Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/19/15
AREA FORECAST DISCUSSION...UPDATED
NWS LITTLE ROCK AR
840 PM CDT TUE AUG 18 2015
.DISCUSSION...
EVENING CONVECTION HAS SETTLED DOWN AND NEXT ROUND OF CONVECTION
WILL BE SEEN OVERNIGHT TO WEDNESDAY...AS UPPER DYNAMICS AND A COLD
FRONT SAG INTO AR. DO EXPECT SOME ISOLATED TO SCATTERED CONVECTION
AHEAD OF THE FRONT DUE TO SHORT WAVE ENERGY...BUT MUCH MORE
CONVECTION WILL BE ASSOCIATED HEAD OF THE COLD...AS THE UPPER TROUGH
ROTATES THROUGH THE REGION. ISOLATED STRONG TO SEVERE STORMS WILL BE
POSSIBLE...MAINLY ON WEDNESDAY. ALTHOUGH...MAIN DYNAMICS ARE
EXPECTED TO REMAIN NORTH OF AR. TONIGHT WILL FINE TUNE POPS BACK A
BIT TO THE NW...LOWER CHANCES SOUTH. LOWS WILL MAINLY TO IN THE 70S.
LATE EVENING UPDATE WILL ONLY FINE TUNE ELEMENTS. (59)
&&
.PREV DISCUSSION... /ISSUED 701 PM CDT TUE AUG 18 2015/
.AVIATION...
MAIN CONCERN FOR THIS TAF PACKAGE IS WHEN CONVECTION WILL ARRIVE
AT ANY GIVEN TERMINAL. TRENDED THIS ISSUANCE TOWARDS RUC DATA
WHICH IS HANDLING CURRENT CONVECTIVE TRENDS NICELY AND SHOWS VERY
LITTLE SHOWER OR THUNDERSTORM ACTIVITY OVERNIGHT...WITH THE MAIN
BATCH OF CONVECTION ALONG THE FRONT AS IT MOVES INTO NW ARKANSAS
JUST BEFORE DAYBREAK...AND SLIDES SOUTHEAST TO CENTRAL TERMINALS
BY MID MORNING. DEEP MOISTURE RETURN AHEAD OF THE FRONT SHOULD
PRODUCE MVFR CIGS ACROSS CENTRAL AND SOUTHERN TERMINALS AROUND 10Z
TONIGHT...WITH PREVAILING SHRA OR TSRA ARRIVING AROUND 15Z AT
KHOT AND MORE TOWARDS 18Z AT KLLQ. STORMS WILL NEAR KHRO AND KBPK
MUCH SOONER AND HAVE VCTS INDICATED AT THOSE SITES BY MIDNIGHT
TONIGHT...WITH PREVAILING -TSRA AFTER 12Z FOR SEVERAL HOURS. POST
FRONTAL -SHRA/-RA WILL LIKELY KEEP CIGS DOWN UP NORTH THROUGH THE
END OF THE PERIOD AND HAVE THAT INDICATED AS WELL.
&&
.PREV DISCUSSION... /ISSUED 314 PM CDT TUE AUG 18 2015/
SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT
UNSETTLED WEATHER IS IN THE FORECAST DURING THE SHORT TERM. A
COLD FRONT WILL PUSH INTO THE STATE FROM THE NORTH LATER TONIGHT
AND WEDNESDAY...AND WILL TRIGGER SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS.
THERE WILL BE HIGH POPS ALONG THE FRONT...WITH WIDESPREAD HALF
INCH TO INCH AND A HALF AMOUNTS THE NEXT COUPLE OF DAYS.
THERE COULD BE SOME SEVERE WEATHER AS THE FRONT GOES THROUGH...
BUT IT SHOULD BE ISOLATED. STRONG/DAMAGING WINDS WILL BE THE
MAIN CONCERN.
CLOUDS/PRECIPITATION WILL KEEP DAYTIME TEMPERATURES DOWN
WEDNESDAY/THURSDAY...WITH BELOW NORMAL READINGS NOTED.
THE FRONT WILL EVENTUALLY STALL...AND WILL MOVE SLOWLY BACK
TO THE NORTH AS THE PERIOD ENDS. THAT WILL KEEP THE PATTERN
UNSETTLED HEADING INTO THE LONG TERM.
LONG TERM...SATURDAY THROUGH TUESDAY
LONG TERM BEGINS WITH PRECIPITATION CHANCES CONTINUING FROM THE
SHORT TERM AS A WAVE MOVES THROUGH THE REGION...KEEPING
PRECIPITATION CHANCES IN THE FORECAST THROUGH THE WEEKEND. FOR THE
BEGINNING OF NEXT WEEK...THE MODELS BEGIN TO DIVERGE A BIT IN THE
SPEED THAT THE MODELS DRIVE A FRONT THROUGH THE REGION. THE GFS
HANGS ON TO PRECIPITATION A BIT LONGER. TOWARDS THE END OF THE LONG
TERM DRY WEATHER RETURNS AS A RIDGE BEGINS TO BUILD BACK INTO THE
REGION.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 90 71 80 61 / 20 70 80 70
CAMDEN AR 95 73 90 69 / 40 30 60 70
HARRISON AR 90 67 72 55 / 40 80 80 50
HOT SPRINGS AR 95 74 84 65 / 40 50 80 70
LITTLE ROCK AR 94 74 85 65 / 40 60 80 70
MONTICELLO AR 94 74 89 70 / 40 30 60 70
MOUNT IDA AR 95 73 83 64 / 40 60 80 70
MOUNTAIN HOME AR 87 69 75 55 / 40 80 80 60
NEWPORT AR 90 72 80 63 / 20 60 80 70
PINE BLUFF AR 94 73 87 67 / 40 40 70 70
RUSSELLVILLE AR 93 72 81 62 / 40 70 80 70
SEARCY AR 92 72 83 63 / 40 60 80 70
STUTTGART AR 92 72 85 66 / 40 50 80 70
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AVIATION...64
AREA FORECAST DISCUSSION...UPDATED
NWS LITTLE ROCK AR
701 PM CDT TUE AUG 18 2015
.DISCUSSION...
UPDATED FOR THE 00Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...
MAIN CONCERN FOR THIS TAF PACKAGE IS WHEN CONVECTION WILL ARRIVE
AT ANY GIVEN TERMINAL. TRENDED THIS ISSUANCE TOWARDS RUC DATA
WHICH IS HANDLING CURRENT CONVECTIVE TRENDS NICELY AND SHOWS VERY
LITTLE SHOWER OR THUNDERSTORM ACTIVITY OVERNIGHT...WITH THE MAIN
BATCH OF CONVECTION ALONG THE FRONT AS IT MOVES INTO NW ARKANSAS
JUST BEFORE DAYBREAK...AND SLIDES SOUTHEAST TO CENTRAL TERMINALS
BY MID MORNING. DEEP MOISTURE RETURN AHEAD OF THE FRONT SHOULD
PRODUCE MVFR CIGS ACROSS CENTRAL AND SOUTHERN TERMINALS AROUND 10Z
TONIGHT...WITH PREVAILING SHRA OR TSRA ARRIVING AROUND 15Z AT
KHOT AND MORE TOWARDS 18Z AT KLLQ. STORMS WILL NEAR KHRO AND KBPK
MUCH SOONER AND HAVE VCTS INDICATED AT THOSE SITES BY MIDNIGHT
TONIGHT...WITH PREVAILING -TSRA AFTER 12Z FOR SEVERAL HOURS. POST
FRONTAL -SHRA/-RA WILL LIKELY KEEP CIGS DOWN UP NORTH THROUGH THE
END OF THE PERIOD AND HAVE THAT INDICATED AS WELL.
&&
.PREV DISCUSSION... /ISSUED 314 PM CDT TUE AUG 18 2015/
SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT
UNSETTLED WEATHER IS IN THE FORECAST DURING THE SHORT TERM. A
COLD FRONT WILL PUSH INTO THE STATE FROM THE NORTH LATER TONIGHT
AND WEDNESDAY...AND WILL TRIGGER SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS.
THERE WILL BE HIGH POPS ALONG THE FRONT...WITH WIDESPREAD HALF
INCH TO INCH AND A HALF AMOUNTS THE NEXT COUPLE OF DAYS.
THERE COULD BE SOME SEVERE WEATHER AS THE FRONT GOES THROUGH...
BUT IT SHOULD BE ISOLATED. STRONG/DAMAGING WINDS WILL BE THE
MAIN CONCERN.
CLOUDS/PRECIPITATION WILL KEEP DAYTIME TEMPERATURES DOWN
WEDNESDAY/THURSDAY...WITH BELOW NORMAL READINGS NOTED.
THE FRONT WILL EVENTUALLY STALL...AND WILL MOVE SLOWLY BACK
TO THE NORTH AS THE PERIOD ENDS. THAT WILL KEEP THE PATTERN
UNSETTLED HEADING INTO THE LONG TERM.
LONG TERM...SATURDAY THROUGH TUESDAY
LONG TERM BEGINS WITH PRECIPITATION CHANCES CONTINUING FROM THE
SHORT TERM AS A WAVE MOVES THROUGH THE REGION...KEEPING
PRECIPITATION CHANCES IN THE FORECAST THROUGH THE WEEKEND. FOR THE
BEGINNING OF NEXT WEEK...THE MODELS BEGIN TO DIVERGE A BIT IN THE
SPEED THAT THE MODELS DRIVE A FRONT THROUGH THE REGION. THE GFS
HANGS ON TO PRECIPITATION A BIT LONGER. TOWARDS THE END OF THE LONG
TERM DRY WEATHER RETURNS AS A RIDGE BEGINS TO BUILD BACK INTO THE
REGION.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 90 71 80 61 / 20 70 80 70
CAMDEN AR 95 73 90 69 / 40 30 60 70
HARRISON AR 90 67 72 55 / 40 80 80 50
HOT SPRINGS AR 95 74 84 65 / 40 50 80 70
LITTLE ROCK AR 94 74 85 65 / 40 60 80 70
MONTICELLO AR 94 74 89 70 / 40 30 60 70
MOUNT IDA AR 95 73 83 64 / 40 60 80 70
MOUNTAIN HOME AR 87 69 75 55 / 40 80 80 60
NEWPORT AR 90 72 80 63 / 20 60 80 70
PINE BLUFF AR 94 73 87 67 / 40 40 70 70
RUSSELLVILLE AR 93 72 81 62 / 40 70 80 70
SEARCY AR 92 72 83 63 / 40 60 80 70
STUTTGART AR 92 72 85 66 / 40 50 80 70
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AVIATION...64
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
402 PM MDT MON AUG 17 2015
.SHORT TERM...(TONIGHT THROUGH TUESDAY NIGHT)
ISSUED AT 327 PM MDT MON AUG 17 2015
.SHORT TERM...(TONIGHT THROUGH TUESDAY NIGHT)
ISSUED AT 136 PM MDT MON AUG 17 2015
COMBINATION OF JET MAXIMA ALOFT AND CONDITIONALLY UNSTABLE
ENVIRONMENT HAS GENERATED SCATTERED STORMS THIS AFTERNOON...PRIMARILY
SOUTH OF US HIGHWAY 40. GIVEN THE SHEAR ENVIRONMENT...SOME CELLS
WILL BE STRONG WITH GUSTY WINDS AND SMALL HAIL. STORM PREDICTION
CENTER PLACED THE ERN FRINGE OF OUR FORECAST AREA IN THE MARGINAL
CATEGORY. CURRENT TRENDS OFFERED BY RADAR AND 1 MIN SATELLITE
IMAGES (FORTUNATE THAT IT EXTENDS OVER THE WESTERN SLOPE TODAY)
SHOW STRENGTHENING STORMS NEAR THE I70 CORRIDOR. WEATHER SPOTTER
BETWEEN GLENWOOD SPRINGS AND CARBONDALE REPORTED ONE HALF INCH
SIZED HAIL. WITH UPSTREAM TROUGH OVER THE NRN ROCKIES APPROACHING
THE CENTRAL ROCKIES...NOT UNREASONABLE THAT STRONGER STORMS
(PERHAPS A SEVERE STORM OR TWO) MAY FORM LATE THIS AFTERNOON. BY
NIGHTFALL...STORMS SHOULD BE DIMINISHING. EXCEPT TRAILING ENERGY
OVER SOUTHWEST COLORADO MAY KEEP THINGS ACTIVE OVER LA PLATA AND
ARCHULETA COUNTY UNTIL MIDNIGHT OR SO.
NORTHEAST UTAH/EXTREME NW COLORADO...DEEP MIXED LAYER ASSOCIATED
WITH THE SURFACE TROUGH RESULTS IN RAPID DRYING. STORMS WILL NOT
BE FAVORED IN THIS REGION AS THE MOIST ENVIRONMENT GETS PUSHED
EASTWARD BY UPSTREAM TROUGH.
TUESDAY AND TUESDAY NIGHT...
COOLER AND MUCH DRIER AIR UNDER NW FLOW OVER THE AREA TUESDAY AND
TUESDAY NIGHT SHOULD RESULT IN MAX TEMPERATURES 5-10 DEGREES F
LOWER THAN TODAY...WITH GREATEST COOLING IN NORTHERN AND CENTRAL
ZONES. ALL MODELS SHOW H7 TEMPERATURES DROPPING 4 TO 8 DEGREES C
LOWER THAN TODAY. MIN TEMPERATURES TUESDAY NIGHT COULD DROP INTO
THE UPPER 30S IN SOME OF THE COLDER HIGH ELEVATION VALLEYS SUCH AS
IN THE GUNNISON AREA. MOSTLY CLEAR SKIES EXPECTED OVER THE AREA...
WITH SOME CLOUD BUILDUPS IN THE AFTERNOON AND EARLY EVENING OVER
THE MOUNTAINS AND ONLY ISOLATED THUNDERSTORMS MAINLY NEAR THE
CONTINENTAL DIVIDE AROUND PEAK HEATING TIME.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 327 PM MDT MON AUG 17 2015
WEDNESDAY THROUGH THURSDAY NIGHT...
DRY NORTHWEST FLOW CONTINUING WEDNESDAY THROUGH THURSDAY NIGHT
...WITH MOSTLY CLEAR SKIES EXPECTED TO PERSIST. MODELS DROPPING
H7 TEMPERATURES ANOTHER COUPLE DEGREES C ON WEDNESDAY WITH MAX
TEMPERATURES GENERALLY 3 DEGREES F LOWER THAN TUESDAY. THEN AS
UPPER TROUGH/LOW TRAVERSING NORTHERN STATES SHIFTS EASTWARD ON
THURSDAY...EXPECT SOME AIRMASS WARMING WITH MAX TEMPERATURES
SEVERAL DEGREES WARMER THURSDAY THAN ON WEDNESDAY.
FRIDAY THROUGH MONDAY...
MODELS INDICATE ANOTHER UPPER TROUGH BRUSHING OUR CWA BEGINNING
FRIDAY AND THEN MOVING TO THE EAST OF OUR AREA SATURDAY NIGHT.
EXPECT AN UPTICK OF MOISTURE INTO OUR AREA DURING THIS PERIOD
...THEN DECREASING SOME SUNDAY AND MONDAY UNDER A VERY WEAK
WESTERLY FLOW ALOFT WITH RESIDUAL MOISTURE UNDER THE INFLUENCE OF
DAYTIME HEATING. AFTER ANOTHER UNSEASONABLY WARM DAY ON FRIDAY...
NOTICEABLY COOLER AIR EXPECTED INTO OUR AREA AGAIN SATURDAY
THROUGH SUNDAY...BEFORE WARMER AIR RETURNS ON MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 327 PM MDT MON AUG 17 2015
SCATTERED -TSRA CONTINUE OVER THE CENTRAL ZONES SOUTH OF THE
/ROAN/FLAT TOP MOUNTAINS. KRIL KASE KEGE COULD SEE CIGS BLO 070
ALONG WITH SMALL HAIL AND ERRATIC WIND GUSTS OF 25-40KTS. AFT 03Z
STORMS BECOME ISOLATED IN COVERAGE WITH ALL STORMS ENDING BY 08Z.
VFR CONDITIONS CONTINUE THROUGH TUESDAY WITH ISOLATED AFTERNOON
-TSRA NEAR THE CONTINENTAL DIVIDE.
&&
.FIRE WEATHER...
ISSUED AT 1145 AM MDT MON AUG 17 2015
DEEP MIXED LAYER WILL RESULT THIS AFTERNOON AS LOWER SURFACE
PRESSURE OVER NW COLORADO DEEPENS. SUSTAINED WINDS OF 15-20 MPH
IS EXPECTED WITH PEAK GUSTS OF 35 MPH IN ADVANCE OF A COLD FRONT.
HIGHER RESOLUTION MODELS INDICATE THAT DEW POINT VALUES WILL DROP
QUICKLY WHEN THE SURFACE WINDS DEVELOP...THIS TREND MAY BE
VERIFYING AS THE KCAG (CRAIG) ASOS OBSERVED THE DEW POINT FALLING
FROM 48F TO 28F WITHIN TWO HOURS. THE HRRR MODEL SHOW VALUES
FALLING INTO THE 20S ACROSS MOFFAT COUNTY (FIRE WEATHER ZONE
200)...WHICH IS BELOW MOS GUIDANCE VALUES. SPLIT THE DIFFERENCE
BETWEEN THE HRRR AND GUIDANCE...THE NET RESULT IS HUMIDITY VALUES
OF 10-15% AFTER 20Z (2 PM). THE WINDS MAY PERSIST THROUGH THE
EARLY EVENING HOURS GIVEN TIGHTENING PRESSURE GRADIENTS. CRITICAL
FIRE WEATHER CONDITIONS MAY PERSIST UNTIL AFTER SUNSET.
&&
$$
SHORT TERM...PF/JRP
LONG TERM...JRP
AVIATION...JOE
FIRE WEATHER...PF
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1145 AM MDT MON AUG 17 2015
.UPDATE...
ISSUED AT 1035 AM MDT MON AUG 17 2015
UPDATED TO INCLUDE SOME SHOWERS AND ISOLATED THUNDERSTORMS IN SOME
LOWER ELEVATION ZONES IN CENTRAL PORTION OF OUR CWA BEGINNING THIS
MORNING...WHICH DEVELOPED EARLIER IN THE DAY THAN PREVIOUSLY
EXPECTED. THIS CONVECTIVE ACTIVITY HAS DEVELOPED IN THE NORTHERN
BOUNDS OF UPPER LEVEL DIFLUENCE.
UPDATE ISSUED AT 750 AM MDT MON AUG 17 2015
SURFACE BOUNDARY THAT CUTS ACROSS THE SRN PORTION OF THE FORECAST
AREA HAS BEEN THE TRIGGER MECHANISM FOR ISOLATED SHOWERS AND
THUNDERSTORMS. THE HRRR MODEL SHOWS ACTIVITY EXPANDING ACROSS THIS
AREA AS THE DAY PROGRESSES...BUT A BIT SLOW HANDLING THE CURRENT
ACTIVITY.
THE OTHER CONCERN IS THE POTENTIAL FOR RED FLAG CONDITIONS ACROSS
NW COLORADO...SPECIFICALLY ZONE 200. RAP13 SHOWING DEEPENING SURFACE
LOW (SUB 1000 MB) FROM RAWLINS TRAILING BACK TO SOUTHEAST UTAH.
UPSTREAM...THERE IS THERMAL GRADIENT THAT SPREADS INTO NW COLORADO
THIS EVENING. THE HRRR MODEL SHOWS SURFACE WINDS 15-20 KTS ACROSS
NW COLORADO THIS AFTERNOON. WITH DEEP MIXED LAYER...EXPECT GUSTY
WINDS TO DEVELOP. FIRST IMPRESSION IS THAT RED FLAG CONDITIONS
WILL BE MET...AT LEAST FOR FIRE WEATHER ZONE 200 AND POSSIBLY 202.
PLAN TO TAKE ANOTHER LOOK AT THIS ONCE 12Z GUIDANCE ARRIVES BEFORE
MAKING A FINAL DECISION.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 357 AM MDT MON AUG 17 2015
DRIER AIR BEGINS TO WORK ACROSS NORTHEAST UTAH AND NORTHWEST
COLORADO THIS AFTERNOON AS A 85 KT UPPER LEVEL JET REMAINS OVERHEAD.
THE BEST MOISTURE IS ALONG THE BOOKCLIFFS AND SOUTH ACROSS SOUTHEAST
UTAH AND SOUTHWEST COLORADO WHERE PRECIPITABLE WATER (PW) VALUES
RANGE FROM 0.75 TO 1.0 INCH. EXPECTING STORMS TO DEVELOP OVER THE
HIGHER TERRAIN BY LATE MORNING/EARLY AFTERNOON ACROSS WEST CENTRAL
AND SOUTHWEST COLORADO WITH STORMS DRIFTING AND IMPACTING VALLEYS BY
MID AFTERNOON THROUGH EARLY EVENING GIVEN SOME DECENT STORM MOTION
FROM WEST TO EAST AT 20 MPH. THERE IS SOME DECENT INSTABILITY AND
SHEAR SO EXPECTING SOME ROTATING STORMS WITH GOOD SUSTAINING
UPDRAFTS SIMILAR TO SUNDAY`S ENVIRONMENT. MAINLY BRIEF HEAVY
RAIN...SMALL HAIL AND GUSTY OUTFLOW WINDS CAN BE EXPECTED WITH
FREQUENT LIGHTNING.
AN UPPER LEVEL LOW PRESSURE TROUGH WILL MOVE THROUGH MONTANA AND
NORTHEAST WYOMING THIS AFTERNOON AND EVENING WITH AN ASSOCIATED COLD
FRONT MOVING THROUGH THIS EVENING. THERE IS A NOTICEABLE WIND SHIFT
FROM WEST TO NORTHWEST AS WELL AS A DECREASE IN PW VALUES BEHIND
THIS FRONT TO 0.25 TO 0.5 INCH RANGE. THE SHORT TERM MODELS ARE IN
PRETTY GOOD AGREEMENT WITH TIMING OF THE FRONT WHICH SHOW THE
FRONT MOVING THROUGH THE AREA THIS EVENING INTO EARLY TUESDAY
MORNING. FOLLOWED NAM12 GUIDANCE FOR TIMING WHICH SHOWS THE FRONT
THROUGH NE UTAH AND NW COLORADO BETWEEN 6 PM AND 9 PM AND THROUGH
SE UTAH AND WEST CENTRAL COLORADO BETWEEN 9 PM AND MIDNIGHT. THE
FRONT WILL BE EXITING THE REST OF THE AREA BY 3 AM. THE MODELS ARE
NOT PERFECT SO THIS TIMING MAY NOT BE EXACT BUT AT THIS TIME...IT
GIVES A GOOD APPROXIMATION.
ANOTHER CONCERN IS THE POTENTIAL FOR FIRE WEATHER CRITERIA TO BE MET
ACROSS NORTHWEST COLORADO LATE THIS AFTERNOON AND EVENING WHERE
DRIER AIR WILL BE IN PLACE. THE TIMING OF THE COLD FRONT IS
CRITICAL FOR WHEN AND IF RED FLAG CRITERIA WILL BE MET...WHICH AT
THIS TIME SEEMS TOO LATE IN THE DAY. FIRE WEATHER CONDITIONS LOOK
TO BE FAIRLY LOCALIZED AND NOT WIDESPREAD ENOUGH FOR A LONG ENOUGH
DURATION TO ISSUE ANY FIRE WEATHER HIGHLITES AT THIS TIME. SEE
FIRE WEATHER DISCUSSION BELOW FOR MORE DETAILS.
SHOWERS AND STORMS WILL END AFTER SUNSET AS THIS FRONT MOVES THROUGH
THE REGION FOR A COOLER AND CLEAR NIGHT. TUESDAY WILL BE MUCH DRIER
WITH LITTLE IN THE WAY OF STORM ACTIVITY EXPECTED. ANOTHER UPPER
LEVEL DISTURBANCE WILL MOVE THROUGH MONTANA AND NE WYOMING
TUESDAY AFTERNOON/EVENING PROVIDING A REINFORCING SHOT OF COOLER
AIR TUESDAY NIGHT. EXPECT COOLER TEMPERATURES ON TUESDAY IN THE
WAKE OF THE COLD FRONT WITH HIGHS A FEW DEGREES BELOW NORMAL.
WINDS WILL BE BREEZY TUESDAY AFTERNOON ESPECIALLY ACROSS SW
COLORADO WHERE LOCALIZED FIRE WEATHER CONDITIONS ARE POSSIBLE.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 357 AM MDT MON AUG 17 2015
MODERATE NORTHWEST FLOW WILL CONTINUE INTO TUE NIGHT AND ANOTHER
SHORTWAVE TROUGH WILL SLIDE JUST EAST OF THE FORECAST AREA. FIRE
WEATHER CONCERNS WILL CONTINUE...ESPECIALLY OVER NW CO...BUT THE
TIGHTEST GRADIENT WILL HOLD OFF UNTIL AFTER MIDNIGHT AND AFTER
THE HUMIDITY WILL HAVE RISEN ABOVE CRITERIA.
WED AND THU...THE GRADIENT RELAXES AS LOW PRESSURE PUSHES TO THE
EAST AND DRY CONDITIONS PREVAIL. ON FRIDAY AND SATURDAY ANOTHER
TROUGH WILL MOVE ACROSS THE NORTHERN TIER STATES. THE GFS AND EC
ARE FINALLY SHOWING SOME AGREEMENT AND RUN TO RUN CONSISTENCY.
BOTH KEEP THE TROUGH CLOSER TO THE U.S. AND CANADIAN BORDER...
THOUGH THE PRESSURE GRADIENT OVER THE FORECAST AREA WILL INCREASE
FRIDAY NIGHT THROUGH SAT EVENING AND SOME MOISTURE WILL BE DRAWN
NORTH FROM AZ AND NM.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1145 AM MDT MON AUG 17 2015
SCATTERED -SHRA/-TSRA CAN BE EXPECTED OVER THE COLORADO WESTERN
SLOPE TODAY. SOME STORMS COULD BE STRONG WITH LOCAL G40KTS AND
5SM +TSRAGS THAT WILL RESULT IN CIGS FALLING BELOW ILS BREAKPOINTS
FOR THE MOUNTAIN TAF SITES. LOWER ELEVATED TAF SITES SUCH AS
KGJT...KRIL...AND KMTJ WILL HAVE LOCALIZED G40KTS FROM THUNDERSTORM
OUTFLOW WINDS IN ADDITION TO BRIEF TSRA.
A COLD FRONT PUSHES INTO NW COLORADO TONIGHT THAT WILL PUSH
THUNDERSTORMS EAST OF THE DIVIDE. IN ADVANCE OF THIS COLD FRONT
THROUGH 03Z THIS EVENING...AREAS G25-30KTS WILL OCCUR OVER NE UTAH
AND NW COLORADO.
NO SIGNIFICANT WEATHER IS EXPECTED AFTER 08Z TONIGHT.
&&
.FIRE WEATHER...
ISSUED AT 1145 AM MDT MON AUG 17 2015
DEEP MIXED LAYER WILL RESULT THIS AFTERNOON AS LOWER SURFACE
PRESSURE OVER NW COLORADO DEVELOPS. SUSTAINED WINDS OF 15-20 MPH
IS EXPECTED WITH PEAK GUSTS OF 35 MPH IN ADVANCE OF A COLD FRONT.
HIGHER RESOLUTION MODELS INDICATE THAT DEW POINT VALUES WILL DROP
QUICKLY WHEN THE SURFACE WINDS DEVELOP. THE HRRR MODEL SHOW VALUES
FALLING INTO THE 20S ACROSS MOFFAT COUNTY (FIRE WEATHER ZONE
200)...WHICH IS BELOW MOS GUIDANCE VALUES. SPLIT THE DIFFERENCE
BETWEEN THE HRRR AND GUIDANCE...THE NET RESULT IS HUMIDITY VALUES
OF 10-15% AFTER 20Z (2 PM). THE WINDS MAY PERSIST THROUGH THE
EARLY EVENING HOURS GIVEN TIGHTENING PRESSURE GRADIENTS. CRITICAL
FIRE WEATHER CONDITIONS MAY PERSIST UNTIL AFTER SUNSET.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR COZ200-202.
UT...NONE.
&&
$$
UPDATE...JRP
SHORT TERM...MDA
LONG TERM...CC
AVIATION...PF
FIRE WEATHER...PF
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1042 AM MDT MON AUG 17 2015
.UPDATE...
ISSUED AT 1035 AM MDT MON AUG 17 2015
UPDATED TO INCLUDE SOME SHOWERS AND ISOLATED THUNDERSTORMS IN SOME
LOWER ELEVATION ZONES IN CENTRAL PORTION OF OUR CWA BEGINNING THIS
MORNING...WHICH DEVELOPED EARLIER IN THE DAY THAN PREVIOUSLY
EXPECTED. THIS CONVECTIVE ACTIVITY HAS DEVELOPED IN THE NORTHERN
BOUNDS OF UPPER LEVEL DIFLUENCE.
UPDATE ISSUED AT 750 AM MDT MON AUG 17 2015
SURFACE BOUNDARY THAT CUTS ACROSS THE SRN PORTION OF THE FORECAST
AREA HAS BEEN THE TRIGGER MECHANISM FOR ISOLATED SHOWERS AND
THUNDERSTORMS. THE HRRR MODEL SHOWS ACTIVITY EXPANDING ACROSS THIS
AREA AS THE DAY PROGRESSES...BUT A BIT SLOW HANDLING THE CURRENT
ACTIVITY.
THE OTHER CONCERN IS THE POTENTIAL FOR RED FLAG CONDITIONS ACROSS
NW COLORADO...SPECIFICALLY ZONE 200. RAP13 SHOWING DEEPENING SURFACE
LOW (SUB 1000 MB) FROM RAWLINS TRAILING BACK TO SOUTHEAST UTAH.
UPSTREAM...THERE IS THERMAL GRADIENT THAT SPREADS INTO NW COLORADO
THIS EVENING. THE HRRR MODEL SHOWS SURFACE WINDS 15-20 KTS ACROSS
NW COLORADO THIS AFTERNOON. WITH DEEP MIXED LAYER...EXPECT GUSTY
WINDS TO DEVELOP. FIRST IMPRESSION IS THAT RED FLAG CONDITIONS
WILL BE MET...AT LEAST FOR FIRE WEATHER ZONE 200 AND POSSIBLY 202.
PLAN TO TAKE ANOTHER LOOK AT THIS ONCE 12Z GUIDANCE ARRIVES BEFORE
MAKING A FINAL DECISION.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 357 AM MDT MON AUG 17 2015
DRIER AIR BEGINS TO WORK ACROSS NORTHEAST UTAH AND NORTHWEST
COLORADO THIS AFTERNOON AS A 85 KT UPPER LEVEL JET REMAINS OVERHEAD.
THE BEST MOISTURE IS ALONG THE BOOKCLIFFS AND SOUTH ACROSS SOUTHEAST
UTAH AND SOUTHWEST COLORADO WHERE PRECIPITABLE WATER (PW) VALUES
RANGE FROM 0.75 TO 1.0 INCH. EXPECTING STORMS TO DEVELOP OVER THE
HIGHER TERRAIN BY LATE MORNING/EARLY AFTERNOON ACROSS WEST CENTRAL
AND SOUTHWEST COLORADO WITH STORMS DRIFTING AND IMPACTING VALLEYS BY
MID AFTERNOON THROUGH EARLY EVENING GIVEN SOME DECENT STORM MOTION
FROM WEST TO EAST AT 20 MPH. THERE IS SOME DECENT INSTABILITY AND
SHEAR SO EXPECTING SOME ROTATING STORMS WITH GOOD SUSTAINING
UPDRAFTS SIMILAR TO SUNDAY`S ENVIRONMENT. MAINLY BRIEF HEAVY
RAIN...SMALL HAIL AND GUSTY OUTFLOW WINDS CAN BE EXPECTED WITH
FREQUENT LIGHTNING.
AN UPPER LEVEL LOW PRESSURE TROUGH WILL MOVE THROUGH MONTANA AND
NORTHEAST WYOMING THIS AFTERNOON AND EVENING WITH AN ASSOCIATED COLD
FRONT MOVING THROUGH THIS EVENING. THERE IS A NOTICEABLE WIND SHIFT
FROM WEST TO NORTHWEST AS WELL AS A DECREASE IN PW VALUES BEHIND
THIS FRONT TO 0.25 TO 0.5 INCH RANGE. THE SHORT TERM MODELS ARE IN
PRETTY GOOD AGREEMENT WITH TIMING OF THE FRONT WHICH SHOW THE
FRONT MOVING THROUGH THE AREA THIS EVENING INTO EARLY TUESDAY
MORNING. FOLLOWED NAM12 GUIDANCE FOR TIMING WHICH SHOWS THE FRONT
THROUGH NE UTAH AND NW COLORADO BETWEEN 6 PM AND 9 PM AND THROUGH
SE UTAH AND WEST CENTRAL COLORADO BETWEEN 9 PM AND MIDNIGHT. THE
FRONT WILL BE EXITING THE REST OF THE AREA BY 3 AM. THE MODELS ARE
NOT PERFECT SO THIS TIMING MAY NOT BE EXACT BUT AT THIS TIME...IT
GIVES A GOOD APPROXIMATION.
ANOTHER CONCERN IS THE POTENTIAL FOR FIRE WEATHER CRITERIA TO BE MET
ACROSS NORTHWEST COLORADO LATE THIS AFTERNOON AND EVENING WHERE
DRIER AIR WILL BE IN PLACE. THE TIMING OF THE COLD FRONT IS
CRITICAL FOR WHEN AND IF RED FLAG CRITERIA WILL BE MET...WHICH AT
THIS TIME SEEMS TOO LATE IN THE DAY. FIRE WEATHER CONDITIONS LOOK
TO BE FAIRLY LOCALIZED AND NOT WIDESPREAD ENOUGH FOR A LONG ENOUGH
DURATION TO ISSUE ANY FIRE WEATHER HIGHLITES AT THIS TIME. SEE
FIRE WEATHER DISCUSSION BELOW FOR MORE DETAILS.
SHOWERS AND STORMS WILL END AFTER SUNSET AS THIS FRONT MOVES THROUGH
THE REGION FOR A COOLER AND CLEAR NIGHT. TUESDAY WILL BE MUCH DRIER
WITH LITTLE IN THE WAY OF STORM ACTIVITY EXPECTED. ANOTHER UPPER
LEVEL DISTURBANCE WILL MOVE THROUGH MONTANA AND NE WYOMING
TUESDAY AFTERNOON/EVENING PROVIDING A REINFORCING SHOT OF COOLER
AIR TUESDAY NIGHT. EXPECT COOLER TEMPERATURES ON TUESDAY IN THE
WAKE OF THE COLD FRONT WITH HIGHS A FEW DEGREES BELOW NORMAL.
WINDS WILL BE BREEZY TUESDAY AFTERNOON ESPECIALLY ACROSS SW
COLORADO WHERE LOCALIZED FIRE WEATHER CONDITIONS ARE POSSIBLE.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 357 AM MDT MON AUG 17 2015
MODERATE NORTHWEST FLOW WILL CONTINUE INTO TUE NIGHT AND ANOTHER
SHORTWAVE TROUGH WILL SLIDE JUST EAST OF THE FORECAST AREA. FIRE
WEATHER CONCERNS WILL CONTINUE...ESPECIALLY OVER NW CO...BUT THE
TIGHTEST GRADIENT WILL HOLD OFF UNTIL AFTER MIDNIGHT AND AFTER
THE HUMIDITY WILL HAVE RISEN ABOVE CRITERIA.
WED AND THU...THE GRADIENT RELAXES AS LOW PRESSURE PUSHES TO THE
EAST AND DRY CONDITIONS PREVAIL. ON FRIDAY AND SATURDAY ANOTHER
TROUGH WILL MOVE ACROSS THE NORTHERN TIER STATES. THE GFS AND EC
ARE FINALLY SHOWING SOME AGREEMENT AND RUN TO RUN CONSISTENCY.
BOTH KEEP THE TROUGH CLOSER TO THE U.S. AND CANADIAN BORDER...
THOUGH THE PRESSURE GRADIENT OVER THE FORECAST AREA WILL INCREASE
FRIDAY NIGHT THROUGH SAT EVENING AND SOME MOISTURE WILL BE DRAWN
NORTH FROM AZ AND NM.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 357 AM MDT MON AUG 17 2015
VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES FOR THE NEXT 24
HOURS. A WEAK COLD FRONT MOVING THROUGH THE AREA THIS MORNING
WILL CAUSE A BAND OF ISOLATED SHOWERS AND THUNDERSTORMS CUTTING
ACROSS CENTRAL AND SOUTHWEST CO. KMTJ AND KTEX SHOULD HAVE VCSH
THROUGH ABOUT 15Z.
FROM 19Z TO ABOUT 04Z ANOTHER WEAK FRONT WILL MOVE ACROSS THE
AREA FROM NW TO SE. ISOLD TO SCATTERED SHOWERS AND THUNDERSTORMS
WILL DEVELOP ALONG WITH GUSTY NORTHWEST WINDS. EXPECT MECHANICAL
TURBULENCE OVER RIDGES.
&&
.FIRE WEATHER...
ISSUED AT 357 AM MDT MON AUG 17 2015
AN UPPER LEVEL DISTURBANCE WILL MOVE THROUGH THE NORTHERN ROCKIES
THIS AFTERNOON AND EVENING WITH A COLD FRONT MOVING THROUGH EASTERN
UTAH AND WESTERN COLORADO DURING THE EVENING HOURS. BREEZY
CONDITIONS WILL EXIST ACROSS NORTHWEST COLORADO DURING THE AFTERNOON
AND EVENING WITH THE BEST WINDS OCCURRING BETWEEN 6 PM AND 9 PM. THE
KEY PIECE HERE IS THE TIMING OF A COLD FRONT WHICH LOOKS TO MOVE
THROUGH NORTHWEST COLORADO BETWEEN 6 PM AND 9 PM THIS EVENING.
LOCALIZED FIRE WEATHER CONDITIONS ARE POSSIBLE DURING THIS TIME BUT
DOES NOT LOOK WIDESPREAD ENOUGH FOR A LONG ENOUGH DURATION TO ISSUE
FIRE WEATHER HIGHLITES. THE FRONTAL TIMING IS A BIT TOO LATE WHEN
THE COMBINATION OF LOW RH AND WINDS TO 25 MPH WILL BE MET. THIS IS
SOMETHING THAT BEARS WATCHING DEPENDING ON THE TIMING OF THE COLD
FRONT. TUESDAY WILL BE DRIER ACROSS THE REGION WITH BREEZY
CONDITIONS POSSIBLE FOR SW COLORADO WHICH ALSO BEARS WATCHING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 9 PM MDT THIS
EVENING FOR COZ200-202.
UT...NONE.
&&
$$
UPDATE...JRP
SHORT TERM...MDA
LONG TERM...CC
AVIATION...CC
FIRE WEATHER...MDA
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
750 AM MDT MON AUG 17 2015
.UPDATE...
ISSUED AT 750 AM MDT MON AUG 17 2015
SURFACE BOUNDARY THAT CUTS ACROSS THE SRN PORTION OF THE FORECAST
AREA HAS BEEN THE TRIGGER MECHANISM FOR ISOLATED SHOWERS AND
THUNDERSTORMS. THE HRRR MODEL SHOWS ACTIVITY EXPANDING ACROSS THIS
AREA AS THE DAY PROGRESSES...BUT A BIT SLOW HANDLING THE CURRENT
ACTIVITY.
THE OTHER CONCERN IS THE POTENTIAL FOR RED FLAG CONDITIONS ACROSS
NW COLORADO...SPECIFICALLY ZONE 200. RAP13 SHOWING DEEPENING SURFACE
LOW (SUB 1000 MB) FROM RAWLINS TRAILING BACK TO SOUTHEAST UTAH.
UPSTREAM...THERE IS THERMAL GRADIENT THAT SPREADS INTO NW COLORADO
THIS EVENING. THE HRRR MODEL SHOWS SURFACE WINDS 15-20 KTS ACROSS
NW COLORADO THIS AFTERNOON. WITH DEEP MIXED LAYER...EXPECT GUSTY
WINDS TO DEVELOP. FIRST IMPRESSION IS THAT RED FLAG CONDITIONS
WILL BE MET...AT LEAST FOR FIRE WEATHER ZONE 200 AND POSSIBLY 202.
PLAN TO TAKE ANOTHER LOOK AT THIS ONCE 12Z GUIDANCE ARRIVES BEFORE
MAKING A FINAL DECISION.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 357 AM MDT MON AUG 17 2015
DRIER AIR BEGINS TO WORK ACROSS NORTHEAST UTAH AND NORTHWEST
COLORADO THIS AFTERNOON AS A 85 KT UPPER LEVEL JET REMAINS OVERHEAD.
THE BEST MOISTURE IS ALONG THE BOOKCLIFFS AND SOUTH ACROSS SOUTHEAST
UTAH AND SOUTHWEST COLORADO WHERE PRECIPITABLE WATER (PW) VALUES
RANGE FROM 0.75 TO 1.0 INCH. EXPECTING STORMS TO DEVELOP OVER THE
HIGHER TERRAIN BY LATE MORNING/EARLY AFTERNOON ACROSS WEST CENTRAL
AND SOUTHWEST COLORADO WITH STORMS DRIFTING AND IMPACTING VALLEYS BY
MID AFTERNOON THROUGH EARLY EVENING GIVEN SOME DECENT STORM MOTION
FROM WEST TO EAST AT 20 MPH. THERE IS SOME DECENT INSTABILITY AND
SHEAR SO EXPECTING SOME ROTATING STORMS WITH GOOD SUSTAINING
UPDRAFTS SIMILAR TO SUNDAY`S ENVIRONMENT. MAINLY BRIEF HEAVY
RAIN...SMALL HAIL AND GUSTY OUTFLOW WINDS CAN BE EXPECTED WITH
FREQUENT LIGHTNING.
AN UPPER LEVEL LOW PRESSURE TROUGH WILL MOVE THROUGH MONTANA AND
NORTHEAST WYOMING THIS AFTERNOON AND EVENING WITH AN ASSOCIATED COLD
FRONT MOVING THROUGH THIS EVENING. THERE IS A NOTICEABLE WIND SHIFT
FROM WEST TO NORTHWEST AS WELL AS A DECREASE IN PW VALUES BEHIND
THIS FRONT TO 0.25 TO 0.5 INCH RANGE. THE SHORT TERM MODELS ARE IN
PRETTY GOOD AGREEMENT WITH TIMING OF THE FRONT WHICH SHOW THE
FRONT MOVING THROUGH THE AREA THIS EVENING INTO EARLY TUESDAY
MORNING. FOLLOWED NAM12 GUIDANCE FOR TIMING WHICH SHOWS THE FRONT
THROUGH NE UTAH AND NW COLORADO BETWEEN 6 PM AND 9 PM AND THROUGH
SE UTAH AND WEST CENTRAL COLORADO BETWEEN 9 PM AND MIDNIGHT. THE
FRONT WILL BE EXITING THE REST OF THE AREA BY 3 AM. THE MODELS ARE
NOT PERFECT SO THIS TIMING MAY NOT BE EXACT BUT AT THIS TIME...IT
GIVES A GOOD APPROXIMATION.
ANOTHER CONCERN IS THE POTENTIAL FOR FIRE WEATHER CRITERIA TO BE MET
ACROSS NORTHWEST COLORADO LATE THIS AFTERNOON AND EVENING WHERE
DRIER AIR WILL BE IN PLACE. THE TIMING OF THE COLD FRONT IS
CRITICAL FOR WHEN AND IF RED FLAG CRITERIA WILL BE MET...WHICH AT
THIS TIME SEEMS TOO LATE IN THE DAY. FIRE WEATHER CONDITIONS LOOK
TO BE FAIRLY LOCALIZED AND NOT WIDESPREAD ENOUGH FOR A LONG ENOUGH
DURATION TO ISSUE ANY FIRE WEATHER HIGHLITES AT THIS TIME. SEE
FIRE WEATHER DISCUSSION BELOW FOR MORE DETAILS.
SHOWERS AND STORMS WILL END AFTER SUNSET AS THIS FRONT MOVES THROUGH
THE REGION FOR A COOLER AND CLEAR NIGHT. TUESDAY WILL BE MUCH DRIER
WITH LITTLE IN THE WAY OF STORM ACTIVITY EXPECTED. ANOTHER UPPER
LEVEL DISTURBANCE WILL MOVE THROUGH MONTANA AND NE WYOMING
TUESDAY AFTERNOON/EVENING PROVIDING A REINFORCING SHOT OF COOLER
AIR TUESDAY NIGHT. EXPECT COOLER TEMPERATURES ON TUESDAY IN THE
WAKE OF THE COLD FRONT WITH HIGHS A FEW DEGREES BELOW NORMAL.
WINDS WILL BE BREEZY TUESDAY AFTERNOON ESPECIALLY ACROSS SW
COLORADO WHERE LOCALIZED FIRE WEATHER CONDITIONS ARE POSSIBLE.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 357 AM MDT MON AUG 17 2015
MODERATE NORTHWEST FLOW WILL CONTINUE INTO TUE NIGHT AND ANOTHER
SHORTWAVE TROUGH WILL SLIDE JUST EAST OF THE FORECAST AREA. FIRE
WEATHER CONCERNS WILL CONTINUE...ESPECIALLY OVER NW CO...BUT THE
TIGHTEST GRADIENT WILL HOLD OFF UNTIL AFTER MIDNIGHT AND AFTER
THE HUMIDITY WILL HAVE RISEN ABOVE CRITERIA.
WED AND THU...THE GRADIENT RELAXES AS LOW PRESSURE PUSHES TO THE
EAST AND DRY CONDITIONS PREVAIL. ON FRIDAY AND SATURDAY ANOTHER
TROUGH WILL MOVE ACROSS THE NORTHERN TIER STATES. THE GFS AND EC
ARE FINALLY SHOWING SOME AGREEMENT AND RUN TO RUN CONSISTENCY.
BOTH KEEP THE TROUGH CLOSER TO THE U.S. AND CANADIAN BORDER...
THOUGH THE PRESSURE GRADIENT OVER THE FORECAST AREA WILL INCREASE
FRIDAY NIGHT THROUGH SAT EVENING AND SOME MOISTURE WILL BE DRAWN
NORTH FROM AZ AND NM.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 357 AM MDT MON AUG 17 2015
VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES FOR THE NEXT 24
HOURS. A WEAK COLD FRONT MOVING THROUGH THE AREA THIS MORNING
WILL CAUSE A BAND OF ISOLATED SHOWERS AND THUNDERSTORMS CUTTING
ACROSS CENTRAL AND SOUTHWEST CO. KMTJ AND KTEX SHOULD HAVE VCSH
THROUGH ABOUT 15Z.
FROM 19Z TO ABOUT 04Z ANOTHER WEAK FRONT WILL MOVE ACROSS THE
AREA FROM NW TO SE. ISOLD TO SCATTERED SHOWERS AND THUNDERSTORMS
WILL DEVELOP ALONG WITH GUSTY NORTHWEST WINDS. EXPECT MECHANICAL
TURBULENCE OVER RIDGES.
&&
.FIRE WEATHER...
ISSUED AT 357 AM MDT MON AUG 17 2015
AN UPPER LEVEL DISTURBANCE WILL MOVE THROUGH THE NORTHERN ROCKIES
THIS AFTERNOON AND EVENING WITH A COLD FRONT MOVING THROUGH EASTERN
UTAH AND WESTERN COLORADO DURING THE EVENING HOURS. BREEZY
CONDITIONS WILL EXIST ACROSS NORTHWEST COLORADO DURING THE AFTERNOON
AND EVENING WITH THE BEST WINDS OCCURRING BETWEEN 6 PM AND 9 PM. THE
KEY PIECE HERE IS THE TIMING OF A COLD FRONT WHICH LOOKS TO MOVE
THROUGH NORTHWEST COLORADO BETWEEN 6 PM AND 9 PM THIS EVENING.
LOCALIZED FIRE WEATHER CONDITIONS ARE POSSIBLE DURING THIS TIME BUT
DOES NOT LOOK WIDESPREAD ENOUGH FOR A LONG ENOUGH DURATION TO ISSUE
FIRE WEATHER HIGHLITES. THE FRONTAL TIMING IS A BIT TOO LATE WHEN
THE COMBINATION OF LOW RH AND WINDS TO 25 MPH WILL BE MET. THIS IS
SOMETHING THAT BEARS WATCHING DEPENDING ON THE TIMING OF THE COLD
FRONT. TUESDAY WILL BE DRIER ACROSS THE REGION WITH BREEZY
CONDITIONS POSSIBLE FOR SW COLORADO WHICH ALSO BEARS WATCHING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...PF
SHORT TERM...MDA
LONG TERM...CC
AVIATION...CC
FIRE WEATHER...MDA
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1045 AM EDT MON AUG 17 2015
.DISCUSSION...
MORNING CAPE SOUNDING SHOWS A SLIGHTLY DRIER AIRMASS BUT PWATS
REMAIN A MOIST 1.97 INCHES THROUGH THE COLUMN. HOWEVER...THERE IS A
DRY LAYER AT 850 MB WHICH IS LIMITING SHOWER ACTIVITY OVER THE ATLC
AND SHOULD DELAY SLIGHTLY CONVECTIVE DEVELOPMENT OVER LAND. A FEW
ATLC SHOWERS PUSHED ONSHORE MARTIN COUNTY EARLIER THIS MORNING BUT
THESE HAVE DIMINISHED. WITH THE LOW LEVEL RIDGE AXIS TO OUR NORTH...
THE EAST COAST SEA BREEZE WILL DEVELOP EARLY AND PUSH INLAND
STEADILY. THE SUBSIDENCE BEHIND THE SEA BREEZE SHOULD SUPPRESS
ADDITIONAL SHOWERS FROM PUSHING ONSHORE SO RAIN CHANCES APPEAR
LOWEST ALONG THE COAST GOING FORWARD. HAVE LOWERED POPS OVER THE
ATLC AND COAST SLIGHTLY TO 25 PERCENT. WILL KEEP A LITTLE HIGHER
RAIN CHANCE ALONG THE VOLUSIA COAST WHERE RAP ANALYSIS SHOWS VORT
MAX PUSHING OFF THE COAST AND VIS SATELLITE IMAGERY SHOWING A TWIST
TO THE MID LEVEL CLOUD PATTERN. EXPECT ISOLATED TO SCATTERED
SHOWERS/STORMS TO DEVELOP INLAND FROM THE COAST AND INCREASING IN
COVERAGE OVER THE INTERIOR ESP NORTH AND WEST OF ORLANDO. THE SEA
BREEZE COLLISION SHOULD OCCUR JUST WEST OF LAKE COUNTY EARLY THIS
EVENING SO WILL KEEP SCATTERED SHOWERS WEST OF ORLANDO PAST SUNSET.
&&
.AVIATION...VFR MAY GIVE WAY TO LCL-AREAS MVFR CIGS BKN020-025 AFTER
15Z IN DIURNAL CU BUT DRY AIR SEEN AT 5K FT FROM WEATHER BALLOON MAY
LIMIT SPATIAL COVERAGE. ISOLD SHRA/TS INLAND FROM THE COAST 15Z-18Z
AS ECSB DEVELOPS. ACTIVITY CONCENTRATES OVER THE INLAND TERMINALS
20Z-24Z...WITH SPOTTY ACTIVITY TIL AROUND 02Z ESP LEE.
&&
.MARINE... NO SIGNIFICANT CHANGES TO CURRENT COASTAL WATERS FCST.
TODAY/TONIGHT...RIDGE AXIS NORTH OF THE WATERS WILL GENERATE A
GENTLE E-SE BREEZE AROUND 10 KNOTS THROUGH TONIGHT WITH SEAS A
LITTLE EITHER SIDE OF 2 FEET.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 90 75 90 76 / 50 20 40 20
MCO 92 75 93 76 / 60 20 60 30
MLB 90 76 90 78 / 30 20 40 20
VRB 90 75 90 76 / 30 20 40 30
LEE 91 76 94 78 / 60 30 60 30
SFB 92 75 93 76 / 60 20 50 30
ORL 92 76 93 77 / 60 20 60 30
FPR 90 75 90 76 / 30 20 40 30
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
KELLY/BRAGAW
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
1020 PM EDT TUE AUG 18 2015
.UPDATE...
THUNDER KEEPS DIMINISHING ACROSS THE CWFA THIS EVENING. HAVE
TWEAKED POPS ACCORDING TO THE LATEST RADAR TRENDS. THE HRRR KEEPS
ONLY A FEW SHOWERS AROUND OVERNIGHT...SO HAVE LOWERED POPS A BIT.
MODELS ARE A LITTLE SLOWER STARTING THE PRECIP TOMORROW...SO
DELAYED THE ONSET OF THE LIKELY POPS.
&&
.PREV DISCUSSION... /ISSUED 738 PM EDT TUE AUG 18 2015/
PREV DISCUSSION... /ISSUED 343 PM EDT TUE AUG 18 2015/
SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
NO MAJOR CHANGES IN THE OVERALL WET PATTERN IS EXPECTED AS AN ACTIVE
SOUTHWEST FLOW ALOFT CONTINUES TO INTERACT WITH VERY MOIST AND
MODERATELY UNSTABLE ENVIRONMENT TO PRODUCE SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS... MAINLY DURING DAYTIME HEATING BETWEEN
NOON AND 10 PM... WITH MAINLY ISOLATED TO SCATTERED SHOWERS
LINGERING OVERNIGHT.
ALTHOUGH MOST STORMS WILL REMAIN WELL UNDER SEVERE LIMITS... AN
ISOLATED STRONG TO SEVERE STORM CANNOT BE RULED OUT DURING THE LATE
AFTERNOON AND EARLY EVENING HOURS TODAY... AND AGAIN ON WEDNESDAY
AS CAPE VALUES CLIMB INTO THE 2500-3000 J/KG RANGE.
THE GREATER CONVECTIVE CONCERN IS THE POTENTIAL FOR BRIEF FLOODING
AS ENTRENCHED DEEP TROPICAL MOISTURE SUPPORTS LOCALLY HEAVY
DOWNPOURS... EVEN FROM SHOWERS... THAT CAN QUICKLY DUMP 1-3 INCHES
IN A SHORT PERIOD OF TIME. WILL NEED TO MONITOR ANY FLASHY... FLOOD
PRONE CREEKS CLOSELY OVER THE NEXT COUPLE OF DAYS OR MORE.
OTHERWISE... WILL LEAN TOWARD PERSISTENCE FOR TEMPS AS AMPLE LOWS
CLOUDS TONIGHT AND WEDNESDAY NIGHT HOLD LOWS IN THE 70S... AND
WIDESPREAD CONVECTION HELP HOLD HIGHS ON WEDNESDAY MOSTLY IN THE
80S... EXCEPT SOME LOWER 90S IN THE FAR SOUTHERN REACHES.
39
LONG TERM /THURSDAY THROUGH TUESDAY/...
NO MAJOR CHANGES MADE TO THE FORECAST PERIOD AS THE LONG TERM
SOLUTIONS IN DECENT AGREEMENT EXCEPT FOR LATE IN THE PERIOD. GFS
HAS LOWER AMPLITUDE UPPER TROUGH DYNAMICS BY EARLY NEXT WEEK AND
THUS STRUGGLES TO PUSH A FRONT THROUGH BUT HAVE LEANED MORE TOWARD
PREVIOUS FORECAST AND EARLIER ECMWF TO KEEP CONSISTENCY. OTHERWISE
HAVE REFRESHED OTHER FIELDS WITH LATEST BLEND. PREVIOUS DISCUSSION
FOLLOWS...
BAKER
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
PATTERN IN LONG TERM PERIOD TRANSITIONS FROM HIGH AMPLITUDE TROUGH
ALONG THE MS RIVER VALLEY STATES ON WED TO ZONAL FLOW THIS WEEKEND
AND FINALLY WEAK NW FLOW/UPR RIDGE TO THE WEST WITH A HINT OF A
MDT FROPA ON MONDAY. WITH THE FIRST TWO PATTERNS...SE CONUS SHOULD
REMAIN IN MOIST PATTERN WITH DEEP MOISTURE THRU THE WEEKEND. NO
ONE DAY SEEMS TO STAND OUT WITH PRECIP CHCS NOR DO ANY DAYS SEEM
TO HAVE CHC FOR SVR OR EVEN STRONG DEEP CONVECTION. MED RANGE
MODELS IN GOOD AGREEMENT. WPC PREFERRING BLEND OF ALL 00Z
OPERATIONAL MODELS FOR FEATURES AFFECTING CWA THRU DAY 7.
TROPICAL ACTIVITY REMAINS SUBDUED. COLD CORE UPPER LOW OFF
CAROLINA COAST...WHICH HAS PLAYED A ROLE IN CREATING STAGNANT
PATTERN OF LATE AND MAY BECOME TROPICAL IN NATURE...SHOULD GET
PICKED UP BY UPPER TROUGH THIS WEEKEND AND LIFT AWAY FROM EAST
COAST. LOW LATITUDE DISTURBANCE AT 35W LONGITUDE THAT TPC IS
TRACKING COULD DEVELOP INTO A NAMED STORM BUT PROGGED TO REMAIN ON
WESTERLY COURSE WITH MEAGER INTENSITY BY ECMWF AND GFS. BY NO
MEANS A GUARANTEE BUT THATS THE LATEST 411.
SNELSON
AVIATION...
00Z UPDATE...
LINE OF SHRA/TSRA SHOULD START EXITING WITHIN THE HOUR. HI-RES
MODELS ARE NOT INDICATING MUCH IN THE WAY OF PRECIP FOR THE
OVERNIGHT HOURS...SO LEFT MENTION OUT. HOWEVER...MVFR/IFR CIGS
WILL ONCE AGAIN BE POSSIBLE OVERNIGHT AFTER 06Z. THE LOW CLOUDS
SHOULD BEGIN TO BREAK A COUPLE HOURS AFTER SUNRISE...BUT SHOULD BE
BKN VFR FOR MUCH OF THE DAY.
//ATL CONFIDENCE...00Z UPDATE...
MED CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 72 89 73 89 / 70 70 50 60
ATLANTA 73 87 73 87 / 70 70 50 70
BLAIRSVILLE 67 81 68 80 / 80 80 60 70
CARTERSVILLE 70 87 72 86 / 80 80 60 70
COLUMBUS 74 89 74 90 / 70 70 40 60
GAINESVILLE 71 85 72 85 / 70 70 50 70
MACON 73 91 74 91 / 70 70 40 50
ROME 71 86 72 85 / 80 80 60 70
PEACHTREE CITY 72 88 72 88 / 70 70 50 70
VIDALIA 74 91 75 92 / 60 70 30 50
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...
AVIATION...
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
734 PM EDT TUE AUG 18 2015
.SYNOPSIS...
A MOIST FLOW CIRCULATING AROUND OFFSHORE HIGH PRESSURE WILL
PERSIST THROUGH MUCH OF THE WEEK. SCATTERED TO NUMEROUS SHOWERS
AND THUNDERSTORMS WILL OCCUR.
&&
.NEAR TERM /UNTIL 7 AM WEDNESDAY MORNING/...
THE SOUTHERLY FLOW CIRCULATING AROUND OFFSHORE HIGH PRESSURE HAS
RESULTED IN HIGH MOISTURE IN THE FORECAST AREA. PRECIPITABLE
WATER HAS INCREASED TO JUST OVER 2 INCHES. THE MOISTURE AND
HEATING HAS HELPED CAUSE SCATTERED SHOWERS AND THUNDERSTORMS. WEAK
LIFT AHEAD OF A WEAK MID-LEVEL SHORTWAVE TROUGH MAY RESULT IN MORE
WIDESPREAD COVERAGE LATER THIS EVENING. THE HRRR SHOWED
CONSIDERABLE COVERAGE ESPECIALLY IN THE CSRA AND SOUTH MIDLANDS
DURING THE 800 PM TO 1000 PM TIME FRAME. BELIEVE CLOUDINESS AND
SHOWERS WILL CONTINUE TO LIMIT INSTABILITY. THE SEVERE
THUNDERSTORM CHANCE IS LOW. SOME OF THE THUNDERSTORMS WILL HAVE
HEAVY DOWNPOURS BECAUSE OF THE HIGH PRECIPITABLE WATER. A STORM
MOTION NEAR 15 KNOTS SHOULD HELP KEEP RAIN FROM BECOMING EXCESSIVE
UNLESS TRAINING HAPPENS TO DEVELOP. CLOUDINESS FAVORS THE WARMER
TEMPERATURE GUIDANCE TONIGHT. FORECASTED LOWS MAINLY IN THE MIDDLE
70S.
&&
.SHORT TERM /7 AM WEDNESDAY MORNING THROUGH THURSDAY/...
A MOIST LOW-LEVEL SOUTHERLY FLOW CIRCULATING AROUND OFFSHORE
HIGH PRESSURE AND A SERIES OF MID-LEVEL SHORTWAVE TROUGHS IN A
FLAT FLOW WILL KEEP A THREAT OF SHOWERS AND THUNDERSTORMS ACROSS
THE REGION. PRECIPITABLE WATER WILL REMAIN HIGH WITH VALUES MAINLY
JUST ABOVE 2 INCHES. HEAVY DOWNPOURS MAY OCCUR WITH SOME OF THE
THUNDERSTORMS. USED THE GUIDANCE CONSENSUS FOR THE HIGH
TEMPERATURE FORECAST. USED THE WARMER LOW TEMPERATURE GUIDANCE
BECAUSE OF THE HIGH MOISTURE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THE GFS AND ECMWF DISPLAY A DIFFUSE FRONT STALLED NEAR THE
FORECAST AREA EARLY IN THE MEDIUM-RANGE PERIOD. THE MODELS DISPLAY
ANOTHER FRONT LATE IN THE PERIOD. THE MODELS HAVE UPPER RIDGING
FRIDAY AND SATURDAY...WITH TROUGHING DURING THE REST OF THE
PERIOD. THE PATTERN SUPPORTS A CONTINUED CHANCE OF SHOWERS AND
THUNDERSTORMS. THE GFS ENSEMBLE MEAN PLUS GFS...ECMWF...AND EKD
MOS SUPPORT POPS OF MAINLY 20 TO 30 PERCENT. ABOVE NORMAL HIGH
TEMPERATURES SHOULD BE ASSOCIATED WITH THE UPPER RIDGING EARLY IN
THE PERIOD. THE REST OF THE PERIOD WILL LIKELY HAVE NEAR NORMAL
TEMPERATURES.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
SCATTERED SHOWERS CONTINUE TO DEVELOP AND MOVE ACROSS THE FORECAST
AREA. ACTIVITY HAS IMPACTED TAF SITES THIS EVENING...AND HAS PUT
DOWN NUMEROUS OUTFLOW BOUNDARIES. ADDITIONAL SHORTWAVE MOVING INTO
THE REGION FROM CENTRAL GA WILL HELP TO KEEP SOME ACTIVITY ACROSS
THE AREA FOR THE NEXT FEW HOURS...BEFORE BEGINNING TO DIMINISH.
HAVE CONTINUE WITH VCSH AT ALL SITES DUE TO THE NEARNESS OF
SHOWERS...AND WILL INCLUDE A TEMPO GROUP FROM THROUGH 02Z TO ACCOUNT
FOR ANY ADDITIONAL ACTIVITY AND DEVELOPMENT. SKY CONDITIONS ARE
EXPECTED TO REMAIN VFR EVEN IN SHOWERS. VISIBILITIES MAY BRIEFLY
DROP INTO MVFR IN HEAVIER RAINFALL AREAS...BEFORE RETURNING TO VFR
OUTSIDE OF ACTIVITY. WINDS GENERALLY VARIABLE DUE TO BOUNDARIES
ACROSS THE AREA. MODELS DO HINT AT SOME ENHANCED MOISTURE IN LOW-
LEVELS LATE TONIGHT...BUT DO NOT EXPECT ANY WIDESPREAD FOG DUE TO
AN OVERNIGHT LOW-LEVEL JET AND EXPECTED CLOUDS. CONFIDENCE REMAINS
LOW...BUT DID MENTION MVFR BR AT AGS/OGB TOWARDS MORNING.
ADDITIONAL SHOWERS SHOULD ONCE AGAIN FORM WEDNESDAY
AFTERNOON...WHICH MAY BRING BRIEF RESTRICTIONS TO VISIBILITY AT
ALL TAF SITES.
EXTENDED AVIATION OUTLOOK...A MOIST SOUTHERLY FLOW WILL CONTINUE
THROUGH THURSDAY. THERE WILL BE SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS. STRATUS AND FOG MAY OCCUR DURING THE EARLY MORNING
HOURS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
121 AM EDT MON AUG 17 2015
.PREV DISCUSSION... /ISSUED 726 PM EDT SUN AUG 16 2015/
UPDATE...
MADE A FEW CHANGES TO THE FORECAST...MAINLY TO POPS FOR OVERNIGHT
INTO TOMORROW. THE NAM SHOWS A WEAK WAVE MOVING THROUGH
TONIGHT...AND THE HRRR DOES DEVELOP SOME SHOWERS WITH THIS
FEATURE. CURRENTLY...THE BEST TIMING FOR THESE SHOWERS LOOKS TO BE
RIGHT BEFORE DAWN. NOT TOO CONFIDENT ON THE COVERAGE...SO KEPT
POPS CAPPED AROUND 30-40 PERCENT. ALSO TWEAKED THE TIMING FOR THE
AFTERNOON SHRA/TSRA FOR TOMORROW AFTERNOON.
PREV DISCUSSION... /ISSUED 335 PM EDT SUN AUG 16 2015/
SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
AIRMASS IS MODIFYING WITH A MORNING SOUNDING SHOWING 1.5 PWS AND
OVER 3500 MUCAPE... ALL WITH NO CAP. THE GREATER AFTERNOON STORM
CHANCES WILL BE ACROSS FAR NORTH GA WHERE AN UPPER TROUGH IS NEARER
TO NW GA AND OROGRAPHIC LIFT WILL ENHANCE CONVECTION IN THE
MOUNTAINS... AND ACROSS CENTRAL GA WHERE DEEP ATLANTIC MOISTURE IS
ON THE INCREASE. REGIONAL RADARS ARE SHOWING SCATTERED TO NUMEROUS
SHOWERS WITH SOME EMBEDDED THUNDERSTORMS ALREADY DEVELOPING ACROSS
CENTRAL GA... MAINLY ALONG AND SOUTH OF A FRANKLIN TO LOUISVILLE
LINE AND DRIFTING NORTHWARD. AIRMASS WOULD SUPPORT DEVELOPMENT JUST
ABOUT ANYWHERE... SO HAVE INCREASED POPS THROUGH THE EVENING FOR
MOST AREAS... WITH LIKELY POPS ACROSS MUCH OF CENTRAL GA. ALTHOUGH
STORMS ARE EXPECTED TO REMAIN BELOW SEVERE LIMITS WITH LITTLE SHEAR
OR FORCING NOTED... CANNOT RULE OUT A FEW STRONG STORMS BETWEEN 4-9
PM TODAY. THE THUNDERSTORM THREAT SHOULD END BY 9 PM THIS EVENING...
BUT ISOLATED TO POSSIBLY SCATTERED SHOWERS COULD LINGER OVERNIGHT.
THIS IS LARGELY DUE TO AN UPPER TROUGH ALONG THE MS VALLEY REGION
THAT WILL BEGIN TO DRIFT EASTWARD TONIGHT... AND PROVIDE AN SUPPORT
FOR INCREASING RAIN CHANCES FROM THE WEST BEGINNING MONDAY
MORNING... THEN BECOMING SCATTERED TO NUMEROUS IN COVERAGE FOR MOST
AREAS BY MID MONDAY AFTERNOON. NOT EXPECTING SEVERE STORMS ON
MONDAY... BUT A FEW STORMS COULD BE STRONG MONDAY AFTERNOON WITH
WIND GUSTS TO 45 MPH AND FREQUENT LIGHTNING BEING THE MAIN THREATS.
HIGH PWS WOULD ALSO SUPPORT LOCALLY HEAVY RAIN AND BRIEF PONDING OF
WATER IS LIKELY ACROSS LOW LYING AREAS. SCATTERED CONVECTION IS
EXPECTED TO CONTINUE ACROSS THE AREA MONDAY NIGHT... BUT MOSTLY IN
THE FORM OF SHOWERS.
ALTHOUGH A FEW SHOWERS WILL BE POSSIBLY TONIGHT... EXPECTING LOW
CLOUDS AND PATCHY FOG TO DEVELOP ACROSS CENTRAL GA AND SPREAD
NORTHWARD TOWARD MONDAY MORNING. THIS WILL HELP HOLD TEMPS AND
INSTABILITIES DOWN ON MONDAY... ALL SUPPORTING A LESSOR CHANCE FOR
SEVERE STORMS.
OTHERWISE... A MAV AND MET BLEND GAVE NEAR NORMAL TEMPS THROUGH THE
FORECAST PERIOD... WHICH LOOKS REASONABLE... SO DID NOT STRAY.
39
LONG TERM /TUESDAY THROUGH SUNDAY/...
NO CHANGES MADE TO THE EXTENDED FORECAST. DEEP MOISTURE ASSOCIATED
WITH SW FLOW ALOFT WILL BE ACROSS THE AREA TO START THE LONG TERM
WITH RATHER HIGH PRECIPITATION CHANCES TUESDAY. EVEN THOUGH AN
UPPER RIDGE BUILDS SLIGHTLY OVER S GA ON WEDNESDAY...A MOIST
AIRMASS WILL CONTINUE FROM SW FLOW ALOFT. THE UPPER RIDGE
CONTINUES TO BUILD ON THURSDAY WITH THE SW FLOW ALOFT BECOMING
WEAKER BUT A MOIST AIRMASS CONTINUES OVER THE AREA...MOST SO ON
THE GFS AND LESS SO ON THE EUROPEAN. THE UPPER RIDGE CONTINUES TO
BUILD FRIDAY AND SATURDAY WITH A RATHER MOIST AIRMASS CONTINUING
ALLOWING FOR AT LEAST A CHANCE OF SHOWERS AND THUNDERSTORMS EACH
DAY.
FORECAST LOW TEMPERATURES EXPECTED TO BE AROUND NORMAL AND FORECAST HIGH
TEMPERATURES START OUT BELOW NORMAL BUT ARE EXPECTED TO WARM AROUND
NORMAL TOWARD WEEKS END.
BDL/01
&&
.AVIATION...
06Z UPDATE...
MOSTLY VFR CIGS AT THIS TIME BUT EXPECT MVFR/IFR CIGS TO DEVELOP
THROUGH THE EARLY MORNING HOURS...RISING TO VFR BY NOON.
SHOWERS/TSTORMS WILL BEGIN DEVELOPING BY MID MORNING AND BECOME
SCATTERED TO WIDESPREAD THIS AFTERNOON...DIMINISHING THIS EVENING.
WINDS WILL BE SOUTHEAST THROUGH THIS EVENING...BECOMING SOUTHWEST
AFTER 06Z TUESDAY IN ATL.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM ON CIGS AND TIMING OF SHRA/TSRA
HIGH ON REMAINING ELEMENTS
17
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 87 71 86 71 / 70 70 70 70
ATLANTA 85 73 85 72 / 70 70 70 70
BLAIRSVILLE 80 66 79 65 / 80 80 70 60
CARTERSVILLE 85 70 85 70 / 80 80 70 60
COLUMBUS 88 74 89 73 / 60 60 60 50
GAINESVILLE 83 71 82 71 / 70 70 70 70
MACON 88 73 89 72 / 60 60 60 70
ROME 84 71 85 70 / 80 80 70 60
PEACHTREE CITY 85 71 86 70 / 70 70 60 60
VIDALIA 89 73 89 72 / 60 60 70 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...17
LONG TERM....BDL
AVIATION...17
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1231 AM CDT MON AUG 17 2015
.UPDATE...
ISSUED AT 928 PM CDT SUN AUG 16 2015
CONCERN THIS EVENING REMAINS FLASH FLOOD POTENTIAL. RADAR
ESTIMATES AND OBSERVATIONS INDICATE PORTIONS OF ABOUT FOUR NW/N
CENTRAL COUNTIES HAVE SEEN TWO TO THREE INCHES OF RAINFALL
ALREADY. PWATS AND WARM CLOUD DEPTHS ARE ALL QUITE FAVORABLE FOR
VERY EFFICIENT RAINS BUT WEAKENING INSTABILITY WITH LOSS OF
HEATING WILL MAKE IT DIFFICULT TO REALIZE THESE CONDITIONS ON A
WIDESPREAD BASIS. WITH ONE HOUR FLASH FLOOD GUIDANCE PUSHING 2.50
INCHES...MOST LOCATIONS CAN TAKE ONE EVENT WITH 2-3 EVENTS NEEDED
TO GET TO FLASH FLOOD CRITERIA. RAP 305K ISENT MOISTURE
CONVERGENCE SUGGESTS RECENT POST FRONTAL CONVECTIVE DEVELOPMENT
OVER NW IA WILL CONTINUE THROUGH MIDNIGHT...BUT HAVE OPTED FOR
TARGETED SPS ISSUANCES RATHER THAN MORE WIDESPREAD FLASH FLOOD
WATCH FOR REASONS ALSO NOTED IN SHORT TERM SECTIONS BELOW.
&&
.SHORT TERM /TONIGHT/...
ISSUED AT 329 PM CDT SUN AUG 16 2015
SFC COLD FRONT IS SINKING SLOWLY THROUGH SOUTHEAST SOUTH DAKOTA AND
SOUTHWEST MINNESOTA THIS AFTERNOON. A WEAK UPPER RIDGE REMAINS
STRETCHED THROUGH CENTRAL IOWA AND IS SEPARATING THE MUCH DRIER AIR
TO THE SOUTHEAST FROM THE DEEPER MOISTURE TO THE WEST AND NORTHWEST
OF THE SYSTEM. THE RIDGE WILL SHIFT SOUTHEAST AND WEAKEN FURTHER
OVERNIGHT ALLOWING THE SFC BOUNDARY TO ENTER NORTHERN IOWA. THE
OVERALL FORCING AND INSTABILITY OVERNIGHT IS LIMITED AND DESPITE A
RELATIVELY WEAK LOW LEVEL JET...THE MOISTURE TRANSPORT LIFTING INTO
THE BOUNDARY IS GOOD AND WILL HELP PUSH PWATS TO NEAR 2 INCHES OVER
NORTHERN IOWA. WARM CLOUD DEPTHS AROUND 13 KFT ARE SUPPORTIVE OF AN
EFFICIENT RAIN PRODUCING ENVIRONMENT AND MEAN STORM MOTIONS ARE
CLOSE TO PARALLEL TO THE SFC BOUNDARY LEADING TO THE POTENTIAL FOR
TRAINING STORMS.
GIVEN ALL OF THE ABOVE...DO EXPECT SOME AREAS WITH HEAVY RAINFALL
POSSIBLY EXCEEDING 3 INCHES. PLANNING TO HOLD OFF ON A FLASH FLOOD
WATCH AT THIS TIME FOR A VARIETY OF REASONS. MUCH OF NORTHERN IOWA
NORTH OF HIGHWAY 20 HAVE HAD ONE HALF INCH OR LESS OF PRECIPITATION
FOR AUGUST. THE CROPS ARE NEARING FULL MATURATION AND LIMIT RUNOFF
RATES AND THE AREA WITH THE GREATEST THREAT FOR HEAVY RAIN OVER THE
FAR NORTHWEST ARE CLIMATOLOGICALLY DIFFICULT TO FLASH FLOOD DUE TO
THE LANDSCAPE. WILL MENTION LOCALIZED FLASH FLOODING POSSIBLE IN THE
HWO. SHOULD THE THREAT FOR HIGHER QPF ARISE...THEN HEADLINES MAY BE
REQUIRED. THE SEVERE WEATHER THREAT IS LOW...GIVEN THE DEEPER WARM
CLOUD DEPTHS AND SATURATED PROFILES...THE HAIL THREAT WILL BE LOW
LEAVING AN ISOLATED DAMAGING WIND GUST AS THE PRIMARY SEVERE THREAT.
.LONG TERM /MONDAY THROUGH SUNDAY/...
ISSUED AT 329 PM CDT SUN AUG 16 2015
CURRENTLY HAVE AN AREA OF LOW PRESSURE CENTERED ACROSS SRN MANITOBA
AND SASKATCHEWAN...THIS WILL PUSH INTO SOUTHERN ONTARIO SUNDAY
EVENING WITH THE ASSOCIATED COLD FRONT TO PUSH INTO NORTHWESTERN
IOWA AND THE NORTHWESTERN CWA BY LATE SUNDAY. THE FRONTAL BOUNDARY
WILL CONTINUE TO PUSH SOUTHWARD ACROSS THE CWA...STALLING OUT ACROSS
THE AREA BY LATER MONDAY INTO TUESDAY. THIS WILL ALLOW FOR AN
EXTENDED PERIOD OF RAIN CHANCES BEGINNING MAINLY LATE SUNDAY
AFTERNOON NORTHWEST AND SPREADING ACROSS THE CWA SUNDAY NIGHT INTO
MONDAY. THETA-E ADVECTION BETTER ACROSS THE NORTH INTO THE
EVENING...WITH MOISTURE CONVERGENCE INCREASING ALONG THE FRONT INTO
THE LATE NIGHT HOURS. WITH THE GRADUAL MOVEMENT IN THE FRONT...AND
MID LEVEL FLOW PARALLEL TO THE BOUNDARY...TRAINING OF STORMS IS
POSSIBLE. PWATS ALSO HIGH IN THE 1.9 TO 2 INCH RANGE...FURTHERING
HEAVY RAIN CHANCES. HOWEVER THIS AREA HAS BEEN DRIER AND FFG IS
HOVERING AROUND 3 INCHES OR JUST BELOW FOR 3 HOURS...THEREFORE THE
FLASH FLOOD THREAT IS MINIMIZED SOME.
AN UPPER LEVEL TROUGH WILL DIG INTO THE WESTERN US WITH A WEST TO
SOUTHWEST FLOW PATTERN SETTING UP TOWARD MID WEEK. A STRONGER AREA
OF LOW PRESSURE IS EXPECTED TO LIFT OUT OF THE SOUTHERN HIGH PLAINS
THROUGH IOWA AND INTO THE GREAT LAKES TUESDAY INTO WEDNESDAY. THIS
SYSTEM WILL EJECT ENERGY INTERACTING WITH THE LINGERING BOUNDARY
BRINGING THE NEXT WIDESPREAD CHANCES FOR PRECIPITATION TO MUCH OF
THE STATE. SHEAR PARAMETERS ALSO INCREASE WITH THE APPROACHING AREA
OF LOW PRESSURE ALLOWING FOR SEVERE WEATHER CHANCES AS WELL. WRAP-
AROUND PRECIP POSSIBLE INTO WEDNESDAY/WEDNESDAY NIGHT WITH HIGH
PRESSURE TO BUILD INTO THE AREA BY THURSDAY/FRIDAY. THIS SHOULD
ALLOW THE AREA TO DRY OUT BY THE END OF THE WEEK BEFORE PRECIP
CHANCES RETURN FOR THE WEEKEND WITH ANOTHER UPPER LEVEL TROUGH
PUSHING EAST FROM THE ROCKIES AND THROUGH THE NORTHERN PLAINS.
MODELS IN DISAGREEMENT OVER HOW FAR NORTH THIS SYSTEM WILL
TRACK...WITH THE EC MORE BULLISH KEEPING IT FURTHER SOUTH WHICH
WOULD BE MORE OF AN IMPACT TO THE CWA VERSUS THE GFS WHICH KEEPS THE
MAIN TROUGH ACROSS SOUTHERN CANADA.
TEMPERATURES EXPECTED TO BE HOT AND HUMID SUNDAY AS DEWPOINTS
INCREASE AHEAD OF THE COLD FRONT AND H85 TEMPS PUSH INTO THE LOW 20S
CELSIUS IN SOUTHERLY TO SOUTHWESTERLY FLOW. TEMPS TO DROP INTO THE
MID TEENS CELSIUS AS THE FRONT SAGS SOUTH...WITH COOLER TEMPS FOR
MUCH OF THE WEEK. TEMPS EXPECTED TO RETURN TO THE 80S AS SOUTHERLY
FLOW WARMS THINGS BACK UP AGAIN FRIDAY INTO SATURDAY AHEAD OF THE
UPPER LEVEL TROUGH.
&&
.AVIATION...17/06Z
ISSUED AT 1231 AM CDT MON AUG 17 2015
CONFIDENCE IS LOW THROUGH THE PERIOD WITH SHOWERS AND STORMS
POSSIBLE THE ENTIRE TIME...AND AN INCREASED POTENTIAL FOR STRATUS
NORTH LATE. HAVE PLAYED THUNDER AND CATEGORY RESTRICTIONS
SOMEWHAT CONSERVATIVE DEPENDING ON NEAR TERM TRENDS. WILL LEAVE
BROADER VICINITY WORDING UNTIL CONFIDENCE INCREASES ON THE ORDER
OF HOURS. MODELS SUGGEST LOWERING CIGS WITH SAGGING FRONT AND
OUTFLOW BOUNDARIES...ALONG WITH PROLONGED PERIOD OF SCATTERED
PRECIP.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...SMALL
SHORT TERM...DONAVON
LONG TERM...BEERENDS
AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS TOPEKA KS
606 PM CDT TUE AUG 18 2015
...AVIATION UPDATE...
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 335 PM CDT TUE AUG 18 2015
19Z WATER VAPOR SHOWS A CLOSED UPPER LOW OVER SD WHILE SURFACE OBS
PLACE THE LOW OVER NORTHWEST IA/SOUTHWEST MN BORDER. A STRONG COLD
FRONT EXTENDED SOUTH FROM THE SURFACE LOW THROUGH SOUTHEAST NEB TO
JUST WEST OF SLN. VISIBLE SATELLITE HAS SHOWN SOME BREAKS IN THE
CLOUDS AHEAD OF THE FRONT WHICH HAS ALLOWED TEMPS TO WARM INTO THE
LOWER 80S. THIS WOULD SUPPORT SURFACE BASED CAPE VALUES AROUND
1000J/KG WHILE 0-6 KM SHEAR INCREASES TO AROUND 45 KTS. SO THE
POTENTIAL FOR SEVERE STORMS REMAINS IN PLACE. MODELS SHOW AREA ALONG
AND SOUTH OF I-70 AS THE PLACES THAT SHOULD SEE THE BETTER
INSTABILITY. THEREFORE THINK THIS MAY BE WHERE STRONG TO SEVERE
STORMS DEVELOP THIS AFTERNOON, IF THEY STRENGTHEN. SINCE SURFACE
WINDS HAVE VEERED TO THE SOUTHWEST AHEAD OF THE FRONT, THE POTENTIAL
FOR TORNADOES APPEARS TO REMAIN FAIRLY SMALL. THE RAP AND HRRR,
WHICH HAVE SHOWN A BETTER TIMING FOR THE FRONT, TAKE THE BOUNDARY
EAST OF THE FORECAST AREA BETWEEN 8 AND 9 PM. THE RISK FOR SEVERE
WEATHER SHOULD DIMINISH QUICKLY BEHIND THE FRONT AS COOLER MORE
STABLE AIR COMES IN.
ONCE THE FRONT PASSES EAST, THINK THE REST OF TONIGHT WILL BE FAIRLY
UNEVENTFUL. THERE HAVE BEEN SOME LOWER CLOUDS ACROSS WESTERN NEB
MIST OF THE DAY BUT THE MODELS TEND TO KEEP THE LOWER CLOUDS TO THE
NORTH OVERNIGHT. THEREFORE WITH COLD AIR ADVECTION AND MOST LIKELY
PARTLY CLOUDY SKIES, LOWS IN THE MID AND UPPER 50S LOOKS ON TARGET.
BY LATE TONIGHT AND THROUGH THE MORNING WEDNESDAY, MODELS SWING A
DECENT VORT MAX THROUGH THE BASE OF THE UPPER TROUGH PASSING THROUGH
EASTERN KS. THERE IS NO SIGN OF LOW LEVEL MOISTURE ADVECTION OVER
THE COLD FRONT, BUT THERE IS AN INDICATION OF A SATURATED AIRMASS
ACROSS EAST CENTRAL KS WITH GOOD FRONTOGENESIS AS THE WAVE PASSES
OVERHEAD. BECAUSE OF THIS HAVE CONTINUED WITH SOME CHANCE POPS FOR
RAIN MAINLY OVER EAST CENTRAL KS. THERE SHOULD BE MORE DRY AIR OVER
NORTH CENTRAL AND NORTHEAST KS THAT WILL LIMIT PRECIP CHANCES. THE
COLD AIR ADVECTION WEAKENS THROUGH THE DAY WEDNESDAY, BUT THERE MAY
BE SOME CLOUDS LINGER. THEREFORE HIGHS ARE FORECAST TO TOP OUT IN
THE LOWER AND MID 70S. THIS IS ABOUT 15 DEGREES BELOW NORMAL FOR
THIS TIME OF YEAR.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 335 PM CDT TUE AUG 18 2015
LOWER LEVEL WINDS BACK TO THE WEST WEDNESDAY NIGHT AND THEN
SOUTHWEST INTO THURSDAY NIGHT BRINGING SOME WARMING BACK AND SURFACE
TEMPS SHOULD MODIFY CONSIDERABLY. HAVE KEPT VALUES NEAR TO BELOW
MOS FOR WEDNESDAY NIGHT IN LIGHT WINDS AND CLEAR SKIES. MODELS
TRENDING A BIT COOLER FOR FRIDAY WITH CONTINUED BACKED TO NEAR
SOUTHEAST WITH HIGHS STILL LIKELY CLOSE TO THOSE OF THURSDAY. PRECIP
CHANCES CONTINUE TO LOOK QUITE LOW THROUGH THURSDAY NIGHT. AT LEAST
SOME MOISTURE RETURNS AHEAD OF A WEAK UPPER WAVE FRIDAY...THOUGH
THERE REMAINS TO BE A WIDE DEGREE OF VARIANCE IN BOTH OF THESE
ELEMENTS...WITH A TREND TOWARD LOWER AVAILABLE MOISTURE NOTED. AT
THIS POINT CHANCES FOR ANYTHING MORE THAN ISOLATED PRECIP LOOK LOW.
FOR THE BEGINNING OF THE WEEKEND, RETURN FLOW WILL BE IN PLACE OVER
THE SOUTHERN AND CENTRAL PLAINS AHEAD OF A DEEPENING TROUGH OVER THE
NORTHERN ROCKIES. THIS SYSTEM WILL CONTINUE EASTWARD PROGRESSION
INTO THE DAY SATURDAY AND OVERNIGHT INTO SUNDAY BEFORE IT BECOMES
MORE NEGATIVELY TILTED AND LIFTS THROUGH THE UPPER MISSISSIPPI
VALLEY INTO THE GREAT LAKES REGION BY MONDAY. THIS LARGER SCALE
FEATURE SHOULD BRING ABOUT THE CHANCE OF ELEVATED STORMS FOR
SATURDAY MORNING AS A LLJ SHOULD HELP ENHANCE AN AREA OF ISENTROPIC
LIFT OVER EASTERN KS. INTO THE DAY, SOUNDINGS DO SUGGEST THAT STORM
POTENTIAL MAY BE LIMITED WITH A PRETTY STRONG CAP DEVELOPING OVER
THE REGION. THE BETTER CHANCE FOR THUNDERSTORM REDEVELOPMENT WILL
BE IN THE LATE AFTERNOON INTO THE EARLY EVENING AS SHEAR PROFILES
BECOME A LITTLE MORE ORGANIZED AND WAA INCREASES LOW LEVEL MOISTURE
ALONG WITH INSTABILITY OVER THE REGION. SOME POTENTIAL FOR STRONG
TO SEVERE STORMS COULD EXIST, BUT STILL TOO FAR OUT TO PINPOINT
OVERALL LIKELIHOOD. MODELS SEEM TO BE IN FAIRLY GOOD AGREEMENT FOR
THE MOST PART WITH EASTWARD PROGRESSION OF THE TROUGH. THE GFS
SOLUTION DOES SEEM TO BE THE MORE AGGRESSIVE OF THE SOLUTIONS THOUGH
WITH A DEEPER UPPER LOW AND MORE NORTHERLY PROGRESSION AFTER THE
MONDAY MORNING TIME FRAME. IN THE WAKE OF THIS FALL-LIKE LOOKING
SYSTEM, WILL BE ANOTHER NICE FEW DAYS AS HEIGHTS RISE AND SUBSIDENCE
SETS IN WITH SIGNIFICANT MOISTURE BEING PUSHED SOUTH.
HIGH TEMPS COOL BEHIND THE SYSTEM INTO THE UPPER 70S
AND ONLY CLIMB INTO THE MID 80S BY TUESDAY. LOWS MEANWHILE COULD
FLIRT WITH LOW 50S IN PARTS OF THE AREA BY TUESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 606 PM CDT TUE AUG 18 2015
WITH THE FRONT THROUGH THE TERMINALS, VFR CONDITIONS ARE EXPECTED
TO PERSIST THROUGH THE NIGHT. RAP AND NAM RH PROGS KEEP ANY LOWER
SATURATION TO THE NORTH OF THE TERMINALS SO CHANCE FOR MVFR CIGS
APPEARS TO BE LOW AT THIS TIME. THERE SHOULD ALSO BE ENOUGH MIXING
ALONG WITH DRY AIR ADVECTION TO PREVENT AND GROUND FOG FROM
FORMING.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...WOLTERS
LONG TERM...65/DRAKE
AVIATION...WOLTERS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
252 PM MDT MON AUG 17 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 250 PM MDT MON AUG 17 2015
EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW
STRENGTHENING TROUGH ACROSS MONTANA WITH SHARP PV HEIGHT ANOMALY
DIGGING INTO NORTHWESTERN WYOMING. DIFFLUENT FLOW IS IN PLACE
ACROSS NORTHERN COLORADO WITH INCREASING DIVERGENT SIGNATURE
AHEAD OF APPROACHING UPPER LEVEL JET. AT THE SURFACE A STATIONARY
FRONT EXTENDS FROM NORTH CENTRAL KANSAS TO SOUTHEAST
COLORADO...ACROSS THE SOUTHEAST PART OF OUR CWA...WITH A WEAK
SURFACE TROUGH AXIS EXPENDING ACROSS THE NW PART OF OUR FORECAST
AREA.
THUNDERSTORMS SHOULD INITIATE ACROSS EASTERN COLORADO THIS
AFTERNOON WITH ACTIVITY INCREASING IN COVERAGE AND SPREADING EAST
INTO OUR CWA THROUGH THE EVENING/OVERNIGHT. BEST FORCING IS
ADVERTISED 03-06Z OVER OUR CWA AND QUICKLY TRANSITIONS EASTWARD
THROUGH TUESDAY MORNING. AS THE UPPER LOW DEEPENS AND EVENTUALLY
CLOSES OFF OVER NEBRASKA DRY SLOT/SUBSIDENT REGION WILL MOVE OVER
OUR CWA WHICH SHOULD RAPIDLY DECREASE ANY SHOWER/THUNDERSTORM
CHANCES. STRONG COLD FRONT WILL DROP DOWN ACROSS THE REGION
TUESDAY MORNING AND COMBINED WITH INCREASING SUBSIDENCE BRING
MILD/WINDY (VERY FALL-LIKE) CONDITIONS TO OUR CWA. THERE MAY ALSO
BE A REDEVELOPMENT OF DENSE FOG/LOW STRATUS OVER SW NEBRASKA
DEPENDING ON THUNDERSTORM ACTIVITY/MIXING AND FRONTAL TIMING.
REGARDING SEVERE POTENTIAL TONIGHT...RAP ANALYSIS SHOWS SB CAPE
AXIS 2500-3500 J/KG AND DEEP BULK EFFECTIVE SHEER VALUES 40-50KT
ACROSS EASTERN COLORADO. CONSIDERING THE DEEP LAYER SHEER AND
INSTABILITY WE ARE ANTICIPATING ORGANIZED SUPERCELLS DEVELOPING
LATE THIS AFTERNOON AND SLOWLY PROGRESSING EASTWARD (MEAN STORM
MOTIONS 10-20KT). THERE IS A WINDOW WITH LOW LEVEL TURNING ALONG
SURFACE TROUGH AXIS FOR TORNADOES WITH MORE ORGANIZED CELLS...WITH
PRIMARY THREAT VERY LARGE HAIL (2"+) AND DAMAGING WINDS. AS THIS
ACTIVITY ORGANIZES INTO A MCS/THUNDERSTORM CLUSTER TORNADO THREAT
SHOULD DIMINISH. TORNADO WATCH 490 IS CURRENTLY IN EFFECT FOR OUR
EASTERN COLORADO COUNTIES...AND PATTERN IS BEING MONITORED FOR
ANY OTHER POSSIBLE SEVERE WATCHES AS THIS UNFOLDS THIS
AFTERNOON/EVENING.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 156 PM MDT MON AUG 17 2015
JET MAX ROTATING AROUND BACK OF THE UPPER TROUGH WILL BRING
SCATTERED SHOWERS TO THE AREA TUESDAY NIGHT THROUGH WEDNESDAY
MORNING UNDER THE DIVERGENT LEFT EXIT REGION. MODEL QPF IS
LIGHT...GENERALLY BETWEEN A TENTH AND A QUARTER OF AN INCH...BUT
RATHER WIDESPREAD SO POPS MAY NEED TO BE INCREASED IF THOSE TRENDS
CONTINUE. POINT FORECAST SOUNDINGS ACTUALLY SHOW ICE IN THE COLUMN
BUT THE SURFACE BASED WARM LAYER EXTENDS TO AROUND 6KFT AGL WHICH
WILL BE MORE THAN SUFFICIENT TO KEEP ANY KIND OF SNOW FROM
REACHING THE GROUND. LOW TEMPERATURES A BIT TRICKY...WITH CLOUDS
POTENTIALLY KEEPING THEM FROM REACHING THE UPPER 40S BUT IF THE
RAIN IS PROLONGED MIGHT WET BULB DOWN TO NEAR THAT ANYWAY. EITHER
WAY IT WILL BE A RATHER CHILLY MORNING FOR MID AUGUST.
UPPER TROUGH WILL MOVE OUT WEDNESDAY AFTERNOON WITH NORTHWEST
FLOW ALOFT THROUGH THE END OF THE WEEK. PRECIPITATION CHANCES
DURING THAT TIME WILL BE SLIM TO NONE WITH NO UPPER SHORTWAVES IN
THE MODELS AND LIMITED MOISTURE AVAILABLE. TEMPERATURES WILL
REBOUND QUICKLY AFTER THE MIDWEEK COOL DOWN WITH ABOVE NORMAL
HIGHS BY FRIDAY. THE UPPER FLOW WILL TRANSITION TO ZONAL AND THEN
SOUTHWEST OVER THE WEEKEND AS ANOTHER TROUGH DIGS INTO THE
NORTHERN ROCKIES. THE NEXT BEST CHANCE FOR THUNDERSTORMS WILL BE
SATURDAY AFTERNOON/EVENING AS DYNAMICS AND SURFACE COLD FRONT
ASSOCIATED WITH THAT SYSTEM MOVE THROUGH THE CENTRAL PLAINS. A
LITTLE EARLY...BUT RIGHT NOW BEST COMBINATION OF INSTABILITY AND
SHEAR WILL BE CONFINED TO EASTERN PARTS OF THE FORECAST
AREA...NORTON TO GOVE...WHICH WOULD BE THE FAVORED AREAS FOR ANY
SEVERE THREAT. IF THAT TIMING VERIFIES SUNDAY AND MONDAY WILL BE
DRY AND A LITTLE COOLER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1141 AM MDT MON AUG 17 2015
LOW STRATUS RESPONSIBLE FOR IFR/MVFR CIGS WILL SLOWLY LIFT THROUGH
THE AFTERNOON AS A WARM FRONT LIFTS NORTH TO BE NEAR KGLD.
THUNDERSTORMS SHOULD REDEVELOP ALONG AND SOUTH OF THIS FRONT LATE
THIS AFTERNOON AND SLOWLY SPREAD EAST. BETTER COVERAGE MAY END UP
REMAINING SOUTH OF KMCK OVER KGLD...HOWEVER THERE WILL BE AT LEAST
SCATTERED COVERAGE ACROSS SW NEBRASKA AS UPPER LEVEL SYSTEM MOVES
INTO THE NORTHERN PLAINS. LOW LEVEL MOISTURE AND LIGHT EASTERLY
WINDS WILL HELP WITH STRATUS/FOG REDEVELOPMENT LATE TONIGHT
THROUGH EARLY TUESDAY MORNING AT KMCK. VFR CONDITIONS SHOULD
PREVAIL AT KGLD AFTER THUNDERSTORM ACTIVITY MOVES EAST TONIGHT. A
STRONG COLD FRONT MOVING THROUGH THE REGION 13-16Z WILL HELP
IMPROVE CONDITIONS AT KMCK...AND WILL BRING GUSTY NORTH WINDS TO
BOTH TERMINALS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...024
AVIATION...DR
AREA FORECAST DISCUSSION
NWS WICHITA KS
1233 PM CDT MON AUG 17 2015
...UPDATED FOR 18Z AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 317 AM CDT MON AUG 17 2015
CONVECTION IS DECREASING IN AREAL EXTENT BUT CONTINUING ACROSS
SOUTHWEST KANSAS AND OVER NORTH CENTRAL KANSAS AND NORTHEAST INTO
SOUTHEAST NEBRASKA. THIS SCATTERED CONVECTION IS EXPECTED TO
LINGER...BUT DIMINISH INTO THE EARLY MORNING HOURS.
BILLINGS WRIGHT
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 317 AM CDT MON AUG 17 2015
TODAY - TONIGHT: THE HIGH RESOLUTION GUIDANCE HRRR AND THE HIGHER
RESOLUTION NAM12 STRUGGLE TO SHOW MUCH CONVECTION PERSISTING
ACROSS CENTRAL KANSAS DURING THE EARLY PART OF THE DAY. A PIECE
OF ENERGY WILL APPROACH THE AREA FROM THE NORTHWEST DURING THE
LATE AFTERNOON HOURS WHICH WILL INCREASE THE CHANCES FOR
CONVECTION INTO THE EVENING ESPECIALLY OVER CENTRAL AND SOUTH
CENTRAL KANSAS. SHEAR WILL BE LACKING...BUT THERE IS A MODEST
1000-1500 J/KG CAPE FOR THUNDERSTORMS TO POTENTIALLY BE
STRONG...AND WITH THE WEAK FLOW...FLOODING COULD BE A CONCERN AS
WELL. MOISTURE TRANSPORT INCREASES DURING THE OVERNIGHT HOURS
INCREASING THE PRECIPITATION CHANCES FOR SOUTH CENTRAL KANSAS.
TUESDAY - WEDNESDAY:
THE STRONGER UPPER LEVEL WAVE WILL MOVE INTO THE REGION DURING THE
DAY TUESDAY...BUT THE MAIN FRONTAL PUSH WILL BE LATER TUESDAY
EVENING WHEN THE UPPER LOW DIGS SLIGHTLY DEEPER. THE UPPER PV
ENERGY MOVING ACROSS THE AREA TUESDAY WILL INCREASE THE CHANCE
FOR THUNDERSTORMS THROUGHOUT THE DAY. THE UPPER WAVE WILL BE
CLOSER TO KANSAS INCREASING THE UPPER SHEAR PROFILE. SEVERE STORMS
MAY BE POSSIBLE ESPECIALLY OVER CENTRAL AND NORTHERN PORTIONS OF
SOUTH CENTRAL KANSAS WHERE THE COMBINATION OF SHEAR AND
INSTABILITY ARE ANTICIPATED TO BE THE GREATEST. ELSEWHERE STORMS
COULD BE STRONG.
BY TUESDAY NIGHT THE MAIN COLD FRONT/WIND SHIFT WILL BEGIN MOVING
ACROSS CENTRAL AND EASTERN KANSAS. THUNDERSTORMS ALONG THE FRONT
ARE POSSIBLE...BUT THE CONVERGENCE ISN`T OVERWHELMING. THE FRONT
IS EXPECTED TO BE FAIRLY PROGRESSIVE AND MOVE THROUGH THE AREA BY
EARLY MORNING WEDNESDAY. A FEW STRONGER STORMS REMAIN POSSIBLE
ALONG THE FRONT.
A SECONDARY PIECE OF ENERGY WILL MOVE SOUTHWARD INTO THE UPPER LOW
CAUSING THE POTENTIAL FOR SCATTERED SHOWERS DURING THE DAY
WEDNESDAY.
THE FRONT WILL CAUSE TEMPERATURES ON WEDNESDAY TO BE SIGNIFICANTLY
COOLER THAN RECENT DAYS...STEADILY COOLING FROM A HIGH CLOSE TO
NORMAL TODAY IN THE LOW 90S TO THE LOW TO MID 70S BY WEDNESDAY.
BILLINGS WRIGHT
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 317 AM CDT MON AUG 17 2015
WHILE THERE ARE SOME SLIGHT DISCREPANCIES AMONGST THE MEDIUM
RANGE GUIDANCE...THE PATTERN REMAINS ACTIVE AND GENERALLY IN
FAIRLY GOOD AGREEMENT. ZONAL FLOW WILL RETURN BRIEFLY AHEAD OF THE
NEXT SYSTEM FOR THE WEEKEND...BUT BEFORE THAT A WEAK TROUGH WILL
IMPACT THE AREA FOR THE END OF THE WEEK.
THE WEAK TROUGH MAY BRING CHANCES FOR RAIN THURSDAY NIGHT AND
FRIDAY...BUT CONFIDENCE IS LOWER DUE TO DISCREPANCIES.
TEMPERATURES WILL STEADILY INCREASE BACK INTO THE 80S...BUT THE
NEXT FRONT WILL APPROACH AND TRAVERSE THE AREA SATURDAY
NIGHT/SUNDAY MORNING. THIS FRONT WILL BRING THE NEXT BEST CHANCE
OF RAIN TO THE REGION. THIS PERIOD HAS HIGHER CONFIDENCE DUE TO
BETTER AGREEMENT ACROSS VARIOUS MODEL SOLUTIONS.
BILLINGS WRIGHT
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1229 PM CDT MON AUG 17 2015
VFR CONDITIONS SHOULD BE THE RULE FOR THIS FORECAST PERIOD WITH
SOME VCTS NOTED FOR ALL SITES EXCEPT FOR KCNU. CURRENT BOUNDARY TO
THE NORTHWEST WILL SLOWLY PROGRESS ACROSS THE FORECAST AREA ON
TUESDAY BRINGING A CHANGE IN WEATHER TO THE AREA. WINDS WILL
INCREASE EARLY ON TUESDAY MORNING AND THEN BEGIN A TRANSITION TO A
NORTHEASTERLY DIRECTION BY THE END OF TUESDAY. AHEAD OF THE
BOUNDARY...VERY LITTLE CONVERGENCE SEEMS TO BE PRESENT AND THE
UPPER SUPPORT SEEMS TO BE WANING A BIT. SO CHANCES FOR TRW ARE
DECREASING THIS AFTERNOON AND OVERNIGHT. SLIGHTLY BETTER CHANCES
WILL OCCUR LATER ON TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 90 71 84 60 / 20 50 60 70
HUTCHINSON 90 70 85 58 / 20 50 50 60
NEWTON 89 69 84 57 / 20 50 50 70
ELDORADO 90 71 84 58 / 20 50 60 70
WINFIELD-KWLD 91 71 85 60 / 20 50 60 70
RUSSELL 88 66 83 54 / 20 50 60 30
GREAT BEND 89 68 85 55 / 20 50 60 40
SALINA 90 70 85 57 / 20 50 60 50
MCPHERSON 90 70 85 57 / 20 50 50 60
COFFEYVILLE 91 72 86 64 / 20 40 60 70
CHANUTE 90 72 84 61 / 20 40 60 70
IOLA 90 71 83 61 / 20 40 60 70
PARSONS-KPPF 91 71 85 62 / 20 30 60 70
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
620 AM CDT MON AUG 17 2015
...UPDATED FOR 12Z AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 317 AM CDT MON AUG 17 2015
CONVECTION IS DECREASING IN AREAL EXTENT BUT CONTINUING ACROSS
SOUTHWEST KANSAS AND OVER NORTH CENTRAL KANSAS AND NORTHEAST INTO
SOUTHEAST NEBRASKA. THIS SCATTERED CONVECTION IS EXPECTED TO
LINGER...BUT DIMINISH INTO THE EARLY MORNING HOURS.
BILLINGS WRIGHT
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 317 AM CDT MON AUG 17 2015
TODAY - TONIGHT: THE HIGH RESOLUTION GUIDANCE HRRR AND THE HIGHER
RESOLUTION NAM12 STRUGGLE TO SHOW MUCH CONVECTION PERSISTING
ACROSS CENTRAL KANSAS DURING THE EARLY PART OF THE DAY. A PIECE
OF ENERGY WILL APPROACH THE AREA FROM THE NORTHWEST DURING THE
LATE AFTERNOON HOURS WHICH WILL INCREASE THE CHANCES FOR
CONVECTION INTO THE EVENING ESPECIALLY OVER CENTRAL AND SOUTH
CENTRAL KANSAS. SHEAR WILL BE LACKING...BUT THERE IS A MODEST
1000-1500 J/KG CAPE FOR THUNDERSTORMS TO POTENTIALLY BE
STRONG...AND WITH THE WEAK FLOW...FLOODING COULD BE A CONCERN AS
WELL. MOISTURE TRANSPORT INCREASES DURING THE OVERNIGHT HOURS
INCREASING THE PRECIPITATION CHANCES FOR SOUTH CENTRAL KANSAS.
TUESDAY - WEDNESDAY:
THE STRONGER UPPER LEVEL WAVE WILL MOVE INTO THE REGION DURING THE
DAY TUESDAY...BUT THE MAIN FRONTAL PUSH WILL BE LATER TUESDAY
EVENING WHEN THE UPPER LOW DIGS SLIGHTLY DEEPER. THE UPPER PV
ENERGY MOVING ACROSS THE AREA TUESDAY WILL INCREASE THE CHANCE
FOR THUNDERSTORMS THROUGHOUT THE DAY. THE UPPER WAVE WILL BE
CLOSER TO KANSAS INCREASING THE UPPER SHEAR PROFILE. SEVERE STORMS
MAY BE POSSIBLE ESPECIALLY OVER CENTRAL AND NORTHERN PORTIONS OF
SOUTH CENTRAL KANSAS WHERE THE COMBINATION OF SHEAR AND
INSTABILITY ARE ANTICIPATED TO BE THE GREATEST. ELSEWHERE STORMS
COULD BE STRONG.
BY TUESDAY NIGHT THE MAIN COLD FRONT/WIND SHIFT WILL BEGIN MOVING
ACROSS CENTRAL AND EASTERN KANSAS. THUNDERSTORMS ALONG THE FRONT
ARE POSSIBLE...BUT THE CONVERGENCE ISN`T OVERWHELMING. THE FRONT
IS EXPECTED TO BE FAIRLY PROGRESSIVE AND MOVE THROUGH THE AREA BY
EARLY MORNING WEDNESDAY. A FEW STRONGER STORMS REMAIN POSSIBLE
ALONG THE FRONT.
A SECONDARY PIECE OF ENERGY WILL MOVE SOUTHWARD INTO THE UPPER LOW
CAUSING THE POTENTIAL FOR SCATTERED SHOWERS DURING THE DAY
WEDNESDAY.
THE FRONT WILL CAUSE TEMPERATURES ON WEDNESDAY TO BE SIGNIFICANTLY
COOLER THAN RECENT DAYS...STEADILY COOLING FROM A HIGH CLOSE TO
NORMAL TODAY IN THE LOW 90S TO THE LOW TO MID 70S BY WEDNESDAY.
BILLINGS WRIGHT
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 317 AM CDT MON AUG 17 2015
WHILE THERE ARE SOME SLIGHT DISCREPANCIES AMONGST THE MEDIUM
RANGE GUIDANCE...THE PATTERN REMAINS ACTIVE AND GENERALLY IN
FAIRLY GOOD AGREEMENT. ZONAL FLOW WILL RETURN BRIEFLY AHEAD OF THE
NEXT SYSTEM FOR THE WEEKEND...BUT BEFORE THAT A WEAK TROUGH WILL
IMPACT THE AREA FOR THE END OF THE WEEK.
THE WEAK TROUGH MAY BRING CHANCES FOR RAIN THURSDAY NIGHT AND
FRIDAY...BUT CONFIDENCE IS LOWER DUE TO DISCREPANCIES.
TEMPERATURES WILL STEADILY INCREASE BACK INTO THE 80S...BUT THE
NEXT FRONT WILL APPROACH AND TRAVERSE THE AREA SATURDAY
NIGHT/SUNDAY MORNING. THIS FRONT WILL BRING THE NEXT BEST CHANCE
OF RAIN TO THE REGION. THIS PERIOD HAS HIGHER CONFIDENCE DUE TO
BETTER AGREEMENT ACROSS VARIOUS MODEL SOLUTIONS.
BILLINGS WRIGHT
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 613 AM CDT MON AUG 17 2015
MAIN AVIATION CONCERNS WILL BE CONVECTIVE TRENDS OVER THE NEXT 24
HOURS.
A CLUSTER OF SHOWERS AND STORMS SLOWLY TRACKED SOUTH ACROSS
WESTERN KS OVERNIGHT WITH A REMNANT MCV NOW SITUATED OVER
WESTERN OK. THE COLD FRONT THAT SWEPT ACROSS THE NORTHERN PLAINS
YESTERDAY HAS STARTED TO WASH OUT AND WHAT IS LEFT OF IT CURRENTLY
STRETCHES FROM NORTHEAST IA INTO WESTERN KS. THIS FEATURE WILL
CONTINUE TO WASH OUT TODAY. WITH LACK OF A SURFACE
FOCUS...CONVECTIVE TRENDS TODAY WILL BE TOUGH WITH THE MAIN
FORCING THE RESULT OF INCREASING UPPER DIFFLUENCE AS A WEAK WAVE
APPROACHES. WITH LACK OF CONFIDENCE WILL LEAVE OUT MENTION OF
STORMS TODAY. HOWEVER...CONFIDENCE IN STORMS INCREASES TONIGHT AS
850MB FLOW VEERS WHICH WILL SET UP SOME DECENT 850-700MB MOISTURE
TRANSPORT. SO WILL RUN WITH VCTS AT ALL SITES AFTER 06Z TONIGHT.
LAWSON
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 90 71 84 60 / 40 50 60 70
HUTCHINSON 90 70 85 58 / 40 50 50 60
NEWTON 89 69 84 57 / 40 50 50 70
ELDORADO 90 71 84 58 / 40 50 60 70
WINFIELD-KWLD 91 71 85 60 / 40 50 60 70
RUSSELL 88 66 83 54 / 50 50 60 30
GREAT BEND 89 68 85 55 / 50 50 60 40
SALINA 90 70 85 57 / 40 50 60 50
MCPHERSON 90 70 85 57 / 40 50 50 60
COFFEYVILLE 91 72 86 64 / 20 40 60 70
CHANUTE 90 72 84 61 / 30 40 60 70
IOLA 90 71 83 61 / 30 40 60 70
PARSONS-KPPF 91 71 85 62 / 20 30 60 70
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
318 AM CDT MON AUG 17 2015
.SYNOPSIS...
ISSUED AT 317 AM CDT MON AUG 17 2015
CONVECTION IS DECREASING IN AREAL EXTENT BUT CONTINUING ACROSS
SOUTHWEST KANSAS AND OVER NORTH CENTRAL KANSAS AND NORTHEAST INTO
SOUTHEAST NEBRASKA. THIS SCATTERED CONVECTION IS EXPECTED TO
LINGER...BUT DIMINISH INTO THE EARLY MORNING HOURS.
BILLINGS WRIGHT
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 317 AM CDT MON AUG 17 2015
TODAY - TONIGHT: THE HIGH RESOLUTION GUIDANCE HRRR AND THE HIGHER
RESOLUTION NAM12 STRUGGLE TO SHOW MUCH CONVECTION PERSISTING
ACROSS CENTRAL KANSAS DURING THE EARLY PART OF THE DAY. A PIECE
OF ENERGY WILL APPROACH THE AREA FROM THE NORTHWEST DURING THE
LATE AFTERNOON HOURS WHICH WILL INCREASE THE CHANCES FOR
CONVECTION INTO THE EVENING ESPECIALLY OVER CENTRAL AND SOUTH
CENTRAL KANSAS. SHEAR WILL BE LACKING...BUT THERE IS A MODEST
1000-1500 J/KG CAPE FOR THUNDERSTORMS TO POTENTIALLY BE
STRONG...AND WITH THE WEAK FLOW...FLOODING COULD BE A CONCERN AS
WELL. MOISTURE TRANSPORT INCREASES DURING THE OVERNIGHT HOURS
INCREASING THE PRECIPITATION CHANCES FOR SOUTH CENTRAL KANSAS.
TUESDAY - WEDNESDAY:
THE STRONGER UPPER LEVEL WAVE WILL MOVE INTO THE REGION DURING THE
DAY TUESDAY...BUT THE MAIN FRONTAL PUSH WILL BE LATER TUESDAY
EVENING WHEN THE UPPER LOW DIGS SLIGHTLY DEEPER. THE UPPER PV
ENERGY MOVING ACROSS THE AREA TUESDAY WILL INCREASE THE CHANCE
FOR THUNDERSTORMS THROUGHOUT THE DAY. THE UPPER WAVE WILL BE
CLOSER TO KANSAS INCREASING THE UPPER SHEAR PROFILE. SEVERE STORMS
MAY BE POSSIBLE ESPECIALLY OVER CENTRAL AND NORTHERN PORTIONS OF
SOUTH CENTRAL KANSAS WHERE THE COMBINATION OF SHEAR AND
INSTABILITY ARE ANTICIPATED TO BE THE GREATEST. ELSEWHERE STORMS
COULD BE STRONG.
BY TUESDAY NIGHT THE MAIN COLD FRONT/WIND SHIFT WILL BEGIN MOVING
ACROSS CENTRAL AND EASTERN KANSAS. THUNDERSTORMS ALONG THE FRONT
ARE POSSIBLE...BUT THE CONVERGENCE ISN`T OVERWHELMING. THE FRONT
IS EXPECTED TO BE FAIRLY PROGRESSIVE AND MOVE THROUGH THE AREA BY
EARLY MORNING WEDNESDAY. A FEW STRONGER STORMS REMAIN POSSIBLE
ALONG THE FRONT.
A SECONDARY PIECE OF ENERGY WILL MOVE SOUTHWARD INTO THE UPPER LOW
CAUSING THE POTENTIAL FOR SCATTERED SHOWERS DURING THE DAY
WEDNESDAY.
THE FRONT WILL CAUSE TEMPERATURES ON WEDNESDAY TO BE SIGNIFICANTLY
COOLER THAN RECENT DAYS...STEADILY COOLING FROM A HIGH CLOSE TO
NORMAL TODAY IN THE LOW 90S TO THE LOW TO MID 70S BY WEDNESDAY.
BILLINGS WRIGHT
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 317 AM CDT MON AUG 17 2015
WHILE THERE ARE SOME SLIGHT DISCREPANCIES AMONGST THE MEDIUM
RANGE GUIDANCE...THE PATTERN REMAINS ACTIVE AND GENERALLY IN
FAIRLY GOOD AGREEMENT. ZONAL FLOW WILL RETURN BRIEFLY AHEAD OF THE
NEXT SYSTEM FOR THE WEEKEND...BUT BEFORE THAT A WEAK TROUGH WILL
IMPACT THE AREA FOR THE END OF THE WEEK.
THE WEAK TROUGH MAY BRING CHANCES FOR RAIN THURSDAY NIGHT AND
FRIDAY...BUT CONFIDENCE IS LOWER DUE TO DISCREPANCIES.
TEMPERATURES WILL STEADILY INCREASE BACK INTO THE 80S...BUT THE
NEXT FRONT WILL APPROACH AND TRAVERSE THE AREA SATURDAY
NIGHT/SUNDAY MORNING. THIS FRONT WILL BRING THE NEXT BEST CHANCE
OF RAIN TO THE REGION. THIS PERIOD HAS HIGHER CONFIDENCE DUE TO
BETTER AGREEMENT ACROSS VARIOUS MODEL SOLUTIONS.
BILLINGS WRIGHT
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1105 PM CDT SUN AUG 16 2015
A RELATIVELY LIGHT SOUTHEAST-SOUTHERLY WIND COMPONENT SHOULD
PREVAIL OVERNIGHT INTO MONDAY...TO THE SOUTH OF A FRONTAL
BOUNDARY...EXTENDING FROM FAR SOUTHEAST NEBRASKA ACROSS
NORTHWESTERN KANSAS. SCATTERED WEAK ELEVATED CONVECTION IS
POSSIBLE MONDAY MORNING...ALONG/W OF HIGHWAY 14 IN AN AREA OF
WEAK MOISTURE TRANSPORT. OTHERWISE...BETTER CHANCES FOR
THUNDERSTORMS WILL BE MONDAY NIGHT...AS A WEAK SHORTWAVE EJECTS
OUT OF COLORADO...IN COMBINATION WITH A SOUTHERLY LOW-LEVEL JET
AND ASSOCIATED MOISTURE TRANSPORT.
JMC
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 90 70 86 62 / 10 40 60 70
HUTCHINSON 91 70 86 59 / 20 40 60 60
NEWTON 90 69 85 60 / 10 40 60 70
ELDORADO 91 70 85 61 / 10 40 60 70
WINFIELD-KWLD 92 71 86 63 / 10 40 60 70
RUSSELL 88 67 83 55 / 40 50 60 40
GREAT BEND 89 68 85 56 / 30 50 60 40
SALINA 90 69 85 59 / 30 40 60 60
MCPHERSON 90 69 85 59 / 20 40 60 60
COFFEYVILLE 92 71 86 65 / 10 30 60 70
CHANUTE 91 70 85 64 / 10 30 60 70
IOLA 91 70 84 63 / 20 30 60 70
PARSONS-KPPF 92 71 85 64 / 10 30 60 70
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1153 PM MDT SUN AUG 16 2015
.UPDATE...
ISSUED AT 928 PM MDT SUN AUG 16 2015
UPDATED THE FORECAST FOR TONIGHT BASED ON LATEST RADAR TRENDS AND
MODEL DATA. CURRENT LINE OF STORMS SHOULD BE SOUTH OF THE AREA BY
MIDNIGHT OR SHORTLY AFTER. OVERNIGHT ANOTHER ROUND OF STORMS MAY
MOVE ACROSS THE NORTHERN PART OF THE AREA. HOWEVER AM SOMEWHAT
DOUBTFUL OF THIS SINCE THAT IS BEHIND THE COLD FRONT AND ANY
STORMS THAT HAVE TRIED TO MOVE OVER THE AREA BEHIND THE FRONT HAVE
NOT SURVIVED. LOWERED CHANCES OVERNIGHT SOME TO ACCOUNT FOR THIS
BUT STILL KEPT A MENTION OF RAIN GOING.
UPDATE ISSUED AT 847 PM MDT SUN AUG 16 2015
THE STORM ACTIVITY WHICH PROMPTED THE WATCH HAS MOVED OUT OF THE
WATCH AREA. IN ADDITION NO FURTHER HEAVY RAIN DEVELOPMENT IS
EXPECTED THROUGH THE REST OF THE NIGHT.
UPDATE ISSUED AT 700 PM MDT SUN AUG 16 2015
UPDATED FORECAST TO ACCOUNT FOR STORMS BEING TIED TO THE COLD
FRONT AS IT IS PUSHED SOUTHWARD. EXPECT THESE STORMS TO MOVE
SOUTH THROUGH THE REST OF THE AREA THIS EVENING...AND BE SOUTH OF
THE AREA AN HOUR OR SO AFTER MIDNIGHT.
BEHIND THE FRONT THE COOLER AIR AND LACK OF LIFT HAVE SERVED TO
END ANY STORMS THAT LINGER TOO LONG BEHIND THE FRONT. DO EXPECT
THE STORM ACTIVITY EAST OF HIGHWAY 25 TO CONTINUE INTO MID
EVENING BEFORE MOVING EAST OF THE AREA DUE TO THE NOSE OF THE LOW
LEVEL JET HELPING TO SUSTAIN THOSE STORMS.
TO THE WEST ANOTHER AREA OF STORMS IS SLOWLY MOVING TOWARD THE
AREA. HAVE NOTICED THE LEADING LINE OF STORMS HAS DISSIPATED AS
THEY ENCOUNTER THE FRONT. MODELS SHOW SOME ISENTROPIC OVER THE
WESTERN PORTIONS OF THE AREA...SO WILL HAVE HIGHER CHANCES FOR
RAIN THERE DECLINING TO THE EAST.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH MONDAY)
ISSUED AT 235 PM MDT SUN AUG 16 2015
WV IMAGERY AND RAP ANALYSIS SHOWS RIDGE CENTERED OVER SOUTHERN
CALIFORNIA WITH AXIS EXTENDING ACROSS THE HIGH PLAINS AND INTO THE
GREAT LAKES REGION. PLUMES OF MID LEVEL MOISTURE ORIGINATING IN THE
PACIFIC ARE ROTATING AROUND THE EASTERN AND NORTHERN PERIPHERY OF THE
LARGE SCALE RIDGE INTO THE ROCKIES AND HIGH PLAINS. DIFFLUENT FLOW IS
CURRENTLY IN PLACE ACROSS THE CENTRAL ROCKIES WITH TROUGH DIGGING
INTO THE NORTHERN PLAINS. A FEW WEAKER SHORTWAVE TROUGHS ARE JUST TO
THE WEST/NORTHWEST OF OUR CWA. AT THE SURFACE QUASI-STATIONARY FRONT
CURRENTLY EXTENDS ACROSS CENTRAL NEBRASKA INTO NORTHCENTRAL COLORADO
OVER THE FAR NORTHWEST PART OF OUR CWA. PREFRONTAL TROUGH AXIS IS IN
PLACE FROM SOUTHEAST COLORADO OVER GOODLAND AND NORTON KANSAS.
THIS AFTERNOON-TONIGHT...THUNDERSTORM ACTIVITY SHOULD INITIATE
WITHIN THE NEXT FEW HOURS ALONG FRONT AND SURFACE TROUGH WITH
COVERAGE INCREASING THIS EVENING AS A SERIES OF WEAK SHORTWAVE
TROUGHS ROTATE ACROSS THE REGION. RECENT TRENDS IN ARW/NMM HAVE BEEN
TO SHIFT MOST ORGANIZED THUNDERSTORM CLUSTER TO THE SOUTH ROUGHLY
ALONG AND SOUTH OF INTERSTATE 70. CURRENTLY THE ORIENTATION OF FLOW
ALOFT AND OTHER GUIDANCE STILL SHOWING THUNDERSTORM CLUSTERS
ORIGINATING FROM THE WEST OR NORTHWEST OF THIS. EITHER WAY...DEEP
MOIST AIR MASS AND DECENT INSTABILITY AHEAD OF FRONT WILL SUPPORT
ACTIVITY ACROSS MUCH OF CWA TRANSITIONING EASTWARD. STRONGEST CAPE
AXIS IF FURTHER EAST THAN PREVIOUS GUIDANCE INDICATED...THOUGH THERE
IS ENOUGH ELEVATED CAPE TO AT LEAST CONSIDER POTENTIAL FOR
MARGINALLY SEVERE HAIL. DCAPE 1000-1500 J/KG COINCIDING DRY ADIABATIC
PROFILES BELOW 700MB COULD SUPPORT ISOLATED SEVERE DOWNDRAFT
POTENTIAL DURING THE AFTERNOON...THOUGH AS MIXING RATIOS INCREASE
BELOW 700MB THIS EVENING THIS THREAT WILL LIKELY DIMINISH.
REGARDING FLASH FLOOD WATCH...ANOMALOUSLY HIGH PWAT VALUES 1.2-1.6
WILL ONLY INCREASE THROUGH THE NIGHT APPROACHING 1.7-1.8 WHICH IS
WELL WITHIN 99TH PERCENTILE OR 3 STANDARD DEVIATIONS FROM NORMAL.
WITH VERY SLOW STORM MOTIONS AND POSSIBILITY FOR
TRAINING/BACKBUILDING I AM COMFORTABLE WITH FLASH FLOOD WATCH. IF
ARW/NMM SOLUTION PANS OUT THEN WE MAY NEED TO CONSIDER ADDING
SOUTHERN PART OF FORECAST AREA TO WATCH.
MONDAY...WHILE FRONTAL PASSAGE SHOULD OCCUR FROM NORTH TO SOUTH
MONDAY...GUIDANCE IS SHOWING A LOT OF SPREAD ON TIMING. THIS LOWERS
CONFIDENCE/TIMING OF ADDITIONAL THUNDERSTORM ACTIVITY. ARW/NMM SHOW
A MORE ORGANIZED THUNDERSTORM CLUSTER DEVELOPING ALONG FRONT MONDAY
MORNING...THOUGH OTHER GUIDANCE IS SHOWING PREDOMINANTLY ISOLATED TO
SCATTERED ACTIVITY LINGERING ACROSS THE AREA. DEEP MOIST LAYER
REMAINS IN PLACE...SO WITH POTENTIAL FOR OVERRUNNING ALONG BAROCLINIC
ZONE...IT IS POSSIBLE FOR A MORE ORGANIZED CLUSTER IF WE CONTINUE TO
SEE WEAK HEIGHT FALL...WHICH COULD ALSO RESULT CONTINUING THREAT FOR
FLASH FLOODING. SEVERE THUNDERSTORM THREAT WILL BE HIGHLY DEPENDENT
ON FRONTAL POSITION/TIMING AS BETTER INSTABILITY WILL TEND TO BE
AHEAD OF FRONT. AS WITH TODAY...THREATS WOULD BE LARGE HAIL/DAMAGING
WINDS ALONG/SOUTH OF FRONT.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 252 PM MDT SUN AUG 16 2015
FOR THIS EXTENDED FORECAST PACKAGE...A STRONG COLD FRONT IS EXPECTED
TO MOVE THROUGH ON TUESDAY...BRINGING AN END TO SIGNIFICANT
PRECIPITATION CHANCES AND A TEMPORARY PARDON FROM THE WARMTH AND
HUMIDITY. ZONAL FLOW ALOFT RETURNS BEHIND TUESDAY`S SYSTEM. WITH
SOUTHERLY LOW LEVEL FLOW...A WARMING TREND IS EXPECTED TO BEGIN
THURSDAY. HOWEVER...YET ANOTHER UPPER LEVEL DISTURBANCE IS EXPECTED
TO FORCE A COLD FRONT THROUGH THIS WEEKEND...BRINING ANOTHER CHANCE
FOR BELOW NORMAL TEMPERATURES.
THE MOST IMPACTFUL WEATHER IN THE EXTENDED FORECAST PERIOD IS
ANTICIPATED MONDAY EVENING THROUGH TUESDAY EVENING. ACTIVE WEATHER
IS FORECAST AS A LARGE NEGATIVELY TILTED TROUGH KICKS OUT OVER THE
HIGH PLAINS. STRONG/SEVERE THUNDERSTORMS MAY BE ONGOING ACROSS
PORTIONS OF THE REGION MONDAY EVENING DEPENDING ON THE FRONT
LOCATION AND ENVIRONMENTAL PARAMETERS. ANY POTENTIAL SEVERE WEATHER
THREAT MAY BE HIGHER MONDAY EVENING AS INITIAL DEVELOPMENT IN
COLORADO SHOULD BE MOVING IN. THE PRIMARY THREATS FOR SEVERE WEATHER
WILL BE LARGE HAIL AND DAMAGING WINDS. AS MENTIONED IN THE DAY 2
STORM PREDICTION CENTER OUTLOOK...SURFACE VORTICITY/HELICITY
MAXIMIZED IN THE VICINITY OF THE FRONT MAY PROVIDE AN OPPORTUNITY
FOR A TORNADO TO OCCUR. CONFIDENCE IN THIS ISN`T AS HIGH AS HIGHER
RESOLUTION GUIDANCE INDICATES THE POTENTIAL FOR COLD POOL
DEVELOPMENT...HIGHLIGHTING A HIGHER THREAT OF MCS DEVELOPMENT WITH
DAMAGING WINDS AS THE MAIN THREAT. IN TERMS OF FLASH FLOODING...A
THREAT WILL STILL EXIST ESPECIALLY IF HEAVY RAINS ARE RECEIVED
TONIGHT. PRECIPITABLE WATER VALUES FALL AS THE FRONT DOES FORCE SOME
MOISTURE SOUTH SO WE NO LONGER EXPECT PRECIPITABLE WATER VALUES
NEARING THE 99TH PERCENTILE. STORM MOVEMENT REMAINS QUITE SLOW IN
TERMS OF STEERING WINDS ALOFT SO COLD POOL FORMATION/MOVEMENT SHOULD
BE THE PRIMARY DRIVER. THEREFORE...A FLASH FLOOD THREAT MAY PERSIST
AND ANOTHER FLASH FLOOD WATCH MAY BE NEEDED FOR MONDAY EVENING IN
LATER FORECAST PACKAGES.
ON TUESDAY...THE FRONT SHOULD FINALLY SLIDE ALL THE WAY THROUGH THE
REGION...RESTRICTING HIGHEST INSTABILITY SOUTH OF THE FRONT AND
PRIMARILY SOUTH OF THE REGION. HOWEVER...CONFIDENCE IS LOW ON WHEN
THIS COLD FRONT WILL SURGE SOUTH AND THERE MAY BE ENOUGH TIME FOR
STORM DEVELOPMENT AHEAD OF THE FRONT. THIS WOULD MEAN SEVERE WEATHER
IS POSSIBLE BUT UNLIKELY TUESDAY. HOWEVER...ADDITIONAL PERTURBATIONS
MOVE IN FROM THE NORTHWEST BEHIND THE MAIN FORCING AND WITH SOME
INSTABILITY REMAINING IN THE POST-FRONTAL ENVIRONMENT...THERE SHOULD
BE ADDITIONAL SHOWER/THUNDERSTORM DEVELOPMENT TUESDAY AFTERNOON BUT
COVERAGE AND INTENSITY REMAINS IN DOUBT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1148 PM MDT SUN AUG 16 2015
VFR TO IFR CONDITIONS FORECAST FOR THE 6Z TAFS. LATEST SURFACE
OBSERVATIONS FOR CENTRAL NEBRASKA SHOW LIGHT FOG/IFR CEILINGS
MOVING SOUTHWEST WITH THE LIGHT NORTH WIND. LATEST MODEL DATA HAS
SUPPORTED THESE CONDITIONS MOVING OVER THE TAFS SITES HAVE
LOWERED VISIBILITIES/CEILING ACCORDINGLY. EXPECT THE LOWEST
VISIBILITY TO BE AROUND SUNRISE AS IS TYPICAL. DURING THE MORNING
THE LOW CLOUDS WILL BE VERY SLOW TO LIFT BUT SHOULD BY LATE
MORNING OR EARLY AFTERNOON.
OVERNIGHT THERE WILL BE A CHANCE FOR SOME STORMS TO MOVE OVER
MAINLY KMCK. AT THIS TIME COVERAGE IS TOO SPARSE TO PLACE IN THE
TAF BUT THE BEST TIME LOOKS TO BE AFTER 8Z. COULD BE SOME STORMS
NEAR KMCK MONDAY MORNING BUT WILL KEEP ANY MENTION OUT FOR NOW DUE
TO UNCERTAINTY THAT COVERAGE WILL BE ENOUGH TO WARRANT A MENTION.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...RRH
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
239 PM EDT MON AUG 17 2015
...UPDATED AVIATION DISCUSSION...
.SHORT TERM (NOW THROUGH TUESDAY)...
ISSUED AT 315 AM EDT MON AUG 17 2015
MOISTURE WILL CONTINUE TO ADVECT INTO THE REGION FROM THE SOUTH THIS
PERIOD. AN UPPER LEVEL LOW NOW ALONG THE SOUTHERN IN/IL BORDER WILL
TRAVEL NORTH AND THEN START HEADING NORTHEAST BY LATER THIS
AFTERNOON. ALREADY SEEING SOME LIGHT RADAR RETURNS OVER SOUTH
CENTRAL TN THIS HOUR...IN AN AREA OF ENHANCED LIFT ON THE SOUTH SIDE
OF A WEAK UPPER JET. THESE RAINS SHOULD LIFT NORTHWARD THIS MORNING.
ANOTHER AREA OF SHOWERS SHOULD DEVELOP ALONG THE OHIO RIVER THIS
MORNING...WHERE THE LATEST RAP PLACES A THETA-E RIDGE.
THE CHANCE FOR AFTERNOON THUNDERSTORMS WILL DEPEND PARTLY ON HOW
MANY BREAKS WE GET IN THE CLOUDS TODAY. IT WILL NOT TAKE MUCH...AS
COOLER AIR ALOFT WITH THE PASSAGE OF THE UPPER LOW WILL MEAN SOME
ELEVATED INSTABILITY AS WELL. GIVEN THE CLOUD COVER THOUGH...THINK
THE RISK FOR SEVERE WEATHER IS FAIRLY LOW.
TONIGHT THAT WAVE SHOULD BE HEADING TOWARD NORTHERN OHIO. THAT SAID
THOUGH...IT WILL LEAVE A TRAILING TROUGH THAT MAY ALLOW FOR
CONTINUED STORM DEVELOPMENT OVER THE SOUTHEAST HALF OF OUR FORECAST
AREA. THAT AREA WILL CONTINUE TO SEE THE BEST CHANCES ON TUESDAY.
MAY HAVE TO MONITOR FOR FLOOD THREAT DOWN THERE AS OUR SOUTHEAST
COUNTIES HAVE LOWER FLASH FLOOD GUIDANCE. STILL CURRENT QPF IS WELL
BELOW THAT GUIDANCE, BUT SHOULD LATER FORECASTS TREND UP MORE WE
MAYNEED A WATCH.
CLOUD COVER SHOULD LIMIT HIGH TEMPERATURES TO BELOW NORMAL TODAY AND
TUESDAY...WHEREAS LOWS WILL BE A LITTLE ABOVE NORMAL. ONLY OTHER
CONCERN WOULD BE PATCHY FOG BOTH THIS MORNING AND TOMORROW MORNING,
WITH COVERAGE LIMITED BOTH DAYS ALSO BY CLOUD COVER.
.LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...
ISSUED AT 315 AM EDT MON AUG 17 2015
TUESDAY NIGHT...
WEAK SOUTHWEST FLOW WILL BE IN PLACE AHEAD OF A STRONG NORTH CENTRAL
CONUS TROUGH TO START THE LONG TERM. MAINLY DIURNALLY DRIVEN
SCATTERED T-STORMS ARE EXPECTED TO BE ONGOING ACROSS OUR SE CWA
TUESDAY EVENING, HOWEVER THESE SHOULD GRADUALLY DIMINISH AS WE HEAD
INTO THE OVERNIGHT HOURS. CAN`T GO COMPLETELY DRY AS THERE IS A
SIGNAL FOR SOME LOW LEVEL JETTING THROUGH THE OVERNIGHT. SOUTHERLY
WINDS SHOULD INCREASE TOWARD DAWN, HELPING LOWS TO STAY ON THE MILD
SIDE. LOOK FOR MAINLY LOW 70S.
WEDNESDAY - THURSDAY...
STRONG SHORTWAVE TROUGH AND ITS ASSOCIATED SURFACE LOW WILL MOVE
FROM THE UPPER MIDWEST TO LAKE SUPERIOR BY LATE WEDNESDAY NIGHT.
DEEP MOISTURE WILL POOL INTO THE OHIO RIVER VALLEY AHEAD OF THE
TROUGH AND SURFACE FRONT TRAILING FROM THE LOW. MEANWHILE, STRONGER
DEEP FLOW WILL ALSO OVERSPREAD THE REGION BY WEDNESDAY NIGHT. LOOK
FOR SCATTERED TO NUMEROUS THUNDERSTORMS DURING THE DAY ON WEDNESDAY
WITH HIGHS MAINLY IN THE LOW 80S. A FEW OF THE STORMS COULD BE
STRONG IF MODERATE INSTABILITY IS REALIZED, ALTHOUGH BETTER DEEP
SHEAR AND FORCING DOESN`T ARRIVE UNTIL LATER WEDNESDAY NIGHT. WE`LL
HAVE TO CONTINUE TO KEEP AN EYE ON POTENTIAL FOR AN ORGANIZED SEVERE
THREAT LATER WEDNESDAY EVENING INTO WEDNESDAY NIGHT, ALTHOUGH SOME
LIMITING FACTORS COULD BE TIMING OF PASSAGE/MORE LIMITED INSTABILITY
AND BEST FORCING NORTH OF THE CWA. WILL CONTINUE TO MENTION HEAVY
RAIN AND GUSTY WINDS AS THE MAIN POTENTIAL THREATS IN THE HWO.
COLD FRONT LOOKS TO PASS THROUGH EARLY THURSDAY MORNING ACROSS THE
NW AND THROUGH MOST OF THE CWA BY LATE THURSDAY MORNING. IF PASSAGE
IS SLOW ENOUGH, SOME REDEVLOPMENT COULD OCCUR ACROSS OUR FAR E OR SE
THURSDAY AFTERNOON, WHERE SOME STRONGER/PULSY STORMS WOULD BE
POSSIBLE. OTHERWISE, SKIES WILL BECOME GRADUALLY CLEARER WITH
TEMPERATURES ONLY TOPPING OUT IN THE MID OR UPPER 70S.
THURSDAY NIGHT - SUNDAY...
THE FRONT COULD HANG UP ACROSS OUR SOUTH TO END THE WEEK AND HEAD
INTO THE WEEKEND SO WILL KEEP ISOLATED TO WIDELY SCATTERED CHANCES
ACROSS THE SOUTH THROUGH SATURDAY. THE NORTH WILL BE DRY DURING THIS
TIME CLOSER TO THE SURFACE HIGH CENTER. THURSDAY NIGHT LOWS LOOK TO
DROP INTO THE UPPER 50S NORTH AND LOWER 60S SOUTH THURSDAY NIGHT.
CAN`T RULE OUT A FEW MID 50S IN OUR TYPICAL COOL NORTH SPOTS. HIGHS
ON FRIDAY WILL MODERATE A BIT, FINDING THEIR WAY BACK TO THE LOW
80S. FRIDAY NIGHT WILL BE SLIGHTLY MILDER WITH LOWS BACK IN THE LOW
AND MID 60S. SATURDAY BRINGS HIGHS IN THE LOW AND MID 80S.
STORM CHANCES MAY INCREASE ON SUNDAY AHEAD OF ANOTHER MID LEVEL
DISTURBANCE AND ASSOCIATED SURFACE FRONT. HOWEVER, CONFIDENCE IS LOW
IN TIMING OF THIS FEATURE SO WILL ONLY MENTION LOW CHANCES AT THIS
TIME.
&&
.AVIATION (18Z TAF UPDATE)...
ISSUED AT 238 PM EDT MON AUG 17 2015
LIGHT RAIN WILL CONTINUE IN THE LEX AREA FOR MUCH OF THE AFTERNOON
BUT SHOULDN`T CAUSE MUCH OF A PROBLEM FOR AVIATION. BWG AND SDF
SHOULD REMAIN IN A GAP BETWEEN RAIN TO THE EAST AND SHOWERS/STORMS
TO THE WEST, THOUGH A FEW SHOWERS AT THE AIRPORTS STILL POSSIBLE.
LOW LEVEL MOISTURE IS EXPECTED TO CONDENSE INTO A LOW CEILING LATE
TONIGHT INTO THE MORNING HOURS ON TUESDAY, WITH AT LEAST MVFR FLYING
CONDITIONS EXPECTED.
WINDS THROUGH THE TAF PERIOD WILL BE LIGHT.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
SHORT TERM........RJS
LONG TERM.........BJS
AVIATION..........13
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
840 AM EDT MON AUG 17 2015
...FORECAST UPDATE...
ISSUED AT 840 AM EDT MON AUG 17 2015
DID A QUICK UPDATE TO INCREASE POPS ACROSS THE SOUTH WHERE LIGHT
RAIN IS NOW MOVING IN. MESONET SITES NEAR THE TN BORDER HAVE
RECORDED A HUNDREDTH OR TWO, WITH ADDITIONAL STRONGER REFLECTIVITIES
IN BETWEEN OBSERVATION LOCATIONS.
ALSO ADDED SOME SPRINKLES IN SUB-15% POP AREAS. HAD SOME SPRINKLES
IN THE LOUISVILLE METRO OVER THE PAST HOUR.
.SHORT TERM (NOW THROUGH TUESDAY)...
ISSUED AT 315 AM EDT MON AUG 17 2015
MOISTURE WILL CONTINUE TO ADVECT INTO THE REGION FROM THE SOUTH THIS
PERIOD. AN UPPER LEVEL LOW NOW ALONG THE SOUTHERN IN/IL BORDER WILL
TRAVEL NORTH AND THEN START HEADING NORTHEAST BY LATER THIS
AFTERNOON. ALREADY SEEING SOME LIGHT RADAR RETURNS OVER SOUTH
CENTRAL TN THIS HOUR...IN AN AREA OF ENHANCED LIFT ON THE SOUTH SIDE
OF A WEAK UPPER JET. THESE RAINS SHOULD LIFT NORTHWARD THIS MORNING.
ANOTHER AREA OF SHOWERS SHOULD DEVELOP ALONG THE OHIO RIVER THIS
MORNING...WHERE THE LATEST RAP PLACES A THETA-E RIDGE.
THE CHANCE FOR AFTERNOON THUNDERSTORMS WILL DEPEND PARTLY ON HOW
MANY BREAKS WE GET IN THE CLOUDS TODAY. IT WILL NOT TAKE MUCH...AS
COOLER AIR ALOFT WITH THE PASSAGE OF THE UPPER LOW WILL MEAN SOME
ELEVATED INSTABILITY AS WELL. GIVEN THE CLOUD COVER THOUGH...THINK
THE RISK FOR SEVERE WEATHER IS FAIRLY LOW.
TONIGHT THAT WAVE SHOULD BE HEADING TOWARD NORTHERN OHIO. THAT SAID
THOUGH...IT WILL LEAVE A TRAILING TROUGH THAT MAY ALLOW FOR
CONTINUED STORM DEVELOPMENT OVER THE SOUTHEAST HALF OF OUR FORECAST
AREA. THAT AREA WILL CONTINUE TO SEE THE BEST CHANCES ON TUESDAY.
MAY HAVE TO MONITOR FOR FLOOD THREAT DOWN THERE AS OUR SOUTHEAST
COUNTIES HAVE LOWER FLASH FLOOD GUIDANCE. STILL CURRENT QPF IS WELL
BELOW THAT GUIDANCE, BUT SHOULD LATER FORECASTS TREND UP MORE WE
MAYNEED A WATCH.
CLOUD COVER SHOULD LIMIT HIGH TEMPERATURES TO BELOW NORMAL TODAY AND
TUESDAY...WHEREAS LOWS WILL BE A LITTLE ABOVE NORMAL. ONLY OTHER
CONCERN WOULD BE PATCHY FOG BOTH THIS MORNING AND TOMORROW MORNING,
WITH COVERAGE LIMITED BOTH DAYS ALSO BY CLOUD COVER.
.LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...
ISSUED AT 315 AM EDT MON AUG 17 2015
TUESDAY NIGHT...
WEAK SOUTHWEST FLOW WILL BE IN PLACE AHEAD OF A STRONG NORTH CENTRAL
CONUS TROUGH TO START THE LONG TERM. MAINLY DIURNALLY DRIVEN
SCATTERED T-STORMS ARE EXPECTED TO BE ONGOING ACROSS OUR SE CWA
TUESDAY EVENING, HOWEVER THESE SHOULD GRADUALLY DIMINISH AS WE HEAD
INTO THE OVERNIGHT HOURS. CAN`T GO COMPLETELY DRY AS THERE IS A
SIGNAL FOR SOME LOW LEVEL JETTING THROUGH THE OVERNIGHT. SOUTHERLY
WINDS SHOULD INCREASE TOWARD DAWN, HELPING LOWS TO STAY ON THE MILD
SIDE. LOOK FOR MAINLY LOW 70S.
WEDNESDAY - THURSDAY...
STRONG SHORTWAVE TROUGH AND ITS ASSOCIATED SURFACE LOW WILL MOVE
FROM THE UPPER MIDWEST TO LAKE SUPERIOR BY LATE WEDNESDAY NIGHT.
DEEP MOISTURE WILL POOL INTO THE OHIO RIVER VALLEY AHEAD OF THE
TROUGH AND SURFACE FRONT TRAILING FROM THE LOW. MEANWHILE, STRONGER
DEEP FLOW WILL ALSO OVERSPREAD THE REGION BY WEDNESDAY NIGHT. LOOK
FOR SCATTERED TO NUMEROUS THUNDERSTORMS DURING THE DAY ON WEDNESDAY
WITH HIGHS MAINLY IN THE LOW 80S. A FEW OF THE STORMS COULD BE
STRONG IF MODERATE INSTABILITY IS REALIZED, ALTHOUGH BETTER DEEP
SHEAR AND FORCING DOESN`T ARRIVE UNTIL LATER WEDNESDAY NIGHT. WE`LL
HAVE TO CONTINUE TO KEEP AN EYE ON POTENTIAL FOR AN ORGANIZED SEVERE
THREAT LATER WEDNESDAY EVENING INTO WEDNESDAY NIGHT, ALTHOUGH SOME
LIMITING FACTORS COULD BE TIMING OF PASSAGE/MORE LIMITED INSTABILITY
AND BEST FORCING NORTH OF THE CWA. WILL CONTINUE TO MENTION HEAVY
RAIN AND GUSTY WINDS AS THE MAIN POTENTIAL THREATS IN THE HWO.
COLD FRONT LOOKS TO PASS THROUGH EARLY THURSDAY MORNING ACROSS THE
NW AND THROUGH MOST OF THE CWA BY LATE THURSDAY MORNING. IF PASSAGE
IS SLOW ENOUGH, SOME REDEVLOPMENT COULD OCCUR ACROSS OUR FAR E OR SE
THURSDAY AFTERNOON, WHERE SOME STRONGER/PULSY STORMS WOULD BE
POSSIBLE. OTHERWISE, SKIES WILL BECOME GRADUALLY CLEARER WITH
TEMPERATURES ONLY TOPPING OUT IN THE MID OR UPPER 70S.
THURSDAY NIGHT - SUNDAY...
THE FRONT COULD HANG UP ACROSS OUR SOUTH TO END THE WEEK AND HEAD
INTO THE WEEKEND SO WILL KEEP ISOLATED TO WIDELY SCATTERED CHANCES
ACROSS THE SOUTH THROUGH SATURDAY. THE NORTH WILL BE DRY DURING THIS
TIME CLOSER TO THE SURFACE HIGH CENTER. THURSDAY NIGHT LOWS LOOK TO
DROP INTO THE UPPER 50S NORTH AND LOWER 60S SOUTH THURSDAY NIGHT.
CAN`T RULE OUT A FEW MID 50S IN OUR TYPICAL COOL NORTH SPOTS. HIGHS
ON FRIDAY WILL MODERATE A BIT, FINDING THEIR WAY BACK TO THE LOW
80S. FRIDAY NIGHT WILL BE SLIGHTLY MILDER WITH LOWS BACK IN THE LOW
AND MID 60S. SATURDAY BRINGS HIGHS IN THE LOW AND MID 80S.
STORM CHANCES MAY INCREASE ON SUNDAY AHEAD OF ANOTHER MID LEVEL
DISTURBANCE AND ASSOCIATED SURFACE FRONT. HOWEVER, CONFIDENCE IS LOW
IN TIMING OF THIS FEATURE SO WILL ONLY MENTION LOW CHANCES AT THIS
TIME.
&&
.AVIATION (12Z TAF UPDATE)...
ISSUED AT 640 AM EDT MON AUG 17 2015
IMPRESSIVE PLUME OF MOISTURE STREAMING IN AND WRAPPING INTO AN UPPER
LOW CENTERED SOUTHERN ILLINOIS. LIGHT RAINS ARE STARTING TO FORM
EAST OF THIS FEATURE, WITH A FEW STRONGER CELLS EMBEDDED AND NEAR
KHOP. TIME-HEIGHT SECTIONS STILL ARE NOT SHOWING AS STRONG OF A LIFT
IN ASSOCIATION WITH THIS MOISTURE SO HAVE GONE WITH VICINITY SHOWER
WORDING FOR NOW...THOUGH CANNOT RULE OUT EMBEDDED OCCASIONAL
THUNDER.
CLOUD COVER THROUGH THE DAY SHOULD LIMIT INSTABILITY...BUT WITH
DISTURBANCES RIDING AROUND THE UPPER LOW CANNOT RULE OUT SOME STORMS
THIS AFTERNOON...SO WENT WITH VICINITY STORMS FOR ALL SITES. LOW
CLOUDS SHOULD FILL IN BY LATE IN THE PERIOD...WITH MVFR RESTRICTIONS
POSSIBLE AT KLEX/KSDF AND IFR POSSIBLE AT KBWG.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
UPDATE.........13
SHORT TERM.....RJS
LONG TERM......BJS
AVIATION.......RJS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
641 AM EDT MON AUG 17 2015
...UPDATED AVIATION DISCUSSION...
.SHORT TERM (NOW THROUGH TUESDAY)...
ISSUED AT 315 AM EDT MON AUG 17 2015
MOISTURE WILL CONTINUE TO ADVECT INTO THE REGION FROM THE SOUTH THIS
PERIOD. AN UPPER LEVEL LOW NOW ALONG THE SOUTHERN IN/IL BORDER WILL
TRAVEL NORTH AND THEN START HEADING NORTHEAST BY LATER THIS
AFTERNOON. ALREADY SEEING SOME LIGHT RADAR RETURNS OVER SOUTH
CENTRAL TN THIS HOUR...IN AN AREA OF ENHANCED LIFT ON THE SOUTH SIDE
OF A WEAK UPPER JET. THESE RAINS SHOULD LIFT NORTHWARD THIS MORNING.
ANOTHER AREA OF SHOWERS SHOULD DEVELOP ALONG THE OHIO RIVER THIS
MORNING...WHERE THE LATEST RAP PLACES A THETA-E RIDGE.
THE CHANCE FOR AFTERNOON THUNDERSTORMS WILL DEPEND PARTLY ON HOW
MANY BREAKS WE GET IN THE CLOUDS TODAY. IT WILL NOT TAKE MUCH...AS
COOLER AIR ALOFT WITH THE PASSAGE OF THE UPPER LOW WILL MEAN SOME
ELEVATED INSTABILITY AS WELL. GIVEN THE CLOUD COVER THOUGH...THINK
THE RISK FOR SEVERE WEATHER IS FAIRLY LOW.
TONIGHT THAT WAVE SHOULD BE HEADING TOWARD NORTHERN OHIO. THAT SAID
THOUGH...IT WILL LEAVE A TRAILING TROUGH THAT MAY ALLOW FOR
CONTINUED STORM DEVELOPMENT OVER THE SOUTHEAST HALF OF OUR FORECAST
AREA. THAT AREA WILL CONTINUE TO SEE THE BEST CHANCES ON TUESDAY.
MAY HAVE TO MONITOR FOR FLOOD THREAT DOWN THERE AS OUR SOUTHEAST
COUNTIES HAVE LOWER FLASH FLOOD GUIDANCE. STILL CURRENT QPF IS WELL
BELOW THAT GUIDANCE, BUT SHOULD LATER FORECASTS TREND UP MORE WE
MAYNEED A WATCH.
CLOUD COVER SHOULD LIMIT HIGH TEMPERATURES TO BELOW NORMAL TODAY AND
TUESDAY...WHEREAS LOWS WILL BE A LITTLE ABOVE NORMAL. ONLY OTHER
CONCERN WOULD BE PATCHY FOG BOTH THIS MORNING AND TOMORROW MORNING,
WITH COVERAGE LIMITED BOTH DAYS ALSO BY CLOUD COVER.
.LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...
ISSUED AT 315 AM EDT MON AUG 17 2015
TUESDAY NIGHT...
WEAK SOUTHWEST FLOW WILL BE IN PLACE AHEAD OF A STRONG NORTH CENTRAL
CONUS TROUGH TO START THE LONG TERM. MAINLY DIURNALLY DRIVEN
SCATTERED T-STORMS ARE EXPECTED TO BE ONGOING ACROSS OUR SE CWA
TUESDAY EVENING, HOWEVER THESE SHOULD GRADUALLY DIMINISH AS WE HEAD
INTO THE OVERNIGHT HOURS. CAN`T GO COMPLETELY DRY AS THERE IS A
SIGNAL FOR SOME LOW LEVEL JETTING THROUGH THE OVERNIGHT. SOUTHERLY
WINDS SHOULD INCREASE TOWARD DAWN, HELPING LOWS TO STAY ON THE MILD
SIDE. LOOK FOR MAINLY LOW 70S.
WEDNESDAY - THURSDAY...
STRONG SHORTWAVE TROUGH AND ITS ASSOCIATED SURFACE LOW WILL MOVE
FROM THE UPPER MIDWEST TO LAKE SUPERIOR BY LATE WEDNESDAY NIGHT.
DEEP MOISTURE WILL POOL INTO THE OHIO RIVER VALLEY AHEAD OF THE
TROUGH AND SURFACE FRONT TRAILING FROM THE LOW. MEANWHILE, STRONGER
DEEP FLOW WILL ALSO OVERSPREAD THE REGION BY WEDNESDAY NIGHT. LOOK
FOR SCATTERED TO NUMEROUS THUNDERSTORMS DURING THE DAY ON WEDNESDAY
WITH HIGHS MAINLY IN THE LOW 80S. A FEW OF THE STORMS COULD BE
STRONG IF MODERATE INSTABILITY IS REALIZED, ALTHOUGH BETTER DEEP
SHEAR AND FORCING DOESN`T ARRIVE UNTIL LATER WEDNESDAY NIGHT. WE`LL
HAVE TO CONTINUE TO KEEP AN EYE ON POTENTIAL FOR AN ORGANIZED SEVERE
THREAT LATER WEDNESDAY EVENING INTO WEDNESDAY NIGHT, ALTHOUGH SOME
LIMITING FACTORS COULD BE TIMING OF PASSAGE/MORE LIMITED INSTABILITY
AND BEST FORCING NORTH OF THE CWA. WILL CONTINUE TO MENTION HEAVY
RAIN AND GUSTY WINDS AS THE MAIN POTENTIAL THREATS IN THE HWO.
COLD FRONT LOOKS TO PASS THROUGH EARLY THURSDAY MORNING ACROSS THE
NW AND THROUGH MOST OF THE CWA BY LATE THURSDAY MORNING. IF PASSAGE
IS SLOW ENOUGH, SOME REDEVLOPMENT COULD OCCUR ACROSS OUR FAR E OR SE
THURSDAY AFTERNOON, WHERE SOME STRONGER/PULSY STORMS WOULD BE
POSSIBLE. OTHERWISE, SKIES WILL BECOME GRADUALLY CLEARER WITH
TEMPERATURES ONLY TOPPING OUT IN THE MID OR UPPER 70S.
THURSDAY NIGHT - SUNDAY...
THE FRONT COULD HANG UP ACROSS OUR SOUTH TO END THE WEEK AND HEAD
INTO THE WEEKEND SO WILL KEEP ISOLATED TO WIDELY SCATTERED CHANCES
ACROSS THE SOUTH THROUGH SATURDAY. THE NORTH WILL BE DRY DURING THIS
TIME CLOSER TO THE SURFACE HIGH CENTER. THURSDAY NIGHT LOWS LOOK TO
DROP INTO THE UPPER 50S NORTH AND LOWER 60S SOUTH THURSDAY NIGHT.
CAN`T RULE OUT A FEW MID 50S IN OUR TYPICAL COOL NORTH SPOTS. HIGHS
ON FRIDAY WILL MODERATE A BIT, FINDING THEIR WAY BACK TO THE LOW
80S. FRIDAY NIGHT WILL BE SLIGHTLY MILDER WITH LOWS BACK IN THE LOW
AND MID 60S. SATURDAY BRINGS HIGHS IN THE LOW AND MID 80S.
STORM CHANCES MAY INCREASE ON SUNDAY AHEAD OF ANOTHER MID LEVEL
DISTURBANCE AND ASSOCIATED SURFACE FRONT. HOWEVER, CONFIDENCE IS LOW
IN TIMING OF THIS FEATURE SO WILL ONLY MENTION LOW CHANCES AT THIS
TIME.
&&
.AVIATION (12Z TAF UPDATE)...
ISSUED AT 640 AM EDT MON AUG 17 2015
IMPRESSIVE PLUME OF MOISTURE STREAMING IN AND WRAPPING INTO AN UPPER
LOW CENTERED SOUTHERN ILLINOIS. LIGHT RAINS ARE STARTING TO FORM
EAST OF THIS FEATURE, WITH A FEW STRONGER CELLS EMBEDDED AND NEAR
KHOP. TIME-HEIGHT SECTIONS STILL ARE NOT SHOWING AS STRONG OF A LIFT
IN ASSOCIATION WITH THIS MOISTURE SO HAVE GONE WITH VICINITY SHOWER
WORDING FOR NOW...THOUGH CANNOT RULE OUT EMBEDDED OCCASIONAL
THUNDER.
CLOUD COVER THROUGH THE DAY SHOULD LIMIT INSTABILITY...BUT WITH
DISTURBANCES RIDING AROUND THE UPPER LOW CANNOT RULE OUT SOME STORMS
THIS AFTERNOON...SO WENT WITH VICINITY STORMS FOR ALL SITES. LOW
CLOUDS SHOULD FILL IN BY LATE IN THE PERIOD...WITH MVFR RESTRICTIONS
POSSIBLE AT KLEX/KSDF AND IFR POSSIBLE AT KBWG.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
SHORT TERM........RJS
LONG TERM.........BJS
AVIATION..........RJS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
320 AM EDT MON AUG 17 2015
.SHORT TERM (NOW THROUGH TUESDAY)...
ISSUED AT 315 AM EDT MON AUG 17 2015
MOISTURE WILL CONTINUE TO ADVECT INTO THE REGION FROM THE SOUTH THIS
PERIOD. AN UPPER LEVEL LOW NOW ALONG THE SOUTHERN IN/IL BORDER WILL
TRAVEL NORTH AND THEN START HEADING NORTHEAST BY LATER THIS
AFTERNOON. ALREADY SEEING SOME LIGHT RADAR RETURNS OVER SOUTH
CENTRAL TN THIS HOUR...IN AN AREA OF ENHANCED LIFT ON THE SOUTH SIDE
OF A WEAK UPPER JET. THESE RAINS SHOULD LIFT NORTHWARD THIS MORNING.
ANOTHER AREA OF SHOWERS SHOULD DEVELOP ALONG THE OHIO RIVER THIS
MORNING...WHERE THE LATEST RAP PLACES A THETA-E RIDGE.
THE CHANCE FOR AFTERNOON THUNDERSTORMS WILL DEPEND PARTLY ON HOW
MANY BREAKS WE GET IN THE CLOUDS TODAY. IT WILL NOT TAKE MUCH...AS
COOLER AIR ALOFT WITH THE PASSAGE OF THE UPPER LOW WILL MEAN SOME
ELEVATED INSTABILITY AS WELL. GIVEN THE CLOUD COVER THOUGH...THINK
THE RISK FOR SEVERE WEATHER IS FAIRLY LOW.
TONIGHT THAT WAVE SHOULD BE HEADING TOWARD NORTHERN OHIO. THAT SAID
THOUGH...IT WILL LEAVE A TRAILING TROUGH THAT MAY ALLOW FOR
CONTINUED STORM DEVELOPMENT OVER THE SOUTHEAST HALF OF OUR FORECAST
AREA. THAT AREA WILL CONTINUE TO SEE THE BEST CHANCES ON TUESDAY.
MAY HAVE TO MONITOR FOR FLOOD THREAT DOWN THERE AS OUR SOUTHEAST
COUNTIES HAVE LOWER FLASH FLOOD GUIDANCE. STILL CURRENT QPF IS WELL
BELOW THAT GUIDANCE, BUT SHOULD LATER FORECASTS TREND UP MORE WE
MAYNEED A WATCH.
CLOUD COVER SHOULD LIMIT HIGH TEMPERATURES TO BELOW NORMAL TODAY AND
TUESDAY...WHEREAS LOWS WILL BE A LITTLE ABOVE NORMAL. ONLY OTHER
CONCERN WOULD BE PATCHY FOG BOTH THIS MORNING AND TOMORROW MORNING,
WITH COVERAGE LIMITED BOTH DAYS ALSO BY CLOUD COVER.
.LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...
ISSUED AT 315 AM EDT MON AUG 17 2015
TUESDAY NIGHT...
WEAK SOUTHWEST FLOW WILL BE IN PLACE AHEAD OF A STRONG NORTH CENTRAL
CONUS TROUGH TO START THE LONG TERM. MAINLY DIURNALLY DRIVEN
SCATTERED T-STORMS ARE EXPECTED TO BE ONGOING ACROSS OUR SE CWA
TUESDAY EVENING, HOWEVER THESE SHOULD GRADUALLY DIMINISH AS WE HEAD
INTO THE OVERNIGHT HOURS. CAN`T GO COMPLETELY DRY AS THERE IS A
SIGNAL FOR SOME LOW LEVEL JETTING THROUGH THE OVERNIGHT. SOUTHERLY
WINDS SHOULD INCREASE TOWARD DAWN, HELPING LOWS TO STAY ON THE MILD
SIDE. LOOK FOR MAINLY LOW 70S.
WEDNESDAY - THURSDAY...
STRONG SHORTWAVE TROUGH AND ITS ASSOCIATED SURFACE LOW WILL MOVE
FROM THE UPPER MIDWEST TO LAKE SUPERIOR BY LATE WEDNESDAY NIGHT.
DEEP MOISTURE WILL POOL INTO THE OHIO RIVER VALLEY AHEAD OF THE
TROUGH AND SURFACE FRONT TRAILING FROM THE LOW. MEANWHILE, STRONGER
DEEP FLOW WILL ALSO OVERSPREAD THE REGION BY WEDNESDAY NIGHT. LOOK
FOR SCATTERED TO NUMEROUS THUNDERSTORMS DURING THE DAY ON WEDNESDAY
WITH HIGHS MAINLY IN THE LOW 80S. A FEW OF THE STORMS COULD BE
STRONG IF MODERATE INSTABILITY IS REALIZED, ALTHOUGH BETTER DEEP
SHEAR AND FORCING DOESN`T ARRIVE UNTIL LATER WEDNESDAY NIGHT. WE`LL
HAVE TO CONTINUE TO KEEP AN EYE ON POTENTIAL FOR AN ORGANIZED SEVERE
THREAT LATER WEDNESDAY EVENING INTO WEDNESDAY NIGHT, ALTHOUGH SOME
LIMITING FACTORS COULD BE TIMING OF PASSAGE/MORE LIMITED INSTABILITY
AND BEST FORCING NORTH OF THE CWA. WILL CONTINUE TO MENTION HEAVY
RAIN AND GUSTY WINDS AS THE MAIN POTENTIAL THREATS IN THE HWO.
COLD FRONT LOOKS TO PASS THROUGH EARLY THURSDAY MORNING ACROSS THE
NW AND THROUGH MOST OF THE CWA BY LATE THURSDAY MORNING. IF PASSAGE
IS SLOW ENOUGH, SOME REDEVLOPMENT COULD OCCUR ACROSS OUR FAR E OR SE
THURSDAY AFTERNOON, WHERE SOME STRONGER/PULSY STORMS WOULD BE
POSSIBLE. OTHERWISE, SKIES WILL BECOME GRADUALLY CLEARER WITH
TEMPERATURES ONLY TOPPING OUT IN THE MID OR UPPER 70S.
THURSDAY NIGHT - SUNDAY...
THE FRONT COULD HANG UP ACROSS OUR SOUTH TO END THE WEEK AND HEAD
INTO THE WEEKEND SO WILL KEEP ISOLATED TO WIDELY SCATTERED CHANCES
ACROSS THE SOUTH THROUGH SATURDAY. THE NORTH WILL BE DRY DURING THIS
TIME CLOSER TO THE SURFACE HIGH CENTER. THURSDAY NIGHT LOWS LOOK TO
DROP INTO THE UPPER 50S NORTH AND LOWER 60S SOUTH THURSDAY NIGHT.
CAN`T RULE OUT A FEW MID 50S IN OUR TYPICAL COOL NORTH SPOTS. HIGHS
ON FRIDAY WILL MODERATE A BIT, FINDING THEIR WAY BACK TO THE LOW
80S. FRIDAY NIGHT WILL BE SLIGHTLY MILDER WITH LOWS BACK IN THE LOW
AND MID 60S. SATURDAY BRINGS HIGHS IN THE LOW AND MID 80S.
STORM CHANCES MAY INCREASE ON SUNDAY AHEAD OF ANOTHER MID LEVEL
DISTURBANCE AND ASSOCIATED SURFACE FRONT. HOWEVER, CONFIDENCE IS LOW
IN TIMING OF THIS FEATURE SO WILL ONLY MENTION LOW CHANCES AT THIS
TIME.
&&
.AVIATION (06Z TAF UPDATE)...
ISSUED AT 140 AM EDT MON AUG 17 2015
IMPRESSIVE PLUME OF MOISTURE STREAMING IN AND WRAPPING INTO AN UPPER
LOW CENTERED OVER THE WABASH VALLEY. NOT QUITE SEEING ANY RAIN FORM
OUT OF THIS FLOW BUT IT SHOULD START IN FROM THE SOUTH BY
DAYBREAK...WITH THE BEST CHANCE FOR SHOWERS AT KBWG BY 11Z. SOME
LIGHT VSBY RESTRICTIONS MAY PRECEDE THAT BASED ON RAIN THAT FELL
THERE YESTERDAY. TIME-HEIGHT SECTIONS ARE NOT SHOWING AS STRONG OF A
LIFT IN ASSOCIATION WITH THIS MOISTURE SO HAVE GONE WITH VICINITY
SHOWER WORDING FOR NOW...THOUGH CANNOT RULE OUT EMBEDDED OCCASIONAL
THUNDER. GUIDANCE ALSO WAS IN THE 10 PERCENT RANGE FOR LIGHTNING
ACTIVITY.
CLOUD COVER THROUGH THE DAY SHOULD LIMIT INSTABILITY...BUT WITH
DISTURBANCES RIDING AROUND THE UPPER LOW CANNOT RULE OUT SOME STORMS
THIS AFTERNOON...SO WENT WITH PROB30 GROUPS FOR ALL SITES. LOW
CLOUDS SHOULD FILL IN BY LATE IN THE PERIOD...WITH MVFR RESTRICTIONS
POSSIBLE.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
SHORT TERM........RJS
LONG TERM.........BJS
AVIATION..........RJS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
619 PM EDT MON AUG 17 2015
.SYNOPSIS...
WARM...HUMID...AND UNSETTLED WEATHER IS EXPECTED THROUGH MUCH OF
THE WEEK UNTIL THE PASSAGE OF A COLD FRONT THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
WITH 615PM UPDATE...ADJUSTED HOURLY TEMPERATURE TRENDS AS TEMPS
HAVE STAYED UP A FEW DEGREES DESPITE DIURNAL CU. ALSO ADJUSTED SKY
COVER AS OVERCAST MID LEVEL CLOUDS ARE GENERALLY WEST OF THE
FORECAST AREA AND DIURNAL CUMULUS IS ALREADY STARTING TO
DISSIPATE. 18Z NAM/GFS HAVE STARTED COMING IN THE DIRECTION OF THE
HRRR...WHICH WAS PREVIOUSLY NOTED AS HAVING GREATER PRECIPITATION
COVERAGE. HAVE NOT MADE ANY ADJUSTMENTS TO THAT PORTION OF THE
FORECAST YET...BUT WILL CONTINUE TO MONITOR UPSTREAM PRECIPITATION
TRENDS. PREVIOUS DISCUSSION FOLLOWS.
VERY SMALL ADJUSTMENTS MADE TO THE FORECAST THROUGH THE AFTERNOON
AS LOW PRESSURE...APPARENT IN VISIBLE AND WV SATELLITE IMAGERY
OVER ILLINOIS...GETS ABSORBED IN THE UPPER LEVEL FLOW. WHILE LOW
LEVEL MOISTURE WILL INCREASE AHEAD OF THIS APPROACHING WAVE...WARM
AIR ALOFT AND LITTLE SUPPORT FOR LIFT SHOULD KEEP MUCH OF THE
FORECAST AREA DRY TODAY...SAVE FOR SOME CONVECTION OVER THE HIGHER
TERRAIN AND WITH THE LAKE BREEZE. WITH THIS IN MIND...LOW CHANCE
POPS WERE MAINTAINED. WEAK SHEAR WILL KEEP ANY STORMS BELOW SEVERE
THRESHOLDS.
THE AFOREMENTIONED SHORTWAVE WILL PIVOT ACROSS THE UPPER OHIO
VALLEY OVERNIGHT. WHILE WE WILL LOSE MOST OF THE
INSTABILITY...THIN ELEVATED CAPE OVERNIGHT ON THE BUFKIT SOUNDINGS
WARRANTED AT LEAST A SLIGHT CHANCE THUNDER MENTION. THE HRRR IS
MOST AGGRESSIVE WITH THE PRECIPITATION COVERAGE VERSUS THE OTHER
HI RES MODELS OVERNIGHT. CONSIDERING THE LACK OF UPPER LEVEL JET
SUPPORT...WILL KEEP POPS IN THE CHANCE CATEGORY BUT ADJUST TIMING
CLOSE TO THE HRRR. LINGERING CLOUD COVER SHOULD KEEP TEMPERATURES
ELEVATED OVERNIGHT.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
DEEPENING UPPER TROUGH AND STRENGTHENING SURFACE LOW OVER THE
NORTHERN PLAINS WILL CONTINUE THE FEED WARMTH AND MOISTURE IN
SOUTHWEST FLOW UNTIL A COLD FRONT APPROACHES ON THURSDAY.
THUS...WHILE THE UPPER SHORTWAVE ON TUESDAY WILL BE DEPARTING TO
THE EAST...WILL KEEP A CHANCE FOR SHOWERS AND THUNDERSTORMS
THROUGH THE AFTERNOON AND ADDITIONAL CHANCES ON WEDNESDAY WITH YET
ANOTHER SHORTWAVE. WARM AIR ALOFT SHOULD HOLD MOST STORMS BELOW
SEVERE LEVELS UNTIL THE COLD FRONT APPROACHES.
LATEST MODEL GUIDANCE DIFFERS WITH THE TIMING OF THE FRONTAL
PASSAGE ON THURSDAY WHICH WOULD HAVE IMPLICATIONS ON THE STRENGTH
OF ANY CONVECTION OUT AHEAD OF IT. REGARDLESS...LATE WEDNESDAY AND
THURSDAY LOOK TO BE THE BETTER DAYS FOR INSTABILITY AND
SHEAR...WHICH PROMPTED A MARGINAL RISK FOR SEVERE OVER OUR OHIO
ZONES...CLOSER TO THE UPPER LEVEL JET. WILL CONTINUE TO MONITOR
THIS RISK AS THE FRONT APPROACHES.
TEMPERATURES SHOULD STAY CLOSE TO SEASONAL AVERAGES THROUGH THE
PERIOD.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
COLD FRONT PASSAGE IS PROGGED FOR LATE THURSDAY AND AFTER THIS
TIME MORE SEASONABLE CONDITIONS ARE ANTICIPATED. LATEST GUIDANCE
THEN KEEPS THE REGION DRY THROUGH THE REMAINDER OF THE LONG TERM.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
HIGH PRESSURE SLIDING EAST OF THE AREA AS AN UPPER-LEVEL TROF SLOWLY
APPROACHES FROM THE SOUTHWEST. ABUNDANT MIDDAY SUN HAS LED TO
ANOTHER DIURNAL CU-FIELD TO DEVELOP AND EVEN A FEW POP-UP SHOWERS
AND THUNDERSTORMS THROUGH CENTRAL OHIO. ALTHOUGH WEAK WIND SHEAR
THROUGH THE COLUMN WILL BE LIMITING...THE BETTER INSTABILITY OVER
OUR AREA MAY RESULT IN A FEW ISOLATED SHOWERS/THUNDERSTORMS
THROUGH THE EVENING...COVERAGE WILL BE TOO LIMITED FOR INCLUSION
IN ANY TAF CURRENTLY.
THE CLOSED UPPER-LEVEL TROF...CURRENTLY OVER THE LOWER OHIO RIVER
VALLEY WILL MOVE NORTHEAST TONIGHT SPREADING SHOWERS AND POSSIBLY
A FEW EMBEDDED THUNDERSTORMS ACROSS THE FORECAST AREA. TIMING HAS
BEEN A LITTLE TRICKY AS THE UPPER LOW TRANSITIONS TO AN OPEN
WAVE...BUT THE BEST CHANCE OF RAIN AND ANY ASSOCIATED RESTRICTIONS
WILL BE LATE IN THE OVERNIGHT AND EARLY TUESDAY MORNING. EXPECTING
LINGERING SHOWERS AND POSSIBLY THUNDERSTORMS BEHIND THE MAIN WAVE
THROUGH TUESDAY...ALTHOUGH RESTRICTIONS SHOULD REMAIN FAIRLY
LIMITED.
TAX
OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
THE NEXT CHANCE FOR GENERAL RESTRICTIONS IS EXPECTED WITH A LATE
WEDNESDAY/THURSDAY COLD FRONT APPROACH AND PASSAGE.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
214 PM EDT MON AUG 17 2015
.SYNOPSIS...
WARM...HUMID...AND UNSETTLED WEATHER IS EXPECTED THROUGH MUCH OF
THE WEEK UNTIL THE PASSAGE OF A COLD FRONT THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
VERY SMALL ADJUSTMENTS MADE TO THE FORECAST THROUGH THE AFTERNOON
AS LOW PRESSURE...APPARENT IN VISIBLE AND WV SATELLITE IMAGERY
OVER ILLINOIS...GETS ABSORBED IN THE UPPER LEVEL FLOW. WHILE LOW
LEVEL MOISTURE WILL INCREASE AHEAD OF THIS APPROACHING WAVE...WARM
AIR ALOFT AND LITTLE SUPPORT FOR LIFT SHOULD KEEP MUCH OF THE
FORECAST AREA DRY TODAY...SAVE FOR SOME CONVECTION OVER THE HIGHER
TERRAIN AND WITH THE LAKE BREEZE. WITH THIS IN MIND...LOW CHANCE
POPS WERE MAINTAINED. WEAK SHEAR WILL KEEP ANY STORMS BELOW SEVERE
THRESHOLDS.
THE AFOREMENTIONED SHORTWAVE WILL PIVOT ACROSS THE UPPER OHIO
VALLEY OVERNIGHT. WHILE WE WILL LOSE MOST OF THE
INSTABILITY...THIN ELEVATED CAPE OVERNIGHT ON THE BUFKIT SOUNDINGS
WARRANTED AT LEAST A SLIGHT CHANCE THUNDER MENTION. THE HRRR IS
MOST AGGRESSIVE WITH THE PRECIPITATION COVERAGE VERSUS THE OTHER
HI RES MODELS OVERNIGHT. CONSIDERING THE LACK OF UPPER LEVEL JET
SUPPORT...WILL KEEP POPS IN THE CHANCE CATEGORY BUT ADJUST TIMING
CLOSE TO THE HRRR. LINGERING CLOUD COVER SHOULD KEEP TEMPERATURES
ELEVATED OVERNIGHT.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
DEEPENING UPPER TROUGH AND STRENGTHENING SURFACE LOW OVER THE
NORTHERN PLAINS WILL CONTINUE THE FEED WARMTH AND MOISTURE IN
SOUTHWEST FLOW UNTIL A COLD FRONT APPROACHES ON THURSDAY.
THUS...WHILE THE UPPER SHORTWAVE ON TUESDAY WILL BE DEPARTING TO
THE EAST...WILL KEEP A CHANCE FOR SHOWERS AND THUNDERSTORMS
THROUGH THE AFTERNOON AND ADDITIONAL CHANCES ON WEDNESDAY WITH YET
ANOTHER SHORTWAVE. WARM AIR ALOFT SHOULD HOLD MOST STORMS BELOW
SEVERE LEVELS UNTIL THE COLD FRONT APPROACHES.
LATEST MODEL GUIDANCE DIFFERS WITH THE TIMING OF THE FRONTAL
PASSAGE ON THURSDAY WHICH WOULD HAVE IMPLICATIONS ON THE STRENGTH
OF ANY CONVECTION OUT AHEAD OF IT. REGARDLESS...LATE WEDNESDAY AND
THURSDAY LOOK TO BE THE BETTER DAYS FOR INSTABILITY AND
SHEAR...WHICH PROMPTED A MARGINAL RISK FOR SEVERE OVER OUR OHIO
ZONES...CLOSER TO THE UPPER LEVEL JET. WILL CONTINUE TO MONITOR
THIS RISK AS THE FRONT APPROACHES.
TEMPERATURES SHOULD STAY CLOSE TO SEASONAL AVERAGES THROUGH THE
PERIOD.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
COLD FRONT PASSAGE IS PROGGED FOR LATE THURSDAY AND AFTER THIS
TIME MORE SEASONABLE CONDITIONS ARE ANTICIPATED. LATEST GUIDANCE
THEN KEEPS THE REGION DRY THROUGH THE REMAINDER OF THE LONG TERM.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
HIGH PRESSURE SLIDING EAST OF THE AREA AS AN UPPER-LEVEL TROF SLOWLY
APPROACHES FROM THE SOUTHWEST. ABUNDANT MIDDAY SUN HAS LED TO
ANOTHER DIURNAL CU-FIELD TO DEVELOP AND EVEN A FEW POP-UP SHOWERS
AND THUNDERSTORMS THROUGH CENTRAL OHIO. ALTHOUGH WEAK WIND SHEAR
THROUGH THE COLUMN WILL BE LIMITING...THE BETTER INSTABILITY OVER
OUR AREA MAY RESULT IN A FEW ISOLATED SHOWERS/THUNDERSTORMS
THROUGH THE EVENING...COVERAGE WILL BE TOO LIMITED FOR INCLUSION
IN ANY TAF CURRENTLY.
THE CLOSED UPPER-LEVEL TROF...CURRENTLY OVER THE LOWER OHIO RIVER
VALLEY WILL MOVE NORTHEAST TONIGHT SPREADING SHOWERS AND POSSIBLY
A FEW EMBEDDED THUNDERSTORMS ACROSS THE FORECAST AREA. TIMING HAS
BEEN A LITTLE TRICKY AS THE UPPER LOW TRANSITIONS TO AN OPEN
WAVE...BUT THE BEST CHANCE OF RAIN AND ANY ASSOCIATED RESTRICTIONS
WILL BE LATE IN THE OVERNIGHT AND EARLY TUESDAY MORNING. EXPECTING
LINGERING SHOWERS AND POSSIBLY THUNDERSTORMS BEHIND THE MAIN WAVE
THROUGH TUESDAY...ALTHOUGH RESTRICTIONS SHOULD REMAIN FAIRLY
LIMITED.
TAX
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...
THE NEXT CHANCE FOR GENERAL RESTRICTIONS IS EXPECTED WITH A LATE
WEDNESDAY/THURSDAY COLD FRONT APPROACH AND PASSAGE.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
754 PM EDT TUE AUG 18 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 335 PM EDT TUE AUG 18 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
FROM NRN HUDSON BAY INTO THE NRN PLAINS RESULTING IN A WSW FLOW INTO
THE NRN GREAT LAKES. A LINGERNIG AREA OF 700 MB FGEN AND WEAK
WAA/ISENTROPIC LIFT CONTINUES TO SUPPORT A PERSISTENT CLUSTER OF
SHOWERS OVER SCNTRL UPPER MI INTO EARLY AFTERNOON. UPSTREAM A
VIGOROUS SHRTWV ROTATING OVER SD/NE WILL LIFT TOWARD THE UPPER GREAT
LAKES TONIGHT BRINGING SHRA TO UPPER MI MAINLY TONIGHT INTO EARLY
WED. AT THE SFC...A WEAK FRONTAL BOUNDARY EXTENDED FROM CNTRL IA
THROUGH CNTRAL WI INTO CNTRL LWR MI. WITH HIGH PRES OVER NRN
ONTARIO...LIGHT NE WINDS PREVAILED ACROSS THE NRN LAKES TODAY.
TONIGHT...ATTENTION TURNS TO THE DEVELOPING UNSEASONABLY STRONG LOW
PRES SYSTEM MOVING OUT OF THE PLAINS. THE SD/NE SHRTWV WILL SUPPORT
A DEEPENING LOW MOVING INTO SRN MN BY 00Z/WED AND THEN INTO NRN
WI/SW U.P. BY 12Z/WED AS THE CENTRAL PRESSURE LOWERS NEAR 995 MB
APPROACHING RECORD LEVELS FOR THIS TIME OF YEAR. STRONG MOISTURE
TRANSPORT AND 305K-310K ISENTROPIC ASCENT WILL BRING AN AREA OF RAIN
THROUGH UPPER MI TONIGHT...MAINLY AFTER MIDNIGHT. HOWEVER...THIS
TRANSIENT BAND IS EXPECTED TO BRING QPF AMOUNTS OF ONLY 0.25-0.40
INCHES OVER THE CNTRL AND ERN CWA. THE FAR WEST HAS THE POTENTIAL TO
GET HIGHER AMOUNTS (0.5 TO ONE INCH) CLOSER TO THE STRONGEST DEEP
LAYER QVECTOR CONV AND LIFT WHICH WILL REMAIN TO THE WEST OVER NRN MN
AND WRN LAKE SUPERIOR. WITH MODEST MUCAPE VALUES INTO THE 200- 500
J/KG RANGE ONLY ISOLD TSRA ARE EXPECTED.
WEDNESDAY...SHOWERS WILL BE EXITING N AND E WED MORNING AHEAD OF THE
COLD FRONT AND THEN THE DRY SLOT WITH THE SYSTEM WILL MOVE IN FROM
THE SW WED LATE MORNING/AFTERNOON. ALTHOUGH THERE WILL BE STRONG 0-6
KM SHEAR ALONG THE FRONTAL BOUNDARY...AMOUNT OF INSTABILITY (MODELS
PROJECT 300-600 J/KG) REMAINS IN QUESTION AS THERE COULD BE
CONSIDERABLE CLOUD COVER LINGERING OVER THE AREA. BUT IF SUFFICIENT
INSTABILITY DEVELOPS AHEAD/ALONG THE FRONT...THERE COULD BE SOME
STRONG TO POSSIBLY SEVERE STORMS FORMING OVER MAINLY THE CENTRAL AND
ERN CWA IN THE MORNING. AFTER THE DRY SLOT MOVES INTO MAINLY THE
CENTRAL AND ERN CWA EXPECT SHRA TO GENERALLY DISSIPATE IN THE
AFTERNOON. WRAP AROUND PRECIP/MOISTURE WITH SYSTEM COULD MOVE INTO
WRN UPPER MI LATE IN THE DAY. WED LOOKS WINDY OVER CENTRAL AND ERN
UPPER MI WITH S-SW WINDS GUSTING TO 25-30 MPH.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 251 PM EDT TUE AUG 18 2015
THE ANOMALOUS UPPER TROUGH AND SURFACE LOW (AROUND 3-4 SIGMA) WILL
BE CENTERED BETWEEN DULUTH AND ISLE ROYALE AT THE START OF THE LONG
TERM FORECAST. THESE FEATURES WILL BE SLOWLY LIFTING TO THE
NORTHEAST THROUGH THURSDAY...BRINGING THE POTENTIAL FOR RAIN
SHOWERS AND BREEZY CONDITIONS TO THE AREA DURING THAT PERIOD.
STARTING OFF THE PERIOD...THE MID LEVEL DRY SLOT WILL BE OVER THE
CENTRAL AND EASTERN U.P. AND DON/T EXPECT MUCH MORE THAN LOW CLOUDS
FOR THE EVENING. BUT OVER THE WEST...WRAP AROUND MOISTURE WILL LEAD
TO SCATTERED/NUMEROUS SHOWERS WILL BE OCCURRING AND WILL LIKELY SEE
SOME ASSISTANCE FROM TERRAIN ENHANCEMENT WITH THE WEST-NORTHWEST
WINDS BEHIND THE SURFACE TROUGH THAT WILL BE LOCATED OVER THE
CENTRAL U.P. AT 06Z THURSDAY. AS THAT LOW LIFTS TO THE NORTHEAST
OVERNIGHT WEDNESDAY INTO THURSDAY...EXPECT THE SHOWERS TO SHIFT
EASTWARD BEHIND THE TROUGH AND MOVE OVER THE CENTRAL/EASTERN U.P.
ACCUMULATIONS WILL BE LIGHTER THAN OVER THE WEST WITH LESS TERRAIN
INFLUENCE...BUT SHOULD STILL SEE A FEW HUNDREDTHS BY LATE THURSDAY
AFTERNOON. WITH THE UPPER LOW QUICKLY MOVING TO THE NORTH THURSDAY
AFTERNOON INTO THURSDAY NIGHT...SHOULD SEE THE SHOWER COVERAGE
QUICKLY DIMINISH AS DRIER AIR ASSOCIATED WITH A SURFACE RIDGE MOVING
NORTHEAST INTO THE AREA. HAVE FOLLOWED THAT IDEA BOTH WITH THE POPS
AND CLOUD COVER THURSDAY AFTERNOON AND EVENING. IN FACT...SOME OF
THE AREAS NEAR THE WISCONSIN BORDER MAY HAVE THE LOW CLOUDS SCATTER
OUT BY EARLY AFTERNOON. IN ADDITION TO THE RAIN...EXPECT WINDS TO
INCREASE OVER AT LEAST THE WESTERN HALF OF THE CWA ON WEDNESDAY
NIGHT. THE DIFFERENCES IN THE MODELS LEADS TO SOME UNCERTAINTY IN
THE STRENGTH...BUT IT STILL APPEARS THAT GUSTS UP TO 30KTS ARE
POSSIBLE OVER THE KEWEENAW. FOR THE REST OF THE AREA...EXPECT GUSTS
IN THE 20-25KT RANGE ON THURSDAY.
THE HIGH PRESSURE RIDGE WILL BE NEAR THE AREA (FROM A HIGH IN THE
OHIO RIVER VALLEY) THROUGH FRIDAY NIGHT...BUT EXPECT THE GRADIENT
TO TIGHTEN THROUGH THAT PERIOD AS ANOTHER LOW DEVELOPS IN THE
NORTHERN PLAINS. THAT GRADIENT AND PLENTY OF SUNSHINE SHOULD LEAD TO
DECENT MIXING ON FRIDAY (AROUND 800MB)...RAISING TEMPERATURES TO
NORMAL OR SLIGHTLY ABOVE NORMAL VALUES UNDER OCCASIONALLY GUSTY
SOUTHWESTERLY WINDS (17-23KTS). WITH THE UPPER TROUGH AND SURFACE
LOW STILL NEAR THE NORTHERN PLAINS AND MOVING INTO THE UPPER
MISSISSIPPI VALLEY...EXPECT A SIMILAR DAY ON SATURDAY. HAVE REMOVED
THE POPS OVER THE WEST FOR SATURDAY AND WILL KEEP SKIES MOSTLY
SUNNY. SINCE THE TIGHTENING GRADIENT WILL REMAIN IN PLACE AHEAD OF
THE LOW...EXPECT WINDS TO BE A LITTLE GUSTIER THAN FRIDAY (UP TO
25KTS) AND TEMPERATURES TO BE A FEW DEGREES WARMER.
THE UPPER TROUGH FOR THE SECOND HALF OF THE WEEKEND
WILL MOVE THROUGH THE UPPER GREAT LAKES REGION OVERNIGHT SATURDAY
THROUGH SUNDAY EVENING. MEANWHILE...THE SURFACE LOW WILL LIFT
NORTH-NORTHEAST FROM NORTHWEST MINNESOTA TO FAR NORTHERN ONTARIO.
THIS WILL LEAD TO A SHARP COLD FRONT MOVING EAST ACROSS THE AREA ON
SUNDAY. MODELS SEEM TO BE FOCUSING ON LATE SATURDAY NIGHT AND
SUNDAY MORNING FOR THE FRONT TO MOVE THROUGH AND WILL FOCUS THE
HIGHEST POPS DURING THAT PERIOD (LOW LIKELY) AND QUICKLY RAMP
UP/DOWN ON BOTH SIDES. MODELS NOT SHOWING A WHOLE LOT OF INSTABILITY
AHEAD OF THE FRONT (MUCAPE VALUES ONLY UP TO 500 J/KG)...SO THINK
THAT THE THUNDER THREAT WILL BE LIMITED AND WILL CAP AT CHANCES.
THE COLD FRONT WILL USHER IN ANOTHER PERIOD OF BELOW NORMAL
TEMPERATURES FOR THE START OF NEXT WEEK AS HIGH PRESSURE BUILDS
OVER THE AREA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 753 PM EDT TUE AUG 18 2015
UNUSUALLY DEEP LOW PRES FOR AUG WILL MOVE FROM SW MN TO WRN LAKE
SUPERIOR DURING THIS FCST PERIOD. ABUNDANT MOISTURE AND SHRA
STREAMING N WITH THIS SYSTEM WILL LEAD TO CONDITIONS DETERIORATING
TO IFR AT KIWD/KCMX/KSAW BY 06Z. LIFR CONDITIONS APPEAR LIKELY AT
ALL TERMINALS OVERNIGHT AHEAD OF WARM FRONT LIFTING N. PASSAGE OF
OCCLUDING FRONT WILL THEN BRING IMPROVING CONDITIONS TUE
MORNING/EARLY AFTN. FARTHER FROM SFC LOW...KCMX AND ESPECIALLY KSAW
ARE LIKELY TO SEE BETTER DRYING AND POTENTIAL FOR IMPROVEMENT TO VFR
IN THE AFTN THAN KIWD. WINDS WILL BECOME GUSTY AFTER FROPA TUE...
ESPECIALLY AT KSAW WHERE GUSTS TO AROUND 25KT ARE EXPECTED.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 327 PM EDT TUE AUG 18 2015
AS LOW PRES ORGANIZES AND STRENGTHENS OVER THE PLAINS THIS EVENING
...NE WINDS WILL BEGIN TO INCREASE...ESPECIALLY OVER WRN LAKE
SUPERIOR WHERE GUSTS SHOULD REACH 30KT LATE AFTN/EARLY EVENING. MAY
EVEN BE A FEW GALE GUSTS NEAR APOSTLE ISLANDS EARLY EVENING. THIS
LOW WILL BECOME UNSEASONABLY DEEP FOR AUG AS IT LIFTS ACROSS WRN
LAKE SUPERIOR WED AFTERNOON. 20-30KT WINDS ARE EXPECTED OVER MUCH OF
THE LAKE TONIGHT INTO WED. MAY SEE GALE FORCE GUSTS OVER FAR WRN
LAKE SUPERIOR IN THE NE WINDS AHEAD OF THE LOW TONIGHT AND THEN IN
THE WESTERLY WINDS ACROSS WRN AND CENTRAL LAKE SUPERIOR ON THU AS
THE LOW LIFTS N OF THE AREA. WINDS WILL DIMINISH TO UNDER 20KT BY
FRI...AND THEN BEGIN TO INCREASE SOME AGAIN ON SAT AHEAD OF THE NEXT
COLD FRONT MOVING OUT ACROSS THE PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
702 PM EDT MON AUG 17 2015
.AVIATION...
WIDELY SCATTERED SHRAS/TSRAS WILL FADE AFTER 01Z WITH LOSS OF
DAYTIME HEATING. 4-6SM PATCHY BR WILL ONCE AGAIN BE POSSIBLE LATE
TONIGHT GIVEN HUMID AIRMASS AND LIGHT WINDS. DIURNAL CU WILL BEGIN
SCT MIDDAY TUESDAY WITH PERIODS OF BKN BY MID/LATE AFTERNOON AS A
FEW SHRAS OR TSRAS BEGIN TO DOT THE AREA. WINDS WILL REMAIN LIGHT
OUTSIDE OF STORMS AND GRADUALLY BACK TO SE BY LATE IN THE FORECAST.
FOR DTW...ISOLATED SHRA/TSRA WILL REMAIN POSSIBLE UNTIL ABOUT 01Z
WITH SCT DECK AOB 5KFT. SIMILAR SETUP TUESDAY AFTERNOON WITH CU
AROUND 3500 FEET TRENDING FROM SCT TO BKN DURING THE AFTERNOON.
//DTW THRESHOLD PROBABILITIES...
* LOW FOR CEILING AOB 5KFT THIS EVENING.
* LOW FOR THUNDERSTORMS THROUGH 01Z.
&&
.PREV DISCUSSION...ISSUED 350 PM EDT MON AUG 17 2015
SHORT TERM...THROUGH TONIGHT
WELL-DEFINED UPPER WAVE PER WATER VAPOR IMAGERY WILL TRACK FROM THE
ILLINOIS/INDIANA BORDER UP INTO SOUTHERN LOWER MICHIGAN TONIGHT AS
WESTERLY WINDS ALOFT STRENGTHEN IN RESPONSE TO AN UPPER TROUGH
DIGGING INTO THE NORTHERN ROCKIES/PLAINS. THE FRONTAL BOUNDARY OVER
NORTHERN MICHIGAN IS NOT EXPECTED TO MAKE TOO MUCH SOUTHWARD
PROGRESS TONIGHT...ONLY DROPPING A LITTLE FURTHER INTO NORTHERN
LOWER MICHIGAN...WITH ITS SLOWING ALSO A RESULT OF THE DEEPENING
TROUGH.
MOISTURE ADVECTION INTO SOUTHEAST MICHIGAN STILL LOOKS BEST AFTER
21Z. MOISTURE PLUME CAN BE SEEN ON WATER VAPOR LIFTING IN AHEAD OF
THE UPPER WAVE ATTM. PW VALUES WERE ALREADY FAIRLY HIGH ON THE 12Z
DTX RAOB...AND ARE FORECAST BY NAM/GFS TO RISE TO AROUND 1.7 INCHES
BY 00Z. FORCING WILL BE THE STRONGEST AS THE UPPER WAVE NEARS THE
MICHIGAN BORDER THIS EVENING AND THEN TRACKS OVERHEAD OVERNIGHT.
UNTIL THEN...SHOWERS/STORMS HAVE BEEN FIRING OVER THE FAR SOUTHERN
PART OF THE STATE WHERE THETA-E ADVECTION HAS BEEN STRONGER. EXPECT
SCATTERED SHOWERS/TSTORMS TO CONTINUE DEVELOPING THROUGH THE
EVENING...INCREASING IN COVERAGE AS SYNOPTIC FORCING INCREASES AND
TEMPERATURES ALOFT COOL SLIGHTLY AND STEEPEN LAPSE RATES.
THUNDERSTORMS WILL HAVE POTENTIAL TO PRODUCE VERY HEAVY RAINFALL
GIVEN HIGH DEGREE OF MOISTURE...GOOD INSTABILITY (1500-1700 J/KG ML
CAPE) THIS EVENING...AND SLOW STORM MOVEMENT AT ONLY 15 MPH. A FEW
STORMS MAY BECOME A LITTLE STRONG...PRODUCING WIND GUSTS TO 40 MPH.
THIS HAS ALREADY BEEN EVIDENCED BY A STORM THAT FORMED OVER FAR
WESTERN LAKE ERIE EARLIER TODAY...WHEN A 50 DBZ CORE QUICKLY PULSED
UP TO AROUND 21000FT. PAST SEVERAL RUNS OF THE HRRR HAVE HINTED THAT
VERY SMALL INDIVIDUAL CELLS THAT HAVE BEEN DEVELOPING WILL CONGEAL
INTO A LARGER AREA OF LIGHT SHOWERS LATER THIS EVENING AS CLOUD
COVER OVERSPREADS THE AREA AND WE LOSE DAYTIME HEATING.
TEMPERATURES WILL REMAIN FAIRLY WARM TONIGHT AS DEWPOINTS STAY IN
THE 60S AND CLOUD COVER LIMITS RADIATIONAL COOLING. THIS SHOULD KEEP
MIN TEMPS IN THE MID 60S TO NEAR 70.
LONG TERM...
RELATIVELY MOIST AIRMASS /PWAT VALUES 1.5-1.75 IN/ WILL LINGER OVER
THE GREAT LAKES ON TUESDAY. DISORGANIZED PATTERN MAKES IT HARD TO
IDENTIFY A GOOD LIFTING MECHANISM SO CONFIDENCE IS NOT PARTICULARLY
HIGH ON COVERAGE AND LOCATION OF SHOWERS. WEAKENING SHORTWAVE
TRACKING THROUGH THE STATE IN SOUTHWESTERLY FLOW SHOULD PROVIDE SOME
LIFT. MIDLEVEL MOISTURE LOOKS TO BE A BIT HIGHER OVER MID-MICHIGAN
INCLUDING THE TRI-CITIES AREA SO KEPT LIKELY POPS THERE BUT
GENERALLY BACKED OFF A BIT ON POPS. MEAGER LAPSE RATES WILL LIMIT
INSTABILITY THOUGH A FEW STORMS ARE STILL POSSIBLE WITH
WEAKLY NEGATIVE LIFTED INDICES DURING THE AFTERNOON. TEMPS
ARE EXPECTED TO BE SEVERAL DEGREES COOLER THAN MONDAY WITH THE UPPER
RIDGE HAVING DEPARTED ALONG WITH RELATIVELY HIGH CLOUD FRACTION.
A MILD NIGHT TUESDAY NIGHT WITH A FEW LINGERING SHOWERS POSSIBLE
THOUGH LIKELY WITH LESS COVERAGE THAN DURING THE DAY OWING TO LACK
OF DIURNAL INSTABILITY AND SUBLTE SHORTWAVE UPPER RIDGING.
ON WEDNESDAY...SHORTWAVE ENERGY WILL CONTINUE TO WRAP INTO THE DEEP
TROUGH OVER THE CENTRAL PLAINS AS IT DRIFTS NORTHEASTWARD. AT THE
SURFACE...AN UNSEASONABLY STRONG SURFACE LOW WILL OCCLUDE SOMEWHERE
IN THE VICINITY OF DULUTH MN. STILL VARYING SOLUTIONS WITH RESPECT
TO STRENGTH AND LOCATION OF THIS LOW AND RESULTING TIMING OF COLD
FRONT PUSH ACROSS LOWER MICHIGAN. A SLIGHTLY SLOWER TREND WAS NOTED
IN SOME OF THE 12Z GUIDANCE...WHICH LED TO INCREASING POPS FOR
WEDNESDAY NIGHT. CURRENT THINKING IS THAT THE PEAK TIME FOR PRECIP
IS LATE WEDNESDAY/EARLY WEDNESDAY NIGHT ALONG AND AHEAD OF THE
FRONT. HAVE TO HONOR SEVERE WEATHER THREAT DUE TO THE OVERALL
STRENGTH OF THE SYSTEM. HOWEVER...SIGNIFICANT QUESTION MARKS
EXIST. DEEP-LAYER SHEAR LOOKS TO BE LIMITED IN THE WARM SECTOR...AND
INSTABILITY IS A QUESTION MARK OWING TO WEAK MIDLEVEL LAPSE RATES
AND GOOD CLOUD COVERAGE. A LATER TIMING OF THE FRONT ALSO CASTS
DOUBT UPON SEVERE WEATHER POTENTIAL...ESPECIALLY IF SLOWER TREND
CONTINUES. AS FOR TEMPS...STRONGER SOUTHERLY WINDS ON WEDNESDAY WILL
BUMP UP HIGH TEMPS A COUPLE DEGREES RELATIVE TO TUESDAY.
RAIN SHOWERS WILL COME TO AN END EARLY THURSDAY AS STRONG HIGH
PRESSURE BUILDS INTO THE GREAT LAKES. THIS HIGH WILL STICK AROUND
THROUGH SATURDAY...KEEPING CONDITIONS DRY ACROSS SOUTHEAST MICHIGAN
THROUGH THE FIRST HALF OF THE WEEKEND. THERE IS A BIT OF TIMING
DIFFERENCES FOR THE NEXT COLD FRONT ASSOCIATED WITH A LOW PRESSURE
SYSTEM TRACKING OVER CANADA. SOME MODELS HAVE THE FRONT /AND
THEREFORE RAIN AND THUNDERSTORMS/ PUSHING THROUGH ON SUNDAY WITH
OTHERS NOT HAVING THE FRONT ARRIVING UNTIL EARLY MONDAY MORNING.
WILL HAVE TO KEEP AN EYE ON THIS FEATURE OVER THE NEXT COUPLE DAYS
AS TIMING GETS MORE CERTAIN.
MARINE...
INCREASING MOISTURE FROM THE WEST WILL SUPPORT PERIODS OF SHOWERS
AND THUNDERSTORMS TONIGHT THROUGH WEDNESDAY NIGHT...WITH THE MOST
WIDESPREAD ACTIVITY LIKELY WEDNESDAY AND WEDNESDAY NIGHT. A
DISORGANIZED PRESSURE PATTERN WILL RESULT IN GENERALLY LIGHT WINDS
TONIGHT INTO TUESDAY. EASTERLY/SOUTHEASTERLY FLOW WILL INCREASE
MODESTLY ON WEDNESDAY AS A LOW PRESSURE SYSTEM STRENGTHENS NEAR
DULUTH MN. THIS SYSTEM WILL PUSH A STRONG COLD FRONT THROUGH THE
WATERS LATE WEDNESDAY/WEDNESDAY NIGHT WITH BREEZY SOUTHWESTERLY FLOW
DEVELOPING BEHIND THE FRONT ON THURSDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....DG
SHORT TERM...HLO
LONG TERM....DT/RK
MARINE.......DT
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
443 PM EDT MON AUG 17 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 443 PM EDT MON AUG 17 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A BROAD TROF EXTENDING S
INTO THE NRN ROCKIES NRN PLAINS. POTENT LOOKING SHORTWAVE OVER SW MT
WILL GENERATE AN UNUSUALLY STRONG SFC LOW FOR AUG THAT WILL MOVE
ACROSS THE UPPER MISSISSIPPI VALLEY/UPPER GREAT LAKES TUE NIGHT/WED.
SYSTEM ON WATER VAPOR IMAGERY LOOKS STRONGER THAN INDICATED BY
MODELS RIGHT NOW...SO IT WILL BE INTERESTING TO SEE HOW THIS SYSTEM
EVOLVES. TO THE E AND AT THE SFC...COLD FRONT HAS DRIFTED S OF UPPER
MI. WEAKER SHORTWAVES AND RIGHT ENTRANCE OF UPPER JET EXTENDING FROM
NRN MN TO NRN QUEBEC ARE AIDING SHRA/TSTMS FROM IA/SRN MN ENE TO ERN
UPPER MI AND LWR MI. PER LATEST SPC ANALYSIS NRN EDGE OF INSTABILITY
(MLCAPES EXCEEDING 100J/KG) ONLY EXTENDS AS FAR N AS NEAR KMNM AND
THEN E ACROSS NRN LAKE MI. THUS...NO THUNDER HAS BEEN NOTED IN UPPER
MI THIS AFTN.
RIGHT ENTRANCE OF A LESS WELL-DEFINED WITH TIME UPPER JET WILL POSE
SOME RISK FOR GENERATING -SHRA AT TIMES TONIGHT TO THE N OF THE COLD
FRONT WHICH WILL BECOME NEARLY STATIONARY. THERE MAY BE A SUBTLE
SHORTWAVE UPSTREAM AS WELL WHICH COULD AID -SHRA DEVELOPMENT FARTHER
N PER ECWMF...BUT STAYED CLOSE TO THE MULTI-MODEL CONSENSUS IN
CARRYING SCHC POPS FOR AT LEAST SOME PORTION OF THE NIGHT OVER
ROUGHLY THE SE HALF OF THE FCST AREA. CHC POPS WERE CONFINED TO THE
FAR SCNTRL...AND ALSO SE CLOSE TO LAKE MI THIS EVENING. NOT
EXPECTING ANY TSTMS. MAY SEE SOME PATCHY FOG OVERNIGHT.
ON TUE...SFC LOW PRES ORGANIZES OVER THE PLAINS AND REACHES NW IA
LATE IN THE DAY IN RESPONSE TO THE STRONG SHORTWAVE MOVING OUT OVER
THE PLAINS. STRENGTHENING DEEP LAYER FORCING AND STRONG MOISTURE
TRANSPORT AHEAD OF FEATURE WILL SPREAD OVER MN AND THEN TOWARD NW
WI/WRN LAKE SUPERIOR/WRN UPPER MI LATE IN THE AFTN...RESULTING IN AN
INCREASING AREA OF MDT/HVY RAIN AND EMBEDDED THUNDER ORGANIZING TO
THE W AND SW. LOOKS LIKE MUCH OF THIS PCPN WILL HOLD OFF UNTIL TUE
NIGHT. AS FRONT TO THE S BEGINS TO MOVE BACK TO THE N AS A WARM
FRONT...PROBABLY CAN`T RULE OUT A FEW -SHRA DEVELOPING N OF THE
FRONT AS WAA BEGINS...BUT AT LEAST RIGHT NOW...POTENTIAL APPEARS
QUITE LOW. ONLY SCHC WILL BE UTILIZED EXCEPT FOR THE W IN THE AFTN
WHERE POPS WILL INCREASE THRU THE CHC CATEGORY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 332 PM EDT MON AUG 17 2015
A LOW INTENSIFYING ALONG THE MINNESOTA AND IOWA BORDER AT THE START
OF THE PERIOD WILL BRING UNSETTLED WEATHER FOR THE UPPER GREAT
LAKES REGION THROUGH THE FIRST HALF OF THE LONG TERM FORECAST. THIS
LOW WILL BE AROUND 998MB AND WILL BE LIFTING TO THE NORTH TUESDAY
NIGHT INTO WEDNESDAY (WHILE STRENGTHENING TO 993MB) IN RESPONSE TO
A SHORTWAVE ROUNDING THE BASE OF THE UPPER TROUGH IN THE NORTHERN
PLAINS. THERE ARE SOME DIFFERENCES IN THE MODELS ON HOW FAST THIS
LOW (ANOMALOUS FOR MID-LATE AUGUST) WILL MOVE NORTH THROUGH THE
DULUTH AREA AND ACROSS WESTERN LAKE SUPERIOR ON WEDNESDAY...BUT WITH
THE RECENT TRENDS HEADING TOWARDS A SLOWER DEPARTURE FROM LAKE
SUPERIOR...WILL FOLLOW THAT IDEA IN THE FORECAST.
EXPECT A FEW WAVES OF PRECIPITATION TO MOVE THROUGH THE U.P. WITH
THIS LOW...BUT UNFORTUNATELY THE TRACK WILL NOT PROMOTE A
MUCH NEEDED WIDESPREAD AND SOAKING RAIN FOR MOST OF THE AREA. THE
FIRST WAVE WILL ARRIVE LATE TOMORROW AFTERNOON AND INTO TOMORROW
NIGHT AS BROAD MID LEVEL WARM AIR ADVECTION SWEEPS NORTH ACROSS THE
AREA. THE BEST ASCENT WILL BE TO THE WEST-NORTHWEST OF THE AREA AND
TOWARDS THE MINNESOTA ARROWHEAD...BUT THE WESTERN U.P. COULD BE
BRUSHED BY SOME OF THE STRONGER AREAS OF RAIN. OTHERWISE...EXPECT
RAINFALL AMOUNTS TO SLOWLY DIMINISH FROM AROUND AN INCH OVER THE FAR
WEST TO A HALF AN INCH OR LESS TO THE EAST OF NEWBERRY.
THE NEXT WAVE WILL PUSH NORTH-NORTHEAST THROUGH THE CWA ON
WEDNESDAY MORNING AND PRODUCE AN AREA OF SCATTERED/NUMEROUS SHOWERS
AND MAYBE A FEW THUNDERSTORMS AS IT MOVES THROUGH THE AREA. WILL
SHOW A PERIOD OF THUNDER CHANCES ALONG THAT FRONT AS IT MOVES
THROUGH...TIED TO THE LOWER SHOWALTER VALUES AND MUCAPE VALUES
RISING BETWEEN 500-750 J/KG RIGHT ALONG THE FRONT. EFFECTIVE SHEAR
VALUES LOOK TO BE FAIRLY LOW...SO THAT SHOULD ELIMINATE MUCH OF THE
SEVERE THREAT...EXCEPT FOR AREAS RIGHT ALONG THE COLD FRONT WHICH
WILL TRY TO PUSH EFFECTIVE SHEAR VALUES UP TOWARDS 30KTS. AS THIS
FRONT MOVES NORTH THROUGH THE DAY AND THE DRY SLOT MOVES OVER THE
AREA ALOFT...HAVE TRENDED POPS DOWN OVER THE CENTRAL AND EAST
THROUGH THE DAY...WITH ONLY SLIGHT CHANCES IN THE AFTERNOON
(ALTHOUGH THAT MAY BE TOO HIGH). WRAP AROUND RAIN WILL THEN ARRIVE
OVER THE WEST LATE WEDNESDAY AFTERNOON AND CONTINUE INTO WEDNESDAY
NIGHT. EXPECT THE SCATTERED/NUMEROUS SHOWERS TO STAY MORE OVER THE
WESTERN U.P. BUT DID SPREAD CHANCES EAST OVERNIGHT INTO THURSDAY FOR
MUCH OF THE REST OF THE U.P. WINDS WILL ALSO BE ON THE INCREASE
LATE WEDNESDAY NIGHT INTO THURSDAY MORNING BEHIND THE LOW DUE TO
THE COMBINED PRESSURE RISE AND STEEPENING LOW LEVEL LAPSE RATES
TOWARDS 8-9 C/KM BETWEEN THE SURFACE AND 900MB. THAT WILL LIKELY
PRODUCE GUSTS TO 30KTS OVER WESTERN/CENTRAL LAKE SUPERIOR AND
20-30KTS OVER MOST LAND AREAS.
CONDITIONS WILL IMPROVE THURSDAY NIGHT AS A HIGH PRESSURE RIDGE
BUILDS INTO THE AREA. THIS WILL BRING DECREASING CLOUDS AND WINDS
THROUGH THE NIGHT AND SHOULD LEAD TO A NICE DAY ACROSS THE AREA ON
FRIDAY. THE SUNSHINE WILL BRING HIGHS BACK UP TO NORMAL OR SLIGHTLY
ABOVE NORMAL VALUES ON FRIDAY AND EXPECT TEMPERATURES A TOUCH
WARMER ON SATURDAY (AROUND 80) WITH THE SOUTHERLY FLOW.
ANOTHER STRONG UPPER TROUGH WILL MOVE INTO THE NORTHERN PLAINS ON
SATURDAY AND MOVE THROUGH THE AREA SUNDAY INTO SUNDAY NIGHT. WILL
CONTINUE TO SHOW HIGH CHANCE AND LOW END LIKELY POPS AS THAT MOVES
THROUGH THE AREA BEFORE SLOWLY DEPARTING ON MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 137 PM EDT MON AUG 17 2015
DRIER AIR WILL MAKE SOME INROADS INTO THE AREA THIS AFTN BEHIND A
COLD FRONT THAT HAS SLIPPED SE OF UPPER MI. AS A RESULT...EXPECT
KIWD TO BREAK OUT FROM MVFR TO VFR IN THE NEXT COUPLE OF HRS. KCMX
WILL REMAIN VFR. DRYING WILL BE SLOWER AT KSAW...AND THIS SHOULD
LEAD TO MVFR CIGS PREVAILING FOR MUCH OF THE AFTN INTO THE EARLY
EVENING. AFTER A BREAK TO VFR THIS EVENING AT KSAW...MVFR CIGS MAY
RETURN LATE TONIGHT/TUE MORNING UNDER LIGHT UPSLOPE FLOW OFF LAKE
SUPERIOR. KIWD/KCMX SHOULD REMAIN VFR...THOUGH THERE IS A LOW
POTENTIAL FOR FOG DEVELOPMENT LATE TONIGHT.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 443 PM EDT MON AUG 17 2015
HIGH PRES STRETCHING FROM SOUTHERN MANITOBA THROUGH JAMES BAY WILL
EXTEND A RIDGE INTO THE UPPER LAKES THRU TUE MORNING...RESULTING IN
LIGHT WINDS UNDER 15KT ACROSS LAKE SUPERIOR THRU TUE MORNING.
THEN...AS LOW PRES ORGANIZES AND STRENGTHENS OVER THE PLAINS
TUE...NE WINDS WILL BEGIN TO RAMP UP...ESPECIALLY OVER WRN LAKE
SUPERIOR WHERE GUSTS SHOULD REACH 25-30KT LATE AFTN/EARLY EVENING.
THIS LOW WILL BECOME UNSEASONABLY DEEP FOR AUG AS IT LIFTS ACROSS
FAR WRN LAKE SUPERIOR WED AFTN. 20-30KT WINDS ARE EXPECTED OVER MUCH
OF THE LAKE TUE NIGHT INTO WED. MAY SEE GALE FORCE GUSTS OVER FAR
WRN LAKE SUPERIOR IN THE NE WINDS AHEAD OF THE LOW TUE NIGHT AND
THEN IN THE WESTERLY WINDS ACROSS MAINLY CENTRAL LAKE SUPERIOR ON
THU AS THE LOW LIFTS N OF THE AREA. WINDS WILL DIMINISH TO UNDER
20KT FRI...AND THEN BEGIN TO INCREASE AGAIN ON SAT AHEAD OF THE NEXT
COLD FRONT MOVING OUT ACROSS THE PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
350 PM EDT MON AUG 17 2015
.SHORT TERM...THROUGH TONIGHT
WELL-DEFINED UPPER WAVE PER WATER VAPOR IMAGERY WILL TRACK FROM THE
ILLINOIS/INDIANA BORDER UP INTO SOUTHERN LOWER MICHIGAN TONIGHT AS
WESTERLY WINDS ALOFT STRENGTHEN IN RESPONSE TO AN UPPER TROUGH
DIGGING INTO THE NORTHERN ROCKIES/PLAINS. THE FRONTAL BOUNDARY OVER
NORTHERN MICHIGAN IS NOT EXPECTED TO MAKE TOO MUCH SOUTHWARD
PROGRESS TONIGHT...ONLY DROPPING A LITTLE FURTHER INTO NORTHERN
LOWER MICHIGAN...WITH ITS SLOWING ALSO A RESULT OF THE DEEPENING
TROUGH.
MOISTURE ADVECTION INTO SOUTHEAST MICHIGAN STILL LOOKS BEST AFTER
21Z. MOISTURE PLUME CAN BE SEEN ON WATER VAPOR LIFTING IN AHEAD OF
THE UPPER WAVE ATTM. PW VALUES WERE ALREADY FAIRLY HIGH ON THE 12Z
DTX RAOB...AND ARE FORECAST BY NAM/GFS TO RISE TO AROUND 1.7 INCHES
BY 00Z. FORCING WILL BE THE STRONGEST AS THE UPPER WAVE NEARS THE
MICHIGAN BORDER THIS EVENING AND THEN TRACKS OVERHEAD OVERNIGHT.
UNTIL THEN...SHOWERS/STORMS HAVE BEEN FIRING OVER THE FAR SOUTHERN
PART OF THE STATE WHERE THETA-E ADVECTION HAS BEEN STRONGER. EXPECT
SCATTERED SHOWERS/TSTORMS TO CONTINUE DEVELOPING THROUGH THE
EVENING...INCREASING IN COVERAGE AS SYNOPTIC FORCING INCREASES AND
TEMPERATURES ALOFT COOL SLIGHTLY AND STEEPEN LAPSE RATES.
THUNDERSTORMS WILL HAVE POTENTIAL TO PRODUCE VERY HEAVY RAINFALL
GIVEN HIGH DEGREE OF MOISTURE...GOOD INSTABILITY (1500-1700 J/KG ML
CAPE) THIS EVENING...AND SLOW STORM MOVEMENT AT ONLY 15 MPH. A FEW
STORMS MAY BECOME A LITTLE STRONG...PRODUCING WIND GUSTS TO 40 MPH.
THIS HAS ALREADY BEEN EVIDENCED BY A STORM THAT FORMED OVER FAR
WESTERN LAKE ERIE EARLIER TODAY...WHEN A 50 DBZ CORE QUICKLY PULSED
UP TO AROUND 21000FT. PAST SEVERAL RUNS OF THE HRRR HAVE HINTED THAT
VERY SMALL INDIVIDUAL CELLS THAT HAVE BEEN DEVELOPING WILL CONGEAL
INTO A LARGER AREA OF LIGHT SHOWERS LATER THIS EVENING AS CLOUD
COVER OVERSPREADS THE AREA AND WE LOSE DAYTIME HEATING.
TEMPERATURES WILL REMAIN FAIRLY WARM TONIGHT AS DEWPOINTS STAY IN
THE 60S AND CLOUD COVER LIMITS RADIATIONAL COOLING. THIS SHOULD KEEP
MIN TEMPS IN THE MID 60S TO NEAR 70.
&&
.LONG TERM...
RELATIVELY MOIST AIRMASS /PWAT VALUES 1.5-1.75 IN/ WILL LINGER OVER
THE GREAT LAKES ON TUESDAY. DISORGANIZED PATTERN MAKES IT HARD TO
IDENTIFY A GOOD LIFTING MECHANISM SO CONFIDENCE IS NOT PARTICULARLY
HIGH ON COVERAGE AND LOCATION OF SHOWERS. WEAKENING SHORTWAVE
TRACKING THROUGH THE STATE IN SOUTHWESTERLY FLOW SHOULD PROVIDE SOME
LIFT. MIDLEVEL MOISTURE LOOKS TO BE A BIT HIGHER OVER MID-MICHIGAN
INCLUDING THE TRI-CITIES AREA SO KEPT LIKELY POPS THERE BUT
GENERALLY BACKED OFF A BIT ON POPS. MEAGER LAPSE RATES WILL LIMIT
INSTABILITY THOUGH A FEW STORMS ARE STILL POSSIBLE WITH
WEAKLY NEGATIVE LIFTED INDICES DURING THE AFTERNOON. TEMPS
ARE EXPECTED TO BE SEVERAL DEGREES COOLER THAN MONDAY WITH THE UPPER
RIDGE HAVING DEPARTED ALONG WITH RELATIVELY HIGH CLOUD FRACTION.
A MILD NIGHT TUESDAY NIGHT WITH A FEW LINGERING SHOWERS POSSIBLE
THOUGH LIKELY WITH LESS COVERAGE THAN DURING THE DAY OWING TO LACK
OF DIURNAL INSTABILITY AND SUBLTE SHORTWAVE UPPER RIDGING.
ON WEDNESDAY...SHORTWAVE ENERGY WILL CONTINUE TO WRAP INTO THE DEEP
TROUGH OVER THE CENTRAL PLAINS AS IT DRIFTS NORTHEASTWARD. AT THE
SURFACE...AN UNSEASONABLY STRONG SURFACE LOW WILL OCCLUDE SOMEWHERE
IN THE VICINITY OF DULUTH MN. STILL VARYING SOLUTIONS WITH RESPECT
TO STRENGTH AND LOCATION OF THIS LOW AND RESULTING TIMING OF COLD
FRONT PUSH ACROSS LOWER MICHIGAN. A SLIGHTLY SLOWER TREND WAS NOTED
IN SOME OF THE 12Z GUIDANCE...WHICH LED TO INCREASING POPS FOR
WEDNESDAY NIGHT. CURRENT THINKING IS THAT THE PEAK TIME FOR PRECIP
IS LATE WEDNESDAY/EARLY WEDNESDAY NIGHT ALONG AND AHEAD OF THE
FRONT. HAVE TO HONOR SEVERE WEATHER THREAT DUE TO THE OVERALL
STRENGTH OF THE SYSTEM. HOWEVER...SIGNIFICANT QUESTION MARKS
EXIST. DEEP-LAYER SHEAR LOOKS TO BE LIMITED IN THE WARM SECTOR...AND
INSTABILITY IS A QUESTION MARK OWING TO WEAK MIDLEVEL LAPSE RATES
AND GOOD CLOUD COVERAGE. A LATER TIMING OF THE FRONT ALSO CASTS
DOUBT UPON SEVERE WEATHER POTENTIAL...ESPECIALLY IF SLOWER TREND
CONTINUES. AS FOR TEMPS...STRONGER SOUTHERLY WINDS ON WEDNESDAY WILL
BUMP UP HIGH TEMPS A COUPLE DEGREES RELATIVE TO TUESDAY.
RAIN SHOWERS WILL COME TO AN END EARLY THURSDAY AS STRONG HIGH
PRESSURE BUILDS INTO THE GREAT LAKES. THIS HIGH WILL STICK AROUND
THROUGH SATURDAY...KEEPING CONDITIONS DRY ACROSS SOUTHEAST MICHIGAN
THROUGH THE FIRST HALF OF THE WEEKEND. THERE IS A BIT OF TIMING
DIFFERENCES FOR THE NEXT COLD FRONT ASSOCIATED WITH A LOW PRESSURE
SYSTEM TRACKING OVER CANADA. SOME MODELS HAVE THE FRONT /AND
THEREFORE RAIN AND THUNDERSTORMS/ PUSHING THROUGH ON SUNDAY WITH
OTHERS NOT HAVING THE FRONT ARRIVING UNTIL EARLY MONDAY MORNING.
WILL HAVE TO KEEP AN EYE ON THIS FEATURE OVER THE NEXT COUPLE DAYS
AS TIMING GETS MORE CERTAIN.
&&
.MARINE...
INCREASING MOISTURE FROM THE WEST WILL SUPPORT PERIODS OF SHOWERS
AND THUNDERSTORMS TONIGHT THROUGH WEDNESDAY NIGHT...WITH THE MOST
WIDESPREAD ACTIVITY LIKELY WEDNESDAY AND WEDNESDAY NIGHT. A
DISORGANIZED PRESSURE PATTERN WILL RESULT IN GENERALLY LIGHT WINDS
TONIGHT INTO TUESDAY. EASTERLY/SOUTHEASTERLY FLOW WILL INCREASE
MODESTLY ON WEDNESDAY AS A LOW PRESSURE SYSTEM STRENGTHENS NEAR
DULUTH MN. THIS SYSTEM WILL PUSH A STRONG COLD FRONT THROUGH THE
WATERS LATE WEDNESDAY/WEDNESDAY NIGHT WITH BREEZY SOUTHWESTERLY FLOW
DEVELOPING BEHIND THE FRONT ON THURSDAY.
&&
.AVIATION...ISSUED 208 PM EDT MON AUG 17 2015
CU WILL CONTINUE TO FILL IN...WITH 3500-4500FT CEILINGS DEVELOPING
BETWEEN 19-21Z. SHOWERS AND THUNDERSTORMS WILL ALSO CONTINUE TO
DEVELOP...BECOMING MORE NUMEROUS THROUGH THE AFTERNOON AND EVENING
AS AN UPPER LEVEL DISTURBANCE TRACKS FROM INDIANA TO LOWER MICHIGAN.
MID AND HIGH CLOUDS WILL REMAIN AROUND THROUGH MUCH OF THE
NIGHT...THINNING OUT TOWARDS SUNRISE. THE CLEARING AND LIGHT WINDS
MAY ALLOW SOME LIGHT MVFR FOG TO FILL IN AS LOW-LEVEL
MOISTURE REMAINS IN PLACE.
FOR DTW...3500-4500 CEILINGS WILL CONTINUE TO FILL IN AND BECOME BKN
AT 19-20Z. BEST POTENTIAL FOR SHOWERS AND THUNDERSTORMS WILL BE
BETWEEN 20Z AND 00Z.
//DTW THRESHOLD PROBABILITIES...
* MEDIUM FOR CEILING 5000 FT OR LESS DURING AFTERNOON AND EVENING.
* LOW FOR THUNDERSTORMS DURING LATE AFTERNOON AND EARLY EVENING.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...HLO
LONG TERM....DT/RK
MARINE.......DT
AVIATION.....HLO
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
333 PM EDT MON AUG 17 2015
.UPDATE...
ISSUED AT 1110 AM EDT MON AUG 17 2015
500 MB SHORTWAVE TROUGH MOVING FROM NE IOWA INTO WISCONSIN, IS
PRODUCING SHOWERS ALONG A COLD FRONT THAT STRETCHES FROM AROUND
CYXZ (WAWA) TO NEAR KLSE. THE NORTHERN END HAS DIMINISHED OVER THE
LAST FEW HOURS AS THE SYSTEM HAS BIFURCATED SOMEWHAT, BUT WITH THE
500 MB SHORTWAVE, A NEW AREA OF RAIN IS MOVING OUT OF CENTRAL
WISCONSIN AND INTO W AND C UPPER. THIS IS EXPECTED TO CONTINUE
INTO THE AFTERNOON, SO HAVE BUMPED UP THE POPS ALONG THE FRONT FOR
THE NEXT FEW HOURS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 530 AM EDT MON AUG 17 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A BROAD TROUGH FROM HUDSON BAY
INTO THE NRN PLAINS AND A RIDGE OVER THE ERN CONUS RESULTING IN WSW
MID/UPPER LEVEL FLOW THROUGH THE NRN GREAT LAKES. AT THE SFC...A
COLD FRONT EXTENDED FROM THE SRN END OF JAMES BAY THROUGH ERN
UPPER MI INTO NE WI. A WEAK SHRTWV COMBINED WITH MID LEVEL FGEN
AND UPPER LEVEL DIV WITH THE RIGHT ENTRANCE OF THE 250-300 MB JET
OVER NW ONTARIO SUPPORTED SCT/NMRS SHRA ACROSS CNTRL AND ERN UPPER
MI. THE AXIS OF GREATER INSTABILITY/MUCAPE TO AROUND 1K J/KG
LINGERED OVER THE SE CWA AND IN COMBINATION WITH 0-6KM SHEAR TO
NEAR 40 KNOTS SUPPORTED CLUSTERS OF STRONG/SVR STORMS OVER THE SRN
CWA OVERNIGHT NEAR THE COLD FRONT.
TODAY...EXPECT THAT THE 850-700 MB FRONTAL BOUNDARY WILL LINGER OVER
THE AREA EVEN AS THE SFC FRONT CONTINUES TO SLIDE TO THE SE. AS
ANOTHER WEAK SHORTWAVE MOVES TOWARD THE AREA...SCT SHOWERS ARE
EXPECTED TO CONTINUE OVER THE SE HALF OF UPPER MI. THERE MAY BE JUST
ENOUGH LINGERING MUCAPE FOR SOME TSRA OVER THE FAR SE.
OTHERWISE...MUCH COOLER CONDITIONS WILL PREVAIL WITH MAX TEMPS IN
THE LOWER 70S AND DEWPOINTS DROPPING INTO THE MID AND UPPER 50S NW
TO THE LOWER 60S SE.
TONIGHT...SHOWERS CHANCES...MAINLY OVER THE SOUTH AND EAST WILL
CONTINUE TO DIMINISH WITH THE MAIN FRONTAL BOUNDARY LINGERING
FARTHER TO THE SOUTH.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 332 PM EDT MON AUG 17 2015
A LOW INTENSIFYING ALONG THE MINNESOTA AND IOWA BORDER AT THE START
OF THE PERIOD WILL BRING UNSETTLED WEATHER FOR THE UPPER GREAT
LAKES REGION THROUGH THE FIRST HALF OF THE LONG TERM FORECAST. THIS
LOW WILL BE AROUND 998MB AND WILL BE LIFTING TO THE NORTH TUESDAY
NIGHT INTO WEDNESDAY (WHILE STRENGTHENING TO 993MB) IN RESPONSE TO
A SHORTWAVE ROUNDING THE BASE OF THE UPPER TROUGH IN THE NORTHERN
PLAINS. THERE ARE SOME DIFFERENCES IN THE MODELS ON HOW FAST THIS
LOW (ANOMALOUS FOR MID-LATE AUGUST) WILL MOVE NORTH THROUGH THE
DULUTH AREA AND ACROSS WESTERN LAKE SUPERIOR ON WEDNESDAY...BUT WITH
THE RECENT TRENDS HEADING TOWARDS A SLOWER DEPARTURE FROM LAKE
SUPERIOR...WILL FOLLOW THAT IDEA IN THE FORECAST.
EXPECT A FEW WAVES OF PRECIPITATION TO MOVE THROUGH THE U.P. WITH
THIS LOW...BUT UNFORTUNATELY THE TRACK WILL NOT PROMOTE A
MUCH NEEDED WIDESPREAD AND SOAKING RAIN FOR MOST OF THE AREA. THE
FIRST WAVE WILL ARRIVE LATE TOMORROW AFTERNOON AND INTO TOMORROW
NIGHT AS BROAD MID LEVEL WARM AIR ADVECTION SWEEPS NORTH ACROSS THE
AREA. THE BEST ASCENT WILL BE TO THE WEST-NORTHWEST OF THE AREA AND
TOWARDS THE MINNESOTA ARROWHEAD...BUT THE WESTERN U.P. COULD BE
BRUSHED BY SOME OF THE STRONGER AREAS OF RAIN. OTHERWISE...EXPECT
RAINFALL AMOUNTS TO SLOWLY DIMINISH FROM AROUND AN INCH OVER THE FAR
WEST TO A HALF AN INCH OR LESS TO THE EAST OF NEWBERRY.
THE NEXT WAVE WILL PUSH NORTH-NORTHEAST THROUGH THE CWA ON
WEDNESDAY MORNING AND PRODUCE AN AREA OF SCATTERED/NUMEROUS SHOWERS
AND MAYBE A FEW THUNDERSTORMS AS IT MOVES THROUGH THE AREA. WILL
SHOW A PERIOD OF THUNDER CHANCES ALONG THAT FRONT AS IT MOVES
THROUGH...TIED TO THE LOWER SHOWALTER VALUES AND MUCAPE VALUES
RISING BETWEEN 500-750 J/KG RIGHT ALONG THE FRONT. EFFECTIVE SHEAR
VALUES LOOK TO BE FAIRLY LOW...SO THAT SHOULD ELIMINATE MUCH OF THE
SEVERE THREAT...EXCEPT FOR AREAS RIGHT ALONG THE COLD FRONT WHICH
WILL TRY TO PUSH EFFECTIVE SHEAR VALUES UP TOWARDS 30KTS. AS THIS
FRONT MOVES NORTH THROUGH THE DAY AND THE DRY SLOT MOVES OVER THE
AREA ALOFT...HAVE TRENDED POPS DOWN OVER THE CENTRAL AND EAST
THROUGH THE DAY...WITH ONLY SLIGHT CHANCES IN THE AFTERNOON
(ALTHOUGH THAT MAY BE TOO HIGH). WRAP AROUND RAIN WILL THEN ARRIVE
OVER THE WEST LATE WEDNESDAY AFTERNOON AND CONTINUE INTO WEDNESDAY
NIGHT. EXPECT THE SCATTERED/NUMEROUS SHOWERS TO STAY MORE OVER THE
WESTERN U.P. BUT DID SPREAD CHANCES EAST OVERNIGHT INTO THURSDAY FOR
MUCH OF THE REST OF THE U.P. WINDS WILL ALSO BE ON THE INCREASE
LATE WEDNESDAY NIGHT INTO THURSDAY MORNING BEHIND THE LOW DUE TO
THE COMBINED PRESSURE RISE AND STEEPENING LOW LEVEL LAPSE RATES
TOWARDS 8-9 C/KM BETWEEN THE SURFACE AND 900MB. THAT WILL LIKELY
PRODUCE GUSTS TO 30KTS OVER WESTERN/CENTRAL LAKE SUPERIOR AND
20-30KTS OVER MOST LAND AREAS.
CONDITIONS WILL IMPROVE THURSDAY NIGHT AS A HIGH PRESSURE RIDGE
BUILDS INTO THE AREA. THIS WILL BRING DECREASING CLOUDS AND WINDS
THROUGH THE NIGHT AND SHOULD LEAD TO A NICE DAY ACROSS THE AREA ON
FRIDAY. THE SUNSHINE WILL BRING HIGHS BACK UP TO NORMAL OR SLIGHTLY
ABOVE NORMAL VALUES ON FRIDAY AND EXPECT TEMPERATURES A TOUCH
WARMER ON SATURDAY (AROUND 80) WITH THE SOUTHERLY FLOW.
ANOTHER STRONG UPPER TROUGH WILL MOVE INTO THE NORTHERN PLAINS ON
SATURDAY AND MOVE THROUGH THE AREA SUNDAY INTO SUNDAY NIGHT. WILL
CONTINUE TO SHOW HIGH CHANCE AND LOW END LIKELY POPS AS THAT MOVES
THROUGH THE AREA BEFORE SLOWLY DEPARTING ON MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 137 PM EDT MON AUG 17 2015
DRIER AIR WILL MAKE SOME INROADS INTO THE AREA THIS AFTN BEHIND A
COLD FRONT THAT HAS SLIPPED SE OF UPPER MI. AS A RESULT...EXPECT
KIWD TO BREAK OUT FROM MVFR TO VFR IN THE NEXT COUPLE OF HRS. KCMX
WILL REMAIN VFR. DRYING WILL BE SLOWER AT KSAW...AND THIS SHOULD
LEAD TO MVFR CIGS PREVAILING FOR MUCH OF THE AFTN INTO THE EARLY
EVENING. AFTER A BREAK TO VFR THIS EVENING AT KSAW...MVFR CIGS MAY
RETURN LATE TONIGHT/TUE MORNING UNDER LIGHT UPSLOPE FLOW OFF LAKE
SUPERIOR. KIWD/KCMX SHOULD REMAIN VFR...THOUGH THERE IS A LOW
POTENTIAL FOR FOG DEVELOPMENT LATE TONIGHT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 534 AM EDT MON AUG 17 2015
WINDS WILL REMAIN AT OR BELOW 20 KNOTS THROUGH TONIGHT...THEN
NE WINDS WILL INCREASE TO UP TO 30 KNOTS TUE INTO TUE NIGHT AS A LOW
PRES SYSTEM MOVES INTO THE UPPER MS VALLEY. WINDS MAY TEMPORARILY
DIMINISH WED AS A LOW PRES SYSTEM MOVES TOWARD LAKE SUPERIOR.
HOWEVER...AS THE STRONG LOW DEPARS LATE WED NIGHT INTO THU SOME WRLY
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JSL
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
137 PM EDT MON AUG 17 2015
.UPDATE...
ISSUED AT 1110 AM EDT MON AUG 17 2015
500 MB SHORTWAVE TROUGH MOVING FROM NE IOWA INTO WISCONSIN, IS
PRODUCING SHOWERS ALONG A COLD FRONT THAT STRETCHES FROM AROUND
CYXZ (WAWA) TO NEAR KLSE. THE NORTHERN END HAS DIMINISHED OVER THE
LAST FEW HOURS AS THE SYSTEM HAS BIFURCATED SOMEWHAT, BUT WITH THE
500 MB SHORTWAVE, A NEW AREA OF RAIN IS MOVING OUT OF CENTRAL
WISCONSIN AND INTO W AND C UPPER. THIS IS EXPECTED TO CONTINUE
INTO THE AFTERNOON, SO HAVE BUMPED UP THE POPS ALONG THE FRONT FOR
THE NEXT FEW HOURS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 530 AM EDT MON AUG 17 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A BROAD TROUGH FROM HUDSON BAY
INTO THE NRN PLAINS AND A RIDGE OVER THE ERN CONUS RESULTING IN WSW
MID/UPPER LEVEL FLOW THROUGH THE NRN GREAT LAKES. AT THE SFC...A
COLD FRONT EXTENDED FROM THE SRN END OF JAMES BAY THROUGH ERN
UPPER MI INTO NE WI. A WEAK SHRTWV COMBINED WITH MID LEVEL FGEN
AND UPPER LEVEL DIV WITH THE RIGHT ENTRANCE OF THE 250-300 MB JET
OVER NW ONTARIO SUPPORTED SCT/NMRS SHRA ACROSS CNTRL AND ERN UPPER
MI. THE AXIS OF GREATER INSTABILITY/MUCAPE TO AROUND 1K J/KG
LINGERED OVER THE SE CWA AND IN COMBINATION WITH 0-6KM SHEAR TO
NEAR 40 KNOTS SUPPORTED CLUSTERS OF STRONG/SVR STORMS OVER THE SRN
CWA OVERNIGHT NEAR THE COLD FRONT.
TODAY...EXPECT THAT THE 850-700 MB FRONTAL BOUNDARY WILL LINGER OVER
THE AREA EVEN AS THE SFC FRONT CONTINUES TO SLIDE TO THE SE. AS
ANOTHER WEAK SHORTWAVE MOVES TOWARD THE AREA...SCT SHOWERS ARE
EXPECTED TO CONTINUE OVER THE SE HALF OF UPPER MI. THERE MAY BE JUST
ENOUGH LINGERING MUCAPE FOR SOME TSRA OVER THE FAR SE.
OTHERWISE...MUCH COOLER CONDITIONS WILL PREVAIL WITH MAX TEMPS IN
THE LOWER 70S AND DEWPOINTS DROPPING INTO THE MID AND UPPER 50S NW
TO THE LOWER 60S SE.
TONIGHT...SHOWERS CHANCES...MAINLY OVER THE SOUTH AND EAST WILL
CONTINUE TO DIMINISH WITH THE MAIN FRONTAL BOUNDARY LINGERING
FARTHER TO THE SOUTH.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 523 AM EDT MON AUG 17 2015
SEASONABLY COOL WEATHER WILL PREVAIL FOR THE MIDDLE OF THE WEEK
AMIDST RAIN. TEMPS WILL INCH BACK TO ABOVE AVERAGE BY SATURDAY
BEFORE A COLD FRONT BRINGS A CHANCE FOR RAIN AND ANOTHER COOL-DOWN
ON SUNDAY.
TUESDAY...DEEP MID-LEVEL TROUGHING WILL BE ONGOING ACROSS THE
NORTHERN AND CENTRAL PLAINS BY TUESDAY MORNING...WITH A LEE CYCLONE
FORMING OVER THE CENTRAL HIGH PLAINS. MEANWHILE...THE COLD FRONT
THAT CROSSED THE AREA EARLIER TODAY WILL HAVE WASHED OUT ACROSS
NORTHERN WI...WITH THE H7 TO H8 FRONT LINGERING AS FAR NORTH AS THE
SOUTH-CENTRAL CWA. WIDESPREAD WAA AHEAD OF THE DEVELOPING LOW LOOKS
TO HOLD OFF UNTIL TUESDAY NIGHT...THOUGH MID-LEVEL FGEN BECOMES
APPARENT BY THE AFTERNOON. WITH MODELS BEGINNING TO BACK OFF ON THE
SOUTHWARD PUSH OF DEEP DRY AIR BEHIND THE FRONT TODAY...THINK THAT
AT LEAST SOME LIGHT RAIN WILL BE POSSIBLE BY TUESDAY AFTERNOON.
GIVEN THAT WAA/ISENTROPIC LIFT IS STILL MINIMAL...CONTINUED WITH
JUST SLIGHT CHANCES IN THE FORECAST.
TUESDAY NIGHT AND WEDNESDAY...LOW-LEVEL MOISTURE TRANSPORT AND
ISENTROPIC LIFT QUICKLY INCREASE TUESDAY EVENING AS THE SFC LOW
STRENGTHENS AND NEARS. THE MID-LEVEL SHORTWAVE BEGINS TO TAKE ON
MORE OF A NEGATIVE TILT BY THIS TIME...SENDING MUCH OF THE MID-LEVEL
Q-VECTOR CONV NNE ACROSS MN AND WESTERN LAKE SUPERIOR.
ADDITIONALLY...THE LEFT-EXIT OF A STRENGTHENING 110KT UPPER JET
STREAK WILL PASS WEST OF THE CWA. WITH PWATS SURPASSING 1.5 IN...A
BAND OF HEAVY RAIN SHOULD DEVELOP WEST OF THE CWA...POSSIBLY
CLIPPING THE FAR WEST. MEANWHILE...STEADY LIGHT TO MODERATE RAIN
ASSOCIATED WITH THE WAA IS EXPECTED FOR THE REMAINDER OF THE CWA
THROUGH THE NIGHT. DYNAMICS ARE FAVORABLE FOR POSSIBLE THUNDER
ACROSS THE WEST...WHILE MUCAPE OF AROUND 500 J/KG WILL BE ENOUGH FOR
SOME EMBEDDED THUNDER ACROSS THE EAST.
A RATHER PRONOUNCED MID-LEVEL DRY SLOT WILL QUICKLY SPREAD ACROSS
THE CWA FROM THE SW WEDNESDAY MORNING AS THE SFC LOW TRACKS NNE
ACROSS WESTERN LAKE SUPERIOR. STEEPENING MID-LEVEL LAPSE RATES AHEAD
OF THIS DRY SLOT WILL ALLOW FOR SOME EMBEDDED THUNDERSTORMS. SHOWERS
BECOME ISOLATED ACROSS THE CENTRAL UNDER THE DRY SLOT...BUT CONTINUE
FOR THE FAR WEST AND EAST DURING THE AFTERNOON. ALSO...S TO SW WINDS
LOOK TO GET QUITE GUSTY ACROSS THE CENTRAL AND EAST AHEAD OF AND
UNDER THE DRY SLOT.
WEDNESDAY NIGHT AND THURSDAY...WRAP AROUND MOISTURE WILL KEEP RAIN
CHANCES ACROSS MOST OF THE CWA...PARTICULARLY ALONG LAKE THE WEST
WIND BELTS OF LAKE SUPERIOR...THROUGH THURSDAY BEFORE SYNOPTIC
FORCING AND MOISTURE DEPART THURSDAY NIGHT. H8 TEMPS DOWN TO 5C
COMBINED WITH A STRONG GRADIENT FLOW AND RELATIVELY WARM LAKE TEMPS
WILL ALLOW FOR VERY BREEZY WEST WINDS ON THURSDAY. GUSTS TO 40MPH
ACROSS THE KEWEENAW AND WESTERN SHORE ARE NOT OUT OF THE QUESTION.
FRIDAY THROUGH SUNDAY...WEAK MID-LEVEL CYCLONIC FLOW WILL CONTINUE
OVER THE CWA ON FRIDAY...RESULTING IN VERY SMALL CHANCES OF RAIN
WITH ANY SUBTLE EMBEDDED SHORTWAVE. WILL MAINTAIN A DRY FORECAST
GIVEN THE LITTLE CHANCE OF ANYTHING MATERIALIZING. SATURDAY LOOKS TO
BE ANOTHER WARM DAY AS MID-LEVEL RIDGING AND INCREASING H8 TEMPS
BUILD ACROSS THE UPPER GREAT LAKES. TEMPS SHOULD REACH THE 80S FOR
MOST OF THE CWA. MID-LEVEL TROUGHING GLANCING THE NORTHERN HIGH
PLAINS EARLY SATURDAY WILL RESULT IN LOW-PRESSURE DEVELOPMENT ACROSS
THE NORTHERN PLAINS AND SOUTH-CENTRAL CANADA. GUIDANCE SHOWS SOME
DIFFERENCES IN THE TIMING OF AN ASSOCIATED COLD FRONT CROSSING THE
CWA...BUT A ROUND OF SHOWERS AND STORMS SHOULD AFFECT THE AREA
SOMETIME LATE SATURDAY NIGHT THROUGH SUNDAY. EITHER WAY...GUSTY
SOUTHERLY WINDS OVER 25MPH WILL LIKELY OCCUR AHEAD OF THIS FRONT
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 137 PM EDT MON AUG 17 2015
DRIER AIR WILL MAKE SOME INROADS INTO THE AREA THIS AFTN BEHIND A
COLD FRONT THAT HAS SLIPPED SE OF UPPER MI. AS A RESULT...EXPECT
KIWD TO BREAK OUT FROM MVFR TO VFR IN THE NEXT COUPLE OF HRS. KCMX
WILL REMAIN VFR. DRYING WILL BE SLOWER AT KSAW...AND THIS SHOULD
LEAD TO MVFR CIGS PREVAILING FOR MUCH OF THE AFTN INTO THE EARLY
EVENING. AFTER A BREAK TO VFR THIS EVENING AT KSAW...MVFR CIGS MAY
RETURN LATE TONIGHT/TUE MORNING UNDER LIGHT UPSLOPE FLOW OFF LAKE
SUPERIOR. KIWD/KCMX SHOULD REMAIN VFR...THOUGH THERE IS A LOW
POTENTIAL FOR FOG DEVELOPMENT LATE TONIGHT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 534 AM EDT MON AUG 17 2015
WINDS WILL REMAIN AT OR BELOW 20 KNOTS THROUGH TONIGHT...THEN
NE WINDS WILL INCREASE TO UP TO 30 KNOTS TUE INTO TUE NIGHT AS A LOW
PRES SYSTEM MOVES INTO THE UPPER MS VALLEY. WINDS MAY TEMPORARILY
DIMINISH WED AS A LOW PRES SYSTEM MOVES TOWARD LAKE SUPERIOR.
HOWEVER...AS THE STRONG LOW DEPARS LATE WED NIGHT INTO THU SOME WRLY
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JSL
SHORT TERM...JLB
LONG TERM...TK
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
ISSUED BY NATIONAL WEATHER SERVICE GAYLORD MI
1113 AM EDT MON AUG 17 2015
.UPDATE...
ISSUED AT 1110 AM EDT MON AUG 17 2015
500 MB SHORTWAVE TROUGH MOVING FROM NE IOWA INTO WISCONSIN, IS
PRODUCING SHOWERS ALONG A COLD FRONT THAT STRETCHES FROM AROUND
CYXZ (WAWA) TO NEAR KLSE. THE NORTHERN END HAS DIMINISHED OVER THE
LAST FEW HOURS AS THE SYSTEM HAS BIFURCATED SOMEWHAT, BUT WITH THE
500 MB SHORTWAVE, A NEW AREA OF RAIN IS MOVING OUT OF CENTRAL
WISCONSIN AND INTO W AND C UPPER. THIS IS EXPECTED TO CONTINUE
INTO THE AFTERNOON, SO HAVE BUMPED UP THE POPS ALONG THE FRONT FOR
THE NEXT FEW HOURS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 530 AM EDT MON AUG 17 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A BROAD TROUGH FROM HUDSON BAY
INTO THE NRN PLAINS AND A RIDGE OVER THE ERN CONUS RESULTING IN WSW
MID/UPPER LEVEL FLOW THROUGH THE NRN GREAT LAKES. AT THE SFC...A
COLD FRONT EXTENDED FROM THE SRN END OF JAMES BAY THROUGH ERN
UPPER MI INTO NE WI. A WEAK SHRTWV COMBINED WITH MID LEVEL FGEN
AND UPPER LEVEL DIV WITH THE RIGHT ENTRANCE OF THE 250-300 MB JET
OVER NW ONTARIO SUPPORTED SCT/NMRS SHRA ACROSS CNTRL AND ERN UPPER
MI. THE AXIS OF GREATER INSTABILITY/MUCAPE TO AROUND 1K J/KG
LINGERED OVER THE SE CWA AND IN COMBINATION WITH 0-6KM SHEAR TO
NEAR 40 KNOTS SUPPORTED CLUSTERS OF STRONG/SVR STORMS OVER THE SRN
CWA OVERNIGHT NEAR THE COLD FRONT.
TODAY...EXPECT THAT THE 850-700 MB FRONTAL BOUNDARY WILL LINGER OVER
THE AREA EVEN AS THE SFC FRONT CONTINUES TO SLIDE TO THE SE. AS
ANOTHER WEAK SHORTWAVE MOVES TOWARD THE AREA...SCT SHOWERS ARE
EXPECTED TO CONTINUE OVER THE SE HALF OF UPPER MI. THERE MAY BE JUST
ENOUGH LINGERING MUCAPE FOR SOME TSRA OVER THE FAR SE.
OTHERWISE...MUCH COOLER CONDITIONS WILL PREVAIL WITH MAX TEMPS IN
THE LOWER 70S AND DEWPOINTS DROPPING INTO THE MID AND UPPER 50S NW
TO THE LOWER 60S SE.
TONIGHT...SHOWERS CHANCES...MAINLY OVER THE SOUTH AND EAST WILL
CONTINUE TO DIMINISH WITH THE MAIN FRONTAL BOUNDARY LINGERING
FARTHER TO THE SOUTH.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 523 AM EDT MON AUG 17 2015
SEASONABLY COOL WEATHER WILL PREVAIL FOR THE MIDDLE OF THE WEEK
AMIDST RAIN. TEMPS WILL INCH BACK TO ABOVE AVERAGE BY SATURDAY
BEFORE A COLD FRONT BRINGS A CHANCE FOR RAIN AND ANOTHER COOL-DOWN
ON SUNDAY.
TUESDAY...DEEP MID-LEVEL TROUGHING WILL BE ONGOING ACROSS THE
NORTHERN AND CENTRAL PLAINS BY TUESDAY MORNING...WITH A LEE CYCLONE
FORMING OVER THE CENTRAL HIGH PLAINS. MEANWHILE...THE COLD FRONT
THAT CROSSED THE AREA EARLIER TODAY WILL HAVE WASHED OUT ACROSS
NORTHERN WI...WITH THE H7 TO H8 FRONT LINGERING AS FAR NORTH AS THE
SOUTH-CENTRAL CWA. WIDESPREAD WAA AHEAD OF THE DEVELOPING LOW LOOKS
TO HOLD OFF UNTIL TUESDAY NIGHT...THOUGH MID-LEVEL FGEN BECOMES
APPARENT BY THE AFTERNOON. WITH MODELS BEGINNING TO BACK OFF ON THE
SOUTHWARD PUSH OF DEEP DRY AIR BEHIND THE FRONT TODAY...THINK THAT
AT LEAST SOME LIGHT RAIN WILL BE POSSIBLE BY TUESDAY AFTERNOON.
GIVEN THAT WAA/ISENTROPIC LIFT IS STILL MINIMAL...CONTINUED WITH
JUST SLIGHT CHANCES IN THE FORECAST.
TUESDAY NIGHT AND WEDNESDAY...LOW-LEVEL MOISTURE TRANSPORT AND
ISENTROPIC LIFT QUICKLY INCREASE TUESDAY EVENING AS THE SFC LOW
STRENGTHENS AND NEARS. THE MID-LEVEL SHORTWAVE BEGINS TO TAKE ON
MORE OF A NEGATIVE TILT BY THIS TIME...SENDING MUCH OF THE MID-LEVEL
Q-VECTOR CONV NNE ACROSS MN AND WESTERN LAKE SUPERIOR.
ADDITIONALLY...THE LEFT-EXIT OF A STRENGTHENING 110KT UPPER JET
STREAK WILL PASS WEST OF THE CWA. WITH PWATS SURPASSING 1.5 IN...A
BAND OF HEAVY RAIN SHOULD DEVELOP WEST OF THE CWA...POSSIBLY
CLIPPING THE FAR WEST. MEANWHILE...STEADY LIGHT TO MODERATE RAIN
ASSOCIATED WITH THE WAA IS EXPECTED FOR THE REMAINDER OF THE CWA
THROUGH THE NIGHT. DYNAMICS ARE FAVORABLE FOR POSSIBLE THUNDER
ACROSS THE WEST...WHILE MUCAPE OF AROUND 500 J/KG WILL BE ENOUGH FOR
SOME EMBEDDED THUNDER ACROSS THE EAST.
A RATHER PRONOUNCED MID-LEVEL DRY SLOT WILL QUICKLY SPREAD ACROSS
THE CWA FROM THE SW WEDNESDAY MORNING AS THE SFC LOW TRACKS NNE
ACROSS WESTERN LAKE SUPERIOR. STEEPENING MID-LEVEL LAPSE RATES AHEAD
OF THIS DRY SLOT WILL ALLOW FOR SOME EMBEDDED THUNDERSTORMS. SHOWERS
BECOME ISOLATED ACROSS THE CENTRAL UNDER THE DRY SLOT...BUT CONTINUE
FOR THE FAR WEST AND EAST DURING THE AFTERNOON. ALSO...S TO SW WINDS
LOOK TO GET QUITE GUSTY ACROSS THE CENTRAL AND EAST AHEAD OF AND
UNDER THE DRY SLOT.
WEDNESDAY NIGHT AND THURSDAY...WRAP AROUND MOISTURE WILL KEEP RAIN
CHANCES ACROSS MOST OF THE CWA...PARTICULARLY ALONG LAKE THE WEST
WIND BELTS OF LAKE SUPERIOR...THROUGH THURSDAY BEFORE SYNOPTIC
FORCING AND MOISTURE DEPART THURSDAY NIGHT. H8 TEMPS DOWN TO 5C
COMBINED WITH A STRONG GRADIENT FLOW AND RELATIVELY WARM LAKE TEMPS
WILL ALLOW FOR VERY BREEZY WEST WINDS ON THURSDAY. GUSTS TO 40MPH
ACROSS THE KEWEENAW AND WESTERN SHORE ARE NOT OUT OF THE QUESTION.
FRIDAY THROUGH SUNDAY...WEAK MID-LEVEL CYCLONIC FLOW WILL CONTINUE
OVER THE CWA ON FRIDAY...RESULTING IN VERY SMALL CHANCES OF RAIN
WITH ANY SUBTLE EMBEDDED SHORTWAVE. WILL MAINTAIN A DRY FORECAST
GIVEN THE LITTLE CHANCE OF ANYTHING MATERIALIZING. SATURDAY LOOKS TO
BE ANOTHER WARM DAY AS MID-LEVEL RIDGING AND INCREASING H8 TEMPS
BUILD ACROSS THE UPPER GREAT LAKES. TEMPS SHOULD REACH THE 80S FOR
MOST OF THE CWA. MID-LEVEL TROUGHING GLANCING THE NORTHERN HIGH
PLAINS EARLY SATURDAY WILL RESULT IN LOW-PRESSURE DEVELOPMENT ACROSS
THE NORTHERN PLAINS AND SOUTH-CENTRAL CANADA. GUIDANCE SHOWS SOME
DIFFERENCES IN THE TIMING OF AN ASSOCIATED COLD FRONT CROSSING THE
CWA...BUT A ROUND OF SHOWERS AND STORMS SHOULD AFFECT THE AREA
SOMETIME LATE SATURDAY NIGHT THROUGH SUNDAY. EITHER WAY...GUSTY
SOUTHERLY WINDS OVER 25MPH WILL LIKELY OCCUR AHEAD OF THIS FRONT
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 723 AM EDT MON AUG 17 2015
SINCE A COLD FRONT WILL STALL JUST TO THE SOUTH OF UPPER MICHIGAN
TODAY...AN UPPER DISTURBANCE TRACKING ALONG THIS BOUNDARY WILL
BRING A CONTINUED CHC OF MORE -SHRA INTO THE AFTERNOON AT SAW.
WITH A WSHFT TO AN UPSLOPE NNE DIRECTIN IN THE AFTN AND MORE
LINGERING MOISUTRE...MVFR CIGS ARE LIKELY AT SAW FOR A TIME.
EXPECT ENOUGH LINGERING LOW LEVEL MOISTURE FOR SOME MVFR FOG TO
ALSO DEVELOP. SINCE CMX AND IWD WILL BE FARTHER FROM THE FRONT AND
DEEPER INTO THE INCOMING DRY AIRMASS...VFR CONDITIONS WILL REMAIN
THE RULE THERE
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 534 AM EDT MON AUG 17 2015
WINDS WILL REMAIN AT OR BELOW 20 KNOTS THROUGH TONIGHT...THEN
NE WINDS WILL INCREASE TO UP TO 30 KNOTS TUE INTO TUE NIGHT AS A LOW
PRES SYSTEM MOVES INTO THE UPPER MS VALLEY. WINDS MAY TEMPORARILY
DIMINISH WED AS A LOW PRES SYSTEM MOVES TOWARD LAKE SUPERIOR.
HOWEVER...AS THE STRONG LOW DEPARS LATE WED NIGHT INTO THU SOME WRLY
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LS...NONE.
LM...NONE.
&&
$$
UPDATE...JSL
SHORT TERM...JLB
LONG TERM...TK
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
723 AM EDT MON AUG 17 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 530 AM EDT MON AUG 17 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A BROAD TROUGH FROM HUDSON BAY
INTO THE NRN PLAINS AND A RIDGE OVER THE ERN CONUS RESULTING IN WSW
MID/UPPER LEVEL FLOW THROUGH THE NRN GREAT LAKES. AT THE SFC...A
COLD FRONT EXTENDED FROM THE SRN END OF JAMES BAY THROUGH ERN UPPPER
MI INTO NE WI. A WEAK SHRTWV COMBINED WITH MID LEVEL FGEN AND UPPER
LEVEL DIV WITH THE RIGHT ENTRANCE OF THE 250-300 MB JET OVER NW
ONTARIO SUPPORTED SCT/NMRS SHRA ACROSS CNTRL AND ERN UPPER MI. THE
AXIS OF GREATER INSTABILITY/MUCAPE TO AROUND 1K J/KG LINGERED OVER
THE SE CWA AND IN COMBINATION WITH 0-6KM SHEAR TO NEAR 40 KNOTS
SUPPORTED CLUSTERS OF STRONG/SVR STORMS OVER THE SRN CWA OVERNIGHT
NEAR THE COLD FRONT.
TODAY...EXPECT THAT THE 850-700 MB FRONTAL BOUNDARY WILL LINGER OVER
THE AREA EVEN AS THE SFC FRONT CONTINUES TO SLIDE TO THE SE. AS
ANOTHER WEAK SHORTWAVE MOVES TOWARD THE AREA...SCT SHOWERS ARE
EXPECTED TO CONTINUE OVER THE SE HALF OF UPPER MI. THERE MAY BE JUST
ENOUGH LINGERING MUCPAE FOR SOME TSRA OVER THE FAR SE.
OTHERWISE...MUCH COOLER CONDITIONS WILL PREVAI WITH MAX TEMPS IN THE
LOWER 70S AND DEWPOINTS DROPPING INTO THE MID AND UPPER 50S NW TO THE
LOWER 60S SE.
TONIGHT...SHOWERS CHANCES...MAINLY OVER THE SOUTH AND EAST WILL
CONTINUE TO DIMINISH WITH THE MAIN FRONTAL BOUNDARY LINGERING
FARTHER TO THE SOUTH.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 523 AM EDT MON AUG 17 2015
SEASONABLY COOL WEATHER WILL PREVAIL FOR THE MIDDLE OF THE WEEK
AMIDST RAIN. TEMPS WILL INCH BACK TO ABOVE AVERAGE BY SATURDAY
BEFORE A COLD FRONT BRINGS A CHANCE FOR RAIN AND ANOTHER COOL-DOWN
ON SUNDAY.
TUESDAY...DEEP MID-LEVEL TROUGHING WILL BE ONGOING ACROSS THE
NORTHERN AND CENTRAL PLAINS BY TUESDAY MORNING...WITH A LEE CYCLONE
FORMING OVER THE CENTRAL HIGH PLAINS. MEANWHILE...THE COLD FRONT
THAT CROSSED THE AREA EARLIER TODAY WILL HAVE WASHED OUT ACROSS
NORTHERN WI...WITH THE H7 TO H8 FRONT LINGERING AS FAR NORTH AS THE
SOUTH-CENTRAL CWA. WIDESPREAD WAA AHEAD OF THE DEVELOPING LOW LOOKS
TO HOLD OFF UNTIL TUESDAY NIGHT...THOUGH MID-LEVEL FGEN BECOMES
APPARENT BY THE AFTERNOON. WITH MODELS BEGINNING TO BACK OFF ON THE
SOUTHWARD PUSH OF DEEP DRY AIR BEHIND THE FRONT TODAY...THINK THAT
AT LEAST SOME LIGHT RAIN WILL BE POSSIBLE BY TUESDAY AFTERNOON.
GIVEN THAT WAA/ISENTROPIC LIFT IS STILL MINIMAL...CONTINUED WITH
JUST SLIGHT CHANCES IN THE FORECAST.
TUESDAY NIGHT AND WEDNESDAY...LOW-LEVEL MOISTURE TRANSPORT AND
ISENTROPIC LIFT QUICKLY INCREASE TUESDAY EVENING AS THE SFC LOW
STRENGTHENS AND NEARS. THE MID-LEVEL SHORTWAVE BEGINS TO TAKE ON
MORE OF A NEGATIVE TILT BY THIS TIME...SENDING MUCH OF THE MID-LEVEL
Q-VECTOR CONV NNE ACROSS MN AND WESTERN LAKE SUPERIOR.
ADDITIONALLY...THE LEFT-EXIT OF A STRENGTHENING 110KT UPPER JET
STREAK WILL PASS WEST OF THE CWA. WITH PWATS SURPASSING 1.5 IN...A
BAND OF HEAVY RAIN SHOULD DEVELOP WEST OF THE CWA...POSSIBLY
CLIPPING THE FAR WEST. MEANWHILE...STEADY LIGHT TO MODERATE RAIN
ASSOCIATED WITH THE WAA IS EXPECTED FOR THE REMAINDER OF THE CWA
THROUGH THE NIGHT. DYNAMICS ARE FAVORABLE FOR POSSIBLE THUNDER
ACROSS THE WEST...WHILE MUCAPE OF AROUND 500 J/KG WILL BE ENOUGH FOR
SOME EMBEDDED THUNDER ACROSS THE EAST.
A RATHER PRONOUNCED MID-LEVEL DRY SLOT WILL QUICKLY SPREAD ACROSS
THE CWA FROM THE SW WEDNESDAY MORNING AS THE SFC LOW TRACKS NNE
ACROSS WESTERN LAKE SUPERIOR. STEEPENING MID-LEVEL LAPSE RATES AHEAD
OF THIS DRY SLOT WILL ALLOW FOR SOME EMBEDDED THUNDERSTORMS. SHOWERS
BECOME ISOLATED ACROSS THE CENTRAL UNDER THE DRY SLOT...BUT CONTINUE
FOR THE FAR WEST AND EAST DURING THE AFTERNOON. ALSO...S TO SW WINDS
LOOK TO GET QUITE GUSTY ACROSS THE CENTRAL AND EAST AHEAD OF AND
UNDER THE DRY SLOT.
WEDNESDAY NIGHT AND THURSDAY...WRAP AROUND MOISTURE WILL KEEP RAIN
CHANCES ACROSS MOST OF THE CWA...PARTICULARLY ALONG LAKE THE WEST
WIND BELTS OF LAKE SUPERIOR...THROUGH THURSDAY BEFORE SYNOPTIC
FORCING AND MOISTURE DEPART THURSDAY NIGHT. H8 TEMPS DOWN TO 5C
COMBINED WITH A STRONG GRADIENT FLOW AND RELATIVELY WARM LAKE TEMPS
WILL ALLOW FOR VERY BREEZY WEST WINDS ON THURSDAY. GUSTS TO 40MPH
ACROSS THE KEWEENAW AND WESTERN SHORE ARE NOT OUT OF THE QUESTION.
FRIDAY THROUGH SUNDAY...WEAK MID-LEVEL CYCLONIC FLOW WILL CONTINUE
OVER THE CWA ON FRIDAY...RESULTING IN VERY SMALL CHANCES OF RAIN
WITH ANY SUBTLE EMBEDDED SHORTWAVE. WILL MAINTAIN A DRY FORECAST
GIVEN THE LITTLE CHANCE OF ANYTHING MATERIALIZING. SATURDAY LOOKS TO
BE ANOTHER WARM DAY AS MID-LEVEL RIDGING AND INCREASING H8 TEMPS
BUILD ACROSS THE UPPER GREAT LAKES. TEMPS SHOULD REACH THE 80S FOR
MOST OF THE CWA. MID-LEVEL TROUGHING GLANCING THE NORTHERN HIGH
PLAINS EARLY SATURDAY WILL RESULT IN LOW-PRESSURE DEVELOPMENT ACROSS
THE NORTHERN PLAINS AND SOUTH-CENTRAL CANADA. GUIDANCE SHOWS SOME
DIFFERENCES IN THE TIMING OF AN ASSOCIATED COLD FRONT CROSSING THE
CWA...BUT A ROUND OF SHOWERS AND STORMS SHOULD AFFECT THE AREA
SOMETIME LATE SATURDAY NIGHT THROUGH SUNDAY. EITHER WAY...GUSTY
SOUTHERLY WINDS OVER 25MPH WILL LIKELY OCCUR AHEAD OF THIS FRONT
SATURDAY INTO SUNDAY MORNING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 723 AM EDT MON AUG 17 2015
SINCE A COLD FRONT WILL STALL JUST TO THE SOUTH OF UPPER MICHIGAN
TODAY...AN UPPER DISTURBANCE TRACKING ALONG THIS BOUNDAY WILL BRING
A CONTINUED CHC OF MORE -SHRA INTO THE AFTERNOON AT SAW. WITH A
WSHFT TO AN UPSLOPE NNE DIRECTIN IN THE AFTN AND MORE LINGERING
MOISUTRE...MVFR CIGS ARE LIKELY AT SAW FOR A TIME. EXPECT ENOUGH
LINGERING LOW LEVEL MOISTURE FOR SOME MVFR FOG TO ALSO DEVELOP.
SINCE CMX AND IWD WILL BE FARTHER FROM THE FRONT AND DEEPER INTO THE
INCOMING DRY AIRMASS...VFR CONDITIONS WILL REMAIN THE RULE THERE
THROUGH THE TAF PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 534 AM EDT MON AUG 17 2015
WINDS WILL REMAIN AT OR BELOW 20 KNOTS THROUGH TONIGHT...THEN
NE WINDS WILL INCREASE TO UP TO 30 KNOTS TUE INTO TUE NIGHT AS A LOW
PRES SYSTEM MOVES INTO THE UPPER MS VALLEY. WINDS MAY TEMPORARILY
DIMINISH WED AS A LOW PRES SYSTEM MOVES TOWARD LAKE SUPERIOR.
HOWEVER...AS THE STRONG LOW DEPARS LATE WED NIGHT INTO THU SOME WRLY
GALE FORCE GUSTS TO 35 KNOTS ARE POSSIBLE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TK
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
538 AM EDT MON AUG 17 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 530 AM EDT MON AUG 17 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A BROAD TROUGH FROM HUDSON BAY
INTO THE NRN PLAINS AND A RIDGE OVER THE ERN CONUS RESULTING IN WSW
MID/UPPER LEVEL FLOW THROUGH THE NRN GREAT LAKES. AT THE SFC...A
COLD FRONT EXTENDED FROM THE SRN END OF JAMES BAY THROUGH ERN UPPPER
MI INTO NE WI. A WEAK SHRTWV COMBINED WITH MID LEVEL FGEN AND UPPER
LEVEL DIV WITH THE RIGHT ENTRANCE OF THE 250-300 MB JET OVER NW
ONTARIO SUPPORTED SCT/NMRS SHRA ACROSS CNTRL AND ERN UPPER MI. THE
AXIS OF GREATER INSTABILITY/MUCAPE TO AROUND 1K J/KG LINGERED OVER
THE SE CWA AND IN COMBINATION WITH 0-6KM SHEAR TO NEAR 40 KNOTS
SUPPORTED CLUSTERS OF STRONG/SVR STORMS OVER THE SRN CWA OVERNIGHT
NEAR THE COLD FRONT.
TODAY...EXPECT THAT THE 850-700 MB FRONTAL BOUNDARY WILL LINGER OVER
THE AREA EVEN AS THE SFC FRONT CONTINUES TO SLIDE TO THE SE. AS
ANOTHER WEAK SHORTWAVE MOVES TOWARD THE AREA...SCT SHOWERS ARE
EXPECTED TO CONTINUE OVER THE SE HALF OF UPPER MI. THERE MAY BE JUST
ENOUGH LINGERING MUCPAE FOR SOME TSRA OVER THE FAR SE.
OTHERWISE...MUCH COOLER CONDITIONS WILL PREVAI WITH MAX TEMPS IN THE
LOWER 70S AND DEWPOINTS DROPPING INTO THE MID AND UPPER 50S NW TO THE
LOWER 60S SE.
TONIGHT...SHOWERS CHANCES...MAINLY OVER THE SOUTH AND EAST WILL
CONTINUE TO DIMINISH WITH THE MAIN FRONTAL BOUNDARY LINGERING
FARTHER TO THE SOUTH.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 523 AM EDT MON AUG 17 2015
SEASONABLY COOL WEATHER WILL PREVAIL FOR THE MIDDLE OF THE WEEK
AMIDST RAIN. TEMPS WILL INCH BACK TO ABOVE AVERAGE BY SATURDAY
BEFORE A COLD FRONT BRINGS A CHANCE FOR RAIN AND ANOTHER COOL-DOWN
ON SUNDAY.
TUESDAY...DEEP MID-LEVEL TROUGHING WILL BE ONGOING ACROSS THE
NORTHERN AND CENTRAL PLAINS BY TUESDAY MORNING...WITH A LEE CYCLONE
FORMING OVER THE CENTRAL HIGH PLAINS. MEANWHILE...THE COLD FRONT
THAT CROSSED THE AREA EARLIER TODAY WILL HAVE WASHED OUT ACROSS
NORTHERN WI...WITH THE H7 TO H8 FRONT LINGERING AS FAR NORTH AS THE
SOUTH-CENTRAL CWA. WIDESPREAD WAA AHEAD OF THE DEVELOPING LOW LOOKS
TO HOLD OFF UNTIL TUESDAY NIGHT...THOUGH MID-LEVEL FGEN BECOMES
APPARENT BY THE AFTERNOON. WITH MODELS BEGINNING TO BACK OFF ON THE
SOUTHWARD PUSH OF DEEP DRY AIR BEHIND THE FRONT TODAY...THINK THAT
AT LEAST SOME LIGHT RAIN WILL BE POSSIBLE BY TUESDAY AFTERNOON.
GIVEN THAT WAA/ISENTROPIC LIFT IS STILL MINIMAL...CONTINUED WITH
JUST SLIGHT CHANCES IN THE FORECAST.
TUESDAY NIGHT AND WEDNESDAY...LOW-LEVEL MOISTURE TRANSPORT AND
ISENTROPIC LIFT QUICKLY INCREASE TUESDAY EVENING AS THE SFC LOW
STRENGTHENS AND NEARS. THE MID-LEVEL SHORTWAVE BEGINS TO TAKE ON
MORE OF A NEGATIVE TILT BY THIS TIME...SENDING MUCH OF THE MID-LEVEL
Q-VECTOR CONV NNE ACROSS MN AND WESTERN LAKE SUPERIOR.
ADDITIONALLY...THE LEFT-EXIT OF A STRENGTHENING 110KT UPPER JET
STREAK WILL PASS WEST OF THE CWA. WITH PWATS SURPASSING 1.5 IN...A
BAND OF HEAVY RAIN SHOULD DEVELOP WEST OF THE CWA...POSSIBLY
CLIPPING THE FAR WEST. MEANWHILE...STEADY LIGHT TO MODERATE RAIN
ASSOCIATED WITH THE WAA IS EXPECTED FOR THE REMAINDER OF THE CWA
THROUGH THE NIGHT. DYNAMICS ARE FAVORABLE FOR POSSIBLE THUNDER
ACROSS THE WEST...WHILE MUCAPE OF AROUND 500 J/KG WILL BE ENOUGH FOR
SOME EMBEDDED THUNDER ACROSS THE EAST.
A RATHER PRONOUNCED MID-LEVEL DRY SLOT WILL QUICKLY SPREAD ACROSS
THE CWA FROM THE SW WEDNESDAY MORNING AS THE SFC LOW TRACKS NNE
ACROSS WESTERN LAKE SUPERIOR. STEEPENING MID-LEVEL LAPSE RATES AHEAD
OF THIS DRY SLOT WILL ALLOW FOR SOME EMBEDDED THUNDERSTORMS. SHOWERS
BECOME ISOLATED ACROSS THE CENTRAL UNDER THE DRY SLOT...BUT CONTINUE
FOR THE FAR WEST AND EAST DURING THE AFTERNOON. ALSO...S TO SW WINDS
LOOK TO GET QUITE GUSTY ACROSS THE CENTRAL AND EAST AHEAD OF AND
UNDER THE DRY SLOT.
WEDNESDAY NIGHT AND THURSDAY...WRAP AROUND MOISTURE WILL KEEP RAIN
CHANCES ACROSS MOST OF THE CWA...PARTICULARLY ALONG LAKE THE WEST
WIND BELTS OF LAKE SUPERIOR...THROUGH THURSDAY BEFORE SYNOPTIC
FORCING AND MOISTURE DEPART THURSDAY NIGHT. H8 TEMPS DOWN TO 5C
COMBINED WITH A STRONG GRADIENT FLOW AND RELATIVELY WARM LAKE TEMPS
WILL ALLOW FOR VERY BREEZY WEST WINDS ON THURSDAY. GUSTS TO 40MPH
ACROSS THE KEWEENAW AND WESTERN SHORE ARE NOT OUT OF THE QUESTION.
FRIDAY THROUGH SUNDAY...WEAK MID-LEVEL CYCLONIC FLOW WILL CONTINUE
OVER THE CWA ON FRIDAY...RESULTING IN VERY SMALL CHANCES OF RAIN
WITH ANY SUBTLE EMBEDDED SHORTWAVE. WILL MAINTAIN A DRY FORECAST
GIVEN THE LITTLE CHANCE OF ANYTHING MATERIALIZING. SATURDAY LOOKS TO
BE ANOTHER WARM DAY AS MID-LEVEL RIDGING AND INCREASING H8 TEMPS
BUILD ACROSS THE UPPER GREAT LAKES. TEMPS SHOULD REACH THE 80S FOR
MOST OF THE CWA. MID-LEVEL TROUGHING GLANCING THE NORTHERN HIGH
PLAINS EARLY SATURDAY WILL RESULT IN LOW-PRESSURE DEVELOPMENT ACROSS
THE NORTHERN PLAINS AND SOUTH-CENTRAL CANADA. GUIDANCE SHOWS SOME
DIFFERENCES IN THE TIMING OF AN ASSOCIATED COLD FRONT CROSSING THE
CWA...BUT A ROUND OF SHOWERS AND STORMS SHOULD AFFECT THE AREA
SOMETIME LATE SATURDAY NIGHT THROUGH SUNDAY. EITHER WAY...GUSTY
SOUTHERLY WINDS OVER 25MPH WILL LIKELY OCCUR AHEAD OF THIS FRONT
SATURDAY INTO SUNDAY MORNING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 132 AM EDT MON AUG 17 2015
SOME -SHRA/PERHAPS A TS IN ADVANCE OF A COLD FNT APRCHG FM THE W WL
IMPACT MAINLY SAW DURING THE EARLY MRNG HRS. THE ARRIVAL OF DRIER
LLVL AIR WL ENSURE CONDITIONS REMAIN VFR AT CMX AND IWD EVEN IF SOME
-SHRA FALL THERE. BUT SAW COULD PICK UP MVFR CONDITIONS WITH MORE
HUMID LLVL AIR LINGERING. SINCE THE COLD FNT WL STALL JUST TO THE S
ON MON...AN UPPER DISTURBANCE TRACKING ALONG THIS BNDRY WL BRING A
CONTINUED CHC OF MORE -SHRA INTO THE AFTN AT SAW. WITH A WSHFT TO
AN UPSLOPE NNE DIRECTIN IN THE AFTN AND MORE LINGERING MSTR...MVFR
CIGS ARE LIKELY AT SAW FOR A TIME. SINCE CMX AND IWD WL BE FARTHER
FM THE FNT AND DEEPER INTO THE INCOMING DRY AIRMASS...VFR CONDITIONS
WL REMAIN THE RULE THERE THRU THE TAF PERIOD..
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 534 AM EDT MON AUG 17 2015
WINDS WILL REMAIN AT OR BELOW 20 KNOTS THROUGH TONIGHT...THEN
NE WINDS WILL INCREASE TO UP TO 30 KNOTS TUE INTO TUE NIGHT AS A LOW
PRES SYSTEM MOVES INTO THE UPPER MS VALLEY. WINDS MAY TEMPORARILY
DIMINISH WED AS A LOW PRES SYSTEM MOVES TOWARD LAKE SUPERIOR.
HOWEVER...AS THE STRONG LOW DEPARS LATE WED NIGHT INTO THU SOME WRLY
GALE FORCE GUSTS TO 35 KNOTS ARE POSSIBLE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TK
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
531 AM EDT MON AUG 17 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 530 AM EDT MON AUG 17 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A BROAD TROUGH FROM HUDSON BAY
INTO THE NRN PLAINS AND A RIDGE OVER THE ERN CONUS RESULTING IN WSW
MID/UPPER LEVEL FLOW THROUGH THE NRN GREAT LAKES. AT THE SFC...A
COLD FRONT EXTENDED FROM THE SRN END OF JAMES BAY THROUGH ERN UPPPER
MI INTO NE WI. A WEAK SHRTWV COMBINED WITH MID LEVEL FGEN AND UPPER
LEVEL DIV WITH THE RIGHT ENTRANCE OF THE 250-300 MB JET OVER NW
ONTARIO SUPPORTED SCT/NMRS SHRA ACROSS CNTRL AND ERN UPPER MI. THE
AXIS OF GREATER INSTABILITY/MUCAPE TO AROUND 1K J/KG LINGERED OVER
THE SE CWA AND IN COMBINATION WITH 0-6KM SHEAR TO NEAR 40 KNOTS
SUPPORTED CLUSTERS OF STRONG/SVR STORMS OVER THE SRN CWA OVERNIGHT
NEAR THE COLD FRONT.
TODAY...EXPECT THAT THE 850-700 MB FRONTAL BOUNDARY WILL LINGER OVER
THE AREA EVEN AS THE SFC FRONT CONTINUES TO SLIDE TO THE SE. AS
ANOTHER WEAK SHORTWAVE MOVES TOWARD THE AREA...SCT SHOWERS ARE
EXPECTED TO CONTINUE OVER THE SE HALF OF UPPER MI. THERE MAY BE JUST
ENOUGH LINGERING MUCPAE FOR SOME TSRA OVER THE FAR SE.
OTHERWISE...MUCH COOLER CONDITIONS WILL PREVAI WITH MAX TEMPS IN THE
LOWER 70S AND DEWPOINTS DROPPING INTO THE MID AND UPPER 50S NW TO THE
LOWER 60S SE.
TONIGHT...SHOWERS CHANCES...MAINLY OVER THE SOUTH AND EAST WILL
CONTINUE TO DIMINISH WITH THE MAIN FRONTAL BOUNDARY LINGERING
FARTHER TO THE SOUTH.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 523 AM EDT MON AUG 17 2015
SEASONABLY COOL WEATHER WILL PREVAIL FOR THE MIDDLE OF THE WEEK
AMIDST RAIN. TEMPS WILL INCH BACK TO ABOVE AVERAGE BY SATURDAY
BEFORE A COLD FRONT BRINGS A CHANCE FOR RAIN AND ANOTHER COOL-DOWN
ON SUNDAY.
TUESDAY...DEEP MID-LEVEL TROUGHING WILL BE ONGOING ACROSS THE
NORTHERN AND CENTRAL PLAINS BY TUESDAY MORNING...WITH A LEE CYCLONE
FORMING OVER THE CENTRAL HIGH PLAINS. MEANWHILE...THE COLD FRONT
THAT CROSSED THE AREA EARLIER TODAY WILL HAVE WASHED OUT ACROSS
NORTHERN WI...WITH THE H7 TO H8 FRONT LINGERING AS FAR NORTH AS THE
SOUTH-CENTRAL CWA. WIDESPREAD WAA AHEAD OF THE DEVELOPING LOW LOOKS
TO HOLD OFF UNTIL TUESDAY NIGHT...THOUGH MID-LEVEL FGEN BECOMES
APPARENT BY THE AFTERNOON. WITH MODELS BEGINNING TO BACK OFF ON THE
SOUTHWARD PUSH OF DEEP DRY AIR BEHIND THE FRONT TODAY...THINK THAT
AT LEAST SOME LIGHT RAIN WILL BE POSSIBLE BY TUESDAY AFTERNOON.
GIVEN THAT WAA/ISENTROPIC LIFT IS STILL MINIMAL...CONTINUED WITH
JUST SLIGHT CHANCES IN THE FORECAST.
TUESDAY NIGHT AND WEDNESDAY...LOW-LEVEL MOISTURE TRANSPORT AND
ISENTROPIC LIFT QUICKLY INCREASE TUESDAY EVENING AS THE SFC LOW
STRENGTHENS AND NEARS. THE MID-LEVEL SHORTWAVE BEGINS TO TAKE ON
MORE OF A NEGATIVE TILT BY THIS TIME...SENDING MUCH OF THE MID-LEVEL
Q-VECTOR CONV NNE ACROSS MN AND WESTERN LAKE SUPERIOR.
ADDITIONALLY...THE LEFT-EXIT OF A STRENGTHENING 110KT UPPER JET
STREAK WILL PASS WEST OF THE CWA. WITH PWATS SURPASSING 1.5 IN...A
BAND OF HEAVY RAIN SHOULD DEVELOP WEST OF THE CWA...POSSIBLY
CLIPPING THE FAR WEST. MEANWHILE...STEADY LIGHT TO MODERATE RAIN
ASSOCIATED WITH THE WAA IS EXPECTED FOR THE REMAINDER OF THE CWA
THROUGH THE NIGHT. DYNAMICS ARE FAVORABLE FOR POSSIBLE THUNDER
ACROSS THE WEST...WHILE MUCAPE OF AROUND 500 J/KG WILL BE ENOUGH FOR
SOME EMBEDDED THUNDER ACROSS THE EAST.
A RATHER PRONOUNCED MID-LEVEL DRY SLOT WILL QUICKLY SPREAD ACROSS
THE CWA FROM THE SW WEDNESDAY MORNING AS THE SFC LOW TRACKS NNE
ACROSS WESTERN LAKE SUPERIOR. STEEPENING MID-LEVEL LAPSE RATES AHEAD
OF THIS DRY SLOT WILL ALLOW FOR SOME EMBEDDED THUNDERSTORMS. SHOWERS
BECOME ISOLATED ACROSS THE CENTRAL UNDER THE DRY SLOT...BUT CONTINUE
FOR THE FAR WEST AND EAST DURING THE AFTERNOON. ALSO...S TO SW WINDS
LOOK TO GET QUITE GUSTY ACROSS THE CENTRAL AND EAST AHEAD OF AND
UNDER THE DRY SLOT.
WEDNESDAY NIGHT AND THURSDAY...WRAP AROUND MOISTURE WILL KEEP RAIN
CHANCES ACROSS MOST OF THE CWA...PARTICULARLY ALONG LAKE THE WEST
WIND BELTS OF LAKE SUPERIOR...THROUGH THURSDAY BEFORE SYNOPTIC
FORCING AND MOISTURE DEPART THURSDAY NIGHT. H8 TEMPS DOWN TO 5C
COMBINED WITH A STRONG GRADIENT FLOW AND RELATIVELY WARM LAKE TEMPS
WILL ALLOW FOR VERY BREEZY WEST WINDS ON THURSDAY. GUSTS TO 40MPH
ACROSS THE KEWEENAW AND WESTERN SHORE ARE NOT OUT OF THE QUESTION.
FRIDAY THROUGH SUNDAY...WEAK MID-LEVEL CYCLONIC FLOW WILL CONTINUE
OVER THE CWA ON FRIDAY...RESULTING IN VERY SMALL CHANCES OF RAIN
WITH ANY SUBTLE EMBEDDED SHORTWAVE. WILL MAINTAIN A DRY FORECAST
GIVEN THE LITTLE CHANCE OF ANYTHING MATERIALIZING. SATURDAY LOOKS TO
BE ANOTHER WARM DAY AS MID-LEVEL RIDGING AND INCREASING H8 TEMPS
BUILD ACROSS THE UPPER GREAT LAKES. TEMPS SHOULD REACH THE 80S FOR
MOST OF THE CWA. MID-LEVEL TROUGHING GLANCING THE NORTHERN HIGH
PLAINS EARLY SATURDAY WILL RESULT IN LOW-PRESSURE DEVELOPMENT ACROSS
THE NORTHERN PLAINS AND SOUTH-CENTRAL CANADA. GUIDANCE SHOWS SOME
DIFFERENCES IN THE TIMING OF AN ASSOCIATED COLD FRONT CROSSING THE
CWA...BUT A ROUND OF SHOWERS AND STORMS SHOULD AFFECT THE AREA
SOMETIME LATE SATURDAY NIGHT THROUGH SUNDAY. EITHER WAY...GUSTY
SOUTHERLY WINDS OVER 25MPH WILL LIKELY OCCUR AHEAD OF THIS FRONT
SATURDAY INTO SUNDAY MORNING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 132 AM EDT MON AUG 17 2015
SOME -SHRA/PERHAPS A TS IN ADVANCE OF A COLD FNT APRCHG FM THE W WL
IMPACT MAINLY SAW DURING THE EARLY MRNG HRS. THE ARRIVAL OF DRIER
LLVL AIR WL ENSURE CONDITIONS REMAIN VFR AT CMX AND IWD EVEN IF SOME
-SHRA FALL THERE. BUT SAW COULD PICK UP MVFR CONDITIONS WITH MORE
HUMID LLVL AIR LINGERING. SINCE THE COLD FNT WL STALL JUST TO THE S
ON MON...AN UPPER DISTURBANCE TRACKING ALONG THIS BNDRY WL BRING A
CONTINUED CHC OF MORE -SHRA INTO THE AFTN AT SAW. WITH A WSHFT TO
AN UPSLOPE NNE DIRECTIN IN THE AFTN AND MORE LINGERING MSTR...MVFR
CIGS ARE LIKELY AT SAW FOR A TIME. SINCE CMX AND IWD WL BE FARTHER
FM THE FNT AND DEEPER INTO THE INCOMING DRY AIRMASS...VFR CONDITIONS
WL REMAIN THE RULE THERE THRU THE TAF PERIOD..
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 235 PM EDT SUN AUG 16 2015
SOUTHWEST WINDS TO 20-25 KNOTS TODAY WILL DIMINISH AND VEER NW
TONIGHT AS A COLD FRONT MOVES THROUGH. PATCHY FOG WILL CONTINUE TO
BE POSSIBLE THROUGH TONIGHT AS HUMID AIR MOVES OVER THE COOLER
WATERS OF THE GREAT LAKES. WINDS WILL STAY AT OR BELOW 20 KNOTS
THROUGH TUE NIGHT...THEN INCREASE TO UP TO 30 KNOTS ON WED INTO THU
MORNING AS THE PRESSURE GRADIENT TIGHTENS ACROSS THE AREA WITH A
STRONGER LOW PRESSURE SYSTEM MOVING THROUGH THE REGION. COULD BE
SOME NW GALE FORCE GUSTS TO 35 KNOTS THU MORNING BEHIND THIS STRONG
LOW.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TK
AVIATION...KC
MARINE...07
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
726 PM CDT TUE AUG 18 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 258 PM CDT TUE AUG 18 2015
VERY POWERFUL LOW PRESSURE MOVING FROM SOUTHWEST MN TO THE ARROWHEAD
REGION BY WEDNESDAY EVENING. IT IS VERY RARE TO SEE SUCH A STRONG
LOW PRESSURE SYSTEM IN THE SUMMER. IN FACT IT MAY WELL RIVAL THE LOW
PRESSURE RECORD FOR MSP. THE HRRR AND HOPWRF ARE IN GOOD AGREEMENT
AND HAVE DONE WELL THE LAST FEW HOURS. RADAR AND OBS SUPPORT THE
IDEA OF LESS PRECIPITATION IN TERMS OF AMOUNTS AND LESS CHANCES FOR
THUNDER AFTER 02Z THIS EVENING ACROSS THE AREA. DRY SLOT REALLY TOOK
OVER FOR THIS EVENT IN SRN MN. EXPECT THE COMMA HEAD WRAP-AROUND
PRECIPITATION TO AFFECT WESTERN MN LATE THIS AFTERNOON AND SLOWLY
LIFT EAST AND NORTH THROUGH THE EVENING AND OVERNIGHT HOURS. MAIN
PRECIPITATION WILL BE OVER WRN MN AND EXTENDING TO THE ARROWHEAD. WE
CAN EXPECT SCATTERED RAIN AND AN ISOLATED SHOWER OVER CENTRAL MN
INTO WRN WI THROUGH THE OVERNIGHT HOURS...MAYBE DRIZZLE. RAIN SHOULD
DIMINSH TOWARD MORNING AND THEN SEE AN INCREASE BY MID DAY. STRONG
WINDS WILL MOVE IN OVERNIGHT WITH GUSTS INTO THE MID 30 MPH RANGE
WEDNESDAY AFTERNOON WITH MOSTLY CLOUDY SKIES AND COOL TEMPERATURES.
VERY MUCH LIKE OCTOBER.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 258 PM CDT TUE AUG 18 2015
PICKING UP THE FORECAST WEDNESDAY NIGHT...THE FOCUS REMAINS GETTING
THIS INCREDIBLY STRONG MID AUGUST SYNOPTIC SCALE STORM SYSTEM OUT OF
HERE. BY THIS POINT...THE SURFACE LOW SHOULD BE POSITIONED OVER
WESTERN LAKE SUPERIOR AND SLIDING NORTHEAST. IT WILL BE ESSENTIALLY
VERTICALLY STACKED AND BEGIN WEAKENING OVERNIGHT. THE HIGHLY
AMPLIFIED 500MB TROUGH WILL INTRODUCE DRY NORTHWESTERLY FLOW INTO
WESTERN MN WHICH WILL EXPAND EASTWARD BY THURSDAY MORNING. DRY AIR
WILL ACCOMPANY THE NORTHWESTERLY FLOW...SO WE`LL SEE THE CLOUDS
BEGIN TO CLEAR FROM WEST TO EAST OVERNIGHT IN WESTERN MN...THROUGH
WESTERN WI BY MIDDAY THURSDAY. WITH CLEARING SKIES...AND THE LOW
MOVING OFF...WE`LL SEE TEMPERATURES REBOUND INTO THE MID 70S FOR
HIGHS. WESTERLY WINDS AT THE SURFACE OF 10-15 MPH ARE EXPECTED
THURSDAY...SO MUCH LESS WINDY THAN WEDNESDAY.
BY FRIDAY...A LOW PRESSURE SYSTEM WILL BE DEVELOPING NEAR
MONTANA...AND WE WILL BE ON THE BACK SIDE OF THE SURFACE RIDGE AXIS
ASSOCIATED WITH A SURFACE HIGH SLIDING EAST FROM THE CENTRAL PLAINS
TOWARD THE OHIO RIVER VALLEY....WHICH MEANS AN INCREASE IN SOUTHERLY
WINDS IS EXPECTED. WIND SPEEDS ARE FORECAST TO BE AROUND 15-20 MPH
WITH GUSTS OVER 20...AND TEMEPRATURES WILL WARM INTO THE LOW 80S
ONCE AGAIN. MAYBE MORE NOTICEABLY...WILL BE THE DEW POINTS RISING
INTO THE MID 60S BY FRIDAY AFTERNOON.
FOR THE WEEKEND...THE AFOREMENTIONED SYSTEM IN MONTANA WILL BE THE
FEATURE OF CONCERN. THE SURFACE LOW IS EXPECTED TO PROGRESS
EASTWARD ALONG THE INTERNATIONAL BORDER SATURDAY THROUGH
SUNDAY...BUT A NORTH-SOUTH ORIENTED COLD FRONT WILL BE THE FOCUS FOR
SHOWER AND THUNDERSTORM ACTIVITY TO DEVELOP IN OUR AREA...MOST
LIKELY SATURDAY AFTERNOON THROUGH THE OVERNIGHT HOURS. THIS SHOULD
BE A PROGRESSIVE LINE OF THUNDERSTORMS ALONG THE BOUNDARY...SO BY
SUNDAY MORNING WE SHOULD BE BACK IN DRIER NORTHWESTERLY FLOW AND
COOLER TEMEPRATURES. WILL HAVE TO SEE HOW THIS SYSTEM DEVELOPS IN
THE FUTURE MODEL GUIDANCE AS TIMING ISSUES ARE QUITE COMMON THIS FAR
OUT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 726 PM CDT TUE AUG 18 2015
CONDITIONS RANGE FROM VFR ACROSS MOST OF SOUTHERN MN TO IFR ACROSS
CENTRAL MN AND WESTERN WI. NOT ANTICIPTATING MUCH CHANGING THIS
EVENING EXCEPT IN AREAS BORDERING THE VFR/IFR REGIONS.
INCLUDING MSP/RWF/RNH/EAU...THERE MAY BE FLUCTUATIONS IN
CONDITIONS. SHOWERS WILL PERIODICALLY DEVELOP AND SHIFT NORTH
THROUGH TONIGHT. LOCALLY HEAVY RAIN AND IFR VISIBILITIES MAY
ACCOMPANY THESE SHOWERS.
KMSP...CONDITIONS ARE VARYING BETWEEN IFR AND MVFR EARLY THIS
EVENING...BUT THINK IFR CONDITIONS WILL EVENTUALLY TAKE HOLD FOR
THE OVERNIGHT. A FEW SHOWERS ARE POSSIBLE...BUT THINK THE STEADY
RAIN IS OVER.
/OUTLOOK FOR KMSP/
THU...VFR. WINDS W 10-15 KTS.
FRI...VFR. WINDS S 10-15 KTS.
SAT...VFR WITH MVFR/TSRA POSSIBLE LATE. WIND S AT 15G20 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...DRL
LONG TERM...SPD
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION
NWS DULUTH MN
413 AM CDT MON AUG 17 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 332 AM CDT MON AUG 17 2015
IN THE UPPER LEVELS A BROAD TROF OF LOW PRESSURE STRETCHES ACROSS
MUCH OF THE THE WRN 1/2 OF THE COUNTRY. IT`S THIS TROF AND
EMBEDDED SHORT WAVES THAT WILL BRING RAIN TO THE NORTHLAND THIS
WEEK.
BUT FIRST...CLOUDS AND MOISTURE WERE STILL STREAMING INTO THE
FAR EASTERN SECTION OF THE WI FORECAST AREA...MAINLY PRICE
COUNTY. THE LOLVL JET OF 40 KTS CONTINUED ALONG A COLD FRONT THAT
WENT THROUGH MOST OF THE AREA YESTERDAY...AND IS HELPING TO
GENERATE A FEW REMAINING SHOWERS IN THE AREA. THE FRONT SHOULD BE
MOVING OUT LATER THIS MORNING. IN THE MEANTIME...HIGH PRESSURE
BUILDING INTO THE REGION WILL BRING SUNSHINE TO MN ...AND GRADUAL
SUNSHINE TO NORTHWEST WI TODAY. DRIER AND COOLER TEMPERATURES CAN
BE EXPECTED AS DEW POINTS DROP INTO THE 40S IN MN AND THE 50S IN
WI.
LOOKING AHEAD....A SHORTWAVE WILL DIG INTO THE LONG WAVE TROF
TODAY...RESULTING IN SFC LOW PRESSURE TO FORM IN THE CENTRAL
ROCKIES. THIS LOW PRESSURE SYSTEM WILL MOVE NORTHEAST INTO THE
REGION TUESDAY. BY TUESDAY AFTERNOON THE SFC SYSTEM WILL BE
SOMEWHERE IN THE IOWA/NEBRASKA REGION...WITH A STRONG BAROCLINIC
ZONE ACROSS SRN MN/CENTRAL WI. INTENSE MOISTURE TRANSPORT ACROSS
THIS WILL PUT NRN WI AT BEST RISK FOR RAIN AND STORMS. STRONG EAST
WINDS WILL ALSO DEVELOP THE OF THE LOWS ADVANCE. AS THE LOW NEARS
SRN MN TUESDAY AFTERNOON...THE CHANCE OF RAIN WILL INCREASE NWRD.
THE MODELS ARE IN GOOD AGREEMENT WITH THE OVERALL CONCEPT OF THIS
FALL-LIKE WEATHER SYSTEM. BUT THERE ARE SOME MINOR DIFFERENCES IN
SPREAD AND EVENTUAL TRACK THAT COULD BE RECONCILED WITH TIME.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 332 AM CDT MON AUG 17 2015
A DEEP SFC LOW PRESSURE SYSTEM WILL BE LIFTING NEWD FROM THE TWIN
CITIES INTO NRN WI AND WRN LAKE SUPERIOR TUESDAY NIGHT AND WEDNESDAY
BRINGING WIDESPREAD RAIN WITH EMBEDDED THUNDERSTORMS TO THE ENTIRE
FORECAST AREA. THE DOMINANT FORCING WITH THIS SYSTEM IS EXPECTED TO
BE ON THE SYNOPTIC AND MESO-ALPHA SCALES ASSOCIATED WITH THE
DEEPENING UPPER TROUGH AND STRENGTHENING SFC LOW. MODEST WAA AHEAD
OF THE LOW WILL TIGHTEN THE THERMAL GRADIENT ALONG THE ELEVATED WARM
FRONT EXTENDING TO THE E/NE INTO CENTRAL WI AND PRODUCE A STRONG
LAYER OF MID-LEVEL F-GEN THAT WILL LIFT NWD ACROSS THE NORTHLAND AND
ENHANCE THE PRECIPITATION EFFICIENCY. A STRONG AREA OF Q-VECTOR
CONVERGENCE ALIGNED WITH STEEP MID-LEVEL LAPSE RATES WILL MOVE
ACROSS THE REGION AND AID IN THE STRENGTHENING OF THE LOW AND
SUPPLEMENT THE LARGE-SCALE LIFT TO PRODUCE HEAVY RAIN THROUGH THE
AREA. DEEP LAYER MOISTURE WILL INCREASE AS THE SYSTEM DEVELOPS WITH
PWATS FORECAST 1-1.5 INCHES. THE OTHER NOTABLE FEATURE WITH THIS
SYSTEM WILL BE THE STRONG E/NE WINDS OFF LAKE SUPERIOR. EXPECTING
SUSTAINED NE WINDS TUE NIGHT AND WED AROUND 20 TO 25 MPH AND GUSTS
30 TO 35 MPH.
THIS IMPRESSIVE LOW PRESSURE SYSTEM WILL FINALLY LIFT OUT OF THE
AREA THURSDAY MORNING...BUT NOT BEFORE LINGERING RAIN SHOWERS AND A
FEW POST-FRONTAL THUNDERSTORMS TRIGGER OFF THE CAA ON THE BACK SIDE
OF THE LOW OVER THE ARROWHEAD THUR AFTERNOON. WILL SEE CONDITIONS
BEGIN TO REALLY DRY OUT OVER THE ENTIRE REGION LATE THURSDAY AS HIGH
PRESSURE BUILDS IN FROM THE WEST. THE RIDGE FLATTENS OUT ON FRIDAY
BUT CONDITIONS SHOULD REMAIN QUIET UNTIL THE NEXT DEEP TROUGH DIGS
THROUGH THE CENTRAL CONUS THIS WEEKEND. THERE ARE STILL QUITE A FEW
DIFFERENCES IN THE TIMING AND STRENGTH OF THIS NEXT WAVE...BUT THE
GENERAL MODEL CONSENSUS IS FOR ANOTHER ROUND OF WIDESPREAD RAIN AND
SCATTERED THUNDERSTORMS SAT AND SUNDAY.
THE STRONG NE WINDS OFF LAKE SUPERIOR WILL PRODUCE MUCH COLDER
TEMPERATURES NEAR AND INLAND FROM THE LAKE ON WEDNESDAY. TEMPS ON
WED WILL ONLY REACH INTO THE UPPER 50S AND LOWER 60S. THE COLDEST
NIGHT WILL BE WED NIGHT/THUR MORNING AS THE SYSTEM EXITS TO THE NE
AND WINDS SHIFT TO THE NW. EXPECT WIDESPREAD 40S ACROSS THE
NORTHLAND THURSDAY MORNING WITH A FEW UPPER 30S NOT OUT OF THE
QUESTION. A GRADUAL WARMING TREND WILL START ON THURSDAY WITH TEMPS
BACK INTO THE 70S AND LOWER 80S BY SATURDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 100 AM CDT MON AUG 17 2015
A COLD FRONT HAS NEARLY EXITED THE FORECAST AREA...AND WILL DO SO
EARLY IN THE FORECAST CYCLE. BEHIND THE FRONT A SUBTLE SHORTWAVE
WILL LIFT FROM EASTERN NORTH DAKOTA INTO SOUTHERN ONTARIO. THE
SHORTWAVE HAS GENERATED LIGHT SHOWERS...WHICH WILL MOVE EASTWARDS
PER THE LATEST RADAR TRENDS AND HRRR OUTPUT. KEPT KINL OUT OF
SHOWER ACTIVITY...AND ENDED PRECIPITATION BETWEEN 0730Z AND 09Z AT
THE OTHER TERMINALS. EXPECTING MVFR CONDITIONS UNTIL 14Z AT KHYR
DUE TO RECENT RAINFALL...WHICH WILL REDUCE VISBY AND KEEP CIGS AT
OR BELOW 3000 FT. OTHER TERMINALS WILL REMAIN VFR THROUGH THE
FORECAST CYCLE. WINDS WILL REMAIN LIGHT ON MONDAY AS HIGH
PRESSURE BUILDS IN ALONG THE INTERNATIONAL BORDER.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 74 53 61 53 / 0 0 40 90
INL 70 43 71 50 / 0 0 0 70
BRD 74 52 70 53 / 0 0 50 90
HYR 73 51 70 56 / 10 10 50 90
ASX 74 53 70 55 / 10 10 30 90
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
SHORT TERM...CLC
LONG TERM...TENTINGER
AVIATION...WL
AREA FORECAST DISCUSSION
NWS DULUTH MN
100 AM CDT MON AUG 17 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 306 PM CDT SUN AUG 16 2015
THE COLD FRONT WAS STUCK ALONG THE NORTH SHORE THROUGH THE TWIN
PORTS TO JUST WEST OF HINCKLEY AT 19Z. SW WINDS WERE FOUND AHEAD OF
THE FRONT WITH WEST TO NW WINDS BEHIND THE FRONT. THE GUSTY WINDS
WILL SUBSIDE NEAR SUNSET. CLOUDS COVERED THE ENTIRE REGION AS WELL.
A FEW SHOWERS HAD DRIFTED OVER NORTHERN CASS COUNTY EARLIER AS
WALKER HAD REPORTED LIGHT RAIN. NOT EXPECTING ANY MORE RAIN IN NE MN
TONIGHT. THUNDERSTORMS NEAR THE TWIN CITIES ARE EXPECTED TO EXPAND
NEWD INTO NW WI LATE THIS AFTERNOON WHERE THE AXIS OF BEST
INSTABILITY WAS FOUND AT 19Z. MUCAPE RANGED FROM 1000-2000 J/KG AND
THE MUCIN WAS WEAKENING.
EXPECT THE THUNDERSTORMS TO PERCOLATE OVER NW WI TONIGHT AND MONDAY
AS THE COLD FRONT CONTINUES TO VERY SLOWLY MOVE EWD. THE FRONT
SHOULD BE EXITING THE NORTH CENTRAL WI PORTION OF THE FORECAST AREA
IN THE AFTERNOON. ELSEWHERE...HIGH PRESSURE WILL BE BUILDING INTO
THE REGION. EXPECT THE CLOUDS TO GRADUALLY DISSIPATE TONIGHT FROM NW
TO SE...WITH THE EXCEPTION OF NW WI. CLOUDS WILL REFORM WHERE THEY
HAD DIMINISHED ON MONDAY. MAX TEMPS ON MONDAY WILL BE LOWER THAN THE
LAST FEW DAYS.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 306 PM CDT SUN AUG 16 2015
A RATHER ACTIVE LATE-SUMMER PATTERN APPEARS TO BE SETTING UP FOR
MUCH OF THE UPCOMING WEEK ACROSS THE NORTHERN TIER OF STATES INTO
THE WESTERN GREAT LAKES REGION.
MOST OF THE MEDIUM RANGE MODELS HAVE BEEN QUITE CONSISTENT IN A
STRONGLY AMPLIFYING WAVE AND DEEP-LAYER CYCLOGENESIS ACROSS THE
IOWA/MINNESOTA/WISCONSIN AREA FROM TUE NIGHT INTO WED NIGHT..AND THE
LATEST RUNS CONTINUE THIS GENERAL TREND. CONFIDENCE THUS CONTINUES
TO INCREASE THAT WE WILL LIKELY HAVE A WIDESPREAD RAIN EVENT DURING
THIS TIME PERIOD..WITH PROBABLY SOME EMBEDDED THUNDERSTORMS. THE
DEGREE OF COVERAGE OF TSTORMS..AND POTENTIAL FOR SEVERE IS STILL
HIGHLY IN QUESTION HOWEVER..DUE TO DIFFERENCES IN THE VARIOUS MODELS
HANDLING OF THE INSTABILITY FIELDS AND PATH OF THE SURFACE LOW.
REGARDLESS OF THE DETAILS..WITH SUCH A STRONGLY DEEPENING SYSTEM SO
DEEP INTO THE WARM SEASON..THIS WILL NEED TO BE MONITORED CLOSELY.
IT APPEARS THAT POTENTIAL FOR WIDESPREAD BENEFICIAL RAINS IS RATHER
HIGH.
AFTER THIS SYSTEM DEPARTS..THE THUR-FRI TIME PERIOD LOOKS TO BE
SOMEWHAT BENIGN WITH HIGH PRESSURE BRIEFLY BUILDING IN.
HOWEVER..WARM/MOIST ADVECTION IS EXPECTED TO INCREASE AGAIN FRI-SAT
TIME FRAME AS NEXT WAVE APPROACHES. WHILE IT IS STILL A LONG WAY
OFF..THE CURRENT MODEL RUNS ARE HINTING THAT A SIMILAR STRONGLY
AMPLIFYING SCENARIO COULD PLAY OUT NEXT WEEKEND..BUT PERHAPS A BIT
FARTHER TO THE WEST. NATURALLY..CONFIDENCE ON ANY DETAILS ARE LOW
THIS FAR OUT..BUT AT LEAST SOME POTENTIAL SEEMS TO EXIST FOR
SIGNIFICANT SEVERE WEATHER AND/OR HEAVY RAINFALL IF THE FARTHER WEST
SOLUTION VERIFIES AND THE INSTABILITY AND HIGH PW AXIS CAN BUILD
NORTHWARD INTO NRN MN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 100 AM CDT MON AUG 17 2015
A COLD FRONT HAS NEARLY EXITED THE FORECAST AREA...AND WILL DO SO
EARLY IN THE FORECAST CYCLE. BEHIND THE FRONT A SUBTLE SHORTWAVE
WILL LIFT FROM EASTERN NORTH DAKOTA INTO SOUTHERN ONTARIO. THE
SHORTWAVE HAS GENERATED LIGHT SHOWERS...WHICH WILL MOVE EASTWARDS
PER THE LATEST RADAR TRENDS AND HRRR OUTPUT. KEPT KINL OUT OF
SHOWER ACTIVITY...AND ENDED PRECIPITATION BETWEEN 0730Z AND 09Z AT
THE OTHER TERMINALS. EXPECTING MVFR CONDITIONS UNTIL 14Z AT KHYR
DUE TO RECENT RAINFALL...WHICH WILL REDUCE VISBY AND KEEP CIGS AT
OR BELOW 3000 FT. OTHER TERMINALS WILL REMAIN VFR THROUGH THE
FORECAST CYCLE. WINDS WILL REMAIN LIGHT ON MONDAY AS HIGH
PRESSURE BUILDS IN ALONG THE INTERNATIONAL BORDER.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 53 61 55 62 / 0 40 80 60
INL 43 71 52 67 / 0 0 40 30
BRD 52 70 53 65 / 0 50 70 40
HYR 51 70 55 63 / 10 50 80 70
ASX 53 70 56 67 / 10 30 80 70
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
SHORT TERM...GSF
LONG TERM...MILLER
AVIATION...WL
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
703 PM CDT TUE AUG 18 2015
.SHORT TERM: (THROUGH LATE TONIGHT)
ISSUED AT 355 PM CDT TUE AUG 18 2015
PREFRONTAL CONVECTION HAS BLOWN UP ABOUT AS EXPECTED THIS AFTERNOON.
SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 900 PM THIS EVENING AND
WE`VE HAD SOME SPORADIC REPORTS OF TREE LIMBS DOWN WITH THE
STRONGEST STORMS. SBCAPE IN EXCESS OF 3000 J/KG INDICATED ON SPC
MESOANALYSIS PAGE AHEAD OF THE CONVECTION WITH A VIGOROUS SHORTWAVE
MOVING INTO WESTERN MISSOURI AT THIS TIME. MASS FIELDS ON SHORT-
RANGE GUIDANCE CONTINUE TO STREAM INSTABILITY UP INTO THE REGION
THROUGH THE EVENING...AND THIS LOOKS REASONABLE GIVEN THE POSITION
OF THE SHORTWAVE AND SURFACE FRONT. HAVE TO SAY, THE HRRR DID A
PRETTY GOOD JOB WITH THE CONVECTION THIS AFTERNOON, SO THE SHORT
RANGE FORECAST FOR TONIGHT IS BIASED HEAVILY TOWARD THE HRRR.
EXPECT STORMS CURRENTLY OVER EASTERN KANSAS TO CONTINUE TO DEVELOP
AND MOVE EASTWARD TONIGHT AHEAD OF THE SHORTWAVE. THERE WILL LIKELY
BE A LUL IN THE THUNDERSTORM ACTIVITY OVER OUR CWFA AFTER 00-02Z,
BUT THE STORMS CURRENTLY IN KANSAS WILL EVENTUALLY MOVE IN AFTER 04-
05Z. ADDITIONAL DEVELOPMENT IS ALSO POSSIBLE AHEAD OF THE KANSAS
STORMS. THE COLD FRONT WILL SWEEP INTO MISSOURI OVERNIGHT AND SHOULD
BE THROUGH CENTRAL AND INTO EASTERN MISSOURI BY 12Z.
CARNEY
.LONG TERM: (WEDNESDAY THROUGH NEXT TUESDAY)
ISSUED AT 355 PM CDT TUE AUG 18 2015
MODELS CONTINUE TO SUPPORT A FAST SURFACE FRONTAL SOLUTION WHILE
MAINTAINING A SIMILAR TIMING WITH THE UPPER LEVEL PROFILE. WHILE
THERE SHOULD STILL BE A NICE SLUG OF WIDESPREAD LIFT BUILDING IN
FROM LATE WEDNESDAY MORNING THRU EARLY EVENING...THE COLUMN WILL
BE VERY LIMITED THERMODYNAMICALLY...MEANING LIKE MOSTLY SHOWERS WITH
DIMINISHING CHANCES FOR THUNDER AS THE DAY GOES ALONG. DECENT RAIN
CHANCES ARE NOW EXPECTED TO LINGER INTO EARLY EVENING BEFORE THEN
MAKING A RAPID EXIT FROM SOUTHWEST TO NORTHEAST FOLLOWED QUICKLY BY
CLEARING SKIES.
WHAT WILL REMAIN IN ITS WAKE WILL BE A RARE COOL AND DRY PERIOD
BEGINNING LATE WEDNESDAY NIGHT THRU FRIDAY AFTERNOON WITH MIN TEMPS
DIPPING INTO THE 50S AND MAX TEMPS ONLY REACHING TO AROUND 80
DEGREES.
THE FRONTAL COMPLEX THAT HAD PUSHED TO OUR SOUTH ON WEDNESDAY
WILL THEN MOVE BACK TO THE NORTH BY SATURDAY TO ALLOW CHANCES FOR
THUNDERSTORMS TO RETURN AND PERSIST THRU THE WEEKEND WITH
TEMPERATURES BACK TO SEASONABLE AVERAGES.
IN YET ANOTHER SIGN THAT AUTUMN IS NOT TOO FAR OFF ANYMORE...ANOTHER
DECENTLY STRONG COLD FRONT PUSHES THRU LATE SUNDAY AND IS
EXPECTED TO BRING AN ENCORE OF THE COOL AND DRY PERIOD FOR MONDAY
AND TUESDAY OF NEXT WEEK.
SOME MODEL DISCREPANCIES THEN EXIST HEADING DEEPER INTO NEXT WEEK
BUT THE GENERAL THEME IS SUMMER THEN REMINDING US THAT IT IS NOT YET
DONE...WITH AN UPPER LEVEL RIDGE ATTEMPTING TO BUILD IN TO POSSIBLY
DELIVER ONE FINAL ROUND OF DANGEROUS HEAT AND HUMIDITY TO CLOSE OUT
AUGUST.
TES
&&
.AVIATION: (FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 639 PM CDT TUE AUG 18 2015
PRIMARY CONCERN FOR THE NEXT 3-5 HOURS IS ONGOING CONVECTION OVER
PARTS OF EASTERN MISSOURI AND SOUTHWEST ILLINOIS. EXPECT THESE
STORMS TO CONTINUE WEAKENING AS THEY MOVE EAST THROUGH THE
EVENING. ANY STORM WILL BE CAPABLE OF REDUCING VISIBILITY TO TO 1
MILE OR LESS IN HEAVY RAIN. VFR CONDITIONS AND SCATTERED LIGHT
SHOWERS WILL PREVAIL OUTSIDE OF THUNDERSTORMS.
STORMS OVER EASTERN KANSAS WILL CONTINUE TO MOVE EASTWARD THIS
EVENING. MODEL GUIDANCE IS IN GOOD AGREEMENT THAT THE STORMS WILL
PERSIST INTO OUR AREA...MOVING INTO CENTRAL MISSOURI BY 03-05Z AND
TO THE MISSISSIPPI RIVER BY 05-06Z. THE COLD FRONT NOW OVER
EXTREME NORTHWEST MISSOURI WILL SWEEP THROUGH THE AREA BY MID
MORNING. ADDITIONAL PRECIPITATION LOOKS LIKELY BEHIND THE FRONT
DURING THE LATE MORNING AND AFTERNOON. CONFIDENCE IS LOW ON FLIGHT
CONDITIONS ON WEDNESDAY, BUT LOW TO MID RANGE MVFR LOOKS MOST
LIKELY AT THIS TIME.
SPECIFICS FOR KSTL:
VFR FLIGHT CONDITIONS ARE EXPECTED TO PREVAIL WITH A FEW LIGHT
SHOWERS IN THE AREA FOR MUCH OF THE REST OF THE EVENING. THE
STORMS CURRENTLY OVER KANSAS SHOULD REACH THE TERMINAL AROUND
MIDNIGHT...HOWEVER I`M NOT VERY CONFIDENT HOW ORGANIZED OR STRONG
THEY`LL BE. THE COLD FRONT WILL MOVE THROUGH THE TERMINAL AROUND
12Z...THINK THE MVFR CEILINGS OVER NEBRASKA AND IOWA WILL EXPAND
OVERNIGHT BEHIND THE FRONT. ADDITIONALLY, THERE WILL BE MORE
PRECIPITATION BEHIND THE FRONT LATE WEDNESDAY MORNING OR
AFTERNOON, BUT AM NOT SURE ON TIMING OR INTENSITY SO HAVE NOT
INCLUDED IT IN THE TAF AT THIS TIME.
CARNEY
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
341 PM MDT MON AUG 17 2015
.SYNOPSIS...
SEVERE THUNDERSTORMS WILL REMAIN POSSIBLE THROUGH THE EVENING
ACROSS MUCH OF NORTHEAST NEW MEXICO. LARGE HAIL AND DAMAGING WINDS
WILL BE THE MAIN THREATS. THEREAFTER...A DRYING TREND WILL
COMMENCE. MUCH FEWER STORMS ARE EXPECTED TUESDAY THROUGH THURSDAY.
A BACK DOOR FRONT ON TUESDAY NIGHT WILL RESULT IN FALL LIKE
TEMPERATURES ON WEDNESDAY ACROSS THE EASTERN PLAINS. LATER IN THE
WEEK...A SLOW INCREASE IN THUNDERSTORM ACTIVITY IS POSSIBLE.
&&
.DISCUSSION...
SEVERE WEATHER REMAINS POSSIBLE THROUGH THIS EVENING ACROSS THE
NORTHEAST QUADRANT OF NM. 35 TO 40KTS OF BULK SHEAR AND CAPE UP TO
2500 J/KG PER LAPS ANALYSIS WILL PROVIDE AN ENVIRONMENT VERY
SUITABLE FOR STORMS TO BECOME SEVERE AS THEY MOVE OFF THE HIGHER
TERRAIN INTO THE NE PLAINS. A JET MAX WILL ALSO AID IN TSTM
DEVELOPMENT AND FOCUS ACTIVITY ACROSS THE NE. LARGE HAIL AND
DAMAGING WIND GUSTS WILL BE THE MAIN THREAT WITH THIS ACTIVITY.
THE LATEST HRRR SHOWS MOST OF THIS INITIAL ROUND OF ACTIVITY
EXITING NM BY MID EVENING...BUT ANOTHER ROUND OF STORMS MAY
DEVELOP LATER THANKS TO OUTFLOW BOUNDARIES MOVING IN FROM SE CO.
THE UPPER LEVEL TROUGH WILL CROSS THE CENTRAL ROCKIES TONIGHT AND
THE ASSOCIATED PACIFIC FRONT WILL SLIDE THROUGH CENTRAL AND
WESTERN NM. MUCH DRIER AIR BEHIND THE TROUGH AND BREEZY WINDS WILL
MIX DOWN TO THE SURFACE...RESULTING IN SOME OF THE LOWEST
DEWPOINTS WE HAVE SEEN ACROSS THE NW SINCE THE SPRING.
MEANWHILE...THE BACK DOOR SEGMENT OF THE FRONT WILL SLIDE DOWN THE
PLAINS. A FEW STORMS MAY DEVELOP ALONG THE FRONT AND ALONG THE
EAST SLOPES OF THE SANGRES...BUT THE DEEP LAYER OF DRIER AIR ALOFT
WILL LIMIT COVERAGE SIGNIFICANTLY. THE FRONT SHOULD PUSH THRU THE
GAPS OF THE CENTRAL MTN CHAIN TUESDAY NIGHT...BUT THE MOISTURE IT
BRINGS WITH IT SHOULD QUICKLY MIX OUT ON WEDNESDAY WITHIN THE RGV.
ON WEDNESDAY...SOME OF THE MOISTURE ACROSS THE PLAINS WILL ALSO
MIX OUT. CONTINUE LOW LEVEL SOUTHEASTERLY FLOW...HOWEVER...MAY
YIELD A STRAY SHOWER OR TSTM ALONG THE CENTRAL MTN CHAIN...BUT
CONFIDENCE IS PRETTY LOW. THE BIGGER STORY WILL BE THE MUCH COOLER
TEMPS ACROSS THE EAST IN THE WAKE OF THE BACK DOOR FRONT. MOST
AREAS WILL STRUGGLE TO REACH 80.
ANOTHER WEAK WAVE LOOKS TO CROSS NM ON THURSDAY...BUT CONTINUED
DRY AIR OVER THE STATE WILL CONTINUE TO LIMIT TSTM ACTIVITY. SE
PORTIONS OF THE CWA MAY BE FAVORED FOR AN ISOLATED STORM WHERE
BETTER LOW LEVEL MOISTURE EXISTS.
CONFIDENCE REMAINS LOW IN THE FORECAST FRIDAY AND BEYOND. MODELS
CONTINUE TO SUGGEST SOME MOISTURE WILL SEEP UP INTO NM AND WE WILL
SEE A GRADUAL INCREASE IN TSTM ACTIVITY. OF MORE CERTAINTY LOOKS
TO BE ANOTHER BACK DOOR COLD FRONT SLIDING DOWN THE PLAINS OVER
THE WEEKEND WHICH WILL HELP TO MOISTEN UP LOW LEVELS...BUT THE
PARENT TROUGH MAY BRING DRIER AIR OVER NORTHERN NM ONCE AGAIN.
STAY TUNED.
34
&&
.FIRE WEATHER...
FAIRLY ACTIVE AND VIGOROUS BATCH OF SHOWERS AND STORMS AS OF MID
AFTN STRETCHING FROM THE SANGRE DE CRISTOS AND NE HIGHLANDS AND
PLAINS SOUTH AND SOUTHWESTWARD TO THE CENTRAL HIGHLANDS AND MID TO
LOWER RIO GRANDE VALLEY. A FEW HAVE ALREADY BECOME SEVERE ACROSS
THE NORTHERN PORTION OF THIS AREA. THIS ACTIVITY WILL EXPAND SOME
ACROSS THE EASTERN PLAINS THROUGH THE EVE. MOST OF THE NW THIRD OF
THE STATE WILL BE DRY THROUGH THE EVENING AND THIS DRYING TREND
WILL EXPAND SOUTH AND EAST OVER THE NEXT 24 TO 48 HOURS IN THE
WAKE OF A SIGNIFICANT AND EARLIER THAN USUAL MID TO UPPER LOW
PRESSURE TROUGH. ACCOMPANYING AND IN THE WAKE OF THE TROUGH WILL
BE A STRENGTHENING NORTHWEST FLOW ALOFT OVER CENTRAL AND NORTHERN
NEW MEXICO THAT WILL USHER THE MUCH DRIER AIR MASS FROM NW TO SE.
WEST AND NW NEAR SFC WINDS WILL BE PERKING UP SIGNIFICANTLY ACROSS
MUCH OF NORTHERN NM TUE IN RESPONSE TO THE INCREASED NW FLOW ALOFT.
SOME SPOTTY AND LOCALIZED CRITICAL FIRE WEATHER CONDITIONS WILL BE
POSSIBLE OVER AREAS MAINLY BETWEEN THE NW PLATEAU AND THE HIGH
TERRAIN OF RIO ARRIBA AND LOS ALAMOS COUNTIES. THESE CONDITIONS ARE
NOT EXPECTED TO BE WIDESPREAD AND GIVEN CURRENT FUEL STATUS AND
LOW/MODERATE FIRE DANGER...FIRE WEATHER HIGHLIGHTS WILL NOT BE
ISSUED. STILL MIN RH WILL REALLY CRATER OCCUR ON TUE. SURFACE DEW
POINTS WILL DROP INTO THE 20S AND 30S ACROSS THE NW THIRD TO
NEARLY HALF OF FCST AREA TUE AFTN.
DAYTIME TEMPS WILL LOWER BY 5 TO 15 DEGREES...THE MOST EAST...WED IN
WAKE OF AN ASSOCIATED PACIFIC FRONT AS WELL AS A BACKDOOR SEGMENT OF
THE FRONTAL SYSTEM. THE LATTER WILL REACH NE AREAS ON TUESDAY...WITH
THE MAIN SOUTHWARD SURGE TUE NIGHT INTO WED. THIS SHOULD BRING AT
LEAST A MODERATE EAST GAP WIND INTO PORTIONS OF THE RIO GRANDE
VALLEY AND THUS DEW POINTS WILL RECOVER EAST OF THE CENTRAL
MOUNTAIN CHAIN AND TO A LESSER DEGREE INTO THE RIO GRANDE VALLEY FOR
WED.
THE WED TO THU PERIOD SHOULD FEATURE LITTLE OR NO THUNDER IN THE
FCST AREA. EXPECT WARMING TEMPERATURES AND SLIGHT MOISTURE INCREASE
FOR LATE WEEK AS HIGH PRESSURE BUILDS AND THE AIR MASS GRADUALLY
RECOVERS. EXCELLENT VENTILATION THE NEXT 3 TO 5 DAYS...EXCEPT THE
EAST HALF ON WED MAY ONLY REACH FAIR TO GOOD LVLS.
43
&&
.AVIATION...
18Z TAF CYCLE
YET ANOTHER ROUND OF SHRA AND TSRA DEVELOPING AS OF THIS WRITING
ACROSS FAR NORTHERN NM AND THIS ACTIVITY WILL DEVELOP TO THE EAST
AND SE AS THE AFTN PROGRESSES WITH SOME ISOLATED TO SCT DEVELOPMENT
MAINLY E AND SOUTH OF A LINE FROM GRANTS TO THE NW CORNER OF
CATRON COUNTY. SOME STORMS LIKELY TO BECOME STRONG TO SEVERE
ACROSS NE AND E CENTRAL NM LATER THIS AFTN INTO THE EVE WITH A FEW
STRONG STORMS ALSO POSSIBLE REMAINDER OF N CENTRAL AND EASTERN NM.
THESE STRONGER TO SEVERE STORMS MAY PRODUCE BRIEF MVFR CIGS AND
VSBY...ALONG WITH BRIEF MT OBSCURATIONS...HAIL AND WIND GUSTS
BETWEEN 40 AND 55 KTS. DRIER ACROSS ROUGHLY NW THIRD OF NM WITH
ONLY ISOLATED -TSRA COVERAGE. TSRA INTENSITY AND COVERAGE TO
DIMINISH SOME LATE TONIGHT.
43
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 60 92 53 89 / 5 0 5 0
DULCE........................... 50 86 45 82 / 10 10 5 0
CUBA............................ 54 84 52 76 / 10 5 5 0
GALLUP.......................... 54 91 51 88 / 0 0 5 0
EL MORRO........................ 53 86 50 84 / 5 0 5 0
GRANTS.......................... 55 89 51 86 / 0 0 5 0
QUEMADO......................... 56 87 52 85 / 5 5 5 0
GLENWOOD........................ 59 89 56 89 / 10 5 10 0
CHAMA........................... 46 79 43 76 / 10 10 5 0
LOS ALAMOS...................... 60 86 56 78 / 10 5 5 0
PECOS........................... 56 84 54 74 / 30 10 10 10
CERRO/QUESTA.................... 53 78 48 75 / 20 20 10 0
RED RIVER....................... 45 73 43 67 / 30 30 20 10
ANGEL FIRE...................... 47 73 43 66 / 40 30 20 10
TAOS............................ 50 82 49 75 / 10 20 10 0
MORA............................ 54 79 51 71 / 40 20 20 10
ESPANOLA........................ 58 90 56 83 / 10 10 5 0
SANTA FE........................ 61 86 57 80 / 20 10 5 5
SANTA FE AIRPORT................ 59 91 58 83 / 10 5 5 0
ALBUQUERQUE FOOTHILLS........... 66 93 61 86 / 5 0 5 0
ALBUQUERQUE HEIGHTS............. 68 96 64 88 / 0 0 5 0
ALBUQUERQUE VALLEY.............. 65 97 61 90 / 0 0 5 0
ALBUQUERQUE WEST MESA........... 66 96 63 89 / 0 0 5 0
LOS LUNAS....................... 64 97 61 90 / 5 0 5 0
RIO RANCHO...................... 66 97 62 89 / 5 0 5 0
SOCORRO......................... 67 100 64 97 / 5 0 5 0
SANDIA PARK/CEDAR CREST......... 59 89 57 80 / 10 0 5 10
TIJERAS......................... 60 91 56 84 / 10 0 5 0
MORIARTY/ESTANCIA............... 55 91 53 84 / 10 5 5 5
CLINES CORNERS.................. 59 87 54 77 / 20 10 10 10
GRAN QUIVIRA.................... 61 90 57 85 / 10 0 5 5
CARRIZOZO....................... 64 95 62 89 / 10 5 10 5
RUIDOSO......................... 61 83 57 77 / 30 10 20 20
CAPULIN......................... 57 78 51 72 / 70 20 30 5
RATON........................... 55 82 52 74 / 50 30 30 5
SPRINGER........................ 57 85 55 73 / 50 30 30 5
LAS VEGAS....................... 56 86 52 73 / 40 30 20 10
CLAYTON......................... 62 82 53 73 / 60 20 20 5
ROY............................. 60 82 55 69 / 60 30 20 5
CONCHAS......................... 66 91 59 74 / 60 20 20 5
SANTA ROSA...................... 64 94 59 78 / 50 20 20 5
TUCUMCARI....................... 66 91 60 77 / 60 20 20 5
CLOVIS.......................... 64 92 60 77 / 30 30 30 5
PORTALES........................ 65 93 60 77 / 30 30 30 5
FORT SUMNER..................... 67 95 62 75 / 40 20 20 5
ROSWELL......................... 69 101 66 84 / 20 10 20 5
PICACHO......................... 65 96 62 83 / 30 10 20 10
ELK............................. 63 89 61 78 / 30 10 20 20
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
34
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1135 PM MDT SUN AUG 16 2015
.AVIATION...
06Z TAF CYCLE
THUNDERSTORM ACTIVITY HAS LARGELY DIMINISHED...HOWEVER A FEW
STRAY STORMS ARE CURRENTLY WORKING INTO THE EAST CENTRAL PLAINS OF
NEW MEXICO WITH ONLY SHOWERS STRUGGLING TO HOLD FARTHER NORTHEAST
AT THE MOMENT. GUSTY DOWNBURST WINDS...SMALL HAIL...AND HEAVY
DOWNPOURS WILL ACCOMPANY THUNDERSTORMS WITH NEW DEVELOPMENTEXPECTED
POSSIBLE INTO THE NORTHEAST PLAINS OVERNIGHT. THE BULK OF THE
ACTIVITY WILL LIKELY DIMINISH BEFORE 17/1000UTC...BUT A FEW CELLS
COULD SUSTAIN THEREAFTER. STORMS ON MONDAY WILL STRETCH FROM THE
SOUTH CENTRAL PARTS OF NEW MEXICO TO THE NORTHEAST CORNER WITH A
FEW STORMS BECOMING SEVERE IN THE NORTHEAST LATE IN THE AFTERNOON.
52
&&
.PREV DISCUSSION...306 PM MDT SUN AUG 16 2015...
.SYNOPSIS...
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS IS EXPECTED FOR THE
EASTERN PLAINS TONIGHT AS STORMS THIS AFTERNOON ROLL OFF THE
CENTRAL MOUNTAIN CHAIN. ON MONDAY AND TUESDAY...A BETTER CHANCE OF
SEVERE WEATHER EXISTS ACROSS NORTHEAST NEW MEXICO WHERE LARGE HAIL
AND DAMAGING WINDS WILL BE POSSIBLE. MEANWHILE...DRIER CONDITIONS
WILL PREVAIL ACROSS THE WEST. A COLD FRONT THAT RACES THROUGH THE
PLAINS TUESDAY WILL BE RESPONSIBLE FOR MUCH COOLER TEMPERATURES
ACROSS THE EAST ON WEDNESDAY...WITH MANY LOCALES STRUGGLING TO
REACH 80. DRIER WEATHER IS IN STORE AREA WIDE FOR WEDNESDAY AND
THURSDAY.
&&
.DISCUSSION...
CONVECTION IS NOT QUITE AS ROBUST TODAY AS IT WAS YDAY AT THIS
TIME. THIS MAY BE OWING TO A COOLER START DUE TO REMNANT CLOUD
COVER THIS MORNING...AND PERHAPS MORESO...THERE IS SOME EVIDENCE
ON WV SATELLITE OF DRIER AIR MOVING IN FROM THE WEST. REMNANT
MOISTURE PLUME LOOKS TO BE STRETCHING ACROSS THE EAST...AND
ALONG/EAST OF THE CENTRAL MTN CHAIN WILL BE THE FAVORED AREA FOR
STORMS THROUGH TONIGHT. SIMILAR TO YESTERDAY...THE HRRR SHOWS A
CLUSTER OF STORMS ACROSS THE PLAINS LATE THIS EVENING. A FEW
STORMS MAY BE STRONG OR SEVERE...OR MAY CREATE LOCALIZED FLOODING
ISSUES. HAVE INCREASED POPS ACCORDINGLY ONCE AGAIN.
MONDAY LOOKS TO BE A BIT MORE FAVORED FOR SEVERE WX ACROSS THE
NORTHEAST AS THE NOSE OF AN UPPER LEVEL JET PUSHES INTO COLORADO
AND NORTHERN NM...INCREASING SHEAR. SHOULD STILL BE PLENTY OF LOW
LEVEL MOISTURE AROUND...AND CAPE VALUES SHOULD BE SIMILAR TO THIS
AFTN...BETWEEN 1000-1500 J/KG. THUS...THE ADDED SHEAR WILL BE THE
MAIN FACTOR INCREASING SEVERE CHANCES. LARGE HAIL AND DAMAGING
WIND GUSTS WILL BE THE MAIN THREATS. FURTHER SOUTH ACROSS THE
PLAINS...STORM COVERAGE WILL BE MUCH LESS...BUT COULD STILL SEE A
STRONG STORM OR TWO DEVELOP.
THE UPPER LEVEL TROUGH THAT WE HAVE BEEN ADVERTISING WILL CROSS
THE CENTRAL ROCKIES MONDAY NIGHT AND EARLY TUESDAY...WITH AN
ASSOCIATED PACIFIC FRONT SLIDING FROM NW TO SE ACROSS NM. FOR A
CHANGE..IT WILL ACTUALLY BE BREEZY TO WINDY ACROSS MUCH OF NW NM.
STRUGGLED WITH WHAT TO DO WITH HIGH TEMPS ACROSS THE CENTRAL AND
WEST. THE DRIER AIR WOULD SUGGEST WARMER...BUT LOWER
HEIGHTS/COOLER 700MB TEMPS WOULD SUGGEST COOLER. LATER ON TUESDAY
MORNING THRU TUESDAY AFTN...THE MORE SUBSTANTIAL BACK DOOR FRONT
WILL SLIDE DOWN THE PLAINS AND MODELS ARE NOW ADVERTISING IT WILL
PUSH THRU THE GAPS OF THE CENTRAL MTN CHAIN TUESDAY NIGHT. LOW
LEVEL MOISTURE WILL BE REPLENISHED BEHIND THE BACK DOOR
FRONT...AFTER IT WAS SCOURED OUT BY THE PACIFIC FRONT. UPSLOPE
FLOW AND CONTINUED INSTABILITY SHOULD YIELD SCATTERED STORMS
ACROSS AT LEAST THE NE. ONCE AGAIN...A FEW STORMS MAY BE STRONG OR
SEVERE.
AFTER THE TROUGH PASSAGE...MUCH DRIER MID LEVEL AIR WILL BE IN
PLACE ACROSS THE LAND OF ENCHANTMENT...SIGNIFICANTLY LIMITING
PRECIP CHANCES FOR WEDNESDAY. ANY STORM WILL BE HARD TO COME
BY...DESPITE THE LOW LEVEL MOISTURE NOT ENTIRELY MIXING OUT ACROSS
THE PLAINS. ADDITIONALLY...IT WILL BE SIGNIFICANTLY COOLER ACROSS
THE EAST ON WEDNESDAY BEHIND THE FRONT WITH MANY AREAS STRUGGLING
TO REACH 80F. THE DRY WX WILL CONTINUE ON THURSDAY...THEN MODELS
CONTINUE TO STRUGGLE WITH THE UPPER AIR PATTERN. THE EC SHOWS
ANOTHER STRONG TROUGH ACROSS THE CENTRAL ROCKIES ON
SATURDAY...WITH DRIER AIR CONTINUING TO FILTER INTO NM. THE GFS
HAS THIS TROUGH MUCH FURTHER NORTH WITH THE UPPER HIGH TRYING TO
REBUILD OVER THE SW CONUS...PERHAPS ALLOWING FOR SOME MOISTURE
SEEPAGE. BEHIND THIS AFOREMENTIONED TROUGH...ANOTHER BACK DOOR
FRONT SHOULD REPLENISH LOW LEVEL MOISTURE ACROSS THE PLAINS SAT
NIGHT/SUN. BUT WITHOUT A S OR SWLY FLOW ALOFT...THINK THE GFS IS
OVERDOING THE MOISTURE FLUX/QPF IN THE EXTENDED...AT LEAST THURS
NIGHT-SAT. STAY TUNED.
34
&&
.FIRE WEATHER...
UPPER HIGH CENTER HAS DRIFTED FARTHER WEST INTO ARIZONA AND
CIRCULATION ATTEMPTING TO PUSH SOME DRIER MID LEVEL AIR INTO THE
FOUR CORNERS REGION. THE DRYING TREND OVER WESTERN AND CENTRAL NM
BECOMES MORE PRONOUNCED BY MID TO LATE WEEK AS A DISTURBANCE SWEEPS
OUT OF THE NORTHERN ROCKIES AND NORTHWEST FLOW PREDOMINATES OVER NM.
VERY SPOTTY CRITICAL CONDITIONS POSSIBLE FROM THE NORTHWEST PLATEAU
TO THE CENTRAL HIGHLANDS TUESDAY AFTERNOON.
A SURFACE FRONT TUESDAY NIGHT WILL PUSH HIGHER DEW POINTS INTO THE
RGV BUT THEY SHOULD MIX OUT WEDNESDAY. ANOTHER FRONT LATE IN THE
WEEK OR OVER THE WEEKEND COULD REPLENISH LOW LEVEL MOISTURE CENTRAL
AND EAST...BUT BY THEN...A SPRAWLING RIDGE ALOFT COULD STEER THE
MAJORITY OF MONSOON MOISTURE AWAY FROM NM.
CONVECTION ALREADY GOING BY MIDDAY OVER THE NORTHERN AND WESTERN
HIGH TERRAIN. CELL MOTION TO THE SOUTH AND SOUTHWEST...WITH SHORT
TERM MODELS INDICATING THE EASTERN PLAINS WILL SEE RAIN THIS EVENING
AND OVERNIGHT...AFTER STORMS GET GOING OVER SE CO. POTENTIAL FOR
ISOLD STRONG TO SEVERE STORMS NE. ALSO LOOKING FOR A CONVECTIVELY
DRIVEN EAST WIND INTO THE RGV TONIGHT. MONDAY INTO TUESDAY WILL SEE
POTENTIAL FOR ISOLATED STRONG TO SEVERE STORMS FROM THE CENTRAL MT
CHAIN EASTWARD. THE BATTLE OF THE DRY IN THE WEST AND THE WET IN THE
EAST BECOMES SHARPER TUESDAY...WITH ONLY ISOLATED CONVECTION
FORECAST WEST. HIGH HAINES FORECAST TO BE WIDESPREAD OVER THE
CENTRAL AND WEST TUESDAY...AND OVER NEARLY ALL OF THE FORECAST AREA
THURSDAY AND FRIDAY. OVERALL...OVERNIGHT RH TRENDS WILL BE LESS
GENEROUS WEST AND CENTRAL AS THE WORK WEEK PROGRESSES...AND AFTERNOON
MIN RH VALUES WILL DECREASE AS WELL. HIGHS WILL GENERALLY BE NEAR TO
ABOVE AVERAGE...EXCEPT IN THE EAST WEDNESDAY IN THE WAKE OF
TUESDAY/S FRONT.
CONVECTION TAPERS OFF WEDNESDAY/THURSDAY WITH A FEW MOSTLY DIURNAL
STORMS OVER THE HIGHER TERRAIN...BUT SLOWLY INCREASES IN AREAL
COVERAGE INTO THE WEEKEND.
ECMWF A LITTLE SLOWER THAN GFS DEVELOPING THE MASSIVE RIDGE ALOFT
EARLY NEXT WEEK...BY 240 HRS IT HAS A MUCH STRONGER TROF OVER THE
NRN ROCKIES AND POSSIBLY A BETTER FETCH OF MOISTURE INTO NM FROM OLD
MEXICO. SO INCREASING UNCERTAINTY IN THE FORECAST WITH TIME.
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1117 PM EDT TUE AUG 18 2015
.SYNOPSIS...
UNSETTLED WEATHER WILL CONTINUE THROUGH MID WEEK AS MOISTURE
STREAMS INTO THE AREA AHEAD OF AN APPROACHING COLD FRONT. THE
COLD FRONT WILL REACH THE COASTAL CAROLINAS BY FRIDAY AND SHOULD
MAKE IT JUST SOUTH AND EAST BEFORE WASHING OUT DURING THE WEEKEND.
ANOTHER COLD FRONT IS EXPECTED TO REACH THE AREA TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 1100 PM TUESDAY...ONE AREA OF SHOWERS WAS BRUSHING MARLBORO
AND ROBESON COUNTIES. OTHER SLOW MOVING SHOWERS AND THUNDERSTORMS
WERE MOVING ACROSS CENTRAL PORTIONS OF THE CAROLINAS. THIS
ACTIVITY WAS AHEAD OF A MID LEVEL SHORTWAVE WHICH WILL BE MOVING
ACROSS THE AREA OVERNIGHT.
WE DO EXPECT MAINLY ISOLATED THUNDERSTORMS AND SHOWERS TO PERSIST
AS THEY MOVE INTO WESTERN PORTIONS OF THE FORECAST AREA
OVERNIGHT. HOWEVER...THE HIGH RESOLUTION HRRR CONTINUES TO SHOW
THIS ACTIVITY WANING WITH TIME WHILE CONVECTION EVENTUALLY
BLOSSOMS ACROSS THE WATERS. THIS IS SIMILAR TO WHAT TRANSPIRED
LAST NIGHT. WILL SHOW LOW POPS...SMALL CHANCE/SLIGHT CHANCE FOR
THE REMAINDER OF THE NIGHT. HOWEVER... WILL TREND POPS HIGHER NEAR
THE IMMEDIATE COAST AS THE FLOW SHOULD ALLOW SOME OF THE LATE
NIGHT OCEAN SHOWERS AND THUNDERSTORMS TO BRUSH THE MORE IMMEDIATE
COAST.
STRATUS WAS BEGINNING TO EXPAND ACROSS THE EASTERN CAROLINAS LATE
THIS EVE. I HAVE INCLUDED PATCHY FOG FOR A GOOD PORTION OF THE
AREA. INLAND AREAS ARE FAVORED OVER THE MORE IMMEDIATE COAST DUE
TO THE MORE SIGNIFICANT RAINFALL THERE TODAY. ALTHOUGH A
DEVELOPING NOCTURNAL JET MAY FAVOR LOW STRATUS OVER FOG...THE
20-30 KT WINDS ABOVE THE BOUNDARY LAYER SHOULD BE RATHER SHORT-
LIVED.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...MID TO UPPER LEVEL RIDGE ALIGNED UP THE
SOUTHEAST COAST SANDWICHED BETWEEN UPPER LOW WELL OFF SHORE AND
TROUGH EXTENDING DOWN FROM THE GREAT LAKES WELL WEST OF OUR AREA.
THIS MID TO UPPER TROUGH WILL PUSH A COLD FRONT EAST INTO THE
CAROLINAS BEFORE IT LIFTS OFF TO THE NORTHEAST INTO CANADA BY
THURS NIGHT. PLENTY OF DEEP MOISTURE WILL STREAM INTO THE AREA
AHEAD OF THIS SYSTEM AND WILL COMBINE WITH MINOR SHORTWAVE ENERGY
AND LOCALIZED CONVERGENCE ALONG PIEDMONT TROUGH...SEA BREEZE AND
THE COLD FRONT UPSTREAM TO PRODUCE GREATER COVERAGE OF CLOUDS AND
CONVECTION THROUGH MID WEEK. LOCAL AREA WILL REMAIN ON THE TOP OF
THE RIDGE WITH A FLATTER W-SW FLOW ALOFT WHICH WILL AID IN
ADVECTING PLENTY OF DEBRIS CLOUDS AND STEERING CONVECTION TOWARD
THE LOCAL FORECAST AREA. MOISTURE PROFILES SHOW THE BRUNT OF THIS
MOISTURE IN THE MID TO UPPER LEVELS AS PLENTY OF MID TO HIGH LEVEL
DEBRIS CLOUDS STREAM INTO AREA. PCP WATER VALUES REMAIN ABOVE 2
INCHES THROUGH THE PERIOD. BY LATE THURS THE COLD FRONT SHOULD
DROP FAR ENOUGH SOUTH INTO THE COASTAL CAROLINAS BUT IT SHOULD
BEGIN TO LAY DOWN AND SLOW DOWN OUT AS THE UPPER FLOW FLATTENS
FURTHER AS MID TO UPPER TROUGH LIFTS OFF INTO CANADA. SOUTHERLY
SFC WINDS WILL BEGIN TO VEER AROUND TO THE WEST BY THURS. THIS
WILL PRODUCE A DEEPER DOWNSLOPE FLOW AND WILL HELP TO BREAK UP THE
CLOUDS AND PRODUCE WARMER TEMPS. BUT IT WILL ALSO ENHANCE LIFT AND
POTENTIAL FOR THUNDERSTORMS ACROSS THE AREA...ESPECIALLY CLOSER TO
THE COAST. EXPECT TEMPS TO REACH UP INTO THE MID TO UPPER 80S ON
WED AND INTO THE 90S MOST PLACES ON THURS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 300 PM TUESDAY...A SLOW MOVING COLD FRONT LOOKS TO PUSH
THROUGH ON FRIDAY. WITH MID LEVEL RIDGING AHEAD OF THIS FEATURE
AND FAIRLY WEAK LOW LEVEL MOISTURE FLUX IT DOESN`T APPEAR THAT
THERE WILL BE MUCH RAIN QUANTITATIVELY EVEN THOUGH FORECAST
RAINFALL CHANCES MAY BE HIGHER THAN CLIMATOLOGY. THIS BOUNDARY
APPEARS TO STALL CLOSE ENOUGH TO THE COAST FOR SOME SMALL RAIN
CHANCES MAINLY ALONG THE BEACHES. SUNDAY AND MONDAY WILL BRING THE
LOWEST RAIN CHANCES OF THE PERIOD BUT WITH A LITTLE BIT OF
LINGERING LOW LEVEL MOISTURE ITS TOUGH TO GO WITH A COMPLETELY DRY
FORECAST. THEY SHOULD RAMP UP AGAIN ON TUESDAY WITH THE APPROACH
OF ANOTHER COLD FRONT. THIS NEXT FRONT MAY ALSO LACK MUCH IN THE
WAY OF MOISTURE FLUX BUT MAY HAVE BETTER UPPER LEVEL SUPPORT FOR
PRECIP GENERATION.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
AS OF 00Z...CONVECTION IS WINDING DOWN...BECOMING SOME WEAK
STRATIFORM PRECIPITATION. VFR CONDITIONS ARE EXPECTED FOR THE MOST
PART...WITH PATCHES OF LIGHT RAIN EXPECTED THROUGH THE EVENING
HOURS. CONVECTIVE DEBRIS WILL KEEP CEILINGS IN THE MID CLOUD
RANGE...WITH LITTLE FOG EXPECTED DUE TO THE INSOLATION FROM THE
CLOUDS. TIME HEIGHT INDICATES A SLIGHT BREAK IN THE DEEP MOISTURE
THROUGH THE OVERNIGHT HOURS...WITH A REEMERGENCE DURING THE DAY
WEDNESDAY. IF WE MANAGE TO GET SOME SOLAR INSOLATION DURING THE
DAY TOMORROW...CONVECTION COULD BE STRONGER THAN TODAY WITH MORE
COVERAGE.
EXTENDED OUTLOOK...SCATTERED CONVECTION IS EXPECTED THROUGH THE
PERIOD...MOST ACTIVE WEDNESDAY AND THURSDAY WITH BRIEF IFR
CONDITIONS POSSIBLE.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1100 PM TUESDAY...SW WINDS WILL PERSIST FOR THE REMAINDER OF
THE NIGHT AT UP TO AROUND 15 KT. SEAS WILL BE 2 TO 3 FT. A 9 TO 10
SECOND EASTERLY SWELL WAS BEING OBSERVED AT THE BUOYS.
A WEAK TROUGH OF LOW PRESSURE ACROSS THE INLAND CAROLINAS AND
BERMUDA HIGH PRESSURE WILL BETTER DEFINE THE PRESSURE GRADIENT...
ESPECIALLY ON WED. WE DO EXPECT SHOWERS AND THUNDERSTORMS TO BEGIN
BLOSSOMING ACROSS THE WATERS AFTER MIDNIGHT. MARINERS SHOULD
EXPECT REDUCED VISIBILITY IN HEAVY RAIN WITH THIS ACTIVITY.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...WEAK RETURN FLOW ON WEDNESDAY WILL VEER TO
THE S-SW ON THU AS COLD FRONT REACHES INTO THE CAROLINAS. THIS
WILL PRODUCE A SLIGHT TIGHTENING OF GRADIENT AND ALLOW WINDS TO
INCREASE UP TO 15 KT LATE WED INTO THU. THIS SLIGHT INCREASE IN
WINDS WILL PRODUCE ENOUGH SOUTHERLY PUSH TO INCREASE SEAS JUST
ABOVE 3 FT.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 300 PM TUESDAY...A COLD FRONT DROPS INTO THE AREA. THIS
BOUNDARY WILL BE FAIRLY SLOW MOVING AND ALSO DECELERATING MAKING
FOR A VERY GRADUAL WIND SHIFT ACROSS THE WATERS WHILE SEAS REMAIN
CAPPED AT 2 FT. E TO NE WINDS ON SATURDAY EXPECTED TO STAY 10 KT
OR LESS BEHIND THE BOUNDARY AND NO CHANGE IN WAVE HEIGHT EVEN IF
THE FROPA SLIGHTLY STEEPENS WAVE FACES FOR A BRIEF TIME. THE
BOUNDARY REMAINS JUST TO OUR SOUTH IN A DISSIPATING STATE BY
SUNDAY AND IT MAY IN FACT BE TOUGH TO FIND ON SURFACE MAPS. THE
HIGH THAT HAD BEEN BUILDING IN BEHIND IT WEAKENS RAPIDLY WITH THE
NET LOCAL RESULT LITTLE CHANGE IN WIND OR WAVES FROM THOSE OF
SATURDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RJD
SHORT TERM...RGZ
LONG TERM...MBB
AVIATION...DL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1031 PM EDT TUE AUG 18 2015
.SYNOPSIS...
HIGH PRESSURE OVER THE AREA WITH LOW PRESSURE MOVING INTO EASTERN
NORTH CAROLINA WEDNESDAY. FRONT WILL APPROACH THE AREA AND IS
EXPECTED TO CROSS THE AREA FRIDAY. HIGH PRESSURE WILL BUILD NORTH OF
THE AREA OVER THE WEEKEND. ANOTHER SYSTEM WILL AFFECT THE AREA EARLY
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6AM WEDNESDAY/...
AS OF 1015 PM TUE...SHOWERS ACTIVITY HAVE DIMINISHED THIS
EVENING. HOWEVER...THERE ARE MORE SHOWERS EXPECTED MOVE INTO THE
AREA FROM THE WEST AND SOUTHWEST DIRECTION. THE HRRR MODEL IS
SHOWING THESE SHOWERS WILL DIMINISH AS IT ENTERS INTO EASTERN
NC...SO THEREFORE REDUCED POPS TO THE LOW END OF CHANCE FOR THE
OVERNIGHT.
PREV DISC...RIDGE ALOFT OVER THE EAST COAST WITH TROUGHING
COVERING MUCH OF THE REST OF THE COUNTRY. HIGH PRESSURE OFFSHORE
AT THE SURFACE. NOT MUCH TO TRIGGER ON AT THE SURFACE...HOWEVER
SOME MID LEVEL ENERGY MOVING THROUGH THE FLOW FOR SUSTAINED
PRECIPITATION CHANCES THROUGH THE NIGHT. SOUTH AND SOUTHWEST FLOW
ACROSS THE SOUTHEAST US WILL PUMP GLFMX MOISTURE INTO EASTERN
NORTH CAROLINA WITH PRECIPITABLE WATER VALUES OVER TWO INCHES.
COULD SEE SOME HEAVY DOWNPOURS WITH LOCALIZED FLOODING IN LOW
LYING AREAS. WILL SEE TEMPERATURES IN THE LOWER TO MIDDLE 70S
ACROSS MUCH OF THE AREA.
&&
.SHORT TERM /WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
AS OF 230 PM TUE...RIDGE ALOFT WILL BESHUNTED OFFSHORE TOWARD THE
SOUTHEAST AS TROUGH PUSHES EASTWARD ACROSS THE COUNTRY. NOT MUCH
DIFFERENCE IN MODEL GUIDANCE IN HANDLING THIS SITUATION. LOTS OF
MOISTURE WILL CONTINUE TO STREAM INTO THE AREA WITH THE GULF OPEN
IN SOUTH SOUTHWESTERLY LOW LEVEL FLOW. FORECAST SOUNDINGS SHOWING
PRECIPITABLE WATERS CONTINUING OVER TWO INCHES THROUGH THE DAY
WEDNESDAY. NO DEFINITE FEATURE TO KEY ON AS A TRIGGER...HOWEVER
MODELS ARE HINTING AT WEAK LOW LEVEL CONVERGENCE SETTING UP. WILL
ALSO HAVE WEAK ENERGY IN THE MID LEVEL FLOW. INCREASE IN
INSTABILITY AS HEIGHTS LOWER AHEAD OF APPROACHING MID LEVEL
TROUGH. SO WILL SEE BETTER CHANCES OF THUNDER.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
AS OF 230 PM TUESDAY...A GOOD CHANCE OF RAIN THROUGH LATE
WEEK...THEN SOME DRYING FOR THE WEEKEND.
WEDNESDAY NIGHT THROUGH FRIDAY...A MOIST FLOW FROM BOTH THE GULF
AND ATLANTIC WILL PUSH PRECIPITABLE WATER VALUES TO AROUND 2
INCHES THROUGH THE PERIOD WITH CHANCE POPS WEDNESDAY NIGHT INTO
FRIDAY WITH SOME WEAK MID-LEVEL ENERGY. DESPITE INCREASED CLOUD
COVER...HIGH TEMPERATURES WILL STILL RISE WELL INTO THE 80S WITH
CLOSE TO 90 INLAND THURSDAY. OVERNIGHT LOWS WILL BE IN THE LOW/MID
70S.
FRIDAY NIGHT THROUGH SATURDAY...A COLD FRONT WILL MOVE OFFSHORE
FRIDAY AFTERNOON WITH A GENERAL NE/E FLOW DEVELOPING. WILL
MAINTAIN LOW POPS WITH PRECIPITABLE WATER REMAINING FAIRLY HIGH
(CLOSE TO 2 INCHES)...BUT TEMPERATURES WILL BE A DEGREE OR TWO
COOLER THROUGH THE PERIOD.
SATURDAY NIGHT THROUGH MONDAY...RAIN CHANCES WILL BE MINIMAL
THROUGH THIS PERIOD WITH WEAK UPPER LEVEL RIDGING AND SOME DRIER
IN THE LOWER LEVELS.
MONDAY NIGHT AND TUESDAY...RAIN CHANCES INCREASE ONCE AGAIN WITH
WEAK UPPER LEVEL TROUGHING AND INCREASED SW FLOW.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM /THROUGH 18Z WEDNESDAY/...
AS OF 7 PM TUESDAY...GENERALLY VFR THROUGH THE SHORT TERM. WILL
MAINTAIN VCSH FOR TAF SITES BUT WILL KEEP CIGS IN VFR RANGE.
CLOUDS MAY LOWER TO MVFR LEVELS TONIGHT WITH A MOIST BOUNDARY
LAYER IN PLACE, THOUGH WILL CAP AT 4KFT FOR NOW. VSBYS WILL LIKELY
LOWER GIVEN AMPLE MOISTURE IN THE BOUNDARY LAYER. THUS HAVE
LOWERED VSBYS INLAND TO ACCOUNT FOR BETTER MOISTURE FLUX AND CALM
WINDS OVERNIGHT. LOW LEVEL MOISTURE WILL LIKELY MIX OUT DURING THE
MORNING HOURS WITH CONTINUED HIGH CLOUDS. SOME MORE SHOWERS
POSSIBLE WEDNESDAY. LIGHT SOUTHERLY FLOW THROUGH THE PERIOD.
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 245 PM TUESDAY...THINK MUCH OF THE PERIOD WILL BE IN THE VFR
CATEGORY. WILL LIKELY SEE PERIODS OF SUB-VFR VSBYS AND CEILINGS
DURING ANY AFTERNOON/EVENING SHOWERS OR THUNDERSTORMS THROUGH
SATURDAY. ANY AREAS THAT RECEIVE RAIN WILL BE SUSPECTIBLE TO SOME
LATE NIGHT FOG AND STRATUS AS WELL. VFR CONDITIONS SHOULD PREVAIL
SUNDAY.
&&
.MARINE...
SHORT TERM /TONIGHT AND WEDNESDAY/...
AS OF 1015 PM TUE...CURRENT FORECAST IN GREAT SHAPE...NO UPDATE
NEEDED. THE LATEST BUOY OBS ARE SHOWING SOUTH/SOUTHWEST 5 TO 10
KTS WITH 2 TO 3 FT SEAS.
OVERALL, A WEAK GRADIENT ACROSS THE EASTERN NORTH CAROLINA
COASTAL WATERS TONIGHT. SOUTHWEST FLOW WITH WEAK HIGH PRESSURE TO
THE EAST AND APPROACHING FRONT FROM THE WEST. SPEEDS WILL BE
GENERALLY 10 TO 15 KNOTS AND SEAS 1 TO 3 FEET. WEAK BOUNDARY WILL
SET UP ACROSS THE WATERS LATER TONIGHT WITH FLOW IN THE NORTHERN
WATERS BECOMING SOUTH SOUTHEASTERLY. LOCAL MODELS SHOWING LOW
PRESSURE MOVING UP THE COAST WEDNESDAY...WHICH WILL MAKE THE WIND
MORE VARIABLE ACROSS THE WATERS. HOWEVER HAVE KEEP THINGS SIMPLE
WITH SOUTHEASTERLY FLOW IN THE NORTHERN WATERS AND SOUTHWESTERLY
FLOW IN THE SOUTHERN WATERS. GRADIENT WILL REMAIN RATHER LOOSE FOR
SPEEDS IN THE 10 TO 15 KNOT RANGE THROUGH THE DAY AND SEAS 1 TO 3
FEET.
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 255 PM TUESDAY...GENERALLY RATHER BENIGN MARINE CONDITIONS
EXPECTED FOR THE EXTENDED PERIOD. MAY SEE SOUTH/SOUTHWEST WINDS
INCREASE TO 10 TO 15 KNOTS THURSDAY AFTERNOON AND THURSDAY NIGHT
AHEAD OF THE COLD FRONT. BEHIND THE FRONT...GENERALLY EXPECT NE/E
WINDS 10 KNOTS OR LESS THROUGH THE WEEKEND. FOR SEAS...USED LOCAL
SWAN WITH WAVEWATCH FOR THE LATER PERIODS. SEAS THROUGH THE
EXTENDED PERIOD SHOULD BE 2 TO 3 FEET AND ARE NOT LIKELY TO EXCEED
4 FEET THROUGH SUNDAY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...CCG
NEAR TERM...CCG/BM
SHORT TERM...CCG
LONG TERM...CTC
AVIATION...CTC/HSA/LEP
MARINE...CCG/CTC/BM
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1015 PM CDT TUE AUG 18 2015
.UPDATE...
ISSUED AT 1014 PM CDT TUE AUG 18 2015
MONITORING RADAR CLOSELY....AND LOOP OVER THE PAST 2 HOURS SHOWS
THE NW EDGE HOLDING STRONG FINGAL-HILLSBORO-FERTILE THEN TO NEAR
TRF TO JUST SOUTH OF BAUDETTE. THERE IS A DRY SLOT WORKING INTO SE
FCST AREA. DID UPDATE POPS SOME TO HAVE 90-100 IN THAT LISBON-
FARGO-BEMIDJI BAND.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 242 PM CDT TUE AUG 18 2015
FORECAST CHALLENGE FOR TONIGHT IS WHICH HI RES MODEL TO FOLLOW FOR
EVOLUTION OF LOW PRESSURE SYSTEM OVER FAR SERN SD AS IT MOVES
EAST AND THEN NORTH...CLIPPING SOUTHERN AND EASTERN PORTIONS OF
THE CWA. HRRR HAS CONSISTENTLY VERIFIED WITH PLACEMENT OF PRECIP
BEST EACH HOUR...ALTHOUGH EARLIER RUNS THAT SPREAD RAIN AS FAR
NORTH AS FARGO WERE THOUGHT TO BE OVERLY BULLISH AND I HAD FAVORED
THE NMM/ARW...WHICH KEPT PRECIP FURTHER SOUTH WITH THE NE FLOW IN
SFC-H850 LAYER. HOWEVER...15Z HRRR RUN DID A VERY GOOD JOB WITH
PLACEMENT OF PRECIP VERIFIED BY 19Z RADAR IMAGERY. THEREFORE WILL
CONTINUE HRRR TRENDS THROUGH THE EVENING THROUGH 06Z...THEN A FCST
BLEND THROUGH END OF EVENT FOR OUR CWA.
TONIGHT AND TOMORROW...PRECIP OVER SOUTHWEST MN WILL CONTINUE TO
LIFT FROM SW MN INTO W CNTRL MN...HOWEVER WITH SFC LOW MOVING
NE...DO NOT EXPECT RAIN TO LIFT MUCH FURTHER NORTH THAN HILLSBORO
WITHIN THE RRV. LOW BEGINS TO LIFT MORE NORTHWARD AFTER
MIDNIGHT...EVENTUALLY MOVING OVER LAKE SUPERIOR WED AFTN. QUESTION
IS HOW MUCH PRECIP WILL BACK INTO NW MN...AND CURRENT TRENDS ARE
KEEPING MOST OF THE NORTHERN VALLEY AND KITTSON/MARSHALL/NW POLK
COUNTIES DRY. 00Z ECMWF WAS THE FURTHEST WEST AND HAVE DISCOUNTED
IT...PREFERRING A GFS/GEM/NAM BLEND FOR WEDNESDAY POPS. HIGHEST
RAINFALL RATES WITHIN DEFORMATION ZONE SHOULD BE OVER CNTRL
MN...WHERE HPC QPF IS SHOWING UP TO TWO AND A QUARTER INCHES OF
PRECIP WITH A SHARP...DECLINING GRADIENT WESTWARD INTO THE
SOUTHERN VALLEY. CURRENT PRECIP TOTAL THOUGHTS ARE AROUND HALF AN
INCH IN FARGO...LITTLE IF ANY IN GRAND FORKS...RISING TO AROUND 2
INCHES AS FAR EAST AS PARK RAPIDS.
WED NIGHT...SYSTEM PULLS OUT OF LAKE SUPERIOR REGION INTO CNTRL
ONTARIO...SLOWLY PULLING PRECIP OUR OF FAR EAST AND NORTHEASTERN
ZONES BY 12Z THU. CLEARING IN THE WEST...IN ADDITION TO RELAXING
PRESSURE GRADIENT WINDS...WILL ALLOW OVERNIGHT LOWS TO FALL INTO
THE UPPER TO MID 40S ACROSS MOST OF THE REGION...WARMEST IN THE
FAR EAST WHERE CLOUD COVER WILL LINGER OVERNIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 242 PM CDT TUE AUG 18 2015
THURSDAY AND FRIDAY...HIGH PRESSURE MOVES INTO REGION BRINGING
INCREASED SOLAR AND REBOUNDING TEMPERATURES TO NEAR SEASONAL NORMS
ON THURSDAY. RETURN FLOW SETS UP THU NIGHT INTO FRIDAY AND WEAK
SOUTHERLY FLOW THROUGH THE DAY FRIDAY WILL RESULT IN TEMPS
CLIMBING BACK INTO THE MID 80S.
THU NIGHT INTO FRIDAY...PASSING MID LEVEL TROUGH SATURDAY WILL DRAG
ANOTHER COLD FRONT ACROSS THE REGION. TIMING OF FRONT WOULD BRING
BEST T CHANCES ACROSS EASTERN HALF OF THE FA. SUNDAY WILL BE
COOLER FOLLOWED BY MODERATING TEMPERATURES INTO EARLY NEXT WEEK
WITH DRY CONDITIONS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 655 PM CDT TUE AUG 18 2015
LIGHT RAIN BAND FROM FARGO AND READY TO MOVE INTO BEMIDJI. CLOUDS
VFR RANGE...BUT SHOULD LOWER SOME TONIGHT INTO WEDNESDAY ESP IN
THE HIGHER TERRAIN OF NCNTRL MN AROUND BJI-PKD WHERE MVFR CIGS
LIKELY LATER TONIGHT INTO WEDNESDAY. O/W GFK SHOULD REMAIN
DRY...TVF ON THE EDGE WITH PSBL -RA....DRY DVL. NORTH WINDS WILL
INCREASE LATER TONIGHT AND MORE SO WEDNESDAY TO THE 12 TO 25 KT
RANGE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...SPEICHER
LONG TERM...SPEICHER/VOELKER
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
704 PM CDT TUE AUG 18 2015
.UPDATE...
ISSUED AT 655 PM CDT TUE AUG 18 2015
FCST IN GOOD SHAPE. WATCHING NW EDGE OF RAIN SLOWLY TOWARD
CROOKSTON-HILLSBORO LINE. MOSTLY SPRINKLES WITH THIS BAND TO 0.01
PER FOSSTON OBS. MAIN RAIN BAND SITTING OVER NE SD IN THE ABERDEEN
AREA AND INTO PARTS OF SE ND TOWARD LAMOURE. OVERALL EVOLUTION OF
RAIN BAND FOLLOWING HRRR PRETTY WELL AND WILL CONTINUE USE. IT
BRINGS SPRINKLES TO JUST BARELY E-SE OF GFK...AND THIS IS WHAT
POPS HAVE NOW.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 242 PM CDT TUE AUG 18 2015
FORECAST CHALLENGE FOR TONIGHT IS WHICH HI RES MODEL TO FOLLOW FOR
EVOLUTION OF LOW PRESSURE SYSTEM OVER FAR SERN SD AS IT MOVES
EAST AND THEN NORTH...CLIPPING SOUTHERN AND EASTERN PORTIONS OF
THE CWA. HRRR HAS CONSISTENTLY VERIFIED WITH PLACEMENT OF PRECIP
BEST EACH HOUR...ALTHOUGH EARLIER RUNS THAT SPREAD RAIN AS FAR
NORTH AS FARGO WERE THOUGHT TO BE OVERLY BULLISH AND I HAD FAVORED
THE NMM/ARW...WHICH KEPT PRECIP FURTHER SOUTH WITH THE NE FLOW IN
SFC-H850 LAYER. HOWEVER...15Z HRRR RUN DID A VERY GOOD JOB WITH
PLACEMENT OF PRECIP VERIFIED BY 19Z RADAR IMAGERY. THEREFORE WILL
CONTINUE HRRR TRENDS THROUGH THE EVENING THROUGH 06Z...THEN A FCST
BLEND THROUGH END OF EVENT FOR OUR CWA.
TONIGHT AND TOMORROW...PRECIP OVER SOUTHWEST MN WILL CONTINUE TO
LIFT FROM SW MN INTO W CNTRL MN...HOWEVER WITH SFC LOW MOVING
NE...DO NOT EXPECT RAIN TO LIFT MUCH FURTHER NORTH THAN HILLSBORO
WITHIN THE RRV. LOW BEGINS TO LIFT MORE NORTHWARD AFTER
MIDNIGHT...EVENTUALLY MOVING OVER LAKE SUPERIOR WED AFTN. QUESTION
IS HOW MUCH PRECIP WILL BACK INTO NW MN...AND CURRENT TRENDS ARE
KEEPING MOST OF THE NORTHERN VALLEY AND KITTSON/MARSHALL/NW POLK
COUNTIES DRY. 00Z ECMWF WAS THE FURTHEST WEST AND HAVE DISCOUNTED
IT...PREFERRING A GFS/GEM/NAM BLEND FOR WEDNESDAY POPS. HIGHEST
RAINFALL RATES WITHIN DEFORMATION ZONE SHOULD BE OVER CNTRL
MN...WHERE HPC QPF IS SHOWING UP TO TWO AND A QUARTER INCHES OF
PRECIP WITH A SHARP...DECLINING GRADIENT WESTWARD INTO THE
SOUTHERN VALLEY. CURRENT PRECIP TOTAL THOUGHTS ARE AROUND HALF AN
INCH IN FARGO...LITTLE IF ANY IN GRAND FORKS...RISING TO AROUND 2
INCHES AS FAR EAST AS PARK RAPIDS.
WED NIGHT...SYSTEM PULLS OUT OF LAKE SUPERIOR REGION INTO CNTRL
ONTARIO...SLOWLY PULLING PRECIP OUR OF FAR EAST AND NORTHEASTERN
ZONES BY 12Z THU. CLEARING IN THE WEST...IN ADDITION TO RELAXING
PRESSURE GRADIENT WINDS...WILL ALLOW OVERNIGHT LOWS TO FALL INTO
THE UPPER TO MID 40S ACROSS MOST OF THE REGION...WARMEST IN THE
FAR EAST WHERE CLOUD COVER WILL LINGER OVERNIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 242 PM CDT TUE AUG 18 2015
THURSDAY AND FRIDAY...HIGH PRESSURE MOVES INTO REGION BRINGING
INCREASED SOLAR AND REBOUNDING TEMPERATURES TO NEAR SEASONAL NORMS
ON THURSDAY. RETURN FLOW SETS UP THU NIGHT INTO FRIDAY AND WEAK
SOUTHERLY FLOW THROUGH THE DAY FRIDAY WILL RESULT IN TEMPS
CLIMBING BACK INTO THE MID 80S.
THU NIGHT INTO FRIDAY...PASSING MID LEVEL TROUGH SATURDAY WILL DRAG
ANOTHER COLD FRONT ACROSS THE REGION. TIMING OF FRONT WOULD BRING
BEST T CHANCES ACROSS EASTERN HALF OF THE FA. SUNDAY WILL BE
COOLER FOLLOWED BY MODERATING TEMPERATURES INTO EARLY NEXT WEEK
WITH DRY CONDITIONS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 655 PM CDT TUE AUG 18 2015
LIGHT RAIN BAND FROM FARGO AND READY TO MOVE INTO BEMIDJI. CLOUDS
VFR RANGE...BUT SHOULD LOWER SOME TONIGHT INTO WEDNESDAY ESP IN
THE HIGHER TERRAIN OF NCNTRL MN AROUND BJI-PKD WHERE MVFR CIGS
LIKELY LATER TONIGHT INTO WEDNESDAY. O/W GFK SHOULD REMAIN
DRY...TVF ON THE EDGE WITH PSBL -RA....DRY DVL. NORTH WINDS WILL
INCREASE LATER TONIGHT AND MORE SO WEDNESDAY TO THE 12 TO 25 KT
RANGE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...SPEICHER
LONG TERM...SPEICHER/VOELKER
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1215 AM CDT MON AUG 17 2015
.UPDATE...
ISSUED AT 1213 AM CDT MON AUG 17 2015
JUST A MINOR UPDATE TO LOW TEMPERATURES BY A FEW DEGREES. CURRENT
OBSERVATION TRENDS WOULD INDICATE WIDESPREAD READINGS IN THE MID
40S ARE LIKELY TONIGHT.
UPDATE ISSUED AT 953 PM CDT SUN AUG 16 2015
BLENDED IN CURRENT CONDITIONS TO THE FORECAST WITH ONLY ISOLATED
SHOWERS LEFT IN THE SOUTHERN JAMES RIVER VALLEY. AFTER
COLLABORATION WITH SURROUNDING OFFICES...OPTED TO REMOVE THE
OVERNIGHT POP IN SOUTHWEST NORTH DAKOTA. THE LATEST NAM KEEPS IT
DRY IN THAT REGION OVERNIGHT...AND THAT LINES UP WITH HRRR AND RAP
13 TOO. ONE AREA TO MONITOR OVERNIGHT FOR A POTENTIAL SHOWER IS
THE NORTH CENTRAL WHERE THE RAP 13 AND HRRR BOTH HINT AT THE
POSSIBILITY LATE TONIGHT / EARLY MONDAY MORNING.
UPDATE ISSUED AT 902 PM CDT SUN AUG 16 2015
MADE ANOTHER QUICK UPDATE AS THE SHOWERS CONTINUE THEIR TREK
EASTWARD. DECIDED TO REMOVE THE MENTION OF THUNDER WITH ONLY
LIMITED INSTABILITY AVAILABLE.
UPDATE ISSUED AT 654 PM CDT SUN AUG 16 2015
MAIN CHANGE WAS TO HOLD ONTO SHOWERS / ISOLATED THUNDERSTORMS A
COUPLE MORE HOURS THIS EVENING. THE SHORT TERM MODELS HAVE
STRUGGLED TO HANDLE THE ONGOING PRECIPITATION. IT APPEARS MUCH OF
THE ACTIVITY IS IN ASSOCIATION WITH THE RIGHT REAR QUADRANT OF AN
UPPER LEVEL JET STREAK. THIS FEATURE IS FORECAST TO WEAKEN THIS
EVENING AS IT MOVE SOUTH AND EAST. WILL STILL TREND TO A DRY
FORECAST LATER THIS EVENING. HAVE ALSO INCREASED SKY COVER THIS
EVENING IN ASSOCIATION WITH THE PRECIPITATION.
UPDATE ISSUED AT 521 PM CDT SUN AUG 16 2015
QUICK UPDATE TO SPREAD THE ISOLATED SHOWERS / THUNDERSTORMS A ROW
OF COUNTIES FARTHER EAST. WE ALSO BLENDED IN CURRENT CONDITIONS...
OTHERWISE THE FORECAST IS ON TRACK.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 306 PM CDT SUN AUG 16 2015
CURRENT SURFACE ANALYSIS PLACES LOW OVER NORTHERN ONTARIO WITH
COLD FRONT DROPPING THROUGH THE UPPER MIDWEST INTO THE CENTRAL
PLAINS. COOL HIGH PRESSURE CONTINUES TO SLIDE OVER THE NORTHERN
ROCKIES INTO THE NORTHERN PLAINS BRINGING REFRESHING TEMPERATURES
AFTER A HOT DAY YESTERDAY. UPPER LEVEL ANALYSIS BRING CYCLONIC
WEST/SOUTHWESTERLY FLOW TO THE AREA WITH A VARIETY OF WEAK SHORT
WAVES NOTED AND UPPER JET STREAK PASSING THROUGH. THIS CONTINUES
TO BRING SOME WEAK SHOWERS/THUNDERSTORMS TO SOUTHERN/WESTERN
PORTIONS OF THE AREA.
FOR THE REST OF THIS AFTERNOON INTO TONIGHT...SHOWERS/WEAK STORMS
OVER THE SOUTHERN JAMES RIVER VALLEY WILL CONTINUE TO PUSH OFF TO
THE EAST...WHILE PRECIPITATION OVER THE WESTERN PORTIONS OF THE
STATE AFFILIATED WITH PASSING JET STREAK MAY LINGER INTO THE
EARLY EVENING BEFORE DISSIPATING. WITH LIMITED INSTABILITY TO DEAL
WITH...STORMS SHOULD REMAIN WEAK. A COOL NIGHT IS EXPECTED AS
SURFACE HIGH SETTLES OVER THE REGION.
ON MONDAY...BROAD CYCLONIC FLOW REMAINS OVER THE REGION WITH
PRECIPITATION CHANCES INCREASING PRIMARILY OVER SOUTHWESTERN AREAS
THROUGH MID-DAY BEFORE SPREADING TOWARDS THE NORTHEAST LATER IN
THE DAY. WILL MENTION MAINLY SHOWERS BUT STILL KEEP LOW THUNDER
CHANCES IN THE FORECAST WITH MINIMAL INSTABILITY NOTED.
TEMPERATURES WILL REMAIN BELOW AVERAGE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 354 PM CDT SUN AUG 16 2015
THE FORECAST FOCUS IS ON THE POTENTIAL FOR TWO RAIN EVENTS THIS
WEEK.
MODELS AND ENSEMBLES AGREE THAT BROAD SCALE CYCLONIC FLOW ACROSS THE
NORTHERN TIER WILL DIRECT TWO MIDDLE LEVEL ALASKA SHORTWAVES INTO
THE DAKOTAS AND SOUTHERN CANADA THIS WEEK. LARGE SCALE ASCENT
ASSOCIATED WITH THE FIRST WILL SPREAD ACROSS NORTH DAKOTA BEGINNING
ON MONDAY NIGHT...AND WILL SUPPORT PRECIPITATION THROUGH TUESDAY
EVENING...PER THE 06 UTC GEFS AND 12 UTC GFS/ECMWF/GEM GLOBAL.
CONVECTIVE INSTABILITY IS LIMITED IN GUIDANCE...SO GRIDDED FORECASTS
INDICATE ONLY A SLIGHT CHANCE FOR THUNDERSTORMS DESPITE LIKELY
SHOWERS.
THERE IS GREATER UNCERTAINTY WITH STRENGTH OF THE SECOND
SYSTEM...THOUGH THERE IS GOOD AGREEMENT THAT H5 HEIGHT FALLS WILL
SPREAD INTO WESTERN NORTH DAKOTA ON FRIDAY...WITH ASSOCIATED
THUNDERSTORM ACTIVITY LASTING INTO SUNDAY. THE 12 UTC ECMWF IS ON
THE AMPLIFIED SIDE OF THE 06 UTC GEFS ENSEMBLE SPREAD...AND THE 12
UTC GFS IS IN THE MIDDLE. SINCE THE SHORTWAVE WILL NOT CROSS THE
BERING STRAIT UNTIL WEDNESDAY...THE ENVELOPE OF SOLUTIONS WILL
PROBABLY HAVE LARGE SPREAD UNTIL MIDWEEK.
THE AFOREMENTIONED BROAD CYCLONIC FLOW WILL SUPPORT TEMPERATURES
NEAR OR BELOW NORMAL ACROSS THE NORTHERN HIGH PLAINS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1213 AM CDT MON AUG 17 2015
VFR CONDITIONS AT ALL TAF SITES THROUGH THE TAF PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AJ
SHORT TERM...JJS
LONG TERM...SCHECK
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
633 AM EDT MON AUG 17 2015
.SYNOPSIS...
MOISTURE INCREASES MONDAY THROUGH WEDNESDAY. COLD FRONT THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
NO CHANGES THIS MORNING.
PREVIOUS DISCUSSION...
WATER VAPOR IMAGERY SHOWING THE DRAW OF DEEPER MOISTURE INTO THE
CWA IN RESPONSE TO AN UPPER LEVEL LOW PRESSURE SYSTEM LOCATED OVER
THE CONFLUENCE OF THE OHIO AND MISSISSIPPI RIVERS. NAM CONTINUES TO
MAINTAIN AN AGGRESSIVE NATURE WITH THE RESULTANT CONVECTIVE CHANCES
TODAY WHILE THE HRRR AND RAP ARE FAR LESS SO. FEEL MORE COMFORTABLE
WITH THESE TAMER MODELS...AND WILL BE INTERESTED TO SEE THEIR
SOLUTIONS FOR THE ACTIVITY TONIGHT. PUTTING A LOT OF STOCK INTO THE
UPPER LEVEL LOW MOVING THROUGH THE AREA WITH LIKELY POPS...AGAIN
MUCH MORE AGGRESSIVE IN THE NAM SOLUTION.
MAV HAS BEEN THE HOT GUIDANCE OF CHOICE LATELY...SO LEAN ON THIS
HEAVILY FOR THE AFTERNOON HIGHS TODAY. LIKE HOW IT KEEPS SOME OF THE
SOUTHERN ZONES SLIGHTLY COOLER THAN THE NORTH GIVEN THE ARRIVAL OF
CLOUDS EARLIER IN THE DAY AND THE BETTER CHANCES FOR CONVECTION.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
MODELS SHOW A SERIES OF UPPER DISTURBANCES MOVING THROUGH A DEEPER
MOIST SOUTHWEST FLOW TUESDAY AND WEDNESDAY...BEFORE A COLD FRONT
MOVES THROUGH ON THURSDAY TO BRING IN DRIER AND COOLER AIR FOR THE
REMAINDER OF THE WORK WEEK. MODELS HINT AT ONE DISTURBANCE MOVING
ACROSS EARLIER ON TUESDAY...ANOTHER ONE TUESDAY NIGHT AND EARLY
WEDNESDAY...BEFORE THE COLD FRONT MOVES ACROSS ON THURSDAY. DESPITE
THE LACK OF A LOW LEVEL FOCUS BEFORE THE COLD FRONT...THE
DISTURBANCES COMBINING WITH PW`S AOA 1.5 INCHES SUGGESTS HIGH POPS
FOR SHOWERS AND THUNDERSTORMS. WILL...FOCUS HIGHER POPS ON THE TWO
AFOREMENTIONED DISTURBANCES...BUT OTHERWISE KEEP LOWER POPS IN THE
JUICY AIR IN PLACE. SUNSHINE SHOULD BE LIMITED AND SO HIGH TEMPS
WILL BE IN THE 80S. SHOWERS AN STORMS RAMP UP AGAIN WEDNESDAY NIGHT
AND EARLY THURSDAY ALONG AND AHEAD OF THE COLD FRONT...DECREASING
FROM NORTHWEST TO SOUTHEAST DURING THURSDAY AS DRIER AND SOMEWHAT
COOLER AIR MOVES IN. HIGH PRESSURE WILL SETTLE IN FOR THURSDAY NIGHT
AND FRIDAY...WITH MOSTLY DRY WEATHER AND HIGH TEMPS AROUND 80
DEGREES FRIDAY...BUT WILL LEAVE JUST A LOW POP IN THE SOUTH AS
MODELS INDICATE SOME LINGERING MOISTURE DOWN THERE.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
A COLD FRONT PASSES ON THURSDAY. THERE IS STILL NOT GREAT MODEL
CONSENSUS...WITH THE EURO GIVING THE STRONGEST SOLUTION. FOR THE
MOST PART THE MAJOR DYNAMICS WILL BE NORTH OF THE FORECAST AREA.
HAVE INCREASED POPS WITH THE FRONT FROM WHAT WAS IN THE PREVIOUS
GRIDS. HAVE EVEN INCLUDED LIKELY OVER THE MOUNTAINS. NOT SURE HOW
QUICKLY IT WILL DRY OUT AS THE FRONT MIGHT GET HUNG UP. AT THIS
TIME WENT WITH THE PREVIOUS SCENARIO AND DRIED POPS OUT STARTING
FRIDAY.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
CIRRUS CLOUDS WILL BE ON THE INCREASE THROUGH THE DAY...WITH
CUMULUS FORMATION AS WELL WITH AN APPROACHING UPPER LEVEL TROUGH.
SHOWERS AND THUNDERSTORMS WILL BE SLOW TO AFFECT THE
TERMINALS...WITH BETTER CHANCES AFTER THE 00Z TUESDAY TIME FRAME.
THESE CHANCES WILL CARRY OVER INTO THE OVERNIGHT AND WILL NOT BE
RELEGATED TO THE DAYTIME HEATING HOURS...THANKS TO THE
AFOREMENTIONED UPPER LEVEL FEATURE.
NO FOG TONIGHT DUE TO CLOUDS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: MAY NEED MORE VCTS/TSRA TODAY AT BKW AND HTS.
TIMING TONIGHT IS IN QUESTION.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 08/17/15
UTC 1HRLY 09 10 11 12 13 14 15 16 17 18 19 20
EDT 1HRLY 05 06 07 08 09 10 11 12 13 14 15 16
CRW CONSISTENCY L L L M H H H H H H H H
HTS CONSISTENCY L L L M H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY L L L L H H H H H H H H
PKB CONSISTENCY L L L M H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z TUESDAY...
IFR CONDITIONS POSSIBLE IN AREAS OF SHOWERS AND THUNDERSTORMS WITH
THE COLD FRONT ON THURSDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JMV/26
NEAR TERM...26
SHORT TERM...JMV
LONG TERM...FB
AVIATION...26
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
351 AM EDT MON AUG 17 2015
.SYNOPSIS...
MOISTURE INCREASES MONDAY THROUGH WEDNESDAY. COLD FRONT THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
WATER VAPOR IMAGERY SHOWING THE DRAW OF DEEPER MOISTURE INTO THE
CWA IN RESPONSE TO AN UPPER LEVEL LOW PRESSURE SYSTEM LOCATED OVER
THE CONFLUENCE OF THE OHIO AND MISSISSIPPI RIVERS. NAM CONTINUES TO
MAINTAIN AN AGGRESSIVE NATURE WITH THE RESULTANT CONVECTIVE CHANCES
TODAY WHILE THE HRRR AND RAP ARE FAR LESS SO. FEEL MORE COMFORTABLE
WITH THESE TAMER MODELS...AND WILL BE INTERESTED TO SEE THEIR
SOLUTIONS FOR THE ACTIVITY TONIGHT. PUTTING A LOT OF STOCK INTO THE
UPPER LEVEL LOW MOVING THROUGH THE AREA WITH LIKELY POPS...AGAIN
MUCH MORE AGGRESSIVE IN THE NAM SOLUTION.
MAV HAS BEEN THE HOT GUIDANCE OF CHOICE LATELY...SO LEAN ON THIS
HEAVILY FOR THE AFTERNOON HIGHS TODAY. LIKE HOW IT KEEPS SOME OF THE
SOUTHERN ZONES SLIGHTLY COOLER THAN THE NORTH GIVEN THE ARRIVAL OF
CLOUDS EARLIER IN THE DAY AND THE BETTER CHANCES FOR CONVECTION.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
MODELS SHOW A SERIES OF UPPER DISTURBANCES MOVING THROUGH A DEEPER
MOIST SOUTHWEST FLOW TUESDAY AND WEDNESDAY...BEFORE A COLD FRONT
MOVES THROUGH ON THURSDAY TO BRING IN DRIER AND COOLER AIR FOR THE
REMAINDER OF THE WORK WEEK. MODELS HINT AT ONE DISTURBANCE MOVING
ACROSS EARLIER ON TUESDAY...ANOTHER ONE TUESDAY NIGHT AND EARLY
WEDNESDAY...BEFORE THE COLD FRONT MOVES ACROSS ON THURSDAY. DESPITE
THE LACK OF A LOW LEVEL FOCUS BEFORE THE COLD FRONT...THE
DISTURBANCES COMBINING WITH PW`S AOA 1.5 INCHES SUGGESTS HIGH POPS
FOR SHOWERS AND THUNDERSTORMS. WILL...FOCUS HIGHER POPS ON THE TWO
AFOREMENTIONED DISTURBANCES...BUT OTHERWISE KEEP LOWER POPS IN THE
JUICY AIR IN PLACE. SUNSHINE SHOULD BE LIMITED AND SO HIGH TEMPS
WILL BE IN THE 80S. SHOWERS AN STORMS RAMP UP AGAIN WEDNESDAY NIGHT
AND EARLY THURSDAY ALONG AND AHEAD OF THE COLD FRONT...DECREASING
FROM NORTHWEST TO SOUTHEAST DURING THURSDAY AS DRIER AND SOMEWHAT
COOLER AIR MOVES IN. HIGH PRESSURE WILL SETTLE IN FOR THURSDAY NIGHT
AND FRIDAY...WITH MOSTLY DRY WEATHER AND HIGH TEMPS AROUND 80
DEGREES FRIDAY...BUT WILL LEAVE JUST A LOW POP IN THE SOUTH AS
MODELS INDICATE SOME LINGERING MOISTURE DOWN THERE.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
A COLD FRONT PASSES ON THURSDAY. THERE IS STILL NOT GREAT MODEL
CONSENSUS...WITH THE EURO GIVING THE STRONGEST SOLUTION. FOR THE
MOST PART THE MAJOR DYNAMICS WILL BE NORTH OF THE FORECAST AREA.
HAVE INCREASED POPS WITH THE FRONT FROM WHAT WAS IN THE PREVIOUS
GRIDS. HAVE EVEN INCLUDED LIKELY OVER THE MOUNTAINS. NOT SURE HOW
QUICKLY IT WILL DRY OUT AS THE FRONT MIGHT GET HUNG UP. AT THIS
TIME WENT WITH THE PREVIOUS SCENARIO AND DRIED POPS OUT STARTING
FRIDAY.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
KEEPING WITH THE TREND OF LATE VALLEY FOG THIS MORNING LIFTING
AFTER 11-12Z.
CONVECTION SPREADING INTO THE MOUNTAINS AND SOUTHWEST TO NORTHEAST
THROUGH THE LOWLANDS TODAY AS MOISTURE INCREASES. OPTED FOR
OPTIMISTIC TAFS KEEPING THE CONVECTION OUT AND USING VCSH WHEN
POSSIBLE AS OPPOSED TO VCTS. MAY NEED TO BRING IN MORE VCTS/TSRA
FOR THE NEXT ROUTINE ISSUANCE AT 12Z THIS MORNING.
CONVECTION WILL NOT NECESSARILY WANE WITH THE LOSS OF HEATING THIS
EVENING. A SHORT WAVE TROUGH AXIS ALOFT WILL KEEP THE CHANCES FOR
SHOWERS AND STORMS GOING INTO THE OVERNIGHT TIME PERIOD.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z TUESDAY...
ALTERNATE SCENARIOS: TIMING OF RIVER VALLEY FOG COULD VARY. MAY
NEED MORE VCTS/TSRA TODAY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 08/17/15
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
CRW CONSISTENCY H H M L L L M H H H H H
HTS CONSISTENCY H H M L L L M H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H L L L L L L H H H H H
PKB CONSISTENCY H H M L L L M H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 06Z TUESDAY...
IFR CONDITIONS POSSIBLE IN AREAS OF SHOWERS AND THUNDERSTORMS WITH
THE COLD FRONT ON THURSDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JMV/26
NEAR TERM...26
SHORT TERM...JMV
LONG TERM...FB
AVIATION...26
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1156 PM CDT SUN AUG 16 2015
.AVIATION UPDATE...
FOR 06Z AVIATION.
MODELS HAVE INCREASED THEIR TREND WITH FOG ACROSS THE AREA THIS
EVENING...ESPECIALLY FOR KCKV AND KCSV. KCSV IS ALREADY SEEING VIS
DROPPING TO AROUND 7 MILES THIS EVENING. HAVE MVFR AND EVEN IFR
FOG IN FOR KCSV...AND MVFR FOR KCKV BEFORE SUNRISE. WOULD NOT BE
SURPRISED TO SEE SIMILAR CONDITIONS AS LAST NIGHT...WITH SOME LIFR
FOG POSSIBLE AS WELL. KBNA MAY SEE SOME FOG...BUT KEPT IN VFR FOR
NOW. RAIN CHANCES SHOULD INCREASE AFTER 12Z THIS MORNING FOR ALL
TERMINALS...WITH PRECIP CHANCES CONTINUING INTO THE AFTERNOON.
KCSV HAS A BETTER CHANCE FOR PRECIP DURING THE DAY TOMORROW
COMPARED TO THE OTHER TERMINALS...BUT PRECIP CHANCES WILL REMAIN
IN THE FORECAST FOR THE DURATION OF THE TAF PERIOD.
&&
.PREV DISCUSSION... /ISSUED 847 PM CDT SUN AUG 16 2015/
EVENING UPDATE...
CONVECTION HAS SINCE WANED ACROSS MIDDLE TN AND WEAKENED FURTHER
SOUTH ACROSS ALABAMA. THE UPPER LOW OVERHEAD WILL RETROGRADE A
LITTLE TO THE NORTHWEST THROUGH TOMORROW...SO MOISTURE SHOULD
STILL DRAW NORTHWARD OVERNIGHT. WILL INCREASE SLIGHT-LOW CHC POPS
THROUGH DAWN FROM THE SOUTH TO THE NORTH. THE LATEST HRRR AND NAM
GENERATE QUITE A BIT OF PRECIP AROUND 12Z SO WILL TREND THAT WAY.
WILL INCLUDE LIGHT FOG OVER NNERN AREAS AS WELL.
TEMPS LOOK ON TRACK FOR THE MOST PART. TRENDED A TAD WARMER WITH
CLOUDS INCREASING FROM THE SOUTH THOUGH.
NO OTHER CHANGES MADE. UPDATE OUT SHORTLY.
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
06
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
255 PM CDT MON AUG 17 2015
.SHORT TERM (TONIGHT THROUGH TUESDAY)...
NO MAJOR HIGHLIGHTS THROUGH TUESDAY WITH NEAR NORMAL CONDITIONS
AND LOW END RAIN CHANCES FOR THE COASTAL PLAINS.
WATER VAPOR AND RUC ANALYSIS REVEAL A SHEAR AXIS AND MID TO UPPER
LEVEL LOW ACROSS THE MID MISSISSIPPI VALLEY EXTENDING SOUTHWEST
ALONG THE TEXAS COAST. THIS FEATURE ALONG WITH AFTERNOON
INSTABILITY WILL GOVERN THE WEATHER PATTERN THROUGH
TUESDAY BY KEEPING TEMPERATURES NEAR NORMAL AND ONLY 20-30%
TSTORM CHANCES ALONG THE COAST WHERE THE SEA-BREEZE CONVERGENCE
WILL BE MORE ACTIVE. PRECIPITABLE WATER AMOUNTS CURRENTLY RANGE
FROM 1.0" TO 1.6" FROM THE RIO GRANDE VALLEY TOWARDS THE COASTAL
PLAINS. THESE VALUES ARE ABOUT 0.5 TO 1 STANDARD DEVIATION BELOW
NORMAL AND THUS RESULTING IN LIMITED SHOWER/STORM ACTIVITY ACROSS
A MAJORITY OF THE REGION. THIS PATTERN WILL CONTINUE THROUGH
TOMORROW WITH ONLY LIMITED SHOWERS AND A FEW THUNDERSTORMS ALONG
THE COASTAL PLAINS.
&&
.LONG TERM (WEDNESDAY THROUGH MONDAY)...
THE LOW-LEVEL PATTERN WILL CHANGE UP MID TO LATE WEEK AS A
BOUNDARY APPROACHES THE REGION FROM THE NORTH WITH HIGHER RAIN
CHANCES AND LOWER MAX HIGH TEMPERATURES LIKELY.
BY MID-WEEK...GLOBAL MODELS AGREE THAT A LARGE LONG WAVE TROUGH
WILL DEVELOP OVER THE CENTRAL CONUS AND WITH ADDITIONAL SHORTWAVE
TROUGH SUPPORT OVER NEW MEXICO AND TEXAS...A PSEUDO COLD FRONT
WILL APPROACH THE REGION FROM THE NORTH LATE WEDNESDAY INTO
THURSDAY MORNING. WEDNESDAY WILL REMAIN NEAR NORMAL TEMPERATURE
WISE WITH HIGHS STILL IN THE MID TO UPPER 90S AREA WIDE AND LOWER
RAIN CHANCES OF 20-40% AREA WIDE. RAIN CHANCES WILL INCREASE GOING
THROUGH THE OVERNIGHT INTO THURSDAY MORNING FOR THE HILL COUNTRY
AS THE BOUNDARY APPROACHES BUT THEN LOOKS TO STALL. WITH THE
SHEAR AXIS OVER TOP OF THE FRONT...THIS SET-UP SHOULD PROVIDE
AREAS WITH MORE CLOUDS AND WITH PWATS INCREASING TO 1.4" TO
1.8"...MORE WIDESPREAD RAIN CHANCES OF AT LEAST 50% APPEAR A
NOMINAL ROUTE TO GO FOR THURSDAY AND CONTINUING INTO FRIDAY. 12Z
GFS APPEARS TO HAVE A MESOSCALE FEEDBACK ISSUE BY PRODUCING A QPF
BULLSEYE JUST SOUTH OF THE REGION AS IT CONSOLIDATES THE UPPER LOW
INTO A TIGHTER CLOSED LOW. SINCE THIS IS THE FIRST ADVERTISEMENT
OF THIS EVOLUTION...WILL SIDE MORE WITH CONSISTANCY AND THE EC
WHICH ALSO LINGERS THE MID LEVEL ENERGY OVER THE REGION. THE EXTRA
CLOUDS SHOULD RESULT IN MAX HIGHS BEING REDUCED TO LOW TO MID 90S
BEING QUITE PLAUSIBLE.
OVER THE WEEKEND...RAIN CHANCES LOOK TO DECREASE AS THE FRONT
WASHES OUT AND SHIFTS NORTH WITH A SUBTROPICAL RIDGE SLOWLY
INCREASING ITS INFLUENCE ACROSS THE NORTH GULF.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 76 98 77 98 76 / 10 10 10 20 50
AUSTIN BERGSTROM INTL AIRPORT 72 97 74 97 74 / 10 10 10 20 50
NEW BRAUNFELS MUNI AIRPORT 75 98 76 99 76 / 10 10 10 20 40
BURNET MUNI AIRPORT 74 97 75 96 74 / 0 - - 20 50
DEL RIO INTL AIRPORT 76 100 77 100 78 / 0 0 - 20 30
GEORGETOWN MUNI AIRPORT 75 98 77 98 75 / 10 10 10 20 50
HONDO MUNI AIRPORT 73 97 74 98 76 / - - - 20 30
SAN MARCOS MUNI AIRPORT 75 97 77 97 76 / 10 10 10 20 40
LA GRANGE - FAYETTE REGIONAL 75 98 78 98 76 / 20 20 20 30 40
SAN ANTONIO INTL AIRPORT 77 97 78 97 78 / 10 - - 20 40
STINSON MUNI AIRPORT 76 99 77 99 78 / 10 10 10 20 30
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...09
SYNOPTIC/GRIDS...ALLEN
PUBLIC SERVICE/DATA COLLECTION...30
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1235 PM CDT MON AUG 17 2015
.DISCUSSION...UPDATE FOR 18Z AVIATION.
&&
.AVIATION...CONVECTION WILL BE PRIMARY WX THREAT TO AVIATION
INTERESTS THIS AFTN. SCT CONVECTION XPCTD TO CONTINUE TO DVLP
VCNTY KCRP/KVCT/KALI THRU MID AFTN WITH BRIEF MFR/IFR VSBYS LIKELY
IF CONVECTION MOVES OVER TERMINALS. VFR CONDITIONS WILL PREVAIL
AWAY FROM CONVECTION. CONVECTION MAY APPROACH KLRD LATE THIS AFTN
BUT CONFIDENCE IS LOWER IN PRECIP FALLING AT TERMINAL.
OVERNIGHT...CONVECTIVE DEBRIS CI WILL DSIPT THIS EVENING WITH
MAINLY CLEAR SKIES THRU LATE EVENING. OVERNIGHT...PATCHES OF
STRATUS SHOULD DVLP AND MAY BRIEFLY DRIFT OVER TERMINALS WITH MVFR
CONDITIONS. SCT CU FIELD TO THEN REDVLP TUES MRNG. LIGHT VRB WINDS
EARLY THIS AFTN BCMG MORE SERLY AROUND 10 TO 15 KTS AFTER
SEABREEZE PUSHES THROUGH. HOWEVER...WIND SPEEDS MAY BECOME
VARIABLE FOR BRIEF TIMES FROM CONVECTIVE OUTFLOW BOUNDARIES THIS
AFTN.
&&
.PREV DISCUSSION... /ISSUED 1115 AM CDT MON AUG 17 2015/
DISCUSSION...ENOUGH DIURNAL HEATING HAS OCCURRED TO ALLOW FOR
SCATTERED SHOWERS TO DEVELOP ACROSS THE COASTAL COUNTIES LATE THIS
MORNING AND UAH GOES-R EAST CONVECTIVE INITIATION PROBABILITY
IMAGERY INDICATES FURTHER DEVELOPMENT IS LIKELY ACROSS THE COASTAL
BEND BY EARLY AFTERNOON...AND THUS HAVE ADJUSTED POPS ACCORDINGLY.
FARTHER INLAND...CONVECTIVE ACTIVITY WILL LIKELY BE DELAYED UNTIL
MID/LATE AFTERNOON AS CONVECTIVE TEMPS ARE REACHED AND DEEPER
MOISTURE ARRIVES /ALONG WITH BETTER LLVL MOISTURE CONVERGENCE/.
HAVE EXPANDED AREAL COVERAGE OF POPS FARTHER WEST AND INCREASED
POPS A CATEGORY ACROSS MUCH OF THE BRUSH COUNTRY /ESPECIALLY
SOUTHERN BRUSH COUNTRY/ AS LATEST RAP AND 12Z NAM/CMC AND 00Z
ECMWF INDICATE SLIGHTLY BETTER /ALBEIT STILL WEAK/ UPPER LEVEL
SUPPORT MAY EXIST.
AN ISOLATED TROPICAL FUNNEL MAY OCCUR WITH TOWERING CU/CONVECTION
ACROSS THE COASTAL COUNTIES THROUGH EARLY AFTERNOON GIVEN WEAK
LOW LEVEL WIND FIELD /OCCURRENCE WOULD BE GREATER IF LLVL WIND
FIELD WAS A LITTLE MORE EASTERLY/. ALSO INTRODUCED POSSIBILITY OF
AN ISOLATED WATERSPOUT TODAY FOR MARINE AREAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 95 77 94 79 93 / 20 20 20 20 40
VICTORIA 94 75 95 76 94 / 40 20 30 30 50
LAREDO 100 78 101 78 102 / 20 20 10 10 20
ALICE 98 74 97 77 97 / 40 10 20 10 30
ROCKPORT 93 79 91 81 92 / 40 20 30 40 40
COTULLA 99 76 100 76 100 / 20 20 10 10 20
KINGSVILLE 97 75 96 77 95 / 30 10 20 20 30
NAVY CORPUS 91 79 91 81 90 / 20 20 30 30 40
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
RH/79...AVIATION
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1115 AM CDT MON AUG 17 2015
.DISCUSSION...ENOUGH DIURNAL HEATING HAS OCCURRED TO ALLOW FOR
SCATTERED SHOWERS TO DEVELOP ACROSS THE COASTAL COUNTIES LATE THIS
MORNING AND UAH GOES-R EAST CONVECTIVE INITIATION PROBABILITY
IMAGERY INDICATES FURTHER DEVELOPMENT IS LIKELY ACROSS THE COASTAL
BEND BY EARLY AFTERNOON...AND THUS HAVE ADJUSTED POPS ACCORDINGLY.
FARTHER INLAND...CONVECTIVE ACTIVITY WILL LIKELY BE DELAYED UNTIL
MID/LATE AFTERNOON AS CONVECTIVE TEMPS ARE REACHED AND DEEPER
MOISTURE ARRIVES /ALONG WITH BETTER LLVL MOISTURE CONVERGENCE/.
HAVE EXPANDED AREAL COVERAGE OF POPS FARTHER WEST AND INCREASED
POPS A CATEGORY ACROSS MUCH OF THE BRUSH COUNTRY /ESPECIALLY
SOUTHERN BRUSH COUNTRY/ AS LATEST RAP AND 12Z NAM/CMC AND 00Z
ECMWF INDICATE SLIGHTLY BETTER /ALBEIT STILL WEAK/ UPPER LEVEL
SUPPORT MAY EXIST.
AN ISOLATED TROPICAL FUNNEL MAY OCCUR WITH TOWERING CU/CONVECTION
ACROSS THE COASTAL COUNTIES THROUGH EARLY AFTERNOON GIVEN WEAK
LOW LEVEL WIND FIELD /OCCURRENCE WOULD BE GREATER IF LLVL WIND
FIELD WAS A LITTLE MORE EASTERLY/. ALSO INTRODUCED POSSIBILITY OF
AN ISOLATED WATERSPOUT TODAY FOR MARINE AREAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 95 77 94 79 93 / 20 20 20 20 40
VICTORIA 94 75 95 76 94 / 40 20 30 30 50
LAREDO 100 78 101 78 102 / 20 20 10 10 20
ALICE 98 74 97 77 97 / 40 10 20 10 30
ROCKPORT 93 79 91 81 92 / 40 20 30 40 40
COTULLA 99 76 100 76 100 / 20 20 10 10 20
KINGSVILLE 97 75 96 77 95 / 30 10 20 20 30
NAVY CORPUS 91 79 91 81 90 / 20 20 30 30 40
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
UPDATE...HART/79
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1024 PM CDT TUE AUG 18 2015
.UPDATE...SFC LOW VCNTY SW MN WITH 3 HR PRES FALLS SENDING THE LOW
TOWARDS NW WI. MAIN AREA OF SHRA/TSRA CONTINUES TO WIND DOWN.
MID LEVEL DRYING STARTING TO WRAP IN FROM FAR WRN WI/ERN IA.
HOWEVER MORE SHRA/ISOLD T STILL DVLPG ALONG THE COLD FRONT IN
CNTRL IA. MESO MODELS SHOW THIS ACTIVITY COMING IN A BIT LATER IN
THE NIGHT SO WILL MAINTAIN SOME POPS...BUT NOT EXPECTING ANY SVR
WX WITH THIS NEXT ROUND. AS SFC LOW STRENGTHENS AND PULLS NORTH
OF THE AREA ON WEDNESDAY DRAGGING COLD FRONT THROUGH IN THE
MORNING. EXPECT COOLER AND DRIER AIR TO FILTER IN AIDED BY GUSTY
SW WINDS.
PC
&&
.AVIATION/06Z TAFS/...SFC LOW ACRS SW MN MOVING NE. THIS WILL
BRING A COLD FRONT THROUGH ON WEDNESDAY MORNING...SO MORE SCT
SHRA/ISOLD T STILL EXPECTED A BIT LATER IN THE NIGHT INTO THE
EARLY MORNING HOURS UNTIL THE COLD FRONT PASSES. MAIN STORY WILL
BE THE GUSTY SW WINDS THAT DEVELOP WITH THE TIGHT GRADIENT AROUND
THE SFC LOW TO THE NORTH. ALSO LLVL RH PROGS SHOW SOME MVFR CLOUD
COVER MAY START TO WORK INTO THE AREA WITH INCREASING 850 CAA.
SREF CIG/VIS PROGS SHOW HIGHER LIKELIHOOD OF THE LOWER CIGS IN THE
WRN 2/3RDS OF THE CWA WITH AN EXPANSION ACROSS ALL OF SRN WI FOR
WED NGT.
PC
&&
.MARINE...SMALL CRAFT ADVISORY FOR LATER TONIGHT INTO THURSDAY
STILL LOOKS ON TRACK AS TIGHT PRESSURE GRADIENT WILL LEAD TO
GUSTY SW WINDS ON WEDNESDAY WITH MORE OF A WESTERLY COMPONENT FOR
THURSDAY. SO HIGHEST WAVES TOWARDS OPEN WATERS.
PC
&&
.PREV DISCUSSION... /ISSUED 339 PM CDT TUE AUG 18 2015/
SHORT TERM...
THIS EVENING...FORECAST CONFIDENCE HIGH.
A STRENGTHENING UPPER LOW OVER THE NORTHERN PLAINS IS PRODUCING
ONGOING SHOWERS AND THUNDERSTORMS OVER MN AND IA TODAY. THERE ARE A
LOT OF CLOUDS ASSOCIATED WITH THAT AND AN 850MB WARM FRONT OVER
NORTHERN WISCONSIN. SOUTHEAST WI IS SEEING A FEW BREAKS IN THE
CLOUDS TODAY WHICH IS HELPING TO INCREASE TEMPS TO AROUND 80 AND
BUILD CAPE TO AROUND 1000 J/KG.
A STRONG SHORTWAVE TROUGH CURRENTLY OVER NORTHEAST MO WILL MOVE UP
THROUGH IA AND WI LATE THIS AFTERNOON/EVENING. THE NOSE OF THE LOW
LEVEL JET /LLJ/ WILL LIFT UP TO THE WI/IL BORDER THIS AFTERNOON AND
LIKELY INTO SOUTH CENTRAL WI BEFORE SHIFTING EAST THIS EVENING. THE
CONVECTION OVER FAR WESTERN WI AND FAR EASTERN IOWA IS TRACKING NNE.
THE 19Z HRRR MODEL PICKED UP ON IT AND BRINGS A WEAKER VERSION OF IT
INTO MADISON AFTER 5 PM. IT STILL HAS THE MAIN CONVECTIVE LINE WITH
THE STRONG SHORTWAVE REACHING MADISON AROUND 01Z /8 PM. WE CANNOT
DISCOUNT THIS LATEST RUN AS IT MAY BE ON TO SOMETHING FOR HOW THIS
EVENING/S CONVECTION WILL EVOLVE.
A NW TO SE ORIENTED LINE OF THUNDERSTORMS IS PORTRAYED BY THE OTHER
CONVECTIVE ALLOWING MODELS /CAMS/. THEY LIFT IT NORTHEAST THROUGH
SOUTHERN AND EAST CENTRAL WI THIS EVENING. IT SHOULD REACH MADISON
BY 7 PM AND MILWAUKEE BY 9 PM. THE THUNDERSTORMS SHOULD BE OUT OF
SOUTHERN WI BY MIDNIGHT.
THE SHEAR WILL BE STRONG OVER SOUTH CENTRAL WI AS THE SHORTWAVE
ARRIVES. THE CAPE IS MODERATE NOW... BUT WILL BE LOWER THIS EVENING
DUE TO WARM AIR ADVECTION ALOFT AND SUBSEQUENT VERY WEAK MID LEVEL
LAPSE RATES. STILL... THERE MAY BE ENOUGH SHEAR TO DEVELOP A FEW
SUSTAINED UPDRAFTS THAT COULD PRODUCE LOW LEVEL MESOCYCLONES AND A
POSSIBLE TORNADO. THE TORNADO WATCH WAS ISSUED ALREADY THIS
AFTERNOON AND IT IS IN EFFECT UNTIL 10 PM FOR ALL BUT THE EASTERN
FORECAST AREA. THE MAIN THREAT FOR SEVERE STORMS IN SOUTH CENTRAL WI
IS NOT UNTIL AFTER 5 PM.
OVERNIGHT AND WEDNESDAY...FORECAST CONFIDENCE HIGH.
THE SURFACE LOW WILL TRACK NORTH FROM WEST CENTRAL WI TO WESTERN
LAKE SUPERIOR ON WEDNESDAY. THIS WILL RESULT IN A STRONG PRESSURE
GRADIENT OVER SOUTHERN WISCONSIN AND GUSTY SOUTHWEST WINDS BEGINNING
EARLY WEDNESDAY MORNING. STEEP LOW LEVEL LAPSE RATES WILL LEAD TO
EXTENSIVE DIURNAL CUMULUS CLOUDS SO KEPT MAX TEMPS ON THE LOWER END
OF GUIDANCE.
WEDNESDAY NIGHT AND THURSDAY...FORECAST CONFIDENCE...HIGH
THE GFS BRINGS A CLOSED MID/UPPER LOW ACROSS LAKE SUPERIOR
WEDNESDAY NIGHT AS THE TROUGH AXIS EXITS FAR EASTERN WISCONSIN
TOWARDS SUNRISE. THE CLOSED LOW LIFTS INTO SOUTHERN CANADA
THURSDAY.
THE 850/700 MB RH INCREASES OVER SOUTH CENTRAL WISCONSIN EARLY
WEDNESDAY EVENING...AND OVER MUCH OF THE SOUTH WEDNESDAY NIGHT
WITH THE EDGE OF THE HIGHER RH NEAR THE ILLINOIS BORDER AREA. THIS
SHOULD BRING AN AREA OF CUMULUS/STRATOCUMULUS ACROSS MUCH OF THE
FORECAST AREA WEDNESDAY NIGHT THAT LIFTS NORTHEAST LASTER
THURSDAY.
THE WRAP AROUND PRECIPITATION MAINLY STAYS NORTHWEST OF THE
FORECAST AREA. HOWEVER LOW LEVEL LAPSE RATES ARE FAIRLY STEEP SO
AN ISLOATED SHOWER COULD FORM THURSDAY.
WEST WINDS WILL BE BRISK AND WITH THE STEEP LAPSE RATES...GUSTS
TO 30 MPH IS POSSIBLE.
THURSDAY NIGHT AND FRIDAY...FORECAST CONFIDENCE...HIGH
A ZONAL FLOW AGAIN BRIEFLY DEVELOPS IN THE MID/UPPER LEVELS
ACROSS WISCONSIN WITH THE MAIN JET ACROSS SOUTHERN CANADA. ANOTHER
SHORTWAVE DROPS INTO THE NORTHERN ROCKIES LATE FRIDAY.
THE NAM...GFS AND ECMWF ARE DRY.
LONG TERM...
FRIDAY NIGHT AND SATURDAY...FORECAST CONFIDENCE...HIGH
THE MID/UPPER TROUGH EXITS THE NORTHERN ROCKIES AND MOVES INTO THE
NORTHERN PLAINS WITH A WEAK RIDGE OVER SOUTHERN WISCONSIN.
BOTH THE 12Z GFS AND 00Z ECMWF KEEP A LOW OVER THE PLAINS WITH
PRECIPITATION STILL WELL OFF TO THE WEST.
SUNDAY...FORECAST CONFIDENCE...MEDIUM
THE SHORTWAVE REACHES THE UPPER MISSISSIPPI VALLEY SUNDAY. THE
GFS IS JUST A LITTLE FARTHER NORTH AND SLIGHTLY SLOWER WITH THE
SHORTWAVE.
THE SURFACE LOW MOVES TO JUST NORTH OF LAKE SUPERIOR WITH A BAND
OF MODERATE PRECIPITATION WITH A TRAILING COLD FRONT.
MONDAY...FORECAST CONFIDENCE...MEDIUM
THE SHORTWAVE MOVES ACROSS THE UPPER GREAT LAKES SUNDAY NIGHT AND
PUSHES IT NORTHEAST. THE 00Z ECMWF CUTS OFF THE LOW NEAR LAKE
SUPERIOR AND LAGS THE TROUGH INTO THE GREAT LAKES INTO MONDAY.
THE 00Z ECMWF HAS LOW PRESSURE REMAINING OVER THE UPPER GREAT
LAKES INTO MONDAY WITH THE HIGH OVER THE EASTERN PLAINS AND
WESTERN MISSISSIPPI VALLEY AREA...WHILE THE GFS BRINGS THE HIGH
ACROSS WISCONSIN.
AVIATION/00Z TAFS/...
EXPECT A NW TO SE ORIENTED LINE OF THUNDERSTORMS TO LIFT NORTHEAST
THROUGH SOUTHERN WI THIS EVENING. IT SHOULD ARRIVE IN MSN BY 6 PM
AND MKE BY 8 PM. THUNDERSTORMS COULD CONTAIN STRONG WIND GUSTS AND
SMALL HAIL. THERE IS ALSO A RISK FOR A TORNADO IN SOUTH CENTRAL WI.
ALL CONVECTION SHOULD BE OUT OF SOUTHERN WI BY MIDNIGHT. LOW CIGS
ARE POSSIBLE OVERNIGHT. EXPECT GUSTY SOUTHWEST WINDS ON WEDNESDAY AS
STRONG LOW PRESSURE TRACKS ACROSS NORTHWEST WI.
MARINE...
LOW PRESSURE WILL TRACK FROM WEST CENTRAL WISCONSIN TO WESTERN LAKE
SUPERIOR ON WEDNESDAY. EXPECT GUSTY SOUTHWEST WINDS BEGINNING EARLY
WEDNESDAY MORNING THAT CONTINUE THROUGH THURSDAY AFTERNOON. A SMALL
CRAFT ADVISORY IS IN EFFECT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 4 AM WEDNESDAY TO 7 PM CDT THURSDAY
FOR LMZ643>646.
&&
$$
TONIGHT/WEDNESDAY AND AVIATION/MARINE...MRC
WEDNESDAY NIGHT THROUGH TUESDAY...HENTZ
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
335 PM CDT MON AUG 17 2015
.SHORT TERM...
.LATE THIS AFTERNOON AND EARLY EVENING...FORECAST CONFIDENCE IS
MEDIUM.
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS CURRENTLY ARE
SHIFTING SLOWLY NORTHEASTWARD ACROSS THE AREA...ALONG AND AHEAD OF A
WEAK COLD FRONT. THE PRECIPITATION WAS BEING FED BY UPPER DIVERGENCE
FROM A RIGHT REAR ENTRANCE REGION OF A 250 MB JET STREAK. THERE WAS
ALSO SOME 700 MB MOISTURE AND CYCLONIC VORTICITY ADVECTION IN THIS
AREA.
THE UPPER DIVERGENCE IS EXPECTED TO SHIFT EASTWARD ACROSS THE AREA
LATE THIS AFTERNOON INTO EARLY EVENING...AS THE SURFACE COLD FRONT
SLOWLY STALLS ACROSS OR JUST SOUTH OF THE AREA. BEST MESOSCALE
MODELS HAVE BEEN THE HRRR AND EXPERIMENTAL HRRR MODELS...WHICH HAVE
BEEN SLOW THEMSELVES TO INITIATE THE CURRENT CONVECTION. THEY HAVE
THIS ACTIVITY SLIDING OFF TO THE EAST OF THE AREA BY EARLY THIS
EVENING. FOLLOWED THIS TREND WITH THE HIGH END POPS INTO EARLY
EVENING.
SMALL HAIL AND GUSTY WINDS TO AROUND 40 MPH ARE MAINLY EXPECTED WITH
THE STRONGER STORMS...AS DEEP LAYER SHEAR AND MID LEVEL LAPSE RATES
REMAIN RATHER WEAK. AN ISOLATED SEVERE STORM IS POSSIBLE...GIVEN
DECENT 0 TO 3 KM AND MEAN LAYER CAPES ACROSS THE AREA.
.REST OF TONIGHT INTO TUESDAY...FORECAST CONFIDENCE IS MEDIUM.
MORE UNCERTAINTY WITH REGARDS TO POPS FOR LATER THIS EVENING INTO
TUESDAY MORNING. FRONTAL BOUNDARY SHOULD STALL ACROSS OR JUST SOUTH
OF THE AREA. 500 MB VORTICITY MAXIMUM DOES SHIFT THROUGH THE AREA
LATER TONIGHT...WHICH MAY BRING SOME UPWARD MOTION. THE MESOSCALE
MODELS TRY TO BRING IN SOME SHOWERS/STORMS FROM THE SOUTHWEST WITH
THIS FEATURE. KEPT CHANCE POPS FOR COLLABORATION SAKE FOR NOW...BUT
IT MAY END UP DRIER THAN FORECAST.
SHOULD SEE FOG AND SOME LOW STRATUS DEVELOP ACROSS THE AREA LATER
THIS EVENING INTO TUESDAY MORNING...WITH LIGHT WINDS AND MOIST LOW
LEVELS. DENSE FOG IS NOT ANTICIPATED...THOUGH COULD SEE IT IN LOW
LYING AREAS AS WINDS ABOVE THE WEAK INVERSION WEAKEN. THIS WILL HAVE
TO BE WATCHED BY LATER SHIFTS.
BETTER POPS RETURN TUESDAY AFTERNOON...AS FRONT BEGINS TO MOVE
NORTHWARD AS A WARM FRONT. ANOTHER 500 MB VORTICITY MAXIMUM
APPROACHES THE AREA LATER IN THE DAY...ALONG WITH AN INCREASING LOW
LEVEL JET. DEEP LAYER SHEAR REMAINS WEAK IN THE AFTERNOON...WITH
MODEST MEAN LAYER CAPES. SO...THINK SEVERE RISK IS MINIMAL IN THE
AFTERNOON PERIOD.
.TUESDAY NIGHT AND WEDNESDAY...FORECAST CONFIDENCE...MEDIUM
THE GFS MOVES THE STRONG MID/UPPER TROUGH INTO THE UPPER
MISSISSIPPI VALLEY WEDNESDAY. THE UPPER FLOW IS DIFFLUENT TUESDAY
NIGHT AHEAD OF THE TROUGH AND APPROACHING JET. AS THE 250 MB
UPPER JET ROUNDS THE BASE OF THE TROUGH AND LIFTS ACROSS WISCONSIN
IT INCREASES TO 115 KNOTS. THE UPPER DIVERGENCE AND 700 MB UPWARD
MOTION IS STRONGEST TUESDAY NIGHT...BUT WEAKER UPWARD MOTION
CONTINUES INTO THE EARLY AFTERNOON OVER SOUTHEAST WISCONSIN. 700
MB LEVELS ARE NEAR SATURATION TUESDAY NIGHT WITH THE MID LEVEL
DRYING WEDNESDAY MORNING. THE FAR SOUTHEAST IS STILL NEAR THE 700
MB MOISTURE INTO THE AFTERNOON. A 40 KNOT 700 MB SPEED MAX PUSHES
INTO THE SOUTHWEST TUESDAY NIGHT...WITH THE 55 KNOT CORE OVER
SOUTHERN WISCONSIN AROUND NOON WEDNESDAY.
THE 850 MB THERMAL RIDGE IS INTO SOUTHERN WISCONSIN LATE TUESDAY
NIGHT AND REMAINS NEAR KENOSHA WEDNESDAY AFTERNOON. COLD AIR
ADVECTION OCCURS OVER SOUTH CENTRAL WISCONSIN WEDNESDAY
MORNING...AND ACROSS THE SOUTHEAST BY NOON. THE RIBBON OF 850 MB
MOISTURE IS ACROSS MOST OF THE FORECAST AREA BY SUNRISE WEDNESDAY
WITH DRYING FROM THE WEST REACHING LAKE MICHIGAN BY NOON.
SHOWERS AND THUNDERSTORMS OCCUR OVER MUCH OF THE AREA TUESDAY
NIGHT AND BECOMES MORE OF A LINE AS THEY STRENGTHEN AGAIN OVER
SOUTHEAST WISCONSIN WEDNESDAY MORNING. BY WEDNESDAY AFTERNOON THE
PRECIPITATION IF ALL TO THE NORTH AND EAST AS THE MID AND THEN LOW
LEVEL DRYING TAKES OVER.
ZERO TO 1 KM CAPE IS AROUND 500 JOULES/KG TUESDAY NIGHT AND NEAR
800 JOULES/KG OVER THE FAR EAST BY MID MORNING. TIMING FOR THE
SEVERE POTENTIAL IS POOR...BUT SOME SEVERE POTENTIAL IS THERE
TUESDAY NIGHT. THE MODELS HAVE TRENDED A LITTLE SLOWER...AND ANY
MORE DELAY WOULD INCREASE THE RISK...OVER THE EAST ON WEDNESDAY.
.WEDNESDAY NIGHT AND THURSDAY...FORECAST CONFIDENCE...MEDIUM
THE GFS BRINGS A CLOSED MID/UPPER LOW NEAR DULUTH WEDNESDAY NIGHT
BEFORE LIFTING INTO SOUTHERN CANADA THURSDAY. BOTH THE 12Z NAM AND
00Z ECMWF IS A LITTLE QUICKER...AND NOT AS STRONG WITH THE LOW.
THE 850/700 MB RH INCREASES OVER SOUTH CENTRAL WISCONSIN EARLY
WEDNESDAY EVENING...AND OVER MUCH OF THE SOUTH WEDNESDAY NIGHT
WITH THE EDGE OF THE HIGHER RH NEAR THE ILLINOIS BORDER AREA.
THE WRAP AROUND PRECIPITATION STAYS NORTHWEST OF THE FORECAST
AREA...BUT THE GFS DOES BRUSH NORTHWEST SAUK COUNTY BRIEFLY
WEDNESDAY NIGHT.
THE 850/700 MB RH LIFTS NORTH DURING THE DAY THURSDAY. WEST
WINDS WILL BE BRISK.
.LONG TERM...
.THURSDAY NIGHT AND FRIDAY...FORECAST CONFIDENCE...MEDIUM
A ZONAL FLOW AGAIN BRIEFLY DEVELOPS IN THE MID/UPPER LEVELS
ACROSS WISCONSIN WITH ANOTHER SHORTWAVE MOVING TOWARD THE NORTHERN
ROCKIES FRIDAY. THE GFS IS A LITTLE SLOWER WITH THIS.
BOTH THE GFS AND ECMWF ARE MAINLY DRY.
.FRIDAY NIGHT AND SATURDAY...FORECAST CONFIDENCE...MEDIUM
THE MID/UPPER TROUGH EXITS THE NORTHERN ROCKIES AND MOVES INTO THE
NORTHERN PLAINS WITH A WEAK RIDGE OVER WISCONSIN.
BOTH THE 12Z GFS AND 00Z ECMWF KEEP A LOW OVER THE PLAINS WITH
SOME PRECIPITATION JUST APPROACHING THE FORECAST AREA.
.SUNDAY...FORECAST CONFIDENCE...MEDIUM
THE SHORTWAVE REACHES THE UPPER MISSISSIPPI VALLEY SUNDAY. THE
GFS IS JUST A LITTLE FARTHER NORTH AND SLOWER WITH THE SHORTWAVE.
THE SURFACE TROUGH MOVES INTO THE UPPER GREAT LAKES ALONG WITH A
BAND OF MODERATE PRECIPITATION WITH A TRAILING COLD FRONT.
.MONDAY...FORECAST CONFIDENCE...MEDIUM
THE SHORTWAVE MOVES ACROSS THE UPPER GREAT LAKES.
THE 00Z ECMWF HAS SOME LIGHT PRECIPITATION WITH THE LINGERING
UPPER LOW...MAINLY NORTH AREAS...WHILE THE GFS IS DRY ON MONDAY AS
HIGH PRESSURE APPROACHES FROM THE PLAINS.
&&
.AVIATION/00Z TAFS/...
A WEAK COLD FRONT WILL STALL AROUND OR JUST SOUTH OF THE AREA LATE
THIS AFTERNOON AND TONIGHT. SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS ARE EXPECTED INTO THE EARLY EVENING HOURS...BEFORE
SHIFTING OFF TO THE EAST. SMALL HAIL AND GUSTS TO 40 MPH ARE
EXPECTED WITH THE STRONGER STORMS...WITH MVFR VISIBILITIES.
ENOUGH LOW LEVEL MOISTURE AND LIGHT WINDS LATER TONIGHT INTO TUESDAY
MORNING SHOULD LEAD TO IFR FOG AND SOME LOW STRATUS DEVELOPMENT
ACROSS THE AREA. KEPT THIS MENTION GOING IN TAFS.
FRONT MOVES NORTHWARD THROUGH AREA TUESDAY AS A WARM FRONT...WHICH
WILL BRING MORE CHANCES FOR SHOWERS AND STORMS. BEST CHANCES WILL BE
LATER IN THE DAY. WILL MENTION VICINITY THUNDER IN TAFS...GIVEN SOME
TIMING/AREAL COVERAGE UNCERTAINTY. SOUTHEAST WINDS SHOULD INCREASE
DURING THE DAY TUESDAY.
&&
.MARINE...
SCATTERED/NUMEROUS SHOWERS/STORMS ARE EXPECTED TO AFFECT THE
NEARSHORE WATERS OF LAKE MICHIGAN INTO THE EARLY EVENING HOURS...AS
A WEAK COLD FRONT MOVES INTO THE AREA. SMALL HAIL AND GUSTY WINDS TO
33 KNOTS ARE POSSIBLE IN THE STRONGER STORMS.
SHOULD SEE FOG DEVELOP ACROSS THE NEARSHORE WATERS OF LAKE MICHIGAN
LATER TONIGHT INTO TUESDAY MORNING...WITH LIGHT WINDS AND A MOIST
AIRMASS OVER THE REGION. NOT EXPECTING WIDESPREAD DENSE FOG AT THIS
TIME...BUT WILL NEED TO BE MONITORED BY LATER SHIFTS.
MORE SHOWERS AND STORMS ARE FORECAST BY TUESDAY AFTERNOON...WITH THE
BEST CHANCES TUESDAY NIGHT INTO EARLY WEDNESDAY...AS STRONG LOW
PRESSURE MOVES THROUGH THE REGION.
A TIGHT PRESSURE GRADIENT ON WEDNESDAY INTO THURSDAY SHOULD LEAD TO
WINDY CONDITIONS ACROSS THE NEARSHORE WATERS. WINDS SHOULD BE
OFFSHORE DURING THIS TIME. GALE FORCE GUSTS MAY BE POSSIBLE AT
TIMES...WITH A SMALL CRAFT ADVISORY LIKELY NEEDED IN LATER
FORECASTS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TONIGHT/TUESDAY AND AVIATION/MARINE...WOOD
TUESDAY NIGHT THROUGH MONDAY...HENTZ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1252 PM CDT MON AUG 17 2015
.UPDATE...
ISSUED AT 1151 AM CDT MON AUG 17 2015
HAVE BEEN UPDATING THE FORECAST WITH LITTLE TWEEKS THROUGH THE
MORNING HOURS. OVERALL...A TOUGH FORECAST TO DETAIL WITH FORCING
REALLY DIMINISHING IN THE MOIST PLUME.
RADAR ECHOS THROUGH THE AREA ARE NEAR AND JUST BEHIND THE FRONT AT
THE SURFACE WHICH IS ALONG A WEST OF KGRB-KDBQ LINE AT 16Z
SHIFTING SLOWLY EAST. INSTABILITY GROWING RAPIDLY ALONG A SHARP
LINE OF CLOUD/SUN IN CENTRAL WI AND SWRN WI. OVER THE LAST 20
MINUTES ECHOS ARE STARTING TO DEVELOP ON THE FRONT. WITH 1500-2000
J/KG MUCAPE AT 16Z AND CONTINUING TO GROW...THINKING THE FRONT
WILL GET MORE AND MORE ACTIVE WITH TSRA AS IT MOVES INTO SRN/ERN
WI TODAY. THIS WILL LEAVE THE FORECAST AREA IN A POST-FRONTAL
MOIST REGIME WITH ANY BUMP FROM FORCING CAUSING SHOWERS. 850 MB
TROUGH LAGS THE SURFACE PER 88D VWP WINDS AND IS STILL IN THE WRN
FORECAST AREA...ALBEIT WEAK CONVERGENCE...IT COULD CAUSE SHOWERS
TO POP UP. TROUGH/FRONT SHOULD LAY UP ACROSS SRN WI/NERN IA BY
LATER TODAY ALMOST E-W.
RAIN/TSRA OVER NWRN IA IS IN RESPONSE TO LOW-LEVEL E-W TROUGHING
AND GOOD LOW-LEVEL CONVERGENCE AHEAD OF A VERY APPARENT SHORTWAVE
TROUGH IN THE GOES WATER VAPOR APPROACHING OMAHA NEB. SO...HAVE
BEGUN THE IDEA THAT THE SHORTWAVE TROUGH WILL APPROACH THE AREA
THIS EVENING AND WORK WITH THE FRONT...ENHANCE LOW-LEVEL
FRONTOGENESIS...TO SPAWN MORE WIDESPREAD RAIN SHOWERS AND ISOLATED
TSRA MAINLY NEAR AND SOUTH OF I-90 AS IT SHIFTS THROUGH FROM
00-09Z. HAVE NOT UPDATED THE FORECAST YET FOR THAT EVOLUTION AS IT
NEEDS TO BE COLLABORATED WITH THE NEIGHBORING OFFICES...BUT REALLY
LIKE THE LATEST HRRR REFLECTIVITY FORECASTS AS GUIDANCE.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 348 AM CDT MON AUG 17 2015
THE COLD FRONT EXTENDED FROM NORTH CENTRAL WISCONSIN INTO
NORTHERN KANSAS EARLY THIS MORNING. REGIONAL RADARS INDICATE THE
REMAINING SHOWERS HAVE BECOME ORIENTED ALONG AND JUST BEHIND THE
FRONT WITH THE LARGEST CONCENTRATION MOVING SLOWLY NORTHEAST OUT
OF NORTHERN IOWA. THIS AREA OF SHOWERS IS ASSOCIATED WITH A WEAK
SECONDARY MOISTURE TRANSPORT AXIS THAT THE 17.06Z RAP MOVES
NORTHEAST INTO THE AREA AND THEN STARTS TO WEAKEN IT AROUND 12Z
INTO THE REST OF THE MORNING. THE 17.06Z HRRR SHOWS THESE TRENDS
WELL AND BRINGS IN THE BAND OF RAIN THROUGH ABOUT 12Z AND THEN
SHOWS IT WEAKENING AS THE MORNING PROGRESSES WITH THE WEAKENING
MOISTURE TRANSPORT.
THE FRONT WILL CONTINUE TO WORK SLOWLY SOUTH THROUGH THE REST OF
THE DAY BUT SOME UNCERTAINTY ON JUST HOW MUCH ACTIVITY WILL OCCUR
WITH IT. MOST OF THE HI-RES MESO MODELS SHOW A CONTINUED
DIMINISHING TREND INTO THE EARLY AFTERNOON WITH MAINLY SCATTERED
COVERAGE. WITH NO SHORT WAVE TROUGHS TO PROVIDE ANY DYNAMIC
SUPPORT TODAY...ANY INCREASE IN ACTIVITY WILL HAVE TO BE
THERMODYNAMICALLY DRIVEN. WITH SOME HEATING OCCURRING UNDER THE
CLOUD COVER...THE 17.00Z NAM SUGGESTS THE MU CAPE COULD INCREASE
INTO THE 1000-1500 J/KG RANGE ACROSS THE SOUTH DURING THE
AFTERNOON. THE FRONTOGENESIS IN THE 1000-850 MB LAYER ALSO SHOWS A
DIURNAL INCREASE DURING THE AFTERNOON AND THIS MAY BE ENOUGH TO
MAINTAIN SOME SCATTERED ACTIVITY ALONG THE FRONT.
DIFFERENCES AMONG THE MODELS THEN START TO SHOW UP IN HOW FAR
SOUTH THE FRONT PROGRESSES TONIGHT. THE NAM AND THE MESO MODELS
SUGGEST A GENERAL LULL IN THE ACTIVITY THIS EVENING BUT THEN START
TO BRING THE FRONT BACK LATE TONIGHT AHEAD OF THE NEXT SYSTEM.
WATER VAPOR SATELLITE THIS MORNING SHOWS THIS NEXT SHORT WAVE
TROUGH WAS OVER EASTERN WASHINGTON AND OREGON. THE GENERAL TREND
IN THE MODELS WITH THIS SYSTEM REMAINS THE SAME WITH IT
INTENSIFYING AS IT APPROACHES...FORMING A CLOSED UPPER LEVEL LOW
OVER THE EASTERN DAKOTAS TUESDAY. SOME DIFFERENCES ON HOW STRONG
THE WAVE BECOMES WITH THE 17.00Z GFS CONTINUING ITS TREND OF BEING
THE STRONGEST WITH IT AND ALSO THEN THE SLOWEST TO MOVE IT OUT.
THE UPPER LEVEL LOW AND SHORT WAVE TROUGH SHOULD THEN LIFT
NORTHEAST ACROSS MINNESOTA AND INTO CANADA TUESDAY NIGHT INTO
WEDNESDAY. THE FORCING AHEAD OF THIS WAVE WILL START TO INCREASE
LATE TONIGHT AS HEIGHT FALLS START TO SPREAD OVER THE REGION. THE
FORCING LOOKS TO BE THE STRONGEST TUESDAY NIGHT AS MODERATE PV
ADVECTION IN THE 500-300 MB LAYER MOVES ACROSS WITH THE SHORT WAVE
TROUGH. THE BEST MOISTURE TRANSPORT SHOULD STAY TO THE WEST OF THE
AREA TONIGHT BUT THERE IS SOME SUGGESTION OF A WEAK BRANCH COMING
INTO THE FRONT FOR LATE TONIGHT. THIS MOISTURE TRANSPORT THEN
CONTINUES TO INCREASE THROUGH THE DAY TUESDAY AND LOOKS TO BE
RIGHT INTO THE AREA FOR TUESDAY EVENING. BASED ON THESE SIGNALS
PLAN TO START INCREASING THE RAIN CHANCES LATE TONIGHT ACROSS THE
SOUTH WITH THE CHANCES THEN INCREASING ACROSS THE ENTIRE AREA
TUESDAY. THE HIGHEST RAIN CHANCES SHOULD OCCUR TUESDAY EVENING AS
THE FRONT MOVES BACK INTO THE AREA AS A SURFACE LOW TRACKS FROM
IOWA INTO MINNESOTA. THEN EXPECTING THE DRY SLOT TO START WORKING
IN FROM THE SOUTH FOR LATE TUESDAY NIGHT INTO WEDNESDAY AS THE
ENTIRE SYSTEM LIFTS OFF TO THE NORTH.
QUESTIONS ON JUST HOW MUCH OF A SEVERE THREAT THERE WILL BE WITH
THIS SYSTEM. EXPECTING RAIN TO BE FALLING AHEAD OF THE WARM FRONT
AND THE WARM SECTOR ITSELF TO NOT BE VERY CLEAN. THIS SHOULD LIMIT
THE AMOUNT OF INSTABILITY WITH BOTH THE NAM AND GFS SHOWING LESS
THEN 750 J/KG OF ML CAPE AVAILABLE IN THE WARM SECTOR. WITH THE
GFS BEING THE STRONGEST WITH THE SYSTEM IT PRODUCES THE MOST SHEAR
WITH 30 TO 35 KNOTS IN THE 0-3KM LAYER WHILE THE NAM STRUGGLES TO
GET 20 KNOTS IN HERE IN THE SAME LAYER. COULD SEE SOME STRONGER
STORMS DEVELOP BUT STILL NOT THINKING THERE WOULD BE MUCH IN THE
WAY OF AN ORGANZID SEVERE EVENT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 348 AM CDT MON AUG 17 2015
ANY LINGERING RAIN CHANCES FROM THIS SYSTEM SHOULD MAINLY BE
LIMITED TO THE INTERSTATE 94 CORRIDOR FOR WEDNESDAY NIGHT BEFORE
DRY WEATHER SETTLES IN FOR THURSDAY THROUGH FRIDAY. THE RAIN
CHANCES THEN LOOK LIKE THEY WILL RETURN FOR THE UPCOMING WEEKEND.
PRETTY GOOD AGREEMENT BETWEEN THE GFS AND 17.00Z ECMWF OF A COLD
FRONT SWEEPING ACROSS THE REGION SATURDAY AND SATURDAY NIGHT. THE
SHORT WAVE TROUGH WITH THIS SYSTEM LOOKS TO BE PRETTY SIMILAR TO
THE UPCOMING SYSTEM FOR TUESDAY. IT SHOULD COME IN OFF THE
NORTHERN PACIFIC AND INTENSIFY ONCE IT CROSSES THE NORTHERN
ROCKIES BUT IT MAY TRACK SLIGHTLY FARTHER TO THE NORTH ACROSS
NORTH DAKOTA OR EXTREME SOUTHERN CANADA. THIS COULD BRING IN A
DECENT ROUND OF SHOWERS AND STORMS AGAIN AS THE FRONT COMES
ACROSS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1253 PM CDT MON AUG 17 2015
FORECAST CONFIDENCE CONTINUES TO BE LOWER FOR THIS FORECAST
PACKAGE OF THE TAFS. VERY MOIST AIR MASS OVER THE AREA AND WEAK
ELEMENTS CAUSING LIFT MAKE IT A DIFFICULT FORECAST FOR DETAILS.
HAVE GONE WITH A BIT OF DRYING NORTHERLY WIND TODAY TO LIFT THE
CEILINGS FOR A PERIOD THIS AFTERNOON. VFR IS ONLY ABOUT A COUNTY
NORTH OF THE AIRFIELDS. HOWEVER THERE IS A CHANCE THAT SHOWERS
AND AN MVFR DECK WILL ROLL INTO KRST LATER THIS AFTERNOON/EVENING
ASSOCIATED WITH THE WEATHER NOW NEAR KRWF IN SWRN MN. THOSE MVFR
CIGS ARE ALREADY WEST OF KRST.
OTHERWISE...HAVE BEGUN A TREND OF MOISTENING THE LOW-LEVELS
OVERNIGHT TO BRING IN SOME LOWER CEILINGS AND FOG. DEWPOINT
DEPRESSIONS ARE WILL NOT BE MORE THAN 5-8F EARLY THIS
EVENING...PRETTY EASY TO OVERCOME.
&&
.HYDROLOGY...
ISSUED AT 348 AM CDT MON AUG 17 2015
DECENT RAINFALL AMOUNTS ARE EXPECTED WITH THE UPCOMING SYSTEM FROM
LATE TONIGHT THROUGH WEDNESDAY. CURRENTLY EXPECTING RAINFALL
AMOUNTS OF 1 TO 1.5 INCHES OVER THIS SPREAD OUT PERIOD. THESE
AMOUNTS AND THE SOMEWHAT EXTENDED TIME FRAME OVER WHICH THEY ARE
EXPECTED...SHOULD NOT BE ENOUGH TO CAUSE ANY FLOODING
PROBLEMS...ESPECIALLY GIVEN THE RECENT DRY CONDITIONS THAT HAVE
DEVELOPED. NOT ANTICIPATING THE NEED FOR ANY HYDROLOGIC HEADLINES
FROM THIS SYSTEM.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...BAUMGARDT
SHORT TERM...04
LONG TERM...04
AVIATION...BAUMGARDT
HYDROLOGY...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1151 AM CDT MON AUG 17 2015
.UPDATE...
ISSUED AT 1151 AM CDT MON AUG 17 2015
HAVE BEEN UPDATING THE FORECAST WITH LITTLE TWEEKS THROUGH THE
MORNING HOURS. OVERALL...A TOUGH FORECAST TO DETAIL WITH FORCING
REALLY DIMINISHING IN THE MOIST PLUME.
RADAR ECHOS THROUGH THE AREA ARE NEAR AND JUST BEHIND THE FRONT AT
THE SURFACE WHICH IS ALONG A WEST OF KGRB-KDBQ LINE AT 16Z
SHIFTING SLOWLY EAST. INSTABILITY GROWING RAPIDLY ALONG A SHARP
LINE OF CLOUD/SUN IN CENTRAL WI AND SWRN WI. OVER THE LAST 20
MINUTES ECHOS ARE STARTING TO DEVELOP ON THE FRONT. WITH 1500-2000
J/KG MUCAPE AT 16Z AND CONTINUING TO GROW...THINKING THE FRONT
WILL GET MORE AND MORE ACTIVE WITH TSRA AS IT MOVES INTO SRN/ERN
WI TODAY. THIS WILL LEAVE THE FORECAST AREA IN A POST-FRONTAL
MOIST REGIME WITH ANY BUMP FROM FORCING CAUSING SHOWERS. 850 MB
TROUGH LAGS THE SURFACE PETR 88D VWP WINDS AND IS STILL IN THE
WRN FORECAST AREA...ALBEIT WEAK CONVERGENCE...IT COULD CAUSE
SHOWERS TO POP UP. TROUGH/FRONT SHOULD LAY UP ACROSS SRN WI/NERN
IA BY LATER TODAY ALMOST E-W.
RAIN/TSRA OVER NWRN IA IS IN RESPONSE TO LOW-LEVEL E-W TROUGHING
AND GOOD LOW-LEVEL CONVERGENCE AHEAD OF A VERY APPARENT SHORTWAVE
TROUGH IN THE GOES WATER VAPOR APPROACHING OMAHA NEB. SO...HAVE
BEGUN THE IDEA THAT THE SHORTWAVE TROUGH WILL APPROACH THE AREA
THIS EVENING AND WORK WITH THE FRONT...ENHANCE LOW-LEVEL
FRONTOGENESIS...TO SPAWN MORE WIDESPREAD RAIN SHOWERS AND ISOLATED
TSRA MAINLY NEAR AND SOUTH OF I-90 AS IT SHIFTS THROUGH FROM
00-09Z. HAVE NOT UPDATED THE FORECAST YET FOR THAT EVOLUTION AS IT
NEEDS TO BE COLLABORATED WITH THE NEIGHBORING OFFICES...BUT REALLY
LIKE THE LATEST HRRR REFLECTIVITY FORECASTS AS GUIDANCE.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 348 AM CDT MON AUG 17 2015
THE COLD FRONT EXTENDED FROM NORTH CENTRAL WISCONSIN INTO
NORTHERN KANSAS EARLY THIS MORNING. REGIONAL RADARS INDICATE THE
REMAINING SHOWERS HAVE BECOME ORIENTED ALONG AND JUST BEHIND THE
FRONT WITH THE LARGEST CONCENTRATION MOVING SLOWLY NORTHEAST OUT
OF NORTHERN IOWA. THIS AREA OF SHOWERS IS ASSOCIATED WITH A WEAK
SECONDARY MOISTURE TRANSPORT AXIS THAT THE 17.06Z RAP MOVES
NORTHEAST INTO THE AREA AND THEN STARTS TO WEAKEN IT AROUND 12Z
INTO THE REST OF THE MORNING. THE 17.06Z HRRR SHOWS THESE TRENDS
WELL AND BRINGS IN THE BAND OF RAIN THROUGH ABOUT 12Z AND THEN
SHOWS IT WEAKENING AS THE MORNING PROGRESSES WITH THE WEAKENING
MOISTURE TRANSPORT.
THE FRONT WILL CONTINUE TO WORK SLOWLY SOUTH THROUGH THE REST OF
THE DAY BUT SOME UNCERTAINTY ON JUST HOW MUCH ACTIVITY WILL OCCUR
WITH IT. MOST OF THE HI-RES MESO MODELS SHOW A CONTINUED
DIMINISHING TREND INTO THE EARLY AFTERNOON WITH MAINLY SCATTERED
COVERAGE. WITH NO SHORT WAVE TROUGHS TO PROVIDE ANY DYNAMIC
SUPPORT TODAY...ANY INCREASE IN ACTIVITY WILL HAVE TO BE
THERMODYNAMICALLY DRIVEN. WITH SOME HEATING OCCURRING UNDER THE
CLOUD COVER...THE 17.00Z NAM SUGGESTS THE MU CAPE COULD INCREASE
INTO THE 1000-1500 J/KG RANGE ACROSS THE SOUTH DURING THE
AFTERNOON. THE FRONTOGENESIS IN THE 1000-850 MB LAYER ALSO SHOWS A
DIURNAL INCREASE DURING THE AFTERNOON AND THIS MAY BE ENOUGH TO
MAINTAIN SOME SCATTERED ACTIVITY ALONG THE FRONT.
DIFFERENCES AMONG THE MODELS THEN START TO SHOW UP IN HOW FAR
SOUTH THE FRONT PROGRESSES TONIGHT. THE NAM AND THE MESO MODELS
SUGGEST A GENERAL LULL IN THE ACTIVITY THIS EVENING BUT THEN START
TO BRING THE FRONT BACK LATE TONIGHT AHEAD OF THE NEXT SYSTEM.
WATER VAPOR SATELLITE THIS MORNING SHOWS THIS NEXT SHORT WAVE
TROUGH WAS OVER EASTERN WASHINGTON AND OREGON. THE GENERAL TREND
IN THE MODELS WITH THIS SYSTEM REMAINS THE SAME WITH IT
INTENSIFYING AS IT APPROACHES...FORMING A CLOSED UPPER LEVEL LOW
OVER THE EASTERN DAKOTAS TUESDAY. SOME DIFFERENCES ON HOW STRONG
THE WAVE BECOMES WITH THE 17.00Z GFS CONTINUING ITS TREND OF BEING
THE STRONGEST WITH IT AND ALSO THEN THE SLOWEST TO MOVE IT OUT.
THE UPPER LEVEL LOW AND SHORT WAVE TROUGH SHOULD THEN LIFT
NORTHEAST ACROSS MINNESOTA AND INTO CANADA TUESDAY NIGHT INTO
WEDNESDAY. THE FORCING AHEAD OF THIS WAVE WILL START TO INCREASE
LATE TONIGHT AS HEIGHT FALLS START TO SPREAD OVER THE REGION. THE
FORCING LOOKS TO BE THE STRONGEST TUESDAY NIGHT AS MODERATE PV
ADVECTION IN THE 500-300 MB LAYER MOVES ACROSS WITH THE SHORT WAVE
TROUGH. THE BEST MOISTURE TRANSPORT SHOULD STAY TO THE WEST OF THE
AREA TONIGHT BUT THERE IS SOME SUGGESTION OF A WEAK BRANCH COMING
INTO THE FRONT FOR LATE TONIGHT. THIS MOISTURE TRANSPORT THEN
CONTINUES TO INCREASE THROUGH THE DAY TUESDAY AND LOOKS TO BE
RIGHT INTO THE AREA FOR TUESDAY EVENING. BASED ON THESE SIGNALS
PLAN TO START INCREASING THE RAIN CHANCES LATE TONIGHT ACROSS THE
SOUTH WITH THE CHANCES THEN INCREASING ACROSS THE ENTIRE AREA
TUESDAY. THE HIGHEST RAIN CHANCES SHOULD OCCUR TUESDAY EVENING AS
THE FRONT MOVES BACK INTO THE AREA AS A SURFACE LOW TRACKS FROM
IOWA INTO MINNESOTA. THEN EXPECTING THE DRY SLOT TO START WORKING
IN FROM THE SOUTH FOR LATE TUESDAY NIGHT INTO WEDNESDAY AS THE
ENTIRE SYSTEM LIFTS OFF TO THE NORTH.
QUESTIONS ON JUST HOW MUCH OF A SEVERE THREAT THERE WILL BE WITH
THIS SYSTEM. EXPECTING RAIN TO BE FALLING AHEAD OF THE WARM FRONT
AND THE WARM SECTOR ITSELF TO NOT BE VERY CLEAN. THIS SHOULD LIMIT
THE AMOUNT OF INSTABILITY WITH BOTH THE NAM AND GFS SHOWING LESS
THEN 750 J/KG OF ML CAPE AVAILABLE IN THE WARM SECTOR. WITH THE
GFS BEING THE STRONGEST WITH THE SYSTEM IT PRODUCES THE MOST SHEAR
WITH 30 TO 35 KNOTS IN THE 0-3KM LAYER WHILE THE NAM STRUGGLES TO
GET 20 KNOTS IN HERE IN THE SAME LAYER. COULD SEE SOME STRONGER
STORMS DEVELOP BUT STILL NOT THINKING THERE WOULD BE MUCH IN THE
WAY OF AN ORGANZID SEVERE EVENT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 348 AM CDT MON AUG 17 2015
ANY LINGERING RAIN CHANCES FROM THIS SYSTEM SHOULD MAINLY BE
LIMITED TO THE INTERSTATE 94 CORRIDOR FOR WEDNESDAY NIGHT BEFORE
DRY WEATHER SETTLES IN FOR THURSDAY THROUGH FRIDAY. THE RAIN
CHANCES THEN LOOK LIKE THEY WILL RETURN FOR THE UPCOMING WEEKEND.
PRETTY GOOD AGREEMENT BETWEEN THE GFS AND 17.00Z ECMWF OF A COLD
FRONT SWEEPING ACROSS THE REGION SATURDAY AND SATURDAY NIGHT. THE
SHORT WAVE TROUGH WITH THIS SYSTEM LOOKS TO BE PRETTY SIMILAR TO
THE UPCOMING SYSTEM FOR TUESDAY. IT SHOULD COME IN OFF THE
NORTHERN PACIFIC AND INTENSIFY ONCE IT CROSSES THE NORTHERN
ROCKIES BUT IT MAY TRACK SLIGHTLY FARTHER TO THE NORTH ACROSS
NORTH DAKOTA OR EXTREME SOUTHERN CANADA. THIS COULD BRING IN A
DECENT ROUND OF SHOWERS AND STORMS AGAIN AS THE FRONT COMES
ACROSS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 659 AM CDT MON AUG 17 2015
SHOWERS AND ISOLATED THUNDERSTORMS WILL EDGE SOUTHEAST ACROSS THE
AREA THIS MORNING ALONG A WEAKENING COLD FRONT WITH PERIODS OF
MVFR TO IFR CONDITIONS POSSIBLE AT TIMES. THIS ACTIVITY WILL
GRADUALLY TAPER OFF AND SHIFT SOUTHEAST OF KRST BY LATE THIS
MORNING AND BY MID TO LATE AFTERNOON AT KLSE. CEILINGS COULD FALL
TO AROUND 400 FT UNDER THE HEAVIER SHOWERS AND THE VISIBILITY MAY
BE REDUCED TO 2 SM OR LESS. IN THE WAKE OF THE FRONT A BRIEF
PERIOD OF MVFR STRATUS IS EXPECTED THEN CEILINGS SHOULD IMPROVE TO
VFR AND STAY THERE THROUGH THE OVERNIGHT HOURS.
&&
.HYDROLOGY...
ISSUED AT 348 AM CDT MON AUG 17 2015
DECENT RAINFALL AMOUNTS ARE EXPECTED WITH THE UPCOMING SYSTEM FROM
LATE TONIGHT THROUGH WEDNESDAY. CURRENTLY EXPECTING RAINFALL
AMOUNTS OF 1 TO 1.5 INCHES OVER THIS SPREAD OUT PERIOD. THESE
AMOUNTS AND THE SOMEWHAT EXTENDED TIME FRAME OVER WHICH THEY ARE
EXPECTED...SHOULD NOT BE ENOUGH TO CAUSE ANY FLOODING
PROBLEMS...ESPECIALLY GIVEN THE RECENT DRY CONDITIONS THAT HAVE
DEVELOPED. NOT ANTICIPATING THE NEED FOR ANY HYDROLOGIC HEADLINES
FROM THIS SYSTEM.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...BAUMGARDT
SHORT TERM...04
LONG TERM...04
AVIATION...WETENKAMP
HYDROLOGY...04
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1103 AM CDT MON AUG 17 2015
.UPDATE...
AREA OF SHOWERS CURRENTLY EXTEND FROM NORTHEAST INTO SOUTHWEST
WISCONSIN...THEN TO THE WEST. THE SHOWERS WERE LOCATED BEHIND THE
SURFACE COLD FRONT...BEING FED BY UPPER DIVERGENCE FROM RIGHT REAR
ENTRANCE REGION OF 250 MB JET STREAK. THERE WAS ALSO SOME 700 MB
MOISTURE AND CYCLONIC VORTICITY ADVECTION IN THIS AREA.
THE UPPER DIVERGENCE IS EXPECTED TO SHIFT EASTWARD ACROSS THE AREA
THIS AFTERNOON...AS WELL AS THE SURFACE COLD FRONT. THERE IS NOT A
LOT OF LOW LEVEL FRONTOGENESIS RESPONSE ASSOCIATED WITH THE COLD
FRONT ITSELF. STILL LOOKS TO BE ENOUGH UPWARD VERTICAL MOTION TO
COMBINE WITH NO CAPPING TO HELP SOME SHOWERS AND THUNDERSTORMS
DEVELOP BY MIDDLE AFTERNOON AND SPREAD EAST INTO THE MIDDLE
EVENING HOURS. THIS IS SUPPORTED BY SEVERAL MESOSCALE MODELS.
AREA FORECAST SOUNDINGS ARE SHOWING WEAK DEEP LAYER SHEAR AND
WEAK TO MODEST AMOUNTS OF MEAN LAYER CAPE DURING THIS TIME...SO NO
SEVERE WEATHER IS EXPECTED. WILL KEEP LIKELY POPS GOING FOR THIS
AFTERNOON INTO THE MIDDLE EVENING HOURS. HIGH TEMPERATURES WILL BE
RAISED A FEW DEGREES IN THE CENTRAL AND EASTERN AREAS...GIVEN
CURRENT TRENDS.
&&
.AVIATION/18Z TAFS/...
A WEAK COLD FRONT WILL SHIFT SOUTHEAST INTO THE AREA THIS
AFTERNOON AND STALL AROUND OR JUST SOUTH OF THE AREA TONIGHT. AN
AREA OF SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP AND
MOVE EASTWARD WITH THE FRONT ACROSS THE AREA THIS AFTERNOON INTO
THE MIDDLE EVENING HOURS.
MAY SEE MVFR VISIBILITIES WITH ANY STORMS...ALONG WITH BRIEF
GUSTY WINDS. VFR CONDITIONS ARE EXPECTED OTHERWISE. WILL CONTINUE
WITH VICINITY AND TEMPO WORDING IN TAFS...GIVEN SOME UNCERTAINTY
WITH TIMING AND AREAL COVERAGE OF THE SHOWERS/STORMS.
ENOUGH LOW LEVEL MOISTURE AND LIGHT WINDS LATER TONIGHT INTO
TUESDAY MORNING SHOULD LEAD TO IFR FOG AND SOME LOW STRATUS
DEVELOPMENT ACROSS THE AREA. KEPT MENTION GOING IN TAFS.
FRONT MOVES BACK INTO THE AREA TUESDAY AS A WARM FRONT...WHICH
WILL BRING MORE CHANCES FOR SHOWERS AND STORMS. BEST CHANCES WILL
BE LATER IN THE DAY WITH DAYTIME HEATING. WILL MENTION VICINITY
THUNDER IN TAFS GIVEN SOME TIMING/AREAL COVERAGE UNCERTAINTY.
&&
.MARINE...
SOME SHOWERS/STORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON AND
LINGER INTO THE MIDDLE EVENING HOURS...AS A COLD FRONT SLIDES
SOUTHEAST INTO THE AREA.
SHOULD SEE FOG DEVELOP ACROSS THE NEARSHORE WATERS OF LAKE
MICHIGAN LATER TONIGHT INTO TUESDAY MORNING...WITH LIGHT WINDS AND
A MOIST AIRMASS OVER THE REGION. NOT EXPECTING WIDESPREAD DENSE
FOG AT THIS TIME...BUT PATCHY DENSE FOG IS POSSIBLE.
A TIGHT PRESSURE GRADIENT ON WEDNESDAY SHOULD LEAD TO WINDY
CONDITIONS ACROSS THE NEARSHORE WATERS. WINDS SHOULD BE OFFSHORE
DURING THIS TIME. GALE FORCE GUSTS MAY BE POSSIBLE WEDNESDAY.
&&
.PREV DISCUSSION... /ISSUED 343 AM CDT MON AUG 17 2015/
SHORT TERM...
TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM.
THE MAIN FOCUS INTO TONIGHT IS ON A COLD FRONT THAT STALLS OUT OVER
THE REGION AND WHEN/IF WE WILL GET RAIN SHOWERS/CONVECTION AHEAD OF
IT.
CURRENTLY...THIS COLD FRONT EXTENDS FROM EASTERN LAKE SUPERIOR
SOUTHWEST INTO CENTRAL IOWA WHICH IS JUST UPSTREAM FROM AN ELONGATED
MID LEVEL SHORT WAVE TROUGH NOTED ON WATER VAPOR IR/RAP ANALYSIS.
RAIN SHOWERS/CONVECTION HAS DEVELOPED AHEAD OF THE FRONT...BUT SEEMS
TO BE GOING A TAD SLOWER THAN PREVIOUS GUIDANCE HAD SUGGESTED.
THUS...HAVE SLOWED DOWN THE EASTWARD PROGRESSION OF THE RAIN SHOWERS
THIS MORNING.
17.07Z RAP SOUNDINGS SHOW A SKINNY CAPE PROFILE FOR TODAY AHEAD OF
THE FRONT WITH LITTLE TO NO 0-6KM WIND SHEAR...SO AM NOT EXPECTING
ANY SEVERE WEATHER WITH CONVECTION TODAY. THE 17.00Z NAM SEEMS TO
BE OVERDONE WITH THE BAND OF HIGH INSTABILITY AND RESULTANT
CONVECTION THAT IT DEVELOPS INTO FAR SOUTHEASTERN WISCONSIN THIS
AFTERNOON. WHILE IT DOES LOOK LIKE WE WILL SEE SOME WARMING THIS
MORNING IN THE WARM SECTOR...THE NAM BRINGS SURFACE DEW POINTS UP
INTO THE MID 70S IN THIS BAND WHERE MID TO UPPER 60S WILL BE MORE
LIKELY. THE COLD FRONT SHOULD FEATURE SOME RAIN SHOWERS/STORMS AS
IT COMES THROUGH THIS AFTERNOON/EVENING ALONG WITH THE MID LEVEL
SHORT WAVE TROUGH...IT IS JUST HOW MUCH WILL WE SEE. ACTIVITY
SHOULD LESSEN TONIGHT AS THE BETTER FORCING SHIFTS OFF TO THE EAST
AND THE SURFACE FRONT STALLS.
LONG TERM...
TUESDAY THROUGH WEDNESDAY... FORECAST CONFIDENCE MEDIUM.
AN AMPLIFIED UPPER TROUGH DIGGING INTO THE CENTER OF THE COUNTRY
WILL BRING A POTENT SURFACE LOW TO THE MIDWEST TUESDAY NIGHT THROUGH
WEDNESDAY. THE 850MB BAROCLINIC ZONE WILL BE STALLED IN SOUTHERN WI.
UPPER DIVERGENCE FROM THE RIGHT ENTRANCE REGION OF THE UPPER JET
WILL LINGER OVER SOUTHERN WI ALL DAY TUESDAY. THE NOSE OF THE LOW
LEVEL JET SHOULD BRIEFLY POINT INTO SOUTHERN WI LATE TUESDAY
AFTERNOON/EARLY EVENING... SO THIS WILL BE OUR BEST CHANCE FOR
SHOWERS AND THUNDERSTORMS.
THIS IS A PARTICULARLY STRONG SYSTEM FOR THIS TIME OF YEAR.
HOWEVER... WEAK MID LEVEL LAPSE RATES WILL KEEP CAPE/INSTABILITY ON
THE LOW SIDE... BUT SHEAR WILL BE MODERATE TO STRONG ESPECIALLY IN
THE LOW LEVELS. THIS SYSTEM HAS THE POTENTIAL FOR ISOLATED SEVERE
WEATHER SO SPC HAS THE MKX AREA IN A MARGINAL RISK WITH A SLIGHT
RISK IN THE FAR SOUTHWEST COUNTY WARNING AREA.
EXPECT THE DRY SLOT/COLD FRONT TO MOVE ACROSS SOUTHERN WI EARLY
WEDNESDAY MORNING. WESTERLY WINDS ON WEDNESDAY WILL BE GUSTY...
ALTHOUGH THERE IS MODEL UNCERTAINTY FOR HOW HIGH THE WINDS WILL BE.
THURSDAY THROUGH FRIDAY... FORECAST CONFIDENCE MEDIUM.
THE UPPER LOW WILL TAKE ITS TIME EXITING THE GREAT LAKES REGION. A
HIGH PRESSURE RIDGE WILL SPREAD IN THU NIGHT. MODELS ARE SHOWING
WISCONSIN DRY WITH MOSTLY CLEAR SKIES FOR THIS PERIOD.
SATURDAY THROUGH MONDAY... FORECAST CONFIDENCE MEDIUM.
A LOW PRESSURE TROUGH WILL CROSS THE UPPER MIDWEST/SOUTHERN CANADA
OVER THE WEEKEND. THE TRAILING COLD FRONT WILL BRING A CHANCE FOR
SHOWERS AND THUNDERSTORMS TO WISCONSIN SATURDAY NIGHT INTO SUNDAY.
AVIATION/12Z TAFS/...
SOME GUSTY CONDITIONS OF UP TO 20KT ARE POSSIBLE THIS
MORNING/AFTERNOON AHEAD OF A COLD FRONT WHICH WILL STALL OUT ACROSS
THE REGION TONIGHT. RAIN SHOWERS AND THUNDERSTORMS ARE LIKELY THIS
AFTERNOON INTO THIS EVENING WITH SOME BRIEF DROPS IN VISIBILITY
POSSIBLE WITH THEM. IF RAIN DOES FALL TODAY...THERE COULD BE SOME
FOG THAT DEVELOPS TONIGHT WITH WINDS GOING LIGHT ALONG THE STALLING
OUT COLD FRONT...BUT SKIES SHOULD BE CLOUDY WHICH MAY LIMIT HOW MUCH
RADIATIONAL COOLING OCCURS.
MARINE...
WINDS WILL SHIFT FROM THE SOUTHWEST TO THE NORTH BEFORE BECOMING
LIGHT AND VARIABLE TONIGHT AS A COLD FRONT MOVES DOWN INTO THE
REGION AND STALLS OUT. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
AHEAD OF THE FRONT WITH SOME GUSTY WINDS ACCOMPANYING A FEW OF THE
THUNDERSTORMS. WINDY CONDITIONS ARE EXPECTED ON WEDNESDAY AS A LOW
PRESSURE SYSTEM MOVES THROUGH THE REGION.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...WOOD
TODAY/TONIGHT AND AVIATION/MARINE...HALBACH
TUESDAY THROUGH SUNDAY...MRC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
659 AM CDT MON AUG 17 2015
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 348 AM CDT MON AUG 17 2015
THE COLD FRONT EXTENDED FROM NORTH CENTRAL WISCONSIN INTO
NORTHERN KANSAS EARLY THIS MORNING. REGIONAL RADARS INDICATE THE
REMAINING SHOWERS HAVE BECOME ORIENTED ALONG AND JUST BEHIND THE
FRONT WITH THE LARGEST CONCENTRATION MOVING SLOWLY NORTHEAST OUT
OF NORTHERN IOWA. THIS AREA OF SHOWERS IS ASSOCIATED WITH A WEAK
SECONDARY MOISTURE TRANSPORT AXIS THAT THE 17.06Z RAP MOVES
NORTHEAST INTO THE AREA AND THEN STARTS TO WEAKEN IT AROUND 12Z
INTO THE REST OF THE MORNING. THE 17.06Z HRRR SHOWS THESE TRENDS
WELL AND BRINGS IN THE BAND OF RAIN THROUGH ABOUT 12Z AND THEN
SHOWS IT WEAKENING AS THE MORNING PROGRESSES WITH THE WEAKENING
MOISTURE TRANSPORT.
THE FRONT WILL CONTINUE TO WORK SLOWLY SOUTH THROUGH THE REST OF
THE DAY BUT SOME UNCERTAINTY ON JUST HOW MUCH ACTIVITY WILL OCCUR
WITH IT. MOST OF THE HI-RES MESO MODELS SHOW A CONTINUED
DIMINISHING TREND INTO THE EARLY AFTERNOON WITH MAINLY SCATTERED
COVERAGE. WITH NO SHORT WAVE TROUGHS TO PROVIDE ANY DYNAMIC
SUPPORT TODAY...ANY INCREASE IN ACTIVITY WILL HAVE TO BE
THERMODYNAMICALLY DRIVEN. WITH SOME HEATING OCCURRING UNDER THE
CLOUD COVER...THE 17.00Z NAM SUGGESTS THE MU CAPE COULD INCREASE
INTO THE 1000-1500 J/KG RANGE ACROSS THE SOUTH DURING THE
AFTERNOON. THE FRONTOGENESIS IN THE 1000-850 MB LAYER ALSO SHOWS A
DIURNAL INCREASE DURING THE AFTERNOON AND THIS MAY BE ENOUGH TO
MAINTAIN SOME SCATTERED ACTIVITY ALONG THE FRONT.
DIFFERENCES AMONG THE MODELS THEN START TO SHOW UP IN HOW FAR
SOUTH THE FRONT PROGRESSES TONIGHT. THE NAM AND THE MESO MODELS
SUGGEST A GENERAL LULL IN THE ACTIVITY THIS EVENING BUT THEN START
TO BRING THE FRONT BACK LATE TONIGHT AHEAD OF THE NEXT SYSTEM.
WATER VAPOR SATELLITE THIS MORNING SHOWS THIS NEXT SHORT WAVE
TROUGH WAS OVER EASTERN WASHINGTON AND OREGON. THE GENERAL TREND
IN THE MODELS WITH THIS SYSTEM REMAINS THE SAME WITH IT
INTENSIFYING AS IT APPROACHES...FORMING A CLOSED UPPER LEVEL LOW
OVER THE EASTERN DAKOTAS TUESDAY. SOME DIFFERENCES ON HOW STRONG
THE WAVE BECOMES WITH THE 17.00Z GFS CONTINUING ITS TREND OF BEING
THE STRONGEST WITH IT AND ALSO THEN THE SLOWEST TO MOVE IT OUT.
THE UPPER LEVEL LOW AND SHORT WAVE TROUGH SHOULD THEN LIFT
NORTHEAST ACROSS MINNESOTA AND INTO CANADA TUESDAY NIGHT INTO
WEDNESDAY. THE FORCING AHEAD OF THIS WAVE WILL START TO INCREASE
LATE TONIGHT AS HEIGHT FALLS START TO SPREAD OVER THE REGION. THE
FORCING LOOKS TO BE THE STRONGEST TUESDAY NIGHT AS MODERATE PV
ADVECTION IN THE 500-300 MB LAYER MOVES ACROSS WITH THE SHORT WAVE
TROUGH. THE BEST MOISTURE TRANSPORT SHOULD STAY TO THE WEST OF THE
AREA TONIGHT BUT THERE IS SOME SUGGESTION OF A WEAK BRANCH COMING
INTO THE FRONT FOR LATE TONIGHT. THIS MOISTURE TRANSPORT THEN
CONTINUES TO INCREASE THROUGH THE DAY TUESDAY AND LOOKS TO BE
RIGHT INTO THE AREA FOR TUESDAY EVENING. BASED ON THESE SIGNALS
PLAN TO START INCREASING THE RAIN CHANCES LATE TONIGHT ACROSS THE
SOUTH WITH THE CHANCES THEN INCREASING ACROSS THE ENTIRE AREA
TUESDAY. THE HIGHEST RAIN CHANCES SHOULD OCCUR TUESDAY EVENING AS
THE FRONT MOVES BACK INTO THE AREA AS A SURFACE LOW TRACKS FROM
IOWA INTO MINNESOTA. THEN EXPECTING THE DRY SLOT TO START WORKING
IN FROM THE SOUTH FOR LATE TUESDAY NIGHT INTO WEDNESDAY AS THE
ENTIRE SYSTEM LIFTS OFF TO THE NORTH.
QUESTIONS ON JUST HOW MUCH OF A SEVERE THREAT THERE WILL BE WITH
THIS SYSTEM. EXPECTING RAIN TO BE FALLING AHEAD OF THE WARM FRONT
AND THE WARM SECTOR ITSELF TO NOT BE VERY CLEAN. THIS SHOULD LIMIT
THE AMOUNT OF INSTABILITY WITH BOTH THE NAM AND GFS SHOWING LESS
THEN 750 J/KG OF ML CAPE AVAILABLE IN THE WARM SECTOR. WITH THE
GFS BEING THE STRONGEST WITH THE SYSTEM IT PRODUCES THE MOST SHEAR
WITH 30 TO 35 KNOTS IN THE 0-3KM LAYER WHILE THE NAM STRUGGLES TO
GET 20 KNOTS IN HERE IN THE SAME LAYER. COULD SEE SOME STRONGER
STORMS DEVELOP BUT STILL NOT THINKING THERE WOULD BE MUCH IN THE
WAY OF AN ORGANZID SEVERE EVENT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 348 AM CDT MON AUG 17 2015
ANY LINGERING RAIN CHANCES FROM THIS SYSTEM SHOULD MAINLY BE
LIMITED TO THE INTERSTATE 94 CORRIDOR FOR WEDNESDAY NIGHT BEFORE
DRY WEATHER SETTLES IN FOR THURSDAY THROUGH FRIDAY. THE RAIN
CHANCES THEN LOOK LIKE THEY WILL RETURN FOR THE UPCOMING WEEKEND.
PRETTY GOOD AGREEMENT BETWEEN THE GFS AND 17.00Z ECMWF OF A COLD
FRONT SWEEPING ACROSS THE REGION SATURDAY AND SATURDAY NIGHT. THE
SHORT WAVE TROUGH WITH THIS SYSTEM LOOKS TO BE PRETTY SIMILAR TO
THE UPCOMING SYSTEM FOR TUESDAY. IT SHOULD COME IN OFF THE
NORTHERN PACIFIC AND INTENSIFY ONCE IT CROSSES THE NORTHERN
ROCKIES BUT IT MAY TRACK SLIGHTLY FARTHER TO THE NORTH ACROSS
NORTH DAKOTA OR EXTREME SOUTHERN CANADA. THIS COULD BRING IN A
DECENT ROUND OF SHOWERS AND STORMS AGAIN AS THE FRONT COMES
ACROSS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 659 AM CDT MON AUG 17 2015
SHOWERS AND ISOLATED THUNDERSTORMS WILL EDGE SOUTHEAST ACROSS THE
AREA THIS MORNING ALONG A WEAKENING COLD FRONT WITH PERIODS OF
MVFR TO IFR CONDITIONS POSSIBLE AT TIMES. THIS ACTIVITY WILL
GRADUALLY TAPER OFF AND SHIFT SOUTHEAST OF KRST BY LATE THIS
MORNING AND BY MID TO LATE AFTERNOON AT KLSE. CEILINGS COULD FALL
TO AROUND 400 FT UNDER THE HEAVIER SHOWERS AND THE VISIBILITY MAY
BE REDUCED TO 2 SM OR LESS. IN THE WAKE OF THE FRONT A BRIEF
PERIOD OF MVFR STRATUS IS EXPECTED THEN CEILINGS SHOULD IMPROVE TO
VFR AND STAY THERE THROUGH THE OVERNIGHT HOURS.
&&
.HYDROLOGY...
ISSUED AT 348 AM CDT MON AUG 17 2015
DECENT RAINFALL AMOUNTS ARE EXPECTED WITH THE UPCOMING SYSTEM FROM
LATE TONIGHT THROUGH WEDNESDAY. CURRENTLY EXPECTING RAINFALL
AMOUNTS OF 1 TO 1.5 INCHES OVER THIS SPREAD OUT PERIOD. THESE
AMOUNTS AND THE SOMEWHAT EXTENDED TIME FRAME OVER WHICH THEY ARE
EXPECTED...SHOULD NOT BE ENOUGH TO CAUSE ANY FLOODING
PROBLEMS...ESPECIALLY GIVEN THE RECENT DRY CONDITIONS THAT HAVE
DEVELOPED. NOT ANTICIPATING THE NEED FOR ANY HYDROLOGIC HEADLINES
FROM THIS SYSTEM.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...WETENKAMP
HYDROLOGY...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
349 AM CDT MON AUG 17 2015
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 348 AM CDT MON AUG 17 2015
THE COLD FRONT EXTENDED FROM NORTH CENTRAL WISCONSIN INTO
NORTHERN KANSAS EARLY THIS MORNING. REGIONAL RADARS INDICATE THE
REMAINING SHOWERS HAVE BECOME ORIENTED ALONG AND JUST BEHIND THE
FRONT WITH THE LARGEST CONCENTRATION MOVING SLOWLY NORTHEAST OUT
OF NORTHERN IOWA. THIS AREA OF SHOWERS IS ASSOCIATED WITH A WEAK
SECONDARY MOISTURE TRANSPORT AXIS THAT THE 17.06Z RAP MOVES
NORTHEAST INTO THE AREA AND THEN STARTS TO WEAKEN IT AROUND 12Z
INTO THE REST OF THE MORNING. THE 17.06Z HRRR SHOWS THESE TRENDS
WELL AND BRINGS IN THE BAND OF RAIN THROUGH ABOUT 12Z AND THEN
SHOWS IT WEAKENING AS THE MORNING PROGRESSES WITH THE WEAKENING
MOISTURE TRANSPORT.
THE FRONT WILL CONTINUE TO WORK SLOWLY SOUTH THROUGH THE REST OF
THE DAY BUT SOME UNCERTAINTY ON JUST HOW MUCH ACTIVITY WILL OCCUR
WITH IT. MOST OF THE HI-RES MESO MODELS SHOW A CONTINUED
DIMINISHING TREND INTO THE EARLY AFTERNOON WITH MAINLY SCATTERED
COVERAGE. WITH NO SHORT WAVE TROUGHS TO PROVIDE ANY DYNAMIC
SUPPORT TODAY...ANY INCREASE IN ACTIVITY WILL HAVE TO BE
THERMODYNAMICALLY DRIVEN. WITH SOME HEATING OCCURRING UNDER THE
CLOUD COVER...THE 17.00Z NAM SUGGESTS THE MU CAPE COULD INCREASE
INTO THE 1000-1500 J/KG RANGE ACROSS THE SOUTH DURING THE
AFTERNOON. THE FRONTOGENESIS IN THE 1000-850 MB LAYER ALSO SHOWS A
DIURNAL INCREASE DURING THE AFTERNOON AND THIS MAY BE ENOUGH TO
MAINTAIN SOME SCATTERED ACTIVITY ALONG THE FRONT.
DIFFERENCES AMONG THE MODELS THEN START TO SHOW UP IN HOW FAR
SOUTH THE FRONT PROGRESSES TONIGHT. THE NAM AND THE MESO MODELS
SUGGEST A GENERAL LULL IN THE ACTIVITY THIS EVENING BUT THEN START
TO BRING THE FRONT BACK LATE TONIGHT AHEAD OF THE NEXT SYSTEM.
WATER VAPOR SATELLITE THIS MORNING SHOWS THIS NEXT SHORT WAVE
TROUGH WAS OVER EASTERN WASHINGTON AND OREGON. THE GENERAL TREND
IN THE MODELS WITH THIS SYSTEM REMAINS THE SAME WITH IT
INTENSIFYING AS IT APPROACHES...FORMING A CLOSED UPPER LEVEL LOW
OVER THE EASTERN DAKOTAS TUESDAY. SOME DIFFERENCES ON HOW STRONG
THE WAVE BECOMES WITH THE 17.00Z GFS CONTINUING ITS TREND OF BEING
THE STRONGEST WITH IT AND ALSO THEN THE SLOWEST TO MOVE IT OUT.
THE UPPER LEVEL LOW AND SHORT WAVE TROUGH SHOULD THEN LIFT
NORTHEAST ACROSS MINNESOTA AND INTO CANADA TUESDAY NIGHT INTO
WEDNESDAY. THE FORCING AHEAD OF THIS WAVE WILL START TO INCREASE
LATE TONIGHT AS HEIGHT FALLS START TO SPREAD OVER THE REGION. THE
FORCING LOOKS TO BE THE STRONGEST TUESDAY NIGHT AS MODERATE PV
ADVECTION IN THE 500-300 MB LAYER MOVES ACROSS WITH THE SHORT WAVE
TROUGH. THE BEST MOISTURE TRANSPORT SHOULD STAY TO THE WEST OF THE
AREA TONIGHT BUT THERE IS SOME SUGGESTION OF A WEAK BRANCH COMING
INTO THE FRONT FOR LATE TONIGHT. THIS MOISTURE TRANSPORT THEN
CONTINUES TO INCREASE THROUGH THE DAY TUESDAY AND LOOKS TO BE
RIGHT INTO THE AREA FOR TUESDAY EVENING. BASED ON THESE SIGNALS
PLAN TO START INCREASING THE RAIN CHANCES LATE TONIGHT ACROSS THE
SOUTH WITH THE CHANCES THEN INCREASING ACROSS THE ENTIRE AREA
TUESDAY. THE HIGHEST RAIN CHANCES SHOULD OCCUR TUESDAY EVENING AS
THE FRONT MOVES BACK INTO THE AREA AS A SURFACE LOW TRACKS FROM
IOWA INTO MINNESOTA. THEN EXPECTING THE DRY SLOT TO START WORKING
IN FROM THE SOUTH FOR LATE TUESDAY NIGHT INTO WEDNESDAY AS THE
ENTIRE SYSTEM LIFTS OFF TO THE NORTH.
QUESTIONS ON JUST HOW MUCH OF A SEVERE THREAT THERE WILL BE WITH
THIS SYSTEM. EXPECTING RAIN TO BE FALLING AHEAD OF THE WARM FRONT
AND THE WARM SECTOR ITSELF TO NOT BE VERY CLEAN. THIS SHOULD LIMIT
THE AMOUNT OF INSTABILITY WITH BOTH THE NAM AND GFS SHOWING LESS
THEN 750 J/KG OF ML CAPE AVAILABLE IN THE WARM SECTOR. WITH THE
GFS BEING THE STRONGEST WITH THE SYSTEM IT PRODUCES THE MOST SHEAR
WITH 30 TO 35 KNOTS IN THE 0-3KM LAYER WHILE THE NAM STRUGGLES TO
GET 20 KNOTS IN HERE IN THE SAME LAYER. COULD SEE SOME STRONGER
STORMS DEVELOP BUT STILL NOT THINKING THERE WOULD BE MUCH IN THE
WAY OF AN ORGANZID SEVERE EVENT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 348 AM CDT MON AUG 17 2015
ANY LINGERING RAIN CHANCES FROM THIS SYSTEM SHOULD MAINLY BE
LIMITED TO THE INTERSTATE 94 CORRIDOR FOR WEDNESDAY NIGHT BEFORE
DRY WEATHER SETTLES IN FOR THURSDAY THROUGH FRIDAY. THE RAIN
CHANCES THEN LOOK LIKE THEY WILL RETURN FOR THE UPCOMING WEEKEND.
PRETTY GOOD AGREEMENT BETWEEN THE GFS AND 17.00Z ECMWF OF A COLD
FRONT SWEEPING ACROSS THE REGION SATURDAY AND SATURDAY NIGHT. THE
SHORT WAVE TROUGH WITH THIS SYSTEM LOOKS TO BE PRETTY SIMILAR TO
THE UPCOMING SYSTEM FOR TUESDAY. IT SHOULD COME IN OFF THE
NORTHERN PACIFIC AND INTENSIFY ONCE IT CROSSES THE NORTHERN
ROCKIES BUT IT MAY TRACK SLIGHTLY FARTHER TO THE NORTH ACROSS
NORTH DAKOTA OR EXTREME SOUTHERN CANADA. THIS COULD BRING IN A
DECENT ROUND OF SHOWERS AND STORMS AGAIN AS THE FRONT COMES
ACROSS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1145 PM CDT SUN AUG 16 2015
FIRST LINE OF SHOWERS AND THUNDERSTORMS FROM EARLIER THIS EVENING
HAS WEAKENED AND STALLED OUT ACROSS SOUTHEAST MN INTO WEST-CENTRAL
WI. HOWEVER...EXPECT SECOND AREA OF MAINLY SHOWERS TO MOVE ACROSS
TAF AIRFIELDS OVERNIGHT INTO MONDAY MORNING. THERE ARE CURRENTLY
SOME EMBEDDED THUNDERSTORMS ACROSS NORTHERN IA INTO SOUTH-CENTRAL
MN...BUT EXPECT SPATIAL COVERAGE TO BE LIMITED AND WILL NOT
INCLUDE IN 17.06Z TAFS.
LOW CONFIDENCE ON CEILINGS/VISIBILITY GIVEN BROKEN NATURE OF
CONVECTION AND VARYING FORECAST GUIDANCE. FOR NOW...WILL CARRY
PREDOMINANT MVFR CONDITIONS THROUGH MUCH OF THE PERIOD GIVEN
UPSTREAM OBSERVATIONS...BUT THERE VERY WELL COULD BE PROLONGED
PERIODS OF VFR CONDITIONS IN THE MIX. THINK MOST OF THE
PRECIPITATION WILL END MONDAY MORNING...BUT ADDITIONAL CONVECTIVE
CHANCES EXIST INTO MONDAY AFTERNOON. LIGHT SOUTH-SOUTHWEST WIND
WILL SHIFT TO THE NORTH-NORTHWEST AFTER FRONTAL PASSAGE.
&&
.HYDROLOGY...
ISSUED AT 348 AM CDT MON AUG 17 2015
DECENT RAINFALL AMOUNTS ARE EXPECTED WITH THE UPCOMING SYSTEM FROM
LATE TONIGHT THROUGH WEDNESDAY. CURRENTLY EXPECTING RAINFALL
AMOUNTS OF 1 TO 1.5 INCHES OVER THIS SPREAD OUT PERIOD. THESE
AMOUNTS AND THE SOMEWHAT EXTENDED TIME FRAME OVER WHICH THEY ARE
EXPECTED...SHOULD NOT BE ENOUGH TO CAUSE ANY FLOODING
PROBLEMS...ESPECIALLY GIVEN THE RECENT DRY CONDITIONS THAT HAVE
DEVELOPED. NOT ANTICIPATING THE NEED FOR ANY HYDROLOGIC HEADLINES
FROM THIS SYSTEM.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...ROGERS
HYDROLOGY...04
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
343 AM CDT MON AUG 17 2015
.SHORT TERM...
TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM.
THE MAIN FOCUS INTO TONIGHT IS ON A COLD FRONT THAT STALLS OUT OVER
THE REGION AND WHEN/IF WE WILL GET RAIN SHOWERS/CONVECTION AHEAD OF
IT.
CURRENTLY...THIS COLD FRONT EXTENDS FROM EASTERN LAKE SUPERIOR
SOUTHWEST INTO CENTRAL IOWA WHICH IS JUST UPSTREAM FROM AN ELONGATED
MID LEVEL SHORT WAVE TROUGH NOTED ON WATER VAPOR IR/RAP ANALYSIS.
RAIN SHOWERS/CONVECTION HAS DEVELOPED AHEAD OF THE FRONT...BUT SEEMS
TO BE GOING A TAD SLOWER THAN PREVIOUS GUIDANCE HAD SUGGESTED.
THUS...HAVE SLOWED DOWN THE EASTWARD PROGRESSION OF THE RAIN SHOWERS
THIS MORNING.
17.07Z RAP SOUNDINGS SHOW A SKINNY CAPE PROFILE FOR TODAY AHEAD OF
THE FRONT WITH LITTLE TO NO 0-6KM WIND SHEAR...SO AM NOT EXPECTING
ANY SEVERE WEATHER WITH CONVECTION TODAY. THE 17.00Z NAM SEEMS TO
BE OVERDONE WITH THE BAND OF HIGH INSTABILITY AND RESULTANT
CONVECTION THAT IT DEVELOPS INTO FAR SOUTHEASTERN WISCONSIN THIS
AFTERNOON. WHILE IT DOES LOOK LIKE WE WILL SEE SOME WARMING THIS
MORNING IN THE WARM SECTOR...THE NAM BRINGS SURFACE DEW POINTS UP
INTO THE MID 70S IN THIS BAND WHERE MID TO UPPER 60S WILL BE MORE
LIKELY. THE COLD FRONT SHOULD FEATURE SOME RAIN SHOWERS/STORMS AS
IT COMES THROUGH THIS AFTERNOON/EVENING ALONG WITH THE MID LEVEL
SHORT WAVE TROUGH...IT IS JUST HOW MUCH WILL WE SEE. ACTIVITY
SHOULD LESSEN TONIGHT AS THE BETTER FORCING SHIFTS OFF TO THE EAST
AND THE SURFACE FRONT STALLS.
.LONG TERM...
TUESDAY THROUGH WEDNESDAY... FORECAST CONFIDENCE MEDIUM.
AN AMPLIFIED UPPER TROUGH DIGGING INTO THE CENTER OF THE COUNTRY
WILL BRING A POTENT SURFACE LOW TO THE MIDWEST TUESDAY NIGHT THROUGH
WEDNESDAY. THE 850MB BAROCLINIC ZONE WILL BE STALLED IN SOUTHERN WI.
UPPER DIVERGENCE FROM THE RIGHT ENTRANCE REGION OF THE UPPER JET
WILL LINGER OVER SOUTHERN WI ALL DAY TUESDAY. THE NOSE OF THE LOW
LEVEL JET SHOULD BRIEFLY POINT INTO SOUTHERN WI LATE TUESDAY
AFTERNOON/EARLY EVENING... SO THIS WILL BE OUR BEST CHANCE FOR
SHOWERS AND THUNDERSTORMS.
THIS IS A PARTICULARLY STRONG SYSTEM FOR THIS TIME OF YEAR.
HOWEVER... WEAK MID LEVEL LAPSE RATES WILL KEEP CAPE/INSTABILITY ON
THE LOW SIDE... BUT SHEAR WILL BE MODERATE TO STRONG ESPECIALLY IN
THE LOW LEVELS. THIS SYSTEM HAS THE POTENTIAL FOR ISOLATED SEVERE
WEATHER SO SPC HAS THE MKX AREA IN A MARGINAL RISK WITH A SLIGHT
RISK IN THE FAR SOUTHWEST COUNTY WARNING AREA.
EXPECT THE DRY SLOT/COLD FRONT TO MOVE ACROSS SOUTHERN WI EARLY
WEDNESDAY MORNING. WESTERLY WINDS ON WEDNESDAY WILL BE GUSTY...
ALTHOUGH THERE IS MODEL UNCERTAINTY FOR HOW HIGH THE WINDS WILL BE.
THURSDAY THROUGH FRIDAY... FORECAST CONFIDENCE MEDIUM.
THE UPPER LOW WILL TAKE ITS TIME EXITING THE GREAT LAKES REGION. A
HIGH PRESSURE RIDGE WILL SPREAD IN THU NIGHT. MODELS ARE SHOWING
WISCONSIN DRY WITH MOSTLY CLEAR SKIES FOR THIS PERIOD.
SATURDAY THROUGH MONDAY... FORECAST CONFIDENCE MEDIUM.
A LOW PRESSURE TROUGH WILL CROSS THE UPPER MIDWEST/SOUTHERN CANADA
OVER THE WEEKEND. THE TRAILING COLD FRONT WILL BRING A CHANCE FOR
SHOWERS AND THUNDERSTORMS TO WISCONSIN SATURDAY NIGHT INTO SUNDAY.
&&
.AVIATION/12Z TAFS/...
SOME GUSTY CONDITIONS OF UP TO 20KT ARE POSSIBLE THIS
MORNING/AFTERNOON AHEAD OF A COLD FRONT WHICH WILL STALL OUT ACROSS
THE REGION TONIGHT. RAIN SHOWERS AND THUNDERSTORMS ARE LIKELY THIS
AFTERNOON INTO THIS EVENING WITH SOME BRIEF DROPS IN VISIBILITY
POSSIBLE WITH THEM. IF RAIN DOES FALL TODAY...THERE COULD BE SOME
FOG THAT DEVELOPS TONIGHT WITH WINDS GOING LIGHT ALONG THE STALLING
OUT COLD FRONT...BUT SKIES SHOULD BE CLOUDY WHICH MAY LIMIT HOW MUCH
RADIATIONAL COOLING OCCURS.
&&
.MARINE...
WINDS WILL SHIFT FROM THE SOUTHWEST TO THE NORTH BEFORE BECOMING
LIGHT AND VARIABLE TONIGHT AS A COLD FRONT MOVES DOWN INTO THE
REGION AND STALLS OUT. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
AHEAD OF THE FRONT WITH SOME GUSTY WINDS ACCOMPANYING A FEW OF THE
THUNDERSTORMS. WINDY CONDITIONS ARE EXPECTED ON WEDNESDAY AS A LOW
PRESSURE SYSTEM MOVES THROUGH THE REGION.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...HALBACH
TUESDAY THROUGH SUNDAY...MRC
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
235 PM MDT MON AUG 17 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 235 PM MDT MON AUG 17 2015
FORECAST CHALLENGES DEAL WITH A VARIETY OF TOPICS THIS AFTERNOON.
WE HAVE CHANCES FOR SEVERE THUNDERSTORMS EAST OF THE LARAMIE
RANGE...RED FLAG CONCERNS OUT WEST AND THEN THE RETURN OF FOG AND
STRATUS TONIGHT.
CURRENTLY...LATEST VISIBLE IMAGERY SHOWING STRATUS LAYER HANGING
TOUGH GENERALLY ALONG AND SOUTH OF A LINE FROM GLENDO TO ALLIANCE
THIS AFTERNOON. LATEST SPC MESOANALYST PAGE SHOWING A SOLIDLY
CAPPED ENVIRONMENT UNDER THIS STRATUS WITH CONVECTIVE INHIBITION
ANYWHERE FROM -50 J/KG UP BY WHEATLAND TO -300 J/KG OUT BY SIDNEY.
CONVERSE...NIOBRARA COUNTIES IN EAST CENTRAL WYOMING AND THE
NORTHERN PANHANDLE HAS BEGUN TO BREAK OUT WITH TEMPERATURES
CLIMBING INTO THE LOW 70S AS OF 1 PM. IR IMAGERY SHOWING AN UPPER
SHORTWAVE TRACKING INTO SOUTH CENTRAL MONTANA AND NORTH CENTRAL
WYOMING THIS AFTERNOON. NEED TO BE WATCHING OUR NORTHERN COUNTIES
TODAY FOR POSSIBLE SEVERE THUNDERSTORM DEVELOPMENT. LATEST SPC DAY
1 OUTLOOK WAS EXPANDED NORTH TO INCLUDE THIS AREA AS WELL AS
WESTERN SOUTH DAKOTA AND NORTHEASTERN WYOMING. DID REMOVE SEVERE
THUNDERSTORM WORDING FROM OUR SOUTHERN ZONES AS THEY WILL MOST
LIKELY STAY IN STRATUS THROUGH THE AFTERNOON.
DID INTRODUCE SEVERE THUNDERSTORMS ACROSS OUR NORTHERN ZONES FOR
EARLY THIS EVENING. THAT SHORTWAVE MOVES INTO NORTHWESTERN SOUTH
DAKOTA. LATEST HRRR SIMULATED RADAR SHOWING SOME PRETTY STRONG
STORMS DEVELOPING ALONG A SQUALL LINE THAT DEVELOPS AFTER 00Z THAT
COULD PERSIST INTO THE LATE EVENING HOURS. STILL VERY CONDITIONAL
THOUGH AS LATEST MESOANALYSIS PAGE CAPS OFF LOW LEVELS AFTER
SUNSET. WOULD THINK THE ASSOCIATED SURFACE TROUGH/FRONT WITH THE
UPPER SHORTWAVE WOULD BREAK THAT CAP THOUGH.
TO THE WEST...KEPT CURRENT FIRE HEADLINES GOING AS THEY ARE FOR
FWZ 304 AND 306. THEY ARE VERY CLOSE TO VERIFYING RIGHT NOW...SO
RED FLAG WARNINGS ARE ON TRACK. NO CHANGES PLANNED.
THERE IS A BRIEF PERIOD THIS EVENING BEFORE THE SURFACE
FRONT/TROUGH MOVES THROUGH THE SOUTHERN CWFA WHERE WE SEE
SOUTHEASTERLY WINDS. WITH CURRENT STRATUS ALREADY IN PLACE...THINK
THERE IS A PERIOD BETWEEN ABOUT 9 PM AND 3 AM WHERE WE COULD SEE
FOG ONCE AGAIN. ONCE THE SURFACE TROUGH MOVES THROUGH...FAIRLY
STRONG NORTHWEST DOWNSLOPING WINDS SHOULD SCOUR OUT FOG/STRATUS
SHORTLY AFTER 06Z OR SO FROM NORTH TO SOUTH.
KEPT POPS GOING FOR OUR EASTERN ZONES WEDNESDAY AS WRAP-AROUND
ENERGY FROM THE DEPARTING LOW IMPACTS THE PANHANDLE AND MAYBE OUR
EXTREME EASTERN COUNTIES.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 235 PM MDT MON AUG 17 2015
A GENERALLY DRY AND MILD/WARM PATTERN EXPECTED TO PREVAIL AVER THE
CWA DURING THE PERIOD. TEMPERATURES WILL TURN WARMER THURSDAY AS
DOWNSLOPE FLOW DEVELOPS IN RESPONSE TO LEE TROFFING SETTING UP
OVER THE HIGH PLAINS. THIS WILL CONTINUE THROUGH FRIDAY AHEAD OF A
DIGGING UPPER TROF THAT WILL MOVE INTO THE NRN ROCKYS FRIDAY
NIGHT. THIS WILL PUSH THE NEXT COOL FRONT ACROSS THE CWA SATURDAY
WITH A BIT OF CONVECTION POSSIBLE WITH IT. EC QUICKER THAN THE GFS
WITH THIS SYSTEM BY ABOUT 12 HOURS WITH COULD IMPACT MAX TEMPS FOR
SATURDAY. SUNDAY AND MONDAY DRY AND SEASONAL WITH A BUILDING
UPPER RIDGE OVER THE ROCKY MTNS
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1131 AM MDT MON AUG 17 2015
SFC UPSLOPE FLOW KEEPING MVFR/IFR CIGS IN PLACE OVER MANY AREAS EAST
OF THE LARAMIE RANGES THIS MORNING THOUGH SOME THINNING NOTED OVER
THE NORTHERN PANHANDLE. MAIN PROBLEM WILL BE DETERMINING HOW MUCH
IMPROVEMENT OCCURS THIS AFTERNOON. WITH SFC UPSLOPE FLOW EXPECTED
TO PERSIST WILL FAVOR KEEPING LOW CIGS IN PLACE FOR KCYS TO KSNY
WHILE IMPROVING TO VFR AT KAIA. EXPECT CONDITIONS TO DETERIORATE TO
MVFR/IFR MOST AREAS TONIGHT AS NEXT COLD FRONT PASSES AND REINFORCES
UPSLOPE FLOW WITH AREAS OF RAIN DEVELOPING OVER THE PLAINS AS
WELL.
&&
.FIRE WEATHER...
ISSUED AT 235 PM MDT MON AUG 17 2015
WINDS HAVE BEGUN TO INCREASE OUT ACROSS CARBON COUNTY AND WESTERN
ALBANY COUNTY THIS AFTERNOON. LATEST OBSERVATIONS SHOWING
HUMIDITIES FALLING INTO LOW TEENS AND UPPER SINGLE DIGITS AT 1 PM.
WINDS ARE ON THE INCREASE AS WELL...SO CURRENT FIRE WEATHER
HEADLINES LOOK TO BE ON TRACK. WILL CONTINUE CURRENT RED FLAG
WARNINGS AS THEY ARE AS HEADLINES ARE IN GOOD SHAPE. LOOKING AT
LOW AFTERNOON HUMIDITIES ON A DAILY BASIS WEST OF THE LARAMIE
RANGE THROUGH THE WEEK. FORTUNATELY...WINDS LOOK TO BE WEAK AT
LEAST THROUGH THURSDAY BEFORE ANOTHER LOW PRESSURE SYSTEM
APPROACHES FROM THE WEST. COULD BE LOOKING AT CRITICAL FIRE
WEATHER CONDITIONS FRIDAY INTO SATURDAY AS THIS LOW SLOWLY TRACKS
INTO MONTANA.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR WYZ304-306.
NE...NONE.
&&
$$
SHORT TERM...GCC
LONG TERM...RE
AVIATION...RE
FIRE WEATHER...GCC
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
418 AM EDT WED AUG 19 2015
.SYNOPSIS...
DEEP MOISTURE WILL REMAIN ACROSS THE AREA THE AREA TODAY INTO
THURSDAY WITH SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS.
A WEAK FRONT WILL APPROACH THE AREA ON THURSDAY. THE FRONT WILL
DISSIPATE NEAR THE AREA SATURDAY...WITH HIGH PRESSURE RETURNING
FOR SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
OUR REGION WILL RESIDE ALONG THE NORTHERN PERIPHERY OF THE UPPER
RIDGE CENTERED ACROSS FLORIDA INTO THE GULF OF MEXICO. COULD SEE
WEAK SHORT WAVES CROSS THE AREA IN SOUTHWEST FLOW ALOFT. THE AIR
MASS WILL REMAIN QUITE MOIST WITH PWAT VALUES AT OR ABOVE 2 INCHES.
GIVEN POSSIBLE SHORT WAVES...WEAK TO MODERATE INSTABILITY...AMPLE
MOISTURE AND DAYTIME HEATING...WE EXPECT ANOTHER DAY OF SCATTERED
TO NUMEROUS SHOWERS AND THUNDERSTORMS. THE HRRR MODEL HAS ONE AREA
OF CONVECTION EXITING TO THE NORTHEAST EARLY THIS MORNING...THEN
NEXT ROUND MOVING INTO THE REGION FROM THE WEST EARLY THIS
AFTERNOON. HEAVY DOWNPOURS ONCE AGAIN POSSIBLE. SHOWERS AND
THUNDERSTORMS EXPECTED TO LINGER INTO TONIGHT AS A PRE-
FRONTAL TROUGH DEVELOP ACROSS THE CAROLINAS.
KEPT TEMPERATURES CLOSE TO GUIDANCE CONSENSUS WITH HIGHS IN THE
UPPER 80S TO LOWER 90S AND LOWS IN THE LOW TO MID 70S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
OUR WET PATTERN WILL HOLD THURSDAY INTO FRIDAY AS A WEAK COLD
FRONT MOVES INTO THE AREA. PRECIPITABLE WATER WILL REMAIN HIGH
WITH VALUES MAINLY AROUND 2 INCHES. HEAVY DOWNPOURS MAY OCCUR WITH
SOME OF THE THUNDERSTORMS. THE FRONT MAY SLIDE JUST SOUTH AND EAST
OF THE MIDLANDS AND CSRA FRIDAY. HAVE FOLLOWED GUIDANCE TRENDS
WITH HIGH CHANCE POPS FOR THURSDAY THEN LOW CHANCE FOR FRIDAY.
USED THE GUIDANCE CONSENSUS FOR THE HIGH TEMPERATURE FORECAST.
USED THE WARMER LOW TEMPERATURE GUIDANCE BECAUSE OF THE HIGH
MOISTURE.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
THE GFS AND ECMWF DISPLAY A DIFFUSE FRONT STALLED NEAR THE
FORECAST AREA EARLY IN THE MEDIUM-RANGE PERIOD. THE MODELS DISPLAY
ANOTHER FRONT LATE IN THE PERIOD. THE MODELS HAVE UPPER RIDGING
SATURDAY...WITH TROUGHING DURING THE REST OF THE PERIOD. THE
PATTERN SUPPORTS A CONTINUED CHANCE OF SHOWERS AND THUNDERSTORMS.
THE GFS ENSEMBLE MEAN PLUS GFS...ECMWF...AND EKD MOS SUPPORT POPS
OF MAINLY 20 TO 30 PERCENT. ABOVE NORMAL HIGH TEMPERATURES SHOULD
BE ASSOCIATED WITH THE UPPER RIDGING EARLY IN THE PERIOD. THE REST
OF THE PERIOD WILL LIKELY HAVE NEAR NORMAL TEMPERATURES.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
S/W MOVING ACROSS THE AREA OVERNIGHT. AHEAD OF THIS FEATURE A
LINE OF SHOWERS AND SCATTERED THUNDERSTORMS CONTINUES TO MOVE
EAST- NORTHEAST ACROSS THE EASTERN PORTION OF THE CWA. THE
STRONGEST STORMS AREA ACROSS CHESTERFIELD COUNTY AND MOVING INTO
THE PEE DEE/S CNTRL NC.
ALL TAF SITES CURRENTLY REPORTING VFR CONDITIONS. HAVE CONTINUED
THROUGH 07Z THE MENTION OF SHOWERS AT OGB...OTHERWISE EXPECT MAINLY
DRY CONDITIONS FOR THE REMAINDER OF THE NIGHT. WINDS GENERALLY
VARIABLE DUE TO BOUNDARIES ACROSS THE AREA. MODELS DO HINT AT SOME
ENHANCED MOISTURE IN LOW-LEVELS LATE TONIGHT...BUT DO NOT EXPECT ANY
WIDESPREAD FOG DUE TO AN OVERNIGHT LOW-LEVEL JET AND EXPECTED
CLOUDS. CONFIDENCE REMAINS LOW...BUT DID MENTION MVFR BR AT AGS/OGB
TOWARDS MORNING. ADDITIONAL SHOWERS SHOULD ONCE AGAIN FORM THIS
AFTERNOON...WHICH MAY BRING BRIEF RESTRICTIONS TO VISIBILITY AT ALL
TAF SITES.
EXTENDED AVIATION OUTLOOK...A MOIST SOUTHERLY FLOW WILL CONTINUE
THROUGH THURSDAY. THERE WILL BE SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS. STRATUS AND FOG MAY OCCUR DURING THE EARLY MORNING
HOURS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
109 AM EDT WED AUG 19 2015
.PREV DISCUSSION... /ISSUED 1020 PM EDT TUE AUG 18 2015/
UPDATE...
THUNDER KEEPS DIMINISHING ACROSS THE CWFA THIS EVENING. HAVE
TWEAKED POPS ACCORDING TO THE LATEST RADAR TRENDS. THE HRRR KEEPS
ONLY A FEW SHOWERS AROUND OVERNIGHT...SO HAVE LOWERED POPS A BIT.
MODELS ARE A LITTLE SLOWER STARTING THE PRECIP TOMORROW...SO
DELAYED THE ONSET OF THE LIKELY POPS.
PREV DISCUSSION... /ISSUED 343 PM EDT TUE AUG 18 2015/
SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
NO MAJOR CHANGES IN THE OVERALL WET PATTERN IS EXPECTED AS AN ACTIVE
SOUTHWEST FLOW ALOFT CONTINUES TO INTERACT WITH VERY MOIST AND
MODERATELY UNSTABLE ENVIRONMENT TO PRODUCE SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS... MAINLY DURING DAYTIME HEATING BETWEEN
NOON AND 10 PM... WITH MAINLY ISOLATED TO SCATTERED SHOWERS
LINGERING OVERNIGHT.
ALTHOUGH MOST STORMS WILL REMAIN WELL UNDER SEVERE LIMITS... AN
ISOLATED STRONG TO SEVERE STORM CANNOT BE RULED OUT DURING THE LATE
AFTERNOON AND EARLY EVENING HOURS TODAY... AND AGAIN ON WEDNESDAY
AS CAPE VALUES CLIMB INTO THE 2500-3000 J/KG RANGE.
THE GREATER CONVECTIVE CONCERN IS THE POTENTIAL FOR BRIEF FLOODING
AS ENTRENCHED DEEP TROPICAL MOISTURE SUPPORTS LOCALLY HEAVY
DOWNPOURS... EVEN FROM SHOWERS... THAT CAN QUICKLY DUMP 1-3 INCHES
IN A SHORT PERIOD OF TIME. WILL NEED TO MONITOR ANY FLASHY... FLOOD
PRONE CREEKS CLOSELY OVER THE NEXT COUPLE OF DAYS OR MORE.
OTHERWISE... WILL LEAN TOWARD PERSISTENCE FOR TEMPS AS AMPLE LOWS
CLOUDS TONIGHT AND WEDNESDAY NIGHT HOLD LOWS IN THE 70S... AND
WIDESPREAD CONVECTION HELP HOLD HIGHS ON WEDNESDAY MOSTLY IN THE
80S... EXCEPT SOME LOWER 90S IN THE FAR SOUTHERN REACHES.
39
LONG TERM /THURSDAY THROUGH TUESDAY/...
NO MAJOR CHANGES MADE TO THE FORECAST PERIOD AS THE LONG TERM
SOLUTIONS IN DECENT AGREEMENT EXCEPT FOR LATE IN THE PERIOD. GFS
HAS LOWER AMPLITUDE UPPER TROUGH DYNAMICS BY EARLY NEXT WEEK AND
THUS STRUGGLES TO PUSH A FRONT THROUGH BUT HAVE LEANED MORE TOWARD
PREVIOUS FORECAST AND EARLIER ECMWF TO KEEP CONSISTENCY. OTHERWISE
HAVE REFRESHED OTHER FIELDS WITH LATEST BLEND. PREVIOUS DISCUSSION
FOLLOWS...
BAKER
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
PATTERN IN LONG TERM PERIOD TRANSITIONS FROM HIGH AMPLITUDE TROUGH
ALONG THE MS RIVER VALLEY STATES ON WED TO ZONAL FLOW THIS WEEKEND
AND FINALLY WEAK NW FLOW/UPR RIDGE TO THE WEST WITH A HINT OF A
MDT FROPA ON MONDAY. WITH THE FIRST TWO PATTERNS...SE CONUS SHOULD
REMAIN IN MOIST PATTERN WITH DEEP MOISTURE THRU THE WEEKEND. NO
ONE DAY SEEMS TO STAND OUT WITH PRECIP CHCS NOR DO ANY DAYS SEEM
TO HAVE CHC FOR SVR OR EVEN STRONG DEEP CONVECTION. MED RANGE
MODELS IN GOOD AGREEMENT. WPC PREFERRING BLEND OF ALL 00Z
OPERATIONAL MODELS FOR FEATURES AFFECTING CWA THRU DAY 7.
TROPICAL ACTIVITY REMAINS SUBDUED. COLD CORE UPPER LOW OFF
CAROLINA COAST...WHICH HAS PLAYED A ROLE IN CREATING STAGNANT
PATTERN OF LATE AND MAY BECOME TROPICAL IN NATURE...SHOULD GET
PICKED UP BY UPPER TROUGH THIS WEEKEND AND LIFT AWAY FROM EAST
COAST. LOW LATITUDE DISTURBANCE AT 35W LONGITUDE THAT TPC IS
TRACKING COULD DEVELOP INTO A NAMED STORM BUT PROGGED TO REMAIN ON
WESTERLY COURSE WITH MEAGER INTENSITY BY ECMWF AND GFS. BY NO
MEANS A GUARANTEE BUT THATS THE LATEST 411.
SNELSON
&&
.AVIATION...
06Z UPDATE...
A FEW AREAS OF STRATUS HAVE BEGUN TO DEVELOP AND SHOULD BECOME
MOSTLY IFR CIGS BY LATER THIS MORNING...RISING TO VFR BY NOON.
ISOLATED/SCATTERED SHOWERS WILL MOVE INTO THE WESTERN TAF AREAS
THIS MORNING AND BECOMING WIDESPREAD OVER ALL THE FORECAST AREA
THIS AFTERNOON...DIMINISHING AFTER SUNSET. WINDS WILL REMAIN LIGHT
SOUTHWEST THROUGH THE FORECAST EXCEPT GUSTY IN STORMS.
//ATL CONFIDENCE...06Z UPDATE...
LOW TO MEDIUM ON CIGS THIS MORNING
MEDIUM ON TIMING OF SHRA/TSRA
HIGH ON REMAINING ELEMENTS
17
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 89 73 89 73 / 70 70 70 30
ATLANTA 87 73 87 73 / 70 70 70 30
BLAIRSVILLE 81 68 80 66 / 80 80 70 30
CARTERSVILLE 87 72 86 70 / 80 80 70 30
COLUMBUS 89 74 90 75 / 70 70 60 30
GAINESVILLE 85 72 85 72 / 70 70 70 30
MACON 91 74 91 74 / 70 70 60 30
ROME 86 72 85 71 / 80 80 70 30
PEACHTREE CITY 88 72 88 72 / 70 70 70 30
VIDALIA 91 75 92 76 / 70 60 50 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...17
LONG TERM....SNELSON
AVIATION...17
...UPDATE TO AVIATION FORECAST DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 335 PM CDT TUE AUG 18 2015
19Z WATER VAPOR SHOWS A CLOSED UPPER LOW OVER SD WHILE SURFACE OBS
PLACE THE LOW OVER NORTHWEST IA/SOUTHWEST MN BORDER. A STRONG COLD
FRONT EXTENDED SOUTH FROM THE SURFACE LOW THROUGH SOUTHEAST NEB TO
JUST WEST OF SLN. VISIBLE SATELLITE HAS SHOWN SOME BREAKS IN THE
CLOUDS AHEAD OF THE FRONT WHICH HAS ALLOWED TEMPS TO WARM INTO THE
LOWER 80S. THIS WOULD SUPPORT SURFACE BASED CAPE VALUES AROUND
1000J/KG WHILE 0-6 KM SHEAR INCREASES TO AROUND 45 KTS. SO THE
POTENTIAL FOR SEVERE STORMS REMAINS IN PLACE. MODELS SHOW AREA ALONG
AND SOUTH OF I-70 AS THE PLACES THAT SHOULD SEE THE BETTER
INSTABILITY. THEREFORE THINK THIS MAY BE WHERE STRONG TO SEVERE
STORMS DEVELOP THIS AFTERNOON, IF THEY STRENGTHEN. SINCE SURFACE
WINDS HAVE VEERED TO THE SOUTHWEST AHEAD OF THE FRONT, THE POTENTIAL
FOR TORNADOES APPEARS TO REMAIN FAIRLY SMALL. THE RAP AND HRRR,
WHICH HAVE SHOWN A BETTER TIMING FOR THE FRONT, TAKE THE BOUNDARY
EAST OF THE FORECAST AREA BETWEEN 8 AND 9 PM. THE RISK FOR SEVERE
WEATHER SHOULD DIMINISH QUICKLY BEHIND THE FRONT AS COOLER MORE
STABLE AIR COMES IN.
ONCE THE FRONT PASSES EAST, THINK THE REST OF TONIGHT WILL BE FAIRLY
UNEVENTFUL. THERE HAVE BEEN SOME LOWER CLOUDS ACROSS WESTERN NEB
MIST OF THE DAY BUT THE MODELS TEND TO KEEP THE LOWER CLOUDS TO THE
NORTH OVERNIGHT. THEREFORE WITH COLD AIR ADVECTION AND MOST LIKELY
PARTLY CLOUDY SKIES, LOWS IN THE MID AND UPPER 50S LOOKS ON TARGET.
BY LATE TONIGHT AND THROUGH THE MORNING WEDNESDAY, MODELS SWING A
DECENT VORT MAX THROUGH THE BASE OF THE UPPER TROUGH PASSING THROUGH
EASTERN KS. THERE IS NO SIGN OF LOW LEVEL MOISTURE ADVECTION OVER
THE COLD FRONT, BUT THERE IS AN INDICATION OF A SATURATED AIRMASS
ACROSS EAST CENTRAL KS WITH GOOD FRONTOGENESIS AS THE WAVE PASSES
OVERHEAD. BECAUSE OF THIS HAVE CONTINUED WITH SOME CHANCE POPS FOR
RAIN MAINLY OVER EAST CENTRAL KS. THERE SHOULD BE MORE DRY AIR OVER
NORTH CENTRAL AND NORTHEAST KS THAT WILL LIMIT PRECIP CHANCES. THE
COLD AIR ADVECTION WEAKENS THROUGH THE DAY WEDNESDAY, BUT THERE MAY
BE SOME CLOUDS LINGER. THEREFORE HIGHS ARE FORECAST TO TOP OUT IN
THE LOWER AND MID 70S. THIS IS ABOUT 15 DEGREES BELOW NORMAL FOR
THIS TIME OF YEAR.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 335 PM CDT TUE AUG 18 2015
LOWER LEVEL WINDS BACK TO THE WEST WEDNESDAY NIGHT AND THEN
SOUTHWEST INTO THURSDAY NIGHT BRINGING SOME WARMING BACK AND SURFACE
TEMPS SHOULD MODIFY CONSIDERABLY. HAVE KEPT VALUES NEAR TO BELOW
MOS FOR WEDNESDAY NIGHT IN LIGHT WINDS AND CLEAR SKIES. MODELS
TRENDING A BIT COOLER FOR FRIDAY WITH CONTINUED BACKED TO NEAR
SOUTHEAST WITH HIGHS STILL LIKELY CLOSE TO THOSE OF THURSDAY. PRECIP
CHANCES CONTINUE TO LOOK QUITE LOW THROUGH THURSDAY NIGHT. AT LEAST
SOME MOISTURE RETURNS AHEAD OF A WEAK UPPER WAVE FRIDAY...THOUGH
THERE REMAINS TO BE A WIDE DEGREE OF VARIANCE IN BOTH OF THESE
ELEMENTS...WITH A TREND TOWARD LOWER AVAILABLE MOISTURE NOTED. AT
THIS POINT CHANCES FOR ANYTHING MORE THAN ISOLATED PRECIP LOOK LOW.
FOR THE BEGINNING OF THE WEEKEND, RETURN FLOW WILL BE IN PLACE OVER
THE SOUTHERN AND CENTRAL PLAINS AHEAD OF A DEEPENING TROUGH OVER THE
NORTHERN ROCKIES. THIS SYSTEM WILL CONTINUE EASTWARD PROGRESSION
INTO THE DAY SATURDAY AND OVERNIGHT INTO SUNDAY BEFORE IT BECOMES
MORE NEGATIVELY TILTED AND LIFTS THROUGH THE UPPER MISSISSIPPI
VALLEY INTO THE GREAT LAKES REGION BY MONDAY. THIS LARGER SCALE
FEATURE SHOULD BRING ABOUT THE CHANCE OF ELEVATED STORMS FOR
SATURDAY MORNING AS A LLJ SHOULD HELP ENHANCE AN AREA OF ISENTROPIC
LIFT OVER EASTERN KS. INTO THE DAY, SOUNDINGS DO SUGGEST THAT STORM
POTENTIAL MAY BE LIMITED WITH A PRETTY STRONG CAP DEVELOPING OVER
THE REGION. THE BETTER CHANCE FOR THUNDERSTORM REDEVELOPMENT WILL
BE IN THE LATE AFTERNOON INTO THE EARLY EVENING AS SHEAR PROFILES
BECOME A LITTLE MORE ORGANIZED AND WAA INCREASES LOW LEVEL MOISTURE
ALONG WITH INSTABILITY OVER THE REGION. SOME POTENTIAL FOR STRONG
TO SEVERE STORMS COULD EXIST, BUT STILL TOO FAR OUT TO PINPOINT
OVERALL LIKELIHOOD. MODELS SEEM TO BE IN FAIRLY GOOD AGREEMENT FOR
THE MOST PART WITH EASTWARD PROGRESSION OF THE TROUGH. THE GFS
SOLUTION DOES SEEM TO BE THE MORE AGGRESSIVE OF THE SOLUTIONS THOUGH
WITH A DEEPER UPPER LOW AND MORE NORTHERLY PROGRESSION AFTER THE
MONDAY MORNING TIME FRAME. IN THE WAKE OF THIS FALL-LIKE LOOKING
SYSTEM, WILL BE ANOTHER NICE FEW DAYS AS HEIGHTS RISE AND SUBSIDENCE
SETS IN WITH SIGNIFICANT MOISTURE BEING PUSHED SOUTH.
HIGH TEMPS COOL BEHIND THE SYSTEM INTO THE UPPER 70S
AND ONLY CLIMB INTO THE MID 80S BY TUESDAY. LOWS MEANWHILE COULD
FLIRT WITH LOW 50S IN PARTS OF THE AREA BY TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1232 AM CDT WED AUG 19 2015
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...WOLTERS
LONG TERM...65/DRAKE
AVIATION...SANDERS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
122 AM EDT WED AUG 19 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 335 PM EDT TUE AUG 18 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
FROM NRN HUDSON BAY INTO THE NRN PLAINS RESULTING IN A WSW FLOW INTO
THE NRN GREAT LAKES. A LINGERNIG AREA OF 700 MB FGEN AND WEAK
WAA/ISENTROPIC LIFT CONTINUES TO SUPPORT A PERSISTENT CLUSTER OF
SHOWERS OVER SCNTRL UPPER MI INTO EARLY AFTERNOON. UPSTREAM A
VIGOROUS SHRTWV ROTATING OVER SD/NE WILL LIFT TOWARD THE UPPER GREAT
LAKES TONIGHT BRINGING SHRA TO UPPER MI MAINLY TONIGHT INTO EARLY
WED. AT THE SFC...A WEAK FRONTAL BOUNDARY EXTENDED FROM CNTRL IA
THROUGH CNTRAL WI INTO CNTRL LWR MI. WITH HIGH PRES OVER NRN
ONTARIO...LIGHT NE WINDS PREVAILED ACROSS THE NRN LAKES TODAY.
TONIGHT...ATTENTION TURNS TO THE DEVELOPING UNSEASONABLY STRONG LOW
PRES SYSTEM MOVING OUT OF THE PLAINS. THE SD/NE SHRTWV WILL SUPPORT
A DEEPENING LOW MOVING INTO SRN MN BY 00Z/WED AND THEN INTO NRN
WI/SW U.P. BY 12Z/WED AS THE CENTRAL PRESSURE LOWERS NEAR 995 MB
APPROACHING RECORD LEVELS FOR THIS TIME OF YEAR. STRONG MOISTURE
TRANSPORT AND 305K-310K ISENTROPIC ASCENT WILL BRING AN AREA OF RAIN
THROUGH UPPER MI TONIGHT...MAINLY AFTER MIDNIGHT. HOWEVER...THIS
TRANSIENT BAND IS EXPECTED TO BRING QPF AMOUNTS OF ONLY 0.25-0.40
INCHES OVER THE CNTRL AND ERN CWA. THE FAR WEST HAS THE POTENTIAL TO
GET HIGHER AMOUNTS (0.5 TO ONE INCH) CLOSER TO THE STRONGEST DEEP
LAYER QVECTOR CONV AND LIFT WHICH WILL REMAIN TO THE WEST OVER NRN MN
AND WRN LAKE SUPERIOR. WITH MODEST MUCAPE VALUES INTO THE 200- 500
J/KG RANGE ONLY ISOLD TSRA ARE EXPECTED.
WEDNESDAY...SHOWERS WILL BE EXITING N AND E WED MORNING AHEAD OF THE
COLD FRONT AND THEN THE DRY SLOT WITH THE SYSTEM WILL MOVE IN FROM
THE SW WED LATE MORNING/AFTERNOON. ALTHOUGH THERE WILL BE STRONG 0-6
KM SHEAR ALONG THE FRONTAL BOUNDARY...AMOUNT OF INSTABILITY (MODELS
PROJECT 300-600 J/KG) REMAINS IN QUESTION AS THERE COULD BE
CONSIDERABLE CLOUD COVER LINGERING OVER THE AREA. BUT IF SUFFICIENT
INSTABILITY DEVELOPS AHEAD/ALONG THE FRONT...THERE COULD BE SOME
STRONG TO POSSIBLY SEVERE STORMS FORMING OVER MAINLY THE CENTRAL AND
ERN CWA IN THE MORNING. AFTER THE DRY SLOT MOVES INTO MAINLY THE
CENTRAL AND ERN CWA EXPECT SHRA TO GENERALLY DISSIPATE IN THE
AFTERNOON. WRAP AROUND PRECIP/MOISTURE WITH SYSTEM COULD MOVE INTO
WRN UPPER MI LATE IN THE DAY. WED LOOKS WINDY OVER CENTRAL AND ERN
UPPER MI WITH S-SW WINDS GUSTING TO 25-30 MPH.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 251 PM EDT TUE AUG 18 2015
THE ANOMALOUS UPPER TROUGH AND SURFACE LOW (AROUND 3-4 SIGMA) WILL
BE CENTERED BETWEEN DULUTH AND ISLE ROYALE AT THE START OF THE LONG
TERM FORECAST. THESE FEATURES WILL BE SLOWLY LIFTING TO THE
NORTHEAST THROUGH THURSDAY...BRINGING THE POTENTIAL FOR RAIN
SHOWERS AND BREEZY CONDITIONS TO THE AREA DURING THAT PERIOD.
STARTING OFF THE PERIOD...THE MID LEVEL DRY SLOT WILL BE OVER THE
CENTRAL AND EASTERN U.P. AND DON/T EXPECT MUCH MORE THAN LOW CLOUDS
FOR THE EVENING. BUT OVER THE WEST...WRAP AROUND MOISTURE WILL LEAD
TO SCATTERED/NUMEROUS SHOWERS WILL BE OCCURRING AND WILL LIKELY SEE
SOME ASSISTANCE FROM TERRAIN ENHANCEMENT WITH THE WEST-NORTHWEST
WINDS BEHIND THE SURFACE TROUGH THAT WILL BE LOCATED OVER THE
CENTRAL U.P. AT 06Z THURSDAY. AS THAT LOW LIFTS TO THE NORTHEAST
OVERNIGHT WEDNESDAY INTO THURSDAY...EXPECT THE SHOWERS TO SHIFT
EASTWARD BEHIND THE TROUGH AND MOVE OVER THE CENTRAL/EASTERN U.P.
ACCUMULATIONS WILL BE LIGHTER THAN OVER THE WEST WITH LESS TERRAIN
INFLUENCE...BUT SHOULD STILL SEE A FEW HUNDREDTHS BY LATE THURSDAY
AFTERNOON. WITH THE UPPER LOW QUICKLY MOVING TO THE NORTH THURSDAY
AFTERNOON INTO THURSDAY NIGHT...SHOULD SEE THE SHOWER COVERAGE
QUICKLY DIMINISH AS DRIER AIR ASSOCIATED WITH A SURFACE RIDGE MOVING
NORTHEAST INTO THE AREA. HAVE FOLLOWED THAT IDEA BOTH WITH THE POPS
AND CLOUD COVER THURSDAY AFTERNOON AND EVENING. IN FACT...SOME OF
THE AREAS NEAR THE WISCONSIN BORDER MAY HAVE THE LOW CLOUDS SCATTER
OUT BY EARLY AFTERNOON. IN ADDITION TO THE RAIN...EXPECT WINDS TO
INCREASE OVER AT LEAST THE WESTERN HALF OF THE CWA ON WEDNESDAY
NIGHT. THE DIFFERENCES IN THE MODELS LEADS TO SOME UNCERTAINTY IN
THE STRENGTH...BUT IT STILL APPEARS THAT GUSTS UP TO 30KTS ARE
POSSIBLE OVER THE KEWEENAW. FOR THE REST OF THE AREA...EXPECT GUSTS
IN THE 20-25KT RANGE ON THURSDAY.
THE HIGH PRESSURE RIDGE WILL BE NEAR THE AREA (FROM A HIGH IN THE
OHIO RIVER VALLEY) THROUGH FRIDAY NIGHT...BUT EXPECT THE GRADIENT
TO TIGHTEN THROUGH THAT PERIOD AS ANOTHER LOW DEVELOPS IN THE
NORTHERN PLAINS. THAT GRADIENT AND PLENTY OF SUNSHINE SHOULD LEAD TO
DECENT MIXING ON FRIDAY (AROUND 800MB)...RAISING TEMPERATURES TO
NORMAL OR SLIGHTLY ABOVE NORMAL VALUES UNDER OCCASIONALLY GUSTY
SOUTHWESTERLY WINDS (17-23KTS). WITH THE UPPER TROUGH AND SURFACE
LOW STILL NEAR THE NORTHERN PLAINS AND MOVING INTO THE UPPER
MISSISSIPPI VALLEY...EXPECT A SIMILAR DAY ON SATURDAY. HAVE REMOVED
THE POPS OVER THE WEST FOR SATURDAY AND WILL KEEP SKIES MOSTLY
SUNNY. SINCE THE TIGHTENING GRADIENT WILL REMAIN IN PLACE AHEAD OF
THE LOW...EXPECT WINDS TO BE A LITTLE GUSTIER THAN FRIDAY (UP TO
25KTS) AND TEMPERATURES TO BE A FEW DEGREES WARMER.
THE UPPER TROUGH FOR THE SECOND HALF OF THE WEEKEND
WILL MOVE THROUGH THE UPPER GREAT LAKES REGION OVERNIGHT SATURDAY
THROUGH SUNDAY EVENING. MEANWHILE...THE SURFACE LOW WILL LIFT
NORTH-NORTHEAST FROM NORTHWEST MINNESOTA TO FAR NORTHERN ONTARIO.
THIS WILL LEAD TO A SHARP COLD FRONT MOVING EAST ACROSS THE AREA ON
SUNDAY. MODELS SEEM TO BE FOCUSING ON LATE SATURDAY NIGHT AND
SUNDAY MORNING FOR THE FRONT TO MOVE THROUGH AND WILL FOCUS THE
HIGHEST POPS DURING THAT PERIOD (LOW LIKELY) AND QUICKLY RAMP
UP/DOWN ON BOTH SIDES. MODELS NOT SHOWING A WHOLE LOT OF INSTABILITY
AHEAD OF THE FRONT (MUCAPE VALUES ONLY UP TO 500 J/KG)...SO THINK
THAT THE THUNDER THREAT WILL BE LIMITED AND WILL CAP AT CHANCES.
THE COLD FRONT WILL USHER IN ANOTHER PERIOD OF BELOW NORMAL
TEMPERATURES FOR THE START OF NEXT WEEK AS HIGH PRESSURE BUILDS
OVER THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 122 AM EDT WED AUG 19 2015
UNUSUALLY DEEP LOW PRES FOR AUG WILL MOVE FROM SW MN TO NCNTRL LAKE
SUPERIOR DURING THIS FCST PERIOD. ABUNDANT MOISTURE AND SHRA
STREAMING N WITH THIS SYSTEM WILL LEAD TO LIFR CONDITIONS AT
KIWD/KCMX/KSAW OVERNIGHT AHEAD OF WARM FRONT LIFTING N. PASSAGE OF
WARM FRONT/OCCLUDING FRONT WILL THEN BRING IMPROVING CONDITIONS THIS
MORNING/EARLY AFTN. FARTHEST FROM SFC LOW...KSAW WILL SEE BETTER
DRYING AND POTENTIAL FOR IMPROVEMENT TO VFR IN THE AFTN. KCMX MAY
BRIEFLY REACH VFR...BUT MVFR IS MORE LIKELY TO PREVAIL THRU THE
AFTN. KIWD WILL REMAIN MVFR. THERE IS SOME POTENTIAL FOR ISOLD TSTMS
THIS AFTN IN NW AND CNTRL UPPER MI...BUT WITH CONSIDERABLE
UNCERTAINTY IN WHERE TSTMS WILL DEVELOP IF THEY DO...NO TS MENTION
WAS INCLUDED IN FCST. WINDS WILL BECOME GUSTY AFTER FROPA...
ESPECIALLY AT KSAW WHERE GUSTS TO AROUND 25KT ARE EXPECTED.
CONDITIONS WILL DETERIORATE AGAIN THIS EVENING AS LOW-LEVEL MOISTURE
WRAPS BACK INTO THE AREA AFTER THE LOW PASSES. KIWD SHOULD FALL TO
LIFR...KCMX TO IFR AND KSAW TO MVFR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 327 PM EDT TUE AUG 18 2015
AS LOW PRES ORGANIZES AND STRENGTHENS OVER THE PLAINS THIS EVENING
...NE WINDS WILL BEGIN TO INCREASE...ESPECIALLY OVER WRN LAKE
SUPERIOR WHERE GUSTS SHOULD REACH 30KT LATE AFTN/EARLY EVENING. MAY
EVEN BE A FEW GALE GUSTS NEAR APOSTLE ISLANDS EARLY EVENING. THIS
LOW WILL BECOME UNSEASONABLY DEEP FOR AUG AS IT LIFTS ACROSS WRN
LAKE SUPERIOR WED AFTERNOON. 20-30KT WINDS ARE EXPECTED OVER MUCH OF
THE LAKE TONIGHT INTO WED. MAY SEE GALE FORCE GUSTS OVER FAR WRN
LAKE SUPERIOR IN THE NE WINDS AHEAD OF THE LOW TONIGHT AND THEN IN
THE WESTERLY WINDS ACROSS WRN AND CENTRAL LAKE SUPERIOR ON THU AS
THE LOW LIFTS N OF THE AREA. WINDS WILL DIMINISH TO UNDER 20KT BY
FRI...AND THEN BEGIN TO INCREASE SOME AGAIN ON SAT AHEAD OF THE NEXT
COLD FRONT MOVING OUT ACROSS THE PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...VOSS
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
1121 PM CDT TUE AUG 18 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 258 PM CDT TUE AUG 18 2015
VERY POWERFUL LOW PRESSURE MOVING FROM SOUTHWEST MN TO THE ARROWHEAD
REGION BY WEDNESDAY EVENING. IT IS VERY RARE TO SEE SUCH A STRONG
LOW PRESSURE SYSTEM IN THE SUMMER. IN FACT IT MAY WELL RIVAL THE LOW
PRESSURE RECORD FOR MSP. THE HRRR AND HOPWRF ARE IN GOOD AGREEMENT
AND HAVE DONE WELL THE LAST FEW HOURS. RADAR AND OBS SUPPORT THE
IDEA OF LESS PRECIPITATION IN TERMS OF AMOUNTS AND LESS CHANCES FOR
THUNDER AFTER 02Z THIS EVENING ACROSS THE AREA. DRY SLOT REALLY TOOK
OVER FOR THIS EVENT IN SRN MN. EXPECT THE COMMA HEAD WRAP-AROUND
PRECIPITATION TO AFFECT WESTERN MN LATE THIS AFTERNOON AND SLOWLY
LIFT EAST AND NORTH THROUGH THE EVENING AND OVERNIGHT HOURS. MAIN
PRECIPITATION WILL BE OVER WRN MN AND EXTENDING TO THE ARROWHEAD. WE
CAN EXPECT SCATTERED RAIN AND AN ISOLATED SHOWER OVER CENTRAL MN
INTO WRN WI THROUGH THE OVERNIGHT HOURS...MAYBE DRIZZLE. RAIN SHOULD
DIMINISH TOWARD MORNING AND THEN SEE AN INCREASE BY MID DAY.
STRONG WINDS WILL MOVE IN OVERNIGHT WITH GUSTS INTO THE MID 30 MPH
RANGE WEDNESDAY AFTERNOON WITH MOSTLY CLOUDY SKIES AND COOL
TEMPERATURES. VERY MUCH LIKE OCTOBER.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 258 PM CDT TUE AUG 18 2015
PICKING UP THE FORECAST WEDNESDAY NIGHT...THE FOCUS REMAINS GETTING
THIS INCREDIBLY STRONG MID AUGUST SYNOPTIC SCALE STORM SYSTEM OUT OF
HERE. BY THIS POINT...THE SURFACE LOW SHOULD BE POSITIONED OVER
WESTERN LAKE SUPERIOR AND SLIDING NORTHEAST. IT WILL BE ESSENTIALLY
VERTICALLY STACKED AND BEGIN WEAKENING OVERNIGHT. THE HIGHLY
AMPLIFIED 500MB TROUGH WILL INTRODUCE DRY NORTHWESTERLY FLOW INTO
WESTERN MN WHICH WILL EXPAND EASTWARD BY THURSDAY MORNING. DRY AIR
WILL ACCOMPANY THE NORTHWESTERLY FLOW...SO WE`LL SEE THE CLOUDS
BEGIN TO CLEAR FROM WEST TO EAST OVERNIGHT IN WESTERN MN...THROUGH
WESTERN WI BY MIDDAY THURSDAY. WITH CLEARING SKIES...AND THE LOW
MOVING OFF...WE`LL SEE TEMPERATURES REBOUND INTO THE MID 70S FOR
HIGHS. WESTERLY WINDS AT THE SURFACE OF 10-15 MPH ARE EXPECTED
THURSDAY...SO MUCH LESS WINDY THAN WEDNESDAY.
BY FRIDAY...A LOW PRESSURE SYSTEM WILL BE DEVELOPING NEAR
MONTANA...AND WE WILL BE ON THE BACK SIDE OF THE SURFACE RIDGE AXIS
ASSOCIATED WITH A SURFACE HIGH SLIDING EAST FROM THE CENTRAL PLAINS
TOWARD THE OHIO RIVER VALLEY....WHICH MEANS AN INCREASE IN SOUTHERLY
WINDS IS EXPECTED. WIND SPEEDS ARE FORECAST TO BE AROUND 15-20 MPH
WITH GUSTS OVER 20...AND TEMPERATURES WILL WARM INTO THE LOW 80S
ONCE AGAIN. MAYBE MORE NOTICEABLY...WILL BE THE DEW POINTS RISING
INTO THE MID 60S BY FRIDAY AFTERNOON.
FOR THE WEEKEND...THE AFOREMENTIONED SYSTEM IN MONTANA WILL BE THE
FEATURE OF CONCERN. THE SURFACE LOW IS EXPECTED TO PROGRESS
EASTWARD ALONG THE INTERNATIONAL BORDER SATURDAY THROUGH
SUNDAY...BUT A NORTH-SOUTH ORIENTED COLD FRONT WILL BE THE FOCUS FOR
SHOWER AND THUNDERSTORM ACTIVITY TO DEVELOP IN OUR AREA...MOST
LIKELY SATURDAY AFTERNOON THROUGH THE OVERNIGHT HOURS. THIS SHOULD
BE A PROGRESSIVE LINE OF THUNDERSTORMS ALONG THE BOUNDARY...SO BY
SUNDAY MORNING WE SHOULD BE BACK IN DRIER NORTHWESTERLY FLOW AND
COOLER TEMPERATURES. WILL HAVE TO SEE HOW THIS SYSTEM DEVELOPS IN
THE FUTURE MODEL GUIDANCE AS TIMING ISSUES ARE QUITE COMMON THIS
FAR OUT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1120 PM CDT TUE AUG 18 2015
THE LOW PRESSURE IS CENTERED NEAR RWF WITH A WARM FRONT EXTENDING
TO MSP/RNH/EAU. SOUTH OF THE FRONT...CONDITIONS ARE MAINLY VFR BUT
MVFR/IFR CIGS ARE BEGINNING TO DEVELOP IN POCKETS OF SWRN WI AND
SERN MN. FOUR OF THE SIX TAF LOCATIONS ARE NEAR THE WARM FRONT
WHICH LEADS TO A LOW CONFIDENCE FORECAST FOR MUCH OF THE NIGHT AS
THE WARM FRONT LINGERS NEARBY. EVENTUALLY THE LOW WILL TRACK
THROUGH AND MOISTURE ON ITS BACKSIDE WILL BRING CIGS INTO THE
MVFR/IFR RANGE INTO MUCH OF WEDNESDAY.
KMSP...CONDITIONS HAVE RANGED FROM IFR AND NEARLY LIFR NORTH OF
THE FRONT TO VFR WITH THE PASSAGE OF THE WARM FRONT. DON/T
BELIEVE THE FRONT WILL GO TOO FAR WHICH WILL RESULT IN HIGHLY
VARIABLE CONDITIONS TONIGHT. PREVAILING VFR WITH INSTANCES OF IFR
EXPECTED...BEFORE MVFR/IFR CONDITIONS TAKE HOLD BEGINNING LATE
TONIGHT.
/OUTLOOK FOR KMSP/
THU...VFR. WINDS W 10-15 KTS.
FRI...VFR. WINDS S 10-15 KTS.
SAT...VFR WITH MVFR/TSRA POSSIBLE LATE. WIND S AT 15G20 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...DRL
LONG TERM...SPD
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
407 AM CDT WED AUG 19 2015
.SHORT TERM: (THROUGH TONIGHT)
ISSUED AT 306 AM CDT WED AUG 19 2015
A STOUT COLD FRONT WAS SWEEPING THROUGH THE REGION EARLY THIS
MORNING. AT 08Z, THE FRONT STRETCHED FROM ITS PARENT CYCLONE OVER
SRN MN SEWD THROUGH ERN IA, THEN CURVED BACK SWWD THROUGH MO AND
INTO SERN KS AND NRN OK. WATER VAPOR IMAGERY AND RAP PV ANALYSES
DEPICT A SECONDARY VORT MAX DIVING INTO THE BASE OF THE TROUGH,
WHICH IS CONSISTENT WITH MODEL GUIDANCE. LARGE SCALE ASCENT AHEAD
OF THIS FEATURE WILL SUPPORT PERIODS OF SH/TS TODAY INTO TONIGHT.
PRECIPITATION SHOULD TAPER OFF TONIGHT IN THE WAKE OF THE
AFOREMENTIONED VORT MAX.
WED NIGHT/EARLY THU MORNING LOWS IN THE 50S WILL BE AROUND 10
DEGREES BELOW AVERAGE.
KANOFSKY
.LONG TERM: (THURSDAY THROUGH TUESDAY)
ISSUED AT 306 AM CDT WED AUG 19 2015
SURFACE HIGH PRESSURE BUILDS INTO THE SOUTHERN PLAINS ON THU AND
GRADUALLY SHIFTS EWD WITH TIME. THIS WILL KEEP COOLER/DRIER
CONDITIONS AND WESTERLY WINDS IN PLACE ACROSS MOST OF THE CWA ON
THU/FRI UNTIL THE SURFACE HIGH HAS SHIFTED FAR ENOUGH EAST FOR
WINDS TO TURN SLY AROUND ITS BACK SIDE. RETURN FLOW SETS UP
FARTHER WEST ACROSS THE PLAINS ON THU NIGHT/FRI AHEAD OF THE NEXT
LOW PRESSURE SYSTEM WHICH WILL BE CROSSING FROM THE PACIFIC NW
INTO THE PLAINS OVER THE WEEKEND. THIS SYSTEM WILL BRING THE NEXT
CHANCE FOR SH/TS TO THE LSX CWA OVER THE WEEKEND. ANOTHER STOUT
COLD FRONT IS EXPECTED TO MOVE ACROSS THE CWA ON SUN AND THEN
SETTLE SOUTH OF THE CWA EARLY NEXT WEEK. TEMPERATURES WILL DIP
BELOW AVERAGE AGAIN IN THE WAKE OF THIS FRONT.
KANOFSKY
&&
.AVIATION: (FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1159 PM CDT TUE AUG 18 2015
COMPLEX OF THUNDERSTORMS OVER CENTRAL MISSOURI WILL MOVE INTO THE
ST. LOUIS METRO TAF SITES AROUND 06Z PRODUCING MVFR AND POSSIBLY
BRIEF IFR VISIBILITIES AS WELL AS GUSTY WINDS THROUGH 08Z BEFORE
THE THUNDERSTORMS MOVE OFF TO THE EAST. COLD FRONT WILL MOVE
THROUGH KUIN AND KCOU AROUND 09Z AND THE ST. LOUIS METRO TAF SITES
AROUND 12Z. CEILINGS WILL BE HIGH MVFR OR LOW VFR WITH THE PASSAGE
OF THE COLD FRONT INTO THE MORNING HOURS. EXPECT RAIN TO DEVELOP
DURING THE MORNING HOURS AT KCOU AND AT THE ST. LOUIS METRO TAF
SITES WITH SCATTERED SHOWERS AROUND QUINCY. RAIN SHOULD END BY
LATE IN THE DAY.
SPECIFICS FOR KSTL:
EXPECT THUNDERSTORMS WITH VISIBILITIES AS LOW AS IFR TO AFFECT
THE TERMINAL THROUGH 08Z. CEILINGS WILL BE LOW MVFR OR HIGH VFR
WITH THE PASSAGE OF A COLD FRONT AROUND 12Z. THEN RAIN WILL MOVE
INTO THE AREA BY MID MORNING AND LAST MOST OF THE DAY BEFORE
ENDING BY 00Z.
BRITT
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1200 AM CDT WED AUG 19 2015
.SHORT TERM: (THROUGH LATE TONIGHT)
ISSUED AT 355 PM CDT TUE AUG 18 2015
PREFRONTAL CONVECTION HAS BLOWN UP ABOUT AS EXPECTED THIS AFTERNOON.
SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 900 PM THIS EVENING AND
WE`VE HAD SOME SPORADIC REPORTS OF TREE LIMBS DOWN WITH THE
STRONGEST STORMS. SBCAPE IN EXCESS OF 3000 J/KG INDICATED ON SPC
MESOANALYSIS PAGE AHEAD OF THE CONVECTION WITH A VIGOROUS SHORTWAVE
MOVING INTO WESTERN MISSOURI AT THIS TIME. MASS FIELDS ON SHORT-
RANGE GUIDANCE CONTINUE TO STREAM INSTABILITY UP INTO THE REGION
THROUGH THE EVENING...AND THIS LOOKS REASONABLE GIVEN THE POSITION
OF THE SHORTWAVE AND SURFACE FRONT. HAVE TO SAY, THE HRRR DID A
PRETTY GOOD JOB WITH THE CONVECTION THIS AFTERNOON, SO THE SHORT
RANGE FORECAST FOR TONIGHT IS BIASED HEAVILY TOWARD THE HRRR.
EXPECT STORMS CURRENTLY OVER EASTERN KANSAS TO CONTINUE TO DEVELOP
AND MOVE EASTWARD TONIGHT AHEAD OF THE SHORTWAVE. THERE WILL LIKELY
BE A LUL IN THE THUNDERSTORM ACTIVITY OVER OUR CWFA AFTER 00-02Z,
BUT THE STORMS CURRENTLY IN KANSAS WILL EVENTUALLY MOVE IN AFTER 04-
05Z. ADDITIONAL DEVELOPMENT IS ALSO POSSIBLE AHEAD OF THE KANSAS
STORMS. THE COLD FRONT WILL SWEEP INTO MISSOURI OVERNIGHT AND SHOULD
BE THROUGH CENTRAL AND INTO EASTERN MISSOURI BY 12Z.
CARNEY
.LONG TERM: (WEDNESDAY THROUGH NEXT TUESDAY)
ISSUED AT 355 PM CDT TUE AUG 18 2015
MODELS CONTINUE TO SUPPORT A FAST SURFACE FRONTAL SOLUTION WHILE
MAINTAINING A SIMILAR TIMING WITH THE UPPER LEVEL PROFILE. WHILE
THERE SHOULD STILL BE A NICE SLUG OF WIDESPREAD LIFT BUILDING IN
FROM LATE WEDNESDAY MORNING THRU EARLY EVENING...THE COLUMN WILL
BE VERY LIMITED THERMODYNAMICALLY...MEANING LIKE MOSTLY SHOWERS WITH
DIMINISHING CHANCES FOR THUNDER AS THE DAY GOES ALONG. DECENT RAIN
CHANCES ARE NOW EXPECTED TO LINGER INTO EARLY EVENING BEFORE THEN
MAKING A RAPID EXIT FROM SOUTHWEST TO NORTHEAST FOLLOWED QUICKLY BY
CLEARING SKIES.
WHAT WILL REMAIN IN ITS WAKE WILL BE A RARE COOL AND DRY PERIOD
BEGINNING LATE WEDNESDAY NIGHT THRU FRIDAY AFTERNOON WITH MIN TEMPS
DIPPING INTO THE 50S AND MAX TEMPS ONLY REACHING TO AROUND 80
DEGREES.
THE FRONTAL COMPLEX THAT HAD PUSHED TO OUR SOUTH ON WEDNESDAY
WILL THEN MOVE BACK TO THE NORTH BY SATURDAY TO ALLOW CHANCES FOR
THUNDERSTORMS TO RETURN AND PERSIST THRU THE WEEKEND WITH
TEMPERATURES BACK TO SEASONABLE AVERAGES.
IN YET ANOTHER SIGN THAT AUTUMN IS NOT TOO FAR OFF ANYMORE...ANOTHER
DECENTLY STRONG COLD FRONT PUSHES THRU LATE SUNDAY AND IS
EXPECTED TO BRING AN ENCORE OF THE COOL AND DRY PERIOD FOR MONDAY
AND TUESDAY OF NEXT WEEK.
SOME MODEL DISCREPANCIES THEN EXIST HEADING DEEPER INTO NEXT WEEK
BUT THE GENERAL THEME IS SUMMER THEN REMINDING US THAT IT IS NOT YET
DONE...WITH AN UPPER LEVEL RIDGE ATTEMPTING TO BUILD IN TO POSSIBLY
DELIVER ONE FINAL ROUND OF DANGEROUS HEAT AND HUMIDITY TO CLOSE OUT
AUGUST.
TES
&&
.AVIATION: (FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1159 PM CDT TUE AUG 18 2015
COMPLEX OF THUNDERSTORMS OVER CENTRAL MISSOURI WILL MOVE INTO THE
ST. LOUIS METRO TAF SITES AROUND 06Z PRODUCING MVFR AND POSSIBLY
BRIEF IFR VISIBILITIES AS WELL AS GUSTY WINDS THROUGH 08Z BEFORE
THE THUNDERSTORMS MOVE OFF TO THE EAST. COLD FRONT WILL MOVE
THROUGH KUIN AND KCOU AROUND 09Z AND THE ST. LOUIS METRO TAF SITES
AROUND 12Z. CEILINGS WILL BE HIGH MVFR OR LOW VFR WITH THE PASSAGE
OF THE COLD FRONT INTO THE MORNING HOURS. EXPECT RAIN TO DEVELOP
DURING THE MORNING HOURS AT KCOU AND AT THE ST. LOUIS METRO TAF
SITES WITH SCATTERED SHOWERS AROUND QUINCY. RAIN SHOULD END BY
LATE IN THE DAY.
SPECIFICS FOR KSTL:
EXPECT THUNDERSTORMS WITH VISIBILITIES AS LOW AS IFR TO AFFECT
THE TERMINAL THROUGH 08Z. CEILINGS WILL BE LOW MVFR OR HIGH VFR
WITH THE PASSAGE OF A COLD FRONT AROUND 12Z. THEN RAIN WILL MOVE
INTO THE AREA BY MID MORNING AND LAST MOST OF THE DAY BEFORE
ENDING BY 00Z.
BRITT
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
120 AM EDT WED AUG 19 2015
.SYNOPSIS...
UNSETTLED WEATHER WILL CONTINUE THROUGH MID WEEK AS TROPICAL
MOISTURE STREAMS INTO THE AREA AHEAD OF AN APPROACHING COLD
FRONT. THE FRONT WILL REACH THE COASTAL CAROLINAS BY FRIDAY AND
OFFSHORE OVER THE WEEKEND. ANOTHER COLD FRONT IS EXPECTED TO
REACH THE AREA TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 120 AM WEDNESDAY...ONE AREA OF SHOWERS WAS BRUSHING
MARLBORO AND ROBESON COUNTIES. OTHER SLOW MOVING SHOWERS AND
THUNDERSTORMS WERE MOVING ACROSS CENTRAL PORTIONS OF THE
CAROLINAS. THIS ACTIVITY WAS AHEAD OF A MID LEVEL SHORTWAVE WHICH
WILL BE MOVING ACROSS THE AREA OVERNIGHT.
WE DO EXPECT MAINLY ISOLATED THUNDERSTORMS AND SHOWERS TO PERSIST
AS THEY MOVE INTO WESTERN PORTIONS OF THE FORECAST AREA
OVERNIGHT. HOWEVER...THE HIGH RESOLUTION HRRR CONTINUES TO SHOW
THIS ACTIVITY WANING WITH TIME WHILE CONVECTION EVENTUALLY
BLOSSOMS ACROSS THE WATERS. THIS IS SIMILAR TO WHAT TRANSPIRED
LAST NIGHT. WILL SHOW LOW POPS...SMALL CHANCE/SLIGHT CHANCE FOR
THE REMAINDER OF THE NIGHT. HOWEVER... WILL TREND POPS HIGHER NEAR
THE IMMEDIATE COAST AS THE FLOW SHOULD ALLOW SOME OF THE LATE
NIGHT OCEAN SHOWERS AND THUNDERSTORMS TO BRUSH THE MORE IMMEDIATE
COAST.
STRATUS WAS BEGINNING TO EXPAND ACROSS THE EASTERN CAROLINAS LATE
THIS EVE. I HAVE INCLUDED PATCHY FOG FOR A GOOD PORTION OF THE
AREA. INLAND AREAS ARE FAVORED OVER THE MORE IMMEDIATE COAST DUE
TO THE MORE SIGNIFICANT RAINFALL THERE TODAY. ALTHOUGH A
DEVELOPING NOCTURNAL JET MAY FAVOR LOW STRATUS OVER FOG...THE
20-30 KT WINDS ABOVE THE BOUNDARY LAYER SHOULD BE RATHER SHORT-
LIVED.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...MID TO UPPER LEVEL RIDGE ALIGNED UP THE
SOUTHEAST COAST SANDWICHED BETWEEN UPPER LOW WELL OFF SHORE AND
TROUGH EXTENDING DOWN FROM THE GREAT LAKES WELL WEST OF OUR AREA.
THIS MID TO UPPER TROUGH WILL PUSH A COLD FRONT EAST INTO THE
CAROLINAS BEFORE IT LIFTS OFF TO THE NORTHEAST INTO CANADA BY
THURS NIGHT. PLENTY OF DEEP MOISTURE WILL STREAM INTO THE AREA
AHEAD OF THIS SYSTEM AND WILL COMBINE WITH MINOR SHORTWAVE ENERGY
AND LOCALIZED CONVERGENCE ALONG PIEDMONT TROUGH...SEA BREEZE AND
THE COLD FRONT UPSTREAM TO PRODUCE GREATER COVERAGE OF CLOUDS AND
CONVECTION THROUGH MID WEEK. LOCAL AREA WILL REMAIN ON THE TOP OF
THE RIDGE WITH A FLATTER W-SW FLOW ALOFT WHICH WILL AID IN
ADVECTING PLENTY OF DEBRIS CLOUDS AND STEERING CONVECTION TOWARD
THE LOCAL FORECAST AREA. MOISTURE PROFILES SHOW THE BRUNT OF THIS
MOISTURE IN THE MID TO UPPER LEVELS AS PLENTY OF MID TO HIGH LEVEL
DEBRIS CLOUDS STREAM INTO AREA. PCP WATER VALUES REMAIN ABOVE 2
INCHES THROUGH THE PERIOD. BY LATE THURS THE COLD FRONT SHOULD
DROP FAR ENOUGH SOUTH INTO THE COASTAL CAROLINAS BUT IT SHOULD
BEGIN TO LAY DOWN AND SLOW DOWN OUT AS THE UPPER FLOW FLATTENS
FURTHER AS MID TO UPPER TROUGH LIFTS OFF INTO CANADA. SOUTHERLY
SFC WINDS WILL BEGIN TO VEER AROUND TO THE WEST BY THURS. THIS
WILL PRODUCE A DEEPER DOWNSLOPE FLOW AND WILL HELP TO BREAK UP THE
CLOUDS AND PRODUCE WARMER TEMPS. BUT IT WILL ALSO ENHANCE LIFT AND
POTENTIAL FOR THUNDERSTORMS ACROSS THE AREA...ESPECIALLY CLOSER TO
THE COAST. EXPECT TEMPS TO REACH UP INTO THE MID TO UPPER 80S ON
WED AND INTO THE 90S MOST PLACES ON THURS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 300 PM TUESDAY...A SLOW MOVING COLD FRONT LOOKS TO PUSH
THROUGH ON FRIDAY. WITH MID LEVEL RIDGING AHEAD OF THIS FEATURE
AND FAIRLY WEAK LOW LEVEL MOISTURE FLUX IT DOESN`T APPEAR THAT
THERE WILL BE MUCH RAIN QUANTITATIVELY EVEN THOUGH FORECAST
RAINFALL CHANCES MAY BE HIGHER THAN CLIMATOLOGY. THIS BOUNDARY
APPEARS TO STALL CLOSE ENOUGH TO THE COAST FOR SOME SMALL RAIN
CHANCES MAINLY ALONG THE BEACHES. SUNDAY AND MONDAY WILL BRING THE
LOWEST RAIN CHANCES OF THE PERIOD BUT WITH A LITTLE BIT OF
LINGERING LOW LEVEL MOISTURE ITS TOUGH TO GO WITH A COMPLETELY DRY
FORECAST. THEY SHOULD RAMP UP AGAIN ON TUESDAY WITH THE APPROACH
OF ANOTHER COLD FRONT. THIS NEXT FRONT MAY ALSO LACK MUCH IN THE
WAY OF MOISTURE FLUX BUT MAY HAVE BETTER UPPER LEVEL SUPPORT FOR
PRECIP GENERATION.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 06Z...PATCHES OF IFR INLAND THROUGH 13Z-15Z. ISOLATED
CONVECTION MAINLY OVER THE WESTERN PORTION OF THE CWA. SOME PATCHY
STRATUS IS LIKELY OVER MUCH OF THE REGION WITH WINDS AT 1K FEET
AROUND 20 KTS. CONVECTIVE DEBRIS WILL KEEP CEILINGS IN THE MID
CLOUD RANGE...WITH PATCHY IFR CIGS. IF WE MANAGE TO GET SOLAR
INSOLATION DURING THE DAY TODAY...CONVECTION COULD BE STRONGER
THAN TODAY WITH MORE COVERAGE.
EXTENDED OUTLOOK...SCATTERED CONVECTION IS EXPECTED THROUGH THE
PERIOD...MOST ACTIVE WEDNESDAY AND THURSDAY WITH BRIEF IFR
CONDITIONS POSSIBLE.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 120 AM WEDNESDAY...SW WINDS WILL PERSIST FOR THE REMAINDER
OF THE NIGHT AT UP TO AROUND 15 KT. SEAS WILL BE 2 TO 3 FT. A 9 TO
10 SECOND EASTERLY SWELL WAS BEING OBSERVED AT THE BUOYS.
A WEAK TROUGH OF LOW PRESSURE ACROSS THE INLAND CAROLINAS AND
BERMUDA HIGH PRESSURE WILL BETTER DEFINE THE PRESSURE GRADIENT...
ESPECIALLY ON WED. WE DO EXPECT SHOWERS AND THUNDERSTORMS TO BEGIN
BLOSSOMING ACROSS THE WATERS AFTER MIDNIGHT. MARINERS SHOULD
EXPECT REDUCED VISIBILITY IN HEAVY RAIN WITH THIS ACTIVITY.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...WEAK RETURN FLOW ON WEDNESDAY WILL VEER TO
THE S-SW ON THU AS COLD FRONT REACHES INTO THE CAROLINAS. THIS
WILL PRODUCE A SLIGHT TIGHTENING OF GRADIENT AND ALLOW WINDS TO
INCREASE UP TO 15 KT LATE WED INTO THU. THIS SLIGHT INCREASE IN
WINDS WILL PRODUCE ENOUGH SOUTHERLY PUSH TO INCREASE SEAS JUST
ABOVE 3 FT.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 300 PM TUESDAY...A COLD FRONT DROPS INTO THE AREA. THIS
BOUNDARY WILL BE FAIRLY SLOW MOVING AND ALSO DECELERATING MAKING
FOR A VERY GRADUAL WIND SHIFT ACROSS THE WATERS WHILE SEAS REMAIN
CAPPED AT 2 FT. E TO NE WINDS ON SATURDAY EXPECTED TO STAY 10 KT
OR LESS BEHIND THE BOUNDARY AND NO CHANGE IN WAVE HEIGHT EVEN IF
THE FROPA SLIGHTLY STEEPENS WAVE FACES FOR A BRIEF TIME. THE
BOUNDARY REMAINS JUST TO OUR SOUTH IN A DISSIPATING STATE BY
SUNDAY AND IT MAY IN FACT BE TOUGH TO FIND ON SURFACE MAPS. THE
HIGH THAT HAD BEEN BUILDING IN BEHIND IT WEAKENS RAPIDLY WITH THE
NET LOCAL RESULT LITTLE CHANGE IN WIND OR WAVES FROM THOSE OF
SATURDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RJD/MJC
SHORT TERM...RGZ
LONG TERM...MBB
AVIATION...DL/8
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1221 AM CDT WED AUG 19 2015
.UPDATE...
ISSUED AT 1216 AM CDT WED AUG 19 2015
A FEW MINOR CHANGES WERE MADE TO THE PRECIPITATION FORECAST AND
TEMPERATURES.
ISOLATED SHOWERS CONTINUE ACROSS WESTERN AND CENTRAL NORTH DAKOTA.
THE HRRR AND RAP CONTINUE THESE SHOWERS THROUGH THE NIGHT.
THEREFORE...EXTENDED BY SPATIALLY AND TEMPORALLY PRECIP CHANCES
WEST AND CENTRAL. A BAND OF STEADY RAIN CONTINUED ACROSS SOUTHEAST
NORTH DAKOTA. THIS BAND WILL SLOWLY MOVE OUT BY DAYBREAK.
TEMPERATURES WERE FALLING A LITTLE FASTER THAN PREVIOUSLY FORECAST
ACROSS THE NORTH WHERE CLOUDS HAVE THINNED OUT. LOWERED OVERNIGHT
LOWS A FEW DEGREES.
UPDATE ISSUED AT 935 PM CDT TUE AUG 18 2015
SHOWERS AND ISOLATED THUNDERSHOWERS IN WESTERN NORTH DAKOTA WERE
DIMINISHING THIS PAST HOUR AFTER SUNSET. EXPECT ONLY ISOLATED LIGHT
SHOWERS IN THE NEXT HOUR OR TWO IN THE WEST.
MEANWHILE THE SURFACE LOW HAD MOVED NORTHEASTWARD INTO SOUTHERN
MINNESOTA IN THE PAST FEW HOURS. THE RAIN SHIELD ASSOCIATED WITH THE
WRAP AROUND PRECIPITATION WAS PERSISTING OVER EASTERN PORTIONS OF
LAMOURE AND DICKEY COUNTIES. EXPECT THESE SHOWERS TO END FROM WEST
TO EAST BY LATE EVENING OR SHORTLY AFTER MIDNIGHT.
OTHERWISE...ADJUSTED HOURLY TEMPERATURES BASED ON LATEST TRENDS.
CURRENT FORECAST REMAINS ON TRACK.
UPDATE ISSUED AT 631 PM CDT TUE AUG 18 2015
CURRENTLY...A SURFACE LOW WAS OVER THE BORDER OF
IOWA/MINNESOTA/SOUTH DAKOTA...WITH HIGH PRESSURE OVER THE FRONT
RANGE OF MONTANA. THE UPPER LEVEL LOW WAS OVER EASTERN SOUTH DAKOTA.
A LARGE AREA OF RAIN SHOWERS CONTINUED NORTH AND WEST OF THE SURFACE
LOW...WHERE OVERCAST SKIES WERE KEEPING TEMPERATURES IN THE 50S AND
60S...AS IN THE JAMES VALLEY. FARTHER WEST WHERE THERE WERE BREAKS
IN THE OVERCAST...TEMPERATURES WERE IN THE UPPER 60S AND INTO THE
70S. ALSO OVER WESTERN NORTH DAKOTA THERE WAS ENOUGH SURFACE HEATING
AND UPPER LEVEL INSTABILITY FOR SOME ISOLATED TO SCATTERED SHOWERS
AND THUNDERSTORMS. NO SEVERE WEATHER EXPECTED WITH THESE
STORMS...WITH UPPER LEVEL SUPPORT MINIMAL...AND WEAK SHEAR.
ONLY CHANGE IN THIS UPDATE WAS TO INCREASE PRECIP CHANCES IN
LAMOURE/DICKEY/MCINTOSH COUNTIES WITH CURRENT RADAR LOOPS INDICATING
MORE COVERAGE IN SHOWERS. MINOR HOURLY TEMPERATURE ADJUSTMENTS AS
WELL.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 311 PM CDT TUE AUG 18 2015
CURRENT SURFACE ANALYSIS PLACES LOW OVER NORTHWESTERN IOWA INTO
SOUTHWESTERN MINNESOTA WITH HIGH PRESSURE WORKING INTO THE LEE OF
THE NORTHERN ROCKIES. UPPER LEVEL ANALYSIS PLACES CUT OFF LOW OVER
EASTERN SOUTH DAKOTA WITH RIDGE OFF THE WEST COAST. BROAD AREA OF
RAINFALL CONTINUES OVER NORTHEAST SOUTH DAKOTA WITH THIS SYSTEM
WITH SOME PRECIPITATION ON THE NORTHERN FRINGES CONTINUING OVER
THE SOUTHERN JAMES RIVER VALLEY. WEAK SHORT WAVE NOTED IN
CYCLONIC FLOW BEHIND THE LOW IS RESULTING IN SOME
SHOWERS/THUNDERSTORMS OVER WESTERN NORTH DAKOTA.
FOR THE REST OF THIS AFTERNOON INTO THIS EVENING...UPPER LOW WILL
SLOWLY LIFT TOWARDS THE NORTHEAST WITH RAIN OVER THE SOUTHERN
JAMES RIVER VALLEY SLOWLY TAPERING OFF FROM WEST TO EAST. AS FOR
THE PRECIPITATION OVER WESTERN NORTH DAKOTA...LATEST HIGH-RES
GUIDANCE SUGGESTS THAT IT SHOULD BE DIMINISHING BY AROUND MID-
EVENING. OTHERWISE...A COOL NIGHT IS IN STORE WITH MOST LOCATIONS
DIPPING INTO THE 40S.
ON WEDNESDAY...UPPER LOW LIFTS OVER MINNESOTA WITH RIDGING
DEVELOPING OVER OUR AREA. EXPECT DRY CONDITIONS WITH TEMPERATURES
REMAINING AROUND 10 DEGREES BELOW AVERAGE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 311 PM CDT TUE AUG 18 2015
WARMING TEMPERATURES AND THUNDERSTORM CHANCES FRIDAY AFTERNOON
THROUGH SATURDAY HIGHLIGHT THE EXTENDED RANGE.
FOR WEDNESDAY NIGHT...AN UPPER LEVEL LOW LOCATED OVER NORTHERN
MINNESOTA WILL CONTINUE TO PUSH EAST WITH A RIDGE BUILDING FROM
THE WEST...KEEPING THE DAKOTAS IN NORTHWEST FLOW WITH DIMINISHING
CLOUDS. TEMPERATURES WILL BEGIN TO WARM ON THURSDAY...WITH HIGHS
GENERALLY REACHING INTO THE 80S AS WE START TO TRANSITION INTO A
BRIEF PERIOD OF NEAR ZONAL FLOW.
A POTENT SHORTWAVE TROUGH WILL APPROACH THE COUNTY WARNING AREA
FROM THE PACIFIC NORTHWEST BY LATE FRIDAY AFTERNOON...BRINGING
WITH IT HIGH TEMPERATURES NEAR 90...MOISTURE RETURN...AND
SOUTHWEST FLOW. AN ASSOCIATED COLD FRONT WILL MAKE ITS WAY ACROSS
THE REGION OVERNIGHT FRIDAY AND INTO SATURDAY...BRINGING CHANCES
OF SCATTERED SHOWERS AND THUNDERSTORMS. AS FAR AS SEVERE WEATHER
CHANCES GO...THERE IS STILL QUITE A BIT OF UNCERTAINTY. TODAYS 12Z
ECMWF IS A BIT QUICKER WITH THE UPPER LEVEL WAVE PROPAGATION...AND
IS MORE ROBUST WITH MOISTURE RETURN/INSTABILITY WHEN COMPARED WITH
THE 12Z GFS. THEREFORE...STRONG TO SEVERE STORMS WOULD BE MORE
LIKELY LATE FRIDAY AFTERNOON AND INTO SATURDAY IF THE EUROPEAN
SOLUTION WERE TO VERIFY. WILL HAVE TO WATCH MODEL TRENDS AS THE
TIME FRAME GROWS CLOSER.
SATURDAY WILL FEATURE ANOTHER COOL DOWN AFTER THE FRONTAL
PASSAGE...WITH SOME LINGERING SHOWERS AND THUNDERSTORMS POSSIBLE
INTO SUNDAY. THE WESTERN RIDGE WILL BEGIN TO BUILD EAST AGAIN AT
THE BEGINNING OF WEEK...PROMOTING ANOTHER WARMUP FOR THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1216 AM CDT WED AUG 19 2015
VFR CONDITIONS AT ALL TAF SITES THROUGH THE TAF PERIOD. ISOLATED
SHOWERS ARE POSSIBLE AT KDIK/KBIS LATE TONIGHT...BUT COVERAGE AND
CONFIDENCE NOT HIGH ENOUGH TO WARRANT MENTION IN THE TAF.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AJ
SHORT TERM...JJS
LONG TERM...ZH
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1149 PM CDT TUE AUG 18 2015
.UPDATE...
ISSUED AT 1146 PM CDT TUE AUG 18 2015
HRRR AND OTHER MODELS CONTINUE TO INDICATE THE POP GRADIENT AND NW
EDGE OF RAIN IN GOOD SHAPE IN THE GRIDS AND NO FURTHER CHANGES
REQUIRED.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 242 PM CDT TUE AUG 18 2015
FORECAST CHALLENGE FOR TONIGHT IS WHICH HI RES MODEL TO FOLLOW FOR
EVOLUTION OF LOW PRESSURE SYSTEM OVER FAR SERN SD AS IT MOVES
EAST AND THEN NORTH...CLIPPING SOUTHERN AND EASTERN PORTIONS OF
THE CWA. HRRR HAS CONSISTENTLY VERIFIED WITH PLACEMENT OF PRECIP
BEST EACH HOUR...ALTHOUGH EARLIER RUNS THAT SPREAD RAIN AS FAR
NORTH AS FARGO WERE THOUGHT TO BE OVERLY BULLISH AND I HAD FAVORED
THE NMM/ARW...WHICH KEPT PRECIP FURTHER SOUTH WITH THE NE FLOW IN
SFC-H850 LAYER. HOWEVER...15Z HRRR RUN DID A VERY GOOD JOB WITH
PLACEMENT OF PRECIP VERIFIED BY 19Z RADAR IMAGERY. THEREFORE WILL
CONTINUE HRRR TRENDS THROUGH THE EVENING THROUGH 06Z...THEN A FCST
BLEND THROUGH END OF EVENT FOR OUR CWA.
TONIGHT AND TOMORROW...PRECIP OVER SOUTHWEST MN WILL CONTINUE TO
LIFT FROM SW MN INTO W CNTRL MN...HOWEVER WITH SFC LOW MOVING
NE...DO NOT EXPECT RAIN TO LIFT MUCH FURTHER NORTH THAN HILLSBORO
WITHIN THE RRV. LOW BEGINS TO LIFT MORE NORTHWARD AFTER
MIDNIGHT...EVENTUALLY MOVING OVER LAKE SUPERIOR WED AFTN. QUESTION
IS HOW MUCH PRECIP WILL BACK INTO NW MN...AND CURRENT TRENDS ARE
KEEPING MOST OF THE NORTHERN VALLEY AND KITTSON/MARSHALL/NW POLK
COUNTIES DRY. 00Z ECMWF WAS THE FURTHEST WEST AND HAVE DISCOUNTED
IT...PREFERRING A GFS/GEM/NAM BLEND FOR WEDNESDAY POPS. HIGHEST
RAINFALL RATES WITHIN DEFORMATION ZONE SHOULD BE OVER CNTRL
MN...WHERE HPC QPF IS SHOWING UP TO TWO AND A QUARTER INCHES OF
PRECIP WITH A SHARP...DECLINING GRADIENT WESTWARD INTO THE
SOUTHERN VALLEY. CURRENT PRECIP TOTAL THOUGHTS ARE AROUND HALF AN
INCH IN FARGO...LITTLE IF ANY IN GRAND FORKS...RISING TO AROUND 2
INCHES AS FAR EAST AS PARK RAPIDS.
WED NIGHT...SYSTEM PULLS OUT OF LAKE SUPERIOR REGION INTO CNTRL
ONTARIO...SLOWLY PULLING PRECIP OUR OF FAR EAST AND NORTHEASTERN
ZONES BY 12Z THU. CLEARING IN THE WEST...IN ADDITION TO RELAXING
PRESSURE GRADIENT WINDS...WILL ALLOW OVERNIGHT LOWS TO FALL INTO
THE UPPER TO MID 40S ACROSS MOST OF THE REGION...WARMEST IN THE
FAR EAST WHERE CLOUD COVER WILL LINGER OVERNIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 242 PM CDT TUE AUG 18 2015
THURSDAY AND FRIDAY...HIGH PRESSURE MOVES INTO REGION BRINGING
INCREASED SOLAR AND REBOUNDING TEMPERATURES TO NEAR SEASONAL NORMS
ON THURSDAY. RETURN FLOW SETS UP THU NIGHT INTO FRIDAY AND WEAK
SOUTHERLY FLOW THROUGH THE DAY FRIDAY WILL RESULT IN TEMPS
CLIMBING BACK INTO THE MID 80S.
THU NIGHT INTO FRIDAY...PASSING MID LEVEL TROUGH SATURDAY WILL DRAG
ANOTHER COLD FRONT ACROSS THE REGION. TIMING OF FRONT WOULD BRING
BEST T CHANCES ACROSS EASTERN HALF OF THE FA. SUNDAY WILL BE
COOLER FOLLOWED BY MODERATING TEMPERATURES INTO EARLY NEXT WEEK
WITH DRY CONDITIONS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1146 PM CDT TUE AUG 18 2015
RAIN WILL CONTINUE FARGO-BEMIDJIJ AREAS THROUGH WEDNESDAY MORNING
(FAR) AND INTO EARLY AFTERNOON (BJI). SOME CONCERN ESP AT BJI OF
LOWER MVFR OR MAYBE IFR CIGS TOWARD SUNRISE AS DRY AIR ALOFT MOVES
IN. SEEING LOWER CIGS TO THE SOUTH MOVING INTO WADENA AND POINTS
SOUTH. OTHERWISE VFR AT THE REST OF THE TAF SITES...THOUGH WOULD
BE SUPRISED TO SEE BRIEF MVFR CIG AT FARGO NR SUNRISE. WILL
MAINTAIN DRY GFK-TVF-DVL. NORTH WINDS INCREASING TO 12 TO 25 KTS
AT MOST SITES AS SURFACE LOW MOVES NORTHEAST TOWARD DULUTH AND NW
WISCONSIN.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...SPEICHER
LONG TERM...SPEICHER/VOELKER
AVIATION...RIDDLE
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND THURSDAY
ISSUED AT 305 AM CDT WED AUG 19 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR ANALYSIS SHOW OCCLUDED
LOW PRESSURE SPINNING OVER SOUTHERN MINNESOTA AND A COLD FRONT
ARCING SOUTHWARD OVER EASTERN IOWA AND CENTRAL MISSOURI. A PRE-
FRONTAL TROUGH IN COMBINATION WITH A SHORTWAVE IS PUSHING A BROKEN
BAND OF SHOWERS NORTHEAST OVER NORTH-CENTRAL AND FAR NORTHEAST WI
EARLY THIS MORNING. THESE SHOWERS SHOULD DEPART BY 12Z. ADDITIONAL
LIGHT SHOWERS ARE OCCURRING ALONG THE COLD FRONT...WHICH WILL BE
REACHING CENTRAL WI BY 12Z. AS LOW PRESSURE AND COLD FRONT MOVE
NORTHEAST...PRECIP TRENDS ARE THE MAIN FORECAST CONCERNS.
TODAY...OCCLUDED LOW PRESSURE WILL LIFT INTO NORTHWEST WISCONSIN
EARLY THIS AFTERNOON AND INTO CENTRAL LAKE SUPERIOR BY EARLY THIS
EVENING. MEANWHILE THE COLD FRONT WILL MOVE ACROSS MOST OF THE
FORECAST AREA THIS MORNING EXCEPT FOR THE DOOR PENINSULA...WHICH
SHOULD OCCUR EARLY THIS AFTERNOON. SCATTERED SHOWERS WILL ACCOMPANY
THE COLD FRONT. BUT WITH DAYTIME HEATING...PROGGED SOUNDINGS
INDICATE THAT 500-800 J/KG OF CAPE COULD DEVELOP OVER NE WI AHEAD OF
THE FRONT. AS A RESULT...NOT OUT OF THE QUESTION THAT A FEW
THUNDERSTORMS COULD POP UP BY LATE IN THE MORNING ALONG THE
BOUNDARY. ANY THUNDERSTORMS WILL BE CAPABLE OF TRANSFERRING HIGHER
WINDS ALOFT TO THE SURFACE SO WILL KEEP A MENTION OF GUSTY WINDS
WITH ANY THUNDERSTORMS IN THE HWO. BEHIND THE FRONT...SOUTHWEST
WINDS WILL BECOME BREEZY IN THE AFTERNOON WITH SOME GUSTS TO 35 MPH
POSSIBLE. WRAP AROUND SHOWERS COULD ALSO MOVE INTO CENTRAL AND
NORTH-CENTRAL WI BY MID TO LATE AFTERNOON. HIGHS RANGING FROM THE
MID 60S WEST TO MID 70S EAST.
TONIGHT...THE UPPER TROUGH MOVES OVERHEAD AS THE SHORTWAVE IN THE
BASE OF THE TROUGH LIFTS NORTHWARD OVER EASTERN WISCONSIN. DEEPER
MOISTURE WILL ACCOMPANY THE TROUGH...WITH MOISTURE EXTENDING UPWARDS
OF 700MB OVERNIGHT. ANY BREAKS IN THE CLOUDS OVER EASTERN WISCONSIN
AT THE START OF THE NIGHT WILL THEREFORE LIKELY FILL IN AS THE
EVENING PROGRESSES AND WILL SPREAD A SLIGHT CHANCE OF RAIN ALL THE
WAY TO THE LAKESHORE. THE MORE PERSISTENT RAINS SHOULD FALL OVER
NORTH-CENTRAL WI WHERE A SURFACE TROUGH WILL MOVE THROUGH. LOWS
MAINLY IN THE 50S.
THURSDAY...THE UPPER TROUGH WILL CONTINUE TO BE OVERHEAD DURING THE
MORNING....WHICH SHOULD LEAD TO SCATTERED SHOWERS AND SPOTTY
DRIZZLE. THEN THE LIGHT PRECIP SHOULD COME TO AN END IN THE
AFTERNOON AS THE TROUGH LIFTS TO THE NORTHEAST. HIGHS RANGING FROM
THE LOW 60S NORTH TO LOW 70S SOUTH.
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY
ISSUED AT 305 AM CDT WED AUG 19 2015
THE TWO MAIN WEATEHR FEATURES TO KEY ON DURING THE EXTENDED PERIOD
WL BE THE MOVEMENT OF THE NEXT PROMINENT SHORTWAVE TROF/ASSOCIATED
CDFNT ACROSS THE NRN TIER OF STATES THIS WEEKEND INTO EARLY NEXT
WEEK AND THE BUILDING OF AN UPR RDG OVER THE HI PLAINS. THE MAIN
STICKING POINT AMONG THE MODELS IS WHETHER THIS SHORTWAVE TROF WL
BE PROGRESSIVE OR CLOSE OFF INTO AN UPR LOW SOMEWHERE NEAR THE
GREAT LAKES. THE ANSWER TO THIS QUESTION WOULD GO A LONG WAY IN
DETERMINING THE WEATEHR IN OUR AREA FROM SUNDAY THRU TUE. AFTER A
BRIEF WARM-UP THRU SAT...TEMPS ARE EXPECTED TO FALL BELOW NORMAL
FOR THE FIRST HALF OF NEXT WEEK.
THE GREAT LAKES REGION TO RESIDE ON THE NRN FRINGES OF AN AREA OF
HI PRES MOVING ALONG THE OHIO RIVER VALLEY THU NGT. CLEARING
SKIES...LIGHT WINDS AND AN INFLUX OF DRIER AIR SHOULD ALLOW TEMPS
TO FALL INTO THE MID 40S TO MID 50S RANGE WITH THE WARMER TEMPS
NEAR LAKE MI. WI TO GET ON THE BACKSIDE OF THIS RETREATING AREA OF
HI PRES ON FRI AS WINDS BACK TO THE S-SE. WAA WL GRADUALLY WORK
ACROSS THE AREA AS 8H TEMPS CLIMB TO AROUND +15C BY 00Z SAT. TEMPS
WL RESPOND WITH READINGS TOPPING OUT MAINLY IN THE MID 70S TO
AROUND 80 DEGS.
QUIET AND MILDER CONDITIONS EXPECTED FOR FRI NGT AS NE WI TO SIT
BETWEEN HI PRES TO OUR EAST AND DEVELOPING LOW PRES WELL TO OUR
WEST. BOUNDARY LAYER WINDS ARE FCST TO INCREASE THRU THE NGT AND
KEEP THE ATMOSPHERE MIXED...THEREBY PREVENTING TEMPS FROM FALLING
TOO FAR. LOOK FOR MINS TO RANGE FROM THE MID 50S TO AROUND 60 DEGS
NORTH...LWR 60S SOUTH. ATTENTION TO BE FOCUSED ON THE MOVEMENT OF
A SHARP SHORTWAVE TROF/ATTENDANT SFC CDFNT PROGGED TO REACH THE
NRN PLAINS ON SAT. THIS SYSTEM TO STILL BE TOO FAR AWAY TO IMPACT
NE WI...OTHER THAN BRING A BLUSTERY AND WARM DAY TO THE REGION.
MAX TEMPS WL RANGE FROM AROUND 80 DEGS NORTH/LAKESHORE...LWR 80S
SOUTH.
THE SHORTWAVE TROF TO PUSH EAST INTO THE UPR MS VALLEY SAT NGT...
AS THE CDFNT REACHES WRN WI BY DAYBREAK. EVEN THO INSTABILITY AND
FORCING ARE SOMEWHAT MARGINAL...THERE IS GOOD LIFT FROM THE CDFNT
AND THE 0-6KM BULK SHEAR VALUES ARE GREATER THAN 40 KTS
APPROACHING CNTRL WI LATE SAT NGT. HIGHEST POPS PLACED OVER CNTRL
WI WITH A POTENTIAL FOR PARTS OF ERN WI TO STAY DRY THRU THE NGT.
FCST CONFIDENCE IS A BIT BETTER NOW FOR SUNDAY AND BEYOND NOW THAT
THE 00Z ECMWF HAS KEPT THIS SHORTWAVE TROF PROGRESSIVE AND NOT TRY
TO CLOSE THE TROF INTO AN UPR LOW. PCPN CHCS WL CONT FOR SUNDAY AS
THE UPR TROF AND CDFNT MOVE THRU THE FCST AREA. TOKEN SMALL POPS
WERE LEFT IN THE FCST FOR MON AND TUE DUE TO THE UNCERTAINTY OF
THE MODELS HANDLING THIS SHORTWAVE TROF CORRECTLY. IF THE NEW 12Z
MODEL OUTPUTS ARE SIMILAR TO THE 00Z RUN...THEN POPS COULD BE
DROPPED FOR BOTH MON AND TUE WITH MORE SUNSHINE. ONE THING THAT IS
MORE CERTAIN WOULD BE THE DROP IN TEMPS BEHIND THE CDFNT FOR EARLY
NEXT WEEK. THIS WOULD BE ESPECIALLY TRUE ON MON WITH MAX TEMPS IN
THE UPR 60S TO THE LWR HALF OF THE 70S.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1054 PM CDT TUE AUG 18 2015
SHOWERS AND A FEW THUNDERSTORMS WILL CONTINUE TO IMPACT THE TAF
SITES DURING THE OVERNIGHT HOURS. FOR NOW THE MAIN THUNDERSTORM
ACTIVITY IS EXPECTED TO BE CONFINED TO MTW WHERE AN AREA OF
THUNDERSTORMS IS TRACKING NORTH. ONCE THE MAIN SHOWERS PASS
LINGERING LIGHT SHOWERS AND DRIZZLE WILL REMAIN WITH MVFR/IFR
CONDITIONS. THERE IS SOME POTENTIAL FOR A LINE OF SHOWERS TO
REDEVELOP WITH THE COLD FRONT ON WEDNESDAY...MAINLY FROM 13Z TO
17Z AS THE LINE OF SHOWERS WILL RACE NORTHEAST. THIS LINE OF
SHOWERS COULD POSSIBLY PRODUCE STRONG GUSTY WINDS TO AROUND 40
KNOTS. A TIGHT PRESSURE GRADIENT WILL CAUSE GUSTY SYNOPTIC WINDS
OF 25 TO 30 KNOTS DURING THE DAY ON WEDNESDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
BEACH HAZARDS STATEMENT FROM 7 AM CDT THIS MORNING THROUGH THIS
EVENING FOR WIZ022-040-050.
&&
$$
SHORT TERM.....MPC
LONG TERM......KALLAS
AVIATION.......KURIMSKI
AREA FORECAST DISCUSSION
NWS TUCSON AZ
350 AM MST WED AUG 19 2015
.SYNOPSIS...EXPECT ISOLATED THUNDERSTORMS NEAR THE INTERNATIONAL
BORDER SOUTHEAST OF TUCSON THIS AFTERNOON AND EVENING...AND ISOLATED
THUNDERSTORMS FROM TUCSON EAST AND SOUTH THURSDAY. SIGNIFICANTLY
GREATER CHANCES FOR SHOWERS AND THUNDERSTORMS WILL THEN OCCUR FRIDAY
AND CONTINUE INTO EARLY NEXT WEEK. A GRADUAL COOLING TREND WILL
PREVAIL THROUGH FRIDAY FOLLOWED BY NEAR NORMAL DAYTIME TEMPERATURES
THIS WEEKEND AND EARLY NEXT WEEK.
&&
.DISCUSSION...NWLY FLOW ALOFT CONTINUES ACROSS SE ARIZONA EARLY THIS
MORNING WITH HIGH PRESSURE CENTERED NEAR THE SOUTHERN CALIFORNIA
COAST. PRECIP-FREE CONDITIONS WILL OCCUR ACROSS MUCH OF THIS
FORECAST AREA THRU TONIGHT. HOWEVER...HAVE OPTED TO INTRODUCE A
SLIGHT CHANCE OF SHOWERS/TSTMS THIS AFTERNOON AND EVENING ACROSS SRN
PORTIONS OF COCHISE COUNTY...AND THE ERN PORTION OF SANTA CRUZ
COUNTY. SEVERAL HRRR SOLUTIONS AS WELL AS THE 19/06Z NAM12 DEPICT
THE BEST CHANCE FOR MEASURABLE RAINFALL TO OCCUR ACROSS THE HUACHUCA
MOUNTAINS. ANY SHOWERS/TSTMS SHOULD DISSIPATE AROUND SUNSET OR
SHORTLY THEREAFTER.
THE UPPER HIGH IS THEN PROGGED VIA THE 19/00Z NAM/GFS/ECMWF/CMC TO
WEAKEN ON THUR...AND THE NEAR-SURFACE FLOW REGIME IS PROGGED TO
BECOME INCREASINGLY SLY/SELY...ESPECIALLY BY THUR NIGHT. HAVE
MAINTAINED ISOLATED SHOWERS/TSMTS MAINLY FROM TUCSON EWD/SWD THUR
AFTERNOON INTO THUR NIGHT. MOISTURE WILL CONTINUE TO INCREASE ACROSS
THE AREA FRI AS HIGH PRESSURE ALOFT BECOMES POSITIONED OVER FAR WEST
TEXAS.
THUS...HAVE INCREASED POPS GENERALLY 10-20 PERCENT FRI ESPECIALLY
FROM TUCSON EAST AND SOUTH VERSUS THE INHERITED FORECAST. HOWEVER
POPS FOR FRI AFTERNOON/EVENING ARE STILL SOMEWHAT LOW RELATIVE TO
SOME GUIDANCE SUCH AS THE GFSX/ECMX. AT ANY RATE...SCATTERED
SHOWERS/TSTMS SHOULD OCCUR ACROSS MUCH OF THE AREA FRI AFTERNOON/
EVENING...WITH ISOLATED SHOWERS/TSTMS ACROSS WRN SECTIONS.
SOME DECREASE IN THE COVERAGE OF SHOWERS/TSTMS IS EXPECTED SAT GIVEN
THE PROGGED VERY LIGHT MID/UPPER LEVEL FLOW REGIME. THE POTENTIAL
THEN EXISTS FOR A FAIRLY SIGNIFICANT INCREASE IN SHOWERS/TSTMS SUN-
MON DUE TO A DEEPER SELY FLOW REGIME. THE GFS/ECMWF WERE ALSO
SIMILAR WITH DEPICTING AN INVERTED TROUGH TO ENCROACH UPON FAR SERN
SECTIONS SUN NIGHT/EARLY MON. AT ANY RATE...POPS WERE TRENDED UPWARD
BASED ON THE 19/00Z GFS/ECMWF/CMC SOLUTIONS TO REFLECT THIS NOTION.
THEREAFTER...ADEQUATE MOISTURE SUGGESTS THE CONTINUATION OF CHANCE-
CATEGORY POPS ACROSS MUCH OF SE ARIZONA MON NIGHT-TUE.
HIGH TEMPS TODAY WILL BE QUITE SIMILAR TO TEMPS ACHIEVED TUE...AND
WILL AVERAGE ABOUT 2-6 DEGS F ABOVE NORMAL. SOME MINOR DAILY COOLING
WILL THEN OCCUR THUR-FRI FOLLOWED BY NEAR NORMAL DAYTIME TEMPS FOR
MUCH OF THE AREA SAT-TUE.
&&
.AVIATION...VALID THRU 20/00Z.
SCT TO BKN CIRRUS CLOUDS UNDER NW FLOW ALOFT OTRW CLR. AFT 19/19Z
FEW-SCT 8-10KFT WITH SLGT CHC OF TSTMS OVER MTNS WELL SE OF KTUS.
LIGHT TERRAIN DRIVEN WINDS EXCEPT NW WIND 5-12 KTS IN THE SAFFORD
VALLEY THEN AFT 19/19Z WIND BECOMING W TO NW 8-15 KTS EXCEPT 15-20
KTS SAFFORD VALLEY. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
&&
.FIRE WEATHER...GENERALLY DRY CONDITIONS ARE EXPECTED WITH POSSIBLE
EXCEPTION OF AN ISOLATED THUNDERSTORM FAR SOUTHERN PART OF ZONE 152
LATE TODAY. MIN RH LEVELS TODAY WILL BE THE LOWEST OF THE WEEK AND
BOTTOM OUT IN THE 15-25 PERCENT RANGE ACROSS LOWER ELEVATIONS WITH A
DECENT AFTERNOON BREEZE AGAIN THIS AFTERNOON. THE WIND WILL BE
STRONGEST IN THE GILA VALLEY ALTHOUGH A FEW MPH LESS THAN YESTERDAY.
MOISTURE WILL BEGIN TO INCREASE THURSDAY WITH ISOLATED SHOWERS AND
THUNDERSTORMS POSSIBLE...MAINLY SOUTHERN AREAS. THEN THE MOISTURE
AND THUNDERSTORMS CHANCES WILL INCREASE AND SPREAD THROUGHOUT
SOUTHEAST ARIZONA THROUGH THE WEEKEND INTO EARLY NEXT WEEK.
&&
.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 PEACHTREE CITY GA
1113 AM EDT WED AUG 19 2015
.UPDATE...
MAIN ADJUSTMENTS IN THE NEAR TERM WERE TO LOWER POP TRENDS THROUGH
MIDDAY AND FOCUS BEST CHANCE FOR SHOWERS AND STORMS IN THE
AFTERNOON/EVENING PER THE NAM 305 THETA UPGLIDE ZONES AND THE
HRRR AS THIS HI-RES SOLUTION SEEMS TO BE THE ONLY ONE LATCHING ON
TO THE LACK OF COVERAGE OBSERVED THUS FAR. STILL VERY TROPICAL
AIRMASS WITH 1.9 INCH PWAT OFF THIS MORNING SOUNDING AND JUST
OVER 2.0 INCH FOR BMX SO CONTINUING THE FLOODING THREAT AND
STRONG TO BRIEFLY SEVERE POTENTIAL WITH AFTERNOON
DESTABILIZATION.
THE BIG PLAYER FOR THIS EVENING AND OVERNIGHT WILL BE THE
EVOLUTION OF A LARGE CONVECTIVE COMPLEX CURRENTLY UPSTREAM ACROSS
LOUISIANA. THE HRRR ALSO HAS THE MCS/MCV BRINGING AT LEAST ANOTHER
ROUND OF WIDESPREAD SHOWERS BY 02-06Z TONIGHT THOUGH SOME
UNCERTAINTY WITH INTENSITY OF CONVECTION. WILL BE MONITORING THIS
FOR AFTERNOON FCST ISSUANCE AND MAY NEED TO RAISE OVERNIGHT POPS
ACCORDINGLY. PREVIOUS DISCUSSION FOLLOWS...
BAKER
&&
.PREV DISCUSSION... /ISSUED 731 AM EDT WED AUG 19 2015/
PREV DISCUSSION... /ISSUED 430 AM EDT WED AUG 19 2015/
.SHORT TERM /TODAY THROUGH THURSDAY/...
MODELS IN GOOD AGREEMENT THROUGH THE SHORT TERM WITH A VERY GOOD
GULF CONNECTION SPREADING DEEP MOISTURE OVER THE CWA. THIS WILL
CONTINUE INTO WEDNESDAY KEEP SCATTERED TO WIDESPREAD SHOWERS AND
TSTORMS OVER THE CWA. THE BEST CHANCES WILL BE ACROSS NORTH GEORGIA
AND MAINLY DURING THE AFTERNOON AND EVENING HOURS. ALTHOUGH THUNDER
WILL BE MINIMAL EARLY THIS MORNING AND ALSO WEDNESDAY MORNING...
EXPECT THUNDER TO BECOME MORE NUMEROUS WITH DAYTIME HEATING THIS
AFTERNOON AND INTO THE EARLY EVENING HOURS. ALTHOUGH THE GREATEST
INSTABILITY WILL BE ACROSS NORTH GA...AN ISOLATED STRONG TO SEVERE
STORM WILL BE POSSIBLE JUST ABOUT ANYWHERE THIS AFTERNOON AND
EVENING WITH THE MAIN THREAT BEING STRONG WINDS. TEMPERATURES
THROUGH WEDNESDAY WILL BE PRETTY CLOSE TO PERSISTENCE DUE TO
CLOUDS AND PRECIP...AND THE MODELS HAVE A GOOD HANDLE ON THIS.
17
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
PATTERN STILL ON TRACK TO SHIFT TO WEAK W-E ZONAL FLOW ACROSS THE
SE CONUS LATE THIS WEEK THEN GO INTO WEAK NW FLOW ON THIS WEEKEND.
SOME INDICATIONS THAT A WEAK SHORTWAVE WILL AFFECT AREA ON SUNDAY BY
00Z MED RANGE MODELS. HAVE BUMPED POPS UP A LITTLE FROM BLEND. CHC
FOR FROPA NOW LOOKING LESS LIKELY EARLY NEXT WEEK SO IN THE SOUP
WE STAY. DAYTIME TEMPS SHOULD BE AT OR SLIGHTLY BELOW NORMAL SO
SOME CONSOLATION.
ATLANTIC BASIN HAS ITS FOURTH NAMED STORM...TS DANNY...AND COULD
AFFECT INTERESTS IN THE VIRGIN ISLANDS AND PERHAPS PUERTO RICO
NEXT WEEK AS DANNY MOVES SLOWLY WEST. NO OTHER FEATURES OF NOTE
THRU TUES.
SNELSON
17
&&
.AVIATION...
12Z UPDATE...
A MIX OF IFR/MVFR WILL CONTINUE THROUGH MID MORNING THEN RISE TO
VFR BY 16Z AND REMAIN VFR UNTIL EVENING. SCATTERED LIGHT SHOWERS
ACROSS THE FORECAST AREA WILL BECOME MORE NUMEROUS TODAY...THEN
DIMINISH AFTER SUNSET. WINDS WILL REMAIN SOUTHWEST LESS THAN 10
KTS.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM ON CIGS THIS MORNING
MEDIUM ON TIMING OF SHRA/TSRA
HIGH ON REMAINING ELEMENTS
17
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 84 71 89 72 / 70 50 60 30
ATLANTA 86 71 88 72 / 70 60 60 30
BLAIRSVILLE 79 70 82 65 / 70 70 60 30
CARTERSVILLE 86 72 86 69 / 70 60 60 30
COLUMBUS 87 74 88 74 / 70 60 60 30
GAINESVILLE 82 71 84 71 / 70 60 60 30
MACON 89 73 91 73 / 60 40 50 30
ROME 85 71 85 69 / 70 70 60 30
PEACHTREE CITY 87 71 90 71 / 70 60 60 30
VIDALIA 91 73 94 75 / 50 40 50 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...17/BAKER
LONG TERM....SNELSON
AVIATION...17
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
754 AM EDT WED AUG 19 2015
.SYNOPSIS...
DEEP MOISTURE WILL REMAIN ACROSS THE AREA THE AREA TODAY INTO
THURSDAY WITH SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS.
A WEAK FRONT WILL APPROACH THE AREA ON THURSDAY. THE FRONT WILL
DISSIPATE NEAR THE AREA SATURDAY...WITH HIGH PRESSURE RETURNING
FOR SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
OUR REGION WILL RESIDE ALONG THE NORTHERN PERIPHERY OF THE UPPER
RIDGE CENTERED ACROSS FLORIDA INTO THE GULF OF MEXICO. COULD SEE
WEAK SHORT WAVES CROSS THE AREA IN SOUTHWEST FLOW ALOFT. THE AIR
MASS WILL REMAIN QUITE MOIST WITH PWAT VALUES AT OR ABOVE 2 INCHES.
GIVEN POSSIBLE SHORT WAVES...WEAK TO MODERATE INSTABILITY...AMPLE
MOISTURE AND DAYTIME HEATING...WE EXPECT ANOTHER DAY OF SCATTERED
TO NUMEROUS SHOWERS AND THUNDERSTORMS. THE HRRR MODEL HAS ONE AREA
OF CONVECTION EXITING TO THE NORTHEAST EARLY THIS MORNING...THEN
NEXT ROUND MOVING INTO THE REGION FROM THE WEST EARLY THIS
AFTERNOON. HEAVY DOWNPOURS ONCE AGAIN POSSIBLE. SHOWERS AND
THUNDERSTORMS EXPECTED TO LINGER INTO TONIGHT AS A PRE-
FRONTAL TROUGH DEVELOP ACROSS THE CAROLINAS.
KEPT TEMPERATURES CLOSE TO GUIDANCE CONSENSUS WITH HIGHS IN THE
UPPER 80S TO LOWER 90S AND LOWS IN THE LOW TO MID 70S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
OUR WET PATTERN WILL HOLD THURSDAY INTO FRIDAY AS A WEAK COLD
FRONT MOVES INTO THE AREA. PRECIPITABLE WATER WILL REMAIN HIGH
WITH VALUES MAINLY AROUND 2 INCHES. HEAVY DOWNPOURS MAY OCCUR WITH
SOME OF THE THUNDERSTORMS. THE FRONT MAY SLIDE JUST SOUTH AND EAST
OF THE MIDLANDS AND CSRA FRIDAY. HAVE FOLLOWED GUIDANCE TRENDS
WITH HIGH CHANCE POPS FOR THURSDAY THEN LOW CHANCE FOR FRIDAY.
USED THE GUIDANCE CONSENSUS FOR THE HIGH TEMPERATURE FORECAST.
USED THE WARMER LOW TEMPERATURE GUIDANCE BECAUSE OF THE HIGH
MOISTURE.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
THE GFS AND ECMWF DISPLAY A DIFFUSE FRONT STALLED NEAR THE
FORECAST AREA EARLY IN THE MEDIUM-RANGE PERIOD. THE MODELS DISPLAY
ANOTHER FRONT LATE IN THE PERIOD. THE MODELS HAVE UPPER RIDGING
SATURDAY...WITH TROUGHING DURING THE REST OF THE PERIOD. THE
PATTERN SUPPORTS A CONTINUED CHANCE OF SHOWERS AND THUNDERSTORMS.
THE GFS ENSEMBLE MEAN PLUS GFS...ECMWF...AND EKD MOS SUPPORT POPS
OF MAINLY 20 TO 30 PERCENT. ABOVE NORMAL HIGH TEMPERATURES SHOULD
BE ASSOCIATED WITH THE UPPER RIDGING EARLY IN THE PERIOD. THE REST
OF THE PERIOD WILL LIKELY HAVE NEAR NORMAL TEMPERATURES.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS EXPECTED OUTSIDE OF FOG/STRATUS THIS MORNING AND
SHOWERS/THUNDERSTORMS THROUGH TONIGHT.
RESTRICTIONS IN FOG AND STRATUS HAVE DEVELOPED THIS MORNING IN THE
CSRA BUT MIXING SHOULD ALLOW A RETURN TO VFR BY 14Z. DEEP MOISTURE
AND HEATING WILL PROMOTE THE DEVELOPMENT OF SHOWERS ONCE AGAIN
THIS AFTERNOON...WHICH MAY BRING BRIEF RESTRICTIONS TO VISIBILITY
AT ALL TAF SITES. WINDS WILL BE OUT OF THE SOUTHWEST TODAY AT 5 TO
10 KNOTS.
EXTENDED AVIATION OUTLOOK...A MOIST SOUTHERLY FLOW WILL CONTINUE
THROUGH THURSDAY. THERE WILL BE SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS. STRATUS AND FOG MAY OCCUR DURING THE EARLY MORNING
HOURS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
834 AM CDT WED AUG 19 2015
.UPDATE:
ISSUED AT 829 AM CDT WED AUG 19 2015
NORTHWARD EXPANSION OF PRECIPITATION SHIELD HAS NOT MATERIALIZED
THIS MORNING AS PREVIOUSLY FORECAST. HAVE REMOVED THUNDER AS
CONVECTION IS NOW LIMITED TO ARKANSAS AND ITS THAT SOUTHWARD PUSH
ON THE LEADING EDGE THAT IS LIKELY RESPONSIBLE FOR THE DRIER
CONDITIONS ACROSS OUR AREA. STILL EXPECT THAT WE WILL SEE ISOLATED
TO SCATTERED SHOWERS DEVELOP THIS AFTERNOON AS THE SHORTWAVE MOVES
ACROSS THE AREA...BUT WIDESPREAD PRECIPITATION SHOULD BE LIMITED
TO SOUTHERN MISSOURI AND ILLINOIS.
CVKING
&&
.SHORT TERM: (THROUGH TONIGHT)
ISSUED AT 306 AM CDT WED AUG 19 2015
A STOUT COLD FRONT WAS SWEEPING THROUGH THE REGION EARLY THIS
MORNING. AT 08Z, THE FRONT STRETCHED FROM ITS PARENT CYCLONE OVER
SRN MN SEWD THROUGH ERN IA, THEN CURVED BACK SWWD THROUGH MO AND
INTO SERN KS AND NRN OK. WATER VAPOR IMAGERY AND RAP PV ANALYSES
DEPICT A SECONDARY VORT MAX DIVING INTO THE BASE OF THE TROUGH,
WHICH IS CONSISTENT WITH MODEL GUIDANCE. LARGE SCALE ASCENT AHEAD
OF THIS FEATURE WILL SUPPORT PERIODS OF SH/TS TODAY INTO TONIGHT.
PRECIPITATION SHOULD TAPER OFF TONIGHT IN THE WAKE OF THE
AFOREMENTIONED VORT MAX.
WED NIGHT/EARLY THU MORNING LOWS IN THE 50S WILL BE AROUND 10
DEGREES BELOW AVERAGE.
KANOFSKY
.LONG TERM: (THURSDAY THROUGH TUESDAY)
ISSUED AT 306 AM CDT WED AUG 19 2015
SURFACE HIGH PRESSURE BUILDS INTO THE SOUTHERN PLAINS ON THU AND
GRADUALLY SHIFTS EWD WITH TIME. THIS WILL KEEP COOLER/DRIER
CONDITIONS AND WESTERLY WINDS IN PLACE ACROSS MOST OF THE CWA ON
THU/FRI UNTIL THE SURFACE HIGH HAS SHIFTED FAR ENOUGH EAST FOR
WINDS TO TURN SLY AROUND ITS BACK SIDE. RETURN FLOW SETS UP
FARTHER WEST ACROSS THE PLAINS ON THU NIGHT/FRI AHEAD OF THE NEXT
LOW PRESSURE SYSTEM WHICH WILL BE CROSSING FROM THE PACIFIC NW
INTO THE PLAINS OVER THE WEEKEND. THIS SYSTEM WILL BRING THE NEXT
CHANCE FOR SH/TS TO THE LSX CWA OVER THE WEEKEND. ANOTHER STOUT
COLD FRONT IS EXPECTED TO MOVE ACROSS THE CWA ON SUN AND THEN
SETTLE SOUTH OF THE CWA EARLY NEXT WEEK. TEMPERATURES WILL DIP
BELOW AVERAGE AGAIN IN THE WAKE OF THIS FRONT.
KANOFSKY
&&
.AVIATION: (FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 634 AM CDT WED AUG 19 2015
RAIN SHOWERS ACROSS SOUTHWEST MISSOURI WILL SPREAD NORTHEAST
DURING THE MORNING IMPACTING KCOU AND THE ST. LOUIS AREA
TERMINALS, WITH SHOWERS BECOMING MORE SPOTTY IN THE AFTERNOON.
FUTHER NORTH WE SHOULD SEE SCATTERED SHOWERS DEVELOP IN RESPONSE
TO HEATING AND THUS THE COVERAGE AND DIRECT IMPACT AT KUIN IS LESS
CERTAIN HENCE ONLY MENTIONED VCSH. FLIGHT CONDITIONS SHOULD BE IN
THE HIGH-END MVFR TO LOW-END VFR RANGE MUCH OF THE DAY WITH
CLEARING SKIES AREAWIDE BY EARLY THIS EVENING.
SPECIFICS FOR KSTL:
RAIN SHOWERS WILL SPREAD FROM SOUTHWEST MISSOURI INTO KSTL BY
MID-MORNING. SHOWERS SHOULD PERSIST THROUGH EARLY AFTERNOON AND
THEN BECOME MORE SPOTTY BY LATE AFTERNOON. EXPECT FLIGHT
CONDITIONS IN THE HIGH-END MVFR TO LOW-END VFR RANGE MUCH OF THE
DAY WITH CLEARING SKIES EARLY THIS EVENING.
GLASS
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
648 AM CDT WED AUG 19 2015
.SHORT TERM: (THROUGH TONIGHT)
ISSUED AT 306 AM CDT WED AUG 19 2015
A STOUT COLD FRONT WAS SWEEPING THROUGH THE REGION EARLY THIS
MORNING. AT 08Z, THE FRONT STRETCHED FROM ITS PARENT CYCLONE OVER
SRN MN SEWD THROUGH ERN IA, THEN CURVED BACK SWWD THROUGH MO AND
INTO SERN KS AND NRN OK. WATER VAPOR IMAGERY AND RAP PV ANALYSES
DEPICT A SECONDARY VORT MAX DIVING INTO THE BASE OF THE TROUGH,
WHICH IS CONSISTENT WITH MODEL GUIDANCE. LARGE SCALE ASCENT AHEAD
OF THIS FEATURE WILL SUPPORT PERIODS OF SH/TS TODAY INTO TONIGHT.
PRECIPITATION SHOULD TAPER OFF TONIGHT IN THE WAKE OF THE
AFOREMENTIONED VORT MAX.
WED NIGHT/EARLY THU MORNING LOWS IN THE 50S WILL BE AROUND 10
DEGREES BELOW AVERAGE.
KANOFSKY
.LONG TERM: (THURSDAY THROUGH TUESDAY)
ISSUED AT 306 AM CDT WED AUG 19 2015
SURFACE HIGH PRESSURE BUILDS INTO THE SOUTHERN PLAINS ON THU AND
GRADUALLY SHIFTS EWD WITH TIME. THIS WILL KEEP COOLER/DRIER
CONDITIONS AND WESTERLY WINDS IN PLACE ACROSS MOST OF THE CWA ON
THU/FRI UNTIL THE SURFACE HIGH HAS SHIFTED FAR ENOUGH EAST FOR
WINDS TO TURN SLY AROUND ITS BACK SIDE. RETURN FLOW SETS UP
FARTHER WEST ACROSS THE PLAINS ON THU NIGHT/FRI AHEAD OF THE NEXT
LOW PRESSURE SYSTEM WHICH WILL BE CROSSING FROM THE PACIFIC NW
INTO THE PLAINS OVER THE WEEKEND. THIS SYSTEM WILL BRING THE NEXT
CHANCE FOR SH/TS TO THE LSX CWA OVER THE WEEKEND. ANOTHER STOUT
COLD FRONT IS EXPECTED TO MOVE ACROSS THE CWA ON SUN AND THEN
SETTLE SOUTH OF THE CWA EARLY NEXT WEEK. TEMPERATURES WILL DIP
BELOW AVERAGE AGAIN IN THE WAKE OF THIS FRONT.
KANOFSKY
&&
.AVIATION: (FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 634 AM CDT WED AUG 19 2015
RAIN SHOWERS ACROSS SOUTHWEST MISSOURI WILL SPREAD NORTHEAST
DURING THE MORNING IMPACTING KCOU AND THE ST. LOUIS AREA
TERMINALS, WITH SHOWERS BECOMING MORE SPOTTY IN THE AFTERNOON.
FUTHER NORTH WE SHOULD SEE SCATTERED SHOWERS DEVELOP IN RESPONSE
TO HEATING AND THUS THE COVERAGE AND DIRECT IMPACT AT KUIN IS LESS
CERTAIN HENCE ONLY MENTIONED VCSH. FLIGHT CONDITIONS SHOULD BE IN
THE HIGH-END MVFR TO LOW-END VFR RANGE MUCH OF THE DAY WITH
CLEARING SKIES AREAWIDE BY EARLY THIS EVENING.
SPECIFICS FOR KSTL:
RAIN SHOWERS WILL SPREAD FROM SOUTHWEST MISSOURI INTO KSTL BY
MID-MORNING. SHOWERS SHOULD PERSIST THROUGH EARLY AFTERNOON AND
THEN BECOME MORE SPOTTY BY LATE AFTERNOON. EXPECT FLIGHT
CONDITIONS IN THE HIGH-END MVFR TO LOW-END VFR RANGE MUCH OF THE
DAY WITH CLEARING SKIES EARLY THIS EVENING.
GLASS
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1042 AM EDT WED AUG 19 2015
.SYNOPSIS...
UNSETTLED WEATHER WILL CONTINUE THROUGH MID WEEK AS TROPICAL
MOISTURE STREAMS INTO THE AREA AHEAD OF AN APPROACHING COLD
FRONT. THE FRONT WILL REACH THE COASTAL CAROLINAS BY FRIDAY AND
OFFSHORE OVER THE WEEKEND. ANOTHER COLD FRONT MAY APPROACH ON
TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM WEDNESDAY...THE AREA HAS CLEAR OUT OF CONVECTION AND
CLOUDS AFTER A SHORT WAVE PROGRESSES ACROSS THE FORECAST AREA THIS
MORNING. THE HRRR IS SHOWING VERY WEAK FORCING THE REMAINDER IN
THE SOUTHWEST FLOW ALOFT. INSTABILITIES ARE MODERATE FOR THIS
AFTERNOON AND THE PRIMARY THREAT APPEARS TO BE LOCALLY HEAVY
DOWNPOURS.
THE 13 UTC RUN OF THE HRRR IS SHOWING DIURNAL CONVECTION
DEVELOPING ALONG THE SEA BREEZE FIRST JUST AFTER 16 UTC AND THEN
BECOMING SCATTERED INLAND AND SLOWLY DISSIPATING AFTER SUNSET.
TEMPERATURES ARE RUNNING A LITTLE WARMER AS LACK OF CLOUD COVER IS
ALLOWING THE TEMPERATURES TO INCREASE QUICKER BUT EXPECTED THE
CLOUD COVER TO INCREASE QUICKLY THIS AFTERNOON WHEN THE CONVECTIVE
TEMPERATURE IS MET.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...BIGGEST QUESTION MARK FOR THE SHORT TERM
WILL BE HOW FAR SOUTH DOES A COLD FRONT PROGRESS ACROSS THE
CAROLINAS.
AHEAD OF THIS FEATURE...SHARP RIDGING ALOFT COMBINED WITH
RETURN FLOW WILL PUMP HEAT AND HUMIDITY INTO THE REGION...AND HIGHS
WILL RISE INTO THE 90S EVERYWHERE AWAY FROM THE IMMEDIATE COAST.
THIS IS SEVERAL DEGREES ABOVE NORMAL FOR MID-AUGUST...AND THE HIGH
DEWPOINTS WILL MAKE HEAT INDEX VALUES RISE TO 100 OR SLIGHTLY
GREATER. AMPLE INSTABILITY WITHIN THIS AIRMASS WILL BE TAPPED BY A
SHORTWAVE PROGGED TO MOVE OVERHEAD IN THE AFTN...AND SCATTERED TO
POTENTIALLY WIDESPREAD CONVECTION IS POSSIBLE. MOS P-NUMBERS HAVE
INCREASED TO LIKELY ACROSS THE AREA...BUT THEY HAVE BEEN OVERDONE
RECENTLY. WILL BUMP POP TO HIGH-CHC LOCALLY WITH PERIODS OF HEAVY
RAINFALL THE BIGGEST THREAT. LOWS THURSDAY NIGHT WILL BE QUITE
WARM...FALLING INTO THE MID 70S...WITH SOME UPPER 70S POSSIBLE ALONG
THE COAST.
FRIDAY WILL BE THE TRANSITION DAY AS THE COLD FRONT TO THE WEST
MOVES ACROSS THE AREA. ALL GUIDANCE HAS INCREASED THE SPEED OF THIS
FEATURE...LIKELY DUE TO A STRONGER PARENT TROUGH AND VORT LOBE..WITH
LESS MID-LEVEL PARALLEL FLOW. WPC SUPPORTS THIS FASTER GUIDANCE AS
WELL...SO WILL SHOW THE FRONT MOVING OFFSHORE BY LATE FRIDAY.
CONVECTION WILL ACCOMPANY THIS BOUNDARY AS IT SWINGS S/SE FRIDAY
INTO FRIDAY NIGHT...BUT DRYING DOES OCCUR IN EARNEST LATE SO BEST
PRECIP CHANCES WILL BE THE FIRST HALF OF FRIDAY. TEMPS WILL REMAIN
ABOVE NORMAL THANKS TO WARM ADVECTION AHEAD OF THE BOUNDARY...BUT
WILL BE A FEW DEGREES COOLER THAN THURSDAY. LOWS FRIDAY NIGHT WILL
REMAIN ABOVE CLIMO AS WEAK COLD ADVECTION LAGS...WITH MINS DROPPING
INTO THE 72-75 DEGREE RANGE...WARMEST AT THE COAST.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 300 AM WEDNESDAY...COLD FRONT PUSHING OFFSHORE FIRST THING
SATURDAY WILL LEAVE CLEARING SKY CONDITIONS AND IMPROVING WEATHER
FOR THE WKND. WHILE THIS FASTER FROPA REPRESENTS A CHANGE IN THE
FORECAST...GUIDANCE IS IN GOOD AGREEMENT ATTM WITH A STRONG MID-
LEVEL PUSH...AND THE WKND IS LOOKING TO BE QUITE NICE LOCALLY NOW.
WEAK COOL ADVECTION BUT STRONG DRY ADVECTION WILL ERODE CLOUDS
SATURDAY...AND THEN LEAVE AMPLE SUNSHINE LATE SATURDAY AND ON
SUNDAY...AS PWATS DROP TO AROUND THE FIRST QUARTILE MOVING-AVERAGE
FOR LATE AUGUST. TEMPS THIS WKND WILL BE AROUND OR SLIGHTLY BELOW
CLIMO WITH N/NE WINDS...BUT OVERALL A PLEASANT WKND APPEARS TO BE IN
STORE. RETURN FLOW BEGINS TO REDEVELOP MONDAY WITH TEMPS WARMING
BACK TO SEASONABLE LEVELS OR SLIGHTLY ABOVE...BUT THIS WILL BE
ACCOMPANIED BY INCREASING PRECIP CHANCES AS WELL. GFS DRIVES A
POTENT SHORTWAVE OVERHEAD LATE MONDAY INTO TUESDAY...A PIECE OF THE
LONGER TROUGH TRAVERSING THE NORTHEAST...WHILE THE ECMWF SHOWS NO
SUCH FEATURE. FOR NOW WILL RAMP POP BACK UP TO CLIMO VALUES FOR
EARLY NEXT WEEK...MAINTAINING THE INHERITED FORECAST
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
AS OF 12Z...AREAS OF MVFR DUE TO FOG THIS MORNING...GIVING WAY TO
VFR FOR THE REST OF THE VALID TAF PERIOD WITH ISOLATED TO SCATTERED
SHRA/TSRA POSSIBLE.
LATEST RADAR IMAGERY DEPICTS A FEW LIGHT SHOWERS ACROSS THE AREA
THIS MORNING...WITH OBSERVATIONS INDICATING LIGHT WINDS AND PATCHY
AREAS OF FOG. COULD SEE BRIEF MARGINAL MVFR DUE TO FOG THIS
MORNING...BUT CONFIDENCE IS LOW. EXPECT VFR TO PREVAIL LATER THIS
MORNING WITH ISOLATED TO SCATTERED SHRA/TSRA ACTIVITY THROUGH TODAY
AND SOUTHWEST WINDS INCREASING TO AOB 12 KTS. INTO THE EVENING
HOURS...CONVECTION WILL TAPER OFF AND WINDS WILL BECOME
LIGHT.
EXTENDED OUTLOOK...SCATTERED CONVECTION IS EXPECTED THROUGH THE
PERIOD...MOST ACTIVE WEDNESDAY AND THURSDAY WITH BRIEF IFR
CONDITIONS POSSIBLE.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM WEDNESDAY...LIGHT SOUTHWEST WINDS OVER THE WATERS
THIS MORNING WITH SEAS RUNNING 2 TO 3 FEET WITH A 1.3 EAST
SOUTHEAST SWELL. SCATTERED THUNDERSTORMS ARE POSSIBLE THIS
AFTERNOON AS A FEW STORMS THAT DEVELOP ALONG THE COAST COULD MOVE
OUT OVER THE WATER. THE MAIN THREAT APPEARS TO BE LIGHTNING.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...PRE- FRONTAL REGIME THURSDAY WILL LEAVE
SW WINDS OF 10-15 KTS ACROSS THE WATERS. THIS WILL BE SHORT-LIVED
HOWEVER AS A COLD FRONT RACES TOWARDS THE WATERS DURING FRIDAY.
THIS FRONT WILL CROSS INTO THE WATERS AND THEN DROP SOUTH BY
FRIDAY NIGHT...LEAVING WINDS SHIFTING FROM WEST...ALL THE WAY
AROUND TO THE EAST...AND THEN FINALLY TAKING ON A PREDOMINANT NE
DIRECTION LATE IN THE PERIOD. SPEEDS THROUGH FRIDAY WILL BE LIGHT
REGARDLESS OF DIRECTION...LESS THAN 10 KTS. SEAS THURSDAY WILL BE
2-3 FT WITH A SE SWELL AND SW WIND CHOP COMPRISING THE SPECTRUM.
WAVE HEIGHTS FRIDAY WILL DROP TO JUST 1-2 FT ON THE LIGHTER
WINDS...WITH A VARIETY OF WAVE GROUPS PRESENT.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 AM WEDNESDAY...COLD FRONT WILL BE SOUTH OF THE WATERS
SATURDAY MORNING...LEAVING NE WINDS IN ITS WAKE. THIS WIND DIRECTION
WILL PERSIST MUCH OF THE PERIOD...BUT A WEAKENING OF THE FRONT WILL
ALLOW RETURN FLOW AND SOUTHERLY WINDS TO REDEVELOP LATE. SPEEDS FROM
THE NE WILL BE 10-15 KTS...EASING AS THE WINDS SHIFT AT THE END OF
THE PERIOD. WAVE HEIGHTS WILL BE PRIMARILY WIND-WAVE DRIVEN...BUT OF
LOW AMPLITUDE AROUND 1-3 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HAWKINS
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1111 AM EDT WED AUG 19 2015
.SYNOPSIS...
WARM AND HUMID AIR TODAY WILL ALLOW FOR SHOWERS AND THUNDERSTORMS
TO DEVELOP...IN ADVANCE OF A COLD FRONT THAT WILL MOVE THROUGH THE
AREA THURSDAY MORNING. MUCH DRIER CONDITIONS ARE EXPECTED ON
THURSDAY AND FRIDAY...WITH SLIGHTLY COOLER TEMPERATURES AND LESS
HUMIDITY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A PLUME OF HIGHER PWATS...AROUND 2"...WILL CONTINUE TO ADVECT
NORTHEAST INTO THE REGION THIS AFTERNOON. CURRENT RADAR MOSAIC
CONTINUES TO SHOW AN EMBEDDED DISTURBANCE NEAR THE TRI-STATE
REGION WITH SHOWERS...AND A FEW LIGHTNING STRIKES. THIS FEATURE
WILL MOVE EAST/NORTHEAST INTO THE AFTERNOON. WITH DESTABILIZATION
AHEAD OF IT...SCATTERED TO LIKELY CONVECTION SHOULD FILL IN ACRS
OUR EASTERN AREAS. FOR LATER THIS AFTERNOON INTO THIS
EVENING...HIGH RESOLUTION MODELS STILL ARE ADVERTISING A
POTENTIAL PREFRONTAL TROF TO MOVE INTO THE AREA. THIS WILL BECOME
THE FOCUS FOR MORE SHOWERS AND EMBEDDED THUNDERSTORMS. OVERALL
BULK SHEAR WILL BE WEAK...SO ORGANIZATION TO THE CONVECTION WILL
BE LACKING. IN ADDITION...MLCAPES MAY ONLY RANGE FROM 800-1200
J/KG AT PEAK HEATING WITH THE HIGHEST IN THE EAST. ALSO...WITH HIGH
PWATS...DCAPES WILL BE LOW (LACK OF MID LEVEL DRY AIR). ALL IN ALL...
ONLY A MARGINAL RISK FOR SEVERE TODAY WITH PERHAPS GUSTY WINDS
DUE TO PCPN LOADING. FREEZING LEVELS WILL REMAIN HIGH TO KEEP HAIL
SIZE IN CHECK. IF ANYTHING...LOCALLY HEAVY RAINFALL MAY END UP
BEING THE MAIN CONCERN GIVEN HIGH PWATS. HIGHS TODAY WILL BE PCPN
AND CLOUD DEPENDENT WITH THE HIGHER VALUES FAVORING OUR EAST AS
SOME INSOLATION OCCURS BEFORE CLOUDING OVER. WILL CONTINUE WITH
LOWER TO MID 80S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
THIS EVENING THE UPPER LEVEL LOW OVER MINNESOTA WILL START TO PULL
NORTH AS ANOTHER LOW DIVES SOUTH NEAR THE HUDSON BAY. AT THE SAME
TIME A COLD FRONT WILL BE APPROACHING FROM THE WEST. EXPECTING
COVERAGE TO AGAIN INCREASE THIS EVENING AS MODELS ARE HINTING AT
SOME LOW LEVEL CONVERGENCE FROM A LLJ MOVING IN FROM THE
SOUTHWEST. THE MAIN QUESTION WILL BE WHERE AND IF THE JET SETS
UP. ALSO AT 250 MB A SPLITTING JET STRUCTURE CAN BE FOUND AROUND
KENTUCKY/ TENNESSEE JUST SOUTH OF THE AREA. IN NORTHERN OHIO THE
UPPER LEVEL FLOW REMAINS MORE UNIFORM SPATIALLY (MUCH LESS UPPER
LEVEL DIFFLUENCE). DUE TO THE MENTIONED ABOVE HIGH RES MODELS SHOW
MORE COVERAGE IN CONVECTION THROUGH OUR CWA AND SOUTH OF OUR CWA
WHILE A BREAK COULD POSSIBLY EXIST IN NORTHERN OHIO AND MICHIGAN.
PWATS ARE STILL EXPECTED TO BE AROUND 1.90" AHEAD OF THE FRONT
THOUGH AND WITH UPPER LEVEL SUPPORT DECIDED TO LEAVE POP
DISTRIBUTION AS IS. REGARDING SEVERE POTENTIAL... INSTABILITY WILL
WANE AFTER THE SUNSETS WHILE BY FAR THE BEST SPEED SHEAR LIES JUST
BEHIND THE FRONT. LAPSE RATES ALSO DON`T APPEAR PARTICULARLY
FAVORABLE... THUS THE MARGINAL RISK BY SPC SEEMS SUFFICIENT.
TIMING OF THE FRONTAL PASSAGE HAS ALSO BEEN SLOWING THE LAST
COUPLE OF DAYS. THE EURO AND NAM ARE NOW MORE IN AGREEMENT WITH A
SLOWER FRONTAL PASSAGE. THEY HAVE THE FRONT PASSING THROUGH
CINCINNATI AROUND 12Z (8 AM) WHILE CLEARING THE CWA 6 HRS LATER.
BEHIND THE FRONT MUCH LOWER PWAT AIR AND FALLING DEWPOINTS WILL
BE USHERED IN. 850 TEMPS ALSO FALL FROM AROUND 16/ 15 DEGREES C TO
NEAR 11 DEGREES C BY THURSDAY EVENING. THIS WILL KEEP HIGH TEMPS
IN THE MID TO UPPER 70S ACROSS THE REGION THURSDAY.
FRIDAY MORNING HIGH PRESSURE WILL MOVE OVERHEAD ALLOWING FOR
TEMPERATURES TO QUICKLY FALL AND BOTTOM OUT IN THE MID 50S. THE
NAM HAS CONTINUED TO SHOW SOME CIRRUS POSSIBLE ACROSS OUR
SOUTHEASTERN ZONES IN ASSOCIATION WITH A WEAK DISTURBANCE WHILE
THE GFS AND EURO SHOW THE CIRRUS FURTHER EAST. FOR NOW HAVE KEPT
CIRRUS OUT OF THE AREA FRIDAY MORNING ALLOWING FOR MAX RADIATIONAL
COOLING. FRIDAY AFTERNOON WILL BE BEAUTIFUL WITH HIGHS LIKELY
RIGHT AROUND OR JUST BELOW 80 DEGREES AS 850 MB TEMPS REMAIN
AROUND 10 OR 11 DEGREES C. DEWPOINTS WILL ALSO LIKELY MIX OUT
ALLOWING FOR RELATIVE HUMIDITY PERCENTAGES IN THE UPPER 30S.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
THE NEXT SYSTEM WILL APPROACH AND MOVE THROUGH THE REGION SUNDAY
INTO SUNDAY NIGHT. MODELS ARE IN DECENT AGREEMENT WITH THIS SYSTEM
AND THEREFORE WENT WITH LIKELY PRECIPITATION CHANCES. HIGH
PRESSURE AND DRY CONDITIONS WILL RETURN TO THE REGION MONDAY
THROUGH TUESDAY.
HIGH TEMPERATURES ARE GENERALLY EXPECTED TO BE SLIGHTLY BELOW NORMAL
EXCEPT ON SUNDAY WHEN HIGH TEMPERATURES ARE EXPECTED TO BE SLIGHTLY
ABOVE NORMAL.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
A THUNDERSTORM COMPLEX IS MOVING EAST ACROSS SOUTHERN ILLINOIS AND
INTO SOUTHWEST INDIANA ATTM AND WE ARE BEGINNING TO SEE SOME
SCATTERED DEVELOPMENT OUT AHEAD OF IT ACROSS WESTERN KENTUCKY AND
SOUTH CENTRAL INDIANA. THE LATEST HRRR SEEMS TO HAVE A DECENT
HANDLE ON THIS...BUT IS PERHAPS A COUPLE OF HOURS SLOW WITH ITS
POSITIONING. THIS NEW DEVELOPMENT IS IN AN AREA OF BETTER
INSTABILITIES ALONG THE OHIO RIVER SO THINK THIS MAY BECOME THE MORE
DOMINANT PCPN FEATURE OVER THE NEXT HOUR OR TWO. KCVG AND KLUK
SHOULD HAVE THE BEST CHANCE OF BEING AFFECTED BY THIS IN THE NEAR
TERM AS IT CONTINUES TO WORK ITS WAY EASTWARD THROUGH MID MORNING.
THE CONVECTIVE ALLOWING MODELS ARE GENERALLY TRYING TO SHOW AT
LEAST SOME ADDITIONAL SCATTERED DEVELOPMENT ELSEWHERE ACROSS THE
AREA IN ASSOCIATION WITH A PRE FRONTAL TROUGH LATER THIS MORNING
AND INTO EARLY TO MID AFTERNOON. TIMING IS SOMEWHAT DIFFICULT
THOUGH SO WILL GENERALLY HAVE A VCTS THROUGH MUCH OF THE DAY AND
THEN TRY TO INCLUDE SOME TEMPO GROUPS FOR THE MORE FAVORABLE TIME
PERIODS.
WE MAY THEN GET INTO A BIT OF A LULL LATER THIS AFTERNOON INTO
EARLY EVENING BEFORE BETTER FORCING ASSOCIATED WITH THE ACTUAL
FRONT BEGINS TO WORK IN FROM THE WEST. THERE ARE STILL SOME TIMING
DIFFERENCES BETWEEN THE MODELS WITH THE FRONT FOR TONIGHT...BUT
OVERALL EXPECT TO TRANSITION TO MORE WIDESPREAD SHOWERS AND
EMBEDDED THUNDERSTORMS HEADING INTO TONIGHT. PREVAILING CIGS WILL
DROP DOWN INTO MVFR AND THEN PROBABLY IFR AS THE FRONT
APPROACHES/MOVES THROUGH OVERNIGHT.
OUTLOOK...THUNDERSTORMS POSSIBLE SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HAINES
NEAR TERM...HICKMAN
SHORT TERM...HAINES
LONG TERM...NOVAK
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
624 AM EDT WED AUG 19 2015
.SYNOPSIS...
WARM AND HUMID AIR TODAY WILL ALLOW FOR SHOWERS AND THUNDERSTORMS
TO DEVELOP...IN ADVANCE OF A COLD FRONT THAT WILL MOVE THROUGH THE
AREA THURSDAY MORNING. MUCH DRIER CONDITIONS ARE EXPECTED ON
THURSDAY AND FRIDAY...WITH SLIGHTLY COOLER TEMPERATURES AND LESS
HUMIDITY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EARLIER LINE OF SHOWERS AND THUNDERSTORMS OUT IN INDIANA HAS ALL
BUT FIZZLED THIS MORNING WITH MORE CONVECTION CURRENTLY FIRING IN
SOUTHERN ILLINOIS. HIGH RES MODELS ARE SHOWING THIS CONVECTION
CONTINUING TO WEAKEN AS IT PROGRESSES EASTWARDS BUT MAKING IT TO
CINCINNATI LATE MORNING. FORECAST SOUNDINGS FOR THIS AFTERNOON
SHOW MOISTURE LEVELS QUICKLY RISING TO NEAR 1.90" WITH K INDEX
VALUES PEAKING IN THE UPPER 30S. SHEAR VALUES REMAIN WEAK THIS
AFTERNOON WITH SFC TO 6 KM VALUES ONLY AROUND 10 KTS. CAPE VALUES
ON BOTH THE GFS AND NAM ARE AROUND 1500 J/KG ON AVERAGE FOR THIS
AFTERNOON. IN THE MID LEVELS POCKETS OF PVA ARE FORECASTED TO MOVE
ACROSS THE REGION THIS AFTERNOON WHICH WILL SUPPORT POCKETS OF
LIFT. HIGH RES MODELS ARE MIXED ON THE AMOUNT OF COVERAGE. THERE
DOES APPEAR TO BE A WEAK BOUNDARY THAT SETS UP THIS AFTERNOON SOME
WHERE ACROSS THE CWA THOUGH. GIVEN THE ABUNDANT MOISTURE...
SUFFICIENT INSTABILITY AND LIFT HAVE PUSHED POPS TO LIKELY THIS
AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
THIS EVENING THE UPPER LEVEL LOW OVER MINNESOTA WILL START TO PULL
NORTH AS ANOTHER LOW DIVES SOUTH NEAR THE HUDSON BAY. AT THE SAME
TIME A COLD FRONT WILL BE APPROACHING FROM THE WEST. EXPECTING
COVERAGE TO AGAIN INCREASE THIS EVENING AS MODELS ARE HINTING AT
SOME LOW LEVEL CONVERGENCE FROM A LLJ MOVING IN FROM THE
SOUTHWEST. THE MAIN QUESTION WILL BE WHERE AND IF THE JET SETS
UP. ALSO AT 250 MB A SPLITTING JET STRUCTURE CAN BE FOUND AROUND
KENTUCKY/ TENNESSEE JUST SOUTH OF THE AREA. IN NORTHERN OHIO THE
UPPER LEVEL FLOW REMAINS MORE UNIFORM SPATIALLY (MUCH LESS UPPER
LEVEL DIFFLUENCE). DUE TO THE MENTIONED ABOVE HIGH RES MODELS SHOW
MORE COVERAGE IN CONVECTION THROUGH OUR CWA AND SOUTH OF OUR CWA
WHILE A BREAK COULD POSSIBLY EXIST IN NORTHERN OHIO AND MICHIGAN.
PWATS ARE STILL EXPECTED TO BE AROUND 1.90" AHEAD OF THE FRONT
THOUGH AND WITH UPPER LEVEL SUPPORT DECIDED TO LEAVE POP
DISTRIBUTION AS IS. REGARDING SEVERE POTENTIAL... INSTABILITY WILL
WANE AFTER THE SUNSETS WHILE BY FAR THE BEST SPEED SHEAR LIES JUST
BEHIND THE FRONT. LAPSE RATES ALSO DON`T APPEAR PARTICULARLY
FAVORABLE... THUS THE MARGINAL RISK BY SPC SEEMS SUFFICIENT.
TIMING OF THE FRONTAL PASSAGE HAS ALSO BEEN SLOWING THE LAST
COUPLE OF DAYS. THE EURO AND NAM ARE NOW MORE IN AGREEMENT WITH A
SLOWER FRONTAL PASSAGE. THEY HAVE THE FRONT PASSING THROUGH
CINCINNATI AROUND 12Z (8 AM) WHILE CLEARING THE CWA 6 HRS LATER.
BEHIND THE FRONT MUCH LOWER PWAT AIR AND FALLING DEWPOINTS WILL
BE USHERED IN. 850 TEMPS ALSO FALL FROM AROUND 16/ 15 DEGREES C TO
NEAR 11 DEGREES C BY THURSDAY EVENING. THIS WILL KEEP HIGH TEMPS
IN THE MID TO UPPER 70S ACROSS THE REGION THURSDAY.
FRIDAY MORNING HIGH PRESSURE WILL MOVE OVERHEAD ALLOWING FOR
TEMPERATURES TO QUICKLY FALL AND BOTTOM OUT IN THE MID 50S. THE
NAM HAS CONTINUED TO SHOW SOME CIRRUS POSSIBLE ACROSS OUR
SOUTHEASTERN ZONES IN ASSOCIATION WITH A WEAK DISTURBANCE WHILE
THE GFS AND EURO SHOW THE CIRRUS FURTHER EAST. FOR NOW HAVE KEPT
CIRRUS OUT OF THE AREA FRIDAY MORNING ALLOWING FOR MAX RADIATIONAL
COOLING. FRIDAY AFTERNOON WILL BE BEAUTIFUL WITH HIGHS LIKELY
RIGHT AROUND OR JUST BELOW 80 DEGREES AS 850 MB TEMPS REMAIN
AROUND 10 OR 11 DEGREES C. DEWPOINTS WILL ALSO LIKELY MIX OUT
ALLOWING FOR RELATIVE HUMIDITY PERCENTAGES IN THE UPPER 30S.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
THE NEXT SYSTEM WILL APPROACH AND MOVE THROUGH THE REGION SUNDAY
INTO SUNDAY NIGHT. MODELS ARE IN DECENT AGREEMENT WITH THIS SYSTEM
AND THEREFORE WENT WITH LIKELY PRECIPITATION CHANCES. HIGH
PRESSURE AND DRY CONDITIONS WILL RETURN TO THE REGION MONDAY
THROUGH TUESDAY.
HIGH TEMPERATURES ARE GENERALLY EXPECTED TO BE SLIGHTLY BELOW NORMAL
EXCEPT ON SUNDAY WHEN HIGH TEMPERATURES ARE EXPECTED TO BE SLIGHTLY
ABOVE NORMAL.
&&
.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
A THUNDERSTORM COMPLEX IS MOVING EAST ACROSS SOUTHERN ILLINOIS AND
INTO SOUTHWEST INDIANA ATTM AND WE ARE BEGINNING TO SEE SOME
SCATTERED DEVELOPMENT OUT AHEAD OF IT ACROSS WESTERN KENTUCKY AND
SOUTH CENTRAL INDIANA. THE LATEST HRRR SEEMS TO HAVE A DECENT
HANDLE ON THIS...BUT IS PERHAPS A COUPLE OF HOURS SLOW WITH ITS
POSITIONING. THIS NEW DEVELOPMENT IS IN AN AREA OF BETTER
INSTABILITIES ALONG THE OHIO RIVER SO THINK THIS MAY BECOME THE MORE
DOMINANT PCPN FEATURE OVER THE NEXT HOUR OR TWO. KCVG AND KLUK
SHOULD HAVE THE BEST CHANCE OF BEING AFFECTED BY THIS IN THE NEAR
TERM AS IT CONTINUES TO WORK ITS WAY EASTWARD THROUGH MID MORNING.
THE CONVECTIVE ALLOWING MODELS ARE GENERALLY TRYING TO SHOW AT
LEAST SOME ADDITIONAL SCATTERED DEVELOPMENT ELSEWHERE ACROSS THE
AREA IN ASSOCIATION WITH A PRE FRONTAL TROUGH LATER THIS MORNING
AND INTO EARLY TO MID AFTERNOON. TIMING IS SOMEWHAT DIFFICULT
THOUGH SO WILL GENERALLY HAVE A VCTS THROUGH MUCH OF THE DAY AND
THEN TRY TO INCLUDE SOME TEMPO GROUPS FOR THE MORE FAVORABLE TIME
PERIODS.
WE MAY THEN GET INTO A BIT OF A LULL LATER THIS AFTERNOON INTO
EARLY EVENING BEFORE BETTER FORCING ASSOCIATED WITH THE ACTUAL
FRONT BEGINS TO WORK IN FROM THE WEST. THERE ARE STILL SOME TIMING
DIFFERENCES BETWEEN THE MODELS WITH THE FRONT FOR TONIGHT...BUT
OVERALL EXPECT TO TRANSITION TO MORE WIDESPREAD SHOWERS AND
EMBEDDED THUNDERSTORMS HEADING INTO TONIGHT. PREVAILING CIGS WILL
DROP DOWN INTO MVFR AND THEN PROBABLY IFR AS THE FRONT
APPROACHES/MOVES THROUGH OVERNIGHT.
OUTLOOK...THUNDERSTORMS POSSIBLE SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HAINES
NEAR TERM...HAINES
SHORT TERM...HAINES
LONG TERM...NOVAK
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS NORMAN OK
1026 AM CDT WED AUG 19 2015
.UPDATE...
ADJUSTED PRECIP/WX THROUGH THE AFTERNOON... MINOR ADJUSTMENTS TO
TEMPS...
&&
.DISCUSSION...
SHOWERS AND THUNDERSTORMS CONTINUE TO DECREASE IN COVERAGE ACROSS
S/SWRN OK AND WRN N TX THIS MORNING. THIS TREND LOOKS TO CONTINUE
THROUGH THE AFTN AS THE H700 SHORT WAVE PUSHES EAST... DECREASING
MID-LEVEL SUPPORT. BUFR SOUNDINGS SUGGEST DECREASING SHEAR AND
INSTABILITY ENVIRONMENT WILL CONTINUE TO EVOLVE ACROSS SRN OK/WRN
N TX THROUGH THE EARLY AFTN. HRRR HAS SHOWN RELATIVELY DECENT
CONTINUITY THIS AM... WITH SHOWERS AND ISOLATED THUNDER LINGERING
THROUGH THE AFTN AND INTO THE EVENING ACROSS SOUTH CENTRAL OK.
ADJUSTED HIGH TEMPS SLIGHTLY FOR THIS AFTN... BRINGING OKC TO 67.
THROUGH 10AM... ALREADY REACHED 65... AND BEGINNING TO SEE SOME
BREAKS IN THE CLOUDS ACROSS NWRN OK. IF A FEW BREAKS DEVELOP OVER
CENTRAL OK THIS AFTN... TEMPS COULD EASILY MOVE INTO THE UPPER
60S FOR HIGHS... SO ENJOY.
JTK
&&
.PREV DISCUSSION... /ISSUED 628 AM CDT WED AUG 19 2015/
DISCUSSION...
THE 12Z AVIATION DISCUSSION FOLLOWS....
AVIATION...
WIDESPREAD RA AND TSRA WILL CONTINUE ALONG...AND IN THE GENERAL
VICINITY OF...A STRONG COLD FRONT ACROSS OK AND N TX. SCT SHRA
WILL ALSO OCCUR WELL INTO THE COOLER AIR OVER N OK UNTIL HIGH
PRESSURE FILLS IN THIS AFTERNOON/EVENING. SCATTERED AREAS OF LOW
CLOUDS AND TEMPORARY LOW VISIBILITIES WILL OCCUR NEAR THE NUMEROUS
TSRA. AS HIGH PRESSURE CONTINUES TO BUILD INTO OK/N TX THIS
EVENING AND OVERNIGHT...THE RAIN WILL BECOME LIMITED TO THE FAR
S...AND SKIES WILL BEGIN TO CLEAR IN THE N. BY SUNRISE...EXPECT
VFR CONDITIONS AND LIGHT WINDS. AREAS THAT CLEAR BEFORE SUNRISE
MAY DEVELOP GROUND FOG.
CMS
PREV DISCUSSION... /ISSUED 409 AM CDT WED AUG 19 2015/
DISCUSSION...
AN UNSEASONABLY STRONG COLD FRONT EXTENDED FROM EAST-CENTRAL TO
SOUTHWEST OKLAHOMA EARLY THIS MORNING...WITH AN OUTFLOW BOUNDARY
EXTENDING FARTHER TO THE SOUTH...ROUGHLY FROM SHAWNEE TO WICHITA
FALLS. MUCH COOLER AND DRIER AIR WAS OVER KANSAS...AND WILL SHIFT
SOUTH TODAY AND TONIGHT.
THE COMBINED EFFECTS OF THE COOLER/DRIER AIR...AND RAIN FALLING
THROUGH IT...WILL RESULT IN TEMPERATURES THAT ARE VERY COOL FOR
THIS TIME OF YEAR. RECORD LOW MAXIMUM TEMPERATURES ARE LIKELY
ACROSS MUCH OF THE REGION TODAY...AND RECORD LOW MINIMUM
TEMPERATURES ARE LIKELY TOMORROW MORNING. THE BALANCE OF THE
VARIOUS ELEMENTS AFFECTING TEMPERATURE TODAY IS A MAJOR
CHALLENGE...AND TEMPERATURE FORECASTS TODAY SHOULD BE CONSIDERED
AS APPROXIMATE...ESPECIALLY HOURLY TEMPERATURES.
RAIN CHANCES ARE ALSO PROBLEMATIC TODAY...AS THE EVOLUTION OF THE
CURRENT MCS IS UNCLEAR. HAVE GENERALLY FORECAST POPS ABOVE THE
OVERALL MODEL GUIDANCE VALUES...ON THE ASSUMPTION THAT THE MCS
WILL HOLD TOGETHER AT LEAST THROUGH MID-MORNING.
AFTER A DAY OF COOL DRY WEATHER...THE WARM/HUMID AIR WILL RETURN
NORTH...BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS
FRIDAY. A SERIES OF DISTURBANCES WILL KEEP RAIN IN THE FORECAST
UNTIL EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 69 54 81 61 / 100 10 0 10
HOBART OK 70 54 84 63 / 80 10 0 20
WICHITA FALLS TX 74 57 85 66 / 100 20 0 20
GAGE OK 75 53 82 62 / 30 10 0 10
PONCA CITY OK 73 53 82 61 / 60 10 0 10
DURANT OK 82 59 82 65 / 80 50 10 20
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
608 AM CDT WED AUG 19 2015
UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND THURSDAY
ISSUED AT 305 AM CDT WED AUG 19 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR ANALYSIS SHOW OCCLUDED
LOW PRESSURE SPINNING OVER SOUTHERN MINNESOTA AND A COLD FRONT
ARCING SOUTHWARD OVER EASTERN IOWA AND CENTRAL MISSOURI. A PRE-
FRONTAL TROUGH IN COMBINATION WITH A SHORTWAVE IS PUSHING A BROKEN
BAND OF SHOWERS NORTHEAST OVER NORTH-CENTRAL AND FAR NORTHEAST WI
EARLY THIS MORNING. THESE SHOWERS SHOULD DEPART BY 12Z. ADDITIONAL
LIGHT SHOWERS ARE OCCURRING ALONG THE COLD FRONT...WHICH WILL BE
REACHING CENTRAL WI BY 12Z. AS LOW PRESSURE AND COLD FRONT MOVE
NORTHEAST...PRECIP TRENDS ARE THE MAIN FORECAST CONCERNS.
TODAY...OCCLUDED LOW PRESSURE WILL LIFT INTO NORTHWEST WISCONSIN
EARLY THIS AFTERNOON AND INTO CENTRAL LAKE SUPERIOR BY EARLY THIS
EVENING. MEANWHILE THE COLD FRONT WILL MOVE ACROSS MOST OF THE
FORECAST AREA THIS MORNING EXCEPT FOR THE DOOR PENINSULA...WHICH
SHOULD OCCUR EARLY THIS AFTERNOON. SCATTERED SHOWERS WILL ACCOMPANY
THE COLD FRONT. BUT WITH DAYTIME HEATING...PROGGED SOUNDINGS
INDICATE THAT 500-800 J/KG OF CAPE COULD DEVELOP OVER NE WI AHEAD OF
THE FRONT. AS A RESULT...NOT OUT OF THE QUESTION THAT A FEW
THUNDERSTORMS COULD POP UP BY LATE IN THE MORNING ALONG THE
BOUNDARY. ANY THUNDERSTORMS WILL BE CAPABLE OF TRANSFERRING HIGHER
WINDS ALOFT TO THE SURFACE SO WILL KEEP A MENTION OF GUSTY WINDS
WITH ANY THUNDERSTORMS IN THE HWO. BEHIND THE FRONT...SOUTHWEST
WINDS WILL BECOME BREEZY IN THE AFTERNOON WITH SOME GUSTS TO 35 MPH
POSSIBLE. WRAP AROUND SHOWERS COULD ALSO MOVE INTO CENTRAL AND
NORTH-CENTRAL WI BY MID TO LATE AFTERNOON. HIGHS RANGING FROM THE
MID 60S WEST TO MID 70S EAST.
TONIGHT...THE UPPER TROUGH MOVES OVERHEAD AS THE SHORTWAVE IN THE
BASE OF THE TROUGH LIFTS NORTHWARD OVER EASTERN WISCONSIN. DEEPER
MOISTURE WILL ACCOMPANY THE TROUGH...WITH MOISTURE EXTENDING UPWARDS
OF 700MB OVERNIGHT. ANY BREAKS IN THE CLOUDS OVER EASTERN WISCONSIN
AT THE START OF THE NIGHT WILL THEREFORE LIKELY FILL IN AS THE
EVENING PROGRESSES AND WILL SPREAD A SLIGHT CHANCE OF RAIN ALL THE
WAY TO THE LAKESHORE. THE MORE PERSISTENT RAINS SHOULD FALL OVER
NORTH-CENTRAL WI WHERE A SURFACE TROUGH WILL MOVE THROUGH. LOWS
MAINLY IN THE 50S.
THURSDAY...THE UPPER TROUGH WILL CONTINUE TO BE OVERHEAD DURING THE
MORNING....WHICH SHOULD LEAD TO SCATTERED SHOWERS AND SPOTTY
DRIZZLE. THEN THE LIGHT PRECIP SHOULD COME TO AN END IN THE
AFTERNOON AS THE TROUGH LIFTS TO THE NORTHEAST. HIGHS RANGING FROM
THE LOW 60S NORTH TO LOW 70S SOUTH.
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY
ISSUED AT 305 AM CDT WED AUG 19 2015
THE TWO MAIN WEATEHR FEATURES TO KEY ON DURING THE EXTENDED PERIOD
WL BE THE MOVEMENT OF THE NEXT PROMINENT SHORTWAVE TROF/ASSOCIATED
CDFNT ACROSS THE NRN TIER OF STATES THIS WEEKEND INTO EARLY NEXT
WEEK AND THE BUILDING OF AN UPR RDG OVER THE HI PLAINS. THE MAIN
STICKING POINT AMONG THE MODELS IS WHETHER THIS SHORTWAVE TROF WL
BE PROGRESSIVE OR CLOSE OFF INTO AN UPR LOW SOMEWHERE NEAR THE
GREAT LAKES. THE ANSWER TO THIS QUESTION WOULD GO A LONG WAY IN
DETERMINING THE WEATEHR IN OUR AREA FROM SUNDAY THRU TUE. AFTER A
BRIEF WARM-UP THRU SAT...TEMPS ARE EXPECTED TO FALL BELOW NORMAL
FOR THE FIRST HALF OF NEXT WEEK.
THE GREAT LAKES REGION TO RESIDE ON THE NRN FRINGES OF AN AREA OF
HI PRES MOVING ALONG THE OHIO RIVER VALLEY THU NGT. CLEARING
SKIES...LIGHT WINDS AND AN INFLUX OF DRIER AIR SHOULD ALLOW TEMPS
TO FALL INTO THE MID 40S TO MID 50S RANGE WITH THE WARMER TEMPS
NEAR LAKE MI. WI TO GET ON THE BACKSIDE OF THIS RETREATING AREA OF
HI PRES ON FRI AS WINDS BACK TO THE S-SE. WAA WL GRADUALLY WORK
ACROSS THE AREA AS 8H TEMPS CLIMB TO AROUND +15C BY 00Z SAT. TEMPS
WL RESPOND WITH READINGS TOPPING OUT MAINLY IN THE MID 70S TO
AROUND 80 DEGS.
QUIET AND MILDER CONDITIONS EXPECTED FOR FRI NGT AS NE WI TO SIT
BETWEEN HI PRES TO OUR EAST AND DEVELOPING LOW PRES WELL TO OUR
WEST. BOUNDARY LAYER WINDS ARE FCST TO INCREASE THRU THE NGT AND
KEEP THE ATMOSPHERE MIXED...THEREBY PREVENTING TEMPS FROM FALLING
TOO FAR. LOOK FOR MINS TO RANGE FROM THE MID 50S TO AROUND 60 DEGS
NORTH...LWR 60S SOUTH. ATTENTION TO BE FOCUSED ON THE MOVEMENT OF
A SHARP SHORTWAVE TROF/ATTENDANT SFC CDFNT PROGGED TO REACH THE
NRN PLAINS ON SAT. THIS SYSTEM TO STILL BE TOO FAR AWAY TO IMPACT
NE WI...OTHER THAN BRING A BLUSTERY AND WARM DAY TO THE REGION.
MAX TEMPS WL RANGE FROM AROUND 80 DEGS NORTH/LAKESHORE...LWR 80S
SOUTH.
THE SHORTWAVE TROF TO PUSH EAST INTO THE UPR MS VALLEY SAT NGT...
AS THE CDFNT REACHES WRN WI BY DAYBREAK. EVEN THO INSTABILITY AND
FORCING ARE SOMEWHAT MARGINAL...THERE IS GOOD LIFT FROM THE CDFNT
AND THE 0-6KM BULK SHEAR VALUES ARE GREATER THAN 40 KTS
APPROACHING CNTRL WI LATE SAT NGT. HIGHEST POPS PLACED OVER CNTRL
WI WITH A POTENTIAL FOR PARTS OF ERN WI TO STAY DRY THRU THE NGT.
FCST CONFIDENCE IS A BIT BETTER NOW FOR SUNDAY AND BEYOND NOW THAT
THE 00Z ECMWF HAS KEPT THIS SHORTWAVE TROF PROGRESSIVE AND NOT TRY
TO CLOSE THE TROF INTO AN UPR LOW. PCPN CHCS WL CONT FOR SUNDAY AS
THE UPR TROF AND CDFNT MOVE THRU THE FCST AREA. TOKEN SMALL POPS
WERE LEFT IN THE FCST FOR MON AND TUE DUE TO THE UNCERTAINTY OF
THE MODELS HANDLING THIS SHORTWAVE TROF CORRECTLY. IF THE NEW 12Z
MODEL OUTPUTS ARE SIMILAR TO THE 00Z RUN...THEN POPS COULD BE
DROPPED FOR BOTH MON AND TUE WITH MORE SUNSHINE. ONE THING THAT IS
MORE CERTAIN WOULD BE THE DROP IN TEMPS BEHIND THE CDFNT FOR EARLY
NEXT WEEK. THIS WOULD BE ESPECIALLY TRUE ON MON WITH MAX TEMPS IN
THE UPR 60S TO THE LWR HALF OF THE 70S.
&&
.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 608 AM CDT WED AUG 19 2015
SHOWERS AND A FEW THUNDERSTORMS WILL IMPACT THE TAF SITES THIS
MORNING ALONG A QUICK MOVING COLD FRONT. THIS LINE OF SHOWERS COULD
POSSIBLY PRODUCE STRONG GUSTY WINDS TO AROUND 35 KNOTS. BEHIND THE
FRONT...A TIGHT PRESSURE GRADIENT WILL CAUSE GUSTY SYNOPTIC WINDS OF
25 TO 30 KNOTS DURING THE LATE MORNING AND AFTERNOON HOURS. UPPER
LEVEL LOW PRESSURE WILL MOVE OVERHEAD TONIGHT. CIGS WILL QUICKLY
FALL TO IFR/LIFR OVER CENTRAL AND NORTH-CENTRAL WI...BUT WILL NOT
CRASH UNTIL OVERNIGHT OVER THE EAST. SCATTERED SHOWERS ARE LIKELY
TONIGHT WHICH WILL TEMPORARILY DROP VSBYS TO MVFR.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
BEACH HAZARDS STATEMENT THROUGH THIS EVENING FOR WIZ022-040-050.
&&
$$
SHORT TERM.....MPC
LONG TERM......KALLAS
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS TUCSON AZ
938 AM MST WED AUG 19 2015
.SYNOPSIS...EXPECT ISOLATED THUNDERSTORMS NEAR THE INTERNATIONAL
BORDER SOUTHEAST OF TUCSON THIS AFTERNOON AND EVENING...AND ISOLATED
THUNDERSTORMS FROM TUCSON EAST AND SOUTH THURSDAY. SIGNIFICANTLY
GREATER CHANCES FOR SHOWERS AND THUNDERSTORMS WILL THEN OCCUR FRIDAY
AND CONTINUE INTO EARLY NEXT WEEK. A GRADUAL COOLING TREND WILL
PREVAIL THROUGH FRIDAY FOLLOWED BY NEAR NORMAL DAYTIME TEMPERATURES
THIS WEEKEND AND EARLY NEXT WEEK.
&&
.DISCUSSION...SIMILAR WEATHER CONDITIONS AS YESTERDAY CAN BE
ANTICIPATED FOR TODAY. MODELS STILL SUGGEST AN INCREASE IN
THUNDERSTORM ACTIVITY RETURNING TO THE AREA FRIDAY INTO EARLY NEXT
WEEK AS THE FLOW PATTERN BECOMES MORE FAVORABLE. CURRENT FORECAST
LOOKED ON TRACK...SO NO UPDATES NECESSARY THIS MORNING. PLEASE REFER
TO THE ADDITIONAL SECTIONS FOR MORE DETAILS.
&&
.AVIATION...VALID THRU 20/06Z.
SCT CIRRUS CLOUDS UNDER NW FLOW ALOFT OTRW CLR. AFT 19/21Z FEW-SCT 8-
10KFT WITH SLGT CHC OF TSTMS OVER MTNS WELL SE OF KTUS. LIGHT
TERRAIN DRIVEN WINDS EXCEPT NW 15-20 KTS SAFFORD VALLEY. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...GENERALLY DRY CONDITIONS ARE EXPECTED WITH POSSIBLE
EXCEPTION OF AN ISOLATED THUNDERSTORM FAR SOUTHERN PART OF ZONE 152
LATE TODAY. MIN RH LEVELS TODAY WILL BE THE LOWEST OF THE WEEK AND
BOTTOM OUT IN THE 15-25 PERCENT RANGE ACROSS LOWER ELEVATIONS WITH A
DECENT AFTERNOON BREEZE AGAIN THIS AFTERNOON. THE WIND WILL BE
STRONGEST IN THE GILA VALLEY ALTHOUGH A FEW MPH LESS THAN YESTERDAY.
MOISTURE WILL BEGIN TO INCREASE THURSDAY WITH ISOLATED SHOWERS AND
THUNDERSTORMS POSSIBLE...MAINLY SOUTHERN AREAS. THEN THE MOISTURE
AND THUNDERSTORMS CHANCES WILL INCREASE AND SPREAD THROUGHOUT
SOUTHEAST ARIZONA THROUGH THE WEEKEND INTO EARLY NEXT WEEK.
&&
.PREV DISCUSSION...NWLY FLOW ALOFT CONTINUES ACROSS SE ARIZONA EARLY
THIS MORNING WITH HIGH PRESSURE CENTERED NEAR THE SOUTHERN
CALIFORNIA COAST. PRECIP-FREE CONDITIONS WILL OCCUR ACROSS MUCH OF
THIS FORECAST AREA THRU TONIGHT. HOWEVER...HAVE OPTED TO INTRODUCE A
SLIGHT CHANCE OF SHOWERS/TSTMS THIS AFTERNOON AND EVENING ACROSS SRN
PORTIONS OF COCHISE COUNTY...AND THE ERN PORTION OF SANTA CRUZ
COUNTY. SEVERAL HRRR SOLUTIONS AS WELL AS THE 19/06Z NAM12 DEPICT
THE BEST CHANCE FOR MEASURABLE RAINFALL TO OCCUR ACROSS THE HUACHUCA
MOUNTAINS. ANY SHOWERS/TSTMS SHOULD DISSIPATE AROUND SUNSET OR
SHORTLY THEREAFTER.
THE UPPER HIGH IS THEN PROGGED VIA THE 19/00Z NAM/GFS/ECMWF/CMC TO
WEAKEN ON THUR...AND THE NEAR-SURFACE FLOW REGIME IS PROGGED TO
BECOME INCREASINGLY SLY/SELY...ESPECIALLY BY THUR NIGHT. HAVE
MAINTAINED ISOLATED SHOWERS/TSMTS MAINLY FROM TUCSON EWD/SWD THUR
AFTERNOON INTO THUR NIGHT. MOISTURE WILL CONTINUE TO INCREASE ACROSS
THE AREA FRI AS HIGH PRESSURE ALOFT BECOMES POSITIONED OVER FAR WEST
TEXAS.
THUS...HAVE INCREASED POPS GENERALLY 10-20 PERCENT FRI ESPECIALLY
FROM TUCSON EAST AND SOUTH VERSUS THE INHERITED FORECAST. HOWEVER
POPS FOR FRI AFTERNOON/EVENING ARE STILL SOMEWHAT LOW RELATIVE TO
SOME GUIDANCE SUCH AS THE GFSX/ECMX. AT ANY RATE...SCATTERED
SHOWERS/TSTMS SHOULD OCCUR ACROSS MUCH OF THE AREA FRI AFTERNOON/
EVENING...WITH ISOLATED SHOWERS/TSTMS ACROSS WRN SECTIONS.
SOME DECREASE IN THE COVERAGE OF SHOWERS/TSTMS IS EXPECTED SAT GIVEN
THE PROGGED VERY LIGHT MID/UPPER LEVEL FLOW REGIME. THE POTENTIAL
THEN EXISTS FOR A FAIRLY SIGNIFICANT INCREASE IN SHOWERS/TSTMS SUN-
MON DUE TO A DEEPER SELY FLOW REGIME. THE GFS/ECMWF WERE ALSO
SIMILAR WITH DEPICTING AN INVERTED TROUGH TO ENCROACH UPON FAR SERN
SECTIONS SUN NIGHT/EARLY MON. AT ANY RATE...POPS WERE TRENDED UPWARD
BASED ON THE 19/00Z GFS/ECMWF/CMC SOLUTIONS TO REFLECT THIS NOTION.
THEREAFTER...ADEQUATE MOISTURE SUGGESTS THE CONTINUATION OF CHANCE-
CATEGORY POPS ACROSS MUCH OF SE ARIZONA MON NIGHT-TUE.
HIGH TEMPS TODAY WILL BE QUITE SIMILAR TO TEMPS ACHIEVED TUE...AND
WILL AVERAGE ABOUT 2-6 DEGS F ABOVE NORMAL. SOME MINOR DAILY COOLING
WILL THEN OCCUR THUR-FRI FOLLOWED BY NEAR NORMAL DAYTIME TEMPS FOR
MUCH OF THE AREA SAT-TUE.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
230 PM EDT WED AUG 19 2015
.PREV DISCUSSION... /ISSUED 1113 AM EDT WED AUG 19 2015/
.UPDATE...
MAIN ADJUSTMENTS IN THE NEAR TERM WERE TO LOWER POP TRENDS THROUGH
MIDDAY AND FOCUS BEST CHANCE FOR SHOWERS AND STORMS IN THE
AFTERNOON/EVENING PER THE NAM 305 THETA UPGLIDE ZONES AND THE
HRRR AS THIS HI-RES SOLUTION SEEMS TO BE THE ONLY ONE LATCHING ON
TO THE LACK OF COVERAGE OBSERVED THUS FAR. STILL VERY TROPICAL
AIRMASS WITH 1.9 INCH PWAT OFF THIS MORNING SOUNDING AND JUST
OVER 2.0 INCH FOR BMX SO CONTINUING THE FLOODING THREAT AND
STRONG TO BRIEFLY SEVERE POTENTIAL WITH AFTERNOON
DESTABILIZATION.
THE BIG PLAYER FOR THIS EVENING AND OVERNIGHT WILL BE THE
EVOLUTION OF A LARGE CONVECTIVE COMPLEX CURRENTLY UPSTREAM ACROSS
LOUISIANA. THE HRRR ALSO HAS THE MCS/MCV BRINGING AT LEAST ANOTHER
ROUND OF WIDESPREAD SHOWERS BY 02-06Z TONIGHT THOUGH SOME
UNCERTAINTY WITH INTENSITY OF CONVECTION. WILL BE MONITORING THIS
FOR AFTERNOON FCST ISSUANCE AND MAY NEED TO RAISE OVERNIGHT POPS
ACCORDINGLY. PREVIOUS DISCUSSION FOLLOWS...
BAKER
&&
PREV DISCUSSION... /ISSUED 731 AM EDT WED AUG 19 2015/
PREV DISCUSSION... /ISSUED 430 AM EDT WED AUG 19 2015/
.SHORT TERM /TODAY THROUGH THURSDAY/...
MODELS IN GOOD AGREEMENT THROUGH THE SHORT TERM WITH A VERY GOOD
GULF CONNECTION SPREADING DEEP MOISTURE OVER THE CWA. THIS WILL
CONTINUE INTO WEDNESDAY KEEP SCATTERED TO WIDESPREAD SHOWERS AND
TSTORMS OVER THE CWA. THE BEST CHANCES WILL BE ACROSS NORTH GEORGIA
AND MAINLY DURING THE AFTERNOON AND EVENING HOURS. ALTHOUGH THUNDER
WILL BE MINIMAL EARLY THIS MORNING AND ALSO WEDNESDAY MORNING...
EXPECT THUNDER TO BECOME MORE NUMEROUS WITH DAYTIME HEATING THIS
AFTERNOON AND INTO THE EARLY EVENING HOURS. ALTHOUGH THE GREATEST
INSTABILITY WILL BE ACROSS NORTH GA...AN ISOLATED STRONG TO SEVERE
STORM WILL BE POSSIBLE JUST ABOUT ANYWHERE THIS AFTERNOON AND
EVENING WITH THE MAIN THREAT BEING STRONG WINDS. TEMPERATURES
THROUGH WEDNESDAY WILL BE PRETTY CLOSE TO PERSISTENCE DUE TO
CLOUDS AND PRECIP...AND THE MODELS HAVE A GOOD HANDLE ON THIS.
17
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
PATTERN STILL ON TRACK TO SHIFT TO WEAK W-E ZONAL FLOW ACROSS THE
SE CONUS LATE THIS WEEK THEN GO INTO WEAK NW FLOW ON THIS WEEKEND.
SOME INDICATIONS THAT A WEAK SHORTWAVE WILL AFFECT AREA ON SUNDAY BY
00Z MED RANGE MODELS. HAVE BUMPED POPS UP A LITTLE FROM BLEND. CHC
FOR FROPA NOW LOOKING LESS LIKELY EARLY NEXT WEEK SO IN THE SOUP
WE STAY. DAYTIME TEMPS SHOULD BE AT OR SLIGHTLY BELOW NORMAL SO
SOME CONSOLATION.
ATLANTIC BASIN HAS ITS FOURTH NAMED STORM...TS DANNY...AND COULD
AFFECT INTERESTS IN THE VIRGIN ISLANDS AND PERHAPS PUERTO RICO
NEXT WEEK AS DANNY MOVES SLOWLY WEST. NO OTHER FEATURES OF NOTE
THRU TUES.
SNELSON
17
.AVIATION...
18Z UPDATE...
INITIAL CIGS OF HIGH END MVFR TO LOW END VFR IN 2500-3500 FT
RANGE WITH SCATTERED SHOWERS AND TSRA POTENTIAL UP UNTIL 00Z OR
SLIGHTLY AFTER WITH LINGERING -SHRA POSSIBLY THRU 04Z FROM A
DISTURBANCE TRACKING ALONG THE TROPICAL SW FLOW. CIGS LOOK TO
LOWER AGAIN TO IFR SIMILAR TO PREVIOUS MORNINGS FOR 09-14Z WITH
GRADUAL IMPROVEMENT AND AGAIN CHANCE FOR PRECIP AND -TSRA
RETURNING NEAR 18Z TOMORROW. WINDS SHOULD STAY MAINLY SW TO WEST
AT 5-8 KTS WITH LIGHT TO CALM OVERNIGHT. EXPECT REDUCED VSBYS WITH
ANY TSRA IN MVFR/IFR RANGE.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM ON PRECIP TIMING AND OVERNIGHT CIGS.
HIGH ON ALL ELSE.
BAKER
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 84 71 89 72 / 70 50 60 30
ATLANTA 86 71 88 72 / 70 60 60 30
BLAIRSVILLE 79 70 82 65 / 70 70 60 30
CARTERSVILLE 86 72 86 69 / 70 60 60 30
COLUMBUS 87 74 88 74 / 70 60 60 30
GAINESVILLE 82 71 84 71 / 70 60 60 30
MACON 89 73 91 73 / 60 40 50 30
ROME 85 71 85 69 / 70 70 60 30
PEACHTREE CITY 87 71 90 71 / 70 60 60 30
VIDALIA 91 73 94 75 / 50 40 50 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...17/BAKER
LONG TERM....SNELSON
AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
424 PM EDT WED AUG 19 2015
.UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 242 PM EDT WED AUG 19 2015
TWO SYSTEMS WILL IMPACT THE WEATHER ACROSS CENTRAL INDIANA OVER
THE FORECAST PERIOD. THE FIRST IS CURRENTLY MAKING ITS WAY INTO
THE UPPER MIDWEST...AND ITS ASSOCIATED COLD FRONT WILL TRIGGER
SHOWERS AND THUNDERSTORMS ACROSS THE AREA THIS EVENING AND INTO
TONIGHT. AFTER A DRY PERIOD FROM HIGH PRESSURE THROUGH
SATURDAY...ANOTHER SYSTEM WILL INITIATE CONVECTIVE DEVELOPMENT
SUNDAY AFTERNOON AND NIGHT. FURTHER OUT...HIGH PRESSURE WILL
RETURN AT THE BEGINNING OF NEXT WEEK.
&&
.NEAR TERM /THIS EVENING AND TONIGHT/...
ISSUED AT 242 PM EDT WED AUG 19 2015
THE MAIN FOCUS OF THE NEAR TERM PERIOD IS SHOWER AND
THUNDERSTORM CHANCES AS COLD FRONT ENTERS CENTRAL INDIANA.
SYNOPTICALLY...A RATHER STRONG LOW PRESSURE SYSTEM IS CURRENTLY
ROTATING OVER THE UPPER MIDWEST WHILE ITS ASSOCIATED COLD FRONT
MAKES ITS WAY INTO NORTHWEST INDIANA. RADAR TRENDS HAVE BEEN
LEANING TOWARD INCREASING CONVECTIVE DEVELOPMENT ACROSS CENTRAL
INDIANA OVER THE LAST FEW HOURS AND WILL CONTINUE TO STRENGTHEN
THROUGH THU 06Z AS AFOREMENTIONED COLD FRONT APPROACHES CENTRAL
INDIANA.
BEST FRONTOGENETIC FORCING IN LOWER AND MID LEVELS WILL BE DURING
THE THU 06-12Z TIME FRAME FROM WEST/NORTHWEST TO EAST/SOUTHEAST
ACROSS FORECAST AREA. NONETHELESS...SUBSTANTIAL MOISTURE AND
AFTERNOON HEATING AHEAD OF THE FRONT WILL BE ENOUGH TO SUSTAIN
PRE-FRONTAL SHOWERS AND THUNDERSTORMS THIS EVENING...WITH
POTENTIAL FOR ISOLATED STRONG TO SEVERE DEVELOPMENT AT TIMES.
TEMPS WILL FALL BELOW NORMAL TONIGHT IN WAKE OF COLD FRONT WITH
OVERNIGHT LOWS DIPPING INTO THE UPPER 50S/LOW 60S. SOME MID 50S
CAN EVEN BE EXPECTED ACROSS THE NORTHWEST PORTIONS OF THE FORECAST
AREA. MODELS SEEM TO HAVE A GOOD HANDLE ON THE FRONTAL
PASSAGE...SO STUCK CLOSE TO A BLEND.
&&
.SHORT TERM /TOMORROW THROUGH SATURDAY/...
ISSUED AT 242 PM EDT WED AUG 19 2015
COLD FRONT WILL BE THROUGH THE FORECAST AREA BY THU 12Z...BUT
RESIDUAL CLOUD COVER WILL LINGER ACROSS THE EASTERN COUNTIES
TOMORROW MORNING UNTIL THE ASSOCIATED UPPER LOW PUSHES FARTHER
EAST. AFTER THAT...FLOW WILL BECOME MORE ZONAL ALOFT AND HIGH
PRESSURE WILL STRENGTHEN AT THE SURFACE OVER THE OHIO VALLEY.
SO...DRY CONDITIONS CAN BE EXPECTED INTO SATURDAY.
TEMPERATURES WILL START OUT WELL BELOW NORMAL FOR THE FIRST HALF
OF THE SHORT TERM PERIOD AS THEY TRY TO REBOUND FROM THE
AFOREMENTIONED COLD FRONT. SO...HIGHS WILL ONLY BE IN THE MID TO
UPPER 70S FOR THURSDAY...AND UPPER 70S/LOW 80S BY FRIDAY. THEY
WILL START TO RECOVER BY SATURDAY THOUGH WITH MORE WIDESPREAD LOW
80S. MEANWHILE...DECENT RADIATIONAL COOLING AT NIGHT WILL KEEP
LOWS SIGNIFICANTLY BELOW NORMAL WITH READINGS IN THE 50S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
ISSUED AT 201 PM EDT WED AUG 19 2015
ECMWF AND GFS BLEND PRETTY WELL DURING THE PERIOD. BOTH MODELS
SUGGEST A DECENT COLD FRONT ALONG WITH A SHORT WAVE ALOFT PASSING
THROUGH CENTRAL INDIANA ON SUNDAY NIGHT INTO EARLY MONDAY. A WARM
AND MOIST AIR MASS ALONG WITH SOUTHERLY FLOW MAY ALSO LEAD TO SOME
AFTERNOON PEAK HEATING DAYTIME CONVECTION ACROSS CENTRAL INDIANA.
THUS HAVE INCLUDED POPS STARTING SUNDAY AFTERNOON THROUGH LATE
SUNDAY NIGHT.
HIGH PRESSURE LOOKS TO RETURN TO THE AREA ON MONDAY AND NORTHWEST
FLOW RESUMES ALOFT AND AN UPPER LOW CONTINUE TO PULL NORTHEAST
TOWARD QUEBEC. THIS ALONG WITH HIGH PRESSURE IN PLACE AT THE
SURFACE WILL ALLOW FOR SUBSIDENCE AND DRY WEATHER ACROSS CENTRAL
INDIANA.
LOOK FOR TEMPS TO BE AT OR BELOW NORMALS THROUGH THIS PERIOD AS
NORTHWEST FLOW IS EXPECTED TO PERSIST THROUGH MUCH OF THE PERIOD.
&&
.AVIATION /DISCUSSION FOR THE 192100Z TAF UPDATE/...
ISSUED AT 424 PM EDT WED AUG 19 2015
BULK OF TSRA REMAINS WELL SOUTH OF KIND...AND RECENT TRENDS INDICATE
THAT THIS WILL CONTINUE THE NEXT FEW HOURS. HAVE THUS CHANGED VCTS
TO VCSH FOR THE NEXT FEW HOURS. STILL EXPECTING SOME DEVELOPMENT OF
TSRA WITH COLD FRONT THIS EVENING SO LEFT TEMPO TSRA GROUP IN FOR
NOW.
PREVIOUS DISCUSSION FOLLOWS...
VFR CONDITIONS EXPECTED FOR THE NEXT FEW HOURS. MVFR CONDITIONS WILL
BE EXPECTED THIS AFTERNOON AND OVERNIGHT. A RETURN TO VFR IS
EXPECTED AFTER 14Z THURSDAY.
CONVECTIVE TEMPS IN THE LOWER 80S ARE EXPECTED TO BE REACHED
MOMENTARILY. TSRA DEVELOPMENT IS EXPECTED ACROSS SOUTHERN
ILLINOIS AND WESTERN INDIANA AHEAD OF THE APPROACHING FRONTAL
BOUNDARY. HRRR SHOWS AREAS OF THUNDERSTORMS DEVELOPING AND
PUSHING ACROSS CENTRAL INDIANA DURING THE PEAK HEATING HOURS AND
EARLY THIS EVENING. THUS WILL INCLUDE A PERIOD OF VCSH ALONG WITH
A TEMPO PERIOD FOR THUNDER DURING THE MOST FAVORABLE WINDOW FOR
THUNDERSTORMS.
AFTER DYNAMICS AND FORCING MOVES EAST AFTER 06Z...FORECAST
SOUNDINGS AND TIME HEIGHTS ALONG WITH THE SUGGESTION OF RECENT
RAINS INDICATE LOWER LEVEL MOISTURE AND STRATOCU/MVFR FOG
LINGERING OVERNIGHT.
AS HIGH PRESSURE ARRIVES IN THE AREA ON THURSDAY ALONG WITH
SUBSIDENCE...A QUICK RETURN TO VFR IS EXPECTED.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM....PUMA
AVIATION...JP/50
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
359 PM EDT WED AUG 19 2015
.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 242 PM EDT WED AUG 19 2015
TWO SYSTEMS WILL IMPACT THE WEATHER ACROSS CENTRAL INDIANA OVER
THE FORECAST PERIOD. THE FIRST IS CURRENTLY MAKING ITS WAY INTO
THE UPPER MIDWEST...AND ITS ASSOCIATED COLD FRONT WILL TRIGGER
SHOWERS AND THUNDERSTORMS ACROSS THE AREA THIS EVENING AND INTO
TONIGHT. AFTER A DRY PERIOD FROM HIGH PRESSURE THROUGH
SATURDAY...ANOTHER SYSTEM WILL INITIATE CONVECTIVE DEVELOPMENT
SUNDAY AFTERNOON AND NIGHT. FURTHER OUT...HIGH PRESSURE WILL
RETURN AT THE BEGINNING OF NEXT WEEK.
&&
.NEAR TERM /THIS EVENING AND TONIGHT/...
ISSUED AT 242 PM EDT WED AUG 19 2015
THE MAIN FOCUS OF THE NEAR TERM PERIOD IS SHOWER AND
THUNDERSTORM CHANCES AS COLD FRONT ENTERS CENTRAL INDIANA.
SYNOPTICALLY...A RATHER STRONG LOW PRESSURE SYSTEM IS CURRENTLY
ROTATING OVER THE UPPER MIDWEST WHILE ITS ASSOCIATED COLD FRONT
MAKES ITS WAY INTO NORTHWEST INDIANA. RADAR TRENDS HAVE BEEN
LEANING TOWARD INCREASING CONVECTIVE DEVELOPMENT ACROSS CENTRAL
INDIANA OVER THE LAST FEW HOURS AND WILL CONTINUE TO STRENGTHEN
THROUGH THU 06Z AS AFOREMENTIONED COLD FRONT APPROACHES CENTRAL
INDIANA.
BEST FRONTOGENETIC FORCING IN LOWER AND MID LEVELS WILL BE DURING
THE THU 06-12Z TIME FRAME FROM WEST/NORTHWEST TO EAST/SOUTHEAST
ACROSS FORECAST AREA. NONETHELESS...SUBSTANTIAL MOISTURE AND
AFTERNOON HEATING AHEAD OF THE FRONT WILL BE ENOUGH TO SUSTAIN
PRE-FRONTAL SHOWERS AND THUNDERSTORMS THIS EVENING...WITH
POTENTIAL FOR ISOLATED STRONG TO SEVERE DEVELOPMENT AT TIMES.
TEMPS WILL FALL BELOW NORMAL TONIGHT IN WAKE OF COLD FRONT WITH
OVERNIGHT LOWS DIPPING INTO THE UPPER 50S/LOW 60S. SOME MID 50S
CAN EVEN BE EXPECTED ACROSS THE NORTHWEST PORTIONS OF THE FORECAST
AREA. MODELS SEEM TO HAVE A GOOD HANDLE ON THE FRONTAL
PASSAGE...SO STUCK CLOSE TO A BLEND.
&&
.SHORT TERM /TOMORROW THROUGH SATURDAY/...
ISSUED AT 242 PM EDT WED AUG 19 2015
COLD FRONT WILL BE THROUGH THE FORECAST AREA BY THU 12Z...BUT
RESIDUAL CLOUD COVER WILL LINGER ACROSS THE EASTERN COUNTIES
TOMORROW MORNING UNTIL THE ASSOCIATED UPPER LOW PUSHES FARTHER
EAST. AFTER THAT...FLOW WILL BECOME MORE ZONAL ALOFT AND HIGH
PRESSURE WILL STRENGTHEN AT THE SURFACE OVER THE OHIO VALLEY.
SO...DRY CONDITIONS CAN BE EXPECTED INTO SATURDAY.
TEMPERATURES WILL START OUT WELL BELOW NORMAL FOR THE FIRST HALF
OF THE SHORT TERM PERIOD AS THEY TRY TO REBOUND FROM THE
AFOREMENTIONED COLD FRONT. SO...HIGHS WILL ONLY BE IN THE MID TO
UPPER 70S FOR THURSDAY...AND UPPER 70S/LOW 80S BY FRIDAY. THEY
WILL START TO RECOVER BY SATURDAY THOUGH WITH MORE WIDESPREAD LOW
80S. MEANWHILE...DECENT RADIATIONAL COOLING AT NIGHT WILL KEEP
LOWS SIGNIFICANTLY BELOW NORMAL WITH READINGS IN THE 50S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
ISSUED AT 201 PM EDT WED AUG 19 2015
ECMWF AND GFS BLEND PRETTY WELL DURING THE PERIOD. BOTH MODELS
SUGGEST A DECENT COLD FRONT ALONG WITH A SHORT WAVE ALOFT PASSING
THROUGH CENTRAL INDIANA ON SUNDAY NIGHT INTO EARLY MONDAY. A WARM
AND MOIST AIR MASS ALONG WITH SOUTHERLY FLOW MAY ALSO LEAD TO SOME
AFTERNOON PEAK HEATING DAYTIME CONVECTION ACROSS CENTRAL INDIANA.
THUS HAVE INCLUDED POPS STARTING SUNDAY AFTERNOON THROUGH LATE
SUNDAY NIGHT.
HIGH PRESSURE LOOKS TO RETURN TO THE AREA ON MONDAY AND NORTHWEST
FLOW RESUMES ALOFT AND AN UPPER LOW CONTINUE TO PULL NORTHEAST
TOWARD QUEBEC. THIS ALONG WITH HIGH PRESSURE IN PLACE AT THE
SURFACE WILL ALLOW FOR SUBSIDENCE AND DRY WEATHER ACROSS CENTRAL
INDIANA.
LOOK FOR TEMPS TO BE AT OR BELOW NORMALS THROUGH THIS PERIOD AS
NORTHWEST FLOW IS EXPECTED TO PERSIST THROUGH MUCH OF THE PERIOD.
&&
.AVIATION /DISCUSSION FOR THE 191800Z IND TAFS/...
ISSUED AT 116 PM EDT WED AUG 19 2015
VFR CONDITIONS EXPECTED FOR THE NEXT FEW HOURS. MVFR CONDITIONS
WILL BE EXPECTED THIS AFTERNOON AND OVERNIGHT. A RETURN TO VFR IS
EXPECTED AFTER 14Z THURSDAY.
CONVECTIVE TEMPS IN THE LOWER 80S ARE EXPECTED TO BE REACHED
MOMENTARILY. TSRA DEVELOPMENT IS EXPECTED ACROSS SOUTHERN
ILLINOIS AND WESTERN INDIANA AHEAD OF THE APPROACHING FRONTAL
BOUNDARY. HRRR SHOWS AREAS OF THUNDERSTORMS DEVELOPING AND
PUSHING ACROSS CENTRAL INDIANA DURING THE PEAK HEATING HOURS AND
EARLY THIS EVENING. THUS WILL INCLUDE A PERIOD OF VCSH ALONG WITH
A TEMPO PERIOD FOR THUNDER DURING THE MOST FAVORABLE WINDOW FOR
THUNDERSTORMS.
AFTER DYNAMICS AND FORCING MOVES EAST AFTER 06Z...FORECAST
SOUNDINGS AND TIME HEIGHTS ALONG WITH THE SUGGESTION OF RECENT
RAINS INDICATE LOWER LEVEL MOISTURE AND STRATOCU/MVFR FOG
LINGERING OVERNIGHT.
AS HIGH PRESSURE ARRIVES IN THE AREA ON THURSDAY ALONG WITH
SUBSIDENCE...A QUICK RETURN TO VFR IS EXPECTED.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM....PUMA
AVIATION...JP
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
208 PM EDT WED AUG 19 2015
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 218 AM EDT WED AUG 19 2015
A STRONG FRONTAL SYSTEM...FOR THIS TIME OF YEAR...WILL BRING
WIDESPREAD THUNDERSTORMS TO CENTRAL INDIANA TODAY AND TONIGHT. SOME
OF THE STORMS COULD BE STRONG OR POSSIBLY EVEN SEVERE. THEN...HIGH
PRESSURE WILL PROVIDE FOR DRY CONDITIONS THROUGH SATURDAY. ANOTHER
SEASONABLY STRONG FRONTAL SYSTEM WILL BRING MORE STORMS TO THE AREA
SUNDAY AND SUNDAY NIGHT BEFORE HIGH PRESSURE AND DRY WEATHER RETURN
MONDAY.
TEMPERATURES WILL BE BELOW NORMAL...ESPECIALLY LATE THIS WORK WEEK
AND EARLY NEXT WEEK FOLLOWING THE FRONTAL PASSAGES...WHEN HIGHS WILL
BE IN THE 70S AND LOWS IN THE 50S.
&&
.NEAR TERM /REST OF TODAY AND TONIGHT/...
ISSUED AT 947 AM EDT WED AUG 19 2015
UPDATE...
LATEST RADAR MOSAIC SHOWS SCATTERED SHOWERS CONFINED TO THE FAR
SOUTHERN TIER OF COUNTIES IN CENTRAL INDIANA. THIS CORRELATES WELL
WITH LOCATION OF BEST INSTABILITY AT THIS HOUR. CONVECTIVE
ACTIVITY IS STILL EXPECTED TO BECOME MORE WIDESPREAD AND STRONGER
THROUGH THE COURSE OF THE AFTERNOON AS COLD FRONT APPROACHES FROM
THE WEST. PLUS...THE FIRST WAVE OF SHOWERS AND THUNDERSTORMS HAVE
STAYED FARTHER SOUTH THAN ORIGINALLY ANTICIPATED. SO...WITH MORE
BREAKS IN CLOUD COVER...THE FRONT MAY HAVE MORE INSTABILITY TO
WORK WITH ACROSS THE NORTHERN TWO-THIRDS OF THE FORECAST AREA
LATER TODAY.
CURRENT TEMPS ACROSS THE AREA ARE GENERALLY IN THE 70S WITH
DEWPOINTS IN THE MID TO UPPER 60S. WINDS ARE SOUTH/SOUTHWESTERLY
AT 10 TO 14 MPH...GUSTING TO 21 MPH.
PREVIOUS DISCUSSIONS...
ISSUED AT 620 AM EDT WED AUG 19 2015
LATEST RADAR TRENDS ARE BRINGING WIDESPREAD SHOWERS AND EMBEDDED
THUNDERSTORMS TO ABOUT AN INDIANAPOLIS TO LAFAYETTE LINE AROUND 8
AM. RAISED POPS TO CATEGORICAL SLIGHTLY EARLIER. FIRST WAVE OF
STORMS SHOULD BE EAST OF THE AREA AROUND 16Z WITH STORMS DEVELOPING
AND ALSO MOVING IN FROM THE WEST SHORTLY THEREAFTER. THIS SHOULD
KEEP THINGS FROM BECOMING TO UNSTABLE AND SUPPORTS THE MARGINAL
SEVERE RISK AS OPPOSED TO SLIGHT RISK.
PREVIOUS DISCUSSION FOLLOWS...
ISSUED AT 218 AM EDT WED AUG 19 2015
THUNDERSTORMS...SOME STRONG AND POSSIBLY SEVERE...WILL BE THE MAIN
FOCUS FOR THE NEAR TERM AS A STRONG LOW PRESSURE SYSTEM...FOR LATE
AUGUST...LIFTS NORTHEAST ACROSS LAKE SUPERIOR AND NORTHWEST ONTARIO
DRAGGING A COLD FRONT ACROSS CENTRAL INDIANA.
RAP13 AND HIGH RES RAPID REFRESH SEEM TO HAVE A DECENT HANDLE ON
CONVECTIVE EVOLUTION COMPARED TO THE LATEST RADAR TRENDS.
THUNDERSTORMS WERE LIFTING NORTHEAST OVER NORTHWESTERN PARTS OF
CENTRAL INDIANA EARLY THIS OVERNIGHT AND THE REFLECTIVITY PROGS FROM
THE RAPID REFRESH WERE BRINGING THE INDIVIDUAL STORMS NORTHEAST BUT
THE AREA OF CONVECTION SOUTHEAST AHEAD OF A COLD FRONT THAT EXTENDED
FROM A SURFACE LOW OVER SOUTH CENTRAL MINNESOTA TO NORTHEASTERN
MISSOURI AND NORTHEASTERN OKLAHOMA. THE GFS CONTINUES TO BE A FAST
OUTLIER WITH ITS 00Z WEDNESDAY RUN WITH REGARDS TO THE FRONTAL
PASSAGE OVER CENTRAL INDIANA AND THUS WILL BE IGNORED WITH A BLEND
BETWEEN THE OTHER SIMILAR OPERATIONAL MODELS ACCEPTED. NON-GFS BLEND
TAKES THE COLD FRONT TO NEAR CHICAGO TO ST. LOUIS LINE 12Z THIS
MORNING...TO A VALPO TO CARBONDALE LINE AT 18Z AND TO AROUND A FORT
WAYNE TO INDIANAPOLIS LINE BY 00Z THURSDAY. MEANWHILE...THE FRONT
SHOULD BE THROUGH CENTRAL OHIO AND EASTERN KENTUCKY BY 12Z THURSDAY
WHICH SHOULD PUT AN END TO THE CONVECTION FROM NORTHWEST TO
SOUTHEAST OVERNIGHT TONIGHT. HOWEVER...PRIOR TO THAT...THE RAPID
REFRESH WAS BRINGING EASTERN MISSOURI STORMS OVER CENTRAL INDIANA IN
THE 11Z-15Z TIME FRAME. MEANWHILE...MORE WIDESPREAD STORMS ARE
EXPECTED THIS AFTERNOON AS THE FRONT GETS CLOSER.
MODELS MAY BE OVERDOING IT A LITTLE ON INSTABILITY AS BREAK BETWEEN
MORNING AND AFTERNOON CONVECTION SHOULD NOT BE TOO LONG. THAT
SAID...EVEN THE LEAST UNSTABLE ECMWF HAD 500 J/KG OR MORE MIXED
LAYER CAPE TODAY TO GO ALONG WITH THE DYNAMICS. 20-30 KNOT LOW LEVEL
JET ACROSS WEST CENTRAL INDIANA AND APPROACHING NEGATIVELY-TILTED
TROUGH SUGGESTS LIKELY TO CATEGORICAL POPS THROUGH THIS EVENING
BEFORE DROPPING OFF FROM NORTHWEST TO SOUTHEAST LATE TONIGHT. FAST
UPPER JET AROUND THE BASE OF THE TROUGH WILL PUSH INDIVIDUAL CELLS
THROUGH QUICKLY...SO DO NOT FORESEE A BIG FLASH FLOOD THREAT DESPITE
THE DYNAMICS AND PRECIPITABLE WATER AMOUNTS TO 2 INCHES. REGARDING
SEVERE THREAT...AREA CONTINUES TO BE IN A MARGINAL RISK FOR THIS
AFTERNOON AND EVENING. THIS LOOKS REASONABLE. ISOLATED DAMAGING
WINDS WILL BE THE MAIN SEVERE THREAT.
WITH LITTLE BREAKS IN THE CLOUDS TODAY...WENT WITH THE COOLEST 00Z
NAM MOS WITH HIGHS IN THE UPPER 70S AND LOWER 80S. MOS LOWS CLOSE
TONIGHT AND LOOK REASONABLE. COOLEST TEMPERATURES WILL BE
NORTHWESTERN PARTS...WHERE BREAKS IN THE CLOUDS WILL OCCUR FIRST
BEHIND THE FRONT. WILL BE A LITTLE CHILLY WITH LOWS IN THE UPPER 50S
TO LOWER 60S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
ISSUED AT 218 AM EDT WED AUG 19 2015
MAIN FOCUS FOR THE SHORT TERM WILL BE ON TEMPERATURES AS SURFACE
HIGH PRESSURE BUILDS OVER THE OHIO VALLEY BY LATE THURSDAY BEHIND
THE COLD FRONT AND TRAILING UPPER TROUGH ALLOWING FOR CLEAR SKIES
AND COOL TEMPERATURES FOR THIS TIME OF YEAR. THE HIGH WILL SHIFT TO
SOUTHERN ONTARIO BY FRIDAY NIGHT...BUT DRY COLUMN AND FRONTAL SYSTEM
WELL TO THE WEST SHOULD ENSURE DRY WEATHER.
LOW LEVEL THERMAL PROGS AND LITTLE CLOUD COVER SUPPORT SIMILAR BLEND
OF 00Z MOS WITH AFTERNOON HIGHS IN THE MID AND UPPER 70S ON THURSDAY
AND UPPER 70S TO LOWER 80S ON FRIDAY. WITH STRONG RADIATIONAL
COOLING...IT WILL BE QUITE COOL WITH OVERNIGHT LOWS IN THE 50S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
ISSUED AT 201 PM EDT WED AUG 19 2015
ECMWF AND GFS BLEND PRETTY WELL DURING THE PERIOD. BOTH MODELS
SUGGEST A DECENT COLD FRONT ALONG WITH A SHORT WAVE ALOFT PASSING
THROUGH CENTRAL INDIANA ON SUNDAY NIGHT INTO EARLY MONDAY. A WARM
AND MOIST AIR MASS ALONG WITH SOUTHERLY FLOW MAY ALSO LEAD TO SOME
AFTERNOON PEAK HEATING DAYTIME CONVECTION ACROSS CENTRAL INDIANA.
THUS HAVE INCLUDED POPS STARTING SUNDAY AFTERNOON THROUGH LATE
SUNDAY NIGHT.
HIGH PRESSURE LOOKS TO RETURN TO THE AREA ON MONDAY AND NORTHWEST
FLOW RESUMES ALOFT AND AN UPPER LOW CONTINUE TO PULL NORTHEAST
TOWARD QUEBEC. THIS ALONG WITH HIGH PRESSURE IN PLACE AT THE
SURFACE WILL ALLOW FOR SUBSIDENCE AND DRY WEATHER ACROSS CENTRAL
INDIANA.
LOOK FOR TEMPS TO BE AT OR BELOW NORMALS THROUGH THIS PERIOD AS
NORTHWEST FLOW IS EXPECTED TO PERSIST THROUGH MUCH OF THE PERIOD.
&&
.AVIATION /DISCUSSION FOR THE 191800Z IND TAFS/...
ISSUED AT 116 PM EDT WED AUG 19 2015
VFR CONDITIONS EXPECTED FOR THE NEXT FEW HOURS. MVFR CONDITIONS
WILL BE EXPECTED THIS AFTERNOON AND OVERNIGHT. A RETURN TO VFR IS
EXPECTED AFTER 14Z THURSDAY.
CONVECTIVE TEMPS IN THE LOWER 80S ARE EXPECTED TO BE REACHED
MOMENTARILY. TSRA DEVELOPMENT IS EXPECTED ACROSS SOUTHERN
ILLINOIS AND WESTERN INDIANA AHEAD OF THE APPROACHING FRONTAL
BOUNDARY. HRRR SHOWS AREAS OF THUNDERSTORMS DEVELOPING AND
PUSHING ACROSS CENTRAL INDIANA DURING THE PEAK HEATING HOURS AND
EARLY THIS EVENING. THUS WILL INCLUDE A PERIOD OF VCSH ALONG WITH
A TEMPO PERIOD FOR THUNDER DURING THE MOST FAVORABLE WINDOW FOR
THUNDERSTORMS.
AFTER DYNAMICS AND FORCING MOVES EAST AFTER 06Z...FORECAST
SOUNDINGS AND TIME HEIGHTS ALONG WITH THE SUGGESTION OF RECENT
RAINS INDICATE LOWER LEVEL MOISTURE AND STRATOCU/MVFR FOG
LINGERING OVERNIGHT.
AS HIGH PRESSURE ARRIVES IN THE AREA ON THURSDAY ALONG WITH
SUBSIDENCE...A QUICK RETURN TO VFR IS EXPECTED.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...MK/TDUD
SHORT TERM...MK
LONG TERM....PUMA
AVIATION...JP
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
116 PM EDT WED AUG 19 2015
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 218 AM EDT WED AUG 19 2015
A STRONG FRONTAL SYSTEM...FOR THIS TIME OF YEAR...WILL BRING
WIDESPREAD THUNDERSTORMS TO CENTRAL INDIANA TODAY AND TONIGHT. SOME
OF THE STORMS COULD BE STRONG OR POSSIBLY EVEN SEVERE. THEN...HIGH
PRESSURE WILL PROVIDE FOR DRY CONDITIONS THROUGH SATURDAY. ANOTHER
SEASONABLY STRONG FRONTAL SYSTEM WILL BRING MORE STORMS TO THE AREA
SUNDAY AND SUNDAY NIGHT BEFORE HIGH PRESSURE AND DRY WEATHER RETURN
MONDAY.
TEMPERATURES WILL BE BELOW NORMAL...ESPECIALLY LATE THIS WORK WEEK
AND EARLY NEXT WEEK FOLLOWING THE FRONTAL PASSAGES...WHEN HIGHS WILL
BE IN THE 70S AND LOWS IN THE 50S.
&&
.NEAR TERM /REST OF TODAY AND TONIGHT/...
ISSUED AT 947 AM EDT WED AUG 19 2015
UPDATE...
LATEST RADAR MOSAIC SHOWS SCATTERED SHOWERS CONFINED TO THE FAR
SOUTHERN TIER OF COUNTIES IN CENTRAL INDIANA. THIS CORRELATES WELL
WITH LOCATION OF BEST INSTABILITY AT THIS HOUR. CONVECTIVE
ACTIVITY IS STILL EXPECTED TO BECOME MORE WIDESPREAD AND STRONGER
THROUGH THE COURSE OF THE AFTERNOON AS COLD FRONT APPROACHES FROM
THE WEST. PLUS...THE FIRST WAVE OF SHOWERS AND THUNDERSTORMS HAVE
STAYED FARTHER SOUTH THAN ORIGINALLY ANTICIPATED. SO...WITH MORE
BREAKS IN CLOUD COVER...THE FRONT MAY HAVE MORE INSTABILITY TO
WORK WITH ACROSS THE NORTHERN TWO-THIRDS OF THE FORECAST AREA
LATER TODAY.
CURRENT TEMPS ACROSS THE AREA ARE GENERALLY IN THE 70S WITH
DEWPOINTS IN THE MID TO UPPER 60S. WINDS ARE SOUTH/SOUTHWESTERLY
AT 10 TO 14 MPH...GUSTING TO 21 MPH.
PREVIOUS DISCUSSIONS...
ISSUED AT 620 AM EDT WED AUG 19 2015
LATEST RADAR TRENDS ARE BRINGING WIDESPREAD SHOWERS AND EMBEDDED
THUNDERSTORMS TO ABOUT AN INDIANAPOLIS TO LAFAYETTE LINE AROUND 8
AM. RAISED POPS TO CATEGORICAL SLIGHTLY EARLIER. FIRST WAVE OF
STORMS SHOULD BE EAST OF THE AREA AROUND 16Z WITH STORMS DEVELOPING
AND ALSO MOVING IN FROM THE WEST SHORTLY THEREAFTER. THIS SHOULD
KEEP THINGS FROM BECOMING TO UNSTABLE AND SUPPORTS THE MARGINAL
SEVERE RISK AS OPPOSED TO SLIGHT RISK.
PREVIOUS DISCUSSION FOLLOWS...
ISSUED AT 218 AM EDT WED AUG 19 2015
THUNDERSTORMS...SOME STRONG AND POSSIBLY SEVERE...WILL BE THE MAIN
FOCUS FOR THE NEAR TERM AS A STRONG LOW PRESSURE SYSTEM...FOR LATE
AUGUST...LIFTS NORTHEAST ACROSS LAKE SUPERIOR AND NORTHWEST ONTARIO
DRAGGING A COLD FRONT ACROSS CENTRAL INDIANA.
RAP13 AND HIGH RES RAPID REFRESH SEEM TO HAVE A DECENT HANDLE ON
CONVECTIVE EVOLUTION COMPARED TO THE LATEST RADAR TRENDS.
THUNDERSTORMS WERE LIFTING NORTHEAST OVER NORTHWESTERN PARTS OF
CENTRAL INDIANA EARLY THIS OVERNIGHT AND THE REFLECTIVITY PROGS FROM
THE RAPID REFRESH WERE BRINGING THE INDIVIDUAL STORMS NORTHEAST BUT
THE AREA OF CONVECTION SOUTHEAST AHEAD OF A COLD FRONT THAT EXTENDED
FROM A SURFACE LOW OVER SOUTH CENTRAL MINNESOTA TO NORTHEASTERN
MISSOURI AND NORTHEASTERN OKLAHOMA. THE GFS CONTINUES TO BE A FAST
OUTLIER WITH ITS 00Z WEDNESDAY RUN WITH REGARDS TO THE FRONTAL
PASSAGE OVER CENTRAL INDIANA AND THUS WILL BE IGNORED WITH A BLEND
BETWEEN THE OTHER SIMILAR OPERATIONAL MODELS ACCEPTED. NON-GFS BLEND
TAKES THE COLD FRONT TO NEAR CHICAGO TO ST. LOUIS LINE 12Z THIS
MORNING...TO A VALPO TO CARBONDALE LINE AT 18Z AND TO AROUND A FORT
WAYNE TO INDIANAPOLIS LINE BY 00Z THURSDAY. MEANWHILE...THE FRONT
SHOULD BE THROUGH CENTRAL OHIO AND EASTERN KENTUCKY BY 12Z THURSDAY
WHICH SHOULD PUT AN END TO THE CONVECTION FROM NORTHWEST TO
SOUTHEAST OVERNIGHT TONIGHT. HOWEVER...PRIOR TO THAT...THE RAPID
REFRESH WAS BRINGING EASTERN MISSOURI STORMS OVER CENTRAL INDIANA IN
THE 11Z-15Z TIME FRAME. MEANWHILE...MORE WIDESPREAD STORMS ARE
EXPECTED THIS AFTERNOON AS THE FRONT GETS CLOSER.
MODELS MAY BE OVERDOING IT A LITTLE ON INSTABILITY AS BREAK BETWEEN
MORNING AND AFTERNOON CONVECTION SHOULD NOT BE TOO LONG. THAT
SAID...EVEN THE LEAST UNSTABLE ECMWF HAD 500 J/KG OR MORE MIXED
LAYER CAPE TODAY TO GO ALONG WITH THE DYNAMICS. 20-30 KNOT LOW LEVEL
JET ACROSS WEST CENTRAL INDIANA AND APPROACHING NEGATIVELY-TILTED
TROUGH SUGGESTS LIKELY TO CATEGORICAL POPS THROUGH THIS EVENING
BEFORE DROPPING OFF FROM NORTHWEST TO SOUTHEAST LATE TONIGHT. FAST
UPPER JET AROUND THE BASE OF THE TROUGH WILL PUSH INDIVIDUAL CELLS
THROUGH QUICKLY...SO DO NOT FORESEE A BIG FLASH FLOOD THREAT DESPITE
THE DYNAMICS AND PRECIPITABLE WATER AMOUNTS TO 2 INCHES. REGARDING
SEVERE THREAT...AREA CONTINUES TO BE IN A MARGINAL RISK FOR THIS
AFTERNOON AND EVENING. THIS LOOKS REASONABLE. ISOLATED DAMAGING
WINDS WILL BE THE MAIN SEVERE THREAT.
WITH LITTLE BREAKS IN THE CLOUDS TODAY...WENT WITH THE COOLEST 00Z
NAM MOS WITH HIGHS IN THE UPPER 70S AND LOWER 80S. MOS LOWS CLOSE
TONIGHT AND LOOK REASONABLE. COOLEST TEMPERATURES WILL BE
NORTHWESTERN PARTS...WHERE BREAKS IN THE CLOUDS WILL OCCUR FIRST
BEHIND THE FRONT. WILL BE A LITTLE CHILLY WITH LOWS IN THE UPPER 50S
TO LOWER 60S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
ISSUED AT 218 AM EDT WED AUG 19 2015
MAIN FOCUS FOR THE SHORT TERM WILL BE ON TEMPERATURES AS SURFACE
HIGH PRESSURE BUILDS OVER THE OHIO VALLEY BY LATE THURSDAY BEHIND
THE COLD FRONT AND TRAILING UPPER TROUGH ALLOWING FOR CLEAR SKIES
AND COOL TEMPERATURES FOR THIS TIME OF YEAR. THE HIGH WILL SHIFT TO
SOUTHERN ONTARIO BY FRIDAY NIGHT...BUT DRY COLUMN AND FRONTAL SYSTEM
WELL TO THE WEST SHOULD ENSURE DRY WEATHER.
LOW LEVEL THERMAL PROGS AND LITTLE CLOUD COVER SUPPORT SIMILAR BLEND
OF 00Z MOS WITH AFTERNOON HIGHS IN THE MID AND UPPER 70S ON THURSDAY
AND UPPER 70S TO LOWER 80S ON FRIDAY. WITH STRONG RADIATIONAL
COOLING...IT WILL BE QUITE COOL WITH OVERNIGHT LOWS IN THE 50S.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
ISSUED AT 307 AM EDT WED AUG 19 2015
HIGH PRESSURE WILL MOVE NORTHEAST AWAY FROM CENTRAL INDIANA ON
SATURDAY NIGHT ALLOWING A LOW PRESSURE SYSTEM AND ASSOCIATED COLD
FRONT TO SLIDE INTO THE AREA ON SUNDAY. MODELS HAVE TRENDED A
LITTLE SLOWER WITH THE ARRIVAL OF THIS SYSTEM AND THUS SATURDAY
NIGHT NOW LOOKS DRY. THE AFOREMENTIONED COLD FRONT WILL BRING
THUNDERSTORM CHANCES FOR SUNDAY AND SUNDAY NIGHT TO THE AREA. BY
MONDAY THOUGH CANADIAN HIGH PRESSURE WILL BUILD BACK IN OVER
CENTRAL INDIANA AND USHER IN BELOW NORMAL HIGHS IN THE 70S ALONG
WITH DRY WEATHER.
&&
.AVIATION /DISCUSSION FOR THE 191800Z IND TAFS/...
ISSUED AT 116 PM EDT WED AUG 19 2015
VFR CONDITIONS EXPECTED FOR THE NEXT FEW HOURS. MVFR CONDITIONS
WILL BE EXPECTED THIS AFTERNOON AND OVERNIGHT. A RETURN TO VFR IS
EXPECTED AFTER 14Z THURSDAY.
CONVECTIVE TEMPS IN THE LOWER 80S ARE EXPECTED TO BE REACHED
MOMENTARILY. TSRA DEVELOPMENT IS EXPECTED ACROSS SOUTHERN
ILLINOIS AND WESTERN INDIANA AHEAD OF THE APPROACHING FRONTAL
BOUNDARY. HRRR SHOWS AREAS OF THUNDERSTORMS DEVELOPING AND
PUSHING ACROSS CENTRAL INDIANA DURING THE PEAK HEATING HOURS AND
EARLY THIS EVENING. THUS WILL INCLUDE A PERIOD OF VCSH ALONG WITH
A TEMPO PERIOD FOR THUNDER DURING THE MOST FAVORABLE WINDOW FOR
THUNDERSTORMS.
AFTER DYNAMICS AND FORCING MOVES EAST AFTER 06Z...FORECAST
SOUNDINGS AND TIME HEIGHTS ALONG WITH THE SUGGESTION OF RECENT
RAINS INDICATE LOWER LEVEL MOISTURE AND STRATOCU/MVFR FOG
LINGERING OVERNIGHT.
AS HIGH PRESSURE ARRIVES IN THE AREA ON THURSDAY ALONG WITH
SUBSIDENCE...A QUICK RETURN TO VFR IS EXPECTED.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...MK/TDUD
SHORT TERM...MK
LONG TERM....CP
AVIATION...JP
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
257 PM CDT WED AUG 19 2015
. DISCUSSION... FOR A THIRD DAY IN A ROW...A LARGE SWATH OF RAIN HAS
MOVED NORTHEAST OUT OF THE GULF ACROSS THE CWA AND BROUGHT PLENTIFUL
RAIN TO THE AREA. TODAY HAS BEEN LIKELY THE MOST SUBSTANTIAL FROM A
COVERAGE AND QPF PERSPECTIVE. UPWARDS OF 2 INCHES HAS FALLEN OVER
MANY LOCATIONS WEST OF INTERSTATE 55. FOR THE SHORT TERM RAIN
EXPECTATIONS...THE HRRR ONCE AGAIN HAS DONE AN EXCELLENT JOB ON THE
TIMING AND MOVEMENT OF RAIN. IT SUGGESTS THAT THE WEAKENING TREND
THAT CAN BE SEEN ON RADAR WILL CONTINUE WITH MUCH OF THE CURRENT
ACTIVITY DISSIPATED BEFORE 00Z AND SEE NO REASON THIS SOLUTION WONT
OCCUR. SOME RESIDUAL SHOWERS MAY LINGER INTO THE EVENING HOURS BUT
GENERALLY DRY THROUGH MUCH OF THE NIGHT.
AN UPPER LEVEL TROUGH IS IN THE PROCESS OF SWINGING ACROSS THE UPPER
MISSISSIPPI VALLEY AND WILL CONTINUE TO DO SO BEFORE MOVING
NORTHEAST OVER THE GREAT LAKES THROUGH THURSDAY. A COLD FRONT
ASSOCIATED WITH THIS TROUGH IS CURRENTLY MOVING SOUTHEAST ACROSS
NORTH TEXAS AND NWRN ARKANSAS. THE BOUNDARY SHOULD BE MOVING SEWD
ACROSS NORTHERN LOUISIANA EARLY THURSDAY MORNING. IT DOES APPEAR
THAT THE FRONT WILL STALL SOMEWHERE BETWEEN CENTRAL LA TO OVER
SOUTHEAST LA. ABUNDANT MOISTURE WHICH IS ALREADY IN PLACE IN
COMBINATION WITH CONVERGENCE ALONG THE FRONT WILL BE CONDUCIVE FOR
ANOTHER ROUND OF NUMEROUS SHOWERS AND STORMS THURSDAY. SO HAVE
INCREASED POPS TO 60 TO 80 PERCENT OVER THE CWA. MAY HAVE SLIGHTLY
LESS COVERAGE ON FRIDAY AS THE FRONT DISSOLVES BUT IN THE GRAND
SCHEME OF THINGS...WILL STILL BE QUITE A BIT OF SHOWERS AND STORMS
DEVELOPING.
MEFFER
&&
.AVIATION... A BROAD SHIELD OF LIGHT TO MODERATE RAIN WILL CONTINUE
TO BRING LOW CEILINGS BETWEEN 1000 AND 2500 FEET AND REDUCED
VISIBILITIES AS LOW AS 3 MILES TO KBTR...KMCB...KHDC THROUGH AROUND
21Z. CONDITIONS SHOULD START TO IMPROVE BACK INTO VFR RANGE AFTER
21Z AS THE PRECIPITATION SHIELD DISSIPATES. ON THE LEADING EDGE OF
THE AREA OF RAIN...INCREASED CONVECTIVE INSTABILITY REMAINS IN
PLACE...AND KEEP VCTS WORDING IN FOR THE REMAINDER OF THE TERMINALS
THROUGH 00Z. EXPECT TO SEE A MIX OF SCATTERED TO BROKEN CEILINGS
RANGING FROM 1500 TO 3000 FEET THROUGH THE AFTERNOON HOURS AT THE
REMAINING TERMINALS. VFR CONDITIONS WILL BE FOUND AT ALL TERMINALS
AFTER 00Z...BUT ANOTHER ELEVATED INVERSION SHOULD ALLOW FOR MVFR
CEILINGS AROUND 1500 TO 2500 TO REDEVELOP AROUND 10-11Z TOMORROW
MORNING AND PERSIST THROUGH THE REMAINDER OF THE MORNING HOURS. AT
KMCB...THE INVERSION WILL BE STRONGER AND RESULT IN SOME IFR AND
POSSIBLY LIFR CEILINGS OF 200 TO 300 FEET AND VISIBILITIES DOWN TO 2
MILES OR LESS AT TIMES FROM 10Z THROUGH AROUND 14Z. 32
&&
.MARINE... HAVE MADE SOME SHORT TERM ADJUSTMENTS TO THE WINDS AND
SEAS OVER LAKE PONTCHARTRAIN. LOCALIZED NW WINDS HAVE INCREASED TO A
GOOD 15 KNOTS AND LIKELY 3-4 FOOT SEAS OVER THE LAST FEW HOURS FROM
SWATH OF RAIN MOVING THROUGH. THINKING IS THAT THESE WINDS MAY
MAINTAIN FOR A COUPLE MORE HOURS BEFORE TRENDING BACK DOWN TO 10
KNOTS THIS EVENING.
MAIN ISSUE FOR MARINERS THROUGH AT LEAST FRIDAY WILL BE THE
DEVELOPMENT OF SCATTERED TO NUMEROUS THUNDERSTORMS...WITH THE
POTENTIAL FOR WINDS GUSTING ABOVE 30 KNOTS. OUTSIDE OF THE
THUNDERSTORM THREAT...GENERAL ONSHORE FLOW FROM THE SOUTH WILL
CONTINUE THROUGH THE END OF THE WORK WEEK. SHOULD BE ENOUGH OF A
GRADIENT TODAY TO PRODUCE 10-15 KNOT WINDS OVER THE OPEN WATERS
BEFORE RELAXING BELOW 10 KNOTS IN MOST AREAS FOR THURSDAY THROUGH
SATURDAY. DO NOT SEE A CLEAN FRONTAL PASSAGE ANY TIME SOON...BUT AS
EAST COAST TROF DEEPENS OVER THE WEEKEND...LIGHT OFFSHORE FLOW
SHOULD DEVELOP ON SUNDAY. 35
&&
.DECISION SUPPORT...
DSS CODE....GREEN.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...NONE.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY
ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT
TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 74 89 72 90 / 30 70 20 60
BTR 74 90 74 90 / 30 60 20 60
ASD 76 90 76 90 / 30 70 20 70
MSY 78 88 78 90 / 30 80 20 70
GPT 80 89 78 88 / 30 60 20 50
PQL 78 90 76 89 / 30 60 20 50
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
402 PM CDT WED AUG 19 2015
.SHORT TERM...(This Evening through Friday Night)
Issued at 400 PM CDT WED AUG 19 2015
Can`t beat this weather...October in mid August. Better enjoy it
while it lasts.
Deep upper trough extending from MN through eastern KS into OK will
continue tracking east tonight. Water vapor imagery shows a weak
vorticity max dropping down the back side of the trough across
western IA. Widely scattered instability showers have popped as a
result. HRRR trend supports low-end slight chance PoPs over northern
MO until about sunset. Most likely only sprinkles. Otherwise,
heating based stratocu cloud cover from NE into the CWA should
dissipate with loss of daytime heating and leave skies cloud free by
midnight. Could be flirting with record lows tomorrow morning. MCI
record min is 53 and STJ is 48.
Temperatures will rebound, but remain below average on Thursday,
before returning closer to seasonal on Friday. Warming will be the
result of the cooler/drier air being pulled away as the upper trough
moves east vs return flow from a retreating surface high. But even
the warm-up will be pleasant by summer standards as dewpoints will
remain in the 50s on Thursday and only increase into the lower 60s
on Saturday. Sure beats the upper 60s to lower 70s which occur so
often this time of year.
Will leave the forecast rain-free through Friday except for a token
slight chance PoP over far northwest MO late Thursday night.
Rain chances begin to ramp up late Friday night into Saturday
morning as stronger isentropic ascent tied to increasing low-level
moisture and development of the nocturnal low-level jet.
.LONG TERM...(Saturday through Wednesday)
Issued at 400 PM CDT WED AUG 19 2015
The GFS, European, and Canadian models are all in good agreement
that this weekend will see a pattern very similar to the pattern
that moved through the area the past couple days. The models depict
an upper level trough will develop and slide east over the northern
states through the weekend. An associated cold front will advance
across the Central Plains ahead of the trough. The models show the
best chance for storms will be Saturday night into Sunday as the
upper level trough moves over the Dakotas and the cold front moves
through the forecast area. Initially, convection will occur across
MN and IA earlier Saturday evening before spreading further south
into the forecast area as the cold front interacts with increasing
moisture ahead of and along the front. Severe potential would be
limited if showers or cloud cover linger throughout the day on
Saturday as these could restrict surface heating and convection
later in the evening. Just like today, showers could linger on
Sunday morning after the passage of the cold front. Also,
temperatures will be lower than normal for August on Sunday into
Monday, and dry conditions will prevail after the lingering showers
dissipate on Sunday. Temperatures gradually increase throughout the
early part of the work week as upper level high pressure slowly
builds over the Plains.
&&
.AVIATION...(For the 18Z TAFS through 18Z Thursday Afternoon)
Issued at 1242 PM CDT WED AUG 19 2015
A few light showers/sprinkles possible over parts of west
central/central MO this afternoon as well as north central and
northeast MO. Otherwise, VFR conditions expected except at KSTJ where
local effects due to temperature spread between river water and air
should result in generation of steam fog. Could see brief periods of
LIFR visibilities/ceilings during the pre-dawn hours.
&&
.CLIMATE...
Issued at 400 PM CDT WED AUG 19 2015
Record low temperature/date for August 19th...
Kansas City (MCI) 53/1950
St. Joseph (STJ) 48/1981
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...MJ
LONG TERM...HEC
AVIATION...MJ CLIMATE...MJ
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1216 PM CDT WED AUG 19 2015
.UPDATE:
ISSUED AT 829 AM CDT WED AUG 19 2015
NORTHWARD EXPANSION OF PRECIPITATION SHIELD HAS NOT MATERIALIZED
THIS MORNING AS PREVIOUSLY FORECAST. HAVE REMOVED THUNDER AS
CONVECTION IS NOW LIMITED TO ARKANSAS AND ITS THAT SOUTHWARD PUSH
ON THE LEADING EDGE THAT IS LIKELY RESPONSIBLE FOR THE DRIER
CONDITIONS ACROSS OUR AREA. STILL EXPECT THAT WE WILL SEE ISOLATED
TO SCATTERED SHOWERS DEVELOP THIS AFTERNOON AS THE SHORTWAVE MOVES
ACROSS THE AREA...BUT WIDESPREAD PRECIPITATION SHOULD BE LIMITED
TO SOUTHERN MISSOURI AND ILLINOIS.
CVKING
&&
.SHORT TERM: (THROUGH TONIGHT)
ISSUED AT 306 AM CDT WED AUG 19 2015
A STOUT COLD FRONT WAS SWEEPING THROUGH THE REGION EARLY THIS
MORNING. AT 08Z, THE FRONT STRETCHED FROM ITS PARENT CYCLONE OVER
SRN MN SEWD THROUGH ERN IA, THEN CURVED BACK SWWD THROUGH MO AND
INTO SERN KS AND NRN OK. WATER VAPOR IMAGERY AND RAP PV ANALYSES
DEPICT A SECONDARY VORT MAX DIVING INTO THE BASE OF THE TROUGH,
WHICH IS CONSISTENT WITH MODEL GUIDANCE. LARGE SCALE ASCENT AHEAD
OF THIS FEATURE WILL SUPPORT PERIODS OF SH/TS TODAY INTO TONIGHT.
PRECIPITATION SHOULD TAPER OFF TONIGHT IN THE WAKE OF THE
AFOREMENTIONED VORT MAX.
WED NIGHT/EARLY THU MORNING LOWS IN THE 50S WILL BE AROUND 10
DEGREES BELOW AVERAGE.
KANOFSKY
.LONG TERM: (THURSDAY THROUGH TUESDAY)
ISSUED AT 306 AM CDT WED AUG 19 2015
SURFACE HIGH PRESSURE BUILDS INTO THE SOUTHERN PLAINS ON THU AND
GRADUALLY SHIFTS EWD WITH TIME. THIS WILL KEEP COOLER/DRIER
CONDITIONS AND WESTERLY WINDS IN PLACE ACROSS MOST OF THE CWA ON
THU/FRI UNTIL THE SURFACE HIGH HAS SHIFTED FAR ENOUGH EAST FOR
WINDS TO TURN SLY AROUND ITS BACK SIDE. RETURN FLOW SETS UP
FARTHER WEST ACROSS THE PLAINS ON THU NIGHT/FRI AHEAD OF THE NEXT
LOW PRESSURE SYSTEM WHICH WILL BE CROSSING FROM THE PACIFIC NW
INTO THE PLAINS OVER THE WEEKEND. THIS SYSTEM WILL BRING THE NEXT
CHANCE FOR SH/TS TO THE LSX CWA OVER THE WEEKEND. ANOTHER STOUT
COLD FRONT IS EXPECTED TO MOVE ACROSS THE CWA ON SUN AND THEN
SETTLE SOUTH OF THE CWA EARLY NEXT WEEK. TEMPERATURES WILL DIP
BELOW AVERAGE AGAIN IN THE WAKE OF THIS FRONT.
KANOFSKY
&&
.AVIATION: (FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1215 PM CDT WED AUG 19 2015
EXPECT VFR CONDITIONS WITH ISOLATED TO SCATTERED SHOWERS THIS
AFTERNOON AS THE UPPER LEVEL TROF SWINGS ACROSS THE AREA. CLEARING
SKIES TONIGHT WITH WEST/NORTHWEST WIND CONTINUING.
SPECIFICS FOR KSTL:
EXPECT VFR CONDITIONS WITH A FEW SHOWERS THIS AFTERNOON.
CVKING
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
251 PM EDT WED AUG 19 2015
.SYNOPSIS...
UNSETTLED WEATHER WILL CONTINUE THROUGH THURSDAY. A WEAK COLD
FRONT WILL MOVE ACROSS THE AREA FRIDAY. LESS COVERAGE OF SHOWERS
AND THUNDERSTORMS CAN BE EXPECTED FRIDAY THROUGH EARLY NEXT WEEK
WITH TYPICAL LATE SUMMERTIME TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 300 PM WEDNESDAY...SCATTERED CONVECTION CONTINUES ACROSS MUCH OF
THE FORECAST AREA AND WILL CONTINUE THROUGH THE EVENING. WITH LARGE
SCALE FORCING MAINLY ABSENT THE BEST FOCUS FOR CONVECTION IS ALONG
THE OUTFLOW BOUNDARIES. SEVERAL AREAS ARE SEEING VERY HEAVY RAIN
WITH 1 TO 2 INCHES AN HOUR. THIS IS BEING HELPED BY A VERY
MOIST ATMOSPHERE WITH PRECIPITABLE WATER VALUES BETWEEN 2 AND 2.25
INCHES. THE 17 UTC RUN OF THE HRRR IS ECHOING THE 13 AND 16 UTC RUNS
OF THE HRRR WITH THE DIURNAL CONVECTION CONTINUING OVER MUCH OF THE
FORECAST AREA THROUGH 22 UTC THEN SLOWLY DISSIPATING BY SUNSET.
MAXIMUM TEMPERATURES ARE RUNNING IN THE MID TO UPPER 80S AND ARE
PEAKING FOR THE DAY. OVERNIGHT TEMPERATURES ARE EXPECTED TO DROP
INTO THE MIDDLE 70S INLAND AND THE UPPER 70S AT THE COAST.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...A MID LEVEL CYCLONE WILL MOVE ACROSS THE GREAT
LAKES WITH A BROAD ZONAL FLOW PUSHING A COLD FRONT ACROSS THE
AREA EARLY FRIDAY. BY THE END OF THE PERIOD MID LEVEL HIGH
PRESSURE BUILDS BACK IN FROM THE SOUTH WITH ANY APPRECIABLE
AFFECTS FROM THE FRONT BASICALLY GONE. FOR THURSDAY...WEAK SURFACE
TROUGHING WILL STILL RESIDE ACROSS THE AREA AND GOOD CHANCE POPS
REMAIN IN THE FORECAST. POPS DECREASE SOMEWHAT FOR FRIDAY AS THE
WEAK FRONT HAS A SIGNIFICANT SUBSIDENCE INVERSION IN THE 700-850MB
LAYER WHICH WILL MAKE CONVECTIVE DEVELOPMENT MORE CHALLENGING THAN
PREVIOUS DAYS. THERE REMAINS A VERY MOIST PROFILE HOWEVER AND
LOWER CHANCE POPS SHOULD BE A GOOD COMPROMISE. TEMPERATURES CHANGE
LITTLE THROUGH THE PERIOD WITH HIGHS IN THE 90S AND LOWS IN THE
70S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 AM WEDNESDAY...COLD FRONT PUSHING OFFSHORE FIRST THING
SATURDAY WILL LEAVE CLEARING SKY CONDITIONS AND IMPROVING WEATHER
FOR THE WKND. WHILE THIS FASTER FROPA REPRESENTS A CHANGE IN THE
FORECAST...GUIDANCE IS IN GOOD AGREEMENT ATTM WITH A STRONG MID-
LEVEL PUSH...AND THE WKND IS LOOKING TO BE QUITE NICE LOCALLY NOW.
WEAK COOL ADVECTION BUT STRONG DRY ADVECTION WILL ERODE CLOUDS
SATURDAY...AND THEN LEAVE AMPLE SUNSHINE LATE SATURDAY AND ON
SUNDAY...AS PWATS DROP TO AROUND THE FIRST QUARTILE MOVING-AVERAGE
FOR LATE AUGUST. TEMPS THIS WKND WILL BE AROUND OR SLIGHTLY BELOW
CLIMO WITH N/NE WINDS...BUT OVERALL A PLEASANT WKND APPEARS TO BE
IN STORE. RETURN FLOW BEGINS TO REDEVELOP MONDAY WITH TEMPS
WARMING BACK TO SEASONABLE LEVELS OR SLIGHTLY ABOVE...BUT THIS
WILL BE ACCOMPANIED BY INCREASING PRECIP CHANCES AS WELL. GFS
DRIVES A POTENT SHORTWAVE OVERHEAD LATE MONDAY INTO TUESDAY...A
PIECE OF THE LONGER TROUGH TRAVERSING THE NORTHEAST...WHILE THE
ECMWF SHOWS NO SUCH FEATURE. FOR NOW WILL RAMP POP BACK UP TO
CLIMO VALUES FOR EARLY NEXT WEEK...MAINTAINING THE INHERITED
FORECAST
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
AS OF 18Z...EXPECT VFR FOR THE REST OF THE VALID TAF PERIOD WITH
ISOLATED TO SCATTERED SHRA/TSRA THIS AFTERNOON AND TONIGHT.
POTENTIAL FOR PATCHY MARGINAL MVFR FOG OVERNIGHT.
LATEST RADAR DEPICTS ISOLATED TO SCATTERED SHRA/TSRA DEVELOPING
ACROSS THE AREA. WHILE COULD SEE BRIEF PERIODS OF MVFR IN ANY HEAVY
DOWNPOURS...OVERALL EXPECT VFR THROUGH TONIGHT. SOUTHWEST WINDS WILL
INCREASE TO AOB 12 KTS THIS AFTERNOON...BECOMING LIGHT AND VARIABLE
TONIGHT. COULD SEE PATCHY AREAS OF MARGINAL MVFR FOG LATE
OVERNIGHT...THUS HAVE INTRODUCED TEMPO GROUP. AFTER DAYBREAK...VFR
WILL PREVAIL WITH SOUTHWEST WINDS.
EXTENDED OUTLOOK...SCATTERED CONVECTION IS EXPECTED THROUGH THE
PERIOD...MOST ACTIVE THURSDAY WITH BRIEF IFR CONDITIONS POSSIBLE.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM WEDNESDAY...SOUTH TO SOUTHWEST WINDS OF 10 TO 15 KNOTS
ARE BLOWING OVER THE WATERS WITH SEAS CONTINUING TO RUN BETWEEN 2
AND 3 FEET. THE FRYING PAN BUOY CONTINUES TO SHOWS A ESE SWELL OF
1.3 FEET WITH THE 2.3 FT WIND WAVE AND THESE CONDITIONS ARE
EXPECTED TO REMAIN THE SAME THROUGHOUT THE OVERNIGHT WITH THE ONLY
HAZARD WILL BE AN ISOLATED
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...THE PIEDMONT TROUGH WILL BECOME MORE A LITTLE
BETTER DEFINED THURSDAY AND WIND FIELDS WILL SHOULD RESPOND WITH A
SOUTHWEST FLOW OF 10-15 KNOTS...MOSTLY IN THE LOWER END OF THE
RANGE. A WEAK FRONT WILL PUSH ACROSS THE WATERS EARLY FRIDAY WITH
THE FRONT AND THE LAND BREEZE PROVIDING A BRIEF OFFSHORE FLOW. BY
LATER IN THE DAY LIGHT AND VARIABLE WINDS DEVELOP UNDER A WEAK
PRESSURE PATTERN. AS FOR SEAS...GENERALLY 2-3 FEET THROUGH THE
PERIOD.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 300 AM WEDNESDAY...COLD FRONT WILL BE SOUTH OF THE WATERS
SATURDAY MORNING...LEAVING NE WINDS IN ITS WAKE. THIS WIND
DIRECTION WILL PERSIST MUCH OF THE PERIOD...BUT A WEAKENING OF THE
FRONT WILL ALLOW RETURN FLOW AND SOUTHERLY WINDS TO REDEVELOP
LATE. SPEEDS FROM THE NE WILL BE 10-15 KTS...EASING AS THE WINDS
SHIFT AT THE END OF THE PERIOD. WAVE HEIGHTS WILL BE PRIMARILY
WIND-WAVE DRIVEN...BUT OF LOW AMPLITUDE AROUND 1-3 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...DRH
SHORT TERM...SHK
LONG TERM...JDW
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
152 PM EDT WED AUG 19 2015
.SYNOPSIS...
UNSETTLED WEATHER WILL CONTINUE THROUGH MID WEEK AS TROPICAL
MOISTURE STREAMS INTO THE AREA AHEAD OF AN APPROACHING COLD
FRONT. THE FRONT WILL REACH THE COASTAL CAROLINAS BY FRIDAY AND
OFFSHORE OVER THE WEEKEND. ANOTHER COLD FRONT MAY APPROACH ON
TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM WEDNESDAY...SCATTERED CONVECTION HAS DEVELOPED
ACROSS MUCH OF THE THE AREA AND IS EXPECTED TO CONTINUE TO DEVELOP
ALONG OUTFLOWS AS LARGE SCALE FORCING IS NOT A MAJOR INFLUENCE
TODAY. WITH THE PRECIPITABLE WATERS RUNNING OVER 2 INCHES HEAVY
DOWNPOURS CAN BE EXPECTED AND FREQUENT LIGHTNING. THE 16 UTC RUN
OF THE HRRR IS ECHOING THE 13 UTC RUN WITH THE DIURNAL CONVECTION
CONTINUING OVER MUCH OF THE FORECAST AREA THROUGH 22 UTC THEN
DISSIPATING.
MAXIMUM TEMPERATURES ARE RUNNING IN THE MID TO UPPER 80S AND ARE
PEAKING FOR THE DAY. OVERNIGHT TEMPERATURES ARE EXPECTED TO DROP
INTO THE MIDDLE 70S INLAND AND THE UPPER 70S AT THE COAST.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...BIGGEST QUESTION MARK FOR THE SHORT TERM
WILL BE HOW FAR SOUTH DOES A COLD FRONT PROGRESS ACROSS THE
CAROLINAS.
AHEAD OF THIS FEATURE...SHARP RIDGING ALOFT COMBINED WITH
RETURN FLOW WILL PUMP HEAT AND HUMIDITY INTO THE REGION...AND HIGHS
WILL RISE INTO THE 90S EVERYWHERE AWAY FROM THE IMMEDIATE COAST.
THIS IS SEVERAL DEGREES ABOVE NORMAL FOR MID-AUGUST...AND THE HIGH
DEWPOINTS WILL MAKE HEAT INDEX VALUES RISE TO 100 OR SLIGHTLY
GREATER. AMPLE INSTABILITY WITHIN THIS AIRMASS WILL BE TAPPED BY A
SHORTWAVE PROGGED TO MOVE OVERHEAD IN THE AFTN...AND SCATTERED TO
POTENTIALLY WIDESPREAD CONVECTION IS POSSIBLE. MOS P-NUMBERS HAVE
INCREASED TO LIKELY ACROSS THE AREA...BUT THEY HAVE BEEN OVERDONE
RECENTLY. WILL BUMP POP TO HIGH-CHC LOCALLY WITH PERIODS OF HEAVY
RAINFALL THE BIGGEST THREAT. LOWS THURSDAY NIGHT WILL BE QUITE
WARM...FALLING INTO THE MID 70S...WITH SOME UPPER 70S POSSIBLE ALONG
THE COAST.
FRIDAY WILL BE THE TRANSITION DAY AS THE COLD FRONT TO THE WEST
MOVES ACROSS THE AREA. ALL GUIDANCE HAS INCREASED THE SPEED OF THIS
FEATURE...LIKELY DUE TO A STRONGER PARENT TROUGH AND VORT LOBE..WITH
LESS MID-LEVEL PARALLEL FLOW. WPC SUPPORTS THIS FASTER GUIDANCE AS
WELL...SO WILL SHOW THE FRONT MOVING OFFSHORE BY LATE FRIDAY.
CONVECTION WILL ACCOMPANY THIS BOUNDARY AS IT SWINGS S/SE FRIDAY
INTO FRIDAY NIGHT...BUT DRYING DOES OCCUR IN EARNEST LATE SO BEST
PRECIP CHANCES WILL BE THE FIRST HALF OF FRIDAY. TEMPS WILL REMAIN
ABOVE NORMAL THANKS TO WARM ADVECTION AHEAD OF THE BOUNDARY...BUT
WILL BE A FEW DEGREES COOLER THAN THURSDAY. LOWS FRIDAY NIGHT WILL
REMAIN ABOVE CLIMO AS WEAK COLD ADVECTION LAGS...WITH MINS DROPPING
INTO THE 72-75 DEGREE RANGE...WARMEST AT THE COAST.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 300 AM WEDNESDAY...COLD FRONT PUSHING OFFSHORE FIRST THING
SATURDAY WILL LEAVE CLEARING SKY CONDITIONS AND IMPROVING WEATHER
FOR THE WKND. WHILE THIS FASTER FROPA REPRESENTS A CHANGE IN THE
FORECAST...GUIDANCE IS IN GOOD AGREEMENT ATTM WITH A STRONG MID-
LEVEL PUSH...AND THE WKND IS LOOKING TO BE QUITE NICE LOCALLY NOW.
WEAK COOL ADVECTION BUT STRONG DRY ADVECTION WILL ERODE CLOUDS
SATURDAY...AND THEN LEAVE AMPLE SUNSHINE LATE SATURDAY AND ON
SUNDAY...AS PWATS DROP TO AROUND THE FIRST QUARTILE MOVING-AVERAGE
FOR LATE AUGUST. TEMPS THIS WKND WILL BE AROUND OR SLIGHTLY BELOW
CLIMO WITH N/NE WINDS...BUT OVERALL A PLEASANT WKND APPEARS TO BE IN
STORE. RETURN FLOW BEGINS TO REDEVELOP MONDAY WITH TEMPS WARMING
BACK TO SEASONABLE LEVELS OR SLIGHTLY ABOVE...BUT THIS WILL BE
ACCOMPANIED BY INCREASING PRECIP CHANCES AS WELL. GFS DRIVES A
POTENT SHORTWAVE OVERHEAD LATE MONDAY INTO TUESDAY...A PIECE OF THE
LONGER TROUGH TRAVERSING THE NORTHEAST...WHILE THE ECMWF SHOWS NO
SUCH FEATURE. FOR NOW WILL RAMP POP BACK UP TO CLIMO VALUES FOR
EARLY NEXT WEEK...MAINTAINING THE INHERITED FORECAST
&&
.AVIATION /18Z WEDNESDAY THROUGH TUESDAY/...
AS OF 18Z...EXPECT VFR FOR THE REST OF THE VALID TAF PERIOD WITH
ISOLATED TO SCATTERED SHRA/TSRA THIS AFTERNOON AND TONIGHT.
POTENTIAL FOR PATCHY MARGINAL MVFR FOG OVERNIGHT.
LATEST RADAR DEPICTS ISOLATED TO SCATTERED SHRA/TSRA DEVELOPING
ACROSS THE AREA. WHILE COULD SEE BRIEF PERIODS OF MVFR IN ANY HEAVY
DOWNPOURS...OVERALL EXPECT VFR THROUGH TONIGHT. SOUTHWEST WINDS WILL
INCREASE TO AOB 12 KTS THIS AFTERNOON...BECOMING LIGHT AND VARIABLE
TONIGHT. COULD SEE PATCHY AREAS OF MARGINAL MVFR FOG LATE
OVERNIGHT...THUS HAVE INTRODUCED TEMPO GROUP. AFTER DAYBREAK...VFR
WILL PREVAIL WITH SOUTHWEST WINDS.
EXTENDED OUTLOOK...SCATTERED CONVECTION IS EXPECTED THROUGH THE
PERIOD...MOST ACTIVE THURSDAY WITH BRIEF IFR CONDITIONS POSSIBLE.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM WEDNESDAY...LIGHT SOUTHWEST WINDS OVER THE WATERS
THIS MORNING WITH SEAS RUNNING 2 TO 3 FEET WITH A 1.3 EAST
SOUTHEAST SWELL. SCATTERED THUNDERSTORMS ARE POSSIBLE THIS
AFTERNOON AS A FEW STORMS THAT DEVELOP ALONG THE COAST COULD MOVE
OUT OVER THE WATER. THE MAIN THREAT APPEARS TO BE LIGHTNING.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...PRE- FRONTAL REGIME THURSDAY WILL LEAVE
SW WINDS OF 10-15 KTS ACROSS THE WATERS. THIS WILL BE SHORT-LIVED
HOWEVER AS A COLD FRONT RACES TOWARDS THE WATERS DURING FRIDAY.
THIS FRONT WILL CROSS INTO THE WATERS AND THEN DROP SOUTH BY
FRIDAY NIGHT...LEAVING WINDS SHIFTING FROM WEST...ALL THE WAY
AROUND TO THE EAST...AND THEN FINALLY TAKING ON A PREDOMINANT NE
DIRECTION LATE IN THE PERIOD. SPEEDS THROUGH FRIDAY WILL BE LIGHT
REGARDLESS OF DIRECTION...LESS THAN 10 KTS. SEAS THURSDAY WILL BE
2-3 FT WITH A SE SWELL AND SW WIND CHOP COMPRISING THE SPECTRUM.
WAVE HEIGHTS FRIDAY WILL DROP TO JUST 1-2 FT ON THE LIGHTER
WINDS...WITH A VARIETY OF WAVE GROUPS PRESENT.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 AM WEDNESDAY...COLD FRONT WILL BE SOUTH OF THE WATERS
SATURDAY MORNING...LEAVING NE WINDS IN ITS WAKE. THIS WIND DIRECTION
WILL PERSIST MUCH OF THE PERIOD...BUT A WEAKENING OF THE FRONT WILL
ALLOW RETURN FLOW AND SOUTHERLY WINDS TO REDEVELOP LATE. SPEEDS FROM
THE NE WILL BE 10-15 KTS...EASING AS THE WINDS SHIFT AT THE END OF
THE PERIOD. WAVE HEIGHTS WILL BE PRIMARILY WIND-WAVE DRIVEN...BUT OF
LOW AMPLITUDE AROUND 1-3 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DRH
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS NORMAN OK
100 PM CDT WED AUG 19 2015
.DISCUSSION...
THE 18Z AVIATION DISCUSSION IS BELOW.
&&
.AVIATION...
ONGOING SHOWERS AND THUNDERSTORMS WILL CONTINUE TO AFFECT
KOUN/KLAW/KSPS THIS AFTERNOON. EXPECT PRECIPITATION TO END FROM
NORTH TO SOUTH...WITH PRECIPITATION ENDING AT KSPS BY 23Z.
PERIODS OF MVFR CONDITIONS CAN BE EXPECTED AT THESE SITES.
OTHERWISE...GUSTY NORTHERLY WINDS SHOULD SUBSIDE TO LIGHT AND
VARIABLE WITH CLEARING SKIES OVERNIGHT.
MAHALE
&&
.PREV DISCUSSION... /ISSUED 1026 AM CDT WED AUG 19 2015/
UPDATE...
ADJUSTED PRECIP/WX THROUGH THE AFTERNOON... MINOR ADJUSTMENTS TO
TEMPS...
DISCUSSION...
SHOWERS AND THUNDERSTORMS CONTINUE TO DECREASE IN COVERAGE ACROSS
S/SWRN OK AND WRN N TX THIS MORNING. THIS TREND LOOKS TO CONTINUE
THROUGH THE AFTN AS THE H700 SHORT WAVE PUSHES EAST... DECREASING
MID-LEVEL SUPPORT. BUFR SOUNDINGS SUGGEST DECREASING SHEAR AND
INSTABILITY ENVIRONMENT WILL CONTINUE TO EVOLVE ACROSS SRN OK/WRN
N TX THROUGH THE EARLY AFTN. HRRR HAS SHOWN RELATIVELY DECENT
CONTINUITY THIS AM... WITH SHOWERS AND ISOLATED THUNDER LINGERING
THROUGH THE AFTN AND INTO THE EVENING ACROSS SOUTH CENTRAL OK.
ADJUSTED HIGH TEMPS SLIGHTLY FOR THIS AFTN... BRINGING OKC TO 67.
THROUGH 10AM... ALREADY REACHED 65... AND BEGINNING TO SEE SOME
BREAKS IN THE CLOUDS ACROSS NWRN OK. IF A FEW BREAKS DEVELOP OVER
CENTRAL OK THIS AFTN... TEMPS COULD EASILY MOVE INTO THE UPPER
60S FOR HIGHS... SO ENJOY.
JTK
PREV DISCUSSION... /ISSUED 628 AM CDT WED AUG 19 2015/
DISCUSSION...
THE 12Z AVIATION DISCUSSION FOLLOWS....
AVIATION...
WIDESPREAD RA AND TSRA WILL CONTINUE ALONG...AND IN THE GENERAL
VICINITY OF...A STRONG COLD FRONT ACROSS OK AND N TX. SCT SHRA
WILL ALSO OCCUR WELL INTO THE COOLER AIR OVER N OK UNTIL HIGH
PRESSURE FILLS IN THIS AFTERNOON/EVENING. SCATTERED AREAS OF LOW
CLOUDS AND TEMPORARY LOW VISIBILITIES WILL OCCUR NEAR THE NUMEROUS
TSRA. AS HIGH PRESSURE CONTINUES TO BUILD INTO OK/N TX THIS
EVENING AND OVERNIGHT...THE RAIN WILL BECOME LIMITED TO THE FAR
S...AND SKIES WILL BEGIN TO CLEAR IN THE N. BY SUNRISE...EXPECT
VFR CONDITIONS AND LIGHT WINDS. AREAS THAT CLEAR BEFORE SUNRISE
MAY DEVELOP GROUND FOG.
CMS
PREV DISCUSSION... /ISSUED 409 AM CDT WED AUG 19 2015/
DISCUSSION...
AN UNSEASONABLY STRONG COLD FRONT EXTENDED FROM EAST-CENTRAL TO
SOUTHWEST OKLAHOMA EARLY THIS MORNING...WITH AN OUTFLOW BOUNDARY
EXTENDING FARTHER TO THE SOUTH...ROUGHLY FROM SHAWNEE TO WICHITA
FALLS. MUCH COOLER AND DRIER AIR WAS OVER KANSAS...AND WILL SHIFT
SOUTH TODAY AND TONIGHT.
THE COMBINED EFFECTS OF THE COOLER/DRIER AIR...AND RAIN FALLING
THROUGH IT...WILL RESULT IN TEMPERATURES THAT ARE VERY COOL FOR
THIS TIME OF YEAR. RECORD LOW MAXIMUM TEMPERATURES ARE LIKELY
ACROSS MUCH OF THE REGION TODAY...AND RECORD LOW MINIMUM
TEMPERATURES ARE LIKELY TOMORROW MORNING. THE BALANCE OF THE
VARIOUS ELEMENTS AFFECTING TEMPERATURE TODAY IS A MAJOR
CHALLENGE...AND TEMPERATURE FORECASTS TODAY SHOULD BE CONSIDERED
AS APPROXIMATE...ESPECIALLY HOURLY TEMPERATURES.
RAIN CHANCES ARE ALSO PROBLEMATIC TODAY...AS THE EVOLUTION OF THE
CURRENT MCS IS UNCLEAR. HAVE GENERALLY FORECAST POPS ABOVE THE
OVERALL MODEL GUIDANCE VALUES...ON THE ASSUMPTION THAT THE MCS
WILL HOLD TOGETHER AT LEAST THROUGH MID-MORNING.
AFTER A DAY OF COOL DRY WEATHER...THE WARM/HUMID AIR WILL RETURN
NORTH...BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS
FRIDAY. A SERIES OF DISTURBANCES WILL KEEP RAIN IN THE FORECAST
UNTIL EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 69 54 81 61 / 100 10 0 10
HOBART OK 70 54 84 63 / 80 10 0 20
WICHITA FALLS TX 74 57 85 66 / 100 20 0 20
GAGE OK 75 53 82 62 / 30 10 0 10
PONCA CITY OK 73 53 82 61 / 60 10 0 10
DURANT OK 82 59 82 65 / 80 50 10 20
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
04/67/10
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
519 PM EDT WED AUG 19 2015
.SYNOPSIS...
A WEAK FRONT WILL APPROACH THE AREA ON THURSDAY...PRECEDED BY
SHOWERS AND THUNDERSTORMS. SOME DRYING IS EXPECTED OVER THE WEEKEND.
ANOTHER WEAK FRONT APPROACHES OUR AREA EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 510PM WED...UPDATED FORECAST TO CONCENTRATE PRECIPITATION TO
EASTERN PARTS OF THE CWA PER RADAR TRENDS AND HRRR GUIDANCE. RADAR
HAS HAD HEAVIEST COVERAGE OF THUNDERSTORMS MOVING EASTWARD WITH SOME
RESIDUAL ACTIVITY ELSEWHERE. HEAVIER STORMS OVER EASTERN PARTS OF
THE CWA AGREES WITH HIGHER CAPE ANALYSIS IN THAT AREA. RAINFALL
AMOUNTS WILL CONTINUE TO BE GENEROUS...GIVEN HIGH PRECIPITABLE
WATER. SHOWERS WILL BEGIN TO TAPER AFTER 3Z THIS EVENING.
AS OF 230 PM WED...RADAR CONTINUES TO SHOW INCREASING COVERAGE AND
EXPECT NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE AREA THROUGH
THE AFTERNOON. SOME MORE STRATIFORM TYPE PRECIP WITH EMBEDDED
THUNDER MAY LINGER INTO THE EVENING HOURS OVER EASTERN AREAS. SPC
MESOANAL SHOWING CAPES IN THE 2000-3000J/KG RANGE OUTSIDE THE
MOUNTAINS. ALSO...THE DCAPE HIGHER TODAY THAN PREVIOUS DAYS NOW
HAVING INCREASED TO OVER 1000J EASTERN AREAS. HENCE...SEVERE STORM
CHANCES HIGHER THIS AFTERNOON AND WE SHOULD SEE SEVERAL PULSE SEVERE
STORMS. THE SEVERE THREAT WILL BE ALONG SIDE THE LOCALIZED HYDRO
THREAT.
IN REGARD TO THE BIG PICTURE...A VORT MAX IS FORECAST TO MOVE ACROSS
THE AREA DURING THE LATE AFTERNOON AND EVENING HOURS WHICH IS THE
PRIMARY TRIGGER OF THE NUMEROUS SHOWERS AND STORMS. NVA BEHIND THIS
FEATURE SHOULD RESULT IN A LULL IN PRECIP COVERAGE DURING THE
OVERNIGHT HOURS. MINIMUM TEMPS ARE EXPECTED TO BE ABOUT A CATEGORY
ABOVE CLIMO.
ON THURSDAY...A DEEP UPPER TROUGH SWINGING THROUGH THE GREAT LAKES
WILL PUSH A COLD FRONT SOUTHEASTWARD AND IT IS FORECAST TO REACH THE
MOUNTAINS DURING THE AFTERNOON. WITH DEEP LAYER MOISTURE STILL IN
PLACE...THERE STILL SHOULD BE DECENT COVERAGE OF SHOWERS AND
THUNDERSTORMS IN THE MOUNTAINS. HOWEVER EAST OF THE MOUNTAINS...WITH
FLOW BECOMING MORE ZONAL/DOWNSLOPE THE COVERAGE SHOULD BE SCT. MODEL
FORECAST SOUNDINGS ALSO INDICATE LESS CAPE...SO SEVERE THREAT
APPEARS ON THE LOW END. MAX TEMPS WILL BE NEAR TO CLIMO.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 200 PM EDT WEDNESDAY...THE SHORT TERM FCST PERIOD INITIALIZES
THURSDAY EVENING AMIDST AN ONGOING COLD FRONTAL INTRUSION.
THE UPPER PATTERN WILL BE HIGHLIGHTED BY A DEEP NEGATIVELY TILTED
LONGWAVE TROF EJECTING THROUGH THE GREAT LAKES WHILE BROAD RIDGING
PREVAILS OVER THE DEEP SOUTH AND EASTERN GULF. AS STATED ABOVE...A
COLD FRONT WILL BE WORKING ITS WAY INTO/THROUGH THE NC HIGH TERRAIN
BY THURSDAY EVENING WITH DEEP SOUTHWESTERLY FLOW PREVAILING OUT
AHEAD. IN RESPONSE...EXPECTING ONGOING CONVECTION IN THE WARM
SECTOR AT FCST INITIALIZATION POSSIBLY AIDED BY ENHANCED SHEARING
AND VORT ADVECTION ALOFT. SHORT TERM GUIDANCE IS NOW IN BETTER
AGREEMENT WITH REGARDS TO THE TRACK/DEPTH OF THE FRONTAL PASSAGE
WITH BOTH THE GFS/NAM ALONG WITH THE ECMWF PUSHING THE BOUNDARY
SOUTH OF THE CWFA...LIKELY WASHING OUT OVER THE LOWCOUNTRY/MIDLANDS
BY MID MORNING FRIDAY.
BROAD SFC HIGH PRESSURE IS FCST TO ADVECT IN FROM THE MIDWEST
INTO THE OHIO VALLEY JUST BEHIND THE FRONT...BEFORE SLIDING OVER
THE SOUTHERN/CENTRAL APPS LATER IN THE DAY. AS A RESULT...DRIER
NORTHERLY FLOW WILL WARRANT DECREASED PRECIPITATION POTENTIAL
AND PARTLY CLOUDY SKIES ACROSS MUCH OF WESTERN NC. DUE TO CLOSER
PROXIMITY TO ANY REMNANT FRONTAL MOISTURE...LOCATIONS ALONG AND
SOUTH OF THE I85 CORRIDOR WILL SEE SLIGHTLY HIGH PROBABILITIES AND
THUS PARTLY/MOSTLY CLOUDY SKIES. NEVERTHELESS...PROFILES ARE NOT
SUPPORTIVE OF ANY DEEP CONVECTION AT THIS TIME THEREFORE NOTHING
MORE THAN GARDEN VARIETY SHOWERS WITH PERHAPS A FEW RUMBLES OF
THUNDER ARE EXPECTED. SATURDAY IS SHAPING UP TO BE THE NICEST DAY
OF THE PERIOD WITH MODELS INDICATING FURTHER DRY AIR INTRUSION
AS THE ABOVE MENTIONED SURFACE RIDGE MOVES EAST OF THE APPS.
MOSGUIDE AND TO SOME EXTENT EVEN THE RAW NAM INDICATES DEWPOINTS
IN THE UPPER 50S ACROSS NORTHWEST NC INCREASING TO THE LOWER 60S
ALONG THE I85 CORRIDOR. THUS EXPECTING MOSTLY SUNNY TO PARTLY
CLOUDY SKIES AND TEMPERATURES A FEW DEGREES BELOW NORMAL ALLOWING
FOR A BEAUTIFUL MID/LATE AUGUST DAY. THAT SAID...NAM GUID DOES
FAVORS AT LEAST SOME CHANCE FOR LOW END DESTABILIZATION OVER THE
SOUTHWEST NC MOUNTAINS AND NORTHEAST GA...THEREFORE WILL INCLUDE
POPS TO ACCOUNT FOR SUCH WITH MAX HEATING ON SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AT 230 PM EDT WEDNESDAY...ON SUNDAY AN UPPER RIDGE WILL BE OVER THE
WESTERN USA...WITH A MEAN TROUGH OVER THE EAST. THE PATTERN
AMPLIFIES SLIGHTLY INTO TUESDAY AS A CLOSED UPPER LOW CROSSES SOUTH
CENTRAL CANADA. THE PATTERN DEAMPLIFIES SLIGHTLY BY THURSDAY AS THE
CANADIAN LOW APPROACHES THE ATLANTIC....BY WHICH TIME SOME
PROGRESSION TAKES PLACE...AND THE UPPER TROUGH REACHES THE EASTERN
SEABOARD...WHILE THE RIDGE UPSTREAM CROSSES THE PLAINS AND EXTENDS
INTO THE GULF STATES.
AT THE SURFACE...SUNDAY STARTS OUT WITH HIGH PRESSURE ALONG THE
EASTERN SEABOARD...WITH A COLD FRONT UPSTREAM FORM THE GREAT LAKES
TO THE SOUTHERN PLAINS. THIS FRONT REACHES THE SOUTHERN APPALACHIANS
ON MONDAY...MOVING TO THE COASTAL PLAIN BY TUESDAY...WHERE IT STALLS
AND REMAINS INTO WEDNESDAY. OUR AREA CAN EXPECT AN ACTIVE PATTERN
AHEAD OF AND ALONG THE FRONT...WITH A DRYING TREND IN THE
WAKE OF THE FRONT. AT THIS TIME...PRECIPITATION AMOUNTS ARE NOT
EXPECTED TO BE EXCESSIVE AS THE FRONT DOES NOT STALL UNTIL EAST OF
OUR AREA. TEMPERATURES WILL RUN NEAR NORMAL.
&&
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...LOOKS LIKE IT IS GOING TO BE ACTIVE DAY FOR CONVECTION AS
RADAR BEGINNING TO SHOW QUITE A BIT OF COVERAGE. CURRENT TRENDS
INDICATE THAT TEMPO TSRA WILL OCCUR FROM 19Z-23Z WITH PERHAPS SOME
MORE STRATIFORM TYPE PRECIP EXTENDING INTO THE EVENING HOURS AS A
VORT MAX MOVES THROUGH. IFR RESTRICTIONS CERTAINLY POSSIBLE IN THE
HEAVIER CONVECTIVE CELLS. AFTER ABOUT 03Z PRECIP SHOULD END WITH
CONDITIONS VFR. GUIDANCE NOT TOO EXCITED ABOUT EARLY MORNING
FOG/STRATUS BUT NOT CONVICNED IT WILL NOT OCCUR...SO MENTIONED SOME
LIGHT FOG WITH SCT010 CIRCA 12Z.
ELSEWHERE...FAIRLY SIMILAR CONDITIONS TO KCLT WITH TEMPO TSRA AND
POSSIBLE IFR RESTRICTIONS INTO THE EARLY EVENING HOURS. PRECIP
SHOULD END BY 03Z. EXPECT ONLY PATCHY IFR STRATUS/FOG EARLY
THURSDAY. CONFIDENCE NOT HIGH ENOUGH TO PUT INTO TAF EXCEPT AT KAVL.
OUTLOOK...A COLD FRONT WILL PUSH THROUGH THE AREA LATE THURSDAY AND
THURSDAY NIGHT. ASSOCIATED SHOWERS/THUNDERSTORSM ARE EXPECTED TO END
THURSDAY NIGHT. LINGERING LOW LEVEL MOISTURE MAY RESULT IN
RESTRICTIONS IN FOG/STRATUS EARLY FRIDAY. DRY HIGH PRESSRUE BUILDING
IN FROM THE NORTH WILL LIMIT RESTRICTIONS THROUGH THE WEEKEND.
CONFIDENCE TABLE...
21-03Z 03-09Z 09-15Z 15-18Z
KCLT HIGH 100% HIGH 85% HIGH 100% HIGH 100%
KGSP HIGH 91% HIGH 83% HIGH 100% HIGH 88%
KAVL HIGH 100% HIGH 96% HIGH 96% HIGH 97%
KHKY HIGH 100% HIGH 87% HIGH 86% HIGH 100%
KGMU MED 75% HIGH 87% HIGH 100% HIGH 87%
KAND HIGH 100% HIGH 100% HIGH 91% HIGH 81%
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
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JAT
NEAR TERM...LG/WJM
SHORT TERM...CDG
LONG TERM...JAT
AVIATION...LG
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
348 PM CDT WED AUG 19 2015
.SYNOPSIS...
THE MAIN STORY WITH THIS FORECAST PACKAGE WILL BE THE COOLER
WEATHER AND RAIN CHANCES OVER THE NEXT 12-24 HOURS. A RETURN TO
WARM CONDITIONS IS EXPECTED LATER THIS WEEK AND THROUGH THE
WEEKEND WITH LOWER CHANCES FOR PRECIPITATION.
&&
.SHORT TERM (TONIGHT THROUGH FRIDAY)...
A VERY DIFFICULT FORECAST EXISTS WITH SOME DIFFERENCES BETWEEN
BOTH HI-RES AND COARSE MODEL SOLUTIONS. AS IS OFTEN THE
CASE...NUMERICAL WEATHER PREDICTION OFTEN STRUGGLES WITH EVENTS
THAT ARE EITHER WEAKLY FORCED OR PRIMARILY DRIVEN BY MESOSCALE
PHENOMENON. IN THE CASE OF TODAY...A BULK OF THE LARGE SCALE
FORCING FOR ASCENT WAS DISPLACED WELL TO THE NORTH OF
NORTH/CENTRAL TEXAS AND THE MAIN FOCUSING MECHANISMS FOR WHAT RAIN
DID FALL THIS MORNING AND THIS AFTERNOON WERE OUTFLOW BOUNDARIES
FROM PREVIOUS CONVECTION ACROSS OK AND THE TX PANHANDLE.
MOST OF THE CONVECTION THIS AFTERNOON ON AREA RADARS APPEAR TO BE
ALONG THE FRONT WHERE SUFFICIENT LOW LEVEL CONVERGENCE IS
OCCURRING. WITH THE FRONT STARTING TO QUICKLY MOVE SOUTHWARD MOST
OF THIS ACTIVITY IS SHORT LIVED AS IT IS BEING UNDERCUT BY THE
SHALLOWER/COOLER AIR.
FOR THE REST OF THE AFTERNOON AND TONIGHT...STILL FEEL CONFIDENT
ENOUGH THAT THERE WILL BE A COUPLE OF AREAS THAT COULD SEE SOME
MEASURABLE PRECIPITATION. THE FIRST WILL BE ALONG OUR SOUTHEAST
ZONES NEAR THE SFC-925 MB FRONT LATER THIS AFTERNOON AND INTO
TONIGHT. MOST COARSE MODELS /EXCLUDING THE NAM/ SUGGEST THAT SOME
LOW LEVEL FRONTOGENESIS WILL OCCUR AND SHOULD YIELD ISOLATED TO
SCATTERED CONVECTION. THE OVERALL SEVERE POTENTIAL SEEMS
RELATIVELY LOW...BUT GIVEN THE UNSTABLE AIRMASS AHEAD OF THE
FRONT...WOULD NOT RULE OUT A STRONG DOWNBURST OR TWO. THERE MAY BE
A SMALL HAIL RISK WITH CONVECTION NEAR THE FRONT...BUT THINK THAT
CONVECTION IS BECOMING UNDERCUT TOO QUICKLY BEFORE HAIL PRODUCTION
CAN OCCUR.
THE SECOND AREA WITH A SLIGHTLY HIGHER CHANCE FOR PRECIPITATION
WILL BE ALONG AND NORTH OF THE INTERSTATE 20 CORRIDOR WHERE 850 MB
FRONTOGENETIC FORCING IS BEING ADVERTISED. PER THE TTU WRF AND
LATEST HRRR SOME AREAS OF ISOLATED TO WIDELY SCATTERED ACTIVITY IS
EXPECTED TO DEVELOP DURING THE OVERNIGHT HOURS INTO EARLY THURSDAY
MORNING. CLOSER TO SUNRISE...THIS ACTIVITY SHOULD SHIFT SOUTHWARD
AS DRIER AIR WORKS ITS WAY IN FROM THE NORTH. CURRENTLY THINK THAT
SOME SKIES ACROSS OUR IMMEDIATE RED RIVER ZONES MAY CLEAR ENOUGH
TO ALLOW FOR SOME DECENT COOLING. WITH THE CONTINUED NORTH
WINDS...THIS SHOULD ALLOW TEMPERATURES TO FALL INTO THE 60S WITH
PERHAPS EVEN A FEW UPPER 50S ALONG THE RED RIVER.
FOR THURSDAY AND THURSDAY NIGHT...THE HIGHEST RAIN CHANCES WILL
REMAIN DOWN ALONG OUR SOUTHEASTERN ZONES WHERE THE FRONT WILL
STALL AND BEGIN TO LOSE ITS BAROCLINICITY. MAX TEMPERATURES WILL
DEPEND ON THE AMOUNT OF SUNSHINE THAT CAN FILTER IN TO HELP OFFSET
SOME OF THE COLD AIR ADVECTION. IN GENERAL THINK THAT HIGHS WILL
CLIMB INTO THE LOW TO MID 80S...EXCEPT ACROSS FAR SOUTHEASTERN
ZONES WHERE UPPER 80S MAY BE POSSIBLE...ESPECIALLY IF THE FRONT
STALLS FURTHER NORTH THAN CURRENT EXPECTATIONS. WITH THE ZONAL
FLOW ALOFT ACROSS THE CENTRAL PLAINS...LOW LEVEL FLOW SHOULD TURN
AROUND TO THE EAST AND EVENTUALLY SOUTHEAST LATE THURSDAY NIGHT
INTO FRIDAY. HELD ON TO SOME LINGERING SLIGHT CHANCE POPS ACROSS
EASTERN ZONES WITH THE MOIST EAST FLOW AS ADVERTISED BY THE ECMWF
AND GFS. INSTABILITY APPEARS MEAGER...BUT WENT AHEAD AND MENTIONED
AN ISOLATED THUNDERSTORM OR TWO IN THE WORDED FORECASTS.
FOR FRIDAY...ANOTHER UPPER WAVE LOOKS TO MOVE EASTWARD OUT FROM
THE INTERMOUNTAIN WEST. THERE IS SOME WEAK LARGE SCALE ASCENT AS
EVIDENCED BY SOME UPPER LEVEL PV ACROSS THE NORTHERN AND
NORTHEASTERN ZONES. AS A RESULT...RETAINED INHERITED SLIGHT CHANCE
POPS ON FRIDAY. WITH THE RETURN TO THE SOUTH FLOW...EXPECT AN
INCREASE IN LOW LEVEL MOISTURE AND AN INCREASE IN THE
TEMPERATURES AS WELL. TEMPERATURES WILL CLIMB BACK TOWARDS
SEASONAL NORMS ON FRIDAY...OUTSIDE ANY PRECIPITATION THAT OCCURS.
&&
.LONG TERM (SATURDAY AND SUNDAY)...
FOR SATURDAY AND SUNDAY...MAINTAINED SLIGHT CHANCES FOR
PRECIPITATION ACROSS NORTHERN AND EASTERN ZONES WITH THESE AREAS
REMAINING ON THE NORTHERN AND EASTERN FRINGES OF A BUILDING MID
LEVEL RIDGE. HIGH TEMPERATURES SHOULD CLIMB INTO THE 90S AREA
WIDE ON SATURDAY. BOTH THE GFS AND ECMWF ADVERTISE A WEAK
BACKDOOR COLD FRONT SOMETIME LATE SUNDAY. THE RIDGE SHOULD
GRADUALLY WEAKEN ON ITS EASTERN PERIPHERY WHICH MAY ALLOW FOR THE
DEVELOPMENT OF SOME PRECIPITATION ALONG THE FRONT. AS A
RESULT...HAVE INTRODUCED LOW CHANCE POPS MAINLY ALONG THE RED
RIVER AND ACROSS EASTERN ZONES FOR SUNDAY AND INTO THE DAY ON
MONDAY. THERE ARE SOME DISCREPANCIES BETWEEN THE GFS AND THE ECMWF
IN THE LONG TERM WITH REGARDS TO HOW FAR SOUTH THIS NEXT COLD
FRONT WILL SWEEP SO CONFIDENCE IS NOT HIGH ENOUGH TO DEVIATE TOO
FAR FROM A CONSENSUS/BLENDED FORECAST.
BAIN
&&
.AVIATION...
/ISSUED 100 PM CDT WED AUG 19 2015/
/18Z TAFS/
COLD FRONT IS MOVING THROUGH THE DFW AREA NOW AND NORTH WINDS ARE
EXPECTED AT ALL THE DFW METROPLEX TAF SITES BY 19Z. SUSTAINED
WIND SPEEDS OF 12-16KTS WITH WIND GUSTS IN THE 15-25KT RANGE WILL
OCCUR BEHIND THE FRONT THROUGH THE AFTERNOON HOURS. THERE IS A
SMALL CHANCE FOR ISOLATED SHOWERS OR STORMS AS THE FRONT MOVES
THROUGH AND WILL CARRY A VCSH FOR TWO HOURS AFTER THE FRONT
PASSES. THEN A FEW DRY HOURS ARE EXPECTED WITH ANOTHER CHANCE FOR
SHOWERS OVERNIGHT. VFR CONDITIONS ARE EXPECTED TO PREVAIL BUT IT
IS POSSIBLE MVFR CIGS MAY DEVELOP OVERNIGHT OVER THE SHALLOW
SURFACE COLD FRONT.
THE FRONT IS EXPECTED TO REACH KACT AROUND 22-23Z BUT A WIND
SHIFT TO THE NORTH MAY OCCUR BEFORE THE TRUE FRONT ARRIVES. WILL
CARRY VCTS THROUGH THE AFTERNOON HOURS FOR CONVECTION DEVELOPING
AHEAD OF THE FRONT...AND THEN CONTINUE VCTS FOR ABOUT 2 HOURS
AFTER THE FRONT PASSES. ADDITIONAL SHOWERS ARE EXPECTED OVERNIGHT
ALONG WITH THE DEVELOPMENT OF MVFR CIGS.
JLDUNN
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 67 84 73 93 77 / 40 20 10 20 10
WACO, TX 69 83 74 94 76 / 30 30 20 10 5
PARIS, TX 63 79 64 89 73 / 40 20 20 30 30
DENTON, TX 63 82 69 93 76 / 40 10 10 20 20
MCKINNEY, TX 64 81 69 92 76 / 40 20 10 30 20
DALLAS, TX 68 85 74 94 78 / 40 20 10 20 10
TERRELL, TX 66 81 72 92 76 / 40 30 20 20 10
CORSICANA, TX 68 82 73 93 76 / 30 30 20 20 10
TEMPLE, TX 70 86 73 94 75 / 40 30 20 10 5
MINERAL WELLS, TX 64 83 70 94 75 / 40 20 10 20 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
82/15
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1237 PM CDT WED AUG 19 2015
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND THURSDAY
ISSUED AT 305 AM CDT WED AUG 19 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR ANALYSIS SHOW OCCLUDED
LOW PRESSURE SPINNING OVER SOUTHERN MINNESOTA AND A COLD FRONT
ARCING SOUTHWARD OVER EASTERN IOWA AND CENTRAL MISSOURI. A PRE-
FRONTAL TROUGH IN COMBINATION WITH A SHORTWAVE IS PUSHING A BROKEN
BAND OF SHOWERS NORTHEAST OVER NORTH-CENTRAL AND FAR NORTHEAST WI
EARLY THIS MORNING. THESE SHOWERS SHOULD DEPART BY 12Z. ADDITIONAL
LIGHT SHOWERS ARE OCCURRING ALONG THE COLD FRONT...WHICH WILL BE
REACHING CENTRAL WI BY 12Z. AS LOW PRESSURE AND COLD FRONT MOVE
NORTHEAST...PRECIP TRENDS ARE THE MAIN FORECAST CONCERNS.
TODAY...OCCLUDED LOW PRESSURE WILL LIFT INTO NORTHWEST WISCONSIN
EARLY THIS AFTERNOON AND INTO CENTRAL LAKE SUPERIOR BY EARLY THIS
EVENING. MEANWHILE THE COLD FRONT WILL MOVE ACROSS MOST OF THE
FORECAST AREA THIS MORNING EXCEPT FOR THE DOOR PENINSULA...WHICH
SHOULD OCCUR EARLY THIS AFTERNOON. SCATTERED SHOWERS WILL ACCOMPANY
THE COLD FRONT. BUT WITH DAYTIME HEATING...PROGGED SOUNDINGS
INDICATE THAT 500-800 J/KG OF CAPE COULD DEVELOP OVER NE WI AHEAD OF
THE FRONT. AS A RESULT...NOT OUT OF THE QUESTION THAT A FEW
THUNDERSTORMS COULD POP UP BY LATE IN THE MORNING ALONG THE
BOUNDARY. ANY THUNDERSTORMS WILL BE CAPABLE OF TRANSFERRING HIGHER
WINDS ALOFT TO THE SURFACE SO WILL KEEP A MENTION OF GUSTY WINDS
WITH ANY THUNDERSTORMS IN THE HWO. BEHIND THE FRONT...SOUTHWEST
WINDS WILL BECOME BREEZY IN THE AFTERNOON WITH SOME GUSTS TO 35 MPH
POSSIBLE. WRAP AROUND SHOWERS COULD ALSO MOVE INTO CENTRAL AND
NORTH-CENTRAL WI BY MID TO LATE AFTERNOON. HIGHS RANGING FROM THE
MID 60S WEST TO MID 70S EAST.
TONIGHT...THE UPPER TROUGH MOVES OVERHEAD AS THE SHORTWAVE IN THE
BASE OF THE TROUGH LIFTS NORTHWARD OVER EASTERN WISCONSIN. DEEPER
MOISTURE WILL ACCOMPANY THE TROUGH...WITH MOISTURE EXTENDING UPWARDS
OF 700MB OVERNIGHT. ANY BREAKS IN THE CLOUDS OVER EASTERN WISCONSIN
AT THE START OF THE NIGHT WILL THEREFORE LIKELY FILL IN AS THE
EVENING PROGRESSES AND WILL SPREAD A SLIGHT CHANCE OF RAIN ALL THE
WAY TO THE LAKESHORE. THE MORE PERSISTENT RAINS SHOULD FALL OVER
NORTH-CENTRAL WI WHERE A SURFACE TROUGH WILL MOVE THROUGH. LOWS
MAINLY IN THE 50S.
THURSDAY...THE UPPER TROUGH WILL CONTINUE TO BE OVERHEAD DURING THE
MORNING....WHICH SHOULD LEAD TO SCATTERED SHOWERS AND SPOTTY
DRIZZLE. THEN THE LIGHT PRECIP SHOULD COME TO AN END IN THE
AFTERNOON AS THE TROUGH LIFTS TO THE NORTHEAST. HIGHS RANGING FROM
THE LOW 60S NORTH TO LOW 70S SOUTH.
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY
ISSUED AT 305 AM CDT WED AUG 19 2015
THE TWO MAIN WEATHER FEATURES TO KEY ON DURING THE EXTENDED
PERIOD WL BE THE MOVEMENT OF THE NEXT PROMINENT SHORTWAVE
TROF/ASSOCIATED CDFNT ACROSS THE NRN TIER OF STATES THIS WEEKEND
INTO EARLY NEXT WEEK AND THE BUILDING OF AN UPR RDG OVER THE HI
PLAINS. THE MAIN STICKING POINT AMONG THE MODELS IS WHETHER THIS
SHORTWAVE TROF WL BE PROGRESSIVE OR CLOSE OFF INTO AN UPR LOW
SOMEWHERE NEAR THE GREAT LAKES. THE ANSWER TO THIS QUESTION WOULD
GO A LONG WAY IN DETERMINING THE WEATHER IN OUR AREA FROM SUNDAY
THRU TUE. AFTER A BRIEF WARM-UP THRU SAT...TEMPS ARE EXPECTED TO
FALL BELOW NORMAL FOR THE FIRST HALF OF NEXT WEEK.
THE GREAT LAKES REGION TO RESIDE ON THE NRN FRINGES OF AN AREA OF
HI PRES MOVING ALONG THE OHIO RIVER VALLEY THU NGT. CLEARING
SKIES...LIGHT WINDS AND AN INFLUX OF DRIER AIR SHOULD ALLOW TEMPS
TO FALL INTO THE MID 40S TO MID 50S RANGE WITH THE WARMER TEMPS
NEAR LAKE MI. WI TO GET ON THE BACKSIDE OF THIS RETREATING AREA OF
HI PRES ON FRI AS WINDS BACK TO THE S-SE. WAA WL GRADUALLY WORK
ACROSS THE AREA AS 8H TEMPS CLIMB TO AROUND +15C BY 00Z SAT. TEMPS
WL RESPOND WITH READINGS TOPPING OUT MAINLY IN THE MID 70S TO
AROUND 80 DEGS.
QUIET AND MILDER CONDITIONS EXPECTED FOR FRI NGT AS NE WI TO SIT
BETWEEN HI PRES TO OUR EAST AND DEVELOPING LOW PRES WELL TO OUR
WEST. BOUNDARY LAYER WINDS ARE FCST TO INCREASE THRU THE NGT AND
KEEP THE ATMOSPHERE MIXED...THEREBY PREVENTING TEMPS FROM FALLING
TOO FAR. LOOK FOR MINS TO RANGE FROM THE MID 50S TO AROUND 60 DEGS
NORTH...LWR 60S SOUTH. ATTENTION TO BE FOCUSED ON THE MOVEMENT OF
A SHARP SHORTWAVE TROF/ATTENDANT SFC CDFNT PROGGED TO REACH THE
NRN PLAINS ON SAT. THIS SYSTEM TO STILL BE TOO FAR AWAY TO IMPACT
NE WI...OTHER THAN BRING A BLUSTERY AND WARM DAY TO THE REGION.
MAX TEMPS WL RANGE FROM AROUND 80 DEGS NORTH/LAKESHORE...LWR 80S
SOUTH.
THE SHORTWAVE TROF TO PUSH EAST INTO THE UPR MS VALLEY SAT NGT...
AS THE CDFNT REACHES WRN WI BY DAYBREAK. EVEN THO INSTABILITY AND
FORCING ARE SOMEWHAT MARGINAL...THERE IS GOOD LIFT FROM THE CDFNT
AND THE 0-6KM BULK SHEAR VALUES ARE GREATER THAN 40 KTS
APPROACHING CNTRL WI LATE SAT NGT. HIGHEST POPS PLACED OVER CNTRL
WI WITH A POTENTIAL FOR PARTS OF ERN WI TO STAY DRY THRU THE NGT.
FCST CONFIDENCE IS A BIT BETTER NOW FOR SUNDAY AND BEYOND NOW THAT
THE 00Z ECMWF HAS KEPT THIS SHORTWAVE TROF PROGRESSIVE AND NOT TRY
TO CLOSE THE TROF INTO AN UPR LOW. PCPN CHCS WL CONT FOR SUNDAY AS
THE UPR TROF AND CDFNT MOVE THRU THE FCST AREA. TOKEN SMALL POPS
WERE LEFT IN THE FCST FOR MON AND TUE DUE TO THE UNCERTAINTY OF
THE MODELS HANDLING THIS SHORTWAVE TROF CORRECTLY. IF THE NEW 12Z
MODEL OUTPUTS ARE SIMILAR TO THE 00Z RUN...THEN POPS COULD BE
DROPPED FOR BOTH MON AND TUE WITH MORE SUNSHINE. ONE THING THAT IS
MORE CERTAIN WOULD BE THE DROP IN TEMPS BEHIND THE CDFNT FOR EARLY
NEXT WEEK. THIS WOULD BE ESPECIALLY TRUE ON MON WITH MAX TEMPS IN
THE UPR 60S TO THE LWR HALF OF THE 70S.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1228 PM CDT WED AUG 19 2015
OCCLUDED FRONT EXTENDED FROM LAND O LAKES TO NEAR MENOMINEE
MICHIGAN EARLY THIS AFTERNOON. SCATTERED SHOWERS AND PERHAPS
A FEW ISOLATED THUNDERSTORMS. THE STRONGEST STORMS WERE OVER
NORTHERN MARINETTE COUNTY. THE OCCLUDED FRONT WILL CONTINUE TO
PUSH TO THE NORTHEAST INTO UPPER MICHIGAN THIS AFTERNOON.
MEANWHILE...UPPER LOW IS EXPECTED TO MOVE EAST. A NEW WRINKLE
TO THE FORECAST FOR LATER TONIGHT IS THE INCREASED CHANCES FOR
SHOWERS AS AN UPPER LEVEL DISTURBANCE SWINGS AROUND THE UPPER LOW.
ADDED MORE RAIN TO THE FORECAST FOR THE KATW/KGRB/KMTW 18Z TAFS
FROM 06Z TO 12Z.
GUSTY SOUTHWEST WINDS WILL DIMINISH AROUND 00Z...WITH GUSTY
WEST WINDS TO AROUND 20 KNOTS EXPECTED AFTER 15Z THURSDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
BEACH HAZARDS STATEMENT UNTIL 8 PM CDT THIS EVENING FOR
WIZ022-040-050.
&&
$$
SHORT TERM.....MPC
LONG TERM......KALLAS
AVIATION.......ECKBERG