Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 10/14/12
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1037 AM PDT FRI OCT 12 2012
.DISCUSSION...AS OF 9:00 AM PDT FRIDAY...FEW LIGHT SHOWERS THIS
MORNING HAVE BASICALLY COME TO AN END. RAINFALL AMOUNTS HAVE BEEN
VERY LIGHT WITH SPOTS THAT PICKED UP ANY RAIN REPORTING LESS THAN
A TENTH OF AN INCH. PLENTY OF CLOUDS ACROSS OUR AREA ALTHOUGH
UNLIKE YESTERDAY CIG HEIGHTS ARE HIGHER AND MORE BREAKS NOTED...SO
HOPEFULLY WE WILL SEE MORE SUNSHINE BY THE AFTERNOON.
SYNOPTICALLY...THE MAIN STORY WILL BE A RIDGE OF HIGH PRESSURE
THAT WILL BUILD ACROSS CALIFORNIA STARTING THIS WEEKEND AND GOING
INTO NEXT WEEK AS A REX BLOCK. THIS WILL HELP TO BRING SEVERAL DAYS OF
GENERALLY SUNNY CONDITIONS WITH HIGHS GOING BACK TO ABOVE NORMAL
LEVELS. ONLY REAL FORECAST CONCERNS IS HOW MUCH OVERNIGHT
CLOUDS/PATCHY FOG WE WILL SEE PLUS HOW WARM IT WILL BECOME. AT
LEAST ONE DAY OF WIDESPREAD 80S AND 90S LOOK LIKELY FOR INTERIOR
SPOTS DURING THE SECOND HALF OF NEXT WEEK.
.PREVIOUS DISCUSSION...LIGHT RAIN SHOWERS CONTINUE MAINLY FROM
THE SAN FRANCISCO BAY SOUTHWARD THIS MORNING. IN THE LAST 3
HOURS...MUSTANG RIDGE IN MONTEREY COUNTY RECEIVED 0.08" WHILE THE
OAKLAND SOUTH RAWS RECEIVED 0.02" IN THAT SAME TIME FRAME. THE NAM
AND HRRR SEEM TO HAVE THE BEST HANDLE OF THE CURRENT SYNOPTIC
PATTERN...AND BOTH KEEP SCATTERED SHOWERS IN THE REGION THROUGH AT
LEAST 15Z. POPS WERE SIGNIFICANTLY INCREASED BETWEEN 12Z AND 18Z
TO ACCOUNT FOR THESE SHOWERS.
SKIES WERE CLOUDY OVERNIGHT...AS ABUNDANT MID AND LOW LEVEL
MOISTURE PREVAILED OVER THE REGION. TEMPERATURES SO FAR FELL INTO
THE 50S...SIMILAR TO THOSE OBSERVED LAST NIGHT. LOW CLOUDS WILL BE
LATE TO DISSIPATE AGAIN TODAY...AND A FEW PLACES MIGHT ONLY SEE
GLIMPSES OF BLUE SKY.
OTHERWISE...THE UPPER LEVEL LOW OVER SOUTHERN CALIFORNIA IS
FORECAST TO MOVE SLOWLY EAST NORTHEAST TOWARD SOUTHERN NV AND
NORTHERN AZ BY THIS AFTERNOON. THIS WILL RESULT IN DRY...BUT COOL
CONDITIONS OVER THE REGION. WHILE THE LOW MOVES EAST...AN UPPER
LEVEL SHORT WAVE WILL SKIRT NORTHERN CALIFORNIA...BRINGING A
SLIGHT CHANCE OF SHOWERS TO FAR NORTHERN SONOMA COUNTY.
HOWEVER...THE SHORT TERM MODELS KEEP BACKING OFF WITH REGARDS TO
PRECIPITATION WITH THIS DISTURBANCE...SO CONFIDENCE IS LOW THAT WE
WILL SEE ANY RAIN IN THIS REGION.
WEAK UPPER LEVEL RIDGING WILL BEGIN TO BUILD OVER THE REGION
DURING THE SECOND HALF OF THE WEEKEND. THIS WILL RESULT IN A
SIGNIFICANT WARMING TREND THROUGH THE AREA...WITH TEMPERATURES
NEARING NEAR NORMAL READINGS FOR THE MIDDLE OF OCTOBER.
EVEN MORE SIGNIFICANT WARMING IS FORECAST FOR THE MIDDLE OF NEXT
WEEK...WITH A 588 DM RIDGE NEARING CENTRAL CALIFORNIA. 850 MB
TEMPERATURES ARE FORECAST TO RISE OVER 11 DEGREES C BETWEEN THIS
AFTERNOON AND WEDNESDAY AFTERNOON. THIS WILL RESULT IN INLAND
TEMPERATURES REACHING THE 80S TO LOW 90S...WHILE THE COASTAL
LOCATIONS REACH THE UPPER 60S TO 70S.
THE CLIMATE PREDICTION CENTERS 6 TO 10 DAY OUTLOOK CALLS FOR
TEMPERATURES WELL ABOVE NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION...AS OF 10:30 AM FRIDAY...DEFINITELY A LOW CONFIDENCE
FORECAST KINDA A DAY. BAY AREA OBS AND VISIBLE SATELLITE BOTH
INDICATE A MIX OF LOW STRATUS AND MID LEVEL CONVECTIVE CLOUDS.
THAT BEING SAID...GIVEN THE AMOUNT OF LINGERING MOISTURE AND
NEARBY SHOWERS(E OF CWA) HAVE KEEP MANY TERMINALS HIGH END MVFR TO
LOW END VFR THROUGH THE DAY. WOULD NOT BE SURPRISED IS SOME
TERMINALS FLIP FLOP FROM VFR TO MVFR AND VICE VS AROUND THE 3K FOOT
LEVEL. ONE INTERESTING THING TO MONITOR IS THE DRY SLOT SEEN ON
VIS OVER THE OCEAN. IF THIS AREA EXPANDS AND MOVES E TAFS WILL
NEED AMENDING. FOR TONIGHT...WILL BRING CIGS BACK IN THE 1-2K FOOT LEVEL.
.VICINITY OF KSFO...WILL KEEP MVFR CIGS THROUGH MUCH OF THE
AFTERNOON. WILL ALLOW FOR OCCASIONAL VFR CIGS COVERED BY TEMPO GROUPS.
EARLY RETURN POSSIBLE.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO WITH A MIX OF MVFR TO VFR
THROUGH THE DAY.
MONTEREY BAY AREA TERMINALS...MVFR CIGS THROUGH MUCH OF THE DAY.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
&&
$$
PUBLIC FORECAST: BELL/RILEY
AVIATION/MARINE: MM
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
905 AM PDT FRI OCT 12 2012
.DISCUSSION...AS OF 9:00 AM PDT FRIDAY...FEW LIGHT SHOWERS THIS
MORNING HAVE BASICALLY COME TO AN END. RAINFALL AMOUNTS HAVE BEEN
VERY LIGHT WITH SPOTS THAT PICKED UP ANY RAIN REPORTING LESS THAN
A TENTH OF AN INCH. PLENTY OF CLOUDS ACROSS OUR AREA ALTHOUGH
UNLIKE YESTERDAY CIG HEIGHTS ARE HIGHER AND MORE BREAKS NOTED...SO
HOPEFULLY WE WILL SEE MORE SUNSHINE BY THE AFTERNOON.
SYNOPTICALLY...THE MAIN STORY WILL BE A RIDGE OF HIGH PRESSURE
THAT WILL BUILD ACROSS CALIFORNIA STARTING THIS WEEKEND AND GOING
INTO NEXT WEEK AS A REX BLOCK. THIS WILL HELP TO BRING SEVERAL DAYS OF
GENERALLY SUNNY CONDITIONS WITH HIGHS GOING BACK TO ABOVE NORMAL
LEVELS. ONLY REAL FORECAST CONCERNS IS HOW MUCH OVERNIGHT
CLOUDS/PATCHY FOG WE WILL SEE PLUS HOW WARM IT WILL BECOME. AT
LEAST ONE DAY OF WIDESPREAD 80S AND 90S LOOK LIKELY FOR INTERIOR
SPOTS DURING THE SECOND HALF OF NEXT WEEK.
.PREVIOUS DISCUSSION...LIGHT RAIN SHOWERS CONTINUE MAINLY FROM
THE SAN FRANCISCO BAY SOUTHWARD THIS MORNING. IN THE LAST 3
HOURS...MUSTANG RIDGE IN MONTEREY COUNTY RECEIVED 0.08" WHILE THE
OAKLAND SOUTH RAWS RECEIVED 0.02" IN THAT SAME TIME FRAME. THE NAM
AND HRRR SEEM TO HAVE THE BEST HANDLE OF THE CURRENT SYNOPTIC
PATTERN...AND BOTH KEEP SCATTERED SHOWERS IN THE REGION THROUGH AT
LEAST 15Z. POPS WERE SIGNIFICANTLY INCREASED BETWEEN 12Z AND 18Z
TO ACCOUNT FOR THESE SHOWERS.
SKIES WERE CLOUDY OVERNIGHT...AS ABUNDANT MID AND LOW LEVEL
MOISTURE PREVAILED OVER THE REGION. TEMPERATURES SO FAR FELL INTO
THE 50S...SIMILAR TO THOSE OBSERVED LAST NIGHT. LOW CLOUDS WILL BE
LATE TO DISSIPATE AGAIN TODAY...AND A FEW PLACES MIGHT ONLY SEE
GLIMPSES OF BLUE SKY.
OTHERWISE...THE UPPER LEVEL LOW OVER SOUTHERN CALIFORNIA IS
FORECAST TO MOVE SLOWLY EAST NORTHEAST TOWARD SOUTHERN NV AND
NORTHERN AZ BY THIS AFTERNOON. THIS WILL RESULT IN DRY...BUT COOL
CONDITIONS OVER THE REGION. WHILE THE LOW MOVES EAST...AN UPPER
LEVEL SHORT WAVE WILL SKIRT NORTHERN CALIFORNIA...BRINGING A
SLIGHT CHANCE OF SHOWERS TO FAR NORTHERN SONOMA COUNTY.
HOWEVER...THE SHORT TERM MODELS KEEP BACKING OFF WITH REGARDS TO
PRECIPITATION WITH THIS DISTURBANCE...SO CONFIDENCE IS LOW THAT WE
WILL SEE ANY RAIN IN THIS REGION.
WEAK UPPER LEVEL RIDGING WILL BEGIN TO BUILD OVER THE REGION
DURING THE SECOND HALF OF THE WEEKEND. THIS WILL RESULT IN A
SIGNIFICANT WARMING TREND THROUGH THE AREA...WITH TEMPERATURES
NEARING NEAR NORMAL READINGS FOR THE MIDDLE OF OCTOBER.
EVEN MORE SIGNIFICANT WARMING IS FORECAST FOR THE MIDDLE OF NEXT
WEEK...WITH A 588 DM RIDGE NEARING CENTRAL CALIFORNIA. 850 MB
TEMPERATURES ARE FORECAST TO RISE OVER 11 DEGREES C BETWEEN THIS
AFTERNOON AND WEDNESDAY AFTERNOON. THIS WILL RESULT IN INLAND
TEMPERATURES REACHING THE 80S TO LOW 90S...WHILE THE COASTAL
LOCATIONS REACH THE UPPER 60S TO 70S.
THE CLIMATE PREDICTION CENTERS 6 TO 10 DAY OUTLOOK CALLS FOR
TEMPERATURES WELL ABOVE NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION...AS OF 4:45 AM FRIDAY...LIGHT SHOWERS CONTINUE THIS
MORNING...MOSTLY EAST OF THE TERMINALS THOUGH THERE HAVE BEEN
INTERMITTENT TRACES AT OAK AND SFO. SHOWERS WILL WIND DOWN LATER
THIS MORNING. CIGS MVFR NORTH OF SJC WHILE HOLDING ABOVE 3000
FROM THERE SOUTH. EXPECTING LATE CLEARING DUE TO LOW LEVEL
MOISTURE...LOW CONFIDENCE ON TIMING. LIGHT SEA BREEZE THIS AFTERNOON.
.VICINITY OF KSFO...MVFR CIGS THROUGH THE MORNING. LIGHT SHOWERS
POSSIBLE FOR THE NEXT FEW HOURS. CONDITIONS IMPROVE IN THE
AFTERNOON WITH SEA BREEZE TO AROUND 10 KT. EARLY RETURN POSSIBLE.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...CIGS 3000 TO 4000 FT THROUGH LATE
MORNING. LIGHT SEA BREEZE.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
&&
$$
PUBLIC FORECAST: BELL/RILEY
AVIATION/MARINE: AC
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
448 AM PDT FRI OCT 12 2012
.DISCUSSION...AS OF 3:35 AM PDT FRIDAY...LIGHT RAIN SHOWERS
CONTINUE MAINLY FROM THE SAN FRANCISCO BAY SOUTHWARD THIS
MORNING. IN THE LAST 3 HOURS...MUSTANG RIDGE IN MONTEREY COUNTY
RECEIVED 0.08" WHILE THE OAKLAND SOUTH RAWS RECEIVED 0.02" IN THAT
SAME TIME FRAME. THE NAM AND HRRR SEEM TO HAVE THE BEST HANDLE OF
THE CURRENT SYNOPTIC PATTERN...AND BOTH KEEP SCATTERED SHOWERS IN
THE REGION THROUGH AT LEAST 15Z. POPS WERE SIGNIFICANTLY INCREASED
BETWEEN 12Z AND 18Z TO ACCOUNT FOR THESE SHOWERS.
SKIES WERE CLOUDY OVERNIGHT...AS ABUNDANT MID AND LOW LEVEL
MOISTURE PREVAILED OVER THE REGION. TEMPERATURES SO FAR FELL INTO
THE 50S...SIMILAR TO THOSE OBSERVED LAST NIGHT. LOW CLOUDS WILL BE
LATE TO DISSIPATE AGAIN TODAY...AND A FEW PLACES MIGHT ONLY SEE
GLIMPSES OF BLUE SKY.
OTHERWISE...THE UPPER LEVEL LOW OVER SOUTHERN CALIFORNIA IS
FORECAST TO MOVE SLOWLY EAST NORTHEAST TOWARD SOUTHERN NV AND
NORTHERN AZ BY THIS AFTERNOON. THIS WILL RESULT IN DRY...BUT COOL
CONDITIONS OVER THE REGION. WHILE THE LOW MOVES EAST...AN UPPER
LEVEL SHORT WAVE WILL SKIRT NORTHERN CALIFORNIA...BRINGING A
SLIGHT CHANCE OF SHOWERS TO FAR NORTHERN SONOMA COUNTY.
HOWEVER...THE SHORT TERM MODELS KEEP BACKING OFF WITH REGARDS TO
PRECIPITATION WITH THIS DISTURBANCE...SO CONFIDENCE IS LOW THAT WE
WILL SEE ANY RAIN IN THIS REGION.
WEAK UPPER LEVEL RIDGING WILL BEGIN TO BUILD OVER THE REGION
DURING THE SECOND HALF OF THE WEEKEND. THIS WILL RESULT IN A
SIGNIFICANT WARMING TREND THROUGH THE AREA...WITH TEMPERATURES
NEARING NEAR NORMAL READINGS FOR THE MIDDLE OF OCTOBER.
EVEN MORE SIGNIFICANT WARMING IS FORECAST FOR THE MIDDLE OF NEXT
WEEK...WITH A 588 DM RIDGE NEARING CENTRAL CALIFORNIA. 850 MB
TEMPERATURES ARE FORECAST TO RISE OVER 11 DEGREES C BETWEEN THIS
AFTERNOON AND WEDNESDAY AFTERNOON. THIS WILL RESULT IN INLAND
TEMPERATURES REACHING THE 80S TO LOW 90S...WHILE THE COASTAL
LOCATIONS REACH THE UPPER 60S TO 70S.
THE CLIMATE PREDICTION CENTERS 6 TO 10 DAY OUTLOOK CALLS FOR
TEMPERATURES WELL ABOVE NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION...AS OF 4:45 AM FRIDAY...LIGHT SHOWERS CONTINUE THIS
MORNING...MOSTLY EAST OF THE TERMINALS THOUGH THERE HAVE BEEN
INTERMITTENT TRACES AT OAK AND SFO. SHOWERS WILL WIND DOWN LATER
THIS MORNING. CIGS MVFR NORTH OF SJC WHILE HOLDING ABOVE 3000
FROM THERE SOUTH. EXPECTING LATE CLEARING DUE TO LOW LEVEL
MOISTURE...LOW CONFIDENCE ON TIMING. LIGHT SEA BREEZE THIS AFTERNOON.
.VICINITY OF KSFO...MVFR CIGS THROUGH THE MORNING. LIGHT SHOWERS
POSSIBLE FOR THE NEXT FEW HOURS. CONDITIONS IMPROVE IN THE
AFTERNOON WITH SEA BREEZE TO AROUND 10 KT. EARLY RETURN POSSIBLE.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...CIGS 3000 TO 4000 FT THROUGH LATE
MORNING. LIGHT SEA BREEZE.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
&&
$$
PUBLIC FORECAST: RILEY
AVIATION/MARINE: AC
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
335 AM PDT FRI OCT 12 2012
.DISCUSSION...AS OF 3:35 AM PDT FRIDAY...LIGHT RAIN SHOWERS
CONTINUE MAINLY FROM THE SAN FRANCISCO BAY SOUTHWARD THIS
MORNING. IN THE LAST 3 HOURS...MUSTANG RIDGE IN MONTEREY COUNTY
RECEIVED 0.08" WHILE THE OAKLAND SOUTH RAWS RECEIVED 0.02" IN THAT
SAME TIME FRAME. THE NAM AND HRRR SEEM TO HAVE THE BEST HANDLE OF
THE CURRENT SYNOPTIC PATTERN...AND BOTH KEEP SCATTERED SHOWERS IN
THE REGION THROUGH AT LEAST 15Z. POPS WERE SIGNIFICANTLY INCREASED
BETWEEN 12Z AND 18Z TO ACCOUNT FOR THESE SHOWERS.
SKIES WERE CLOUDY OVERNIGHT...AS ABUNDANT MID AND LOW LEVEL
MOISTURE PREVAILED OVER THE REGION. TEMPERATURES SO FAR FELL INTO
THE 50S...SIMILAR TO THOSE OBSERVED LAST NIGHT. LOW CLOUDS WILL BE
LATE TO DISSIPATE AGAIN TODAY...AND A FEW PLACES MIGHT ONLY SEE
GLIMPSES OF BLUE SKY.
OTHERWISE...THE UPPER LEVEL LOW OVER SOUTHERN CALIFORNIA IS
FORECAST TO MOVE SLOWLY EAST NORTHEAST TOWARD SOUTHERN NV AND
NORTHERN AZ BY THIS AFTERNOON. THIS WILL RESULT IN DRY...BUT COOL
CONDITIONS OVER THE REGION. WHILE THE LOW MOVES EAST...AN UPPER
LEVEL SHORT WAVE WILL SKIRT NORTHERN CALIFORNIA...BRINGING A
SLIGHT CHANCE OF SHOWERS TO FAR NORTHERN SONOMA COUNTY.
HOWEVER...THE SHORT TERM MODELS KEEP BACKING OFF WITH REGARDS TO
PRECIPITATION WITH THIS DISTURBANCE...SO CONFIDENCE IS LOW THAT WE
WILL SEE ANY RAIN IN THIS REGION.
WEAK UPPER LEVEL RIDGING WILL BEGIN TO BUILD OVER THE REGION
DURING THE SECOND HALF OF THE WEEKEND. THIS WILL RESULT IN A
SIGNIFICANT WARMING TREND THROUGH THE AREA...WITH TEMPERATURES
NEARING NEAR NORMAL READINGS FOR THE MIDDLE OF OCTOBER.
EVEN MORE SIGNIFICANT WARMING IS FORECAST FOR THE MIDDLE OF NEXT
WEEK...WITH A 588 DM RIDGE NEARING CENTRAL CALIFORNIA. 850 MB
TEMPERATURES ARE FORECAST TO RISE OVER 11 DEGREES C BETWEEN THIS
AFTERNOON AND WEDNESDAY AFTERNOON. THIS WILL RESULT IN INLAND
TEMPERATURES REACHING THE 80S TO LOW 90S...WHILE THE COASTAL
LOCATIONS REACH THE UPPER 60S TO 70S.
THE CLIMATE PREDICTION CENTERS 6 TO 10 DAY OUTLOOK CALLS FOR
TEMPERATURES WELL ABOVE NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION...AS OF 10:30 PM THURSDAY...LARGE STRATUS FIELD
CONTINUES OVER THE AREA. MVFR CIGS ALL TERMINALS THROUGH THE
NIGHT.
.VICINITY OF KSFO...MVFR CIGS THROUGH FRIDAY MORNING. SOUTHWEST
WINDS TO 10 KT.
KSFO BRIDGE APPROACH...MVFR CIGS THROUGH FRIDAY MORNING.
MONTEREY BAY AREA TERMINALS...MVFR CIGS THROUGH EARLY FRIDAY
AFTERNOON.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
&&
$$
PUBLIC FORECAST: RILEY
AVIATION/MARINE: W PI
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AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
915 PM PDT THU OCT 11 2012
.UPDATE...
BAND IS FORMING OVER CENTRAL NEVADA AND IS NOW MOVING WEST. NEW
NAM/GFS IN GOOD AGREEMENT HITTING CHURCHILL COUNTY HARD AND
WESTWARD INTO DOUGLAS COUNTY BY 12Z. LATEST HRRR REALLY DOES NOT
HAVE A SECOND BAND, BUT GIVEN THE CONSISTENCY OF THE GFS/NAM WILL
GO IN THEIR DIRECTION. HAVE INCREASED COVERAGE AGAIN FOR THE
OVERNIGHT HOURS SOUTH OF I-80 HITTING THE HWY 50 CORRIDOR HARDEST
WITH THE SECOND BAND. NOT SURE ABOUT THE AMOUNTS FROM THE NAM/GFS
SHOWING UP TO 1/2 INCH, BUT AMOUNTS OF A TENTH TO QUARTER INCH IN
THE BAND LOOK REASONABLE. ALSO INCREASED CLOUD COVER FOR THE
REMAINDER OF THE NIGHT FOR MOST AREAS.
ALSO MADE SOME SMALL CHANGES TO FRIDAY MORNING AS THE BAND
DISSIPATES. INCREASED COVERAGE FROM FERNLEY SOUTH-SOUTHWESTWARD TO
MARKLEEVILLE AND COLEVILLE. MODELS HOLD ONTO THE BAND UNTIL ALMOST
18Z AS IT WEAKENS. SNOW LEVELS REMAIN HIGH AND 8500 TO 9500 FEET
SO ONLY THE HIGHEST PEAKS WILL SEE ANY SNOW.
&&
.PREVIOUS DISCUSSION... /ISSUED 624 PM PDT THU OCT 11 2012/
UPDATE...
LARGE BAND OF SHOWERS AND ISOLATED THUNDERSTORMS IS NOW MOVING
INTO MINERAL COUNTY AND SOON INTO MONO COUNTY. HRRR SEEMS TO BE
HANDLING THIS FAIRLY WELL RIGHT NOW AND LIKE ITS IDEAS OF
WIDESPREAD SHOWERS THIS EVENING DOWN THERE. HAVE UPDATED TO
INCREASE POPS AND SHOWER COVERAGE FOR MOST OF MONO AND MINERAL
COUNTIES. ALSO BOOSTED QPF A BIT AVERAGE AMOUNTS LIKELY TO BE A
TENTH TO QUARTER INCH.
FURTHER NORTH, SOME SHOWERS ARE MOVING INTO EASTERN CHURCHILL AND
PERSHING COUNTIES AND APPEAR TO BE MORE SCATTERED AT THIS TIME.
WILL CONTINUE TO MONITOR CENTRAL NV DEVELOPMENT THIS EVENING AS A
SECOND BAND IS FORECAST TO DEVELOP FOR PORTIONS OF WEST CENTRAL
NEVADA. EXPECT TO BE UPDATING AGAIN WHEN THE HARDEST HIT AREAS
BECOME CLEARER. MOST LIKELY IT IS LOOKING LIKE THE LOVELOCK-
FERNLEY-MINDEN AREAS TO GET THE BRUNT OF IT RIGHT NOW. COULD SEE A
QUARTER INCH OF RAIN IN THIS SECOND BAND WITH LOCALLY HIGHER
AMOUNTS. WALLMANN
PREVIOUS DISCUSSION... /ISSUED 246 PM PDT THU OCT 11 2012/
SHORT TERM...
UPPER LOW OVER SOCAL TODAY CONTINUES TO SLING ANOMALOUS AMOUNTS
OF MOISTURE UP INTO NV, WITH GEFS PRECIP WATER ANOMALIES 3-4
STANDARD DEVIATIONS ABOVE NORMAL. DEFORMATION ZONE HELPED PRODUCE
WIDESPREAD AREA OF SHOWERS SOUTH OF HWY 50 EARLIER TODAY WITH
SNOW DOWN TO ~7 KFT FROM TIME TO TIME NEAR MAMMOTH. RECENT HRRR
HIGH RESOLUTION RUNS SHOW SHOWER ACTIVITY CONTINUING THIS EVENING
MAINLY SOUTH OF HWY 50, WITH EVEN SOME TSTM POTENTIAL. WILL
FOLLOW THIS GUIDANCE AND ALSO KEEP CHC OF SHOWERS INTO RENO/GREAT
BASIN AREAS BASED ON UPSTREAM RADAR TRENDS OVER CENTRAL NV.
PRIMARY CHALLENGE IS FOR LATE TONIGHT AND TOMORROW, AS ALL MODELS
DEVELOP A ROUGHLY N-S ORIENTED FRONTOGENETIC BAND OF PRECIP OVER
THE FORECAST AREA BUT POSITION IT IN A VARIETY OF LOCATIONS.
SHOULD NAM/SREF VERIFY THEN RENO/CARSON AREAS COULD GET A BURST OF
APPRECIABLE RAIN (SREF HAS 15-25% CHC OF 0.25" 6-12Z TONIGHT),
WHILE GFS/EC IS FURTHER EAST OVER GREAT BASIN. HAVE ATTEMPTED TO
INCORPORATE BOTH THESE POSSIBILITIES SINCE I HAVE NO REASON TO
FAVOR ONE OVER THE OTHER AT THIS TIME. SO FORECAST CONFIDENCE IS
SOMEWHAT LOW TO MODERATE FOR THIS PERIOD.
LOW EXPECTED TO TRANSLATE EASTWARD LATE FRI, WITH SHORTWAVE
RIDGING BUILDING IN OVER THE AREA SAT/SUN WITH WARMING TEMPS.
IMPRESSIVE 185KT JET AND ATMOSPHERIC RIVER EXPECTED TO CRASH
ONSHORE INTO THE PAC NW STARTING SUN/MON. MODELS HAVE TRENDED
DRIER FOR NE CA AND NW NV SO HAVE BACKED DOWN ON SHOWERS THERE,
BUT WITH PROXIMITY TO ACTIVE JET A FEW LIGHT SHOWERS CANNOT BE
RULED OUT SUN NIGHT.
CS
LONG TERM...MONDAY THROUGH THURSDAY...
SHORTWAVE AND PACIFIC JET MOVING ACROSS THE NORTHWEST US ON
MONDAY WILL KEEP NEARLY ALL PRECIP NORTH OF THE OREGON BORDER,
EXCEPT FOR A FEW LIGHT RAIN SHOWERS POSSIBLE IN FAR NORTHWEST NV
AND THE SURPRISE VALLEY. OTHERWISE, DRY CONDITIONS WILL PREVAIL
WITH SOME INCREASE IN WEST WINDS MONDAY AFTERNOON-EVENING AS THE
SHORTWAVE BRUSHES ACROSS NORTHERN NV. FOR THE REMAINDER OF NEXT
WEEK, MEDIUM RANGE GUIDANCE IS IN GOOD AGREEMENT WITH REBUILDING
FLAT RIDGE OVER CA-NV, KEEPING THE REGION DRY WITH LIGHTER WINDS
AND LESS CLOUD COVERAGE. MAX TEMPS FOR MON-THURS WILL BE ABOUT
5-10 DEGREES ABOVE NORMAL, WITH MID 70S TO NEAR 80 DEGREES IN
WESTERN NV AND MID-UPPER 60S IN THE TAHOE BASIN. MJD
AVIATION...
FOR KRNO-KTVL-KTRK, VFR CONDS WITH WIDESPREAD CIGS OF 4000-8000
FT AGL ARE EXPECTED THRU 06Z THIS EVE WITH ISOLD BANDS OF LIGHT
RAIN AND SHOWERS THIS EVE PRODUCING BRIEF MVFR CIGS. A LARGER BAND
OF STEADY MODERATE RAIN IS POSSIBLE LATE TONIGHT THRU FRI MORNING.
THE LOCATION OF THIS BAND REMAINS UNCERTAIN BUT IS MOST LIKELY TO
AFFECT WEST CENTRAL NV. SOME GUIDANCE DATA DOES EXTEND THIS BAND
WEST INTO KRNO AND THE TAHOE BASIN SO WILL KEEP SOME PROB30/TEMPO
MENTION FOR A FEW HOURS AROUND 12Z.
FOR KMMH, ADDITIONAL WRAP AROUND RAIN BANDS ARE POSSIBLE THIS
EVENING AND AGAIN ON FRIDAY PRODUCING MVFR CIGS AT TIMES, BUT SNOW
IS UNLIKELY DURING THE OPERATIONAL HOURS AT KMMH THIS EVENING AND
FRIDAY. MJD
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
236 PM EDT FRI OCT 12 2012
.PREV DISCUSSION... /ISSUED 758 AM EDT FRI OCT 12 2012/
PREV DISCUSSION... /ISSUED 513 AM EDT FRI OCT 12 2012/
UPDATE...
MCS TRACKING SOUTHEASTWARD ACROSS CENTRAL TN SHOULD BEGIN TO
INFLUENCE NORTHERN GEORGIA FROM THE NW AS EARLY AS 11Z. SCATTERED
THUNDERSTORM DEVELOPMENT HAS BEEN PERSISTENT OVERNIGHT AND BASED
ON RAP ANALYSIS OF MUCAPE...COMPLEX HAS BEEN RIDING ALONG AN
ELEVATED INSTABILITY AXIS. IT IS STILL EXPECTED TO BECOME LESS
ORGANIZED AND DISSIPATE MOSTLY AFTER 15Z...THOUGH HAVE INCLUDED
ISOLATED TO SCATTERED THUNDER ACROSS PARTS OF THE NORTH. BEST
CHANCE FOR ANY THUNDERSTORMS SHOULD STAY NORTH OF ATLANTA AND
EVENTUALLY BECOME MORE ISOLATED IN COVERAGE INTO MID MORNING. THE
MAIN THREATS WITH ANY THUNDERSTORM WILL BE OCCASIONAL
LIGHTNING...GUSTY WINDS...AND HEAVY RAINFALL. PREVIOUS DISCUSSION
FOLLOWS...
BAKER
PREV DISCUSSION... /ISSUED 420 AM EDT FRI OCT 12 2012/
SHORT TERM /TODAY THROUGH SATURDAY/...
CLOUD DECK AND VERY ISOLATED SHOWER DEVELOPMENT ADVECTING INTO
NORTHERN GEORGIA EARLY THIS MORNING HAS LIMITED RADIATIONAL COOLING
SO HAVE THUS RAISED MIN TEMPS BY A FEW DEGREES. MCS CURRENTLY ACROSS
WESTERN KY AND FAR NORTHWESTERN TN IS TRACKING SOUTHEASTWARD IN
ASSOCIATION WITH SOUTHERN EXTENT OF LOW AMPLITUDE UPPER SHORTWAVE
TROUGH. THERE IS A SLIM CHANCE THAT SOME ISOLATED THUNDER COULD
REACH INTO THE FAR NORTHEASTERN PORTION OF THE AREA SHORTLY BEFORE
12Z WITH THE MCS REMNANTS...HOWEVER PROGGED MUCAPE STAYS LOW AND RAP
ANALYSIS HAS COMPLEX TRACKING INTO A MORE STABLE ENVIRONMENT SO WILL
LEAVE CHANCE POPS FOR SHOWERS THROUGH MORNING. HOWEVER...WILL
CLOSELY MONITOR PROGRESSION OF THIS SYSTEM AND UPDATE AS SEEN FIT.
SUITE OF SHORT RANGE MODEL SOLUTIONS GENERALLY AGREE WITH PRECIP
ACROSS NW GEORGIA MAINLY FROM 10-15Z...THOUGH LOOKS TO BE LIMITED IN
COVERAGE AND GREATLY TAPERS OFF INTO THE AFTERNOON AS THE BEST UPPER
LEVEL DYNAMICS STAY REMOVED FROM THE MOISTURE AND WELL NORTH OF THE
REGION. WILL THEREFORE CARRY CHANCE POPS INITIALLY NW TO SLIGHT POPS
BY AFTERNOON AND FURTHER SOUTH INTO WESTERN CENTRAL GEORGIA.
INSTABILITY CONTINUES TO BE LIMITED SO WILL STILL ONLY HAVE SHOWER
POTENTIAL THROUGH AFTERNOON.
CLASSIC CAD EVENT SETS UP FOR SATURDAY WITH 1033-MB PARENT SFC HIGH
PROGGED TO BE CENTERED OVER NEW ENGLAND/MID ATLANTIC REGION BY 12Z.
RESULTANT WEDGE SHOULD LIMIT MAX TEMPS FROM NEAR 70 DEGREES IN THE
NORTHEAST PORTION TO NEAR 80 IN THE SOUTH. GENERALLY A BLEND OF
BIASED CORRECTED MET AND MAV GUIDANCE LOOKED REASONABLE FOR PROGGED
TEMPS THROUGH PERIOD.
BAKER
LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
EXTENDED PERIOD BEGINS WITH A SHORTWAVE MOVING THROUGH THE
MISSOURI VALLEY NORTHEAST INTO THE OHIO VALLEY. TRAILING RESIDUAL
ENERGY WILL PUSH INTO THE AREA SUNDAY NIGHT INTO MONDAY WITH A
BROKEN LINE OF SHOWERS AND EMBEDDED THUNDERSTORMS THE RESULT.
INSTABILITY SUFFICIENT FOR STORM DEVELOPMENT BUT MOST SIGNIFICANT
SHEAR LIFTS NORTH OF THE AREA SO EXPECTING NOTHING SIGNIFICANT
LOCALLY AT THIS POINT. HIGH PRESSURE WILL THEN BUILD IN BEHIND THE
FRONT BUT LARGELY ZONAL FLOW WILL KEEP TEMPS ELEVATED THROUGH MID
WEEK.
EXTENDED GUIDANCE COMING INTO BETTER AGREEMENT WRT NEXT MAJOR
SYSTEM SLATED FOR THU. MAIN LOW TO LIFT WELL NORTH OVER THE GREAT
LAKES REGION BUT UPPER TROUGH EXTENDS WELL INTO THE GULF AND WITH
A SPLIT FLOW PATTERN AT THE JET STREAM LEVEL...MODELS HAVE NO
TROUBLE GENERATING PRECIP AREAWIDE. WILL HOLD AT HIGH END CHANCE
FOR NOW THIS FAR OUT AND THE FACT THAT THIS IS THE FIRST RUN
MODELS HAVE SHOWN THIS TYPE OF CONSENSUS.
DEESE
&&
.AVIATION...
18Z UPDATE...
MID TO HIGH LEVEL CLOUDS OVER THE AREA BUT THEY ARE SCT OUT AND
LIFTING THROUGH THIS EVENING. MAY SEE SOME SCT TO BKN CLOUDS
FORMING ACROSS THE AREA OVER NIGHT IN THE 4000FT RANGE BUT NOTHING
THAT WOULD CAUSE ANY AVIATION CONCERNS. WINDS ARE STILL OUT OF
THE NW BUT THEY WILL BE TURNING TO THE NE AND THEN EAST THROUGH
SAT AFTERNOON. WINDS SPEEDS ARE IN THE 8-12KT RANGE NOW BUT THEY
WILL DIMINISH AFTER SUNSET. WINDS WILL PICK BACK UP AGAIN SAT. NO
PRECIPITATION OR RESTRICTIONS TO VSBYS EXPECTED.
//ATL CONFIDENCE...18Z UPDATE...
CONFIDENCE HIGH ON ALL ELEMENTS.
01
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 78 53 73 50 / 20 5 5 0
ATLANTA 79 57 73 56 / 20 5 5 0
BLAIRSVILLE 69 48 69 47 / 30 0 0 5
CARTERSVILLE 77 52 74 52 / 30 5 0 5
COLUMBUS 85 60 81 60 / 20 5 0 0
GAINESVILLE 74 54 71 52 / 30 5 5 0
MACON 83 56 80 53 / 10 5 5 0
ROME 76 52 78 51 / 30 0 0 5
PEACHTREE CITY 79 55 77 51 / 20 5 5 0
VIDALIA 84 60 79 59 / 5 0 0 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...01
LONG TERM....31
AVIATION...01
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
758 AM EDT FRI OCT 12 2012
.PREV DISCUSSION... /ISSUED 513 AM EDT FRI OCT 12 2012/
.UPDATE...
MCS TRACKING SOUTHEASTWARD ACROSS CENTRAL TN SHOULD BEGIN TO
INFLUENCE NORTHERN GEORGIA FROM THE NW AS EARLY AS 11Z. SCATTERED
THUNDERSTORM DEVELOPMENT HAS BEEN PERSISTENT OVERNIGHT AND BASED
ON RAP ANALYSIS OF MUCAPE...COMPLEX HAS BEEN RIDING ALONG AN
ELEVATED INSTABILITY AXIS. IT IS STILL EXPECTED TO BECOME LESS
ORGANIZED AND DISSIPATE MOSTLY AFTER 15Z...THOUGH HAVE INCLUDED
ISOLATED TO SCATTERED THUNDER ACROSS PARTS OF THE NORTH. BEST
CHANCE FOR ANY THUNDERSTORMS SHOULD STAY NORTH OF ATLANTA AND
EVENTUALLY BECOME MORE ISOLATED IN COVERAGE INTO MID MORNING. THE
MAIN THREATS WITH ANY THUNDERSTORM WILL BE OCCASIONAL
LIGHTNING...GUSTY WINDS...AND HEAVY RAINFALL. PREVIOUS DISCUSSION
FOLLOWS...
BAKER
&&
.PREV DISCUSSION... /ISSUED 420 AM EDT FRI OCT 12 2012/
.SHORT TERM /TODAY THROUGH SATURDAY/...
CLOUD DECK AND VERY ISOLATED SHOWER DEVELOPMENT ADVECTING INTO
NORTHERN GEORGIA EARLY THIS MORNING HAS LIMITED RADIATIONAL COOLING
SO HAVE THUS RAISED MIN TEMPS BY A FEW DEGREES. MCS CURRENTLY ACROSS
WESTERN KY AND FAR NORTHWESTERN TN IS TRACKING SOUTHEASTWARD IN
ASSOCIATION WITH SOUTHERN EXTENT OF LOW AMPLITUDE UPPER SHORTWAVE
TROUGH. THERE IS A SLIM CHANCE THAT SOME ISOLATED THUNDER COULD
REACH INTO THE FAR NORTHEASTERN PORTION OF THE AREA SHORTLY BEFORE
12Z WITH THE MCS REMNANTS...HOWEVER PROGGED MUCAPE STAYS LOW AND RAP
ANALYSIS HAS COMPLEX TRACKING INTO A MORE STABLE ENVIRONMENT SO WILL
LEAVE CHANCE POPS FOR SHOWERS THROUGH MORNING. HOWEVER...WILL
CLOSELY MONITOR PROGRESSION OF THIS SYSTEM AND UPDATE AS SEEN FIT.
SUITE OF SHORT RANGE MODEL SOLUTIONS GENERALLY AGREE WITH PRECIP
ACROSS NW GEORGIA MAINLY FROM 10-15Z...THOUGH LOOKS TO BE LIMITED IN
COVERAGE AND GREATLY TAPERS OFF INTO THE AFTERNOON AS THE BEST UPPER
LEVEL DYNAMICS STAY REMOVED FROM THE MOISTURE AND WELL NORTH OF THE
REGION. WILL THEREFORE CARRY CHANCE POPS INITIALLY NW TO SLIGHT POPS
BY AFTERNOON AND FURTHER SOUTH INTO WESTERN CENTRAL GEORGIA.
INSTABILITY CONTINUES TO BE LIMITED SO WILL STILL ONLY HAVE SHOWER
POTENTIAL THROUGH AFTERNOON.
CLASSIC CAD EVENT SETS UP FOR SATURDAY WITH 1033-MB PARENT SFC HIGH
PROGGED TO BE CENTERED OVER NEW ENGLAND/MID ATLANTIC REGION BY 12Z.
RESULTANT WEDGE SHOULD LIMIT MAX TEMPS FROM NEAR 70 DEGREES IN THE
NORTHEAST PORTION TO NEAR 80 IN THE SOUTH. GENERALLY A BLEND OF
BIASED CORRECTED MET AND MAV GUIDANCE LOOKED REASONABLE FOR PROGGED
TEMPS THROUGH PERIOD.
BAKER
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
EXTENDED PERIOD BEGINS WITH A SHORTWAVE MOVING THROUGH THE
MISSOURI VALLEY NORTHEAST INTO THE OHIO VALLEY. TRAILING RESIDUAL
ENERGY WILL PUSH INTO THE AREA SUNDAY NIGHT INTO MONDAY WITH A
BROKEN LINE OF SHOWERS AND EMBEDDED THUNDERSTORMS THE RESULT.
INSTABILITY SUFFICIENT FOR STORM DEVELOPMENT BUT MOST SIGNIFICANT
SHEAR LIFTS NORTH OF THE AREA SO EXPECTING NOTHING SIGNIFICANT
LOCALLY AT THIS POINT. HIGH PRESSURE WILL THEN BUILD IN BEHIND THE
FRONT BUT LARGELY ZONAL FLOW WILL KEEP TEMPS ELEVATED THROUGH MID
WEEK.
EXTENDED GUIDANCE COMING INTO BETTER AGREEMENT WRT NEXT MAJOR
SYSTEM SLATED FOR THU. MAIN LOW TO LIFT WELL NORTH OVER THE GREAT
LAKES REGION BUT UPPER TROUGH EXTENDS WELL INTO THE GULF AND WITH
A SPLIT FLOW PATTERN AT THE JET STREAM LEVEL...MODELS HAVE NO
TROUBLE GENERATING PRECIP AREAWIDE. WILL HOLD AT HIGH END CHANCE
FOR NOW THIS FAR OUT AND THE FACT THAT THIS IS THE FIRST RUN
MODELS HAVE SHOWN THIS TYPE OF CONSENSUS.
DEESE
&&
.AVIATION...
12Z UPDATE...
INITIAL MVFR CIGS NEAR 3 KFT IMPROVING TO VFR LEVELS AROUND 4 KFT AFTER
16Z FOR KATL AND OTHER NORTHERN SITES WITH SLIGHTLY HIGHER LEVELS
LIKELY NEAR KMCN AND KCSG. MCS REMNANTS LOOK TO CONTINUE WEAKENING SO
THERE COULD BE SOME VCSH NEAR KATL AND OTHER NORTHERN SITES FROM
14-16Z...THOUGH THUNDER THREAT LOOKS TO BE TOO LOW TO INCLUDE.
WINDS SHOULD STAY NW AT 10KTS OR LESS WITH SLIGHTLY HIGHER AT KATL
AFTER AROUND 18Z. WINDS SHOULD SHIFT TO NE NEAR 05Z SATURDAY AND
SOME CIG LOWERING IS POSSIBLE AS CAD WEDGE BUILDS IN...THOUGH WILL
INCLUDE SCT025 FOR NOW AND AMEND AS MORE INFORMATION BECOMES AVAILABLE.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM CONFIDENCE ON CIGS OVERNIGHT.
HIGH CONFIDENCE ALL ELSE.
BAKER
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 78 55 72 46 / 20 10 5 0
ATLANTA 79 57 74 52 / 20 10 5 10
BLAIRSVILLE 69 49 68 45 / 30 5 5 5
CARTERSVILLE 77 53 75 48 / 30 10 5 10
COLUMBUS 85 63 80 56 / 20 20 5 10
GAINESVILLE 74 56 70 49 / 30 5 5 10
MACON 83 59 80 49 / 10 10 5 0
ROME 76 54 77 48 / 30 10 5 10
PEACHTREE CITY 79 58 75 48 / 20 20 5 10
VIDALIA 84 63 79 55 / 5 5 5 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BAKER
LONG TERM....DEESE
AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
513 AM EDT FRI OCT 12 2012
.UPDATE...
MCS TRACKING SOUTHEASTWARD ACROSS CENTRAL TN SHOULD BEGIN TO
INFLUENCE NORTHERN GEORGIA FROM THE NW AS EARLY AS 11Z. SCATTERED
THUNDERSTORM DEVELOPMENT HAS BEEN PERSISTENT OVERNIGHT AND BASED
ON RAP ANALYSIS OF MUCAPE...COMPLEX HAS BEEN RIDING ALONG AN
ELEVATED INSTABILITY AXIS. IT IS STILL EXPECTED TO BECOME LESS
ORGANIZED AND DISSIPATE MOSTLY AFTER 15Z...THOUGH HAVE INCLUDED
ISOLATED TO SCATTERED THUNDER ACROSS PARTS OF THE NORTH. BEST
CHANCE FOR ANY THUNDERSTORMS SHOULD STAY NORTH OF ATLANTA AND
EVENTUALLY BECOME MORE ISOLATED IN COVERAGE INTO MID MORNING. THE
MAIN THREATS WITH ANY THUNDERSTORM WILL BE OCCASIONAL
LIGHTNING...GUSTY WINDS...AND HEAVY RAINFALL. PREVIOUS DISCUSSION
FOLLOWS...
BAKER
&&
.PREV DISCUSSION... /ISSUED 420 AM EDT FRI OCT 12 2012/
.SHORT TERM /TODAY THROUGH SATURDAY/...
CLOUD DECK AND VERY ISOLATED SHOWER DEVELOPMENT ADVECTING INTO
NORTHERN GEORGIA EARLY THIS MORNING HAS LIMITED RADIATIONAL COOLING
SO HAVE THUS RAISED MIN TEMPS BY A FEW DEGREES. MCS CURRENTLY ACROSS
WESTERN KY AND FAR NORTHWESTERN TN IS TRACKING SOUTHEASTWARD IN
ASSOCIATION WITH SOUTHERN EXTENT OF LOW AMPLITUDE UPPER SHORTWAVE
TROUGH. THERE IS A SLIM CHANCE THAT SOME ISOLATED THUNDER COULD
REACH INTO THE FAR NORTHEASTERN PORTION OF THE AREA SHORTLY BEFORE
12Z WITH THE MCS REMNANTS...HOWEVER PROGGED MUCAPE STAYS LOW AND RAP
ANALYSIS HAS COMPLEX TRACKING INTO A MORE STABLE ENVIRONMENT SO WILL
LEAVE CHANCE POPS FOR SHOWERS THROUGH MORNING. HOWEVER...WILL
CLOSELY MONITOR PROGRESSION OF THIS SYSTEM AND UPDATE AS SEEN FIT.
SUITE OF SHORT RANGE MODEL SOLUTIONS GENERALLY AGREE WITH PRECIP
ACROSS NW GEORGIA MAINLY FROM 10-15Z...THOUGH LOOKS TO BE LIMITED IN
COVERAGE AND GREATLY TAPERS OFF INTO THE AFTERNOON AS THE BEST UPPER
LEVEL DYNAMICS STAY REMOVED FROM THE MOISTURE AND WELL NORTH OF THE
REGION. WILL THEREFORE CARRY CHANCE POPS INITIALLY NW TO SLIGHT POPS
BY AFTERNOON AND FURTHER SOUTH INTO WESTERN CENTRAL GEORGIA.
INSTABILITY CONTINUES TO BE LIMITED SO WILL STILL ONLY HAVE SHOWER
POTENTIAL THROUGH AFTERNOON.
CLASSIC CAD EVENT SETS UP FOR SATURDAY WITH 1033-MB PARENT SFC HIGH
PROGGED TO BE CENTERED OVER NEW ENGLAND/MID ATLANTIC REGION BY 12Z.
RESULTANT WEDGE SHOULD LIMIT MAX TEMPS FROM NEAR 70 DEGREES IN THE
NORTHEAST PORTION TO NEAR 80 IN THE SOUTH. GENERALLY A BLEND OF
BIASED CORRECTED MET AND MAV GUIDANCE LOOKED REASONABLE FOR PROGGED
TEMPS THROUGH PERIOD.
BAKER
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
EXTENDED PERIOD BEGINS WITH A SHORTWAVE MOVING THROUGH THE
MISSOURI VALLEY NORTHEAST INTO THE OHIO VALLEY. TRAILING RESIDUAL
ENERGY WILL PUSH INTO THE AREA SUNDAY NIGHT INTO MONDAY WITH A
BROKEN LINE OF SHOWERS AND EMBEDDED THUNDERSTORMS THE RESULT.
INSTABILITY SUFFICIENT FOR STORM DEVELOPMENT BUT MOST SIGNIFICANT
SHEAR LIFTS NORTH OF THE AREA SO EXPECTING NOTHING SIGNIFICANT
LOCALLY AT THIS POINT. HIGH PRESSURE WILL THEN BUILD IN BEHIND THE
FRONT BUT LARGELY ZONAL FLOW WILL KEEP TEMPS ELEVATED THROUGH MID WEEK.
EXTENDED GUIDANCE COMING INTO BETTER AGREEMENT WRT NEXT MAJOR
SYSTEM SLATED FOR THU. MAIN LOW TO LIFT WELL NORTH OVER THE GREAT
LAKES REGION BUT UPPER TROUGH EXTENDS WELL INTO THE GULF AND WITH
A SPLIT FLOW PATTERN AT THE JET STREAM LEVEL...MODELS HAVE NO
TROUBLE GENERATING PRECIP AREAWIDE. WILL HOLD AT HIGH END CHANCE
FOR NOW THIS FAR OUT AND THE FACT THAT THIS IS THE FIRST RUN
MODELS HAVE SHOWN THIS TYPE OF CONSENSUS.
DEESE
&&
.AVIATION...
06Z UPDATE... VFR CONDITIONS EXPECTED THROUGH PERIOD.
CIGS SHOULD GRADUALLY INCREASE IN COVERAGE AND LOWER TO NEAR
BKN040 EARLY THIS MORNING FROM NORTH TO SOUTH AND PERSIST INTO
MIDDAY FRIDAY. AFTER 18Z MOST SITES SHOULD TRANSITION TO AROUND
SCT040 AND BKN150...THEN REDUCE SOME IN COVERAGE BY EVENING. CALM
WINDS INITIALLY SHOULD BECOME NW BY 14Z AND AROUND 10KTS OR LESS
WITH SLIGHTLY HIGHER AT KATL BY EARLY AFTERNOON. LOOK TO SEE A
SHIFT TO NE WINDS NEAR 06Z SATURDAY CLOSER TO END OF FORECAST
PERIOD. THERE IS A SLIGHT CHANCE FOR SOME SHOWERS DURING THE
DAYTIME HOURS...HOWEVER GREATEST CHANCE SHOULD STAY NW OF TAF
SITES...THEREFORE DID NOT INCLUDE MENTION.
//ATL CONFIDENCE...06Z UPDATE...
HIGH CONFIDENCE ALL ELEMENTS.
BAKER
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 78 55 72 46 / 20 10 5 0
ATLANTA 79 57 74 52 / 20 10 5 10
BLAIRSVILLE 69 49 68 45 / 30 5 5 5
CARTERSVILLE 77 53 75 48 / 30 10 5 10
COLUMBUS 85 63 80 56 / 20 20 5 10
GAINESVILLE 74 56 70 49 / 30 5 5 10
MACON 83 59 80 49 / 10 10 5 0
ROME 76 54 77 48 / 30 10 5 10
PEACHTREE CITY 79 58 75 48 / 20 20 5 10
VIDALIA 84 63 79 55 / 5 5 5 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BAKER
LONG TERM....DEESE
AVIATION...BAKER
AREA FORECAST DISCUSSION...CORRECTION
NWS LINCOLN IL
330 AM CDT FRI OCT 12 2012
.DISCUSSION...
ISSUED 330 AM CDT FRI OCT 12 2012
SHORT TERM...TODAY THROUGH SUNDAY NIGHT
A FRONTAL BOUNDARY FROM CENTRAL INDIANA INTO SE IL JUST SE OF I-70
AND INTO SOUTHERN MO TO CONTINUE PRESSING SOUTHWARD THROUGH
SOUTHERN IL THIS MORNING AND KEEPING ITS CHANCES OF SHOWERS SOUTH
OF CENTRAL/SE IL. HAD A FEW SPRINKLES EARLIER TONIGHT IN PARTS OF
CENTRAL IL WITH A FEW LIGHT RAIN SHOWERS IN FAR SE IL AND THATS
ABOUT IT. 1032 MB HIGH PRESSURE OVER MN TO DRIFT EAST TOWARD LAKE MI
BY 18Z/1 PM TODAY AND TO LAKE ERIE BY 00Z/7 PM EARLY THIS EVENING.
SOME PATCHES OF MID LEVEL CLOUDS OVER SE IL AND THE IL RIVER
VALLEY TO DECREASE DURING THE MORNING GIVING WAY TO PARTLY TO
MOSTLY SUNNY SKIES TODAY. HIGHS TO BE IN THE UPPER 50S AND LOWER
60S WITH COOLEST READINGS FROM I-74 NORTH...THOUGH NEAR 65 BY
LAWRENCEVILLE.
STRONG 560 DM 500 MB LOW OVER SOUTHERN CA TO EJECT NE INTO THE
CENTRAL PLAINS BY MIDNIGHT SAT NIGHT AND TO LAKE MI BY SUNDAY
AFTERNOON. SURFACE LOW TO DEVELOP OVER EASTERN CO BY MIDNIGHT
TONIGHT AND MOVE INTO THE CENTRAL PLAINS BY MIDNIGHT SAT NIGHT
AND LIFT NE INTO THE WESTERN GREAT LAKES BY 18Z/1 PM SUNDAY.
MODELS CONTINUE SLOWER TREND WITH THIS STRONG STORM SYSTEM AND
SPC CONTINUES SLIGHT RISK OF SEVERE STORMS FROM I-55 NW OVERNIGHT
SAT NIGHT FOR MAINLY DAMAGING WIND GUSTS. STRONG WINDS AIDED BY
50-60KT LOW LEVEL JET AND DEEP MOISTURE AND STRONG WIND SHEAR.
CONTINUED HIGH POPS OVER NORTHERN/NW COUNTIES LATER FRI NIGHT AND
SAT WHILE AREAS SOUTH OF I-72 MAINLY DRY WITH SLIGHT CHANCE OF
CONVECTION AT BEST WHILE SE IL LIKELY REMAINS DRY UNTIL LATER
SAT NIGHT. BEST CHANCES OF CONVECTION WILL BE SAT NIGHT...THOUGH NOT
GETTING INTO SE IL UNTIL LATER SAT NIGHT INTO SUNDAY MORNING. SPC
ALSO HAS SLIGHT RISK OF SEVERE STORMS SE OF DECATUR SUNDAY FOR
MAINLY HAIL PER DAY3 OUTLOOK WHILE POSSIBLE SQUALL LINE SUNDAY WILL
BE EAST OF IL OVER INDIANA. MUCH WARMER HIGHS OF 75-80F SAT AND MORE
HUMID WITH MILDER LOWS 60-65F SAT NIGHT. HIGHS SUNDAY RANGE FROM
UPPER 60S NW OF THE IL RIVER TO THE UPPER 70S TO NEAR 80F IN FAR SE
IL BY LAWRENCEVILLE.
LONG TERM...MONDAY THROUGH FRIDAY
QUIET WEATHER EXPECTED MONDAY THROUGH TUESDAY WITH WEAK SURFACE
HIGH PRESSURE RIDGE BUILDING INTO AREA MONDAY AS UPPER LEVEL TROF
SHIFTS EAST OF IL...AND UPPER LEVEL RIDGE MOVING INTO IL TUE.
DEEPENING LOW PRESSURE BELOW 1000 MB MOVING EAST ACROSS THE
NORTHERN PLAINS TO NEAR NORTHERN LAKE SUPERIOR BY SUNRISE WED TO
SWING A COLD FRONT SE TOWARD NW IL. THIS TO SPREAD CHANCE OF
SHOWERS AND ISOLATED THUNDERSTORMS INTO CENTRAL IL TUE NIGHT AND
INTO CENTRAL AND SE IL WED AND WED NIGHT AS COLD FRONT AND FAIRLY
STRONG UPPER LEVEL TROF MOVES TRHOUGH IL. HIGHS 65 TO 70 MONDAY
CLIMB INTO THE LOWER 70S TUE...UPPER 60S AND LOWER 70S WED
(WARMEST IN SE IL) THEN COOLER INTO THE LOW TO MID 60S THU BEHIND
THE COLD FRONT AND UPPER 50S/LOWER 60S FRI.
07
&&
.AVIATION...
ISSUED 1155 PM CDT THU OCT 11 2012...FOR THE 06Z TAFS
REPORTS HAVE COME IN OF A FEW SPRINKLES REACHING THE GROUND FROM
SOME OF THE RADAR RETURNS THIS EVENING. THE HRRR MODELS IS
INDICATING A COUPLE MORE HOURS ISENTROPIC UPGLIDE AHEAD OF THE
COLD FRONT TO HELP FUEL A FEW MORE SPRINKLES THROUGH 07Z-08Z. NO
MEASURABLE RAIN IS EXPECTED AT ANY OF THE TERMINAL SITES...BUT WE
STILL INCLUDED VCSH FOR AN HOUR OR SO TO COVER THE POTENTIAL FOR
SLIGHTLY WET GROUND SURFACE.
WINDS HAVE BEEN GUSTING TO 16-18KT FROM THE NORTH-NORTHEAST AS THE
COLD FRONT PASSES. PIA IS THE ONLY TERMINAL TO HAVE SWITCHED
AROUND BY 0430Z...WITH BMI SHIFTING AT THIS TIME. WINDS SHOULD
REMAIN IN THE 08-12KT RANGE FROM THE NE FOR THE REST OF THE
NIGHT...THEN INCREASE INTO THE 14-16KT RANGE ON FRIDAY AS MIXING
HEIGHTS CLIMB TO AROUND 3-4K FT. WINDS SHOULD BECOME SOUTHEAST BY
LATE AFTERNOON AND DIMINISHING TO AROUND 8-10KT AHEAD OF THE NEXT
SYSTEM.
ANY PRECIP TOMORROW NIGHT SHOULD HOLD OFF UNTIL AFTER 06Z...BEYOND
THIS TAF PERIOD.
SHIMON
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1155 PM CDT THU OCT 11 2012
.DISCUSSION...
ISSUED 859 PM CDT THU OCT 11 2012
TWO MAIN WEATHER ISSUES ARE ON TAP THIS EVENING. A COLD FRONT
PUSHING ACROSS OUR AREA FROM NW TO SE IS EXPECTED TO BE A DRY
FRONTAL PASSAGE...WITH MID AND HIGH CLOUDS THE PRIMARY RESULT
ALONG WITH A WIND SHIFT FROM SW TO N.
THE OTHER ISSUE CENTERS ON ISENTROPIC LIFT AHEAD OF THE COLD FRONT
ACROSS SOUTHERN ILLINOIS INCLUDING THE SOUTHERN THIRD OF OUR
FORECAST AREA. INSTABILITY PARAMETERS SUPPORTIVE OF THUNDERSTORMS
WILL COME VERY CLOSE TO OUR SOUTHEASTERN COUNTIES...BUT SUFFICIENT
MOISTURE LEVELS APPEAR TO REMAIN SOUTH OF OUR AREA. RADAR RETURNS
WILL SHOW VIRGA ACROSS MOST OF OUR COUNTIES OVERNIGHT...BUT NO
PRECIP IS EXPECTED TO REACH THE GROUND. THEREFORE...WE WILL
CONTINUE WITH A DRY FORECAST THE REST OF THE NIGHT.
LOW TEMPS TONIGHT WILL VARY FROM UPPER 30S IN THE NW TO UPPER 40S
IN THE SE. VARYING CLOUD COVER WILL ALLOW FOR SOME COLDER SPOTS IN
THE EAST...BUT THE OVERALL COVERAGE LOOKS ON TRACK.
UPDATE FORECAST INFO WILL BE AVAILABLE SHORTLY.
SHIMON
&&
.AVIATION...
ISSUED 1155 PM CDT THU OCT 11 2012...FOR THE 06Z TAFS
REPORTS HAVE COME IN OF A FEW SPRINKLES REACHING THE GROUND FROM
SOME OF THE RADAR RETURNS THIS EVENING. THE HRRR MODELS IS
INDICATING A COUPLE MORE HOURS ISENTROPIC UPGLIDE AHEAD OF THE
COLD FRONT TO HELP FUEL A FEW MORE SPRINKLES THROUGH 07Z-08Z. NO
MEASURABLE RAIN IS EXPECTED AT ANY OF THE TERMINAL SITES...BUT WE
STILL INCLUDED VCSH FOR AN HOUR OR SO TO COVER THE POTENTIAL FOR
SLIGHTLY WET GROUND SURFACE.
WINDS HAVE BEEN GUSTING TO 16-18KT FROM THE NORTH-NORTHEAST AS THE COLD
FRONT PASSES. PIA IS THE ONLY TERMINAL TO HAVE SWITCHED AROUND BY
0430Z...WITH BMI SHIFTING AT THIS TIME. WINDS SHOULD REMAIN IN THE
08-12KT RANGE FROM THE NE FOR THE REST OF THE NIGHT...THEN
INCREASE INTO THE 14-16KT RANGE ON FRIDAY AS MIXING HEIGHTS CLIMB
TO AROUND 3-4K FT. WINDS SHOULD BECOME SOUTHEAST BY LATE AFTERNOON
AND DIMINISHING TO AROUND 8-10KT AHEAD OF THE NEXT SYSTEM.
ANY PRECIP TOMORROW NIGHT SHOULD HOLD OFF UNTIL AFTER 06Z...BEYOND
THIS TAF PERIOD.
SHIMON
&&
.PREV DISCUSSION...
ISSUED 304 PM CDT THU OCT 11 2012
MAIN CONCERN THIS PACKAGE INCLUDE TIMING OF PCPN FOR FRI NIGHT
THROUGH SUNDAY...WITH THE BIGGEST CHC OF PCPN BEING LATE SAT INTO
SAT NIGHT. THE OTHER CONCERNS WILL BE TEMPS AHEAD OF THIS WEEKEND
SYSTEM ALONG WITH ANOTHER CHC FOR PCPN TUE NIGHT THROUGH WED NIGHT
IN THE EXTENDED.
MODELS LOOK IN FAIRLY GOOD AGREEMENT WITH OVERALL UPPER LEVEL
PATTERN THROUGH THE PERIOD AND LOOK PRETTY SIMILAR WITH THE SFC
FEATURES IN THE SHORT TERM. HOWEVER...THE ECMWF AND GFS MODELS
DIFFER IN THE EXTENDED WITH HOW DEEP THE TROUGH WILL BE MIDDLE OF
THE WEEK AND THE SFC REFLECTION OF THAT ONCE THE FRONT MOVES
THROUGH ON WEDNESDAY.
SHORT TERM...TONIGHT THROUGH SUNDAY
A COLD FRONT....CURRENTLY LOCATED IN SOUTHERN IA/WI WILL DROP
THROUGH THE CWA THIS EVENING AND COME THROUGH DRY SINCE ALL
MOISTURE IS WELL SOUTH OF THE AREA. BEHIND THIS FRONT WILL BE ONE
MORE DRY DAY TOMORROW WITH BELOW NORMAL TEMPS. THIS HIGH PRSS WILL
QUICKLY MOVE EAST TOMORROW AND TOMORROW NIGHT AND A SOUTHERLY
RETURN FLOW WILL QUICKLY SETUP FOR FRI NIGHT AND BRING PCPN BACK
TO THE NORTHWESTERN PARTS OF THE CWA FOR LATE TOMORROW
NIGHT...AFTER MIDNIGHT. PCPN WILL NOT BE MUCH BUT IT WILL BE THE
START TO A COUPLE OF PERIODS OF SHOWERS AND THUNDERSTORMS OVER THE
AREA FOR THE WEEKEND. ONCE THIS FIRST ROUND OF PCPN MOVES THROUGH
EARLY SAT MORNING...MOST OF CWA SHOULD BE IN THE WARM SECTOR AND
DRY...HOWEVER...THERE IS STILL SOME CHANCES OF PCPN IN THE NORTH
AND NORTHWEST DURING THE DAY ON SATURDAY...AS THESE AREAS WILL BE
CLOSEST TO THE DYNAMICS AND WARM FRONTAL ZONE. THEN OCCASIONAL
THUNDERSTORMS WILL MOVE THROUGH THE CWA BEGINNING SAT EVENING AND
CONTINUE THROUGH THE ENTIRE CWA FOR OVERNIGHT SAT NIGHT. SVR WX
DYNAMICS LOOKS BEST OUT WEST FOR SAT AFTERNOON AND EVENING SO
EXPECTING STORMS TO DEVELOP OUT WEST AND THEN MOVE INTO THE AREA
SAT EVENING AND CONTINUE INTO OVERNIGHT SAT NIGHT. SVR WX WILL
CONTINUE TO BE POSSIBLE DURING THE STORMS MOVING THROUGH AND
POSSIBLE THAT STORMS WILL DEVELOP INTO A SQUALL LINE WITH DAMAGING
WINDS BEING MAIN SVR WX THREAT. ONCE THE MAIN EVENT MOVES THROUGH
THE COLD FRONT WILL STILL BE WEST OF THE AREA AND THEN MOVE
THROUGH THE CWA DURING THE DAY ON SATURDAY. HOWEVER...WILL ONLY BE
HOLDING ONTO A CHC OF PCPN SUNDAY IN THE EAST SINCE MOST OF THE
PCPN WILL BE WITH THE STORMS FROM OVERNIGHT.
TEMPS WILL START BELOW NORMAL TOMORROW BUT THEN WARM TO WELL ABOVE
NORMAL AHEAD OF THE FRONT COMING FOR SAT NIGHT/SUNDAY. TEMPS
SUNDAY SHOULD STILL BE AROUND NORMAL. BLEND OF GUIDANCE LOOKS TO BE
BEST FORECAST FOR TEMPS.
LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
PATTERN WILL THEN SHIFT TO MORE OF A ZONAL FLOW FOR MOST OF THE
EXTENDED PERIOD. MODELS HAVE ANOTHER TROUGH AND FRONTAL SYSTEM
MOVING THROUGH THE AREA DURING THE MIDDLE OF THE WEEK. THIS SYSTEM
WILL MOVE THROUGH QUICKLY AND BRING ANOTHER CHC OF THUNDERSTORMS
TO THE REGION FOR TUE NIGHT THROUGH WED NIGHT.
TEMPS WILL BE AROUND NORMAL THROUGH THE PERIOD EXCEPT AFTER THE
MIDWEEK FRONT...WHEN TEMPS WILL THEN FALL TO JUST BELOW NORMAL.
AUTEN
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
244 PM MDT FRI OCT 12 2012
.SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY)
ISSUED AT 1245 PM MDT FRI OCT 12 2012
LATEST THINKING IS THERE WILL BE TWO POTENTIAL ROUNDS OF
PRECIPITATION ASSOCIATED WITH THE LARGE UPPER LOW OVER SOUTHERN
NEVADA THAT WILL AFFECT THE REGION IN THE NEXT 18 HOURS. FIRST...A
SHORT WAVE TROUGH CURRENTLY LIFTING NORTHEAST ACROSS THE OKLAHOMA
PANHANDLE WILL INITIATE SHOWERS AND ISOLATED THUNDERSTORMS THIS
AFTERNOON FROM SOUTHWEST TO NORTHEAST BETWEEN ABOUT 20Z AND 01Z.
THE NAM SHOWS DECENT ELEVATED CAPE AROUND 1000 J/KG HOWEVER 0-6 KM
BULK SHEAR IS ONLY ABOUT 25 KTS THIS AFTERNOON. SUB-SEVERE HAIL
AND C-G LIGHTNING ARE THOUGHT TO BE THE MAIN THREATS. THIS FIRST
ROUND OF PRECIP SHOULD BEGIN TO WEAK AND LOSE COVERAGE AS THE
UPPER TROUGH LIFTS FURTHER NORTHEAST AFTER 00Z. ONE MODULATING
INFLUENCE THIS AFTERNOON IS POSITION OF 250 MB JET. THE CURRENT
LOCATION PUTS OUR AREA IN THE RIGHT EXIT REGION WHICH MAY EXPLAIN
THE LOOK OF THE HRRR REFLECTIVITY FIELDS LATER THIS AFTERNOON
WITH PRECIPITATION SPLITTING AND WEAKENING.
THE BULK OF THE SYSTEM IS EXPECTED TO APPROACH THE AREA OVERNIGHT...
BUT THINK BETTER CHANCES OF SHOWERS AND THUNDERSTORMS WILL BE IN
THE SOUTHEAST COUNTIES IN THE 06-12Z TIME FRAME. THE NAM SHOWS
SOME CAPE IN THE -10 TO -20 C HAIL GROWTH REGION AT THAT TIME,
PLUS 0-6 KM SHEAR WILL INCREASE TO AROUND 70 KTS INDICATING A FEW
STORMS OVERNIGHT HAVE THE POTENTIAL TO PRODUCE SEVERE HAIL IF
THINGS COME TOGETHER AS PLANNED. ALSO KEPT MENTION OF AREAS OF FOG
OVERNIGHT WITH LOW LEVEL RH VALUES ABOVE 95 PERCENT.
ON SATURDAY...SOMEWHAT LESS CERTAIN REGARDING POTENTIAL FOR
SCATTERED SHOWERS DURING THE AFTERNOON. LAPSE RATES NOT ALL THAT
STEEP AS UPPER SYSTEM MOVES OVERHEAD...AND SUBSIDENCE BEHIND UPPER
TROUGH WITH RIDGING MOVING IN WILL COINCIDE WITH PEAK HEATING. KEPT
SLIGHT CHANCES FOR SHOWERS GOING FOR NOW BUT CONFIDENCE IS NOT THAT
HIGH FOR DECENT COVERAGE IF LATEST NAM-GFS VERIFY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 240 PM MDT FRI OCT 12 2012
THE CLOSED LOW THAT BROUGHT PRECIP WILL EXIT THE AREA EARLY SATURDAY
EVENING. MODELS PLACE PRECIP WELL WEST OF THE LOW WHERE A SHORT
WAVE RIDGE WILL BE. AM THINKING IF ANY PRECIP WILL DEVELOP IT
WILL BE JUST BEHIND THE CLOSED LOW. AM NOT TOO CONFIDENT THERE
WILL BE ANY PRECIP ACCOMPANYING THE CLOSED LOW AS IT MOVES EAST
DUE TO 700-500MB LAPSE RATES LESS THAN 6C/KM. HOWEVER WITH MODELS
SHOWING PRECIP FOLLOWING THE CLOSED LOW...WILL KEEP THE MENTION OF
SLIGHT CHANCES GOING DURING THE EARLY EVENING AS THE LOW EXITS THE
AREA.
SUNDAY AND SUNDAY NIGHT AN UPPER LEVEL RIDGE WILL BUILD OVER THE
INTERMOUNTAIN WEST...EXTENDING OVER THE TRI-STATE AREA. A MINOR
SHORT WAVE TROUGH WILL MOVE THROUGH THE FLOW OVER THE NORTHEAST PART
OF THE AREA. HOWEVER WITH LITLE MOISTURE TO WORK WITH...AM NOT
EXPECTING ANYTHING MORE THAN A FEW CLOUDS TO DEVELOP. BEHIND THE
SHORT WAVE TROUGH WINDS WILL INCREASE DURING THE AFTERNOON...WITH
GUSTS NEAR 30MPH AS STRONG WINDS ABOVE THE SURFACE MIX DOWN.
TEMPERATURES FOR SATURDAY THROUGH SUNDAY NIGHT WILL BE NEAR NORMAL.
FOR MONDAY THROUGH FRIDAY THE PERIOD WILL BE PRIMARILY DRY. TUESDAY
AND WEDNESDAY A SHORT WAVE TROUGH MOVES THROUGH THE FLOW OVER THE
AREA...WITH A COLD FRONT FOLLOWING THE FIRST SHORT WAVE TUESDAY
NIGHT. THERE IS SOME MOISTURE TO WORK WITH...SO HAVE INCLUDED
SLIGHT CHANCES FOR THE FAR NORTHEAST PART OF THE AREA TUESDAY
NIGHT. ANOTHER STRONGER COLD FRONT MOVES THROUGH WEDNESDAY NIGHT.
THERE IS LESS MODEL AGREEMENT WITH PRECIP DEVELOPING AS THE SECOND
COLD FRONT MOVES THROUGH...SO WILL CONTINUE WITH THE DRY FORECAST.
TEMPERATURES THROUGH THIS PERIOD WILL BE ABOVE NORMAL PRIOR TO THE
FIRST COLD FRONT THEN NEAR NORMAL THROUGH THE REST OF THE WEEK
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY MORNING) ISSUED
AT 1245 AM MDT FRI OCT 12 2012
MVFR CIGS EXPECTED TO CONTINUE THIS AFTERNOON AND OVERNIGHT WITH A
BRIEF PERIOD TO VFR POSSIBLE LATER THIS AFTERNOON IF LOWER DECK
SCATTERS OUT. IFR CEILINGS WILL REDEVELOP OVERNIGHT BEFORE DRIER
AIR SWEEPS IN THE FROM THE WEST AROUND 12Z. KEPT VCTS IN FOR KGLD
FROM 20Z-00Z BUT FEEL MOST PRECIPITATION WILL BE -SHRA. FOR NOW
KEPT MENTION OF PRECIPITATION OUT OF KMCK TAF WITH BETTER CHANCES
TO SOUTH.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DLF
LONG TERM...JTL
AVIATION...DLF
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1248 PM MDT FRI OCT 12 2012
.SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY)
ISSUED AT 1245 PM MDT FRI OCT 12 2012
LATEST THINKING IS THERE WILL BE TWO POTENTIAL ROUNDS OF
PRECIPITATION ASSOCIATED WITH THE LARGE UPPER LOW OVER SOUTHERN
NEVADA THAT WILL AFFECT THE REGION IN THE NEXT 18 HOURS. FIRST...A
SHORT WAVE TROUGH CURRENTLY LIFTING NORTHEAST ACROSS THE OKLAHOMA
PANHANDLE WILL INITIATE SHOWERS AND ISOLATED THUNDERSTORMS THIS
AFTERNOON FROM SOUTHWEST TO NORTHEAST BETWEEN ABOUT 20Z AND 01Z.
THE NAM SHOWS DECENT ELEVATED CAPE AROUND 1000 J/KG HOWEVER 0-6 KM
BULK SHEAR IS ONLY ABOUT 25 KTS THIS AFTERNOON. SUB-SEVERE HAIL
AND C-G LIGHTNING ARE THOUGHT TO BE THE MAIN THREATS. THIS FIRST
ROUND OF PRECIP SHOULD BEGIN TO WEAK AND LOSE COVERAGE AS THE
UPPER TROUGH LIFTS FURTHER NORTHEAST AFTER 00Z. ONE MODULATING
INFLUENCE THIS AFTERNOON IS POSITION OF 250 MB JET. THE CURRENT
LOCATION PUTS OUR AREA IN THE RIGHT EXIT REGION WHICH MAY EXPLAIN
THE LOOK OF THE HRRR REFLECTIVITY FIELDS LATER THIS AFTERNOON
WITH PRECIPITATION SPLITTING AND WEAKENING.
THE BULK OF THE SYSTEM IS EXPECTED TO APPROACH THE AREA OVERNIGHT...
BUT THINK BETTER CHANCES OF SHOWERS AND THUNDERSTORMS WILL BE IN
THE SOUTHEAST COUNTIES IN THE 06-12Z TIME FRAME. THE NAM SHOWS
SOME CAPE IN THE -10 TO -20 C HAIL GROWTH REGION AT THAT TIME,
PLUS 0-6 KM SHEAR WILL INCREASE TO AROUND 70 KTS INDICATING A FEW
STORMS OVERNIGHT HAVE THE POTENTIAL TO PRODUCE SEVERE HAIL IF
THINGS COME TOGETHER AS PLANNED. ALSO KEPT MENTION OF AREAS OF FOG
OVERNIGHT WITH LOW LEVEL RH VALUES ABOVE 95 PERCENT.
ON SATURDAY...SOMEWHAT LESS CERTAIN REGARDING POTENTIAL FOR
SCATTERED SHOWERS DURING THE AFTERNOON. LAPSE RATES NOT ALL THAT
STEEP AS UPPER SYSTEM MOVES OVERHEAD...AND SUBSIDENCE BEHIND UPPER
TROUGH WITH RIDGING MOVING IN WILL COINCIDE WITH PEAK HEATING. KEPT
SLIGHT CHANCES FOR SHOWERS GOING FOR NOW BUT CONFIDENCE IS NOT THAT
HIGH FOR DECENT COVERAGE IF LATEST NAM-GFS VERIFY.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 305 AM MDT FRI OCT 12 2012
NORTHWEST FLOW WILL BEGIN TO FLATTEN OUT OVER THE WESTERN HALF OF
THE COUNTRY AS A SHORTWAVE TROUGH CONTINUES TO MOVE EASTWARD THROUGH
THE OHIO RIVER VALLEY. LEE TROUGH WILL DEEPEN AHEAD OF A SHORTWAVE
TROUGH THAT WILL BEGIN TO DIG INTO THE ROCKIES BY LATE TUESDAY. THE
ASSOCIATED COLD FRONT WILL MOVE ACROSS THE AREA TUESDAY AND GIVEN A
STRONG 250 MB JET STREAK NOSING INTO THE NORTHERN CENTRAL
PLAINS...MAY HAVE A FEW SCATTERED SHOWERS ACROSS THE NORTH. GIVEN
THE UNCERTAINTY AND TIMING OF THIS SYSTEM...HAVE KEPT AREA DRY FOR
NOW. NORTHWEST FLOW RETURNS OVER THE AREA AND WILL HELP KEEP
TEMPERATURES MILD AND DRY THROUGH THE REMAINDER OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY MORNING) ISSUED
AT 1245 AM MDT FRI OCT 12 2012
MVFR CIGS EXPECTED TO CONTINUE THIS AFTERNOON AND OVERNIGHT WITH A
BRIEF PERIOD TO VFR POSSIBLE LATER THIS AFTERNOON IF LOWER DECK
SCATTERS OUT. IFR CEILINGS WILL REDEVELOP OVERNIGHT BEFORE DRIER
AIR SWEEPS IN THE FROM THE WEST AROUND 12Z. KEPT VCTS IN FOR KGLD
FROM 20Z-00Z BUT FEEL MOST PRECIPITATION WILL BE -SHRA. FOR NOW
KEPT MENTION OF PRECIPITATION OUT OF KMCK TAF WITH BETTER CHANCES
TO SOUTH.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DLF
LONG TERM...PMM
AVIATION...DLF
AREA FORECAST DISCUSSION
NWS PADUCAH KY
935 PM CDT SAT OCT 13 2012
.UPDATE...
ISSUED AT 935 PM CDT SAT OCT 13 2012
UPDATED FORECAST TO RAISE POPS TO CATEGORICAL IN PARTS OF SE
MISSOURI AND SW ILLINOIS LATE TONIGHT. RUC MODEL INDICATES THAT
WIDESPREAD RAIN AND STORMS IN THE WARM CONVEYOR BELT OVER
NORTHERN/WESTERN MISSOURI WILL OVERSPREAD SE MISSOURI AND SW
ILLINOIS AFTER 06Z. THE AXIS OF THE LOW LEVEL JET WILL BE ORIENTED
ALONG OR JUST WEST OF THE MISSISSIPPI RIVER BY 12Z...WITH 50 TO 60
KNOTS IN THE 850/900 MB LAYER. THOUGH INSTABILITY WILL BE MARGINAL
AND ELEVATED...A FEW DAMAGING WIND GUSTS ARE POSSIBLE GIVEN THE WIND
FIELDS ALOFT AND STRONG FORCING FOR CONVECTION.
ADDED MENTION OF GRADIENT WIND GUSTS FROM 30 TO 40 MPH TO THE HWO.
BUFKIT ANALYSIS FROM BOTH GFS/NAM INDICATES SUFFICIENT MIXING ON
SUNDAY TO GET SOME SURFACE GUSTS TO NEAR 40 MPH. DEGREE OF CLEARING
IN THE WAKE OF THE MORNING CONVECTION WILL PLAY A LARGE ROLE IN WIND
GUST POTENTIAL...AS WELL AS POTENTIAL FOR AFTERNOON STORMS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 310 PM CDT SAT OCT 13 2012
DID NOT MAKE ANY DRASTIC CHANGES TO THE GOING FORECAST. ECMWF AND
GEM ARE BOTH A BIT FASTER WITH THE ONSET OF PRECIP THAN THE GFS
AND NAM...BRINGING SHOWERS AND THUNDERSTORMS INTO OUR FAR WESTERN
COUNTIES BY 06Z SUNDAY. OVERALL...THE TIMING DIFFERENCES ARE
MINOR...AND WENT WITH LIKELY POPS FOR THE WESTERN HALF OF THE PAH
FORECAST AREA BY 12Z SUNDAY. THE BEST CHANCES FOR THE WESTERN HALF
OF THE FA WILL BE THROUGH THE MORNING INTO THE EARLY
AFTERNOON...AND THE EASTERN HALF FROM MID MORNING THROUGH MID
AFTERNOON. ALL OF OUR COUNTIES HAVE AT LEAST A FEW HOURS OF LIKELY
POPS.
ECMWF AND GFS SHOW LI`S OF -1 TO -3...AND CAPE VALUES OF
700 TO 1100 J/KG...MAINLY FROM 12Z TO 18Z SUNDAY. NAM CONTINUES
SOME IMPRESSIVE LI AND CAPE VALUES /-3 TO -5 AND 1000 TO 1300
J/KG/ INTO THE AFTERNOON HOURS...WHEN ECMWF AND GFS HAVE ALREADY
PUSHED BEST LIFT/INSTABILITY EAST OF OUR COUNTIES. BASED ON THE
FRONT/UPPER TROF STILL IN WESTERN PORTIONS OF THE FA BY MID
AFTERNOON AND SPC DAY 2 SLIGHT RISK FOR ALL BUT FAR WESTERN
PORTIONS OF OUR FA...NAM LOOKS LIKE A BETTER BET...SO SHOULD SEE
SOME DECENT ACTIVITY THROUGH THE DAY...WITH SOME POTENTIAL FOR
SEVERE STORMS.
THE OTHER ISSUE FOR SUNDAY IS WINDS. MODELS SHOW A VERY TIGHT
PRESSURE GRADIENT TONIGHT AND ESPECIALLY SUNDAY ALONG AND AHEAD OF
THE FRONT. SOUTH TO SOUTHWEST WINDS WILL PICK BACK UP TO 10 TO 15
KTS LATE TONIGHT...THEN INCREASE TO 15 TO 25 KTS WITH GUSTS OF 30
TO 35 KTS FROM 12Z TO 22Z. THIS KEEPS US BELOW WIND ADVISORY
CRITERIA...BUT WILL CONTINUE WITH AN SPS TO HEIGHTEN AWARENESS.
BEYOND SUNDAY...HIGH PRESSURE WILL BUILD INTO THE CENTRAL U.S. FOR
SUNDAY NIGHT THROUGH MONDAY NIGHT. AFTER ABOVE NORMAL TEMPERATURES
ON SUNDAY...NORTHWEST WINDS BEHIND THE FRONT WILL BRING
TEMPERATURES BACK TO NEAR TO EVEN SLIGHTLY BELOW NORMAL TEMPS.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 310 PM CDT SAT OCT 13 2012
THE BIG EVENT OF THE LONG TERM IS THE MID WEEK SYSTEM SO WE WILL
FOCUS ON THAT HERE. POSITIVE MODEL INDICATIONS ARE THAT BOTH THE
EURO AND THE GFS ARE SYNCHRONIZING THE INTRODUCTORY PCPN TIMING AS
THE FRONT APPROACHES THE DOORSTEP OF THE FA BY 00Z THU. IT WILL
ENCOUNTER MINOR INSTABILITY...MAINLY ELEVATED...AS BOTH MODELS AGREE
THE BEST CHANCE OF PCPN COMES WITH/POST FROPA OVERNIGHT WED NIGHT.
WE LIKE THE ALLBLENDS LIKELY CAT POPS AS A STARTING POINT AND COULD
BE GOING UP FROM THERE...BUT WITH LATE DAY 5 WE`LL SEE HOW COLLAB
PLAYS OUT ON THAT.
MODEL DIFFERENCES START WITH THE DEPARTURE OF THE SYSTEM ON
THURSDAY. THE EURO IS MORE AMPLIFIED AND CUTS OFF/DEEPENS THE
LOW...OCCLUDING THE FRONT/LINGERING THE POPS. THE GFS LIKEWISE HAS A
ROBUST/DEEPENING OF THE LOW BUT IS MORE PROGRESSIVE WITH IT ACTUALLY
PASSING AND SWEEPING EASTWARD TO THE EAST COAST. THE ALLBLENDS TENDS
BETWEEN THE TWO WITH LEAN TOWARD THE GFS AND WE THINK THAT IS
REASONABLE UNLESS/UNTIL MORE SUPPORT IS YIELDED TOWARD THE EURO.
TEMPS...70S/50S LOOK REASONABLE AHEAD OF THE FRONT...WITH 60S/40S
AFTER ITS PASSAGE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 627 PM CDT SAT OCT 13 2012
VFR CONDITIONS EXPECTED AT KCGI/KPAH THROUGH 10Z...MVFR CIGS/VSBYS
AND TSRA THROUGH 16Z...THEN VFR AGAIN. AT KEVV/KOWB VFR CONDITIONS
EXPECTED THROUGH 13Z...MVFR CIGS/VSBYS AND TSRA THROUGH 22Z...THEN
VFR. SOUTHERLY WINDS AROUND 10 KTS WILL PICK UP OUT OF THE SOUTH
SOUTHWEST AFT 10Z AT 15-18 KTS WITH GUSTS TO 25-28 KTS.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...MY
AVIATION...JP
SHORT/LONG TERM...RST/DH
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1229 AM EDT FRI OCT 12 2012
.UPDATE...
ISSUED AT 1230 AM EDT FRI OCT 12 2012
BASIC CLEAR SKIES AND LIGHT WINDS. MAIN CONSIDERATION FOR THIS UPDATE
IS THE TEMPERATURES AND POSSIBILITY OF FOG/FROST. MINOR TWEAKS TO THE
GRIDS TO ALIGN WITH CURRENT OBS BUT NO CHANGES TO ZONE FORECAST.
UPDATE ISSUED AT 915 PM EDT THU OCT 11 2012
UPDATED FORECAST TO REMOVE THUNDER CHANCES. MODELS ARE REALLY LACKING
ANY INSTABILITY TONIGHT. THUS...DO NOT SEE ANY SUPPORT FOR THUNDER.
AS FAR AS THE FROST POTENTIAL...COOP MOS GUIDANCE HAS THE COLDEST
OVERNIGHT LOW AT 36 WHICH IS PROBABLY THE ABSOLUTE MINIMUM
TEMPERATURES COULD REACH TONIGHT GIVEN THE INCREASING CLOUD COVER
LATE. THUS...GOING TO REMOVE THE MENTION OF FROST. AS FAR AS
PRECIPITATION CHANCES...THE RUC AND HRRR ARE BOTH INDICATING
SCATTERED SHOWERS SPREADING INTO OUR SOUTHWEST TOWARDS DAWN.
THUS...PLAN TO BRING THE CHANCE OF RAIN UP TO BETWEEN 30 AND 40
PERCENT. IT LOOKS LIKE THE THREAT FOR RAIN WILL BE SHORT LIVED AND
WILL BE ON THE WAY OUT BY MID MORNING. THE ZFP...HWO AND NDFD HAVE
ALREADY BEEN UPDATED.
UPDATE ISSUED AT 729 PM EDT THU OCT 11 2012
STILL A BIT OF UNCERTAINTY WITH EXACTLY HOW MUCH AREAL COVERAGE THERE
WILL BE TONIGHT. LATEST HRRR (20Z) SHOWS A BIT MORE PRECIPITATION
COMING ACROSS OUR SOUTHWEST ZONES AFTER 08Z. HOWEVER...PREVIOUS RUNS
HAD ALMOST NOTHING. IT WILL BE INTERESTING TO SEE IF THE NEW RUN OF
THE HRRR TAKES HOLD OR IF IT BACKS OFF WITH THE NEXT RUN.
REGARDLESS...GOING TO BE WATCHING THINGS UPSTREAM AS CONVECTION IS
EXPECTED TO DEVELOP ACROSS SOUTHERN MISSOURI AND WESTERN
KENTUCKY...THEN SPREAD INTO THE AREA LATE. IF THE CONVECTION DOES NOT
MATERIALIZE...THIS WOULD OBVIOUSLY LEND ITSELF TO A DRIER FORECAST.
ITS GOING TO BE A WAITING GAME OVER THE NEXT 3 TO 5 HOURS. BASED ON
THE LACK OF SIGNIFICANT FORCING AND PRESENT ACTIVITY UPSTREAM...MY
GUT FEELING IS THAT WE WILL PROBABLY END UP ON THE DRIER SIDE OF
THINGS. HOWEVER...PLAN TO WAIT THINGS OUT AND PERHAPS SEE WHAT SOME
OF THE NEW 00Z MODELS COME IN WITH. FOR NOW...MADE SIGNIFICANT HOURLY
TWEAKS TO TEMPERATURES AND DEWPOINTS TO REPRESENT THE QUICKLY FALLING
VALLEY TEMPS THIS EVENING. PLAN TO REWORK TEMPERATURES FURTHER TO
SHOW MORE STEADY OR SLOWLY FALLING TEMPS IN THE SOUTHWEST WITH THE
INCREASING CLOUD COVER. GRIDS HAVE BEEN SAVED AND SENT TO NDFD.
&&
.SHORT TERM...(TONIGHT THROUGH FRIDAY NIGHT)
ISSUED AT 322 PM EDT THU OCT 11 2012
A WARM FRONT WILL APPROACH FROM THE SOUTHWEST WHILE A WEAKENING COLD
FRONT ENTERS THE REGION FROM THE NORTHWEST LATE TONIGHT. ELEVATED
WARM AIR ADVECTION NORTH OF THE WARM FRONT IS FORECAST TO PRODUCE A
SATURATED WARM LAYER AROUND 800-850 MB OVER OUR SW COUNTIES LATE
TONIGHT AND FRIDAY MORNING...RESULTING IN INCREASING CLOUDS. FORECAST
SOUNDINGS SHOW A CONVECTIVE CAP OVER TOP OF THIS LAYER ACROSS MOST OF
THE FORECAST AREA. HOWEVER...THERE IS ONLY A THIN CAP AROUND 650 MB
AT 12Z FRIDAY IN OUR FAR SW...AND WILL CONTINUE TO USE 20 PERCENT
POPS FOR TSRA THERE LATE TONIGHT AND EARLY FRIDAY.
DRIER AIR WILL WORK IN FROM THE NORTH BEHIND THE DECAYING COLD FRONT
DURING THE DAY FRIDAY AND BRING A RETURN TO CLEAR SKIES FOR MOST OF
FRIDAY NIGHT...AS SURFACE HIGH PRESSURE CONTROLLING OUR WEATHER
PASSES BY TO OUR NE.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 322 PM EDT THU OCT 11 2012
AN ACTIVE AND SOMEWHAT PROGRESSIVE PATTERN LOOKS TO BE IN PLACE FOR
THE EXTENDED PERIOD. THE UPPER LEVEL PATTERN THROUGH THE EARLY PART
OF THE EXTENDED IS HIGHLIGHTED BY A BROAD TROUGH OVER THE UPPER
GREAT LAKES WITH SUCCESSIVE SHORTWAVES MOVING THROUGH THE NORTHERN
PLAINS AND INTO THE GREATER LAKES. BY SUNDAY...THE BROAD TROUGH OVER
THE GREAT LAKES FINALLY SHIFTS EAST INTO THE ATLANTIC AS THE NEXT
WAVE MOVES THROUGH THE PLAINS INTO THE UPPER MS VALLEY. RECENT RUNS
OF THIS WAVE HAVE SHOWN A GENERAL INCREASE IN STRENGTH AS THE RECENT
RUN OF THE GFS SHOWS A NEGATIVELY TILTED TROUGH MOVING INTO THE OHIO
VALLEY SUNDAY EVENING. GIVEN THE FLOW...WILL WAIT FOR SOME LATER
RUNS TO GAUGE THE LEVEL OF CONVECTION AS RIGHT NOW...INSTABILITY
LOOKS TO BE IN QUESTION. 12Z RUNS ALONG WITH THE ALL BLEND ARE
COMING IN WITH A BIT OF INSTABILITY SO WILL THROW IN CHANCE THUNDER
FOR SUNDAY.
BY MONDAY NIGHT...HIGH PRESSURE FILTERS IN BEHIND THE FRONT WITH
ANOTHER EARLY FALL LIKE AIR MASS POISED TO ADVECT IN. HOWEVER...THE
PATTERN SUGGESTS THE FRONT TO SLOW OVER THE APPALACHIAN CHAIN FOR
MONDAY NIGHT AND INTO TUESDAY. THIS COULD SLOW THE IMPACT OF THE AIR
MASS BEHIND THE FRONT AND KEEP TEMPS FROM BOTTOMING OUT AT THE
SURFACE. WILL ADDRESS THESE FORECAST PROBLEMS BASED ON THE ALL
MODELS BLEND SOLUTION. ALSO WILL KEEP CLOUD COVER LINGERING IN THE
EASTERN RANGES THROUGH MONDAY NIGHT AS THE FRONT WILL LIKELY HANG UP
ALONG THE APPALACHIAN RANGE.
HIGH PRESSURE WILL SETTLE FINALLY BY TUESDAY BEFORE THE NEXT WAVE
BEGINS TO IMPACT THE AREA LATE WEDNESDAY. THE SOMEWHAT PROGRESSIVE
PATTERN IN THE EXTENDED AND LACK OF AMPLITUDE WILL LEAD TO MORE
SEASONAL LOWS FOR EASTERN KENTUCKY IN THE MID TO UPPER 40S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1230 AM EDT FRI OCT 12 2012
VFR CONDITIONS WILL CONTINUE OVER THE NEXT 24 HOURS. THE ONLY CHANCE
TO TEMPORARILY GO TO MVFR WILL BE AROUND DAYBREAK...AS CIGS LOWER TO
AROUND 3.5K FT WITH VCSH NEAR LOZ/SME/EKQ/1A6. THE CIGS COULD
TEMPORARILY DROP TO 3KFT OR SLIGHTLY LOWER...BUT TOO MUCH UNCERTAINTY
TO GO THAT LOW AT THIS TIME. OTHERWISE...CIG HEIGHTS WILL AGAIN BE ON
THE INCREASE TOMORROW BEFORE SKIES CLEAR FROM THE NORTH IN THE
AFTERNOON AND EVENING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DUSTY
SHORT TERM...HAL
LONG TERM...SHALLENBERGER
AVIATION...DUSTY
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1027 PM EDT SAT OCT 13 2012
.SYNOPSIS...
HIGH PRESSURE DEPARTS TO THE EAST TONIGHT AS A WARM FRONT CROSSES
THE OHIO VALLEY. A FEW SHOWERS ALONG THE WARM FRONT COULD REACH THE
COUNTIES TO THE NORTH LATE. OTHERWISE...TEMPERATURES WILL WARM
THROUGH SUNDAY BEFORE A COLD FRONT BRINGS INCREASING CHANCES FOR
SHOWERS AND COOLER TEMPERATURES...SUNDAY AFTERNOON AND MONDAY.
&&
.NEAR TERM /THROUGH SUNDAY/...
HAVE MADE MINOR ADJUSTMENTS TO OVERNIGHT POPS. LATEST DATA SHOWS
MOST OF THE RAIN TO THE WEST DECAYING AS IT MOVES EASTWARD INTO
THE DRIER ATMOSPHERE. HOWEVER, THE MAIN SHORTWAVE WILL MOVE ACROSS
THE NORTH THIS EVENING, WHICH WILL LIKELY PROVIDE ENOUGH DYNAMICS
TO SUSTAIN THE RAINFALL.
HIGH PRESSURE RIDGE WILL CONTINUE TO SHIFT EASTWARD AS A WARM
FRONT CROSSES THE OHIO VALLEY. A SHORTWAVE RIDING ALONG THE WARM
FRONT HAS ENHANCED SHOWER ACTIVITY FURTHER TO THE WEST OVER
ILLINOIS AND INDIANA TODAY. THIS SHOULD CONTINUE TO SHIFT TO THE
NORTH WITH THE BUILDING RIDGE KEEPING THE BULK OF THE SHOWERS
MAINLY NORTH OF I-80. AT THIS POINT...KEPT HIGH CHANCE POPS FOR
THOSE COUNTIES AND ONLY A SLIGHT CHANCE FURTHER SOUTH AND INTO
OHIO AS THE FRONT LIFTS NORTHWARD. STRONG WARM ADVECTION AND
CLOUD COVER WITH APPROACHING LOW WILL KEEP OVERNIGHT TEMPERATURES
ELEVATED AND ABOUT 20 DEGREES WARMER THAN LAST NIGHT.
THE FIRST HALF OF SUNDAY SHOULD REMAIN DRY...AS THE WARM FRONT
MOVES INTO NEW YORK AND THE UPPER LEVEL TROUGH AND SURFACE LOW
MOVES INTO MICHIGAN. DESPITE CLOUD COVER...STRONG WARM ADVECTION
WILL CONTINUE AND WITH TEMPERATURES STARTING OUT WARM IN THE
MORNING...THINK IT`S REASONABLE MOST PLACES WILL REACH
TEMPERATURES INTO THE 70S.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
THE LATEST RUNS OF THE DETERMINISTIC MODELS HAVE PUSHED BACK THE
TIMING OF THE FRONT BY A FEW HOURS. SO...LIKELY POPS WERE BROUGHT
INTO THE WESTERN ZONES LATE SUNDAY EVENING. AS THE UPPER LEVEL
SHORTWAVE DIGS THROUGH THE TROUGH AND THE SYSTEM BECOMES
NEGATIVELY TILTED...THE SOUTHERN EDGE OF A STRONG LOW-MID LEVEL
JET WILL SETUP OVER OHIO. WHILE THE 12Z NAM SUGGESTS A BIT MORE
INSTABILITY THAN PREVIOUS RUNS...MAINLY OVER OHIO...THE LATE
TIMING OF THE FRONT COULD HAVE AN IMPACT ON WHETHER ANY STRONG
STORMS DEVELOP. IN ADDITION...STRONG WARM ADVECTION IN LOW LEVELS
COULD KEEP THE REGION CAPPED...DECREASING THE WIND/SEVERE THREAT
AS STRONGER WINDS WONT BE TRANSLATED TO THE SURFACE. HAVE
INTRODUCED AT LEAST A SLIGHT CHANCE MENTION OF THUNDER INTO MOST
OF OUR OHIO COUNTIES WITH DECENT DYNAMICS PRESENT. REGARDLESS...WITH
THE STRENGTH OF THE FRONT...WINDS SHOULD BE GUSTY SUNDAY EVENING
AND MONDAY WITH THE FRONTAL PASSAGE. THE FRONT IS PROGGED TO BE
EAST OF THE RIDGES BY MONDAY AFTERNOON. NORTHWEST FLOW BEHIND THE SYSTEM
SHOULD KEEP CLOUD COVER AND A SLIGHT CHANCE OF SHOWERS THROUGH THE
REMAINDER OF THE DAY AND INTO MONDAY NIGHT PER THE MOST RECENT
BUFKIT PROFILES AND 850HPA TEMPERATURE DROPPING TO 0C.
WINDS WILL BEGIN TO BACK AS A RIDGE OF HIGH PRESSURE BUILDS EAST
TUESDAY. WITH INVERSION LEVELS SHRINKING AND A LESS THAN OPTIMAL
WIND DIRECTION...ENDED PRECIP CHANCES BY TUESDAY MORNING.
TEMPERATURES WERE KEPT A FEW DEGREES BELOW NORMAL BOTH MONDAY AND
TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A DRY FORECAST UNDER A DOME OF HIGH PRESSURE TUESDAY NIGHT INTO
WEDNESDAY. BY LATE WEDNESDAY HIGH PRESSURE WILL SHIFT EAST AND A
COLD FRONT WILL APPROACH WEDNESDAY NIGHT INTO THURSDAY BRINGING A
CHANCE OF SHOWERS AND PERHAPS A THUNDERSTORM. TEMPERATURES WILL WARM
ABOVE NORMAL THROUGH MID WEEK. LATER PERIODS OF THE FORECAST CONTAIN
MUCH UNCERTAINTY AS MODELS DIFFER ON TIMING AND STRENGTH OF CLOSED
LOW FORMING ACROSS THE CENTRAL STATES AND GRADUALLY MOVING EAST.
THIS WILL KEEP SHOWER CHANCES IN THE FORECAST INTO THE WEEKEND.
EXPECT QUITE A FEW CHANGES TO FRIDAY AND SATURDAY FORECASTS WITH
FUTURE FORECAST PACKAGES. FOR NOW STAYED CLOSE TO HPC GRIDS WITH
ONLY A FEW MODIFICATIONS.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
BLEND OF RECENT RADAR DAT AND HRRR MODEL OUTPUT SHOW SLOW NORTHBOUND
WARM FRONT PROVIDING SHOWERS...MAINLY NORTH OF OF KPIT. SO EXPECT
VFR STRATOCUMULUS AND ALTOCUMULUS TO CONTINUE INTO AT LEAST LATE
SUNDAY AFTERNOON OR EARLY EVENING...WITH ONLY KFKL HAVING A CHANCE
OF A SHORT PERIOD OF MVFR SHOWERS THROUGH 08Z.
SO THE MAIN AVIATION CONCERN OVERNIGHT WILL BE LOW LEVEL WIND
SHEAR... WHICH HAS BEEN INSERTED INTO THE TAFS INTO 15Z.
RECENT KPBZ RADAR WIND PROFILES AND NAM MODEL PROFILES SHOW
SOUTHWEST WINDS AT 2 KFT CAN BE 45KTS...WHILE SURFACE DATA SHOWS
SURFACE WINDS WILL CONTINUE TO BE MORE LIKE 5 TO 10 KTS...ALTHOUGH
RECENT SURFACE DATA HAS SHOWN GUSTS TO 20 KTS NEAR THE SHOWERS
NORTH.
AS VERTICAL MIXING INCREASES DAYTIME SUNDAY...NAM MODEL PROFILES
SHOW SURFACE WINDS CAN GUST TO 25 KTS.
AN EASTBOUND COLD FRONT WILL PROMOTE MVFR SHOWERS ACROSS THE UPPER
OHIO VALLEY SUNDAY NIGHT...WITH POSSIBLE IFR THUNDERSTORMS WEST OF
KPIT SUNDAY EVENING. POST FRONTAL VERTICAL MIXING MAY CAUSE WIND
GUSTS TO 30 KTS.
.OUTLOOK.../MONDAY THROUGH WEDNESDAY/...
ENSUING EASTBOUND COLD UPPER TROUGH MAY PROMOTE LINGERING COLD POOL
STRATOCUMULUS AND SCATTERED SHOWERS WITH MVFR RESTRICTIONS MONDAY.
HIGH PRESSURE WILL THEN FOLLOW WITH GENERAL VFR TUESDAY AND
WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
724 PM EDT SAT OCT 13 2012
.SYNOPSIS...
HIGH PRESSURE DEPARTS TO THE EAST TONIGHT AS A WARM FRONT CROSSES
THE OHIO VALLEY. A FEW SHOWERS ALONG THE WARM FRONT COULD REACH THE
COUNTIES TO THE NORTH LATE. OTHERWISE...TEMPERATURES WILL WARM
THROUGH SUNDAY BEFORE A COLD FRONT BRINGS INCREASING CHANCES FOR
SHOWERS AND COOLER TEMPERATURES...SUNDAY AFTERNOON AND MONDAY.
&&
.NEAR TERM /THROUGH SUNDAY/...
HAVE MADE MINOR ADJUSTMENTS TO OVERNIGHT POPS. LATEST DATA SHOWS
MOST OF THE RAIN TO THE WEST DECAYING AS IT MOVES EASTWARD INTO
THE DRIER ATMOSPHERE. HOWEVER, THE MAIN SHORTWAVE WILL MOVE ACROSS
THE NORTH THIS EVENING, WHICH WILL LIKELY PROVIDE ENOUGH DYNAMICS
TO SUSTAIN THE RAINFALL.
HIGH PRESSURE RIDGE WILL CONTINUE TO SHIFT EASTWARD AS A WARM
FRONT CROSSES THE OHIO VALLEY. A SHORTWAVE RIDING ALONG THE WARM
FRONT HAS ENHANCED SHOWER ACTIVITY FURTHER TO THE WEST OVER
ILLINOIS AND INDIANA TODAY. THIS SHOULD CONTINUE TO SHIFT TO THE
NORTH WITH THE BUILDING RIDGE KEEPING THE BULK OF THE SHOWERS
MAINLY NORTH OF I-80. AT THIS POINT...KEPT HIGH CHANCE POPS FOR
THOSE COUNTIES AND ONLY A SLIGHT CHANCE FURTHER SOUTH AND INTO
OHIO AS THE FRONT LIFTS NORTHWARD. STRONG WARM ADVECTION AND
CLOUD COVER WITH APPROACHING LOW WILL KEEP OVERNIGHT TEMPERATURES
ELEVATED AND ABOUT 20 DEGREES WARMER THAN LAST NIGHT.
THE FIRST HALF OF SUNDAY SHOULD REMAIN DRY...AS THE WARM FRONT
MOVES INTO NEW YORK AND THE UPPER LEVEL TROUGH AND SURFACE LOW
MOVES INTO MICHIGAN. DESPITE CLOUD COVER...STRONG WARM ADVECTION
WILL CONTINUE AND WITH TEMPERATURES STARTING OUT WARM IN THE
MORNING...THINK IT`S REASONABLE MOST PLACES WILL REACH
TEMPERATURES INTO THE 70S.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
THE LATEST RUNS OF THE DETERMINISTIC MODELS HAVE PUSHED BACK THE
TIMING OF THE FRONT BY A FEW HOURS. SO...LIKELY POPS WERE BROUGHT
INTO THE WESTERN ZONES LATE SUNDAY EVENING. AS THE UPPER LEVEL
SHORTWAVE DIGS THROUGH THE TROUGH AND THE SYSTEM BECOMES
NEGATIVELY TILTED...THE SOUTHERN EDGE OF A STRONG LOW-MID LEVEL
JET WILL SETUP OVER OHIO. WHILE THE 12Z NAM SUGGESTS A BIT MORE
INSTABILITY THAN PREVIOUS RUNS...MAINLY OVER OHIO...THE LATE
TIMING OF THE FRONT COULD HAVE AN IMPACT ON WHETHER ANY STRONG
STORMS DEVELOP. IN ADDITION...STRONG WARM ADVECTION IN LOW LEVELS
COULD KEEP THE REGION CAPPED...DECREASING THE WIND/SEVERE THREAT
AS STRONGER WINDS WONT BE TRANSLATED TO THE SURFACE. HAVE
INTRODUCED AT LEAST A SLIGHT CHANCE MENTION OF THUNDER INTO MOST
OF OUR OHIO COUNTIES WITH DECENT DYNAMICS PRESENT. REGARDLESS...WITH
THE STRENGTH OF THE FRONT...WINDS SHOULD BE GUSTY SUNDAY EVENING
AND MONDAY WITH THE FRONTAL PASSAGE. THE FRONT IS PROGGED TO BE
EAST OF THE RIDGES BY MONDAY AFTERNOON. NORTHWEST FLOW BEHIND THE SYSTEM
SHOULD KEEP CLOUD COVER AND A SLIGHT CHANCE OF SHOWERS THROUGH THE
REMAINDER OF THE DAY AND INTO MONDAY NIGHT PER THE MOST RECENT
BUFKIT PROFILES AND 850HPA TEMPERATURE DROPPING TO 0C.
WINDS WILL BEGIN TO BACK AS A RIDGE OF HIGH PRESSURE BUILDS EAST
TUESDAY. WITH INVERSION LEVELS SHRINKING AND A LESS THAN OPTIMAL
WIND DIRECTION...ENDED PRECIP CHANCES BY TUESDAY MORNING.
TEMPERATURES WERE KEPT A FEW DEGREES BELOW NORMAL BOTH MONDAY AND
TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A DRY FORECAST UNDER A DOME OF HIGH PRESSURE TUESDAY NIGHT INTO
WEDNESDAY. BY LATE WEDNESDAY HIGH PRESSURE WILL SHIFT EAST AND A
COLD FRONT WILL APPROACH WEDNESDAY NIGHT INTO THURSDAY BRINGING A
CHANCE OF SHOWERS AND PERHAPS A THUNDERSTORM. TEMPERATURES WILL WARM
ABOVE NORMAL THROUGH MID WEEK. LATER PERIODS OF THE FORECAST CONTAIN
MUCH UNCERTAINTY AS MODELS DIFFER ON TIMING AND STRENGTH OF CLOSED
LOW FORMING ACROSS THE CENTRAL STATES AND GRADUALLY MOVING EAST.
THIS WILL KEEP SHOWER CHANCES IN THE FORECAST INTO THE WEEKEND.
EXPECT QUITE A FEW CHANGES TO FRIDAY AND SATURDAY FORECASTS WITH
FUTURE FORECAST PACKAGES. FOR NOW STAYED CLOSE TO HPC GRIDS WITH
ONLY A FEW MODIFICATIONS.
&&
.AVIATION /23Z SATURDAY THROUGH THURSDAY/...
WITH RECENT HRRR MODEL OUTPUT SHOWING NORTHBOUND WARM FRONTAL
SHOWERS AFFECTING AT MOST TAF SITES NORTH OF KPIT...EXPECT VFR TO
CONTINUE INTO AT LEAST LATE SUNDAY AFTERNOON OR EARLY EVENING.
ONLY KFKL HAS A CHANCE OF ENDUING A SHORT PERIOD OF MVFR SHOWERS
THROUGH 04Z.
THE ONLY OTHER AVIATION CONCERN...AS INDICATED BY RECENT NAM MODEL
PROFILES...CAN BE SOUTHWEST WINDS AT 2 KFT REACHING 40KTS LATE
TONIGHT...WHILE SURFACE WINDS WILL BE MORE LIKE 10 KTS. THIS MAY BE
ENOUGH OF A DIFFERENCE TO PROMOTE LOW LEVEL WIND SHEAR...BUT DID NOT
HAVE SUFFICIENT CONFIDENCE TO INCLUDE IN TAFS.
AS VERTICAL MIXING INCREASES DAYTIME SUNDAY...SURFACE WINDS CAN GUST
TO 25 KTS.
.OUTLOOK.../SUNDAY NIGHT THROUGH WEDNESDAY/...
AN EASTBOUND COLD FRONT WILL PROMOTE MVFR SHOWERS AND POSSIBLE IFR
THUNDERSTORMS SUNDAY NIGHT. POST FRONTAL VERTICAL MIXING MAY CAUSE
WIND GUSTS TO 30 KTS WITH MVFR SHOWERS LINGERING INTO MONDAY. HIGH
PRESSURE WILL THEN PROVIDE GENERAL VFR TUESDAY AND WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
705 PM EDT SAT OCT 13 2012
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 423 PM EDT SAT OCT 13 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A ZONALLY ORIENTED FLOW
ACROSS SRN CANADA AND THE FAR NRN CONUS. TO THE S...A SHORTWAVE TROF
IS EMERGING FROM CO/NM INTO THE WRN PLAINS. DEEP/MOIST SW FLOW
DOWNSTREAM OF THE TROF HAS GENERATED SEVERAL AREAS OF SHRA AND SOME
TSRA FROM THE SRN PLAINS TO THE GREAT LAKES. WITH THE MORE ZONALLY
ORIENTED FLOW ACROSS THE FAR NRN CONUS...THE AREAS OF SHRA HAVE BEEN
TENDING TO SHIFT MORE EASTWARD THE FARTHER N THEY SPREAD. AS A
RESULT...THERE HAS BEEN LITTLE PCPN OVER THE NW HALF OF THE FCST
AREA TODAY (MUCH OF THE PCPN HAS BEEN DRIZZLE) WHILE THE SE HALF HAS
BEEN GETTING BRUSHED BY SHRA.
PCPN TRENDS/COVERAGE WILL BE THE MAIN FCST ISSUES IN THE SHORT TERM.
FLOW ACROSS SRN CANADA/FAR NRN CONUS IS EXPECTED TO BUCKLE AS HEIGHT
RISES OVER WRN NAMERICA FORCE DOWNSTREAM HEIGHT FALLS INTO
MISSISSIPPI VALLEY REGION. THIS WILL HELP TO PICK UP/LIFT THE WRN
PLAINS SHORTWAVE TO THE NE. EXACTLY HOW FAR N IT LIFTS WILL BE
IMPORTANT TO THE PCPN FCST TONIGHT/SUN. EVEN AT THIS SHORT TIME
RANGE INTO MODEL RUNS...THERE ARE STILL IMPORTANT DIFFERENCES IN THE
MODELS. THE NAM REMAINS MOST SUPPRESSED WITH THE LOW TRACK THOUGH IT
HAS TRENDED SLIGHTLY N...AND IT IS SUPPORTED BY OUR LOCAL REG WRF
RUN AND THE NCEP HIGH RES WRF-ARW AND WRF-NMN. THEY ALL KEEP THE
MAIN PCPN SHIELD ALMOST ENTIRELY SE OF FCST AREA SUN. THE 12Z GFS
HAS TRENDED S AND ONLY BRINGS PCPN SHIELD INTO THE SE FCST AREA. THE
UKMET/REGIONAL GEM PUSH PCPN SHIELD A LITTLE FARTHER N AND W. THE 12Z
ECMWF HAS ALSO TRENDED SLIGHTLY S. GIVEN OVERALL TRENDS AND A
MAJORITY SHOWING A LESS AGGRESSIVE MOISTURE PUSH INTO UPPER MI
SUN...FCST WILL FOLLOW SUIT AND SHOW HIGHER POPS SHIFTED MORE TO THE
S AND E.
CURRENT PUSH OF SHRA ENE THRU WI INTO SRN UPPER MI IS ASSOCIATED
WITH A SURGE OF 850-700MB MOISTURE TRANSPORT AND ISENTROPIC ASCENT
ON THE 305K SFC. WITH THAT MOISTURE TRANSPORT/ASCENT QUICKLY
SHIFTING E THIS EVENING...AND THEN RATHER MEAGER FORCING LEFT BEHIND
FOR THE NIGHT...IT APPEARS THERE WON`T BE MUCH IN THE WAY OF
RAINFALL FOR THE BULK OF TONIGHT AS WE AWAIT THE MAIN PIECE OF
ENERGY TO TRACK INTO THE GREAT LAKES SUN. WITH WINDS BECOMING LIGHT
UPSLOPE OFF LAKE SUPERIOR DURING THE NIGHT...-DZ THAT HAS BEEN
OCCURRING TODAY WILL LIKELY CONTINUE TONIGHT...ESPECIALLY ACROSS THE
NCNTRL.
SHORTWAVE LIFTS INTO THE GREAT LAKES SUN AFTN WITH ASSOCIATED SFC
LOW TRACKING TOWARD NRN LWR MI. AS A RESULT...RAIN WILL SPREAD BACK
TO THE N...BUT AS DISCUSSED ABOVE...LOWERED POPS FROM PREVIOUS FCST.
KEPT CATEGORICAL POPS ONLY ALONG LAKE MICHIGAN INTO THE FAR ERN FCST
AREA WITH POPS DROPPING OFF SHARPLY TO CHC JUST TO THE NW. MAY SEE A
LITTLE LAKE ENHANCED SHRA ACTIVITY IN THE NNE/NE WIND FAVORED
LOCATIONS...SO SHRA CHANCES IN THOSE AREAS WILL BE A LITTLE HIGHER.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 423 PM EDT SAT OCT 13 2012
A FAIRLY STRONG UPPER SHORTWAVE TROUGH WILL BE OVER THE CENTRAL CWA
AT 00Z MON...DEEPENING AS IT MOVES TO THE FAR ERN CWA BY 06Z MON DUE
TO A WEAK SHORTWAVE PHASING WITH THE SYSTEM. AT THE SFC...A ROUGHLY
995MB LOW WILL BE OVER OVER NRN LOWER MI AT 00Z MON...MOVING TO
GEORGIAN BAY BY 06Z MON. THE 850MB LOW WILL BE JUST E OF DRUMMOND
ISLAND AT 00Z MON...WITH A NICE DEFORMATION PRECIP BAND JUST ON THE
LEFT SIDE OF THE 850MB LOW TRACK AS IT MOVES NE. THERE SHOULD BE A
PRETTY SHARP CUT OFF BETWEEN THE DEFORMATION BAND AND LITTLE TO NO
SYNOPTIC RAIN...AND AFTER 00Z SUN...THE CWA SHOULD BE ON THE DRIER
SIDE OF THAT CUT OFF. HOWEVER...WITH THE SHORTWAVE DEEPENING
OVERHEAD THEN MOVING E...COLDER 850MB TEMPS WILL FILTER IN FROM THE
NNW. WITH THE NNW LOW LEVEL WINDS AND 850MB TEMPS OF -3C TO
-4C...SOME LIGHT LAKE EFFECT RAIN /MIXING WITH SNOW OVER THE HIGHER
TERRAIN/ WILL LINGER INTO MONDAY MORNING OVER NCENTRAL AND ERN UPPER
MI.
A SFC RIDGE WILL MOVE OVER MON AFTERNOON AND EVENING...BRINGING A
BRIEF DRY PERIOD BEFORE A SHORTWAVE TROUGH AND ASSOCIATED WARM FRONT
MOVE INTO THE CWA. PRECIP CHANCES MOVE BACK IN WITH THIS SYSTEM
AFTER MIDNIGHT MON NIGHT...WITH AT LEAST SLIGHT CHANCE POPS OVER
PARTS OF THE CWA UNTIL MORE PRECIP ARRIVES WITH A LOW PRESSURE
SYSTEM MOVING IN FROM THE W ON WED. HIGHS ON MON LOOK TO BE IN THE
UPPER 40S TO MID 50...WITH WARMER TEMPS ON TUE IN THE 50S. WED LOOKS
TO CONTINUE THE WARM TREND WITH HIGHS AGAIN IN THE 50S. OVERALL GOOD
CONFIDENCE INTO WED.
CONFIDENCE DECREASES AS THE NEXT SYSTEM MOVES IN WED INTO THE END OF
NEXT WEEK SINCE MODELS GENERALLY SHOW THE SAME IDEA OF THE LOW
CLOSING OFF ON THU AND LINGERING SOMEWHERE OVER/NEAR THE REGION
THROUGH THE END OF THE WEEK. HOWEVER...MODELS SHOW SIGNIFICANTLY
VARYING SOLUTIONS WITH WHERE TO HAVE THE LOW...WHICH CAUSES WIDELY
DIFFERENT PRECIP/WIND SCENARIOS. EVEN WITH THE DIFFERENCES...WILL
HAVE CHANCES OF PRECIP FOR THE REST OF THE PERIOD LATE WED THROUGH
SAT...DERIVED FROM CONSENSUS OF MODELS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 705 PM EDT SAT OCT 13 2012
LOW PRES OVER THE PLAINS WILL MOVE NORTHEAST TOWARD THE WRN GREAT
LAKES DURING THE FCST PERIOD. ABUNDANT MOISTURE STREAMING N AHEAD OF
SYSTEM HAS RESULTED IN WIDESPREAD MOSTLY IFR CONDITIONS ACROSS WI
INTO UPPER MI. AT KIWD THIS EVENING...EXPECT MVFR CONDITIONS TO
PREVAIL. MAY SEE A PERIOD OF IFR CONDITIONS/-DZ LATER TONIGHT AS NNE
WINDS STRENGTHEN ACROSS LAKE SUPERIOR. AT KCMX...LIFR/IFR CONDITIONS
SHOULD GENERALLY PREVAIL INTO THE EVENING HRS. ADVECTION OF SLIGHTLY
DRIER AIR AND A SLIGHT DOWNSLOPE COMPONENT TO THE WIND LATER
TONIGHT/SUN MORNING SHOULD HELP CIGS RISE TO MVFR AT KCMX. AT
KSAW...IFR CONDITIONS MAY RISE TO LOW MVFR THIS EVENING AS WINDS
SHIFT TO A LIGHT DOWNSLOPE DIRECTION. LIFR CONDITIONS EXPECTED LATER
TONIGHT/SUN AS UPSLOPE NNE WINDS STRENGTHEN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 423 PM EDT SAT OCT 13 2012
WINDS ARE IN THE PROCESS OF DIMINISHING ACROSS LAKE SUPERIOR AS LOW
PRES TROF/WEAKER PRES GRADIENT SHIFT OVER THE AREA. LATER TONIGHT
AND INTO SUN...N TO NE WINDS WILL INCREASE AS LOW PRES MOVES NE
TOWARD NRN LWR MICHIGAN. DURING SUN AFTN...WINDS SHOULD BE IN THE
20-30KT RANGE OVER THE CNTRL AND ERN PORTIONS OF LAKE SUPERIOR.
WINDS WILL BE LIGHTER OVER THE FAR W. SOME NORTHERLY GALE GUSTS OVER
EASTERN LAKE SUPERIOR ARE POSSIBLE INTO SUNDAY NIGHT AS THE LOW
MOVES EAST OF THE AREA AND HIGH PRESSURE PUSHES IN FROM THE WEST.
WINDS SETTLE DOWN MONDAY AND MONDAY NIGHT WITH ARRIVAL OF HIGH
PRESSURE. ANOTHER LOW PRESSURE WILL MOVE INTO THE UPPER GREAT LAKES
ON WEDNESDAY. SOUTH WINDS COULD PUSH UP TO 25 KTS AHEAD OF THE LOW
ON TUESDAY...MAINLY FOR EASTERN SECTIONS. OTHERWISE...WINDS IN THE
VICINITY OF THE LOW SHOULD REMAIN LESS THAN 20 KTS WEDNESDAY INTO
THURSDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...07
MARINE...ROLFSON/TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
407 PM EDT FRI OCT 12 2012
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 406 PM EDT FRI OCT 12 2012
WV IMAGERY AND RUC ANALYSIS INDICATED MAINLY ZONAL NRN STREAM
MID/UPPER LEVEL FLOW ACROSS THE NRN CONUS INTO THE WRN GREAT LAKES.
A VIGOROUS SRN STREAM LOW WAS LOCATED OVER NW AZ. AT THE SFC...SRLY
WINDS WERE INCREASING FROM THE PLAINS INTO THE UPPER MS VALLEY BTWN
HIGH PRES OVER LOWER MI AND A TROUGH DEVELOPING OVER THE WRN PLAINS.
VIS LOOP SHOWED DIURNAL CLOUDS OVER CNTRL UPPER MI THINNING AND
SHIFTING TO THE EAST AS SW WINDS DEVELOP. ANY LEFTOVER LAKE EFFECT
PCPN OVER ERN LAKE SUPERIOR HAD DISSIPATED
AS THE SFC HIGH SHIFTS TOWARD THE MID ATLANTIC STATES AND THE
SHRTWV/SFC LOW LIFTS OUT OF THE CENTRAL ROCKIES INTO THE PLAINS...A
STRENGTHENING SW FLOW WILL DEVELOP OVER THE WESTERN GREAT LAKES
TONIGHT. WITH STRONG WAA AND MOISTURE ADVECTION DEVELOPING WITH
MODERATE TO STRONG 295K-305K ISENTROPIC LIFT...RAIN WILL QUICKLY
DEVELOP AND SPREAD TO THE NORTHWEST. HOWEVER...WITH CONVECTION
LIKELY TO DEVELOP CLOSER TO THE SFC-850 MB WARM FRONT...MOISTURE
ADVECTION INTO UPPER MI MAY BE REDUCED. SO...THE NAM/ECMWF WHICH
INDICATES A SLIGHTLY LATER ARRIVAL(BTWN 09Z-12Z)OF THE PCPN WITH THE
HEAVIER PCPN MAINLY SOUTH OF UPPER MI WAS PREFERRED. EXPECT THE
STRONGER ISENTROPIC LIFT TO DIMINISH AND SHIFT TO THE EAST
DURING THE AFTERNOON AS THE SFC-850 MB WARM FRONT MOVES INTO NRN
LAKE MI AND NRN LWR MI. LIKELY TO CATEGORICAL POPS ARE STILL
WARRANTED ACROSS MUCH OF THE FCST AREA EVEN FOR PCPN AMOUNTS LESS
THAN 0.10 NORTHWEST...0.10 TO 0.25 INCH CNTRL TO NEAR 0.50 INCH EAST
AND FAR SOUTH.
INCREASING CLOUDS AND WIND WILL LIMIT THE DIURNAL FALL OF TEMP...AND
FCST THERMAL PROFILES INDICATE ANY PCPN SHOULD BE IN THE FORM OF
RAIN EVEN THOUGH TEMPS AT SOME OF THE INTERIOR COLD SPOTS MIGHT FALL
AOB 32 EARLY THIS EVENING BEFORE THE THICKER CLOUDS ARRIVE. EVEN
WITH THE STRONG WAA...PCPN AND CLOUDS WILL LIMIT HIGHS TO THE MID
AND UPPER 40S SATURDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 406 PM EDT FRI OCT 12 2012
MOST ATTENTION IN LONG TERM ON SAT NIGHT THROUGH SUN WITH A SYSTEM
THAT MAY BRING A COUPLE INCHES OF RAIN TO PARTS OF THE REGION. THERE
IS SOME UNCERTAINTY WITH THIS SYSTEM DUE TO MODEL DISAGREEMENT.
DIFFERENCES BETWEEN MODELS INITIALLY ARE DUE TO DIFFERENCES IN UPPER
LEVEL MASS FIELDS AS A 250MB LOW MOVES FROM THE CURRENT POSITION
OVER SRN NV...TO WRN KS AS A SHORTWAVE TROUGH AT THE START OF THE
PERIOD 00Z SUN. AT 00Z SUN...THE 00Z/12 ECMWF IS ABOUT 50-60M DEEPER
AND ALSO MORE NEUTRALLY TILTED WITH 250MB HEIGHT TROUGH THAN THE
POSITIVELY TILTED GFS. THE 12Z/12 NAM IS AN OUTLIER THROUGH THE
PERIOD AS WAS RULES OUT. THE REG-GEM IS MORE OF A MIDDLE GROUND
SOLUTION THROUGH MUCH OF THE EVENT.. THE DIFFERENCES BETWEEN MODELS
CONTINUES AT 12Z SUN...WHEN THE GFS BECOMES NEUTRALLY TILED OVER THE
WRN MO BORDER WHILE THE ECMWF IS STRONGER...FASTER AND NEGATIVELY
TILTED WITH THE UPPER TROUGH OVER IA/NRN MO. EVENTUAL SFC LOW TRACK
DIFFERENCES ARE NOT DIFFERENT...ALTHOUGH THERE ARE STILL DIFFERENCES
IN SFC LOW STRENGTH...BUT SOME OF THE LARGER DIFFERENCES WITH PRECIP
AMOUNTS/PLACEMENT COME AROUND 850MB. WHILE THE STRONGER ECMWF
DEEPENS THE SYSTEM AND BRINGS A STRENGTHENING 850MB LOW FROM NE IA
12Z SUN TO NEAR THE STRAITS OF MACKINAW AROUND 00Z MON...THE GFS
BRINGS THE 850MB LOW FROM NRN LAKE SUPERIOR AT 00Z SUN TO NEAR THE
STRAITS AT 18Z SUN...THEN DEEPENS IT RAPIDLY OVER LAKE HURON BY 00Z
MON AS THE UPPER TROUGH BECOMES NEGATIVELY TILTED AND UPPER JETS
PHASE. WILL BE INTERESTED TO SEE WHAT THE 12Z/12 ECMWF COMES IN
WITH...BECAUSE THE GFS AND GEM HAVE BEEN TRENDING WEAKER /TOWARD
WHAT THEY HAVE NOW/ OVER THE LAST FEW RUNS. THE MAIN IMPACT FROM THE
WEAKER SCENARIO IS THAT THE STRONG DEFORMATION/FGEN ON THE LEFT SIDE
OF THE 850MB LOW TRACK ARE DISPLACES SE OF THE CWA...WHILE THE ECMWF
SOLUTION BRINGS A COUPLE OF INCHES OF RAIN SAT NIGHT INTO SUN.
OVERALL THINK THE BEST CHANCES OF PRECIP WILL BE OVER THE SERN CWA
CLOSER TO LAKE MICHIGAN...BOTH SAT NIGHT WITH THE WARM FRONT THAT
WILL BE JUST S OF THE CWA AND AS THE LOW PASSES SUN. WILL SHIFT POPS
SE FROM WHAT IS CURRENTLY IN THE FORECAST.
LINGERED SOME SLIGHT CHANCE POPS OVER NORTH CENTRAL AND E UPPER MI
INTO EARLY MON AS N WINDS OFF LAKE SUPERIOR MAY BRING IN SOME LAKE
EFFECT/UPSLOPE PRECIP WHILE 850MB TEMPS DECREASE TO AROUND -3C. ANY
PRECIP WILL BE LIGHT...AND SOME SOME LIGHT SNOW MAY MIX IN OVER THE
HIGHER TERRAIN LATE SUN NIGHT/EARLY MON MORNING. AS SFC RIDGE SLIDES
ACROSS THE CWA MON AFTERNOON/EVENING AHEAD OF AN UPPER RIDGE THAT
WILL MOVE OVERHEAD TUE NIGHT INTO EARLY TUE.
AFTER MON THERE IS CONSIDERABLE MODEL DISAGREEMENT...LIMITED
CONFIDENCE IN THE FORECAST...ESPECIALLY POPS. HOWEVER...IT DOES
APPEAR MORE CERTAIN THAT TUE AND WED WILL BE WARMER WITH HIGHS
GENERALLY IN THE 50S. USED CONSENSUS OF MODELS FOR MON NIGHT THROUGH
FRI.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 135 PM EDT FRI OCT 12 2012
AS A DRY HIGH PRES RIDGE MOVES ACROSS THE UPPER GREAT LAKES...EXPECT
VFR CONDITIONS TO PREDOMINATE INTO TONIGHT. A STRENGTHENING SSW FLOW
TONIGHT BTWN THE DEPARTING HI AND LOW PRES TAKING SHAPE IN THE PLAINS
WILL RESULT IN SOME MARGINAL LLWS AS WELL AS INCREASING CLOUDS.
ENOUGH MOISTURE MAY ARRIVE LATE IN THE FCST PERIOD TO CAUSE MVFR CIGS
CLOSER TO THE WI BORDER AT IWD. STRONGER MOISTURE INFLOW AHEAD OF
WARM FRONT OVER WI WILL BRING LOWER CIGS INTO THE MVFR RANGE. SRLY
LOW LEVEL FLOW FAVORS EVEN LOWER CIGS INTO THE IFR RANGE AT SAW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 406 PM EDT FRI OCT 12 2012
A STEADY SSW WIND UP TO 25 KTS WILL PREVAIL TONIGHT BETWEEN THE
DEPARTING HI AND DEVELOPING LO PRES IN THE PLAINS. AS THE LO PRES
CENTER MOVES TO THE E JUST S OF UPPER MI EARLY SUN...LOOK FOR THE
WINDS TO BACK TO THE N AND INCREASE UP TO 25 TO 30 KTS...ESPECIALLY
OVER THE E HALF. MAY SEE A FEW GALE FORCE GUSTS OVER PORTIONS OF
EASTERN LAKE SUPERIOR SUN. THE APPROACH OF HIGH PRES ON MON WILL CAUSE
A STEADY DECREASE IN WIND SPEED LATER SUN INTO MON. SOUTH WINDS WILL
INCREASE TO 25 KTS OVER MAINLY THE ERN HALF OF THE LAKE ON TUESDAY
AHEAD OF A LOW PRESSURE SYSTEM DEVELOPING OVER THE NRN PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
139 PM EDT FRI OCT 12 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 606 AM EDT FRI OCT 12 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW CONFLUENT NW FLOW
ALF OVER THE UPR GRT LKS BTWN TROFFING OVER ERN CANADA AND A RDG
OVER WRN CANADA. AT THE SFC...HI PRES IS CENTERED OVER WRN MN...WITH
CHILLY /H85 TEMPS -7C TO -8C/ NW FLOW DOMINATING THE CWA. DESPITE
RATHER MOIST LOOK TO 00Z INL/YPL RAOBS AND SUFFICIENT INSTABILITY
FOR LK EFFECT PCPN /LK SUP WATER TEMPS 8C OVER THE W TO 10C OVER THE
E/...THE BULK OF THE LK EFFECT SHRASN AND FOR THAT MATTER THE LO
CLDS ARE CONFINED TO AN AREA OVER THE ECNTRL PART OF THE LK...WHERE
THE SFC OBS INDICATE SOME LLVL CNVGC BTWN THE LARGER SCALE NW FLOW
AND A MORE NNE LAND BREEZE FLOW OFF SE ONTARIO ENHANCE BY DIURNAL
COOLING THERE. SEEMS LIKE INTENSE SUBIDENCE/DRYING ALF IN THE WAKE
OF SHRTWV THAT PASSED YDAY AS WELL AS LARGER SCALE ACYC FLOW
ASSOCIATED WITH MN HI PRES IS SUPPRESSING THE PCPN/CLD COVER.
HOWEVER...MQT RADAR DOES INDICATE SOME REFLECTIVIES OVER 30DBZ
WITHIN THE MORE INTENSE SHRASN STREAMING INTO ALGER/NRN SCHOOLCRAFT
COUNTIES.
MAIN FCST CONCERNS IN THE SHORT TERM ARE LK EFFECT SHRASN TRENDS
THIS MRNG. FOCUS FOR LATER TNGT SHIFTS TO CHC OF PCPN AS DVLPG SW
WIND ON THE WRN FLANK OF RETREATING HI PRES IS PROGGED TO ADVECT
MUCH MOISTER AIR NEWD INTO THE UPR LKS.
TODAY...WITH RISING H5 HGTS THRU THE DAY...SFC HI PRES CENTER IS
PROGGED TO MOVE STEADILY ESEWD TO OVER LAKE ERIE BY 00Z SAT. AS THE
LLVL FLOW BACKS TO THE SW THIS AFTN AND ADVECTS MUCH DRIER AIR SHOWN
ON THE 00Z MPX RAOB INTO THE UPR LKS...EXPECT LK EFFECT SHRASN OVER
THE E TO BECOME INCRSGLY CONFINED TO NEAR THE SHORE E OF GRAND
MARAIS AND THEN END COMPLETELY IN THE AFTN IN THE PRESENCE OF
DAYTIME HEATING. TO THE W...ANY LINGERING LK CLDS SHOULD GIVE WAY TO
MOSUNNY CONDITIONS/SCT CU WITH THE ARRIVAL OF THE DRIER AIR FM THE
SW. DIURNAL SC MIGHT BE MORE RESILIENT OVER THE E WITH LINGERING H85
THERMAL TROF/H85 TEMPS ARND -5C THRU 00Z. PER MIXING TO H85-8 ON NAM
FCST SDNGS AND HI TEMPS OBSVD UPSTREAM YDAY...EXPECT MAX TEMPS IN
THE 40S.
TNGT...AS THE SFC HI SHIFTS TOWARD THE MID ATLANTIC STATES AND A
SHRTWV/SFC LO SHIFT OUT OF THE CENTRAL ROCKIES INTO THE PLAINS...A
STRENGTHENING SW FLOW IS FCST TO DVLP OVER THE UPR LKS. MOST RECENT
MODEL RUNS HAVE BEEN CONSISTENT IN GENERATING SOME LGT PCPN OVER
MUCH OF THE W HALF OF THE CWA IN THIS WAD REGIME FEATURING
IMPRESSIVE ISENTROPIC ASCENT ON THE 295-305K SFCS THAT ADVECTS PWAT
UP TO 1 INCH /175-200 PCT OF NORMAL/ NEAR THE WI BORDER BY 12Z SAT.
ALTHOUGH THE BETTER HGT FALLS/DPVA/UPR DVGC LAG TO THE W CLOSER TO
THE SHRTWV IN THE PLAINS SO THAT THE LYR ABV H65-6 REMAINS
RELATIVELY DRY /INCLUDING THE DGZ/...THIS IMPRESSIVE WAD/MOISTENING
JUSTIFIES AT LEAST LO CHC POPS OVER THE W HALF NEAR THE WI BORDER.
INCRSG CLDS/WINDS WL LIMIT THE DIURNAL FALL OF TEMP...AND FCST
THERMAL PROFILES INDICATE ANY PCPN SHOULD BE IN THE FORM OF RA EVEN
THOUGH TEMPS AT SOME OF THE INTERIOR COLD SPOTS MIGHT FALL AOB 32
EARLY IN THE EVNG BEFORE THE THICKER CLDS ARRIVE.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 606 AM EDT FRI OCT 12 2012
AS THE MID LEVEL TROUGH AND ASSOC SFC LOW MOVE OUT OVER THE CENTRAL
PLAINS ON SAT...STRONG WAA/ISENTROPIC ASCENT WILL CONTINUE OVER THE
FCST AREA...ESPECIALLY THRU MID DAY SAT. LIKELY TO CATEGORICAL POPS
ARE STILL WARRANTED ACROSS MUCH OF THE FCST AREA. SINCE MODELS ARE
INDICATING THE STRONGEST PUSH OF 295-300K ASCENT OVER SCNTRL AND ERN
UPPER MI...WILL MAINTAIN HIGHEST CATEGORICAL POPS 80-90 PCT OVER
THESE AREAS WHILE TAPERING POPS TO CHC 40-50 OVER NW AWAY FM BEST
WAA/ISNETROPIC ASCENT.
SAT NIGHT/SUN...MODELS SHOW SHORTWAVE TROUGH OVER THE PLAINS LIFTING
NE...CROSSING LWR MI SUN WITH ASSOCIATED SFC LOW TRACKING THRU NRN
LWR MI. THE GFS IS A BIT FASTER THAN THE ECMWF/CANADIAN SOLN BUT ALL
THESE MODELS HAVE THE SFC LOW TRACKING ACROSS NRN LOWER MI FM EITHER
EARLY SUN AFTERNOON (GFS) TO LATE SUN AFTERNOON (ECMWF/CANADIAN).
BASED ON THIS SFC LOW TRACK WHICH IS JUST SOUTH OF THE PROGGED TRACK
OF THE 850 MB...WOULD EXPECT DEFORMATION ZONE/HEAVIEST RAINFALL TO
CROSS THE S CENTRAL AND ERN PORTIONS OF THE FCST AREA. THESE AREAS
OF THE CWA ALSO LINE UP WITH MODEL INDICATED DEEP LAYER Q-VECT CONV
AND ARE CO-LOCATED WITH COUPLED UPPER JET STRUCTURE AND ALONG AND
SOUTH OF ASSOC 850 MB FGEN FORCING. AGAIN HAVE TAPERING POPS FROM
90-100 PCT SCNTRL AND EAST TO CHC POPS (30-40 PCT) FAR WEST FOR SAT
NIGHT AND SUNDAY. LOOKING AT MODEL AVG QPF...WOULD EXPECT TO SEE
RAINFALL AMOUNTS WELL OVER AN INCH OVER SCNTRL AND ERN PORTIONS OF
THE CWA WITH SOME LOCATIONS PERHAPS APPROACHING TWO INCHES. AS
SYSTEM CONTINUES TO LIFT NE...DRYING TREND WILL GET UNDERWAY FROM W
TO E LATE IN THE DAY SUN. THE DRYING TREND WILL CONTINUE SUNDAY
NIGHT AS HIGH PRES BUILDS IN FM THE WEST.
WITH SFC HIGH PRES RIDGE PASSING OVER THE AREA MON...EXPECT A DRY
DAY AFTER PERHAPS TO FEW LINGERING SHOWERS EARLY MORNING EAST.
STILL PLENTY OF MODEL UNCERTAINTY FOR NEXT WEEK. MORE ZONAL FLOW FOR
EARLY NEXT WEEK WITH WAA AND POTENTIAL FOR WEAK SHORTWAVES MOVING
THROUGH REGION COULD SUPPORT SOME LIGHT RAIN CHCS LATE MON NIGHT
INTO TUESDAY. MODELS THEN DIFFER ON HOW MUCH MID LVL TROF WILL
AMPLIFY OVER THE PLAINS FOR MID TO LATE NEXT WEEK. UNTIL MODELS COME
INTO BETTER AGREEMENT ON TROF EVOLUTION WILL MAINTAIN GOING CHC POPS
FOR MID TO LATE NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 135 PM EDT FRI OCT 12 2012
AS A DRY HIGH PRES RIDGE MOVES ACROSS THE UPPER GREAT LAKES...EXPECT
VFR CONDITIONS TO PREDOMINATE INTO TONIGHT. A STRENGTHENING SSW FLOW
TONIGHT BTWN THE DEPARTING HI AND LOW PRES TAKING SHAPE IN THE PLAINS
WILL RESULT IN SOME MARGINAL LLWS AS WELL AS INCREASING CLOUDS.
ENOUGH MOISTURE MAY ARRIVE LATE IN THE FCST PERIOD TO CAUSE MVFR CIGS
CLOSER TO THE WI BORDER AT IWD. STRONGER MOISTURE INFLOW AHEAD OF
WARM FRONT OVER WI WILL BRING LOWER CIGS INTO THE MVFR RANGE. SRLY
LOW LEVEL FLOW FAVORS EVEN LOWER CIGS INTO THE IFR RANGE AT SAW. &&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 606 AM EDT FRI OCT 12 2012
EXPECT NW WINDS UP TO 25 KTS OVER THE HALF OF THE LAKE THIS MORNING
TO BACK STEADILY TO THE SW TODAY AS THE HI PRES CENTER OVER MN MOVES
STEADILY TO LAKE ERIE BY THIS EVENING. A STEADY SSW WIND UP TO 25
KTS WILL PREVAIL TONIGHT BETWEEN THE DEPARTING HI AND DEVELOPING LO
PRES IN THE PLAINS. AS THE LO PRES CENTER MOVES TO THE E JUST S OF
UPPER MI EARLY SUN...LOOK FOR THE WINDS TO BACK TO THE N AND
INCREASE UP TO 25 TO 30 KTS...ESPECIALLY OVER THE E HALF. MAY SEE A
FEW GALE FORCE GUSTS OVER PORTIONS OF EASTERN LAKE SUPERIOR SUN. THE
APPROACH OF HI PRES ON MON WILL CAUSE A STEADY DECREASE IN WIND
SPEED LATER SUN INTO MON. SOUTH WINDS WILL INCREASE TO 25 KTS OVER
MAINLY THE ERN HALF OF THE LAKE ON TUESDAY AHEAD OF A LOW PRESSURE
SYSTEM DEVELOPING OVER THE NRN PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...VOSS
AVIATION...JLB
MARINE...KC/VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
723 AM EDT FRI OCT 12 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 606 AM EDT FRI OCT 12 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW CONFLUENT NW FLOW
ALF OVER THE UPR GRT LKS BTWN TROFFING OVER ERN CANADA AND A RDG
OVER WRN CANADA. AT THE SFC...HI PRES IS CENTERED OVER WRN MN...WITH
CHILLY /H85 TEMPS -7C TO -8C/ NW FLOW DOMINATING THE CWA. DESPITE
RATHER MOIST LOOK TO 00Z INL/YPL RAOBS AND SUFFICIENT INSTABILITY
FOR LK EFFECT PCPN /LK SUP WATER TEMPS 8C OVER THE W TO 10C OVER THE
E/...THE BULK OF THE LK EFFECT SHRASN AND FOR THAT MATTER THE LO
CLDS ARE CONFINED TO AN AREA OVER THE ECNTRL PART OF THE LK...WHERE
THE SFC OBS INDICATE SOME LLVL CNVGC BTWN THE LARGER SCALE NW FLOW
AND A MORE NNE LAND BREEZE FLOW OFF SE ONTARIO ENHANCE BY DIURNAL
COOLING THERE. SEEMS LIKE INTENSE SUBIDENCE/DRYING ALF IN THE WAKE
OF SHRTWV THAT PASSED YDAY AS WELL AS LARGER SCALE ACYC FLOW
ASSOCIATED WITH MN HI PRES IS SUPPRESSING THE PCPN/CLD COVER.
HOWEVER...MQT RADAR DOES INDICATE SOME REFLECTIVIES OVER 30DBZ
WITHIN THE MORE INTENSE SHRASN STREAMING INTO ALGER/NRN SCHOOLCRAFT
COUNTIES.
MAIN FCST CONCERNS IN THE SHORT TERM ARE LK EFFECT SHRASN TRENDS
THIS MRNG. FOCUS FOR LATER TNGT SHIFTS TO CHC OF PCPN AS DVLPG SW
WIND ON THE WRN FLANK OF RETREATING HI PRES IS PROGGED TO ADVECT
MUCH MOISTER AIR NEWD INTO THE UPR LKS.
TODAY...WITH RISING H5 HGTS THRU THE DAY...SFC HI PRES CENTER IS
PROGGED TO MOVE STEADILY ESEWD TO OVER LAKE ERIE BY 00Z SAT. AS THE
LLVL FLOW BACKS TO THE SW THIS AFTN AND ADVECTS MUCH DRIER AIR SHOWN
ON THE 00Z MPX RAOB INTO THE UPR LKS...EXPECT LK EFFECT SHRASN OVER
THE E TO BECOME INCRSGLY CONFINED TO NEAR THE SHORE E OF GRAND
MARAIS AND THEN END COMPLETELY IN THE AFTN IN THE PRESENCE OF
DAYTIME HEATING. TO THE W...ANY LINGERING LK CLDS SHOULD GIVE WAY TO
MOSUNNY CONDITIONS/SCT CU WITH THE ARRIVAL OF THE DRIER AIR FM THE
SW. DIURNAL SC MIGHT BE MORE RESILIENT OVER THE E WITH LINGERING H85
THERMAL TROF/H85 TEMPS ARND -5C THRU 00Z. PER MIXING TO H85-8 ON NAM
FCST SDNGS AND HI TEMPS OBSVD UPSTREAM YDAY...EXPECT MAX TEMPS IN
THE 40S.
TNGT...AS THE SFC HI SHIFTS TOWARD THE MID ATLANTIC STATES AND A
SHRTWV/SFC LO SHIFT OUT OF THE CENTRAL ROCKIES INTO THE PLAINS...A
STRENGTHENING SW FLOW IS FCST TO DVLP OVER THE UPR LKS. MOST RECENT
MODEL RUNS HAVE BEEN CONSISTENT IN GENERATING SOME LGT PCPN OVER
MUCH OF THE W HALF OF THE CWA IN THIS WAD REGIME FEATURING
IMPRESSIVE ISENTROPIC ASCENT ON THE 295-305K SFCS THAT ADVECTS PWAT
UP TO 1 INCH /175-200 PCT OF NORMAL/ NEAR THE WI BORDER BY 12Z SAT.
ALTHOUGH THE BETTER HGT FALLS/DPVA/UPR DVGC LAG TO THE W CLOSER TO
THE SHRTWV IN THE PLAINS SO THAT THE LYR ABV H65-6 REMAINS
RELATIVELY DRY /INCLUDING THE DGZ/...THIS IMPRESSIVE WAD/MOISTENING
JUSTIFIES AT LEAST LO CHC POPS OVER THE W HALF NEAR THE WI BORDER.
INCRSG CLDS/WINDS WL LIMIT THE DIURNAL FALL OF TEMP...AND FCST
THERMAL PROFILES INDICATE ANY PCPN SHOULD BE IN THE FORM OF RA EVEN
THOUGH TEMPS AT SOME OF THE INTERIOR COLD SPOTS MIGHT FALL AOB 32
EARLY IN THE EVNG BEFORE THE THICKER CLDS ARRIVE.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 606 AM EDT FRI OCT 12 2012
AS THE MID LEVEL TROUGH AND ASSOC SFC LOW MOVE OUT OVER THE CENTRAL
PLAINS ON SAT...STRONG WAA/ISENTROPIC ASCENT WILL CONTINUE OVER THE
FCST AREA...ESPECIALLY THRU MID DAY SAT. LIKELY TO CATEGORICAL POPS
ARE STILL WARRANTED ACROSS MUCH OF THE FCST AREA. SINCE MODELS ARE
INDICATING THE STRONGEST PUSH OF 295-300K ASCENT OVER SCNTRL AND ERN
UPPER MI...WILL MAINTAIN HIGHEST CATEGORICAL POPS 80-90 PCT OVER
THESE AREAS WHILE TAPERING POPS TO CHC 40-50 OVER NW AWAY FM BEST
WAA/ISNETROPIC ASCENT.
SAT NIGHT/SUN...MODELS SHOW SHORTWAVE TROUGH OVER THE PLAINS LIFTING
NE...CROSSING LWR MI SUN WITH ASSOCIATED SFC LOW TRACKING THRU NRN
LWR MI. THE GFS IS A BIT FASTER THAN THE ECMWF/CANADIAN SOLN BUT ALL
THESE MODELS HAVE THE SFC LOW TRACKING ACROSS NRN LOWER MI FM EITHER
EARLY SUN AFTERNOON (GFS) TO LATE SUN AFTERNOON (ECMWF/CANADIAN).
BASED ON THIS SFC LOW TRACK WHICH IS JUST SOUTH OF THE PROGGED TRACK
OF THE 850 MB...WOULD EXPECT DEFORMATION ZONE/HEAVIEST RAINFALL TO
CROSS THE S CENTRAL AND ERN PORTIONS OF THE FCST AREA. THESE AREAS
OF THE CWA ALSO LINE UP WITH MODEL INDICATED DEEP LAYER Q-VECT CONV
AND ARE CO-LOCATED WITH COUPLED UPPER JET STRUCTURE AND ALONG AND
SOUTH OF ASSOC 850 MB FGEN FORCING. AGAIN HAVE TAPERING POPS FROM
90-100 PCT SCNTRL AND EAST TO CHC POPS (30-40 PCT) FAR WEST FOR SAT
NIGHT AND SUNDAY. LOOKING AT MODEL AVG QPF...WOULD EXPECT TO SEE
RAINFALL AMOUNTS WELL OVER AN INCH OVER SCNTRL AND ERN PORTIONS OF
THE CWA WITH SOME LOCATIONS PERHAPS APPROACHING TWO INCHES. AS
SYSTEM CONTINUES TO LIFT NE...DRYING TREND WILL GET UNDERWAY FROM W
TO E LATE IN THE DAY SUN. THE DRYING TREND WILL CONTINUE SUNDAY
NIGHT AS HIGH PRES BUILDS IN FM THE WEST.
WITH SFC HIGH PRES RIDGE PASSING OVER THE AREA MON...EXPECT A DRY
DAY AFTER PERHAPS TO FEW LINGERING SHOWERS EARLY MORNING EAST.
STILL PLENTY OF MODEL UNCERTAINTY FOR NEXT WEEK. MORE ZONAL FLOW FOR
EARLY NEXT WEEK WITH WAA AND POTENTIAL FOR WEAK SHORTWAVES MOVING
THROUGH REGION COULD SUPPORT SOME LIGHT RAIN CHCS LATE MON NIGHT
INTO TUESDAY. MODELS THEN DIFFER ON HOW MUCH MID LVL TROF WILL
AMPLIFY OVER THE PLAINS FOR MID TO LATE NEXT WEEK. UNTIL MODELS COME
INTO BETTER AGREEMENT ON TROF EVOLUTION WILL MAINTAIN GOING CHC POPS
FOR MID TO LATE NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 722 AM EDT FRI OCT 12 2012
AS A DRY HI PRES RDG MOVES ACRS THE UPR LKS...EXPECT VFR CONDITIONS
TO PREDOMINATE INTO TNGT. THE ONE EXCEPTION WILL BE AT CMX THIS
MRNG...WHERE UPSLOPE WNW FLOW WL RESULT IN SOME MVFR CIGS AT TIMES.
A STRENGTHENING SSW FLOW TNGT BTWN THE DEPARTING HI AND LO PRES
TAKING SHAPE IN THE PLAINS WL RESULT IN SOME MARGINAL LLWS AS WELL AS
INCRSG CLDS. ENUF MSTR MAY ARRIVE LATE IN THE FCST PERIOD TO CAUSE
MVFR CIGS CLOSER TO THE WI BORDER AT IWD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 606 AM EDT FRI OCT 12 2012
EXPECT NW WINDS UP TO 25 KTS OVER THE HALF OF THE LAKE THIS MORNING
TO BACK STEADILY TO THE SW TODAY AS THE HI PRES CENTER OVER MN MOVES
STEADILY TO LAKE ERIE BY THIS EVENING. A STEADY SSW WIND UP TO 25
KTS WILL PREVAIL TONIGHT BETWEEN THE DEPARTING HI AND DEVELOPING LO
PRES IN THE PLAINS. AS THE LO PRES CENTER MOVES TO THE E JUST S OF
UPPER MI EARLY SUN...LOOK FOR THE WINDS TO BACK TO THE N AND
INCREASE UP TO 25 TO 30 KTS...ESPECIALLY OVER THE E HALF. MAY SEE A
FEW GALE FORCE GUSTS OVER PORTIONS OF EASTERN LAKE SUPERIOR SUN. THE
APPROACH OF HI PRES ON MON WILL CAUSE A STEADY DECREASE IN WIND
SPEED LATER SUN INTO MON. SOUTH WINDS WILL INCREASE TO 25 KTS OVER
MAINLY THE ERN HALF OF THE LAKE ON TUESDAY AHEAD OF A LOW PRESSURE
SYSTEM DEVELOPING OVER THE NRN PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...VOSS
AVIATION...KC
MARINE...KC/VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
608 AM EDT FRI OCT 12 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 606 AM EDT FRI OCT 12 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW CONFLUENT NW FLOW
ALF OVER THE UPR GRT LKS BTWN TROFFING OVER ERN CANADA AND A RDG
OVER WRN CANADA. AT THE SFC...HI PRES IS CENTERED OVER WRN MN...WITH
CHILLY /H85 TEMPS -7C TO -8C/ NW FLOW DOMINATING THE CWA. DESPITE
RATHER MOIST LOOK TO 00Z INL/YPL RAOBS AND SUFFICIENT INSTABILITY
FOR LK EFFECT PCPN /LK SUP WATER TEMPS 8C OVER THE W TO 10C OVER THE
E/...THE BULK OF THE LK EFFECT SHRASN AND FOR THAT MATTER THE LO
CLDS ARE CONFINED TO AN AREA OVER THE ECNTRL PART OF THE LK...WHERE
THE SFC OBS INDICATE SOME LLVL CNVGC BTWN THE LARGER SCALE NW FLOW
AND A MORE NNE LAND BREEZE FLOW OFF SE ONTARIO ENHANCE BY DIURNAL
COOLING THERE. SEEMS LIKE INTENSE SUBIDENCE/DRYING ALF IN THE WAKE
OF SHRTWV THAT PASSED YDAY AS WELL AS LARGER SCALE ACYC FLOW
ASSOCIATED WITH MN HI PRES IS SUPPRESSING THE PCPN/CLD COVER.
HOWEVER...MQT RADAR DOES INDICATE SOME REFLECTIVIES OVER 30DBZ
WITHIN THE MORE INTENSE SHRASN STREAMING INTO ALGER/NRN SCHOOLCRAFT
COUNTIES.
MAIN FCST CONCERNS IN THE SHORT TERM ARE LK EFFECT SHRASN TRENDS
THIS MRNG. FOCUS FOR LATER TNGT SHIFTS TO CHC OF PCPN AS DVLPG SW
WIND ON THE WRN FLANK OF RETREATING HI PRES IS PROGGED TO ADVECT
MUCH MOISTER AIR NEWD INTO THE UPR LKS.
TODAY...WITH RISING H5 HGTS THRU THE DAY...SFC HI PRES CENTER IS
PROGGED TO MOVE STEADILY ESEWD TO OVER LAKE ERIE BY 00Z SAT. AS THE
LLVL FLOW BACKS TO THE SW THIS AFTN AND ADVECTS MUCH DRIER AIR SHOWN
ON THE 00Z MPX RAOB INTO THE UPR LKS...EXPECT LK EFFECT SHRASN OVER
THE E TO BECOME INCRSGLY CONFINED TO NEAR THE SHORE E OF GRAND
MARAIS AND THEN END COMPLETELY IN THE AFTN IN THE PRESENCE OF
DAYTIME HEATING. TO THE W...ANY LINGERING LK CLDS SHOULD GIVE WAY TO
MOSUNNY CONDITIONS/SCT CU WITH THE ARRIVAL OF THE DRIER AIR FM THE
SW. DIURNAL SC MIGHT BE MORE RESILIENT OVER THE E WITH LINGERING H85
THERMAL TROF/H85 TEMPS ARND -5C THRU 00Z. PER MIXING TO H85-8 ON NAM
FCST SDNGS AND HI TEMPS OBSVD UPSTREAM YDAY...EXPECT MAX TEMPS IN
THE 40S.
TNGT...AS THE SFC HI SHIFTS TOWARD THE MID ATLANTIC STATES AND A
SHRTWV/SFC LO SHIFT OUT OF THE CENTRAL ROCKIES INTO THE PLAINS...A
STRENGTHENING SW FLOW IS FCST TO DVLP OVER THE UPR LKS. MOST RECENT
MODEL RUNS HAVE BEEN CONSISTENT IN GENERATING SOME LGT PCPN OVER
MUCH OF THE W HALF OF THE CWA IN THIS WAD REGIME FEATURING
IMPRESSIVE ISENTROPIC ASCENT ON THE 295-305K SFCS THAT ADVECTS PWAT
UP TO 1 INCH /175-200 PCT OF NORMAL/ NEAR THE WI BORDER BY 12Z SAT.
ALTHOUGH THE BETTER HGT FALLS/DPVA/UPR DVGC LAG TO THE W CLOSER TO
THE SHRTWV IN THE PLAINS SO THAT THE LYR ABV H65-6 REMAINS
RELATIVELY DRY /INCLUDING THE DGZ/...THIS IMPRESSIVE WAD/MOISTENING
JUSTIFIES AT LEAST LO CHC POPS OVER THE W HALF NEAR THE WI BORDER.
INCRSG CLDS/WINDS WL LIMIT THE DIURNAL FALL OF TEMP...AND FCST
THERMAL PROFILES INDICATE ANY PCPN SHOULD BE IN THE FORM OF RA EVEN
THOUGH TEMPS AT SOME OF THE INTERIOR COLD SPOTS MIGHT FALL AOB 32
EARLY IN THE EVNG BEFORE THE THICKER CLDS ARRIVE.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 606 AM EDT FRI OCT 12 2012
AS THE MID LEVEL TROUGH AND ASSOC SFC LOW MOVE OUT OVER THE CENTRAL
PLAINS ON SAT...STRONG WAA/ISENTROPIC ASCENT WILL CONTINUE OVER THE
FCST AREA...ESPECIALLY THRU MID DAY SAT. LIKELY TO CATEGORICAL POPS
ARE STILL WARRANTED ACROSS MUCH OF THE FCST AREA. SINCE MODELS ARE
INDICATING THE STRONGEST PUSH OF 295-300K ASCENT OVER SCNTRL AND ERN
UPPER MI...WILL MAINTAIN HIGHEST CATEGORICAL POPS 80-90 PCT OVER
THESE AREAS WHILE TAPERING POPS TO CHC 40-50 OVER NW AWAY FM BEST
WAA/ISNETROPIC ASCENT.
SAT NIGHT/SUN...MODELS SHOW SHORTWAVE TROUGH OVER THE PLAINS LIFTING
NE...CROSSING LWR MI SUN WITH ASSOCIATED SFC LOW TRACKING THRU NRN
LWR MI. THE GFS IS A BIT FASTER THAN THE ECMWF/CANADIAN SOLN BUT ALL
THESE MODELS HAVE THE SFC LOW TRACKING ACROSS NRN LOWER MI FM EITHER
EARLY SUN AFTERNOON (GFS) TO LATE SUN AFTERNOON (ECMWF/CANADIAN).
BASED ON THIS SFC LOW TRACK WHICH IS JUST SOUTH OF THE PROGGED TRACK
OF THE 850 MB...WOULD EXPECT DEFORMATION ZONE/HEAVIEST RAINFALL TO
CROSS THE S CENTRAL AND ERN PORTIONS OF THE FCST AREA. THESE AREAS
OF THE CWA ALSO LINE UP WITH MODEL INDICATED DEEP LAYER Q-VECT CONV
AND ARE CO-LOCATED WITH COUPLED UPPER JET STRUCTURE AND ALONG AND
SOUTH OF ASSOC 850 MB FGEN FORCING. AGAIN HAVE TAPERING POPS FROM
90-100 PCT SCNTRL AND EAST TO CHC POPS (30-40 PCT) FAR WEST FOR SAT
NIGHT AND SUNDAY. LOOKING AT MODEL AVG QPF...WOULD EXPECT TO SEE
RAINFALL AMOUNTS WELL OVER AN INCH OVER SCNTRL AND ERN PORTIONS OF
THE CWA WITH SOME LOCATIONS PERHAPS APPROACHING TWO INCHES. AS
SYSTEM CONTINUES TO LIFT NE...DRYING TREND WILL GET UNDERWAY FROM W
TO E LATE IN THE DAY SUN. THE DRYING TREND WILL CONTINUE SUNDAY
NIGHT AS HIGH PRES BUILDS IN FM THE WEST.
WITH SFC HIGH PRES RIDGE PASSING OVER THE AREA MON...EXPECT A DRY
DAY AFTER PERHAPS TO FEW LINGERING SHOWERS EARLY MORNING EAST.
STILL PLENTY OF MODEL UNCERTAINTY FOR NEXT WEEK. MORE ZONAL FLOW FOR
EARLY NEXT WEEK WITH WAA AND POTENTIAL FOR WEAK SHORTWAVES MOVING
THROUGH REGION COULD SUPPORT SOME LIGHT RAIN CHCS LATE MON NIGHT
INTO TUESDAY. MODELS THEN DIFFER ON HOW MUCH MID LVL TROF WILL
AMPLIFY OVER THE PLAINS FOR MID TO LATE NEXT WEEK. UNTIL MODELS COME
INTO BETTER AGREEMENT ON TROF EVOLUTION WILL MAINTAIN GOING CHC POPS
FOR MID TO LATE NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 127 AM EDT FRI OCT 12 2012
PREDOMINATE NW WINDS OFF LAKE SUPERIOR WILL KEEP MOISTURE ENOUGH TO
PRODUCE SCT TO BKN CLOUD COVER WITH VFR CONDITIONS OVERNIGHT. BY
FRIDAY MORNING...A HIGH PRESSURE RIDGE WILL CAUSE A WIND SHIFT TO
THE WEST /AND EVENTUALLY TO THE SOUTHWEST BY 18Z/. IN DOING
SO...KCMX WILL SEE LINGERING MOISTURE AND RESULTING CLOUD COVER OFF
THE LAKE THROUGH THE AFTERNOON. HOWEVER THIS SHOULD CUT OFF MOISTURE
SOURCE FOR KIWD AND KSAW...SO EXPECT THESE SITES TO CLEAR OUT. PUT
IN SOME LLWS FOR ALL 3 SITES FRI EVENING AHEAD OF THE NEXT SYSTEM TO
AFFECT THE AREA.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 606 AM EDT FRI OCT 12 2012
EXPECT NW WINDS UP TO 25 KTS OVER THE HALF OF THE LAKE THIS MORNING
TO BACK STEADILY TO THE SW TODAY AS THE HI PRES CENTER OVER MN MOVES
STEADILY TO LAKE ERIE BY THIS EVENING. A STEADY SSW WIND UP TO 25
KTS WILL PREVAIL TONIGHT BETWEEN THE DEPARTING HI AND DEVELOPING LO
PRES IN THE PLAINS. AS THE LO PRES CENTER MOVES TO THE E JUST S OF
UPPER MI EARLY SUN...LOOK FOR THE WINDS TO BACK TO THE N AND
INCREASE UP TO 25 TO 30 KTS...ESPECIALLY OVER THE E HALF. MAY SEE A
FEW GALE FORCE GUSTS OVER PORTIONS OF EASTERN LAKE SUPERIOR SUN. THE
APPROACH OF HI PRES ON MON WILL CAUSE A STEADY DECREASE IN WIND
SPEED LATER SUN INTO MON. SOUTH WINDS WILL INCREASE TO 25 KTS OVER
MAINLY THE ERN HALF OF THE LAKE ON TUESDAY AHEAD OF A LOW PRESSURE
SYSTEM DEVELOPING OVER THE NRN PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...VOSS
AVIATION...07
MARINE...KC/VOSS
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
934 AM MDT FRI OCT 12 2012
.SHORT TERM...VALID FOR TDY AND SAT...
UPDATE TO ZFP AND WRKAFP. AREAS OF DENSE FOG WERE HOLDING IN
PLACE ALONG PORTIONS OF THE YELLOWSTONE AND MUSSELSHELL RIVER
VALLEYS THIS MORNING PER SPOTTER REPORTS...SATELLITE IMAGERY AND
THE KBIL SURFACE OBSERVATION. LATEST HRRR SHOWED THE FOG BURNING
OFF BETWEEN 16 AND 17Z. ADJUSTED GRIDS TO REFLECT INCREASED SKY
COVER AND FOG OVER THESE AREAS THIS MORNING. ALSO LOWERED
TEMPERATURES 5 TO 10 DEGREES IN THE FOG AREAS AS A FEW HOURS OF
GOOD DAYTIME HEATING WERE LOST THIS MORNING. WRF BUFKIT SOUNDINGS
CONTINUED TO ADVERTISE MIXING BETWEEN 600 MB W TO 800 MB E THIS
AFTERNOON...RESULTING IN TEMPERATURES IN THE 70S OVER MANY AREAS.
UPPER LOW OVER THE NV/CA BORDER IN WATER VAPOR IMAGERY THIS
MORNING WILL MOVE E THIS AFTERNOON. NEW WRF HAD ENERGY AND
MOISTURE FROM THE LOW REMAINING SOUTH OF THE FORECAST AREA.
REMAINDER OF FORECAST LOOKED FINE FOR NOW. ARTHUR
.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...
ONLY A FEW CHANGES AGAIN THIS MORNING TO THE EXTENDED
FORECAST...MAINLY CONTINUING TO TREND TEMPS SLIGHTLY
HIGHER...TOWARDS MEX GUIDANCE AND MIX DOWN NUMBERS. OVERALL...THE
EXTENDED FORECAST IS LOOKING WINDY AND MILD...WITH GOOD PRECIP
POTENTIAL IN THE HIGH TERRAIN...AND POTENTIAL FOR ISOLATED TO
SCATTERED SHOWERS ACROSS THE PLAINS AT TIMES.
ZONAL FLOW WITH A BIT OF HIGH PRESSURE RIDGING TO START THE
EXTENDED PERIOD...WILL BRING DOWNSLOPE FLOW ACROSS THE REGION
PUSHING HIGHS 5 TO 10 DEGREES ABOVE NORMAL FOR SUNDAY AND MONDAY.
THERE WILL BE A SLIGHT CHANCE FOR PRECIP IN THE HIGH TERRAIN OF
CENTRAL MONTANA AS FLOW IS FORCED UPWARD. MORE IMPORTANTLY...GUSTY
WINDS WILL BE A DAILY ISSUE AS 700MB WINDS WILL MIX DOWN TO THE
SFC...ESPECIALLY MONDAY AND TUESDAY...WITH SOME POTENTIAL 50KNOT
GUSTS APPROACHING GROUND LEVEL. A TROF AND ASSOCIATED COLD FRONT
WILL PUSH THROUGH SOUTH CENTRAL AND SOUTHEASTERN MONTANA
TUESDAY...BRINGING MUCH IMPROVED PRECIP POTENTIAL TO THE THE AREA
MOUNTAINS...AND A SLIGHT CHANCE ACROSS THE PLAINS. THIS SYSTEM
WILL ALSO BRING A STRONG PUSH OF WEST TO NORTHWEST WINDS BEHIND
THE FRONT. THIS SYSTEM WILL BRING A RETURN OF NORTHWEST FLOW
ALOFT...AND COOLER TEMPS ACROSS THE REGION. ANOTHER PACIFIC TROF
BEGINS PUSH INTO THE REGION LATE FRIDAY NIGHT...SWITCHING THE FLOW
MORE SOUTHWESTERLY...AND POINTING TOWARD ANOTHER CHANCE FOR PRECIP
ACROSS THE REGION. AAG
&&
.AVIATION...
AN AREA OF FOG THROUGH THE YELLOWSTONE RIVER VALLEY...PRODUCING
LIFR FLYING WEATHER...WILL LIFT BY 18Z. THIS WILL IMPACT KBIL.
SOUTHWEST WINDS WILL GUST TO 25KTS FROM KLVM TO KBIL BY THIS
AFTERNOON. TWH
&&
.PRELIMINARY POINT TEMP/POPS...
TDY SAT SUN MON TUE WED THU
-------------------------------------------------------
BIL 065 046/066 048/070 050/073 052/064 042/058 040/061
0/B 00/B 11/N 11/N 22/W 22/W 11/B
LVM 075 039/066 039/069 048/068 043/059 033/053 032/054
0/U 01/B 21/N 12/W 33/W 22/W 21/B
HDN 069 043/070 045/072 044/075 046/066 040/059 038/061
0/U 00/B 11/B 11/B 22/W 22/W 11/B
MLS 070 044/070 043/070 047/075 047/066 041/060 040/062
0/U 00/U 11/B 11/B 22/W 22/W 11/B
4BQ 076 045/071 043/069 046/074 048/064 041/059 039/061
0/U 00/U 10/B 00/B 22/W 22/W 11/B
BHK 068 043/067 039/066 044/072 046/063 041/057 038/060
0/U 00/N 10/B 00/B 22/W 22/W 11/N
SHR 077 045/068 040/068 042/073 044/064 037/057 035/060
0/U 00/B 10/B 00/B 23/W 32/W 21/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
612 PM CDT SAT OCT 13 2012
.AVIATION...
00Z TAFS FOR KOFK...KLNK AND KOMA.
AREA OF THUNDERSTORMS IN NORTH CENTRAL KANSAS WILL DRIFT NORTHEAST
TOWARD KLNK BETWEEN 00Z AND 06Z. MVFR/IFR CONDITIONS ARE POSSIBLE
IN THOSE THUNDERSTORMS...AND A FEW SHOWERS COULD CAUSE BRIEF MVFR
CONDITIONS AT KOMA THROUGH 06Z. OTHERWISE VFR CONDITIONS ARE
FORECAST AS A COLD FRONT SLIPS THROUGH EASTERN NEBRASKA OVERNIGHT.
WINDS WILL TURN TO THE NORTH UNDER 15KTS BEFORE 06Z. THEN
NORTHWESTWINDS WILL INCREASE INTO THE 15 TO 30 KT RANGE BY 15Z
SUNDAY AND CONTINUE THROUGH THE AFTERNOON.
DERGAN
&&
.PREV DISCUSSION... /ISSUED 318 PM CDT SAT OCT 13 2012/
SHORT TERM...TONIGHT THROUGH TUESDAY
MUCH WARMER AND MOISTER AIR HAS REACHED THE REGION AHEAD OF AN
ADVANCING UPPER-LEVEL LOW. SUBJECTIVE 12Z UPPER AIR ANALYSIS
INDICATES OPENING UPPER LOW CENTERED IN SOUTHERN CO...WITH 500MB
HEIGHT FALLS UP TO 90M IN EASTERN CO INDICATING THE WAVE IS EJECTING
INTO THE CENTRAL PLAINS. CORE OF UPPER-LEVEL JET EXTENDED FROM GULF
OF CA THROUGH WESTERN KS/NEB AND INTO CENTRAL MN...WITH STRONGER
NORTHERN STREAM JET STREAK NOSING INTO THE PACIFIC NORTHWEST. AHEAD
OF THE UPPER LOW...850MB MOISTURE HAD SPREAD NORTHWARD FROM OK/TX
INTO NEB/IA...WITH 850MB WINDS UP TO 50-60KT IN EASTERN KS/EASTERN
NEB. SURFACE LOW AT 19Z WAS CENTERED IN NORTH CENTRAL NEB...WITH
COLD FRONT LAGGING FROM SOUTHWEST NEB THROUGH WESTERN KS TO THE
OK/TX PANHANDLES. SURFACE DEWPOINTS IN EASTERN NEB/WESTERN IA ALONG
AND SOUTH OF I-80 WERE IN THE 60S.
MAIN FORECAST CONCERN IS CONVECTIVE POTENTIAL THIS EVENING...WITH
RAIN LINGERING INTO TONIGHT IN THE SOUTHEASTERN CWA. THOUGH UPPER-
LEVEL WAVE IS OPENING...IT REMAINS POTENT. RAP ANALYSIS INDICATES
MLCAPE OF 1000+ J/KG REACHING SOUTH CENTRAL NEB. DEEP-LAYER
EFFECTIVE BULK SHEAR CERTAINLY IS POTENT...AT OR ABOVE 40KT ACROSS
MOST OF SOUTHEAST NEB/SOUTHWEST IA. INTERMITTENT CLOUDS HAVE BEEN
IN PLACE ALL ACROSS THE AREA...BUT ENOUGH SUN IS BREAKING THROUGH TO
ALLOW SOME HEATING AND DESTABILIZATION. THINK CONVECTION COULD
DEVELOP IN CENTRAL KS IN THE LATE AFTN...THEN MOVE NORTHEASTWARD
INTO SOUTHEAST NEB AND EVENTUALLY SOUTHEAST IA THROUGH THE EVENING
HOURS. DO THINK THAT STORMS THAT MOVE INTO THE AREA COULD CARRY A
RISK OF HAIL...AND ALSO WIND...ESPECIALLY AS THEY ORGANIZE INTO A
LINE LATER THIS EVENING AHEAD OF THE FRONT...AS ORIENTATION OF SHEAR
VECTOR IS NEARLY PARALLEL TO FRONTAL FORCING. DO THINK TORNADO
POTENTIAL IS LIMITED BY VEERED SURFACE WIND PROFILE. STORMS SHOULD
PROGRESS ACROSS THE AREA THROUGH THE EVENING HOURS. ECMWF CONTINUES
TO HOLD ONTO A DEFORMATION-ZONE AREA OF RAIN BEHIND THE UPPER-
LOW...WITH A STRONGER LOW THAN NAM/GFS/GEM/UKMET. HELD ONTO A
SHOWER MENTION LATE TONIGHT IN THE SOUTHEAST CWA AS A NOD TO THE
STRONGER ECMWF SOLUTION.
UPPER-LEVEL SYSTEM LACKS ANY KIND OF COLD AIR PUSH BEHIND IT...AND
MILD TEMPERATURES WILL CONTINUE INTO THE WORK WEEK. TEMPS SHOULD
PEAK ON MONDAY UNDER WARM AIR ADVECTION AND LOW-LEVEL
SOUTH/SOUTHWESTERLY FLOW...WITH HIGHS LIKELY TO CRACK 80 IN PARTS OF
EASTERN NEB. A WEAK FRONTAL PASSAGE ASSOCIATED WITH A WEAK UPPER-
LEVEL WAVE WILL SKIRT THROUGH THE AREA ON TUESDAY...BRINGING MAYBE A
FEW EXTRA CLOUDS AND A SLIGHT DIP IN TEMPERATURES TO LESS ABOVE-
NORMAL READINGS.
MAYES
LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
GLOBAL MODELS ARE IN BETTER AGREEMENT TODAY IN THE LARGE SCALE FLOW
ACROSS THE CONUS FOR THE SECOND HALF OF THE WORK WEEK. MOST
OPERATIONAL AND ENSEMBLES MODELS NOW AMPLIFY A STRONG SHORTWAVE
TROUGH DIVING INTO THE CNTRL US ON WED. THIS DRIVES A STRONG COLD
FRONT THROUGH THE FA ON WED. WE WILL CONT WITH THE CHC OF SHOWERS
FOR LATE TUE NIGHT IN THE NORTH...SPREADING ACROSS A GOOD PART OF
OUR FA FOR WED. WE MAY SEE THE SHOWERS SHUT OFF FOR A TIME ON WED
NIGHT AS THE MID LEVEL DRY-SLOT WORKS THROUGH THE FORECAST AREA. BUT
THE WRAP-AROUND/DEFORMATION ZONE LOOKS TO IMPACT AT LEAST OUR
NORTHERN AND ERN FA THU AND THU NIGHT WITH CHC POPS IN THE FORECAST.
IT APPEARS THEN THAT THIS PERIOD OF THE FORECAST WILL SEE WELL BELOW
NORMAL TEMPERATURES FOR HIGHS...ESPECIALLY ON THU WHERE HIGHS MAY
NOT GET OUT OF THE MID 40S WITH BREEZY CONDITIONS. WILL LEAVE THE
LATER HALF OF FRI AND INTO SAT DRY ATTM WITH SOME MODERATION TO
TEMPERATURES.
BOUSTEAD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
947 PM EDT SAT OCT 13 2012
.SYNOPSIS...
RAIN WILL BECOME WIDESPREAD ACROSS CENTRAL NEW YORK AND MOST OF
NORTHEAST PENNSYLVANIA OVERNIGHT AS A WARM FRONT CROSSES THE
REGION. BEHIND THE WARM FRONT...A FEW SHOWERS WILL BE POSSIBLE
SUNDAY MORNING. OTHERWISE IT WILL BE WARMER WITH HIGHS IN THE 60S
TO LOWER 70S. A COLD FRONT WILL CROSS THE REGION MONDAY WITH A
CHANCE FOR MORE SHOWERS ALONG WITH A RETURN TO COOLER WEATHER.
&&
.NEAR TERM /THROUGH SUNDAY/...
RADARS SHOW RAINS INCREASING ACROSS MUCH OF CENTRAL NEW YORK IN
RESPONSE TO INCREASING ISENTROPIC LIFT AND MOISTURE ADVECTION.
THIS ISEN LIFT/MOISTURE ADVECTION WAS IN ADVANCE OF A SHORT WAVE
RIPPLING THROUGH NORTHERN ONTARIO. THIS FEATURE WAS INCREASING
UPPER CONFLUENCE TO OUR NORTHEAST ENHANCING THE THERMALLY DIRECT
JET STREAK CIRCULATION FOR NY AND PA. THIS WAS ALLOWING FOR THE
STRGR ISEN LIFT AND PRECIPITATION TO BREAK OUT. BY AROUND
9Z...THIS WAVE PASSES AND THE WAA IMPULSE WILL WEAKEN AND THE MORE
WIDESPREAD RAINS WILL TAPER TO SCATTERED SHOWERS/SPRINKLES. THIS
OCCURS AT THE SAME TIME THAT THE STRONGER UPPER LEVEL LOW AND
ASSOCIATED SURFACE CYCLONE IN THE PLAINS INTENSIFIES AND INCREASES
THE DOWNSTREAM RIDGING ALOFT OVER THE EAST. THIS WILL ALLOW THE
WARM FRONT TO EVENTUALLY PUSH NORTH OF THE REGION SUNDAY LATER IN
THE MORNING AS THE ISENTROPES WILL EASILY BE ADVECTED NORTH AND
NOT BE HELD UP BY A JET STREAK AND ASSOCIATED GEOSTROPHIC
ADJUSTMENTS.
LATEST HRRR HAD THE BEST HANDLE ON THE RADAR ECHOES AT THIS TIME IN
OHIO WHICH WAS MUCH FARTHER SOUTH THAN THE NAM...GFS...AND OTHER
CONVECTION ALLOWING HIGH RES MODELS. SINCE THIS MODEL SEEMS TO HAVE
INITIALIZED WELL AND THE PRECIP IS FARTHER S...I WENT ALONG WITH
THE IDEA OF HAVING MORE PRECIP SLIDE ACROSS NRN PA IN LINE WITH
THE LATEST HRRR LATER TONIGHT. I RAISED POPS IN NE PA FOR LATER TONIGHT
AS A RESULT.
FOR SUNDAY...WARM FRONT CLEARS REGION TO THE NORTH. ALL HIGHER
RESOLUTION MODELS PULL PRECIP NORTH OF THE WFO BGM FORECAST AREA
BY ARND 18Z. SO I HAVE SUN PM DRY AND MILD AND CUT BACK ON POPS
FROM PREVIOUS FORECAST. OTHERWISE NO MAJOR CHANGES.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
330 PM UPDATE...
STRONGEST LIFT MOVES NORTHEAST AS A WARM FRONT LIFTS INTO NNY SUNDAY.
WILL DECREASE POPS FROM SOUTHWEST TO NORTHEAST EARLY...AND
MAINTAIN CHANCE POPS THROUGH THE AFTERNOON ONLY ACROSS NORTHERN
ONEIDA COUNTY. WE WILL REMAIN BREEZY THROUGH EARLY
AFTERNOON...AGAIN WITH THE HIGHER WINDS OVER THE HIGHEST TERRAIN.
WE LOOK FAIRLY DRY THROUGH SUNDAY NIGHT WITH POPS INCREASING
TOWARD DAYBREAK MONDAY AS A COLD FRONT ENTERS THE WESTERN PART OF
THE CWA.
NOT OVERLY IMPRESSED WITH THE FRONTAL PASSAGE MONDAY AND WILL KEEP
POPS IN THE CHANCE RANGE. BY AFTERNOON MOST OF THE CWA SHOULD BE
DRY WITH THE EXCEPTION OF THE FAR SOUTHEAST AS SOME MOISTURE MOVES
UP THE COAST. A TROF MOVES THROUGH MONDAY NIGHT WITH A FEW
SHOWERS. WITH 850S IN THE 0C TO -2C RANGE TUESDAY ON A NORTHWEST
FLOW LAKE SHOWERS WILL BE AROUND BUT STRONG NVA ON THE BACKSIDE OF
THE UPPER TROF WILL LIMIT THE POTENTIAL TO JUST SLIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
330 PM UPDATE...
MAIN FEATURE OF NOTE TO WATCH DURING THIS EXTENDED PERIOD WILL BE AN
UPPER LEVEL CLOSED LOW MOVING SLOWLY EAST FROM THE MIDWEST. MODEL
TRENDS HAVE BEEN TO SLOW THIS FEATURE DOWN WITH TIME. LATEST GFS AND
12Z ECMWF INDICATE THAT THIS SYSTEM MAY NOT BRING ANY RAIN TO OUR
AREA UNTIL FRIDAY. BASED ON THIS WILL GO WITH A DRY MILD FORECAST
WEDNESDAY THROUGH THURSDAY WITH ABOVE NORMAL HIGHS MAINLY IN THE MID
TO UPPER 60S AND LOWS IN THE 40S TO LOWER 50S. WILL BRING HIGH
CHANCE POPS ACROSS THE AREA FRIDAY AND CONTINUED MILD WITH HIGHS
MAINLY IN THE 60S. THE WEEKEND LOOKS COOLER AND CONTINUED UNSETTLED
WITH A CHANCE OF SHOWERS AS THE CLOSED LOW MOVES EAST ACROSS THE
AREA.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS DOMINATED AT PRESENT ALL TAF SITES AS MID TO HIGH
LEVEL CLOUDS STREAM OVER CENTRAL NY AND NORTHEAST PA. THERE WAS
VERY DRY AIR BELOW SO EVEN THOUGH THERE WERE ECHOES ON THE RADAR...
METARS WERE ONLY REPORTING SPOTTY LIGHT RAIN. SO FOR NOW...THE
RAINS WERE COMING OUT OF A MID-DECK ARND 7 TO 10K FEET AGL. AS THE
NIGHT PROGRESSES...RAINFALL WILL CONTINUE TO STREAM IN OVERHEAD AS
MOISTURE CONTINUES TO INCREASE. THIS WILL EVENTUALLY LOWER
CEILINGS AND EVEN VSBYS AS A STEADY RAIN EVENTUALLY REACHES THE
GRND. I SEE GENERALLY BETWEEN 04Z AND 08Z THAT MOST TAF SITES REACH
MVFR. I COULD SEE KBGM GOING BRIEFLY IFR AT TIMES BETWEEN 03Z AND
07Z AND PUT IFR IN A TEMPO GROUP. CLIMO PROGRAM SUGGESTS THIS AND
SINCE KBGM IS UP AROUND 1600 FEET ABV MSL WE HAVE THE BEST SHOT AT
GETTING IFR CIGS. THERE WAS SOME IFR IN MI ATTM. SO WILL HAVE TO
WATCH HOW THIS EVOLVES TO OUR WEST NEXT FEW HOURS. CONFIDENCE IN
IFR AT KBGM IS LOW AT THIS POINT...BUT HIGH ENUF TO PUT IT IN A
TEMPO GROUP.
AFTER THE RAINS ENDS TWD SUNRISE...CIGS AND VSBYS SHUD REBOUND TO
VFR AND THEN EVENTUALLY CLOUDS LIKELY WILL LIFT ABV 10000 FEET AND
SCT OUT BY SUN AFTERNOON AS SOUTH WINDS TAKE OVER. I DON/T SEE ANY
STRONG WINDS AT THIS POINT. THERE IS ENUF OF A LOW-LEVEL INVERSION
TO KEEP THE STRONGER WINDS AT BAY ABV THE SFC TONIGHT. METARS ARE SHOWING
THIS.
OUTLOOK...
SUN NGT/MON/TUE...MVFR IN SHRA.
WED AND THU...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...HEDEN
LONG TERM...MSE
AVIATION...DJN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
755 PM EDT SAT OCT 13 2012
.SYNOPSIS...
CLOUDS WILL CONTINUE TO THICKEN OVER THE AREA THROUGH LATE EVENING
WITH RAIN DEVELOPING...FIRST ACROSS NEW YORK STATE AND EVENTUALLY
INTO NORTHERN PENNSYLVANIA AFTER MIDNIGHT. RAIN WILL REMAIN LIKELY
OVERNIGHT AS A WARM FRONT MOVES THROUGH. BEHIND THE WARM FRONT A
FEW SHOWERS WILL BE POSSIBLE ACROSS CENTRAL NEW YORK
SUNDAY...OTHERWISE IT WILL BE BREEZY AND WARM WITH HIGHS NEAR 70.
A COLD FRONT WILL CROSS THE REGION MONDAY WITH SHOWERS ALONG WITH
A RETURN TO COOLER WEATHER.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
RADARS SHOW LIGHT RETURNS ACROSS MUCH OF NORTHERN NEW YORK IN
RESPONSE TO INCREASING ISENTROPIC LIFT AND MOISTURE ADVECTION.
MUCH OF THIS WAS VIRGA AT PRESENT. THIS ISEN LIFT/MOISTURE
ADVECTION WAS IN ADVANCE OF A SHORT WAVE RIPPLING THROUGH NORTHERN
ONTARIO. THIS FEATURE WAS INCREASING UPPER CONFLUENCE TO OUR
NORTHEAST ENHANCING THE THERMALLY DIRECT JET STREAK CIRCULATION
FOR NY AND PA. THIS WAS ALLOWING FOR THE STRGR ISEN LIFT AND
PRECIPITATION TO BREAK OUT. BY AROUND 9Z...THIS WAVE PASSES AND THE
WAA IMPULSE WILL WEAKEN AND THE MORE WIDESPREAD RAINS WILL TAPER
TO SCATTERED SHOWERS/SPRINKLES. THIS OCCURS AT THE SAME TIME THAT
THE STRONGER UPPER LEVEL LOW AND ASSOCIATED SURFACE CYCLONE IN THE
PLAINS INTENSIFIES AND INCREASES THE DOWNSTREAM RIDGING ALOFT
OVER THE EAST. THIS WILL ALLOW THE WARM FRONT TO EVENTUALLY PUSH
NORTH OF THE REGION SUNDAY LATER IN THE MORNING AS THE ISENTROPES
WILL EASILY BE ADVECTED NORTH AND NOT BE HELD UP BY A JET STREAK
AND ASSOCIATED GEOSTROPHIC ADJUSTMENTS.
LATEST HRRR HAD THE BEST HANDLE ON THE RADAR ECHOES AT THIS TIME IN
OHIO WHICH WAS MUCH FARTHER SOUTH THAN THE NAM...GFS...AND OTHER
CONVECTION ALLOWING HIGH RES MODELS. SINCE THIS MODEL SEEMS TO HAVE
INITIALIZED WELL AND THE PRECIP IS FARTHER S...I WENT ALONG WITH
THE IDEA OF HAVING MORE PRECIP SLIDE ACROSS NRN PA IN LINE WITH
THE LATEST HRRR LATER TONIGHT. I RAISED POPS IN NE PA FOR LATER TONIGHT
AS A RESULT. OTHERWISE JUST SOME TWEAKS TO AN EXCELLENT FORECAST.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY NIGHT/...
330 PM UPDATE...
STRONGEST LIFT MOVES NORTHEAST AS A WARM FRONT LIFTS INTO NNY SUNDAY.
WILL DECREASE POPS FROM SOUTHWEST TO NORTHEAST EARLY...AND
MAINTAIN CHANCE POPS THROUGH THE AFTERNOON ONLY ACROSS NORTHERN
ONEIDA COUNTY. WE WILL REMAIN BREEZY THROUGH EARLY
AFTERNOON...AGAIN WITH THE HIGHER WINDS OVER THE HIGHEST TERRAIN.
WE LOOK FAIRLY DRY THROUGH SUNDAY NIGHT WITH POPS INCREASING
TOWARD DAYBREAK MONDAY AS A COLD FRONT ENTERS THE WESTERN PART OF
THE CWA.
NOT OVERLY IMPRESSED WITH THE FRONTAL PASSAGE MONDAY AND WILL KEEP
POPS IN THE CHANCE RANGE. BY AFTERNOON MOST OF THE CWA SHOULD BE
DRY WITH THE EXCEPTION OF THE FAR SOUTHEAST AS SOME MOISTURE MOVES
UP THE COAST. A TROF MOVES THROUGH MONDAY NIGHT WITH A FEW
SHOWERS. WITH 850S IN THE 0C TO -2C RANGE TUESDAY ON A NORTHWEST
FLOW LAKE SHOWERS WILL BE AROUND BUT STRONG NVA ON THE BACKSIDE OF
THE UPPER TROF WILL LIMIT THE POTENTIAL TO JUST SLIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
330 PM UPDATE...
MAIN FEATURE OF NOTE TO WATCH DURING THIS EXTENDED PERIOD WILL BE AN
UPPER LEVEL CLOSED LOW MOVING SLOWLY EAST FROM THE MIDWEST. MODEL
TRENDS HAVE BEEN TO SLOW THIS FEATURE DOWN WITH TIME. LATEST GFS AND
12Z ECMWF INDICATE THAT THIS SYSTEM MAY NOT BRING ANY RAIN TO OUR
AREA UNTIL FRIDAY. BASED ON THIS WILL GO WITH A DRY MILD FORECAST
WEDNESDAY THROUGH THURSDAY WITH ABOVE NORMAL HIGHS MAINLY IN THE MID
TO UPPER 60S AND LOWS IN THE 40S TO LOWER 50S. WILL BRING HIGH
CHANCE POPS ACROSS THE AREA FRIDAY AND CONTINUED MILD WITH HIGHS
MAINLY IN THE 60S. THE WEEKEND LOOKS COOLER AND CONTINUED UNSETTLED
WITH A CHANCE OF SHOWERS AS THE CLOSED LOW MOVES EAST ACROSS THE
AREA.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS DOMINATED AT PRESENT ALL TAF SITES AS MID TO HIGH
LEVEL CLOUDS STREAM OVER CENTRAL NY AND NORTHEAST PA. THERE WAS
VERY DRY AIR BELOW SO EVEN THOUGH THERE WERE ECHOES ON THE RADAR...
METARS WERE ONLY REPORTING SPOTTY LIGHT RAIN. SO FOR NOW...THE
RAINS WERE COMING OUT OF A MID-DECK ARND 7 TO 10K FEET AGL. AS THE
NIGHT PROGRESSES...RAINFALL WILL CONTINUE TO STREAM IN OVERHEAD AS
MOISTURE CONTINUES TO INCREASE. THIS WILL EVENTUALLY LOWER
CEILINGS AND EVEN VSBYS AS A STEADY RAIN EVENTUALLY REACHES THE
GRND. I SEE GENERALLY BETWEEN 04Z AND 08Z THAT MOST TAF SITES REACH
MVFR. I COULD SEE KBGM GOING BRIEFLY IFR AT TIMES BETWEEN 03Z AND
07Z AND PUT IFR IN A TEMPO GROUP. CLIMO PROGRAM SUGGESTS THIS AND
SINCE KBGM IS UP AROUND 1600 FEET ABV MSL WE HAVE THE BEST SHOT AT
GETTING IFR CIGS. THERE WAS SOME IFR IN MI ATTM. SO WILL HAVE TO
WATCH HOW THIS EVOLVES TO OUR WEST NEXT FEW HOURS. CONFIDENCE IN
IFR AT KBGM IS LOW AT THIS POINT...BUT HIGH ENUF TO PUT IT IN A
TEMPO GROUP.
AFTER THE RAINS ENDS TWD SUNRISE...CIGS AND VSBYS SHUD REBOUND TO
VFR AND THEN EVENTUALLY CLOUDS LIKELY WILL LIFT ABV 10000 FEET AND
SCT OUT BY SUN AFTERNOON AS SOUTH WINDS TAKE OVER. I DON/T SEE ANY
STRONG WINDS AT THIS POINT. THERE IS ENUF OF A LOW-LEVEL INVERSION
TO KEEP THE STRONGER WINDS AT BAY ABV THE SFC TONIGHT. METARS ARE SHOWING
THIS.
OUTLOOK...
SUN NGT/MON/TUE...MVFR IN SHRA.
WED AND THU...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...HEDEN
LONG TERM...MSE
AVIATION...DJN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
301 AM EDT FRI OCT 12 2012
.SYNOPSIS...
A COLD FRONT WILL DROP SOUTHEAST TONIGHT...AND BRING A CHANCE FOR
RAIN SHOWERS...MAINLY OVER CENTRAL NEW YORK. HIGH PRESSURE WILL
BUILD INTO THE REGION BEHIND THIS FRONT ON FRIDAY...AND BRING
CLEAR SKIES AND COLD AIR FRIDAY NIGHT ENDING THE GROWING SEASON.
DRY AND MILDER CONDITIONS ARE EXPECTED ON SATURDAY. THE NEXT
CHANCE FOR SHOWERS WILL COME SATURDAY NIGHT AND SUNDAY AS A WARM
FRONT MOVES THROUGH THE REGION.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
10 PM UPDATE...
FNT AND ASSOCIATED PCPN SEEMS TO BE HOLDING UP A BIT JUST NORTH OF
THE FCST AREA...AWAITING THE WV MVG THRU THE CNTRL LAKES. XPCT THE
FNT AND PCPN TO BEGIN TO MVE SEWRD ONCE AGAIN LTR TNGT AS THE WV
APRCHS. HRRR SEEMS TO HAVE A GOOD HANDLE ON THE ADVANCE OF THE
PCPN SHIELD. FCSTD TEMPS IN GOOD SHAPE...JUST SOME MINOR
ADJUSTMENTS FOR THE UNEQUAL COOLING OF THE HILLS AND VLYS IN THE
AREA. TWEEKED THE MINS DOWN JUST A BIT...CLSR IN LINE WITH THE
BLENDED MOS GUID. PRVS DISC CONTS BLO.
CDFNT WILL DROP SEWD TNGT WITH A BAND OF CLDS AND -SHRA. THE
-SHRA MAY DIMINISH AS THE FNT HEADS INTO E PA TWDS DAYBREAK...AND
WE`VE KEPT THE HIEST POPS ACRS CNTRL NY TNGT (LOW LIKELY/HI CHC
POPS). TNGT`S FCST MINS INDICATE BEST POTNL FOR ISOLD FROST WILL
ACRS THE CATSKILLS AND PORTIONS OF THE POCONOS WHERE CLDS WILL BE
LATER TO MOV IN...BUT TEMPS ARE MARGINAL AND WITH CLD DECK FCST TO
MOV IN LATER TNGT THINK POTNL IS MARGINAL (IN ADDN...MUCH COLDER
TEMPS ARE IN THE CARDS FOR FRI NGT). WE LEANED TWDS THE WARMER
SIDE OF GDNC FOR TNGT`S MINS GIVEN EXPECTATION OF SOME WIND AND
XPCTD INCRS IN CLD CVR LATER TNGT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
RESIDUAL MSTR BEHIND THE FNT..AIDED BY LAKE ONTARIO...IS XPCTD TO
PERSIST TMRW MRNG ACRS CNTRL NY...WITH MAYBE A FEW -SHRA. WE CAN`T
TOTALLY RULE OUT A FEW FLAKES MIXING IN OVER THE HIEST TRRN TMRW
MRNG BUT IT LOOKS VERY MARGINAL AND THEREFORE WON`T ADD TO THE WX
GRIDS.
STRONG DEEP SUBSIDENCE BEHIND THE FNT VERY EVIDENT IN THE OMEGA
T-H XSXNS AFTER 18Z WHICH WILL HELP ERODE/DSPT THE CLD CVR. THERE
COULD BE A FEW STRAY CLDS ACRS OUR FAR NW/NRN ZONES...BUT ALL IN
ALL AN XCLNT RADIATIONAL COOLING SITUATION WILL SET UP. ISSUED A
FROST WATCH FOR FRI NGT AS IT APEARS THIS WILL BE THE END OF THE
GROWING SEASON.
THE HIGH MOVS OFFSHORE ALLOWING A SW FLOW TO DVLP ON SAT. WE`LL
LIKELY SEE AN INCRS IN MID/UPR CLDS SAT AFTN IN ADVANCE OF THE NXT
S/WV. NON-DIURNAL TEMP TRENDS...OR STEADY TEMPS APPEAR LIKELY SAT
NGT IN ADVANCE OF THE WMFNT MAINLY ALONG THE LAKE PLAIN DUE TO
INCRSNG SW FLOW ON SAT NGT. XPCT SHRA TO OVERSPREAD THE RGN AS THE
WMFNT APRCHS...WITH THE BEST CHCS ACRS CNTRL AND NRN ZONES WHERE
ISEN LIFT IS STRONGEST.
THE WMFNT RAINS SHUD LIFT NWD ON SUNDAY MRNG...AND WOULD NOT BE
SUPRISED TO SEE MOST OF THE CWA REMAIN DRY ON SUNDAY...BUT WE LEFT
LOW CHC POPS IN FOR SUNDAY AFTN FOR CONSISTENCY. 925 TEMPS ON SUNDAY
ACRS THE FINGER LAKES AND CNTRL SRN TIER WOULD SUPPORT MAXES WELL
INTO THE U70S WE HAD FULL SUN...BUT IT APPEARS THAT AT A MINIMUM
WE`LL HAVE A BKN-OVC MID/UPR DECK WHICH WILL TEMPER MAXES. SO
STAYED CLOSE TO MOS GDNC WITH MAXES APRCHNG 70 WRN ZONES...WITH
MAXES IN THE L60S FAR SE ZONES.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
3 AM UPDATE...CURRENT 00Z MEDIUM RANGE MODEL GUIDANCE REMAINS
CONSISTENT WITH PREVIOUS RUNS. CURRENT FORECAST IN GOOD SHAPE WITH
NO SIGNIFICANT CHANGES NEEDED.
PREVIOUS DISC...
2 PM UPDATE...LONG TERM GUIDANCE REMAINS IN GOOD AGREEMENT THAT
THE BEST SHOT AT PRECIPITATION WILL COME EARLY MONDAY WITH A COLD
FRONT. DRIER AIR WILL BUILD IN BEHIND THE FRONT MONDAY BUT WILL
MAINTAIN CHANCE POPS DURING THE DAY...ESPECIALLY UP NORTH...WITH
AN H5 TROF STILL MOVING THROUGH.
WEAK RIDING BUILDS IN TUESDAY AND WEDNESDAY AND WITH A DEVELOPING
SOUTHERLY FLOW...WE WILL ONCE AGAIN TURN MILD. HIGHS BY WEDNESDAY
LOOK TO BE BACK INTO THE 60S AS 850 TEMPS CLIMB TOWARD +6C ON THE
0Z EURO. WITH THE NEW 12Z GFS NUMBERS COMING IN CLOSER TO +10...WE
MAY EVEN BE A TAD TOO COOL RIGHT NOW IN OUR GRIDS. NEXT SHOT AT
RAIN COMES THURSDAY WITH THE NEXT FRONT.
&&
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
A COLD FRONT CURRENTLY DROPPING SOUTH FROM LAKE ONTARIO WILL PASS
THROUGH THE TERMINALS EARLY THIS MORNING. OCCASIONAL MVFR SHOWERS
DUE TO CIGS WILL OCCUR NEAR THIS BOUNDARY. AT KRME/KSYR ACTIVITY
WILL OCCUR BETWEEN 08Z-12Z, FOR KITH/KBGM/KELM BETWEEN 09Z-14Z AND
AT KAVP BETWEEN 13-15Z. AT KITH/KBGM, MVFR CIGS WILL PREVAIL
DURING THIS PERIOD WITH OCCASIONAL LOW MVFR CIGS. BY LATE MORNING
SHOWERS WILL END BUT A BROKEN STRATO CU DECK AROUND 4K FT WILL
PERSIST UNTIL MID/LATE AFTERNOON WHEN SKIES WILL SCATTER OUT THEN
CLEAR FOR THE OVERNIGHT PERIOD.
SOUTHWEST WINDS AROUND 10 KNOTS BECOMING NORTHWEST WITH FROPA
AROUND 10 KNOTS THEN INCREASING LATER THIS MORNING TO 12-15 KNOTS
WITH GUSTS 20-25 KNOTS. WINDS WILL DIMINISH LATE THIS AFTERNOON
THEN BECOME LIGHT OVERNIGHT.
OUTLOOK...
SAT/SUN...VFR.
SUN NGT/MON...MVFR IN SHRA.
TUE...VFR.
&&
.CLIMATE...
NEAR RECORD LOW TEMPERATURES POSSIBLE SATURDAY MORNING OCTOBER
13TH. A COLD HIGH PRESSURE SYSTEM IS EXPECTED TO COVER THE REGION
BY SATURDAY MORNING AND COULD BRING WIDESPREAD FROST AND FREEZING
CONDITIONS TO THE REGION. RECORD LOWS THAT COULD BE CHALLENGED ARE
AS FOLLOWS: RECORD (YEAR) SAT AM FORECAST LOW
GREATER BINGHAMTON AIRPORT 28 (1993) 27
SCRANTON/WILKES BARRE AIRPORT 29 (1993) 28
SYRACUSE AIRPORT 29 (2006) 28
ITHACA AIRPORT 25 (1964) 26
ELMIRA/CORNING AIRPORT 25 (1951) 24
ROME/GRIFFIS AIRPORT 26 (1993) 26
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...FREEZE WATCH FROM THIS EVENING THROUGH SATURDAY MORNING FOR
PAZ038>040-043-044-047-048-072.
NY...FREEZE WATCH FROM THIS EVENING THROUGH SATURDAY MORNING FOR
NYZ009-015>018-022>025-036-037-044>046-055>057-062.
&&
$$
SYNOPSIS...
NEAR TERM...DGM
SHORT TERM...
LONG TERM...HEDEN/RRM
AVIATION...RRM
CLIMATE...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
144 AM EDT FRI OCT 12 2012
.SYNOPSIS...
A COLD FRONT WILL DROP SOUTHEAST TONIGHT...AND BRING A CHANCE FOR
RAIN SHOWERS...MAINLY OVER CENTRAL NEW YORK. HIGH PRESSURE WILL
BUILD INTO THE REGION BEHIND THIS FRONT ON FRIDAY...AND BRING
CLEAR SKIES AND COLD AIR FRIDAY NIGHT ENDING THE GROWING SEASON.
DRY AND MILDER CONDITIONS ARE EXPECTED ON SATURDAY. THE NEXT
CHANCE FOR SHOWERS WILL COME SATURDAY NIGHT AND SUNDAY AS A WARM
FRONT MOVES THROUGH THE REGION.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
10 PM UPDATE...
FNT AND ASSOCIATED PCPN SEEMS TO BE HOLDING UP A BIT JUST NORTH OF
THE FCST AREA...AWAITING THE WV MVG THRU THE CNTRL LAKES. XPCT THE
FNT AND PCPN TO BEGIN TO MVE SEWRD ONCE AGAIN LTR TNGT AS THE WV
APRCHS. HRRR SEEMS TO HAVE A GOOD HANDLE ON THE ADVANCE OF THE
PCPN SHIELD. FCSTD TEMPS IN GOOD SHAPE...JUST SOME MINOR
ADJUSTMENTS FOR THE UNEQUAL COOLING OF THE HILLS AND VLYS IN THE
AREA. TWEEKED THE MINS DOWN JUST A BIT...CLSR IN LINE WITH THE
BLENDED MOS GUID. PRVS DISC CONTS BLO.
CDFNT WILL DROP SEWD TNGT WITH A BAND OF CLDS AND -SHRA. THE
-SHRA MAY DIMINISH AS THE FNT HEADS INTO E PA TWDS DAYBREAK...AND
WE`VE KEPT THE HIEST POPS ACRS CNTRL NY TNGT (LOW LIKELY/HI CHC
POPS). TNGT`S FCST MINS INDICATE BEST POTNL FOR ISOLD FROST WILL
ACRS THE CATSKILLS AND PORTIONS OF THE POCONOS WHERE CLDS WILL BE
LATER TO MOV IN...BUT TEMPS ARE MARGINAL AND WITH CLD DECK FCST TO
MOV IN LATER TNGT THINK POTNL IS MARGINAL (IN ADDN...MUCH COLDER
TEMPS ARE IN THE CARDS FOR FRI NGT). WE LEANED TWDS THE WARMER
SIDE OF GDNC FOR TNGT`S MINS GIVEN EXPECTATION OF SOME WIND AND
XPCTD INCRS IN CLD CVR LATER TNGT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY/...
RESIDUAL MSTR BEHIND THE FNT..AIDED BY LAKE ONTARIO...IS XPCTD TO
PERSIST TMRW MRNG ACRS CNTRL NY...WITH MAYBE A FEW -SHRA. WE CAN`T
TOTALLY RULE OUT A FEW FLAKES MIXING IN OVER THE HIEST TRRN TMRW
MRNG BUT IT LOOKS VERY MARGINAL AND THEREFORE WON`T ADD TO THE WX
GRIDS.
STRONG DEEP SUBSIDENCE BEHIND THE FNT VERY EVIDENT IN THE OMEGA
T-H XSXNS AFTER 18Z WHICH WILL HELP ERODE/DSPT THE CLD CVR. THERE
COULD BE A FEW STRAY CLDS ACRS OUR FAR NW/NRN ZONES...BUT ALL IN
ALL AN XCLNT RADIATIONAL COOLING SITUATION WILL SET UP. ISSUED A
FROST WATCH FOR FRI NGT AS IT APEARS THIS WILL BE THE END OF THE
GROWING SEASON.
THE HIGH MOVS OFFSHORE ALLOWING A SW FLOW TO DVLP ON SAT. WE`LL
LIKELY SEE AN INCRS IN MID/UPR CLDS SAT AFTN IN ADVANCE OF THE NXT
S/WV. NON-DIURNAL TEMP TRENDS...OR STEADY TEMPS APPEAR LIKELY SAT
NGT IN ADVANCE OF THE WMFNT MAINLY ALONG THE LAKE PLAIN DUE TO
INCRSNG SW FLOW ON SAT NGT. XPCT SHRA TO OVERSPREAD THE RGN AS THE
WMFNT APRCHS...WITH THE BEST CHCS ACRS CNTRL AND NRN ZONES WHERE
ISEN LIFT IS STRONGEST.
THE WMFNT RAINS SHUD LIFT NWD ON SUNDAY MRNG...AND WOULD NOT BE
SUPRISED TO SEE MOST OF THE CWA REMAIN DRY ON SUNDAY...BUT WE LEFT
LOW CHC POPS IN FOR SUNDAY AFTN FOR CONSISTENCY. 925 TEMPS ON SUNDAY
ACRS THE FINGER LAKES AND CNTRL SRN TIER WOULD SUPPORT MAXES WELL
INTO THE U70S WE HAD FULL SUN...BUT IT APPEARS THAT AT A MINIMUM
WE`LL HAVE A BKN-OVC MID/UPR DECK WHICH WILL TEMPER MAXES. SO
STAYED CLOSE TO MOS GDNC WITH MAXES APRCHNG 70 WRN ZONES...WITH
MAXES IN THE L60S FAR SE ZONES.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
2 PM UPDATE...LONG TERM GUIDANCE REMAINS IN GOOD AGREEMENT THAT
THE BEST SHOT AT PRECIPITATION WILL COME SUNDAY NIGHT INTO EARLY
MONDAY WITH A COLD FRONT. TEMPS WILL BE MILD SUNDAY NIGHT AHEAD OF
THE FRONT...WITH 40S TO LOWER 50S EXPECTED. DRIER AIR WILL BUILD
IN BEHIND THE FRONT MONDAY BUT WILL MAINTAIN CHANCE POPS DURING
THE DAY...ESPECIALLY UP NORTH...WITH AN H5 TROF STILL MOVING THROUGH.
WEAK RIDING BUILDS IN TUESDAY AND WEDNESDAY AND WITH A DEVELOPING
SOUTHERLY FLOW...WE WILL ONCE AGAIN TURN MILD. HIGHS BY WEDNESDAY
LOOK TO BE BACK INTO THE 60S AS 850 TEMPS CLIMB TOWARD +6C ON THE
0Z EURO. WITH THE NEW 12Z GFS NUMBERS COMING IN CLOSER TO +10...WE
MAY EVEN BE A TAD TOO COOL RIGHT NOW IN OUR GRIDS. NEXT SHOT AT
RAIN COMES THURSDAY WITH THE NEXT FRONT.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
A COLD FRONT CURRENTLY DROPPING SOUTH FROM LAKE ONTARIO WILL PASS
THROUGH THE TERMINALS EARLY THIS MORNING. OCCASIONAL MVFR SHOWERS
DUE TO CIGS WILL OCCUR NEAR THIS BOUNDARY. AT KRME/KSYR ACTIVITY
WILL OCCUR BETWEEN 08Z-12Z, FOR KITH/KBGM/KELM BETWEEN 09Z-14Z AND
AT KAVP BETWEEN 13-15Z. AT KITH/KBGM, MVFR CIGS WILL PREVAIL
DURING THIS PERIOD WITH OCCASIONAL LOW MVFR CIGS. BY LATE MORNING
SHOWERS WILL END BUT A BROKEN STRATO CU DECK AROUND 4K FT WILL
PERSIST UNTIL MID/LATE AFTERNOON WHEN SKIES WILL SCATTER OUT THEN
CLEAR FOR THE OVERNIGHT PERIOD.
SOUTHWEST WINDS AROUND 10 KNOTS BECOMING NORTHWEST WITH FROPA
AROUND 10 KNOTS THEN INCREASING LATER THIS MORNING TO 12-15 KNOTS
WITH GUSTS 20-25 KNOTS. WINDS WILL DIMINISH LATE THIS AFTERNOON
THEN BECOME LIGHT OVERNIGHT.
OUTLOOK...
SAT/SUN...VFR.
SUN NGT/MON...MVFR IN SHRA.
TUE...VFR.
&&
.CLIMATE...
NEAR RECORD LOW TEMPERATURES POSSIBLE SATURDAY MORNING OCTOBER
13TH. A COLD HIGH PRESSURE SYSTEM IS EXPECTED TO COVER THE REGION
BY SATURDAY MORNING AND COULD BRING WIDESPREAD FROST AND FREEZING
CONDITIONS TO THE REGION. RECORD LOWS THAT COULD BE CHALLENGED ARE
AS FOLLOWS: RECORD (YEAR) SAT AM FORECAST LOW
GREATER BINGHAMTON AIRPORT 28 (1993) 27
SCRANTON/WILKES BARRE AIRPORT 29 (1993) 28
SYRACUSE AIRPORT 29 (2006) 28
ITHACA AIRPORT 25 (1964) 26
ELMIRA/CORNING AIRPORT 25 (1951) 24
ROME/GRIFFIS AIRPORT 26 (1993) 26
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...FREEZE WATCH FROM THIS EVENING THROUGH SATURDAY MORNING FOR
PAZ038>040-043-044-047-048-072.
NY...FREEZE WATCH FROM THIS EVENING THROUGH SATURDAY MORNING FOR
NYZ009-015>018-022>025-036-037-044>046-055>057-062.
&&
$$
SYNOPSIS...
NEAR TERM...DGM
SHORT TERM...
LONG TERM...HEDEN
AVIATION...RRM
CLIMATE...
AREA FORECAST DISCUSSION
NWS NORMAN OK
1030 PM CDT SAT OCT 13 2012
.AVIATION...
PRECIP AND CLOUD COVER HAS CLEARED TAF SITES THIS EVENING. SKIES
SHOULD REMAIN CLEAR THROUGH THE NEXT 24HRS. WEST WINDS WILL BECOME
NORTHWEST OVERNIGHT AND INCREASE SUNDAY MORNING WITH 25KT GUST
EXPECTED AT SITES BY MID-MORNING. WINDS WILL DIMINISH QUICKLY AROUND
SUNSET TOMORROW.
30
&&
.PREV DISCUSSION... /ISSUED 915 PM CDT SAT OCT 13 2012/
.UPDATE...
PRECIP CONTINUES TO PUSH EAST AND SOUTHEAST OUT OF THE AREA THIS
EVENING. WILL SEND AN UPDATE TO DEAL WITH PRECIP CHANCES ENDING
ACROSS PORTIONS OF THE AREA.
&&
.PREV DISCUSSION... /ISSUED 642 PM CDT SAT OCT 13 2012/
DISCUSSION...
AVIATION DISCUSSION FOR THE 00Z TAFS IS BELOW.
AVIATION...
MVFR CONDITIONS ARE POSSIBLE NEAR AND EAST OF KPNC-KSPS
THROUGH 04Z...THEN HAVE HIGH CONFIDENCE VFR CONDITIONS
WILL PREVAIL.
ADDED MVFR CEILING MENTION NEAR KOKC...KSPS...KOUN...AND KPNC
THROUGH 02 OR 03Z WHERE CONFIDENCE OF OCCURRENCE IS MODERATE.
KLAW MAY BE BRIEFLY AFFECTED AS WELL...THOUGH CONFIDENCE IS TOO
LOW TO MENTION.
BELIEVE MOST...IF NOT ALL...TSRA WILL BE EAST OF THE
TAF SITES BY 00Z. KOUN MAY BE THE ONLY EXCEPTION.
GUSTY WINDS SHOULD QUICKLY SUBSIDE BY 02Z.
WINDS WILL SHIFT TO A NORTHERLY DIRECTION 03-10Z.
MBS
PREV DISCUSSION... /ISSUED 345 PM CDT SAT OCT 13 2012/
.SEVERE THUNDERSTORMS EXPECTED THROUGH 1 AM CDT TONIGHT
SOUTHEAST OF A CHEROKEE TO QUANAH LINE...
DISCUSSION...
THE MAIN CONCERN IS ONGOING SEVERE THUNDERSTORMS.
CURRENT STORMS NEAR A SEYMOUR TO EL RENO LINE HAVE DEVELOPED JUST
AHEAD AND EAST OF THE DRYLINE. GENERALLY THINK THESE STORMS WILL
CONGEAL INTO ONE MAIN LINE BY 7 PM CDT NEAR AN ARCHER CITY TO ADA
LINE AND QUICKLY MOVE EAST...LIKELY EXITING ATOKA AND BRYAN
COUNTIES BY 1 AM CDT. THINK THE LATEST HRRR RUNS HANDLE THIS
WELL.
THE MAIN HAZARD IS DAMAGING WINDS UP TO 70 MPH...ESPECIALLY ONCE
STORMS FORM INTO ONE MAIN LINE. A COLD POOL OF AIR SEEMS TO BE
DEVELOPING WITH THE LINE OF STORMS FROM FREDERICK TO EL RENO
WHICH WILL ONLY GET STRONGER OVER THE NEXT FEW HOURS. NOT TO
MENTION...FORCING FROM THE APPROACHING MID/UPPER LOW/TROUGH OVER
WESTERN KANSAS AND THE PANHANDLES WILL ALLOW THE LINE OF STORMS
TO GROW AND PERHAPS ACCELERATE OVER THE NEXT SEVERAL HOURS.
THERE IS A POTENTIAL FOR TORNADOES AND LARGE HAIL UP TO GOLF
BALLS WITH DISCRETE SUPERCELLS AHEAD OF THE MAIN DEVELOPING
LINE...WHICH APPEARS TO BE MOST LIKELY SOUTHEAST OF A KNOX
CITY TO OKLAHOMA CITY TO CHANDLER LINE. LOW LCLS WITH SURFACE
DEWPOINTS AROUND 70 DEGREES...50-100 J/KG 0-3KM MLCAPE...AND
0-1 KM SRH 150 TO 300 M2/S2 SUPPORT LOW LEVEL ROTATING
SUPERCELLS. ANY SUPERCELLS WILL MOVE NORTHEAST AROUND
50 MPH.
ALL SEVERE STORMS WILL END BY 1 AM CDT TONIGHT.
BEYOND TONIGHT...GENERALLY DRY AND QUIET WEATHER WILL
PREVAIL. DID NOT CHANGE ANYTHING BEYOND SUNDAY.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 52 80 53 83 / 10 0 0 0
HOBART OK 51 82 51 82 / 10 0 0 0
WICHITA FALLS TX 55 83 54 86 / 10 0 0 0
GAGE OK 48 81 43 86 / 10 0 0 0
PONCA CITY OK 53 79 48 81 / 10 0 0 0
DURANT OK 60 82 54 84 / 80 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
03/30
AREA FORECAST DISCUSSION
NWS NORMAN OK
915 PM CDT SAT OCT 13 2012
.UPDATE...
PRECIP CONTINUES TO PUSH EAST AND SOUTHEAST OUT OF THE AREA THIS
EVENING. WILL SEND AN UPDATE TO DEAL WITH PRECIP CHANCES ENDING
ACROSS PORTIONS OF THE AREA.
&&
.PREV DISCUSSION... /ISSUED 642 PM CDT SAT OCT 13 2012/
DISCUSSION...
AVIATION DISCUSSION FOR THE 00Z TAFS IS BELOW.
AVIATION...
MVFR CONDITIONS ARE POSSIBLE NEAR AND EAST OF KPNC-KSPS
THROUGH 04Z...THEN HAVE HIGH CONFIDENCE VFR CONDITIONS
WILL PREVAIL.
ADDED MVFR CEILING MENTION NEAR KOKC...KSPS...KOUN...AND KPNC
THROUGH 02 OR 03Z WHERE CONFIDENCE OF OCCURRENCE IS MODERATE.
KLAW MAY BE BRIEFLY AFFECTED AS WELL...THOUGH CONFIDENCE IS TOO
LOW TO MENTION.
BELIEVE MOST...IF NOT ALL...TSRA WILL BE EAST OF THE
TAF SITES BY 00Z. KOUN MAY BE THE ONLY EXCEPTION.
GUSTY WINDS SHOULD QUICKLY SUBSIDE BY 02Z.
WINDS WILL SHIFT TO A NORTHERLY DIRECTION 03-10Z.
MBS
PREV DISCUSSION... /ISSUED 345 PM CDT SAT OCT 13 2012/
.SEVERE THUNDERSTORMS EXPECTED THROUGH 1 AM CDT TONIGHT
SOUTHEAST OF A CHEROKEE TO QUANAH LINE...
DISCUSSION...
THE MAIN CONCERN IS ONGOING SEVERE THUNDERSTORMS.
CURRENT STORMS NEAR A SEYMOUR TO EL RENO LINE HAVE DEVELOPED JUST
AHEAD AND EAST OF THE DRYLINE. GENERALLY THINK THESE STORMS WILL
CONGEAL INTO ONE MAIN LINE BY 7 PM CDT NEAR AN ARCHER CITY TO ADA
LINE AND QUICKLY MOVE EAST...LIKELY EXITING ATOKA AND BRYAN
COUNTIES BY 1 AM CDT. THINK THE LATEST HRRR RUNS HANDLE THIS
WELL.
THE MAIN HAZARD IS DAMAGING WINDS UP TO 70 MPH...ESPECIALLY ONCE
STORMS FORM INTO ONE MAIN LINE. A COLD POOL OF AIR SEEMS TO BE
DEVELOPING WITH THE LINE OF STORMS FROM FREDERICK TO EL RENO
WHICH WILL ONLY GET STRONGER OVER THE NEXT FEW HOURS. NOT TO
MENTION...FORCING FROM THE APPROACHING MID/UPPER LOW/TROUGH OVER
WESTERN KANSAS AND THE PANHANDLES WILL ALLOW THE LINE OF STORMS
TO GROW AND PERHAPS ACCELERATE OVER THE NEXT SEVERAL HOURS.
THERE IS A POTENTIAL FOR TORNADOES AND LARGE HAIL UP TO GOLF
BALLS WITH DISCRETE SUPERCELLS AHEAD OF THE MAIN DEVELOPING
LINE...WHICH APPEARS TO BE MOST LIKELY SOUTHEAST OF A KNOX
CITY TO OKLAHOMA CITY TO CHANDLER LINE. LOW LCLS WITH SURFACE
DEWPOINTS AROUND 70 DEGREES...50-100 J/KG 0-3KM MLCAPE...AND
0-1 KM SRH 150 TO 300 M2/S2 SUPPORT LOW LEVEL ROTATING
SUPERCELLS. ANY SUPERCELLS WILL MOVE NORTHEAST AROUND
50 MPH.
ALL SEVERE STORMS WILL END BY 1 AM CDT TONIGHT.
BEYOND TONIGHT...GENERALLY DRY AND QUIET WEATHER WILL
PREVAIL. DID NOT CHANGE ANYTHING BEYOND SUNDAY.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 52 80 53 83 / 10 0 0 0
HOBART OK 51 82 51 82 / 10 0 0 0
WICHITA FALLS TX 55 83 54 86 / 10 0 0 0
GAGE OK 48 81 43 86 / 10 0 0 0
PONCA CITY OK 53 79 48 81 / 10 0 0 0
DURANT OK 60 82 54 84 / 80 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
03/30
AREA FORECAST DISCUSSION
NWS NORMAN OK
642 PM CDT SAT OCT 13 2012
.DISCUSSION...
AVIATION DISCUSSION FOR THE 00Z TAFS IS BELOW.
&&
.AVIATION...
MVFR CONDITIONS ARE POSSIBLE NEAR AND EAST OF KPNC-KSPS
THROUGH 04Z...THEN HAVE HIGH CONFIDENCE VFR CONDITIONS
WILL PREVAIL.
ADDED MVFR CEILING MENTION NEAR KOKC...KSPS...KOUN...AND KPNC
THROUGH 02 OR 03Z WHERE CONFIDENCE OF OCCURRENCE IS MODERATE.
KLAW MAY BE BRIEFLY AFFECTED AS WELL...THOUGH CONFIDENCE IS TOO
LOW TO MENTION.
BELIEVE MOST...IF NOT ALL...TSRA WILL BE EAST OF THE
TAF SITES BY 00Z. KOUN MAY BE THE ONLY EXCEPTION.
GUSTY WINDS SHOULD QUICKLY SUBSIDE BY 02Z.
WINDS WILL SHIFT TO A NORTHERLY DIRECTION 03-10Z.
MBS
&&
.PREV DISCUSSION... /ISSUED 345 PM CDT SAT OCT 13 2012/
..SEVERE THUNDERSTORMS EXPECTED THROUGH 1 AM CDT TONIGHT
SOUTHEAST OF A CHEROKEE TO QUANAH LINE...
DISCUSSION...
THE MAIN CONCERN IS ONGOING SEVERE THUNDERSTORMS.
CURRENT STORMS NEAR A SEYMOUR TO EL RENO LINE HAVE DEVELOPED JUST
AHEAD AND EAST OF THE DRYLINE. GENERALLY THINK THESE STORMS WILL
CONGEAL INTO ONE MAIN LINE BY 7 PM CDT NEAR AN ARCHER CITY TO ADA
LINE AND QUICKLY MOVE EAST...LIKELY EXITING ATOKA AND BRYAN
COUNTIES BY 1 AM CDT. THINK THE LATEST HRRR RUNS HANDLE THIS
WELL.
THE MAIN HAZARD IS DAMAGING WINDS UP TO 70 MPH...ESPECIALLY ONCE
STORMS FORM INTO ONE MAIN LINE. A COLD POOL OF AIR SEEMS TO BE
DEVELOPING WITH THE LINE OF STORMS FROM FREDERICK TO EL RENO
WHICH WILL ONLY GET STRONGER OVER THE NEXT FEW HOURS. NOT TO
MENTION...FORCING FROM THE APPROACHING MID/UPPER LOW/TROUGH OVER
WESTERN KANSAS AND THE PANHANDLES WILL ALLOW THE LINE OF STORMS
TO GROW AND PERHAPS ACCELERATE OVER THE NEXT SEVERAL HOURS.
THERE IS A POTENTIAL FOR TORNADOES AND LARGE HAIL UP TO GOLF
BALLS WITH DISCRETE SUPERCELLS AHEAD OF THE MAIN DEVELOPING
LINE...WHICH APPEARS TO BE MOST LIKELY SOUTHEAST OF A KNOX
CITY TO OKLAHOMA CITY TO CHANDLER LINE. LOW LCLS WITH SURFACE
DEWPOINTS AROUND 70 DEGREES...50-100 J/KG 0-3KM MLCAPE...AND
0-1 KM SRH 150 TO 300 M2/S2 SUPPORT LOW LEVEL ROTATING
SUPERCELLS. ANY SUPERCELLS WILL MOVE NORTHEAST AROUND
50 MPH.
ALL SEVERE STORMS WILL END BY 1 AM CDT TONIGHT.
BEYOND TONIGHT...GENERALLY DRY AND QUIET WEATHER WILL
PREVAIL. DID NOT CHANGE ANYTHING BEYOND SUNDAY.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 52 80 53 83 / 70 0 0 0
HOBART OK 51 82 51 82 / 10 0 0 0
WICHITA FALLS TX 55 83 54 86 / 70 0 0 0
GAGE OK 48 81 43 86 / 10 0 0 0
PONCA CITY OK 53 79 48 81 / 40 0 0 0
DURANT OK 60 82 54 84 / 100 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
17
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
805 PM EDT SAT OCT 13 2012
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTHWARD THROUGH THE STATE TONIGHT. SUNDAY
WILL BE MUCH WARMER THAN NORMAL...THEN A COLD FRONT WILL PASS
THROUGH SUNDAY NIGHT OR MONDAY. MOST OF THE UPCOMING WEEK THEN
LOOKS DRY WITH HIGH PRESSURE MOVING IN FROM THE WEST.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
THICKENING CIRRUS SHIELD BLANKETING WESTERN AND CENTRAL PORTIONS
OF THE CWA EARLY THIS EVENING...WHILE SKIES REMAINED GENERALLY
CLEAR ACROSS THE LOWER SUSQ VALLEY.
THE LEADING EDGE OF AN AREA OF SHOWERS ACROSS NERN OHIO AND
CENTRAL LAKE ERIE WAS MOVING QUICKLY TO THE EAST AT AROUND 30 KTS
AND SPREAD ACROSS THE NW MTNS BETWEEN 01-02Z. A BLEND OF THE HRRR
AND RUC INDICATES THAT THE SHOWERS WILL FALL IN MOST LOCATIONS TO
THE NORTH OF INTERSTATE 80/ROUTE 220 BETWEEN 04-09Z AND HAVE
RAISED POPS ACCORDINGLY. PWAT AND 850 MB WIND ANOMALIES IN THE
NORTH ARE BOTH 2-3 ST DEVIATIONS ABOVE NORMAL.
SOME MARGINAL ELEVATED INSTABILITY BASED AT AROUND 850 MB WILL
SLIDE INTO THE NW MTNS AFTER 08Z SUNDAY INVOF THE SRN EDGE OF SOME
HEFTY WSW WINDS OF 55-60 KTS AT THAT LEVEL. A FEW RUMBLES OF
THUNDER ARE POSSIBLE INVOF OF KBFD VERY LATE TONIGHT.
POPS WILL BE NIL NEAR AND TO THE SOUTH OF THE ROUTE 22/322
CORRIDOR ACROSS SCENT AND SERN PENN WITH JUST VARYING AMOUNTS AND
THICKNESS OF MID AND HIGH CLOUDS.
THE PASSING SHORT WAVE AND NOSE OF THE WSW LLJET MAX WILL BE
OVERHEAD OR EVEN OFF TO THE EAST BY SUNRISE...AND EXPECT TO SEE
SHOWERS RETREAT TO MAINLY THE NRN TIER COUNTIES OF PENN.
THE TEMP CURVE WILL BE VERY FLAT OVERNIGHT AS A 5-15KT SOUTHERLY
BREEZE CONTINUES AND DEWPOINTS SLOWLY CREEP UP INTO THE LOWER 40S
IN MOST AREAS BY DAYBREAK. LOWS TEMPS WILL BE MAINLY IN THE LOWER
40S...EXCEPT PERHAPS ACROSS THE HIGHER TERRAIN OF WESTERN PENN
WHERE A GREATER SOUTHERLY BREEZE AND INCREASING LATE NIGHT PWAT
AIR COULD KEEP TEMPS FROM FALLING BELOW 45F. THESE MINS WILL BE
NEAR NORMAL IN THE SE...WHERE THE WINDS WILL BE LIGHTER...AND
5-10F ABOVE NORMALS IN THE WEST.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
AFTER ANY VERY EARLY MORNING SHRA LEFT OVER IN THE N...THE DAY
WILL TURN OUT VERY WARM AND MAINLY DRY. WE WILL BE IN THE WARM
SECTOR...SO WE WOULD NEED SOME FORCING TO POP ANY SHOWERS...AND
THERE SEEMS TO BE NONE. WILL HOLD JUST A TINY POP IN THE NORTH IN
THE EARLY MORNING AND A TINY POP IN THE WESTERN MOUNTAINS DUE TO
UNCERTAINTY OF TIMING ARRIVAL OF ANY SHOWERS FROM THE WEST IN THE
EVENING. SOME TALLER CU MIGHT ALSO BUILD UP IN THE AFTN IN THE
WEST...BUT HARDLY WORTH MENTIONING ANY POPS THERE EITHER.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
SHOWERS IMPINGE ON MAINLY WESTERN HALF SUN NIGHT AS N-S FRONTAL
BOUNDARY PASSES THROUGH LATE...WEAKENING AS IT DOES. HIGHEST POPS
ACROSS THE WEST...WITH QPF OF JUST A TENTH OR TWO. WITH FROPA
COMING SO LATE...TEMPS WILL REMAIN QUITE MILD SUN NIGHT...WITH
LOWS ONLY IN THE 50S FOR MOST.
COLDER AIR DOES ARRIVE ON MON WITH A BREEZY WEST WIND...WITH MAX
TEMPS ACROSS THE WEST A SOLID 10-15F LOWER THAN SUNDAY. HIGHS IN
THE EAST WILL MAX OUT A BIT BELOW PREVIOUS DAY...BUT COOLER AIR
WILL WORK IN AS DAY WEARS ON AND TEMPS WILL LIKELY FALL BACK A BIT
IN THE AFTERNOON.
WEAK HIGH PRESSURE RIDGE RETURNS FOR MIDWEEK...BRINGING DRY
WEATHER WITH COOL MORNINGS. TUE WILL SEE SLIGHTLY BELOW NORMAL
HIGHS...BUT RETURN FLOW ON BACK SIDE OF HIGH WILL PUSH TEMPS
SLIGHTLY ABOVE NORMAL BY THU.
TROUGH EDGES TOWARD PA FOR NEXT WEEKEND. MODELS NOT IN VERY GOOD
AGREEMENT ON EVOLUTION/TIMING/STRENGTH OF THIS FEATURE AS IT
IMPACTS PA LATER FRI INTO SUN. GFS IS WEAKER AND MOST
PROGRESSIVE...BRINGING RAIN CHANCES IN EARLIER IN THE WEEKEND
FOLLOWED BY COOLER AIR...WHILE ECMWF TRIES TO SPIN UP A
LARGER/SLOWER UPPER LOW WHICH WOULD DELAY PRECIP AND COLDER AIR.
TRYING TO FIND SOME TANGIBLE AGREEMENT...WHICH REVEALS ITSELF IN
POP FIELDS...AS BOTH SEEM TO INTEGRATE A WAVE SLIDING ACROSS PA
WITH THE WARM FRONT FRI-FRI NIGHT BRINGING BEST CHANCE FOR RAIN.
SO PLAYED IT THAT WAY...WITH CONTINUING LOWER CHANCES INTO THE
WEEKEND.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
VFR CONDS EXPECTED THROUGH MOST OF THE TAF PERIOD. EXPECT LIGHT TO
MODERATE SOUTHERLY WINDS FOR THE HIGHER ELEVATIONS THROUGH THE
NIGHT...AND LIGHT TO CALM WINDS IN THE VALLEYS. HOWEVER...MODERATE
TO STRONG SRLY WINDS ABOVE THE SFC WILL LEAD TO WIDESPREAD LOW
LEVEL WIND SHEAR OVERNIGHT AT MOST AIRFIELDS.
SIGNIFICANT MOISTURE WILL BE POOLED WELL TO OUR NORTH ALONG A WARM
FRONT...BUT ENOUGH OF A SHORT WAVE TROUGH MOVES THROUGH THAT SHOULD
BRING SCATTERED SHOWERS TONIGHT AND VERY EARLY SUNDAY MORNING TO
THE NRN TIER. WILL ONLY MENTION AT KBFD FOR NOW...WITH VERY LOW
CONFIDENCE IN ANY SHOWERS FOR ANY OF THE OTHER TERMINALS. MVFR
CIG/VSBY ARE POSSIBLE AT BFD AND IPT THROUGH THE NIGHT...BUT IFR
UNLIKELY. THEN VFR CONDITIONS SHOULD PREVAIL THROUGH THE DAYLIGHT
ON SUNDAY AS WE GET INTO THE WARM SECTOR AND FORCING OF ANY REPUTE
WAITS UNTIL SUNDAY NIGHT TO MOVE IN FROM THE WEST. A COLD FRONT
WILL NEAR SUNDAY NIGHT AND PASS THROUGH BY/ON MONDAY. THE PASSAGE
LOOKS MAINLY DRY BUT REDUCTIONS IN CIGS/VSBYS ARE POSSIBLE...ESP
W.
OUTLOOK...
TUE...MVFR CIGS W.
WED-THUR...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...DANGELO/LAMBERT
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
717 PM EDT SAT OCT 13 2012
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTHWARD THROUGH THE STATE TONIGHT. SUNDAY
WILL BE MUCH WARMER THAN NORMAL...THEN A COLD FRONT WILL PASS
THROUGH SUNDAY NIGHT OR MONDAY. MOST OF THE UPCOMING WEEK THEN
LOOKS DRY WITH HIGH PRESSURE MOVING IN FROM THE WEST.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
THICKENING CIRRUS SHIELD BLANKETING WESTERN AND CENTRAL PORTIONS
OF THE CWA EARLY THIS EVENING...WHILE SKIES REMAINED GENERALLY
CLEAR ACROSS THE LOWER SUSQ VALLEY.
THE LEADING EDGE OF AN AREA OF SHOWERS ACROSS NERN OHIO AND
CENTRAL LAKE ERIE WAS MOVING QUICKLY TO THE EAST AT AROUND 30 KTS
AND SPREAD ACROSS THE NW MTNS BETWEEN 01-02Z. A BLEND OF THE HRRR
AND RUC INDICATES THAT THE SHOWERS WILL FALL IN MOST LOCATIONS TO
THE NORTH OF INTERSTATE 80/ROUTE 220 BETWEEN 04-09Z AND HAVE
RAISED POPS ACCORDINGLY. PWAT AND 850 MB WIND ANOMALIES IN THE
NORTH ARE BOTH 2-3 ST DEVIATIONS ABOVE NORMAL.
SOME MARGINAL ELEVATED INSTABILITY BASED AT AROUND 850 MB WILL
SLIDE INTO THE NW MTNS AFTER 08Z SUNDAY INVOF THE SRN EDGE OF SOME
HEFTY WSW WINDS OF 55-60 KTS AT THAT LEVEL. A FEW RUMBLES OF
THUNDER ARE POSSIBLE INVOF OF KBFD VERY LATE TONIGHT.
POPS WILL BE NIL NEAR AND TO THE SOUTH OF THE ROUTE 22/322
CORRIDOR ACROSS SCENT AND SERN PENN WITH JUST VARYING AMOUNTS AND
THICKNESS OF MID AND HIGH CLOUDS.
THE PASSING SHORT WAVE AND NOSE OF THE WSW LLJET MAX WILL BE
OVERHEAD OR EVEN OFF TO THE EAST BY SUNRISE...AND EXPECT TO SEE
SHOWERS RETREAT TO MAINLY THE NRN TIER COUNTIES OF PENN.
THE TEMP CURVE WILL BE VERY FLAT OVERNIGHT AS A 5-15KT SOUTHERLY
BREEZE CONTINUES AND DEWPOINTS SLOWLY CREEP UP INTO THE LOWER 40S
IN MOST AREAS BY DAYBREAK. LOWS TEMPS WILL BE MAINLY IN THE LOWER
40S...EXCEPT PERHAPS ACROSS THE HIGHER TERRAIN OF WESTERN PENN
WHERE A GREATER SOUTHERLY BREEZE AND INCREASING LATE NIGHT PWAT
AIR COULD KEEP TEMPS FROM FALLING BELOW 45F. THESE MINS WILL BE
NEAR NORMAL IN THE SE...WHERE THE WINDS WILL BE LIGHTER...AND
5-10F ABOVE NORMALS IN THE WEST.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
AFTER ANY VERY EARLY MORNING SHRA LEFT OVER IN THE N...THE DAY
WILL TURN OUT VERY WARM AND MAINLY DRY. WE WILL BE IN THE WARM
SECTOR...SO WE WOULD NEED SOME FORCING TO POP ANY SHOWERS...AND
THERE SEEMS TO BE NONE. WILL HOLD JUST A TINY POP IN THE NORTH IN
THE EARLY MORNING AND A TINY POP IN THE WESTERN MOUNTAINS DUE TO
UNCERTAINTY OF TIMING ARRIVAL OF ANY SHOWERS FROM THE WEST IN THE
EVENING. SOME TALLER CU MIGHT ALSO BUILD UP IN THE AFTN IN THE
WEST...BUT HARDLY WORTH MENTIONING ANY POPS THERE EITHER.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
SHOWERS IMPINGE ON MAINLY WESTERN HALF SUN NIGHT AS N-S FRONTAL
BOUNDARY PASSES THROUGH LATE...WEAKENING AS IT DOES. HIGHEST POPS
ACROSS THE WEST...WITH QPF OF JUST A TENTH OR TWO. WITH FROPA
COMING SO LATE...TEMPS WILL REMAIN QUITE MILD SUN NIGHT...WITH
LOWS ONLY IN THE 50S FOR MOST.
COLDER AIR DOES ARRIVE ON MON WITH A BREEZY WEST WIND...WITH MAX
TEMPS ACROSS THE WEST A SOLID 10-15F LOWER THAN SUNDAY. HIGHS IN
THE EAST WILL MAX OUT A BIT BELOW PREVIOUS DAY...BUT COOLER AIR
WILL WORK IN AS DAY WEARS ON AND TEMPS WILL LIKELY FALL BACK A BIT
IN THE AFTERNOON.
WEAK HIGH PRESSURE RIDGE RETURNS FOR MIDWEEK...BRINGING DRY
WEATHER WITH COOL MORNINGS. TUE WILL SEE SLIGHTLY BELOW NORMAL
HIGHS...BUT RETURN FLOW ON BACK SIDE OF HIGH WILL PUSH TEMPS
SLIGHTLY ABOVE NORMAL BY THU.
TROUGH EDGES TOWARD PA FOR NEXT WEEKEND. MODELS NOT IN VERY GOOD
AGREEMENT ON EVOLUTION/TIMING/STRENGTH OF THIS FEATURE AS IT
IMPACTS PA LATER FRI INTO SUN. GFS IS WEAKER AND MOST
PROGRESSIVE...BRINGING RAIN CHANCES IN EARLIER IN THE WEEKEND
FOLLOWED BY COOLER AIR...WHILE ECMWF TRIES TO SPIN UP A
LARGER/SLOWER UPPER LOW WHICH WOULD DELAY PRECIP AND COLDER AIR.
TRYING TO FIND SOME TANGIBLE AGREEMENT...WHICH REVEALS ITSELF IN
POP FIELDS...AS BOTH SEEM TO INTEGRATE A WAVE SLIDING ACROSS PA
WITH THE WARM FRONT FRI-FRI NIGHT BRINGING BEST CHANCE FOR RAIN.
SO PLAYED IT THAT WAY...WITH CONTINUING LOWER CHANCES INTO THE
WEEKEND.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
VFR CONDS EXPECTED THROUGH MOST OF THE TAF PERIOD. EXPECT LIGHT TO
MODERATE SOUTHERLY WINDS FOR THE HIGHER ELEVATIONS THROUGH THE
NIGHT...BUT THE VALLEYS SHOULD DECOUPLE SOMEWHAT. SIGNIFICANT
MOISTURE WILL BE POOLED WELL TO OUR NORTH BUT ENOUGH OF A SHORT
WAVE TROUGH MOVES THROUGH THAT IT SHOULD BRING SCATTERED SHOWERS
TONIGHT AND VERY EARLY SUNDAY MORNING TO THE NRN TIER. WILL ONLY
MENTION AT KBFD FOR NOW...WITH VERY LOW CONFIDENCE IN ANY SHOWERS
FOR ANY OF THE OTHER TERMINALS. MVFR CIG/VSBY ARE POSSIBLE AT BFD
AND IPT THROUGH THE NIGHT...BUT IFR UNLIKELY. THEN VFR CONDITIONS
SHOULD PREVAIL THROUGH THE DAYLIGHT ON SUNDAY AS WE GET INTO THE
WARM SECTOR AND FORCING OF ANY REPUTE WAITS UNTIL SUNDAY NIGHT TO
MOVE IN FROM THE WEST. A COLD FRONT WILL NEAR SUNDAY NIGHT AND
PASS THROUGH BY/ON MONDAY. THE PASSAGE LOOKS MAINLY DRY BUT
REDUCTIONS IN CIGS/VSBYS ARE POSSIBLE...ESP W.
OUTLOOK...
TUE...MVFR CIGS W.
WED-THUR...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...DANGELO/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
352 AM EDT FRI OCT 12 2012
.SYNOPSIS...
A COLD FRONT WILL SWEEP THROUGH THE STATE EARLY TODAY. A MASSIVE
ANTICYCLONE WILL PRODUCE CLEAR CALM CONDITIONS FOR A WIDESPREAD
FROST SATURDAY. A MOISTURE PLUME AND WARMER AIR COULD BRING
SHOWERS SATURDAY NIGHT INTO SUNDAY.
A TROUGH OVER THE EASTERN UNITED STATES NEXT WEEK WILL SET UP TO
OUR WEST. A RELATIVELY DRY AND SEASONABLY WARM PERIOD OF WEATHER
IS EXPECTED FOR MOST OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
SATELLITE IMAGERY...IR AND 11-3.9 MICRON SHOW CLOUDS OVER
NORTHWESTERN PA. THE FIRST SURGES INTO WEST CENTRAL AREAS HAVE
DISSIPATED. MOST OF CENTRAL AND SOUTHERN PA ARE SPOT ON CLEAR.
THE CLEAR AREAS WITH DEW POINTS IN THE LOWER 30S HAVE PRODUCED
SOME REMARKABLE TEMPERATURE GRADIENTS. READINGS IN THE UPPER 20S
LOWER 30S. INCREDIBLE RANGE 29 IN PARTS OF CAMBRIA COUNTY AND 31
IN PARTS OF BLAIR COUNTY. MUCH COLDER THAN THE REGIONAL AIRPORTS.
WHERE KJST IS 39 AND KAOO IS 43 AND 44 AT KUNV. SOME PASSING
CLOUDS KEPT SOUTHERN AREAS IN 40S. TEMPERATURES SHOULD BEGIN TO
REBOUND IN EXTREME NORTHWEST WHERE CLOUDS MOVING IN.
THE RURAL NON-AIRPORT OBS REFLECT PATCHY FROST IN RURAL AREAS.
KCLE AND KBUF SHOW VERY LITTLE PRECIPITATION TO OUR WEST. 4KM NAM
AND HRRR ARE NOT VERY AGGRESSIVE WITH RAINFALL EITHER. LOWERED POPS
IN EARLY AM IN NW TO CHANCE.
THE 4KM NAM AT 0000 UTC AND RECENT 0,1,2, 3 UTC RAP DATA IMPLY
SHOWERS IN THE 10-12Z RANGE IN NW PA. BUT THE WEAK SHOWERS SEEM TO
FALL APART AS THEY MOVE INTO THE DRY AIR TO THE SOUTH AND EAST.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM SATURDAY/...
THE COLD FRONT WILL PUSH SOUTH ACROSS THE REGION BTWN 09Z-16Z WITH
THE CHANCE OF SOME LINGERING SHOWERS DURING THE FIRST PART OF THE
MORNING...ESPECIALLY OVER THE NWRN HALF OR SO OF THE STATE.
FRONTAL TIMING IS GOOD WITH THE 13KM RAP.
SHORT RANGE MODELS AGREE IN QUICKLY MOVING THE SFC HIGH AND LOW
PWAT AIR OVERHEAD BY AFTN...WHICH SHOULD BRING CLEARING SKIES.
ENSEMBLE MEAN 850 TEMPS ARE SUPPORTIVE OF HIGH TEMPS FROM JUST THE
M40S OVER THE N MTNS...TO THE U50S ACROSS THE LOWER SUSQ VALLEY. A
FAIRLY TIGHT PRES GRADIENT BEHIND FRONT WILL RESULT IN A BREEZY
DAY. BUFKIT SOUNDINGS SUPPORT FREQUENT GUSTS TO ARND 20KT BY AFTN.
RAP AND MOST GUIDANCE SUGGEST HIGHS RANGE FROM LOWER 40S NW TO
AROUND 60 EXTREME SOUTHEAST.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
SATURDAY SHOULD GET OFF TO A FROSTY START BUT WITH THE FLOW AROUND
THE RETREATING ANTICYCLONE LATE AFTERNOON TEMPERATURES SHOULD
REBOUND NICELY TO NEAR NORMAL. THE PW SURGE TO OUR WEST SHOULD
INCREASE OUR CLOUDS. BUT SHOULD BE A DRY DAY.
THE WARM AIR...ABOUT +1.5 SIGMA ABOVE NORMAL MOVES OVER SATURDAY
NIGHT INTO LATE SUNDAY...ALONG WITH A SURGE OF ABOVE NORMAL PW
IMPLYING A GOOD CHANCE AT RAIN OVERNIGHT SATURDAY OR INTO SUNDAY
AM. THIS IS THE BEST MOISTURE PLUME FOR THE NEXT 6-7 DAYS. IF WE
GET RAIN THIS SHOULD BE OUR BEST OF SOME RAINFALL. THE HIGH PW AIR
AND IMPLIED MOISTURE WILL KEEP TEMPERATURES UP SATURDAY NIGHT.
SUNDAY HAS A GOOD CHANCE OF RAIN IN THE NORTH THOUGH POPS NOT
IMPRESSIVE IN MOS...BETTER IN GEFS.
A WEAK COLD FRONT COULD TRIGGER SHOWERS MONDAY AS THE LAST OF THE
HIGH PW AIR IS PUSHED EAST BY A MORE N-S FRONT.
OUR PW VALUES STAY CLOSE TO NORMAL WHICH TYPICALLY MEANS LOW
CHANCE OF SIGNIFICANT RAINFALL. THE 850 HPA TEMPERATURES TOO ARE
NEAR NORMAL. ANY RAINFALL POTENTIAL WOULD BE LOW AND AMOUNTS
SCANT. THERE ARE IMPLIED WEAK FRONTAL BOUNDARIES IN THE ENSEMBLES
BUT NOTHING OF NOTE. TEMPERATURES SHOULD BE NEAR NORMAL WITH BELOW
NORMAL RAINFALL MOST OF THE WEEK. AT THIS TIME A TROUGH COULD
TRIGGER LIGHT SHOWERS THURS-FRI. BUT THIS WILL LIKELY CHANGE AS
VERY HIGH UNCERTAINTY.
INTERESTING TO WATCH SURGE OF HIGH PW WELL OFF THE ATLANTIC COAST AND
THE DEEP LOW PRESSURE IN THE GUIDANCE WITH THE LATE SEASON
TROPICAL STORM PATTY. NICE ATMOSPHERIC RIVER WHICH SHOULD STAY
WELL OUT TO SEA.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE MOVING EAST ACROSS THE STATE WILL KEEP THE REGION
VFR OVERNIGHT AND FRIDAY.
A COLD FRONT WILL MOVE IN FROM THE NORTH EARLY THIS MORNING AND
COULD PRODUCE SOME SHOWERS AND REDUCED CIGS/VSBYS OVER THE NWRN
MOUNTAINS /KBFD/ FRIDAY MORNING...BUT WIDESPREAD REDUCTIONS ARE
NOT EXPECTED AS THE FRONT WILL NOT BE ESPECIALLY STRONG.
LIGHT...GENERALLY SWRLY WINDS THROUGH THE OVERNIGHT PERIOD WILL TURN
NWRLY BEHIND THE FRONT DURING THE DAY ON FRIDAY...WITH GUSTS OF 15
TO 25MPH EXPECTED AT MOST AIRFIELDS.
OUTLOOK...
SAT...NO SIG WX.
SUN...VFR...BUT MVFR POSSIBLE IN SCATTERED SHOWERS.
MON...MAINLY VFR...SOME LOWER CONDITIONS POSSIBLE WITH A COLD
FRONT AND SCATTERED SHOWERS.
TUE...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR
PAZ010>012-017>019-025>028-034>037-041-045-046-049>053-056>059-
063>066.
&&
$$
SYNOPSIS...GRUMM
NEAR TERM...GRUMM/FITZGERALD
SHORT TERM...GRUMM/FITZGERALD
LONG TERM...GRUMM/MARTIN
AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
219 AM EDT FRI OCT 12 2012
.SYNOPSIS...
A COLD FRONT WILL SWEEP THROUGH THE STATE EARLY TODAY. A MASSIVE
ANTICYCLONE WILL PRODUCE CLEAR CALM CONDITIONS FOR A WIDESPREAD
FROST SATURDAY. A MOISTURE PLUME AND WARMER AIR COULD BRING
SHOWERS SATURDAY NIGHT INTO SUNDAY.
A TROUGH OVER THE EASTERN UNITED STATES NEXT WEEK WILL SET UP TO
OUR WEST. A RELATIVELY DRY AND SEASONABLY WARM PERIOD OF WEATHER
IS EXPECTED FOR MOST OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
SATELLITE IMAGERY...IR AND 11-3.9 MICRON SHOW CLOUDS OVER
NORTHWESTERN PA. THE FIRST SURGES INTO WEST CENTRAL AREAS HAVE
DISSIPATED. MOST OF CENTRAL AND SOUTHERN PA ARE SPOT ON CLEAR.
THE CLEAR AREAS WITH DEW POINTS IN THE LOWER 30S HAVE PRODUCED
SOME REMARKABLE TEMPERATURE GRADIENTS. READINGS IN THE UPPER 20S
LOWER 30S. INCREDIBLE RANGE 29 IN PARTS OF CAMBRIA COUNTY AND 31
IN PARTS OF BLAIR COUNTY. MUCH COLDER THAN THE REGIONAL AIRPORTS.
WHERE KJST IS 39 AND KAOO IS 43 AND 44 AT KUNV. SOME PASSING
CLOUDS KEPT SOUTHERN AREAS IN 40S. TEMPERATURES SHOULD BEGIN TO
REBOUND IN EXTREME NORTHWEST WHERE CLOUDS MOVING IN.
THE RURAL NON-AIRPORT OBS REFLECT PATCHY FROST IN RURAL AREAS.
KCLE AND KBUF SHOW VERY LITTLE PRECIPITATION TO OUR WEST. 4KM NAM
AND HRRR ARE NOT VERY AGGRESSIVE WITH RAINFALL EITHER. LOWERED POPS
IN EARLY AM IN NW TO CHANCE.
THE 4KM NAM AT 0000 UTC AND RECENT 0,1,2, 3 UTC RAP DATA IMPLY
SHOWERS IN THE 10-12Z RANGE IN NW PA. BUT THE WEAK SHOWERS SEEM TO
FALL APART AS THEY MOVE INTO THE DRY AIR TO THE SOUTH AND EAST.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM SATURDAY/...
THE COLD FRONT WILL PUSH SOUTH ACROSS THE REGION BTWN 09Z-16Z WITH
THE CHANCE OF SOME LINGERING SHOWERS DURING THE FIRST PART OF THE
MORNING...ESPECIALLY OVER THE NWRN HALF OR SO OF THE STATE.
FRONTAL TIMING IS GOOD WITH THE 13KM RAP.
SHORT RANGE MODELS AGREE IN QUICKLY MOVING THE SFC HIGH AND LOW
PWAT AIR OVERHEAD BY AFTN...WHICH SHOULD BRING CLEARING SKIES.
ENSEMBLE MEAN 850 TEMPS ARE SUPPORTIVE OF HIGH TEMPS FROM JUST THE
M40S OVER THE N MTNS...TO THE U50S ACROSS THE LOWER SUSQ VALLEY. A
FAIRLY TIGHT PRES GRADIENT BEHIND FRONT WILL RESULT IN A BREEZY
DAY. BUFKIT SOUNDINGS SUPPORT FREQUENT GUSTS TO ARND 20KT BY AFTN.
RAP AND MOST GUIDANCE SUGGEST HIGHS RANGE FROM LOWER 40S NW TO
AROUND 60 EXTREME SOUTHEAST.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
NOT MUCH CHANGE FROM RECENT DAYS.
FRIDAY NIGHT LIKELY TO RESULT IN WIDESPREAD FROST...FREEZE
ISSUES...AS A SPRAWLING 1032 MB HIGH PRESSURE BECOMES CENTERED
RIGHT OVER CENTRAL PENN BY 12Z SATURDAY. CLEAR SKIES...LIGHT WINDS...
LOW PW VALUES...AND INVERSION WILL ALLOW TEMPS TO DROP QUICKLY.
EXPANDED THE FREEZE WATCH TO COVER THE LOWER SUSQUEHANNA VLY...
EVEN IF MDT DOES NOT FREEZE...MOST AREAS WILL...AND EVEN THOSE
SPOTS THAT STAY A DEGREE OR TWO ABOVE FREEZING...WILL SEE SOME
FROST.
A MODERATING TREND IS IN STORE FOR SAT...BUT THE REAL MILD TEMPS
WILL ARRIVE SUNDAY INTO MONDAY...AS A STRONG LOW LIFTS NE ACROSS
THE LAKES. TEMPS WILL SPRING BACK INTO THE 60S. 850 MB TEMPS OVER
12 DEGREES C...AND A STRONG SW FLOW...WOULD SUPPORT TEMPS WELL
INTO THE 70S.
SOME SHOWERS ARE POSSIBLE WITH A WARM FRONT SATURDAY NIGHT AND
MORE SHOWERS WITH COLD FRONT LATER SUNDAY INTO MONDAY...HIGHEST
CHC ACROSS THE FAR NORTH. OVERALL...MUCH OF THE TIME WILL BE ON
THE DRY SIDE.
SLIGHTLY COOLER FOR LATER MONDAY INTO WED. SOME CHC OF SHOWERS
BY LATE THU. 12Z GFS HAS UPPER LVL TROUGH GOING NEGATIVE...
THUS SHOWERS MAY BE SLOW TO MOVE OUT.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE MOVING EAST ACROSS THE STATE WILL KEEP THE REGION
VFR OVERNIGHT AND FRIDAY.
A COLD FRONT WILL MOVE IN FROM THE NORTH EARLY THIS MORNING AND
COULD PRODUCE SOME SHOWERS AND REDUCED CIGS/VSBYS OVER THE NWRN
MOUNTAINS /KBFD/ FRIDAY MORNING...BUT WIDESPREAD REDUCTIONS ARE
NOT EXPECTED AS THE FRONT WILL NOT BE ESPECIALLY STRONG.
LIGHT...GENERALLY SWRLY WINDS THROUGH THE OVERNIGHT PERIOD WILL TURN
NWRLY BEHIND THE FRONT DURING THE DAY ON FRIDAY...WITH GUSTS OF 15
TO 25MPH EXPECTED AT MOST AIRFIELDS.
OUTLOOK...
SAT...NO SIG WX.
SUN...VFR...BUT MVFR POSSIBLE IN SCATTERED SHOWERS.
MON...MAINLY VFR...SOME LOWER CONDITIONS POSSIBLE WITH A COLD
FRONT AND SCATTERED SHOWERS.
TUE...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR
PAZ010>012-017>019-025>028-034>037-041-045-046-049>053-056>059-
063>066.
&&
$$
SYNOPSIS...GRUMM
NEAR TERM...GRUMM/FITZGERALD
SHORT TERM...GRUMM/FITZGERALD
LONG TERM...MARTIN
AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
158 AM EDT FRI OCT 12 2012
.SYNOPSIS...
A COLD FRONT...NEAR THE NORTH SHORE OF LAKE ERIE THIS EVENING...WILL
PUSH THROUGH CENTRAL PENNSYLVANIA FRIDAY MORNING.
A LARGE...COLD AREA OF HIGH PRESSURE WILL BUILD IN FRIDAY NIGHT
FROM THE NORTHERN PLAINS AND BECOME CENTERED OVER THE COMMONWEALTH
AROUND DAYBREAK SATURDAY...BRINGING THE THREAT OF A WIDESPREAD
FROST AND FREEZE TO THE AREA.
THE HIGH WILL MOVE OFF THE MID ATLANTIC COAST BY SUNDAY ALLOWING A
SOUTHWEST FLOW OF MILDER AIR TO RETURN TO THE REGION.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
SATELLITE IMAGERY...IR AND 11-3.9 MICRON SHOW CLOUDS OVER
NORTHWESTERN PA. THE FIRST SURGES INTO WEST CENTRAL AREAS HAVE
DISSIPATED. MOST OF CENTRAL AND SOUTHERN PA ARE SPOT ON CLEAR.
THE CLEAR AREAS WITH DEW POINTS IN THE LOWER 30S HAVE PRODUCED
SOME REMARKABLE TEMPERATURE GRADIENTS. READINGS IN THE UPPER 20S
LOWER 30S. INCREDIBLE RANGE 29 IN PARTS OF CAMBRIA COUNTY AND 31
IN PARTS OF BLAIR COUNTY. MUCH COLDER THAN THE REGIONAL AIRPORTS.
WHERE KJST IS 39 AND KAOO IS 43 AND 44 AT KUNV. SOME PASSING
CLOUDS KEPT SOUTHERN AREAS IN 40S. TEMPERATURES SHOULD BEGIN TO
REBOUND IN EXTREME NORTHWEST WHERE CLOUDS MOVING IN.
THE RURAL NON-AIRPORT OBS REFLECT PATCHY FROST IN RURAL AREAS.
KCLE AND KBUF SHOW VERY LITTLE PRECIPITATION TO OUR WEST. 4KM NAM
AND HRRR ARE NOT VERY AGGRESSIVE WITH RAINFALL EITHER. LOWERED POPS
IN EARLY AM IN NW TO CHANCE.
THE 4KM NAM AT 0000 UTC AND RECENT 0,1,2, 3 UTC RAP DATA IMPLY
SHOWERS IN THE 10-12Z RANGE IN NW PA. BUT THE WEAK SHOWERS SEEM TO
FALL APART AS THEY MOVE INTO THE DRY AIR TO THE SOUTH AND EAST.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM SATURDAY/...
THE COLD FRONT WILL PUSH SOUTH ACROSS THE REGION BTWN 09Z-16Z WITH
THE CHANCE OF SOME LINGERING SHOWERS DURING THE FIRST PART OF THE
MORNING...ESPECIALLY OVER THE NWRN HALF OR SO OF THE STATE.
FRONTAL TIMING IS GOOD WITH THE 13KM RAP.
SHORT RANGE MODELS AGREE IN QUICKLY MOVING THE SFC HIGH AND LOW
PWAT AIR OVERHEAD BY AFTN...WHICH SHOULD BRING CLEARING SKIES.
ENSEMBLE MEAN 850 TEMPS ARE SUPPORTIVE OF HIGH TEMPS FROM JUST THE
M40S OVER THE N MTNS...TO THE U50S ACROSS THE LOWER SUSQ VALLEY. A
FAIRLY TIGHT PRES GRADIENT BEHIND FRONT WILL RESULT IN A BREEZY
DAY. BUFKIT SOUNDINGS SUPPORT FREQUENT GUSTS TO ARND 20KT BY AFTN.
RAP AND MOST GUIDANCE SUGGEST HIGHS RANGE FROM LOWER 40S NW TO
AROUND 60 EXTREME SOUTHEAST.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
NOT MUCH CHANGE FROM RECENT DAYS.
FRIDAY NIGHT LIKELY TO RESULT IN WIDESPREAD FROST...FREEZE
ISSUES...AS A SPRAWLING 1032 MB HIGH PRESSURE BECOMES CENTERED
RIGHT OVER CENTRAL PENN BY 12Z SATURDAY. CLEAR SKIES...LIGHT WINDS...
LOW PW VALUES...AND INVERSION WILL ALLOW TEMPS TO DROP QUICKLY.
EXPANDED THE FREEZE WATCH TO COVER THE LOWER SUSQUEHANNA VLY...
EVEN IF MDT DOES NOT FREEZE...MOST AREAS WILL...AND EVEN THOSE
SPOTS THAT STAY A DEGREE OR TWO ABOVE FREEZING...WILL SEE SOME
FROST.
A MODERATING TREND IS IN STORE FOR SAT...BUT THE REAL MILD TEMPS
WILL ARRIVE SUNDAY INTO MONDAY...AS A STRONG LOW LIFTS NE ACROSS
THE LAKES. TEMPS WILL SPRING BACK INTO THE 60S. 850 MB TEMPS OVER
12 DEGREES C...AND A STRONG SW FLOW...WOULD SUPPORT TEMPS WELL
INTO THE 70S.
SOME SHOWERS ARE POSSIBLE WITH A WARM FRONT SATURDAY NIGHT AND
MORE SHOWERS WITH COLD FRONT LATER SUNDAY INTO MONDAY...HIGHEST
CHC ACROSS THE FAR NORTH. OVERALL...MUCH OF THE TIME WILL BE ON
THE DRY SIDE.
SLIGHTLY COOLER FOR LATER MONDAY INTO WED. SOME CHC OF SHOWERS
BY LATE THU. 12Z GFS HAS UPPER LVL TROUGH GOING NEGATIVE...
THUS SHOWERS MAY BE SLOW TO MOVE OUT.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE MOVING EAST ACROSS THE STATE WILL KEEP THE REGION
VFR OVERNIGHT AND FRIDAY.
A COLD FRONT WILL MOVE IN FROM THE NORTH EARLY THIS MORNING AND
COULD PRODUCE SOME SHOWERS AND REDUCED CIGS/VSBYS OVER THE NWRN
MOUNTAINS /KBFD/ FRIDAY MORNING...BUT WIDESPREAD REDUCTIONS ARE
NOT EXPECTED AS THE FRONT WILL NOT BE ESPECIALLY STRONG.
LIGHT...GENERALLY SWRLY WINDS THROUGH THE OVERNIGHT PERIOD WILL TURN
NWRLY BEHIND THE FRONT DURING THE DAY ON FRIDAY...WITH GUSTS OF 15
TO 25MPH EXPECTED AT MOST AIRFIELDS.
OUTLOOK...
SAT...NO SIG WX.
SUN...VFR...BUT MVFR POSSIBLE IN SCATTERED SHOWERS.
MON...MAINLY VFR...SOME LOWER CONDITIONS POSSIBLE WITH A COLD
FRONT AND SCATTERED SHOWERS.
TUE...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR
PAZ010>012-017>019-025>028-034>037-041-045-046-049>053-056>059-
063>066.
&&
$$
SYNOPSIS...FITZGERALD/LA CORTE
NEAR TERM...GRUMM/FITZGERALD
SHORT TERM...GRUMM/FITZGERALD
LONG TERM...MARTIN
AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
107 AM EDT FRI OCT 12 2012
.SYNOPSIS...
A COLD FRONT...NEAR THE NORTH SHORE OF LAKE ERIE THIS EVENING...WILL
PUSH THROUGH CENTRAL PENNSYLVANIA FRIDAY MORNING.
A LARGE...COLD AREA OF HIGH PRESSURE WILL BUILD IN FRIDAY NIGHT
FROM THE NORTHERN PLAINS AND BECOME CENTERED OVER THE COMMONWEALTH
AROUND DAYBREAK SATURDAY...BRINGING THE THREAT OF A WIDESPREAD
FROST AND FREEZE TO THE AREA.
THE HIGH WILL MOVE OFF THE MID ATLANTIC COAST BY SUNDAY ALLOWING A
SOUTHWEST FLOW OF MILDER AIR TO RETURN TO THE REGION.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
SATELLITE IMAGERY...IR AND 11-3.9 MICRON SHOW CLOUDS OVER
NORTHWESTERN PA. THE FIRST SURGES INTO WEST CENTRAL AREAS HAVE
DISSIPATED. MOST OF CENTRAL AND SOUTHERN PA ARE SPOT ON CLEAR.
THE CLEAR AREAS WITH DEW POINTS IN THE LOWER 30S HAVE PRODUCED
SOME REMARKABLE TEMPERATURE GRADIENTS. READINGS IN THE UPPER 20S
LOWER 30S. INCREDIBLE RANGE 29 IN PARTS OF CAMBRIA COUNTY AND 31
IN PARTS OF BLAIR COUNTY. MUCH COLDER THAN THE REGIONAL AIRPORTS.
WHERE KJST IS 39 AND KAOO IS 43 AND 44 AT KUNV. SOME PASSING
CLOUDS KEPT SOUTHERN AREAS IN 40S. TEMPERATURES SHOULD BEGIN TO
REBOUND IN EXTREME NORTHWEST WHERE CLOUDS MOVING IN.
THE RURAL NON-AIRPORT OBS REFLECT PATCHY FROST IN RURAL AREAS.
KCLE AND KBUF SHOW VERY LITTLE PRECIPITATION TO OUR WEST. 4KM NAM
AND HRRR ARE NOT VERY AGGRESSIVE WITH RAINFALL EITHER. LOWERED POPS
IN EARLY AM IN NW TO CHANCE.
THE 4KM NAM AT 0000 UTC AND RECENT 0,1,2, 3 UTC RAP DATA IMPLY
SHOWERS IN THE 10-12Z RANGE IN NW PA. BUT THE WEAK SHOWERS SEEM TO
FALL APART AS THEY MOVE INTO THE DRY AIR TO THE SOUTH AND EAST.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM SATURDAY/...
THE COLD FRONT WILL PUSH SOUTH ACROSS THE REGION BTWN 09Z-16Z WITH
THE CHANCE OF SOME LINGERING SHOWERS DURING THE FIRST PART OF THE
MORNING...ESPECIALLY OVER THE NWRN HALF OR SO OF THE STATE.
FRONTAL TIMING IS GOOD WITH THE 13KM RAP.
SHORT RANGE MODELS AGREE IN QUICKLY MOVING THE SFC HIGH AND LOW
PWAT AIR OVERHEAD BY AFTN...WHICH SHOULD BRING CLEARING SKIES.
ENSEMBLE MEAN 850 TEMPS ARE SUPPORTIVE OF HIGH TEMPS FROM JUST THE
M40S OVER THE N MTNS...TO THE U50S ACROSS THE LOWER SUSQ VALLEY. A
FAIRLY TIGHT PRES GRADIENT BEHIND FRONT WILL RESULT IN A BREEZY
DAY. BUFKIT SOUNDINGS SUPPORT FREQUENT GUSTS TO ARND 20KT BY AFTN.
RAP AND MOST GUIDANCE SUGGEST HIGHS RANGE FROM LOWER 40S NW TO
AROUND 60 EXTREME SOUTHEAST.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
NOT MUCH CHANGE FROM RECENT DAYS.
FRIDAY NIGHT LIKELY TO RESULT IN WIDESPREAD FROST...FREEZE
ISSUES...AS A SPRAWLING 1032 MB HIGH PRESSURE BECOMES CENTERED
RIGHT OVER CENTRAL PENN BY 12Z SATURDAY. CLEAR SKIES...LIGHT WINDS...
LOW PW VALUES...AND INVERSION WILL ALLOW TEMPS TO DROP QUICKLY.
EXPANDED THE FREEZE WATCH TO COVER THE LOWER SUSQUEHANNA VLY...
EVEN IF MDT DOES NOT FREEZE...MOST AREAS WILL...AND EVEN THOSE
SPOTS THAT STAY A DEGREE OR TWO ABOVE FREEZING...WILL SEE SOME
FROST.
A MODERATING TREND IS IN STORE FOR SAT...BUT THE REAL MILD TEMPS
WILL ARRIVE SUNDAY INTO MONDAY...AS A STRONG LOW LIFTS NE ACROSS
THE LAKES. TEMPS WILL SPRING BACK INTO THE 60S. 850 MB TEMPS OVER
12 DEGREES C...AND A STRONG SW FLOW...WOULD SUPPORT TEMPS WELL
INTO THE 70S.
SOME SHOWERS ARE POSSIBLE WITH A WARM FRONT SATURDAY NIGHT AND
MORE SHOWERS WITH COLD FRONT LATER SUNDAY INTO MONDAY...HIGHEST
CHC ACROSS THE FAR NORTH. OVERALL...MUCH OF THE TIME WILL BE ON
THE DRY SIDE.
SLIGHTLY COOLER FOR LATER MONDAY INTO WED. SOME CHC OF SHOWERS
BY LATE THU. 12Z GFS HAS UPPER LVL TROUGH GOING NEGATIVE...
THUS SHOWERS MAY BE SLOW TO MOVE OUT.
&&
.AVIATION /05Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE MOVING EAST ACROSS THE STATE WILL KEEP THE REGION
VFR OVERNIGHT AND FRIDAY.
A COLD FRONT WILL MOVE IN FROM THE NORTH LATE TONIGHT AND COULD
PRODUCE SOME SHOWERS AND REDUCED CIGS/VSBYS OVER THE NWRN
MOUNTAINS /KBFD/ FRIDAY MORNING...BUT WIDESPREAD REDUCTIONS ARE
NOT EXPECTED AS THE FRONT WILL NOT BE ESPECIALLY STRONG.
LIGHT...GENERALLY SWRLY WINDS THROUGH THE OVERNIGHT WILL TURN
NWRLY BEHIND THE FRONT DURING THE DAY ON FRIDAY...WITH GUSTS OF
15 TO 25MPH EXPECTED AT MOST AIRFIELDS.
OUTLOOK...
SAT...NO SIG WX.
SUN...VFR...BUT MVFR POSSIBLE IN SCATTERED SHOWERS.
MON...MAINLY VFR...SOME LOWER CONDITIONS POSSIBLE WITH A COLD
FRONT AND SCATTERED SHOWERS.
TUE...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR
PAZ010>012-017>019-025>028-034>037-041-045-046-049>053-056>059-
063>066.
&&
$$
SYNOPSIS...FITZGERALD/LA CORTE
NEAR TERM...GRUMM/FITZGERALD
SHORT TERM...GRUMM/FITZGERALD
LONG TERM...MARTIN
AVIATION...GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
104 AM EDT FRI OCT 12 2012
.SYNOPSIS...
A COLD FRONT...NEAR THE NORTH SHORE OF LAKE ERIE THIS EVENING...WILL
PUSH THROUGH CENTRAL PENNSYLVANIA FRIDAY MORNING.
A LARGE...COLD AREA OF HIGH PRESSURE WILL BUILD IN FRIDAY NIGHT
FROM THE NORTHERN PLAINS AND BECOME CENTERED OVER THE COMMONWEALTH
AROUND DAYBREAK SATURDAY...BRINGING THE THREAT OF A WIDESPREAD
FROST AND FREEZE TO THE AREA.
THE HIGH WILL MOVE OFF THE MID ATLANTIC COAST BY SUNDAY ALLOWING A
SOUTHWEST FLOW OF MILDER AIR TO RETURN TO THE REGION.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
SATELLITE IMAGERY...IR AND 11-3.9 MICRON SHOW CLOUDS OVER
NORTHWESTERN PA. THE FIRST SURGES INTO WEST CENTRAL AREAS HAVE
DISSIPATED. MOST OF CENTRAL AND SOUTHERN PA ARE SPOT ON CLEAR.
THE CLEAR AREAS WITH DEW POINTS IN THE LOWER 30S HAVE PRODUCED
SOME REMARKABLE TEMPERATURE GRADIENTS. READINGS IN THE UPPER 20S
LOWER 30S. INCREDIBLE RANGE 29 KJST AND 32 AT KAOO 44 AT STATE
COLLEGE. SOME PASSING CLOUDS KEPT SOUTHERN AREAS IN 40S.
TEMPERATURES SHOULD BEGIN TO REBOUND IN EXTREME NORTHWEST WHERE
CLOUDS MOVING IN.
KCLE AND KBUF SHOW VERY LITTLE PRECIPITATION TO OUR WEST. 4KM NAM
AND HRRR ARE NOT VERY AGGRESSIVE WITH RAINFALL EITHER. LOWERED POPS
IN EARLY AM IN NW TO CHANCE.
THE 4KM NAM AT 0000 UTC AND RECENT 0,1,2, 3 UTC RAP DATA IMPLY
SHOWERS IN THE 10-12Z RANGE IN NW PA. BUT THE WEAK SHOWERS SEEM TO
FALL APART AS THEY MOVE INTO THE DRY AIR TO THE SOUTH AND EAST.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM SATURDAY/...
THE COLD FRONT WILL PUSH SOUTH ACROSS THE REGION BTWN 09Z-16Z WITH
THE CHANCE OF SOME LINGERING SHOWERS DURING THE FIRST PART OF THE
MORNING...ESPECIALLY OVER THE NWRN HALF OR SO OF THE STATE.
FRONTAL TIMING IS GOOD WITH THE 13KM RAP.
SHORT RANGE MODELS AGREE IN QUICKLY MOVING THE SFC HIGH AND LOW
PWAT AIR OVERHEAD BY AFTN...WHICH SHOULD BRING CLEARING SKIES.
ENSEMBLE MEAN 850 TEMPS ARE SUPPORTIVE OF HIGH TEMPS FROM JUST THE
M40S OVER THE N MTNS...TO THE U50S ACROSS THE LOWER SUSQ VALLEY. A
FAIRLY TIGHT PRES GRADIENT BEHIND FRONT WILL RESULT IN A BREEZY
DAY. BUFKIT SOUNDINGS SUPPORT FREQUENT GUSTS TO ARND 20KT BY AFTN.
RAP AND MOST GUIDANCE SUGGEST HIGHS RANGE FROM LOWER 40S NW TO
AROUND 60 EXTREME SOUTHEAST.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
NOT MUCH CHANGE FROM RECENT DAYS.
FRIDAY NIGHT LIKELY TO RESULT IN WIDESPREAD FROST...FREEZE
ISSUES...AS A SPRAWLING 1032 MB HIGH PRESSURE BECOMES CENTERED
RIGHT OVER CENTRAL PENN BY 12Z SATURDAY. CLEAR SKIES...LIGHT WINDS...
LOW PW VALUES...AND INVERSION WILL ALLOW TEMPS TO DROP QUICKLY.
EXPANDED THE FREEZE WATCH TO COVER THE LOWER SUSQUEHANNA VLY...
EVEN IF MDT DOES NOT FREEZE...MOST AREAS WILL...AND EVEN THOSE
SPOTS THAT STAY A DEGREE OR TWO ABOVE FREEZING...WILL SEE SOME
FROST.
A MODERATING TREND IS IN STORE FOR SAT...BUT THE REAL MILD TEMPS
WILL ARRIVE SUNDAY INTO MONDAY...AS A STRONG LOW LIFTS NE ACROSS
THE LAKES. TEMPS WILL SPRING BACK INTO THE 60S. 850 MB TEMPS OVER
12 DEGREES C...AND A STRONG SW FLOW...WOULD SUPPORT TEMPS WELL
INTO THE 70S.
SOME SHOWERS ARE POSSIBLE WITH A WARM FRONT SATURDAY NIGHT AND
MORE SHOWERS WITH COLD FRONT LATER SUNDAY INTO MONDAY...HIGHEST
CHC ACROSS THE FAR NORTH. OVERALL...MUCH OF THE TIME WILL BE ON
THE DRY SIDE.
SLIGHTLY COOLER FOR LATER MONDAY INTO WED. SOME CHC OF SHOWERS
BY LATE THU. 12Z GFS HAS UPPER LVL TROUGH GOING NEGATIVE...
THUS SHOWERS MAY BE SLOW TO MOVE OUT.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE MOVING EAST ACROSS THE STATE WILL KEEP THE REGION
VFR OVERNIGHT AND FRIDAY.
A COLD FRONT WILL MOVE IN FROM THE NORTH LATE TONIGHT AND COULD
PRODUCE SOME SHOWERS AND REDUCED CIGS/VSBYS OVER THE NWRN
MOUNTAINS /KBFD/ FRIDAY MORNING...BUT WIDESPREAD REDUCTIONS ARE
NOT EXPECTED AS THE FRONT WILL NOT BE ESPECIALLY STRONG.
LIGHT...GENERALLY SWRLY WINDS THROUGH THE OVERNIGHT WILL TURN
NWRLY BEHIND THE FRONT DURING THE DAY ON FRIDAY...WITH GUSTS OF
15 TO 25MPH EXPECTED AT MOST AIRFIELDS.
OUTLOOK...
SAT...NO SIG WX.
SUN...VFR...BUT MVFR POSSIBLE IN SCATTERED SHOWERS.
MON...MAINLY VFR...SOME LOWER CONDITIONS POSSIBLE WITH A COLD
FRONT AND SCATTERED SHOWERS.
TUE...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR
PAZ010>012-017>019-025>028-034>037-041-045-046-049>053-056>059-
063>066.
&&
$$
SYNOPSIS...FITZGERALD/LA CORTE
NEAR TERM...GRUMM/FITZGERALD
SHORT TERM...GRUMM/FITZGERALD
LONG TERM...MARTIN
AVIATION...GARTNER
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
640 AM CDT FRI OCT 12 2012
.DISCUSSION.../ISSUED AT 415 AM CDT/
HIGH PRESSURE WILL SHIFT OFF TO THE EAST DURING THE DAY TODAY
ALLOWING FOR A DECENT SOUTHERLY RETURN FLOW TO DEVELOP. 900 MB WINDS
FORECAST TO INCREASE INTO THE 25 TO 30 KTS RANGE BY THIS AFTERNOON
WEST OF INTERSTATE 29...WITH SLIGHTLY LOWER VALUES TO THE EAST. THIS
SHOULD SUPPORT WIND GUSTS IN THE 25 TO 35 MPH RANGE BY THIS
AFTERNOON...WITH THE HIGHEST GUSTS WEST OF THE JAMES RIVER. MODELS
IN PRETTY GOOD AGREEMENT ON HIGH TEMPERATURES...GENERALLY EXPECTING
MID 50S SOUTHWEST MINNESOTA TO AROUND 60 ALONG THE MISSOURI RIVER.
DESPITE THE COOLER TEMPERATURES...AFTERNOON RELATIVE HUMIDITY VALUES
LIKELY TO BE IN THE 20 TO 25 PERCENT RANGE WITH DEWPOINTS ONLY IN
THE TEENS. THIS WILL CREATE ELEVATED FIRE DANGER ACROSS THE ENTIRE
CWA. ISSUES A RED FLAG WARNING FOR AREAS ALONG AND NORTH OF
INTERSTATE 90...AS THESE ZONES ARE MOST LIKELY TO EXCEED CRITERIA.
OTHER ZONES WILL BE CLOSE...BUT THINK WINDS WILL FALL JUST SHORT
ACROSS NORTHWEST IOWA AND FAR SOUTHEAST SOUTH DAKOTA.
OUR FIRST SIGNIFICANT STORM SYSTEM IN AWHILE WILL APPROACH THE AREA
TONIGHT INTO SATURDAY. FIRST ROUND OF LOW LEVEL THETAE ADVECTION
PUSHES IN PRETTY QUICKLY THIS AFTERNOON...RESULTING IN AN INCREASE
IN LOW LEVEL CLOUDS. LOOKS LIKE SOME INSTABILITY MIGHT EXIST ABOVE
THIS CLOUD DECK...THUS WOULD NOT BE SURPRISED TO SEE SOME ELEVATED
SCATTERED THUNDERSTORMS BY LATE THIS AFTERNOON INTO THIS
EVENING...MAINLY ACROSS NORTHWEST IOWA. MAIN BATCH OF LOW LEVEL
MOISTURE ADVECTION APPROACHES THE CWA AFTER 06Z AS THE LOW LEVEL JET
GETS GOING...AND THINK THE 06Z TO 12Z TIMEFRAME WILL FEATURE THE
MOST WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY. IT NOW APPEARS
LIKE MOST OF THE ACTIVITY WILL BE SOUTHEAST OF A MARSHALL TO TYNDALL
LINE...AS AREAS NORTHWEST OF THIS WILL HAVE TO DEAL WITH A DRIER
PUSH OF AIR FROM THE WEST. ELEVATED CAPE BETWEEN 500 AND 1000 J/KG
EXPECTED TONIGHT IN THE ABOVE MENTIONED AREAS. THUS THINK WE SHOULD
SEE QUITE A BIT OF THUNDER WITH THE SHOWERS...ALTHOUGH SEVERE
WEATHER IS NOT ANTICIPATED...AS STORMS WILL BE BASED ABOVE THE BEST
WIND SHEAR. PWATS STILL EXPECTED TO BE AROUND 3 STANDARD DEVIATIONS
ABOVE NORMAL...SO COULD SEE SOME HEAVY RAIN IN SOME OF THE
CONVECTION TONIGHT...ALTHOUGH ON AVERAGE MOST AREAS WILL PROBABLY
SEE BETWEEN A QUARTER AND A HALF AN INCH.
SATURDAY IS A BIT MORE TRICKY. ELEVATED ACTIVITY SHOULD EXIT
NORTHWEST IOWA DURING THE MORNING...WITH A DRY SLOT WORKING INTO THE
AREA. MAY EVEN SEE A PERIOD OF PARTLY SUNNY SKIES ALLOWING
TEMPERATURES TO REBOUND INTO THE 60S AND 70S...WARMEST IN OUR SOUTH.
TWO SHOTS FOR PRECIPITATION ON SATURDAY...ONE AHEAD OF THE COLD
FRONT ACROSS MAINLY NORTHWEST IOWA...AND THE OTHER ON THE BACKSIDE
OF THE DEEPENING LOW PRESSURE SYSTEM. MODELS IN DISAGREEMENT ON HOW
THEY HANDLE THE UPPER LEVEL LOW. NAM IS FURTHEST SOUTH AND KEEPS ANY
WRAPAROUND RAIN SATURDAY AFTERNOON AND EVENING WELL TO OUR
SOUTH...WHILE THE ECMWF IS FURTHEST NORTH AND STRONGEST WITH THE
WAVE...GIVING UP TO A HALF AN INCH OF RAIN ACROSS NORTHWEST IOWA
SATURDAY EVENING. FAVOR A SOLUTION IN BETWEEN...CLOSER TO THE GFS
AND GEM...WHICH WOULD KEEP MOST OF THE RAIN SOUTH AND EAST OF THE
AREA...ALTHOUGH WILL HAVE TO CONTINUE TO MONITOR TRENDS.
AS FAR AS SEVERE POTENTIAL WITH THE COLD FRONTAL PASSAGE...WILL
DEPEND ON HOW MUCH SUN WE CAN GET AND THUS HOW UNSTABLE WE GET AHEAD
OF THE FRONTAL PASSAGE. WILL NEED TO HEAT ENOUGH TO BREAK THE
INVERSION...WHICH WILL LIKELY ACT AS A CAP AND MAY INHIBIT
CONVECTION AHEAD OF THE FRONT. ONLY THREAT APPEARS TO BE FROM ABOUT
SIOUX CITY TO JACKSON MINNESOTA...WHERE THE GFS IS MOST UNSTABLE
WITH CAPES AROUND 1500 J/KG...WITH THE NAM AND SREF ARE CLOSER TO
500 J/KG. DEEP LAYER SHEAR SHOULD BE PRETTY IMPRESSIVE WITH VALUES
AROUND 40 TO 50 KTS. STRONGEST UPPER LEVEL SUPPORT SHOULD STAY TO
OUR SOUTH WITH THE MAIN UPPER WAVE...HOWEVER WITH THE TROUGH AXIS
PUSHING ACROSS AT THE SAME TIME AS THE FRONT...STILL SHOULD SEE
DECENT LIFT. SO IF STORMS CAN GET GOING ALONG THE FRONT...EVEN THE
MINIMAL CAPE MIGHT EB ENOUGH TO GET SOME OF THE STRONGER WINDS DOWN
TO THE SURFACE.
LOW PRESSURE PUSHES EAST...LEADING TO A DRY SUNDAY. LOOKS
WARM...ALTHOUGH SOME UNCERTAINTY ON HOW QUICKLY LOW LEVEL THERMAL
PROFILES RECOVER BEHIND THE TROUGH...WITH THE NAM SEVERAL DEGREES
WARMER THAN THE ECMWF AND GFS. EITHER WAY SHOULD SEE 60S OR 70S.
WILL STAY BREEZY BEHIND THE SYSTEM...WITH NORTHWESTERLY WINDS
GUSTING AROUND 20 TO 30 MPH. CURRENTLY EXPECTING RH AROUND 30
PERCENT...SO WHILE RED FLAG CONDITIONS PROBABLY WONT BE MET...FIRE
DANGER WILL STILL BE ELEVATED. /CHENARD
NOT MANY CHANGES NEEDED TO THE ON GOING EXTENDED FORECAST NEXT WEEK.
FAIRLY WAVY PATTERN IS EVIDENT WITH AN UPPER FLOW MOVING ON SHORE
ACROSS THE PACIFIC NORTHWEST. THIS WILL PROVIDE A MILD FLOW OF AIR
FOR OUR REGION ON MONDAY AND TUESDAY...WITH ABOVE NORMAL HIGHS IN
THE 70S. ON WEDNESDAY AND THURSDAY...THERE IS QUITE A BIT OF
DISCREPANCY BETWEEN THE VARIOUS DETERMINISTIC MODELS IN HOW THEY
HANDLE THE NEXT WAVE. THE GEM GLOBAL AND GFS ARE GENERALLY IN BETTER
AGREEMENT IN HOW THEY HANDLE THE MID WEEK SHORT WAVE...AS THEY DIG
IT INTO AN UPPER TROUGH AS IT MOVES EASTWARD ACROSS THE PLAINS. THE
ECMWF IS MORE OR LESS IN ITS OWN CAMP. LEFT SOME SMALL POPS IN FOR
TUESDAY NIGHT AND WEDNESDAY TO ACCOUNT FOR THIS PASSAGE...WITH
COOLER TEMPERATURES ON WEDNESDAY AND THURSDAY.
&&
.AVIATION.../FOR THE 12Z TAF ISSUANCE/
VFR CONDITIONS WILL PREVAIL THIS MORNING...THEN CLOUD CONDITIONS
WILL PROBABLY BEGIN TO DETERIORATE A BIT. ALREADY PLENTY OF STRATUS
IN THE MVFR TO LOWER VFR RANGE EXISTS FROM EXTREME SOUTHERN NEBRASKA
TO POINTS SOUTHWARD. ONCE OUR WINDS TURN TO THE SOUTH AND SOUTHEAST
TODAY...THE STRATUS WILL LIKELY BEGIN A RAPID PUSH NORTHWARD INTO
OUR AREA...PUTTING CONDITIONS INTO THE LOWER VFR TO UPPER END MVFR
CATEGORIES FROM SOUTH TO NORTH THIS AFTERNOON. INTERESTINGLY...A
COUPLE OF MODELS SUCH AS THE NAM AND HRRR STRONGLY SUGGEST THAT A
LOWER END VFR DECK WILL SHOOT NORTHWARD UP THE JAMES VALLEY...
AFFECTING THE KHON TAF SITE WITH SOME STRATUS BEFORE IT AFFECTS THE
KFSD TAF SITE. WILL MONITOR THIS. OTHERWISE MID LEVEL INSTABILITY
AND MOISTURE COULD GIVE AN ISOLATED SHOWER OR THUNDERSTORM IN THE
SIOUX CITY AREA LATE THIS AFTERNOON. BUT LATER TONIGHT IS WHEN THE
BETTER RAIN AND THUNDERSTORM CHANCES BEGIN DUE TO STRONG WARM AIR
ADVECTION AHEAD OF LOW PRESSURE. THE KHON TAF SITE MAY GET MISSED.
BUT MUCH BETTER CHANCES FOR THUNDERSTORMS AND MVFR CONDITIONS EXISTS
FOR THE KFSD AND KSUX TAF SITES LATE TONIGHT. FINALLY CONCERNING
WINDS...SOUTHERLY WINDS WITH GUSTS AT OR ABOVE 25 KNOTS WILL DEVELOP
BY MID TO LATE MORNING...WITH THE STRONGEST WINDS AFFECTING THE KHON
AREA DURING THE AFTERNOON.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 7 PM CDT THIS
EVENING FOR MNZ900.
NE...NONE.
SD...RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 7 PM CDT THIS
EVENING FOR SDZ256-257.
&&
$$
AGREEMENT WITH MORNING FORECAST DISCUSSION THAT IT IS CERTAINLY NOT
OUT OF THE QUESTION THAT A SQUALL LINE COULD DEVELOP IN THE FRONTAL
VCNTY...ESPECIALLY DURING THE MORNING HRS ON SUN...WITH DAMAGING
WINDS BEING A CONCERN. MOISTURE RETURN ALSO LOOKS TO BE QUESTIONABLE
WITH THIS SYSTEM TOO...ALTHOUGH BRIEF HEAVY RAINFALL WITH THE
STRONGER SHWRS AND TSTMS THAT DEVELOP IS CERTAINLY ALSO NOT OUT OF
THE QUESTION. ACTUAL TIMING OF ALL THE FEATURES NEEDED FOR A
POTENTIAL SVR WX OUTBREAK TO DEVELOP WILL BE A KEY HERE...BUT AT
THIS TIME THERE CONTINUES TO BE TOO MUCH UNCERTAINTY OVERALL...AND
WILL THUS LEAN TOWARD THE REASONING OF THE LATEST SPC DAY 4-8
CONVECTIVE OUTLOOK...AS THEY CONTINUE TO NOT MENTION THE MID STATE
OR ANY OTHER AREA ACROSS THE ERN U.S. IN ANY REGIONAL WX OUTLOOK FOR
SUN.
OTHERWISE...WILL GO CLOSE TO FORECAST REASONING FROM THIS MORNING ALSO...
AND BELIEVE THAT SOME SHWRS WILL LINGER ACROSS THE PLATEAU REGION THRU
EARLY MON. MODELS COMING MORE INTO LINE WITH THE NEXT SIGNIFICANT COLD
FRONTAL PASSAGE MID TO LATE NEXT WEEK.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1010 PM CDT SAT OCT 13 2012
.DISCUSSION...
THE COLD FRONT WAS CURRENTLY THROUGH THE PANHANDLE AND MOVING
INTO CENTRAL AND NORTHERN TX. ISOLATED THUNDERSTORMS THAT OCCURRED
OVER BURLESON AND BRAZOS COUNTIES EARLIER THIS EVENING HAVE
DIMINISHED. DID HAVE A CONFIRMED REPORT OF A RAIN WRAPPED TORNADO
WITH THE STORM BETWEEN DIME BOX AND CALDWELL...THAT ACTUALLY
STARTED IN LEE COUNTY NEAR LEXINGTON. KUDOS TO WFO EWX FOR THE
ORIGINAL HEADS UP AND THE SPOTTER REPORTS IN LEE COUNTY THAT
HELPED US CONFIRM THE RADAR SIGNATURE AND WARNING DECISIONS FOR
BURLESON COUNTY. ALSO APPRECIATED THE WEATHER SPOTTER IN BURLESON
COUNTY FOR THE TWO REPORTS DURING THE TORNADO WARNING. HELICITY
VALUES ON THE 00Z AREA SOUNDINGS DID INDICATE SOME POTENTIAL...
WITH 0 TO 3 KM VALUES AT 350 AT FWD...133 AT CRP...AND 257 AT
SHV. THE 18Z NAM BUFR MODEL ACTUALLY SHOWED THE BEST POTENTIAL ON
THE CLL FORECAST SOUNDING FOR EARLIER THIS EVENING.
DO EXPECT THE RAIN CHANCES TO INCREASE OVERNIGHT OVER THE
NORTHWESTERN HALF OF THE FORECAST AREA AS THE FRONT APPROACHES
SE TX. THE RAP MESO-SCALE ANALYSIS INDICATES THIS TREND BY SHOWING
PW/S NEARING 1.8 INCHES OVER THE WESTERN COUNTIES.
THE CURRENT RADAR ALSO SHOWS STREAMER SHOWERS DEVELOPING OFF THE
COAST AS THE MOISTURE ADVECTION WAS INCREASING. DECIDED TO UPDATE
THE FORECAST TO INCLUDE ISOLATED SHOWERS IN THE 10 PERCENT POP
AREAS. THESE ARE LOCATED MAINLY TOWARD THE COAST THIS EVENING...
AND ALONG AND OFF THE COAST OVERNIGHT TONIGHT AND SUNDAY MORNING.
40
&&
.PREV DISCUSSION... /ISSUED 911 PM CDT SAT OCT 13 2012/
DISCUSSION...
SEE AVIATION DISCUSSION.
AVIATION...
CLL CURRENTLY HAS A TSRA IN PROGRESS. THAT ACTIVITY SHOULD MOVE TO
THE EAST OF THAT TERMINAL BETWEEN 02 AND 03Z. OTHERWISE MVFR CIGS
EXPECTED AT MOST TERMINALS. COLD FRONT SHOULD PASS THROUGH CLL AND
UTS BETWEEN 15 AND 18Z AND THE HOUSTON METRO AREA BETWEEN 18 AND
22Z. EXPECT SCATTERED SHOWER ACTIVITY AHEAD ON THE FRONT. USED
PROB30 TO ADDRESS THUNDERSTORM ACTIVITY ASSOCIATED WITH THE FRONT.
AT THIS TIME...EXPECT MOST ACTIVITY IN NORTHERN AND WESTERN
PORTIONS OF THE FORECAST AREA WITH DECREASING ACTIVITY AS THE
FRONT APPROACHES THE COAST.
WINDS DURING THE DAY ON SUNDAY SHOULD BE FROM THE SOUTH NEAR 10
KNOTS...BECOMING WESTERLY AND NORTHWESTERLY FOLLOWING FRONTAL
PASSAGE. 44
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 73 86 62 84 59 / 60 50 10 10 0
HOUSTON (IAH) 73 87 64 86 60 / 20 40 30 10 0
GALVESTON (GLS) 76 86 72 83 71 / 10 30 30 10 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION THROUGH SUNDAY MORNING FOR
THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60
NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT
20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...40
AVIATION/MARINE...44
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1147 PM CDT THU OCT 11 2012
.AVIATION...
WINDS HAVE DECREASED TO NEAR 5 KTS LATE THIS EVENING...WITH VFR
CONDITIONS PREVAILING FOR THE NEXT SEVERAL HOURS. TOWARDS THE
MORNING HOURS...LIGHT WINDS WITH DEW POINTS IN THE LOW TO MID 60S
WILL HELP LOWER CIGS TO THE LOW END MVFR CATEGORY UNTIL AROUND
15Z. MAIN HAZARD IN THE TAF PERIOD WILL BE THE POSSIBILITY FOR
STRONG TO SEVERE CONVECTION TOMORROW AFTERNOON...WITH THE PRIMARY
THREAT BEING HAIL...THOUGH SOME THUNDERSTORMS MAY HAVE THE
POTENTIAL TO PRODUCE HIGH WIND GUSTS IN EXCESS OF 40 KTS. GRADIENT
WINDS DURING THE AFTERNOON WILL BE GUSTY...WITH SUSTAINED WINDS
NEAR 14 KTS AND GUSTS UP TO 25 KTS.
&&
.PREV DISCUSSION... /ISSUED 959 PM CDT THU OCT 11 2012/
UPDATE...
9 PM SATELLITE AND RADAR DATA SHOW A BATCH OF SHOWERS AND ISOLD
TSTMS MOVING NEWD FROM EASTERN NM INTO THE WESTERN TX
PANHANDLE...BYPASSING OUR CWA EXCEPT PERHAPS FOR PARMER COUNTY.
SFC OBS SHOW A FRONT JUST MOVING INTO THE NRN TX PANHANDLE. AS THE
FRONT MOVES SOUTH...THE CURRENT ACTIVITY MAY GET A BIT OF A BOOST
FROM LIFT ALONG THE FRONT. MOST OF THIS ACTIVITY SHOULD REMAIN TO
OUR NORTH...BUT COULD SINK SWD INTO OUR NRN ZONES AFTER MIDNIGHT.
THE HRRR HAS BEEN ADVERTISING SCT TSTMS MOVING INTO OUR SW ZONES
AFTER MIDNIGHT FOR SEVERAL RUNS NOW...BUT IT/S DEPICTION OF CURRENT
ACTIVITY IN SE NM AND FAR WEST TEXAS SEEMS OVERDONE...LOWERING
CONFIDENCE IN IT/S FORECAST.
THE 0Z NAM HAS ARRIVED. IT HINTS THAT THERE COULD BE TWO ROUNDS OF
STORMS. THE FIRST ROUND OF STORMS FIRING OFF THE HIER TERRAIN OF
NM BY EARLY AFTERNOON...EVENTUALLY PASSING THROUGH MOST OF THE
CWA FRIDAY EVENING. THEN ANOTHER LINE OF STORMS LATE FRIDAY
NIGHT/SAT MORNING FORCED ALONG A PACIFIC-TYPE FRONT SWEEPING
ACROSS THE FA. FCST SNDGS STILL INDICATE POTENTIAL FOR SEVERE
WEATHER FRIDAY AFTERNOON AND EVENING. THE SOUNDING AT LUBBOCK
SUGGESTS THAT SKIES COULD VERY WELL PARTIALLY CLEAR OUT ALLOWING
SBCAPES TO RISE TO NEAR 2000 J/KG AND TEMPS TO SUFFICIENTLY WARM
FOR SURFACE-BASED CONVECTION. SHEAR APPEARS FAIRLY UNIDRECTIONAL
AT LUBBOCK...BUT WILL LIKELY EXHIBIT MORE TURNING ACROSS THE FAR
SRN TX PANHANDLE.
NO CHANGES IN FCST FOR NOW...WILL WAIT AND SEE WHAT THE 0Z GFS
BRINGS.
PREV DISCUSSION... /ISSUED 633 PM CDT THU OCT 11 2012/
AVIATION...
VFR CONDITIONS WILL PREVAIL AT BOTH TERMINALS DURING THE OVERNIGHT
HOURS. VIS SAT SHOWS A CLUSTER OF CLOUDS BEGINING TO MOVE INTO THE
KCDS AREA...WHICH SHOULD BRING THE CIGS FROM FEW TO BKN
SHORTLY...BUT WILL REMAIN IN THE VFR CATEGORY. ISOLATED TO
SCATTERED CONVECTION WILL MOVE INTO THE AREA LATE THIS EVENING
WHICH COULD IMPACT EITHER TERMINAL. AND STORMS AFFECTING A
TERMINAL COULD BRING CIGS TO MVFR...IFR AT WORST...FOR A SHORT
PERIOD OF TIME. WINDS WILL ALSO BE GUSTY TONIGHT WITH GUSTS TO 25
KTS. CIGS WILL BECOME LOW END MVFR TOWARDS MORNING IN RESPONSE TO
ABUDUNT LOW LEVEL MOISTURE MOVING INTO THE AREA. BIG AREA OF
CONCERN WILL BE TOMORROW AFTERNOON WITH THE POSSIBILITY OF STRONG
TO SEVERE THUNDERSTORMS AFFECTING THE FA. HAIL WILL BE THE PRIMARY
THREAT FOR THUNDERSTORMS...BUT MAY ALSO HAVE SEVERE WIND GUSTS AS
WELL.
PREV DISCUSSION... /ISSUED 350 PM CDT THU OCT 11 2012/
SHORT TERM...
ONGOING CONVECTION ORIGINATING DURING THE LATE AFTERNOON/EARLY
EVENING ACROSS THE EXTREME SOUTHWESTERN TEXAS PANHANDLE WILL PUSH
EAST OVERNIGHT AND LOSE INTENSITY AS IT TRIES TO MOVE INTO THE
SOUTHERN HALF OF THE ROLLING PLAINS. THIS IS DUE TO A MID-LEVEL
SHORTWAVE TROUGH INTERACTING WITH RICH BOUNDARY LAYER MOISTURE AS
EVIDENCED BY DEWPOINTS IN THE LOW 60S. DEEP LAYER INSTABILITY WILL
BE HIGHEST NEAR THE NEW MEXICO STATE LINE AS GREATER MIXING THIS
AFTERNOON SOMEWHAT ALLEVIATES A SHALLOW NEAR-SURFACE COLD POOL WHICH
WILL INHIBIT CONVECTION FARTHER SOUTH AND EAST. A 35 KNOT LOW-LEVEL
JET WILL STRENGTHEN WIND FIELDS AND PROMOTE THE CHANCE FOR CONTINUING
CONVECTION THROUGHOUT THE NIGHT. AREAS ACROSS THE SOUTHEASTERN
ROLLING PLAINS WILL SEE SOME PATCHY FOG FOR A FEW HOURS TOMORROW
MORNING NEAR SUNRISE AS ABUNDANT MOISTURE REMAINS TRAPPED IN A
FAIRLY STABLE NOCTURNAL BOUNDARY LAYER.
A MID-UPPER LEVEL LOW PRESSURE CENTER WILL EJECT NORTHEASTWARD FROM
OFF THE SOUTHERN CALIFORNIA COAST AND MOVE TOWARD THE ROCKY MOUNTAIN
REGION AND CENTRAL GREAT PLAINS. THIS FEATURE WILL BE THE FOCUS FOR
A REGIONAL SEVERE WEATHER OUTBREAK WHICH WILL ENCOMPASS WEST TEXAS.
THE MAIN CONCERN FOR ORGANIZED AND WIDESPREAD SEVERE CONVECTION
FRIDAY AFTERNOON/EVENING WILL BE INSTABILITY DUE TO CLOUD COVER AND
REMNANTS OF MORNING STORMS. DYNAMICS WILL BE FAVORABLE FOR
LARGE-SCALE ASCENT ACROSS THE ENTIRE AREA...WITH THE BEST LIFT
OCCURRING NORTH AND WEST AND DECREASING IN INTENSITY TO THE SOUTH
AND EAST.
AS HEIGHTS FALL AHEAD OF THIS LOW BY MID AFTERNOON...DISCRETE CELLS
WILL HAVE THE INITIAL CHANCE TO COMMENCE. BACKING LOW-LEVEL WINDS
AND INCREASINGLY CLOCKWISE-CURVED HODOGRAPHS WILL SUPPORT THE CHANCE
FOR AN ISOLATED TORNADO. WHILE A FEW SURFACE-BASED STORMS MAY BE
ABLE TO GENERATE TO THE WEST NEAR THE NEW MEXICO STATE LINE...WHERE
BETTER MIXING WILL TAKE PLACE...A RESIDUAL COOLER AND MORE STABLE
BOUNDARY LAYER WILL LIKELY CAUSE STORMS TO BE ELEVATED IN NATURE.
THIS WILL LEAD TO PRIMARILY A HAIL THREAT AS CONVECTIVE WIND GUSTS
MAY STRUGGLE TO REACH THE SURFACE. HEAVY RAIN WILL ALSO BE A
POSSIBILITY WHERE STORMS TRAIN.
LONG TERM...
CONVECTION IS EXPECTED TO CONTINUE THROUGHOUT THE EVENING AND
OVERNIGHT HOURS FRIDAY INTO SATURDAY. THE MOST WIDESPREAD COVERAGE
IS EXPECTED TO BE BETWEEN 00Z AND 06Z. MAXIMUM LIFT FROM THE CLOSED
LOW/TROUGH CONTINUES TO BE PROGGED NORTH OF THE AREA. THE BEST
THERMODYNAMIC PARAMETERS WILL BE CENTERED OVER THE SOUTHWESTERN
TEXAS PANHANDLE AND VERY IMPRESSIVE FOR OCTOBER STANDARDS. AS CLOUDS
CLEAR OUT...CAPES IN EXCESS OF 1000 J/KG WILL BE SEEN NEAR THE
TEXAS...NEW MEXICO STATE LINE. INSTABILITY WILL BE LESS AND CIN WILL
BE HIGHER EAST OF HERE WITH CLOUD COVER PERSISTING FOR A GOOD
PORTION OF THE DAYTIME. THE BEST LOW LEVEL HELICITY AND SHEAR
VECTORS WILL AGAIN BE LOCATED OVER THE SOUTHWESTERN TEXAS PANHANDLE.
MODEL HODOGRAPHS DO SHOW SOME LOW LEVEL TURNING BUT IS STILL RATHER
WEAK. THOUGH IT IS WEAK...IT IS ENOUGH TO NOT BE IGNORED FOR A
TORNADO THREAT. HOWEVER...ABOVE THIS LOW LAYER...STRONG SHEAR WILL
EXIST LENDING TO ORGANIZED SEVERE CONVECTION. LARGE HAIL IS STILL
THE PRIMARY THREAT FROM THIS CONVECTION. WOULD STILL EXPECT MORE
DISCRETE CELLS OVER THE SOUTHWESTERN PANHANDLE AND SOUTH PLAINS AND
MORE LINEAR FEATURES FARTHER NORTH IN THE WESTERN AND CENTRAL
PANHANDLE. STORM CHANCES WILL SHIFT EAST DURING THE EVENING AND
OVERNIGHT WITH THE DEVELOPMENT OF A LOW LEVEL JET. THIS LLJ WILL BE
MAXIMIZED OVER THE ROLLING PLAINS AT IMPRESSIVE SPEEDS NEAR 50KT.
ELEVATED INSTABILITY WILL ALSO CONTINUE THROUGH THE NIGHT WITH THIS
LLJ.
A CLOSED LOW SOLUTION PERSISTING INTO SATURDAY APPEARS MORE
PLAUSIBLE WITH THE LATEST MODEL RUNS. UPPER LEVEL LIFT FROM THIS LOW
WILL BE TRAILING OVER THE ROLLING PLAINS SATURDAY MORNING AND
AFTERNOON. STORM REDEVELOPMENT WILL BE POSSIBLE OVER THIS AREA
DURING THIS TIME PERIOD. A STRONG UPPER LEVEL JET WILL BE MOVING
DIRECTLY OVERHEAD ON SATURDAY. THIS LIFT MAY OBTAIN SOME ASSISTANCE
FROM A PACIFIC FRONT SWEEPING INTO THE ROLLING PLAINS. THIS FRONT IS
EXPECTED TO SIGNIFICANTLY SLOW OR EVEN STALL OUT BY THE AFTERNOON.
SUBSIDENCE AND DRYING OUT WILL OCCUR ON SATURDAY ACROSS THE REST OF
THE AREA AND THEN THROUGH THE ROLLING PLAINS ON SUNDAY. A COLD FRONT
IS STILL EXPECTED BY LATE TUESDAY OR WEDNESDAY. HOWEVER THE GFS IS
NOTABLY STRONGER WITH THIS FRONT THAN THE ECMWF. JDV
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 78 58 75 50 73 / 30 50 70 80 0
TULIA 78 58 76 58 75 / 20 40 50 70 0
PLAINVIEW 79 58 77 58 77 / 20 40 50 70 0
LEVELLAND 80 59 78 57 77 / 20 30 60 60 0
LUBBOCK 79 61 78 62 78 / 20 30 50 60 0
DENVER CITY 80 59 80 58 77 / 20 30 60 50 0
BROWNFIELD 79 59 79 59 78 / 20 30 60 60 0
CHILDRESS 81 64 83 66 82 / 10 30 30 60 20
SPUR 80 65 82 64 80 / 10 30 20 60 20
ASPERMONT 82 66 84 68 82 / 10 10 20 50 30
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
51/33/51
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
648 PM CDT SAT OCT 13 2012
.SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT
305 PM CDT SAT OCT 13 2012
MAIN FORECAST CONCERN IS ON RAIN CHANCES THROUGH SUNDAY.
18Z SURFACE ANALYSIS SHOWS BROAD AREA OF LOW PRESSURE OVER THE
PLAINS...WITH A WARM FRONT DRAPED ACROSS NORTHERN AND EASTERN IOWA.
HIGHER DEW POINT AIR FOUND ALONG AND SOUTH OF THIS BOUNDARY FROM
IOWA SOUTHWARD. AREA RADAR SHOWS HEAVIEST PRECIPITATION OVER EASTERN
WISCONSIN...WITH A DEFORMATION AREA OF LIGHTER RAIN NORTH OF
INTERSTATE 90.
13.12Z MODELS OVERALL OFFER SIMILAR SOLUTIONS...WITH JUST SOME MINOR
DETAIL DIFFERENCES IN CLEARING THE RAIN OUT ON MONDAY.
IN THE NEAR TERM...MAIN WAVE LOOKS TO LIFT EAST-NORTHEAST TONIGHT
INTO ILLINOIS. WITH THE LOW CLOUDS LIMITED INSTABILITY EXPECTED OVER
THE AREA AND THUS SEVERE WEATHER THREAT HAS SHIFTED FURTHER SOUTH
OUT OF THE AREA. LOW LEVEL FRONTOGENESIS STRENGTHENS THIS EVENING
ACROSS NORTHEAST IOWA INTO SOUTHWEST WISCONSIN AND WAVE LIFTS
TOWARDS THE AREA. EXPECT MAIN DEFORMATION OF RAIN TO RE-DEVELOP
ACROSS THE AREA...WITH THE HIGHEST PROBABILITIES AND QPF FROM
NORTHEAST IOWA INTO SOUTHWEST WISCONSIN. 13.15Z HRRR WOULD SUGGEST
NOT A LOT OF RAIN THROUGH 03Z...WITH ONLY SOME LIGHT DRIZZLE OR
LIGHT RAIN. WILL ADD MENTION OF FOG THROUGH THE EARLY EVENING HOURS
BEFORE MORE WIDESPREAD RAIN MOVES IN AFTER 03Z. 13.18Z RAP AND 13.12Z
NAM AND GFS ALL SHOWING JUST 200-300 J/KG OF MOST UNSTABLE CAPES
THIS EVENING AND THUS DID KEEP SCATTERED THUNDER IN THE FORECAST.
WAVE ROTATES THROUGH ILLINOIS EARLY SUNDAY MORNING AND INTO LOWER
MICHIGAN BY AFTERNOON. DEFORMATION PRECIPITATION AREA TO REMAIN OVER
THE FAR SOUTHERN COUNTIES THROUGH THE MORNING HOURS...WITH THE
PRECIPITATION THEN LIFTING TO THE EAST IN THE AFTERNOON. STILL
EXPECTING ANOTHER INCH OR SO OF RAINFALL FOR PORTIONS OF SOUTHWEST
WISCONSIN AND NORTHEAST IOWA THROUGH SUNDAY.
UPPER LEVEL RIDGING THEN BUILDS INTO THE REGION FOR SUNDAY NIGHT
INTO MONDAY. EXPECT THE CLOUDS TO BEGIN CLEARING OUT FROM WEST TO
EAST SUNDAY AFTERNOON...WITH CLEAR SKIES EXPECTED SUNDAY NIGHT. WITH
THE SURFACE HIGH DROPPING SOUTH THROUGH THE CENTRAL
PLAINS...SOUTHERLY WINDS ON MONDAY WILL PULL SOME WARMER AIR
NORTHWARD...WITH TEMPERATURES EXPECTED TO BE ABOVE NORMAL...PERHAPS
HITTING 70 DEGREES OVER SOUTHEAST MINNESOTA AND NORTHEAST IOWA.
THE NEXT WAVE THEN BEGINS TO DROP THROUGH THE NORTHERN PLAINS
MONDAY NIGHT INTO TUESDAY. SOUTHERLY WINDS WILL KEEP THE
TEMPERATURES UP MONDAY NIGHT WITH THE FRONT THEN APPROACHING THE
AREA TUESDAY. UPPER WAVE LOOKS TO TRACK ACROSS NORTHERN WISCONSIN
TUESDAY AND ALTHOUGH NOT A LOT OF MOISTURE TO WORK WITH...COULD SEE
A FEW SHOWERS AND THUS LOWER END PROBABILITIES LOOK REASONABLE.
.LONG TERM...WEDNESDAY THROUGH SATURDAY
305 PM CDT SAT OCT 13 2012
THIS PERIOD LOOKS TO BE DOMINATED BY A DIGGING TROUGH ACROSS THE
NORTHERN PLAINS INTO THE GREAT LAKES REGION. BOTH THE 13.12Z ECMWF
AND GFS BOTH CARVE THIS UPPER LOW OUT IN THE WEDNESDAY/THURSDAY TIME
FRAME...BUT THEN DIVERGE IN THEIR SOLUTIONS BEYOND THURSDAY. GFS
MORE PROGRESSIVE IN OPENING THE WAVE UP AND PUSHING IT EASTWARD
FRIDAY/SATURDAY...WHILE THE ECMWF SPINS THE UPPER LOW OVER THE UPPER
MIDWEST/GREAT LAKES REGION INTO SATURDAY. GIVEN THESE UNCERTAINTIES
FEEL THAT PROBABILITIES ARE WARRANTED THROUGH THE ENTIRE PERIOD.
TEMPERATURES LOOK TO BE AT OR BELOW NORMAL FOR MUCH OF THE TIME
PERIOD.
&&
.AVIATION...TONIGHT AND SUNDAY
648 PM CDT SAT OCT 13 2012
TRICKY AVIATION FORECAST ON TAP TONIGHT...WITH FOCUS ON CEILINGS
TONIGHT AND THEN PRECIPITATION CHANCES THROUGH SUNDAY.
LATEST SURFACE ANALYSIS HAS WARM FRONT DRAPED FROM SOUTHWEST
MINNESOTA TO NEAR KGRB...SLOWLY LIFTING NORTH WITH WIDESPREAD
IFR/LIFR CONDITIONS NORTH AND MVFR/VFR CONDITIONS SOUTH IN THE WARM
SECTOR. CURRENTLY KRST/KLSE ARE ON THE EDGE...BUT THE TREND IN THE
NEAR TERM IS FOR BOTH SITES TO REMAIN AT MVFR. THEN AS THE
SURFACE LOW CURRENTLY ACROSS KANSAS LIFTS NORTHEAST AND
DEEPENS...LOWER CEILINGS AND MAYBE RAIN SHOWERS WILL SPREAD NORTH
OVER THE REGION. AT THIS POINT...THIS LOOKS TO BE AFTER 06Z. THERE
IS A POSSIBILITY THE BULK OF THE ACTIVITY COULD STAY SOUTH/EAST OF
THE TAF SITES...AND IF THIS OCCURS THEN THE FORECAST LIFR
CONDITIONS MAY NOT BE SEEN AND WOULD END UP AS LOW-END MVFR. THE
LATEST MESO-MODELS AND 13.18Z NAM SUGGEST KRST/KLSE WOULD MAINLY
BE DRY...WITH SOME OF THE OTHER MESO-MODELS PUTTING THE
DEFORMATION RAIN BAND OVER TAF SITES. IN SHORT...VERY CLOSE CALL
BUT FOR NOW FEEL COMFORTABLE IN DELAYING ONSET A FEW HOURS...AND
MONITORING TRENDS THROUGH THE EVENING.
AS THE SURFACE LOW DEPARTS THE REGION SUNDAY AFTERNOON...A GRADUAL
RISE IN CEILINGS IS EXPECTED AS THE BOUNDARY LAYER MIXES OUT.
WINDS WILL TURN TO THE NORTHWEST...BECOMING GUSTY AT KRST AS DRIER
AIR WORKS IN.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
305 PM CDT SAT OCT 13 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RABERDING
LONG TERM...RABERDING
AVIATION...ZT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1230 PM CDT FRI OCT 12 2012
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
258 AM CDT FRI OCT 12 2012
MAIN FORECAST CONCERN IS ON SEVERE WEATHER POTENTIAL SATURDAY INTO
SATURDAY NIGHT.
CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A SPLIT FLOW PATTERN ACROSS NORTH AMERICA. IN THE NORTHERN
STREAM...WEAK RIDGING WAS NOTED OVER THE NORTHERN U.S. ROCKIES AND
THEN DOWNSTREAM TROUGHING OVER THE GREAT LAKES. IN THE SOUTHERN
STREAM...AN UPPER LOW WAS OVER SOUTHERN CALIFORNIA WITH RIDGING
BUILDING UP AHEAD OF IT ACROSS THE CENTRAL AND SOUTHERN PLAINS. OVER
THE FORECAST AREA...SATELLITE IMAGERY SHOWED SKIES HAVE CLEARED OUT
THANKS TO SUBSIDENCE AND DRYING IN THE WAKE OF THE GREAT LAKES
TROUGHING. ALSO REFLECTED OF THE SUBSIDENCE IS A 1030MB SURFACE HIGH
CENTERED NEAR MINNEAPOLIS. PRECIPITABLE WATER VALUES WERE QUITE DRY
ON THE 00Z MPX SOUNDING...0.17 INCHES OR 30 PERCENT NORMAL. SURFACE
DEWPOINTS ALSO REFLECTIVE OF THE DRYING...DOWN IN THE TEENS TO LOWER
20S. DECENT AMOUNT OF COLD AIR ACCOMPANYING THE SURFACE HIGH WITH
850MB TEMPS THAT DROPPED TO -4C AT MPX AT 00Z COMPARED TO +3C 12
HOURS EARLIER. TO THE SOUTH...A STATIONARY FRONTAL BOUNDARY WAS
POSITIONED FROM OKLAHOMA INTO THE OHIO RIVER VALLEY. SOUTH OF THIS
FRONT...PLENTIFUL MOISTURE WAS NOTED WITH SURFACE DEWPOINTS IN THE
MID 60S TO LOWER 70S ACROSS OKLAHOMA AND MUCH OF TEXAS. 00Z FORT
WORTH SOUNDING HAD A PRECIPITABLE WATER VALUE OF 1.6 INCHES OR 176
PERCENT OF NORMAL. 850MB PROFILER AND VWP DATA CURRENTLY SHOWS MUCH
OF THIS MOISTURE BEING ADVECTED INTO AND ALONG THE STATIONARY
FRONTAL BOUNDARY.
TODAY AND TONIGHT...MAJOR CHANGES LOOK TO OCCUR IN THE WEATHER
PATTERN ACROSS THE FORECAST AREA DURING THIS TIME. THE UPPER LOW IN
CALIFORNIA MODELS ARE ALL IN GOOD AGREEMENT LIFTING IT OUT INTO
NORTHEAST COLORADO BY 12Z SATURDAY. IN RESPONSE TO THIS EJECTION THE
SUBTROPICAL RIDGING BUILDING OVER THE CENTRAL AND SOUTHERN PLAINS
GETS PULLED NORTHWARD INTO THE FORECAST AREA. AS A RESULT...THIS
HIGH PRESSURE BUILDING INTO THE FORECAST AREA RIGHT NOW AT THE
SURFACE WILL NOT HANG AROUND LONG. IN FACT...BY 00Z...15-20
SOUTHERLY 925MB WINDS ARE PROGGED AS THE HIGH SHIFTS OVER LAKE ERIE.
WE SHOULD SEE PLENTY OF SUN TODAY BEING UNDER THE INFLUENCE OF DRY
AIR NOTED ON THE 00Z MPX SOUNDING. 850MB TEMPS AT 18Z AROUND 1C IN
NORTHEAST IOWA TO -4C IN TAYLOR COUNTY SUGGESTS HIGHS FROM THE UPPER
40S TO MID 50S...COOLEST AS EXPECTED IN TAYLOR COUNTY. THINGS GET A
LITTLE MORE INTERESTING TONIGHT AS 850MB MOISTURE TRANSPORT KICKS
INTO HIGH GEAR AHEAD OF THE EJECTING UPPER LOW. 850MB WINDS
THEMSELVES ARE PROGGED TO INCREASE TO 35 TO 50 KT FROM THE SOUTHERN
PLAINS INTO THE FORECAST AREA BY 06Z...HELPING TO BRING UP THE
MOISTURE CURRENTLY SEEN ACROSS OKLAHOMA AND TEXAS. THIS RAPID
INCREASE IN MOISTURE WILL LEAD TO PRECIPITATION DEVELOPMENT...
PERHAPS AS EARLY AS 03Z AS SUGGESTED BY THE 12.00Z NAM. MORE LIKELY
IS TO HAVE WIDESPREAD SHOWERS ACROSS THE FORECAST AREA AFTER 06Z.
THUNDERSTORMS ARE ALSO EXPECTED WITH THIS ACTIVITY WITH MODELS
SHOWING UPWARDS OF 600 J/KG OF MUCAPE...MOSTLY ROOTED AT OR ABOVE
850MB PER CROSS-SECTIONS...ACCOMPANYING THE MOISTURE TRANSPORT. IN
ADDITION TO THE MOISTURE ADVECTION...850MB TEMPS ARE GOING TO SHOOT
UP...REACHING AROUND 12C BY 12Z. AS SUCH...ANTICIPATING LOWS IN THE
EVENING WITH TEMPERATURES RISING THEREAFTER.
SATURDAY AND SATURDAY NIGHT...THIS PERIOD HAS BEEN INTERESTING TO
WATCH OVER THE PAST SEVERAL DAYS WITH RESPECT TO WHAT HAPPENS WITH
THE UPPER LOW. ALL MODELS EXCLUDING THE NAM HAVE HAD ISSUES WITH THE
TRACK AND SPEED. HOWEVER...THERE IS A STRONG CONSENSUS NOW THAT THIS
UPPER LOW IS GOING TO TRACK EAST INTO SOUTHERN IOWA BY 12Z SUNDAY
AND TAKE ON A NEGATIVE TILT. MUCH OF THIS IS CAUSED BY A POTENT
SHORTWAVE HANGING BACK FROM THE UPPER LOW CROSSING THE SOUTHERN
PLAINS. THIS HAS BIG IMPLICATIONS FOR THE FORECAST AREA AS IT
DICTATES THE TRACK OF THE BEST PV ADVECTION...WHICH NOW STAYS MOSTLY
SOUTH OF THE AREA UNTIL MAYBE 12Z SUNDAY SOUTH OF I-90. STILL...
THERE IS PLENTY OF FORCING FOR PRECIPITATION. ON SATURDAY...THE
FORCING REMAINS THAT PERSISTENT STRONG 850MB MOISTURE TRANSPORT ZONE
WITH THE NOSE INTO THE FORECAST AREA. NOTE THAT THE ZONE DOES SLOWLY
SHIFT EAST IN RESPONSE TO THE APPROACHING UPPER LOW. AS SUCH...
PRECIPITATION MAY DIMINISH IN THE AFTERNOON ACROSS MINNESOTA.
PERSISTENT ADVECTION OF INSTABILITY WITHIN THE MOISTURE TRANSPORT...
WHICH SHOULD INCREASE THROUGH THE DAY AS THE AIRMASS SOUTH OF THE
AREA HEATS UP...SUGGESTS QUITE A BIT OF THUNDERSTORM ACTIVITY. BY
21Z AND CONTINUING THROUGH THE EVENING...500-1000 J/KG OF MUCAPE IS
PROGGED OVER THE FORECAST AREA...HIGHEST SOUTH OF I-90.
PRECIPITATION OVERALL LOOKS PRETTY GOOD FOR MOST OF THE AREA
SATURDAY NIGHT TOO...DUE TO A COMBINATION OF INCREASING LOW TO MID
LEVEL FRONTOGENESIS AND RIGHT ENTRANCE REGION SUPPORT FROM AN UPPER
JET DEVELOPING OVER UPPER MICHIGAN. NORTHWEST SECTIONS OF THE AREA
COULD BE ON THE EDGE OF THE PRECIPITATION... THOUGH...AS INDICATED
BY THE 12.00Z NAM AND AS SUCH SLIGHT LOWER CHANCES ARE PRESENT
THERE. GENERALLY FOLLOWED A BLEND OF GUIDANCE FOR HIGHS AND LOWS.
ONE SIDE NOTE WHICH REFLECTS THE CHANGE IN AIRMASSES...MOST
LOCATIONS WILL SEE A DEWPOINT JUMP OF 30 TO 40 DEGREES IN 24 HOURS
BETWEEN 21Z TODAY AND 21Z SATURDAY.
SEVERE WEATHER POTENTIAL FOR SATURDAY INTO SATURDAY NIGHT...ALTHOUGH
THE 500-1000 J/KG OF CAPE IN THE AFTERNOON AND EVENING IS THIN...
EXTENDING UP TO AN EQUILIBRIUM LEVEL AROUND 250MB...THE
ENVIRONMENT FOR THE MOST PART IS UNCAPPED IN THE WARM SECTOR AHEAD
OF A SURFACE LOW COMING ACROSS NORTHERN IOWA. WARM SECTOR LOOKS TO
BE SITUATED MOSTLY SOUTH OF I-90. COMBINE THIS CAPE WITH A HIGHLY
SHEARED ENVIRONMENT NOTED BY 0-6KM SHEAR OF 40-50KT AND 0-1KM
SHEAR AROUND 25 KT YIELDS CONCERN OF DISCRETE TORNADIC SUPERCELLS
IN THE WARM SECTOR. HODOGRAPHS SUGGEST STRONGLY DOMINANT RIGHT
MOVING SUPERCELLS. DAMAGING WINDS WOULD BE A CONCERN TOO GIVEN THE
SHEAR. THIN CAPE PLUS RELATIVELY HIGH FREEZING LEVELS FOR THIS
TIME OF YEAR (AROUND 11000 FT) SHOULD PRECLUDE MUCH OF A LARGE
HAIL HAZARD. OVERALL...HIGHER SEVERE THREAT SHOULD EXIST SOUTH OF
THE FORECAST AREA WHERE CAPE AND DYNAMIC FORCING IS GREATER.
SWODY2 SEVERE WEATHER PROBABILITIES DEPICT THIS WELL. IT SHOULD BE
STRESSED THAT ANY UNEXPECTED SUNSHINE ON SATURDAY COULD
DRAMATICALLY INCREASE THE SEVERE WEATHER POTENTIAL. PRESENT
FORECASTS PORTRAY A MORE LIKELY CLOUDY SCENARIO.
SUNDAY AND SUNDAY NIGHT...MODELS ARE PRETTY QUICK IN EJECTING THE
NEGATIVE TILT SHORTWAVE AND THE ASSOCIATED SURFACE SYSTEM AWAY FROM
THE AREA. BY 00Z MONDAY...BOTH FEATURES SHOULD BE NEAR LAKE HURON.
THEREFORE...AFTER SOME DEFORMATION PRECIPITATION ON THE BACK SIDE OF
THE SYSTEM AFFECTS THE AREA IN THE MORNING...ESPECIALLY ACROSS
WISCONSIN...ANTICIPATING CONDITIONS TO DRY OUT FOR THE AFTERNOON.
UPPER TROUGHING DOES LINGER OVER THE AREA THROUGH SUNDAY NIGHT...
AIDED BY A FEW PACIFIC SHORTWAVES DROPPING IN BEHIND THE NEGATIVELY
TILTED SHORTWAVE. HOWEVER...AT MOST IT LOOKS LIKE THESE WOULD BRING
CLOUDS. DESPITE BEING IN COLD ADVECTION IN THE WAKE OF SUNDAYS
SYSTEM...850MB TEMPS ONLY FALL TO 2-4C. COMBINE THIS WITH SOME
AFTERNOON SUN SHOULD BOOST HIGHS INTO THE MID 50S TO LOW
60S...WARMEST WEST OF THE MISSISSIPPI RIVER WHERE THE MOST SUN IS
EXPECTED. COULD BE A COOL NIGHT SUNDAY NIGHT WITH A SURFACE RIDGE
BUILDING IN...BUT IT WILL ALL DEPEND ON THE CLOUDS. HAVE LEANED
TOWARDS A BLEND OF GUIDANCE WITH A KNOCK DOWN IN TEMPS FOR THE
TYPICAL COOLER SPOTS. MAY HAVE TO KEEP AN EYE ON VALLEY FOG
POTENTIAL IF THE SURFACE RIDGE BUILDS IN A LITTLE FASTER AND SKIES
STAY MOSTLY CLEAR.
.LONG TERM...MONDAY THROUGH THURSDAY NIGHT
258 AM CDT FRI OCT 12 2012
12.00Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES PORTRAY YET ANOTHER
PATTERN CHANGE DURING THE LONG TERM PERIOD...FORECASTING TROUGHING
ACROSS THE NORTHERN PLAINS INTO THE WESTERN GREAT LAKES BY THURSDAY.
THIS IS SIMILAR TO WHAT WE HAVE JUST EXPERIENCED FOR THE PAST
WEEK...THOUGH THE AIR IN THE TROUGH IS NOT NEARLY AS COOL.
THE PERIOD BEGINS WITH A FAST WEST-NORTHWEST FLOW FROM THE PACIFIC
NORTHWEST INTO THE NORTHERN PLAINS. THERE ARE INDICATIONS OF A
SHORTWAVE RIDING THROUGH THIS FLOW AND AMPLIFYING A TROUGH OVER THE
NORTHERN PLAINS ON TUESDAY...CAUSING RIDGING TO DEVELOP OVER THE
FORECAST AREA. THUS...IT WOULD APPEAR MONDAY AND IN PARTICULAR
TUESDAY SHOULD BE THE WARM DAYS OF THE WEEK. 850MB TEMPS CLIMB TO
6-9C BY 00Z TUESDAY AND 8-11C BY 00Z WEDNESDAY. MAY NOT BE ABLE TO
REALIZE THE FULL WARMTH ON TUESDAY...THOUGH...AS WARM ADVECTION AND
DPVA FORCED CLOUDS AND PRECIPITATION SPREAD INTO THE AREA AHEAD OF
THE NORTHERN PLAINS TROUGH. THE NORTHERN PLAINS TROUGH IS THEN
SUGGESTED TO SHIFT EAST OVER THE AREA FOR WEDNESDAY INTO THURSDAY.
KEPT PRECIPITATION CHANCES GOING FOR WEDNESDAY INTO WEDNESDAY NIGHT
PER CONSENSUS...DUE TO A DECENT STRENGTH SHORTWAVE SUGGESTED TO DROP
INTO THE TROUGH. AS THE SHORTWAVE PUSHES OFF TO THE EAST FOR
THURSDAY...FOLLOWED A DRY FORECAST. AGAIN...TEMPERATURES WILL COOL
DOWN WEDNESDAY INTO THURSDAY AS 850MB TEMPS DROP TO 4-6C AND 2-4C
RESPECTIVELY. AFTER MONDAY THROUGH WEDNESDAY PROGGED TO MAINLY BE IN
THE 60S...THURSDAY LOOKS TO END UP THE 50S.
&&
.AVIATION...THROUGH 18Z SATURDAY
1230 PM CDT FRI OCT 12 2012
BIGGEST FORECAST CONCERN IS ON CONVECTION LATE TONIGHT INTO
SATURDAY AND CEILINGS HEIGHTS. HIGH PRESSURE DRIFTS EAST OF THE
AREA THIS AFTERNOON...WITH RATHER IMPRESSIVE MOISTURE RETURN THIS
EVENING. LOW LEVEL JET STRENGTHENS WITH MOISTURE TRANSPORT NOSING
INTO THE REGION AFTER 03Z THIS EVENING. EXPECT SHOWERS TO DEVELOP
OVER THE AREA BETWEEN 03Z-06Z AND THEN CONTINUE TO ERUPT THROUGH
THE OVERNIGHT HOURS. INSTABILITY DOES INCREASE THROUGH THE NIGHT
AND DID INCLUDE VCTS AT BOTH SITES. EXPECT CEILINGS TO DECREASE
AFTER 06Z INTO THE MVFR CATEGORY AND CANNOT RULE OUT SOME IFR
CEILINGS AFTER 10Z AND THEN CONTINUING THROUGH 18Z. WITH THE
INCREASING LOW LEVEL JET TONIGHT DID ADD MENTION OF LLWS AT KLSE
AS 2000 FOOT WINDS INCREASE TO 48 TO 50 KNOTS WHILE SURFACE WINDS
EXPECTED AROUND 10 TO 12 KNOTS.
&&
.HYDROLOGY...TONIGHT THROUGH SUNDAY
258 AM CDT FRI OCT 12 2012
QPF WISE FOR THE TONIGHT THROUGH SUNDAY MORNING SYSTEM...REALLY HARD
TO SAY. THE MAXIMUM AREA SHOULD BE OVER THE SOUTHEASTERN 1/3 OF THE
FORECAST AREA...WHERE THE LONGEST PERIOD OF 850MB MOISTURE TRANSPORT
NOSES IN AND THEN GETS HIT BY THE DEFORMATION ON THE BACK SIDE OF
THE SYSTEM. PRECIPITABLE WATER VALUES CLIMB TO AROUND 1.5 INCHES OR
200-250 PERCENT OF NORMAL TONIGHT AND HOVER AROUND THERE INTO SUNDAY
MORNING. POTENTIAL IS DEFINITELY THERE TO GET 1 TO 2 INCHES FOR THE
ENTIRE TIME PERIOD...AS SUGGESTED BY HPC FORECASTS AND SREF
PROBABILITIES...WITH LOCALLY HIGHER AMOUNTS DUE TO THE CONVECTIVE
NATURE. IN FACT...THE LATEST 12.00Z ECMWF HAS UPWARDS OF 3-3.5
INCHES. THE LANDSCAPE AND RIVERS REALLY COULD USE THIS RAIN GIVEN
THE SEVERE TO EXTREME DROUGHT CONDITIONS IN PLACE. THEREFORE...NO
FLOODING IS ANTICIPATED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
258 AM CDT FRI OCT 12 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...JLR
HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
603 AM CDT FRI OCT 12 2012
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
258 AM CDT FRI OCT 12 2012
MAIN FORECAST CONCERN IS ON SEVERE WEATHER POTENTIAL SATURDAY INTO
SATURDAY NIGHT.
CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A SPLIT FLOW PATTERN ACROSS NORTH AMERICA. IN THE NORTHERN
STREAM...WEAK RIDGING WAS NOTED OVER THE NORTHERN U.S. ROCKIES AND
THEN DOWNSTREAM TROUGHING OVER THE GREAT LAKES. IN THE SOUTHERN
STREAM...AN UPPER LOW WAS OVER SOUTHERN CALIFORNIA WITH RIDGING
BUILDING UP AHEAD OF IT ACROSS THE CENTRAL AND SOUTHERN PLAINS. OVER
THE FORECAST AREA...SATELLITE IMAGERY SHOWED SKIES HAVE CLEARED OUT
THANKS TO SUBSIDENCE AND DRYING IN THE WAKE OF THE GREAT LAKES
TROUGHING. ALSO REFLECTED OF THE SUBSIDENCE IS A 1030MB SURFACE HIGH
CENTERED NEAR MINNEAPOLIS. PRECIPITABLE WATER VALUES WERE QUITE DRY
ON THE 00Z MPX SOUNDING...0.17 INCHES OR 30 PERCENT NORMAL. SURFACE
DEWPOINTS ALSO REFLECTIVE OF THE DRYING...DOWN IN THE TEENS TO LOWER
20S. DECENT AMOUNT OF COLD AIR ACCOMPANYING THE SURFACE HIGH WITH
850MB TEMPS THAT DROPPED TO -4C AT MPX AT 00Z COMPARED TO +3C 12
HOURS EARLIER. TO THE SOUTH...A STATIONARY FRONTAL BOUNDARY WAS
POSITIONED FROM OKLAHOMA INTO THE OHIO RIVER VALLEY. SOUTH OF THIS
FRONT...PLENTIFUL MOISTURE WAS NOTED WITH SURFACE DEWPOINTS IN THE
MID 60S TO LOWER 70S ACROSS OKLAHOMA AND MUCH OF TEXAS. 00Z FORT
WORTH SOUNDING HAD A PRECIPITABLE WATER VALUE OF 1.6 INCHES OR 176
PERCENT OF NORMAL. 850MB PROFILER AND VWP DATA CURRENTLY SHOWS MUCH
OF THIS MOISTURE BEING ADVECTED INTO AND ALONG THE STATIONARY
FRONTAL BOUNDARY.
TODAY AND TONIGHT...MAJOR CHANGES LOOK TO OCCUR IN THE WEATHER
PATTERN ACROSS THE FORECAST AREA DURING THIS TIME. THE UPPER LOW IN
CALIFORNIA MODELS ARE ALL IN GOOD AGREEMENT LIFTING IT OUT INTO
NORTHEAST COLORADO BY 12Z SATURDAY. IN RESPONSE TO THIS EJECTION THE
SUBTROPICAL RIDGING BUILDING OVER THE CENTRAL AND SOUTHERN PLAINS
GETS PULLED NORTHWARD INTO THE FORECAST AREA. AS A RESULT...THIS
HIGH PRESSURE BUILDING INTO THE FORECAST AREA RIGHT NOW AT THE
SURFACE WILL NOT HANG AROUND LONG. IN FACT...BY 00Z...15-20
SOUTHERLY 925MB WINDS ARE PROGGED AS THE HIGH SHIFTS OVER LAKE ERIE.
WE SHOULD SEE PLENTY OF SUN TODAY BEING UNDER THE INFLUENCE OF DRY
AIR NOTED ON THE 00Z MPX SOUNDING. 850MB TEMPS AT 18Z AROUND 1C IN
NORTHEAST IOWA TO -4C IN TAYLOR COUNTY SUGGESTS HIGHS FROM THE UPPER
40S TO MID 50S...COOLEST AS EXPECTED IN TAYLOR COUNTY. THINGS GET A
LITTLE MORE INTERESTING TONIGHT AS 850MB MOISTURE TRANSPORT KICKS
INTO HIGH GEAR AHEAD OF THE EJECTING UPPER LOW. 850MB WINDS
THEMSELVES ARE PROGGED TO INCREASE TO 35 TO 50 KT FROM THE SOUTHERN
PLAINS INTO THE FORECAST AREA BY 06Z...HELPING TO BRING UP THE
MOISTURE CURRENTLY SEEN ACROSS OKLAHOMA AND TEXAS. THIS RAPID
INCREASE IN MOISTURE WILL LEAD TO PRECIPITATION DEVELOPMENT...
PERHAPS AS EARLY AS 03Z AS SUGGESTED BY THE 12.00Z NAM. MORE LIKELY
IS TO HAVE WIDESPREAD SHOWERS ACROSS THE FORECAST AREA AFTER 06Z.
THUNDERSTORMS ARE ALSO EXPECTED WITH THIS ACTIVITY WITH MODELS
SHOWING UPWARDS OF 600 J/KG OF MUCAPE...MOSTLY ROOTED AT OR ABOVE
850MB PER CROSS-SECTIONS...ACCOMPANYING THE MOISTURE TRANSPORT. IN
ADDITION TO THE MOISTURE ADVECTION...850MB TEMPS ARE GOING TO SHOOT
UP...REACHING AROUND 12C BY 12Z. AS SUCH...ANTICIPATING LOWS IN THE
EVENING WITH TEMPERATURES RISING THEREAFTER.
SATURDAY AND SATURDAY NIGHT...THIS PERIOD HAS BEEN INTERESTING TO
WATCH OVER THE PAST SEVERAL DAYS WITH RESPECT TO WHAT HAPPENS WITH
THE UPPER LOW. ALL MODELS EXCLUDING THE NAM HAVE HAD ISSUES WITH THE
TRACK AND SPEED. HOWEVER...THERE IS A STRONG CONSENSUS NOW THAT THIS
UPPER LOW IS GOING TO TRACK EAST INTO SOUTHERN IOWA BY 12Z SUNDAY
AND TAKE ON A NEGATIVE TILT. MUCH OF THIS IS CAUSED BY A POTENT
SHORTWAVE HANGING BACK FROM THE UPPER LOW CROSSING THE SOUTHERN
PLAINS. THIS HAS BIG IMPLICATIONS FOR THE FORECAST AREA AS IT
DICTATES THE TRACK OF THE BEST PV ADVECTION...WHICH NOW STAYS MOSTLY
SOUTH OF THE AREA UNTIL MAYBE 12Z SUNDAY SOUTH OF I-90. STILL...
THERE IS PLENTY OF FORCING FOR PRECIPITATION. ON SATURDAY...THE
FORCING REMAINS THAT PERSISTENT STRONG 850MB MOISTURE TRANSPORT ZONE
WITH THE NOSE INTO THE FORECAST AREA. NOTE THAT THE ZONE DOES SLOWLY
SHIFT EAST IN RESPONSE TO THE APPROACHING UPPER LOW. AS SUCH...
PRECIPITATION MAY DIMINISH IN THE AFTERNOON ACROSS MINNESOTA.
PERSISTENT ADVECTION OF INSTABILITY WITHIN THE MOISTURE TRANSPORT...
WHICH SHOULD INCREASE THROUGH THE DAY AS THE AIRMASS SOUTH OF THE
AREA HEATS UP...SUGGESTS QUITE A BIT OF THUNDERSTORM ACTIVITY. BY
21Z AND CONTINUING THROUGH THE EVENING...500-1000 J/KG OF MUCAPE IS
PROGGED OVER THE FORECAST AREA...HIGHEST SOUTH OF I-90.
PRECIPITATION OVERALL LOOKS PRETTY GOOD FOR MOST OF THE AREA
SATURDAY NIGHT TOO...DUE TO A COMBINATION OF INCREASING LOW TO MID
LEVEL FRONTOGENESIS AND RIGHT ENTRANCE REGION SUPPORT FROM AN UPPER
JET DEVELOPING OVER UPPER MICHIGAN. NORTHWEST SECTIONS OF THE AREA
COULD BE ON THE EDGE OF THE PRECIPITATION... THOUGH...AS INDICATED
BY THE 12.00Z NAM AND AS SUCH SLIGHT LOWER CHANCES ARE PRESENT
THERE. GENERALLY FOLLOWED A BLEND OF GUIDANCE FOR HIGHS AND LOWS.
ONE SIDE NOTE WHICH REFLECTS THE CHANGE IN AIRMASSES...MOST
LOCATIONS WILL SEE A DEWPOINT JUMP OF 30 TO 40 DEGREES IN 24 HOURS
BETWEEN 21Z TODAY AND 21Z SATURDAY.
SEVERE WEATHER POTENTIAL FOR SATURDAY INTO SATURDAY NIGHT...ALTHOUGH
THE 500-1000 J/KG OF CAPE IN THE AFTERNOON AND EVENING IS THIN...
EXTENDING UP TO AN EQUILIBRIUM LEVEL AROUND 250MB...THE
ENVIRONMENT FOR THE MOST PART IS UNCAPPED IN THE WARM SECTOR AHEAD
OF A SURFACE LOW COMING ACROSS NORTHERN IOWA. WARM SECTOR LOOKS TO
BE SITUATED MOSTLY SOUTH OF I-90. COMBINE THIS CAPE WITH A HIGHLY
SHEARED ENVIRONMENT NOTED BY 0-6KM SHEAR OF 40-50KT AND 0-1KM
SHEAR AROUND 25 KT YIELDS CONCERN OF DISCRETE TORNADIC SUPERCELLS
IN THE WARM SECTOR. HODOGRAPHS SUGGEST STRONGLY DOMINANT RIGHT
MOVING SUPERCELLS. DAMAGING WINDS WOULD BE A CONCERN TOO GIVEN THE
SHEAR. THIN CAPE PLUS RELATIVELY HIGH FREEZING LEVELS FOR THIS
TIME OF YEAR (AROUND 11000 FT) SHOULD PRECLUDE MUCH OF A LARGE
HAIL HAZARD. OVERALL...HIGHER SEVERE THREAT SHOULD EXIST SOUTH OF
THE FORECAST AREA WHERE CAPE AND DYNAMIC FORCING IS GREATER.
SWODY2 SEVERE WEATHER PROBABILITIES DEPICT THIS WELL. IT SHOULD BE
STRESSED THAT ANY UNEXPECTED SUNSHINE ON SATURDAY COULD
DRAMATICALLY INCREASE THE SEVERE WEATHER POTENTIAL. PRESENT
FORECASTS PORTRAY A MORE LIKELY CLOUDY SCENARIO.
SUNDAY AND SUNDAY NIGHT...MODELS ARE PRETTY QUICK IN EJECTING THE
NEGATIVE TILT SHORTWAVE AND THE ASSOCIATED SURFACE SYSTEM AWAY FROM
THE AREA. BY 00Z MONDAY...BOTH FEATURES SHOULD BE NEAR LAKE HURON.
THEREFORE...AFTER SOME DEFORMATION PRECIPITATION ON THE BACK SIDE OF
THE SYSTEM AFFECTS THE AREA IN THE MORNING...ESPECIALLY ACROSS
WISCONSIN...ANTICIPATING CONDITIONS TO DRY OUT FOR THE AFTERNOON.
UPPER TROUGHING DOES LINGER OVER THE AREA THROUGH SUNDAY NIGHT...
AIDED BY A FEW PACIFIC SHORTWAVES DROPPING IN BEHIND THE NEGATIVELY
TILTED SHORTWAVE. HOWEVER...AT MOST IT LOOKS LIKE THESE WOULD BRING
CLOUDS. DESPITE BEING IN COLD ADVECTION IN THE WAKE OF SUNDAYS
SYSTEM...850MB TEMPS ONLY FALL TO 2-4C. COMBINE THIS WITH SOME
AFTERNOON SUN SHOULD BOOST HIGHS INTO THE MID 50S TO LOW
60S...WARMEST WEST OF THE MISSISSIPPI RIVER WHERE THE MOST SUN IS
EXPECTED. COULD BE A COOL NIGHT SUNDAY NIGHT WITH A SURFACE RIDGE
BUILDING IN...BUT IT WILL ALL DEPEND ON THE CLOUDS. HAVE LEANED
TOWARDS A BLEND OF GUIDANCE WITH A KNOCK DOWN IN TEMPS FOR THE
TYPICAL COOLER SPOTS. MAY HAVE TO KEEP AN EYE ON VALLEY FOG
POTENTIAL IF THE SURFACE RIDGE BUILDS IN A LITTLE FASTER AND SKIES
STAY MOSTLY CLEAR.
.LONG TERM...MONDAY THROUGH THURSDAY NIGHT
258 AM CDT FRI OCT 12 2012
12.00Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES PORTRAY YET ANOTHER
PATTERN CHANGE DURING THE LONG TERM PERIOD...FORECASTING TROUGHING
ACROSS THE NORTHERN PLAINS INTO THE WESTERN GREAT LAKES BY THURSDAY.
THIS IS SIMILAR TO WHAT WE HAVE JUST EXPERIENCED FOR THE PAST
WEEK...THOUGH THE AIR IN THE TROUGH IS NOT NEARLY AS COOL.
THE PERIOD BEGINS WITH A FAST WEST-NORTHWEST FLOW FROM THE PACIFIC
NORTHWEST INTO THE NORTHERN PLAINS. THERE ARE INDICATIONS OF A
SHORTWAVE RIDING THROUGH THIS FLOW AND AMPLIFYING A TROUGH OVER THE
NORTHERN PLAINS ON TUESDAY...CAUSING RIDGING TO DEVELOP OVER THE
FORECAST AREA. THUS...IT WOULD APPEAR MONDAY AND IN PARTICULAR
TUESDAY SHOULD BE THE WARM DAYS OF THE WEEK. 850MB TEMPS CLIMB TO
6-9C BY 00Z TUESDAY AND 8-11C BY 00Z WEDNESDAY. MAY NOT BE ABLE TO
REALIZE THE FULL WARMTH ON TUESDAY...THOUGH...AS WARM ADVECTION AND
DPVA FORCED CLOUDS AND PRECIPITATION SPREAD INTO THE AREA AHEAD OF
THE NORTHERN PLAINS TROUGH. THE NORTHERN PLAINS TROUGH IS THEN
SUGGESTED TO SHIFT EAST OVER THE AREA FOR WEDNESDAY INTO THURSDAY.
KEPT PRECIPITATION CHANCES GOING FOR WEDNESDAY INTO WEDNESDAY NIGHT
PER CONSENSUS...DUE TO A DECENT STRENGTH SHORTWAVE SUGGESTED TO DROP
INTO THE TROUGH. AS THE SHORTWAVE PUSHES OFF TO THE EAST FOR
THURSDAY...FOLLOWED A DRY FORECAST. AGAIN...TEMPERATURES WILL COOL
DOWN WEDNESDAY INTO THURSDAY AS 850MB TEMPS DROP TO 4-6C AND 2-4C
RESPECTIVELY. AFTER MONDAY THROUGH WEDNESDAY PROGGED TO MAINLY BE IN
THE 60S...THURSDAY LOOKS TO END UP THE 50S.
&&
.AVIATION...TODAY AND TONIGHT
603 AM CDT FRI OCT 12 2012
HIGH PRESSURE WILL BRING VFR CONDITIONS TO THE TAF SITES THROUGH
EARLY THIS EVENING. PLAN ON LIGHT AND VARIABLE WINDS THROUGH
MIDDAY...BEFORE THE HIGH SLIDES EAST AND LOW PRESSURE DEEPENS OVER
THE CENTRAL PLAINS. WINDS WILL BECOME SOUTH THIS AFTERNOON AT 8 TO
13 KTS. CLOUDS WILL BE ON THE INCREASE THIS EVENING AS A STRONG
LOW PRESSURE SYSTEM DEEPENS OVER THE CENTRAL PLAINS AND LIFTS
NORTHEAST INTO THE UPPER MISSISSIPPI RIVER VALLEY. SHOWERS AND
THUNDERSTORMS WILL OVERSPREAD THE TAF SITES AFTER 06Z TONIGHT.
PLAN ON CLOUD BASES LOWERING INTO THE 2 TO 3 KFT RANGE LATE
TONIGHT...WITH IFR CEILINGS POSSIBLE IN HEAVIER SHOWERS AND
STORMS. IN ADDITIONS...VISIBILITIES MAY BE REDUCED TO AROUND 4 SM
IN THE HEAVIER DOWNPOURS. WILL HAVE TO KEEP A CLOSE WATCH ON LOW
LEVEL WIND SHEAR TONIGHT. FORECAST SOUNDINGS SHOW WINDS
INCREASING TO AROUND 40 KTS AT 2KFT BY 03Z. IT APPEARS THAT
SURFACE WINDS WILL STAY IN THE 13 TO 17 KT RANGE OVERNIGHT...WITH
WINDS HOLDING JUST BELOW LOW LEVEL WIND SHEAR CRITERIA. PLAN ON
SHOWERS AND THUNDERSTORMS THROUGH MUCH OF THE DAY ON SATURDAY.
SOME OF THE STORMS MAY BECOME SEVERE WITH DAMAGING WINDS AND HEAVY
RAINFALL...MAINLY SOUTH OF INTERSTATE 90.
&&
.HYDROLOGY...TONIGHT THROUGH SUNDAY
258 AM CDT FRI OCT 12 2012
QPF WISE FOR THE TONIGHT THROUGH SUNDAY MORNING SYSTEM...REALLY HARD
TO SAY. THE MAXIMUM AREA SHOULD BE OVER THE SOUTHEASTERN 1/3 OF THE
FORECAST AREA...WHERE THE LONGEST PERIOD OF 850MB MOISTURE TRANSPORT
NOSES IN AND THEN GETS HIT BY THE DEFORMATION ON THE BACK SIDE OF
THE SYSTEM. PRECIPITABLE WATER VALUES CLIMB TO AROUND 1.5 INCHES OR
200-250 PERCENT OF NORMAL TONIGHT AND HOVER AROUND THERE INTO SUNDAY
MORNING. POTENTIAL IS DEFINITELY THERE TO GET 1 TO 2 INCHES FOR THE
ENTIRE TIME PERIOD...AS SUGGESTED BY HPC FORECASTS AND SREF
PROBABILITIES...WITH LOCALLY HIGHER AMOUNTS DUE TO THE CONVECTIVE
NATURE. IN FACT...THE LATEST 12.00Z ECMWF HAS UPWARDS OF 3-3.5
INCHES. THE LANDSCAPE AND RIVERS REALLY COULD USE THIS RAIN GIVEN
THE SEVERE TO EXTREME DROUGHT CONDITIONS IN PLACE. THEREFORE...NO
FLOODING IS ANTICIPATED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
258 AM CDT FRI OCT 12 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP
HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
348 AM CDT FRI OCT 12 2012
.UPDATE...
REGARDING THE LATEST 12.06Z NAM HANDLING OF THE SATURDAY INTO SUNDAY
SYSTEM...THE MODEL IS DEFINITELY AN OUTLIER SHOWING A MUCH SLOWER
PROGRESS EJECTING THE UPPER LOW COMPARED TO ALL OTHER 12.00Z
GUIDANCE. THE REASON IT IS SLOWER IS THAT THE LOW MERGES WITH THE
POTENT SHORTWAVE ROTATING AROUND IT AS THE SHORTWAVE CROSSES NEW
MEXICO INTO THE OKLAHOMA AND TEXAS PANHANDLES. WILL NOT MAKE ANY
CHANGES TO THE FORECAST BECAUSE OF THIS MODEL....BUT...SHOULD IT
VERIFY THE SEVERE RISK FOR SATURDAY AFTERNOON AND EVENING WOULD BE
ELIMINATED. IN ADDITION...THE NORTHWEST HALF OF THE FORECAST AREA
WOULD RECEIVE A LOT LESS RAIN. OF INTEREST...THE 08.12Z CANADIAN RUN
WAS ALMOST IDENTICAL TO THE LATEST 12.06Z NAM. SOME SIMILARITIES TOO
WITH THE 12.00Z CANADIAN TO THE 12.06Z NAM...BUT THE CANADIAN IS
FASTER AND CLOSER TO OTHER GUIDANCE SUCH AS THE GFS/ECMWF/UKMET.
&&
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
258 AM CDT FRI OCT 12 2012
MAIN FORECAST CONCERN IS ON SEVERE WEATHER POTENTIAL SATURDAY INTO
SATURDAY NIGHT.
CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A SPLIT FLOW PATTERN ACROSS NORTH AMERICA. IN THE NORTHERN
STREAM...WEAK RIDGING WAS NOTED OVER THE NORTHERN U.S. ROCKIES AND
THEN DOWNSTREAM TROUGHING OVER THE GREAT LAKES. IN THE SOUTHERN
STREAM...AN UPPER LOW WAS OVER SOUTHERN CALIFORNIA WITH RIDGING
BUILDING UP AHEAD OF IT ACROSS THE CENTRAL AND SOUTHERN PLAINS. OVER
THE FORECAST AREA...SATELLITE IMAGERY SHOWED SKIES HAVE CLEARED OUT
THANKS TO SUBSIDENCE AND DRYING IN THE WAKE OF THE GREAT LAKES
TROUGHING. ALSO REFLECTED OF THE SUBSIDENCE IS A 1030MB SURFACE HIGH
CENTERED NEAR MINNEAPOLIS. PRECIPITABLE WATER VALUES WERE QUITE DRY
ON THE 00Z MPX SOUNDING...0.17 INCHES OR 30 PERCENT NORMAL. SURFACE
DEWPOINTS ALSO REFLECTIVE OF THE DRYING...DOWN IN THE TEENS TO LOWER
20S. DECENT AMOUNT OF COLD AIR ACCOMPANYING THE SURFACE HIGH WITH
850MB TEMPS THAT DROPPED TO -4C AT MPX AT 00Z COMPARED TO +3C 12
HOURS EARLIER. TO THE SOUTH...A STATIONARY FRONTAL BOUNDARY WAS
POSITIONED FROM OKLAHOMA INTO THE OHIO RIVER VALLEY. SOUTH OF THIS
FRONT...PLENTIFUL MOISTURE WAS NOTED WITH SURFACE DEWPOINTS IN THE
MID 60S TO LOWER 70S ACROSS OKLAHOMA AND MUCH OF TEXAS. 00Z FORT
WORTH SOUNDING HAD A PRECIPITABLE WATER VALUE OF 1.6 INCHES OR 176
PERCENT OF NORMAL. 850MB PROFILER AND VWP DATA CURRENTLY SHOWS MUCH
OF THIS MOISTURE BEING ADVECTED INTO AND ALONG THE STATIONARY
FRONTAL BOUNDARY.
TODAY AND TONIGHT...MAJOR CHANGES LOOK TO OCCUR IN THE WEATHER
PATTERN ACROSS THE FORECAST AREA DURING THIS TIME. THE UPPER LOW IN
CALIFORNIA MODELS ARE ALL IN GOOD AGREEMENT LIFTING IT OUT INTO
NORTHEAST COLORADO BY 12Z SATURDAY. IN RESPONSE TO THIS EJECTION THE
SUBTROPICAL RIDGING BUILDING OVER THE CENTRAL AND SOUTHERN PLAINS
GETS PULLED NORTHWARD INTO THE FORECAST AREA. AS A RESULT...THIS
HIGH PRESSURE BUILDING INTO THE FORECAST AREA RIGHT NOW AT THE
SURFACE WILL NOT HANG AROUND LONG. IN FACT...BY 00Z...15-20
SOUTHERLY 925MB WINDS ARE PROGGED AS THE HIGH SHIFTS OVER LAKE ERIE.
WE SHOULD SEE PLENTY OF SUN TODAY BEING UNDER THE INFLUENCE OF DRY
AIR NOTED ON THE 00Z MPX SOUNDING. 850MB TEMPS AT 18Z AROUND 1C IN
NORTHEAST IOWA TO -4C IN TAYLOR COUNTY SUGGESTS HIGHS FROM THE UPPER
40S TO MID 50S...COOLEST AS EXPECTED IN TAYLOR COUNTY. THINGS GET A
LITTLE MORE INTERESTING TONIGHT AS 850MB MOISTURE TRANSPORT KICKS
INTO HIGH GEAR AHEAD OF THE EJECTING UPPER LOW. 850MB WINDS
THEMSELVES ARE PROGGED TO INCREASE TO 35 TO 50 KT FROM THE SOUTHERN
PLAINS INTO THE FORECAST AREA BY 06Z...HELPING TO BRING UP THE
MOISTURE CURRENTLY SEEN ACROSS OKLAHOMA AND TEXAS. THIS RAPID
INCREASE IN MOISTURE WILL LEAD TO PRECIPITATION DEVELOPMENT...
PERHAPS AS EARLY AS 03Z AS SUGGESTED BY THE 12.00Z NAM. MORE LIKELY
IS TO HAVE WIDESPREAD SHOWERS ACROSS THE FORECAST AREA AFTER 06Z.
THUNDERSTORMS ARE ALSO EXPECTED WITH THIS ACTIVITY WITH MODELS
SHOWING UPWARDS OF 600 J/KG OF MUCAPE...MOSTLY ROOTED AT OR ABOVE
850MB PER CROSS-SECTIONS...ACCOMPANYING THE MOISTURE TRANSPORT. IN
ADDITION TO THE MOISTURE ADVECTION...850MB TEMPS ARE GOING TO SHOOT
UP...REACHING AROUND 12C BY 12Z. AS SUCH...ANTICIPATING LOWS IN THE
EVENING WITH TEMPERATURES RISING THEREAFTER.
SATURDAY AND SATURDAY NIGHT...THIS PERIOD HAS BEEN INTERESTING TO
WATCH OVER THE PAST SEVERAL DAYS WITH RESPECT TO WHAT HAPPENS WITH
THE UPPER LOW. ALL MODELS EXCLUDING THE NAM HAVE HAD ISSUES WITH THE
TRACK AND SPEED. HOWEVER...THERE IS A STRONG CONSENSUS NOW THAT THIS
UPPER LOW IS GOING TO TRACK EAST INTO SOUTHERN IOWA BY 12Z SUNDAY
AND TAKE ON A NEGATIVE TILT. MUCH OF THIS IS CAUSED BY A POTENT
SHORTWAVE HANGING BACK FROM THE UPPER LOW CROSSING THE SOUTHERN
PLAINS. THIS HAS BIG IMPLICATIONS FOR THE FORECAST AREA AS IT
DICTATES THE TRACK OF THE BEST PV ADVECTION...WHICH NOW STAYS MOSTLY
SOUTH OF THE AREA UNTIL MAYBE 12Z SUNDAY SOUTH OF I-90. STILL...
THERE IS PLENTY OF FORCING FOR PRECIPITATION. ON SATURDAY...THE
FORCING REMAINS THAT PERSISTENT STRONG 850MB MOISTURE TRANSPORT ZONE
WITH THE NOSE INTO THE FORECAST AREA. NOTE THAT THE ZONE DOES SLOWLY
SHIFT EAST IN RESPONSE TO THE APPROACHING UPPER LOW. AS SUCH...
PRECIPITATION MAY DIMINISH IN THE AFTERNOON ACROSS MINNESOTA.
PERSISTENT ADVECTION OF INSTABILITY WITHIN THE MOISTURE TRANSPORT...
WHICH SHOULD INCREASE THROUGH THE DAY AS THE AIRMASS SOUTH OF THE
AREA HEATS UP...SUGGESTS QUITE A BIT OF THUNDERSTORM ACTIVITY. BY
21Z AND CONTINUING THROUGH THE EVENING...500-1000 J/KG OF MUCAPE IS
PROGGED OVER THE FORECAST AREA...HIGHEST SOUTH OF I-90.
PRECIPITATION OVERALL LOOKS PRETTY GOOD FOR MOST OF THE AREA
SATURDAY NIGHT TOO...DUE TO A COMBINATION OF INCREASING LOW TO MID
LEVEL FRONTOGENESIS AND RIGHT ENTRANCE REGION SUPPORT FROM AN UPPER
JET DEVELOPING OVER UPPER MICHIGAN. NORTHWEST SECTIONS OF THE AREA
COULD BE ON THE EDGE OF THE PRECIPITATION... THOUGH...AS INDICATED
BY THE 12.00Z NAM AND AS SUCH SLIGHT LOWER CHANCES ARE PRESENT
THERE. GENERALLY FOLLOWED A BLEND OF GUIDANCE FOR HIGHS AND LOWS.
ONE SIDE NOTE WHICH REFLECTS THE CHANGE IN AIRMASSES...MOST
LOCATIONS WILL SEE A DEWPOINT JUMP OF 30 TO 40 DEGREES IN 24 HOURS
BETWEEN 21Z TODAY AND 21Z SATURDAY.
SEVERE WEATHER POTENTIAL FOR SATURDAY INTO SATURDAY NIGHT...ALTHOUGH
THE 500-1000 J/KG OF CAPE IN THE AFTERNOON AND EVENING IS THIN...
EXTENDING UP TO AN EQUILIBRIUM LEVEL AROUND 250MB...THE
ENVIRONMENT FOR THE MOST PART IS UNCAPPED IN THE WARM SECTOR AHEAD
OF A SURFACE LOW COMING ACROSS NORTHERN IOWA. WARM SECTOR LOOKS TO
BE SITUATED MOSTLY SOUTH OF I-90. COMBINE THIS CAPE WITH A HIGHLY
SHEARED ENVIRONMENT NOTED BY 0-6KM SHEAR OF 40-50KT AND 0-1KM
SHEAR AROUND 25 KT YIELDS CONCERN OF DISCRETE TORNADIC SUPERCELLS
IN THE WARM SECTOR. HODOGRAPHS SUGGEST STRONGLY DOMINANT RIGHT
MOVING SUPERCELLS. DAMAGING WINDS WOULD BE A CONCERN TOO GIVEN THE
SHEAR. THIN CAPE PLUS RELATIVELY HIGH FREEZING LEVELS FOR THIS
TIME OF YEAR (AROUND 11000 FT) SHOULD PRECLUDE MUCH OF A LARGE
HAIL HAZARD. OVERALL...HIGHER SEVERE THREAT SHOULD EXIST SOUTH OF
THE FORECAST AREA WHERE CAPE AND DYNAMIC FORCING IS GREATER.
SWODY2 SEVERE WEATHER PROBABILITIES DEPICT THIS WELL. IT SHOULD BE
STRESSED THAT ANY UNEXPECTED SUNSHINE ON SATURDAY COULD
DRAMATICALLY INCREASE THE SEVERE WEATHER POTENTIAL. PRESENT
FORECASTS PORTRAY A MORE LIKELY CLOUDY SCENARIO.
SUNDAY AND SUNDAY NIGHT...MODELS ARE PRETTY QUICK IN EJECTING THE
NEGATIVE TILT SHORTWAVE AND THE ASSOCIATED SURFACE SYSTEM AWAY FROM
THE AREA. BY 00Z MONDAY...BOTH FEATURES SHOULD BE NEAR LAKE HURON.
THEREFORE...AFTER SOME DEFORMATION PRECIPITATION ON THE BACK SIDE OF
THE SYSTEM AFFECTS THE AREA IN THE MORNING...ESPECIALLY ACROSS
WISCONSIN...ANTICIPATING CONDITIONS TO DRY OUT FOR THE AFTERNOON.
UPPER TROUGHING DOES LINGER OVER THE AREA THROUGH SUNDAY NIGHT...
AIDED BY A FEW PACIFIC SHORTWAVES DROPPING IN BEHIND THE NEGATIVELY
TILTED SHORTWAVE. HOWEVER...AT MOST IT LOOKS LIKE THESE WOULD BRING
CLOUDS. DESPITE BEING IN COLD ADVECTION IN THE WAKE OF SUNDAYS
SYSTEM...850MB TEMPS ONLY FALL TO 2-4C. COMBINE THIS WITH SOME
AFTERNOON SUN SHOULD BOOST HIGHS INTO THE MID 50S TO LOW
60S...WARMEST WEST OF THE MISSISSIPPI RIVER WHERE THE MOST SUN IS
EXPECTED. COULD BE A COOL NIGHT SUNDAY NIGHT WITH A SURFACE RIDGE
BUILDING IN...BUT IT WILL ALL DEPEND ON THE CLOUDS. HAVE LEANED
TOWARDS A BLEND OF GUIDANCE WITH A KNOCK DOWN IN TEMPS FOR THE
TYPICAL COOLER SPOTS. MAY HAVE TO KEEP AN EYE ON VALLEY FOG
POTENTIAL IF THE SURFACE RIDGE BUILDS IN A LITTLE FASTER AND SKIES
STAY MOSTLY CLEAR.
.LONG TERM...MONDAY THROUGH THURSDAY NIGHT
258 AM CDT FRI OCT 12 2012
12.00Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES PORTRAY YET ANOTHER
PATTERN CHANGE DURING THE LONG TERM PERIOD...FORECASTING TROUGHING
ACROSS THE NORTHERN PLAINS INTO THE WESTERN GREAT LAKES BY THURSDAY.
THIS IS SIMILAR TO WHAT WE HAVE JUST EXPERIENCED FOR THE PAST
WEEK...THOUGH THE AIR IN THE TROUGH IS NOT NEARLY AS COOL.
THE PERIOD BEGINS WITH A FAST WEST-NORTHWEST FLOW FROM THE PACIFIC
NORTHWEST INTO THE NORTHERN PLAINS. THERE ARE INDICATIONS OF A
SHORTWAVE RIDING THROUGH THIS FLOW AND AMPLIFYING A TROUGH OVER THE
NORTHERN PLAINS ON TUESDAY...CAUSING RIDGING TO DEVELOP OVER THE
FORECAST AREA. THUS...IT WOULD APPEAR MONDAY AND IN PARTICULAR
TUESDAY SHOULD BE THE WARM DAYS OF THE WEEK. 850MB TEMPS CLIMB TO
6-9C BY 00Z TUESDAY AND 8-11C BY 00Z WEDNESDAY. MAY NOT BE ABLE TO
REALIZE THE FULL WARMTH ON TUESDAY...THOUGH...AS WARM ADVECTION AND
DPVA FORCED CLOUDS AND PRECIPITATION SPREAD INTO THE AREA AHEAD OF
THE NORTHERN PLAINS TROUGH. THE NORTHERN PLAINS TROUGH IS THEN
SUGGESTED TO SHIFT EAST OVER THE AREA FOR WEDNESDAY INTO THURSDAY.
KEPT PRECIPITATION CHANCES GOING FOR WEDNESDAY INTO WEDNESDAY NIGHT
PER CONSENSUS...DUE TO A DECENT STRENGTH SHORTWAVE SUGGESTED TO DROP
INTO THE TROUGH. AS THE SHORTWAVE PUSHES OFF TO THE EAST FOR
THURSDAY...FOLLOWED A DRY FORECAST. AGAIN...TEMPERATURES WILL COOL
DOWN WEDNESDAY INTO THURSDAY AS 850MB TEMPS DROP TO 4-6C AND 2-4C
RESPECTIVELY. AFTER MONDAY THROUGH WEDNESDAY PROGGED TO MAINLY BE IN
THE 60S...THURSDAY LOOKS TO END UP THE 50S.
&&
.AVIATION...
1025 PM CDT THU OCT 11 2012
HIGH PRESSURE BUILDS IN FROM THE NORTHERN PLAINS OVERNIGHT...WITH
THE HIGH OVERHEAD BY 12Z FRI. CLEAR SKIES WITH A LIGHT WIND WILL
RESULT. IT WOULD BE A GREAT SETUP FOR RIVER VALLEY FOG...EXCEPT THE
T/TD SPREAD IS LARGE /25 DEGREES AT 02Z/ AND WILL LIKELY REMAIN THAT
WAY OVERNIGHT. IN ADDITION...DRIER AIR IS ADVECTING IN FROM THE
NORTHWEST. SO...DON/T EXPECT A FG IMPACT AT KLSE FRI MORNING.
THE HIGH WILL EXIT QUICKLY EAST ON FRI...WITH THE WINDS GRADUALLY
SHIFTING TO THE SOUTH AND INCREASING LATER IN THE DAY. CLOUDS WILL
BE ON THE INCREASE FRIDAY NIGHT AS LOW LEVEL THERMODYNAMICS AND
INCREASING SATURATION PUSH IN FROM THE SOUTH/SOUTHWEST...AHEAD OF A
LOW PRESSURE SYSTEM/COLD FRONT APPROACHING FROM THE WEST. AREAS OF
-SHRA WILL LIKELY DEVELOP FROM THE FORCING OVERNIGHT FRI...WITH SAT
LOOKING LIKE A WET DAY. ENOUGH FORCING AND INSTABILITY THAT A FEW
THUNDERSTORMS WILL BE POSSIBLE. EXPECT CIGS TO DROP INTO THE MVFR
RANGE AROUND 12Z SAT OR SHORTLY AFTER...WITH SOME VSBY RESTRICTIONS
IN THE RAIN.
&&
.HYDROLOGY...TONIGHT THROUGH SUNDAY
258 AM CDT FRI OCT 12 2012
QPF WISE FOR THE TONIGHT THROUGH SUNDAY MORNING SYSTEM...REALLY HARD
TO SAY. THE MAXIMUM AREA SHOULD BE OVER THE SOUTHEASTERN 1/3 OF THE
FORECAST AREA...WHERE THE LONGEST PERIOD OF 850MB MOISTURE TRANSPORT
NOSES IN AND THEN GETS HIT BY THE DEFORMATION ON THE BACK SIDE OF
THE SYSTEM. PRECIPITABLE WATER VALUES CLIMB TO AROUND 1.5 INCHES OR
200-250 PERCENT OF NORMAL TONIGHT AND HOVER AROUND THERE INTO SUNDAY
MORNING. POTENTIAL IS DEFINITELY THERE TO GET 1 TO 2 INCHES FOR THE
ENTIRE TIME PERIOD...AS SUGGESTED BY HPC FORECASTS AND SREF
PROBABILITIES...WITH LOCALLY HIGHER AMOUNTS DUE TO THE CONVECTIVE
NATURE. IN FACT...THE LATEST 12.00Z ECMWF HAS UPWARDS OF 3-3.5
INCHES. THE LANDSCAPE AND RIVERS REALLY COULD USE THIS RAIN GIVEN
THE SEVERE TO EXTREME DROUGHT CONDITIONS IN PLACE. THEREFORE...NO
FLOODING IS ANTICIPATED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
258 AM CDT FRI OCT 12 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....RIECK
HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
258 AM CDT FRI OCT 12 2012
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
258 AM CDT FRI OCT 12 2012
MAIN FORECAST CONCERN IS ON SEVERE WEATHER POTENTIAL SATURDAY INTO
SATURDAY NIGHT.
CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A SPLIT FLOW PATTERN ACROSS NORTH AMERICA. IN THE NORTHERN
STREAM...WEAK RIDGING WAS NOTED OVER THE NORTHERN U.S. ROCKIES AND
THEN DOWNSTREAM TROUGHING OVER THE GREAT LAKES. IN THE SOUTHERN
STREAM...AN UPPER LOW WAS OVER SOUTHERN CALIFORNIA WITH RIDGING
BUILDING UP AHEAD OF IT ACROSS THE CENTRAL AND SOUTHERN PLAINS. OVER
THE FORECAST AREA...SATELLITE IMAGERY SHOWED SKIES HAVE CLEARED OUT
THANKS TO SUBSIDENCE AND DRYING IN THE WAKE OF THE GREAT LAKES
TROUGHING. ALSO REFLECTED OF THE SUBSIDENCE IS A 1030MB SURFACE HIGH
CENTERED NEAR MINNEAPOLIS. PRECIPITABLE WATER VALUES WERE QUITE DRY
ON THE 00Z MPX SOUNDING...0.17 INCHES OR 30 PERCENT NORMAL. SURFACE
DEWPOINTS ALSO REFLECTIVE OF THE DRYING...DOWN IN THE TEENS TO LOWER
20S. DECENT AMOUNT OF COLD AIR ACCOMPANYING THE SURFACE HIGH WITH
850MB TEMPS THAT DROPPED TO -4C AT MPX AT 00Z COMPARED TO +3C 12
HOURS EARLIER. TO THE SOUTH...A STATIONARY FRONTAL BOUNDARY WAS
POSITIONED FROM OKLAHOMA INTO THE OHIO RIVER VALLEY. SOUTH OF THIS
FRONT...PLENTIFUL MOISTURE WAS NOTED WITH SURFACE DEWPOINTS IN THE
MID 60S TO LOWER 70S ACROSS OKLAHOMA AND MUCH OF TEXAS. 00Z FORT
WORTH SOUNDING HAD A PRECIPITABLE WATER VALUE OF 1.6 INCHES OR 176
PERCENT OF NORMAL. 850MB PROFILER AND VWP DATA CURRENTLY SHOWS MUCH
OF THIS MOISTURE BEING ADVECTED INTO AND ALONG THE STATIONARY
FRONTAL BOUNDARY.
TODAY AND TONIGHT...MAJOR CHANGES LOOK TO OCCUR IN THE WEATHER
PATTERN ACROSS THE FORECAST AREA DURING THIS TIME. THE UPPER LOW IN
CALIFORNIA MODELS ARE ALL IN GOOD AGREEMENT LIFTING IT OUT INTO
NORTHEAST COLORADO BY 12Z SATURDAY. IN RESPONSE TO THIS EJECTION THE
SUBTROPICAL RIDGING BUILDING OVER THE CENTRAL AND SOUTHERN PLAINS
GETS PULLED NORTHWARD INTO THE FORECAST AREA. AS A RESULT...THIS
HIGH PRESSURE BUILDING INTO THE FORECAST AREA RIGHT NOW AT THE
SURFACE WILL NOT HANG AROUND LONG. IN FACT...BY 00Z...15-20
SOUTHERLY 925MB WINDS ARE PROGGED AS THE HIGH SHIFTS OVER LAKE ERIE.
WE SHOULD SEE PLENTY OF SUN TODAY BEING UNDER THE INFLUENCE OF DRY
AIR NOTED ON THE 00Z MPX SOUNDING. 850MB TEMPS AT 18Z AROUND 1C IN
NORTHEAST IOWA TO -4C IN TAYLOR COUNTY SUGGESTS HIGHS FROM THE UPPER
40S TO MID 50S...COOLEST AS EXPECTED IN TAYLOR COUNTY. THINGS GET A
LITTLE MORE INTERESTING TONIGHT AS 850MB MOISTURE TRANSPORT KICKS
INTO HIGH GEAR AHEAD OF THE EJECTING UPPER LOW. 850MB WINDS
THEMSELVES ARE PROGGED TO INCREASE TO 35 TO 50 KT FROM THE SOUTHERN
PLAINS INTO THE FORECAST AREA BY 06Z...HELPING TO BRING UP THE
MOISTURE CURRENTLY SEEN ACROSS OKLAHOMA AND TEXAS. THIS RAPID
INCREASE IN MOISTURE WILL LEAD TO PRECIPITATION DEVELOPMENT...
PERHAPS AS EARLY AS 03Z AS SUGGESTED BY THE 12.00Z NAM. MORE LIKELY
IS TO HAVE WIDESPREAD SHOWERS ACROSS THE FORECAST AREA AFTER 06Z.
THUNDERSTORMS ARE ALSO EXPECTED WITH THIS ACTIVITY WITH MODELS
SHOWING UPWARDS OF 600 J/KG OF MUCAPE...MOSTLY ROOTED AT OR ABOVE
850MB PER CROSS-SECTIONS...ACCOMPANYING THE MOISTURE TRANSPORT. IN
ADDITION TO THE MOISTURE ADVECTION...850MB TEMPS ARE GOING TO SHOOT
UP...REACHING AROUND 12C BY 12Z. AS SUCH...ANTICIPATING LOWS IN THE
EVENING WITH TEMPERATURES RISING THEREAFTER.
SATURDAY AND SATURDAY NIGHT...THIS PERIOD HAS BEEN INTERESTING TO
WATCH OVER THE PAST SEVERAL DAYS WITH RESPECT TO WHAT HAPPENS WITH
THE UPPER LOW. ALL MODELS EXCLUDING THE NAM HAVE HAD ISSUES WITH THE
TRACK AND SPEED. HOWEVER...THERE IS A STRONG CONSENSUS NOW THAT THIS
UPPER LOW IS GOING TO TRACK EAST INTO SOUTHERN IOWA BY 12Z SUNDAY
AND TAKE ON A NEGATIVE TILT. MUCH OF THIS IS CAUSED BY A POTENT
SHORTWAVE HANGING BACK FROM THE UPPER LOW CROSSING THE SOUTHERN
PLAINS. THIS HAS BIG IMPLICATIONS FOR THE FORECAST AREA AS IT
DICTATES THE TRACK OF THE BEST PV ADVECTION...WHICH NOW STAYS MOSTLY
SOUTH OF THE AREA UNTIL MAYBE 12Z SUNDAY SOUTH OF I-90. STILL...
THERE IS PLENTY OF FORCING FOR PRECIPITATION. ON SATURDAY...THE
FORCING REMAINS THAT PERSISTENT STRONG 850MB MOISTURE TRANSPORT ZONE
WITH THE NOSE INTO THE FORECAST AREA. NOTE THAT THE ZONE DOES SLOWLY
SHIFT EAST IN RESPONSE TO THE APPROACHING UPPER LOW. AS SUCH...
PRECIPITATION MAY DIMINISH IN THE AFTERNOON ACROSS MINNESOTA.
PERSISTENT ADVECTION OF INSTABILITY WITHIN THE MOISTURE TRANSPORT...
WHICH SHOULD INCREASE THROUGH THE DAY AS THE AIRMASS SOUTH OF THE
AREA HEATS UP...SUGGESTS QUITE A BIT OF THUNDERSTORM ACTIVITY. BY
21Z AND CONTINUING THROUGH THE EVENING...500-1000 J/KG OF MUCAPE IS
PROGGED OVER THE FORECAST AREA...HIGHEST SOUTH OF I-90.
PRECIPITATION OVERALL LOOKS PRETTY GOOD FOR MOST OF THE AREA
SATURDAY NIGHT TOO...DUE TO A COMBINATION OF INCREASING LOW TO MID
LEVEL FRONTOGENESIS AND RIGHT ENTRANCE REGION SUPPORT FROM AN UPPER
JET DEVELOPING OVER UPPER MICHIGAN. NORTHWEST SECTIONS OF THE AREA
COULD BE ON THE EDGE OF THE PRECIPITATION... THOUGH...AS INDICATED
BY THE 12.00Z NAM AND AS SUCH SLIGHT LOWER CHANCES ARE PRESENT
THERE. GENERALLY FOLLOWED A BLEND OF GUIDANCE FOR HIGHS AND LOWS.
ONE SIDE NOTE WHICH REFLECTS THE CHANGE IN AIRMASSES...MOST
LOCATIONS WILL SEE A DEWPOINT JUMP OF 30 TO 40 DEGREES IN 24 HOURS
BETWEEN 21Z TODAY AND 21Z SATURDAY.
SEVERE WEATHER POTENTIAL FOR SATURDAY INTO SATURDAY NIGHT...ALTHOUGH
THE 500-1000 J/KG OF CAPE IN THE AFTERNOON AND EVENING IS THIN...
EXTENDING UP TO AN EQUILIBRIUM LEVEL AROUND 250MB...THE
ENVIRONMENT FOR THE MOST PART IS UNCAPPED IN THE WARM SECTOR AHEAD
OF A SURFACE LOW COMING ACROSS NORTHERN IOWA. WARM SECTOR LOOKS TO
BE SITUATED MOSTLY SOUTH OF I-90. COMBINE THIS CAPE WITH A HIGHLY
SHEARED ENVIRONMENT NOTED BY 0-6KM SHEAR OF 40-50KT AND 0-1KM
SHEAR AROUND 25 KT YIELDS CONCERN OF DISCRETE TORNADIC SUPERCELLS
IN THE WARM SECTOR. HODOGRAPHS SUGGEST STRONGLY DOMINANT RIGHT
MOVING SUPERCELLS. DAMAGING WINDS WOULD BE A CONCERN TOO GIVEN THE
SHEAR. THIN CAPE PLUS RELATIVELY HIGH FREEZING LEVELS FOR THIS
TIME OF YEAR (AROUND 11000 FT) SHOULD PRECLUDE MUCH OF A LARGE
HAIL HAZARD. OVERALL...HIGHER SEVERE THREAT SHOULD EXIST SOUTH OF
THE FORECAST AREA WHERE CAPE AND DYNAMIC FORCING IS GREATER.
SWODY2 SEVERE WEATHER PROBABILITIES DEPICT THIS WELL. IT SHOULD BE
STRESSED THAT ANY UNEXPECTED SUNSHINE ON SATURDAY COULD
DRAMATICALLY INCREASE THE SEVERE WEATHER POTENTIAL. PRESENT
FORECASTS PORTRAY A MORE LIKELY CLOUDY SCENARIO.
SUNDAY AND SUNDAY NIGHT...MODELS ARE PRETTY QUICK IN EJECTING THE
NEGATIVE TILT SHORTWAVE AND THE ASSOCIATED SURFACE SYSTEM AWAY FROM
THE AREA. BY 00Z MONDAY...BOTH FEATURES SHOULD BE NEAR LAKE HURON.
THEREFORE...AFTER SOME DEFORMATION PRECIPITATION ON THE BACK SIDE OF
THE SYSTEM AFFECTS THE AREA IN THE MORNING...ESPECIALLY ACROSS
WISCONSIN...ANTICIPATING CONDITIONS TO DRY OUT FOR THE AFTERNOON.
UPPER TROUGHING DOES LINGER OVER THE AREA THROUGH SUNDAY NIGHT...
AIDED BY A FEW PACIFIC SHORTWAVES DROPPING IN BEHIND THE NEGATIVELY
TILTED SHORTWAVE. HOWEVER...AT MOST IT LOOKS LIKE THESE WOULD BRING
CLOUDS. DESPITE BEING IN COLD ADVECTION IN THE WAKE OF SUNDAYS
SYSTEM...850MB TEMPS ONLY FALL TO 2-4C. COMBINE THIS WITH SOME
AFTERNOON SUN SHOULD BOOST HIGHS INTO THE MID 50S TO LOW
60S...WARMEST WEST OF THE MISSISSIPPI RIVER WHERE THE MOST SUN IS
EXPECTED. COULD BE A COOL NIGHT SUNDAY NIGHT WITH A SURFACE RIDGE
BUILDING IN...BUT IT WILL ALL DEPEND ON THE CLOUDS. HAVE LEANED
TOWARDS A BLEND OF GUIDANCE WITH A KNOCK DOWN IN TEMPS FOR THE
TYPICAL COOLER SPOTS. MAY HAVE TO KEEP AN EYE ON VALLEY FOG
POTENTIAL IF THE SURFACE RIDGE BUILDS IN A LITTLE FASTER AND SKIES
STAY MOSTLY CLEAR.
.LONG TERM...MONDAY THROUGH THURSDAY NIGHT
258 AM CDT FRI OCT 12 2012
12.00Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES PORTRAY YET ANOTHER
PATTERN CHANGE DURING THE LONG TERM PERIOD...FORECASTING TROUGHING
ACROSS THE NORTHERN PLAINS INTO THE WESTERN GREAT LAKES BY THURSDAY.
THIS IS SIMILAR TO WHAT WE HAVE JUST EXPERIENCED FOR THE PAST
WEEK...THOUGH THE AIR IN THE TROUGH IS NOT NEARLY AS COOL.
THE PERIOD BEGINS WITH A FAST WEST-NORTHWEST FLOW FROM THE PACIFIC
NORTHWEST INTO THE NORTHERN PLAINS. THERE ARE INDICATIONS OF A
SHORTWAVE RIDING THROUGH THIS FLOW AND AMPLIFYING A TROUGH OVER THE
NORTHERN PLAINS ON TUESDAY...CAUSING RIDGING TO DEVELOP OVER THE
FORECAST AREA. THUS...IT WOULD APPEAR MONDAY AND IN PARTICULAR
TUESDAY SHOULD BE THE WARM DAYS OF THE WEEK. 850MB TEMPS CLIMB TO
6-9C BY 00Z TUESDAY AND 8-11C BY 00Z WEDNESDAY. MAY NOT BE ABLE TO
REALIZE THE FULL WARMTH ON TUESDAY...THOUGH...AS WARM ADVECTION AND
DPVA FORCED CLOUDS AND PRECIPITATION SPREAD INTO THE AREA AHEAD OF
THE NORTHERN PLAINS TROUGH. THE NORTHERN PLAINS TROUGH IS THEN
SUGGESTED TO SHIFT EAST OVER THE AREA FOR WEDNESDAY INTO THURSDAY.
KEPT PRECIPITATION CHANCES GOING FOR WEDNESDAY INTO WEDNESDAY NIGHT
PER CONSENSUS...DUE TO A DECENT STRENGTH SHORTWAVE SUGGESTED TO DROP
INTO THE TROUGH. AS THE SHORTWAVE PUSHES OFF TO THE EAST FOR
THURSDAY...FOLLOWED A DRY FORECAST. AGAIN...TEMPERATURES WILL COOL
DOWN WEDNESDAY INTO THURSDAY AS 850MB TEMPS DROP TO 4-6C AND 2-4C
RESPECTIVELY. AFTER MONDAY THROUGH WEDNESDAY PROGGED TO MAINLY BE IN
THE 60S...THURSDAY LOOKS TO END UP THE 50S.
&&
.AVIATION...
1025 PM CDT THU OCT 11 2012
HIGH PRESSURE BUILDS IN FROM THE NORTHERN PLAINS OVERNIGHT...WITH
THE HIGH OVERHEAD BY 12Z FRI. CLEAR SKIES WITH A LIGHT WIND WILL
RESULT. IT WOULD BE A GREAT SETUP FOR RIVER VALLEY FOG...EXCEPT THE
T/TD SPREAD IS LARGE /25 DEGREES AT 02Z/ AND WILL LIKELY REMAIN THAT
WAY OVERNIGHT. IN ADDITION...DRIER AIR IS ADVECTING IN FROM THE
NORTHWEST. SO...DON/T EXPECT A FG IMPACT AT KLSE FRI MORNING.
THE HIGH WILL EXIT QUICKLY EAST ON FRI...WITH THE WINDS GRADUALLY
SHIFTING TO THE SOUTH AND INCREASING LATER IN THE DAY. CLOUDS WILL
BE ON THE INCREASE FRIDAY NIGHT AS LOW LEVEL THERMODYNAMICS AND
INCREASING SATURATION PUSH IN FROM THE SOUTH/SOUTHWEST...AHEAD OF A
LOW PRESSURE SYSTEM/COLD FRONT APPROACHING FROM THE WEST. AREAS OF
-SHRA WILL LIKELY DEVELOP FROM THE FORCING OVERNIGHT FRI...WITH SAT
LOOKING LIKE A WET DAY. ENOUGH FORCING AND INSTABILITY THAT A FEW
THUNDERSTORMS WILL BE POSSIBLE. EXPECT CIGS TO DROP INTO THE MVFR
RANGE AROUND 12Z SAT OR SHORTLY AFTER...WITH SOME VSBY RESTRICTIONS
IN THE RAIN.
&&
.HYDROLOGY...TONIGHT THROUGH SUNDAY
258 AM CDT FRI OCT 12 2012
QPF WISE FOR THE TONIGHT THROUGH SUNDAY MORNING SYSTEM...REALLY HARD
TO SAY. THE MAXIMUM AREA SHOULD BE OVER THE SOUTHEASTERN 1/3 OF THE
FORECAST AREA...WHERE THE LONGEST PERIOD OF 850MB MOISTURE TRANSPORT
NOSES IN AND THEN GETS HIT BY THE DEFORMATION ON THE BACK SIDE OF
THE SYSTEM. PRECIPITABLE WATER VALUES CLIMB TO AROUND 1.5 INCHES OR
200-250 PERCENT OF NORMAL TONIGHT AND HOVER AROUND THERE INTO SUNDAY
MORNING. POTENTIAL IS DEFINITELY THERE TO GET 1 TO 2 INCHES FOR THE
ENTIRE TIME PERIOD...AS SUGGESTED BY HPC FORECASTS AND SREF
PROBABILITIES...WITH LOCALLY HIGHER AMOUNTS DUE TO THE CONVECTIVE
NATURE. IN FACT...THE LATEST 12.00Z ECMWF HAS UPWARDS OF 3-3.5
INCHES. THE LANDSCAPE AND RIVERS REALLY COULD USE THIS RAIN GIVEN
THE SEVERE TO EXTREME DROUGHT CONDITIONS IN PLACE. THEREFORE...NO
FLOODING IS ANTICIPATED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
258 AM CDT FRI OCT 12 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....RIECK
HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS MIAMI FL
415 AM EDT SUN OCT 14 2012
...HIGH RISK OF RIP CURRENTS ATLANTIC BEACHES/MINOR COASTAL
FLOODING POSSIBLE BEFORE WINDS RELAX THROUGHOUT THE DAY...
.DISCUSSION...THE PWAT ON THE MIAMI EVENING SOUNDING YESTERDAY WAS
ONLY 1.12 INCHES, BUT IT IS PROGGED TO INCREASE INTO THE 1.4-1.6
RANGE THIS AFTERNOON THROUGH MONDAY, BEFORE DRIER AIR INFILTRATES
SOUTH FL BEHIND A WEAK COLD FRONT MON NIGHT. THE RESULT IS THE
EXPECTATION OF SCATTERED SHOWERS, AND POSSIBLY A TSTORM OR TWO,
TODAY-MONDAY WITH THE FOCUS ALONG THE ATLANTIC COAST. THEN, AS A
DRIER AIRMASS ADVECTS INTO THE AREA MON NIGHT-TUE, LITTLE SHOWER
ACTIVITY IS EXPECTED. HOWEVER, WILL PLACE SLIGHT CHANCE EASTERN
HALF OF THE AREA AS THERE COULD BE JUST ENOUGH LOW LEVEL MOISTURE
TO SQUEEZE OUT A FEW SHOWERS ON A QUICK RETURN TO NE-E FLOW BEHIND
THE WEAK FRONTAL BOUNDARY...AS PER GFS/ECMWF MODEL LOW QPF FIELDS.
INSTABILITY INCREASES JUST SLIGHTLY TODAY-MON BUT STILL WEAK LAPSE
RATES. HOWEVER, CANNOT RULE OUT A TSTORM...AND HRRR SHOWS A COUPLE
OF ECHO TOPS TO 40KFT OVER THE SOUTHERN ATLANTIC AND SOUTHERN
INTERIOR OF SOUTH FL THIS AFTERNOON...SO WILL INCLUDE SLIGHT
CHANCE OF TSTORMS TODAY AND MONDAY.
A HIGH RISK OF RIP CURRENTS CONTINUES ALONG THE ATLANTIC BEACHES
TODAY. WINDS WILL GRADUALLY SUBSIDE, BUT THE HIGH RISK WILL PERSIST
THROUGH THE EVENING. MINOR COASTAL FLOODING WILL BE POSSIBLE,
ESPECIALLY AROUND HIGH TIDE AT AROUND SUNRISE THIS MORNING DUE TO
TIDES RUNNING ABOUT A HALF A FOOT ABOVE PREDICTED DUE TO THE STRONG
ONSHORE FLOW. SO WILL CONTINUE TO ADVERTISE THIS POTENTIAL.
SUBSIDING ONSHORE WINDS ALONG THE ATLANTIC COAST SHOULD SLIGHTLY
REDUCE THIS POTENTIAL INTO THE EARLY WORK WEEK, DESPITE TIDES
REMAINING HIGH DUE TO THE SPRING TIDE.
AGAIN, BEHIND THE FRONTAL PASSAGE MON NIGHT, A DRIER AIRMASS WILL
MOVE IN WITH RE-ENFORCING LOWER DEWPOINTS IN THE 60S AND JUST SLIGHT
RAIN CHANCES. A FEW SHOWERS WILL CONTINUE POSSIBLE ESPECIALLY
INTERIOR/EAST COAST THROUGH LATE WEEK. THEN ANOTHER STRONGER COLD
FRONT APPROACHES NEXT WEEKEND...AND MAY MOVE THROUGH, ALTHOUGH THE
LATEST GFS/ECMWF SHOW MUCH OF THE ENERGY NORTH OF OUR AREA. IN
OTHER WORDS, THEY`VE TRENDED LESS AGGRESSIVE WITH THE
FRONT, ESPECIALLY THE ECMWF MODEL. STILL, THERE LOOKS TO BE
ANOTHER COLD FRONTAL PASSAGE SOMETIME THIS WEEKEND. GIVEN TIMING
UNCERTAINTIES, MAINTAINED SLIGHT CHANCE OF SHOWERS THROUGH NEXT
WEEKEND. THE ECMWF SHOWS THE CLOSED MID/UPPER LOW A BIT FURTHER
SOUTH, PULLING UP HIGHER MOISTURE AND EVEN A POTENTIAL FOR TSTORMS
AHEAD/ALONG THE FRONT SATURDAY. WE CAN WATCH MODEL TRENDS. A LOT
OF UNCERTAINTY THIS FAR OUT.
&&
.MARINE...WILL CONTINUE THE SMALL CRAFT ADVISORY FOR THE OFFSHORE
GULF WATERS AND BISCAYNE BAY THIS MORNING, BUT DROPPED THE LAKE AS
OBS ARE BELOW 20 KT. THE SCA WILL CONTINUE FOR THE ATLANTIC TODAY,
AND THE PALM BEACH WATERS THROUGH 6Z TONIGHT DUE TO SEAS OF 7 FT
THROUGH THEN BEFORE SUBSIDING FURTHER AS WINDS CONTINUE TO RELAX
THROUGH THE DAY AND BEYOND.
&&
.FIRE WEATHER...NO CONCERNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 87 76 88 73 / 40 30 30 10
FORT LAUDERDALE 88 79 88 75 / 40 30 30 10
MIAMI 88 78 88 75 / 40 30 30 10
NAPLES 91 73 89 72 / 30 10 20 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH THIS EVENING FOR COASTAL BROWARD-
COASTAL MIAMI DADE-COASTAL PALM BEACH.
AM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR COASTAL
WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL OUT 20 NM-
WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL EXTENDING
FROM 20 NM TO THE TERRITORIAL WATERS OF THE BAHAMAS.
SMALL CRAFT ADVISORY UNTIL 2 AM EDT MONDAY FOR COASTAL WATERS
FROM JUPITER INLET TO DEERFIELD BEACH, FL OUT 20 NM-WATERS
FROM JUPITER INLET TO DEERFIELD BEACH, FL EXTENDING FROM 20
NM TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR BISCAYNE
BAY.
GM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR GULF
WATERS FROM CHOKOLOSKEE TO BONITA BEACH, FL EXTENDING FROM
20 TO 60 NM.
&&
$$
DISCUSSION/MARINE/FIRE...57/GREGORIA
AVIATION/RADAR...60/BD
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1239 AM EDT SUN OCT 14 2012
.SYNOPSIS...
HIGH PRESSURE WILL WEAKEN ACROSS THE AREA INTO EARLY MONDAY...
THEN GIVE WAY TO A COLD FRONT LATE MONDAY INTO MONDAY NIGHT.
WEAK HIGH PRESSURE WILL THEN PREVAIL THROUGH MID WEEK. ANOTHER
COLD FRONT IS EXPECTED TO APPROACH THE EAST COAST BY NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
ISENTROPIC LIFT IS STRONGEST ACROSS THE SOUTH WHERE IT HAS
MANIFESTED ITSELF INTO A STRATOCUMULUS DECK. EVEN A FEW SHOWERS
HAVE MADE IT ONSHORE ACROSS PARTS OF MCINTOSH AND LIBERTY
COUNTIES. 14/03Z RAP ISENTROPIC FIELDS INDICATE THE STRONGEST
ASSENT WILL REMAIN FOCUSED ACROSS SOUTHEAST GEORGIA FOR THE NEXT
FEW HOURS BEFORE DIMINISHING. MODIFIED POP AND SKY GRIDS TO DENOTE
GOING TRENDS AND TO FOCUS THE GREATEST COVERAGE OF CLOUDS AS WELL AS
ISOLATED SHOWERS ACROSS THE FAR SOUTH. LOWS WILL RANGE FROM THE
LOWER 50S WELL INLAND TO THE UPPER 60S/NEAR 70 AT THE BEACHES.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
SUNDAY...A STRONG SHORT WAVE FOUND MOVING NE FROM THE MID MS VALLEY
TO THE GREAT LAKES WILL CAUSE ITS ASSOCIATED SURFACE LOW PRESSURE TO
DEEPEN AS IT MOVES IN TANDEM NE WITH THE FEATURE ALOFT. THIS IN TURN
WILL FORCE EASTWARD THE NORTHERN PORTION OF HIGH PRESSURE THAT
STRETCHES FROM SOUTH OF NEW ENGLAND TO THE SE STATES. THE ASSOCIATED
RIDGE AXIS WILL HANG BACK TO THE WEST AND SW AND ALIGN ITSELF ACROSS
THE LOCAL CWFA DURING THE LATE MORNING AND AFTERNOON. AS THIS
TRANSPIRES THE LOW LEVEL FLOW WILL VEER AROUND TO THE EAST AND
SE...AND WHEN COMBINED WITH CONSIDERABLE WARM ADVECTION AS 850 MB
TEMPS CLIMB TO 13-14C...WE WILL EXPERIENCE A NOTICEABLY WARMER DAY.
WE WON/T GO AS HIGH AS THE LOW LEVEL THICKNESS FORECAST GIVEN THE
ONSHORE COMPONENT...BUT EVEN SO OUR MAX TEMPS AWAY FROM THE COOLER
COASTLINE WILL STILL REACH THE LOWER 80S. THE WEAK AND NEARBY
COASTAL TROUGH IN THE MORNING WILL DISSIPATE BY AFTERNOON...BUT
ITS CLOSE PROXIMITY AND WEAK ISENTROPIC MIGHT BE ENOUGH TO CAUSE A
FEW MORNING SHOWERS NEAR THE COAST. FOR THAT REASON WE/LL HOLD
ONTO 20 POPS BUT NO MORE SINCE THE MOISTURE DEPTH IS CONFINED TO
ONLY THE FIRST FEW THOUSAND FEET OF THE TROPOSPHERE.
SUNDAY NIGHT...THE INITIAL SHORT WAVE AND ITS SURFACE LOW WILL LIFT
NE INTO CANADA...WHILE ANOTHER STRONG SHORT WAVE DROPS SE AND
AMPLIFIES A TROUGH SOUTH TO THE LOWER MS VALLEY. THIS IN TURN SENDS
A COLD FRONT TOWARD THE APPALACHIAN MOUNTAINS LATE...AS HEIGHT FALLS
ALOFT WEAKENS THE SURFACE RIDGING ACROSS SOUTHERN SC AND SE GA. A
WEAK COASTAL TROUGH WILL TRY AND FORM ONCE THE ANTICYCLONIC FLOW
DIMINISHES ENOUGH...AND WITH A VEERING SYNOPTIC FLOW WE MIGHT SEE A
FEW ATLANTIC SHOWERS MAKE A RUN FOR COASTAL SECTIONS. ONCE AGAIN
THOUGH THE DEPTH OF THE MOISTURE IS LIMITED...SO RAIN CHANCES WILL
BE HELD UNDER 15 PERCENT. PROVIDED THERE IS NOT TOO MUCH CLOUD
COVER FROM OFF ATLANTIC...THERE LOOKS TO BE THE POTENTIAL FOR FOG.
DRY AIR ALOFT ATOP A MOIST BOUNDARY LAYER...LIGHT WIND FIELDS AND
FOG STABILITY INDICES LESS THAN 20 SUGGEST AT LEAST PATCHY FOG
FORMATION. MUCH OF THE VERTICAL WILL WARM AND HOLD TEMPS UP IN THE
LOWER-MIDDLE 60S INLAND FROM US-17 AND THE UPPER 60S TO NEAR 70 AT
THE SHORE.
MONDAY...AN AMPLIFIED MID AND UPPER MID LATITUDE TROUGH MOVES TOWARD
THE EASTERN SEABOARD...AND PUSHES THE COLD FRONT SE TOWARD THE AREA
AS IT CROSSES THE MOUNTAIN CHAIN. STEADY HEIGHT FALLS WILL BE IN
SYNC WITH LOW LEVEL WARM ADVECTION TO GENERATE FAIRLY STEEP LAPSE
RATES FOR MID OCTOBER. THAT ALONG WITH UPPER DIFLUENCE AS A RESULT
OF THE RIGHT ENTRANCE REGION OF THE UPPER JET NEARBY AND MOISTURE
INCREASING AHEAD OF THE FRONT POINTS TOWARD OUR BEST RAIN CHANCES OF
THE SHORT TERM PERIOD. SINCE LOW LEVEL CONVERGENCE IS LIMITED WITH A
DEEP WEST TO SW FLOW...POPS WILL RISE ONLY INTO THE 30-40 PERCENT
RANGE FOR ALL BUT THE SE CORNER OF THE CWFA...WHERE 20 POPS WILL
SUFFICE. DUE TO THE PROGRESSIVE NATURE OF THIS NEXT FRONTAL SYSTEM
AND THE SHORT DURATION OF MOISTURE FLUX...QPF VALUES WILL BE LOW.
THERE IS CERTAINLY THE RISK...ALBEIT SMALL...FOR ISOLATED STRONG OR
SEVERE T-STORMS IN THE AFTERNOON. ALONG WITH THE FAVORABLE LAPSE
RATES THERE IS ALSO 25-30 KT OF 0-6 KM BULK SHEAR...AND SBCAPES WILL
BE AS HIGH AS 1000-1500 J/KG. THE STRONGER UPDRAFTS MIGHT THEN BE
ABLE TO PRODUCE STRONG AND GUSTY WINDS AS THEY COLLAPSE. ALTHOUGH OUR
INSOLATION WILL BE REDUCED BY AN INCREASE IN CLOUD COVER...THIS IS
NEGATED AT LEAST SOMEWHAT BY GOOD WARM ADVECTION AND COMPRESSIONAL
HEATING OUT AHEAD OF THE COLD FRONT. BEFORE ANY RAINS MOVE IN WE
LOOK FOR MAX READINGS IN THE LOWER AND MIDDLE 80S...FAR ABOVE NORMAL
FOR THIS TIME OF YEAR.
MONDAY NIGHT...THE FRONT WILL QUICKLY PUSH THROUGH THE AREA BY
06Z...AND RAPID DRYING AND COLD ADVECTION WILL ENSUE. WE/LL SEE
TEMPS DROP QUICK AND STEADILY IN WAKE OF THE FRONT...FALLING TO THE
LOWER AND MIDDLE 50S WEST...AND UPPER 50S AND LOWER 60S EAST BY
MORNING.
TUESDAY...A WESTERLY FLOW WILL SET IN ALOFT BEHIND THE DEPARTING
SHORT WAVE TROUGH THAT MOVES INTO THE ATLANTIC...AND IS RESPONSIBLE
FOR CAPTURING TC RAFAEL AND LIFTING IT OFF TO THE NE AND EAST WELL
OUT IN THE ATLANTIC. WEAK CONTINENTAL HIGH PRESSURE IN THE OH/TN
VALLEYS WILL MOVE IN...GENERATING A COOLER AIR MASS ON A NORTHERLY
FLOW WITH TEMPS AT 850 MB ARE DOWN NEAR 8-10C. EVEN WITH FULL
SUNSHINE WE/LL BE LIMITED TO MAYBE THE MID AND UPPER 70S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THE CENTER OF WEAK HIGH PRESSURE WILL STEADILY SHIFT EASTWARD
THROUGH MID WEEK...BEFORE ANOTHER ROUND OF SHORTWAVE ENERGY SLIPS
FROM CENTRAL CANADA AND SPAWNS A ROBUST LOW SYSTEM OVER THE GREAT
LAKE REGION BY THURSDAY. THE TRAILING COLD FRONT WILL MOVE TOWARD
THE EAST COAST BY EARLY FRIDAY. HOWEVER...MOST DEEP MOISTURE AND
UPPER LEVEL ENERGY IS EXPECTED TO REMAIN DETACHED TO THE NORTH
WITH THE MAIN SYSTEM...SUGGESTING THAT THE FRONT COULD RUN OUT OF
STEAM UPON APPROACH TO THE FORECAST AREA. PREFER TO THUS MAINTAIN
A RATHER CONSERVATIVE POP SCHEME FOR THE EXTENDED PERIOD AND CAP
RAIN CHANCES BELOW 15 PERCENT WEDNESDAY THROUGH SATURDAY. HIGH
TEMPERATURES WILL RANGE FROM THE UPPER 70S NORTH TO AROUND 80
DEGREES NEAR THE ALTAMAHA RIVER IN SOUTHEAST GEORGIA. LOW
TEMPERATURES WILL GENERALLY FALL INTO THE 50S INLAND EACH
NIGHT...WITH SOME MID AND UPPER 40S LIKELY TUESDAY NIGHT UNDER IDEAL
RADIATIONAL COOLING CONDITIONS.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
VFR. LOW CHANCE FOR HIGH-END MVFR CIGS AT KSAV THROUGH
SUNRISE...BUT CIGS ARE EXPECTED TO REMAIN VFR. COULD ALSO SEE SOME
PATCHY GROUND FOG AT KCHS...BUT DO NOT ANTICIPATE ANY SIGNIFICANT
REDUCTIONS IN VISIBILITIES.
EXTENDED AVIATION OUTLOOK...MVFR OR LOWER CONDITIONS POSSIBLE IN
FOG SUNDAY NIGHT/MORNING MORNING. PERIODIC MVFR CONDITIONS POSSIBLE
IN SCATTERED SHRA/ISOLATED TSRA LATE MONDAY IN ASSOCIATION WITH A
COLD FRONT. VFR WEATHER WILL OTHERWISE PREVAIL.
&&
.MARINE...
OVERNIGHT...REPORTS FROM THE CHARLESTON HARBOR PILOT BOAT INDICATE
WINDS AND SEAS HAVE DIMINISHED BELOW SMALL CRAFT ADVISORY
THRESHOLDS ACROSS THE CHARLESTON COUNTY COASTAL WATERS. HAVE
CANCELLED THE ADVISORY FOR THESE WATERS. HOWEVER...IT REMAINS IN
FORCE ELSEWHERE.
SUNDAY AND SUNDAY NIGHT...HIGH PRESSURE FROM THE ATLANTIC AND
EXTENDING ACROSS THE LOCAL WATERS WILL STEADILY WEAKEN AS THE CORE
OF THE HIGH PULLS OUT TO THE EAST IN ADVANCE OF LOW PRESSURE MOVING
INTO THE GREAT LAKES STATES AND FAR SOUTHERN CANADA. WINDS WILL
STEADILY DIMINISH AS A RESULT...BUT SEAS WILL TAKE LONGER IN COMING
DOWN WITH LINGERING SWELL ENERGY. AS A RESULT WE STILL LOOK FOR 6
FOOTERS TO REMAIN ACROSS THE OUTER GA WATERS INTO THE FIRST PART OF
SUNDAY NIGHT...THUS A CONTINUATION OF THE SCA ACROSS AMZ374. THE
REST OF THE COASTAL WATERS WILL EXPERIENCE COMBINED SEAS AT 5 FEET
OR LESS.
MONDAY AND MONDAY NIGHT...WE/LL START THE PERIOD WITH EITHER A WEAK
PRESSURE PATTERN OR A WEAK COASTAL TROUGH...BEFORE THE SYNOPTIC
PATTERN CHANGES TO THE APPROACH AND EVENTUAL PASSAGE OF A COLD
FRONT. A LIGHT WIND REGIME IN ADVANCE OF THE FRONT WILL BE FOLLOWED
BY STRENGTHENING COLD ADVECTION THE SECOND PART OF MONDAY
NIGHT...CAUSING WINDS TO VEER FROM WEST AND SW AROUND TO THE NW AND
NORTH. SPEEDS WILL TAKE A SHARP TURN UPWARDS...REACHING 15 OR EVEN
20 KT LATE. WILL WILL GENERALLY BE AROUND 5 FT...A MIX OF BOTH
SWELLS AND WIND DRIVEN WAVES...BUT WE/LL NEED TO KEEP WATCH FOR
POSSIBLE 6 FOOTERS AGAIN ACROSS AMZ374.
TUESDAY...COLD ADVECTION IN THE MORNING WILL DROP OFF FOR THE
AFTERNOON...AND THAT ALONG WITH A MUCH MORE RELAXED PRESSURE
GRADIENT TO DEVELOP AS THE PRESSURE DIFFERENCE BETWEEN TC RAFAEL AND
WEAK HIGH PRESSURE TO THE WEST DIMINISHES. WE/LL BE CLOSE TO SCA
CONDITIONS...ESPECIALLY ACROSS AMZ374...ESPECIALLY IF ANY SWELLS
FROM RAFAEL ARE ABLE TO ARRIVE BEFORE THAT SYSTEM TURNS OFF TO THE
NE AND EAST.
WEDNESDAY...WEAK HIGH PRESSURE SETTLES ACROSS THE MARINE AREA.
ALTHOUGH WINDS WON/T BE A CONCERN...SEAS WILL REMAIN ELEVATED WITH
SWELL ENERGY STILL PERSISTING.
RIP CURRENTS...WITH STRONGER THAN EXPECTED WINDS ALONG THE
CHARLESTON COUNTY COAST HAVE RAISED THEIR RISK TO HIGH FOR THE
REST OF THE DAY. ELSEWHERE A HIGH RISK REMAINS IN EFFECT.
ALTHOUGH THERE IS A MUCH LIGHTER ONSHORE FLOW FOR SUNDAY...GIVEN
THAT SMALL SWELLS WILL PERSIST AND WE HAVE SOME ENHANCEMENT FROM
THE UPCOMING NEW MOON AND PERIGEE...THE RISK FOR RIP CURRENTS IS
STILL ELEVATED AND IN THE MODERATE RANGE.
&&
.TIDES/COASTAL FLOODING...
TIDE LEVELS WILL REMAIN ELEVATED INTO THE MIDDLE OF NEXT WEEK
MAINLY DUE TO THE PERIGEAN SPRING TIDE. THERE IS A GOOD CHANCE
THAT TIDES WILL BE HIGH ENOUGH TO PRODUCE SOME INUNDATION OF
SALTWATER IN NORMALLY PRONE AREAS EITHER SUNDAY OR MONDAY
MORNING...AND CONTINUING THROUGH AT LEAST WEDNESDAY. AS A
RESULT...COASTAL FLOOD ADVISORIES WILL LIKELY BE NEEDED FOR AT
LEAST THE TIMES AROUND THE MORNING HIGH TIDE EACH DAY DURING THIS
TIME.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EDT EARLY THIS MORNING FOR
AMZ352-354.
SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR AMZ374.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
430 AM EDT SUN OCT 14 2012
.UPDATE...
THE SYNOPSIS...NEAR TERM...SHORT TERM AND LONG TERM SECTIONS HAVE
BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 325 AM EDT SUN OCT 14 2012
LOW PRESSURE CENTERED OUT IN THE PLAINS WILL CONTINUE TO MOVE
TOWARDS THE GREAT LAKES REGION FOR THE END OF THE WEEKEND. A STRONG
COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL CROSS CENTRAL INDIANA
TODAY BRINGING THE CHANCE FOR SHOWERS AND THUNDERSTORMS TO THE
AREA...WITH THE POSSIBILITY OF STRONG TO SEVERE STORMS.
ADDITIONALLY...STRONG SOUTHERLY WINDS WITH GUSTS OVER 40 MPH ARE
POSSIBLE THIS AFTERNOON AS THE LOW CONTINUES TO STRENGTHEN.
HIGH PRESSURE WILL RETURN TO THE AREA ON MONDAY WITH DRY CONDITIONS
EXPECTED TO CONTINUE FOR ROUGHLY THE FIRST HALF OF THE WORK WEEK.
ANOTHER SYSTEM IS EXPECTED TO IMPACT THE REGION MIDWEEK BRINGING
ADDITIONAL CHANCES FOR PRECIPITATION HEADING INTO NEXT WEEKEND.
&&
.NEAR TERM /TODAY/...
ISSUED AT 325 AM EDT SUN OCT 14 2012
FORECAST CONCERNS FOR THE NEAR TERM CONTINUE TO BE THE STRONG WINDS
EXPECTED THIS AFTERNOON AS WELL AS THE POTENTIAL FOR SEVERE STORMS
AS A COLD FRONT PASSES THROUGH THE AREA.
WINDS ARE NOT AS STRONG THIS MORNING AS PREVIOUSLY FORECAST WITH THE
PRESSURE GRADIENT TAKING A BIT LONGER TO TIGHTEN UP AS THE LOW IS
SLOWER TO DEEPEN THAN EXPECTED. CURRENT THINKING IS THAT THE HIGHEST
SUSTAINED SPEEDS (20-25 MPH) AND ASSOCIATED GUSTS (40-45 MPH) WILL
NOT MIX DOWN UNTIL CLOSER TO 15Z...RATHER THAN AS EARLY AS 12Z.
THEREFORE...WILL DELAY THE START OF THE WIND ADVISORY TO 15Z. EVEN
WITH THE GRADIENT STAYING FAIRLY STRONG SUNDAY EVENING...WINDS
SHOULD BE ABLE TO SUBSIDE ENOUGH AFTER SUNSET SO AN END TIME OF
00Z MONDAY STILL SEEMS REASONABLE.
LATEST RADAR MOSAIC DISPLAYS A FAIRLY LARGE AREA OF PREFRONTAL
PRECIPITATION ACROSS NORTHERN AND WESTERN ILLINOIS SLIDING INTO
NORTHWEST INDIANA. THE HRRR SUGGESTS THIS SHOULD HOLD TOGETHER BUT
STAY JUST NORTH AND WEST OF THE FORECAST AREA. THIS MAKES SENSE DUE
TO THE LOCATION OF THE LEFT EXIT REGION OF THE 50-60 KT 850 MB JET.
THEREFORE...HAVE TRIMMED BACK POPS FOR THE MORNING HOURS..ESPECIALLY
ACROSS THE EASTERN ZONES.
MODELS DISPLAY SOME VARIABILITY IN TIMING THE ARRIVAL OF THE COLD
FRONT AND ITS ASSOCIATED PRECIPITATION. THE NAM AND ECMWF APPEAR TO
BE THE FASTEST WITH QPF ENCOMPASSING A MAJORITY OF THE FORECAST AREA
BY 12Z WHILE THE GFS APPEARS TO BE MORE IN LINE WITH THE HRRR.
REGARDLESS...ALL MODELS DEPICT THE BULK OF THE PRECIPITATION
IMPACTING THE AREA IN THE 18-00Z TIME FRAME SO HAVE HIT POPS THE
HARDEST DURING THE LATE AFTERNOON AND EARLY EVENING HOURS.
IN REGARDS TO SEVERE POTENTIAL...INSTABILITY LOOKS TO BE RESPECTABLE
WITH AROUND 500-750 J/KG TO WORK WITH BY MID TO LATE AFTERNOON.
HOWEVER...THE DYNAMICS APPEAR TO PROVIDE QUITE A BIT MORE SUPPORT
WITH THE FORCING FROM THE COLD FRONT BEING SUPPORTED BY THE UPPER
WAVE. WITH THE GFS DEPICTING 925 MB WINDS APPROACHING 60 KTS...ANY
DECENT STORMS THAT GET GOING SHOULD NOT HAVE TOO HARD OF A TIME
BRINGING SOME OF THAT DOWN TO THE SURFACE. THEREFORE...CONTINUE TO
EXPECT DAMAGING WINDS TO BE THE MAIN THREAT BUT THE POSSIBILITY FOR
SOME LARGE HAIL AND AN ISOLATED TORNADO OR TWO ARE NOT OUT OF THE
QUESTION.
WITH THE INFLUX OF WARM AND MOIST AIR CONTINUING AS SOUTHERLY WINDS
INCREASE...HIGH TEMPERATURES LOOK TO BE SIMILAR TO SATURDAY...IF NOT
A DEGREE OR TWO HIGHER...RANGING FROM THE LOW 70S ACROSS THE NORTH
TO THE MID 70S IN THE SOUTH.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ISSUED AT 325 AM EDT SUN OCT 14 2012
WITH THE UPPER WAVE SLOW TO MOVE OUT OF THE REGION...HAVE HUNG ON TO
SMALL POPS FOR SUNDAY EVENING TO ACCOUNT FOR ANY LINGERING SHOWERS
OR THUNDERSTORMS. HIGH PRESSURE WILL THEN BUILD INTO THE REGION FOR
THE BEGINNING OF THE WORK WEEK ALLOWING DRY CONDITIONS TO RETURN FOR
THE REMAINDER OF THE PERIOD.
NORTHWEST WINDS FOLLOWING FRONTAL PASSAGE WILL ALLOW TEMPERATURES TO
DROP A BIT BUT HIGHS SHOULD BE NEAR NORMAL VALUES (MID 60S) WITH A
FAIR AMOUNT OF SUNSHINE ON BOTH MONDAY AND TUESDAY. LOW TEMPERATURES
LOOK TO REMAIN MILD (UPPER 40S TO LOW 50S) EXCEPT FOR MONDAY NIGHT
WITH THE CENTER OF THE HIGH RIGHT OVER THE AREA WHEN TEMPERATURES
COULD FALL TO AROUND 40 DEGREES.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 325 AM EDT SUN OCT 14 2012
UNSETTLED WEATHER WILL BE THE RULE...ESPECIALLY EARLY ON. A STRONG
UPPER LOW WILL MOVE INTO THE NORTHERN PLAINS WEDNESDAY AND THEN
TRACK INTO OUR REGION TOWARDS THE WEEKEND WITH SOME MODELS MOVING IT
ON TO THE EAST OVER THE WEEKEND. MODELS INDICATE A STRONG COLD
FRONT WILL MOVE ACROSS OUR REGION LATE WEDNESDAY NIGHT OR EARLY
THURSDAY. ON WEDNESDAY WE CAN EXPECT INCREASING CLOUDS WITH A CHANCE
OF PRECIP LATE ACROSS OUR NORTHWEST HALF. RAISED ALL BLEND
TEMPERATURES SLIGHTLY AS WARM ADVECTION WILL BE OCCURRING AHEAD OF
FRONT AND MEX NUMBERS WERE RUNNING ABOUT 5 DEGREES WARMER.
WILL CONTINUE LIKELY POPS MOST AREAS WEDNESDAY NIGHT AS FRONT MOVES
THROUGH AND THEN THERE IS SOME QUESTION ON THURSDAY AS A DRY SLOT
PUSHES INTO OUR WEST. FOR NOW WILL ACCEPT ALL BLEND POPS WHICH HAS
SLIGHT CHANCE POPS ACROSS OUR WEST AND CHANCE POPS FATHER EAST.
WILL CONTINUE LOW POPS MOST AREAS REST OF FORECAST AS UPPER LOW
ROTATES INTO OUR REGION. BY DAY 7 GFS HAS IT WELL TO OUR EAST WHILE
NEW EURO STILL HAS IT ACROSS OUR REGION. EXCEPT FOR RAISING MINS A
LITTLE THURSDAY NIGHT AND FRIDAY NIGHT WITH CLOUDS...DID NOT MAKE
ANY SIGNIFICANT CHANGE TO ALL BLEND TEMPERATURES FOR THE REST OF THE
EXTENDED.
&&
.AVIATION /DISCUSSION FOR THE 140900Z KIND TAF UPDATE/...
ISSUED AT 4330 AM EDT SUN OCT 14 2012
MINOR TWEAKS MADE TO KIND TAF PER OBSERVATIONS. NO OTHER CHANGES
NEEDED AT THIS TIME. PREVIOUS AVIATION DISCUSSION FOLLOWS...
A COLD FRONT WILL DROP SOUTHEAST ACROSS CENTRAL INDIANA AFTER 22Z
SUNDAY. RAPID REFRESH REFLECTIVITY SUGGESTS WIDESPREAD SHOWERS AND
THUNDERSTORMS WILL MOVE IN AHEAD OF THE FRONT AFTER 11Z.
MEANWHILE...RADAR TRENDS SUGGEST ANY AREA OF ADDITIONAL SHOWERS AND
PERHAPS THUNDERSTORMS WILL OVERSPREAD LAF BY ISSUANCE TIME.
SO...WILL GO WITH AT LEAST TEMPO SHOWERS THERE. COULD SEE SOME MVFR
CONDITIONS AT LAF OVERNIGHT AND THE OTHER SITES AFTER 11Z.
WINDS WILL ALSO BE AN ISSUE AS THE SURFACE PRESSURE GRADIENT
TIGHTENS. SOUTH WINDS WILL GUSTS TO NEAR 20 KNOTS OVERNIGHT AND
SUSTAINED TO 20 KNOTS WITH GUSTS NEAR 35 KNOTS AFTER 11Z. WINDS WILL
THEN BECOME SOUTHWEST AND THEN WEST BEHIND THE FRONT AFTER 22Z AND
DECREASE A BIT TO AROUND 15 KNOTS WITH 20 KNOT GUSTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING FOR
INZ021-028>031-035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...HOMANN
NEAR TERM...HOMANN
SHORT TERM...HOMANN
LONG TERM....JEH
AVIATION...MK/JEH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
326 AM EDT SUN OCT 14 2012
.UPDATE...
THE SYNOPSIS...NEAR TERM...SHORT TERM AND LONG TERM SECTIONS HAVE BEEN
UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 325 AM EDT SUN OCT 14 2012
LOW PRESSURE CENTERED OUT IN THE PLAINS WILL CONTINUE TO MOVE
TOWARDS THE GREAT LAKES REGION FOR THE END OF THE WEEKEND. A STRONG
COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL CROSS CENTRAL INDIANA
TODAY BRINGING THE CHANCE FOR SHOWERS AND THUNDERSTORMS TO THE
AREA...WITH THE POSSIBILITY OF STRONG TO SEVERE STORMS.
ADDITIONALLY...STRONG SOUTHERLY WINDS WITH GUSTS OVER 40 MPH ARE
POSSIBLE THIS AFTERNOON AS THE LOW CONTINUES TO STRENGTHEN.
HIGH PRESSURE WILL RETURN TO THE AREA ON MONDAY WITH DRY CONDITIONS
EXPECTED TO CONTINUE FOR ROUGHLY THE FIRST HALF OF THE WORK WEEK.
ANOTHER SYSTEM IS EXPECTED TO IMPACT THE REGION MIDWEEK BRINGING
ADDITIONAL CHANCES FOR PRECIPITATION HEADING INTO NEXT WEEKEND.
&&
.NEAR TERM /TODAY/...
ISSUED AT 325 AM EDT SUN OCT 14 2012
FORECAST CONCERNS FOR THE NEAR TERM CONTINUE TO BE THE STRONG WINDS
EXPECTED THIS AFTERNOON AS WELL AS THE POTENTIAL FOR SEVERE STORMS
AS A COLD FRONT PASSES THROUGH THE AREA.
WINDS ARE NOT AS STRONG THIS MORNING AS PREVIOUSLY FORECAST WITH THE
PRESSURE GRADIENT TAKING A BIT LONGER TO TIGHTEN UP AS THE LOW IS
SLOWER TO DEEPEN THAN EXPECTED. CURRENT THINKING IS THAT THE HIGHEST
SUSTAINED SPEEDS (20-25 MPH) AND ASSOCIATED GUSTS (40-45 MPH) WILL
NOT MIX DOWN UNTIL CLOSER TO 15Z...RATHER THAN AS EARLY AS 12Z.
THEREFORE...WILL DELAY THE START OF THE WIND ADVISORY TO 15Z. EVEN
WITH THE GRADIENT STAYING FAIRLY STRONG SUNDAY EVENING...WINDS
SHOULD BE ABLE TO SUBSIDE ENOUGH AFTER SUNSET SO AN END TIME OF
00Z MONDAY STILL SEEMS REASONABLE.
LATEST RADAR MOSAIC DISPLAYS A FAIRLY LARGE AREA OF PREFRONTAL
PRECIPITATION ACROSS NORTHERN AND WESTERN ILLINOIS SLIDING INTO
NORTHWEST INDIANA. THE HRRR SUGGESTS THIS SHOULD HOLD TOGETHER BUT
STAY JUST NORTH AND WEST OF THE FORECAST AREA. THIS MAKES SENSE DUE
TO THE LOCATION OF THE LEFT EXIT REGION OF THE 50-60 KT 850 MB JET.
THEREFORE...HAVE TRIMMED BACK POPS FOR THE MORNING HOURS..ESPECIALLY
ACROSS THE EASTERN ZONES.
MODELS DISPLAY SOME VARIABILITY IN TIMING THE ARRIVAL OF THE COLD
FRONT AND ITS ASSOCIATED PRECIPITATION. THE NAM AND ECMWF APPEAR TO
BE THE FASTEST WITH QPF ENCOMPASSING A MAJORITY OF THE FORECAST AREA
BY 12Z WHILE THE GFS APPEARS TO BE MORE IN LINE WITH THE HRRR.
REGARDLESS...ALL MODELS DEPICT THE BULK OF THE PRECIPITATION
IMPACTING THE AREA IN THE 18-00Z TIME FRAME SO HAVE HIT POPS THE
HARDEST DURING THE LATE AFTERNOON AND EARLY EVENING HOURS.
IN REGARDS TO SEVERE POTENTIAL...INSTABILITY LOOKS TO BE RESPECTABLE
WITH AROUND 500-750 J/KG TO WORK WITH BY MID TO LATE AFTERNOON.
HOWEVER...THE DYNAMICS APPEAR TO PROVIDE QUITE A BIT MORE SUPPORT
WITH THE FORCING FROM THE COLD FRONT BEING SUPPORTED BY THE UPPER
WAVE. WITH THE GFS DEPICTING 925 MB WINDS APPROACHING 60 KTS...ANY
DECENT STORMS THAT GET GOING SHOULD NOT HAVE TOO HARD OF A TIME
BRINGING SOME OF THAT DOWN TO THE SURFACE. THEREFORE...CONTINUE TO
EXPECT DAMAGING WINDS TO BE THE MAIN THREAT BUT THE POSSIBILITY FOR
SOME LARGE HAIL AND AN ISOLATED TORNADO OR TWO ARE NOT OUT OF THE
QUESTION.
WITH THE INFLUX OF WARM AND MOIST AIR CONTINUING AS SOUTHERLY WINDS
INCREASE...HIGH TEMPERATURES LOOK TO BE SIMILAR TO SATURDAY...IF NOT
A DEGREE OR TWO HIGHER...RANGING FROM THE LOW 70S ACROSS THE NORTH
TO THE MID 70S IN THE SOUTH.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ISSUED AT 325 AM EDT SUN OCT 14 2012
WITH THE UPPER WAVE SLOW TO MOVE OUT OF THE REGION...HAVE HUNG ON TO
SMALL POPS FOR SUNDAY EVENING TO ACCOUNT FOR ANY LINGERING SHOWERS
OR THUNDERSTORMS. HIGH PRESSURE WILL THEN BUILD INTO THE REGION FOR
THE BEGINNING OF THE WORK WEEK ALLOWING DRY CONDITIONS TO RETURN FOR
THE REMAINDER OF THE PERIOD.
NORTHWEST WINDS FOLLOWING FRONTAL PASSAGE WILL ALLOW TEMPERATURES TO
DROP A BIT BUT HIGHS SHOULD BE NEAR NORMAL VALUES (MID 60S) WITH A
FAIR AMOUNT OF SUNSHINE ON BOTH MONDAY AND TUESDAY. LOW TEMPERATURES
LOOK TO REMAIN MILD (UPPER 40S TO LOW 50S) EXCEPT FOR MONDAY NIGHT
WITH THE CENTER OF THE HIGH RIGHT OVER THE AREA WHEN TEMPERATURES
COULD FALL TO AROUND 40 DEGREES.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 325 AM EDT SUN OCT 14 2012
UNSETTLED WEATHER WILL BE THE RULE...ESPECIALLY EARLY ON. A STRONG
UPPER LOW WILL MOVE INTO THE NORTHERN PLAINS WEDNESDAY AND THEN
TRACK INTO OUR REGION TOWARDS THE WEEKEND WITH SOME MODELS MOVING IT
ON TO THE EAST OVER THE WEEKEND. MODELS INDICATE A STRONG COLD
FRONT WILL MOVE ACROSS OUR REGION LATE WEDNESDAY NIGHT OR EARLY
THURSDAY. ON WEDNESDAY WE CAN EXPECT INCREASING CLOUDS WITH A CHANCE
OF PRECIP LATE ACROSS OUR NORTHWEST HALF. RAISED ALL BLEND
TEMPERATURES SLIGHTLY AS WARM ADVECTION WILL BE OCCURRING AHEAD OF
FRONT AND MEX NUMBERS WERE RUNNING ABOUT 5 DEGREES WARMER.
WILL CONTINUE LIKELY POPS MOST AREAS WEDNESDAY NIGHT AS FRONT MOVES
THROUGH AND THEN THERE IS SOME QUESTION ON THURSDAY AS A DRY SLOT
PUSHES INTO OUR WEST. FOR NOW WILL ACCEPT ALL BLEND POPS WHICH HAS
SLIGHT CHANCE POPS ACROSS OUR WEST AND CHANCE POPS FATHER EAST.
WILL CONTINUE LOW POPS MOST AREAS REST OF FORECAST AS UPPER LOW
ROTATES INTO OUR REGION. BY DAY 7 GFS HAS IT WELL TO OUR EAST WHILE
NEW EURO STILL HAS IT ACROSS OUR REGION. EXCEPT FOR RAISING MINS A
LITTLE THURSDAY NIGHT AND FRIDAY NIGHT WITH CLOUDS...DID NOT MAKE
ANY SIGNIFICANT CHANGE TO ALL BLEND TEMPERATURES FOR THE REST OF THE
EXTENDED.
&&
.AVIATION /DISCUSSION FOR THE 140600Z TAF ISSUANCE/...
ISSUED AT 1230 AM EDT SUN OCT 14 2012
A COLD FRONT WILL DROP SOUTHEAST ACROSS CENTRAL INDIANA AFTER 22Z
SUNDAY. RAPID REFRESH REFLECTIVITY SUGGESTS WIDESPREAD SHOWERS AND
THUNDERSTORMS WILL MOVE IN AHEAD OF THE FRONT AFTER 11Z.
MEANWHILE...RADAR TRENDS SUGGEST ANY AREA OF ADDITIONAL SHOWERS AND
PERHAPS THUNDERSTORMS WILL OVERSPREAD LAF BY ISSUANCE TIME.
SO...WILL GO WITH AT LEAST TEMPO SHOWERS THERE. COULD SEE SOME MVFR
CONDITIONS AT LAF OVERNIGHT AND THE OTHER SITES AFTER 11Z.
WINDS WILL ALSO BE AN ISSUE AS THE SURFACE PRESSURE GRADIENT
TIGHTENS. SOUTH WINDS WILL GUSTS TO NEAR 20 KNOTS OVERNIGHT AND
SUSTAINED TO 20 KNOTS WITH GUSTS NEAR 35 KNOTS AFTER 11Z. WINDS WILL
THEN BECOME SOUTHWEST AND THEN WEST BEHIND THE FRONT AFTER 22Z AND
DECREASE A BIT TO AROUND 15 KNOTS WITH 20 KNOT GUSTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING FOR
INZ021-028>031-035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...HOMANN
NEAR TERM...HOMANN
SHORT TERM...HOMANN
LONG TERM....JEH
AVIATION...MK
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1058 PM MDT SAT OCT 13 2012
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 236 PM MDT SAT OCT 13 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW STRONG UPPER LOW CENTERED
ALONG KS/CO BORDER WITH AXIS OF MOISTURE ON BACK SIDE OF UPPER LOW
BEGINNING TO MOVE FROM CENTRAL INTO EASTERN COLORADO. RADAR
CURRENTLY INDICATED SHOWERS/ISOLATED THUNDERSTORMS DEVELOPING OVER
THE WESTERN PART OF OUR CWA ALONG KS/CO STATE LINE. THIS IS AHEAD OF
H7 TROUGH AND ALONG NORTHWESTERN AXIS OF STEEP LAPSE RATES.
LATEST HRRR AND RUC BOTH SHOW SHOWERS AND THUNDERSTORMS CONTINUING
TO DEVELOP EASTWARD ACROSS THE REST OF THE CWA THROUGH THE EARLY
EVENING. THIS ACTIVITY SHOULD DIMINISH AFTER SUNSET AS WE LOOSE THE
STEEP LOW LEVEL LAPSE RATES. WITH SCATTERED COVERAGE...AND LIGHT
NATURE OF MOST OF THIS ACTIVITY...PRECIPITATION SHOULD BE LIGHT.
DESPITE MINIMAL CAPE VALUES IN THE 100-500 J/KG RANGE AND WEAK
0-6KM SHEAR...IT WILL NOT TAKE MUCH TO PRODUCE SEVERE HAIL WITH
-20C HEIGHTS AROUND 15-18KFT ACROSS THE CWA. WITH LOW LCL VALUES
AROUND 1500 KFT AND FAVORABLE AREA BENEATH UPPER LOW WHERE
DIFFERENTIAL HEATING AXIS/SURFACE TROUGH OVERLAP...I CANT RULE OUT
FUNNEL/LANDSPOUT FORMATION WITH THIS ACTIVITY THIS AFTERNOON/EARLY
EVENING. CONSIDERING ABSENCE OF DISTINCT SURFACE BOUNDARY...AND
LOCATION OF BEST SURFACE VORTICITY FURTHER NORTH...THIS THREAT
SEEMS TO BE MINIMAL AT BEST.
THE UPPER LOW WILL SHIFT EAST OF THE CWA BY 06Z TONIGHT...WITH
SHORTWAVE RIDGING AND LARGE SCALE SUBSIDENCE OVERSPREADING THE AREA
BY SUNDAY. WITH SIMILAR H85 TEMPS AND NW WIND PERSISTING...TEMPERATURES
ON SUNDAY SHOULD AT LEAST BE SIMILAR TO THIS AFTERNOON WITH HIGHS
IN THE 70S FOR MOST OF THE AREA.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 236 PM MDT SAT OCT 13 2012
SUNDAY NIGHT THROUGH MONDAY NIGHT DRY NORTHWEST UPPER LEVEL FLOW
WILL CONTINUE OVER THE AREA. A SHORT WAVE TROUGH MOVES THROUGH THE
FLOW LATE MONDAY NIGHT ACCOMPANYING A SURFACE TROUGH/WEAK COLD
FRONT. POINT SOUNDINGS INDICATE THE UPPER LEVELS MOISTEN AS THE
SHORT WAVE MOVES THROUGH...SO AM ONLY EXPECTING A FEW CLOUDS TO
DEVELOP DURING THE OVERNIGHT HOURS.
TUESDAY THROUGH SATURDAY WILL REMAIN DRY. A COLD FRONT AND UPPER
LEVEL SHORT WAVE TROUGH WILL MOVE THROUGH WEDNESDAY. BEHIND THE
COLD FRONT WINDS WILL BECOME GUSTY DURING THE AFTERNOON. MOISTURE
WILL REMAIN NORTH OF THE AREA...SO AM NOT ANTICIPATING ANY PRECIP
WITH THE FRONT. THERE MAY BE SOME LIFT FROM THE LEFT EXIT OF THE 500
MB JET...BUT MODELS DISAGREE WITH THE JET PLACEMENT BEHIND THE
FRONT. WITH THE MOISTURE GENERALLY NORTH OF THE AREA AND THE
POSITION OF THE JET IN QUESTION...WILL LEAVE THE FRONTAL PASSAGE DRY.
OTHERWISE TEMPERATURES WILL BE 10 DEGREES ABOVE NORMAL AHEAD THE
COLD FRONT...WITH NEAR NORMAL TEMPERATURES BEHIND THE FRONT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1047 PM MDT SAT OCT 13 2012
VFR CONDITIONS EXPECTED FOR THE NEXT 24 HOURS AT KGLD AND KMCK AS
CLEARING OCCURS BEHND THE EXITING LOW. REDEVELOPMENT OF A BREEZY
NORTH WIND AND CUMULUS CAN BE EXPECTED FOR A FEW HOURS TUESDAY
AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JTL
AVIATION...FS
AREA FORECAST DISCUSSION...UPDATED
NWS PADUCAH KY
1138 PM CDT SAT OCT 13 2012
.UPDATE...
ISSUED AT 1133 PM CDT SAT OCT 13 2012
UPDATED AVIATION SECTION FOR THE 06Z TAF ISSUANCE.
&&
UPDATED FORECAST TO RAISE POPS TO CATEGORICAL IN PARTS OF SE
MISSOURI AND SW ILLINOIS LATE TONIGHT. RUC MODEL INDICATES THAT
WIDESPREAD RAIN AND STORMS IN THE WARM CONVEYOR BELT OVER
NORTHERN/WESTERN MISSOURI WILL OVERSPREAD SE MISSOURI AND SW
ILLINOIS AFTER 06Z. THE AXIS OF THE LOW LEVEL JET WILL BE ORIENTED
ALONG OR JUST WEST OF THE MISSISSIPPI RIVER BY 12Z...WITH 50 TO 60
KNOTS IN THE 850/900 MB LAYER. THOUGH INSTABILITY WILL BE MARGINAL
AND ELEVATED...A FEW DAMAGING WIND GUSTS ARE POSSIBLE GIVEN THE WIND
FIELDS ALOFT AND STRONG FORCING FOR CONVECTION.
ADDED MENTION OF GRADIENT WIND GUSTS FROM 30 TO 40 MPH TO THE HWO.
BUFKIT ANALYSIS FROM BOTH GFS/NAM INDICATES SUFFICIENT MIXING ON
SUNDAY TO GET SOME SURFACE GUSTS TO NEAR 40 MPH. DEGREE OF CLEARING
IN THE WAKE OF THE MORNING CONVECTION WILL PLAY A LARGE ROLE IN WIND
GUST POTENTIAL...AS WELL AS POTENTIAL FOR AFTERNOON STORMS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 310 PM CDT SAT OCT 13 2012
DID NOT MAKE ANY DRASTIC CHANGES TO THE GOING FORECAST. ECMWF AND
GEM ARE BOTH A BIT FASTER WITH THE ONSET OF PRECIP THAN THE GFS
AND NAM...BRINGING SHOWERS AND THUNDERSTORMS INTO OUR FAR WESTERN
COUNTIES BY 06Z SUNDAY. OVERALL...THE TIMING DIFFERENCES ARE
MINOR...AND WENT WITH LIKELY POPS FOR THE WESTERN HALF OF THE PAH
FORECAST AREA BY 12Z SUNDAY. THE BEST CHANCES FOR THE WESTERN HALF
OF THE FA WILL BE THROUGH THE MORNING INTO THE EARLY
AFTERNOON...AND THE EASTERN HALF FROM MID MORNING THROUGH MID
AFTERNOON. ALL OF OUR COUNTIES HAVE AT LEAST A FEW HOURS OF LIKELY
POPS.
ECMWF AND GFS SHOW LI`S OF -1 TO -3...AND CAPE VALUES OF
700 TO 1100 J/KG...MAINLY FROM 12Z TO 18Z SUNDAY. NAM CONTINUES
SOME IMPRESSIVE LI AND CAPE VALUES /-3 TO -5 AND 1000 TO 1300
J/KG/ INTO THE AFTERNOON HOURS...WHEN ECMWF AND GFS HAVE ALREADY
PUSHED BEST LIFT/INSTABILITY EAST OF OUR COUNTIES. BASED ON THE
FRONT/UPPER TROF STILL IN WESTERN PORTIONS OF THE FA BY MID
AFTERNOON AND SPC DAY 2 SLIGHT RISK FOR ALL BUT FAR WESTERN
PORTIONS OF OUR FA...NAM LOOKS LIKE A BETTER BET...SO SHOULD SEE
SOME DECENT ACTIVITY THROUGH THE DAY...WITH SOME POTENTIAL FOR
SEVERE STORMS.
THE OTHER ISSUE FOR SUNDAY IS WINDS. MODELS SHOW A VERY TIGHT
PRESSURE GRADIENT TONIGHT AND ESPECIALLY SUNDAY ALONG AND AHEAD OF
THE FRONT. SOUTH TO SOUTHWEST WINDS WILL PICK BACK UP TO 10 TO 15
KTS LATE TONIGHT...THEN INCREASE TO 15 TO 25 KTS WITH GUSTS OF 30
TO 35 KTS FROM 12Z TO 22Z. THIS KEEPS US BELOW WIND ADVISORY
CRITERIA...BUT WILL CONTINUE WITH AN SPS TO HEIGHTEN AWARENESS.
BEYOND SUNDAY...HIGH PRESSURE WILL BUILD INTO THE CENTRAL U.S. FOR
SUNDAY NIGHT THROUGH MONDAY NIGHT. AFTER ABOVE NORMAL TEMPERATURES
ON SUNDAY...NORTHWEST WINDS BEHIND THE FRONT WILL BRING
TEMPERATURES BACK TO NEAR TO EVEN SLIGHTLY BELOW NORMAL TEMPS.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 310 PM CDT SAT OCT 13 2012
THE BIG EVENT OF THE LONG TERM IS THE MID WEEK SYSTEM SO WE WILL
FOCUS ON THAT HERE. POSITIVE MODEL INDICATIONS ARE THAT BOTH THE
EURO AND THE GFS ARE SYNCHRONIZING THE INTRODUCTORY PCPN TIMING AS
THE FRONT APPROACHES THE DOORSTEP OF THE FA BY 00Z THU. IT WILL
ENCOUNTER MINOR INSTABILITY...MAINLY ELEVATED...AS BOTH MODELS AGREE
THE BEST CHANCE OF PCPN COMES WITH/POST FROPA OVERNIGHT WED NIGHT.
WE LIKE THE ALLBLENDS LIKELY CAT POPS AS A STARTING POINT AND COULD
BE GOING UP FROM THERE...BUT WITH LATE DAY 5 WE`LL SEE HOW COLLAB
PLAYS OUT ON THAT.
MODEL DIFFERENCES START WITH THE DEPARTURE OF THE SYSTEM ON
THURSDAY. THE EURO IS MORE AMPLIFIED AND CUTS OFF/DEEPENS THE
LOW...OCCLUDING THE FRONT/LINGERING THE POPS. THE GFS LIKEWISE HAS A
ROBUST/DEEPENING OF THE LOW BUT IS MORE PROGRESSIVE WITH IT ACTUALLY
PASSING AND SWEEPING EASTWARD TO THE EAST COAST. THE ALLBLENDS TENDS
BETWEEN THE TWO WITH LEAN TOWARD THE GFS AND WE THINK THAT IS
REASONABLE UNLESS/UNTIL MORE SUPPORT IS YIELDED TOWARD THE EURO.
TEMPS...70S/50S LOOK REASONABLE AHEAD OF THE FRONT...WITH 60S/40S
AFTER ITS PASSAGE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1133 PM CDT SAT OCT 13 2012
VFR CONDITIONS EXPECTED AT KCGI/KPAH THROUGH 09-10Z...MVFR CIGS/VSBYS
AND TSRA THROUGH 15-16Z...THEN VFR AGAIN. AT KEVV/KOWB VFR CONDITIONS
EXPECTED THROUGH 13-14Z...MVFR CIGS/VSBYS AND TSRA THROUGH 19-20Z...THEN
VFR. SOUTHERLY WINDS AROUND 10 KTS WILL PICK UP OUT OF THE SOUTH
SOUTHWEST AFT 10Z AT 15-20 KTS WITH GUSTS TO 25-30 KTS...THEN VEER
AROUND TO THE WEST AT 10-15 KTS AFT 00Z.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AVIATION...JP
PUBLIC/GRIDS...MY
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
217 AM EDT SUN OCT 14 2012
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 423 PM EDT SAT OCT 13 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A ZONALLY ORIENTED FLOW
ACROSS SRN CANADA AND THE FAR NRN CONUS. TO THE S...A SHORTWAVE TROF
IS EMERGING FROM CO/NM INTO THE WRN PLAINS. DEEP/MOIST SW FLOW
DOWNSTREAM OF THE TROF HAS GENERATED SEVERAL AREAS OF SHRA AND SOME
TSRA FROM THE SRN PLAINS TO THE GREAT LAKES. WITH THE MORE ZONALLY
ORIENTED FLOW ACROSS THE FAR NRN CONUS...THE AREAS OF SHRA HAVE BEEN
TENDING TO SHIFT MORE EASTWARD THE FARTHER N THEY SPREAD. AS A
RESULT...THERE HAS BEEN LITTLE PCPN OVER THE NW HALF OF THE FCST
AREA TODAY (MUCH OF THE PCPN HAS BEEN DRIZZLE) WHILE THE SE HALF HAS
BEEN GETTING BRUSHED BY SHRA.
PCPN TRENDS/COVERAGE WILL BE THE MAIN FCST ISSUES IN THE SHORT TERM.
FLOW ACROSS SRN CANADA/FAR NRN CONUS IS EXPECTED TO BUCKLE AS HEIGHT
RISES OVER WRN NAMERICA FORCE DOWNSTREAM HEIGHT FALLS INTO
MISSISSIPPI VALLEY REGION. THIS WILL HELP TO PICK UP/LIFT THE WRN
PLAINS SHORTWAVE TO THE NE. EXACTLY HOW FAR N IT LIFTS WILL BE
IMPORTANT TO THE PCPN FCST TONIGHT/SUN. EVEN AT THIS SHORT TIME
RANGE INTO MODEL RUNS...THERE ARE STILL IMPORTANT DIFFERENCES IN THE
MODELS. THE NAM REMAINS MOST SUPPRESSED WITH THE LOW TRACK THOUGH IT
HAS TRENDED SLIGHTLY N...AND IT IS SUPPORTED BY OUR LOCAL REG WRF
RUN AND THE NCEP HIGH RES WRF-ARW AND WRF-NMN. THEY ALL KEEP THE
MAIN PCPN SHIELD ALMOST ENTIRELY SE OF FCST AREA SUN. THE 12Z GFS
HAS TRENDED S AND ONLY BRINGS PCPN SHIELD INTO THE SE FCST AREA. THE
UKMET/REGIONAL GEM PUSH PCPN SHIELD A LITTLE FARTHER N AND W. THE 12Z
ECMWF HAS ALSO TRENDED SLIGHTLY S. GIVEN OVERALL TRENDS AND A
MAJORITY SHOWING A LESS AGGRESSIVE MOISTURE PUSH INTO UPPER MI
SUN...FCST WILL FOLLOW SUIT AND SHOW HIGHER POPS SHIFTED MORE TO THE
S AND E.
CURRENT PUSH OF SHRA ENE THRU WI INTO SRN UPPER MI IS ASSOCIATED
WITH A SURGE OF 850-700MB MOISTURE TRANSPORT AND ISENTROPIC ASCENT
ON THE 305K SFC. WITH THAT MOISTURE TRANSPORT/ASCENT QUICKLY
SHIFTING E THIS EVENING...AND THEN RATHER MEAGER FORCING LEFT BEHIND
FOR THE NIGHT...IT APPEARS THERE WON`T BE MUCH IN THE WAY OF
RAINFALL FOR THE BULK OF TONIGHT AS WE AWAIT THE MAIN PIECE OF
ENERGY TO TRACK INTO THE GREAT LAKES SUN. WITH WINDS BECOMING LIGHT
UPSLOPE OFF LAKE SUPERIOR DURING THE NIGHT...-DZ THAT HAS BEEN
OCCURRING TODAY WILL LIKELY CONTINUE TONIGHT...ESPECIALLY ACROSS THE
NCNTRL.
SHORTWAVE LIFTS INTO THE GREAT LAKES SUN AFTN WITH ASSOCIATED SFC
LOW TRACKING TOWARD NRN LWR MI. AS A RESULT...RAIN WILL SPREAD BACK
TO THE N...BUT AS DISCUSSED ABOVE...LOWERED POPS FROM PREVIOUS FCST.
KEPT CATEGORICAL POPS ONLY ALONG LAKE MICHIGAN INTO THE FAR ERN FCST
AREA WITH POPS DROPPING OFF SHARPLY TO CHC JUST TO THE NW. MAY SEE A
LITTLE LAKE ENHANCED SHRA ACTIVITY IN THE NNE/NE WIND FAVORED
LOCATIONS...SO SHRA CHANCES IN THOSE AREAS WILL BE A LITTLE HIGHER.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 423 PM EDT SAT OCT 13 2012
A FAIRLY STRONG UPPER SHORTWAVE TROUGH WILL BE OVER THE CENTRAL CWA
AT 00Z MON...DEEPENING AS IT MOVES TO THE FAR ERN CWA BY 06Z MON DUE
TO A WEAK SHORTWAVE PHASING WITH THE SYSTEM. AT THE SFC...A ROUGHLY
995MB LOW WILL BE OVER OVER NRN LOWER MI AT 00Z MON...MOVING TO
GEORGIAN BAY BY 06Z MON. THE 850MB LOW WILL BE JUST E OF DRUMMOND
ISLAND AT 00Z MON...WITH A NICE DEFORMATION PRECIP BAND JUST ON THE
LEFT SIDE OF THE 850MB LOW TRACK AS IT MOVES NE. THERE SHOULD BE A
PRETTY SHARP CUT OFF BETWEEN THE DEFORMATION BAND AND LITTLE TO NO
SYNOPTIC RAIN...AND AFTER 00Z SUN...THE CWA SHOULD BE ON THE DRIER
SIDE OF THAT CUT OFF. HOWEVER...WITH THE SHORTWAVE DEEPENING
OVERHEAD THEN MOVING E...COLDER 850MB TEMPS WILL FILTER IN FROM THE
NNW. WITH THE NNW LOW LEVEL WINDS AND 850MB TEMPS OF -3C TO
-4C...SOME LIGHT LAKE EFFECT RAIN /MIXING WITH SNOW OVER THE HIGHER
TERRAIN/ WILL LINGER INTO MONDAY MORNING OVER NCENTRAL AND ERN UPPER
MI.
A SFC RIDGE WILL MOVE OVER MON AFTERNOON AND EVENING...BRINGING A
BRIEF DRY PERIOD BEFORE A SHORTWAVE TROUGH AND ASSOCIATED WARM FRONT
MOVE INTO THE CWA. PRECIP CHANCES MOVE BACK IN WITH THIS SYSTEM
AFTER MIDNIGHT MON NIGHT...WITH AT LEAST SLIGHT CHANCE POPS OVER
PARTS OF THE CWA UNTIL MORE PRECIP ARRIVES WITH A LOW PRESSURE
SYSTEM MOVING IN FROM THE W ON WED. HIGHS ON MON LOOK TO BE IN THE
UPPER 40S TO MID 50...WITH WARMER TEMPS ON TUE IN THE 50S. WED LOOKS
TO CONTINUE THE WARM TREND WITH HIGHS AGAIN IN THE 50S. OVERALL GOOD
CONFIDENCE INTO WED.
CONFIDENCE DECREASES AS THE NEXT SYSTEM MOVES IN WED INTO THE END OF
NEXT WEEK SINCE MODELS GENERALLY SHOW THE SAME IDEA OF THE LOW
CLOSING OFF ON THU AND LINGERING SOMEWHERE OVER/NEAR THE REGION
THROUGH THE END OF THE WEEK. HOWEVER...MODELS SHOW SIGNIFICANTLY
VARYING SOLUTIONS WITH WHERE TO HAVE THE LOW...WHICH CAUSES WIDELY
DIFFERENT PRECIP/WIND SCENARIOS. EVEN WITH THE DIFFERENCES...WILL
HAVE CHANCES OF PRECIP FOR THE REST OF THE PERIOD LATE WED THROUGH
SAT...DERIVED FROM CONSENSUS OF MODELS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 213 AM EDT SUN OCT 14 2012
LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE NORTHEAST TOWARD THE
WRN GREAT LAKES DURING THE FCST PERIOD. AT KIWD...WILL CONTINUE TO
SEE VLIFR CONDITIONS/-DZ LATER TONIGHT AS NNE WINDS STRENGTHEN
ACROSS LAKE SUPERIOR FOR SOME UPSLOPE. DRIER AIR GETS ADVECTED IN BY
AFTERNOON WITH MVFR CONDITIONS EXPECTED THROUGH THE REST OF THE
PERIOD AT KIWD. AT KCMX...MVFR CONDITIONS SHOULD GENERALLY PREVAIL
OVERNIGHT INTO SUNDAY IN MOSTLY DOWNSLOPE NE FLOW. AT KSAW...LOW
MVFR CONDITIONS WILL FALL BACK TO LIFR CONDITIONS LATER TONIGHT/SUN
AS UPSLOPE NNE WINDS STRENGTHEN. DRIER AIR LATE IN THE AFTERNOON
SHOULD BRING MVFR CONDITIONS TO KSAW. &&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 423 PM EDT SAT OCT 13 2012
WINDS ARE IN THE PROCESS OF DIMINISHING ACROSS LAKE SUPERIOR AS LOW
PRES TROF/WEAKER PRES GRADIENT SHIFT OVER THE AREA. LATER TONIGHT
AND INTO SUN...N TO NE WINDS WILL INCREASE AS LOW PRES MOVES NE
TOWARD NRN LWR MICHIGAN. DURING SUN AFTN...WINDS SHOULD BE IN THE
20-30KT RANGE OVER THE CNTRL AND ERN PORTIONS OF LAKE SUPERIOR.
WINDS WILL BE LIGHTER OVER THE FAR W. SOME NORTHERLY GALE GUSTS OVER
EASTERN LAKE SUPERIOR ARE POSSIBLE INTO SUNDAY NIGHT AS THE LOW
MOVES EAST OF THE AREA AND HIGH PRESSURE PUSHES IN FROM THE WEST.
WINDS SETTLE DOWN MONDAY AND MONDAY NIGHT WITH ARRIVAL OF HIGH
PRESSURE. ANOTHER LOW PRESSURE WILL MOVE INTO THE UPPER GREAT LAKES
ON WEDNESDAY. SOUTH WINDS COULD PUSH UP TO 25 KTS AHEAD OF THE LOW
ON TUESDAY...MAINLY FOR EASTERN SECTIONS. OTHERWISE...WINDS IN THE
VICINITY OF THE LOW SHOULD REMAIN LESS THAN 20 KTS WEDNESDAY INTO
THURSDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...07
MARINE...ROLFSON/TITUS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1147 PM CDT SAT OCT 13 2012
.AVIATION...
06Z TAFS FOR KOFK...KLNK AND KOMA.
GENERALLY VFR CONDITIONS ARE EXPECTED THROUGH SUNDAY EVENING
OUTSIDE OF ANY THUNDERSTORM ACTIVITY. SCATTERED THUNDERSTORMS WILL
AFFECT KLNK AND KOMA AREAS THROUGH ABOUT 09Z SATURDAY MORNING AS
A LOW PRESSURE SYSTEM AND COLD FRONT MOVE THROUGH THE AREA.
ASSOCIATED MVFR CIGS/VSBYS CAN BE EXPECTED. OTHERWISE NORTHWEST
WINDS WILL FOLLOW THE FRONT AND INCREASE TO THE 15 TO 30 KT RANGE
BY 15Z SUNDAY UNDER CLEAR SKIES. THOSE WINDS SHOULD DIMINISH TO
UNDER 10KT BY 00Z.
DERGAN
&&
.PREV DISCUSSION... /ISSUED 318 PM CDT SAT OCT 13 2012/
SHORT TERM...TONIGHT THROUGH TUESDAY
MUCH WARMER AND MOISTER AIR HAS REACHED THE REGION AHEAD OF AN
ADVANCING UPPER-LEVEL LOW. SUBJECTIVE 12Z UPPER AIR ANALYSIS
INDICATES OPENING UPPER LOW CENTERED IN SOUTHERN CO...WITH 500MB
HEIGHT FALLS UP TO 90M IN EASTERN CO INDICATING THE WAVE IS EJECTING
INTO THE CENTRAL PLAINS. CORE OF UPPER-LEVEL JET EXTENDED FROM GULF
OF CA THROUGH WESTERN KS/NEB AND INTO CENTRAL MN...WITH STRONGER
NORTHERN STREAM JET STREAK NOSING INTO THE PACIFIC NORTHWEST. AHEAD
OF THE UPPER LOW...850MB MOISTURE HAD SPREAD NORTHWARD FROM OK/TX
INTO NEB/IA...WITH 850MB WINDS UP TO 50-60KT IN EASTERN KS/EASTERN
NEB. SURFACE LOW AT 19Z WAS CENTERED IN NORTH CENTRAL NEB...WITH
COLD FRONT LAGGING FROM SOUTHWEST NEB THROUGH WESTERN KS TO THE
OK/TX PANHANDLES. SURFACE DEWPOINTS IN EASTERN NEB/WESTERN IA ALONG
AND SOUTH OF I-80 WERE IN THE 60S.
MAIN FORECAST CONCERN IS CONVECTIVE POTENTIAL THIS EVENING...WITH
RAIN LINGERING INTO TONIGHT IN THE SOUTHEASTERN CWA. THOUGH UPPER-
LEVEL WAVE IS OPENING...IT REMAINS POTENT. RAP ANALYSIS INDICATES
MLCAPE OF 1000+ J/KG REACHING SOUTH CENTRAL NEB. DEEP-LAYER
EFFECTIVE BULK SHEAR CERTAINLY IS POTENT...AT OR ABOVE 40KT ACROSS
MOST OF SOUTHEAST NEB/SOUTHWEST IA. INTERMITTENT CLOUDS HAVE BEEN
IN PLACE ALL ACROSS THE AREA...BUT ENOUGH SUN IS BREAKING THROUGH TO
ALLOW SOME HEATING AND DESTABILIZATION. THINK CONVECTION COULD
DEVELOP IN CENTRAL KS IN THE LATE AFTN...THEN MOVE NORTHEASTWARD
INTO SOUTHEAST NEB AND EVENTUALLY SOUTHEAST IA THROUGH THE EVENING
HOURS. DO THINK THAT STORMS THAT MOVE INTO THE AREA COULD CARRY A
RISK OF HAIL...AND ALSO WIND...ESPECIALLY AS THEY ORGANIZE INTO A
LINE LATER THIS EVENING AHEAD OF THE FRONT...AS ORIENTATION OF SHEAR
VECTOR IS NEARLY PARALLEL TO FRONTAL FORCING. DO THINK TORNADO
POTENTIAL IS LIMITED BY VEERED SURFACE WIND PROFILE. STORMS SHOULD
PROGRESS ACROSS THE AREA THROUGH THE EVENING HOURS. ECMWF CONTINUES
TO HOLD ONTO A DEFORMATION-ZONE AREA OF RAIN BEHIND THE UPPER-
LOW...WITH A STRONGER LOW THAN NAM/GFS/GEM/UKMET. HELD ONTO A
SHOWER MENTION LATE TONIGHT IN THE SOUTHEAST CWA AS A NOD TO THE
STRONGER ECMWF SOLUTION.
UPPER-LEVEL SYSTEM LACKS ANY KIND OF COLD AIR PUSH BEHIND IT...AND
MILD TEMPERATURES WILL CONTINUE INTO THE WORK WEEK. TEMPS SHOULD
PEAK ON MONDAY UNDER WARM AIR ADVECTION AND LOW-LEVEL
SOUTH/SOUTHWESTERLY FLOW...WITH HIGHS LIKELY TO CRACK 80 IN PARTS OF
EASTERN NEB. A WEAK FRONTAL PASSAGE ASSOCIATED WITH A WEAK UPPER-
LEVEL WAVE WILL SKIRT THROUGH THE AREA ON TUESDAY...BRINGING MAYBE A
FEW EXTRA CLOUDS AND A SLIGHT DIP IN TEMPERATURES TO LESS ABOVE-
NORMAL READINGS.
MAYES
LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
GLOBAL MODELS ARE IN BETTER AGREEMENT TODAY IN THE LARGE SCALE FLOW
ACROSS THE CONUS FOR THE SECOND HALF OF THE WORK WEEK. MOST
OPERATIONAL AND ENSEMBLES MODELS NOW AMPLIFY A STRONG SHORTWAVE
TROUGH DIVING INTO THE CNTRL US ON WED. THIS DRIVES A STRONG COLD
FRONT THROUGH THE FA ON WED. WE WILL CONT WITH THE CHC OF SHOWERS
FOR LATE TUE NIGHT IN THE NORTH...SPREADING ACROSS A GOOD PART OF
OUR FA FOR WED. WE MAY SEE THE SHOWERS SHUT OFF FOR A TIME ON WED
NIGHT AS THE MID LEVEL DRY-SLOT WORKS THROUGH THE FORECAST AREA. BUT
THE WRAP-AROUND/DEFORMATION ZONE LOOKS TO IMPACT AT LEAST OUR
NORTHERN AND ERN FA THU AND THU NIGHT WITH CHC POPS IN THE FORECAST.
IT APPEARS THEN THAT THIS PERIOD OF THE FORECAST WILL SEE WELL BELOW
NORMAL TEMPERATURES FOR HIGHS...ESPECIALLY ON THU WHERE HIGHS MAY
NOT GET OUT OF THE MID 40S WITH BREEZY CONDITIONS. WILL LEAVE THE
LATER HALF OF FRI AND INTO SAT DRY ATTM WITH SOME MODERATION TO
TEMPERATURES.
BOUSTEAD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
246 AM EDT SUN OCT 14 2012
.SYNOPSIS...
RAIN WILL BE WIDESPREAD ACROSS CENTRAL NEW YORK AND PARTS OF
NORTHEAST PENNSYLVANIA EARLY THIS MORNING AS A WARM FRONT CROSSES
THE REGION. BEHIND THE WARM FRONT, A FEW SHOWERS WILL BE POSSIBLE
SUNDAY MORNING. OTHERWISE, IT WILL BE WARMER WITH HIGHS IN THE 60S
TO LOWER 70S. A COLD FRONT WILL CROSS THE REGION MONDAY, WITH A
CHANCE FOR MORE SHOWERS, ALONG WITH A RETURN TO COOLER WEATHER.
&&
.NEAR TERM /THROUGH TODAY/...
RADARS SHOW RAINS INCREASING ACROSS MUCH OF CENTRAL NEW YORK IN
RESPONSE TO INCREASING ISENTROPIC LIFT AND MOISTURE ADVECTION.
THIS ISEN LIFT/MOISTURE ADVECTION WAS IN ADVANCE OF A SHORT WAVE
RIPPLING THROUGH NORTHERN ONTARIO. THIS FEATURE WAS INCREASING
UPPER CONFLUENCE TO OUR NORTHEAST ENHANCING THE THERMALLY DIRECT
JET STREAK CIRCULATION FOR NY AND PA. THIS WAS ALLOWING FOR THE
STRGR ISEN LIFT AND PRECIPITATION TO BREAK OUT. BY AROUND
9Z...THIS WAVE PASSES AND THE WAA IMPULSE WILL WEAKEN AND THE MORE
WIDESPREAD RAINS WILL TAPER TO SCATTERED SHOWERS/SPRINKLES. THIS
OCCURS AT THE SAME TIME THAT THE STRONGER UPPER LEVEL LOW AND
ASSOCIATED SURFACE CYCLONE IN THE PLAINS INTENSIFIES AND INCREASES
THE DOWNSTREAM RIDGING ALOFT OVER THE EAST. THIS WILL ALLOW THE
WARM FRONT TO EVENTUALLY PUSH NORTH OF THE REGION SUNDAY LATER IN
THE MORNING AS THE ISENTROPES WILL EASILY BE ADVECTED NORTH AND
NOT BE HELD UP BY A JET STREAK AND ASSOCIATED GEOSTROPHIC
ADJUSTMENTS.
LATEST HRRR HAD THE BEST HANDLE ON THE RADAR ECHOES AT THIS TIME IN
OHIO WHICH WAS MUCH FARTHER SOUTH THAN THE NAM...GFS...AND OTHER
CONVECTION ALLOWING HIGH RES MODELS. SINCE THIS MODEL SEEMS TO HAVE
INITIALIZED WELL AND THE PRECIP IS FARTHER S...I WENT ALONG WITH
THE IDEA OF HAVING MORE PRECIP SLIDE ACROSS NRN PA IN LINE WITH
THE LATEST HRRR LATER TONIGHT. I RAISED POPS IN NE PA FOR LATER TONIGHT
AS A RESULT.
FOR SUNDAY...WARM FRONT CLEARS REGION TO THE NORTH. ALL HIGHER
RESOLUTION MODELS PULL PRECIP NORTH OF THE WFO BGM FORECAST AREA
BY ARND 18Z. SO I HAVE SUN PM DRY AND MILD AND CUT BACK ON POPS
FROM PREVIOUS FORECAST. OTHERWISE NO MAJOR CHANGES.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
330 PM UPDATE...
STRONGEST LIFT MOVES NORTHEAST AS A WARM FRONT LIFTS INTO NNY SUNDAY.
WILL DECREASE POPS FROM SOUTHWEST TO NORTHEAST EARLY...AND
MAINTAIN CHANCE POPS THROUGH THE AFTERNOON ONLY ACROSS NORTHERN
ONEIDA COUNTY. WE WILL REMAIN BREEZY THROUGH EARLY
AFTERNOON...AGAIN WITH THE HIGHER WINDS OVER THE HIGHEST TERRAIN.
WE LOOK FAIRLY DRY THROUGH SUNDAY NIGHT WITH POPS INCREASING
TOWARD DAYBREAK MONDAY AS A COLD FRONT ENTERS THE WESTERN PART OF
THE CWA.
NOT OVERLY IMPRESSED WITH THE FRONTAL PASSAGE MONDAY AND WILL KEEP
POPS IN THE CHANCE RANGE. BY AFTERNOON MOST OF THE CWA SHOULD BE
DRY WITH THE EXCEPTION OF THE FAR SOUTHEAST AS SOME MOISTURE MOVES
UP THE COAST. A TROF MOVES THROUGH MONDAY NIGHT WITH A FEW
SHOWERS. WITH 850S IN THE 0C TO -2C RANGE TUESDAY ON A NORTHWEST
FLOW LAKE SHOWERS WILL BE AROUND BUT STRONG NVA ON THE BACKSIDE OF
THE UPPER TROF WILL LIMIT THE POTENTIAL TO JUST SLIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
2 AM UPDATE...
LITTLE CHANGE TO THE LONG TERM GRIDS. HIGH PRESSURE WEDNESDAY THEN
TIMING DIFFERS ON A STACKED LOW AND OCCLUDED FRONT. GFS SAYS
THURSDAY WHILE EURO AND HPC SAY FRIDAY. HAVE LEFT THE POPS CLOSE
TO BEFORE WITH INCREASING POPS FROM WEST TO EAST THU THEN CHC POPS
THU NGT ON. SLOW COOL DOWN FRIDAY TO SUNDAY BUT THE AIR MASS WILL
BE MODERATED AS THE LOW WEAKENS AND LIFTS NORTHEAST INTO SRN
QUEBEC. ALSO CLOUDS WILL AGAIN DOMINATE SO LESS SWING IN TEMPS.
330 PM UPDATE...
MAIN FEATURE OF NOTE TO WATCH DURING THIS EXTENDED PERIOD WILL BE AN
UPPER LEVEL CLOSED LOW MOVING SLOWLY EAST FROM THE MIDWEST. MODEL
TRENDS HAVE BEEN TO SLOW THIS FEATURE DOWN WITH TIME. LATEST GFS AND
12Z ECMWF INDICATE THAT THIS SYSTEM MAY NOT BRING ANY RAIN TO OUR
AREA UNTIL FRIDAY. BASED ON THIS WILL GO WITH A DRY MILD FORECAST
WEDNESDAY THROUGH THURSDAY WITH ABOVE NORMAL HIGHS MAINLY IN THE MID
TO UPPER 60S AND LOWS IN THE 40S TO LOWER 50S. WILL BRING HIGH
CHANCE POPS ACROSS THE AREA FRIDAY AND CONTINUED MILD WITH HIGHS
MAINLY IN THE 60S. THE WEEKEND LOOKS COOLER AND CONTINUED UNSETTLED
WITH A CHANCE OF SHOWERS AS THE CLOSED LOW MOVES EAST ACROSS THE
AREA.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
130 AM UPDATE...
GENERAL TREND FROM VFR TO MVFR CIGS AND MAYBE MVFR VSBYS
EARLY THIS MORNING THEN BACK TO VFR BY 16Z. CLOUDS AND LIGHT TO
BRIEF MODERATE RAIN WITH A WARM FRONT LIFTING NORTHEAST THROUGH
THE AREA. KAVP WILL BE OUT OF MOST OF THE RAIN AND SHOULD REMAIN
VFR. NY SITES WILL FALL TO MVFR CIGS BETWEEN 8 AND 10Z THEN RETURN
TO VFR BETWEEN 14 AND 16Z.
IFR CHANCES ARE LOW AND HAVE LEFT OUT. VERY SMALL CHANCES FOR ITH
AND BGM TO FALL BELOW 1K FT CIG. RME A LITTLE BETTER CHANCE OF IFR
CIG BUT WITH A SE FLOW DOWNSLOPED. RME NOW HAS AN IFR VSBY BUT
THAT IS ONLY WITH THE MODERATE RAIN AND WILL NOT LAST LONG.
WINDS SE TO S AT 5 TO 10 KTS EARLY THIS MORNING. SOUTH WINDS
AROUND 10 KTS DURING THE DAY THEN BACK TO SE TO S AT 5 TO 10 KTS
THIS EVENING.
OUTLOOK...
LATE TONIGHT TO TUESDAY...MVFR AND MAYBE IFR MOSTLY LATE AT NIGHT.
SOME SHOWERS WITH A FRONT MONDAY COULD BRING BRIEF MVFR.
WED AND THU...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...HEDEN
LONG TERM...MSE/TAC
AVIATION...TAC
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1205 AM CDT SUN OCT 14 2012
.DISCUSSION...
SEE 06Z AVIATION DISCUSSION...
&&
.AVIATION...
ISOLATED STREAMER SHOWERS MOVING ON SHORE FROM THE GULF MAY
CONTRIBUTE TO OCCASIONAL MVFR CIGS AT GLS OVER NIGHT. WIDELY
SCATTERED SHOWERS ARE ALSO DEVELOPING TO THE WEST OF CLL. THIS
ACTIVITY SHOULD MOVE IN TO CLL VICINITY AFTER 08Z. TERMINALS WEST
OF HOUSTON METRO AREA WILL LIKELY HAVE MVFR CIGS DURING PRE-DAWN
HOURS. A WEAK COLD FRONT SHOULD PASS THROUGH CLL AND UTS BETWEEN
15 AND 18Z AND THE HOUSTON METRO AREA BETWEEN 18 AND 22Z. EXPECT
SCATTERED SHOWER ACTIVITY AHEAD ON THE FRONT WITH THUNDERSTORM
ACTIVITY POSSIBLE WITH FRONTAL PASSAGE. AT THIS TIME...EXPECT
MOST ACTIVITY TO BE LIMITED TO NORTHERN AND WESTERN PORTIONS OF
THE FORECAST AREA WITH DECREASING ACTIVITY AS THE FRONT APPROACHES
THE COAST.
WINDS DURING THE DAY ON SUNDAY SHOULD BE FROM THE SOUTH NEAR 10
KNOTS...BECOMING WESTERLY AND NORTHWESTERLY FOLLOWING FRONTAL
PASSAGE. 44
&&
.PREV DISCUSSION... /ISSUED 1010 PM CDT SAT OCT 13 2012/
DISCUSSION...
THE COLD FRONT WAS CURRENTLY THROUGH THE PANHANDLE AND MOVING
INTO CENTRAL AND NORTHERN TX. ISOLATED THUNDERSTORMS THAT OCCURRED
OVER BURLESON AND BRAZOS COUNTIES EARLIER THIS EVENING HAVE
DIMINISHED. DID HAVE A CONFIRMED REPORT OF A RAIN WRAPPED TORNADO
WITH THE STORM BETWEEN DIME BOX AND CALDWELL...THAT ACTUALLY
STARTED IN LEE COUNTY NEAR LEXINGTON. KUDOS TO WFO EWX FOR THE
ORIGINAL HEADS UP AND THE SPOTTER REPORTS IN LEE COUNTY THAT
HELPED US CONFIRM THE RADAR SIGNATURE AND WARNING DECISIONS FOR
BURLESON COUNTY. ALSO APPRECIATED THE WEATHER SPOTTER IN BURLESON
COUNTY FOR THE TWO REPORTS DURING THE TORNADO WARNING. HELICITY
VALUES ON THE 00Z AREA SOUNDINGS DID INDICATE SOME POTENTIAL...
WITH 0 TO 3 KM VALUES AT 350 AT FWD...133 AT CRP...AND 257 AT
SHV. THE 18Z NAM BUFR MODEL ACTUALLY SHOWED THE BEST POTENTIAL ON
THE CLL FORECAST SOUNDING FOR EARLIER THIS EVENING.
DO EXPECT THE RAIN CHANCES TO INCREASE OVERNIGHT OVER THE
NORTHWESTERN HALF OF THE FORECAST AREA AS THE FRONT APPROACHES
SE TX. THE RAP MESO-SCALE ANALYSIS INDICATES THIS TREND BY SHOWING
PW/S NEARING 1.8 INCHES OVER THE WESTERN COUNTIES.
THE CURRENT RADAR ALSO SHOWS STREAMER SHOWERS DEVELOPING OFF THE
COAST AS THE MOISTURE ADVECTION WAS INCREASING. DECIDED TO UPDATE
THE FORECAST TO INCLUDE ISOLATED SHOWERS IN THE 10 PERCENT POP
AREAS. THESE ARE LOCATED MAINLY TOWARD THE COAST THIS EVENING...
AND ALONG AND OFF THE COAST OVERNIGHT TONIGHT AND SUNDAY MORNING.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 73 86 62 84 59 / 60 50 10 10 0
HOUSTON (IAH) 73 87 64 86 60 / 20 40 30 10 0
GALVESTON (GLS) 76 86 72 83 71 / 10 30 30 10 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 10 AM CDT SUNDAY FOR
THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60
NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT
20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...40
AVIATION/MARINE...44
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
452 AM CDT SUN OCT 14 2012
.UPDATE...FOR TODAY
452 AM CDT SUN OCT 14 2012
14.06Z NAM...14.08Z RAP AND RADAR TRENDS SHOWING THAT THE
DEFORMATION BAND IS SHIFTING FARTHER NORTHWEST. AFTER SEEING THE
14.06Z NAM...DID TREND THE FORECAST MORE TOWARDS ITS SCENARIO.
HOWEVER...IT IS POSSIBLE THE DEFORMATION BAND GOES FARTHER
NORTHWEST. IN ADDITION...AS WE HEAD INTO THE AFTERNOON AND IN
PARTICULAR THE LATE AFTERNOON HOURS...THE BAND MAY LAST LONGER IN
WISCONSIN THAN CURRENTLY FORECAST. THIS WILL HAVE TO BE MONITORED.
ALSO OF NOTE IS THE QPF WITH THIS DEFORMATION BAND. THE RAIN AS
PREVIOUSLY MENTIONED IN THE SHORT TERM SHOULD ONLY INTENSIFY AS THE
UPPER LOW NOW NEAR THE KANSAS CITY AREA APPROACHES. CROSS-SECTIONS
OF FN VECTORS SHOW A STRONG FRONTOGENESIS-FRONTOLYSIS COUPLET AT 12Z
AND 15Z...WHILE PLAN VIEWS OF THE 310 K SURFACE AND 500MB
TEMPERATURE SHOW A TROWAL SIGNATURE. AS SUCH...FROM 12-18Z TODAY WE
COULD BE SEEING SOME PRETTY HEAVY RAIN...ESPECIALLY COMPARED WITH
WHAT WE HAVE OBSERVED FOR THE PAST FEW MONTHS. THE LAST TIME LA
CROSSE TALLIED MORE THAN 1 INCH OF RAIN WAS AUGUST 4TH. HAVE THE
FORECAST SET AT A MAX AROUND 1.7 INCHES NEAR VIROQUA TODAY...BUT THE
NAM SUGGESTS IT COULD BE EVEN UPWARDS OF 3 INCHES. THUS QPF WILL
NEED MONITORING TOO. THE RAIN COULD RESULT IN PONDING OF WATER ON
ROADWAYS...ESPECIALLY WHERE THERE ARE LEAVES CLOGGING STORM DRAINS.
&&
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
258 AM CDT SUN OCT 14 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION TODAY AS WELL AS
PRECIPITATION CHANCES FOR MONDAY NIGHT THROUGH TUESDAY NIGHT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING BUILDING UP ACROSS THE WESTERN U.S. INTO BRITISH
COLUMBIA...A NORTHERN STREAM TROUGH OVER SOUTH CENTRAL CANADA AND
NORTH DAKOTA...AND AN UPPER LOW NEAR TOPEKA KS. ALSO OF INTEREST IS
120KT JET STREAK AROUND 200MB OVER LAKE SUPERIOR ACCORDING TO THE
RAP. THE COMBINATION OF UPPER DIVERGENCE IN THE RIGHT ENTRANCE
REGION OF THIS UPPER JET...THE PRESENCE OF LOW TO MID LEVEL
FRONTOGENESIS OVER THE SOUTHERN HALF OF THE FORECAST AREA SEEN JUST
BY CONVERGENCE IN 850MB PROFILER AND VWP DATA...AND PLENTIFUL
MOISTURE NOTED BY GOES PRECIPITABLE WATER VALUES OF 1.4 INCHES IN
THE SAME PLACE IS RESULTING IN A BAND OF SHOWERS AND EMBEDDED
THUNDERSTORMS. BACK EDGE OF THIS PRECIPITATION ALONG A LINE
EXTENDED FROM CHARLES CITY TO VIROQUA AND WISCONSIN DELLS.
NORTHWEST OF THIS LINE...PRECIPITABLE WATER VALUES DROP OFF
DRAMATICALLY... DOWN TO AROUND 0.75 INCH IN WEST CENTRAL MINNESOTA.
IN FACT...SATELLITE IMAGERY DEPICTS CLEARING OVER WESTERN
MINNESOTA AND THE EASTERN DAKOTAS. AT THE SURFACE...A 998MB LOW
WAS PRESENT IN SOUTHWEST IOWA WITH A WARM FRONT EXTENDING
NORTHEAST INTO SOUTHWEST WISCONSIN.
TODAY...MODELS DEPICT THE NORTHERN STREAM TROUGH OVER SOUTH CENTRAL
CANADA DROPPING DOWN INTO MINNESOTA AND IOWA...WHICH HELPS TO KICK
THE UPPER LOW NEAR TOPEKA NORTHEASTWARD. BY 00Z...MODELS HAVE THE
UPPER LOW AND THE ASSOCIATED SURFACE LOW IN CENTRAL LAKE MICHIGAN...
SLIGHTLY SLOWER THAN SEEN YESTERDAY. THE FORECAST AREA...IN
PARTICULAR THE SOUTHEAST HALF...WILL STAY IN THE DEFORMATION ON THE
NORTHWEST SIDE OF THE LOW TRACK WHICH IS QUITE FAVORABLE FOR
PRECIPITATION. IN FACT...THE CURRENT BAND OF SHOWERS AND EMBEDDED
THUNDERSTORMS SHOULD INTENSIFY THIS MORNING AS DPVA INCREASES FROM
THE APPROACHING UPPER LOW. FRONTOGENESIS FIELDS ALSO STRENGTHEN IN
RESPONSE TO THE INCREASING DPVA. PRECIPITATION WILL TAPER OFF IN THE
AFTERNOON WEST TO EAST AS THE UPPER JET...FRONTOGENESIS AND THE
OVERALL SYSTEM MOVE EAST AWAY FROM THE AREA. DECENT AMOUNT OF QPF
EXPECTED TODAY IN SOUTHEAST SECTIONS OF THE FORECAST AREA GIVEN
THE STRONG FORCING THIS MORNING AND PRECIPITABLE WATER VALUES NEAR
1.5 INCHES. BLEND OF GUIDANCE SUGGESTS UPWARDS OF 1 INCH BETWEEN
12-18Z FROM OELWEIN TO PRAIRIE DU CHIEN AND BOSCOBEL. ALTHOUGH
CLEARING IS NOT TOO FAR AWAY...OVER WESTERN MINNESOTA...14.00Z
NAM/14.03Z RAP SOUNDINGS SUGGEST IT WILL TAKE ITS TIME SHIFTING
EAST AS MOISTURE STAYS TRAPPED BELOW A SUBSIDENCE INVERSION AT
5000 FT. WILL PLAY THIS MORE PESSIMISTIC ROUTE COMPARED TO THE
QUICKER CLEARING GFS GIVEN THAT CLIMATOLOGICALLY CLOUD COVER TENDS
TO HOLD AROUND LONGER. WITH PLENTY OF CLOUDS AND 850MB TEMPS
FALLING FROM 8-12C AT 12Z TO 2-4C AT 00Z...ANTICIPATE TEMPERATURES
TO NOT RISE MUCH. IN FACT...READINGS COULD FALL...ESPECIALLY OVER
THE EASTERN TWO THIRDS OF THE AREA WHICH STAND NO CHANCE OF SEEING
SUN.
TONIGHT AND MONDAY...RAPID EVOLUTION OF THE UPPER AIR PATTERN IS
FORECAST OVER THE AREA DURING THIS TIME. THE NORTHERN STREAM TROUGH
DROPPING INTO IOWA AT 00Z IS PROGGED TO DIG INTO ILLINOIS BY 12Z...
THEN RIDGING SEEN OVER BRITISH COLUMBIA RIGHT NOW EXPECTED TO SHIFT
OVER THE AREA BY 00Z TUESDAY. NOT ANTICIPATING ANY PRECIPITATION
WITH THE NORTHERN STREAM TROUGH...NOR WITH THE WARM ADVECTION
ACCOMPANYING THE UPPER RIDGE BUILDING IN ON MONDAY...AS TOO MUCH
SUBSIDENCE AND DRYING FLOWS IN BEHIND THE CURRENT STORM SYSTEM.
WOULD HAVE SOME CONCERN ABOUT VALLEY FOG TONIGHT WITH SKIES LIKELY
TO CLEAR FROM WEST TO EAST AND LINGERING MOISTURE FROM TODAYS RAIN.
HOWEVER...THERE IS TOO MUCH OF A NORTHWEST BREEZE BETWEEN THE
DEPARTING STORM SYSTEM AND A SURFACE HIGH PRESSURE RIDGE BUILDING
INTO WESTERN MINNESOTA BY 12Z. THIS BREEZE SHOULD HELP KEEP
TEMPERATURES FROM DROPPING TOO MUCH AS WELL. GENERALLY FOLLOWED A
BLEND OF GUIDANCE FOR LOWS. WITH THE PASSAGE OF THE SURFACE RIDGE ON
MONDAY...MORE SUN AND 850MB TEMPS CLIMBING TO 4C EAST TO 7C WEST BY
00Z...SHOULD SEE A WARMER DAY. THE AFOREMENTIONED LATE IN THE DAY
850MB TEMPS SUPPORT HIGHS IN THE MID 50S TO LOWER 60S. THESE ARE
LOWER THAN PREVIOUSLY FORECAST BECAUSE MODELS ARE SLOWER IN BRINGING
THE WARMER AIR IN.
MONDAY NIGHT AND TUESDAY...MODELS DEPICT A SHORTWAVE TROUGH OVER
NORTH DAKOTA AT 00Z TUESDAY...PARTLY RESPONSIBLE FOR THE UPPER RIDGE
THAT MOVED INTO THE AREA ON MONDAY...MOVING QUICKLY TO THE EAST
AND PERHAPS EVEN WEAKENING. THIS WEAKENING MAKES SENSE AS THERE IS A
MUCH MORE IMPRESSIVE AND POTENT UPPER TROUGH DIGGING DOWN INTO THE
NORTHERN U.S. ROCKIES. QUESTION IS IF ANY PRECIPITATION WILL OCCUR
WITH THAT SHORTWAVE TROUGH THAT TRACKS TO OUR NORTH. 14.00Z NAM
KEEPS ALL PRECIPITATION WELL TO THE NORTH...FROM NORTHERN MINNESOTA
INTO THE U.P.. THE 14.00Z GFS SHOWS SOME PRECIP CROSSING THE
NORTHERN SECTIONS OF THE FORECAST AREA...THOUGH VARIOUS ISENTROPIC
LIFT LEVELS FROM 290-310K SHOW VERY LITTLE LIFT OCCURRING WITH IT.
PLUS...THE PRECIPITATION IS FALLING OUT OF A 9000 FT CEILING. ALL
MODELS HAVE CERTAINLY TRENDED DRIER AND LESS IMPRESSIVE WITH THE
SHORTWAVE TROUGH. HAVE DECIDED TO MAINTAIN SOME 20 PERCENT
CHANCES...MAINLY ON TUESDAY NORTHEAST OF I-94. IDEA HERE BEING THAT
IT MAY TAKE AWHILE TO SATURATE THE LOWER LEVELS WITH THE WARM
ADVECTION TO ALLOW PRECIPITATION TO OCCUR. ALTHOUGH WE MAY GET
LITTLE PRECIPITATION OVERALL WITH THE SHORTWAVE TROUGH...THERE IS
DEFINITE WARMING COMING INTO THE FORECAST AREA WITH IT. 850MB TEMPS
CLIMB TO AT LEAST 10-14C BY 18Z TUESDAY. WITH POTENTIAL FOR ANY WARM
ADVECTION MID CLOUDS TO CLEAR OUT ON TUESDAY...COULD SEE DECENT
MIXING. AS SUCH...HAVE BUMPED UP TEMPERATURES ABOUT 5 DEGREES TO
COME IN BETTER ALIGNMENT WITH GUIDANCE. MONDAY NIGHT STILL LOOKS
RELATIVELY MILD THANKS TO THE INCREASE IN MID CLOUDS AND SOME
SOUTHERLY BREEZE.
TUESDAY NIGHT...THE POTENT TROUGH DIGGING INTO THE NORTHERN ROCKIES
ON TUESDAY IS PROGGED TO DIVE DOWN INTO THE DAKOTAS. IMPRESSIVE
WINDY AND COLD ADVECTION SETUP BEHIND IT WITH MODEL PROGS OF A 980S
MB LOW NEAR LAKE WINNIPEG AND 1025-1030MB SURFACE HIGH OVER THE
NORTHWESTERN U.S.. FOR OUR AREA...WE ARE IN THE WARM ADVECTION SETUP
AHEAD OF THE LOW WITH INDICATIONS OF 500MB HEIGHTS FALLING AFTER
MIDNIGHT. THEREFORE...ANTICIPATING SOME MID AND HIGH CLOUDS
SPREADING WEST TO EAST AGAIN...LIKE MONDAY NIGHT. LOWER LEVEL
SATURATION BECOMES AN ISSUE FOR ANY PRECIPITATION TO FALL OUT OF
THESE CLOUDS. BOTH THE 14.00Z GFS AND NAM SUGGEST SOME LIGHT QPF CAN
FALL ACROSS NORTHWEST SECTIONS OF THE FORECAST AREA BETWEEN 06-12Z
WEDNESDAY...WHICH HAVE BEEN ACKNOWLEDGED WITH A 15-20 PERCENT
CHANCE. OTHERWISE...DRY CONDITIONS WITH A LIGHT SOUTHERLY BREEZE
WILL BE THE RULE. COMBINATION OF THAT SOUTHERLY BREEZE AND
CLOUDS...ALONG WITH DEWPOINTS WHICH SHOULD BE UP IN THE 40S IS
EXPECTED TO HELP HOLD LOWS UP IN THE MID 40S TO LOW 50S.
.LONG TERM...WEDNESDAY THROUGH SATURDAY NIGHT
258 AM CDT SUN OCT 14 2012
MAIN STORY FOR THE EXTENDED REVOLVES AROUND THAT POTENT UPPER TROUGH
DROPPING DOWN INTO THE DAKOTAS TUESDAY NIGHT. 14.00Z
ECMWF/GFS/CANADIAN AND GFS ENSEMBLES ALL SHOW THIS TROUGH DIGGING
INTO THE UPPER MISSISSIPPI RIVER VALLEY AND EASTERN MISSOURI RIVER V
REGIONS BY 12Z THURSDAY. AS THIS TROUGH DIGS...IT GRADUALLY PULLS UP
MORE AND MORE MOISTURE FROM THE GULF OF MEXICO. THEREFORE...
PRECIPITATION WITH IT SEEMS LIKELY. BIGGEST PROBLEM IS EVOLUTION OF
THE VARIOUS WARM AND COLD CONVEYOR BELTS AS THIS SYSTEM WRAPS
UP...WITH POTENTIAL OF A DRY SLOT COMING AROUND THE UPPER LOW TOO.
FOLLOWED THE CONSENSUS APPROACH FOR NOW WHICH INCREASES CHANCES TO
AROUND 50 ON WEDNESDAY...WITH THE EXPECTED WARM CONVEYOR BELT...
LOWER 30-40 PERCENT CHANCES ON WEDNESDAY NIGHT WITH A POSSIBLE DRY
SLOT...THEN 50 PERCENT CHANCES OVER MINNESOTA WITH THE COLD CONVEYOR
BELT TO 30 PERCENT CHANCES IN SOUTHEAST SECTIONS OF THE FORECAST
AREA WITH POSSIBLE DRY SLOT ON THURSDAY. AS TIME GETS CLOSER...THESE
CHANCES WILL NEED TO BE FURTHER REFINED WITH INCREASES AGAIN LIKELY.
WEDNESDAY STILL LOOKS RELATIVELY WARM BEING IN THE WARM CONVEYOR
BELT AND 850MB TEMPS UPWARDS OF 8-12C. MOST LOCATIONS SHOULD REACH
THE MID 50S TO MID 60S RANGE...WARMEST EAST WHERE PRECIPITATION
BEGINS LATER. COOLER WEATHER THEN ON TAP FOR THURSDAY WITH THE UPPER
TROUGH IN PLACE AND POSSIBLE PRECIPITATION. ALSO ADDED A MENTION OF
THUNDER TO NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN ON WEDNESDAY
WHERE BOTH THE 14.00Z GFS/ECMWF DEPICT SOME MUCAPE BUILDING UP.
AFTER THURSDAY...QUESTION IS HOW FAST THE UPPER LOW/TROUGH PUSHES
EAST. THE 14.00Z ECMWF/CANADIAN HAVE RIDGES AMPLIFYING ACROSS THE
WESTERN U.S. AND FROM NEW ENGLAND INTO QUEBEC...EFFECTIVELY BLOCKING
THE TROUGH FROM REALLY GOING ANYWHERE. THE 14.00Z GFS AND QUITE A
FEW OF ITS ENSEMBLE MEMBERS DO NOT HAVE AS MUCH RIDGING OVER NEW
ENGLAND AND QUEBEC...THUS ALLOWING THE TROUGH TO LIFT OUT. THINK
THIS LATTER SCENARIO IS TOO FAST AND THUS LEANING THE FORECAST MORE
TOWARDS THE CONSISTENT ECMWF/CANADIAN SOLUTIONS. THIS RESULTS IN
MAINTAINING COOL WEATHER WITH HIGHS IN THE LOW TO MID 50S ALONG WITH
LOW CHANCES OF PRECIPITATION THROUGH SATURDAY. REASON FOR THE LOW
PRECIPITATION CHANCES...GENERALLY 20-30...IS A COMBINATION OF MODEL
UNCERTAINTY ON THE EVOLUTION/TRACK OF THE UPPER LOW/TROUGH AS WELL
AS SUGGESTIONS OF THE UPPER LOW/TROUGH FILLING WITH TIME.
&&
.AVIATION...THROUGH 06Z MONDAY
1147 PM CDT SAT OCT 13 2012
AREA OF SHOWERS WITH A FEW THUNDERSTORMS ADVANCING NORTHEAST
TOWARD THE AREA OUT OF IOWA LATE THIS EVENING. EXPECT THIS WILL
CONTINUE INTO THE AREA AND POSSIBLY EXPAND AS THE FRONTOGENESIS
IN THE 700-500 MB LAYER STRENGTHENS THROUGH THE NIGHT AND THERE
WILL BE A CONTINUED UP GLIDE OF 2 TO 5 UBAR/S ON THE 300K
ISENTROPIC SURFACE. THE 14.00Z NAM SUGGESTS THE MU CAPE WILL STAY
TO THE SOUTH SO WILL NOT SHOW ANY THUNDER. THE CONCERN IS WHERE
IS THE BACK EDGE OF THE RAIN GOING TO SET UP. THE NAM SUGGESTS
THAT THE RAIN WILL MAKE IT INTO KLSE BUT NOT KRST. FOR THE MOST
PART...THE LAST FEW RUNS OF THE HRRR AGREE WITH THIS TREND BUT THE
14.01Z DOES SUGGEST THE POTENTIAL FOR SOME SHOWERS TO GET TO KRST
BEFORE 12Z. THUS PLAN TO BRING THE SHOWERS INTO KLSE OVERNIGHT AND
CONTINUE THEM THROUGH MUCH OF SUNDAY MORNING AND WILL SHOW A SHORT
PERIOD LATE TONIGHT WHEN THE SHOWERS COULD POSSIBLY GET INTO KRST.
NOT EXPECTING CEILINGS TO DO MUCH OVERNIGHT AND REMAIN IFR AT BOTH
TAF SITES. FORECAST SOUNDINGS DO NOT SHOW MUCH IMPROVEMENT
OCCURRING UNTIL SUNDAY AFTERNOON WHEN THE LOW LEVEL INVERSION
STARTS TO MIX OUT. LIFTED THE CEILINGS FROM IFR TO VFR BY LATE
AFTERNOON AND EXPECT THERE WILL BE A PERIOD OF MVFR IN BETWEEN BUT
THIS CAN BE DETAILED WITH LATER FORECASTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
258 AM CDT SUN OCT 14 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
UPDATE...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
259 AM CDT SUN OCT 14 2012
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
258 AM CDT SUN OCT 14 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION TODAY AS WELL AS
PRECIPITATION CHANCES FOR MONDAY NIGHT THROUGH TUESDAY NIGHT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING BUILDING UP ACROSS THE WESTERN U.S. INTO BRITISH
COLUMBIA...A NORTHERN STREAM TROUGH OVER SOUTH CENTRAL CANADA AND
NORTH DAKOTA...AND AN UPPER LOW NEAR TOPEKA KS. ALSO OF INTEREST IS
120KT JET STREAK AROUND 200MB OVER LAKE SUPERIOR ACCORDING TO THE
RAP. THE COMBINATION OF UPPER DIVERGENCE IN THE RIGHT ENTRANCE
REGION OF THIS UPPER JET...THE PRESENCE OF LOW TO MID LEVEL
FRONTOGENESIS OVER THE SOUTHERN HALF OF THE FORECAST AREA SEEN JUST
BY CONVERGENCE IN 850MB PROFILER AND VWP DATA...AND PLENTIFUL
MOISTURE NOTED BY GOES PRECIPITABLE WATER VALUES OF 1.4 INCHES IN
THE SAME PLACE IS RESULTING IN A BAND OF SHOWERS AND EMBEDDED
THUNDERSTORMS. BACK EDGE OF THIS PRECIPITATION ALONG A LINE
EXTENDED FROM CHARLES CITY TO VIROQUA AND WISCONSIN DELLS.
NORTHWEST OF THIS LINE...PRECIPITABLE WATER VALUES DROP OFF
DRAMATICALLY... DOWN TO AROUND 0.75 INCH IN WEST CENTRAL MINNESOTA.
IN FACT...SATELLITE IMAGERY DEPICTS CLEARING OVER WESTERN
MINNESOTA AND THE EASTERN DAKOTAS. AT THE SURFACE...A 998MB LOW
WAS PRESENT IN SOUTHWEST IOWA WITH A WARM FRONT EXTENDING
NORTHEAST INTO SOUTHWEST WISCONSIN.
TODAY...MODELS DEPICT THE NORTHERN STREAM TROUGH OVER SOUTH CENTRAL
CANADA DROPPING DOWN INTO MINNESOTA AND IOWA...WHICH HELPS TO KICK
THE UPPER LOW NEAR TOPEKA NORTHEASTWARD. BY 00Z...MODELS HAVE THE
UPPER LOW AND THE ASSOCIATED SURFACE LOW IN CENTRAL LAKE MICHIGAN...
SLIGHTLY SLOWER THAN SEEN YESTERDAY. THE FORECAST AREA...IN
PARTICULAR THE SOUTHEAST HALF...WILL STAY IN THE DEFORMATION ON THE
NORTHWEST SIDE OF THE LOW TRACK WHICH IS QUITE FAVORABLE FOR
PRECIPITATION. IN FACT...THE CURRENT BAND OF SHOWERS AND EMBEDDED
THUNDERSTORMS SHOULD INTENSIFY THIS MORNING AS DPVA INCREASES FROM
THE APPROACHING UPPER LOW. FRONTOGENESIS FIELDS ALSO STRENGTHEN IN
RESPONSE TO THE INCREASING DPVA. PRECIPITATION WILL TAPER OFF IN THE
AFTERNOON WEST TO EAST AS THE UPPER JET...FRONTOGENESIS AND THE
OVERALL SYSTEM MOVE EAST AWAY FROM THE AREA. DECENT AMOUNT OF QPF
EXPECTED TODAY IN SOUTHEAST SECTIONS OF THE FORECAST AREA GIVEN
THE STRONG FORCING THIS MORNING AND PRECIPITABLE WATER VALUES NEAR
1.5 INCHES. BLEND OF GUIDANCE SUGGESTS UPWARDS OF 1 INCH BETWEEN
12-18Z FROM OELWEIN TO PRAIRIE DU CHIEN AND BOSCOBEL. ALTHOUGH
CLEARING IS NOT TOO FAR AWAY...OVER WESTERN MINNESOTA...14.00Z
NAM/14.03Z RAP SOUNDINGS SUGGEST IT WILL TAKE ITS TIME SHIFTING
EAST AS MOISTURE STAYS TRAPPED BELOW A SUBSIDENCE INVERSION AT
5000 FT. WILL PLAY THIS MORE PESSIMISTIC ROUTE COMPARED TO THE
QUICKER CLEARING GFS GIVEN THAT CLIMATOLOGICALLY CLOUD COVER TENDS
TO HOLD AROUND LONGER. WITH PLENTY OF CLOUDS AND 850MB TEMPS
FALLING FROM 8-12C AT 12Z TO 2-4C AT 00Z...ANTICIPATE TEMPERATURES
TO NOT RISE MUCH. IN FACT...READINGS COULD FALL...ESPECIALLY OVER
THE EASTERN TWO THIRDS OF THE AREA WHICH STAND NO CHANCE OF SEEING
SUN.
TONIGHT AND MONDAY...RAPID EVOLUTION OF THE UPPER AIR PATTERN IS
FORECAST OVER THE AREA DURING THIS TIME. THE NORTHERN STREAM TROUGH
DROPPING INTO IOWA AT 00Z IS PROGGED TO DIG INTO ILLINOIS BY 12Z...
THEN RIDGING SEEN OVER BRITISH COLUMBIA RIGHT NOW EXPECTED TO SHIFT
OVER THE AREA BY 00Z TUESDAY. NOT ANTICIPATING ANY PRECIPITATION
WITH THE NORTHERN STREAM TROUGH...NOR WITH THE WARM ADVECTION
ACCOMPANYING THE UPPER RIDGE BUILDING IN ON MONDAY...AS TOO MUCH
SUBSIDENCE AND DRYING FLOWS IN BEHIND THE CURRENT STORM SYSTEM.
WOULD HAVE SOME CONCERN ABOUT VALLEY FOG TONIGHT WITH SKIES LIKELY
TO CLEAR FROM WEST TO EAST AND LINGERING MOISTURE FROM TODAYS RAIN.
HOWEVER...THERE IS TOO MUCH OF A NORTHWEST BREEZE BETWEEN THE
DEPARTING STORM SYSTEM AND A SURFACE HIGH PRESSURE RIDGE BUILDING
INTO WESTERN MINNESOTA BY 12Z. THIS BREEZE SHOULD HELP KEEP
TEMPERATURES FROM DROPPING TOO MUCH AS WELL. GENERALLY FOLLOWED A
BLEND OF GUIDANCE FOR LOWS. WITH THE PASSAGE OF THE SURFACE RIDGE ON
MONDAY...MORE SUN AND 850MB TEMPS CLIMBING TO 4C EAST TO 7C WEST BY
00Z...SHOULD SEE A WARMER DAY. THE AFOREMENTIONED LATE IN THE DAY
850MB TEMPS SUPPORT HIGHS IN THE MID 50S TO LOWER 60S. THESE ARE
LOWER THAN PREVIOUSLY FORECAST BECAUSE MODELS ARE SLOWER IN BRINGING
THE WARMER AIR IN.
MONDAY NIGHT AND TUESDAY...MODELS DEPICT A SHORTWAVE TROUGH OVER
NORTH DAKOTA AT 00Z TUESDAY...PARTLY RESPONSIBLE FOR THE UPPER RIDGE
THAT MOVED INTO THE AREA ON MONDAY...MOVING QUICKLY TO THE EAST
AND PERHAPS EVEN WEAKENING. THIS WEAKENING MAKES SENSE AS THERE IS A
MUCH MORE IMPRESSIVE AND POTENT UPPER TROUGH DIGGING DOWN INTO THE
NORTHERN U.S. ROCKIES. QUESTION IS IF ANY PRECIPITATION WILL OCCUR
WITH THAT SHORTWAVE TROUGH THAT TRACKS TO OUR NORTH. 14.00Z NAM
KEEPS ALL PRECIPITATION WELL TO THE NORTH...FROM NORTHERN MINNESOTA
INTO THE U.P.. THE 14.00Z GFS SHOWS SOME PRECIP CROSSING THE
NORTHERN SECTIONS OF THE FORECAST AREA...THOUGH VARIOUS ISENTROPIC
LIFT LEVELS FROM 290-310K SHOW VERY LITTLE LIFT OCCURRING WITH IT.
PLUS...THE PRECIPITATION IS FALLING OUT OF A 9000 FT CEILING. ALL
MODELS HAVE CERTAINLY TRENDED DRIER AND LESS IMPRESSIVE WITH THE
SHORTWAVE TROUGH. HAVE DECIDED TO MAINTAIN SOME 20 PERCENT
CHANCES...MAINLY ON TUESDAY NORTHEAST OF I-94. IDEA HERE BEING THAT
IT MAY TAKE AWHILE TO SATURATE THE LOWER LEVELS WITH THE WARM
ADVECTION TO ALLOW PRECIPITATION TO OCCUR. ALTHOUGH WE MAY GET
LITTLE PRECIPITATION OVERALL WITH THE SHORTWAVE TROUGH...THERE IS
DEFINITE WARMING COMING INTO THE FORECAST AREA WITH IT. 850MB TEMPS
CLIMB TO AT LEAST 10-14C BY 18Z TUESDAY. WITH POTENTIAL FOR ANY WARM
ADVECTION MID CLOUDS TO CLEAR OUT ON TUESDAY...COULD SEE DECENT
MIXING. AS SUCH...HAVE BUMPED UP TEMPERATURES ABOUT 5 DEGREES TO
COME IN BETTER ALIGNMENT WITH GUIDANCE. MONDAY NIGHT STILL LOOKS
RELATIVELY MILD THANKS TO THE INCREASE IN MID CLOUDS AND SOME
SOUTHERLY BREEZE.
TUESDAY NIGHT...THE POTENT TROUGH DIGGING INTO THE NORTHERN ROCKIES
ON TUESDAY IS PROGGED TO DIVE DOWN INTO THE DAKOTAS. IMPRESSIVE
WINDY AND COLD ADVECTION SETUP BEHIND IT WITH MODEL PROGS OF A 980S
MB LOW NEAR LAKE WINNIPEG AND 1025-1030MB SURFACE HIGH OVER THE
NORTHWESTERN U.S.. FOR OUR AREA...WE ARE IN THE WARM ADVECTION SETUP
AHEAD OF THE LOW WITH INDICATIONS OF 500MB HEIGHTS FALLING AFTER
MIDNIGHT. THEREFORE...ANTICIPATING SOME MID AND HIGH CLOUDS
SPREADING WEST TO EAST AGAIN...LIKE MONDAY NIGHT. LOWER LEVEL
SATURATION BECOMES AN ISSUE FOR ANY PRECIPITATION TO FALL OUT OF
THESE CLOUDS. BOTH THE 14.00Z GFS AND NAM SUGGEST SOME LIGHT QPF CAN
FALL ACROSS NORTHWEST SECTIONS OF THE FORECAST AREA BETWEEN 06-12Z
WEDNESDAY...WHICH HAVE BEEN ACKNOWLEDGED WITH A 15-20 PERCENT
CHANCE. OTHERWISE...DRY CONDITIONS WITH A LIGHT SOUTHERLY BREEZE
WILL BE THE RULE. COMBINATION OF THAT SOUTHERLY BREEZE AND
CLOUDS...ALONG WITH DEWPOINTS WHICH SHOULD BE UP IN THE 40S IS
EXPECTED TO HELP HOLD LOWS UP IN THE MID 40S TO LOW 50S.
.LONG TERM...WEDNESDAY THROUGH SATURDAY NIGHT
258 AM CDT SUN OCT 14 2012
MAIN STORY FOR THE EXTENDED REVOLVES AROUND THAT POTENT UPPER TROUGH
DROPPING DOWN INTO THE DAKOTAS TUESDAY NIGHT. 14.00Z
ECMWF/GFS/CANADIAN AND GFS ENSEMBLES ALL SHOW THIS TROUGH DIGGING
INTO THE UPPER MISSISSIPPI RIVER VALLEY AND EASTERN MISSOURI RIVER V
REGIONS BY 12Z THURSDAY. AS THIS TROUGH DIGS...IT GRADUALLY PULLS UP
MORE AND MORE MOISTURE FROM THE GULF OF MEXICO. THEREFORE...
PRECIPITATION WITH IT SEEMS LIKELY. BIGGEST PROBLEM IS EVOLUTION OF
THE VARIOUS WARM AND COLD CONVEYOR BELTS AS THIS SYSTEM WRAPS
UP...WITH POTENTIAL OF A DRY SLOT COMING AROUND THE UPPER LOW TOO.
FOLLOWED THE CONSENSUS APPROACH FOR NOW WHICH INCREASES CHANCES TO
AROUND 50 ON WEDNESDAY...WITH THE EXPECTED WARM CONVEYOR BELT...
LOWER 30-40 PERCENT CHANCES ON WEDNESDAY NIGHT WITH A POSSIBLE DRY
SLOT...THEN 50 PERCENT CHANCES OVER MINNESOTA WITH THE COLD CONVEYOR
BELT TO 30 PERCENT CHANCES IN SOUTHEAST SECTIONS OF THE FORECAST
AREA WITH POSSIBLE DRY SLOT ON THURSDAY. AS TIME GETS CLOSER...THESE
CHANCES WILL NEED TO BE FURTHER REFINED WITH INCREASES AGAIN LIKELY.
WEDNESDAY STILL LOOKS RELATIVELY WARM BEING IN THE WARM CONVEYOR
BELT AND 850MB TEMPS UPWARDS OF 8-12C. MOST LOCATIONS SHOULD REACH
THE MID 50S TO MID 60S RANGE...WARMEST EAST WHERE PRECIPITATION
BEGINS LATER. COOLER WEATHER THEN ON TAP FOR THURSDAY WITH THE UPPER
TROUGH IN PLACE AND POSSIBLE PRECIPITATION. ALSO ADDED A MENTION OF
THUNDER TO NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN ON WEDNESDAY
WHERE BOTH THE 14.00Z GFS/ECMWF DEPICT SOME MUCAPE BUILDING UP.
AFTER THURSDAY...QUESTION IS HOW FAST THE UPPER LOW/TROUGH PUSHES
EAST. THE 14.00Z ECMWF/CANADIAN HAVE RIDGES AMPLIFYING ACROSS THE
WESTERN U.S. AND FROM NEW ENGLAND INTO QUEBEC...EFFECTIVELY BLOCKING
THE TROUGH FROM REALLY GOING ANYWHERE. THE 14.00Z GFS AND QUITE A
FEW OF ITS ENSEMBLE MEMBERS DO NOT HAVE AS MUCH RIDGING OVER NEW
ENGLAND AND QUEBEC...THUS ALLOWING THE TROUGH TO LIFT OUT. THINK
THIS LATTER SCENARIO IS TOO FAST AND THUS LEANING THE FORECAST MORE
TOWARDS THE CONSISTENT ECMWF/CANADIAN SOLUTIONS. THIS RESULTS IN
MAINTAINING COOL WEATHER WITH HIGHS IN THE LOW TO MID 50S ALONG WITH
LOW CHANCES OF PRECIPITATION THROUGH SATURDAY. REASON FOR THE LOW
PRECIPITATION CHANCES...GENERALLY 20-30...IS A COMBINATION OF MODEL
UNCERTAINTY ON THE EVOLUTION/TRACK OF THE UPPER LOW/TROUGH AS WELL
AS SUGGESTIONS OF THE UPPER LOW/TROUGH FILLING WITH TIME.
&&
.AVIATION...THROUGH 06Z MONDAY
1147 PM CDT SAT OCT 13 2012
AREA OF SHOWERS WITH A FEW THUNDERSTORMS ADVANCING NORTHEAST
TOWARD THE AREA OUT OF IOWA LATE THIS EVENING. EXPECT THIS WILL
CONTINUE INTO THE AREA AND POSSIBLY EXPAND AS THE FRONTOGENESIS
IN THE 700-500 MB LAYER STRENGTHENS THROUGH THE NIGHT AND THERE
WILL BE A CONTINUED UP GLIDE OF 2 TO 5 UBAR/S ON THE 300K
ISENTROPIC SURFACE. THE 14.00Z NAM SUGGESTS THE MU CAPE WILL STAY
TO THE SOUTH SO WILL NOT SHOW ANY THUNDER. THE CONCERN IS WHERE
IS THE BACK EDGE OF THE RAIN GOING TO SET UP. THE NAM SUGGESTS
THAT THE RAIN WILL MAKE IT INTO KLSE BUT NOT KRST. FOR THE MOST
PART...THE LAST FEW RUNS OF THE HRRR AGREE WITH THIS TREND BUT THE
14.01Z DOES SUGGEST THE POTENTIAL FOR SOME SHOWERS TO GET TO KRST
BEFORE 12Z. THUS PLAN TO BRING THE SHOWERS INTO KLSE OVERNIGHT AND
CONTINUE THEM THROUGH MUCH OF SUNDAY MORNING AND WILL SHOW A SHORT
PERIOD LATE TONIGHT WHEN THE SHOWERS COULD POSSIBLY GET INTO KRST.
NOT EXPECTING CEILINGS TO DO MUCH OVERNIGHT AND REMAIN IFR AT BOTH
TAF SITES. FORECAST SOUNDINGS DO NOT SHOW MUCH IMPROVEMENT
OCCURRING UNTIL SUNDAY AFTERNOON WHEN THE LOW LEVEL INVERSION
STARTS TO MIX OUT. LIFTED THE CEILINGS FROM IFR TO VFR BY LATE
AFTERNOON AND EXPECT THERE WILL BE A PERIOD OF MVFR IN BETWEEN BUT
THIS CAN BE DETAILED WITH LATER FORECASTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
258 AM CDT SUN OCT 14 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
AREA FORECAST DISCUSSION
NWS TAUNTON MA
730 AM EDT SUN OCT 14 2012
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH ACROSS THE REGION THIS MORNING AND
WILL BE FOLLOWED BY BREEZY AND WARMER WEATHER LASTING INTO
MONDAY. A COLD FRONT WILL MOVE THROUGH MONDAY NIGHT FOLLOWED BY
MAINLY DRY AND MILD WEATHER TUESDAY THROUGH THURSDAY. MOISTURE
WILL INCREASE ALONG WITH SHOWERS POSSIBILITIES BY FRIDAY AND
SATURDAY AS A WEATHER SYSTEM APPROACHES FROM THE WEST.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED FORECAST TO ACCOUNT FOR CURRENT CONDITIONS. MODELS ARE
STRUGGLING WITH TEMPS IN THE NEAR TERMS. SEEMS THAT THE HRRR HAS
THE BEST HANDLE SO FAR. WARM FRONT IS CURRENTLY LIFTING
NORTHWARD...OVER THE SOUTH COAST AND ISLANDS RIGHT NOW. MAIN SWATH
OF PRECIP CONTINUES TO STREAM ACROSS THE REGION. HEAVIER AMOUNTS
HAVE OCCURRED ACROSS NH AND NORTHERN MASSACHUSETTS. EXPECT TREND TO
CONTINUE AND THINGS IMPROVING FROM SOUTHWEST TO NORTHEAST BY MID-
DAY.
PREV DISCUSSION...
INITIAL BATCH OF SHOWERS WHICH ARE MOVING THROUGH N ZONES ARE VERY
LIGHT WITH PRECIP AMOUNTS A TRACE TO A FEW HUNDREDTHS OF AN INCH.
HEAVIER SHOWERS WILL MOVE INTO THE REGION FROM NEW YORK THROUGH
MID MORNING. THE SHOWERS WILL BE CONCENTRATED N OF THE MASS PIKE
THIS MORNING WHERE BEST MOISTURE TRANSPORT AND MID LEVEL OMEGA IS
FOCUSED AHEAD OF THE WARM FRONT. MOISTURE AND LIFT DECREASES
SOUTHWARD TOWARD THE S COAST WHERE COVERAGE OF ANY SHOWERS WILL BE
LIMITED. POPS RANGE FROM CATEGORICAL N OF THE PIKE TO SLIGHT CHC
OVER THE ISLANDS. SHOWERS WILL LIFT N OF THE REGION BY THE
AFTERNOON AS DRY SLOT MOVES IN WITH PARTIAL SUNSHINE DEVELOPING S
OF THE PIKE DURING THE AFTERNOON...BUT MOCLDY SKIES FURTHER N.
IT WILL BE A WINDY DAY...ESPECIALLY IN THE COASTAL PLAIN AS 40 KT
LOW LEVEL JET MOVES ACROSS THE REGION. FAVORABLE LOW LEVEL LAPSE
RATES FROM SFC TO 925 MB WILL PROMOTE ENOUGH MIXING TO SUPPORT GUSTS
TO 30-35 KT...STRONGEST OVER THE CAPE/ISLANDS.
THE GUSTY SW WINDS WILL ADVECT MILDER AIR INTO THE REGION...BUT
PROBABLY NOT TO THE EXTENT THE NAM IS SUGGESTING. LEANED TOWARD
COOLER GFS/ECMWF WITH MAXES RANGING FROM MID/UPPER 50S FAR NORTH
TO MID 60S SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
TONIGHT...
A DRY AND MILD NIGHT EXPECTED AS REGION WILL REMAIN IN WARM SECTOR
AIRMASS AND FAR ENOUGH REMOVED FROM APPROACHING MOISTURE WITH THE
COLD FRONT TO THE WEST. AREAS OF STRATUS AND PATCHY FOG MAY
DEVELOP OVERNIGHT AS HIGHER DEWPOINT AIR ADVECTS NWD INTO REGION. IT
WILL BE UNSEASONABLY MILD WITH MINS MAINLY IN THE 50S AND CLOSE
TO 60 NEAR THE COAST.
MONDAY...
SHARP MID LEVEL TROF MOVES THROUGH THE GT LAKES WITH THE COLD
FRONT APPROACHING FROM THE WEST. A FEW SHOWERS ARE
POSSIBLE...MAINLY IN THE AFTERNOON AS MOISTURE AXIS AND DECREASING
STABILITY ALOFT MOVE INTO SNE...BUT BETTER CHANCE WILL LIKELY BE
MON NIGHT. WE WILL HAVE CHC POPS. DESPITE MOCLDY SKIES...IT WILL
BE A WARM AND HUMID DAY. 2M TEMPS SUPPORT MAXES IN THE UPPER 60S
TO LOWER 70S AND DEWPOINTS WILL INCREASE TO THE UPPER 50S AND
LOWER 60S WITH MID 60S DEWPOINTS POSSIBLE NEAR THE S COAST.
ANOTHER BREEZY DAY LIKELY IN THE COASTAL PLAIN WITH GUSTS TO 25
KT.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...
* SHOWERY WX RETURNS AS A COLD FRONT MOVE THROUGH MONDAY NIGHT.
* HIGH PRESSURE FOR MID-WEEK WITH MODERATING TEMPS.
* ANOTHER CHANCE FOR SHOWERS LATE FRIDAY INTO THE WEEKEND.
DETAILS...
MODELS/PATTERN...
00Z GUIDANCE IS IN FAIRLY GOOD AGREEMENT FOR THE FORECAST. SO HAVE
MODERATE TO HIGH CONFIDENCE IN THE FORECAST UP TIL LATE IN THE WORK
WEEK...THEN CONFIDENCE DECREASES AS MODEL SPREAD INCREASES. UPPER
LEVEL TROUGH WILL MOVE THROUGH THE AREA ON MONDAY...WITH THE GFS
BEING MORE AMPLIFIED WHILE THE NAM IS VERY PROGRESSIVE. THE SYSTEM
WILL MOVE OUT OF THE REGION BY LATE TUESDAY ALLOWING FOR HIGH
PRESSURE TO BUILD IN FOR THE MID-WEEK. BULK OF THE FORECAST WAS A
MODEL BLEND...MINUS HPC AS THEY WASHED OUT A LOT OF MESO FEATURES.
MODELS ARE SHOWING A POSSIBLE CUT-OFF LOW DEVELOPING OVER THE UPPER
MISSISSIPPI VALLEY. THE ECMWF HAS BEEN MORE AMPLIFIED WITH THIS LOW
THEN THE GFS. REGARDLESS THE PLACEMENT OF THE LOW WILL HAVE AN BIG
IMPACT ON THE REGIONS WEATHER. KEPT PREV FORECAST FOR THURSDAY
ONWARD WITH A LITTLE BLEND OF THE LATEST ECMWF.
MONDAY NIGHT...HIGH CONFIDENCE.
COLD FRONT WILL PUSH THROUGH THE REGION ON MONDAY NIGHT. COMBINED
WITH A SHORTWAVE FORMING A SURFACE LOW ALONG THE FRONT...EXPECT
SHOWERS TO MOVE ACROSS THE REGION WITH AN ENHANCE AREA OF PRECIP
ACROSS RI AND EASTERN MASS. PWAT VALUES RANGE FROM 1 TO 1.5 INCHES
AND SINCE THE SYSTEM IS MOVING QUICKLY BELIEVE THE THREAT FOR
FLOODING IS MINIMAL. HOWEVER WITHIN STRONGER STORMS THERE MAY BE
POSSIBLE MINOR URBAN FLOODING. FRONT SHOULD MOVE OFFSHORE BY LATE
TUESDAY MORNING.
MID-WEEK...MODERATE CONFIDENCE
A FEW LINGER SHOWERS MAY STILL EXIST ACROSS THE CAPE AND ISLANDS IN
THE MORNING. OTHERWISE EXPECT A DRY ON TUESDAY. BACKSIDE OF THE LOW
WILL BRING SOME CLOUD COVER TO THE REGION...BUT ATMOSPHERE IS TO DRY
FOR PRECIP TO FORM. BEHIND THE FRONT ON TUESDAY...WINDS WILL SWITCH
TO THE WEST AND GUST DURING THE DAY. BELIEVE MODELS ARE STILL
UNDERESTIMATING THE MIXING POTENTIAL...ESP ACROSS THE WATERS. EXPECT
GUSTS TO BE AROUND 25 MPH DURING THE DAY.
EXPECT UPPER LEVEL RIDGE TO WORK ITS WAY INTO THE AREA BY LATE
TUESDAY AFTERNOON AS HIGH PRESSURE WILL DOMINATE AT THE SURFACE.
TEMPS DURING THIS TIMEFRAME WILL INCREASE SLIGHTLY WITH MAXS ON
TUESDAY IN THE UPPER 50S TO LOW 60S INCREASING TO MID 60S TO UPPER
70S BY THURSDAY. DRY WEATHER SHOULD PREVAIL DURING THE MID-WEEK AS
THERE IS STILL A GOOD AMOUNT OF DRY AIR... ALLOWING FOR PLEASANT
FALL-LIKE WEATHER.
FRIDAY AND BEYOND...LOW CONFIDENCE
HUGE DIFFERENCE IN THE MODELS HAVE LEAD TO LOW CONFIDENCE FOR THE
END OF THE WEEK INTO THE WEEKEND. AS STATED EARLIER CUT-OFF LOW WILL
FORM ACROSS THE UPPER MISSISSIPPI VALLEY. THE 13.00Z ECMWF ONCE THE
FIRST MODEL TO SHOW THIS FEATURE AS THE 13.12Z GFS JUMPED ON BOARD.
CURRENTLY A LARGE PLACEMENT ON THE LOWS LOCATION. TRENDED TOWARDS
THE ECMWF AS WELL AS PREV FORECAST AS THERE IS STILL A LOT OF
UNCERTAINTY.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
OVERVIEW...MODERATE CONFIDENCE.
SHOWERS OVERSPREADING THE REGION EARLY THIS MORNING AND CONDITIONS
WILL LOWER TO MVFR AND POSSBILY IFR... ESPECIALLY N OF THE MASS
PIKE. S OF THE PIKE JUST BRIEF MVFR IS EXPECTED WITH MAINLY VFR
NEAR THE S COAST. CONDITIONS WILL GRADUALLY IMPROVE AND BECOME VFR
IN THE AFTERNOON AS THE SHOWERS LIFT TO THE N. BECOMING WINDY IN
THE COASTAL PLAIN AND S COAST WITH SW WIND GUSTS TO 30 KT TODAY.
CONDITIONS LOWERING TO MVFR/IFR LATER SUN NIGHT AS STRATUS AND
PATCHY FOG DEVELOPS...IMPROVING TO VFR DURING MONDAY BUT AREAS OF
MVFR MAY REDEVELOP IN THE AFTERNOON WITH MORE SHOWERS POSSIBLE.
KBOS TAF...MODERATE CONFIDENCE.
A PERIOD OF MVFR IN SHOWERS IS LIKELY LATER THIS MORNING...THEN
IMPROVING TO VFR THIS AFTERNOON. SW GUSTS TO 25 KT LIKELY TODAY.
STRATUS MAY DEVELOP LATE TONIGHT.
KBDL TAF...MODERATE CONFIDENCE.
BRIEF PERIOD OF MVFR AND A FEW SHOWERS POSSIBLE THIS
MORNING...OTHERWISE MAINLY VFR. SW GUSTS TO 20-25 KT DEVELOPING.
MVFR/IFR STRATUS MAY DEVELOP LATE TONIGHT.
OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...
MONDAY NIGHT...
MODERATE CONFIDENCE IN VFR WITH MVFR IN HEAVIER SHOWERS...ESP ACROSS
RI AND EASTERN MASS. SHOULD IMPROVE WEST TO EAST BY EARLY TUESDAY
MORNING.
TUESDAY TROUGH THURSDAY...
HIGH CONFIDENCE IN VFR CONDITIONS THROUGH THURSDAY AS HIGH PRESSURE
WILL PREVAIL.
&&
.MARINE...
SHORT TERM...HIGH CONFIDENCE.
LOW LEVEL JET WILL SUPPORT SW WIND GUSTS TO 30 KT TODAY ACROSS THE
WATERS AS THERE IS DECENT LOW LEVEL MIXING. A FEW GALE FORCE GUSTS
TO 35 KT ARE POSSIBLE...ESPECIALLY OVER S COASTAL WATERS BUT HELD
OFF ON GALE WARNING FOR NOW AS WE DONT THINK IT WILL BE
WIDESPREAD. WINDS DIMINISH SLIGHTLY TONIGHT BUT SCA GUSTS TO 25
KT WILL LIKELY CONTINUE INTO MONDAY.
OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...
MODERATE CONFIDENCE.
COLD FRONT WILL MOVE THROUGH MONDAY NIGHT INTO EARLY TUESDAY MORNING
KEEPING OUTER WATER SEAS UP IN SCA CRITERIA. EXPECT WESTERLY WINDS
BEHIND THE FRONT TO GUST UP TO 25-30KTS DURING THE DAY ON TUESDAY. HIGH
PRESSURE WILL BUILD ACROSS THE WATERS LATE TUESDAY LASTING INTO
THURSDAY. STRONG SOUTHERN SWELL FROM RAFAEL MAY REACH THE WATERS BY
LATE WEDNESDAY INCREASING SEAS TO 6 TO 8 FT. EXPECT CONDITIONS TO
SLOWLY RELAX BY LATE THURSDAY.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT MONDAY FOR ANZ232>235-237-
250-254>256.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ230.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT MONDAY FOR ANZ231-251.
SMALL CRAFT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR ANZ236.
&&
$$
SYNOPSIS...KJC/DUNTEN
NEAR TERM...KJC/DUNTEN
SHORT TERM...KJC
LONG TERM...DUNTEN
AVIATION...KJC/DUNTEN
MARINE...KJC/DUNTEN
AREA FORECAST DISCUSSION
NWS MIAMI FL
735 AM EDT SUN OCT 14 2012
.AVIATION...
STRONG NORTHEAST FLOW ACROSS THE ATLANTIC WILL CONTINUE
THIS MORNING INTO THIS AFTERNOON. STRATOCUMULUS IN THE 3 KFT TO 6
KFT RANGE WITH EMBEDDED SHOWERS WILL CONTINUE TO STREAM SOUTHWEST
ACROSS THE ATLANTIC WATERS THIS MORNING WITH THE EAST COAST TAF
SITES EXPERIENCING BRIEF PASSING SHOWERS FROM TIME TO TIME. BY THE
AFTERNOON SCATTERED SHOWERS ARE POSSIBLE WITH A SLIGHT CHANCE OF
THUNDERSTORMS BUT CONFIDENCE IS LOW WITH THE THUNDERSTORMS WITH
VCSH ASSIGNED TO ALL TERMINALS. THE STRONG NORTHEAST WINDS ARE
EXPECTED TO START DECREASING SLOWLY AROUND 00Z THIS EVENING.
&&
.PREV DISCUSSION... /ISSUED 415 AM EDT SUN OCT 14 2012/
..HIGH RISK OF RIP CURRENTS ATLANTIC BEACHES/MINOR COASTAL
FLOODING POSSIBLE BEFORE WINDS RELAX THROUGHOUT THE DAY...
DISCUSSION...THE PWAT ON THE MIAMI EVENING SOUNDING YESTERDAY WAS
ONLY 1.12 INCHES, BUT IT IS PROGGED TO INCREASE INTO THE 1.4-1.6
RANGE THIS AFTERNOON THROUGH MONDAY, BEFORE DRIER AIR INFILTRATES
SOUTH FL BEHIND A WEAK COLD FRONT MON NIGHT. THE RESULT IS THE
EXPECTATION OF SCATTERED SHOWERS, AND POSSIBLY A TSTORM OR TWO,
TODAY-MONDAY WITH THE FOCUS ALONG THE ATLANTIC COAST. THEN, AS A
DRIER AIRMASS ADVECTS INTO THE AREA MON NIGHT-TUE, LITTLE SHOWER
ACTIVITY IS EXPECTED. HOWEVER, WILL PLACE SLIGHT CHANCE EASTERN
HALF OF THE AREA AS THERE COULD BE JUST ENOUGH LOW LEVEL MOISTURE
TO SQUEEZE OUT A FEW SHOWERS ON A QUICK RETURN TO NE-E FLOW BEHIND
THE WEAK FRONTAL BOUNDARY...AS PER GFS/ECMWF MODEL LOW QPF FIELDS.
INSTABILITY INCREASES JUST SLIGHTLY TODAY-MON BUT STILL WEAK LAPSE
RATES. HOWEVER, CANNOT RULE OUT A TSTORM...AND HRRR SHOWS A COUPLE
OF ECHO TOPS TO 40KFT OVER THE SOUTHERN ATLANTIC AND SOUTHERN
INTERIOR OF SOUTH FL THIS AFTERNOON...SO WILL INCLUDE SLIGHT
CHANCE OF TSTORMS TODAY AND MONDAY.
A HIGH RISK OF RIP CURRENTS CONTINUES ALONG THE ATLANTIC BEACHES
TODAY. WINDS WILL GRADUALLY SUBSIDE, BUT THE HIGH RISK WILL PERSIST
THROUGH THE EVENING. MINOR COASTAL FLOODING WILL BE POSSIBLE,
ESPECIALLY AROUND HIGH TIDE AT AROUND SUNRISE THIS MORNING DUE TO
TIDES RUNNING ABOUT A HALF A FOOT ABOVE PREDICTED DUE TO THE STRONG
ONSHORE FLOW. SO WILL CONTINUE TO ADVERTISE THIS POTENTIAL.
SUBSIDING ONSHORE WINDS ALONG THE ATLANTIC COAST SHOULD SLIGHTLY
REDUCE THIS POTENTIAL INTO THE EARLY WORK WEEK, DESPITE TIDES
REMAINING HIGH DUE TO THE SPRING TIDE.
AGAIN, BEHIND THE FRONTAL PASSAGE MON NIGHT, A DRIER AIRMASS WILL
MOVE IN WITH RE-ENFORCING LOWER DEWPOINTS IN THE 60S AND JUST SLIGHT
RAIN CHANCES. A FEW SHOWERS WILL CONTINUE POSSIBLE ESPECIALLY
INTERIOR/EAST COAST THROUGH LATE WEEK. THEN ANOTHER STRONGER COLD
FRONT APPROACHES NEXT WEEKEND...AND MAY MOVE THROUGH, ALTHOUGH THE
LATEST GFS/ECMWF SHOW MUCH OF THE ENERGY NORTH OF OUR AREA. IN
OTHER WORDS, THEY`VE TRENDED LESS AGGRESSIVE WITH THE
FRONT, ESPECIALLY THE ECMWF MODEL. STILL, THERE LOOKS TO BE
ANOTHER COLD FRONTAL PASSAGE SOMETIME THIS WEEKEND. GIVEN TIMING
UNCERTAINTIES, MAINTAINED SLIGHT CHANCE OF SHOWERS THROUGH NEXT
WEEKEND. THE ECMWF SHOWS THE CLOSED MID/UPPER LOW A BIT FURTHER
SOUTH, PULLING UP HIGHER MOISTURE AND EVEN A POTENTIAL FOR TSTORMS
AHEAD/ALONG THE FRONT SATURDAY. WE CAN WATCH MODEL TRENDS. A LOT
OF UNCERTAINTY THIS FAR OUT.
MARINE...WILL CONTINUE THE SMALL CRAFT ADVISORY FOR THE OFFSHORE
GULF WATERS AND BISCAYNE BAY THIS MORNING, BUT DROPPED THE LAKE AS
OBS ARE BELOW 20 KT. THE SCA WILL CONTINUE FOR THE ATLANTIC TODAY,
AND THE PALM BEACH WATERS THROUGH 6Z TONIGHT DUE TO SEAS OF 7 FT
THROUGH THEN BEFORE SUBSIDING FURTHER AS WINDS CONTINUE TO RELAX
THROUGH THE DAY AND BEYOND.
FIRE WEATHER...NO CONCERNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 87 76 88 73 / 40 30 30 10
FORT LAUDERDALE 88 79 88 75 / 40 30 30 10
MIAMI 88 78 88 75 / 40 30 30 10
NAPLES 91 73 89 72 / 30 10 20 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH THIS EVENING FOR COASTAL BROWARD-
COASTAL MIAMI DADE-COASTAL PALM BEACH.
AM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR COASTAL
WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL OUT 20 NM-
WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL EXTENDING
FROM 20 NM TO THE TERRITORIAL WATERS OF THE BAHAMAS.
SMALL CRAFT ADVISORY UNTIL 2 AM EDT MONDAY FOR COASTAL WATERS
FROM JUPITER INLET TO DEERFIELD BEACH, FL OUT 20 NM-WATERS
FROM JUPITER INLET TO DEERFIELD BEACH, FL EXTENDING FROM 20
NM TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR BISCAYNE
BAY.
GM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR GULF
WATERS FROM CHOKOLOSKEE TO BONITA BEACH, FL EXTENDING FROM
20 TO 60 NM.
&&
$$
DISCUSSION/MARINE/FIRE...57/DG
AVIATION/RADAR...60/BD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1018 AM EDT SUN OCT 14 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 325 AM EDT SUN OCT 14 2012
LOW PRESSURE CENTERED OUT IN THE PLAINS WILL CONTINUE TO MOVE
TOWARDS THE GREAT LAKES REGION FOR THE END OF THE WEEKEND. A STRONG
COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL CROSS CENTRAL INDIANA
TODAY BRINGING THE CHANCE FOR SHOWERS AND THUNDERSTORMS TO THE
AREA...WITH THE POSSIBILITY OF STRONG TO SEVERE STORMS.
ADDITIONALLY...STRONG SOUTHERLY WINDS WITH GUSTS OVER 40 MPH ARE
POSSIBLE THIS AFTERNOON AS THE LOW CONTINUES TO STRENGTHEN.
HIGH PRESSURE WILL RETURN TO THE AREA ON MONDAY WITH DRY CONDITIONS
EXPECTED TO CONTINUE FOR ROUGHLY THE FIRST HALF OF THE WORK WEEK.
ANOTHER SYSTEM IS EXPECTED TO IMPACT THE REGION MIDWEEK BRINGING
ADDITIONAL CHANCES FOR PRECIPITATION HEADING INTO NEXT WEEKEND.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 945 AM EDT SUN OCT 14 2012
UPDATED FORECAST BASED ON LATEST RADAR TRENDS. DOWNPLAYED CHANCES
FOR THUNDER UNTIL THIS AFTERNOON AND LOWERED POPS THIS MORNING
ACROSS THE NORTHWEST. ALSO UPDATED PRODUCTS TO REFLECT EXPANSION OF
SLIGHT RISK TO THE ENTIRE FORECAST AREA BY SPC. WILL HAVE TO WATCH
CLEAR SLOT DEVELOPING ACROSS MISSOURI FOR IMPACTS ON CONVECTIVE
DEVELOPMENT AND ON SKY/TEMPERATURES.
PREVIOUS DISCUSSION FOLLOWS...
FORECAST CONCERNS FOR THE NEAR TERM CONTINUE TO BE THE STRONG WINDS
EXPECTED THIS AFTERNOON AS WELL AS THE POTENTIAL FOR SEVERE STORMS
AS A COLD FRONT PASSES THROUGH THE AREA.
WINDS ARE NOT AS STRONG THIS MORNING AS PREVIOUSLY FORECAST WITH THE
PRESSURE GRADIENT TAKING A BIT LONGER TO TIGHTEN UP AS THE LOW IS
SLOWER TO DEEPEN THAN EXPECTED. CURRENT THINKING IS THAT THE HIGHEST
SUSTAINED SPEEDS (20-25 MPH) AND ASSOCIATED GUSTS (40-45 MPH) WILL
NOT MIX DOWN UNTIL CLOSER TO 15Z...RATHER THAN AS EARLY AS 12Z.
THEREFORE...WILL DELAY THE START OF THE WIND ADVISORY TO 15Z. EVEN
WITH THE GRADIENT STAYING FAIRLY STRONG SUNDAY EVENING...WINDS
SHOULD BE ABLE TO SUBSIDE ENOUGH AFTER SUNSET SO AN END TIME OF
00Z MONDAY STILL SEEMS REASONABLE.
LATEST RADAR MOSAIC DISPLAYS A FAIRLY LARGE AREA OF PREFRONTAL
PRECIPITATION ACROSS NORTHERN AND WESTERN ILLINOIS SLIDING INTO
NORTHWEST INDIANA. THE HRRR SUGGESTS THIS SHOULD HOLD TOGETHER BUT
STAY JUST NORTH AND WEST OF THE FORECAST AREA. THIS MAKES SENSE DUE
TO THE LOCATION OF THE LEFT EXIT REGION OF THE 50-60 KT 850 MB JET.
THEREFORE...HAVE TRIMMED BACK POPS FOR THE MORNING HOURS..ESPECIALLY
ACROSS THE EASTERN ZONES.
MODELS DISPLAY SOME VARIABILITY IN TIMING THE ARRIVAL OF THE COLD
FRONT AND ITS ASSOCIATED PRECIPITATION. THE NAM AND ECMWF APPEAR TO
BE THE FASTEST WITH QPF ENCOMPASSING A MAJORITY OF THE FORECAST AREA
BY 12Z WHILE THE GFS APPEARS TO BE MORE IN LINE WITH THE HRRR.
REGARDLESS...ALL MODELS DEPICT THE BULK OF THE PRECIPITATION
IMPACTING THE AREA IN THE 18-00Z TIME FRAME SO HAVE HIT POPS THE
HARDEST DURING THE LATE AFTERNOON AND EARLY EVENING HOURS.
IN REGARDS TO SEVERE POTENTIAL...INSTABILITY LOOKS TO BE RESPECTABLE
WITH AROUND 500-750 J/KG TO WORK WITH BY MID TO LATE AFTERNOON.
HOWEVER...THE DYNAMICS APPEAR TO PROVIDE QUITE A BIT MORE SUPPORT
WITH THE FORCING FROM THE COLD FRONT BEING SUPPORTED BY THE UPPER
WAVE. WITH THE GFS DEPICTING 925 MB WINDS APPROACHING 60 KTS...ANY
DECENT STORMS THAT GET GOING SHOULD NOT HAVE TOO HARD OF A TIME
BRINGING SOME OF THAT DOWN TO THE SURFACE. THEREFORE...CONTINUE TO
EXPECT DAMAGING WINDS TO BE THE MAIN THREAT BUT THE POSSIBILITY FOR
SOME LARGE HAIL AND AN ISOLATED TORNADO OR TWO ARE NOT OUT OF THE
QUESTION.
WITH THE INFLUX OF WARM AND MOIST AIR CONTINUING AS SOUTHERLY WINDS
INCREASE...HIGH TEMPERATURES LOOK TO BE SIMILAR TO SATURDAY...IF NOT
A DEGREE OR TWO HIGHER...RANGING FROM THE LOW 70S ACROSS THE NORTH
TO THE MID 70S IN THE SOUTH.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ISSUED AT 325 AM EDT SUN OCT 14 2012
WITH THE UPPER WAVE SLOW TO MOVE OUT OF THE REGION...HAVE HUNG ON TO
SMALL POPS FOR SUNDAY EVENING TO ACCOUNT FOR ANY LINGERING SHOWERS
OR THUNDERSTORMS. HIGH PRESSURE WILL THEN BUILD INTO THE REGION FOR
THE BEGINNING OF THE WORK WEEK ALLOWING DRY CONDITIONS TO RETURN FOR
THE REMAINDER OF THE PERIOD.
NORTHWEST WINDS FOLLOWING FRONTAL PASSAGE WILL ALLOW TEMPERATURES TO
DROP A BIT BUT HIGHS SHOULD BE NEAR NORMAL VALUES (MID 60S) WITH A
FAIR AMOUNT OF SUNSHINE ON BOTH MONDAY AND TUESDAY. LOW TEMPERATURES
LOOK TO REMAIN MILD (UPPER 40S TO LOW 50S) EXCEPT FOR MONDAY NIGHT
WITH THE CENTER OF THE HIGH RIGHT OVER THE AREA WHEN TEMPERATURES
COULD FALL TO AROUND 40 DEGREES.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 325 AM EDT SUN OCT 14 2012
UNSETTLED WEATHER WILL BE THE RULE...ESPECIALLY EARLY ON. A STRONG
UPPER LOW WILL MOVE INTO THE NORTHERN PLAINS WEDNESDAY AND THEN
TRACK INTO OUR REGION TOWARDS THE WEEKEND WITH SOME MODELS MOVING IT
ON TO THE EAST OVER THE WEEKEND. MODELS INDICATE A STRONG COLD
FRONT WILL MOVE ACROSS OUR REGION LATE WEDNESDAY NIGHT OR EARLY
THURSDAY. ON WEDNESDAY WE CAN EXPECT INCREASING CLOUDS WITH A CHANCE
OF PRECIP LATE ACROSS OUR NORTHWEST HALF. RAISED ALL BLEND
TEMPERATURES SLIGHTLY AS WARM ADVECTION WILL BE OCCURRING AHEAD OF
FRONT AND MEX NUMBERS WERE RUNNING ABOUT 5 DEGREES WARMER.
WILL CONTINUE LIKELY POPS MOST AREAS WEDNESDAY NIGHT AS FRONT MOVES
THROUGH AND THEN THERE IS SOME QUESTION ON THURSDAY AS A DRY SLOT
PUSHES INTO OUR WEST. FOR NOW WILL ACCEPT ALL BLEND POPS WHICH HAS
SLIGHT CHANCE POPS ACROSS OUR WEST AND CHANCE POPS FATHER EAST.
WILL CONTINUE LOW POPS MOST AREAS REST OF FORECAST AS UPPER LOW
ROTATES INTO OUR REGION. BY DAY 7 GFS HAS IT WELL TO OUR EAST WHILE
NEW EURO STILL HAS IT ACROSS OUR REGION. EXCEPT FOR RAISING MINS A
LITTLE THURSDAY NIGHT AND FRIDAY NIGHT WITH CLOUDS...DID NOT MAKE
ANY SIGNIFICANT CHANGE TO ALL BLEND TEMPERATURES FOR THE REST OF THE
EXTENDED.
&&
.AVIATION /DISCUSSION FOR THE 141200Z TAF ISSUANCE/...
ISSUED AT 1015 AM EDT SUN OCT 14 2012
1430Z UPDATE...ONLY ADJUSTMENT MADE TO TAFS FOR THE NEXT FEW HOURS
WAS TO REMOVE MENTION OF VCTS. OTHERWISE NO OTHER CHANGES WERE
MADE AT THIS TIME. PREVIOUS DISCUSSION FOLLOWS...
MAIN ISSUES WILL BE NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS
TODAY AND STRONG WINDS WITH GUSTS TO 35 KNOTS LATER TODAY AS
PRESSURE GRADIENT BECOMES A LITTLE TIGHTER. A STRONG LOW PRESSURE
SYSTEM WILL TRACK TO NORTHERN LOWER MICHIGAN AND A COLD FRONT WILL
MOVE QUICKLY ACROSS OUR REGION BY LATE AFTERNOON. THE LOW PRESSURE
SYSTEM WILL MOVE TO EASTERN LAKE HURON BY LATE TONIGHT AND THE
PRESSURE GRADIENT AND WINDS WILL MODERATE SOME OVERNIGHT.
RADAR SHOWS NUMEROUS SHOWERS AND A FEW THUNDERSTORMS FROM THE
INDIANA ILLINOIS BORDER ON WEST AND THESE WILL SPREAD RAPIDLY EAST
ACROSS TAF SITES NEXT FEW HOURS. SINCE NOT MUCH LIGHTNING PRESENTLY
OCCURRING WILL START TAFS OUT WITH SHOWERS AND MENTION VCTS. RAPID
REFRESH INDICATES A BETTER CHANCE OF THUNDERSTORMS OCCURRING BY
MIDDAY WITH SOME DAYTIME HEATING AND BETTER MIXING WILL CAUSE WIND
GUSTS TO INCREASE TO 35 TO 40 KNOTS. WILL PLAY UP THUNDERSTORMS A
LITTLE MORE THIS PERIOD.
AFTER COLD FRONT MOVES THROUGH SHOWERS AND THUNDERSTORMS WILL
DIMINISH BY LATE AFTERNOON...BUT A FEW SHOWERS WILL LINGER INTO THE
EVENING HOURS. WINDS WILL GRADUALLY DIMINISH THIS EVENING DROPPING
TO 10 TO 15 KNOTS MOST AREAS BY MIDNIGHT.
EXPECT CEILINGS TO AVERAGE AROUND 3 THOUSAND MUCH OF THE
PERIOD...BUT COULD AT TIMES DROP TO LESS THAN 2 THOUSAND FEET IN
SHOWERS AND THUNDERSTORMS LATER TODAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR INZ021-028>031-
035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...HOMANN
NEAR TERM...HOMANN/50
SHORT TERM...HOMANN
LONG TERM....JEH
AVIATION...SMF
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
945 AM EDT SUN OCT 14 2012
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 325 AM EDT SUN OCT 14 2012
LOW PRESSURE CENTERED OUT IN THE PLAINS WILL CONTINUE TO MOVE
TOWARDS THE GREAT LAKES REGION FOR THE END OF THE WEEKEND. A STRONG
COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL CROSS CENTRAL INDIANA
TODAY BRINGING THE CHANCE FOR SHOWERS AND THUNDERSTORMS TO THE
AREA...WITH THE POSSIBILITY OF STRONG TO SEVERE STORMS.
ADDITIONALLY...STRONG SOUTHERLY WINDS WITH GUSTS OVER 40 MPH ARE
POSSIBLE THIS AFTERNOON AS THE LOW CONTINUES TO STRENGTHEN.
HIGH PRESSURE WILL RETURN TO THE AREA ON MONDAY WITH DRY CONDITIONS
EXPECTED TO CONTINUE FOR ROUGHLY THE FIRST HALF OF THE WORK WEEK.
ANOTHER SYSTEM IS EXPECTED TO IMPACT THE REGION MIDWEEK BRINGING
ADDITIONAL CHANCES FOR PRECIPITATION HEADING INTO NEXT WEEKEND.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 945 AM EDT SUN OCT 14 2012
UPDATED FORECAST BASED ON LATEST RADAR TRENDS. DOWNPLAYED CHANCES
FOR THUNDER UNTIL THIS AFTERNOON AND LOWERED POPS THIS MORNING
ACROSS THE NORTHWEST. ALSO UPDATED PRODUCTS TO REFLECT EXPANSION OF
SLIGHT RISK TO THE ENTIRE FORECAST AREA BY SPC. WILL HAVE TO WATCH
CLEAR SLOT DEVELOPING ACROSS MISSOURI FOR IMPACTS ON CONVECTIVE
DEVELOPMENT AND ON SKY/TEMPERATURES.
PREVIOUS DISCUSSION FOLLOWS...
FORECAST CONCERNS FOR THE NEAR TERM CONTINUE TO BE THE STRONG WINDS
EXPECTED THIS AFTERNOON AS WELL AS THE POTENTIAL FOR SEVERE STORMS
AS A COLD FRONT PASSES THROUGH THE AREA.
WINDS ARE NOT AS STRONG THIS MORNING AS PREVIOUSLY FORECAST WITH THE
PRESSURE GRADIENT TAKING A BIT LONGER TO TIGHTEN UP AS THE LOW IS
SLOWER TO DEEPEN THAN EXPECTED. CURRENT THINKING IS THAT THE HIGHEST
SUSTAINED SPEEDS (20-25 MPH) AND ASSOCIATED GUSTS (40-45 MPH) WILL
NOT MIX DOWN UNTIL CLOSER TO 15Z...RATHER THAN AS EARLY AS 12Z.
THEREFORE...WILL DELAY THE START OF THE WIND ADVISORY TO 15Z. EVEN
WITH THE GRADIENT STAYING FAIRLY STRONG SUNDAY EVENING...WINDS
SHOULD BE ABLE TO SUBSIDE ENOUGH AFTER SUNSET SO AN END TIME OF
00Z MONDAY STILL SEEMS REASONABLE.
LATEST RADAR MOSAIC DISPLAYS A FAIRLY LARGE AREA OF PREFRONTAL
PRECIPITATION ACROSS NORTHERN AND WESTERN ILLINOIS SLIDING INTO
NORTHWEST INDIANA. THE HRRR SUGGESTS THIS SHOULD HOLD TOGETHER BUT
STAY JUST NORTH AND WEST OF THE FORECAST AREA. THIS MAKES SENSE DUE
TO THE LOCATION OF THE LEFT EXIT REGION OF THE 50-60 KT 850 MB JET.
THEREFORE...HAVE TRIMMED BACK POPS FOR THE MORNING HOURS..ESPECIALLY
ACROSS THE EASTERN ZONES.
MODELS DISPLAY SOME VARIABILITY IN TIMING THE ARRIVAL OF THE COLD
FRONT AND ITS ASSOCIATED PRECIPITATION. THE NAM AND ECMWF APPEAR TO
BE THE FASTEST WITH QPF ENCOMPASSING A MAJORITY OF THE FORECAST AREA
BY 12Z WHILE THE GFS APPEARS TO BE MORE IN LINE WITH THE HRRR.
REGARDLESS...ALL MODELS DEPICT THE BULK OF THE PRECIPITATION
IMPACTING THE AREA IN THE 18-00Z TIME FRAME SO HAVE HIT POPS THE
HARDEST DURING THE LATE AFTERNOON AND EARLY EVENING HOURS.
IN REGARDS TO SEVERE POTENTIAL...INSTABILITY LOOKS TO BE RESPECTABLE
WITH AROUND 500-750 J/KG TO WORK WITH BY MID TO LATE AFTERNOON.
HOWEVER...THE DYNAMICS APPEAR TO PROVIDE QUITE A BIT MORE SUPPORT
WITH THE FORCING FROM THE COLD FRONT BEING SUPPORTED BY THE UPPER
WAVE. WITH THE GFS DEPICTING 925 MB WINDS APPROACHING 60 KTS...ANY
DECENT STORMS THAT GET GOING SHOULD NOT HAVE TOO HARD OF A TIME
BRINGING SOME OF THAT DOWN TO THE SURFACE. THEREFORE...CONTINUE TO
EXPECT DAMAGING WINDS TO BE THE MAIN THREAT BUT THE POSSIBILITY FOR
SOME LARGE HAIL AND AN ISOLATED TORNADO OR TWO ARE NOT OUT OF THE
QUESTION.
WITH THE INFLUX OF WARM AND MOIST AIR CONTINUING AS SOUTHERLY WINDS
INCREASE...HIGH TEMPERATURES LOOK TO BE SIMILAR TO SATURDAY...IF NOT
A DEGREE OR TWO HIGHER...RANGING FROM THE LOW 70S ACROSS THE NORTH
TO THE MID 70S IN THE SOUTH.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ISSUED AT 325 AM EDT SUN OCT 14 2012
WITH THE UPPER WAVE SLOW TO MOVE OUT OF THE REGION...HAVE HUNG ON TO
SMALL POPS FOR SUNDAY EVENING TO ACCOUNT FOR ANY LINGERING SHOWERS
OR THUNDERSTORMS. HIGH PRESSURE WILL THEN BUILD INTO THE REGION FOR
THE BEGINNING OF THE WORK WEEK ALLOWING DRY CONDITIONS TO RETURN FOR
THE REMAINDER OF THE PERIOD.
NORTHWEST WINDS FOLLOWING FRONTAL PASSAGE WILL ALLOW TEMPERATURES TO
DROP A BIT BUT HIGHS SHOULD BE NEAR NORMAL VALUES (MID 60S) WITH A
FAIR AMOUNT OF SUNSHINE ON BOTH MONDAY AND TUESDAY. LOW TEMPERATURES
LOOK TO REMAIN MILD (UPPER 40S TO LOW 50S) EXCEPT FOR MONDAY NIGHT
WITH THE CENTER OF THE HIGH RIGHT OVER THE AREA WHEN TEMPERATURES
COULD FALL TO AROUND 40 DEGREES.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 325 AM EDT SUN OCT 14 2012
UNSETTLED WEATHER WILL BE THE RULE...ESPECIALLY EARLY ON. A STRONG
UPPER LOW WILL MOVE INTO THE NORTHERN PLAINS WEDNESDAY AND THEN
TRACK INTO OUR REGION TOWARDS THE WEEKEND WITH SOME MODELS MOVING IT
ON TO THE EAST OVER THE WEEKEND. MODELS INDICATE A STRONG COLD
FRONT WILL MOVE ACROSS OUR REGION LATE WEDNESDAY NIGHT OR EARLY
THURSDAY. ON WEDNESDAY WE CAN EXPECT INCREASING CLOUDS WITH A CHANCE
OF PRECIP LATE ACROSS OUR NORTHWEST HALF. RAISED ALL BLEND
TEMPERATURES SLIGHTLY AS WARM ADVECTION WILL BE OCCURRING AHEAD OF
FRONT AND MEX NUMBERS WERE RUNNING ABOUT 5 DEGREES WARMER.
WILL CONTINUE LIKELY POPS MOST AREAS WEDNESDAY NIGHT AS FRONT MOVES
THROUGH AND THEN THERE IS SOME QUESTION ON THURSDAY AS A DRY SLOT
PUSHES INTO OUR WEST. FOR NOW WILL ACCEPT ALL BLEND POPS WHICH HAS
SLIGHT CHANCE POPS ACROSS OUR WEST AND CHANCE POPS FATHER EAST.
WILL CONTINUE LOW POPS MOST AREAS REST OF FORECAST AS UPPER LOW
ROTATES INTO OUR REGION. BY DAY 7 GFS HAS IT WELL TO OUR EAST WHILE
NEW EURO STILL HAS IT ACROSS OUR REGION. EXCEPT FOR RAISING MINS A
LITTLE THURSDAY NIGHT AND FRIDAY NIGHT WITH CLOUDS...DID NOT MAKE
ANY SIGNIFICANT CHANGE TO ALL BLEND TEMPERATURES FOR THE REST OF THE
EXTENDED.
&&
.AVIATION /DISCUSSION FOR THE 141200Z TAF ISSUANCE/...
ISSUED AT 650 AM EDT SUN OCT 14 2012
MAIN ISSUES WILL BE NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS
TODAY AND STRONG WINDS WITH GUSTS TO 35 KNOTS LATER TODAY AS
PRESSURE GRADIENT BECOMES A LITTLE TIGHTER. A STRONG LOW PRESSURE
SYSTEM WILL TRACK TO NORTHERN LOWER MICHIGAN AND A COLD FRONT WILL
MOVE QUICKLY ACROSS OUR REGION BY LATE AFTERNOON. THE LOW PRESSURE
SYSTEM WILL MOVE TO EASTERN LAKE HURON BY LATE TONIGHT AND THE
PRESSURE GRADIENT AND WINDS WILL MODERATE SOME OVERNIGHT.
RADAR SHOWS NUMEROUS SHOWERS AND A FEW THUNDERSTORMS FROM THE
INDIANA ILLINOIS BORDER ON WEST AND THESE WILL SPREAD RAPIDLY EAST
ACROSS TAF SITES NEXT FEW HOURS. SINCE NOT MUCH LIGHTNING PRESENTLY
OCCURRING WILL START TAFS OUT WITH SHOWERS AND MENTION VCTS. RAPID
REFRESH INDICATES A BETTER CHANCE OF THUNDERSTORMS OCCURRING BY
MIDDAY WITH SOME DAYTIME HEATING AND BETTER MIXING WILL CAUSE WIND
GUSTS TO INCREASE TO 35 TO 40 KNOTS. WILL PLAY UP THUNDERSTORMS A
LITTLE MORE THIS PERIOD.
AFTER COLD FRONT MOVES THROUGH SHOWERS AND THUNDERSTORMS WILL
DIMINISH BY LATE AFTERNOON...BUT A FEW SHOWERS WILL LINGER INTO THE
EVENING HOURS. WINDS WILL GRADUALLY DIMINISH THIS EVENING DROPPING
TO 10 TO 15 KNOTS MOST AREAS BY MIDNIGHT.
EXPECT CEILINGS TO AVERAGE AROUND 3 THOUSAND MUCH OF THE
PERIOD...BUT COULD AT TIMES DROP TO LESS THAN 2 THOUSAND FEET IN
SHOWERS AND THUNDERSTORMS LATER TODAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING FOR
INZ021-028>031-035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...HOMANN
NEAR TERM...HOMANN/50
SHORT TERM...HOMANN
LONG TERM....JEH
AVIATION...JEH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
650 AM EDT SUN OCT 14 2012
.UPDATE...
AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 325 AM EDT SUN OCT 14 2012
LOW PRESSURE CENTERED OUT IN THE PLAINS WILL CONTINUE TO MOVE
TOWARDS THE GREAT LAKES REGION FOR THE END OF THE WEEKEND. A STRONG
COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL CROSS CENTRAL INDIANA
TODAY BRINGING THE CHANCE FOR SHOWERS AND THUNDERSTORMS TO THE
AREA...WITH THE POSSIBILITY OF STRONG TO SEVERE STORMS.
ADDITIONALLY...STRONG SOUTHERLY WINDS WITH GUSTS OVER 40 MPH ARE
POSSIBLE THIS AFTERNOON AS THE LOW CONTINUES TO STRENGTHEN.
HIGH PRESSURE WILL RETURN TO THE AREA ON MONDAY WITH DRY CONDITIONS
EXPECTED TO CONTINUE FOR ROUGHLY THE FIRST HALF OF THE WORK WEEK.
ANOTHER SYSTEM IS EXPECTED TO IMPACT THE REGION MIDWEEK BRINGING
ADDITIONAL CHANCES FOR PRECIPITATION HEADING INTO NEXT WEEKEND.
&&
.NEAR TERM /TODAY/...
ISSUED AT 325 AM EDT SUN OCT 14 2012
FORECAST CONCERNS FOR THE NEAR TERM CONTINUE TO BE THE STRONG WINDS
EXPECTED THIS AFTERNOON AS WELL AS THE POTENTIAL FOR SEVERE STORMS
AS A COLD FRONT PASSES THROUGH THE AREA.
WINDS ARE NOT AS STRONG THIS MORNING AS PREVIOUSLY FORECAST WITH THE
PRESSURE GRADIENT TAKING A BIT LONGER TO TIGHTEN UP AS THE LOW IS
SLOWER TO DEEPEN THAN EXPECTED. CURRENT THINKING IS THAT THE HIGHEST
SUSTAINED SPEEDS (20-25 MPH) AND ASSOCIATED GUSTS (40-45 MPH) WILL
NOT MIX DOWN UNTIL CLOSER TO 15Z...RATHER THAN AS EARLY AS 12Z.
THEREFORE...WILL DELAY THE START OF THE WIND ADVISORY TO 15Z. EVEN
WITH THE GRADIENT STAYING FAIRLY STRONG SUNDAY EVENING...WINDS
SHOULD BE ABLE TO SUBSIDE ENOUGH AFTER SUNSET SO AN END TIME OF
00Z MONDAY STILL SEEMS REASONABLE.
LATEST RADAR MOSAIC DISPLAYS A FAIRLY LARGE AREA OF PREFRONTAL
PRECIPITATION ACROSS NORTHERN AND WESTERN ILLINOIS SLIDING INTO
NORTHWEST INDIANA. THE HRRR SUGGESTS THIS SHOULD HOLD TOGETHER BUT
STAY JUST NORTH AND WEST OF THE FORECAST AREA. THIS MAKES SENSE DUE
TO THE LOCATION OF THE LEFT EXIT REGION OF THE 50-60 KT 850 MB JET.
THEREFORE...HAVE TRIMMED BACK POPS FOR THE MORNING HOURS..ESPECIALLY
ACROSS THE EASTERN ZONES.
MODELS DISPLAY SOME VARIABILITY IN TIMING THE ARRIVAL OF THE COLD
FRONT AND ITS ASSOCIATED PRECIPITATION. THE NAM AND ECMWF APPEAR TO
BE THE FASTEST WITH QPF ENCOMPASSING A MAJORITY OF THE FORECAST AREA
BY 12Z WHILE THE GFS APPEARS TO BE MORE IN LINE WITH THE HRRR.
REGARDLESS...ALL MODELS DEPICT THE BULK OF THE PRECIPITATION
IMPACTING THE AREA IN THE 18-00Z TIME FRAME SO HAVE HIT POPS THE
HARDEST DURING THE LATE AFTERNOON AND EARLY EVENING HOURS.
IN REGARDS TO SEVERE POTENTIAL...INSTABILITY LOOKS TO BE RESPECTABLE
WITH AROUND 500-750 J/KG TO WORK WITH BY MID TO LATE AFTERNOON.
HOWEVER...THE DYNAMICS APPEAR TO PROVIDE QUITE A BIT MORE SUPPORT
WITH THE FORCING FROM THE COLD FRONT BEING SUPPORTED BY THE UPPER
WAVE. WITH THE GFS DEPICTING 925 MB WINDS APPROACHING 60 KTS...ANY
DECENT STORMS THAT GET GOING SHOULD NOT HAVE TOO HARD OF A TIME
BRINGING SOME OF THAT DOWN TO THE SURFACE. THEREFORE...CONTINUE TO
EXPECT DAMAGING WINDS TO BE THE MAIN THREAT BUT THE POSSIBILITY FOR
SOME LARGE HAIL AND AN ISOLATED TORNADO OR TWO ARE NOT OUT OF THE
QUESTION.
WITH THE INFLUX OF WARM AND MOIST AIR CONTINUING AS SOUTHERLY WINDS
INCREASE...HIGH TEMPERATURES LOOK TO BE SIMILAR TO SATURDAY...IF NOT
A DEGREE OR TWO HIGHER...RANGING FROM THE LOW 70S ACROSS THE NORTH
TO THE MID 70S IN THE SOUTH.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ISSUED AT 325 AM EDT SUN OCT 14 2012
WITH THE UPPER WAVE SLOW TO MOVE OUT OF THE REGION...HAVE HUNG ON TO
SMALL POPS FOR SUNDAY EVENING TO ACCOUNT FOR ANY LINGERING SHOWERS
OR THUNDERSTORMS. HIGH PRESSURE WILL THEN BUILD INTO THE REGION FOR
THE BEGINNING OF THE WORK WEEK ALLOWING DRY CONDITIONS TO RETURN FOR
THE REMAINDER OF THE PERIOD.
NORTHWEST WINDS FOLLOWING FRONTAL PASSAGE WILL ALLOW TEMPERATURES TO
DROP A BIT BUT HIGHS SHOULD BE NEAR NORMAL VALUES (MID 60S) WITH A
FAIR AMOUNT OF SUNSHINE ON BOTH MONDAY AND TUESDAY. LOW TEMPERATURES
LOOK TO REMAIN MILD (UPPER 40S TO LOW 50S) EXCEPT FOR MONDAY NIGHT
WITH THE CENTER OF THE HIGH RIGHT OVER THE AREA WHEN TEMPERATURES
COULD FALL TO AROUND 40 DEGREES.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 325 AM EDT SUN OCT 14 2012
UNSETTLED WEATHER WILL BE THE RULE...ESPECIALLY EARLY ON. A STRONG
UPPER LOW WILL MOVE INTO THE NORTHERN PLAINS WEDNESDAY AND THEN
TRACK INTO OUR REGION TOWARDS THE WEEKEND WITH SOME MODELS MOVING IT
ON TO THE EAST OVER THE WEEKEND. MODELS INDICATE A STRONG COLD
FRONT WILL MOVE ACROSS OUR REGION LATE WEDNESDAY NIGHT OR EARLY
THURSDAY. ON WEDNESDAY WE CAN EXPECT INCREASING CLOUDS WITH A CHANCE
OF PRECIP LATE ACROSS OUR NORTHWEST HALF. RAISED ALL BLEND
TEMPERATURES SLIGHTLY AS WARM ADVECTION WILL BE OCCURRING AHEAD OF
FRONT AND MEX NUMBERS WERE RUNNING ABOUT 5 DEGREES WARMER.
WILL CONTINUE LIKELY POPS MOST AREAS WEDNESDAY NIGHT AS FRONT MOVES
THROUGH AND THEN THERE IS SOME QUESTION ON THURSDAY AS A DRY SLOT
PUSHES INTO OUR WEST. FOR NOW WILL ACCEPT ALL BLEND POPS WHICH HAS
SLIGHT CHANCE POPS ACROSS OUR WEST AND CHANCE POPS FATHER EAST.
WILL CONTINUE LOW POPS MOST AREAS REST OF FORECAST AS UPPER LOW
ROTATES INTO OUR REGION. BY DAY 7 GFS HAS IT WELL TO OUR EAST WHILE
NEW EURO STILL HAS IT ACROSS OUR REGION. EXCEPT FOR RAISING MINS A
LITTLE THURSDAY NIGHT AND FRIDAY NIGHT WITH CLOUDS...DID NOT MAKE
ANY SIGNIFICANT CHANGE TO ALL BLEND TEMPERATURES FOR THE REST OF THE
EXTENDED.
&&
.AVIATION /DISCUSSION FOR THE 141200Z TAF ISSUANCE/...
ISSUED AT 650 AM EDT SUN OCT 14 2012
MAIN ISSUES WILL BE NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS
TODAY AND STRONG WINDS WITH GUSTS TO 35 KNOTS LATER TODAY AS
PRESSURE GRADIENT BECOMES A LITTLE TIGHTER. A STRONG LOW PRESSURE
SYSTEM WILL TRACK TO NORTHERN LOWER MICHIGAN AND A COLD FRONT WILL
MOVE QUICKLY ACROSS OUR REGION BY LATE AFTERNOON. THE LOW PRESSURE
SYSTEM WILL MOVE TO EASTERN LAKE HURON BY LATE TONIGHT AND THE
PRESSURE GRADIENT AND WINDS WILL MODERATE SOME OVERNIGHT.
RADAR SHOWS NUMEROUS SHOWERS AND A FEW THUNDERSTORMS FROM THE
INDIANA ILLINOIS BORDER ON WEST AND THESE WILL SPREAD RAPIDLY EAST
ACROSS TAF SITES NEXT FEW HOURS. SINCE NOT MUCH LIGHTNING PRESENTLY
OCCURRING WILL START TAFS OUT WITH SHOWERS AND MENTION VCTS. RAPID
REFRESH INDICATES A BETTER CHANCE OF THUNDERSTORMS OCCURRING BY
MIDDAY WITH SOME DAYTIME HEATING AND BETTER MIXING WILL CAUSE WIND
GUSTS TO INCREASE TO 35 TO 40 KNOTS. WILL PLAY UP THUNDERSTORMS A
LITTLE MORE THIS PERIOD.
AFTER COLD FRONT MOVES THROUGH SHOWERS AND THUNDERSTORMS WILL
DIMINISH BY LATE AFTERNOON...BUT A FEW SHOWERS WILL LINGER INTO THE
EVENING HOURS. WINDS WILL GRADUALLY DIMINISH THIS EVENING DROPPING
TO 10 TO 15 KNOTS MOST AREAS BY MIDNIGHT.
EXPECT CEILINGS TO AVERAGE AROUND 3 THOUSAND MUCH OF THE
PERIOD...BUT COULD AT TIMES DROP TO LESS THAN 2 THOUSAND FEET IN
SHOWERS AND THUNDERSTORMS LATER TODAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING FOR
INZ021-028>031-035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...HOMANN
NEAR TERM...HOMANN
SHORT TERM...HOMANN
LONG TERM....JEH
AVIATION...JEH
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
747 AM EDT SUN OCT 14 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 610 AM EDT SUN OCT 14 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS CONTINUE TO SHOW A ZONAL FLOW
ACROSS SRN CANADA AND THE FAR NRN CONUS WITH A WELL-DEFINED
SHORTWAVE OVER ERN KS AND WRN MO POISED TO LIFT NE TOWARD THE
CENTRAL GREAT LAKES THIS AFTERNOON. DEFORMATION/FRONTOGENESIS RAIN
BAND IN DEVELOPING BAROCLINIC LEAF/COMMA HEAD OF SHORTWAVE
STRETCHING FROM ERN NEBRASKA AND NRN IA INTO CENTRAL WI LINES UP
NICELY WITH 700 MB FGEN FORCING AS DEPICTED BY 00Z GFS. SO FAR EARLY
THIS MORNING...RADAR SHOW ONLY SPURIOUS SHRA ACTIVITY MOVING ACROSS
SCNTRL AND SE UPR MI IN AREA OF WEAK Q-VECT CONV AND FGEN FORCING.
THERE HAS ALSO BEEN SOME UPSLOPE DZ AT KMQT EARLY THIS MORNING IN
NRLY FLOW.
PCPN TRENDS/COVERAGE WILL BE THE MAIN FCST ISSUES IN THE SHORT TERM.
ZONAL FLOW ACROSS SRN CANADA/FAR NRN CONUS IS EXPECTED TO BUCKLE
TODAY AS HEIGHT RISES OVER WRN NAMERICA FORCE DOWNSTREAM HEIGHT
FALLS INTO MISSISSIPPI VALLEY REGION. THIS WILL HELP EJECT THE
CENTRAL PLAINS SHORTWAVE NE INTO THE GREAT LAKES THIS AFTERNOON.
EXACTLY HOW FAR N THE SHORTWAVE LIFTS ACROSS LOWER MI WILL BE
IMPORTANT TO THE PCPN COVERAGE TODAY. EVEN NOW...SO CLOSE TO THE
ONSET OF THE EVENT...THE MODELS ARE STILL EXHIBITING SIGNIFICANT RUN
TO RUN DIFFERENCES. THE MAJORITY OF THE 00Z RUNS WERE SHOWING THE
MAIN PCPN BAND STAYING MAINLY SOUTH OF THE FCST AREA...BRUSHING THE
FAR SCNTRL AND ERN FCST AREA WITH AROUND A HALF INCH OF RAINFALL
WITH A FAIRLY SHARP CUT-OFF OF PCPN HEADING NORTH AND WEST. NOW THE
06Z NAM AND GFS HAVE TRENDED FARTHER NORTH AND WEST WITH PCPN
SHIELD...STILL DROPPING THE HEAVIEST RAIN OVER THE SCNTRL AND EAST
BUT ALSO BRINGING ANYWHERE FROM 0.25-0.50 INCH INTO DICKINSON AND SE
HALF OF MQT COUNTY.
LATEST RADAR TRENDS AND MODEL FGEN FIELDS SUGGEST A SLIGHT NORTHWARD
TREND IN MAIN PCPN BAND IS POSSIBLE AS SHORTWAVE LIFTS TOWARD REGION
TODAY AND THIS WILL BE SOMETHING TO WATCH AS THE MORNING PROGRESSES.
SHORT TERM FCST UPDATES MAY NEED TO EXPAND CATEGORICAL POPS OVER FAR
SCNTRL AND ERN FCST AREA FARTHER NW TO ACCOUNT FOR THESE PCPN
TRENDS.
TONIGHT...AS SHORTWAVE AND ASSOC SFC LOW LIFT EAST OF THE REGION
LATER TONIGHT...EXPECT PCPN TO TAPER OFF OVER CENTRAL PORTIONS OF
THE CWA THIS EVENING AND OVER ERN PORTIONS OVERNIGHT. WITH MARGINAL
COLD ADVECTION BEHIND THE SYSTEM TONIGHT...AND BUFR SNDGS AND WET
BULB ZERO HGTS NOT REALLY SUPPORTING MUCH IN THE WAY OF PCPN
MIXING/CHANGING TO SNOW LATE TONIGHT...HAVE DECIDED TO PULL MENTION
OF SNOW LATE TONIGHT FOR NCNTRL ZONES. STRONG DEEP CYCLONIC NRLY
FLOW WILL LIKELY SUPPORT SOME LAKE EFFECT UPSLOPE RAIN/DZ THROUGH
MUCH OF NIGHT OVER NCNTRL PORTIONS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 610 AM EDT SUN OCT 14 2012
UPPER LEVEL PATTERN TO BEGIN THE LONG TERM ON MONDAY HAS A TROUGH
FROM HUDSON BAY INTO THE OHIO VALLEY WITH ASSOCIATED SFC LOW LIFTING
INTO SOUTHERN QUEBEC. KEPT MENTION OF LIGHT LK EFFECT PRECIP FIRST
THING ON MONDAY MORNING OVER NORTH CENTRAL WITH H85 TEMPS DOWN TO
-3C LEADING TO MARGINAL OVER-WATER INSTABILITY WITH DELTA T/S OVER
15C. SOUNDINGS FOR MQT FROM GFS/NAM INDICATE WBZERO HEIGHTS STAYING
AOA 1000FT AGL SO KEPT PTYPE AS ONLY RAIN. EVEN WITH CYCLONIC
NORTHERLY FLOW IN WAKE OF SFC LOW MOVING INTO QUEBEC...SOUNDINGS
SHOW ONLY A SHALLOW MOIST LAYER AFTER 12Z MONDAY WITH TEMPS IN THE
MOIST LAYER NOT ANY COLDER THAN -5C. SO...MAY JUST END UP WITH
FINE DRIZZLE OR MAYBE JUST A FEW SPRINKLES SINCE SUB CLOUD LAYER IS
INCREASINLY MIXED WITH INVERTED-V LOOK.
SFC RIDGE FOLLOWING IN WAKE OF THE SFC LOW SHOULD BE IN PROCESS OF
WORKING ACROSS UPPER GREAT LAKES BY AFTN WHICH WILL CONK OUT ANY
LINGERING RAIN SHOWERS/DRIZZLE/SPRINKLES. CLOUDS USUALLY TOUGHER TO
GO AND WOULD EXPECT SCT-BKN STRATOCU TO HANG AROUND TIL LATER AFTN
AS H85 RIDGE BEGINS TO MOVE INTO THE AREA.
UPPER FLOW BECOMES MORE WESTERLY INTO TUESDAY ALLOWING WEAK SFC
TROUGH/WARM FRONT TO SKIRT ACROSS NORTHERN ONTARIO AND UPPER GREAT
LAKES. ALTHOUGH SFC REFLECTION IS WEAK...ACTUALLY IS STRONG WARM AIR
ADVECTION ALOFT WITH THE AHEAD AND ALONG SHORTWAVE PASSING OVER THE
REGION. ISENTROPIC ASCENT ON THE 300K SFC /H8-H7/ IMPACTS MOST OF
CWA...BUT STRONGEST H85 TEMP ADVECTION IS MORE OVER THE NORTH CWA.
OVERALL A PERIOD OF MOISTURE/STRONG UVM IN THE H7-H5 LAYER /TEMPS
BLO -10C/ ARE FORECAST WHICH SHOULD IN TURN LEAD TO GREATER CHANCE
OF SEEING SOME RAIN MAKE IT TO SFC DESPITE DRY SUB H85 LAYERS MODELS
SHOW. LOOKS LIKE HIGHER POP/LOW QPF SETUP. INCREASED POPS TO LIKELY
OVER NORTH AND ALSO EAST. HIGH CHANCES SHOULD COVER IT FOR AREAS
FARTHER AWAY FROM MID LEVEL LIFT. MID LEVEL MOISTURE/UVM EXITS TO
THE FAR EAST CWA BY LATE DAY...SO HAVE TRIMMED BACK POPS IN THE WEST
AFTER 18Z AND FOR ALL AREAS ON INTO TUESDAY NIGHT. DESPITE
CLOUDS/SHOWERS...WARMING TEMPS ALOFT AND A SOUTH WIND SHOULD ALLOW
FOR TEMPS TO PUSH ABOVE NORMAL...ESPECIALLY DURING AFTN AS PRECIP
TAPERS OFF. COULD SEE SOME SPOTS ON TUESDAY TOUCH 60 DEGREES IF
ENOUGH THINNING IN OVERCAST OCCURS. BEST SHOT FOR WARMER TEMPS IN
THE WEST AND SOUTHWEST CWA.
ATTENTION TUESDAY NIGHT INTO WEDNESDAY WILL BE ON SHORTWAVE TROUGH
AND STRONG UPPER LEVEL JET DIGGING INTO PACIFIC NORTHWEST.
ASSOCIATED SFC LOW /PRETTY DEEP AT SUB 985MB/ FORMS OVER SOUTHERN
ALBERTA LATER TUESDAY WITH COMPLEX OF LOWS THEN DEVELOPING FROM
SASKATCHEWAN INTO MINNESOTA AND WESTERN WISCONSIN BY LATE DAY ON
WEDNESDAY. SLIGHT POTENTIAL FOR COUPLE BATCHES OF MID LEVEL MOISTURE
LIFTING ACROSS TUESDAY NIGHT TO YIELD SPRINKLES OR A SHOWER ON
TUESDAY NIGHT. FOR MOST PART THOUGH THE NIGHT SHOULD END UP DRY
AND FAIRLY MILD FOR MID-LATE OCTOBER WITH LOWS IN THE MID-UPPER 40S.
NOW SEEMS LIKE WEDNESDAY WILL BE FOR MOST PART FAIRLY VOID OF SIG
PRECIP OVER THE CWA. UPPER TROUGH AND IDEAL JET SUPPORT FOR PRECIP
REMAIN WELL TO WEST OVER MIDDLE MISSISSIPPI RIVER VALLEY. ALSO
SOME INDICATION FROM LATEST ECMWF THAT SHARPER SHORTWAVE EMBEDDED IN
SOUTHERN PORTION OF UPR TROUGH WILL FOCUS SFC LOW FARTHER SOUTH OVER
SOUTHERN IOWA WHICH KEEPS H85 JET AND HIGHER H85 DWPNT LOCKED UP
MORE TO SOUTHWEST OF CWA. KEPT CHANCE POPS OVER WEST AND SOUTHWEST
CWA...BUT DID TRIM TO ONLY SLIGHT CHANCES OVER THE EASTERN CWA.
SIMILAR TO TUESDAY...GIVEN WARM AIR ALOFT /H85 TEMPS PUSHING +10C
OVER SOUTH CWA/ AND SOUTHERLY WINDS...MAX TEMPS COULD PUSH PAST 60
DEGREES AGAIN. TRENDS IN CLOUD COVER WILL HAVE BIG IMPACT ON TEMPS
THOUGH AS IF PARTIAL CLEARING COULD OCCUR OVER CWA...TEMPS MAKING
RUN WELL INTO THE 60S /EVEN AN ISOLD 70 DEGREE READING/ WOULD BE
FEASIBLE.
BEYOND WEDNESDAY MODELS DIVERGE WITH HANDLING OF TROUGH AND SFC
LOW TO CLOSE THE WEEK. GFS BECOMES MORE PROGRESSIVE WITH LOW PUSHING
TOWARD LK MICHIGAN BY THURSDAY AFTERNOON WHILE ECMWF AND GEM-NHEM
SHOW MORE OF A SLOWER UPPER TROUGH PROGRESSION AND KEEP PRIMARY SFC
LOW LUMBERING MORE OVER SOUTHERN PORTION OF MINNESOTA THROUGH
THURSDAY. SFC LOW PLACEMENT PRETTY MUCH ALL OVER THE PLACE IN MORE
RECENT MODEL RUNS. SINCE THE SYSTEM IS VERY WRAPPED UP ON ALL
MODELS...POTENTIAL IS THERE FOR SIGNIFICANT DRY SLOTTING SOMETIME
THURSDAY INTO FRIDAY ALONG WITH MINOR SHORTWAVES ROTATING AROUND
MAIN UPPER LOW. LEANED HEAVILY ON CONSENSUS FOR POPS/SKY/WINDS FOR
THURSDAY AND BEYOND DUE TO LACK OF CONSISTENCY IN ANY OF THE MODELS
AND VARYING SOLUTIONS WITH HANDLING OF UPPER TROUGH/SFC LOW. COULD
EASILY SEE WINDS BEING MUCH STRONGER THAN IS SHOWN WITH THIS
FORECAST...ESPECIALLY THURSDAY AND FRIDAY...BUT AT THIS POINT
CANNOT PIN POINT WHERE THE STRONGER WINDS WILL OCCUR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 740 AM EDT SUN OCT 14 2012
LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE NORTHEAST TOWARD THE
CENTRAL GREAT LAKES DURING THE FCST PERIOD. AT KIWD...IFR WILL
CONTINUE MUCH OF THE FCST PD WITH SOME -DZ DVLPG BY LATE MORNING IN
UPSLOPE NRLY FLOW. AT KCMX...MVFR CONDITIONS SHOULD GENERALLY
PREVAIL THROUGH PD UNDER NRLY FLOW. AT KSAW...LOW MVFR CONDITIONS
WILL FALL BACK TO LIFR CONDITIONS LATER THIS MORNING AS SHOWERS/RAIN
MOVE IN AND UPSLOPE NNE WINDS STRENGTHEN. DRIER AIR LATE TONIGHT IN
NNW SHOULD ALLOW CONDITIONS TO IMPROVE TO MVFR AGAIN.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 610 AM EDT SUN OCT 14 2012
EXPECT N TO NE WINDS TO INCREASE TODAY AS LOW PRES OVER THE CENTRAL
PLAINS LIFTS NE INTO NRN LWR MICHIGAN THIS AFTERNOON. DURING THE
AFTN...WINDS SHOULD BE IN THE 20-30KT RANGE OVER THE CNTRL AND ERN
PORTIONS OF LAKE SUPERIOR. WINDS WILL BE LIGHTER OVER THE FAR W.
EXPECT NORTHERLY GALES TO DEVELOP OVER EASTERN LAKE SUPERIOR THIS
EVENING AND THEN CONTINUE INTO MONDAY MORNING AS THE LOW RAPIDLY
DEEPENS AND MOVES EAST OF THE AREA AND HIGH PRESSURE PUSHES IN FROM
THE WEST. WINDS SETTLE DOWN MONDAY AFTERNOON AND MONDAY NIGHT WITH
ARRIVAL OF HIGH PRESSURE. ANOTHER LOW PRESSURE WILL MOVE INTO THE
UPPER GREAT LAKES ON WEDNESDAY. SOUTH WINDS AHEAD OF THIS LOW COULD
BRIEFLY REACH GALES TO 35 KTS OVER ERN LAKE SUPERIOR TUE AFTERNOON.
OTHERWISE...WINDS IN THE VICINITY OF THE LOW SHOULD REMAIN LESS THAN
20 KTS WEDNESDAY INTO THURSDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 7 PM THIS EVENING TO 10 AM EDT MONDAY FOR
LSZ266-267.
LAKE MICHIGAN...
GALE WARNING FROM 6 PM THIS EVENING TO 11 AM EDT MONDAY FOR
LMZ221-250.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
611 AM EDT SUN OCT 14 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 610 AM EDT SUN OCT 14 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS CONTINUE TO SHOW A ZONAL FLOW
ACROSS SRN CANADA AND THE FAR NRN CONUS WITH A WELL-DEFINED
SHORTWAVE OVER ERN KS AND WRN MO POISED TO LIFT NE TOWARD THE
CENTRAL GREAT LAKES THIS AFTERNOON. DEFORMATION/FRONTOGENESIS RAIN
BAND IN DEVELOPING BAROCLINIC LEAF/COMMA HEAD OF SHORTWAVE
STRETCHING FROM ERN NEBRASKA AND NRN IA INTO CENTRAL WI LINES UP
NICELY WITH 700 MB FGEN FORCING AS DEPICTED BY 00Z GFS. SO FAR EARLY
THIS MORNING...RADAR SHOW ONLY SPURIOUS SHRA ACTIVITY MOVING ACROSS
SCNTRL AND SE UPR MI IN AREA OF WEAK Q-VECT CONV AND FGEN FORCING.
THERE HAS ALSO BEEN SOME UPSLOPE DZ AT KMQT EARLY THIS MORNING IN
NRLY FLOW.
PCPN TRENDS/COVERAGE WILL BE THE MAIN FCST ISSUES IN THE SHORT TERM.
ZONAL FLOW ACROSS SRN CANADA/FAR NRN CONUS IS EXPECTED TO BUCKLE
TODAY AS HEIGHT RISES OVER WRN NAMERICA FORCE DOWNSTREAM HEIGHT
FALLS INTO MISSISSIPPI VALLEY REGION. THIS WILL HELP EJECT THE
CENTRAL PLAINS SHORTWAVE NE INTO THE GREAT LAKES THIS AFTERNOON.
EXACTLY HOW FAR N THE SHORTWAVE LIFTS ACROSS LOWER MI WILL BE
IMPORTANT TO THE PCPN COVERAGE TODAY. EVEN NOW...SO CLOSE TO THE
ONSET OF THE EVENT...THE MODELS ARE STILL EXHIBITING SIGNIFICANT RUN
TO RUN DIFFERENCES. THE MAJORITY OF THE 00Z RUNS WERE SHOWING THE
MAIN PCPN BAND STAYING MAINLY SOUTH OF THE FCST AREA...BRUSHING THE
FAR SCNTRL AND ERN FCST AREA WITH AROUND A HALF INCH OF RAINFALL
WITH A FAIRLY SHARP CUT-OFF OF PCPN HEADING NORTH AND WEST. NOW THE
06Z NAM AND GFS HAVE TRENDED FARTHER NORTH AND WEST WITH PCPN
SHIELD...STILL DROPPING THE HEAVIEST RAIN OVER THE SCNTRL AND EAST
BUT ALSO BRINGING ANYWHERE FROM 0.25-0.50 INCH INTO DICKINSON AND SE
HALF OF MQT COUNTY.
LATEST RADAR TRENDS AND MODEL FGEN FIELDS SUGGEST A SLIGHT NORTHWARD
TREND IN MAIN PCPN BAND IS POSSIBLE AS SHORTWAVE LIFTS TOWARD REGION
TODAY AND THIS WILL BE SOMETHING TO WATCH AS THE MORNING PROGRESSES.
SHORT TERM FCST UPDATES MAY NEED TO EXPAND CATEGORICAL POPS OVER FAR
SCNTRL AND ERN FCST AREA FARTHER NW TO ACCOUNT FOR THESE PCPN
TRENDS.
TONIGHT...AS SHORTWAVE AND ASSOC SFC LOW LIFT EAST OF THE REGION
LATER TONIGHT...EXPECT PCPN TO TAPER OFF OVER CENTRAL PORTIONS OF
THE CWA THIS EVENING AND OVER ERN PORTIONS OVERNIGHT. WITH MARGINAL
COLD ADVECTION BEHIND THE SYSTEM TONIGHT...AND BUFR SNDGS AND WET
BULB ZERO HGTS NOT REALLY SUPPORTING MUCH IN THE WAY OF PCPN
MIXING/CHANGING TO SNOW LATE TONIGHT...HAVE DECIDED TO PULL MENTION
OF SNOW LATE TONIGHT FOR NCNTRL ZONES. STRONG DEEP CYCLONIC NRLY
FLOW WILL LIKELY SUPPORT SOME LAKE EFFECT UPSLOPE RAIN/DZ THROUGH
MUCH OF NIGHT OVER NCNTRL PORTIONS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 610 AM EDT SUN OCT 14 2012
UPPER LEVEL PATTERN TO BEGIN THE LONG TERM ON MONDAY HAS A TROUGH
FROM HUDSON BAY INTO THE OHIO VALLEY WITH ASSOCIATED SFC LOW LIFTING
INTO SOUTHERN QUEBEC. KEPT MENTION OF LIGHT LK EFFECT PRECIP FIRST
THING ON MONDAY MORNING OVER NORTH CENTRAL WITH H85 TEMPS DOWN TO
-3C LEADING TO MARGINAL OVER-WATER INSTABILITY WITH DELTA T/S OVER
15C. SOUNDINGS FOR MQT FROM GFS/NAM INDICATE WBZERO HEIGHTS STAYING
AOA 1000FT AGL SO KEPT PTYPE AS ONLY RAIN. EVEN WITH CYCLONIC
NORTHERLY FLOW IN WAKE OF SFC LOW MOVING INTO QUEBEC...SOUNDINGS
SHOW ONLY A SHALLOW MOIST LAYER AFTER 12Z MONDAY WITH TEMPS IN THE
MOIST LAYER NOT ANY COLDER THAN -5C. SO...MAY JUST END UP WITH
FINE DRIZZLE OR MAYBE JUST A FEW SPRINKLES SINCE SUB CLOUD LAYER IS
INCREASINLY MIXED WITH INVERTED-V LOOK.
SFC RIDGE FOLLOWING IN WAKE OF THE SFC LOW SHOULD BE IN PROCESS OF
WORKING ACROSS UPPER GREAT LAKES BY AFTN WHICH WILL CONK OUT ANY
LINGERING RAIN SHOWERS/DRIZZLE/SPRINKLES. CLOUDS USUALLY TOUGHER TO
GO AND WOULD EXPECT SCT-BKN STRATOCU TO HANG AROUND TIL LATER AFTN
AS H85 RIDGE BEGINS TO MOVE INTO THE AREA.
UPPER FLOW BECOMES MORE WESTERLY INTO TUESDAY ALLOWING WEAK SFC
TROUGH/WARM FRONT TO SKIRT ACROSS NORTHERN ONTARIO AND UPPER GREAT
LAKES. ALTHOUGH SFC REFLECTION IS WEAK...ACTUALLY IS STRONG WARM AIR
ADVECTION ALOFT WITH THE AHEAD AND ALONG SHORTWAVE PASSING OVER THE
REGION. ISENTROPIC ASCENT ON THE 300K SFC /H8-H7/ IMPACTS MOST OF
CWA...BUT STRONGEST H85 TEMP ADVECTION IS MORE OVER THE NORTH CWA.
OVERALL A PERIOD OF MOISTURE/STRONG UVM IN THE H7-H5 LAYER /TEMPS
BLO -10C/ ARE FORECAST WHICH SHOULD IN TURN LEAD TO GREATER CHANCE
OF SEEING SOME RAIN MAKE IT TO SFC DESPITE DRY SUB H85 LAYERS MODELS
SHOW. LOOKS LIKE HIGHER POP/LOW QPF SETUP. INCREASED POPS TO LIKELY
OVER NORTH AND ALSO EAST. HIGH CHANCES SHOULD COVER IT FOR AREAS
FARTHER AWAY FROM MID LEVEL LIFT. MID LEVEL MOISTURE/UVM EXITS TO
THE FAR EAST CWA BY LATE DAY...SO HAVE TRIMMED BACK POPS IN THE WEST
AFTER 18Z AND FOR ALL AREAS ON INTO TUESDAY NIGHT. DESPITE
CLOUDS/SHOWERS...WARMING TEMPS ALOFT AND A SOUTH WIND SHOULD ALLOW
FOR TEMPS TO PUSH ABOVE NORMAL...ESPECIALLY DURING AFTN AS PRECIP
TAPERS OFF. COULD SEE SOME SPOTS ON TUESDAY TOUCH 60 DEGREES IF
ENOUGH THINNING IN OVERCAST OCCURS. BEST SHOT FOR WARMER TEMPS IN
THE WEST AND SOUTHWEST CWA.
ATTENTION TUESDAY NIGHT INTO WEDNESDAY WILL BE ON SHORTWAVE TROUGH
AND STRONG UPPER LEVEL JET DIGGING INTO PACIFIC NORTHWEST.
ASSOCIATED SFC LOW /PRETTY DEEP AT SUB 985MB/ FORMS OVER SOUTHERN
ALBERTA LATER TUESDAY WITH COMPLEX OF LOWS THEN DEVELOPING FROM
SASKATCHEWAN INTO MINNESOTA AND WESTERN WISCONSIN BY LATE DAY ON
WEDNESDAY. SLIGHT POTENTIAL FOR COUPLE BATCHES OF MID LEVEL MOISTURE
LIFTING ACROSS TUESDAY NIGHT TO YIELD SPRINKLES OR A SHOWER ON
TUESDAY NIGHT. FOR MOST PART THOUGH THE NIGHT SHOULD END UP DRY
AND FAIRLY MILD FOR MID-LATE OCTOBER WITH LOWS IN THE MID-UPPER 40S.
NOW SEEMS LIKE WEDNESDAY WILL BE FOR MOST PART FAIRLY VOID OF SIG
PRECIP OVER THE CWA. UPPER TROUGH AND IDEAL JET SUPPORT FOR PRECIP
REMAIN WELL TO WEST OVER MIDDLE MISSISSIPPI RIVER VALLEY. ALSO
SOME INDICATION FROM LATEST ECMWF THAT SHARPER SHORTWAVE EMBEDDED IN
SOUTHERN PORTION OF UPR TROUGH WILL FOCUS SFC LOW FARTHER SOUTH OVER
SOUTHERN IOWA WHICH KEEPS H85 JET AND HIGHER H85 DWPNT LOCKED UP
MORE TO SOUTHWEST OF CWA. KEPT CHANCE POPS OVER WEST AND SOUTHWEST
CWA...BUT DID TRIM TO ONLY SLIGHT CHANCES OVER THE EASTERN CWA.
SIMILAR TO TUESDAY...GIVEN WARM AIR ALOFT /H85 TEMPS PUSHING +10C
OVER SOUTH CWA/ AND SOUTHERLY WINDS...MAX TEMPS COULD PUSH PAST 60
DEGREES AGAIN. TRENDS IN CLOUD COVER WILL HAVE BIG IMPACT ON TEMPS
THOUGH AS IF PARTIAL CLEARING COULD OCCUR OVER CWA...TEMPS MAKING
RUN WELL INTO THE 60S /EVEN AN ISOLD 70 DEGREE READING/ WOULD BE
FEASIBLE.
BEYOND WEDNESDAY MODELS DIVERGE WITH HANDLING OF TROUGH AND SFC
LOW TO CLOSE THE WEEK. GFS BECOMES MORE PROGRESSIVE WITH LOW PUSHING
TOWARD LK MICHIGAN BY THURSDAY AFTERNOON WHILE ECMWF AND GEM-NHEM
SHOW MORE OF A SLOWER UPPER TROUGH PROGRESSION AND KEEP PRIMARY SFC
LOW LUMBERING MORE OVER SOUTHERN PORTION OF MINNESOTA THROUGH
THURSDAY. SFC LOW PLACEMENT PRETTY MUCH ALL OVER THE PLACE IN MORE
RECENT MODEL RUNS. SINCE THE SYSTEM IS VERY WRAPPED UP ON ALL
MODELS...POTENTIAL IS THERE FOR SIGNIFICANT DRY SLOTTING SOMETIME
THURSDAY INTO FRIDAY ALONG WITH MINOR SHORTWAVES ROTATING AROUND
MAIN UPPER LOW. LEANED HEAVILY ON CONSENSUS FOR POPS/SKY/WINDS FOR
THURSDAY AND BEYOND DUE TO LACK OF CONSISTENCY IN ANY OF THE MODELS
AND VARYING SOLUTIONS WITH HANDLING OF UPPER TROUGH/SFC LOW. COULD
EASILY SEE WINDS BEING MUCH STRONGER THAN IS SHOWN WITH THIS
FORECAST...ESPECIALLY THURSDAY AND FRIDAY...BUT AT THIS POINT
CANNOT PIN POINT WHERE THE STRONGER WINDS WILL OCCUR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 213 AM EDT SUN OCT 14 2012
LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE NORTHEAST TOWARD THE
WRN GREAT LAKES DURING THE FCST PERIOD. AT KIWD...WILL CONTINUE TO
SEE VLIFR CONDITIONS/-DZ LATER TONIGHT AS NNE WINDS STRENGTHEN
ACROSS LAKE SUPERIOR FOR SOME UPSLOPE. DRIER AIR GETS ADVECTED IN BY
AFTERNOON WITH MVFR CONDITIONS EXPECTED THROUGH THE REST OF THE
PERIOD AT KIWD. AT KCMX...MVFR CONDITIONS SHOULD GENERALLY PREVAIL
OVERNIGHT INTO SUNDAY IN MOSTLY DOWNSLOPE NE FLOW. AT KSAW...LOW
MVFR CONDITIONS WILL FALL BACK TO LIFR CONDITIONS LATER TONIGHT/SUN
AS UPSLOPE NNE WINDS STRENGTHEN. DRIER AIR LATE IN THE AFTERNOON
SHOULD BRING MVFR CONDITIONS TO KSAW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 610 AM EDT SUN OCT 14 2012
EXPECT N TO NE WINDS TO INCREASE TODAY AS LOW PRES OVER THE CENTRAL
PLAINS LIFTS NE INTO NRN LWR MICHIGAN THIS AFTERNOON. DURING THE
AFTN...WINDS SHOULD BE IN THE 20-30KT RANGE OVER THE CNTRL AND ERN
PORTIONS OF LAKE SUPERIOR. WINDS WILL BE LIGHTER OVER THE FAR W.
EXPECT NORTHERLY GALES TO DEVELOP OVER EASTERN LAKE SUPERIOR THIS
EVENING AND THEN CONTINUE INTO MONDAY MORNING AS THE LOW RAPIDLY
DEEPENS AND MOVES EAST OF THE AREA AND HIGH PRESSURE PUSHES IN FROM
THE WEST. WINDS SETTLE DOWN MONDAY AFTERNOON AND MONDAY NIGHT WITH
ARRIVAL OF HIGH PRESSURE. ANOTHER LOW PRESSURE WILL MOVE INTO THE
UPPER GREAT LAKES ON WEDNESDAY. SOUTH WINDS AHEAD OF THIS LOW COULD
BRIEFLY REACH GALES TO 35 KTS OVER ERN LAKE SUPERIOR TUE AFTERNOON.
OTHERWISE...WINDS IN THE VICINITY OF THE LOW SHOULD REMAIN LESS THAN
20 KTS WEDNESDAY INTO THURSDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 7 PM THIS EVENING TO 10 AM EDT MONDAY FOR
LSZ266-267.
LAKE MICHIGAN...
GALE WARNING FROM 6 PM THIS EVENING TO 11 AM EDT MONDAY FOR
LMZ221-250.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...07
MARINE...VOSS
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
1022 AM CDT SUN OCT 14 2012
.DISCUSSION...LOW STRATUS REMAINS ACROSS PORTIONS OF THE DEVILS
LAKE BASIN AND INTO THE NORTHERN VALLEY. PATCHY DENSE FOG REMAINS
ACROSS PORTIONS OF THE DEVILS LAKE BASIN. SURFACE HIGH WILL BE
MOVING INTO THE DEVILS LAKE BASIN THIS AFTERNOON. THUS...LIGHT
WINDS WILL REMAIN THROUGH THE DAY HERE. MID OCTOBER SUN ANGLE
LIKELY NOT ENOUGH TO QUICKLY ERODE THIS CLOUD DECK UNTIL MAYBE
MID-AFTERNOON. USING THE 12Z HRRR AS A GUIDE...WILL UPDATE THIS
AREA TO MOSTLY CLOUDY INTO THE AFTERNOON HOURS. VISIBILITY IN THE
FOG SHOULD IMPROVE BY AFTERNOON. THE CLOUD DECK WILL AFFECT
TEMPS...AND DID NEED TO SIGNIFICANTLY LOWER MAX TEMPS WHERE CLOUDS
ARE EXPECTED TO REMAIN THE LONGEST. CLOUDS ALSO REMAIN ACROSS THE
FAR EASTERN FA...AND MADE SOME MINOR UPDATES HERE AS WELL. THE
SOUTHERN FA NEEDED NO CHANGES.
&&
.AVIATION...BEMIDJI AREA TO BE ON THE EDGE OF THE LOWER CLOUDS
AND FOG PATCHES WHICH PREVAIL JUST TO THE EAST...WHICH SHOULD
CLEAR THIS AFTERNOON. LOWER CLOUDS ALSO AFFECTING THE DEVILS LAKE
BASIN AND NORTHERN VALLEY AREAS...WHICH ARE EXPECTED TO REMAIN
INTO AT LEAST THE EARLY AFTERNOON HOURS. STILL SOME QUESTION
REGARDING WHAT THESE CLOUDS WILL DO.
&&
.PREV DISCUSSION... /ISSUED 853 AM CDT SUN OCT 14 2012/
UPDATE...INSERTED PATCHY DENSE FOG WITHIN THE DEVILS LAKE BASIN
FOR THE REMAINDER OF THE MORNING HOURS. WEB CAMS CONFIRM THE
FOG...AND HRRR INDICATES IT COULD REMAIN FOR A FEW MORE HOURS.
THIS SEEMS REASONABLE GIVEN LIGHT WIND REGIME. FOR NOW...THINKING
FOG/CLOUDS WILL CLEAR BY THE AFTERNOON ALLOWING FOR TEMPS TO RISE
TO NEAR FORECASTED VALUES. WILL TAKE A LOOK AT THE SITUATION AGAIN
IN A COUPLE HOURS.
PREV DISCUSSION... /ISSUED 335 AM CDT SUN OCT 14 2012/
SHORT TERM...
EARLIER COLD FRONT WHICH MOVED THROUGH THE FCST AREA MUCH MORE
ILL-DEFINED FROM NORTHEAST TO SOUTHWESTERN MINNESOTA AS THERE IS
AN AREA OF NORTH WINDS NORTH OF SURFACE LOW IN SOUTHWEST IOWA OVER
THE SOUTHEAST HALF OF MINNESOTA AND AN AREA OF NORTHWEST SFC WINDS
OVER NW MN AND ERN ND BEHIND ACTUAL COLD FRONT. AXIS OF LIGHT
WINDS FROM THE MN ARROWHEAD SOUTHWEST TOWARD ST CLOUD-WILMAR. IN
THIS ZONE THERE IS EXTENSIVE LOW CLOUDS AND FOG. WRN EDGE OF LOW
CLOUDS SKIRTING WADENA-BEMIDJI AREAS AND THIS IS LIKELY TO BE THE
CASE THROUGH THE REST OF THE EARLY MORNING. MOST OF THE FOG SHOULD
STAY EAST OF OUR AREA HOWEVER. OTHERWISE GOT SOME PATCHES OF
HIGH/MID LEVEL CLOUD COVER WITH TEMPS MOSTLY IN THE LOWER-MID 30S.
FOR TODAY...WATER VAPOR SHOWS SEVERAL WEAK SHORT WAVES IN SRN
SASKATCHEWAN WHICH ARE PROGGED TO MOVE EAST-SOUTHEAST THRU THE
AREA. UPSTREAM OBS/SATELLITE SHOWS SOME MID LEVEL CLOUDS. EVEN A
FEW LIGHT -SHRA IN SRN SASK INTO FAR NW ND. DO EXPECT A MIX OF
CLOUD/SUN TODAY WITH A GENERAL LIGHT NORTH- NORTHWEST WIND WITH
TEMPS A FEW DEGREES COOLER TODAY AS 925-850 MB COOL THRU 18Z
BEFORE WARMING A BIT LATE TODAY- TONIGHT. ATTM WILL NOT INCLUDE
ANY PRECIP...BUT NOT IMPOSSIBLE TO HAVE A FEW MID CLOUD SPRINKLES
BASED ON UPSTREAM OBS. LIGHT WINDS TONIGHT SHOULD ALLOW TEMPS TO
FALL OFF PRETTY QUICKLY IN MANY AREAS DESPITE WARMING JUST ABOVE
THE SFC. HOW COOL DEPENDS ON CLOUD COVER AS WILL PROBABLY HAVE
SOME PATCHES OF MID- HIGH CLOUDS AROUND.
MONDAY WILL SEE AN AREA OF THICKER MID LEVEL MOISTURE MOVE THRU
MAINLY IN RESPONSE TO 850 MB WARM ADVECTION. MODELS INSIST ON A
FEW SHOWERS OVER FAR NRN FCST AREA MONDAY LATE MORNING-AFTN SO
WILL CONTINUE TO MENTION. WILL CONTINUE MENTION INTO PARTS OF MON
NIGHT AS WELL OVER NW MN IN 850 MB WARM ADV ZONE. MONDAY HIGH
TEMPS LOOK NOT QUITE AS WARM AS PREVIOUSLY FORECASTED DUE TO CLOUD
COVER. ALL BLEND AND CONSALL TEMPS INDICATE HIGHS UPPER 50S
NORTHEAST TO LOWER 70S SOUTHWEST.
TUESDAY WILL BE GENERALLY DRY AND MILD BUT WILL SEE SOME LATE DAY
CHANCES FOR LIGHT RAIN ENTER THE DVL BASIN IN ADVANCE OF THE
LARGER MID WEEK SYSTEM.
LONG TERM (WEDNESDAY-SATURDAY)...
PACIFIC SHORTWAVE ENERGY IS EXPECTED TO CASCADE SOUTHEASTWARD ACROSS
THE CENTRAL US ON WEDNESDAY....FORMING A DEEP CLOSED LOW BY
WEDNESDAY NIGHT/THURSDAY. THE 00Z GFS IS FARTHEST EAST WITH THE
SYSTEM...WITH THE LOW CENTERED ACROSS WI...WHILE THE 00Z GEM AND
ESPECIALLY THE 00Z ECMWF ARE FARTHER WEST. THE MODELS DO AGREE THAT
A STRONG SFC LOW ASSOCIATED WITH THE UPPER LOW WILL DROP SOUTHEAST
OUT OF SOUTHERN CANADA AND OCCLUDE AS IT EVER SO SLOWLY PUSHES
ACROSS THE UPPER MIDWEST/GREAT LAKES THROUGH THE END OF THE WORK
WEEK. MODELS DIFFER QUITE A BIT ON THE PLACEMENT OF PRECIP WITH THE
SYSTEM...WITH THE FURTHER WEST GEM AND ECMWF SOLUTIONS SUGGESTING A
DECENT RAIN EVENT. HOWEVER...STILL A LOT OF QUESTIONS REGARDING THE
EVOLUTION OF THIS SYSTEM...AND OVERALL CONFIDENCE IN THE PLACEMENT
OF PRECIP IS LOW. NOT A LOT OF COLD AIR IS EXPECTED WITH THIS
SYSTEM...BUT WITH SOME LOW-LEVEL COLD ADVECTION WITH BRISK NORTH
WINDS ON THE BACK-SIDE OF THE LOW...AND EXTENSIVE
CLOUDS/SHOWERS...TEMPS ARE EXPECTED TO COOL DOWN BELOW SEASONAL
AVERAGES FOR THE LATTER HALF OF THE WORK WEEK.
LOW FORECAST CONFIDENCE EXISTS FOR FRIDAY/SATURDAY...WITH THE GFS
MORE PROGRESSIVE IN LIFTING THE UPPER LOW NORTHEASTWARD THAN THE
ECMWF. NEVERTHELESS...A GRADUAL DRYING TREND IS EXPECTED LATE IN THE
PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
TG
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
853 AM CDT SUN OCT 14 2012
.UPDATE...INSERTED PATCHY DENSE FOG WITHIN THE DEVILS LAKE BASIN
FOR THE REMAINDER OF THE MORNING HOURS. WEB CAMS CONFIRM THE
FOG...AND HRRR INDICATES IT COULD REMAIN FOR A FEW MORE HOURS.
THIS SEEMS REASONABLE GIVEN LIGHT WIND REGIME. FOR NOW...THINKING
FOG/CLOUDS WILL CLEAR BY THE AFTERNOON ALLOWING FOR TEMPS TO RISE
TO NEAR FORECASTED VALUES. WILL TAKE A LOOK AT THE SITUATION AGAIN
IN A COUPLE HOURS.
&&
.AVIATION...BEMIDJI AREA TO BE ON THE EDGE OF THE LOWER CLOUDS
AND FOG PATCHES WHICH PREVAIL JUST TO THE EAST. SO TAF FCST WILL
HAVE SOME MENTION OF MVFR VSBYS AND PSBL IFR CIGS THROUGH MID TO
LATE MORNING. DENSE FOG NEAR KDVL SHOULD DISSIPATE BY MID TO LATE
MORNING. OTHERWISE VFR TODAY WITH LIGHT NORTH-NORTHWEST WIND AND
SOME MID-HIGH LEVEL CLOUD COVER.
&&
.PREV DISCUSSION... /ISSUED 335 AM CDT SUN OCT 14 2012/
SHORT TERM...
EARLIER COLD FRONT WHICH MOVED THROUGH THE FCST AREA MUCH MORE
ILL-DEFINED FROM NORTHEAST TO SOUTHWESTERN MINNESOTA AS THERE IS
AN AREA OF NORTH WINDS NORTH OF SURFACE LOW IN SOUTHWEST IOWA OVER
THE SOUTHEAST HALF OF MINNESOTA AND AN AREA OF NORTHWEST SFC WINDS
OVER NW MN AND ERN ND BEHIND ACTUAL COLD FRONT. AXIS OF LIGHT
WINDS FROM THE MN ARROWHEAD SOUTHWEST TOWARD ST CLOUD-WILMAR. IN
THIS ZONE THERE IS EXTENSIVE LOW CLOUDS AND FOG. WRN EDGE OF LOW
CLOUDS SKIRTING WADENA-BEMIDJI AREAS AND THIS IS LIKELY TO BE THE
CASE THROUGH THE REST OF THE EARLY MORNING. MOST OF THE FOG SHOULD
STAY EAST OF OUR AREA HOWEVER. OTHERWISE GOT SOME PATCHES OF
HIGH/MID LEVEL CLOUD COVER WITH TEMPS MOSTLY IN THE LOWER-MID 30S.
FOR TODAY...WATER VAPOR SHOWS SEVERAL WEAK SHORT WAVES IN SRN
SASKATCHEWAN WHICH ARE PROGGED TO MOVE EAST-SOUTHEAST THRU THE
AREA. UPSTREAM OBS/SATELLITE SHOWS SOME MID LEVEL CLOUDS. EVEN A
FEW LIGHT -SHRA IN SRN SASK INTO FAR NW ND. DO EXPECT A MIX OF
CLOUD/SUN TODAY WITH A GENERAL LIGHT NORTH- NORTHWEST WIND WITH
TEMPS A FEW DEGREES COOLER TODAY AS 925-850 MB COOL THRU 18Z
BEFORE WARMING A BIT LATE TODAY- TONIGHT. ATTM WILL NOT INCLUDE
ANY PRECIP...BUT NOT IMPOSSIBLE TO HAVE A FEW MID CLOUD SPRINKLES
BASED ON UPSTREAM OBS. LIGHT WINDS TONIGHT SHOULD ALLOW TEMPS TO
FALL OFF PRETTY QUICKLY IN MANY AREAS DESPITE WARMING JUST ABOVE
THE SFC. HOW COOL DEPENDS ON CLOUD COVER AS WILL PROBABLY HAVE
SOME PATCHES OF MID- HIGH CLOUDS AROUND.
MONDAY WILL SEE AN AREA OF THICKER MID LEVEL MOISTURE MOVE THRU
MAINLY IN RESPONSE TO 850 MB WARM ADVECTION. MODELS INSIST ON A
FEW SHOWERS OVER FAR NRN FCST AREA MONDAY LATE MORNING-AFTN SO
WILL CONTINUE TO MENTION. WILL CONTINUE MENTION INTO PARTS OF MON
NIGHT AS WELL OVER NW MN IN 850 MB WARM ADV ZONE. MONDAY HIGH
TEMPS LOOK NOT QUITE AS WARM AS PREVIOUSLY FORECASTED DUE TO CLOUD
COVER. ALL BLEND AND CONSALL TEMPS INDICATE HIGHS UPPER 50S
NORTHEAST TO LOWER 70S SOUTHWEST.
TUESDAY WILL BE GENERALLY DRY AND MILD BUT WILL SEE SOME LATE DAY
CHANCES FOR LIGHT RAIN ENTER THE DVL BASIN IN ADVANCE OF THE
LARGER MID WEEK SYSTEM.
LONG TERM (WEDNESDAY-SATURDAY)...
PACIFIC SHORTWAVE ENERGY IS EXPECTED TO CASCADE SOUTHEASTWARD ACROSS
THE CENTRAL US ON WEDNESDAY....FORMING A DEEP CLOSED LOW BY
WEDNESDAY NIGHT/THURSDAY. THE 00Z GFS IS FARTHEST EAST WITH THE
SYSTEM...WITH THE LOW CENTERED ACROSS WI...WHILE THE 00Z GEM AND
ESPECIALLY THE 00Z ECMWF ARE FARTHER WEST. THE MODELS DO AGREE THAT
A STRONG SFC LOW ASSOCIATED WITH THE UPPER LOW WILL DROP SOUTHEAST
OUT OF SOUTHERN CANADA AND OCCLUDE AS IT EVER SO SLOWLY PUSHES
ACROSS THE UPPER MIDWEST/GREAT LAKES THROUGH THE END OF THE WORK
WEEK. MODELS DIFFER QUITE A BIT ON THE PLACEMENT OF PRECIP WITH THE
SYSTEM...WITH THE FURTHER WEST GEM AND ECMWF SOLUTIONS SUGGESTING A
DECENT RAIN EVENT. HOWEVER...STILL A LOT OF QUESTIONS REGARDING THE
EVOLUTION OF THIS SYSTEM...AND OVERALL CONFIDENCE IN THE PLACEMENT
OF PRECIP IS LOW. NOT A LOT OF COLD AIR IS EXPECTED WITH THIS
SYSTEM...BUT WITH SOME LOW-LEVEL COLD ADVECTION WITH BRISK NORTH
WINDS ON THE BACK-SIDE OF THE LOW...AND EXTENSIVE
CLOUDS/SHOWERS...TEMPS ARE EXPECTED TO COOL DOWN BELOW SEASONAL
AVERAGES FOR THE LATTER HALF OF THE WORK WEEK.
LOW FORECAST CONFIDENCE EXISTS FOR FRIDAY/SATURDAY...WITH THE GFS
MORE PROGRESSIVE IN LIFTING THE UPPER LOW NORTHEASTWARD THAN THE
ECMWF. NEVERTHELESS...A GRADUAL DRYING TREND IS EXPECTED LATE IN THE
PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
TG
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1104 AM EDT SUN OCT 14 2012
.SYNOPSIS...
A LOW PRESSURE SYSTEM LIFTING OUT OF THE PLAINS WILL TRAVEL NORTHEAST
INTO MICHIGAN. A STONG COLD FRONT EXTENDING SOUTH OF THE LOW WILL
PUSH ACROSS THE REGION...BRINGING STRONG WINDS AND THE CHANCE FOR
SEVERE THUNDERSTORMS LATE THIS AFTERNOON INTO TONIGHT. HIGH
PRESSURE AND DRIER AIR WILL ARRIVE BY LATE MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ADJUSTED TIMING OF PRECIP ONSET AS WELL AS CONVECTION. CURRENTLY
DIMINISHING OF SHOWERS OVER INDIANA SO HAVE DELAYED ONSET OF SCT
SHOWERS...AND WHILE THUNDERSTORMS POSSIBLE THIS AFTERNOON...SHOULD
BE MAINLY SHRA WITH ISOLATED TSTMS WITH SOME CONVECTIVE INHIBITION
EARLY. CAPE VALUES STILL NOT TERRIBLY IMPRESSIVE BUT ENOUGH TO
SPARK TSTMS ESPECIALLY NR/AFTER 20Z...WITH LATEST RAP PEAKING OUT AT
600 J/KG OVER INDIANA...AND THEN DIMINISHING SIGNIFICANTLY OVER
AREA BY 00Z-02Z. BEST SEVERE CHANCE WILL BE WITH STORMS THAT
DEVELOP AS CAPE STILL DECENT IN THE SW WHILE LL WIND FIELD STILL
IMPRESSIVE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
CDFNT WONT SWING THROUGH UNTIL AFTER 00Z TONIGHT. EXPECT A SECOND
LINE OF CONVECTION TO DEVELOP JUST AHEAD OF THE FRONT. NOT SURE IF
THIS SECOND LINE WILL BE SEVERE...DUE TO THE TIMING WHICH IS AFTER
SUNSET. WILL CARRY CATEGORICAL POPS BEFORE 06Z WITH EXPECTED
CONVECTION AHEAD OF THE FRONT.
COOLER AIR WILL BEGIN TO WORK IN BEHIND THE FRONT AFTER 06Z. ON
MONDAY...A DEEP H5 TROF WILL SWING ACROSS THE REGION. NW CAA WILL
COMBINE WITH THE LIFT FROM THE TROF TO KICK OFF SOME SCT SHRA.
BEST CHC WILL BE ACROSS THE N...BUT DID TAKE SLGT CHC POPS DOWN TO
THE OHIO RIVER.
SKIES WILL CLEAR QUICKLY MONDAY NIGHT AS A HIGH PRESSURE RIDGE
BUILDS IN FROM THE W. THE SFC RIDGE WILL PROVIDE DRY WEATHER ON
TUESDAY...BUT ZONAL FLOW AT H5 WILL ALLOW UPPER LEVEL MOISTURE TO
SPILL SOME CLOUDS INTO THE REGION.
DROPPED TEMPERATURES DOWN INTO THE UPPER 40S IN THE NW AND LOWER
50S ELSEWHERE FOR TONIGHT. THEN ON MONDAY...THE COOL NW FLOW WILL
HOLD TEMPERATURES DOWN INTO THE MID 50S ACROSS THE NW AND THE
LOWER 60S IN THE EXTREME S. CLEAR SKIES AND LIGHT WINDS WILL ALLOW
TEMPERATURES TO FALL INTO THE UPPER 30S MONDAY NIGHT...BUT
TEMPERATURES SHOULD REBOUND INTO THE 60S FOR TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
UPPER LEVEL FLOW PATTERN TO UNDERGO A TRANSITION WITH ENERGY FROM
THE PACIFIC NORTHWEST CARVING OUT A DEEP UPPER LOW OVER THE
NATIONS MID SECTION. WILL INTRODUCE CHC POPS INTO THE FAR WEST
WEDNESDAY NIGHT AHD OF AN APPROACHING FRONT. EXPECT ABOVE NORMAL
TEMPERATURES WEDNESDAY WITH HIGHS RANGING FROM THE UPPER 60S NORTH
TO THE LOWER 70S SOUTH.
WITH THE UPPER LOW DEEPENING AND SETTLING INTO THE UPPER MS VLY AN
OCCLUDED FRONT TO PUSH THRU OHIO THURSDAY NIGHT/EARLY FRIDAY. SOME
TIMING DIFFERENCES EXIST...SO WILL INCREASE POPS TO HIGH CHC
CATEGORY. TEMPS TO CONT TO BE ABOVE NORMAL ON THURSDAY WITH HIGHS
FROM THE LOWER 60S NORTHWEST TO UPPER 60S SE.
TIMING DIFFERENCES EXIST REGARDING THE PROGRESSION OF THE UPPER LOW
WITH THE ECMWF DEEPER AND SLOWER WITH THIS FEATURE SETTLING INTO THE
OHIO VALLEY AT THE END OF NEXT WEEK. GFS SOLN KEEPS THE UPPER LOW
FURTHER NORTH AND IS QUICKER OPENING UP THE LOW.
WILL TREND POPS LOWER INTO SLIGHT CHC CATEGORY FRIDAY INTO FRIDAY
NIGHT AND THEN BUMP BACK TO CHANCE SATURDAY WITH THE EFFECTS OF THE
UPPER LOW EXPECTED. TEMPERATURES TO TREND COLDER WITH HIGHS ON
FRIDAY RANGING FROM THE UPPER 50S NW TO THE MID 60S SE AND FROM THE
MID 50S NW TO NEAR 60 SE ON SATURDAY.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
PRIMARILY VFR CIGS WILL BE FOUND UNTIL SHOWERS COME IN AFTER ABOUT
18Z AND SPREAD EASTWARD FROM THE IN/OH LINE. OCCASIONAL MVFR
2500-3KFT CIGS MAY POP UP IN AN OBSERVATION OR TWO BUT ARE NOT
EXPECTED TO BE THE RULE UNTIL SHOWERS DEVELOP LATER.
SHOWERS IN THE AFTERNOON WILL GIVE WAY TO THUNDERSTORMS AFTER
ABOUT 20-22Z. A LINE OF CONVECTION IS MORE LIKELY TO BE THE
WEATHER MAKER EARLY THIS EVENING. UNTIL THIS COMES
THROUGH...SOUTHERLY WINDS WILL SEE GUSTS TOPPING 35KT AT TIMES IN
ANY LOCATION AFTER ABOUT 16Z. AFTER THE LINE OF STORMS COMES
THROUGH...WINDS WILL TURN MORE WESTERLY OVERNIGHT AND LOSE A GOOD
BIT OF THEIR KICK BUT STILL BE IN THE UNUSUALLY HIGH 15KT WITH
STRONGER GUSTS DURING THE OVERNIGHT HOURS.
LOWER MVFR CIGS POTENTIALLY DIPPING TO IFR WILL OCCUR IN THE POST-
FRONTAL AIRMASS UNDER THE COLD ADVECTION. DO NOT EXPECT ANY VSBY
RESTRICTIONS IN THESE LOWER CIGS.
.OUTLOOK...MVFR CEILINGS LIKELY SUNDAY NIGHT INTO MONDAY. MVFR
CEILINGS AND VISIBILITIES POSSIBLE THURSDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR OHZ026-034-035-
042>046-051>056-060>065-070>074-077>082-088.
KY...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR KYZ089>100.
IN...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR INZ050-058-059-
066-073>075-080.
&&
$$
SYNOPSIS...JDR/SITES
NEAR TERM...JDR
SHORT TERM...SITES
LONG TERM...AR
AVIATION...JDR
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
641 AM CDT SUN OCT 14 2012
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
258 AM CDT SUN OCT 14 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION TODAY AS WELL AS
PRECIPITATION CHANCES FOR MONDAY NIGHT THROUGH TUESDAY NIGHT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING BUILDING UP ACROSS THE WESTERN U.S. INTO BRITISH
COLUMBIA...A NORTHERN STREAM TROUGH OVER SOUTH CENTRAL CANADA AND
NORTH DAKOTA...AND AN UPPER LOW NEAR TOPEKA KS. ALSO OF INTEREST IS
120KT JET STREAK AROUND 200MB OVER LAKE SUPERIOR ACCORDING TO THE
RAP. THE COMBINATION OF UPPER DIVERGENCE IN THE RIGHT ENTRANCE
REGION OF THIS UPPER JET...THE PRESENCE OF LOW TO MID LEVEL
FRONTOGENESIS OVER THE SOUTHERN HALF OF THE FORECAST AREA SEEN JUST
BY CONVERGENCE IN 850MB PROFILER AND VWP DATA...AND PLENTIFUL
MOISTURE NOTED BY GOES PRECIPITABLE WATER VALUES OF 1.4 INCHES IN
THE SAME PLACE IS RESULTING IN A BAND OF SHOWERS AND EMBEDDED
THUNDERSTORMS. BACK EDGE OF THIS PRECIPITATION ALONG A LINE
EXTENDED FROM CHARLES CITY TO VIROQUA AND WISCONSIN DELLS.
NORTHWEST OF THIS LINE...PRECIPITABLE WATER VALUES DROP OFF
DRAMATICALLY... DOWN TO AROUND 0.75 INCH IN WEST CENTRAL MINNESOTA.
IN FACT...SATELLITE IMAGERY DEPICTS CLEARING OVER WESTERN
MINNESOTA AND THE EASTERN DAKOTAS. AT THE SURFACE...A 998MB LOW
WAS PRESENT IN SOUTHWEST IOWA WITH A WARM FRONT EXTENDING
NORTHEAST INTO SOUTHWEST WISCONSIN.
TODAY...MODELS DEPICT THE NORTHERN STREAM TROUGH OVER SOUTH CENTRAL
CANADA DROPPING DOWN INTO MINNESOTA AND IOWA...WHICH HELPS TO KICK
THE UPPER LOW NEAR TOPEKA NORTHEASTWARD. BY 00Z...MODELS HAVE THE
UPPER LOW AND THE ASSOCIATED SURFACE LOW IN CENTRAL LAKE MICHIGAN...
SLIGHTLY SLOWER THAN SEEN YESTERDAY. THE FORECAST AREA...IN
PARTICULAR THE SOUTHEAST HALF...WILL STAY IN THE DEFORMATION ON THE
NORTHWEST SIDE OF THE LOW TRACK WHICH IS QUITE FAVORABLE FOR
PRECIPITATION. IN FACT...THE CURRENT BAND OF SHOWERS AND EMBEDDED
THUNDERSTORMS SHOULD INTENSIFY THIS MORNING AS DPVA INCREASES FROM
THE APPROACHING UPPER LOW. FRONTOGENESIS FIELDS ALSO STRENGTHEN IN
RESPONSE TO THE INCREASING DPVA. PRECIPITATION WILL TAPER OFF IN THE
AFTERNOON WEST TO EAST AS THE UPPER JET...FRONTOGENESIS AND THE
OVERALL SYSTEM MOVE EAST AWAY FROM THE AREA. DECENT AMOUNT OF QPF
EXPECTED TODAY IN SOUTHEAST SECTIONS OF THE FORECAST AREA GIVEN
THE STRONG FORCING THIS MORNING AND PRECIPITABLE WATER VALUES NEAR
1.5 INCHES. BLEND OF GUIDANCE SUGGESTS UPWARDS OF 1 INCH BETWEEN
12-18Z FROM OELWEIN TO PRAIRIE DU CHIEN AND BOSCOBEL. ALTHOUGH
CLEARING IS NOT TOO FAR AWAY...OVER WESTERN MINNESOTA...14.00Z
NAM/14.03Z RAP SOUNDINGS SUGGEST IT WILL TAKE ITS TIME SHIFTING
EAST AS MOISTURE STAYS TRAPPED BELOW A SUBSIDENCE INVERSION AT
5000 FT. WILL PLAY THIS MORE PESSIMISTIC ROUTE COMPARED TO THE
QUICKER CLEARING GFS GIVEN THAT CLIMATOLOGICALLY CLOUD COVER TENDS
TO HOLD AROUND LONGER. WITH PLENTY OF CLOUDS AND 850MB TEMPS
FALLING FROM 8-12C AT 12Z TO 2-4C AT 00Z...ANTICIPATE TEMPERATURES
TO NOT RISE MUCH. IN FACT...READINGS COULD FALL...ESPECIALLY OVER
THE EASTERN TWO THIRDS OF THE AREA WHICH STAND NO CHANCE OF SEEING
SUN.
TONIGHT AND MONDAY...RAPID EVOLUTION OF THE UPPER AIR PATTERN IS
FORECAST OVER THE AREA DURING THIS TIME. THE NORTHERN STREAM TROUGH
DROPPING INTO IOWA AT 00Z IS PROGGED TO DIG INTO ILLINOIS BY 12Z...
THEN RIDGING SEEN OVER BRITISH COLUMBIA RIGHT NOW EXPECTED TO SHIFT
OVER THE AREA BY 00Z TUESDAY. NOT ANTICIPATING ANY PRECIPITATION
WITH THE NORTHERN STREAM TROUGH...NOR WITH THE WARM ADVECTION
ACCOMPANYING THE UPPER RIDGE BUILDING IN ON MONDAY...AS TOO MUCH
SUBSIDENCE AND DRYING FLOWS IN BEHIND THE CURRENT STORM SYSTEM.
WOULD HAVE SOME CONCERN ABOUT VALLEY FOG TONIGHT WITH SKIES LIKELY
TO CLEAR FROM WEST TO EAST AND LINGERING MOISTURE FROM TODAYS RAIN.
HOWEVER...THERE IS TOO MUCH OF A NORTHWEST BREEZE BETWEEN THE
DEPARTING STORM SYSTEM AND A SURFACE HIGH PRESSURE RIDGE BUILDING
INTO WESTERN MINNESOTA BY 12Z. THIS BREEZE SHOULD HELP KEEP
TEMPERATURES FROM DROPPING TOO MUCH AS WELL. GENERALLY FOLLOWED A
BLEND OF GUIDANCE FOR LOWS. WITH THE PASSAGE OF THE SURFACE RIDGE ON
MONDAY...MORE SUN AND 850MB TEMPS CLIMBING TO 4C EAST TO 7C WEST BY
00Z...SHOULD SEE A WARMER DAY. THE AFOREMENTIONED LATE IN THE DAY
850MB TEMPS SUPPORT HIGHS IN THE MID 50S TO LOWER 60S. THESE ARE
LOWER THAN PREVIOUSLY FORECAST BECAUSE MODELS ARE SLOWER IN BRINGING
THE WARMER AIR IN.
MONDAY NIGHT AND TUESDAY...MODELS DEPICT A SHORTWAVE TROUGH OVER
NORTH DAKOTA AT 00Z TUESDAY...PARTLY RESPONSIBLE FOR THE UPPER RIDGE
THAT MOVED INTO THE AREA ON MONDAY...MOVING QUICKLY TO THE EAST
AND PERHAPS EVEN WEAKENING. THIS WEAKENING MAKES SENSE AS THERE IS A
MUCH MORE IMPRESSIVE AND POTENT UPPER TROUGH DIGGING DOWN INTO THE
NORTHERN U.S. ROCKIES. QUESTION IS IF ANY PRECIPITATION WILL OCCUR
WITH THAT SHORTWAVE TROUGH THAT TRACKS TO OUR NORTH. 14.00Z NAM
KEEPS ALL PRECIPITATION WELL TO THE NORTH...FROM NORTHERN MINNESOTA
INTO THE U.P.. THE 14.00Z GFS SHOWS SOME PRECIP CROSSING THE
NORTHERN SECTIONS OF THE FORECAST AREA...THOUGH VARIOUS ISENTROPIC
LIFT LEVELS FROM 290-310K SHOW VERY LITTLE LIFT OCCURRING WITH IT.
PLUS...THE PRECIPITATION IS FALLING OUT OF A 9000 FT CEILING. ALL
MODELS HAVE CERTAINLY TRENDED DRIER AND LESS IMPRESSIVE WITH THE
SHORTWAVE TROUGH. HAVE DECIDED TO MAINTAIN SOME 20 PERCENT
CHANCES...MAINLY ON TUESDAY NORTHEAST OF I-94. IDEA HERE BEING THAT
IT MAY TAKE AWHILE TO SATURATE THE LOWER LEVELS WITH THE WARM
ADVECTION TO ALLOW PRECIPITATION TO OCCUR. ALTHOUGH WE MAY GET
LITTLE PRECIPITATION OVERALL WITH THE SHORTWAVE TROUGH...THERE IS
DEFINITE WARMING COMING INTO THE FORECAST AREA WITH IT. 850MB TEMPS
CLIMB TO AT LEAST 10-14C BY 18Z TUESDAY. WITH POTENTIAL FOR ANY WARM
ADVECTION MID CLOUDS TO CLEAR OUT ON TUESDAY...COULD SEE DECENT
MIXING. AS SUCH...HAVE BUMPED UP TEMPERATURES ABOUT 5 DEGREES TO
COME IN BETTER ALIGNMENT WITH GUIDANCE. MONDAY NIGHT STILL LOOKS
RELATIVELY MILD THANKS TO THE INCREASE IN MID CLOUDS AND SOME
SOUTHERLY BREEZE.
TUESDAY NIGHT...THE POTENT TROUGH DIGGING INTO THE NORTHERN ROCKIES
ON TUESDAY IS PROGGED TO DIVE DOWN INTO THE DAKOTAS. IMPRESSIVE
WINDY AND COLD ADVECTION SETUP BEHIND IT WITH MODEL PROGS OF A 980S
MB LOW NEAR LAKE WINNIPEG AND 1025-1030MB SURFACE HIGH OVER THE
NORTHWESTERN U.S.. FOR OUR AREA...WE ARE IN THE WARM ADVECTION SETUP
AHEAD OF THE LOW WITH INDICATIONS OF 500MB HEIGHTS FALLING AFTER
MIDNIGHT. THEREFORE...ANTICIPATING SOME MID AND HIGH CLOUDS
SPREADING WEST TO EAST AGAIN...LIKE MONDAY NIGHT. LOWER LEVEL
SATURATION BECOMES AN ISSUE FOR ANY PRECIPITATION TO FALL OUT OF
THESE CLOUDS. BOTH THE 14.00Z GFS AND NAM SUGGEST SOME LIGHT QPF CAN
FALL ACROSS NORTHWEST SECTIONS OF THE FORECAST AREA BETWEEN 06-12Z
WEDNESDAY...WHICH HAVE BEEN ACKNOWLEDGED WITH A 15-20 PERCENT
CHANCE. OTHERWISE...DRY CONDITIONS WITH A LIGHT SOUTHERLY BREEZE
WILL BE THE RULE. COMBINATION OF THAT SOUTHERLY BREEZE AND
CLOUDS...ALONG WITH DEWPOINTS WHICH SHOULD BE UP IN THE 40S IS
EXPECTED TO HELP HOLD LOWS UP IN THE MID 40S TO LOW 50S.
.LONG TERM...WEDNESDAY THROUGH SATURDAY NIGHT
258 AM CDT SUN OCT 14 2012
MAIN STORY FOR THE EXTENDED REVOLVES AROUND THAT POTENT UPPER TROUGH
DROPPING DOWN INTO THE DAKOTAS TUESDAY NIGHT. 14.00Z
ECMWF/GFS/CANADIAN AND GFS ENSEMBLES ALL SHOW THIS TROUGH DIGGING
INTO THE UPPER MISSISSIPPI RIVER VALLEY AND EASTERN MISSOURI RIVER V
REGIONS BY 12Z THURSDAY. AS THIS TROUGH DIGS...IT GRADUALLY PULLS UP
MORE AND MORE MOISTURE FROM THE GULF OF MEXICO. THEREFORE...
PRECIPITATION WITH IT SEEMS LIKELY. BIGGEST PROBLEM IS EVOLUTION OF
THE VARIOUS WARM AND COLD CONVEYOR BELTS AS THIS SYSTEM WRAPS
UP...WITH POTENTIAL OF A DRY SLOT COMING AROUND THE UPPER LOW TOO.
FOLLOWED THE CONSENSUS APPROACH FOR NOW WHICH INCREASES CHANCES TO
AROUND 50 ON WEDNESDAY...WITH THE EXPECTED WARM CONVEYOR BELT...
LOWER 30-40 PERCENT CHANCES ON WEDNESDAY NIGHT WITH A POSSIBLE DRY
SLOT...THEN 50 PERCENT CHANCES OVER MINNESOTA WITH THE COLD CONVEYOR
BELT TO 30 PERCENT CHANCES IN SOUTHEAST SECTIONS OF THE FORECAST
AREA WITH POSSIBLE DRY SLOT ON THURSDAY. AS TIME GETS CLOSER...THESE
CHANCES WILL NEED TO BE FURTHER REFINED WITH INCREASES AGAIN LIKELY.
WEDNESDAY STILL LOOKS RELATIVELY WARM BEING IN THE WARM CONVEYOR
BELT AND 850MB TEMPS UPWARDS OF 8-12C. MOST LOCATIONS SHOULD REACH
THE MID 50S TO MID 60S RANGE...WARMEST EAST WHERE PRECIPITATION
BEGINS LATER. COOLER WEATHER THEN ON TAP FOR THURSDAY WITH THE UPPER
TROUGH IN PLACE AND POSSIBLE PRECIPITATION. ALSO ADDED A MENTION OF
THUNDER TO NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN ON WEDNESDAY
WHERE BOTH THE 14.00Z GFS/ECMWF DEPICT SOME MUCAPE BUILDING UP.
AFTER THURSDAY...QUESTION IS HOW FAST THE UPPER LOW/TROUGH PUSHES
EAST. THE 14.00Z ECMWF/CANADIAN HAVE RIDGES AMPLIFYING ACROSS THE
WESTERN U.S. AND FROM NEW ENGLAND INTO QUEBEC...EFFECTIVELY BLOCKING
THE TROUGH FROM REALLY GOING ANYWHERE. THE 14.00Z GFS AND QUITE A
FEW OF ITS ENSEMBLE MEMBERS DO NOT HAVE AS MUCH RIDGING OVER NEW
ENGLAND AND QUEBEC...THUS ALLOWING THE TROUGH TO LIFT OUT. THINK
THIS LATTER SCENARIO IS TOO FAST AND THUS LEANING THE FORECAST MORE
TOWARDS THE CONSISTENT ECMWF/CANADIAN SOLUTIONS. THIS RESULTS IN
MAINTAINING COOL WEATHER WITH HIGHS IN THE LOW TO MID 50S ALONG WITH
LOW CHANCES OF PRECIPITATION THROUGH SATURDAY. REASON FOR THE LOW
PRECIPITATION CHANCES...GENERALLY 20-30...IS A COMBINATION OF MODEL
UNCERTAINTY ON THE EVOLUTION/TRACK OF THE UPPER LOW/TROUGH AS WELL
AS SUGGESTIONS OF THE UPPER LOW/TROUGH FILLING WITH TIME.
&&
.AVIATION...TODAY AND TONIGHT
641 AM CDT SUN OCT 14 2012
IFR/LIFR CONDITIONS WILL PERSIST AT THE TAF SITES THROUGH MID
MORNING AS A LOW PRESSURE SYSTEM LIFTS INTO NORTHERN ILLINOIS.
RAIN SHOWERS WILL CONTINUE AT KRST FOR A FEW MORE HOURS THIS
MORNING BEFORE ENDING AND SHIFTING EAST. THE RAIN IS EXPECTED TO
PERSIST AT KLSE THROUGH EARLY THIS AFTERNOON. CEILINGS THIS
MORNING WILL RANGE FROM 200 FT AT KRST TO AROUND 700 FT AT KSLE IN
LOW STRATUS. PLAN ON VISIBILITIES IN THE 4 TO 5 SM RANGE IN RAIN
AND BR. THE LOW WILL SHIFT EAST OF THE AREA THIS AFTERNOON WITH
SHOWERS ENDING AND CONDITIONS RAPIDLY IMPROVING TO MVFR AS
NORTHWEST WINDS INCREASE AND USHER IN DRIER AIR. LOOK FOR
CEILINGS TO RISE TO AROUND 1500 FT AT KRST BY 17Z...THEN
INCREASING TO AROUND 3500 FT BY 21Z WITH CLOUDS BECOMING
SCATTERED LATE IN THE AFTERNOON. THE STRATUS WILL LINGER A LITTLE
LONGER AT KLSE WITH CEILINGS CLIMBING TO AROUND 1000FT BY
16Z..THEN GRADUALLY RISING THROUGH THE AFTERNOON HOURS TO AROUND
3000 FT BY 22Z. VFR CONDITIONS ARE EXPECTED AT THE TAF SITES THIS
EVENING INTO THE OVERNIGHT HOURS AS HIGH PRESSURE BUILDS IN. WILL
HAVE TO KEEP AN EYE ON SHALLOW FOG POTENTIAL AT KLSE GIVEN THE
RECENT RAINS AND WINDS BECOMING LIGHT LATE TONIGHT. AT THIS TIME
IT APPEARS WINDS FROM JUST ABOVE THE SURFACE THROUGH 1 KFT WILL
STAY IN THE 12 TO 20 KT RANGE AND PROMOTE ENOUGH MIXING TO PREVENT
FOG DEVELOPMENT SO WILL NOT INCLUDE IT IN THE TAF AT THIS TIME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
258 AM CDT SUN OCT 14 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS MIAMI FL
154 PM EDT SUN OCT 14 2012
.AVIATION...
ISOLATED TO WIDELY SCATTERED RAIN SHOWERS CONTINUE TO PUSH WEST
ACROSS THE SOUTH FLORIDA PENINSULA THIS AFTERNOON AND INTO THE
EARLY EVENING HOURS DUE TO DECENT LOW LEVEL MOISTURE AND WEAK 700
MB DIVERGENCE. LATEST SHORT TERM GUIDANCE KEEPS MOST OF THE
PRECIPITATION ACROSS THE ATLANTIC AND GULF COASTAL WATERS THROUGH
THE LATE EVENING AND OVERNIGHT HOURS. KEPT VCSH MENTION OUT OF ALL
EAST COAST TAFS AFTER 00Z. GUSTY EAST-NORTHEASTERLY WINDS WILL
ALSO BEGIN TO DECREASE DURING THE EARLY MORNING HOURS TOMORROW.
OTHERWISE...VFR CONDITIONS SHOULD PREVAIL THROUGH THE PERIOD.
&&
.PREV DISCUSSION... /ISSUED 735 AM EDT SUN OCT 14 2012/
AVIATION...
STRONG NORTHEAST FLOW ACROSS THE ATLANTIC WILL CONTINUE
THIS MORNING INTO THIS AFTERNOON. STRATOCUMULUS IN THE 3 KFT TO 6
KFT RANGE WITH EMBEDDED SHOWERS WILL CONTINUE TO STREAM SOUTHWEST
ACROSS THE ATLANTIC WATERS THIS MORNING WITH THE EAST COAST TAF
SITES EXPERIENCING BRIEF PASSING SHOWERS FROM TIME TO TIME. BY THE
AFTERNOON SCATTERED SHOWERS ARE POSSIBLE WITH A SLIGHT CHANCE OF
THUNDERSTORMS BUT CONFIDENCE IS LOW WITH THE THUNDERSTORMS WITH
VCSH ASSIGNED TO ALL TERMINALS. THE STRONG NORTHEAST WINDS ARE
EXPECTED TO START DECREASING SLOWLY AROUND 00Z THIS EVENING.
PREV DISCUSSION... /ISSUED 415 AM EDT SUN OCT 14 2012/
.HIGH RISK OF RIP CURRENTS ATLANTIC BEACHES/MINOR COASTAL
FLOODING POSSIBLE BEFORE WINDS RELAX THROUGHOUT THE DAY...
DISCUSSION...THE PWAT ON THE MIAMI EVENING SOUNDING YESTERDAY WAS
ONLY 1.12 INCHES, BUT IT IS PROGGED TO INCREASE INTO THE 1.4-1.6
RANGE THIS AFTERNOON THROUGH MONDAY, BEFORE DRIER AIR INFILTRATES
SOUTH FL BEHIND A WEAK COLD FRONT MON NIGHT. THE RESULT IS THE
EXPECTATION OF SCATTERED SHOWERS, AND POSSIBLY A TSTORM OR TWO,
TODAY-MONDAY WITH THE FOCUS ALONG THE ATLANTIC COAST. THEN, AS A
DRIER AIRMASS ADVECTS INTO THE AREA MON NIGHT-TUE, LITTLE SHOWER
ACTIVITY IS EXPECTED. HOWEVER, WILL PLACE SLIGHT CHANCE EASTERN
HALF OF THE AREA AS THERE COULD BE JUST ENOUGH LOW LEVEL MOISTURE
TO SQUEEZE OUT A FEW SHOWERS ON A QUICK RETURN TO NE-E FLOW BEHIND
THE WEAK FRONTAL BOUNDARY...AS PER GFS/ECMWF MODEL LOW QPF FIELDS.
INSTABILITY INCREASES JUST SLIGHTLY TODAY-MON BUT STILL WEAK LAPSE
RATES. HOWEVER, CANNOT RULE OUT A TSTORM...AND HRRR SHOWS A COUPLE
OF ECHO TOPS TO 40KFT OVER THE SOUTHERN ATLANTIC AND SOUTHERN
INTERIOR OF SOUTH FL THIS AFTERNOON...SO WILL INCLUDE SLIGHT
CHANCE OF TSTORMS TODAY AND MONDAY.
A HIGH RISK OF RIP CURRENTS CONTINUES ALONG THE ATLANTIC BEACHES
TODAY. WINDS WILL GRADUALLY SUBSIDE, BUT THE HIGH RISK WILL PERSIST
THROUGH THE EVENING. MINOR COASTAL FLOODING WILL BE POSSIBLE,
ESPECIALLY AROUND HIGH TIDE AT AROUND SUNRISE THIS MORNING DUE TO
TIDES RUNNING ABOUT A HALF A FOOT ABOVE PREDICTED DUE TO THE STRONG
ONSHORE FLOW. SO WILL CONTINUE TO ADVERTISE THIS POTENTIAL.
SUBSIDING ONSHORE WINDS ALONG THE ATLANTIC COAST SHOULD SLIGHTLY
REDUCE THIS POTENTIAL INTO THE EARLY WORK WEEK, DESPITE TIDES
REMAINING HIGH DUE TO THE SPRING TIDE.
AGAIN, BEHIND THE FRONTAL PASSAGE MON NIGHT, A DRIER AIRMASS WILL
MOVE IN WITH RE-ENFORCING LOWER DEWPOINTS IN THE 60S AND JUST SLIGHT
RAIN CHANCES. A FEW SHOWERS WILL CONTINUE POSSIBLE ESPECIALLY
INTERIOR/EAST COAST THROUGH LATE WEEK. THEN ANOTHER STRONGER COLD
FRONT APPROACHES NEXT WEEKEND...AND MAY MOVE THROUGH, ALTHOUGH THE
LATEST GFS/ECMWF SHOW MUCH OF THE ENERGY NORTH OF OUR AREA. IN
OTHER WORDS, THEY`VE TRENDED LESS AGGRESSIVE WITH THE
FRONT, ESPECIALLY THE ECMWF MODEL. STILL, THERE LOOKS TO BE
ANOTHER COLD FRONTAL PASSAGE SOMETIME THIS WEEKEND. GIVEN TIMING
UNCERTAINTIES, MAINTAINED SLIGHT CHANCE OF SHOWERS THROUGH NEXT
WEEKEND. THE ECMWF SHOWS THE CLOSED MID/UPPER LOW A BIT FURTHER
SOUTH, PULLING UP HIGHER MOISTURE AND EVEN A POTENTIAL FOR TSTORMS
AHEAD/ALONG THE FRONT SATURDAY. WE CAN WATCH MODEL TRENDS. A LOT
OF UNCERTAINTY THIS FAR OUT.
MARINE...WILL CONTINUE THE SMALL CRAFT ADVISORY FOR THE OFFSHORE
GULF WATERS AND BISCAYNE BAY THIS MORNING, BUT DROPPED THE LAKE AS
OBS ARE BELOW 20 KT. THE SCA WILL CONTINUE FOR THE ATLANTIC TODAY,
AND THE PALM BEACH WATERS THROUGH 6Z TONIGHT DUE TO SEAS OF 7 FT
THROUGH THEN BEFORE SUBSIDING FURTHER AS WINDS CONTINUE TO RELAX
THROUGH THE DAY AND BEYOND.
FIRE WEATHER...NO CONCERNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 77 87 75 86 / 20 30 10 20
FORT LAUDERDALE 79 87 76 88 / 20 30 10 20
MIAMI 78 87 75 87 / 20 30 10 20
NAPLES 74 89 72 85 / 20 20 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR COASTAL
BROWARD-COASTAL MIAMI DADE-COASTAL PALM BEACH.
AM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR COASTAL
WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL OUT 20 NM-
WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL EXTENDING
FROM 20 NM TO THE TERRITORIAL WATERS OF THE BAHAMAS.
SMALL CRAFT ADVISORY UNTIL 2 AM EDT MONDAY FOR COASTAL WATERS
FROM JUPITER INLET TO DEERFIELD BEACH, FL OUT 20 NM-WATERS
FROM JUPITER INLET TO DEERFIELD BEACH, FL EXTENDING FROM 20
NM TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR BISCAYNE
BAY.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS GOODLAND KS
223 PM MDT SUN OCT 14 2012
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 1251 PM MDT SUN OCT 14 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW RIDGE ACROSS NORTHERN
ROCKIES WITH LARGE SCALE TROUGH STILL IN PLACE OVER UPPER
MISSISSIPPI RIVER VALLEY. NW FLOW REMAINS IN PLACE ACROSS THE PLAINS
BETWEEN THESE FEATURES. AT THE SURFACE HIGH PRESSURE IS IN PLACE
OVER EASTERN COLORADO...WITH A LARGE AREA OF LOW PRESSURE OVER THE
CENTRAL MISSISSIPPI RIVER VALLEY. BETWEEN THESE FEATURES...TIGHTENED
PRESSURE GRADIENT OVER THE CWA HAS LED TO GUSTY WINDS BETWEEN 25 AND
30 MPH. THESE WINDS SHOULD DIMINISH AROUND SUNSET WITH AN END OF
DAYTIME MIXING.
A SURFACE TROUGH WILL DEVELOP ALONG THE KS/CO STATE LINE BY EARLY
MONDAY MORNING...WITH GRADIENT RELAXING ACROSS THE CWA. RESULT WILL
BE DEVELOPMENT OF LIGHT SW WINDS AND WAA AT H85. DESPITE WARMER
TEMPS ALOFT...CLEAR SKIES AND CALM WINDS WILL SUPPORT GOOD
RADIATIONAL COOLING OVERNIGHT. MOST LOCATIONS SHOULD SEE LOWS IN THE
LOW TO MID 40S...AND UPPER 30S AT TRADITIONAL COLD SPOTS. H5 RIDGE
WILL CONTINUE TO BUILD EAST OVERNIGHT AND SHOULD BE OVER CWA BY
EARLY MONDAY MORNING. WITH LARGE SCALE SUBSIDENCE IN PLACE MOSTLY
CLEAR SKIES AND DRY CONDITIONS SHOULD PREVAIL THROUGH MONDAY.
AIR MASS WILL CONTINUE TO MODERATE THROUGH MONDAY AFTERNOON...WITH
H85 TEMPS ABOUT 5-7C WARMER THAN THIS AFTERNOON. THIS SHOULD
SUPPORT AFTERNOON HIGH TEMPERATURES IN THE UPPER 70S TO LOW 80S
ACROSS THE CWA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 217 PM MDT SUN OCT 14 2012
LATE MONDAY NIGHT AN UPPER LEVEL SHORT WAVE TROUGH AND SURFACE
TROUGH/WEAK COLD FRONT WILL MOVE THROUGH THE NORTHEAST HALF OF THE
AREA. SOUNDINGS SHOW LITTLE MOISTURE TO WORK WITH SO AM ONLY
ANTICIPATING A FEW CLOUDS DURING THE OVERNIGHT HOURS.
TUESDAY A SHORT WAVE RIDGE AND SURFACE HIGH FOLLOW THE SURFACE
TROUGH INTO THE AREA. WINDS TURN TO THE SOUTHWEST AS THE RIDGE
BUILDS IN CAUSING TEMPERATURES TO WARM WELL ABOVE NORMAL.
TUESDAY NIGHT A STRONGER COLD FRONT MOVES INTO THE AREA DURING THE
EVENING...AND EXITS THE AREA DURING THE OVERNIGHT HOURS. THERE IS
SOME 700-500MB MOISTURE TO WORK WITH...HOWEVER A DRY LAYER WILL
STILL EXIST BELOW 700MB. MODELS DISAGREE WITH THE 500 AND 300MB
JET PLACEMENT BEHIND THE FRONT...BUT THE MAJORITY OF THE MODELS
INDICATE THE LEFT EXIT REGION OF THE JET MAY BE IN A FAVORABLE
LOCATION FOR THE NORTHERN HALF OF THE AREA TO RECEIVE PRECIP. THE
DOWNFALL IS THE DRY LAYER PRESENT BETWEEN 700MB AND THE SURFACE
WILL PREVENT ANY PRECIP THAT MAY FORM FROM REACHING THE GROUND.
UPPER LEVEL LIFT IMPROVES BEHIND THE FRONT AS A DEEPENING LONG
WAVE TROUGH MOVES IN...BUT SOUNDINGS SHOW THE ENVIRONMENT DRYING
OUT BEHIND THE FRONT. IN ADDITION GEFS AND SREF MEMBERS PLACE THE
PRECIP NORTH OF THE TRI-STATE AREA. WITH UNCERTAINTIES REGARDING THE
AMOUNT OF MOISTURE AVAILABLE WILL ONLY PLACE IN SILENT CHANCES FOR
THE AREA.
FOR THE WEDNESDAY THROUGH SUNDAY PERIOD THE FORECAST WILL CONTINUE
TO BE DRY. THE LONG WAVE TROUGH WILL CONTINUE TO DEEPEN WEDNESDAY
AS IT PROGRESSES EAST...BECOMING A CLOSED LOW OVER THE UPPER
MIDWEST AND LINGERING THERE THROUGH SATURDAY. MEANWHILE NORTHWEST
WINDS WILL STRENGTHEN WEDNESDAY BEHIND THE COLD FRONT FROM TUESDAY
NIGHT. THURSDAY THE WINDS WILL STRENGTHEN FURTHER DUE TO 40-50KT
850MB WINDS WINDS MIXING DOWN. WEDNESDAY AND THURSDAY AFTERNOON
THE FIRE DANGER WILL INCREASE ACROSS THE AREA DUE TO WINDS GUSTING
TO 35 MPH ON WEDNESDAY...45 MPH ON THURSDAY WITH RELATIVE
HUMIDITIES AROUND 20 PERCENT BOTH DAYS. OTHERWISE TEMPERATURES
WILL BE NEAR TO BELOW NORMAL THROUGH FRIDAY THEN ABOVE NORMAL
TEMPERATURES RETURN FOR THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1109 AM MDT SUN OCT 14 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD AT KGLD AND KMCK.
NW WINDS WILL GUST BETWEEN 25-30KT AT BOTH TERMINALS THIS
AFTERNOON. WINDS WILL DECREASE AROUND SUNSET AND SHIFT TO THE
SOUTHWEST AND THE SURFACE TROUGH OVER EASTERN COLORADO MOVES EAST
AND THE GRADIENT RELAXES.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JTL
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1251 PM MDT SUN OCT 14 2012
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 1251 PM MDT SUN OCT 14 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW RIDGE ACROSS NORTHERN
ROCKIES WITH LARGE SCALE TROUGH STILL IN PLACE OVER UPPER
MISSISSIPPI RIVER VALLEY. NW FLOW REMAINS IN PLACE ACROSS THE PLAINS
BETWEEN THESE FEATURES. AT THE SURFACE HIGH PRESSURE IS IN PLACE
OVER EASTERN COLORADO...WITH A LARGE AREA OF LOW PRESSURE OVER THE
CENTRAL MISSISSIPPI RIVER VALLEY. BETWEEN THESE FEATURES...TIGHTENED
PRESSURE GRADIENT OVER THE CWA HAS LED TO GUSTY WINDS BETWEEN 25 AND
30 MPH. THESE WINDS SHOULD DIMINISH AROUND SUNSET WITH AN END OF
DAYTIME MIXING.
A SURFACE TROUGH WILL DEVELOP ALONG THE KS/CO STATE LINE BY EARLY
MONDAY MORNING...WITH GRADIENT RELAXING ACROSS THE CWA. RESULT WILL
BE DEVELOPMENT OF LIGHT SW WINDS AND WAA AT H85. DESPITE WARMER
TEMPS ALOFT...CLEAR SKIES AND CALM WINDS WILL SUPPORT GOOD
RADIATIONAL COOLING OVERNIGHT. MOST LOCATIONS SHOULD SEE LOWS IN THE
LOW TO MID 40S...AND UPPER 30S AT TRADITIONAL COLD SPOTS. H5 RIDGE
WILL CONTINUE TO BUILD EAST OVERNIGHT AND SHOULD BE OVER CWA BY
EARLY MONDAY MORNING. WITH LARGE SCALE SUBSIDENCE IN PLACE MOSTLY
CLEAR SKIES AND DRY CONDITIONS SHOULD PREVAIL THROUGH MONDAY.
AIR MASS WILL CONTINUE TO MODERATE THROUGH MONDAY AFTERNOON...WITH
H85 TEMPS ABOUT 5-7C WARMER THAN THIS AFTERNOON. THIS SHOULD
SUPPORT AFTERNOON HIGH TEMPERATURES IN THE UPPER 70S TO LOW 80S
ACROSS THE CWA.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 200 AM MDT SUN OCT 14 2012
THE EXTENDED PERIOD IS EXPECTED TO BE DRY FOLLOWING A
MOISTURE-LACKING FRONTAL PASSAGE ON WEDNESDAY. THIS COLD FRONT IS
EXPECTED TO PUSH THROUGH EARLY WEDNESDAY...ENDING THE RUN OF MILD
TEMPERATURES EARLIER IN THE WEEK. BEHIND THE FRONT THERE WILL BE
STRONG NORTHWEST WINDS WEDNESDAY AND THURSDAY WITH GUSTS UP TO 35
MPH. TEMPERATURES OVER THE PERIOD WILL BE NEAR NORMAL TO ABOVE
NORMAL AS AN UPPER LEVEL RIDGE DEVELOPS OVER THE ROCKIES LATE IN
THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1109 AM MDT SUN OCT 14 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD AT KGLD AND KMCK.
NW WINDS WILL GUST BETWEEN 25-30KT AT BOTH TERMINALS THIS
AFTERNOON. WINDS WILL DECREASE AROUND SUNSET AND SHIFT TO THE
SOUTHWEST AND THE SURFACE TROUGH OVER EASTERN COLORADO MOVES EAST
AND THE GRADIENT RELAXES.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JJM
AVIATION...DR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
627 PM EDT SUN OCT 14 2012
.UPDATE...
ISSUED AT 625 PM EDT SUN OCT 14 2012
DID AN EARLY UPDATE THIS EVENING TO ACCOUNT FOR A MORE EXTENSIVE
PERIOD OF RAIN ACROSS THE EASTERN HALF OF THE FORECAST AREA. THE LOW
OVER NRN MICHIGAN WILL BE SLOW TO MOVE NORTHEAST TONIGHT AS THE
UPPER TROUGH BECOMES NEGATIVELY TILTED. THIS WILL ALLOW FOR
DEEPENING TO CONTINUE THIS EVENING WITH A TROWAL TYPE FEATURE
EVENTUALLY DEVELOPING AS THE LOW OCCLUDES OUT. THIS TROWAL WILL HELP
TO STRENGTHEN THE FRONTOGENETIC FORCING TO THE NORTHWEST OF THE LOW
AND ALLOW FOR PCPN TO PERSIST FOR MUCH OF THE OVERNIGHT ACROSS THE
EASTERN 1/3 OF UPPER MICHIGAN. THE LATEST RAP RUN CLEARLY SHOWS PCPN
HANGING ON FOR MUCH OF THE NIGHT AT ERY. MEANWHILE...NORTH CENTRAL
UPPER MICHIGAN IS SEEING THE TERRAIN LIGHT UP DUE TO THE DEEPER
MOISTURE AND SLIGHTLY MORE NORTHERLY PBL FLOW. WITH ALL OF THIS
SAID...HAVE OPTED TO RAISE POPS TO CATEGORICAL THIS EVENING ACROSS
N-CENTRAL UPPER MICHIGAN AND THEN GRADUALLY DIMINISH OVERNIGHT AS
DRIER AIR MOVES IN. WILL ALSO MAINTAIN CATEGORICAL POPS ALL NIGHT
ACROSS THE EAST. SOME PLACES ACROSS THE EASTERN HALF OF UPPER MI
WILL SEE OVER 2 INCHES OF RAIN BY MONDAY MORNING. MANY PLACES ARE
ALREADY WELL OVER 1 INCH TODAY.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 351 PM EDT SUN OCT 14 2012
CURRENT /18Z/ ANALYSIS SHOWS A STRONG UPPER SHORTWAVE TROUGH
STRETCHING FROM N MN TO N IL...WITH AN ELONGATED 998MB SFC LOW FROM
N IL TO NE LOWER MI. THE NE PORTION OF THE SFC LOW SHOULD BEGIN TO
DOMINATE AS THE DRY SLOT IS MOVING OVER REDUCING STATIC
STABILITY...AND SINCE THE UPPER SHORTWAVE FOCUS OVER THIS
AREA...FAVORING CYCLOGENESIS. THE 850MB LOW IS JUST SE OF
MENOMINEE...WITH A LARGE SHIELD OF MODERATE TO HEAVY RAINFALL ON THE
NW SIDE OF THIS FEATURE. THE NW EXTENT OF THE RAIN SHIELD EXTENDS
FROM NEAR ARX...TO RHI...TO CRYSTAL FALLS...TO MQT...TO E LAKE
SUPERIOR. AS NOTED BEFORE...HEAVY RAIN HAS BEEN REPORTED...MAINLY
CLOSER TO LAKE MICHIGAN WITH RAIN AMOUNTS UP TO AN INCH SO FAR OVER
SCENTRAL UPPER M. ADDITIONALLY...UPSLOPE FLOW AND AMPLE LOW LEVEL
MOISTURE IS BRINGING DRIZZLE/BR AND RAIN SHOWERS TO MUCH OF THE REST
OF THE CWA. ON THE NW SIDE OF THE SYSTEM IS A SFC RIDGE THAT WILL
MOVE INTO THE CWA TOMORROW.
THE DEFORMATION/FGEN FORCING AXIS AND ASSOCIATED PRECIP IS NOT
EXPECTED TO MOVE MUCH MORE NW THAN WHAT IT IS NOW SINCE IT IS
PIVOTING AROUND THE 850MB LOW...AND IS ALREADY STARTING TO PUSH
SLOWLY E ALONG THE WI BORDER. AS THE UPPER SHORTWAVE MOVES TO THE
ERN CWA BY 06Z MON...THE SFC LOW WILL MOVE TO LAKE HURON AND THE
BAND OF SYNOPTIC PRECIP WILL MOVE TO THE FAR ERN CWA OR JUST E OF
THE CWA. AS MODERATELY COLD 850MB TEMPS OF -2C TO -4C MOVES OVER
LAKE SUPERIOR BY 06Z MON...EXPECT SOME ISOLATED TO SCATTERED LAKE
EFFECT RAIN SHOWERS AND DRIZZLE FROM THE NLY UPSLOPE FLOW. BY TIME
THE COLDER AIR MOVES INTO THE NEAR SFC LAYER...LOW LOW LEVEL
MOISTURE WILL BE PRESENT...SO NOW SNOW IS EXPECTED. THE LAKE EFFECT
PRECIP WILL TAPER OFF FROM W TO E AS DRIER LOW LEVEL AIR MOVES IN
WITH THE SFC RIDGE. THE RIDGE WILL MOVE TO NEAR IWD BY 18Z
MON...THEN TO THE CENTER OF THE CWA BY 00Z TUE...BRINGING A RETURN
OF WARMER 850MB TEMPS UP TO 4C.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 449 PM EDT SUN OCT 14 2012
MONDAY NIGHT INTO TUE...MDLS WERE IN REASONABLE AGREEMENT WITH THE
MID LEVEL AND SFC RIDGE SLIDING QUICKLY TO THE EAST AND A MAINLY
ZONAL PATTERN ACROSS THE NRN CONUS. WAA/ISENTROPIC LIFT AHEAD OF THE
NEXT SHORTWAVE TROUGH WILL BRING INCREASING CLOUDS ACROSS THE AREA
MON NIGHT WITH RAIN CHANCES SPREADING INTO WRN UPPER MI. MODERATE TO
STRONG 300K ASCENT WITH MOISTURE INFLOW BRINGING PWAT VALUES TO
AROUND AN INCH SUPPORT LIKELY POPS OVER MOST OF THE CWA...ESPECIALLY
FOR THE CNTRL AND EAST EVEN IF QPF VALUES ARE ONLY A TENTH OF TWO.
EXPECT THAT THE PCPN WILL TAPER OFF IN THE WEST HALF BY AFTERNOON
AND THE EAST LATE.
TUE NIGHT AND WED...MDLS SUGGEST THAT AS STRONG UPPER LEVEL JET
ENERGY INTO THE PAC NW DIGS TO THE SE A BROAD MID/UPPER LEVEL TROUGH
WILL DEVELOP OVER THE PLAINS. WAA WILL INCREASE AHEAD OF A SFC
TROUGH EXTENDED FROM SRN MANITOBA INTO WRN MN BY 12Z/WED. THE ECMWF
WAS PREFERRED WITH A SLIGHTLY LATER ARRIVAL OF ANY PCPN INTO UPPER
MI AS THE STRONGER FORCING WITH THE JET AND MID LEVEL LOW REMAIN TO
THE SW OF UPPER MI. EVEN THOUGH 850 MB TEMPS CLIMB TO AROUND
10C...INCREASING CLOUDS SHOULD LIMIT MAX READINGS TO AROUND 60.
THU-SUN...MDLS DIFFERENCES BECOME MORE SIGNFICANT AS THE GFS/GEFS
BECOME MORE PROGRESSIVE BY NEXT WEEKEND COMPARED TO THE 00Z ECMWF
AND ASSOCIATED ENSEMBLES. EVEN THOUGH THE 12Z ECMWF HAS TRENDED MORE
TOWARD THE GFS...CONFIDENCE IN THE OVERALL PATTERN AND DETAILS IS
LOW. EXPECT THE BEST CHANCE OF PCPN FROM WED NIGHT INTO THU AS THE
SFC TROUGH AND MOISTURE AXIS LIFTS INTO THE REGION. BEYOND THU...THE
POSITION OF THE DRY SLOT OR ADDITIONAL WEAK IMPULSES AROUND THE MID
LEVEL LOW IS VERY UNCERTAIN. ABOVE NORMAL TEMPS WILL COOL BACK AGAIN
AOB SEASONAL AVERAGES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 131 PM EDT SUN OCT 14 2012
AMPLE LOW LEVEL MOISTURE FLOWING AROUND A LOW PRESSURE SYSTEM
SOUTHEAST OF THE AREA WILL KEEP LOW CIGS...WITH DZ AND -RA INTO
TONIGHT. -RA AND LOW CIGS WILL STICK AROUND THE LONGEST AT SAW INTO
LATE TONIGHT. AS THE SYSTEM MOVES EAST AND A RIDGE OF HIGH PRESSURE
MOVES IN FROM THE WEST LATE TONIGHT INTO MON MORNING...CONDITIONS
WILL BEGIN TO IMPROVE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 301 PM EDT SUN OCT 14 2012
EXPECT N TO NE WINDS TO INCREASE INTO TONIGHT AS A LOW PRESSURE
SYSTEM OVER NORTHERN LAKE MICHIGAN LIFTS NE TO LAKE HURON BY LATE
TONIGHT. LATE THIS AFTERNOON AND EARLY EVENING...WINDS SHOULD BE IN
THE 20-30KT RANGE OVER PRIMARILY THE CENTRAL AND ERN PORTIONS OF
LAKE SUPERIOR. WINDS WILL BE LIGHTER OVER THE FAR WRN LAKE. EXPECT
NORTHERLY GALES TO DEVELOP OVER ROUGHLY THE EASTERN HALF OF LAKE
SUPERIOR LATE THIS EVENING AND THEN CONTINUE INTO MONDAY MORNING AS
THE LOW RAPIDLY DEEPENS AND MOVES EAST OF THE AREA AND HIGH PRESSURE
PUSHES IN FROM THE WEST. WINDS SETTLE DOWN MONDAY AFTERNOON AND
MONDAY NIGHT WITH ARRIVAL OF HIGH PRESSURE. ANOTHER LOW PRESSURE
SYSTEM WILL MOVE INTO THE UPPER GREAT LAKES ON WEDNESDAY INTO
WEDNESDAY NIGHT. SOUTH WINDS AHEAD OF THIS LOW COULD BRIEFLY REACH
GALES TO 35 KTS OVER ERN LAKE SUPERIOR TUE AFTERNOON.
OTHERWISE...WINDS IN THE VICINITY OF THE LOW SHOULD REMAIN LESS THAN
20 KTS WEDNESDAY THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 10 AM EDT MONDAY FOR LSZ249>251-266-267.
LAKE MICHIGAN...
GALE WARNING UNTIL 11 AM EDT MONDAY FOR LMZ221-250.
&&
$$
UPDATE...MRD
SHORT TERM...TITUS
LONG TERM...JLB
AVIATION...TITUS
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
452 PM EDT SUN OCT 14 2012
.SYNOPSIS...
ISSUED AT 400 PM EDT SUN OCT 14 2012
STRONG LOW PRESSURE WILL MOVE ACROSS NORTHERN LOWER MICHIGAN AND
LAKE HURON TONIGHT. THIS SYSTEM WILL CONTINUE TO PRODUCE SCATTERED
RAIN SHOWERS AND ISOLATED THUNDERSTORMS... SOME OF WHICH MAY PRODUCE
STRONG WIND GUSTS TONIGHT.
COOL AND BREEZY CONDITIONS WITH SCATTERED SHOWERS CAN BE EXPECTED ON
MONDAY ON THE BACK SIDE OF THE DEPARTING LOW PRESSURE SYSTEM. MILDER
WEATHER WILL RETURN FOR TUESDAY AND WEDNESDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 400 PM EDT SUN OCT 14 2012
HIGH SHEAR/LOW CAPE ENVIRONMENT THIS AFTERNOON AND EARLY EVENING AS
STRONG SHORTWAVE NEAR CHICAGO PIVOTS NORTHEAST. WARMS SECTOR OF
INTENSIFYING SFC CYCLONE HAS PUSHED FARTHER NORTH THAN EARLIER
EXPECTED AS MAIN SFC LOW DEEPENS OVER NRN LWR MI. SFC CAPES HAVE
RISEN ABV 500 J/KG WHICH DOESN/T SOUND LIKE MUCH BUT 0-6KM SHEAR IS
AROUND 60 KTS. SINCE WINDS AT 3-5K FT ARE AROUND 50 KTS... THERE IS
CONCERN THAT SOME OF THE DEVELOPING CONVECTION WILL PRODUCE DAMAGING
WIND GUSTS OR BRIEFLY ROTATE. OF PARTICULAR CONCERN IS THE SOMEWHAT
MORE ORGANIZED CONVECTION CURRENTLY AROUND CHICAGO WHICH IS HEADING
THIS WAY. THE CURRENT LIMITED SVR WX THREAT SHOULD END SHORTLY AFTER
SUNSET AS THE THE COLD FRONT SWEEPS THROUGH.
PERIOD OF STRONG/GUSTY SYNOPTIC WINDS IS EXPECTED LATER THIS EVENING
AS THE SFC LOW DEEPENS TO 988 OVER NRN LK HURON (LATEST RAP13 PROG).
WIND SPEEDS/GUSTS FROM THE WEST NORTHWEST ARE CURRENTLY EXPECTED TO
BE JUST BELOW WIND ADVISORY CRITERIA... BUT THIS WILL NEED TO BE
MONITORED OVER THE NEXT FEW HOURS.
COOL AND BREEZY CONDITIONS EXPECTED ON MONDAY AS THE LOW PULLS AWAY
WITH SOME LINGERING WRAPAROUND/COLD ADVECTION RAIN SHOWERS...
ESPECIALLY EARLY. THEN A COLD NIGHT WITH DECREASING CLOUDS/WIND ON
MONDAY NIGHT AS THE SFC RIDGE MOVES OVHD. ALREADY WARM ADVECTING
AGAIN ON TUESDAY IN PROGRESSIVE PATTERN. RETURNING SW FLOW MAY
SQUEEZE OUT A FEW LIGHT SHOWERS.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 400 PM EDT SUN OCT 14 2012
THE LONG TERM PORTION OF THE FCST WILL BE DOMINATED BY ONE MAIN
SYSTEM THAT LOOKS TO HOLD IN ACROSS THE AREA THROUGH MOST OF...IF
NOT ALL OF THE LONG TERM PERIOD THROUGH NEXT SUNDAY.
THE STRONG UPPER JET CURRENTLY JUST SOUTH OF THE GULF OF ALASKA WILL
BE THE MAIN DRIVING FORCE BEHIND THE SYSTEM THAT WILL AFFECT THE
AREA MOST OF THE LONG TERM. THIS JET IS EXPECTED TO HELP DIG A
STRONG SYSTEM ACROSS THE PLAINS OR UPPER MS RIVER VALLEY. MODELS ARE
EVENTUALLY CLOSING THE SYSTEM OFF...HOWEVER THEY DIFFER ON THE
EVENTUAL EVOLUTION.
EITHER WAY...IT LOOKS LIKE THE AREA IS IN FOR AN UNSETTLED PERIOD OF
WEATHER. THE SYSTEM SHOULD MOVE IN LATE WED/WED NIGHT WITH THE FRONT
APPROACHING THE AREA. THIS SHOULD BRING THE BEST CHC OF MORE
WIDESPREAD RAIN TO THE AREA. TEMPERATURES WILL REMAIN COOL WITH
SOMEWHAT LIMITED DIURNAL TEMPERATURES SWINGS DUE TO THE CLOUD COVER.
ONCE THE FRONT MOVES THROUGH ON THU...THE PCPN SHOULD BECOME MORE
SCATTERED AND UNCERTAIN DEPENDING ON THE MOVEMENT OF THE UPPER LOW
AND ANY DISTURBANCES THAT WILL BE ROTATING AROUND IT. THIS WILL
REQUIRE KEEPING A CHC OF RAIN IN THE FORECAST THROUGH AT LEAST THE
END OF THE WORK WEEK. WE ARE LEANING TOWARD THE EURO MODEL AND
KEEPING THE CHC OF RAIN IN THROUGH NEXT WEEKEND. THE GFS SEEMS TO
LIFT THE SYSTEM OUT A BIT TOO QUICK CONSIDERING HOW BIG AND CLOSED
OFF THIS SYSTEM IS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 448 PM EDT SUN OCT 14 2012
THIS IS A QUICK UPDATE BECUASE I UPDATED ALL OF THE TAFS TO TIME
THE LINE OF STORMS ACROSS THE CWA. I USED THE COMBINATION OF THE
TIME TOOL (ON AWIPS) AND THE HRRR RUC TO TIME THE STORMS THROUGH.
OVER THE PAST HOUR THE TIMING TOOL HAS TRACKED WELL AND WHERE THE
LINE IS NOW IS IN GOOD AGREEMENT WITH THE HRRR TIMING OF THE LINE.
AFTER THE LINE MOVES THROUGH I EXPECT VFR CIGS/VSBY BUT WINDY
CONDITIONS. THE WRAP AROUND LOW CLOUDS AND SHOWERS WILL IMPACT GRR
AND MKG MORE THAN AZO...BTL...JXN AND LAN BUT I TRIED TO TIME THAT
EAST TOO.
&&
.MARINE...
ISSUED AT 400 PM EDT SUN OCT 14 2012
SOUTH WINDS HAVE BRIEFLY GUSTED TO GALE FORCE RECENTLY... BUT MORE
PERSISTENT GALES FROM THE NW ARE LIKELY LATER THIS EVENING AND
OVERNIGHT ONCE THE SFC LOW PASSES BY. WINDS WILL DIMINISH LATE
MONDAY.
&&
.HYDROLOGY...
ISSUED AT 400 PM EDT SUN OCT 14 2012
MOST STORM TOTAL RAIN AMOUNTS HAVE BEEN ONE TO TWO INCHES...
ALTHOUGH SOME REPORTS HAVE BEEN HIGHER ESPECIALLY IN THE NW CWFA.
THERE HAVE BEEN NO REPORTS OF FLOODING DUE TO THE PROLONGED NATURE
OF THE EVENT...AND RIVERS WHICH WERE VERY LOW ARE STILL EXPECTED TO
REMAIN BELOW BANKFULL. ADDITIONAL RAIN AMOUNTS SHOULD BE MOSTLY A
HALF INCH OR LESS TONIGHT AND MONDAY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ844>849.
GALE WARNING FROM 8 PM THIS EVENING TO 5 AM EDT MONDAY FOR
LMZ844>849.
&&
$$
SYNOPSIS...MEADE
SHORT TERM...MEADE
LONG TERM...NJJ
AVIATION...WDM
HYDROLOGY...MEADE
MARINE...MEADE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
132 PM EDT SUN OCT 14 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 610 AM EDT SUN OCT 14 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS CONTINUE TO SHOW A ZONAL FLOW
ACROSS SRN CANADA AND THE FAR NRN CONUS WITH A WELL-DEFINED
SHORTWAVE OVER ERN KS AND WRN MO POISED TO LIFT NE TOWARD THE
CENTRAL GREAT LAKES THIS AFTERNOON. DEFORMATION/FRONTOGENESIS RAIN
BAND IN DEVELOPING BAROCLINIC LEAF/COMMA HEAD OF SHORTWAVE
STRETCHING FROM ERN NEBRASKA AND NRN IA INTO CENTRAL WI LINES UP
NICELY WITH 700 MB FGEN FORCING AS DEPICTED BY 00Z GFS. SO FAR EARLY
THIS MORNING...RADAR SHOW ONLY SPURIOUS SHRA ACTIVITY MOVING ACROSS
SCNTRL AND SE UPR MI IN AREA OF WEAK Q-VECT CONV AND FGEN FORCING.
THERE HAS ALSO BEEN SOME UPSLOPE DZ AT KMQT EARLY THIS MORNING IN
NRLY FLOW.
PCPN TRENDS/COVERAGE WILL BE THE MAIN FCST ISSUES IN THE SHORT TERM.
ZONAL FLOW ACROSS SRN CANADA/FAR NRN CONUS IS EXPECTED TO BUCKLE
TODAY AS HEIGHT RISES OVER WRN NAMERICA FORCE DOWNSTREAM HEIGHT
FALLS INTO MISSISSIPPI VALLEY REGION. THIS WILL HELP EJECT THE
CENTRAL PLAINS SHORTWAVE NE INTO THE GREAT LAKES THIS AFTERNOON.
EXACTLY HOW FAR N THE SHORTWAVE LIFTS ACROSS LOWER MI WILL BE
IMPORTANT TO THE PCPN COVERAGE TODAY. EVEN NOW...SO CLOSE TO THE
ONSET OF THE EVENT...THE MODELS ARE STILL EXHIBITING SIGNIFICANT RUN
TO RUN DIFFERENCES. THE MAJORITY OF THE 00Z RUNS WERE SHOWING THE
MAIN PCPN BAND STAYING MAINLY SOUTH OF THE FCST AREA...BRUSHING THE
FAR SCNTRL AND ERN FCST AREA WITH AROUND A HALF INCH OF RAINFALL
WITH A FAIRLY SHARP CUT-OFF OF PCPN HEADING NORTH AND WEST. NOW THE
06Z NAM AND GFS HAVE TRENDED FARTHER NORTH AND WEST WITH PCPN
SHIELD...STILL DROPPING THE HEAVIEST RAIN OVER THE SCNTRL AND EAST
BUT ALSO BRINGING ANYWHERE FROM 0.25-0.50 INCH INTO DICKINSON AND SE
HALF OF MQT COUNTY.
LATEST RADAR TRENDS AND MODEL FGEN FIELDS SUGGEST A SLIGHT NORTHWARD
TREND IN MAIN PCPN BAND IS POSSIBLE AS SHORTWAVE LIFTS TOWARD REGION
TODAY AND THIS WILL BE SOMETHING TO WATCH AS THE MORNING PROGRESSES.
SHORT TERM FCST UPDATES MAY NEED TO EXPAND CATEGORICAL POPS OVER FAR
SCNTRL AND ERN FCST AREA FARTHER NW TO ACCOUNT FOR THESE PCPN
TRENDS.
TONIGHT...AS SHORTWAVE AND ASSOC SFC LOW LIFT EAST OF THE REGION
LATER TONIGHT...EXPECT PCPN TO TAPER OFF OVER CENTRAL PORTIONS OF
THE CWA THIS EVENING AND OVER ERN PORTIONS OVERNIGHT. WITH MARGINAL
COLD ADVECTION BEHIND THE SYSTEM TONIGHT...AND BUFR SNDGS AND WET
BULB ZERO HGTS NOT REALLY SUPPORTING MUCH IN THE WAY OF PCPN
MIXING/CHANGING TO SNOW LATE TONIGHT...HAVE DECIDED TO PULL MENTION
OF SNOW LATE TONIGHT FOR NCNTRL ZONES. STRONG DEEP CYCLONIC NRLY
FLOW WILL LIKELY SUPPORT SOME LAKE EFFECT UPSLOPE RAIN/DZ THROUGH
MUCH OF NIGHT OVER NCNTRL PORTIONS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 610 AM EDT SUN OCT 14 2012
UPPER LEVEL PATTERN TO BEGIN THE LONG TERM ON MONDAY HAS A TROUGH
FROM HUDSON BAY INTO THE OHIO VALLEY WITH ASSOCIATED SFC LOW LIFTING
INTO SOUTHERN QUEBEC. KEPT MENTION OF LIGHT LK EFFECT PRECIP FIRST
THING ON MONDAY MORNING OVER NORTH CENTRAL WITH H85 TEMPS DOWN TO
-3C LEADING TO MARGINAL OVER-WATER INSTABILITY WITH DELTA T/S OVER
15C. SOUNDINGS FOR MQT FROM GFS/NAM INDICATE WBZERO HEIGHTS STAYING
AOA 1000FT AGL SO KEPT PTYPE AS ONLY RAIN. EVEN WITH CYCLONIC
NORTHERLY FLOW IN WAKE OF SFC LOW MOVING INTO QUEBEC...SOUNDINGS
SHOW ONLY A SHALLOW MOIST LAYER AFTER 12Z MONDAY WITH TEMPS IN THE
MOIST LAYER NOT ANY COLDER THAN -5C. SO...MAY JUST END UP WITH
FINE DRIZZLE OR MAYBE JUST A FEW SPRINKLES SINCE SUB CLOUD LAYER IS
INCREASINLY MIXED WITH INVERTED-V LOOK.
SFC RIDGE FOLLOWING IN WAKE OF THE SFC LOW SHOULD BE IN PROCESS OF
WORKING ACROSS UPPER GREAT LAKES BY AFTN WHICH WILL CONK OUT ANY
LINGERING RAIN SHOWERS/DRIZZLE/SPRINKLES. CLOUDS USUALLY TOUGHER TO
GO AND WOULD EXPECT SCT-BKN STRATOCU TO HANG AROUND TIL LATER AFTN
AS H85 RIDGE BEGINS TO MOVE INTO THE AREA.
UPPER FLOW BECOMES MORE WESTERLY INTO TUESDAY ALLOWING WEAK SFC
TROUGH/WARM FRONT TO SKIRT ACROSS NORTHERN ONTARIO AND UPPER GREAT
LAKES. ALTHOUGH SFC REFLECTION IS WEAK...ACTUALLY IS STRONG WARM AIR
ADVECTION ALOFT WITH THE AHEAD AND ALONG SHORTWAVE PASSING OVER THE
REGION. ISENTROPIC ASCENT ON THE 300K SFC /H8-H7/ IMPACTS MOST OF
CWA...BUT STRONGEST H85 TEMP ADVECTION IS MORE OVER THE NORTH CWA.
OVERALL A PERIOD OF MOISTURE/STRONG UVM IN THE H7-H5 LAYER /TEMPS
BLO -10C/ ARE FORECAST WHICH SHOULD IN TURN LEAD TO GREATER CHANCE
OF SEEING SOME RAIN MAKE IT TO SFC DESPITE DRY SUB H85 LAYERS MODELS
SHOW. LOOKS LIKE HIGHER POP/LOW QPF SETUP. INCREASED POPS TO LIKELY
OVER NORTH AND ALSO EAST. HIGH CHANCES SHOULD COVER IT FOR AREAS
FARTHER AWAY FROM MID LEVEL LIFT. MID LEVEL MOISTURE/UVM EXITS TO
THE FAR EAST CWA BY LATE DAY...SO HAVE TRIMMED BACK POPS IN THE WEST
AFTER 18Z AND FOR ALL AREAS ON INTO TUESDAY NIGHT. DESPITE
CLOUDS/SHOWERS...WARMING TEMPS ALOFT AND A SOUTH WIND SHOULD ALLOW
FOR TEMPS TO PUSH ABOVE NORMAL...ESPECIALLY DURING AFTN AS PRECIP
TAPERS OFF. COULD SEE SOME SPOTS ON TUESDAY TOUCH 60 DEGREES IF
ENOUGH THINNING IN OVERCAST OCCURS. BEST SHOT FOR WARMER TEMPS IN
THE WEST AND SOUTHWEST CWA.
ATTENTION TUESDAY NIGHT INTO WEDNESDAY WILL BE ON SHORTWAVE TROUGH
AND STRONG UPPER LEVEL JET DIGGING INTO PACIFIC NORTHWEST.
ASSOCIATED SFC LOW /PRETTY DEEP AT SUB 985MB/ FORMS OVER SOUTHERN
ALBERTA LATER TUESDAY WITH COMPLEX OF LOWS THEN DEVELOPING FROM
SASKATCHEWAN INTO MINNESOTA AND WESTERN WISCONSIN BY LATE DAY ON
WEDNESDAY. SLIGHT POTENTIAL FOR COUPLE BATCHES OF MID LEVEL MOISTURE
LIFTING ACROSS TUESDAY NIGHT TO YIELD SPRINKLES OR A SHOWER ON
TUESDAY NIGHT. FOR MOST PART THOUGH THE NIGHT SHOULD END UP DRY
AND FAIRLY MILD FOR MID-LATE OCTOBER WITH LOWS IN THE MID-UPPER 40S.
NOW SEEMS LIKE WEDNESDAY WILL BE FOR MOST PART FAIRLY VOID OF SIG
PRECIP OVER THE CWA. UPPER TROUGH AND IDEAL JET SUPPORT FOR PRECIP
REMAIN WELL TO WEST OVER MIDDLE MISSISSIPPI RIVER VALLEY. ALSO
SOME INDICATION FROM LATEST ECMWF THAT SHARPER SHORTWAVE EMBEDDED IN
SOUTHERN PORTION OF UPR TROUGH WILL FOCUS SFC LOW FARTHER SOUTH OVER
SOUTHERN IOWA WHICH KEEPS H85 JET AND HIGHER H85 DWPNT LOCKED UP
MORE TO SOUTHWEST OF CWA. KEPT CHANCE POPS OVER WEST AND SOUTHWEST
CWA...BUT DID TRIM TO ONLY SLIGHT CHANCES OVER THE EASTERN CWA.
SIMILAR TO TUESDAY...GIVEN WARM AIR ALOFT /H85 TEMPS PUSHING +10C
OVER SOUTH CWA/ AND SOUTHERLY WINDS...MAX TEMPS COULD PUSH PAST 60
DEGREES AGAIN. TRENDS IN CLOUD COVER WILL HAVE BIG IMPACT ON TEMPS
THOUGH AS IF PARTIAL CLEARING COULD OCCUR OVER CWA...TEMPS MAKING
RUN WELL INTO THE 60S /EVEN AN ISOLD 70 DEGREE READING/ WOULD BE
FEASIBLE.
BEYOND WEDNESDAY MODELS DIVERGE WITH HANDLING OF TROUGH AND SFC
LOW TO CLOSE THE WEEK. GFS BECOMES MORE PROGRESSIVE WITH LOW PUSHING
TOWARD LK MICHIGAN BY THURSDAY AFTERNOON WHILE ECMWF AND GEM-NHEM
SHOW MORE OF A SLOWER UPPER TROUGH PROGRESSION AND KEEP PRIMARY SFC
LOW LUMBERING MORE OVER SOUTHERN PORTION OF MINNESOTA THROUGH
THURSDAY. SFC LOW PLACEMENT PRETTY MUCH ALL OVER THE PLACE IN MORE
RECENT MODEL RUNS. SINCE THE SYSTEM IS VERY WRAPPED UP ON ALL
MODELS...POTENTIAL IS THERE FOR SIGNIFICANT DRY SLOTTING SOMETIME
THURSDAY INTO FRIDAY ALONG WITH MINOR SHORTWAVES ROTATING AROUND
MAIN UPPER LOW. LEANED HEAVILY ON CONSENSUS FOR POPS/SKY/WINDS FOR
THURSDAY AND BEYOND DUE TO LACK OF CONSISTENCY IN ANY OF THE MODELS
AND VARYING SOLUTIONS WITH HANDLING OF UPPER TROUGH/SFC LOW. COULD
EASILY SEE WINDS BEING MUCH STRONGER THAN IS SHOWN WITH THIS
FORECAST...ESPECIALLY THURSDAY AND FRIDAY...BUT AT THIS POINT
CANNOT PIN POINT WHERE THE STRONGER WINDS WILL OCCUR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 131 PM EDT SUN OCT 14 2012
AMPLE LOW LEVEL MOISTURE FLOWING AROUND A LOW PRESSURE SYSTEM
SOUTHEAST OF THE AREA WILL KEEP LOW CIGS...WITH DZ AND -RA INTO
TONIGHT. -RA AND LOW CIGS WILL STICK AROUND THE LONGEST AT SAW INTO
LATE TONIGHT. AS THE SYSTEM MOVES EAST AND A RIDGE OF HIGH PRESSURE
MOVES IN FROM THE WEST LATE TONIGHT INTO MON MORNING...CONDITIONS
WILL BEGIN TO IMPROVE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 610 AM EDT SUN OCT 14 2012
EXPECT N TO NE WINDS TO INCREASE TODAY AS LOW PRES OVER THE CENTRAL
PLAINS LIFTS NE INTO NRN LWR MICHIGAN THIS AFTERNOON. DURING THE
AFTN...WINDS SHOULD BE IN THE 20-30KT RANGE OVER THE CNTRL AND ERN
PORTIONS OF LAKE SUPERIOR. WINDS WILL BE LIGHTER OVER THE FAR W.
EXPECT NORTHERLY GALES TO DEVELOP OVER EASTERN LAKE SUPERIOR THIS
EVENING AND THEN CONTINUE INTO MONDAY MORNING AS THE LOW RAPIDLY
DEEPENS AND MOVES EAST OF THE AREA AND HIGH PRESSURE PUSHES IN FROM
THE WEST. WINDS SETTLE DOWN MONDAY AFTERNOON AND MONDAY NIGHT WITH
ARRIVAL OF HIGH PRESSURE. ANOTHER LOW PRESSURE WILL MOVE INTO THE
UPPER GREAT LAKES ON WEDNESDAY. SOUTH WINDS AHEAD OF THIS LOW COULD
BRIEFLY REACH GALES TO 35 KTS OVER ERN LAKE SUPERIOR TUE AFTERNOON.
OTHERWISE...WINDS IN THE VICINITY OF THE LOW SHOULD REMAIN LESS THAN
20 KTS WEDNESDAY INTO THURSDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 7 PM THIS EVENING TO 10 AM EDT MONDAY FOR
LSZ266-267.
LAKE MICHIGAN...
GALE WARNING FROM 6 PM THIS EVENING TO 11 AM EDT MONDAY FOR
LMZ221-250.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...TITUS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS JACKSON MS
420 PM CDT SUN OCT 14 2012
.SHORT TERM...
SHOWERS/THUNDERSTORM ACTIVITY ASSOCIATED WITH THE PREFRONTAL TROUGH
HAS ALL BUT DIMINISHED ACROSS THE ARKLAMISS THIS AFTERNOON LEAVING
JUST A FEW LIGHT SHOWERS PASSING OVER AREAS S OF THE NATCHEZ TRACE.
CLEARING CLOUD COVER ACROSS THE DELTA/NE LA HAS ALLOWED HEATING TO
WARM TEMPS INTO THE UPPER 70S/LOWER 80S ACCOMPANIED BY DEW POINTS IN
THE UPPER 60S/NEAR 70. LATEST RUC ANALYSIS SHOWS UNCAPPED SBCAPE
VALUES HAVE CLIMBED ABOVE 1500J/KG ACROSS THESE AREAS JUST AHEAD OF
THE COLD FRONT. FORCING ASSOCIATED WITH THE LEFT EXIT REGION OF A
STRENGTHENING UPPER JET STREAK NOSING IN FROM THE WEST WILL BEGIN TO
OVERSPREAD THESE UNSTABLE AREAS OVER THE NEXT 2 TO 3 HOURS AND WOULD
NOT BE SURPRISED IF AT LEAST A COUPLE STORMS DEVELOPED ALONG THE
FRONT AS WE HEAD INTO EVENING. DEEP LAYER SHEAR OF ~30KTS REMAINS
SUFFICIENT YET MARGINAL FOR SEVERE STORMS SO THE SEVERE WEATHER RISK
WITH ANY OF THIS ACTIVITY IS NOT A SLAM DUNK...BUT IS NOT OUT OF THE
QUESTION. WIND GUSTS WILL BE THE PRIMARY RISK IF ANYTHING CAN GET
GOING...BUT A TORNADO ISN`T COMPLETELY OUT OF THE QUESTION AS LOW
LEVEL SHEAR IN EXCESS OF 20KTS REMAINS ACROSS THIS REGION. WILL KEEP
THESE RISKS MENTIONED IN THE HWO THROUGH THE EVENING.
THE CONVECTIVE POTENTIAL HEADED INTO THE LATTER PART OF THE EVENING
WILL MOST LIKELY BE DOMINATED BY WHAT CAN GET GOING THROUGH EARLY
EVENING. IF STORMS DEVELOP THEN A FEW MAY PERSIST AND PUSH SE TOWARD
THE NATCHEZ TRACE CORRIDOR AS THE STRONG LIFT PUSHES IN...BUT IF
NOTHING DEVELOPS WE MAY NOT SEE MUCH PERSIST PAST 8 OR 9 PM. GIVEN
THE STRENGTH OF THE FORCING...ITS PLAUSIBLE WE COULD SEE ISOLATED
SHOWERS AHEAD OF THE FRONT THROUGH MOST OF THE NIGHT REGARDLESS.
HIGH PRESSURE IN WAKE OF THE FRONT WILL OVERSPREAD THE REGION
TOMORROW KEEPING THINGS DRY THROUGH THE MIDDLE OF THE WEEK. TEMPS
THROUGH THIS TIME WILL BE MUCH MORE SEASONAL ALTHOUGH HIGHS WILL
STILL BE COMING IN A TAD ABOVE NORMAL. RELEVANT SECTIONS OF THE
PREVIOUS LONGER TERM DISCUSSION HAVE BEEN APPENDED BELOW. /BK/
.LONG TERM...
BY WED...A VIGOROUS H5 S/WV TROUGH WILL PIVOT INTO THE CNTRL PLAINS.
DEEP SFC CYCLOGENESIS IS PROGGED TO OCCUR WITH A SUB 995MB SFC LOW
ACROSS MID/UPPER MS VALLEY THAT WILL BRING A POTENT COLD FRONT
TOWARDS THE REGION. AHEAD OF THE FRONT...PWATS WILL SURGE FROM S/SW
FLOW LATE WED/ERLY THURS TO NEAR 1.6-1.8" AS SFC DEWPOINTS CLIMB BACK
INTO THE LOW 60S.
ATTM...TIMING OF FROPA IS THURS MRNG PER 00Z EC/GFS WITH LOW
INSTABILITY BUT MODEST KINEMATICS. WILL HAVE TO KEEP WATCH OF THIS
SYSTEM IF SLOWER TIMING /AS 12Z ECMWF HINTED AT/ RESULTS IN GREATER
CONVECTIVE POTENTIAL IF FROPA OCCURS THURS AFTN. INCREASED POPS
ABOVE MEXMOS TOWARDS ECMEX VALUES THURS MRNG FOR NW AREAS WITH
DECREASING RAIN CHANCES BY THURS AFTN/NGT FROM NW TO SE. EC/GFS ARE
AT ODDS WITH DEGREE OF CAA AS EC KEEPS COOLER H85 TEMPS N/W OF
REGION WHILE GFS BARRELS SINGLE DIGIT H85 TEMPS ACROSS NRN ARKLAMISS
FRIDAY. HAVE FAVORED GFS GIVEN CONTINUED MEAN ENSEMBLE SUPPORT WITH
MEAN H5 TROUGH AXIS PLACEMENT JUXTAPOSED TO EC`S LONG RANGE H5
OMEGA BLOCK PATTERN. HIGHS FRI/SAT LOOK TO RANGE FROM NEAR 70 NORTH
TO MID 70S SOUTH WITH A SLIGHT WARM UP INTO SUNDAY WITH PROGGED
AMPLE SUNSHINE POST FROPA. /ALLEN/
&&
.AVIATION...THE CONVECTION ACROSS THE AREA THIS MORNING STABILIZED
THE AIRMASS BUT ADDITIONAL ACTIVITY WILL BE POSSIBLE ALONG A COLD
FRONT THAT WILL MOVE ACROSS THE AREA TONIGHT. EXPECT VFR CONDITIONS
OUTSIDE OF ANY TSTM ACTIVITY. THE COLD FRONT WILL PASS THROUGH THE
ENTIRE AREA BY DAYBREAK MONDAY AND EXPECT VFR CONDITIONS WILL
PREVAIL FOR THE ENTIRE AREA THROUGH MONDAY NIGHT AS HIGH PRESSURE
AND DRIER AIR BRINGS CLEAR SKIES. /22/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 57 79 49 78 / 23 0 0 5
MERIDIAN 59 80 45 77 / 23 0 0 3
VICKSBURG 53 80 46 78 / 27 0 0 5
HATTIESBURG 65 82 49 79 / 22 0 0 11
NATCHEZ 57 78 49 77 / 24 0 0 5
GREENVILLE 52 77 50 79 / 30 0 0 3
GREENWOOD 51 77 47 79 / 31 0 0 3
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
BK/22/ALLEN
AREA FORECAST DISCUSSION
NWS JACKSON MS
352 PM CDT SUN OCT 14 2012
.SHORT TERM...
SHOWERS/THUNDERSTORM ACTIVITY ASSOCIATED WITH THE PREFRONTAL TROUGH
HAS ALL BUT DIMINISHED ACROSS THE ARKLAMISS THIS AFTERNOON LEAVING
JUST A FEW LIGHT SHOWERS PASSING OVER AREAS S OF THE NATCHEZ TRACE.
CLEARING CLOUD COVER ACROSS THE DELTA/NE LA HAS ALLOWED HEATING TO
WARM TEMPS INTO THE UPPER 70S/LOWER 80S ACCOMPANIED BY DEW POINTS IN
THE UPPER 60S/NEAR 70. LATEST RUC ANALYSIS SHOWS UNCAPPED SBCAPE
VALUES HAVE CLIMBED ABOVE 1500J/KG ACROSS THESE AREAS JUST AHEAD OF
THE COLD FRONT. FORCING ASSOCIATED WITH THE LEFT EXIT REGION OF A
STRENGTHENING UPPER JET STREAK NOSING IN FROM THE WEST WILL BEGIN TO
OVERSPREAD THESE UNSTABLE AREAS OVER THE NEXT 2 TO 3 HOURS AND WOULD
NOT BE SURPRISED IF AT LEAST A COUPLE STORMS DEVELOPED ALONG THE
FRONT AS WE HEAD INTO EVENING. DEEP LAYER SHEAR OF ~30KTS REMAINS
SUFFICIENT YET MARGINAL FOR SEVERE STORMS SO THE SEVERE WEATHER RISK
WITH ANY OF THIS ACTIVITY IS NOT A SLAM DUNK...BUT IS NOT OUT OF THE
QUESTION. WIND GUSTS WILL BE THE PRIMARY RISK IF ANYTHING CAN GET
GOING...BUT A TORNADO ISN`T COMPLETELY OUT OF THE QUESTION AS LOW
LEVEL SHEAR IN EXCESS OF 20KTS REMAINS ACROSS THIS REGION. WILL KEEP
THESE RISKS MENTIONED IN THE HWO THROUGH THE EVENING.
THE CONVECTIVE POTENTIAL HEADED INTO THE LATTER PART OF THE EVENING
WILL MOST LIKELY BE DOMINATED BY WHAT CAN GET GOING THROUGH EARLY
EVENING. IF STORMS DEVELOP THEN A FEW MAY PERSIST AND PUSH SE TOWARD
THE NATCHEZ TRACE CORRIDOR AS THE STRONG LIFT PUSHES IN...BUT IF
NOTHING DEVELOPS WE MAY NOT SEE MUCH PERSIST PAST 8 OR 9 PM. GIVEN
THE STRENGTH OF THE FORCING...ITS PLAUSIBLE WE COULD SEE ISOLATED
SHOWERS AHEAD OF THE FRONT THROUGH MOST OF THE NIGHT REGARDLESS.
HIGH PRESSURE IN WAKE OF THE FRONT WILL OVERSPREAD THE REGION
TOMORROW KEEPING THINGS DRY THROUGH THE MIDDLE OF THE WEEK. TEMPS
THROUGH THIS TIME WILL BE MUCH MORE SEASONAL ALTHOUGH HIGHS WILL
STILL BE COMING IN A TAD ABOVE NORMAL. RELEVANT SECTIONS OF THE
PREVIOUS LONGER TERM DISCUSSION HAVE BEEN APPENDED BELOW. /BK/
.LONG TERM...
BY WED...A VIGOROUS H5 S/WV TROUGH WILL PIVOT INTO THE CNTRL PLAINS.
DEEP SFC CYCLOGENESIS IS PROGGED TO OCCUR WITH A SUB 995MB SFC LOW
ACROSS MID/UPPER MS VALLEY THAT WILL BRING A POTENT COLD FRONT
TOWARDS THE REGION. AHEAD OF THE FRONT...PWATS WILL SURGE FROM S/SW
FLOW LATE WED/ERLY THURS TO NEAR 1.6-1.8" AS SFC DEWPOINTS CLIMB BACK
INTO THE LOW 60S.
ATTM...TIMING OF FROPA IS THURS MRNG PER 00Z EC/GFS WITH LOW
INSTABILITY BUT MODEST KINEMATICS. WILL HAVE TO KEEP WATCH OF THIS
SYSTEM IF SLOWER TIMING /AS 12Z ECMWF HINTED AT/ RESULTS IN GREATER
CONVECTIVE POTENTIAL IF FROPA OCCURS THURS AFTN. INCREASED POPS
ABOVE MEXMOS TOWARDS ECMEX VALUES THURS MRNG FOR NW AREAS WITH
DECREASING RAIN CHANCES BY THURS AFTN/NGT FROM NW TO SE. EC/GFS ARE
AT ODDS WITH DEGREE OF CAA AS EC KEEPS COOLER H85 TEMPS N/W OF
REGION WHILE GFS BARRELS SINGLE DIGIT H85 TEMPS ACROSS NRN ARKLAMISS
FRIDAY. HAVE FAVORED GFS GIVEN CONTINUED MEAN ENSEMBLE SUPPORT WITH
MEAN H5 TROUGH AXIS PLACEMENT JUXTAPOSED TO EC`S LONG RANGE H5
OMEGA BLOCK PATTERN. HIGHS FRI/SAT LOOK TO RANGE FROM NEAR 70 NORTH
TO MID 70S SOUTH WITH A SLIGHT WARM UP INTO SUNDAY WITH PROGGED
AMPLE SUNSHINE POST FROPA. /ALLEN/
&&
.AVIATION...THE CONVECTION ACROSS THE AREA THIS MORNING STABILIZED
THE AIRMASS BUT ADDITIONAL ACTIVITY WILL BE POSSIBLE ALONG A COLD
FRONT THAT WILL MOVE ACROSS THE AREA TONIGHT. EXPECT VFR CONDITIONS
OUTSIDE OF ANY TSTM ACTIVITY. THE COLD FRONT WILL PASS THROUGH THE
ENTIRE AREA BY DAYBREAK MONDAY AND EXPECT VFR CONDITIONS WILL
PREVAIL FOR THE ENTIRE AREA THROUGH MONDAY NIGHT AS HIGH PRESSURE
AND DRIER AIR BRINGS CLEAR SKIES. /22/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 57 79 49 78 / 23 0 0 5
MERIDIAN 59 80 45 77 / 23 0 0 3
VICKSBURG 53 80 46 78 / 27 0 0 5
HATTIESBURG 65 82 49 79 / 22 0 0 11
NATCHEZ 57 78 49 77 / 24 0 0 5
GREENVILLE 52 77 50 79 / 30 0 0 3
GREENWOOD 51 77 47 79 / 31 0 0 3
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...WIND ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR MSZ018-019-034.
LA...NONE.
AR...WIND ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR ARZ075.
&&
$$
BK/22/ALLEN
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
307 PM CDT SUN OCT 14 2012
.SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT
307 PM CDT SUN OCT 14 2012
BIGGEST FORECAST CHALLENGES ARE ON THE TIMING OF THE ENDING OF THE
PRECIPITATION TONIGHT ALONG WITH CLOUD TRENDS. ALSO RAIN CHANCES ON
WEDNESDAY.
18Z SURFACE ANALYSIS SHOWS AN AREA OF LOW PRESSURE OVER NORTHERN
ILLINOIS...WITH RADAR SHOWING A DEFORMATION BAND OF RAIN OVER
SOUTHERN AND CENTRAL WISCONSIN AND NORTHERN ILLINOIS. THE BACK EDGE
HAS STEADILY BEEN MOVING EASTWARD AND NOW EXTENDS FROM AROUND
NEILLSVILLE WISCONSIN...TO MONONA IOWA. VISIBLE SATELLITE IMAGERY
SHOWING BACK EDGE OF CLOUDS PUSHING INTO EASTERN MINNESOTA...WITH A
BATCH OF MID LEVEL CLOUDS OVER NORTHERN MINNESOTA.
14.12Z MODELS OFFER SIMILAR SOLUTIONS THROUGH THE PERIOD. IN THE
NEAR TERM...SURFACE LOW WILL CONTINUE TO PULL NORTHEAST INTO LOWER
MICHIGAN THIS EVENING. DEFORMATION AREA OF RAIN WILL CONTINUE TO
SHIFT EASTWARD. THE 14.12Z RAP AND 14.12Z GFS PUSH THE PRECIPITATION
TO THE EAST OF THE AREA BY 00Z...WHILE THE NAM IS A LITTLE SLOWER.
BASED ON MOVEMENT OF THE BACK EDGE...BELIEVE IT WILL CLEAR THE
FORECAST AREA BY 00Z. QUESTION THEN BECOMES HOW QUICKLY THE SKIES
CLEAR. BOTH THE NAM AND GFS RELATIVE HUMIDITY PROGS SHOW THE LOWER
STRATUS TO ADVECT EASTWARD THIS EVENING...BUT SOME MID LEVEL MOISTURE
AROUND 700MB ROTATES SOUTHWARD FROM NORTHERN MINNESOTA INTO THE
AREA. VISIBLE SATELLITE IMAGERY SHOWS THIS MOISTURE NOW OVER NORTHERN
MINNESOTA. THUS DID ADD DOME MORE CLOUDS TO THE EVENING HOURS BEFORE
CLEARING AFTER MIDNIGHT. BETWEEN THE CLOUDS AND THE PRESSURE
GRADIENT REMAINING TIGHT DO NOT EXPECT ANY FOG FORMATION DESPITE THE WET
GROUND FROM THE RAIN.
SURFACE HIGH PRESSURE BUILDS IN MONDAY...WITH THE RIDGE AXIS
QUICKLY MOVING EAST MONDAY NIGHT. 850MB TEMPERATURES IN THE 5 TO 7
DEGREE RANGE CELSIUS AND PLENTY OF SUN WILL MAKE FOR TEMPERATURES
NEAR THE SEASONAL NORMALS. WARM ADVECTION SPREADS ACROSS THE AREA ON
THE BACK SIDE OF THE HIGH MONDAY NIGHT AS A A WEAK SHORTWAVE DROPS
ACROSS THE PLAINS. FORCING SIGNALS RATHER WEAK AND FEEL BEST CHANCES
FOR PRECIPITATION WILL BE ACROSS THE FAR NORTH.
WARM ADVECTION CONTINUES IN EARNEST ON TUESDAY AS 850MB TEMPERATURES
RISE INTO THE LOWER TEENS CELSIUS. WITH A SOUTHWESTER LOW LEVEL
FLOW...EXPECT TEMPERATURES TO TOP OFF IN THE 60S TO LOWER 70S. A
SHORTWAVE WILL TRANSLATE ALONG THE CANADIAN BORDER WITH SOME WEAK
FORCING ACROSS NORTHERN WISCONSIN. GFS AND ECMWF DO GENERATE SOME
LIGHT QPF ACROSS THE FAR NORTHERN COUNTIES...WHILE NAM IS RELATIVELY
DRY. DID KEEP THE LOWER END PROBABILITIES FOR THIS TIME FRAME.
ON WEDNESDAY...A 130 KNOT 300MB JET DIGS DOWN ACROSS THE ROCKIES
INTO THE PLAINS. IN RESPONSE A STRENGTHENING 500MB CLOSED LOW WILL
DROP SOUTHWARD TO NEAR LAKE WINNIPEG. THIS AMPLIFIED FLOW WILL PUSH
A COLD FRONT ACROSS THE AREA...WITH RATHER IMPRESSIVE COLD ADVECTION
IN ITS WAKE. STRONG DYNAMIC FORCING WITH FGEN SIGNAL PUSHES ACROSS
THE AREA. MODELS CONSISTENT WITH PUSHING A BAND OF PRECIPITATION
ACROSS THE AREA WEDNESDAY. SOME WEAK INSTABILITIES LOOK TO BE
PRESENT ACROSS IOWA AND SOUTHWEST WISCONSIN. DID RAISE PROBABILITIES
IN THIS TIME FRAME AND KEPT THE MENTION OF THUNDER ACROSS THE SOUTH.
THESE PRECIPITATION CHANCES WILL REMAIN WEDNESDAY NIGHT AS 500MB
CLOSED LOW SLOWLY CONTINUES TO SINK SOUTHWARD INTO THE AREA.
.LONG TERM...THURSDAY THROUGH SUNDAY
307 PM CDT SUN OCT 14 2012
THE AFOREMENTIONED 500MB LOW WILL BE THE MAIN WEATHER FEATURE OF
INTEREST AT LEAST THROUGH THE EARLY PORTIONS OF THE WEEKEND. ONCE
AGAIN THE 14.12Z GFS IS FASTER AT OPENING THE WAVE UP AND PUSHING IT
EASTWARD ON SATURDAY...WHILE THE ECMWF MAINTAINS ITS CONTINUITY IN
SLOWLY LIFTING IT NORTHEAST LATER IN THE WEEKEND. GIVEN STRENGTH OF
SYSTEM THE SLOWER SOLUTIONS LOOKS MORE REASONABLE AT THIS POINT. WILL
CONTINUE TO SEE RAIN CHANCES THROUGH THE ENTIRE PERIOD. TEMPERATURES
LOOK TO BE BELOW NORMAL...WITH SLOW WARMING TREND BY SUNDAY AS THE
LOW PUSHES AWAY. WILL HAVE TO WAIT FOR LATER MODEL RUNS TO PIN DOWN
ANY OF THE DETAILS.
&&
.AVIATION...THROUGH 18Z MONDAY
1257 PM CDT SUN OCT 14 2012
LOW PRESSURE WILL CONTINUE TO MOVE NORTHEAST AWAY FROM THE AREA
THIS AFTERNOON. AS THIS OCCURS...THE LIGHT RAIN WILL MOVE OUT KLSE
BY 14.20Z. IN ADDITION...THE CEILINGS WILL SLOWLY RISE AND BECOME
VFR BETWEEN 14.20Z AND 15.01Z. WHILE THE AREA WILL BE LOSING THE
LOW DECK OF CLOUDS...A MID DECK OF CLOUDS WILL MOVE THROUGH THE
AREA TONIGHT...AND THEN SKIES WILL CLEAR AS A WEAK RIDGE BUILDS
ACROSS THE REGION.
WITH ALL OF THE RAIN THIS WEEKEND WAS INITIALLY CONCERNED WITH FOG
TONIGHT...HOWEVER...THE MODEL SOUNDINGS SUGGEST THAT THE WINDS
WILL STAY ABOVE 5 KNOTS. THIS WILL PRECLUDE ANY FOG DEVELOPMENT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
307 PM CDT SUN OCT 14 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RABERDING
LONG TERM...RABERDING
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1257 PM CDT SUN OCT 14 2012
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
258 AM CDT SUN OCT 14 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION TODAY AS WELL AS
PRECIPITATION CHANCES FOR MONDAY NIGHT THROUGH TUESDAY NIGHT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING BUILDING UP ACROSS THE WESTERN U.S. INTO BRITISH
COLUMBIA...A NORTHERN STREAM TROUGH OVER SOUTH CENTRAL CANADA AND
NORTH DAKOTA...AND AN UPPER LOW NEAR TOPEKA KS. ALSO OF INTEREST IS
120KT JET STREAK AROUND 200MB OVER LAKE SUPERIOR ACCORDING TO THE
RAP. THE COMBINATION OF UPPER DIVERGENCE IN THE RIGHT ENTRANCE
REGION OF THIS UPPER JET...THE PRESENCE OF LOW TO MID LEVEL
FRONTOGENESIS OVER THE SOUTHERN HALF OF THE FORECAST AREA SEEN JUST
BY CONVERGENCE IN 850MB PROFILER AND VWP DATA...AND PLENTIFUL
MOISTURE NOTED BY GOES PRECIPITABLE WATER VALUES OF 1.4 INCHES IN
THE SAME PLACE IS RESULTING IN A BAND OF SHOWERS AND EMBEDDED
THUNDERSTORMS. BACK EDGE OF THIS PRECIPITATION ALONG A LINE
EXTENDED FROM CHARLES CITY TO VIROQUA AND WISCONSIN DELLS.
NORTHWEST OF THIS LINE...PRECIPITABLE WATER VALUES DROP OFF
DRAMATICALLY... DOWN TO AROUND 0.75 INCH IN WEST CENTRAL MINNESOTA.
IN FACT...SATELLITE IMAGERY DEPICTS CLEARING OVER WESTERN
MINNESOTA AND THE EASTERN DAKOTAS. AT THE SURFACE...A 998MB LOW
WAS PRESENT IN SOUTHWEST IOWA WITH A WARM FRONT EXTENDING
NORTHEAST INTO SOUTHWEST WISCONSIN.
TODAY...MODELS DEPICT THE NORTHERN STREAM TROUGH OVER SOUTH CENTRAL
CANADA DROPPING DOWN INTO MINNESOTA AND IOWA...WHICH HELPS TO KICK
THE UPPER LOW NEAR TOPEKA NORTHEASTWARD. BY 00Z...MODELS HAVE THE
UPPER LOW AND THE ASSOCIATED SURFACE LOW IN CENTRAL LAKE MICHIGAN...
SLIGHTLY SLOWER THAN SEEN YESTERDAY. THE FORECAST AREA...IN
PARTICULAR THE SOUTHEAST HALF...WILL STAY IN THE DEFORMATION ON THE
NORTHWEST SIDE OF THE LOW TRACK WHICH IS QUITE FAVORABLE FOR
PRECIPITATION. IN FACT...THE CURRENT BAND OF SHOWERS AND EMBEDDED
THUNDERSTORMS SHOULD INTENSIFY THIS MORNING AS DPVA INCREASES FROM
THE APPROACHING UPPER LOW. FRONTOGENESIS FIELDS ALSO STRENGTHEN IN
RESPONSE TO THE INCREASING DPVA. PRECIPITATION WILL TAPER OFF IN THE
AFTERNOON WEST TO EAST AS THE UPPER JET...FRONTOGENESIS AND THE
OVERALL SYSTEM MOVE EAST AWAY FROM THE AREA. DECENT AMOUNT OF QPF
EXPECTED TODAY IN SOUTHEAST SECTIONS OF THE FORECAST AREA GIVEN
THE STRONG FORCING THIS MORNING AND PRECIPITABLE WATER VALUES NEAR
1.5 INCHES. BLEND OF GUIDANCE SUGGESTS UPWARDS OF 1 INCH BETWEEN
12-18Z FROM OELWEIN TO PRAIRIE DU CHIEN AND BOSCOBEL. ALTHOUGH
CLEARING IS NOT TOO FAR AWAY...OVER WESTERN MINNESOTA...14.00Z
NAM/14.03Z RAP SOUNDINGS SUGGEST IT WILL TAKE ITS TIME SHIFTING
EAST AS MOISTURE STAYS TRAPPED BELOW A SUBSIDENCE INVERSION AT
5000 FT. WILL PLAY THIS MORE PESSIMISTIC ROUTE COMPARED TO THE
QUICKER CLEARING GFS GIVEN THAT CLIMATOLOGICALLY CLOUD COVER TENDS
TO HOLD AROUND LONGER. WITH PLENTY OF CLOUDS AND 850MB TEMPS
FALLING FROM 8-12C AT 12Z TO 2-4C AT 00Z...ANTICIPATE TEMPERATURES
TO NOT RISE MUCH. IN FACT...READINGS COULD FALL...ESPECIALLY OVER
THE EASTERN TWO THIRDS OF THE AREA WHICH STAND NO CHANCE OF SEEING
SUN.
TONIGHT AND MONDAY...RAPID EVOLUTION OF THE UPPER AIR PATTERN IS
FORECAST OVER THE AREA DURING THIS TIME. THE NORTHERN STREAM TROUGH
DROPPING INTO IOWA AT 00Z IS PROGGED TO DIG INTO ILLINOIS BY 12Z...
THEN RIDGING SEEN OVER BRITISH COLUMBIA RIGHT NOW EXPECTED TO SHIFT
OVER THE AREA BY 00Z TUESDAY. NOT ANTICIPATING ANY PRECIPITATION
WITH THE NORTHERN STREAM TROUGH...NOR WITH THE WARM ADVECTION
ACCOMPANYING THE UPPER RIDGE BUILDING IN ON MONDAY...AS TOO MUCH
SUBSIDENCE AND DRYING FLOWS IN BEHIND THE CURRENT STORM SYSTEM.
WOULD HAVE SOME CONCERN ABOUT VALLEY FOG TONIGHT WITH SKIES LIKELY
TO CLEAR FROM WEST TO EAST AND LINGERING MOISTURE FROM TODAYS RAIN.
HOWEVER...THERE IS TOO MUCH OF A NORTHWEST BREEZE BETWEEN THE
DEPARTING STORM SYSTEM AND A SURFACE HIGH PRESSURE RIDGE BUILDING
INTO WESTERN MINNESOTA BY 12Z. THIS BREEZE SHOULD HELP KEEP
TEMPERATURES FROM DROPPING TOO MUCH AS WELL. GENERALLY FOLLOWED A
BLEND OF GUIDANCE FOR LOWS. WITH THE PASSAGE OF THE SURFACE RIDGE ON
MONDAY...MORE SUN AND 850MB TEMPS CLIMBING TO 4C EAST TO 7C WEST BY
00Z...SHOULD SEE A WARMER DAY. THE AFOREMENTIONED LATE IN THE DAY
850MB TEMPS SUPPORT HIGHS IN THE MID 50S TO LOWER 60S. THESE ARE
LOWER THAN PREVIOUSLY FORECAST BECAUSE MODELS ARE SLOWER IN BRINGING
THE WARMER AIR IN.
MONDAY NIGHT AND TUESDAY...MODELS DEPICT A SHORTWAVE TROUGH OVER
NORTH DAKOTA AT 00Z TUESDAY...PARTLY RESPONSIBLE FOR THE UPPER RIDGE
THAT MOVED INTO THE AREA ON MONDAY...MOVING QUICKLY TO THE EAST
AND PERHAPS EVEN WEAKENING. THIS WEAKENING MAKES SENSE AS THERE IS A
MUCH MORE IMPRESSIVE AND POTENT UPPER TROUGH DIGGING DOWN INTO THE
NORTHERN U.S. ROCKIES. QUESTION IS IF ANY PRECIPITATION WILL OCCUR
WITH THAT SHORTWAVE TROUGH THAT TRACKS TO OUR NORTH. 14.00Z NAM
KEEPS ALL PRECIPITATION WELL TO THE NORTH...FROM NORTHERN MINNESOTA
INTO THE U.P.. THE 14.00Z GFS SHOWS SOME PRECIP CROSSING THE
NORTHERN SECTIONS OF THE FORECAST AREA...THOUGH VARIOUS ISENTROPIC
LIFT LEVELS FROM 290-310K SHOW VERY LITTLE LIFT OCCURRING WITH IT.
PLUS...THE PRECIPITATION IS FALLING OUT OF A 9000 FT CEILING. ALL
MODELS HAVE CERTAINLY TRENDED DRIER AND LESS IMPRESSIVE WITH THE
SHORTWAVE TROUGH. HAVE DECIDED TO MAINTAIN SOME 20 PERCENT
CHANCES...MAINLY ON TUESDAY NORTHEAST OF I-94. IDEA HERE BEING THAT
IT MAY TAKE AWHILE TO SATURATE THE LOWER LEVELS WITH THE WARM
ADVECTION TO ALLOW PRECIPITATION TO OCCUR. ALTHOUGH WE MAY GET
LITTLE PRECIPITATION OVERALL WITH THE SHORTWAVE TROUGH...THERE IS
DEFINITE WARMING COMING INTO THE FORECAST AREA WITH IT. 850MB TEMPS
CLIMB TO AT LEAST 10-14C BY 18Z TUESDAY. WITH POTENTIAL FOR ANY WARM
ADVECTION MID CLOUDS TO CLEAR OUT ON TUESDAY...COULD SEE DECENT
MIXING. AS SUCH...HAVE BUMPED UP TEMPERATURES ABOUT 5 DEGREES TO
COME IN BETTER ALIGNMENT WITH GUIDANCE. MONDAY NIGHT STILL LOOKS
RELATIVELY MILD THANKS TO THE INCREASE IN MID CLOUDS AND SOME
SOUTHERLY BREEZE.
TUESDAY NIGHT...THE POTENT TROUGH DIGGING INTO THE NORTHERN ROCKIES
ON TUESDAY IS PROGGED TO DIVE DOWN INTO THE DAKOTAS. IMPRESSIVE
WINDY AND COLD ADVECTION SETUP BEHIND IT WITH MODEL PROGS OF A 980S
MB LOW NEAR LAKE WINNIPEG AND 1025-1030MB SURFACE HIGH OVER THE
NORTHWESTERN U.S.. FOR OUR AREA...WE ARE IN THE WARM ADVECTION SETUP
AHEAD OF THE LOW WITH INDICATIONS OF 500MB HEIGHTS FALLING AFTER
MIDNIGHT. THEREFORE...ANTICIPATING SOME MID AND HIGH CLOUDS
SPREADING WEST TO EAST AGAIN...LIKE MONDAY NIGHT. LOWER LEVEL
SATURATION BECOMES AN ISSUE FOR ANY PRECIPITATION TO FALL OUT OF
THESE CLOUDS. BOTH THE 14.00Z GFS AND NAM SUGGEST SOME LIGHT QPF CAN
FALL ACROSS NORTHWEST SECTIONS OF THE FORECAST AREA BETWEEN 06-12Z
WEDNESDAY...WHICH HAVE BEEN ACKNOWLEDGED WITH A 15-20 PERCENT
CHANCE. OTHERWISE...DRY CONDITIONS WITH A LIGHT SOUTHERLY BREEZE
WILL BE THE RULE. COMBINATION OF THAT SOUTHERLY BREEZE AND
CLOUDS...ALONG WITH DEWPOINTS WHICH SHOULD BE UP IN THE 40S IS
EXPECTED TO HELP HOLD LOWS UP IN THE MID 40S TO LOW 50S.
.LONG TERM...WEDNESDAY THROUGH SATURDAY NIGHT
258 AM CDT SUN OCT 14 2012
MAIN STORY FOR THE EXTENDED REVOLVES AROUND THAT POTENT UPPER TROUGH
DROPPING DOWN INTO THE DAKOTAS TUESDAY NIGHT. 14.00Z
ECMWF/GFS/CANADIAN AND GFS ENSEMBLES ALL SHOW THIS TROUGH DIGGING
INTO THE UPPER MISSISSIPPI RIVER VALLEY AND EASTERN MISSOURI RIVER V
REGIONS BY 12Z THURSDAY. AS THIS TROUGH DIGS...IT GRADUALLY PULLS UP
MORE AND MORE MOISTURE FROM THE GULF OF MEXICO. THEREFORE...
PRECIPITATION WITH IT SEEMS LIKELY. BIGGEST PROBLEM IS EVOLUTION OF
THE VARIOUS WARM AND COLD CONVEYOR BELTS AS THIS SYSTEM WRAPS
UP...WITH POTENTIAL OF A DRY SLOT COMING AROUND THE UPPER LOW TOO.
FOLLOWED THE CONSENSUS APPROACH FOR NOW WHICH INCREASES CHANCES TO
AROUND 50 ON WEDNESDAY...WITH THE EXPECTED WARM CONVEYOR BELT...
LOWER 30-40 PERCENT CHANCES ON WEDNESDAY NIGHT WITH A POSSIBLE DRY
SLOT...THEN 50 PERCENT CHANCES OVER MINNESOTA WITH THE COLD CONVEYOR
BELT TO 30 PERCENT CHANCES IN SOUTHEAST SECTIONS OF THE FORECAST
AREA WITH POSSIBLE DRY SLOT ON THURSDAY. AS TIME GETS CLOSER...THESE
CHANCES WILL NEED TO BE FURTHER REFINED WITH INCREASES AGAIN LIKELY.
WEDNESDAY STILL LOOKS RELATIVELY WARM BEING IN THE WARM CONVEYOR
BELT AND 850MB TEMPS UPWARDS OF 8-12C. MOST LOCATIONS SHOULD REACH
THE MID 50S TO MID 60S RANGE...WARMEST EAST WHERE PRECIPITATION
BEGINS LATER. COOLER WEATHER THEN ON TAP FOR THURSDAY WITH THE UPPER
TROUGH IN PLACE AND POSSIBLE PRECIPITATION. ALSO ADDED A MENTION OF
THUNDER TO NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN ON WEDNESDAY
WHERE BOTH THE 14.00Z GFS/ECMWF DEPICT SOME MUCAPE BUILDING UP.
AFTER THURSDAY...QUESTION IS HOW FAST THE UPPER LOW/TROUGH PUSHES
EAST. THE 14.00Z ECMWF/CANADIAN HAVE RIDGES AMPLIFYING ACROSS THE
WESTERN U.S. AND FROM NEW ENGLAND INTO QUEBEC...EFFECTIVELY BLOCKING
THE TROUGH FROM REALLY GOING ANYWHERE. THE 14.00Z GFS AND QUITE A
FEW OF ITS ENSEMBLE MEMBERS DO NOT HAVE AS MUCH RIDGING OVER NEW
ENGLAND AND QUEBEC...THUS ALLOWING THE TROUGH TO LIFT OUT. THINK
THIS LATTER SCENARIO IS TOO FAST AND THUS LEANING THE FORECAST MORE
TOWARDS THE CONSISTENT ECMWF/CANADIAN SOLUTIONS. THIS RESULTS IN
MAINTAINING COOL WEATHER WITH HIGHS IN THE LOW TO MID 50S ALONG WITH
LOW CHANCES OF PRECIPITATION THROUGH SATURDAY. REASON FOR THE LOW
PRECIPITATION CHANCES...GENERALLY 20-30...IS A COMBINATION OF MODEL
UNCERTAINTY ON THE EVOLUTION/TRACK OF THE UPPER LOW/TROUGH AS WELL
AS SUGGESTIONS OF THE UPPER LOW/TROUGH FILLING WITH TIME.
&&
.AVIATION...THROUGH 18Z MONDAY
1257 PM CDT SUN OCT 14 2012
LOW PRESSURE WILL CONTINUE TO MOVE NORTHEAST AWAY FROM THE AREA
THIS AFTERNOON. AS THIS OCCURS...THE LIGHT RAIN WILL MOVE OUT KLSE
BY 14.20Z. IN ADDITION...THE CEILINGS WILL SLOWLY RISE AND BECOME
VFR BETWEEN 14.20Z AND 15.01Z. WHILE THE AREA WILL BE LOSING THE
LOW DECK OF CLOUDS...A MID DECK OF CLOUDS WILL MOVE THROUGH THE
AREA TONIGHT...AND THEN SKIES WILL CLEAR AS A WEAK RIDGE BUILDS
ACROSS THE REGION.
WITH ALL OF THE RAIN THIS WEEKEND WAS INITIALLY CONCERNED WITH FOG
TONIGHT...HOWEVER...THE MODEL SOUNDINGS SUGGEST THAT THE WINDS
WILL STAY ABOVE 5 KNOTS. THIS WILL PRECLUDE ANY FOG DEVELOPMENT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
258 AM CDT SUN OCT 14 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BOYNE