Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/12/14
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
830 PM MST THU SEP 11 2014
.SYNOPSIS...
THE COMBINATION OF A RATHER DRY AIRMASS AND HIGH PRESSURE ALOFT IS
EXPECTED TO KEEP SKIES MAINLY CLEAR OVER THE REGION THROUGH FRIDAY.
A VERY SLOW INCREASE IN MOISTURE WILL BEGIN LATE FRIDAY...THEN
CONTINUE INTO THE WEEKEND...AND INTO NEXT WEEK AS THE FLOW ALOFT
BECOMES MORE SOUTHEASTERLY. THIS WILL LEAD TO INCREASED CHANCES OF
SHOWERS AND THUNDERSTORMS...INITIALLY OVER MOUNTAINOUS AREAS OVER
THE WEEKEND...BUT POSSIBLY SPREADING INTO LOWER DESERT LOCATIONS BY
EARLY NEXT WEEK.
&&
.DISCUSSION...
A SECOND QUIET DAY IN A ROW ACROSS THE CWA WITH JUST SOME AFTERNOON
CU MANAGING TO APPEAR. TEMPERATURES THIS EVENING ARE RUNNING 3-5
DEGREES WARMER THAN YESTERDAY AT THIS TIME...BUT WITH A DRIER
BOUNDARY LAYER AND LITTLE CHANGE TO THE OVERLYING ATMOSPHERE WE
SHOULD STILL EXPECT SIMILAR OVERNIGHT LOWS TO LAST NIGHT. NO CHANGES
ARE NEEDED TO THE CURRENT FORECAST.
&&
.PREVIOUS DISCUSSION...
LATEST RAP STREAMLINE ANALYSIS SHOWS A WEAK UPPER LEVEL TROUGH
SITUATED ACROSS AZ. SOMEWHAT DEEPER MOISTURE IS EVIDENT ON WV
IMAGERY EAST OF THE TROUGH ACROSS SOUTHERN AND EASTERN AZ...THOUGH
REGIONAL SOUNDINGS INDICATE PWATS ARE ONLY IN THE 1.0-1.2 INCH
RANGE.
CONTINUED WARMING AND DRYING TREND EXPECTED FRIDAY AS THE
SUBTROPICAL RIDGE REMAINS THE PREDOMINANT WEATHER FEATURE.
AGAIN...LITTLE CHANCE FOR CONVECTION EXCEPT FOR ISOLATED ACTIVITY IN
THE VICINITY OF THE DEEPEST MOISTURE ACROSS SOUTHEASTERN AZ.
SATURDAY AND SUNDAY...
A SLOW INCREASE IN THE AVAILABLE MOISTURE LEVELS IS STILL EXPECTED
TO OCCUR OVER THE UPCOMING WEEKEND AS THE FLOW BELOW 400MB BECOMES
EASTERLY TO SOUTHEASTERLY...AND BEGINS TO PULL MOISTURE BACK INTO
THE REGION. THE GFS IS MOST BULLISH ON THIS MOISTURE
INCREASE...PUSHING PWATS UP TO NEAR 1.50 ON SATURDAY...WHILE THE
EURO KEEPS THEM MAINLY AOB 1.20 INCH. CONSIDERING THAT THE PRIMARY
REASON FOR THE INCREASE IN THE SFC PRESSURE GRADIENT/EASTERLY FLOW
IN THE LOW LEVELS IS THE FACT THAT A RATHER STRONG...AND QUITE COLD
SFC HIGH IS FORECAST TO DIVE SOUTHWARD INTO THE CENTRAL AND SOUTHERN
PLAINS...WITH ITS ORIGINS BEING FROM NORTHERN CANADA/ALASKA...RATHER
THAN A MORE TYPICAL SUBTROPICAL HIGH THAT OFTEN BUILDS OVER THAT
REGION THIS TIME OF YEAR...I AM INCLINED TO GO WITH THE DRIER EURO
FOR NOW. STILL...THERE SHOULD BE ENOUGH MOISTURE/INSTABILITY TO KEEP
SLIGHT CHANCES FOR SHOWERS/THUNDERSTORMS OVER THE HIGHER TERRAIN
NORTH AND EAST OF PHOENIX IN THE FORECAST...BUT WITH MAINLY SINGLE
DIGIT POPS OVER THE LOWER DESERTS. HIGH TEMPERATURES ARE EXPECTED TO
REMAIN MOSTLY IN THE 105-108F RANGE ACROSS SE CA AND SW AZ...BUT
COOL A DEGREE OR TWO OVER SOUTH-CENTRAL AZ AS A BIT OF COOLER AIR
WORKS ITS WAY IN FROM THE EAST.
MONDAY THROUGH WEDNESDAY...
A FURTHER MOISTURE INCREASE IS STILL EXPECTED DURING THIS TIME
PERIOD AS HURRICANE ODILE MOVES NORTHWESTWARD JUST OFF THE WEST
COAST OF BAJA CALIFORNIA. DEEP SE-LY FLOW TO THE EAST AND NORTHEAST
OF ODILE WILL LIKELY PUSH ADDITIONAL MOISTURE NORTHWESTWARD UP THE
GULF OF CALIFORNIA...AND INTO THE DESERT SOUTHWEST. ALTHOUGH THERE
WILL LIKELY BE ENOUGH INCREASE IN AVAILABLE MOISTURE TO TRIGGER AT
LEAST ISOLATED THUNDERSTORMS ACROSS THE LOWER DESERTS OF AZ/SE CA
DURING THIS PERIOD...IT STILL APPEARS THAT WE WILL NOT SEE ANYTHING
CLOSE TO WHAT WE SAW EARLIER THIS WEEK...SINCE LATEST MODEL SUITES
ARE IN VERY STRONG AGREEMENT THAT ODILE WILL TRACK WELL OFF TO OUR
SOUTH AND WEST...EVENTUALLY DISSIPATING OVER THE COOLER WATERS OF
THE EASTERN PACIFIC...WELL OFF THE SOUTHERN CA COAST...WITH MOST OF
ITS ASSOCIATED MOISTURE REMAINING FAR AWAY FROM OUR REGION.
THUS...ONCE AGAIN GOING WITH THE DRIER EURO...WHICH KEEPS OUR PWATS
MAINLY AOB 1.50 INCH THROUGH THIS PERIOD.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
NO AVIATION IMPACTS THROUGH FRIDAY EVENING. WINDS WILL REMAIN LIGHT
THROUGH THE PERIOD AND GENERALLY FOLLOW NORMAL DIURNAL TRENDS. AM
EXPECTING AN INCREASE IN SHOWER AND THUNDERSTORM ACTIVITY ACROSS FAR
EASTERN ARIZONA FRIDAY AFTERNOON...BUT TERMINALS WILL NOT BE
AFFECTED.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
INCREASING LOW TO MID LEVEL EASTERLY WINDS WILL DEVELOP OVER THE
WEEKEND...HELPING TO SPREAD MONSOONAL MOISTURE AND AN INCREASING
THREAT OF AFTERNOON AND EVENING THUNDERSTORMS BACK OVER THE REGION.
BY SUNDAY A SLIGHT CHANCE OF THUNDERSTORMS IS FORECAST ACROSS THE
ARIZONA DESERTS. HUMIDITY VALUES ACROSS THE DESERTS WILL BEGIN A
STEADY RISE OVER THE WEEKEND AND INTO NEXT WEEK WITH MINIMUM VALUES
FOR MOST AREAS CLIMBING ABOVE 20 PERCENT BY SUNDAY. OVERNIGHT
RECOVERY WILL BE GENERALLY GOOD THROUGH MONDAY WITH MAX HUMIDITY
VALUES CLIMBING ABOVE 50 PERCENT EACH NIGHT...BECOMING GOOD TO
EXCELLENT EARLY NEXT WEEK WITH MANY DESERT LOCALES EXCEEDING 70
PERCENT BY WEDNESDAY MORNING. THE BREEZY EAST WINDS SEEN OVER THE
WEEKEND WILL DIMINISH THROUGH THE MIDDLE OF NEXT WEEK...FAVORING THE
SOUTH TO SOUTHWEST DIRECTIONS AT GENERALLY LESS THAN 15 MPH.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...KUHLMAN
PREVIOUS DISCUSSION...HIRSCH/PERCHA
AVIATION...KUHLMAN
FIRE WEATHER...MCLANE/CB
AREA FORECAST DISCUSSION
NWS TUCSON AZ
920 AM MST WED SEP 10 2014
.SYNOPSIS...MAINLY DRY CONDITIONS WILL OCCUR THROUGH THURSDAY.
EXPECT ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS TO
RETURN BY THIS WEEKEND AS MOISTURE INCREASES ACROSS THE AREA. A
WARMING TREND WILL PREVAIL THROUGH FRIDAY FOLLOWED BY MODEST COOLING
EARLY THIS WEEKEND.
&&
.DISCUSSION...A NARROW BAND OF CLOUDINESS EXTENDED FROM THE WHITE
MOUNTAINS SWWD INTO WRN PIMA COUNTY AT THIS TIME. A FEW SHOWERS
PRODUCING MOSTLY SPRINKLES CONTINUED ACROSS FAR WRN PIMA COUNTY.
OTHERWISE...SUNNY SKIES OR MOSTLY SUNNY SKIES PREVAILED ACROSS SE
AZ. DEWPOINTS AT LOWER ELEVATIONS VALID 16Z WERE GENERALLY IN THE
MID-UPPER 50S F. THESE TEMPS WERE ABOUT 5-10 DEGS F LOWER VERSUS 24
HOURS AGO. SURFACE TEMPS VALID 16Z WERE NEARLY IDENTICAL TO THIS
TIME TUE. BLENDED TOTAL PRECIP WATER IMAGERY VALID 1357Z DEPICTED
VALUES RANGING FROM AROUND THREE QUARTERS OF AN INCH ACROSS THE
WHITE MOUNTAINS TO 1.20 INCHES ACROSS WRN PIMA COUNTY.
THE BEST CHANCE FOR MEASURABLE PRECIP INTO THIS EVENING WILL BE
ACROSS THE WHITE MOUNTAINS AS PER THE 10/12Z NAM/GFS...THE 10/12Z
UNIV OF AZ WRF-NAM...AND THE 10/14Z RUC HRRR. HAVE OPTED TO REDUCE
POPS ACROSS THE WHITE MOUNTAINS...BUT HAVE MAINTAINED A SLIGHT
CHANCE OF SHOWERS THERE INTO THIS EVENING. HAVE ALSO MAINTAINED A
SLIGHT CHANCE OF SHOWERS ACROSS FAR WRN PIMA COUNTY INTO THIS
AFTERNOON. DRY CONDITIONS WILL PREVAIL ELSEWHERE THRU TONIGHT. HIGH
TEMPS THIS AFTERNOON ARE FORECAST TO BE JUST A COUPLE OF DEGS OR SO
WARMER VERSUS TUE.
PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.
&&
.AVIATION...VALID THRU 11/18Z.
ISOLATED -SHRA ACROSS FAR WRN PIMA COUNTY WEST OF KTUS AND ACROSS
THE WHITE MOUNTAINS NE OF KSAD INTO THIS EVENING. OTHERWISE...EXPECT
A FEW TO OCCASIONALLY BKN CLOUDS AT 8-12K FT AGL AND SURFACE WIND TO
BE LESS THAN 10 KTS INTO THURSDAY MORNING. AVIATION DISCUSSION NOT
UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...THERE IS A SLIGHT CHANCE OF AFTERNOON SHOWERS MAINLY
ACROSS THE WHITE MOUNTAINS THROUGH THURSDAY. ISOLATED TO SCATTERED
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL THEN RETURN
STARTING FRIDAY AND CONTINUE INTO EARLY NEXT WEEK AS MOISTURE
INCREASES ACROSS THE AREA. OTHERWISE...20-FOOT WINDS WILL GENERALLY
BE LIGHT AND TERRAIN DRIVEN...EXCEPT FOR STRONG GUSTY OUTFLOWS
ASSOCIATED WITH THUNDERSTORMS.
&&
.PREV DISCUSSION...MINIMAL SHOWERS AND THUNDERSTORMS EXPECTED AGAIN
ON THURSDAY AND AGAIN MOSTLY FOR THE MOUNTAINS AND AREAS ALONG THE
NEW MEXICO BORDER. BY FRIDAY HIGH PRESSURE OVER THE CENTRAL GULF
COAST AND EXTENDING WEST ALONG THE SOUTHERN TIER OF STATES WILL
RESULT IN A SOUTHEAST FETCH ON THE SOUTHERN FLANK OF THE
RIDGE...WHICH WILL HELP TO USHER IN ADDITIONAL MOISTURE FOR A
INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS. EVEN SO...ONLY
LOOKING AT ISOLATED SHOWERS AND THUNDERSTORMS FOR CENTRAL
ZONES...SUCH AS TUCSON...WITH SCATTERED ACTIVITY FOR AREAS SOUTH AND
EAST OF TUCSON. THIS SET UP WILL GENERALLY CONTINUE THROUGH THE
WEEKEND THROUGH EARLY NEXT WEEK. ANOTHER TROPICAL SYSTEM IS PROGGED
TO REACH THE SOUTHERN TIP OF THE BAJA PENINSULA BY LATE SUNDAY/EARLY
MONDAY...BUT IT IS TOO EARLY TO HANG OUR HATS ON ONE PARTICULAR
SOLUTION...OR TO TRY AND COMPARE THIS NEXT SYSTEM WITH WHAT OCCURRED
WITH NORBERT. THEREFORE...STAY TUNED FOR CONTINUOUSLY UPDATED AND
REVISED FORECASTS BETWEEN NOW AND EARLY NEXT WEEK.
HIGH TEMPERATURES WILL GENERALLY RANGE FROM 1 TO 3 DEGS BELOW NORMAL
TODAY...THEN 1 TO 3 DEGS ABOVE NORMAL FOR THURSDAY AND FRIDAY.
THEREAFTER...HIGHS HOVERING NEAR NORMAL. LOWS WILL BE NEAR TO
SLIGHTLY ABOVE NORMAL THURSDAY MORNING...THEN 4 TO 6 DEGS ABOVE
NORMAL EACH MORNING THEREAFTER.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
FRANCIS
PREVIOUS DISCUSSION...MOLLERE
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
853 PM MDT THU SEP 11 2014
.UPDATE...
ISSUED AT 842 PM MDT THU SEP 11 2014
COLD FRONT CONTINUES TO DROP SOUTH ACROSS NORTHWEST COLORADO AND
LOOKS LIKE IT WILL JUMP THE BOOKCLIFFS SHORTLY SENDING COOLER
CONDITIONS THROUGH THE INTERSTATE 70 CORRIDOR. IN ADDITION...ISOLATED
SHOWERS HANGING ON ALONG INTERSTATE 70 FROM GLENWOOD TO VAIL
PASS. GUSTY WINDS AND LIGHT RAIN WILL BE THE PRIMARY CONCERN WITH
THESE DECAYING SHOWERS. GRIDS HAVE BEEN MODIFIED AND NEW ZONES
SENT.
UPDATE ISSUED AT 502 PM MDT THU SEP 11 2014
SHOWERS HAVE JUMPED UP A BIT IN INTENSITY ACROSS THE FLAT TOPS
NORTH OF INTERSTATE 70. AS DISCUSSED BELOW...DOWNSCALED MODELS
PICKING UP ON THIS ACTIVITY WITH THE HRRR ALSO JOINING IN. HAVE
NUDGED POPS UP A BIT ACROSS THE FLAT TOPS AND ACROSS PORTIONS OF
MOFFAT AND ROUTT COUNTIES THROUGH EARLY THIS EVENING. THIS
ACTIVITY WILL QUICKLY DIMINISH BY SUNSET WITH CLEAR AND COLD
CONDITIONS ON TAP OVERNIGHT.
&&
.SHORT TERM...(TONIGHT THROUGH FRIDAY NIGHT)
ISSUED AT 300 PM MDT THU SEP 11 2014
TIGHTENING PRESSURE GRADIENT OVER NW COLORADO IS PRODUCING SOME
OROGRAPHIC CLOUD AND GUSTY SURFACE WINDS TO 25 KTS. DOWNSCALED
NAMDNG25 AND RAP13 PAINTS A THIN RIBBON OF LIGHT SHOWERS FROM
BOOKCLIFFS TO THE FLAT TOPS BY LATE AFTERNOON. VISUAL SATELLITE
IMAGES DO SHOW LOW TOP CONVECTION IS FORMING OVER THE HIGHER
TERRAIN OF NW AND WC COLORADO...SO SCENARIO APPEARS TO BE IN PLAY.
ANY LIGHT SHOWERS WILL DISSIPATE WITH SUNSET.
SURFACE COLD FRONT FROM WYOMING DROPS INTO NW COLORADO EARLY THIS
EVENING AND SPREADS SOUTHWARD. APPEARS THIS FRONT REACHES THE I70
CORRIDOR LATE THIS EVENING...BUT DOES NOT GO MUCH FARTHER SOUTH.
MINIMAL MOISTURE WITH THE FRONT AND NOT EXPECTING ANY WEATHER
EXCEPT FOR A WIND SHIFT TO N-NE. DRIER AIR MASS FILTERING INTO NW
COLORADO WILL ALLOW TEMPS TO FALL BELOW FREEZING ALONG THE RIVER
VALLEYS AND LOW LYING SPOTS. CONFIDENCE IS HIGH THIS WILL OCCUR
WITH MID TO UPPER 20S IN THE YAMPA AND WHITE RIVER BASINS. WILL
UPGRADE THE FREEZE WATCH TO FREEZE WARNING AND INCLUDE STEAMBOAT
SPRINGS VICINITY.
GRADIENT FLOW RELAXES ON FRIDAY AS COLD TROUGH MOVES ACROSS THE
CENTRAL PLAINS. AIR MASS WILL BE SIGNIFICANTLY DRIER AND WILL MEAN
MORE SUNSHINE FOR THE ENTIRE REGION. COOLER MAX TEMPS ACROSS THE
NORTH...BUT NEAR PERSISTENCE FOR THE SOUTHERN HALF.
INTERESTINGLY MODEL DATA SHOWS A LITTLE MOISTURE FILTERING INTO
ARCHULETA COUNTY ON FRIDAY NIGHT. NOT CONVINCED THAT LIGHT PCPN
WILL FORM DURING THE NOCTURNAL HOURS...WILL KEEP THE DRY FORECAST
ONGOING. IF NOTHING ELSE...SOME SHALLOW UPSLOPE FLOW MAY PRODUCE
SCATTERED CLOUDS. OTHERWISE BENIGN WEATHER CONDITIONS PERSIST
THROUGH FRIDAY NIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 300 PM MDT THU SEP 11 2014
THE LAST IN A SERIES OF TROUGHS WORKS THROUGH THE NORTHERN TIER OF
STATES ON SATURDAY. THIS ALLOWS THE SUBTROPICAL HIGH...THAT HAS
BEEN SQUASHED ALONG THE GULF COAST STATES...TO BEGIN TO AMPLIFY
WESTWARD INTO THE DESERT SW. DAYTIME TEMPERATURES REBOUND TO NEAR
NORMAL AFTER FRIDAY/S COOL DOWN. ALSO MOISTURE WILL BEGIN TO
PERCOLATE NORTH THROUGH AZ-NM INTO THIS FORECAST AREA. MARGINAL
MOISTURE OVER THE WEEKEND WILL PRODUCE MAINLY AFTERNOON MOUNTAIN
THUNDERSTORMS PRODUCING MORE WIND THAN RAIN.
MOISTURE INCREASES EARLY NEXT WEEK AS HIGH PRESSURE AMPLIFIES
NORTHWARD ALONG THE SPINE OF THE ROCKIES. NO ORGANIZED FORCING
SEEN FOR NOW...SO EXPECT SCATTERED AFTERNOON TO EARLY EVENING
STORMS AND SOME CHANCE OF LOCALLY HEAVIER SHOWERS DUE TO SLOW
STORM MOTION.
FOR WEDNESDAY INTO THURSDAY WE ARE WATCHING TROPICAL STORM ODILE
THAT MAY MAKE HURRICANE STATUS AS IT WORKS ITS WAY UP ALONG THE
MEXICAN WEST COAST. THE MORE PROGRESSIVE GFS PULLS ODILE MOISTURE
INTO THE REGION AS A PACIFIC TROUGH SWEEPS THE WEST. THE EC KEEPS
THE ROCKIES RIDGE IN PLACE WHICH FORCES ODILE OUT TO SEA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY EVENING) ISSUED
AT 847 PM MDT THU SEP 11 2014
A COLD FRONT WILL SLIDE SOUTH OF INTERSTATE 70 THIS MORNING WITH
CLEARING AND COLD CONDITIONS EXPECTED OVERNIGHT. DECAYING SHOWERS
ALONG INTERSTATE 70 FROM GLENWOOD SPRINGS TO VAIL PASS WILL
DIMINISH BY 07Z. GUSTY OUTFLOW WINDS TO 30 MPH AND LIGHT RAIN
WILL ACCOMPANY THE SHOWERS. OTHERWISE...VFR CONDITIONS ARE
EXPECTED THROUGHOUT THE PERIOD.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...FREEZE WARNING FROM 2 AM TO 9 AM MDT FRIDAY FOR COZ002-005.
UT...NONE.
&&
$$
UPDATE...JDC
SHORT TERM...PF
LONG TERM...JOE
AVIATION...JDC
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
754 PM MDT THU SEP 11 2014
.UPDATE...
ISSUED AT 754 PM MDT THU SEP 11 2014
COLD MOIST AIRMASS WILL REMAIN OVER NORTHEAST COLORADO TONIGHT AND
INTO FRIDAY AFTERNOON. NORTHEAST WINDS WILL CONTINUE TO USHER IN
COLDER AIR. TEMPERATURES LOOK TO STAY IN THE 33 TO 37 DEGREE RANGE
LATE TONIGHT ALONG THE FRONT RANGE...AS THE LATEST HRRR AND RAP
INDICATE. HOWEVER...AREAS ABOVE 6000 FEET WILL LIKELY REACH
AND DROP FREEZING.
FORECASTING PRECIPITATION TYPE REMAINS VERY CHALLENGING. AIRMASS
WILL REMAIN SATURATED UP TO 10000 TO 13000 FEET MSL. THIS WILL
CONTINUE TO SUPPORT DRIZZLE ALONG THE FRONT RANGE. THE SATURATED
LAYER GENERALLY STAYS WARMER THAN -4C...WHICH MEANS NO ICE IN THIS
LAYER. SO UNLESS SOME SHOWERS FORM IN COLDER AREAS ABOVE THIS
LAYER...PRECIPITATION SHOULD REMAIN DRIZZLE. THERE IS SOME LIFT
OVERHEAD DUE TO THE JET AND IS PRODUCING A FEW SHOWERS. THIS WOULD
SUPPORT SOME RAIN...AND LATER TONIGHT SNOW. SO THINKING DRIZZLE WILL
BE THE MAIN PRECIPITATION TYPE OVERNIGHT. HOWEVER...SOME RAIN THIS
EVENING AND SNOW AFTER MIDNIGHT WILL BE SCATTERED ABOUT. BEST CHANCE
FOR THE RAIN AND SNOW WILL BE OVER THE EASTERN PLAINS WHERE THE BEST
LIFT WILL OCCUR. NOT EXPECTING MUCH IF ANY SNOW ACCUMULATION ALONG
THE FRONT RANGE. HOWEVER...OVER WASHINGTON AND LINCOLN COUNTIES...A
COUPLE OF INCHES WILL BE POSSIBLE IF A HEAVY BAND FORMS.
WILL TWEAK THE FORECAST TO SAY FOG AND DRIZZLE WITH A CHANCE FOR
RAIN AND SNOW FOR THE FRONT RANGE. SNOW WILL BE LIKELY OVER THE
EASTERN PLAINS LATE TONIGHT AND EARLY FRIDAY MORNING.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH FRIDAY)
ISSUED AT 1107 AM MDT THU SEP 11 2014
EVENTS ARE UNFOLDING ABOUT AS PLANNED. STILL AREAS OF DRIZZLE ON
THE PLAINS WITH SUNSHINE AND MILD TEMPERATURES WEST OF THE FRONT
RANGE. EXPECTED AREA OF LIFT DEVELOPING ALONG THE COLORADO/WYOMING
BORDER WITH SHOWERS BREAKING OUT AROUND CHEYENNE. SECONDARY FRONT
STRENGTHENING NOW ACROSS SOUTHEAST WYOMING WITH PRESSURE RISES IN
WYOMING AND FALLS IN SOUTHWESTERN COLORADO. THIS WILL PUSH COLDER
LOW LEVEL AIR INTO NORTHERN COLORADO LATER THIS EVENING. WITH THIS
TIMING I BACKED OFF A LITTLE ON THE TIME THE SNOW WILL
BEGIN...KEEPING IT NORTH OF BOULDER AND GREELEY UNTIL AFTER 10 PM.
WITH THE FORECAST HINGING ON A COUPLE OF DEGREES WE WILL KEEP RAIN
AND SNOW WORDING...BUT SUSPECT IT WILL CHANGE OVER TO ALL SNOW IN
MOST AREAS IN THE EARLY MORNING HOURS. THE SNOW WILL PROBABLY BE
ALL SOUTH OF INTERSTATE 76 BY SUNRISE AND OUT OF OUR AREA BY LATE
MORNING. EVEN WITH SOME BANDING THAT COULD PRODUCE MODERATE
SNOWFALL...GROUND TEMPERATURES ARE VERY WARM AND THE AIR WILL
BARELY BE COLD ENOUGH FOR SNOW...SO MOST PLACES WILL LIKELY JUST
HAVE A DUSTING ON THE GRASS. HARDEST HIT SPOTS COULD HAVE AN INCH
OR TWO ON THE GRASS...BUT STILL NOT EXPECTING ANY TRAVEL
ISSUES...EVEN IN THE FOOTHILLS THE GROUND IS PRETTY WARM.
FOR FRIDAY STRATUS MAY HANG IN ON THE STRENGTHENING SOUTHEAST FLOW
MUCH OF THE DAY...BUT STILL EXPECTING CLEARING LATE IN THE DAY.
IT WILL BE WARMING ALOFT AND MOUNTAIN TEMPERATURES WILL LIKELY
RECOVER TO TODAYS LEVELS...FORECAST FOR THE PLAINS LOOKS GOOD WITH
HIGHS AROUND 50 UNDER THE INVERSION.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 1107 AM MDT THU SEP 11 2014
UPSLOPE WILL CONTINUE FRIDAY EVENING AS THE SURFACE HIGH PRESSURE
CONTINUES TO MAKE ITS WAY SOUTH AND EAST INTO KANSAS. A SURFACE
TROUGH WILL DROP DOWN FROM WYOMING AND HELP TO TRANSITION THE
WINDS TO A MORE NORTHWEST DIRECTION AND HELP TO CLEAR OUT THE LOW-LYING
CLOUDS. THIS WARMER AIR COMBINED WILL DOWNSLOPING WINDS STARTING
AROUND 06Z ACCORDING TO THE MODELS WILL AID IN RADIATION COOLING
AND ALLOW SOME AREAS TO FORM PATCHY FOG EARLY SATURDAY MORNING.
AREAS OUT IN THE NORTHEAST PORTIONS OF THE CWA COULD SEE SOME
PATCHY FROST WITH THE DEWPOINTS GETTING CLOSE TO FREEZING BY 12Z
SATURDAY.
A SURFACE HIGH WILL MOVE NORTH FROM THE SOUTHWEST AND COMBINE WITH
AN UPPER LEVEL RIDGE MOVING IN TO START THE DRYING OUT FOR THE
WEEKEND. SATURDAY WILL BEGIN THE WARM UP WITH TEMPERATURES
REACHING BACK INTO THE 70S AND LOWER 80S BY SUNDAY. WITH INCREASED
MOISTURE IN THE MOUNTAINS...THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS IN THE AFTERNOON.
MODELS ARE PICKING UP ON A WEAK UPPER LEVEL TROUGH THAT WILL BRING
A SURFACE FRONT DOWN INTO NE COLORADO MONDAY AFTERNOON. AS THE
FRONT MOVES INTO THE CWA FLOW WILL CHANGE TO A MORE EASTERLY TO
NORTHEASTERLY DIRECTION BRINGING COLD AIR DOWN AND PUTTING A BREAK
ON THE WARM UP FOR THE START OF NEXT WEEK. SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE DURING THE MORNING INTO THE
AFTERNOON MONDAY.
FOR TUESDAY AND WEDNESDAY UPPER LEVEL RIDGING WILL RETURN WITH
INCREASING TEMPERATURES AND JUST A SLIGHT CHANCE OF SHOWERS OVER
THE MOUNTAINS IN THE AFTERNOON.
&&
.AVIATION...(FOR THE TAFS THROUGH 06Z FRIDAY EVENING)
ISSUED AT 754 PM MDT THU SEP 11 2014
LOW CLOUDS WITH CEILINGS MAINLY LESS THAN 500 ARE EXPECTED TO
PREVAIL THROUGH 15Z AND THEN SLOWLY LIFT THROUGH THE DAY FRIDAY.
VISIBILITY WILL FALL THROUGH THE NIGHT...BOTTOMING OUT AT A QUARTER
TO A HALF MILE. PRECIPITATION IS EXPECTED TO BE MAINLY DRIZZLE
OVERNIGHT WITH A FEW PERIODS RAIN THIS EVENING AND SNOW AFTER
MIDNIGHT POSSIBLE. IF SNOW FALLS...ANY ACCUMULATION WILL BE VERY
LIGHT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MEIER
SHORT TERM...GIMMESTAD
LONG TERM...BOWEN
AVIATION...MEIER
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
518 PM MDT THU SEP 11 2014
.UPDATE...
ISSUED AT 502 PM MDT THU SEP 11 2014
SHOWERS HAVE JUMPED UP A BIT IN INTENSITY ACROSS THE FLAT TOPS
NORTH OF INTERSTATE 70. AS DISCUSSED BELOW...DOWNSCALED MODELS
PICKING UP ON THIS ACTIVITY WITH THE HRRR ALSO JOINING IN. HAVE
NUDGED POPS UP A BIT ACROSS THE FLAT TOPS AND ACROSS PORTIONS OF
MOFFAT AND ROUTT COUNTIES THROUGH EARLY THIS EVENING. THIS
ACTIVITY WILL QUICKLY DIMINISH BY SUNSET WITH CLEAR AND COLD
CONDITIONS ON TAP OVERNIGHT.
&&
.SHORT TERM...(TONIGHT THROUGH FRIDAY NIGHT)
ISSUED AT 300 PM MDT THU SEP 11 2014
TIGHTENING PRESSURE GRADIENT OVER NW COLORADO IS PRODUCING SOME
OROGRAPHIC CLOUD AND GUSTY SURFACE WINDS TO 25 KTS. DOWNSCALED
NAMDNG25 AND RAP13 PAINTS A THIN RIBBON OF LIGHT SHOWERS FROM
BOOKCLIFFS TO THE FLAT TOPS BY LATE AFTERNOON. VISUAL SATELLITE
IMAGES DO SHOW LOW TOP CONVECTION IS FORMING OVER THE HIGHER
TERRAIN OF NW AND WC COLORADO...SO SCENARIO APPEARS TO BE IN PLAY.
ANY LIGHT SHOWERS WILL DISSIPATE WITH SUNSET.
SURFACE COLD FRONT FROM WYOMING DROPS INTO NW COLORADO EARLY THIS
EVENING AND SPREADS SOUTHWARD. APPEARS THIS FRONT REACHES THE I70
CORRIDOR LATE THIS EVENING...BUT DOES NOT GO MUCH FARTHER SOUTH.
MINIMAL MOISTURE WITH THE FRONT AND NOT EXPECTING ANY WEATHER
EXCEPT FOR A WIND SHIFT TO N-NE. DRIER AIR MASS FILTERING INTO NW
COLORADO WILL ALLOW TEMPS TO FALL BELOW FREEZING ALONG THE RIVER
VALLEYS AND LOW LYING SPOTS. CONFIDENCE IS HIGH THIS WILL OCCUR
WITH MID TO UPPER 20S IN THE YAMPA AND WHITE RIVER BASINS. WILL
UPGRADE THE FREEZE WATCH TO FREEZE WARNING AND INCLUDE STEAMBOAT
SPRINGS VICINITY.
GRADIENT FLOW RELAXES ON FRIDAY AS COLD TROUGH MOVES ACROSS THE
CENTRAL PLAINS. AIR MASS WILL BE SIGNIFICANTLY DRIER AND WILL MEAN
MORE SUNSHINE FOR THE ENTIRE REGION. COOLER MAX TEMPS ACROSS THE
NORTH...BUT NEAR PERSISTENCE FOR THE SOUTHERN HALF.
INTERESTINGLY MODEL DATA SHOWS A LITTLE MOISTURE FILTERING INTO
ARCHULETA COUNTY ON FRIDAY NIGHT. NOT CONVINCED THAT LIGHT PCPN
WILL FORM DURING THE NOCTURNAL HOURS...WILL KEEP THE DRY FORECAST
ONGOING. IF NOTHING ELSE...SOME SHALLOW UPSLOPE FLOW MAY PRODUCE
SCATTERED CLOUDS. OTHERWISE BENIGN WEATHER CONDITIONS PERSIST
THROUGH FRIDAY NIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 300 PM MDT THU SEP 11 2014
THE LAST IN A SERIES OF TROUGHS WORKS THROUGH THE NORTHERN TIER OF
STATES ON SATURDAY. THIS ALLOWS THE SUBTROPICAL HIGH...THAT HAS
BEEN SQUASHED ALONG THE GULF COAST STATES...TO BEGIN TO AMPLIFY
WESTWARD INTO THE DESERT SW. DAYTIME TEMPERATURES REBOUND TO NEAR
NORMAL AFTER FRIDAY/S COOL DOWN. ALSO MOISTURE WILL BEGIN TO
PERCOLATE NORTH THROUGH AZ-NM INTO THIS FORECAST AREA. MARGINAL
MOISTURE OVER THE WEEKEND WILL PRODUCE MAINLY AFTERNOON MOUNTAIN
THUNDERSTORMS PRODUCING MORE WIND THAN RAIN.
MOISTURE INCREASES EARLY NEXT WEEK AS HIGH PRESSURE AMPLIFIES
NORTHWARD ALONG THE SPINE OF THE ROCKIES. NO ORGANIZED FORCING
SEEN FOR NOW...SO EXPECT SCATTERED AFTERNOON TO EARLY EVENING
STORMS AND SOME CHANCE OF LOCALLY HEAVIER SHOWERS DUE TO SLOW
STORM MOTION.
FOR WEDNESDAY INTO THURSDAY WE ARE WATCHING TROPICAL STORM ODILE
THAT MAY MAKE HURRICANE STATUS AS IT WORKS ITS WAY UP ALONG THE
MEXICAN WEST COAST. THE MORE PROGRESSIVE GFS PULLS ODILE MOISTURE
INTO THE REGION AS A PACIFIC TROUGH SWEEPS THE WEST. THE EC KEEPS
THE ROCKIES RIDGE IN PLACE WHICH FORCES ODILE OUT TO SEA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 502 PM MDT THU SEP 11 2014
NARROW BAND OF SHOWERS AND THUNDERSTORMS WILL PERSIST ACROSS THE
FLAT TOPS NORTH OF INTERSTATE 70 OR ROUGHLY FROM KRIL TO THE
CONTINENTAL DIVIDE THROUGH 02Z THIS EVENING...BEFORE DISSIPATING.
SKIES CLEAR AFTER 03Z...WITH VFR CONDITIONS EXPECTED ACROSS ALL OF
EASTERN UTAH AND WESTERN COLORADO THROUGH FRIDAY.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...FREEZE WARNING FROM 2 AM TO 9 AM MDT FRIDAY FOR COZ002-005.
UT...NONE.
&&
$$
UPDATE...JDC
SHORT TERM...PF
LONG TERM...JOE
AVIATION...JDC
AREA FORECAST DISCUSSION
NWS TAUNTON MA
659 AM EDT WED SEP 10 2014
.SYNOPSIS...
WEAK LOW PRESSURE PASSING SE OF NEW ENGLAND MAY BRING A FEW
SHOWERS TO THE ISLANDS TODAY...OTHERWISE DRY WEATHER WILL PREVAIL.
A COLD FRONT WILL SWING ACROSS THE REGION LATE THURSDAY AND EARLY
FRIDAY...THEN STALL JUST OFFSHORE. A DISTURBANCE MOVING ALONG THIS
FRONT SATURDAY MAY COME CLOSE ENOUGH TO RESULT IN SHOWERS. HIGH
PRESSURE RETURNS WITH DRY AND COOLER WEATHER SUNDAY INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
700 AM UPDATE...
OVERALL TREND IN THE FORECAST REMAINS ON TRACK. HAVE MADE MINOR
UPDATES TO ACCOUNT FOR CURRENT CONDITIONS. A FEW SPRINKLES MAY
REACH ACK THIS MORNING. OTHERWISE EAST/NORTHEAST FLOW HAS ALLOWED
FOR LOW STRATUS AND PATCHY FOG...ESP ALONG THE NORTH SHORE WHERE
WIND SPEEDS ARE LESS. ANTICIPATE BOTH CLOUDS AND FOG TO LIFT
DURING THE MORNING HOURS.
PREVIOUS DISCUSSION....
MAIN BATCH OF SHOWERS REMAINS SE OF NANTUCKET AND EXPECT MOST OF
IT TO REMAIN OFFSHORE TODAY. MODELS SEEM TO BE STRUGGLING WITH HOW
CLOSE THESE SHOWERS GET TO SE NEW ENGLAND...BUT HRRR LOOKS
REASONABLE IN GRAZING NANTUCKET THROUGH MID MORNING. DRY AIR AT
MID LEVELS PER 00Z CHATHAM SOUNDING WILL PREVENT MUCH OF THIS FROM
REACHING GROUND...IN FACT WE MAY JUST END UP WITH FEW SPRINKLES ON
ISLANDS AND OUTER CAPE.
LOW CLOUDS AND PATCHY FOG WILL PREVAIL ELSEWHERE THROUGH DAYBREAK
DUE TO LIGHT ONSHORE FLOW...BUT WILL BREAK AFTER SUNRISE AND GIVE
WAY TO PARTLY TO MOSTLY SUNNY SKIES.
CONTINUED ONSHORE FLOW WILL KEEP HIGHS NEAR AVERAGE FOR MOST
PART...MAINLY IN 70S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
EXPECT A RETURN OF LOW CLOUDS/FOG TONIGHT WHICH SHOULD BE MORE
WIDESPREAD AS LOWER LEVELS MOISTEN WITH E/SE FLOW. MAY SEE AREAS
OF DENSE FOG ALONG IMMEDIATE COAST. OTHERWISE SURFACE RIDGE KEEPS
US DRY ASIDE FROM SPOTTY DRIZZLE.
COLD FRONT APPROACHES NEW ENGLAND THU BUT SHOULD REMAIN TO OUR W.
FLOW TURNS MORE S/SW IN ADVANCE OF FRONT WHICH WILL HELP SCOUR OUT
LOW CLOUDS/FOG IN THE MORNING...EXCEPT AROUND S COAST...CAPE COD
AND ISLANDS WHERE IT MAY PERSIST INTO AFTERNOON.
INSTABILITY LOOKS MARGINAL AND MID LEVEL LAPSE RATES ARE WEAK...
BUT ENOUGH TO INCLUDE MENTION OF THUNDER AHEAD OF FRONT. BETTER
CHANCES ACROSS INTERIOR WHERE S FLOW OFF OCEAN IS LESS OF
STABILIZING FACTOR. MODELS CONTINUE TO SHOW PLENTY OF MOISTURE
AVAILABLE WITH PRECIPITABLE WATER VALUES NEAR 2 INCHES /+2 TO +3
STANDARD DEVIATION/...SO LOCALLY HEAVY RAINFALL CAN BE EXPECTED.
HIGHS SHOULD REACH 70S AND LOWER 80S...AND IT WILL FEEL MORE
SUMMERLIKE AS DEWPOINTS CLIMB WELL INTO 60S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
HIGHLIGHTS...
* SCATTERED SHOWERS/ISOLATED T-STORMS THU PM INTO EARLY FRI
* SLIGHT CHANGE FOR SHOWERS SAT PM/SUN
* A TASTE OF AUTUMN TEMPERATURES NEXT WEEK
OVERVIEW...
LATEST MODEL AND ENSEMBLE GUIDANCE OVERALL SEEMS TO OFFER FAIRLY
REASONABLE LARGER SCALE PATTERN EVOLUTION CONTINUITY. AN AMPLIFYING
ERN PAC TROUGH AND WEST COAST RIDGE DRIFTING INTO WRN NOAM WILL
SUPPORT MEAN MID-UPPER LEVEL TROUGHING OVER THE ERN HALF OF NOAM.
THIS PATTERN...MORE TYPICAL OF THE COLD SEASON THAN LATE SUMMER OR
EARLY FALL...SHOULD YIELD BELOW TO MUCH BELOW NORMAL TEMPS OVER MOST
OF THE ERN 2/3 OF THE CONUS. HOWEVER...DETERMINISTIC MODEL RUNS
FEATURE TOO MUCH INCONSISTENCY.
SEVERAL RIPPLES WILL MOVE THROUGH THE FLOW THROUGH THE PERIOD WITH
THE FIRST ONE BRINGING A COLD FRONT ON THURSDAY NIGHT/FRI MORNING.
ANOTHER SHORTWAVE WILL PASS SAT/SAT NIGHT. THIS ONE CAUSES MORE
UNCERTAINTY AS THE GFS IS HAVING CONVECTIVE FEEDBACK AND IS CREATING
A 1-2 INCH BULLS-EYE OVER THE REGION...IN RETROSPECT THE EC IS
PRODUCING VERY LIGHT QPF. LASTLY ANOTHER WAVE WILL MOVE TROUGH THE
FLOW MONDAY NIGHT/TUESDAY.
OVERALL HAVE MODERATE CONFIDENCE IN THE FORECAST AS THERE IS TO MUCH
SPREAD BETWEEN THE DETERMINISTIC AND ENSEMBLE FORECASTS ESP IN
SPECIFIC DETAILS IN THE FORECAST.
DETAILS...
THURSDAY NIGHT INTO FRIDAY...
THE FOCUS IS ON A STRONG COLD FRONT THAT WILL PUSH ACROSS THE REGION
THURSDAY NIGHT INTO FRIDAY MORNING. BOTH DETERMINISTIC AND ENSEMBLES
KEEP THE INSTABILITY VALUES VERY LOW BUT BECAUSE OF THE STRENGTH OF
THIS FRONT HAVE KEPT ISO MENTIONING OF THUNDER FOR THURSDAY. TIMED
THE THUNDER POTENTIAL WITH THE BETTER K-VALUES AND LI. PRECIPITABLE
WATERS INCREASE CONSIDERABLY...CLOSE TO 2-3 INCHES...WITH A
STRENGTHENING SOUTHERLY FLOW. SOME OF THESE STORMS MAY PRODUCE HEAVY
RAIN...WITH AN ISOLD FLASH FLOOD THREAT PRIMARILY IN URBANIZED
AREAS. THEREFORE ALSO INCLUDED HEAVY RAIN WORDING FOR ANY
THUNDERSTORM POTENTIAL.
HIGH PRESSURE WILL QUICKLY SWING INTO THE AREA BY FRIDAY ALLOWING
FOR THE DAY TO DRY OUT AND TEMPS TO REACH NEAR NORMAL.
SATURDAY TO SATURDAY NIGHT...
HIGH PRESSURE WILL BEGIN TO LIFT NORTHWARD ALLOWING FOR EASTERLY FLOW
ON SATURDAY. BY THE LATE AFTERNOON/EVENING HOURS A COLD FRONT WILL
PASS THROUGH REGION BRINGING ANOTHER CHANCE OF THUNDERSTORMS. AS
MENTIONED BEFORE...THERE IS SIGNIFICANT DIFFERENCE BETWEEN THE
DETERMINISTIC GUIDANCE WITH THE GFS PRODUCING A 1-2 INCH BULLS-EYE.
WHILE THE EC IS DEVELOPING LIGHT QPF. APPEARS THE GFS IS RECEIVING
CONVECTIVE FEEDBACK BUT BECAUSE BOTH ARE TRENDING TO MOVE
PRECIP...HAVE INCREASED THE POTENTIAL TO CHANCE POP.
SUNDAY INTO NEXT WEEKEND...
A MODIFIED CANADIAN HIGH WILL THEN BUILD IN THROUGH EARLY NEXT WEEK
BEFORE ANOTHER FRONTAL SYSTEM POSSIBLY IMPACTS THE AREA AROUND
TUES OF NEXT WEEK.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
MODERATE CONFIDENCE THROUGH THU.
AREAS OF MVFR/IFR CIGS/VSBYS THROUGH 12Z WITH BRIEF SHOWER/
SPRINKLE POSSIBLE NEAR NANTUCKET AND VINEYARD. CONDITIONS IMPROVE
TO VFR AFTER 12Z FROM W TO E BUT MVFR CIGS MAY LINGER INTO EARLY
AFTERNOON.
CIGS/VSBYS LOWER AGAIN TONIGHT DUE TO PERSISTENT ONSHORE FLOW...
THIS TIME TO IFR/LIFR ACROSS MUCH OF REGION. CONDITIONS SLOWLY
IMPROVE TO VFR AGAIN THU MORNING...LAST ACROSS CAPE COD AND
ISLANDS THU AFTERNOON...BUT SCATTERED SHOWERS/THUNDERSTORMS
POSSIBLE ACROSS INTERIOR AFTER 18Z. MAY REACH BOS/PVD BY 22Z.
KBOS TERMINAL...HIGH CONFIDENCE IN TRENDS BUT LOWER CONFIDENCE ON
EXACT TIMING.
KBDL TERMINAL...HIGH CONFIDENCE IN TRENDS BUT LOWER CONFIDENCE ON
EXACT TIMING.
OUTLOOK...FRIDAY THROUGH SUNDAY...MODERATE CONFIDENCE.
FRIDAY...A PERIOD OF MVFR/IFR CONDITIONS POSSIBLE EARLY FRIDAY IN
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS AS A COLD FRONT SWEEPS
THROUGH. OTHERWISE...VFR CONDITIONS EXPECTED FOR A GOOD PORTION
OF THIS PERIOD.
SATURDAY...LOW CONFIDENCE. MAINLY VFR. ONSHORE FLOW COULD ALSO
RESULT IN IFR STRATUS AND FOG ACROSS PORTIONS OF THE EAST
COAST...PARTICULARLY CAPE COD AND THE ISLANDS.
SUNDAY...MODERATE CONFIDENCE. MAINLY VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE THROUGH THU.
SCA REMAINS POSTED FOR OUTER WATERS MAINLY DUE TO 5-6 FT SEAS
TODAY THROUGH THU.
E/NE WINDS GRADUALLY SUBSIDE TODAY AS LOW PRESSURE PASSES WELL SE
OF NEW ENGLAND...THEN S/SW WINDS DEVELOP THU AS COLD FRONT
APPROACHES FROM GREAT LAKES. MAIN CONCERN IS PATCHY DENSE FOG
TONIGHT INTO THU...ESPECIALLY ON S COASTAL WATERS.
OUTLOOK...FRIDAY THROUGH SUNDAY...MODERATE CONFIDENCE.
FRIDAY...MODERATE CONFIDENCE. A ROUND OF SCATTERED SHOWERS AND
PERHAPS ISOLATED THUNDERSTORMS ARE EXPECTED EARLY FRIDAY MORNING
AS A COLD FRONT PASSES THROUGH. WINDS WILL MAY REACH ABOVE 25 KT
BEHIND THIS FRONT ALLOWING FOR SEAS TO APPROACH 5 FT AT TIMES
ACROSS THE OUTER COASTAL WATERS. SMALL CRAFT ADVISORIES MAY BE
NEEDED.
SATURDAY...LOW CONFIDENCE. TIGHTENING PRESSURE GRADIENT AND
APPROACHING COLD FRONT WILL HELP KEEP SEAS AND WINDS UP ON
SATURDAY. SMALL CRAFT ADV MAY BE NEEDED.
SUNDAY...STRONG COLD FRONT WILL PASS OVER THE WATERS IN THE
MORNING. COLD AIR ALOFT WILL INCREASE SEAS AND WIND GUSTS ON
SUNDAY LEADING TO THE POTENTIAL OF A SMALL CRAFT ADV.
&&
.TIDES/COASTAL FLOODING...
LAST HIGH TIDE JUST BEFORE MIDNIGHT PRODUCED 0.2 FT SURGE ALONG E
MA COAST. SUBSEQUENT HIGH TIDES TODAY INTO THU ARE A BIT LOWER AND
SURGE WILL BE MINIMAL...THEREFORE NO IMPACT IS EXPECTED.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ250-
254>256.
&&
$$
SYNOPSIS...DUNTEN/JWD
NEAR TERM...DUNTEN/JWD
SHORT TERM...JWD
LONG TERM...DUNTEN
AVIATION...DUNTEN/JWD
MARINE...DUNTEN/JWD
TIDES/COASTAL FLOODING...JWD
AREA FORECAST DISCUSSION
NWS TAUNTON MA
401 AM EDT WED SEP 10 2014
.SYNOPSIS...
WEAK LOW PRESSURE PASSING SE OF NEW ENGLAND MAY BRING A FEW
SHOWERS TO THE ISLANDS TODAY...OTHERWISE DRY WEATHER WILL PREVAIL
TODAY. A COLD FRONT WILL SWING ACROSS THE REGION LATE THURSDAY
AND EARLY FRIDAY...THEN STALL JUST OFFSHORE. A DISTURBANCE MOVING
ALONG THIS FRONT SATURDAY MAY COME CLOSE ENOUGH TO RESULT IN
SHOWERS. HIGH PRESSURE RETURNS WITH DRY AND COOLER WEATHER SUNDAY
INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
320 AM UPDATE...
MAIN BATCH OF SHOWERS REMAINS SE OF NANTUCKET AND EXPECT MOST OF
IT TO REMAIN OFFSHORE TODAY. MODELS SEEM TO BE STRUGGLING WITH HOW
CLOSE THESE SHOWERS GET TO SE NEW ENGLAND...BUT HRRR LOOKS
REASONABLE IN GRAZING NANTUCKET THROUGH MID MORNING. DRY AIR AT
MID LEVELS PER 00Z CHATHAM SOUNDING WILL PREVENT MUCH OF THIS FROM
REACHING GROUND...IN FACT WE MAY JUST END UP WITH FEW SPRINKLES ON
ISLANDS AND OUTER CAPE.
LOW CLOUDS AND PATCHY FOG WILL PREVAIL ELSEWHERE THROUGH DAYBREAK
DUE TO LIGHT ONSHORE FLOW...BUT WILL BREAK AFTER SUNRISE AND GIVE
WAY TO PARTLY TO MOSTLY SUNNY SKIES.
CONTINUED ONSHORE FLOW WILL KEEP HIGHS NEAR AVERAGE FOR MOST
PART...MAINLY IN 70S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
EXPECT A RETURN OF LOW CLOUDS/FOG TONIGHT WHICH SHOULD BE MORE
WIDESPREAD AS LOWER LEVELS MOISTEN WITH E/SE FLOW. MAY SEE AREAS
OF DENSE FOG ALONG IMMEDIATE COAST. OTHERWISE SURFACE RIDGE KEEPS
US DRY ASIDE FROM SPOTTY DRIZZLE.
COLD FRONT APPROACHES NEW ENGLAND THU BUT SHOULD REMAIN TO OUR W.
FLOW TURNS MORE S/SW IN ADVANCE OF FRONT WHICH WILL HELP SCOUR OUT
LOW CLOUDS/FOG IN THE MORNING...EXCEPT AROUND S COAST...CAPE COD
AND ISLANDS WHERE IT MAY PERSIST INTO AFTERNOON.
INSTABILITY LOOKS MARGINAL AND MID LEVEL LAPSE RATES ARE WEAK...
BUT ENOUGH TO INCLUDE MENTION OF THUNDER AHEAD OF FRONT. BETTER
CHANCES ACROSS INTERIOR WHERE S FLOW OFF OCEAN IS LESS OF
STABILIZING FACTOR. MODELS CONTINUE TO SHOW PLENTY OF MOISTURE
AVAILABLE WITH PRECIPITABLE WATER VALUES NEAR 2 INCHES /+2 TO +3
STANDARD DEVIATION/...SO LOCALLY HEAVY RAINFALL CAN BE EXPECTED.
HIGHS SHOULD REACH 70S AND LOWER 80S...AND IT WILL FEEL MORE
SUMMERLIKE AS DEWPOINTS CLIMB WELL INTO 60S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
HIGHLIGHTS...
* SCATTERED SHOWERS/ISOLATED T-STORMS THU PM INTO EARLY FRI
* SLIGHT CHANGE FOR SHOWERS SAT PM/SUN
* A TASTE OF AUTUMN TEMPERATURES NEXT WEEK
OVERVIEW...
LATEST MODEL AND ENSEMBLE GUIDANCE OVERALL SEEMS TO OFFER FAIRLY
REASONABLE LARGER SCALE PATTERN EVOLUTION CONTINUITY. AN AMPLIFYING
ERN PAC TROUGH AND WEST COAST RIDGE DRIFTING INTO WRN NOAM WILL
SUPPORT MEAN MID-UPPER LEVEL TROUGHING OVER THE ERN HALF OF NOAM.
THIS PATTERN...MORE TYPICAL OF THE COLD SEASON THAN LATE SUMMER OR
EARLY FALL...SHOULD YIELD BELOW TO MUCH BELOW NORMAL TEMPS OVER MOST
OF THE ERN 2/3 OF THE CONUS. HOWEVER...DETERMINISTIC MODEL RUNS
FEATURE TOO MUCH INCONSISTENCY.
SEVERAL RIPPLES WILL MOVE THROUGH THE FLOW THROUGH THE PERIOD WITH
THE FIRST ONE BRINGING A COLD FRONT ON THURSDAY NIGHT/FRI MORNING.
ANOTHER SHORTWAVE WILL PASS SAT/SAT NIGHT. THIS ONE CAUSES MORE
UNCERTAINTY AS THE GFS IS HAVING CONVECTIVE FEEDBACK AND IS CREATING
A 1-2 INCH BULLS-EYE OVER THE REGION...IN RETROSPECT THE EC IS
PRODUCING VERY LIGHT QPF. LASTLY ANOTHER WAVE WILL MOVE TROUGH THE
FLOW MONDAY NIGHT/TUESDAY.
OVERALL HAVE MODERATE CONFIDENCE IN THE FORECAST AS THERE IS TO MUCH
SPREAD BETWEEN THE DETERMINISTIC AND ENSEMBLE FORECASTS ESP IN
SPECIFIC DETAILS IN THE FORECAST.
DETAILS...
THURSDAY NIGHT INTO FRIDAY...
THE FOCUS IS ON A STRONG COLD FRONT THAT WILL PUSH ACROSS THE REGION
THURSDAY NIGHT INTO FRIDAY MORNING. BOTH DETERMINISTIC AND ENSEMBLES
KEEP THE INSTABILITY VALUES VERY LOW BUT BECAUSE OF THE STRENGTH OF
THIS FRONT HAVE KEPT ISO MENTIONING OF THUNDER FOR THURSDAY. TIMED
THE THUNDER POTENTIAL WITH THE BETTER K-VALUES AND LI. PRECIPITABLE
WATERS INCREASE CONSIDERABLY...CLOSE TO 2-3 INCHES...WITH A
STRENGTHENING SOUTHERLY FLOW. SOME OF THESE STORMS MAY PRODUCE HEAVY
RAIN...WITH AN ISOLD FLASH FLOOD THREAT PRIMARILY IN URBANIZED
AREAS. THEREFORE ALSO INCLUDED HEAVY RAIN WORDING FOR ANY
THUNDERSTORM POTENTIAL.
HIGH PRESSURE WILL QUICKLY SWING INTO THE AREA BY FRIDAY ALLOWING
FOR THE DAY TO DRY OUT AND TEMPS TO REACH NEAR NORMAL.
SATURDAY TO SATURDAY NIGHT...
HIGH PRESSURE WILL BEGIN TO LIFT NORTHWARD ALLOWING FOR EASTERLY FLOW
ON SATURDAY. BY THE LATE AFTERNOON/EVENING HOURS A COLD FRONT WILL
PASS THROUGH REGION BRINGING ANOTHER CHANCE OF THUNDERSTORMS. AS
MENTIONED BEFORE...THERE IS SIGNIFICANT DIFFERENCE BETWEEN THE
DETERMINISTIC GUIDANCE WITH THE GFS PRODUCING A 1-2 INCH BULLS-EYE.
WHILE THE EC IS DEVELOPING LIGHT QPF. APPEARS THE GFS IS RECEIVING
CONVECTIVE FEEDBACK BUT BECAUSE BOTH ARE TRENDING TO MOVE
PRECIP...HAVE INCREASED THE POTENTIAL TO CHANCE POP.
SUNDAY INTO NEXT WEEKEND...
A MODIFIED CANADIAN HIGH WILL THEN BUILD IN THROUGH EARLY NEXT WEEK
BEFORE ANOTHER FRONTAL SYSTEM POSSIBLY IMPACTS THE AREA AROUND
TUES OF NEXT WEEK.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
MODERATE CONFIDENCE THROUGH THU.
AREAS OF MVFR/IFR CIGS/VSBYS THROUGH 12Z WITH BRIEF SHOWER/
SPRINKLE POSSIBLE NEAR NANTUCKET AND VINEYARD. CONDITIONS IMPROVE
TO VFR AFTER 12Z FROM W TO E BUT MVFR CIGS MAY LINGER INTO EARLY
AFTERNOON NEAR S COAST...CAPE COD AND ISLANDS.
CIGS/VSBYS LOWER AGAIN TONIGHT DUE TO PERSISTENT ONSHORE FLOW...
THIS TIME TO IFR/LIFR ACROSS MUCH OF REGION. CONDITIONS SLOWLY
IMPROVE TO VFR AGAIN THU MORNING...LAST ACROSS CAPE COD AND
ISLANDS THU AFTERNOON...BUT SCATTERED SHOWERS/THUNDERSTORMS
POSSIBLE ACROSS INTERIOR AFTER 18Z. MAY REACH BOS/PVD BY 22Z.
KBOS TERMINAL...HIGH CONFIDENCE IN TRENDS BUT LOWER CONFIDENCE ON
EXACT TIMING.
KBDL TERMINAL...HIGH CONFIDENCE IN TRENDS BUT LOWER CONFIDENCE ON
EXACT TIMING.
OUTLOOK...FRIDAY THROUGH SUNDAY...MODERATE CONFIDENCE.
FRIDAY...A PERIOD OF MVFR/IFR CONDITIONS POSSIBLE EARLY FRIDAY IN
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS AS A COLD FRONT SWEEPS
THROUGH. OTHERWISE...VFR CONDITIONS EXPECTED FOR A GOOD PORTION
OF THIS PERIOD.
SATURDAY...LOW CONFIDENCE. MAINLY VFR. ONSHORE FLOW COULD ALSO
RESULT IN IFR STRATUS AND FOG ACROSS PORTIONS OF THE EAST
COAST...PARTICULARLY CAPE COD AND THE ISLANDS.
SUNDAY...MODERATE CONFIDENCE. MAINLY VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE THROUGH THU.
SCA REMAINS POSTED FOR OUTER WATERS MAINLY DUE TO 5-6 FT SEAS
TODAY THROUGH THU.
E/NE WINDS GRADUALLY SUBSIDE TODAY AS LOW PRESSURE PASSES WELL SE
OF NEW ENGLAND...THEN S/SW WINDS DEVELOP THU AS COLD FRONT
APPROACHES FROM GREAT LAKES. MAIN CONCERN IS PATCHY DENSE FOG
TONIGHT INTO THU...ESPECIALLY ON S COASTAL WATERS.
OUTLOOK...FRIDAY THROUGH SUNDAY...MODERATE CONFIDENCE.
FRIDAY...MODERATE CONFIDENCE. A ROUND OF SCATTERED SHOWERS AND
PERHAPS ISOLATED THUNDERSTORMS ARE EXPECTED EARLY FRIDAY MORNING
AS A COLD FRONT PASSES THROUGH. WINDS WILL MAY REACH ABOVE 25 KT
BEHIND THIS FRONT ALLOWING FOR SEAS TO APPROACH 5 FT AT TIMES
ACROSS THE OUTER COASTAL WATERS. SMALL CRAFT ADVISORIES MAY BE
NEEDED.
SATURDAY...LOW CONFIDENCE. TIGHTENING PRESSURE GRADIENT AND
APPROACHING COLD FRONT WILL HELP KEEP SEAS AND WINDS UP ON
SATURDAY. SMALL CRAFT ADV MAY BE NEEDED.
SUNDAY...STRONG COLD FRONT WILL PASS OVER THE WATERS IN THE
MORNING. COLD AIR ALOFT WILL INCREASE SEAS AND WIND GUSTS ON
SUNDAY LEADING TO THE POTENTIAL OF A SMALL CRAFT ADV.
&&
.TIDES/COASTAL FLOODING...
LAST HIGH TIDE JUST BEFORE MIDNIGHT PRODUCED 0.2 FT SURGE ALONG E
MA COAST. SUBSEQUENT HIGH TIDES TODAY INTO THU ARE A BIT LOWER AND
SURGE WILL BE MINIMAL...THEREFORE NO IMPACT IS EXPECTED.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ250-
254>256.
&&
$$
SYNOPSIS...DUNTEN/JWD
NEAR TERM...JWD
SHORT TERM...JWD
LONG TERM...DUNTEN
AVIATION...DUNTEN/JWD
MARINE...DUNTEN/JWD
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS TAUNTON MA
321 AM EDT WED SEP 10 2014
.SYNOPSIS...
WEAK LOW PRESSURE PASSING SE OF NEW ENGLAND MAY BRING A FEW
SHOWERS TO THE ISLANDS TODAY...OTHERWISE DRY WEATHER WILL PREVAIL
TODAY. A COLD FRONT WILL SWING ACROSS THE REGION LATE THURSDAY
AND EARLY FRIDAY...THEN STALL JUST OFFSHORE. A DISTURBANCE MOVING
ALONG THIS FRONT SATURDAY MAY COME CLOSE ENOUGH TO RESULT IN
SHOWERS. HIGH PRESSURE RETURNS WITH DRY AND COOLER WEATHER SUNDAY
INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
320 AM UPDATE...
MAIN BATCH OF SHOWERS REMAINS SE OF NANTUCKET AND EXPECT MOST OF
IT TO REMAIN OFFSHORE TODAY. MODELS SEEM TO BE STRUGGLING WITH HOW
CLOSE THESE SHOWERS GET TO SE NEW ENGLAND...BUT HRRR LOOKS
REASONABLE IN GRAZING NANTUCKET THROUGH MID MORNING. DRY AIR AT
MID LEVELS PER 00Z CHATHAM SOUNDING WILL PREVENT MUCH OF THIS FROM
REACHING GROUND...IN FACT WE MAY JUST END UP WITH FEW SPRINKLES ON
ISLANDS AND OUTER CAPE.
LOW CLOUDS AND PATCHY FOG WILL PREVAIL ELSEWHERE THROUGH DAYBREAK
DUE TO LIGHT ONSHORE FLOW...BUT WILL BREAK AFTER SUNRISE AND GIVE
WAY TO PARTLY TO MOSTLY SUNNY SKIES.
CONTINUED ONSHORE FLOW WILL KEEP HIGHS NEAR AVERAGE FOR MOST
PART...MAINLY IN 70S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
EXPECT A RETURN OF LOW CLOUDS/FOG TONIGHT WHICH SHOULD BE MORE
WIDESPREAD AS LOWER LEVELS MOISTEN WITH E/SE FLOW. MAY SEE AREAS
OF DENSE FOG ALONG IMMEDIATE COAST. OTHERWISE SURFACE RIDGE KEEPS
US DRY ASIDE FROM SPOTTY DRIZZLE.
COLD FRONT APPROACHES NEW ENGLAND THU BUT SHOULD REMAIN TO OUR W.
FLOW TURNS MORE S/SW IN ADVANCE OF FRONT WHICH WILL HELP SCOUR OUT
LOW CLOUDS/FOG IN THE MORNING...EXCEPT AROUND S COAST...CAPE COD
AND ISLANDS WHERE IT MAY PERSIST INTO AFTERNOON.
INSTABILITY LOOKS MARGINAL AND MID LEVEL LAPSE RATES ARE WEAK...
BUT ENOUGH TO INCLUDE MENTION OF THUNDER AHEAD OF FRONT. BETTER
CHANCES ACROSS INTERIOR WHERE S FLOW OFF OCEAN IS LESS OF
STABILIZING FACTOR. MODELS CONTINUE TO SHOW PLENTY OF MOISTURE
AVAILABLE WITH PRECIPITABLE WATER VALUES NEAR 2 INCHES /+2 TO +3
STANDARD DEVIATION/...SO LOCALLY HEAVY RAINFALL CAN BE EXPECTED.
HIGHS SHOULD REACH 70S AND LOWER 80S...AND IT WILL FEEL MORE
SUMMERLIKE AS DEWPOINTS CLIMB WELL INTO 60S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
HIGHLIGHTS...
* SCATTERED SHOWERS/ISOLATED T-STORMS THU PM INTO EARLY FRI
* SLIGHT CHANGE FOR SHOWERS SAT PM/SUN
* A TASTE OF AUTUMN TEMPERATURES NEXT WEEK
OVERVIEW...
BUILDING UPPER RIDGE OVER THE NE PACIFIC AND WESTERN CANADA...AS
WELL AS MORE MODEST RIDGING OVER THE MARITIMES...WILL SUPPORT
DEEP TROUGHING OVER THE CENTRAL CONUS LATE THIS WEEK. THIS DEEP
TROUGH WILL PUSH A FRONT THROUGH OUR REGION BY LATE THU INTO FRI.
OVERALL THE LONGWAVE PREDICTABILITY REMAINS BETTER THAN AVERAGE
DESPITE THIS AMPLIFIED PATTERN. HOWEVER...DETERMINISTIC MODELS
STILL FEATURE TOO MUCH INCONSISTENCY FROM RUN TO RUN TO BE CERTAIN
OF THE DETAILS.
THOUGH THE INITIAL TROUGH LIFTS THROUGH THE GREAT LAKES AND
NORTHEAST INTO SOUTHEAST CANADA THIS WEEKEND...ENSEMBLES STILL
SUPPORT THE POSSIBILITY OF A MORE PERSISTENT LONGWAVE RIDGE/TROUGH
PATTERN....WITH SOUTHERN NEW ENGLAND CONTENDING MORE WITH A MID
LEVEL TROUGH. THE MAIN QUESTION REMAINS HOW WAVY AND CLOSE TO THE
COAST A COLD FRONT WILL REMAIN FRIDAY INTO SATURDAY. THIS WILL
ULTIMATELY DETERMINE THE AMOUNT/LOCATION OF ADDITIONAL/OVERRUNNING
PRECIPITATION. ENSEMBLE MEANS SUGGEST THE MAIN AXIS TO REMAIN JUST
OFFSHORE...BUT A CLOSER POSITION IN SOME OF THE INDIVIDUAL MEMBERS
SEEMS MORE CONSISTENT WITH SUCH AN AMPLIFIED PATTERN ALOFT. CONTINUE
TO BE ON THE OPTIMISTIC SIDE AND KEPT A PORTION OF THIS WEEKEND DRY
FOR NOW...MAINLY SUNDAY.
OVERALL HAVE MODERATE CONFIDENCE IN THE FORECAST AS THERE IS TOO
MUCH SPREAD BETWEEN THE DETERMINISTIC AND ENSEMBLE FORECASTS.
DETAILS...
THURSDAY INTO FRIDAY...
FOCUS IS ON A STRONG COLD FRONT THAT WILL PUSH ACROSS THE REGION
SOMETIME THURSDAY INTO FRIDAY. BOTH DETERMINISTIC AND ENSEMBLES KEEP
INSTABILITY VERY LOW. THERE IS DECENT SHEAR IN THE LOWER LEVELS
THOUGH. BECAUSE OF THE STRENGTH OF THIS FRONT AND THE SHEAR...KEPT A
MENTION OF ISOLATED TO SCATTERED THUNDERSTORMS IN THE FORECAST.
THERE COULD BE SOME HEAVY RAIN WITH THIS FRONT...BUT THE BEST
DYNAMICS AND CONDITIONS WILL BE TO THE WEST OF OUR REGION. THIS
FRONT WILL MAINLY PUSH THROUGH OVERNIGHT THURSDAY...THEN MOVE
FARTHER OFFSHORE FRIDAY MORNING. ALTHOUGH THERE IS STILL SOME
UNCERTAINTY ON TIMING AND HOW FAR OFFSHORE THIS FRONT WILL GO.
THIS WEEKEND...
ONCE AGAIN THIS FORECAST IS DEPENDENT ON HOW FAR OFFSHORE THE FRONT
WILL GET TOO. 09/12Z GUIDANCE KEEPS THE FRONT FAR ENOUGH
OFFSHORE...ALLOWING FOR A PORTION OF THIS WEEKEND TO BE DRY.
HOWEVER MOST OF THE 09/12Z GUIDANCE ALSO SWINGS A WEAK COLD FRONT
THROUGH THE GREAT LAKES INTO SOUTHERN NEW ENGLAND LATE SATURDAY
INTO SATURDAY NIGHT. THIS COULD POTENTIALLY PRODUCE SOME LIGHT
RAINFALL DURING THIS TIME. ONE THING TO WATCH IS THE CONTINUOUS
EASTERLY FLOW OFF THE WATERS. THIS MAY KEEP FOG/LOW CLOUDS ACROSS
THE EASTERN HALF OF THE REGION. THIS FORECAST IS STILL SEVERAL
DAYS OUT...SO WILL CONTINUE TO FINE TUNE IT AS THIS WEEK
PROGRESSES.
EARLY NEXT WEEK...
HIGH PRESSURE ARRIVES WITH A FALL-LIKE AIRMASS. 09/12Z GFS IS MUCH
MORE AGGRESSIVE THAN THE ECMWF IN SWINGING A MID LEVEL SHORTWAVE
THROUGH OUR REGION SOMETIME MONDAY INTO TUESDAY. BASED ON THE
PATTERN THOUGH...AM THINKING MOSTLY DRY WEATHER WITH JUST AN
INCREASE IN CLOUDS AT THIS TIME.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
MODERATE CONFIDENCE THROUGH THU.
AREAS OF MVFR/IFR CIGS/VSBYS THROUGH 12Z WITH BRIEF SHOWER/
SPRINKLE POSSIBLE NEAR NANTUCKET AND VINEYARD. CONDITIONS IMPROVE
TO VFR AFTER 12Z FROM W TO E BUT MVFR CIGS MAY LINGER INTO EARLY
AFTERNOON NEAR S COAST...CAPE COD AND ISLANDS.
CIGS/VSBYS LOWER AGAIN TONIGHT DUE TO PERSISTENT ONSHORE FLOW...
THIS TIME TO IFR/LIFR ACROSS MUCH OF REGION. CONDITIONS SLOWLY
IMPROVE TO VFR AGAIN THU MORNING...LAST ACROSS CAPE COD AND
ISLANDS THU AFTERNOON...BUT SCATTERED SHOWERS/THUNDERSTORMS
POSSIBLE ACROSS INTERIOR AFTER 18Z. MAY REACH BOS/PVD BY 22Z.
KBOS TERMINAL...HIGH CONFIDENCE IN TRENDS BUT LOWER CONFIDENCE ON
EXACT TIMING.
KBDL TERMINAL...HIGH CONFIDENCE IN TRENDS BUT LOWER CONFIDENCE ON
EXACT TIMING.
OUTLOOK...FRIDAY THROUGH SUNDAY...MODERATE CONFIDENCE.
FRIDAY...A PERIOD OF MVFR/IFR CONDITIONS POSSIBLE EARLY FRIDAY IN
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS AS A COLD FRONT SWEEPS
THROUGH. THERE MAY ALSO BE SOME LOWER CLOUDS AND FOG PATCHES AT
TIMES. OTHERWISE...VFR CONDITIONS EXPECTED FOR A GOOD PORTION OF
THIS PERIOD.
SATURDAY...LOW CONFIDENCE. MAINLY VFR. ONSHORE FLOW COULD ALSO
RESULT IN IFR STRATUS AND FOG ACROSS PORTIONS OF THE EAST
COAST...PARTICULARLY CAPE COD AND THE ISLANDS.
SUNDAY...MODERATE CONFIDENCE. MAINLY VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE THROUGH THU.
SCA REMAINS POSTED FOR OUTER WATERS MAINLY DUE TO 5-6 FT SEAS
TODAY THROUGH THU.
E/NE WINDS GRADUALLY SUBSIDE TODAY AS LOW PRESSURE PASSES WELL SE
OF NEW ENGLAND...THEN S/SW WINDS DEVELOP THU AS COLD FRONT
APPROACHES FROM GREAT LAKES. MAIN CONCERN IS PATCHY DENSE FOG
TONIGHT INTO THU...ESPECIALLY ON S COASTAL WATERS.
OUTLOOK...FRIDAY THROUGH SUNDAY...MODERATE CONFIDENCE.
FRIDAY...MODERATE CONFIDENCE. WINDS WILL MAY REACH ABOVE 25 KT
BEHIND COLD FRONT. A ROUND OF SCATTERED SHOWERS AND PERHAPS
ISOLATED THUNDERSTORMS ARE EXPECTED THURSDAY NIGHT INTO EARLY
FRIDAY. SEAS COULD APPROACH 5 FT AT TIMES ACROSS THE OUTER COASTAL
WATERS. SMALL CRAFT ADVISORIES MAY BE NEEDED.
SATURDAY...LOW CONFIDENCE. SEAS SHOULD SUBSIDE BELOW 5 FT AND
EASTERLY WINDS SHOULD DIMINISH BELOW 20 KTS.
SUNDAY...RELATIVELY TRANQUIL WINDS AND SEAS EXPECTED.
OUTLOOK...THURSDAY THROUGH SUNDAY...MODERATE CONFIDENCE.
THURSDAY AND FRIDAY...MODERATE CONFIDENCE. EASTERLY FLOW SWITCHES TO
THE SOUTHWEST AHEAD OF AN APPROACHING COLD FRONT. WINDS WILL MAY
REACH ABOVE 25 KT ON THE BACKSIDE OF THIS FRONT. A ROUND OF
SCATTERED SHOWERS AND PERHAPS ISOLATED THUNDERSTORMS ARE EXPECTED
LATE THURSDAY INTO EARLY FRIDAY. SEAS COULD APPROACH 5 FT AT TIMES
ACROSS THE OUTER COASTAL WATERS. SMALL CRAFT ADVISORIES MAY BE
NEEDED.
SATURDAY...LOW CONFIDENCE. SEAS SHOULD SUBSIDE BELOW 5 FT AND
EASTERLY WINDS SHOULD DIMINISH BELOW 20 KTS.
SUNDAY...RELATIVELY TRANQUIL WINDS AND SEAS EXPECTED.
&&
.TIDES/COASTAL FLOODING...
LAST HIGH TIDE JUST BEFORE MIDNIGHT PRODUCED 0.2 FT SURGE ALONG E
MA COAST. SUBSEQUENT HIGH TIDES TODAY INTO THU ARE A BIT LOWER AND
SURGE WILL BE MINIMAL...THEREFORE NO IMPACT IS EXPECTED.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ250-
254>256.
&&
$$
SYNOPSIS...DUNTEN/JWD
NEAR TERM...JWD
SHORT TERM...WTB
LONG TERM...BELK
AVIATION...JWD
MARINE...JWD
TIDES/COASTAL FLOODING...JWD
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
855 PM EDT THU SEP 11 2014
.UPDATE (REST OF TONIGHT)...
01Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUES TO SHOW THE NORTHERN
STREAM DIPPING DOWN INTO THE NORTH-CENTRAL PORTION OF THE CONUS WITH
A FALL TYPE AIRMASS NOW FIRMLY ENTRENCHED. THE TRANSITION ZONE LIES
ACROSS THE CENTER OF THE NATION FROM THE CENTRAL PLAINS TO THE TN
VALLEY AND MID-ATLANTIC COAST...WITH AN ELONGATED UPPER LEVEL RIDGE
FURTHER SOUTH OVER THE NORTHERN GULF COAST. OUR FORECAST REGION
REMAINS IN A POSITION BETWEEN THIS UPPER RIDGE AND THE WEAK
DISTURBANCE OVER THE BAHAMAS.
AT THE SURFACE...THE GRADIENT IS RATHER "BAGGY" AND ILL-DEFINED IN
NATURE BETWEEN THE SUBTROPICAL RIDGE AXIS STRETCHING WESTWARD INTO
NORTHERN FLORIDA AND THE SUBTLE SURFACE REFLECTION/LOW NEAR THE
NORTHERN BAHAMAS. THIS RESULTS IN A WEAK EASTERLY TO NORTHEASTERLY
COMPONENT TO OUR LOW LEVEL WINDS.
WAS A BUSY EVENING AS THE LOW LEVEL FLOW KEPT THE WEST COAST
SEA-BREEZE PINNED NEAR THE COAST AND ALLOWED FOR A LATE DAY
COLLISION BETWEEN THIS BOUNDARY AND THE EAST COAST SEA-BREEZE.
STORMS ERUPTED ALONG THE CONVERGENCE BOUNDARY BETWEEN 6 AND 7 PM AND
HAVE SINCE PUSHED WEST AND OFF THE COAST. HAVE UPDATED THE FORECAST
GRIDS TO REMOVE RAIN CHANCES FOR ALL BY THE FAR SOUTHERN ZONES. KEPT
A SLIGHT CHANCE FOR A SHOWER OR TWO DOWN TOWARD FORT MYERS WITHIN
THE BETTER MOISTURE ZONE AHEAD OF THE APPROACHING DISTURBANCE.
HOWEVER...BASED ON LATEST RADAR TRENDS...THIS SLIGHT CHANCE MAY BE
ABLE TO BE REMOVED SOON AS WELL.
BASED ON WATER VAPOR IMAGERY...ASSUMING THAT WE HAVE MOISTENED OUR
UPPER LEVELS SOMEWHAT DURING THE DAY SINCE THE 12Z SOUNDING THIS
MORNING. THUNDERSTORMS ERUPTED NEAR THE OFFICE AND DELAYED THE
BALLOON LAUNCH SOMEWHAT...SO DO NOT HAVE THAT DATA IN FRONT OF ME
CURRENTLY. HOWEVER...THE BALLOON IS IN THE AIR...AND THE DATA SHOULD
BECOME AVAILABLE SHORTLY.
SO...IN SUMMARY. A MOSTLY DRY AND SEASONABLE OVERNIGHT EXPECTED FROM
HERE FORWARD. THOSE NEAR THE COAST WILL LIKELY CONTINUE TO SEE THOSE
LIGHTNING FLASHES TO THE EAST FROM THE STORMS THAT ROLLED OFFSHORE
RECENTLY...BUT EVEN THIS ACTIVITY SHOULD SUBSIDE BEFORE MIDNIGHT AS
THE STORMS PUSH FURTHER FROM SHORE AND WEAKEN. HAVE A GREAT NIGHT
EVERYONE!
&&
PREVIOUS DISCUSSION (FRIDAY)...
THE WEAKENING TROPICAL DISTURBANCE AND ASSOCIATED MID LEVEL
VORTICITY CENTER WILL SHIFT OVER SOUTH FLORIDA THROUGH THE
DAY...INCREASING DEEP LAYER MOISTURE AND RESULTING IN A BETTER
CHANCE OF SHOWERS AND THUNDERSTORMS...PARTICULARLY FROM THE TAMPA
BAY AREA SOUTHWARD. SHOWERS/STORMS SHOULD BEGIN TO DEVELOP EARLIER
IN THE DAY...WITH COVERAGE INCREASING ACROSS THE INTERIOR AND
SOUTHWEST FLORIDA NOTICEABLY BETWEEN 11 AM AND 2 PM. AFTER 2
PM...EXPECT NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS SOUTHERN AREAS
WHERE POPS IN THE 70 PERCENT RANGE AROUND FORT MYERS LOOK LIKE A
GOOD BET. COLUMN MOISTURE WILL DECREASE HEADING NORTHWARD...WITH 40
TO 50 PERCENT RAIN CHANCES EXPECTED ACROSS CENTRAL ZONES AND 30
PERCENT FOR FAR NORTHERN AREAS. HIGH TEMPERATURES ARE EXPECTED TO
TOP OUT IN THE UPPER 80S ACROSS SOUTHERN ZONES WHERE MORE CLOUD
COVER AND BETTER SHOWER/THUNDERSTORM COVERAGE WILL EXIST...AND IN
THE LOWER 90S ACROSS CENTRAL AND SOUTHERN ZONES.
&&
.AVIATION...
12/00Z - 13/00Z. HAVE OPTED FOR PREVAILING VFR WITH VCNTY SHRA OR
TSRA UNTIL CONVECTION PUSHES OFFSHORE...02/03Z. GENERALLY BKN
MID-HIGH CLOUDS OVERNIGHT INTO FRI MORNING THEN BKN LOW...BUT STILL
VFR...CLOUDS IN THE AFTERNOON. VCNTY TSRA STARING LATE MORNING SOUTH
AND LATER IN THE AFTERNOON NORTH. LATE DAY SEA BREEZE HAS JUST ABOUT
COLLAPSED...LIGHT AND VARIABLE OVER NIGHT...THEN NE AND EAST FRI.
&&
.MARINE...
A TROPICAL DISTURBANCE FROM THE BAHAMAS WILL MOVE ACROSS SOUTH
FLORIDA AND THEN INTO THE GULF OVER THE NEXT COUPLE OF DAYS. CHANCES
FOR ANY ENHANCED WINDS AND THUNDERSTORMS WILL BE GREATEST SOUTH OF
TAMPA BAY. THE NATIONAL HURRICANE CENTER CURRENTLY HAS A 20 PERCENT
CHANCE OF CYCLONE FORMATION IN THE NEXT TWO DAYS ASSOCIATED WITH
THIS SYSTEM.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 76 92 76 91 / 10 40 20 40
FMY 75 89 73 91 / 20 70 20 60
GIF 74 91 73 92 / 10 40 10 40
SRQ 75 92 75 90 / 20 50 20 50
BKV 71 93 72 92 / 10 40 20 40
SPG 77 91 76 92 / 10 40 20 40
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE...MROCZKA
PREVIOUS DISCUSSION...JELSEMA
MARINE...DOUGHERTY/MROCZKA
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
1005 AM EDT WED SEP 10 2014
.UPDATE...EARLY MORNING RADAR TRENDS SHOW THE CLUSTER OF SHOWERS
AND A FEW STORMS HAVE DECREASED IN COVERAGE AND INTENSITY OVER THE
SE GA COASTAL WATERS AND THE SE GA COASTAL COUNTIES. STILL A FEW
MODERATE SHOWERS NEAR THE BRUNSWICK AREA THAT ARE LIFTING SLOWLY
NWD. SATELLITE AND SFC DATA AND HRRR MODEL SHOW THE TAIL END OF A
FRONTAL BOUNDARY ACROSS THE WRN ATLC THAT EXTENDS WWD TO ABOUT THE
COASTAL SE GA AND TO PERHAPS AROUND WAYCROSS AND THEN DIFFUSE
THEREAFTER INLAND S GA. PATCHY TO AREA OF FOG HAVE DISSIPATED
AFTER SOME VSBY DROPPED TO 1/4 MILE BRIEFLY OVER PORTIONS OF SE GA.
FOR REST OF TODAY...A FEW TWEAKS TO THE FORECAST TO BUMP UP TEMPS
A BIT MORE AND ADJUST POPS. THERE MAY BE SOME ENHANCED PRECIP
POTENTIAL OVER THE NEXT FEW HOURS OVER EXTREME NE FL JUST S OF THE
WEAK FRONTAL BOUNDARY...BUT NO MORE THAN 40% CHANCE FOR NOW FOR
NASSAU AND DUVAL COUNTIES. JUST NOW SEEING A FEW SHOWERS POP UP
ABOUT 20-30 MILES E OF FERNANDINA BEACH. OTHERWISE...WITH MID
LEVEL HIGH PRES OFFSHORE THE E COAST SEA BREEZE WILL HAVE NO
PROBLEMS MOVING INLAND THIS AFTERNOON WITH BEST COVERAGE OF SEA
BREEZE-INFLUENCED SHOWERS AND A FEW STORMS OVER INLAND NE FL WHERE
30-40% SHOULD BE MORE THAN ADEQUATE TO COVER THE PRECIP POTENTIAL.
ONLY 20-30% ADVERTISED FOR SE GA ATTM REST OF TODAY. MODIFIED
MODEL SOUNDINGS PRODUCE SBCAPE OF ABOUT 2000-2500 J/KG WITH
POTENTIAL DOWNBURST GUST TO 35 KNOTS (40 MPH)...WHICH WILL BE
MOST LIKELY OVER INLAND NE FL AFTER 2 PM TODAY.
&&
.AVIATION...PREVAILING VFR WITH SCT-LCL BROKEN CUMULUS 2500-3500
FT AND MID LEVEL CLOUDINESS AT TIMES. A FEW SHOWERS POSSIBLE
VICINITY OF NE FL COASTAL TAFS AS DAYTIME HEATING COMMENCES. HAVE
VCTS FOR GNV LATER THIS AFTERNOON. NO TEMPO GROUPS NEEDED ATTM.
WEAK AND VARIABLE WINDS NEXT FEW HOURS THEN BECOME ELY TO SE THIS
AFTERNOON.
&&
.MARINE...LIGHT WINDS WILL BECOMING SE TO E AROUND 10 KT AND SEAS
OF 2-3 FT.
RIP CURRENTS: LOW RISK OF RIP CURRENTS TODAY AND THURSDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 90 71 93 73 / 20 20 20 10
SSI 85 76 86 75 / 30 10 10 10
JAX 88 74 90 73 / 30 10 20 10
SGJ 86 75 87 74 / 20 10 20 10
GNV 90 72 90 71 / 30 30 40 20
OCF 90 73 90 72 / 30 30 30 30
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
SHASHY/GUILLET
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
814 AM EDT WED SEP 10 2014
.SYNOPSIS...
A PRESSURE RIDGE EXTENDING THROUGH THE FORECAST AREA TODAY WILL BE
OFF THE COAST THURSDAY. A COLD FRONT WILL MOVE INTO THE FORECAST
AREA FRIDAY AND STALL.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE PRESSURE RIDGE EXTENDING INTO THE FORECAST AREA WILL SHIFT OFF
THE COAST THIS AFTERNOON AND TONIGHT. THERE WILL BE WEAK
CONVERGENCE ASSOCIATED WITH THE REMNANTS OF THE FRONT. THERE WERE A
FEW SHOWERS JUST SOUTH OF THE FORECAST AREA EARLY THIS MORNING.
SOME OF THE HIGH-RESOLUTION MODELS DISPLAY ISOLATED SHOWERS IN
MAINLY THE SOUTH PART OF THE FORECAST AREA THIS AFTERNOON AND
TONIGHT. HOWEVER...THE 08Z HRRR MAINTAINED DRY CONDITIONS
THROUGH TODAY. UPPER-RIDGING OVER THE AREA SHOULD HELP KEEP
MOISTURE SHALLOW WITH MID-LEVEL CAPPING. WE KEPT POPS LESS THAN 20
PERCENT. NOCTURNAL COOLING WITH SUFFICIENT LOW-LEVEL MOISTURE AND
DRY AIR ALOFT SHOULD HELP SUPPORT AREAS OF FOG LATE TONIGHT. THE
TEMPERATURE GUIDANCE WAS CLOSE.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
HIGH PRESSURE WILL PUSH INTO THE ATLANTIC BASIN THURSDAY AS THE
NEXT COLD FRONT TRACKS TOWARD THE AREA. THE COLD FRONT WILL
CROSS THE OHIO AND TN VALLEYS THURSDAY THEN MOVE INTO THE UPSTATE
THURSDAY NIGHT. THIS WILL PRODUCE INCREASING CLOUDS AND WITH
SOUTHERLY WINDS PUSHING MOISTURE BACK INTO THE AREA. PWAT VALUES
WILL INCREASE...WITH VALUES BETWEEN 1.5 AND 2.00 INCHES. ALTHOUGH
THE MODELS INDICATE A POTENTIAL FOR SHOWERS AND THUNDERSTORMS
THURSDAY AFTERNOON KEPT SLIGHT CHANCE POPS AS DRY AIR ALOFT WILL
REMAIN ALONG WITH A MID-LEVEL CAP. POPS WILL INCREASE SLOWLY
THURSDAY NIGHT AS THE FRONT MOVES CLOSER TO THE FORECAST AREA WITH
THE BEST CHANCE ACROSS THE NORTHWESTERN SECTION. TEMPERATURES THURSDAY
WILL BE IN THE LOWER 90S GIVEN SLIGHT WARM ADVECTION AHEAD OF THE
COLD FRONT. SHOULD SEE OVERNIGHT LOWS IN THE LOWER 70S.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
MODELS CONTINUE IN GOOD AGREEMENT THROUGH THE LONG TERM. THE COLD
FRONT WILL SLOW AS IT MOVES IN THE FORECAST AREA FRIDAY AND STALL
ACROSS THE AREA FRIDAY NIGHT THROUGH TUESDAY. WITH HIGH PRESSURE
BUILDING INTO THE SOUTHERN GREAT LAKES REGION SATURDAY COOLER AND
DRIER AIR WILL BEGIN MOVING SOUTHWARD THROUGH THE EASTERN US AND
BEGIN FILTERING INTO THE FORECAST AREA LATE IN THE WEEKEND. WITH
THE FRONT ACROSS THE REGION CHANCES OF SHOWERS AND THUNDERSTORMS
WILL CONTINUE WITH THE HIGHEST POPS CURRENTLY EXPECTED FRIDAY
THROUGH SATURDAY...WITH SOME UNCERTAINTY IN POPS FOR MONDAY AND
TUESDAY. TEMPERATURES THROUGH THE LONG TERM WILL BE NEAR NORMAL
THROUGH FRIDAY NIGHT WITH BELOW NORMAL READINGS EXPECTED FOR
SATURDAY AND BELOW NORMAL FOR SUNDAY THROUGH TUESDAY.
&&
.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
EXPECT MAINLY VFR CONDITIONS THROUGH THE EVENING WITH GENERALLY HIGH
PRESSURE RIDGING INTO THE AREA. WEAK CONVERGENCE AND MOISTURE ASSOCIATED
WITH THE REMNANTS OF A FRONT COULD POSSIBLY HELP SUPPORT SHOWERS THIS
AFTERNOON AND TONIGHT BUT THE CHANCE IS VERY LOW BECAUSE OF UPPER-
LEVEL RIDGING WITH SHALLOW MOISTURE AND MID-LEVEL CAPPING.
NOCTURNAL COOLING WITH SUFFICIENT LOW-LEVEL MOISTURE AND DRY AIR
ALOFT SHOULD HELP SUPPORT AREAS OF FOG LATE TONIGHT AND EARLY
THURSDAY MORNING.
.EXTENDED AVIATION OUTLOOK...A FRONTAL SYSTEM WILL MOVE INTO THE
AREA THURSDAY NIGHT AND FRIDAY. THE FRONT WILL THEN STALL. WIDESPREAD
MVFR OR IFR CONDITIONS WILL LIKELY BE ASSOCIATED WITH THIS FEATURE
THURSDAY NIGHT THROUGH SUNDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
907 PM CDT THU SEP 11 2014
.DISCUSSION...
905 PM CDT
MAIN FOCUS THIS EVENING IS ON POPS. FIRST...AN AREA OF SHEARED
VORTICITY STRETCHING FROM SOUTHERN NEBRASKA TO SOUTHEAST IOWA IS
CONTINUING TO GENERATE SOME SPOTTY SHOWER ACTIVITY ACROSS THESE
AREAS BUT THE FOCUS OF FORCING SHOULD DIMINISH THROUGH THE
EVENING. THUS AM NOT EXPECTING MEASURABLE PRECIP WITH THIS FEATURE
THOUGH SOME SPRINKLES CANNOT BE RULED OUT.
ATTENTION TURNS TO LAKE EFFECT SHOWERS THROUGH THE OVERNIGHT. WITH
HIGH PRESSURE SPREADING ACROSS THE CENTRAL/NORTHERN PLAINS AND MID
AND UPPER MISSISSIPPI RIVER VALLEY THE EVOLVING PRESSURE GRADIENT
WILL LEAD TO A NORTHEASTERLY LOW LEVEL FLOW OVERNIGHT. LAKE TO H85
DELTA T OF AROUND 17C IS CERTAINLY SUPPORTIVE OF LAKE EFFECT BUT
INVERSION HEIGHTS ARE ON THE LOWER END OF THE FAVORABLE SCALE
PEAKING AROUND 6 KFT. RADAR CONTINUES TO SHOW BANDS OF WEAK
RETURNS OVER SOUTHERN LAKE MICHIGAN WITH SOME SPOTTY RAIN REPORTED
EARLIER IN NW INDIANA. RADAR TRENDS SHOW THE LOW LEVEL FLOW HAS
BEGUN TO TURN NORTHEASTERLY. EXPECT THAT INTENSITY MAY BEGIN TO
INCREASE WITH TIME AS CONVERGENCE LIKELY BECOMES BETTER FOCUSED
INTO THE OVERNIGHT. STILL DECIDING ON DETAILS BUT AM PLANNING ON
INCREASING POPS AND ADJUSTING TO COVERAGE WORDING ACROSS MUCH OF
THE CHICAGO METRO THROUGH THE OVERNIGHT...WITH BEST CHANCES AFTER
MIDNIGHT. OTHERWISE HAVE ADJUSTED TEMPS TO BETTER REFLECT HOURLY
TRENDS WITH MINIMAL CHANGE TO OVERNIGHT LOWS.
MDB
&&
.PREV DISCUSSION...
240 PM...FORECAST CONCERNS INCLUDE MUCH BELOW NORMAL TEMPERATURES
AND CHANCES FOR SHOWERS THROUGH SATURDAY AND AGAIN ON MONDAY.
STRATUS DECK HAS REMAINED MOSTLY OVERCAST TODAY AND THAT HAS HELD
TEMPS IN THE LOWER/MID 50S MOST AREAS...SOME 20 TO 25 DEGREES
BELOW NORMAL FOR MID SEPTEMBER. SEE CLIMATE SECTION BELOW FOR
RECORDS. CLOUD COVER IS EXPECTED TO REMAIN AT LEAST BROKEN IF NOT
OVERCAST OVERNIGHT INTO FRIDAY MORNING...SO NOT EXPECTING MUCH OF
A SWING IN TEMPS WITH LOWS TONIGHT IN THE MID/UPPER 40S.
AS COLDER AIR CONTINUES TO SPREAD ACROSS THE AREA...A FEW LAKE
EFFECT RAIN SHOWERS HAVE DEVELOPED OVER THE SOUTHEASTERN PART OF
THE LAKE. AS HIGH PRESSURE MOVES NORTH OF THE AREA TONIGHT...
WINDS WILL TURN MORE NORTHEAST AND THESE LAKE EFFECT RAIN SHOWERS
WILL BEGIN TO AFFECT NORTHEAST IL OVERNIGHT INTO FRIDAY MORNING.
COVERAGE REMAINS A BIT UNCERTAIN AND HAVE ONLY BUMPED POPS UP TO
LOW CHANCE. TRENDS WILL NEED TO BE MONITORED LATER TONIGHT WITH
THE POSSIBILITY THAT POPS WILL NEED TO BE BUMPED UP FURTHER.
LAKE EFFECT RAIN SHOWERS WILL CONTINUE INLAND ACROSS NORTHERN IL
FRIDAY MORNING AS FLOW TURNS MORE EAST/NORTHEAST. CLOUD COVER WILL
LIKELY REMAIN MOSTLY CLOUDY AND THIS COULD LIMIT TEMPS TO JUST THE
50S AGAIN ON FRIDAY. SOUTHERN AREAS MAY SEE A FEW BREAKS WITH THE
POTENTIAL TO REACH 60...BUT OVERALL FRIDAY WILL CONTINUE MUCH
BELOW NORMAL.
AN UPPER WAVE WILL MOVE ACROSS THE REGION FRIDAY AFTERNOON INTO
FRIDAY EVENING WITH SHOWERS/LIGHT RAIN SPREADING ACROSS THE
NORTHWEST CWA IN THE AFTERNOON THEN ACROSS MUCH OF THE AREA EARLY
FRIDAY EVENING. BUMPED POPS UP SOME...WITH LIKELY OVER THE
NORTHERN TWO THIRDS OF THE CWA...POSSIBLE POPS WILL NEED TO BE
INCREASED HERE AS WELL...THOUGH TOTAL QFP AMOUNTS SHOULD BE IN THE
0.25 TO 0.5 INCH RANGE. THIS WAVE IS FAIRLY PROGRESSIVE...SO
TRIMMED POPS FROM THE WEST OVERNIGHT. LAKE EFFECT RAIN SHOWERS MAY
CONTINUE INTO NORTHWEST INDIANA SATURDAY MORNING BEFORE ENDING IN
THE AFTERNOON.
DESPITE SOME SUNSHINE SATURDAY...AIRMASS WILL BE EVEN COLDER THAN
TODAY AND FRIDAY. NOT SURE HOW MUCH MID SEPTEMBER SUN WILL AID
TEMP INCREASE SO MAINTAINED JUST LOWER 60S FOR HIGHS. HIGH
PRESSURE PASSES ACROSS THE REGION SATURDAY NIGHT INTO SUNDAY
MORNING WITH LOWS DIPPING INTO THE LOWER 40S MOST AREAS...BUT
WARMER IN THE IMMEDIATE CHICAGO METRO AREA.
ANOTHER FAST MOVING WAVE WILL MOVE ACROSS THE AREA MONDAY
BRINGING ANOTHER CHANCE OF SHOWERS. DEPENDING ON TIMING...CLOUD
COVER AND PRECIP COULD HOLD TEMPS DOWN MONDAY BUT FOR NOW HAVE
MAINTAINED 60S. BEYOND MONDAY...HIGH PRESSURE SPREADS ACROSS THE
REGION WITH DRY WEATHER EXPECTED MID WEEK BUT TEMPS STILL BELOW
NORMAL. CMS
&&
.CLIMATE...
900 PM CDT SEP 11 2014
AN UNSEASONABLY COOL AIR MASS OVER THE REGION INTO THE WEEKEND
COULD PUT RECORD TEMPERATURES IN JEOPARDY AT CHICAGO AND
ROCKFORD. RECORD LOW MAX TEMPERATURES ARE MOST LIKELY TO BE
THREATENED.
RECORD LOW MAX TEMPERATURES SEPTEMBER 12-13
-------------------------------------------
SEPTEMBER 12 SEPTEMBER 13
------------ ------------
CHICAGO 53/1902 55/1880
ROCKFORD 56/1943 55/1970
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* MVFR CIGS THROUGH THE PERIOD WITH A SLIGHT CHANCE OF IFR CIGS
LATE TONIGHT INTO TOMORROW MORNING.
* NE WINDS ARND 10 KT THROUGH THE MAJORITY OF THE FORECAST PERIOD
BCMG NNW FRIDAY EVENING.
* SCATTERED LAKE EFFECT SHOWERS ARE PSBL TONIGHT INTO FRIDAY
MORNING.
* MORE WIDESPREAD RAIN EXPECTED FRIDAY EVENING WITH PSBL CIG/VSBY
RESTRICTIONS.
JEE
//DISCUSSION...UPDATED 00Z...
HIGH PRESSURE IS CENTERED OVER NE MONTANA AND STRETCHES THROUGH
THE GREAT LAKES. THE WEAK PRESSURE GRADIENT HAS ALLOWED WINDS TO
SHIFT TO N OR NE ARND 10 KT AT ALL OF THE TERMINALS. MVFR CIGS
EXTEND INTO SOUTHERN WI AND ACROSS IL. EXPECTING MVFR STRATUS
LAYER TO PERSIST THROUGH TOMORROW.
GUIDANCE CONTINUES TO INDICATE SCATTERED LAKE EFFECT RAIN SHOWERS
WILL FORM AND IMPACT THE EASTERN TERMINALS TONIGHT. CONFIDENCE
STILL REMAINS LOW IN WHEN THE SHOWERS WILL FORM AND IF THEY WILL
IMPACT THE TERMINALS. LEFT A SCT IFR LAYER IN THE TAFS...BUT HAVE
VERY LOW CONFIDENCE IN IFR.
SHOWERS DISSIPATE TOMORROW MORNING WITH NE WINDS STILL ARND 10 KT
AND MVFR CIGS. AN UPPER LEVEL DISTURBANCE MOVES THROUGH THE REGION
FRIDAY EVENING AND NIGHT BRINGING MORE WIDESPREAD RAIN TO THE
REGION. RAIN WILL IMPACT RFD FIRST IN THE LATE AFTN AND THEN MARCH
EASTWARD REACHING THE EASTERN TERMINALS IN THE EVENING. THINKING
MVFR CIGS WILL ACCOMPANY THE RAIN BUT HAVE LIMITED CONFIDENCE IN
MVFR CIGS AS WELL.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* HIGH CONFIDENCE IN THE WIND FORECAST.
* HIGH CONFIDENCE IN MVFR CIGS THROUGH THE FORECAST PERIOD...LOW
CONFIDENCE IN IFR CIGS TONIGHT.
* MEDIUM-HIGH IN LAKE EFFECT SHOWERS DEVELOPING TONIGHT...LOW IN
DIRECT IMPACTS TO TERMINALS.
* HIGH CONFIDENCE IN SHOWERS MOVING IN FRIDAY
EVENING/NIGHT...MEDIUM IN TIMING...AND LOW IN CIG/VSBY RESTRICTIONS.
JEE
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
SATURDAY...VFR.
SUNDAY...SCHC SHRA LATE.
MONDAY...CHC SHRA THEN SCHC SHRA OVERNIGHT. MVFR CIGS PSBL.
TUESDAY AND WEDNESDAY...VFR.
JEE
&&
.MARINE...
209 PM CDT
STRONG LOW PRESSURE SYSTEM THAT BROUGHT THE GALE FORCE WINDS HAS
CONTINUED TO LIFT NORTHEAST AWAY FROM THE GREAT LAKES REGION...WITH
THE GRADIENT OVER LAKE MICHIGAN STEADILY WEAKENING. THE GRADIENT
WILL REMAIN JUST ENOUGH TO PRODUCE WINDS BETWEEN 15 AND 25 KT
OVERNIGHT GENERALLY FROM THE NORTH...BEGINNING TO TURN SLIGHTLY
NORTHEAST AHEAD OF THE BROAD RIDGE OF HIGH PRESSURE OVER THE CENTRAL
PLAINS THAT IS POISED TO ARRIVE SATURDAY INTO SUNDAY MORNING.
ANOTHER FRONTAL BOUNDARY WILL ARRIVE FRIDAY EVENING WHICH WILL
PROVIDE A REINFORCING PUSH OF GUSTY NORTH WINDS TO THE LAKE...WITH
THE GRADIENT BEING SLIGHTLY TIGHTER ALONG THE SOUTHERN HALF OF THE
LAKE FRIDAY NIGHT THROUGH EARLY SATURDAY. WAVES WILL REMAIN ELEVATED
THROUGH FRIDAY NIGHT...CREATING HAZARDOUS WAVES TO SMALL CRAFT
THROUGH THIS PERIOD. THEN THE WAVES SHOULD STEADILY DIMINISH BY
EARLY SATURDAY MORNING TO ALLOW THE SMALL CRAFT TO END. HOWEVER IF
THE WINDS REMAIN ELEVATED...THIS WILL KEEP WAVES UP AS WELL THROUGH
DAYBREAK SAT. HIGH PRESSURE IS THEN POISED TO BUILD OVER LAKE
MICHIGAN SATURDAY EVENING AND CONTINUE THROUGH SUNDAY. WHICH WILL
THEN PROVIDE MUCH LIGHTER WINDS AND SUBSIDING WAVES.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014 UNTIL 5 PM SATURDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 5 PM SATURDAY.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM FRIDAY.
&&
$$
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[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
901 PM CDT Thu Sep 11 2014
.UPDATE...
ISSUED AT 900 PM CDT THU SEP 11 2014
High pressure at the surface extends from Montana to Ohio, but an
abundance of low level moisture trapped near the surface is
keeping cloud cover across a majority of the Upper Midwest. An
upper level trough positioned on top of the surface high is
focusing jet stream dynamics from South Dakota through the Great
Lakes to Ontario. Short waves in the leading edge of the upper
trough are triggering spotty showers and spreading mid and high
clouds toward western IL. Overall, a blanket of low clouds will
dominate the next 24 to 36 hours, with sunshine probably not making
much of an appearance until Saturday afternoon. Unseasonably cool
conditions will continue during that time as well, with diurnal
swings in temperature generally less than 10F.
The main updates for this evening were to increase cloud cover
tonight and tomorrow, and trim a degree or two from the low temps
across our northern counties. Updated info will be available shortly.
&&
.SHORT TERM...(Tonight)
ISSUED AT 259 PM CDT THU SEP 11 2014
Cold front just south of the Ohio River Valley this afternoon as
high pressure builds into the Midwest. Northerly flow at the sfc
bringing unseasonably cool temps into the region, in stark contrast
to the weather of the last few days. Cooler temperatures expected
to continue into the overnight hours. With lows dipping into the
upper 40s across the nrn portions of the state...and low 50s before
dawn for much of Illinois. Breaks in the cloud cover off to the
west not having much success in moving into the region. As a
result, continued cloud coverage expected through the overnight
hours as llvl RH has remained trapped. Both NAM and HRRR slow to
move clouds out, though some brief clearing is possible NW of the
Illinois River.
&&
.LONG TERM...(Friday through Thursday)
ISSUED AT 259 PM CDT THU SEP 11 2014
Cool and cloudy conditions are expected again Friday as low level
northerly flow continues with a strong capping inversion at around
850 mb. An upper level shortwave will be rapidly approaching from
the west. The axis of the shortwave expected to cross Illinois late
Friday evening to early Saturday morning...pushing another frontal
boundary through the region. Current model forecasts are fairly
consistent keeping precipitation with this feature mainly north of
I-72...and modest amounts around 0.10 inches or less. Have PoPs
beginning Friday afternoon west of I-55 as lift associated with the
approaching shortwave begins...then PoPs spread through most areas
I-55 northward Friday evening. The system moves rapidly east-
northeastward leaving a cool and dry weekend behind it...with highs
in the 60s and lows in the 40s...as high pressure settles over the
area.
The next chance for precipitation will be Monday as models
consistently track another broad trough through the midwest. Cool
dry northwesterly flow aloft is expected to follow for the remainder
of the week with little chance for any precipitation and below
normal temperatures continuing.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
ISSUED AT 656 PM CDT THU SEP 11 2014
MVFR clouds will prevail over the next 24 hours, with some
periodic IFR cloud heights possible late tonight and early Friday
morning. Subsidence under a cold dome of high pressure is keeping
a blanket of low moisture in place across much of the Upper
Midwest. A fast moving shortwave is triggering a narrow band of
showers across south-central Iowa, that are moving toward N IL.
No precip was included at PIA for now, as the trajectory of the
showers and forecast soundings do not look supportive of precip
that far south with this wave. As the upper trough rotates into N
IL tomorrow, coverage of showers will increase west of I-55. We
included a VCSH in the afternoon for all sites but CMI.
Winds will remain north to northeast over the next 24 hours, with
wind speeds climbing to around 10kt during the day, and
diminishing to 5-7kt at night.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHIMON
SHORT TERM...HJS
LONG TERM...ONTON
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
317 AM CDT WED SEP 10 2014
.DISCUSSION...
316 AM CDT
SHORT TERM FORECAST...TODAY THROUGH THURSDAY NIGHT...
CONCERNS IN THE SHORT TERM CONTINUE TO FOCUS ON HEAVY RAINFALL AND
SEVERE THUNDERSTORM POTENTIAL THROUGH TODAY.
AN ELONGATED AREA OF SURFACE LOW PRESSURE STRETCHED FROM THE
OKLAHOMA PANHANDLE INTO CENTRAL IOWA EARLY THIS MORNING...WITH
STRONG SURFACE PRESSURE FALLS OF NEARLY 4 MB PER 3 HRS DEVELOPING
FROM EASTERN IA INTO SOUTHWEST WI AND NORTHWEST IL. THIS IS WHERE
SURFACE LOW WILL CONTINUE TO ORGANIZE AND DEEPEN THIS MORNING IN
RESPONSE TO A STRONG SHORT WAVE TROUGH AND STRENGTHENING UPPER JET
STREAK LIFTING NORTHEAST FROM THE PLAINS. THE LOW WILL CONTINUE TO
LIFT EAST-NORTHEAST ACROSS WI AND LAKE MICHIGAN THROUGH THIS
AFTERNOON...TRAILING A SHARP COLD FRONT ACROSS THE FORECAST AREA
FROM MIDDAY THROUGH EARLY EVENING.
THE AFOREMENTIONED SHORT WAVE OVER THE UPPER MISSISSIPPI VALLEY
WILL CONTINUE EAST-NORTHEAST ACROSS WI/NRN IL EARLY THIS MORNING...
WITH THE BEST HEIGHT FALLS AND DIFFERENTIAL VORTICITY ADVECTION FROM
NOW THROUGH 15Z OR SO. IN ADDITION...STRENGTHENING OF AN UPPER JET
STREAK OVER THE NORTHERN LAKES IS EXPECTED TO PRODUCE A COUPLED
EXIT/ENTRANCE DIVERGENCE REGION OVER THE AREA DURING THE SAME
PERIOD. LOW LEVEL JET WHICH WAS FOCUSED ALONG THE IA/MO BORDER
EARLIER IN THE NIGHT HAS INCREASED TO 50-60 KT FROM THE SOUTHWEST
PER KEAX VAD WIND PROFILE...AND WILL LIKELY INCREASE MOISTURE
TRANSPORT AND THETA-E ADVECTION OVER THE AREA IN THE 09-15Z PERIOD.
EXPECTATION IS THUS THAT THE AREA OF ELEVATED CONVECTION/HEAVY
STRATIFORM PRECIP OVER IA/WESTERN IL AND NRN MO WILL CONTINUE TO
LIFT NORTHEAST ACROSS WRN/NRN IL THROUGH 12Z WITHIN THE STRONGEST
AXIS OF MOISTURE TRANSPORT...BEFORE SHIFTING ACROSS THE CENTRAL AND
SOUTHEASTERN PARTS OF THE CWA AND ACROSS LAKE MICHIGAN BY MID/LATE
MORNING AS SHORT WAVE AND STRONGER FORCING LIFT NORTHEAST AND THE
SURFACE LOW DEVELOPS INTO NORTHEAST WI OR NORTHERN LAKE MICHIGAN BY
EARLY AFTERNOON. UPSTREAM RAINFALL RATES HAVE GENERALLY BEEN
OBSERVED IN THE 0.50-0.75 INCH PER HOUR RANGE IN THE MODERATE TO
HEAVY STRATIFORM PRECIP. SYNOPTIC AND MESOSCALE MODELS ARE IN
GENERALLY DECENT AGREEMENT WITH QPF AMOUNTS AND PLACEMENT THOUGH
TODAY...AND HAVE USED A BLEND OF SUCH GUIDANCE WHICH YIELDS AERIAL
AMOUNTS OF 1.50-1.90 INCHES THROUGH LATE WEDNESDAY. THE NORTHWEST
HALF OF THE CWA SHOULD SEE HEAVIEST AMOUNTS THIS MORNING...WITH THE
SOUTHEAST SEEING MORE OF THEIR RAINFALL THIS AFTERNOON AND VERY
EARLY THIS EVENING AHEAD OF THE COLD FRONT. THESE RAINFALL AMOUNTS
AND RATES ARE NOT LIKELY TO PRODUCE FLASH FLOODING FOR THE MOST
PART...THOUGH AREAS THAT SEE SOME OF THE HEAVIER ELEMENTS TRACK
OVERHEAD FOR A WHILE COULD EXPERIENCE SOME PONDING OF WATER OR MINOR
FLOODING IN TYPICAL LOW SPOTS. HOWEVER...WITH THE FLASH FLOOD WATCH
ALREADY IN PLACE IT WOULD SEEM PREMATURE TO CANCEL THE
HEADLINE...ESPECIALLY WITH THE HEAVIER RAIN JUST ARRIVING EARLY THIS
MORNING.
WITH RESPECT TO THE THREAT OF SEVERE WEATHER...THE LARGE CLUSTER OF
RAIN/EMBEDDED THUNDERSTORMS AND CLOUD COVER ACROSS THE AREA THIS
MORNING WILL LIKELY IMPACT SURFACE TEMPERATURES AND DEVELOPMENT OF
BOUNDARY LAYER ROOTED INSTABILITY THIS AFTERNOON AS THE COLD FRONT
MOVES THROUGH. HOWEVER...THE STRONG DYNAMICS OF THIS EARLY AUTUMN
STORM AND INCREASING DEEP LAYER BULK SHEAR VALUES WITH THE
APPROACHING UPPER JET STREAK THIS AFTERNOON (0-6 KM VALUES 50-60
KTS!) DOES STILL WARRANT SOME RISK OF SEVERE STORMS WITH DAMAGING
WINDS ALONG/SOUTHEAST OF THE COLD FRONT THIS AFTERNOON. SPC HAS
MOVED THE SLIGHT RISK A LITTLE FARTHER SOUTHEAST OF A PONTIAC TO
GARY LINE...AND THIS SEEMS PRUDENT WITH THE POTENTIAL FOR STRONGER
INSTABILITY AND OUTFLOW/DIFFERENTIAL HEATING BOUNDARIES TO BE
FARTHER SOUTH AFTER THIS MORNINGS LARGE MCS.
OUTSIDE OF THE WIND THREAT WITH ANY THUNDERSTORMS TODAY...SOUTH AND
SOUTHWEST WINDS WILL INCREASE WITH THE DEEPENING OF THE LOW PRESSURE
SYSTEM TO OUR NORTH...WITH GUSTS OF 35-40 MPH EXPECTED. IF ANY
SIGNIFICANT DISSIPATION OF CLOUDS AND DESTABILIZATION OCCURS...40-50
KT WINDS JUST ABOVE THE BOUNDARY LAYER COULD BE TAPPED AND RESULT IN
HIGHER WIND GUSTS AHEAD OF THE COLD FRONT. EXTENSIVE DEBRIS CLOUD
COVER AND PRECIP LEND LOW CONFIDENCE TO THAT OCCURRING HOWEVER. WITH
CONSIDERABLE CLOUD COVER EXPECTED MUCH OF THE DAY HAVE TRIMMED HIGH
TEMPS BACK TO THE MID-UPPER 70S.
OTHERWISE...COLD FRONT CLEARS THE SOUTHEAST CORNER OF THE CWA EARLY
THIS EVENING WITH RAIN ENDING FROM THE WEST/NORTHWEST DURING THE
AFTERNOON AND EVENING HOURS. MUCH COOLER AIR ARRIVES OVERNIGHT WITH
TEMPS DIPPING INTO THE 40S ACROSS FAR NORTHERN/NORTH CENTRAL IL.
HIGHS GENERALLY 60-65 EXPECTED THURSDAY...WITH PERHAPS A FEW UPPER
50S ALONG THE FAR NORTH SHORE AREAS.
RATZER
EXTENDED FORECAST...FRIDAY THROUGH TUESDAY...
FRIDAY...
UPPER WAVE CURRENTLY OVER BRITISH COLUMBIA IS PROGGED TO DIG ACROSS
THE UPPER MIDWEST FRIDAY ALONG WITH MUCH COOLER TEMPERATURES ALOFT
WHICH CONTINUES TO SAG SOUTH BEHIND THE STRONG COLD FRONT THAT WILL
COME THROUGH LATER TODAY. H85 TEMPS ARE PROGGED TO FALL INTO THE LOW
SINGLE DIGITS FRIDAY WHICH WHEN COMBINED WITH DIURNAL HEATING WILL
RESULT IN STEEP LOW LEVEL LAPSE RATES. INCREASING ASCENT AHEAD OF
THE UPPER WAVE WILL OVERSPREAD THE AREA WITH CHANCES FOR PRECIP
INCREASING FROM WEST TO EAST DURING THE AFTERNOON HOURS. WARMER
TEMPERATURES IN THE MID LEVEL SHOULD CAP DEEP VERTICAL GROWTH SO
MAINLY LIGHT OCCASIONALLY MODERATE SHOWERS WOULD BE EXPECTED. THERE
MAY BE SOME LAKE ENHANCEMENT THOUGH AS DEEPER LAKE INDUCED
INSTABILITY DEVELOPS OVER LAKE MICHIGAN WHICH STEERING FLOW WILL
DRIVE TOWARDS THE ILLINOIS SHORES. AFTERNOON HIGHS ON FRIDAY ARE
EXPECTED TO BE IN THE UPPER 50S OVER NORTH CENTRAL ILLINOIS TO LOWER
60S ACROSS EAST CENTRAL ILLINOIS AND NORTHWEST INDIANA...AND AROUND
60 BETWEEN INCLUDING THE CHICAGO METRO. WITH THE DEPARTURE OF THE
UPPER WAVE FRIDAY NIGHT AND SURFACE HIGH STARTING TO BUILD INTO THE
WESTERN COUNTIES...CLEARING SKIES AND DECREASING WINDS COULD SET THE
STAGE FOR STRONG RADIATIONAL COOLING FRIDAY NIGHT...RESULTING IN LOW
40S WEST OF THE FOX RIVER VALLEY BY SATURDAY MORNING.
SATURDAY THROUGH TUESDAY...
MOST OF THIS PERIOD SHOULD BE DRY UNDER THE INFLUENCE OF SURFACE
HIGH PRESSURE...WITH THE EXCEPTION OF MONDAY WHEN ANOTHER UPPER
LEVEL DISTURBANCE IS PROGGED TO DIG ACROSS THE REGION FROM CANADA
BRINGING ADDITIONAL CHANCES FOR SHOWERS. TEMPERATURES WILL REMAIN
WELL BELOW NORMAL THROUGH THE PERIOD WITH HIGHS IN THE 60S...BUT
WILL UNDERGO A GRADUAL WARMING TREND PUSHING THE 70 MARK AGAIN BY
TUESDAY.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* RAIN OVERSPREADING THE REGION TONIGHT WITH VERY LOW CHANCES FOR
EMBEDDED THUNDERSTORM.
* THUNDERSTORMS INCREASING IN INTENSITY AND COVERAGE IN THE
PREDAWN HOURS WEDNESDAY AS A LOW LEVEL JET DEVELOPS...ALSO
RESULTING IN LOW LEVEL WIND SHEAR.
* VERY GUSTY S/SSW WINDS DEVELOPING EARLY WEDNESDAY MORNING AND
PERSISTING INTO THE AFTERNOON.
* ADDITIONAL CHANCE FOR THUNDERSTORMS EARLY TO MID AFTERNOON AHEAD
OF A COLD FRONT WHICH WILL SHIFT WINDS TO THE NORTHWEST.
BMD
//DISCUSSION...UPDATED 06Z...
EXPANSIVE AREA OF STRATIFORM RAIN IS OVERSPREADING NORTHERN ILLINOIS
CURRENTLY. STEADY RAIN IS EXPECTED THROUGH MUCH OF THE OVERNIGHT
HOURS AND WHILE CANNOT RULE OUT AN ISOLATED STROKE OF THUNDER HERE
OR THERE...THE INSTABILITY IS RATHER WEAK AND LIGHTNING ACTIVITY IS
VERY MINIMAL AWAY FROM THE LOW LEVEL JET CURRENTLY FOCUSED OVER NRN
MO. THE LOW LEVEL JET IS PROGGED TO SPREAD OVER NORTHERN ILLINOIS
LATE TONIGHT INTO THE PREDAWN HOURS WEDNESDAY MORNING AND SHOULD
ALLOW THUNDERSTORM ACTIVITY TO INCREASE AS 60KT LOW LEVEL WINDS
TRANSPORT VERY MOIST AIR INTO THE REGION ALONG WITH SOME
INSTABILITY. THE MOST FAVORABLE TIMING FOR THESE THUNDERSTORMS
REMAINS IN THE MORNING...PRIMARILY BETWEEN 10-15Z FOR THE CHICAGO
TERMINALS AND AN HOUR OR TWO EARLIER AT RFD. LLWS CONDITIONS ARE
ALSO EXPECTED AS THE LOW LEVEL JET MOVES OVERHEAD. PRECIP SHOULD
WANE IN THE LATE MORNING HOURS AS THE FORCING FROM THE LOW LEVEL JET
MOVES AWAY. MEANWHILE...LOW PRESSURE CURRENTLY CENTERED OVER THE MID
MISSOURI VALLEY WILL LIFT INTO EAST CENTRAL WISCONSIN BY LATE
MORNING WITH A TRAILING COLD FRONT PUSHING ACROSS THE TERMINALS MID
TO LATE AFTERNOON. ADDITIONAL THUNDERSTORMS ARE POSSIBLE IMMEDIATELY
AHEAD AND ALONG THE COLD FRONT AS WE START TO DESTABILIZE AGAIN
DIURNALLY. GUIDANCE REMAINS CONSISTENT THAT THE BULK OF THE ACTIVITY
WILL FORM SOUTHEAST OF RFD...THOUGH COULD FORM VERY NEAR OR OVER THE
CHICAGO TERMINALS. WILL MAINTAIN TEMPO FOR TSRA DURING THE
AFTERNOON. WINDS TURN NORTHWESTERLY BEHIND THE FRONT WITH MUCH
COOLER AIR PUSHING INTO THE REGION. SOME MODELS SUGGEST THAT THIS
COULD RESULT IN A POST FRONTAL MVFR STRATUS TOMORROW EVENING.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN RAIN TONIGHT BUT LOW CONFIDENCE IN TSRA
OVERNIGHT.
* MEDIUM CONFIDENCE IN TSRA STARTING IN THE PREDAWN HOURS AND
GOING THROUGH MID MORNING.
* LOW CONFIDENCE IN ADDITIONAL TSRA AHEAD OF THE COLD FRONT.
* MEDIUM-HIGH CONFIDENCE IN WIND DIRECTION...LOW-MEDIUM CONFIDENCE
IN WIND GUST MAGNITUDE.
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...VFR.
FRIDAY...CHC SHRA.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...SLT CHC SHRA.
BMD
&&
.MARINE...
239 AM CDT
WINDS ARE EXPECTED TO RAMP UP QUICKLY LATER THIS MORNING AS
SIGNIFICANT EARLY AUTUMN STORM SYSTEM SPREADS OVER THE LAKE LATER
THIS MORNING. LOW PRESSURE CURRENTLY OVER IOWA WILL CONTINUE TO THE
NORTHEAST AND STRENGTHEN THROUGH THE MORNING. EXPECT SOUTH WINDS TO
INCREASE TO 40 KT OVER THE SOUTHERN HALF OF THE LAKE TOWARD
DAYBREAK. DO NOT BE CAUGHT OFF GUARD GIVEN THE LIGHTER WINDS
CURRENTLY...AS WINDS WILL INCREASE VERY RAPIDLY AS THIS SYSTEM
APPROACHES AND WAVES WILL RESPOND ACCORDINGLY.
LATER THIS MORNING INTO THE EARLY AFTERNOON WINDS WILL ABATE SOME...THEN
AS THE LOW CONTINUES NORTH AND EAST THROUGH LAKE HURON AND INTO
QUEBEC...A VERY STRONG PRESSURE GRADIENT ON THE BACK SIDE OF THE
LOW COMBINED WITH A SOUTHWARD MOVING COLD FRONT WILL BRING A
PERIOD OF GALE FORCE WINDS ALONG THE NORTHERN HALF OF THE LAKE.
CONFIDENCE STILL REMAINS LOW WITH REGARDS TO GALES DEVELOPING ON
THE SOUTHERN HALF OF THE LAKE IN THE NORTHWEST WINDS BEHIND THE
LOW...BUT IF THE LOW TRACKS A BIT FARTHER SOUTH...GALES STILL
REMAIN POSSIBLE. WHILE WE FEEL THAT WINDS TO 30 KT ARE MORE LIKELY
ON THE SOUTH HALF...FEEL IT IS PRUDENT TO HANG ONTO THE WATCH
LATER THIS EVENING AND WILL OUTLINE THE DETAILS IN THE MARINE
WEATHER WARNING PRODUCT.
REGARDLESS...WAVES WILL BUILD QUICKLY AS WELL THIS MORNING IN
RESPONSE TO THE STRONG WINDS...THEN BUILD AND REMAIN HIGH THROUGH
THE LATTER HALF OF THE WEEK AS NORTH FLOW REMAINS IN PLACE.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ032 UNTIL 1 PM WEDNESDAY.
BEACH HAZARDS STATEMENT...ILZ006-ILZ014 UNTIL NOON WEDNESDAY.
FLASH FLOOD WATCH...ILZ023-ILZ033-ILZ039...7 AM WEDNESDAY TO 7
PM WEDNESDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019...7 AM
WEDNESDAY TO 7 PM WEDNESDAY.
LM...GALE WARNING...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-
LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...7 AM WEDNESDAY TO 7 PM
WEDNESDAY.
GALE WATCH...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...7 PM
WEDNESDAY TO 10 AM THURSDAY.
GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...5 PM
WEDNESDAY TO 10 AM THURSDAY.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
256 AM CDT Wed Sep 10 2014
.SHORT TERM...(Today)
ISSUED AT 256 AM CDT WED SEP 10 2014
Heavy rainfall event is commencing across west-central Illinois
early this morning, with 07z/2am radar imagery showing rain across
the western half of the KILX CWA. Further west, very heavy rain and
flash flooding is occurring across northern Missouri, where several
convective systems have trained over the same locations. Latest IR
satellite imagery shows first system dissipating west of Quincy,
while another flare up of convection is developing further west
along the Iowa/Missouri border. This activity is being fed by a
60-65kt 850mb jet streak as seen on the KEAX VWP and is tracking
E/SE along a stationary frontal boundary extending from southern
Iowa into eastern Missouri. As low pressure currently over
southwest Iowa deepens and lifts into Wisconsin later this morning,
this heavier precip area will gradually shift into west-central
Illinois. With precipitable water values exceeding 2 inches, high
rainfall rates of greater than 1 inch per hour will be possible.
Several locations along/west of I-55 already picked up between 1 and
3 inches of rain yesterday, so any additional rainfall could
potentially lead to flash flooding. As a result, current Flash
Flood Watch for much of central Illinois along and north of a
Shelbyville to Paris line will remain in effect today.
Severe weather threat remains uncertain, as widespread showers and
thunderstorms this morning will stabilize a good portion of the
area. Best bet for adequate destabilization this afternoon will be
along southern/eastern periphery of rain area. Based on current
radar trends and 00z model output, think this will mainly be focused
across the S/SE CWA. Latest convective outlook from SPC is trending
in that direction as well, with the slight risk area being shifted
further southeast than previously forecast. South of the precip
area where afternoon high temperatures will reach the lower to
middle 80s, CAPE values will likely reach the 1500 to 2000J/kg range
across southern Illinois into central/southern Indiana. Outflow
boundary from morning convection interacting with this unstable
airmass and strong low-level wind shear will likely produce a line
of strong to severe thunderstorms somewhere along/south of a
Shelbyville to Paris line by mid to late afternoon. Main severe
threat will be damaging wind gusts as the storms sink southeastward
into the evening hours.
&&
.LONG TERM...(Tonight through Tuesday)
ISSUED AT 256 AM CDT WED SEP 10 2014
Low pressure will continue to track northeastward into the Great
Lakes tonight, dragging a strong cold front through central
Illinois. Boundary is progged to be along a Chicago to Saint Louis
line early this evening, then along the Ohio River by Thursday
morning. Based on this timing, will carry categorical PoPs across
the E/SE CWA this evening, tapering down to just chance after
midnight. Further northwest, will mention chance of showers this
evening, followed by dry weather after midnight. Once front
passes, much cooler conditions will be noted on Thursday. Despite
a good deal of sunshine, strong CAA pushing 850mb temps to between
10 and 14c will result in highs only reaching the middle to upper
60s.
Even cooler weather will be on tap for Friday, as 850mb temps drop
further and clouds increase in advance of a lingering 500mb
trough axis. Models continue to show this feature passing Friday
night, accompanied by scattered showers. Latest ECMWF is quite
bullish with its QPF Friday night, while the GFS is much drier.
Think the precip will be mainly diurnal in nature, so am not ready
to raise PoPs significantly for Friday night. Will bring low
chance PoPs across the western half of the CWA Friday afternoon,
then will only go with slight chance PoPs Friday night as daytime
instability fades.
Once this feature passes, strong Canadian high pressure will
dominate the weather this weekend. Resulting high temperatures on
Saturday and Sunday will only be in the 60s, while overnight lows
dip into the 40s. Next northern stream short-wave will swing
through the region early next week, although timing discrepancies
exist among the models. GFS is slightly faster with the feature,
bringing it across central Illinois on Monday, while the ECMWF
delays in until Monday night. Due to timing differences and very
limited moisture supply, have opted to keep the forecast dry through
Tuesday at this time.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
ISSUED AT 1153 PM CDT TUE SEP 9 2014
Showers and a few thunderstorms with light to moderate rain will
progress eastward across central IL the remainder of the night.
Steady rains will eventually reach the Indiana border before
sunrise, including CMI and DEC. PIA will have the better chances
of flooding type rains by morning, as a 45kt low level jet focuses
into WC IL after midnight and moisture pooling increases just
north of the warm front. SPI will be close to the line of storms
and heavy rains approaching from N MO, but it appears there should
be a slight northward drift to keep them just north of SPI. Will
need to watch that closely for due eastward progression, for lower
vis and cigs in heavy rains. At this point, we only tempo`d heavy
rains in PIA between 08z-12z. Most areas should remain VFR, with
short periods of MVFR vis or ceilings in mod/hvy rain. The NAM
keeps indicating LIFR ceilings across the board, but GFS and EC,
and to some extent the RAP soundings do not support that scenario.
Low level wind shear still looks like a good bet for later tonight
for our western TAFs as the southerly LLJ increases to 45kt around
2k FT. We did not include DEC and CMI in the LLWS for now, based
on the latest RAP model output.
As the cold front approaches tomorrow, winds will increase out of
the south-southwest, with gusts to near 30kt at times. There
appears to be decreasing support for strong to severe storms
tomorrow unless we see a significant period of sunshine later
morning and early afternoon ahead of the front. We left just a VCTS
in the afternoon for now.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH through this evening FOR ILZ027>031-036>038-
040>042-047>051.
FLASH FLOOD WATCH from 1 PM CDT this afternoon through late
tonight FOR ILZ043>046-052>057-061.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1219 AM CDT WED SEP 10 2014
.DISCUSSION...
1100 PM CDT
FAIRLY STRATIFORM PRECIP WITH SOME EMBEDDED CONVECTION CONTINUES
TO GRADUALLY MAKE EASTWARD PROGRESS INTO CENTRAL AND NORTH-CENTRAL
ILLINOIS IN RESPONSE TO AN UPPER WAVE MOVING EAST-NORTHEAST INTO
WESTERN ILLINOIS AND HAS NOT REALLY INTENSIFIED IN THE LAST FEW
HOURS. THE BETTER CONVECTION CONTINUES ALONG A STATIONARY SURFACE
BOUNDARY ACROSS NORTHERN MISSOURI WHERE AN INCREASING LOW LEVEL
JET IS DEVELOPING. THE SURFACE LOW CONTINUES TO BE ELONGATED FROM
SOUTHWEST IOWA INTO THE TEXAS PANHANDLE. RAIN AND SOME EMBEDDED
THUNDER WILL CONTINUE TO WORK INTO THE WESTERN CWA OVER THE NEXT
FEW HOURS WITH THUNDER BECOMING MORE PREVALENT AS THE RAIN SPREADS
EASTWARD OVERNIGHT. RAIN HAS GENERALLY BEEN LIGHT TO MODERATE IN
INTENSITY TO THE WEST AND THIS WILL LIKELY BE THE CASE AS IT MOVES
INTO THE CWA OVER THE NEXT SEVERAL HOURS. HAVE SLOWED THE EASTWARD
PROGRESS IN THE GRIDS OVERNIGHT.
THE SURFACE LOW WILL CONSOLIDATE WITH PRESSURE FALLS SUGGESTING
THIS WILL OCCUR INTO SOUTHWEST AND CENTRAL IOWA. CONVECTION WILL
LIKELY CONTINUE TO EXPAND TO THE EAST AND SOUTHEAST OF THE SURFACE
LOW BUT ONGOING CONVECTION OVER NORTHERN MISSOURI MAY LIMIT THE
FEED OF MOISTURE AND THEREFORE THE INTENSITY OF THE RAINFALL WHICH
WILL THEN TRACK INTO THE CWA IN THE MORNING. WITH THE LOW PASSING
NEAR OR NORTHWEST OF THE CWA DURING THE MORNING THE THREAT FOR
MORE INTENSE CONVECTION/RAINFALL WILL BE DURING THE MORNING ACROSS
MUCH OF THE AREA. THE NOW STATIONARY BOUNDARY IS EXPECTED TO MARCH
NORTHWARD BUT IT IS NOT CERTAIN HOW QUICKLY THIS WILL OCCUR AND
WILL LIKELY HAVE A ROLE IN CONVECTIVE EVOLUTION THROUGH MIDDAY OR
SO. GIVEN THAT THERE IS STILL PLENTY OF EVOLUTION THAT NEEDS TO
OCCUR WITH THE SURFACE LOW AND THE SHIFTING OF THE LOW LEVEL JET
INTO THE WESTERN CWA WILL CONTINUE WITH THE FLASH FLOOD WATCH
THOUGH THE THREAT THROUGH MUCH OF THE OVERNIGHT APPEARS TO BE
WANING. A RESURGENCE IN INTENSITY REMAINS POSSIBLE FOR EAST AND
SOUTHEAST AREAS WEDNESDAY AFTERNOON AS THE COLD FRONT PASSES SO
WILL MAINTAIN THE HEADLINE THERE AS WELL.
MDB
//PREV DISCUSSION...
335 PM CDT
SHORT TERM...TONIGHT THROUGH FRIDAY...
MAIN CONCERNS FOR THE FORECAST PERIOD REMAIN THUNDERSTORMS AND HEAVY
RAINFALL ASSOCIATED WITH AN UNUSUALLY STRONG LATE SUMMER COLD FRONT
AND UPPER TROUGH IMPACTING THE REGION FROM LATE TONIGHT INTO
WEDNESDAY EVENING. THEN... FOLLOWING THE PASSAGE OF THIS SYSTEM...
THE FOCUS WILL SHIFT TO THE TEMPERATURE FORECAST AND THE FIRST REAL
TASTE OF AUTUMNAL WEATHER FOR LATER THIS WEEK.
FOR THE REMAINDER OF THE AFTERNOON AND INTO THE EVENING...CONDITIONS
WILL BE THE RELATIVE CALM BEFORE THE STORM. THE SFC LOW IS
BEGINNING TO DEEPEN OVER THE CNTRL PLAINS WHILE HIGH PRESSURE MOVES
OFF THE EAST COAST. INCREASING SOUTHERLY FLOW IS RAMPING UP OVER
THE LOWER AND MIDDLE MISSISSIPPI VALLEY...SETTING UP VERY STRONG
WARM/MOIST ADVECTION POINTING INTO THE MIDWEST. THIS
AFTERNOON...CONVECTIVE ACTIVITY HAS ALREADY BROKEN OUT ALONG THE
NOSE OF A 50 KT LOW LEVEL JET...EXTENDING FROM WRN IOWA INTO CNTRL
IL. THIS STRONG LOW LEVEL JET WILL CONTINUE TO PUMP MOISTURE INTO
THE REGION WHILE MOISTURE ASSOCIATED WITH THE REMNANTS OF HURRICANE
NORBERT ADVECT OVER THE REGION AT THE MID LEVELS. THE MODELS HAVE
BEEN VERY CONSISTENT ON ADVERTISING A SWATH OF PWATS OF 2.0 TO 2.5
INCHES POOLING AHEAD OF THE FRONT. THE LOW LEVEL WARM ADVECTION
AHEAD OF THE FRONT...CONVERGENCE ALONG THE FRONT...A STRONG MID
LEVEL SHORTWAVE AND A COUPLED JET ALOFT WILL ALL COMBINE TO GENERATE
STRONG AND PERSISTENT THUNDERSTORMS. THERE SHOULD BE ADEQUATE SHEAR
IN THE LOW LEVELS BETWEEN SLY SFC WINDS AND 50 KT SWLY WINDS AT
925-850MB TO SUPPORT AN INITIAL CONVECTIVE MODE SUPPORTING SOME
ISOLATED SUPERCELLS ALONG WITH THE GENERAL THUNDER. SPC HAS
OUTLOOKED THE ENTIRE CWA WITH A SLIGHT RISK OVER SEVERE
THUNDERSTORMS...WITH THE PRIMARY THREATS BEING STRONG DAMAGING WINDS
AND MARGINALLY SEVERE HAIL. THE 12Z SOUNDINGS FROM ILX/DVN INDICATE
THE FREEZING LEVEL AT 13KFT AND WITH PERSISTENT WARM ADVECTION AHEAD
OF THE COLD FRONT...THE FREEZING LEVEL WILL LIKELY RISE SOME UNTIL
THE FROPA. SO...WHILE THE ENVIRONMENT SHOULD SUPPORT SOME STRONG
ROTATING UPDRAFTS SUFFICIENT FOR LARGE HAIL...THE HIGH FREEZING
LEVELS SHOULD GIVE AMPLE TIME FOR SOME MELTING. AS FOR THE WIND
THREAT...WITH THE STRONG LOW LEVEL JET POINTING OVER THE
AREA...STRONG WINDS SHOULD BE ABLE TO MIX DOWN...PARTICULARLY IN THE
WARM SECTOR AHEAD OF THE FRONT WHERE SURFACE BASED CONVECTION SHOULD
BE ABLE TO FORM. SO...STRONG...DAMAGING WINDS WILL BE A CONCERN
DURING THE INITIAL THUNDERSTORM DEVELOPMENT LATE THIS EVENING.
HEAVY RAINFALL...
THROUGH THE NIGHT...CONVECTIVE MODE WILL TRANSITION OVER TO MORE
LINES OR CLUSTERS...AND EVENTUALLY CONGEALING INTO A LARGE AREA OF
THUNDERSTORMS. WITH FLOW ABOVE THE BOUNDARY LEVEL TO ABOUT 700MB
SWLY...AND WLY-WNWLY JET-LEVEL WINDS...CELL MOVEMENT WITHIN THE
OVERALL THUNDERSTORM AREA WILL BE TO THE NORTHEAST WHILE THE LARGER
SCALE PATTERN IS SLOWLY PROGRESSIVE TO THE EAST. SO...ANTICIPATE
THAT THERE SHOULD BE AMPLE OPPORTUNITY FOR REPEATED DEVELOPMENT OR
TRAINING OF STORMS. ALL ELEMENTS ARE COMING TOGETHER FOR A
SIGNIFICANT HEAVY RAIN EVENT. STORMS WILL BE EFFICIENT RAIN
PRODUCERS GIVEN THE DEEP LAYER MOISTURE AND RAINFALL RATES OF 2 TO 3
INCHES PER HOUR FROM SOME STORMS WILL NOT BE OUT OF THE QUESTION.
FORTUNATELY...THE PATTERN WILL BE SLOWLY...BUT STEADILY
PROGRESSIVE...SO RAINFALL WILL BE WIDESPREAD RATHER THAN CONFINED TO
A SMALL AREA. LATEST THINKING IS THAT STORM TOTAL QPF SHOULD BE
ARND 2.0 TO 2.5 INCHES. IN AREAS OF TRAINING OR REPEATED STORM
DEVELOPMENT...LOCALIZED AREAS OF 3 TO 5 INCHES TOTAL RAINFALL WILL
BE POSSIBLE. THE MOST FAVORED TIMING FOR THE STRONGEST STORMS WILL
BE LATE THIS EVENING AND OVERNIGHT. THERE MAY BE A BRIEF LULL IN
ACTIVITY DURG THE MORNING HOURS...HOWEVER...EXPECT ANOTHER UPTICK IN
ACTIVITY DURG THE LATE MORNING/EARLY AFTERNOON AS THE COLD FRONT
PUSHES THROUGH NWRN INDIANA.
MAJOR CHANGE IN AIRMASS...
FOLLOWING THE FRONTAL PASSAGE WEDNESDAY AFTERNOON AND EVENING...LOW
WILL TURN NWLY TO NLY BEHIND THE FRONT. WEAK CYCLONIC CURVATURE AND
COLD ADVECTION WILL BRING SOME INSTABILITY SHOWERS IN THE COLDER AIR
BEHIND THE FRONT...THROUGH THURSDAY...A BROAD UPPER TROUGH WILL
CARVE OUT OVER THE CNTRL CONUS. A SERIES OF NORTHERN STREAM
SHORTWAVES WILL HELP INCREASE THE AMPLITUDE OF THE UPPER TROUGH
WHILE SUPPLYING MUCH COOLER AIR TO THE REGION. BY THURSDAY
MORNING...TEMPERATURES SHOULD DROP OFF INTO THE MIDDLE 40S OVER THE
NWRN PORTION OF THE CWA...INCLUDING THE ROCKFORD METRO AREA.
SOUTHEAST OF A LINE FROM CHICAGO TO PONTIAC...LOWS THURSDAY MORNING
SHOULD REMAIN IN THE LOWER TO MIDDLE 50S. TEMPERATURES WILL NOT
HAVE MUCH OPPORTUNITY FOR DIURNAL WARMING THROUGH THE DAY GIVEN THE
PERSISTENT COLD ADVECTION...WITH HIGHS THURSDAY ONLY IN THE LOWER TO
MIDDLE 60S. THERE IS EVEN A CHANCE THAT THE ROCKFORD AREA MAY NOT
BE ABLE TO GET OUT OF THE UPPER 50S. BY FRIDAY MORNING...
TEMPERATURES IN THE LOWER TO MIDDLE 40S WILL COVE THE WHOLE
CWA...AWAY FROM THE URBANIZED PORTION OF THE CHICAGO METRO AREA.
FOR FRIDAY...MAX TEMPS SHOULD BE EVEN LOWER THAN THURSDAY...WITH
NCNTRL/NWRN IL REMAINING IN THE MIDDLE 50S WHILE NERN IL/NWRN IN
SHOULD SEE TEMPS LOW OUT IN THE LOW 60S.
KREIN
LONG TERM...FRIDAY NIGHT THROUGH TUESDAY...
THE BIG STORY IN THE EXTENDED PERIOD IS THE REINFORCING SHOT OF
UNSEASONABLY COOL AIR THAT WILL BRING EARLY TO MID OCTOBER
TEMPERATURES OVER THE WEEKEND. IN RESPONSE TO PERSISTENT HIGH
AMPLITUDE RIDGING ALONG THE WEST COAST UP TO ALASKA...A DEEP MEAN
TROUGH WILL LOCK IN OVER THE EASTERN HALF OF CANADA INTO THE
NORTHERN TIER OF THE EASTERN HALF OF THE CONUS. THIS MID/UPPER
PATTERN IS SIMILAR TO WHAT OCCURRED MUCH OF WINTER 2013-14 AND
WILL RESULT IN BELOW NORMAL TEMPERATURES CONTINUING INTO EARLY
NEXT WORK WEEK.
GUIDANCE IS CONSISTENT IN BRINGING A QUICK MOVING BUT DEEP SHORT
WAVE TROUGH OR CLOSED LOW ACROSS THE REGION FRIDAY NIGHT...WITH A
DECENT CHANCE FOR A PERIOD OF RAIN SHOWERS. MAINTAINED CHANCE POPS
IN SMART BLEND...BUT THESE MAY NEED TO BE INCREASED IF TRENDS
HOLD. AIR MASS WILL BE ANOMALOUSLY COOL...DIPPING CLOSE TO 0C AT
850 MB OVER FAR NORTHERN ILLINOIS BY 12Z SATURDAY. PROGRESSION OF
SYSTEM WILL BE KEY IN HOW COLD LOWS ARE BY EARLY SATURDAY...AS
LESS PROGRESSIVE/TIGHTER GRADIENT INDICATED BY RECENT ECMWF RUNS
WOULD INTRODUCE CLOUD COVER CONCERNS. STILL...COLD ADVECTION ALONE
LIKELY SUPPORTS LOWS IN 40S EVERYWHERE BUT IMMEDIATE CITY OF
CHICAGO. POTENTIAL DOES EXIST FOR LAKE EFFECT RAIN SHOWERS INTO
SATURDAY MORNING FOR PORTIONS OF SHORE...MAINLY NW IN...BEFORE
SUBSIDENCE ARRIVES FROM EXPANSIVE HIGH PRESSURE SPREADING IN FROM
WEST.
HIGH TEMPERATURES LOOK TO STRUGGLE INTO LOWER 60S SATURDAY
AFTERNOON. ANOMALOUSLY COOL AIR MASS AND GOOD RADIATIONAL COOLING
SETUP WITH HIGH PRESSURE OVERHEAD SATURDAY NIGHT FAVORS AREAS
OUTSIDE CHICAGO DOWN INTO AT LEAST LOWER 40S...WITH UPPER 30S
POSSIBLE IN TYPICAL COLD SPOTS. DID UNDERCUT SMART BLEND
INITIALIZATION FOR LOWS EARLY SUNDAY...AND LOWS IN 30S IN
OUTLYING AREAS COULD BE MORE WIDESPREAD THAN IN CURRENT FORECAST
IF THERE ARE NO CLOUD COVER ISSUES. WITH MEAN TROUGH OVER
REGION...TEMPERATURES WILL REMAIN BELOW NORMAL REMAINDER OF
EXTENDED...THOUGH SLOW MODERATION THROUGH 60S IS EXPECTED SUNDAY
AND MONDAY. PREVIOUS TWO RUNS OF ECMWF INDICATE ANOTHER SHORT
WAVE/REINFORCING COLD FRONT MONDAY/MONDAY NIGHT. CONFIDENCE IS
LOWER IN THIS PERIOD DUE TO FEATURE BEING MUCH LESS ROBUST ON GFS
AND ITS ENSEMBLES. FOR NOW...GRIDS INDICATE A SLIGHT CHANCE FOR
SHOWERS ON MONDAY.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* RAIN OVERSPREADING THE REGION TONIGHT WITH VERY LOW CHANCES FOR
EMBEDDED THUNDERSTORM.
* THUNDERSTORMS INCREASING IN INTENSITY AND COVERAGE IN THE
PREDAWN HOURS WEDNESDAY AS A LOW LEVEL JET DEVELOPS...ALSO
RESULTING IN LOW LEVEL WIND SHEAR.
* VERY GUSTY S/SSW WINDS DEVELOPING EARLY WEDNESDAY MORNING AND
PERSISTING INTO THE AFTERNOON.
* ADDITIONAL CHANCE FOR THUNDERSTORMS EARLY TO MID AFTERNOON AHEAD
OF A COLD FRONT WHICH WILL SHIFT WINDS TO THE NORTHWEST.
BMD
//DISCUSSION...UPDATED 06Z...
EXPANSIVE AREA OF STRATIFORM RAIN IS OVERSPREADING NORTHERN ILLINOIS
CURRENTLY. STEADY RAIN IS EXPECTED THROUGH MUCH OF THE OVERNIGHT
HOURS AND WHILE CANNOT RULE OUT AN ISOLATED STROKE OF THUNDER HERE
OR THERE...THE INSTABILITY IS RATHER WEAK AND LIGHTNING ACTIVITY IS
VERY MINIMAL AWAY FROM THE LOW LEVEL JET CURRENTLY FOCUSED OVER NRN
MO. THE LOW LEVEL JET IS PROGGED TO SPREAD OVER NORTHERN ILLINOIS
LATE TONIGHT INTO THE PREDAWN HOURS WEDNESDAY MORNING AND SHOULD
ALLOW THUNDERSTORM ACTIVITY TO INCREASE AS 60KT LOW LEVEL WINDS
TRANSPORT VERY MOIST AIR INTO THE REGION ALONG WITH SOME
INSTABILITY. THE MOST FAVORABLE TIMING FOR THESE THUNDERSTORMS
REMAINS IN THE MORNING...PRIMARILY BETWEEN 10-15Z FOR THE CHICAGO
TERMINALS AND AN HOUR OR TWO EARLIER AT RFD. LLWS CONDITIONS ARE
ALSO EXPECTED AS THE LOW LEVEL JET MOVES OVERHEAD. PRECIP SHOULD
WANE IN THE LATE MORNING HOURS AS THE FORCING FROM THE LOW LEVEL JET
MOVES AWAY. MEANWHILE...LOW PRESSURE CURRENTLY CENTERED OVER THE MID
MISSOURI VALLEY WILL LIFT INTO EAST CENTRAL WISCONSIN BY LATE
MORNING WITH A TRAILING COLD FRONT PUSHING ACROSS THE TERMINALS MID
TO LATE AFTERNOON. ADDITIONAL THUNDERSTORMS ARE POSSIBLE IMMEDIATELY
AHEAD AND ALONG THE COLD FRONT AS WE START TO DESTABILIZE AGAIN
DIURNALLY. GUIDANCE REMAINS CONSISTENT THAT THE BULK OF THE ACTIVITY
WILL FORM SOUTHEAST OF RFD...THOUGH COULD FORM VERY NEAR OR OVER THE
CHICAGO TERMINALS. WILL MAINTAIN TEMPO FOR TSRA DURING THE
AFTERNOON. WINDS TURN NORTHWESTERLY BEHIND THE FRONT WITH MUCH
COOLER AIR PUSHING INTO THE REGION. SOME MODELS SUGGEST THAT THIS
COULD RESULT IN A POST FRONTAL MVFR STRATUS TOMORROW EVENING.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN RAIN TONIGHT BUT LOW CONFIDENCE IN TSRA
OVERNIGHT.
* MEDIUM CONFIDENCE IN TSRA STARTING IN THE PREDAWN HOURS AND
GOING THROUGH MID MORNING.
* LOW CONFIDENCE IN ADDITIONAL TSRA AHEAD OF THE COLD FRONT.
* MEDIUM-HIGH CONFIDENCE IN WIND DIRECTION...LOW-MEDIUM CONFIDENCE
IN WIND GUST MAGNITUDE.
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...VFR.
FRIDAY...CHC SHRA.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...SLT CHC SHRA.
BMD
&&
.MARINE...
221 PM CDT
THE MAIN FORECAST CONCERNS CONTINUE TO CENTER AROUND A SIGNIFICANT
STORM SYSTEM EXPECTED TO IMPACT THE GREAT LAKES WEDNESDAY AND
WEDNESDAY NIGHT.
SOUTHERLY WINDS ARE EXPECTED TO INCREASE RAPIDLY LATE TONIGHT AS A
STRENGTHENING AREA OF LOW PRESSURE MOVES FROM IOWA INTO SOUTHWESTERN
WISCONSIN. SOUTHERLY GALES OF 35 TO 40 KT ARE EXPECTED BY EARLY
MORNING ACROSS APPROXIMATELY THE SOUTHERN HALF OF THE LAKE...AND
THESE STRONG WINDS WILL CONTINUE THROUGH THE AFTERNOON. THE LOW IS
THEN EXPECTED TO SHIFT ACROSS THE NORTHERN PORTION OF THE LAKE BY
WEDNESDAY EVENING...AND THIS SHOULD RESULT IN A SHORT PERIOD OF
LIGHT AND VARIABLE WINDS NEAR ITS TRACK EARLY THURSDAY EVENING.
HOWEVER...ONCE THIS LOW SHIFTS EAST OF THE LAKE BY LATER WEDNESDAY
EVENING...A STRONG COLD FRONT WILL PUSH OVER THE LAKE. THIS SHOULD
ALLOW FOR A PERIOD OF STRONG NORTH-NORTHWESTERLY WINDS OVER THE LAKE
INTO THURSDAY. AT THIS TIME...IT APPEARS THE MAIN THREAT FOR GALES
MAY SHIFT OVER THE NORTHERN HALF OF THE LAKE INTO EARLY THURSDAY
MORNING...WITH NEAR GALE FORCE WINDS POSSIBLE OVER THE SOUTHERN END
OF THE LAKE.
WINDS WILL GRADUALLY ABATE SOME INTO THE LATER PORTION OF THE WEEK
AS HIGH PRESSURE BUILDS IN ACROSS THE PLAINS AND UPPER MIDWEST.
HOWEVER...THE NORTHERLY FETCH WILL LIKELY CONTINUE TO PRODUCE SOME
HIGHER 4 + FOOT WAVES THROUGH AT LEAST FRIDAY. ANOTHER SYSTEM COULD
IMPACT PORTIONS OF THE LAKE ON SATURDAY...POSSIBLY LEADING TO A
PERIOD OF ENHANCED NORTHERLY WINDS AGAIN. HOWEVER...UNCERTAINTY IS
HIGH WITH THIS SYSTEM. IF THE SYSTEM DOES PAN OUT...IT COULD RESULT
IN WAVES HIGH ENOUGH TO SUPPORT A SMALL CRAFT ADVISORY INTO
SATURDAY.
AS FOR HEADLINES...WE HAVE ISSUED A GALE WARNING FOR THE SOUTHERN
HALF OF THE LAKE...INCLUDING THE NEAR SHORES...FOR THE DAY ON WED
WHEN STRONG SOUTHERLY WINDS ARE EXPECTED. DUE TO UNCERTAINTIES ON HOW
STRONG THE NORTHERLY WINDS WILL BE ON OVER SOUTHERN LAKE MICHIGAN ON
THE BACK SIDE OF THE SYSTEM...WE HAVE OPTED TO KEEP THE WATCH IN
PLACE FOR WEDNESDAY NIGHT FOLLOWING THE SOUTHERLY GALE EVENT.
HOWEVER...OVER THE NORTHERN PORTION OF THE LAKE NORTHERLY GALES
APPEAR MORE LIKELY WEDNESDAY NIGHT..SO WE HAVE ISSUED THE GALE
WARNING THERE FOR WEDNESDAY EVENING THROUGH EARLY THURSDAY.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ032 UNTIL 1 PM WEDNESDAY.
BEACH HAZARDS STATEMENT...ILZ006-ILZ014...5 AM WEDNESDAY TO NOON
WEDNESDAY.
FLASH FLOOD WATCH...ILZ023-ILZ033-ILZ039...7 AM WEDNESDAY TO 7
PM WEDNESDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019...7 AM
WEDNESDAY TO 7 PM WEDNESDAY.
LM...GALE WARNING...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-
LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...7 AM WEDNESDAY TO 7 PM
WEDNESDAY.
GALE WATCH...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...7 PM
WEDNESDAY TO 10 AM THURSDAY.
GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...5 PM
WEDNESDAY TO 10 AM THURSDAY.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1153 PM CDT Tue Sep 9 2014
.UPDATE...
ISSUED AT 900 PM CDT TUE SEP 9 2014
The 35-45kt low level jet around 850mb is progressing toward IL
from the SW. Moisture transport is increasing as a result, with
PWAT values climbing toward 2 inches. The nearly stationary warm
from angled from NW to SE in eastern Missouri will continue to
provide a lifting mechanism for shower/storm development the rest
of the night.
A progressive MCS is forecast by the high res models to move from
NW Missouri across N IL overnight, which will possibly clip our NW
counties after midnight. Areas NW of the IL river will have the
best chances of getting heavy rain and strong winds from that
complex. We kept categorical PoPs for that area overnight, with
heavy rain in the grids. The flash flood watch coverage still
looks good for timing and coverage. No changes will be needed
there.
The severe threat for Wed afternoon still hinges greatly on the
amount of sunshine that develops ahead of the cold front. Wind
shear will be present, as well as plenty of moisture, so
instability will be the question-mark. Forecast soundings show
limited instability even during the afternoon due to a moist
adiabatic profile, but areas of clearing and heating can quickly
produce high CAPEs. Will keep tomorrows forecast as is, with
severe potential for nearly all of our counties except western
portions of Knox and Stark counties.
Even update mainly for weather/PoPs.
&&
.SHORT TERM...(Tonight)
ISSUED AT 305 PM CDT TUE SEP 9 2014
Issued a flash flood watch for areas from I-55 west from this
afternoon through 7 pm Wed. Issued flash flood watch for east
central IL for Wed afternoon and Wed evening. MCS still affecting
a part of central IL with showers and thunderstorms sw of I-74 and
west of I-57. Thunderstorms with heavy rains over parts of Morgan
and southern Sangamon counties. Have increased chances of showers
and thunderstorms over central and western areas tonight with
heaviest rains shifting into areas nw of the IL river during the
night. SPC continues a slight risk of severe storms from I-55 nw
into tonight with main threat damaging wind gusts where 30% risk
nw of IL river. Muggy lows in the upper 60s to around 70F with
south southeast winds prevailing tonight.
&&
.LONG TERM...(Wednesday through Tuesday)
ISSUED AT 305 PM CDT TUE SEP 9 2014
Showers and thunderstorms will likely be ongoing to start the day
for much of the forecast area west of I-55. This convective complex
will be tied fairly closely to a deepening surface low that will be
lifting into the Great Lakes region during the day. East of I-55 the
day will likely start out dry. Then, attention turns to the cold
front trailing from the surface low. This strong front will sweep
through the forecast area, mainly during the Wednesday afternoon and
evening hours. Unfortunately, there are still model disagreements
with the speed of the front, differences that will likely have a
significant impact on our severe weather threat. The ECMWF remains
the slowest, while the NAM has trended faster and is now closer to
the GFS speed. However, WPC does not favor the NAM`s recent trend of
a deeper surface low and associated faster frontal speed. So, will
continue to favor the more consistent ECMWF (although the GFS has
been fairly consistent with is quicker solution).
Severe storms and heavy rainfall are still a threat until the cold
front clears the area. The main severe storm threat still appears to
be in the Wednesday afternoon/evening hours along/ahead of the cold
front where the best pre-frontal instability (1500-2500 j/kg) and
bulk shear (35-45 kts) will be co-located. However, if a faster
frontal speed verifies, the instability will likely end up quite a
bit lower and reduce the severe threat. Any storms until the front
clears the area have the potential to be heavy rain producers, with
precipitable water values apt to be in excess 2 inches.
Once the strong cold front clears the area by late Wednesday night,
a much cooler than normal weather pattern should linger through the
end of the forecast period. Upper level troffing should remain in
place, accompanied by a Canadian surface high more often than not.
There are still some stronger waves expected to track through the
mean trof that may produce rainfall. However, model agreement in
this regard still leaves much to be desired, especially next week.
At this point, the best model clustering suggests showers are
possible later Friday into Friday night, and this is the only period
I have left slight chances for showers in place. Temperatures to
start the period should average 60s for highs and 40s for lows,
climbing into the 70s and 50s respectively by the end of the period.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
ISSUED AT 1153 PM CDT TUE SEP 9 2014
Showers and a few thunderstorms with light to moderate rain will
progress eastward across central IL the remainder of the night.
Steady rains will eventually reach the Indiana border before
sunrise, including CMI and DEC. PIA will have the better chances
of flooding type rains by morning, as a 45kt low level jet focuses
into WC IL after midnight and moisture pooling increases just
north of the warm front. SPI will be close to the line of storms
and heavy rains approaching from N MO, but it appears there should
be a slight northward drift to keep them just north of SPI. Will
need to watch that closely for due eastward progression, for lower
vis and cigs in heavy rains. At this point, we only tempo`d heavy
rains in PIA between 08z-12z. Most areas should remain VFR, with
short periods of MVFR vis or ceilings in mod/hvy rain. The NAM
keeps indicating LIFR ceilings across the board, but GFS and EC,
and to some extent the RAP soundings do not support that scenario.
Low level wind shear still looks like a good bet for later tonight
for our western TAFs as the southerly LLJ increases to 45kt around
2k FT. We did not include DEC and CMI in the LLWS for now, based
on the latest RAP model output.
As the cold front approaches tomorrow, winds will increase out of
the south-southwest, with gusts to near 30kt at times. There
appears to be decreasing support for strong to severe storms
tomorrow unless we see a significant period of sunshine later
morning and early afternoon ahead of the front. We left just a VCTS
in the afternoon for now.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH through Wednesday evening FOR ILZ027>031-
036>038-040>042-047>051.
FLASH FLOOD WATCH from Wednesday afternoon through late
Wednesday night FOR ILZ043>046-052>057-061.
&&
$$
UPDATE...SHIMON
SHORT TERM...07
LONG TERM...BAK
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1149 PM CDT TUE SEP 9 2014
.UPDATE...
ISSUED AT 905 PM CDT TUE SEP 9 2014
REALLY THE ONLY CONCERN TONIGHT IS HEAVY RAIN AND FLOODING AS SEVERE
THREAT VERY LOW WITH SATURATED SOUNDING AND LIMITED SUB CLOUD
BUOYANCY.
LINEAR MCS CONTINUES SAGGING S/SE INTO LOW LEVEL MOIST AXIS AND IS
INTERCEPTING MAIN LOW LEVEL JET AND MOISTURE TRANSPORT FEED.
MUCH OF CONVECTION AND HEAVY RAIN CONCERNS WILL EXIST NEAR TO SOUTH
OF I-80 REST OF EVE... WITH STRATIFYING PCPN SHIELD ACROSS NORTH.
CONCERNS EXIST THAT THE LONGER THIS CONVECTION CONTINUES TO OUR
SOUTH TONIGHT INTERRUPTING FOCUS OF LOW LEVEL JET AND MOISTURE
FEED...THE MORE UNCERTAINTY EXISTS WITH HEAVY RAIN THREAT
DEVELOPING ACROSS NORTHERN CWA... ALTHOUGH CANNOT BE RULED OUT IF
STORMS CAN WEAKEN TO OUR SOUTH ALLOWING LOW LEVEL JET TO REFOCUS
FURTHER NORTH WITH NORTHWARD LIFTING WARM FRONT. HAVE TRENDED
FORECASTS TOWARD HEAVIER RAINS TONIGHT ACROSS SOUTHERN HALF OF THE
CWA... BUT WILL MAINTAIN FLASH FLOOD WATCH ALL AREAS DUE TO UNCERTAINTY.
&&
.SYNOPSIS...
ISSUED AT 330 PM CDT TUE SEP 9 2014
LOW PRESSURE OVER EXTREME SOUTHEAST CO HAD A WARM FRONT EXTENDED
INTO NORTHERN MO INTO SOUTHERN IL. TEMPERATURES TO THE SOUTH OF
THE FRONT WERE WELL IN THE 80S TO MID 90S WITH DEWPOINTS IN THE
LOWER TO MID 70S. SBCAPES OF 4000 J/KG WERE OCCURRING IN WESTERN
MO. TO THE NORTH OF THE FRONT IN THE RAIN COOLED AIR READINGS WERE
ONLY IN THE UPPER 60S TO UPPER 70S. THE BEST PRESSURE FALLS WERE
LOCATED IN WESTERN KS. PRECIPITABLE WATERS WERE AS HIGH AS 1.9 INCHES
IN NORTHERN MO.
DOPPLER RADAR CONTINUED TO SHOW FESTERING SHOWERS AND A FEW
THUNDERSTORMS FROM EASTERN NEB INTO SOUTHEAST IA AND CENTRAL IL
WITH WARM AIR ADVECTION INTO THE AREA.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 330 PM CDT TUE SEP 9 2014
HEADLINES...NOW THAT MUCH OF THE AREA HAS SATURATED SOILS THE
FLASH FLOOD WATCH WILL CONTINUE TONIGHT INTO WEDNESDAY MORNING
FOR THE ENTIRE CWA.
TONIGHT...ADDITIONAL RAINFALL OF 1 TO 3 INCHES APPEAR LIKELY. SOME
LOCATIONS MAY RECEIVE 4 TO 6 INCHES...ESPECIALLY IN ANY TRAINING/REPEATING
STORMS. THIS AMOUNT OF RAIN ON VERY SATURATED SOILS WOULD CAUSE SERIOUS
FLASH FLOODING. PRECIPITABLE WATERS WILL BE AT NEAR RECORD VALUES
FOR SEPTEMBER...ABOUT 2.2 INCHES. THIS IS DUE TO RICH GULF MOISTURE
COMBINED WITH MOISTURE FROM THE REMNANTS OF WHAT WAS MAJOR PACIFIC
HURRICANE NORBERT. RAINFALL RATES WILL BE EXTREMELY HIGH SO VERY
TORRENTIAL RAINS WILL ACCOMPANY THESE STORMS. CONFIDENCE IS VERY
HIGH FOR THIS FLASH FLOOD EVENT BUT IS LOWER FOR THE SEVERE THREAT.
THERE IS THE POTENTIAL FOR LOCALIZED WET MICROBURSTS DUE TO THE
VERY SATURATED ATMOSPHERE BUT ANY HAIL SHOULD REMAIN BELOW SEVERE
LEVELS. I AM CONCERNED FOR THE POTENTIAL FOR AN ISOLATED TORNADO
OR TWO ON ANY BOUNDARY AS THE DEEP LAYER SHEAR BECOMES VERY STRONG
EVEN WELL AFTER DARK AS THE SURFACE LOW DEEPENS AND TRACKS TOWARDS
LA CROSSE WI BY 12Z WEDNESDAY. THE HRRR MESO MODEL SUGGESTS ACTIVITY
INCREASING IN OUR SOUTHERN CWA LATE THIS AFTERNOON OR TOWARDS EVENING
THEN SPREADING NORTHEAST AS THE EVENING PROGRESSES...WITH WIDESPREAD
STORMS THEN OCCURRING OVERNIGHT. SOME OF THE STRONGER STORMS WILL
ALSO PRODUCE FREQUENT TO CONTINUOUS DANGEROUS LIGHTNING. MINIMUM
TEMPERATURES WILL BE IN THE MID 60S TO LOWER 70S.
WEDNESDAY...DEEPENING CYCLONE WILL TRACK INTO THE GREAT LAKES REGION
SENDING A STRONG COLD FRONT INTO OUR WESTERN CWA IN THE MORNING AND
OUR EASTERN CWA IN THE EARLY AFTERNOON. THE THUNDERSTORMS WILL GRADUALLY
DIMINISH AND SHIFT TO THE EAST OF THE CWA WITH THE FRONT. THE SEVERE
THREAT APPEARS TO BE FARTHER TO THE EAST THAN EARLIER THOUGHT AND SPC
HAS THE SLIGHT RISK ONLY IN OUR FAR SOUTHEAST COUNTIES...BUT THIS WILL
DEPEND ON CLOUD COVER AND AMOUNT OF INSTABILITY. MAXIMUM TEMPERATURES
SHOULD RANGE FROM THE UPPER 60S AT INDEPENDENCE IA TO THE UPPER 70S
IN OUR FAR EAST/SOUTHEAST COUNTIES.
.LONG TERM...(WEDNESDAY NIGHT THROUGH NEXT TUESDAY)
ISSUED AT 330 PM CDT TUE SEP 9 2014
WEDNESDAY NIGHT THROUGH FRIDAY...SEASONABLY STRONG RIDGE STILL ON
TRACK TO DUMP DOWN THE PLAINS AND UPPER MS RVR VALLEY THIS PERIOD.
EXPECT MOST POST-FRONTAL RAINS TO BE OUT OF THE CWA AT START OF THE
PERIOD...WITH JUST DEEPENING LLVL NORTHERLY FLOW COOL ADVECTING AND
SCORING OUT THE CLOUD COVER EVENTUALLY BY THU MORNING. EVEN IF CLOUD
COVER HOLDS ON TIL DAYLIGHT...LOWS TO BE ADVECTED DOWN INTO THE 40S
IN MOST OF THE CWA. INCOMING CANADIAN AIR TO WARM ONLY INTO THE 60S
THU EVEN WITH SOME SUNSHINE...WITH A QUICK DROP OFF AFTER SUNSET THU
EVENING INTO THE 40S BEFORE INCREASING CLOUDS AHEAD OF THE NEXT
SYSTEM TOWARD FRI MORNING HALTS TEMP DROP OFF. STILL SOME PHASING
ISSUES TO BE HAMMERED OUT...BUT LATEST RUN MEDIUM RANGE SOLUTIONS
SUGGEST SOME TYPE OF WAVE/POSSIBLY RATHER VIGOROUS...TO ROLL ACRS
THE REGION ON FRI. THIS SYSTEM WILL NOT HAVE NEAR THE MOISTURE
SOURCE OR THERMODYNAMICS TO WORK WITH AS THE CURRENT SYSTEM...BUT
STILL SHOULD INDUCE A RAIN SHIELD THAT WILL OVERSPREAD MOST OF THE
CWA FROM WEST TO EAST AS FRI PROGRESSES. CLOUD COVER AND PRECIP TO
KEEP A LID ON TEMPS WITH MOST AREAS HELD IN THE 50S OR EVEN UPPER 40S
AND NORTH WINDS MAKING FOR A RAW DAY. CURRENT INDICATIONS SUGGEST
MOST AREAS TO GET FROM 0.10 UP CLOSE TO HALF AN INCH BY THE TIME THE
RAIN PULLS OUT FRI EVENING. MODELS STILL VARYING ON PRECIP AND CLOUD
COVER EXIT TIMING LATER FRI NIGHT...BUT WILL JUST KEEP PRECIP IN THE
EVENING FOR NOW. POST-WAVE SUBSIDENCE MAY MAKE FOR A LATE NIGHT
CLEAR OUT...BUT SOME CHANCE FOR SUBSIDENCE INVERSION TO TRAP CLOUDS
INTO SAT MORNING LIMITING FRI NIGHT/SAT MORNING COLD POTENTIAL. THE
GFS CONTINUES TO BE THE COLD MODEL WITH SOME UPPER 30S IN THE
NORTHWESTERN THIRD OF THE DVN CWA AND LOWER 40S ELSEWHERE. THE ECMWF
MORE IN THE WAY OF LOW TO MID 40S BUT KEEPS THE CLOUD COVER AND SOME
MIXING SFC WINDS GOING INTO SAT MORNING. WITH EXTENT OF INCOMING
UNSEASONABLY COLD AIRMASS...FEEL WITH ANY KIND OF CLEAR OUT/PARTIAL
CLEARING AND SFC WIND DROP OFF UNDER 10 MPH LATE FRI NIGHT...THE
COOLER GFS WILL PREVAIL.
SATURDAY AND SUNDAY...HIGHS ONLY RECOVERING INTO THE UPPER 50S TO
MID 60S SAT UNDER WEAK MIXING REGIME OF CANADIAN HIGH PRESSURE...
THEN HOW COLD TO GO SAT NIGHT THE CHALLENGE. IF LLVL RETURN FLOW
DOES NOT MATERIALIZE IN TIME AND THE SFC RIDGE PERSISTS LONGER
BEFORE EASTWARD MIGRATION...SAT NIGHT MAY BE THE COOLER OF THE TWO
COLD WINDOW NIGHTS BEING WATCHED RIGHT NOW...MORE IDEAL RADIATIONAL
COOLING PARAMETERS IN LINE POSSIBLY. MORE WIDESPREAD MID TO UPPER 30S
POSSIBLE ESPECIALLY EAST OF THE MS RVR CLOSER TO RIDGE CENTER. WAA
ON BACK SIDE OF RIDGE COMPLEX MAY GENERATE SOME ELEVATED SHOWERS
INTO THE WESTERN CWA BY LAT SUNDAY NIGHT...BUT CONFIDENCE LOW ON
THAT SCENARIO.
MONDAY THROUGH NEXT TUESDAY...NEXT WAVE WILL LOOK TO SHEAR ACRS THE
UPPER MIDWEST SOMETIME THIS PERIOD FOR THE NEXT RAIN CHANCE...WITH
THE 12Z RUN ECMWF MORE PHASED AN ORGANIZED WITH THIS SYSTEM MON
NIGHT INTO TUE FOR MORE SIGNIFICANT PRECIP AS OPPOSED TO THE GFS. ..12..
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1142 PM CDT TUE SEP 9 2014
CONDITIONS TO CONTINUE DETERIORATING TO WIDESPREAD MVFR WITH AREAS
OF IFR IN LOW CLOUDS OVERNIGHT WITH OCCASIONAL RAIN... AND SOME
STORMS MAINLY SOUTH OF I-80. WINDS OVERNIGHT WILL BE FROM THE EAST
AND SOUTHEAST AROUND 10 KTS AND GUSTY. STRONG COLD FRONT WILL PASS
THROUGH THE TERMINALS FROM MID AM THROUGH EARLY PM ON WED WITH
SHIFT TO GUSTY NORTHWEST WINDS. PCPN TO DIMINISH WITH FRONTAL
PASSAGE WITH LINGERING MVFR TO AREAS OF IFR CIGS LIKELY LIFTING TO
VFR AND SCATTERING OUT LATE PM AND EVE WITH INCOMING SUBSIDENCE.
&&
.HYDROLOGY...
THE RIVER WATCH WILL BE ON THROUGH MID WEEK. AFTER LAST NIGHT/S AND
THIS MORNINGS RAINS...ANOTHER 1-4 INCHES TONIGHT INTO WED MORNING
WILL DEFINITELY PRODUCE SOME FLOODING ON AREA TRIBUTARIES...DEPENDING
ON HOW WIDESPREAD THE ADDITIONAL HEAVY RAIN WILL FALL IN THE LOCAL
AREA OF CONCERN. RIVER BASINS TO WATCH FOR FLOODING POTENTIAL ON SOME
OF THE FCST POINTS FROM WED THROUGH FRI MORNING ARE THE SKUNK...
CEDAR...IOWA...WAPSI...ENGLISH...AND DES MOINES RIVERS. THE
MAQUOKETA MAY GET CLOSE. IF NOT FLOODING THEN SIGNIFICANT WITHIN BANK
RISES TO OCCUR. ..12..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...FLASH FLOOD WATCH UNTIL 7 AM CDT WEDNESDAY FOR BENTON-BUCHANAN-
CEDAR-CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA-
JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-
MUSCATINE-SCOTT-VAN BUREN-WASHINGTON.
IL...FLASH FLOOD WATCH UNTIL 9 AM CDT WEDNESDAY FOR BUREAU-CARROLL-
HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER-
PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...FLASH FLOOD WATCH UNTIL 7 AM CDT WEDNESDAY FOR CLARK-SCOTLAND.
&&
$$
UPDATE...05
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...12
AVIATION...05
HYDROLOGY...12
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
215 AM CDT WED SEP 10 2014
...UPDATE TO LONG TERM...
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 204 PM CDT TUE SEP 9 2014
LATEST RAP 400MB POTENTIAL VORTICITY APPEARS TO HAVE A DECENT
HANDLE WITH AN UPPER LEVEL DISTURBANCE THAT WAS CROSSING THE
COLORADO ROCKIES AT 18Z. GIVEN THE 18Z VERIFICATION WILL STAY
CLOSE TO THE RAP ON TIMING OF THIS UPPER LEVEL FEATURE AS IT
CROSSES EASTERN COLORADO AND WESTERN KANSAS LATER THIS EVENING.
GIVEN LATE DAY INSTABILITY AND LOCATION OF LOW LEVEL FORCING AHEAD
OF THIS UPPER LEVEL TROUGH NEAR A SURFACE BOUNDARY THAT WILL
EXTEND FROM SOUTHEAST COLORADO INTO NORTH CENTRAL KANSAS THERE
WILL BE A CHANCE FOR SCATTERED THUNDERSTORMS LATE THIS AFTERNOON
ACROSS NORTH CENTRAL KANSAS AND PORTIONS OF WEST KANSAS. BASED ON
THE 21Z TUESDAY AND 00Z WEDNESDAY CAPE AND 0-6KM SHEAR FROM THE
NAM A FEW STORMS LATE TODAY MAY BE SEVERE WITH THE AREA MORE
FAVORABLE FOR HAIL GOLF BALL SIZE OR LARGER ALONG WITH WIND GUST
IN EXCESS OF 60 MPH WILL BE ALONG AND NORTH OF A DIGHTON AND
LARNED LINE.
THUNDERSTORMS WILL THEN INCREASE IN AREAL COVERAGE EARLY TONIGHT
AS THE UPPER LEVEL DISTURBANCE CROSSES THE CENTRAL HIGH PLAINS AND
A SURFACE BOUNDARY MOVES ACROSS SOUTHWEST KANSAS. THE AREA THAT
WILL BE MORE FAVORABLE FOR WIDESPREAD THUNDERSTORMS EARLY TONIGHT
WILL BE ALONG AND NORTH OF A 700MB +10C TO +13C BAROCLINIC ZONE.
GIVEN THE 12Z NAM AND 12Z GFS THIS FAVORABLE AREA WILL BE
NORTHEAST OF A SYRACUSE TO DODGE CITY THE PRATT LINE. ALSO GIVEN
THE HIGH PRECIPITABLE WATER VALUES PERIODS THERE WILL BE A CHANCE
FOR PERIODS OF HEAVY RAIN IN THIS AREA AS WELL.
BUFR SOUNDINGS INDICATING WINDS NEAR THE SURFACE BEHIND THE COLD
FRONT WILL RANGE FROM 20 TO 30 KNOTS AS THE LOWER LEVELS BEGIN TO
SATURATE. BY 12Z WEDNESDAY THE DEPTH OF THIS LOW LEVEL MOISTURE
APPROACHES 3000FT WHICH SUPPORTS INSERTING A SLIGHT CHANCE FOR
LIGHT DRIZZLE FOR SEVERAL HOURS EARLY WEDNESDAY MORNING. BY LATE
MORNING THIS LOW LEVEL MOISTURE WILL BEGIN TO ERODE FROM SOUTHWEST
NORTHEAST AND GIVEN SOME AFTERNOON SUNSHINE ACROSS SOUTHWEST AND
SOUTH CENTRAL KANSAS THE HIGHS ARE EXPECTED TO CLIMB BACK INTO THE
MID 70S BASED ON THE 00Z THURSDAY 850MB TEMPERATURES. FURTHER
NORTH, NEAR THE INTERSTATE 70 CORRIDOR THE CLOUDS AND 850MB
TEMPERATURES AT 00Z THURSDAY SUGGEST HIGHS ON IN THE UPPER 60S TO
NEAR 70.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 215 AM CDT WED SEP 10 2014
ON THURSDAY, SFC CYCLOGENESIS WILL INCREASE ACROSS SOUTHEASTERN COLORADO.
THERE WILL BE A FAIRLY TIGHT TEMPERATURE GRADIENT AHEAD OF AN APPROACHING
COLD FRONT. CALLING FOR MID 60S ALONG THE INTERSTATE 70 CORRIDOR TO
MID 70S NEAR THE OKLAHOMA BORDER. NO PRECIPITATION IS EXPECTED UNTIL
LATE EVENING.
A STRONG FRONT IS FORECAST TO MOVE ACROSS WESTERN KANSAS AROUND 06Z
AND TOTALLY CLEARING THE FORECAST AREA BY 12Z FRIDAY. THIS FRONT HAS
CONSIDERABLE COLD AIR ADVECTION BEHIND IT WITH THE 850-HPA 0C ISOTHERM
FLIRTING WITH THE NORTHERN COUNTIES. THE WESTERN COUNTIES (GCK AND WEST)
STAND TO SEE THE MOST PRECIPITATION OF HALF OF AN INCH TO 1 INCH. FARTHER
EAST, LESS AMOUNTS ARE FORECAST AND EXPECTED. TEMPERATURES WILL STRUGGLE
TO GET OUT OF THE 50S AND CONSIDERABLE CLOUD COVER IS EXPECTED THROUGH
THE MAJORITY OF THE DAY. IT WILL FEEL VERY FALL-LIKE FRIDAY.
SURFACE HIGH PRESSURE WILL RIDGE OVER THE AREA SATURDAY MORNING WITH
THE COLDEST TEMPERATURES FORECAST OF THE SEASON SO FAR. FORECAST UPPER
30S ALONG AND NORTH OF HIGHWAY 96. THERE COULD BE SOME PATCHY FROST
TOO.
GOOD NEWS IF YOU ARE A FAN OF WARM TEMPERATURES. THE COOL SPELL WON`T
LAST LONG AND LOW LEVEL WARM AIR ADVECTION WILL BEGIN SATURDAY WITH
70S RETURNING TO THE AREA.
RELATIVELY TRANQUIL WEATHER WILL CONTINUE THROUGH THE REST OF THE PERIOD.
A FRONT MAY SPARK A FEW SHOWERS AND/OR STORMS MONDAY AND TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1222 AM CDT WED SEP 10 2014
A COLD FRONT WILL CONTINUE TO SLIP SOUTH ACROSS WESTERN KANSAS
THROUGH THE EARLY MORNING HOURS. MVFR TO IFR STRATUS CURRENTLY OVER
SOUTHERN NEBRASKA IS EXPECTED TO CONTINUE BUILDING SOUTH THROUGH
THE EARLY MORNING HOURS AND SHOULD MOVE INTO THE TAF SITES BY
AROUND 10-12Z. THE STRATUS SHOULD LAST THROUGH MUCH OF THE MORNING
BEFORE LIFTING AT GARDEN CITY AND DODGE CITY BY EARLY AFTERNOON.
THE HAYS AREA MAY SEE AT LEAST MVFR CEILINGS THROUGH THE PERIOD.
VFR CONDITIONS ARE EXPECTED THROUGH THE REMAINDER OF THE FORECAST
PERIOD AT GARDEN CITY AND DODGE CITY ALTHOUGH THERE IS SOME
POTENTIAL FOR LOW CEILINGS TO REDEVELOP AT THOSE SITES BY THE END
OF THE FORECAST PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 73 51 70 45 / 20 0 10 70
GCK 73 50 72 42 / 20 0 20 80
EHA 75 53 75 46 / 10 0 20 80
LBL 76 53 74 48 / 10 0 10 70
HYS 68 49 63 42 / 20 0 20 70
P28 78 55 74 51 / 10 0 10 60
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURGERT
LONG TERM...SUGDEN
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1222 AM CDT WED SEP 10 2014
...UPDATED AVIATION DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 204 PM CDT TUE SEP 9 2014
LATEST RAP 400MB POTENTIAL VORTICITY APPEARS TO HAVE A DECENT
HANDLE WITH AN UPPER LEVEL DISTURBANCE THAT WAS CROSSING THE
COLORADO ROCKIES AT 18Z. GIVEN THE 18Z VERIFICATION WILL STAY
CLOSE TO THE RAP ON TIMING OF THIS UPPER LEVEL FEATURE AS IT
CROSSES EASTERN COLORADO AND WESTERN KANSAS LATER THIS EVENING.
GIVEN LATE DAY INSTABILITY AND LOCATION OF LOW LEVEL FORCING AHEAD
OF THIS UPPER LEVEL TROUGH NEAR A SURFACE BOUNDARY THAT WILL
EXTEND FROM SOUTHEAST COLORADO INTO NORTH CENTRAL KANSAS THERE
WILL BE A CHANCE FOR SCATTERED THUNDERSTORMS LATE THIS AFTERNOON
ACROSS NORTH CENTRAL KANSAS AND PORTIONS OF WEST KANSAS. BASED ON
THE 21Z TUESDAY AND 00Z WEDNESDAY CAPE AND 0-6KM SHEAR FROM THE
NAM A FEW STORMS LATE TODAY MAY BE SEVERE WITH THE AREA MORE
FAVORABLE FOR HAIL GOLF BALL SIZE OR LARGER ALONG WITH WIND GUST
IN EXCESS OF 60 MPH WILL BE ALONG AND NORTH OF A DIGHTON AND
LARNED LINE.
THUNDERSTORMS WILL THEN INCREASE IN AREAL COVERAGE EARLY TONIGHT
AS THE UPPER LEVEL DISTURBANCE CROSSES THE CENTRAL HIGH PLAINS AND
A SURFACE BOUNDARY MOVES ACROSS SOUTHWEST KANSAS. THE AREA THAT
WILL BE MORE FAVORABLE FOR WIDESPREAD THUNDERSTORMS EARLY TONIGHT
WILL BE ALONG AND NORTH OF A 700MB +10C TO +13C BAROCLINIC ZONE.
GIVEN THE 12Z NAM AND 12Z GFS THIS FAVORABLE AREA WILL BE
NORTHEAST OF A SYRACUSE TO DODGE CITY THE PRATT LINE. ALSO GIVEN
THE HIGH PRECIPITABLE WATER VALUES PERIODS THERE WILL BE A CHANCE
FOR PERIODS OF HEAVY RAIN IN THIS AREA AS WELL.
BUFR SOUNDINGS INDICATING WINDS NEAR THE SURFACE BEHIND THE COLD
FRONT WILL RANGE FROM 20 TO 30 KNOTS AS THE LOWER LEVELS BEGIN TO
SATURATE. BY 12Z WEDNESDAY THE DEPTH OF THIS LOW LEVEL MOISTURE
APPROACHES 3000FT WHICH SUPPORTS INSERTING A SLIGHT CHANCE FOR
LIGHT DRIZZLE FOR SEVERAL HOURS EARLY WEDNESDAY MORNING. BY LATE
MORNING THIS LOW LEVEL MOISTURE WILL BEGIN TO ERODE FROM SOUTHWEST
NORTHEAST AND GIVEN SOME AFTERNOON SUNSHINE ACROSS SOUTHWEST AND
SOUTH CENTRAL KANSAS THE HIGHS ARE EXPECTED TO CLIMB BACK INTO THE
MID 70S BASED ON THE 00Z THURSDAY 850MB TEMPERATURES. FURTHER
NORTH, NEAR THE INTERSTATE 70 CORRIDOR THE CLOUDS AND 850MB
TEMPERATURES AT 00Z THURSDAY SUGGEST HIGHS ON IN THE UPPER 60S TO
NEAR 70.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 313 PM CDT TUE SEP 9 2014
THE TREND WILL BE FOR COOLER AND WETTER IN THE VERY EARLY PERIOD
OF THE LONG TERM FORECAST. THE PERIOD FROM WEDNESDAY INTO THE
BEGINNING OF THE WEEKEND WILL THEN BE FOLLOWED BY A MODERATE
REBOUND BACK TOWARD THE 80S BY THE MIDDLE OF NEXT WEEK.
ALL THREE MODELS, THE ECMWF, GFS AND NAM INDICATED PRECIPITATION
ALONG A STRONG FRONTOGENETIC ZONE ACROSS CENTRAL AND FAR WESTERN
KANSAS INTO SOUTHEAST COLORADO FROM LATE THURSDAY NIGHT AND
SPREADING EAST OVER CENTRAL KANSAS FRIDAY MORNING. SOME VARIABILITY
IS EXPECTED AS THE BETTER FORCING IN THE MID LEVELS IS NOT EXPECTED
TO SLIDE ALL THE WAY THROUGH THE CWA INTO OKLAHOMA, HENCE A BAND OF
HIGHER RAIN AMOUNTS COULD FALL SOMEWHERE FROM THE HIGHWAY 54
CORRIDOR NORTHWARD AS THE NAM SUGGESTS. OTHER LOCATIONS SHOULD STILL
GET SOME, BUT GENERALLY MUCH LIGHTER PRECIPITATION AMOUNTS OF A FEW
HUNDREDTHS AS THE SECONDARY FRONTAL BOUNDARY MOVES THROUGH THE
REGION IN THE FORM OF SCATTERED SHOWERS IF NOT A PERIOD OF RAIN. OF
MUCH LONGER DURATION AND IMPACT WILL BE THE WIDESPREAD STRATUS
THROUGH THE AREA, INHIBITING INSOLATION AND ENHANCING COLD
ADVECTION. THE NUMEROUS MODELS AND BLEND SOLUTIONS STRONGLY SUPPORTS
LOW 50S ACROSS MUCH OF THE AREA FOR A HIGH TEMPERATURES ON FRIDAY.
TEMPERATURES THIS COOL WILL REPRESENT ONLY A FEW DEGREES ABOVE
RECORD MIN-MAXIMUM TEMPERATURES FOR SEPTEMBER 12TH AT LEAST
LOCALLY AT DDC.
A WARMING TEND WILL BE SLOW THROUGH THE WEEKEND PERIOD. THE MEAN
LAYER WILL RETURN TO GENERALLY ZONAL PATTERN BY SUNDAY AFTER THE
LARGE WAVE EXISTS. THE NEXT WAVE WILL NOT BECOME A POTENTIAL IMPACT
UNTIL AROUND LATE SUNDAY OR MONDAY. THE PATTERN SUGGEST SOUTHWEST
KANSAS COULD BE SPLIT AS FAR AS UPPER DYNAMIC FORCING GOES, WITH
POSSIBLE MCS ACTIVITY TO THE NORTH IN THE DAKOTA`S AND NEBRASKA
AND SHORTWAVE ENERGY IN THE PANHANDLES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1222 AM CDT WED SEP 10 2014
A COLD FRONT WILL CONTINUE TO SLIP SOUTH ACROSS WESTERN KANSAS
THROUGH THE EARLY MORNING HOURS. MVFR TO IFR STRATUS CURRENTLY OVER
SOUTHERN NEBRASKA IS EXPECTED TO CONTINUE BUILDING SOUTH THROUGH
THE EARLY MORNING HOURS AND SHOULD MOVE INTO THE TAF SITES BY
AROUND 10-12Z. THE STRATUS SHOULD LAST THROUGH MUCH OF THE MORNING
BEFORE LIFTING AT GARDEN CITY AND DODGE CITY BY EARLY AFTERNOON.
THE HAYS AREA MAY SEE AT LEAST MVFR CEILINGS THROUGH THE PERIOD.
VFR CONDITIONS ARE EXPECTED THROUGH THE REMAINDER OF THE FORECAST
PERIOD AT GARDEN CITY AND DODGE CITY ALTHOUGH THERE IS SOME
POTENTIAL FOR LOW CEILINGS TO REDEVELOP AT THOSE SITES BY THE END
OF THE FORECAST PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 49 65 45 53 / 0 10 60 60
GCK 49 63 43 52 / 10 10 80 70
EHA 52 69 44 54 / 10 10 80 70
LBL 51 67 47 55 / 0 10 80 70
HYS 45 62 43 53 / 0 10 50 60
P28 53 71 54 59 / 0 10 40 70
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURGERT
LONG TERM...RUSSELL
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS PADUCAH KY
323 PM CDT Wed Sep 10 2014
.SHORT TERM...(Tonight through Friday night)
Issued at 323 PM CDT WED SEP 10 2014
The showers are still trying to dissipate over southern Illinois,
and now a tiny heavy shower has develop near KSAR in the last
scan or two. The latest HRRR indicates that there may be some
heavier convective elements with this pesky band of showers, as it
moves eastward toward the EVV Tri State late this afternoon.
Widespread cloud cover has stunted surface-based instability
today, and this may help keep the severe weather threat in check
as we move into this evening. Model soundings from southern
Illinois and southwest Indiana reveal very weak lapse rates, and
overall instability. There is decent low-level shear, possibly
enough to support a few rotating updrafts. The low-level shear
will weaken through the evening, and there is little shear above 3
km. Cannot rule out a stray severe thunderstorm, especially if it
can display supercellular characteristics. Damaging winds still
appear to be the primary concern, but large hail and a brief
tornado cannot be ruled out.
Precipitable water values are well above 2 inches, and this could
lead to some torrential rainfall. Generally followed HPC QPF
through Thursday, and this yields 1.5-2" over much of the area,
with the possible exception of the far southeast corner of the
forecast area. 1-hour and 3-hour Flash flood Guidance is well over
2", so will not be issuing a Flash Flood Watch at this time. Some
nuisance flooding in low-lying and poorly draining areas is
possible, but major problems are not expected. The heaviest rains
will be waning over the southern half of the area toward sunrise.
Still not sure when/where convective initiation will occur, but
the latest HRRR runs have been consistent and developing scattered
convection across northern portions of southeast Missouri into
southern Illinois by 00Z. Convection currently developing along
the cold front from west central Illinois into central Missouri is
moving east and should not pose any immediate concern for our
region, but figure that the convection will fill in between it and our
scattered convection through the evening.
Will keep some decent PoPs in the southeast Thursday morning, but
it should be drying out over most areas in the afternoon. Thursday
night and Friday morning should be dry, but as the next rather
sharp upper-level storm system rotates eastward out of the
central/northern Plains, would not be surprised to see some
showers develop, as moisture is drawn back northward over the
shallow Canadian airmass. This would primarily be in the south
Friday afternoon, and then throughout the area Friday night. Still
don`t think there will be much precipitation, but a slight chance
of showers seems reasonable for both periods.
As for temperatures, stayed close to the consensus of all guidance
for lows tonight with the frontal passage. With clouds,
precipitation and cool advection, went under guidance in the
southeast Thursday. Went near consensus for lows Thursday night,
and then went below guidance Friday and near or just above it Friday
night.
.LONG TERM...(Saturday through Wednesday)
Issued at 323 PM CDT WED SEP 10 2014
Surface high pressure will build into the area on Saturday,
providing much drier air and lowering temperatures. The center of
the high will pass over the Great Lakes region and then move into
the New England states. Our region should remain dry through the
weekend though as weak high pressure continues to stay situated over
us.
Models try and bring a front into the area on Monday. The front
weakens substantially as it arrives Monday into Monday night, so
chances for precipitation appear minimal at this time but cloud
cover should increase. Most of the upper level dynamics and moisture
look to be to the north of our area. However, we will have to watch
Monday night, as a few of the GFS ensemble members and the 12Z Euro
are hinting that this front could produce some light precipitation,
especially in our northwestern counties. Even the operational GFS
indicates lower level moisture increasing by Monday night.
For Tuesday, models differ on the degree of dry air filtering into
the area, in association with the area of high pressure that moves
toward us. The 12Z GFS is much more robust in scouring out the
moisture while the 00Z ECMWF seems to keep plenty of moisture
lingering until Wednesday. The 12Z run of the ECMWF is a bit more
pronounced with drying us out now but still not as much as the GFS.
Nevertheless, it looks like we`ll be dry on Tuesday. On Wednesday,
the GFS starts to bring better moisture back into the area from the
west and even hints at possible precipitation chances out in SEMO as
well. However, the 12Z run was the only run that was this quick in
bringing precipitation back in and even the 12Z ECMWF was dry.
Temperatures will be coolest on Saturday and remain in the 70s for
the majority of the extended period. There might be a few places
that reach in the lower 80s by next week. Lows will generally be in
the 50s but some upper 40s might be attainable on Saturday night
especially in the north.
&&
.AVIATION...
Issued at 1248 PM CDT WED SEP 10 2014
MVFR ceilings should lift to VFR levels in the next hour or two at
KEVV and KOWB. The band of showers that has been slowly moving
toward the area this morning, is weakening as expected, and should
have no impact on the terminals this afternoon. South southwest
winds will gust well over 20kts at times this afternoon at all sites.
Extensive cloud cover playing havoc with the destabilization
process, so the timing and location of convective initiation is
questionable. Given the forcing expected tonight, will keep
general onset from previous forecast. There could be several hours
of TS at all sites this evening into the early morning hours. The
cold front will pass the terminals late tonight, and IFR or LIFR
ceilings are a good bet behind the front. MVFR showers are also
likely through at least sunrise behind the front. Not sure how
much the ceilings will be able to lift/break up by 18Z Thursday.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...LAKE WIND ADVISORY until 6 PM CDT this evening FOR ILZ075>078-
080>094.
MO...LAKE WIND ADVISORY until 6 PM CDT this evening FOR MOZ076-086-
087-100-107>112-114.
IN...LAKE WIND ADVISORY until 6 PM CDT this evening FOR INZ081-082-
085>088.
KY...LAKE WIND ADVISORY until 6 PM CDT this evening FOR KYZ001>022.
&&
$$
SHORT TERM...DRS
LONG TERM...CW
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
308 PM CDT WED SEP 10 2014
.SHORT TERM...
RATHER MOIST AIR MASS IN PLACE ON STEADY-STATE ONSHORE FLOW AROUND
PERIPHERY OF BERMUDA RIDGE. MID LEVELS HAVE WARMED TO LIMIT THE
DEPTH OF CONVECTIVE COVERAGE THROUGH AT LEAST 89F CONVECTIVE
TEMPERATURES...OVERCOMING 500 MB WARM LAYER AROUND 91F SURFACE
TEMPERATURE. RESULT WILL BE SHORT-LIVED SLOW-MOVING BUT EFFICIENT
SHOWERS AND BRIEF THUNDERSTORMS FORMING MAINLY ON OUTFLOW
INTERSECTIONS THAT ARE PROMINENTLY DISPLAYED ON RADAR
PRESENTATION. THIS CONVECTION SHOULD DISSIPATE SHORTLY AFTER
SUNSET. MEANWHILE...EASTERLY WAVE CURRENTLY TRAVERSING THE
NORTHEAST GULF UNDER THE RIDGE WILL SERVE AS A FOCUS FOR DEEPER
LOW LEVEL MOISTURE THURSDAY AND FRIDAY. THIS IS CONSISTENT WITH
THE WRF AND HRRR MODEL RUNS FOR THURSDAY AFTERNOON AS WELL AS THE
OTHER LONGER RANGE MODELS. WILL INDICATE HIGHER RAIN CHANCES
CLOSER TO THE COAST AND TAPER DOWNWARD FARTHER INLAND THURSDAY.
WITH FRONTAL ZONE SETTLING INTO THE AREA FRIDAY...WILL BE
DIFFICULT TO DISTINGUISH FAVORED AREAS FOR FOCUSED RAINFALL DUE TO
VARIOUS CAUSES/PROCESSES...SO WILL SIMPLY GO 50 PERCENT ENTIRE
AREA. IF DEEPER GULF MOISTURE ALIGNS IN CONVERGENT BANDS...THEN
SOME LOCATIONS MAY UNDERGO SOME SHORT DURATION OF TRAINING WHICH
MAY ACCUMULATE MORE RAINFALL...MOSTLY LIKELY CLOSER TO THE COAST
THOUGH FRONTAL ZONE MAY COMPLICATE MATTERS.
.LONG TERM...
MODELS ALL AGREE IN STALLING THE FRONT ALONG OR CLOSE TO THE GULF
COAST SATURDAY AS UPPER SUPPORT SHUNTS EASTWARD. THIS DIFFERS FROM
MAN-MACHINE MIX THAT CONTINUES TO INDICATE A DEEPER FRONTAL
ADVANCE WELL INTO THE GULF BEFORE STALLING. ASSOCIATED CONVECTION
AND OUTFLOWS MAY INDUCE THE SURFACE FRONT SOUTHWARD BUT THE AIR
MASS WOULD BE GREATLY MODIFIED AND RUNNING MOSTLY ON RAIN COOLED
DENSITY. IN COORDINATION WITH SURROUNDING OFFICES...WE WILL BE
INDICATING WARMER THAN GUIDANCE TEMPERATURES FOR MORNING LOWS
SUNDAY AND MONDAY IN DEFERENCE TO NATIONAL GUIDANCE...PARTICULARLY
IF TROPICAL WAVE INFLUENCES BECOME INVOLVED THIS FAR SOUTH. WHILE
ON THE SUBJECT...THE NHC HAS HIGHLIGHTED A YELLOW OUTLOOK AREA
FROM THE BAHAMAS WESTWARD ACROSS THE NORTH GULF. THIS IS A
TROPICAL WAVE THAT SHOULD REMAIN OPEN WHILE TRAVERSING UNDER THE
UPPER RIDGE. SEVERAL MODELS INDICATE SUCH A SCENARIO...ONLY THE
CANADIAN RUN SHOWS A CLOSED LOW STRUCTURE THAT DOES NOT LOOK
ATTAINABLE GIVEN CURRENT PATTERN IN PLACE. NONETHELESS...THIS
FEATURE SHOULD SERVE TO BRING GREATER FOCUS FOR RAINFALL POTENTIAL
OVER THE WEEKEND...PARTICULARLY AS IT INTERACTS WITH ANY
STATIONARY FRONTAL FOCUS. RAINFALL POTENTIAL CAN BECOME PRONOUNCED
AND OF CONSIDERABLY LONG DURATION WHEREVER THE FRONT AND WAVE
INTERSECT. THE KEY IS WHETER IT WILL BE OFF THE COAST OR JUST
INLAND ENOUGH TO PRESENT A FLOOD THREAT FOR SOME COASTAL
COMMUNITIES. THIS WILL HAVE TO BE CLOSELY MONITORED OVER THE NEXT
FEW DAYS.
&&
.AVIATION...
VFR CONDITIONS TO PREVAIL THROUGH AT LEAST 09Z. SOME PATCHY
RADIATIONAL FOG MAY DEVELOP AT KMCB TOWARDS DAYBREAK THURSDAY THAT
MAY BRING BRIEF IFR CIGS/VSBY BUT MOST OTHER LOCATIONS SHOULD
REMAIN VFR OVERNIGHT. CONVECTION REMAINS ISOLATED IN COVEARAGE
THIS AFTERNOON AND SHORT-LIVED. GUST POTENTIAL IS AROUND 20 KT
RANGE REMAINDER OF THIS AFTERNOON AND PROJECTED 25-30 KT RANGE
THURSDAY.
&&
.MARINE...
BERMUDA RIDGE FLOW PATTERN SHOULD MAINTAIN RELATIVELY LIGHT WINDS
AND LOW SEAS FOR THURSDAY AND FRIDAY. A COLD FRONT MOVING FROM
THE NORTH IS LIKELY TO STALL BEFORE REACHING THE COAST LATE FRIDAY
OR EARLY SATURDAY. MEANWHILE...AN EASTERLY WAVE WILL BE TRAVERSING
THE NORTH GULF FRIDAY AND SATURDAY AND SHOULD INTERACT WITH THE
FRONTAL ZONE TO POTENTIALLY PRODUCE GREATER COVERAGE OF TROPICAL
SHOWERS AND THUNDERSTORMS IN THE NEAR COASTAL WATERS AND SOUNDS
THIS WEEKEND. SEAS SHOULD REMAIN LESS THAN 2 FEET THROUGH MONDAY
EVENING.
&&
.DECISION SUPPORT...
DSS CODE...GREEN.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT.
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 TO HIGH RISK SVR
AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
SIGNIFICANCE.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 72 90 72 89 / 10 30 20 50
BTR 73 91 73 90 / 10 30 20 50
ASD 74 90 73 90 / 10 30 20 50
MSY 77 90 77 90 / 10 40 20 50
GPT 76 89 75 90 / 20 40 20 50
PQL 73 90 72 89 / 20 40 20 50
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
24/RR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
153 PM EDT WED SEP 10 2014
.UPDATE...
ISSUED AT 1149 AM EDT WED SEP 10 2014
GENERALLY MINOR TWEAKS TO THE GOING FORECAST...LARGELY WITH PINNING
DOWN THE LOCATIONS OF THE HEAVIEST PRECIPITATION AND THEN WINDS FOR
THIS AFTERNOON AND TONIGHT BEHIND THE LOW.
AS FOR THE RAIN...ESSENTIALLY SEEING TWO AREAS OF
PRECIPITATION...ONE OVER THE EAST ALIGNED WITH THE BROAD 850-500MB
WARM AIR ADVECTION LIFTING TO THE NORTHEAST AHEAD OF THE LOW
CENTERED OVER SOUTH CENTRAL WISCONSIN. EXPECT THAT AREA TO CONTINUE
PUSHING TO THE NORTHEAST THROUGH THE DAY AND LARGELY DEPARTING BY
LATE AFTERNOON. THE SECOND AREA IS FARTHEST TO THE WEST AND TIED TO
THE 850-700MB FGEN AREA TO THE NORTHWEST OF THE MID LEVEL LOW.
OBSERVER REPORTS INDICATE THIS AREA OF RAIN PRODUCING AROUND
0.5-0.75IN EVERY THREE HOURS AND THAT MATCHES DUAL POL INSTANTANEOUS
PRECIP RATES. ALTHOUGH THIS AREA HAS BEEN PIVOTING AND SLOW TO MOVE
THIS MORNING...IT IS EXPECTED TO SHIFT MORE TO THE EAST-NORTHEAST
THIS AFTERNOON AS THE LOW QUICKLY MOVES NORTHEAST THROUGH NORTHERN
LAKE MICHIGAN. STILL HAVE THE FLOOD WATCH IN PLACE AND THAT SEEMS
REASONABLE OVER THE WEST (WITH THE ADDED PRECIP FROM OVERNIGHT
PUSHING TOTALS OVER 2 INCHES IN SOME LOCATIONS). FROM
MARQUETTE/DICKINSON COUNTY EAST...THINK THE POTENTIAL FOR FLOODING
IS PRETTY LIMITED BUT WILL LEAVE WATCH IN PLACE AT THIS TIME.
FINALLY FOR WINDS...MAIN ADJUSTMENTS WERE FOR AREAS OVER THE EAST
AND NEAR LAKE MICHIGAN. EXPECT THE COMBINATION OF STRONG COLD AIR
ADVECTION BEHIND THE LOW AND QUICK PRESSURE RISE TO LEAD TO GALES
AND HAVE ISSUED A GALE WARNING FOR OUR LAKE MICHIGAN ZONES. DO HAVE
A LITTLE CONCERN THAT GUSTS WILL BE NEAR 40-45MPH BRIEFLY LATE THIS
AFTERNOON INTO THE EVENING NEAR THE LAKE SUPERIOR SHORELINE AND
POTENTIALLY AT TIMES ELSEWHERE INLAND. THE OTHER AREA WAS OVER THE
KEWEENAW PENINSULA...ALTHOUGH THE FORECAST WAS IN DECENT
SHAPE...LATEST OBS AT KP59 INDICATE WINDS GUSTING TO NEAR WIND
ADVISORY CRITERIA. WITH THE CENTRAL LAKE SUPERIOR BUOY GUSTING
ABOVE 40KTS AND OTHER SITES NEAR WIND ADVISORY CRITERIA...WILL
ISSUE A WIND ADVISORY FOR KEWEENAW AND NORTHERN HOUGHTON COUNTIES
THROUGH THE EVENING HOURS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 533 AM EDT WED SEP 10 2014
LIGHT TO AT TIME HEAVY RAIN CONTINUES TO FALL OVER THE W THIRD OF
UPPER MI THIS MORNING...ASSOCIATED WITH THE SFC TROUGH THAT PUSHED
OVERHEAD EARLY THIS MORNING THE 500MB SHORTWAVE CROSSING WI...AND
THE DEEPENING SFC LOW RIDING UP ALONG THE TROUGH NEARING FROM IA.
THE LATEST SATELLITE AND RUC ANALYSIS SHOWS THIS INITIAL N SWATH OF
MOISTURE EJECTING NE ACROSS THE CWA...WITH THE EFFECTS OF THE SW TO
NE 100KT 250MB JET NEARING FROM THE PLAINS. THE SECONDARY AREA OF
CLOUDS WILL BE IMPACTING THE E HALF OF THE CWA LATER THIS MORNING
AND INTO THE AFTERNOON HOURS. EXACT RAINFALL TOTALS REMAIN TRICKY AS
THERE ARE 2 AREAS OF THOUGHT. THE LATEST 06Z NAM PAINTS AN
ADDITIONAL 1-2IN OVER CENTRAL AND E UPPER MI LATE THIS MORNING
THROUGH EARLY THIS AFTERNOON. HOWEVER...THE 00Z GFS IS PUSHING MUCH
OF THE MOISTURE JUST TO OUR E. HAVE GONE WITH A MIDDLE OF THE ROAD
SOLUTION FOR THE MOMENT...KNOWING THAT CONVECTION TO THE SOUTH COULD
STILL HURT THE INFLOW OF MOISTURE UP OUR WAY. STILL...ADDITIONAL
SHOWERS CROSSING THE CWA THIS AFTERNOON WITH BE FACED WITH STIFF N
ONSHORE FLOW...RESULTING IN A SLOWER N PROGRESSION AND OVERALL
UPSLOPE ENHANCEMENT. SEE THE HYDROLOGY SECTION FOR MORE DETAILS
ABOUT PRECIPITATION FOR THE REST OF TODAY. RAIN/RAIN SHOWERS WILL
CONTINUE THROUGH TONIGHT...MAINLY ACROSS THOSE UPSLOPE AREAS OF
CENTRAL UPPER MI. ADDITIONAL RAINFALL MAY ADD UP TO 0.25IN OR MORE
ACROSS THE HURON MOUNTAINS. FCST MODELS ARE CONTINUING TO GO WITH
THE SFC LOW TRACKING ACROSS N LOWER MI LATE THIS AFTERNOON...BEFORE
EXITING INTO S ONTARIO AND W QUEBEC LATE THIS EVENING.
TEMPERATURES WILL REMAIN TRICKY...AS THEY FALL W AND STILL RISE A
COUPLE OF DEGREES AFTER SUNRISE E. KEPT THE WIND FCST VERY SIMILAR
TO THE LAST COUPLE OF DAYS...WITH N-NNW GUSTS NEARING 35KTS FROM
AROUND 18Z TODAY TO 08Z TONIGHT. AN SPS MAY BE NEEDED FOR THE W HALF
AND HIGHER TERRAIN OF THE KEWEENAW PENINSULA...OR LOW END WIND
ADVISORY TO HIGHLIGHT THE STRONG WINDS ON TOP OF SATURATED SOILS
THAT MAY MORE EASILY UPROOT TREES THANKS TO THE ABUNDANT LEAVES. AS
FOR THE OVERNIGHT HOURS...EXPECT SLOWLY DIMINISHING WINDS LATE AND
COLD AIR TO FILTER IN WITH 850MB TEMPS OF -2 TO +4C BY DAYBREAK
THURSDAY. DEPENDING ON HOW FAST RAIN CAN GET OUT OF THE INTERIOR
AREAS ALONG THE WI BORDER...MID 30S LOWS WILL NOT BE OUT OF THE
QUESTION.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 359 AM EDT WED SEP 10 2014
MAIN FCST CONCERNS IN THE LONG TERM FOCUS ON HOW QUICKLY ON THU CLDS
AND SHOWERS ASSOCIATED WITH THE WED LO PRES WL EXIT THE CWA...TEMPS
AND THE POTENTIAL FOR FROST ON THU NGT AND THEN ON POPS ACCOMPANYING
THE PASSAGE OF ANOTHER DISTURBANCE THRU THE LOWER LKS ON FRI INTO
SAT. SINCE AN UPR TROF WL DOMINATE ERN NAMERICA THRU NEXT WEEK...
EXPECT BLO NORMAL TEMPS TO PREVAIL DURING THE EXTENDED PERIOD.
THU...AS DEPARTING LO PRES OVER FAR SW QUEBEC AT 12Z THU SHIFTS TO
THE ENE...STEADY N LLVL FLOW IS PROGGED TO WEAKEN AND BECOME MORE
ACYC UNDER GENERAL DEEP LYR QVECTOR DVGC LEFT IN THE WAKE OF THE
EXITING SHRTWV AND RDG AXIS EXPANDING TO THE E OF SFC HI CENTER IN
THE NRN PLAINS. EXPECT PLENTY OF CLDS IN THE MRNG WITH SHOWERS
MAINLY NEAR LK SUP ASSOCIATED WITH CHILLY LINGERING CYC FLOW OVER
THE RELATIVELY WARM LK SUP WATERS. BUT WITH INCRSG SUBSIDENCE/ACYC
FLOW IN THE PRESENCE OF DAYTIME HEATING...EXPECT THE SHOWERS TO
DIMINISH AND THE CLD PATTERN TO SHIFT TO MORE INLAND SC COVERAGE
UNDER THE H85 THERMAL TROF AND SUBSIDENCE INVRN SINKING TOWARD
H85-9. H85 TEMPS IN THE ZERO TO -2C RANGE WL SUPPORT WELL BLO NORMAL
HI TEMPS MAINLY IN THE UPR 40S/50S...COOLEST OVER THE HIER TERRAIN
OF THE NW HALF.
THU NGT...UNDER BLDG HI PRES WITH LOSS OF DAYTIME HEATING...EXPECT
LINGERING SC TO DSPT IN THE EVNG AND GIVE WAY TO AT LEAST A PERIOD
OF MOCLR SKIES AND LGT WINDS. WITH PWAT UNDER 0.5 INCH...TEMPS
SHOULD FALL OFF STEADILY. THE ONE LIMITING FACTOR WL BE HOW QUICKLY
HI CLDS IN ADVANCE OF SHRTWV MOVING THRU THE NRN PLAINS WL INVADE
THE UPR LKS. SUSPECT THE COLD SPOTS OVER THE INTERIOR WL SEE TEMPS
FALLING AOB 32...BUT WL HOLD OFF ON ANY KIND OF FREEZE WATCH/FROST
HEADLINE GIVEN ACTIVE SHORT TERM...MARGINALLY LO ENUF FCST TEMPS AND
COVERAGE OF THOSE REALLY LO TEMPS UNDER SOME INCRSG HI CLDS.
FRI THRU SAT...ALTHOUGH THERE IS GOOD MODEL AGREEMENT ON THE TIMING
AND TRACK OF A FAIRLY VIGOROUS SHRTWV THAT IS FCST TO MOVE E FM THE
NRN ROCKIES ON THU AFTN THRU THE NCENTRAL PLAINS AND ACROSS THE
LOWER LKS FRI NGT/SAT...THERE ARE SOME FAIRLY LARGE DIFFERENCES IN
THE MSLP FIELDS AND QPF. THE 09/12Z ECWMF CONTINUES TO BE THE MODEL
THAT SHOWS THE MORE IMPRESSIVE PRES FALL. WITH A DEEPER SFC
REFLECTION...THE ECMWF ALSO SHOWS MORE EXPANSIVE MID LVL MSTR/PCPN
EXTENDING INTO ALL OF UPR MI DURING FRI NGT/SAT MRNG. GIVEN THE
POSITIVE TILT TO THE SHRTWV....EXPANSIVE HI PRES THAT IS FCST TO
EXTEND FM THE NRN PLAINS INTO THE UPR LKS IN ADVANCE OF THIS SHRTWV
AND DRY/STABLE NATURE OF THE ANTECEDENT AIRMASS /PWAT AOB 0.5 INCH
WITH STRONG SUBSIDENCE INVRN BTWN H8-7/...SUSPECT THE NON-ECMWF
MODELS SHOWING LESS SFC RESPONSE ARE ON THE RIGHT TRACK. HAVE THUS
CHOSEN TO MAINTAIN ONLY LO CHC POPS...HIEST OVER THE SRN CWA CLOSER
TO THE SHRTWV TRACK/AREA OF SHARPER DEEP LYR QVECTOR CNVGC. THICKER
CLDS/THESE POPS WL ARRIVE ON FRI AFTN AS THE DISTURBANCE SLIDES
INTO THE UPR MS RIVER VALLEY. ONCE THE SHRTWV PUSHES TO THE E ON SAT
MRNG...TRAILING SHRTWV RDG/DRIER AIRMASS WL BRING A RETURN TO DRY
WX/CLRG. WITH H85 TEMPS IN THE ZERO TO -2C RANGE DURING THIS
TIME...THE WX WL BE UNSEASONABLY COOL. IF SKIES CLR FAST ENUF LATE
FRI NGT...NOT OUT OF THE QUESTION THERE COULD BE SOME FROST OVER THE
INTERIOR W ARND SUNRISE ON SAT.
EXTENDED...AFTER A DRY PERIOD ASSOCIATED WITH SFC HI PRES PASSING
THRU THE LOWER LKS ON SAT NGT...ANOTHER CNDN SHRTWV DIGGING THRU THE
MEAN UPR TROF CENTERED OVER HUDSON BAY AND INTO THE NCENTRAL CONUS
WL BRING A CHC OF MORE SHOWERS FOR SUN THRU MON. THIS DISTURBANCE WL
BE MSTR DEPRIVED...SO NO HEAVY RA IS LIKELY. HI PRES MOVING E UNDER
THE RISING HGTS IN THE WAKE OF THIS DISTURBANCE SHOULD BRING A
RETURN OF DRY WX FOR TUE. WITH THE MEAN TROF IN PLACE...TEMPS ACRS
UPR MI WL AVG BLO NORMAL DURING THIS TIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 152 PM EDT WED SEP 10 2014
A STRONG LOW PRESSURE SYSTEM MOVING NORTHEAST FROM SOUTH CENTRAL
WISCONSIN THROUGH NORTHERN LOWER MICHIGAN AND THEN INTO QUEBEC WILL
BRING GUSTY NORTH-NORTHEAST WINDS THROUGH TONIGHT. MODERATE RAIN
WILL CONTINUE OVER THE NEXT FEW HOURS BEFORE TRANSITIONING TO LAKE
EFFECT RAIN AT ALL THREE SITES FOR TONIGHT. THE ABUNDANT MOISTURE
WITH THIS SYSTEM WILL PRODUCE IFR CEILINGS THIS AFTERNOON WHICH
WILL GRADUALLY RISE TO MVFR TONIGHT INTO THURSDAY MORNING AS THE LOW
MOVES AWAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 AM EDT WED SEP 10 2014
AS A DEEP LO PRES MOVES NE THRU THE UPPER MIDWEST AND ACROSS
NORTHERN LOWER MI THIS EVENING ON ITS WAY INTO SE CANADA
TONIGHT...THE NE GALES AFFECTING WESTERN LAKE SUPERIOR WILL SPREAD E
OVER THE REST OF THE LAKE. EXPECT NNE GALES AS HI AS 40-45 KTS TODAY
INTO TONIGHT BEFORE THE LO PRES SHIFTS FAR ENOUGH TO THE E AND THE
GALES DIMINISH W TO E TONIGHT. AS HI PRES BUILDS TOWARD LAKE SUPERIOR
FROM THE PLAINS ON THU...LINGERING N WINDS UP TO 25-30 KTS IN THE
MORNING WILL DIMINISH W-E TO UNDER 15-20 KTS BY THE EVENING.
RELATIVELY LIGHT WINDS UNDER 20 KTS WILL THEN DOMINATE THRU THE
WEEKEND UNDER A RELATIVELY WEAK PRES GRADIENT.
&&
.HYDROLOGY...
ISSUED AT 426 AM EDT WED SEP 10 2014
RAINFALL OVER THE W THIRD OF UPPER MI HAS BEEN CONVECTIVELY
ENHANCED...WITH RAINFALL RATES BRIEFLY RISING TO NEAR 6IN PER HOUR.
WITH THE QUICK MOVEMENT TO THE N JUST OVER 20KTS THAT AMOUNT WAS NOT
REALIZED. RADAR ESTIMATES THROUGH 08Z HAVE THE HIGHEST AMOUNTS OVER
NW GOGEBIC AND ALONG THE E ONTONAGON/W HOUGHTON COUNTIES...WITH 1.5
TO 2.25IN. SOME LOCAL RIVERS CONTINUE TO RESPOND TO THE RAINFALL A
FEW DAYS AGO...AND ARE RISING AT AN INCREASED RATE DO TO THE CURRENT
RAIN. SPECIFICALLY THIS INCLUDES THE SOUTH BRANCH OF THE ONTONAGON
RIVER AT EWEN /WHICH GIVEN THE TREND WILL SEE A SLOW RISE FOR THE
NEXT SEVERAL DAYS/. THE MIDDLE BRANCH OF THE ONTONAGON RIVER AT
PAULDING IS ALSO SLOWLY ON THE RISE.
OTHERWISE AN AVERAGED 0.5IN HAS FALLEN W OF A LINE FROM
IRON RIVER TO BARAGA. LITTLE RAIN HAS FALLEN E OF THIS LINE...WHICH
WILL CHANGE OVER THE NEXT COUPLE OF HRS AS ADDITIONAL SHOWERS NEAR
FROM WI. THUNDERSTORMS ARE MINIMAL OVER WI...AND PRECIP IS SLOWER
THAN ORIGINALLY ANTICIPATED. HAVE BACKED OFF ON THE STORM TOTAL
PRECIP OVER THE E THIRD OF THE FCST AREA AS A RESULT. EXPECT THE
TRADITIONAL URBAN/SMALL STREAM FLOODING TO BE A SIGNIFICANT
POSSIBILITY IN THE TYPICAL POOR DRAINAGE AREAS OF ESC IF A PERIOD OF
HEAVIER DOWNPOURS DEVELOP WITH RAINFALL RATES CLOSE TO AN 0.5-1.0
INCH PER HOUR. N CNTRL UPPER MI WILL STILL LIKELY SEE SOME UPSLOPE
LAKE ENHANCEMENT TODAY-TONIGHT. THE FLOOD WATCH REMAINS POSTED FOR
MUCH OF W AND CENTRAL UPPER MI FOR TODAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FLOOD WATCH UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR
MIZ001>006-009>013-084.
WIND ADVISORY UNTIL 2 AM EDT THURSDAY FOR MIZ001-003.
LAKE SUPERIOR...
GALE WARNING FROM 8 PM THIS EVENING TO 8 AM EDT THURSDAY FOR
LSZ251-267.
GALE WARNING UNTIL 5 AM EDT THURSDAY FOR LSZ246>250-265-266.
GALE WARNING UNTIL 4 AM EDT THURSDAY FOR LSZ243>245-264.
GALE WARNING UNTIL 2 AM EDT /1 AM CDT/ THURSDAY FOR LSZ240>242-
263.
GALE WARNING UNTIL 11 PM EDT /10 PM CDT/ THIS EVENING FOR LSZ162.
LAKE MICHIGAN...
GALE WARNING UNTIL 8 AM EDT THURSDAY FOR LMZ221-248-250.
&&
$$
UPDATE...SRF
SHORT TERM...KF
LONG TERM...KC
AVIATION...SRF
MARINE...KC
HYDROLOGY...KF
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
1150 AM EDT WED SEP 10 2014
.UPDATE...
ISSUED AT 1149 AM EDT WED SEP 10 2014
GENERALLY MINOR TWEAKS TO THE GOING FORECAST...LARGELY WITH PINNING
DOWN THE LOCATIONS OF THE HEAVIEST PRECIPITATION AND THEN WINDS FOR
THIS AFTERNOON AND TONIGHT BEHIND THE LOW.
AS FOR THE RAIN...ESSENTIALLY SEEING TWO AREAS OF
PRECIPITATION...ONE OVER THE EAST ALIGNED WITH THE BROAD 850-500MB
WARM AIR ADVECTION LIFTING TO THE NORTHEAST AHEAD OF THE LOW
CENTERED OVER SOUTH CENTRAL WISCONSIN. EXPECT THAT AREA TO CONTINUE
PUSHING TO THE NORTHEAST THROUGH THE DAY AND LARGELY DEPARTING BY
LATE AFTERNOON. THE SECOND AREA IS FARTHEST TO THE WEST AND TIED TO
THE 850-700MB FGEN AREA TO THE NORTHWEST OF THE MID LEVEL LOW.
OBSERVER REPORTS INDICATE THIS AREA OF RAIN PRODUCING AROUND
0.5-0.75IN EVERY THREE HOURS AND THAT MATCHES DUAL POL INSTANTANEOUS
PRECIP RATES. ALTHOUGH THIS AREA HAS BEEN PIVOTING AND SLOW TO MOVE
THIS MORNING...IT IS EXPECTED TO SHIFT MORE TO THE EAST-NORTHEAST
THIS AFTERNOON AS THE LOW QUICKLY MOVES NORTHEAST THROUGH NORTHERN
LAKE MICHIGAN. STILL HAVE THE FLOOD WATCH IN PLACE AND THAT SEEMS
REASONABLE OVER THE WEST (WITH THE ADDED PRECIP FROM OVERNIGHT
PUSHING TOTALS OVER 2 INCHES IN SOME LOCATIONS). FROM
MARQUETTE/DICKINSON COUNTY EAST...THINK THE POTENTIAL FOR FLOODING
IS PRETTY LIMITED BUT WILL LEAVE WATCH IN PLACE AT THIS TIME.
FINALLY FOR WINDS...MAIN ADJUSTMENTS WERE FOR AREAS OVER THE EAST
AND NEAR LAKE MICHIGAN. EXPECT THE COMBINATION OF STRONG COLD AIR
ADVECTION BEHIND THE LOW AND QUICK PRESSURE RISE TO LEAD TO GALES
AND HAVE ISSUED A GALE WARNING FOR OUR LAKE MICHIGAN ZONES. DO HAVE
A LITTLE CONCERN THAT GUSTS WILL BE NEAR 40-45MPH BRIEFLY LATE THIS
AFTERNOON INTO THE EVENING NEAR THE LAKE SUPERIOR SHORELINE AND
POTENTIALLY AT TIMES ELSEWHERE INLAND. THE OTHER AREA WAS OVER THE
KEWEENAW PENINSULA...ALTHOUGH THE FORECAST WAS IN DECENT
SHAPE...LATEST OBS AT KP59 INDICATE WINDS GUSTING TO NEAR WIND
ADVISORY CRITERIA. WITH THE CENTRAL LAKE SUPERIOR BUOY GUSTING
ABOVE 40KTS AND OTHER SITES NEAR WIND ADVISORY CRITERIA...WILL
ISSUE A WIND ADVISORY FOR KEWEENAW AND NORTHERN HOUGHTON COUNTIES
THROUGH THE EVENING HOURS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 533 AM EDT WED SEP 10 2014
LIGHT TO AT TIME HEAVY RAIN CONTINUES TO FALL OVER THE W THIRD OF
UPPER MI THIS MORNING...ASSOCIATED WITH THE SFC TROUGH THAT PUSHED
OVERHEAD EARLY THIS MORNING THE 500MB SHORTWAVE CROSSING WI...AND
THE DEEPENING SFC LOW RIDING UP ALONG THE TROUGH NEARING FROM IA.
THE LATEST SATELLITE AND RUC ANALYSIS SHOWS THIS INITIAL N SWATH OF
MOISTURE EJECTING NE ACROSS THE CWA...WITH THE EFFECTS OF THE SW TO
NE 100KT 250MB JET NEARING FROM THE PLAINS. THE SECONDARY AREA OF
CLOUDS WILL BE IMPACTING THE E HALF OF THE CWA LATER THIS MORNING
AND INTO THE AFTERNOON HOURS. EXACT RAINFALL TOTALS REMAIN TRICKY AS
THERE ARE 2 AREAS OF THOUGHT. THE LATEST 06Z NAM PAINTS AN
ADDITIONAL 1-2IN OVER CENTRAL AND E UPPER MI LATE THIS MORNING
THROUGH EARLY THIS AFTERNOON. HOWEVER...THE 00Z GFS IS PUSHING MUCH
OF THE MOISTURE JUST TO OUR E. HAVE GONE WITH A MIDDLE OF THE ROAD
SOLUTION FOR THE MOMENT...KNOWING THAT CONVECTION TO THE SOUTH COULD
STILL HURT THE INFLOW OF MOISTURE UP OUR WAY. STILL...ADDITIONAL
SHOWERS CROSSING THE CWA THIS AFTERNOON WITH BE FACED WITH STIFF N
ONSHORE FLOW...RESULTING IN A SLOWER N PROGRESSION AND OVERALL
UPSLOPE ENHANCEMENT. SEE THE HYDROLOGY SECTION FOR MORE DETAILS
ABOUT PRECIPITATION FOR THE REST OF TODAY. RAIN/RAIN SHOWERS WILL
CONTINUE THROUGH TONIGHT...MAINLY ACROSS THOSE UPSLOPE AREAS OF
CENTRAL UPPER MI. ADDITIONAL RAINFALL MAY ADD UP TO 0.25IN OR MORE
ACROSS THE HURON MOUNTAINS. FCST MODELS ARE CONTINUING TO GO WITH
THE SFC LOW TRACKING ACROSS N LOWER MI LATE THIS AFTERNOON...BEFORE
EXITING INTO S ONTARIO AND W QUEBEC LATE THIS EVENING.
TEMPERATURES WILL REMAIN TRICKY...AS THEY FALL W AND STILL RISE A
COUPLE OF DEGREES AFTER SUNRISE E. KEPT THE WIND FCST VERY SIMILAR
TO THE LAST COUPLE OF DAYS...WITH N-NNW GUSTS NEARING 35KTS FROM
AROUND 18Z TODAY TO 08Z TONIGHT. AN SPS MAY BE NEEDED FOR THE W HALF
AND HIGHER TERRAIN OF THE KEWEENAW PENINSULA...OR LOW END WIND
ADVISORY TO HIGHLIGHT THE STRONG WINDS ON TOP OF SATURATED SOILS
THAT MAY MORE EASILY UPROOT TREES THANKS TO THE ABUNDANT LEAVES. AS
FOR THE OVERNIGHT HOURS...EXPECT SLOWLY DIMINISHING WINDS LATE AND
COLD AIR TO FILTER IN WITH 850MB TEMPS OF -2 TO +4C BY DAYBREAK
THURSDAY. DEPENDING ON HOW FAST RAIN CAN GET OUT OF THE INTERIOR
AREAS ALONG THE WI BORDER...MID 30S LOWS WILL NOT BE OUT OF THE
QUESTION.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 359 AM EDT WED SEP 10 2014
MAIN FCST CONCERNS IN THE LONG TERM FOCUS ON HOW QUICKLY ON THU CLDS
AND SHOWERS ASSOCIATED WITH THE WED LO PRES WL EXIT THE CWA...TEMPS
AND THE POTENTIAL FOR FROST ON THU NGT AND THEN ON POPS ACCOMPANYING
THE PASSAGE OF ANOTHER DISTURBANCE THRU THE LOWER LKS ON FRI INTO
SAT. SINCE AN UPR TROF WL DOMINATE ERN NAMERICA THRU NEXT WEEK...
EXPECT BLO NORMAL TEMPS TO PREVAIL DURING THE EXTENDED PERIOD.
THU...AS DEPARTING LO PRES OVER FAR SW QUEBEC AT 12Z THU SHIFTS TO
THE ENE...STEADY N LLVL FLOW IS PROGGED TO WEAKEN AND BECOME MORE
ACYC UNDER GENERAL DEEP LYR QVECTOR DVGC LEFT IN THE WAKE OF THE
EXITING SHRTWV AND RDG AXIS EXPANDING TO THE E OF SFC HI CENTER IN
THE NRN PLAINS. EXPECT PLENTY OF CLDS IN THE MRNG WITH SHOWERS
MAINLY NEAR LK SUP ASSOCIATED WITH CHILLY LINGERING CYC FLOW OVER
THE RELATIVELY WARM LK SUP WATERS. BUT WITH INCRSG SUBSIDENCE/ACYC
FLOW IN THE PRESENCE OF DAYTIME HEATING...EXPECT THE SHOWERS TO
DIMINISH AND THE CLD PATTERN TO SHIFT TO MORE INLAND SC COVERAGE
UNDER THE H85 THERMAL TROF AND SUBSIDENCE INVRN SINKING TOWARD
H85-9. H85 TEMPS IN THE ZERO TO -2C RANGE WL SUPPORT WELL BLO NORMAL
HI TEMPS MAINLY IN THE UPR 40S/50S...COOLEST OVER THE HIER TERRAIN
OF THE NW HALF.
THU NGT...UNDER BLDG HI PRES WITH LOSS OF DAYTIME HEATING...EXPECT
LINGERING SC TO DSPT IN THE EVNG AND GIVE WAY TO AT LEAST A PERIOD
OF MOCLR SKIES AND LGT WINDS. WITH PWAT UNDER 0.5 INCH...TEMPS
SHOULD FALL OFF STEADILY. THE ONE LIMITING FACTOR WL BE HOW QUICKLY
HI CLDS IN ADVANCE OF SHRTWV MOVING THRU THE NRN PLAINS WL INVADE
THE UPR LKS. SUSPECT THE COLD SPOTS OVER THE INTERIOR WL SEE TEMPS
FALLING AOB 32...BUT WL HOLD OFF ON ANY KIND OF FREEZE WATCH/FROST
HEADLINE GIVEN ACTIVE SHORT TERM...MARGINALLY LO ENUF FCST TEMPS AND
COVERAGE OF THOSE REALLY LO TEMPS UNDER SOME INCRSG HI CLDS.
FRI THRU SAT...ALTHOUGH THERE IS GOOD MODEL AGREEMENT ON THE TIMING
AND TRACK OF A FAIRLY VIGOROUS SHRTWV THAT IS FCST TO MOVE E FM THE
NRN ROCKIES ON THU AFTN THRU THE NCENTRAL PLAINS AND ACROSS THE
LOWER LKS FRI NGT/SAT...THERE ARE SOME FAIRLY LARGE DIFFERENCES IN
THE MSLP FIELDS AND QPF. THE 09/12Z ECWMF CONTINUES TO BE THE MODEL
THAT SHOWS THE MORE IMPRESSIVE PRES FALL. WITH A DEEPER SFC
REFLECTION...THE ECMWF ALSO SHOWS MORE EXPANSIVE MID LVL MSTR/PCPN
EXTENDING INTO ALL OF UPR MI DURING FRI NGT/SAT MRNG. GIVEN THE
POSITIVE TILT TO THE SHRTWV....EXPANSIVE HI PRES THAT IS FCST TO
EXTEND FM THE NRN PLAINS INTO THE UPR LKS IN ADVANCE OF THIS SHRTWV
AND DRY/STABLE NATURE OF THE ANTECEDENT AIRMASS /PWAT AOB 0.5 INCH
WITH STRONG SUBSIDENCE INVRN BTWN H8-7/...SUSPECT THE NON-ECMWF
MODELS SHOWING LESS SFC RESPONSE ARE ON THE RIGHT TRACK. HAVE THUS
CHOSEN TO MAINTAIN ONLY LO CHC POPS...HIEST OVER THE SRN CWA CLOSER
TO THE SHRTWV TRACK/AREA OF SHARPER DEEP LYR QVECTOR CNVGC. THICKER
CLDS/THESE POPS WL ARRIVE ON FRI AFTN AS THE DISTURBANCE SLIDES
INTO THE UPR MS RIVER VALLEY. ONCE THE SHRTWV PUSHES TO THE E ON SAT
MRNG...TRAILING SHRTWV RDG/DRIER AIRMASS WL BRING A RETURN TO DRY
WX/CLRG. WITH H85 TEMPS IN THE ZERO TO -2C RANGE DURING THIS
TIME...THE WX WL BE UNSEASONABLY COOL. IF SKIES CLR FAST ENUF LATE
FRI NGT...NOT OUT OF THE QUESTION THERE COULD BE SOME FROST OVER THE
INTERIOR W ARND SUNRISE ON SAT.
EXTENDED...AFTER A DRY PERIOD ASSOCIATED WITH SFC HI PRES PASSING
THRU THE LOWER LKS ON SAT NGT...ANOTHER CNDN SHRTWV DIGGING THRU THE
MEAN UPR TROF CENTERED OVER HUDSON BAY AND INTO THE NCENTRAL CONUS
WL BRING A CHC OF MORE SHOWERS FOR SUN THRU MON. THIS DISTURBANCE WL
BE MSTR DEPRIVED...SO NO HEAVY RA IS LIKELY. HI PRES MOVING E UNDER
THE RISING HGTS IN THE WAKE OF THIS DISTURBANCE SHOULD BRING A
RETURN OF DRY WX FOR TUE. WITH THE MEAN TROF IN PLACE...TEMPS ACRS
UPR MI WL AVG BLO NORMAL DURING THIS TIME.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 603 AM EDT WED SEP 10 2014
OFF AND ON RAIN AND BR/FG HAVE BEEN THE TREND OVERNIGHT. ONCE THE
RAIN HAS ENDED IFR TO VLIFR CEILINGS HAVE DEVELOPED. INCREASING
WINDS THIS MORNING SHOULD HELP LIMITED THE BR. HOWEVER...LOW
CEILINGS WILL STILL BE POSSIBLE WITH ANY MODERATE RAIN THAT DEVELOPS.
LOOKING AT UPSTREAM CONDITIONS...LIFR CEILINGS WILL LIKELY DOMINATE
THE DAY AT IWD AND CMX. STEADIER RAIN WILL MOVE INTO SAW OVER THE
NEXT FEW HOURS. LOOK FOR STRONG WINDS DEVELOPING W TO E THIS
MORNING...WITH GUSTS OVER 30KTS POSSIBLE AT CMX FROM 19Z THIS
AFTERNOON TO 04Z THURSDAY. IWD MAY BE LIMITED TO GUSTS AROUND
20KTS...WHILE THE N WINDS GUST BETWEEN 25 AND 30KTS FROM 21Z TO 09Z
THURSDAY AT SAW AND KEEP LAKE EFFECT/ENHANCED RAIN SHOWERS GOING
THROUGH 12Z THURSDAY. DRIER AIR WILL SLOWLY WORK IN FROM THE
W...WITH ONLY A CHANCE OF SHOWERS AT CMX AND IWD BY DAYBREAK
THURSDAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 AM EDT WED SEP 10 2014
AS A DEEP LO PRES MOVES NE THRU THE UPPER MIDWEST AND ACROSS
NORTHERN LOWER MI THIS EVENING ON ITS WAY INTO SE CANADA
TONIGHT...THE NE GALES AFFECTING WESTERN LAKE SUPERIOR WILL SPREAD E
OVER THE REST OF THE LAKE. EXPECT NNE GALES AS HI AS 40-45 KTS TODAY
INTO TONIGHT BEFORE THE LO PRES SHIFTS FAR ENOUGH TO THE E AND THE
GALES DIMINISH W TO E TONIGHT. AS HI PRES BUILDS TOWARD LAKE SUPERIOR
FROM THE PLAINS ON THU...LINGERING N WINDS UP TO 25-30 KTS IN THE
MORNING WILL DIMINISH W-E TO UNDER 15-20 KTS BY THE EVENING.
RELATIVELY LIGHT WINDS UNDER 20 KTS WILL THEN DOMINATE THRU THE
WEEKEND UNDER A RELATIVELY WEAK PRES GRADIENT.
&&
.HYDROLOGY...
ISSUED AT 426 AM EDT WED SEP 10 2014
RAINFALL OVER THE W THIRD OF UPPER MI HAS BEEN CONVECTIVELY
ENHANCED...WITH RAINFALL RATES BRIEFLY RISING TO NEAR 6IN PER HOUR.
WITH THE QUICK MOVEMENT TO THE N JUST OVER 20KTS THAT AMOUNT WAS NOT
REALIZED. RADAR ESTIMATES THROUGH 08Z HAVE THE HIGHEST AMOUNTS OVER
NW GOGEBIC AND ALONG THE E ONTONAGON/W HOUGHTON COUNTIES...WITH 1.5
TO 2.25IN. SOME LOCAL RIVERS CONTINUE TO RESPOND TO THE RAINFALL A
FEW DAYS AGO...AND ARE RISING AT AN INCREASED RATE DO TO THE CURRENT
RAIN. SPECIFICALLY THIS INCLUDES THE SOUTH BRANCH OF THE ONTONAGON
RIVER AT EWEN /WHICH GIVEN THE TREND WILL SEE A SLOW RISE FOR THE
NEXT SEVERAL DAYS/. THE MIDDLE BRANCH OF THE ONTONAGON RIVER AT
PAULDING IS ALSO SLOWLY ON THE RISE.
OTHERWISE AN AVERAGED 0.5IN HAS FALLEN W OF A LINE FROM
IRON RIVER TO BARAGA. LITTLE RAIN HAS FALLEN E OF THIS LINE...WHICH
WILL CHANGE OVER THE NEXT COUPLE OF HRS AS ADDITIONAL SHOWERS NEAR
FROM WI. THUNDERSTORMS ARE MINIMAL OVER WI...AND PRECIP IS SLOWER
THAN ORIGINALLY ANTICIPATED. HAVE BACKED OFF ON THE STORM TOTAL
PRECIP OVER THE E THIRD OF THE FCST AREA AS A RESULT. EXPECT THE
TRADITIONAL URBAN/SMALL STREAM FLOODING TO BE A SIGNIFICANT
POSSIBILITY IN THE TYPICAL POOR DRAINAGE AREAS OF ESC IF A PERIOD OF
HEAVIER DOWNPOURS DEVELOP WITH RAINFALL RATES CLOSE TO AN 0.5-1.0
INCH PER HOUR. N CNTRL UPPER MI WILL STILL LIKELY SEE SOME UPSLOPE
LAKE ENHANCEMENT TODAY-TONIGHT. THE FLOOD WATCH REMAINS POSTED FOR
MUCH OF W AND CENTRAL UPPER MI FOR TODAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FLOOD WATCH UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR
MIZ001>006-009>013-084.
LAKE SUPERIOR...
GALE WARNING FROM 8 PM THIS EVENING TO 8 AM EDT THURSDAY FOR
LSZ251-267.
GALE WARNING UNTIL 5 AM EDT THURSDAY FOR LSZ246>250-265-266.
GALE WARNING UNTIL 4 AM EDT THURSDAY FOR LSZ243>245-264.
GALE WARNING UNTIL 2 AM EDT /1 AM CDT/ THURSDAY FOR LSZ240>242-
263.
GALE WARNING UNTIL 11 PM EDT /10 PM CDT/ THIS EVENING FOR LSZ162.
LAKE MICHIGAN...
GALE WARNING UNTIL 8 AM EDT THURSDAY FOR LMZ221-248-250.
&&
$$
UPDATE...SRF
SHORT TERM...KF
LONG TERM...KC
AVIATION...KF
MARINE...KC
HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
602 AM EDT WED SEP 10 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 533 AM EDT WED SEP 10 2014
LIGHT TO AT TIME HEAVY RAIN CONTINUES TO FALL OVER THE W THIRD OF
UPPER MI THIS MORNING...ASSOCIATED WITH THE SFC TROUGH THAT PUSHED
OVERHEAD EARLY THIS MORNING THE 500MB SHORTWAVE CROSSING WI...AND
THE DEEPENING SFC LOW RIDING UP ALONG THE TROUGH NEARING FROM IA.
THE LATEST SATELLITE AND RUC ANALYSIS SHOWS THIS INITIAL N SWATH OF
MOISTURE EJECTING NE ACROSS THE CWA...WITH THE EFFECTS OF THE SW TO
NE 100KT 250MB JET NEARING FROM THE PLAINS. THE SECONDARY AREA OF
CLOUDS WILL BE IMPACTING THE E HALF OF THE CWA LATER THIS MORNING
AND INTO THE AFTERNOON HOURS. EXACT RAINFALL TOTALS REMAIN TRICKY AS
THERE ARE 2 AREAS OF THOUGHT. THE LATEST 06Z NAM PAINTS AN
ADDITIONAL 1-2IN OVER CENTRAL AND E UPPER MI LATE THIS MORNING
THROUGH EARLY THIS AFTERNOON. HOWEVER...THE 00Z GFS IS PUSHING MUCH
OF THE MOISTURE JUST TO OUR E. HAVE GONE WITH A MIDDLE OF THE ROAD
SOLUTION FOR THE MOMENT...KNOWING THAT CONVECTION TO THE SOUTH COULD
STILL HURT THE INFLOW OF MOISTURE UP OUR WAY. STILL...ADDITIONAL
SHOWERS CROSSING THE CWA THIS AFTERNOON WITH BE FACED WITH STIFF N
ONSHORE FLOW...RESULTING IN A SLOWER N PROGRESSION AND OVERALL
UPSLOPE ENHANCEMENT. SEE THE HYDROLOGY SECTION FOR MORE DETAILS
ABOUT PRECIPITATION FOR THE REST OF TODAY. RAIN/RAIN SHOWERS WILL
CONTINUE THROUGH TONIGHT...MAINLY ACROSS THOSE UPSLOPE AREAS OF
CENTRAL UPPER MI. ADDITIONAL RAINFALL MAY ADD UP TO 0.25IN OR MORE
ACROSS THE HURON MOUNTAINS. FCST MODELS ARE CONTINUING TO GO WITH
THE SFC LOW TRACKING ACROSS N LOWER MI LATE THIS AFTERNOON...BEFORE
EXITING INTO S ONTARIO AND W QUEBEC LATE THIS EVENING.
TEMPERATURES WILL REMAIN TRICKY...AS THEY FALL W AND STILL RISE A
COUPLE OF DEGREES AFTER SUNRISE E. KEPT THE WIND FCST VERY SIMILAR
TO THE LAST COUPLE OF DAYS...WITH N-NNW GUSTS NEARING 35KTS FROM
AROUND 18Z TODAY TO 08Z TONIGHT. AN SPS MAY BE NEEDED FOR THE W HALF
AND HIGHER TERRAIN OF THE KEWEENAW PENINSULA...OR LOW END WIND
ADVISORY TO HIGHLIGHT THE STRONG WINDS ON TOP OF SATURATED SOILS
THAT MAY MORE EASILY UPROOT TREES THANKS TO THE ABUNDANT LEAVES. AS
FOR THE OVERNIGHT HOURS...EXPECT SLOWLY DIMINISHING WINDS LATE AND
COLD AIR TO FILTER IN WITH 850MB TEMPS OF -2 TO +4C BY DAYBREAK
THURSDAY. DEPENDING ON HOW FAST RAIN CAN GET OUT OF THE INTERIOR
AREAS ALONG THE WI BORDER...MID 30S LOWS WILL NOT BE OUT OF THE
QUESTION.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 359 AM EDT WED SEP 10 2014
MAIN FCST CONCERNS IN THE LONG TERM FOCUS ON HOW QUICKLY ON THU CLDS
AND SHOWERS ASSOCIATED WITH THE WED LO PRES WL EXIT THE CWA...TEMPS
AND THE POTENTIAL FOR FROST ON THU NGT AND THEN ON POPS ACCOMPANYING
THE PASSAGE OF ANOTHER DISTURBANCE THRU THE LOWER LKS ON FRI INTO
SAT. SINCE AN UPR TROF WL DOMINATE ERN NAMERICA THRU NEXT WEEK...
EXPECT BLO NORMAL TEMPS TO PREVAIL DURING THE EXTENDED PERIOD.
THU...AS DEPARTING LO PRES OVER FAR SW QUEBEC AT 12Z THU SHIFTS TO
THE ENE...STEADY N LLVL FLOW IS PROGGED TO WEAKEN AND BECOME MORE
ACYC UNDER GENERAL DEEP LYR QVECTOR DVGC LEFT IN THE WAKE OF THE
EXITING SHRTWV AND RDG AXIS EXPANDING TO THE E OF SFC HI CENTER IN
THE NRN PLAINS. EXPECT PLENTY OF CLDS IN THE MRNG WITH SHOWERS
MAINLY NEAR LK SUP ASSOCIATED WITH CHILLY LINGERING CYC FLOW OVER
THE RELATIVELY WARM LK SUP WATERS. BUT WITH INCRSG SUBSIDENCE/ACYC
FLOW IN THE PRESENCE OF DAYTIME HEATING...EXPECT THE SHOWERS TO
DIMINISH AND THE CLD PATTERN TO SHIFT TO MORE INLAND SC COVERAGE
UNDER THE H85 THERMAL TROF AND SUBSIDENCE INVRN SINKING TOWARD
H85-9. H85 TEMPS IN THE ZERO TO -2C RANGE WL SUPPORT WELL BLO NORMAL
HI TEMPS MAINLY IN THE UPR 40S/50S...COOLEST OVER THE HIER TERRAIN
OF THE NW HALF.
THU NGT...UNDER BLDG HI PRES WITH LOSS OF DAYTIME HEATING...EXPECT
LINGERING SC TO DSPT IN THE EVNG AND GIVE WAY TO AT LEAST A PERIOD
OF MOCLR SKIES AND LGT WINDS. WITH PWAT UNDER 0.5 INCH...TEMPS
SHOULD FALL OFF STEADILY. THE ONE LIMITING FACTOR WL BE HOW QUICKLY
HI CLDS IN ADVANCE OF SHRTWV MOVING THRU THE NRN PLAINS WL INVADE
THE UPR LKS. SUSPECT THE COLD SPOTS OVER THE INTERIOR WL SEE TEMPS
FALLING AOB 32...BUT WL HOLD OFF ON ANY KIND OF FREEZE WATCH/FROST
HEADLINE GIVEN ACTIVE SHORT TERM...MARGINALLY LO ENUF FCST TEMPS AND
COVERAGE OF THOSE REALLY LO TEMPS UNDER SOME INCRSG HI CLDS.
FRI THRU SAT...ALTHOUGH THERE IS GOOD MODEL AGREEMENT ON THE TIMING
AND TRACK OF A FAIRLY VIGOROUS SHRTWV THAT IS FCST TO MOVE E FM THE
NRN ROCKIES ON THU AFTN THRU THE NCENTRAL PLAINS AND ACROSS THE
LOWER LKS FRI NGT/SAT...THERE ARE SOME FAIRLY LARGE DIFFERENCES IN
THE MSLP FIELDS AND QPF. THE 09/12Z ECWMF CONTINUES TO BE THE MODEL
THAT SHOWS THE MORE IMPRESSIVE PRES FALL. WITH A DEEPER SFC
REFLECTION...THE ECMWF ALSO SHOWS MORE EXPANSIVE MID LVL MSTR/PCPN
EXTENDING INTO ALL OF UPR MI DURING FRI NGT/SAT MRNG. GIVEN THE
POSITIVE TILT TO THE SHRTWV....EXPANSIVE HI PRES THAT IS FCST TO
EXTEND FM THE NRN PLAINS INTO THE UPR LKS IN ADVANCE OF THIS SHRTWV
AND DRY/STABLE NATURE OF THE ANTECEDENT AIRMASS /PWAT AOB 0.5 INCH
WITH STRONG SUBSIDENCE INVRN BTWN H8-7/...SUSPECT THE NON-ECMWF
MODELS SHOWING LESS SFC RESPONSE ARE ON THE RIGHT TRACK. HAVE THUS
CHOSEN TO MAINTAIN ONLY LO CHC POPS...HIEST OVER THE SRN CWA CLOSER
TO THE SHRTWV TRACK/AREA OF SHARPER DEEP LYR QVECTOR CNVGC. THICKER
CLDS/THESE POPS WL ARRIVE ON FRI AFTN AS THE DISTURBANCE SLIDES
INTO THE UPR MS RIVER VALLEY. ONCE THE SHRTWV PUSHES TO THE E ON SAT
MRNG...TRAILING SHRTWV RDG/DRIER AIRMASS WL BRING A RETURN TO DRY
WX/CLRG. WITH H85 TEMPS IN THE ZERO TO -2C RANGE DURING THIS
TIME...THE WX WL BE UNSEASONABLY COOL. IF SKIES CLR FAST ENUF LATE
FRI NGT...NOT OUT OF THE QUESTION THERE COULD BE SOME FROST OVER THE
INTERIOR W ARND SUNRISE ON SAT.
EXTENDED...AFTER A DRY PERIOD ASSOCIATED WITH SFC HI PRES PASSING
THRU THE LOWER LKS ON SAT NGT...ANOTHER CNDN SHRTWV DIGGING THRU THE
MEAN UPR TROF CENTERED OVER HUDSON BAY AND INTO THE NCENTRAL CONUS
WL BRING A CHC OF MORE SHOWERS FOR SUN THRU MON. THIS DISTURBANCE WL
BE MSTR DEPRIVED...SO NO HEAVY RA IS LIKELY. HI PRES MOVING E UNDER
THE RISING HGTS IN THE WAKE OF THIS DISTURBANCE SHOULD BRING A
RETURN OF DRY WX FOR TUE. WITH THE MEAN TROF IN PLACE...TEMPS ACRS
UPR MI WL AVG BLO NORMAL DURING THIS TIME.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 603 AM EDT WED SEP 10 2014
OFF AND ON RAIN AND BR/FG HAVE BEEN THE TREND OVERNIGHT. ONCE THE
RAIN HAS ENDED IFR TO VLIFR CEILINGS HAVE DEVELOPED. INCREASING
WINDS THIS MORNING SHOULD HELP LIMITED THE BR. HOWEVER...LOW
CEILINGS WILL STILL BE POSSIBLE WITH ANY MODERATE RAIN THAT DEVELOPS.
LOOKING AT UPSTREAM CONDITIONS...LIFR CEILINGS WILL LIKELY DOMINATE
THE DAY AT IWD AND CMX. STEADIER RAIN WILL MOVE INTO SAW OVER THE
NEXT FEW HOURS. LOOK FOR STRONG WINDS DEVELOPING W TO E THIS
MORNING...WITH GUSTS OVER 30KTS POSSIBLE AT CMX FROM 19Z THIS
AFTERNOON TO 04Z THURSDAY. IWD MAY BE LIMITED TO GUSTS AROUND
20KTS...WHILE THE N WINDS GUST BETWEEN 25 AND 30KTS FROM 21Z TO 09Z
THURSDAY AT SAW AND KEEP LAKE EFFECT/ENHANCED RAIN SHOWERS GOING
THROUGH 12Z THURSDAY. DRIER AIR WILL SLOWLY WORK IN FROM THE
W...WITH ONLY A CHANCE OF SHOWERS AT CMX AND IWD BY DAYBREAK
THURSDAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 AM EDT WED SEP 10 2014
AS A DEEP LO PRES MOVES NE THRU THE UPPER MIDWEST AND ACROSS
NORTHERN LOWER MI THIS EVENING ON ITS WAY INTO SE CANADA
TONIGHT...THE NE GALES AFFECTING WESTERN LAKE SUPERIOR WILL SPREAD E
OVER THE REST OF THE LAKE. EXPECT NNE GALES AS HI AS 40-45 KTS TODAY
INTO TONIGHT BEFORE THE LO PRES SHIFTS FAR ENOUGH TO THE E AND THE
GALES DIMINISH W TO E TONIGHT. AS HI PRES BUILDS TOWARD LAKE SUPERIOR
FROM THE PLAINS ON THU...LINGERING N WINDS UP TO 25-30 KTS IN THE
MORNING WILL DIMINISH W-E TO UNDER 15-20 KTS BY THE EVENING.
RELATIVELY LIGHT WINDS UNDER 20 KTS WILL THEN DOMINATE THRU THE
WEEKEND UNDER A RELATIVELY WEAK PRES GRADIENT.
&&
.HYDROLOGY...
ISSUED AT 426 AM EDT WED SEP 10 2014
RAINFALL OVER THE W THIRD OF UPPER MI HAS BEEN CONVECTIVELY
ENHANCED...WITH RAINFALL RATES BRIEFLY RISING TO NEAR 6IN PER HOUR.
WITH THE QUICK MOVEMENT TO THE N JUST OVER 20KTS THAT AMOUNT WAS NOT
REALIZED. RADAR ESTIMATES THROUGH 08Z HAVE THE HIGHEST AMOUNTS OVER
NW GOGEBIC AND ALONG THE E ONTONAGON/W HOUGHTON COUNTIES...WITH 1.5
TO 2.25IN. SOME LOCAL RIVERS CONTINUE TO RESPOND TO THE RAINFALL A
FEW DAYS AGO...AND ARE RISING AT AN INCREASED RATE DO TO THE CURRENT
RAIN. SPECIFICALLY THIS INCLUDES THE SOUTH BRANCH OF THE ONTONAGON
RIVER AT EWEN /WHICH GIVEN THE TREND WILL SEE A SLOW RISE FOR THE
NEXT SEVERAL DAYS/. THE MIDDLE BRANCH OF THE ONTONAGON RIVER AT
PAULDING IS ALSO SLOWLY ON THE RISE.
OTHERWISE AN AVERAGED 0.5IN HAS FALLEN W OF A LINE FROM
IRON RIVER TO BARAGA. LITTLE RAIN HAS FALLEN E OF THIS LINE...WHICH
WILL CHANGE OVER THE NEXT COUPLE OF HRS AS ADDITIONAL SHOWERS NEAR
FROM WI. THUNDERSTORMS ARE MINIMAL OVER WI...AND PRECIP IS SLOWER
THAN ORIGINALLY ANTICIPATED. HAVE BACKED OFF ON THE STORM TOTAL
PRECIP OVER THE E THIRD OF THE FCST AREA AS A RESULT. EXPECT THE
TRADITIONAL URBAN/SMALL STREAM FLOODING TO BE A SIGNIFICANT
POSSIBILITY IN THE TYPICAL POOR DRAINAGE AREAS OF ESC IF A PERIOD OF
HEAVIER DOWNPOURS DEVELOP WITH RAINFALL RATES CLOSE TO AN 0.5-1.0
INCH PER HOUR. N CNTRL UPPER MI WILL STILL LIKELY SEE SOME UPSLOPE
LAKE ENHANCEMENT TODAY-TONIGHT. THE FLOOD WATCH REMAINS POSTED FOR
MUCH OF W AND CENTRAL UPPER MI FOR TODAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FLOOD WATCH THROUGH THIS EVENING FOR MIZ001>006-009>013-084.
LAKE SUPERIOR...
GALE WARNING FROM 8 PM THIS EVENING TO 8 AM EDT THURSDAY FOR
LSZ251-267.
GALE WARNING FROM 2 PM THIS AFTERNOON TO 5 AM EDT THURSDAY FOR
LSZ246>250-265-266.
GALE WARNING UNTIL 4 AM EDT THURSDAY FOR LSZ243>245-264.
GALE WARNING UNTIL 2 AM EDT /1 AM CDT/ THURSDAY FOR LSZ240>242-
263.
GALE WARNING UNTIL 11 PM EDT /10 PM CDT/ THIS EVENING FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KF
LONG TERM...KC
AVIATION...KF
MARINE...KC
HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
534 AM EDT WED SEP 10 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 533 AM EDT WED SEP 10 2014
LIGHT TO AT TIME HEAVY RAIN CONTINUES TO FALL OVER THE W THIRD OF
UPPER MI THIS MORNING...ASSOCIATED WITH THE SFC TROUGH THAT PUSHED
OVERHEAD EARLY THIS MORNING THE 500MB SHORTWAVE CROSSING WI...AND
THE DEEPENING SFC LOW RIDING UP ALONG THE TROUGH NEARING FROM IA.
THE LATEST SATELLITE AND RUC ANALYSIS SHOWS THIS INITIAL N SWATH OF
MOISTURE EJECTING NE ACROSS THE CWA...WITH THE EFFECTS OF THE SW TO
NE 100KT 250MB JET NEARING FROM THE PLAINS. THE SECONDARY AREA OF
CLOUDS WILL BE IMPACTING THE E HALF OF THE CWA LATER THIS MORNING
AND INTO THE AFTERNOON HOURS. EXACT RAINFALL TOTALS REMAIN TRICKY AS
THERE ARE 2 AREAS OF THOUGHT. THE LATEST 06Z NAM PAINTS AN
ADDITIONAL 1-2IN OVER CENTRAL AND E UPPER MI LATE THIS MORNING
THROUGH EARLY THIS AFTERNOON. HOWEVER...THE 00Z GFS IS PUSHING MUCH
OF THE MOISTURE JUST TO OUR E. HAVE GONE WITH A MIDDLE OF THE ROAD
SOLUTION FOR THE MOMENT...KNOWING THAT CONVECTION TO THE SOUTH COULD
STILL HURT THE INFLOW OF MOISTURE UP OUR WAY. STILL...ADDITIONAL
SHOWERS CROSSING THE CWA THIS AFTERNOON WITH BE FACED WITH STIFF N
ONSHORE FLOW...RESULTING IN A SLOWER N PROGRESSION AND OVERALL
UPSLOPE ENHANCEMENT. SEE THE HYDROLOGY SECTION FOR MORE DETAILS
ABOUT PRECIPITATION FOR THE REST OF TODAY. RAIN/RAIN SHOWERS WILL
CONTINUE THROUGH TONIGHT...MAINLY ACROSS THOSE UPSLOPE AREAS OF
CENTRAL UPPER MI. ADDITIONAL RAINFALL MAY ADD UP TO 0.25IN OR MORE
ACROSS THE HURON MOUNTAINS. FCST MODELS ARE CONTINUING TO GO WITH
THE SFC LOW TRACKING ACROSS N LOWER MI LATE THIS AFTERNOON...BEFORE
EXITING INTO S ONTARIO AND W QUEBEC LATE THIS EVENING.
TEMPERATURES WILL REMAIN TRICKY...AS THEY FALL W AND STILL RISE A
COUPLE OF DEGREES AFTER SUNRISE E. KEPT THE WIND FCST VERY SIMILAR
TO THE LAST COUPLE OF DAYS...WITH N-NNW GUSTS NEARING 35KTS FROM
AROUND 18Z TODAY TO 08Z TONIGHT. AN SPS MAY BE NEEDED FOR THE W HALF
AND HIGHER TERRAIN OF THE KEWEENAW PENINSULA...OR LOW END WIND
ADVISORY TO HIGHLIGHT THE STRONG WINDS ON TOP OF SATURATED SOILS
THAT MAY MORE EASILY UPROOT TREES THANKS TO THE ABUNDANT LEAVES. AS
FOR THE OVERNIGHT HOURS...EXPECT SLOWLY DIMINISHING WINDS LATE AND
COLD AIR TO FILTER IN WITH 850MB TEMPS OF -2 TO +4C BY DAYBREAK
THURSDAY. DEPENDING ON HOW FAST RAIN CAN GET OUT OF THE INTERIOR
AREAS ALONG THE WI BORDER...MID 30S LOWS WILL NOT BE OUT OF THE
QUESTION.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 359 AM EDT WED SEP 10 2014
MAIN FCST CONCERNS IN THE LONG TERM FOCUS ON HOW QUICKLY ON THU CLDS
AND SHOWERS ASSOCIATED WITH THE WED LO PRES WL EXIT THE CWA...TEMPS
AND THE POTENTIAL FOR FROST ON THU NGT AND THEN ON POPS ACCOMPANYING
THE PASSAGE OF ANOTHER DISTURBANCE THRU THE LOWER LKS ON FRI INTO
SAT. SINCE AN UPR TROF WL DOMINATE ERN NAMERICA THRU NEXT WEEK...
EXPECT BLO NORMAL TEMPS TO PREVAIL DURING THE EXTENDED PERIOD.
THU...AS DEPARTING LO PRES OVER FAR SW QUEBEC AT 12Z THU SHIFTS TO
THE ENE...STEADY N LLVL FLOW IS PROGGED TO WEAKEN AND BECOME MORE
ACYC UNDER GENERAL DEEP LYR QVECTOR DVGC LEFT IN THE WAKE OF THE
EXITING SHRTWV AND RDG AXIS EXPANDING TO THE E OF SFC HI CENTER IN
THE NRN PLAINS. EXPECT PLENTY OF CLDS IN THE MRNG WITH SHOWERS
MAINLY NEAR LK SUP ASSOCIATED WITH CHILLY LINGERING CYC FLOW OVER
THE RELATIVELY WARM LK SUP WATERS. BUT WITH INCRSG SUBSIDENCE/ACYC
FLOW IN THE PRESENCE OF DAYTIME HEATING...EXPECT THE SHOWERS TO
DIMINISH AND THE CLD PATTERN TO SHIFT TO MORE INLAND SC COVERAGE
UNDER THE H85 THERMAL TROF AND SUBSIDENCE INVRN SINKING TOWARD
H85-9. H85 TEMPS IN THE ZERO TO -2C RANGE WL SUPPORT WELL BLO NORMAL
HI TEMPS MAINLY IN THE UPR 40S/50S...COOLEST OVER THE HIER TERRAIN
OF THE NW HALF.
THU NGT...UNDER BLDG HI PRES WITH LOSS OF DAYTIME HEATING...EXPECT
LINGERING SC TO DSPT IN THE EVNG AND GIVE WAY TO AT LEAST A PERIOD
OF MOCLR SKIES AND LGT WINDS. WITH PWAT UNDER 0.5 INCH...TEMPS
SHOULD FALL OFF STEADILY. THE ONE LIMITING FACTOR WL BE HOW QUICKLY
HI CLDS IN ADVANCE OF SHRTWV MOVING THRU THE NRN PLAINS WL INVADE
THE UPR LKS. SUSPECT THE COLD SPOTS OVER THE INTERIOR WL SEE TEMPS
FALLING AOB 32...BUT WL HOLD OFF ON ANY KIND OF FREEZE WATCH/FROST
HEADLINE GIVEN ACTIVE SHORT TERM...MARGINALLY LO ENUF FCST TEMPS AND
COVERAGE OF THOSE REALLY LO TEMPS UNDER SOME INCRSG HI CLDS.
FRI THRU SAT...ALTHOUGH THERE IS GOOD MODEL AGREEMENT ON THE TIMING
AND TRACK OF A FAIRLY VIGOROUS SHRTWV THAT IS FCST TO MOVE E FM THE
NRN ROCKIES ON THU AFTN THRU THE NCENTRAL PLAINS AND ACROSS THE
LOWER LKS FRI NGT/SAT...THERE ARE SOME FAIRLY LARGE DIFFERENCES IN
THE MSLP FIELDS AND QPF. THE 09/12Z ECWMF CONTINUES TO BE THE MODEL
THAT SHOWS THE MORE IMPRESSIVE PRES FALL. WITH A DEEPER SFC
REFLECTION...THE ECMWF ALSO SHOWS MORE EXPANSIVE MID LVL MSTR/PCPN
EXTENDING INTO ALL OF UPR MI DURING FRI NGT/SAT MRNG. GIVEN THE
POSITIVE TILT TO THE SHRTWV....EXPANSIVE HI PRES THAT IS FCST TO
EXTEND FM THE NRN PLAINS INTO THE UPR LKS IN ADVANCE OF THIS SHRTWV
AND DRY/STABLE NATURE OF THE ANTECEDENT AIRMASS /PWAT AOB 0.5 INCH
WITH STRONG SUBSIDENCE INVRN BTWN H8-7/...SUSPECT THE NON-ECMWF
MODELS SHOWING LESS SFC RESPONSE ARE ON THE RIGHT TRACK. HAVE THUS
CHOSEN TO MAINTAIN ONLY LO CHC POPS...HIEST OVER THE SRN CWA CLOSER
TO THE SHRTWV TRACK/AREA OF SHARPER DEEP LYR QVECTOR CNVGC. THICKER
CLDS/THESE POPS WL ARRIVE ON FRI AFTN AS THE DISTURBANCE SLIDES
INTO THE UPR MS RIVER VALLEY. ONCE THE SHRTWV PUSHES TO THE E ON SAT
MRNG...TRAILING SHRTWV RDG/DRIER AIRMASS WL BRING A RETURN TO DRY
WX/CLRG. WITH H85 TEMPS IN THE ZERO TO -2C RANGE DURING THIS
TIME...THE WX WL BE UNSEASONABLY COOL. IF SKIES CLR FAST ENUF LATE
FRI NGT...NOT OUT OF THE QUESTION THERE COULD BE SOME FROST OVER THE
INTERIOR W ARND SUNRISE ON SAT.
EXTENDED...AFTER A DRY PERIOD ASSOCIATED WITH SFC HI PRES PASSING
THRU THE LOWER LKS ON SAT NGT...ANOTHER CNDN SHRTWV DIGGING THRU THE
MEAN UPR TROF CENTERED OVER HUDSON BAY AND INTO THE NCENTRAL CONUS
WL BRING A CHC OF MORE SHOWERS FOR SUN THRU MON. THIS DISTURBANCE WL
BE MSTR DEPRIVED...SO NO HEAVY RA IS LIKELY. HI PRES MOVING E UNDER
THE RISING HGTS IN THE WAKE OF THIS DISTURBANCE SHOULD BRING A
RETURN OF DRY WX FOR TUE. WITH THE MEAN TROF IN PLACE...TEMPS ACRS
UPR MI WL AVG BLO NORMAL DURING THIS TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1148 PM EDT TUE SEP 9 2014
NNE WIND SHIFT BEHIND A COLD FRONT MOVED BROUGHT LIFR CLOUDS INTO
IWD/CMX LAST EVENING. A FEW SHRA/TSRA HAVE ALSO POPPED UP ALONG
FRONTAL BOUNDARY MAINLY AT IWD. AS A STRONGER DISTURBANCE MOVES NEWD
AND THE MOIST LYR DEEPENS...WIDESPREAD RAIN WILL DEVELOP FROM SW TO
NE AND KEEPING CONDITIONS LIFR AT IWD/CMX INTO MUCH OF WED. SINCE
THE FROPA WL OCCUR LATER AT SAW...THE TRANSITION TO MVFR WILL NOT
OCCUR UNTIL AROUND 08Z. BY LATE TONIGHT INTO WED MORNING LIFR
CONDITIONS WILL PREVAIL AT SAW AS WELL WITH MODERATE TO OCNLY HEAVY
RAIN AND GUSTY NE-N WINDS DEVELOPING BY LATE MORNING/AFTERNOON. NE-N
WIND WILL GUST OVER 30 KT AT KCMX AND POSSIBLY AOA 25 KTS AT KSAW
AND IWD BY LATE MORNING/MIDDAY WED.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 AM EDT WED SEP 10 2014
AS A DEEP LO PRES MOVES NE THRU THE UPPER MIDWEST AND ACROSS
NORTHERN LOWER MI THIS EVENING ON ITS WAY INTO SE CANADA
TONIGHT...THE NE GALES AFFECTING WESTERN LAKE SUPERIOR WILL SPREAD E
OVER THE REST OF THE LAKE. EXPECT NNE GALES AS HI AS 40-45 KTS TODAY
INTO TONIGHT BEFORE THE LO PRES SHIFTS FAR ENOUGH TO THE E AND THE
GALES DIMINISH W TO E TONIGHT. AS HI PRES BUILDS TOWARD LAKE SUPERIOR
FROM THE PLAINS ON THU...LINGERING N WINDS UP TO 25-30 KTS IN THE
MORNING WILL DIMINISH W-E TO UNDER 15-20 KTS BY THE EVENING.
RELATIVELY LIGHT WINDS UNDER 20 KTS WILL THEN DOMINATE THRU THE
WEEKEND UNDER A RELATIVELY WEAK PRES GRADIENT.
&&
.HYDROLOGY...
ISSUED AT 426 AM EDT WED SEP 10 2014
RAINFALL OVER THE W THIRD OF UPPER MI HAS BEEN CONVECTIVELY
ENHANCED...WITH RAINFALL RATES BRIEFLY RISING TO NEAR 6IN PER HOUR.
WITH THE QUICK MOVEMENT TO THE N JUST OVER 20KTS THAT AMOUNT WAS NOT
REALIZED. RADAR ESTIMATES THROUGH 08Z HAVE THE HIGHEST AMOUNTS OVER
NW GOGEBIC AND ALONG THE E ONTONAGON/W HOUGHTON COUNTIES...WITH 1.5
TO 2.25IN. SOME LOCAL RIVERS CONTINUE TO RESPOND TO THE RAINFALL A
FEW DAYS AGO...AND ARE RISING AT AN INCREASED RATE DO TO THE CURRENT
RAIN. SPECIFICALLY THIS INCLUDES THE SOUTH BRANCH OF THE ONTONAGON
RIVER AT EWEN /WHICH GIVEN THE TREND WILL SEE A SLOW RISE FOR THE
NEXT SEVERAL DAYS/. THE MIDDLE BRANCH OF THE ONTONAGON RIVER AT
PAULDING IS ALSO SLOWLY ON THE RISE.
OTHERWISE AN AVERAGED 0.5IN HAS FALLEN W OF A LINE FROM
IRON RIVER TO BARAGA. LITTLE RAIN HAS FALLEN E OF THIS LINE...WHICH
WILL CHANGE OVER THE NEXT COUPLE OF HRS AS ADDITIONAL SHOWERS NEAR
FROM WI. THUNDERSTORMS ARE MINIMAL OVER WI...AND PRECIP IS SLOWER
THAN ORIGINALLY ANTICIPATED. HAVE BACKED OFF ON THE STORM TOTAL
PRECIP OVER THE E THIRD OF THE FCST AREA AS A RESULT. EXPECT THE
TRADITIONAL URBAN/SMALL STREAM FLOODING TO BE A SIGNIFICANT
POSSIBILITY IN THE TYPICAL POOR DRAINAGE AREAS OF ESC IF A PERIOD OF
HEAVIER DOWNPOURS DEVELOP WITH RAINFALL RATES CLOSE TO AN 0.5-1.0
INCH PER HOUR. N CNTRL UPPER MI WILL STILL LIKELY SEE SOME UPSLOPE
LAKE ENHANCEMENT TODAY-TONIGHT. THE FLOOD WATCH REMAINS POSTED FOR
MUCH OF W AND CENTRAL UPPER MI FOR TODAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FLOOD WATCH THROUGH THIS EVENING FOR MIZ001>006-009>013-084.
LAKE SUPERIOR...
GALE WARNING FROM 8 PM THIS EVENING TO 8 AM EDT THURSDAY FOR
LSZ251-267.
GALE WARNING FROM 2 PM THIS AFTERNOON TO 5 AM EDT THURSDAY FOR
LSZ246>250-265-266.
GALE WARNING UNTIL 4 AM EDT THURSDAY FOR LSZ243>245-264.
GALE WARNING UNTIL 2 AM EDT /1 AM CDT/ THURSDAY FOR LSZ240>242-
263.
GALE WARNING UNTIL 11 PM EDT /10 PM CDT/ THIS EVENING FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KF
LONG TERM...KC
AVIATION...VOSS
MARINE...KC
HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
426 AM EDT WED SEP 10 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 344 PM EDT TUE SEP 9 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A SPLIT FLOW PATTERN WITH A
DEVELOPING MID/UPPER LEVEL TROUGH OVER THE WRN CONUS. THE TAIL OF AN
ELONGATED SHORTWAVE TROUGH MOVING THROUGH NRN ONTARIO WAS DRAGGING A
COLD FRONT SLOWLY SOUTH INTO WRN LAKE SUPERIOR. A VIGOROUS SRN
STREAM SHRTWV MOVING IN THE CNTRL PLAINS WILL SUPPORT DEVELOPMENT OF
A SFC LOW THAT WILL MOVE INTO THE WRN LAKES WED. EVEN WITH LAKE
BREEZE ONSHORE WINDS INTO WRN UPPER MI...LOW LEVEL CONV HAS NOT BEEN
STRONG ENOUGH TO OVERCOME CAPPING WITH 800-750 MB TEMPS NEAR
12C...PER RUC. OTHERWISE...ABUNDANT CU PREVAILED ACROSS THE WEST
HALF OF UPPER MI WHILE MORE STABLE AIR OFF OF LAKE MI HAS KEPT SKIES
MOSTLY CLEAR OVER THE EAST.
THE POTENTIAL REMAINS FOR SOME SHRA/TSRA THIS EVENING AS THE FRONTAL
BOUNDARY MOVES THROUGH WRN UPPER MI. HOWEVER...COVERAGE SHOULD
LIMITED WITH ONLY LOWER END CHANCE POPS GIVEN THE STRENGTH OF THE
CAPPING.
AS THE PLAINS SHRTWV MOVES TOWARD THE AREA AND THE SFC LOW
DEEPENS...300-310 ISENTROPIC ASCENT ALONG WITH 800-600 MB FGEN WILL
STRENGTHEN AND SUPPORT AN EXPANDING AREA OF MODERATE TO HEAVY RAIN
FROM NW/N WI INTO WRN UPPER MI BY LATE EVENING AND INTO CNTRL UPPER
MI LATE TONIGHT. STRONG MID/UPPER LEVEL DYNAMICS WITH A COUPLED
UPPER LEVEL JET STRUCTURE AND STRONG QVECTOR CONV WILL SUPPORT A
LARGE AREA OF RAIN ACROSS THE CWA WED. SOME MODEL UNCERTAINTY
REMAINS AS THE NAM REMAINS MUCH DEEPER AND FARTHER TO THE NW THAN
MODELS CONSENSUS AND THE GFS FASTER AND ALONG THE SOUTHERN ENVELOPE
OF MODEL SPREAD. FAVORED THE MORE CONSISTENT ECMWF AND REGIONAL GEM
WITH THE LOW PATH TO NEAR GRB BY 18Z AND THE STRAITS BY 00Z/THU.
VERY STRONG 850 MB MOISTURE INFLOW...UPPER LEVEL AND 800-600 MB FGEN
EVEN WITHOUT TSRA WILL BRING THE POTENTIAL FOR A PERIOD OF HEAVY
RAIN...ESPECIALLY BTWN 09Z-18Z. UNCERTAINTY REMAINS ON THE IMPACT OF
UPSTREAM CONVECTION OVER IA INTO SRN WI ON THE EVOLUTION OF THE
850-700 MB FRONTAL BOUNDARY AND MOISTURE INFLOW TO THE NORTH.
HOWEVER...THE POTENTIAL REMAINS FOR QPF IN THE 1.5 INCH TO 2.0 INCH
RANGE...WITH LOCALLY HIGHER AMOUNTS AOA 3 INCHES. SO THE FLOOD WATCH
WILL REMAINS IN EFFECT.
NE WINDS VEERING TO THE NNE WILL ALSO INCREASE WITH GUSTS LIKELY IN
INTO THE 40-50 KNOT RANGE BY TO LATE AFTERNOON OVER THE
KEWEENAW...ESPECIALLY FOR LOCATIONS FAVORED BY NNE FLOW SUCH AS
COPPER HARBOR. AN ADVISORY WILL LIKELY BE NEEDED.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 359 AM EDT WED SEP 10 2014
MAIN FCST CONCERNS IN THE LONG TERM FOCUS ON HOW QUICKLY ON THU CLDS
AND SHOWERS ASSOCIATED WITH THE WED LO PRES WL EXIT THE CWA...TEMPS
AND THE POTENTIAL FOR FROST ON THU NGT AND THEN ON POPS ACCOMPANYING
THE PASSAGE OF ANOTHER DISTURBANCE THRU THE LOWER LKS ON FRI INTO
SAT. SINCE AN UPR TROF WL DOMINATE ERN NAMERICA THRU NEXT WEEK...
EXPECT BLO NORMAL TEMPS TO PREVAIL DURING THE EXTENDED PERIOD.
THU...AS DEPARTING LO PRES OVER FAR SW QUEBEC AT 12Z THU SHIFTS TO
THE ENE...STEADY N LLVL FLOW IS PROGGED TO WEAKEN AND BECOME MORE
ACYC UNDER GENERAL DEEP LYR QVECTOR DVGC LEFT IN THE WAKE OF THE
EXITING SHRTWV AND RDG AXIS EXPANDING TO THE E OF SFC HI CENTER IN
THE NRN PLAINS. EXPECT PLENTY OF CLDS IN THE MRNG WITH SHOWERS
MAINLY NEAR LK SUP ASSOCIATED WITH CHILLY LINGERING CYC FLOW OVER
THE RELATIVELY WARM LK SUP WATERS. BUT WITH INCRSG SUBSIDENCE/ACYC
FLOW IN THE PRESENCE OF DAYTIME HEATING...EXPECT THE SHOWERS TO
DIMINISH AND THE CLD PATTERN TO SHIFT TO MORE INLAND SC COVERAGE
UNDER THE H85 THERMAL TROF AND SUBSIDENCE INVRN SINKING TOWARD
H85-9. H85 TEMPS IN THE ZERO TO -2C RANGE WL SUPPORT WELL BLO NORMAL
HI TEMPS MAINLY IN THE UPR 40S/50S...COOLEST OVER THE HIER TERRAIN
OF THE NW HALF.
THU NGT...UNDER BLDG HI PRES WITH LOSS OF DAYTIME HEATING...EXPECT
LINGERING SC TO DSPT IN THE EVNG AND GIVE WAY TO AT LEAST A PERIOD
OF MOCLR SKIES AND LGT WINDS. WITH PWAT UNDER 0.5 INCH...TEMPS
SHOULD FALL OFF STEADILY. THE ONE LIMITING FACTOR WL BE HOW QUICKLY
HI CLDS IN ADVANCE OF SHRTWV MOVING THRU THE NRN PLAINS WL INVADE
THE UPR LKS. SUSPECT THE COLD SPOTS OVER THE INTERIOR WL SEE TEMPS
FALLING AOB 32...BUT WL HOLD OFF ON ANY KIND OF FREEZE WATCH/FROST
HEADLINE GIVEN ACTIVE SHORT TERM...MARGINALLY LO ENUF FCST TEMPS AND
COVERAGE OF THOSE REALLY LO TEMPS UNDER SOME INCRSG HI CLDS.
FRI THRU SAT...ALTHOUGH THERE IS GOOD MODEL AGREEMENT ON THE TIMING
AND TRACK OF A FAIRLY VIGOROUS SHRTWV THAT IS FCST TO MOVE E FM THE
NRN ROCKIES ON THU AFTN THRU THE NCENTRAL PLAINS AND ACROSS THE
LOWER LKS FRI NGT/SAT...THERE ARE SOME FAIRLY LARGE DIFFERENCES IN
THE MSLP FIELDS AND QPF. THE 09/12Z ECWMF CONTINUES TO BE THE MODEL
THAT SHOWS THE MORE IMPRESSIVE PRES FALL. WITH A DEEPER SFC
REFLECTION...THE ECMWF ALSO SHOWS MORE EXPANSIVE MID LVL MSTR/PCPN
EXTENDING INTO ALL OF UPR MI DURING FRI NGT/SAT MRNG. GIVEN THE
POSITIVE TILT TO THE SHRTWV....EXPANSIVE HI PRES THAT IS FCST TO
EXTEND FM THE NRN PLAINS INTO THE UPR LKS IN ADVANCE OF THIS SHRTWV
AND DRY/STABLE NATURE OF THE ANTECEDENT AIRMASS /PWAT AOB 0.5 INCH
WITH STRONG SUBSIDENCE INVRN BTWN H8-7/...SUSPECT THE NON-ECMWF
MODELS SHOWING LESS SFC RESPONSE ARE ON THE RIGHT TRACK. HAVE THUS
CHOSEN TO MAINTAIN ONLY LO CHC POPS...HIEST OVER THE SRN CWA CLOSER
TO THE SHRTWV TRACK/AREA OF SHARPER DEEP LYR QVECTOR CNVGC. THICKER
CLDS/THESE POPS WL ARRIVE ON FRI AFTN AS THE DISTURBANCE SLIDES
INTO THE UPR MS RIVER VALLEY. ONCE THE SHRTWV PUSHES TO THE E ON SAT
MRNG...TRAILING SHRTWV RDG/DRIER AIRMASS WL BRING A RETURN TO DRY
WX/CLRG. WITH H85 TEMPS IN THE ZERO TO -2C RANGE DURING THIS
TIME...THE WX WL BE UNSEASONABLY COOL. IF SKIES CLR FAST ENUF LATE
FRI NGT...NOT OUT OF THE QUESTION THERE COULD BE SOME FROST OVER THE
INTERIOR W ARND SUNRISE ON SAT.
EXTENDED...AFTER A DRY PERIOD ASSOCIATED WITH SFC HI PRES PASSING
THRU THE LOWER LKS ON SAT NGT...ANOTHER CNDN SHRTWV DIGGING THRU THE
MEAN UPR TROF CENTERED OVER HUDSON BAY AND INTO THE NCENTRAL CONUS
WL BRING A CHC OF MORE SHOWERS FOR SUN THRU MON. THIS DISTURBANCE WL
BE MSTR DEPRIVED...SO NO HEAVY RA IS LIKELY. HI PRES MOVING E UNDER
THE RISING HGTS IN THE WAKE OF THIS DISTURBANCE SHOULD BRING A
RETURN OF DRY WX FOR TUE. WITH THE MEAN TROF IN PLACE...TEMPS ACRS
UPR MI WL AVG BLO NORMAL DURING THIS TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1148 PM EDT TUE SEP 9 2014
NNE WIND SHIFT BEHIND A COLD FRONT MOVED BROUGHT LIFR CLOUDS INTO
IWD/CMX LAST EVENING. A FEW SHRA/TSRA HAVE ALSO POPPED UP ALONG
FRONTAL BOUNDARY MAINLY AT IWD. AS A STRONGER DISTURBANCE MOVES NEWD
AND THE MOIST LYR DEEPENS...WIDESPREAD RAIN WILL DEVELOP FROM SW TO
NE AND KEEPING CONDITIONS LIFR AT IWD/CMX INTO MUCH OF WED. SINCE
THE FROPA WL OCCUR LATER AT SAW...THE TRANSITION TO MVFR WILL NOT
OCCUR UNTIL AROUND 08Z. BY LATE TONIGHT INTO WED MORNING LIFR
CONDITIONS WILL PREVAIL AT SAW AS WELL WITH MODERATE TO OCNLY HEAVY
RAIN AND GUSTY NE-N WINDS DEVELOPING BY LATE MORNING/AFTERNOON. NE-N
WIND WILL GUST OVER 30 KT AT KCMX AND POSSIBLY AOA 25 KTS AT KSAW
AND IWD BY LATE MORNING/MIDDAY WED.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 AM EDT WED SEP 10 2014
AS A DEEP LO PRES MOVES NE THRU THE UPPER MIDWEST AND ACROSS
NORTHERN LOWER MI THIS EVENING ON ITS WAY INTO SE CANADA
TONIGHT...THE NE GALES AFFECTING WESTERN LAKE SUPERIOR WILL SPREAD E
OVER THE REST OF THE LAKE. EXPECT NNE GALES AS HI AS 40-45 KTS TODAY
INTO TONIGHT BEFORE THE LO PRES SHIFTS FAR ENOUGH TO THE E AND THE
GALES DIMINISH W TO E TONIGHT. AS HI PRES BUILDS TOWARD LAKE SUPERIOR
FROM THE PLAINS ON THU...LINGERING N WINDS UP TO 25-30 KTS IN THE
MORNING WILL DIMINISH W-E TO UNDER 15-20 KTS BY THE EVENING.
RELATIVELY LIGHT WINDS UNDER 20 KTS WILL THEN DOMINATE THRU THE
WEEKEND UNDER A RELATIVELY WEAK PRES GRADIENT. &&
.HYDROLOGY...
ISSUED AT 426 AM EDT WED SEP 10 2014
RAINFALL OVER THE W THIRD OF UPPER MI HAS BEEN CONVECTIVELY
ENHANCED...WITH RAINFALL RATES BRIEFLY RISING TO NEAR 6IN PER HOUR.
WITH THE QUICK MOVEMENT TO THE N JUST OVER 20KTS THAT AMOUNT WAS NOT
REALIZED. RADAR ESTIMATES THROUGH 08Z HAVE THE HIGHEST AMOUNTS OVER
NW GOGEBIC AND ALONG THE E ONTONAGON/W HOUGHTON COUNTIES...WITH 1.5
TO 2.25IN. SOME LOCAL RIVERS CONTINUE TO RESPOND TO THE RAINFALL A
FEW DAYS AGO...AND ARE RISING AT AN INCREASED RATE DO TO THE CURRENT
RAIN. SPECIFICALLY THIS INCLUDES THE SOUTH BRANCH OF THE ONTONAGON
RIVER AT EWEN /WHICH GIVEN THE TREND WILL SEE A SLOW RISE FOR THE
NEXT SEVERAL DAYS/. THE MIDDLE BRANCH OF THE ONTONAGON RIVER AT
PAULDING IS ALSO SLOWLY ON THE RISE.
OTHERWISE AN AVERAGED 0.5IN HAS FALLEN W OF A LINE FROM
IRON RIVER TO BARAGA. LITTLE RAIN HAS FALLEN E OF THIS LINE...WHICH
WILL CHANGE OVER THE NEXT COUPLE OF HRS AS ADDITIONAL SHOWERS NEAR
FROM WI. THUNDERSTORMS ARE MINIMAL OVER WI...AND PRECIP IS SLOWER
THAN ORIGINALLY ANTICIPATED. HAVE BACKED OFF ON THE STORM TOTAL
PRECIP OVER THE E THIRD OF THE FCST AREA AS A RESULT. EXPECT THE
TRADITIONAL URBAN/SMALL STREAM FLOODING TO BE A SIGNIFICANT
POSSIBILITY IN THE TYPICAL POOR DRAINAGE AREAS OF ESC IF A PERIOD OF
HEAVIER DOWNPOURS DEVELOP WITH RAINFALL RATES CLOSE TO AN 0.5-1.0
INCH PER HOUR. N CNTRL UPPER MI WILL STILL LIKELY SEE SOME UPSLOPE
LAKE ENHANCEMENT TODAY-TONIGHT. THE FLOOD WATCH REMAINS POSTED FOR
MUCH OF W AND CENTRAL UPPER MI FOR TODAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FLOOD WATCH THROUGH THIS EVENING FOR MIZ001>006-009>013-084.
LAKE SUPERIOR...
GALE WARNING FROM 8 PM THIS EVENING TO 8 AM EDT THURSDAY FOR
LSZ251-267.
GALE WARNING FROM 2 PM THIS AFTERNOON TO 5 AM EDT THURSDAY FOR
LSZ246>250-265-266.
GALE WARNING UNTIL 4 AM EDT THURSDAY FOR LSZ243>245-264.
GALE WARNING UNTIL 2 AM EDT /1 AM CDT/ THURSDAY FOR LSZ240>242-
263.
GALE WARNING UNTIL 11 PM EDT /10 PM CDT/ THIS EVENING FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...VOSS
MARINE...KC
HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
405 AM EDT WED SEP 10 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 344 PM EDT TUE SEP 9 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A SPLIT FLOW PATTERN WITH A
DEVELOPING MID/UPPER LEVEL TROUGH OVER THE WRN CONUS. THE TAIL OF AN
ELONGATED SHORTWAVE TROUGH MOVING THROUGH NRN ONTARIO WAS DRAGGING A
COLD FRONT SLOWLY SOUTH INTO WRN LAKE SUPERIOR. A VIGOROUS SRN
STREAM SHRTWV MOVING IN THE CNTRL PLAINS WILL SUPPORT DEVELOPMENT OF
A SFC LOW THAT WILL MOVE INTO THE WRN LAKES WED. EVEN WITH LAKE
BREEZE ONSHORE WINDS INTO WRN UPPER MI...LOW LEVEL CONV HAS NOT BEEN
STRONG ENOUGH TO OVERCOME CAPPING WITH 800-750 MB TEMPS NEAR
12C...PER RUC. OTHERWISE...ABUNDANT CU PREVAILED ACROSS THE WEST
HALF OF UPPER MI WHILE MORE STABLE AIR OFF OF LAKE MI HAS KEPT SKIES
MOSTLY CLEAR OVER THE EAST.
THE POTENTIAL REMAINS FOR SOME SHRA/TSRA THIS EVENING AS THE FRONTAL
BOUNDARY MOVES THROUGH WRN UPPER MI. HOWEVER...COVERAGE SHOULD
LIMITED WITH ONLY LOWER END CHANCE POPS GIVEN THE STRENGTH OF THE
CAPPING.
AS THE PLAINS SHRTWV MOVES TOWARD THE AREA AND THE SFC LOW
DEEPENS...300-310 ISENTROPIC ASCENT ALONG WITH 800-600 MB FGEN WILL
STRENGTHEN AND SUPPORT AN EXPANDING AREA OF MODERATE TO HEAVY RAIN
FROM NW/N WI INTO WRN UPPER MI BY LATE EVENING AND INTO CNTRL UPPER
MI LATE TONIGHT. STRONG MID/UPPER LEVEL DYNAMICS WITH A COUPLED
UPPER LEVEL JET STRUCTURE AND STRONG QVECTOR CONV WILL SUPPORT A
LARGE AREA OF RAIN ACROSS THE CWA WED. SOME MODEL UNCERTAINTY
REMAINS AS THE NAM REMAINS MUCH DEEPER AND FARTHER TO THE NW THAN
MODELS CONSENSUS AND THE GFS FASTER AND ALONG THE SOUTHERN ENVELOPE
OF MODEL SPREAD. FAVORED THE MORE CONSISTENT ECMWF AND REGIONAL GEM
WITH THE LOW PATH TO NEAR GRB BY 18Z AND THE STRAITS BY 00Z/THU.
VERY STRONG 850 MB MOISTURE INFLOW...UPPER LEVEL AND 800-600 MB FGEN
EVEN WITHOUT TSRA WILL BRING THE POTENTIAL FOR A PERIOD OF HEAVY
RAIN...ESPECIALLY BTWN 09Z-18Z. UNCERTAINTY REMAINS ON THE IMPACT OF
UPSTREAM CONVECTION OVER IA INTO SRN WI ON THE EVOLUTION OF THE
850-700 MB FRONTAL BOUNDARY AND MOISTURE INFLOW TO THE NORTH.
HOWEVER...THE POTENTIAL REMAINS FOR QPF IN THE 1.5 INCH TO 2.0 INCH
RANGE...WITH LOCALLY HIGHER AMOUNTS AOA 3 INCHES. SO THE FLOOD WATCH
WILL REMAINS IN EFFECT.
NE WINDS VEERING TO THE NNE WILL ALSO INCREASE WITH GUSTS LIKELY IN
INTO THE 40-50 KNOT RANGE BY TO LATE AFTERNOON OVER THE
KEWEENAW...ESPECIALLY FOR LOCATIONS FAVORED BY NNE FLOW SUCH AS
COPPER HARBOR. AN ADVISORY WILL LIKELY BE NEEDED.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 359 AM EDT WED SEP 10 2014
MAIN FCST CONCERNS IN THE LONG TERM FOCUS ON HOW QUICKLY ON THU CLDS
AND SHOWERS ASSOCIATED WITH THE WED LO PRES WL EXIT THE CWA...TEMPS
AND THE POTENTIAL FOR FROST ON THU NGT AND THEN ON POPS ACCOMPANYING
THE PASSAGE OF ANOTHER DISTURBANCE THRU THE LOWER LKS ON FRI INTO
SAT. SINCE AN UPR TROF WL DOMINATE ERN NAMERICA THRU NEXT WEEK...
EXPECT BLO NORMAL TEMPS TO PREVAIL DURING THE EXTENDED PERIOD.
THU...AS DEPARTING LO PRES OVER FAR SW QUEBEC AT 12Z THU SHIFTS TO
THE ENE...STEADY N LLVL FLOW IS PROGGED TO WEAKEN AND BECOME MORE
ACYC UNDER GENERAL DEEP LYR QVECTOR DVGC LEFT IN THE WAKE OF THE
EXITING SHRTWV AND RDG AXIS EXPANDING TO THE E OF SFC HI CENTER IN
THE NRN PLAINS. EXPECT PLENTY OF CLDS IN THE MRNG WITH SHOWERS
MAINLY NEAR LK SUP ASSOCIATED WITH CHILLY LINGERING CYC FLOW OVER
THE RELATIVELY WARM LK SUP WATERS. BUT WITH INCRSG SUBSIDENCE/ACYC
FLOW IN THE PRESENCE OF DAYTIME HEATING...EXPECT THE SHOWERS TO
DIMINISH AND THE CLD PATTERN TO SHIFT TO MORE INLAND SC COVERAGE
UNDER THE H85 THERMAL TROF AND SUBSIDENCE INVRN SINKING TOWARD
H85-9. H85 TEMPS IN THE ZERO TO -2C RANGE WL SUPPORT WELL BLO NORMAL
HI TEMPS MAINLY IN THE UPR 40S/50S...COOLEST OVER THE HIER TERRAIN
OF THE NW HALF.
THU NGT...UNDER BLDG HI PRES WITH LOSS OF DAYTIME HEATING...EXPECT
LINGERING SC TO DSPT IN THE EVNG AND GIVE WAY TO AT LEAST A PERIOD
OF MOCLR SKIES AND LGT WINDS. WITH PWAT UNDER 0.5 INCH...TEMPS
SHOULD FALL OFF STEADILY. THE ONE LIMITING FACTOR WL BE HOW QUICKLY
HI CLDS IN ADVANCE OF SHRTWV MOVING THRU THE NRN PLAINS WL INVADE
THE UPR LKS. SUSPECT THE COLD SPOTS OVER THE INTERIOR WL SEE TEMPS
FALLING AOB 32...BUT WL HOLD OFF ON ANY KIND OF FREEZE WATCH/FROST
HEADLINE GIVEN ACTIVE SHORT TERM...MARGINALLY LO ENUF FCST TEMPS AND
COVERAGE OF THOSE REALLY LO TEMPS UNDER SOME INCRSG HI CLDS.
FRI THRU SAT...ALTHOUGH THERE IS GOOD MODEL AGREEMENT ON THE TIMING
AND TRACK OF A FAIRLY VIGOROUS SHRTWV THAT IS FCST TO MOVE E FM THE
NRN ROCKIES ON THU AFTN THRU THE NCENTRAL PLAINS AND ACROSS THE
LOWER LKS FRI NGT/SAT...THERE ARE SOME FAIRLY LARGE DIFFERENCES IN
THE MSLP FIELDS AND QPF. THE 09/12Z ECWMF CONTINUES TO BE THE MODEL
THAT SHOWS THE MORE IMPRESSIVE PRES FALL. WITH A DEEPER SFC
REFLECTION...THE ECMWF ALSO SHOWS MORE EXPANSIVE MID LVL MSTR/PCPN
EXTENDING INTO ALL OF UPR MI DURING FRI NGT/SAT MRNG. GIVEN THE
POSITIVE TILT TO THE SHRTWV....EXPANSIVE HI PRES THAT IS FCST TO
EXTEND FM THE NRN PLAINS INTO THE UPR LKS IN ADVANCE OF THIS SHRTWV
AND DRY/STABLE NATURE OF THE ANTECEDENT AIRMASS /PWAT AOB 0.5 INCH
WITH STRONG SUBSIDENCE INVRN BTWN H8-7/...SUSPECT THE NON-ECMWF
MODELS SHOWING LESS SFC RESPONSE ARE ON THE RIGHT TRACK. HAVE THUS
CHOSEN TO MAINTAIN ONLY LO CHC POPS...HIEST OVER THE SRN CWA CLOSER
TO THE SHRTWV TRACK/AREA OF SHARPER DEEP LYR QVECTOR CNVGC. THICKER
CLDS/THESE POPS WL ARRIVE ON FRI AFTN AS THE DISTURBANCE SLIDES
INTO THE UPR MS RIVER VALLEY. ONCE THE SHRTWV PUSHES TO THE E ON SAT
MRNG...TRAILING SHRTWV RDG/DRIER AIRMASS WL BRING A RETURN TO DRY
WX/CLRG. WITH H85 TEMPS IN THE ZERO TO -2C RANGE DURING THIS
TIME...THE WX WL BE UNSEASONABLY COOL. IF SKIES CLR FAST ENUF LATE
FRI NGT...NOT OUT OF THE QUESTION THERE COULD BE SOME FROST OVER THE
INTERIOR W ARND SUNRISE ON SAT.
EXTENDED...AFTER A DRY PERIOD ASSOCIATED WITH SFC HI PRES PASSING
THRU THE LOWER LKS ON SAT NGT...ANOTHER CNDN SHRTWV DIGGING THRU THE
MEAN UPR TROF CENTERED OVER HUDSON BAY AND INTO THE NCENTRAL CONUS
WL BRING A CHC OF MORE SHOWERS FOR SUN THRU MON. THIS DISTURBANCE WL
BE MSTR DEPRIVED...SO NO HEAVY RA IS LIKELY. HI PRES MOVING E UNDER
THE RISING HGTS IN THE WAKE OF THIS DISTURBANCE SHOULD BRING A
RETURN OF DRY WX FOR TUE. WITH THE MEAN TROF IN PLACE...TEMPS ACRS
UPR MI WL AVG BLO NORMAL DURING THIS TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1148 PM EDT TUE SEP 9 2014
NNE WIND SHIFT BEHIND A COLD FRONT MOVED BROUGHT LIFR CLOUDS INTO
IWD/CMX LAST EVENING. A FEW SHRA/TSRA HAVE ALSO POPPED UP ALONG
FRONTAL BOUNDARY MAINLY AT IWD. AS A STRONGER DISTURBANCE MOVES NEWD
AND THE MOIST LYR DEEPENS...WIDESPREAD RAIN WILL DEVELOP FROM SW TO
NE AND KEEPING CONDITIONS LIFR AT IWD/CMX INTO MUCH OF WED. SINCE
THE FROPA WL OCCUR LATER AT SAW...THE TRANSITION TO MVFR WILL NOT
OCCUR UNTIL AROUND 08Z. BY LATE TONIGHT INTO WED MORNING LIFR
CONDITIONS WILL PREVAIL AT SAW AS WELL WITH MODERATE TO OCNLY HEAVY
RAIN AND GUSTY NE-N WINDS DEVELOPING BY LATE MORNING/AFTERNOON. NE-N
WIND WILL GUST OVER 30 KT AT KCMX AND POSSIBLY AOA 25 KTS AT KSAW
AND IWD BY LATE MORNING/MIDDAY WED.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 AM EDT WED SEP 10 2014AS A DEEP LO PRES MOVES NE THRU THE UPPER MIDWEST AND
ACROSS NORTHERN LOWER MI THIS EVENING ON ITS WAY INTO SE CANADA
TONIGHT...THE NE GALES AFFECTING WESTERN LAKE SUPERIOR WILL SPREAD E
OVER THE REST OF THE LAKE. EXPECT NNE GALES AS HI AS 40-45 KTS TODAY
INTO TONIGHT BEFORE THE LO PRES SHIFTS FAR ENOUGH TO THE E AND THE
GALES DIMINISH W TO E TONIGHT. AS HI PRES BUILDS TOWARD LAKE
SUPERIOR FROM THE PLAINS ON THU...LINGERING N WINDS UP TO 25-30 KTS
IN THE MORNING WILL DIMINISH W-E TO UNDER 15-20 KTS BY THE EVENING.
RELATIVELY LIGHT WINDS UNDER 20 KTS WILL THEN DOMINATE THRU THE
WEEKEND UNDER A RELATIVELY WEAK PRES GRADIENT.
&&
.HYDROLOGY...
ISSUED AT 344 PM EDT TUE SEP 9 2014
RAINFALL TOTALS FROM TONIGHT THROUGH WEDNESDAY NIGHT ACROSS UPPER MI
RANGE FROM JUST OVER 1.5 TO LOCALLY 3 INCHES. UNCERTAINTY REMAINS
WHERE THE HEAVIER BANDS OF RAIN WILL DEVELOP. HIGHER TOTALS INTO WED
NIGHT ARE EXPECTED FOR LOCATIONS IN N CNTRL UPPER MI WHERE STRONG
UPSLOPE FLOW WILL BOOST RAINFALL AMOUNTS. THE FLOOD WATCH REMAINS
POSTED FOR MUCH OF W AND CENTRAL UPPER MI.
EXPECT THE TRADITIONAL URBAN/SMALL STREAM FLOODING TO BE A
SIGNIFICANT POSSIBILITY IN THE TYPICAL POOR DRAINAGE AREAS OF ESC IF
A PERIOD OF HEAVIER DOWNPOURS DEVELOP WITH RAINFALL RATES CLOSE TO
AN 0.5-1.0 INCH PER HOUR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FLOOD WATCH THROUGH THIS EVENING FOR MIZ001>006-009>013-084.
LAKE SUPERIOR...
GALE WARNING FROM 8 PM THIS EVENING TO 8 AM EDT THURSDAY FOR
LSZ251-267.
GALE WARNING FROM 2 PM THIS AFTERNOON TO 5 AM EDT THURSDAY FOR
LSZ246>250-265-266.
GALE WARNING UNTIL 4 AM EDT THURSDAY FOR LSZ243>245-264.
GALE WARNING UNTIL 2 AM EDT /1 AM CDT/ THURSDAY FOR LSZ240>242-
263.
GALE WARNING UNTIL 11 PM EDT /10 PM CDT/ THIS EVENING FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...VOSS
MARINE...KC
HYDROLOGY...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
111 PM CDT WED SEP 10 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM CDT WED SEP 10 2014
MODERATE TO HEAVY RAIN CONTINUES OVER MUCH OF EAST CENTRAL MN AND
WEST CENTRAL WISCONSIN. ALTHOUGH THE GREATER MOISTURE TRANSPORT HAS
EXITED TO THE SOUTHEAST OF THE AREA...FAIRLY STRONG MID LEVEL
FRONTOGENESIS REMAINS OVER TWO SPECIFIC AREAS OF THE CWA. ONE OVER
EAST CENTRAL MN AND NORTHWEST WISCONSIN AND THE OTHER DEVELOPING TO
THE SOUTHEAST...MOVING NOW INTO WEST CENTRAL WISCONSIN. THE RUC AND
NAM SHOW THIS GRADUALLY WEAKENING AND LIFTING OFF TO THE EAST
DURING THE MORNING. THIS SHOULD TAKE THE RAIN WITH IT. THE THREAT
OF PONDING WATER REMAINS MAINLY ACROSS WEST CENTRAL WISCONSIN INTO
THE MORNING. COLLABORATION WITH SURROUNDING OFFICES DID YIELD THE
CONTINUATION OF THE FLOOD WATCH INTO WEST CENTRAL WISCONSIN.
TODAYS HIGH TEMPERATURES WILL LIKELY OCCUR THIS MORNING AS WELL.
THEY MAY CONTINUE TO DROP OFF THROUGH MID MORNING OR SO BEFORE
LEVELING OFF INTO THE AFTERNOON. STRONG NORTH WINDS RE EXPECTED TO
DEVELOP EAST AS LOW LEVEL CAA SPREADS OVER THE REGION.
CLOUDS ARE EXPECTED TO HANG TOUGH OVER MUCH OF THE AREA INTO THE
NIGHT. THERE IS SOME INDICATION THAT IN THE WAKE OF THE
TROUGH...SUBSIDENCE COULD BE STRONG ENOUGH TO ERODE THE LOWER CLOUD
COVER. WINDS WILL SLOWLY DIMINISH AS THE LOW CONTINUE TO LIFT
EAST/NORTHEAST INTO THE NIGHT. IT SHOULD COOL RAPIDLY IF BREAKS DO
DEVELOP INTO THE NORTH CENTRAL CWA DURING THE NIGHT. SOME UPPER 30S
POSSIBLE WHERE THIS OCCURS. READINGS IN THE LOWER 40S SHOULD REMAIN
ELSEWHERE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 327 AM CDT WED SEP 10 2014
THE LONG TERM FORECAST WILL FEATURE THE PASSAGE OF A SHORTWAVE
TROUGH AT THE BEGINNING OF THE PERIOD...FOLLOWED BY BRIEF SEMI-
ZONAL FLOW OVER THE WEEKEND...AND THEN A PATTERN TRANSITION TO
WESTERN RIDGING AND EASTERN TROUGHING THROUGH THE FIRST HALF OF
NEXT WEEK.
ON THURSDAY...A BROAD SURFACE HIGH BECOMES ESTABLISHED ACROSS THE
NATION/S MIDSECTION...WHILE A WEAK SHORTWAVE SLIDES EAST/SOUTHEAST
ACROSS THE AREA FROM THE NORTHERN/CANADIAN ROCKIES. WHILE THE
BETTER FORCING AND MORE PLENTIFUL MOISTURE WILL LIE SOUTH OF THE
FORECAST AREA...COULD SEE A FEW SHOWERS SNEAK INTO SOUTHERN MN AND
WEST CENTRAL WI LATE THURSDAY NIGHT AND FRIDAY. TEMPERATURES WILL
BE COOL...WITH HIGHS IN THE 50S ON THURSDAY AND FRIDAY...AND LOWS
DIPPING INTO THE MID TO UPPER 30S. DEPENDING ON HOW THE CLEARING
GOES AND WINDS...COULD POSSIBLY SEE SOME FROST ON SATURDAY
MORNING.
SATURDAY LOOKS TO HAVE THE HIGHEST POTENTIAL TO BE AN ENTIRELY DRY
DAY...AS SURFACE HIGH PRESSURE PREVAILS AND IN THE ABSENCE OF ANY
MID/UPPER DISTURBANCES.
SUNDAY BRINGS THE ARRIVAL OF WEAK SHORTWAVE ENERGY IN THE BASE OF
THE MANITOBA/ONTARIO TROUGH. MOISTURE AND FORCING ARE THE MOST
ROBUST NORTH AND EAST OF THE FORECAST AREA...BUT SUFFICIENT TO
WARRANT 20 POPS LOCALLY.
ON MONDAY...THINGS START TO DRY OUT WITH THE PATTERN EVOLUTION TO
WESTERN RIDGING. OVERALL...SHOULD BE DRY WITH SLIGHTLY BELOW
NORMAL TEMPERATURES THROUGH MID-WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 111 PM CDT WED SEP 10 2014
LOW MVFR CEILINGS WILL IMPROVE TO VFR FROM NW TO SE DURING THE
LATE AFTERNOON AND EVENING HOURS AS A LOW PRESSURE SYSTEM NEAR
KGRB CONTINUES TO MOVE NORTHEAST. MAIN CHANGE FROM THE PREVIOUS
SET WAS TO DELAY THE IMPROVEMENT TO VFR BY A FEW HOURS. THE ONE
AREA THAT MAY STILL END UP BEING TOO QUICK WITH THE IMPROVEMENT IS
KEAU WHERE THE LOW LEVEL CYCLONIC FLOW PERSISTS THROUGH THE NIGHT.
VFR DAY ON THURSDAY AND THERE MAY BE SOME SPRINKLES OR LIGHT RAIN
OVER WEST CENTRAL AND SOUTHWEST MN AS A WEATHER DISTURBANCE DROPS
SOUTHWARD THROUGH THE NORTHERN AND CENTRAL PLAINS. NORTH WINDS
THIS AFTERNOON FROM 15 TO 20 KNOTS WITH GUSTS TO 25 KNOTS...WILL
DIMINISH TO 10 KNOTS OR LESS TONIGHT. NORTH WINDS 10 TO 15 KNOTS
ON THURSDAY.
KMSP...MVFR CEILINGS FORECAST TO PERSIST INTO EARLY THIS EVENING
WHICH IS A FEW HOURS LATER THAN THE PREVIOUS TAF. VFR THEREAFTER
WITH CEILINGS AOA 050. NORTH WINDS GUSTING UP TO 30 KNOTS EARLY
THIS AFTERNOON THEN DIMINISHING QUICKLY THIS EVENING.
/OUTLOOK FOR KMSP/
FRI...VFR. WINDS NW AT 5-10 KNOTS.
SAT...VFR. WINDS SW 5-10 KNOTS.
SUN...VFR. WINDS SW 10 KNOTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...DWE
LONG TERM...LS
AVIATION...RAH
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
543 AM CDT WED SEP 10 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM CDT WED SEP 10 2014
MODERATE TO HEAVY RAIN CONTINUES OVER MUCH OF EAST CENTRAL MN AND
WEST CENTRAL WISCONSIN. ALTHOUGH THE GREATER MOISTURE TRANSPORT HAS
EXITED TO THE SOUTHEAST OF THE AREA...FAIRLY STRONG MID LEVEL
FRONTOGENESIS REMAINS OVER TWO SPECIFIC AREAS OF THE CWA. ONE OVER
EAST CENTRAL MN AND NORTHWEST WISCONSIN AND THE OTHER DEVELOPING TO
THE SOUTHEAST...MOVING NOW INTO WEST CENTRAL WISCONSIN. THE RUC AND
NAM SHOW THIS GRADUALLY WEAKENING AND LIFTING OFF TO THE EAST
DURING THE MORNING. THIS SHOULD TAKE THE RAIN WITH IT. THE THREAT
OF PONDING WATER REMAINS MAINLY ACROSS WEST CENTRAL WISCONSIN INTO
THE MORNING. COLLABORATION WITH SURROUNDING OFFICES DID YIELD THE
CONTINUATION OF THE FLOOD WATCH INTO WEST CENTRAL WISCONSIN.
TODAYS HIGH TEMPERATURES WILL LIKELY OCCUR THIS MORNING AS WELL.
THEY MAY CONTINUE TO DROP OFF THROUGH MID MORNING OR SO BEFORE
LEVELING OFF INTO THE AFTERNOON. STRONG NORTH WINDS RE EXPECTED TO
DEVELOP EAST AS LOW LEVEL CAA SPREADS OVER THE REGION.
CLOUDS ARE EXPECTED TO HANG TOUGH OVER MUCH OF THE AREA INTO THE
NIGHT. THERE IS SOME INDICATION THAT IN THE WAKE OF THE
TROUGH...SUBSIDENCE COULD BE STRONG ENOUGH TO ERODE THE LOWER CLOUD
COVER. WINDS WILL SLOWLY DIMINISH AS THE LOW CONTINUE TO LIFT
EAST/NORTHEAST INTO THE NIGHT. IT SHOULD COOL RAPIDLY IF BREAKS DO
DEVELOP INTO THE NORTH CENTRAL CWA DURING THE NIGHT. SOME UPPER 30S
POSSIBLE WHERE THIS OCCURS. READINGS IN THE LOWER 40S SHOULD REMAIN
ELSEWHERE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 327 AM CDT WED SEP 10 2014
THE LONG TERM FORECAST WILL FEATURE THE PASSAGE OF A SHORTWAVE
TROUGH AT THE BEGINNING OF THE PERIOD...FOLLOWED BY BRIEF SEMI-
ZONAL FLOW OVER THE WEEKEND...AND THEN A PATTERN TRANSITION TO
WESTERN RIDGING AND EASTERN TROUGHING THROUGH THE FIRST HALF OF
NEXT WEEK.
ON THURSDAY...A BROAD SURFACE HIGH BECOMES ESTABLISHED ACROSS THE
NATION/S MIDSECTION...WHILE A WEAK SHORTWAVE SLIDES EAST/SOUTHEAST
ACROSS THE AREA FROM THE NORTHERN/CANADIAN ROCKIES. WHILE THE
BETTER FORCING AND MORE PLENTIFUL MOISTURE WILL LIE SOUTH OF THE
FORECAST AREA...COULD SEE A FEW SHOWERS SNEAK INTO SOUTHERN MN AND
WEST CENTRAL WI LATE THURSDAY NIGHT AND FRIDAY. TEMPERATURES WILL
BE COOL...WITH HIGHS IN THE 50S ON THURSDAY AND FRIDAY...AND LOWS
DIPPING INTO THE MID TO UPPER 30S. DEPENDING ON HOW THE CLEARING
GOES AND WINDS...COULD POSSIBLY SEE SOME FROST ON SATURDAY
MORNING.
SATURDAY LOOKS TO HAVE THE HIGHEST POTENTIAL TO BE AN ENTIRELY DRY
DAY...AS SURFACE HIGH PRESSURE PREVAILS AND IN THE ABSENCE OF ANY
MID/UPPER DISTURBANCES.
SUNDAY BRINGS THE ARRIVAL OF WEAK SHORTWAVE ENERGY IN THE BASE OF
THE MANITOBA/ONTARIO TROUGH. MOISTURE AND FORCING ARE THE MOST
ROBUST NORTH AND EAST OF THE FORECAST AREA...BUT SUFFICIENT TO
WARRANT 20 POPS LOCALLY.
ON MONDAY...THINGS START TO DRY OUT WITH THE PATTERN EVOLUTION TO
WESTERN RIDGING. OVERALL...SHOULD BE DRY WITH SLIGHTLY BELOW
NORMAL TEMPERATURES THROUGH MID-WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 534 AM CDT WED SEP 10 2014
IFR/LIFR CONDITIONS ACROSS MOST TAF SITES THIS MORNING GRADUALLY
IMPROVING TO MVFR CIGS BY LATE AFTERNOON/EVENING. INTENSITY OF
RAIN SHIELD DIMINISHING AS SURFACE LOW/FORCING MOVES EAST. WILL
END RAIN FROM WEST TO EAST DURING THE MORNING IN MN AND LATEST IN
WESTERN WI SITES. NORTH WINDS TO REMAIN STRONG MOST AREAS DURING
THE DAY...DIMINISHING THIS EVENING. WILL TREND TO VFR INTO THE
EVENING WITH THE EXCEPTION OF THE WISCONSIN SITES.
KMSP...IFR IMPROVING TO MVFR THIS AFTERNOON/22Z. WILL KEEP CIGS BELOW
1700 FT FOR NOW. LIGHT RAIN TO END BY LATE MORNING. WILL TREND
CIGS TO VFR THIS EVENING WITH DIMINISHING WINDS.
/OUTLOOK FOR KMSP/
WED NITE...MVFR EARLY THEN VFR. WINDS N AT 5 TO 10KTS.
THU...VFR. WINDS NW AT 10G15KTS.
FRI...VFR. WINDS NW AT 10G15KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...FLASH FLOOD WATCH UNTIL 10 AM CDT THIS MORNING FOR WIZ015-016-
023>028.
&&
$$
SHORT TERM...DWE
LONG TERM...LS
AVIATION...DWE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
326 AM CDT WED SEP 10 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM CDT WED SEP 10 2014
MODERATE TO HEAVY RAIN CONTINUES OVER MUCH OF EAST CENTRAL MN AND
WEST CENTRAL WISCONSIN. ALTHOUGH THE GREATER MOISTURE TRANSPORT HAS
EXITED TO THE SOUTHEAST OF THE AREA...FAIRLY STRONG MID LEVEL
FRONTOGENESIS REMAINS OVER TWO SPECIFIC AREAS OF THE CWA. ONE OVER
EAST CENTRAL MN AND NORTHWEST WISCONSIN AND THE OTHER DEVELOPING TO
THE SOUTHEAST...MOVING NOW INTO WEST CENTRAL WISCONSIN. THE RUC AND
NAM SHOW THIS GRADUALLY WEAKENING AND LIFTING OFF TO THE EAST
DURING THE MORNING. THIS SHOULD TAKE THE RAIN WITH IT. THE THREAT
OF PONDING WATER REMAINS MAINLY ACROSS WEST CENTRAL WISCONSIN INTO
THE MORNING. COLLABORATION WITH SURROUNDING OFFICES DID YIELD THE
CONTINUATION OF THE FLOOD WATCH INTO WEST CENTRAL WISCONSIN.
TODAYS HIGH TEMPERATURES WILL LIKELY OCCUR THIS MORNING AS WELL.
THEY MAY CONTINUE TO DROP OFF THROUGH MID MORNING OR SO BEFORE
LEVELING OFF INTO THE AFTERNOON. STRONG NORTH WINDS RE EXPECTED TO
DEVELOP EAST AS LOW LEVEL CAA SPREADS OVER THE REGION.
CLOUDS ARE EXPECTED TO HANG TOUGH OVER MUCH OF THE AREA INTO THE
NIGHT. THERE IS SOME INDICATION THAT IN THE WAKE OF THE
TROUGH...SUBSIDENCE COULD BE STRONG ENOUGH TO ERODE THE LOWER CLOUD
COVER. WINDS WILL SLOWLY DIMINISH AS THE LOW CONTINUE TO LIFT
EAST/NORTHEAST INTO THE NIGHT. IT SHOULD COOL RAPIDLY IF BREAKS DO
DEVELOP INTO THE NORTH CENTRAL CWA DURING THE NIGHT. SOME UPPER 30S
POSSIBLE WHERE THIS OCCURS. READINGS IN THE LOWER 40S SHOULD REMAIN
ELSEWHERE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 327 AM CDT WED SEP 10 2014
THE LONG TERM FORECAST WILL FEATURE THE PASSAGE OF A SHORTWAVE
TROUGH AT THE BEGINNING OF THE PERIOD...FOLLOWED BY BRIEF SEMI-
ZONAL FLOW OVER THE WEEKEND...AND THEN A PATTERN TRANSITION TO
WESTERN RIDGING AND EASTERN TROUGHING THROUGH THE FIRST HALF OF
NEXT WEEK.
ON THURSDAY...A BROAD SURFACE HIGH BECOMES ESTABLISHED ACROSS THE
NATION/S MIDSECTION...WHILE A WEAK SHORTWAVE SLIDES EAST/SOUTHEAST
ACROSS THE AREA FROM THE NORTHERN/CANADIAN ROCKIES. WHILE THE
BETTER FORCING AND MORE PLENTIFUL MOISTURE WILL LIE SOUTH OF THE
FORECAST AREA...COULD SEE A FEW SHOWERS SNEAK INTO SOUTHERN MN AND
WEST CENTRAL WI LATE THURSDAY NIGHT AND FRIDAY. TEMPERATURES WILL
BE COOL...WITH HIGHS IN THE 50S ON THURSDAY AND FRIDAY...AND LOWS
DIPPING INTO THE MID TO UPPER 30S. DEPENDING ON HOW THE CLEARING
GOES AND WINDS...COULD POSSIBLY SEE SOME FROST ON SATURDAY
MORNING.
SATURDAY LOOKS TO HAVE THE HIGHEST POTENTIAL TO BE AN ENTIRELY DRY
DAY...AS SURFACE HIGH PRESSURE PREVAILS AND IN THE ABSENCE OF ANY
MID/UPPER DISTURBANCES.
SUNDAY BRINGS THE ARRIVAL OF WEAK SHORTWAVE ENERGY IN THE BASE OF
THE MANITOBA/ONTARIO TROUGH. MOISTURE AND FORCING ARE THE MOST
ROBUST NORTH AND EAST OF THE FORECAST AREA...BUT SUFFICIENT TO
WARRANT 20 POPS LOCALLY.
ON MONDAY...THINGS START TO DRY OUT WITH THE PATTERN EVOLUTION TO
WESTERN RIDGING. OVERALL...SHOULD BE DRY WITH SLIGHTLY BELOW
NORMAL TEMPERATURES THROUGH MID-WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1037 PM CDT TUE SEP 9 2014
CONDITIONS TO CONTINUE DETERIORATING THRU THE OVERNIGHT HOURS AS
A STORM SYSTEM MOVING NE FROM THE CENTRAL PLAINS INTO THE GREAT
LAKES WILL SPREAD RAIN ACROSS THE ENTIRE REGION BY THE EARLY
MORNING HOURS. CONDITIONS WILL LIKELY HIT IFR AT ALL
TERMINALS...WITH LIFR CERTAINLY POSSIBLE...FOR BOTH CEILINGS AND
VSBY. CONDITIONS WILL REMAIN DEGRADED THRU THE OVERNIGHT HOURS
WITH RAINFALL GRADUALLY ENDING FROM W TO E BY LATE MORNING.
CEILINGS WILL SLOWLY LIFT DURG THE DAY WED AND MAY REACH VFR
LEVELS BY WED EVE. WINDS WILL REMAIN BREEZY/GUSTY OVERNIGHT AS
THEY SWING FROM E-SE TO NE-N...THEN SETTLING ON N FOR MUCH OF THE
DAY WED BEFORE SPEEDS DIMINISH WED EVE. HAVE KEPT TSTM MENTION AT
A MINIMAL...IF AT ALL...DUE TO LOW CONFIDENCE IN PINPOINTING
LOCATION/TIMING.
KMSP...MVFR CONDS TO START THE 10/06Z TAFS WITH CONDS CONTINUING
TO DEGRADE THRU THE EARLY MRNG HOURS. CIGS LIKELY TO HIT IFR
LEVELS SHORTLY AFTER MIDNIGHT AND ARE EXPECTED TO REMAIN BELOW
1000 FT THRU LATE WED MRNG. RAIN WILL BE HEAVIEST OVERNIGHT BUT
LOOKS TO BECOME LIGHT BY THE MORNING PUSH...EVENTUALLY ENDING BY
MIDDAY. THAT SAID...CEILINGS LOOK TO REMAIN BELOW 1700 FT FOR MUCH
IF NOT THE ENTIRE DAY WED.
/OUTLOOK FOR KMSP/
WED...MVFR THEN VFR LATE. WINDS NNW AT 20G25KTS.
THU...VFR. WINDS NW AT 10G15KTS.
FRI...VFR. WINDS NW AT 10G15KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...FLASH FLOOD WATCH UNTIL 10 AM CDT THIS MORNING FOR WIZ015-016-
023>028.
&&
$$
SHORT TERM...DWE
LONG TERM...LS
AVIATION...JPC
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1019 PM CDT Thu Sep 11 2014
.UPDATE:
Issued at 950 PM CDT Thu Sep 11 2014
Grids have been updated to add patchy drizzle late tonight and
tomorrow morning.
Kanofsky
&&
.SHORT TERM: (Through Late Tonight)
Issued at 252 PM CDT Thu Sep 11 2014
Clouds have not cleared out this afternoon even though high
pressure has begun to build into the low levels. This is because
of persistent low level inversion that the RAP is showing around
900mb. Moisture is being trapped below this inversion, so expect
these clouds to persist into the night. Drizzle may redevelop over
the area toward morning. Temperatures did not climb much today and
do not have far to fall tonight to reach agreeable MOS guidance
for lows.
Britt
.LONG TERM: (Friday through Next Thursday)
Issued at 252 PM CDT Thu Sep 11 2014
Next shortwave to continue sliding southeast into forecast area on
Friday. Models in good agreement on timing and precipitation
associated with it. Will see isolated/widely scattered showers
develop and spread southeast across forecast area during the day
on Friday exiting late Friday evening. QPF amounts will be rather
light with best chances along and north of I-70. As for
temperatures, to remain well below normal with highs only in the
upper 50s to upper 60s. Lows Friday night will be in the low 40s
to low 50s.
Then on Saturday, strong ridge of high pressure to build in and
skies to clear out. Despite the sunshine, it will continue to feel
like fall with high temperatures only in the 60s and lows Saturday
night in the 40s.
By Sunday, surface ridge begins to move off to the east allowing
temperatures to slowly moderate. Highs will be in the upper 60s to
low 70s. Then Sunday night the next weather system to approach the
region with showers developing and spread southeast through region
Sunday night through Monday night. Frontal boundary to stall out
just south of forecast area early Tuesday morning with weak surface
ridging building in. Could see some lingering isolated/scattered
showers through Wednesday night for western and southern portions of
the area. As for temperatures, highs will be in the 70s and lows in
the 50s through next Thursday.
Byrd
&&
.AVIATION: (For the 00z TAFs through 00z Friday Evening)
Issued at 621 PM CDT Thu Sep 11 2014
Stratus continues to blanket the region producing widespread MVFR
flight conditions. I think the trend overnight will be for cig
heights to slowly lower to the far lower end of MVFR. During the
period from around 09z-15z or so we could see some drizzle
impacting the terminals and cig heights periodically dip into the
IFR flight category. Cig heights should improve on Friday but
remain MVFR as stratus remains locked across the region. There is
also a chance of some light rain across parts of northern MO into
western IL, potentially impacting KUIN in the afternoon but
confidence is too low to mention that far out in the forecast.
Specifics for KSTL:
Stratus continues to blanket the region producing widespread MVFR
flight conditions. I think the trend overnight will be for cig
heights to slowly lower to the far lower end of MVFR. During the
period from around 09z-15z or so we could see some drizzle and
cig heights periodically dip into the IFR flight category. Cig
heights should improve on Friday but remain MVFR as stratus
remains locked across the region.
Glass
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
627 PM CDT Thu Sep 11 2014
.SHORT TERM: (Through Late Tonight)
Issued at 252 PM CDT Thu Sep 11 2014
Clouds have not cleared out this afternoon even though high
pressure has begun to build into the low levels. This is because
of persistent low level inversion that the RAP is showing around
900mb. Moisture is being trapped below this inversion, so expect
these clouds to persist into the night. Drizzle may redevelop over
the area toward morning. Temperatures did not climb much today and
do not have far to fall tonight to reach agreeable MOS guidance
for lows.
Britt
.LONG TERM: (Friday through Next Thursday)
Issued at 252 PM CDT Thu Sep 11 2014
Next shortwave to continue sliding southeast into forecast area on
Friday. Models in good agreement on timing and precipitation
associated with it. Will see isolated/widely scattered showers
develop and spread southeast across forecast area during the day
on Friday exiting late Friday evening. QPF amounts will be rather
light with best chances along and north of I-70. As for
temperatures, to remain well below normal with highs only in the
upper 50s to upper 60s. Lows Friday night will be in the low 40s
to low 50s.
Then on Saturday, strong ridge of high pressure to build in and
skies to clear out. Despite the sunshine, it will continue to feel
like fall with high temperatures only in the 60s and lows Saturday
night in the 40s.
By Sunday, surface ridge begins to move off to the east allowing
temperatures to slowly moderate. Highs will be in the upper 60s to
low 70s. Then Sunday night the next weather system to approach the
region with showers developing and spread southeast through region
Sunday night through Monday night. Frontal boundary to stall out
just south of forecast area early Tuesday morning with weak surface
ridging building in. Could see some lingering isolated/scattered
showers through Wednesday night for western and southern portions of
the area. As for temperatures, highs will be in the 70s and lows in
the 50s through next Thursday.
Byrd
&&
.AVIATION: (For the 00z TAFs through 00z Friday Evening)
Issued at 621 PM CDT Thu Sep 11 2014
Stratus continues to blanket the region producing widespread MVFR
flight conditions. I think the trend overnight will be for cig
heights to slowly lower to the far lower end of MVFR. During the
period from around 09z-15z or so we could see some drizzle
impacting the terminals and cig heights periodically dip into the
IFR flight category. Cig heights should improve on Friday but
remain MVFR as stratus remains locked across the region. There is
also a chance of some light rain across parts of northern MO into
western IL, potentially impacting KUIN in the afternoon but
confidence is too low to mention that far out in the forecast.
Specifics for KSTL:
Stratus continues to blanket the region producing widespread MVFR
flight conditions. I think the trend overnight will be for cig
heights to slowly lower to the far lower end of MVFR. During the
period from around 09z-15z or so we could see some drizzle and
cig heights periodically dip into the IFR flight category. Cig
heights should improve on Friday but remain MVFR as stratus
remains locked across the region.
Glass
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
930 AM MDT WED SEP 10 2014
.UPDATE...
OVERALL FORECAST IN GOOD SHAPE...BUT HAVE ADDED SOME DETAIL FOR
THE AFTERNOON. MESOSCALE MODELS IN GOOD AGREEMENT THAT WESTERN
AND CENTRAL ZONES WILL SEE A BREAK IN PRECIPITATION THIS AFTERNOON
BEFORE NEXT STRONG WAVE DROPS SOUTH INTO OUR REGION LATE TODAY AND
TONIGHT. BROKE UP AFTERNOON TO REFLECT THIS BY LOWERING POPS TO
JUST CHANCE VARIETY BEFORE TRENDING TO MUCH HIGHER POPS BY
EVENING. ALREADY SOME SNOW AT JUDITH GAP...SO ATMOSPHERE A LITTLE
AHEAD OF MODELS FOR SUPPORTING SNOW.
MAIN FORECAST ISSUES FOR THE AFTERNOON PACKAGE INVOLVE WHETHER TO
ADD HIGHLIGHTS FOR PARK COUNTY/PARADISE VALLEY...BIG HORN
COUNTY/SOUTHERN ROSEBUD...AND HOW TO HANDLE SHERIDAN COUNTY WHERE
CONCERN IS OVER HOW SOON/IF THEY CHANGE OVER TO SNOW RIGHT IN
SHERIDAN. BT
&&
.SHORT TERM...VALID FOR TDY AND THU...
MAIN FORECAST ISSUE REVOLVES AROUND POTENTIAL SNOW EVENT TONIGHT
INTO THURSDAY.
DYNAMIC UPPER LOW DROPPING ALONG THE SPINE OF THE CANADIAN
ROCKIES...WITH AN IMPRESSIVE 120KT H3 NWLY JET ANALYZED IN CENTRAL
BRITISH COLUMBIA. CLOUD TOPS IN STRONGLY DIFFLUENT REGION OF THIS
LOW HAVE BEEN COOLING RAPIDLY TONIGHT WITH TOPS TO -45C AT 08Z.
LATEST OBS TO OUR NORTH SHOW SNOW ALONG THE EASTERN SLOPES OF THE
CANADIAN ROCKIES FROM CALGARY TO EDSON. LATEST MODELS AND EVEN THE
07Z RAP SHOW THE JET NOSING TOWARD SOUTH CENTRAL MT BY THIS
EVENING...LEAVING US IN A FAVORABLE POSITION FOR UPPER DIVERGENCE.
ALL MODELS HAVE BEEN CONSISTENTLY SHOWING STRONG Q-VECTOR
CONVERGENCE OVER OUR CWA TONIGHT THRU MUCH OF THURSDAY. ASCENT
WILL NOT BE AN ISSUE WITH THIS SYSTEM...BUT AREA OF FRONTOGENESIS
AND UPSLOPE FLOW WILL DICTATE WHERE THE HEAVIEST PCPN WILL BE.
CONFIDENCE CONTINUES TO INCREASE FOR AN UPSLOPE EVENT
MATERIALIZING BY THIS EVENING AND LASTING THROUGH MUCH OF
THURSDAY. LATEST OBSERVATIONS TO OUR NORTH HELP TO GIVE CREDENCE
TO THIS SCENARIO. IT ALSO SHOULD BE NOTED THAT MID LEVEL LAPSE
RATES ON THE ORDER OF 6-7 C/KM OVER OUR WEST SUGGEST A CONVECTIVE
COMPONENT OF THE PCPN TONIGHT THROUGH THURSDAY.
PCPN CHANCES WILL BE INCREASING TODAY WITH ISENTROPIC ASCENT AND
DIFFLUENCE ALOFT AND LATEST REGIONAL RADAR SHOWS SHOWERS SPREADING
IN FROM THE NORTH. AREAS OF FOG/DRIZZLE ALSO EXIST PER THE LOW
LEVEL SATURATED LAYER WITH UPSLOPE WINDS. TEMPS ACROSS OUR CWA
WILL SUPPORT A CHILLY RAIN WITH THE EXCEPTION OF THE HIGH COUNTRY.
BY 00Z...SECONDARY PUSH OF COLD ADVECTION WILL KICK IN SO EXPECT
SNOW LEVELS TO FALL SIGNIFICANTLY BY THIS EVENING.
HAVE ISSUED A WINTER WX ADVISORY FOR OUR NW PARTS...SPECIFICALLY
FROM THE EAST SIDE OF THE CRAZY MTNS THROUGH JUDITH GAP...PER A
PERIOD OF DEEP EAST FLOW AS THE UPPER TROF MOVES IN AND AN
EXPECTED TRANSITION TO SNOW BY THIS EVENING. WOULD EXPECT THE
BEARTOOTH AND RED LODGE FOOTHILLS TO SEE UPSLOPE SNOWFALL
BEGINNING SOMETIME THIS EVENING ALSO. HAVE ISSUED A WINTER STORM
WARNING FOR THE FOOTHILLS AND ALSO THE NORTH/EAST SLOPES OF THE
BEARTOOTH...ABSAROKA AND CRAZY MTNS. FOR ALL OF THESE
HIGHLIGHTS THE SNOW AMTS WILL VARY PER ELEVATION BUT THE BIGGEST
IMPACT WILL BE THE POTENTIAL FOR DOWNED TREES AND POWER LINES.
ANYONE PLANNING TRIPS TO THE HIGH COUNTRY WILL ALSO BE IMPACTED
INCLUDING BEARTOOTH PASS. MODELS CONTINUE TO SUGGEST BETWEEN A
HALF INCH AND INCH OF PCPN DURING TIME OF PEAK ASCENT...SO SEVERAL
INCHES OF SNOWFALL COULD OCCUR IN THESE UPSLOPE AREAS. TURNING TO
THE BIG HORNS AND SHERIDAN COUNTY...THOUGH THE MTNS WILL SEE A
HEAVY SNOWFALL...TRANSITION TO SNOW WILL BE A BIT LATER FOR THE
CITY OF SHERIDAN...PERHAPS LATE EVENING OR INTO THE OVERNIGHT
HOURS. POTENTIAL STILL EXISTS FOR AN INCH OF WATER AND HEAVY
SNOWFALL ON THE EASTERN ASPECTS OF THE BIG HORNS. GIVEN SOME
UNCERTAINTY IN SFC TEMPS IN SHERIDAN WILL LET THE WATCH CONTINUE
AND HAVE THE DAY SHIFT MAKE THE FINAL CALL ON SPECIFIC
HIGHLIGHTS. OTHER LOCATIONS WHICH MAY BE IMPACTED INCLUDE THE
HIGHER HILLS ACROSS OUR SOUTHEAST FROM SOUTHERN BIG HORN TO POWDER
RIVER COUNTIES...SUCH PLACES AS THE WOLF MTNS AND LAME DEER
DIVIDE. WOULD EXPECT SOME SLUSHY ACCUMULATION IN THESE AREAS TOO
ESPECIALLY IF FRONTOGENESIS LINGERS A BIT NORTH OF THE FOOTHILLS
AS SOME MODELS SUGGEST. SYSTEM WILL WIND DOWN THURSDAY AFTERNOON
AND EVENING.
TEMPS TODAY AND THURSDAY WILL MAX OUT ONLY IN THE 40S...WITH SOME
RECORD COLD HIGH TEMPS BEING CHALLENGED. COLDEST NIGHT WILL BE
THURSDAY NIGHT AS 1035MB SFC HIGH BUILDS IN AND ALLOWS FOR
CLEARING AND STRONG RADIATIONAL COOLING. SOME RECORD LOWS ARE
POSSIBLE THURSDAY NIGHT...AND SHERIDAN MAY SEE A LOW TEMP NEAR 20
DEGREES...A REMARKABLE NUMBER FOR SEPTEMBER 12TH.
JKL
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
ONCE THE STORM SYSTEM EXITS THE AREA LATE THURSDAY...NORTHWESTERLY
FLOW WILL REMAIN OVER THE AREA INTO THE WEEKEND. LATEST MODEL RUNS
CONTINUE TO TREND DRIER WITH THE FORECAST FOR THE WEEKEND AS
CLIPPER TYPE DISTURBANCES IN THE NORTHWEST STAY MAINLY NORTH OF
THE AREA. THIS LEAVES A DRIER DOWNSLOPE REGIME IN PLACE FOR
SOUTHERN MONTANA. TEMPERATURES WILL REMAIN BELOW AVERAGE THROUGH
THE WEEKEND. BY EARLY NEXT WEEK FLOW ALOFT TURNS WESTERLY ALLOWING
STRONGER DOWNSLOPE WARMING AND DRYING...WITH TEMPERATURES
RESPONDING INTO THE 70S AND MAYBE EVEN LOWER 80S BY NEXT
WEDNESDAY. WILL KEEP AN EYE ON CLIPPER SYSTEM PROGRESSION FOR ANY
SIGNS OF A SOUTHWARD SHIFT THAT COULD BRING A PERIOD OF SHOWERS
TO THE AREA THIS WEEKEND...BUT OVERALL LOOKS LIKE A VERY PLEASANT
WEEKEND AHEAD AT THIS TIME. CHAMBERS
&&
.AVIATION...
IFR OR LOWER CONDITIONS WILL BE WIDESPREAD THIS MORNING...WITH
OCCASIONAL MVFR CONDITIONS WHERE SHOWER ACTIVITY DISTURBS THE NEAR
SURFACE STRATUS AND FOG. WARMING MID DAY SHOULD ALLOW CEILINGS AND
VISIBILITY TO IMPROVE A BIT WITH MVFR CONDITIONS PREVAILING DURING
THE AFTERNOON...THOUGH POCKETS OF IFR WILL PERSIST. IFR OR LOWER
CONDITIONS WILL QUICKLY RE-DEVELOP EARLY THIS EVENING AS
PRECIPITATION INCREASES WITH ARRIVAL OF MAIN STORM SYSTEM.
MOUNTAIN TOPS WILL SEE PERIODIC CLEARING ESPECIALLY THIS AFTERNOON
BUT PASSES WILL BE OBSCURED TODAY. CHAMBERS
&&
.PRELIMINARY POINT TEMP/POPS...
TDY THU FRI SAT SUN MON TUE
-------------------------------------------------------
BIL 045 032/044 029/060 038/061 042/065 045/072 048/077
9/R 98/O 10/U 01/U 11/U 10/U 11/U
LVM 047 030/044 024/060 032/062 034/069 040/074 044/081
6/R 97/O 10/U 01/U 11/U 10/U 01/U
HDN 047 034/046 028/061 037/064 041/068 044/073 046/077
9/R 98/O 20/U 01/U 11/U 11/U 11/U
MLS 047 034/049 031/061 038/063 041/066 044/070 047/077
9/R 64/O 20/U 01/U 11/U 11/U 01/U
4BQ 047 033/045 028/058 037/063 040/065 044/071 047/076
8/R 78/O 21/U 01/U 11/U 10/U 11/U
BHK 046 033/047 029/055 035/064 038/065 041/070 044/074
7/R 44/O 21/U 01/U 11/U 11/U 01/U
SHR 049 032/040 022/057 032/063 036/067 041/073 044/079
6/R ++/O 31/U 01/U 11/U 11/U 11/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT FROM 6 PM THIS EVENING TO
NOON MDT THURSDAY FOR ZONES 28-41-63.
WINTER STORM WARNING IN EFFECT FROM 6 PM THIS EVENING TO 3 PM
MDT THURSDAY FOR ZONES 56-66-67.
WINTER STORM WARNING IN EFFECT UNTIL 3 PM MDT THURSDAY FOR
ZONE 68.
WY...WINTER STORM WATCH IN EFFECT FROM 6 PM MDT THIS EVENING
THROUGH THURSDAY MORNING FOR ZONES 98-99.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
255 AM MDT WED SEP 10 2014
.SHORT TERM...VALID FOR TDY AND THU...
MAIN FORECAST ISSUE REVOLVES AROUND POTENTIAL EARLY SEASON SNOW
EVENT TONIGHT AND THURSDAY.
DYNAMIC UPPER LOW DROPPING ALONG THE SPINE OF THE CANADIAN
ROCKIES...WITH AN IMPRESSIVE 120KT H3 NWLY JET ANALYZED IN CENTRAL
BRITISH COLUMBIA. CLOUD TOPS IN STRONGLY DIFFLUENT REGION OF THIS
LOW HAVE BEEN COOLING RAPIDLY TONIGHT WITH TOPS TO -45C AT 08Z.
LATEST OBS TO OUR NORTH SHOW SNOW ALONG THE EASTERN SLOPES OF THE
CANADIAN ROCKIES FROM CALGARY TO EDSON. LATEST MODELS AND EVEN THE
07Z RAP SHOW THE JET NOSING TOWARD SOUTH CENTRAL MT BY THIS
EVENING...LEAVING US IN A FAVORABLE POSITION FOR UPPER DIVERGENCE.
ALL MODELS HAVE BEEN CONSISTENTLY SHOWING STRONG Q-VECTOR
CONVERGENCE OVER OUR CWA TONIGHT THRU MUCH OF THURSDAY. ASCENT
WILL NOT BE AN ISSUE WITH THIS SYSTEM...BUT AREA OF FRONTOGENESIS
AND UPSLOPE FLOW WILL DICTATE WHERE THE HEAVIEST PCPN WILL BE.
CONFIDENCE CONTINUES TO INCREASE FOR AN UPSLOPE EVENT
MATERIALIZING BY THIS EVENING AND LASTING THROUGH MUCH OF
THURSDAY. LATEST OBSERVATIONS TO OUR NORTH HELP TO GIVE CREDENCE
TO THIS SCENARIO. IT ALSO SHOULD BE NOTED THAT MID LEVEL LAPSE
RATES ON THE ORDER OF 6-7 C/KM OVER OUR WEST SUGGEST A CONVECTIVE
COMPONENT OF THE PCPN TONIGHT THROUGH THURSDAY.
PCPN CHANCES WILL BE INCREASING TODAY WITH ISENTROPIC ASCENT AND
DIFFLUENCE ALOFT AND LATEST REGIONAL RADAR SHOWS SHOWERS SPREADING
IN FROM THE NORTH. AREAS OF FOG/DRIZZLE ALSO EXIST PER THE LOW
LEVEL SATURATED LAYER WITH UPSLOPE WINDS. TEMPS ACROSS OUR CWA
WILL SUPPORT A CHILLY RAIN WITH THE EXCEPTION OF THE HIGH COUNTRY.
BY 00Z...SECONDARY PUSH OF COLD ADVECTION WILL KICK IN SO EXPECT
SNOW LEVELS TO FALL SIGNIFICANTLY BY THIS EVENING.
HAVE ISSUED A WINTER WX ADVISORY FOR OUR NW PARTS...SPECIFICALLY
FROM THE EAST SIDE OF THE CRAZY MTNS THROUGH JUDITH GAP...PER A
PERIOD OF DEEP EAST FLOW AS THE UPPER TROF MOVES IN AND AN
EXPECTED TRANSITION TO SNOW BY THIS EVENING. WOULD EXPECT THE
BEARTOOTH AND RED LODGE FOOTHILLS TO SEE UPSLOPE SNOWFALL
BEGINNING SOMETIME THIS EVENING ALSO. HAVE ISSUED A WINTER STORM
WARNING FOR THE FOOTHILLS AND ALSO THE NORTH/EAST SLOPES OF THE
BEARTOOTH...ABSAROKA AND CRAZY MTNS. FOR ALL OF THESE
HIGHLIGHTS THE SNOW AMTS WILL VARY PER ELEVATION BUT THE BIGGEST
IMPACT WILL BE THE POTENTIAL FOR DOWNED TREES AND POWER LINES.
ANYONE PLANNING TRIPS TO THE HIGH COUNTRY WILL ALSO BE IMPACTED
INCLUDING BEARTOOTH PASS. MODELS CONTINUE TO SUGGEST BETWEEN A
HALF INCH AND INCH OF PCPN DURING TIME OF PEAK ASCENT...SO SEVERAL
INCHES OF SNOWFALL COULD OCCUR IN THESE UPSLOPE AREAS. TURNING TO
THE BIG HORNS AND SHERIDAN COUNTY...THOUGH THE MTNS WILL SEE A
HEAVY SNOWFALL...TRANSITION TO SNOW WILL BE A BIT LATER FOR THE
CITY OF SHERIDAN...PERHAPS LATE EVENING OR INTO THE OVERNIGHT
HOURS. POTENTIAL STILL EXISTS FOR AN INCH OF WATER AND HEAVY
SNOWFALL ON THE EASTERN ASPECTS OF THE BIG HORNS. GIVEN SOME
UNCERTAINTY IN SFC TEMPS IN SHERIDAN WILL LET THE WATCH CONTINUE
AND HAVE THE DAY SHIFT MAKE THE FINAL CALL ON SPECIFIC
HIGHLIGHTS. OTHER LOCATIONS WHICH MAY BE IMPACTED INCLUDE THE
HIGHER HILLS ACROSS OUR SOUTHEAST FROM SOUTHERN BIG HORN TO POWDER
RIVER COUNTIES...SUCH PLACES AS THE WOLF MTNS AND LAME DEER
DIVIDE. WOULD EXPECT SOME SLUSHY ACCUMULATION IN THESE AREAS TOO
ESPECIALLY IF FRONTOGENESIS LINGERS A BIT NORTH OF THE FOOTHILLS
AS SOME MODELS SUGGEST. SYSTEM WILL WIND DOWN THURSDAY AFTERNOON
AND EVENING.
TEMPS TODAY AND WEDNESDAY WILL MAX OUT ONLY IN THE 40S...WITH SOME
RECORD COLD HIGH TEMPS BEING CHALLENGED. COLDEST NIGHT WILL BE
THURSDAY NIGHT AS 1035MB SFC HIGH BUILDS IN AND ALLOWS FOR
CLEARING AND STRONG RADIATIONAL COOLING. SOME RECORD LOWS ARE
POSSIBLE THURSDAY NIGHT...AND SHERIDAN MAY SEE A LOW TEMP NEAR 20
DEGREES...A REMARKABLE NUMBER FOR SEPTEMBER 12TH.
JKL
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
ONCE THE STORM SYSTEM EXITS THE AREA LATE THURSDAY...NORTHWESTERLY
FLOW WILL REMAIN OVER THE AREA INTO THE WEEKEND. LATEST MODEL RUNS
CONTINUE TO TREND DRIER WITH THE FORECAST FOR THE WEEKEND AS
CLIPPER TYPE DISTURBANCES IN THE NORTHWEST STAY MAINLY NORTH OF
THE AREA. THIS LEAVES A DRIER DOWNSLOPE REGIME IN PLACE FOR
SOUTHERN MONTANA. TEMPERATURES WILL REMAIN BELOW AVERAGE THROUGH
THE WEEKEND. BY EARLY NEXT WEEK FLOW ALOFT TURNS WESTERLY ALLOWING
STRONGER DOWNSLOPE WARMING AND DRYING...WITH TEMPERATURES
RESPONDING INTO THE 70S AND MAYBE EVEN LOWER 80S BY NEXT
WEDNESDAY. WILL KEEP AN EYE ON CLIPPER SYSTEM PROGRESSION FOR ANY
SIGNS OF A SOUTHWARD SHIFT THAT COULD BRING A PERIOD OF SHOWERS
TO THE AREA THIS WEEKEND...BUT OVERALL LOOKS LIKE A VERY PLEASANT
WEEKEND AHEAD AT THIS TIME. CHAMBERS
&&
.AVIATION...
IFR OR LOWER CONDITIONS WILL BE WIDESPREAD THIS MORNING...WITH
OCCASIONAL MVFR CONDITIONS WHERE SHOWER ACTIVITY DISTURBS THE NEAR
SURFACE STRATUS AND FOG. WARMING MID DAY SHOULD ALLOW CEILINGS AND
VISIBILITY TO IMPROVE A BIT WITH MVFR CONDITIONS PREVAILING DURING
THE AFTERNOON...THOUGH POCKETS OF IFR WILL PERSIST. IFR OR LOWER
CONDITIONS WILL QUICKLY RE-DEVELOP EARLY THIS EVENING AS
PRECIPITATION INCREASES WITH ARRIVAL OF MAIN STORM SYSTEM.
MOUNTAIN TOPS WILL SEE PERIODIC CLEARING ESPECIALLY THIS AFTERNOON
BUT PASSES WILL BE OBSCURED TODAY. CHAMBERS
&&
.PRELIMINARY POINT TEMP/POPS...
TDY THU FRI SAT SUN MON TUE
-------------------------------------------------------
BIL 045 032/044 029/060 038/061 042/065 045/072 048/077
7/R 98/O 10/U 01/U 11/U 10/U 11/U
LVM 047 030/044 024/060 032/062 034/069 040/074 044/081
6/R 97/O 10/U 01/U 11/U 10/U 01/U
HDN 047 034/046 028/061 037/064 041/068 044/073 046/077
7/R 98/O 20/U 01/U 11/U 11/U 11/U
MLS 047 034/049 031/061 038/063 041/066 044/070 047/077
8/R 64/O 20/U 01/U 11/U 11/U 01/U
4BQ 047 033/045 028/058 037/063 040/065 044/071 047/076
8/R 78/O 21/U 01/U 11/U 10/U 11/U
BHK 046 033/047 029/055 035/064 038/065 041/070 044/074
6/R 44/O 21/U 01/U 11/U 11/U 01/U
SHR 049 032/040 022/057 032/063 036/067 041/073 044/079
6/R ++/O 31/U 01/U 11/U 11/U 11/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT FROM 6 PM THIS EVENING TO
NOON MDT THURSDAY FOR ZONES 28-41-63.
WINTER STORM WARNING IN EFFECT FROM 6 PM THIS EVENING TO 3 PM
MDT THURSDAY FOR ZONES 56-66-67.
WINTER STORM WARNING IN EFFECT FROM NOON TODAY TO 3 PM MDT
THURSDAY FOR ZONE 68.
WY...WINTER STORM WATCH IN EFFECT FROM THIS EVENING THROUGH
THURSDAY MORNING FOR ZONES 98-99.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
437 PM CDT WED SEP 10 2014
.UPDATE...
ISSUED AT 437 PM CDT WED SEP 10 2014
QUICK UPDATE TO EXPAND AN ISOLATED MENTION OF RAIN SHOWERS THROUGH
SOUTH CENTRAL NORTH DAKOTA THIS EVENING. LATEST BISMARCK AND
BOWMAN RADARS SHOWING AN AREA OF LIGHT RAIN SHOWERS MOVING EAST
OUT OF THE SOUTHWEST. A MID LEVEL CIRCULATION LOCATED IN THE WEST
WILL SLIDE EAST EARLY THIS EVENING...AND CONCUR WITH HIGHER
RESOLUTION MODELS OF THE RAP AND HRRR...THIS PRECIPITATION WEAKENS
BUT ALSO EXPANDS INTO SOUTH CENTRAL NORTH DAKOTA INCLUDING THE SOUTHERN
JAMES RIVER VALLEY BETWEEN 00Z AND 03Z.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 255 PM CDT WED SEP 10 2014
THE MAJOR FORECAST CHALLENGE WILL BE THE FROST POTENTIAL TONIGHT.
THE LATEST SHORT RANGE MODEL GUIDANCE CONTINUES TO PROG BOUNDARY
LAYER MOISTURE TO ERODE TO THE SOUTHWEST AS DRIER AIR GETS USHERED
IN FROM THE NORTHEAST. FURTHERMORE...BOUNDARY LAYER WINDS ARE
FORECAST TO WEAKEN TO AROUND 10 KNOTS TONIGHT AS HIGH PRESSURE
SETTLES INTO MONTANA. HOWEVER...THE LATEST GUIDANCE CONTINUES TO
PROG MID-LEVEL MOISTURE/CLOUDS (USING 850MB-500MB LAYER RH FIELDS)
TO STREAM OVER MOST OF WESTERN AND CENTRAL NORTH DAKOTA TONIGHT
AHEAD OF A SHORTWAVE ROTATING INTO MONTANA. THIS WOULD LIKELY
INHIBIT COOLING TEMPERATURES.
BALANCING WHERE THE CLEARING SKIES ARE FORECAST...WINDS WEAKENING
OVERNIGHT...AND BOUNDARY LAYER TEMPERATURES...THINK THE TURTLE
MOUNTAIN AREA WILL HAVE THE BEST CHANCE OF SEEING A FROST BETWEEN
09Z-14Z THURSDAY MORNING. AS A RESULT...ISSUED A FROST ADVISORY FOR
BOTTINEAU...ROLETTE...AND PIERCE COUNTIES FOR SAID TIME PERIOD.
TO THE SOUTHWEST...THERE WILL BE A CHANCE FOR A RAIN/SNOW MIX AFTER
MIDNIGHT. HOWEVER...ACCUMULATIONS SHOULD BE LIGHT.
FOR THURSDAY...DEEP MOISTURE AND ASSOCIATED PRECIP CHANCES WILL
CONTINUE TO PUSH SOUTH OF THE STATE AS HIGH PRESSURE BUILDS INTO THE
REGION. WELL BELOW NORMAL HIGHS ARE EXPECTED ONCE AGAIN WITH
READINGS RANGING FROM THE MID 40S SOUTHWEST TO THE MID 50S EAST.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 255 PM CDT WED SEP 10 2014
FOCUS IN THE LONG TERM WILL BE ON THE POTENTIAL FOR WIDESPREAD FROST
AND A FREEZE FRIDAY MORNING.
MODEL GUIDANCE CONTINUES TO SHOW LOWS IN THE UPPER 20S ACROSS THE
WEST AND LOWER 30S ELSEWHERE. WITH A LARGE SURFACE HIGH OVER THE
NORTHERN PLAINS WINDS WILL BE LIGHT. THE BIGGEST QUESTION WILL BE
HOW FAST CLOUDS CLEAR OUT. DEEP MOISTURE ACROSS THE STATE WILL BEGIN
TO CLEAR OUT QUICKLY AROUND 18 UTC THURSDAY...HOWEVER THE 12 UTC
MODEL GUIDANCE SHOWS A THIN LAYER OF LOW TO MID LEVEL MOISTURE
HANGING AROUND THROUGH 06 UTC FRIDAY.
REGARDLESS AT LEAST PATCHY FROST SEEMS LIKELY ACROSS CENTRAL AND
WESTERN NORTH DAKOTA. WIDESPREAD FROST IS LOOKING THE MOST LIKELY
ACROSS THE NORTHWEST AS CLOUD COVER WILL CLEAR FROM NORTH TO
SOUTH. THE NORTH WILL ALSO HAVE THE BEST OPPORTUNITY FOR A FREEZE AS
LOWS WILL MOSTLY BE BELOW FREEZING...ESPECIALLY NORTHWEST. AS FOR
THE SOUTH HAVE LIMITED THE WORDING FOR FROST AT AREAS FOR NOW AS
CLOUD COVER MAY STICK AROUND LONG ENOUGH TO PREVENT WIDESPREAD FROST
DEVELOPMENT. FOR THE SAME REASON THERE IS LESS OF A CHANCE OF A
FREEZE ACROSS THE SOUTH. TEMPERATURES WILL ALSO DROP LOW ENOUGH ON
SATURDAY MORNING ACROSS THE SOUTH...ESPECIALLY FOR THE
SOUTHWEST...FOR SOME PATCHY FROST.
FOR THE REMAINDER OF THE LONG TERM THE 12 UTC MODEL GUIDANCE
CONTINUES TO SHOW A MEAN TROUGH OVER THE U.S. THE 12 UTC GFS AND
ECMWF SHOW ANOTHER SHORT WAVE RIDING DOWN THE LEE OF THE CANADIAN
ROCKIES INTO THE NORTHERN PLAINS LATE SATURDAY INTO SUNDAY. MODELS
ARE NOT SHOWING MUCH PRECIPITATION WITH THIS SYSTEM AND THE
REMAINDER OF THE LONG TERM IS ALSO LOOKING MOSTLY DRY AND WARMER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1157 AM CDT WED SEP 10 2014
VFR CIGS WILL PREVAIL OVER KISN-KMOT-KBIS-KJMS THROUGH THE TAF
PERIOD. OTHERWISE...MVFR CONDITIONS ARE EXPECTED OVER KDIK THROUGH
THE LATE EVENING HOURS. MVFR CIGS SHOULD IMPROVE TO VFR OVER
SOUTHWESTERN NORTH DAKOTA TONIGHT. SEE INDIVIDUAL KDIK TAF FOR
DETAILS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY FROM 4 AM TO 9 AM CDT THURSDAY FOR NDZ004-005-013.
&&
$$
UPDATE...KS
SHORT TERM...TM
LONG TERM...MM
AVIATION...TM
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
128 PM EDT WED SEP 10 2014
.SYNOPSIS...
LOW PRESSURE OVER IOWA WILL MOVE ACROSS LAKE HURON PULLING A STRONG
COLD FRONT ACROSS THE AREA WEDNESDAY NIGHT. A WAVE OF LOW PRESSURE
WILL MOVE UP THE OHIO VALLEY FRIDAY NIGHT INTO SATURDAY THEN HIGH
PRESSURE OVER THE NORTHERN PLAINS WILL MOVE EAST THROUGH THE REGION
SUNDAY AND MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...MADE MORE ADJUSTMENTS TO POPS AND WX BASED ON CURRENT
RADAR TRENDS AND HRRR PROGS.
ORIGINAL...THE QUESTION TODAY IS HOW FAR OUT
AHEAD OF THE APPROACHING COLD FRONT WILL THE TSRA OCCUR. THE
LATEST MODEL RUNS HAVE QPF RAPIDLY SPREADING ESE ACROSS THE CWA
BETWEEN 18Z AND 00Z. WILL INCREASE POPS MORE FOR TODAY. THE THREAT
FOR SEVERE STORMS STILL LOOKS GOOD BASED ON INSTABILITY AND FAIRLY
GOOD WIND SHEAR. PW`S RISE BACK TO AROUND 2 INCHES SO LOCALLY
HEAVY RAIN CAN BE EXPECTED.
PATCHY MORNING FOG IN THE SOUTH WILL DISSIPATE THROUGH 10 AM.
TODAY WILL BE THE LAST RELATIVELY WARM DAY FOR A WHILE...POSSIBLY
THE REST OF THE SEASON BASED ON UPPER TROUGHING THAT IS GOING TO SET
UP OVER THE LAKES FOR AT LEAST THE NEXT 10 DAYS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
A FINAL BAND OF TSRA WITH THE STRONG COLD FRONT SHOULD PROGRESS
ACROSS THE CWA BETWEEN 06Z AND 12Z SO AFTER 12Z THU ONLY THE SE HALF
OF THE CWA SHOULD STILL HAVE A THREAT FOR RAIN WITH THE STRONGER
CONVECTION THEN EXITING THE CWA.
DRIER AIR MOVES IN BEHIND THE FRONT ALONG WITH THE LEADING PART OF A
MUCH COOLER AIRMASS. MARGINAL LAKE EFFECT CONDITIONS START TO
DEVELOP BY THE END OF THU NIGHT SO A FEW SHRA COULD BREAK OUT OVER
THE SNOWBELT AND NEARBY AREAS.
A SHARP S/W IS PROGGED TO MOVE EAST ACROSS THE LAKES FRI NIGHT INTO
SAT AND INDUCE A SURFACE WAVE THAT MOVES UP THE OH VALLEY. MOISTURE
POOLS BACK OVER THE AREA WITH WIDESPREAD SHRA DEVELOPING FRI NIGHT
AND CONTINUING INTO SAT BEFORE SHIFTING INTO MAINLY THE EAST SAT
AFTERNOON.
HIGH PRESSURE IS SHOWN TO BE QUICKLY SPREADING OVER THE AREA BY SAT
NIGHT BUT LAKE EFFECT CONDITIONS ARE POSSIBLE BASED ON TEMP
DIFFERENCES. DUE TO WIND ISSUES AND SUBSIDENCE FROM THE HIGH WILL
KEEP ONLY A SLIGHT CHANCE GOING SAT NIGHT IN THE NE.
TEMPS WILL TREND COOLER FOR FRI AND SAT WITH HIGHS BOTH DAYS MOSTLY
60 TO 65 DEGREES. SOME SPOTS ON SAT MAY NOT EVEN GET TO 60 DEGREES
IN THE INLAND EAST IF CLOUD COVER AND SHRA PERSIST. THE INCREASING
CLOUDS FRI NIGHT SHOULD HOLD UP LOWS IN A 45 TO 50 RANGE BUT BY SAT
NIGHT THE DECREASED CLOUDS AND LIGHT WINDS WILL ALLOW FOR LOWS IN
THE LOW TO MID 40S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
COOL HIGH PRESSURE WILL BE IN CONTROL OF THE REGION ON SUNDAY BUT IT
WILL BE SHIFTING OFF TO THE EAST AS ANOTHER UPPER LEVEL TROUGH DIGS
INTO THE GREAT LAKES REGION. AS THIS TROUGH MOVES OVERHEAD IT WILL
BRING AN INCREASING CHANCE OF SHOWERS. THE BETTER CHANCES OF THE
SHOWERS WILL BE MONDAY NIGHT INTO TUESDAY. THE SHOWERS MAY LINGER
DOWNWIND OF LAKE ERIE INTO TUESDAY EVENING. THE NEXT AREA OF HIGH
PRESSURE WILL THEN DRY THINGS OUT TUESDAY NIGHT INTO WEDNESDAY.
IT WILL BE COOL THROUGH THE LONG TERM WITH TEMPERATURES BELOW
SEASONAL AVERAGES. HIGHS AT MOST LOCATIONS WILL REMAIN IN THE 60S.
HOWEVER BY TUESDAY AND WEDNESDAY THE WESTERN COUNTY WARNING AREA
WILL BE NEAR TO SLIGHTLY ABOVE 70.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
SHOWERS WITH A FEW EMBEDDED TSRA MOVING THROUGH THIS EVENING
ASSOCIATED WITH WARM FRONT LIFTING ACROSS FORECAST AREA. QUESTION
REMAINS HOW STRONG THE TSRA WILL BE. SPC HAS MOST OF THE AERA IN
SLIGHT RISK FOR SEVERE FOR THIS EVENING. WITH A 50 KT JET AT 2K
FT MOVING INTO NW OH EXPECT TSRA TO INCREASE IN COVERAGE...HOWEVER
THAT SAID NOT SURE HOW WIDESPREAD TSRA WILL BECOME AS RAINSHOWERS
HAVE BEEN STABILIZING ATMOSPHERE. WILL LEAVE IN A FEW HOURS OF
TEMPO TSRA FOR NOW IN THE TAFS.
EXPECT IFR CIGS TO DEVELOP OVERNIGHT AS A COLD FRONT MOVES ACROSS
THE FORECAST AREA TONIGHT.
OUTLOOK...NON VFR POSSIBLE THURSDAY IN SHOWERS AND THUNDERSTORMS.
LOWER CEILINGS MAY LINGER OVER NE OHIO AND NW PA INTO FRIDAY AND
SATURDAY.
&&
.MARINE...
LOW PRESSURE WILL MOVE INTO THE CENTRAL GREAT LAKES TODAY WITH
INCREASING SOUTH TO SOUTHWEST WINDS EXPECTED INTO THIS EVENING.
WINDS WILL INCREASE THE EARLIEST ACROSS THE WESTERN BASIN WITH
SOUTHERLY WINDS IN THE 15 TO 25 KNOT RANGE. WINDS WILL BE OFFSHORE
SO WAVES SHOULD NOT BUILD ALL THAT MUCH. SINCE WINDS ARE EXPECTED TO
BE IN THE 15 TO 25 KNOT RANGE WE HOISTED THE SMALL CRAFT ADVISORY
FOR THIS AFTERNOON.
WINDS WILL EVENTUALLY SHIFT AROUND TO THE WEST AND NORTHWEST IN THE
WAKE OF THE COLD FRONT TONIGHT. THE FRONT SHOULD BE EAST OF THE LAKE
BY 12Z THURSDAY. THE REMAINDER OF THE LAKE WILL NEED TO HAVE A SMALL
CRAFT ADVISORY AT SOME POINT THIS EVENING INTO THE OVERNIGHT. LATER
SHIFTS WILL ISSUE IT WHEN IT IS NEEDED. THE COLD ADVECTION IN THE
WAKE OF THE FRONT WILL KEEP LARGER WAVES (4-6 FEET) GOING INTO AT
LEAST THURSDAY AFTERNOON/EVENING. AS HIGH PRESSURE RIDGES OVER THE
REGION WINDS WILL BECOME NORTHEAST BY FRIDAY MORNING. THIS WILL SET
UP A LONG FETCH INTO THE WESTERN HALF OF THE LAKE. IF THE PRESSURE
GRADIENT CAN REMAIN TIGHT ENOUGH WE MAY NEED SMALL CRAFT ADVISORIES
AGAIN FRIDAY INTO SATURDAY. MORE DETAILS TO COME ON THIS SCENARIO
THE NEXT COUPLE DAYS.
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE FRONT
AND TRACK ACROSS MUCH OF THE LAKE. A FEW OF THESE THUNDERSTORMS WILL
BECOME STRONG ENOUGH TO WARRANT THE ISSUANCE OF SPECIAL MARINE
WARNINGS FOR THIS EVENING AND POSSIBLY INTO THE OVERNIGHT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 AM EDT THURSDAY FOR LEZ142>145.
&&
$$
SYNOPSIS...ADAMS
NEAR TERM...ADAMS/TK
SHORT TERM...ADAMS
LONG TERM...MULLEN
AVIATION...DJB
MARINE...MULLEN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1137 AM EDT WED SEP 10 2014
.SYNOPSIS...
LOW PRESSURE OVER IOWA WILL MOVE ACROSS LAKE HURON PULLING A STRONG
COLD FRONT ACROSS THE AREA WEDNESDAY NIGHT. A WAVE OF LOW PRESSURE
WILL MOVE UP THE OHIO VALLEY FRIDAY NIGHT INTO SATURDAY THEN HIGH
PRESSURE OVER THE NORTHERN PLAINS WILL MOVE EAST THROUGH THE REGION
SUNDAY AND MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...MADE MORE ADJUSTMENTS TO POPS AND WX BASED ON CURRENT
RADAR TRENDS AND HRRR PROGS.
ORIGINAL...THE QUESTION TODAY IS HOW FAR OUT
AHEAD OF THE APPROACHING COLD FRONT WILL THE TSRA OCCUR. THE
LATEST MODEL RUNS HAVE QPF RAPIDLY SPREADING ESE ACROSS THE CWA
BETWEEN 18Z AND 00Z. WILL INCREASE POPS MORE FOR TODAY. THE THREAT
FOR SEVERE STORMS STILL LOOKS GOOD BASED ON INSTABILITY AND FAIRLY
GOOD WIND SHEAR. PW`S RISE BACK TO AROUND 2 INCHES SO LOCALLY
HEAVY RAIN CAN BE EXPECTED.
PATCHY MORNING FOG IN THE SOUTH WILL DISSIPATE THROUGH 10 AM.
TODAY WILL BE THE LAST RELATIVELY WARM DAY FOR A WHILE...POSSIBLY
THE REST OF THE SEASON BASED ON UPPER TROUGHING THAT IS GOING TO SET
UP OVER THE LAKES FOR AT LEAST THE NEXT 10 DAYS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
A FINAL BAND OF TSRA WITH THE STRONG COLD FRONT SHOULD PROGRESS
ACROSS THE CWA BETWEEN 06Z AND 12Z SO AFTER 12Z THU ONLY THE SE HALF
OF THE CWA SHOULD STILL HAVE A THREAT FOR RAIN WITH THE STRONGER
CONVECTION THEN EXITING THE CWA.
DRIER AIR MOVES IN BEHIND THE FRONT ALONG WITH THE LEADING PART OF A
MUCH COOLER AIRMASS. MARGINAL LAKE EFFECT CONDITIONS START TO
DEVELOP BY THE END OF THU NIGHT SO A FEW SHRA COULD BREAK OUT OVER
THE SNOWBELT AND NEARBY AREAS.
A SHARP S/W IS PROGGED TO MOVE EAST ACROSS THE LAKES FRI NIGHT INTO
SAT AND INDUCE A SURFACE WAVE THAT MOVES UP THE OH VALLEY. MOISTURE
POOLS BACK OVER THE AREA WITH WIDESPREAD SHRA DEVELOPING FRI NIGHT
AND CONTINUING INTO SAT BEFORE SHIFTING INTO MAINLY THE EAST SAT
AFTERNOON.
HIGH PRESSURE IS SHOWN TO BE QUICKLY SPREADING OVER THE AREA BY SAT
NIGHT BUT LAKE EFFECT CONDITIONS ARE POSSIBLE BASED ON TEMP
DIFFERENCES. DUE TO WIND ISSUES AND SUBSIDENCE FROM THE HIGH WILL
KEEP ONLY A SLIGHT CHANCE GOING SAT NIGHT IN THE NE.
TEMPS WILL TREND COOLER FOR FRI AND SAT WITH HIGHS BOTH DAYS MOSTLY
60 TO 65 DEGREES. SOME SPOTS ON SAT MAY NOT EVEN GET TO 60 DEGREES
IN THE INLAND EAST IF CLOUD COVER AND SHRA PERSIST. THE INCREASING
CLOUDS FRI NIGHT SHOULD HOLD UP LOWS IN A 45 TO 50 RANGE BUT BY SAT
NIGHT THE DECREASED CLOUDS AND LIGHT WINDS WILL ALLOW FOR LOWS IN
THE LOW TO MID 40S.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
COOL HIGH PRESSURE WILL BE IN CONTROL OF THE REGION ON SUNDAY BUT IT
WILL BE SHIFTING OFF TO THE EAST AS ANOTHER UPPER LEVEL TROUGH DIGS
INTO THE GREAT LAKES REGION. AS THIS TROUGH MOVES OVERHEAD IT WILL
BRING AN INCREASING CHANCE OF SHOWERS. THE BETTER CHANCES OF THE
SHOWERS WILL BE MONDAY NIGHT INTO TUESDAY. THE SHOWERS MAY LINGER
DOWNWIND OF LAKE ERIE INTO TUESDAY EVENING. THE NEXT AREA OF HIGH
PRESSURE WILL THEN DRY THINGS OUT TUESDAY NIGHT INTO WEDNESDAY.
IT WILL BE COOL THROUGH THE LONG TERM WITH TEMPERATURES BELOW
SEASONAL AVERAGES. HIGHS AT MOST LOCATIONS WILL REMAIN IN THE 60S.
HOWEVER BY TUESDAY AND WEDNESDAY THE WESTERN COUNTY WARNING AREA
WILL BE NEAR TO SLIGHTLY ABOVE 70.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
SOME PATCHY MVFR FOG ACROSS THE EASTERN HALF OF THE REGION WILL
BURN OFF QUICKLY.
GUSTY SOUTHERLY WINDS WILL DEVELOP BY MID TO LATE MORNING AS A
COLD FRONT MOVES TOWARD THE REGION. WIND GUSTS MAY REACH 30 TO 35
KNOTS NEAR THE LAKESHORE FROM CLEVELAND AND POINTS WEST FOR THE
AFTERNOON AND EVENING.
THE MAIN CONCERN WILL BE THE STRENGTH OF THE THUNDERSTORMS THAT
DEVELOP THIS AFTERNOON/EVENING. HAVE MOVED UP THE TIMING OF
THUNDERSTORMS TODAY WITH CURRENT RADAR TRENDS ALREADY SHOWING
SHOWERS AND THUNDERSTORMS INTO CENTRAL INDIANA. THE FASTER TIMING
COULD END UP BEING A GOOD THING SINCE THICKER CLOUD COVER WILL
DECREASE THE INSTABILITY. THESE SHOWERS AND THUNDERSTORMS WILL
THEN SLOWLY TRACK ACROSS THE REGION THROUGH THE OVERNIGHT.
OUTLOOK...NON VFR POSSIBLE WEDNESDAY NIGHT INTO THURSDAY IN
SHOWERS AND THUNDERSTORMS. LOWER CEILINGS MAY LINGER OVER NE OHIO
AND NW PA INTO FRIDAY AND SATURDAY.
&&
.MARINE...
LOW PRESSURE WILL MOVE INTO THE CENTRAL GREAT LAKES TODAY WITH
INCREASING SOUTH TO SOUTHWEST WINDS EXPECTED INTO THIS EVENING.
WINDS WILL INCREASE THE EARLIEST ACROSS THE WESTERN BASIN WITH
SOUTHERLY WINDS IN THE 15 TO 25 KNOT RANGE. WINDS WILL BE OFFSHORE
SO WAVES SHOULD NOT BUILD ALL THAT MUCH. SINCE WINDS ARE EXPECTED TO
BE IN THE 15 TO 25 KNOT RANGE WE HOISTED THE SMALL CRAFT ADVISORY
FOR THIS AFTERNOON.
WINDS WILL EVENTUALLY SHIFT AROUND TO THE WEST AND NORTHWEST IN THE
WAKE OF THE COLD FRONT TONIGHT. THE FRONT SHOULD BE EAST OF THE LAKE
BY 12Z THURSDAY. THE REMAINDER OF THE LAKE WILL NEED TO HAVE A SMALL
CRAFT ADVISORY AT SOME POINT THIS EVENING INTO THE OVERNIGHT. LATER
SHIFTS WILL ISSUE IT WHEN IT IS NEEDED. THE COLD ADVECTION IN THE
WAKE OF THE FRONT WILL KEEP LARGER WAVES (4-6 FEET) GOING INTO AT
LEAST THURSDAY AFTERNOON/EVENING. AS HIGH PRESSURE RIDGES OVER THE
REGION WINDS WILL BECOME NORTHEAST BY FRIDAY MORNING. THIS WILL SET
UP A LONG FETCH INTO THE WESTERN HALF OF THE LAKE. IF THE PRESSURE
GRADIENT CAN REMAIN TIGHT ENOUGH WE MAY NEED SMALL CRAFT ADVISORIES
AGAIN FRIDAY INTO SATURDAY. MORE DETAILS TO COME ON THIS SCENARIO
THE NEXT COUPLE DAYS.
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE FRONT
AND TRACK ACROSS MUCH OF THE LAKE. A FEW OF THESE THUNDERSTORMS WILL
BECOME STRONG ENOUGH TO WARRANT THE ISSUANCE OF SPECIAL MARINE
WARNINGS FOR THIS EVENING AND POSSIBLY INTO THE OVERNIGHT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 AM EDT THURSDAY FOR LEZ142>145.
&&
$$
SYNOPSIS...ADAMS
NEAR TERM...ADAMS/TK
SHORT TERM...ADAMS
LONG TERM...MULLEN
AVIATION...MULLEN
MARINE...MULLEN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
948 AM EDT WED SEP 10 2014
.SYNOPSIS...
LOW PRESSURE OVER IOWA WILL MOVE ACROSS LAKE HURON PULLING A STRONG
COLD FRONT ACROSS THE AREA WEDNESDAY NIGHT. A WAVE OF LOW PRESSURE
WILL MOVE UP THE OHIO VALLEY FRIDAY NIGHT INTO SATURDAY THEN HIGH
PRESSURE OVER THE NORTHERN PLAINS WILL MOVE EAST THROUGH THE REGION
SUNDAY AND MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...MADE SOME ADJUSTMENTS TO POPS AND WX BASED ON CURRENT
RADAR TRENDS AND HRRR PROGS.
ORIGINAL...THE QUESTION TODAY IS HOW FAR OUT
AHEAD OF THE APPROACHING COLD FRONT WILL THE TSRA OCCUR. THE
LATEST MODEL RUNS HAVE QPF RAPIDLY SPREADING ESE ACROSS THE CWA
BETWEEN 18Z AND 00Z. WILL INCREASE POPS MORE FOR TODAY. THE THREAT
FOR SEVERE STORMS STILL LOOKS GOOD BASED ON INSTABILITY AND FAIRLY
GOOD WIND SHEAR. PW`S RISE BACK TO AROUND 2 INCHES SO LOCALLY
HEAVY RAIN CAN BE EXPECTED.
PATCHY MORNING FOG IN THE SOUTH WILL DISSIPATE THROUGH 10 AM.
TODAY WILL BE THE LAST RELATIVELY WARM DAY FOR A WHILE...POSSIBLY
THE REST OF THE SEASON BASED ON UPPER TROUGHING THAT IS GOING TO SET
UP OVER THE LAKES FOR AT LEAST THE NEXT 10 DAYS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
A FINAL BAND OF TSRA WITH THE STRONG COLD FRONT SHOULD PROGRESS
ACROSS THE CWA BETWEEN 06Z AND 12Z SO AFTER 12Z THU ONLY THE SE HALF
OF THE CWA SHOULD STILL HAVE A THREAT FOR RAIN WITH THE STRONGER
CONVECTION THEN EXITING THE CWA.
DRIER AIR MOVES IN BEHIND THE FRONT ALONG WITH THE LEADING PART OF A
MUCH COOLER AIRMASS. MARGINAL LAKE EFFECT CONDITIONS START TO
DEVELOP BY THE END OF THU NIGHT SO A FEW SHRA COULD BREAK OUT OVER
THE SNOWBELT AND NEARBY AREAS.
A SHARP S/W IS PROGGED TO MOVE EAST ACROSS THE LAKES FRI NIGHT INTO
SAT AND INDUCE A SURFACE WAVE THAT MOVES UP THE OH VALLEY. MOISTURE
POOLS BACK OVER THE AREA WITH WIDESPREAD SHRA DEVELOPING FRI NIGHT
AND CONTINUING INTO SAT BEFORE SHIFTING INTO MAINLY THE EAST SAT
AFTERNOON.
HIGH PRESSURE IS SHOWN TO BE QUICKLY SPREADING OVER THE AREA BY SAT
NIGHT BUT LAKE EFFECT CONDITIONS ARE POSSIBLE BASED ON TEMP
DIFFERENCES. DUE TO WIND ISSUES AND SUBSIDENCE FROM THE HIGH WILL
KEEP ONLY A SLIGHT CHANCE GOING SAT NIGHT IN THE NE.
TEMPS WILL TREND COOLER FOR FRI AND SAT WITH HIGHS BOTH DAYS MOSTLY
60 TO 65 DEGREES. SOME SPOTS ON SAT MAY NOT EVEN GET TO 60 DEGREES
IN THE INLAND EAST IF CLOUD COVER AND SHRA PERSIST. THE INCREASING
CLOUDS FRI NIGHT SHOULD HOLD UP LOWS IN A 45 TO 50 RANGE BUT BY SAT
NIGHT THE DECREASED CLOUDS AND LIGHT WINDS WILL ALLOW FOR LOWS IN
THE LOW TO MID 40S.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
COOL HIGH PRESSURE WILL BE IN CONTROL OF THE REGION ON SUNDAY BUT IT
WILL BE SHIFTING OFF TO THE EAST AS ANOTHER UPPER LEVEL TROUGH DIGS
INTO THE GREAT LAKES REGION. AS THIS TROUGH MOVES OVERHEAD IT WILL
BRING AN INCREASING CHANCE OF SHOWERS. THE BETTER CHANCES OF THE
SHOWERS WILL BE MONDAY NIGHT INTO TUESDAY. THE SHOWERS MAY LINGER
DOWNWIND OF LAKE ERIE INTO TUESDAY EVENING. THE NEXT AREA OF HIGH
PRESSURE WILL THEN DRY THINGS OUT TUESDAY NIGHT INTO WEDNESDAY.
IT WILL BE COOL THROUGH THE LONG TERM WITH TEMPERATURES BELOW
SEASONAL AVERAGES. HIGHS AT MOST LOCATIONS WILL REMAIN IN THE 60S.
HOWEVER BY TUESDAY AND WEDNESDAY THE WESTERN COUNTY WARNING AREA
WILL BE NEAR TO SLIGHTLY ABOVE 70.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
SOME PATCHY MVFR FOG ACROSS THE EASTERN HALF OF THE REGION WILL
BURN OFF QUICKLY.
GUSTY SOUTHERLY WINDS WILL DEVELOP BY MID TO LATE MORNING AS A
COLD FRONT MOVES TOWARD THE REGION. WIND GUSTS MAY REACH 30 TO 35
KNOTS NEAR THE LAKESHORE FROM CLEVELAND AND POINTS WEST FOR THE
AFTERNOON AND EVENING.
THE MAIN CONCERN WILL BE THE STRENGTH OF THE THUNDERSTORMS THAT
DEVELOP THIS AFTERNOON/EVENING. HAVE MOVED UP THE TIMING OF
THUNDERSTORMS TODAY WITH CURRENT RADAR TRENDS ALREADY SHOWING
SHOWERS AND THUNDERSTORMS INTO CENTRAL INDIANA. THE FASTER TIMING
COULD END UP BEING A GOOD THING SINCE THICKER CLOUD COVER WILL
DECREASE THE INSTABILITY. THESE SHOWERS AND THUNDERSTORMS WILL
THEN SLOWLY TRACK ACROSS THE REGION THROUGH THE OVERNIGHT.
OUTLOOK...NON VFR POSSIBLE WEDNESDAY NIGHT INTO THURSDAY IN
SHOWERS AND THUNDERSTORMS. LOWER CEILINGS MAY LINGER OVER NE OHIO
AND NW PA INTO FRIDAY AND SATURDAY.
&&
.MARINE...
LOW PRESSURE WILL MOVE INTO THE CENTRAL GREAT LAKES TODAY WITH
INCREASING SOUTH TO SOUTHWEST WINDS EXPECTED INTO THIS EVENING.
WINDS WILL INCREASE THE EARLIEST ACROSS THE WESTERN BASIN WITH
SOUTHERLY WINDS IN THE 15 TO 25 KNOT RANGE. WINDS WILL BE OFFSHORE
SO WAVES SHOULD NOT BUILD ALL THAT MUCH. SINCE WINDS ARE EXPECTED TO
BE IN THE 15 TO 25 KNOT RANGE WE HOISTED THE SMALL CRAFT ADVISORY
FOR THIS AFTERNOON.
WINDS WILL EVENTUALLY SHIFT AROUND TO THE WEST AND NORTHWEST IN THE
WAKE OF THE COLD FRONT TONIGHT. THE FRONT SHOULD BE EAST OF THE LAKE
BY 12Z THURSDAY. THE REMAINDER OF THE LAKE WILL NEED TO HAVE A SMALL
CRAFT ADVISORY AT SOME POINT THIS EVENING INTO THE OVERNIGHT. LATER
SHIFTS WILL ISSUE IT WHEN IT IS NEEDED. THE COLD ADVECTION IN THE
WAKE OF THE FRONT WILL KEEP LARGER WAVES (4-6 FEET) GOING INTO AT
LEAST THURSDAY AFTERNOON/EVENING. AS HIGH PRESSURE RIDGES OVER THE
REGION WINDS WILL BECOME NORTHEAST BY FRIDAY MORNING. THIS WILL SET
UP A LONG FETCH INTO THE WESTERN HALF OF THE LAKE. IF THE PRESSURE
GRADIENT CAN REMAIN TIGHT ENOUGH WE MAY NEED SMALL CRAFT ADVISORIES
AGAIN FRIDAY INTO SATURDAY. MORE DETAILS TO COME ON THIS SCENARIO
THE NEXT COUPLE DAYS.
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE FRONT
AND TRACK ACROSS MUCH OF THE LAKE. A FEW OF THESE THUNDERSTORMS WILL
BECOME STRONG ENOUGH TO WARRANT THE ISSUANCE OF SPECIAL MARINE
WARNINGS FOR THIS EVENING AND POSSIBLY INTO THE OVERNIGHT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 AM EDT THURSDAY FOR LEZ142>145.
&&
$$
SYNOPSIS...ADAMS
NEAR TERM...ADAMS/TK
SHORT TERM...ADAMS
LONG TERM...MULLEN
AVIATION...MULLEN
MARINE...MULLEN
AREA FORECAST DISCUSSION
NWS TULSA OK
929 PM CDT THU SEP 11 2014
.DISCUSSION...
REGIONAL SFC ANALYSIS SHOWS FRONTAL BOUNDARY STALLED NEAR/SOUTH OF
I-20 IN TEXAS WITH A SECOND...STRONGER SURGE OF COLD AIR SLIDING
DOWN THE FRONT RANGE OF THE ROCKIES. THUS FAR NO PRECIP IN THE
AREA BUT LATER TONIGHT IN RESPONSE TO MID LEVEL WAVE DIVING
THROUGH CENTRAL ROCKIES...EXPECT LIFT TO INCREASE NORTH OF THE
STALLED BOUNDARY RESULTING IN INCREASING COVERAGE OF SHOWERS
MAINLY ALONG AND SOUTH OF I-40 TOWARD MORNING. BOTH HRRR AND LOCAL
WRF HAVE REMAINED CONSISTENT IN DEPICTING THIS SCENARIO WITH
ELEVATED INSTABILITY ALSO INCREASING. THUS WILL KEEP THE HIGHER
CHANCES OF SHOWERS LATE TONIGHT IN SOUTHERN AREAS...ONLY REAL
CHANCE TO FORECAST WAS TO TAKE OUT MOST PRECIP THROUGH 06Z. TEMPS
FALLING SLOWLY UNDER LOW CLOUD DECK WHICH WILL HOLD FIRM...HOWEVER
SECOND SURGE OF COLDER AIR LIKELY WILL DROP AREAS NEAR KS BORDER
INTO THE 50S BY MORNING. NO ADDITIONAL UPDATES AT THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 653 PM CDT THU SEP 11 2014/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
OVERCAST MVFR CEILINGS WILL REMAIN COMMON TONIGHT AND INTO FRIDAY
ACROSS MUCH OF THE REGION. THE EXCEPTIONS LOOK TO BE ACROSS
SOUTHEAST OKLAHOMA AND NORTHWEST ARKANSAS WHERE IFR CONDITIONS ARE
EXPECTED FRIDAY MORNING. SOME PERIODS OF IFR MAY ALSO BE POSSIBLE
OVER NORTHEAST OKLAHOMA WITHIN ANY AREAS OF DRIZZLE THAT DEVELOPS
FRIDAY MORNING. DRIZZLE COULD ALSO BE POSSIBLE OVER FAR NORTHWEST
ARKANSAS FRIDAY MORNING...WHILE GREATER CHANCES OF SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE FOR SOUTHEAST OKLAHOMA INTO WEST
CENTRAL ARKANSAS LATE TONIGHT INTO FRIDAY AFTERNOON.
PREV DISCUSSION... /ISSUED 350 PM CDT THU SEP 11 2014/
DISCUSSION...
COLD FRONT BOUNDARY FROM TEXAS EAST ACROSS GULF COAST
STATES WILL REMAIN WELL SOUTH OF OUR AREA THROUGH THE
WEEKEND. SIG UPPER WAVE AND ASSOCIATED COLD AIR WHICH
TURNED THE BLACK HILLS WHITE SINKING SOUTHEAST & WILL
BRING A REINFORCING SHOT OF COLD AIR TO THE SOUTHERN
PLAINS FRIDAY NIGHT. BACKING UPPER WINDS NEAR THE RED
RIVER WARRANTS CHANCE PRECIP OVERNIGHT TONIGHT SOUTH.
FRIDAY SOUTHERN MOISTURE MERGES WITH NORTHERN MOISTURE
ASSOCIATED WITH UPPER WAVE AND COLD INTRUSION. GENERAL
1.5 TO 2.0 PRECIPITABLE WATER YIELDS BETTER THAN EVEN
POPS SOUTH I-40. CHANCE PRECIP MAINLY SOUTHEAST FRIDAY
NIGHT. LOW TEMPERATURES AROUND DAWN SATURDAY KS / MO
BORDER AREAS WHERE SKIES CLEAR...45-50. SURFACE RIDGE
AXIS PAST EASTERN OKLAHOMA/NORTHWEST ARKANSAS SATURDAY
NIGHT. RETURN SOUTHERLY SURFACE FLOW BEGINNING SUNDAY
WILL PUSH TEMPERATURES BACK TO NORMAL LEVEL BY TUESDAY.
NORTHWEST FLOW EARLY NEXT WEEK RESULTS IN MARGINAL POPS.
GW
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 60 68 51 72 / 20 50 20 10
FSM 65 71 57 74 / 50 50 30 10
MLC 65 69 55 72 / 50 60 30 10
BVO 56 66 46 70 / 10 50 20 0
FYV 58 66 50 69 / 20 40 30 10
BYV 57 67 50 68 / 20 40 30 10
MKO 62 67 52 71 / 30 50 30 10
MIO 56 67 47 69 / 10 30 20 0
F10 61 68 52 71 / 30 50 30 10
HHW 68 73 60 75 / 70 70 40 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...14
LONG TERM....99
AREA FORECAST DISCUSSION
NWS NORMAN OK
559 PM CDT WED SEP 10 2014
.AVIATION...
0Z TAFS... VFR/MVFR CEILINGS EXPECTED FOR THIS TAF PERIOD.
SHOWERS/STORMS WILL BE POSSIBLE ACROSS THE SOUTHERN HALF OF THE
AREA THROUGHOUT THE PERIOD BUT MOST LIKELY SITES TO RECEIVE RAIN
WILL BE OVER THE NEXT FEW HOURS IN CENTRAL OK W/STRONGEST STORMS
REMAINING SOUTH AND EAST OF THE TAF SITES.
&&
.PREV DISCUSSION... /ISSUED 356 PM CDT WED SEP 10 2014/
DISCUSSION...
THE INITIAL COLD FRONT IS CURRENTLY MOVING THROUGH SOUTHERN
OKLAHOMA AND WESTERN NORTH TEXAS. HRRR SUGGESTS THUNDERSTORMS MAY
STILL DEVELOP AHEAD OF THE FRONT IN FAR SOUTHERN OKLAHOMA AND
WESTERN NORTH TEXAS LATE AFTERNOON INTO THE EVENING. THERE WILL
ALSO BE POST-FRONTAL PRECIPITATION...SO KEPT POPS BEHIND THE
FRONT TONIGHT.
MOST AREAS SHOULD BE DRY DURING THE DAY TOMORROW. ONLY
A CHANCE ACROSS SOUTHERN OK AND WESTERN NORTH TX. A
SECONDARY...STRONGER COLD FRONT IS EXPECTED TO MOVE THROUGH THE
AREA ON FRIDAY. AHEAD OF THE SECONDARY FRONT...ISENTROPIC ASCENT
WILL BE PRESENT NEAR THE 305K SFC THURSDAY NIGHT INTO FRIDAY
MORNING. THE GREATEST ISENTROPIC ASCENT AND ELEVATED INSTABILITY
APPEARS TO BE ACROSS SOUTHERN OKLAHOMA...ESPECIALLY EAST OF I-35.
EXPECT SHOWERS AND THUNDERSTORMS DURING THIS PERIOD IN SOUTHERN
OKLAHOMA. THE ASCENT AND ASSOCIATED PRECIPITATION SHOULD WEAKEN BY
MID-MORNING.
THE AIR MASS BEHIND THIS FRONT IS FAIRLY COLD AND IS ORIGINATING
FROM A 1040 MB SFC HIGH IN WESTERN CANADA. THE FRONT APPEARS TO BE
A TYPICAL SHALLOW COLD FRONT WHERE A THERMAL TROUGH/PRESSURE RIDGE
DEVELOPS ACROSS THE HIGH PLAINS. LEANED TOWARD THE NAM12 BECAUSE
IT SEEMS TO HAVE A MORE REALISTIC REPRESENTATION OF SURFACE
FEATURES ON FRIDAY. BEHIND THE COLD FRONT...WIDESPREAD LOW CLOUDS
AND LIGHT PRECIPITATION/DRIZZLE WILL RESULT IN STEADY OR FALLING
TEMPERATURES DURING THE DAY FRIDAY. AREAS NORTH AND WEST WILL STAY
IN THE 50S ALL DAY. EVEN CENTRAL OKLAHOMA MAY SEE TEMPERATURES
FALL INTO THE 50S IN THE AFTERNOON. ASCENT SEEMS TO BE VERY WEAK
BEHIND THE FRONT...SO EXPECT VERY LIGHT PRECIPITATION TOTALS.
MAYBE SLIGHTLY HIGHER TOTALS IN NORTHWEST OK.
LOW-LEVEL DRY AIR WILL FLOW IN FROM THE NORTH FRIDAY NIGHT. SKIES
MAY CLEAR OUT ACROSS THE NORTHERN CWA. EXPECT SATURDAY MORNING
WILL BE THE COLDEST MORNING IN THE NEXT WEEK. 40S WILL BE LIKELY
NORTH OF I-40. IT WOULD NOT BE SURPRISING TO SEE A COUPLE UPPER
30S NEAR THE KANSAS BORDER IF SKIES CAN COMPLETELY CLEAR. SOUTH OF
I-40...STRONGER WINDS AND CLOUD COVER MAY KEEP TEMPERATURES FROM
BOTTOMING OUT. LOW TO MID 50S WILL BE POSSIBLE THERE.
SATURDAY...MOSTLY SUNNY SKIES ARE EXPECTED ACROSS THE NORTHERN TWO
THIRDS OF THE CWA. LOW-LEVEL RH FIELDS SUGGEST MORE WIDESPREAD
CLOUDS MAY STICK AROUND ACROSS FAR SOUTHERN OKLAHOMA AND WESTERN
NORTH TEXAS. HIGH TEMPERATURES WILL BE 10 TO 15 DEGREES BELOW
AVERAGE SATURDAY AFTERNOON.
AS A LEE TROUGH DEVELOPS...RETURN SOUTHERLY FLOW WILL RESULT IN A
MODERATING TREND ON SUNDAY. HIGHS WILL BE SEASONABLE IN THE LOW TO
MID 80S. A COLD FRONT WILL APPROACH NORTHERN OKLAHOMA LATE MONDAY
INTO TUESDAY. THERE IS SOME UNCERTAINTY ON HOW FAR SOUTH THE FRONT
WILL GO. NEVERTHELESS...THE FRONT AND NORTHWEST FLOW ALOFT SUGGEST
AT LEAST LOW POPS ARE NEEDED LATE MONDAY THROUGH WEDNESDAY.
MAHALE
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 62 76 61 65 / 20 10 30 40
HOBART OK 60 76 59 67 / 20 10 30 50
WICHITA FALLS TX 65 80 64 72 / 40 30 50 50
GAGE OK 53 73 51 58 / 0 10 30 50
PONCA CITY OK 57 75 55 63 / 0 10 20 40
DURANT OK 68 80 68 72 / 60 40 60 50
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
30/25/25
AREA FORECAST DISCUSSION
NWS NORMAN OK
356 PM CDT WED SEP 10 2014
.DISCUSSION...
THE INITIAL COLD FRONT IS CURRENTLY MOVING THROUGH SOUTHERN
OKLAHOMA AND WESTERN NORTH TEXAS. HRRR SUGGESTS THUNDERSTORMS MAY
STILL DEVELOP AHEAD OF THE FRONT IN FAR SOUTHERN OKLAHOMA AND
WESTERN NORTH TEXAS LATE AFTERNOON INTO THE EVENING. THERE WILL
ALSO BE POST-FRONTAL PRECIPITATION...SO KEPT POPS BEHIND THE
FRONT TONIGHT.
MOST AREAS SHOULD BE DRY DURING THE DAY TOMORROW. ONLY
A CHANCE ACROSS SOUTHERN OK AND WESTERN NORTH TX. A
SECONDARY...STRONGER COLD FRONT IS EXPECTED TO MOVE THROUGH THE
AREA ON FRIDAY. AHEAD OF THE SECONDARY FRONT...ISENTROPIC ASCENT
WILL BE PRESENT NEAR THE 305K SFC THURSDAY NIGHT INTO FRIDAY
MORNING. THE GREATEST ISENTROPIC ASCENT AND ELEVATED INSTABILITY
APPEARS TO BE ACROSS SOUTHERN OKLAHOMA...ESPECIALLY EAST OF I-35.
EXPECT SHOWERS AND THUNDERSTORMS DURING THIS PERIOD IN SOUTHERN
OKLAHOMA. THE ASCENT AND ASSOCIATED PRECIPITATION SHOULD WEAKEN BY
MID-MORNING.
THE AIR MASS BEHIND THIS FRONT IS FAIRLY COLD AND IS ORIGINATING
FROM A 1040 MB SFC HIGH IN WESTERN CANADA. THE FRONT APPEARS TO BE
A TYPICAL SHALLOW COLD FRONT WHERE A THERMAL TROUGH/PRESSURE RIDGE
DEVELOPS ACROSS THE HIGH PLAINS. LEANED TOWARD THE NAM12 BECAUSE
IT SEEMS TO HAVE A MORE REALISTIC REPRESENTATION OF SURFACE
FEATURES ON FRIDAY. BEHIND THE COLD FRONT...WIDESPREAD LOW CLOUDS
AND LIGHT PRECIPITATION/DRIZZLE WILL RESULT IN STEADY OR FALLING
TEMPERATURES DURING THE DAY FRIDAY. AREAS NORTH AND WEST WILL STAY
IN THE 50S ALL DAY. EVEN CENTRAL OKLAHOMA MAY SEE TEMPERATURES
FALL INTO THE 50S IN THE AFTERNOON. ASCENT SEEMS TO BE VERY WEAK
BEHIND THE FRONT...SO EXPECT VERY LIGHT PRECIPITATION TOTALS.
MAYBE SLIGHTLY HIGHER TOTALS IN NORTHWEST OK.
LOW-LEVEL DRY AIR WILL FLOW IN FROM THE NORTH FRIDAY NIGHT. SKIES
MAY CLEAR OUT ACROSS THE NORTHERN CWA. EXPECT SATURDAY MORNING
WILL BE THE COLDEST MORNING IN THE NEXT WEEK. 40S WILL BE LIKELY
NORTH OF I-40. IT WOULD NOT BE SURPRISING TO SEE A COUPLE UPPER
30S NEAR THE KANSAS BORDER IF SKIES CAN COMPLETELY CLEAR. SOUTH OF
I-40...STRONGER WINDS AND CLOUD COVER MAY KEEP TEMPERATURES FROM
BOTTOMING OUT. LOW TO MID 50S WILL BE POSSIBLE THERE.
SATURDAY...MOSTLY SUNNY SKIES ARE EXPECTED ACROSS THE NORTHERN TWO
THIRDS OF THE CWA. LOW-LEVEL RH FIELDS SUGGEST MORE WIDESPREAD
CLOUDS MAY STICK AROUND ACROSS FAR SOUTHERN OKLAHOMA AND WESTERN
NORTH TEXAS. HIGH TEMPERATURES WILL BE 10 TO 15 DEGREES BELOW
AVERAGE SATURDAY AFTERNOON.
AS A LEE TROUGH DEVELOPS...RETURN SOUTHERLY FLOW WILL RESULT IN A
MODERATING TREND ON SUNDAY. HIGHS WILL BE SEASONABLE IN THE LOW TO
MID 80S. A COLD FRONT WILL APPROACH NORTHERN OKLAHOMA LATE MONDAY
INTO TUESDAY. THERE IS SOME UNCERTAINTY ON HOW FAR SOUTH THE FRONT
WILL GO. NEVERTHELESS...THE FRONT AND NORTHWEST FLOW ALOFT SUGGEST
AT LEAST LOW POPS ARE NEEDED LATE MONDAY THROUGH WEDNESDAY.
MAHALE
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 62 76 61 65 / 20 10 30 40
HOBART OK 60 76 59 67 / 20 10 30 50
WICHITA FALLS TX 65 80 64 72 / 40 30 50 50
GAGE OK 53 73 51 58 / 0 10 30 50
PONCA CITY OK 57 75 55 63 / 0 10 20 40
DURANT OK 68 80 68 72 / 60 40 60 50
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
04/10
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
443 PM EDT WED SEP 10 2014
.SYNOPSIS...
HIGH PRESSURE WEDGED ALONG AND EAST OF THE CENTRAL APPALACHIANS
WILL SHIFT EAST TONIGHT. A STRONG COLD FRONT TRAILING A DEEP
CYCLONE LIFTING THROUGH THE GREAT LAKES WILL MOVE ACROSS THE
REGION ON THURSDAY. COOLER AND DRY WEATHER WILL FOLLOW BEHIND THE
COLD FRONT ON FRIDAY. A SECONDARY FRONTAL SYSTEM WILL MOVE THROUGH
THE AREA ON SATURDAY BEFORE HIGH PRESSURE RETURNS FAIR WEATHER ON
SUNDAY. THE OVERALL PATTERN FAVORS BELOW NORMAL TEMPERATURES FROM
SATURDAY INTO NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
EARLY EVENING VISIBLE STLT LOOP SHOWS BREAKING STRATUS ACROSS MUCH
OF CENTRAL PA...WHILE CIRRUS IS ALEADY OVERSPREADING THE NW MTNS
IN ADVANCE OF LL JET/WAA OVR THE GRT LKS.
AN INTENSE SFC CYCLONE WILL TRACK NEWD ACRS THE GREAT LAKES THIS
EVE AND CROSS THE ONT/QUE BORDER BTWN 06-12Z THU. THE TRAILING
COLD FRONT SHOULD REACH A BUF-CMH LINE BY DAYBREAK THU WITH A STG
40-50KT SSWLY LLJ PROGGED AHEAD OF THE FRONT. THE LLJ WILL DRAW
VERY HIGH MSTR CONTENT AIR INTO CENTRAL PA AHEAD OF THE FRONT
WITH PWS AROUND 2 INCHES OR + 2 TO +3 SD ABOVE THE MEAN. THIS
WILL RESULT IN VERY HIGH MSTR FLUX ANOMALIES AND SUPPORT CATG POPS
OVER NWRN SXNS. IT WILL BE A WARM AND HUMID OVERNIGHT WITH TEMPS
HOLDING IN THE MID TO UPPER 60S. IT WILL BE BREEZY OVER THE WRN
HIGH TERRAIN AND ALLEGHENY RIDGES WITH GUSTS UP TO 30 MPH.
FOLLOWED THE LATEST HRRR FOR PCPN TIMING INTO TONIGHT. THE STG WAA
AND LLJ SUPPORTS A QUICKER EWD PROGRESSION OF LEADING EDGE LGT PCPN
THRU THE UPPER OH VLY AND INTO WRN PA BTWN 00-06Z. CVRG OF SHOWER
ACTIVITY AND SHALLOW/LOW-TOPPED CONVECTION SHOULD BE GREATEST
OVER THE WRN 1/3 OF THE AREA OVERNIGHT AND INTO EARLY THU MORNING
AHEAD OF THE COLD FRONT WITH LIMITED TS/LTG. HIGHEST QPF AMTS
/0.25-0.50 INCH/ ARE ALSO FOCUSED OVER THIS AREA.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
COLD FRONT TRAILING DEEP SFC LOW MOVG THRU QUE WILL BE FOCUS FOR
SHOWERS/TSTMS ON THU. THE MAIN CHANGE TO THE D2 FCST WAS FROM SPC
WHICH LOWERED THE RISK FOR SEVERE STORMS BY CUTTING OUT THE SLGT
RISK IN SCTNRL/SERN PA AND SHIFTING THE SEE TEXT/5% SVR PROBS SWD
INTO LWX CWA. THIS MAKES SENSE GIVEN EARLY MORNING CLOUDS/RAIN
RESULTING IN WEAK DIABATIC HEATING/INSTABILITY AND BEST
FORCING/SHEAR BEING DISPLACED WELL TO THE NORTH. UPDATED HWO WILL
BE ISSUED TO REFLECT THE LOWER SEVERE WX RISK...HOWEVER LCL GUSTY
WINDS WILL REMAIN PSBL IN ANY STRONGER ORGANIZED TSTM CELLS/CLUSTERS.
THE FRONT WILL EXIT THE SERN PRTNS OF THE CWA THU NGT WITH RAINS
ENDING FROM NW TO SE. VERY HIGH PWS WOULD SUPPORT SOME EFFICIENT
HEAVY DOWNPOURS BUT STORMS SHOULD BE MOVG SO HYDRO/FF CONCERNS ARE
LOW ATTM. COOLER TEMPS THU NGT AS NLY WINDS BRING DRIER AIR INTO
THE AREA BEHIND THE FIRST "FALL" FROPA.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
NOT A LOT OF CHANGE.
MODELS STILL SHOW NORTHERN BRANCH OF JET MOVING THINGS ALONG.
THUS DID EDGE TEMPS AND DEWPOINTS DOWN A LITTLE FOR FRIDAY.
FRIDAY STILL LOOKS DRY.
FOR SAT...STILL A CHC OF SHOWERS...GIVEN RATHER STRONG VORT
MAX IN NORTHERN BRANCH. MID SHIFT HAD BROUGHT POPS UP SOME.
I DID A LITTLE MORE. MOISTURE LIMITED...BUT DYNAMICS MAY
TRIGGER AN ISOLATED THUNDERSTORM.
LEFT SUNDAY INTO WED DRY.
SOME HINTS OF A WEAK TROUGH OVER THE LAKES EARLY NEXT WEEK...BUT
LEFT FCST DRY FOR NOW.
&&
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
LOW CIGS HAVE BEEN RATHER PERSISTENT OVER THE CENTRAL 2/3RDS OF
THE AIRSPACE AND GUID WAS TOO OPTIMISTIC ON AFTN IMPROVEMENT.
LATEST OBS TRENDS SHOW CIGS SLOWLY LIFTING AOA LOW MVFR
THRESHOLDS...WHILE CLOUDS CONTINUE TO ERODE ON THE WRN FLANKS OF
THE LOW CLOUD DECK - WEST OF THE ALLEGHENY FRONT. UPSTREAM
CUMULUS HAVE DEVELOPED IN THE PRE FRONTAL WARM SECTOR WERE THE SUN
IS OUT...QUICKLY BECOMING OVERTOPPED BY THICKENING MID TO HIGH
CLOUDS RACING EWD IN ASSOC WITH OH VLY CONVECTION. MAIN CHANGES
FOR THE 18Z SCHEDULED TAFS WAS TO INCREASE TOA FOR SHRA INTO THE
WRN AIRSPACE/ZOB SECTOR BASED ON COSPA/HRRR DATA. A VERY STRONG
SOUTHERLY FLOW/LLJ AHEAD OF THE MAIN COLD FRONT WILL RESULT IN
LLWS OVER WRN TERMINALS AFT 00Z...WHICH MAY NEED TO BE EXPANDED
INTO THE CENTRAL SITES. TOUGH CALL FOR CIG TRENDS OVER CNTRL/ERN
SXNS OVERNIGHT AS GUID WANTS TO LOWER CIGS DOWN TO IFR. FOR NOW
WILL PLAY THINGS MORE OPTIMISTICALLY WITH INCR SLY GRADIENT FLOW
SUGGESTIVE OF MORE MVFR TO LOW END VFR CIGS. FINALLY..THE LATEST
DATA SHOWS MORE CLOUDS/PCPN SPREADING INTO THE AIRSPACE THRU EARLY
TOMORROW. THIS SHOULD LIMIT HEATING AND ULTIMATELY THE RISK FOR
STG TO SVR STORM DEVELOPMENT. LATER TAFS WILL NEED TO REFINE
TIMING AND EXTENT OF PCPN CVRG.
OUTLOOK...
THU...SCT TO NMRS SHRA/TSTMS. COLD FROPA/WIND SHFT FM 180-270. AM
LOW CIGS PSBL BCMG VFR.
FRI...LOW CIGS PSBL EARLY OVR WRN 1/3...BCMG VFR.
SAT...VFR/MVFR CIGS WITH SCT SHOWERS/TSTMS.
SUN...PATCHY AM FOG...OTHERWISE VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...FITZGERALD/STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...MARTIN
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
356 PM EDT WED SEP 10 2014
.SYNOPSIS...
HIGH PRESSURE WEDGED ALONG AND EAST OF THE CENTRAL APPALACHIANS
WILL SHIFT EAST TONIGHT. A STRONG COLD FRONT TRAILING A DEEP
CYCLONE LIFTING THROUGH THE GREAT LAKES WILL MOVE ACROSS THE
REGION ON THURSDAY. COOLER AND DRY WEATHER WILL FOLLOW BEHIND THE
COLD FRONT ON FRIDAY. A SECONDARY FRONTAL SYSTEM WILL MOVE THROUGH
THE AREA ON SATURDAY BEFORE HIGH PRESSURE RETURNS FAIR WEATHER ON
SUNDAY. THE OVERALL PATTERN FAVORS BELOW NORMAL TEMPERATURES FROM
SATURDAY INTO NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
15-18Z VISIBLE STLT LOOP SHOWS PEAKS OF SUN ALONG THE ALLEGHENY
FRONT INTO THE SCNTRL MTNS..WHILE MUCH OF THE INTERIOR CWA REMAINS
M/CLOUDY FROM UNV TO SEG NWD TO THE NY BORDER. THE LATEST TRENDS
SUGGEST BINOVC DEVELOPING LOCALLY THRU 20Z.
AN INTENSE SFC CYCLONE WILL TRACK NEWD ACRS THE GREAT LAKES THIS
EVE AND CROSS THE ONT/QUE BORDER BTWN 06-12Z THU. THE TRAILING
COLD FRONT SHOULD REACH A BUF-CMH LINE BY DAYBREAK THU WITH A STG
40-50KT SSWLY LLJ PROGGED AHEAD OF THE FRONT. THE LLJ WILL DRAW
VERY HIGH MSTR CONTENT AIR INTO CENTRAL PA AHEAD OF THE FRONT
WITH PWS AROUND 2 INCHES OR + 2 TO +3 SD ABOVE THE MEAN. THIS
WILL RESULT IN VERY HIGH MSTR FLUX ANOMALIES AND SUPPORT CATG POPS
OVER NWRN SXNS. IT WILL BE A WARM AND HUMID OVERNIGHT WITH TEMPS
HOLDING IN THE MID TO UPPER 60S. IT WILL BE BREEZY OVER THE WRN
HIGH TERRAIN AND ALLEGHENY RIDGES WITH GUSTS UP TO 30 MPH.
FOLLOWED THE LATEST HRRR FOR PCPN TIMING INTO TONIGHT. THE STG WAA
AND LLJ SUPPORTS A QUICKER EWD PROGRESSION OF LEADING EDGE LGT PCPN
THRU THE UPPER OH VLY AND INTO WRN PA BTWN 00-06Z. CVRG OF SHOWER
ACTIVITY AND SHALLOW/LOW-TOPPED CONVECTION SHOULD GREATEST OVER
THE WRN 1/3 OF THE AREA OVERNIGHT AND INTO EARLY THU MORNING AHEAD
OF THE COLD FRONT WITH LIMITED TS/LTG. HIGHEST QPF AMTS /0.25-0.50
INCH/ ARE ALSO FOCUSED OVER THIS AREA.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
COLD FRONT TRAILING DEEP SFC LOW MOVG THRU QUE WILL BE FOCUS FOR
SHOWERS/TSTMS ON THU. THE MAIN CHANGE TO THE D2 FCST WAS FROM SPC
WHICH LOWERED THE RISK FOR SEVERE STORMS BY CUTTING OUT THE SLGT
RISK IN SCTNRL/SERN PA AND SHIFTING THE SEE TEXT/5% SVR PROBS SWD
INTO LWX CWA. THIS MAKES SENSE GIVEN EARLY MORNING CLOUDS/RAIN
RESULTING IN WEAK DIABATIC HEATING/INSTABILITY AND BEST
FORCING/SHEAR BEING DISPLACED WELL TO THE NORTH. UPDATED HWO WILL
BE ISSUED TO REFLECT THE LOWER SEVERE WX RISK...HOWEVER LCL GUSTY
WINDS WILL REMAIN PSBL IN ANY STRONGER ORGANIZED TSTM CELLS/CLUSTERS.
THE FRONT WILL EXIT THE SERN PRTNS OF THE CWA THU NGT WITH RAINS
ENDING FROM NW TO SE. VERY HIGH PWS WOULD SUPPORT SOME EFFICIENT
HEAVY DOWNPOURS BUT STORMS SHOULD BE MOVG SO HYDRO/FF CONCERNS ARE
LOW ATTM. COOLER TEMPS THU NGT AS NLY WINDS BRING DRIER AIR INTO
THE AREA BEHIND THE FIRST "FALL" FROPA.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
NOT A LOT OF CHANGE.
MODELS STILL SHOW NORTHERN BRANCH OF JET MOVING THINGS ALONG.
THUS DID EDGE TEMPS AND DEWPOINTS DOWN A LITTLE FOR FRIDAY.
FRIDAY STILL LOOKS DRY.
FOR SAT...STILL A CHC OF SHOWERS...GIVEN RATHER STRONG VORT
MAX IN NORTHERN BRANCH. MID SHIFT HAD BROUGHT POPS UP SOME.
I DID A LITTLE MORE. MOISTURE LIMITED...BUT DYNAMICS MAY
TRIGGER AN ISOLATED THUNDERSTORM.
LEFT SUNDAY INTO WED DRY.
SOME HINTS OF A WEAK TROUGH OVER THE LAKES EARLY NEXT WEEK...BUT
LEFT FCST DRY FOR NOW.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
LOW CIGS HAVE BEEN RATHER PERSISTENT OVER THE CENTRAL 2/3RDS OF
THE AIRSPACE AND GUID WAS TOO OPTIMISTIC ON AFTN IMPROVEMENT.
LATEST OBS TRENDS SHOW CIGS SLOWLY LIFTING AOA LOW MVFR
THRESHOLDS...WHILE CLOUDS CONTINUE TO ERODE ON THE WRN FLANKS OF
THE LOW CLOUD DECK - WEST OF THE ALLEGHENY FRONT. UPSTREAM
CUMULUS HAVE DEVELOPED IN THE PRE FRONTAL WARM SECTOR WERE THE SUN
IS OUT...QUICKLY BECOMING OVERTOPPED BY THICKENING MID TO HIGH
CLOUDS RACING EWD IN ASSOC WITH OH VLY CONVECTION. MAIN CHANGES
FOR THE 18Z SCHEDULED TAFS WAS TO INCREASE TOA FOR SHRA INTO THE
WRN AIRSPACE/ZOB SECTOR BASED ON COSPA/HRRR DATA. A VERY STRONG
SOUTHERLY FLOW/LLJ AHEAD OF THE MAIN COLD FRONT WILL RESULT IN
LLWS OVER WRN TERMINALS AFT 00Z...WHICH MAY NEED TO BE EXPANDED
INTO THE CENTRAL SITES. TOUGH CALL FOR CIG TRENDS OVER CNTRL/ERN
SXNS OVERNIGHT AS GUID WANTS TO LOWER CIGS DOWN TO IFR. FOR NOW
WILL PLAY THINGS MORE OPTIMISTICALLY WITH INCR SLY GRADIENT FLOW
SUGGESTIVE OF MORE MVFR TO LOW END VFR CIGS. FINALLY..THE LATEST
DATA SHOWS MORE CLOUDS/PCPN SPREADING INTO THE AIRSPACE THRU EARLY
TOMORROW. THIS SHOULD LIMIT HEATING AND ULTIMATELY THE RISK FOR
STG TO SVR STORM DEVELOPMENT. LATER TAFS WILL NEED TO REFINE
TIMING AND EXTENT OF PCPN CVRG.
OUTLOOK...
THU...SCT TO NMRS SHRA/TSTMS. COLD FROPA/WIND SHFT FM 180-270. AM
LOW CIGS PSBL BCMG VFR.
FRI...LOW CIGS PSBL EARLY OVR WRN 1/3...BCMG VFR.
SAT...VFR/MVFR CIGS WITH SCT SHOWERS/TSTMS.
SUN...PATCHY AM FOG...OTHERWISE VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...MARTIN
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
258 PM EDT WED SEP 10 2014
.SYNOPSIS...
HIGH PRESSURE WEDGED ALONG AND EAST OF THE CENTRAL APPALACHIANS
WILL SHIFT EAST TONIGHT. A STRONG COLD FRONT TRAILING A DEEP
CYCLONE LIFTING THROUGH THE GREAT LAKES WILL MOVE ACROSS THE
REGION ON THURSDAY. COOLER AND DRY WEATHER WILL FOLLOW BEHIND THE
COLD FRONT ON FRIDAY. A SECONDARY FRONTAL SYSTEM WILL MOVE THROUGH
THE AREA ON SATURDAY BEFORE HIGH PRESSURE RETURNS FAIR WEATHER ON
SUNDAY. THE OVERALL PATTERN FAVORS BELOW NORMAL TEMPERATURES FROM
SATURDAY INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
15-18Z VISIBLE STLT LOOP SHOWS PEAKS OF SUN ALONG THE ALLEGHENY
FRONT INTO THE SCNTRL MTNS..WHILE MUCH OF THE INTERIOR CWA REMAINS
M/CLOUDY FROM UNV TO SEG NWD TO THE NY BORDER. THE LATEST TRENDS
SUGGEST BINOVC DEVELOPING LOCALLY THRU 20Z.
AN INTENSE SFC CYCLONE WILL TRACK NEWD ACRS THE GREAT LAKES THIS
EVE AND CROSS THE ONT/QUE BORDER BTWN 06-12Z THU. THE TRAILING
COLD FRONT SHOULD REACH A BUF-CMH LINE BY DAYBREAK THU WITH A STG
40-50KT SSWLY LLJ PROGGED AHEAD OF THE FRONT. THE LLJ WILL DRAW
VERY HIGH MSTR CONTENT AIR INTO CENTRAL PA AHEAD OF THE FRONT
WITH PWS AROUND 2 INCHES OR + 2 TO +3 SD ABOVE THE MEAN. THIS
WILL RESULT IN VERY HIGH MSTR FLUX ANOMALIES AND SUPPORT CATG POPS
OVER NWRN SXNS. IT WILL BE A WARM AND HUMID OVERNIGHT WITH TEMPS
HOLDING IN THE MID TO UPPER 60S. IT WILL BE BREEZY OVER THE WRN
HIGH TERRAIN AND ALLEGHENY RIDGES WITH GUSTS UP TO 30 MPH.
FOLLOWED THE LATEST HRRR FOR PCPN TIMING INTO TONIGHT. THE STG WAA
AND LLJ SUPPORTS A QUICKER EWD PROGRESSION OF LEADING EDGE LGT PCPN
THRU THE UPPER OH VLY AND INTO WRN PA BTWN 00-06Z. CVRG OF SHOWER
ACTIVITY AND SHALLOW/LOW-TOPPED CONVECTION SHOULD GREATEST OVER
THE WRN 1/3 OF THE AREA OVERNIGHT AND INTO EARLY THU MORNING AHEAD
OF THE COLD FRONT WITH LIMITED TS/LTG. HIGHEST QPF AMTS /0.25-0.50
INCH/ ARE ALSO FOCUSED OVER THIS AREA.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
COLD FRONT TRAILING DEEP SFC LOW MOVG THRU QUE WILL BE FOCUS FOR
SHOWERS/TSTMS ON THU. THE MAIN CHANGE TO THE D2 FCST WAS FROM SPC
WHICH LOWERED THE RISK FOR SEVERE STORMS BY CUTTING OUT THE SLGT
RISK IN SCTNRL/SERN PA AND SHIFTING THE SEE TEXT/5% SVR PROBS SWD
INTO LWX CWA. THIS MAKES SENSE GIVEN EARLY MORNING CLOUDS/RAIN
RESULTING IN WEAK DIABATIC HEATING/INSTABILITY AND BEST
FORCING/SHEAR BEING DISPLACED WELL TO THE NORTH. UPDATED HWO WILL
BE ISSUED TO REFLECT THE LOWER SEVERE WX RISK...HOWEVER LCL GUSTY
WINDS WILL REMAIN PSBL IN ANY STRONGER ORGANIZED TSTM CELLS/CLUSTERS.
THE FRONT WILL EXIT THE SERN PRTNS OF THE CWA THU NGT WITH RAINS
ENDING FROM NW TO SE. VERY HIGH PWS WOULD SUPPORT SOME EFFICIENT
HEAVY DOWNPOURS BUT STORMS SHOULD BE MOVG SO HYDRO/FF CONCERNS ARE
LOW ATTM. COOLER TEMPS THU NGT AS NLY WINDS BRING DRIER AIR INTO
THE AREA BEHIND THE FIRST "FALL" FROPA.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
FRIDAY STILL LOOKS DRY. DID UP MAX TEMPS SOME.
FOR SAT...STILL A CHC OF SHOWERS...GIVEN RATHER STRONG VORT
MAX IN NORTHERN BRANCH. TOOK OUT THUNDER.
WENT WITH A DRY FCST AFT 04Z SUNDAY...AS HEIGHTS COME BACK
UP TO 570 NEAR THE LOWER LAKES...TOO WARM FOR ANYTHING OFF
THE LAKES...EVEN WITH W TO NW FLOW.
SOME HINTS OF A WEAK TROUGH OVER THE LAKES EARLY NEXT WEEK...BUT
LEFT FCST DRY FOR NOW.
&&
.AVIATION /18Z WEDNESDAY THROUGH SUNDAY/...
LOW CIGS HAVE BEEN RATHER PERSISTENT OVER THE CENTRAL 2/3RDS OF
THE AIRSPACE AND GUID WAS TOO OPTIMISTIC ON AFTN IMPROVEMENT.
LATEST OBS TRENDS SHOW CIGS SLOWLY LIFTING AOA LOW MVFR
THRESHOLDS...WHILE CLOUDS CONTINUE TO ERODE ON THE WRN FLANKS OF
THE LOW CLOUD DECK - WEST OF THE ALLEGHENY FRONT. UPSTREAM
CUMULUS HAVE DEVELOPED IN THE PRE FRONTAL WARM SECTOR WERE THE SUN
IS OUT...QUICKLY BECOMING OVERTOPPED BY THICKENING MID TO HIGH
CLOUDS RACING EWD IN ASSOC WITH OH VLY CONVECTION. MAIN CHANGES
FOR THE 18Z SCHEDULED TAFS WAS TO INCREASE TOA FOR SHRA INTO THE
WRN AIRSPACE/ZOB SECTOR BASED ON COSPA/HRRR DATA. A VERY STRONG
SOUTHERLY FLOW/LLJ AHEAD OF THE MAIN COLD FRONT WILL RESULT IN
LLWS OVER WRN TERMINALS AFT 00Z...WHICH MAY NEED TO BE EXPANDED
INTO THE CENTRAL SITES. TOUGH CALL FOR CIG TRENDS OVER CNTRL/ERN
SXNS OVERNIGHT AS GUID WANTS TO LOWER CIGS DOWN TO IFR. FOR NOW
WILL PLAY THINGS MORE OPTIMISTICALLY WITH INCR SLY GRADIENT FLOW
SUGGESTIVE OF MORE MVFR TO LOW END VFR CIGS. FINALLY..THE LATEST
DATA SHOWS MORE CLOUDS/PCPN SPREADING INTO THE AIRSPACE THRU EARLY
TOMORROW. THIS SHOULD LIMIT HEATING AND ULTIMATELY THE RISK FOR
STG TO SVR STORM DEVELOPMENT. LATER TAFS WILL NEED TO REFINE
TIMING AND EXTENT OF PCPN CVRG.
OUTLOOK...
THU...SCT TO NMRS SHRA/TSTMS. COLD FROPA/WIND SHFT FM 180-270. AM
LOW CIGS PSBL BCMG VFR.
FRI...LOW CIGS PSBL EARLY OVR WRN 1/3...BCMG VFR.
SAT...VFR/MVFR CIGS WITH SCT SHOWERS/TSTMS.
SUN...PATCHY AM FOG...OTHERWISE VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...LAMBERT/MARTIN
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
305 PM CDT WED SEP 10 2014
.SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT
CLOUDY AND COLD IS THE STORY ACROSS THE REGION THIS AFTERNOON. IN
FACT...SOME LOCATIONS WILL LIKELY SET RECORDS FOR THE COLDEST
HIGH TEMPERATURE EVER RECORDED ON THIS DATE. CWA IS CURRENTLY DRY
BUT WATCHING THE BEGINNINGS OF THE NEXT SYSTEM MOVING ACROSS
NORTHWEST SD. TREND FOR TONIGHT WILL BE FOR PRECIP TO MAINLY
AFFECT WESTERN AND CENTRAL SD...AND MAY EVEN GET COLD ENOUGH LATE
TONIGHT AND EARLY THURSDAY MORNING TO ALLOW FOR A RAIN/SNOW MIX
ACROSS THE FAR NORTHWEST CWA. TARGET AREA FOR ACCUMULATING SNOW
THOUGH STILL REMAINS OVER FAR WESTERN SD AND THE BLACK HILLS. WILL
HAVE TO WATCH CLOUD COVER TRENDS OVERNIGHT ACROSS THE
NORTHERN/NORTHEAST CWA AS CIGS HAVE THINNED AND HAVE EVEN REVEALED
SOME HOLES. RAP MODEL 925-850MB RH SHOWS THIS DRIER AREA
NICELY...AND BRINGS IN OVER THE NORTHERN COUNTIES LATER TONIGHT.
IF ANY BREAKS OR THINNING OCCUR...TEMPS COULD FALL PRETTY NICELY.
BUT OVERALL...THE ABUNDANCE OF MID AND HIGH CLOUDS WITH THE NEXT
APPROACHING WAVE...AND THE OVERALL WINDS STAYING UP A TOUCH SHOULD
PREVENT THE BOTTOM FROM FALLING OUT ON TEMPS.
ATTENTION THEN TURNS TO THURSDAY NIGHT AND FRIDAY MORNING AND THE
POTENTIAL FOR FROST. MODELS CONTINUE TO SHIFT PRECIP AND CLOUDS A
BIT FURTHER SOUTH AND EAST DURING THIS TIME...A BIT QUICKER THAN
PREVIOUS RUNS...AND THE PREVIOUSLY SLOWER EC IS NOW COMING AROUND
TO THE FASTER SOLUTIONS OTHER MODELS HAVE BEEN SHOWING. THIS MEANS
A BETTER POTENTIAL FOR FROST CONDITIONS AND TEMPS IN THE LOW TO
MID 30S OVER A GOOD PORTION OF THE CWA. INSERTED FROST INTO THE
GRIDS ALONG AND WEST OF THE JAMES VALLEY AND COULD VERY WELL BE
HEADING TOWARDS A FROST ADVISORY AT SOME POINT. IT WILL ALL DEPEND
ON HOW MUCH CLOUD COVER LINGERS OVER THE AREA...THE CLEARER THE
SKIES THE BETTER THE TEMPS WILL FALL.
FOR FRIDAY NIGHT AND SATURDAY...MODELS SEEM TO BE NUDGING THE HIGH
CENTER TO THE EAST A TAD QUICKER. WHAT THIS MEANS IS THAT A
SLIGHTLY STRONGER GRADIENT SETS UP FRIDAY NIGHT WITH SOUTH WINDS
PICKING UP. WHETHER OR NOT THESE WINDS ARE STRONG ENOUGH ALONG AND
EAST OF THE JAMES VALLEY TO PREVENT TEMPS FROM REACHING THE LOW TO
MID 30S IS DOUBTFUL. WEST OF THERE...PROBABLY YES. CANNOT RULE OUT
FROST FRIDAY NIGHT/SATURDAY MORNING EITHER...BUT BEST POTENTIAL
HERE WILL BE ACROSS THE EASTERN CWA.
.LONG TERM...SATURDAY THROUGH WEDNESDAY
NOT MUCH CHANGE IN THE EXTENDED FROM 24 HOURS AGO. 12Z MODEL
SOLUTIONS POINT TO A BIT OF WARMING ON SATURDAY OUT AHEAD OF AN
APPROACHING COLD FRONT. ANOTHER SURFACE HIGH PRESSURE SYSTEM
BUILDS DOWN FOR SUNDAY AND MONDAY...BUT THEN SHIFTS SOUTH AND EAST
OF THE AREA...ALLOWING FOR RETURN FLOW WARMING WINDS TUESDAY AND
WEDNESDAY. PRECIPITATION CHANCES REALLY ARE FEW AND FAR BETWEEN IN
THE OUT PERIODS...WITH THE "BEST" CHANCES FOR A FEW RAIN
SHOWERS SHOWING UP SUNDAY AFTERNOON/EVENING BEHIND THIS COLD
FROPA.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
CONDITIONS ARE IMPROVING ACROSS THE REGION. KMBG HAS BEGUN
BOUNCING IN AND OUT OF VFR/MVFR...AND KATY IS SLOWLY TRENDING
TOWARD AN MVFR CIG. KPIR/KABR REMAIN MVFR AS WELL...BUT SATELLITE
TRENDS AND SHORT RANGE RAPID REFRESH MODEL OUTPUT ALL POINT TO
VFR RETURNING TO THE REGION AS THE PREVAILING CONDITION BY 00Z
THIS EVENING AT KABR/KPIR AND KMBG...WITH KATY FOLLOWING BY 06Z.
THE RAPID REFRESH MODEL IS ALSO TAKING PRECIP CHANCES SOUTH LATER
THIS EVENING...WITH THE BULK OF ANY PRECIP CHANCES WITH THIS NEXT
LITTLE WAVE OF LOW PRESSURE RE-ALIGNING TOWARD THE KPIR AREA LATER
AT OR AFTER MIDNIGHT.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...TMT
LONG TERM...DORN
AVIATION...DORN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
115 PM CDT WED SEP 10 2014
.UPDATE...
DECIDED TO PULL THE TRIGGER ON LOWERING THE MAX T GRID ACROSS THE
BOARD FOR THIS AFTERNOON. HOURLY FORECAST WAS TRENDING ABOUT 2-4
DEGREES BELOW REALITY AND WITH THE SKIES MOSTLY CLOUD COVERED AND
SHOULD REMAIN THAT WAY...DONT THINK WE WILL HIT THE PREVIOUSLY
ADVERTISED HIGHS.
ALSO RAISED POPS IN THE WEST DUE TO THE ISOLATED SHOWERS POPPING
UP WEST OF I65. WITH IT BEING ONLY 18Z AND A BIT MORE CONVECTIVE
POTENTIAL IS EXPECTED WITH A VERY MOIST ATMOSPHERE...THINK THIS IS
PROBABLY A SAFE BET.
&&
.PREV DISCUSSION... /ISSUED 1204 PM CDT WED SEP 10 2014/
AVIATION UPDATE...FOR 18Z TAF PACKAGE...
MVFR CONDITIONS CONTINUE TO PERSIST FOR KCKV AND KBNA. SHOULD SEE
A BRIEF IMPROVEMENT BUT PROBABLY NOT UNTIL AFTER DARK. AN
APPROACHING COLD FRONT WILL CONTINUE TO INCREASE CLOUD COVERAGE
ALTHOUGH A CEILINGS SHOULD RISE TO VFR HEIGHTS BRIEFLY BEFORE THE
RAIN ARRIVES. INCLUDED -SHRA MENTION BEGINNING JUST BEFORE
MIDNIGHT FOR KCKV. ACTIVITY SHOULD PROGRESS EASTWARD SLOWLY AND
IMPACT KBNA BY JUST BEFORE DAWN. LEFT RAIN OUT OF KCSV FOR NOW BUT
DID MENTION MVFR BR POSSIBILITIES IN THE EARLY MORNING THERE.
PREV DISCUSSION... /ISSUED 1141 AM CDT WED SEP 10 2014/
UPDATE...
WITH THE APPROACHING COLD FRONT BRINGING A BROKEN DECK OF HIGH
CLOUDS FOR MUCH OF THE WESTERN HALF OF THE CWA...AND BOUNDARY
LAYER CONVECTIVE CU BEGINNING TO FORM AS WELL...OPTED TO INCREASE
THE SKY GRIDS TO MOSTLY CLOUDY WORDING THROUGH THE EVENING.
VIS SATELLITE IS SHOWING AN AREA OF CONFLUENCE IN NORTHERN MS AND
WESTERN TN. THIS IS JUST AHEAD OF THE CURRENT ACTIVITY APPROACHING
THE MO BOOTHEEL WHICH MAY PROVIDE ENOUGH BOUNDARY LAYER
CONVERGENCE TO PRODUCE ISOLATED SHOWER AND STORM DEVELOPMENT OVER
THE NEXT COUPLE HOURS. HRRR SEEMS TO AGREE BUT IS A BIT EARLY ON
THE DEVELOPMENT. SOME OF THOSE SHOWERS MAY IMPACT OUR CWA WEST OF
THE I65 CORRIDOR MAINLY. WE CURRENTLY HAVE SLIGHT CHANCE POPS IN
THE GRIDS FOR THE AFTERNOON AND WITH THE EXPECTED ISOLATED NATURE
OF THE DEVELOPMENT...DONT SEE A REASON TO INCREASE TO CHC POPS
JUST YET. MAY NEED ANOTHER UPDATE IF THINGS ARE A BIT MORE SUBSTANTIAL.
ALSO KEEPING AN EYE ON THE MAX T AS CLOUDS CONTINUE TO LIMIT
WARMING...WE ARE ABOUT 2-3 DEGREES BELOW THE FORECAST HOURLY TEMPS
ACROSS THE BOARD SO IF THAT PERSISTS...MAY NEED TO LOWER THE MAX T
GRID AS WELL. WILL REEVALUATE AT 18Z.
PREV DISCUSSION... /ISSUED 625 AM CDT WED SEP 10 2014/
AVIATION...BNA/CKV/CSV...LOW CLOUDS AT CSV SHOULD GIVE WAY BY 15Z
OR SO. LOOK FOR WINDS TO INCREASE THIS MORNING AHEAD OF A SLOW-
MOVING COLD FRONT. VFR CIGS WILL COVER MIDDLE TENNESSEE MOST OF
TODAY AND TONIGHT WITH SHRA AND POSSIBLE TSRA MOVING INTO NW
MIDDLE TENNESSEE OVERNIGHT.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
TB12
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1204 PM CDT WED SEP 10 2014
.AVIATION UPDATE...FOR 18Z TAF PACKAGE...
MVFR CONDITIONS CONTINUE TO PERSIST FOR KCKV AND KBNA. SHOULD SEE
A BRIEF IMPROVEMENT BUT PROBABLY NOT UNTIL AFTER DARK. AN
APPROACHING COLD FRONT WILL CONTINUE TO INCREASE CLOUD COVERAGE
ALTHOUGH A CEILINGS SHOULD RISE TO VFR HEIGHTS BRIEFLY BEFORE THE
RAIN ARRIVES. INCLUDED -SHRA MENTION BEGINNING JUST BEFORE
MIDNIGHT FOR KCKV. ACTIVITY SHOULD PROGRESS EASTWARD SLOWLY AND
IMPACT KBNA BY JUST BEFORE DAWN. LEFT RAIN OUT OF KCSV FOR NOW BUT
DID MENTION MVFR BR POSSIBILITIES IN THE EARLY MORNING THERE.
&&
.PREV DISCUSSION... /ISSUED 1141 AM CDT WED SEP 10 2014/
UPDATE...
WITH THE APPROACHING COLD FRONT BRINGING A BROKEN DECK OF HIGH
CLOUDS FOR MUCH OF THE WESTERN HALF OF THE CWA...AND BOUNDARY
LAYER CONVECTIVE CU BEGINNING TO FORM AS WELL...OPTED TO INCREASE
THE SKY GRIDS TO MOSTLY CLOUDY WORDING THROUGH THE EVENING.
VIS SATELLITE IS SHOWING AN AREA OF CONFLUENCE IN NORTHERN MS AND
WESTERN TN. THIS IS JUST AHEAD OF THE CURRENT ACTIVITY APPROACHING
THE MO BOOTHEEL WHICH MAY PROVIDE ENOUGH BOUNDARY LAYER
CONVERGENCE TO PRODUCE ISOLATED SHOWER AND STORM DEVELOPMENT OVER
THE NEXT COUPLE HOURS. HRRR SEEMS TO AGREE BUT IS A BIT EARLY ON
THE DEVELOPMENT. SOME OF THOSE SHOWERS MAY IMPACT OUR CWA WEST OF
THE I65 CORRIDOR MAINLY. WE CURRENTLY HAVE SLIGHT CHANCE POPS IN
THE GRIDS FOR THE AFTERNOON AND WITH THE EXPECTED ISOLATED NATURE
OF THE DEVELOPMENT...DONT SEE A REASON TO INCREASE TO CHC POPS
JUST YET. MAY NEED ANOTHER UPDATE IF THINGS ARE A BIT MORE SUBSTANTIAL.
ALSO KEEPING AN EYE ON THE MAX T AS CLOUDS CONTINUE TO LIMIT
WARMING...WE ARE ABOUT 2-3 DEGREES BELOW THE FORECAST HOURLY TEMPS
ACROSS THE BOARD SO IF THAT PERSISTS...MAY NEED TO LOWER THE MAX T
GRID AS WELL. WILL REEVALUATE AT 18Z.
PREV DISCUSSION... /ISSUED 625 AM CDT WED SEP 10 2014/
AVIATION...BNA/CKV/CSV...LOW CLOUDS AT CSV SHOULD GIVE WAY BY 15Z
OR SO. LOOK FOR WINDS TO INCREASE THIS MORNING AHEAD OF A SLOW-
MOVING COLD FRONT. VFR CIGS WILL COVER MIDDLE TENNESSEE MOST OF
TODAY AND TONIGHT WITH SHRA AND POSSIBLE TSRA MOVING INTO NW
MIDDLE TENNESSEE OVERNIGHT.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
TB12
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1141 AM CDT WED SEP 10 2014
.UPDATE...
WITH THE APPROACHING COLD FRONT BRINGING A BROKEN DECK OF HIGH
CLOUDS FOR MUCH OF THE WESTERN HALF OF THE CWA...AND BOUNDARY
LAYER CONVECTIVE CU BEGINNING TO FORM AS WELL...OPTED TO INCREASE
THE SKY GRIDS TO MOSTLY CLOUDY WORDING THROUGH THE EVENING.
VIS SATELLITE IS SHOWING AN AREA OF CONFLUENCE IN NORTHERN MS AND
WESTERN TN. THIS IS JUST AHEAD OF THE CURRENT ACTIVITY APPROACHING
THE MO BOOTHEEL WHICH MAY PROVIDE ENOUGH BOUNDARY LAYER
CONVERGENCE TO PRODUCE ISOLATED SHOWER AND STORM DEVELOPMENT OVER
THE NEXT COUPLE HOURS. HRRR SEEMS TO AGREE BUT IS A BIT EARLY ON
THE DEVELOPMENT. SOME OF THOSE SHOWERS MAY IMPACT OUR CWA WEST OF
THE I65 CORRIDOR MAINLY. WE CURRENTLY HAVE SLIGHT CHANCE POPS IN
THE GRIDS FOR THE AFTERNOON AND WITH THE EXPECTED ISOLATED NATURE
OF THE DEVELOPMENT...DONT SEE A REASON TO INCREASE TO CHC POPS
JUST YET. MAY NEED ANOTHER UPDATE IF THINGS ARE A BIT MORE SUBSTANTIAL.
ALSO KEEPING AN EYE ON THE MAX T AS CLOUDS CONTINUE TO LIMIT
WARMING...WE ARE ABOUT 2-3 DEGREES BELOW THE FORECAST HOURLY TEMPS
ACROSS THE BOARD SO IF THAT PERSISTS...MAY NEED TO LOWER THE MAX T
GRID AS WELL. WILL REEVALUATE AT 18Z.
&&
.PREV DISCUSSION... /ISSUED 625 AM CDT WED SEP 10 2014/
AVIATION...BNA/CKV/CSV...LOW CLOUDS AT CSV SHOULD GIVE WAY BY 15Z
OR SO. LOOK FOR WINDS TO INCREASE THIS MORNING AHEAD OF A SLOW-
MOVING COLD FRONT. VFR CIGS WILL COVER MIDDLE TENNESSEE MOST OF
TODAY AND TONIGHT WITH SHRA AND POSSIBLE TSRA MOVING INTO NW
MIDDLE TENNESSEE OVERNIGHT.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
TB12
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
853 PM CDT THU SEP 11 2014
.UPDATE...
A POTENT UPPER TROUGH IS NOW SWINGING INTO THE NORTHERN PLAINS
AND AN UNSEASONABLY COLD AIR MASS HAS INVADED MUCH OF THE GREAT
PLAINS REGION. TEMPERATURES IN THE 40S EXTEND AS FAR SOUTH AS NW
KANSAS WITH READINGS IN THE 30S FARTHER NORTHWEST NEAR THE CORE OF
A 1035 MB HIGH PRESSURE CELL. AGAIN THIS IS UNUSUALLY COLD FOR
THIS TIME OF DAY IN EARLY TO MID SEPTEMBER. THE SURFACE HIGH WILL
CONTINUE TO DROP SOUTHEAST AND SEND A REINFORCING SURGE OF COLD
AIR SOUTH IN THE REGION BY MORNING. NORTH WINDS WILL INCREASE
DURING THE DAY...LIKELY INTO THE 15 TO 20 MPH RANGE BY MID-LATE
AFTERNOON. FORECASTED HIGH TEMPS FOR TOMORROW LOOK GOOD...BUT DUE
TO THE STRONG COLD ADVECTION...DID UPDATE TO SHOW FALLING
TEMPERATURES DURING THE AFTERNOON HOURS BEHIND THE FRONT. IT
CERTAINLY WILL FEEL FALL-LIKE TOMORROW. ALSO LOWERED LOW TEMPS
FRIDAY NIGHT A FEW DEGREES ACROSS THE WESTERN AND CENTRAL ZONES IN
ACCORDANCE WITH THE WRF FORECASTS...WHICH ARE USUALLY SUPERIOR
WITH TEMPS IN THIS PATTERN.
AS FAR AS RAIN CHANCES GO...WE ARE IN A LULL THIS EVENING AS
EXPECTED...BUT ALL GUIDANCE CONTINUES TO ADVERTISE AN INCREASE IN
ISENTROPIC ASCENT NEAR 700-850MB WHERE PARCELS ARE CONVECTIVELY
UNSTABLE. MOST OF THIS ELEVATED CONVECTION WILL FORM PRIMARILY
NORTHEAST OF A BOWIE TO DFW TO CORSICANA LINE AFTER MIDNIGHT
WHERE THE ISENTROPIC LIFT...MOISTURE AND INSTABILITY ALL ALIGN
BEST. WHEN THE REINFORCING COLD FRONT ARRIVES AFTER
SUNRISE...FRONTOGENETIC FORCING WILL RAMP UP AND AID IN ADDITIONAL
LIFT WITH A BAND OF RAIN/STORMS FORMING ROUGHLY ALONG A COMANCHE
TO DFW TO PARIS LINE BY MID MORNING. THIS ACTIVITY WILL GRADUALLY
WORK/DEVELOP SOUTHEASTWARD DURING THE DAY...BUT LIKELY WILL NOT
MAINTAIN A SOLID/CONTINUOUS LINE AS IT DOES SO. ALL IN ALL NO
CHANGE TO THE PRECIP FORECAST WAS REQUIRED.
TR.92
&&
.AVIATION...
/ISSUED 639 PM CDT THU SEP 11 2014/
TSRA DECREASING WITH LOSS OF HEATING...BUT WARM ADVECTION PATTERN
WILL SET UP LATER THIS EVENING AND STORMS WILL INCREASE AGAIN
NORTH OF THE FRONT. THIS ALREADY APPEARS TO BE THE CASE FROM THE
LOWER PECOS VALLEY TO HILL COUNTRY. STORMS ARE EXPECTED TO EXPAND
INTO THE DFW METROPLEX LATE TONIGHT...AND HAVE KEPT THE 10Z-14Z
TIME FRAME FOR TSRA IN THE TAF. COVERAGE WILL BE SCATTERED SO HAVE
KEPT VCTS FOR NOW. THERE IS POTENTIAL FOR SOME HEAVY RAIN SO IF
ONE OF THOSE CELLS MOVES OVER AN AIRPORT EXPECT IFR VISIBILITIES
IN PRECIPITATION.
WACO APPEARS TO BE TOO FAR SOUTH FOR THE WARM ADVECTION STORMS
TONIGHT...BUT THEY SHOULD DEVELOP MVFR CEILINGS OVERNIGHT AND
WILL LIKELY REMAIN MVFR FOR MOST OF THE DAY TOMORROW. THERE MAY BE
A TSRA CHANCE FOR FRIDAY AFTERNOON AT WACO...WILL SEE WHAT THE 00Z
MODELS HAVE TO SAY AND PUT TSRA IN WITH 06Z TAFS IF IT IS NEEDED. 84
&&
.PREV DISCUSSION... /ISSUED 321 PM CDT THU SEP 11 2014/
PLENTY OF CHALLENGES THIS FORECAST PACKAGE AS WE TRACK A SLOW-
MOVING FRONT NOW EXTENDING FROM A GATESVILLE...TO CORSICANA...TO
CANTON LINE. A BROKEN LINE OF SHOWERS AND THUNDERSTORMS CONTAINING
LOCALLY HEAVY RAINFALL HAS ERUPTED IN THE PAST 1-2 HOURS ALONG THE
BOUNDARY. IN ADDITION...LOCALIZED FLOODING ISSUES WILL NEED TO BE
MONITORED ALONG THE COLD FRONT WITH THIS BROKEN LINE OF STORMS
WITH RICH PRECIPITABLE WATER VALUES WELL ABOVE 2 INCHES AND HIGH
THETA-E AIR BETWEEN 700-850MB. ANY TRAINING ACTIVITY WILL LIKELY
CAUSE SOME LOCALIZED HYDROLOGIC PROBLEMS. WE WILL CARRY THE HIGHEST
RAIN CHANCES THIS EVENING ALONG AND AHEAD OF THE FRONT OR ACROSS
THE SOUTHEAST HALF OF THE REGION. THE BEST INSTABILITY AND FORCING
WITH THE COLD FRONT WILL MOST LIKELY DRIVE THIS ACTIVITY THROUGH
NIGHTFALL. IN ADDITION...WE HAVE ADDED HIGHER CHANCES ACROSS THE
FAR WESTERN COUNTIES FOR LATE EVENING. THE APPROACH OF A SUBTLE
DISTURBANCE OVER WEST TEXAS WILL LIKELY PROVIDE ENOUGH LIFT TO
SUSTAIN A FEW SHOWER OR STORMS ACROSS THE FAR WESTERN COUNTIES
AFTER SUNSET.
THE WEST TEXAS DISTURBANCE WILL CONTINUE TO MOVE OVER THE RED RIVER
AREA AND SOUTHERN OKLAHOMA TONIGHT. NORTHERN AREAS...ESPECIALLY
THOSE ALONG AND NORTH OF I-20 WILL BE UNDERNEATH THE RIGHT ENTRANCE
REGION OF A 60-70KT JET STREAK STREAMING OVER OKLAHOMA. AS WE HEAD
INTO FRIDAY MORNING...A STRONGER DISTURBANCE CURRENTLY OVER WYOMING
WILL ROTATE SOUTHEAST OVER THE KANSAS/NEBRASKA BORDER AND SHOULD
SHUNT THE JET STREAK A LITTLE FURTHER SOUTH. THE COMBINATION OF
THESE FEATURES WILL PROVIDE THE SYNOPTIC LIFT...WHILE NOCTURNAL
LOW LEVEL WARM ADVECTION OVERRIDES THE SHALLOW FRONTAL INVERSION.
WITH THE FOCUS SHIFTING BACK NORTH...WILL MAINTAIN LIKELY CHANCES
FOR RAINFALL WHICH AT TIMES COULD BE LOCALLY HEAVY...BUT NOT ENOUGH
ALONG WITH ANTECEDENT DRY SOIL CONDITIONS TO ISSUE ANY FLOOD WATCHES
AT THIS POINT. 500-700MB LAPSE RATES WILL BE HOVERING AROUND 6 DEG/KM
WITH BOTH RUC AND NAM12 BUFKIT SOUNDINGS INDICATING A DEEP...BUT
SKINNY LAYER OF CAPE. ALL TOLD...SHOWERS WILL BE LIKELY OVERNIGHT
TONIGHT INTO FRIDAY MORNING ACROSS THESE AREAS WITH EMBEDDED/ELEVATED
THUNDERSTORMS AT TIMES. RAIN CHANCES AFTER NIGHTFALL ACROSS CENTRAL
TEXAS SHOULD DIMINISH TO LOWER CHANCES THAN WHAT WILL BE SEEN
ACROSS THE NORTH. THERE WILL BE QUITE A VARIANCE ON HIGH TEMPERATURES
FROM NORTHWEST TO SOUTHEAST FRIDAY. HIGHS WILL ONLY PUSH TO AROUND
70 DEGREES ACROSS THE FAR NORTHWEST... TO THE LOWER 90S ACROSS THE
FAR SOUTHEAST.
BETTER RAIN CHANCES SHIFT BACK OVER CENTRAL TEXAS ONCE AGAIN
FRIDAY AFTERNOON INTO SATURDAY MORNING. THE PASSAGE OF THE STRONG
SHORTWAVE TO THE NORTH TOWARD NORTHERN MISSOURI AND IOWA WILL HELP
SEND A STRONGER AND DEEPER PUSH OF COOLER AIR INTO THE NORTHERN
COUNTIES WITH THE SOUTH REMAINING WARMER AND MORE UNSTABLE. THE
UPPER HIGH WILL STRENGTHEN SOME BACK OVER THE AREA THIS WEEKEND
WITH JUST LINGERING LOW RAIN CHANCES ACROSS CENTRAL TEXAS WHERE
DEEPER MOISTURE WILL LINGER. THESE CHANCES SHOULD END BY NIGHTFALL
SATURDAY EVENING AS THE ATMOSPHERE STABILIZES. EVEN SO...CLOUD
COVER ON AND ABOVE THE DEEPENING FRONTAL INVERSION WILL MAINTAIN
CONSIDERABLE CLOUDINESS ACROSS THE REGION. THE CLOUDS COMBINED
WITH THE COOLER AIRMASS WILL HOLD HIGHS BETWEEN 75 AND 85 DEGREES
SATURDAY THAT WILL SLOWLY MODIFY TO THE 80S ON SUNDAY.
THE FORECAST AFTER THE WEEKEND BECOMES CHALLENGING ONCE AGAIN AS
WE MONITOR AN UPPER DISTURBANCE ROTATING AROUND THE WESTERN PERIPHERY
OF THE UPPER HIGH OVER THE WESTERN GULF COAST ON MONDAY. BY MONDAY
NIGHT AND TUESDAY...ANOTHER STRONG DISTURBANCE WILL MOVE DOWN
WITHIN NORTHWEST FLOW ALOFT ACROSS THE CENTRAL PLAINS AND DRAG A
SECOND COLD FRONT INTO SOUTHERN PLAINS BY TUESDAY. MOISTURE WILL
BE PLENTIFUL ENOUGH THAT WE HAVE MAINTAINED THE LOW CHANCES FOR
SHOWERS AND STORMS UNTIL TIMING AND ENVIRONMENTAL DETAILS BECOME
CLEARER FOR THAT TIME FRAME AND WE CAN DIAGNOSE WHEN THE BEST
CHANCES WILL OCCUR. THE LATTER HALF OF NEXT WEEK WAS KEPT DRY AND
WARM FOR NOW...AS THE SECOND FRONT WASHES OUT OVER THE SOUTHERN
PART OF THE STATE. HOWEVER...LOW RAIN CHANCES MAY NEED TO BE
EXTENDED ACROSS OUR CENTRAL TEXAS COUNTIES IF THE FRONT STALLS
FURTHER NORTH. HIGH TEMPERATURES WILL MODIFY BACK TO THE MID AND
UPPER 80S WITH A FEW READINGS IN THE LOWER 90S POSSIBLE ACROSS OUR
CENTRAL TEXAS COUNTIES.
05/
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 73 75 60 77 66 / 70 70 20 10 10
WACO, TX 73 84 63 79 65 / 40 50 40 30 10
PARIS, TX 71 72 59 75 62 / 70 70 20 10 10
DENTON, TX 70 72 58 77 64 / 70 70 20 10 10
MCKINNEY, TX 70 73 58 75 63 / 70 70 20 10 10
DALLAS, TX 73 76 60 76 67 / 60 70 20 10 10
TERRELL, TX 73 79 61 76 64 / 60 70 30 10 10
CORSICANA, TX 74 83 63 79 65 / 40 50 40 20 10
TEMPLE, TX 72 88 63 78 65 / 20 60 50 30 20
MINERAL WELLS, TX 69 72 57 75 63 / 70 70 20 10 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...CORRECTED
NWS FORT WORTH TX
639 PM CDT THU SEP 11 2014
.AVIATION...
TSRA DECREASING WITH LOSS OF HEATING...BUT WARM ADVECTION PATTERN
WILL SET UP LATER THIS EVENING AND STORMS WILL INCREASE AGAIN
NORTH OF THE FRONT. THIS ALREADY APPEARS TO BE THE CASE FROM THE
LOWER PECOS VALLEY TO HILL COUNTRY. STORMS ARE EXPECTED TO EXPAND
INTO THE DFW METROPLEX LATE TONIGHT...AND HAVE KEPT THE 10Z-14Z
TIME FRAME FOR TSRA IN THE TAF. COVERAGE WILL BE SCATTERED SO HAVE
KEPT VCTS FOR NOW. THERE IS POTENTIAL FOR SOME HEAVY RAIN SO IF
ONE OF THOSE CELLS MOVES OVER AN AIRPORT EXPECT IFR VISIBILITIES
IN PRECIPITATION.
WACO APPEARS TO BE TOO FAR SOUTH FOR THE WARM ADVECTION STORMS
TONIGHT...BUT THEY SHOULD DEVELOP MVFR CEILINGS OVERNIGHT AND
WILL LIKELY REMAIN MVFR FOR MOST OF THE DAY TOMORROW. THERE MAY BE
A TSRA CHANCE FOR FRIDAY AFTERNOON AT WACO...WILL SEE WHAT THE 00Z
MODELS HAVE TO SAY AND PUT TSRA IN WITH 06Z TAFS IF IT IS NEEDED. 84
&&
.PREV DISCUSSION... /ISSUED 321 PM CDT THU SEP 11 2014/
PLENTY OF CHALLENGES THIS FORECAST PACKAGE AS WE TRACK A SLOW-
MOVING FRONT NOW EXTENDING FROM A GATESVILLE...TO CORSICANA...TO
CANTON LINE. A BROKEN LINE OF SHOWERS AND THUNDERSTORMS CONTAINING
LOCALLY HEAVY RAINFALL HAS ERUPTED IN THE PAST 1-2 HOURS ALONG THE
BOUNDARY. IN ADDITION...LOCALIZED FLOODING ISSUES WILL NEED TO BE
MONITORED ALONG THE COLD FRONT WITH THIS BROKEN LINE OF STORMS
WITH RICH PRECIPITABLE WATER VALUES WELL ABOVE 2 INCHES AND HIGH
THETA-E AIR BETWEEN 700-850MB. ANY TRAINING ACTIVITY WILL LIKELY
CAUSE SOME LOCALIZED HYDROLOGIC PROBLEMS. WE WILL CARRY THE HIGHEST
RAIN CHANCES THIS EVENING ALONG AND AHEAD OF THE FRONT OR ACROSS
THE SOUTHEAST HALF OF THE REGION. THE BEST INSTABILITY AND FORCING
WITH THE COLD FRONT WILL MOST LIKELY DRIVE THIS ACTIVITY THROUGH
NIGHTFALL. IN ADDITION...WE HAVE ADDED HIGHER CHANCES ACROSS THE
FAR WESTERN COUNTIES FOR LATE EVENING. THE APPROACH OF A SUBTLE
DISTURBANCE OVER WEST TEXAS WILL LIKELY PROVIDE ENOUGH LIFT TO
SUSTAIN A FEW SHOWER OR STORMS ACROSS THE FAR WESTERN COUNTIES
AFTER SUNSET.
THE WEST TEXAS DISTURBANCE WILL CONTINUE TO MOVE OVER THE RED RIVER
AREA AND SOUTHERN OKLAHOMA TONIGHT. NORTHERN AREAS...ESPECIALLY
THOSE ALONG AND NORTH OF I-20 WILL BE UNDERNEATH THE RIGHT ENTRANCE
REGION OF A 60-70KT JET STREAK STREAMING OVER OKLAHOMA. AS WE HEAD
INTO FRIDAY MORNING...A STRONGER DISTURBANCE CURRENTLY OVER WYOMING
WILL ROTATE SOUTHEAST OVER THE KANSAS/NEBRASKA BORDER AND SHOULD
SHUNT THE JET STREAK A LITTLE FURTHER SOUTH. THE COMBINATION OF
THESE FEATURES WILL PROVIDE THE SYNOPTIC LIFT...WHILE NOCTURNAL
LOW LEVEL WARM ADVECTION OVERRIDES THE SHALLOW FRONTAL INVERSION.
WITH THE FOCUS SHIFTING BACK NORTH...WILL MAINTAIN LIKELY CHANCES
FOR RAINFALL WHICH AT TIMES COULD BE LOCALLY HEAVY...BUT NOT ENOUGH
ALONG WITH ANTECEDENT DRY SOIL CONDITIONS TO ISSUE ANY FLOOD WATCHES
AT THIS POINT. 500-700MB LAPSE RATES WILL BE HOVERING AROUND 6 DEG/KM
WITH BOTH RUC AND NAM12 BUFKIT SOUNDINGS INDICATING A DEEP...BUT
SKINNY LAYER OF CAPE. ALL TOLD...SHOWERS WILL BE LIKELY OVERNIGHT
TONIGHT INTO FRIDAY MORNING ACROSS THESE AREAS WITH EMBEDDED/ELEVATED
THUNDERSTORMS AT TIMES. RAIN CHANCES AFTER NIGHTFALL ACROSS CENTRAL
TEXAS SHOULD DIMINISH TO LOWER CHANCES THAN WHAT WILL BE SEEN
ACROSS THE NORTH. THERE WILL BE QUITE A VARIANCE ON HIGH TEMPERATURES
FROM NORTHWEST TO SOUTHEAST FRIDAY. HIGHS WILL ONLY PUSH TO AROUND
70 DEGREES ACROSS THE FAR NORTHWEST... TO THE LOWER 90S ACROSS THE
FAR SOUTHEAST.
BETTER RAIN CHANCES SHIFT BACK OVER CENTRAL TEXAS ONCE AGAIN
FRIDAY AFTERNOON INTO SATURDAY MORNING. THE PASSAGE OF THE STRONG
SHORTWAVE TO THE NORTH TOWARD NORTHERN MISSOURI AND IOWA WILL HELP
SEND A STRONGER AND DEEPER PUSH OF COOLER AIR INTO THE NORTHERN
COUNTIES WITH THE SOUTH REMAINING WARMER AND MORE UNSTABLE. THE
UPPER HIGH WILL STRENGTHEN SOME BACK OVER THE AREA THIS WEEKEND
WITH JUST LINGERING LOW RAIN CHANCES ACROSS CENTRAL TEXAS WHERE
DEEPER MOISTURE WILL LINGER. THESE CHANCES SHOULD END BY NIGHTFALL
SATURDAY EVENING AS THE ATMOSPHERE STABILIZES. EVEN SO...CLOUD
COVER ON AND ABOVE THE DEEPENING FRONTAL INVERSION WILL MAINTAIN
CONSIDERABLE CLOUDINESS ACROSS THE REGION. THE CLOUDS COMBINED
WITH THE COOLER AIRMASS WILL HOLD HIGHS BETWEEN 75 AND 85 DEGREES
SATURDAY THAT WILL SLOWLY MODIFY TO THE 80S ON SUNDAY.
THE FORECAST AFTER THE WEEKEND BECOMES CHALLENGING ONCE AGAIN AS
WE MONITOR AN UPPER DISTURBANCE ROTATING AROUND THE WESTERN PERIPHERY
OF THE UPPER HIGH OVER THE WESTERN GULF COAST ON MONDAY. BY MONDAY
NIGHT AND TUESDAY...ANOTHER STRONG DISTURBANCE WILL MOVE DOWN
WITHIN NORTHWEST FLOW ALOFT ACROSS THE CENTRAL PLAINS AND DRAG A
SECOND COLD FRONT INTO SOUTHERN PLAINS BY TUESDAY. MOISTURE WILL
BE PLENTIFUL ENOUGH THAT WE HAVE MAINTAINED THE LOW CHANCES FOR
SHOWERS AND STORMS UNTIL TIMING AND ENVIRONMENTAL DETAILS BECOME
CLEARER FOR THAT TIME FRAME AND WE CAN DIAGNOSE WHEN THE BEST
CHANCES WILL OCCUR. THE LATTER HALF OF NEXT WEEK WAS KEPT DRY AND
WARM FOR NOW...AS THE SECOND FRONT WASHES OUT OVER THE SOUTHERN
PART OF THE STATE. HOWEVER...LOW RAIN CHANCES MAY NEED TO BE
EXTENDED ACROSS OUR CENTRAL TEXAS COUNTIES IF THE FRONT STALLS
FURTHER NORTH. HIGH TEMPERATURES WILL MODIFY BACK TO THE MID AND
UPPER 80S WITH A FEW READINGS IN THE LOWER 90S POSSIBLE ACROSS OUR
CENTRAL TEXAS COUNTIES.
05/
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 73 75 62 77 66 / 70 70 20 10 10
WACO, TX 73 84 65 79 65 / 40 50 40 30 10
PARIS, TX 71 73 60 75 62 / 70 70 20 10 10
DENTON, TX 70 72 61 77 64 / 70 70 20 10 10
MCKINNEY, TX 70 72 59 75 63 / 70 70 20 10 10
DALLAS, TX 73 76 62 76 67 / 60 70 20 10 10
TERRELL, TX 73 79 63 76 64 / 60 70 30 10 10
CORSICANA, TX 74 83 65 79 65 / 50 50 40 20 10
TEMPLE, TX 72 86 65 78 65 / 30 60 50 30 20
MINERAL WELLS, TX 69 72 59 75 63 / 70 70 20 10 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
638 PM CDT THU SEP 11 2014
.AVIATION...
TSRA DECREASING WITH LOSS OF HEATING...BUT WARM ADVECTION PATTERN
WILL SET UP LATER THIS EVENING AND STORMS WILL INCREASE AGAIN
NORTH OF THE FRONT. THIS ALREADY APPEARS TO BE THE CASE FROM THE
LOWER PECOS VALLEY TO HILL COUNTRY. STORMS ARE EXPECTED TO EXPAND
INTO THE DFW METROPLEX LATE TONIGHT...AND HAVE KEPT THE 10Z-14Z
TIME FRAME FOR TSRA IN THE TAF. COVERAGE WILL BE SCATTERED SO HAVE
KEPT VCTS FOR NOW. THERE IS POTENTIAL FOR SOME HEAVY RAIN SO IF
ONE OF THOSE CELLS MOVES OVER AN AIRPORT EXPECT IFR VISIBILITIES
IN PRECIPITATION.
WACO APPEARS TO BE TOO FAR SOUTH FOR THE WARM ADVECTION STORMS
TONIGHT...BUT THEY SHOULD DEVELOP MVFR CEILINGS OVERNIGHT AND
WILL LIKELY REMAIN MVFR FOR MOST OF THE DAY TOMORROW. THERE MAY BE
A TSRA CHANCE FOR FRIDAY AFTERNOON AT WACO...WILL SEE WHAT THE 00Z
MODELS HAVE TO SAY AND PUT TSRA IN BY 06 IF IT IS NEEDED. 84
&&
.PREV DISCUSSION... /ISSUED 321 PM CDT THU SEP 11 2014/
PLENTY OF CHALLENGES THIS FORECAST PACKAGE AS WE TRACK A SLOW-
MOVING FRONT NOW EXTENDING FROM A GATESVILLE...TO CORSICANA...TO
CANTON LINE. A BROKEN LINE OF SHOWERS AND THUNDERSTORMS CONTAINING
LOCALLY HEAVY RAINFALL HAS ERUPTED IN THE PAST 1-2 HOURS ALONG THE
BOUNDARY. IN ADDITION...LOCALIZED FLOODING ISSUES WILL NEED TO BE
MONITORED ALONG THE COLD FRONT WITH THIS BROKEN LINE OF STORMS
WITH RICH PRECIPITABLE WATER VALUES WELL ABOVE 2 INCHES AND HIGH
THETA-E AIR BETWEEN 700-850MB. ANY TRAINING ACTIVITY WILL LIKELY
CAUSE SOME LOCALIZED HYDROLOGIC PROBLEMS. WE WILL CARRY THE HIGHEST
RAIN CHANCES THIS EVENING ALONG AND AHEAD OF THE FRONT OR ACROSS
THE SOUTHEAST HALF OF THE REGION. THE BEST INSTABILITY AND FORCING
WITH THE COLD FRONT WILL MOST LIKELY DRIVE THIS ACTIVITY THROUGH
NIGHTFALL. IN ADDITION...WE HAVE ADDED HIGHER CHANCES ACROSS THE
FAR WESTERN COUNTIES FOR LATE EVENING. THE APPROACH OF A SUBTLE
DISTURBANCE OVER WEST TEXAS WILL LIKELY PROVIDE ENOUGH LIFT TO
SUSTAIN A FEW SHOWER OR STORMS ACROSS THE FAR WESTERN COUNTIES
AFTER SUNSET.
THE WEST TEXAS DISTURBANCE WILL CONTINUE TO MOVE OVER THE RED RIVER
AREA AND SOUTHERN OKLAHOMA TONIGHT. NORTHERN AREAS...ESPECIALLY
THOSE ALONG AND NORTH OF I-20 WILL BE UNDERNEATH THE RIGHT ENTRANCE
REGION OF A 60-70KT JET STREAK STREAMING OVER OKLAHOMA. AS WE HEAD
INTO FRIDAY MORNING...A STRONGER DISTURBANCE CURRENTLY OVER WYOMING
WILL ROTATE SOUTHEAST OVER THE KANSAS/NEBRASKA BORDER AND SHOULD
SHUNT THE JET STREAK A LITTLE FURTHER SOUTH. THE COMBINATION OF
THESE FEATURES WILL PROVIDE THE SYNOPTIC LIFT...WHILE NOCTURNAL
LOW LEVEL WARM ADVECTION OVERRIDES THE SHALLOW FRONTAL INVERSION.
WITH THE FOCUS SHIFTING BACK NORTH...WILL MAINTAIN LIKELY CHANCES
FOR RAINFALL WHICH AT TIMES COULD BE LOCALLY HEAVY...BUT NOT ENOUGH
ALONG WITH ANTECEDENT DRY SOIL CONDITIONS TO ISSUE ANY FLOOD WATCHES
AT THIS POINT. 500-700MB LAPSE RATES WILL BE HOVERING AROUND 6 DEG/KM
WITH BOTH RUC AND NAM12 BUFKIT SOUNDINGS INDICATING A DEEP...BUT
SKINNY LAYER OF CAPE. ALL TOLD...SHOWERS WILL BE LIKELY OVERNIGHT
TONIGHT INTO FRIDAY MORNING ACROSS THESE AREAS WITH EMBEDDED/ELEVATED
THUNDERSTORMS AT TIMES. RAIN CHANCES AFTER NIGHTFALL ACROSS CENTRAL
TEXAS SHOULD DIMINISH TO LOWER CHANCES THAN WHAT WILL BE SEEN
ACROSS THE NORTH. THERE WILL BE QUITE A VARIANCE ON HIGH TEMPERATURES
FROM NORTHWEST TO SOUTHEAST FRIDAY. HIGHS WILL ONLY PUSH TO AROUND
70 DEGREES ACROSS THE FAR NORTHWEST... TO THE LOWER 90S ACROSS THE
FAR SOUTHEAST.
BETTER RAIN CHANCES SHIFT BACK OVER CENTRAL TEXAS ONCE AGAIN
FRIDAY AFTERNOON INTO SATURDAY MORNING. THE PASSAGE OF THE STRONG
SHORTWAVE TO THE NORTH TOWARD NORTHERN MISSOURI AND IOWA WILL HELP
SEND A STRONGER AND DEEPER PUSH OF COOLER AIR INTO THE NORTHERN
COUNTIES WITH THE SOUTH REMAINING WARMER AND MORE UNSTABLE. THE
UPPER HIGH WILL STRENGTHEN SOME BACK OVER THE AREA THIS WEEKEND
WITH JUST LINGERING LOW RAIN CHANCES ACROSS CENTRAL TEXAS WHERE
DEEPER MOISTURE WILL LINGER. THESE CHANCES SHOULD END BY NIGHTFALL
SATURDAY EVENING AS THE ATMOSPHERE STABILIZES. EVEN SO...CLOUD
COVER ON AND ABOVE THE DEEPENING FRONTAL INVERSION WILL MAINTAIN
CONSIDERABLE CLOUDINESS ACROSS THE REGION. THE CLOUDS COMBINED
WITH THE COOLER AIRMASS WILL HOLD HIGHS BETWEEN 75 AND 85 DEGREES
SATURDAY THAT WILL SLOWLY MODIFY TO THE 80S ON SUNDAY.
THE FORECAST AFTER THE WEEKEND BECOMES CHALLENGING ONCE AGAIN AS
WE MONITOR AN UPPER DISTURBANCE ROTATING AROUND THE WESTERN PERIPHERY
OF THE UPPER HIGH OVER THE WESTERN GULF COAST ON MONDAY. BY MONDAY
NIGHT AND TUESDAY...ANOTHER STRONG DISTURBANCE WILL MOVE DOWN
WITHIN NORTHWEST FLOW ALOFT ACROSS THE CENTRAL PLAINS AND DRAG A
SECOND COLD FRONT INTO SOUTHERN PLAINS BY TUESDAY. MOISTURE WILL
BE PLENTIFUL ENOUGH THAT WE HAVE MAINTAINED THE LOW CHANCES FOR
SHOWERS AND STORMS UNTIL TIMING AND ENVIRONMENTAL DETAILS BECOME
CLEARER FOR THAT TIME FRAME AND WE CAN DIAGNOSE WHEN THE BEST
CHANCES WILL OCCUR. THE LATTER HALF OF NEXT WEEK WAS KEPT DRY AND
WARM FOR NOW...AS THE SECOND FRONT WASHES OUT OVER THE SOUTHERN
PART OF THE STATE. HOWEVER...LOW RAIN CHANCES MAY NEED TO BE
EXTENDED ACROSS OUR CENTRAL TEXAS COUNTIES IF THE FRONT STALLS
FURTHER NORTH. HIGH TEMPERATURES WILL MODIFY BACK TO THE MID AND
UPPER 80S WITH A FEW READINGS IN THE LOWER 90S POSSIBLE ACROSS OUR
CENTRAL TEXAS COUNTIES.
05/
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 73 75 62 77 66 / 70 70 20 10 10
WACO, TX 73 84 65 79 65 / 40 50 40 30 10
PARIS, TX 71 73 60 75 62 / 70 70 20 10 10
DENTON, TX 70 72 61 77 64 / 70 70 20 10 10
MCKINNEY, TX 70 72 59 75 63 / 70 70 20 10 10
DALLAS, TX 73 76 62 76 67 / 60 70 20 10 10
TERRELL, TX 73 79 63 76 64 / 60 70 30 10 10
CORSICANA, TX 74 83 65 79 65 / 50 50 40 20 10
TEMPLE, TX 72 86 65 78 65 / 30 60 50 30 20
MINERAL WELLS, TX 69 72 59 75 63 / 70 70 20 10 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
113 PM EDT WED SEP 10 2014
.SYNOPSIS...
LOW PRESSURE PASSING WELL TO THE NORTH WILL DRAG A TRAILING COLD
FRONT TOWARD THE REGION TONIGHT...REACHING THE WESTERN SLOPES OF
THE APPALACHIANS BY LATER THURSDAY. THE FRONT IS EXPECTED TO
STALL OVER THE CAROLINAS FRIDAY AND THEN MEANDER JUST SOUTH OF
THE AREA OVER THE WEEKEND. WEAK LOW PRESSURE RIDING ALONG THE
BOUNDARY MAY KEEP PERIODS OF SHOWERS GOING INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1113 AM EDT WEDNESDAY...
UPDATING TO LOWER TEMPS A BIT AND HOLD CLOUDS LONGER ESPCLY ALONG
THE BLUE RIDGE WHERE LOW CLOUDS REMAIN PERSISTENT WITH EVEN SOME
SPOTTY -RA MIXED IN GIVEN THE WEAK LOW LEVEL VEERING PROFILE OFF
MORNING RAOBS. ALSO WITH SO MUCH LINGERING MOISTURE STUCK BENEATH
MULTIPLE INVERSIONS ALOFT OFF 12Z SOUNDINGS APPEARS WILL BE TOUGH
TO GET A QUICK EROSION OF THE CANOPY WITHOUT IT FILLING BACK IN
ESPCLY EARLY ON. EXPECT ONCE THE FLOW TURNS MORE SOUTH/SW LATER ON
AND MIXING INCREASES WILL SEE SOME DRIER AIR ALOFT MIX DOWN BUT
MAY BE LATE BEFORE THE EASTERN SLOPES OF THE BLUE RIDGE SEE A LOT
OF SUN. TEMPS LIKELY TO JUMP WHERE DO GET SOME SUSTAINED BREAKS
BUT FOR NOW BASED ON LATEST TRENDS AND LAV MOS...THINK HIGHS MAY
REMAIN IN THE 70S EXCEPT FOR THE FAR EAST/SE AND WESTERN PERIMETER
COUNTIES. ISOLATED WESTERN POPS THIS AFTERNOON STILL APPEAR OK
WITH THE BRIEF SHOTGUN PATTERN SUGGESTED BY THE LATEST HRRR BUT
THIS BASED ON SOME INSTABILITY PER HEATING WHICH MAY ONLY OCCUR
ALONG THE I-77 CORRIDOR AT THIS POINT.
PREVIOUS UPDATE AS OF 925 AM EDT WEDNESDAY...
ADDED SLIGHT CHANCE POPS ALONG THE BLUE RIDGE UP TO ROANOKE AS
SURFACE OBS AND WEATHER SPOTTERS HAVE CONFIRMED SOME LIGHT DRIZZLE
THIS MORNING. TWEAKED THE SKY GRIDS OUT WEST WHERE THERE HAS BEEN
SOME CLEARING. ALSO ADJUSTED THE NEAR TERM TEMPS. ALL OTHER
FORECAST DETAILS FROM THE PREVIOUS DISCUSSION REMAIN ON TRACK.
PREVIOUS DISCUSSION AS OF 430 AM EDT WEDNESDAY...
STARTING OFF WITH LOTS OF CLOUD COVER THIS MORNING...COURTESY OF
LINGERING MOISTURE BANKED UP AGAINST THE EAST SIDE OF THE
MOUNTAINS. THE EASTERLY WIND WHICH HAS BEEN KEEPING THE CLOUDS
PINNED ACROSS THE AREA WILL WEAKEN TODAY AS FLOW BEGINS TO TREND
MORE SOUTHERLY PER APPROACH OF FRONTAL SYSTEM OVER THE MIDDLE PART
OF THE COUNTRY.
AS OF 4AM...CYCLOGENESIS WAS TAKING PLACE OVER THE MIDDLE PART OF
THE COUNTRY WITH LOW PRESSURE DEVELOPING NEAR TOPEKA KANSAS. THIS
AREA OF LOW PRESSURE IS FORECAST TO STRENGTHEN TODAY PER STRONG
DYNAMICS ALOFT ASSOCIATED WITH A SHORT WAVE TROUGH EXITING THE
ROCKIES. THE DEEPENING LOW...10 MB PRESSURE FALL OVER THE NXT 12
HOURS...IS PROGGED TO MOVE NORTHEAST INTO THE GREAT LAKES...THE
TRAILING COLD FRONT SLICING SOUTH THROUGH MISSOURI-TEXAS. AHEAD OF
THE FRONT...WINDS WILL BE SOUTHWESTERLY THROUGH THE TENNESSEE AND
OHIO VALLEYS...WARM AIR ADVECTION TAKING PLACE UPSTREAM OF OUR
FORECAST AREA...AND EVENTUALLY INCLUDING OUR FORECAST AREA LATER
TODAY AND TONIGHT.
AS WARM AIR ADVECTION INCREASES FROM THE SOUTHWEST LATER
TODAY...EXPECT CLOUD COVER CURRENTLY OVER OUR FORECAST AREA TO MIX
OUT WITH INCREASING AMOUNTS OF SUN. SUNNY BREAKS WILL LIKELY BEGIN
IN THE WESTERN PART OF THE CWA FIRST...THEN SPREAD EAST. MORE SUN
MEANS WARMER TEMPERATURES...MODEL MOS SUGGESTING WE TEST 80 TODAY
WITH A TEMPERATURE RANGE OF 76 TO 83. MILD TEMPERATURES ARE LIKELY
TONIGHT...SOUTHWEST WINDS CONTINUING TO PROMOTE WARM AIR
ADVECTION...LOWS IN THE 60S.
NOT MUCH THREAT FOR PRECIP TODAY OR TONIGHT. MODEL SOUNDINGS
INDICATE CAPE VALUES POTENTIALLY REACHING 500 J/KG IN THE
MOUNTAINS TODAY. THIS MAY SUPPORT AN ISOLATED SHOWER OR TWO...BUT
NOT MUCH MORE THAN THAT. BETTER CHANCE FOR PRECIP WILL COME WITH
THE FRONTAL PASSAGE LATER THURSDAY.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 400 AM EDT WEDNESDAY...
LOOK FOR THURSDAY TO BE THE WARMEST DAY OF THE WEEK AS DEEP
SOUTHWESTERLY FLOW BECOMES ESTABLISHED AHEAD OF A STRONG COLD FRONT
APPROACHING FROM THE GREAT LAKES REGION. THE SOUTHWESTERLY WINDS
WILL DRAW VERY WARM GULF MOISTURE NORTHWARD ALONG THE APPALACHIAN
CHAIN...WHICH WILL HELP AFTERNOON HIGHS CLIMB INTO THE UPPER 70S/LOW
80S ACROSS THE MOUNTAINS...WHILE THE PIEDMONT WILL REACH INTO THE
MID 80S TO AROUND 90 IN THE SOUTHSIDE. RAIN CHANCES WILL INCREASE
DRASTICALLY DURING THE AFTERNOON AS THE FRONT CROSSES THE OHIO
RIVER...WITH SHOWERS AND THUNDERSTORMS BECOMING WIDESPREAD ACROSS
MOST OF THE AREA BY SUNSET.
STORM PREDICTION CENTER HAS MUCH OF OUR FORECAST REGION UNDER A
SLIGHT CHANCE FOR SEVERE THUNDERSTORMS...SO WILL BE ON THE LOOKOUT
FOR A FEW STORMS PACKING GUSTY WINDS DURING THE EVENING...MAINLY
NORTH OF HIGHWAY 460...AS THE STRONGER DOWNDRAFTS TRY TO PULL THE
25KT-30KT 850MB WINDS DOWN TO THE SURFACE. BELIEVE THERE WILL ALSO
BE A CHANCE FOR LOCALLY HEAVY RAIN ACROSS THE MOUNTAINS AS GULF
MOISTURE POOLING AHEAD OF THE FRONT PUSHES PRECIPITABLE WATER IN THE
BALLPARK OF 2 INCHES.
THE COLD FRONT WILL CONTINUE ITS SOUTHWARD PUSH THURSDAY NIGHT...
BEFORE STALLING ACROSS CENTRAL NORTH CAROLINA JUST SOUTH OF OUR AREA
ON FRIDAY AS IT RUNS INTO UPPER LEVEL RIDGING ACROSS THE SOUTHEAST
STATES. MODELS ARE COMING INTO BETTER AGREEMENT THAT...DESPITE THE
FRONTAL PASSAGE...DEWPOINTS DO NOT DROP OFF ALL THAT MUCH FOR OUR
AREA. AS SUCH...EXPECT THAT THERE WILL BE ENOUGH LOW LEVEL MOISTURE
LEFT OVER TO SUPPORT SCATTERED SHOWER ACTIVITY ACROSS THE MOUNTAINS
AND THE PIEDMONT SOUTH OF HIGHWAY 460 THROUGH THE AFTERNOON AND
EVENING. DRIER HIGH PRESSURE WILL BE WEDGING SOUTHWARD ACROSS THE
PIEDMONT FURTHER NORTH. HIGHS FOR FRIDAY WILL BE COOLER...MAINLY IN
THE 70S MOST LOCATIONS.
SHOWER ACTIVITY WILL INCREASE AGAIN ON SATURDAY AS A WAVE OF LOW
PRESSURE DEVELOPS ALONG THE FRONT. SURFACE HIGH PRESSURE BANKED
AGAINST THE EASTERN FACE OF THE APPALACHIANS WILL PROVIDE ENOUGH
STABILITY TO LIMIT RAINFALL TO SHOWER ACTIVITY FOR MOST OF THE
AREA...ALTHOUGH AN ISOLATED THUNDERSTORM MAY DEVELOP ACROSS THE
MOUNTAIN EMPIRE...AN AREA REMOVED FROM THE INFLUENCE OF THE HIGH. AT
ANY RATE...THE WAVE WILL SHIFT RAPIDLY TO THE NORTH ON SATURDAY...
DRAGGING A SECONDARY COLD FRONT ACROSS OUR AREA DURING THE EVENING.
CANADIAN HIGH PRESSURE BUILDING IN BEHIND THE COLD FRONT WILL BE THE
COOLEST AIR WE HAVE SEEN IN SEVERAL MONTHS...A DEFINITE SIGNAL
THAT AUTUMN IS NOT TOO FAR INTO THE FUTURE.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 100 PM EDT TUESDAY...
FORECAST REMAINS RATHER LOW CONFIDENCE FOR SUNDAY INTO TUESDAY GIVEN
WEST/SW FLOW ALOFT BETWEEN AN UPPER TROUGH TO THE NW AND THE
RESIDUAL AXIS OF DEEPER MOISTURE ALONG THE COAST. LATEST GUIDANCE
STILL RATHER MIXED ON DEGREE OF MOISTURE GETTING PULLED BACK
INLAND/NORTH AHEAD OF THE MAIN TROUGH AS APPEARS SOME SORT OF
LEFTOVER DEFORMATION AXIS MAY LINGER WITH THE COASTAL LOW. THUS KEPT
SOME LOW POPS IN SOUTH/EAST ESPCLY SUNDAY/SUNDAY NIGHT THEN
DECREASING MONDAY FOR NOW. APPEARS DRIER AIR WITH THE STRONGER
SURFACE HIGH BUILDING IN FROM THE NW WILL FINALLY OCCUR BY TUESDAY
BUT EVEN THEN CLOUDS/SHOWERS MAY LINGER/RETURN WITH YET ANOTHER WAVE
PASSING. TEMPS TO COOL BELOW NORMAL THROUGH THE PERIOD WITH MAINLY
60S MOUNTAINS AND LOW 70S EAST FOR HIGHS...AND 50S WEST 60S PIEDMONT
FOR LOWS PENDING CLOUD COVER WHICH COULD MAKE HIGHS EVEN COOLER.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 1255 PM EDT WEDNESDAY...
STUBBORN LOW LEVEL CLOUDS REMAIN SLOW TO ERODE EARLY THIS
AFTERNOON WITH MOSTLY MVFR CIGS IN PLACE. STILL EXPECTING A
GRADUAL IMPROVEMENT TO VFR BASES AS WELL AS A REDUCTION IN CLOUD
COVER THROUGH THE REST OF THE AFTERNOON/EVENING AS WINDS BECOME
MORE SOUTHERLY. HOWEVER MAY STILL TAKE UNTIL LATE IN THE DAY FOR
LOWER CIGS AT KBCB/KROA TO LIFT INTO VFR RANGE.
A STRONG LOW PRESSURE SYSTEM PASSING WELL TO THE NORTH WILL PROPEL
A TRAILING COLD FRONT TOWARD THE AREA LATE TONIGHT INTO THURSDAY.
PRE-FRONTAL SHOWERS/STORMS AHEAD OF THE FRONT MAY APPROACH THE FAR
NORTHWESTERN LOCATIONS EARLY THURSDAY WITH INCREASING COVERAGE
FROM NW TO SE DURING THE DAY. AS DEEPER MOISTURE RETURNS LATER
TONIGHT...LIKELY TO SEE SOME LOW CLOUDS RETURN WEST WHILE LIGHT
WINDS MAY PROMOTE RETURN OF THE RESIDUAL WEDGE AND LOW CLOUDS BLUE
RIDGE LATE TONIGHT. WONT GO QUITE AS PESSIMISTIC AS MOST GUIDANCE
GIVEN WEAK SOUTHERLY FLOW BUT INCLUDING SOME MVFR CIGS FROM THE
BLUE RIDGE EAST ALONG WITH BRIEF DENSE FOG THAT MAY BRING PERIODS
OF MVFR/IFR BY DAYBREAK THURSDAY.
ANY LOW CLOUDS/FOG SHOULD FINALLY MIX OUT WITH INCREASING SW FLOW
THURSDAY MORNING OVER THE EAST...WHILE CIGS LOWER OVER THE WEST
WITH LEFTOVER EARLIER SHRA PERHAPS REACHING KLWB/KBLF LATE
MORNING/EARLY AFTERNOON THURSDAY. HOWEVER APPEARS BEST SHOT AT
SEEING BANDS/CLUSTERS OF CONVECTION WONT OCCUR UNTIL MID/LATE
AFTERNOON THURSDAY AND BEYOND THE TIME OF THE VALID TAF PERIOD.
WEST/SW WINDS SHOULD TURN A BIT GUSTY AS WELL AHEAD OF THE FRONT
THURSDAY AFTERNOON WITH 10-20 KTS LIKELY AND STRONGER CLOSER TO
ANY STORMS.
EXTENDED DISCUSSION...
FROPA IS EXPECTED THURSDAY NIGHT. THIS FRONTAL PASSAGE WILL NOT
BE A CLEAN SWEEP OF AIRMASSES...THE MAJORITY OF THE MODELS
INDICATING THE FRONT WILL STALL OVER THE CAROLINAS
FRIDAY...FOLLOWED BY DEVELOPMENT OF LOW PRESSURE ALONG THE FRONT
FRIDAY NIGHT...TRACKING NORTHEAST THROUGH THE REGION SATURDAY.
STILL APPEARS THAT AN EXTENDED PERIOD OF MVFR...POSSIBLY
IFR...WILL EXIST FRIDAY NIGHT INTO SATURDAY. LOW CONFIDENCE
FORECAST FOR SUNDAY WITH MODELS SHOWING LOW LEVEL MOISTURE
LINGERING ALONG WITH SPOTTY SHOWERS AS COMPLEX LOW PRESSURE
DEVELOPS OVER THE REGION SO APPEARS OVERALL MVRF TO PERSIST INTO
SUNDAY NIGHT AT THIS POINT. LOW CLOUDS MAY ERODE ON MONDAY BUT
WITH LEFTOVER MOISTURE EXPECTING POTENTIAL FOR MVFR AT TIMES IN
SPOTTY SHOWERS MONDAY AFTERNOON. OTRW SLOW IMPROVEMENT TO VFR FOR
EARLY NEXT WEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...CF/JH/PM
SHORT TERM...NF
LONG TERM...JH
AVIATION...JH/PM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1122 AM EDT WED SEP 10 2014
.SYNOPSIS...
LOW PRESSURE OVER THE MIDDLE PART OF THE COUNTRY WILL STRENGTHEN
AS IT MOVES INTO THE GREAT LAKES TODAY. THE TRAILING COLD FRONT
WILL MOVE EAST INTO THE OHIO AND TENNESSEE VALLEYS TONIGHT AND
THURSDAY...THEN CROSS THE MOUNTAINS THURSDAY NIGHT. THE FRONT IS
EXPECTED TO STALL OVER THE CAROLINAS FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1113 AM EDT WEDNESDAY...
UPDATING TO LOWER TEMPS A BIT AND HOLD CLOUDS LONGER ESPCLY ALONG
THE BLUE RIDGE WHERE LOW CLOUDS REMAIN PERSISTENT WITH EVEN SOME
SPOTTY -RA MIXED IN GIVEN THE WEAK LOW LEVEL VEERING PROFILE OFF
MORNING RAOBS. ALSO WITH SO MUCH LINGERING MOISTURE STUCK BENEATH
MULTIPLE INVERSIONS ALOFT OFF 12Z SOUNDINGS APPEARS WILL BE TOUGH
TO GET A QUICK EROSION OF THE CANOPY WITHOUT IT FILLING BACK IN
ESPCLY EARLY ON. EXPECT ONCE THE FLOW TURNS MORE SOUTH/SW LATER ON
AND MIXING INCREASES WILL SEE SOME DRIER AIR ALOFT MIX DOWN BUT
MAY BE LATE BEFORE THE EASTERN SLOPES OF THE BLUE RIDGE SEE A LOT
OF SUN. TEMPS LIKELY TO JUMP WHERE DO GET SOME SUSTAINED BREAKS
BUT FOR NOW BASED ON LATEST TRENDS AND LAV MOS...THINK HIGHS MAY
REMAIN IN THE 70S EXCEPT FOR THE FAR EAST/SE AND WESTERN PERIMETER
COUNTIES. ISOLATED WESTERN POPS THIS AFTERNOON STILL APPEAR OK
WITH THE BRIEF SHOTGUN PATTERN SUGGESTED BY THE LATEST HRRR BUT
THIS BASED ON SOME INSTABILITY PER HEATING WHICH MAY ONLY OCCUR
ALONG THE I-77 CORRIDOR AT THIS POINT.
PREVIOUS UPDATE AS OF 925 AM EDT WEDNESDAY...
ADDED SLIGHT CHANCE POPS ALONG THE BLUE RIDGE UP TO ROANOKE AS
SURFACE OBS AND WEATHER SPOTTERS HAVE CONFIRMED SOME LIGHT DRIZZLE
THIS MORNING. TWEAKED THE SKY GRIDS OUT WEST WHERE THERE HAS BEEN
SOME CLEARING. ALSO ADJUSTED THE NEAR TERM TEMPS. ALL OTHER
FORECAST DETAILS FROM THE PREVIOUS DISCUSSION REMAIN ON TRACK.
PREVIOUS DISCUSSION AS OF 430 AM EDT WEDNESDAY...
STARTING OFF WITH LOTS OF CLOUD COVER THIS MORNING...COURTESY OF
LINGERING MOISTURE BANKED UP AGAINST THE EAST SIDE OF THE
MOUNTAINS. THE EASTERLY WIND WHICH HAS BEEN KEEPING THE CLOUDS
PINNED ACROSS THE AREA WILL WEAKEN TODAY AS FLOW BEGINS TO TREND
MORE SOUTHERLY PER APPROACH OF FRONTAL SYSTEM OVER THE MIDDLE PART
OF THE COUNTRY.
AS OF 4AM...CYCLOGENESIS WAS TAKING PLACE OVER THE MIDDLE PART OF
THE COUNTRY WITH LOW PRESSURE DEVELOPING NEAR TOPEKA KANSAS. THIS
AREA OF LOW PRESSURE IS FORECAST TO STRENGTHEN TODAY PER STRONG
DYNAMICS ALOFT ASSOCIATED WITH A SHORT WAVE TROUGH EXITING THE
ROCKIES. THE DEEPENING LOW...10 MB PRESSURE FALL OVER THE NXT 12
HOURS...IS PROGGED TO MOVE NORTHEAST INTO THE GREAT LAKES...THE
TRAILING COLD FRONT SLICING SOUTH THROUGH MISSOURI-TEXAS. AHEAD OF
THE FRONT...WINDS WILL BE SOUTHWESTERLY THROUGH THE TENNESSEE AND
OHIO VALLEYS...WARM AIR ADVECTION TAKING PLACE UPSTREAM OF OUR
FORECAST AREA...AND EVENTUALLY INCLUDING OUR FORECAST AREA LATER
TODAY AND TONIGHT.
AS WARM AIR ADVECTION INCREASES FROM THE SOUTHWEST LATER
TODAY...EXPECT CLOUD COVER CURRENTLY OVER OUR FORECAST AREA TO MIX
OUT WITH INCREASING AMOUNTS OF SUN. SUNNY BREAKS WILL LIKELY BEGIN
IN THE WESTERN PART OF THE CWA FIRST...THEN SPREAD EAST. MORE SUN
MEANS WARMER TEMPERATURES...MODEL MOS SUGGESTING WE TEST 80 TODAY
WITH A TEMPERATURE RANGE OF 76 TO 83. MILD TEMPERATURES ARE LIKELY
TONIGHT...SOUTHWEST WINDS CONTINUING TO PROMOTE WARM AIR
ADVECTION...LOWS IN THE 60S.
NOT MUCH THREAT FOR PRECIP TODAY OR TONIGHT. MODEL SOUNDINGS
INDICATE CAPE VALUES POTENTIALLY REACHING 500 J/KG IN THE
MOUNTAINS TODAY. THIS MAY SUPPORT AN ISOLATED SHOWER OR TWO...BUT
NOT MUCH MORE THAN THAT. BETTER CHANCE FOR PRECIP WILL COME WITH
THE FRONTAL PASSAGE LATER THURSDAY.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 400 AM EDT WEDNESDAY...
LOOK FOR THURSDAY TO BE THE WARMEST DAY OF THE WEEK AS DEEP
SOUTHWESTERLY FLOW BECOMES ESTABLISHED AHEAD OF A STRONG COLD FRONT
APPROACHING FROM THE GREAT LAKES REGION. THE SOUTHWESTERLY WINDS
WILL DRAW VERY WARM GULF MOISTURE NORTHWARD ALONG THE APPALACHIAN
CHAIN...WHICH WILL HELP AFTERNOON HIGHS CLIMB INTO THE UPPER 70S/LOW
80S ACROSS THE MOUNTAINS...WHILE THE PIEDMONT WILL REACH INTO THE
MID 80S TO AROUND 90 IN THE SOUTHSIDE. RAIN CHANCES WILL INCREASE
DRASTICALLY DURING THE AFTERNOON AS THE FRONT CROSSES THE OHIO
RIVER...WITH SHOWERS AND THUNDERSTORMS BECOMING WIDESPREAD ACROSS
MOST OF THE AREA BY SUNSET.
STORM PREDICTION CENTER HAS MUCH OF OUR FORECAST REGION UNDER A
SLIGHT CHANCE FOR SEVERE THUNDERSTORMS...SO WILL BE ON THE LOOKOUT
FOR A FEW STORMS PACKING GUSTY WINDS DURING THE EVENING...MAINLY
NORTH OF HIGHWAY 460...AS THE STRONGER DOWNDRAFTS TRY TO PULL THE
25KT-30KT 850MB WINDS DOWN TO THE SURFACE. BELIEVE THERE WILL ALSO
BE A CHANCE FOR LOCALLY HEAVY RAIN ACROSS THE MOUNTAINS AS GULF
MOISTURE POOLING AHEAD OF THE FRONT PUSHES PRECIPITABLE WATER IN THE
BALLPARK OF 2 INCHES.
THE COLD FRONT WILL CONTINUE ITS SOUTHWARD PUSH THURSDAY NIGHT...
BEFORE STALLING ACROSS CENTRAL NORTH CAROLINA JUST SOUTH OF OUR AREA
ON FRIDAY AS IT RUNS INTO UPPER LEVEL RIDGING ACROSS THE SOUTHEAST
STATES. MODELS ARE COMING INTO BETTER AGREEMENT THAT...DESPITE THE
FRONTAL PASSAGE...DEWPOINTS DO NOT DROP OFF ALL THAT MUCH FOR OUR
AREA. AS SUCH...EXPECT THAT THERE WILL BE ENOUGH LOW LEVEL MOISTURE
LEFT OVER TO SUPPORT SCATTERED SHOWER ACTIVITY ACROSS THE MOUNTAINS
AND THE PIEDMONT SOUTH OF HIGHWAY 460 THROUGH THE AFTERNOON AND
EVENING. DRIER HIGH PRESSURE WILL BE WEDGING SOUTHWARD ACROSS THE
PIEDMONT FURTHER NORTH. HIGHS FOR FRIDAY WILL BE COOLER...MAINLY IN
THE 70S MOST LOCATIONS.
SHOWER ACTIVITY WILL INCREASE AGAIN ON SATURDAY AS A WAVE OF LOW
PRESSURE DEVELOPS ALONG THE FRONT. SURFACE HIGH PRESSURE BANKED
AGAINST THE EASTERN FACE OF THE APPALACHIANS WILL PROVIDE ENOUGH
STABILITY TO LIMIT RAINFALL TO SHOWER ACTIVITY FOR MOST OF THE
AREA...ALTHOUGH AN ISOLATED THUNDERSTORM MAY DEVELOP ACROSS THE
MOUNTAIN EMPIRE...AN AREA REMOVED FROM THE INFLUENCE OF THE HIGH. AT
ANY RATE...THE WAVE WILL SHIFT RAPIDLY TO THE NORTH ON SATURDAY...
DRAGGING A SECONDARY COLD FRONT ACROSS OUR AREA DURING THE EVENING.
CANADIAN HIGH PRESSURE BUILDING IN BEHIND THE COLD FRONT WILL BE THE
COOLEST AIR WE HAVE SEEN IN SEVERAL MONTHS...A DEFINITE SIGNAL
THAT AUTUMN IS NOT TOO FAR INTO THE FUTURE.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 100 PM EDT TUESDAY...
FORECAST REMAINS RATHER LOW CONFIDENCE FOR SUNDAY INTO TUESDAY GIVEN
WEST/SW FLOW ALOFT BETWEEN AN UPPER TROUGH TO THE NW AND THE
RESIDUAL AXIS OF DEEPER MOISTURE ALONG THE COAST. LATEST GUIDANCE
STILL RATHER MIXED ON DEGREE OF MOISTURE GETTING PULLED BACK
INLAND/NORTH AHEAD OF THE MAIN TROUGH AS APPEARS SOME SORT OF
LEFTOVER DEFORMATION AXIS MAY LINGER WITH THE COASTAL LOW. THUS KEPT
SOME LOW POPS IN SOUTH/EAST ESPCLY SUNDAY/SUNDAY NIGHT THEN
DECREASING MONDAY FOR NOW. APPEARS DRIER AIR WITH THE STRONGER
SURFACE HIGH BUILDING IN FROM THE NW WILL FINALLY OCCUR BY TUESDAY
BUT EVEN THEN CLOUDS/SHOWERS MAY LINGER/RETURN WITH YET ANOTHER WAVE
PASSING. TEMPS TO COOL BELOW NORMAL THROUGH THE PERIOD WITH MAINLY
60S MOUNTAINS AND LOW 70S EAST FOR HIGHS...AND 50S WEST 60S PIEDMONT
FOR LOWS PENDING CLOUD COVER WHICH COULD MAKE HIGHS EVEN COOLER.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
AS OF 800 AM EDT WEDNESDAY...
STUBBORN LOW LEVEL CLOUDS WILL LIKELY REMAIN THROUGH THE
MORNING...MVFR CONDITIONS PERSISTING THROUGH NOON BEFORE
LIFTING INTO THE VFR CATEGORY FOR THE AFTERNOON. WINDS TODAY ARE
EXPECTED TO BECOME SOUTHERLY...PROMOTING THE BREAK UP OF THE
EXISTING CLOUD COVER WHICH HAS BEEN BANKED UP AGAINST THE EAST
SIDE OF THE APPALACHIANS THE LAST SEVERAL DAYS.
A STRONG LOW PRESSURE SYSTEM WILL MOVE INTO THE GREAT LAKES TODAY
IMPACTING AVIATION ROUTES THROUGH DTX-ORD-MSP. A TRAILING COLD
FRONT WILL CROSS STL THIS AFTERNOON...THEN MOVE EAST INTO THE OHIO
AND TN VALLEYS TONIGHT. SCATTERED TO NUMEROUS SHOWERS/STORMS WILL
BE FOUND ALONG THE FRONT...WITH SEVERE STORMS POSSIBLE FROM DTX-
STL. THIS UNSETTLED WEATHER ACTIVITY IS NOT EXPECTED TO REACH THE
MID ATLANTIC REGION UNTIL LATER THURSDAY. UNTIL THEN...FROM THIS
AFTERNOON THROUGH MID DAY THURSDAY...MAINLY VFR CONDITIONS WILL
EXIST. CAN`T RULE OUT A BRIEF PERIOD OF FOG LATE TONIGHT AND EARLY
THURSDAY...BUT IT SHOULD BE PATCHY AND CONFINED MAINLY TO THE
RIVER VALLEYS.
EXTENDED DISCUSSION...
COLD FRONT WILL BRING THREAT OF SHOWERS AND STORMS TO THE AREA
LATE THURSDAY AND THURSDAY NIGHT. FROPA IS EXPECTED THURSDAY
NIGHT. THIS FRONTAL PASSAGE WILL NOT BE A CLEAN SWEEP OF
AIRMASSES...THE MAJORITY OF THE MODELS INDICATING THE FRONT WILL
STALL OVER THE CAROLINAS FRIDAY...FOLLOWED BY DEVELOPMENT OF LOW
PRESSURE ALONG THE FRONT FRIDAY NIGHT...TRACKING NORTHEAST THROUGH
THE REGION SATURDAY. CONFIDENCE IS BEGINNING TO INCREASE THAT AN
EXTENDED PERIOD OF MVFR...POSSIBLY IFR...WILL EXIST FRIDAY NIGHT
INTO SATURDAY. LOW CONFIDENCE FORECAST FOR SUNDAY. HALF THE MODELS
BLOW THE SYSTEM OFF THE COAST CLEARING US FROM THE WEST SUNDAY.
OTHER MODEL SOLUTIONS HANG ON TO THE LOWER LEVEL CLOUDINESS PER
DEVELOPMENT OF LOW LEVEL EASTERLY WINDS OFF THE ATLANTIC...SIMILAR
TO WHAT TRANSPIRED THE FIRST HALF OF THIS WEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PM
NEAR TERM...CF/JH/PM
SHORT TERM...NF
LONG TERM...JH
AVIATION...PM
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1056 PM CDT THU SEP 11 2014
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.UPDATE...
ISSUED AT 935 PM CDT THU SEP 11 2014
SKIES HAVE CLEARED OVER NORTH CENTRAL WI AND TEMPS HAVE QUICKLY PLUMMETED
INTO THE MID TO UPPER 30S IN THE TYPICAL COLD SPOTS. HAVE LOWERED
MIN TEMPS...EXPANDED THE FROST ADVISORY FARTHER SOUTHEAST...AND UPGRADED
TO A FREEZE WARNING IN VILAS...ONEIDA AND LINCOLN COUNTIES. ALSO
CONSIDERED UPGRADING TO A FREEZE WARNING FOR FLORENCE...FOREST AND
LANGLADE...BUT THINK THAT MIN TEMPS WILL BE RIGHT AROUND THE FREEZING
MARK THERE. MID/HIGH CLOUDS IN ADVANCE OF APPROACHING UPPER TROF
HAVE MOVD INTO SW MN...BUT WERE GENERALLY DISSIPATING AS THEY SHIFTED
TOWARD WI. EXPECT THESE CLOUDS WILL NOT ARRIVE IN THE FROST/FREEZE
AREAS UNTIL 10Z-12Z...SO PLENTY OF TIME FOR TEMPS TO DROP OFF.
SCATTERED SPRINKLES HAVE BEEN DRIFTING SE ACROSS THE FORECAST AREA
THIS EVG...BUT SHOULD END OR MOVE OUT BY AROUND MIDNIGHT.
&&
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 254 PM CDT THU SEP 11 2014
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A 1037MB
CANADIAN HIGH PRESSURE SYSTEM BUILDING SOUTHEAST ACROSS THE NORTHERN
PLAINS AND MISSISSIPPI VALLEY. THE COMBO OF NORTHERLY FLOW OFF LAKE
SUPERIOR AND DIURNAL HEATING HAS MAINTAINED THE BROKEN TO OVERCAST
CONDITIONS ACROSS THE REGION. CLOUDS ARE LOOKING MORE CELLULAR OVER
N-C WISCONSIN INDICATING A DIURNAL COMPONENT TO THE CLOUD MASS.
SCATTERED SHOWERS ARE OCCURRING OVER NORTHEAST MINNESOTA AND
NORTHWEST WISCONSIN...WITH HELP FROM A WEAK SHORTWAVE OVER THAT
REGION. THIS WAVE IS LIFTING OFF TO THE NORTHEAST...SO DO NOT THINK
THE SHOWER ACTIVITY WILL REACH INTO N-C WISCONSIN THIS AFTERNOON.
THE NEXT SHORTWAVE IS DIVING SOUTHEAST OVER SOUTHERN MONTANA AND
WILL MOVE EAST TOWARDS THE REGION TOMORROW. THE MAIN CONCERNS ARE
FROST POTENTIAL TONIGHT AND LIGHT RAIN CHANCES TOMORROW.
TONIGHT...CANADIAN HIGH PRESSURE WILL BUILD TOWARDS THE REGION AS A
POTENT SHORTWAVE MOVES ACROSS THE NORTHERN PLAINS. AS SURFACE
PRESSURE RISES...LOW LEVEL FLOW WILL BECOME BROADLY
ANTICYCLONIC...WHICH WILL PROMOTE BREAKING UP OF THE LOW STRATUS.
HOWEVER...EVEN THOUGH THE FLOW WILL BECOME LIGHT...TRAJECTORIES ARE
ONSHORE OFF LAKE SUPERIOR WHERE DELTA T/S ARE SUFFICIENT FOR LAKE
CLOUDS. ADDITIONALLY...THERE IS REALLY NO SOURCE OF DRY AIR TO
BE FOUND ACROSS THE REGION. EVEN THOUGH CLOUDS OVER THE WESTERN
PART OF THE STATE APPEAR TO HAVE A DIURNAL LOOK TO THEM...CLOUDS
ORIGINATING OFF LAKE SUPERIOR COULD BECOME TRAPPED BENEATH THE
NOCTURNAL INVERSION. FURTHERMORE...MID AND HIGH CLOUDS WILL BE
INCREASING AFTER MIDNIGHT AHEAD OF THE SHORTWAVE OVER THE PLAINS.
ALL OF THIS MAKES FOR A LOW CONFIDENCE CLOUD/TEMP/FROST FORECAST.
BECAUSE WE ARE ALREADY OFF TO A COLD START...ANY AMOUNT OF CLEARING
WILL CAUSE TEMPS TO FALL QUICKLY OVER N-C WISCONSIN. MET/MAV/MEX
GUIDANCE ALL SHOW LOW TEMPS IN THE LOWER 30S OVER N-C WISCONSIN. WILL
ERROR ON THE SIDE OF CAUTION BECAUSE OF THIS POTENTIAL AND ISSUE A
FROST ADVISORY FOR N-C WISCONSIN. THE REST OF THE AREA SHOULD SEE
TEMPS IN THE UPPER 30S TO MIDDLE 40S.
FRIDAY...THE POTENT SHORTWAVE WILL MOVE ACROSS THE NORTHERN
MISSISSIPPI VALLEY AND INTO WESTERN WISCONSIN. EVEN THOUGH QG
FORCING AHEAD OF THE WAVE LOOKS RATHER IMPRESSIVE...MOISTURE WILL
ONLY BE 60 TO 80 PCT OF NORMAL AND INSTABILITY IS RATHER POOR.
CHANCES FOR PRECIP WILL IMPROVE DURING THE AFTERNOON AS THE WAVE
APPROACHES AND UPPER DIVERGENCE INCREASES. MODELS ARE ALSO
INDICATING MID-LEVEL CONVERGENCE OVER NORTHEAST AND EAST-CENTRAL
WISCONSIN THAT COULD PROVIDE A FOCUS FOR A BAND OF LIGHT RAIN. WILL
INCREASE PRECIP CHANCE IN THIS AREA FOR THE AFTERNOON.
NORTH-CENTRAL WILL HAVE THE NEXT BEST CHANCE OF SEEING RAIN WHERE
THE DEFORMATION ZONE APPROACHES DURING THE AFTERNOON. SHOULD BE
ANOTHER CLOUDY AND COOL DAY WITH HIGHS IN THE LOW TO MID 50S.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 254 PM CDT THU SEP 11 2014
LIGHT RAIN SHOULD END IN EASTERN WISCONSIN FRIDAY EVENING
AS THE UPPER SYSTEM EXITS. IF THERE IS SUFFICIENT CLEARING THERE COULD
BE A FREEZE OR FROST IN NORTHCENTRAL WISCONSIN FRIDAY NIGHT.
SUNNY AND COOL WEATHER SATURDAY AS A SURFACE HIGH MOVES BY. CLOUDS WILL
INCREASE SUNDAY AS A WEAK FRONTAL SYSTEM APPROACHES FROM THE NORTHERN
PLAINS. NOT MUCH MOISTURE AVAILABLE SO ONLY EXPECT SCATTERED SHOWERS
SUNDAY NIGHT AND MONDAY WITH THE FRONTAL PASSAGE. THEN DRY AND SEASONABLE
FOR MUCH OF THE REMINDER OF NEXT WEEK WITH NORTHWEST FLOW ALOFT.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1051 PM CDT THU SEP 11 2014
SKIES HAVE CLEARED OVER MOST OF THE FORECAST AREA LATE THIS EVG...
WITH ONLY SOME LINGERING CLOUDS OVER EC WI. WILL PROBABLY SEE SOME
PATCHY FOG OVERNIGHT BEFORE MID/HIGH CLOUDS INCREASE AHEAD OF AN
APPROACHING UPPER LEVEL DISTURBANCE. THIS SYSTEM WILL GENERATE
LIGHT RAIN OVER THE REGION...ESPECIALLY DURING THE AFTERNOON AND
EVEING. CIGS SHOULD DETERIORATE TO MVFR DURING THE AFTERNOON...AND
IFR BY EARLY EVENING.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY UNTIL 8 AM CDT FRIDAY FOR WIZ011>013-019>021-030-
031.
FREEZE WARNING UNTIL 8 AM CDT FRIDAY FOR WIZ005-010-018.
&&
$$
UPDATE.........KIECKBUSCH
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......KIECKBUSCH
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
943 PM CDT THU SEP 11 2014
NEW INFORMATION ADDED TO UPDATE SECTION
.UPDATE...
ISSUED AT 935 PM CDT THU SEP 11 2014
SKIES HAVE CLEARED OVER NORTH CENTRAL WI AND TEMPS HAVE QUICKLY PLUMMETED
INTO THE MID TO UPPER 30S IN THE TYPICAL COLD SPOTS. HAVE LOWERED
MIN TEMPS...EXPANDED THE FROST ADVISORY FARTHER SOUTHEAST...AND UPGRADED
TO A FREEZE WARNING IN VILAS...ONEIDA AND LINCOLN COUNTIES. ALSO
CONSIDERED UPGRADING TO A FREEZE WARNING FOR FLORENCE...FOREST AND
LANGLADE...BUT THINK THAT MIN TEMPS WILL BE RIGHT AROUND THE FREEZING
MARK THERE. MID/HIGH CLOUDS IN ADVANCE OF APPROACHING UPPER TROF
HAVE MOVD INTO SW MN...BUT WERE GENERALLY DISSIPATING AS THEY SHIFTED
TOWARD WI. EXPECT THESE CLOUDS WILL NOT ARRIVE IN THE FROST/FREEZE
AREAS UNTIL 10Z-12Z...SO PLENTY OF TIME FOR TEMPS TO DROP OFF.
SCATTERED SPRINKLES HAVE BEEN DRIFTING SE ACROSS THE FORECAST AREA
THIS EVG...BUT SHOULD END OR MOVE OUT BY AROUND MIDNIGHT.
&&
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 254 PM CDT THU SEP 11 2014
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A 1037MB
CANADIAN HIGH PRESSURE SYSTEM BUILDING SOUTHEAST ACROSS THE NORTHERN
PLAINS AND MISSISSIPPI VALLEY. THE COMBO OF NORTHERLY FLOW OFF LAKE
SUPERIOR AND DIURNAL HEATING HAS MAINTAINED THE BROKEN TO OVERCAST
CONDITIONS ACROSS THE REGION. CLOUDS ARE LOOKING MORE CELLULAR OVER
N-C WISCONSIN INDICATING A DIURNAL COMPONENT TO THE CLOUD MASS.
SCATTERED SHOWERS ARE OCCURRING OVER NORTHEAST MINNESOTA AND
NORTHWEST WISCONSIN...WITH HELP FROM A WEAK SHORTWAVE OVER THAT
REGION. THIS WAVE IS LIFTING OFF TO THE NORTHEAST...SO DO NOT THINK
THE SHOWER ACTIVITY WILL REACH INTO N-C WISCONSIN THIS AFTERNOON.
THE NEXT SHORTWAVE IS DIVING SOUTHEAST OVER SOUTHERN MONTANA AND
WILL MOVE EAST TOWARDS THE REGION TOMORROW. THE MAIN CONCERNS ARE
FROST POTENTIAL TONIGHT AND LIGHT RAIN CHANCES TOMORROW.
TONIGHT...CANADIAN HIGH PRESSURE WILL BUILD TOWARDS THE REGION AS A
POTENT SHORTWAVE MOVES ACROSS THE NORTHERN PLAINS. AS SURFACE
PRESSURE RISES...LOW LEVEL FLOW WILL BECOME BROADLY
ANTICYCLONIC...WHICH WILL PROMOTE BREAKING UP OF THE LOW STRATUS.
HOWEVER...EVEN THOUGH THE FLOW WILL BECOME LIGHT...TRAJECTORIES ARE
ONSHORE OFF LAKE SUPERIOR WHERE DELTA T/S ARE SUFFICIENT FOR LAKE
CLOUDS. ADDITIONALLY...THERE IS REALLY NO SOURCE OF DRY AIR TO
BE FOUND ACROSS THE REGION. EVEN THOUGH CLOUDS OVER THE WESTERN
PART OF THE STATE APPEAR TO HAVE A DIURNAL LOOK TO THEM...CLOUDS
ORIGINATING OFF LAKE SUPERIOR COULD BECOME TRAPPED BENEATH THE
NOCTURNAL INVERSION. FURTHERMORE...MID AND HIGH CLOUDS WILL BE
INCREASING AFTER MIDNIGHT AHEAD OF THE SHORTWAVE OVER THE PLAINS.
ALL OF THIS MAKES FOR A LOW CONFIDENCE CLOUD/TEMP/FROST FORECAST.
BECAUSE WE ARE ALREADY OFF TO A COLD START...ANY AMOUNT OF CLEARING
WILL CAUSE TEMPS TO FALL QUICKLY OVER N-C WISCONSIN. MET/MAV/MEX
GUIDANCE ALL SHOW LOW TEMPS IN THE LOWER 30S OVER N-C WISCONSIN. WILL
ERROR ON THE SIDE OF CAUTION BECAUSE OF THIS POTENTIAL AND ISSUE A
FROST ADVISORY FOR N-C WISCONSIN. THE REST OF THE AREA SHOULD SEE
TEMPS IN THE UPPER 30S TO MIDDLE 40S.
FRIDAY...THE POTENT SHORTWAVE WILL MOVE ACROSS THE NORTHERN
MISSISSIPPI VALLEY AND INTO WESTERN WISCONSIN. EVEN THOUGH QG
FORCING AHEAD OF THE WAVE LOOKS RATHER IMPRESSIVE...MOISTURE WILL
ONLY BE 60 TO 80 PCT OF NORMAL AND INSTABILITY IS RATHER POOR.
CHANCES FOR PRECIP WILL IMPROVE DURING THE AFTERNOON AS THE WAVE
APPROACHES AND UPPER DIVERGENCE INCREASES. MODELS ARE ALSO
INDICATING MID-LEVEL CONVERGENCE OVER NORTHEAST AND EAST-CENTRAL
WISCONSIN THAT COULD PROVIDE A FOCUS FOR A BAND OF LIGHT RAIN. WILL
INCREASE PRECIP CHANCE IN THIS AREA FOR THE AFTERNOON.
NORTH-CENTRAL WILL HAVE THE NEXT BEST CHANCE OF SEEING RAIN WHERE
THE DEFORMATION ZONE APPROACHES DURING THE AFTERNOON. SHOULD BE
ANOTHER CLOUDY AND COOL DAY WITH HIGHS IN THE LOW TO MID 50S.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 254 PM CDT THU SEP 11 2014
LIGHT RAIN SHOULD END IN EASTERN WISCONSIN FRIDAY EVENING
AS THE UPPER SYSTEM EXITS. IF THERE IS SUFFICIENT CLEARING THERE COULD
BE A FREEZE OR FROST IN NORTHCENTRAL WISCONSIN FRIDAY NIGHT.
SUNNY AND COOL WEATHER SATURDAY AS A SURFACE HIGH MOVES BY. CLOUDS WILL
INCREASE SUNDAY AS A WEAK FRONTAL SYSTEM APPROACHES FROM THE NORTHERN
PLAINS. NOT MUCH MOISTURE AVAILABLE SO ONLY EXPECT SCATTERED SHOWERS
SUNDAY NIGHT AND MONDAY WITH THE FRONTAL PASSAGE. THEN DRY AND SEASONABLE
FOR MUCH OF THE REMINDER OF NEXT WEEK WITH NORTHWEST FLOW ALOFT.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 624 PM CDT THU SEP 11 2014
EXPECT BKN-OVC STRATOCUMULUS TO GRADUALLY SCATTER OUT OVER MOST OF
THE FORECAST AREA DURING THE THE MID TO LATE EVENING HOURS AS A
RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION. COULD SEE A
PERIOD OF PATCHY FOG OVERNIGHT BEFORE MID/HIGH CLOUDS INCREASE
AHEAD OF AN UPPER LEVEL DISTURBANCE. THIS SYSTEM WILL GENERATE
SOME LIGHT RAIN OR SHOWERS OVER THE REGION...MAINLY DURING THE
AFTERNOON. SOME MVFR CIGS MAY ACCOMPANY THE STEADIER RAINFALL
DURING THE MID TO LATE AFTERNOON.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY UNTIL 8 AM CDT FRIDAY FOR WIZ011>013-019>021-030-
031.
FREEZE WARNING UNTIL 8 AM CDT FRIDAY FOR WIZ005-010-018.
&&
$$
UPDATE.........KIECKBUSCH
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......KIECKBUSCH
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
923 PM CDT THU SEP 11 2014
.UPDATE...
WATCHING TEMPERATURES FALL A BIT FASTER THAN EARLIER FORECAST SO
ADJUSTED DOWN A BIT. LOOKS AS IF BOTH MILWAUKEE AND MADISON WILL
SET RECORDS FOR LOWEST MAX TEMP FOR THE DATE...BUT WITH EXPECTED
ONSHORE WINDS IN THE EAST...AND INCREASING CLOUD COVER IN THE WEST
WILL WAIT UNTIL END OF CLIMATE DAY TO ISSUE RECORD REPORTS IN
ORDER TO GET THE EXACT READINGS FOR THE NEW RECORDS.
NARROW BAND OF LIGHT LAKE-EFFECT RAIN SHOWERS WORKING EAST AND
WILL REACH THE MID-LAKE BUOY AROUND MIDNIGHT. TERMINAL DOPPLER
RADAR AT MKE STARTING TO SHOW WEAK RETURNS DEVELOPING BETWEEN
WESTERN SHORE AND MID-LAKE BUOY AS SHORELINE OB SITES AND SHIP OBS
INDICATING NNW WINDS...POSSIBLY THE BEGINNING OF LAND BREEZE
DEPICTED ON LATEST HRRR RUN.
THIS LATEST HRRR HOLDS THE BAND OFF THE WESTERN SHORE THROUGH 14Z
FRIDAY WITH THE DEVELOPING LAND BREEZE KEEPING CONVERGENCE ZONE
JUST TO THE EAST OF LAND. ADJUSTED TIMING AND LOWERED POPS DURING
THE OVERNIGHT DUE TO SLOWER ADVANCE OF LINE AND POTENTIAL FOR
CONVERGENCE STAYING OFFSHORE.
&&
.AVIATION/06Z TAFS/...
VFR CIGS IN THE WEST...WITH CIGS IN THE EAST JUST ABOVE MVFR
LIMITS. WILL KEEP VFR CONDITIONS GOING IN THE WEST UNTIL SYSTEM
RAIN MOVES IN ON/AFTER 15Z. IN THE EAST...EXPECT MVFR CIGS WITH
LAKE-EFFECT BAND AS IT NEARS SHORE BETWEEN 09Z AND 12Z.
&&
.MARINE...
SMALL CRAFT ADVISORY ALLOWED TO EXPIRE...BUT ANOTHER MAY BE NEEDED
IF WINDS TURN NNE AND INCREASE TO 10 TO 20 KNOTS CURRENTLY IN FORECAST
...INCREASING WAVES TOWARD THE 3 TO 5 FOOT MARK BY MORNING.
HOWEVER SHORT TERM...RAPID UPDATE MODELS INDICATING THE POTENTIAL
FOR A LAND BREEZE...WHICH WOULD LIMIT WAVE HEIGHTS. WILL GO WITH
NO HEADLINE FOR NOW AND CONTINUE TO MONITOR WESTERN SHORE WINDS.
&&
.PREV DISCUSSION... /ISSUED 312 PM CDT THU SEP 11 2014/
SHORT TERM...
TONIGHT - CONFIDENCE...MEDIUM
CHILLY AIRMASS WILL PERSIST ASSOCIATED WITH LARGE CANADIAN HIGH
BUILDING INTO THE NORTHERN PLAINS. CLOUD COVER QUITE STUBBORN WITH
COLD AIR ALOFT AND TRAPPING INVERSION. SOME DIURNAL LOOK HAS
TAKEN SHAPE IN PARTS OF WRN WI BUT CU HAS FILLED RIGHT BACK IN.
EXPECTING THE CLOUD COVER TO LARGELY REMAIN INTACT. THE NAM MOS
HAS BEEN DOING A GREAT JOB ON THESE TRENDS. AIRMASS IS QUITE DRY
WITH SOME DEW POINTS IN THE UPPER 30S SO ANY CLEARING WOULD RESULT
IN A COLDER THAN EXPECTED DROPOFF. LATER IN THE NIGHT ONSHORE FLOW
SUPPORTIVE OF AT LEAST A CHANCE OF SOME LAKE EFFECT RAIN SHOWERS
THAT THE MODELS ARE LATCHING ONTO TO VARYING DEGREES. SO WILL
RETAIN THE INHERITED POPS IN THE FAR SE ADJACENT TO LAKE MICHIGAN.
FRIDAY - CONFIDENCE...MEDIUM
LARGE AREA OF HIGH PRESSURE WILL EXPAND THROUGH THE PLAINS AND INTO
THE WESTERN GREAT LAKES. THIS WILL KEEP THE MUCH COOLER REGIME IN PLACE.
MEANWHILE THINGS BECOME MORE INTERESTING ALOFT AS VIGOROUS SHORTWAVE
APPROACHES AND STRONG JET CORE PUNCHES ON EASTERN SIDE OF TROUGH AXIS.
DECENT UPWARD DIVERGENCE AND SOME LOWER LEVEL FRONTOGENETICAL FORCING
EVOLVES. MODELS HAVE BEEN TRENDING WETTER WITH THIS SYSTEM AND GIVEN
THE CONSENSUS ON THIS HAVE BOOSTED POPS TO CATEGORICAL LEVELS. IN
ADDITION...LAKE EFFECT SHRA POTENTIAL WILL CONTINUE.
FRIDAY NIGHT THROUGH SUNDAY...FORECAST CONFIDENCE MEDIUM TO HIGH.
THE 540 DM THICKNESS TROUGH OVER THE NRN ROCKIES WILL MOVE ACROSS
SRN WI FRI NT. A BAND OF 850-600 MB FRONTOGENESIS WILL DEVELOP
AHEAD OF THE FEATURE AND CONTINUE THE LIGHT RAIN INTO FRI NT.
CLEARING WILL OCCUR FROM WEST TO EAST DURING THE EARLY MORNING
HOURS OF SAT. IF THE CLEARING DOES OCCUR SEVERAL HOURS BEFORE
SUNRISE...TEMPS WILL FALL INTO THE MID TO UPPER 30S OVER SOUTH
CENTRAL WI. A LITTLE FROST IS POSSIBLE IN THE VALLEY AREAS OF SAUK
COUNTY.
SHORTWAVE RIDGING AND SFC HIGH PRESSURE TO PREVAIL ON SAT WITH THE
HIGH SHIFTING MORE INTO ERN WI FOR SAT NT. 925 MB TEMPS AROUND 8C
WOULD SUGGEST HIGH TEMPS AROUND 60F. LGT SLY FLOW WILL DEVELOP
OVER SOUTH CENTRAL WI LATE SAT NT WITH 925-850 MB WARM ADVECTION
BEGINNING. THUS DO NOT EXPECT TEMPS TO DROP ENOUGH FOR FROST. SWLY
WINDS AND WARM ADVECTION TO BOOST TEMPS INTO THE MID 60S FOR SUN
IN RESPONSE TO WEAK SHORTWAVE TROUGHS AND A SFC LOW MOVING EWD
ALONG THE CANADIAN BORDER.
LONG TERM...
SUNDAY NIGHT THROUGH THURSDAY...FORECAST CONFIDENCE MEDIUM.
A SHORTWAVE TROUGH WILL DIG SEWD FROM CANADA INTO SRN WI FOR LATE
SUN NT AND MON. THIS WILL BRING CHANCES OF LGT RAIN TO THE AREA.
OTHERWISE...HIGH PRESSURE WILL PREVAIL THROUGH THE REMAINDER OF
THE PERIOD WITH PLEASANT AUTUMN CONDITIONS.
AVIATION/00Z TAFS/...WIDESPREAD MVFR CIGS WILL PERSIST INTO THIS EVENING
THOUGH SOME BKN VFR CIGS TRENDING SOUTH FROM WC WI. FOR MUCH OF THE AREA
THE CLOUDS WON/T BE GOING ANYWHERE TONIGHT. DEVELOPING ONSHORE FLOW...
LINGERING COLD AIR ALOFT AND APPROACHING SHORTWAVE FOR FRIDAY
WILL MEAN THAT CLOUD COVER WILL PERSIST. ANY LAKE ENHANCED CLOUD
COVER WILL LIKELY REINFORCE THE MVFR CIGS. INVERSION HEIGHTS RISE UP
TO 4-6K FEET LATER TONIGHT INTO FRIDAY MORNING SO LIKE THE IDEA OF
SEEING SOME LAKE EFFECT SHRA IN THE SOUTHEAST. THE NAM AMOUNTS LOOK
A BIT OVERDONE. SYNOPTIC INDUCED PRECIP KICKS IN FROM WEST TO EAST
DURING THE MORNING WITH WIDESPREAD LIGHT RAIN LIKELY BY AFTERNOON.
MARINE...WILL LET SMALL CRAFT ADVISORY GO TO EXPIRATION TIME. EVEN
THOUGH WINDS HAVE EASED BELOW CRITERIA...A BEND TO A MORE NORTHERLY
DIRECTION LIKELY KEEPING SOME OF THE HIGHER WAVES AROUND FOR A TIME.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...REM
TONIGHT/FRIDAY AND AVIATION/MARINE...COLLAR
FRIDAY NIGHT THROUGH THURSDAY...GEHRING
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
630 PM CDT THU SEP 11 2014
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 254 PM CDT THU SEP 11 2014
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A 1037MB
CANADIAN HIGH PRESSURE SYSTEM BUILDING SOUTHEAST ACROSS THE NORTHERN
PLAINS AND MISSISSIPPI VALLEY. THE COMBO OF NORTHERLY FLOW OFF LAKE
SUPERIOR AND DIURNAL HEATING HAS MAINTAINED THE BROKEN TO OVERCAST
CONDITIONS ACROSS THE REGION. CLOUDS ARE LOOKING MORE CELLULAR OVER
N-C WISCONSIN INDICATING A DIURNAL COMPONENT TO THE CLOUD MASS.
SCATTERED SHOWERS ARE OCCURRING OVER NORTHEAST MINNESOTA AND
NORTHWEST WISCONSIN...WITH HELP FROM A WEAK SHORTWAVE OVER THAT
REGION. THIS WAVE IS LIFTING OFF TO THE NORTHEAST...SO DO NOT THINK
THE SHOWER ACTIVITY WILL REACH INTO N-C WISCONSIN THIS AFTERNOON.
THE NEXT SHORTWAVE IS DIVING SOUTHEAST OVER SOUTHERN MONTANA AND
WILL MOVE EAST TOWARDS THE REGION TOMORROW. THE MAIN CONCERNS ARE
FROST POTENTIAL TONIGHT AND LIGHT RAIN CHANCES TOMORROW.
TONIGHT...CANADIAN HIGH PRESSURE WILL BUILD TOWARDS THE REGION AS A
POTENT SHORTWAVE MOVES ACROSS THE NORTHERN PLAINS. AS SURFACE
PRESSURE RISES...LOW LEVEL FLOW WILL BECOME BROADLY
ANTICYCLONIC...WHICH WILL PROMOTE BREAKING UP OF THE LOW STRATUS.
HOWEVER...EVEN THOUGH THE FLOW WILL BECOME LIGHT...TRAJECTORIES ARE
ONSHORE OFF LAKE SUPERIOR WHERE DELTA T/S ARE SUFFICIENT FOR LAKE
CLOUDS. ADDITIONALLY...THERE IS REALLY NO SOURCE OF DRY AIR TO
BE FOUND ACROSS THE REGION. EVEN THOUGH CLOUDS OVER THE WESTERN
PART OF THE STATE APPEAR TO HAVE A DIURNAL LOOK TO THEM...CLOUDS
ORIGINATING OFF LAKE SUPERIOR COULD BECOME TRAPPED BENEATH THE
NOCTURNAL INVERSION. FURTHERMORE...MID AND HIGH CLOUDS WILL BE
INCREASING AFTER MIDNIGHT AHEAD OF THE SHORTWAVE OVER THE PLAINS.
ALL OF THIS MAKES FOR A LOW CONFIDENCE CLOUD/TEMP/FROST FORECAST.
BECAUSE WE ARE ALREADY OFF TO A COLD START...ANY AMOUNT OF CLEARING
WILL CAUSE TEMPS TO FALL QUICKLY OVER N-C WISCONSIN. MET/MAV/MEX
GUIDANCE ALL SHOW LOW TEMPS IN THE LOWER 30S OVER N-C WISCONSIN. WILL
ERROR ON THE SIDE OF CAUTION BECAUSE OF THIS POTENTIAL AND ISSUE A
FROST ADVISORY FOR N-C WISCONSIN. THE REST OF THE AREA SHOULD SEE
TEMPS IN THE UPPER 30S TO MIDDLE 40S.
FRIDAY...THE POTENT SHORTWAVE WILL MOVE ACROSS THE NORTHERN
MISSISSIPPI VALLEY AND INTO WESTERN WISCONSIN. EVEN THOUGH QG
FORCING AHEAD OF THE WAVE LOOKS RATHER IMPRESSIVE...MOISTURE WILL
ONLY BE 60 TO 80 PCT OF NORMAL AND INSTABILITY IS RATHER POOR.
CHANCES FOR PRECIP WILL IMPROVE DURING THE AFTERNOON AS THE WAVE
APPROACHES AND UPPER DIVERGENCE INCREASES. MODELS ARE ALSO
INDICATING MID-LEVEL CONVERGENCE OVER NORTHEAST AND EAST-CENTRAL
WISCONSIN THAT COULD PROVIDE A FOCUS FOR A BAND OF LIGHT RAIN. WILL
INCREASE PRECIP CHANCE IN THIS AREA FOR THE AFTERNOON.
NORTH-CENTRAL WILL HAVE THE NEXT BEST CHANCE OF SEEING RAIN WHERE
THE DEFORMATION ZONE APPROACHES DURING THE AFTERNOON. SHOULD BE
ANOTHER CLOUDY AND COOL DAY WITH HIGHS IN THE LOW TO MID 50S.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 254 PM CDT THU SEP 11 2014
LIGHT RAIN SHOULD END IN EASTERN WISCONSIN FRIDAY EVENING
AS THE UPPER SYSTEM EXITS. IF THERE IS SUFFICIENT CLEARING THERE COULD
BE A FREEZE OR FROST IN NORTHCENTRAL WISCONSIN FRIDAY NIGHT.
SUNNY AND COOL WEATHER SATURDAY AS A SURFACE HIGH MOVES BY. CLOUDS WILL
INCREASE SUNDAY AS A WEAK FRONTAL SYSTEM APPROACHES FROM THE NORTHERN
PLAINS. NOT MUCH MOISTURE AVAILABLE SO ONLY EXPECT SCATTERED SHOWERS
SUNDAY NIGHT AND MONDAY WITH THE FRONTAL PASSAGE. THEN DRY AND SEASONABLE
FOR MUCH OF THE REMINDER OF NEXT WEEK WITH NORTHWEST FLOW ALOFT.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 624 PM CDT THU SEP 11 2014
EXPECT BKN-OVC STRATOCUMULUS TO GRADUALLY SCATTER OUT OVER MOST OF
THE FORECAST AREA DURING THE THE MID TO LATE EVENING HOURS AS A
RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION. COULD SEE A
PERIOD OF PATCHY FOG OVERNIGHT BEFORE MID/HIGH CLOUDS INCREASE
AHEAD OF AN UPPER LEVEL DISTURBANCE. THIS SYSTEM WILL GENERATE
SOME LIGHT RAIN OR SHOWERS OVER THE REGION...MAINLY DURING THE
AFTERNOON. SOME MVFR CIGS MAY ACCOMPANY THE STEADIER RAINFALL
DURING THE MID TO LATE AFTERNOON.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY FROM MIDNIGHT TONIGHT TO 8 AM CDT FRIDAY FOR
WIZ005-010>012-018-019.
&&
$$
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......KIECKBUSCH
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 242 PM CDT WED SEP 10 2014
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A STRONG
LOW PRESSURE SYSTEM TRACKING NORTHEAST TOWARDS MANITOWOC WHILE A
POTENT COLD FRONT IS DROPPING SOUTHEAST FROM THE BAY OF GREEN BAY TO
JUST WEST OF OSHKOSH. MOST OF THE HEAVIER RAINFALL HAS EXITED THE
REGION TO THE NORTHEAST EXCEPT FOR FAR WESTERN ONEIDA AND VILAS
COUNTIES. AREAS OF DRIZZLE OR VERY LIGHT RAIN WILL GRADUALLY
DIMINISH THROUGH THE REST OF THE AFTERNOON AS THE CYCLONE EXITS THE
REGION. OBSERVATIONS INDICATE A WIDESPREAD 1.5 TO 2.5 INCHES OF
RAIN OVER NORTH-CENTRAL WISCONSIN FOR A STORM TOTAL. AREA RIVERS
SEEM TO BE HOLDING UP WELL AND HAVE RECEIVED NO REPORTS OF FLOODING
SO FAR. WILL LET THE FLOOD WATCH EXPIRE WITH THIS FORECAST
ISSUANCE. GUSTY NORTHWEST WINDS ARE USHERING IN THE FIRST TASTE OF
FALL BEHIND THE COLD FRONT. TEMPERATURES ARE FALLING INTO THE 40S
AND 50S BEHIND THE FRONT...WHILE READINGS REMAIN IN THE 60S AND 70S
AHEAD OF THE FRONT. TIMING THE END OF THE PRECIP...TEMPS...AND
MARINE HEADLINES ARE THE MAIN FORECAST CONCERNS.
TONIGHT...LOW PRESSURE WILL CONTINUE TO MOVE TO THE NORTHEAST INTO
EASTERN ONTARIO AND WESTERN QUEBEC WHILE THE STRONG COLD FRONT MOVES
EAST ACROSS THE LOWER PENINSULA OF MICHIGAN. BEHIND THE
FRONT...GUSTY NORTHWEST WINDS WILL USHER IN A MIGHTY CHILLY AIRMASS
FOR THIS TIME OF THE YEAR. WITH LOW INVERSION HEIGHTS OF AROUND
875MB...THE AIRMASS WILL BE PLENTY COLD ENOUGH TO SUPPORT LAKE
EFFECT RAIN SHOWERS OFF LAKE SUPERIOR...WHICH WILL LIKELY JUST
IMPACT VILAS COUNTY AS WIND TRAJECTORIES ARE TOO NORTHERLY FOR A
DIRECT HIT. PLENTY OF LOW STRATUS UPSTREAM BENEATH THIS
INVERSION...AND WITH MOISTURE FLUXES OFF LAKE SUPERIOR COMBINED WITH
THERMAL TROUGHING...HAVE A TOUGH TIME SEEING ANY SORT OF CLEARING
TAKING PLACE. PERHAPS A FEW HOLES IN THE OVERCAST IN THE
DOWNSLOPING AREAS OF NORTHEAST WISCONSIN. LOWS FALLING INTO THE
UPPER 30S NORTH TO UPPER 40S SOUTHEAST.
THURSDAY...850MB TEMPERATURES CONTINUE TO FALL AS CANADIAN HIGH
PRESSURE BUILDS TOWARDS THE REGION. THE INVERSION WILL REMAIN STOUT
ABOVE STEEP LOW LEVEL LAPSE RATES. AS A RESULT...CLOUDY CONDITIONS
IN THE MORNING WILL BE SLOW TO BREAK UP...ESPECIALLY WITH MID-LEVEL
CLOUDS ARRIVING IN THE AFTERNOON. SO EXPECT SKY CONDITIONS TO
REMAIN AT LEAST PARTLY SUNNY OR MOSTLY CLOUDY THROUGH THE
DAY. HIGHS RANGING FROM THE UPPER 40S NORTH TO MIDDLE 50S SOUTH.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 242 PM CDT WED SEP 10 2014
LARGE SURFACE HIGH SHOULD COVER THE NORTHERN AND
CENTRAL PLAINS ALL THE WAY EAST TO THE GREAT LAKES AND NORTHERN
OHIO VALLEY THURSDAY NIGHT THROUGH FRIDAY EVENING. WHILE THIS
WOULD NORMALLY RESULT IN A DRY FORECAST AND CLEAR SKIES THERE IS A
SHARP UPPER LEVEL TROUGH THAT WILL BE MOVING ACROSS WISCONSIN
FRIDAY AND FRIDAY EVENING THAT SHOULD BE STRONG ENOUGH TO PRODUCE
SOME LIGHT RAIN DESPITE SURFACE HIGH PRESSURE AND DRY AIR IN THE
LOW LEVELS. THE CLOUDS AND LIGHT RAIN SHOULD KEEP HIGH TEMPERATURES
LOWER THAN MOS GUIDANCE FRIDAY SO WENT ABOUT 3 DEGREES LOWER IN
MOST PLACES.
LOW TEMPERATURES SATURDAY MORNING WILL DEPEND ON HOW QUICKLY THE
UPPER SYSTEM EXITS FRIDAY NIGHT AND HOW QUICKLY SKIES CLEAR. THE
ECMWF IS SLOWER THAN THE GFS AND ITS SOLUTION WOULD KEEP CLOUDS
ALL NIGHT AND HOLD TEMPERATES UP. WE ARE SIDING WITH THE QUICKER
GFS AND THUS WENT LOWER THAN GUIDANCE FOR LOWS FRIDAY NIGHT.
NICE WEATHER EXPECTED SATURDAY THROUGH SUNDAY WITH A SLIGHT CHANCE
OF SHOWERS SUNDAY EVENING AS THE NEXT UPPER TROUGH APPROACHES.
THAT SYSTEM SHOULD BRING SHOWERS SUNDAY NIGHT AND MONDAY.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1149 AM CDT WED SEP 10 2014
A STRONG SURFACE LOW IS PROJECTED TO TRACK NORTHEAST THIS AFTERNOON
INTO NORTHERN LOWER MICHIGAN AND INTO SOUTHEAST ONTARIO/ SOUTHWEST
QUEBEC TONIGHT. RAIN AND DRIZZLE WILL CONTINUE INTO MIDDLE
AFTERNOON...BUT THEN DIMINISH FROM SOUTHWEST TO NORTHEAST ACROSS THE
REGION. CIGS AND VSBYS WILL MAINLY BE IN THE MVFR/IFR RANGE FOR AS
LONG AS THE RAIN/DRIZZLE CONTINUES. ONCE THE PRECIP EXITS...VSBYS
WILL IMPROVE TO P6SM BUT CIGS WILL REMAIN BETWEEN 1K-2K FEET. VERY
SLOW IMPROVEMENT IS EXPECTED ON WEDNESDAY WITH SOME BREAKING UP OF
THE CLOUD MASS DURING THE AFTERNOON. WINDS WILL SHIFT AROUND TO THE
NORTHWEST THIS AFTERNOON AND REMAIN GUSTY THROUGH THURSDAY MORNING.
&&
.MARINE...
ISSUED AT 242 PM CDT WED SEP 10 2014
NORTHWEST WINDS WILL RAPIDLY STRENGTHEN LATE THIS
AFTERNOON INTO EARLY THIS EVENING BEHIND A DEPARTING LOW PRESSURE
SYSTEM. WITH INCREASING INSTABILITY OVER THE CENTRAL BAY OF GREEN
BAY...MIXING WILL SUPPORT 40 TO 45 KT WINDS AT 925 AND 900MB TO
REACH THE SURFACE. THIS WIND DIRECTION IS ALSO FAVORABLE FOR HIGHER
END GUSTS THROUGH DEATHS DOOR. ISSUE A GALE WARNING FOR THE CENTRAL
BAY AND LAKE MICHIGAN SHORELINE THROUGH 18Z...THOUGH GALES WILL
LIKELY ONLY BE POSSIBLE THROUGH SUNRISE ON THURSDAY.
&&
.HYDROLOGY...
ISSUED AT 242 PM CDT WED SEP 10 2014
NORTH-CENTRAL WISCONSIN PICKED UP THE MOST RAINFALL FOR
THIS EVENT...WITH SCATTERED LOCATIONS REACHING ABOVE 2 INCHES. NO
REPORTS OF FLOODING SO FAR TODAY. AREA RIVERS ARE RISING BUT ALSO
REPORTING NO SIGNIFICANT PROBLEMS. WILL CANCEL THE FLOOD WATCH WITH
THIS ISSUANCE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......MPC
MARINE.........MPC
HYDROLOGY......MPC
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
246 AM CDT FRI SEP 12 2014
.DISCUSSION...
905 PM CDT
MAIN FOCUS THIS EVENING IS ON POPS. FIRST...AN AREA OF SHEARED
VORTICITY STRETCHING FROM SOUTHERN NEBRASKA TO SOUTHEAST IOWA IS
CONTINUING TO GENERATE SOME SPOTTY SHOWER ACTIVITY ACROSS THESE
AREAS BUT THE FOCUS OF FORCING SHOULD DIMINISH THROUGH THE
EVENING. THUS AM NOT EXPECTING MEASURABLE PRECIP WITH THIS FEATURE
THOUGH SOME SPRINKLES CANNOT BE RULED OUT.
ATTENTION TURNS TO LAKE EFFECT SHOWERS THROUGH THE OVERNIGHT. WITH
HIGH PRESSURE SPREADING ACROSS THE CENTRAL/NORTHERN PLAINS AND MID
AND UPPER MISSISSIPPI RIVER VALLEY THE EVOLVING PRESSURE GRADIENT
WILL LEAD TO A NORTHEASTERLY LOW LEVEL FLOW OVERNIGHT. LAKE TO H85
DELTA T OF AROUND 17C IS CERTAINLY SUPPORTIVE OF LAKE EFFECT BUT
INVERSION HEIGHTS ARE ON THE LOWER END OF THE FAVORABLE SCALE
PEAKING AROUND 6 KFT. RADAR CONTINUES TO SHOW BANDS OF WEAK
RETURNS OVER SOUTHERN LAKE MICHIGAN WITH SOME SPOTTY RAIN REPORTED
EARLIER IN NW INDIANA. RADAR TRENDS SHOW THE LOW LEVEL FLOW HAS
BEGUN TO TURN NORTHEASTERLY. EXPECT THAT INTENSITY MAY BEGIN TO
INCREASE WITH TIME AS CONVERGENCE LIKELY BECOMES BETTER FOCUSED
INTO THE OVERNIGHT. STILL DECIDING ON DETAILS BUT AM PLANNING ON
INCREASING POPS AND ADJUSTING TO COVERAGE WORDING ACROSS MUCH OF
THE CHICAGO METRO THROUGH THE OVERNIGHT...WITH BEST CHANCES AFTER
MIDNIGHT. OTHERWISE HAVE ADJUSTED TEMPS TO BETTER REFLECT HOURLY
TRENDS WITH MINIMAL CHANGE TO OVERNIGHT LOWS.
MDB
//PREV DISCUSSION...
240 PM...FORECAST CONCERNS INCLUDE MUCH BELOW NORMAL TEMPERATURES
AND CHANCES FOR SHOWERS THROUGH SATURDAY AND AGAIN ON MONDAY.
STRATUS DECK HAS REMAINED MOSTLY OVERCAST TODAY AND THAT HAS HELD
TEMPS IN THE LOWER/MID 50S MOST AREAS...SOME 20 TO 25 DEGREES
BELOW NORMAL FOR MID SEPTEMBER. SEE CLIMATE SECTION BELOW FOR
RECORDS. CLOUD COVER IS EXPECTED TO REMAIN AT LEAST BROKEN IF NOT
OVERCAST OVERNIGHT INTO FRIDAY MORNING...SO NOT EXPECTING MUCH OF
A SWING IN TEMPS WITH LOWS TONIGHT IN THE MID/UPPER 40S.
AS COLDER AIR CONTINUES TO SPREAD ACROSS THE AREA...A FEW LAKE
EFFECT RAIN SHOWERS HAVE DEVELOPED OVER THE SOUTHEASTERN PART OF
THE LAKE. AS HIGH PRESSURE MOVES NORTH OF THE AREA TONIGHT...
WINDS WILL TURN MORE NORTHEAST AND THESE LAKE EFFECT RAIN SHOWERS
WILL BEGIN TO AFFECT NORTHEAST IL OVERNIGHT INTO FRIDAY MORNING.
COVERAGE REMAINS A BIT UNCERTAIN AND HAVE ONLY BUMPED POPS UP TO
LOW CHANCE. TRENDS WILL NEED TO BE MONITORED LATER TONIGHT WITH
THE POSSIBILITY THAT POPS WILL NEED TO BE BUMPED UP FURTHER.
LAKE EFFECT RAIN SHOWERS WILL CONTINUE INLAND ACROSS NORTHERN IL
FRIDAY MORNING AS FLOW TURNS MORE EAST/NORTHEAST. CLOUD COVER WILL
LIKELY REMAIN MOSTLY CLOUDY AND THIS COULD LIMIT TEMPS TO JUST THE
50S AGAIN ON FRIDAY. SOUTHERN AREAS MAY SEE A FEW BREAKS WITH THE
POTENTIAL TO REACH 60...BUT OVERALL FRIDAY WILL CONTINUE MUCH
BELOW NORMAL.
AN UPPER WAVE WILL MOVE ACROSS THE REGION FRIDAY AFTERNOON INTO
FRIDAY EVENING WITH SHOWERS/LIGHT RAIN SPREADING ACROSS THE
NORTHWEST CWA IN THE AFTERNOON THEN ACROSS MUCH OF THE AREA EARLY
FRIDAY EVENING. BUMPED POPS UP SOME...WITH LIKELY OVER THE
NORTHERN TWO THIRDS OF THE CWA...POSSIBLE POPS WILL NEED TO BE
INCREASED HERE AS WELL...THOUGH TOTAL QFP AMOUNTS SHOULD BE IN THE
0.25 TO 0.5 INCH RANGE. THIS WAVE IS FAIRLY PROGRESSIVE...SO
TRIMMED POPS FROM THE WEST OVERNIGHT. LAKE EFFECT RAIN SHOWERS MAY
CONTINUE INTO NORTHWEST INDIANA SATURDAY MORNING BEFORE ENDING IN
THE AFTERNOON.
DESPITE SOME SUNSHINE SATURDAY...AIRMASS WILL BE EVEN COLDER THAN
TODAY AND FRIDAY. NOT SURE HOW MUCH MID SEPTEMBER SUN WILL AID
TEMP INCREASE SO MAINTAINED JUST LOWER 60S FOR HIGHS. HIGH
PRESSURE PASSES ACROSS THE REGION SATURDAY NIGHT INTO SUNDAY
MORNING WITH LOWS DIPPING INTO THE LOWER 40S MOST AREAS...BUT
WARMER IN THE IMMEDIATE CHICAGO METRO AREA.
ANOTHER FAST MOVING WAVE WILL MOVE ACROSS THE AREA MONDAY
BRINGING ANOTHER CHANCE OF SHOWERS. DEPENDING ON TIMING...CLOUD
COVER AND PRECIP COULD HOLD TEMPS DOWN MONDAY BUT FOR NOW HAVE
MAINTAINED 60S. BEYOND MONDAY...HIGH PRESSURE SPREADS ACROSS THE
REGION WITH DRY WEATHER EXPECTED MID WEEK BUT TEMPS STILL BELOW
NORMAL. CMS
&&
.CLIMATE...
900 PM CDT SEP 11 2014
AN UNSEASONABLY COOL AIR MASS OVER THE REGION INTO THE WEEKEND
COULD PUT RECORD TEMPERATURES IN JEOPARDY AT CHICAGO AND
ROCKFORD. RECORD LOW MAX TEMPERATURES ARE MOST LIKELY TO BE
THREATENED.
RECORD LOW MAX TEMPERATURES SEPTEMBER 12-13
-------------------------------------------
SEPTEMBER 12 SEPTEMBER 13
------------ ------------
CHICAGO 53/1902 55/1880
ROCKFORD 56/1943 55/1970
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* NNW/N WINDS OVERNIGHT INTO EARLY FRIDAY TURNING NORTHEAST.
* PERIODS OF MVFR CIGS. IFR A POSSIBILITY ESPECIALLY FRIDAY
EVENING.
* RAIN MOVING ACROSS THE REGION FRIDAY EVENING.
BMD
//DISCUSSION...UPDATED 06Z...
HIGH PRESSURE IS STARTING TO BUILD IN FROM THE NORTHWEST OVERNIGHT
WITH LOWER CLOUDS STARTING TO ERODE. RFD ALREADY SOLIDLY IN AREA OF
VFR CONDITIONS...AND INTERMITTENTLY VFR CONDITIONS ARE IN PLACE
OVER THE CHICAGO TERMINALS. EXPECT MOST OF THE OVERNIGHT HOURS TO BE
VFR UNTIL WINDS TURN NORTHEAST FRIDAY WITH FLOW OFF THE LAKE
BRINGING LOWER LAKE EFFECT CLOUDINESS/SHOWERS BACK OVERHEAD. TIMING
THIS SHIFT REMAINS A BIT UNCERTAIN WITH LOWER RES MODEL GUIDANCE
SUGGESTING EARLIER TIMING WHILE HIGH RES GUIDANCE SUGGEST THAT THE
NNW/N WINDS WILL HOLD ON LATER INTO THE MORNING. FOR NOW...FEEL THAT
THE HIGH RES GUIDANCE HAS A BETTER HANDLE ON THE LOW LEVEL
CONVERGENCE OVER THE LAKE WHICH WOULD RESULT IN WINDS STAYING BACKED
LONGER OVER THE CHICAGO TERMINALS. THAT SAID THERE REMAINS LOW
CONFIDENCE ON TIMING THE SWITCH TO NORTHEAST...THOUGH WHEN IT DOES
HAPPEN IT WILL LIKELY BE IN THE 10-12KT RANGE. LAKE EFFECT LIGHT
SHOWERS/SPRINKLES ARE EXPECTED TO MOVE INLAND AND MAY MOVE OVER THE
TERMINALS PERIODICALLY...THOUGH IMPACTS TO VSBY SHOULD BE MINIMAL.
AN UPPER LEVEL DISTURBANCE IS PROGGED TO MOVE OVER THE AREA FRIDAY
EVENING AND SHOULD BRING MORE WIDESPREAD RAIN TO THE AREA...ALONG
WITH THE POSSIBILITY OF IFR CIGS.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN WINDS OVERNIGHT...AND HIGH CONFIDENCE IN A
WIND SHIFT TO THE NORTHEAST...BUT LOW CONFIDENCE IN TIMING.
* MEDIUM CONFIDENCE IN CIG TRENDS...EXCEPT LOW CONFIDENCE FRIDAY
EVENING WITH RAIN.
* MEDIUM-HIGH CONFIDENCE IN RAIN MOVING ACROSS THE REGION FRIDAY
EVENING.
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
SATURDAY...VFR.
SUNDAY...SCHC SHRA LATE.
MONDAY...CHC SHRA THEN SCHC SHRA OVERNIGHT. MVFR CIGS PSBL.
TUESDAY AND WEDNESDAY...VFR.
JEE
&&
.MARINE...
246 AM CDT
RIDGING IS IN PLACE THIS MORNING OVER LAKE MICHIGAN AND WINDS
SHOULD HOLD FAIRLY STEADY THROUGH THE DAY TODAY. TONIGHT
HOWEVER...LOW PRESSURE IS PROGGED TO DEVELOP OVER THE UPPER OHIO
VALLEY AND LIFT TOWARDS THE EASTERN LAKES CAUSING THE GRADIENT TO
TIGHTEN. IN ADDITION...STRONG LAKE INDUCED INSTABILITY WITH THE
UNSEASONABLY COOL AIRMASS AND COLD UPPER LOW WILL RESULT IN A BAND
OF LAKE EFFECT SHOWERS AND THUNDERSTORMS THAT WILL RESULT IN
ADDITIONAL LOW LEVEL CONVERGENCE. THE NET RESULT OF ALL THIS WILL
BE AN INCREASE IN WINDS...ESPECIALLY OVER THE SOUTH HALF OF THE
LAKE WHERE WINDS ARE EXPECTED TO INCREASE TO 30 KT FOR A SHORT
PERIOD...AND CANNOT RULE OUT SOME GALES...ESPECIALLY NEAR THE
BETTER CONVERGENCE WITHIN THE LAKE EFFECT BAND. THE SMALL CRAFT
ADVISORY MAY HAVE TO BE EXTENDED...PARTICULARLY FOR THE INDIANA
ZONES. CONDITIONS MAY BE MORE MARGINAL OVER THE ILLINOIS ZONES
WITH OFFSHORE FLOW. IN ADDITION TO THE STRONGER WINDS...CONDITIONS
WILL BE FAVORABLE FOR THE FORMATION OF WATERSPOUTS TONIGHT INTO
EARLY SATURDAY. WINDS WILL DIMINISH THROUGH THE DAY SATURDAY AS
HIGH PRESSURE BUILDS OVERHEAD...THEN TURN SOUTHWEST AND FRESHEN UP
OVER THE NORTH HALF OF THE LAKE SUNDAY AS THE HIGH SLIPS EAST OF
THE AREA AND ANOTHER LOW SKIRTS EAST OVER THE CANADIAN PRAIRIES.
THIS LOW WILL DRAG ANOTHER COLD FRONT ACROSS LAKE MICHIGAN ON
MONDAY.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014 UNTIL 5 PM SATURDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 5 PM SATURDAY.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
233 AM CDT Fri Sep 12 2014
.SHORT TERM...(Today)
ISSUED AT 233 AM CDT FRI SEP 12 2014
Short-wave trough evident on 07z/2am water vapor imagery over
western South Dakota will track E/NE today, spreading clouds and
showers across Iowa into north-central Illinois. All models agree
that precip will remain west of the KILX CWA until afternoon, so
have gone with a mostly cloudy and dry forecast this morning. Still
some model discrepancies concerning QPF with this system: however,
it appears the strongest forcing for widespread precip will
generally shift into Wisconsin/northern Illinois later today. Have
therefore focused highest PoPs across the northwest CWA this
afternoon, with dry conditions expected to continue for the balance
of the day east of the I-55 corridor. High temperatures will once
again be well below normal for this time of year, with readings
ranging from the upper 50s north to the middle 60s far south.
&&
.LONG TERM...(Tonight through Thursday)
ISSUED AT 233 AM CDT FRI SEP 12 2014
Upper wave will pass into the Great Lakes tonight, with most
concentrated area of showers skimming central Illinois to the
north. As a result of the expected track of the strongest forcing
and the diurnal nature of the precip, have focused chance PoPs
across the north, with only slight chances further south. Total
rainfall with this feature will be quite light, only amounting to
one tenth of an inch or less. Showers will come to an end from west
to east after midnight, with partial clearing occurring across the
Illinois River Valley late.
High pressure will build in from the Plains on Saturday, resulting
in a return to sunny and dry conditions. Temperatures will remain
below normal through the weekend, with afternoon highs mainly in the
60s and overnight lows dipping into the 40s. Next northern stream
short-wave is still on target for early next week. Both the GFS and
ECMWF show this feature tracking across central Illinois on Monday,
and both models try to bring light precip into the NW CWA as early
as Sunday night. Given dry airmass initially in place, have gone
with a dry forecast across the board Sunday night followed by high
chance PoPs on Monday as stronger forcing and deeper moisture
arrive. After that, cool and dry weather will once again take hold
across the Midwest Tuesday through Thursday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
ISSUED AT 1144 PM CDT THU SEP 11 2014
MVFR clouds will prevail over the next 24 hours, with some
periodic IFR cloud heights possible late tonight and early Friday
morning. Did not include IFR, as RAP soundings show 1200FT as the
base of the cloud layer. Subsidence under a cold dome of high
pressure is keeping a blanket of low moisture in place across much
of the Upper Midwest. A fast moving shortwave continues to trigger a
narrow band of showers across south-central Iowa, that are drifting
toward N IL. No precip was included at PIA the rest of the night,
as the trajectory of the showers and forecast soundings do not
look supportive of precip that far south with this wave. There is
some indication that drizzle may develop for PIA, SPI and BMI
later tonight into Friday morning. As the upper trough rotates
into N IL tomorrow, coverage of showers will increase west of
I-55. We included a VCSH in the afternoon for all sites but CMI,
where VCSH was included after 00z. Shower chances will continue
through the end of the TAF period at 06z.
Winds will remain north to northeast over the next 24 hours, with
wind speeds climbing to around 10kt during the day, and
diminishing to 5-7kt at night.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1235 AM CDT FRI SEP 12 2014
.DISCUSSION...
905 PM CDT
MAIN FOCUS THIS EVENING IS ON POPS. FIRST...AN AREA OF SHEARED
VORTICITY STRETCHING FROM SOUTHERN NEBRASKA TO SOUTHEAST IOWA IS
CONTINUING TO GENERATE SOME SPOTTY SHOWER ACTIVITY ACROSS THESE
AREAS BUT THE FOCUS OF FORCING SHOULD DIMINISH THROUGH THE
EVENING. THUS AM NOT EXPECTING MEASURABLE PRECIP WITH THIS FEATURE
THOUGH SOME SPRINKLES CANNOT BE RULED OUT.
ATTENTION TURNS TO LAKE EFFECT SHOWERS THROUGH THE OVERNIGHT. WITH
HIGH PRESSURE SPREADING ACROSS THE CENTRAL/NORTHERN PLAINS AND MID
AND UPPER MISSISSIPPI RIVER VALLEY THE EVOLVING PRESSURE GRADIENT
WILL LEAD TO A NORTHEASTERLY LOW LEVEL FLOW OVERNIGHT. LAKE TO H85
DELTA T OF AROUND 17C IS CERTAINLY SUPPORTIVE OF LAKE EFFECT BUT
INVERSION HEIGHTS ARE ON THE LOWER END OF THE FAVORABLE SCALE
PEAKING AROUND 6 KFT. RADAR CONTINUES TO SHOW BANDS OF WEAK
RETURNS OVER SOUTHERN LAKE MICHIGAN WITH SOME SPOTTY RAIN REPORTED
EARLIER IN NW INDIANA. RADAR TRENDS SHOW THE LOW LEVEL FLOW HAS
BEGUN TO TURN NORTHEASTERLY. EXPECT THAT INTENSITY MAY BEGIN TO
INCREASE WITH TIME AS CONVERGENCE LIKELY BECOMES BETTER FOCUSED
INTO THE OVERNIGHT. STILL DECIDING ON DETAILS BUT AM PLANNING ON
INCREASING POPS AND ADJUSTING TO COVERAGE WORDING ACROSS MUCH OF
THE CHICAGO METRO THROUGH THE OVERNIGHT...WITH BEST CHANCES AFTER
MIDNIGHT. OTHERWISE HAVE ADJUSTED TEMPS TO BETTER REFLECT HOURLY
TRENDS WITH MINIMAL CHANGE TO OVERNIGHT LOWS.
MDB
//PREV DISCUSSION...
240 PM...FORECAST CONCERNS INCLUDE MUCH BELOW NORMAL TEMPERATURES
AND CHANCES FOR SHOWERS THROUGH SATURDAY AND AGAIN ON MONDAY.
STRATUS DECK HAS REMAINED MOSTLY OVERCAST TODAY AND THAT HAS HELD
TEMPS IN THE LOWER/MID 50S MOST AREAS...SOME 20 TO 25 DEGREES
BELOW NORMAL FOR MID SEPTEMBER. SEE CLIMATE SECTION BELOW FOR
RECORDS. CLOUD COVER IS EXPECTED TO REMAIN AT LEAST BROKEN IF NOT
OVERCAST OVERNIGHT INTO FRIDAY MORNING...SO NOT EXPECTING MUCH OF
A SWING IN TEMPS WITH LOWS TONIGHT IN THE MID/UPPER 40S.
AS COLDER AIR CONTINUES TO SPREAD ACROSS THE AREA...A FEW LAKE
EFFECT RAIN SHOWERS HAVE DEVELOPED OVER THE SOUTHEASTERN PART OF
THE LAKE. AS HIGH PRESSURE MOVES NORTH OF THE AREA TONIGHT...
WINDS WILL TURN MORE NORTHEAST AND THESE LAKE EFFECT RAIN SHOWERS
WILL BEGIN TO AFFECT NORTHEAST IL OVERNIGHT INTO FRIDAY MORNING.
COVERAGE REMAINS A BIT UNCERTAIN AND HAVE ONLY BUMPED POPS UP TO
LOW CHANCE. TRENDS WILL NEED TO BE MONITORED LATER TONIGHT WITH
THE POSSIBILITY THAT POPS WILL NEED TO BE BUMPED UP FURTHER.
LAKE EFFECT RAIN SHOWERS WILL CONTINUE INLAND ACROSS NORTHERN IL
FRIDAY MORNING AS FLOW TURNS MORE EAST/NORTHEAST. CLOUD COVER WILL
LIKELY REMAIN MOSTLY CLOUDY AND THIS COULD LIMIT TEMPS TO JUST THE
50S AGAIN ON FRIDAY. SOUTHERN AREAS MAY SEE A FEW BREAKS WITH THE
POTENTIAL TO REACH 60...BUT OVERALL FRIDAY WILL CONTINUE MUCH
BELOW NORMAL.
AN UPPER WAVE WILL MOVE ACROSS THE REGION FRIDAY AFTERNOON INTO
FRIDAY EVENING WITH SHOWERS/LIGHT RAIN SPREADING ACROSS THE
NORTHWEST CWA IN THE AFTERNOON THEN ACROSS MUCH OF THE AREA EARLY
FRIDAY EVENING. BUMPED POPS UP SOME...WITH LIKELY OVER THE
NORTHERN TWO THIRDS OF THE CWA...POSSIBLE POPS WILL NEED TO BE
INCREASED HERE AS WELL...THOUGH TOTAL QFP AMOUNTS SHOULD BE IN THE
0.25 TO 0.5 INCH RANGE. THIS WAVE IS FAIRLY PROGRESSIVE...SO
TRIMMED POPS FROM THE WEST OVERNIGHT. LAKE EFFECT RAIN SHOWERS MAY
CONTINUE INTO NORTHWEST INDIANA SATURDAY MORNING BEFORE ENDING IN
THE AFTERNOON.
DESPITE SOME SUNSHINE SATURDAY...AIRMASS WILL BE EVEN COLDER THAN
TODAY AND FRIDAY. NOT SURE HOW MUCH MID SEPTEMBER SUN WILL AID
TEMP INCREASE SO MAINTAINED JUST LOWER 60S FOR HIGHS. HIGH
PRESSURE PASSES ACROSS THE REGION SATURDAY NIGHT INTO SUNDAY
MORNING WITH LOWS DIPPING INTO THE LOWER 40S MOST AREAS...BUT
WARMER IN THE IMMEDIATE CHICAGO METRO AREA.
ANOTHER FAST MOVING WAVE WILL MOVE ACROSS THE AREA MONDAY
BRINGING ANOTHER CHANCE OF SHOWERS. DEPENDING ON TIMING...CLOUD
COVER AND PRECIP COULD HOLD TEMPS DOWN MONDAY BUT FOR NOW HAVE
MAINTAINED 60S. BEYOND MONDAY...HIGH PRESSURE SPREADS ACROSS THE
REGION WITH DRY WEATHER EXPECTED MID WEEK BUT TEMPS STILL BELOW
NORMAL. CMS
&&
.CLIMATE...
900 PM CDT SEP 11 2014
AN UNSEASONABLY COOL AIR MASS OVER THE REGION INTO THE WEEKEND
COULD PUT RECORD TEMPERATURES IN JEOPARDY AT CHICAGO AND
ROCKFORD. RECORD LOW MAX TEMPERATURES ARE MOST LIKELY TO BE
THREATENED.
RECORD LOW MAX TEMPERATURES SEPTEMBER 12-13
-------------------------------------------
SEPTEMBER 12 SEPTEMBER 13
------------ ------------
CHICAGO 53/1902 55/1880
ROCKFORD 56/1943 55/1970
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* NNW/N WINDS OVERNIGHT INTO EARLY FRIDAY TURNING NORTHEAST.
* PERIODS OF MVFR CIGS. IFR A POSSIBILITY ESPECIALLY FRIDAY
EVENING.
* RAIN MOVING ACROSS THE REGION FRIDAY EVENING.
BMD
//DISCUSSION...UPDATED 06Z...
HIGH PRESSURE IS STARTING TO BUILD IN FROM THE NORTHWEST OVERNIGHT
WITH LOWER CLOUDS STARTING TO ERODE. RFD ALREADY SOLIDLY IN AREA OF
VFR CONDITIONS...AND INTERMITTENTLY VFR CONDITIONS ARE IN PLACE
OVER THE CHICAGO TERMINALS. EXPECT MOST OF THE OVERNIGHT HOURS TO BE
VFR UNTIL WINDS TURN NORTHEAST FRIDAY WITH FLOW OFF THE LAKE
BRINGING LOWER LAKE EFFECT CLOUDINESS/SHOWERS BACK OVERHEAD. TIMING
THIS SHIFT REMAINS A BIT UNCERTAIN WITH LOWER RES MODEL GUIDANCE
SUGGESTING EARLIER TIMING WHILE HIGH RES GUIDANCE SUGGEST THAT THE
NNW/N WINDS WILL HOLD ON LATER INTO THE MORNING. FOR NOW...FEEL THAT
THE HIGH RES GUIDANCE HAS A BETTER HANDLE ON THE LOW LEVEL
CONVERGENCE OVER THE LAKE WHICH WOULD RESULT IN WINDS STAYING BACKED
LONGER OVER THE CHICAGO TERMINALS. THAT SAID THERE REMAINS LOW
CONFIDENCE ON TIMING THE SWITCH TO NORTHEAST...THOUGH WHEN IT DOES
HAPPEN IT WILL LIKELY BE IN THE 10-12KT RANGE. LAKE EFFECT LIGHT
SHOWERS/SPRINKLES ARE EXPECTED TO MOVE INLAND AND MAY MOVE OVER THE
TERMINALS PERIODICALLY...THOUGH IMPACTS TO VSBY SHOULD BE MINIMAL.
AN UPPER LEVEL DISTURBANCE IS PROGGED TO MOVE OVER THE AREA FRIDAY
EVENING AND SHOULD BRING MORE WIDESPREAD RAIN TO THE AREA...ALONG
WITH THE POSSIBILITY OF IFR CIGS.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN WINDS OVERNIGHT...AND HIGH CONFIDENCE IN A
WIND SHIFT TO THE NORTHEAST...BUT LOW CONFIDENCE IN TIMING.
* MEDIUM CONFIDENCE IN CIG TRENDS...EXCEPT LOW CONFIDENCE FRIDAY
EVENING WITH RAIN.
* MEDIUM-HIGH CONFIDENCE IN RAIN MOVING ACROSS THE REGION FRIDAY
EVENING.
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
SATURDAY...VFR.
SUNDAY...SCHC SHRA LATE.
MONDAY...CHC SHRA THEN SCHC SHRA OVERNIGHT. MVFR CIGS PSBL.
TUESDAY AND WEDNESDAY...VFR.
JEE
&&
.MARINE...
209 PM CDT
STRONG LOW PRESSURE SYSTEM THAT BROUGHT THE GALE FORCE WINDS HAS
CONTINUED TO LIFT NORTHEAST AWAY FROM THE GREAT LAKES REGION...WITH
THE GRADIENT OVER LAKE MICHIGAN STEADILY WEAKENING. THE GRADIENT
WILL REMAIN JUST ENOUGH TO PRODUCE WINDS BETWEEN 15 AND 25 KT
OVERNIGHT GENERALLY FROM THE NORTH...BEGINNING TO TURN SLIGHTLY
NORTHEAST AHEAD OF THE BROAD RIDGE OF HIGH PRESSURE OVER THE CENTRAL
PLAINS THAT IS POISED TO ARRIVE SATURDAY INTO SUNDAY MORNING.
ANOTHER FRONTAL BOUNDARY WILL ARRIVE FRIDAY EVENING WHICH WILL
PROVIDE A REINFORCING PUSH OF GUSTY NORTH WINDS TO THE LAKE...WITH
THE GRADIENT BEING SLIGHTLY TIGHTER ALONG THE SOUTHERN HALF OF THE
LAKE FRIDAY NIGHT THROUGH EARLY SATURDAY. WAVES WILL REMAIN ELEVATED
THROUGH FRIDAY NIGHT...CREATING HAZARDOUS WAVES TO SMALL CRAFT
THROUGH THIS PERIOD. THEN THE WAVES SHOULD STEADILY DIMINISH BY
EARLY SATURDAY MORNING TO ALLOW THE SMALL CRAFT TO END. HOWEVER IF
THE WINDS REMAIN ELEVATED...THIS WILL KEEP WAVES UP AS WELL THROUGH
DAYBREAK SAT. HIGH PRESSURE IS THEN POISED TO BUILD OVER LAKE
MICHIGAN SATURDAY EVENING AND CONTINUE THROUGH SUNDAY. WHICH WILL
THEN PROVIDE MUCH LIGHTER WINDS AND SUBSIDING WAVES.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014 UNTIL 5 PM SATURDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 5 PM SATURDAY.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1144 PM CDT Thu Sep 11 2014
.UPDATE...
ISSUED AT 900 PM CDT THU SEP 11 2014
High pressure at the surface extends from Montana to Ohio, but an
abundance of low level moisture trapped near the surface is
keeping cloud cover across a majority of the Upper Midwest. An
upper level trough positioned on top of the surface high is
focusing jet stream dynamics from South Dakota through the Great
Lakes to Ontario. Short waves in the leading edge of the upper
trough are triggering spotty showers and spreading mid and high
clouds toward western IL. Overall, a blanket of low clouds will
dominate the next 24 to 36 hours, with sunshine probably not making
much of an appearance until Saturday afternoon. Unseasonably cool
conditions will continue during that time as well, with diurnal
swings in temperature generally less than 10F.
The main updates for this evening were to increase cloud cover
tonight and tomorrow, and trim a degree or two from the low temps
across our northern counties. Updated info will be available shortly.
&&
.SHORT TERM...(Tonight)
ISSUED AT 259 PM CDT THU SEP 11 2014
Cold front just south of the Ohio River Valley this afternoon as
high pressure builds into the Midwest. Northerly flow at the sfc
bringing unseasonably cool temps into the region, in stark contrast
to the weather of the last few days. Cooler temperatures expected
to continue into the overnight hours. With lows dipping into the
upper 40s across the nrn portions of the state...and low 50s before
dawn for much of Illinois. Breaks in the cloud cover off to the
west not having much success in moving into the region. As a
result, continued cloud coverage expected through the overnight
hours as llvl RH has remained trapped. Both NAM and HRRR slow to
move clouds out, though some brief clearing is possible NW of the
Illinois River.
&&
.LONG TERM...(Friday through Thursday)
ISSUED AT 259 PM CDT THU SEP 11 2014
Cool and cloudy conditions are expected again Friday as low level
northerly flow continues with a strong capping inversion at around
850 mb. An upper level shortwave will be rapidly approaching from
the west. The axis of the shortwave expected to cross Illinois late
Friday evening to early Saturday morning...pushing another frontal
boundary through the region. Current model forecasts are fairly
consistent keeping precipitation with this feature mainly north of
I-72...and modest amounts around 0.10 inches or less. Have PoPs
beginning Friday afternoon west of I-55 as lift associated with the
approaching shortwave begins...then PoPs spread through most areas
I-55 northward Friday evening. The system moves rapidly east-
northeastward leaving a cool and dry weekend behind it...with highs
in the 60s and lows in the 40s...as high pressure settles over the
area.
The next chance for precipitation will be Monday as models
consistently track another broad trough through the midwest. Cool
dry northwesterly flow aloft is expected to follow for the remainder
of the week with little chance for any precipitation and below
normal temperatures continuing.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
ISSUED AT 1144 PM CDT THU SEP 11 2014
MVFR clouds will prevail over the next 24 hours, with some
periodic IFR cloud heights possible late tonight and early Friday
morning. Did not include IFR, as RAP soundings show 1200FT as the
base of the cloud layer. Subsidence under a cold dome of high
pressure is keeping a blanket of low moisture in place across much
of the Upper Midwest. A fast moving shortwave continues to trigger a
narrow band of showers across south-central Iowa, that are drifting
toward N IL. No precip was included at PIA the rest of the night,
as the trajectory of the showers and forecast soundings do not
look supportive of precip that far south with this wave. There is
some indication that drizzle may develop for PIA, SPI and BMI
later tonight into Friday morning. As the upper trough rotates
into N IL tomorrow, coverage of showers will increase west of
I-55. We included a VCSH in the afternoon for all sites but CMI,
where VCSH was included after 00z. Shower chances will continue
through the end of the TAF period at 06z.
Winds will remain north to northeast over the next 24 hours, with
wind speeds climbing to around 10kt during the day, and
diminishing to 5-7kt at night.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHIMON
SHORT TERM...HJS
LONG TERM...ONTON
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS DES MOINES IA
333 AM CDT FRI SEP 12 2014
.SHORT TERM /TODAY/...
ISSUED AT 333 AM CDT FRI SEP 12 2014
PRECIP AND TEMP TRENDS WILL BE THE PRIMARY CONCERNS TODAY. RIGHT
ENTRANCE REGION DIVERGENCE OF STRONG 120KT JET FROM MO VALLEY INTO
SERN CANADA CONTINUES TO ENHANCE BROAD SWATH OF PRECIP FROM NE/KS
INTO THE NWRN HALF OF IA. FORCING IS MAINLY KINEMATIC AND MID LEVEL
BASED DRIVEN BY DIVERGENCE AND DPVA...AND ALTHOUGH THERE IS LITTLE
TO NO THETA-E ADVECTION BELOW 3KM...THERE DOES APPEAR TO BE FAIRLY
HIGH BASED FRONTOGENETICAL FORCING AND RESPONSE. ENHANCED SW-NE
PRECIP BANDS LINE UP FAIRLY NICELY WITH RAP H7/H5 FN DIVERGENCE AND
LOWER STATIC STABILITY NOTED BY SLIGHTLY NEGATIVE EPV IN THE SAME
LAYER. HIGH RES MODEL PRECIP DEPICTIONS ARE IN QUITE GOOD AGREEMENT
BUT LOOK SLOW AT THE MOMENT SUGGESTING PRECIP WILL MAINLY BE IN THE
MORNING...AND CERTAINLY BE EXITING TO THE EAST 21Z-00Z.
TEMPS WILL BE PROBLEMATIC WITH EXTREMELY ANOMALOUS AIRMASS JUST
UPSTREAM. BOTH THE NAEFS CLIMATOLOGICAL AND GEFS M-CLIMATE
PERCENTILES ARE IN THEIR LOWEST AND HIGHEST RESPECTIVE 1 PERCENT FOR
TEMPS AND MSLP. THIS COLD AIRMASS COMBINED WITH PRECIP WILL RESULT
IN LITTLE TEMP REBOUND TODAY AND SOME NON-DIURNAL TRENDS WITH HIGHS
NO BETTER THAN THE LOWER 50S. ALTHOUGH NOT IN THE FORECAST...WOULD
NOT BE SURPRISED TO SEE A FEW SPOTS STRUGGLE TO REACH 50F. THESE
HIGHS WOULD AGAIN BREAK MIN MAX RECORDS WHICH RANGE FROM 53-56F AT
MASON CITY...WATERLOO...DES MOINES AND OTTUMWA.
.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 333 AM CDT FRI SEP 12 2014
LITTLE CHANGES TO THE GOING FORECAST AS MODELS REMAIN IN AGREEMENT
BOTH FROM RUN TO RUN AND AMONG EACH OTHER. LARGE AREA OF HIGH
PRESSURE TO BUILD INTO THE STATE TONIGHT WITH DRY CONDITIONS AND
CLEARING SKIES. VERY COLD AIR FOR THIS TIME OF YEAR TO REMAIN IN
PLACE ACROSS THE REGION...WITH H85 TEMPS AROUND 0C TONIGHT AND ONLY
WARMING TO AROUND +5C THROUGH THE WEEKEND. WITH THE COOL AIR AND
HIGH PRESSURE IN PLACE TONIGHT...CLEAR SKIES AND LIGHT WINDS
TEMPERATURES EXPECTED TO DROP OFF QUITE A BIT. HOWEVER THE TEMPS MAY
BE TEMPERED SOME BY THE LINGERING MOISTURE FROM ALL THE RAIN THE
PAST FEW DAYS AND ADDITIONAL RAIN TODAY...WHICH LEADS TO BEING
SOMEWHAT HESITANT ON POTENTIAL FOR FROST FORMATION AS WELL.
THEREFORE STUCK WITH LOWS IN THE MID TO UPPER 30S AND SOME PATCHY
FROST WORDING ACROSS THE WEST/NORTH WHERE COOLEST TEMPS EXPECTED.
HIGH PRESSURE TO DOMINATE OVER THE WEEKEND...WITH TEMPS GRADUALLY
WARMING A BIT. OTHERWISE NEXT CHANCE FOR PRECIPITATION AS ANOTHER
WEAK UPPER LEVEL WAVE AND ASSOCIATED COLD FRONT DROPS THROUGH THE
REGION. ANOTHER LARGE AREA OF HIGH PRESSURE TO THEN BUILD INTO THE
CENTRAL US FOR MUCH OF NEXT WEEK. THERMAL PROFILES WARM SOME WHICH
SHOULD ALLOW TEMPERATURES TO CREEP BACK INTO THE 70S BY WEDNESDAY
INTO THURSDAY. A LARGER UPPER LEVEL WAVE THEN LOOKS TO DIG INTO THE
CENTRAL US BY NEXT FRIDAY INTO THE WEEKEND WHICH SHOULD BRING
ADDITIONAL CHANCES FOR PRECIPITATION TO MUCH OF THE AREA. EVEN WITH
THE WARMING BY THE END OF THE FORECAST PERIOD...TEMPERATURES WILL
REMAIN WELL BELOW THE SEASONAL AVERAGES THROUGH MUCH OF NEXT WEEK.
&&
.AVIATION...12/06Z
ISSUED AT 1159 PM CDT THU SEP 11 2014
CONDITIONS WILL CONTINUE TO DETERIORATE OVERNIGHT WITH CIGS AND
VSBYS DIMINISHING ESPECIALLY BETWEEN 09Z- 14Z. CIGS AND VSBYS EACH
MAY DROP TO IFR AT TIMES FRIDAY MORNING. PRECIPITATION WILL
GRADUALLY END FROM WEST TO EAST FRIDAY AFTERNOON. STRATUS LIKELY
TO LINGER THROUGH LATE AFTERNOON TO MID EVENING. THE WIND WILL
REMAIN 10KTS OR LESS THROUGH THE PERIOD.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...SMALL
LONG TERM...BEERENDS
AVIATION...DONAVON
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
215 AM EDT FRI SEP 12 2014
.UPDATE...
ISSUED AT 1252 AM EDT FRI SEP 12 2014
SPOTTY LIGHT RADAR RETURNS ARE SHOWING UP ACROSS LOCATIONS ALONG AND
SOUTH OF THE MOUNTAIN PARKWAY. THE LATEST HRRR TRENDS SUPPORT THE
CONTINUATION OF AT LEAST ISOLATED LIGHT RAIN/SHOWERS THROUGH DAWN...
AND GIVEN THE DEEP MOISTURE STILL IN PLACE...SEE NO REASON TO ARGUE.
HAVE EXPANDED THE ISOLATED POPS BACK TOWARDS THE I-64 CORRIDOR
THROUGH DAWN. THE REST OF THE FORECAST REMAINS ON TRACK.
UPDATE ISSUED AT 1039 PM EDT THU SEP 11 2014
UPDATED TO REMOVE THE HIGHER POPS FROM THE FORECAST AS RAIN SHOWERS
HAVE DIMINISHED ACROSS SOUTHEAST KENTUCKY. ISOLATED SHOWERS MAY STILL
BE POSSIBLE OVER THE NEXT HOUR...BUT WE SHOULD SEE A FAIRLY QUIET
SECOND HALF OF THE NIGHT. GIVEN THE PRESENCE OF THE WASHED OUT
BOUNDARY ACROSS OUR SOUTHERN AREAS...PLAN TO BRING SOME ISOLATED
SHOWERS BACK INTO THE FORECAST TOWARDS DAWN WITH THE ABUNDANCE OF
MOISTURE LOCATED ALONG THE FRONT. THIS COULD MANIFEST ITSELF MORE AS
DRIZZLE...BUT REGARDLESS...SOME POPS ARE WARRANTED.
OTHERWISE...HOURLY GRIDS SEEM PRETTY GOOD.
UPDATE ISSUED AT 727 PM EDT THU SEP 11 2014
UPDATED TO REMOVE THE LAST OF THE THUNDER. STILL WATCHING AN INTENSE
BAND OF SHOWERS AS THEY MOVE SOUTH ACROSS SOUTHEAST KENTUCKY. THESE
ARE PEGGED TO CLEAR THE SOUTHEAST COUNTIES BY 10 PM. THE REST OF THE
NIGHT SHOULD THEN FEATURE DRIER WEATHER. LOOKS LIKE STRATUS SHOULD
BUILD IN BEHIND THE STALLING COLD FRONT. IT IS POSSIBLE WE COULD SEE
A LITTLE DRIZZLE IF THE MOISTURE DEPTH CAN INCREASE ENOUGH. CERTAINLY
ENOUGH OF A THREAT TO LEAVE SOME SMALL POPS IN LATE TONIGHT. CLOUDS
WILL HOLD TOUGH THROUGH THE NIGHT AND MAY HOLD ON THROUGH MUCH OF THE
DAY TOMORROW AS WINDS TURN NORTH-NORTHEASTERLY...HELPING TO MAINTAIN
THE LOW CLOUDS. WITH THE CLOUDS...IT SHOULD HELP CUT DOWN ON THE FOG
POTENTIAL TONIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 400 PM EDT THU SEP 11 2014
A LINE OF CONVECTION DEVELOPED AND MOVED THROUGH SE KENTUCKY THIS
AFTERNOON. THE EFFECTIVE COLD FRONT APPEARS TO BE WITH THIS LINE. A
FEW SHOWERS HAVE DEVELOPED TO THE NW...BUT PRECIP HAS BEEN SPARSE.
MODELS HAVE NOT HANDLED THIS VERY WELL. IN LIGHT OF TRENDS...HAVE
GONE BELOW MODEL GUIDANCE FOR POPS OVER MUCH OF THE AREA FOR TONIGHT.
EVEN BEHIND THE FRONT...MOISTURE WILL LINGER...AND ADDITIONAL SHOWERS
CAN NOT BE RULED OUT ON FRIDAY OR FRIDAY NIGHT. A SHORTWAVE TROUGH
PASSING ACROSS THE GREAT LAKES MAY ALSO ENHANCE OUR POP ON FRIDAY
NIGHT BEFORE DRIER AIR FINALLY ARRIVES IN ITS WAKE.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 354 PM EDT THU SEP 11 2014
MID TERM MODELS ARE STILL IN GOOD AGREEMENT FOR THE UPPER LEVEL LONG
WAVE PATTERN. A CLOSED LOW WILL BE PASSING ALONG THE UPPER GREAT
LAKES AT THE START OF THE FORECAST PERIOD...QUICKLY MOVING EASTWARD
AND LOSING STRENGTH. MEANWHILE...AN UPPER LEVEL RIDGE ACROSS THE
SOUTHERN CONUS WILL KEEP A GOOD TRANSITION ZONE OVER THE OHIO RIVER
VALLEY WITH STRONG WRLY FLOW. THIS SHORTWAVE/CLOSED LOW WILL CAUSE A
DISTURBANCE AT THE SURFACE...WITH A STRONG AREA OF QVECTOR
CONVERGENCE EXPECTED TO MOVE ACROSS THE UPPER GREAT LAKES REGION AS
WELL BY THE START OF THE FORECAST PERIOD. KY WILL FIND ITSELF ON THE
SOUTHERN FRINGES OF THIS DISTURBANCE...EXITING AS WE HEAD INTO 12Z
SATURDAY. AS IT QUICKLY PUSHES OFF TO THE EAST DURING THE DAY...ANY
PRECIP CHANCES WILL CEASE ACROSS FAR SE KY BY LATE SAT AFTERNOON.
MODELS ARE CONTINUING TO SUPPORT A FASTER EXIT OF PRECIPITATION
COMPARED TO THAT OF PREVIOUS RUNS FOR DURING THE DAY SATURDAY. CUT
BACK POPS SLIGHTLY...WITH ALL RAIN EXITING KY BY 0Z SUNDAY. THE
BOUNDARY WILL BECOME STALLED OUT ONCE MORE TO OUR SOUTH...NEAR THE
ATLANTIC COAST. HOWEVER...WITH THE INFLUX OF MOISTURE FROM THE
ATLANTIC...DAYTIME INSTABILITY WILL HELP PRECIP CHANCES SPREAD
FARTHER NORTH...POSSIBLY MAKING IT TO THE FAR SE BORDER OF KY DURING
THE DAY SUNDAY. PREVIOUS FORECAST LEFT MENTION OF PRECIP OUT
ALONG THE BORDER. HOWEVER...LATEST MODEL RUNS ARE ALL IN VERY
GOOD AGREEMENT THAT POPS MOVE CLOSE ENOUGH TO OUR BORDER THAT
CONFIDENCE ERORRED ON THE SIDE AT LEAST INCLUDING SOME SLIGHT CHANCE
POPS FOR THE HIGH TERRAIN ALONG THE TN/VA BORDER. THE SAME APPLIES
FOR DURING THE DAY MONDAY....ALTHOUGH MODELS ARE GOOD AGREEMENT OF
THE PRECIP SPREADING FARTHER INTO THE CWA DURING THE DAY AS THE
BOUNDARY SHIFTS SLIGHTLY NORTHWARD.
MEANWHILE MONDAY...ANOTHER SHORTWAVE WILL DEVELOP IN THE LONGWAVE
PATTERN...DROPPING HEIGHTS SLIGHTLY ACROSS EASTERN KY AND BRINGING
YET ANOTHER QUICK MOVING BUT WEAK SURFACE COLD FRONT THAT WILL SWEEP
THROUGH KY LATE MONDAY NIGHT. ONCE AGAIN...ERN KY WILL FIND ITSELF
ON THE SOUTHERN FRINGES OF THIS DISTURBANCE...BUT THE BOUNDARY
SHOULD INTERACT ENOUGH WITH THE ONGOING PRECIP IN THE SE TO KEEP
POPS GOING THROUGHOUT MOST OF THE NIGHT MONDAY NIGHT AS WELL. STRONG
SUBSIDENCE WILL MOVE IN BEHIND THE FRONTAL BOUNDARY...WITH POPS
QUICKLY TAPERING OFF BY EARLY TUESDAY. WIDESPREAD CLOUD COVER WILL
ALSO ACCOMPANY THIS SYSTEM...SLOWLY CLEARING THROUGHOUT THE DAY
TUESDAY. HIGH PRESSURE...ONCE IN CONTROL...SHOULD STAY FOR THE
REMAINDER OF THE FORECAST PERIOD...WITH EASTERN KY FINALLY EXPECTED
TO HAVE A BREAK FROM THE PRECIP FROM TUESDAY THROUGH THURSDAY.
OVERALL...STRONG ZONAL FLOW ACROSS KY WILL KEEP TEMPERATURES
MODERATED IN THE MID 70S THROUGH MUCH OF THE EXTENDED FORECAST.
OVERNIGHT LOWS WILL BE CLOUD DEPENDENT. FOR THOSE NIGHTS WHEN
CLEARING IS EXPECTED...LOWS COULD DROP DOWN INTO THE CHILLY LOW TO
MID 50S. AND WHEN THERE IS CLOUD COVER INVOLVED...AS IS THE CASE IN
THE SE FOR MUCH OF THE EXTENDED...UPPER 50S AND LOW 60S WILL BE
THE RANGE TO LOOK FOR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 215 AM EDT FRI SEP 12 2014
IFR TO MVFR STRATUS WILL BE THE RULE ACROSS MOST OF EASTERN KENTUCKY
THROUGH THE PERIOD...ALTHOUGH A FEW PASSING AREAS OF LIGHT
RAIN/SHOWERS MAY IMPROVE CEILINGS TEMPORARILY. WINDS WILL REMAIN
OUT OF THE NORTH AND NORTHEAST AT AROUND 5 KTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...HAL
LONG TERM...JMW
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1253 AM EDT FRI SEP 12 2014
.UPDATE...
ISSUED AT 1252 AM EDT FRI SEP 12 2014
SPOTTY LIGHT RADAR RETURNS ARE SHOWING UP ACROSS LOCATIONS ALONG AND
SOUTH OF THE MOUNTAIN PARKWAY. THE LATEST HRRR TRENDS SUPPORT THE
CONTINUATION OF AT LEAST ISOLATED LIGHT RAIN/SHOWERS THROUGH DAWN...
AND GIVEN THE DEEP MOISTURE STILL IN PLACE...SEE NO REASON TO ARGUE.
HAVE EXPANDED THE ISOLATED POPS BACK TOWARDS THE I-64 CORRIDOR
THROUGH DAWN. THE REST OF THE FORECAST REMAINS ON TRACK.
UPDATE ISSUED AT 1039 PM EDT THU SEP 11 2014
UPDATED TO REMOVE THE HIGHER POPS FROM THE FORECAST AS RAIN SHOWERS
HAVE DIMINISHED ACROSS SOUTHEAST KENTUCKY. ISOLATED SHOWERS MAY STILL
BE POSSIBLE OVER THE NEXT HOUR...BUT WE SHOULD SEE A FAIRLY QUIET
SECOND HALF OF THE NIGHT. GIVEN THE PRESENCE OF THE WASHED OUT
BOUNDARY ACROSS OUR SOUTHERN AREAS...PLAN TO BRING SOME ISOLATED
SHOWERS BACK INTO THE FORECAST TOWARDS DAWN WITH THE ABUNDANCE OF
MOISTURE LOCATED ALONG THE FRONT. THIS COULD MANIFEST ITSELF MORE AS
DRIZZLE...BUT REGARDLESS...SOME POPS ARE WARRANTED.
OTHERWISE...HOURLY GRIDS SEEM PRETTY GOOD.
UPDATE ISSUED AT 727 PM EDT THU SEP 11 2014
UPDATED TO REMOVE THE LAST OF THE THUNDER. STILL WATCHING AN INTENSE
BAND OF SHOWERS AS THEY MOVE SOUTH ACROSS SOUTHEAST KENTUCKY. THESE
ARE PEGGED TO CLEAR THE SOUTHEAST COUNTIES BY 10 PM. THE REST OF THE
NIGHT SHOULD THEN FEATURE DRIER WEATHER. LOOKS LIKE STRATUS SHOULD
BUILD IN BEHIND THE STALLING COLD FRONT. IT IS POSSIBLE WE COULD SEE
A LITTLE DRIZZLE IF THE MOISTURE DEPTH CAN INCREASE ENOUGH. CERTAINLY
ENOUGH OF A THREAT TO LEAVE SOME SMALL POPS IN LATE TONIGHT. CLOUDS
WILL HOLD TOUGH THROUGH THE NIGHT AND MAY HOLD ON THROUGH MUCH OF THE
DAY TOMORROW AS WINDS TURN NORTH-NORTHEASTERLY...HELPING TO MAINTAIN
THE LOW CLOUDS. WITH THE CLOUDS...IT SHOULD HELP CUT DOWN ON THE FOG
POTENTIAL TONIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 400 PM EDT THU SEP 11 2014
A LINE OF CONVECTION DEVELOPED AND MOVED THROUGH SE KENTUCKY THIS
AFTERNOON. THE EFFECTIVE COLD FRONT APPEARS TO BE WITH THIS LINE. A
FEW SHOWERS HAVE DEVELOPED TO THE NW...BUT PRECIP HAS BEEN SPARSE.
MODELS HAVE NOT HANDLED THIS VERY WELL. IN LIGHT OF TRENDS...HAVE
GONE BELOW MODEL GUIDANCE FOR POPS OVER MUCH OF THE AREA FOR TONIGHT.
EVEN BEHIND THE FRONT...MOISTURE WILL LINGER...AND ADDITIONAL SHOWERS
CAN NOT BE RULED OUT ON FRIDAY OR FRIDAY NIGHT. A SHORTWAVE TROUGH
PASSING ACROSS THE GREAT LAKES MAY ALSO ENHANCE OUR POP ON FRIDAY
NIGHT BEFORE DRIER AIR FINALLY ARRIVES IN ITS WAKE.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 354 PM EDT THU SEP 11 2014
MID TERM MODELS ARE STILL IN GOOD AGREEMENT FOR THE UPPER LEVEL LONG
WAVE PATTERN. A CLOSED LOW WILL BE PASSING ALONG THE UPPER GREAT
LAKES AT THE START OF THE FORECAST PERIOD...QUICKLY MOVING EASTWARD
AND LOSING STRENGTH. MEANWHILE...AN UPPER LEVEL RIDGE ACROSS THE
SOUTHERN CONUS WILL KEEP A GOOD TRANSITION ZONE OVER THE OHIO RIVER
VALLEY WITH STRONG WRLY FLOW. THIS SHORTWAVE/CLOSED LOW WILL CAUSE A
DISTURBANCE AT THE SURFACE...WITH A STRONG AREA OF QVECTOR
CONVERGENCE EXPECTED TO MOVE ACROSS THE UPPER GREAT LAKES REGION AS
WELL BY THE START OF THE FORECAST PERIOD. KY WILL FIND ITSELF ON THE
SOUTHERN FRINGES OF THIS DISTURBANCE...EXITING AS WE HEAD INTO 12Z
SATURDAY. AS IT QUICKLY PUSHES OFF TO THE EAST DURING THE DAY...ANY
PRECIP CHANCES WILL CEASE ACROSS FAR SE KY BY LATE SAT AFTERNOON.
MODELS ARE CONTINUING TO SUPPORT A FASTER EXIT OF PRECIPITATION
COMPARED TO THAT OF PREVIOUS RUNS FOR DURING THE DAY SATURDAY. CUT
BACK POPS SLIGHTLY...WITH ALL RAIN EXITING KY BY 0Z SUNDAY. THE
BOUNDARY WILL BECOME STALLED OUT ONCE MORE TO OUR SOUTH...NEAR THE
ATLANTIC COAST. HOWEVER...WITH THE INFLUX OF MOISTURE FROM THE
ATLANTIC...DAYTIME INSTABILITY WILL HELP PRECIP CHANCES SPREAD
FARTHER NORTH...POSSIBLY MAKING IT TO THE FAR SE BORDER OF KY DURING
THE DAY SUNDAY. PREVIOUS FORECAST LEFT MENTION OF PRECIP OUT
ALONG THE BORDER. HOWEVER...LATEST MODEL RUNS ARE ALL IN VERY
GOOD AGREEMENT THAT POPS MOVE CLOSE ENOUGH TO OUR BORDER THAT
CONFIDENCE ERRED ON THE SIDE AT LEAST INCLUDING SOME SLIGHT CHANCE
POPS FOR THE HIGH TERRAIN ALONG THE TN/VA BORDER. THE SAME APPLIES
FOR DURING THE DAY MONDAY....ALTHOUGH MODELS ARE GOOD AGREEMENT OF
THE PRECIP SPREADING FARTHER INTO THE CWA DURING THE DAY AS THE
BOUNDARY SHIFTS SLIGHTLY NORTHWARD.
MEANWHILE MONDAY...ANOTHER SHORTWAVE WILL DEVELOP IN THE LONGWAVE
PATTERN...DROPPING HEIGHTS SLIGHTLY ACROSS EASTERN KY AND BRINGING
YET ANOTHER QUICK MOVING BUT WEAK SURFACE COLD FRONT THAT WILL SWEEP
THROUGH KY LATE MONDAY NIGHT. ONCE AGAIN...ERN KY WILL FIND ITSELF
ON THE SOUTHERN FRINGES OF THIS DISTURBANCE...BUT THE BOUNDARY
SHOULD INTERACT ENOUGH WITH THE ONGOING PRECIP IN THE SE TO KEEP
POPS GOING THROUGHOUT MOST OF THE NIGHT MONDAY NIGHT AS WELL. STRONG
SUBSIDENCE WILL MOVE IN BEHIND THE FRONTAL BOUNDARY...WITH POPS
QUICKLY TAPERING OFF BY EARLY TUESDAY. WIDESPREAD CLOUD COVER WILL
ALSO ACCOMPANY THIS SYSTEM...SLOWLY CLEARING THROUGHOUT THE DAY
TUESDAY. HIGH PRESSURE...ONCE IN CONTROL...SHOULD STAY FOR THE
REMAINDER OF THE FORECAST PERIOD...WITH EASTERN KY FINALLY EXPECTED
TO HAVE A BREAK FROM THE PRECIP FROM TUESDAY THROUGH THURSDAY.
OVERALL...STRONG ZONAL FLOW ACROSS KY WILL KEEP TEMPERATURES
MODERATED IN THE MID 70S THROUGH MUCH OF THE EXTENDED FORECAST.
OVERNIGHT LOWS WILL BE CLOUD DEPENDENT. FOR THOSE NIGHTS WHEN
CLEARING IS EXPECTED...LOWS COULD DROP DOWN INTO THE CHILLY LOW TO
MID 50S. AND WHEN THERE IS CLOUD COVER INVOLVED...AS IS THE CASE IN
THE SE FOR MUCH OF THE EXTENDED...UPPER 50S AND LOW 60S WILL BE
RANGE TO LOOK FOR.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 727 PM EDT THU SEP 11 2014
LOW CLOUDS WILL CONTINUE TO SPREAD SOUTH INTO EASTERN KENTUCKY BEHIND
A DEPARTING COLD FRONT. THIS WILL SET THE STAGE FOR IFR TO MVFR CIGS
THROUGH THE OVERNIGHT HOURS. BY LATE TONIGHT...MOST AREAS SHOULD BE
IFR OR VERY LOW MVFR. SOME GRADUAL IMPROVEMENT WILL BE SEEN AS WE
HEAD THROUGH THE DAYLIGHT HOURS TOMORROW...BUT WE WILL STRUGGLE TO
GET OUT OF THE MVFR CATEGORY. WINDS WILL REMAIN LIGHT OUT OF THE
NORTH TO NORTHEAST.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...HAL
LONG TERM...JMW
AVIATION...KAS
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1121 PM CDT Thu Sep 11 2014
.UPDATE:
Issued at 950 PM CDT Thu Sep 11 2014
Grids have been updated to add patchy drizzle late tonight and
tomorrow morning.
Kanofsky
&&
.SHORT TERM: (Through Late Tonight)
Issued at 252 PM CDT Thu Sep 11 2014
Clouds have not cleared out this afternoon even though high
pressure has begun to build into the low levels. This is because
of persistent low level inversion that the RAP is showing around
900mb. Moisture is being trapped below this inversion, so expect
these clouds to persist into the night. Drizzle may redevelop over
the area toward morning. Temperatures did not climb much today and
do not have far to fall tonight to reach agreeable MOS guidance
for lows.
Britt
.LONG TERM: (Friday through Next Thursday)
Issued at 252 PM CDT Thu Sep 11 2014
Next shortwave to continue sliding southeast into forecast area on
Friday. Models in good agreement on timing and precipitation
associated with it. Will see isolated/widely scattered showers
develop and spread southeast across forecast area during the day
on Friday exiting late Friday evening. QPF amounts will be rather
light with best chances along and north of I-70. As for
temperatures, to remain well below normal with highs only in the
upper 50s to upper 60s. Lows Friday night will be in the low 40s
to low 50s.
Then on Saturday, strong ridge of high pressure to build in and
skies to clear out. Despite the sunshine, it will continue to feel
like fall with high temperatures only in the 60s and lows Saturday
night in the 40s.
By Sunday, surface ridge begins to move off to the east allowing
temperatures to slowly moderate. Highs will be in the upper 60s to
low 70s. Then Sunday night the next weather system to approach the
region with showers developing and spread southeast through region
Sunday night through Monday night. Frontal boundary to stall out
just south of forecast area early Tuesday morning with weak surface
ridging building in. Could see some lingering isolated/scattered
showers through Wednesday night for western and southern portions of
the area. As for temperatures, highs will be in the 70s and lows in
the 50s through next Thursday.
Byrd
&&
.AVIATION: (For the 06z TAFs through 06z Friday Night)
Issued at 1110 PM CDT Thu Sep 11 2014
Stratus remains widespread late this evening producing MVFR flight
conditions at all the terminals. There is however some drier air
slowly advecting southwestward due to northeasterly low level
winds. This has brought a jagged clearing line into far northern
MO which then curves back into far northern IL. There is potential
that KUIN could clear out for a time only to have clouds move back
in - confidence is low on the trends. I have also added a prob30
for light rain in the afternoon as an upper trof digs across the
upper MS valley. Elsewhere the aforementioned dry air has lessened
my confidence in the previously anticipated lower cigs overnight
and threat of drizzle. I have maintained it in the new TAFS
although with higher cigs and only a TEMPO group. Clearing should
commence at all sites Friday night, some of which is beyond the
valid forecast period.
Specifics for KSTL:
Stratus remains widespread late this evening producing MVFR flight
conditions. There is however some drier air slowly advecting
southwestward due to northeasterly low level winds. This could
could initially result in the cig height bouncing from 1800-2000
ft. The dry air has also lessened my confidence in the previously
anticipated lower cigs overnight and threat of drizzle. I have
maintained it in the new TAFS although with higher cigs and only a
TEMPO group. Otherwise MVFR flight conditions will persist on
Friday with with clearing late on Friday night.
Glass
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS TULSA OK
1152 PM CDT THU SEP 11 2014
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
MVFR CEILINGS ARE EXPECTED TO REMAIN ACROSS THE REGION THROUGH THE
MAJORITY OF THE TAF PERIOD. PERIODS OF IFR CONDITIONS LOOK TO BE
POSSIBLE LATE TONIGHT/EARLY FRIDAY MORNING OVER SOUTHEAST
OKLAHOMA AND NORTHWEST ARKANSAS AS CHANCES FOR SHOWERS AND
THUNDERSTORMS SPREAD NORTHWARD. SOME AREAS OF LIGHT DRIZZLE/RAIN
COULD ALSO BE POSSIBLE OVER PARTS OF NORTHEAST OKLAHOMA WHICH
COULD CREATE AREAS OF IFR CEILINGS. GREATER PRECIP CHANCES LOOK
TO BE MAINLY OVER SOUTHEAST OKLAHOMA INTO WEST CENTRAL ARKANSAS
INTO THE AFTERNOON HOURS.
&&
.PREV DISCUSSION... /ISSUED 929 PM CDT THU SEP 11 2014/
DISCUSSION...
REGIONAL SFC ANALYSIS SHOWS FRONTAL BOUNDARY STALLED NEAR/SOUTH OF
I-20 IN TEXAS WITH A SECOND...STRONGER SURGE OF COLD AIR SLIDING
DOWN THE FRONT RANGE OF THE ROCKIES. THUS FAR NO PRECIP IN THE
AREA BUT LATER TONIGHT IN RESPONSE TO MID LEVEL WAVE DIVING
THROUGH CENTRAL ROCKIES...EXPECT LIFT TO INCREASE NORTH OF THE
STALLED BOUNDARY RESULTING IN INCREASING COVERAGE OF SHOWERS
MAINLY ALONG AND SOUTH OF I-40 TOWARD MORNING. BOTH HRRR AND LOCAL
WRF HAVE REMAINED CONSISTENT IN DEPICTING THIS SCENARIO WITH
ELEVATED INSTABILITY ALSO INCREASING. THUS WILL KEEP THE HIGHER
CHANCES OF SHOWERS LATE TONIGHT IN SOUTHERN AREAS...ONLY REAL
CHANGE TO FORECAST WAS TO TAKE OUT MOST PRECIP THROUGH 06Z. TEMPS
FALLING SLOWLY UNDER LOW CLOUD DECK WHICH WILL HOLD FIRM...HOWEVER
SECOND SURGE OF COLDER AIR LIKELY WILL DROP AREAS NEAR KS BORDER
INTO THE 50S BY MORNING. NO ADDITIONAL UPDATES AT THIS TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 60 68 51 72 / 20 50 20 10
FSM 65 71 57 74 / 50 50 30 10
MLC 65 69 55 72 / 50 60 30 10
BVO 56 66 46 70 / 10 50 20 0
FYV 58 66 50 69 / 20 40 30 10
BYV 57 67 50 68 / 20 40 30 10
MKO 62 67 52 71 / 30 50 30 10
MIO 56 67 47 69 / 10 30 20 0
F10 61 68 52 71 / 30 50 30 10
HHW 68 73 60 75 / 70 70 40 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...20
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1115 PM CDT THU SEP 11 2014
.AVIATION...
MVFR CIGS ARE FILTERING SOUTH INTO METROPLEX NOW...AND GFS/NAM
MOS SHOW IFR NEAR SUNRISE. THIS IS LIKELY DUE TO COLUMN
SATURATION AS THE WARM ADVECTION SHRA/TSRA DEVELOP IN THE EARLY
MORNING. HAVE PRETTY MUCH CONTINUED WITH PREVIOUS TAF/S OVERNIGHT
PRECIP SCENARIO. RAIN STILL APPEARS TO BE MORE LIKELY NORTH OF
THE METROPLEX AND HAVE CONTINUED THE SHRA WITH VCTS RATHER THAN
HITTING PRECIP HARDER.
THE STRONG COLD ADVECTION DURING THE DAY FRIDAY WILL KEEP
CEILINGS FROM LIFTING ABOVE 020 AND HAVE LOWERED CEILINGS NOW FOR
THE ENTIRE DAY. NORTH WINDS WILL PICK UP IN THE MORNING REACHING
THE HIGH TEENS WITH GUSTS INTO THE MID 20S.
COLD ADVECTION WILL ALSO AFFECT WACO...HOLDING IN LOWER CEILINGS.
I DO NOT EXPECT AFTERNOON STORMS THERE (THEY SHOULD BE FARTHER
SOUTH) DUE TO THE STABILIZING EFFECTS OF THE COLD ADVECTION. 84
&&
.UPDATE...
A POTENT UPPER TROUGH IS NOW SWINGING INTO THE NORTHERN PLAINS
AND AN UNSEASONABLY COLD AIR MASS HAS INVADED MUCH OF THE GREAT
PLAINS REGION. TEMPERATURES IN THE 40S EXTEND AS FAR SOUTH AS NW
KANSAS WITH READINGS IN THE 30S FARTHER NORTHWEST NEAR THE CORE OF
A 1035 MB HIGH PRESSURE CELL. AGAIN THIS IS UNUSUALLY COLD FOR
THIS TIME OF DAY IN EARLY TO MID SEPTEMBER. THE SURFACE HIGH WILL
CONTINUE TO DROP SOUTHEAST AND SEND A REINFORCING SURGE OF COLD
AIR SOUTH IN THE REGION BY MORNING. NORTH WINDS WILL INCREASE
DURING THE DAY...LIKELY INTO THE 15 TO 20 MPH RANGE BY MID-LATE
AFTERNOON. FORECASTED HIGH TEMPS FOR TOMORROW LOOK GOOD...BUT DUE
TO THE STRONG COLD ADVECTION...DID UPDATE TO SHOW FALLING
TEMPERATURES DURING THE AFTERNOON HOURS BEHIND THE FRONT. IT
CERTAINLY WILL FEEL FALL-LIKE TOMORROW. ALSO LOWERED LOW TEMPS
FRIDAY NIGHT A FEW DEGREES ACROSS THE WESTERN AND CENTRAL ZONES IN
ACCORDANCE WITH THE WRF FORECASTS...WHICH ARE USUALLY SUPERIOR
WITH TEMPS IN THIS PATTERN.
AS FAR AS RAIN CHANCES GO...WE ARE IN A LULL THIS EVENING AS
EXPECTED...BUT ALL GUIDANCE CONTINUES TO ADVERTISE AN INCREASE IN
ISENTROPIC ASCENT NEAR 700-850MB WHERE PARCELS ARE CONVECTIVELY
UNSTABLE. MOST OF THIS ELEVATED CONVECTION WILL FORM PRIMARILY
NORTHEAST OF A BOWIE TO DFW TO CORSICANA LINE AFTER MIDNIGHT
WHERE THE ISENTROPIC LIFT...MOISTURE AND INSTABILITY ALL ALIGN
BEST. WHEN THE REINFORCING COLD FRONT ARRIVES AFTER
SUNRISE...FRONTOGENETIC FORCING WILL RAMP UP AND AID IN ADDITIONAL
LIFT WITH A BAND OF RAIN/STORMS FORMING ROUGHLY ALONG A COMANCHE
TO DFW TO PARIS LINE BY MID MORNING. THIS ACTIVITY WILL GRADUALLY
WORK/DEVELOP SOUTHEASTWARD DURING THE DAY...BUT LIKELY WILL NOT
MAINTAIN A SOLID/CONTINUOUS LINE AS IT DOES SO. ALL IN ALL NO
CHANGE TO THE PRECIP FORECAST WAS REQUIRED.
TR.92
&&
.PREV DISCUSSION... /ISSUED 321 PM CDT THU SEP 11 2014/
PLENTY OF CHALLENGES THIS FORECAST PACKAGE AS WE TRACK A SLOW-
MOVING FRONT NOW EXTENDING FROM A GATESVILLE...TO CORSICANA...TO
CANTON LINE. A BROKEN LINE OF SHOWERS AND THUNDERSTORMS CONTAINING
LOCALLY HEAVY RAINFALL HAS ERUPTED IN THE PAST 1-2 HOURS ALONG THE
BOUNDARY. IN ADDITION...LOCALIZED FLOODING ISSUES WILL NEED TO BE
MONITORED ALONG THE COLD FRONT WITH THIS BROKEN LINE OF STORMS
WITH RICH PRECIPITABLE WATER VALUES WELL ABOVE 2 INCHES AND HIGH
THETA-E AIR BETWEEN 700-850MB. ANY TRAINING ACTIVITY WILL LIKELY
CAUSE SOME LOCALIZED HYDROLOGIC PROBLEMS. WE WILL CARRY THE HIGHEST
RAIN CHANCES THIS EVENING ALONG AND AHEAD OF THE FRONT OR ACROSS
THE SOUTHEAST HALF OF THE REGION. THE BEST INSTABILITY AND FORCING
WITH THE COLD FRONT WILL MOST LIKELY DRIVE THIS ACTIVITY THROUGH
NIGHTFALL. IN ADDITION...WE HAVE ADDED HIGHER CHANCES ACROSS THE
FAR WESTERN COUNTIES FOR LATE EVENING. THE APPROACH OF A SUBTLE
DISTURBANCE OVER WEST TEXAS WILL LIKELY PROVIDE ENOUGH LIFT TO
SUSTAIN A FEW SHOWER OR STORMS ACROSS THE FAR WESTERN COUNTIES
AFTER SUNSET.
THE WEST TEXAS DISTURBANCE WILL CONTINUE TO MOVE OVER THE RED RIVER
AREA AND SOUTHERN OKLAHOMA TONIGHT. NORTHERN AREAS...ESPECIALLY
THOSE ALONG AND NORTH OF I-20 WILL BE UNDERNEATH THE RIGHT ENTRANCE
REGION OF A 60-70KT JET STREAK STREAMING OVER OKLAHOMA. AS WE HEAD
INTO FRIDAY MORNING...A STRONGER DISTURBANCE CURRENTLY OVER WYOMING
WILL ROTATE SOUTHEAST OVER THE KANSAS/NEBRASKA BORDER AND SHOULD
SHUNT THE JET STREAK A LITTLE FURTHER SOUTH. THE COMBINATION OF
THESE FEATURES WILL PROVIDE THE SYNOPTIC LIFT...WHILE NOCTURNAL
LOW LEVEL WARM ADVECTION OVERRIDES THE SHALLOW FRONTAL INVERSION.
WITH THE FOCUS SHIFTING BACK NORTH...WILL MAINTAIN LIKELY CHANCES
FOR RAINFALL WHICH AT TIMES COULD BE LOCALLY HEAVY...BUT NOT ENOUGH
ALONG WITH ANTECEDENT DRY SOIL CONDITIONS TO ISSUE ANY FLOOD WATCHES
AT THIS POINT. 500-700MB LAPSE RATES WILL BE HOVERING AROUND 6 DEG/KM
WITH BOTH RUC AND NAM12 BUFKIT SOUNDINGS INDICATING A DEEP...BUT
SKINNY LAYER OF CAPE. ALL TOLD...SHOWERS WILL BE LIKELY OVERNIGHT
TONIGHT INTO FRIDAY MORNING ACROSS THESE AREAS WITH EMBEDDED/ELEVATED
THUNDERSTORMS AT TIMES. RAIN CHANCES AFTER NIGHTFALL ACROSS CENTRAL
TEXAS SHOULD DIMINISH TO LOWER CHANCES THAN WHAT WILL BE SEEN
ACROSS THE NORTH. THERE WILL BE QUITE A VARIANCE ON HIGH TEMPERATURES
FROM NORTHWEST TO SOUTHEAST FRIDAY. HIGHS WILL ONLY PUSH TO AROUND
70 DEGREES ACROSS THE FAR NORTHWEST... TO THE LOWER 90S ACROSS THE
FAR SOUTHEAST.
BETTER RAIN CHANCES SHIFT BACK OVER CENTRAL TEXAS ONCE AGAIN
FRIDAY AFTERNOON INTO SATURDAY MORNING. THE PASSAGE OF THE STRONG
SHORTWAVE TO THE NORTH TOWARD NORTHERN MISSOURI AND IOWA WILL HELP
SEND A STRONGER AND DEEPER PUSH OF COOLER AIR INTO THE NORTHERN
COUNTIES WITH THE SOUTH REMAINING WARMER AND MORE UNSTABLE. THE
UPPER HIGH WILL STRENGTHEN SOME BACK OVER THE AREA THIS WEEKEND
WITH JUST LINGERING LOW RAIN CHANCES ACROSS CENTRAL TEXAS WHERE
DEEPER MOISTURE WILL LINGER. THESE CHANCES SHOULD END BY NIGHTFALL
SATURDAY EVENING AS THE ATMOSPHERE STABILIZES. EVEN SO...CLOUD
COVER ON AND ABOVE THE DEEPENING FRONTAL INVERSION WILL MAINTAIN
CONSIDERABLE CLOUDINESS ACROSS THE REGION. THE CLOUDS COMBINED
WITH THE COOLER AIRMASS WILL HOLD HIGHS BETWEEN 75 AND 85 DEGREES
SATURDAY THAT WILL SLOWLY MODIFY TO THE 80S ON SUNDAY.
THE FORECAST AFTER THE WEEKEND BECOMES CHALLENGING ONCE AGAIN AS
WE MONITOR AN UPPER DISTURBANCE ROTATING AROUND THE WESTERN PERIPHERY
OF THE UPPER HIGH OVER THE WESTERN GULF COAST ON MONDAY. BY MONDAY
NIGHT AND TUESDAY...ANOTHER STRONG DISTURBANCE WILL MOVE DOWN
WITHIN NORTHWEST FLOW ALOFT ACROSS THE CENTRAL PLAINS AND DRAG A
SECOND COLD FRONT INTO SOUTHERN PLAINS BY TUESDAY. MOISTURE WILL
BE PLENTIFUL ENOUGH THAT WE HAVE MAINTAINED THE LOW CHANCES FOR
SHOWERS AND STORMS UNTIL TIMING AND ENVIRONMENTAL DETAILS BECOME
CLEARER FOR THAT TIME FRAME AND WE CAN DIAGNOSE WHEN THE BEST
CHANCES WILL OCCUR. THE LATTER HALF OF NEXT WEEK WAS KEPT DRY AND
WARM FOR NOW...AS THE SECOND FRONT WASHES OUT OVER THE SOUTHERN
PART OF THE STATE. HOWEVER...LOW RAIN CHANCES MAY NEED TO BE
EXTENDED ACROSS OUR CENTRAL TEXAS COUNTIES IF THE FRONT STALLS
FURTHER NORTH. HIGH TEMPERATURES WILL MODIFY BACK TO THE MID AND
UPPER 80S WITH A FEW READINGS IN THE LOWER 90S POSSIBLE ACROSS OUR
CENTRAL TEXAS COUNTIES.
05/
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 73 75 60 77 66 / 70 70 20 10 10
WACO, TX 73 84 63 79 65 / 40 50 40 30 10
PARIS, TX 71 72 59 75 62 / 70 70 20 10 10
DENTON, TX 70 72 58 77 64 / 70 70 20 10 10
MCKINNEY, TX 70 73 58 75 63 / 70 70 20 10 10
DALLAS, TX 73 76 60 76 67 / 60 70 20 10 10
TERRELL, TX 73 79 61 76 64 / 60 70 30 10 10
CORSICANA, TX 74 83 63 79 65 / 40 50 40 20 10
TEMPLE, TX 72 88 63 78 65 / 20 60 50 30 20
MINERAL WELLS, TX 69 72 57 75 63 / 70 70 20 10 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1000 AM EDT FRI SEP 12 2014
.DISCUSSION...
.UPDATE...WEAK SFC LOW MOVED ONSHORE EARLY THIS MORNING WITH A
1012.3 MB SFC PRESSURE READING AT WEST PALM BEACH AT 5 AM. AT 9
AM...THE SFC LOW HAD MOVED INLAND SOUTH OF LAKE OKEECHOBEE AND
SHOULD CONTINUE TO MOVE SLOWLY W/WSW. A CONVERGENT BAND OF SCATTERED
SHOWERS HAD AFFECTED VOLUSIA COUNTY AROUND SUNRISE BUT THAT ACTIVITY
HAS RECENTLY DIMINISHED. MORNING CAPE SOUNDING AT 10Z INDICATED DEEP
MOISTURE WITH PRECIPITABLE WATER VALUE OF 2.15 WITH DEEP LAYER NE
FLOW IN THE MID TO UPPER LEVELS. UPSTREAM SOUNDING AT JAX WAS MUCH
DRIER WITH A PWAT OF 1.66 AND SUBSTANTIAL DRY LAYER ABOVE 600 MBS.
06Z GFS HAS THE LOW LVL CIRCULATION IN THE H9-H8 LAYER SHIFTING
WESTWARD TOWARD FT MYERS BY THIS EVENING WITH LOW TO MID LVL FLOW
BECOMING SE INTO THIS AFTERNOON ACROSS E CENTRAL FL. NORMALLY THIS
WOULD BE A FAVORABLE ENVIRONMENT ON THE ASCENDANT SIDE OF THE LOW
LVL CIRCULATION TO SEE A HIGH COVERAGE OF AFTERNOON STORMS WITH
ADEQUATE DEEP MOISTURE. A CLOSER LOOK AT GFS MODEL MEAN RH FIELDS
SHOWS DECREASING MOISTURE IN THE 700-300 MB LAYER ACROSS OUR SRN
AREAS THIS AFTERNOON AND HRRR INDICATES A LACK OF DEEP CONVECTION
DEVELOPING ACROSS MUCH E CENTRAL FL THIS AFTERNOON WITH MAINLY
SHOWER ACTIVITY. WILL STILL FAVOR SRN INTERIOR SECTIONS FOR HIGHEST
AFTERNOON SHOWERS/THUNDERSTORM CHANCES CLOSER TO THE SFC LOW
PRESSURE AREA AND WHERE LOW LVL CONVERGENCE SHOULD BE MAXIMIZED AS
DIFFUSE EAST COAST SEA BREEZE SHOULD MOVE INLAND LATE THIS AFTN.
HIGHS WILL AVERAGE IN THE UPPER 80S ALONG THE EAST COAST TO AROUND
90/LOWER 90S OVER THE INTERIOR.
&&
.AVIATION...
CHC FOR TSRA DEVELOPMENT LOWER THAN NORMAL FOR TERMINALS WITH HIGHER
CHANCE OF AFTERNOON CONVECTIVE COVERAGE SOUTH OF KISM TO AROUND KOBE
VCNTY AND MAINLY INLAND FROM SRN CSTL TERMINALS FROM KVRB-KSUA. VCSH
IN AT MOST TERMINALS INTO THIS AFTN WITH SCT SHRA AND ISOLATED TSRA
DEVELOPMENT ACROSS E CENTRAL FL INTO MID-LATE AFTN AS SFC LOW PRES
AREA MOVES WESTWARD ACROSS THE SRN PENINSULA. BRIEF MVFR/CIGS VSBY
MAY OCCUR WITH CONVECTION THIS AFTERNOON...MAINLY AFT 18Z.
&&
.MARINE...
E-SE WINDS TO 10-15 KNOTS WILL VEER TO THE SE BY LATE AFTERNOON. SEAS
MAINLY 3 FT NEARSHORE TO 3-4 FT OFFSHORE TODAY WITH SHORTER PERIOD
WIND WAVE THE PRIMARY COMPONENT.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
VOLKMER/SEDLOCK
AREA FORECAST DISCUSSION
NWS MIAMI FL
833 AM EDT FRI SEP 12 2014
.AVIATION...
TROPICAL RAIN SHOWERS WITH EMBEDDED THUNDER ARE MOVING SSW THROUGH
SOUTH FLORIDA. THE HEAVIEST RAIN IS MOSTLY WEST OF THE TERMINALS
AT THIS HOUR, WITH LINES OF SHOWERS WITH SOME STORMS MOVING NORTH
ACROSS THE ATLANTIC WATERS DUE TO FLOW AROUND LOW PRESSURE. AS
THE AREA OF LOW PRESSURE MOVES SW, WHICH IS NOW JUST SW OF KPBI,
SHOWERS AND STORMS WILL LIKELY REDEVELOP ALONG THE COAST THIS
AFTERNOON ESPECIALLY WITH BREAKS IN THE CLOUDINESS ADDING TO THE
INSTABILITY. ALTHOUGH POPS ARE HIGH, PINPOINTING THUNDER IS MORE
TRICKY, SO MAY NEED TO WAIT A WHILE BEFORE INSERTING TEMPO GROUPS
FOR THIS AFTERNOON. DESPITE ABUNDANT MOISTURE, CONVERGENCE AND
NEARBY H5 DISTURBANCE, HRRR IS RATHER DRY THIS AFTERNOON, WHICH
REDUCES CONFIDENCE. 1K FT CIG THIS EARLY MORNING AT KPBI MAY
BRIEFLY FALL TO IFR, BEFORE IMPROVEMENT LATER THIS MORNING.
&&
.PREV DISCUSSION... /ISSUED 445 AM EDT FRI SEP 12 2014/
DISCUSSION...
VERY HEAVY RAIN IS FALLING ACROSS INLAND PALM BEACH COUNTY EARLY
THIS MORNING. THE AREA OF LOW PRESSURE MAY HAVE REDEVELOPED NEAR
THE COAST JUST OFF OF PALM BEACH COUNTY. AN MCV FEATURE DEVELOPED
OVER EASTERN PALM BEACH COUNTY VERY EARLY THIS MORNING TO THE
SOUTHWEST OF THE AREA OF LOW PRESSURE...WITH EXPANDING CLOUD TOPS
AS COLD AS -75C. THIS FEATURE HAS BEEN MOVING SLOWLY TOWARDS THE
WEST SOUTHWEST...WITH 2-3 INCH PER HOUR RAINFALL RATES. MORE
RECENTLY...THE HEAVIEST RAIN HAS BEEN WEAKENING IN INTENSITY AND
CLOUD TOPS HAVE BEGUN TO WARM. THE NORTH TO NORTHEASTERLY SHEAR
WILL PUSH THE HEAVIEST RAIN TO THE SOUTHWEST OF THE AREA OF LOW
PRESSURE...AND THE HEAVY RAIN MAY MOVES TOWARDS THE NAPLES REGION
LATER THIS MORNING IF IT HOLDS TOGETHER. LOCALLY HEAVY RAIN AND
FLOODING IS POSSIBLE...AND AN ISOLATED TORNADO CANNOT BE RULED
OUT.
FOR THE EAST COAST...POPS MAY BE A LITTLE TOO HIGH DUE TO THE
CLOUD COVER AND STORMS BEING PUSHED TO THE SOUTHWEST OF THE AREA
OF LOW PRESSURE. HOWEVER...STORMS COULD REDEVELOP AND FOCUS OVER
THE EAST COAST THIS AFTERNOON...AND MOST AREAS WILL SEE AT LEAST
LIGHT RAIN THIS MORNING. SO KEPT LIKELY POPS ACROSS THE
BOARD...BUT AMOUNTS ARE UNCERTAIN AT THIS TIME. FOR
TEMPERATURES...MOST LOCATIONS WILL REACH THE LOW/MID 80S...WITH
RAIN COOLED LOCATIONS REMAINING IN THE 70S.
THE AREA OF LOW PRESSURE/MCV WILL MOVE WEST SOUTHWEST ACROSS THE
REGION THROUGH THE DAY...AND EXIT INTO THE GULF OF MEXICO TONIGHT.
THE MODELS STILL DIFFER ON THE LOCATION OF THE LOW AND RAINFALL
CHANCES ACROSS THE REGION OVERNIGHT. THE ECMWF IS MUCH WETTER THAN
THE GFS...KEEPING DEEPER MOISTURE AND MORE SOUTHERLY FLOW ACROSS
SOUTH FLORIDA. KEPT WITH THE WETTER SOLUTION FOR THE SOUTHERN
PORTIONS OF THE REGION AND THE COASTAL AREAS OVERNIGHT.
SATURDAY...RIDGE OF HIGH PRESSURE WILL BUILD OVER THE WESTERN
ATLANTIC TO THE NORTHEAST OF THE REGION ON SATURDAY. THE AREA OF
LOW PRESSURE WILL CONTINUE WESTWARD INTO THE SOUTH CENTRAL GULF.
SOUTHEAST FLOW AND DEEP MOISTURE IS FORECAST TO CONTINUE...AND
RAIN CHANCES WILL CONTINUE IN THE 50-70 PERCENT RANGE...HIGHEST
ACROSS THE GULF COAST.
SUNDAY...DIFFERENCES STILL REMAIN IN THE MODELS ON SUNDAY. THE GFS
IS MUCH FASTER WITH THE AREA OF LOW PRESSURE OVER THE GULF.
THUS...THE REGION WOULD RETURN TO A MORE TYPICAL EASTERLY FLOW
REGIME...WITH SCATTERED STORMS DEVELOPING INLAND OF THE EAST COAST
AND THEN PUSHING TOWARDS THE GULF COAST IN THE AFTERNOON. THE
ECMWF IS MORE THAN 2 DEGREES TO THE EAST. THE ECMWF KEEPS THE
MOISTURE AXIS ACROSS SOUTH FLORIDA FROM THE AREA OF LOW PRESSURE
OVER THE GULF...WITH A LIGHT SOUTHERLY FLOW ACROSS THE REGION.
RAIN CHANCES WOULD THEN REMAIN VERY HIGH ACROSS MOST OF THE
REGION. FOR NOW KEPT SCATTERED POPS ALONG THE EAST COAST AND
LIKELY ACROSS THE INTERIOR AND GULF.
EARLY TO MIDDLE OF NEXT WEEK...AN UPPER TROUGH IS FORECAST TO DIG
ACROSS THE EASTERN CONUS AND INTO THE SOUTHEAST THE EARLY TO MIDDLE
PART OF THE WEEK. THE ECMWF IS DEEPER WITH THE TROUGH AND PUSHES A
COLD FRONT INTO SOUTHERN GEORGIA BY THE MIDDLE OF THE WEEK. THE
ECMWF PUSHES THE RIDGE AXIS OVER THE REGION ON MONDAY AND THEN
SOUTH OF THE REGION BY THE MIDDLE OF THE WEEK...WITH WEST TO
SOUTHWESTERLY FLOW. THIS WOULD FAVOR HIGHER RAIN CHANCES FOR THE
EAST AND NORTHEAST METRO AREAS.
AVIATION...
A WEAK AREA OF LOW PRESSURE CENTERED AROUND THE PALM BEACH COAST
WILL CONTINUE WESTWARD TOWARD THE GULF COAST THROUGH THE PERIOD.
PERIODS OF HEAVY RAINFALL WILL REMAIN IN THE FORECAST ACROSS THE
SOUTH FLORIDA REGION THROUGH THIS TIME. WINDS OVER THE EAST COAST
TAF SITES WILL SHIFT TO THE SOUTHEAST SOMETIME THROUGH THE
AFTERNOON HOURS TODAY AS THE LOW CONTINUES WESTWARD. WINDS AT
NAPLES WILL REMAIN LIGHT AND VARIABLE THROUGH THE PERIOD AS
UNCERTAINTY REGARDING THE EXACT TRACK OF THE LOW RELATIVE TO THE
APF TERMINAL REMAINS HIGH AT THIS TIME. AS THE LOW SHIFTS WESTWARD
OFF OF THE NAPLES COAST...LIGHT TO MODERATE SE WINDS WILL RETURN
ACROSS THE AREA. /85
MARINE...
A WEAK AREA OF LOW PRESSURE NEAR THE PALM BEACH COAST EARLY THIS
MORNING WILL MOVE ACROSS SOUTH FLORIDA TODAY...AND THEN INTO THE
REGIONAL GULF WATERS TONIGHT. RAIN CHANCES WILL REMAIN HIGH OVER
THE ATLANTIC AND GULF WATERS TODAY INTO THE WEEKEND. THE NHC IS
MONITORING THIS AREA OF LOW PRESSURE...AND THERE IS A MEDIUM
CHANCE OF DEVELOPMENT ONCE IT MOVES INTO THE GULF OF MEXICO. THIS
COULD IMPACT THE GULF FORECAST OVER THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 87 76 88 76 / 70 40 50 40
FORT LAUDERDALE 85 77 89 77 / 70 40 60 40
MIAMI 85 77 89 77 / 70 40 60 40
NAPLES 86 73 89 74 / 70 50 70 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...84/AK
LONG TERM....84/AK
AVIATION...21/KM
AREA FORECAST DISCUSSION
NWS DES MOINES IA
652 AM CDT FRI SEP 12 2014
.SHORT TERM /TODAY/...
ISSUED AT 333 AM CDT FRI SEP 12 2014
PRECIP AND TEMP TRENDS WILL BE THE PRIMARY CONCERNS TODAY. RIGHT
ENTRANCE REGION DIVERGENCE OF STRONG 120KT JET FROM MO VALLEY INTO
SERN CANADA CONTINUES TO ENHANCE BROAD SWATH OF PRECIP FROM NE/KS
INTO THE NWRN HALF OF IA. FORCING IS MAINLY KINEMATIC AND MID LEVEL
BASED DRIVEN BY DIVERGENCE AND DPVA...AND ALTHOUGH THERE IS LITTLE
TO NO THETA-E ADVECTION BELOW 3KM...THERE DOES APPEAR TO BE FAIRLY
HIGH BASED FRONTOGENETICAL FORCING AND RESPONSE. ENHANCED SW-NE
PRECIP BANDS LINE UP FAIRLY NICELY WITH RAP H7/H5 FN DIVERGENCE AND
LOWER STATIC STABILITY NOTED BY SLIGHTLY NEGATIVE EPV IN THE SAME
LAYER. HIGH RES MODEL PRECIP DEPICTIONS ARE IN QUITE GOOD AGREEMENT
BUT LOOK SLOW AT THE MOMENT SUGGESTING PRECIP WILL MAINLY BE IN THE
MORNING...AND CERTAINLY BE EXITING TO THE EAST 21Z-00Z.
TEMPS WILL BE PROBLEMATIC WITH EXTREMELY ANOMALOUS AIRMASS JUST
UPSTREAM. BOTH THE NAEFS CLIMATOLOGICAL AND GEFS M-CLIMATE
PERCENTILES ARE IN THEIR LOWEST AND HIGHEST RESPECTIVE 1 PERCENT FOR
TEMPS AND MSLP. THIS COLD AIRMASS COMBINED WITH PRECIP WILL RESULT
IN LITTLE TEMP REBOUND TODAY AND SOME NON-DIURNAL TRENDS WITH HIGHS
NO BETTER THAN THE LOWER 50S. ALTHOUGH NOT IN THE FORECAST...WOULD
NOT BE SURPRISED TO SEE A FEW SPOTS STRUGGLE TO REACH 50F. THESE
HIGHS WOULD AGAIN BREAK MIN MAX RECORDS WHICH RANGE FROM 53-56F AT
MASON CITY...WATERLOO...DES MOINES AND OTTUMWA.
.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 333 AM CDT FRI SEP 12 2014
LITTLE CHANGES TO THE GOING FORECAST AS MODELS REMAIN IN AGREEMENT
BOTH FROM RUN TO RUN AND AMONG EACH OTHER. LARGE AREA OF HIGH
PRESSURE TO BUILD INTO THE STATE TONIGHT WITH DRY CONDITIONS AND
CLEARING SKIES. VERY COLD AIR FOR THIS TIME OF YEAR TO REMAIN IN
PLACE ACROSS THE REGION...WITH H85 TEMPS AROUND 0C TONIGHT AND ONLY
WARMING TO AROUND +5C THROUGH THE WEEKEND. WITH THE COOL AIR AND
HIGH PRESSURE IN PLACE TONIGHT...CLEAR SKIES AND LIGHT WINDS
TEMPERATURES EXPECTED TO DROP OFF QUITE A BIT. HOWEVER THE TEMPS MAY
BE TEMPERED SOME BY THE LINGERING MOISTURE FROM ALL THE RAIN THE
PAST FEW DAYS AND ADDITIONAL RAIN TODAY...WHICH LEADS TO BEING
SOMEWHAT HESITANT ON POTENTIAL FOR FROST FORMATION AS WELL.
THEREFORE STUCK WITH LOWS IN THE MID TO UPPER 30S AND SOME PATCHY
FROST WORDING ACROSS THE WEST/NORTH WHERE COOLEST TEMPS EXPECTED.
HIGH PRESSURE TO DOMINATE OVER THE WEEKEND...WITH TEMPS GRADUALLY
WARMING A BIT. OTHERWISE NEXT CHANCE FOR PRECIPITATION AS ANOTHER
WEAK UPPER LEVEL WAVE AND ASSOCIATED COLD FRONT DROPS THROUGH THE
REGION. ANOTHER LARGE AREA OF HIGH PRESSURE TO THEN BUILD INTO THE
CENTRAL US FOR MUCH OF NEXT WEEK. THERMAL PROFILES WARM SOME WHICH
SHOULD ALLOW TEMPERATURES TO CREEP BACK INTO THE 70S BY WEDNESDAY
INTO THURSDAY. A LARGER UPPER LEVEL WAVE THEN LOOKS TO DIG INTO THE
CENTRAL US BY NEXT FRIDAY INTO THE WEEKEND WHICH SHOULD BRING
ADDITIONAL CHANCES FOR PRECIPITATION TO MUCH OF THE AREA. EVEN WITH
THE WARMING BY THE END OF THE FORECAST PERIOD...TEMPERATURES WILL
REMAIN WELL BELOW THE SEASONAL AVERAGES THROUGH MUCH OF NEXT WEEK.
&&
.AVIATION...12/12Z
ISSUED AT 651 AM CDT FRI SEP 12 2014
WIDESPREAD MVFR TO VFR CIGS WITH RAIN ARE IN PLACE FROM SW-NE IA
AT 12Z. THESE CONDITIONS WILL CONTINUE ADVANCING SOUTH AND EAST
THROUGH THE DAY GIVING WAY TO VFR CIGS AS THE PRECIP ENDS. LATER
THIS EVENING SKIES SHOULD CLEAR...LIKELY LEADING TO VFR
OVERNIGHT. WINDS WILL BECOME LIGHT...AND THERE IS SOME POTENTIAL
FOR RADIATION FOG TO RESTRICT VSBYS...BUT CONFIDENCE IS NOT THERE
FOR INCLUSION JUST YET.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...SMALL
LONG TERM...BEERENDS
AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1121 AM EDT FRI SEP 12 2014
LATEST UPDATE...
SHORT TERM/MARINE
.SYNOPSIS...
ISSUED AT 324 AM EDT FRI SEP 12 2014
COOL WEATHER WILL CONTINUE INTO THE WEEKEND. WEAK LOW PRESSURE
WILL BRING SOME SHOWERS LATE TODAY THROUGH TONIGHT. THE HIGH
PRESSURE BUILDS IN FOR SATURDAY AND SUNDAY. SOME FROST IS EXPECTED
NORTH OF GRAND RAPIDS SATURDAY NIGHT.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH SUNDAY EVENING)
ISSUED AT 1121 AM EDT FRI SEP 12 2014
LITTLE QUESTION THERE WILL BE RAIN ACROSS THE CWA TONIGHT THANKS A
CLOSING OFF UPPER LOW. THE BEST DYNAMICS ARE OVER CENTRAL AND
NORTHERN LOWER MICHIGAN... SO THAT IS WHERE IT BELIEVE THE HEAVIEST
RAIN WILL BE. NEARLY ALL OF OUR CWA WILL GET RAIN FROM THIS
SYSTEM. BASED ON THE LATEST HRRR AND LOOKING AT CONDENSATION
PRESSURE DEFICITS FROM THE NAM 12Z RUN... IT WOULD SEEM THE RAIN
MAY START AS EARLY AS 3-4 PM NEAR ROUTE 10 BUT NOT REACH I-96 TILL
NEAR US-131 BY 8-9 PM. I UPDATED THE GRIDS TO REFLECT THIS TIMING.
AS A SIDE NOTE SEEMS WE WILL GET A NORTH TO SOUTH MID LAKE
ENHANCED PRECIPITATION BAND BUT THAT SHOULD STAY OFF SHORE THROUGH
THE NIGHT DUE TO THE NORTH WINDS DURING THE EVENT TONIGHT. HOWEVER
THE BAND MAY TOUCH PARTS OF EXTREME WESTERN MASON COUNTY TOWARD
MORNING. IF IT DOES EXPECT A PERIOD OF HEAVIER RAIN SHOWERS.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 324 AM EDT FRI SEP 12 2014
THE FOCUS OF THE LONG TERM IS CENTERED ON THE MON/MON NIGHT TIME
FRAME WHEN OUR BEST CHC FOR PCPN WILL BE.
THE DRY WEATHER FOR THE LATTER HALF OF THE UPCOMING WEEKEND WILL
GRADUALLY COME TO AN END LATE SUN NIGHT AND MON ACROSS THE AREA. WE
WILL SEE A COLD FRONT DROP INTO THE AREA AT THAT TIME AS A LONG WAVE
TROUGH ACROSS CENTRAL AND EASTERN CANADA SLIPS SOUTH INTO THE AREA.
PCPN ALONG THE FRONT IS INITIALLY A BIT SPARSE...HOWEVER THIS LOOKS
TO CHANGE AS A STRONG SHORT WAVE ROUNDING THE BASE OF THE LONG WAVE
TROUGH WILL INTERACT WITH THE FRONT ON MON AND MON EVENING.
RAIN WILL COME TO AN END ACROSS THE ENTIRE AREA BY 12Z TUE AS THE
SHORT WAVE TROUGH AXIS MOVES EAST OF THE CWFA. DRY WEATHER IS THEN
LIKELY TO HOLD FOR THE REMAINDER OF THE WEEK. WE WILL SEE A COOL NW
FLOW HOLD IN ACROSS THE AREA FOR THE REMAINDER OF THE WEEK. THE GOOD
THING IS THAT WE WILL BE IMMEDIATELY DOWNSTREAM FROM THE LONG WAVE
UPPER RIDGE AXIS ACROSS THE ROCKIES. THE SUBSIDENCE DOWNSTREAM FROM
THE RIDGE WILL KEEP THE WEATHER QUIET AND COOL. THE RIDGE GETS
FLATTENED A BIT BY THE END OF THE PERIOD AS ENERGY DIVING SOUTH FROM
CANADA TRIES TO MOVE IN. THE UPPER JET WILL REMAIN NORTH OF THE AREA
AND WILL HOLD A COLD FRONT ACROSS LAKE SUPERIOR UP THERE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 732 AM EDT FRI SEP 12 2014
SOME IFR CEILINGS THIS MORNING AT AZO AND BTL BUT LOW STRATUS
SHOULD START TO LIFT TO MVFR THEN VFR BY THIS AFTERNOON. RAIN
SHOWERS WILL ARRIVE THIS EVENING WITH WIDESPREAD MVFR CONDITIONS
EXPECTED OVERNIGHT.
&&
.MARINE...
ISSUED AT 1121 AM EDT FRI SEP 12 2014
I ADDED WATER SPOUTS TO THE NEAR SHORE FORECAST FROM LATE
AFTERNOON INTO MID MORNING SATURDAY BASED ON THE CONVECTIVE DEPTH
BEING BETWEEN 10000 FT AND 15000 FT AT MID LAKE... USING LAKE
TEMP TO 850 TEMP DIFFERENCES BETWEEN 15C AND 18C. WINDS WILL NOT BE
STRONG ENOUGH FOR SCA. IN SUPPORT OF THAT...BEACH CAMS AT 11 AM SHOW
LITTLE IN THE WAY OF SIGNIFICANT WAVE ACTION. THE PORT SHELDON HAS
SHOWN 1 TO 1.3 FOOT WAVES OVER THE PAST SEVERAL HOURS.
&&
.HYDROLOGY...
ISSUED AT 324 AM EDT FRI SEP 12 2014
NO HYDRO ISSUES EXPECTED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS...OSTUNO
SHORT TERM...WDM
LONG TERM...NJJ
AVIATION...OSTUNO
HYDROLOGY...OSTUNO
MARINE...WDM
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1023 AM CDT FRI SEP 12 2014
.SYNOPSIS...
ISSUED AT 337 AM CDT FRI SEP 12 2014
STRONG HIGH HOLDS OVER THE SOUTHERN CONUS. MAINLY ZONAL FLOW FROM
THE MISSOURI VALLEY THROUGH THE EAST COAST. PROGRESSIVE TROUGH OVER
THE NORTHERN PLAINS AND WEAK RIDGING INTO THE PACIFIC NORTHWEST.
&&
.UPDATE...
ISSUED AT 1021 AM CDT FRI SEP 12 2014
MORNING TEMPS ON THE RISE SO ALLOWED FROST/FREEZE HEADLINE TO
EXPIRE ACROSS THE NORTHWEST. NO CHANGE TO THE FROST HEADLINE FOR
THE SOUTHEAST CWA TONIGHT. COLD AIR ALOFT SHOULD COMBINE WITH
WARMING TEMPS ACROSS N CENTRAL...AS SKIES ARE CLEARING THERE TO
PRODUCE STEEP AFTERNOON LAPSE RATES. CLOUDS SHOULD QUICKLY FORM
AND EVEN COULD SEEM SOME SPRINKLES OR LIGHT RAIN SHOWERS. NAM AND
THE HRRR SUPPORT THE LIGHT RAIN SHOWERS PRODUCING SOME POCKETS OF
QPF.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 337 AM CDT FRI SEP 12 2014
MODELS IN GOOD AGREEMENT AND WILL USE BLEND FOR THE FORECAST. MAIN
FORECAST CONCERN WILL BE ENDING OF PRECIPITATION AND PTYPE WITH
HIGHLIGHTS FOR FROST IN THE NORTHWEST THIS MORNING AND THEN FROST IN
THE FORECAST EARLY SATURDAY MORNING.
PRECIPITATION SOUTH OF A LINE FROM AINSWORTH TO OSHKOSH THIS MORNING.
MOST AREAS REPORTING RAIN THIS MORNING BUT SOME AREAS OF DRIZZLE AND
SIDNEY REPORTING SNOW WITH TEMPERATURES RIGHT AROUND FREEZING.
CEILINGS LIFTING TO THE NORTH AND SOME CLEARING OVER NORTHWEST SOUTH
DAKOTA. CLEARING LINE IS MOVING TO THE SOUTHEAST AROUND 20 KTS AND
SHOULD BE THROUGH KVTN MID MORNING. 1037MB SURFACE HIGH CENTERED
OVER KCDR THIS MORNING WITH 850MB TEMPERATURES AROUND -1C.
TEMPERATURES OVER NORTHWEST IN THE MID 30S WITH LIGHT NORTHERLY
WINDS WILL CONTINUE FREEZE WARNING FOR SHERIDAN COUNTY AND FROST
ADVISORY INTO THE WESTERN SANDHILLS. CLEARING SKIES THIS MORNING AND
PRECIPITATION ENDING AROUND NOON. MOST AREAS WILL SEE TEMPERATURES
IN THE 50S THIS AFTERNOON.
TONIGHT THE SURFACE HIGH WILL MOVE INTO SOUTH CENTRAL NEBRASKA WITH
SURFACE WINDS OVER WESTERN NEBRASKA FROM THE SOUTH UNDER CLEAR
SKIES. TEMPERATURES INTO THE 30S. HAVE ISSUED A FROST ADVISORY FROM
NORTH PLATTE TO BROKEN BOW FOR EARLY SATURDAY MORNING WITH PATCHY
FROST ALONG THE NORTH PLATTE RIVER VALLEY FROM NORTH PLATTE INTO THE
PANHANDLE. THE NORTHERN SANDHILLS LOOK TO STAY IN THE UPPER 30S FOR
LOWS AS 850MB TEMPERATURES WARM OVER NIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 337 AM CDT FRI SEP 12 2014
MODELS CONTINUE TO SHOW DECENT AGREEMENT FROM THE WEEKEND THROUGH
MUCH OF NEXT WEEK...LEADING TO FAIR TO GOOD CONFIDENCE IN THIS
FORECAST PACKAGE. THE UPPER LEVEL PATTERN WILL MODERATE OVER THE
NEXT FEW DAYS AND INTO THE FIRST PART OF NEXT WEEK...HOWEVER THE
LOCAL AREA WILL REMAIN UNDER THE INFLUENCE OF NORTHWEST FLOW UNTIL
LATER IN THE FORECAST PERIOD /WEDNESDAY AND THURSDAY/. AT THIS
TIME RIDGING LOOKS TO BUILD IN OVER THE PLAINS AS A LARGE-SCALE
TROUGH PUSHES ONTO THE WEST COAST.
BEGINNING ON SATURDAY...HIGH PRESSURE AT THE SURFACE WILL BE
LOCATED EAST OF THE AREA...WITH THE AXIS FROM CENTRAL KANSAS INTO
WISCONSIN. RETURN SOUTHERLY FLOW WILL BE IN PLACE THROUGH THE DAY
OVER MUCH OF THE AREA WHICH WILL ALLOW WARM AIR ADVECTION TO TAKE
PLACE AS 850MB TEMPERATURES RISE 10 TO 13 DEGREES IN THE 24 HOURS
ENDING AT 00Z SUNDAY. THAT BEING SAID...850MB TEMPERATURES WILL
ONLY RANGE FROM 8C TO 16C AT THAT TIME...LEAVING TEMPERATURES TO
REMAIN 10 TO 20 DEGREES BELOW NORMAL ON SATURDAY.
SATURDAY NIGHT AND SUNDAY WILL SEE ANOTHER INFLUX OF COLDER AIR
COMING IN FROM THE NORTH AS A COLD FRONT TIED TO AN UPPER LEVEL
SHORTWAVE TROUGH MOVING ACROSS THE DAKOTAS PUSHES ACROSS
NEBRASKA. THIS WILL LEAD TO CONTINUED BELOW NORMAL TEMPERATURES.
LIGHT WINDS SATURDAY NIGHT WILL ALLOW THE BOUNDARY LAYER TO
DECOUPLE AND WITH DRY AIR IN PLACE TO PROMOTE MOSTLY CLEAR
SKIES...EXPECTING DECENT RADIATIONAL COOLING...WITH LOWS FALLING
TO THE UPPER 30S TO MID 40S. ON SUNDAY 60S AND LOW 70S ARE LIKELY
FOR MUCH OF THE FORECAST AREA...WHILE AREAS ACROSS FAR SOUTHWEST
NEBRASKA COULD SEE MID TO UPPER 70S AS PLENTIFUL SUNSHINE IS
EXPECTED AND THE FRONT LAYS UP JUST NORTH OF THOSE AREAS TO KEEP THE
WARMER AIR IN PLACE. MUCH OF THE AREA WILL BE UNDER LARGE SCALE
SUBSIDENCE AS THE STATE SITS BETWEEN THE CONVERGENCE OF THE POLAR
AND TROPICAL JETS. THE POLAR JET MAY DIP SOUTH ENOUGH TO BRING
SOME ENHANCED LIFT TO NORTH CENTRAL NEBRASKA AS IT WOULD BE IN THE
RIGHT ENTRANCE REGION OF THE JET STREAK ON SUNDAY. HAVE INCLUDED A
LOW CHANCE FOR RAIN IN THESE AREAS FOR SUNDAY.
A SECOND SHORTWAVE TROUGH WILL BE RIGHT BEHIND THE SATURDAY SYSTEM
WHICH IS LOOKING TO BE STRONGER AND WILL DIG FROM THE DAKOTAS INTO
THE MID MISSISSIPPI RIVER VALLEY SUNDAY NIGHT AND MONDAY. THERE IS
SOME DIFFERENCES IN TIMING WITH THE PASSAGE OF THIS IMPULSE OF
ENERGY...HOWEVER AS IT MOVES THROUGH...WITH A COLD FRONT SITUATED
WEST TO EAST ACROSS KANSAS AND HIGH PRESSURE BUILDING SOUTHEAST
FROM THE NORTHERN HIGH PLAINS AN AREA OF CONVERGENCE WILL EXIST
ROUGHLY ALONG THE NEBRASKA/KANSAS BORDER. EASTERLY UPSLOPE FLOW IN
THE LOW LEVELS WILL BRING MORE MOIST AIR INTO THIS AREA AND CROSS
SECTIONS SHOW ENOUGH LIFT TO PRODUCE PRECIPITATION AS THE SYSTEM
MOVES THROUGH. THE NAM AND ECMWF ARE A BIT QUICKER THAN THE GFS
AND PRODUCE THE RAIN SUNDAY NIGHT...WHILE THE GFS WOULD INCLUDE
THE SHOWERS DURING THE DAY MONDAY. HEDGED TOWARDS THE FASTER
SOLUTIONS SO ADDED SHOWER AND ISOLATED THUNDER CHANCES FOR SUNDAY
NIGHT IN THE SOUTHERN COUNTIES. THIS RAIN WILL PUSH SOUTH THROUGH
THE DAY MONDAY AS THE SURFACE HIGH MOVES SOUTHEAST TO BRING MORE
DRY AIR INTO THE AREA...LEAVING A DRY FORECAST FOR MONDAY.
THE REMAINDER OF THE WEEK WILL SEE A FEW PERIODIC CHANCES FOR RAIN
AS SEVERAL WEAK SHORTWAVE TROUGHS MOVE THROUGH THE QUICK NORTHWEST
FLOW TO BRING FAVORABLE CONDITIONS FOR SOME RAIN OR THUNDERSTORMS
ACROSS PORTIONS OF THE AREA. CONFIDENCE ON TIMING OF THESE SYSTEMS
IS NOT HIGH...BUT DO BELIEVE THERE WILL BE SCATTERED SHOWERS AND
STORMS FROM TIME TO TIME THROUGH THE NEXT WEEK DESPITE WARMING
TEMPERATURES AS THE UPPER LEVEL RIDGE BUILDS INTO THE PLAINS.
SPEAKING OF TEMPERATURES...EXPECT A SLOW MODERATION OF
TEMPERATURES THROUGH THE FIRST HALF OF NEXT WEEK AS THE NORTHWEST
FLOW KEEPS COOLER AIR ACROSS THE AREA. BUT BY THURSDAY...850MB
TEMPERATURES RISE BACK INTO THE LOW 20S...SO LOOKING FOR A RETURN
TO NEAR TO ABOVE NORMAL TEMPERATURES WHICH ARE NEAR 80 DEGREES FOR
HIGHS AND 50 DEGREES FOR LOWS AT THIS TIME OF THE YEAR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 750 AM CDT FRI SEP 12 2014
PRECIPITATION WILL END OVER WESTERN NEBRASKA THIS MORNING.SOME
AREAS OF LIGHT RAIN AND DRIZZLE CONTINUE OVER SOUTHWEST NEBRASKA
SOUTH OF A LINE FROM BROKEN BOW TO IMPERIAL. LOW CLOUDS CEILINGS
IN IFR CATEGORIES WILL BEGIN TO LIFT EARLY THIS MORNING AS DRY AIR
MOVES EAST. VFR CONDITIONS EXPECTED AFTER 18Z OVER ALL OF WESTERN
AND NORTH CENTRAL NEBRASKA.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY FROM 4 AM TO 10 AM CDT SATURDAY FOR NEZ028-029-
038-059-071.
&&
$$
UPDATE...MASEK
SYNOPSIS...POWER
SHORT TERM...POWER
LONG TERM...BROOKS
AVIATION...POWER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1030 AM EDT FRI SEP 12 2014
.SYNOPSIS...
CLEARING SKIES...COOLER AND DRIER WEATHER IS EXPECTED TODAY WITH
HIGHS IN THE UPPER 50S TO MID 60S. TEMPERATURES WILL REMAIN EARLY
OCTOBER-LIKE THIS WEEKEND. SHOWERS WILL MOVE IN SATURDAY AFTERNOON
AND NIGHT AS AN AREA OF LOW PRESSURE MOVES ACROSS THE REGION. HIGH
PRESSURE WILL BRING A RETURN OF DRY WEATHER WITH SOME SUNSHINE ON
SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1025 AM EDT FRIDAY...WENT MORE PESSIMISTIC ON CLOUD COVER
AND THUS COOLER MAX TEMPS THIS AFTERNOON. VISIBLE SATELLITE
SHOWING SOLID CLOUD COVER AND MORE LOW LEVEL MOISTURE TO THE NORTH
STREAMING TO THE SOUTH. EXCEPTION IS IN SOUTHERN VERMONT AND
SOUTHERN ESSEX COUNTY NY WHERE DOWNSLOPE FLOW IS CREATING SOME
BREAKS IN THE CLOUD COVER. USED RUC13 925 MB RH FIELD TO POPULATE
SKY COVER THROUGH THE AFTERNOON AND THEN BLENDED INTO PREVIOUS
FORECAST TOWARD SUNSET. EVENTUALLY DRIER LAYER ABOVE THE CLOUDS
WILL MIX DOWNWARD, BUT WILL BE A STRUGGLE AS OVERCAST INHIBITS
SURFACE HEATING NEEDED TO OVERTURN THE BOUNDARY LAYER. UPDATED
TEMPS WITH LATEST LAV GUIDANCE WHICH DROPS MAX TEMPS A COUPLE
DEGREES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
AS OF 419 AM EDT FRIDAY...
IT WILL BE COOL ONCE AGAIN TONIGHT...STARTING OUT CLEAR BUT SOME
INCREASE IN CLOUDS OVERNIGHT WILL KEEP LOWS MOSTLY IN THE LOWER TO
MID 40S...EXCEPT FOR SOME 30S IN THE ADIRONDACKS AND NORTHEAST
VERMONT. MOST PLACES SHOULD ONCE AGAIN AVOID A FROST THOUGH HAVE
PUT A FEW GRIDS IN WITH PATCHY FROST AROUND SLK AND CANAAN.
ON SATURDAY...A WEAK (~1020 MB) LOW PRESSURE (1020 MB) DEVELOPS
OVER THE EASTERN GREAT LAKES AND MOVES UP THE ST. LAW VALLEY TO
NEAR CYUL BY 00Z SUNDAY IN RESPONSE TO A SHORT WAVE WITH 12 DM HGT
FALL NEAR CYUL AT 00Z SUN
SOME MODERATE QG FORCING WITH WARM ADVECTION AT 850-500 MB AND PV
ADVECTION ALOFT AND DIVERGENCE IN THE RIGHT ENTRANCE REGION OF 250
MB JET TO DRIVE VERTICAL MOTION. THIS COMBINED WITH SUFFICIENT
MOISTURE ADVECTION OF UP TO AN INCH OF PRECIPITABLE WATER WILL BE
ENOUGH TO PRODUCE SOME LIGHT RAIN/SHOWERS...WHICH WILL DEVELOP
FROM WEST TO EAST DURING THE AFTERNOON AND THEN TAPER OFF IN
SIMILAR FASHION SATURDAY NIGHT. PRECIPITATION AMOUNTS WILL BE
GENERALLY LIGHT...WITH 0.10-0.35 INCHES EXPECTED.
IT WILL CONTINUE COOL SAT BUT PERHAPS A FEW DEGREES COOLER THAN
TODAY WITH THICKENING CLOUD COVER AND DEPENDING ON WHEN THE RAIN
ARRIVES. 925 TEMP AGAIN AROUND +8C FOR HIGHS IN THE UPPER 50S TO
LOWER 60S.
COLD ADVECTION AND UPSLOPE FLOW BEHIND THE SYSTEM SATURDAY NIGHT
INTO EARLY SUNDAY WILL CONTINUE CLOUDS AND SOME CHANCE OF SHOWERS
MAINLY IN THE MOUNTAINS. LOW TEMPS IN THE 40S.
HIGH PRESSURE BUILDS IN SLOWLY FOR SUNDAY WITH RISING HEIGHTS AND
WEAK SHORTWAVE RIDGING BUT IT MAY UNTIL AFTERNOON SOMETIME TO
CLEAR OUT THE CLOUDS. 925 TEMPS A DEGREE COOLER SO HIGHS MID 50S
TO LOWER 60S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 435 AM EDT FRIDAY...ECMWF AND GFS MODELS IN GOOD AGREEMENT
IN SHOWING A RIDGE OF HIGH PRESSURE OVER THE REGION SUNDAY NIGHT
AND MONDAY WITH FAIR AND DRY WEATHER EXPECTED. LATE MONDAY NIGHT
INTO TUESDAY...MODELS SHOWING AN UPPER SHORTWAVE WILL DIG EAST-
SOUTHEAST FROM THE GREAT LAKES AND BRING A CHANCE OF RAIN SHOWERS
TO THE NORTH COUNTRY LATE MONDAY NIGHT INTO TUESDAY. GFS MODEL IS
FASTER THAN THE ECMWF MODEL IN BRINGING SHOWERS INTO THE REGION
LATE MONDAY NIGHT AND TUESDAY...AND ALSO WANTS TO END SHOWER
ACTIVITY EARLIER ON TUESDAY THAN THE ECMWF. ECMWF HAS MORE SHARPER
UPPER SHORTWAVE COMING FROM THE GREAT LAKES AND ALSO KEEPS IN
SHOWER ACTIVITY IN ACROSS THE REGION LONGER ON TUESDAY. HAVE GONE
WITH THE TIMING OF THE ECMWF FOR SHOWERS FOR LATE MONDAY NIGHT AND
TUESDAY. HIGH PRESSURE WILL THEN BUILD EAST FROM THE GREAT LAKES
AND OHIO VALLEY TUESDAY NIGHT AND WILL REMAIN OVER THE NORTH
COUNTRY THROUGH THURSDAY WITH FAIR AND DRY WEATHER EXPECTED. BELOW
NORMAL TEMPERATURES EXPECTED THROUGH THE PERIOD...WITH HIGHS
MAINLY IN THE 60S.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
THROUGH 06Z SATURDAY...SATELLITE LOOP AS OF 0600Z FRIDAY SHOWING
PLENTY OF LOW CLOUD COVER ACROSS THE REGION WITH MAINLY MVFR/VFR
CEILINGS. A RIDGE OF HIGH PRESSURE WILL BUILD INTO THE REGION TODAY.
EXPECTING CONDITIONS TO BECOME VFR THROUGHOUT BY 18Z FRIDAY. ALSO EXPECTING
LOW CLOUD COVER TO BECOME SCATTERED BY 18Z AS DRIER AIR WORKS INTO
THE REGION. EXPECTING SURFACE WINDS TO DIMINISH TO LESS THAN 10
KNOTS BY 14Z FRIDAY.
OUTLOOK 06Z SATURDAY THROUGH TUESDAY...
06Z-18Z SATURDAY...VFR EXCEPT FOR LOCAL IFR IN ANY PATCHY LATE
NIGHT FOG AT SLK AND MPV.
18Z SATURDAY - 12Z SUNDAY...MVFR POSSIBLE IN SHOWERS
12Z SUNDAY - 12Z TUESDAY...VFR EXCEPT POSSIBLE IFR IN LATE NIGHT
FOG AT SLK AND MPV.
12Z TUESDAY ONWARD...MVFR POSSIBLE IN SHOWERS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...SISSON
NEAR TERM...HANSON
SHORT TERM...SISSON
LONG TERM...WGH
AVIATION...WGH/NASH
AREA FORECAST DISCUSSION
NWS PUEBLO CO
303 PM MDT FRI SEP 12 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 242 PM MDT FRI SEP 12 2014
WIDESPREAD LOW CLOUDS CONTINUE TO COVER THE SERN CO PLAINS THIS
AFTERNOON...WITH TEMPS IN THE 40S. THE REST OF THE FORECAST AREA
HAS HAD MOSTLY SUNNY SKIES...WITH SOME CONVECTIVE CLOUDS DEVELOPING
OVER THE SRN MTNS AND SAN LUIS VALLEY. THERE CONTINUES TO BE SOME
SPOTTY LIGHT DRIZZLE IN LOCATIONS NR THE ERN MTNS. THE NAM HAS WAY
OVERDONE THE PCPN OVR THE SERN PLAINS FOR TODAY...WITH THE HRRR
BEING MORE REASONABLE. FOR THIS EVENING AND OVERNIGHT THE NAM
PRINTS OUT SOME ISOLD PCPN OVR THE SRN CO MTNS. THE HRRR IS DRY FOR
THIS EVENING. IT IS POSSIBLE THAT A FEW SHOWERS COULD DEVELOP FOR
THE EVENING HOURS...BUT FOR NOW WL LEAVE SILENT POPS IN THE
FORECAST. THE NAM AND HRRR ARE STILL SHOWING A DECREASE IN LOW LEVEL
CLOUD COVER LATER THIS AFTERNOON AND EARLY THIS EVENING...BUT NOT
SEEING ANY EVIDENCE OF THIS IN THE SATELLITE IMAGES YET. BOTH MODELS
THEN SHOW THE POTENTIAL FOR LOW CLOUD REFORMING OVR PORTIONS OF THE
PLAINS BY LATE EVENING. OVERNIGHT LOW TEMPS ARE EXPECTED TO BE IN
THE UPPER 30S TO LOWER 40S OVR THE SERN PLAINS...THE COLDEST AREAS
LOOK TO BE NORTHERN PORTIONS OF PUEBLO COUNTY...EL PASO AND CROWLEY
COUNTIES. LOWS IN THESE LOCATIONS LOOK LIKE THEY WL BE IN THE LOWER
30S. HAVE DECIDED TO ISSUE A FROST ADVISORY FOR THESE COUNTIES JUST
IN CASE THERE ARE POCKETS OF FROST.
MODELS ARE INDICATING THAT THE LOW CLOUDS SHOULD DISSIPATE BY LATE
MORNING ON SATURDAY WITH A GOOD WARM UP IN STORE. HIGHS ON SAT OVR
THE SERN PLAINS SHOULD BE IN THE 70S...WITH MID TO UPPER 70S IN THE
SAN LUIS VALLEY. GENERALLY DRY WESTERLY FLOW ALOFT IS EXPECTED OVR
THE FORECAST AREA. THE NAM AGAIN PRINTS OUT SOME LIGHT PCPN OVR THE
SRN CO MTNS AND SAN LUIS VALLEY SAT AFTERNOON...SO WL LEAVE SOME
ISOLD POPS IN THE FORECAST FOR THE SW MTNS AND THE SANGRES.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 242 PM MDT FRI SEP 12 2014
MODELS IN GOOD AGREEMENT THROUGH THE EXTENDED PERIOD WITH SMALL
ENSEMBLE SPREADS AND HIGHER FORECAST CONFIDENCE.
SATURDAY NIGHT THROUGH SUNDAY NIGHT...FLAT ZONAL WESTERLY FLOW
WILL PERSIST ACROSS COLORADO THROUGH THIS PERIOD AS AN UPPER RIDGE
BEGINS TO BUILD ALONG THE WEST COAST AND SHORTWAVE TROUGH DROPS
SOUTH OUT OF CANADA INTO THE NORTHERN PLAINS. EXPECT ISOLATED
SHOWERS AND THUNDERSTORMS OVER THE MOUNTAINS ON SATURDAY EVENING
TO DISSIPATE AROUND SUNDOWN WITH LOSS OF DAYTIME INSTABILITY.
OVERNIGHT LOWS WILL FALL INTO THE MID TO UPPER 40S FOR MUCH OF THE
REGION. A WEAK DISTURBANCE EMBEDDED IN THE WESTERLY FLOW ALOFT
WILL MOVE ACROSS THE STATE ON SUNDAY AFTERNOON. ANOTHER ROUND OF
ISOLATED TO SCATTERED MOUNTAIN SHOWERS AND THUNDERSTORMS ARE
EXPECTED...WHICH SHOULD DISSIPATE ON SUNDAY EVENING. HIGHS SUNDAY
WILL REACH INTO THE 80S FOR THE LOWER ELEVATIONS.
MONDAY AND MONDAY NIGHT...MODELS IN GOOD AGREEMENT WITH A STRONG
COLD FRONT DROPPING SOUTH ACROSS THE EASTERN PLAINS ON MONDAY
MORNING. THE NAM IS THE FASTEST SOLUTION...WITH IT CLEARING SOUTH
INTO NEW MEXICO BY 12Z...WHILE THE ECMWF AND GFS ARE ABOUT 6 HOURS
SLOWER. FEEL THAT A BIT FASTER SOLUTIONS WILL LIKELY PLAY OUT AND
FOLLOWED THE NAM FRONTAL PROGRESSION. EXPECT LOW LEVEL FLOW TO
TURN EASTERLY AND USHER IN MUCH COOLER AIR INTO THE PLAINS.
UPGLIDE AND MOISTURE BEHIND THE FRONT WILL LIKELY LEAD TO LIGHT
RAIN FOR THE PLAINS THROUGH MONDAY AFTERNOON. WARMER TEMPERATURES
AND GREATER INSTABILITY WILL EXIST OVER THE MOUNTAIN AREAS MONDAY
AFTERNOON AND SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED.
MODELS IN AGREEMENT WITH THE LIGHT RAIN COMING TO AN END FOR THE
PLAINS FROM NORTH TO SOUTH THROUGH THE AFTERNOON HOURS. EXPECT
THUNDERSTORMS OVER THE MOUNTAINS TO DISSIPATE AFTER SUNSET.
TEMPERATURES WILL BE MUCH COOLER BEHIND THE FRONT WITH THE PLAINS
LIKELY ONLY SEEING 60S FOR HIGHS.
TUESDAY THROUGH FRIDAY...THE UPPER PATTERN WILL BECOME AMPLIFIED
ACROSS THE CONUS WITH HIGH PRESSURE BUILDING OVER THE WEST AND A
TROUGH OVER THE EASTERN STATES. THIS WILL PUT SOUTHERN COLORADO
UNDER BROAD NORTHWEST FLOW. EXPECT GENERALLY DRY CONDITIONS ACROSS
THE REGION WITH DAILY AFTERNOON AND EVENING MOUNTAIN CONVECTION
POSSIBLE. TEMPERATURES WILL BE QUICK TO WARM UP WITH 80S FOR THE
LOWER ELEVATIONS THROUGH THE MIDDLE OF THE WEEK.
BY FRIDAY MODELS ARE BRINGING A PIECE OF ENERGY FROM TROPICAL
STORM ODILE WHICH IS FORECAST TO BE OFF THE NORTHERN BAJA COAST BY
FRIDAY. IF THIS DISTURBANCE AND MOISTURE DOES MATERIALIZE...THERE
WILL BE MUCH BETTER CHANCES FOR PRECIPITATION...ESPECIALLY ALONG
THE CONTINENTAL DIVIDE...BY FRIDAY. THIS WILL NEED TO BE
MONITORED. MOZLEY
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 242 PM MDT FRI SEP 12 2014
KPUB WL HAVE LOW VFR CIGS TONIGHT...POSSIBLY BEING MVFR AT TIMES.
CLOUD WILL DECREASE SAT MORNING WITH VFR CONDITIONS EXPECTED. KCOS
WL HAVE MVFR OR LOW VFR CONDITIONS TONIGHT. CLOUDS WILL DECREASE BY
LATE SAT MORNING. KALS IS EXPECTED TO HAVE VFR CONDITIONS TONIGHT
THROUGH SATURDAY.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY FROM 1 AM TO 8 AM MDT SATURDAY FOR COZ084>086-089.
&&
$$
SHORT TERM...28
LONG TERM...MOZLEY
AVIATION...28
AREA FORECAST DISCUSSION...CORRECTED
NWS MIAMI FL
147 PM EDT FRI SEP 12 2014
.AVIATION...
AREA OF LOW PRESSURE MOVING WEST SOUTHWEST ACROSS SOUTH CENTRAL
FLORIDA, IS RESPONSIBLE FOR INCREASING SHOWERS AND THUNDERSTORMS
NEAR KAPF AT THIS HOUR. SOME BRIEF IFR CONDS ARE POSSIBLE, BUT
TRAINING STORMS COULD CREATE MORE PERSISTENT IFR CONDS THERE IN
THE NEXT FEW HOURS. SHOWERS AND STORMS ACROSS THE ATLANTIC WATERS
ARE HAVING A DIFFICULT TIME CROSSING THE BEACHES, ESPECIALLY WITH
CLOUDS BREAKING. HOWEVER, INSOLATION THIS AFTERNOON MAY ALLOW
STORMS TO DEVELOP NEAR THE TAF SITES EVENTUALLY AS INSTABILITY
INCREASES. WITH EASTERLY FLOW CONTINUING TONIGHT, VCSH MAY BE
NEEDED FOR MUCH OF THE NIGHT WITH SHOWERS ARRIVING OVERNIGHT FROM
THE ATLANTIC WATERS.
&&
.PREV DISCUSSION... /ISSUED 833 AM EDT FRI SEP 12 2014/
AVIATION...
TROPICAL RAIN SHOWERS WITH EMBEDDED THUNDER ARE MOVING SSW THROUGH
SOUTH FLORIDA. THE HEAVIEST RAIN IS MOSTLY WEST OF THE TERMINALS
AT THIS HOUR, WITH LINES OF SHOWERS WITH SOME STORMS MOVING NORTH
ACROSS THE ATLANTIC WATERS DUE TO FLOW AROUND LOW PRESSURE. AS
THE AREA OF LOW PRESSURE MOVES SW, WHICH IS NOW JUST SW OF KPBI,
SHOWERS AND STORMS WILL LIKELY REDEVELOP ALONG THE COAST THIS
AFTERNOON ESPECIALLY WITH BREAKS IN THE CLOUDINESS ADDING TO THE
INSTABILITY. ALTHOUGH POPS ARE HIGH, PINPOINTING THUNDER IS MORE
TRICKY, SO MAY NEED TO WAIT A WHILE BEFORE INSERTING TEMPO GROUPS
FOR THIS AFTERNOON. DESPITE ABUNDANT MOISTURE, CONVERGENCE AND
NEARBY H5 DISTURBANCE, HRRR IS RATHER DRY THIS AFTERNOON, WHICH
REDUCES CONFIDENCE. 1K FT CIG THIS EARLY MORNING AT KPBI MAY
BRIEFLY FALL TO IFR, BEFORE IMPROVEMENT LATER THIS MORNING.
PREV DISCUSSION... /ISSUED 445 AM EDT FRI SEP 12 2014/
DISCUSSION...
VERY HEAVY RAIN IS FALLING ACROSS INLAND PALM BEACH COUNTY EARLY
THIS MORNING. THE AREA OF LOW PRESSURE MAY HAVE REDEVELOPED NEAR
THE COAST JUST OFF OF PALM BEACH COUNTY. AN MCV FEATURE DEVELOPED
OVER EASTERN PALM BEACH COUNTY VERY EARLY THIS MORNING TO THE
SOUTHWEST OF THE AREA OF LOW PRESSURE...WITH EXPANDING CLOUD TOPS
AS COLD AS -75C. THIS FEATURE HAS BEEN MOVING SLOWLY TOWARDS THE
WEST SOUTHWEST...WITH 2-3 INCH PER HOUR RAINFALL RATES. MORE
RECENTLY...THE HEAVIEST RAIN HAS BEEN WEAKENING IN INTENSITY AND
CLOUD TOPS HAVE BEGUN TO WARM. THE NORTH TO NORTHEASTERLY SHEAR
WILL PUSH THE HEAVIEST RAIN TO THE SOUTHWEST OF THE AREA OF LOW
PRESSURE...AND THE HEAVY RAIN MAY MOVES TOWARDS THE NAPLES REGION
LATER THIS MORNING IF IT HOLDS TOGETHER. LOCALLY HEAVY RAIN AND
FLOODING IS POSSIBLE...AND AN ISOLATED TORNADO CANNOT BE RULED
OUT.
FOR THE EAST COAST...POPS MAY BE A LITTLE TOO HIGH DUE TO THE
CLOUD COVER AND STORMS BEING PUSHED TO THE SOUTHWEST OF THE AREA
OF LOW PRESSURE. HOWEVER...STORMS COULD REDEVELOP AND FOCUS OVER
THE EAST COAST THIS AFTERNOON...AND MOST AREAS WILL SEE AT LEAST
LIGHT RAIN THIS MORNING. SO KEPT LIKELY POPS ACROSS THE
BOARD...BUT AMOUNTS ARE UNCERTAIN AT THIS TIME. FOR
TEMPERATURES...MOST LOCATIONS WILL REACH THE LOW/MID 80S...WITH
RAIN COOLED LOCATIONS REMAINING IN THE 70S.
THE AREA OF LOW PRESSURE/MCV WILL MOVE WEST SOUTHWEST ACROSS THE
REGION THROUGH THE DAY...AND EXIT INTO THE GULF OF MEXICO TONIGHT.
THE MODELS STILL DIFFER ON THE LOCATION OF THE LOW AND RAINFALL
CHANCES ACROSS THE REGION OVERNIGHT. THE ECMWF IS MUCH WETTER THAN
THE GFS...KEEPING DEEPER MOISTURE AND MORE SOUTHERLY FLOW ACROSS
SOUTH FLORIDA. KEPT WITH THE WETTER SOLUTION FOR THE SOUTHERN
PORTIONS OF THE REGION AND THE COASTAL AREAS OVERNIGHT.
SATURDAY...RIDGE OF HIGH PRESSURE WILL BUILD OVER THE WESTERN
ATLANTIC TO THE NORTHEAST OF THE REGION ON SATURDAY. THE AREA OF
LOW PRESSURE WILL CONTINUE WESTWARD INTO THE SOUTH CENTRAL GULF.
SOUTHEAST FLOW AND DEEP MOISTURE IS FORECAST TO CONTINUE...AND
RAIN CHANCES WILL CONTINUE IN THE 50-70 PERCENT RANGE...HIGHEST
ACROSS THE GULF COAST.
SUNDAY...DIFFERENCES STILL REMAIN IN THE MODELS ON SUNDAY. THE GFS
IS MUCH FASTER WITH THE AREA OF LOW PRESSURE OVER THE GULF.
THUS...THE REGION WOULD RETURN TO A MORE TYPICAL EASTERLY FLOW
REGIME...WITH SCATTERED STORMS DEVELOPING INLAND OF THE EAST COAST
AND THEN PUSHING TOWARDS THE GULF COAST IN THE AFTERNOON. THE
ECMWF IS MORE THAN 2 DEGREES TO THE EAST. THE ECMWF KEEPS THE
MOISTURE AXIS ACROSS SOUTH FLORIDA FROM THE AREA OF LOW PRESSURE
OVER THE GULF...WITH A LIGHT SOUTHERLY FLOW ACROSS THE REGION.
RAIN CHANCES WOULD THEN REMAIN VERY HIGH ACROSS MOST OF THE
REGION. FOR NOW KEPT SCATTERED POPS ALONG THE EAST COAST AND
LIKELY ACROSS THE INTERIOR AND GULF.
EARLY TO MIDDLE OF NEXT WEEK...AN UPPER TROUGH IS FORECAST TO DIG
ACROSS THE EASTERN CONUS AND INTO THE SOUTHEAST THE EARLY TO MIDDLE
PART OF THE WEEK. THE ECMWF IS DEEPER WITH THE TROUGH AND PUSHES A
COLD FRONT INTO SOUTHERN GEORGIA BY THE MIDDLE OF THE WEEK. THE
ECMWF PUSHES THE RIDGE AXIS OVER THE REGION ON MONDAY AND THEN
SOUTH OF THE REGION BY THE MIDDLE OF THE WEEK...WITH WEST TO
SOUTHWESTERLY FLOW. THIS WOULD FAVOR HIGHER RAIN CHANCES FOR THE
EAST AND NORTHEAST METRO AREAS.
AVIATION...
A WEAK AREA OF LOW PRESSURE CENTERED AROUND THE PALM BEACH COAST
WILL CONTINUE WESTWARD TOWARD THE GULF COAST THROUGH THE PERIOD.
PERIODS OF HEAVY RAINFALL WILL REMAIN IN THE FORECAST ACROSS THE
SOUTH FLORIDA REGION THROUGH THIS TIME. WINDS OVER THE EAST COAST
TAF SITES WILL SHIFT TO THE SOUTHEAST SOMETIME THROUGH THE
AFTERNOON HOURS TODAY AS THE LOW CONTINUES WESTWARD. WINDS AT
NAPLES WILL REMAIN LIGHT AND VARIABLE THROUGH THE PERIOD AS
UNCERTAINTY REGARDING THE EXACT TRACK OF THE LOW RELATIVE TO THE
APF TERMINAL REMAINS HIGH AT THIS TIME. AS THE LOW SHIFTS WESTWARD
OFF OF THE NAPLES COAST...LIGHT TO MODERATE SE WINDS WILL RETURN
ACROSS THE AREA. /85
MARINE...
A WEAK AREA OF LOW PRESSURE NEAR THE PALM BEACH COAST EARLY THIS
MORNING WILL MOVE ACROSS SOUTH FLORIDA TODAY...AND THEN INTO THE
REGIONAL GULF WATERS TONIGHT. THERE COULD BE SOME WATERSPOUTS
TODAY, ESPECIALLY ACROSS THE ATLANTIC WATERS, WITH CIRCULATION
AROUND THE AREA OF LOW PRESSURE, WHICH WILL BE MOVING SW THROUGH
SOUTH FLORIDA TODAY. RAIN CHANCES WILL REMAIN HIGH OVER THE
ATLANTIC AND GULF WATERS TODAY INTO THE WEEKEND. THE NHC IS
MONITORING THIS AREA OF LOW PRESSURE...AND THERE IS A MEDIUM
CHANCE OF DEVELOPMENT ONCE IT MOVES INTO THE GULF OF MEXICO. THIS
COULD IMPACT THE GULF FORECAST OVER THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 76 88 76 89 / 40 50 40 50
FORT LAUDERDALE 77 89 77 90 / 40 60 40 50
MIAMI 77 89 77 90 / 40 60 40 50
NAPLES 73 89 74 91 / 50 70 30 60
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...60/BD
LONG TERM....60/BD
AVIATION...21/KM
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1240 PM CDT FRI SEP 12 2014
.SHORT TERM /TODAY/...
ISSUED AT 333 AM CDT FRI SEP 12 2014
PRECIP AND TEMP TRENDS WILL BE THE PRIMARY CONCERNS TODAY. RIGHT
ENTRANCE REGION DIVERGENCE OF STRONG 120KT JET FROM MO VALLEY INTO
SERN CANADA CONTINUES TO ENHANCE BROAD SWATH OF PRECIP FROM NE/KS
INTO THE NWRN HALF OF IA. FORCING IS MAINLY KINEMATIC AND MID LEVEL
BASED DRIVEN BY DIVERGENCE AND DPVA...AND ALTHOUGH THERE IS LITTLE
TO NO THETA-E ADVECTION BELOW 3KM...THERE DOES APPEAR TO BE FAIRLY
HIGH BASED FRONTOGENETICAL FORCING AND RESPONSE. ENHANCED SW-NE
PRECIP BANDS LINE UP FAIRLY NICELY WITH RAP H7/H5 FN DIVERGENCE AND
LOWER STATIC STABILITY NOTED BY SLIGHTLY NEGATIVE EPV IN THE SAME
LAYER. HIGH RES MODEL PRECIP DEPICTIONS ARE IN QUITE GOOD AGREEMENT
BUT LOOK SLOW AT THE MOMENT SUGGESTING PRECIP WILL MAINLY BE IN THE
MORNING...AND CERTAINLY BE EXITING TO THE EAST 21Z-00Z.
TEMPS WILL BE PROBLEMATIC WITH EXTREMELY ANOMALOUS AIRMASS JUST
UPSTREAM. BOTH THE NAEFS CLIMATOLOGICAL AND GEFS M-CLIMATE
PERCENTILES ARE IN THEIR LOWEST AND HIGHEST RESPECTIVE 1 PERCENT FOR
TEMPS AND MSLP. THIS COLD AIRMASS COMBINED WITH PRECIP WILL RESULT
IN LITTLE TEMP REBOUND TODAY AND SOME NON-DIURNAL TRENDS WITH HIGHS
NO BETTER THAN THE LOWER 50S. ALTHOUGH NOT IN THE FORECAST...WOULD
NOT BE SURPRISED TO SEE A FEW SPOTS STRUGGLE TO REACH 50F. THESE
HIGHS WOULD AGAIN BREAK MIN MAX RECORDS WHICH RANGE FROM 53-56F AT
MASON CITY...WATERLOO...DES MOINES AND OTTUMWA.
.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 333 AM CDT FRI SEP 12 2014
LITTLE CHANGES TO THE GOING FORECAST AS MODELS REMAIN IN AGREEMENT
BOTH FROM RUN TO RUN AND AMONG EACH OTHER. LARGE AREA OF HIGH
PRESSURE TO BUILD INTO THE STATE TONIGHT WITH DRY CONDITIONS AND
CLEARING SKIES. VERY COLD AIR FOR THIS TIME OF YEAR TO REMAIN IN
PLACE ACROSS THE REGION...WITH H85 TEMPS AROUND 0C TONIGHT AND ONLY
WARMING TO AROUND +5C THROUGH THE WEEKEND. WITH THE COOL AIR AND
HIGH PRESSURE IN PLACE TONIGHT...CLEAR SKIES AND LIGHT WINDS
TEMPERATURES EXPECTED TO DROP OFF QUITE A BIT. HOWEVER THE TEMPS MAY
BE TEMPERED SOME BY THE LINGERING MOISTURE FROM ALL THE RAIN THE
PAST FEW DAYS AND ADDITIONAL RAIN TODAY...WHICH LEADS TO BEING
SOMEWHAT HESITANT ON POTENTIAL FOR FROST FORMATION AS WELL.
THEREFORE STUCK WITH LOWS IN THE MID TO UPPER 30S AND SOME PATCHY
FROST WORDING ACROSS THE WEST/NORTH WHERE COOLEST TEMPS EXPECTED.
HIGH PRESSURE TO DOMINATE OVER THE WEEKEND...WITH TEMPS GRADUALLY
WARMING A BIT. OTHERWISE NEXT CHANCE FOR PRECIPITATION AS ANOTHER
WEAK UPPER LEVEL WAVE AND ASSOCIATED COLD FRONT DROPS THROUGH THE
REGION. ANOTHER LARGE AREA OF HIGH PRESSURE TO THEN BUILD INTO THE
CENTRAL US FOR MUCH OF NEXT WEEK. THERMAL PROFILES WARM SOME WHICH
SHOULD ALLOW TEMPERATURES TO CREEP BACK INTO THE 70S BY WEDNESDAY
INTO THURSDAY. A LARGER UPPER LEVEL WAVE THEN LOOKS TO DIG INTO THE
CENTRAL US BY NEXT FRIDAY INTO THE WEEKEND WHICH SHOULD BRING
ADDITIONAL CHANCES FOR PRECIPITATION TO MUCH OF THE AREA. EVEN WITH
THE WARMING BY THE END OF THE FORECAST PERIOD...TEMPERATURES WILL
REMAIN WELL BELOW THE SEASONAL AVERAGES THROUGH MUCH OF NEXT WEEK.
&&
.AVIATION...12/18Z
ISSUED AT 1232 PM CDT FRI SEP 12 2014
NEXT 6 OR SO HOURS IS WINDOW OF MAIN WEATHER AS TAF SITES HOVER IN
MVFR CEILINGS. AFTER 02Z...ALL SITES BECOMING SKC...WITH CALM WINDS
THROUGH SUNRISE SATURDAY MORNING AS HIGH PRESSURE TO BLAST AWAY
CLOUDS AND PUT ALL TAF SITES INTO VFR. FOR THE REST OF
TODAY...BAND OF SHOWERS TO CONTINUE MOVING EASTWARD. NO REASON FOR
PRECIP TO INTENSIFY AND/OR PRODUCE TS...SO HAVE LEFT THUNDER OUT
OF TAFS AND HAVE NOT REDUCED VSBYS BELOW 6SM.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SMALL
LONG TERM...BEERENDS
AVIATION...KOTENBERG
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
208 PM CDT FRI SEP 12 2014
...UPDATED LONG TERM SECTION...
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 144 PM CDT FRI SEP 12 2014
SKIES WILL CLEAR FROM NORTH TO SOUTH EARLY TONIGHT ACROSS WESTERN
KANSAS AS SUBSIDENCE DEVELOPS BEHIND AN UPPER LEVEL TROUGH AS IT
MOVES INTO THE MISSISSIPPI VALLEY. AS SKIES CLEAR THE SURFACE
WINDS WILL BECOME LIGHT AS A SURFACE HIGH BUILDS ACROSS NORTHERN
AND CENTRAL KANSAS. MODELS TODAY ARE IN GOOD AGREEMENT WITH THE
LIGHTER WINDS NEAR THE CENTER OF THE SURFACE HIGH TO BE LOCATED
EAST OF HIGHWAY 283 BETWEEN MIDNIGHT AND 7 AM SATURDAY. BASED ON
THESE LIGHT WINDS, CLEARING SKIES, AND EXPECTED SURFACE DEW
POINTS EARLY SATURDAY MORNING WILL UNDERCUT THE COOLER MET
GUIDANCE BY A FEW DEGREES ACROSS NORTH CENTRAL AND SOUTH CENTRAL
KANSAS FOR OVERNIGHT LOWS. WILL STAY NEAR THE LATEST MET/MAV
FURTHER WEST GIVEN THE SLIGHT INCREASE IN WINDS AFTER MIDNIGHT.
THIS SOLUTION CONTINUES TO SUPPORT THE PREVIOUS FORECAST WITH LOWS
BOTTOMING OUT IN THE MID 30S TO NEAR 40 WITH THE THE COOLER
TEMPERATURES OCCURRING ACROSS NORTH CENTRAL AND PORTIONS OF WEST
CENTRAL KANSAS. SOME PATCHY FROST WILL ALSO BE POSSIBLE NORTH OF A
PRATT TO SYRACUSE LINE.
ON SATURDAY A TROUGH OF LOW PRESSURE AT THE SURFACE WILL DEVELOP
ALONG THE LEE OF THE ROCKIES AS A WESTERLY DOWN SLOPE FLOW
IMPROVES ACROSS THE CENTRAL HIGH PLAINS. SOUTHERLY WINDS WILL
INCREASE DURING THE DAY ACROSS ALL OF WESTERN KANSAS AS THE
SURFACE PRESSURES FALL ALONG THE LEE OF THE ROCKIES. IN ADDITION
TO THE INCREASING WINDS ON SATURDAY THE 850MB TEMPERATURES AT 00Z
SUNDAY WILL RANGE FROM NEAR 8C IN NORTH CENTRAL KANSAS TO 17C
ALONG THE COLORADO BORDER. THIS IS A 5C TO 10C WARM UP BETWEEN 00Z
SATURDAY TO 00Z SUNDAY. USING THIS AS A GUIDE FOR HIGHS SATURDAY
AFTERNOON THE PREVIOUS SHIFT STILL LOOKS ON TRACK WITH
TEMPERATURES CLIMBING INTO THE MID 60S TO LOWER 70S. THE WARMER
TEMPERATURES WILL BE LOCATED NEAR THE COLORADO BORDER.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 203 PM CDT FRI SEP 12 2014
THE REMNANTS OF TROPICAL STORM FENGSHEN THAT INTENSIFIED BRIEFLY
EAST OF JAPAN ON 7 SEPTEMBER RIPPLED THROUGH THE WESTERLIES AND WAS
MOVING OVER WESTERN ALASKA ON THE EAST SIDE OF AN INTENSE UPPER
LEVEL CYCLONE CENTERED NEAR 170W THIS MORNING. STRONG RIDGING WAS IN
PROGRESS FROM THE WEST COAST OF CANADA ACROSS THE NORTHWEST
TERRITORIES INTO NORTHERN ALASKA. DOWNSTREAM AMPLIFICATION OF A MEAN
LONG WAVE TROUGH IN EASTERN CANADA WAS IN PROGRESS AND LIKELY WILL
CONTINUE THROUGH MID WEEK. SEVERAL SHORT WAVE TROUGHS EMBEDDED IN
THE POLAR JET WILL MOVE OVER THE PROGRESSIVE LONG WAVE RIDGE AND DIG
INTO THE MEAN TROUGH POSITION IN THE EXTENDED PERIOD. THE LONG WAVE
RIDGE WILL WEAKEN AS THE UPPER LEVEL LOW WEST OF ALASKA OCCLUDES AND
WEAKENS AND WILL PROGRESS INTO THE WESTERN UNITED STATES EARLY NEXT
WEEK. BROAD RIDGING WILL BUILD INTO THE CENTRAL PLAINS NEXT THURSDAY
AND FRIDAY, AND ANOTHER STRONG PROGRESSIVE TROUGH WILL MOVE INTO THE
NORTHERN PLAINS LATE NEXT WEEK.
A KELVIN WAVE WAS MOVING RAPIDLY EAST THROUGH THE WESTERN HEMISPHERE
AND WAS CENTERED NEAR 120W THIS MORNING. THE NUMERICAL MODELS
SUGGEST THAT THE KELVIN WAVE WILL CONTINUE ITS EASTWARD PROGRESSION
AND ENHANCE THUNDERSTORM COVERAGE IN AFRICA BY AROUND 20 SEPTEMBER.
TROPICAL CYCLONE DEVELOPMENT WILL CONTINUE TO BE FAVORED IN THE
EASTERN PACIFIC AS THE KELVIN WAVE PASSES, AND ENHANCED HIGH LEVEL
TROPICAL MOISTURE ASSOCIATED WITH ODILE MAY MOVE INTO THE CENTRAL
PLAINS NEXT WEEKEND.
AN UPPER LEVEL TROUGH IN THE NORTHWEST TERRITORIES WILL DIG INTO THE
DAKOTAS SUNDAY, AND AN AREA OF LOW PRESSURE WILL DEEPEN IN EASTERN
COLORADO. A PLUME OF WARM AIR WILL SPREAD ACROSS WESTERN KANSAS
SUNDAY, AND TEMPERATURES WILL RISE BACK TO NEAR SEASONAL AVERAGES
SUNDAY AFTERNOON. AN ELEVATED MIXED LAYER WILL SPREAD ACROSS KANSAS
SUNDAY, AND H7 TEMPERATURES WILL BE AT LEAST 10C IN WESTERN KANSAS
SUNDAY AFTERNOON. THERE WILL BE SOME WEAK SURFACE CONVERGENCE ALONG
A WARM FRONT AS IT LIFTS NORTH ACROSS WESTERN KANSAS SUNDAY, BUT
VERY WARM TEMPERATURES ALOFT LIKELY WILL PRECLUDE DEVELOPMENT OF
THUNDERSTORMS ALONG THE BOUNDARY. THUNDERSTORMS OVER THE HIGHER
TERRAIN IN COLORADO MAY APPROACH THE KANSAS BORDER SUNDAY EVENING
BUT PROBABLY WILL BE NORTH OF HAMILTON COUNTY.
A COLD FRONT WILL MOVE INTO NORTHERN KANSAS SUNDAY NIGHT AND SHOULD
REACH MEDICINE LODGE BY LATE MORNING MONDAY. THE GFS AND GEM ARE
SLIGHTLY MORE AMPLIFIED WITH THE UPPER LEVEL TROUGH THAT DIGS
THROUGH THE NORTHERN PLAINS SUNDAY NIGHT THAN THE GFS AND ARE A
LITTLE FASTER WITH THE COLD FRONTAL PASSAGE. A NUMBER OF THE GFS
ENSEMBLE MEMBERS ARE FASTER WITH THE FRONT THAN THE OPERATIONAL RUN
AND ARE MORE IN AGREEMENT WITH THE ECMWF AND GEM. THE PREPONDERANCE
OF EVIDENCE SUPPORTS THE FASTER MOVEMENT OF THE FRONT, AND THE ECMWF
LARGELY WAS USED FOR MINOR GRID ADJUSTMENTS. THE FRONT WILL PASS
DURING THE NIGHTTIME HOURS UNDER A PLUME OF WARM TEMPERATURES ALOFT,
AND THUNDERSTORM DEVELOPMENT ALONG THE BOUNDARY LIKELY WILL BE
CONFINED TO NORTH CENTRAL AND EASTERN KANSAS WHERE MID LEVEL
TEMPERATURES ARE SLIGHTLY COOLER AND ISENTROPIC LIFTING WILL ENHANCE
UPWARD VERTICAL MOTION IN THE WARM SECTOR. WIDESPREAD STRATUS WILL
MOVE INTO WESTERN KANSAS BEHIND THE COLD FRONT AND WILL KEEP
TEMPERATURES COOL DURING THE DAY MONDAY. THERE MAY BE SOME LIGHT
SHOWERS IN THE ELEVATED FRONTOGENETIC REGION BEHIND THE SURFACE
BOUNDARY, BUT SIGNIFICANT RAINFALL IS UNLIKELY.
UPPER LEVEL RIDGING WILL BUILD TOWARD THE CENTRAL PART OF THE
COUNTRY TUESDAY THROUGH FRIDAY, AND TEMPERATURES WILL WARM INTO THE
UPPER 70S AND LOWER 80S TUESDAY. HIGHS WEDNESDAY THROUGH FRIDAY
LIKELY WILL BE IN THE UPPER 80S AND LOWER 90S. A MINOR UPPER LEVEL
TROUGH IN THE NORTHWEST FLOW ALOFT WILL MOVE FROM SOUTH DAKOTA INTO
THE MISSISSIPPI VALLEY WEDNESDAY, AND A WEAK FRONT WILL MOVE INTO
WESTERN KANSAS DURING THE DAY AND BECOME STATIONARY NEAR THE
OKLAHOMA BORDER WEDNESDAY AFTERNOON. THIS MAY PROVIDE A FOCUS FOR
DEVELOPMENT OF A FEW AFTERNOON THUNDERSTORMS AND ADDITIONAL
NOCTURNAL THUNDERSTORMS AS A MODEST LOW LEVEL JET DEVELOPS AND
ENHANCES ISENTROPIC LIFTING IN SOUTH CENTRAL KANSAS. THE BOUNDARY
MAY STILL BE WALLOWING IN KANSAS THURSDAY, AND ANOTHER ROUND OF
NOCTURNAL THUNDERSTORMS MAY OCCUR IN CENTRAL KANSAS THURSDAY NIGHT.
BY SATURDAY A COLD FRONT WILL ENTER WESTERN KANSAS AND PROVIDE
ANOTHER OPPORTUNITY FOR THUNDERSTORM DEVELOPMENT. TROPICAL HIGH
LEVEL MOISTURE FROM ODILE MAY ENHANCE RAINFALL POTENTIAL WITH THE
FRONT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1203 PM CDT FRI SEP 12 2014
AN AREA OF HIGH PRESSURE AT THE SURFACE WILL BUILD ACROSS NORTHERN
AND CENTRAL KANSAS OVERNIGHT. THIS WILL RESULT IN DECREASING
NORTHERLY WINDS THIS AFTERNOON AND LIGHT WINDS OVERNIGHT GRADUALLY
VEERING TO THE EAST/SOUTHEAST TOWARDS BY DAYBREAK ON SATURDAY.
CLEARING CONDITIONS WILL DEVELOP FROM NORTH OF SOUTH LATE TODAY
BEHIND AN UPPER LEVEL TROUGH WHICH WILL MOVE OUT OF THE NORTHERN
PLAINS LATE THIS AFTERNOON INTO THE MID/UPPER MISSISSIPPI VALLEY.
BASED ON BUFR SOUNDINGS AND HRRR MVFR CONDITIONS ARE EXPECTED TO
IMPROVE INTO THE VFR CATEGORY BETWEEN 21Z FRIDAY AND 00Z SATURDAY.
SOME PATCHY FOG WILL BE POSSIBLE AROUND DAYBREAK GIVEN CLEAR SKIES
AND LIGHT EAST/SOUTHEAST WINDS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 37 67 49 79 / 0 0 10 0
GCK 36 68 49 79 / 0 0 0 0
EHA 41 72 52 80 / 0 0 10 0
LBL 39 71 53 81 / 0 0 10 0
HYS 35 64 47 77 / 0 0 10 0
P28 39 68 52 79 / 0 0 10 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURGERT
LONG TERM...RUTHI
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
147 PM CDT FRI SEP 12 2014
...UPDATED SHORT TERM DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 144 PM CDT FRI SEP 12 2014
SKIES WILL CLEAR FROM NORTH TO SOUTH EARLY TONIGHT ACROSS WESTERN
KANSAS AS SUBSIDENCE DEVELOPS BEHIND AN UPPER LEVEL TROUGH AS IT
MOVES INTO THE MISSISSIPPI VALLEY. AS SKIES CLEAR THE SURFACE
WINDS WILL BECOME LIGHT AS A SURFACE HIGH BUILDS ACROSS NORTHERN
AND CENTRAL KANSAS. MODELS TODAY ARE IN GOOD AGREEMENT WITH THE
LIGHTER WINDS NEAR THE CENTER OF THE SURFACE HIGH TO BE LOCATED
EAST OF HIGHWAY 283 BETWEEN MIDNIGHT AND 7 AM SATURDAY. BASED ON
THESE LIGHT WINDS, CLEARING SKIES, AND EXPECTED SURFACE DEW
POINTS EARLY SATURDAY MORNING WILL UNDERCUT THE COOLER MET
GUIDANCE BY A FEW DEGREES ACROSS NORTH CENTRAL AND SOUTH CENTRAL
KANSAS FOR OVERNIGHT LOWS. WILL STAY NEAR THE LATEST MET/MAV
FURTHER WEST GIVEN THE SLIGHT INCREASE IN WINDS AFTER MIDNIGHT.
THIS SOLUTION CONTINUES TO SUPPORT THE PREVIOUS FORECAST WITH LOWS
BOTTOMING OUT IN THE MID 30S TO NEAR 40 WITH THE THE COOLER
TEMPERATURES OCCURRING ACROSS NORTH CENTRAL AND PORTIONS OF WEST
CENTRAL KANSAS. SOME PATCHY FROST WILL ALSO BE POSSIBLE NORTH OF A
PRATT TO SYRACUSE LINE.
ON SATURDAY A TROUGH OF LOW PRESSURE AT THE SURFACE WILL DEVELOP
ALONG THE LEE OF THE ROCKIES AS A WESTERLY DOWN SLOPE FLOW
IMPROVES ACROSS THE CENTRAL HIGH PLAINS. SOUTHERLY WINDS WILL
INCREASE DURING THE DAY ACROSS ALL OF WESTERN KANSAS AS THE
SURFACE PRESSURES FALL ALONG THE LEE OF THE ROCKIES. IN ADDITION
TO THE INCREASING WINDS ON SATURDAY THE 850MB TEMPERATURES AT 00Z
SUNDAY WILL RANGE FROM NEAR 8C IN NORTH CENTRAL KANSAS TO 17C
ALONG THE COLORADO BORDER. THIS IS A 5C TO 10C WARM UP BETWEEN 00Z
SATURDAY TO 00Z SUNDAY. USING THIS AS A GUIDE FOR HIGHS SATURDAY
AFTERNOON THE PREVIOUS SHIFT STILL LOOKS ON TRACK WITH
TEMPERATURES CLIMBING INTO THE MID 60S TO LOWER 70S. THE WARMER
TEMPERATURES WILL BE LOCATED NEAR THE COLORADO BORDER.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 302 AM CDT FRI SEP 12 2014
THIS EXTENDED PERIOD WILL BE DOMINATED BY A SERIES OF UPPER LEVEL
TROUGHS AND WAVES. THE FIRST WILL COME ALONG ABOUT LATE SUNDAY
NIGHT, DRAGGING A COLD FRONT DOWN THROUGH THE CENTRAL PLAINS WITH
IT. SATURDAY AND SUNDAY WILL GO THROUGH A SLOW WARMING TREND, WITH
MID 60S TO LOWER 70S FOR HIGHS ON SATURDAY, FOLLOWED BY HIGHS ON
SUNDAY IN THE UPPER 70S TO NEAR 80F DEGREE RANGE. THE FLOW ALOFT
DURING THE WEEKEND WILL BE ZONAL, WITH A BROAD HIGH PRESSURE RIDGE
TO OUR SOUTH AND AN UPPER TROUGH TO OUR NORTHEAST. THE IS A TROUGH
AND ASSOCIATED COLD FRONT SWEEPING DOWN FROM THE NORTH SUNDAY
NIGHT INTO MONDAY, WHICH WILL BRING A CHANCE FOR THUNDERSTORMS TO
SOUTHWESTERN KANSAS. I DID NOT GO VERY HIGH WITH POPS MONDAY,
EXCEPT FOR 30 TO 40 PERCENT IN OUR SOUTHEAST ZONES NEAR BARBER
AND PRATT COUNTIES, WHERE MOISTURE WILL BE THE GREATEST. IT WILL
ALSO BE A PRIME TIME FOR LIGHT RAIN MONDAY NIGHT, WITH THE COOLER
SURFACE AIR AND A PASSING UPPER WAVE. THIS UPPER FORCING WILL
SLIDE OFF TO THE SOUTHEAST BY TUESDAY AFTERNOON, TAKING THE
PRECIPITATION WITH IT.
THE SOUTHWEST FLOW WILL BRING WARM TEMPERATURES BACK INTO WESTERN
KANSAS WEDNESDAY. MAX TEMPERATURES BOTH WEDNESDAY AND THURSDAY
WILL REACH THE MID TO UPPER 80S, MAKING IT FEEL MORE LIKE SUMMER
AGAIN. A LEE SIDE TROUGH IN FAR WESTERN KANSAS WEDNESDAY AFTERNOON
WILL BRING A SLIGHT CHANCE FOR SHOWERS AND ISOLATED THUNDERSTORMS
THERE. THERE IS ANOTHER SHORT WAVE CUTTING EAST THROUGH
SOUTHWESTERN KANSAS ON WEDNESDAY NIGHT, AND LOWER END POPS FOR
SHOWERS AND ISOLATED THUNDERSTORMS WILL EXIST WEDNESDAY NIGHT.
I ACCEPTED AND KEPT THE MIN TEMPS WHICH WERE ALREADY IN THE GRIDS,
OR THE NEW CR_EXTENDED APPLICATION GAVE. MINIMUMS WILL BASICALLY
BE IN THE 55F TO 65F DEGREE RANGE FOR THIS 3 TO 7 DAY FORECAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1203 PM CDT FRI SEP 12 2014
AN AREA OF HIGH PRESSURE AT THE SURFACE WILL BUILD ACROSS NORTHERN
AND CENTRAL KANSAS OVERNIGHT. THIS WILL RESULT IN DECREASING
NORTHERLY WINDS THIS AFTERNOON AND LIGHT WINDS OVERNIGHT GRADUALLY
VEERING TO THE EAST/SOUTHEAST TOWARDS BY DAYBREAK ON SATURDAY.
CLEARING CONDITIONS WILL DEVELOP FROM NORTH OF SOUTH LATE TODAY
BEHIND AN UPPER LEVEL TROUGH WHICH WILL MOVE OUT OF THE NORTHERN
PLAINS LATE THIS AFTERNOON INTO THE MID/UPPER MISSISSIPPI VALLEY.
BASED ON BUFR SOUNDINGS AND HRRR MVFR CONDITIONS ARE EXPECTED TO
IMPROVE INTO THE VFR CATEGORY BETWEEN 21Z FRIDAY AND 00Z SATURDAY.
SOME PATCHY FOG WILL BE POSSIBLE AROUND DAYBREAK GIVEN CLEAR SKIES
AND LIGHT EAST/SOUTHEAST WINDS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 37 67 49 79 / 0 0 10 0
GCK 36 68 49 79 / 0 0 0 0
EHA 41 72 52 80 / 0 0 10 0
LBL 39 71 53 81 / 0 0 10 0
HYS 35 64 47 77 / 0 0 10 0
P28 39 68 52 79 / 0 0 10 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURGERT
LONG TERM...BURKE
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1211 PM CDT FRI SEP 12 2014
...UPDATED SYNOPSIS AND AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 1203 PM CDT FRI SEP 12 2014
AT 12Z FRIDAY A -25C 500MB TROUGH EXTENDED FROM SOUTHEAST WYOMING
TO THE WESTERLY GREAT LAKES. A 300MB JET STRETCHED FROM NEBRASKA
TO QUEBEC. A 700MB BAROCLINIC ZONE WAS LOCATED NEAR THE RIGHT EXIT
REGION OF THIS UPPER LEVEL JET AND EXTENDED FROM EAST CENTRAL
COLORADO TO SOUTHWEST IOWA. A SURFACE TO 850MB HIGH WAS CENTERED
OVER FAR WESTERN NEBRASKA/SOUTHEAST WYOMING AT 12Z FRIDAY AND
SURFACE TEMPERATURES THIS MORNING IN THIS REGION WERE MAINLY IN
THE LOW TO MID 30S. 850MB TEMPERATURES RANGED FROM +10C AT
AMARILLO TO -1C AT NORTH PLATTE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 205 AM CDT FRI SEP 12 2014
SHORT TERM MODELS INDICATE AN UPPER LEVEL SHORTWAVE TROUGH TURNING
EASTWARD ACROSS THE CENTRAL PLAINS EARLY TODAY PROVIDING INCREASED
CHANCES FOR PRECIP ACROSS PORTIONS OF WESTERN AND CENTRAL KANSAS
THROUGH MID DAY. AS THE SHORTWAVE TRANSITIONS THROUGH, A STRONG
+90KT UPPER LEVEL JET WITH A RIGHT FRONT ENTRANCE REGION SET UP
ACROSS CENTRAL AND PORTIONS OF WESTERN KANSAS, WILL GRADUALLY
SHIFT EASTWARD THROUGH THIS AFTERNOON. MEANWHILE, THE NAM AND GFS
SHOW H7 FRONTOGENETIC BANDING MIGRATING EASTWARD ACROSS WESTERN
KANSAS THIS MORNING IN WAKE OF SECONDARY FRONT PUSHING SOUTH
ACROSS THE AREA. AS A RESULT, ONGOING SCATTERED SHOWERS MOVING
EAST ACROSS WESTERN KANSAS EARLY THIS MORNING WILL TRACK FURTHER
EAST INTO CENTRAL KANSAS THROUGH LATE MORNING WITH ANY LINGERING
PRECIP COMING TO AN END WEST TO EAST BY THIS AFTERNOON. DRIER
CONDITIONS ARE THEN EXPECTED ACROSS WESTERN KANSAS FRIDAY NIGHT AS
THE UPPER LEVEL SHORTWAVE LIFTS NORTHEAST INTO THE GREAT LAKES
REGION.
TEMPERATURES WILL REMAIN WELL BELOW NORMAL TODAY AS A SECONDARY
SURGE OF COOLER AIR MOVES SOUTHWARD INTO WESTERN KANSAS AHEAD OF A
BROAD SURFACE HIGH EDGING SOUTHEAST INTO THE CENTRAL PLAINS. THE
REINFORCED COOLER AIR MASS COMBINED WITH LINGERING PRECIP AND A
PREVAILING STRATUS DECK WILL KEEP TEMPERATURES FROM CLIMBING ABOVE
THE LOWER TO MID 50S(F) TODAY WITH TEMPERATURES LIKELY FALLING
INTO THE 40S(F) IN SOME LOCATIONS BY THIS AFTERNOON AS THE COLDER
AIR SETTLES IN. FOR TONIGHT, SURFACE HIGH PRESSURE ACROSS WESTERN
KANSAS WILL KEEP THE MUCH COOLER AIR MASS LOCKED IN PLACE ACROSS
WESTERN KANSAS. ALONG WITH THE HELP OF LIGHTER WINDS AND CLEARING
SKIES, LOOK FOR LOWS DROPPING DOWN INTO THE MID TO UPPER 30S(F)
ACROSS MUCH OF CENTRAL AND SOUTHWEST KANSAS WITH NEAR 40F STILL
POSSIBLE CLOSER TO THE OKLAHOMA BORDER. WITH AMPLE RESIDUAL
MOISTURE PRESENT, THE POTENTIAL FOR FROST DEVELOPMENT WILL EXIST
EARLY SATURDAY MORNING ACROSS WEST CENTRAL AND CENTRAL KANSAS AND
POSSIBLY FURTHER SOUTH INTO NORTHERN PORTIONS OF SOUTHWEST KANSAS.
FROST HEADLINES MAY NEED TO BE CONSIDERED BY THE FOLLOWING SHIFT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 302 AM CDT FRI SEP 12 2014
THIS EXTENDED PERIOD WILL BE DOMINATED BY A SERIES OF UPPER LEVEL
TROUGHS AND WAVES. THE FIRST WILL COME ALONG ABOUT LATE SUNDAY
NIGHT, DRAGGING A COLD FRONT DOWN THROUGH THE CENTRAL PLAINS WITH
IT. SATURDAY AND SUNDAY WILL GO THROUGH A SLOW WARMING TREND, WITH
MID 60S TO LOWER 70S FOR HIGHS ON SATURDAY, FOLLOWED BY HIGHS ON
SUNDAY IN THE UPPER 70S TO NEAR 80F DEGREE RANGE. THE FLOW ALOFT
DURING THE WEEKEND WILL BE ZONAL, WITH A BROAD HIGH PRESSURE RIDGE
TO OUR SOUTH AND AN UPPER TROUGH TO OUR NORTHEAST. THE IS A TROUGH
AND ASSOCIATED COLD FRONT SWEEPING DOWN FROM THE NORTH SUNDAY
NIGHT INTO MONDAY, WHICH WILL BRING A CHANCE FOR THUNDERSTORMS TO
SOUTHWESTERN KANSAS. I DID NOT GO VERY HIGH WITH POPS MONDAY,
EXCEPT FOR 30 TO 40 PERCENT IN OUR SOUTHEAST ZONES NEAR BARBER
AND PRATT COUNTIES, WHERE MOISTURE WILL BE THE GREATEST. IT WILL
ALSO BE A PRIME TIME FOR LIGHT RAIN MONDAY NIGHT, WITH THE COOLER
SURFACE AIR AND A PASSING UPPER WAVE. THIS UPPER FORCING WILL
SLIDE OFF TO THE SOUTHEAST BY TUESDAY AFTERNOON, TAKING THE
PRECIPITATION WITH IT.
THE SOUTHWEST FLOW WILL BRING WARM TEMPERATURES BACK INTO WESTERN
KANSAS WEDNESDAY. MAX TEMPERATURES BOTH WEDNESDAY AND THURSDAY
WILL REACH THE MID TO UPPER 80S, MAKING IT FEEL MORE LIKE SUMMER
AGAIN. A LEE SIDE TROUGH IN FAR WESTERN KANSAS WEDNESDAY AFTERNOON
WILL BRING A SLIGHT CHANCE FOR SHOWERS AND ISOLATED THUNDERSTORMS
THERE. THERE IS ANOTHER SHORT WAVE CUTTING EAST THROUGH
SOUTHWESTERN KANSAS ON WEDNESDAY NIGHT, AND LOWER END POPS FOR
SHOWERS AND ISOLATED THUNDERSTORMS WILL EXIST WEDNESDAY NIGHT.
I ACCEPTED AND KEPT THE MIN TEMPS WHICH WERE ALREADY IN THE GRIDS,
OR THE NEW CR_EXTENDED APPLICATION GAVE. MINIMUMS WILL BASICALLY
BE IN THE 55F TO 65F DEGREE RANGE FOR THIS 3 TO 7 DAY FORECAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1203 PM CDT FRI SEP 12 2014
AN AREA OF HIGH PRESSURE AT THE SURFACE WILL BUILD ACROSS NORTHERN
AND CENTRAL KANSAS OVERNIGHT. THIS WILL RESULT IN DECREASING
NORTHERLY WINDS THIS AFTERNOON AND LIGHT WINDS OVERNIGHT GRADUALLY
VEERING TO THE EAST/SOUTHEAST TOWARDS BY DAYBREAK ON SATURDAY.
CLEARING CONDITIONS WILL DEVELOP FROM NORTH OF SOUTH LATE TODAY
BEHIND AN UPPER LEVEL TROUGH WHICH WILL MOVE OUT OF THE NORTHERN
PLAINS LATE THIS AFTERNOON INTO THE MID/UPPER MISSISSIPPI VALLEY.
BASED ON BUFR SOUNDINGS AND HRRR MVFR CONDITIONS ARE EXPECTED TO
IMPROVE INTO THE VFR CATEGORY BETWEEN 21Z FRIDAY AND 00Z SATURDAY.
SOME PATCHY FOG WILL BE POSSIBLE AROUND DAYBREAK GIVEN CLEAR SKIES
AND LIGHT EAST/SOUTHEAST WINDS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 50 38 67 49 / 70 0 0 10
GCK 49 35 68 49 / 70 0 0 0
EHA 49 42 72 52 / 70 0 0 10
LBL 52 41 71 53 / 70 0 0 10
HYS 50 37 64 47 / 60 0 0 10
P28 55 42 68 52 / 50 0 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...JJOHNSON
LONG TERM...BURKE
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
348 PM CDT FRI SEP 12 2014
.DISCUSSION...
OUR WEAK COLD FRONT REMAINS STATIONARY JUST S OF THE I-20 CORRIDOR
OF E TX/N LA THIS AFTERNOON...WITH A LARGE SUCKER HOLE RECENTLY
OPENING UP ACROSS NW LA. TEMPS IN THESE AREAS HAVE WARMED INTO THE
LOWER/MID 80S THIS AFTERNOON...BUT TEMPS REMAIN MUCH COOLER UNDER
THE LOW STRATUS FARTHER W AND N. AS EXPECTED...SCT CONVECTION HAS
DEVELOPED ALONG THE FRONTAL ZONE OVER DEEP E TX...WITH THE WEAK
SEABREEZE APPROACHING THIS AREA AS WELL AS WCNTRL LA FROM SE TX/SW
LA. BELIEVE THAT THIS CONVECTION WILL CONTINUE THROUGH A PORTION
OF THIS EVENING BEFORE DIMINISHING WITH THE LOSS OF
HEATING/INSTABILITY...WITH THE FRONTAL BNDRY EXPECTED TO SLOWLY
DRIFT BACK S ACROSS THIS AREA AND THE SRN SECTIONS OF NCNTRL LA
THIS EVENING/OVERNIGHT. THE HRRR AND TO SOME EXTENT...THE 12Z WRF
DOES INDICATE THE ONGOING CONVECTION POSSIBLY BUILDING BACK A
LITTLE FARTHER NNE TO NEAR/JUST S OF THE I-20 CORRIDOR OF E TX/NW
LA THIS EVENING...WITH ONLY ISOLATED -SHRA EXPECTED FARTHER N
CLOSER TO THE WEAK 850MB TROUGH AS IT REMAINS JUST N OF THE REGION
OVER SE OK/WRN AND CNTRL AR. DID MAINTAIN HIGH CHANCE POPS FOR
AREAS NEAR/S OF THE FRONT THIS EVENING...LOWERING POPS A TAD LATE
AS THE CONVECTION SHOULD WANE ONCE OVERALL FORCING WEAKENS. SHOULD
SEE A WIDE RANGE IN MIN TEMPS OVERNIGHT GIVEN THE SHALLOW NATURE
OF THE POST-FRONTAL AIR MASS...WITH TEMPS POSSIBLY FALLING INTO
THE UPPER 50S OVER SE OK/SW AR.
THE WEAK COLD FRONT IS EXPECTED TO NEAR THE COAST AROUND 12Z
SATURDAY...WITH THE POST-FRONTAL STRATUS HOLDING TOUGH THROUGH THE
DAY. GIVEN THE DEPTH OF THE MOISTURE IN PLACE...DID INSERT SLIGHT
CHANCE POPS AREAWIDE SATURDAY AS ANY WEAK FORCING WILL EASILY
RESULT IN -SHRA DEVELOPMENT...WITH DAYTIME TEMPS ONLY RISING 10
DEGREES OR SO FROM THE MORNING LOWS. THE LOW STRATUS SHOULD BEGIN
TO SLOWLY LIFT SUNDAY...POSSIBLY SCATTERING OUT IN THE AFTERNOON
OVER PORTIONS OF THE REGION. THIS SHOULD RESULT IN MODERATING
TEMPS...ALTHOUGH SFC RIDGING IN PLACE WILL MAINTAIN ABNORMALLY LOW
DEWPOINTS AND COMFORTABLE RH/S FOR THIS TIME OF YEAR. SHOULD BEGIN
TO SEE A RETURN OF HIGHER RH/S BY TUESDAY AS THE BROAD UPPER LEVEL
LOW/TROPICAL WAVE...NOW OVER SRN FL...BEGINS TO SHIFT W ACROSS THE
GULF OF MX THIS WEEKEND AND POSSIBLY IMPACT THE TX COAST.
ATTM...ENOUGH SHEAR ALOFT SHOULD KEEP THIS SYSTEM FROM
INTENSIFYING THIS WEEKEND AND EARLY NEXT WEEK...ALTHOUGH IT WILL
HELP ENHANCE THE SEABREEZE AS IT MOVES INLAND ACROSS SE AND DEEP E
TX/SRN AND CNTRL LA TUESDAY. IN ADDITION...A SHORTWAVE IN THE NW
FLOW ALOFT WILL DROP SE ACROSS THE REGION TUESDAY AS WELL...WHICH
COULD FURTHER ENHANCE FORCING OVER THE SRN SECTIONS OF THE REGION.
HAVE INCREASED POPS TO MID CHANCE S OF I-20 TUESDAY...WITH
CONVECTION DIMINISHING TUESDAY NIGHT/WEDNESDAY AS DRIER AIR ALOFT
MIXES SE IN WAKE OF THIS SHORTWAVE. A DRY NW FLOW LOOKS TO PERSIST
THROUGHOUT THE REMAINDER OF THE WEEK AS UPPER LEVEL RIDGING BUILDS
OVER THE DESERT SW AND THE ROCKIES. TEMPS SHOULD BE NEAR CLIMO
THROUGH THE PERIOD AS WELL.
PRELIMS TO FOLLOW BELOW...
15
&&
.PREV DISCUSSION... /ISSUED 1222 PM CDT FRI SEP 12 2014/
AVIATION...
IFR CEILINGS ABOUND AT ALL SITES EXCEPT FOR LFK...FOR THEY ARE
VERY NEAR THE COLD FRONT BOUNDARY. DO NOT EXPECT CONDITIONS TO
IMPROVE MUCH THIS FORECAST PERIOD AS THE MOISTURE OVERRUNNING THE
FRONT WILL STAY IN PLACE UNTIL SATURDAY. /35/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 65 76 61 85 66 / 30 20 10 10 10
MLU 65 77 61 84 65 / 30 20 10 10 10
DEQ 59 71 57 79 62 / 30 20 10 10 10
TXK 60 72 58 81 63 / 30 20 10 10 10
ELD 61 74 57 81 62 / 30 20 10 10 10
TYR 63 74 61 85 68 / 40 20 10 10 10
GGG 65 75 61 85 66 / 40 20 10 10 10
LFK 69 80 64 88 68 / 50 30 10 10 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
15
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1222 PM CDT FRI SEP 12 2014
.AVIATION...
IFR CEILINGS ABOUND AT ALL SITES EXCEPT FOR LFK...FOR THEY ARE
VERY NEAR THE COLD FRONT BOUNDARY. DO NOT EXPECT CONDITIONS TO
IMPROVE MUCH THIS FORECAST PERIOD AS THE MOISTURE OVERRUNNING THE
FRONT WILL STAY IN PLACE UNTIL TOMORROW. /35/
&&
.PREV DISCUSSION... /ISSUED 1153 AM CDT FRI SEP 12 2014/
DISCUSSION...
A WEAK COLD FRONT REMAINS DRAPED FROM W TO E ACROSS THE REGION
THIS MORNING...AND SHOWS UP WELL VIA THE LOW STRATUS FIELD ON THE
VISIBLE SATELLITE IMAGERY. THE LEADING EDGE OF THIS BNDRY EXTENDS
FROM NEAR A ACT...TO PSN/JSO...TO RFI...THEN SE TO NEAR A IER TO
ESF LINE AS OF 16Z...WITH THE SHORT TERM PROGS HOLDING IT NEARLY
STATIONARY THROUGH THE AFTERNOON BEFORE SLOWLY MIXING IT S JUST
BEFORE SUNSET. MEANWHILE...SCT TO NUMEROUS AREAS OF SHRA WITH
EMBEDDED TSRA CONTINUE N OF THE FRONT ACROSS EXTREME NE TX/SW
AR/SE OK...WHERE 850MB THETA-E RIDGING HAS DEVELOPED JUST AHEAD OF
THE 850MB TROUGH OVER SE OK/SW AR. THIS RAINFALL IS BEING FURTHER
ENHANCED FROM ELEVATED MOISTURE FROM TS ODILE ALONG THE WRN MX
COAST...WHICH IS ROUNDING THE FLAT UPPER RIDGING OVER SE TX/GULF
COAST REGION. FORTUNATELY...RAINFALL RATES HAVE NOT BEEN
EXCESSIVELY HEAVY THIS MORNING BUT LOOKS TO PERSIST THROUGH AT
LEAST MID-AFTERNOON /PER THE 12Z PROGS AND LATEST HRRR RUNS/
BEFORE DIMINISHING. MEANWHILE...A WEAK SEABREEZE OVER SE TX/SW LA
IS BEING ENHANCED BY AN UPPER LOW OVER ERN OLD MX...WITH SCT
CONVECTION HAVING ALREADY DEVELOPED ALONG THE COAST. VISIBLE
SATELLITE IMAGE INDICATES THAT TOWERS HAVE DEVELOPED JUST AHEAD OF
THE FRONT OVER DEEP E TX/WCNTRL LA...WITH 2500-3000 J/KG OF SBCAPE
HAVING DEVELOPED. DEEP LAYER SHEAR REMAINS QUITE WEAK...THUS THE
CONVECTION SHOULD BE PULSY BUT STILL CAPABLE OF BRIEF DOWNPOURS
GIVEN THE PW/S IN EXCESS OF 2 INCHES EVIDENT ON THE REGIONAL 12Z
RAOBS. BELIEVE THAT THE CONVECTION OVER SE TX SHOULD BECOME MORE
NUMEROUS THIS AFTERNOON AS IT INTERACTS WITH THE NEARLY STATIONARY
FRONT.
HAVE HAD TO MAKE QUITE A FEW CHANGES TO THE FORECAST FOR THE LATE
MORNING UPDATE...LOWERING POPS TO MID CHANCE ALONG THE I-20
CORRIDOR OF E TX/N LA...WHILE ALSO TAPERING POPS A BIT FARTHER N
BUT BELOW I-30 INTO EXTREME SRN AR. DID MAINTAIN LIKELY POPS TODAY
FOR THE NRN ZONES AS WELL AS DEEP E TX/SRN SECTIONS OF NCNTRL
LA...WITH ANY HEAVY RAIN THREAT BRIEF AND LOCALIZED. ALSO HAD TO
LOWER TEMPS CONSIDERABLY N OF THE STALLED FRONT...ESPECIALLY ALONG
THE I-20 CORRIDOR OF E TX/N LA. AREAS NEAR/S OF THE FRONT OVER
DEEP E TX/NCNTRL LA ARE ALREADY NEARING THEIR FORECAST MAX
TEMPS...BUT WITH CONVECTION EXPECTED TO AFFECT THESE AREAS BY
EARLY AFTERNOON...TEMPS SHOULD NOT WARM MUCH FURTHER BEFORE THE
CONVECTION SETS IN.
ZONE UPDATE ALREADY OUT...GRIDS WILL BE AVAILABLE SHORTLY.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 81 66 80 65 86 / 40 30 20 10 10
MLU 81 68 80 63 83 / 40 50 20 10 10
DEQ 71 61 73 59 79 / 70 30 10 10 10
TXK 73 62 76 60 81 / 60 30 10 10 10
ELD 74 64 75 60 80 / 50 30 10 10 10
TYR 80 64 78 65 87 / 40 30 10 10 10
GGG 81 65 80 65 87 / 40 30 10 10 10
LFK 92 70 85 67 89 / 60 50 30 10 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1153 AM CDT FRI SEP 12 2014
.DISCUSSION...
A WEAK COLD FRONT REMAINS DRAPED FROM W TO E ACROSS THE REGION
THIS MORNING...AND SHOWS UP WELL VIA THE LOW STRATUS FIELD ON THE
VISIBLE SATELLITE IMAGERY. THE LEADING EDGE OF THIS BNDRY EXTENDS
FROM NEAR A ACT...TO PSN/JSO...TO RFI...THEN SE TO NEAR A IER TO
ESF LINE AS OF 16Z...WITH THE SHORT TERM PROGS HOLDING IT NEARLY
STATIONARY THROUGH THE AFTERNOON BEFORE SLOWLY MIXING IT S JUST
BEFORE SUNSET. MEANWHILE...SCT TO NUMEROUS AREAS OF SHRA WITH
EMBEDDED TSRA CONTINUE N OF THE FRONT ACROSS EXTREME NE TX/SW
AR/SE OK...WHERE 850MB THETA-E RIDGING HAS DEVELOPED JUST AHEAD OF
THE 850MB TROUGH OVER SE OK/SW AR. THIS RAINFALL IS BEING FURTHER
ENHANCED FROM ELEVATED MOISTURE FROM TS ODILE ALONG THE WRN MX
COAST...WHICH IS ROUNDING THE FLAT UPPER RIDGING OVER SE TX/GULF
COAST REGION. FORTUNATELY...RAINFALL RATES HAVE NOT BEEN
EXCESSIVELY HEAVY THIS MORNING BUT LOOKS TO PERSIST THROUGH AT
LEAST MID-AFTERNOON /PER THE 12Z PROGS AND LATEST HRRR RUNS/
BEFORE DIMINISHING. MEANWHILE...A WEAK SEABREEZE OVER SE TX/SW LA
IS BEING ENHANCED BY AN UPPER LOW OVER ERN OLD MX...WITH SCT
CONVECTION HAVING ALREADY DEVELOPED ALONG THE COAST. VISIBLE
SATELLITE IMAGE INDICATES THAT TOWERS HAVE DEVELOPED JUST AHEAD OF
THE FRONT OVER DEEP E TX/WCNTRL LA...WITH 2500-3000 J/KG OF SBCAPE
HAVING DEVELOPED. DEEP LAYER SHEAR REMAINS QUITE WEAK...THUS THE
CONVECTION SHOULD BE PULSY BUT STILL CAPABLE OF BRIEF DOWNPOURS
GIVEN THE PW/S IN EXCESS OF 2 INCHES EVIDENT ON THE REGIONAL 12Z
RAOBS. BELIEVE THAT THE CONVECTION OVER SE TX SHOULD BECOME MORE
NUMEROUS THIS AFTERNOON AS IT INTERACTS WITH THE NEARLY STATIONARY
FRONT.
HAVE HAD TO MAKE QUITE A FEW CHANGES TO THE FORECAST FOR THE LATE
MORNING UPDATE...LOWERING POPS TO MID CHANCE ALONG THE I-20
CORRIDOR OF E TX/N LA...WHILE ALSO TAPERING POPS A BIT FARTHER N
BUT BELOW I-30 INTO EXTREME SRN AR. DID MAINTAIN LIKELY POPS TODAY
FOR THE NRN ZONES AS WELL AS DEEP E TX/SRN SECTIONS OF NCNTRL
LA...WITH ANY HEAVY RAIN THREAT BRIEF AND LOCALIZED. ALSO HAD TO
LOWER TEMPS CONSIDERABLY N OF THE STALLED FRONT...ESPECIALLY ALONG
THE I-20 CORRIDOR OF E TX/N LA. AREAS NEAR/S OF THE FRONT OVER
DEEP E TX/NCNTRL LA ARE ALREADY NEARING THEIR FORECAST MAX
TEMPS...BUT WITH CONVECTION EXPECTED TO AFFECT THESE AREAS BY
EARLY AFTERNOON...TEMPS SHOULD NOT WARM MUCH FURTHER BEFORE THE
CONVECTION SETS IN.
ZONE UPDATE ALREADY OUT...GRIDS WILL BE AVAILABLE SHORTLY.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 81 66 80 65 86 / 40 30 20 10 10
MLU 81 68 80 63 83 / 40 50 20 10 10
DEQ 71 61 73 59 79 / 70 30 10 10 10
TXK 73 62 76 60 81 / 60 30 10 10 10
ELD 74 64 75 60 80 / 50 30 10 10 10
TYR 80 64 78 65 87 / 40 30 10 10 10
GGG 81 65 80 65 87 / 40 30 10 10 10
LFK 92 70 85 67 89 / 60 50 30 10 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
15
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
609 PM EDT FRI SEP 12 2014
.SYNOPSIS...
COOL WEATHER WILL CARRY THROUGH MUCH OF THE NEXT SEVEN DAYS. LOW
PRESSURE PASSING SATURDAY BRINGS THE CHANCE FOR SHOWERS...OUTSIDE
EASTERN OHIO. AFTER A PERIOD OF DRY WEATHER THANKS TO HIGH
PRESSURE...THE NEXT COLD FRONT IS PREDICTED TO CROSS TUESDAY INTO
WEDNESDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
SKIES HAVE GENERALLY CLEARED IN THE RIDGES AND IN ALL POINTS TO
THEIR EAST. AS LOW LEVEL FLOW AS TURNED A BIT MORE EASTERLY...A
HINT OF DOWNSLOPE MAY ERODE THE EASTERN EDGE OF THE STRATUS SHIELD
PRIOR TO MID-CLOUD INCREASING. SKY GRIDS WERE ADJUSTED
ACCORDINGLY...HOWEVER ONLY THE EASTERN FRINGE OF THE FORECAST AREA
IS LIKELY TO BENEFIT FROM ANY SCATTERING OUT/CLEARING...WHILE THE
STRATUS SHOULD HOLD IN THE MAJORITY OF THE AREA UNTIL THE ARRIVAL
OF A DEEPER CLOUD SHIELD. FRIES
PREVIOUS DISCUSSION FOLLOWS AND IS STILL LARGELY
APPLICABLE...CLOUDY DAY ACROSS THE PBZ CWA. MDCRS PLOT FROM PIT
CONTINUES TO SHOW A STOUT INVERSION JUST ABOVE H900.
HOWEVER...CLOUDS ARE STARTING TO ERODE A BIT FROM THE EASTERN
RIDGES...GARRETT AND TUCKER COUNTIES IN PARTICULAR ARE GETTING
SOME SUN. WHILE THIS SLOW TREND SHOULD CONTINUE FOR A FEW HOURS
WITH LBE AND DUJ BENEFITING A BIT...I AM DUBIOUS THAT MUCH CLOUD
BREAKUP WILL OCCUR FROM PIT ON WEST. RAP SOUNDINGS CONCUR WITH
THIS. IN ANY EVENT...AREAS THAT CLEAR WILL START TO SEE MID CLOUDS
INCREASE THIS EVENING IN SW FLOW ALOFT AHEAD OF NEXT SYSTEM.
MODELS ARE IN GOOD AGREEMENT ON THE SCENARIO. FAIRLY SHARP H500
SHORWAVE WILL MOVE ACROSS THE GREAT LAKES TONIGHT AND INTO SOUTHERN
QUEBEC BY 00Z SUNDAY. A WEAK SURFACE WAVE WILL FORM ALONG THE FRONT
FROM YESTERDAY AND MOVES NORTHEAST THROUGH THE CAROLINAS TONIGHT.
IN OUR CWA...INVERTED TROUGHING AT THE SURFACE WILL HELP TO PULL
DEEPER MOISTURE BACK NORTHWARD...ESPECIALLY EAST OF THE OHIO RIVER.
PWATS RISE TO AROUND 1.5 INCHES FOR A SHORT TIME SOUTH OF PIT LATE
TONIGHT. POPS LITTLE CHANGED FROM PREVIOUS SHIFT...WITH LIKELY
VALUES EAST OF HLG/PIT/FKL AND LESSER TO THE WEST. LOOKING FOR A
QUARTER TO A HALF INCH OF RAIN AT MOST ALONG THE RIDGES. THUNDER
NOT EXPECTED.
SHORTWAVE TROUGH AXIS QUICKLY ROTATES THROUGH AFTER 12Z
SATURDAY...WHICH WILL SHUNT THE DEEP MOISTURE EASTWARD BY
MIDAFTERNOON. A FEW SHOWERS MAY LINGER IN LOW LEVEL NW FLOW...BUT
EXPECTING ALL RAIN TO WRAP UP BY 00Z SUNDAY...WHEN A SURFACE HIGH
BEGINS TO ARRIVE FROM THE WEST.
BELOW SEASONAL TEMPERATURES WILL CONTINUE.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
BLDG HIGH PRES WL BRING DRY WEA THRU ERLY MON. THE HIGH WL SHIFT E
MON AFTN...WITH INCRG CLDS AHD OF THE NXT APCHG SHRTWV. TEMPS WL
CONT TO AVG BLO SEASONAL LVLS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE ADVNG SHRTWV IS EXPD TO SPAWN SHWRS MONDAY NGT AND EARLY TUES.
SFC HIGH PRES...UNDR BROAD ERN CONUS TROFG...IS THEN FORECAST TO
MAINTAIN DRY...BUT SEASONABLY COOL WEATHER FOR THE RMNDR OF THE
LONG TERM PD. LONG TERM TEMPS WERE FORECAST USING HPC GUIDANCE...
TWEAKED UPWARD VIA GFS MOS TRENDS.
&&
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
MVFR CIGS ACROSS THE BOARD CONTINUE THIS AFTERNOON. INVERSION
ALOFT IS HANGING TOUGH BUT IS STARTING TO BREAK ALONG THE RIDGES
EAST OF LBE/DUJ. THINK SOME CLEARING...AND RETURN TO VFR
CONDITIONS...WILL REACH LBE/DUJ/MGW OVER THE NEXT FEW HOURS.
FORECAST BECOMES A BIT MORE PROBLEMATIC FURTHER WEST AS MODELS
SHOW INVERSION HANGING ON HERE. FOR NOW KEEPING A HIGH MVFR/LOW
VFR CIG AT PIT/AGC/HLG THIS EVENING AND WILL WATCH TRENDS. NEXT
SHORTWAVE/WEAK SURFACE WAVE APPROACHES LATER TONIGHT AND PASSES
THROUGH SATURDAY MORNING. MVFR CIG/VIS IN SHRA MAINLY FROM PIT ON
EAST. BORDERLINE MVFR/VFR CIGS WITH LESS CHANCE OF SHRA TO THE WEST.
OUTLOOK...THURSDAY NIGHT THROUGH TUESDAY...
NEXT FRONTAL SYSTEM WITH POSSIBLE RESTRICTIONS ARRIVES MONDAY
NIGHT INTO TUESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
244 PM EDT FRI SEP 12 2014
.SYNOPSIS...
COOL WEATHER WILL CARRY THROUGH MUCH OF THE NEXT SEVEN DAYS. LOW
PRESSURE PASSING SATURDAY BRINGS THE CHANCE FOR SHOWERS...OUTSIDE
EASTERN OHIO. AFTER A PERIOD OF DRY WEATHER THANKS TO HIGH
PRESSURE...THE NEXT COLD FRONT IS PREDICTED TO CROSS TUESDAY INTO
WEDNESDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
CLOUDY DAY ACROSS THE PBZ CWA. MDCRS PLOT FROM PIT CONTINUES TO
SHOW A STOUT INVERSION JUST ABOVE H900. HOWEVER...CLOUDS ARE
STARTING TO ERODE A BIT FROM THE EASTERN RIDGES...GARRETT AND TUCKER
COUNTIES IN PARTICULAR ARE GETTING SOME SUN. WHILE THIS SLOW TREND
SHOULD CONTINUE FOR A FEW HOURS WITH LBE AND DUJ BENEFITING A
BIT...I AM DUBIOUS THAT MUCH CLOUD BREAKUP WILL OCCUR FROM PIT ON
WEST. RAP SOUNDINGS CONCUR WITH THIS. IN ANY EVENT...AREAS THAT
CLEAR WILL START TO SEE MID CLOUDS INCREASE THIS EVENING IN SW FLOW
ALOFT AHEAD OF NEXT SYSTEM.
MODELS ARE IN GOOD AGREEMENT ON THE SCENARIO. FAIRLY SHARP H500
SHORWAVE WILL MOVE ACROSS THE GREAT LAKES TONIGHT AND INTO SOUTHERN
QUEBEC BY 00Z SUNDAY. A WEAK SURFACE WAVE WILL FORM ALONG THE FRONT
FROM YESTERDAY AND MOVES NORTHEAST THROUGH THE CAROLINAS TONIGHT.
IN OUR CWA...INVERTED TROUGHING AT THE SURFACE WILL HELP TO PULL
DEEPER MOISTURE BACK NORTHWARD...ESPECIALLY EAST OF THE OHIO RIVER.
PWATS RISE TO AROUND 1.5 INCHES FOR A SHORT TIME SOUTH OF PIT LATE
TONIGHT. POPS LITTLE CHANGED FROM PREVIOUS SHIFT...WITH LIKELY
VALUES EAST OF HLG/PIT/FKL AND LESSER TO THE WEST. LOOKING FOR A
QUARTER TO A HALF INCH OF RAIN AT MOST ALONG THE RIDGES. THUNDER
NOT EXPECTED.
SHORTWAVE TROUGH AXIS QUICKLY ROTATES THROUGH AFTER 12Z
SATURDAY...WHICH WILL SHUNT THE DEEP MOISTURE EASTWARD BY
MIDAFTERNOON. A FEW SHOWERS MAY LINGER IN LOW LEVEL NW FLOW...BUT
EXPECTING ALL RAIN TO WRAP UP BY 00Z SUNDAY...WHEN A SURFACE HIGH
BEGINS TO ARRIVE FROM THE WEST.
BELOW SEASONAL TEMPERATURES WILL CONTINUE.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
BLDG HIGH PRES WL BRING DRY WEA THRU ERLY MON. THE HIGH WL SHIFT E
MON AFTN...WITH INCRG CLDS AHD OF THE NXT APCHG SHRTWV. TEMPS WL
CONT TO AVG BLO SEASONAL LVLS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE ADVNG SHRTWV IS EXPD TO SPAWN SHWRS MONDAY NGT AND EARLY TUES.
SFC HIGH PRES...UNDR BROAD ERN CONUS TROFG...IS THEN FORECAST TO
MAINTAIN DRY...BUT SEASONABLY COOL WEATHER FOR THE RMNDR OF THE
LONG TERM PD. LONG TERM TEMPS WERE FORECAST USING HPC GUIDANCE...
TWEAKED UPWARD VIA GFS MOS TRENDS.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
MVFR CIGS ACROSS THE BOARD CONTINUE THIS AFTERNOON. INVERSION
ALOFT IS HANGING TOUGH BUT IS STARTING TO BREAK ALONG THE RIDGES
EAST OF LBE/DUJ. THINK SOME CLEARING...AND RETURN TO VFR
CONDITIONS...WILL REACH LBE/DUJ/MGW OVER THE NEXT FEW HOURS.
FORECAST BECOMES A BIT MORE PROBLEMATIC FURTHER WEST AS MODELS
SHOW INVERSION HANGING ON HERE. FOR NOW KEEPING A HIGH MVFR/LOW
VFR CIG AT PIT/AGC/HLG THIS EVENING AND WILL WATCH TRENDS. NEXT
SHORTWAVE/WEAK SURFACE WAVE APPROACHES LATER TONIGHT AND PASSES
THROUGH SATURDAY MORNING. MVFR CIG/VIS IN SHRA MAINLY FROM PIT ON
EAST. BORDERLINE MVFR/VFR CIGS WITH LESS CHANCE OF SHRA TO THE WEST.
OUTLOOK...THURSDAY NIGHT THROUGH TUESDAY...
NEXT FRONTAL SYSTEM WITH POSSIBLE RESTRICTIONS ARRIVES MONDAY
NIGHT INTO TUESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
146 PM EDT FRI SEP 12 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 324 AM EDT FRI SEP 12 2014
COOL WEATHER WILL CONTINUE INTO THE WEEKEND. WEAK LOW PRESSURE
WILL BRING SOME SHOWERS LATE TODAY THROUGH TONIGHT. THE HIGH
PRESSURE BUILDS IN FOR SATURDAY AND SUNDAY. SOME FROST IS EXPECTED
NORTH OF GRAND RAPIDS SATURDAY NIGHT.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH SUNDAY EVENING)
ISSUED AT 1121 AM EDT FRI SEP 12 2014
LITTLE QUESTION THERE WILL BE RAIN ACROSS THE CWA TONIGHT THANKS A
CLOSING OFF UPPER LOW. THE BEST DYNAMICS ARE OVER CENTRAL AND
NORTHERN LOWER MICHIGAN... SO THAT IS WHERE IT BELIEVE THE HEAVIEST
RAIN WILL BE. NEARLY ALL OF OUR CWA WILL GET RAIN FROM THIS
SYSTEM. BASED ON THE LATEST HRRR AND LOOKING AT CONDENSATION
PRESSURE DEFICITS FROM THE NAM 12Z RUN... IT WOULD SEEM THE RAIN
MAY START AS EARLY AS 3-4 PM NEAR ROUTE 10 BUT NOT REACH I-96 TILL
NEAR US-131 BY 8-9 PM. I UPDATED THE GRIDS TO REFLECT THIS TIMING.
AS A SIDE NOTE SEEMS WE WILL GET A NORTH TO SOUTH MID LAKE
ENHANCED PRECIPITATION BAND BUT THAT SHOULD STAY OFF SHORE THROUGH
THE NIGHT DUE TO THE NORTH WINDS DURING THE EVENT TONIGHT. HOWEVER
THE BAND MAY TOUCH PARTS OF EXTREME WESTERN MASON COUNTY TOWARD
MORNING. IF IT DOES EXPECT A PERIOD OF HEAVIER RAIN SHOWERS.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 324 AM EDT FRI SEP 12 2014
THE FOCUS OF THE LONG TERM IS CENTERED ON THE MON/MON NIGHT TIME
FRAME WHEN OUR BEST CHC FOR PCPN WILL BE.
THE DRY WEATHER FOR THE LATTER HALF OF THE UPCOMING WEEKEND WILL
GRADUALLY COME TO AN END LATE SUN NIGHT AND MON ACROSS THE AREA. WE
WILL SEE A COLD FRONT DROP INTO THE AREA AT THAT TIME AS A LONG WAVE
TROUGH ACROSS CENTRAL AND EASTERN CANADA SLIPS SOUTH INTO THE AREA.
PCPN ALONG THE FRONT IS INITIALLY A BIT SPARSE...HOWEVER THIS LOOKS
TO CHANGE AS A STRONG SHORT WAVE ROUNDING THE BASE OF THE LONG WAVE
TROUGH WILL INTERACT WITH THE FRONT ON MON AND MON EVENING.
RAIN WILL COME TO AN END ACROSS THE ENTIRE AREA BY 12Z TUE AS THE
SHORT WAVE TROUGH AXIS MOVES EAST OF THE CWFA. DRY WEATHER IS THEN
LIKELY TO HOLD FOR THE REMAINDER OF THE WEEK. WE WILL SEE A COOL NW
FLOW HOLD IN ACROSS THE AREA FOR THE REMAINDER OF THE WEEK. THE GOOD
THING IS THAT WE WILL BE IMMEDIATELY DOWNSTREAM FROM THE LONG WAVE
UPPER RIDGE AXIS ACROSS THE ROCKIES. THE SUBSIDENCE DOWNSTREAM FROM
THE RIDGE WILL KEEP THE WEATHER QUIET AND COOL. THE RIDGE GETS
FLATTENED A BIT BY THE END OF THE PERIOD AS ENERGY DIVING SOUTH FROM
CANADA TRIES TO MOVE IN. THE UPPER JET WILL REMAIN NORTH OF THE AREA
AND WILL HOLD A COLD FRONT ACROSS LAKE SUPERIOR UP THERE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 146 PM EDT FRI SEP 12 2014
AS MENTIONED IN THE PREVIOUS DISCUSSION...EXPECT MVFR CIGS TO
SPREAD SOUTHEAST THIS AFTERNOON AND TONIGHT WITH AN AREA OF MOSTLY
LIGHT RAIN. ALTHOUGH NOT ADVERTISED AT ALL OF THE TERMINALS...
CEILINGS COULD DROP BELOW THE FUEL ALTERNATE THRESHOLD OF 2000 FT
AGL. IFR CEILINGS ARE ALSO NOT OUT OF THE QUESTION AT MKG AFTER
06Z. OVERALL...THERE ARE FEWER CONCERNS ABOUT RESTRICTIONS TO
VISIBILITY.
&&
.MARINE...
ISSUED AT 1121 AM EDT FRI SEP 12 2014
I ADDED WATER SPOUTS TO THE NEAR SHORE FORECAST FROM LATE
AFTERNOON INTO MID MORNING SATURDAY BASED ON THE CONVECTIVE DEPTH
BEING BETWEEN 10000 FT AND 15000 FT AT MID LAKE... USING LAKE
TEMP TO 850 TEMP DIFFERENCES BETWEEN 15C AND 18C. WINDS WILL NOT BE
STRONG ENOUGH FOR SCA. IN SUPPORT OF THAT...BEACH CAMS AT 11 AM SHOW
LITTLE IN THE WAY OF SIGNIFICANT WAVE ACTION. THE PORT SHELDON HAS
SHOWN 1 TO 1.3 FOOT WAVES OVER THE PAST SEVERAL HOURS.
&&
.HYDROLOGY...
ISSUED AT 324 AM EDT FRI SEP 12 2014
NO HYDRO ISSUES EXPECTED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS...OSTUNO
SHORT TERM...WDM
LONG TERM...NJJ
AVIATION...TJT
HYDROLOGY...OSTUNO
MARINE...WDM
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
541 PM CDT Fri Sep 12 2014
.SHORT TERM: (Through Tonight)
Issued at 236 PM CDT Fri Sep 12 2014
Cloud cover continues to cover the area this afternoon as stratus is
trapped under a low level inversion and mid-high level clouds are
streaming in ahead of a mid level trough. There has been some light
rain associated with the mid-level trough moving across northern
Missouri early this afternoon, but it`s coverage has been limited.
Latest runs of the RAP and HRRR still show some redevelopment of
some light rain over western Missouri this afternoon and this
evening ahead of the upper trough that will move across the CWA this
evening. Then expect clearing of the clouds from north to south
after 06Z as the upper trough moves to the east allowing subsidence
to set in. Drier air will move into the low levels as the inversion
weakens which should allow the low level clouds to move out.
Temperatures should fall close to agreeable MOS guidance for lows
once skies begin to clear with the light northeasterly winds.
Britt
.LONG TERM: (Saturday through Next Friday)
Issued at 236 PM CDT Fri Sep 12 2014
(Saturday through Monday)
Overall, mdls are in good agreement thru this period. Period begins
with a large sfc ridge settling across the region. This ridge will
keep temps around 15 degrees below seasonal average despite ample
insolation. As the ridge retreats, the approaching trof and sfc fnt
will bring another chance for precip to the region late in the
period. Some minor differences in timing are apparent among the mdl
guidance. Will keep PoPs lower except where mdls are in agreement.
(Tuesday through Friday)
Not much change from the prev forecast. Mdls remain in good
agreement overall thru the period with respect to mass fields
anyway. Sfc ridge builds into the region on Tues with precip coming
to an end Mon night. Cool temps will prevail thru mid week, tho not
as cool as this weekend. Mdls differ regarding precip chances for
late Wed into Thurs. The ECMWF is more robust with nocturnal
convection developing along a stationary fnt across the region. The
GFS would suggest height rising with the sfc ridge still holding on
into the area. Have kept PoPs low given the uncertainty forecasting
mesoscale features on day 7.
As for temps, have trended twd the warmer guidance thru the period
given heights over the region.
Tilly
&&
.AVIATION: (For the 00z TAFs through 00z Saturday Evening)
Issued at 534 PM CDT Fri Sep 12 2014
An extensive area of MVFR stratus/stratocumulus was in place
across the region at TAF issuance. Although drier air will be
working into the region overnight, there is still a lot of
moisture trapped below an inversion. This suggests that clouds
will be slow to clear even with the drier air. On the other hand,
recent satellite imagery has shown that upstream stratocu was
breaking up over IA/NE, and it is possible that cigs may clear
earlier than expected. Ceilings could fall to IFR at times
overnight until the drier air arrives. Intermittent light drizzle
or light rain may also occur over the next several hours.
Initially northerly winds will back slightly overnight then veer
tomorrow.
Specifics for KSTL: It is likely that MVFR ceilings will persist
overnight. Ceilings should rise by tomorrow morning at the latest
due to diurnal mixing and drier low-level air. Initially northerly
winds will back slightly overnight then veer tomorrow and become
easterly towards the end of the valid TAF period.
Kanofsky
&&
.CLIMATE:
Issued at 236 PM CDT Fri Sep 12 2014
Record Lows This Weekend:
STL COU UIN
13 43(1975) 33(1902) 33(1902)
14 46(1996) 40(1892) 38(1996)
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
239 PM CDT Fri Sep 12 2014
.SHORT TERM: (Through Tonight)
Issued at 236 PM CDT Fri Sep 12 2014
Cloud cover continues to cover the area this afternoon as stratus is
trapped under a low level inversion and mid-high level clouds are
streaming in ahead of a mid level trough. There has been some light
rain associated with the mid-level trough moving across northern
Missouri early this afternoon, but it`s coverage has been limited.
Latest runs of the RAP and HRRR still show some redevelopment of
some light rain over western Missouri this afternoon and this
evening ahead of the upper trough that will move across the CWA this
evening. Then expect clearing of the clouds from north to south
after 06Z as the upper trough moves to the east allowing subsidence
to set in. Drier air will move into the low levels as the inversion
weakens which should allow the low level clouds to move out.
Temperatures should fall close to agreeable MOS guidance for lows
once skies begin to clear with the light northeasterly winds.
Britt
.LONG TERM: (Saturday through Next Friday)
Issued at 236 PM CDT Fri Sep 12 2014
(Saturday through Monday)
Overall, mdls are in good agreement thru this period. Period begins
with a large sfc ridge settling across the region. This ridge will
keep temps around 15 degrees below seasonal average despite ample
insolation. As the ridge retreats, the approaching trof and sfc fnt
will bring another chance for precip to the region late in the
period. Some minor differences in timing are apparent among the mdl
guidance. Will keep PoPs lower except where mdls are in agreement.
(Tuesday through Friday)
Not much change from the prev forecast. Mdls remain in good
agreement overall thru the period with respect to mass fields
anyway. Sfc ridge builds into the region on Tues with precip coming
to an end Mon night. Cool temps will prevail thru mid week, tho not
as cool as this weekend. Mdls differ regarding precip chances for
late Wed into Thurs. The ECMWF is more robust with nocturnal
convection developing along a stationary fnt across the region. The
GFS would suggest height rising with the sfc ridge still holding on
into the area. Have kept PoPs low given the uncertainty forecasting
mesoscale features on day 7.
As for temps, have trended twd the warmer guidance thru the period
given heights over the region.
Tilly
&&
.AVIATION: (For the 18z TAFs through 18z Saturday Afternoon)
Issued at 133 PM CDT Fri Sep 12 2014
Ceilings are expected to gradually increase above 2000 ft this
evening. Some light rain is expected to move across the area into
this evening, with most of this rain moving across northern
Missouri into central Illinois. The most likely TAF to be affected
by light rain will be Quincy. Then drier air moving into the area
overnight which will cause ceilings to climb above 3000 feet from
north to south. Dry and VFR conditions are then expected at the
terminals after 09Z.
Specifics for KSTL: Ceilings are expected to climb above 2000 ft
this afternoon and then become VFR tonight. There is some chance
for light rain between 00-06Z, but confidence is not high enough
to include in the TAF at this time. Dry and VFR conditions are
expected after 09Z.
Britt
&&
.CLIMATE:
Issued at 236 PM CDT Fri Sep 12 2014
Record Lows This Weekend:
STL COU UIN
13 43(1975) 33(1902) 33(1902)
14 46(1996) 40(1892) 38(1996)
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 47 66 48 72 / 20 0 0 0
Quincy 40 63 43 69 / 30 0 0 0
Columbia 41 65 43 72 / 30 0 0 5
Jefferson City 43 66 43 73 / 30 0 0 5
Salem 46 66 45 71 / 20 0 0 0
Farmington 44 66 40 72 / 20 0 0 0
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1246 PM CDT FRI SEP 12 2014
.SYNOPSIS...
ISSUED AT 337 AM CDT FRI SEP 12 2014
STRONG HIGH HOLDS OVER THE SOUTHERN CONUS. MAINLY ZONAL FLOW FROM
THE MISSOURI VALLEY THROUGH THE EAST COAST. PROGRESSIVE TROUGH OVER
THE NORTHERN PLAINS AND WEAK RIDGING INTO THE PACIFIC NORTHWEST.
&&
.UPDATE...
ISSUED AT 1021 AM CDT FRI SEP 12 2014
MORNING TEMPS ON THE RISE SO ALLOWED FROST/FREEZE HEADLINE TO
EXPIRE ACROSS THE NORTHWEST. NO CHANGE TO THE FROST HEADLINE FOR
THE SOUTHEAST CWA TONIGHT. COLD AIR ALOFT SHOULD COMBINE WITH
WARMING TEMPS ACROSS N CENTRAL...AS SKIES ARE CLEARING THERE TO
PRODUCE STEEP AFTERNOON LAPSE RATES. CLOUDS SHOULD QUICKLY FORM
AND EVEN COULD SEEM SOME SPRINKLES OR LIGHT RAIN SHOWERS. NAM AND
THE HRRR SUPPORT THE LIGHT RAIN SHOWERS PRODUCING SOME POCKETS OF
QPF.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 337 AM CDT FRI SEP 12 2014
MODELS IN GOOD AGREEMENT AND WILL USE BLEND FOR THE FORECAST. MAIN
FORECAST CONCERN WILL BE ENDING OF PRECIPITATION AND PTYPE WITH
HIGHLIGHTS FOR FROST IN THE NORTHWEST THIS MORNING AND THEN FROST IN
THE FORECAST EARLY SATURDAY MORNING.
PRECIPITATION SOUTH OF A LINE FROM AINSWORTH TO OSHKOSH THIS MORNING.
MOST AREAS REPORTING RAIN THIS MORNING BUT SOME AREAS OF DRIZZLE AND
SIDNEY REPORTING SNOW WITH TEMPERATURES RIGHT AROUND FREEZING.
CEILINGS LIFTING TO THE NORTH AND SOME CLEARING OVER NORTHWEST SOUTH
DAKOTA. CLEARING LINE IS MOVING TO THE SOUTHEAST AROUND 20 KTS AND
SHOULD BE THROUGH KVTN MID MORNING. 1037MB SURFACE HIGH CENTERED
OVER KCDR THIS MORNING WITH 850MB TEMPERATURES AROUND -1C.
TEMPERATURES OVER NORTHWEST IN THE MID 30S WITH LIGHT NORTHERLY
WINDS WILL CONTINUE FREEZE WARNING FOR SHERIDAN COUNTY AND FROST
ADVISORY INTO THE WESTERN SANDHILLS. CLEARING SKIES THIS MORNING AND
PRECIPITATION ENDING AROUND NOON. MOST AREAS WILL SEE TEMPERATURES
IN THE 50S THIS AFTERNOON.
TONIGHT THE SURFACE HIGH WILL MOVE INTO SOUTH CENTRAL NEBRASKA WITH
SURFACE WINDS OVER WESTERN NEBRASKA FROM THE SOUTH UNDER CLEAR
SKIES. TEMPERATURES INTO THE 30S. HAVE ISSUED A FROST ADVISORY FROM
NORTH PLATTE TO BROKEN BOW FOR EARLY SATURDAY MORNING WITH PATCHY
FROST ALONG THE NORTH PLATTE RIVER VALLEY FROM NORTH PLATTE INTO THE
PANHANDLE. THE NORTHERN SANDHILLS LOOK TO STAY IN THE UPPER 30S FOR
LOWS AS 850MB TEMPERATURES WARM OVER NIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 337 AM CDT FRI SEP 12 2014
MODELS CONTINUE TO SHOW DECENT AGREEMENT FROM THE WEEKEND THROUGH
MUCH OF NEXT WEEK...LEADING TO FAIR TO GOOD CONFIDENCE IN THIS
FORECAST PACKAGE. THE UPPER LEVEL PATTERN WILL MODERATE OVER THE
NEXT FEW DAYS AND INTO THE FIRST PART OF NEXT WEEK...HOWEVER THE
LOCAL AREA WILL REMAIN UNDER THE INFLUENCE OF NORTHWEST FLOW UNTIL
LATER IN THE FORECAST PERIOD /WEDNESDAY AND THURSDAY/. AT THIS
TIME RIDGING LOOKS TO BUILD IN OVER THE PLAINS AS A LARGE-SCALE
TROUGH PUSHES ONTO THE WEST COAST.
BEGINNING ON SATURDAY...HIGH PRESSURE AT THE SURFACE WILL BE
LOCATED EAST OF THE AREA...WITH THE AXIS FROM CENTRAL KANSAS INTO
WISCONSIN. RETURN SOUTHERLY FLOW WILL BE IN PLACE THROUGH THE DAY
OVER MUCH OF THE AREA WHICH WILL ALLOW WARM AIR ADVECTION TO TAKE
PLACE AS 850MB TEMPERATURES RISE 10 TO 13 DEGREES IN THE 24 HOURS
ENDING AT 00Z SUNDAY. THAT BEING SAID...850MB TEMPERATURES WILL
ONLY RANGE FROM 8C TO 16C AT THAT TIME...LEAVING TEMPERATURES TO
REMAIN 10 TO 20 DEGREES BELOW NORMAL ON SATURDAY.
SATURDAY NIGHT AND SUNDAY WILL SEE ANOTHER INFLUX OF COLDER AIR
COMING IN FROM THE NORTH AS A COLD FRONT TIED TO AN UPPER LEVEL
SHORTWAVE TROUGH MOVING ACROSS THE DAKOTAS PUSHES ACROSS
NEBRASKA. THIS WILL LEAD TO CONTINUED BELOW NORMAL TEMPERATURES.
LIGHT WINDS SATURDAY NIGHT WILL ALLOW THE BOUNDARY LAYER TO
DECOUPLE AND WITH DRY AIR IN PLACE TO PROMOTE MOSTLY CLEAR
SKIES...EXPECTING DECENT RADIATIONAL COOLING...WITH LOWS FALLING
TO THE UPPER 30S TO MID 40S. ON SUNDAY 60S AND LOW 70S ARE LIKELY
FOR MUCH OF THE FORECAST AREA...WHILE AREAS ACROSS FAR SOUTHWEST
NEBRASKA COULD SEE MID TO UPPER 70S AS PLENTIFUL SUNSHINE IS
EXPECTED AND THE FRONT LAYS UP JUST NORTH OF THOSE AREAS TO KEEP THE
WARMER AIR IN PLACE. MUCH OF THE AREA WILL BE UNDER LARGE SCALE
SUBSIDENCE AS THE STATE SITS BETWEEN THE CONVERGENCE OF THE POLAR
AND TROPICAL JETS. THE POLAR JET MAY DIP SOUTH ENOUGH TO BRING
SOME ENHANCED LIFT TO NORTH CENTRAL NEBRASKA AS IT WOULD BE IN THE
RIGHT ENTRANCE REGION OF THE JET STREAK ON SUNDAY. HAVE INCLUDED A
LOW CHANCE FOR RAIN IN THESE AREAS FOR SUNDAY.
A SECOND SHORTWAVE TROUGH WILL BE RIGHT BEHIND THE SATURDAY SYSTEM
WHICH IS LOOKING TO BE STRONGER AND WILL DIG FROM THE DAKOTAS INTO
THE MID MISSISSIPPI RIVER VALLEY SUNDAY NIGHT AND MONDAY. THERE IS
SOME DIFFERENCES IN TIMING WITH THE PASSAGE OF THIS IMPULSE OF
ENERGY...HOWEVER AS IT MOVES THROUGH...WITH A COLD FRONT SITUATED
WEST TO EAST ACROSS KANSAS AND HIGH PRESSURE BUILDING SOUTHEAST
FROM THE NORTHERN HIGH PLAINS AN AREA OF CONVERGENCE WILL EXIST
ROUGHLY ALONG THE NEBRASKA/KANSAS BORDER. EASTERLY UPSLOPE FLOW IN
THE LOW LEVELS WILL BRING MORE MOIST AIR INTO THIS AREA AND CROSS
SECTIONS SHOW ENOUGH LIFT TO PRODUCE PRECIPITATION AS THE SYSTEM
MOVES THROUGH. THE NAM AND ECMWF ARE A BIT QUICKER THAN THE GFS
AND PRODUCE THE RAIN SUNDAY NIGHT...WHILE THE GFS WOULD INCLUDE
THE SHOWERS DURING THE DAY MONDAY. HEDGED TOWARDS THE FASTER
SOLUTIONS SO ADDED SHOWER AND ISOLATED THUNDER CHANCES FOR SUNDAY
NIGHT IN THE SOUTHERN COUNTIES. THIS RAIN WILL PUSH SOUTH THROUGH
THE DAY MONDAY AS THE SURFACE HIGH MOVES SOUTHEAST TO BRING MORE
DRY AIR INTO THE AREA...LEAVING A DRY FORECAST FOR MONDAY.
THE REMAINDER OF THE WEEK WILL SEE A FEW PERIODIC CHANCES FOR RAIN
AS SEVERAL WEAK SHORTWAVE TROUGHS MOVE THROUGH THE QUICK NORTHWEST
FLOW TO BRING FAVORABLE CONDITIONS FOR SOME RAIN OR THUNDERSTORMS
ACROSS PORTIONS OF THE AREA. CONFIDENCE ON TIMING OF THESE SYSTEMS
IS NOT HIGH...BUT DO BELIEVE THERE WILL BE SCATTERED SHOWERS AND
STORMS FROM TIME TO TIME THROUGH THE NEXT WEEK DESPITE WARMING
TEMPERATURES AS THE UPPER LEVEL RIDGE BUILDS INTO THE PLAINS.
SPEAKING OF TEMPERATURES...EXPECT A SLOW MODERATION OF
TEMPERATURES THROUGH THE FIRST HALF OF NEXT WEEK AS THE NORTHWEST
FLOW KEEPS COOLER AIR ACROSS THE AREA. BUT BY THURSDAY...850MB
TEMPERATURES RISE BACK INTO THE LOW 20S...SO LOOKING FOR A RETURN
TO NEAR TO ABOVE NORMAL TEMPERATURES WHICH ARE NEAR 80 DEGREES FOR
HIGHS AND 50 DEGREES FOR LOWS AT THIS TIME OF THE YEAR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1245 PM CDT FRI SEP 12 2014
CLOUDY TO MOSTLY CLOUDY SKIES THIS AFTERNOON WITH POCKETS OF MVFR
LIFTING TO WIDESPREAD VFR THRU THE EARLY AFTERNOON HOURS. HIGH
PRESSURE BUILDS IN WITH SKIES BECOMING SKC TOWARDS SUNSET AND
CONTINUING OVERNIGHT. WINDS DECOUPLE AND BECOME LIGHT AND
VARIABLE OVERNIGHT...HOWEVER LOCALLY SOUTHERLY WINDS OF 5 TO 10
KTS POSSIBLE. TOMORROW MORNING SKIES CONTINUE TO BE SKC WITH
SOUTHERLY WINDS GUSTING TO AROUND 15 KTS ONCE THE BL BEGINS TO
MIX.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY FROM 4 AM TO 10 AM CDT SATURDAY FOR NEZ028-029-
038-059-071.
&&
$$
UPDATE...MASEK
SYNOPSIS...POWER
SHORT TERM...POWER
LONG TERM...BROOKS
AVIATION...MASEK
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
307 PM EDT FRI SEP 12 2014
.SYNOPSIS...
A COLD FRONT WILL BRING UNSETTLED WEATHER THROUGH THE WEEKEND. THE
FRONT WILL WEAKEN ON MONDAY BUT MOISTURE WILL LINGER FOR A
SCATTERING OF SHOWERS MONDAY. ANOTHER COLD FRONT SHOULD AFFECT THE
REGION ON WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM FRIDAY...CONVECTIVE PROCESSES WELL UNDERWAY WITH SLOW
MOVING HARD-HITTING CELLS SMACKING PAVEMENT...YARDS AND FIELDS
WITH SCATTERED TORRENTIAL RAINFALL CORES. THE SEA-BREEZE FRONT
WAS NEARLY FILLED IN WITH TOWERING CUMULUS CELLS...AND ROUGHLY
ALONG A QUASI-STATIONARY FRONTAL BOUNDARY DRAPED ACROSS OUR
SE NC INTERIOR NORTHERN TIER. THE BOUNDARY EXTENDED SOUTHWEST
INTO CENTRAL SC WHERE HEAVY RAIN CORES WERE DRIFTING SLOWLY E.
BECAUSE OF THE TENUOUS UPPER SUPPORT WITH THIS SYSTEM...DIURNAL
HEATING AND COOLING DIURNAL TRENDS WILL LIKELY REMAIN SIGNIFICANT
INFLUENCES ON PCPN GENERATION AND RAIN-RATES. HIGH PWATS AND
OUTFLOWS AS WELL AS THE SEA BREEZE CONVERGENCE ITSELF WILL SUSTAIN
STORMS INTO THE EVENING HOURS. A FEW IMPULSES ALOFT TRAVERSING THE
SFC BOUNDARY WILL LIKELY KEEP A CHANCE OF SHRA/TSTMS GOING EVEN
INTO THE OVERNIGHT...BUT OVERALL RAIN-RATES AND STORM COVERAGE IS
EXPECTED TO SHOW SOME SCALING BACK AS SURFACE HEATING TAILS OFF
AND IS TAPPED INTO OVER THE NEXT 8 HOURS. TROPICAL MOISTURE AND
WEAK STEERING WINDS WILL ALLOW SOME AREAS TO EXPERIENCE LOCALIZED
FLOODING AT TIMES THROUGH EARLY SATURDAY.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...ANOTHER FAIRLY UNSETTLED AFTERNOON IN STORE FOR
THE REGION SATURDAY AS COLD FRONT ENTERS THE COASTAL PLAIN IN THE
PRESENCE OF FAIRLY DEEP TROPICAL MOISTURE. THE MOST WIDESPREAD
COVERAGE WILL BE OVER NWRN ZONES WHICH WILL BE MOST PROXIMAL TO THE
BOUNDARY...PERHAPS RADAR COVERAGE NOT UNLIKE THAT OF THIS AFTERNOON.
WITH A MORE CLOUDY START COMPARED TO TODAY AFTERNOON TEMPERATURES
WILL NOT GROW AS HOT AND TEND TO BE QUITE SEASONABLE. PRECIPITABLE
WATER REMAINS ABOVE 2 INCHES WHILE STORM MOTION REMAINS BELOW 5KT SO
CHANCE FOR HEAVY DOWNPOURS REMAINS INTACT. RAIN CHANCES WILL HAVE A
HARD TIME DIPPING MUCH LOWER THAN LOW END CHANCE RANGE SATURDAY
NIGHT AS THE FRONT MOVES ATOP OF THE FORECAST AREA...ALTHOUGH THE
LOSS OF DAYTIME HEATING SHOULD DIMINISH THEIR INTENSITY AND THE
HEAVY RAIN THREAT. WE WIND UP ON THE OTHER SIDE OF THE FRONT ON
SUNDAY AS IT REMAINS NEARLY STALLED TO OUR SOUTH AND EAST. RAIN
CHANCES WILL BE SHIFTED SOUTH AND EAST ACCORDINGLY AND THE HEAVY
RAIN THREAT WILL BE RELATIVELY MITIGATED. SUNDAY AFTERNOON MAY OFFER
UP A RANGE OF HIGH TEMPERATURES FROM NORTH TO SOUTH FROM THE UPPER
70S TO THE MID 80S.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 3 PM FRIDAY...WEAKENING FRONT STALLED IN THE AREA AT THE START
OF THE PERIOD AND DEEP TROPICAL MOISTURE ENSURE THE FIRST HALF OF
NEXT WEEK REMAIN UNSETTLED. PRECIPITABLE WATER VALUES AROUND 2
INCHES MON AND TUE IN A MODERATELY UNSTABLE AIRMASS SHOULD LEAD TO
SHOWER AND THUNDERSTORM DEVELOPMENT. PLAN TO CARRY CHC POP WITH A
DIURNAL DISTRIBUTION. THE LACK OF FORCING ALOFT SHOULD LEAD TO A
DECREASE IN COVERAGE/ACTIVITY OVERNIGHT BUT DO NOT THINK STORMS WILL
COMPLETELY DISSIPATE. STORM MOTIONS WILL REMAIN 10 KT OR LESS WHICH
WILL MAINTAIN FLOODING POTENTIAL.
A STRONGER COLD FRONT WILL DROP IN FROM THE NORTHWEST MID WEEK. THIS
FRONT HAS A MORE DEFINED TROUGH BEHIND IT WHICH WILL PUSH THE
BOUNDARY SOUTH OF THE AREA BY THE END OF THE WEEK. HOWEVER THERE IS
STILL SOME UNCERTAINTY AS TO HOW FAR SOUTH THIS FRONT MOVES BEFORE
STALLING. ECMWF HAS THE FRONT FARTHER SOUTH...SO DOES WPC...WHILE
THE GFS KEEPS THE FRONT CLOSER TO THE CAROLINAS. BOTH MEDIUM RANGE
SOLUTIONS DEVELOP A WEAK LOW ON THE FRONT AND LIFT IT NORTH...THOUGH
TIMING IS DIFFERENT. ECMWF SOLUTION WOULD PRODUCE SLIGHT CHC TO LOW
CHC OF PRECIP THROUGH THU...MAINLY ALONG THE COAST...WITH DRYING
FRI. GFS IS WETTER WITH HIGH CHC TO LIKELY POP THROUGH THE END OF
THE PERIOD FOR MUCH OF THE FORECAST AREA. PREVIOUS FORECASTS HAVE
BEEN IN LINE WITH THE DRIER ECMWF/WPC SOLUTION AND AT THIS POINT CAN
SEE NO REASON TO MAKE A CHANGE. CONFIDENCE REMAINS LOW SO
SIGNIFICANT CHANGES IN LATER FORECASTS IS STILL A POSSIBILITY.
TEMPERATURE RANGES EARLY IN THE PERIOD WILL BE ON THE NARROW END
WITH CLOUD COVER AND PRECIP KEEPING HIGHS NEAR TO SLIGHTLY BELOW
CLIMO BUT HELPING HOLD LOWS SEVERAL DEGREES ABOVE CLIMO. PASSAGE OF
FRONT MID WEEK WILL BRING BELOW CLIMO TEMPS FOR THE END OF THE WEEK.
&&
.AVIATION /18Z FRIDAY THROUGH TUESDAY/...
AS OF 18Z...THE HRRR MODEL HAS PRETTY ROBUST SEA BREEZE CONVECTION
THIS AFTERNOON. DO BELIEVE THE RESULTANT WILL BE THE FOCUS...BUT
ONLY SCATTERED CONVECTION EXPECTED. BRIEF PERIODS OF LOW
VISIBILITIES EXPECTED IN THE HEAVIER SHOWERS AND ISOLATED THUNDER.
STEERING FLOW WILL LIKELY KEEP MOST OF THE ACTIVITY NEAR THE
COAST...REACHING INLAND AFTER 20Z. TONIGHT COLD FRONT WILL BE
THROUGH MOST OF THE CWA...WITH AN IFR CEILING EXPECTED AFTER
MIDNIGHT...POSSIBLY THROUGH MID MORNING. FRONTAL BOUNDARY WILL STILL
BE OVER THE AREA...WITH CONVECTION EXPECTED TO REFIRE BY LATE
MORNING. LITTLE TO NO PRESSURE GRADIENT...SO WINDS WILL BE VARIABLE.
EXTENDED OUTLOOK...A GOOD CHANCE FOR SHOWERS/TSTMS AND TEMPO MVFR
THROUGH THE WEDNESDAY WITH A STALLED COLD FRONT.
&&
.MARINE...
NEAR TERM/THROUGH TONIGHT/...
AS OF 3 PM FRIDAY...OUTSIDE OF TSTMS NO REAL PROBLEMS EXPECTED ON
THE WATERS WITH LIGHT WINDS OVERALL AND SEAS 2 FEET OR LESS...AS A
WEAK FRONTAL BOUNDARY REMAINS IN VICINITY OF THE AREA. MOST STORMS
SHOULD STAY OVER LAND BUT TONIGHT CELLS MAY BEGIN TO FAVOR THE
0-20 NM WATERS. SEAS AROUND 2 FEET IN A MIX OF SE WAVES 1-1.5 FT
EVERY 8-9 SECONDS AND S WAVES 0.5-1 FT EVERY 3-4 SECONDS. WITHIN
TSTMS WINDS AND SEAS WILL BE LOCALLY AND SIGNIFICANTLY HIGHER.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...PREFRONTAL SOUTHWESTERLY FLOW ON SATURDAY SHOULD
REMAIN AT 10 KT PREVENTING SEAS FROM ATTAINING HEIGHTS MORE THAN 2
FT. LATE SATURDAY NIGHT AS THE FRONT DRAWS NEAR THE COAST THERE MAY
BE A GENTLE BACKING OF THE FLOW FOLLOWED BY A MORE PRECIPITOUS VEER
ON SUNDAY ASSOCIATED WITH ACTUAL FROPA. THE FRONT WILL NOT MOVE VERY
FAR TO OUR SOUTH BEFORE STALLING WHICH PRECLUDES MUCH OF A SURGE OF
HIGH PRESSURE AND THUS ANY HIGHER WINDS. THUS THE VEER TO ENE FLOW
APPEARS TO BE THE MAIN EFFECT OF THE FROPA AS WIND SPEEDS AND WAVE
HEIGHTS REMAIN UNCHANGED...ALTHOUGH WAVE PERIODS MAY SHORTEN UP A
BIT.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 3 PM FRIDAY...DIMINISHING NORTHERLY SURGE AT THE START OF THE
PERIOD WILL LEAVE LIGHT AND VARIABLE WINDS OVER THE WATERS FOR MUCH
OF MON AND TUE GIVEN PROXIMITY TO THE STALLED FRONT. ANOTHER COLD
FRONT WILL DROP IN FROM THE NORTHWEST DURING THE SECOND HALF OF THE
PERIOD. THIS FRONT IS MORE DEFINED AND SHOULD BE ACCOMPANIED BY A
STRONGER NORTHERLY SURGE LATER WED INTO WED NIGHT. WINDS WILL
APPROACH A SOLID 15 KT WED NIGHT WITH GUSTS AROUND 20 KT POSSIBLE.
SEAS 2 TO 3 FT FOR MUCH OF THE PERIOD WILL BUILD AS HIGH AS 5 FT AS
THE PERIOD ENDS DUE TO THE PROLONGED AND STEADILY INCREASING NATURE
OF THE NORTHERLY SURGE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...MJC
SHORT TERM...MBB
LONG TERM...III
AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
122 PM EDT FRI SEP 12 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH SLOWLY FROM THE NORTHWEST TODAY BEFORE
BECOMING STATIONARY ALONG THE COAST. UNSETTLED WEATHER AS A RESULT
WILL LIKELY PREVAIL AT TIMES THROUGH EARLY NEXT WEEK WITH SCATTERED
LOCALLY HEAVY RAIN SHOWERS AND THUNDERSTORMS. CANADIAN HIGH PRESSURE
IS EXPECTED TO EDGE INTO THE CAROLINAS NEXT WEEK...BRINGING COOLER
AIR INTO THE REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 955 AM FRIDAY...LONGER LOOP WATER VAPOR ANIMATIONS SHOW THE
APPROACHING FRONTAL SYSTEM HAS BEEN ENCOMPASSED BY DRY MID-LEVEL
AIR THROUGH MUCH OF ITS EVOLUTION AND PROGRESSION EASTWARD. EVEN
WITH PRECIPITABLE WATERS OF AROUND 2 INCHES CURRENTLY...12Z RAOBS
SHOW DRY SLABS CAPPING THE COLUMN INDUCING A DEGREE OF INHIBITION
THIS MORNING. AS A RESULT FULLY EXPECT DIURNAL HEATING TO PLAY A
SIGNIFICANT ROLE IN PCPN GENERATION LATER TODAY...PARTICULARLY AS
IMPLIED BY VSBL DATA...THAT SURFACE HEATING/INCREASING STABILITY
IS PRESENTLY UNDERWAY.
SURFACE ANALYSIS SHOWS A DEWPOINT BOUNDARY IS DIPPING SOUTHWARD
ACROSS VIRGINIA AT 14Z/10AM...WITH BALMY SW FLOW AND ELEVATED TD
VALUES SOUTH OF THIS BOUNDARY. PRESSURE ANALYSIS SUGGESTS THE COLD
FRONT IS POSITIONED FROM OBX NC TO PGV TO SOP TO CAE SC TO MCN GA.
INSOLATION AND DEEP MOISTURE AS THE CAP IS OVERCOME SHOULD HAVE
NO ISSUES IN CREATING CUMULO-NIMBUS CELLS IN THE AFTERNOON WHILE
STEERING WINDS APPEAR POISED TO DIRECT ACTIVITY SLUGGISHLY TO THE
EAST. THUS WITH A VAPOR LOADED COLUMN AND SLOW STORM MOTION A LOW-
END THREAT OF LOCALIZED FLOODING OR PONDING ON CONCRETE IS IN THE
CARDS THIS AFTERNOON AND TONIGHT. THE SEA BREEZE CONVERGENCE WILL
SERVE AS ADDED LOW-LEVEL FOCUS.
WILL NEED TO TAKE A CLOSER LOOK A MAX T TODAY. TRENDS ARE HEATING
UP QUICK BUT AT SOME POINT SUSPECT THE TEMP CURVES SHOULD LEVEL
OFF OR FLATTEN AS CU DEVELOPMENT AND CLOUD-TEAMING UNFOLDS. ANY
CHANGES WITH THE MORNING UPDATE WOULD BE TO RAISE CURRENT MAX T
NUMBERS POTENTIALLY A DEGREE OR TWO.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
AS OF 330 AM FRIDAY...COLD FRONT WILL BE HUNG UP OVER THE
COASTAL CAROLINAS THROUGH THE WEEKEND KEEPING UNSETTLED WEATHER
AND REMAINING THE FOCAL POINT FOR CONVECTIVE DEVELOPMENT. A
SHORTWAVE RIDING AROUND VERY BROAD TROUGH EXTENDING DOWN FROM THE
GREAT LAKES WILL TRY AND NUDGE IT SOUTHWARD LATE SATURDAY INTO
SUNDAY BUT IT COMES UP AGAINST RIDGE TO THE SOUTH AND ENDS UP
REMAINING IN THE VICINITY STRETCHING OUT FROM W-SW TO E-NE NEAR
THE BORDER BETWEEN NORTH AND SOUTH CAROLINA. MAY GET SOME BREAKS
IN PCP THROUGH THE WEEKEND BUT IT LOOKS LIKE COLUMN WILL REMAIN
NEARLY SATURATED MOST OF THE TIME AND THEREFORE COUNTING ON PLENTY
OF CLOUD COVER AND PCP. MAY SEE WINDS FLUCTUATE AS COLD FRONT
MEANDERS ACROSS THE REGION BUT OVERALL GRADIENT REMAINS RELAXED
WITH LIGHT WINDS. LOOKS LIKE BEST CHC OF HEAVIER PCP WILL BE
FOCUSED OVER NC EARLIER IN THE WEEKEND AND THEN SHIFT OVER SC INTO
EARLY NEXT WEEK. PCP WATER VALUES REMAIN UP AROUND 2.25 INCHES
WITH ONLY A SLIGHT DROP OVER NC BY END OF WEEKEND. BEST SHORTWAVE
ENERGY AND JET DYNAMICS REMAIN NORTH OF AREA SAT AFTN AND
THEREFORE EXPECT STRONGEST CONVECTION TO REMAIN WELL NORTH OF
AREA...BUT FRONT WILL REMAIN FOCAL POINT FOR CONVECTION THROUGH
THE WEEKEND. QPF AMOUNTS SHOULD BE GREATER OVER NC ON
SAT...SHIFTING SOUTH AND CLOSER TO THE COAST BY SUNDAY.
MAXIMUM TEMPERATURES ARE EXPECTED TO REACH INTO THE LOWER TO
MIDDLE 80S EACH DAY WITH MINIMUM TEMPERATURES FALLING TO AROUND
70 DEGREES. BY SUNDAY COOLER AIR WILL BLEED IN FROM THE NORTH AS
BOUNDARY GETS PUSHED SOUTH. THEREFORE EXPECT TEMPS TO RUN BELOW 80
OVER PEE DEE REGION WITH PLENTY OF CLOUDS BOTH DAYS.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 330 AM FRIDAY...LINGERING COLD FRONT NEAR OR JUST SOUTH OF
LOCAL FORECAST AREA THE COASTAL CAROLINAS WILL WEAKEN MON INTO
TUES. SHOULD SEE COOL NORTHEASTERLY FLOW OVER MUCH OF THE AREA
EARLY MONDAY WITH W-SW FLOW RIDING OVER IT. THIS MAY CREATE A NICE
BLANKET OF STRATUS...BUT ALSO MAY HAVE ENOUGH CONVERGENCE ALONG
FRONT TO PRODUCE SOME CONVECTION. WILL DEPEND ON EXACT LOCATION OF
FRONT AND AT THIS POINT SOME UNCERTAINTY STILL EXISTS. MOISTURE
PROFILES DO SHOW OVERALL MOISTURE THROUGH THE COLUMN DIMINISHING
SLIGHTLY BUT STILL SEEING PCP WATER VALUES NOT DROPPING MUCH BELOW
2 INCHES THROUGH WED. OVERALL EXPECT PLENTY OF CLOUDS AND PROBABLY
LOWER END QPF AMOUNTS OVERALL BUT CAN NOT RULE OUT CONVECTIVE
DEVELOPMENT ALONG LINGERING FRONT. MAY EVEN SEE TEMPS INTO THE MID
80S MON AND TUES AS MID TO UPPER RIDGE RIDGE BUILDS SLIGHTLY
ACROSS THE AREA...BUT THESE TEMPS MAY END UP TOO HIGH IN THICKER
CLOUD COVER AND PCP.
BY WED INTO THURS THE BROAD UPPER TROUGH OVER THE GREAT LAKES INTO
CANADA WILL BEGIN TO SHIFT EAST DIGGING DOWN INTO THE SOUTHEAST.
THIS MAY PUSH A SECONDARY FRONT SOUTH AND MAY GIVE ENOUGH OF A
PUSH TO FINALLY CLEAR OUT THE WEATHER BUT LATEST GFS SHOWS A WAVE
OF LOW PRESSURE DEVELOPING ALONG THE THE FRONT WHICH MAY KEEP
UNSETTLED WEATHER OVER THE AREA FOR YET ANOTHER DAY. THE ECMWF
REMAINS MORE OPTIMISTIC PUSHING THE FRONT OFF SHORE WITH COOLER
AND DRIER HIGH PRESSURE BUILDING DOWN BEHIND IT.
&&
.AVIATION /18Z FRIDAY THROUGH TUESDAY/...
AS OF 18Z...THE HRRR MODEL HAS PRETTY ROBUST SEA BREEZE CONVECTION
THIS AFTERNOON. DO BELIEVE THE RESULTANT WILL BE THE FOCUS...BUT
ONLY SCATTERED CONVECTION EXPECTED. BRIEF PERIODS OF LOW
VISIBILITIES EXPECTED IN THE HEAVIER SHOWERS AND ISOLATED THUNDER.
STEERING FLOW WILL LIKELY KEEP MOST OF THE ACTIVITY NEAR THE
COAST...REACHING INLAND AFTER 20Z. TONIGHT COLD FRONT WILL BE
THROUGH MOST OF THE CWA...WITH AN IFR CEILING EXPECTED AFTER
MIDNIGHT...POSSIBLY THROUGH MID MORNING. FRONTAL BOUNDARY WILL STILL
BE OVER THE AREA...WITH CONVECTION EXPECTED TO REFIRE BY LATE
MORNING. LITTLE TO NO PRESSURE GRADIENT...SO WINDS WILL BE VARIABLE.
EXTENDED OUTLOOK...A GOOD CHANCE FOR SHOWERS/TSTMS AND TEMPO MVFR
THROUGH THE WEDNESDAY WITH A STALLED COLD FRONT.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 955 AM FRIDAY...DOCILE WIND FORECAST THIS PERIOD DUE TO A WEAK
SFC COLD FRONT DROPPING SE-WARD. THE SFC PG AHEAD OF THIS BOUNDARY
NOT ALL THAT IMPRESSIVE AND THUS WILL KEEP WINDS LESS THAN OR
EQUAL TO 15 KT. THE WIND DIRECTION FORECAST HAS AN INCREASED BUST
POTENTIAL DUE TO EACH OF THE MODELS OWN PARTICULAR SOLUTION WITH
REGARD TO THE POSITIONING OF THE COLD FRONT DURING THE NEXT 24
HRS. AT THIS POINT...WILL KEEP THE SFC COLD FRONT INLAND THIS
PERIOD ALLOWING WIND DIRECTIONS TO KEEP A SOUTHERLY TRAJECTORY TO
THE WIND FIELD. SIGNIFICANT SEAS WILL RUN 2 TO OCCASIONALLY 3 FT.
A 1-2 FOOT EASTERLY PSEUDO GROUND SWELL AT 8 SECOND PERIODS WILL
MOSTLY DOMINATE SIG. SEAS...WITH THE OTHER PORTION COMING FROM THE
LOCALLY PRODUCED 3 TO 5 SECOND PERIOD WIND DRIVEN WAVES.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 330 AM FRIDAY...A LIGHT SOUTHERLY FLOW AHEAD OF COLD FRONT
WILL SHIFT AROUND TO NORTHEAST AS SHORTWAVE PUSHES COLD FRONT SOUTH OF
THROUGH LATE SATURDAY INTO SUNDAY. OVERALL EXPECT RATHER BENIGN
SEAS OF LESS THAN 3 FT OVER THE WEEKEND AS WINDS REMAIN 10 KTS OR
LESS AND MAY FLUCTUATE DEPENDING ON HOW FAR SOUTH THE FRONT MAKES
IT BEFORE STALLING OUT. CLOUD COVER AND PCP WILL HAMPER SURFACE
HEATING OVER THE LAND AND THEREFORE WILL KEEP SEA BREEZE WEAKER.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 330 AM FRIDAY...WINDS WILL REMAIN VERY LIGHT AND SOMEWHAT
VARIABLE AS LINGERING COLD FRONT WASHES OUT OVER THE WATERS
THROUGH EARLY NEXT WEEK. SEAS GENERALLY LESS THAN 3 FT THROUGH MONDAY
INTO EARLY TUES...BUT WNA SHOWS A LONGER PERIOD UP TO 14 SECOND EASTERLY
SWELL MOVING IN BY LATE TUES...POSSIBLY FROM TROPICAL SYSTEM
MOVING OUT OVER THE DISTANT ATLANTIC WATERS. THIS SHOULD PRODUCE A
GRADUAL RISE IN SEAS UP FROM 2 TO 3 FT TO AROUND 4 FT IN OUTER
WATERS.
&&
.TIDES/COASTAL FLOODING...
AS OF 10 AM FRIDAY...LATEST MODEL GUIDANCE ONCE AGAIN PUSH THE
TIDE GAGE LOCATED IN THE LOWER CAPE FEAR RIVER IN THE VICINITY OF
DOWNTOWN WILMINGTON...ABOVE THE 5.5 FT MLLW THRESHOLD FOR
SHALLOW/MINOR COASTAL FLOODING. IN FACT...MODELS TAKE IT TO JUST
6.00 FT MLLW AROUND 1 PM THIS AFTERNOON. OVERALL...BETWEEN THE
HOURS OF NOON AND 3 PM TODAY...MODEL GUIDANCE SUGGESTS GREATER
THAN OR EQUAL TO 5.5 FT MLLW TO OCCUR. AS A RESULT...A CFW HAS
BEEN ISSUED FOR BOTH INLAND AND COASTAL NEW HANOVER. COASTAL NEW
HANOVER IS INCLUDED...PARTICULAR FOR ROADWAYS SOUTH OF SNOWS CUT
BRIDGE BORDERING THE LOWER CAPE FEAR RIVER. AND...ACROSS CANAL
DRIVE OF CAROLINA BEACH.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY UNTIL 3 PM EDT THIS AFTERNOON FOR
NCZ107-108.
MARINE...NONE.
&&
$$
SYNOPSIS...MJC
NEAR TERM...DCH/MJC
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...DL
TIDES/COASTAL FLOODING...DCH
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
129 PM EDT FRI SEP 12 2014
.SYNOPSIS...
A COLD FRONT EXTENDS FROM THE MID ATLANTIC COAST...WEST THROUGH
THE LOWER TENNESSEE VALLEY AND INTO EAST TEXAS. THIS FRONT WILL
DRIFT A LITTLE FARTHER SOUTH TODAY...BECOMING NEARLY STATIONARY
JUST SOUTH OF OUR REGION. A WAVE OF LOW PRESSURE WILL RIPPLE EAST
ALONG THE FRONT TONIGHT AND SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1225 PM EDT FRIDAY...
WEDGE HAS ADVANCED THROUGH THE EASTERN COUNTY WARNING AREA WITH
LOWER DEW POINTS AND MORE STABLE AIR AS SEEN ON THE MSAS LIFTED
INDEX ANALYSIS AT 16Z/NOON. MOST LIKELY LOCATION FOR SCATTERED
THUNDERSTORMS THIS AFTERNOON REMAIN IN THE NORTH CAROLINA
MOUNTAINS AND FOOTHILLS WERE THERE HAS BEEN SOME HEATING AND CAPES
WERE UP CLOSE TO 900 J/KG. LOCAL WRF AND HRRR RUNS HAVE STORMS
DEVELOPING BETWEEN 17Z/1PM AND 19Z/3PM. MODELS ALSO BRING LOW
LEVEL WINDS AROUND TO THE NORTHEAST THEN EAST BY 20Z/4PM WHICH
WILL ALSO INCREASE THE CONVERGENCE ALONG THE SOUTHERN BLUE RIDGE
DURING THIS TIME FRAME.
HAVE ADJUSTED THE MAXIMUM TEMPERATURES A COUPLE OF DEGREES DOWN IN
THE NORTHEAST UNDER THE WEDGE...AND A FEW DEGREES WARMER IN THE
SOUTHWEST WHERE THERE HAS BEEN MORE SUN.
BY TONIGHT ALL AREAS WILL BE UNDER THE GUN FOR NUMEROUS
SHOWERS...AND OR A MUCH LARGER SCALE RAIN EVENT. MODELS ARE IN
AGREEMENT THAT A WAVE OF LOW PRESSURE WILL RIPPLE EAST ALONG THE
FRONT TONIGHT...WIDESPREAD RAIN/DRIZZLE DEVELOPING OVER THE
AREA...CONTINUING SATURDAY. THERE IS A VERY DISTINCT UPPER LEVEL
TROUGH THAT WILL BE MOVING OUT OF THE CENTRAL PLAINS
TODAY...CROSSING THE OHIO VALLEY TONIGHT. STRONG DYNAMIC LIFT
ASSOCIATED WITH THIS FEATURE WILL RESULT IN A BAND OF RAIN THAT
WILL MOVE EAST ACROSS THE OHIO VALLEY...APPROACHING OUR AREA FROM
THE WEST. MORE IMPORTANTLY...BACKING FLOW AHEAD OF THIS TROF WILL
CAUSE LOW LEVEL WINDS OVER THE MID ATLANTIC REGION TO BECOME
SOUTHEASTERLY. THIS SOUTHEAST WIND WILL THEN MOVE UPSLOPE INTO THE
BLUE RIDGE...THIS INCREASING OROGRAPHIC LIFT RESULTING IN
RAIN/DRIZZLE/FOG.
GENERAL RAINFALL ACROSS THE CWA THROUGH TONIGHT IS EXPECTED TO
BE AROUND A QUARTER OF AN INCH. HOWEVER...AN ENHANCED AREA OF
RAINFALL IS LIKELY TO OCCUR OVER THE NORTH CAROLINA MOUNTAINS
WHERE UPWARDS OF AN INCH OF RAIN MAY OCCUR. A SIMILAR SITUATION
OCCURRED LAST WEEKEND WHEN THE NC HIGH COUNTRY ENDED UP WITH 1-3
INCHES OF RAIN...THE FRONT AT THAT TIME LAGGING. THE NET RESULT
WAS WARMER TEMPERATURES DURING THE DAY PRIOR TO THE RAINFALL (6
DEG ABOVE GUIDANCE) AND CAPES OF ABOUT 1000 J/KG. BUFKIT SOUNDING
AT BOONE TODAY IS SUGGESTING THE CAPE WILL REACH 750 J/KG. COMBINE
THIS WITH A PWAT THAT IS CLOSE TO 200% ABOVE NORMAL AND THE NET
EFFECT MAY BE THE SAME AS LAST SUNDAYS HIGH COUNTRY DELUGE.
CLOUDS WILL EVENTUALLY FILL BACK IN PER THE APPROACHING UPPER
LEVEL TROUGH AND BACKING LOW LEVEL FLOW. TEMPERATURES TONIGHT
SHOULD LEVEL OFF CLOSE TO THE DEWPOINT VALUES...THE RAIN COOLED
AIR RESULTING IN TMINS IN THE U50S/L60S.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 430 AM EDT FRIDAY...
BY SATURDAY MORNING...AN UPPER LEVEL TROUGH WILL PASS RAPIDLY
EASTWARD ACROSS THE GREAT LAKES...WHILE UPPER LEVEL RIDGING WILL
REMAIN STEADFAST ACROSS THE SOUTHEAST. DEEPENING SURFACE LOW
PRESSURE ASSOCIATED WITH THE UPPER TROUGH WILL BE RACING NORTHEAST
OF OUR AREA INTO QUEBEC...DRAGGING A COLD FRONT TOWARD THE
APPALACHIAN CHAIN.
WITH WINDS HAVING SHIFTED SOUTHWESTERLY AHEAD OF THE APPROACHING
COLD FRONT...ATLANTIC MOISTURE WILL POOL ACROSS OUR AREA...PUSHING
PRECIPITABLE WATER VALUES INTO THE 1.6 TO 1.9 INCH RANGE.
INSTABILITY ASSOCIATED WITH THE UPPER TROUGH...COMBINED WITH LOW
LEVEL CONVERGENCE AHEAD OF THE FRONT...WILL SUPPORT RAIN FOR MUCH OF
OUR AREA...SOME OF WHICH WILL BE LOCALLY HEAVY. BELIEVE RAINFALL
WILL BE ON AND OFF BUT NEARLY EVERYWHERE WILL OBSERVE MEASURABLE
RAINFALL AT SOME POINT DURING THE MORNING. THE COLD FRONT WILL ENTER
OUR SOUTHEAST WEST VIRGINIA COUNTIES BY LATE MORNING...WITH DRIER
COOLER CANADIAN AIR BUILDING FROM BEHIND. AS SUCH...EXPECT
DECREASING RAIN CHANCES FROM NORTHWEST TO SOUTHEAST DURING THE
AFTERNOON AS THE FRONT PASSES THROUGH. EXPECT ONLY SPOTTY SHOWERS
REMAINING ACROSS THE PIEDMONT DURING EARLY EVENING...AS WELL AS IN
THE NORTHWEST WIND UPSLOPE AREAS ACROSS THE MOUNTAINS. THE FRONT
WILL BEGIN TO STALL ACROSS THE CAROLINAS SATURDAY NIGHT AS UPPER
RIDGING ACROSS THE AREA HALTS ITS SOUTHWARD ADVANCE.
HIGH PRESSURE WILL SHIFT ACROSS THE GREAT LAKES SATURDAY NIGHT INTO
NEW ENGLAND...WHERE IT WILL THEN BUILD SOUTHWARD...HUGGING THE
EASTERN FACE OF THE APPALACHIANS. NORTHEAST WINDS FLOWING AROUND THE
HIGH WILL DRAW COOL MARITIME AIR INTO OUR AREA...FORCING IT UP THE
BLUE RIDGE. AS SUCH...EXPECT MOSTLY CLOUDY SKIES WITH AREAS OF
DRIZZLE OR LIGHT RAIN AND PATCHES OF FOG IN THE MOUNTAINS. HAVE
UNDERCUT MAV/MET GUIDANCE FOR AFTERNOON TEMPERATURES ON SUNDAY...
HOLDING MOST LOCATIONS IN THE 60S FOR HIGHS. THE EXCEPTION MAY BE IN
PORTIONS OF THE MOUNTAIN EMPIRE ON THE WESTERN SIDE OF THE HIGHER
RIDGELINES...WHICH MAY WARM INTO THE MID 70S IF THE SUN BREAKS OUT
OF THE CLOUDS.
ON MONDAY...HIGH PRESSURE WILL MOVE OFFSHORE...ALLOWING WINDS TO
GRADUALLY SHIFT MORE SOUTHERLY AS ANOTHER COLD FRONT APPROACHES FROM
THE WEST. AS SUCH...EXPECT WARMER TEMPERATURES...WITH AFTERNOON
HIGHS CLIMBING INTO THE LOW TO MID 70S. RAIN CHANCES WILL INCREASE
DURING THE EVENING...WITH THE COLD FRONT ENTERING THE AREA MONDAY
NIGHT.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 330 AM EDT FRIDAY...
UNSETTLED WEATHER CONTINUES TUESDAY AS SEVERAL UPPER LEVEL
DISTURBANCES WILL SHIFT EAST ACROSS OUR AREA. SOME DRIER AIR WILL
TRY TO PUSH ACROSS THE REGION TUESDAY NIGHT INTO WEDNESDAY.
HOWEVER...SOME ISOLATED CONVECTION MAY FORM ACROSS THE SOUTHWESTERN
HIGH TERRAIN CLOSER TO THE FRONTAL BOUNDARY WITH BETTER INSTABILITY.
WEDNESDAY NIGHT INTO FRIDAY...THE HIGH CENTER OVER NEW ENGLAND WILL
SLOWLY MOVE EAST TOWARDS THE ATLANTIC OCEAN.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 100 PM EDT FRIDAY...
GOOD CONFIDENCE IN POOR AVIATION CONDITIONS FOR TAF SITES THROUGH
THIS FORECAST PERIOD. FRONTAL BOUNDARY WHICH PUSHED THROUGH THE
REGION YESTERDAY HAS STALLED OVER THE AREA...AND ENERGY ALOFT WILL
HELP WAVES OF LOW PRESSURE TO RIPPLE ALONG THE FRONT. THIS WILL KEEP
A MOIST ELY FLOW RUNNING UP INTO THE BLUE RIDGE THROUGH SATURDAY.
MULTILAYER CLOUDS WILL MAKE IT HARD TO PIN DOWN CIGS...BUT EXPECT THE
OVERALL FLAVOR OF AVIATION CONDITIONS TO LEAN TOWARD MVFR/VFR VERY
EARLY IN THE PERIOD...THOUGH LOWER CONDITIONS WILL BRIEFLY PREVAIL
AS PATCHY AREAS OF LIGHT RAIN/DRIZZLE AFFECT INDIVIDUAL SITES...THEN
A RAPID DESCENT TO LIFR/IFR TONIGHT. BELIEVE THE BIGGEST ISSUE WILL BE
LOW CIGS THROUGH KLWB WILL LIKELY BE SOCKED IN WITH LOW VSBY AS WELL.
THERE LOOKS TO BE SOME IMPROVEMENT IN CONDITIONS LATE IN THE PERIOD AS
THE ENERGY BEGINS TO PULL AWAY AND HIGH PRESSURE OVER THE UPPER MIDWEST
NUDGES THE FRONT A BIT FURTHER SOUTH.
EXTENDED AVIATION DISCUSSION...
NOT EXPECTING MUCH IF ANY IMPROVEMENT THROUGH THE WEEKEND...EVEN
AFTER THE -RA ENDS SUNDAY...LOW LEVEL CLOUDINESS WILL REMAIN.
BEYOND SUNDAY...HIGH AMPLITUDE SYSTEMS WILL RIDE BY TO OUR NORTH IN
QUASI ZONAL FLOW. THIS WILL KEEP US ON THE EDGE OF WEATHER SYSTEMS
THROUGH THE EXTENDED PERIOD. MODELS SHOWING OVERALL MVFR TO
PERSIST INTO MONDAY BEFORE SOUTHWEST WINDS ALOFT BEGIN TO RESULT
IN IMPROVING CONDITIONS. EVEN THOUGH LOW CLOUDS ERODE ON
MONDAY...LINGERING MOISTURE EXPECTING POTENTIAL FOR MVFR AT TIMES
IN SPOTTY SHOWERS MONDAY AFTERNOON AS ANOTHER UPPER TROUGH
APPROACHES THE REGION FROM THE WEST.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PM
NEAR TERM...AMS/PM
SHORT TERM...NF
LONG TERM...NF
AVIATION...MBS/PM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1232 PM EDT FRI SEP 12 2014
.SYNOPSIS...
A COLD FRONT EXTENDS FROM THE MID ATLANTIC COAST...WEST THROUGH
THE LOWER TENNESSEE VALLEY AND INTO EAST TEXAS. THIS FRONT WILL
DRIFT A LITTLE FARTHER SOUTH TODAY...BECOMING NEARLY STATIONARY
JUST SOUTH OF OUR REGION. A WAVE OF LOW PRESSURE WILL RIPPLE EAST
ALONG THE FRONT TONIGHT AND SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1225 PM EDT FRIDAY...
WEDGE HAS ADVANCED THROUGH THE EASTERN COUNTY WARNING AREA WITH
LOWER DEW POINTS AND MORE STABLE AIR AS SEEN ON THE MSAS LIFTED
INDEX ANALYSIS AT 16Z/NOON. MOST LIKELY LOCATION FOR SCATTERED
THUNDERSTORMS THIS AFTERNOON REMAIN IN THE NORTH CAROLINA
MOUNTAINS AND FOOTHILLS WERE THERE HAS BEEN SOME HEATING AND CAPES
WERE UP CLOSE TO 900 J/KG. LOCAL WRF AND HRRR RUNS HAVE STORMS
DEVELOPING BETWEEN 17Z/1PM AND 19Z/3PM. MODELS ALSO BRING LOW
LEVEL WINDS AROUND TO THE NORTHEAST THEN EAST BY 20Z/4PM WHICH
WILL ALSO INCREASE THE CONVERGENCE ALONG THE SOUTHERN BLUE RIDGE
DURING THIS TIME FRAME.
HAVE ADJUSTED THE MAXIMUM TEMPERATURES A COUPLE OF DEGREES DOWN IN
THE NORTHEAST UNDER THE WEDGE...AND A FEW DEGREES WARMER IN THE
SOUTHWEST WHERE THERE HAS BEEN MORE SUN.
BY TONIGHT ALL AREAS WILL BE UNDER THE GUN FOR NUMEROUS
SHOWERS...AND OR A MUCH LARGER SCALE RAIN EVENT. MODELS ARE IN
AGREEMENT THAT A WAVE OF LOW PRESSURE WILL RIPPLE EAST ALONG THE
FRONT TONIGHT...WIDESPREAD RAIN/DRIZZLE DEVELOPING OVER THE
AREA...CONTINUING SATURDAY. THERE IS A VERY DISTINCT UPPER LEVEL
TROUGH THAT WILL BE MOVING OUT OF THE CENTRAL PLAINS
TODAY...CROSSING THE OHIO VALLEY TONIGHT. STRONG DYNAMIC LIFT
ASSOCIATED WITH THIS FEATURE WILL RESULT IN A BAND OF RAIN THAT
WILL MOVE EAST ACROSS THE OHIO VALLEY...APPROACHING OUR AREA FROM
THE WEST. MORE IMPORTANTLY...BACKING FLOW AHEAD OF THIS TROF WILL
CAUSE LOW LEVEL WINDS OVER THE MID ATLANTIC REGION TO BECOME
SOUTHEASTERLY. THIS SOUTHEAST WIND WILL THEN MOVE UPSLOPE INTO THE
BLUE RIDGE...THIS INCREASING OROGRAPHIC LIFT RESULTING IN
RAIN/DRIZZLE/FOG.
GENERAL RAINFALL ACROSS THE CWA THROUGH TONIGHT IS EXPECTED TO
BE AROUND A QUARTER OF AN INCH. HOWEVER...AN ENHANCED AREA OF
RAINFALL IS LIKELY TO OCCUR OVER THE NORTH CAROLINA MOUNTAINS
WHERE UPWARDS OF AN INCH OF RAIN MAY OCCUR. A SIMILAR SITUATION
OCCURRED LAST WEEKEND WHEN THE NC HIGH COUNTRY ENDED UP WITH 1-3
INCHES OF RAIN...THE FRONT AT THAT TIME LAGGING. THE NET RESULT
WAS WARMER TEMPERATURES DURING THE DAY PRIOR TO THE RAINFALL (6
DEG ABOVE GUIDANCE) AND CAPES OF ABOUT 1000 J/KG. BUFKIT SOUNDING
AT BOONE TODAY IS SUGGESTING THE CAPE WILL REACH 750 J/KG. COMBINE
THIS WITH A PWAT THAT IS CLOSE TO 200% ABOVE NORMAL AND THE NET
EFFECT MAY BE THE SAME AS LAST SUNDAYS HIGH COUNTRY DELUGE.
CLOUDS WILL EVENTUALLY FILL BACK IN PER THE APPROACHING UPPER
LEVEL TROUGH AND BACKING LOW LEVEL FLOW. TEMPERATURES TONIGHT
SHOULD LEVEL OFF CLOSE TO THE DEWPOINT VALUES...THE RAIN COOLED
AIR RESULTING IN TMINS IN THE U50S/L60S.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 430 AM EDT FRIDAY...
BY SATURDAY MORNING...AN UPPER LEVEL TROUGH WILL PASS RAPIDLY
EASTWARD ACROSS THE GREAT LAKES...WHILE UPPER LEVEL RIDGING WILL
REMAIN STEADFAST ACROSS THE SOUTHEAST. DEEPENING SURFACE LOW
PRESSURE ASSOCIATED WITH THE UPPER TROUGH WILL BE RACING NORTHEAST
OF OUR AREA INTO QUEBEC...DRAGGING A COLD FRONT TOWARD THE
APPALACHIAN CHAIN.
WITH WINDS HAVING SHIFTED SOUTHWESTERLY AHEAD OF THE APPROACHING
COLD FRONT...ATLANTIC MOISTURE WILL POOL ACROSS OUR AREA...PUSHING
PRECIPITABLE WATER VALUES INTO THE 1.6 TO 1.9 INCH RANGE.
INSTABILITY ASSOCIATED WITH THE UPPER TROUGH...COMBINED WITH LOW
LEVEL CONVERGENCE AHEAD OF THE FRONT...WILL SUPPORT RAIN FOR MUCH OF
OUR AREA...SOME OF WHICH WILL BE LOCALLY HEAVY. BELIEVE RAINFALL
WILL BE ON AND OFF BUT NEARLY EVERYWHERE WILL OBSERVE MEASURABLE
RAINFALL AT SOME POINT DURING THE MORNING. THE COLD FRONT WILL ENTER
OUR SOUTHEAST WEST VIRGINIA COUNTIES BY LATE MORNING...WITH DRIER
COOLER CANADIAN AIR BUILDING FROM BEHIND. AS SUCH...EXPECT
DECREASING RAIN CHANCES FROM NORTHWEST TO SOUTHEAST DURING THE
AFTERNOON AS THE FRONT PASSES THROUGH. EXPECT ONLY SPOTTY SHOWERS
REMAINING ACROSS THE PIEDMONT DURING EARLY EVENING...AS WELL AS IN
THE NORTHWEST WIND UPSLOPE AREAS ACROSS THE MOUNTAINS. THE FRONT
WILL BEGIN TO STALL ACROSS THE CAROLINAS SATURDAY NIGHT AS UPPER
RIDGING ACROSS THE AREA HALTS ITS SOUTHWARD ADVANCE.
HIGH PRESSURE WILL SHIFT ACROSS THE GREAT LAKES SATURDAY NIGHT INTO
NEW ENGLAND...WHERE IT WILL THEN BUILD SOUTHWARD...HUGGING THE
EASTERN FACE OF THE APPALACHIANS. NORTHEAST WINDS FLOWING AROUND THE
HIGH WILL DRAW COOL MARITIME AIR INTO OUR AREA...FORCING IT UP THE
BLUE RIDGE. AS SUCH...EXPECT MOSTLY CLOUDY SKIES WITH AREAS OF
DRIZZLE OR LIGHT RAIN AND PATCHES OF FOG IN THE MOUNTAINS. HAVE
UNDERCUT MAV/MET GUIDANCE FOR AFTERNOON TEMPERATURES ON SUNDAY...
HOLDING MOST LOCATIONS IN THE 60S FOR HIGHS. THE EXCEPTION MAY BE IN
PORTIONS OF THE MOUNTAIN EMPIRE ON THE WESTERN SIDE OF THE HIGHER
RIDGELINES...WHICH MAY WARM INTO THE MID 70S IF THE SUN BREAKS OUT
OF THE CLOUDS.
ON MONDAY...HIGH PRESSURE WILL MOVE OFFSHORE...ALLOWING WINDS TO
GRADUALLY SHIFT MORE SOUTHERLY AS ANOTHER COLD FRONT APPROACHES FROM
THE WEST. AS SUCH...EXPECT WARMER TEMPERATURES...WITH AFTERNOON
HIGHS CLIMBING INTO THE LOW TO MID 70S. RAIN CHANCES WILL INCREASE
DURING THE EVENING...WITH THE COLD FRONT ENTERING THE AREA MONDAY
NIGHT.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 330 AM EDT FRIDAY...
UNSETTLED WEATHER CONTINUES TUESDAY AS SEVERAL UPPER LEVEL
DISTURBANCES WILL SHIFT EAST ACROSS OUR AREA. SOME DRIER AIR WILL
TRY TO PUSH ACROSS THE REGION TUESDAY NIGHT INTO WEDNESDAY.
HOWEVER...SOME ISOLATED CONVECTION MAY FORM ACROSS THE SOUTHWESTERN
HIGH TERRAIN CLOSER TO THE FRONTAL BOUNDARY WITH BETTER INSTABILITY.
WEDNESDAY NIGHT INTO FRIDAY...THE HIGH CENTER OVER NEW ENGLAND WILL
SLOWLY MOVE EAST TOWARDS THE ATLANTIC OCEAN.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 800 AM EDT FRIDAY...
EXTENDED PERIOD OF MVFR OR WORSE CIGS/VSBYS EXPECTED ACROSS THE
CWA.
COLD FRONT WILL BECOME NEARLY STATIONARY AND ORIENTED EAST-WEST
JUST SOUTH OF THE REGION TODAY. THIS BOUNDARY WILL BECOME THE
FOCUS FOR OVERRUNNING MOISTURE WHICH WILL RESULT IN PERIODS OF
-RA/DZ THROUGH MUCH OF THE UPCOMING WEEKEND.
NORTH TO NORTHEAST WINDS TODAY WILL BECOME EASTERLY TONIGHT. THIS
EASTERLY UPSLOPE FLOW WILL LIKELY RESULT IN LOWERING CLOUD BASES
THAT WILL OBSCURE THE RIDGES TONIGHT...A PERSISTENT DRIZZLE
DEVELOPING OVER MOST OF THE FORECAST AREA IN ADDITION TO PERIODS
OF RAIN...CONDITIONS LOWERING TO IFR.
EXTENDED AVIATION DISCUSSION...
NOT EXPECTING MUCH IF ANY IMPROVEMENT THROUGH THE WEEKEND...EVEN
AFTER THE -RA ENDS SUNDAY...LOW LEVEL CLOUDINESS WILL REMAIN.
BEYOND SUNDAY...LOW CONFIDENCE. MODELS SHOWING OVERALL MVFR TO
PERSIST INTO MONDAY BEFORE SOUTHWEST WINDS ALOFT BEGIN TO RESULT
IN IMPROVING CONDITIONS. EVEN THOUGH LOW CLOUDS ERODE ON
MONDAY...LINGERING MOISTURE EXPECTING POTENTIAL FOR MVFR AT TIMES
IN SPOTTY SHOWERS MONDAY AFTERNOON AS ANOTHER UPPER TROUGH
APPROACHES THE REGION FROM THE WEST.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PM
NEAR TERM...AMS/PM
SHORT TERM...NF
LONG TERM...NF
AVIATION...PM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
600 PM CDT FRI SEP 12 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 257 PM CDT FRI SEP 12 2014
MAIN FORECAST CONCERNS ARE FROST AND FOG POTENTIAL TONIGHT.
LATEST WATER VAPOR SATELLITE IMAGERY SHOWING VIGOROUS SHORTWAVE
TROUGH OVER THE NORTHERN PLAINS. MOSAIC RADAR INDICATING
FRONTOGENETICAL BAND OF RAIN EXTENDING FROM NORTHEAST WISCONSIN INTO
NORTHEAST IOWA PER 12.15Z RAP 700-600MB FN VECTOR CONVERGENCE.
ALSO...MOSAIC RADAR SHOWING DIURNALLY DRIVEN SCATTERED SHOWERS OVER
CENTRAL MINNESOTA UNDERNEATH MAIN SHORTWAVE TROUGH.
TONIGHT...SHORTWAVE TROUGH AND ASSOCIATED LOW LEVEL MOISTURE/RAIN
PROGGED TO PUSH QUICKLY EAST INTO MICHIGAN THIS EVENING PER THE
LATEST 12.12Z GFS/NAM AND 12.15Z RAP RELATIVE HUMIDITY FIELDS. THIS
IS EVIDENT PER LATEST VISIBLE SATELLITE IMAGERY SHOWING DIURNAL
CUMULUS FIELD WEST OF A LINE FROM FAIRMONT MINNESOTA TO NEAR DULUTH
MINNESOTA. THIS CUMULUS FIELD WILL QUICKLY EVAPORATE DUE TO LOSS OF
DAYTIME HEATING THIS EVENING AND ALLOW SKIES TO CLEAR WEST TO EAST
ACROSS THE FORECAST AREA. SURFACE RIDGE BUILDS INTO THE FORECAST
AREA BY 06Z AND PRODUCE CALM WINDS AND DRIER AIRMASS TO ADVECT IN.
TEMPERATURES WILL BE ABLE TO FALL RAPIDLY INTO THE 30S AND THE UPPER
20S IN THE COLD SPOTS OF CENTRAL WISCONSIN. FOR THIS...A FROST
ADVISORY WILL BE IN EFFECT FOR PORTIONS OF SOUTHEAST
MINNESOTA...NORTHEAST IOWA AND CENTRAL WISCONSIN TONIGHT. IN
ADDITION...THE COMBINATION OF RAIN TODAY...CALM WINDS AND INVERSION
DEVELOPING TONIGHT PER BUFKIT SOUNDINGS...AREAS OF FOG WILL DEVELOP
IN RIVER VALLEYS AND PARTS OF CENTRAL WISCONSIN AFTER 06Z.
DRY WEATHER CONDITIONS AND UNSEASONABLY COOL TEMPERATURES WILL
PREVAIL ACROSS THE AREA SATURDAY...AS SURFACE RIDGE REMAINS IN
CONTROL.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 257 PM CDT FRI SEP 12 2014
WARMER AIR ADVECTS INTO THE FORECAST AREA SUNDAY OUT AHEAD OF NEXT
SHORTWAVE TROUGH TO AFFECT THE REGION. TEMPERATURES WILL BE A FEW
DEGREES WARMER AND SLIGHTLY BELOW NORMAL.
NEXT CONCERN IS SHORTWAVE TROUGH MOVING OVER THE GREAT LAKES REGION
EMBEDDED IN THE WEST TO NORTHWEST FLOW SUNDAY NIGHT INTO MONDAY.
BOTH THE 12.12Z GFS/NAM SHOW STRONG PV ADVECTION/QG FORCING AND
FN CONVERGENCE FOCUSED OVER THE SOUTHERN HALF OF THE FORECAST
AREA. SOME SLIGHT DIFFERENCES OCCUR WITH THE PLACEMENT AND TIMING
OF SURFACE FEATURES BETWEEN THE 12.12Z GFS/NAM/ECMWF. WITH THE
MODELS CONTINUE TO SHOW DECENT DYNAMIC FORCING/LIFT IN ASSOCIATED
WITH SHORTWAVE TROUGH...WILL MAINTAIN PRECIPITATION CHANCES SUNDAY
INTO MONDAY MAINLY FOR THE SOUTHERN HALF OF THE FORECAST AREA.
MAIN FORECAST CONCERN ARE PRECIPITATION CHANCES FRIDAY...OTHERWISE
TEMPERATURES TUESDAY THROUGH FRIDAY. THE 12.12Z GFS/GEM/ECMWF
CONTINUE TO HAVE GOOD RUN TO RUN CONSISTENCY IN DIGGING UPPER LEVEL
TROUGH OVER THE NORTHEAST UNITED STATES AND GREAT LAKES REGION AND
SURFACE RIDGE DOMINATING THE UPPER MIDWEST TUESDAY THROUGH THURSDAY.
WITH SUBSIDENCE OVER THE FORECAST AREA...DUE TO SURFACE RIDGE...DRY
WEATHER CONDITIONS CAN BE EXPECTED ACROSS THE FORECAST AREA DURING
THIS TIME FRAME. TEMPERATURES SHOULD BE NEAR OR SLIGHTLY BELOW
NORMAL TUESDAY THROUGH THURSDAY...AS THE 12.00Z GFS/GEM/ECMWF
INDICATE 850MB TEMPERATURES RANGING FROM PLUS 5 TO PLUS 10 DEGREES
CELSIUS AND 12.12Z GEFS SHOW STANDARD ANOMALIES OF MINUS 0.5 TO
MINUS 1 DEGREE CELSIUS. SIGNIFICANT DIFFERENCES SHOW UP BETWEEN THE
12.12Z GFS/ECMWF FRIDAY...AS THE 12.12Z GFS MORE AMPLIFIED WITH
UPPER LEVEL RIDGE OVER THE UPPER MIDWEST THAN THE ECMWF AND THE
12.12Z ECMWF IS SLOWER IN PROGRESSING THE UPPER LEVEL RIDGE INTO THE
UPPER MIDWEST AND GREAT LAKES REGION. THIS HAS IMPACTS ON HOW FAST
WARMER AIR ADVECTS INTO THE REGION AND TIMING OF SURFACE WARM FRONT
INTO THE FORECAST AREA. THIS SURFACE WARM FRONT WILL BE THE FOCUS
OF PRECIPITATION CHANCES FRIDAY...WITH BOTH THE 12.12Z GFS/ECMWF
INDICATE DECENT 850MB MOISTURE TRANSPORT AND CONVERGENCE IN
ASSOCIATION WITH IMPULSE OVER THE NORTHERN PLAINS AND NORTHERN
ROCKIES. CONFIDENCE IN FORECAST ON FRIDAY IS LOW DUE TO TIMING AND
STRENGTH OF UPPER LEVEL RIDGE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 600 PM CDT FRI SEP 12 2014
LOTS OF DIURNAL ELEMENTS TO THE CLOUDS WEST OF THE MISSISSIPPI RIVER
EARLY THIS EVENING...AND EXPECT THESE TO QUICKLY DISSIPATE WITH
SUNDOWN. IN THE EAST...THE CLOUD MASS IS ASSOCIATED WITH A DEPARTING
UPPER LEVEL SHORTWAVE...AND THESE WILL TAKE A BIT LONGER TO CLEAR.
KRST SHOULD SCATTER OUT EARLY THIS EVENING...WHILE IT MIGHT HOLD OFF
UNTIL AFTER 03Z FOR THE CLEARING LINE TO REACH KLSE.
WITH CLOUDS HOLDING T/TD SPREADS CLOSE THROUGH THE DAY...AND
CLEARING SKIES JUST IN TIME FOR NIGHTTIME...ITS A FAVORABLE SETUP
FOR DIURNAL COOLING INDUCED RIVER VALLEY FOG. NOT AS MUCH T/TD
SPREAD TO MAKEUP. SFC WINDS ARE ALSO EXPECTED TO BE LIGHT THROUGH
THE NIGHT. HOWEVER...A SIGNIFICANT DRAWBACK WILL BE THE DEPTH OF THE
LIGHT WIND LAYER. RAP/NAM BUFKIT SOUNDINGS SUGGEST AT 10+ KTS OF
WIND BY 300 FT FOR MOST OF THE NIGHT. GENERALLY...THIS IT NOT
FAVORABLE FOR DENSE FOG. CERTAINLY...SOME VSBY RESTRICTIONS ARE
POSSIBLE...AND COULD SEE THICKER FOG/STRATUS BANK SITTING ON THE
MISSISSIPPI RIVER...BUT UNSURE IF IT WILL SPREAD ACROSS KLSE.
SOMETHING TO WATCH CLOSELY TONIGHT.
HIGH PRESSURE BUILDS IN SATURDAY...AND WILL RESULT IN VFR CONDITIONS
OUTSIDE OF THE EARLY MORNING FOG POTENTIAL. WINDS WILL GRADUALLY
SWING FROM WEST TO SOUTHWEST. LATER SAT NIGHT...SOME CIGS NEAR 4KFT
COULD RETURN AS LOW LEVEL WARM AIR ADVECTION AND WEAK MOISTURE
TRANSPORT LEAD A SHORTWAVE MOVING EAST ACROSS THE NORTHERN PLAINS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FROST ADVISORY FROM 3 AM TO 8 AM CDT SATURDAY FOR WIZ017-029-033-
034-042>044.
MN...FROST ADVISORY FROM 3 AM TO 8 AM CDT SATURDAY FOR MNZ086-087-094-
095.
IA...FROST ADVISORY FROM 3 AM TO 8 AM CDT SATURDAY FOR IAZ008>010-018-
019-029.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
257 PM CDT FRI SEP 12 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 257 PM CDT FRI SEP 12 2014
MAIN FORECAST CONCERNS ARE FROST AND FOG POTENTIAL TONIGHT.
LATEST WATER VAPOR SATELLITE IMAGERY SHOWING VIGOROUS SHORTWAVE
TROUGH OVER THE NORTHERN PLAINS. MOSAIC RADAR INDICATING
FRONTOGENETICAL BAND OF RAIN EXTENDING FROM NORTHEAST WISCONSIN INTO
NORTHEAST IOWA PER 12.15Z RAP 700-600MB FN VECTOR CONVERGENCE.
ALSO...MOSAIC RADAR SHOWING DIURNALLY DRIVEN SCATTERED SHOWERS OVER
CENTRAL MINNESOTA UNDERNEATH MAIN SHORTWAVE TROUGH.
TONIGHT...SHORTWAVE TROUGH AND ASSOCIATED LOW LEVEL MOISTURE/RAIN
PROGGED TO PUSH QUICKLY EAST INTO MICHIGAN THIS EVENING PER THE
LATEST 12.12Z GFS/NAM AND 12.15Z RAP RELATIVE HUMIDITY FIELDS. THIS
IS EVIDENT PER LATEST VISIBLE SATELLITE IMAGERY SHOWING DIURNAL
CUMULUS FIELD WEST OF A LINE FROM FAIRMONT MINNESOTA TO NEAR DULUTH
MINNESOTA. THIS CUMULUS FIELD WILL QUICKLY EVAPORATE DUE TO LOSS OF
DAYTIME HEATING THIS EVENING AND ALLOW SKIES TO CLEAR WEST TO EAST
ACROSS THE FORECAST AREA. SURFACE RIDGE BUILDS INTO THE FORECAST
AREA BY 06Z AND PRODUCE CALM WINDS AND DRIER AIRMASS TO ADVECT IN.
TEMPERATURES WILL BE ABLE TO FALL RAPIDLY INTO THE 30S AND THE UPPER
20S IN THE COLD SPOTS OF CENTRAL WISCONSIN. FOR THIS...A FROST
ADVISORY WILL BE IN EFFECT FOR PORTIONS OF SOUTHEAST
MINNESOTA...NORTHEAST IOWA AND CENTRAL WISCONSIN TONIGHT. IN
ADDITION...THE COMBINATION OF RAIN TODAY...CALM WINDS AND INVERSION
DEVELOPING TONIGHT PER BUFKIT SOUNDINGS...AREAS OF FOG WILL DEVELOP
IN RIVER VALLEYS AND PARTS OF CENTRAL WISCONSIN AFTER 06Z.
DRY WEATHER CONDITIONS AND UNSEASONABLY COOL TEMPERATURES WILL
PREVAIL ACROSS THE AREA SATURDAY...AS SURFACE RIDGE REMAINS IN
CONTROL.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 257 PM CDT FRI SEP 12 2014
WARMER AIR ADVECTS INTO THE FORECAST AREA SUNDAY OUT AHEAD OF NEXT
SHORTWAVE TROUGH TO AFFECT THE REGION. TEMPERATURES WILL BE A FEW
DEGREES WARMER AND SLIGHTLY BELOW NORMAL.
NEXT CONCERN IS SHORTWAVE TROUGH MOVING OVER THE GREAT LAKES REGION
EMBEDDED IN THE WEST TO NORTHWEST FLOW SUNDAY NIGHT INTO MONDAY.
BOTH THE 12.12Z GFS/NAM SHOW STRONG PV ADVECTION/QG FORCING AND
FN CONVERGENCE FOCUSED OVER THE SOUTHERN HALF OF THE FORECAST
AREA. SOME SLIGHT DIFFERENCES OCCUR WITH THE PLACEMENT AND TIMING
OF SURFACE FEATURES BETWEEN THE 12.12Z GFS/NAM/ECMWF. WITH THE
MODELS CONTINUE TO SHOW DECENT DYNAMIC FORCING/LIFT IN ASSOCIATED
WITH SHORTWAVE TROUGH...WILL MAINTAIN PRECIPITATION CHANCES SUNDAY
INTO MONDAY MAINLY FOR THE SOUTHERN HALF OF THE FORECAST AREA.
MAIN FORECAST CONCERN ARE PRECIPITATION CHANCES FRIDAY...OTHERWISE
TEMPERATURES TUESDAY THROUGH FRIDAY. THE 12.12Z GFS/GEM/ECMWF
CONTINUE TO HAVE GOOD RUN TO RUN CONSISTENCY IN DIGGING UPPER LEVEL
TROUGH OVER THE NORTHEAST UNITED STATES AND GREAT LAKES REGION AND
SURFACE RIDGE DOMINATING THE UPPER MIDWEST TUESDAY THROUGH THURSDAY.
WITH SUBSIDENCE OVER THE FORECAST AREA...DUE TO SURFACE RIDGE...DRY
WEATHER CONDITIONS CAN BE EXPECTED ACROSS THE FORECAST AREA DURING
THIS TIME FRAME. TEMPERATURES SHOULD BE NEAR OR SLIGHTLY BELOW
NORMAL TUESDAY THROUGH THURSDAY...AS THE 12.00Z GFS/GEM/ECMWF
INDICATE 850MB TEMPERATURES RANGING FROM PLUS 5 TO PLUS 10 DEGREES
CELSIUS AND 12.12Z GEFS SHOW STANDARD ANOMALIES OF MINUS 0.5 TO
MINUS 1 DEGREE CELSIUS. SIGNIFICANT DIFFERENCES SHOW UP BETWEEN THE
12.12Z GFS/ECMWF FRIDAY...AS THE 12.12Z GFS MORE AMPLIFIED WITH
UPPER LEVEL RIDGE OVER THE UPPER MIDWEST THAN THE ECMWF AND THE
12.12Z ECMWF IS SLOWER IN PROGRESSING THE UPPER LEVEL RIDGE INTO THE
UPPER MIDWEST AND GREAT LAKES REGION. THIS HAS IMPACTS ON HOW FAST
WARMER AIR ADVECTS INTO THE REGION AND TIMING OF SURFACE WARM FRONT
INTO THE FORECAST AREA. THIS SURFACE WARM FRONT WILL BE THE FOCUS
OF PRECIPITATION CHANCES FRIDAY...WITH BOTH THE 12.12Z GFS/ECMWF
INDICATE DECENT 850MB MOISTURE TRANSPORT AND CONVERGENCE IN
ASSOCIATION WITH IMPULSE OVER THE NORTHERN PLAINS AND NORTHERN
ROCKIES. CONFIDENCE IN FORECAST ON FRIDAY IS LOW DUE TO TIMING AND
STRENGTH OF UPPER LEVEL RIDGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1237 PM CDT FRI SEP 12 2014
MID LEVEL FRONTOGENETIC BAND PRODUCING RAIN MUCH OF TODAY CONTINUES
TO PRODUCE MVFR TO VFR CEILINGS. BULK OF LOWER CEILINGS ARE SOUTH
AND EAST OF TAF SITES...WITH CONDITIONS EXPECTED TO IMPROVE LATE IN
THE DAY AS THESE BANDS MOVE OFF WITH SHORT WAVE FORCING.
RAPID CLEARING EXPECTED GOING INTO THIS EVENING AS SURFACE RIDGE
BUILDS IN. WITH CLEARING SKIES...MOIST LOW LEVELS AND LIGHT WINDS...
SOME VALLEY FOG EXPECTED...ESPECIALLY SOUTH AND EAST OF KLSE. EXTENT
OF THIS UNCLEAR WITH 10-15 KTS ON HIGHER SIDE OF BOUNDARY LAYER.
VFR CONDITIONS WILL PREVAIL SATURDAY ONCE VALLEY FOG BURNS OFF AS
SURFACE RIDGE PASSES THROUGH.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FROST ADVISORY FROM 3 AM TO 8 AM CDT SATURDAY FOR WIZ017-029-033-
034-042>044.
MN...FROST ADVISORY FROM 3 AM TO 8 AM CDT SATURDAY FOR MNZ086-087-094-
095.
IA...FROST ADVISORY FROM 3 AM TO 8 AM CDT SATURDAY FOR IAZ008>010-018-
019-029.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...SHEA