FORECAST ON TRACK WITH POSSIBLILITY OF ISOLD SHOWERS FOR
ACADIANA THIS AFTERNOON...NOT ENOUGH TO MENTION IN THE ZONES.
SWEENEY
&&
.PREV DISCUSSION... /ISSUED 546 AM CDT WED JUL 15 2015/
AVIATION...STRONG HIGH PRESSURE AT THE SURFACE AND ALOFT WILL
MAINTAIN A DRY WEATHER PATTERN ALONG WITH VFR. WINDS WILL REMAIN
LIGHT AND GENERALLY FROM THE WEST TO SOUTHWEST.
PREV DISCUSSION... /ISSUED 359 AM CDT WED JUL 15 2015/
DISCUSSION...
FAIRLY TYPICAL SUMMER NIGHT ACROSS THE FORECAST AREA WITH
TEMPERATURES IN THE MID 70S...AND A FEW SMALL NOCTURNAL SHOWERS
TRYING TO FORM OFF THE LOWER ACADIANA COAST.
LATEST WATER VAPOR IMAGERY STILL INDICATES AN UPPER LEVEL RIDGE
HANGING IN OVER THE REGION WITH DRY AND SUBSIDENT AIR IN THE MID
AND UPPER LEVELS. THIS IS CONFIRMED BY THE 15/00Z UPPER AIR
SOUNDING FROM KLCH WITH A BELOW NORM PWAT READING OF 1.3 INCHES
AND MEAN RH AROUND 40 PERCENT...WITH THE MID LEVEL RH AT 27
PERCENT. RECENT GPS-MET INTEGRATED PWAT VALUES AROUND THE AREA
SHOW NOT MUCH CHANGE WITH READINGS STILL FROM ROUGHLY 1.25 INCHES
TO 1.4 INCHES.
MOISTURE VALUES ARE PROGGED TO STAY ROUGHLY THE SAME FOR THE NEXT
FEW DAYS AS THE MID/UPPER LEVEL RIDGE CONTINUES TO HOLD IN PLACE.
MID LEVEL MOISTURE LOOKS TO REMAIN ON THE LOW SIDE WITH VALUES IN
THE 30 PERCENT RANGE. THIS SHOULD PRECLUDE ANY SIGNIFICANT SHOWER
ACTIVITY...ALTHOUGH ONE OR TWO ISOLATED CELLS MAY FORM IN THE MAX
DAYTIME HEATING OVER THE COASTAL MARSHES WHERE SEA BREEZE
CONVERGENCE AND ATCHAFALAYA BASIN CONVERGENCE OCCURS...BUT
PROBABILITY LOW ENOUGH (BELOW 15 PERCENT) TO MENTION.
WITH SOUTHERLY SURFACE WINDS...LOW LEVEL MOISTURE WILL BE PLENTY
TO HELP BRING ABOUT SUMMERTIME HOT AND MUGGY CONDITIONS. ENOUGH
MIXING HAS BEEN OCCURRING DURING THE AFTERNOON HOURS TO KEEP HEAT
INDEX READINGS JUST IN CHECK...WITH A MAJORITY OF THE REPORTING
SITES SEEING 100F TO 102F WITH ISOLATED SPOTS FROM 103F TO 106F.
PERSISTENCE LOOKS LIKE THE WAY TO GO HERE...SO VALUES WILL BE JUST
BELOW HEAT ADVISORY CRITERIA. WILL MAKE MENTION IN THE HAZARDOUS
WEATHER OUTLOOK OF THE HEAT INDEX READINGS BETWEEN 102F AND 106F
DURING THE AFTERNOON HOURS.
BY THE WEEKEND...PROGS HINTING AT THE MID/UPPER LEVEL RIDGE
SLIGHTLY WEAKENING...WITH THE GFS MORE INCLINED TO BRING SOME MID
LEVEL MOISTURE BACK INTO THE REGION. WITH THIS...WILL INTRODUCE
ONLY SLIGHT POPS FOR SATURDAY AND SUNDAY FOR EASTERN PORTIONS
(MAINLY LOWER ACADIANA.) WITH CHANCES FOR SHOWERS EXPANDING
WESTWARD TO INCLUDE A MAJORITY OF THE FORECAST AREA EARLY TO MID
PART OF NEXT WEEK. STILL POPS ONLY IN THE 20-30 PERCENT RANGE.
RUA
MARINE...
SURFACE HIGH PRESSURE IS CENTERED OVER THE EASTERN GULF OF MEXICO.
THIS HIGH WILL RIDGE ACROSS THE NORTHERN GULF OF MEXICO FOR THE
NEXT SEVERAL DAYS. THEREFORE...NO REAL CHANGE FOR THE COASTAL
WATERS AS FAR AS WINDS AND SEAS GOES...WITH MAINLY LIGHT SOUTHWEST
TO SOUTH WINDS AND LOW SEAS. A FEW MORE SHOWERS AND THUNDERSTORMS
MAY BEGIN TO DEVELOP OVER THE WEEKEND OFF THE LOWER ACADIANA
WATERS...AS AN UPPER LEVEL HIGH SHOWS SIGNS OF WEAKENING.
RUA
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 99 74 95 75 / 0 0 10 0
LCH 94 77 93 78 / 10 0 10 10
LFT 95 77 94 77 / 10 0 10 0
BPT 94 77 94 77 / 10 0 10 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
PUBLIC...11
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1051 AM CDT Wed Jul 15 2015
.MESOSCALE DISCUSSION...
Issued at 1050 AM CDT WED JUL 15 2015
Challenging forecast this morning in the short term. Severe
convective cluster that developed yesterday in eastern Colorado
made it to just south of Kansas City before rapidly dissipating
this morning, despite the presence of a very unstable airmass.
Outflow from this cluster is now beginning to enter the central
Missouri portion of the CWA, with some persistent but so far weak
convection noted along it. As mentioned, the airmass ahead of this
feature appears to be very unstable, with dewpoints in the mid to
even upper 70s, and MLCAPE of 3000+ J/KG. In addition, 12Z SGF
RAOB measured low level theta-e differentials of 39K, with SPC
objective analysis suggesting widespread 30-40K values in place.
This should contribute to a somewhat significant downburst wind
threat IF convection can manage to get organized going into the
afternoon. The latest HRRR seems to hint at an uptick in coverage,
but model performance has not been particularly impressive as of
late.
If things can get going, areas from Truman Lake and Lake of the
Ozarks south toward West Plains and Eminence would be most likely
to see convection this afternoon.
The other challenge continues to be heat indices this afternoon,
and just how much cloud cover and convection will affect readings.
Far southwestern Missouri and southeastern Kansas should see the
least impact from cloud cover, with current expectations of seeing
heat index values between 103 and 105. Will hold off on a Heat
Advisory for now, but will watch trends closely going into the
afternoon hours.
&&
.SHORT TERM...(Today and Tonight)
Issued at 340 AM CDT WED JUL 15 2015
Another seasonably hot and muggy day is in store with again the
potential for scattered convection.
A weak boundary augmented by the convective complex on Tuesday
stretched from northwest to southeast north central Kansas into
far southwestern Missouri and will begin a slow retreat to the
northeast today. Meanwhile a weak perturbation will track from
western Kansas and around the northern periphery of the upper
level ridge into northern Missouri this afternoon. The features will
interact with strong destabilization at the surface to support the
potential for convection across much of the area today.
Meanwhile, an ongoing convective complex was pushing across north
central Kansas early today and Corfidi vectors suggest it will
take a southeastward turn later this morning and ride down the
rich theta-e axis into southwestern Missouri.
Mixed layer CAPE will approach 4500 J/KG today along and just
west of the surface boundary across west central and southwestern
Missouri where moisture pooling is expected. Deep layer shear will
be 25 to 30 kts while Theta-E differentials near 40 Celsius.
These factors will support vigorous updrafts and the potential for
strong to severe storms with locally damaging winds the primary
risk. If the convective complex remains intact then the potential
for damaging winds will increase.
High temperatures in the lower 90s coupled with surface dewpoints
in the lower and middle 70s will again yield uncomfortable heat
indicies with values from near 100 to around 105 degrees. The
highest heat indicies will occur within an axis of moisture
pooling just west of the boundary from west central Missouri into
southeastern Kansas and southwestern Missouri.
However the coverage and associated cloud cover could limit
heating at least in localized areas. With the uncertainty of the
coverage of convection including the evolution of the convective
complex, I have held off on issuing a Heat Advisory at this time.
A shorter fuse Heat Advisory may be issued late this morning based
on convective trends.
.LONG TERM...(Thursday through Tuesday)
Issued at 340 AM CDT WED JUL 15 2015
Seasonably hot and humid weather is expected the remainder of the
week and into weekend as the subtropical remains parked over the
lower Mississippi River Valley. Will have to watch for the chance
for isolated convection but widespread rainfall is not expected.
The upper ridge will retrograde to the west early next week
allowing a front to drop southward through the area on Monday.
This will bring an increased coverage of showers and
thunderstorms.
&&
.AVIATION...(For the 12Z TAFS through 12Z Thursday Morning)
Issued at 600 AM CDT WED JUL 15 2015
For the KSGF, KJLN, and KBBG TAFS: A complex of storms is currently
pushing east across northeastern Kansas early this morning. There
are indications that this complex of storms will start to push
southeastward to southward this morning and push into the area
this afternoon. There are still questions on the exact track of
these storms but given the current expectation the better
potential will be at the KSGF and KBBG TAF sites.
Given a very unstable air mass isolated to scattered storms will still
be possible across areas not affected by this complex this
afternoon/early evening, but will not be widespread. The
atmosphere will be supportive of strong gusty winds along with
brief heavy rain reducing the visibility with any storms that
occurs this afternoon into early this evening.
Otherwise outside of convection VFR conditions are expected with
a light southerly breezy today and tonight.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
MESOSCALE...Boxell
SHORT TERM...Foster
LONG TERM...Foster
AVIATION...Wise
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1044 AM CDT WED JUL 15 2015
.UPDATE...
ISSUED AT 1019 AM CDT WED JUL 15 2015
UPDATED GRIDS/FORECAST FOR ONGOING TRENDS AND EXPECTED TRENDS THE
NEXT FEW HOURS.
THE FORECAST IS CHALLENGING TODAY. SOME TRENDS SEEM TO BE
EMERGING. THIS STRONG MCV /MESOSCALE CONVECTIVE VORTEX/ WHICH
RESULTED FROM THE LARGE RAIN/STORM AREA LATE NIGHT...IS NOW
WRAPPING THINGS UP IN THE NORTHEAST PART OF THE FORECAST AREA.
DO BELIEVE THAT TREND WILL CONTINUE...WITH MAYBE A BIT OF
REDEVELOPMENT IN THAT REGION EARLY THIS AFTERNOON BUT MAY NOT
BE MORE THAN A FEW SHOWERS.
THE MCV IS STRONG...AND IS PRODUCING A STRONG SUBSIDENT REGION
IN ITS WAKE...WHICH WILL BE A DETERRENT TO AFTERNOON THUNDERSTORM
DEVELOPMENT FOR A LARGE PART OF THE AREA. THE AFTERNOON SEVERE
RISK IS LESS...SIMPLY BECAUSE WE ARE GOING TO HAVE TROUBLE
OVERCOMING THE SUBSIDENT WAKE OF THE MCV...WHICH HAS ALSO BROUGHT
SOME MORE STABLE MID-LEVEL LAPSE RATES THE NEBRASKA COUNTIES. DID
LOWER PRECIPITATION CHANCES MANY AREAS TODAY.
TO THE SOUTH...IN NORTH CENTRAL KANSAS...THIS MAY BE A MORE
ENLIGHTENED AREA FOR THUNDERSTORM DEVELOPMENT LATE THIS AFTERNOON
AND EVENING. THERE IS A WEAK SURFACE TROF ACCESS FROM KHLC TO WEST
OF KGCK...AND THE HRRR HINTS AT DEVELOPMENT IN THAT REGION...AND
THE 4KM NAM FIRES THAT LINE AS WELL TOWARD EVENING. ITS A TOUGH
CALL...BUT ITS SEEMS A MORE FAVORED AREA FOR A STRONG/SEVERE
STORM WOULD BE THE NORTH CENTRAL KANSAS REGION...POSSIBLY UP TO
SUPERIOR AND HEBRON.
IN GENERAL...A MORE WIDESPREAD SEVERE RISK SEEMS TO HAVE
DIMINISHED FOR MUCH OF THE AREA DUE TO THE MCV PASSAGE...
BUT STILL NOT TOTALLY OUT OF THE FORECAST ACROSS THE
SOUTH WHERE MORE FAVORABLE INSTABILITY...SHEAR AND SOME
WEAK CONVERGENCE MAY BE SUFFICIENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 440 AM CDT WED JUL 15 2015
PORTIONS OF THE AREA CONTINUE TO BE AFFECTED BY A COMPLEX OF
SHOWERS/THUNDERSTORMS EARLY THIS MORNING...MAINLY ALONG AND W/SW
OF A LXN TO JEWELL/KS LINE. DRIVEN BY AN UPPER LEVEL SHORTWAVE
DISTURBANCE AND MOISTURE/WARM AIR ADVECTION ASSOCIATED WITH AN
INCREASED LLJ...THIS COMPLEX HASNT EXACTLY BEEN MOVING QUICKLY TO
THE E/NE...THOUGH THE STRONGEST PORTION WHICH SHIFTED ACROSS
ROOKS/OSBORNE/MITCHELL COUNTIES IS WORKING ITS WAY OUT OF THE CWA.
AT THE SFC...A PRETTY WEAK PATTERN IS IN PLACE...WITH AN AREA OF
LOWER PRESSURE OVER THE WRN HALF OF KS...ANY BOUNDARIES THAT HAD
BEEN IN PLACE ARE BEING/WILL BE AFFECTED BY ONGOING ACTIVITY.
THE PRIMARY FORECAST FOR THE SHORT TERM LIES WITH PRECIPITATION
CHANCES AND POTENTIAL FOR SEVERE WEATHER. WANT TO STATE RIGHT OFF
THAT OVERALL CONFIDENCE IN EXACTLY HOW THINGS ARE GOING TO PLAY
OUT OVER THE NEXT 12-18 HOURS IS NOT HIGH. THINKING IS THAT THE
COMPLEX CURRENTLY SHIFTING THROUGH THE REGION WILL CONTINUE TO DO
SO THIS MORNING...AND SHOULD GIVE A CHUNK OF THE CWA AT LEAST
SOMEWHAT OF A BREAK IN THE ACTION TODAY. THERE ARE A FEW
DIFFERENCES BETWEEN MODELS AS WE GET INTO THIS AFTERNOON/EVENING
LOOKING AT QPF OUTPUT...VARYING BETWEEN NOT MUCH TO THE NEXT ROUND
AFFECTING MUCH OF THE CWA.
BROAD UPPER LEVEL SHORTWAVE TROUGHING LOOKS TO REMAIN IN THE
REGION FOR MUCH OF THE PERIOD...WITH MODELS SOWING SFC LOW
PRESSURE DEEPENING SOME OVER WRN PORTIONS OF KS LATER TODAY. STILL
LOOKING AT THE POTENTIAL FOR A SFC TROUGH AXIS/WARM FRONTAL
BOUNDARY TO EXTEND FROM THAT WRN SFC LOW THROUGH PORTIONS OF THE
CWA...BUT CONFIDENCE IN WHERE EXACTLY THAT MAY SET UP IS LOW...AND
WONT BE MORE APPARENT UNTIL THIS ONGOING ACTIVITY SHIFTS OUT AND
CAN SEE HOW OUTFLOW BOUNDARIES AFFECT THINGS. IF THE AREA GETS A
CHANCE TO "RECOVER" THROUGH THE DAY FROM CURRENT
CONDITIONS...MODELS CONTINUE TO SHOW AN AXIS OF STRONG INSTABILITY
DEVELOPING NEAR/NORTH OF THAT BOUNDARY WITH MOISTURE POOLING.
WHILE CURRENT DEEPER LAYER SHEAR IS WEAK...THAT IS EXPECTED TO
IMPROVE SOME WITH TIME...WITH LOW LEVEL SHEAR ALSO PICKING UP THIS
EVENING AS THE LLJ INCREASES. THE CWA SITS IN THE SPC DAY 1 SLIGHT
RISK AREA...WITH ALL MODES OF SEVERE WEATHER STILL A POSSIBILITY.
THOUGH HAIL/WINDS/HEAVY RAIN LOOK TO BE THE PRIMARY HAZARDS...CANT
COMPLETELY RULE OUT THE TORNADO THREAT WITH MORE THAN SUFFICIENT
INSTABILITY/GOOD LOWER LEVEL MOISTURE AND SFC BOUNDARIES IN THE
AREA.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 440 AM CDT WED JUL 15 2015
THE BIGGEST ISSUE REVOLVES AROUND DETERMINING CHANCE OF
PRECIPITATION THROUGHOUT MOST OF THE LONG TERM FORECAST AS WELL AS
STRONG/SEVERE THUNDERSTORM POTENTIAL.
FLOW WILL REMAIN MAINLY ZONAL AS WE REMAIN UNDER CONSIDERABLE
INFLUENCE OF THE SUBTROPICAL HIGH/RIDGE IN THE SOUTH. A SURFACE
TROUGH WILL LIKELY BE DRAPED SOMEWHERE OVER THE CWA...WHICH WILL
PROVIDE A FOCUS FOR NEW THUNDERSTORM DEVELOP BY LATE AFTERNOON AND
INTO THE EVENING AS THE HEAT OF THE DAY WILL INCREASE
INSTABILITY. LEFTOVER OUTFLOW BOUNDARIES WILL BE ANOTHER
POSSIBILITY FOR A FOCUS OF CONVECTION. AT ANY
TIME...ESSENTIALLY...A LOW-AMPLITUDE WAVE WILL BE POSSIBLE WITHIN
ZONAL FLOW WHICH WILL ALSO HELP SPARK CONVECTION. A SIMILAR
SCENARIO EXISTS FOR FRIDAY AFTERNOON/NIGHT. STRONG TO MARGINALLY
SEVERE THUNDERSTORMS WILL BE POSSIBLE FOR THURSDAY THROUGH FRIDAY
NIGHT...BUT THIS WILL BE LARGELY DIURNALLY DRIVEN AS DEEP LAYER
SHEAR WILL BE GENERALLY AROUND 30 KTS...WHICH IS NOT ALL THAT
IMPRESSIVE.
NO HUGE CHANGES TO THE GENERAL PATTERN HERE...EXCEPT FOR A
NORTHERN STREAM SHORTWAVE TROUGH TREKING THROUGH THE
NORTHERN/CENTRAL PLAINS SUNDAY/SUNDAY NIGHT WHICH MAY COOL DOWN
TEMPERATURES TO NEAR NORMAL. I NUDGED UP TEMPERATURES A BIT FOR
THURSDAY/FRIDAY COMPARED TO THE PREVIOUS FORECAST. ITS STILL A BIT
EARLY TO DETERMINE STRONG/SEVERE THUNDERSTORM CHANCES PAST FRIDAY
NIGHT.
&&
.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 619 AM CDT WED JUL 15 2015
SHIELD OF SHOWERS/THUNDERSTORMS CONTINUES TO SLIDE NE ACROSS THE
AREA THIS MORNING...AND WILL AFFECT BOTH TERMINAL AREAS OVER THE
NEXT COUPLE OF HOURS. UPSTREAM OBS HAVE REMAINED VFR EVEN WITH
THIS PRECIP MOVING THROUGH AND KEPT THAT TREND IN PLACE IN THE
TAF. BY LATE THIS MORNING THIS MAIN AREA IS EXPECTED TO HAVE MOVED
OUT OF THE TERMINAL AREAS...AND SHOULD SEE A BREAK IN ACTIVITY.
LATER THIS AFTERNOON/EVENING...THERE WILL BE ANOTHER CHANCE FOR
THUNDERSTORM ACTIVITY...BUT OF UNCERTAINTIES WITH THE OVERALL
COVERAGE AND TIMING...KEPT MENTION AS VCTS FOR NOW. THE SFC
PATTERN WILL KEEP WINDS FAIRLY LIGHT THROUGH THE PERIOD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...NOAA/NWS/MORITZ
SHORT TERM...ADP
LONG TERM...HEINLEIN
AVIATION...ADP
AREA FORECAST DISCUSSION
NWS BISMARCK ND
858 AM CDT WED JUL 15 2015
.UPDATE...
ISSUED AT 846 AM CDT WED JUL 15 2015
THUNDERSTORMS CONTINUE OVER CENTRAL NORTH DAKOTA WITH CURRENT WAVE
MOVING THROUGH. UPPER LEVEL ANALYSIS SHOWS ANOTHER PAIR OF WAVES
APPROACHING THE AREA WITH THE FIRST ONE OVER EASTERN MONTANA AND
THE SECOND ONE OVER WESTERN MONTANA/WYOMING INTO EASTERN IDAHO.
THEREFORE...HAVE SPREAD THUNDERSTORM CHANCES ACROSS THE AREA
THROUGH THE REMAINDER OF THE DAY. STORMS HAVE BEEN REMAINING UNDER
SEVERE LIMITS THIS MORNING THOUGH THERE IS STILL SOME POTENTIAL
FOR SEVERE IN THE AFTERNOON/EARLY EVENING AS INSTABILITY INCREASES
AND SHEAR REMAINS MARGINAL.
UPDATE ISSUED AT 646 AM CDT WED JUL 15 2015
INCORPORATED RADAR TRENDS THROUGH 1145 UTC...BLENDED TO A TIME
LAGGED ENSEMBLE OF THE 08-10 UTC HRRR ITERATIONS INTO THE
AFTERNOON AND SUPPORTED BY THE 06 UTC GFS WHICH HAVE HAD THE BEST
DEPICTION OF MORNING CONVECTION THUS FAR.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM CDT WED JUL 15 2015
FOCUS IN THE SHORT TERM IS ON CHANCES FOR THUNDERSTORMS WEDNESDAY.
UPPER LEVEL RIDGE REMAINS CENTERED OVER NORTH DAKOTA EARLY THIS
MORNING. THROUGH THE AFTERNOON AND EVENING THE RIDGE WILL PROPAGATE
EAST ALONG WITH A WEAK SURFACE BOUNDARY. AMPLE CAPE AND MARGINAL
BULK SHEAR VALUES WILL MOST LIKELY PRODUCE NUMEROUS THUNDERSTORMS
ACROSS WESTERN AND CENTRAL NORTH DAKOTA THIS AFTERNOON AND TONIGHT.
SHORT RANGE MODELS AS OF LATE HAVE BEEN MORE MISS THAN HIT OVER THE
LAST WEEK OR SO...HOWEVER THE PREVIOUS FEW HRRR MODEL RUNS HAVE BEEN
FAIRLY CONSISTENT WITH NUMEROUS STORMS SETTING UP FROM THE TURTLE
MOUNTAINS INTO SOUTHWESTERN NORTH DAKOTA AROUND 18 UTC AND THEN
PROPAGATING EAST. WITH THAT SAID THE HRRR HAS NOT DONE WELL WITH THE
STORMS THAT WILL NOT SEEM TO STOP ACROSS WILLIAMS AND MCKENZIE
COUNTIES EARLY THIS MORNING. THUS HAVE WENT WITH A BLEND BETWEEN THE
HRRR AND LONGER RANGE MODELS FOR TODAY THROUGH TONIGHT.
THE SPC WEDNESDAY OUTLOOK CONTINUES TO SHOW NORTH DAKOTA IN A SLIGHT
RISK FOR SEVERE THUNDERSTORMS...WITH THE MAIN RISK AS LARGE HAIL AND
GUSTY WINDS. AS OF NOW HAVE A MENTION OF SEVERE IN THE GRIDS
STARTING AT 18 UTC AND PERSISTING INTO THE NIGHT. JUDGING BY THE
POTENTIALLY STRONG STORMS ALREADY IN PLACE IN THE NORTHWEST IT IS
CERTAINLY POSSIBLE TO SEE SEVERE THUNDERSTORMS POP UP EARLY THIS
AFTERNOON.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 316 AM CDT WED JUL 15 2015
AN ACTIVE WEATHER PATTERN CONTINUES TO HIGHLIGHT THE EXTENDED
FORECAST.
THE 00 UTC GLOBAL DETERMINISTIC AND ENSEMBLE SUITES ARE IN
AGREEMENT ON QUASI-ZONAL FLOW ALOFT ACROSS THE NORTHERN PLAINS
THURSDAY AND FRIDAY TRANSITIONING TO SOUTHWEST THIS WEEKEND AS A
POSITIVELY TILTED NORTHERN CONUS AND CANADIAN ROCKIES TROUGH
MODESTLY AMPLIFIES BEFORE PROPAGATING DOWNSTREAM OF THE REGION
INTO EARLY NEXT WEEK. AS A RESULT...DAILY CHANCES FOR
THUNDERSTORMS ARE FORECAST TO CONTINUE THURSDAY THROUGH AT LEAST
SATURDAY...BEFORE A POTENTIAL DECREASE IN STORM ACTIVITY NEXT
WEEK. WHILE THE SEVERE THREAT IS NON-ZERO THURSDAY AND MORE SO ON
FRIDAY AHEAD OF THE SURFACE COLD FRONT...UNCERTAINTY IS TOO HIGH
AT THIS TIME TO ADD A SEVERE MENTION TO THE GRIDS. THIS IS IN LINE
WITH THE SPC OUTLOOK SUITE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 646 AM CDT WED JUL 15 2015
THUNDERSTORMS WILL BE SPREAD ACROSS NORTH DAKOTA THROUGHOUT THE 12Z
TAF PERIOD. AT THIS TIME SITES KDIK...KBIS...AND KMOT HAVE THE
GREATEST CHANCE OF BEING IMPACTED THIS MORNING AND
AFTERNOON...WITH LESSER CHANCES FOR KISN AND KJMS.UNLESS IMPACTED
BY A THUNDERSTORM VFR CONDITIONS ARE EXPECTED FOR THE 12Z TAF
CYCLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...MM
LONG TERM...AYD
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
654 AM CDT WED JUL 15 2015
.UPDATE...
ISSUED AT 653 AM CDT WED JUL 15 2015
EXPANDED THE PATCHY FOG MENTION A BIT FURTHER ACROSS THE NORTHERN
COUNTIES. IT HAS BEEN DENSE IN SOME SPOTS BUT LOOKING AT WEB CAMS
IT SEEMS THAT THE DENSE STUFF IS RATHER PATCHY SO WILL LEAVE ANY
HEADLINES ALONE FOR NOW. MADE A FEW ADJUSTMENTS TO POPS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 328 AM CDT WED JUL 15 2015
CONVECTION TIMING AND STRENGTH WILL BE THE MAIN FORECAST ISSUES
FOR THE SHORT TERM.
UPPER RIDGING CONTINUES TO BUILD OVER THE PLAINS...BUT WV LOOP
SHOWS SEVERAL WEAK EMBEDDED SHORTWAVES HEADED INTO THE REGION. SFC
LOW PRESSURE WILL BE DEVELOPING TO OUR WEST...AND SOUTH WINDS WILL
HELP KEEP PLENTY OF MOISTURE IN THE REGION. SOME STORMS HAVE
ALREADY STARTED TO DEVELOP OVER WESTERN ND IN RESPONSE TO ONE OF
THE WEAK SHORTWAVES. 06Z HRRR HAS SOME CONVECTION FIRING IN THAT
AREA...BUT SEEMS TO FIZZLE IT OUT AND DEVELOP STORMS FURTHER SOUTH
NEAR THE SD BORDER. A FEW STORMS HAVE BEEN FIRING OVER NORTHERN
MN...MOSTLY TO OUR EAST BUT SHORT RANGE MODELS PERSIST IN BREAKING
OUT SOME CONVECTION OVER THE FAR EASTERN TIER DURING THE EARLY
MORNING HOURS.
OUT OF THE SHORT RANGE MODELS THE HRRR SEEMS TO HAVE THE BEST
HANDLE ON WHAT IS CURRENTLY GOING ON...AND EVEN THEN IT IS NOT
PERFECT. THINK THAT THE STORMS OVER WESTERN ND WILL MOVE EAST
THROUGH THE MORNING...WITH THE DEVILS LAKE BASIN THE BEST SHOT OF
SEEING SOME CONVECTION THIS MORNING. THINK MORE VIGOROUS
CONVECTION WILL MOVE IN FROM THE WEST LATER THIS AFTERNOON AND
INTO THE EVENING AS A SHORTWAVE CURRENTLY OVER WESTERN WY COMES
OVER THE TOP OF THE RIDGE. MODEL SOUNDINGS HAVE CAPE VALUES OF
1000-1500 J/KG AND SHEAR VALUES AROUND 30 KTS...SO SOME SEVERE
LATER THIS AFTERNOON IS NOT OUT OF THE QUESTION DEPENDING ON HOW
THE MORNING CONVECTION PLAYS OUT. CONVECTION SHOULD MOVE EASTWARD
AND BECOME MORE WIDESPREAD AS THE UPPER SHORTWAVE COMES OUT INTO
THE PLAINS. THE MAIN SFC LOW WILL BE TO OUR SOUTH...ALTHOUGH THE
LATEST 06Z NAM BRINGS IT CLOSER TO OUR SOUTHERN COUNTIES THAN
PREVIOUS RUNS.
THURSDAY...THE MAIN UPPER SHORTWAVE THAT THE MODELS ARE PINGING ON
MOVES OFF INTO MN...BUT THE MODELS HAVE ANOTHER ONE FOLLOWING
SHORTLY FURTHER NORTH OVER OUR NORTHERN COUNTIES. MODELS HAVE A
GOOD AMOUNT OF QPF FOR MUCH OF THE DAY...SO KEPT POPS HIGH AND
TEMPS MAY BE SUPPRESSED A BIT BY ONGOING PRECIP SO HAVE MORE
READINGS IN THE UPPER 70S. DO NOT AT THIS POINT THINK THERE WILL
BE MUCH SEVERE DUE TO WEAK DEEP LAYER BULK SHEAR VALUES.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 328 AM CDT WED JUL 15 2015
THURSDAY NIGHT THROUGH FRIDAY NIGHT...MORE WEAK SHORTWAVE TROUGHS
COMING IN AS SOUTHWESTERLY FLOW ALOFT SETS UP OVER THE REGION.
TIMING OF PRECIP IS DIFFICULT TO TELL AT THIS POINT BUT HAVE A
BIT OF A BREAK LATE THURSDAY NIGHT BEFORE THE NEXT SFC TROUGH AXIS
MOVES IN FRIDAY AND SETS OFF MORE CONVECTION. KEEP POPS FAIRLY
HIGH AND TEMPS SHOULD BE NEAR SEASONAL AVERAGES ALTHOUGH SLIGHTLY
MORE MILD ON LOWS DUE TO CLOUDS AND PRECIP.
SATURDAY THROUGH TUESDAY...MODELS IN GOOD AGREEMENT WITH POSITIONING
OF UPPER LEVEL FEATURES. INDICATIONS ARE FOR A TROF DIGGING OVER
THE INTERMOUNTAIN WEST...KEEPING MORE OF A SW FLOW REGIME OVER THE
AREA. VARIOUS IMPULSES ARE EXPECTED TO PROPAGATE THRU THE
FLOW...BRINGING ENOUGH INSTABILITY TO TRIGGER SHOWERS OR STORMS
ACROSS THE AREA EACH DAY. OTHERWISE...TEMPS WILL REMAIN MAINLY ON
THE WARM SIDE...ALTHOUGH A SLIGHT COOLING MAY OCCUR NEAR THE END
OF THE PERIOD AS A WEAK UPPER TROF CROSSES ALONG THE CANADIAN
BORDER.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 653 AM CDT WED JUL 15 2015
MOST OF THE FOG HAS STAYED NORTH OF THE TAF SITES BUT KTVF HAS
BEEN MVFR IN MIST AND KDVL WAS 1SM BUT HAS NOW GONE BACK UP TO
VFR. ANY LINGERING FOG/MIST WILL DISSIPATE IN THE NEXT FEW HOURS
AND WE SHOULD BE VFR THROUGH THE REST OF THE DAY WITH SOME MID AND
HIGH CLOUDS MOVING IN. SHOWERS AND THUNDERSTORMS WILL BEGIN TO
MOVE IN FROM THE WEST LATER THIS AFTERNOON...BUT SO FAR ONLY
INCLUDED VCTS AT KDVL WHICH WILL SEE THE CONVECTION THE SOONEST
AND IS MOST CERTAIN TO BE IMPACTED. THE OTHER TAF SITES ARE LESS
CERTAIN SO WILL LEAVE OUT FOR NOW. HAVE SOME MVFR CIGS AT KBJI
LATE IN THE PERIOD BUT OTHERWISE CIGS EVEN WITH THUNDERSTORMS
SHOULD BE 5000 FT OR MORE. WINDS WILL BE FROM THE SOUTH AT UNDER
10 KTS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...JR
LONG TERM...JR/HOPKINS
AVIATION...JR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
650 AM CDT WED JUL 15 2015
.UPDATE...
ISSUED AT 646 AM CDT WED JUL 15 2015
INCORPORATED RADAR TRENDS THROUGH 1145 UTC...BLENDED TO A TIME
LAGGED ENSEMBLE OF THE 08-10 UTC HRRR ITERATIONS INTO THE
AFTERNOON AND SUPPORTED BY THE 06 UTC GFS WHICH HAVE HAD THE BEST
DEPICTION OF MORNING CONVECTION THUS FAR.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM CDT WED JUL 15 2015
FOCUS IN THE SHORT TERM IS ON CHANCES FOR THUNDERSTORMS WEDNESDAY.
UPPER LEVEL RIDGE REMAINS CENTERED OVER NORTH DAKOTA EARLY THIS
MORNING. THROUGH THE AFTERNOON AND EVENING THE RIDGE WILL PROPAGATE
EAST ALONG WITH A WEAK SURFACE BOUNDARY. AMPLE CAPE AND MARGINAL
BULK SHEAR VALUES WILL MOST LIKELY PRODUCE NUMEROUS THUNDERSTORMS
ACROSS WESTERN AND CENTRAL NORTH DAKOTA THIS AFTERNOON AND TONIGHT.
SHORT RANGE MODELS AS OF LATE HAVE BEEN MORE MISS THAN HIT OVER THE
LAST WEEK OR SO...HOWEVER THE PREVIOUS FEW HRRR MODEL RUNS HAVE BEEN
FAIRLY CONSISTENT WITH NUMEROUS STORMS SETTING UP FROM THE TURTLE
MOUNTAINS INTO SOUTHWESTERN NORTH DAKOTA AROUND 18 UTC AND THEN
PROPAGATING EAST. WITH THAT SAID THE HRRR HAS NOT DONE WELL WITH THE
STORMS THAT WILL NOT SEEM TO STOP ACROSS WILLIAMS AND MCKENZIE
COUNTIES EARLY THIS MORNING. THUS HAVE WENT WITH A BLEND BETWEEN THE
HRRR AND LONGER RANGE MODELS FOR TODAY THROUGH TONIGHT.
THE SPC WEDNESDAY OUTLOOK CONTINUES TO SHOW NORTH DAKOTA IN A SLIGHT
RISK FOR SEVERE THUNDERSTORMS...WITH THE MAIN RISK AS LARGE HAIL AND
GUSTY WINDS. AS OF NOW HAVE A MENTION OF SEVERE IN THE GRIDS
STARTING AT 18 UTC AND PERSISTING INTO THE NIGHT. JUDGING BY THE
POTENTIALLY STRONG STORMS ALREADY IN PLACE IN THE NORTHWEST IT IS
CERTAINLY POSSIBLE TO SEE SEVERE THUNDERSTORMS POP UP EARLY THIS
AFTERNOON.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 316 AM CDT WED JUL 15 2015
AN ACTIVE WEATHER PATTERN CONTINUES TO HIGHLIGHT THE EXTENDED
FORECAST.
THE 00 UTC GLOBAL DETERMINISTIC AND ENSEMBLE SUITES ARE IN
AGREEMENT ON QUASI-ZONAL FLOW ALOFT ACROSS THE NORTHERN PLAINS
THURSDAY AND FRIDAY TRANSITIONING TO SOUTHWEST THIS WEEKEND AS A
POSITIVELY TILTED NORTHERN CONUS AND CANADIAN ROCKIES TROUGH
MODESTLY AMPLIFIES BEFORE PROPAGATING DOWNSTREAM OF THE REGION
INTO EARLY NEXT WEEK. AS A RESULT...DAILY CHANCES FOR
THUNDERSTORMS ARE FORECAST TO CONTINUE THURSDAY THROUGH AT LEAST
SATURDAY...BEFORE A POTENTIAL DECREASE IN STORM ACTIVITY NEXT
WEEK. WHILE THE SEVERE THREAT IS NON-ZERO THURSDAY AND MORE SO ON
FRIDAY AHEAD OF THE SURFACE COLD FRONT...UNCERTAINTY IS TOO HIGH
AT THIS TIME TO ADD A SEVERE MENTION TO THE GRIDS. THIS IS IN LINE
WITH THE SPC OUTLOOK SUITE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 646 AM CDT WED JUL 15 2015
THUNDERSTORMS WILL BE SPREAD ACROSS NORTH DAKOTA THROUGHOUT THE 12Z
TAF PERIOD. AT THIS TIME SITES KDIK...KBIS...AND KMOT HAVE THE
GREATEST CHANCE OF BEING IMPACTED THIS MORNING AND
AFTERNOON...WITH LESSER CHANCES FOR KISN AND KJMS.UNLESS IMPACTED
BY A THUNDERSTORM VFR CONDITIONS ARE EXPECTED FOR THE 12Z TAF
CYCLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...MM
LONG TERM...AYD
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1021 AM EDT WED JUL 15 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE AREA TODAY. FOLLOWING THE
FRONT...SURFACE HIGH PRESSURE WILL DRY OUT THE REGION AS AN UPPER
LEVEL RIDGE BUILDS IN FROM THE WEST...BRINGING WITH IT A RETURN
TO ABOVE NORMAL TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT 1015 AM EDT...NO BIG CHANGES TO THE GOING FORECAST FOR TODAY.
TROUGH/WEAK FRONT ANALYZED FROM CENTRAL NC THROUGH THE UPSTATE INTO
NE GA AT 14Z. 12Z NAM SETTLES THE BOUNDARY SLOWLY SOUTHWARD INTO THE
SC MIDLANDS BY LATE AFTERNOON. THE NAM AND HRRR SHOW ISOLATED
CONVECTION FIRING OVER THE SOUTHERN UPSTATE EARLY THIS AFTERNOON SO
WILL CONTINUE THE ISOLATED POPS THERE. ALSO...THE MODELS SHOW
ISOLATED UPSLOPE SHOWERS ALONG THE TN LINE SO ISOALTED POPS LOOK
GOOD THERE. UPDATED TEMPS/DEWPOINTS WITH LATEST CONSHORT DATA WHICH
BUMPED MAX TEMPS UPWARD A DEGREE OR SO.
630 AM UPDATE...NO MAJOR CHANGES MADE TO THE GRIDS. POPS WERE
TEMPERED DOWN SRN ZONES AS LAST OF VORT PRECIP PUSHES SOUTH. TEMPS
AND TD/S REQUIRED ONLY MINOR TWEAKS WITH SFC WINDS PROVIDING MODEST
MIXING.
AS OF 255 AM EDT WEDNESDAY...AN UPPER LEVEL TROF WILL CONTINUE TO
SWING EAST THROUGH THE DAY WITH THE AXIS PASSING EAST OF THE CWFA BY
16Z/17Z. HEIGHTS WILL BEGIN TO RISE FAIRLY QUICKLY THROUGH THE
AFTERNOON WITH A STRONG H5 HIGH OVER TX NUDGING EAST. LOW LEVEL
MOISTURE SOURCES WILL BE LIMITED...WITH THE BEST POOLING ACROSS THE
MTN SPINE AIDED BY MECH LIFT AND SOME LINGERING MOISTURE SOUTH ALONG
A WEAKENING THETA/E BNDRY FROM CURRENT PRECIP SHIELD ADVANCING
SOUTH. THERE SHOULD BE ENUF LIFT ACROSS THE FAR WRN MTNS FOR
ISOL/SCT -SHRA AND PERHAPS A COUPLE TSTMS. THE SAME GOES FOR THE SRN
ZONES WHERE H5 VORT ENERGY WILL INTERACT WITH THE BNDRY AND PRODUCE
SHORT-LIVED WEAK CONVECTION BEFORE A SUBS INVERSION LIMITS CLOUDS
TO FAIR WX CU MOST LOCALES. WITH DEEP NW/LY FLOW...GOOD MIXING AND
DOWNSLOPE HEATING WILL LOWER SFC TD/S THROUGH THE AFTERNOON.
THUS...THE DAY WILL FEEL A LITTLE DRIER THAN THE PAST FEW DAYS WITH
LOW END GUSTS DEVELOPING BY MID AFTERNOON. THE OVERNIGHT WILL REMAIN
DRY AS THE MLVL FLOW MAINTAINS A N/LY SUBS PATTERN. AT THE SFC... A
RELATIVELY TIGHT PGRAD WILL SLOWLY WEAKEN AS A TROF AXIS SHIFTS
TOWARD THE COAST. SO...WITH SOME WIND AND WEAK SFC-BASED
INVERSIONS...LOWS WILL BE HELD NEAR SEASONAL LEVELS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 230 AM WEDNESDAY...THE 00Z MODEL RUNS SHOW A TREND TOWARD MORE
CONVECTIVE COVERAGE FOR LATE IN THE WEEK...IN SPITE OF THE RETURN OF
THE UPPER RIDGE FROM THE WEST AND THE LACK OF LARGE SCALE FORCING.
THAT BEING SAID...ON THURSDAY AFTERNOON THERE DOES NOT APPEAR TO BE
ANYTHING IN THE MODEL GUIDANCE TO DISCOURAGE DEEP CONVECTION EITHER.
AND...ON A TYPICAL DAY IN THE SUMMERTIME...IT IS DIFFICULT TO KEEP
CONVECTION FROM DEVELOPING ON THE RIDGETOPS GIVEN SUFFICIENT
MOISTURE AND NOTHING THAT ACTS TO PREVENT IT. WILL FOLLOW THE NEW
NAM AND PUT A SMALL PRECIP CHANCE MAINLY OVER THE HIGHEST ELEVATIONS
FOR THE AFTERNOON...AND THEN GET RID OF IT WITH LOSS OF HEATING
THURSDAY EVENING. ON FRIDAY...THE UPPER PATTERN DOES NOT CHANGE
APPRECIABLY WITH THE ANTICYCLONE CENTERED OVER ERN TX/LA...BUT THE
SFC HIGH TO THE NE SEEMS A BIT STRONGER. THE MODELS DEVELOP A WEAK
E/SE FLOW IN THE BOUNDARY LAYER WHICH ADVECTS MOISTURE INTO THE
REGION. THE RESULT IS MORE PRECIP DEVELOPMENT IN THE MODEL. AGAIN...
GIVEN NOTHING TO DISCOURAGE THIS...I EXPECT THERE WILL BE A BIT MORE
COVERAGE THAN PREVIOUSLY EXPECTED...SO PRECIP CHANCES WERE NUDGED
UPWARD A BIT WHICH BRINGS THE PROBABILITY INTO THE CHC RANGE NEAR
THE BLUE RIDGE IN THE AFTERNOON. THE CHANCES FOR ANYTHING BEYOND
GARDEN VARIETY THUNDERSTORMS APPEARS VERY LOW. TEMPS BOTTOM OUT NEAR
NORMAL ON THURSDAY AND THEN BEGIN A CLIMB BACK ABOVE NORMAL STARTING
ON FRIDAY.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 315 AM WEDNESDAY...STILL NO BIG SURPRISES NOTED IN THE LATEST
MEDIUM RANGE GUIDANCE. THE SLOW WESTWARD DRIFT OF THE UPPER
ANTICYCLONE BACK TOWARD THE SRN PLAINS WILL KEEP THE WESTERN
CAROLINAS ON ITS PERIPHERY...AND THUS AWAY FROM ITS SUPPRESSIVE
AFFECTS. THAT SHOULD ALLOW FOR MAINLY DIURNAL SHOWERS AND
THUNDERSTORMS TO DEVELOP EACH DAY GIVEN SUFFICIENT LOW LEVEL
MOISTURE. TEMPS ABOVE NORMAL LOOK LIKE A GOOD BET...BUILDING EACH
DAY TO A PEAK MOST LIKELY ON MONDAY. THE ECMWF SOLUTION SUGGESTS
THAT A SHORT WAVE PASSING TO THE NORTH ON TUESDAY WILL BRING A
WEAKENING COLD FRONT DOWN ACROSS THE AREA THAT WOULD ENHANCE PRECIP
CHANCES AND DROP TEMPS BACK DOWN A BIT. HOWEVER...THE GFS SHOWS THE
UPPER WAVE MUCH FARTHER N AND KEEPS ANY BOUNDARY WELL TO OUR N. WILL
NOT MAKE ANY SIGNIFICANT CHANGES TO THE MEDIUM RANGE AT THIS TIME...
AND THINK EVEN WITHOUT THE FRONT THE COVERAGE OF STORMS WILL
INCREASE A BIT EACH DAY ANYWAY.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...VFR CONDS THROUGH THE TAF PERIOD. THE UPPER TROF AXIS WILL
CROSS EAST OF THE TERMINAL AFT 16Z AND SUPPRESSIVE DYNAMICS WILL
ALLOW ONLY FAIR WX CU THROUGH THE AFTERNOON. NO CIG/VSBY CONCERNS
OVERNIGHT AS WINDS REMAIN UP DUE TO A RELATIVELY TIGHT PGRAD. WINDS
WILL BECOME ALIGNED NW/LY WITH LOW END GUSTS ARND NOON AND THEN N/LY
ARND 00Z AS BROAD SFC TROF PUSHES SOUTHEAST.
ELSEWHERE...VERY SIMILAR TAFS TO KCLT WITH KAVL HAVING THE BEST
POTENTIAL FOR LATE PERIOD VSBY CONCERNS. OTHERWISE...FAIR WX CU WILL
DEVELOP THIS AFTERNOON WITH LOW END GUSTS. GENERALLY A NW/LY DIR ALL
SITES WITH WINDS PERSISTING OVERNIGHT IN A RELATIVELY TIGHT PGRAD.
OUTLOOK...BUILDING UPPER RIDGING WILL PERSIST THROUGH WEEKS END
LEADING TO LOWER PRECIP/RESTRICTION CHANCES. THESE CHANCES WILL
INCREASE OVER THE WEEKEND AS SAID RIDGE RETROGRADES LEADING TO
INCREASING DIURNAL SHRA/TSRA CHANCES AND THUS MORNING FOG/STRATUS AS
WELL.
CONFIDENCE TABLE...
14-20Z 20-02Z 02-08Z 08-12Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL MED 73% HIGH 100% HIGH 100% HIGH 87%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...LG/SBK
SHORT TERM...PM
LONG TERM...PM
AVIATION...SBK
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1021 AM CDT WED JUL 15 2015
.AVIATION/18Z TAFS/...VFR CONDITIONS TODAY INTO MUCH OF THE NIGHT
WITH DRY/STABLE INFLUENCE OF SURFACE HIGH. EXPECT AN INCREASE IN
MID LEVEL CLOUDS AS THE NIGHT WEARS ON WITH LATEST RAP SOUNDINGS
SHOW LOW LEVELS REMAINING QUITE DRY. IMPRESSIVE LLJ TAKES AIM AT
SRN WI FOR THURSDAY WITH DECENT THERMAL/MOIST ADVECTION EXPECTED.
SO HIGH POPS LOOK GOOD. SREF MVFR CIG PROBS SHOW GREATEST
LIKELIHOOD OF MVFR/IFR CONDITIONS ACRS NRN WI ON THURSDAY.
PC
&&
.PREV DISCUSSION... /ISSUED 359 AM CDT WED JUL 15 2015/
TODAY...FORECAST CONFIDENCE IS HIGH.
KEEPING EYE ON LOW CLOUDS MOVING WWD ACROSS LAKE FROM LOWER MI.
APPEARS DECREASING TREND SHOWING UP ON LATEST IR IMAGERY. LOW
CLOUDS NOT INDUCED BY LAKE EFFECT DUE TO MINIMAL DELTA T
DIFFERENCE. CLOUDS ALSO RUNNING INTO DRIER AIR AND SUBSIDENCE OVER
SRN WI. AFTER PATCHY EARLY MORNING CLOUDS IN THE SOUTHEAST...STILL
EXPECTING A VERY PLEASANT DAY UNDER LOTS OF SUNSHINE WITH SOME
PASSING MID TO HIGH CLOUDS LATER THIS MRNG AND AFTN.
NORTHEAST BREEZES WL CONTRIBUTE TO TEMPERATURES REMAINING BELOW
NORMAL TODAY. WARMEST TEMPS IN FAR WEST WHERE KLNR WL MOST LIKELY
CRACK 80.
TONIGHT...FORECAST CONFIDENCE IS HIGH.
A QUIET NIGHT IS EXPECTED MOST AREAS AS SHORT WAVE RIDGING SLIDES
OFF TO THE EAST. DRY AIR AND LIGHT WINDS WILL ALLOW TEMPERATURES
TO FALL RAPIDLY DURING THE EVENING. HOWEVER EXPECT INCREASING MID
TO HIGH CLOUDS LATER IN THE EVENING AND OVERNIGHT AS UPSTREAM LOW
LEVEL JET FOCUSES ON IA/MN. SOUTHWEST WI GETS CLIPPED BY
INCREASING MID LEVEL MOISTURE AND SURGE OF 700MB WARM AIR
ADVECTION. MAY BE JUST ENOUGH MID LEVEL INSTABILITY FOR ISOLD
-SHRA/-TSRA TO DEVELOP LATE TNGT ACROSS FAR WRN CWA WITH BULK OF
PRECIPITATION OCCURRING ON THURSDAY.
SHORT TERM...THURSDAY THROUGH FRIDAY NIGHT...FORECAST CONFIDENCE
IS MEDIUM.
MODELS ARE STILL SHOWING SOME VARIATION IN TIMING AND PLACEMENT OF
FEATURES FOR THURSDAY INTO THURSDAY NIGHT. THE NAM AND CANADIAN
MODELS CONTINUE TO BRING WEAK LOW PRESSURE AND A WARM FRONT
NORTHEASTWARD TOWARD AND ACROSS CENTRAL/NORTHEAST WISCONSIN
DURING THIS PERIOD. THE GFS HAS TRENDED FURTHER NORTHWARD WITH
THESE FEATURES...SIMILAR TO THE NAM/CANADIAN. THE ECMWF CONTINUES
TO BE THE FURTHEST SOUTH WITH THESE FEATURES...NORTHEASTWARD INTO
AND ACROSS SOUTHERN WISCONSIN.
ALL MODELS SHOW A GOOD AMOUNT OF FOCUSED WARM AIR ADVECTION ACROSS
THE AREA THURSDAY INTO THURSDAY NIGHT. THE BEST FRONTOGENESIS
RESPONSE FIELDS REMAIN NORTH/NORTHWEST OF THE AREA...ALONG WITH
THE NOSE OF THE SOUTH SOUTHWESTERLY LOW LEVEL JET. THE MAIN 500 MB
VORTICITY MAXIMUM MOVES THROUGH THE REGION ON THURSDAY...FOCUSING
ON NORTHERN WISCONSIN...EXCEPT THE ECMWF WHICH BRINGS IT THROUGH
SOUTHERN WISCONSIN.
CONTINUED TREND OF BRINGING LIKELY POPS EASTWARD INTO THE AREA
THURSDAY...LINGERING THURSDAY NIGHT. SPC EXPANDED THE MARGINAL
RISK FOR SEVERE STORMS INTO SOUTH CENTRAL WISCONSIN. THERE IS
ENOUGH ELEVATED CAPE LATER THURSDAY INTO THURSDAY NIGHT WITH
MARGINAL DEEP LAYER SHEAR THAT WOULD SUPPORT ISOLATED SEVERE
HAIL. ECMWF HAS MUCH LOWER CAPE VALUES THAN NAM/GFS...SO WENT
BETWEEN THESE FOR CAPE ESTIMATES. HIGH PRECIPITABLE WATER VALUES
AS WELL...SO SOME HEAVY RAINFALL COULD OCCUR.
KEPT CHANCE POPS FOR SHOWERS AND STORMS FRIDAY AND FRIDAY NIGHT
ACROSS THE AREA...AS SURFACE TROUGH/STATIONARY FRONT LINGERS WEST
TO EAST. NAM/ECMWF SHOWING A POSSIBLE MCS TRYING TO MOVE ALONG IT
TOWARD THE AREA FRIDAY NIGHT. THE OTHER MODELS HINT AT QPF ALONG
THE BOUNDARY AT VARIOUS TIMES DURING THIS PERIOD.
AGAIN...WENT BETWEEN HIGH CAPES ON NAM/GFS AND LOWER VALUES ON
ECMWF DURING THIS TIME. DEEP LAYER SHEAR IS MODEST AT BEST...WITH
DECENT PRECIPITABLE WATER VALUES. BEST SHOT AT ANY SEVERE WEATHER
WOULD BE WITH MCS MOVING TOWARD THE AREA LATER FRIDAY NIGHT.
VERY WARM AND HUMID DAY IS EXPECTED FRIDAY...WITH SOUTHWEST WINDS
BRINGING MID TO UPPER 80S ACROSS THE AREA. DEW POINTS SHOULD RISE
INTO THE UPPER 60S TO LOWER 70S AS WELL.
LONG TERM...SATURDAY THROUGH TUESDAY...FORECAST CONFIDENCE IS
MEDIUM.
GFS/ECMWF CONTINUE TO SHOW SOME DIFFERENCES WITH TIMING AND
PLACEMENT OF FEATURES DURING THIS PERIOD. ECMWF TRIES TO BRING
POSSIBLE WEAKENING MCS THROUGH THE AREA SATURDAY MORNING...KEEPING
BOUNDARY NEARBY IN THE AFTERNOON. IT BRINGS A COLD FRONT SOUTHEAST
THROUGH THE AREA SUNDAY WITH DECENT QPF VALUES.
THE GFS HAS THE BOUNDARY FURTHER NORTH...WITH THE COLD FRONT
SLIDING THROUGH MAINLY SUNDAY NIGHT WITH GOOD QPF VALUES.
CONTINUED POPS FOR SHOWERS AND THUNDERSTORMS SATURDAY INTO SUNDAY
NIGHT. MODIFIED CAPES AND MODEST AT BEST DEEP LAYER SHEAR SUGGEST
RELATIVELY LOW SEVERE RISK AT THIS TIME.
VERY WARM AND HUMID CONDITIONS CONTINUE SATURDAY AND SUNDAY...THOUGH
LAKE BREEZE SATURDAY SHOULD COOL THINGS DOWN NEAR THE LAKE. HEAT
INDEX VALUES MAY REACH THE MID 90S DURING THIS TIME INLAND.
THERE MAY BE A LULL IN ANY PRECIPITATION ACTIVITY MONDAY INTO
TUESDAY...WITH COOLER AND DRIER AIR WORKING INTO THE REGION. KEPT
CONSENSUS BLEND OF POPS AND TEMPERATURES FOR THIS PERIOD...BUT MAY
HAVE TO GO DRIER IN LATER FORECASTS IF THIS TREND PERSISTS.
AVIATION/12Z TAFS/...
WEAK LOW LEVEL CONVERGENCE OVER SRN LOWER MI AND LAKE MI CARRYING
SOME STRATUS INTO PORTIONS OF THE WI LAKESHORE EARLY THIS MORNING.
UNFORTUNATELY...PATCHY HIGH CLOUDS CURRENTLY OBSCURING TRENDS OVER
PAST HOUR OR SO...BUT SLIGHT DECREASING TREND NOTED IN LAST
SEVERAL 11-3.9 MICRON IMAGES.
STILL...LATEST IMAGE SHOWS LOW CLOUDS KNOCKING ON DOORSTEP OF
KMKE AND KENW SO INTRODUCED IN LATEST UPDATE. WOULD EXPECT THESE
LOW CLOUDS WOULD THIN RAPIDLY EARLY THIS MORNING AS DRIER AIR AND
BUILDING SUBSIDENCE ERODE LOW CLOUDS. OTRW A VFR PERIOD WITH
THICKENING CLOUDS LATER TONIGHT DUE TO UPSTREAM SURGE OF LOW LEVEL
MOISTURE AND WARM AIR.
MARINE...
WINDS REMAINING GUSTY ACROSS SOUTHERN MARINE ZONES EARLY THIS
MORNING. STATIONARY VESSEL IN RACINE HARBOR REPORTING SUSTAINED NE
WINDS OF 13KTS WHILE FARTHER SOUTH...NE WINDS STILL GUSTING TO
26KTS AT KNSW3. FARTHER NORTH...WEAKENING PRESSURE GRADIENT AND
SURGE OF COLD AIR HAS ALLOWED WINDS TO SUBSIDE TO MOSTLY 10 TO
18KTS.
THIS DIMINISHING TREND WI AFFECT SOUTHERN LAKE MI ZONES EARLY
THIS MORNING...BUT EXPECT WINDS TO REMAIN GUSTY ACROSS SRN LAKE MI
ZONE THROUGH 12Z OR SO. HENCE WL EXTEND SMALL CRAFT ADVY IN LMZ646
BUT CANCEL ELSEWHERE.
BEACHES...
WILL LET BEACH HAZARD STATEMENT EXPIRE AT 09Z. WINDS HAVE
DECREASED TO BELOW 15 KNOTS NORTH OF WIND POINT LIGHT OVERNIGHT
DUE TO WEAKENING PRESSURE GRADIENT AND WEAKENING PUSH OF LOW LEVEL
COLD AIR. WINDS REMAIN GUSTY SOUTH OF WIND POINT ACROSS RACINE AND
KENOSHA BEACHES AS WAVE HEIGHTS STILL IN THE 3 TO 5 FT RANGE.
HOWEVER EXPECT WINDS AND WAVES TO SUBSIDE THROUGH 8 AM SO DO NOT
SEE THE NEED TO EXTEND BEACH HAZARD STATEMENT AT THIS TIME. MOST
SWIMMERS WOULD BE HEADING TO THE BEACH LATER THIS MORNING AND AFTN
WHEN WINDS AND WAVES WILL BE SIGNIFICANTLY LOWER.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...MBK
THURSDAY THROUGH TUESDAY...WOOD
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
123 PM EDT WED JUL 15 2015
.PREV DISCUSSION.../ISSUED 330 AM EDT WED JUL 15 2015/
SHORT TERM /TODAY THROUGH THURSDAY/...
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A WEAKENING COMPLEX WILL
GRAZE NORTHERN GA EARLY THIS MORNING. SATELLITE TRENDS SHOW A
GENERAL WARMING OF TOPS AND A DECREASE IN LIGHTNING. ATMOS FOR THE
NORTHERN HALF OF THE CWFA WAS WORKED OVER PRETTY WELL LAST EVENING
WHEN A STRONGER THUNDERSTORM COMPLEX MOVED ACROSS THE AREA. A FEW
RUMBLES OF THUNDER ARE POSSIBLE THIS MORNING ACROSS THE NORTH...BUT
SEVERE WEATHER IS NOT ANTICIPATED.
A WEAK FRONT/TROUGH WILL MOVE SOUTH ACROSS THE CWFA TODAY. THIS
SURFACE FEATURE IN ADDITION TO A SHORTWAVE TROUGH WILL TEND TO FOCUS
CONVECTION TODAY. IN ADDITION...ANY OUTFLOW BOUNDARY THAT THE
CONVECTION CURRENTLY TO THE NORTH LAYS OUT...MAY PROVIDE ENOUGH
SURFACE CONVERGENCE FOR CONVECTION. HI-RES MODELS...ESPECIALLY THE
WRF...HAVE PERFORMED RATHER DECENTLY OVER THE LAST FEW DAYS. BOTH
THE HRRR AND THE WRF ARE PROGGING THE BULK OF ANY ACTIVITY TODAY
ACROSS THE SOUTHERN THIRD OF THE CWFA.
THE ATMOS DOWN SOUTH HASN`T BEEN WORKED OVER AS MUCH AS FURTHER
NORTH...AND DEEP MOISTURE STILL RESIDES DOWN THERE. SURFACE
INSTABILITY WILL DEFINITELY BE PRESENT. SURFACE CONVERGENCE PROVIDED
BY THE FRONT/TROUGH...OUTFLOW BOUNDARY AND/OR SEABREEZE SHOULD
PROVIDE AMPLE LIFT TO GET THINGS STARTED. IN ADDITION...MID LEVEL
DYNAMICS WILL ALSO BE IN PLAY AS A SHORTWAVE ROUNDS THE BASE OF THE
EASTERN TROUGH. INVERTED V ON THE FORECAST SOUNDINGS SHOW THE
PRIMARY MODE OF SEVERE WEATHER SHOULD BE DAMAGING WIND GUSTS.
HOWEVER...A FEW HAIL REPORTS CANNOT BE RULED OUT AS THE SHORTWAVE
WILL SERVE TO STEEPEN LAPSE RATES.
OLD FRONT/TROUGH WILL REMAIN SITUATED ACROSS SOUTHERN GA THROUGH
TOMORROW. HOWEVER...500MB HIGH PRESSURE WILL BEGIN TO BUILD BACK
EASTWARD. THE UPPER HIGH MAY LIMIT CONVECTIVE DEVELOPMENT...BUT THE
SURFACE FEATURE MAY PROVIDE JUST ENOUGH FOCUS FOR CONVECTIVE
ACTIVITY ACROSS THE SOUTH.
HEAT INDICES ACROSS EAST CENTRAL GEORGIA WILL HAVE THE POTENTIAL TO
REACH NEAR 105 DEGREES AGAIN TODAY. HAVE GONE AHEAD AND ISSUED
ANOTHER HEAT ADVISORY FOR THE REGION.
NLISTEMAA
LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THE UPPER RIDGE HAS NOSED BACK OVER THE AREA TO START THE LONG TERM.
A SURFACE TROUGH OR DISSIPATING STATIONARY FRONT ACROSS CENTRAL GA
WILL CONTINUE SMALL CHANCES FOR SHOWERS AND THUNDERSTORMS THURSDAY
NIGHT.
OTHERWISE THE UPPER RIDGE CONTINUES OVER THE AREA THROUGH SUNDAY
AND BEGINS TO WEAKEN MONDAY AND EVEN MORE SO ON TUESDAY.
THIS WILL ALLOW FOR MAINLY DIURNAL AFTERNOON AND EVENING SHOWERS
AND THUNDERSTORMS FROM THE AFTERNOON HOT TEMPERATURES AND HUMIDITY.
TEMPERATURES FOR THE MOST PART WILL BE A COUPLE TO AS MUCH AS 5-6
DEGREES ABOVE NORMAL DURING THE LONG TERM PERIOD.
BDL
&&
.AVIATION...
18Z UPDATE...
VFR THROUGH THE FORECAST. CU FIELD THIS AFTERNOON OF 3500 TO 5000
FT. THIS WILL DISSIPATE AROUND SUNSET. A FEW015 TOMORROW MORNING
WITH INITIAL LIFTING BUT SHOULD NOT BECOME A CIG. CONVECTION
SHOULD BE CONFINED TO MCN/CSG BUT BY 00Z THU THE CONVECTION WILL
BE SOUTH OF CSG/MCN. WINDS REMAINING WEST TO NORTHWEST WITH A FEW
GUSTS THIS AFTERNOON...BECOMING LIGHT NORTHWEST TONIGHT AND
THURSDAY MORNING.
//ATL CONFIDENCE...18Z UPDATE...
HIGH ON ALL ELEMENTS.
17
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 94 72 92 72 / 20 20 10 10
ATLANTA 91 74 92 74 / 20 20 10 10
BLAIRSVILLE 85 62 85 65 / 20 20 20 10
CARTERSVILLE 91 68 91 69 / 20 20 10 10
COLUMBUS 95 76 95 75 / 40 40 30 20
GAINESVILLE 90 71 89 72 / 20 20 10 10
MACON 96 73 96 73 / 40 40 30 20
ROME 92 69 92 69 / 20 20 10 10
PEACHTREE CITY 92 71 92 71 / 30 30 10 10
VIDALIA 96 75 95 75 / 50 40 40 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR THE FOLLOWING
ZONES: BLECKLEY...DODGE...EMANUEL...JEFFERSON...JOHNSON...
LAURENS...MONTGOMERY...PULASKI...TELFAIR...TOOMBS...TREUTLEN...
TWIGGS...WASHINGTON...WHEELER...WILCOX...WILKINSON.
&&
$$
SHORT TERM...17
LONG TERM....01
AVIATION...17
AREA FORECAST DISCUSSION
NWS DES MOINES IA
328 PM CDT WED JUL 15 2015
.SHORT TERM /TONIGHT/...
ISSUED AT 327 PM CDT WED JUL 15 2015
CHALLENGING FORECAST FOR THE OVERNIGHT. TWO DISTINCT VORTICITY
MAXIMUM OVER THE REGION THIS AFTERNOON...ONE ASSOCIATED WITH THE
H500 SHORTWAVE IN EASTERN NEBRASKA AND THE OTHER FARTHER SOUTH OVER
NORTHWEST MISSOURI. TO COMPLICATE MATTERS A WEAK SFC LOW AND TROUGH
EXTEND FROM SOUTH CENTRAL NEBRASKA TO NORTHEAST IOWA. SYNOPTIC SCALE
MODELS HAVE BEEN FAIRLY CONSISTENT WITH FORCING INCREASING OVER
WEST CENTRAL TO NORTHEAST IOWA BY 12Z...FOCUSING AN EXPANDING AREA
OF MODERATE TO HEAVY RAINFALL IN THIS LOCATION. OF THESE THE EURO
HAS TRENDED SLIGHTLY FARTHER SOUTH WITH WIDESPREAD COVERAGE OF
RAINFALL. THE HRRR IS CONCENTRATING THE LIONS SHARE OF FORCING
OVER SOUTHERN IOWA TONIGHT...RIGHT ON THE NORTHERN EDGE OF MORE
ROBUST INSTABILITY. WITH BOTH VORT MAXES PLAYING A ROLE IN THE
OVERNIGHT FORECAST...IT LOOKS LIKE AN AREA OF MODERATE TO
POTENTIALLY LOCALLY HEAVY RAINFALL WILL OCCUR FROM WEST CENTRAL
TOWARD NORTHEAST WITH A SECONDARY MAXIMUM OVER THE SOUTHERN
SECTIONS SOUTH OF INTERSTATE 80...EAST TO ABOUT I35 AGAIN THIS
AREA COULD SEE LOCALLY HEAVY RAINFALL. WITH THE MAXIMUM
INSTABILITY SOUTH OF IOWA NOW...THE SOUTHERN AREAS SHOULD FILL IN
LATER THIS EVENING AS THE H850 LOW LEVEL JET OF 30 TO 40KT
INCREASES AFTER 03-04Z. PRECIPITABLE WATER VALUES ARE EXPECTED TO
INCREASE TO NEARLY 2 INCHES BY 06Z OVER MUCH OF THE REGION WITH
WARM CLOUD DEPTHS IN EXCESS OF 13KFT...PROMOTING EFFICIENT
RAINFALL PROCESSES. THE DAY1 CONVECTIVE OUTLOOK HAS BEEN INCREASED
FOR A SLIGHT RISK ACROSS THE SOUTH WITH SOME POTENTIAL FOR SEVERE
STORMS SOUTHWEST/WEST THROUGH THE EVENING HOURS...THOUGH MAIN
CONCERNS REMAIN POTENTIAL FOR LOCALLY HEAVY RAINFALL. WITH FLASH
FLOOD GUIDANCE BETWEEN 2 TO 3 INCHES PER 3 HOURS OVER THE
WEST/SOUTHWEST...WE MAY SEE SOME LOCALIZED FLASH FLOODING OVER
PORTIONS OF WESTERN/SOUTHWEST SECTIONS TONIGHT. FOR NOW HAVE HELD
OFF ON HEADLINES DUE TO SOME UNCERTAINTIES IN THE DEVELOPMENT OF
CONVECTION AND EVENTUAL EVOLUTION. LOWS WILL HOLD IN THE UPPER 60S
TO LOWER 70S WITH UNCOMFORTABLE DEW POINTS NEAR THE SAME VALUES.
WINDS WILL INCREASE A BIT FROM THE SOUTH DURING THE OVERNIGHT
HOURS.
.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
ISSUED AT 327 PM CDT WED JUL 15 2015
THE STORM SYSTEM SET TO AFFECT THE AREA TONIGHT...AS DISCUSSED AT
LENGTH IN THE SHORT TERM SECTION ABOVE...WILL CLEAR OUT TO THE
EAST ON THURSDAY MORNING. LARGE SCALE MODELS ARE A BIT SLOWER WITH
THIS CLEARING...WHILE THE HIGH RESOLUTION MODELS ARE SOMEWHAT
FASTER WHICH IS MORE CONSISTENT WITH CLIMATOLOGY IN THIS SYNOPTIC
SET UP. FURTHERMORE THERE ARE INDICATIONS THAT A WEAK UPPER
IMPULSE MOVING IN BEHIND THE INITIAL WAVE...COMBINED WITH
AFTERNOON DESTABILIZATION AND LINGERING OUTFLOW BOUNDARIES FROM
MORNING CONVECTION...MAY LEAD TO SOME ISOLATED STORM REDEVELOPMENT
LATE IN THE DAY OR THURSDAY EVENING. AS A RESULT OF ALL OF THESE
FACTORS...MAINTAINED A FAIRLY RAPID CLEARING OF HIGHER POPS TO THE
EAST ON THURSDAY MORNING BUT HELD SOME LOWER POPS BACK IN THE
SOUTH AND WEST AT TIMES MAINLY THURSDAY EVENING. ALSO MAINTAINED
SOME FOG MENTION LATE THURSDAY NIGHT/EARLY FRIDAY MORNING GIVEN
THE LIGHT AND VARIABLE WINDS EXPECTED ALONG WITH CLEARING SKIES
AND WET GROUND/HIGH DEWPOINTS.
BY FRIDAY SOUTHERLY SURFACE WINDS WILL RETURN TO THE AREA...WITH
500 MB FLOW TURNING TO WEST SOUTHWEST AND A FRONTAL BOUNDARY
DEVELOPING WELL TO OUR NORTHWEST ACROSS SOUTH DAKOTA AND
MINNESOTA. THIS BOUNDARY WILL LIKELY PROVIDE THE IMPETUS FOR
THUNDERSTORM DEVELOPMENT FRIDAY EVENING AND FRIDAY NIGHT...BUT
THIS SHOULD LARGELY STAY NORTH OF OUR FORECAST AREA. ALSO...THERE
MAY BE SOME PEAK HEATING STORM DEVELOPMENT ACROSS OUR AREA IN THE
WARM SECTOR FRIDAY AFTERNOON AND EVENING...HOWEVER A GENERAL LACK
OF FORCING OR FOCUS MECHANISM PROHIBIT INTRODUCING POPS AT THIS
TIME. FRIDAY WILL ALSO SEE A RETURN OF MORE HEAT AND HUMIDITY...AS
LOW LEVEL WARM AIR AND MOISTURE ADVECTION BENEATH INCREASING
TEMPERATURES ALOFT PROMOTE HIGH TEMPERATURES IN THE LOWER 90S WITH
HEAT INDEX VALUES APPROACHING 100 LATE IN THE DAY. SATURDAY WILL
BE QUITE SIMILAR...WITH HOT AND HUMID CONDITIONS AND A LOW CHANCE
OF WARM SECTOR THUNDERSTORMS THAT WOULD BE ISOLATED IF THEY
DEVELOP.
FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT THE FORECAST WILL BE
DOMINATED BY THE APPROACH AND PASSAGE OF THE AFOREMENTIONED
FRONTAL BOUNDARY FROM NORTHWEST TO SOUTHEAST. A WARM AND VERY
UNSTABLE AIRMASS AHEAD OF THE FRONT WILL PROMOTE VIGOROUS
THUNDERSTORM DEVELOPMENT PARTICULARLY SUNDAY AFTERNOON AND
EVENING...WITH BULK SHEAR FORECASTS CERTAINLY SUPPORTING SOME
SEVERE WEATHER THREAT WITH THE ADVANCING FRONTAL ZONE.
HOWEVER...SIGNIFICANT DIFFERENCES IN THE TIMING OF THIS PASSAGE
REMAIN AMONG THE VARIOUS MODELS. THE ECMWF HAS BEEN STICKING TO
ITS GUNS FOR THE LAST THREE RUNS WITH A MUCH FASTER PASSAGE AND
THE GFS HAS BEEN SLOWLY COMING AROUND IN THAT DIRECTION. IF THIS
OCCURS...IT WOULD RESULT IN SOMEWHAT COOLER HIGHS SUNDAY AND SHIFT
ANY SEVERE WEATHER POTENTIAL MORE ACROSS SOUTHERN AND EASTERN IOWA
RATHER THAN FURTHER NORTHWEST. FOR NOW THE UNCERTAINTY IN THIS
EVOLUTION RESULTS IN SEVERAL PERIODS OF CHANCE POPS WITH NO
LIKELIES INTRODUCED AS OF YET...BUT ONCE THE DETAILS OF TIMING
BECOME CLEARER THEN HIGHER POPS WILL NEED TO BE INTRODUCED IN ONE
OR MORE OF THE PERIODS FROM SATURDAY NIGHT THROUGH SUNDAY
NIGHT...AND SUNDAY HIGH TEMPERATURES MAY NEED TO BE ADJUSTED
FURTHER AS WELL.
AS ROUGHLY ZONAL STEERING FLOW PERSISTS INTO EARLY NEXT WEEK
TEMPERATURES BEHIND THE SUNDAY COOL FRONT WILL SLOWLY MODERATE AND
LOW RAIN CHANCES WILL PERSIST. GIVEN THE DIFFICULTY IN PREDICTING
ANY SUBTLE IMPULSES TYPICALLY MOVING THROUGH SUCH FLOW AT THIS
TIME RANGE...HAVE MAINTAINED ONLY LOW POPS AT TIMES IN THE LATTER
PART OF THE EXTENDED FORECAST PERIOD.
&&
.AVIATION...15/18Z
ISSUED AT 1247 PM CDT WED JUL 15 2015
REMNANT MODERATE SHOWERS MOVING ACROSS THE AREA FROM THE SOUTHWEST
AS MCV CONTINUES TO GENERATE MORE SHOWERS WEST. ACROSS THE EAST
CIGS REMAIN MVFR NEAR KALO AND KOTM...WITH SOME IMPROVEMENT AFT
19Z. MCV EXPECTED TO EXPAND PRECIP SHIELD TONIGHT WITH IFR/MVFR
CIGS AND POTENTIAL FOR +SHRA AND TSRA THROUGH 13Z ACROSS THE
REGION. FAVORED AREAS REMAIN NORTH SITES...HOWEVER MESO MODELS
OFFERING DIFFERING SOLNS EVEN NOW WHICH MAY RESULT IN SOME
SOUTHWARD SHIFT OF HEAVY RAIN/LOWER CONDITIONS AXIS IN THE NEXT
TAF PACKAGE./REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...REV
LONG TERM...LEE
AVIATION...REV
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
250 PM EDT WED JUL 15 2015
.UPDATE...
ISSUED AT 225 PM EDT WED JUL 15 2015
DID A QUICK UPDATE TO FINE TUNE TEMPS AND DEWPOINTS THROUGH THE
REST OF THE AFTERNOON. THESE HAVE BEEN SENT TO THE NDFD AND WEB
SERVERS.
UPDATE ISSUED AT 1025 AM EDT WED JUL 15 2015
14Z SFC ANALYSIS SHOWS HIGH PRESSURE BUILDING INTO EASTERN
KENTUCKY AND PROVIDING A BREATHER FROM THE ACTIVE WEATHER OF THE
PAST SEVERAL DAYS. ACCOMPANYING THE HIGH IS A BAND OF LOWER
STRATUS SINKING SOUTH THROUGH THE CWA. THANKS TO THIS MANY
LOCATIONS IN THE NORTHERN PARTS OF EAST KENTUCKY ARE STILL IN THE
UPPER 60S WHILE SPOTS TO THE SOUTH HAVE CLIMBED INTO THE LOWER AND
MIDDLE 70S. NORTHWEST TO NORTH WINDS OF 5 TO 10 KTS ARE BRINGING
IN DRIER AIR...AS WELL...WITH DEWPOINTS RUNNING ABOUT 10 DEGREES
LOWER THAN THOSE OF YESTERDAY. ON RADAR...THERE HAVE BEEN A FEW
VERY LIGHT RETURNS ACROSS THE FAR EAST OVER THE PAST COUPLE OF
HOURS...BUT IT IS DOUBTFUL THAT ANY MORE THAN A FEW SPRINKLES
MAKING IT TO THE GROUND. THE REST OF THE DAY WILL BE PARTLY CLOUDY
AND DRIER/COOLER THAN YESTERDAY THANKS TO THE CLOUDS AND NORTHERLY
SFC WINDS. THE HRRR AND...TO A CERTAIN DEGREE...THE NAM12 ARE
HINTING THAT SOME VERY LIGHT AND BRIEF SHOWERS WILL BE POSSIBLE
THROUGH THE AREA. AS THIS WILL BE INSIGNIFICANT...FOR NOW...WILL
KEEP THE POPS SUB 14 PERCENT AND ANY PCPN OUT OF THE WX
GRIDS/ZONES. HAVE UPDATED THE FORECAST MAINLY TO REMOVE THE FOG
MENTION AND ALSO TO TWEAK TEMPS/DEWPOINTS PER THE LATEST OBS AND
TRENDS. THE GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS IN
ADDITION TO A FRESHENED SET OF ZONES.
UPDATE ISSUED AT 721 AM EDT WED JUL 15 2015
9Z SURFACE ANALYSIS HAD THE FRONT MOSTLY THROUGH THE ARE AND
SHOULD MAKE IT THE REST OF THE WAY BY AROUND 12Z. A FEW STRATUS
CLOUDS ARE MOVING THROUGH AND ARE STILL EXPECTED TO LIFT OUT BY
THE AFTERNOON. NO MAJOR CHANGES NEEDED THIS UPDATE WITH MINOR
ADJUSTMENTS TO ACCOUNT FOR LATEST OBS AND TRENDS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 327 AM EDT WED JUL 15 2015
WATER VAPOR SHOWS A POTENT UPPER LOW FOR THIS TIME OF YEAR SPINNING
EAST ACROSS THE MID ATLANTIC THIS MORNING. WHILE THERE IS IS BIT
MORE IN THE WAY OF MID/UPPER LEVEL DRYING ACROSS THE OHIO VALLEY.
THEREFORE LOOKING AT REGIONAL RADAR DATA THIS MORNING SHOWS MUCH
OF THE SHOWER AND THUNDERSTORM ACTION SEEN YESTERDAY EVENING HAS
MOVED INTO THE SOUTHERN TENNESSEE VALLEY REGION THIS MORNING. THE
FRONT IS LAGGING BEHIND THIS AND THAT COUPLED WITH SOME DIVERGENCE
ALOFT GENERATED SOME ISOLATED SHOWERS IN THE FAR EAST AND
SOUTHEAST...HOWEVER THIS WILL CONTINUE SOUTHEAST OUT OF THE AREA
THIS MORNING. GIVEN THAT ACTIVITY HAS MOVED OUT OF THE REGION AND
NOT ADDITIONAL RAINFALL IS EXPECTED IN THE SHORT TERM PERIOD WILL
LET THE FLASH FLOOD WATCH EXPIRE WITH PACKAGE ISSUANCE. SOME
STRATUS IS INDICATED BY IR SAT AND UPSTREAM OBS MOVING SOUTH OUT
OF OHIO THIS MORNING AND THIS COULD SWEEP ACROSS THE REGION. ALSO
SHOULD NOTE MODEL SOUNDINGS AND TIME HEIGHTS WANT TO KEEP A BIT OF
LOWER MOISTURE IN PLACE..SO TRY TO REFLECT THIS THROUGH THE MID
MORNING TIME FRAME IN THE GRIDS. OTHERWISE DOES LOOK LIKE OVERALL
CLOUDS WILL BE ON THE DECREASE THROUGH THE DAY. THIS WILL BE A
SIGH OF RELIEF AFTER SUCH A ACTIVE WEATHER PATTERN OVER THE PAST
SEVERAL DAYS.
REST OF THE PERIOD STAYS QUIET AS MODELS STAY IN GOOD AGREEMENT
WITH HEIGHT RISES AS UPPER HIGH MEANDERS AROUND NEAR THE ARKLATEX
REGION. AT THE SURFACE A HIGH PRESSURE TRAVERSES THE GREAT LAKES
INTO SOUTHERN NEW ENGLAND. ALL OF THESE ELEMENTS WILL COMBINE TO
BRING NEAR TO BELOW NORMAL TEMPS AND MOSTLY SUNNY SKIES BY
THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 455 AM EDT WED JUL 15 2015
THE MODELS REMAIN IN GOOD AGREEMENT WITH UPPER LEVEL RIDGING
BUILDING INTO THE LOWER AND MIDDLE MISSISSIPPI VALLEY THROUGH THE
FIRST HALF OF THE WEEKEND...BEFORE ANOTHER TROUGH SHIFTS EAST
ACROSS THE NORTHERN CONUS...SUPPRESSING THE RIDGE TO THE SOUTH AND
SOUTHWEST. THERE ARE MORE MODEL DIFFERENCES WITH REGARDS TO THE
STRENGTH OF THE APPROACHING TROUGH...WITH THE GFS ON THE WEAKER
SIDE...WHILE THE ECMWF IS MORE ROBUST. AS SUCH...FOLLOWED THE
BLEND PRETTY CLOSE.
FOR EASTERN KENTUCKY...PLENTY OF HEAT AND HUMIDITY WILL BE ON TAP
FROM FRIDAY THROUGH MONDAY...WITH HIGHS AROUND 90 AND LOWS AROUND
70. HEAT INDICES WILL GENERALLY PEAK IN THE 95 TO 100 DEGREE RANGE
FROM SATURDAY THROUGH MONDAY. TEMPERATURES WILL THEN COOL OFF A
BIT ON TUESDAY...WITH HIGHS DROPPING BACK INTO THE MID AND UPPER
80S. ALONG WITH THE HEAT AND HUMIDITY...WILL BE THE RETURN OF
SHOWER AND THUNDERSTORM CHANCES...GENERALLY PEAKING DURING THE
AFTERNOON AND EARLY EVENING HOURS. THE BEST POPS WILL ARRIVE EARLY
NEXT WEEK AS A COLD FRONT SHIFTS SOUTHEAST ACROSS THE AREA. STUCK
FAIRLY CLOSE TO BLENDED GUIDANCE...ALTHOUGH DID UNDERCUT POPS A
BIT MORE DURING PERIODS OF WEAKER FORCING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 250 PM EDT WED JUL 15 2015
THE CIGS ARE NOW COMING UP OUT OF THE MVFR REACHING VFR ACROSS
THE AREA. LOOK FOR THE CLOUDS TO BREAKUP AND SCATTER OUT LATER
THIS EVENING. THIS WILL LIKELY LEAD TO THE DEVELOPMENT OF FOG
OVERNIGHT AT ALL SITES. EXPECT THE THICKEST FOG WITH THE WORSE
CONDITIONS...DOWN TO VLIFR...IN THE LOWER TAF SITES OF SME AND
LOZ. THE CONDITIONS WILL THEN IMPROVE DURING THE MORNING THURSDAY
WITH VFR TO FOLLOW. WINDS WILL BE RELATIVELY LIGHT THROUGH THE
PERIOD AT 5 TO 10 KTS OR LESS GENERALLY FROM THE NORTH.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...DJ
LONG TERM...GEOGERIAN
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
224 PM CDT WED JUL 15 2015
.UPDATE...TEMPERATURES AND DEW POINTS NOT AS HIGH AS PREVIOUSLY
FCST FOR THIS AFTERNOON. RUC LOOKS TO BE TRACKING TOO HIGH. ZONES
ALREADY UPDATED. GRIDS TO FOLLOW.
SWEENEY
&&
.PREV DISCUSSION... /ISSUED 1236 PM CDT WED JUL 15 2015/
DISCUSSION...
FOR 18Z TAF ISSUANCE.
AVIATION...
NOT MUCH MORE THAN A PERSISTENCE FORECAST THIS AFTERNOON AS
RIDGING ALOFT IS PROGGED TO STAY IN CONTROL AND KEEP MUCH OF THE
ATMOSPHERE DRY THROUGH THE PERIOD. COULD BE SOME MVFR CEILINGS
LATE MAINLY AT KBPT...OTHERWISE VFR WILL BE THE RULE ALONG WITH
MAINLY LIGHT WINDS.
25
PREV DISCUSSION... /ISSUED 1007 AM CDT WED JUL 15 2015/
UPDATE...LATEST RUC CONFIRMING SUBSIDENCE EFFECTS FROM DYNAMIC
HIGH PRESSURE FROM THE UPPER LEVELS. ADJUSTED TEMPS UP FOR
INTERIOR AREAS FROM GUIDANCE. CLOSER TO THE COAST, ONLY A TWEAK
HIGHER. COMBINED WITH UPDATED DEW POINTS, HEAT INDICES APPROACH
BUT DO NOT REACH ADVISORY LEVELS BUT WILL MONITOR THIS. REMAINDER
OF THE FORECAST ON TRACK WITH POSSIBLILITY OF ISOLD SHOWERS FOR
ACADIANA THIS AFTERNOON...NOT ENOUGH TO MENTION IN THE ZONES.
SWEENEY
PREV DISCUSSION... /ISSUED 546 AM CDT WED JUL 15 2015/
AVIATION...STRONG HIGH PRESSURE AT THE SURFACE AND ALOFT WILL
MAINTAIN A DRY WEATHER PATTERN ALONG WITH VFR. WINDS WILL REMAIN
LIGHT AND GENERALLY FROM THE WEST TO SOUTHWEST.
PREV DISCUSSION... /ISSUED 359 AM CDT WED JUL 15 2015/
DISCUSSION...
FAIRLY TYPICAL SUMMER NIGHT ACROSS THE FORECAST AREA WITH
TEMPERATURES IN THE MID 70S...AND A FEW SMALL NOCTURNAL SHOWERS
TRYING TO FORM OFF THE LOWER ACADIANA COAST.
LATEST WATER VAPOR IMAGERY STILL INDICATES AN UPPER LEVEL RIDGE
HANGING IN OVER THE REGION WITH DRY AND SUBSIDENT AIR IN THE MID
AND UPPER LEVELS. THIS IS CONFIRMED BY THE 15/00Z UPPER AIR
SOUNDING FROM KLCH WITH A BELOW NORM PWAT READING OF 1.3 INCHES
AND MEAN RH AROUND 40 PERCENT...WITH THE MID LEVEL RH AT 27
PERCENT. RECENT GPS-MET INTEGRATED PWAT VALUES AROUND THE AREA
SHOW NOT MUCH CHANGE WITH READINGS STILL FROM ROUGHLY 1.25 INCHES
TO 1.4 INCHES.
MOISTURE VALUES ARE PROGGED TO STAY ROUGHLY THE SAME FOR THE NEXT
FEW DAYS AS THE MID/UPPER LEVEL RIDGE CONTINUES TO HOLD IN PLACE.
MID LEVEL MOISTURE LOOKS TO REMAIN ON THE LOW SIDE WITH VALUES IN
THE 30 PERCENT RANGE. THIS SHOULD PRECLUDE ANY SIGNIFICANT SHOWER
ACTIVITY...ALTHOUGH ONE OR TWO ISOLATED CELLS MAY FORM IN THE MAX
DAYTIME HEATING OVER THE COASTAL MARSHES WHERE SEA BREEZE
CONVERGENCE AND ATCHAFALAYA BASIN CONVERGENCE OCCURS...BUT
PROBABILITY LOW ENOUGH (BELOW 15 PERCENT) TO MENTION.
WITH SOUTHERLY SURFACE WINDS...LOW LEVEL MOISTURE WILL BE PLENTY
TO HELP BRING ABOUT SUMMERTIME HOT AND MUGGY CONDITIONS. ENOUGH
MIXING HAS BEEN OCCURRING DURING THE AFTERNOON HOURS TO KEEP HEAT
INDEX READINGS JUST IN CHECK...WITH A MAJORITY OF THE REPORTING
SITES SEEING 100F TO 102F WITH ISOLATED SPOTS FROM 103F TO 106F.
PERSISTENCE LOOKS LIKE THE WAY TO GO HERE...SO VALUES WILL BE JUST
BELOW HEAT ADVISORY CRITERIA. WILL MAKE MENTION IN THE HAZARDOUS
WEATHER OUTLOOK OF THE HEAT INDEX READINGS BETWEEN 102F AND 106F
DURING THE AFTERNOON HOURS.
BY THE WEEKEND...PROGS HINTING AT THE MID/UPPER LEVEL RIDGE
SLIGHTLY WEAKENING...WITH THE GFS MORE INCLINED TO BRING SOME MID
LEVEL MOISTURE BACK INTO THE REGION. WITH THIS...WILL INTRODUCE
ONLY SLIGHT POPS FOR SATURDAY AND SUNDAY FOR EASTERN PORTIONS
(MAINLY LOWER ACADIANA.) WITH CHANCES FOR SHOWERS EXPANDING
WESTWARD TO INCLUDE A MAJORITY OF THE FORECAST AREA EARLY TO MID
PART OF NEXT WEEK. STILL POPS ONLY IN THE 20-30 PERCENT RANGE.
RUA
MARINE...
SURFACE HIGH PRESSURE IS CENTERED OVER THE EASTERN GULF OF MEXICO.
THIS HIGH WILL RIDGE ACROSS THE NORTHERN GULF OF MEXICO FOR THE
NEXT SEVERAL DAYS. THEREFORE...NO REAL CHANGE FOR THE COASTAL
WATERS AS FAR AS WINDS AND SEAS GOES...WITH MAINLY LIGHT SOUTHWEST
TO SOUTH WINDS AND LOW SEAS. A FEW MORE SHOWERS AND THUNDERSTORMS
MAY BEGIN TO DEVELOP OVER THE WEEKEND OFF THE LOWER ACADIANA
WATERS...AS AN UPPER LEVEL HIGH SHOWS SIGNS OF WEAKENING.
RUA
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 99 74 96 74 / 0 0 10 10
LCH 94 77 93 77 / 10 0 10 0
LFT 95 77 93 76 / 10 10 10 10
BPT 94 77 92 79 / 10 0 20 0
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
PUBLIC...11
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1236 PM CDT WED JUL 15 2015
.DISCUSSION...
FOR 18Z TAF ISSUANCE.
&&
.AVIATION...
NOT MUCH MORE THAN A PERSISTENCE FORECAST THIS AFTERNOON AS
RIDGING ALOFT IS PROGGED TO STAY IN CONTROL AND KEEP MUCH OF THE
ATMOSPHERE DRY THROUGH THE PERIOD. COULD BE SOME MVFR CEILINGS
LATE MAINLY AT KBPT...OTHERWISE VFR WILL BE THE RULE ALONG WITH
MAINLY LIGHT WINDS.
25
&&
.PREV DISCUSSION... /ISSUED 1007 AM CDT WED JUL 15 2015/
UPDATE...LATEST RUC CONFIRMING SUBSIDENCE EFFECTS FROM DYNAMIC
HIGH PRESSURE FROM THE UPPER LEVELS. ADJUSTED TEMPS UP FOR
INTERIOR AREAS FROM GUIDANCE. CLOSER TO THE COAST, ONLY A TWEAK
HIGHER. COMBINED WITH UPDATED DEW POINTS, HEAT INDICES APPROACH
BUT DO NOT REACH ADVISORY LEVELS BUT WILL MONITOR THIS. REMAINDER
OF THE FORECAST ON TRACK WITH POSSIBLILITY OF ISOLD SHOWERS FOR
ACADIANA THIS AFTERNOON...NOT ENOUGH TO MENTION IN THE ZONES.
SWEENEY
PREV DISCUSSION... /ISSUED 546 AM CDT WED JUL 15 2015/
AVIATION...STRONG HIGH PRESSURE AT THE SURFACE AND ALOFT WILL
MAINTAIN A DRY WEATHER PATTERN ALONG WITH VFR. WINDS WILL REMAIN
LIGHT AND GENERALLY FROM THE WEST TO SOUTHWEST.
PREV DISCUSSION... /ISSUED 359 AM CDT WED JUL 15 2015/
DISCUSSION...
FAIRLY TYPICAL SUMMER NIGHT ACROSS THE FORECAST AREA WITH
TEMPERATURES IN THE MID 70S...AND A FEW SMALL NOCTURNAL SHOWERS
TRYING TO FORM OFF THE LOWER ACADIANA COAST.
LATEST WATER VAPOR IMAGERY STILL INDICATES AN UPPER LEVEL RIDGE
HANGING IN OVER THE REGION WITH DRY AND SUBSIDENT AIR IN THE MID
AND UPPER LEVELS. THIS IS CONFIRMED BY THE 15/00Z UPPER AIR
SOUNDING FROM KLCH WITH A BELOW NORM PWAT READING OF 1.3 INCHES
AND MEAN RH AROUND 40 PERCENT...WITH THE MID LEVEL RH AT 27
PERCENT. RECENT GPS-MET INTEGRATED PWAT VALUES AROUND THE AREA
SHOW NOT MUCH CHANGE WITH READINGS STILL FROM ROUGHLY 1.25 INCHES
TO 1.4 INCHES.
MOISTURE VALUES ARE PROGGED TO STAY ROUGHLY THE SAME FOR THE NEXT
FEW DAYS AS THE MID/UPPER LEVEL RIDGE CONTINUES TO HOLD IN PLACE.
MID LEVEL MOISTURE LOOKS TO REMAIN ON THE LOW SIDE WITH VALUES IN
THE 30 PERCENT RANGE. THIS SHOULD PRECLUDE ANY SIGNIFICANT SHOWER
ACTIVITY...ALTHOUGH ONE OR TWO ISOLATED CELLS MAY FORM IN THE MAX
DAYTIME HEATING OVER THE COASTAL MARSHES WHERE SEA BREEZE
CONVERGENCE AND ATCHAFALAYA BASIN CONVERGENCE OCCURS...BUT
PROBABILITY LOW ENOUGH (BELOW 15 PERCENT) TO MENTION.
WITH SOUTHERLY SURFACE WINDS...LOW LEVEL MOISTURE WILL BE PLENTY
TO HELP BRING ABOUT SUMMERTIME HOT AND MUGGY CONDITIONS. ENOUGH
MIXING HAS BEEN OCCURRING DURING THE AFTERNOON HOURS TO KEEP HEAT
INDEX READINGS JUST IN CHECK...WITH A MAJORITY OF THE REPORTING
SITES SEEING 100F TO 102F WITH ISOLATED SPOTS FROM 103F TO 106F.
PERSISTENCE LOOKS LIKE THE WAY TO GO HERE...SO VALUES WILL BE JUST
BELOW HEAT ADVISORY CRITERIA. WILL MAKE MENTION IN THE HAZARDOUS
WEATHER OUTLOOK OF THE HEAT INDEX READINGS BETWEEN 102F AND 106F
DURING THE AFTERNOON HOURS.
BY THE WEEKEND...PROGS HINTING AT THE MID/UPPER LEVEL RIDGE
SLIGHTLY WEAKENING...WITH THE GFS MORE INCLINED TO BRING SOME MID
LEVEL MOISTURE BACK INTO THE REGION. WITH THIS...WILL INTRODUCE
ONLY SLIGHT POPS FOR SATURDAY AND SUNDAY FOR EASTERN PORTIONS
(MAINLY LOWER ACADIANA.) WITH CHANCES FOR SHOWERS EXPANDING
WESTWARD TO INCLUDE A MAJORITY OF THE FORECAST AREA EARLY TO MID
PART OF NEXT WEEK. STILL POPS ONLY IN THE 20-30 PERCENT RANGE.
RUA
MARINE...
SURFACE HIGH PRESSURE IS CENTERED OVER THE EASTERN GULF OF MEXICO.
THIS HIGH WILL RIDGE ACROSS THE NORTHERN GULF OF MEXICO FOR THE
NEXT SEVERAL DAYS. THEREFORE...NO REAL CHANGE FOR THE COASTAL
WATERS AS FAR AS WINDS AND SEAS GOES...WITH MAINLY LIGHT SOUTHWEST
TO SOUTH WINDS AND LOW SEAS. A FEW MORE SHOWERS AND THUNDERSTORMS
MAY BEGIN TO DEVELOP OVER THE WEEKEND OFF THE LOWER ACADIANA
WATERS...AS AN UPPER LEVEL HIGH SHOWS SIGNS OF WEAKENING.
RUA
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 99 74 95 75 / 0 0 10 0
LCH 94 77 93 78 / 10 0 10 10
LFT 95 77 94 77 / 10 0 10 0
BPT 94 77 94 77 / 10 0 10 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AVIATION...04
AREA FORECAST DISCUSSION
NWS GRAY ME
618 PM EDT WED JUL 15 2015
.SYNOPSIS...
A COLD FRONT WILL PUSH WELL OFF THE COAST THIS EVENING...BRINGING
A MUCH DRIER AIR MASS TO THE REGION. COOLER AIR WILL ALSO FILTER
IN FROM THE NORTH...WITH READINGS FALLING INTO THE 40S AND 50S.
HIGH PRESSURE WILL FOLLOW FOR THURSDAY AND THURSDAY
NIGHT...BRINGING QUIET WEATHER. THE HIGH WILL SHIFT OFFSHORE OVER
THE WEEKEND ALLOWING FOR A WARMER AND MORE MOIST AIRMASS TO MOVE
IN...POSSIBLY ASSOCIATED WITH SHOWERS AND THUNDERSTORMS. THIS
ACTIVITY COULD PERSIST INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
610 PM...MINOR ESTF UPDATE TO REFLECT CURRENT RADAR TRENDS... AND
TO INGEST THE 22Z MESONET INTO FIRST PERIOD GRIDS. SCATTERED
CONVECTION CONTINUES TO FIRE OVER EASTERN ROCKINGHAM COUNTY ALONG
CONVERGENCE ZONE...BUT EXPECT THIS ACTIVITY TO END NEXT 1 TO 2
HOURS WITH LOSS OF HEATING AND PER LATEST HRRR OUTPUT.
PREV DISC...
COLD FRONT CONTINUES ITS MARCH THRU THE FORECAST AREA...AND IS
CLEARING THE WESTERN MAINE COAST AT THIS HOUR. THE ONLY PORTION
OF THE FORECAST AREA REMAINING IN THE WARM SECTOR IS SOUTHEAST
NH...WHICH WILL ONLY BE FOR THE NEXT COUPLE OF HOURS AT MOST.
ANY REMAINING POP WILL CONFINED TO THIS AREA OF NH...WITH RAPID
DRYING FROM THE N.
DEWPOINTS ARE DROPPING INTO THE 50S AS THE DRIER AIR MASS WORKS
INTO THE REGION. AIR MASS IS SEASONABLY COOL...BUT THE CENTER OF
THE COLDEST TEMPERATURES ALOFT WILL DELAY IN ARRIVING UNTIL LATE
THURSDAY INTO FRIDAY. THUS WENT SLIGHTLY WARMER THAN GUIDANCE
TONIGHT...AS COLD ADVECTION WILL KEEP A SOMEWHAT MIXED BOUNDARY
LAYER.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
HIGH PRESSURE SETTLES OVER THE REGION THURSDAY AND THURSDAY NIGHT.
IT WILL BE A SPECTACULAR DAY THURSDAY...AS WARM TEMPERATURES
COMBINE WITH LOW DEWPOINTS FOR A VERY COMFORTABLE SUMMER DAY. NW
BREEZE WILL WEAKEN...ESPECIALLY LATE IN THE DAY...ALLOWING SEA
BREEZE TO PUSH INLAND LATE IN THE AFTERNOON.
WITH SKIES CLEAR AND WINDS LIGHT...TEMPERATURES WILL TUMBLE AFTER
SUNSET THURSDAY. UNDERCUT MODEL GUIDANCE...ESPECIALLY NORTHERN
VALLEYS...AS IDEAL RADIATIONAL COOLING CONDITIONS SET UP. ALSO
EXPECT VALLEY FOG TO BE MORE PREVALENT THURSDAY NIGHT...AS LACK
OF GRADIENT WILL REDUCE ANY POTENTIAL MIXING.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE MOVES EAST ON FRIDAY SETTING UP RETURN SOUTHERLY
LOW LEVEL FLOW OVER THE REGION. THIS WILL BRING IN SLIGHTLY WARMER
AND MORE HUMID AIR FOR FRIDAY THOUGH IT SHOULD REMAIN A DRY DAY.
A SHORTWAVE TROUGH MOVING QUICKLY THROUGH SOUTHERN CANADA WILL
SEND A WEAK SURFACE LOW PRESSURE SYSTEM THROUGH THE NORTHERN GREAT
LAKES AND EASTWARD ALONG THE CANADIAN BORDER INTO MAINE BY
SATURDAY. EXPECT SHOWERS ASSOCIATED WITH THIS SYSTEM TO ARRIVE AS
EARLY AS FRIDAY NIGHT OR EARLY SATURDAY MORNING. THE BEST CHANCE
OF RAIN AND THE HEAVIEST PRECIPITATION WILL BE IN NORTHERN AREAS
WHERE A WARM FRONT MAY BECOME ESTABLISHED. SOUTH OF THIS WARM
FRONT... LOW LEVEL MOISTURE MAY COMBINE WITH DECREASING
TEMPERATURES ALOFT WITHIN THE SHORTWAVE TROUGH TO PRODUCE DIURNAL
INSTABILITY FOR THUNDERSTORMS MAINLY OVER NEW HAMPSHIRE. WIND
SHEAR IS A BIT MARGINAL FOR SEVERE THUNDERSTORMS BUT THEY CANNOT
BE RULED OUT.
SURFACE LOW WILL DROP SOUTHEAST INTO THE GULF OF MAINE BY SUNDAY
MORNING AS UPPER LEVEL RIDGING BUILDS TO THE WEST AND NORTH. COULD
STILL SEE A FEW SHOWERS ON SUNDAY AS THE LOW LINGERS NEARBY
ESPECIALLY OVER COASTAL MAINE. TEMPERATURES REACH THE 70S BUT WILL
RISE INTO THE 80S OVER SOUTHERN NEW HAMPSHIRE FURTHER AWAY FROM
THE MARITIME AIR ASSOCIATED WITH THE OFFSHORE LOW.
AS LOW PRESSURE WEAKENS IT IS ALSO SHOVED FURTHER SOUTHEAST BY A
BUILDING SURFACE HIGH OVER THE CANADIAN MARITIMES. THIS WILL SET
UP AN EASTERLY FLOW OVER MAINE AND EASTERN NEW HAMPSHIRE ON
MONDAY... WITH LOW CLOUDS BECOMING LIKELY ALONG WITH A CHANCE OF
DRIZZLE OR LIGHT SHOWERS. TEMPERATURES ARE CURRENTLY FORECAST TO
REACH THE 70S THOUGH THIS MIGHT BE A LITTLE ON THE HIGH SIDE IF
MOIST EASTERLY FLOW KEEPS THE COOL AIR AND LOW CLOUDS IN MOST OF
THE DAY.
THE NEXT LARGER SCALE FRONTAL SYSTEM MOVES IN FROM THE WEST ON
TUESDAY... WITH ANOTHER ROUND OF SHOWERS EXPECTED AS IT DOES SO.
THERE ARE SOME TIMING DIFFERENCES AMONG THE MODELS WHICH GIVE SOME
UNCERTAINTY. IF THE TIMING LINES UP RIGHT... THERE COULD BE
THUNDERSTORMS FORMING ALONG AND AHEAD OF THE FRONT ON TUESDAY.
HIGH PRESSURE BUILDS IN BEHIND THE FRONT AND COULD LEAD TO A
PERIOD OF DRIER WEATHER.
&&
.AVIATION /22Z WEDNESDAY THROUGH MONDAY/...
SHORT TERM...HIGH PRESSURE BUILDS IN TONIGHT...PROVIDING QUIET
WEATHER THRU THURSDAY NIGHT. ONLY POTENTIAL RESTRICTIONS WILL BE
IN VALLEY FOG. MODEL GUIDANCE SUGGESTS LEB AND HIE WILL DROP TO
IFR OR LOWER TONIGHT. HOWEVER...FEEL THAT AS COOLER AIR MASS
ADVECTS IN THE MODELED COOL TEMPERATURES AND FOG WILL HAVE A
HARDER TIME DEVELOPING. BEST CHANCE FOR VALLEY FOG APPEARS TO BE
THURSDAY NIGHT AND FRIDAY MORNING...AS HIGH PRESSURE SETTLES
OVERHEAD AND WINDS GO CALM.
LONG TERM...SHOULD SEE VFR CONDITIONS THROUGH FRIDAY. SOME SHOWERS
BEGIN ARRIVING LATE FRIDAY NIGHT AND COULD BRING MVFR OR IFR
CONDITIONS AT TIMES THROUGH SATURDAY NIGHT. GRADUALLY IMPROVING
CONDITIONS ON SUNDAY. AN EASTERLY FLOW ON MONDAY MAY BRING IN SOME
LOWER CLOUDS AND FOG OR DRIZZLE TO LOCATIONS EAST OF THE
MOUNTAINS.
&&
.MARINE...
SHORT TERM...WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SCA
CRITERIA THROUGH THURSDAY NIGHT...ALTHOUGH SEAS MAY APPROACH 5 FT
ON THE OUTER WATERS TONIGHT...MAINLY DUE TO SWELL.
LONG TERM...A PROLONGED SOUTHERLY FLOW MAY ALLOW WAVE HEIGHTS TO
INCREASE TO 5 FEET OR HIGHER MAINLY OVER THE EASTERN WATERS BY
SATURDAY NIGHT. THIS SHOULD DIMINISH WITH TIME ON SUNDAY AS WEAK
LOW PRESSURE MOVES SOUTHEAST THROUGH THE GULF OF MAINE.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
ES
AREA FORECAST DISCUSSION
NWS JACKSON MS
430 PM CDT WED JUL 15 2015
.DISCUSSION...A LOOSE LOW LEVEL CONVERGENT BOUNDARY LEFT IN THE WAKE
OF ORGANIZED MIDSOUTH STORMS YESTERDAY IS NOW ALIGNED FROM LIT ESE
TO BHM AND TRIGGERING SCATTERED THUNDERSTORMS. THIS BOUNDARY IS ALSO
ESSENTIALLY WORKING TO POOL BOUNDARY LAYER MOISTURE IN MY NORTHERN
ZONES...SPIKING HEAT INDICES ABOVE 110 IN SOME CASES AND DRIVING
SBCAPE VALUES UP TO NEARLY 6000 J/KG. MY LATE MORNING ASSESSMENT DID
NOT QUITE ANTICIPATE SO MUCH CAPE MATERIALIZING ALONG THE BOUNDARY
THIS AFTERNOON...BUT WITH THE NEW INFO IT SEEMS THE HIGH INSTABILITY
COULD INDEED OVERCOME CAPPING AND LACK OF SYNOPTIC FORCING
RESERVATIONS FROM EARLIER. FOR THAT REASON WE INCLUDED A LIMITED
RISK OF SEVERE STORMS IN THE HWO ACROSS BASICALLY NORTHERN AND
CENTRAL ZONES THROUGH THIS EVENING AS LATEST HRRR THINKING OF VERY
LOOSELY ORGANIZED STORM SEGMENTS ADVANCING SOUTHWARD INTO THE
EVENING LOOKS ENTIRELY BELIEVABLE. THE MAIN THREAT WITH THIS
ACTIVITY WILL BE DAMAGING WINDS GUSTS ALTHOUGH TREMENDOUS RAINFALL
RATES MAY BE CAPABLE OF VERY ISOLATED FLOODING ISSUES. ALSO EXPECT
SOME EXTREME LIGHTNING RATES FROM SOME OF THESE STORMS ALONG THE
HIGHWAY 82 CORRIDOR...WHICH IS OF COURSE ALWAYS A HAZARD.
THE HEAT IS THE OTHER BIG...AND CONTINUING...STORY. THE PREVIOUSLY-
MENTIONED EXTREME SPIKE IN HEAT INDEX VALUES UP IN THE ARKLAMISS
DELTA THIS AFTERNOON HAS BRIEFLY EXCEEDED EXCESSIVE HEAT WARNING
CRITERIA AND THERE WAS TALK OF PERHAPS GOING WITH A HEAT WARNING IN
THOSE SPOTS THROUGH TOMORROW. HOWEVER...UPON FURTHER
CONSIDERATION...WE DECIDED TO MAINTAIN THE HEAT ADVISORY STATUS
SINCE THE MOISTURE POOLING NEAR THE CONVERGENCE ZONE SHOULD NOT BE
SUCH AN ISSUE TOMORROW AND THUS PEAK HEAT INDICES UP THERE A LITTLE
TAMER. OVERALL...THE HEAT ADVISORY IN OUR AREA FOR AREAS ALONG AND
NORTH OF ACME LA...TO JACKSON MS...TO MEI LINE THROUGH THURSDAY WAS
EXTENDED THROUGH FRIDAY. SOME LOCATIONS CURRENTLY TO THE SOUTH OF
THE ADVISORY MAY HAVE TO BE ADDED IN BEFORE FRIDAY...BUT THE CURRENT
REGIME IS OFFERING INCREASED MIXING OF DRIER DEWPOINTS ALOFT TO THE
SURFACE ACROSS SOUTHERN ZONES (WHICH IS EFFECTIVELY LIMITING PEAK
HEAT INDEX VALUES TO AROUND THE CENTURY MARK). PAST FRIDAY THERE IS
DEFINITELY DECENT POTENTIAL THAT THE HEAT WILL ACTUALLY WORSEN IN
ALL AREAS THROUGH THE WEEKEND WITH SOME ACTUAL AIR TEMPERATURES IN
SPORADIC SPOTS HITTING 100 DEGREES. IT IS AT THIS POINT THAT A
WIDESPREAD HEAT ADVISORY...AND PERHAPS EVEN SOME HEAT
WARNINGS...WILL HAVE TO BE STRONGLY CONSIDERED.
IN TERMS OF CONVECTIVE TRENDS...AFTER EVENING ACTIVITY DIMINISHES
EXPECT LITTLE POTENTIAL FOR MUCH TO LINGER OVERNIGHT WITH ANY
DIURNALLY-DRIVEN CONVECTION TOMORROW LIKELY CONFINED TO FAR EASTERN
MS (AND THEN INTO SOUTHEAST MS BY FRIDAY AFTERNOON). THE UPPER RIDGE
CENTER MIGRATING MORE FIRMLY OVERHEAD OF THE REGION DURING THIS TIME
FRAME WILL PUSH SEMI-ORGANIZED THUNDERSTORM ACTIVITY WAY NORTH AND
EAST OF OUR REGION. /BB/
&&
.AVIATION...MAINLY VFR CONDITIONS WILL PREVAIL AT MOST SITES THROUGH
THE FORECAST PERIOD. SCATTERED THUNDERSTORMS LOOK TO DEVELOP AND
SINK SOUTH INTO THE AREA THROUGH THIS EVENING. GLH/GWO/GTR MAY BE
IMPACTED WITH BRIEF GUSTY WINDS...MVFR FLIGHT CATS AND COPIOUS
LIGHTNING. TOMORROW ANY AFTERNOON ISOLATED STORMS SHOULD MAINLY BE
CONFINED TO GTR/CBM/NMM/MEI AREA. /7/BB/
&&
.PREV DISCUSSION... /ISSUED 417 AM CDT WED JUL 15 2015/
PREVIOUS LONG TERM...FRIDAY THROUGH TUESDAY...WE`RE BEGINNING TO
SOUND LIKE A BROKEN RECORD BUT...EXCESSIVE HEAT CONTINUES TO BE THE
PRIMARY FORECAST CONCERN THROUGH THE EXTENDED.
THE MID/UPPER RIDGE RESPONSIBLE FOR THE RECENT HOT STREAK WILL BUILD
EASTWARD LATE THIS WEEK AND BECOME CENTERED OVER THE DEEP SOUTH OVER
BY THE WEEKEND, BRINGING POSSIBLY THE WARMEST CONDITIONS SO FAR
DURING THIS HEAT WAVE. AT THE SURFACE HIGH PRESSURE WILL BE CENTERED
OVER THE GULF OF MEXICO, MAINTAINING MAINLY SWLY LOW LEVEL FLOW.
ALONG WITH CONTINUED ABOVE NORMAL SURFACE TEMPS, HIGHER MID LEVEL
TEMPS WILL MAKE FOR STRONGER CAPPING, ESPECIALLY THE FARTHER WEST
YOU ARE IN THE CWA. WHILE POPS (PRIMARILY ISOLATED) WILL REMAIN IN
THE FORECAST OVER SOUTHERN AND EASTERN PORTIONS OF THE AREA EACH
AFTERNOON THROUGH THE WEEKEND, MOST ACTIVITY IS EXPECTED TO BE
RATHER INNOCUOUS. THOUGH SOME MIXING WILL OCCUR DURING THE DAY,
DEWPOINTS ARE EXPECTED TO REMAIN UP IN THE 70S, ESPECIALLY ACROSS
THE ARKLAMISS DELTA. THIS MEANS TRIPLE DIGIT HEAT INDICES WILL
CONTINUE TO BE PERVASIVE DURING THE LATE MORNING AND AFTERNOON HOURS
THROUGH THE WEEKEND.
BY EARLY NEXT WEEK, THERE ARE SOME HINTS THE MID/UPPER RIDGE WILL
BEGIN TO WEAKEN OR AT LEAST THE RIDGE AXIS WILL RETROGRADE BACK
TOWARD THE LOWER PLAINS. THOUGH MODEL AGREEMENT BECOMES WORSE BY
THIS TIME FRAME, INDICATIONS ARE THAT DIURNAL CONVECTION MAY BECOME
MORE PREVALENT BY MONDAY OR TUESDAY. THE EURO EVEN HINTS AT A WEAK
FRONT MAKING A PUSH TOWARD THE AREA BY MIDWEEK. REGARDLESS, THE
PRESENCE OF MORE CLOUDS WOULD SUGGEST MAX TEMPS WILL AT LEAST BEGIN
TRENDING BACK IN THE "RIGHT" DIRECTION. /DL/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 74 95 75 95 / 15 10 4 14
MERIDIAN 72 95 74 96 / 25 21 12 17
VICKSBURG 74 95 73 95 / 11 7 3 10
HATTIESBURG 74 96 75 96 / 11 19 12 21
NATCHEZ 74 94 75 94 / 6 8 5 10
GREENVILLE 75 96 75 96 / 27 7 2 6
GREENWOOD 74 96 74 96 / 30 13 3 9
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...HEAT ADVISORY UNTIL 7 PM CDT FRIDAY FOR MSZ018-019-025>053.
LA...HEAT ADVISORY UNTIL 7 PM CDT FRIDAY FOR LAZ007>009-015-016-
023>025.
AR...HEAT ADVISORY UNTIL 7 PM CDT FRIDAY FOR ARZ074-075.
&&
$$
BB/7/DL
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1235 PM CDT WED JUL 15 2015
.UPDATE...
ISSUED AT 1019 AM CDT WED JUL 15 2015
UPDATED GRIDS/FORECAST FOR ONGOING TRENDS AND EXPECTED TRENDS THE
NEXT FEW HOURS.
THE FORECAST IS CHALLENGING TODAY. SOME TRENDS SEEM TO BE
EMERGING. THIS STRONG MCV /MESOSCALE CONVECTIVE VORTEX/ WHICH
RESULTED FROM THE LARGE RAIN/STORM AREA LATE NIGHT...IS NOW
WRAPPING THINGS UP IN THE NORTHEAST PART OF THE FORECAST AREA.
DO BELIEVE THAT TREND WILL CONTINUE...WITH MAYBE A BIT OF
REDEVELOPMENT IN THAT REGION EARLY THIS AFTERNOON BUT MAY NOT
BE MORE THAN A FEW SHOWERS.
THE MCV IS STRONG...AND IS PRODUCING A STRONG SUBSIDENT REGION
IN ITS WAKE...WHICH WILL BE A DETERRENT TO AFTERNOON THUNDERSTORM
DEVELOPMENT FOR A LARGE PART OF THE AREA. THE AFTERNOON SEVERE
RISK IS LESS...SIMPLY BECAUSE WE ARE GOING TO HAVE TROUBLE
OVERCOMING THE SUBSIDENT WAKE OF THE MCV...WHICH HAS ALSO BROUGHT
SOME MORE STABLE MID-LEVEL LAPSE RATES THE NEBRASKA COUNTIES. DID
LOWER PRECIPITATION CHANCES MANY AREAS TODAY.
TO THE SOUTH...IN NORTH CENTRAL KANSAS...THIS MAY BE A MORE
ENLIGHTENED AREA FOR THUNDERSTORM DEVELOPMENT LATE THIS AFTERNOON
AND EVENING. THERE IS A WEAK SURFACE TROF ACCESS FROM KHLC TO WEST
OF KGCK...AND THE HRRR HINTS AT DEVELOPMENT IN THAT REGION...AND
THE 4KM NAM FIRES THAT LINE AS WELL TOWARD EVENING. ITS A TOUGH
CALL...BUT ITS SEEMS A MORE FAVORED AREA FOR A STRONG/SEVERE
STORM WOULD BE THE NORTH CENTRAL KANSAS REGION...POSSIBLY UP TO
SUPERIOR AND HEBRON.
IN GENERAL...A MORE WIDESPREAD SEVERE RISK SEEMS TO HAVE
DIMINISHED FOR MUCH OF THE AREA DUE TO THE MCV PASSAGE...
BUT STILL NOT TOTALLY OUT OF THE FORECAST ACROSS THE
SOUTH WHERE MORE FAVORABLE INSTABILITY...SHEAR AND SOME
WEAK CONVERGENCE MAY BE SUFFICIENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 440 AM CDT WED JUL 15 2015
PORTIONS OF THE AREA CONTINUE TO BE AFFECTED BY A COMPLEX OF
SHOWERS/THUNDERSTORMS EARLY THIS MORNING...MAINLY ALONG AND W/SW
OF A LXN TO JEWELL/KS LINE. DRIVEN BY AN UPPER LEVEL SHORTWAVE
DISTURBANCE AND MOISTURE/WARM AIR ADVECTION ASSOCIATED WITH AN
INCREASED LLJ...THIS COMPLEX HASNT EXACTLY BEEN MOVING QUICKLY TO
THE E/NE...THOUGH THE STRONGEST PORTION WHICH SHIFTED ACROSS
ROOKS/OSBORNE/MITCHELL COUNTIES IS WORKING ITS WAY OUT OF THE CWA.
AT THE SFC...A PRETTY WEAK PATTERN IS IN PLACE...WITH AN AREA OF
LOWER PRESSURE OVER THE WRN HALF OF KS...ANY BOUNDARIES THAT HAD
BEEN IN PLACE ARE BEING/WILL BE AFFECTED BY ONGOING ACTIVITY.
THE PRIMARY FORECAST FOR THE SHORT TERM LIES WITH PRECIPITATION
CHANCES AND POTENTIAL FOR SEVERE WEATHER. WANT TO STATE RIGHT OFF
THAT OVERALL CONFIDENCE IN EXACTLY HOW THINGS ARE GOING TO PLAY
OUT OVER THE NEXT 12-18 HOURS IS NOT HIGH. THINKING IS THAT THE
COMPLEX CURRENTLY SHIFTING THROUGH THE REGION WILL CONTINUE TO DO
SO THIS MORNING...AND SHOULD GIVE A CHUNK OF THE CWA AT LEAST
SOMEWHAT OF A BREAK IN THE ACTION TODAY. THERE ARE A FEW
DIFFERENCES BETWEEN MODELS AS WE GET INTO THIS AFTERNOON/EVENING
LOOKING AT QPF OUTPUT...VARYING BETWEEN NOT MUCH TO THE NEXT ROUND
AFFECTING MUCH OF THE CWA.
BROAD UPPER LEVEL SHORTWAVE TROUGHING LOOKS TO REMAIN IN THE
REGION FOR MUCH OF THE PERIOD...WITH MODELS SOWING SFC LOW
PRESSURE DEEPENING SOME OVER WRN PORTIONS OF KS LATER TODAY. STILL
LOOKING AT THE POTENTIAL FOR A SFC TROUGH AXIS/WARM FRONTAL
BOUNDARY TO EXTEND FROM THAT WRN SFC LOW THROUGH PORTIONS OF THE
CWA...BUT CONFIDENCE IN WHERE EXACTLY THAT MAY SET UP IS LOW...AND
WONT BE MORE APPARENT UNTIL THIS ONGOING ACTIVITY SHIFTS OUT AND
CAN SEE HOW OUTFLOW BOUNDARIES AFFECT THINGS. IF THE AREA GETS A
CHANCE TO "RECOVER" THROUGH THE DAY FROM CURRENT
CONDITIONS...MODELS CONTINUE TO SHOW AN AXIS OF STRONG INSTABILITY
DEVELOPING NEAR/NORTH OF THAT BOUNDARY WITH MOISTURE POOLING.
WHILE CURRENT DEEPER LAYER SHEAR IS WEAK...THAT IS EXPECTED TO
IMPROVE SOME WITH TIME...WITH LOW LEVEL SHEAR ALSO PICKING UP THIS
EVENING AS THE LLJ INCREASES. THE CWA SITS IN THE SPC DAY 1 SLIGHT
RISK AREA...WITH ALL MODES OF SEVERE WEATHER STILL A POSSIBILITY.
THOUGH HAIL/WINDS/HEAVY RAIN LOOK TO BE THE PRIMARY HAZARDS...CANT
COMPLETELY RULE OUT THE TORNADO THREAT WITH MORE THAN SUFFICIENT
INSTABILITY/GOOD LOWER LEVEL MOISTURE AND SFC BOUNDARIES IN THE
AREA.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 440 AM CDT WED JUL 15 2015
THE BIGGEST ISSUE REVOLVES AROUND DETERMINING CHANCE OF
PRECIPITATION THROUGHOUT MOST OF THE LONG TERM FORECAST AS WELL AS
STRONG/SEVERE THUNDERSTORM POTENTIAL.
FLOW WILL REMAIN MAINLY ZONAL AS WE REMAIN UNDER CONSIDERABLE
INFLUENCE OF THE SUBTROPICAL HIGH/RIDGE IN THE SOUTH. A SURFACE
TROUGH WILL LIKELY BE DRAPED SOMEWHERE OVER THE CWA...WHICH WILL
PROVIDE A FOCUS FOR NEW THUNDERSTORM DEVELOP BY LATE AFTERNOON AND
INTO THE EVENING AS THE HEAT OF THE DAY WILL INCREASE
INSTABILITY. LEFTOVER OUTFLOW BOUNDARIES WILL BE ANOTHER
POSSIBILITY FOR A FOCUS OF CONVECTION. AT ANY
TIME...ESSENTIALLY...A LOW-AMPLITUDE WAVE WILL BE POSSIBLE WITHIN
ZONAL FLOW WHICH WILL ALSO HELP SPARK CONVECTION. A SIMILAR
SCENARIO EXISTS FOR FRIDAY AFTERNOON/NIGHT. STRONG TO MARGINALLY
SEVERE THUNDERSTORMS WILL BE POSSIBLE FOR THURSDAY THROUGH FRIDAY
NIGHT...BUT THIS WILL BE LARGELY DIURNALLY DRIVEN AS DEEP LAYER
SHEAR WILL BE GENERALLY AROUND 30 KTS...WHICH IS NOT ALL THAT
IMPRESSIVE.
NO HUGE CHANGES TO THE GENERAL PATTERN HERE...EXCEPT FOR A
NORTHERN STREAM SHORTWAVE TROUGH TREKING THROUGH THE
NORTHERN/CENTRAL PLAINS SUNDAY/SUNDAY NIGHT WHICH MAY COOL DOWN
TEMPERATURES TO NEAR NORMAL. I NUDGED UP TEMPERATURES A BIT FOR
THURSDAY/FRIDAY COMPARED TO THE PREVIOUS FORECAST. ITS STILL A BIT
EARLY TO DETERMINE STRONG/SEVERE THUNDERSTORM CHANCES PAST FRIDAY
NIGHT.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1229 PM CDT WED JUL 15 2015
MCV PASSING BY THE REGION WILL HAMPER ADDITIONAL PRECIPITATION
DEVELOPMENT THIS FORECAST PERIOD...AND LIKELY KEEP VFR CONDITIONS
MORE PREVALENT THAN ONCE EXPECTED. SURFACE FLOW IS WEAK SO WINDS
WILL REMAIN BELOW 10KTS THROUGH THE PERIOD...ALTHOUGH THEY MAY
TAKE ON A MORE WEST/NORTHWEST BENT LATE TONIGHT. LOOK FOR MID
HIGH CLOUDS THIS AFTERNOON...WITH POSSIBLY AN MVFR CEILING
FROM TIME TO TIME WAS SUNSHINE INCREASES IN WARM ADVECTION ZONE
BEHIND MCV. INCLUDED THUNDERSTORMS IN THE VICINITY OF THE KGRI
WITH MODELS SUGGESTING NORTH CENTRAL KANSAS LATE THIS EVENING
COULD GRAZE BY THE AREA. CONFIDENCE IS LOW KGRI WOULD ACTUALLY
HAVE A THUNDERSTORM THOUGH TO BE HONEST.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...NOAA/NWS/MORITZ
SHORT TERM...ADP
LONG TERM...HEINLEIN
AVIATION...NOAA/NWS/MORITZ
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1050 AM PDT WED JUL 15 2015
.SYNOPSIS...DRY CONDITIONS WITH NEAR NORMAL TEMPERATURES WILL
PERSIST THROUGH FRIDAY BEFORE SOME CHANGES BEGIN TO TAKE PLACE FOR
THE WEEKEND. MOISTURE IS EXPECTED TO GET PUSHED NORTH BY HURRICANE
DOLORES LATE FRIDAY INTO SATURDAY AND REMAIN IN PLACE ACROSS THE
AREA THROUGH MONDAY. THIS SHOULD RESULT IN PLENTY OF CLOUDS ALONG
WITH THE POTENTIAL FOR SHOWERS AND THUNDERSTORMS...SOME OF WHICH
COULD PRODUCE LOCALLY HEAVY RAIN.
&&
.UPDATE...RECENT ANALYSES AND 12Z MODELS INDICATE THE AIR MASS OVER
THE FORECAST AREA HAS DRIED IN THE PAST 24 HOURS WITH PW VALUES
LOWERING AROUND A QUARTER INCH AT PW SITES. A MINOR UPDATE WAS MADE
TO REDUCE THE 15 POPS IN NORTHEAST MOHAVE COUNTY NEAR PIPE SPRING
THIS AFTERNOON. ALSO...WINDS WERE UPDATED BASED ON THE LATEST
OBSERVATIONS AND HRRR FORECAST. WILL BE TAKING A CLOSE LOOK AT
MEDIUM RANGE AND ENSEMBLE GUIDANCE FOR THE POTENTIAL MOISTURE INFLUX
THIS WEEKEND. CONFIDENCE IS STILL LOW IN NORTHWARD EXTENT OF THE
MOISTURE DUE TO A TROUGH DROPPING INTO THE NORTHWEST STATES.
&&
.AVIATION...FOR MCCARRAN...LIGHT EAST-SOUTHEAST WIND COMPONONET WILL
GIVE WAY TO A PUSH OF STRONGER SOUTH-SOUTHWEST WINDS AROUND
20Z...GIVE OR TAKE AN HOUR. WIND SPEEDS DURING THE AFTERNOON WILL BE
IN THE 10-15 KT RANGE WITH GUSTS AS HIGH AS 25 KTS.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...DRY AND CLEAR CONDITIONS EXPECTED ACROSS THE AREA WITH
EXCEPTION OF SOME ISOLATED BUILD UPS IN THE SIERRA WEST OF KBIH.
SOUTHERLY WINDS OF 10-15KT WITH GUSTS TO 25KTS EXPECTED DURING THE
AFTERNOON HOURS.
&&
.PREV DISCUSSION...
240 AM PDT WED JUL 15 2015
.SHORT TERM...THROUGH THURSDAY NIGHT.
FAIRLY TRANQUIL CONDITIONS EXPECTED IN THE SHORT TERM THANKS TO A
DRY SOUTHWESTERLY FLOW OVER THE AREA COURTESY OF A WEAK UPPER LEVEL
TROUGH OVER CALIFORNIA. THE ONLY EXCEPTION TO THE DRY CONDITIONS
WILL BE ACROSS THE HIGHEST TERRAIN OF THE SIERRA WHERE AND ISOLATED
SHOWER OR THUNDERSTORM COULD DEVELOP DURING THE AFTERNOON AND
EVENING HOURS. HOWEVER...ANY RAINFALL IS EXPECTED TO BE QUITE LIGHT.
I ALSO ADDED VERY SLIGHT POPS FOR FAR NORTHEAST MOHAVE COUNTY WHICH
SAW SOME ACTIVITY MONDAY AND MAY HAVE JUST ENOUGH INSTABILITY TO
FOSTER A FEW CUMULUS BUILD UPS AND PERHAPS AND ISOLATED SHOWER OR
STORM THIS AFTERNOON.
OTHERWISE...DRY CONDITIONS WILL PERSIST THROUGH THURSDAY WITH NEAR
NORMAL TEMPERATURES. WINDS WILL BE BREEZY AT TIMES DURING THE
AFTERNOON HOURS EACH DAY.
.LONG TERM...FRIDAY THROUGH TUESDAY.
AFTER TWO DAYS OF GOOD MODEL CONTINUITY AND AGREEMENT SOME
DIFFERENCES CREPT INTO THE 00Z CYCLE. THE DIFFERENCES REVOLVE AROUND
THE HANDLING OF A TROUGH DROPPING SOUTH INTO THE NORTHERN
ROCKIES/PAC NW OUT OF WESTERN CANADA IN THE COMING DAYS.
00Z GFS AND ABOUT HALF OF ITS ENSEMBLE MEMBERS PROGRESS THE TROUGH
FURTHER SOUTHEAST INTO THE GREAT BASIN WHICH WOULD KEEP A STRONGER
SOUTHWEST FLOW ACROSS THE GREAT BASIN BASICALLY KEEPING ANY TROPICAL
MOISTURE INTRUSION CONFINED TO THE SOUTHERN FORECAST AREA, CLARK,
MOHAVE AND SAN BERNARDINO COUNTIES. EVEN THOUGH THE TROPICAL
MOISTURE DOES NOT MAKE IT AS FAR AS LINCOLN COUNTY THERE STILL LOOKS
TO BE A CHANCE OF SHOWERS OR THUNDERSTORMS ASSOCIATED WITH THE
TROUGH PASSAGE SUNDAY. THERE WAS LITTLE CHANGE WITH THE 00Z ECMWF
FROM PREVIOUS RUNS.
FOR NOW, NOT JUMPING ON THIS ONE RUN OF THE GFS SO ONLY MADE SOME
MINOR ADJUSTMENTS. HOPING FOR BETTER MODEL CLARITY IN THE COMING
DAYS.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
UPDATE/AVIATION...ADAIR
SHORT TERM...OUTLER
LONG TERM...PIERCE
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
104 PM CDT WED JUL 15 2015
.UPDATE...
ISSUED AT 1256 PM CDT WED JUL 15 2015
OUTFLOW BOUNDARY FROM EARLIER STORMS THAT WERE NEAR CARRINGTON-
JAMESTOWN HAVE PUSHED SOUTHEAST AND ENTERED A VERY UNSTABLE
AIRMASS WITH ML CAPES OF 2500 AND SFC BASED CAPE VIA SPC MESO PAGE
OF 4000 J/KG FROM NEAR LINTON ND TO LAMOURE ND THEN TOWARD FARGO.
THIS AREA NEEDS TO BE WATCHED FOR ANY SEVERE STORMS AND DID ADD
THIS AREA TO T+ IN THE GRIDS. DOWNFALL IS WEAK BULK SHEAR FOR
SUSTAINED UPDRAFTS/SUPERCELLS SO ANY SEVERE SHOULD BE RATHER BRIEF
AND LIMITED. OTHERWISE UNSURE HOW THE REST OF THE FCST AREA WILL
UNFOLD THIS AFTN/EVE AS A BIT CLOUDIER AND LESS UNSTABLE AIRMASS
IN NE ND/NW MN. MAIN SHORT WAVE DUE TO ARRIVE LATE TONIGHT INTO
THURSDAY AND WOULD EXPECT SOME CLUSTERS OF STORMS LATER TONIGHT
INTO THURSDAY. CHATTED WITH SPC ABOUT DAY 2 AND FOR NOW THEY WILL
KEEP US IN GENERAL.
.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 328 AM CDT WED JUL 15 2015
CONVECTION TIMING AND STRENGTH WILL BE THE MAIN FORECAST ISSUES
FOR THE SHORT TERM.
UPPER RIDGING CONTINUES TO BUILD OVER THE PLAINS...BUT WV LOOP
SHOWS SEVERAL WEAK EMBEDDED SHORTWAVES HEADED INTO THE REGION. SFC
LOW PRESSURE WILL BE DEVELOPING TO OUR WEST...AND SOUTH WINDS WILL
HELP KEEP PLENTY OF MOISTURE IN THE REGION. SOME STORMS HAVE
ALREADY STARTED TO DEVELOP OVER WESTERN ND IN RESPONSE TO ONE OF
THE WEAK SHORTWAVES. 06Z HRRR HAS SOME CONVECTION FIRING IN THAT
AREA...BUT SEEMS TO FIZZLE IT OUT AND DEVELOP STORMS FURTHER SOUTH
NEAR THE SD BORDER. A FEW STORMS HAVE BEEN FIRING OVER NORTHERN
MN...MOSTLY TO OUR EAST BUT SHORT RANGE MODELS PERSIST IN BREAKING
OUT SOME CONVECTION OVER THE FAR EASTERN TIER DURING THE EARLY
MORNING HOURS.
OUT OF THE SHORT RANGE MODELS THE HRRR SEEMS TO HAVE THE BEST
HANDLE ON WHAT IS CURRENTLY GOING ON...AND EVEN THEN IT IS NOT
PERFECT. THINK THAT THE STORMS OVER WESTERN ND WILL MOVE EAST
THROUGH THE MORNING...WITH THE DEVILS LAKE BASIN THE BEST SHOT OF
SEEING SOME CONVECTION THIS MORNING. THINK MORE VIGOROUS
CONVECTION WILL MOVE IN FROM THE WEST LATER THIS AFTERNOON AND
INTO THE EVENING AS A SHORTWAVE CURRENTLY OVER WESTERN WY COMES
OVER THE TOP OF THE RIDGE. MODEL SOUNDINGS HAVE CAPE VALUES OF
1000-1500 J/KG AND SHEAR VALUES AROUND 30 KTS...SO SOME SEVERE
LATER THIS AFTERNOON IS NOT OUT OF THE QUESTION DEPENDING ON HOW
THE MORNING CONVECTION PLAYS OUT. CONVECTION SHOULD MOVE EASTWARD
AND BECOME MORE WIDESPREAD AS THE UPPER SHORTWAVE COMES OUT INTO
THE PLAINS. THE MAIN SFC LOW WILL BE TO OUR SOUTH...ALTHOUGH THE
LATEST 06Z NAM BRINGS IT CLOSER TO OUR SOUTHERN COUNTIES THAN
PREVIOUS RUNS.
THURSDAY...THE MAIN UPPER SHORTWAVE THAT THE MODELS ARE PINGING ON
MOVES OFF INTO MN...BUT THE MODELS HAVE ANOTHER ONE FOLLOWING
SHORTLY FURTHER NORTH OVER OUR NORTHERN COUNTIES. MODELS HAVE A
GOOD AMOUNT OF QPF FOR MUCH OF THE DAY...SO KEPT POPS HIGH AND
TEMPS MAY BE SUPPRESSED A BIT BY ONGOING PRECIP SO HAVE MORE
READINGS IN THE UPPER 70S. DO NOT AT THIS POINT THINK THERE WILL
BE MUCH SEVERE DUE TO WEAK DEEP LAYER BULK SHEAR VALUES.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 328 AM CDT WED JUL 15 2015
THURSDAY NIGHT THROUGH FRIDAY NIGHT...MORE WEAK SHORTWAVE TROUGHS
COMING IN AS SOUTHWESTERLY FLOW ALOFT SETS UP OVER THE REGION.
TIMING OF PRECIP IS DIFFICULT TO TELL AT THIS POINT BUT HAVE A
BIT OF A BREAK LATE THURSDAY NIGHT BEFORE THE NEXT SFC TROUGH AXIS
MOVES IN FRIDAY AND SETS OFF MORE CONVECTION. KEEP POPS FAIRLY
HIGH AND TEMPS SHOULD BE NEAR SEASONAL AVERAGES ALTHOUGH SLIGHTLY
MORE MILD ON LOWS DUE TO CLOUDS AND PRECIP.
SATURDAY THROUGH TUESDAY...MODELS IN GOOD AGREEMENT WITH POSITIONING
OF UPPER LEVEL FEATURES. INDICATIONS ARE FOR A TROF DIGGING OVER
THE INTERMOUNTAIN WEST...KEEPING MORE OF A SW FLOW REGIME OVER THE
AREA. VARIOUS IMPULSES ARE EXPECTED TO PROPAGATE THRU THE
FLOW...BRINGING ENOUGH INSTABILITY TO TRIGGER SHOWERS OR STORMS
ACROSS THE AREA EACH DAY. OTHERWISE...TEMPS WILL REMAIN MAINLY ON
THE WARM SIDE...ALTHOUGH A SLIGHT COOLING MAY OCCUR NEAR THE END
OF THE PERIOD AS A WEAK UPPER TROF CROSSES ALONG THE CANADIAN
BORDER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1256 PM CDT WED JUL 15 2015
THE MAIN CHALLENGE REMAINS CONVECTIVE TRENDS. THE BEST CHANCE FOR
SHOWERS AND STORMS WILL BE IN THE SOUTH THIS AFTERNOON...THEN IN ALL
AREAS AFTER 06Z. FOR NOW WILL NOT MENTION ANY THUNDER
OVERNIGHT...BUT ADD A MENTION TO KFAR AFTER 21Z. WINDS SHOULD REMAIN
SOUTHERLY IN MOST AREAS SHIFTING MORE WESTERLY THURSDAY AFTER 18Z.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...JR
LONG TERM...JR/HOPKINS
AVIATION...DK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1244 PM CDT WED JUL 15 2015
.UPDATE...
ISSUED AT 1237 PM CDT WED JUL 15 2015
SOME THUNDERSTORMS CONTINUE OVER THE AREA...MAINLY OVER THE JAMES
RIVER VALLEY REGION. THESE SHOULD CONTINUE SPREADING EAST...THOUGH
A PAIR OF WAVES UPSTREAM...PARTICULARLY ONE MOVING THROUGH CENTRAL
MONTANA/EASTERN WYOMING...WILL RESULT IN ADDITIONAL CONVECTION
LATER THIS AFTERNOON INTO THIS EVENING. HAVE ADJUSTED POPS TO
REFLECT THIS. PARAMETERS STILL IN PLACE FOR SOME STORMS TO BECOME
SEVERE.
UPDATE ISSUED AT 846 AM CDT WED JUL 15 2015
THUNDERSTORMS CONTINUE OVER CENTRAL NORTH DAKOTA WITH CURRENT WAVE
MOVING THROUGH. UPPER LEVEL ANALYSIS SHOWS ANOTHER PAIR OF WAVES
APPROACHING THE AREA WITH THE FIRST ONE OVER EASTERN MONTANA AND
THE SECOND ONE OVER WESTERN MONTANA/WYOMING INTO EASTERN IDAHO.
THEREFORE...HAVE SPREAD THUNDERSTORM CHANCES ACROSS THE AREA
THROUGH THE REMAINDER OF THE DAY. STORMS HAVE BEEN REMAINING UNDER
SEVERE LIMITS THIS MORNING THOUGH THERE IS STILL SOME POTENTIAL
FOR SEVERE IN THE AFTERNOON/EARLY EVENING AS INSTABILITY INCREASES
AND SHEAR REMAINS MARGINAL.
UPDATE ISSUED AT 646 AM CDT WED JUL 15 2015
INCORPORATED RADAR TRENDS THROUGH 1145 UTC...BLENDED TO A TIME
LAGGED ENSEMBLE OF THE 08-10 UTC HRRR ITERATIONS INTO THE
AFTERNOON AND SUPPORTED BY THE 06 UTC GFS WHICH HAVE HAD THE BEST
DEPICTION OF MORNING CONVECTION THUS FAR.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM CDT WED JUL 15 2015
FOCUS IN THE SHORT TERM IS ON CHANCES FOR THUNDERSTORMS WEDNESDAY.
UPPER LEVEL RIDGE REMAINS CENTERED OVER NORTH DAKOTA EARLY THIS
MORNING. THROUGH THE AFTERNOON AND EVENING THE RIDGE WILL PROPAGATE
EAST ALONG WITH A WEAK SURFACE BOUNDARY. AMPLE CAPE AND MARGINAL
BULK SHEAR VALUES WILL MOST LIKELY PRODUCE NUMEROUS THUNDERSTORMS
ACROSS WESTERN AND CENTRAL NORTH DAKOTA THIS AFTERNOON AND TONIGHT.
SHORT RANGE MODELS AS OF LATE HAVE BEEN MORE MISS THAN HIT OVER THE
LAST WEEK OR SO...HOWEVER THE PREVIOUS FEW HRRR MODEL RUNS HAVE BEEN
FAIRLY CONSISTENT WITH NUMEROUS STORMS SETTING UP FROM THE TURTLE
MOUNTAINS INTO SOUTHWESTERN NORTH DAKOTA AROUND 18 UTC AND THEN
PROPAGATING EAST. WITH THAT SAID THE HRRR HAS NOT DONE WELL WITH THE
STORMS THAT WILL NOT SEEM TO STOP ACROSS WILLIAMS AND MCKENZIE
COUNTIES EARLY THIS MORNING. THUS HAVE WENT WITH A BLEND BETWEEN THE
HRRR AND LONGER RANGE MODELS FOR TODAY THROUGH TONIGHT.
THE SPC WEDNESDAY OUTLOOK CONTINUES TO SHOW NORTH DAKOTA IN A SLIGHT
RISK FOR SEVERE THUNDERSTORMS...WITH THE MAIN RISK AS LARGE HAIL AND
GUSTY WINDS. AS OF NOW HAVE A MENTION OF SEVERE IN THE GRIDS
STARTING AT 18 UTC AND PERSISTING INTO THE NIGHT. JUDGING BY THE
POTENTIALLY STRONG STORMS ALREADY IN PLACE IN THE NORTHWEST IT IS
CERTAINLY POSSIBLE TO SEE SEVERE THUNDERSTORMS POP UP EARLY THIS
AFTERNOON.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 316 AM CDT WED JUL 15 2015
AN ACTIVE WEATHER PATTERN CONTINUES TO HIGHLIGHT THE EXTENDED
FORECAST.
THE 00 UTC GLOBAL DETERMINISTIC AND ENSEMBLE SUITES ARE IN
AGREEMENT ON QUASI-ZONAL FLOW ALOFT ACROSS THE NORTHERN PLAINS
THURSDAY AND FRIDAY TRANSITIONING TO SOUTHWEST THIS WEEKEND AS A
POSITIVELY TILTED NORTHERN CONUS AND CANADIAN ROCKIES TROUGH
MODESTLY AMPLIFIES BEFORE PROPAGATING DOWNSTREAM OF THE REGION
INTO EARLY NEXT WEEK. AS A RESULT...DAILY CHANCES FOR
THUNDERSTORMS ARE FORECAST TO CONTINUE THURSDAY THROUGH AT LEAST
SATURDAY...BEFORE A POTENTIAL DECREASE IN STORM ACTIVITY NEXT
WEEK. WHILE THE SEVERE THREAT IS NON-ZERO THURSDAY AND MORE SO ON
FRIDAY AHEAD OF THE SURFACE COLD FRONT...UNCERTAINTY IS TOO HIGH
AT THIS TIME TO ADD A SEVERE MENTION TO THE GRIDS. THIS IS IN LINE
WITH THE SPC OUTLOOK SUITE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1237 PM CDT WED JUL 15 2015
SCT TSRA WILL INCREASE IN COVERAGE TONIGHT...BRINGING LCL IFR VIS
IN HEAVIER PRECIP. STORMS WILL CONTINUE OVERNIGHT INTO THURSDAY
MORNING. MODELS ARE HINTING AT SOME FOG POSSIBLY DEVELOPING LATE
TONIGHT OVER PORTIONS OF WESTERN AND CENTRAL NORTH DAKOTA...THOUGH
WILL WAIT TO SEE IF NEXT MODELS RUNS ALSO ADVERTISE THIS BEFORE
MENTIONING IN INDIVIDUAL TERMINAL FORECASTS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...MM
LONG TERM...AYD
AVIATION...JJS
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
247 PM EDT WED JUL 15 2015
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL DRY OUT THE REGION AS AN UPPER LEVEL
RIDGE BUILDS IN FROM THE WEST...BRINGING WITH IT A RETURN TO ABOVE
NORMAL TEMPERATURES THROUGH LATE THIS WEEK. BETTER COVERAGE OF
AFTERNOON SHOWERS AND THUNDERSTORMS WILL RETURN OVER THE
WEEKEND...WITH ANOTHER FRONT EXPECTED EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
AT 1230 PM...CU FIELD A BIT MORE EXTENSIVE THAN PREVIOUS GRIDS.
ESPECIALLY OVER THE PIEDMONT. HENCE...HAVE INCREASED SKY COVER
WITH THIS UPDATE. THIS ALSO IS SLOWING THE TEMP INCREASE...SO
BACKED OFF ON MAX TEMPS BY A COUPLE DEGREES.
AT 1015 AM EDT...NO BIG CHANGES TO THE GOING FORECAST FOR TODAY.
TROUGH/WEAK FRONT ANALYZED FROM CENTRAL NC THROUGH THE UPSTATE INTO
NE GA AT 14Z. 12Z NAM SETTLES THE BOUNDARY SLOWLY SOUTHWARD INTO THE
SC MIDLANDS BY LATE AFTERNOON. THE NAM AND HRRR SHOW ISOLATED
CONVECTION FIRING OVER THE SOUTHERN UPSTATE EARLY THIS AFTERNOON SO
WILL CONTINUE THE ISOLATED POPS THERE. ALSO...THE MODELS SHOW
ISOLATED UPSLOPE SHOWERS ALONG THE TN LINE SO ISOALTED POPS LOOK
GOOD THERE. UPDATED TEMPS/DEWPOINTS WITH LATEST CONSHORT DATA WHICH
BUMPED MAX TEMPS UPWARD A DEGREE OR SO.
630 AM UPDATE...NO MAJOR CHANGES MADE TO THE GRIDS. POPS WERE
TEMPERED DOWN SRN ZONES AS LAST OF VORT PRECIP PUSHES SOUTH. TEMPS
AND TD/S REQUIRED ONLY MINOR TWEAKS WITH SFC WINDS PROVIDING MODEST
MIXING.
AS OF 255 AM EDT WEDNESDAY...AN UPPER LEVEL TROF WILL CONTINUE TO
SWING EAST THROUGH THE DAY WITH THE AXIS PASSING EAST OF THE CWFA BY
16Z/17Z. HEIGHTS WILL BEGIN TO RISE FAIRLY QUICKLY THROUGH THE
AFTERNOON WITH A STRONG H5 HIGH OVER TX NUDGING EAST. LOW LEVEL
MOISTURE SOURCES WILL BE LIMITED...WITH THE BEST POOLING ACROSS THE
MTN SPINE AIDED BY MECH LIFT AND SOME LINGERING MOISTURE SOUTH ALONG
A WEAKENING THETA/E BNDRY FROM CURRENT PRECIP SHIELD ADVANCING
SOUTH. THERE SHOULD BE ENUF LIFT ACROSS THE FAR WRN MTNS FOR
ISOL/SCT -SHRA AND PERHAPS A COUPLE TSTMS. THE SAME GOES FOR THE SRN
ZONES WHERE H5 VORT ENERGY WILL INTERACT WITH THE BNDRY AND PRODUCE
SHORT-LIVED WEAK CONVECTION BEFORE A SUBS INVERSION LIMITS CLOUDS
TO FAIR WX CU MOST LOCALES. WITH DEEP NW/LY FLOW...GOOD MIXING AND
DOWNSLOPE HEATING WILL LOWER SFC TD/S THROUGH THE AFTERNOON.
THUS...THE DAY WILL FEEL A LITTLE DRIER THAN THE PAST FEW DAYS WITH
LOW END GUSTS DEVELOPING BY MID AFTERNOON. THE OVERNIGHT WILL REMAIN
DRY AS THE MLVL FLOW MAINTAINS A N/LY SUBS PATTERN. AT THE SFC... A
RELATIVELY TIGHT PGRAD WILL SLOWLY WEAKEN AS A TROF AXIS SHIFTS
TOWARD THE COAST. SO...WITH SOME WIND AND WEAK SFC-BASED
INVERSIONS...LOWS WILL BE HELD NEAR SEASONAL LEVELS.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 230 PM EDT WEDNESDAY...THE SHORT TERM FCST PERIOD INITIALIZES
THURSDAY EVENING WITH A BROAD/ELONGATED UPPER ANTICYCLONE BUILDING
OVER THE DEEP SOUTH...WHILE A WEAK UPPER WAVE DIGS ACROSS THE UPPER
MIDWEST. AT THE SURFACE...EXPANSIVE SURFACE RIDING WILL PREVAIL
OVER THE NORTHEAST WITH A SUMMERTIME WEDGE LIKE PATTERN DOMINATES
ACROSS THE SOUTHERN/CENTRAL APPS. MODELS FAVOR EAST/NORTHEAST FLOW
AROUND SAID SURFACE HIGH WHICH COULD POTENTIALLY AID WEAK UPSLOPE
INDUCED SHOWERS ALONG THE NC HIGH TERRAIN...WHICH COULD BE ONGOING
AT FCST INITIALIZATION. FROM THAT POINT THE PATTERN WILL EVOLVE AS
THE SFC RIDGE SLOWLY EJECTS OUT TO SEA AND THE WEAK SUMMERTIME WEDGE
RETREATS INTO FRIDAY MORNING. MEANWHILE...THE UPPER ANTICYCLONE
WILL ADVECT EAST SETTING UP OVER THE MIDSOUTH THROUGH THE REMAINDER
OF THE SHORT TERM ALLOWING FLOW ALOFT TO VEER NORTHWESTERLY AND THUS
LOWERING H5 TEMPS. SOUNDINGS FAVOR SUCH AS MID/UPPER CIN DECREASES
ON FRIDAY...AND FURTHER ON SATURDAY. THE SFC PATTERN ON FRIDAY WILL
FEATURE GRADUALLY VEERING WINDS YIELDING A WEAK WAA REGIME AND THUS
INCREASED DIURNAL SHRA/TSRA CHANCES...ESPECIALLY ALONG THE HIGH
TERRAIN. IN ADDITION...AN OLD FRONTAL AXIS DRAPED ALONG THE GULF
COAST WILL PROVIDE FOCUS FOR A WEAK SFC WAVE TO DEVELOP...WHICH
COULD ENHANCE ANY EASTERLY MOISTURE ADVECTION OFF THE ATLANTIC INTO
NORTHEAST GA AND THE WESTERN CAROLINAS. ALL IN ALL...EXPECTING
CONVECTIVE INITIATION WITH HEATING ALONG THE BLUE RIDGE ON FRIDAY
EVENING LIKELY ENHANCED BY WEAK UPSLOPING. AS FOR THE LOW
TERRAIN...MODELS DO NOT FAVOR ANYTHING MORE THAN ISOLATED
CONVECTION...WHICH IS IN SOME CONTRAST WITH SOUNDING PROFILES WHICH
INDICATE EROSION OF ANY CIN BY MID/LATE AFTERNOON. EXPECTING MUCH
OF THE SAME ON SATURDAY ALBEIT WITH SLIGHT HIGHER PRECIP CONFIDENCE
AS ANY UPPER CIN IS WEAKENED FURTHER...AND LOW LEVEL MOISTURE FLUX
CONTINUES YIELDING DEWPOINTS IN THE MID/UPPER 60S AND THUS ABUNDANT
INSTABILITY.
AS FOR FCST...POPS WILL GRADUALLY INCREASE THROUGH THE PERIOD AS
PROFILES BECOME MORE FAVORABLE FOR CONVECTION EACH DAY.
THUS...CHANCE POPS ARE FEATURED OVER THE NC HIGH TERRAIN ON FRIDAY
AFTERNOON TAPERING TO SLIGHT CHANCE ACROSS THE NC/SC PIEDMONT AND
PORTIONS OF NORTHEAST GA. POPS WILL DECREASE WITH HEATING LOSS INTO
SATURDAY MORNING BEFORE INCREASING DIURNALLY TO SOLID CHANCE LEVELS
REGIONWIDE...WITH THE HIGHEST POPS STILL FOCUSED ALONG THE BLUE
RIDGE. NOT EXPECTING ANY HAZARDOUS WEATHER EITHER DAY...HOWEVER
PROFILES PRESENT THE POSSIBILITY OF MORE ORGANIZED/DEEPER
CONVECTION ON SATURDAY...THUS A FEW STRONGER THUNDERSTORMS CANNOT BE
RULED OUT. TEMPERATURES WILL GRADUALLY MODERATE THROUGH THE PERIOD
WITH NEAR NORMAL LEVELS FCST ON FRIDAY...AND SLIGHTLY ABOVE NORMAL
FOR SATURDAY REGIONWIDE.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 230 PM WEDNESDAY...THE MEDIUM RANGE PICKS UP AT 00Z SUNDAY
WITH THE H5 RIDGE OVER THE SOUTHERN CONUS CONTINUING TO RETROGRESS
TOWARDS THE SOUTHERN PLAINS. THOUGH THE FORECAST AREA WILL REMAIN ON
THE PERIPHERY OF THE UPPER HIGH...SLIGHT OVERALL HEIGHT FALLS ARE
EXPECTED THROUGH THE END OF THE WEEKEND AND EARLY NEXT WEEK. NO
PRONOUNCED LARGE SCALE FORCING MECHANISMS APPEAR TO BE PRESENT
THROUGH THE EARLY MEDIUM RANGE...THOUGH A LACK OF SUPPRESSION PLUS
SUFFICIENT MOISTURE WILL ALLOW A NORMAL PATTERN OF DIURNAL SHOWERS
AND THUNDERSTORMS TO DEVELOP. GUIDANCE DIVERGES SIGNIFICANTLY ON
MONDAY...WITH THE ECMWF CARRYING A MUCH FASTER AND DEEPER SHORTWAVE
AND ASSOCIATED COLD FRONT ACROSS THE SOUTHERN APPALACHIANS THAN THE
STUBBORNLY SLOWER GFS. THE SHORTWAVE TROUGH IS ALSO NOT AS AMPLIFIED
IN THE GFS SOLUTION...AND THE GFS BOUNDARY IS ALLOWED TO STALL OUT
ACROSS THE AREA WEDNESDAY AND INTO THURSDAY...WHILE THE ECMWF
FEATURES A CLEAN FRONTAL PASSAGE FOR THE AREA BY TUESDAY NIGHT.
REGARDLESS OF THE TIMING OF THE FRONTAL BOUNDARY...QPF RESPONSE FOR
BOTH MODELS INCREASES MONDAY AFTERNOON AND TUESDAY. WEDNESDAY AND
THURSDAY PRESENT MORE OF A CHALLENGE WITH PRONOUNCED DIFFERENCES IN
LOW LEVEL MOISTURE...AND BECAUSE NO SOLUTION CURRENTLY STANDS
OUT...THE CURRENT FORECAST FEATURING DIURNAL POPS NEAR CLIMO WAS
LEFT INTACT.
MAX TEMPS WILL REMAIN ABOVE AVERAGE...WITH A PEAK ON MONDAY BEFORE
THE FRONT APPROACHES. SOME COOLING IS EXPECTED AFTER THE FRONTAL
PASSAGE ON TUESDAY.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...BKN-SCT CU AROUND 060FT THIS AFTERNOON...THEN SCT
HIGH CLOUDS OVERNIGHT. MORE SCT-BKN CU ON THU. HOWEVER...VFR CONDS
THROUGH THE TAF PERIOD. NW WINDS DIMINISH AND WILL GRADUALLY VEER TO
THE NE OVERNIGHT.
ELSEWHERE...SCT-BKN HIGH BASED CU THIS AFTERNOON...SCATTERING OUT
TONIGHT. VFR THROUGH THE PERIOD. THE EXCEPTION WILL BE AT AVL WHERE
EARLY MORNING FOG MAY REDUCE VSBYS TO MVFR.
OUTLOOK...BUILDING UPPER RIDGE WILL PERSIST THROUGH THE END OF THE
WEEK LEADING TO LOWER PRECIP/RESTRICTION CHANCES OUTSIDE THE
MOUNTAINS. THESE CHANCES WILL INCREASE OVER THE WEEKEND AS THE RIDGE
RETROGRADES LEADING TO INCREASING DIURNAL SHRA/TSRA CHANCES AND THUS
MORNING FOG/STRATUS AS WELL.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 91% HIGH 93%
KHKY HIGH 100% HIGH 100% HIGH 100% MED 79%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.FIRE WEATHER...
RH VALUES ACROSS THE REGION WILL CONTINUE TO HOVER IN THE LOWER/MID
20S WITH A FEW SITES REPORTING IN WITH VALUES IN THE TEENS.
FORTUNATELY...WINDS REMAIN LIGHT WITH NO INCREASES IN FLOW EXPECTED.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...LEV
NEAR TERM...LG
SHORT TERM...CDG
LONG TERM...LEV
AVIATION...LG
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
143 PM EDT WED JUL 15 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE AREA TODAY. FOLLOWING THE
FRONT...SURFACE HIGH PRESSURE WILL DRY OUT THE REGION AS AN UPPER
LEVEL RIDGE BUILDS IN FROM THE WEST...BRINGING WITH IT A RETURN
TO ABOVE NORMAL TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT 1230 PM...CU FIELD A BIT MORE EXTENSIVE THAN PREVIOUS GRIDS.
ESPECIALLY OVER THE PIEDMONT. HENCE...HAVE INCREASED SKY COVER
WITH THIS UPDATE. THIS ALSO IS SLOWING THE TEMP INCREASE...SO
BACKED OFF ON MAX TEMPS BY A COUPLE DEGREES.
AT 1015 AM EDT...NO BIG CHANGES TO THE GOING FORECAST FOR TODAY.
TROUGH/WEAK FRONT ANALYZED FROM CENTRAL NC THROUGH THE UPSTATE INTO
NE GA AT 14Z. 12Z NAM SETTLES THE BOUNDARY SLOWLY SOUTHWARD INTO THE
SC MIDLANDS BY LATE AFTERNOON. THE NAM AND HRRR SHOW ISOLATED
CONVECTION FIRING OVER THE SOUTHERN UPSTATE EARLY THIS AFTERNOON SO
WILL CONTINUE THE ISOLATED POPS THERE. ALSO...THE MODELS SHOW
ISOLATED UPSLOPE SHOWERS ALONG THE TN LINE SO ISOALTED POPS LOOK
GOOD THERE. UPDATED TEMPS/DEWPOINTS WITH LATEST CONSHORT DATA WHICH
BUMPED MAX TEMPS UPWARD A DEGREE OR SO.
630 AM UPDATE...NO MAJOR CHANGES MADE TO THE GRIDS. POPS WERE
TEMPERED DOWN SRN ZONES AS LAST OF VORT PRECIP PUSHES SOUTH. TEMPS
AND TD/S REQUIRED ONLY MINOR TWEAKS WITH SFC WINDS PROVIDING MODEST
MIXING.
AS OF 255 AM EDT WEDNESDAY...AN UPPER LEVEL TROF WILL CONTINUE TO
SWING EAST THROUGH THE DAY WITH THE AXIS PASSING EAST OF THE CWFA BY
16Z/17Z. HEIGHTS WILL BEGIN TO RISE FAIRLY QUICKLY THROUGH THE
AFTERNOON WITH A STRONG H5 HIGH OVER TX NUDGING EAST. LOW LEVEL
MOISTURE SOURCES WILL BE LIMITED...WITH THE BEST POOLING ACROSS THE
MTN SPINE AIDED BY MECH LIFT AND SOME LINGERING MOISTURE SOUTH ALONG
A WEAKENING THETA/E BNDRY FROM CURRENT PRECIP SHIELD ADVANCING
SOUTH. THERE SHOULD BE ENUF LIFT ACROSS THE FAR WRN MTNS FOR
ISOL/SCT -SHRA AND PERHAPS A COUPLE TSTMS. THE SAME GOES FOR THE SRN
ZONES WHERE H5 VORT ENERGY WILL INTERACT WITH THE BNDRY AND PRODUCE
SHORT-LIVED WEAK CONVECTION BEFORE A SUBS INVERSION LIMITS CLOUDS
TO FAIR WX CU MOST LOCALES. WITH DEEP NW/LY FLOW...GOOD MIXING AND
DOWNSLOPE HEATING WILL LOWER SFC TD/S THROUGH THE AFTERNOON.
THUS...THE DAY WILL FEEL A LITTLE DRIER THAN THE PAST FEW DAYS WITH
LOW END GUSTS DEVELOPING BY MID AFTERNOON. THE OVERNIGHT WILL REMAIN
DRY AS THE MLVL FLOW MAINTAINS A N/LY SUBS PATTERN. AT THE SFC... A
RELATIVELY TIGHT PGRAD WILL SLOWLY WEAKEN AS A TROF AXIS SHIFTS
TOWARD THE COAST. SO...WITH SOME WIND AND WEAK SFC-BASED
INVERSIONS...LOWS WILL BE HELD NEAR SEASONAL LEVELS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 230 AM WEDNESDAY...THE 00Z MODEL RUNS SHOW A TREND TOWARD MORE
CONVECTIVE COVERAGE FOR LATE IN THE WEEK...IN SPITE OF THE RETURN OF
THE UPPER RIDGE FROM THE WEST AND THE LACK OF LARGE SCALE FORCING.
THAT BEING SAID...ON THURSDAY AFTERNOON THERE DOES NOT APPEAR TO BE
ANYTHING IN THE MODEL GUIDANCE TO DISCOURAGE DEEP CONVECTION EITHER.
AND...ON A TYPICAL DAY IN THE SUMMERTIME...IT IS DIFFICULT TO KEEP
CONVECTION FROM DEVELOPING ON THE RIDGETOPS GIVEN SUFFICIENT
MOISTURE AND NOTHING THAT ACTS TO PREVENT IT. WILL FOLLOW THE NEW
NAM AND PUT A SMALL PRECIP CHANCE MAINLY OVER THE HIGHEST ELEVATIONS
FOR THE AFTERNOON...AND THEN GET RID OF IT WITH LOSS OF HEATING
THURSDAY EVENING. ON FRIDAY...THE UPPER PATTERN DOES NOT CHANGE
APPRECIABLY WITH THE ANTICYCLONE CENTERED OVER ERN TX/LA...BUT THE
SFC HIGH TO THE NE SEEMS A BIT STRONGER. THE MODELS DEVELOP A WEAK
E/SE FLOW IN THE BOUNDARY LAYER WHICH ADVECTS MOISTURE INTO THE
REGION. THE RESULT IS MORE PRECIP DEVELOPMENT IN THE MODEL. AGAIN...
GIVEN NOTHING TO DISCOURAGE THIS...I EXPECT THERE WILL BE A BIT MORE
COVERAGE THAN PREVIOUSLY EXPECTED...SO PRECIP CHANCES WERE NUDGED
UPWARD A BIT WHICH BRINGS THE PROBABILITY INTO THE CHC RANGE NEAR
THE BLUE RIDGE IN THE AFTERNOON. THE CHANCES FOR ANYTHING BEYOND
GARDEN VARIETY THUNDERSTORMS APPEARS VERY LOW. TEMPS BOTTOM OUT NEAR
NORMAL ON THURSDAY AND THEN BEGIN A CLIMB BACK ABOVE NORMAL STARTING
ON FRIDAY.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 315 AM WEDNESDAY...STILL NO BIG SURPRISES NOTED IN THE LATEST
MEDIUM RANGE GUIDANCE. THE SLOW WESTWARD DRIFT OF THE UPPER
ANTICYCLONE BACK TOWARD THE SRN PLAINS WILL KEEP THE WESTERN
CAROLINAS ON ITS PERIPHERY...AND THUS AWAY FROM ITS SUPPRESSIVE
AFFECTS. THAT SHOULD ALLOW FOR MAINLY DIURNAL SHOWERS AND
THUNDERSTORMS TO DEVELOP EACH DAY GIVEN SUFFICIENT LOW LEVEL
MOISTURE. TEMPS ABOVE NORMAL LOOK LIKE A GOOD BET...BUILDING EACH
DAY TO A PEAK MOST LIKELY ON MONDAY. THE ECMWF SOLUTION SUGGESTS
THAT A SHORT WAVE PASSING TO THE NORTH ON TUESDAY WILL BRING A
WEAKENING COLD FRONT DOWN ACROSS THE AREA THAT WOULD ENHANCE PRECIP
CHANCES AND DROP TEMPS BACK DOWN A BIT. HOWEVER...THE GFS SHOWS THE
UPPER WAVE MUCH FARTHER N AND KEEPS ANY BOUNDARY WELL TO OUR N. WILL
NOT MAKE ANY SIGNIFICANT CHANGES TO THE MEDIUM RANGE AT THIS TIME...
AND THINK EVEN WITHOUT THE FRONT THE COVERAGE OF STORMS WILL
INCREASE A BIT EACH DAY ANYWAY.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...BKN-SCT CU AROUND 060FT THIS AFTERNOON...THEN SCT
HIGH CLOUDS OVERNIGHT. MORE SCT-BKN CU ON THU. HOWEVER...VFR CONDS
THROUGH THE TAF PERIOD. NW WINDS DIMINISH AND WILL GRADUALLY VEER TO
THE NE OVERNIGHT.
ELSEWHERE...SCT-BKN HIGH BASED CU THIS AFTERNOON...SCATTERING OUT
TONIGHT. VFR THROUGH THE PERIOD. THE EXCEPTION WILL BE AT AVL WHERE
EARLY MORNING FOG MAY REDUCE VSBYS TO MVFR.
OUTLOOK...BUILDING UPPER RIDGE WILL PERSIST THROUGH THE END OF THE
WEEK LEADING TO LOWER PRECIP/RESTRICTION CHANCES OUTSIDE THE
MOUNTAINS. THESE CHANCES WILL INCREASE OVER THE WEEKEND AS THE RIDGE
RETROGRADES LEADING TO INCREASING DIURNAL SHRA/TSRA CHANCES AND THUS
MORNING FOG/STRATUS AS WELL.
CONFIDENCE TABLE...
17-23Z 23-05Z 05-11Z 11-12Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 91%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...LG
SHORT TERM...PM
LONG TERM...PM
AVIATION...LG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1229 PM EDT WED JUL 15 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE AREA TODAY. FOLLOWING THE
FRONT...SURFACE HIGH PRESSURE WILL DRY OUT THE REGION AS AN UPPER
LEVEL RIDGE BUILDS IN FROM THE WEST...BRINGING WITH IT A RETURN
TO ABOVE NORMAL TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT 1230 PM...CU FIELD A BIT MORE EXTENSIVE THAN PREVIOUS GRIDS.
ESPECIALLY OVER THE PIEDMONT. HENCE...HAVE INCREASED SKY COVER
WITH THIS UPDATE. THIS ALSO IS SLOWING THE TEMP INCREASE...SO
BACKED OFF ON MAX TEMPS BY A COUPLE DEGREES.
AT 1015 AM EDT...NO BIG CHANGES TO THE GOING FORECAST FOR TODAY.
TROUGH/WEAK FRONT ANALYZED FROM CENTRAL NC THROUGH THE UPSTATE INTO
NE GA AT 14Z. 12Z NAM SETTLES THE BOUNDARY SLOWLY SOUTHWARD INTO THE
SC MIDLANDS BY LATE AFTERNOON. THE NAM AND HRRR SHOW ISOLATED
CONVECTION FIRING OVER THE SOUTHERN UPSTATE EARLY THIS AFTERNOON SO
WILL CONTINUE THE ISOLATED POPS THERE. ALSO...THE MODELS SHOW
ISOLATED UPSLOPE SHOWERS ALONG THE TN LINE SO ISOALTED POPS LOOK
GOOD THERE. UPDATED TEMPS/DEWPOINTS WITH LATEST CONSHORT DATA WHICH
BUMPED MAX TEMPS UPWARD A DEGREE OR SO.
630 AM UPDATE...NO MAJOR CHANGES MADE TO THE GRIDS. POPS WERE
TEMPERED DOWN SRN ZONES AS LAST OF VORT PRECIP PUSHES SOUTH. TEMPS
AND TD/S REQUIRED ONLY MINOR TWEAKS WITH SFC WINDS PROVIDING MODEST
MIXING.
AS OF 255 AM EDT WEDNESDAY...AN UPPER LEVEL TROF WILL CONTINUE TO
SWING EAST THROUGH THE DAY WITH THE AXIS PASSING EAST OF THE CWFA BY
16Z/17Z. HEIGHTS WILL BEGIN TO RISE FAIRLY QUICKLY THROUGH THE
AFTERNOON WITH A STRONG H5 HIGH OVER TX NUDGING EAST. LOW LEVEL
MOISTURE SOURCES WILL BE LIMITED...WITH THE BEST POOLING ACROSS THE
MTN SPINE AIDED BY MECH LIFT AND SOME LINGERING MOISTURE SOUTH ALONG
A WEAKENING THETA/E BNDRY FROM CURRENT PRECIP SHIELD ADVANCING
SOUTH. THERE SHOULD BE ENUF LIFT ACROSS THE FAR WRN MTNS FOR
ISOL/SCT -SHRA AND PERHAPS A COUPLE TSTMS. THE SAME GOES FOR THE SRN
ZONES WHERE H5 VORT ENERGY WILL INTERACT WITH THE BNDRY AND PRODUCE
SHORT-LIVED WEAK CONVECTION BEFORE A SUBS INVERSION LIMITS CLOUDS
TO FAIR WX CU MOST LOCALES. WITH DEEP NW/LY FLOW...GOOD MIXING AND
DOWNSLOPE HEATING WILL LOWER SFC TD/S THROUGH THE AFTERNOON.
THUS...THE DAY WILL FEEL A LITTLE DRIER THAN THE PAST FEW DAYS WITH
LOW END GUSTS DEVELOPING BY MID AFTERNOON. THE OVERNIGHT WILL REMAIN
DRY AS THE MLVL FLOW MAINTAINS A N/LY SUBS PATTERN. AT THE SFC... A
RELATIVELY TIGHT PGRAD WILL SLOWLY WEAKEN AS A TROF AXIS SHIFTS
TOWARD THE COAST. SO...WITH SOME WIND AND WEAK SFC-BASED
INVERSIONS...LOWS WILL BE HELD NEAR SEASONAL LEVELS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 230 AM WEDNESDAY...THE 00Z MODEL RUNS SHOW A TREND TOWARD MORE
CONVECTIVE COVERAGE FOR LATE IN THE WEEK...IN SPITE OF THE RETURN OF
THE UPPER RIDGE FROM THE WEST AND THE LACK OF LARGE SCALE FORCING.
THAT BEING SAID...ON THURSDAY AFTERNOON THERE DOES NOT APPEAR TO BE
ANYTHING IN THE MODEL GUIDANCE TO DISCOURAGE DEEP CONVECTION EITHER.
AND...ON A TYPICAL DAY IN THE SUMMERTIME...IT IS DIFFICULT TO KEEP
CONVECTION FROM DEVELOPING ON THE RIDGETOPS GIVEN SUFFICIENT
MOISTURE AND NOTHING THAT ACTS TO PREVENT IT. WILL FOLLOW THE NEW
NAM AND PUT A SMALL PRECIP CHANCE MAINLY OVER THE HIGHEST ELEVATIONS
FOR THE AFTERNOON...AND THEN GET RID OF IT WITH LOSS OF HEATING
THURSDAY EVENING. ON FRIDAY...THE UPPER PATTERN DOES NOT CHANGE
APPRECIABLY WITH THE ANTICYCLONE CENTERED OVER ERN TX/LA...BUT THE
SFC HIGH TO THE NE SEEMS A BIT STRONGER. THE MODELS DEVELOP A WEAK
E/SE FLOW IN THE BOUNDARY LAYER WHICH ADVECTS MOISTURE INTO THE
REGION. THE RESULT IS MORE PRECIP DEVELOPMENT IN THE MODEL. AGAIN...
GIVEN NOTHING TO DISCOURAGE THIS...I EXPECT THERE WILL BE A BIT MORE
COVERAGE THAN PREVIOUSLY EXPECTED...SO PRECIP CHANCES WERE NUDGED
UPWARD A BIT WHICH BRINGS THE PROBABILITY INTO THE CHC RANGE NEAR
THE BLUE RIDGE IN THE AFTERNOON. THE CHANCES FOR ANYTHING BEYOND
GARDEN VARIETY THUNDERSTORMS APPEARS VERY LOW. TEMPS BOTTOM OUT NEAR
NORMAL ON THURSDAY AND THEN BEGIN A CLIMB BACK ABOVE NORMAL STARTING
ON FRIDAY.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 315 AM WEDNESDAY...STILL NO BIG SURPRISES NOTED IN THE LATEST
MEDIUM RANGE GUIDANCE. THE SLOW WESTWARD DRIFT OF THE UPPER
ANTICYCLONE BACK TOWARD THE SRN PLAINS WILL KEEP THE WESTERN
CAROLINAS ON ITS PERIPHERY...AND THUS AWAY FROM ITS SUPPRESSIVE
AFFECTS. THAT SHOULD ALLOW FOR MAINLY DIURNAL SHOWERS AND
THUNDERSTORMS TO DEVELOP EACH DAY GIVEN SUFFICIENT LOW LEVEL
MOISTURE. TEMPS ABOVE NORMAL LOOK LIKE A GOOD BET...BUILDING EACH
DAY TO A PEAK MOST LIKELY ON MONDAY. THE ECMWF SOLUTION SUGGESTS
THAT A SHORT WAVE PASSING TO THE NORTH ON TUESDAY WILL BRING A
WEAKENING COLD FRONT DOWN ACROSS THE AREA THAT WOULD ENHANCE PRECIP
CHANCES AND DROP TEMPS BACK DOWN A BIT. HOWEVER...THE GFS SHOWS THE
UPPER WAVE MUCH FARTHER N AND KEEPS ANY BOUNDARY WELL TO OUR N. WILL
NOT MAKE ANY SIGNIFICANT CHANGES TO THE MEDIUM RANGE AT THIS TIME...
AND THINK EVEN WITHOUT THE FRONT THE COVERAGE OF STORMS WILL
INCREASE A BIT EACH DAY ANYWAY.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...VFR CONDS THROUGH THE TAF PERIOD. THE UPPER TROF AXIS WILL
CROSS EAST OF THE TERMINAL AFT 16Z AND SUPPRESSIVE DYNAMICS WILL
ALLOW ONLY FAIR WX CU THROUGH THE AFTERNOON. NO CIG/VSBY CONCERNS
OVERNIGHT AS WINDS REMAIN UP DUE TO A RELATIVELY TIGHT PGRAD. WINDS
WILL BECOME ALIGNED NW/LY WITH LOW END GUSTS ARND NOON AND THEN N/LY
ARND 00Z AS BROAD SFC TROF PUSHES SOUTHEAST.
ELSEWHERE...VERY SIMILAR TAFS TO KCLT WITH KAVL HAVING THE BEST
POTENTIAL FOR LATE PERIOD VSBY CONCERNS. OTHERWISE...FAIR WX CU WILL
DEVELOP THIS AFTERNOON WITH LOW END GUSTS. GENERALLY A NW/LY DIR ALL
SITES WITH WINDS PERSISTING OVERNIGHT IN A RELATIVELY TIGHT PGRAD.
OUTLOOK...BUILDING UPPER RIDGING WILL PERSIST THROUGH WEEKS END
LEADING TO LOWER PRECIP/RESTRICTION CHANCES. THESE CHANCES WILL
INCREASE OVER THE WEEKEND AS SAID RIDGE RETROGRADES LEADING TO
INCREASING DIURNAL SHRA/TSRA CHANCES AND THUS MORNING FOG/STRATUS AS
WELL.
CONFIDENCE TABLE...
16-22Z 22-04Z 04-10Z 10-12Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 81% HIGH 100% HIGH 100% HIGH 86%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...LG
SHORT TERM...PM
LONG TERM...PM
AVIATION...SBK
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
338 PM CDT WED JUL 15 2015
.SHORT TERM...
.TONIGHT - CONFIDENCE...MEDIUM
INFLUENCE OF DRY AND STABLE HIGH PRESSURE RIDGE WILL LINGER WELL
INTO THE EVENING HOURS WITH ONLY SOME CIRRUS SPILLING ACROSS SRN WI.
LATER IN THE NIGHT PRONOUNCED 850 SOUTHERLY LLJ APPROACHES SW WI
THOUGH AXIS AND BEST MOISTURE PROGGD TO STAY LARGELY WEST OF THE
CWA...HOWEVER INCREASE IN MID LEVEL MOISTURE AND SOME ELEVATED THOUGH
LIMITED INSTABILITY IN PROXIMITY TO THE LLJ SUGGESTS SOME POP PRIOR
TO 12Z SEEMS PRUDENT IN PARTS OF THE WESTERN CWA LATER IN THE NIGHT.
.THURSDAY - CONFIDENCE...MEDIUM
850 LLJ PROGGD TO TRANSLATE EASTWARD INTO SRN WI AND FAVOR A PATTERN
OF SIGNIFICANT MOIST/THERMAL ADVECTION. ISODROSOTHERM ANALYSIS SHOWS
MOIST AXIS NOT FAR AWAY IN MN AND IA. IN ADDITION THE MID LEVELS
SHOW SHORTWAVE ACTIVITY AIDING FURTHER ON ALREADY FAVORABLE VERTICAL
MOTION FIELD PROVIDED BY LLJ. THE GFS IS SUGGESTING AN INITIAL SURGE
IN THE MORNING WITH SECONDARY DEVELOPMENT IN THE AFTERNOON...WHILE
THE NAM/ECMWF IMPLY SHOW ONE MAIN QPF AREA. SHOULD ANY CLEARING TAKE
PLACE WITH A NORTHWARD ADVANCING WARM FRONT INTO SRN WI...THEN SOME
STRONGER CONVECTION IS POSSIBLE PER SWODY2 MARGINAL RISK. HOWEVER
MORNING SOUNDINGS FROM THE GFS/NAM DURING ANY OF THE CONVECTION IN
THAT TIMEFRAME SHOW MINIMAL MID LEVEL LAPSE RATES/ELEVATED CAPE. 925
TEMPS RAMP UP INTO THE LOW TO MID 20S CELSIUS IN THE FAR SOUTH SO IF
THAT WARM SECTOR CAN MAKE GROUND INTO THE CWA WITH SOME
CLEARING...WILL NEED TO BOOST TEMPS A BIT MORE SOUTH OF THE BOUNDARY.
THURSDAY NIGHT AND FRIDAY ...FORECAST CONFIDENCE MEDIUM
KEEPING LIKELY POPS IN THE EVENING WITH MODELS TAKING MOST OF THE
FORCING WITH INITIAL WARM-AIR ADVECTION SURGE WITH THE 500 MB SHORT
WAVE AND SURFACE WAVE TO THE NORTHEAST OF THE AREA BY 06Z FRIDAY.
NAM AND GFS SHOW SOME PCPN WITH LINGERING LOW-LAYER FRONTOGENESIS
ALONG THE SURFACE BAROCLINIC ZONE...WITH THE NAM LAYING THE SURFACE
BAROCLINIC ZONE ACROSS THE NRN FORECAST AREA AND THE GFS A BIT
FARTHER SOUTH. MODELS EITHER KEEP THIS BOUNDARY ACROSS AREA OR LIFT
IT BACK ACROSS SRN WI DURING THE AFTERNOON. THIS WILL KEEP SLIGHT
CHANCE/LOW CHANCE POPS IN MAINLY EASTERN AREAS THROUGH THE DAY.
925 MB TEMPS RISE TO 27-28C...WITH THE 00Z ECMWF AROUND 25C BY 00Z
SATURDAY. THOUGH SOME CHANCE FOR LOWER VALUES IF THERE IS MORE
EXTENSIVE CLOUD COVER IN THE AFTERNOON THAN FORECAST...BLENDED
VALUES AND MOS GUIDANCE IN LINE WITH UPPER 80S TO AROUND 90 WITH SW
WINDS ASSURING EVEN EASTERN AREAS WILL GET INTO THE WARM AIR. HEAT
INDEX VALUES WILL REACH THE 90 TO 95 RANGE.
FRIDAY NIGHT AND SATURDAY...FORECAST CONFIDENCE MEDIUM
DRY INITIALLY WITH SHORT WAVE RIDGING FRIDAY NIGHT...WITH NAM A BIT
FASTER AND STRONGER WITH AN MCV/COMPACT SHORT WAVE APPROACHING THE
AREA FRIDAY NIGHT AND MOVING ACROSS FORECAST AREA SATURDAY. MODEL
VARIANCE WITH LOCATION OF WARM FRONT AND 850 MB BAROCLINIC ZONE
LEADS TO DIFFERING LOCATIONS AND TRACKS OF EXPECTED MCS. WILL HOLD
POPS TO WESTERN AREAS FRIDAY NIGHT AND THEN SPREAD CHANCE POPS
ACROSS FORECAST AREA WITH TROUGH PASSAGE SATURDAY.
925 MB TEMPS IN THE SAME NEIGHBORHOOD AS FRIDAY AND WILL ONLY DROP
HIGHS A DEGREE OR TWO AS RAIN WILL NOT BE AN ALL DAY AFFAIR...THOUGH
TIMING OF CLOUDS AND PCPN COULD KEEP HIGHS EVEN COOLER THAN
FORECAST. HEAT INDEX VALUES AGAIN CLIMB INTO THE MID 90S AWAY FROM
LAKE MICHIGAN...WITH SOME UPPER 90S POSSIBLE.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY...FORECAST
CONFIDENCE MEDIUM.
AREA WILL SEE SHORT WAVE ENERGY LIFTING UP THE LEADING FLANK OF A
POSITIVELY TILTED TROUGH CROSSING THE NORTHERN PLAINS SATURDAY
NIGHT/SUNDAY...REACHING THE WESTERN GREAT LAKES BY MONDAY MORNING.
WARM...MOIST UNSTABLE AIR FLOWING NORTHWARD AHEAD OF THE TROUGH WILL
IMPINGE ON SLOW MOVING SURFACE TROUGH...WITH DIFFERING TIMING...
PLACEMENT AND STRENGTH OF SHORT WAVES LEADING TO VARYING MOVEMENT
AND LOCATION OF THE TROUGH. CONSENSUS SOLUTION BRINGS LIKELY POPS
ACROSS MAINLY THE NORTHERN CWA SATURDAY NIGHT...THEN CHANCE POPS
THROUGH SUNDAY NIGHT AS SURFACE TROUGH SLOWLY TRACKS ACROSS THE
AREA...WITH A SLIGHT CHANCE LINGERING INTO MONDAY MORNING.
TEMPERATURES WILL BE A BIT COOLER SUNDAY BUT STILL HUMID WITH HEAT
INDICES OF UPPER 80S TO LOW 90S.
ECMWF TRIES TO BRUSH SRN CWA WITH PRECIPITATION FROM A THUNDERSTORM
COMPLEX PASSING TO THE SOUTH OVER IL MONDAY NIGHT...BUT WILL KEEP
AREA DRY THROUGH TUESDAY WITH HIGH PRESSURE BUILDING IN AND
TEMPERATURES DROPPING BACK TO NORMAL LEVELS FOR THIS TIME OF YEAR
AND DEW POINTS IN THE LOWER 60S. MOST MODELS TRENDING DRIER TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT SO LATER SHIFTS MAY BE ABLE TO DROP
SLIGHT CHANCE/LOW CHANCE POPS.
&&
.AVIATION/00Z TAFS/...VFR CONDITIONS INTO MUCH OF THE NIGHT WITH
DRY/STABLE INFLUENCE OF SURFACE HIGH. EXPECT AN INCREASE IN MID
LEVEL CLOUDS AS THE NIGHT WEARS ON WITH LATEST RAP SOUNDINGS SHOW
LOW LEVELS REMAINING QUITE DRY. IMPRESSIVE LLJ TAKES AIM AT SRN WI
FOR THURSDAY WITH DECENT THERMAL/MOIST ADVECTION EXPECTED. SO HIGH
POPS LOOK GOOD. SREF MVFR CIG PROBS SHOW GREATEST LIKELIHOOD OF
MVFR/IFR CONDITIONS ACRS NRN WI ON THURSDAY.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TONIGHT/THURSDAY AND AVIATION/MARINE...COLLAR
THURSDAY NIGHT THROUGH WEDNESDAY...REM