Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 10/17/12
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
936 PM MDT TUE OCT 16 2012
.UPDATE...COLD FRONT CURRENTLY RACING DOWN NORTH CENTRAL AND
NORTHEASTERN COLORADO WITH NORTHWEST WINDS GUSTING TO 50 MPH AT
TIMES. THE FRONT IS HELPING ENHANCE SHOWER ACTIVITY WITH A FEW
THUNDERSTORMS OVER THE HIGH TERRAIN. NOT MUCH RAIN IS FALLING
FROM THE SHOWERS OVER THE PLAINS...MOST OF THE PRECIPITATION IS
STICKING IN THE MOUNTAINS WITH RAIN IN THE VALLEYS AND UP TO ABOUT
10 THOUSAND FEET...WITH SNOW FALLING ABOVE THAT. A FEW HIGH
MOUNTAIN LOCATIONS COULD SEE A FEW INCHES AS THIS MAIN BAND MOVES
SOUTH. HAVE INCREASED POPS FOR THIS FIRST PART OF THE NIGHT...AND
HAVE MOVED THE SYSTEM SOUTH QUICKER AND DECREASED POPS FOR THE
SECOND PART OF THE NIGHT PER SATELLITE...RADAR AND OBSERVATIONS.
WINDS IN THE FOOTHILLS WERE GUSTING BETWEEN 50 AND 60 MPH...WITH A
FEW HIGHER GUSTS AS THIS FRONT IS PUSHING THROUGH. GUSTS UP TO 75
MPH ARE NO LONGER EXPECTED AND THEREFORE HAVE CANCELLED THE HIGH
WIND WARNING FOR THE NORTHERN FOOTHILLS.
&&
.AVIATION...COLD FRONT CURRENTLY PUSHING THROUGH KDEN AND KBJC.
HAVE ADDED GUSTS UP TO 40 KTS AS UPSTREAM OBS HAVE GUSTED BETWEEN
38 AND 44 KTS. EXPECT THESE STRONG FRONTAL WINDS TO LAST ABOUT AN
HOUR TO AN HOUR AND A HALF...THEN SLIGHTLY WEAKEN BUT KEEP GUSTY
OUT OF THE NORTHWEST. A FEW SHOWERS WILL BE AROUND THE AREA AS THE
FRONT PASSES...BUT LITTLE TO NO RAIN IS EXPECTED WITH CEILINGS
STAYING ABOVE 8K FEET. NORTHWEST WINDS TO PREVAIL AFTER 18Z WITH
SOME GUSTS TO 30 KTS POSSIBLE AT DIA. STRONGEST WINDS SHOULD STAY
TO THE NORTHEAST OF DENVER.
&&
.PREV DISCUSSION... /ISSUED 329 PM MDT TUE OCT 16 2012/
SHORT TERM...NOSE OF 150 KT JET MOVING ACROSS NORTHERN GREAT
BASIN IN STRONG NORTHWEST FLOW ALOFT. THE STRONG WINDS HAVE BEEN
RATHER SLOW TO DEVELOP ALONG NORTHERN FOOTHILLS. BUT SOME HOPE AS
LATEST RUC AND NAM CROSS SECTIONS INDICATING 50 KT WINDS ACROSS
THE MOUNTAINS AND HIGHER FOOTHILLS BY 00Z. SO WILL CONTINUE TO
HOLD ONTO THE HIGH WIND WARNING FOR ZONE 35 THROUGH MIDNIGHT.
MODELS SHOW MOISTURE AND MID LEVEL QG ASCENT INCREASING ACROSS
MOUNTAINS AFTER 00Z AS MID LEVEL SHORTWAVE MOVES ACROSS WYOMING.
APPEARS THAT THERE WILL BE A WINDOW IN THE 03-09Z TIME FRAME OF
GOOD LIFT AND OROGRAPHICS FOR SOME SNOWFALL OVER THE HIGH COUNTRY.
STILL LOOKING LIKE ABOUT 3 INCHES COULD OCCUR BY THE END OF THIS
PERIOD BEFORE SUBSIDENCE DOMINATES. COULD ALSO BE SOME BLOWING
SNOW BUT WILL HOLD OFF FOR NOW. BY ACROSS PLAINS...WAVE TO PUSH
FRONT ACROSS PLAINS OVERNIGHT. MODELS SHOW WINDS BECOMING
NORTHWEST AFTER MIDNIGHT. AIRMASS TO REMAIN DRY WITH INCREASING
MID AND HIGH LEVEL MOISTURE. ON WEDNESDAY...STRONG NORTHWEST FLOW
TO CONTINUE WITH SUBSIDENCE AND DRY AIR SPREADING ACROSS
MOUNTAINS. WINDS TO REMAIN GUSTY OVER MOUNTAINS AND ALONG
FOOTHILLS. HOWEVER...LATEST CROSS SECTIONS DO NOT SHOW A FAVORABLE
WIND SETUP FOR HIGH WINDS...WITH NAM INDICATING CROSS MOUNTAIN
COMPONENT OF AROUND 50 KTS OVER THE HIGHER MOUNTAINS DURING THE
AFTERNOON. BUT THE INCREASING SUBSIDENCE COULD HELP TRANSPORT THE
STRONGER WINDS ACROSS THE FOOTHILLS. WILL HOLD OFF ON A HIGH WIND
WATCH AT THIS POINT. COULD SEE SOME GUSTS APPROACHING 70 MPH OVER
THE RIDGES AND 60 MPH ALONG THE NORTHERN FOOTHILLS. ACROSS
PLAINS...FRONT TO PUSH ACROSS AREA DURING THE EARLY MORNING...WITH
SOME HINTS OF A NORTHERLY COMPONENT AROUND 14Z. WITH MID LEVEL QG
ASCENT OVER AREA...A FEW SHOWERS COULD BE GENERATED...MAINLY
NORTH AND EAST OF DENVER. BY 18Z SHORTWAVE FRONT TO BE EAST OF THE
AREA...WITH NORTHWEST WINDS DEVELOPING. PATTERN APPEARS TO BE A
BORA TYPE PATTERN WITH THE SUBSIDENCE AND STRONGER WINDS BEHIND
THE EXITING FRONT. SHOULD SEE WINDS INCREASE ACROSS THE AREA
DURING THE AFTERNOON AS THE GRADIENT INCREASES...ESPECIALLY ALONG
THE WYOMING AND NEBRASKA WHERE SOME GUSTS COULD EXCEED 55 MPH.
WILL ISSUE A HIGH WIND WATCH FOR ZONES 42..48..50 AND 51 FOR THE
AFTERNOON. DESPITE THE COOLER AIRMASS...SHOULD SEE HUMIDITY IN THE
LOWER TEENS DURING THE AFTERNOON ALONG WITH THE GUSTY WINDS. WILL
UPGRADE THE FIRE WEATHER WATCH TO A RED FLAG WARNING.
LONG TERM...FOR WEDNESDAY NIGHT AND THURSDAY...A STRONG
NORTHWESTERLY FLOW ALOFT WILL CONTINUE OVER THE REGION WITH THE
120+ KT UPPER LEVEL JET STRETCHING ACROSS EASTERN WYOMING...
NORTHEAST COLORADO AND INTO KANSAS AND OKLAHOMA THURSDAY MORNING.
ALTHOUGH THE SURFACE PRESSURE GRADIENT WILL NOT BE AS STRONG...THE
GUSTY WINDS WILL LIKELY REDEVELOP ONCE THE STRONGER WINDS ALOFT MIX
INTO THE BOUNDARY LAYER. THE WIND WILL BE STRONGEST IN THE
VICINITY OF THE UPPER JET. THE BEST COMBINATION OF LOW RELATIVE
HUMIDITIES AND STRONG WINDS WILL BE NEAR THE NEBRASKA AND KANSAS
BORDERS. AS A RESULT THE FIRE DANGER WILL AGAIN BE ELEVATED. SINCE
WE ALREADY HAVE A RED FLAG WARNING IN EFFECT FOR WEDNESDAY...WILL
HOLD OFF ON ISSUING A FIRE WEATHER WATCH AT THIS TIME. THE FLOW
ALOFT WILL CONTINUE TO LESSEN ON FRIDAY AS AN UPPER LEVEL RIDGE
BUILDS IN FROM THE WEST. ALTHOUGH IT WILL BE WINDY AT TIMES...THE
MAGNITUDE WILL BE LOWER AND DURATION SHORTER FOR THE STRONGER
WINDS. DRY AND WARMER CONDITIONS WILL OCCUR OVER THE WEEKEND WITH
THE FLOW ALOFT MORE WESTERLY AS THE RIDGE AXIS SHIFTS OVER THE
STATE. THE LATEST MDLS RUNS ARE DRIER AND MORE INCONSISTENT FOR
THE NEXT POTENTIAL STORM NEXT WEEK. FOR NOW WILL CONFINE ANY
MENTION OF PRECIPITATION TO THE HIGH COUNTRY...AND THE MODIFY OR
INCREASE THE FORECAST MAX TEMPERATURES FOR MONDAY AND TUESDAY AS
WELL.
AVIATION...WEST SOUTHWEST WINDS FINALLY DEVELOPED ACROSS AREA AIRPORTS
WITH SOME GUSTS TO 25 KTS WHICH SHOULD CONTINUE THOUGH 02Z BEFORE
DECREASING AND BECOMING MORE SOUTHWEST. WEAK FRONT TO MOVE ACROSS
THE AREA AROUND 07Z WITH WINDS SHIFTING TO THE NORTHWEST. MODELS
CONTINUE TO SHOW WINDS BECOMING NORTH AROUND 14Z. BUT FRONT TO BE
DRY SO NOT EXPECTING LOW CLOUDS THOUGH CEILINGS OF AROUND 6000
FEET AGL COULD POSSIBLE BETWEEN 14Z AND 17Z. SOME RAIN SHOWERS
COULD DEVELOP NORTH AND EAST OF DENVER...SHOULD NOT AFFECT AREA
AIRPORTS. NORTHWEST WINDS TO PREVAIL AFTER 18Z WITH SOME GUSTS TO
30 KTS POSSIBLE AT DIA. STRONGEST WINDS TO BE NORTHEAST OF DENVER.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM NOON TO 6 PM MDT WEDNESDAY FOR COZ238>251.
HIGH WIND WATCH WEDNESDAY AFTERNOON FOR COZ042-048-050-051.
&&
$$
SHORT TERM...D-L
LONG TERM....COOPER
UPDATE/AVIATION...KRIEDERMAN
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1101 AM EDT MON OCT 15 2012
.SYNOPSIS...
A COLD FRONT WILL SLOWLY APPROACH THE TRI-STATE REGION THIS
AFTERNOON...AND THEN PASS TONIGHT. GUSTY WINDS WILL USHER IN A
COOLER AIRMASS FOR TUESDAY. HIGH PRESSURE WILL BUILD INTO THE
REGION TUESDAY NIGHT THROUGH THURSDAY...BEFORE MOVING EAST OF THE
AREA THURSDAY NIGHT. A STORM SYSTEM MAY IMPACT THE AREA NEXT
WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COLD FRONT WAS LOCATED OVER CENTRAL PENNSYLVANIA WITH SHOWERS
BREAKING OUT ACROSS THE MID ATLANTIC AND SE PA. RAIN WILL BEGIN TO
OVERSPREAD THE AREA BY EARLY THIS AFTERNOON AND IS IN LINE WITH
THE CURRENT FORECAST PRODUCT SUITE. JUST NEEDED TO MAKE A FEW
ADJUSTMENTS TO ACCOUNT FOR CURRENT CONDITIONS. THERE HAVE ALSO BEEN
A FEW BREAKS IN THE CLOUD DECK WITH SKIES BECOMING PARTLY SUNNY.
THIS WILL BE SHORT LIVED AS THE THE RAIN SHIELD EXPANDS TO THE NE
IN RESPONSE TO A DIGGING UPPER TROF OVER THE OH AND TN VALLEYS.
H3 JET WILL SLOWLY APPROACH FROM THE W TODAY. THIS WILL AID IN
THE DEVELOPMENT OF RAIN ALONG AND AHEAD OF THE FRONT. MODELS VERY
CLOSE WITH TIMING AND PLACEMENT AND A BLEND WAS USED FOR THE FCST.
MAIN BAND OF PCPN APPEARS TO COME THRU IN THE LATE AFTN AND EVE IN
ASSOCIATION WITH THE RR QUAD OF THE JET. CAPE IS WEAK AND SKINNY.
WITH STRONG WINDS IN THE MID TO UPR LVLS...EXPECT ANY UPDRAFTS TO
BE SHEARED APART. WILL THEREFORE NOT FCST TSTMS. TEMPS TODAY CLOSE
TO THE BCMAV/LAV.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
RAIN TRAVERSES THE CWA FROM W TO E TNGT. WINDS SHIFT TO THE NW
AND THE PCPN CUTS OFF AFT FROPA. FRONT AND PCPN TIMED TO CLEAR ERN
ZONES BEFORE SUNRISE TUE. TEMPS CLOSE TO THE MET WITH WINDS
STAYING UP. MAV APPEARS TOO COLD BASED ON UPSTREAM TEMPS CURRENTLY
BEING RECORDED.
SUNNY AND BREEZY ON TUE WITH A 1015 HIGH OVER THE SERN CONUS AND A
990 LOW OVER THE MARITIMES. HIGHS BLW CLIMO BY A FEW DEGREES WITH
H85 TEMPS IN THE LOW SINGLE DIGITS C.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE BUILDS INTO THE REGION TO START THE LONG TERM PERIOD
TUESDAY NIGHT. THIS HIGH IS FORECAST TO REMAIN OVER THE REGION
THROUGH THURSDAY MORNING...PROVIDING THE LOCAL AREA WITH FAIR AND DRY
CONDITIONS. A WEAK SHORTWAVE PASSING NORTH OF THE REGION COULD
PROVIDE THE AREA WITH SOME CLOUDS WEDNESDAY...OTHERWISE WE ARE
LOOKING FOR MOSTLY CLEAR CONDITIONS.
THE HIGH WILL MOVE OFF TO THE EAST THURSDAY AFTERNOON AND
EVENING...WITH THE ARRIVAL OF THE NEXT STORM SYSTEM. WITH MODEL
DISCREPANCIES...HAVE NOT MADE ANY SIGNIFICANT CHANGES TO THE
FORECAST.
THE EC/CMC MEANS ARE FURTHER S WITH THE UPPER LOW NEAR IOWA ON
THU WHILE THE GFS MEAN IS CLOSER TO LAKE SUPERIOR. THE
DETERMINISTIC MODELS SUPPORT THE SLOWER FURTHER S SOLN AND THIS
GENERAL IDEA WAS FOLLOWED ALTHOUGH HAVE NOT TOTALLY DISREGARDED
THE FASTER GFS. LONG PERIOD OF POPS STARTING THU NIGHT AND
CONTINUING RIGHT THROUGH SUN. THIS IS MAINLY DUE TO THE TIMING
DISCREPANCIES AND SHOULD NARROW IN THE COMING DAYS. HOWEVER...DUE
TO THE SLOW NATURE OF THIS SYSTEM...A SIGNIFICANT RAINFALL IS
POSSIBLE NEXT WEEKEND.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
A COLD FRONT THAT EXTENDS FROM CENTRAL NY STATE TO CENTRAL PA AS
OF 15Z WILL REACH THE NY METRO AROUND SUNSET AS IT PROGRESSES EAST
AT JUST UNDER 20 KT. HIGH PRESSURE BUILDS IN FOR TUESDAY.
MOIST S/SW FLOW AHEAD OF THE FRONT WILL ALLOW SHOWER ACTIVITY
AHEAD OF THE FRONT TO QUICKLY EXPAND NE ACROSS THE NY METRO
REGION. THERE IS UNCERTAINTY HOW FAST LOWER CIGS WILL FORM AND HOW
LOW THEY`LL GO - BUT MODERATELY CONFIDENT OF NOTHING LOWER THAN MARGINAL
VFR CIGS...THOUGH THEY COULD BE IN THE THE 1000-2000 RANGE BY LATE
AFTN.
AN ISO TSTM IS ALSO POSSIBLE DURING TEMPO PERIODS WITH OCCASIONAL HEAVY
PCPN.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: HIGH CONFIDENCE IN WND FCST. CIGS OF
1000-1500 POSSIBLE WITH BRIEF 2SM VSBY IN TEMPO PERIOD TIMES.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: HIGH CONFIDENCE IN WND FCST. OCCASIONAL
GUSTS TO 20 KT POSSIBLE INTO THE LATE AFTN. CIGS OF 1000-2000
POSSIBLE WITH BRIEF 2SM VSBY IN TEMPO PERIOD TIMES.
KLGA FCSTER COMMENTS: HIGH CONFIDENCE IN WND FCST. OCCASIONAL
GUSTS TO 20 KT POSSIBLE INTO THE LATE AFTN. CIGS OF 1500-2000
POSSIBLE WITH BRIEF 2SM VSBY IN TEMPO PERIOD TIMES.
KTEB FCSTER COMMENTS: HIGH CONFIDENCE IN WND FCST. CIGS OF
1000-1500 POSSIBLE WITH BRIEF 2SM VSBY IN TEMPO PERIOD TIMES.
KHPN FCSTER COMMENTS: BRIEF IFR POSSIBLE IN HEAVY PCPN DURING TEMPO
PERIOD TIMES.
KISP FCSTER COMMENTS: BRIEF IFR POSSIBLE IN HEAVY PCPN DURING TEMPO
PERIOD TIMES.
OUTLOOK FOR 15Z TUE THROUGH FRIDAY...
.TUESDAY...VFR. NW GUSTS AROUND 25 KT.
.WEDNESDAY-THURSDAY...VFR.
.FRIDAY...S GUSTS 20-25 KT. CHC SHRA/CIGS BLO 3KFT IN RAIN.
&&
.MARINE...
SCA CONDITIONS WILL CONTINUE TODAY ON S WINDS. WINDS WILL DECREASE
A BIT TNGT...BUT SEAS WILL REMAIN ELEVATED ON THE OCEAN. WILL
ALLOW THE SCA TO END ON THE PROTECTED WATERS THIS EVE...AND
MAINTAIN IT ON THE OCEAN. EXTENDED THE SCA ON THE OCEAN THRU TUE
WITH INCREASING NW WINDS. CONDITIONS WILL BE CLOSE TO SCA LVLS ON
THE REMAINDER OF THE WATERS...SO AN ADVY IS POSSIBLE FOR TUE.
WINDS WILL GRADUALLY FALL BELOW SCA LEVELS TUESDAY NIGHT AND
REMAIN BELOW SCA LEVELS THROUGH AT LEAST THURSDAY WITH A WEAK
PRESSURE GRADIENT ACROSS THE AREA.
WINDS INCREASE ON FRIDAY AND SHOULD REMAIN UP THROUGH THE WEEKEND AS
A STORM SYSTEM APPROACHES AND MOVES ACROSS THE AREA WATERS. QUESTION
REMAINS ON THE EXACT TIMING OF WHEN THE SMALL CRAFT ADVISORY WINDS
IMPACT THE AREA WATERS...WHICH WILL DEPEND ON HOW THE STORM SYSTEM
EVOLVES COMING OUT OF THE MID-SECTION OF THE COUNTRY.
SEAS ON THE OCEAN WATERS ARE A DIFFERENT STORY. INCREASING SWELLS
FROM RAFAEL COULD KEEP SEAS ABOVE 5 FT THROUGH THE FORECAST PERIOD.
FOR THE LATEST ON RAFAEL...PLEASE REFER TO PRODUCTS ISSUED BY THE
NATIONAL HURRICANE CENTER.
&&
.HYDROLOGY...
3/4 OF AN INCH OR LESS OF RAIN IS EXPECTED THRU TNGT. FLOODING IS
NOT EXPECTED. DRY WEATHER TUE THRU AT LEAST THU.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ330-
335-338-340-345.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...BC/JMC
NEAR TERM...JMC/DW
SHORT TERM...JMC
LONG TERM...BC
AVIATION...JC/TONGUE
MARINE...BC/JMC
HYDROLOGY...JMC
AREA FORECAST DISCUSSION
NWS NEW YORK NY
732 AM EDT MON OCT 15 2012
.SYNOPSIS...
A COLD FRONT WILL SLOWLY APPROACH THE TRI-STATE REGION TODAY...AND
PASS TONIGHT. GUSTY WINDS WILL USHER IN A COOLER AIRMASS FOR
TUESDAY. HIGH PRESSURE WILL BUILD INTO THE REGION TUESDAY NIGHT
THROUGH THURSDAY...BEFORE MOVING EAST OF THE AREA THURSDAY NIGHT.
A STORM SYSTEM MAY IMPACT THE AREA NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A COLD FRONT IS LOCATED IN WESTERN PENNSYLVANIA THIS MORNING. THE
CWA WILL REMAIN IN THE WARM SECTOR BEFORE THE FRONT ARRIVES.
CLOUDS HAVE OVERSPREAD MUCH OF THE CWA...HOWEVER IT WILL TAKE
SLIGHTLY LONGER FOR PRECIPITATION TO MOVE IN.
H3 JET WILL SLOWLY APPROACH FROM THE W TODAY. THIS WILL AID IN
THE DEVELOPMENT OF RAIN ALONG AND AHEAD OF THE FRONT. MODELS VERY
CLOSE WITH TIMING AND PLACEMENT AND A BLEND WAS USED FOR THE FCST.
MAIN BAND OF PCPN APPEARS TO COME THRU IN THE LATE AFTN AND EVE IN
ASSOCIATION WITH THE RR QUAD OF THE JET. CAPE IS WEAK AND SKINNY.
WITH STRONG WINDS IN THE MID TO UPR LVLS...EXPECT ANY UPDRAFTS TO
BE SHEARED APART. WILL THEREFORE NOT FCST TSTMS. TEMPS TODAY CLOSE
TO THE BCMAV/LAV.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
RAIN TRAVERSES THE CWA FROM W TO E TNGT. WINDS SHIFT TO THE NW
AND THE PCPN CUTS OFF AFT FROPA. FRONT AND PCPN TIMED TO CLEAR ERN
ZONES BEFORE SUNRISE TUE. TEMPS CLOSE TO THE MET WITH WINDS
STAYING UP. MAV APPEARS TOO COLD BASED ON UPSTREAM TEMPS CURRENTLY
BEING RECORDED.
SUNNY AND BREEZY ON TUE WITH A 1015 HIGH OVER THE SERN CONUS AND A
990 LOW OVER THE MARITIMES. HIGHS BLW CLIMO BY A FEW DEGREES WITH
H85 TEMPS IN THE LOW SINGLE DIGITS C.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE BUILDS INTO THE REGION TO START THE LONG TERM PERIOD
TUESDAY NIGHT. THIS HIGH IS FORECAST TO REMAIN OVER THE REGION
THROUGH THURSDAY MORNING...PROVIDING THE LOCAL AREA WITH FAIR AND DRY
CONDITIONS. A WEAK SHORTWAVE PASSING NORTH OF THE REGION COULD
PROVIDE THE AREA WITH SOME CLOUDS WEDNESDAY...OTHERWISE WE ARE
LOOKING FOR MOSTLY CLEAR CONDITIONS.
THE HIGH WILL MOVE OFF TO THE EAST THURSDAY AFTERNOON AND
EVENING...WITH THE ARRIVAL OF THE NEXT STORM SYSTEM. WITH MODEL
DISCREPANCIES...HAVE NOT MADE ANY SIGNIFICANT CHANGES TO THE
FORECAST.
THE EC/CMC MEANS ARE FURTHER S WITH THE UPPER LOW NEAR IOWA ON
THU WHILE THE GFS MEAN IS CLOSER TO LAKE SUPERIOR. THE
DETERMINISTIC MODELS SUPPORT THE SLOWER FURTHER S SOLN AND THIS
GENERAL IDEA WAS FOLLOWED ALTHOUGH HAVE NOT TOTALLY DISREGARDED
THE FASTER GFS. LONG PERIOD OF POPS STARTING THU NIGHT AND
CONTINUING RIGHT THROUGH SUN. THIS IS MAINLY DUE TO THE TIMING
DISCREPANCIES AND SHOULD NARROW IN THE COMING DAYS. HOWEVER...DUE
TO THE SLOW NATURE OF THIS SYSTEM...A SIGNIFICANT RAINFALL IS
POSSIBLE NEXT WEEKEND.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
A COLD FRONT APPROACHES FROM THE WEST TODAY BEFORE PASSING THROUGH
LATE IN THE DAY INTO THIS EVENING.
S/SW WINDS AVERAGING MOSTLY 10-15 KT WITH GUSTS AROUND 20 KT BECOME
SLIGHTLY LIGHTER THIS AFTERNOON AND LESS GUSTY. WIND SHIFT TO NW
ARRIVES CLOSE TO MIDNIGHT.
CHC CIGS PREVAIL 1500-3000 FT INSTEAD OF TEMPO. ISO TSTM IS ALSO
POSSIBLE DURING THESE TEMPO PERIODS. CHC -SHRA A COUPLE OF HOURS
BEFORE THE TIME INDICATED IN TAFS.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: OCCASIONAL GUSTS 16-20 KT THROUGH 15Z. GUSTS
MAY ALSO ONLY BE OCCASIONAL AFTER 15Z.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: OCCASIONAL GUSTS 20-24 KT THROUGH 15Z. GUSTS
MAY ALSO ONLY BE OCCASIONAL AFTER 15Z.
KLGA FCSTER COMMENTS: OCCASIONAL GUSTS AROUND 20 KT POSSIBLE THROUGH
15Z. GUSTS MAY ALSO ONLY BE OCCASIONAL AFTER 15Z.
KTEB FCSTER COMMENTS: OCCASIONAL GUSTS 16-20 KT POSSIBLE THROUGH
15Z. GUSTS MAY ALSO ONLY BE OCCASIONAL AFTER 15Z.
KHPN FCSTER COMMENTS: GUSTS MAY ONLY BE OCCASIONAL.
KISP FCSTER COMMENTS: GUSTS MAY ONLY BE OCCASIONAL AFTER 16Z.
OUTLOOK FOR 12Z TUE THROUGH FRIDAY...
.TUESDAY...VFR. NW GUSTS AROUND 25 KT.
.WEDNESDAY-THURSDAY...VFR.
.FRIDAY...S GUSTS 20-25 KT. CHC SHRA/CIGS BLO 3KFT IN RAIN.
&&
.MARINE...
SCA CONDITIONS WILL CONTINUE TODAY ON S WINDS. WINDS WILL DECREASE
A BIT TNGT...BUT SEAS WILL REMAIN ELEVATED ON THE OCEAN. WILL
ALLOW THE SCA TO END ON THE PROTECTED WATERS THIS EVE...AND
MAINTAIN IT ON THE OCEAN. EXTENDED THE SCA ON THE OCEAN THRU TUE
WITH INCREASING NW WINDS. CONDITIONS WILL BE CLOSE TO SCA LVLS ON
THE REMAINDER OF THE WATERS...SO AN ADVY IS POSSIBLE FOR TUE.
WINDS WILL GRADUALLY FALL BELOW SCA LEVELS TUESDAY NIGHT AND
REMAIN BELOW SCA LEVELS THROUGH AT LEAST THURSDAY WITH A WEAK
PRESSURE GRADIENT ACROSS THE AREA.
WINDS INCREASE ON FRIDAY AND SHOULD REMAIN UP THROUGH THE WEEKEND AS
A STORM SYSTEM APPROACHES AND MOVES ACROSS THE AREA WATERS. QUESTION
REMAINS ON THE EXACT TIMING OF WHEN THE SMALL CRAFT ADVISORY WINDS
IMPACT THE AREA WATERS...WHICH WILL DEPEND ON HOW THE STORM SYSTEM
EVOLVES COMING OUT OF THE MID-SECTION OF THE COUNTRY.
SEAS ON THE OCEAN WATERS ARE A DIFFERENT STORY. INCREASING SWELLS
FROM RAFAEL COULD KEEP SEAS ABOVE 5 FT THROUGH THE FORECAST PERIOD.
FOR THE LATEST ON RAFAEL...PLEASE REFER TO PRODUCTS ISSUED BY THE
NATIONAL HURRICANE CENTER.
&&
.HYDROLOGY...
3/4 OF AN INCH OR LESS OF RAIN IS EXPECTED THRU TNGT. FLOODING IS
NOT EXPECTED. DRY WEATHER TUE THRU AT LEAST THU.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ330-
335-338-340-345.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...BC/JMC
NEAR TERM...JMC
SHORT TERM...JMC
LONG TERM...BC
AVIATION...JC
MARINE...BC/JMC
HYDROLOGY...JMC
AREA FORECAST DISCUSSION
NWS TAUNTON MA
728 AM EDT MON OCT 15 2012
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL BRING BREEZY AND WARM WEATHER
TODAY ALONG WITH A ROUND OF SHOWERS...MAINLY LATER THIS AFTERNOON
INTO TONIGHT. DRY AND COOLER WEATHER FOLLOWS TUESDAY THEN A
WARMING TREND WEDNESDAY INTO THURSDAY. MOISTURE WILL INCREASE
ALONG WITH A CHANCE OF SHOWERS BY FRI/SAT AS A COLD FRONT
APPROACHES FROM THE WEST.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
730 AM UPDATE...
MADE MINOR UPDATES TO ACCOUNT FOR CURRENT TRENDS. TEMPS CONTINUE
TO INCREASE THIS MORNING DUE TO STRONG WAA AHEAD OF APPROACHING
COLD FRONT. INCREASED HIGH TEMPS UP A DEG OR TWO. RADAR IMAGERY
SHOWING LIGHT ECHOES ON THE SCOPE...HOWEVER THESE ARE NOT HITTING
THE GROUND AS TEMP DEWPOINT SPREAD IS TO GREAT...SO POSSIBLE VIRGA
FALLING FROM THE SKY. WINDS HAVE ALREADY STARTED TO GUSTS AND
SEEING JKF VAD PROFILER AT 50 KTS AT 925 MB BELIEVE ANOTHER WINDY
DAY IS IN STORE FOR TODAY. DID A MODEL BLEND OF THE HRRR AND
LAVRUC AS THESE MODELS HAVE BEEN PERFORMING THE BEST IN THE SHORT
TERM THIS MORNING. OTHERWISE FORECAST REMAINS ON TRACK FOR TODAY.
PREV DISCUSSION...
COLD FRONT MOVES EAST FROM THE EASTERN GT LAKES AND WILL APPROACH
WESTERN NEW ENG TOWARD EVENING. MODELS INDICATE A BAND OF DEEP
MOISTURE AND OMEGA AHEAD OF THE FRONT MOVING INTO W ZONES MID TO
LATE AFTERNOON WHICH WILL LEAD TO SHOWERS DEVELOPING. THERE IS
ALSO SOME ELEVATED INSTABILITY SO CANT RULE OUT AN ISOLD TSTM.
WE HAVE INCREASED POPS TO CATEGORICAL CT VALLEY WEST WHERE HIGHEST
PROB OF AFTERNOON SHOWERS...WITH POPS DECREASING TO THE EAST. HAVE
JUST SLIGHT CHC POPS SE MA AND THE CAPE WHERE IT SHOULD REMAIN
MOSTLY DRY TODAY. HOWEVER...AN AREA OF MOISTURE LIFTING NE FROM
THE OCEAN MAY CLIP ACK WITH A FEW SHOWERS THIS AFTERNOON.
CONFIDENCE IS LOW IN THIS OCCURRING AND ANY SHOWERS COULD REMAIN
OFFSHORE.
A RATHER MILD START TO THE DAY WITH SOME SUNSHINE POSSIBLE THIS
MORNING...ESPECIALLY E ZONES WILL LEAD TO A WARM DAY WITH MAXES
REACHING INTO THE LOWER 70S WITH UPPER 60S NW HIGHER TERRAIN. IT
WILL ALSO BE BREEZY AND HUMID WITH DEWPOINTS CLIMBING INTO THE
LOWER 60S NEAR THE COAST ALONG WITH GUSTY SW WINDS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
TONIGHT...
WIDESPREAD SHOWERS ARE EXPECTED TO MOVE EAST ACROSS SNE TONIGHT AS
THE FRONT MOVES ACROSS THE REGION AND WE HAVE CATEGORICAL POPS.
BRIEF HEAVY RAINFALL IS POSSIBLE AS THERE IS GOOD FORCING FROM
RIGHT ENTRANCE REGION OF STRONG UPPER JET AND PWATS CLIMB TO 1.5"
WHICH IS ABOUT +2SD. THE FRONT WILL BE QUICK MOVING SO DURATION OF
ANY HEAVY RAINFALL WILL BE BRIEF AND NOT LAST MORE THAN A FEW
HOURS. THE SHOWERS SHOULD BE MOVING EAST OF THE CAPE 06-09Z.
TUESDAY...
COLD FRONT WILL BE OFFSHORE WITH GUSTY NW WINDS EXPECTED. MID
LEVEL TROF WILL BE LIFTING NORTH AND EAST OF SNE DURING THE
MORNING SO EXPECT A DRY DAY ALTHOUGH DIURNAL CU WILL DEVELOP. IT
WILL BE A NOTICEABLY COOLER DAY THAN TODAY AS 850 MB TEMPS FALL TO
NEAR 0C WITH MAXES RANGING FROM LOWER 50S NW HIGHER TERRAIN TO
NEAR 60 COASTAL PLAIN.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGHLIGHTS...
* HIGH PRESSURE FOR MID-WEEK WITH MILD TEMPS.
* PERIODS OF SHOWERS POSSIBLY SOMETIME FRIDAY INTO THE WEEKEND.
DETAILS...
MODELS/PATTERN...
00Z MODELS IN GOOD AGREEMENT FOR THE MID-WEEK BEFORE DIVERGING
FRIDAY INTO THE WEEKEND. UPPER LEVEL RIDGE WILL BUILD IN ACROSS THE
FORECAST REGION BEGINNING TUESDAY NIGHT. THE 00Z ECMWF IS MORE
AMPLIFIED THEN THE GFS...NO MATTER HIGH PRESSURE WILL DOMINATE. MAIN
FOCUS FOR THE LONG TERM IS THE CUT-OFF LOW OVER THE UPPER
MISSISSIPPI VALLEY AND ITS TRENDS FOR LATE WEEK. THERE ARE 2 MAIN
CLUSTERS...THE NAM/GFS WHICH IS THE NORTHERN SOLUTION COMPARED TO
THE UKMET/ECMWF WHICH IS MORE AMPLIFIED. BECAUSE OF THE SPLIT
BETWEEN THE MODELS...CONTINUED PREV FORECAST WITH A SLIGHT TREND
TOWARDS HPC/UKMET/ECMWF. EXPECT CUT OFF LOW TO MOVE OVER NEW ENGLAND
BY FRI/SAT BEFORE EXITING THE REGION BY SUNDAY. BUILDING HIGH
PRESSURE ACROSS THE SOUTHEAST WILL BUILD A RIDGE OVER THE AREA FOR
EARLY NEXT WEEK.
MID-WEEK...HIGH CONFIDENCE
HIGH PRESSURE OVER THE MID-ATLANTIC WILL CONTINUE TO BUILD ACROSS
THE REGION STARTING LATE TUESDAY THROUGH THURSDAY. QUICK MOVING
SHORTWAVE IN THE FLOW WILL BRING SOME CLOUDS TO THE AREA ON WED.
HOWEVER AN EXCELLENT FALL LIKE DAY WITH TEMPS IN THE MID TO UPPER
60S. BELIEVE A FEW 70S MAY SNEAK OUT ACROSS THE SOUTHERN HALF OF THE
AREA...ALL DEPENDENT ON CLOUD COVER AND MIXING POTENTIAL. AS RIDGE
CONTINUE TO BUILD ACROSS THE REGION...STRONG WAA WILL OCCUR
OVERNIGHT WED INTO THURS MORNING. WENT WITH A NON-DIURNAL TREND AS
TEMPS WILL REMAIN STEADY AND/OR INCREASE OVERNIGHT.
HIGH PRESSURE WILL SLIDE SOUTHEAST OF THE CAPE AND ISLAND BY
THURSDAY SWITCHING THE WINDS TO THE SOUTHWEST. TIGHT PRESSURE
GRADIENT FROM AN APPROACHING SYSTEM OUT WEST WILL HELP AID IN GUSTY
WINDS. TEMPS ON THURSDAY MAY BE FORECASTED A TAD TOO LOW AS IT IS
DEPENDENT ON THE APPROACHING SYSTEM...IF IT AMPLIFIES MORE AND THUS
SLOW DOWN OR CONTINUE ITS CURRENT PATH. IF IT SLOWS DOWN THEN THERE
COULD BE TEMPS IN THE LOW TO MID 70S...WILL HAVE TO MONITOR AS
MODELS GET A BETTER HANDLE ON APPROACHING CUT-OFF LOW.
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
APPROACH THE REGION SOMETIME LATE IN THE WEEK. CURRENTLY THERE IS A
LARGE PLACEMENT ON THE LOWS LOCATION AS STATED EARLIER. HAVE KEPT
CURRENT FORECAST WITH A TREND TOWARDS HPC SINCE THEY COMBINED THE
ECMWF AND UKMET. CUT OFF LOW WILL BRING A COLD FRONT ACROSS THE
REGION SOMETIME FRIDAY INTO SATURDAY. RAIN MAY BE HEAVY AT TIMES AS
THERE IS PLENTY OF MOISTURE AHEAD OF THE SYSTEM. STAY TUNED TO LATER
FORECAST AS TRACK OF THE SYSTEM COULD CHANGE AS MODELS WILL NOT HAVE
A GOOD SAMPLE ON THE SYSTEM UNTIL TUESDAY...WHEN IT MOVES INTO THE
CONUS.
MODELS ARE SHOWING STRONG HIGH PRESSURE DEVELOPING ACROSS THE
SOUTHEAST AND BUILDING INTO NEW ENGLAND BY EARLY NEXT WEEK. THIS
WILL KEEP THE ABOVE AVG TREND GOING.
&&
.AVIATION /11Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
OVERVIEW...MODERATE CONFIDENCE.
ISOLD MVFR OR EVEN IFR ST/FOG POSSIBLE IN THE UPPER CT VALLEY
THROUGH EARLY THIS MORNING...OTHERWISE MAINLY VFR THROUGH THE MORNING. A
PERIOD OF MVFR/IFR IS LIKELY BY LATE AFTERNOON ACROSS W ZONES AS
BAND OF SHOWERS WITH THE COLD FRONT MOVE THROUGH...THEN SHOWERS
AND LOWER CONDITIONS SPREADING EAST ACROSS REST OF SNE 00-06Z
TONIGHT. LOW PROB OF AN ISOLD TSTM. SW WIND GUSTS TO 30 KT POSSIBLE
TODAY IN THE COASTAL PLAIN. MAINLY VFR TUESDAY.
KBOS TAF...MODERATE CONFIDENCE. A PERIOD OF MVFR CIGS/VSBYS LIKELY
THIS EVENING MAINLY AFT 22Z AS SHOWERS MOVE THROUGH...AND THERE
IS A CHANCE CIGS COULD BRIEFLY DROP TO IFR. SW WIND GUSTS TO 30 KT
POSSIBLE TODAY.
KBDL TAF...MODERATE CONFIDENCE. A PERIOD OF MVFR CIGS/VSBYS LIKELY
LATE AFTERNOON AND EARLY EVENING MAINLY AFT 20Z AS SHOWERS MOVE
THROUGH.
OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...
TUESDAY NIGHT TROUGH THURSDAY...
HIGH CONFIDENCE IN VFR CONDITIONS THROUGH THURSDAY AS HIGH PRESSURE
WILL PREVAIL. GUSTY SW WINDS MAY OCCUR ON THURSDAY REACHING 25 KTS.
FRIDAY INTO THE WEEKEND...
LOW CONFIDENCE. EXPECT MAINLY VFR HOWEVER MAY SEE SOME MVFR TO IFR
CONDITIONS DUE TO SHOWERS EVENTUALLY MOVING INTO THE REGION. VERY
UNCERTAIN ON TIMING.
&&
.MARINE...
HIGH CONFIDENCE. MODEST LOW LEVEL JET ACROSS THE REGION WILL LEAD
TO SW WIND GUSTS TO 25 KT ON THE WATERS TODAY AND HAVE SCA FOR
ENTIRE MARINE AREA. WINDS SHOULD BEGIN TO DIMINISH LATE TODAY AS
THE LLJ MOVES EAST THEN SHIFT TO W/NW LATER TONIGHT BEHIND FROPA.
THE POST FRONTAL COLD AIR ADVECTION WILL LEAD TO ANOTHER SURGE OF
NW GUSTS TO NEAR 25 KT ON TUE.
OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...
TUESDAY NIGHT...HIGH CONFIDENCE IN SCA WIND GUSTS ACROSS THE OPEN
WATERS WITHIN THE COOL ADVECTION PATTERN.
WEDNESDAY AND THURSDAY...MODERATE CONFIDENCE. WEAK RIDGE OF HIGH
PRESSURE SHOULD KEEP WINDS BELOW SCA LEVELS. HOWEVER...TROPICAL
STORM RAFAEL WHICH IS EXPECTED TO BECOME A HURRICANE WILL PASS WELL
TO THE EAST OF SOUTHERN NEW ENGLAND. THIS WILL LIKELY RESULT IN
EASTERLY SWELL AND SCA SEAS ACROSS OUR OUTER-WATERS WED INTO THU.
FRIDAY...LOW CONFIDENCE. SCA CONDITIONS MAY DEVELOP AHEAD OF AN
APPROACHING COLD FRONT BUT VERY UNCERTAIN ON THE TIMING.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR
ANZ230>234-236-251.
SMALL CRAFT ADVISORY UNTIL 2 AM EDT TUESDAY FOR ANZ235-237.
SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ250.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT TUESDAY FOR ANZ254>256.
&&
$$
SYNOPSIS...KJC/DUNTEN
NEAR TERM...KJC/DUNTEN
SHORT TERM...KJC
LONG TERM...DUNTEN
AVIATION...KJC/DUNTEN
MARINE...KJC/DUNTEN
AREA FORECAST DISCUSSION
NWS NEW YORK NY
654 AM EDT MON OCT 15 2012
.SYNOPSIS...
A COLD FRONT WILL SLOWLY APPROACH THE TRI-STATE REGION TODAY...AND
PASS TONIGHT. GUSTY WINDS WILL USHER IN A COOLER AIRMASS FOR
TUESDAY. HIGH PRESSURE WILL BUILD INTO THE REGION TUESDAY NIGHT
THROUGH THURSDAY...BEFORE MOVING EAST OF THE AREA THURSDAY NIGHT.
A STORM SYSTEM MAY IMPACT THE AREA NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A COLD FRONT IS LOCATED IN WESTERN PENNSYLVANIA THIS MORNING. THE
CWA WILL REMAIN IN THE WARM SECTOR BEFORE THE FRONT ARRIVES.
CLOUDS HAVE OVERSPREAD MUCH OF THE CWA...HOWEVER IT WILL TAKE
SLIGHTLY LONGER FOR PRECIPITATION TO MOVE IN.
H3 JET WILL SLOWLY APPROACH FROM THE W TODAY. THIS WILL AID IN
THE DEVELOPMENT OF RAIN ALONG AND AHEAD OF THE FRONT. MODELS VERY
CLOSE WITH TIMING AND PLACEMENT AND A BLEND WAS USED FOR THE FCST.
MAIN BAND OF PCPN APPEARS TO COME THRU IN THE LATE AFTN AND EVE IN
ASSOCIATION WITH THE RR QUAD OF THE JET. CAPE IS WEAK AND SKINNY.
WITH STRONG WINDS IN THE MID TO UPR LVLS...EXPECT ANY UPDRAFTS TO
BE SHEARED APART. WILL THEREFORE NOT FCST TSTMS. TEMPS TODAY CLOSE
TO THE BCMAV/LAV.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
RAIN TRAVERSES THE CWA FROM W TO E TNGT. WINDS SHIFT TO THE NW
AND THE PCPN CUTS OFF AFT FROPA. FRONT AND PCPN TIMED TO CLEAR ERN
ZONES BEFORE SUNRISE TUE. TEMPS CLOSE TO THE MET WITH WINDS
STAYING UP. MAV APPEARS TOO COLD BASED ON UPSTREAM TEMPS CURRENTLY
BEING RECORDED.
SUNNY AND BREEZY ON TUE WITH A 1015 HIGH OVER THE SERN CONUS AND A
990 LOW OVER THE MARITIMES. HIGHS BLW CLIMO BY A FEW DEGREES WITH
H85 TEMPS IN THE LOW SINGLE DIGITS C.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE BUILDS INTO THE REGION TO START THE LONG TERM PERIOD
TUESDAY NIGHT. THIS HIGH IS FORECAST TO REMAIN OVER THE REGION
THROUGH THURSDAY MORNING...PROVIDING THE LOCAL AREA WITH FAIR AND DRY
CONDITIONS. A WEAK SHORTWAVE PASSING NORTH OF THE REGION COULD
PROVIDE THE AREA WITH SOME CLOUDS WEDNESDAY...OTHERWISE WE ARE
LOOKING FOR MOSTLY CLEAR CONDITIONS.
THE HIGH WILL MOVE OFF TO THE EAST THURSDAY AFTERNOON AND
EVENING...WITH THE ARRIVAL OF THE NEXT STORM SYSTEM. WITH MODEL
DISCREPANCIES...HAVE NOT MADE ANY SIGNIFICANT CHANGES TO THE
FORECAST.
THE EC/CMC MEANS ARE FURTHER S WITH THE UPPER LOW NEAR IOWA ON
THU WHILE THE GFS MEAN IS CLOSER TO LAKE SUPERIOR. THE
DETERMINISTIC MODELS SUPPORT THE SLOWER FURTHER S SOLN AND THIS
GENERAL IDEA WAS FOLLOWED ALTHOUGH HAVE NOT TOTALLY DISREGARDED
THE FASTER GFS. LONG PERIOD OF POPS STARTING THU NIGHT AND
CONTINUING RIGHT THROUGH SUN. THIS IS MAINLY DUE TO THE TIMING
DISCREPANCIES AND SHOULD NARROW IN THE COMING DAYS. HOWEVER...DUE
TO THE SLOW NATURE OF THIS SYSTEM...A SIGNIFICANT RAINFALL IS
POSSIBLE NEXT WEEKEND.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
A COLD FRONT APPROACHES FROM THE WEST TODAY BEFORE PASSING THROUGH
LATE IN THE DAY INTO THIS EVENING.
S/SW WINDS AVERAGING MOSTLY 10-15 KT WITH GUSTS AROUND 20 KT BECOME
SLIGHTLY LIGHTER THIS AFTERNOON AND LESS GUSTY. WIND SHIFT TO NW
ARRIVES CLOSE TO MIDNIGHT.
PRIMARILY VFR. CIGS COULD POSSIBLY PREVAIL 1500-3000 FT DURING THE
TIME WHERE TEMPO GROUPS WITH SHRA ARE IN THE TAFS. AN ISOLATED
THUNDERSTORM IS ALSO POSSIBLE DURING THESE TEMPO PERIODS...BUT NOT
ENOUGH PROBABILITY AND COVERAGE TO MENTION IN THE FORECAST AT THIS
TIME. SHOWERS WILL ALSO BE POSSIBLE A COUPLE OF HOURS BEFORE THE
TIME INDICATED IN TAFS.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: OCCASIONAL GUSTS 16-20 KT POSSIBLE FROM
12Z-15Z. GUSTS MAY ALSO ONLY BE OCCASIONAL AFTER 15Z.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: OCCASIONAL GUSTS AROUND 20 KT POSSIBLE THROUGH
15Z. GUSTS MAY ALSO ONLY BE OCCASIONAL AFTER 15Z.
KLGA FCSTER COMMENTS: OCCASIONAL GUSTS AROUND 20 KT POSSIBLE FROM
12Z-15Z. GUSTS MAY ALSO ONLY BE OCCASIONAL AFTER 15Z.
KTEB FCSTER COMMENTS: OCCASIONAL GUSTS 16-20 KT POSSIBLE FROM
12Z-15Z. GUSTS MAY ALSO ONLY BE OCCASIONAL AFTER 15Z.
KHPN FCSTER COMMENTS: GUSTS MAY ONLY BE OCCASIONAL.
KISP FCSTER COMMENTS: GUSTS MAY ONLY BE OCCASIONAL AFTER 16Z.
OUTLOOK FOR 06Z TUE THROUGH FRIDAY...
.MONDAY NIGHT...VFR. OCCASIONAL NW GUSTS AROUND 20 KT.
.TUESDAY...VFR. NW GUSTS AROUND 25 KT.
.WEDNESDAY-THURSDAY...VFR.
.FRIDAY...S GUSTS 20-25 KT. CHC SHRA/CIGS BLO 3KFT IN RAIN.
&&
.MARINE...
SCA CONDITIONS WILL CONTINUE TODAY ON S WINDS. WINDS WILL DECREASE
A BIT TNGT...BUT SEAS WILL REMAIN ELEVATED ON THE OCEAN. WILL
ALLOW THE SCA TO END ON THE PROTECTED WATERS THIS EVE...AND
MAINTAIN IT ON THE OCEAN. EXTENDED THE SCA ON THE OCEAN THRU TUE
WITH INCREASING NW WINDS. CONDITIONS WILL BE CLOSE TO SCA LVLS ON
THE REMAINDER OF THE WATERS...SO AN ADVY IS POSSIBLE FOR TUE.
WINDS WILL GRADUALLY FALL BELOW SCA LEVELS TUESDAY NIGHT AND
REMAIN BELOW SCA LEVELS THROUGH AT LEAST THURSDAY WITH A WEAK
PRESSURE GRADIENT ACROSS THE AREA.
WINDS INCREASE ON FRIDAY AND SHOULD REMAIN UP THROUGH THE WEEKEND AS
A STORM SYSTEM APPROACHES AND MOVES ACROSS THE AREA WATERS. QUESTION
REMAINS ON THE EXACT TIMING OF WHEN THE SMALL CRAFT ADVISORY WINDS
IMPACT THE AREA WATERS...WHICH WILL DEPEND ON HOW THE STORM SYSTEM
EVOLVES COMING OUT OF THE MID-SECTION OF THE COUNTRY.
SEAS ON THE OCEAN WATERS ARE A DIFFERENT STORY. INCREASING SWELLS
FROM RAFAEL COULD KEEP SEAS ABOVE 5 FT THROUGH THE FORECAST PERIOD.
FOR THE LATEST ON RAFAEL...PLEASE REFER TO PRODUCTS ISSUED BY THE
NATIONAL HURRICANE CENTER.
&&
.HYDROLOGY...
3/4 OF AN INCH OR LESS OF RAIN IS EXPECTED THRU TNGT. FLOODING IS
NOT EXPECTED. DRY WEATHER TUE THRU AT LEAST THU.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ330-
335-338-340-345.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...BC/JMC
NEAR TERM...JMC
SHORT TERM...JMC
LONG TERM...BC
AVIATION...JC
MARINE...BC/JMC
HYDROLOGY...JMC
AREA FORECAST DISCUSSION
NWS NEW YORK NY
430 AM EDT MON OCT 15 2012
.SYNOPSIS...
A COLD FRONT WILL SLOWLY APPROACH THE TRI-STATE REGION TODAY...AND
PASS TONIGHT. GUSTY WINDS WILL USHER IN A COOLER AIRMASS FOR
TUESDAY. HIGH PRESSURE WILL BUILD INTO THE REGION TUESDAY NIGHT
THROUGH THURSDAY...BEFORE MOVING EAST OF THE AREA THURSDAY NIGHT.
A STORM SYSTEM MAY IMPACT THE AREA NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 10 AM THIS MORNING/...
THE COLD FRONT WAS APPROACHING THE OH/PA BORDER AT 3AM. CWA WILL
REMAIN IN THE WARM SECTOR BEFORE THE FRONT ARRIVES. TEMPS MILD THIS
MRNG AND WITH CLOUDS OVERSPREADING WRN ZONES...TEMPS THERE WILL
REMAIN STEADY OR RISE BEFORE SUNRISE. SIMILAR TEMP SCENARIO ALONG
THE COASTS WITH THE WIND COMING IN OFF THE WATER. PCPN WILL STAY W
OF THE CWA CLOSER TO THE UPR FORCING THRU THE MRNG HRS.
&&
.SHORT TERM /10 AM THIS MORNING THROUGH 6 PM TUESDAY/...
H3 JET WILL SLOWLY APPROACH FROM THE W TODAY. THIS WILL AID IN THE
DEVELOPMENT OF RAIN ALONG AND AHEAD OF THE FRONT. MODELS VERY
CLOSE WITH TIMING AND PLACEMENT AND A BLEND WAS USED FOR THE FCST.
MAIN BAND OF PCPN APPEARS TO COME THRU IN THE LATE AFTN AND EVE IN
ASSOCIATION WITH THE RR QUAD OF THE JET. CAPE IS WEAK AND SKINNY.
WITH STRONG WINDS IN THE MID TO UPR LVLS...EXPECT ANY UPDRAFTS TO
BE SHEARED APART. WILL THEREFORE NOT FCST TSTMS. TEMPS TODAY CLOSE
TO THE BCMAV.
RAIN TRAVERSES THE CWA FROM W TO E TNGT. WINDS SHIFT TO THE NW AND
THE PCPN CUTS OFF AFT FROPA. FRONT AND PCPN TIMED TO CLEAR ERN
ZONES BEFORE SUNRISE TUE. TEMPS CLOSE TO THE MET WITH WINDS
STAYING UP. MAV APPEARS TOO COLD BASED ON UPSTREAM TEMPS CURRENTLY
BEING RECORDED.
SUNNY AND BREEZY ON TUE WITH A 1015 HIGH OVER THE SERN CONUS AND A
990 LOW OVER THE MARITIMES. HIGHS BLW CLIMO BY A FEW DEGREES WITH
H85 TEMPS IN THE LOW SINGLE DIGITS C.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE BUILDS INTO THE REGION TO START THE LONG TERM PERIOD
TUESDAY NIGHT. THIS HIGH IS FORECAST TO REMAIN OVER THE REGION
THROUGH THURSDAY MORNING...PROVIDING THE LOCAL AREA WITH FAIR AND DRY
CONDITIONS. A WEAK SHORTWAVE PASSING NORTH OF THE REGION COULD
PROVIDE THE AREA WITH SOME CLOUDS WEDNESDAY...OTHERWISE WE ARE
LOOKING FOR MOSTLY CLEAR CONDITIONS.
THE HIGH WILL MOVE OFF TO THE EAST THURSDAY AFTERNOON AND
EVENING...WITH THE ARRIVAL OF THE NEXT STORM SYSTEM. WITH MODEL
DISCREPANCIES...HAVE NOT MADE ANY SIGNIFICANT CHANGES TO THE
FORECAST.
THE EC/CMC MEANS ARE FURTHER S WITH THE UPPER LOW NEAR IOWA ON
THU WHILE THE GFS MEAN IS CLOSER TO LAKE SUPERIOR. THE
DETERMINISTIC MODELS SUPPORT THE SLOWER FURTHER S SOLN AND THIS
GENERAL IDEA WAS FOLLOWED ALTHOUGH HAVE NOT TOTALLY DISREGARDED
THE FASTER GFS. LONG PERIOD OF POPS STARTING THU NIGHT AND
CONTINUING RIGHT THROUGH SUN. THIS IS MAINLY DUE TO THE TIMING
DISCREPANCIES AND SHOULD NARROW IN THE COMING DAYS. HOWEVER...DUE
TO THE SLOW NATURE OF THIS SYSTEM...A SIGNIFICANT RAINFALL IS
POSSIBLE NEXT WEEKEND.
TEMPS START OFF SLIGHTLY BELOW NORMAL ON TUE...GRADUALLY WARMING
TO A FEW DEGREES ABOVE NORMAL BY THU.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
A COLD FRONT APPROACHES FROM THE WEST TODAY BEFORE PASSING THROUGH
LATE IN THE DAY INTO THIS EVENING.
S/SW WINDS AVERAGING MOSTLY 10-15 KT WITH GUSTS AROUND 20 KT BECOME
SLIGHTLY LIGHTER THIS AFTERNOON AND LESS GUSTY. WIND SHIFT TO NW
ARRIVES CLOSE TO MIDNIGHT.
PRIMARILY VFR. CIGS COULD POSSIBLY PREVAIL 1500-3000 FT DURING THE
TIME WHERE TEMPO GROUPS WITH SHRA ARE IN THE TAFS. AN ISOLATED
THUNDERSTORM IS ALSO POSSIBLE DURING THESE TEMPO PERIODS...BUT NOT
ENOUGH PROBABILITY AND COVERAGE TO MENTION IN THE FORECAST AT THIS
TIME. SHOWERS WILL ALSO BE POSSIBLE A COUPLE OF HOURS BEFORE THE
TIME INDICATED IN TAFS.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: OCCASIONAL GUSTS 16-20 KT POSSIBLE FROM
12Z-15Z. GUSTS MAY ALSO ONLY BE OCCASIONAL AFTER 15Z.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: OCCASIONAL GUSTS AROUND 20 KT POSSIBLE THROUGH
15Z. GUSTS MAY ALSO ONLY BE OCCASIONAL AFTER 15Z.
KLGA FCSTER COMMENTS: OCCASIONAL GUSTS AROUND 20 KT POSSIBLE FROM
12Z-15Z. GUSTS MAY ALSO ONLY BE OCCASIONAL AFTER 15Z.
KTEB FCSTER COMMENTS: OCCASIONAL GUSTS 16-20 KT POSSIBLE FROM
12Z-15Z. GUSTS MAY ALSO ONLY BE OCCASIONAL AFTER 15Z.
KHPN FCSTER COMMENTS: GUSTS MAY ONLY BE OCCASIONAL.
KISP FCSTER COMMENTS: GUSTS MAY ONLY BE OCCASIONAL AFTER 16Z.
OUTLOOK FOR 06Z TUE THROUGH FRIDAY...
.MONDAY NIGHT...VFR. OCCASIONAL NW GUSTS AROUND 20 KT.
.TUESDAY...VFR. NW GUSTS AROUND 25 KT.
.WEDNESDAY-THURSDAY...VFR.
.FRIDAY...S GUSTS 20-25 KT. CHC SHRA/CIGS BLO 3KFT IN RAIN.
&&
.MARINE...
SCA CONDITIONS WILL CONTINUE TODAY ON S WINDS. WINDS WILL DECREASE
A BIT TNGT...BUT SEAS WILL REMAIN ELEVATED ON THE OCEAN. WILL
ALLOW THE SCA TO END ON THE PROTECTED WATERS THIS EVE...AND
MAINTAIN IT ON THE OCEAN. EXTENDED THE SCA ON THE OCEAN THRU TUE
WITH INCREASING NW WINDS. CONDITIONS WILL BE CLOSE TO SCA LVLS ON
THE REMAINDER OF THE WATERS...SO AN ADVY IS POSSIBLE FOR TUE.
WINDS WILL GRADUALLY FALL BELOW SCA LEVELS TUESDAY NIGHT AND
REMAIN BELOW SCA LEVELS THROUGH AT LEAST THURSDAY WITH A WEAK
PRESSURE GRADIENT ACROSS THE AREA.
WINDS INCREASE ON FRIDAY AND SHOULD REMAIN UP THROUGH THE WEEKEND AS
A STORM SYSTEM APPROACHES AND MOVES ACROSS THE AREA WATERS. QUESTION
REMAINS ON THE EXACT TIMING OF WHEN THE SMALL CRAFT ADVISORY WINDS
IMPACT THE AREA WATERS...WHICH WILL DEPEND ON HOW THE STORM SYSTEM
EVOLVES COMING OUT OF THE MID-SECTION OF THE COUNTRY.
SEAS ON THE OCEAN WATERS ARE A DIFFERENT STORY. INCREASING SWELLS
FROM RAFAEL COULD KEEP SEAS ABOVE 5 FT THROUGH THE FORECAST PERIOD.
FOR THE LATEST ON RAFAEL...PLEASE REFER TO PRODUCTS ISSUED BY THE
NATIONAL HURRICANE CENTER.
&&
.HYDROLOGY...
3/4 OF AN INCH OR LESS OF RAIN IS EXPECTED THRU TNGT. FLOODING IS
NOT EXPECTED. DRY WEATHER TUE THRU AT LEAST THU.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ330-
335-338-340-345.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...BC/JMC
NEAR TERM...JMC
SHORT TERM...JMC
LONG TERM...BC
AVIATION...JC
MARINE...BC/JMC
HYDROLOGY...JMC
AREA FORECAST DISCUSSION
NWS NEW YORK NY
322 AM EDT MON OCT 15 2012
.SYNOPSIS...
A COLD FRONT WILL SLOWLY APPROACH THE TRI-STATE REGION TODAY...AND
PASS TONIGHT. GUSTY WINDS WILL USHER IN A COOLER AIRMASS FOR
TUESDAY. HIGH PRESSURE WILL BUILD INTO THE REGION TUESDAY NIGHT
THROUGH THURSDAY...BEFORE MOVING EAST OF THE AREA THURSDAY NIGHT.
A STORM SYSTEM MAY IMPACT THE AREA NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 10 AM THIS MORNING/...
THE COLD FRONT WAS APPROACHING THE OH/PA BORDER AT 3AM. CWA WILL
REMAIN IN THE WARM SECTOR BEFORE THE FRONT ARRIVES. TEMPS MILD THIS
MRNG AND WITH CLOUDS OVERSPREADING WRN ZONES...TEMPS THERE WILL
REMAIN STEADY OR RISE BEFORE SUNRISE. SIMILAR TEMP SCENARIO ALONG
THE COASTS WITH THE WIND COMING IN OFF THE WATER. PCPN WILL STAY W
OF THE CWA CLOSER TO THE UPR FORCING THRU THE MRNG HRS.
&&
.SHORT TERM /10 AM THIS MORNING THROUGH 6 PM TUESDAY/...
H3 JET WILL SLOWLY APPROACH FROM THE W TODAY. THIS WILL AID IN THE
DEVELOPMENT OF RAIN ALONG AND AHEAD OF THE FRONT. MODELS VERY
CLOSE WITH TIMING AND PLACEMENT AND A BLEND WAS USED FOR THE FCST.
MAIN BAND OF PCPN APPEARS TO COME THRU IN THE LATE AFTN AND EVE IN
ASSOCIATION WITH THE RR QUAD OF THE JET. CAPE IS WEAK AND SKINNY.
WITH STRONG WINDS IN THE MID TO UPR LVLS...EXPECT ANY UPDRAFTS TO
BE SHEARED APART. WILL THEREFORE NOT FCST TSTMS. TEMPS TODAY CLOSE
TO THE BCMAV.
RAIN TRAVERSES THE CWA FROM W TO E TNGT. WINDS SHIFT TO THE NW AND
THE PCPN CUTS OFF AFT FROPA. FRONT AND PCPN TIMED TO CLEAR ERN
ZONES BEFORE SUNRISE TUE. TEMPS CLOSE TO THE MET WITH WINDS
STAYING UP. MAV APPEARS TOO COLD BASED ON UPSTREAM TEMPS CURRENTLY
BEING RECORDED.
SUNNY AND BREEZY ON TUE WITH A 1015 HIGH OVER THE SERN CONUS AND A
990 LOW OVER THE MARITIMES. HIGHS BLW CLIMO BY A FEW DEGREES WITH
H85 TEMPS IN THE LOW SINGLE DIGITS C.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE BUILDS INTO THE REGION TO START THE LONG TERM PERIOD
TUESDAY NIGHT. THIS HIGH IS FORECAST TO REMAIN OVER THE REGION
THROUGH THURSDAY MORNING...PROVIDING THE LOCAL AREA WITH FAIR AND DRY
CONDITIONS. A WEAK SHORTWAVE PASSING NORTH OF THE REGION COULD
PROVIDE THE AREA WITH SOME CLOUDS WEDNESDAY...OTHERWISE WE ARE
LOOKING FOR MOSTLY CLEAR CONDITIONS.
THE HIGH WILL MOVE OFF TO THE EAST THURSDAY AFTERNOON AND
EVENING...WITH THE ARRIVAL OF THE NEXT STORM SYSTEM. WITH MODEL
DISCREPANCIES...HAVE NOT MADE ANY SIGNIFICANT CHANGES TO THE
FORECAST.
THE EC/CMC MEANS ARE FURTHER S WITH THE UPPER LOW NEAR IOWA ON
THU WHILE THE GFS MEAN IS CLOSER TO LAKE SUPERIOR. THE
DETERMINISTIC MODELS SUPPORT THE SLOWER FURTHER S SOLN AND THIS
GENERAL IDEA WAS FOLLOWED ALTHOUGH HAVE NOT TOTALLY DISREGARDED
THE FASTER GFS. LONG PERIOD OF POPS STARTING THU NIGHT AND
CONTINUING RIGHT THROUGH SUN. THIS IS MAINLY DUE TO THE TIMING
DISCREPANCIES AND SHOULD NARROW IN THE COMING DAYS. HOWEVER...DUE
TO THE SLOW NATURE OF THIS SYSTEM...A SIGNIFICANT RAINFALL IS
POSSIBLE NEXT WEEKEND.
TEMPS START OFF SLIGHTLY BELOW NORMAL ON TUE...GRADUALLY WARMING
TO A FEW DEGREES ABOVE NORMAL BY THU.
&&
.AVIATION /07Z MONDAY THROUGH FRIDAY/...
A COLD FRONT APPROACHES FROM THE WEST TODAY BEFORE PASSING THROUGH
LATE IN THE DAY INTO THIS EVENING.
S/SW WINDS AVERAGING MOSTLY 10-15 KTS BECOME SLIGHTLY LIGHTER THIS
AFTERNOON AND LESS GUSTY. WIND SHIFT TO NW ARRIVES CLOSE TO
MIDNIGHT.
PRIMARILY VFR. CIGS COULD POSSIBLY PREVAIL 1500-3000 FT DURING THE
TIME WHERE TEMPO GROUPS WITH SHRA ARE IN THE TAFS. AN ISOLATED
THUNDERSTORM IS ALSO POSSIBLE DURING THESE TEMPO PERIODS...BUT NOT
ENOUGH PROBABILITY AND COVERAGE TO MENTION IN THE FORECAST AT THIS
TIME.
OUTLOOK FOR 06Z TUE THROUGH FRIDAY...
.MONDAY NIGHT...VFR. OCCASIONAL NW GUSTS AROUND 20 KT.
.TUESDAY...VFR. NW GUSTS AROUND 25 KT.
.WEDNESDAY-THURSDAY...VFR.
.FRIDAY...S GUSTS 20-25 KT. CHC SHRA/CIGS BLO 3KFT IN RAIN.
&&
.MARINE...
SCA CONDITIONS WILL CONTINUE TODAY ON S WINDS. WINDS WILL DECREASE
A BIT TNGT...BUT SEAS WILL REMAIN ELEVATED ON THE OCEAN. WILL
ALLOW THE SCA TO END ON THE PROTECTED WATERS THIS EVE...AND
MAINTAIN IT ON THE OCEAN. EXTENDED THE SCA ON THE OCEAN THRU TUE
WITH INCREASING NW WINDS. CONDITIONS WILL BE CLOSE TO SCA LVLS ON
THE REMAINDER OF THE WATERS...SO AN ADVY IS POSSIBLE FOR TUE.
WINDS WILL GRADUALLY FALL BELOW SCA LEVELS TUESDAY NIGHT AND
REMAIN BELOW SCA LEVELS THROUGH AT LEAST THURSDAY WITH A WEAK
PRESSURE GRADIENT ACROSS THE AREA.
WINDS INCREASE ON FRIDAY AND SHOULD REMAIN UP THROUGH THE WEEKEND AS
A STORM SYSTEM APPROACHES AND MOVES ACROSS THE AREA WATERS. QUESTION
REMAINS ON THE EXACT TIMING OF WHEN THE SMALL CRAFT ADVISORY WINDS
IMPACT THE AREA WATERS...WHICH WILL DEPEND ON HOW THE STORM SYSTEM
EVOLVES COMING OUT OF THE MID-SECTION OF THE COUNTRY.
SEAS ON THE OCEAN WATERS ARE A DIFFERENT STORY. INCREASING SWELLS
FROM RAFAEL COULD KEEP SEAS ABOVE 5 FT THROUGH THE FORECAST PERIOD.
FOR THE LATEST ON RAFAEL...PLEASE REFER TO PRODUCTS ISSUED BY THE
NATIONAL HURRICANE CENTER.
&&
.HYDROLOGY...
3/4 OF AN INCH OR LESS OF RAIN IS EXPECTED THRU TNGT. FLOODING IS
NOT EXPECTED. DRY WEATHER TUE THRU AT LEAST THU.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ330-
335-338-340-345.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT TUESDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...BC/JMC
NEAR TERM...JMC
SHORT TERM...JMC
LONG TERM...BC
AVIATION...JC
MARINE...BC/JMC
HYDROLOGY...JMC
AREA FORECAST DISCUSSION
NWS MIAMI FL
332 PM EDT MON OCT 15 2012
.SHORT TERM (TONIGHT-WEDNESDAY NIGHT)...
THE LATEST SURFACE ANALYSIS SHOWED A COLD FRONT EXTENDING
SOUTHWEST FROM THE CAROLINAS TO THE NORTHERN GULF OF MEXICO WITH
PLENTY OF DRY AIR OVERSPREADING THE REGION IN ITS WAKE. OUT AHEAD OF
THIS BOUNDARY OVER OUR AREA...MOISTURE AND DEWPOINTS HAVE INCREASED
OVER THE PAST DAY. THIS INCREASE IN MOISTURE (MOSTLY LOW LEVEL)
COMBINED WITH DIURNAL HEATING AND LOCAL SEA BREEZES HAVE ALREADY
BEEN ENOUGH TO TRIGGER SCATTERED SHOWERS EARLIER THIS AFTERNOON
ACROSS THE WESTERN HALF OF THE SRN FL PENINSULA. THE LATEST HRRR AND
WRF MODEL REFLECTIVITIES SHOW SIMILAR RESULTS AND INDICATE MAINLY
ISOLATED TO SCATTERED AFTERNOON COVERAGE FAVORING THE INLAND AND
WEST GULF COAST CONTINUING THROUGH THE EVENING HOURS WITH MAINLY
ISOLATED THUNDERSTORMS.
TUESDAY THROUGH THE MID WEEK...A FAIRLY PROGRESSIVE UPPER PATTERN IS
EXPECTED ACROSS THE REGION CHARACTERIZED BY A SERIES OF SHORTWAVE
TROUGHS TRANSLATING EWD. THE FIRST OF WHICH IS FORECAST TO PASS OVER
THE STATE EARLY TUESDAY MORNING USHERING IN ANOTHER SURGE OF DRIER
AIR THAT WILL SPREAD INTO THE LOCAL AREA FROM NORTH TO SOUTH THROUGH
THE COURSE OF THE DAY TUESDAY ALONG WITH THE PREVIOUSLY MENTIONED
COLD FRONT AS IT CONTINUES SOUTH INTO THE AREA AND BEGINS TO
DIMINISH. DEWPOINTS ARE FORECAST TO BRIEFLY DIP BACK INTO THE MID TO
UPPER 60S THROUGH THIS TIME...MAINLY INLAND. THEREFORE...MAINLY
ISOLATED SHOWERS WILL BE POSSIBLE WITHIN THE NORTHEAST FLOW OFF THE
ATL WATERS ACROSS THE EAST AND SRN AREAS TOMORROW AFTN/EVENING. ON
WEDNESDAY...MODELS INDICATE ANOTHER SHORTWAVE TROUGH TRANSLATING EWD
ACROSS THE REGION WITH INCREASING DEEP LAYER MOISTURE. WESTERLY FLOW
THAT IS FORECAST...SHOULD RESULT IN THE BULK OF THE ACTIVITY AND
COVERAGE TO SETUP OVER THE INTERIOR AND EAST COAST SECTIONS OF THE
LOCAL AREA THROUGH THIS TIME. THEREFORE...WILL BRING BACK THE CHANCE
FOR SHOWER/TSTMS LATER WEDNESDAY INTO WEDNESDAY NIGHT AHEAD OF THIS
UPPER FEATURE.
MIAMI BEACH COASTAL FLOODING CONCERNS....EARLIER THIS
MORNING...THERE WERE REPORTS OF SOME MINOR STREET FLOODING IN THE
SOUTH BEACH AREA ALONG PURDY AVE/20TH STREET DURING THE HIGH TIDE
CYCLE (AS WELL AS A FEW OTHER STREETS IN THE SAME GENERAL AREA).
THIS WAS MOSTLY CONTRIBUTED TO THE WATER LEVELS RUNNING SLIGHTLY
ABOVE NORMAL DUE TO THE COMBINATION OF SPRING TIDES AND THE
INFLUENCE OF THE STRONG ONSHORE WINDS AND ELEVATED SEAS OBSERVED
OVER THE WEEKEND. EXPECT THIS POTENTIAL TO CONTINUE AT EACH HIGH
TIDE CYCLE THIS EVENING AND AGAIN TUESDAY MORNING JUST AFTER
DAYBREAK BEFORE DECREASING THROUGH THE MID-WEEK PERIOD. ALTHOUGH THE
THREAT IS LOW...ANY ADDITIONAL RAINFALL THAT BECOMES CONCENTRATED
OVER THESE AREAS COULD RESULT IN ADDITIONAL FLOODING OR STANDING
WATER CONCERNS THROUGH THIS TIME. THE NEXT HIGH TIDE CYCLE WILL COME
LATER THIS EVENING BETWEEN 8 AND 9 PM AND AGAIN TOMORROW MORNING
AROUND THE MID-MORNING TIME FRAME.
.LONG TERM (THURSDAY-WEEKEND)...
FOR LATE WEEK INTO NEXT WEEKEND, BOTH GFS/ECMWF SHOW A STRONG CLOSED
MID/UPPER LOW DIVING ACROSS THE GREAT LAKES STATES WITH A TROUGH
EXTENDING SOUTH INTO THE GULF OF MEXICO. BOTH MODELS SHOW WARM,
HUMID CONDITIONS LATE WEEK AHEAD OF THIS SYSTEM AND JUST CANNOT
SHUT MENTION OF SHOWERS/TSTORMS OFF ANY DAY DUE TO SUFFICIENT
MOISTURE/INSTABILITY CONTINUING...ESPECIALLY OVER THE WEEKEND.
BOTH MODELS HAVE BEEN GRADUALLY BACKING OFF ON THE THRUST OF THIS
COLD FRONT FOR SOUTH FLORIDA...ESPECIALLY NOW THE GFS WHICH KEEPS
DEWPOINTS IN THE LOWER 70S ALL THE WAY THROUGH NEXT WEEKEND AND
INTO NEXT WEEK. THE ECMWF SHOWS SLIGHTLY DRIER AIR BEHIND THE
BOUNDARY BY MONDAY...BUT EVEN IT SHOWS WINDS QUICKLY TO THE EAST
BEHIND IT. SO THE BOTTOM LINE IS WARM, HUMID CONDITIONS LOOK TO
PREVAIL THROUGH THE FORECAST PERIOD ALONG WITH DAILY CHANCES OF
SHOWERS/TSTORMS.
&&
.MARINE...
WINDS AND SEAS WILL CONTINUE TO SUBSIDE OVER THE MARINE AREA THROUGH
THE MID WEEK AS A WEAKENING COLD FRONT APPROACHES AND MOVES INTO THE
AREA FROM THE NORTH. AN EASTERLY SWELL WILL BEGIN TO OVERSPREAD THE
ATLANTIC WATERS THROUGH THE DAY TUESDAY AND CONTINUE THROUGH THE MID
WEEK PERIOD BEFORE SUBSIDING. OUTSIDE OF THE SWELL ENERGY THAT
PROGRESSES THROUGH THE PROVIDENCE CHANNEL AND SPREADS OVER THE
MARINE AREAS...MOST OF THIS ACTIVITY WILL IMPACT THE FLORIDA EAST
COAST NORTH OF JUPITER INLET THROUGH THIS TIME. ISOLATED TO
SCATTERED SHOWERS WILL REMAIN POSSIBLE EACH DAY THROUGH THE PERIOD.
&&
.FIRE WEATHER...
RELATIVE HUMIDITIES ARE FORECAST TO REMAIN WELL ABOVE CRITICAL
LEVELS WITH NO RED FLAG CONCERNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 75 88 72 86 / 10 20 20 40
FORT LAUDERDALE 74 87 74 85 / 10 20 20 40
MIAMI 75 87 73 87 / 10 20 20 40
NAPLES 73 87 71 84 / 20 10 10 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...55/CWC
LONG TERM...DG
AREA FORECAST DISCUSSION
NWS MIAMI FL
132 PM EDT MON OCT 15 2012
.AVIATION...
VFR CONDITIONS WILL PREVAIL THROUGHOUT THE FORECAST PERIOD.
SLIGHTLY DRIER AIR WILL MOVE INTO THE REGION THIS AFTERNOON,
HOWEVER WE WILL KEEP THE VCSH IN ACROSS ALL TERMINALS. THERE COULD
BE A FEW THUNDERSTORMS ACROSS INTERIOR SECTIONS, HOWEVER THEY
SHOULD BE FAR ENOUGH AWAY FROM THE TERMINALS. WINDS WILL REMAIN
OUT OF THE NORTHEAST THIS AFTERNOON ACROSS THE EAST COAST
TERMINALS. AT KAPF A GULF SEA BREEZE WILL DEVELOP THIS AFTERNOON
ALLOWING THE WINDS TO SHIFT TO THE WEST NORTHWEST. THESE WINDS
WILL SHIFT BACK TO THE NORTHEAST THIS EVENING.
&&
.PREV DISCUSSION... /ISSUED 1135 AM EDT MON OCT 15 2012/
UPDATE...
OUTSIDE OF A FEW MINOR UPDATES WITHIN THE GRIDDED FORECAST
DATABASE BASED ON THE LATEST OBSERVATIONS AND RADAR TRENDS...THE
PREVIOUS FORECAST REMAINS ON TRACK. THE FOG THAT OCCURRED THIS
MORNING ACROSS WESTERN COLLIER COUNTY HAS LIFTED OR BURNED OFF.
THE LATEST SURFACE ANALYSIS SHOWED A COLD FRONT EXTENDING
SOUTHWEST FROM GEORGIA TO LOUISIANA WITH PLENTY OF DRY AIR
OVERSPREADING THE REGION IN ITS WAKE. OUT AHEAD OF THIS BOUNDARY
OVER OUR AREA...MOISTURE AND DEWPOINTS HAVE INCREASED OVER THE
PAST DAY. THE MORNING UPPER SOUNDING IN MIAMI SHOWED A
PRECIPITABLE WATER VALUE OF 1.51 INCHES...WHICH IS FORECAST TO
CONTINUE TO INCREASE SLIGHTLY THROUGH TONIGHT ACROSS THE AREA.
THIS INCREASE IN MOISTURE COMBINED WITH DIURNAL HEATING AND LOCAL
SEA BREEZES WILL BE ENOUGH TO TRIGGER SCATTERED SHOWERS THIS
AFTERNOON AND ISOLATED TSTMS. THE LATEST HRRR AND WRF MODEL
REFLECTIVITIES SHOW SIMILAR RESULTS AND INDICATE MAINLY ISOLATED
TO SCATTERED AFTERNOON COVERAGE FAVORING THE INLAND AND WEST GULF
COAST AREAS TODAY.
THERE WAS A REPORT OF SOME MINOR STREET FLOODING IN THE SOUTH
BEACH AREA ALONG PURDY AVE/20TH STREET DURING THE HIGH TIDE CYCLE
THIS MORNING. THIS IS MOSTLY CONTRIBUTED TO THE PERIGEAN SPRING
TIDE AND WATER LEVELS RUNNING SLIGHT ABOVE NORMAL. EXPECT THIS
POTENTIAL TO CONTINUE AT EACH HIGH TIDE CYCLE THROUGH TUESDAY OR
WEDNESDAY BEFORE SUBSIDING. ALTHOUGH THE THREAT IS LOW...ANY
ADDITIONAL RAINFALL THAT BECOMES CONCENTRATED OVER THESE AREAS MAY
LEAD TO ADDITIONAL FLOODING OR STANDING WATER CONCERNS THROUGH
THIS TIME. THE NEXT HIGH TIDE CYCLE WILL COME LATER THIS EVENING
BETWEEN 8 AND 9 PM. 85/AG
PREV DISCUSSION... /ISSUED 721 AM EDT MON OCT 15 2012/
AVIATION...
SCATTERED SHOWERS OVER THE ATLANTIC IN MOIST E-NE LOW LEVEL WIND
FLOW WILL AFFECT PORTIONS OF E COAST THROUGH 16Z. THIS WILL KEEP
SHOWERS IN THE VICINITY OF MOST EAST COAST TERMINALS WITH BRIEF MVFR
CONDITIONS POSSIBLE BUT NOT ENOUGH TO PUT IN TAFS. ALONG WEST COAST
AT KAPF, PATCH OF BKN/OVC STRATUS BELOW 1000 FT FORECAST SLOWLY BURN
OFF BY AROUND 13Z, ALTHOUGH WOULDN`T BE SURPRISED IF LOW CEILINGS
LINGER UNTIL PERHAPS 14Z DUE TO LIGHT WINDS AND PERSISTENT NATURE OF
THE CLOUD DECK. SLIGHTLY DRIER AIR WILL TRY TO MOVE INTO SOUTH
FLORIDA AFTER 18Z, BUT WILL KEEP VCSH ALL SITES IN LIGHT NE FLOW.
EXPECT A FEW TSTMS OVER THE INTERIOR OF THE PENINSULA 17Z-00Z BUT THESE
WILL BE ISOLATED ENOUGH TO NOT MENTION AT TAF SITES. GULF SEA BREEZE
FORECAST TO AFFECT KAPF BY 18Z WITH NW WINDS. DRIER N-NE WIND FLOW
00Z-12Z TUESDAY.
PREV DISCUSSION... /ISSUED 345 AM EDT MON OCT 15 2012/
DISCUSSION...
SOME DRIER AIR HAS ALREADY BEGUN TO MOVE INTO THE AREA FROM THE EAST
WITH GPS MET DATA SHOWING THE PWAT DOWN TO 1.5-1.6 INCHES ALONG THE
ATLANTIC COAST BUT STILL 1.8-2.0 INCHES FROM THE LAKE TO NAPLES.
EVEN WITH SOME DRYING FROM THE EAST TODAY, MOISTURE WILL BE
SUFFICIENT, ALONG WITH DEVELOPING SEA BREEZES DUE TO A LIGHTER
SYNOPTIC SCALE WIND FLOW, TO ALLOW FOR SCATTERED SHOWERS TO DEVELOP
ACROSS THE AREA. THE FOCUS IS EXPECTED TO BE ACROSS THE EAST COAST
THROUGH EARLY AFTERNOON, BEFORE SHIFTING TO THE INTERIOR/GULF COAST
LATER IN THE DAY. HAVE GONE WITH THE HIGHEST POPS OVER THE INTERIOR
WHERE THE BEST CONVERGENCE IS EXPECTED. THERE COULD BE A FEW
THUNDERSTORMS AS WELL TODAY, ESPECIALLY OVER THE INTERIOR LATE THIS
AFTERNOON. GFS/ECMWF/SREF ARE IN GENERAL AGREEMENT ON THIS
SCENARIO...AND ACTUALLY OVER THE NEXT FEW DAYS.
ONSHORE WINDS ALONG THE ATLANTIC COAST WILL CONTINUE TO RELAX, BUT
THERE IS STILL A MODERATE RISK OF RIP CURRENTS. THE WEAKER ONSHORE
WINDS MAY PRECLUDE ANY COASTAL FLOODING DESPITE HIGH TIDAL LEVELS.
THIS WILL BE MONITORED OVER THE NEXT COUPLE OF DAYS AS WE ARE IN THE
SPRING TIDE WHICH RESULTS IN HIGHER THAN NORMAL WATER LEVELS.
THIS EVENING AND THROUGH TUESDAY, FURTHER DRYING IS EXPECTED TO
ENTER INTO SOUTH FL FROM THE NORTH. A SHORTWAVE WILL BE PASSING BY
TO THE NORTH TODAY FOLLOWED BY A WEAKENING FRONTAL BOUNDARY MOVING
INTO THE AREA TONIGHT AND BECOMING DIFFUSE OVER OR JUST SOUTH OF THE
AREA ON TUESDAY WHILE WASHING OUT. PWATS ARE FORECAST TO FALL INTO
THE 1.2-1.5 INCH RANGE ON TUESDAY. HOWEVER, LINGERING LOW LEVEL
MOISTURE COULD STILL ALLOW FOR ISOLATED SHOWERS ACROSS THE EAST
COAST, SO KEPT SLIGHT CHANCE POPS EAST HALF FOR TUESDAY.
THE RIP CURRENT RISK ALONG THE ATLANTIC COAST WILL CONTINUE TO
SUBSIDE OVER THE NEXT FEW DAYS. HOWEVER, ONE CAVEAT IS THAT THE
SWAN MODEL IS SHOWING A 15 SECOND EASTERLY SWELL MOVING THROUGH
THE PROVIDENCE CHANNEL OF THE BAHAMAS AND REACHING THE SOUTHERN
PALM BEACH COAST TUE AFTERNOON. GRANTED, RIGHT NOW THE MODEL ONLY
SHOWS A SWELL HEIGHT OF 2 FT, BUT THIS COULD END UP SLIGHTLY
HIGHER. EVEN SO, GIVEN THE LONG PERIOD OF THE SWELL (15 SEC),
ROUGH SURF/DANGEROUS RIP CURRENTS COULD BRIEFLY OCCUR ACROSS SE
PALM BEACH COUNTY ON TUESDAY AFTERNOON/EVENING.
ANOTHER SHORTWAVE DIGS INTO THE GULF AND APPROACHES SOUTH FL ON WED,
WITH MOISTURE INCREASING IN ADVANCE OF THIS TROUGH. SEA BREEZE
CONVERGENCE IS EXPECTED WED, AND WITH THE HIGHER MOISTURE, THERE`S A
BETTER CHANCE OF SHOWERS AND A FEW THUNDERSTORMS ESPECIALLY
INTERIOR-EAST ON WED...DUE TO A MEAN WESTERLY STORM STEERING FLOW.
FOR LATE WEEK INTO NEXT WEEKEND, BOTH GFS/ECMWF SHOW A STRONG CLOSED
MID/UPPER LOW DIVING ACROSS THE GREAT LAKES STATES WITH A TROUGH
EXTENDING SOUTH INTO THE GULF OF MEXICO. BOTH MODELS SHOW WARM,
HUMID CONDITIONS LATE WEEK AHEAD OF THIS SYSTEM AND JUST CANNOT
SHUT MENTION OF SHOWERS/TSTORMS OFF ANY DAY DUE TO SUFFICIENT
MOISTURE/INSTABILITY CONTINUING...ESPECIALLY OVER THE WEEKEND.
BOTH MODELS HAVE BEEN GRADUALLY BACKING OFF ON THE THRUST OF THIS
COLD FRONT FOR SOUTH FLORIDA...ESPECIALLY NOW THE GFS WHICH KEEPS
DEWPOINTS IN THE LOWER 70S ALL THE WAY THROUGH NEXT WEEKEND AND
INTO NEXT WEEK. THE ECMWF SHOWS SLIGHTLY DRIER AIR BEHIND THE
BOUNDARY BY MONDAY...BUT EVEN IT SHOWS WINDS QUICKLY TO THE EAST
BEHIND IT. SO THE BOTTOM LINE IS WARM, HUMID CONDITIONS LOOK TO
PREVAIL THROUGH THE FORECAST PERIOD ALONG WITH DAILY CHANCES OF
SHOWERS/TSTORMS.
MARINE...WINDS ARE CONTINUING TO DECREASE ACROSS THE LOCAL
WATERS. SWAN OUTPUT SHOWS SIG WAVEHEIGHT OF 7 FT EARLY THIS
MORNING OVER THE PALM BEACH WATERS BEFORE DECREASING THROUGHOUT
THE DAY. SO WILL CONTINUE THE SMALL CRAFT ADVISORY FOR JUST THE
PALM BEACH WATERS THROUGH 8 AM THIS MORNING. THEN SEAS OF 4 FT OR
LESS ARE EXPECTED THROUGH LATE WED BEFORE EVEN LOWERING FURTHER
LATE WEEK AS LIGHT WINDS PREVAIL.
SWAN SHOWS A LONG PERIOD (15 SECONDS) SWELL MOVING THROUGH THE
PROVIDENCE CHANNEL ONSHORE SOUTHERN PALM BEACH COUNTY TUE
AFTERNOON-NIGHT, UP TO 2 FT. THIS IS ORIGINATING FROM
TROPICAL STORM RAFAEL MOVING NNW WELL TO OUR EAST ALONG ABOUT 65
DEGREES WEST LONGITUDE. WILL HAVE TO WATCH THIS FOR A BRIEF PERIOD
OF POTENTIALLY ROUGH SURF/RIP CURRENTS ALONG THE SOUTHERN PALM
BEACH COAST.
FIRE WEATHER...NO CONCERNS AS RH`S REMAIN ELEVATED.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 74 86 71 84 / 10 20 20 40
FORT LAUDERDALE 76 87 74 85 / 10 20 20 40
MIAMI 75 87 73 85 / 10 20 20 40
NAPLES 72 86 71 84 / 20 10 10 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...55/CWC
AREA FORECAST DISCUSSION
NWS MIAMI FL
1135 AM EDT MON OCT 15 2012
.UPDATE...
OUTSIDE OF A FEW MINOR UPDATES WITHIN THE GRIDDED FORECAST
DATABASE BASED ON THE LATEST OBSERVATIONS AND RADAR TRENDS...THE
PREVIOUS FORECAST REMAINS ON TRACK. THE FOG THAT OCCURRED THIS
MORNING ACROSS WESTERN COLLIER COUNTY HAS LIFTED OR BURNED OFF.
THE LATEST SURFACE ANALYSIS SHOWED A COLD FRONT EXTENDING
SOUTHWEST FROM GEORGIA TO LOUISIANA WITH PLENTY OF DRY AIR
OVERSPREADING THE REGION IN ITS WAKE. OUT AHEAD OF THIS BOUNDARY
OVER OUR AREA...MOISTURE AND DEWPOINTS HAVE INCREASED OVER THE
PAST DAY. THE MORNING UPPER SOUNDING IN MIAMI SHOWED A
PRECIPITABLE WATER VALUE OF 1.51 INCHES...WHICH IS FORECAST TO
CONTINUE TO INCREASE SLIGHTLY THROUGH TONIGHT ACROSS THE AREA.
THIS INCREASE IN MOISTURE COMBINED WITH DIURNAL HEATING AND LOCAL
SEA BREEZES WILL BE ENOUGH TO TRIGGER SCATTERED SHOWERS THIS
AFTERNOON AND ISOLATED TSTMS. THE LATEST HRRR AND WRF MODEL
REFLECTIVITIES SHOW SIMILAR RESULTS AND INDICATE MAINLY ISOLATED
TO SCATTERED AFTERNOON COVERAGE FAVORING THE INLAND AND WEST GULF
COAST AREAS TODAY.
THERE WAS A REPORT OF SOME MINOR STREET FLOODING IN THE SOUTH
BEACH AREA ALONG PURDY AVE/20TH STREET DURING THE HIGH TIDE CYCLE
THIS MORNING. THIS IS MOSTLY CONTRIBUTED TO THE PERIGEAN SPRING
TIDE AND WATER LEVELS RUNNING SLIGHT ABOVE NORMAL. EXPECT THIS
POTENTIAL TO CONTINUE AT EACH HIGH TIDE CYCLE THROUGH TUESDAY OR
WEDNESDAY BEFORE SUBSIDING. ALTHOUGH THE THREAT IS LOW...ANY
ADDITIONAL RAINFALL THAT BECOMES CONCENTRATED OVER THESE AREAS MAY
LEAD TO ADDITIONAL FLOODING OR STANDING WATER CONCERNS THROUGH
THIS TIME. THE NEXT HIGH TIDE CYCLE WILL COME LATER THIS EVENING
BETWEEN 8 AND 9 PM. 85/AG
&&
.PREV DISCUSSION... /ISSUED 721 AM EDT MON OCT 15 2012/
AVIATION...
SCATTERED SHOWERS OVER THE ATLANTIC IN MOIST E-NE LOW LEVEL WIND
FLOW WILL AFFECT PORTIONS OF E COAST THROUGH 16Z. THIS WILL KEEP
SHOWERS IN THE VICINITY OF MOST EAST COAST TERMINALS WITH BRIEF MVFR
CONDITIONS POSSIBLE BUT NOT ENOUGH TO PUT IN TAFS. ALONG WEST COAST
AT KAPF, PATCH OF BKN/OVC STRATUS BELOW 1000 FT FORECAST SLOWLY BURN
OFF BY AROUND 13Z, ALTHOUGH WOULDN`T BE SURPRISED IF LOW CEILINGS
LINGER UNTIL PERHAPS 14Z DUE TO LIGHT WINDS AND PERSISTENT NATURE OF
THE CLOUD DECK. SLIGHTLY DRIER AIR WILL TRY TO MOVE INTO SOUTH
FLORIDA AFTER 18Z, BUT WILL KEEP VCSH ALL SITES IN LIGHT NE FLOW.
EXPECT A FEW TSTMS OVER THE INTERIOR OF THE PENINSULA 17Z-00Z BUT THESE
WILL BE ISOLATED ENOUGH TO NOT MENTION AT TAF SITES. GULF SEA BREEZE
FORECAST TO AFFECT KAPF BY 18Z WITH NW WINDS. DRIER N-NE WIND FLOW
00Z-12Z TUESDAY.
PREV DISCUSSION... /ISSUED 345 AM EDT MON OCT 15 2012/
DISCUSSION...
SOME DRIER AIR HAS ALREADY BEGUN TO MOVE INTO THE AREA FROM THE EAST
WITH GPS MET DATA SHOWING THE PWAT DOWN TO 1.5-1.6 INCHES ALONG THE
ATLANTIC COAST BUT STILL 1.8-2.0 INCHES FROM THE LAKE TO NAPLES.
EVEN WITH SOME DRYING FROM THE EAST TODAY, MOISTURE WILL BE
SUFFICIENT, ALONG WITH DEVELOPING SEA BREEZES DUE TO A LIGHTER
SYNOPTIC SCALE WIND FLOW, TO ALLOW FOR SCATTERED SHOWERS TO DEVELOP
ACROSS THE AREA. THE FOCUS IS EXPECTED TO BE ACROSS THE EAST COAST
THROUGH EARLY AFTERNOON, BEFORE SHIFTING TO THE INTERIOR/GULF COAST
LATER IN THE DAY. HAVE GONE WITH THE HIGHEST POPS OVER THE INTERIOR
WHERE THE BEST CONVERGENCE IS EXPECTED. THERE COULD BE A FEW
THUNDERSTORMS AS WELL TODAY, ESPECIALLY OVER THE INTERIOR LATE THIS
AFTERNOON. GFS/ECMWF/SREF ARE IN GENERAL AGREEMENT ON THIS
SCENARIO...AND ACTUALLY OVER THE NEXT FEW DAYS.
ONSHORE WINDS ALONG THE ATLANTIC COAST WILL CONTINUE TO RELAX, BUT
THERE IS STILL A MODERATE RISK OF RIP CURRENTS. THE WEAKER ONSHORE
WINDS MAY PRECLUDE ANY COASTAL FLOODING DESPITE HIGH TIDAL LEVELS.
THIS WILL BE MONITORED OVER THE NEXT COUPLE OF DAYS AS WE ARE IN THE
SPRING TIDE WHICH RESULTS IN HIGHER THAN NORMAL WATER LEVELS.
THIS EVENING AND THROUGH TUESDAY, FURTHER DRYING IS EXPECTED TO
ENTER INTO SOUTH FL FROM THE NORTH. A SHORTWAVE WILL BE PASSING BY
TO THE NORTH TODAY FOLLOWED BY A WEAKENING FRONTAL BOUNDARY MOVING
INTO THE AREA TONIGHT AND BECOMING DIFFUSE OVER OR JUST SOUTH OF THE
AREA ON TUESDAY WHILE WASHING OUT. PWATS ARE FORECAST TO FALL INTO
THE 1.2-1.5 INCH RANGE ON TUESDAY. HOWEVER, LINGERING LOW LEVEL
MOISTURE COULD STILL ALLOW FOR ISOLATED SHOWERS ACROSS THE EAST
COAST, SO KEPT SLIGHT CHANCE POPS EAST HALF FOR TUESDAY.
THE RIP CURRENT RISK ALONG THE ATLANTIC COAST WILL CONTINUE TO
SUBSIDE OVER THE NEXT FEW DAYS. HOWEVER, ONE CAVEAT IS THAT THE
SWAN MODEL IS SHOWING A 15 SECOND EASTERLY SWELL MOVING THROUGH
THE PROVIDENCE CHANNEL OF THE BAHAMAS AND REACHING THE SOUTHERN
PALM BEACH COAST TUE AFTERNOON. GRANTED, RIGHT NOW THE MODEL ONLY
SHOWS A SWELL HEIGHT OF 2 FT, BUT THIS COULD END UP SLIGHTLY
HIGHER. EVEN SO, GIVEN THE LONG PERIOD OF THE SWELL (15 SEC),
ROUGH SURF/DANGEROUS RIP CURRENTS COULD BRIEFLY OCCUR ACROSS SE
PALM BEACH COUNTY ON TUESDAY AFTERNOON/EVENING.
ANOTHER SHORTWAVE DIGS INTO THE GULF AND APPROACHES SOUTH FL ON WED,
WITH MOISTURE INCREASING IN ADVANCE OF THIS TROUGH. SEA BREEZE
CONVERGENCE IS EXPECTED WED, AND WITH THE HIGHER MOISTURE, THERE`S A
BETTER CHANCE OF SHOWERS AND A FEW THUNDERSTORMS ESPECIALLY
INTERIOR-EAST ON WED...DUE TO A MEAN WESTERLY STORM STEERING FLOW.
FOR LATE WEEK INTO NEXT WEEKEND, BOTH GFS/ECMWF SHOW A STRONG CLOSED
MID/UPPER LOW DIVING ACROSS THE GREAT LAKES STATES WITH A TROUGH
EXTENDING SOUTH INTO THE GULF OF MEXICO. BOTH MODELS SHOW WARM,
HUMID CONDITIONS LATE WEEK AHEAD OF THIS SYSTEM AND JUST CANNOT
SHUT MENTION OF SHOWERS/TSTORMS OFF ANY DAY DUE TO SUFFICIENT
MOISTURE/INSTABILITY CONTINUING...ESPECIALLY OVER THE WEEKEND.
BOTH MODELS HAVE BEEN GRADUALLY BACKING OFF ON THE THRUST OF THIS
COLD FRONT FOR SOUTH FLORIDA...ESPECIALLY NOW THE GFS WHICH KEEPS
DEWPOINTS IN THE LOWER 70S ALL THE WAY THROUGH NEXT WEEKEND AND
INTO NEXT WEEK. THE ECMWF SHOWS SLIGHTLY DRIER AIR BEHIND THE
BOUNDARY BY MONDAY...BUT EVEN IT SHOWS WINDS QUICKLY TO THE EAST
BEHIND IT. SO THE BOTTOM LINE IS WARM, HUMID CONDITIONS LOOK TO
PREVAIL THROUGH THE FORECAST PERIOD ALONG WITH DAILY CHANCES OF
SHOWERS/TSTORMS.
MARINE...WINDS ARE CONTINUING TO DECREASE ACROSS THE LOCAL
WATERS. SWAN OUTPUT SHOWS SIG WAVEHEIGHT OF 7 FT EARLY THIS
MORNING OVER THE PALM BEACH WATERS BEFORE DECREASING THROUGHOUT
THE DAY. SO WILL CONTINUE THE SMALL CRAFT ADVISORY FOR JUST THE
PALM BEACH WATERS THROUGH 8 AM THIS MORNING. THEN SEAS OF 4 FT OR
LESS ARE EXPECTED THROUGH LATE WED BEFORE EVEN LOWERING FURTHER
LATE WEEK AS LIGHT WINDS PREVAIL.
SWAN SHOWS A LONG PERIOD (15 SECONDS) SWELL MOVING THROUGH THE
PROVIDENCE CHANNEL ONSHORE SOUTHERN PALM BEACH COUNTY TUE
AFTERNOON-NIGHT, UP TO 2 FT. THIS IS ORIGINATING FROM
TROPICAL STORM RAFAEL MOVING NNW WELL TO OUR EAST ALONG ABOUT 65
DEGREES WEST LONGITUDE. WILL HAVE TO WATCH THIS FOR A BRIEF PERIOD
OF POTENTIALLY ROUGH SURF/RIP CURRENTS ALONG THE SOUTHERN PALM
BEACH COAST.
FIRE WEATHER...NO CONCERNS AS RH`S REMAIN ELEVATED.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 88 74 86 71 / 30 10 20 20
FORT LAUDERDALE 88 76 87 74 / 30 10 20 20
MIAMI 88 75 87 73 / 30 10 20 20
NAPLES 88 72 86 71 / 30 20 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...55/CWC
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
201 AM EDT MON OCT 15 2012
.PREV DISCUSSION... /ISSUED 954 PM EDT SUN OCT 14 2012/
UPDATE...
HAVE MADE SEVERAL MINOR TWEAKS TO GRIDS...MOSTLY TO UPDATE FOR
CURRENT TRENDS BUT ALSO TO TWEAK POPS/WX GRIDS. INITIALLY
DECREASED POPS ESPECIALLY ACROSS THE METRO AREA TO ACCOUNT FOR THE
MOVEMENT OF THE FRONT...THEN INCREASED POPS ACROSS THE NORTH AS
CONVECTION FILLS IN. SPC MESOANALYSIS BARELY BRINGS 100 J/KG
SBCAPE INTO THE AREA AND RAP FORECAST NOT REALLY ANY BETTER...SO
CONTINUED TREND OF LIMITING THUNDER WORDING TO SLIGHT CHANCE WHILE
KEEPING OVERALL POPS LIKELY TO CATEGORICAL. ADDED PATCHY FOG
WORDING AS WELL. WILL BE KEEPING AN EYE ON CONVECTION ALONG THE
FRONT AS CELLS HAVE SHOWN SIGNS OF ROTATION...BUT WITH THE LACK OF
INSTABILITY DO NOT EXPECT ENOUGH UPDRAFTS TO CAUSE CONCERN ACROSS
OUR AREA. UPDATED PRODUCTS WILL BE OUT SHORTLY.
TDP
PREV DISCUSSION... /ISSUED 745 PM EDT SUN OCT 14 2012/
PREV DISCUSSION... /ISSUED 346 PM EDT SUN OCT 14 2012/
SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
VARIABLE CLOUDINESS PREVAILS AT THIS TIME WITH SCATTERED SHOWERS
AND ISOLATED TSTMS IN EAST CENTRAL GA DUE TO ATLANTIC MOISTURE
INTERACTING WITH THE DIURNAL HEATING. OTHERWISE...A LINE OF SHOWERS
AND A FEW TSTMS IN NORTH AL WAS WELL AHEAD OF THE COLD FRONT IN THE
MS RIVER VALLEY. STILL EXPECTING MEASURABLE RAIN OVER NORTHWEST GA
AFTER 800 PM IN ADVANCE OF THE APPROACHING COLD FRONT AND AFTER
MIDNIGHT IN THE ATLANTA AND ATHENS METRO AREAS. THE SHOWERS AND A FEW
TSTMS WILL DIMINISH BY SUNRISE OVER NORTH GA AND CONTINUE MOVING
THROUGH CENTRAL GA ON MONDAY MORNING ENDING BY AFTERNOON. A
SOUTHWEST FLOW ALOFT IN ADVANCE OF THE FRONT WILL ALLOW MODERATE
AMOUNTS OF GULF MOISTURE...PWS AROUND 1.6 INCHES...TO FLOW INTO THE
STATE WITH WEAK INSTABILITY...CAPES AROUND 1000 J/KG. CONSEQUENTLY
EXPECTING NUMEROUS SHOWERS WITH A FEW TSTMS PRIOR TO AND WITH THE
FRONTAL PASSAGE. QPF AMOUNTS OF AROUND ONE HALF INCH CAN BE
ANTICIPATED. HIGH PRESSURE WILL BUILD OVER THE FORECAST AREA ON
MONDAY AFTERNOON WITH A BREEZY NORTHWEST FLOW. COLD AIR ADVECTION
WILL CAUSE MIN TEMPS TO BE AROUND 5 DEGREES BELOW NORMAL FOR MONDAY
NIGHT.
CONTINUED TO LEAN TOWARD THE MET MOS GUIDANCE MORE FOR WEATHER
ELEMENTS THROUGH THE FIRST 18 HOURS BASED ON TIMING OF CONVECTION.
USED A BLEND OF MET/MAV MOS GUIDANCE IN THE 18 TO 36 HOUR RANGE.
16
LONG TERM /TUESDAY THROUGH SUNDAY/...
BIG STORY THROUGH THE LONG TERM CONTINUES TO BE THE COLD FRONT
ANTICIPATED TO PUSH THROUGH THE TENNESSEE VALLEY AND INTO
NORTHWEST GEORGIA EARLY THURSDAY. LATEST ECMWF MORE IN ALIGNMENT
WITH THE GFS WITH REGARDS TO INITIAL TIMING AND STRENGTH...THOUGH
IT CONTINUES TO BE MORE AGGRESSIVE WITH SECONDARY LOW DEVELOPING
OVER EASTERN GEORGIA AND THE CAROLINAS EARLY FRIDAY. THAT BEING
SAID...THE 12Z ECMWF DOES APPEAR LESS ENTHUSIASTIC WITH THE
IMPACTS TO OUR CWA THAN THE PREVIOUS RUNS. GIVEN THE HIGH
UNCERTAINTY THAT SURROUNDS THIS EVENT...HAVE ONLY MADE MINOR
CHANGES TO THE EXTENDED FORECAST. HAVE GONE AHEAD AND INCREASED
POPS FROM SLIGHT CHANCE TO CHANCE ACROSS EASTERN GEORGIA EARLY
FRIDAY DUE TO A SLIGHTLY BETTER MODEL CONSENSUS ON THE PRECIP
DURING THAT TIME. OTHERWISE...HAVE GENERALLY ONLY MADE CHANGES TO
TEMPERATURES AND DEWPOINTS...THOUGH FAIRLY MINOR. THE PREVIOUS
DISCUSSION IS INCLUDED BELOW FOR REFERENCE.
31
/ISSUED 419 AM EDT SUN OCT 14 2012/
IN WAKE OF FROPA SUNDAY NIGHT INTO MONDAY...HIGH PRESSURE WILL
BUILD INTO THE AREA AND ALLOW FOR DRY CONDITIONS INTO MIDWEEK. THE
MAIN FORECAST CONCERN FOR THE LONG TERM WILL BE FROM A SECOND COLD
FRONT PROGGED TO INFLUENCE THE FORECAST AREA ON THURSDAY INTO
FRIDAY. MODEL SOLUTIONS CONTINUE TO HAVE SIGNIFICANT DISCREPANCIES
ON THE TIMING AND PRECIP POTENTIAL WITH THIS FEATURE. THE LATEST
GFS STILL SUGGESTS A MOSTLY DRY PASSAGE COMPARED TO THE
ECMWF...WHICH CONTRASTINGLY DEVELOPS A SECONDARY LOW OVER THE
SOUTHEAST CONUS AND DRAWS IN A MUCH MORE EXPANSIVE MOISTURE FIELD.
THE GFS ALSO IS MUCH MORE PROGRESSIVE THAN THE ECMWF...PUSHING THE
FRONT THROUGH ON THURSDAY MORNING AND AFTERNOON INSTEAD OF THE
LATTER THURSDAY NIGHT INTO FRIDAY SOLUTION. WILL THEREFORE
CONTINUE TO GO WITH A GENERAL BLEND AND INCLUDE SLIGHT TO CHANCE
POPS THROUGH THE PERIOD AND HAVE ISOLATED THUNDER POTENTIAL DURING
THURSDAY INTO THURSDAY NIGHT.
BY NEXT WEEKEND...THE GFS HAS THE UPPER TROUGH EXITING THE
REGION...WHILE THE ECMWF LINGERS AN UPPER CLOSED LOW OVER THE GREAT
LAKES AND HAS THE MAJORITY OF HIGH RH VALUES NORTH OF GEORGIA. IF
THE CLOSED LOW SOLUTION PANS OUT THEN ANY LOBES OF VORTICITY
TRACKING ALONG THE TROUGH WOULD ENHANCE CLOUD COVERAGE OR PRECIP
POTENTIAL. DUE TO THIS LARGE VARIATION AMONG GUIDANCE...WILL GO WITH
A DRY FORECAST THROUGH THE WEEKEND AND WILL MAKE ADJUSTMENTS ONCE
CONFIDENCE INCREASES WITH WEIGHING IN ON MODEL CONSISTENCY OR
CONSENSUS.
GENERALLY STUCK A BIT WARMER THAN MEX GUIDANCE FOR TEMPS AS THE
ECMWF HAS A WARMER SOLUTION THROUGH THE MAJORITY OF THE LONG TERM.
BAKER
&&
.AVIATION...
06Z UPDATE...
MONITORING WHAT IS NOW A BKN LINE OF SHRA AND EMBEDDED
THUNDERSTORMS MOVING INTO NW GEORGIA. CURRENT TIMING HAS LINE
APPROACHING OUTER MOST ATL AREA TERMINALS AT 08Z AND SLOWLY
PUSHING THROUGH BY 12Z. HAVE PREDOMINANT SHRA WITH VCTS AND WILL
MONITOR FOR POSSIBLE TEMPO TSRA AS LINE APPROACHES. LOW CLOUDS TO
FILTER IN FRO A BRIEF TIME BEHIND LINE OF SHOWERS WITH IFR NOW
LIKELY THROUGH 14Z. VFR TO TAKE HOLD AFTER 16Z HOWEVER WITH GUSTY
NW WINDS TO 25 KTS.
//ATL CONFIDENCE...06Z UPDATE...
HIGH ON SHRA OVERNIGHT...LOW ON POSSIBILITY OF TSRA.
HIGH ON CIGS OVERNIGHT.
HIGH ON WINDS MONDAY.
DEESE
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 76 46 74 48 / 50 0 5 10
ATLANTA 74 49 72 52 / 10 0 5 10
BLAIRSVILLE 67 41 69 42 / 10 0 5 10
CARTERSVILLE 73 42 73 46 / 10 0 5 10
COLUMBUS 80 50 76 55 / 30 0 5 10
GAINESVILLE 74 47 70 50 / 10 0 5 10
MACON 82 47 78 48 / 30 0 5 10
ROME 73 42 74 47 / 10 0 5 10
PEACHTREE CITY 77 42 75 46 / 10 0 5 10
VIDALIA 83 54 79 56 / 30 0 5 10
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DEESE
LONG TERM....BAKER
AVIATION...DEESE
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1122 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 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1107 PM MDT SUN OCT 14 2012
VFR CONDITIONS COMBINED WITH LIGHT AND VARIABLE WIND WILL PERSIST FOR
THE NEXT 24 HOURS AT KGLD AND KMCK AS HIGH PRESSURE DRIFTS EAST
AND IS REPLACED BY WEAK LOW PRESSURE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JTL
AVIATION...FS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1054 PM EDT TUE OCT 16 2012
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN ACROSS THE REGION ON WEDNESDAY RIGHT
THROUGH WEDNESDAY NIGHT. THE HIGH WILL MOVE EAST OF THE STATE ON
THURSDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
UPDATE: LAST BIT OF SHOWERS EXITING THE NORTHERN TIER AND CLOUDS
BEGINNING TO BREAK UP. THE CANADIAN GEM AND RUC DOING OK W/SLOWLY
CLEARING THINGS OUT OVERNIGHT. TEMPERATURES HOLDING UP A BIT
LONGER THAN PRECIOUS ANTICIPATED AND THEREFORE, SLOWED UP THE
COOLING PROCESS BY 2 HRS. REST OF THE FCST LOOKS FINE.
PREVIOUS DISCUSSION...
LOW PRES WILL QUICKLY LIFT NORTHEAST AND MOVE AWAY TONIGHT AS HIGH
PRESSURE BUILDS OVER THE STATE. CLEARING THROUGHOUT THE REGION
TONIGHT W/TEMPS DROPPING TO NEAR OR JUST BELOW FREEZING IN MOST
AREAS. HIGH PRESSURE WILL REMAIN OVER THE REGION WEDNESDAY
BRINGING SUNSHINE WITH AFTERNOON TEMPS RANGING FROM THE UPPER 50S
DOWNEAST TO THE LOW 50S OVER THE NORTH. WINDS WILL BE VERY LIGHT
AS THE HIGH CRESTS OVER THE REGION.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
NORTHERN NEW ENGLAND WILL BEGIN THIS FORECAST PERIOD UNDERNEATH AN
UPPER RIDGE. THIS WILL ALLOW FOR ABOVE NORMAL TEMPERATURES AND
DRY WEATHER. HIGH CLOUDS WILL SPILL OVER THE RIDGE AXIS FOR MOSTLY
CLOUDY SKIES. WILL HAVE TO WATCH OUT FOR LOW CLOUDS AND FOG ALONG
THE COASTAL ZONES LATE THURSDAY NIGHT AND EARLY FRIDAY MORNING DUE
TO A STRONG ONSHORE FLOW.
WINDS WILL INCREASE ON FRIDAY AS AN OCCLUDED FRONT APPROACHES FROM
THE WEST. EXPECT RAIN OR RAIN SHOWERS TO DEVELOP DURING THE DAY
ACROSS NORTHERN AND DOWNEAST MAINE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AN OCCLUDED FRONT WILL CROSS THE REGION FRIDAY NIGHT THROUGH
SATURDAY NIGHT...THOUGH UNCERTAINTY STILL EXISTS REGARDING HOW
QUICKLY THE FRONT MOVES EAST OF THE REGION LATER SATURDAY THROUGH
SATURDAY NIGHT. AN AREA OF RAIN WILL CROSS THE REGION IN ADVANCE
OF THE OCCLUSION FRIDAY NIGHT INTO SATURDAY...THEN TAPER TO
SHOWERS IN THE WAKE OF THE FRONT LATER SATURDAY INTO SATURDAY
NIGHT DEPENDENT ON THE TIMING OF THE FRONT. SHOWERS WRAPPING
AROUND THE EXITING SYSTEM COULD BRING A CHANCE OF SHOWERS TO THE
NORTH/MOUNTAINS SUNDAY...WITH PARTLY CLOUDY SKIES DOWNEAST. HIGH
PRESSURE SHOULD THEN BUILD ACROSS THE REGION MONDAY. A COLD FRONT
COULD THEN BRING A CHANCE OF SHOWERS TUESDAY. TEMPERATURES SHOULD
BE AT SLIGHTLY ABOVE NORMAL LEVELS SATURDAY THROUGH MONDAY...WITH
NEAR NORMAL LEVEL TEMPERATURES TUESDAY.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: CONDITIONS WILL IMPROVE TO VFR TONIGHT THEN REMAIN VFR
IN MOSTLY CLEAR SKIES ON WEDNESDAY.
SHORT TERM: MVFR CIGS AND VSBYS ARE POSSIBLE AT KBHB AND KBGR LATE
THURSDAY NIGHT AND EARLY FRIDAY MORNING DUE TO LOW CLOUDS AND FOG.
MVFR CIGS AND VSBYS ARE POSSIBLE FRIDAY AFTERNOON AT ALL TAF SITES
DUE TO LOW CLOUDS AND SHOWERS AS AN OCCLUDED FRONT MOVES INTO THE
REGION. MVFR/IFR CONDITIONS ARE EXPECTED ACROSS THE REGION FRIDAY
NIGHT INTO EARLY SATURDAY NIGHT...WITH MVFR CONDITIONS LATER
SATURDAY NIGHT. OCCASIONAL MVFR CONDITIONS COULD LINGER ACROSS
THE NORTH/MOUNTAINS SUNDAY...WITH VFR CONDITIONS DOWNEAST.
&&
.MARINE...
NEAR TERM: AN SCA WILL CONTINUE OVERNIGHT. WINDS WILL DIMINISH
BY MORNING AS THE HIGH CRESTS OVER THE WATERS.
SHORT TERM: SCA CONDITIONS ARE LIKELY THURSDAY WITH WAVE HEIGHTS IN
THE 4 TO 7 FOOT RANGE AND FRIDAY WITH WAVE HEIGHTS IN THE 6 TO 9
FOOT RANGE AND WIND GUSTS IN EXCESS OF 25 KNOTS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT WEDNESDAY FOR ANZ050>052.
&&
$$
NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1156 PM EDT TUE OCT 16 2012
.SYNOPSIS...
ISSUED AT 345 PM EDT TUE OCT 16 2012
A WARM FRONT WILL LIFT NORTH THROUGH MICHIGAN TONIGHT AND MAY TOUCH
OFF A FEW SHOWERS AND THUNDERSTORMS. IN THE WAKE OF THIS WARM
FRONT... WEDNESDAY WILL BE THE WARMEST DAY OF THE WEEK AS
TEMPERATURES RISE TO NEAR 70. THE WARM UP WILL BE SHORT LIVED
HOWEVER BECAUSE ANOTHER COLD FRONT WILL SWEEP THROUGH THE REGION ON
WEDNESDAY NIGHT AND BRING A WIDESPREAD AREA OF RAIN WITH IT.
COOLER AND SHOWERY WEATHER CAN BE EXPECTED FOR THURSDAY AND FRIDAY
AS A LOW PRESSURE SYSTEM OVER ALBERTA CANADA MOVES SOUTHEAST AND
STALLS OVER THE GREAT LAKES REGION. THAT SYSTEM SHOULD PUSH OUT OF
THE REGION EARLY SATURDAY LEADING TO A PREDOMINATELY DRY PATTERN FOR
THE COMING WEEKEND WITH MODERATING TEMPERATURES.
&&
.UPDATE...
ISSUED AT 657 PM EDT TUE OCT 16 2012
I UPDATED THE GRIDS TO HAVE LIKELY POP ALONG THE ROUTE 10
CORRIDOR THIS EVENING INTO EARLY TONIGHT . THIS IS TO REFLECT THE
CURRENT AREA OF SHOWERS STRENGTHENING THIS EVENING AS IT MOVES
ACROSS THE AREA ( MOSTLY NORTH OF I-96).
AN AREA OF SHOWERS CONTINUES TO DEVELOP AND MOVE EAST NORTHEAST
ACROSS CENTRAL LAKE MICHIGAN (MOSTLY N OF MKE TO MKG LINE) EARLY
THIS EVENING. THIS IS ON THE NOSE A STRENGTHENING LOW LEVEL JET
(40-45 KNOT CORE EAST OF THE QUAD CITIES AT 21Z). THIS AREA WILL
LIKELY INTENSIFY THIS EVENING AS THE LOW LEVEL JET STRENGTHENS
AFTER DARK. WITH THE CORE OF THE JET CROSSING THE GRR AREA AROUND
MIDNIGHT...I WOULD EXPECT MOST OF THE ACTIVITY TO BE NORTH OF
INTERSTATE 96. WITH A DRY SUB CLOUD LAYER SEEN ON THE RAP AND LAPS
SOUNDINGS THIS EVENING... I WOULD EXPECT GUSTY WINDS OUT OF ANY
SHOWER THAT MOVES ACROSS THE AREA UNTIL THE BOUNDARY LAYER EITHER
MOISTENS OR A STRONGER RADIATION INVERSION DEVELOPS. MOST OF THIS
ACTIVITY WILL BE EAST OF THE CWA AFTER 02Z (SHORTWAVE IS EAST OF
THE AREA).
THE INSTABILITY IS MOSTLY AT MID LEVELS AND THE STRONGEST LIFT
NORTH OF MKG IS NEAR THE -20C ISOTHERM AND THAT AREA IS FORECAST
TO BE SATURATED THIS EVENING. SO I WOULD THING THERE SHOULD BE
SOME ISOLATED THUNDERSTORMS WITH THIS AREA SHOWERS TOO.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 345 PM EDT TUE OCT 16 2012
PLUME OF ELEVATED INSTABILITY WITH MID LEVEL LAPSE RATES OF 8-8.5
C/KM OVER IOWA THIS AFTERNOON WILL BE SHIFTING TOWARD SW LWR MI THIS
EVENING... AIDED BY A 45 KT SWLY H8 JET. THAT LOW LEVEL JET IS IN
ADVANCE OF AN H5 SHORTWAVE OVER MN/IA THAT WILL BE PROGRESSING EAST
TOWARD MI. THESE INGREDIENTS SUPPORT A CHANCE OF SHOWERS AND TSTMS
TONIGHT... BUT MOISTURE IS A LIMITING FACTOR WHICH SHOULD LIMIT
COVERAGE. SUSPECT WE WILL BEGIN SEEING SOME HIGHER BASED ACCAS
CLOUDS MOVING IN TOWARD/AFTER SUNSET.
LOOKS LIKE THERE WILL BE A LULL IN PCPN POTENTIAL WEDNESDAY MORNING
INTO THE EARLY AFTERNOON AS THE AFOREMENTIONED SHORTWAVE MOVES OUT
AND THE NEXT WAVE DIVES INTO THE BASE OF THE DIGGING LONGWAVE TROUGH
TO OUR WEST. IT IS THIS WAVE WHICH BRINGS A CATEGORICAL CHANCE FOR
RAIN SHOWERS WEDNESDAY NIGHT. MODELS ARE IN DECENT AGREEMENT ON
TIMING OF THIS FEATURE AND ASSOCIATED SFC FRONT/OCCLUSION PIVOTING
NE THROUGH THE REGION AND PROVIDING A WIDESPREAD SOAKING RAIN.
WHILE RAIN SHOWERS SHOULD END FOR A TIME THURSDAY WITH THE PASSAGE
OF THE COLD FRONT/OCCLUSION... MORE SCATTERED SHOWERS WILL PROBABLY
DEVELOP IN THE AFTERNOON AS THE UPPER LOW AND COLD POOL ALOFT MOVE
IN.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 345 PM EDT TUE OCT 16 2012
RAIN SHOWERS LIKELY TO LINGER FRIDAY BEFORE MOVING OFF FRIDAY NIGHT
AS AN UPPER LOW PROGRESSES TO THE EAST/NORTHEAST. A WEAK RIDGE OF
HIGH PRESSURE WILL MOVE IN FOR THE WEEKEND...WHICH SHOULD KEEP US
MOSTLY DRY SATURDAY THROUGH THE DAY ON MONDAY. AS THE RIDGE OF HIGH
PRESSURE MOVES OFF LATE MONDAY...A MOIST SOUTHWEST FLOW ALOFT WILL
BRING THE POTENTIAL FOR SHOWERS AND MAYBE THUNDERSTORMS LATE MONDAY
NIGHT THROUGH TUESDAY NIGHT.
TEMPERATURES WILL ONLY CLIMB TO AROUND 50 DEGREES ON FRIDAY WITH THE
LINGERING RAIN. GRADUAL WARM UP THROUGH THE WEEKEND...WITH LOWER TO
MID 60S POSSIBLE SUNDAY AND MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1156 PM EDT TUE OCT 16 2012
THE SHORTWAVE THAT CREATED THE SHOWERS THIS EVENING IS MOVING
THROUGH THE AREA NOW AND A FEW MORE LIGHT SHOWERS ARE POSSIBLE
TILL AROUND 09Z. SKIES SHOULD CLEAR AFTER THAT. THERE IS ENOUGH
WIND IN THE BOUNDARY LAYER THAT FOG WILL NOT BE AN ISSUE OVERNIGHT
AFTER THE SKIES DO CLEAR.
THE NEXT SYSTEM WILL BRING RAIN BACK INTO THE AREA DURING THE LATE
AFTERNOON HOURS WEDNESDAY. I COULD SEE IFR CIGS/VSBY NEAR THE LAKE
SHORE WITH MVFR CIGS/VSBY FOR THE AZO...BTL... AND LAN. JXN MAY
HAVE VFR CIGS AND ONLY VERY LIGHT RAIN INTO THE MID EVENING. MOST
OF THE SYSTEMS MOISTURE IS FOCUSED CLOSER TO THE LAKE SHORE
WEDNESDAY EVENING.
&&
.MARINE...
ISSUED AT 345 PM EDT TUE OCT 16 2012
SMALL CRAFT ADVISORIES CONTINUE AS SOUTHERLY LOW LEVEL JET IMPACTS
LK MI. ADDED WATERSPOUTS TO THE FCST BEHIND THE COLD FRONT THURSDAY
AS UPPER COLD POOL MOVES OVERHEAD.
&&
.HYDROLOGY...
ISSUED AT 345 PM EDT TUE OCT 16 2012
THE BAND OF RAIN ON WEDNESDAY NIGHT COULD PRODUCE WIDESPREAD AMOUNTS
OF 0.50 TO 1.0 INCHES. HOWEVER THIS SHOULD HAVE LITTLE IMPACT ON THE
RIVERS WHICH ARE STILL RUNNING LOW EVEN AFTER LAST WEEKEND/S 1.5 TO
3 INCH RAIN EVENT.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THURSDAY FOR LMZ844>849.
&&
$$
UPDATE...WDM
SYNOPSIS...MEADE
SHORT TERM...MEADE
LONG TERM...JMM
AVIATION...WDM
HYDROLOGY...MEADE
MARINE...MEADE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
713 PM EDT TUE OCT 16 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 431 PM EDT TUE OCT 16 2012
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW ZONAL FLOW ALF
OVER THE UPR LKS. SHRTWV EMBEDDED WITHIN THIS FLOW IS MOVING THRU
ONTARIO/MN. COMBINATION OF ISENTROPIC ASCENT BEST DEPICTED ON THE
295-300K SFCS/H7 MSTR CNVGC AND UPR DVGC IN RRQ OF 80KT H3 JET MAX
MOVING THRU SE CANADA IS CAUSING AN AREA OF SHRA OVER THE UPR LKS
THIS AFTN. THE PCPN IS MOST WIDESPREAD OVER THE N AND CNTRL CWA...
WITH DRIER AIR BLO H75 DEPICTED ON THE 12Z GRB RAOB AND MORE
IMPRESSIVE ISENTROPIC ASCENT TO THE N RESTRICTING PCPN COVERAGE OVER
THE SCNTRL. TO THE W...DNVA/MID LVL DRYING/LARGER SCALE QVECTOR DVGC
IN THE WAKE OF THE SHRTWV ARE BRINGING A DRYING TREND IN MN...WITH
THE BACK EDGE OF THE RA AREA PUSHING THRU WRN LK SUP EARLY THIS
AFTN. SKIES ARE MOCLR OVER THE NRN PLAINS INTO MN UNDER THE RDG
TRAILING THE SHRTWV. ANOTHER POTENT SHRTWV EMBEDDED IN THE ZONAL
FLOW ALF IS PUSHING INTO THE NRN ROCKIES. THERE WERE SOME 00Z-12Z H3
HGT FALLS IN EXCESS OF 200M ASSOCIATED WITH THIS DISTURBANCE.
MAIN FCST CONCERNS IN THE SHORT TERM REVOLVE ARND PCPN/CLD TRENDS
THRU THE REST OF THIS AFTN THEN TO POTENTIAL FOR FOG TNGT AS DRIER
AIR ALF OVERSPREADS THE AREA. FOCUS FOR WED TURNS TO PCPN CHCS
ASSOCIATED WITH SHRTWV NOW MOVG THRU THE NRN ROCKIES.
LATE TDAY...BEST H7 MSTR TRANSPORT/UPR DVGC INDICATES THE HEAVIER/
MORE WDSPRD SHRA WL SHIFT INTO THE ERN ZNS WHILE DRYING ALF/LARGER
SCALE QVECTOR DVGC ENDS THE PCPN OVER THE W.
TNGT...EXPECT LINGERING SHRA OVER THE E TO END BY MIDNGT WITH THE
PASSAGE OF THE SHRTWV/ARRIVAL OF DRYING ALF AND DNVA/LARGE SCALE
QVECTOR DVGC. GIVEN THE UPR DRYING/CLD TRENDS...EXPECT CLRG TO
OVERSPREAD THE AREA. WITH LINGERING LLVL MSTR...SUSPECT FOG WL DVLP.
WITH A FAIRLY STEADY SSE WIND...THE BEST CHC FOR MORE WDSPRD/DENSER
FOG AND LO CLDS WL BE OVER THE CNTRL ZNS WHERE THAT FLOW UPSLOPES.
TENDED TOWARD THE LO END OF GUIDANCE FOR MIN TEMPS GIVEN EXPECTED
DRYING ALF...BUT STEADY WIND WL RESTRICT THE FALL FM GOING TOO FAR.
WED...THE AT LEAST THE MRNG SHOULD BE DRY WITH LINGERING DRY AIR/UPR
RDG STILL IN PLACE. BUT STRONG SHRTWV NOW MOVING THRU THE NRN
ROCKIES IS FCST TO CLOSE OFF AND DRIFT INTO FAR NW MN BY 00Z THU. AS
SFC LO MOVES INTO NE MN...ATTENDANT COLD FNT IS PROGGED TO APRCH IWD
LATE IN THE DAY. LOOKS LIKE MOST IMPRESSIVE DPVA/DEEP LYR QVECTOR
CNVGC ASSOCIATED WITH THE SHRTWV WL STAY TO THE NW OF THE AREA WHILE
ANOTHER AREA OF DEEP LYR FORCING/UPR DVGC PASSES WELL TO THE S
CLOSER TO UPR JET AXIS/DEEPER MSTR CNVGC. SO OPTED TO GO NO HIER
THAN CHC POPS OVER THE W HALF OF THE CWA IN THE AFTN...WITH DRY WX
EXPECTED OVER THE E HALF CLOSER TO DEPARTING RDG/DRY AIR. ALTHOUGH
FOG MAY LINGER OVER THE CENTRAL WELL THRU THE MRNG WITH PERSISTENT
UPSLOPE SSE FLOW...RETURN OF MORE SUNSHINE IN THE AFTN WITH H85
TEMPS AS HI AS 10-12C SUG TEMPS WL RISE TO WELL ABV NORMAL. COOLER
CONDITIONS ARE LIKELY OVER THE W WHERE THERE WL BE MORE CLD COVER IN
THE AFTN...BUT SOME MRNG SUNSHINE/DOWNSLOPE S WIND WITH LESS FOG
STILL INDICATE A WARM DAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 431 PM EDT TUE OCT 16 2012
TO BEGIN THE LONG TERM...A DEEP TROF (500MB DEPTH PEAKS THU MORNING
AT 3.5 STANDARD DEVIATIONS FROM THE LONG TERM AVG) WILL BE OVER THE
MID AND UPPER MISSISSIPPI VALLEY. TROF THEN UNRAVELS QUICKLY AND
GETS KICKED NE BY BROAD TROF SETTLING INTO WRN NAMERICA. MEDIUM
RANGE GUIDANCE IS IN POOR AGREEMENT ON THE STRUCTURE/EVOLUTION OF
THE WRN TROF AND STRENGTH/TIMING/TRACKS OF SHORTWAVES EJECTING FROM
TROF. THE GFS RUN-TO-RUN CONSISTENCY FROM LATE WEEKEND INTO EARLY
NEXT WEEK IS IMPROVING WITH LATEST RUNS MORE AGGRESSIVE PUSHING
ENERGY E...FLATTENING DOWNSTREAM RIDGE OVER THE GREAT LAKES/ERN
CONUS AND SHIFTING RIDGE BACK TO THE W. THE ECMWF HAD SHOWN SOMEWHAT
BETTER CONSISTENCY IN DEPICTING A SLOWLY PROGRESSIVE WRN TROF AND A
MORE PRONOUNCED ERN RIDGE THRU EARLY NEXT WEEK. HOWEVER...THE 12Z
ECMWF HAS MADE A BIG SHIFT TOWARD THE GFS IDEA. THRU 12Z MON...THE
GLOBAL GEM/UKMET OFFER OTHER VARYING IDEAS ON THE WRN TROF...BUT
TEND TO LOOK A LITTLE MORE LIKE PREVIOUS ECMWF RUNS. ALL THIS LEADS
TO A VERY LOW CONFIDENCE FCST FOR THE LATTER HALF OF THE LONG TERM
WITH RESPECT TO BOTH TEMPS AND PCPN. GIVEN THE MODEL ISSUES...
TODAY`S LONG TERM FCST WON`T FAVOR ANY SOLUTION IN PARTICULAR THOUGH
IT WOULD SEEM THE 12Z GFS/12Z ECMWF MAY BE WHERE MEDIUM RANGE
GUIDANCE WILL BE HEADING IN UPCOMING RUNS. OVERALL...NEAR NORMAL
TEMPS LATE THIS WEEK SHOULD TREND ABOVE NORMAL BY LATE WEEKEND AND
THEN BEGIN TO FALL BACK CLOSER TO NORMAL. AFTER LINGERING SHRA
CHANCES LATE IN THE WORK WEEK WITH DEPARTING TROF...DEVELOPING GREAT
LAKES/ERN RIDGE SHOULD INITIALLY LEAD TO DRIER WEATHER OVER THE
WEEKEND BEFORE PCPN CHANCES RETURN MON/TUE.
BEGINNING WED NIGHT...TROF WILL BE APPROACHING MAX DEPTH AS 500MB
LOW CLOSES OFF IN THE VCNTY OF NE IA. SFC WAVE WILL DEVELOP/DEEPEN
AND ROTATE THRU ERN WI TOWARD NW WI/WRN UPPER MI OVERNIGHT.
AHEAD OF FRONT/SFC WAVE...WARM CONVEYOR PCPN WILL SWING ACROSS UPPER
MI. NICE DIRECTIONALLY DIFFLUENT UPPER LEVEL FLOW OVERTOP SHARPENING
850MB FRONT WILL AID THE PCPN. LIKELY/CATEGORICAL POPS SPREADING
ACROSS THE AREA APPEARS REASONABLE. CLOUDS/PCPN WILL HOLD MIN TEMPS
IN THE 40S...AND POSSIBLY AROUND 50 E.
WARM CONVEYOR PCPN SHOULD ROTATE OUT OF THE AREA THU...BUT DEEP
CYCLONIC FLOW AND INDICATIONS OF SHORTWAVE PIVOTING AROUND MID LEVEL
LOW TOWARD UPPER MI WILL WORK TO KEEP PCPN CHANCES OVER THE AREA
THRU THE DAY. ABUNDANT CLOUD COVER AND WEAK CAA WILL LIMIT DIURNAL
TEMP RISE. EXPECT HIGHS IN THE UPPER 40S TO MID 50S.
THU NIGHT/FRI...ENTIRE SYSTEM WEAKENS RATHER QUICKLY AND FOCUSED
PCPN SHOULD DIMINISH AS LOW/MID LEVEL WIND FIELDS WEAKEN
DRAMATICALLY. IN FACT...MUCH OF THE GUIDANCE SUGGESTS A TREND TOWARD
MOSTLY DRY LATER THU NIGHT INTO FRI. HOWEVER...WHILE ORGANIZED PCPN
AREAS WILL DIMINISH THU NIGHT...PROXIMITY OF THE CENTER OF WEAKENING
MID LEVEL LOW SUGGESTS MAINTAINING CHC/SLIGHT CHC POPS THU
NIGHT/FRI. MAY END UP BEING MORE OF A DRIZZLE SITUATION WITH PATCHY
-RA. DIURNAL TEMP SWING THU NIGHT/FRI SHOULD CONTINUE TO BE LIMITED
BY CLOUDS AND ALSO BY LITTLE TEMP ADV.
AS WEAKENING SYSTEM BEGINS TO ACCELERATE TO THE NE SAT...WILL OPT
FOR A DRY DAY. BEST SHOT FOR A DRY DAY WILL BE SUN AS AMPLIFYING
RIDGE AXIS DOWNSTREAM OF DEVELOPING WRN TROF SHIFTS ACROSS THE UPPER
LAKES. SUN WILL BE THE WARMEST DAY...WITH MID 50S E AND PERHAPS
AROUND 60F OVER THE W
AS MENTIONED ABOVE...THERE IS VERY LOW CONFIDENCE IN FCST FOR EARLY
NEXT WEEK. EXPECT A CHC OF PCPN AT SOME POINT SUN NIGHT INTO TUE AS
COLD FRONT SLIPS THRU THE AREA. THE 12Z ECMWF/GFS SUGGEST LIMITED
PCPN CHC THAT WILL BE CONFINED MAINLY TO MON OVER THE SCNTRL AND E.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 710 PM EDT TUE OCT 16 2012
CONDITIONS SHOULD BE VFR INTO EARLY EVNG AFTER ANY PCPN ENDS...THEN
EXPECT SOME FOG/LO CLD TO DVLP OVERNGT WITH NOCTURNAL COOLING OF THE
FAIRLY MOIST LLVLS UNDER THE DRYING ALF. THE BEST CHC FOR IFR AND
EVEN LIFR CONDITIONS WL BE AT SAW...WITH FAVORABLE UPSLOPE SSE WIND.
ONSET OF DAYTIME HEATING/MIXING ON WED WL BREAK UP ANY FOG/LO CLD
THAT DEVELOPS. VFR CONDITIONS WILL THEN CONTINUE THROUGH THE REST OF
THE TAF PERIOD WITH LIGHT RAIN STARTING TO COME IN LATE WED
AFTERNOON.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 431 PM EDT TUE OCT 16 2012
EXPECT S WINDS UP TO 25-30 KTS OVER THE E HALF TO DIMINISH A BIT
TONIGHT WITH THE ARRIVAL OF A WEAKER PRES GRADIENT. SE WINDS UP TO
25 KTS WILL CONTINUE ON WED IN ADVANCE OF AN APPROACHING DEEP LO
PRES CENTER. THE STRONGEST WINDS WILL BE OVER THE E HALF AGAIN WHERE
THE TERRAIN TENDS TO ENHANCE THESE WINDS.
DEEPENING SFC LOW ROTATING NW THRU NRN WI WED NIGHT WILL RESULT IN
AN INCREASE IN E TO SE WINDS ACROSS LAKE SUPERIOR. NOT OUT OF THE
QUESTION THAT SOME GALE FORCE GUSTS COULD DEVELOP LATE IN THE NIGHT
FROM AROUND WHITEFISH PT TO AROUND ISLE ROYALE. WINDS WILL THEN
DIMINISH DURING THE DAY THU AS LOW PRES WEAKENS. BY THU AFTN...WINDS
SHOULD BE UNDER 15KT OVER WRN LAKE SUPERIOR AND DOWN TO 15 TO 25KT
OVER CNTRL AND ERN LAKE SUPERIOR. BEYOND THU...NO SIGNIFICANT
WEATHER SYSTEMS ARE EXPECTED TO AFFECT THE UPPER LAKES THRU THE
WEEKEND. IN FACT...WEAK PRES GRADIENT MAY LEAD TO A PERIOD OF LIGHT
WINDS UNDER 15KT OVER MUCH OF LAKE SUPERIOR FRI THRU SUN.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...ROLFSON
AVIATION...07
MARINE...KC/ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
416 PM EDT MON OCT 15 2012
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 414 PM EDT MON OCT 15 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH EAST
OF LAKE HURON LEAVING MAINLY ZONAL FLOW TO THE WEST FROM THE PAC NW TO
THE UPPER MS VALLEY. AN UPSTREAM SHORTWAVE TROUGH WAS MOVING FROM
THE NRN ROCKIES INTO THE NRN PLAINS. AT THE SFC...A RIDGE WAS
BUILDING ACROSS WRN LAKE SUPERIOR AND W UPPER MI. SRLY WINDS WERE
INCREASING OVER MN AHEAD OF A TROUGH FROM SRN MANITOBA INTO THE
CNTRL DAKOTAS. VIS LOOP SHOWED CLEARING SKIES OVER THE W HALF OF
UPPER MI. HOWEVER...HIGH CLOUDS SUPPORTED BY WAA AHEAD OF THE TROUGH
WERE QUICKLY STREAMING FROM MN INTO WRN WI. SOME LIGHT RAIN HAD ALSO
DEVELOPED FROM NEAR WINNIPEG INTO NW MN WITH WAA/ISENTROPIC LIFT
AHEAD OF THE TROUGH.
THE MODELS WERE IN GOOD AGREEMENT WITH THE MID LEVEL TROUGH DIGGING
FROM THE NRN PLAINS INTO THE UPPER MS VALLEY TONIGHT INTO TUE.
EXPECT THE AREA OF RAIN TO THE WEST TO EXPAND LATE TONIGHT AND
SPREAD INTO THE WRN CWA AS 925-850 MB MOISTURE TRANSPORT AND
295-300K ISENTROPIC LIFT INCREASE. AS THE 850-700 MB WARM FRONT
MOVES THROUGH THE AREA TUE...PCPN WILL SPREAD ACROSS THE CWA.
ALTHOUGH LIKELY-CATEGORICAL POPS WERE WARRANTED...THE HEAVIER PCPN
(INTO THE 0.25 TO 0.50 RANGE) IS EXPECTED MAINLY ACROSS THE NORTH
AND EAST FROM THE KEWEENAW INTO THE ERN CWA WHERE THE STRONGEST LIFT
AHEAD OF THE 850 MB WARM FRONT IS PROGGED....PER NAM/REGIONAL-GEM.
MODELS TIMING HAS ALSO BEEN CONSISTENT WITH THE PCPN ENDING OVER THE
WEST BY EARLY AFTERNOON AND OVER THE EAST LATE.
TEMPS WILL DROP INTO THE LOW TO MID 30S THIS EVENING BEFORE THE
CLOUDS THICKEN AND SRLY WINDS INCREASE RESULTING IN SLOWLY CLIMBING
TEMPS OVERNIGHT. AS THE PCPN ENDS TUE AFTERNOON...WAA WILL ALSO DRAW
ENOUGH WARM AIR INTO THE REGION TO PUSH MAX READINGS INTO UPPER 50S
WEST WHILE TEMPS LINGER AROUND 50 OVER THE EAST.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 414 PM EDT MON OCT 15 2012
MID WEEK WILL REMAIN UNSETTLED AS A DEEP UPPER TROUGH OVER THE
CANADIAN PRAIRIE PROVINCES CLOSES OFF OVER THE UPPER MIDWEST/GREAT
LAKES. THIS WILL ALLOW FOR PRECIPITATION CHANCES THROUGH THURSDAY
WITH AT OR SLIGHTLY BELOW NORMAL TEMPERATURES.
FOR THE DETAILS...EXPECT THE WARM ADVECTION/ISENTROPIC LIFT PCPN
ASSOCIATED WITH THE 850MB WARM FRONT TO MOVE EAST OF THE FORECAST
AREA TUESDAY NIGHT...LEADING TO THE AREA BEING IN THE WARM SECTOR
AHEAD OF THE DEEP SFC LOW AND OCCLUDED FRONT EXTENDING FROM LAKE
WINNIPEG INTO THE PLAINS. WILL MAINTAIN LOW CHANCE POPS IN THE
EVENING EAST OF MARQUETTE DUE TO CONTINUED WEAK ISENTROPIC LIFT AND
MID LVL Q-VECT CONVERGENCE. LOW CLOUDS/FOG WILL REMAIN A CONCERN
OVERNIGHT DUE TO CLEARING SKIES AND LEFTOVER LOW LEVEL MOISTURE FROM
AFTN/EVENING RAINFALL AND AS SUCH HAVE MAINTAINED FOG CHANCES.
THE OCCLUDED FRONT WILL MOVE EAST ON WEDNESDAY AS THE UPPER SYSTEM
CLOSES OFF. EXPECT A BAND OF SHOWERS TO MOVE INTO THE WESTERN U.P.
WEDNESDAY AFTERNOON ASSOCIATED WITH PRECIPITABLE WATER VALUES IN
EXCESS OF 1 INCH AND MID LVL Q-VECTOR CONVERGENCE. DUE TO THE LOW
CLOSING OFF...THE BAND OF SHOWERS WILL ONLY SLOWLY MOVE EAST WED
AFTN/NIGHT. IN FACT...THERE WILL LIKELY BE A PROLONGED PERIOD OF
STEADY RAIN WED EVENING ACROSS UPPER MICHIGAN DUE TO THE ROTATION
AND TIGHTENING OF THE 850MB ISOTHERMS CONTRIBUTING TO INCREASED
FN/FS VECTOR CONVERGENCE IN THE TROWAL REGION. WILL THEREFORE
MAINTAIN LIKELY POPS ACROSS THE ENTIRE U.P. WED NIGHT.
TRICKY AND UNCERTAIN FORECAST FOR THURSDAY. THE ECMWF SUGGESTS THAT
MOST OF THE U.P. WILL BE DRY WITH THE COMMA HEAD MOISTURE/PCPN BACK
INTO MN AND NW WISCONSIN DUE TO THE UPPER LOW BEING FURTHER WEST
THAN THE GFS WHICH HAS THE UPPER LOW OVERHEAD. AM THINKING THAT THE
BEST CHANCES FOR PCPN WILL BE ACROSS THE WEST AND HAVE OPTED TO
MAINTAIN HIGH CHANCE POPS FOR THAT AREA. DUE TO SIGNIFICANT
UNCERTAINTY...WILL STILL NEED TO MAINTAIN CHANCE POPS TO THE EAST.
CONFIDENCE IN THE EXTENDED FORECAST FOR FRIDAY-MONDAY STILL QUITE
LOW WITH DIFFERENCES BETWEEN THE ECWMF...GFS AND CANADIAN IN HOW
FAST THE GREAT LAKES CLOSED LOW EJECTS TO THE NORTHEAST. TEND TO
BELIEVE THE SLOWER ECMWF SOLUTION WHICH WOULD KEEP A DRIER FORECAST
FOR THE UPPER LAKES FOR THE WEEKEND DUE TO UPPER RIDGING HANGING ON
ACROSS THE UPPER MIDWEST. THE BELOW CONFIDENCE FORECAST NOT ONLY
APPLIES TO PRECIPITATION CHANCES...BUT ALSO TO TEMPERATURES AS THE
ECMWF WOULD BE WARMER COMPARED TO THE CLOUDY/COOL GFS.
WITH ALL OF THIS SAID...WILL TREND TOWARD THE 00Z AND 12Z ECMWF AND
LOWER POPS TO SLIGHT CHANCE OR LOW CHANCE POPS EACH DAY IN THE
EXTENDED. IN FACT IF THE 00Z ECMWF VERIFIES IT WILL END UP BEING A
DECENT WEEKEND. ON THE OTHER HAND...IF THE GFS VERIFIES IT COULD BE
MUCH WETTER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 143 PM EDT MON OCT 15 2012
EXPECT CONDITIONS TO IMPROVE TO VFR AT CMX AND SAW BY LATE AFTERNOON
AS A RIDGE WITH BACKING WINDS AND DRIER AIR MOVES INTO THE REGION.
ANOTHER TROUGH WILL MOVE TOWARD THE AREA TONIGHT BRINGING THICKENING
CLOUDS AND THE POTENTIAL FOR SOME LIGHT RAIN LATE TONIGHT. EXPECT
RAIN WITH MVFR CIGS TO MOVE IN TUESDAY...WITH CIGS BLO 2K FT MORE
LIKELY AT CMX AND SAW WITH LOCAL SE OR SRLY FLOW THAT FAVORS LOWER
CIGS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 414 PM EDT MON OCT 15 2012
WINDS WILL CONTINUE TO DIMINISH THIS EVENING AS HIGH PRES BUILDS
INTO THE REGION. ANOTHER LOW PRESSURE TROUGH APPROACHING THE UPPER
GREAT LAKES LATE TONIGHT WILL RESULT IN SOUTH WINDS OF 15 TO 25 KT
WITH AREAS TO NEAR 30 KT OVER ERN LAKE SUPERIOR LATE TUE AFTERNOON
AND EVENING. A DEEPER LOW PRESSURE SYSTEM MOVING INTO THE UPPER GREAT LAKES
ON THURSDAY COULD CAUSE AN INCREASE IN ERLY WINDS TO 30 KT LATE WED
NIGHT INTO THURSDAY. OTHERWISE...WINDS IN THE VICINITY OF THE LOW
SHOULD GENERALLY REMAIN LESS THAN 20 KTS WEDNESDAY THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...MRD
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
144 AM EDT MON OCT 15 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 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 143 AM EDT MON OCT 15 2012
THE RAIN IS STARTING TO MOVE EAST...AND THE TERMINALS ARE CURRENTLY
MVFR. EXPECT CONDITIONS TO IMPROVE TO VFR AT IWD AND CMX BY MORNING
WITH CONTINUED VFR CONDITIONS AT THOSE SITES THROUGH THE DAY. AT
SAW...THE N WINDS SHOULD ALLOW FOR MVFR CIGS TO CONTINUE THROUGH
MONDAY MORNING BEFORE SCOURING OUT BY MONDAY AFTN. COULD SEE AN MVFR
VSBY RESTRICTION AT SAW WITH ANY RAIN...BUT THE HEAVIEST RAIN IS
LIKELY OVER SO EVEN THAT IS UNLIKELY. GUSTY N WINDS WILL PERSIST AT
SAW AND CMX OVERNIGHT WITH A FEW GUSTS CLOSE TO 30 KT POSSIBLE.
HOWEVER...THOSE WINDS SHOULD SUBSIDE AS THE LOW MOVES NORTHEAST.
&&
.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 THIS MORNING FOR LSZ249>251-266-267.
LAKE MICHIGAN...
GALE WARNING UNTIL 11 AM EDT THIS MORNING FOR LMZ221-250.
&&
$$
UPDATE...MRD
SHORT TERM...TITUS
LONG TERM...JLB
AVIATION...MRD
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1232 PM CDT MON OCT 15 2012
.AVIATION...
18Z TAFS FOR KOMA...KLNK...AND KOFK.
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF CYCLE. A FRONT WILL
BRING A FEW MID-LEVEL CLOUDS...BUT MORE IMPORTANTLY...A SHIFT
FROM SOUTHERLY WINDS AT OR BELOW 10KT TO NORTHWESTERLY WINDS
GUSTING TO AROUND 22-25KT BY LATE TUESDAY MORNING.
MAYES
&&
.PREV DISCUSSION... /ISSUED 332 AM CDT MON OCT 15 2012/
DISCUSSION...
MAIN FORECAST CHALLENGE WILL BE HIGH TEMPERATURES OVER THE NEXT
COUPLE DAYS AND PRECIPITATION CHANCES TUESDAY NIGHT INTO MID
WEEK.
LATEST WATER VAPOR IMAGERY AND RAP 500MB ANALYSIS SHOWS THE NATIONS
MID SECTION IN NORTHWEST FLOW LYING IN BETWEEN A TROUGH TO OUR
EAST AND A WEAK RIDGE TO THE WEST. SHORTWAVE ENERGY CURRENTLY OVER
THE NORTHWEST CONUS IS FORECAST TO RIDE DOWN THE WEAK RIDGE AND
TOWARD CENTRAL NEBRASKA BY 06Z TONIGHT. AS WEAK SFC LOW PRESSURE
MOVES ACROSS THE NRN PLAINS AHEAD OF THIS UPPER SHORTWAVE...THE
FORECAST AREA WILL BE UNDER WEAK SOUTHERLY SFC FLOW. COMBINED WITH
LOW LEVEL WARM AIR ADVECTION THROUGHOUT THE DAY...TODAY WILL BE
VERY MILD WITH HIGHS APPROACHING UPPER 70S TO NEAR 80. STRONGER
MIXING IS LIKELY ON TUESDAY AHEAD OF AN APPROACHING COOL FRONT IN
ADVANCE OF ABOVE MENTIONED UPPER LEVEL SHORTWAVE. HIGHS SHOULD
APPROACH 80 ONCE AGAIN WITH SLIGHTLY COOLER READINGS IN OUR FAR
NORTHERN COUNTIES BEHIND THE COOL FRONT.
A STRONGER UPPER LEVEL SHORTWAVE TROUGH WILL PUSH ACROSS MONTANA AND
CLOSE OFF AS IT SKIRTS THE NORTH DAKOTA/CANADIAN BORDER MID WEEK.
THIS WILL PUSH A STRONGER COLD FRONT INTO THE FORECAST AREA BY
WEDNESDAY MORNING. INCREASING MOISTURE AND FRONTOGENETICAL FORCING
SHOULD BE ENOUGH TO GENERATE LIGHT PCPN BEHIND THE SURFACE FRONT
THROUGH THE DAY WEDNESDAY. INCREASING PRESSURE GRADIENT BEHIND THE
BOUNDARY WILL CREATE BREEZY IF NOT WINDY CONDITIONS THROUGH THE
DAY WEDNESDAY.
THE UPPER CLOSED LOW WILL CONTINUE TO SINK SOUTHEAST AND DEEPEN AS
IT MOVES INTO THE GREAT LAKES REGION LATE IN THE SCHOOL/WORK WEEK.
DEPENDING ON LOCATION AND TIMING...AREA COULD SEE RAIN SHOWERS SINK
SOUTH INTO THE CWA AROUND THE BACKSIDE OF THE UPPER LOW. ALREADY HAD
POPS GOING FOR THURSDAY SO WILL CONTINUE. ALSO LOOKS AS THOUGH SFC
PRESSURE GRADIENT WILL REMAIN QUITE STRONG WHILE 850MB NORTHWEST
WINDS ARE FORECAST AROUND 45-55KTS. SOME OF THIS WOULD LIKELY MIX
DOWN AND CREATE QUITE BLUSTERY CONDITIONS THROUGH LATE WEEK.
QUIET AND WARMER CONDITIONS ARE EXPECTED INTO THE WEEKEND.
KERN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
618 AM CDT MON OCT 15 2012
.AVIATION...12Z TAFS FOR KOMA...KLNK AND KOFK. VFR CONDITIONS
EXPECTED THROUGH THE PERIOD WITH WINDS GENERALLY 10KTS OR LESS.
COULD SEE A SMALL WINDOW AT KOFK WITH WINDS OF 12 TO 15KTS BY LATE
MORNING THROUGH THE AFTERNOON. A SURFACE TROUGH APPROACHES THE
AREA LATE TONIGHT...WITH A WIND SHIFT TO THE NORTHWEST EXPECTED AT
KOFK BY 10Z...AND NOT UNTIL TUESDAY MORNING BY 15 TO 18Z JUST
BEYOND THIS TAF PERIOD.
&&
.PREV DISCUSSION... /ISSUED 332 AM CDT MON OCT 15 2012/
DISCUSSION...
MAIN FORECAST CHALLENGE WILL BE HIGH TEMPERATURES OVER THE NEXT
COUPLE DAYS AND PRECIPITATION CHANCES TUESDAY NIGHT INTO MID
WEEK.
LATEST WATER VAPOR IMAGERY AND RAP 500MB ANALYSIS SHOWS THE NATIONS
MID SECTION IN NORTHWEST FLOW LYING IN BETWEEN A TROUGH TO OUR
EAST AND A WEAK RIDGE TO THE WEST. SHORTWAVE ENERGY CURRENTLY OVER
THE NORTHWEST CONUS IS FORECAST TO RIDE DOWN THE WEAK RIDGE AND
TOWARD CENTRAL NEBRASKA BY 06Z TONIGHT. AS WEAK SFC LOW PRESSURE
MOVES ACROSS THE NRN PLAINS AHEAD OF THIS UPPER SHORTWAVE...THE
FORECAST AREA WILL BE UNDER WEAK SOUTHERLY SFC FLOW. COMBINED WITH
LOW LEVEL WARM AIR ADVECTION THROUGHOUT THE DAY...TODAY WILL BE
VERY MILD WITH HIGHS APPROACHING UPPER 70S TO NEAR 80. STRONGER
MIXING IS LIKELY ON TUESDAY AHEAD OF AN APPROACHING COOL FRONT IN
ADVANCE OF ABOVE MENTIONED UPPER LEVEL SHORTWAVE. HIGHS SHOULD
APPROACH 80 ONCE AGAIN WITH SLIGHTLY COOLER READINGS IN OUR FAR
NORTHERN COUNTIES BEHIND THE COOL FRONT.
A STRONGER UPPER LEVEL SHORTWAVE TROUGH WILL PUSH ACROSS MONTANA AND
CLOSE OFF AS IT SKIRTS THE NORTH DAKOTA/CANADIAN BORDER MID WEEK.
THIS WILL PUSH A STRONGER COLD FRONT INTO THE FORECAST AREA BY
WEDNESDAY MORNING. INCREASING MOISTURE AND FRONTOGENETICAL FORCING
SHOULD BE ENOUGH TO GENERATE LIGHT PCPN BEHIND THE SURFACE FRONT
THROUGH THE DAY WEDNESDAY. INCREASING PRESSURE GRADIENT BEHIND THE
BOUNDARY WILL CREATE BREEZY IF NOT WINDY CONDITIONS THROUGH THE
DAY WEDNESDAY.
THE UPPER CLOSED LOW WILL CONTINUE TO SINK SOUTHEAST AND DEEPEN AS
IT MOVES INTO THE GREAT LAKES REGION LATE IN THE SCHOOL/WORK WEEK.
DEPENDING ON LOCATION AND TIMING...AREA COULD SEE RAIN SHOWERS SINK
SOUTH INTO THE CWA AROUND THE BACKSIDE OF THE UPPER LOW. ALREADY HAD
POPS GOING FOR THURSDAY SO WILL CONTINUE. ALSO LOOKS AS THOUGH SFC
PRESSURE GRADIENT WILL REMAIN QUITE STRONG WHILE 850MB NORTHWEST
WINDS ARE FORECAST AROUND 45-55KTS. SOME OF THIS WOULD LIKELY MIX
DOWN AND CREATE QUITE BLUSTERY CONDITIONS THROUGH LATE WEEK.
QUIET AND WARMER CONDITIONS ARE EXPECTED INTO THE WEEKEND.
KERN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
DEWALD
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
332 AM CDT MON OCT 15 2012
.DISCUSSION...
MAIN FORECAST CHALLENGE WILL BE HIGH TEMPERATURES OVER THE NEXT
COUPLE DAYS AND PRECIPITATION CHANCES TUESDAY NIGHT INTO MID
WEEK.
LATEST WATER VAPOR IMAGERY AND RAP 500MB ANALYSIS SHOWS THE NATIONS
MID SECTION IN NORTHWEST FLOW LYING IN BETWEEN A TROUGH TO OUR
EAST AND A WEAK RIDGE TO THE WEST. SHORTWAVE ENERGY CURRENTLY OVER
THE NORTHWEST CONUS IS FORECAST TO RIDE DOWN THE WEAK RIDGE AND
TOWARD CENTRAL NEBRASKA BY 06Z TONIGHT. AS WEAK SFC LOW PRESSURE
MOVES ACROSS THE NRN PLAINS AHEAD OF THIS UPPER SHORTWAVE...THE
FORECAST AREA WILL BE UNDER WEAK SOUTHERLY SFC FLOW. COMBINED WITH
LOW LEVEL WARM AIR ADVECTION THROUGHOUT THE DAY...TODAY WILL BE
VERY MILD WITH HIGHS APPROACHING UPPER 70S TO NEAR 80. STRONGER
MIXING IS LIKELY ON TUESDAY AHEAD OF AN APPROACHING COOL FRONT IN
ADVANCE OF ABOVE MENTIONED UPPER LEVEL SHORTWAVE. HIGHS SHOULD
APPROACH 80 ONCE AGAIN WITH SLIGHTLY COOLER READINGS IN OUR FAR
NORTHERN COUNTIES BEHIND THE COOL FRONT.
A STRONGER UPPER LEVEL SHORTWAVE TROUGH WILL PUSH ACROSS MONTANA AND
CLOSE OFF AS IT SKIRTS THE NORTH DAKOTA/CANADIAN BORDER MID WEEK.
THIS WILL PUSH A STRONGER COLD FRONT INTO THE FORECAST AREA BY
WEDNESDAY MORNING. INCREASING MOISTURE AND FRONTOGENETICAL FORCING
SHOULD BE ENOUGH TO GENERATE LIGHT PCPN BEHIND THE SURFACE FRONT
THROUGH THE DAY WEDNESDAY. INCREASING PRESSURE GRADIENT BEHIND THE
BOUNDARY WILL CREATE BREEZY IF NOT WINDY CONDITIONS THROUGH THE
DAY WEDNESDAY.
THE UPPER CLOSED LOW WILL CONTINUE TO SINK SOUTHEAST AND DEEPEN AS
IT MOVES INTO THE GREAT LAKES REGION LATE IN THE SCHOOL/WORK WEEK.
DEPENDING ON LOCATION AND TIMING...AREA COULD SEE RAIN SHOWERS SINK
SOUTH INTO THE CWA AROUND THE BACKSIDE OF THE UPPER LOW. ALREADY HAD
POPS GOING FOR THURSDAY SO WILL CONTINUE. ALSO LOOKS AS THOUGH SFC
PRESSURE GRADIENT WILL REMAIN QUITE STRONG WHILE 850MB NORTHWEST
WINDS ARE FORECAST AROUND 45-55KTS. SOME OF THIS WOULD LIKELY MIX
DOWN AND CREATE QUITE BLUSTERY CONDITIONS THROUGH LATE WEEK.
QUIET AND WARMER CONDITIONS ARE EXPECTED INTO THE WEEKEND.
KERN
&&
.AVIATION...
06Z TAFS FOR KOFK...KLNK AND KOMA.
VFR CONDITIONS ARE FORECAST THROUGH MONDAY EVENING. HIGH PRESSURE
WILL MOVE EAST OF EASTERN NEBRASKA MONDAY. LIGHT WINDS AND CLEAR
SKIES OVERNIGHT WILL BECOME SOUTH AND SOUTHWEST NEAR 10KT WITH
SCATTERED TO BROKEN HIGH CLOUDS DURING THE DAY MONDAY.
DERGAN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BUFFALO NY
937 PM EDT TUE OCT 16 2012
.SYNOPSIS...
MAINLY CLEAR SKIES THIS EVENING WILL GIVE-WAY TO INCREASING MID
LEVEL CLOUDS WHICH ARE ASSOCIATED WITH A WARM FRONT. EXPECT
MAINLY DRY CONDITIONS WEDNESDAY AND WARMER WITH AFTERNOON HIGH
TEMPERATURES CLIMBING INTO THE 60S...AND A FEW LOWER 70S. OUR AREA
WILL REMAIN ON THE MILD SIDE INTO THURSDAY...BEFORE A GUSTY COLD
FRONT AND SHOWERS CROSSES THE AREA THURSDAY AFTERNOON AND EVENING.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
IR SATELLITE IMAGERY SHOWS MUCH OF THE LAKE EFFECT CLOUDS HAVE
DISSIPATED BY LATE EVENING...EXCEPT FOR A SMALL AREA LINGERING
EAST OF LAKE ONTARIO. THESE CLOUDS SHOULD ALSO DISSIPATE AS THE
NIGHT GOES ON. THIS CLEARING HAS ALLOWED TEMPERATURES TO DROP
RATHER QUICKLY DURING THE EVENING HOURS...SO HAVE NUDGED THE LOW
TEMPERATURE FORECAST A TAD LOWER. LOWS WILL LARGELY BE REACHED
TOWARD MIDNIGHT...BUT THEN TEMPERATURES SHOULD LEVEL OFF AS MID-
HIGH CLOUDS APPROACHING FROM THE SOUTHWEST SPREAD ACROSS THE
REGION. THESE CLOUDS ARE ASSOCIATED WITH A WARM FRONT...AND CAN
ALREADY BE SEEN ACROSS LAKE ERIE LATE THIS EVENING.
LOWS SHOULD RANGE FROM THE LOWER TO MID 30S IN THE TYPICALLY
COLDER INTERIOR VALLEYS...TO AROUND 40 CLOSER TO THE LAKE SHORES.
A HIGH PRESSURE RIDGE WILL EXTEND FROM THE APPALACHIANS AND INTO
WESTERN NEW YORK OVERNIGHT. MEANWHILE...A WARM FRONT WILL BRUSH WESTERN
PORTIONS OF NEW YORK TOWARDS DAWN...BUT WITH DEEP MOISTURE ALSO
LINGERING TO OUR WEST...EXPECT THE BULK OF THE REGION TO REMAIN
DRY LATE OVERNIGHT AND TOMORROW WITH THE WARM FRONT. THE HRRR IS
COMING IN RIGHT IN LINE WITH OTHER MODEL GUIDANCE...SUGGESTING
SOME LIGHT SHOWERS OR SPRINKLES CLIPPING FAR NW PORTIONS OF THE
STATE EARLY WEDNESDAY MORNING.
WITH THE WARM FRONT LIFTING INTO CANADA WEDNESDAY...OUR REGION WILL
FALL INTO THE WARM SECTOR. TEMPERATURES ALOFT AT 850 HPA WILL CLIMB
TOWARDS +10 TO +12C ACROSS OUR REGION. HOWEVER WE MIGHT NOT MIX UP TO
THIS LEVEL...AND WILL USE 925 HPA TEMPERATURES INSTEAD TO FORECAST
HIGHS FOR WEDNESDAY. AT 925 HPA...WE WARM TO +17C TO THE WEST AND
+13C ACROSS THE SOUTHERN GENESEE VALLEY AND EASTERN NORTH COUNTRY.
MIXING THESE TEMPERATURE VALUES DOWN TO THE SURFACE...AND WITH A
MIX OF CLOUDS AND SUNSHINE WE SHOULD HAVE HIGHS IN THE 60S...WITH
A FEW DOWNSLOPING AREAS OF THE GENESEE VALLEY WESTWARD REACHING
INTO THE LOWER 70S.
WINDS WILL BECOME SOUTHERLY TOMORROW WITH HIGH PRESSURE TO OUR
EAST...AND LOW HANGING WELL TO OUR WEST OVER THE NORTHERN PLAINS.
THE PRESSURE GRADIENT DOES INCREASE LATE IN THE DAY TO THE
WEST...AND SOME AFTERNOON LIGHT BREEZES WILL BE LIKELY ACROSS WNY.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
DRY WEATHER SHOULD BE MAINTAINED WEDNESDAY NIGHT AHEAD OF THE
APPROACHING SLOW MOVING COLD FRONT. WARM AIR ADVECTION REGIME ON A
40 KNOT SOUTHERLY LOW LEVEL JET WILL ALLOW TEMPERATURES TO REMAIN
MILD...AND MAY EVEN RISE SLIGHTLY OVERNIGHT AS CLOUD COVER SPREADS
ACROSS THE AREA.
SOUTHERLY LOW LEVEL JET WILL CONTINUE TO STRENGTHEN AHEAD OF THE
FRONT THURSDAY...REACHING AT LEAST 50 KNOTS. WINDY CONDITIONS WILL
LIKELY DEVELOP...ESPECIALLY IF ANY SUNSHINE CAN DEVELOP AND AID
MIXING PROCESS. MODEL SOUNDINGS SUGGEST THE POTENTIAL FOR WIND GUSTS
TO 45 MPH AND POSSIBLY HIGHER FOR FAVORED DOWNSLOPE AREAS...THE
HIGHER TERRAIN OF THE SOUTHERN TIER AND FINGER LAKES. THE FRONT
LOOKS TO PUSH INTO WESTERN NEW YORK BY LATE IN THE DAY...ACCOMPANIED
BY A BAND OF SHOWERS AS A WELL DEFINED THETA E RIDGE LOOKS TO
DEVELOP ALONG AND JUST AHEAD OF THE FRONT. UPPER LEVEL SUPPORT LOOKS
DECENT UNDERNEATH LEFT EXIT REGION OF A 110 KNOT PLUS UPPER LEVEL
JET STREAK. TEMPERATURES LOOK MILD AHEAD OF THE FRONT WITH HIGHS IN
THE MID 60S TO LOWER 70S....ALTHOUGH COULD BE WARMER WITH ADDITIONAL
SUNSHINE AND SLOWER MOVEMENT OF THE COLD FRONT.
THE COLD FRONT AND BAND OF SHOWERS WILL SLOWLY WORK INTO EASTERN
SECTIONS THURSDAY NIGHT. A SHARP MID LEVEL DRY SLOT SURGING INTO THE
REGION IN WAKE OF THE FRONT SHOULD END THE PRECIPITATION FROM WEST
TO EAST. THERE LOOKS TO BE A BREAK IN THE PRECIPITATION FOR A GOOD
PART OF FRIDAY IN THE WAKE OF THE FRONT AND AHEAD OF THE SLOWLY
EVOLVING UPPER LEVEL LOW ACROSS THE NATIONS HEARTLAND. WESTERN
SECTIONS WILL HAVE THE BETTER CHANCES FOR SEEING PRECIPITATION
ASSOCIATED WITH THE UPPER LOW LATE IN THE DAY FRIDAY.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
MODEL DISCREPANCIES CONTINUE TO EXIST DURING THE PERIOD...ALTHOUGH
THE GENERAL MODEL IDEA TO SUGGEST A SLOW MOVING UPPER LOW WILL BE
PASSING ACROSS THE AREA OVER THE WEEKEND. THE SPEED/TIMING OF THE
UPPER LEVEL CIRCULATION IS CONTINUED TO BE HANDLE DIFFERENTLY BY THE
MEDIUM RANGE MODELS. THE 12Z GFS/CMC SUGGESTING A MORE PROGRESSIVE
SOLUTION WHICH LIFTS THE LOW OUT WITH A RETURN TO A MORE ZONAL FLOW
REGIME RATHER QUICKLY...WHILE THE ECMWF MAINTAINS A SLOWER AND MORE
SOUTHERN SOLUTION. AT THIS POINT...WOULD PREFER TO LEAN TOWARD THE
SLOWER ECMWF BASED A GENERAL BLOCKING PATTERN SEEN SOUTH OF
NEWFOUNDLAND DURING THIS TIME FRAME. THE SLOWER TIMING OF THE UPPER
LOW AND ASSOCIATED COLD POOL ALOFT WOULD FAVOR BETTER CHANCES FOR
SHOWERS...ESPECIALLY EARLY IN THE WEEKEND. WITH THE COLD POOL
OVERHEARD FOR THE WEEKEND...HIGH TEMPERATURES WILL LIKELY STRUGGLE
TO WARM OUT OF THE MIDDLE TO UPPER 50S BOTH WEEKEND DAYS...WITH
OVERNIGHT LOWS GENERALLY HOVERING IN THE LOWER TO MIDDLE 40S. BY
EARLY NEXT WEEK...ECMWF SUGGESTS THE UPPER LOW WILL FINALLY EXIT AS
THE NEXT UPPER TROUGH STARTS DIGGING ACROSS THE WESTERN CONUS AND
THE RIDGING SOUTH OF NEWFOUNDLAND BREAKS DOWN. THIS AGREES WELL WITH
THE GFS/CMC MODEL SOLUTIONS AND THEREFORE HAVE MAINTAINED DRY
WEATHER FOR THE REMAINDER OF THE PERIOD...WITH A GRADUAL WARMING
TREND.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
AT 00Z...LAKE EFFECT CLOUDS HAVE LARGELY DISSIPATED...AND THESE
WILL CONTINUE TO FALL APART OVERNIGHT. OUTSIDE OF THESE
CLOUDS...EXPECT SCT-BKN MID LEVEL CLOUDS TO MOVE IN. THESE ARE
ASSOCIATED WITH A WARM FRONT...BUT SHOULD BE WELL ABOVE 3000
FT...WITH VFR CONDITIONS LIKELY TO MAINTAIN. A LIGHT RAIN SHOWER
MAY BRUSH BY FAR NW NIAGARA FRONTIER JUST PAST DAWN AS A WARM
FRONT LIFTS ACROSS THE CENTRAL GREAT LAKES.
THROUGH THE DAY WEDNESDAY EXPECT VFR FLIGHT CONDITIONS...AND
SOUTHERLY WINDS BEHIND A WARM FRONT THAT WILL BE LIFTING INTO
CANADA.
OUTLOOK...
WEDNESDAY NIGHT...MAINLY VFR. LLWS POSSIBLE.
THURSDAY AND THURSDAY NIGHT...BREEZY AND DETERIORATING TO MVFR IN
RAIN SHOWERS BECOMING LIKELY THURSDAY NIGHT.
FRIDAY...MAINLY VFR IN CHC RAIN SHOWERS.
FRIDAY NIGHT THROUGH SUNDAY...VFR/MVFR WITH SCATTERED SHOWERS.
&&
.MARINE...
HIGH PRESSURE OVER THE OHIO VALLEY WILL CONTINUE TO RIDGE NORTHWARD
ACROSS THE EASTERN GREAT LAKES THIS EVENING.
A WARM FRONT WILL LIFT ACROSS THE LAKES WEDNESDAY BUT WINDS AND
WAVES SHOULD REMAIN BELOW SCA LEVELS. WEDNESDAY NIGHT UNDER A
CONTINUED SOUTHERLY FLOW WAVES WILL START TO BUILD TOWARDS 4 FEET ON
THE NORTHEASTERN PORTION OF LAKE ONTARIO.
ON THURSDAY WINDS WILL INCREASE WITH SCA LIKELY FOR BOTH LAKES AND
POSSIBLY SOME OF OUR TWO RIVERS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...THOMAS
NEAR TERM...APFFEL/THOMAS
SHORT TERM...TMA
LONG TERM...TMA
AVIATION...APFFEL
MARINE...APFFEL/THOMAS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
740 PM EDT TUE OCT 16 2012
.SYNOPSIS...
SURFACE HIGH PRESSURE BUILDS INTO THE NORTH COUNTRY TONIGHT BRINGING
DECREASING CLOUDINESS AND LIGHT WINDS. THE HIGH PRESSURE AREA MOVES
EAST INTO THE GULF OF MAINE DURING WEDNESDAY AFTERNOON...AND WILL
BRING DRY WEATHER WEDNESDAY AND THURSDAY...WITH A GRADUAL
MODERATION OF TEMPERATURES. A LARGE UPPER LOW PRESSURE SYSTEM AND
ASSOCIATED OCCLUDED FRONT SHOULD BRING A PERIOD OF RAINFALL TO THE
NORTH COUNTRY THURSDAY NIGHT INTO FRIDAY MORNING.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 705 PM EDT TUESDAY...CLOUDS TOUGH TO COMPLETELY ERODE THIS
EVENING AS LOW LEVEL MOISTURE REMAINS TRAPPED BENEATH BUILDING
SYNOPTIC INVERSION AND LINGERING NORTHWESTERLY FLOW. AS A
RESULT...HAVE OPTED TO KEEP CLOUDS ACROSS THE NRN MTNS FOR A FEW
HOURS LONGER THIS EVENING PER RAP MODEL SOUNDINGS...BEFORE
TRENDING THINGS MAINLY CLR OVERNIGHT...THOUGH SOME GRADUAL
INCREASE IN HIGH CLOUDS STILL POSSIBLE LATE ACROSS NRN NY. REST OF
FCST REMAINS IN GOOD SHAPE. HAVE A NICE EVENING.
PRIOR DISCUSSION...
SFC RIDGE AXIS SHIFTS EWD FROM THE ERN GREAT LAKES REGION AND
CRESTS OVER THE NORTH COUNTRY OVERNIGHT. INVERSION NEAR 3 KFT
KEEPING SHALLOW STRATUS LAYER IN PLACE LATE THIS AFTN...BUT
ANTICIPATE CLEARING AREAWIDE DURING THE EVENING HRS WITH
DRYING/SUBSIDENCE. LOOKING FOR MOSTLY CLEAR SKIES FOR THE
OVERNIGHT...ALTHOUGH A FEW MID-LEVEL CLOUDS (8-12 KFT) ASSOCIATED
WITH UPSTREAM SHORTWAVE TROUGH ACROSS THE UPR MS RIVER VALLEY/WRN
GREAT LAKES REGION WILL STREAM RAPIDLY EWD AND REACH NRN NY TOWARD
09Z. HAVE INDICATED SOME SCATTERED CLOUDS IN ASSOCIATION WITH THIS
FEATURE TOWARD DAYBREAK. SHOULD BE A PERIOD OF GOOD RADIATIONAL
COOLING WITH LOW TEMPERATURES GENERALLY IN THE UPPER 20S TO LOWER
30S. NWLY GRADIENT FLOW WITH WINDS 10-20 MPH AND A FEW GUSTS TO 30
MPH WILL QUICKLY ABATE THIS EVENING WITH BOUNDARY LAYER
STABILIZATION. ANY LINGERING SPRINKLES ACROSS THE NORTHEAST
KINGDOM WILL END LATE THIS AFTN/EARLY THIS EVENING WITH
DISSIPATION OF LOW CLOUD DECK WITH NIL POPS 00-12Z.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
AS OF 245 PM EDT TUESDAY...TRANQUIL WX UNTIL THURSDAY NIGHT. SFC RIDGE
AXIS DRIFTS EWD INTO THE GULF OF MAINE LATE WEDNESDAY WITH A
LIGHT 5-8 MPH SLY RETURN FLOW DEVELOPING. 850MB TEMPS MODERATE
NICELY TO +7C TO +8C BY 21Z WEDNESDAY. MID-LEVEL WAA AND
CONTINUATION OF RELATIVELY HIGH MID-LEVEL RH SUGGESTS PERIODS OF
MID-LEVEL CLOUDS DURING THE DAY WEDNESDAY. ALL IN ALL...WILL BE
PARTLY CLOUDY WITH PERIODS OF FILTERED SUN. CLOUDS SHOULDN/T
SIGNIFICANTLY IMPACT HIGH TEMPERATURES...SO STAYED CLOSE TO MOS
WITH MAX TEMPS IN THE MID-UPR 50S (OR ABOUT 10F HIGHER THAN
TUESDAY/S HIGHS).
VARIABLE MID-LEVEL CLOUDINESS CONTINUES WEDNESDAY NIGHT WITH LIGHT
SOUTH WINDS CONTINUING IN THE CHAMPLAIN VALLEY. SOME CLOUDS AND
MODIFYING AIR MASS WILL KEEP TEMPS A BIT WARMER COMPARED TO TUESDAY
NIGHT WITH LOWS WED NGT MID 30S TO LWR 40S.
THURSDAY LOOKS MILDER STILL AS MID-LEVEL HEIGHTS BUILD IN ADVANCE OF
LARGE-SCALE/SLOW-MOVING UPR LOW ACROSS THE MID-UPR MS RIVER VALLEY.
HIGHS WILL REACH THE MID-UPR 60S...WARMEST IN THE CHAMPLAIN AND ST.
LAWRENCE RIVER VALLEYS. SOUTH WINDS CONTINUE WITH SFC HIGH WELL
OFFSHORE AND VERTICALLY STACKED LOW OVER THE WRN GREAT LAKES. MAY
SEE AN INCREASE IN HIGH CLOUDS LATE IN THE DAY - ESPECIALLY ACROSS
NRN NY.
LEADING FRONTAL RAIN BAND WITH LARGE-SCALE OCCLUSION SWINGS INTO THE
FORECAST AREA DURING THURSDAY NIGHT BASED ON 12Z GFS/SREF/NAM. THE
ECMWF CONTINUES TO BE SLOWER WITH THE EVOLUTION OF THIS
SYSTEM...AND COULD SUGGEST A SLOWER PCPN ARRIVAL TIME. AT THIS
POINT...WILL INDICATE CLOUDY SKIES/LIKELY POPS WITH A STEADY
STRATIFORM RAIN DEVELOPING. QPF POTL 0.25-0.50"...THOUGH LIKELY
LESS ACROSS FAR ERN/NERN VT WITH LATER ARRIVAL TIME OF PRECIP.
WILL BE A MILD NIGHT WITH SE/SOUTH WINDS AND CLOUDS AREAWIDE. MAY
SEE SOME GUSTY DOWNSLOPE WINDS ALONG THE WESTERN SLOPES OF THE
GREEN MTNS (UP TO 35 MPH BASED ON PRESENT INDICATIONS) AND WILL BE
SOMETHING TO MONITOR AS DETAILS BECOME MORE APPARENT. SHOULD SEE
RATHER UNIFORM AND MILD LOW TEMPS EXPECTED IN THE UPR 40S TO LWR
50S.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 430 PM EDT TUESDAY...FCST FOCUS WL BE EVOLUTION/MOVEMENT OF
FULL LATITUDE CLOSED MID/UPPER LVL CIRCULATION ACRS THE EASTERN
CONUS AND IMPACTS TO OUR CWA. OVERALL MODELS IN GOOD AGREEMENT
WITH LARGE SCALE CLOSED SYSTEM SHIFTING FROM THE NORTHERN PLAINS
INTO THE OHIO VALLEY BY FRIDAY AND INTO EASTERN CANADA BY THE
WEEKEND. HOWEVER...PLENTY OF UNCERTAINTY WITH REGARDS TO TIMING OF
INDIVIDUAL S/W`S AND RIBBONS OF ENHANCED 850 TO 500MB RH...WHICH
RESULTS IN UNCERTAINTY IN PRECIP TIMING/PLACEMENT FOR FRIDAY INTO
THIS UPCOMING WEEKEND. GFS/SREF/GEM AND ECMWF ALL SHOW A SURGE OF
>1.0" PWS AHEAD OF OCCLUDED TYPE BOUNDARY ON FRIDAY INTO
SATURDAY...ASSOCIATED WITH POTENT LOW/MID LVL JET...AND STRONG
ULVL DIVERGENCE. GIVEN AVAILABLE MOISTURE/DYNAMICS WL CONT TO
MENTION HIGH LIKELY POPS ATTM FOR FRIDAY INTO SAT...BUT 6 TO 10 HR
WINDOW FOR HEAVIEST QPF IS DIFFICULT TO TIME. GIVEN THE DOWNSTREAM
BLOCKING FROM WESTERN ATLANTIC MID/UPPER LVL RIDGE AND DEEP CLOSED
CUTOFF CIRCULATION...FEEL A SLOWER/WETTER AND WARMER SOLUTION OF
THE GEM/ECMWF LOOKS REASONABLE AND WL TREND TWD. THIS SUPPORTS
ABOVE NORMAL TEMPS FOR FRI THRU SAT...WITH A COOLING TREND BY
SUNDAY...AS LLVL CAA DEVELOPS BEHIND DEPARTING CLOSED CIRCULATION.
IN ADDITION...WL CONT TO MENTION CHC POPS FOR SUNDAY ASSOCIATED
WITH UPSLOPE FLW AND LLVL CAA. THIS WL PROBABLY NEED TO BE
ADJUSTED UPWARD AS CONFIDENCE INCREASES WITH REGARDS TO AMOUNT OF
MOISTURE AND UPSLOPE LIFT. MID/UPPER LVL RIDGE REDEVELOPS FOR
EARLY NEXT WEEK...WITH ABOVE NORMAL TEMPS AND SOME DRYING.
&&
.AVIATION /23Z TUESDAY THROUGH SUNDAY/...
THROUGH 00Z THURSDAY...UPSLOPE CLOUDS ON NORTHWEST FLOW CONTINUE TO BRING
BKN/OVC MAINLY VFR CEILINGS /MVFR AT SLK/. GRADUAL LIFTING OF
CLOUDS IS EXPECTED AS RIDGE AXIS MOVES OVERHEAD AFTER 03Z AND
WINDS BECOME LIGHT/VARIABLE. AFTER 03Z EXPECTING VFR CONDITIONS
FOR THE TAFS AS CEILINGS LIFT...THOUGH THINK THERE WILL BE ENOUGH
CLEARING TO ALLOW FOR A BRIEF PERIOD OF 2SM BR AT MPV AFTER 09Z
LIFTING AROUND 13Z WEDNESDAY.
MAINLY VFR CONDITIONS EXPECTED FOR WEDNESDAY. SOME MID TO HIGH
CLOUDS MOVE IN LATE IN THE DAY AT MSS AND SLK. WINDS BECOME
SOUTHERLY AT OR BELOW 10KTS.
OUTLOOK 00Z THURSDAY THROUGH SATURDAY... SFC HIGH PRES WITH VFR
CONDITIONS PREVAIL THRU 00Z FRIDAY...BEFORE NEXT SYSTEM PRODUCE
WIDESPREAD RAIN WITH MVFR CONDITIONS BTWN 06Z FRIDAY AND 18Z
FRIDAY. IN ADDITION...SOME GUSTY SOUTH TO SOUTHEAST WINDS WL BE
POSSIBLE...ESPECIALLY AT RUT...ALONG WITH AREAS OF LLVL WIND SHEAR
AND TURBULENCE THURS NIGHT/FRIDAY MORNING. AREAS OF SCATTERED
SHOWERS WITH MVFR AND BRIEF PERIODS OF IFR AT SLK/MPV WL BE
POSSIBLE FRIDAY AFTN INTO SAT....AS SFC LOW PRES CONTS TO IMPACT
OUR TAF SITES.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...BANACOS/JMG
SHORT TERM...BANACOS
LONG TERM...TABER
AVIATION...TABER/LOCONTO
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
705 PM EDT TUE OCT 16 2012
.SYNOPSIS...
SURFACE HIGH PRESSURE BUILDS INTO THE NORTH COUNTRY TONIGHT BRINGING
DECREASING CLOUDINESS AND LIGHT WINDS. THE HIGH PRESSURE AREA MOVES
EAST INTO THE GULF OF MAINE DURING WEDNESDAY AFTERNOON...AND WILL
BRING DRY WEATHER WEDNESDAY AND THURSDAY...WITH A GRADUAL
MODERATION OF TEMPERATURES. A LARGE UPPER LOW PRESSURE SYSTEM AND
ASSOCIATED OCCLUDED FRONT SHOULD BRING A PERIOD OF RAINFALL TO THE
NORTH COUNTRY THURSDAY NIGHT INTO FRIDAY MORNING.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 705 PM EDT TUESDAY...CLOUDS TOUGH TO COMPLETELY ERODE THIS
EVENING AS LOW LEVEL MOISTURE REMAINS TRAPPED BENEATH BUILDING
SYNOPTIC INVERSION AND LINGERING NORTHWESTERLY FLOW. AS A
RESULT...HAVE OPTED TO KEEP CLOUDS ACROSS THE NRN MTNS FOR A FEW
HOURS LONGER THIS EVENING PER RAP MODEL SOUNDINGS...BEFORE
TRENDING THINGS MAINLY CLR OVERNIGHT...THOUGH SOME GRADUAL
INCREASE IN HIGH CLOUDS STILL POSSIBLE LATE ACROSS NRN NY. REST OF
FCST REMAINS IN GOOD SHAPE. HAVE A NICE EVENING.
PRIOR DISCUSSION...
SFC RIDGE AXIS SHIFTS EWD FROM THE ERN GREAT LAKES REGION AND
CRESTS OVER THE NORTH COUNTRY OVERNIGHT. INVERSION NEAR 3 KFT
KEEPING SHALLOW STRATUS LAYER IN PLACE LATE THIS AFTN...BUT
ANTICIPATE CLEARING AREAWIDE DURING THE EVENING HRS WITH
DRYING/SUBSIDENCE. LOOKING FOR MOSTLY CLEAR SKIES FOR THE
OVERNIGHT...ALTHOUGH A FEW MID-LEVEL CLOUDS (8-12 KFT) ASSOCIATED
WITH UPSTREAM SHORTWAVE TROUGH ACROSS THE UPR MS RIVER VALLEY/WRN
GREAT LAKES REGION WILL STREAM RAPIDLY EWD AND REACH NRN NY TOWARD
09Z. HAVE INDICATED SOME SCATTERED CLOUDS IN ASSOCIATION WITH THIS
FEATURE TOWARD DAYBREAK. SHOULD BE A PERIOD OF GOOD RADIATIONAL
COOLING WITH LOW TEMPERATURES GENERALLY IN THE UPPER 20S TO LOWER
30S. NWLY GRADIENT FLOW WITH WINDS 10-20 MPH AND A FEW GUSTS TO 30
MPH WILL QUICKLY ABATE THIS EVENING WITH BOUNDARY LAYER
STABILIZATION. ANY LINGERING SPRINKLES ACROSS THE NORTHEAST
KINGDOM WILL END LATE THIS AFTN/EARLY THIS EVENING WITH
DISSIPATION OF LOW CLOUD DECK WITH NIL POPS 00-12Z.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
AS OF 245 PM EDT TUESDAY...TRANQUIL WX UNTIL THURSDAY NIGHT. SFC RIDGE
AXIS DRIFTS EWD INTO THE GULF OF MAINE LATE WEDNESDAY WITH A
LIGHT 5-8 MPH SLY RETURN FLOW DEVELOPING. 850MB TEMPS MODERATE
NICELY TO +7C TO +8C BY 21Z WEDNESDAY. MID-LEVEL WAA AND
CONTINUATION OF RELATIVELY HIGH MID-LEVEL RH SUGGESTS PERIODS OF
MID-LEVEL CLOUDS DURING THE DAY WEDNESDAY. ALL IN ALL...WILL BE
PARTLY CLOUDY WITH PERIODS OF FILTERED SUN. CLOUDS SHOULDN/T
SIGNIFICANTLY IMPACT HIGH TEMPERATURES...SO STAYED CLOSE TO MOS
WITH MAX TEMPS IN THE MID-UPR 50S (OR ABOUT 10F HIGHER THAN
TUESDAY/S HIGHS).
VARIABLE MID-LEVEL CLOUDINESS CONTINUES WEDNESDAY NIGHT WITH LIGHT
SOUTH WINDS CONTINUING IN THE CHAMPLAIN VALLEY. SOME CLOUDS AND
MODIFYING AIR MASS WILL KEEP TEMPS A BIT WARMER COMPARED TO TUESDAY
NIGHT WITH LOWS WED NGT MID 30S TO LWR 40S.
THURSDAY LOOKS MILDER STILL AS MID-LEVEL HEIGHTS BUILD IN ADVANCE OF
LARGE-SCALE/SLOW-MOVING UPR LOW ACROSS THE MID-UPR MS RIVER VALLEY.
HIGHS WILL REACH THE MID-UPR 60S...WARMEST IN THE CHAMPLAIN AND ST.
LAWRENCE RIVER VALLEYS. SOUTH WINDS CONTINUE WITH SFC HIGH WELL
OFFSHORE AND VERTICALLY STACKED LOW OVER THE WRN GREAT LAKES. MAY
SEE AN INCREASE IN HIGH CLOUDS LATE IN THE DAY - ESPECIALLY ACROSS
NRN NY.
LEADING FRONTAL RAIN BAND WITH LARGE-SCALE OCCLUSION SWINGS INTO THE
FORECAST AREA DURING THURSDAY NIGHT BASED ON 12Z GFS/SREF/NAM. THE
ECMWF CONTINUES TO BE SLOWER WITH THE EVOLUTION OF THIS
SYSTEM...AND COULD SUGGEST A SLOWER PCPN ARRIVAL TIME. AT THIS
POINT...WILL INDICATE CLOUDY SKIES/LIKELY POPS WITH A STEADY
STRATIFORM RAIN DEVELOPING. QPF POTL 0.25-0.50"...THOUGH LIKELY
LESS ACROSS FAR ERN/NERN VT WITH LATER ARRIVAL TIME OF PRECIP.
WILL BE A MILD NIGHT WITH SE/SOUTH WINDS AND CLOUDS AREAWIDE. MAY
SEE SOME GUSTY DOWNSLOPE WINDS ALONG THE WESTERN SLOPES OF THE
GREEN MTNS (UP TO 35 MPH BASED ON PRESENT INDICATIONS) AND WILL BE
SOMETHING TO MONITOR AS DETAILS BECOME MORE APPARENT. SHOULD SEE
RATHER UNIFORM AND MILD LOW TEMPS EXPECTED IN THE UPR 40S TO LWR
50S.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 430 PM EDT TUESDAY...FCST FOCUS WL BE EVOLUTION/MOVEMENT OF
FULL LATITUDE CLOSED MID/UPPER LVL CIRCULATION ACRS THE EASTERN
CONUS AND IMPACTS TO OUR CWA. OVERALL MODELS IN GOOD AGREEMENT
WITH LARGE SCALE CLOSED SYSTEM SHIFTING FROM THE NORTHERN PLAINS
INTO THE OHIO VALLEY BY FRIDAY AND INTO EASTERN CANADA BY THE
WEEKEND. HOWEVER...PLENTY OF UNCERTAINTY WITH REGARDS TO TIMING OF
INDIVIDUAL S/W`S AND RIBBONS OF ENHANCED 850 TO 500MB RH...WHICH
RESULTS IN UNCERTAINTY IN PRECIP TIMING/PLACEMENT FOR FRIDAY INTO
THIS UPCOMING WEEKEND. GFS/SREF/GEM AND ECMWF ALL SHOW A SURGE OF
>1.0" PWS AHEAD OF OCCLUDED TYPE BOUNDARY ON FRIDAY INTO
SATURDAY...ASSOCIATED WITH POTENT LOW/MID LVL JET...AND STRONG
ULVL DIVERGENCE. GIVEN AVAILABLE MOISTURE/DYNAMICS WL CONT TO
MENTION HIGH LIKELY POPS ATTM FOR FRIDAY INTO SAT...BUT 6 TO 10 HR
WINDOW FOR HEAVIEST QPF IS DIFFICULT TO TIME. GIVEN THE DOWNSTREAM
BLOCKING FROM WESTERN ATLANTIC MID/UPPER LVL RIDGE AND DEEP CLOSED
CUTOFF CIRCULATION...FEEL A SLOWER/WETTER AND WARMER SOLUTION OF
THE GEM/ECMWF LOOKS REASONABLE AND WL TREND TWD. THIS SUPPORTS
ABOVE NORMAL TEMPS FOR FRI THRU SAT...WITH A COOLING TREND BY
SUNDAY...AS LLVL CAA DEVELOPS BEHIND DEPARTING CLOSED CIRCULATION.
IN ADDITION...WL CONT TO MENTION CHC POPS FOR SUNDAY ASSOCIATED
WITH UPSLOPE FLW AND LLVL CAA. THIS WL PROBABLY NEED TO BE
ADJUSTED UPWARD AS CONFIDENCE INCREASES WITH REGARDS TO AMOUNT OF
MOISTURE AND UPSLOPE LIFT. MID/UPPER LVL RIDGE REDEVELOPS FOR
EARLY NEXT WEEK...WITH ABOVE NORMAL TEMPS AND SOME DRYING.
&&
.AVIATION /23Z TUESDAY THROUGH SUNDAY/...
THROUGH 18Z WEDNESDAY...AVIATION CHALLENGE IS TIMING OF CLOUDS
DISSIPATING ACRS OUR TAF SITES THIS AFTN/EVENING. CRNT SFC
ANALYSIS SHOWS CYCLONIC UPSLOPE FLW ACRS OUR CWA WITH LOW PRES
LOCATED EAST OF CARIBOU MAINE THIS AFTN. THIS LLVL UPSLOPE
FLW...COMBINED WITH MOISTURE TRAPPED BLW TEMP INVERSION HAS RESULTED
PLENTY OF CLOUDS WITH MVFR CONDITIONS AT MOST SITES. NAM/GFS
VERTICAL SOUNDINGS ARE TOO QUICK AT ERODING THE CLOUDS...GIVEN
MOISTURE/WIND DIRECTION...WL TREND TOWARD THE LATEST RAP
SOUNDINGS. THESE SHOW MVFR BCMG VFR CONDITIONS BY 21Z AT
PBG/BTV/RUT/MSS AND AFT 00Z AT MPV/SLK WITH NW WINDS BECMG
LIGHT/VARIABLE TWD SUNSET. INTERESTING RAP SOUNDINGS CONT TO SHOW
VERY SHALLOW RH PROFILES OVERNIGHT AT SLK/MPV...BUT THINKING WITH
SFC HIGH PRES/SUBSIDENCE DEPTH OF MOISTURE WL NOT BE ENOUGH TO
PRODUCE CLOUDS...BUT SATL TRENDS WL NEED TO BE MONITORED.
OUTLOOK 18Z WEDNESDAY THROUGH SATURDAY...
SFC HIGH PRES WITH VFR CONDITIONS PREVAIL THRU 00Z FRIDAY...BEFORE
NEXT SYSTEM PRODUCE WIDESPREAD RAIN WITH MVFR CONDITIONS BTWN 06Z
FRIDAY AND 18Z FRIDAY. IN ADDITION...SOME GUSTY SOUTH TO SOUTHEAST
WINDS WL BE POSSIBLE...ESPECIALLY AT RUT...ALONG WITH AREAS OF LLVL
WIND SHEAR AND TURBULENCE THURS NIGHT/FRIDAY MORNING. AREAS OF
SCATTERED SHOWERS WITH MVFR AND BRIEF PERIODS OF IFR AT SLK/MPV WL
BE POSSIBLE FRIDAY AFTN INTO SAT....AS SFC LOW PRES CONTS TO
IMPACT OUR TAF SITES.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...JMG/BANACOS
SHORT TERM...BANACOS
LONG TERM...TABER
AVIATION...TABER
AREA FORECAST DISCUSSION
NWS RALEIGH NC
153 PM EDT MON OCT 15 2012
.SYNOPSIS...
A COLD FRONT WILL CROSS THE CAROLINAS AND SOUTHERN VIRGINIA THIS
AFTERNOON AND THIS EVENING. COOL HIGH PRESSURE WILL BUILD INTO THE
REGION IN THE WAKE OF THE FRONT TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM MONDAY...
FOR THE REST OF TODAY:
THE LATEST SURFACE MAP DEPICTS THE COLD FRONT STILL BACK OVER FAR
ERN TN... MOVING SLOWLY EASTWARD. JUST OFF THE SURFACE... 35-40 KT
SWRLY JET AT 925 MB AND 40-50 KT JETTING AT 850 MB STRETCHES FROM
WRN NC INTO NEW ENGLAND. FURTHER ALOFT... DEEP MID LEVEL TROUGHING
FROM ONTARIO THROUGH MI TO LA WILL SWING EASTWARD AND DEEPEN FURTHER
TODAY... SPREADING INTENSE HEIGHT FALLS (80-120 METERS IN 12 HRS)
OVER NC/VA LATER TODAY. THIS TROUGH`S APPROACH WILL STRENGTHEN THE
UPPER JET OVER MD/PA/NY THIS AFTERNOON... INSTIGATING STRONG UPPER
DIVERGENCE OVER CENTRAL/ERN NC... JUST AHEAD OF STRONG MID LEVEL
DPVA.
THE RISK OF SHOWERS AND STORMS GENERATING STRONG WIND GUSTS WILL
PERSIST THROUGH THE AFTERNOON. AN INITIAL BROAD BAND OF HEAVY
SHOWERS AND STORMS MOVING THROUGH THE TRIAD AND WRN PIEDMONT APPEARS
TO BE LINKED TO A MID LEVEL WAVE NOTED ON WATER VAPOR IMAGERY
PUSHING THROUGH THE SRN/CENTRAL MOUNTAINS/FOOTHILLS. AS THIS FEATURE
CONTINUES TO LIFT RAPIDLY NE... THIS HEAVY PRECIP AREA SHOULD
LIKEWISE TRANSLATE NNE INTO VA... LEAVING BEHIND A THIN BROKEN LINE
OF WEAKER SHOWERS FOR A FEW HOURS. AS THE UPPER DIVERGENCE
STRENGTHENS WITH THE APPROACH OF THE SURFACE FRONT BY EARLY TO MID
AFTERNOON... THE IMPROVING DYNAMICS WILL COINCIDE WITH MARGINAL
DESTABILIZATION (800-1200 J/KG MLCAPE)... AND REDEVELOPMENT OF A
BAND OF STORMS OVER THE CENTRAL/ERN PIEDMONT APPEARS LIKELY JUST
AHEAD OF THE FRONT... A SCENARIO DEPICTED BY THE LATEST HRRR MODEL
RUNS. FORECAST RAIN CHANCES FOR TODAY REFLECT SUCH A TIMING SCENARIO
FAIRLY WELL AND ONLY SMALL CHANGES ARE NEEDED.
THE LOW LEVEL JET IS EXPECTED TO WEAKEN A BIT OVER NC AS THE HEART
OF THE JET LIFTS TO OUR NORTH... HOWEVER THE OTHERWISE FAVORABLE
KINEMATICS COMBINED WITH LARGER SCALE FORCING ROOTED IN THE UPPER
LEVELS... STILL-FORMIDABLE LOWER LEVEL MASS CONVERGENCE... 30-40 KTS
OF DEEP LAYER SHEAR... AND MARGINAL INSTABILITY MAY LEAD TO A FEW
DISCRETE BOWING SEGMENTS EMBEDDED WITHIN THE LARGER LINE OF
CONVECTION. BACKGROUND WINDS ALONE WILL SUPPORT PERIODIC GUSTS OF
25-30 KTS WITH ANY CONVECTION... AND STRONGER GUSTS OVER 45 KTS
REMAIN POSSIBLE IN CONJUNCTION WITH ANY BOWING SEGMENTS OR DISCRETE
CELLS. FAIRLY MEAGER MID LEVEL LAPSE RATES WILL PRECLUDE A MAJOR
HAIL THREAT... PARTICULARLY CONSIDERING THE LACK OF A BROAD "FAT"
CAPE TO SUPPORT ESPECIALLY VIGOROUS UPDRAFTS... ALTHOUGH IF WE CAN
GET A FEW HOURS OF SUNSHINE IN THE COASTAL PLAIN... POCKETS OF
HIGHER CAPE AND STRONGER DIFFERENTIAL HEATING COULD INTENSIFY
CONVECTION THERE. FINALLY... TRAINING OF SHOWERS AND STORMS
PARTICULARLY OVER URBAN AREAS COULD LEAD TO LOCALIZED FLOODING
PROBLEMS IN SUSCEPTIBLE LOCATIONS THROUGH THIS AFTERNOON. WILL MAKE
APPROPRIATE ADJUSTMENTS TO THE HAZARDOUS WEATHER OUTLOOK TO REFLECT
THIS.
TEMPS ARE A CHALLENGE GIVEN THE STEADY PRECIP OVER THE WRN CWA
BALANCED WITH THE STRONG WARM AIR ADVECTION. WILL MAKE A MINOR
DOWNWARD ADJUSTMENT MAINLY IN THE WEST WHERE READINGS HOLD IN THE
LOW-MID 60S. OVERALL... EXPECT HIGHS NEAR 70 TO THE MID 70S. -GIH
TONIGHT...WITH FROPA OCCURRING LATER THIS AFTERNOON THROUGH EARLY
EVENING AND STRONG SUBSIDENCE NOTED BEHIND THE FRONT...EXPECT
SHOWERS TO END QUICKLY WITH THE FRONTAL PASSAGE...WITH SKIES
CLEARING SHORTLY AFTER. STEADY NW FLOW OVERNIGHT WILL USHER A COOLER
AND DRIER AIR MASS INTO THE REGION. MOS GUIDANCE ACCEPTED WITH MINOR
TWEAKS. -WSS
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 255 AM MONDAY...
TUESDAY AND TUESDAY NIGHT...SURFACE HIGH PRESSURE WILL BUILD INTO
AND CROSS THE REGION. 850MB THERMAL TROUGH OVER THE AREA THROUGH
TUESDAY NIGHT. THIS RESULTS IN THICKNESSES IN THE MID 1360S TUESDAY
AFTERNOON...ABOUT 10-12M BELOW NORMAL. THIS SUPPORTS MAX TEMPS ABOUT
3-5 DEGREES COOLER THAN NORMAL. MAX TEMPS TUESDAY MID 60S N-NW TO
AROUND 70 SOUTH.
SURFACE RIDGE EXTENDS ACROSS REGION TUESDAY NIGHT. THIS WOULD
SUGGEST SURFACE WINDS DECOUPLING NEAR SUNSET. WOULD NORMALLY EXPECT
CLEAR SKIES IN THIS REGIME BUT SEVERAL OF THE MODELS DEPICT AN
INCREASE IN HIGH LEVEL MOISTURE ASSOCIATED WITH A MID-UPPER S/W IN
THE WLY FLOW ALOFT. THE GFS QUITE MOIST ABOVE 500MB...DEPICTING A
SOLID VEIL OF CIRRUS. THE ECMWF AND NAM NOT AS ROBUST BUT DO HINT AT
POTENTIAL FOR HIGH LEVEL CLOUDINESS. THUS...EXISTENCE OF CIRRUS
SHIELD MAY BE ENOUGH TO PREVENT SURFACE AIR MASS FROM REALIZING FULL
COOLING POTENTIAL. WILL FORECAST MIN TEMPS IN THE 40-45 DEGREE
RANGE. IF CIRRUS SHIELD THINNER THAN ANTICIPATED...THIS WOULD LEAD
TO COOLER MIN TEMPS AND SOME UPPER 30S PROBABLE AT THE NORMALLY
COLDER SITES. -WSS
WEDNESDAY AND WEDNESDAY NIGHT:
SURFACE HIGH PRESSURE IS EXPECTED TO MOVE OFFSHORE ON WEDNESDAY
ALLOWING FOR A WARMING SOUTHERLY RETURN FLOW TO DEVELOP. HOWEVER...
THIS MAY BE TEMPERED A BIT BY A WEAK S/W ALOFT TRACKING ACROSS THE
AREA WEDNESDAY MORNING INTO AFTERNOON (WITH THE STRONGEST PORTIONS
OF THE IMPULSE STAYING TO THE SOUTH OF THE AREA). THIS SHOULD ALOFT
FOR A PERIOD OF SCATTERED TO BROKEN MID/HIGH LEVEL CLOUDS ON
WEDNESDAY MORNING INTO THE AFTERNOON... WITH CLEARING SKIES FROM NW
TO SE IN THE AFTERNOON TO LATE AFTERNOON. NOT EXPECTING ANY PRECIP
WITH THIS FEATURE AS PW`S WILL REMAIN GENERALLY NEAR OR BELOW 0.60".
AFTERNOON LOW LEVEL THICKNESS VALUES ARE EXPECTED TO TOP OUT IN THE
1365 TO 1370 METER RANGE. THIS SHOULD GENERALLY YIELD TEMPS FROM THE
LOWER TO MID 70S ACROSS THE AREA.
WEDNESDAY NIGHT EXPECT SKIES WILL GENERALLY BE MOSTLY CLEAR OUTSIDE
OF SOME INCREASING HIGH LEVEL CLOUD COVER AHEAD OF THE NEXT SYSTEM
EXPECTED TO AFFECT THE AREA IN THE EXTENDED PORTION OF THE FORECAST.
HOWEVER... WITH THE SURFACE HIGH TO THE EAST OF THE AREA EXPECT
OVERNIGHT LOWS WILL NOT BE AS COOL/COLD AS THE PREVIOUS NIGHT.
THUS... WILL GO WITH LOWS THURSDAY MORNING IN THE UPPER 40S TO LOWER
50S. -BSD
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 305 AM MONDAY...
MEDIUM RANGE MODELS ARE IN GOOD AGREEMENT SHOWING A CLOSED LOW
DEVELOPING/MOVING INTO THE UPPER MIDWEST AND GREAT LAKES REGION LATE
WEEK... CREATING A FULL LATITUDE TROUGH OVER THE EASTERN HALF OF THE
COUNTRY. HOWEVER... MODELS CONTINUE TO STRUGGLE WITH THE PROGRESSION
OF THIS SYSTEM.
AS THE ABOVE MENTIONED UPPER LOW SLOWLY SHIFTS EASTWARD AND
EVENTUALLY BEGINS TO LIFT NORTH-NORTHEASTWARD EXPECT AN ASSOCIATED
COLD FRONT WILL APPROACH CENTRAL NC ON THURSDAY... MOVING INTO THE
AREA SOMETIME IN THE LATE THURSDAY TO FRIDAY TIMEFRAME. MODELS
CONTINUE TO STRUGGLE WITH THE TIMING OF THE FRONT AND ITS
PROGRESSION THROUGH THE AREA... WITH THE OPERATIONAL 00Z GFS AND
CANADIAN SHOWING THE LEADING FRONT TO THE EAST OF THE AREA BY MID TO
LATE FRIDAY. WITH THE 12Z HIRES ECMWF SHOWING THE FRONT STILL TO THE
WEST OF THE AREA AT THIS TIME (ECMWF MOVES THE FRONT SLOWLY THROUGH
THE AREA FROM FRIDAY NIGHT TROUGH SATURDAY AFTERNOON). THUS... MUCH
UNCERTAINTY STILL EXISTS FOR THE THURSDAY NIGHT THROUGH SATURDAY
TIMEFRAME. HOWEVER... WITH THE 00Z LOWRES ECMWF SHOWING THE FRONT
MOVING THROUGH THE AREA A BIT QUICKER THAN PREVIOUSLY INDICATED WILL
NARROW THE TIME RANGE FOR CHANCE POPS DOWN A BIT AND ACCORDINGLY
ADJUST TEMPS TO FIT A BIT FASTER FRONTAL PASSAGE THAN PREVIOUSLY
INDICATED... WITH DRY WEATHER RETURNING BY MID/LATE SATURDAY THROUGH
SUNDAY AS SURFACE HIGH PRESSURE BUILDS BACK INTO THE REGION. FOR NOW
WILL GO WITH CHANCE POPS THURSDAY NIGHT INTO FRIDAY NIGHT... WITH
ONLY A SLIGHT CHANCE FOR SATURDAY WITH THE POTENTIAL OF THE SLOWER
ECMWF AND POSSIBLE POST FRONTAL PRECIP.
EXPECT HIGH TEMPS ON THURSDAY WILL RANGE FROM THE LOWER 70S IN THE
NW TO NEAR 80 IN THE SE... WITH THE POTENTIAL FOR HIGHS TO BE A BIT
COOLER IN THE NW IF THE MORE PROGRESSIVE SET OF GUIDANCE IS CORRECT
AND MOVES THE FRONT INTO OUR NW THURSDAY AFTERNOON. LOWS AND HIGHS
FRIDAY AND SATURDAY WILL ULTIMATELY DEPEND ON THE TIMING OF THE
FRONT... THUS... TRICKY LOW AND HIGH TEMP FORECAST. FOR NOW WILL GO
WITH HIGHS IN THE MID TO UPPER 60S NW TO LOWER TO MID 70S E. EXPECT
LOWS FRIDAY MORNING TO RANGE FROM THE LOWER 50S NW TO AROUND 60
SE... WITH LOWS SATURDAY MORNING EXPECTED TO RANGE FROM THE AROUND
50 NW TO THE UPPER 50S NEAR 60 IN THE EAST. EXPECT LOWS SUNDAY
MORNING TO RANGE FROM THE MID 40 TO AROUND 50. HIGH SUNDAY ARE
EXPECTED TO BE IN THE MID/UPPER 60S TO NEAR 70 IN THE SE.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 150 PM MONDAY...
AVIATION CONDITIONS WILL SHOW AN IMPROVING TREND OVER THE NEXT 6-9
HOURS. IFR CIGS AT INT/GSO WILL MIX OUT WITH CIGS RISING TO VFR
AFTER 20Z THIS AFTERNOON... BEHIND A COLD FRONT THAT WILL MOVE
EASTWARD THROUGH CENTRAL NC LATE AFTERNOON THROUGH VERY EARLY
EVENING. THE FRONT WILL MOVE INT/GSO AT 19-21Z AND THROUGH
RDU/FAY/RWI 21Z-23Z. SW WINDS UNDER 12 KTS WILL SWING AROUND TO
WESTERLY OR FROM THE WNW WITH FRONTAL PASSAGE AT SPEEDS OF 8-12 KTS
GUSTING TO 15-20 KTS FOR A FEW HOURS... BEFORE WINDS COME OUT OF THE
NORTH AND DECREASE TO UNDER 8 KTS LATE EVENING ONWARD. SCATTERED
STORMS ARE EXPECTED NEAR RDU/FAY BETWEEN 18Z AND 22Z... AND NEAR RWI
19Z-23Z... AND BRIEF MVFR OR IFR CIGS ARE POSSIBLE BUT UNLIKELY TO
LAST MORE THAN AN HOUR. LINGERING VFR CIGS ESPECIALLY NEAR FAY THIS
EVENING WILL DISSIPATE AFTER 03Z WITH GENERALLY CLEAR SKIES AND CALM
CONDITIONS AREAWIDE OVERNIGHT THROUGH 18Z TUESDAY.
LOOKING BEYOND EARLY TUESDAY AFTERNOON... VFR CONDITIONS ARE LIKELY
TUESDAY THROUGH WEDNESDAY WITH ONLY HIGH CLOUDS AFFECTING THE AREA
UNDER HIGH PRESSURE. A PERIOD OF MVFR/IFR CIGS/VSBYS IN FOG IS
POSSIBLE EARLY THURSDAY MORNING WITH BORDERLINE LLWS CONDITIONS AS
SW WINDS STRENGTHEN ABOVE 2 KFT. ISOLATED SHOWERS WITH MVFR
CONDITIONS ARE POSSIBLE FRIDAY AFTERNOON WITH AN APPROACHING WEAK
COLD FRONT. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...HARTFIELD/WSS
SHORT TERM...WSS/BSD
LONG TERM...BSD
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1015 AM EDT MON OCT 15 2012
.SYNOPSIS...
A COLD FRONT WILL CROSS THE CAROLINAS AND SOUTHERN VIRGINIA THIS
AFTERNOON AND THIS EVENING. COOL HIGH PRESSURE WILL BUILD INTO THE
REGION IN THE WAKE OF THE FRONT TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM MONDAY...
FOR THE REST OF TODAY:
THE LATEST SURFACE MAP DEPICTS THE COLD FRONT STILL BACK OVER FAR
ERN TN... MOVING SLOWLY EASTWARD. JUST OFF THE SURFACE... 35-40 KT
SWRLY JET AT 925 MB AND 40-50 KT JETTING AT 850 MB STRETCHES FROM
WRN NC INTO NEW ENGLAND. FURTHER ALOFT... DEEP MID LEVEL TROUGHING
FROM ONTARIO THROUGH MI TO LA WILL SWING EASTWARD AND DEEPEN FURTHER
TODAY... SPREADING INTENSE HEIGHT FALLS (80-120 METERS IN 12 HRS)
OVER NC/VA LATER TODAY. THIS TROUGH`S APPROACH WILL STRENGTHEN THE
UPPER JET OVER MD/PA/NY THIS AFTERNOON... INSTIGATING STRONG UPPER
DIVERGENCE OVER CENTRAL/ERN NC... JUST AHEAD OF STRONG MID LEVEL
DPVA.
THE RISK OF SHOWERS AND STORMS GENERATING STRONG WIND GUSTS WILL
PERSIST THROUGH THE AFTERNOON. AN INITIAL BROAD BAND OF HEAVY
SHOWERS AND STORMS MOVING THROUGH THE TRIAD AND WRN PIEDMONT APPEARS
TO BE LINKED TO A MID LEVEL WAVE NOTED ON WATER VAPOR IMAGERY
PUSHING THROUGH THE SRN/CENTRAL MOUNTAINS/FOOTHILLS. AS THIS FEATURE
CONTINUES TO LIFT RAPIDLY NE... THIS HEAVY PRECIP AREA SHOULD
LIKEWISE TRANSLATE NNE INTO VA... LEAVING BEHIND A THIN BROKEN LINE
OF WEAKER SHOWERS FOR A FEW HOURS. AS THE UPPER DIVERGENCE
STRENGTHENS WITH THE APPROACH OF THE SURFACE FRONT BY EARLY TO MID
AFTERNOON... THE IMPROVING DYNAMICS WILL COINCIDE WITH MARGINAL
DESTABILIZATION (800-1200 J/KG MLCAPE)... AND REDEVELOPMENT OF A
BAND OF STORMS OVER THE CENTRAL/ERN PIEDMONT APPEARS LIKELY JUST
AHEAD OF THE FRONT... A SCENARIO DEPICTED BY THE LATEST HRRR MODEL
RUNS. FORECAST RAIN CHANCES FOR TODAY REFLECT SUCH A TIMING SCENARIO
FAIRLY WELL AND ONLY SMALL CHANGES ARE NEEDED.
THE LOW LEVEL JET IS EXPECTED TO WEAKEN A BIT OVER NC AS THE HEART
OF THE JET LIFTS TO OUR NORTH... HOWEVER THE OTHERWISE FAVORABLE
KINEMATICS COMBINED WITH LARGER SCALE FORCING ROOTED IN THE UPPER
LEVELS... STILL-FORMIDABLE LOWER LEVEL MASS CONVERGENCE... 30-40 KTS
OF DEEP LAYER SHEAR... AND MARGINAL INSTABILITY MAY LEAD TO A FEW
DISCRETE BOWING SEGMENTS EMBEDDED WITHIN THE LARGER LINE OF
CONVECTION. BACKGROUND WINDS ALONE WILL SUPPORT PERIODIC GUSTS OF
25-30 KTS WITH ANY CONVECTION... AND STRONGER GUSTS OVER 45 KTS
REMAIN POSSIBLE IN CONJUNCTION WITH ANY BOWING SEGMENTS OR DISCRETE
CELLS. FAIRLY MEAGER MID LEVEL LAPSE RATES WILL PRECLUDE A MAJOR
HAIL THREAT... PARTICULARLY CONSIDERING THE LACK OF A BROAD "FAT"
CAPE TO SUPPORT ESPECIALLY VIGOROUS UPDRAFTS... ALTHOUGH IF WE CAN
GET A FEW HOURS OF SUNSHINE IN THE COASTAL PLAIN... POCKETS OF
HIGHER CAPE AND STRONGER DIFFERENTIAL HEATING COULD INTENSIFY
CONVECTION THERE. FINALLY... TRAINING OF SHOWERS AND STORMS
PARTICULARLY OVER URBAN AREAS COULD LEAD TO LOCALIZED FLOODING
PROBLEMS IN SUSCEPTIBLE LOCATIONS THROUGH THIS AFTERNOON. WILL MAKE
APPROPRIATE ADJUSTMENTS TO THE HAZARDOUS WEATHER OUTLOOK TO REFLECT
THIS.
TEMPS ARE A CHALLENGE GIVEN THE STEADY PRECIP OVER THE WRN CWA
BALANCED WITH THE STRONG WARM AIR ADVECTION. WILL MAKE A MINOR
DOWNWARD ADJUSTMENT MAINLY IN THE WEST WHERE READINGS HOLD IN THE
LOW-MID 60S. OVERALL... EXPECT HIGHS NEAR 70 TO THE MID 70S. -GIH
TONIGHT...WITH FROPA OCCURRING LATER THIS AFTERNOON THROUGH EARLY
EVENING AND STRONG SUBSIDENCE NOTED BEHIND THE FRONT...EXPECT
SHOWERS TO END QUICKLY WITH THE FRONTAL PASSAGE...WITH SKIES
CLEARING SHORTLY AFTER. STEADY NW FLOW OVERNIGHT WILL USHER A COOLER
AND DRIER AIR MASS INTO THE REGION. MOS GUIDANCE ACCEPTED WITH MINOR
TWEAKS. -WSS
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 255 AM MONDAY...
TUESDAY AND TUESDAY NIGHT...SURFACE HIGH PRESSURE WILL BUILD INTO
AND CROSS THE REGION. 850MB THERMAL TROUGH OVER THE AREA THROUGH
TUESDAY NIGHT. THIS RESULTS IN THICKNESSES IN THE MID 1360S TUESDAY
AFTERNOON...ABOUT 10-12M BELOW NORMAL. THIS SUPPORTS MAX TEMPS ABOUT
3-5 DEGREES COOLER THAN NORMAL. MAX TEMPS TUESDAY MID 60S N-NW TO
AROUND 70 SOUTH.
SURFACE RIDGE EXTENDS ACROSS REGION TUESDAY NIGHT. THIS WOULD
SUGGEST SURFACE WINDS DECOUPLING NEAR SUNSET. WOULD NORMALLY EXPECT
CLEAR SKIES IN THIS REGIME BUT SEVERAL OF THE MODELS DEPICT AN
INCREASE IN HIGH LEVEL MOISTURE ASSOCIATED WITH A MID-UPPER S/W IN
THE WLY FLOW ALOFT. THE GFS QUITE MOIST ABOVE 500MB...DEPICTING A
SOLID VEIL OF CIRRUS. THE ECMWF AND NAM NOT AS ROBUST BUT DO HINT AT
POTENTIAL FOR HIGH LEVEL CLOUDINESS. THUS...EXISTENCE OF CIRRUS
SHIELD MAY BE ENOUGH TO PREVENT SURFACE AIR MASS FROM REALIZING FULL
COOLING POTENTIAL. WILL FORECAST MIN TEMPS IN THE 40-45 DEGREE
RANGE. IF CIRRUS SHIELD THINNER THAN ANTICIPATED...THIS WOULD LEAD
TO COOLER MIN TEMPS AND SOME UPPER 30S PROBABLE AT THE NORMALLY
COLDER SITES. -WSS
WEDNESDAY AND WEDNESDAY NIGHT:
SURFACE HIGH PRESSURE IS EXPECTED TO MOVE OFFSHORE ON WEDNESDAY
ALLOWING FOR A WARMING SOUTHERLY RETURN FLOW TO DEVELOP. HOWEVER...
THIS MAY BE TEMPERED A BIT BY A WEAK S/W ALOFT TRACKING ACROSS THE
AREA WEDNESDAY MORNING INTO AFTERNOON (WITH THE STRONGEST PORTIONS
OF THE IMPULSE STAYING TO THE SOUTH OF THE AREA). THIS SHOULD ALOFT
FOR A PERIOD OF SCATTERED TO BROKEN MID/HIGH LEVEL CLOUDS ON
WEDNESDAY MORNING INTO THE AFTERNOON... WITH CLEARING SKIES FROM NW
TO SE IN THE AFTERNOON TO LATE AFTERNOON. NOT EXPECTING ANY PRECIP
WITH THIS FEATURE AS PW`S WILL REMAIN GENERALLY NEAR OR BELOW 0.60".
AFTERNOON LOW LEVEL THICKNESS VALUES ARE EXPECTED TO TOP OUT IN THE
1365 TO 1370 METER RANGE. THIS SHOULD GENERALLY YIELD TEMPS FROM THE
LOWER TO MID 70S ACROSS THE AREA.
WEDNESDAY NIGHT EXPECT SKIES WILL GENERALLY BE MOSTLY CLEAR OUTSIDE
OF SOME INCREASING HIGH LEVEL CLOUD COVER AHEAD OF THE NEXT SYSTEM
EXPECTED TO AFFECT THE AREA IN THE EXTENDED PORTION OF THE FORECAST.
HOWEVER... WITH THE SURFACE HIGH TO THE EAST OF THE AREA EXPECT
OVERNIGHT LOWS WILL NOT BE AS COOL/COLD AS THE PREVIOUS NIGHT.
THUS... WILL GO WITH LOWS THURSDAY MORNING IN THE UPPER 40S TO LOWER
50S. -BSD
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 305 AM MONDAY...
MEDIUM RANGE MODELS ARE IN GOOD AGREEMENT SHOWING A CLOSED LOW
DEVELOPING/MOVING INTO THE UPPER MIDWEST AND GREAT LAKES REGION LATE
WEEK... CREATING A FULL LATITUDE TROUGH OVER THE EASTERN HALF OF THE
COUNTRY. HOWEVER... MODELS CONTINUE TO STRUGGLE WITH THE PROGRESSION
OF THIS SYSTEM.
AS THE ABOVE MENTIONED UPPER LOW SLOWLY SHIFTS EASTWARD AND
EVENTUALLY BEGINS TO LIFT NORTH-NORTHEASTWARD EXPECT AN ASSOCIATED
COLD FRONT WILL APPROACH CENTRAL NC ON THURSDAY... MOVING INTO THE
AREA SOMETIME IN THE LATE THURSDAY TO FRIDAY TIMEFRAME. MODELS
CONTINUE TO STRUGGLE WITH THE TIMING OF THE FRONT AND ITS
PROGRESSION THROUGH THE AREA... WITH THE OPERATIONAL 00Z GFS AND
CANADIAN SHOWING THE LEADING FRONT TO THE EAST OF THE AREA BY MID TO
LATE FRIDAY. WITH THE 12Z HIRES ECMWF SHOWING THE FRONT STILL TO THE
WEST OF THE AREA AT THIS TIME (ECMWF MOVES THE FRONT SLOWLY THROUGH
THE AREA FROM FRIDAY NIGHT TROUGH SATURDAY AFTERNOON). THUS... MUCH
UNCERTAINTY STILL EXISTS FOR THE THURSDAY NIGHT THROUGH SATURDAY
TIMEFRAME. HOWEVER... WITH THE 00Z LOWRES ECMWF SHOWING THE FRONT
MOVING THROUGH THE AREA A BIT QUICKER THAN PREVIOUSLY INDICATED WILL
NARROW THE TIME RANGE FOR CHANCE POPS DOWN A BIT AND ACCORDINGLY
ADJUST TEMPS TO FIT A BIT FASTER FRONTAL PASSAGE THAN PREVIOUSLY
INDICATED... WITH DRY WEATHER RETURNING BY MID/LATE SATURDAY THROUGH
SUNDAY AS SURFACE HIGH PRESSURE BUILDS BACK INTO THE REGION. FOR NOW
WILL GO WITH CHANCE POPS THURSDAY NIGHT INTO FRIDAY NIGHT... WITH
ONLY A SLIGHT CHANCE FOR SATURDAY WITH THE POTENTIAL OF THE SLOWER
ECMWF AND POSSIBLE POST FRONTAL PRECIP.
EXPECT HIGH TEMPS ON THURSDAY WILL RANGE FROM THE LOWER 70S IN THE
NW TO NEAR 80 IN THE SE... WITH THE POTENTIAL FOR HIGHS TO BE A BIT
COOLER IN THE NW IF THE MORE PROGRESSIVE SET OF GUIDANCE IS CORRECT
AND MOVES THE FRONT INTO OUR NW THURSDAY AFTERNOON. LOWS AND HIGHS
FRIDAY AND SATURDAY WILL ULTIMATELY DEPEND ON THE TIMING OF THE
FRONT... THUS... TRICKY LOW AND HIGH TEMP FORECAST. FOR NOW WILL GO
WITH HIGHS IN THE MID TO UPPER 60S NW TO LOWER TO MID 70S E. EXPECT
LOWS FRIDAY MORNING TO RANGE FROM THE LOWER 50S NW TO AROUND 60
SE... WITH LOWS SATURDAY MORNING EXPECTED TO RANGE FROM THE AROUND
50 NW TO THE UPPER 50S NEAR 60 IN THE EAST. EXPECT LOWS SUNDAY
MORNING TO RANGE FROM THE MID 40 TO AROUND 50. HIGH SUNDAY ARE
EXPECTED TO BE IN THE MID/UPPER 60S TO NEAR 70 IN THE SE.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 705 AM MONDAY...
AVIATION CONDITIONS BEGINNING TO DETERIORATE WEST-TO-EAST EARLY THIS
MORNING AS A COLD FRONT APPROACH THE REGION FROM THE WEST. CEILINGS
MAINLY IN THE MVFR CATEGORY OVER THE WESTERN PIEDMONT WITH SHOWER
COVERAGE INCREASING WITH THE PROBABILITY OF IFR CEILINGS IN VICINITY
OF THE HEAVIER SHOWERS. EXPECT CEILINGS TO LOWER INTO THE MVFR
CATEGORY OVER THE REMAINDER OF CENTRAL NC PRIOR TO 10 AM WITH
SHOWERS BECOMING NUMEROUS IN THE AFTERNOON. A FEW STRONG TO SEVERE
STORMS CAN BE EXPECTED THIS AFTERNOON...MAINLY IN THE EASTERN
PIEDMONT...COASTAL PLAIN AND SANDHILLS...WITH WIND GUSTS IN EXCESS
OF 40 KTS PROBABLE.
THE COLD FRONT WILL CROSS CENTRAL NC THIS AFTERNOON THROUGH EARLY
EVENING. THE FRONT SHOULD CROSS THE TRIAD TERMINAL BETWEEN 2 AND 4
PM...KRDU AND KFAY BETWEEN 5 AND 7 PM...AND KRWI BETWEEN 7 AND 9 PM.
THE FRONTAL PASSAGE WILL BE NOTED BY THE SURFACE WINDS VEERING FROM
THE SW TO THE NW. THE SHOWERS SHOULD END AND CEILINGS LIFT INTO THE
VFR CATEGORY WITHIN AN HOUR OF FROPA...AND CLOUDS DISSIPATING WITHIN
A COUPLE HOURS AFTER FROPA.
LATE TONIGHT THROUGH WEDNESDAY...EXPECT VFR CONDITIONS AS HIGH
PRESSURE BUILDS INTO THEN LINGERS OVER THE CAROLINAS. THERE IS THE
POSSIBILITY OF SUB-VFR FOG EARLY THURSDAY MORNING. LATER THURSDAY
INTO FRIDAY...AVIATION CONDITIONS ARE EXPECTED TO DETERIORATE AS
ANOTHER COLD FRONT APPROACHES FROM THE WEST.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...HARTFIELD/WSS
SHORT TERM...WSS/BSD
LONG TERM...BSD
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
729 PM EDT TUE OCT 16 2012
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTHEAST ACROSS THE GREAT LAKES TONIGHT AND
WEDNESDAY. A COLD FRONT WILL SWEEP ACROSS THE AREA ON THURSDAY. AN
UPPER LOW WILL DROP SOUTHEAST ACROSS THE MIDWEST ON THURSDAY AND
CROSS THE LOCAL AREA ON FRIDAY INTO SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
INCREASING CLOUDS FOR TONIGHT AND CONTINUED THE 20 POPS. INCREASED
THE POP COVERAGE OVER NORTHWEST OHIO. THE HRRR MODEL SEEMS
OVERDONE AS PER MOST MODELS NOT INDICATING MEASURABLE. WILL
MONITOR THIS FOR THE NEXT UPDATE. AIRMASS SEEMS TO STABLE FOR
THAT. NO CHANGE TO LOWS AT THIS TIME.
SHORT WAVE ZIPPING ACROSS THE UPPER GREAT LAKES LATE THIS
AFTERNOON INTO TONIGHT. THE SHORT WAVE WILL DAMPEN OUT AS THE LONG
WAVE RIDGE BUILDS AND IT IS CHASED BY A MORE SIGNIFICANT WAVE
DIGGING INTO THE HIGH PLAINS. NONETHELESS...THERE IS A DECENT LOW
LEVEL JET AND STRONG WARM ADVECTION...ESSENTIALLY A WARM FRONT.
PRETTY COMMON FOR THESE TYPES OF SYSTEMS TO HAVE ENOUGH UPWARD
MOTION TO GET SOME DROPS TO FALL FROM A MID LEVEL CLOUD DECK.
NOTHING SIGNIFICANT...BUT A PASSING SHOWER COULD REACH THE GROUND
ESPECIALLY ACROSS THE NORTHERN COUNTIES TONIGHT.
LOWS WILL BE WARMER THAN RECENT NIGHTS AS THE SOUTH BREEZE WILL
PERSIST. QUITE A BIT OF THE TEMPERATURE DROP WILL BE THIS EVENING
AND TEMPS MIGHT EVEN RISE A DEGREE OR TWO IN THE DOWNSLOPE AND
LAKESHORE AREAS. LOWS WILL DIP TO THE MID OR UPPER 40S IN MOST
AREAS WITH LOWER 40S ACROSS THE COLD SPOTS OF NW PA.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY NIGHT/...
THE MAJORITY OF MID/HIGH CLOUDS SHOULD MOVE EAST OF THE FORECAST
AREA ON WEDNESDAY. SCATTERED CUMULUS/STRATOCUMULUS MAY DEVELOP OVER
EXTREME NE OH/NW PA...OTHERWISE WE SHOULD SEE A FAIR AMOUNT OF
SUNSHINE AND A BRISK SOUTH BREEZE. BOUNDARY LAYER MODEL
TEMPERATURES SUPPORT LOWER AND MID 70S FOR HIGHS AND SEEING THE
CURRENT TEMPERATURES TO OUR WEST IT SEEMS REASONABLE.
THE MODELS ARE GETTING CLOSE ON THEIR TIMING OF THE COLD/OCCLUDED
FRONT ON THURSDAY...ARRIVING TO NORTHWEST OHIO DURING THE EARLY
MORNING HOURS THURSDAY AND PUSHING ACROSS EXTREME NORTHEAST OHIO AND
NORTHWEST PENNSYLVANIA THURSDAY AFTERNOON. EXPECT A GENERAL
DIMINISHING IN THE SHOWERS AS THE FRONT OUT RUNS THE LOW LEVEL JET
AND ENCOUNTERS THE DOWNSLOPE SSE WIND.
SOME CONCERN FOR WIND ON THURSDAY AS THE 850 MB WIND IS PROGGED
BY MOST MODELS TO ABOUT 60 KNOTS. THE TIMING IS NOT GREAT FOR
REACHING THE MAXIMUM WIND AS THE SHOWERS WITH THE FRONT WILL
STABILIZE THE ATMOSPHERE. THERE COULD BE SOME GOOD GUSTS WITH THE
ONSET OF THE SHOWERS AND THERE WILL BE DECENT GUSTS BEHIND THE
FRONT...MOST LIKELY IN THE 35 TO 40 MPH RANGE. WE WILL HAVE TO
CONTINUE TO MONITOR. THE BOUNDARY LAYER REMAINS RATHER WARM ON
THURSDAY BUT IT IS COOLING OFF ALOFT. OFTEN WE CAN SNEAK HIGH
TEMPERATURES A COUPLE DEGREES WARMER THAN ONE WOULD THINK IN THAT
SITUATION AND WILL FORECAST HIGHS GENERALLY IN THE LOWER/MID 60S.
THE UPPER LOW WILL MOVE INTO THE AREA ON FRIDAY AND EXPECT SHOWERS
TO INCREASE. IF IT IS CLOUDY AND SHOWERY THEN TEMPERATURES
WOULD BE COOL...OR IF THERE WILL BE SOME SUNSHINE AND THE SHOWERS
DEVELOP CONVECTIVELY...IT COULD BE WARMER. WILL BE CONSERVATIVE AND
STAY ON THE COOL SIDE AT THIS TIME...WITH FORECAST HIGHS IN THE
50S.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
UPPER TROUGH OVER THE AREA ON SATURDAY WILL ALLOW FOR CONTINUED
CLOUDS AND LIKELY LAKE EFFECT SHOWERS ACROSS FAR NE OH AND NW PA.
THIS TROUGH WILL QUICKLY MOVE TO THE EAST THROUGH SATURDAY NIGHT
WITH RIDGING DEVELOPING OVER THE AREA FOR SUNDAY. COOLER TEMPS
EXPECTED ON SATURDAY WITH THE TROUGH...BUT QUICKLY REBOUNDING ON
SUNDAY WITH READINGS CLIMBING BACK WELL INTO THE 60S FOR THE WEST
AND NEAR 60 FOR THE EAST. HIGH PRESSURE SLIDES OFF TO THE EAST
MONDAY WITH DEVELOPING SOUTH FLOW AND WARM AIR ADVECTION ACROSS THE
AREA.
MODELS CONTINUING TO MAKE CHANGES FOR THE NEXT FRONTAL PASSAGE AT
THE VERY END OF THE PERIOD...WITH LATEST 12Z ECMWF CLOSER TO THE
GFS. FOR NOW ADDED IN POPS MONDAY NIGHT ACROSS THE NORTHERN HALF OF
THE AREA WITH MILD OVERNIGHT TEMPS AHEAD OF THE FRONT.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
NOT MUCH IN THE WAY OF AVIATION IMPACTS TONIGHT. MID/HIGH CLOUDS
TO PASS OVER MAINLY NRN OH/NW PA. THEY MAY HAVE SOME SPOTTY SHOWERS
WITH THEM...BUT WILL MAINTAIN VFR CONDITIONS. THIS IS WITH THE
PASSAGE OF A WARM FRONT. FAIR WEATHER FOR WEDNESDAY. SOUTHERLY
FLOW PICKS UP AND CAN EXPECT GUSTS UPWARDS OF 25 KNOTS.
.OUTLOOK...NON VFR DEVELOPING THURSDAY/THURSDAY NIGHT IN SHOWERS
ASSOCIATED WITH THE NEXT COLD FRONT. NON VFR LINGERING AT TIMES ON
FRIDAY AND SATURDAY AS A TROUGH OF LOW PRESSURE REMAINS OVER THE
GREAT LAKES.
&&
.MARINE...
HIGH PRESSURE OVER THE REGION WILL BUILD TO THE EAST COAST ON
WEDNESDAY. THIS WILL ALLOW SOUTHERLY WINDS TO INCREASE AHEAD OF THE
NEXT LOW PRESSURE SYSTEM. WINDS WILL INCREASE TO 20 TO 25 KNOTS FOR
A PERIOD OF TIME...VEERING TO SOUTHWEST BEHIND THE PASSAGE OF A COLD
FRONT. A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED FOR A PERIOD OF
TIME ON THURSDAY.
THIS BROAD AREA OF LOW PRESSURE WILL SLOWLY DRIFT EAST ACROSS THE
REGION THROUGH THE END OF THE WEEK. HIGH PRESSURE WILL BUILD OVER
THE OHIO VALLEY ON SATURDAY WITH DECREASING WINDS AND WAVES.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KOSARIK
NEAR TERM...KIELTYKA/KOSARIK
SHORT TERM...KOSARIK
LONG TERM...ABE
AVIATION...OUDEMAN
MARINE...KEC
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1052 AM EDT MON OCT 15 2012
.SYNOPSIS...
COLD FRONT EXITS EAST BY LATE MORNING. MUCH COOLER AIR BEHIND IT THIS
AFTERNOON TO SUNDAY. HIGH PRESSURE TUESDAY INTO WEDNESDAY. NEXT
COLD FRONT THURSDAY INTO FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1030AM UPDATE...
-SHRA HAVE PRETTY MUCH COME TO AN END ACROSS CWA ATTM...EXCEPT
SOME -SHRA/DZ ACROSS PORTIONS OF SE OH ASSOCIATED WITH COLD POOL
AND S/W TROF APPROACHING. THIS WILL ROTATE THRU AS DAY WEARS ON
WITH JUST ENOUGH LIFT AND MOISTURE FOR SOME MAINLY DIURNALLY
DRIVEN AFTN SCT -SHRA ACROSS SE OH INTO N WV LOWLANDS AND N MTNS.
COULD BE SOME -DZ ACROSS SE OH AND MTNS...BUT ELECTED TO KEEP THIS
OUT OF WX GRIDS FOR NOW. THIS IS WHERE LOW POPS WERE MAINTAINED
WITH UPDATE. OTHERWISE...LOOKING AT CLD FCST TDY. THINK MINI LLVL
DRY SLOT WORKING THRU WV WILL FILL IN OVER NEXT FEW HRS. ANY
SUNSHINE OVER NEXT FEW HRS ACROSS WV LOWLANDS WILL HELP TO PROLONG
WIND GUSTS UP INTO THE 20KT RANGE.
PREVIOUS DISCUSSION BELOW...
LIGHT CONVECTION ASSOCIATED WITH PASSING COLD FRONT ACROSS THE
EASTERN THIRD OF THE AREA BY 430 AM...EXPECTED TO EXIT EASTERN
MOUNTAINS BY 7 AM. SFC OBS INDICATED A WIND SHIFT WITH THIS LINE
OF CONVECTION...HOWEVER...DEWPOINTS GRADIENT REMAINS ACROSS
SOUTHEAST OH. AN UPPER LEVEL TROUGH...WITH DESCENT VORTICITY MAX
WILL PASS OVERHEAD THIS AFTERNOON...AND COULD SQUEEZE SOME OF THE
LINGERING MOISTURE INTO ADDITIONAL LIGHT SHOWERS...AND PUSH THE
ACTUAL FRONT EAST OF THE APPALACHIANS AS WELL. THE SFC LOW
PRESSURE OVER THE GREAT LAKES REGION LIFTS NORTHEAST TODAY...BUT
SOME RAP AROUND MOISTURE AND COLDER TEMPS AT H850 WILL STILL UNDER
THE INFLUENCE OF THE AFOREMENTIONED UPPER TROUGH.
SFC HIGH PRESSURE BUILDS BEHIND THE FRONT BUILDS TONIGHT INTO
TUESDAY TO BRING COLDER TEMPERATURES TONIGHT...GENERALLY INTO THE
UPPER 30S EXTREME NORTHWEST...RANGING INTO THE LOWER 40S HIGHER
ELEVATIONS AS THE FREEZING LINE AT H850 APPROACHES FROM THE
NORTHWEST.
WINDS WILL DECREASE SOME TODAY...TURNING WEST NORTHWEST...WITH FEW
WIND GUSTS OVER THE HIGHER TERRAIN THROUGH THE AFTERNOON HOURS.
WENT WITH A BLEND OF MAV AND MET TEMPERATURES THROUGH THE PERIOD.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
RISING HEIGHTS WITH NW FLOW ALOFT AND SFC HIGH PRESSURE WILL BE
BUILDING INTO THE AREA TUESDAY AS THE UPPER TROUGH CONTINUES TO MOVE
TO THE NORTHEAST. AFTER SOME LINGERING EARLY MORNING CLOUDS AND
PERHAPS A FEW LIGHT SPRINKLES ACROSS THE NORTHEAST HIGH COUNTRY...A
PLEASANTLY COOL DAY UNDER MOSTLY SUNNY SKIES WILL BE IN STORE FOR
THE FORECAST AREA. INHERITED MAX TEMPS IN THE LOW/MID 60S LOWLANDS
AND AROUND 50F FOR THE HIGHEST LOCALES SUCH AS SNOWSHOE LOOK GOOD.
SFC HIGH PRESSURE WILL BEGIN TO SLIDE OFF TO THE EAST OVERNIGHT TUE
NIGHT/EARLY WED. WITH SOME MODEST WARM ADVECTION NOTED AT 850MB AND
SFC WINDS BACKING FROM THE WEST TO THE SOUTH/SOUTHEAST...DID NUDGE
OVERNIGHT LOWS UP GENERALLY BY A COUPLE OF DEGREES.
BY WEDNESDAY ZONAL FLOW ALOFT TRANSITIONS TO SOUTHWESTERLY BY END OF
DAY WITH THE APPROACH OF THE NEXT UPPER LEVEL TROUGH MOVING SE-WARD
ACROSS THE UPPER MIDWEST. A QUICK MOVING S/W TROUGH IN THE MEAN FLOW
WILL SKIRT ACROSS THE SOUTHERN GREAT LAKES AREA TO THE NORTH WED
MORNING...BUT SHOULD ONLY RESULT IN INCREASED MID-LEVEL CLOUDS
MAINLY DURING THE MORNING HOURS. WARMER TEMPS WILL MOVE INTO THE AREA
AS THE SFC HIGH PRESSURE CONTINUES TO MOVE EAST OF AREA. WITH 850MB
TEMPS OF AROUND 10C-11C PROGGED...INHERITED MAX TEMPS IN THE
MID/UPPER 70S LOWLANDS STILL LOOK GOOD WITH A FEW MINOR TWEAKS.
BY THURSDAY THE UPPER LEVEL LOW ACROSS THE MIDWEST ACROSS THE
WESTERN GREAT LAKES WHILE ITS ATTENDANT SFC LOW DEEPENS AND
PINWHEELS AROUND IT PUSHING NORTHWARD ROUGHLY AROUND LAKE SUPERIOR
OR NORTH. CONSIDERABLE DIFFERENCES WITH THE TIMING AND LOCATION OF
UPPER LOW AND SFC FRONT STILL EXIST...WITH THE NAM/EC SLOWER AND GFS
AND OTHERS AMONG THE FASTER SOLUTIONS. THERE APPEARS TO BE DECENT
ENSEMBLE SUPPORT WITH THE SLOWER SOLN/S AND WILL LEAN THE FORECAST
IN THIS DIRECTION...BRINGING POPS INTO THE NW ZONES BY 12Z THU WITH
HIGHER POPS LATER THURSDAY. STILL...WITH THE UNCERTAINTIES WILL CAP
POPS ONLY AT HIGH CHANCE. DID ELECT TO NUDGE MAX TEMPS DOWN SLIGHTLY
WITH 850MB TEMP GUIDANCE DEPICTING THU PM TEMPS OF AROUND 6C-7C.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
OVERALL UNSETTLED WEATHER PATTERN IN THE LONG TERM...WITH MODELS
STARTING TO COME INTO BETTER AGREEMENT THAN IN PREVIOUS RUNS. PERIOD
STARTS OUT WITH AN UPPER TROUGH DEEPENING OVER THE MIDWEST...AND
EVENTUALLY SWINGING A COLD FRONT THROUGH THE AREA EITHER THURSDAY OR
FRIDAY. THIS WILL BRING AN INCREASE IN SHOWER...AND ISOLD
THUNDERSTORM ACTIVITY...AS WELL AS WARMING TEMPERATURES OUT AHEAD OF
THE FRONT. AFTER FRONT EXITS TO THE EAST...UPPER LEVEL LOW WILL
DEEPEN ACROSS THE U.S...AND AFFECT THE AREA OVER THE NEXT SEVERAL
DAYS. ECMWF IS STARTING TO COME INTO LINE A BIT BETTER WITH THE
GFS...WITH LOW DEEPENING ACROSS THE UPPER MIDWEST...KEEPING THE AREA
IN A WARM SOUTHWESTERLY FLOW...UNTIL IT FINALLY KICKS OFF TO THE
EAST LATE IN THE WEEK. ECMWF IS STILL A LITTLE DEEPER WITH THIS
TROUGH ACROSS THE U.S. THAN THE GFS...BUT OVERALL...MODELS STARTING
TO COME INTO AGREEMENT.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
IFR CLOUD DECK AROUND 1500 FEET WILL AFFECT THE MOUNTAINS SITES
THIS MORNING...AS A COLD FRONT PUSHES EAST BY 15Z. ALTHOUGH THERE
HAS BEEN A WIND SHIFT FROM SOUTHWEST TO WEST NORTHWEST IN THE
LOWER LEVELS....DEWPOINTS GRADIENT CONTINUES ACROSS SOUTHEAST OH
SUGGESTING THE ELUSIVE COLD FRONT MAY STAY CLOSE TO THE OH RIVER
BY 11Z. MODELS CONTINUE TO SHOW LOW LEVEL FLOW TURNING MORE
NORTHWEST BRINGING COLDER AND DRIER AIR...TO SQUEEZE ANY MOISTURE
IN A FORM OF LOW CLOUDS OR FEW SPRINKLES OUT THIS AFTERNOON...AS A
VORTICITY MAX ASSOCIATED WITH AT HIGH AMPLITUDE H5 TROUGH SWEEPS
THE AREA THIS AFTERNOON.
THEREFORE...EXPECT MVFR CEILINGS UNDER AREAS OF RAIN MAINLY
ACROSS THE NORTHERN SITES...AND PERHAPS NORTHEAST MOUNTAINS THROUGH
THIS AFTERNOON.
HIGH PRESSURE BUILDS OVERHEAD...TAKING CONTROL EARLY TUESDAY AND
WEDNESDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: DURATION OF LOW LEVEL DECK AROUND 1500 FEET
OVER THE MOUNTAINS AND NORTHERN SECTIONS COULD VARY. TIMING ON
TRANSITIONS TO/FROM MVFR COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY H H H M M M H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H M M M H M H H H
EKN CONSISTENCY H H H M M M M M M M M M
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H M M H H H H H
AFTER 12Z TUESDAY...
NO WIDESPREAD IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50
NEAR TERM...ARJ/30
SHORT TERM...50
LONG TERM...SL
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
642 AM EDT MON OCT 15 2012
.SYNOPSIS...
COLD FRONT EXITS EAST BY LATE MORNING. MUCH COOLER AIR BEHIND IT THIS
AFTERNOON TO SUNDAY. HIGH PRESSURE TUESDAY INTO WEDNESDAY. NEXT
COLD FRONT THURSDAY INTO FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
LIGHT CONVECTION ASSOCIATED WITH PASSING COLD FRONT ACROSS THE
EASTERN THIRD OF THE AREA BY 430 AM...EXPECTED TO EXIT EASTERN
MOUNTAINS BY 7 AM. SFC OBS INDICATED A WIND SHIFT WITH THIS LINE
OF CONVECTION...HOWEVER...DEWPOINTS GRADIENT REMAINS ACROSS
SOUTHEAST OH. AN UPPER LEVEL TROUGH...WITH DESCENT VORTICITY MAX
WILL PASS OVERHEAD THIS AFTERNOON...AND COULD SQUEEZE SOME OF THE
LINGERING MOISTURE INTO ADDITIONAL LIGHT SHOWERS...AND PUSH THE
ACTUAL FRONT EAST OF THE APPALACHIANS AS WELL. THE SFC LOW
PRESSURE OVER THE GREAT LAKES REGION LIFTS NORTHEAST TODAY...BUT
SOME RAP AROUND MOISTURE AND COLDER TEMPS AT H850 WILL STILL UNDER
THE INFLUENCE OF THE AFOREMENTIONED UPPER TROUGH.
SFC HIGH PRESSURE BUILDS BEHIND THE FRONT BUILDS TONIGHT INTO
TUESDAY TO BRING COLDER TEMPERATURES TONIGHT...GENERALLY INTO THE
UPPER 30S EXTREME NORTHWEST...RANGING INTO THE LOWER 40S HIGHER
ELEVATIONS AS THE FREEZING LINE AT H850 APPROACHES FROM THE
NORTHWEST.
WINDS WILL DECREASE SOME TODAY...TURNING WEST NORTHWEST...WITH FEW
WIND GUSTS OVER THE HIGHER TERRAIN THROUGH THE AFTERNOON HOURS.
WENT WITH A BLEND OF MAV AND MET TEMPERATURES THROUGH THE PERIOD.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
RISING HEIGHTS WITH NW FLOW ALOFT AND SFC HIGH PRESSURE WILL BE
BUILDING INTO THE AREA TUESDAY AS THE UPPER TROUGH CONTINUES TO MOVE
TO THE NORTHEAST. AFTER SOME LINGERING EARLY MORNING CLOUDS AND
PERHAPS A FEW LIGHT SPRINKLES ACROSS THE NORTHEAST HIGH COUNTRY...A
PLEASANTLY COOL DAY UNDER MOSTLY SUNNY SKIES WILL BE IN STORE FOR
THE FORECAST AREA. INHERITED MAX TEMPS IN THE LOW/MID 60S LOWLANDS
AND AROUND 50F FOR THE HIGHEST LOCALES SUCH AS SNOWSHOE LOOK GOOD.
SFC HIGH PRESSURE WILL BEGIN TO SLIDE OFF TO THE EAST OVERNIGHT TUE
NIGHT/EARLY WED. WITH SOME MODEST WARM ADVECTION NOTED AT 850MB AND
SFC WINDS BACKING FROM THE WEST TO THE SOUTH/SOUTHEAST...DID NUDGE
OVERNIGHT LOWS UP GENERALLY BY A COUPLE OF DEGREES.
BY WEDNESDAY ZONAL FLOW ALOFT TRANSITIONS TO SOUTHWESTERLY BY END OF
DAY WITH THE APPROACH OF THE NEXT UPPER LEVEL TROUGH MOVING SE-WARD
ACROSS THE UPPER MIDWEST. A QUICK MOVING S/W TROUGH IN THE MEAN FLOW
WILL SKIRT ACROSS THE SOUTHERN GREAT LAKES AREA TO THE NORTH WED
MORNING...BUT SHOULD ONLY RESULT IN INCREASED MID-LEVEL CLOUDS
MAINLY DURING THE MORNING HOURS. WARMER TEMPS WILL MOVE INTO THE AREA
AS THE SFC HIGH PRESSURE CONTINUES TO MOVE EAST OF AREA. WITH 850MB
TEMPS OF AROUND 10C-11C PROGGED...INHERITED MAX TEMPS IN THE
MID/UPPER 70S LOWLANDS STILL LOOK GOOD WITH A FEW MINOR TWEAKS.
BY THURSDAY THE UPPER LEVEL LOW ACROSS THE MIDWEST ACROSS THE
WESTERN GREAT LAKES WHILE ITS ATTENDANT SFC LOW DEEPENS AND
PINWHEELS AROUND IT PUSHING NORTHWARD ROUGHLY AROUND LAKE SUPERIOR
OR NORTH. CONSIDERABLE DIFFERENCES WITH THE TIMING AND LOCATION OF
UPPER LOW AND SFC FRONT STILL EXIST...WITH THE NAM/EC SLOWER AND GFS
AND OTHERS AMONG THE FASTER SOLUTIONS. THERE APPEARS TO BE DECENT
ENSEMBLE SUPPORT WITH THE SLOWER SOLN/S AND WILL LEAN THE FORECAST
IN THIS DIRECTION...BRINGING POPS INTO THE NW ZONES BY 12Z THU WITH
HIGHER POPS LATER THURSDAY. STILL...WITH THE UNCERTAINTIES WILL CAP
POPS ONLY AT HIGH CHANCE. DID ELECT TO NUDGE MAX TEMPS DOWN SLIGHTLY
WITH 850MB TEMP GUIDANCE DEPICTING THU PM TEMPS OF AROUND 6C-7C.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
OVERALL UNSETTLED WEATHER PATTERN IN THE LONG TERM...WITH MODELS
STARTING TO COME INTO BETTER AGREEMENT THAN IN PREVIOUS RUNS. PERIOD
STARTS OUT WITH AN UPPER TROUGH DEEPENING OVER THE MIDWEST...AND
EVENTUALLY SWINGING A COLD FRONT THROUGH THE AREA EITHER THURSDAY OR
FRIDAY. THIS WILL BRING AN INCREASE IN SHOWER...AND ISOLD
THUNDERSTORM ACTIVITY...AS WELL AS WARMING TEMPERATURES OUT AHEAD OF
THE FRONT. AFTER FRONT EXITS TO THE EAST...UPPER LEVEL LOW WILL
DEEPEN ACROSS THE U.S...AND AFFECT THE AREA OVER THE NEXT SEVERAL
DAYS. ECMWF IS STARTING TO COME INTO LINE A BIT BETTER WITH THE
GFS...WITH LOW DEEPENING ACROSS THE UPPER MIDWEST...KEEPING THE AREA
IN A WARM SOUTHWESTERLY FLOW...UNTIL IT FINALLY KICKS OFF TO THE
EAST LATE IN THE WEEK. ECMWF IS STILL A LITTLE DEEPER WITH THIS
TROUGH ACROSS THE U.S. THAN THE GFS...BUT OVERALL...MODELS STARTING
TO COME INTO AGREEMENT.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
IFR CLOUD DECK AROUND 1500 FEET WILL AFFECT THE MOUNTAINS SITES
THIS MORNING...AS A COLD FRONT PUSHES EAST BY 15Z. ALTHOUGH THERE
HAS BEEN A WIND SHIFT FROM SOUTHWEST TO WEST NORTHWEST IN THE
LOWER LEVELS....DEWPOINTS GRADIENT CONTINUES ACROSS SOUTHEAST OH
SUGGESTING THE ELUSIVE COLD FRONT MAY STAY CLOSE TO THE OH RIVER
BY 11Z. MODELS CONTINUE TO SHOW LOW LEVEL FLOW TURNING MORE
NORTHWEST BRINGING COLDER AND DRIER AIR...TO SQUEEZE ANY MOISTURE
IN A FORM OF LOW CLOUDS OR FEW SPRINKLES OUT THIS AFTERNOON...AS A
VORTICITY MAX ASSOCIATED WITH AT HIGH AMPLITUDE H5 TROUGH SWEEPS
THE AREA THIS AFTERNOON.
THEREFORE...EXPECT MVFR CEILINGS UNDER AREAS OF RAIN MAINLY
ACROSS THE NORTHERN SITES...AND PERHAPS NORTHEAST MOUNTAINS THROUGH
THIS AFTERNOON.
HIGH PRESSURE BUILDS OVERHEAD...TAKING CONTROL EARLY TUESDAY AND
WEDNESDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: DURATION OF LOW LEVEL DECK AROUND 1500 FEET
OVER THE MOUNTAINS AND NORTHERN SECTIONS COULD VARY. TIMING ON
TRANSITIONS TO/FROM MVFR COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EDT 1HRLY 07 08 09 10 11 12 13 14 15 16 17 18
CRW CONSISTENCY M M M M M M M M M H H H
HTS CONSISTENCY M M M M H M M H H H H H
BKW CONSISTENCY H M M H M M M M M M H M
EKN CONSISTENCY M H H M H M M M M M M M
PKB CONSISTENCY H H M H H H M H H H H H
CKB CONSISTENCY M M M H M M M M M M H H
AFTER 12Z TUESDAY...
NO WIDESPREAD IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50
NEAR TERM...ARJ
SHORT TERM...50
LONG TERM...SL
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
426 AM EDT MON OCT 15 2012
.SYNOPSIS...
COLD FRONT EXITS EAST BY LATE MORNING. MUCH COOLER AIR BEHIND IT THIS
AFTERNOON TO SUNDAY. HIGH PRESSURE TUESDAY INTO WEDNESDAY. NEXT
COLD FRONT THURSDAY INTO FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
LIGHT CONVECTION ASSOCIATED WITH PASSING COLD FRONT ACROSS THE
EASTERN THIRD OF THE AREA BY 430 AM...EXPECTED TO EXIT EASTERN
MOUNTAINS BY 7 AM. SFC OBS INDICATED A WIND SHIFT WITH THIS LINE
OF CONVECTION...HOWEVER...DEWPOINTS GRADIENT REMAINS ACROSS
SOUTHEAST OH. AN UPPER LEVEL TROUGH...WITH DESCENT VORTICITY MAX
WILL PASS OVERHEAD THIS AFTERNOON...AND COULD SQUEEZE SOME OF THE
LINGERING MOISTURE INTO ADDITIONAL LIGHT SHOWERS...AND PUSH THE
ACTUAL FRONT EAST OF THE APPALACHIANS AS WELL. THE SFC LOW
PRESSURE OVER THE GREAT LAKES REGION LIFTS NORTHEAST TODAY...BUT
SOME RAP AROUND MOISTURE AND COLDER TEMPS AT H850 WILL STILL UNDER
THE INFLUENCE OF THE AFOREMENTIONED UPPER TROUGH.
SFC HIGH PRESSURE BUILDS BEHIND THE FRONT BUILDS TONIGHT INTO
TUESDAY TO BRING COLDER TEMPERATURES TONIGHT...GENERALLY INTO THE
UPPER 30S EXTREME NORTHWEST...RANGING INTO THE LOWER 40S HIGHER
ELEVATIONS AS THE FREEZING LINE AT H850 APPROACHES FROM THE
NORTHWEST.
WINDS WILL DECREASE SOME TODAY...TURNING WEST NORTHWEST...WITH FEW
WIND GUSTS OVER THE HIGHER TERRAIN THROUGH THE AFTERNOON HOURS.
WENT WITH A BLEND OF MAV AND MET TEMPERATURES THROUGH THE PERIOD.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
RISING HEIGHTS WITH NW FLOW ALOFT AND SFC HIGH PRESSURE WILL BE
BUILDING INTO THE AREA TUESDAY AS THE UPPER TROUGH CONTINUES TO MOVE
TO THE NORTHEAST. AFTER SOME LINGERING EARLY MORNING CLOUDS AND
PERHAPS A FEW LIGHT SPRINKLES ACROSS THE NORTHEAST HIGH COUNTRY...A
PLEASANTLY COOL DAY UNDER MOSTLY SUNNY SKIES WILL BE IN STORE FOR
THE FORECAST AREA. INHERITED MAX TEMPS IN THE LOW/MID 60S LOWLANDS
AND AROUND 50F FOR THE HIGHEST LOCALES SUCH AS SNOWSHOE LOOK GOOD.
SFC HIGH PRESSURE WILL BEGIN TO SLIDE OFF TO THE EAST OVERNIGHT TUE
NIGHT/EARLY WED. WITH SOME MODEST WARM ADVECTION NOTED AT 850MB AND
SFC WINDS BACKING FROM THE WEST TO THE SOUTH/SOUTHEAST...DID NUDGE
OVERNIGHT LOWS UP GENERALLY BY A COUPLE OF DEGREES.
BY WEDNESDAY ZONAL FLOW ALOFT TRANSITIONS TO SOUTHWESTERLY BY END OF
DAY WITH THE APPROACH OF THE NEXT UPPER LEVEL TROUGH MOVING SE-WARD
ACROSS THE UPPER MIDWEST. A QUICK MOVING S/W TROUGH IN THE MEAN FLOW
WILL SKIRT ACROSS THE SOUTHERN GREAT LAKES AREA TO THE NORTH WED
MORNING...BUT SHOULD ONLY RESULT IN INCREASED MID-LEVEL CLOUDS
MAINLY DURING THE MORNING HOURS. WARMER TEMPS WILL MOVE INTO THE AREA
AS THE SFC HIGH PRESSURE CONTINUES TO MOVE EAST OF AREA. WITH 850MB
TEMPS OF AROUND 10C-11C PROGGED...INHERITED MAX TEMPS IN THE
MID/UPPER 70S LOWLANDS STILL LOOK GOOD WITH A FEW MINOR TWEAKS.
BY THURSDAY THE UPPER LEVEL LOW ACROSS THE MIDWEST ACROSS THE
WESTERN GREAT LAKES WHILE ITS ATTENDANT SFC LOW DEEPENS AND
PINWHEELS AROUND IT PUSHING NORTHWARD ROUGHLY AROUND LAKE SUPERIOR
OR NORTH. CONSIDERABLE DIFFERENCES WITH THE TIMING AND LOCATION OF
UPPER LOW AND SFC FRONT STILL EXIST...WITH THE NAM/EC SLOWER AND GFS
AND OTHERS AMONG THE FASTER SOLUTIONS. THERE APPEARS TO BE DECENT
ENSEMBLE SUPPORT WITH THE SLOWER SOLN/S AND WILL LEAN THE FORECAST
IN THIS DIRECTION...BRINGING POPS INTO THE NW ZONES BY 12Z THU WITH
HIGHER POPS LATER THURSDAY. STILL...WITH THE UNCERTAINTIES WILL CAP
POPS ONLY AT HIGH CHANCE. DID ELECT TO NUDGE MAX TEMPS DOWN SLIGHTLY
WITH 850MB TEMP GUIDANCE DEPICTING THU PM TEMPS OF AROUND 6C-7C.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
OVERALL UNSETTLED WEATHER PATTERN IN THE LONG TERM...WITH MODELS
STARTING TO COME INTO BETTER AGREEMENT THAN IN PREVIOUS RUNS. PERIOD
STARTS OUT WITH AN UPPER TROUGH DEEPENING OVER THE MIDWEST...AND
EVENTUALLY SWINGING A COLD FRONT THROUGH THE AREA EITHER THURSDAY OR
FRIDAY. THIS WILL BRING AN INCREASE IN SHOWER...AND ISOLD
THUNDERSTORM ACTIVITY...AS WELL AS WARMING TEMPERATURES OUT AHEAD OF
THE FRONT. AFTER FRONT EXITS TO THE EAST...UPPER LEVEL LOW WILL
DEEPEN ACROSS THE U.S...AND AFFECT THE AREA OVER THE NEXT SEVERAL
DAYS. ECMWF IS STARTING TO COME INTO LINE A BIT BETTER WITH THE
GFS...WITH LOW DEEPENING ACROSS THE UPPER MIDWEST...KEEPING THE AREA
IN A WARM SOUTHWESTERLY FLOW...UNTIL IT FINALLY KICKS OFF TO THE
EAST LATE IN THE WEEK. ECMWF IS STILL A LITTLE DEEPER WITH THIS
TROUGH ACROSS THE U.S. THAN THE GFS...BUT OVERALL...MODELS STARTING
TO COME INTO AGREEMENT.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
CONVECTION ASSOCIATED WITH COLD FRONT EVIDENT ON RADAR IMAGES AND
SFC OBS ACROSS HTS...NORTH NORTHEAST TO JUST WEST OF PKB BY
06Z...WILL PRODUCE BRIEF PERIODS OF IFR VISIBILITIES UNDER
MODERATE TO HEAVY RAIN. BRIEF PERIODS OF STRONG GUSTY WINGS ARE
POSSIBLE JUST AHEAD OF THE FRONT REACHING 25-30 KNOTS AS WELL.
THE FRONT WILL ADVANCE QUICKLY EAST TO REACH CRW BY
0630-07Z...AND THE REST OF EASTERN SITES BY 09-10Z. EXPECT
STRONGER WINDS AT HIGHER ELEVATIONS OVERNIGHT AS THE COLD FRONT
PASSES THROUGH. VFR CONDITIONS WILL PREVAIL...EXCEPT IFR ALONG
STRONG SHOWERS...BUT WILL LAST LEST THAN 40 MINUTES. MVFR
CEILINGS WILL FOLLOW BEHIND THE FRONT ABOUT 2500 FEET.
FRONT EXITS THE MOUNTAINS AROUND 12Z. BEHIND THE FRONT...SCATTERED
SHOWERS WILL CONTINUE THRU THE DAY MAINLY NORTHERN SITES. MVFR
CEILINGS...LINGERING INTO MONDAY.
HIGH PRESSURE BUILDS OVERHEAD TAKING CONTROL EARLY TUESDAY AND
WEDNESDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF STRONG WIND ALOFT AND MIXING DOWN TO
SFC WITH CONVECTION COULD VARY. TIMING ON TRANSITIONS TO/FROM MVFR
COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 10/15/12
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EDT 1HRLY 04 05 06 07 08 09 10 11 12 13 14 15
CRW CONSISTENCY M M M H H H M M M M M M
HTS CONSISTENCY M M M M M M M M M M H H
BKW CONSISTENCY H H H H H H M M M M M M
EKN CONSISTENCY H H H H H H M M H H M M
PKB CONSISTENCY M H H H H H H H M M H H
CKB CONSISTENCY H H M H H H M M H M M M
AFTER 06Z TUESDAY...
NO WIDESPREAD IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50
NEAR TERM...ARJ
SHORT TERM...50
LONG TERM...SL
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
640 PM EDT MON OCT 15 2012
.SYNOPSIS...
A COLD FRONT OVER FAR EASTERN PENNSYLVANIA THIS EVENING WILL EXIT
OFF THE MID ATLANTIC COAST OVERNIGHT. MAINLY DRY AND MILD WEATHER
WILL FOLLOW FOR THE MID-WEEK PERIOD. A DEEP UPPER LEVEL LOW WILL
DEVELOP OVER THE UPPER PLAINS AND MIDWEST OVER THE NEXT FEW DAYS.
THE DEEP LOW WILL THEN MOVE TO THE EAST AND PUSH A COLD FRONT
THROUGH LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
SFC COLD FRONT IS CURRENTLY APPROACHING THE DELAWARE VALLEY AND
WILL MOVE OFF THE MID ATLANTIC COAST OVERNIGHT. STRATIFORM RAIN
HAS EXITED OUR FAR SERN ZONES...FOLLOWED BY SOME PARTIAL CLEARING
AS LLVL DOWNSLOPE WESTERLY FLOW KICKS IN ACROSS THE CENTRAL MTS
AND SUSQ VALLEY THIS EVENING...AND THE DEEPER LIFT ALOFT WANES
AS THE LEFT ENTRANCE REGION OF A NORTH/SOUTH 115 KT UPPER JET
DRAGS ACROSS CENTRAL PENN AND THE SUSQUEHANNA REGION.
FURTHER WEST...STRONG MID LEVEL /700-500MB/ COLD ADVECTION AND A
POCKET OF STEEP 850-700 MB LAPSE RATES WAS SUPPORTING AN AREA OF
LIGHT TO MODERATE RAIN SHOWERS MOVING ACROSS THE WEST CENTRAL MTNS
AND LAUREL HIGHLANDS. LATEST HRRR GUIDANCE SHOWS THIS AREA OF
SHOWERS DWINDLING AS IT MOVES EAST OF THE ALLEGHENY FRONT BETWEEN
23-01Z.
RAINFALL AMOUNTS ACROSS THE SW 1/4 OF THE CWA WILL RANGE FROM JUST
A FEW HUNDREDTHS...TO AROUND 0NE TENTH OF AN INCH IN SOME SPOTS.
THIS POCKET OF COLD AIR ALOFT WITH 700 MB TEMPS INITIALLY AROUND
-8C EARLY THIS EVENING...WILL GRADUALLY FILL/WARM BY 3-4C AS IT
CROSSES CENTRAL PENN...AND REACHES THE SUSQ VALLEY LATE TONIGHT.
A FEW BRIEF SHOWERS ARE POSSIBLE THROUGH EARLY TONIGHT ACROSS THE
CENTRAL RIDGE AND VALLEY REGION /MORE LIKELY SPRINKLES/...BUT MOST
LOCATIONS WILL NOT SEE ENOUGH RAIN TO WET THE GROUND.
GUSTY WEST WINDS ACROSS THE CENTRAL AND WESTERN ZONES
AT DUSK WILL SLACKEN OFF BY MIDNIGHT...BUT THEY WON/T GO CALM
OVERNIGHT CONSIDERING THAT THE RIDGE AXIS IS STILL SEVERAL HUNDRED
MILES OFF TO THE WEST.
THE MOISTURE LAYER BECOMES THINNER AS SUBSIDENCE INCREASES AND
UPPER HEIGHTS RISE LATE TONIGHT....AND PRACTICALLY ALL OF THE
SHOWERS WILL HAVE ENDED BY 07-09Z TUESDAY /EXCEPT FOR THE
LINGERING LAKE EFFECT VARIETY NEAR AND TO THE WEST OF KBFD/.
LOWS TONIGHT WILL BE RIGHT AROUND NORMAL WITH M-U30S ACROSS THE NW
AND M40S IN THE SE.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
ANY ISOLD SHRA IN THE NW SHOULD BE DONE AROUND SUNRISE TUES...SO
WILL KEEP POPS NIL AREAWIDE FOR THE DAYTIME. DAYTIME TEMPS WILL
REMAIN VERY CLOSE TO SEASONAL NORMALS...TOPPING OUT IN THE M50S-
M60S. RIDGE AXIS STILL OFF TO THE WEST IN THE MORNING...BUT
OVERHEAD LATE IN THE DAY...SO WINDS SHOULD BEGIN 8-10KTS AND COULD
INCREASE/GUST A LITTLE BUT THEN LIGHTEN UP - ESP IN THE W -
THROUGH THE AFTN. AN UNEVENTFUL BUT TYPICAL AUTUMN DAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
SFC HIGH PRESSURE RIDGE OVER THE REGION FOR MIDWEEK WITH WESTERLY
FLOW TURNING SW ALOFT AHEAD OF DEVELOPING TROUGH. SO DRY WEATHER
WILL PREVAIL TUE NIGHT INTO THU. CHILLY NIGHT TUE NIGHT WITH LOWS IN
THE 30S...BUT RETURN FLOW ON BACK SIDE OF HIGH WILL PUSH TEMPS
SLIGHTLY ABOVE NORMAL ON WED. MILDER NIGHT WED NIGHT...THEN
INCREASING CLOUD COVER WILL BRING SEASONAL TEMPS FOR THU.
TROUGH EDGES TOWARD PA LATE WEEK...WITH FRONT RUNNING OUT AHEAD OF
SYSTEM FOR THU NIGHT/FRI BRINGING BEST CHANCE FOR WIDESPREAD RAIN
THIS WEEK. EASTERN SECTIONS COULD SEE HIGHEST AMOUNTS...WITH QPF
AROUND 0.25 INCHES...POSS UP TO 0.75 INCHES ON EASTERN EDGE.
UNFORTUNATELY...MODELS REMAIN STEADFAST IN THEIR DIFFERENCES THIS
WEEKEND WITH GFS REMAINING WEAKER AND MORE PROGRESSIVE WHILE THE
ECMWF STICKS WITH A LARGER AND SLOWER MOVING LOW. SO FORECAST
CONTINUES TO TRY TO MITIGATE THESE DIFFERENCES INTO A COMPROMISE
SOLUTION. AFTER BEST RAIN CHANCES CENTERED ON FRIDAY...KEPT SCT
SHOWERS POSS INTO THE WEEKEND WITH DRYING TREND LATE. TEMPS DO
COOL OFF A BIT OVER THE WEEKEND INTO EARLY NEXT WEEK...BUT REMAIN
CLOSE TO SEASONAL AVERAGES.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
COLD FRONT HAS PUSHED EAST OF THE REGION THIS EVENING AND
DOWNSLOPING WESTERLY FLOW IN IT/S WAKE IS PRODUCING CLEARING SKIES
ACROSS PORTIONS OF THE SUSQ VALLEY. RESIDUAL LOW LVL MOISTURE
ASCENDING THE W MTNS WILL PRODUCE PERSISTENT MVFR STRATO-CU AT
BFD AND JST OVERNIGHT WITH SREF DATA EVEN SUGGESTING THE POSSIBILITY
OF CIGS DIPPING TO IFR LATE TONIGHT. A FEW SHRA NOTED ON RADAR
ACROSS WESTERN PA AT 21Z ASSOC WITH APPROACH OF UPPER LVL TROUGH.
THESE SHRA SHOULD BE CONFINED MAINLY THE W MTNS THIS EVENING.
WHERE SKIES REMAIN CLOUDY...ATMOS WILL REMAIN WELL MIXED AND FAVOR
FREQUENT WIND GUSTS TO NR 20KTS OVERNIGHT ACROSS THE W MTNS.
DOWNSLOPING FLOW EAST OF THE MTNS WILL RESULT IN BRKS IN THE
OVERCAST...SOME RAD COOLING AND LIGHTER WIND SPEEDS.
SOME EARLY LOW CIGS ARE POSSIBLE TO START TUESDAY. HOWEVER...HIGH
PRES BUILDING INTO THE STATE SUPPORTS A HIGH CONFIDENCE FCST OF
VFR CONDS EVERYWHERE BY MIDDAY.
OUTLOOK...
WED-EARLY THUR...NO SIG WX EXPECTED.
LATE THU-FRI...FROPA WITH RAIN/LOW CIGS POSSIBLE.
SAT...BREEZY WITH MVFR CIGS W...VFR ELSEWHERE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...DANGELO/LAMBERT
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...DANGELO/FITZGERALD
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1147 PM CDT SUN OCT 14 2012
.DISCUSSION...
SEE 06Z TAF DISCUSSION...
&&
.AVIATION...
COLD FRONT VERY SLOWLY CREEPING IN TO HOUSTON METRO AREA.
ADDED PRE-FRONTAL VCSH TO TERMINALS FROM IAH EASTWARD. ISOLATED
LIGHT RAIN SHOWERS ARE POPPING UP AS THE FRONT APPROACHES THE
COAST. EXPECT LOW CIGS CLEARING AT IAH BY 08Z...HOU BY 09Z...AND
GLS BY 13Z.
BEHIND THE FRONT...CLEAR SKIES...UNLIMITED VISIBILITY...AND NORTH
WINDS BETWEEN 5-10 KNOTS SHOULD PREVAIL. 44
&&
.PREV DISCUSSION... /ISSUED 942 PM CDT SUN OCT 14 2012/
DISCUSSION...
AT 9 PM THE COLD FRONT HAD MOVE THROUGH CROCKETT...MADISONVILLE...
COLLEGE STATION. SHOWER AND THUNDERSTORM ACTIVITY HAD DIMINISHED
OVER THE PAST COUPLE OF HOURS...HOWEVER BETWEEN 9 AND 930 PM
ISOLATED SHOWERS WERE BEGINNING TO DEVELOP ALONG A PREFRONTAL
TROUGH IN THE METRO HOUSTON AREA.
A LOOK AT THE 00Z UPPER AIR ANALYSES SHOWS THAT THE BEST 700 MB
MOISTURE WAS JUST TO THE EAST AND WEST OF THE FORECAST AREA.
HOWEVER...850 MB DEWPOINTS WERE BETWEEN 12 AND 14 CELCIUS. THE
LATEST RAP MODEL ALSO SHOWS THE BEST LOW-LEVEL CONVERGENCE OVER
THE SE TX COASTAL AREAS.
WITH THIS IN MIND...WILL ADJUST THE POPS SLIGHTLY DOWNWARD FOR THE
REMAINDER OF THIS EVENING...MAINLY TO ACCOUNT FOR THE LOCATION OF
THE FRONT AND THE CURRENT LACK OF SHOWER ACTIVITY. DO THINK THAT
BETTER COVERAGE WILL OCCUR AS THE FRONT MOVES INTO THE BETTER
MOISTURE ALONG THE COAST...AND WILL KEEP THE OVERNIGHT POPS IN
PLACE.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 59 84 59 81 64 / 10 10 0 10 10
HOUSTON (IAH) 65 86 59 83 64 / 30 10 0 10 10
GALVESTON (GLS) 73 83 70 82 73 / 30 10 0 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...40
AVIATION/MARINE...44
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1052 PM PDT Sun Oct 14 2012
.SYNOPSIS...Rain is expected to spread over the remainder of the
Inland Northwest tonight, as a cold front moves through the region.
A strong storm will arrive early Tuesday morning, bringing widespread
rain and windy conditions. Wind gusts of 35 to 45 mph will be
likely on Tuesday afternoon over portions of the Inland Northwest.
A drier, more stable pattern is expected for Wednesday and
Thursday, before more precipitation chances enter late in the week
with cooler temperatures.
&&
.DISCUSSION...
The cold front is beginning to make its way east of the Cascades.
Latest radar imagery at around 8:30 PM PDT this evening is
starting to show some enhanced echos developing over the Moses
Lake Area and Upper Columbia Basin. The leading edge of the front is
slightly further to the northwest, stretching from around Oroville
to Lincoln City in northeast Oregon. Out ahead of the front,
further east over the basin and into the ID Panhandle, very light
rain has been falling due to some weak isentropic accent. These
showers have generally yielded a few hundredths of an inch of
rainfall, except in the mountains where orographic have produced
slightly higher amounts up to around a tenth or more in the last
five hours or so. Expect rainfall to pick up in intensity a bit as
the cold front produces stronger lift as it moves east across the
region tonight.
Increased precipitation chances a bit and rainfall amounts,
especially in the basin where around a tenth of an inch from the
frontal band is expected. The HRRR model seems to have a better
handle on this frontal band with it moving through the Palouse,
Spokane Area and Northeast Mountains between 10:00 PM and 2:00 AM
tonight. Some lingering showers will pop up behind the front as low
to mid levels of the atmosphere become slightly more unstable with
the upper level shortwave moving through. However, the upper level
wave is fairly weak and the atmosphere will dry out from the top
down; so, I don`t expect a lot of shower activity once the front
pushes east and rain may just transition to a little drizzle
instead. Showers will continue to be more likely in the Panhandle
mountains due to terrain effects. Rainfall amounts will be highest
in the ID Panhandle where a quarter of an inch of rain or more is
expected between midnight tonight and tomorrow morning. These
amounts shouldn`t be much of a concern and probably will be well
received due to our extended stretch dry weather since late July
through early October. /SVH
&&
.AVIATION...
06Z TAFS: Light to moderate rainfall will continue to fill in over
the region southeast of a line from Wenatchee to Republic as a cold
front moves southeast across the region. Expect cigs to lower into
MVFR/IFR category with rain transitioning over to some light drizzle
with low stratus through the morning hours over extreme eastern WA.
Showers will continue in the ID Panhandle through tomorrow
afternoon. A stronger and wetter storm system will begin to move in
early Monday evening. This storm will feature a very moist air mass
ahead of a strong cold front. This will bring moderate to heavy rain
with reduced visibilities likely under heavier rain bands. Strong
westerly winds will likely mix down to the surface with cold front
passage Sunday night as well. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 53 64 50 57 36 55 / 100 40 100 50 10 0
Coeur d`Alene 52 61 49 54 34 53 / 100 90 100 70 10 10
Pullman 51 66 50 55 34 54 / 100 70 90 80 10 0
Lewiston 55 72 56 60 40 59 / 70 60 80 60 10 0
Colville 50 63 49 57 29 56 / 90 40 100 30 10 10
Sandpoint 50 58 50 52 32 51 / 100 100 100 70 10 10
Kellogg 49 58 50 50 33 49 / 100 100 100 100 20 10
Moses Lake 52 71 51 64 36 59 / 70 30 30 10 0 0
Wenatchee 52 68 51 61 38 58 / 40 20 50 10 0 0
Omak 47 66 47 60 34 59 / 50 20 60 10 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1243 PM CDT MON OCT 15 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
227 AM CDT MON OCT 15 2012
MAIN FORECAST CONCERN IS THE IMPACTS ON THE AREA FROM A DEEP UPPER
TROUGH DROPPING INTO THE NORTHERN PLAINS TUESDAY NIGHT.
CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT
ANALYSIS SHOWED NEARLY ZONAL FLOW ACROSS THE NORTHERN ROCKIES AND
SOUTHWEST CANADA...AND TROUGHING ACROSS THE WESTERN GREAT LAKES
REGION INTO ILLINOIS. THE FORECAST AREA LIES ON THE WESTERN SIDE
OF THIS TROUGHING...FAVORING SUBSIDENCE AND DRY AIR. 00Z SOUNDINGS
FROM ABR AND MPX REFLECT THESE ATTRIBUTES...WITH PRECIPITABLE
WATER VALUES NEAR 0.5 INCH. SATELLITE IMAGERY ALSO REFLECTS THE
DRY AIR WITH CLEARING ACROSS MUCH OF MINNESOTA AND IOWA. SOME
COOLER AIR TOO FLOWING IN ON THE BACK SIDE OF THE TROUGH WITH
850MB TEMPS OF 3C AT MPX AT 00Z. HOWEVER...WARMER READINGS OF
7-15C AT 850MB WERE OBSERVED IN THE DAKOTAS. AT THE SURFACE...A
RIDGE OF HIGH PRESSURE WAS PRESENT ACROSS WESTERN MINNESOTA WHILE
A NEW LOW PRESSURE SYSTEM WAS TAKING SHAPE ACROSS SOUTHERN
SASKATCHEWAN.
TODAY AND TONIGHT...FOCUS IS ON A COLLECTION OF SHORTWAVES IN THE
ZONAL FLOW OVER WASHINGTON. MODELS ARE IN GOOD AGREEMENT SENDING
THESE EAST INTO THE EASTERN DAKOTAS AND WESTERN MINNESOTA BY 12Z
TUESDAY. THERE EVEN APPEARS TO BE A WEAK TROUGH SIGNATURE IN THE
500MB HEIGHT FIELD AT 12Z WITH THESE SHORTWAVES. AS THESE SHORTWAVES
HEAD EAST...THEY WILL HELP PICK UP THE CURRENT SYSTEM IN SOUTH
CENTRAL SASKATCHEWAN...SENDING A TROUGH INTO MINNESOTA BY 12Z
TUESDAY. WARM ADVECTION AHEAD OF THIS SYSTEM WILL COMMENCE OVER THE
FORECAST AREA THIS AFTERNOON...WITH 850MB TEMPS TOPPING OUT BETWEEN
4-8C BY 00Z...WARMEST WEST. OTHER THAN SOME INCREASE IN WARM
ADVECTION HIGH AND PERHAPS MID CLOUDS AS WELL LATE IN THE DAY...
CURRENTLY OBSERVED CROSSING THE DAKOTAS...SHOULD SEE PLENTY OF SUN.
AS A RESULT...ANTICIPATING TEMPERATURES TO TOP OUT IN THE MID 50S TO
MID 60S. FOR TONIGHT...PLANNING ON THE MID AND HIGH CLOUDS TO
QUICKLY ENCOMPASS THE AREA...HELPING TO LIMIT TEMPERATURE FALL. IN
ADDITION...MODELS SHOW AN INCREASE OF 850MB MOISTURE TRANSPORT
THROUGH THE NIGHT AHEAD OF THE TROUGH COMING INTO MINNESOTA. NOSE OF
THIS MOISTURE TRANSPORT...AS WELL AS THE BULK OF ISENTROPIC LIFT...
APPEARS TO BE SITUATED MAINLY NORTH OF THE AREA. AS SUCH...EXPECTING
MOST PRECIPITATION TO STAY NORTH. HOWEVER...DID INTRODUCE A 20
PERCENT CHANCE IN TAYLOR COUNTY SINCE THEY LOOK TO BE RIGHT ON THE
EDGE OF WHERE THE WARM ADVECTION PRECIPITATION MAY EXIST. FOLLOWED A
BLEND OF GUIDANCE FOR LOWS.
TUESDAY...THE WEAK UPPER TROUGH SIGNATURE PRESENT OVER THE
EASTERN DAKOTAS AT 12Z TUESDAY IS FORECAST BY ALL MODELS TO CROSS
THE AREA ON TUESDAY. THE SAME QUESTIONS REMAIN IF THIS TROUGH CAN
PRODUCE PRECIPITATION AS IT MOVES THROUGH. THE 14.12Z ECMWF WAS MUCH
MORE IMPRESSIVE WITH QPF COMPARED TO ITS PREVIOUS RUN WITH MUCH OF
THE AREA AFFECTED. MEANWHILE THE 15.00Z NAM CONTINUES TO PAINT A
MOSTLY DRY SCENARIO OUTSIDE OF SOME LINGERING WARM ADVECTION PRECIP
OVER TAYLOR COUNTY IN THE MORNING. THE 15.00Z GFS LIES IN-BETWEEN
THE TWO SCENARIOS WITH QPF MAINLY IN THE MORNING ALONG AND NORTHEAST
OF I-94. THINKING THE ECMWF IS OVERDONE WITH THE AMOUNT OF QPF GIVEN
THE OVERALL LACK OF MOISTURE AVAILABILITY...ESPECIALLY IN THE LOWER
LEVELS. THEREFORE...HAVE STAYED CLOSE TO THE PREVIOUS FORECAST OF
20-30 PERCENT CHANCES ALONG AND NORTHEAST OF I-94. NEW 15.00Z ECMWF
HAS A LITTLE LESS QPF...AND FOCUSES ITS MAIN AREA SIMILAR TO WHERE
THE FORECAST HAS IT. TEMPERATURES ARE A BIT TRICKY ON TUESDAY AS
MUCH OF THE MORNING WILL LIKELY BE CLOUDY WITH MID AND HIGH CLOUDS
AROUND. AS THE TROUGH COMES THROUGH...THE OPPORTUNITY FOR CLEARING
EXISTS. 850MB TEMPS REALLY DO NOT COOL WITH THE TROUGH...HOVERING
BETWEEN 9C NORTH AND 13C SOUTH. HERE TOO WILL STAY PRETTY CLOSE TO
THE PREVIOUS FORECAST WITH HIGHS FROM THE MID 60S EAST (MOST CLOUDS)
TO LOW 70S WEST.
TUESDAY NIGHT...A VERY POTENT UPPER TROUGH IS PROGGED TO DIG DOWN
INTO MONTANA AND THE NORTHERN PLAINS BY 12Z WEDNESDAY. AS THIS
TROUGH DIGS IN...A COLD FRONT GETS SENT EASTWARD...PERHAPS REACHING
WESTERN PORTIONS OF THE FORECAST AREA BY 12Z WEDNESDAY. THE 15.00Z
GFS AND NAM...AS WELL AS THE 14.12Z/15.00Z ECMWF KEEP PRECIPITATION
NORTHWEST OF THE AREA THROUGH TUESDAY NIGHT. THIS SEEMS REASONABLE
GIVEN THAT THE BULK OF THE PRECIPITATION LOOKS TO OCCUR POST-FRONTAL
AND MORE ASSOCIATED WITH DPVA FROM THE POTENT TROUGH. AS SUCH...HAVE
REMOVED ANY LOW CHANCES OF PRECIPITATION IN FAR WESTERN PORTIONS OF
THE AREA. TEMPERATURES COULD DROP QUICKLY IN THE EVENING...
ESPECIALLY AT THE TYPICAL COLD SPOTS...WITH MOSTLY CLEAR SKIES AND A
BAGGY PRESSURE GRADIENT IN PLACE. INCREASING MID AND HIGH CLOUDS AS
WELL AS WINDS AHEAD OF THE FRONT AND UPPER TROUGH SHOULD HELP TO
HOLD TEMPERATURES STEADY OR EVEN RISE AFTER MIDNIGHT.
WEDNESDAY AND WEDNESDAY NIGHT...MODELS ARE IN REALLY GOOD AGREEMENT
THAT THE POTENT UPPER TROUGH WILL CONTINUE TO DIG SOUTHEASTWARD...
FULLY ENCOMPASSING THE AREA BY WEDNESDAY NIGHT. HOWEVER...THERE ARE
SOME IMPORTANT DETAILS WITHIN THE UPPER TROUGH THAT MODELS DIFFER
ON. THE FIRST IS WITH A SHORTWAVE EXTENDING SOUTH OF AN UPPER LOW
CONTAINED WITHIN THE TROUGH. THIS SHORTWAVE...PROGGED NEAR BISMARCK
NORTH DAKOTA AT 12Z WEDNESDAY...THE 15.00Z GFS IS MUCH FASTER THAN
ANY OTHER MODEL WITH IT BY BRINGING IT INTO THE FORECAST AREA BY
00Z. THE 15.00Z NAM/UKMET/CANADIAN/ECMWF ARE ALL SLOWER...ONLY
REACHING WESTERN MINNESOTA BY 00Z. THIS IS A SIGNIFICANT ISSUE AS
THE FASTER GFS WOULD NOT ALLOW AS MUCH MOISTURE RETURN FROM THE GULF
OF MEXICO TO COME UP INTO THE FORECAST AREA. THUS...THE GFS ENDS UP
AS A DRY SOLUTION. ALL THE OTHER MODELS PRODUCE PRECIPITATION ON
WEDNESDAY WHICH SEEMS REASONABLE. THUS...THE 60 PERCENT CHANCES ARE
STILL ON TRACK. WEDNESDAY NIGHT IS A LITTLE MORE UP IN THE AIR...
THOUGH. THINGS IN PLAY WITH PRECIPITATION CHANCES INCLUDE: TRACK OF
THE UPPER LOW WITHIN THE TROUGH...A POSSIBLE DRY SLOT...AND A TROWAL
AND COLD CONVEYOR BELT AREA WRAPPING AROUND THE UPPER LOW. THE
PMDHMD FROM HPC DISCUSSES THIS SITUATION WELL...WITH MODELS ALL OVER
THE PLACE WITH THESE FEATURES AND ALL PLAUSIBLE. THEREFORE...PLAN ON
TAKING A CONSENSUS APPROACH. AS THE PMDHMD STATES TOO...THE SYSTEM
RESPONSIBLE FOR THE POTENT UPPER TROUGH IS IN A DATA SPARSE REGION
OF THE NORTHERN/NORTHEAST PACIFIC. SO IT MAY TAKE AWHILE BEFORE
MODELS SETTLE DOWN ON A SOLUTION WITH THE VARIOUS FEATURES. THE
CONSENSUS APPROACH RESULTS IN 30 TO 50 PERCENT CHANCES...HIGHEST
ACROSS THE NORTH. ALSO FOLLOWED THE CONSENSUS APPROACH FOR
TEMPERATURES. SHOULD STILL BE NEAR NORMAL ON WEDNESDAY WITH THE WARM
ADVECTION AHEAD OF A SURFACE COLD FRONTAL PASSAGE. HOWEVER...
TEMPERATURES LOOK TO FALL IN THE AFTERNOON AS THE FRONT PASSES AND
RAIN DEVELOPS. IF A DEEP DRY SLOT ENTERS THE PICTURE WEDNESDAY
NIGHT...LOWS COULD BOTTOM OUT IN 30S. HOWEVER...WILL PLAY MORE
CLOUDS AND WIND TO KEEP LOWS IN THE 40S.
.LONG TERM...THURSDAY THROUGH SUNDAY NIGHT
227 AM CDT MON OCT 15 2012
15.00Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES ARE IN FAIRLY GOOD
AGREEMENT ON HANDLING THE UPPER TROUGH AND ITS LIFT OUT NORTHEAST
AWAY FROM THE AREA. THE GFS AGAIN IS SLIGHTLY FAST...BUT ALL MODELS
AGREE THAT BY FRIDAY NIGHT...THE UPPER TROUGH WILL BE FAR ENOUGH
EAST OF THE AREA TO ALLOW CONDITIONS TO DRY OUT. UNTIL THEN...SAME
CONCERNS THAT WERE PRESENT ON WEDNESDAY NIGHT WITH POSITIONS OF THE
UPPER LOW IN THE TROUGH...DRY SLOT...TROWAL AND COLD CONVEYOR BELT
STILL PERSIST THROUGH FRIDAY. AS A RESULT...HAVE CONTINUED TO FOLLOW
A CONSENSUS APPROACH. HIGHEST CHANCES OF PRECIPITATION EXPECTED ON
THURSDAY SINCE THERE ARE INDICATIONS THAT THE TROUGH WILL FILL AFTER
THEN. COOL CONDITIONS ARE LIKELY TOO WITH THE UPPER TROUGH IN PLACE.
850MB TEMPS ARE ONLY PROGGED IN THE 0-2C RANGE. COMBINE THIS WITH
PRECIPITATION COULD END UP KEEPING HIGHS IN SOME LOCATIONS FROM EVEN
REACHING 50...ESPECIALLY ON THURSDAY.
FOR THE WEEKEND...MODELS ARE INDICATING THAT A POTENT UPPER TROUGH
WILL DROP SOUTH OUT OF THE GULF OF ALASKA AND AT LEAST INTO BRITISH
COLUMBIA. THE 14.12Z AND 15.00Z ECMWF RUNS AS WELL AS SOME OF THE
GFS ENSEMBLES TAKE IT ONE STEP FURTHER AND DIG THE TROUGH INTO THE
PACIFIC NORTHWEST. ALL SOLUTIONS THUS WOULD YIELD AT LEAST ZONAL
FLOW DOWNSTREAM INTO THE FORECAST AREA...RESULTING IN WARMING AND
DRY CONDITIONS. IN THE CASE OF THE ECMWF...RIDGING ENDS UP BUILDING
INTO THE FORECAST AREA. FOR NOW HAVE FOLLOWED THE CONSENSUS APPROACH
FOR TEMPERATURES GIVEN THE SPREAD IN HOW THE UPPER FLOW EVOLVES...
BUT SHOULD THE ECMWF VERIFY...TEMPERATURES MAY NEED TO BE INCREASED.
BY 18Z SUNDAY...THE ECMWF SUGGESTS 850MB TEMPS OF 10-14C...COMPARED
TO 4-8C FROM THE GFS.
&&
.AVIATION...THROUGH 18Z TUESDAY
1243 PM CDT MON OCT 15 2012
A WARM FRONT WILL MOVE SLOWLY EAST ACROSS THE AREA TONIGHT. HIGH
CLOUDS...MAINLY ABOVE 20K FEET...WILL ADVANCE INTO THE AREA THIS
AFTERNOON. THESE CLOUDS WILL LOWER TO AROUND 10K FEET BETWEEN
16.00Z AND 16.03Z...AND REMAIN THERE THROUGH TUESDAY MORNING.
THE LIGHT WINDS WILL SHIFT TO SOUTH AND CLIMB INTO THE 10 TO
15 KNOT RANGE THIS EVENING...AND CHANGE LITTLE FOR THE REMAINDER
OF THIS PERIOD.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
227 AM CDT MON OCT 15 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BOYNE
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1224 PM CDT MON OCT 15 2012
.UPDATE...A FEW CHANGES MADE TO THE TODAY FORECAST PERIOD. SFC HIGH
PRESSURE IN THE LOWER MISSISSIPPI VALLEY WILL STEADILY BUILD INTO
SOUTHERN WISCONSIN FROM THE SOUTH AS YESTERDAYS LOW PRESSURE SYSTEM
EXITS EAST. THE MAIN CONCERN...AND WHERE THE GREATEST CHANGES WERE
MADE...HAD TO DO WITH SKY GRIDS. A LOW-LEVEL CLOUD DECK...WITH CIGS
21 HFT TO 25 HFT...IS POSITIONED OVER THE FAR EASTERN SECTION OF THE
CWA AND DID NOT DISSIPATE/CLEAR OUT TO THE EAST AS PREVIOUSLY
THOUGHT THIS MORNING. VIS SAT TRENDS SHOW SOME SLIGHT MOVEMENT OF
THE DECK EAST...BUT IT IS NOT QUICK TO DO SO. IN ADDITION...THERE IS
SOME BREAKS ON THE FAR WESTERN EDGE OF IT. BUFKIT SOUNDINGS SHOW
THIS LOW-LEVEL MOISTURE REALLY WELL...IF NOT MAYBE OVER DONE IN
REGARD TO HOW LONG IT KEEPS IT IN. FURTHER...THE CLOUD DECK
CORRESPONDS WELL WITH RAP 925-850 MEAN RH FIELD.
GIVEN BUFKIT SOUNDINGS...MODEL RH...AND SAT TRENDS...EXPECT CLOUDS
TO DIMINISH GRADUALLY AND MOVE EAST OVER COURSE OF THE DAY. CLOUDS
SHOULD PERSIST INTO THE AFTERNOON IN THE FAR EAST. GIVEN CHANGES IN
SKY COVER...ALSO LOWERED HIGH TEMPERATURES WHERE THE DECK RESIDES
BY A FEW DEGREES.
.AVIATION/18Z TAFS/...AREA OF MVFR/VFR CEILINGS WITH CLOUD DECK
SHOULD LINGER THROUGH THE AFTERNOON AT THE EASTERN TAF SITES. THESE
CLOUDS SHOULD SLOWLY THIN OUT LATER THIS AFTERNOON OR EARLY THIS
EVENING...WITH THE LOSS OF BOTH DAYTIME HEATING AND THE MOIST LAYER
IN THE LOW LEVELS. NORTHWEST WINDS AROUND 10 KNOTS ARE EXPECTED
THROUGH 00Z TUESDAY.
VFR CONDITIONS ARE THEN EXPECTED TONIGHT AND TUESDAY. BROKEN TO
OVERCAST MIDDLE TO HIGH CLOUDS WILL MOVE SOUTHEAST INTO THE AREA
LATER THIS EVENING AND AFTER MIDNIGHT...AND LINGER THROUGH TUESDAY.
ANY LIGHT RAIN SHOWERS OR DRIZZLE SHOULD REMAIN NORTH OF TAF SITES.
WINDS WILL GRADUALLY INCREASE OUT OF THE SOUTH TONIGHT INTO
TUESDAY...WITH GUSTS OF 20 TO 25 KNOTS POSSIBLE TUESDAY AFTERNOON.
&&
.MARINE...WILL LET SMALL CRAFT ADVISORY EXPIRE AT 18Z ACROSS THE
NEARSHORE WATERS. CURRENT OBSERVATIONS ALONG AND NEAR THE SHORE ARE
ONLY GUSTING TO AROUND 15 KNOTS. THE MID LAKE BUOY STILL HAS SOME
GUSTS TO 25 KNOTS OCCURRING...WHICH MAY STILL BE OCCURRING TOWARD
THE OPEN WATERS. HOWEVER...WINDS SHOULD CONTINUE TO WEAKEN...AS
PRESSURE GRADIENT WEAKENS. AREA WEB CAMERAS SHOWING WAVES NON
EXISTENT NEAR THE SHORE...TO BE EXPECTED GIVEN THE OFFSHORE WINDS. 6
FOOT WAVES AT THE MID LAKE BUOY SUGGEST WAVES TOWARD THE OPEN WATERS
SHOULD BE IN THE 2 TO 4 FOOT RANGE.
.PREV DISCUSSION... /ISSUED 333 AM CDT MON OCT 15 2012/
SHORT TERM...
TODAY AND TONIGHT...FORECAST CONFIDENCE IS HIGH.
CLOUDS THE FIRST ISSUE AS THEY SLOWLY CLEAR FROM WEST TO EAST
ACROSS THE REMAINDER OF CWA WITH DEPARTING CYCLONIC FLOW AROUND
MID-UPPER LEVEL LOW...WHICH WAS NEAR SSM AT 06Z ON WATER VAPOR
LOOPS...AS IT LIFTS AWAY TO THE NORTHEAST.
CURRENT LOW LEVEL CLOUD DECK CLOSELY TIED TO 925-850 MB LAYER
RELATIVE HUMIDITY OF 80 PCT OR HIGHER...WHICH PUSHES EAST OF CWA
AT/AROUND 12Z TODAY. WILL KEEP AT LEAST PARTLY CLOUDY IN REGIONS ON
THE CYCLONIC SIDE OF 500 MB SHEARED VORTICITY AXIS UNTIL IT CLEARS
FORECAST AREA AROUND OR SHORTLY AFTER 18Z. MIXING UP TO 925 MB
TEMPERATURES THAT CLIMB TO AROUND +7C NORTHEAST TO +9C SOUTHWEST BY
00Z BRINGING MID 50S NORTHEAST...UPPER 50S MOST LOCATIONS...AND
AROUND 60 SOUTHWEST...WHICH IS IN GOOD AGREEMENT WITH CONSENSUS MOS
AND RAW TEMPERATURES.
MAINLY CLEAR SKIES AS WEAK RIDGING BUILDS IN FOR THE REST OF THE
AFTERNOON AND EVENING AHEAD OF THE NEXT SHORT WAVE TROUGH...WHICH
MOVES OUT INTO THE NORTHERN PLAINS THIS EVENING. THE MODELS HAVE
THE TROUGH AXIS REACHING A CONSENSUS POSITION FROM NORTHERN MINNESOTA
TO EASTERN NEBRASKA BY 12Z TUESDAY.
700-850MB WARM AIR ADVECTION BRINGS A MID-DECK BACK ACROSS THE
FORECAST AREA BETWEEN 06Z AND 12Z TUESDAY...BUT PRECIPITATION WILL
REMAIN NORTH OF CWA WITH BEST ISENTROPIC ADIABATIC OMEGA AND
FRONTOGENETIC FORCING ACROSS NORTHERN WISCONSIN. CLOUDS WILL HALT
TEMP FALL WITH LOWS BEING REACHED BETWEEN 06Z AND 09Z TUESDAY.
TUESDAY...FORECAST CONFIDENCE HIGH.
EXPECTING MILD AND CLOUDY CONDITIONS WITH BREEZY SOUTH WINDS. TEMPS
WARMING INTO THE LOWER/MID 60S IS CONSERVATIVE DUE TO THE EXPECTED
CLOUD COVER. STRAIGHT 925MB TEMPS WITH DRY ADIABATIC MIXING WOULD
SUGGEST MAX TEMPS IN THE LOWER 70. THERE COULD BE SOME WEAK
VORTICITY ADVECTION DUE TO A SHORTWAVE MOVING ACROSS...SO KEPT SMALL
POPS IN NORTHEAST FORECAST AREA. AMOUNTS SHOULD BE LIGHT OR NONE AT
ALL.
PRECIP CHANCES MOVE EAST OUT OF THE AREA TUE NIGHT WITH THE EXITING
SHORTWAVE. MID CLOUDS AND WARM AIR ADVECTION AHEAD OF THE NEXT UPPER
TROUGH WILL KEEP TEMPS MILD OVERNIGHT...WITH LOWS EXPECTED IN THE
UPPER 40S/LOWER 50S.
WEDNESDAY THROUGH THURSDAY...FORECAST CONFIDENCE MEDIUM TO HIGH.
AN UPPER LEVEL TROUGH WILL AMPLIFY AS A 120 KT JET STREAMS INTO THE
PLAINS FROM THE PACIFIC NORTHWEST ON WED. THE 500MB TROUGH WILL
DEVELOP INTO A CLOSED UPPER LOW AND MEANDER ACROSS MN AND WI THROUGH
THU NIGHT. THIS WILL BRING A ROUND OF MODERATE RAIN TO SOUTHERN WI
WITH THE LEADING COLD FRONT. GFS APPEARS TOO FAST WITH THE
FRONT...SO DISREGARDED ITS SOLUTION. ECMWF AND UKMET ARE THE SLOWEST
WITH THE NAM AND CANADIAN ARE SOMEWHERE IN BETWEEN. GENERALLY
COMPROMISED AND WENT WITH LIKELY POPS IN THE WESTERN FORECAST AREA
WED AFTERNOON THEN LIKELY IN THE EASTERN AREA WED EVENING.
IF THE SLOWER SOLUTION PANS OUT WITH PRECIP NOT SPREADING INTO
FORECAST AREA UNTIL WED EVE...THEN MAX TEMPS WILL BE HIGHER THAN
WHAT I HAVE IN THERE. WAS COUNTING ON CLOUDS AND PRECIP TO KEEP THE
TEMPS DOWN.
SOME MODELS DRY SLOT SOUTHERN WI ON THU AS THE LOW OCCLUDES WHILE
OTHERS HAVE US IN A BULLSEYE OF PRECIP. WENT WITH MODEL CONSENSUS OF
CHANCE POPS FOR NOW. AS HPC STATES...WE WILL HAVE TO WAIT UNTIL TUE
WHEN THIS UPPER TROUGH/JET REACH THE CONTINENTAL NORTHWEST AND
MODELS CAN RESOLVE THE DATA BETTER.
LONG TERM...
SATURDAY THROUGH SUNDAY...FORECAST CONFIDENCE MEDIUM TO LOW.
DISREGARDING PRECIP CHANCES IN THE GFS MODEL SOLUTION ON SAT AS AIR
SHOULD BE TOO DRY DESPITE THE WARM AIR ADVECTION AND SHORTWAVE
MOVING ACROSS THE REGION. THE ECMWF IS NOW QUICKER WITH MOVING THAT
UPPER LOW OUT EAST...CLOSER TO THE GFS SOLUTION. THIS MEANS DRY
WEATHER ON SATURDAY.
MAJOR UPPER LEVEL MODEL DIFFERENCES FOR LATER IN THE WEEKEND AS THE
GFS GOES ZONAL AND THE ECMWF DEVELOPS ANOTHER BIG TROUGH. GFS
SUGGESTS COOL RAIN AND ECMWF SUGGESTS DRY AND WARM RIDGING.
AVIATION/12Z TAFS/...
REMAINING MVFR CLOUD DECK SHOULD BE OUT OF EASTERN TAF SITES BY
12Z...WITH A MID-DECK LINGERING UNTIL AT LEAST MID MORNING WHEN
CYCLONIC FLOW SHOULD BE LIFTING AWAY FROM FORECAST AREA. VFR
CONDITIONS FOR THE REMAINDER OF THE FORECAST...WITH WARM AIR
ADVECTION CLOUDS AT OR ABOVE 8K FT OVERSPREADING THE REGION FROM
WEST TO EAST BETWEEN 06Z AND 09Z TUESDAY.
MARINE...
WILL LEAVE SMALL CRAFT ADVISORY END TIME AS IS...WITH SOUNDINGS
SHOWING POTENTIAL FOR FREQUENT GUSTS OVER THE WATER UNTIL AT LEAST
15Z. NEXT SHIFT MAY BE ABLE TO DROP EARLY IF GRADIENT SLACKENS
SOONER THAN EXPECTED WITH SURFACE RIDGE BUILDING IN. TIGHTENING
GRADIENT AHEAD OF NEXT LOW PRESSURE AREA MOVING TOWARD THE WESTERN
GREAT LAKES MAY REQUIRE ANOTHER ADVISORY FOR TUESDAY AFTERNOON AND
EVENING FOR GUSTY SOUTH TO SOUTHWEST WINDS. GFS WINDS STRONGER THAN
NAM...ECMWF OR GEM BUT ALL SHOW THE POTENTIAL FOR ADVISORY LEVEL
WINDS. WILL MENTION POSSIBLE NEED FOR A SMALL CRAFT AND LET NEXT
SHIFT ASSESS NEXT MODEL RUNS FOR TIMING.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR
LMZ643>646.
&&
$$
UPDATE...WOOD/ET
TODAY/TONIGHT AND AVIATION/MARINE...REM
TUESDAY THROUGH SUNDAY...MRC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
556 AM CDT MON OCT 15 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
227 AM CDT MON OCT 15 2012
MAIN FORECAST CONCERN IS THE IMPACTS ON THE AREA FROM A DEEP UPPER
TROUGH DROPPING INTO THE NORTHERN PLAINS TUESDAY NIGHT.
CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT
ANALYSIS SHOWED NEARLY ZONAL FLOW ACROSS THE NORTHERN ROCKIES AND
SOUTHWEST CANADA...AND TROUGHING ACROSS THE WESTERN GREAT LAKES
REGION INTO ILLINOIS. THE FORECAST AREA LIES ON THE WESTERN SIDE
OF THIS TROUGHING...FAVORING SUBSIDENCE AND DRY AIR. 00Z SOUNDINGS
FROM ABR AND MPX REFLECT THESE ATTRIBUTES...WITH PRECIPITABLE
WATER VALUES NEAR 0.5 INCH. SATELLITE IMAGERY ALSO REFLECTS THE
DRY AIR WITH CLEARING ACROSS MUCH OF MINNESOTA AND IOWA. SOME
COOLER AIR TOO FLOWING IN ON THE BACK SIDE OF THE TROUGH WITH
850MB TEMPS OF 3C AT MPX AT 00Z. HOWEVER...WARMER READINGS OF
7-15C AT 850MB WERE OBSERVED IN THE DAKOTAS. AT THE SURFACE...A
RIDGE OF HIGH PRESSURE WAS PRESENT ACROSS WESTERN MINNESOTA WHILE
A NEW LOW PRESSURE SYSTEM WAS TAKING SHAPE ACROSS SOUTHERN
SASKATCHEWAN.
TODAY AND TONIGHT...FOCUS IS ON A COLLECTION OF SHORTWAVES IN THE
ZONAL FLOW OVER WASHINGTON. MODELS ARE IN GOOD AGREEMENT SENDING
THESE EAST INTO THE EASTERN DAKOTAS AND WESTERN MINNESOTA BY 12Z
TUESDAY. THERE EVEN APPEARS TO BE A WEAK TROUGH SIGNATURE IN THE
500MB HEIGHT FIELD AT 12Z WITH THESE SHORTWAVES. AS THESE SHORTWAVES
HEAD EAST...THEY WILL HELP PICK UP THE CURRENT SYSTEM IN SOUTH
CENTRAL SASKATCHEWAN...SENDING A TROUGH INTO MINNESOTA BY 12Z
TUESDAY. WARM ADVECTION AHEAD OF THIS SYSTEM WILL COMMENCE OVER THE
FORECAST AREA THIS AFTERNOON...WITH 850MB TEMPS TOPPING OUT BETWEEN
4-8C BY 00Z...WARMEST WEST. OTHER THAN SOME INCREASE IN WARM
ADVECTION HIGH AND PERHAPS MID CLOUDS AS WELL LATE IN THE DAY...
CURRENTLY OBSERVED CROSSING THE DAKOTAS...SHOULD SEE PLENTY OF SUN.
AS A RESULT...ANTICIPATING TEMPERATURES TO TOP OUT IN THE MID 50S TO
MID 60S. FOR TONIGHT...PLANNING ON THE MID AND HIGH CLOUDS TO
QUICKLY ENCOMPASS THE AREA...HELPING TO LIMIT TEMPERATURE FALL. IN
ADDITION...MODELS SHOW AN INCREASE OF 850MB MOISTURE TRANSPORT
THROUGH THE NIGHT AHEAD OF THE TROUGH COMING INTO MINNESOTA. NOSE OF
THIS MOISTURE TRANSPORT...AS WELL AS THE BULK OF ISENTROPIC LIFT...
APPEARS TO BE SITUATED MAINLY NORTH OF THE AREA. AS SUCH...EXPECTING
MOST PRECIPITATION TO STAY NORTH. HOWEVER...DID INTRODUCE A 20
PERCENT CHANCE IN TAYLOR COUNTY SINCE THEY LOOK TO BE RIGHT ON THE
EDGE OF WHERE THE WARM ADVECTION PRECIPITATION MAY EXIST. FOLLOWED A
BLEND OF GUIDANCE FOR LOWS.
TUESDAY...THE WEAK UPPER TROUGH SIGNATURE PRESENT OVER THE
EASTERN DAKOTAS AT 12Z TUESDAY IS FORECAST BY ALL MODELS TO CROSS
THE AREA ON TUESDAY. THE SAME QUESTIONS REMAIN IF THIS TROUGH CAN
PRODUCE PRECIPITATION AS IT MOVES THROUGH. THE 14.12Z ECMWF WAS MUCH
MORE IMPRESSIVE WITH QPF COMPARED TO ITS PREVIOUS RUN WITH MUCH OF
THE AREA AFFECTED. MEANWHILE THE 15.00Z NAM CONTINUES TO PAINT A
MOSTLY DRY SCENARIO OUTSIDE OF SOME LINGERING WARM ADVECTION PRECIP
OVER TAYLOR COUNTY IN THE MORNING. THE 15.00Z GFS LIES IN-BETWEEN
THE TWO SCENARIOS WITH QPF MAINLY IN THE MORNING ALONG AND NORTHEAST
OF I-94. THINKING THE ECMWF IS OVERDONE WITH THE AMOUNT OF QPF GIVEN
THE OVERALL LACK OF MOISTURE AVAILABILITY...ESPECIALLY IN THE LOWER
LEVELS. THEREFORE...HAVE STAYED CLOSE TO THE PREVIOUS FORECAST OF
20-30 PERCENT CHANCES ALONG AND NORTHEAST OF I-94. NEW 15.00Z ECMWF
HAS A LITTLE LESS QPF...AND FOCUSES ITS MAIN AREA SIMILAR TO WHERE
THE FORECAST HAS IT. TEMPERATURES ARE A BIT TRICKY ON TUESDAY AS
MUCH OF THE MORNING WILL LIKELY BE CLOUDY WITH MID AND HIGH CLOUDS
AROUND. AS THE TROUGH COMES THROUGH...THE OPPORTUNITY FOR CLEARING
EXISTS. 850MB TEMPS REALLY DO NOT COOL WITH THE TROUGH...HOVERING
BETWEEN 9C NORTH AND 13C SOUTH. HERE TOO WILL STAY PRETTY CLOSE TO
THE PREVIOUS FORECAST WITH HIGHS FROM THE MID 60S EAST (MOST CLOUDS)
TO LOW 70S WEST.
TUESDAY NIGHT...A VERY POTENT UPPER TROUGH IS PROGGED TO DIG DOWN
INTO MONTANA AND THE NORTHERN PLAINS BY 12Z WEDNESDAY. AS THIS
TROUGH DIGS IN...A COLD FRONT GETS SENT EASTWARD...PERHAPS REACHING
WESTERN PORTIONS OF THE FORECAST AREA BY 12Z WEDNESDAY. THE 15.00Z
GFS AND NAM...AS WELL AS THE 14.12Z/15.00Z ECMWF KEEP PRECIPITATION
NORTHWEST OF THE AREA THROUGH TUESDAY NIGHT. THIS SEEMS REASONABLE
GIVEN THAT THE BULK OF THE PRECIPITATION LOOKS TO OCCUR POST-FRONTAL
AND MORE ASSOCIATED WITH DPVA FROM THE POTENT TROUGH. AS SUCH...HAVE
REMOVED ANY LOW CHANCES OF PRECIPITATION IN FAR WESTERN PORTIONS OF
THE AREA. TEMPERATURES COULD DROP QUICKLY IN THE EVENING...
ESPECIALLY AT THE TYPICAL COLD SPOTS...WITH MOSTLY CLEAR SKIES AND A
BAGGY PRESSURE GRADIENT IN PLACE. INCREASING MID AND HIGH CLOUDS AS
WELL AS WINDS AHEAD OF THE FRONT AND UPPER TROUGH SHOULD HELP TO
HOLD TEMPERATURES STEADY OR EVEN RISE AFTER MIDNIGHT.
WEDNESDAY AND WEDNESDAY NIGHT...MODELS ARE IN REALLY GOOD AGREEMENT
THAT THE POTENT UPPER TROUGH WILL CONTINUE TO DIG SOUTHEASTWARD...
FULLY ENCOMPASSING THE AREA BY WEDNESDAY NIGHT. HOWEVER...THERE ARE
SOME IMPORTANT DETAILS WITHIN THE UPPER TROUGH THAT MODELS DIFFER
ON. THE FIRST IS WITH A SHORTWAVE EXTENDING SOUTH OF AN UPPER LOW
CONTAINED WITHIN THE TROUGH. THIS SHORTWAVE...PROGGED NEAR BISMARCK
NORTH DAKOTA AT 12Z WEDNESDAY...THE 15.00Z GFS IS MUCH FASTER THAN
ANY OTHER MODEL WITH IT BY BRINGING IT INTO THE FORECAST AREA BY
00Z. THE 15.00Z NAM/UKMET/CANADIAN/ECMWF ARE ALL SLOWER...ONLY
REACHING WESTERN MINNESOTA BY 00Z. THIS IS A SIGNIFICANT ISSUE AS
THE FASTER GFS WOULD NOT ALLOW AS MUCH MOISTURE RETURN FROM THE GULF
OF MEXICO TO COME UP INTO THE FORECAST AREA. THUS...THE GFS ENDS UP
AS A DRY SOLUTION. ALL THE OTHER MODELS PRODUCE PRECIPITATION ON
WEDNESDAY WHICH SEEMS REASONABLE. THUS...THE 60 PERCENT CHANCES ARE
STILL ON TRACK. WEDNESDAY NIGHT IS A LITTLE MORE UP IN THE AIR...
THOUGH. THINGS IN PLAY WITH PRECIPITATION CHANCES INCLUDE: TRACK OF
THE UPPER LOW WITHIN THE TROUGH...A POSSIBLE DRY SLOT...AND A TROWAL
AND COLD CONVEYOR BELT AREA WRAPPING AROUND THE UPPER LOW. THE
PMDHMD FROM HPC DISCUSSES THIS SITUATION WELL...WITH MODELS ALL OVER
THE PLACE WITH THESE FEATURES AND ALL PLAUSIBLE. THEREFORE...PLAN ON
TAKING A CONSENSUS APPROACH. AS THE PMDHMD STATES TOO...THE SYSTEM
RESPONSIBLE FOR THE POTENT UPPER TROUGH IS IN A DATA SPARSE REGION
OF THE NORTHERN/NORTHEAST PACIFIC. SO IT MAY TAKE AWHILE BEFORE
MODELS SETTLE DOWN ON A SOLUTION WITH THE VARIOUS FEATURES. THE
CONSENSUS APPROACH RESULTS IN 30 TO 50 PERCENT CHANCES...HIGHEST
ACROSS THE NORTH. ALSO FOLLOWED THE CONSENSUS APPROACH FOR
TEMPERATURES. SHOULD STILL BE NEAR NORMAL ON WEDNESDAY WITH THE WARM
ADVECTION AHEAD OF A SURFACE COLD FRONTAL PASSAGE. HOWEVER...
TEMPERATURES LOOK TO FALL IN THE AFTERNOON AS THE FRONT PASSES AND
RAIN DEVELOPS. IF A DEEP DRY SLOT ENTERS THE PICTURE WEDNESDAY
NIGHT...LOWS COULD BOTTOM OUT IN 30S. HOWEVER...WILL PLAY MORE
CLOUDS AND WIND TO KEEP LOWS IN THE 40S.
.LONG TERM...THURSDAY THROUGH SUNDAY NIGHT
227 AM CDT MON OCT 15 2012
15.00Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES ARE IN FAIRLY GOOD
AGREEMENT ON HANDLING THE UPPER TROUGH AND ITS LIFT OUT NORTHEAST
AWAY FROM THE AREA. THE GFS AGAIN IS SLIGHTLY FAST...BUT ALL MODELS
AGREE THAT BY FRIDAY NIGHT...THE UPPER TROUGH WILL BE FAR ENOUGH
EAST OF THE AREA TO ALLOW CONDITIONS TO DRY OUT. UNTIL THEN...SAME
CONCERNS THAT WERE PRESENT ON WEDNESDAY NIGHT WITH POSITIONS OF THE
UPPER LOW IN THE TROUGH...DRY SLOT...TROWAL AND COLD CONVEYOR BELT
STILL PERSIST THROUGH FRIDAY. AS A RESULT...HAVE CONTINUED TO FOLLOW
A CONSENSUS APPROACH. HIGHEST CHANCES OF PRECIPITATION EXPECTED ON
THURSDAY SINCE THERE ARE INDICATIONS THAT THE TROUGH WILL FILL AFTER
THEN. COOL CONDITIONS ARE LIKELY TOO WITH THE UPPER TROUGH IN PLACE.
850MB TEMPS ARE ONLY PROGGED IN THE 0-2C RANGE. COMBINE THIS WITH
PRECIPITATION COULD END UP KEEPING HIGHS IN SOME LOCATIONS FROM EVEN
REACHING 50...ESPECIALLY ON THURSDAY.
FOR THE WEEKEND...MODELS ARE INDICATING THAT A POTENT UPPER TROUGH
WILL DROP SOUTH OUT OF THE GULF OF ALASKA AND AT LEAST INTO BRITISH
COLUMBIA. THE 14.12Z AND 15.00Z ECMWF RUNS AS WELL AS SOME OF THE
GFS ENSEMBLES TAKE IT ONE STEP FURTHER AND DIG THE TROUGH INTO THE
PACIFIC NORTHWEST. ALL SOLUTIONS THUS WOULD YIELD AT LEAST ZONAL
FLOW DOWNSTREAM INTO THE FORECAST AREA...RESULTING IN WARMING AND
DRY CONDITIONS. IN THE CASE OF THE ECMWF...RIDGING ENDS UP BUILDING
INTO THE FORECAST AREA. FOR NOW HAVE FOLLOWED THE CONSENSUS APPROACH
FOR TEMPERATURES GIVEN THE SPREAD IN HOW THE UPPER FLOW EVOLVES...
BUT SHOULD THE ECMWF VERIFY...TEMPERATURES MAY NEED TO BE INCREASED.
BY 18Z SUNDAY...THE ECMWF SUGGESTS 850MB TEMPS OF 10-14C...COMPARED
TO 4-8C FROM THE GFS.
&&
.AVIATION...TODAY AND TONIGHT
556 AM CDT MON OCT 15 2012
MVFR CONDITIONS AT KLSE IN SHALLOW FOG WILL RAPIDLY IMPROVE THIS
MORNING AFTER SUNRISE. OTHERWISE PLAN ON VFR CONDITIONS AT KLSE AND
KRST THROUGH THIS EVENING AS HIGH PRESSURE MOVES OVER THE UPPER
MISSISSIPPI RIVER VALLEY. WINDS WILL BE LIGHT OUT OF THE THE
WEST/NORTHWEST...GRADUALLY SWITCHING TO THE SOUTHWEST LATE THIS
AFTERNOON AS THE HIGH MOVES EAST OF THE REGION. A TROUGH OF LOW
PRESSURE WILL MOVE INTO THE AREA TONIGHT WITH CLOUDS INCREASING
AT THE TAF SITES. LOOK FOR CEILINGS TO LOWER INTO THE 9 TO 12 KFT
RANGE OVERNIGHT. WINDS WILL INCREASE OUT OF THE SOUTH TONIGHT INTO
THE 9 TO 15 KT RANGE. WILL HAVE TO KEEP A CLOSE WATCH ON THE
POTENTIAL FOR LOW LEVEL WIND SHEAR. FORECAST SOUNDINGS ARE SHOWING
WINDS INCREASING TO AROUND 45 KTS AT 2000FT. IT APPEARS SURFACE
WINDS WILL STAY UP JUST ENOUGH FOR KRST TO FALL SHORT OF LLWS
CRITERIA. SURFACE WINDS WILL BE LESS AT KLSE...AROUND 9KTS. THERE
IS UNCERTAINTY REGARDING HOW MUCH DECOUPLING WILL OCCUR TONIGHT SO
HAVE DECIDED NOT INCLUDE LOW LEVEL WIND SHEAR IN THE TAFS AT THIS
TIME. SPRINKLES ARE POSSIBLE AT THE TAF SITES TUESDAY MORNING AS
THE TROUGH MOVES IN.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
227 AM CDT MON OCT 15 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
227 AM CDT MON OCT 15 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
227 AM CDT MON OCT 15 2012
MAIN FORECAST CONCERN IS THE IMPACTS ON THE AREA FROM A DEEP UPPER
TROUGH DROPPING INTO THE NORTHERN PLAINS TUESDAY NIGHT.
CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT
ANALYSIS SHOWED NEARLY ZONAL FLOW ACROSS THE NORTHERN ROCKIES AND
SOUTHWEST CANADA...AND TROUGHING ACROSS THE WESTERN GREAT LAKES
REGION INTO ILLINOIS. THE FORECAST AREA LIES ON THE WESTERN SIDE
OF THIS TROUGHING...FAVORING SUBSIDENCE AND DRY AIR. 00Z SOUNDINGS
FROM ABR AND MPX REFLECT THESE ATTRIBUTES...WITH PRECIPITABLE
WATER VALUES NEAR 0.5 INCH. SATELLITE IMAGERY ALSO REFLECTS THE
DRY AIR WITH CLEARING ACROSS MUCH OF MINNESOTA AND IOWA. SOME
COOLER AIR TOO FLOWING IN ON THE BACK SIDE OF THE TROUGH WITH
850MB TEMPS OF 3C AT MPX AT 00Z. HOWEVER...WARMER READINGS OF
7-15C AT 850MB WERE OBSERVED IN THE DAKOTAS. AT THE SURFACE...A
RIDGE OF HIGH PRESSURE WAS PRESENT ACROSS WESTERN MINNESOTA WHILE
A NEW LOW PRESSURE SYSTEM WAS TAKING SHAPE ACROSS SOUTHERN
SASKATCHEWAN.
TODAY AND TONIGHT...FOCUS IS ON A COLLECTION OF SHORTWAVES IN THE
ZONAL FLOW OVER WASHINGTON. MODELS ARE IN GOOD AGREEMENT SENDING
THESE EAST INTO THE EASTERN DAKOTAS AND WESTERN MINNESOTA BY 12Z
TUESDAY. THERE EVEN APPEARS TO BE A WEAK TROUGH SIGNATURE IN THE
500MB HEIGHT FIELD AT 12Z WITH THESE SHORTWAVES. AS THESE SHORTWAVES
HEAD EAST...THEY WILL HELP PICK UP THE CURRENT SYSTEM IN SOUTH
CENTRAL SASKATCHEWAN...SENDING A TROUGH INTO MINNESOTA BY 12Z
TUESDAY. WARM ADVECTION AHEAD OF THIS SYSTEM WILL COMMENCE OVER THE
FORECAST AREA THIS AFTERNOON...WITH 850MB TEMPS TOPPING OUT BETWEEN
4-8C BY 00Z...WARMEST WEST. OTHER THAN SOME INCREASE IN WARM
ADVECTION HIGH AND PERHAPS MID CLOUDS AS WELL LATE IN THE DAY...
CURRENTLY OBSERVED CROSSING THE DAKOTAS...SHOULD SEE PLENTY OF SUN.
AS A RESULT...ANTICIPATING TEMPERATURES TO TOP OUT IN THE MID 50S TO
MID 60S. FOR TONIGHT...PLANNING ON THE MID AND HIGH CLOUDS TO
QUICKLY ENCOMPASS THE AREA...HELPING TO LIMIT TEMPERATURE FALL. IN
ADDITION...MODELS SHOW AN INCREASE OF 850MB MOISTURE TRANSPORT
THROUGH THE NIGHT AHEAD OF THE TROUGH COMING INTO MINNESOTA. NOSE OF
THIS MOISTURE TRANSPORT...AS WELL AS THE BULK OF ISENTROPIC LIFT...
APPEARS TO BE SITUATED MAINLY NORTH OF THE AREA. AS SUCH...EXPECTING
MOST PRECIPITATION TO STAY NORTH. HOWEVER...DID INTRODUCE A 20
PERCENT CHANCE IN TAYLOR COUNTY SINCE THEY LOOK TO BE RIGHT ON THE
EDGE OF WHERE THE WARM ADVECTION PRECIPITATION MAY EXIST. FOLLOWED A
BLEND OF GUIDANCE FOR LOWS.
TUESDAY...THE WEAK UPPER TROUGH SIGNATURE PRESENT OVER THE
EASTERN DAKOTAS AT 12Z TUESDAY IS FORECAST BY ALL MODELS TO CROSS
THE AREA ON TUESDAY. THE SAME QUESTIONS REMAIN IF THIS TROUGH CAN
PRODUCE PRECIPITATION AS IT MOVES THROUGH. THE 14.12Z ECMWF WAS MUCH
MORE IMPRESSIVE WITH QPF COMPARED TO ITS PREVIOUS RUN WITH MUCH OF
THE AREA AFFECTED. MEANWHILE THE 15.00Z NAM CONTINUES TO PAINT A
MOSTLY DRY SCENARIO OUTSIDE OF SOME LINGERING WARM ADVECTION PRECIP
OVER TAYLOR COUNTY IN THE MORNING. THE 15.00Z GFS LIES IN-BETWEEN
THE TWO SCENARIOS WITH QPF MAINLY IN THE MORNING ALONG AND NORTHEAST
OF I-94. THINKING THE ECMWF IS OVERDONE WITH THE AMOUNT OF QPF GIVEN
THE OVERALL LACK OF MOISTURE AVAILABILITY...ESPECIALLY IN THE LOWER
LEVELS. THEREFORE...HAVE STAYED CLOSE TO THE PREVIOUS FORECAST OF
20-30 PERCENT CHANCES ALONG AND NORTHEAST OF I-94. NEW 15.00Z ECMWF
HAS A LITTLE LESS QPF...AND FOCUSES ITS MAIN AREA SIMILAR TO WHERE
THE FORECAST HAS IT. TEMPERATURES ARE A BIT TRICKY ON TUESDAY AS
MUCH OF THE MORNING WILL LIKELY BE CLOUDY WITH MID AND HIGH CLOUDS
AROUND. AS THE TROUGH COMES THROUGH...THE OPPORTUNITY FOR CLEARING
EXISTS. 850MB TEMPS REALLY DO NOT COOL WITH THE TROUGH...HOVERING
BETWEEN 9C NORTH AND 13C SOUTH. HERE TOO WILL STAY PRETTY CLOSE TO
THE PREVIOUS FORECAST WITH HIGHS FROM THE MID 60S EAST (MOST CLOUDS)
TO LOW 70S WEST.
TUESDAY NIGHT...A VERY POTENT UPPER TROUGH IS PROGGED TO DIG DOWN
INTO MONTANA AND THE NORTHERN PLAINS BY 12Z WEDNESDAY. AS THIS
TROUGH DIGS IN...A COLD FRONT GETS SENT EASTWARD...PERHAPS REACHING
WESTERN PORTIONS OF THE FORECAST AREA BY 12Z WEDNESDAY. THE 15.00Z
GFS AND NAM...AS WELL AS THE 14.12Z/15.00Z ECMWF KEEP PRECIPITATION
NORTHWEST OF THE AREA THROUGH TUESDAY NIGHT. THIS SEEMS REASONABLE
GIVEN THAT THE BULK OF THE PRECIPITATION LOOKS TO OCCUR POST-FRONTAL
AND MORE ASSOCIATED WITH DPVA FROM THE POTENT TROUGH. AS SUCH...HAVE
REMOVED ANY LOW CHANCES OF PRECIPITATION IN FAR WESTERN PORTIONS OF
THE AREA. TEMPERATURES COULD DROP QUICKLY IN THE EVENING...
ESPECIALLY AT THE TYPICAL COLD SPOTS...WITH MOSTLY CLEAR SKIES AND A
BAGGY PRESSURE GRADIENT IN PLACE. INCREASING MID AND HIGH CLOUDS AS
WELL AS WINDS AHEAD OF THE FRONT AND UPPER TROUGH SHOULD HELP TO
HOLD TEMPERATURES STEADY OR EVEN RISE AFTER MIDNIGHT.
WEDNESDAY AND WEDNESDAY NIGHT...MODELS ARE IN REALLY GOOD AGREEMENT
THAT THE POTENT UPPER TROUGH WILL CONTINUE TO DIG SOUTHEASTWARD...
FULLY ENCOMPASSING THE AREA BY WEDNESDAY NIGHT. HOWEVER...THERE ARE
SOME IMPORTANT DETAILS WITHIN THE UPPER TROUGH THAT MODELS DIFFER
ON. THE FIRST IS WITH A SHORTWAVE EXTENDING SOUTH OF AN UPPER LOW
CONTAINED WITHIN THE TROUGH. THIS SHORTWAVE...PROGGED NEAR BISMARCK
NORTH DAKOTA AT 12Z WEDNESDAY...THE 15.00Z GFS IS MUCH FASTER THAN
ANY OTHER MODEL WITH IT BY BRINGING IT INTO THE FORECAST AREA BY
00Z. THE 15.00Z NAM/UKMET/CANADIAN/ECMWF ARE ALL SLOWER...ONLY
REACHING WESTERN MINNESOTA BY 00Z. THIS IS A SIGNIFICANT ISSUE AS
THE FASTER GFS WOULD NOT ALLOW AS MUCH MOISTURE RETURN FROM THE GULF
OF MEXICO TO COME UP INTO THE FORECAST AREA. THUS...THE GFS ENDS UP
AS A DRY SOLUTION. ALL THE OTHER MODELS PRODUCE PRECIPITATION ON
WEDNESDAY WHICH SEEMS REASONABLE. THUS...THE 60 PERCENT CHANCES ARE
STILL ON TRACK. WEDNESDAY NIGHT IS A LITTLE MORE UP IN THE AIR...
THOUGH. THINGS IN PLAY WITH PRECIPITATION CHANCES INCLUDE: TRACK OF
THE UPPER LOW WITHIN THE TROUGH...A POSSIBLE DRY SLOT...AND A TROWAL
AND COLD CONVEYOR BELT AREA WRAPPING AROUND THE UPPER LOW. THE
PMDHMD FROM HPC DISCUSSES THIS SITUATION WELL...WITH MODELS ALL OVER
THE PLACE WITH THESE FEATURES AND ALL PLAUSIBLE. THEREFORE...PLAN ON
TAKING A CONSENSUS APPROACH. AS THE PMDHMD STATES TOO...THE SYSTEM
RESPONSIBLE FOR THE POTENT UPPER TROUGH IS IN A DATA SPARSE REGION
OF THE NORTHERN/NORTHEAST PACIFIC. SO IT MAY TAKE AWHILE BEFORE
MODELS SETTLE DOWN ON A SOLUTION WITH THE VARIOUS FEATURES. THE
CONSENSUS APPROACH RESULTS IN 30 TO 50 PERCENT CHANCES...HIGHEST
ACROSS THE NORTH. ALSO FOLLOWED THE CONSENSUS APPROACH FOR
TEMPERATURES. SHOULD STILL BE NEAR NORMAL ON WEDNESDAY WITH THE WARM
ADVECTION AHEAD OF A SURFACE COLD FRONTAL PASSAGE. HOWEVER...
TEMPERATURES LOOK TO FALL IN THE AFTERNOON AS THE FRONT PASSES AND
RAIN DEVELOPS. IF A DEEP DRY SLOT ENTERS THE PICTURE WEDNESDAY
NIGHT...LOWS COULD BOTTOM OUT IN 30S. HOWEVER...WILL PLAY MORE
CLOUDS AND WIND TO KEEP LOWS IN THE 40S.
.LONG TERM...THURSDAY THROUGH SUNDAY NIGHT
227 AM CDT MON OCT 15 2012
15.00Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES ARE IN FAIRLY GOOD
AGREEMENT ON HANDLING THE UPPER TROUGH AND ITS LIFT OUT NORTHEAST
AWAY FROM THE AREA. THE GFS AGAIN IS SLIGHTLY FAST...BUT ALL MODELS
AGREE THAT BY FRIDAY NIGHT...THE UPPER TROUGH WILL BE FAR ENOUGH
EAST OF THE AREA TO ALLOW CONDITIONS TO DRY OUT. UNTIL THEN...SAME
CONCERNS THAT WERE PRESENT ON WEDNESDAY NIGHT WITH POSITIONS OF THE
UPPER LOW IN THE TROUGH...DRY SLOT...TROWAL AND COLD CONVEYOR BELT
STILL PERSIST THROUGH FRIDAY. AS A RESULT...HAVE CONTINUED TO FOLLOW
A CONSENSUS APPROACH. HIGHEST CHANCES OF PRECIPITATION EXPECTED ON
THURSDAY SINCE THERE ARE INDICATIONS THAT THE TROUGH WILL FILL AFTER
THEN. COOL CONDITIONS ARE LIKELY TOO WITH THE UPPER TROUGH IN PLACE.
850MB TEMPS ARE ONLY PROGGED IN THE 0-2C RANGE. COMBINE THIS WITH
PRECIPITATION COULD END UP KEEPING HIGHS IN SOME LOCATIONS FROM EVEN
REACHING 50...ESPECIALLY ON THURSDAY.
FOR THE WEEKEND...MODELS ARE INDICATING THAT A POTENT UPPER TROUGH
WILL DROP SOUTH OUT OF THE GULF OF ALASKA AND AT LEAST INTO BRITISH
COLUMBIA. THE 14.12Z AND 15.00Z ECMWF RUNS AS WELL AS SOME OF THE
GFS ENSEMBLES TAKE IT ONE STEP FURTHER AND DIG THE TROUGH INTO THE
PACIFIC NORTHWEST. ALL SOLUTIONS THUS WOULD YIELD AT LEAST ZONAL
FLOW DOWNSTREAM INTO THE FORECAST AREA...RESULTING IN WARMING AND
DRY CONDITIONS. IN THE CASE OF THE ECMWF...RIDGING ENDS UP BUILDING
INTO THE FORECAST AREA. FOR NOW HAVE FOLLOWED THE CONSENSUS APPROACH
FOR TEMPERATURES GIVEN THE SPREAD IN HOW THE UPPER FLOW EVOLVES...
BUT SHOULD THE ECMWF VERIFY...TEMPERATURES MAY NEED TO BE INCREASED.
BY 18Z SUNDAY...THE ECMWF SUGGESTS 850MB TEMPS OF 10-14C...COMPARED
TO 4-8C FROM THE GFS.
&&
.AVIATION...THROUGH 06Z TUESDAY
1139 PM CDT SUN OCT 14 2012
CLEAR SKIES AND RECENT RAINS HAVE ALLOWED SOME FOG TO FORM AT KLSE
BUT IT IS HAVING PROBLEMS SUSTAINING ITSELF DUE TO SOME STRONGER
WINDS JUST ABOVE THE RIDGE TOP LEVEL AND DRIER AIR THAT IS SLOWLY
ADVECTING IN FROM THE NORTH. THE FOG WILL ALSO BE INHIBITED FOR A
WHILE AS A DECK OF MID LEVEL CLOUDS MOVES ACROSS THE REGION.
EXPECTING THESE TO CLEAR OUT SOON ENOUGH TO POSSIBLY ALLOW THE FOG
TO REFORM AGAIN LATE TONIGHT WHEN THE 15.00Z NAM SOUNDING SUGGEST
SATURATION AT THE SURFACE COULD OCCUR. THIS FOG SHOULD THEN
DISSIPATE SHORTLY AFTER SUNRISE LEAVING CLEAR SKIES AND VFR
CONDITIONS FOR MUCH OF MONDAY AT BOTH TAF SITES. THE NEXT SHORT
WAVE TROUGH WILL QUICKLY BE APPROACHING FROM THE NORTHWEST AND
SHOULD START TO SPREAD IN A DECK OF MID LEVEL CLOUDS DURING THE
LATE AFTERNOON. UPSTREAM OBSERVATIONS ACROSS NORTH DAKOTA AND
MONTANA INDICATE THESE CLOUDS SHOULD BE AROUND 10K FEET WITH SKIES
QUICKLY GOING FROM CLEAR TO BROKEN.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
227 AM CDT MON OCT 15 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1139 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 06Z TUESDAY
1139 PM CDT SUN OCT 14 2012
CLEAR SKIES AND RECENT RAINS HAVE ALLOWED SOME FOG TO FORM AT KLSE
BUT IT IS HAVING PROBLEMS SUSTAINING ITSELF DUE TO SOME STRONGER
WINDS JUST ABOVE THE RIDGE TOP LEVEL AND DRIER AIR THAT IS SLOWLY
ADVECTING IN FROM THE NORTH. THE FOG WILL ALSO BE INHIBITED FOR A
WHILE AS A DECK OF MID LEVEL CLOUDS MOVES ACROSS THE REGION.
EXPECTING THESE TO CLEAR OUT SOON ENOUGH TO POSSIBLY ALLOW THE FOG
TO REFORM AGAIN LATE TONIGHT WHEN THE 15.00Z NAM SOUNDING SUGGEST
SATURATION AT THE SURFACE COULD OCCUR. THIS FOG SHOULD THEN
DISSIPATE SHORTLY AFTER SUNRISE LEAVING CLEAR SKIES AND VFR
CONDITIONS FOR MUCH OF MONDAY AT BOTH TAF SITES. THE NEXT SHORT
WAVE TROUGH WILL QUICKLY BE APPROACHING FROM THE NORTHWEST AND
SHOULD START TO SPREAD IN A DECK OF MID LEVEL CLOUDS DURING THE
LATE AFTERNOON. UPSTREAM OBSERVATIONS ACROSS NORTH DAKOTA AND
MONTANA INDICATE THESE CLOUDS SHOULD BE AROUND 10K FEET WITH SKIES
QUICKLY GOING FROM CLEAR TO BROKEN.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
307 PM CDT SUN OCT 14 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RABERDING
LONG TERM...RABERDING
AVIATION...04
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
329 AM EDT WED OCT 17 2012
.DISCUSSION...
TODAY-TONIGHT...A WEAK HI PRES RIDGE OVER THE DEEP SOUTH AND THE FL
PENINSULA WILL DISSOLVE AS IT MOVES OFF THE ATLC COAST TODAY. A MUCH
DRIER AIRMASS ASSOCD WITH THE RIDGE WILL MODIFY RAPIDLY AS A STRONG
ZONAL FLOW PATTERN OVER THE GOMEX/SRN CONUS PULLS A MID LVL IMPULSE
ACRS FL. EVEN SO...PWAT VALUES ARE QUITE LOW OVER THE N HALF OF
FL...RANGING FROM 0.4" AT KJAX/KTAE TO 1.0" AT KTBW. MOISTURE IS A
BIT HIGHER OVER S FL WITH KMFL MEASURING 1.5" PWAT ON THEIR 17/00Z
SOUNDING... MAINLY IN THE H100-H70 LYR.
MOISTURE ASSOCD WITH THE LEADING EDGE OF THE IMPULSE IS LARGELY
MID/UPR LVL DEBRIS CLOUDS THAT WILL MODIFY THE DRY AIR FROM THE TOP
DOWN. THIS WILL LIMIT SFC HEATING AND LOW LVL DESTABILIZATION OVER
MUCH OF CENTRAL FL TODAY. INDEED...LATEST SAT OBS SHOW SUBSTANTIAL
DEBRIS CLOUDS ALREADY PUSHING ACRS THE PANHANDLE AND MOST OF THE
CENTRAL/NRN PENINSULA...BUT RADAR OBS SHOW LITTLE IF ANY RAINFALL.
DESPITE SOME FAVORABLE DYNAMIC LIFTING MECHANISMS...STRONG/SVR WX
POTENTIAL WILL BE QUITE LOW TODAY. LATEST RAP ANALYSIS SHOWS
RESPECTABLE MID LVL LAPSE RATES BTWN 5.5-6.5C/KM...BUT RIDING AHEAD
OF THE DEEPER MOISTURE. A MID LVL THERMAL TROF OVER THE FL
PANHANDLE/NE GOMEX WILL BRIEFLY DROP H50 TEMPS TO BTWN -10C AND -12C
ALONG AND N OF THE I-4 CORRIDOR THIS MORNING...BUT WILL LIFT OUT BY
MIDDAY BEFORE THE AIRMASS CAN FULLY MODIFY. STRONG UPR LVL
DIVERGENCE AND RESPECTABLE MID LVL VORTICITY WILL BE PRESENT AS A
90KT H30-H20 JET STREAK RACES ACRS THE NRN GOMEX. HOWEVER...THESE
WILL BE HAMPERED BY WEAK SFC/LOW LVL INSTABILITY DUE TO THE INCOMING
DEBRIS CLOUDS.
BEST RAINFALL CHANCES WILL BE OVER THE SRN CWA WHERE LOW LVL
MOISTURE IS THE HIGHEST AND MID/UPR LVL DEBRIS CLOUDS ARE THINNEST.
WILL GO WITH 60 POPS AROUND THE LAKE OKEECHOBEE REGION...DECREASING
TO 30 POPS OVER VOLUSIA AND NRN LAKE COUNTY TODAY. SUFFICIENT
MOISTURE WILL REMAIN IN PLACE AFT SUNSET TO KEEP 20-40 POPS IN THE
FCST FOR THE FIRST HALF OF THE OVERNIGHT PD...AGAIN BEST CHANCES
WILL BE OVER THE SRN CWA DUE TO THE MOISTURE PROFILE. CLOUDS/RAIN
WILL KEEP MAX TEMPS IN THE U70S/L80S. LINGERING CLOUDS AND LIGHT
SRLY FLOW OVERNIGHT WILL KEEP MIN TEMPS IN THE M/U60S OVER MOST OF
ECFL...L70S ALONG THE IMMEDIATE COAST S OF SEBASTIAN INLET.
THU-SAT...WEATHER FOR MUCH OF THE EASTERN HALF OF THE NATION WILL BE
INFLUENCED BY A LARGE VORTEX AT MID/UPPER LEVELS AS IT TREKS FROM
MIDWEST ACROSS THE GREAT LAKES DURING THE LATE WEEK. EC FL WILL BE
LOCATED IN RELATIVELY WARM SWLY FLOW THURS AND FRI BEFORE A WEAK
COLD FRONT PASSES ON SATURDAY. MOISTURE WILL BE FAIRLY LIMITED IN
THIS TIMEFRAME. LOW POPS MAINLY CONFINED TO SOUTHERN SECTIONS ON
THURSDAY. A LOW POP MENTIONED FOR ALL AREAS ON FRI WITH A SLIGHT
UPTICK IN MOISTURE. WITH FRONT MOVING THROUGH ON SATURDAY LOW
MENTIONABLE POPS WILL BE MAINLY CONFINED TO AREAS NEAR AND SOUTH OF
THE FRONTAL BOUNDARY. HIGH TEMPS MID/UPPER 80S INLAND AND LOW/MID
80S COAST. OVERNIGHT LOWS MID/UPPER 60S EXCEPT NEAR 70/LOWER 70S
ALONG THE COAST SOUTH OF THE CAPE.
SUN-WED...SURFACE HIGH PRESSURE TO THE NORTH BUILDING ALONG THE
EASTERN SEABOARD AND RIDGE ALOFT BUILDING ACROSS THE STATE FROM THE
GULF OF MEXICO. THIS WILL BRING ONSHORE FLOW REGIME TO EC FL WITH
SLOW INCREASE IN MOISTURE AND TEMPS MODERATED BY THE ONSHORE FLOW.
WILL KEEP POPS BELOW MENTIONABLE VALUES FOR NOW...BUT SOME LOW POPS
FOR COASTAL SHOWERS MAY BECOME WARRANTED.
&&
.AVIATION...THRU 17/17Z...VFR ALL SITES...CIGS AOA FL120. BTWN
17/17-17/23Z... NMRS MVFR SHRAS/SCT IFR TSRAS S OF KVRB-KBOW...SCT
MVFR SHRAS/ISOLD IFR TSRAS N OF KVRB-KBOW...PREVAILING CIGS BTWN
FL080-100. AFT 17/23Z...CHC MVFR SHRAS S OF KOMN-KISM...SLGT CHC
MVFR SHRAS N OF KOMN-KISM...PREVAILING CIGS BTWN FL100-120.
&&
.MARINE...TODAY-TONIGHT...A WEAK HI PRES RIDGE OVER THE DEEP S AND
MID ATLC COAST WILL WEAKEN AS IT PUSHES INTO THE W ATLC. GENTLE TO
MODERATE E/NE BREEZE TODAY WILL VEER TO THE S OVERNIGHT AS A NEW
FRONTAL TROF PUSHES THE LWR MS VALLEY AND INTO THE DEEP SOUTH. LONG
PD SWELL FROM T.C. RAFAEL WILL IMPACT THE LCL ATLC AND MAINTAIN SEAS
BTWN 4-6FT HIGHER THAN WHAT THE CURRENT SFC/BNDRY LYR WINDS WOULD
SUPPORT.
BUOY010 MEASURING 8-9FT SEAS...BUOY MEASURING 6-7FT SEAS...BOTH
WITH DOMINANT PDS BTWN 12-14SEC. HOWEVER...PGRAD IS EXPECTED TO
SLACKEN AS THE RIDGE WEAKENS...RESULTING IN SFC/BNDRY LYR WINDS AOB
10KTS. THIS TREND IS ALREADY PLAYING OUT AT BUOY012 WHERE SFC WNDS
HAVE DIMINISHED FROM ARND 15KTS LAST NIGHT TO ARND 10KTS EARLY THIS
MRNG. WILL HOLD OFF ON AN ADVISORY BUT WILL GO WITH A CAUTIONARY
STATEMENT AREAWIDE TO ACCOUNT FOR THE SWELL.
THU-MON...LINGERING SWELLS FROM RAFAEL WILL DECREASE LATE WEEK INTO
THIS WEEKEND. WINDS RELATIVELY LIGHT THU-FRI WITH HIGH PRESSURE IN
CLOSE PROXIMITY. WINDS WILL PICK UP OUT OF THE NNE-NE SAT AS FRONT
MOVES DOWN THE WATERS. ONSHORE FLOW REGIME DEVELOPING BEHIND THE
FRONT SUNDAY INTO EARLY PART OF NEXT WEEK WITH HIGH PRESSURE TO THE
NORTH BUILDING ALONG THE EASTERN SEABOARD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 79 66 85 67 / 30 30 10 10
MCO 81 65 86 67 / 40 20 10 10
MLB 79 69 84 70 / 50 30 10 10
VRB 81 70 86 69 / 50 30 10 10
LEE 80 64 86 66 / 30 20 10 10
SFB 80 65 86 67 / 40 20 10 10
ORL 81 66 86 67 / 40 20 10 10
FPR 81 71 85 69 / 60 40 20 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM....GLITTO
AREA FORECAST DISCUSSION
NWS DES MOINES IA
353 AM CDT WED OCT 17 2012
.SHORT TERM /TODAY/...
SEVERAL FORECAST CONCERNS TODAY WITH STRONG
COLD FRONT EXPECTED TO SWEEP ACROSS IOWA THIS MORNING. FROPA WILL BE
BETWEEN 11-15Z THIS MORNING FROM WEST TO EAST ACROSS THE FORECAST
AREA. LEANED TOWARD A BLEND OF THE SHORT TERM HIGH-RESOLUTION MODELS
HRRR/4.0KM WRF AND SREF/NAM12 AS THEY SEEMED TO HAVE BEST HANDLE ON
TIMING OF FRONT AND POPS.
SHARP PRESSURE GRADIENT COMBINED WITH A DECENT TROPOPAUSE UNDULATION
LATE THIS MORNING INTO THE AFTERNOON WILL PROVIDE A WINDY DAY. WINDS
ATOP THE MIX LAYER RANGE FROM 30-35KTS WEST OF THE INTERSTATE 35 AND
WITH THE CLOUDS CLEARING OUT THIS AFTERNOON IN WESTERN IOWA...SHOULD
ENHANCE THE WIND GUSTS. TWEAKED WINDS UP SLIGHTLY IN THIS AREA
THROUGH 18Z. STILL BORDER LINE WIND ADVISORY ATTM. KEPT MENTION OF
THE NON-DIURNAL TEMPS WITH THE STRONG CAA DEVELOPING LATE THIS
MORNING. 850MB TEMPS DROP TO +2C TO +4C BY THIS AFTERNOON. A NICE
STRATUS DECK LOOKS TO MOVE IN BY AROUND 00Z THURSDAY AS RH AT 850MB
INCREASES GREATER THAN 80 PERCENT. INCREASED SKY COVER ACROSS THE FAR
NORTHWEST.
BEST POPS WILL BE ACROSS THE SOUTHEAST LATE THIS MORNING WHERE
STRONGEST FORCING AND BEST THETA-E ADVECTION IS LOCATED. IN
ADDITION...SOME ELEVATED INSTABILITY IS PRESENT AND LIKELY WILL THE
HIGHER QPF AMOUNTS. THE LATEST HRRR COINCIDES WITH THIS THINKING AND
TWEAKED UP QPF THROUGH 18Z.
.LONG TERM /TONIGHT THROUGH TUESDAY/...
DEEPENING UPPER LOW WILL BE DIVING INTO MINNESOTA AND IOWA OVERNIGHT
WITH AN IMPRESSIVE 90-100KT JET ROUNDING THE BASE OF THE TROUGH AND
BEING INGESTED INTO THE SYSTEM THROUGH THURSDAY. THERE IS A
SIGNIFICANT AMOUNT OF ENERGY EMBEDDED IN THE FLOW WHICH WILL WRAP
AROUND THE SYSTEM THE NEXT FEW DAYS. ONE OF THE MORE VIGOROUS
IMPULSES IS MOVING THROUGH SRN IA AND MISSOURI TODAY AND WILL WRAP
AROUND THE SYSTEM AND MOVE ACROSS MINNESOTA AND IOWA ON THURSDAY AND
WILL SHIFT THE AXIS OF THE UPPER LOW BACK WEST A BIT. THIS SYSTEM
WILL ALSO HAVE GOOD THETA-E ADVECTION EMBEDDED WHICH WILL HELP PUSH
PWATS BACK TO NEAR 0.75 INCHES AND COMBINED WITH THE KINEMATIC
ENERGY...SHOULD RESULT IN WIDESPREAD SHOWERS BY THURSDAY AFTERNOON
AND EVENING. IN ADDITION...AN INCREASING PRESSURE GRADIENT OVER
WESTERN IOWA AND WINDS APPROACHING 50 KTS IN THE LOWEST 4 KFT OF THE
ATMOSPHERE DOES RAISE CONCERNS ABOUT POTENTIAL WIND ADVISORY
CRITERIA. IT WILL BE CLOSE...WEST OF INTERSTATE 35 THOUGH THERE ARE
A FEW NEGATIVES THAT WILL KEEP THE WINDS FROM REACHING MAX
POTENTIAL. A STRATUS DECK SHOULD ENGULF MUCH OF IOWA ON THURSDAY AND
THIS WILL LIMIT HIGH TEMPERATURES AND POTENTIAL FOR MIXING.
TEMPERATURES WILL LIKELY LINGER IN THE 40S FOR MUCH OF THE DAY. THE
GOOD REGION OF SUBSIDENCE WILL BE WEST OF THE MISSOURI RIVER AND
THAT WILL BE THE REGION FOR GOOD MOMENTUM TRANSFER AND BETTER MIXING
OF WINDS ALOFT.
PRECIPITATION CHANCES WILL CONTINUE THURSDAY NIGHT BEFORE THE BULK
OF THE ENERGY ROUNDS THE BASE OF THE UPPER LOW AND IT BEGINS TO
SHIFT OFF TO THE EAST ON FRIDAY. A FEW SHOWERS MAY LINGER FRIDAY
BEFORE MID LEVEL RIDGING MOVES IN FOR THE WEEKEND WITH WARMER
TEMPERATURES. STRENGTHENING HIGH PRESSURE OVER THE SOUTHEAST CONUS
AND REGION OF LOW PRESSURE TO THE WEST WILL ENHANCE THE WARM
ADVECTION INTO SUNDAY. AS MENTIONED LAST NIGHT...THIS SET UP IS
CONDUCIVE TO A STRONG SURGE OF LOW LEVEL GULF MOISTURE. SOME MINOR
TIMING DETAILS ON WHEN THIS MOISTURE ARRIVES IN IOWA...EITHER LATE
SUNDAY OR SUNDAY NIGHT. THIS MOISTURE WILL LIFT NORTH AND POOL AHEAD
OF A SFC BOUNDARY THAT WILL BE INCHING SOUTHEAST THROUGH IOWA SUNDAY
THROUGH MONDAY. THIS TYPE OF MOISTURE OFTEN RESULTS IN A STRATUS
FIELD AND MAY BE ACCOMPANIED WITH FOG OR DRIZZLE. ENHANCED VERTICAL
TURBULENCE WITH THE SFC BOUNDARY NEAR BY ENHANCES THAT POSSIBILITY.
ANY STRATUS CERTAINLY WOULD IMPACT TEMPERATURES. A SHORT WAVE
LIFTING THROUGH THE SOUTHWEST FLOW WILL INTRODUCE SOME CONVECTIVE
POTENTIAL MONDAY AND MONDAY NIGHT. THE MILD SOUTHWEST FLOW WILL
MAINTAIN THROUGH THE END OF THE EXTENDED WITH HIGHS IN THE 60S AND
70S.
&&
.AVIATION...17/06Z
VFR CONDITIONS WILL PREVAIL ACROSS ALL TAF SITES THROUGH AT LEAST
17/11Z. AN UPPER LEVEL SYSTEM AND AN ASSOCIATED COLD FRONT WILL
SWEEP THROUGH ALL TAF SITES TODAY...PROVIDING A WIND SHIFT TO STRONG
GUSTY WEST/NORTHWESTERLIES AND SOME POST FRONTAL PRECIPITATION. THE
PRECIPITATION WILL BE GENERALLY LIGHT...ESPECIALLY ACROSS
NORTHWESTERN SITES...BUT SOME BRIEF MVFR CIGS MAY ACCOMPANY THIS
PRECIPITATION BAND AS IT SLIDES ACROSS ALL TAF SITES. HAVE DECIDED
NOT TO INCLUDE ATTM DUE TO THE EXPECTED BREVITY...BUT THIS POTENTIAL
WILL BE FINE TUNED IN THE COMING FORECASTS. GUSTS WILL DIE DOWN
TOWARDS THE END OF THE PERIOD...BUT WINDS WILL REMAIN RATHER BRISK
AT 15-20 KTS THROUGH THE END OF THE TAF PERIOD.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...DONAVON
AVIATION...DEITSCH
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1233 AM EDT WED OCT 17 2012
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN ACROSS THE REGION ON WEDNESDAY RIGHT
THROUGH WEDNESDAY NIGHT. THE HIGH WILL MOVE EAST OF THE STATE ON
THURSDAY.
&&
.NEAR TERM /THROUGH TODAY/...
1230AM UPDATE...
NO MAJOR CHANGES. RAISED OVERNIGHT LOWS SLIGHTLY AS WINDS PERSIST.
REDUCED DEW POINTS FOR WEDNESDAY AS AIR LOOKS DRIER THAN
PREVIOUSLY THOUGHT.
UPDATE: LAST BIT OF SHOWERS EXITING THE NORTHERN TIER AND CLOUDS
BEGINNING TO BREAK UP. THE CANADIAN GEM AND RUC DOING OK W/SLOWLY
CLEARING THINGS OUT OVERNIGHT. TEMPERATURES HOLDING UP A BIT
LONGER THAN PRECIOUS ANTICIPATED AND THEREFORE, SLOWED UP THE
COOLING PROCESS BY 2 HRS. REST OF THE FCST LOOKS FINE.
PREVIOUS DISCUSSION...
LOW PRES WILL QUICKLY LIFT NORTHEAST AND MOVE AWAY TONIGHT AS HIGH
PRESSURE BUILDS OVER THE STATE. CLEARING THROUGHOUT THE REGION
TONIGHT W/TEMPS DROPPING TO NEAR OR JUST BELOW FREEZING IN MOST
AREAS. HIGH PRESSURE WILL REMAIN OVER THE REGION WEDNESDAY
BRINGING SUNSHINE WITH AFTERNOON TEMPS RANGING FROM THE UPPER 50S
DOWNEAST TO THE LOW 50S OVER THE NORTH. WINDS WILL BE VERY LIGHT
AS THE HIGH CRESTS OVER THE REGION.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY/...
NORTHERN NEW ENGLAND WILL BEGIN THIS FORECAST PERIOD UNDERNEATH AN
UPPER RIDGE. THIS WILL ALLOW FOR ABOVE NORMAL TEMPERATURES AND
DRY WEATHER. HIGH CLOUDS WILL SPILL OVER THE RIDGE AXIS FOR MOSTLY
CLOUDY SKIES. WILL HAVE TO WATCH OUT FOR LOW CLOUDS AND FOG ALONG
THE COASTAL ZONES LATE THURSDAY NIGHT AND EARLY FRIDAY MORNING DUE
TO A STRONG ONSHORE FLOW.
WINDS WILL INCREASE ON FRIDAY AS AN OCCLUDED FRONT APPROACHES FROM
THE WEST. EXPECT RAIN OR RAIN SHOWERS TO DEVELOP DURING THE DAY
ACROSS NORTHERN AND DOWNEAST MAINE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AN OCCLUDED FRONT WILL CROSS THE REGION FRIDAY NIGHT THROUGH
SATURDAY NIGHT...THOUGH UNCERTAINTY STILL EXISTS REGARDING HOW
QUICKLY THE FRONT MOVES EAST OF THE REGION LATER SATURDAY THROUGH
SATURDAY NIGHT. AN AREA OF RAIN WILL CROSS THE REGION IN ADVANCE
OF THE OCCLUSION FRIDAY NIGHT INTO SATURDAY...THEN TAPER TO
SHOWERS IN THE WAKE OF THE FRONT LATER SATURDAY INTO SATURDAY
NIGHT DEPENDENT ON THE TIMING OF THE FRONT. SHOWERS WRAPPING
AROUND THE EXITING SYSTEM COULD BRING A CHANCE OF SHOWERS TO THE
NORTH/MOUNTAINS SUNDAY...WITH PARTLY CLOUDY SKIES DOWNEAST. HIGH
PRESSURE SHOULD THEN BUILD ACROSS THE REGION MONDAY. A COLD FRONT
COULD THEN BRING A CHANCE OF SHOWERS TUESDAY. TEMPERATURES SHOULD
BE AT SLIGHTLY ABOVE NORMAL LEVELS SATURDAY THROUGH MONDAY...WITH
NEAR NORMAL LEVEL TEMPERATURES TUESDAY.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: CONDITIONS WILL IMPROVE TO VFR TONIGHT THEN REMAIN VFR
IN MOSTLY CLEAR SKIES ON WEDNESDAY.
SHORT TERM: MVFR CIGS AND VSBYS ARE POSSIBLE AT KBHB AND KBGR LATE
THURSDAY NIGHT AND EARLY FRIDAY MORNING DUE TO LOW CLOUDS AND FOG.
MVFR CIGS AND VSBYS ARE POSSIBLE FRIDAY AFTERNOON AT ALL TAF SITES
DUE TO LOW CLOUDS AND SHOWERS AS AN OCCLUDED FRONT MOVES INTO THE
REGION. MVFR/IFR CONDITIONS ARE EXPECTED ACROSS THE REGION FRIDAY
NIGHT INTO EARLY SATURDAY NIGHT...WITH MVFR CONDITIONS LATER
SATURDAY NIGHT. OCCASIONAL MVFR CONDITIONS COULD LINGER ACROSS
THE NORTH/MOUNTAINS SUNDAY...WITH VFR CONDITIONS DOWNEAST.
&&
.MARINE...
NEAR TERM: AN SCA WILL CONTINUE OVERNIGHT. WINDS WILL DIMINISH
BY MORNING AS THE HIGH CRESTS OVER THE WATERS.
SHORT TERM: SCA CONDITIONS ARE LIKELY THURSDAY WITH WAVE HEIGHTS IN
THE 4 TO 7 FOOT RANGE AND FRIDAY WITH WAVE HEIGHTS IN THE 6 TO 9
FOOT RANGE AND WIND GUSTS IN EXCESS OF 25 KNOTS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING FOR
ANZ050>052.
&&
$$
NEAR TERM...HEWITT/MCW
SHORT TERM...
LONG TERM...
AVIATION...HEWITT/MCW
MARINE...HEWITT/MCW/
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
145 AM EDT WED OCT 17 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 431 PM EDT TUE OCT 16 2012
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW ZONAL FLOW ALF
OVER THE UPR LKS. SHRTWV EMBEDDED WITHIN THIS FLOW IS MOVING THRU
ONTARIO/MN. COMBINATION OF ISENTROPIC ASCENT BEST DEPICTED ON THE
295-300K SFCS/H7 MSTR CNVGC AND UPR DVGC IN RRQ OF 80KT H3 JET MAX
MOVING THRU SE CANADA IS CAUSING AN AREA OF SHRA OVER THE UPR LKS
THIS AFTN. THE PCPN IS MOST WIDESPREAD OVER THE N AND CNTRL CWA...
WITH DRIER AIR BLO H75 DEPICTED ON THE 12Z GRB RAOB AND MORE
IMPRESSIVE ISENTROPIC ASCENT TO THE N RESTRICTING PCPN COVERAGE OVER
THE SCNTRL. TO THE W...DNVA/MID LVL DRYING/LARGER SCALE QVECTOR DVGC
IN THE WAKE OF THE SHRTWV ARE BRINGING A DRYING TREND IN MN...WITH
THE BACK EDGE OF THE RA AREA PUSHING THRU WRN LK SUP EARLY THIS
AFTN. SKIES ARE MOCLR OVER THE NRN PLAINS INTO MN UNDER THE RDG
TRAILING THE SHRTWV. ANOTHER POTENT SHRTWV EMBEDDED IN THE ZONAL
FLOW ALF IS PUSHING INTO THE NRN ROCKIES. THERE WERE SOME 00Z-12Z H3
HGT FALLS IN EXCESS OF 200M ASSOCIATED WITH THIS DISTURBANCE.
MAIN FCST CONCERNS IN THE SHORT TERM REVOLVE ARND PCPN/CLD TRENDS
THRU THE REST OF THIS AFTN THEN TO POTENTIAL FOR FOG TNGT AS DRIER
AIR ALF OVERSPREADS THE AREA. FOCUS FOR WED TURNS TO PCPN CHCS
ASSOCIATED WITH SHRTWV NOW MOVG THRU THE NRN ROCKIES.
LATE TDAY...BEST H7 MSTR TRANSPORT/UPR DVGC INDICATES THE HEAVIER/
MORE WDSPRD SHRA WL SHIFT INTO THE ERN ZNS WHILE DRYING ALF/LARGER
SCALE QVECTOR DVGC ENDS THE PCPN OVER THE W.
TNGT...EXPECT LINGERING SHRA OVER THE E TO END BY MIDNGT WITH THE
PASSAGE OF THE SHRTWV/ARRIVAL OF DRYING ALF AND DNVA/LARGE SCALE
QVECTOR DVGC. GIVEN THE UPR DRYING/CLD TRENDS...EXPECT CLRG TO
OVERSPREAD THE AREA. WITH LINGERING LLVL MSTR...SUSPECT FOG WL DVLP.
WITH A FAIRLY STEADY SSE WIND...THE BEST CHC FOR MORE WDSPRD/DENSER
FOG AND LO CLDS WL BE OVER THE CNTRL ZNS WHERE THAT FLOW UPSLOPES.
TENDED TOWARD THE LO END OF GUIDANCE FOR MIN TEMPS GIVEN EXPECTED
DRYING ALF...BUT STEADY WIND WL RESTRICT THE FALL FM GOING TOO FAR.
WED...THE AT LEAST THE MRNG SHOULD BE DRY WITH LINGERING DRY AIR/UPR
RDG STILL IN PLACE. BUT STRONG SHRTWV NOW MOVING THRU THE NRN
ROCKIES IS FCST TO CLOSE OFF AND DRIFT INTO FAR NW MN BY 00Z THU. AS
SFC LO MOVES INTO NE MN...ATTENDANT COLD FNT IS PROGGED TO APRCH IWD
LATE IN THE DAY. LOOKS LIKE MOST IMPRESSIVE DPVA/DEEP LYR QVECTOR
CNVGC ASSOCIATED WITH THE SHRTWV WL STAY TO THE NW OF THE AREA WHILE
ANOTHER AREA OF DEEP LYR FORCING/UPR DVGC PASSES WELL TO THE S
CLOSER TO UPR JET AXIS/DEEPER MSTR CNVGC. SO OPTED TO GO NO HIER
THAN CHC POPS OVER THE W HALF OF THE CWA IN THE AFTN...WITH DRY WX
EXPECTED OVER THE E HALF CLOSER TO DEPARTING RDG/DRY AIR. ALTHOUGH
FOG MAY LINGER OVER THE CENTRAL WELL THRU THE MRNG WITH PERSISTENT
UPSLOPE SSE FLOW...RETURN OF MORE SUNSHINE IN THE AFTN WITH H85
TEMPS AS HI AS 10-12C SUG TEMPS WL RISE TO WELL ABV NORMAL. COOLER
CONDITIONS ARE LIKELY OVER THE W WHERE THERE WL BE MORE CLD COVER IN
THE AFTN...BUT SOME MRNG SUNSHINE/DOWNSLOPE S WIND WITH LESS FOG
STILL INDICATE A WARM DAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 431 PM EDT TUE OCT 16 2012
TO BEGIN THE LONG TERM...A DEEP TROF (500MB DEPTH PEAKS THU MORNING
AT 3.5 STANDARD DEVIATIONS FROM THE LONG TERM AVG) WILL BE OVER THE
MID AND UPPER MISSISSIPPI VALLEY. TROF THEN UNRAVELS QUICKLY AND
GETS KICKED NE BY BROAD TROF SETTLING INTO WRN NAMERICA. MEDIUM
RANGE GUIDANCE IS IN POOR AGREEMENT ON THE STRUCTURE/EVOLUTION OF
THE WRN TROF AND STRENGTH/TIMING/TRACKS OF SHORTWAVES EJECTING FROM
TROF. THE GFS RUN-TO-RUN CONSISTENCY FROM LATE WEEKEND INTO EARLY
NEXT WEEK IS IMPROVING WITH LATEST RUNS MORE AGGRESSIVE PUSHING
ENERGY E...FLATTENING DOWNSTREAM RIDGE OVER THE GREAT LAKES/ERN
CONUS AND SHIFTING RIDGE BACK TO THE W. THE ECMWF HAD SHOWN SOMEWHAT
BETTER CONSISTENCY IN DEPICTING A SLOWLY PROGRESSIVE WRN TROF AND A
MORE PRONOUNCED ERN RIDGE THRU EARLY NEXT WEEK. HOWEVER...THE 12Z
ECMWF HAS MADE A BIG SHIFT TOWARD THE GFS IDEA. THRU 12Z MON...THE
GLOBAL GEM/UKMET OFFER OTHER VARYING IDEAS ON THE WRN TROF...BUT
TEND TO LOOK A LITTLE MORE LIKE PREVIOUS ECMWF RUNS. ALL THIS LEADS
TO A VERY LOW CONFIDENCE FCST FOR THE LATTER HALF OF THE LONG TERM
WITH RESPECT TO BOTH TEMPS AND PCPN. GIVEN THE MODEL ISSUES...
TODAY`S LONG TERM FCST WON`T FAVOR ANY SOLUTION IN PARTICULAR THOUGH
IT WOULD SEEM THE 12Z GFS/12Z ECMWF MAY BE WHERE MEDIUM RANGE
GUIDANCE WILL BE HEADING IN UPCOMING RUNS. OVERALL...NEAR NORMAL
TEMPS LATE THIS WEEK SHOULD TREND ABOVE NORMAL BY LATE WEEKEND AND
THEN BEGIN TO FALL BACK CLOSER TO NORMAL. AFTER LINGERING SHRA
CHANCES LATE IN THE WORK WEEK WITH DEPARTING TROF...DEVELOPING GREAT
LAKES/ERN RIDGE SHOULD INITIALLY LEAD TO DRIER WEATHER OVER THE
WEEKEND BEFORE PCPN CHANCES RETURN MON/TUE.
BEGINNING WED NIGHT...TROF WILL BE APPROACHING MAX DEPTH AS 500MB
LOW CLOSES OFF IN THE VCNTY OF NE IA. SFC WAVE WILL DEVELOP/DEEPEN
AND ROTATE THRU ERN WI TOWARD NW WI/WRN UPPER MI OVERNIGHT.
AHEAD OF FRONT/SFC WAVE...WARM CONVEYOR PCPN WILL SWING ACROSS UPPER
MI. NICE DIRECTIONALLY DIFFLUENT UPPER LEVEL FLOW OVERTOP SHARPENING
850MB FRONT WILL AID THE PCPN. LIKELY/CATEGORICAL POPS SPREADING
ACROSS THE AREA APPEARS REASONABLE. CLOUDS/PCPN WILL HOLD MIN TEMPS
IN THE 40S...AND POSSIBLY AROUND 50 E.
WARM CONVEYOR PCPN SHOULD ROTATE OUT OF THE AREA THU...BUT DEEP
CYCLONIC FLOW AND INDICATIONS OF SHORTWAVE PIVOTING AROUND MID LEVEL
LOW TOWARD UPPER MI WILL WORK TO KEEP PCPN CHANCES OVER THE AREA
THRU THE DAY. ABUNDANT CLOUD COVER AND WEAK CAA WILL LIMIT DIURNAL
TEMP RISE. EXPECT HIGHS IN THE UPPER 40S TO MID 50S.
THU NIGHT/FRI...ENTIRE SYSTEM WEAKENS RATHER QUICKLY AND FOCUSED
PCPN SHOULD DIMINISH AS LOW/MID LEVEL WIND FIELDS WEAKEN
DRAMATICALLY. IN FACT...MUCH OF THE GUIDANCE SUGGESTS A TREND TOWARD
MOSTLY DRY LATER THU NIGHT INTO FRI. HOWEVER...WHILE ORGANIZED PCPN
AREAS WILL DIMINISH THU NIGHT...PROXIMITY OF THE CENTER OF WEAKENING
MID LEVEL LOW SUGGESTS MAINTAINING CHC/SLIGHT CHC POPS THU
NIGHT/FRI. MAY END UP BEING MORE OF A DRIZZLE SITUATION WITH PATCHY
-RA. DIURNAL TEMP SWING THU NIGHT/FRI SHOULD CONTINUE TO BE LIMITED
BY CLOUDS AND ALSO BY LITTLE TEMP ADV.
AS WEAKENING SYSTEM BEGINS TO ACCELERATE TO THE NE SAT...WILL OPT
FOR A DRY DAY. BEST SHOT FOR A DRY DAY WILL BE SUN AS AMPLIFYING
RIDGE AXIS DOWNSTREAM OF DEVELOPING WRN TROF SHIFTS ACROSS THE UPPER
LAKES. SUN WILL BE THE WARMEST DAY...WITH MID 50S E AND PERHAPS
AROUND 60F OVER THE W
AS MENTIONED ABOVE...THERE IS VERY LOW CONFIDENCE IN FCST FOR EARLY
NEXT WEEK. EXPECT A CHC OF PCPN AT SOME POINT SUN NIGHT INTO TUE AS
COLD FRONT SLIPS THRU THE AREA. THE 12Z ECMWF/GFS SUGGEST LIMITED
PCPN CHC THAT WILL BE CONFINED MAINLY TO MON OVER THE SCNTRL AND E.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 144 AM EDT WED OCT 17 2012
CONDITIONS WILL CONTINUE TO BE VFR THROUGH MOST OF THE NIGHT AT KCMX
AND KSAW...THEN EXPECT SOME FOG/LO CLD TO DVLP WITH NOCTURNAL
COOLING OF THE FAIRLY MOIST LLVLS UNDER THE DRYING ALF. THE BEST CHC
FOR IFR AND EVEN LIFR CONDITIONS WL BE AT SAW...WITH FAVORABLE
UPSLOPE SSE WIND. KIWD WILL HAVE ENOUGH HIGH CLOUDS TO PREVENT FOG
AND WILL STAY VFR THROUGH THE PERIOD UNTIL RAIN ARRIVES AND CAUSES
MVFR CIGS IN THE EVENING. ONSET OF DAYTIME HEATING/MIXING ON WED WL
BREAK UP ANY FOG/LO CLD THAT DEVELOPS AT KSAW AND KCMX WITH VFR
CONDITIONS CONTINUING THROUGH THE REST OF THE TAF PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 431 PM EDT TUE OCT 16 2012
EXPECT S WINDS UP TO 25-30 KTS OVER THE E HALF TO DIMINISH A BIT
TONIGHT WITH THE ARRIVAL OF A WEAKER PRES GRADIENT. SE WINDS UP TO
25 KTS WILL CONTINUE ON WED IN ADVANCE OF AN APPROACHING DEEP LO
PRES CENTER. THE STRONGEST WINDS WILL BE OVER THE E HALF AGAIN WHERE
THE TERRAIN TENDS TO ENHANCE THESE WINDS.
DEEPENING SFC LOW ROTATING NW THRU NRN WI WED NIGHT WILL RESULT IN
AN INCREASE IN E TO SE WINDS ACROSS LAKE SUPERIOR. NOT OUT OF THE
QUESTION THAT SOME GALE FORCE GUSTS COULD DEVELOP LATE IN THE NIGHT
FROM AROUND WHITEFISH PT TO AROUND ISLE ROYALE. WINDS WILL THEN
DIMINISH DURING THE DAY THU AS LOW PRES WEAKENS. BY THU AFTN...WINDS
SHOULD BE UNDER 15KT OVER WRN LAKE SUPERIOR AND DOWN TO 15 TO 25KT
OVER CNTRL AND ERN LAKE SUPERIOR. BEYOND THU...NO SIGNIFICANT
WEATHER SYSTEMS ARE EXPECTED TO AFFECT THE UPPER LAKES THRU THE
WEEKEND. IN FACT...WEAK PRES GRADIENT MAY LEAD TO A PERIOD OF LIGHT
WINDS UNDER 15KT OVER MUCH OF LAKE SUPERIOR FRI THRU SUN.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...ROLFSON
AVIATION...07
MARINE...KC/ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
352 AM CDT WED OCT 17 2012
.DISCUSSION...
PRETTY VIGOROUS SYSTEM TO AFFECT WX ACROSS AREA FOR NEXT COUPLE OF
DAYS WITH SOME NEEDED PCPN AND A LOT OF WIND. STRENGTH OF
DEEPENING UPPER TROF DROPPING OUT OF SASK EVIDENCE BY 500 MB
HEIGHT FALLS OF AS MUCH AS 150 M IN GGW THIS EVENING. THE UPPER
TROF PROGGED BY MODELS TO CONTINUE TO WIND UP AS IT DROPS SE
ACROSS AREA WITH 140 KT UPPER JET PLOWING ACROSS THE PACIFIC NW
INTO THE CENTRL PLAINS.
AHEAD OF THIS FEATURE WV IMAGERY SHOWING A NICE VORT LIFTING ENE
ACROSS SODAK...CURRENTLY AROUND KHON. RADAR MOSAIC SHOWING A NICE
AREA OF SHWRS ACROSS MUCH OF NE/EC SODAK AHEAD OF THIS FEATURE.
NARROW FATHER FAST MOVING BAND OF SHOWERS SOUTH OF THIS AREA IS
MOVING RAPIDLY ACROSS SC MN. HRRR AND LOCAL WRF KEEP MAIN AREA OF
SHOWERS THIS MORNING ACROSS WC INTO CENTRAL MN ASSOCIATED WITH
SODAK VORT...AND THIS SEEMS REASONABLE GIVEN RADAR TRENDS. ANOTHER
AREA OF SHOWERS DEVELOPS ACROSS IA/SE MN INTO WI AHEAD OF CDFNT
LATER THIS MRNG INTO THE AFTN. LOWERED POPS A BIT ACROSS S AREAS
AS WELL AS QPF...KEEPING LIKELY POPS MORE INTO CNTL MN.
RETAINED WIND ADVY SW OF THE MN FOR LT MRNG INTO EARLY EVENING.
STRONGEST CAA AND SURFACE PRESSURE RISES REMAIN S OF THAT
AREA...MORE ACROSS SODAK/NEB INTO IA BUT SOME OF THE HIER TERRAIN
SHUD SEE SOME SUSTAINED WINDS ARND 30 MPH. SHARPEST FALL IN
DEWPOINTS AND RH ALSO SOUTH OF OUR AREA SO WILL NOT BE ISSUING ANY
FIRE WX HEADLINES...BUT WILL ADDRESS THE STRONG WINDS IN A HEADLINE.
AS UPPER LOW BEGINS TO WIND UP ON THURSDAY INTO THURS NITE ACROSS S
MN/N IA STRONG ISENTROPIC LIFT SETS IN A STRONG WAA PATTERN NORTH
OF THE LOW WHICH SHUD BRING IN LIKELY POPS ESP ACROSS WESTERN
HALF OF CWA. DIFFERENCES IN MODEL PLACEMENT OF SFC LOW...BUT THEY
ALL TIGHTEN PRESSURE GRADIENT MAINLY ACROSS W MN DURING THE DAY
THURSDAY WHICH MAY REQUIRE ANOTHER WIND ADVY.
SOME LINGERING PCPN INTO FRIDAY...THEN WARMING AND DRYING TREND
FOR THE WEEKEND AS DEEP LOW PRESSURE GETS KICKED OUT AND SW FLOW
RETURNS. SHUD SEE HIGHS NEAR 60 SW AREAS ON SATURDAY AND INTO THE
60S ACROSS THE AREA FOR SUNDAY.
&&
.AVIATION.../06Z TAF ISSUANCE/
NO ISSUES TO START THE TAF BUT WILL LOOK FOR CONDITIONS TO
DETERIORATE BY 12Z IN WESTERN MINNESOTA THEN GRADUALLY TRANSITION
TO EASTERN MINNESOTA AND WESTERN WISCONSIN AS A POTENT COLD FRONT
APPROACHES FROM THE WEST. FEW BANDS OF RAIN...SOME OF WHICH MAY
CONTAIN MVFR CEILINGS...WILL CROSS THROUGH THE AREA DURING THE
FIRST HALF OF THE TAF PERIOD. CONDITIONS LOOK TO IMPROVE BY AROUND
18Z AS MODELS DEPICT A DRY SLOT WITHIN THE ROTATING LOW PRESSURE
SYSTEM. THIS DRY SLOT SHOULD ALLOW FOR A BRIEF DRYING-OUT PERIOD
ALONG WITH IMPROVED FLIGHT CONDITIONS. THE TIMING OF IT IS HIGHLY
PROBLEMATIC SO HAVE TRIED TO ADVERTISE IT WITH NO MENTION OF
VCSH/-RA IN THE MID-TO-LATE AFTN HOURS. ONCE THE SYSTEM MOVES FAR
ENOUGH INTO THE GREAT LAKES...A PRECIP SHIELD ON THE BACKSIDE OF
THE SYSTEM WILL PUSH THROUGH THE AREA MAINLY AFTER 18/00Z. HAVE
ADVERTISED MVFR CIGS AFTER 18/00Z IN ANTICIPATION OF A MORE
STRATIFORM TYPE OF PRECIP...BUT MODELS ARE A BIT MORE OPTIMISTIC
AND KEEP THINGS VFR. THE OTHER MAIN CONCERN WILL BE SHIFTING THEN
GUSTY WINDS WITH THE COLD FROPA. WINDS WILL QUICKLY GO SE-SW-W
LATE MORNING INTO THE EARLY AFTN AS THE FRONT PUSHES THROUGH. ONCE
IT PASSES...SUSTAINED SPEEDS WILL INCREASE GENERALLY TO THE 15-20
KT RANGE WITH GUSTS 25-30KT...THOUGH WESTERN MN WILL LIKELY SEE
20-25KT WITH GUSTS UPWARDS OF 35 KT OR POSSIBLY EVEN HIGHER.
KMSP...NO ISSUES TO START WITH RELATIVELY LIGHT SE WINDS. CLOSE TO
SUNRISE...WINDS WILL SHIFT AROUND TO SW AND INCREASE TO NEAR 10 KT
AS A COLD FRONT APPROACHES. LIGHT RAIN SHOWERS WILL MOVE ACROSS
THE FIELD AROUND DAYBREAK AND PERSIST THROUGH LATE MRNG. MAY BE A
FEW PERIODS OF MVFR CIGS...BUT GENERALLY CONDITIONS WILL REMAIN
VFR DURG THE RAIN. RAIN WILL STEADILY SHIFT OFF TO THE EAST...
THOUGH THERE MAY BE A FEW LINGERING SHOWERS DURING THE MIDDAY
PERIOD. THE DRY SLOT OF THIS SYSTEM LOOKS TO MOVE OVER THE AREA
DURING THE AFTERNOON HOURS...BUT WIND SPEEDS WILL ALSO KICK UP AT
THIS POINT TO ARND 15 KT WITH GUSTS TO ARND 25 KT...POSSIBLY EVEN
HIGHER AT TIMES. SPEEDS WILL SETTLE DOWN BY SUNSET BUT ANOTHER
ROUND OF RAIN SHOWERS CAN BE EXPECTED LATE TONIGHT INTO EARLY
THURSDAY MRNG. AM EXPECTING A MORE PESSIMISTIC RUN OF CEILINGS
LATE WED NIGHT/EARLY THU MORNING THAN MODELS.
/OUTLOOK FOR KMSP/
THU...MVFR CIGS WITH MVFR VSBY DURING SHRA. IFR CIGS POSSIBLE.
W/NW WINDS 15 TO 25 KT WITH GUSTS ABOVE 30 KTS.
FRI...MVFR CIGS...SCT -SHRA. NW WINDS 10 KTS.
SAT...VFR. S WINDS 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND ADVISORY FROM 10 AM THIS MORNING TO 7 PM CDT THIS EVENING
FOR BROWN-LAC QUI PARLE-MARTIN-REDWOOD-WATONWAN-YELLOW
MEDICINE.
WI...NONE.
&&
$$
BAP/DWE
AREA FORECAST DISCUSSION
NWS BUFFALO NY
115 AM EDT WED OCT 17 2012
.SYNOPSIS...
MAINLY CLEAR SKIES THIS EVENING WILL GIVE-WAY TO INCREASING MID
LEVEL CLOUDS WHICH ARE ASSOCIATED WITH A WARM FRONT. EXPECT
MAINLY DRY CONDITIONS WEDNESDAY AND WARMER WITH AFTERNOON HIGH
TEMPERATURES CLIMBING INTO THE 60S...AND A FEW LOWER 70S. OUR AREA
WILL REMAIN ON THE MILD SIDE INTO THURSDAY...BEFORE A GUSTY COLD
FRONT AND SHOWERS CROSSES THE AREA THURSDAY AFTERNOON AND EVENING.
&&
.NEAR TERM /THROUGH TODAY/...
IR SATELLITE IMAGERY SHOWS MUCH OF THE LAKE EFFECT CLOUDS HAVE
DISSIPATED BY LATE EVENING...EXCEPT FOR A SMALL AREA LINGERING
EAST OF LAKE ONTARIO. THESE CLOUDS SHOULD ALSO DISSIPATE AS THE
NIGHT GOES ON. THIS CLEARING HAS ALLOWED TEMPERATURES TO DROP
RATHER QUICKLY DURING THE EVENING HOURS...SO HAVE NUDGED THE LOW
TEMPERATURE FORECAST A TAD LOWER. LOWS WILL LARGELY BE REACHED
TOWARD MIDNIGHT...BUT THEN TEMPERATURES SHOULD LEVEL OFF AS MID-
HIGH CLOUDS APPROACHING FROM THE SOUTHWEST SPREAD ACROSS THE
REGION. THESE CLOUDS ARE ASSOCIATED WITH A WARM FRONT...AND CAN
ALREADY BE SEEN ACROSS LAKE ERIE LATE THIS EVENING.
LOWS SHOULD RANGE FROM THE LOWER TO MID 30S IN THE TYPICALLY
COLDER INTERIOR VALLEYS...TO AROUND 40 CLOSER TO THE LAKE SHORES.
A HIGH PRESSURE RIDGE WILL EXTEND FROM THE APPALACHIANS AND INTO
WESTERN NEW YORK OVERNIGHT. MEANWHILE...A WARM FRONT WILL BRUSH WESTERN
PORTIONS OF NEW YORK TOWARDS DAWN...BUT WITH DEEP MOISTURE ALSO
LINGERING TO OUR WEST...EXPECT THE BULK OF THE REGION TO REMAIN
DRY LATE OVERNIGHT AND TOMORROW WITH THE WARM FRONT. THE HRRR IS
COMING IN RIGHT IN LINE WITH OTHER MODEL GUIDANCE...SUGGESTING
SOME LIGHT SHOWERS OR SPRINKLES CLIPPING FAR NW PORTIONS OF THE
STATE EARLY WEDNESDAY MORNING.
WITH THE WARM FRONT LIFTING INTO CANADA WEDNESDAY...OUR REGION WILL
FALL INTO THE WARM SECTOR. TEMPERATURES ALOFT AT 850 HPA WILL CLIMB
TOWARDS +10 TO +12C ACROSS OUR REGION. HOWEVER WE MIGHT NOT MIX UP TO
THIS LEVEL...AND WILL USE 925 HPA TEMPERATURES INSTEAD TO FORECAST
HIGHS FOR WEDNESDAY. AT 925 HPA...WE WARM TO +17C TO THE WEST AND
+13C ACROSS THE SOUTHERN GENESEE VALLEY AND EASTERN NORTH COUNTRY.
MIXING THESE TEMPERATURE VALUES DOWN TO THE SURFACE...AND WITH A
MIX OF CLOUDS AND SUNSHINE WE SHOULD HAVE HIGHS IN THE 60S...WITH
A FEW DOWNSLOPING AREAS OF THE GENESEE VALLEY WESTWARD REACHING
INTO THE LOWER 70S.
WINDS WILL BECOME SOUTHERLY TOMORROW WITH HIGH PRESSURE TO OUR
EAST...AND LOW HANGING WELL TO OUR WEST OVER THE NORTHERN PLAINS.
THE PRESSURE GRADIENT DOES INCREASE LATE IN THE DAY TO THE
WEST...AND SOME AFTERNOON LIGHT BREEZES WILL BE LIKELY ACROSS WNY.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
DRY WEATHER SHOULD BE MAINTAINED WEDNESDAY NIGHT AHEAD OF THE
APPROACHING SLOW MOVING COLD FRONT. WARM AIR ADVECTION REGIME ON A
40 KNOT SOUTHERLY LOW LEVEL JET WILL ALLOW TEMPERATURES TO REMAIN
MILD...AND MAY EVEN RISE SLIGHTLY OVERNIGHT AS CLOUD COVER SPREADS
ACROSS THE AREA.
SOUTHERLY LOW LEVEL JET WILL CONTINUE TO STRENGTHEN AHEAD OF THE
FRONT THURSDAY...REACHING AT LEAST 50 KNOTS. WINDY CONDITIONS WILL
LIKELY DEVELOP...ESPECIALLY IF ANY SUNSHINE CAN DEVELOP AND AID
MIXING PROCESS. MODEL SOUNDINGS SUGGEST THE POTENTIAL FOR WIND GUSTS
TO 45 MPH AND POSSIBLY HIGHER FOR FAVORED DOWNSLOPE AREAS...THE
HIGHER TERRAIN OF THE SOUTHERN TIER AND FINGER LAKES. THE FRONT
LOOKS TO PUSH INTO WESTERN NEW YORK BY LATE IN THE DAY...ACCOMPANIED
BY A BAND OF SHOWERS AS A WELL DEFINED THETA E RIDGE LOOKS TO
DEVELOP ALONG AND JUST AHEAD OF THE FRONT. UPPER LEVEL SUPPORT LOOKS
DECENT UNDERNEATH LEFT EXIT REGION OF A 110 KNOT PLUS UPPER LEVEL
JET STREAK. TEMPERATURES LOOK MILD AHEAD OF THE FRONT WITH HIGHS IN
THE MID 60S TO LOWER 70S....ALTHOUGH COULD BE WARMER WITH ADDITIONAL
SUNSHINE AND SLOWER MOVEMENT OF THE COLD FRONT.
THE COLD FRONT AND BAND OF SHOWERS WILL SLOWLY WORK INTO EASTERN
SECTIONS THURSDAY NIGHT. A SHARP MID LEVEL DRY SLOT SURGING INTO THE
REGION IN WAKE OF THE FRONT SHOULD END THE PRECIPITATION FROM WEST
TO EAST. THERE LOOKS TO BE A BREAK IN THE PRECIPITATION FOR A GOOD
PART OF FRIDAY IN THE WAKE OF THE FRONT AND AHEAD OF THE SLOWLY
EVOLVING UPPER LEVEL LOW ACROSS THE NATIONS HEARTLAND. WESTERN
SECTIONS WILL HAVE THE BETTER CHANCES FOR SEEING PRECIPITATION
ASSOCIATED WITH THE UPPER LOW LATE IN THE DAY FRIDAY.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
MODEL DISCREPANCIES CONTINUE TO EXIST DURING THE PERIOD...ALTHOUGH
THE GENERAL MODEL IDEA TO SUGGEST A SLOW MOVING UPPER LOW WILL BE
PASSING ACROSS THE AREA OVER THE WEEKEND. THE SPEED/TIMING OF THE
UPPER LEVEL CIRCULATION IS CONTINUED TO BE HANDLE DIFFERENTLY BY THE
MEDIUM RANGE MODELS. THE 12Z GFS/CMC SUGGESTING A MORE PROGRESSIVE
SOLUTION WHICH LIFTS THE LOW OUT WITH A RETURN TO A MORE ZONAL FLOW
REGIME RATHER QUICKLY...WHILE THE ECMWF MAINTAINS A SLOWER AND MORE
SOUTHERN SOLUTION. AT THIS POINT...WOULD PREFER TO LEAN TOWARD THE
SLOWER ECMWF BASED A GENERAL BLOCKING PATTERN SEEN SOUTH OF
NEWFOUNDLAND DURING THIS TIME FRAME. THE SLOWER TIMING OF THE UPPER
LOW AND ASSOCIATED COLD POOL ALOFT WOULD FAVOR BETTER CHANCES FOR
SHOWERS...ESPECIALLY EARLY IN THE WEEKEND. WITH THE COLD POOL
OVERHEARD FOR THE WEEKEND...HIGH TEMPERATURES WILL LIKELY STRUGGLE
TO WARM OUT OF THE MIDDLE TO UPPER 50S BOTH WEEKEND DAYS...WITH
OVERNIGHT LOWS GENERALLY HOVERING IN THE LOWER TO MIDDLE 40S. BY
EARLY NEXT WEEK...ECMWF SUGGESTS THE UPPER LOW WILL FINALLY EXIT AS
THE NEXT UPPER TROUGH STARTS DIGGING ACROSS THE WESTERN CONUS AND
THE RIDGING SOUTH OF NEWFOUNDLAND BREAKS DOWN. THIS AGREES WELL WITH
THE GFS/CMC MODEL SOLUTIONS AND THEREFORE HAVE MAINTAINED DRY
WEATHER FOR THE REMAINDER OF THE PERIOD...WITH A GRADUAL WARMING
TREND.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
A WARM FRONT DRAPED ACROSS THE CENTRAL GREAT LAKES WILL LIFT
NORTHEAST ACROSS THE AREA TODAY...WITH FAIRLY WIDESPREAD MID AND
HIGH LEVEL CLOUDS PRECEDING AND ACCOMPANYING ITS PASSAGE. A FEW
SPRINKLES OR VERY LIGHT SHOWERS WILL ALSO BE POSSIBLE ACROSS FAR
WESTERN NEW YORK THIS MORNING...HOWEVER THESE SHOULD HAVE NO
IMPACT ON AVIATION OPERATIONS WITH ALL LOCATIONS REMAINING VFR.
TONIGHT...VFR CONDITIONS WILL CONTINUE WITH SKIES CLEARING OUT
SOMEWHAT BEHIND THE DEPARTING FRONT. OVERNIGHT...A DEVELOPING
SOUTHERLY LOW LEVEL JET WILL LIKELY BRING SOME LOW LEVEL WIND
SHEAR CONCERNS...HOWEVER THESE WILL FALL AFTER THE END OF THE
CURRENT TAF PERIOD.
OUTLOOK...
THURSDAY AND THURSDAY NIGHT...DETERIORATING TO MVFR WITH A PERIOD
OF RAIN SHOWERS THURSDAY AFTERNOON AND NIGHT.
FRIDAY...MAINLY VFR WITH A CHANCE OF RAIN SHOWERS.
SATURDAY AND SUNDAY...VFR/MVFR WITH SCATTERED SHOWERS.
&&
.MARINE...
HIGH PRESSURE OVER THE OHIO VALLEY WILL CONTINUE TO RIDGE NORTHWARD
ACROSS THE EASTERN GREAT LAKES THIS EVENING.
A WARM FRONT WILL LIFT ACROSS THE LAKES WEDNESDAY BUT WINDS AND
WAVES SHOULD REMAIN BELOW SCA LEVELS. WEDNESDAY NIGHT UNDER A
CONTINUED SOUTHERLY FLOW WAVES WILL START TO BUILD TOWARDS 4 FEET ON
THE NORTHEASTERN PORTION OF LAKE ONTARIO.
ON THURSDAY WINDS WILL INCREASE WITH SCA LIKELY FOR BOTH LAKES AND
POSSIBLY SOME OF OUR TWO RIVERS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...THOMAS
NEAR TERM...APFFEL/THOMAS
SHORT TERM...TMA
LONG TERM...TMA
AVIATION...JJR
MARINE...APFFEL/THOMAS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
448 AM CDT WED OCT 17 2012
.SHORT TERM...NOW THROUGH THURSDAY AFTERNOON...
THE MAIN FORECAST PROBLEM THIS MORNING DEALS WITH THE COMMA HEAD
PRECIPITATION SLIDING SOUTHEAST ACROSS THE WESTERN PORTION OF
NORTH DAKOTA IN 4 AM CDT RADAR AND SATELLITE IMAGERY.
A DRASTIC INCREASE IN WIND SPEEDS IS COINCIDENT WITH THE FRONT
EDGE OF COMMA HEAD RAIN BASED ON CURRENT OBSERVATIONS...SO WIND
GRIDS WERE GENERALLY TIMED USING THAT BOUNDARY. THE GREATEST
UNCERTAINTY WITH WINDS AT THIS POINT IS ACROSS THE NORTH WHERE
WINDS MAY NOT QUITE REACH HIGH WIND CRITERIA ON THURSDAY.
VERY SHORT TERM PRECIPITATION IS BASED ON 06 UTC HRRR SIMULATED
REFLECTIVITY AND CURRENT TRENDS...BUT 00 UTC CONSENSUS BLEND WAS
USED FOR PRECIPITATION CHANCES AFTER 12 UTC THIS MORNING.
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...
THE MAIN FORECAST ISSUES IN THE LONG TERM WILL BE THE TIMING OF
SEVERAL SHORT WAVE TROUGHS IN THE DEVELOPING SOUTHWEST FLOW...AND
ASSOCIATED PRECIP CHANCES. ON THURSDAY NIGHT...LIGHT PRECIPITATION
WILL BE LINGERING FROM THE JAMES RIVER VALLEY THROUGH THE TURTLE
MOUNTAINS. WARMER AIR ALOFT WILL WRAP BACK INTO THE AREA BEHIND
THE EXITING SURFACE LOW. HOWEVER...SURFACE TEMPS ARE EXPECTED TO
REMAIN ABOVE FREEZING AND PRECLUDE ANY FREEZING RAIN. WINDS WILL
STILL BE QUITE GUSTY DURING THE EVENING HOURS SOUTHEAST...AND
ADVISORY HEADLINES MAY BE NEEDED BEYOND THE CURRENT HIGH WIND
WARNING. UPPER RIDGING WILL RESULT IN A TEMPORARY WARM-UP FRIDAY
INTO SATURDAY...FOLLOWED BY COOLER TEMPS SUNDAY INTO EARLY NEXT
WEEK. BASED ON A GFS/ECMWF CONSENSUS...SATURDAY NIGHT IS FAVORED
FOR RAIN OR A RAIN/SNOW MIX. ALSO MAINTAINED LOW POPS SUNDAY NIGHT
THROUGH TUESDAY.
&
.AVIATION...
EXPECT PERIODS OF MVFR CIGS AND SHOWERS THIS MORNING...LIKELY
LINGERING INTO THE AFTERNOON AT KMOT AND POSSIBLY KJMS. LOWER
CLOUDS MAY ALSO IMPACT KISN/KBIS LATER TONIGHT. WINDS ARE ALREADY
BECOMING QUITE STRONG ACROSS WESTERN NORTH DAKOTA...AND WILL
CONTINUE TO INCREASE THROUGH THE MORNING AND AFTERNOON...LIKELY
REACHING GUSTS AROUND 45-50 KTS. WINDS WILL DIMINISH SLIGHTLY
LATER TONIGHT.
&&
.FIRE WEATHER...
A REVIEW OF TWO SOUTH DAKOTA CASES WITH CONDITIONS SIMILAR TO
THOSE FORECAST TODAY AND TOMORROW SUGGESTS THAT RELATIVE
HUMIDITIES BELOW 40 PERCENT WITH WINDS GUSTING TO AROUND 60 MPH
WILL RESULT IN CRITICAL FIRE GROWTH IF ONE SHOULD IGNITE.
COORDINATION WITH STATE AND FEDERAL FIRE OFFICIALS SUGGESTS THAT
RELATIVE HUMIDITIES WOULD HAVE TO BE EVEN HIGHER TO KEEP FIRES
FROM UNCONTROLLABLE SPREADING...SO 50 PERCENT WAS GENERALLY USED AS
THE DECIDING FACTOR FOR WHO SHOULD BE IN A RED FLAG WARNING TODAY.
USING THE SAME METHODOLOGY...THURSDAY WOULD ALSO REQUIRE A RED
FLAG WARNING FROM NORTHWEST THROUGH SOUTH CENTRAL NORTH DAKOTA.
THERE IS UNCERTAINTY WITH REGARD TO HOW MUCH RAINFALL WILL OCCUR
TODAY...AND ITS OVERALL IMPACT ON DRY FUELS...BUT ANOTHER RED
FLAG WARNING MAY BE NECESSARY THURSDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 7 PM CDT /6 PM MDT/ THURSDAY FOR
NDZ001>005-009>013-017>023-025-031>037-040>048-050-051.
RED FLAG WARNING FROM 9 AM CDT /8 AM MDT/ THIS MORNING TO 10 PM
CDT /9 PM MDT/ THIS EVENING FOR NDZ001-009-017>021-031>036-
040>048-050-051.
&&
$$
SHORT TERM/FIRE WEATHER...SCHECK
LONG TERM/AVIATION...KINNEY
AREA FORECAST DISCUSSION
NWS BISMARCK ND
112 AM CDT WED OCT 17 2012
.DISCUSSION...
THE MAIN FORECAST PROBLEM THIS MORNING DEALS WITH THE COMMA HEAD
PRECIPITATION SLIDING SOUTHEAST ACROSS THE WESTERN PORTION OF
NORTH DAKOTA THIS MORNING. COLLABORATION WITH SURROUNDING OFFICES
HAS ALLOWED FOR CONSIDERABLE DEVIATION FROM THE PREVIOUS FORECAST.
ALL CHANGES ARE BASED ON 12 AM CDT SATELLITE AND RADAR DATA...AS
WELL AS 02 UTC HRRR SIMULATED REFLECTIVITY.
A 51 KNOT WIND GUST NEAR GLASGOW IN THE PAST COUPLE HOURS
SUGGESTS THAT THE WIND FORECAST FOR WESTERN NORTH DAKOTA IS ON
TRACK.
&&
.AVIATION...
BIGGEST CONCERN IN THE EXTENDED WILL BE TIMING OF STRONG WINDS
BEHIND COLD FRONT IN NORTHEAST MONTANA. CEILING REMAIN VFR EVEN
WELL BEHIND THE SYSTEM IN WESTERN SASKATCHEWAN. HOWEVER SOME MVFR
CEILINGS ARE POSSIBLE AS LOW DEEPENS OVERNIGHT.
&&
.FIRE WEATHER...
RED FLAG WARNING WEDNESDAY WHERE THE WINDS WERE
FORECAST 40 MPH OR MORE AND RELATIVE HUMIDITY 40 PERCENT OR LESS.
HIGH WINDS WILL OVERRIDE THE RELATIVE HUMIDITY WITH THE ABUNDANT
DRY VEGETATION. RAINFALL THIS AFTERNOON AND TONIGHT IS NOT
EXPECTED TO SIGNIFICANTLY WET THE AREA WITHIN THE RED FLAG
WARNING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 7 PM CDT /6 PM MDT/ THURSDAY FOR
NDZ001>003-009>011-017>021-031>034-040>045.
RED FLAG WARNING FROM 9 AM CDT /8 AM MDT/ THIS MORNING TO 10 PM
CDT /9 PM MDT/ THIS EVENING FOR NDZ001-009-017>021-031>036-
040>048-050-051.
HIGH WIND WARNING UNTIL 7 PM CDT THURSDAY FOR NDZ004-005-012-013-
022-023-025-035>037-046>048-050-051.
&&
$$
DISCUSSION...SCHECK
AVIATION...HW
FIRE WEATHER...JV
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
426 AM EDT WED OCT 17 2012
.SYNOPSIS...
HIGH PRESSURE SLIPS EAST WEDNESDAY. COLD FRONT BRINGS GOOD CHANCE
FOR SHOWERS THURSDAY INTO FRIDAY. THE PARENT DEEP LOW PRESSURE
SYSTEM APPROACHES FROM THE NORTHWEST FRIDAY NIGHT INTO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
ZONAL FLOW WILL BECOME INCREASINGLY SOUTHWESTERLY TODAY IN ADVANCE
OF A CLOSED UPPER LOW DIGGING SOUTHEASTWARD ACROSS THE UPPER
MIDWEST. AN EMBEDDED S/W TROUGH IN THE MEAN FLOW WILL BRUSH BY THE
AREA TO THE NORTH/NORTHWEST THIS MORNING. NO PRECIP IS EXPECTED WITH
THIS FEATURE BUT WILL RESULT IN INCREASED CLOUD COVER...PARTICULARLY
DURING THE MORNING HOURS AND ACROSS THE SE OHIO ZONES. INHERITED MAX
TEMPS GENERALLY IN THE MID/UPPER 70S LOWLANDS LOOK GOOD WITH ONLY A
COUPLE MINOR TWEAKS.
WED EVENING AND OVERNIGHT THE UPPER LOW WILL BE CONTINUING TO
PROGRESS SE-WARD...ESSENTIALLY LOCATED ROUGHLY OVER SOUTHERN MN BY
12Z THU. RUN TO RUN NAM/GFS COMPS SHOW GENERAL CONSISTENCY WITH ITS
TRACK...BUT BOTH SHOW SLIGHT DECREASE IN STRENGTH. ATTENDANT SFC LOW
WILL BE ROUGHLY OVER WISCONSIN WITH THE COLD FRONT EXTENDING
SOUTHEASTWARD. STRONG FORCING FOR ASCENT MOVES OVER THE FORECAST
AREA AFTER 06Z ALONG WITH GOOD DYNAMICS...INCLUDING MIDLEVEL
DIFFLUENT FLOW...GOOD POTENTIAL VORT ADVECTION...AS WELL AS DECENT
LLVL WARM ADVECTION AND A STRONG 850MB JET LIFTING NE-WARD ACROSS
EASTERN KY PRIOR TO FRONT/S ARRIVAL. DESPITE ALL THIS...DRY LOW
LEVELS WILL BE IN PLACE...WITH GOOD LLVL MOISTURE ARRIVING POST-FRONT.
850MB AND 700MB FLOW WILL BE PARALLEL TO GENERALLY VEERED FROM THE
ORIENTATION OF THE SFC FRONT WHICH WOULD USUALLY BE A PRECURSOR FOR
A PRE-FRONTAL PRECIP REGIME. ALL THIS TO SAY THAT THE MAIN PRECIP
SHOULD BE ALONG AND POST-FRONTAL IN A RELATIVELY THIN BAND GENERATED
MAINLY BY FRONTO-G FORCING. BOTH THE LATEST NAM AND SREF DEPICT THE
SFC FRONT JUST ENTERING THE WESTERN KY ZONES AT 12Z...WITH THE GFS
JUST SLIGHTLY SLOWER. WITH THIS IN MIND...INHERITED POP GRIDS WHICH
BRING PRECIP INTO THE WESTERN KY ZONES AROUND 09Z WITH THE BULK OF
THE PRECIP ARRIVING NEAR AND AFTER 12Z THU STILL LOOK REASONABLE
WITH ONLY MINOR ADJUSTMENTS. FINALLY...WITH STRONG LLVL SOUTHWEST
FLOW AND WARM ADVECTION...CONTINUED PREV FCST OF GOING WELL ABOVE
GUIDANCE ON OVERNIGHT LOWS IN THE MID/UPPER 50S LOWLANDS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
THE NAM/CMC/GFS/ECMWF ARE IN AGREEMENT WITH THE TIMING OF
CONVECTION ASSOCIATED WITH APPROACHING COLD FRONT OVER SOUTHEAST
OH BY 12Z THURSDAY. HOWEVER...THERE ARE INTENSITY DIFFERENCES IN
QPF FIELDS...AS WELL AS IN THE UPPER LEVEL SUPPORT. THE GFS HAS
STRONGER MID LEVEL FORCING ACROSS THE OH RIVER...WHILE THE NAM
WEAKENS ITS FORCING. NEVERTHELESS...BELIEVE IN PREVIOUS FORECAST
BRINGING HIGH CATEGORICAL POPS INTO SOUTHEAST OH BY 12Z...DECREASING
TO LIKELY AS THE FRONT SWEEPS EAST INTO THE AFTERNOON HOURS. H850
WINDS AHEAD OF THE FRONT ARE BETWEEN 55-60 KNOTS IN THE WARM
SECTOR. DEWPOINTS WILL INCREASE INTO THE LOWER 50S UNDER DEEP
SOUTH SOUTHWEST FLOW...DESPITE OF AFTERNOON MIXING.
HOWEVER...PWATS LOOKS RATHER LOW BARELY OVER ONE INCH.
VERY WEAK LAYERED CAPE...BUT DEEP LAYERED SHEAR EXCEEDING 55
KNOTS...STORM RELATIVE HELICITY EXCEEDING 300 M2/S2...AND BOUNDARY
LAYER CONVERGENCE ALONG THE FRONT CALLS FOR A DYNAMIC ENVIRONMENT
CAPABLE TO PRODUCE STORMS. KEPT STORM MENTION WITH LIKELY POPS
DECREASING IN COVERAGE AS THE FRONT MOVE EAST THURSDAY AFTERNOON.
SEVERE STORMS ARE NOT ANTICIPATED AT THIS TIME...STRONG GUSTY FLOW
ARE WORTH TO BE MENTIONED IN THE HWO.
STRONG GUSTY WINDS CAN MIX DOWN TO SFC ALONG FRONTAL
CONVECTION...AND CAN BE POSSIBLE ALSO OVER THE HIGHER ELEVATIONS.
KEPT SFC FRONT EXITING EASTERN MOUNTAINS BY 21Z..IF NOT A LITTLE
SOONER. EXPECT DRY SLOT TO PRODUCE SOME BREAKS IN THE CLOUDS
MAINLY SOUTH AND CENTRAL SECTIONS OF OUR CWA.
THIS COLD FRONT...EXTENDS NORTHWEST AS A OCCLUDED FRONT INTO THE
PARENT DEEP LOW PRESSURE SYSTEM OVER THE GREAT LAKES. SOME
DIFFERENCES NOTED IN THE H5 LOW CENTER...WITH THE NAM SHOWING IT
OVER THE OH VALLEY...THE GFS OVER THE GREAT LAKES...AS WELL AS THE
ECMWF AND CMC. THEREFORE...PER CONSENSUS...EXPECT LOW PRESSURE
TO APPROACH OUR AREA FROM THE NORTHWEST...BUT LIFT NORTHEAST
FRIDAY NIGHT. RAP AROUND MOISTURE BEHIND THE DEPARTURE LOW WILL
BRING CHANCES OF STRATIFORM RAIN ACROSS THE NORTHERN PORTIONS OF
THE AREA FRIDAY...INTO EARLY SATURDAY MORNING...PER GFS/ECMWF/CMC
CONSENSUS.
KEPT WIND GUSTS 20-30 KNOTS DO TO CAA AND EFFICIENT MOMENTUM
TRANSFER AS SEEN IN INVERTED V FEATURE IN BUFKIT SOUNDING FRIDAY.
WENT A DEGREE OR TWO LOWER THAN MAV/MET GUIDANCE PER UNCERTAINTY
OF CLOUD COVER...GENERALLY UPPER 60S LOWLANDS...RANGING INTO THE
MID 50S HIGHEST ELEVATIONS...FOR THURSDAY. EXPECT A COOLER TREND
THURSDAY NIGHT AND FRIDAY UNDER CAA...AND CLOUD COVER.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
STILL SOME ISSUES WITH MODEL AGREEMENT IN THE LONG TERM PERIOD IN
TERMS OF TIMING AND PATH OF EXITING LOW PRESSURE. GFS IS STILL
FASTER AND FARTHER TO THE NORTH WITH THE UPPER LOW THAN THE ECMWF.
BUT REGARDLESS...A GRADUAL DRYING TREND IS EXPECTED TO BEGIN ON
SATURDAY AS THE UPPER LOW GRADUALLY PUSHES EAST...AND A RIDGE OF
HIGH PRESSURE GRADUALLY STARTS TO BUILD IN FOR THE BEGINNING OF NEXT
WEEK. DID START TO BUMP TEMPERATURES UP A BIT FROM PREVIOUS
FORECAST...AND DRY OUT FORECAST FOR LATE THIS WEEK/EARLY NEXT WEEK.
SOME ISSUES CONCERNING THE TIMING OF NEXT SYSTEM...PROGGED TO ENTER
CWA BY MID WEEK...BUT FOR NOW...MAINTAINED A DRY FORECAST INTO
PERIOD DUE TO UNCERTAINTY.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
06Z WEDNESDAY THRU 06Z THURSDAY...
HIGH CIRRUS CURRENTLY OVERSPREADING THE AREA. STILL EXPECTING LIFR
FOG IN SHELTERED MOUNTAIN RIVER VALLEYS 08Z TO 12Z INCLUDING EKN.
OTHERWISE...VFR CONDITIONS WITH HIGH AND SOME MID-LEVEL CLOUDS
OVER THE AREA WITH SOUTHERLY SFC WINDS THROUGHOUT THE PERIOD.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z THURSDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: FOG AT EKN MAY NOT BE AS DENSE AF FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE WED 10/17/12
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EDT 1HRLY 04 05 06 07 08 09 10 11 12 13 14 15
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY L L L L L L H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 06Z THURSDAY...
LOCALIZED IFR CONDITIONS WILL BE POSSIBLE PRIMARILY THURSDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50
NEAR TERM...50
SHORT TERM...ARJ
LONG TERM...SL
AVIATION...50
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1015 AM EDT WED OCT 17 2012
.DISCUSSION...
CURRENT...AXIS OF WELL DEFINED MID LEVEL SHORT WAVE TROUGH LIES FROM
CTRL GA INTO THE NERN GOMEX. FEATURE IS MOVING RAPIDLY EWD...AND HAS
PRODUCED LARGE SHIELD OF MULTILAYERED CLOUDS OUT AHEAD OF IT. VISIBLE
SATELLITE IMAGERY SHOWS SOME SLIGHT THINNING OF THE HIGH CLOUD DECK
FROM ABOUT OSCEOLA/BREVARD COS SOUTH ALTHOUGH UPSTREAM CLOUD TRENDS
INDICATE THAT ANY GLIMPSES OF FILTERED SUNSHINE OVER THE SOUTH WILL
LIKELY BE SHORT-LIVED.
MORNING RAOBS SHOW A PRONOUNCED DRY LATER BETWEEN ABOUT H80-H50...
SO STRATIFORM PRECIP SHIELD HAS SOME WORK TO DO SATURATING THE MID
LEVELS IN ORDER TO GET DOWN TO THE SURFACE. IN ADDITION...EXTENSIVE
NATURE OF MID/HIGH CLOUD CANOPY WILL LIMIT SURFACE HEATING ESPECIALLY
ACROSS THE NORTHERN HALF OF THE CWA...WHICH IN TURN WILL MINIMIZE
POTENTIAL INSTABILITY FOR CONVECTION THERE. RUC ANLYS FIELDS SHOW H25
JET DIVERGENCE OVERHEAD IS MODEST...BUT A LITTLE MORE RESPECTABLE
ACROSS SOUTH FL AND UPSTREAM OVER THE GOMEX. MID LEVEL TEMPS NORTH
AND WEST OF THE CWA ARE FAIRLY COOL...ABOUT -10C (TBW) TO -12C (JAX)
ACCORDING TO THE RAOB DATA...ABOUT -7 (MFL) TO -9C (XMR) FARTHER TO
THE SOUTH AND EAST. OVERALL...IT APPEARS THE POTENTIAL FOR STORMS
WILL BE LIMITED TO THE SOUTHERN CWA...BUT IF ANY DO GET GOING THERE
THEY COULD BECOME STRONG.
MADE SOME MINOR TWEAKS TO POPS...CAPPING THEM AT 50 OVER THE SOUTH
AND LIMITING THUNDER TO ALONG/SOUTH OF A LAKE KISM-KCOF LINE. GIVEN
CURRENT METAR OBS...MAXES IN THE L80S OVER ALL BUT THE SERN CWA
(NEAR 85F) LOOKS FINE.
&&
.AVIATION...CURRENT RAOB MOISTURE PROFILE ARGUES FOR CLOUD LAYERS
AOA 18KFT AND AOB ABOUT 6KFT ATTM. METARS BEAR THIS OUT...ALTHOUGH
WE SHOULD SEE A LITTLE MORE "TOP-DOWN" MOISTENING THROUGHOUT THE DAY.
12Z TAFS REMOVED VCTS AND TEMPO TS GROUPS GIVEN LOWER TS PROBS...
HOWEVER WILL KEEP A CLOSE EYE ON THE MLB-SUA CORRIDOR GIVEN THAT
THE THINNING HIGH CLOUD DECK SEEN ON VIS IMAGERY IS ALLOWING FOR A
LITTLE MORE SURFACE HEATING ATTM.
&&
.MARINE...LOCAL BUOY OBSERVATIONS INDICATE THAT A MODERATE SWELL
CONTINUES TO PRODUCE COMBINED SEAS 4-5FT NEAR SHORE AND ABOUT 7FT
WELL OFFSHORE...WHICH IS RIGHT ON TOP OF THE ONGOING FORECAST. NO
CHANGES NEEDED TO THE CWF...WITH A CAUTIONARY STATEMENT FOR SEAS
REMAINING IN PLACE AREAWIDE. HWO/G-HWO CONTINUES TO HIGHLIGHT HIGH
THREAT FOR DANGEROUS RIP CURRENTS...GIVEN THE LONG PERIOD (12-14SEC)
SWELLS ARE PILING UP WATER BEHIND THE SAND BAR.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...CRISTALDI
LONG TERM/IMPACT WX....VOLKMER
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1053 AM CDT WED OCT 17 2012
.UPDATE...
A FAIRLY SIGNIFICANT REVISION TO THE FCST HAS BEEN DONE.
HOWEVER...THE MODELS ARE HINTING THAT A NONLINEAR EVENT MAY BE IN
THE OFFERING. IF CORRECT...THERE COULD BE ADDITIONAL
CHANGES...POSSIBLY SIGNIFICANT...TO THE FCST.
CURRENT DATA SHOWS THE WAA PRECIP IS SLOWLY EVAPORATING DUE TO THE
INITIALLY DRY ATMOSPHERE ACROSS THE AREA. WHAT IS BEING SUGGESTED
BY THE RAP AND THE 12Z WRF IS THAT THE INITIAL PLUME OF 6-7C 850MB
MOISTURE OVER THE AREA...PER 12Z RAOBS...WILL SHIFT EAST THE
REMAINDER OF THE MORNING. THUS THERE SHOULD BE MORE DRY AIR ALOFT
TO GENERATE MAINLY VIRGA/SPRINKLES WITH SCATTERED SHRA. THIS
SCENARIO IS PARTLY SUPPORTED BY A VORT MAX ROTATING THROUGH THE
AREA PER THE RAP/WRF THIS MORNING WITH LIFT INCREASING AND THEN
DECREASING.
THIS AFTERNOON THE MAIN FORCING WITH THE MAINLY POST FRONTAL
PRECIPITATION WILL MOVE INTO THE WESTERN CWFA SO WILL CONTINUE
WITH LIKELY POPS THERE. THE RAP/WRF CONTINUE TO PUSH MOISTURE
NORTHWARD SO THE REMAINDER OF THE CWFA SHOULD START SEEING MORE
SCATTERED SHRA DEVELOPMENT FOR THE FIRST PART OF THE AFTERNOON.
LATE THIS AFTERNOON THE LIFT AND HEAVY RAIN TOOLS WHEN APPLIED TO
THE RAP/WRF ARE SUGGESTING A FAIRLY SUBSTANTIAL BAND OF CONVECTION
COULD FIRE ROUGHLY ALONG OR JUST EAST OF THE MISSISSIPPI AND MOVE
EAST. SINCE MOISTURE WOULD BE MAXIMIZING JUST PAST PEAK HEATING
WITH THE FRONT IN ROUGHLY THE SAME AREA...THIS SCENARIO HAS SOME
PLAUSIBILITY TO IT. IF CORRECT...THE BETTER PRECIPITATION TOTALS
WOULD BE OVER THE EASTERN THIRD OF THE CWFA. ..08..
&&
.PREV DISCUSSION... /ISSUED 653 AM CDT WED OCT 17 2012/
AVIATION...
STRONG COLD FRONT TO MOVE ACROSS THE TERMINALS TODAY. AHEAD OF THE
FRONT SCATTERED SHOWERS WILL MOVE INTO THE AREA FROM THE WEST.
ISOLATED THUNDER IS POSSIBLE...BUT HAVE LEFT OUT OF TERMINALS DUE
TO TIMING UNCERTAINTY. SOUTH WINDS 10-15KTS WITH GUSTS TO 20KTS TO
DIMINISH AS THE FRONT APPROACHES. THE FRONT IS EXPECTED TO MOVE
ACROSS THE TERMINALS BETWEEN 18Z AND 23Z...INITIALLY SWITCHING
WINDS TO SOUTHWEST AROUND 10-15KTS. A PERIOD OF LIGHT TO MODERATE
SHOWERS IS EXPECTED WITH THE FRONT...WITH A GOOD CHANCE FOR MVFR
VISIBILITIES AT MLI AND BRL FROM 19Z TO 00Z WHICH COULD ALSO
INCLUDE A RUMBLE OF THUNDER. MAINLY VFR CIGS THROUGH THE
PERIOD...THOUGH SOME LOCATIONS MAY RECEIVE A SHORT PERIOD OF MVFR
CIGS WITH STRONGEST BAND OF PRECIPITATION. WILL NEED TO ADD THESE
IN ONCE THERE IS MORE CERTAINTY IN TIMING. AFTER 04Z/18...SKIES
SHOULD BECOME VFR AS THE RAIN MOVES OUT OF THE AREA...AND WINDS
SHOULD MAINTAIN A GUSTY WEST TO NORTHWEST AT 10-15 GUST TO 20 KTS.
LE
PREV DISCUSSION... /ISSUED 340 AM CDT WED OCT 17 2012/
SYNOPSIS...
THE BEGINNINGS OF ANOTHER MUCH NEEDED RAIN EVENT IS DEVELOPING OUT
OVER THE PLAINS THIS MORNING. A STRONG SURFACE LOW OVER EASTERN
SOUTH DAKOTA HAS A STRONG COLD FRONT DRAPED SOUTHWEST FROM IT ACROSS
NEBRASKA AND NORTHWEST KANSAS AND BACK INTO COLORADO. THERE IS ALSO
A WARM FRONT...WHICH PASSED THROUGH THE FORECAST AREA YESTERDAY
DRAPED ACROSS SOUTHERN MINNESOTA AND WISCONSIN. SOUTH WINDS HAVE
STAYED UP VERY NICELY OVERNIGHT AND TEMPERATURES AS OF 3 AM ARE
STILL IN THE MID 50S TO LOW 60S...HIGHLY UNUSUAL FOR THIS TIME OF
YEAR. SHOWERS HAVE ALREADY DEVELOPED OVER WESTERN IOWA...SOUTHWEST
MINNESOTA...EASTERN SOUTH DAKOTA...NEBRASKA AND KANSAS. AT UPPER
LEVELS WE HAVE A NICE PLUME OF HIGHER DEWPOINT AIR AT 850MB
EXTENDING FROM TEXAS UP INTO CENTRAL IOWA AND EVEN SOUTHERN
MINNESOTA...ASSOCIATED WITH A NICE LOW LEVEL FLOW OF 25-30KTS. THAT
THIS INCOMING SYSTEM IS VERY POWERFUL IS INDICATED BY THE DRAMATIC
HEIGHT FALLS AT 500MB OVER THE NORTHERN ROCKIES...AND THE STRONG JET
OF 140KTS+ IMPINGING ON THE WEST OREGON COAST. LE
SHORT TERM...TODAY AND TONIGHT...
THERE IS MUCH TO LOOK AT WITH THIS VERY DYNAMIC SYSTEM THAT WILL
MOVE OVER THE FORECAST AREA IN THE NEXT 24 HOURS. CANNOT WRITE ALL
THAT ONE WOULD LIKE WITH THIS MUCH TO LOOK AT...BUT HERE GOES.
THIS MORNING THIS SYSTEM WILL CONTINUE TO MOVE OUR DIRECTION...AS
THE UPPER LEVEL FEATURES BEGIN TO INTERACT MORE STRONGLY WITH THE
DEEPER MOISTURE NOW AVAILABLE OVER THE FORECAST AREA. THIS MORNING
IN THE WARM SECTOR AIRMASS WE SHOULD GET SOME CONVECTIVE
SHOWERS...SIMILAR TO WHAT WE ARE NOW SEEING OVER CENTRAL IOWA.
THESE SHOWERS SHOULD AFFECT MAINLY THE WESTERN PORTIONS OF THE
FORECAST AREA DUE TO THE DIMINISHING MOISTURE TO THE EAST...AND
THE BETTER ISENTROPIC LIFT TO THE WEST. THE BETTER DYNAMICS ARE
STILL TO COME...AND ARE EXPECTED TO MOVE ACROSS THE FORECAST AREA
THIS AFTERNOON AND EVENING. THE SURFACE LOW NOW OVER EASTERN SOUTH
DAKOTA WILL SWING NORTHEAST ACROSS MINNESOTA TODAY. A SECONDARY
LOW...NOT TERRIBLY STRONG...IS EXPECTED TO DEVELOP OVER THE
FORECAST AREA AS THE SURFACE COLD FRONT MOVES ACROSS THE AREA THIS
AFTERNOON AND EVENING. THIS WILL LIKELY ACT TO INCREASE THE
CONVERGENCE ALONG THE BOUNDARY AND INCREASE OUR PRECIPITATION
POTENTIAL. WE ALSO HAVE A BAND OF STRONG FRONTOGENESIS ALONG AND
BEHIND THE FRONT TO GENERATE PRECIPITATION AS WELL. FOR NOW HAVE A
STEEP GRADIENT OF POPS OVER THE AREA FROM JUST SLIGHT CHANCE POPS
NORTHEAST TO LIKELY OVER THE WESTERN PORTIONS THIS
MORNING...RAMPING UP TO CHANCES WEST AND CATEGORICAL EAST FOR THIS
AFTERNOON. WHILE MUCH OF THE PRECIPITATION WITH THIS SYSTEM WILL
BE STRATIFORM...ESPECIALLY LATER IN THE DAY...THERE WILL AT LEAST
BE SOME EMBEDDED THUNDER THIS AFTERNOON WITH THE STRONGEST LIFT
AND STEEPEST MID LEVEL LAPSE RATES. HIGH TEMPERATURES TODAY TO
ALSO HAVE A STEEP GRADIENT FROM AROUND 60 NORTHWEST TO UPPER 60S
SOUTHEAST.
TONIGHT THE RAIN OVER THE EASTERN PORTIONS OF THE AREA WILL SWEEP
QUICKLY OFF TO THE EAST...LEAVING THE AREA DRY BY THE TIME WE GET TO
MIDNIGHT...OR CLOSE TO IT. THERE MAY BE SOME LINGERING RAIN IN THE
NORTHEAST AFTERWARDS...DEPENDING ON WHICH MODEL YOU USE AND THE
TRACK OF THE SURFACE LOW. TEMPERATURES IN THE LOW 40S WILL SWEEP
INTO THE AREA BEHIND THIS SYSTEM...LIKELY WITH AT LEAST A BRIEF
PERIOD OF AT LEAST THINNER CLOUDS TO AID IN COOLING THE
TEMPERATURES. LE
LONG TERM...THURSDAY THROUGH TUESDAY...
LARGE UPPER LEVEL CLOSED LOW TO PROVIDE CLOUDY...COOL...AND DAMP
WEATHER THU...WHICH IS NOW LOOKING MORE LIKELY TO CONTINUE THROUGH
FRIDAY AS WELL. A PROGRESSIVE UPPER LEVEL PATTERN QUICKLY SWEEPS
THIS SYSTEM EAST OVER THE WEEKEND WITH RETURN FLOW BY SUNDAY LEADING
TO MODERATING TEMPERATURES. THE WARMING TREND CONTINUES INTO
MONDAY...ALONG WITH INCREASING CHANCES FOR RAIN AS MOISTURE
INCREASES IN A SW FLOW AHEAD OF A SLOW MOVING FRONT.
00Z MODELS ARE SOMEWHAT SIMILAR WITH DETAILS OF THE UPPER LOW WITH
THE NOTABLE EXCEPTION BEING THE WRF/NAM...WHICH BECOMES A SLOWER
OUTLIER WITH THE EJECTING SURFACE AND UPPER LOW HANGING FURTHER WEST
ON FRIDAY. WILL KEEP THE FORECAST CLOSE TO THE NON-WRF MODEL
CONSENSUS. STRONG UPPER VORT CENTER AND SURFACE LOW ROTATING AROUND
THE NW AND WESTERN SIDE OF THE UPPER LOW OVER WI WILL DROP SOUTH
INTO THE FORECAST AREA THURSDAY AFTERNOON. WRAP AROUND MOISTURE AND
SUFFICIENT LIFT SHOULD LEAD TO WIDESPREAD LIGHT RAIN OR SHOWERS...
SPREADING FROM NORTHWEST TO SOUTHEAST BY AFTERNOON. WITH INCREASING
CONFIDENCE...POPS HAVE BEEN INCREASED TO LIKELY BY AFTERNOON ACROSS
A LARGER AREA OF THE NORTH. WILL CERTAINLY BE A RAW DAY WITH BRISK
W-NW WINDS AND TEMPERATURES NOT LIKELY CLIMBING OUT OF THE 40S IN
THE NORTH WHERE RAIN ARRIVES EARLIER...WHILE THE FAR SOUTH MAY REACH
THE LOWER 50S. THURSDAY NIGHT POPS HAVE BEEN RAISED TO LIKELY ACROSS
THE BOARD AS THE SURFACE LOW MIGRATES SOUTHEAST ACROSS EASTERN IA
INTO NORTH CENTRAL IL BY MORNING. WHILE MOISTURE WILL BE LIMITED TO
WHAT ROTATES AROUND THE GREAT LAKES UPPER LOW...THE EXTENDED PERIOD
OF LOW LEVEL CONVERGENCE AND MID LEVEL FORCING SHOULD SQUEEZE OUT
RAIN AMOUNTS FROM SEVERAL HUNDREDTHS OF A INCH TO PERHAPS OVER A
QUARTER INCH THU AND THU NIGHT.
FRIDAY...ANOTHER LOBE OF ENERGY ROTATING AROUND THE LOW SHOWN NEAR
CHICAGO WILL KEEP AT LEAST SCATTERED LIGHT RAIN SHOWERS A
POSSIBILITY THROUGH MUCH OF THE DAY. OUTSIDE THE SHOWERS...THE
PROSPECT OF SUNSHINE LOOKS VERY LIMITED IN THE CYCLONIC FLOW AND
LAYER OF MOISTURE SHOWN BELOW 850...WHICH SHOULD LIMIT HIGHS TO THE
LOWER 50S AT BEST.
SATURDAY THROUGH TUESDAY...A PASSING RIDGE AT THE SURFACE AND UPPER
LEVELS SATURDAY INTO SATURDAY NIGHT WILL BE FOLLOWED BY STRONG
RETURN FLOW AND WARM ADVECTION SUNDAY INTO MONDAY. HAVE KEPT HIGHS
TRENDING FROM THE UPPER 50S TO LOWER 60S SATURDAY...RISING TO THE
UPPER 60S TO MID 70S MONDAY WHILE LOWS CLIMB FROM THE 30S FRIDAY
NIGHT TO THE 50S FOLLOWING RISING DEWPOINTS MONDAY MORNING. BASED ON
850 MB TEMPERATURES...HIGHS MONDAY COULD POTENTIALLY BE NEARLY AS
WARM AS YESTERDAY. OVERALL...THE 00Z MODELS HAVE COME INTO BETTER
AGREEMENT WITH THE UPPER LEVEL PATTERN AND SURFACE FRONTAL FEATURES
MONDAY INTO TUESDAY...DEVELOPING WARM ADVECTION AND MOISTURE RETURN
THAT COULD LEAD TO RAIN CHANCES FROM LATE SUNDAY NIGHT THROUGH
TUESDAY. BASED ON THE WARM ADVECTION...RETURN OF GULF MOISTURE...AND
STEEP MID LEVEL LAPSE RATES...THUNDERSTORMS WILL BE POSSIBLE
ESPECIALLY MONDAY INTO MONDAY NIGHT AND HAVE ADDED MENTION.
SHEETS
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
633 AM CDT WED OCT 17 2012
...UPDATED AVIATION DISCUSSION...
.SHORT TERM /TODAY/...
SEVERAL FORECAST CONCERNS TODAY WITH STRONG COLD FRONT EXPECTED TO
SWEEP ACROSS IOWA THIS MORNING. FROPA WILL BE BETWEEN 11-15Z THIS
MORNING FROM WEST TO EAST ACROSS THE FORECAST AREA. LEANED TOWARD A
BLEND OF THE SHORT TERM HIGH-RESOLUTION MODELS HRRR/4.0KM WRF AND
SREF/NAM12 AS THEY SEEMED TO HAVE BEST HANDLE ON TIMING OF FRONT AND
POPS.
SHARP PRESSURE GRADIENT COMBINED WITH A DECENT TROPOPAUSE UNDULATION
LATE THIS MORNING INTO THE AFTERNOON WILL PROVIDE A WINDY DAY. WINDS
ATOP THE MIX LAYER RANGE FROM 30-35KTS WEST OF THE INTERSTATE 35 AND
WITH THE CLOUDS CLEARING OUT THIS AFTERNOON IN WESTERN IOWA...SHOULD
ENHANCE THE WIND GUSTS. TWEAKED WINDS UP SLIGHTLY IN THIS AREA
THROUGH 18Z. STILL BORDER LINE WIND ADVISORY ATTM. KEPT MENTION OF
THE NON-DIURNAL TEMPS WITH THE STRONG CAA DEVELOPING LATE THIS
MORNING. 850MB TEMPS DROP TO +2C TO +4C BY THIS AFTERNOON. A NICE
STRATUS DECK LOOKS TO MOVE IN BY AROUND 00Z THURSDAY AS RH AT 850MB
INCREASES GREATER THAN 80 PERCENT. INCREASED SKY COVER ACROSS THE FAR
NORTHWEST.
BEST POPS WILL BE ACROSS THE SOUTHEAST LATE THIS MORNING WHERE
STRONGEST FORCING AND BEST THETA-E ADVECTION IS LOCATED. IN
ADDITION...SOME ELEVATED INSTABILITY IS PRESENT AND LIKELY WILL THE
HIGHER QPF AMOUNTS. THE LATEST HRRR COINCIDES WITH THIS THINKING AND
TWEAKED UP QPF THROUGH 18Z.
.LONG TERM /TONIGHT THROUGH TUESDAY/...
DEEPENING UPPER LOW WILL BE DIVING INTO MINNESOTA AND IOWA OVERNIGHT
WITH AN IMPRESSIVE 90-100KT JET ROUNDING THE BASE OF THE TROUGH AND
BEING INGESTED INTO THE SYSTEM THROUGH THURSDAY. THERE IS A
SIGNIFICANT AMOUNT OF ENERGY EMBEDDED IN THE FLOW WHICH WILL WRAP
AROUND THE SYSTEM THE NEXT FEW DAYS. ONE OF THE MORE VIGOROUS
IMPULSES IS MOVING THROUGH SRN IA AND MISSOURI TODAY AND WILL WRAP
AROUND THE SYSTEM AND MOVE ACROSS MINNESOTA AND IOWA ON THURSDAY AND
WILL SHIFT THE AXIS OF THE UPPER LOW BACK WEST A BIT. THIS SYSTEM
WILL ALSO HAVE GOOD THETA-E ADVECTION EMBEDDED WHICH WILL HELP PUSH
PWATS BACK TO NEAR 0.75 INCHES AND COMBINED WITH THE KINEMATIC
ENERGY...SHOULD RESULT IN WIDESPREAD SHOWERS BY THURSDAY AFTERNOON
AND EVENING. IN ADDITION...AN INCREASING PRESSURE GRADIENT OVER
WESTERN IOWA AND WINDS APPROACHING 50 KTS IN THE LOWEST 4 KFT OF THE
ATMOSPHERE DOES RAISE CONCERNS ABOUT POTENTIAL WIND ADVISORY
CRITERIA. IT WILL BE CLOSE...WEST OF INTERSTATE 35 THOUGH THERE ARE
A FEW NEGATIVES THAT WILL KEEP THE WINDS FROM REACHING MAX
POTENTIAL. A STRATUS DECK SHOULD ENGULF MUCH OF IOWA ON THURSDAY AND
THIS WILL LIMIT HIGH TEMPERATURES AND POTENTIAL FOR MIXING.
TEMPERATURES WILL LIKELY LINGER IN THE 40S FOR MUCH OF THE DAY. THE
GOOD REGION OF SUBSIDENCE WILL BE WEST OF THE MISSOURI RIVER AND
THAT WILL BE THE REGION FOR GOOD MOMENTUM TRANSFER AND BETTER MIXING
OF WINDS ALOFT.
PRECIPITATION CHANCES WILL CONTINUE THURSDAY NIGHT BEFORE THE BULK
OF THE ENERGY ROUNDS THE BASE OF THE UPPER LOW AND IT BEGINS TO
SHIFT OFF TO THE EAST ON FRIDAY. A FEW SHOWERS MAY LINGER FRIDAY
BEFORE MID LEVEL RIDGING MOVES IN FOR THE WEEKEND WITH WARMER
TEMPERATURES. STRENGTHENING HIGH PRESSURE OVER THE SOUTHEAST CONUS
AND REGION OF LOW PRESSURE TO THE WEST WILL ENHANCE THE WARM
ADVECTION INTO SUNDAY. AS MENTIONED LAST NIGHT...THIS SET UP IS
CONDUCIVE TO A STRONG SURGE OF LOW LEVEL GULF MOISTURE. SOME MINOR
TIMING DETAILS ON WHEN THIS MOISTURE ARRIVES IN IOWA...EITHER LATE
SUNDAY OR SUNDAY NIGHT. THIS MOISTURE WILL LIFT NORTH AND POOL AHEAD
OF A SFC BOUNDARY THAT WILL BE INCHING SOUTHEAST THROUGH IOWA SUNDAY
THROUGH MONDAY. THIS TYPE OF MOISTURE OFTEN RESULTS IN A STRATUS
FIELD AND MAY BE ACCOMPANIED WITH FOG OR DRIZZLE. ENHANCED VERTICAL
TURBULENCE WITH THE SFC BOUNDARY NEAR BY ENHANCES THAT POSSIBILITY.
ANY STRATUS CERTAINLY WOULD IMPACT TEMPERATURES. A SHORT WAVE
LIFTING THROUGH THE SOUTHWEST FLOW WILL INTRODUCE SOME CONVECTIVE
POTENTIAL MONDAY AND MONDAY NIGHT. THE MILD SOUTHWEST FLOW WILL
MAINTAIN THROUGH THE END OF THE EXTENDED WITH HIGHS IN THE 60S AND
70S.
&&
.AVIATION...17/12Z
COLD FRONT WILL PUSH THROUGH THIS MORNING AND WINDS LOOK TO SHIFT
AND INCREASE OUT OF THE WEST B/T 13-15Z. THERE IS SOME LIGHT SHOWER
ACTIVITY BUT EXPECTING CONDITIONS TO REMAIN VFR FOR VIS AND CIGS.
WINDS WILL CONTINUE TO INCREASE THROUGH THE AFTERNOON WITH GUSTS
NEAR 30KTS. PRESSURE GRADIENT REMAINS TIGHT OVERNIGHT TONIGHT WITH
ANOTHER STRATUS DECK MOVING INTO NORTHERN IOWA THIS EVENING. KEPT
VFR CONDITIONS FOR NOW AS MVFR/IFR CIGS LOOK TO AFFECT NORTHERN IOWA
PAST 06Z THURSDAY AND TIMING AND LOCATION STILL UNCERTAIN.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...DONAVON
AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
625 AM CDT WED OCT 17 2012
.UPDATED FOR 12Z AVIATION DISCUSSION BELOW...
.DISCUSSION...
PRETTY VIGOROUS SYSTEM TO AFFECT WX ACROSS AREA FOR NEXT COUPLE OF
DAYS WITH SOME NEEDED PCPN AND A LOT OF WIND. STRENGTH OF
DEEPENING UPPER TROF DROPPING OUT OF SASK EVIDENCE BY 500 MB
HEIGHT FALLS OF AS MUCH AS 150 M IN GGW THIS EVENING. THE UPPER
TROF PROGGED BY MODELS TO CONTINUE TO WIND UP AS IT DROPS SE
ACROSS AREA WITH 140 KT UPPER JET PLOWING ACROSS THE PACIFIC NW
INTO THE CENTRL PLAINS.
AHEAD OF THIS FEATURE WV IMAGERY SHOWING A NICE VORT LIFTING ENE
ACROSS SODAK...CURRENTLY AROUND KHON. RADAR MOSAIC SHOWING A NICE
AREA OF SHWRS ACROSS MUCH OF NE/EC SODAK AHEAD OF THIS FEATURE.
NARROW FATHER FAST MOVING BAND OF SHOWERS SOUTH OF THIS AREA IS
MOVING RAPIDLY ACROSS SC MN. HRRR AND LOCAL WRF KEEP MAIN AREA OF
SHOWERS THIS MORNING ACROSS WC INTO CENTRAL MN ASSOCIATED WITH
SODAK VORT...AND THIS SEEMS REASONABLE GIVEN RADAR TRENDS. ANOTHER
AREA OF SHOWERS DEVELOPS ACROSS IA/SE MN INTO WI AHEAD OF CDFNT
LATER THIS MRNG INTO THE AFTN. LOWERED POPS A BIT ACROSS S AREAS
AS WELL AS QPF...KEEPING LIKELY POPS MORE INTO CNTL MN.
RETAINED WIND ADVY SW OF THE MN FOR LT MRNG INTO EARLY EVENING.
STRONGEST CAA AND SURFACE PRESSURE RISES REMAIN S OF THAT
AREA...MORE ACROSS SODAK/NEB INTO IA BUT SOME OF THE HIER TERRAIN
SHUD SEE SOME SUSTAINED WINDS ARND 30 MPH. SHARPEST FALL IN
DEWPOINTS AND RH ALSO SOUTH OF OUR AREA SO WILL NOT BE ISSUING ANY
FIRE WX HEADLINES...BUT WILL ADDRESS THE STRONG WINDS IN A HEADLINE.
AS UPPER LOW BEGINS TO WIND UP ON THURSDAY INTO THURS NITE ACROSS S
MN/N IA STRONG ISENTROPIC LIFT SETS IN A STRONG WAA PATTERN NORTH
OF THE LOW WHICH SHUD BRING IN LIKELY POPS ESP ACROSS WESTERN
HALF OF CWA. DIFFERENCES IN MODEL PLACEMENT OF SFC LOW...BUT THEY
ALL TIGHTEN PRESSURE GRADIENT MAINLY ACROSS W MN DURING THE DAY
THURSDAY WHICH MAY REQUIRE ANOTHER WIND ADVY.
SOME LINGERING PCPN INTO FRIDAY...THEN WARMING AND DRYING TREND
FOR THE WEEKEND AS DEEP LOW PRESSURE GETS KICKED OUT AND SW FLOW
RETURNS. SHUD SEE HIGHS NEAR 60 SW AREAS ON SATURDAY AND INTO THE
60S ACROSS THE AREA FOR SUNDAY.
&&
.AVIATION.../12Z TAF ISSUANCE/
MODELS SUGGEST BEST FORCING ASSOCIATED WITH UPPER LOW WILL MOVE
ACROSS THE NORTHWEST PORTION OF THE FORECAST AREA TODAY. THIS WILL
AFFECT KAXN/KSTC MUCH OF THE DAY WITH -RA THIS MORNING AND SHOULD
EXIT TO THE NORTH THIS AFTERNOON AS SURFACE LOW LIFTS INTO NORTHEAST
MN. MVFR CONDITIONS EXPECTED WITH THIS AREA OF PRECIPITATION. WILL
KEEP THE REMAINDER OF THE REGION VFR FOR NOW AS COLD FRONT MOVES
THROUGH. SURFACE WINDS WILL BECOME MORE SOUTHWEST TO WEST WITH
FROPA AND WILL BE GUSTY OVER WESTERN AREAS....SPREADING EAST WITH
FROPA. STRONGEST GRADIENT REMAINS OVER WESTERN AREAS THROUGH
TONIGHT/THURSDAY. AS SYSTEM OCCLUDES LATER TODAY...FORCING IS
DIRECTED BACK ACROSS WESTERN AREAS OVERNIGHT AND INTO THE EAST ON
THURSDAY. THIS WILL DROP CEILINGS TO IFR AT KAXN AFTER 07Z THU AND
COULD MOVE INTO KSTC BEFORE 12Z THU. WILL HAVE TO MONITOR
DEVELOPMENT OF UPPER LOW. OTHER AREAS WILL SEE CEILING LOWER TO MVFR
AT LEAST-IN THE EAST AFTER 06Z THU.
KMSP...WILL MAINTAIN VFR CONDITIONS THROUGH THIS EVENING. SOME HAZY
CONDITIONS DROPPING VSBY TO 6SM THIS AM...THEN SOME LIGHT -SHRA
POSSIBLE AS COLD FRONT MOVES IN THROUGH 18Z. THIS WILL SHIFT WINDS
TO MORE WEST/SOUTHWEST BY MIDDAY AND MORE WESTERLY THIS AFTERNOON.
SHOULD SEE SOME GUSTS NEAR 25 KNOTS AS FRONT MOVES THROUGH. MODELS
SUGGEST UPPER LOW ROTATING MORE PRECIPITATION TO THE SOUTHWEST LATER
TONIGHT AND OVER THE EAST THURSDAY. WILL LOWER CEILING TO MVFR
AGAIN AFTER 06Z THU AND MENTION VCSH FOR NOW.
/OUTLOOK FOR KMSP/
THU...MVFR CIGS WITH MVFR VSBY DURING SHRA. IFR CIGS POSSIBLE.
W/NW WINDS 15 TO 25 KT WITH GUSTS ABOVE 30 KTS.
FRI...MVFR CIGS...SCT -SHRA. NW WINDS 10 KTS.
SAT...VFR. S WINDS 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND ADVISORY FROM 10 AM THIS MORNING TO 7 PM CDT THIS EVENING
FOR BROWN-LAC QUI PARLE-MARTIN-REDWOOD-WATONWAN-YELLOW
MEDICINE.
WI...NONE.
&&
$$
BAP/DE
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1040 AM EDT WED OCT 17 2012
.SYNOPSIS...
HIGH PRESSURE SLIPS EAST WEDNESDAY. COLD FRONT BRINGS GOOD CHANCE
FOR SHOWERS THURSDAY INTO FRIDAY. THE PARENT DEEP LOW PRESSURE
SYSTEM APPROACHES FROM THE NORTHWEST FRIDAY NIGHT INTO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
WEAK TROUGH AXIS CENTERED OVER OHIO/INDIANA BORDER INTO EASTERN
KENTUCKY/TENNESSEE BRINGING SCATTERED CLOUDS TO THE WESTERN ZONES.
FEATURE WILL LIFT OUT LATER THIS AFTERNOON. PRESSURE GRADIENT TO
TIGHTEN UP WITH COLD FRONT APPROACH AND SUBSEQUENT STEADY PRESSURE
FALLS FOR THE NEXT 24 HOURS.
PREVIOUS DISCUSSION...
ZONAL FLOW WILL BECOME INCREASINGLY SOUTHWESTERLY TODAY IN ADVANCE
OF A CLOSED UPPER LOW DIGGING SOUTHEASTWARD ACROSS THE UPPER
MIDWEST. AN EMBEDDED S/W TROUGH IN THE MEAN FLOW WILL BRUSH BY THE
AREA TO THE NORTH/NORTHWEST THIS MORNING. NO PRECIP IS EXPECTED WITH
THIS FEATURE BUT WILL RESULT IN INCREASED CLOUD COVER...PARTICULARLY
DURING THE MORNING HOURS AND ACROSS THE SE OHIO ZONES. INHERITED MAX
TEMPS GENERALLY IN THE MID/UPPER 70S LOWLANDS LOOK GOOD WITH ONLY A
COUPLE MINOR TWEAKS.
WED EVENING AND OVERNIGHT THE UPPER LOW WILL BE CONTINUING TO
PROGRESS SE-WARD...ESSENTIALLY LOCATED ROUGHLY OVER SOUTHERN MN BY
12Z THU. RUN TO RUN NAM/GFS COMPS SHOW GENERAL CONSISTENCY WITH ITS
TRACK...BUT BOTH SHOW SLIGHT DECREASE IN STRENGTH. ATTENDANT SFC LOW
WILL BE ROUGHLY OVER WISCONSIN WITH THE COLD FRONT EXTENDING
SOUTHEASTWARD. STRONG FORCING FOR ASCENT MOVES OVER THE FORECAST
AREA AFTER 06Z ALONG WITH GOOD DYNAMICS...INCLUDING MIDLEVEL
DIFFLUENT FLOW...GOOD POTENTIAL VORT ADVECTION...AS WELL AS DECENT
LLVL WARM ADVECTION AND A STRONG 850MB JET LIFTING NE-WARD ACROSS
EASTERN KY PRIOR TO FRONT/S ARRIVAL. DESPITE ALL THIS...DRY LOW
LEVELS WILL BE IN PLACE...WITH GOOD LLVL MOISTURE ARRIVING POST-FRONT.
850MB AND 700MB FLOW WILL BE PARALLEL TO GENERALLY VEERED FROM THE
ORIENTATION OF THE SFC FRONT WHICH WOULD USUALLY BE A PRECURSOR FOR
A PRE-FRONTAL PRECIP REGIME. ALL THIS TO SAY THAT THE MAIN PRECIP
SHOULD BE ALONG AND POST-FRONTAL IN A RELATIVELY THIN BAND GENERATED
MAINLY BY FRONTO-G FORCING. BOTH THE LATEST NAM AND SREF DEPICT THE
SFC FRONT JUST ENTERING THE WESTERN KY ZONES AT 12Z...WITH THE GFS
JUST SLIGHTLY SLOWER. WITH THIS IN MIND...INHERITED POP GRIDS WHICH
BRING PRECIP INTO THE WESTERN KY ZONES AROUND 09Z WITH THE BULK OF
THE PRECIP ARRIVING NEAR AND AFTER 12Z THU STILL LOOK REASONABLE
WITH ONLY MINOR ADJUSTMENTS. FINALLY...WITH STRONG LLVL SOUTHWEST
FLOW AND WARM ADVECTION...CONTINUED PREV FCST OF GOING WELL ABOVE
GUIDANCE ON OVERNIGHT LOWS IN THE MID/UPPER 50S LOWLANDS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
THE NAM/CMC/GFS/ECMWF ARE IN AGREEMENT WITH THE TIMING OF
CONVECTION ASSOCIATED WITH APPROACHING COLD FRONT OVER SOUTHEAST
OH BY 12Z THURSDAY. HOWEVER...THERE ARE INTENSITY DIFFERENCES IN
QPF FIELDS...AS WELL AS IN THE UPPER LEVEL SUPPORT. THE GFS HAS
STRONGER MID LEVEL FORCING ACROSS THE OH RIVER...WHILE THE NAM
WEAKENS ITS FORCING. NEVERTHELESS...BELIEVE IN PREVIOUS FORECAST
BRINGING HIGH CATEGORICAL POPS INTO SOUTHEAST OH BY 12Z...DECREASING
TO LIKELY AS THE FRONT SWEEPS EAST INTO THE AFTERNOON HOURS. H850
WINDS AHEAD OF THE FRONT ARE BETWEEN 55-60 KNOTS IN THE WARM
SECTOR. DEWPOINTS WILL INCREASE INTO THE LOWER 50S UNDER DEEP
SOUTH SOUTHWEST FLOW...DESPITE OF AFTERNOON MIXING.
HOWEVER...PWATS LOOKS RATHER LOW BARELY OVER ONE INCH.
VERY WEAK LAYERED CAPE...BUT DEEP LAYERED SHEAR EXCEEDING 55
KNOTS...STORM RELATIVE HELICITY EXCEEDING 300 M2/S2...AND BOUNDARY
LAYER CONVERGENCE ALONG THE FRONT CALLS FOR A DYNAMIC ENVIRONMENT
CAPABLE TO PRODUCE STORMS. KEPT STORM MENTION WITH LIKELY POPS
DECREASING IN COVERAGE AS THE FRONT MOVE EAST THURSDAY AFTERNOON.
SEVERE STORMS ARE NOT ANTICIPATED AT THIS TIME...STRONG GUSTY FLOW
ARE WORTH TO BE MENTIONED IN THE HWO.
STRONG GUSTY WINDS CAN MIX DOWN TO SFC ALONG FRONTAL
CONVECTION...AND CAN BE POSSIBLE ALSO OVER THE HIGHER ELEVATIONS.
KEPT SFC FRONT EXITING EASTERN MOUNTAINS BY 21Z..IF NOT A LITTLE
SOONER. EXPECT DRY SLOT TO PRODUCE SOME BREAKS IN THE CLOUDS
MAINLY SOUTH AND CENTRAL SECTIONS OF OUR CWA.
THIS COLD FRONT...EXTENDS NORTHWEST AS A OCCLUDED FRONT INTO THE
PARENT DEEP LOW PRESSURE SYSTEM OVER THE GREAT LAKES. SOME
DIFFERENCES NOTED IN THE H5 LOW CENTER...WITH THE NAM SHOWING IT
OVER THE OH VALLEY...THE GFS OVER THE GREAT LAKES...AS WELL AS THE
ECMWF AND CMC. THEREFORE...PER CONSENSUS...EXPECT LOW PRESSURE
TO APPROACH OUR AREA FROM THE NORTHWEST...BUT LIFT NORTHEAST
FRIDAY NIGHT. RAP AROUND MOISTURE BEHIND THE DEPARTURE LOW WILL
BRING CHANCES OF STRATIFORM RAIN ACROSS THE NORTHERN PORTIONS OF
THE AREA FRIDAY...INTO EARLY SATURDAY MORNING...PER GFS/ECMWF/CMC
CONSENSUS.
KEPT WIND GUSTS 20-30 KNOTS DO TO CAA AND EFFICIENT MOMENTUM
TRANSFER AS SEEN IN INVERTED V FEATURE IN BUFKIT SOUNDING FRIDAY.
WENT A DEGREE OR TWO LOWER THAN MAV/MET GUIDANCE PER UNCERTAINTY
OF CLOUD COVER...GENERALLY UPPER 60S LOWLANDS...RANGING INTO THE
MID 50S HIGHEST ELEVATIONS...FOR THURSDAY. EXPECT A COOLER TREND
THURSDAY NIGHT AND FRIDAY UNDER CAA...AND CLOUD COVER.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
STILL SOME ISSUES WITH MODEL AGREEMENT IN THE LONG TERM PERIOD IN
TERMS OF TIMING AND PATH OF EXITING LOW PRESSURE. GFS IS STILL
FASTER AND FARTHER TO THE NORTH WITH THE UPPER LOW THAN THE ECMWF.
BUT REGARDLESS...A GRADUAL DRYING TREND IS EXPECTED TO BEGIN ON
SATURDAY AS THE UPPER LOW GRADUALLY PUSHES EAST...AND A RIDGE OF
HIGH PRESSURE GRADUALLY STARTS TO BUILD IN FOR THE BEGINNING OF NEXT
WEEK. DID START TO BUMP TEMPERATURES UP A BIT FROM PREVIOUS
FORECAST...AND DRY OUT FORECAST FOR LATE THIS WEEK/EARLY NEXT WEEK.
SOME ISSUES CONCERNING THE TIMING OF NEXT SYSTEM...PROGGED TO ENTER
CWA BY MID WEEK...BUT FOR NOW...MAINTAINED A DRY FORECAST INTO
PERIOD DUE TO UNCERTAINTY.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
12Z WEDNESDAY THRU 12Z THURSDAY...
PASSING HIGH CIRRUS PASSING OVERHEAD...PARTICULARLY OVER SE OHIO
WHERE SOME MIDLEVEL CLOUDS ALSO BEING OBSERVED. ALL SITES CURRENTLY
VFR EXCEPT EKN WHERE EXPECTED VLIFR VIS/LOW STRATUS WITH FREEZING
FOG HAS MATERIALIZED. THIS SHOULD BURN OFF BY 14Z-15Z...WITH VFR
CONDITIONS EXPECTED FOR THE REMAINDER OF THE VALID PERIOD AT ALL
SITES. INCREASING AND LOWERING CLOUDS HOWEVER CAN BE EXPECTED
ACROSS THE WEST NEAR THE END OF THE PERIOD AS A COLD FRONT WITH
SHOWERS APPROACHES. MUCH IF NOT ALL OF THE ASSOCIATED PRECIP
SHOULD MOVE IN AFTER 12Z THU. ALSO OF NOTE...LOW LEVEL WIND SHEAR
MAY BE REALIZED BTWN 06Z-12Z THU MORNING...ESPECIALLY FOR SOUTHERN
AND WESTERN SITES...AS A STRONG 50-60KT LOW LEVEL JET PUSHES INTO
THE AREA FROM THE WEST.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z THURSDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: DISSIPATION OF FOG/LOW STRATUS MAY VARY SLIGHTLY.
TIMING OF LOWERING CIGS AND SHOWERS LATE IN THE PERIOD MAY VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY L H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z THURSDAY...
LOCALIZED IFR CONDITIONS WILL BE POSSIBLE PRIMARILY THURSDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50
NEAR TERM...50/26
SHORT TERM...ARJ
LONG TERM...SL
AVIATION...50
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
642 AM EDT WED OCT 17 2012
.SYNOPSIS...
HIGH PRESSURE SLIPS EAST WEDNESDAY. COLD FRONT BRINGS GOOD CHANCE
FOR SHOWERS THURSDAY INTO FRIDAY. THE PARENT DEEP LOW PRESSURE
SYSTEM APPROACHES FROM THE NORTHWEST FRIDAY NIGHT INTO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
ZONAL FLOW WILL BECOME INCREASINGLY SOUTHWESTERLY TODAY IN ADVANCE
OF A CLOSED UPPER LOW DIGGING SOUTHEASTWARD ACROSS THE UPPER
MIDWEST. AN EMBEDDED S/W TROUGH IN THE MEAN FLOW WILL BRUSH BY THE
AREA TO THE NORTH/NORTHWEST THIS MORNING. NO PRECIP IS EXPECTED WITH
THIS FEATURE BUT WILL RESULT IN INCREASED CLOUD COVER...PARTICULARLY
DURING THE MORNING HOURS AND ACROSS THE SE OHIO ZONES. INHERITED MAX
TEMPS GENERALLY IN THE MID/UPPER 70S LOWLANDS LOOK GOOD WITH ONLY A
COUPLE MINOR TWEAKS.
WED EVENING AND OVERNIGHT THE UPPER LOW WILL BE CONTINUING TO
PROGRESS SE-WARD...ESSENTIALLY LOCATED ROUGHLY OVER SOUTHERN MN BY
12Z THU. RUN TO RUN NAM/GFS COMPS SHOW GENERAL CONSISTENCY WITH ITS
TRACK...BUT BOTH SHOW SLIGHT DECREASE IN STRENGTH. ATTENDANT SFC LOW
WILL BE ROUGHLY OVER WISCONSIN WITH THE COLD FRONT EXTENDING
SOUTHEASTWARD. STRONG FORCING FOR ASCENT MOVES OVER THE FORECAST
AREA AFTER 06Z ALONG WITH GOOD DYNAMICS...INCLUDING MIDLEVEL
DIFFLUENT FLOW...GOOD POTENTIAL VORT ADVECTION...AS WELL AS DECENT
LLVL WARM ADVECTION AND A STRONG 850MB JET LIFTING NE-WARD ACROSS
EASTERN KY PRIOR TO FRONT/S ARRIVAL. DESPITE ALL THIS...DRY LOW
LEVELS WILL BE IN PLACE...WITH GOOD LLVL MOISTURE ARRIVING POST-FRONT.
850MB AND 700MB FLOW WILL BE PARALLEL TO GENERALLY VEERED FROM THE
ORIENTATION OF THE SFC FRONT WHICH WOULD USUALLY BE A PRECURSOR FOR
A PRE-FRONTAL PRECIP REGIME. ALL THIS TO SAY THAT THE MAIN PRECIP
SHOULD BE ALONG AND POST-FRONTAL IN A RELATIVELY THIN BAND GENERATED
MAINLY BY FRONTO-G FORCING. BOTH THE LATEST NAM AND SREF DEPICT THE
SFC FRONT JUST ENTERING THE WESTERN KY ZONES AT 12Z...WITH THE GFS
JUST SLIGHTLY SLOWER. WITH THIS IN MIND...INHERITED POP GRIDS WHICH
BRING PRECIP INTO THE WESTERN KY ZONES AROUND 09Z WITH THE BULK OF
THE PRECIP ARRIVING NEAR AND AFTER 12Z THU STILL LOOK REASONABLE
WITH ONLY MINOR ADJUSTMENTS. FINALLY...WITH STRONG LLVL SOUTHWEST
FLOW AND WARM ADVECTION...CONTINUED PREV FCST OF GOING WELL ABOVE
GUIDANCE ON OVERNIGHT LOWS IN THE MID/UPPER 50S LOWLANDS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
THE NAM/CMC/GFS/ECMWF ARE IN AGREEMENT WITH THE TIMING OF
CONVECTION ASSOCIATED WITH APPROACHING COLD FRONT OVER SOUTHEAST
OH BY 12Z THURSDAY. HOWEVER...THERE ARE INTENSITY DIFFERENCES IN
QPF FIELDS...AS WELL AS IN THE UPPER LEVEL SUPPORT. THE GFS HAS
STRONGER MID LEVEL FORCING ACROSS THE OH RIVER...WHILE THE NAM
WEAKENS ITS FORCING. NEVERTHELESS...BELIEVE IN PREVIOUS FORECAST
BRINGING HIGH CATEGORICAL POPS INTO SOUTHEAST OH BY 12Z...DECREASING
TO LIKELY AS THE FRONT SWEEPS EAST INTO THE AFTERNOON HOURS. H850
WINDS AHEAD OF THE FRONT ARE BETWEEN 55-60 KNOTS IN THE WARM
SECTOR. DEWPOINTS WILL INCREASE INTO THE LOWER 50S UNDER DEEP
SOUTH SOUTHWEST FLOW...DESPITE OF AFTERNOON MIXING.
HOWEVER...PWATS LOOKS RATHER LOW BARELY OVER ONE INCH.
VERY WEAK LAYERED CAPE...BUT DEEP LAYERED SHEAR EXCEEDING 55
KNOTS...STORM RELATIVE HELICITY EXCEEDING 300 M2/S2...AND BOUNDARY
LAYER CONVERGENCE ALONG THE FRONT CALLS FOR A DYNAMIC ENVIRONMENT
CAPABLE TO PRODUCE STORMS. KEPT STORM MENTION WITH LIKELY POPS
DECREASING IN COVERAGE AS THE FRONT MOVE EAST THURSDAY AFTERNOON.
SEVERE STORMS ARE NOT ANTICIPATED AT THIS TIME...STRONG GUSTY FLOW
ARE WORTH TO BE MENTIONED IN THE HWO.
STRONG GUSTY WINDS CAN MIX DOWN TO SFC ALONG FRONTAL
CONVECTION...AND CAN BE POSSIBLE ALSO OVER THE HIGHER ELEVATIONS.
KEPT SFC FRONT EXITING EASTERN MOUNTAINS BY 21Z..IF NOT A LITTLE
SOONER. EXPECT DRY SLOT TO PRODUCE SOME BREAKS IN THE CLOUDS
MAINLY SOUTH AND CENTRAL SECTIONS OF OUR CWA.
THIS COLD FRONT...EXTENDS NORTHWEST AS A OCCLUDED FRONT INTO THE
PARENT DEEP LOW PRESSURE SYSTEM OVER THE GREAT LAKES. SOME
DIFFERENCES NOTED IN THE H5 LOW CENTER...WITH THE NAM SHOWING IT
OVER THE OH VALLEY...THE GFS OVER THE GREAT LAKES...AS WELL AS THE
ECMWF AND CMC. THEREFORE...PER CONSENSUS...EXPECT LOW PRESSURE
TO APPROACH OUR AREA FROM THE NORTHWEST...BUT LIFT NORTHEAST
FRIDAY NIGHT. RAP AROUND MOISTURE BEHIND THE DEPARTURE LOW WILL
BRING CHANCES OF STRATIFORM RAIN ACROSS THE NORTHERN PORTIONS OF
THE AREA FRIDAY...INTO EARLY SATURDAY MORNING...PER GFS/ECMWF/CMC
CONSENSUS.
KEPT WIND GUSTS 20-30 KNOTS DO TO CAA AND EFFICIENT MOMENTUM
TRANSFER AS SEEN IN INVERTED V FEATURE IN BUFKIT SOUNDING FRIDAY.
WENT A DEGREE OR TWO LOWER THAN MAV/MET GUIDANCE PER UNCERTAINTY
OF CLOUD COVER...GENERALLY UPPER 60S LOWLANDS...RANGING INTO THE
MID 50S HIGHEST ELEVATIONS...FOR THURSDAY. EXPECT A COOLER TREND
THURSDAY NIGHT AND FRIDAY UNDER CAA...AND CLOUD COVER.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
STILL SOME ISSUES WITH MODEL AGREEMENT IN THE LONG TERM PERIOD IN
TERMS OF TIMING AND PATH OF EXITING LOW PRESSURE. GFS IS STILL
FASTER AND FARTHER TO THE NORTH WITH THE UPPER LOW THAN THE ECMWF.
BUT REGARDLESS...A GRADUAL DRYING TREND IS EXPECTED TO BEGIN ON
SATURDAY AS THE UPPER LOW GRADUALLY PUSHES EAST...AND A RIDGE OF
HIGH PRESSURE GRADUALLY STARTS TO BUILD IN FOR THE BEGINNING OF NEXT
WEEK. DID START TO BUMP TEMPERATURES UP A BIT FROM PREVIOUS
FORECAST...AND DRY OUT FORECAST FOR LATE THIS WEEK/EARLY NEXT WEEK.
SOME ISSUES CONCERNING THE TIMING OF NEXT SYSTEM...PROGGED TO ENTER
CWA BY MID WEEK...BUT FOR NOW...MAINTAINED A DRY FORECAST INTO
PERIOD DUE TO UNCERTAINTY.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
12Z WEDNESDAY THRU 12Z THURSDAY...
PASSING HIGH CIRRUS PASSING OVERHEAD...PARTICULARLY OVER SE OHIO
WHERE SOME MIDLEVEL CLOUDS ALSO BEING OBSERVED. ALL SITES CURRENTLY
VFR EXCEPT EKN WHERE EXPECTED VLIFR VIS/LOW STRATUS WITH FREEZING
FOG HAS MATERIALIZED. THIS SHOULD BURN OFF BY 14Z-15Z...WITH VFR
CONDITIONS EXPECTED FOR THE REMAINDER OF THE VALID PERIOD AT ALL
SITES. INCREASING AND LOWERING CLOUDS HOWEVER CAN BE EXPECTED
ACROSS THE WEST NEAR THE END OF THE PERIOD AS A COLD FRONT WITH
SHOWERS APPROACHES. MUCH IF NOT ALL OF THE ASSOCIATED PRECIP
SHOULD MOVE IN AFTER 12Z THU. ALSO OF NOTE...LOW LEVEL WIND SHEAR
MAY BE REALIZED BTWN 06Z-12Z THU MORNING...ESPECIALLY FOR SOUTHERN
AND WESTERN SITES...AS A STRONG 50-60KT LOW LEVEL JET PUSHES INTO
THE AREA FROM THE WEST.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z THURSDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: DISSIPATION OF FOG/LOW STRATUS MAY VARY SLIGHTLY.
TIMING OF LOWERING CIGS AND SHOWERS LATE IN THE PERIOD MAY VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EDT 1HRLY 07 08 09 10 11 12 13 14 15 16 17 18
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY L L L H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z THURSDAY...
LOCALIZED IFR CONDITIONS WILL BE POSSIBLE PRIMARILY THURSDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50
NEAR TERM...50
SHORT TERM...ARJ
LONG TERM...SL
AVIATION...50
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1055 AM CDT WED OCT 17 2012
.UPDATE...
SEE MORNING UPDATE.
&&
.DISCUSSION...
JUST A FEW CHANGES THIS MORNING AS HIGHER PW AIR LINGERS ALONG THE
COAST. RADAR IS SHOWING A FEW SHRA ALONG AND EAST OF HWY 59 SO
WILL ADD ISOLATED SHRA TODAY. WATER VAPOR IMAGERY SHOWS SOME DRIER
AIR WORKING EAST SO FEEL THE THREAT FOR SHRA WILL BE SHORT LIVED
AND PROBABLY END BY EARLY AFTERNOON. THAT SAID...THE LATEST RAP13
SHOWS SHRA CONTINUING ALL DAY OVER PARTS OF THE CENTRAL AND
EASTERN ZONES. WILL WATCH TRENDS AND HIGHER POPS MIGHT BE NEEDED
THIS AFTN IF THE RAP VERIFIES. WILL ALSO LOWER MAX TEMPS DUE TO A
COOL START...LINGERING CLOUD COVER AND MIXING FROM STRONGER WINDS.
NEW ZONES OUT BY 11 AM. 43
&&
.PREV DISCUSSION... /ISSUED 446 AM CDT WED OCT 17 2012/
DISCUSSION...
SHOULD MARKEDLY WARMER/DRIER ACROSS SE TX TODAY WITH THE PASSAGE
OF THAT STRONG SHORTWAVE LAST NIGHT. CLEARING SKIES/RETURN OF ON-
SHORE WINDS WILL HELP HI TEMPS TO TOP OFF INTO THE UPPER 80S AND
LOWER 90S THIS AFTN. HOWEVER RAIN CHCS STILL SET TO RETURN LATER
TONIGHT WITH THE PASSAGE OF THE COLD FRONT. FAVOURABLE UPPER JET
DYNAMICS ALONG WITH LIFT ALONG THE FRONT ITSELF SHOULD BE ENOUGH
FOR ISO/WIDELY SCT RAINS WITH FROPA. CURRENTLY THINKING THAT THE
HIGHER CHCS WILL BE OVER THE NERN CWA (WHERE LIFT IS STRONGEST).
FRONT SHOULD BE INTO THE NEARSHORE WATERS BY THURS MORNING AS WE
COOL OFF/DRY OUT ONCE AGAIN. A SLOW WARM UP THEN PROGGED THROUGH
THE END OF THE WEEK AS THE ASSOCIATED HIGH EVENTUALLY SETTLES IN
THE SERN U.S. THIS SHOULD ALLOW FOR THE RETURN OF ONSHORE WINDS/
LOW LEVEL MOISTURE OVER THE WEEKEND.
FAIRLY DECENT AGREEMENT WITH MODELS THROUGH THE START OF NEXT WK
AS A SOMEWHAT FLATTISH UPPER RIDGE DOMINATES THE PATTERN. BUT WE
ARE SEEING QUITE A BIT OF DISAGREEMENT FOR THE VERY LATTER STAGE
OF THE FCST CYCLE. ECMWF APPEARS TO BE MUCH MORE AGGRESSIVE/FAST
WITH THE APPROACH/DEVELOPMENT OF THE NEXT LONGWAVE TROF WHEN COM-
PARED TO THE GFS. SO WILL LIKELY KEEP WITH CURRENT EXTENDED FCST
FOR NOW AND SEE WHAT SHAKES OUT FOR LATER. 41
MARINE...
INCREASING SOUTHERLY FLOW TODAY WITH WINDS IN THE NEARSHORE
AREAS INCREASING TO 15 TO 20 KNOTS BEFORE RELAXING LATE THIS
AFTERNOON AND EVENING PRIOR TO THE ARRIVAL OF THE FRONT
THURSDAY MORNING. HAVE HOISTED A SCEC FOR THE NEARSHORE WATERS. WILL
HAVE TO KEEP AN EYE OUT FOR STRONG STORMS ALONG THE FRONTAL BOUNDARY
PASSAGE IN AND AROUND GALVESTON BAY AND HIGH ISLAND AREA WHERE MORE
FAVORABLE CAPE/SHEAR PROFILES SHOULD PREVAIL. AFTER THE FRONTAL
PASSAGE EXPECTING WINDS TO CLIMB TO 15 TO 20 KNOTS AND WILL LIKELY
NEED SCECS. WINDS GRADUALLY SWING TO THE SOUTHEAST AND EAST AS RIDGE
SLIDES EAST AND PARKS KEEPING A FAIRLY TIGHT GRADIENT OVER THE AREA
THIS WEEKEND.
45
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 88 58 80 52 82 / 10 10 10 10 10
HOUSTON (IAH) 87 65 82 54 83 / 10 20 20 10 10
GALVESTON (GLS) 83 73 81 66 80 / 10 20 20 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 7 PM CDT THIS EVENING
FOR THE FOLLOWING ZONES: 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...43
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
207 PM CDT WED OCT 17 2012
.DISCUSSION...
MAIN CONCERNS THIS FORECAST CYCLE ARE FIRST PERIOD CONVECTION WITH
SEVERE POTENTIAL. ELEVATED WINDS TODAY AND ON THURSDAY. ELEVATED
FIRE CONCERNS ON THURSDAY DUE TO WINDS AND LOWER RH VALUES. A
FIRE DANGER STATEMENT WILL PROBABLY BE ISSUED.
SEVERE STORM POTENTIAL REMAINS IN PLACE FOR LATER THIS AFTERNOON
TO EVENING. KLZK 18Z SOUNDING SHOWS SOME CAPPING IN 5K TO 10K
FT...WHILE WINDS MAINLY UNIDIRECTIONAL FROM THE S TO SW. PRECIP
WATER VALUE WAS 1.09 INCHES...MARGINAL INSTABILITY WITH LI OF
-1.0...WHILE HELICITY OF 362 M2/S2. CAPE WAS 360 J/KG. IF THE CAP
ERODES DUE TO MIXING THE CAPE VALUES WILL GO UP.
CLOUD COVER HAS HELD TEMPS DOWN TODAY WHILE MOISTURE LEVELS HAVE
INCREASED WITH DEW POINT TEMPS IN THE 60S OVER AR...WITH THE BEST
SURGE IN SW AR. CURRENTLY A SURFACE LOW HAD FORMED OVER EASTERN
OK...WITH THE OTHER SURFACE LOW IN THE UPPER PLAINS. A COLD FRONT
WAS SOUTH OVER EASTERN KS TO NEAR MO...WHILE TO EASTERN OK. THE
LOW LEVEL JET OF 30-50 KNOTS WAS STILL HELPING PULL MORE MOISTURE
INTO THE AREA. ALOFT THE UPPER TROUGH WAS DEEPENING INTO THE
SOUTHERN PLAINS WITH THE UPPER LOW OVER THE UPPER MID WEST. STRONG
NW UPPER FLOW WAS NOTED.
OVERALL TIMING OF THE FRONT HAS SLOWED JUST A LITTLE WITH AROUND
20Z NEAR NW AR...THEN MOVING AT A GOOD PASS THROUGH THE STATE...
AROUND 00Z TO 03Z IN CENTRAL SPOTS...AND 06Z TO 10Z EAST AND THEN
OUT OF AR BY 12Z. FROM THIS MORNING THERE IS STILL SOME UNCERTAINTY
IF ALL THE FACTORS WILL COME FOR ANY MORE THAN A SLIGHT CHANCE OF
SEVERE STORMS. STILL EXPECTING A SEVERE THREAT WITH THE BEST
CHANCE FOR A SQUALL LINE OF STORMS. SHORT RANGE MODELS SHOW
THIS...ESPECIALLY IN EAST CENTRAL TO EASTERN AR. DAMAGING WINDS
WITH THIS QUICK MOVING LINE ARE EXPECTED...WITH ISOLATED LARGE
HAIL. ISOLATED STRONG TO SEVERE STORMS AHEAD OF THE LINE WILL
REMAIN A POSSIBILITY BUT IS NOT THE FAVORED SCENARIO. AN ISOLATED
TORNADO THREAT WILL ALSO BE PRESENT DUE TO WIND DYNAMICS...ESPECIALLY
OVER SE AR WHERE SURFACE WINDS MAY BE A BIT MORE SE TO INCREASING
VEERING PROFILE. ALL STORMS ARE EXPECTED TO MOVE QUICKLY DUE TO
THE STRONG MID LEVEL STEERING FLOW FROM THE W TO NW.
&&
.SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT
FIRST PERIOD WILL STAY WITH THE HIGH POPS WITH SEVERE STORM
MENTION AS THE CONVECTION OVER EASTERN OK WITH WORK ITS WAY EAST
WITH THE BOUNDARY. HAVE SEEN A PREFRONTAL TROUGH DEVELOP SOME
CONVECTION AND THEN ADDITIONAL LINE ALONG AND WITH THE COLD FRONT.
WRF AND RR MODELS DEPICT THIS SCENARIO. THE CONVECTION SHOULD MOVE
ACROSS THE STATE FAIRLY QUICKLY WITH THE GOOD MID LEVEL WINDS AND
REACH EASTERN AR AROUND 06Z TO 10Z. QPF WITH THIS SYSTEM IS A BIT
UNCERTAIN DUE TO SPEED AND HOW MUCH MOISTURE WILL BE ADVECTED INTO
THE CONVECTION. WENT WITH HIGHEST FROM A 1/4 TO 3/4 INCH WITH A
FEW ISOLATED HIGHER SPOTS. SOME LOCATIONS WILL SEE ONLY SEE A FEW
TENTHS.
ON THURSDAY...THE SURFACE HIGH PRESSURE WILL BUILD IN BEHIND THE
FRONT AND BRING QUITE A DRY AND COOL AIR MASS. WINDS WILL BE
ELEVATED ESPECIALLY OVER NORTHERN AR TO CENTRAL...AND WITH MINIMUM RH
VALUES DROPPING INTO THE 20S...A FIRE WEATHER DANGER STATEMENT
WILL BE NEED. SOIL MOISTURE LEVELS ARE ABOVE CRITICAL VALUES AT
THIS TIME. DUE TO THE STRONG SURFACE AND UPPER SYSTEM...THE COOLER
AIR MASS WILL HOLD OVER THE AREA THROUGH SATURDAY. ANY CLOUDS ON
THURSDAY OVER NORTHERN AR WILL THIN INTO FRIDAY AND MOSTLY SUNNY
SKIES WILL BE SEEN FRIDAY AND SATURDAY. TEMPS WILL BE AT OR BELOW
THROUGH THE PERIOD THEN A WARMING TREND INTO NEXT WEEK.
&&
.LONG TERM...SUNDAY THROUGH WEDNESDAY...
A SOMEWHAT FLAT RIDGE WILL DEVELOP IN THE UPPER LEVEL FLOW ACROSS
THE REGION DURING THE EXTENDED TERM. A FEW SHORTWAVES WILL LIKELY
RIDE OVER THE RIDGE IN THE SWLY FLOW ALOFT. EXTENDED TERM MODELS ARE
IN DISAGREEMENT OVER THE HANDLING OF A SHORTWAVE DURING THIS TIME
FRAME...WITH THE GFS BEING MUCH WETTER AND GENERATING A WIDE AREA OF
PRECIP ACROSS THE NWRN PART OF THE STATE...WITH A DRIER ECMWF AND A
CANADIAN MODEL THAT IS SOMEWHAT IN BETWEEN.
AT THIS TIME I AM LEANING MORE TOWARD THE ECMWF SOLUTION BUT I AM
PUTTING SOME LOW POPS ACROSS THE NORTHERN/NWRN ZONES ON TUESDAY AND
TUESDAY NIGHT PER THE CANADIAN MODEL.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 45 69 43 69 / 80 10 0 0
CAMDEN AR 48 76 46 75 / 60 10 0 0
HARRISON AR 41 65 41 64 / 40 10 0 0
HOT SPRINGS AR 46 73 44 72 / 50 10 0 0
LITTLE ROCK AR 47 73 44 71 / 70 10 0 0
MONTICELLO AR 50 75 47 74 / 70 10 0 0
MOUNT IDA AR 45 71 43 70 / 40 10 0 0
MOUNTAIN HOME AR 41 66 41 65 / 60 10 0 0
NEWPORT AR 45 70 43 69 / 80 10 0 0
PINE BLUFF AR 48 74 45 73 / 70 10 0 0
RUSSELLVILLE AR 44 69 41 69 / 50 10 0 0
SEARCY AR 44 70 42 69 / 80 10 0 0
STUTTGART AR 46 72 43 71 / 80 10 0 0
&&
.LZK WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 8 PM CDT THIS EVENING FOR ARKANSAS-
BAXTER-BOONE-BRADLEY-CALHOUN-CLARK-CLEBURNE-CLEVELAND-CONWAY-
DALLAS-DESHA-DREW-FAULKNER-FULTON-GARLAND-GRANT-HOT SPRING-
INDEPENDENCE-IZARD-JACKSON-JEFFERSON-JOHNSON-LINCOLN-LOGAN-
LONOKE-MARION-MONROE-MONTGOMERY-NEWTON-OUACHITA-PERRY-PIKE-POLK-
POPE-PRAIRIE-PULASKI-SALINE-SCOTT-SEARCY-SHARP-STONE-VAN BUREN-
WHITE-WOODRUFF-YELL.
&&
$$
SHORT TERM...59 / LONG TERM...53
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
334 PM CDT WED OCT 17 2012
.DISCUSSION...
1230 PM CDT
MAIN FORECAST ISSUES/CONCERNS THIS AFTERNOON ARE WITH
SHOWER/THUNDERSTORM POTENTIAL AND SMALL BUT NOT ZERO CHANCE FOR
SEVERE WEATHER ACROSS THE SOUTHERN CWA...CENTRAL/EAST CENTRAL
ILLINOIS AND NORTHWEST INDIANA.
MADE SOME MINOR EDITS TO THE GRIDS...PRIMARILY WITH RESPECT TO THE
POP/WX GRIDS FOR THIS AFTERNOON SLOWING DOWN THE ONSET OF PRECIP.
WAA WHICH HAS BEEN PROMINENT ALL MORNING HAS BEEN STIFLED WITH THE
APPROACH OF THE LARGE SCALE TROUGH TO THE WEST. ALTHOUGH THIS WAA
HAS WEAKENED...SEVERAL WAVES OF ENERGY CONTINUE TO EJECT OUT
AHEAD OF THIS SYSTEM PROVIDING ENOUGH LIFT TO AID IN EXPANSIVE
CLOUD SHIELD TO THE SOUTHWEST OF THE CWA...TO CONTINUE SPREADING
NORTH AS WELL AS SOME ISOLATED SHOWER AND THUNDERSTORM
DEVELOPMENT. LATEST RADAR IMAGERY DEPICTING AN ISOLATED AREA OF
SHOWERS QUICKLY MOVING NORTHEAST ACROSS COOK COUNTY. AS A NARROW
RIBBON OF INSTABILITY IS POKING NORTH ACROSS NORTHERN
ILLINOIS...PER LATEST RAP ANALYSIS...A FEW LIGHTNING STRIKES HAVE
BEEN REPORTED. ALTHOUGH...AM NOT EXPECTING MUCH TO RESULT FROM
THESE SHOWERS/THUNDERSTORMS OUTSIDE OF BRIEF GUSTY WINDS AND BRIEF
DOWNPOURS. SO...HAVE PULLED BACK POPS ACROSS THE CWA THROUGH EARLY
AFTERNOON WITH THE EXPECTED DELAY IN PRECIP. ALTHOUGH WITH THE
APPROACH OF A FAIRLY STOUT VORT LOBE OUT AHEAD OF THIS DIGGING
TROUGH...FORCING WILL REALLY RAMP UP. THIS WILL HELP AN EXPANDING
AREA OF PRECIP TO SPREAD NORTHEAST ACROSS THE ENTIRE CWA LATE THIS
AFTERNOON THROUGH THE EVENING. SEVERAL FORCING MECHANISMS WILL
COME TOGETHER DURING THIS TIME FRAME AND PROVIDE STRONG FORCING TO
OCCUR OVERHEAD. WITH THIS STRONG FORCING COINCIDING WITH AN
INCREASE IN MOISTURE...LINGERING WEAK INSTABILITY...AND AN
INCREASE IN BULK SHEAR...HAVE BECOME A LITTLE MORE CONCERNED WITH
THUNDERSTORM POTENTIAL. ALTHOUGH THUNDERSTORMS WILL BE POSSIBLE
ACROSS THE ENTIRE CWA THIS AFTERNOON...PREVIOUS THINKING CONTINUES
WITH THE BETTER CHANCES FOR THUNDERSTORMS APPEARING TO BE SOUTH OF
INTERSTATE 80 LATE THIS AFTERNOON AND EVENING WITH A FEW POSSIBLY
BECOMING STRONG TO SEVERE...WITH STRONG WINDS THE PRIMARY
CONCERNS.
RODRIGUEZ
//PREV DISCUSSION...
330 AM CDT
PRIMARY FORECAST CONCERNS THIS GO AROUND INCLUDE THE IMPACTS OF THE
VIGOROUS TROUGH OVER THE NORTHERN PLAINS THAT GUIDANCE CONTINUE TO
DEVELOP INTO AN ABNORMALLY VIGOROUS UPPER LOW THAT WILL MEANDER
AROUND THE REGION FOR THE REST OF THE WORK WEEK.
ELEVATED ISOLATED WAA CONVECTION OVER THE CHICAGO AREA NOW SHOULD
HAVE LIFTED NORTHEAST INTO MICHIGAN BY SUNRISE...WITH SOME
OPPORTUNITY FOR SOME SUNSHINE EARLY THIS MORNING...MAINLY EASTERN
CWA. WHAT LIMITED SUNSHINE THERE IS THIS MORNING SHOULD QUICKLY GIVE
WAY TO OVERCAST CONDITIONS BY EARLY AFTERNOON WITH RAIN CHANCES
GRADUALLY RAMPING UP. SURFACE OBS AND GOES SOUNDER PWAT IMAGERY BOTH
SHOW A RELATIVE DEARTH IN MOISTURE IMMEDIATELY UPSTREAM OVER
MISSOURI WHICH SHOULD KEEP US MOSTLY DRY THIS MORNING...BUT LURKING
JUST TO THE WEST IS SECONDARY SURGE OF DEEPER MOISTURE IMMEDIATELY
IN ADVANCE OF THE STRENGTHENING COLD FRONT. STRONG SOUTHERLY FLOW
TODAY WILL RESULT IN RAPID NORTHEASTWARD TRANSPORT OF THIS DEEPER
MOISTURE AND MODELS ARE BREAKING OUT SCATTERED PRECIPITATION BY
EARLY AFTERNOON IN RESPONSE TO THE STRONG PUSH OF HIGHER LOW LEVEL
THETA-E AIR MASS.
MORE ORGANIZED FRONTAL AND POST-FRONTAL PRECIPITATION LOOKS SLATED
TO ARRIVE IN OUR WESTERN CWA LATE THIS AFTERNOON INTO EARLY THIS
EVENING. A SUBSTANTIAL INCREASE IN THE COVERAGE AND INTENSITY OF THE
PRECIPITATION IS EXPECTED IN THE 21-03Z TIME FRAME AS THE DEEP
SYNOPTIC SCALE FORCING SPREADS SOUTHEAST AND BEGINS TO ENCOUNTER THE
DEEPER MOISTURE ADVECTING NORTHEAST INTO THE REGION. FORCING LOOKS
TO BE VERY IMPRESSIVE AS VIGOROUS SHORTWAVE PIVOTING AROUND THE BASE
OF THE INTENSIFYING UPPER LOW LEADS TO ENTIRE UPPER TROUGH/LOW
TAKING ON NEGATIVE TILT WITH ILLINOIS COUPLING OF STRONG UPPER LEVEL
DIVERGENCE AND VERY STRONG LOW LEVEL FRONTOGENESIS LEADING TO VERY
STRONG UPWARD VERTICAL VELOCITIES AND BLOSSOMING AREA OF PRECIP.
MOST MODELS GENERALLY KEEP THE INSTABILITY SOUTH OF OUR CWA...THOUGH
A FEW SREF MEMBERS DO BRING UPWARDS OF 250 J/KG OF SBCAPE INTO OUR
SOUTHERN CWA THIS EVENING. WHAT WE LACK IN INSTABILITY WILL
CERTAINLY BE MADE UP FOR WITH FORCING AND HAVE MAINTAINED CHANCE OF
THUNDER THIS AFTERNOON AND EVENING. WHILE LIGHTNING MAY NOT BE
OVERLY PREVALENT...WE COULD SEE A BAND OF STRONG FORCING LOW TOPPED
CONVECTION THAT COULD STILL TRANSPORT SOME STRONGER WINDS TO THE
SURFACE THIS EVENING...ESPECIALLY SOUTHERN CWA WHERE THERE COULD BE
A BIT OF SB INSTABILITY. THE STRONG FORCING AND SEASONABLY HIGH
PWATS SHOULD RESULT IN A FAIRLY RESPECTABLE RAINFALL ACROSS THE CWA
WITH WIDESPREAD 1 TO 2 THIRD OF A INCH TOTALS LIKELY...AND LOCALIZED
AMOUNTS OF AN INCH POSSIBLE.
TAKING A QUICK STEP BACK...TEMPS TODAY WILL BE TRICKY AS 08Z TEMPS
ARE STILL IN THE MID-UPPER 60S IN CHICAGO AND UPPER 50S/LOW 60S
OUTSIDE THE CITY. WHILE SUNSHINE SHOULD BE LIMITED TODAY...SUCH A
WARM START TO THE DAY DOES ARGUE FOR GOING A BIT ABOVE GUIDANCE FOR
HIGHS TODAY WITH PARTICULARLY EASTERN CWA STANDING A REASONABLE SHOT
AT CLIMBING ABOVE 70F AGAIN. AFTER AN UNSEASONABLY BALMY (ALMOST
SUMMER-LIKE NIGHT) TUES NIGHT...STRONG COLD AIR ADVECTION IN THE
WAKE OF THE FRONT TONIGHT WILL PROVIDE THE AREA WITH A COLD HARD
SLAP OF AUTUMNAL REALITY WITH READINGS BACK INTO THE 40S BY THURS
MORNING ALONG WITH MODERATELY BRISK WEST WINDS ADDING MORE OF A
CHILL TO THE AIR.
COULD LITERALLY CUT AND PASTE LAST NIGHT`S AFD INTO THIS AFD
REGARDING THURSDAY AND FRIDAY`S FORECAST. MASSIVE AND UNSEASONABLY
STRONG/COLD ATMOSPHERIC GYRE WILL SET-UP SHOP OVER THE WESTERN GREAT
LAKES RESULTING IN PERIODIC SHOWERY CONDITIONS THURSDAY INTO
FRIDAY...WITH STEEP LAPSE RATES AND COLD TEMPS ALOFT RESULT IN THE
POTENTIAL FOR SOME GRAUPEL AND MAYBE EVEN A BIT RUMBLE OR TWO OF
THUNDER. COVERAGE AND INTENSITY OF THE SHOWERS WILL BE GREATEST
DURING THE AFTERNOON/EVENING HOURS AND TIED TO INDIVIDUAL VORT LOBES
PIVOTING AROUND THE UPPER LOW. WHILE THERE WILL BE A DIURNAL MAXIMA
OF SHOWER ACTIVITY...SOME SHOWERS WILL CONTINUE THROUGH THE
NIGHT...ESPECIALLY NEAR MORE VIGOROUS VORTS. CONSIDERABLE CLOUD
COVER AND VERY COLD NATURE OF THE LOW WILL RESULT IN MUCH BELOW
AVERAGE TEMPS THURS AND FRIDAY WITH HIGHS STRUGGLING TO REACH 50F
BOTH BOTH DAYS.
MEDIUM RANGE MODELS REMAIN LOCKSTEP WITH EACH OTHER IN THIS UPPER
LOW MOVING EAST UNCHARACTERISTICALLY QUICK FOR SUCH A STRONG/BIG CUT
OFF. THIS HASTY EXIT IS THE RESULT OF YET ANOTHER UNUSUALLY STRONG
UPPER TROUGH/CUT OFF LOW PROGGED TO TAKE SHAPE OVER THE PAC NW
RESULTING IN DOWNSTREAM AMPLIFICATION OF THE RIDGE OVER OUR AREA. IN
FACT...MEDIUM RANGE MODELS ARE IN GREAT AGREEMENT IN BUILDING A
RESPECTABLE UPPER RIDGE INTO THE REGION WITH H8 TEMPS SURGING TO 1-2
SIGMA ABOVE AVERAGE BY EARLY NEXT WEEK. ALL INDICATIONS ARE AT THIS
POINT THAT WE COULD SEE READINGS BACK ABOVE 70 DEGREES BY EARLY NEXT
WEEK.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* TIMING OF COLD FRONTAL PASSAGE AND ASSOCIATED WIND SHIFT
TONIGHT.
* PERIODS OF SHRA/TSRA REST OF AFTERNOON AND THIS EVENING.
* LOCAL MVFR CEILING AND/OR VISIBILITY WITH SHRA/TSRA BECOMING
PREVAILING MVFR CEILINGS BY EARLY EVENING.
* THREAT OF SHRA/TSRA AND ASSOCIATED MVFR CONDITIONS INCREASING
DURING LATER THU MORNING INTO AFTERNOON.
TRS
//DISCUSSION...UPDATED 18Z...
INCREASING LOW LEVEL MOISTURE HAS QUICKLY ADVECTED NORTH-NORTHEAST
FROM THE MID MS VALLEY ACROSS NORTHERN IL AND FAR NW IN WITH MID-
UPPER 50S DEW POINTS JUST UPSTREAM OVER NE MO AND CENTRAL IL.
AS AN UPPER LOW...WITHIN THE UPPER TROUGH FROM MANITOBA SSE TO
NORTHERN OK...CONTINUES TO DEVELOP AND PROGRESS SOUTHEASTWARD OVER
THE UPPER MS VALLEY THE REST OF THE AFTERNOON AND THIS EVENING
SHRA AND TSRA EXPECTED TO BECOME MORE NUMEROUS AS INCREASINGLY
STRONG ISENTROPIC LIFT SPREADS E AND NE ACROSS THE MID MS VALLEY.
MODELS IN FAIRLY GOOD AGREEMENT IN ROTATING THE MID LEVEL TROUGH
TO NW AND E CENTRAL IL BY 06Z AND PUSHING THE COLD FRONT...
CURRENTLY CURVING FROM E CENTRAL MN AND W CENTRAL WI TO E CENTRAL
AND SE IA AND THEN TO NW AND W CENTRAL MO...E ACROSS THE MID MS
VALLEY AND TO IL BY MIDNIGHT. SOME LIGHTER SHOWERS MAY PERSIST
BEHIND THE COLD FRONT TIL THE MID LEVEL TROUGH AXIS PASSES BY
THEN SUBSIDENCE AND DRYING PREVAIL OVERNIGHT.
DURING THE DAY THU A NEARLY VERTICALLY STACKED LOW IS PROGGED TO
SETTLE SLOWLY SE FROM SOUTHEASTERN MN TO SW WI AND NE IA BY 00Z
FRI. COLD TEMPERATURES IN THE MID AND UPPER LEVELS ASSOCIATED WITH
THE STACKED LOW COLD POOL...ALONG WITH DEEP CYCLONIC FLOW...WILL
ENCOURAGE CU TO DEVELOP AND TO GROW TO A DEEP ENOUGH DEPTH TO
SUPPORT SHOWERS AND SOME TS WITH ELEVATED CAPE ACROSS THE AREA.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
*HIGH CONFIDENCE IN INCREASING COVERAGE OF SHRA AND TSRA THROUGH
REST OF AFTERNOON INTO THIS EVENING.
*MODERATE CONFIDENCE IN TIMING OF PERIODS OF SHRA AND TSRA REST OF
AFTERNOON AND THIS EVENING.
*MODERATE CONFIDENCE IN TIME OF COLD FRONT PASSAGE/WINDSHIFT TO
WITHIN +/- 1 HR.
*MODERATE CONFIDENCE IN TIMING OF LOCAL MVFR CEILINGS AND
VISIBILITIES BECOMING PREVAILING BY THIS EVENING.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
* THURSDAY NIGHT...RAIN WITH MVFR CIGS/VIS POSSIBLE.
* FRIDAY...RAIN LIKELY WITH CHANCE TSRA IN THE AFTERNOON. MVFR
CIGS/VIS POSSIBLE.
* SATURDAY AND SUNDAY...VFR. WX NIL.
* MONDAY AND TUESDAY...CHANCE OF SHRA.
KREIN
&&
.MARINE...
331 PM CDT
AN AREA OF DEEPENING LOW PRESSURE AVERAGING IS LOCATED OVER
NORTHERN MINNESOTA THIS AFTERNOON. SOUTHWEST OF THIS LOW...OVER
THE DAKOTAS...WINDS HAVE BEEN GUSTING ABOVE 50 KT. THE LOW WILL
SLIDE INTO WISCONSIN TONIGHT. A COLD FRONT TRAILING SOUTH FROM THE
LOW WILL SWEEP FROM SOUTHWEST TO NORTHEAST ACROSS LAKE MICHIGAN
TONIGHT AND EARLY TOMORROW. AHEAD OF THE FRONT TONIGHT...SOUTH TO
SOUTHEAST WINDS COULD POSSIBLY BE MUCH STRONGER THAN
FORECAST...PERHAPS OVER 40 KT...AND A GALE WARNING MAY YET BE
NEEDED FOR THE OVERNIGHT HOURS. TALLER VESSELS ARE LIKELY TO SEE
AT LEAST OCCASIONAL GALE FORCE GUSTS TONIGHT. THE UNCERTAINTY
COMES FROM THE CLOSE PROXIMITY OF THE LOW TO THE LAKE...WHICH CAN
RESULT IN LOWER WINDS...AND THE WARMTH OF THE AIR BEING LIFTED
OVER THE COOLER WATERS. IN CONTRAST...THE STRONG GUSTS OVER THE
DAKOTAS ARE IN A REGION OF COLD AIR MOVING OVER WARMER GROUND.
VERY SLOWLY THE LOW WILL THEN DRIFT EAST ACROSS LAKE MICHIGAN BY
FRIDAY AND INTO THE EASTERN GREAT LAKES BY SATURDAY AS IT WEAKENS
SLIGHTLY. MEANWHILE...A WEAK RIDGE OF HIGH PRESSURE WILL MOVE
EAST OVER THE MISSISSIPPI VALLEY FRIDAY NIGHT AND SATURDAY. THE
RIDGE WILL CONTINUE EAST TO THE EASTERN GREAT LAKES AND OHIO
VALLEY SATURDAY NIGHT.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM THURSDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
311 PM CDT WED OCT 17 2012
.DISCUSSION...
1230 PM CDT
MAIN FORECAST ISSUES/CONCERNS THIS AFTERNOON ARE WITH
SHOWER/THUNDERSTORM POTENTIAL AND SMALL BUT NOT ZERO CHANCE FOR
SEVERE WEATHER ACROSS THE SOUTHERN CWA...CENTRAL/EAST CENTRAL
ILLINOIS AND NORTHWEST INDIANA.
MADE SOME MINOR EDITS TO THE GRIDS...PRIMARILY WITH RESPECT TO THE
POP/WX GRIDS FOR THIS AFTERNOON SLOWING DOWN THE ONSET OF PRECIP.
WAA WHICH HAS BEEN PROMINENT ALL MORNING HAS BEEN STIFLED WITH THE
APPROACH OF THE LARGE SCALE TROUGH TO THE WEST. ALTHOUGH THIS WAA
HAS WEAKENED...SEVERAL WAVES OF ENERGY CONTINUE TO EJECT OUT
AHEAD OF THIS SYSTEM PROVIDING ENOUGH LIFT TO AID IN EXPANSIVE
CLOUD SHIELD TO THE SOUTHWEST OF THE CWA...TO CONTINUE SPREADING
NORTH AS WELL AS SOME ISOLATED SHOWER AND THUNDERSTORM
DEVELOPMENT. LATEST RADAR IMAGERY DEPICTING AN ISOLATED AREA OF
SHOWERS QUICKLY MOVING NORTHEAST ACROSS COOK COUNTY. AS A NARROW
RIBBON OF INSTABILITY IS POKING NORTH ACROSS NORTHERN
ILLINOIS...PER LATEST RAP ANALYSIS...A FEW LIGHTNING STRIKES HAVE
BEEN REPORTED. ALTHOUGH...AM NOT EXPECTING MUCH TO RESULT FROM
THESE SHOWERS/THUNDERSTORMS OUTSIDE OF BRIEF GUSTY WINDS AND BRIEF
DOWNPOURS. SO...HAVE PULLED BACK POPS ACROSS THE CWA THROUGH EARLY
AFTERNOON WITH THE EXPECTED DELAY IN PRECIP. ALTHOUGH WITH THE
APPROACH OF A FAIRLY STOUT VORT LOBE OUT AHEAD OF THIS DIGGING
TROUGH...FORCING WILL REALLY RAMP UP. THIS WILL HELP AN EXPANDING
AREA OF PRECIP TO SPREAD NORTHEAST ACROSS THE ENTIRE CWA LATE THIS
AFTERNOON THROUGH THE EVENING. SEVERAL FORCING MECHANISMS WILL
COME TOGETHER DURING THIS TIME FRAME AND PROVIDE STRONG FORCING TO
OCCUR OVERHEAD. WITH THIS STRONG FORCING COINCIDING WITH AN
INCREASE IN MOISTURE...LINGERING WEAK INSTABILITY...AND AN
INCREASE IN BULK SHEAR...HAVE BECOME A LITTLE MORE CONCERNED WITH
THUNDERSTORM POTENTIAL. ALTHOUGH THUNDERSTORMS WILL BE POSSIBLE
ACROSS THE ENTIRE CWA THIS AFTERNOON...PREVIOUS THINKING CONTINUES
WITH THE BETTER CHANCES FOR THUNDERSTORMS APPEARING TO BE SOUTH OF
INTERSTATE 80 LATE THIS AFTERNOON AND EVENING WITH A FEW POSSIBLY
BECOMING STRONG TO SEVERE...WITH STRONG WINDS THE PRIMARY
CONCERNS.
RODRIGUEZ
//PREV DISCUSSION...
330 AM CDT
PRIMARY FORECAST CONCERNS THIS GO AROUND INCLUDE THE IMPACTS OF THE
VIGOROUS TROUGH OVER THE NORTHERN PLAINS THAT GUIDANCE CONTINUE TO
DEVELOP INTO AN ABNORMALLY VIGOROUS UPPER LOW THAT WILL MEANDER
AROUND THE REGION FOR THE REST OF THE WORK WEEK.
ELEVATED ISOLATED WAA CONVECTION OVER THE CHICAGO AREA NOW SHOULD
HAVE LIFTED NORTHEAST INTO MICHIGAN BY SUNRISE...WITH SOME
OPPORTUNITY FOR SOME SUNSHINE EARLY THIS MORNING...MAINLY EASTERN
CWA. WHAT LIMITED SUNSHINE THERE IS THIS MORNING SHOULD QUICKLY GIVE
WAY TO OVERCAST CONDITIONS BY EARLY AFTERNOON WITH RAIN CHANCES
GRADUALLY RAMPING UP. SURFACE OBS AND GOES SOUNDER PWAT IMAGERY BOTH
SHOW A RELATIVE DEARTH IN MOISTURE IMMEDIATELY UPSTREAM OVER
MISSOURI WHICH SHOULD KEEP US MOSTLY DRY THIS MORNING...BUT LURKING
JUST TO THE WEST IS SECONDARY SURGE OF DEEPER MOISTURE IMMEDIATELY
IN ADVANCE OF THE STRENGTHENING COLD FRONT. STRONG SOUTHERLY FLOW
TODAY WILL RESULT IN RAPID NORTHEASTWARD TRANSPORT OF THIS DEEPER
MOISTURE AND MODELS ARE BREAKING OUT SCATTERED PRECIPITATION BY
EARLY AFTERNOON IN RESPONSE TO THE STRONG PUSH OF HIGHER LOW LEVEL
THETA-E AIR MASS.
MORE ORGANIZED FRONTAL AND POST-FRONTAL PRECIPITATION LOOKS SLATED
TO ARRIVE IN OUR WESTERN CWA LATE THIS AFTERNOON INTO EARLY THIS
EVENING. A SUBSTANTIAL INCREASE IN THE COVERAGE AND INTENSITY OF THE
PRECIPITATION IS EXPECTED IN THE 21-03Z TIME FRAME AS THE DEEP
SYNOPTIC SCALE FORCING SPREADS SOUTHEAST AND BEGINS TO ENCOUNTER THE
DEEPER MOISTURE ADVECTING NORTHEAST INTO THE REGION. FORCING LOOKS
TO BE VERY IMPRESSIVE AS VIGOROUS SHORTWAVE PIVOTING AROUND THE BASE
OF THE INTENSIFYING UPPER LOW LEADS TO ENTIRE UPPER TROUGH/LOW
TAKING ON NEGATIVE TILT WITH ILLINOIS COUPLING OF STRONG UPPER LEVEL
DIVERGENCE AND VERY STRONG LOW LEVEL FRONTOGENESIS LEADING TO VERY
STRONG UPWARD VERTICAL VELOCITIES AND BLOSSOMING AREA OF PRECIP.
MOST MODELS GENERALLY KEEP THE INSTABILITY SOUTH OF OUR CWA...THOUGH
A FEW SREF MEMBERS DO BRING UPWARDS OF 250 J/KG OF SBCAPE INTO OUR
SOUTHERN CWA THIS EVENING. WHAT WE LACK IN INSTABILITY WILL
CERTAINLY BE MADE UP FOR WITH FORCING AND HAVE MAINTAINED CHANCE OF
THUNDER THIS AFTERNOON AND EVENING. WHILE LIGHTNING MAY NOT BE
OVERLY PREVALENT...WE COULD SEE A BAND OF STRONG FORCING LOW TOPPED
CONVECTION THAT COULD STILL TRANSPORT SOME STRONGER WINDS TO THE
SURFACE THIS EVENING...ESPECIALLY SOUTHERN CWA WHERE THERE COULD BE
A BIT OF SB INSTABILITY. THE STRONG FORCING AND SEASONABLY HIGH
PWATS SHOULD RESULT IN A FAIRLY RESPECTABLE RAINFALL ACROSS THE CWA
WITH WIDESPREAD 1 TO 2 THIRD OF A INCH TOTALS LIKELY...AND LOCALIZED
AMOUNTS OF AN INCH POSSIBLE.
TAKING A QUICK STEP BACK...TEMPS TODAY WILL BE TRICKY AS 08Z TEMPS
ARE STILL IN THE MID-UPPER 60S IN CHICAGO AND UPPER 50S/LOW 60S
OUTSIDE THE CITY. WHILE SUNSHINE SHOULD BE LIMITED TODAY...SUCH A
WARM START TO THE DAY DOES ARGUE FOR GOING A BIT ABOVE GUIDANCE FOR
HIGHS TODAY WITH PARTICULARLY EASTERN CWA STANDING A REASONABLE SHOT
AT CLIMBING ABOVE 70F AGAIN. AFTER AN UNSEASONABLY BALMY (ALMOST
SUMMER-LIKE NIGHT) TUES NIGHT...STRONG COLD AIR ADVECTION IN THE
WAKE OF THE FRONT TONIGHT WILL PROVIDE THE AREA WITH A COLD HARD
SLAP OF AUTUMNAL REALITY WITH READINGS BACK INTO THE 40S BY THURS
MORNING ALONG WITH MODERATELY BRISK WEST WINDS ADDING MORE OF A
CHILL TO THE AIR.
COULD LITERALLY CUT AND PASTE LAST NIGHT`S AFD INTO THIS AFD
REGARDING THURSDAY AND FRIDAY`S FORECAST. MASSIVE AND UNSEASONABLY
STRONG/COLD ATMOSPHERIC GYRE WILL SET-UP SHOP OVER THE WESTERN GREAT
LAKES RESULTING IN PERIODIC SHOWERY CONDITIONS THURSDAY INTO
FRIDAY...WITH STEEP LAPSE RATES AND COLD TEMPS ALOFT RESULT IN THE
POTENTIAL FOR SOME GRAUPEL AND MAYBE EVEN A BIT RUMBLE OR TWO OF
THUNDER. COVERAGE AND INTENSITY OF THE SHOWERS WILL BE GREATEST
DURING THE AFTERNOON/EVENING HOURS AND TIED TO INDIVIDUAL VORT LOBES
PIVOTING AROUND THE UPPER LOW. WHILE THERE WILL BE A DIURNAL MAXIMA
OF SHOWER ACTIVITY...SOME SHOWERS WILL CONTINUE THROUGH THE
NIGHT...ESPECIALLY NEAR MORE VIGOROUS VORTS. CONSIDERABLE CLOUD
COVER AND VERY COLD NATURE OF THE LOW WILL RESULT IN MUCH BELOW
AVERAGE TEMPS THURS AND FRIDAY WITH HIGHS STRUGGLING TO REACH 50F
BOTH BOTH DAYS.
MEDIUM RANGE MODELS REMAIN LOCKSTEP WITH EACH OTHER IN THIS UPPER
LOW MOVING EAST UNCHARACTERISTICALLY QUICK FOR SUCH A STRONG/BIG CUT
OFF. THIS HASTY EXIT IS THE RESULT OF YET ANOTHER UNUSUALLY STRONG
UPPER TROUGH/CUT OFF LOW PROGGED TO TAKE SHAPE OVER THE PAC NW
RESULTING IN DOWNSTREAM AMPLIFICATION OF THE RIDGE OVER OUR AREA. IN
FACT...MEDIUM RANGE MODELS ARE IN GREAT AGREEMENT IN BUILDING A
RESPECTABLE UPPER RIDGE INTO THE REGION WITH H8 TEMPS SURGING TO 1-2
SIGMA ABOVE AVERAGE BY EARLY NEXT WEEK. ALL INDICATIONS ARE AT THIS
POINT THAT WE COULD SEE READINGS BACK ABOVE 70 DEGREES BY EARLY NEXT
WEEK.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* TIMING OF COLD FRONTAL PASSAGE AND ASSOCIATED WIND SHIFT
TONIGHT.
* PERIODS OF SHRA/TSRA REST OF AFTERNOON AND THIS EVENING.
* LOCAL MVFR CEILING AND/OR VISIBILITY WITH SHRA/TSRA BECOMING
PREVAILING MVFR CEILINGS BY EARLY EVENING.
* THREAT OF SHRA/TSRA AND ASSOCIATED MVFR CONDITIONS INCREASING
DURING LATER THU MORNING INTO AFTERNOON.
TRS
//DISCUSSION...UPDATED 18Z...
INCREASING LOW LEVEL MOISTURE HAS QUICKLY ADVECTED NORTH-NORTHEAST
FROM THE MID MS VALLEY ACROSS NORTHERN IL AND FAR NW IN WITH MID-
UPPER 50S DEW POINTS JUST UPSTREAM OVER NE MO AND CENTRAL IL.
AS AN UPPER LOW...WITHIN THE UPPER TROUGH FROM MANITOBA SSE TO
NORTHERN OK...CONTINUES TO DEVELOP AND PROGRESS SOUTHEASTWARD OVER
THE UPPER MS VALLEY THE REST OF THE AFTERNOON AND THIS EVENING
SHRA AND TSRA EXPECTED TO BECOME MORE NUMEROUS AS INCREASINGLY
STRONG ISENTROPIC LIFT SPREADS E AND NE ACROSS THE MID MS VALLEY.
MODELS IN FAIRLY GOOD AGREEMENT IN ROTATING THE MID LEVEL TROUGH
TO NW AND E CENTRAL IL BY 06Z AND PUSHING THE COLD FRONT...
CURRENTLY CURVING FROM E CENTRAL MN AND W CENTRAL WI TO E CENTRAL
AND SE IA AND THEN TO NW AND W CENTRAL MO...E ACROSS THE MID MS
VALLEY AND TO IL BY MIDNIGHT. SOME LIGHTER SHOWERS MAY PERSIST
BEHIND THE COLD FRONT TIL THE MID LEVEL TROUGH AXIS PASSES BY
THEN SUBSIDENCE AND DRYING PREVAIL OVERNIGHT.
DURING THE DAY THU A NEARLY VERTICALLY STACKED LOW IS PROGGED TO
SETTLE SLOWLY SE FROM SOUTHEASTERN MN TO SW WI AND NE IA BY 00Z
FRI. COLD TEMPERATURES IN THE MID AND UPPER LEVELS ASSOCIATED WITH
THE STACKED LOW COLD POOL...ALONG WITH DEEP CYCLONIC FLOW...WILL
ENCOURAGE CU TO DEVELOP AND TO GROW TO A DEEP ENOUGH DEPTH TO
SUPPORT SHOWERS AND SOME TS WITH ELEVATED CAPE ACROSS THE AREA.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
*HIGH CONFIDENCE IN INCREASING COVERAGE OF SHRA AND TSRA THROUGH
REST OF AFTERNOON INTO THIS EVENING.
*MODERATE CONFIDENCE IN TIMING OF PERIODS OF SHRA AND TSRA REST OF
AFTERNOON AND THIS EVENING.
*MODERATE CONFIDENCE IN TIME OF COLD FRONT PASSAGE/WINDSHIFT TO
WITHIN +/- 1 HR.
*MODERATE CONFIDENCE IN TIMING OF LOCAL MVFR CEILINGS AND
VISIBILITIES BECOMING PREVAILING BY THIS EVENING.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
* THURSDAY NIGHT...RAIN WITH MVFR CIGS/VIS POSSIBLE.
* FRIDAY...RAIN LIKELY WITH CHANCE TSRA IN THE AFTERNOON. MVFR
CIGS/VIS POSSIBLE.
* SATURDAY AND SUNDAY...VFR. WX NIL.
* MONDAY AND TUESDAY...CHANCE OF SHRA.
KREIN
&&
.MARINE...
320 AM CDT
BRISK SOUTH WINDS WILL PERSIST THROUGH WED AS LOW PRESSURE OVER
SOUTH DAKOTA AND ANOTHER LOW JUST WEST OF LAKE WINNIPEG WILL
MERGE INTO A SINGLE LOW PRESSURE SYSTEM OVER NORTHERN MINNESOTA
BY THIS EVENING. WINDS SHOULD BE IN THE 30KT RANGE OVER THE OPEN
WATERS...BUT A FEW GALE FORCE GUSTS TO 35KT ARE NOT OUT OF THE
QUESTION. A STRONG COLD FRONT ASSOCIATED WITH THIS LOW WILL SWEEP
EAST ACROSS LAKE MICHIGAN WEDNESDAY NIGHT...SHIFTING WINDS TO MORE
SOUTHWESTERLY. WINDS WILL DIMINISH AS THE LOW SLOWLY DRIFTS EAST
ACROSS LAKE MICHIGAN FRIDAY AND INTO THE EASTERN GREAT LAKES BY
SATURDAY. WINDS WILL FURTHER WEAKEN AS A WEAK RIDGE OF HIGH
PRESSURE MOVES ACROSS THE MISSISSIPPI VALLEY FRIDAY NIGHT AND
SATURDAY. THE RIDGE WILL PUSH EAST OF LAKE MICHIGAN SATURDAY
NIGHT.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM THURSDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
219 PM CDT WED OCT 17 2012
.DISCUSSION...
1230 PM CDT
MAIN FORECAST ISSUES/CONCERNS THIS AFTERNOON ARE WITH
SHOWER/THUNDERSTORM POTENTIAL AND SMALL BUT NOT ZERO CHANCE FOR
SEVERE WEATHER ACROSS THE SOUTHERN CWA...CENTRAL/EAST CENTRAL
ILLINOIS AND NORTHWEST INDIANA.
MADE SOME MINOR EDITS TO THE GRIDS...PRIMARILY WITH RESPECT TO THE
POP/WX GRIDS FOR THIS AFTERNOON SLOWING DOWN THE ONSET OF PRECIP.
WAA WHICH HAS BEEN PROMINENT ALL MORNING HAS BEEN STIFLED WITH THE
APPROACH OF THE LARGE SCALE TROUGH TO THE WEST. ALTHOUGH THIS WAA
HAS WEAKENED...SEVERAL WAVES OF ENERGY CONTINUE TO EJECT OUT
AHEAD OF THIS SYSTEM PROVIDING ENOUGH LIFT TO AID IN EXPANSIVE
CLOUD SHIELD TO THE SOUTHWEST OF THE CWA...TO CONTINUE SPREADING
NORTH AS WELL AS SOME ISOLATED SHOWER AND THUNDERSTORM
DEVELOPMENT. LATEST RADAR IMAGERY DEPICTING AN ISOLATED AREA OF
SHOWERS QUICKLY MOVING NORTHEAST ACROSS COOK COUNTY. AS A NARROW
RIBBON OF INSTABILITY IS POKING NORTH ACROSS NORTHERN
ILLINOIS...PER LATEST RAP ANALYSIS...A FEW LIGHTNING STRIKES HAVE
BEEN REPORTED. ALTHOUGH...AM NOT EXPECTING MUCH TO RESULT FROM
THESE SHOWERS/THUNDERSTORMS OUTSIDE OF BRIEF GUSTY WINDS AND BRIEF
DOWNPOURS. SO...HAVE PULLED BACK POPS ACROSS THE CWA THROUGH EARLY
AFTERNOON WITH THE EXPECTED DELAY IN PRECIP. ALTHOUGH WITH THE
APPROACH OF A FAIRLY STOUT VORT LOBE OUT AHEAD OF THIS DIGGING
TROUGH...FORCING WILL REALLY RAMP UP. THIS WILL HELP AN EXPANDING
AREA OF PRECIP TO SPREAD NORTHEAST ACROSS THE ENTIRE CWA LATE THIS
AFTERNOON THROUGH THE EVENING. SEVERAL FORCING MECHANISMS WILL
COME TOGETHER DURING THIS TIME FRAME AND PROVIDE STRONG FORCING TO
OCCUR OVERHEAD. WITH THIS STRONG FORCING COINCIDING WITH AN
INCREASE IN MOISTURE...LINGERING WEAK INSTABILITY...AND AN
INCREASE IN BULK SHEAR...HAVE BECOME A LITTLE MORE CONCERNED WITH
THUNDERSTORM POTENTIAL. ALTHOUGH THUNDERSTORMS WILL BE POSSIBLE
ACROSS THE ENTIRE CWA THIS AFTERNOON...PREVIOUS THINKING CONTINUES
WITH THE BETTER CHANCES FOR THUNDERSTORMS APPEARING TO BE SOUTH OF
INTERSTATE 80 LATE THIS AFTERNOON AND EVENING WITH A FEW POSSIBLY
BECOMING STRONG TO SEVERE...WITH STRONG WINDS THE PRIMARY
CONCERNS.
RODRIGUEZ
//PREV DISCUSSION...
330 AM CDT
PRIMARY FORECAST CONCERNS THIS GO AROUND INCLUDE THE IMPACTS OF THE
VIGOROUS TROUGH OVER THE NORTHERN PLAINS THAT GUIDANCE CONTINUE TO
DEVELOP INTO AN ABNORMALLY VIGOROUS UPPER LOW THAT WILL MEANDER
AROUND THE REGION FOR THE REST OF THE WORK WEEK.
ELEVATED ISOLATED WAA CONVECTION OVER THE CHICAGO AREA NOW SHOULD
HAVE LIFTED NORTHEAST INTO MICHIGAN BY SUNRISE...WITH SOME
OPPORTUNITY FOR SOME SUNSHINE EARLY THIS MORNING...MAINLY EASTERN
CWA. WHAT LIMITED SUNSHINE THERE IS THIS MORNING SHOULD QUICKLY GIVE
WAY TO OVERCAST CONDITIONS BY EARLY AFTERNOON WITH RAIN CHANCES
GRADUALLY RAMPING UP. SURFACE OBS AND GOES SOUNDER PWAT IMAGERY BOTH
SHOW A RELATIVE DEARTH IN MOISTURE IMMEDIATELY UPSTREAM OVER
MISSOURI WHICH SHOULD KEEP US MOSTLY DRY THIS MORNING...BUT LURKING
JUST TO THE WEST IS SECONDARY SURGE OF DEEPER MOISTURE IMMEDIATELY
IN ADVANCE OF THE STRENGTHENING COLD FRONT. STRONG SOUTHERLY FLOW
TODAY WILL RESULT IN RAPID NORTHEASTWARD TRANSPORT OF THIS DEEPER
MOISTURE AND MODELS ARE BREAKING OUT SCATTERED PRECIPITATION BY
EARLY AFTERNOON IN RESPONSE TO THE STRONG PUSH OF HIGHER LOW LEVEL
THETA-E AIR MASS.
MORE ORGANIZED FRONTAL AND POST-FRONTAL PRECIPITATION LOOKS SLATED
TO ARRIVE IN OUR WESTERN CWA LATE THIS AFTERNOON INTO EARLY THIS
EVENING. A SUBSTANTIAL INCREASE IN THE COVERAGE AND INTENSITY OF THE
PRECIPITATION IS EXPECTED IN THE 21-03Z TIME FRAME AS THE DEEP
SYNOPTIC SCALE FORCING SPREADS SOUTHEAST AND BEGINS TO ENCOUNTER THE
DEEPER MOISTURE ADVECTING NORTHEAST INTO THE REGION. FORCING LOOKS
TO BE VERY IMPRESSIVE AS VIGOROUS SHORTWAVE PIVOTING AROUND THE BASE
OF THE INTENSIFYING UPPER LOW LEADS TO ENTIRE UPPER TROUGH/LOW
TAKING ON NEGATIVE TILT WITH ILLINOIS COUPLING OF STRONG UPPER LEVEL
DIVERGENCE AND VERY STRONG LOW LEVEL FRONTOGENESIS LEADING TO VERY
STRONG UPWARD VERTICAL VELOCITIES AND BLOSSOMING AREA OF PRECIP.
MOST MODELS GENERALLY KEEP THE INSTABILITY SOUTH OF OUR CWA...THOUGH
A FEW SREF MEMBERS DO BRING UPWARDS OF 250 J/KG OF SBCAPE INTO OUR
SOUTHERN CWA THIS EVENING. WHAT WE LACK IN INSTABILITY WILL
CERTAINLY BE MADE UP FOR WITH FORCING AND HAVE MAINTAINED CHANCE OF
THUNDER THIS AFTERNOON AND EVENING. WHILE LIGHTNING MAY NOT BE
OVERLY PREVALENT...WE COULD SEE A BAND OF STRONG FORCING LOW TOPPED
CONVECTION THAT COULD STILL TRANSPORT SOME STRONGER WINDS TO THE
SURFACE THIS EVENING...ESPECIALLY SOUTHERN CWA WHERE THERE COULD BE
A BIT OF SB INSTABILITY. THE STRONG FORCING AND SEASONABLY HIGH
PWATS SHOULD RESULT IN A FAIRLY RESPECTABLE RAINFALL ACROSS THE CWA
WITH WIDESPREAD 1 TO 2 THIRD OF A INCH TOTALS LIKELY...AND LOCALIZED
AMOUNTS OF AN INCH POSSIBLE.
TAKING A QUICK STEP BACK...TEMPS TODAY WILL BE TRICKY AS 08Z TEMPS
ARE STILL IN THE MID-UPPER 60S IN CHICAGO AND UPPER 50S/LOW 60S
OUTSIDE THE CITY. WHILE SUNSHINE SHOULD BE LIMITED TODAY...SUCH A
WARM START TO THE DAY DOES ARGUE FOR GOING A BIT ABOVE GUIDANCE FOR
HIGHS TODAY WITH PARTICULARLY EASTERN CWA STANDING A REASONABLE SHOT
AT CLIMBING ABOVE 70F AGAIN. AFTER AN UNSEASONABLY BALMY (ALMOST
SUMMER-LIKE NIGHT) TUES NIGHT...STRONG COLD AIR ADVECTION IN THE
WAKE OF THE FRONT TONIGHT WILL PROVIDE THE AREA WITH A COLD HARD
SLAP OF AUTUMNAL REALITY WITH READINGS BACK INTO THE 40S BY THURS
MORNING ALONG WITH MODERATELY BRISK WEST WINDS ADDING MORE OF A
CHILL TO THE AIR.
COULD LITERALLY CUT AND PASTE LAST NIGHT`S AFD INTO THIS AFD
REGARDING THURSDAY AND FRIDAY`S FORECAST. MASSIVE AND UNSEASONABLY
STRONG/COLD ATMOSPHERIC GYRE WILL SET-UP SHOP OVER THE WESTERN GREAT
LAKES RESULTING IN PERIODIC SHOWERY CONDITIONS THURSDAY INTO
FRIDAY...WITH STEEP LAPSE RATES AND COLD TEMPS ALOFT RESULT IN THE
POTENTIAL FOR SOME GRAUPEL AND MAYBE EVEN A BIT RUMBLE OR TWO OF
THUNDER. COVERAGE AND INTENSITY OF THE SHOWERS WILL BE GREATEST
DURING THE AFTERNOON/EVENING HOURS AND TIED TO INDIVIDUAL VORT LOBES
PIVOTING AROUND THE UPPER LOW. WHILE THERE WILL BE A DIURNAL MAXIMA
OF SHOWER ACTIVITY...SOME SHOWERS WILL CONTINUE THROUGH THE
NIGHT...ESPECIALLY NEAR MORE VIGOROUS VORTS. CONSIDERABLE CLOUD
COVER AND VERY COLD NATURE OF THE LOW WILL RESULT IN MUCH BELOW
AVERAGE TEMPS THURS AND FRIDAY WITH HIGHS STRUGGLING TO REACH 50F
BOTH BOTH DAYS.
MEDIUM RANGE MODELS REMAIN LOCKSTEP WITH EACH OTHER IN THIS UPPER
LOW MOVING EAST UNCHARACTERISTICALLY QUICK FOR SUCH A STRONG/BIG CUT
OFF. THIS HASTY EXIT IS THE RESULT OF YET ANOTHER UNUSUALLY STRONG
UPPER TROUGH/CUT OFF LOW PROGGED TO TAKE SHAPE OVER THE PAC NW
RESULTING IN DOWNSTREAM AMPLIFICATION OF THE RIDGE OVER OUR AREA. IN
FACT...MEDIUM RANGE MODELS ARE IN GREAT AGREEMENT IN BUILDING A
RESPECTABLE UPPER RIDGE INTO THE REGION WITH H8 TEMPS SURGING TO 1-2
SIGMA ABOVE AVERAGE BY EARLY NEXT WEEK. ALL INDICATIONS ARE AT THIS
POINT THAT WE COULD SEE READINGS BACK ABOVE 70 DEGREES BY EARLY NEXT
WEEK.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* TIMING OF COLD FRONTAL PASSAGE AND ASSOCIATED WIND SHIFT
TONIGHT.
* SHRA/TSRA BECOMING MORE NUMEROUS DURING MID-LATE AFTERNOON
AND PERSISTING INTO EVENING.
* LOCAL MVFR CEILING AND/OR VISIBILITY WITH SHRA/TSRA BECOMING
PREVAILING MVFR CEILINGS FOR A PERIOD FOLLOWING FROPA.
* THREAT OF SHRA/TSRA AND ASSOCIATED MVFR CONDITIONS INCREASING
DURING LATER MORNING INT AFTERNOON.
TRS
//DISCUSSION...UPDATED 18Z...
INCREASING LOW LEVEL MOISTURE HAS QUICKLY ADVECTED NORTH-NORTHEAST
FROM THE MID MS VALLEY ACROSS NORTHERN IL AND FAR NW IN WITH MID-
UPPER 50S DEW POINTS JUST UPSTREAM OVER NE MO AND CENTRAL IL.
AS AN UPPER LOW...WITHIN THE UPPER TROUGH FROM MANITOBA SSE TO
NORTHERN OK...CONTINUES TO DEVELOP AND PROGRESS SOUTHEASTWARD OVER
THE UPPER MS VALLEY THE REST OF THE AFTERNOON AND THIS EVENING
SHRA AND TSRA EXPECTED TO BECOME MORE NUMEROUS AS INCREASINGLY
STRONG ISENTROPIC LIFT SPREADS E AND NE ACROSS THE MID MS VALLEY.
MODELS IN FAIRLY GOOD AGREEMENT IN ROTATING THE MID LEVEL TROUGH
TO NW AND E CENTRAL IL BY 06Z AND PUSHING THE COLD FRONT...
CURRENTLY CURVING FROM E CENTRAL MN AND W CENTRAL WI TO E CENTRAL
AND SE IA AND THEN TO NW AND W CENTRAL MO...E ACROSS THE MID MS
VALLEY AND TO IL BY MIDNIGHT. SOME LIGHTER SHOWERS MAY PERSIST
BEHIND THE COLD FRONT TIL THE MID LEVEL TROUGH AXIS PASSES BY
THEN SUBSIDENCE AND DRYING PREVAIL OVERNIGHT.
DURING THE DAY THU A NEARLY VERTICALLY STACKED LOW IS PROGGED TO
SETTLE SLOWLY SE FROM SOUTHEASTERN MN TO SW WI AND NE IA BY 00Z
FRI. COLD TEMPERATURES IN THE MID AND UPPER LEVELS ASSOCIATED WITH
THE STACKED LOW COLD POOL...ALONG WITH DEEP CYCLONIC FLOW...WILL
ENCOURAGE CU TO DEVELOP AND TO GROW TO A DEEP ENOUGH DEPTH TO
SUPPORT SHOWERS AND SOME TS WITH ELEVATED CAPE ACROSS THE AREA.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
*HIGH CONFIDENCE IN INCREASING COVERAGE OF SHRA AND TS THROUGH
REST OF AFTERNOON INTO THIS EVENING.
*MODERATE CONFIDENCE IN TIME OF COLD FRONT PASSAGE/WINDSHIFT TO
WITHIN +/- 1 HR.
*MODERATE CONFIDENCE IN TIMING OF LOCAL MVFR CEILINGS AND
VISIBILITIES BECOMING PREVAILING BY THIS EVENING.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
* THURSDAY NIGHT...RAIN WITH MVFR CIGS/VIS POSSIBLE.
* FRIDAY...RAIN LIKELY WITH CHANCE TSRA IN THE AFTERNOON. MVFR
CIGS/VIS POSSIBLE.
* SATURDAY AND SUNDAY...VFR. WX NIL.
* MONDAY AND TUESDAY...CHANCE OF SHRA.
KREIN
&&
.MARINE...
320 AM CDT
BRISK SOUTH WINDS WILL PERSIST THROUGH WED AS LOW PRESSURE OVER
SOUTH DAKOTA AND ANOTHER LOW JUST WEST OF LAKE WINNIPEG WILL
MERGE INTO A SINGLE LOW PRESSURE SYSTEM OVER NORTHERN MINNESOTA
BY THIS EVENING. WINDS SHOULD BE IN THE 30KT RANGE OVER THE OPEN
WATERS...BUT A FEW GALE FORCE GUSTS TO 35KT ARE NOT OUT OF THE
QUESTION. A STRONG COLD FRONT ASSOCIATED WITH THIS LOW WILL SWEEP
EAST ACROSS LAKE MICHIGAN WEDNESDAY NIGHT...SHIFTING WINDS TO MORE
SOUTHWESTERLY. WINDS WILL DIMINISH AS THE LOW SLOWLY DRIFTS EAST
ACROSS LAKE MICHIGAN FRIDAY AND INTO THE EASTERN GREAT LAKES BY
SATURDAY. WINDS WILL FURTHER WEAKEN AS A WEAK RIDGE OF HIGH
PRESSURE MOVES ACROSS THE MISSISSIPPI VALLEY FRIDAY NIGHT AND
SATURDAY. THE RIDGE WILL PUSH EAST OF LAKE MICHIGAN SATURDAY
NIGHT.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM THURSDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
417 PM CDT WED OCT 17 2012
.UPDATE...
UPDATED POPS AND WEATHER TO REFLECT THE CURRENT RADAR POSITION OF
WIDESPREAD SHOWERS FOR THIS AFTERNOON AND EARLY EVENING.
ERVIN
&&
.PREV DISCUSSION... /ISSUED 331 PM CDT WED OCT 17 2012/
SYNOPSIS...
12Z UA ANALYSIS HAS 850MB LOWS ON THE NORTH SHORE OF LAKE WINNIPEG
AND IN NORTHWEST MINNESOTA. AN 850MB COLD FRONT RAN FROM THE
MINNESOTA LOW INTO SOUTHEAST NEW MEXICO WITH A TROF FROM SOUTHERN
MINNESOTA INTO SOUTH TEXAS. SATELLITE/RADAR TRENDS SHOWS EXTENSIVE
LOW AND MID LEVEL CLOUDS WITH STRONG CONVECTION ACROSS MISSOURI
AND MORE SCATTERED CONVECTION ACROSS IOWA/ILLINOIS.
18Z SFC ANALYSIS HAS A LOW EAST OF KFAR WITH THE COLD FRONT SOUTH
INTO SOUTHEAST KANSAS. TWO MESO LOWS WERE IN SOUTHWEST MISSOURI
AND NORTHEAST OKLAHOMA. A PRE-FRONTAL TROF RAN FROM JUST EAST OF
KMSP TO ABOUT KIRK. DEW POINTS AHEAD OF THE COLD FRONT WERE IN THE
50S AND 60S WITH 20S AND 30S BEHIND THE COLD FRONT IN THE PLAINS.
SHORT TERM...TONIGHT AND THURSDAY
THE CURRENT PICTURE AT MID AFTERNOON HAS MID LEVEL FORCING OR A
WEAK VORT MAX PUSHING A SLUG OF MAINLY SHRA ACROSS THE CWFA. A
MUCH STRONGER VORT MAX IS ROTATING NORTHEAST ACROSS MISSOURI. IF
THE TRENDS OF THE RAP ARE CORRECT...THERE SHOULD BE A BAND OF
ENHANCED CONVECTION THAT DEVELOPS LATE THIS AFTERNOON IN THE
SOUTHEAST QUADRANT OF THE CWFA AND ROTATES NORTHEAST.
THIS BAND OF CONVECTION WILL BE ACROSS ROUGHLY THE EASTERN 40
PERCENT OF THE CWFA DURING THE EARLY EVENING HOURS BEFORE EXITING
THE CWFA. SOME LINGERING SHRA SHOULD THEN BE SEEN IN THE THE MID
AND LATE EVENING HOURS BEFORE ENDING.
AFTER MIDNIGHT THERE SHOULD BE SOME CLEARING OF THE CLOUDS WITH
DRY CONDITIONS AS CONDENSATION PRESSURE DEFICITS RISE
CONSIDERABLY. CONDENSATION PRESSURE DEFICITS IN THE 850-700MB
LAYER COLLAPSE AGAIN ACROSS THE CWFA PRIOR TO SUNRISE BUT THE
1000-850MB LAYER CONDENSATION PRESSURE DEFICITS ONLY LOWER
SLIGHTLY. THUS MOST OF THE AREA SHOULD REMAIN DRY AFTER MIDNIGHT
BUT SOME SPRINKLES MIGHT ENTER THE FAR NORTHWEST PART OF THE CWFA
JUST PRIOR TO DAWN.
THURSDAY...WRAP AROUND CLOUDS/PRECIP MOVE SOUTHEAST THROUGH THE
CWFA DURING THE MORNING HOURS. STEEP LAPSE RATES WILL AID IN
DEVELOPING NEW DIURNAL CLOUDS IN AREAS THAT WERE PARTIALLY CLEAR
AT SUNRISE. SCATTERED SHRA WILL BECOME MORE NUMEROUS DURING THE
DAY AS A VORT MAX ROTATES THROUGH AND INCREASES THE LIFT. THE
FREEZING LEVEL IS 3.0-3.5 KFT AGL PLUS/MINUS 700 FT DEPENDING ON
LOCAL ELEVATION ABOVE SEA LEVEL. HOWEVER...THE LOWEST 2 KFT ABOVE
THE GROUND REMAINS ABOVE FREEZING. THUS IN THE STRONGER SHOWERS
THE POTENTIAL DOES EXIST FOR SOME SMALL GRAUPEL TO DEVELOP THAT
REACHES THE GROUND.
TEMPERATURES WILL REMAIN IN THE 40S FOR MUCH OF THE DAY BUT THE
SOUTHEAST THIRD TO 40 PERCENT OF THE CWFA MAY MANAGE TO GET INTO
THE LOWER 50S. REGARDLESS...IT WILL BE A COLD RAW DAY WHEN THE
WIND IS FACTORED IN. 08
LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
UPPER LOW PROGGED TO EXIT INTO THE GREAT LAKES REGION BY FRI NGT.
UNTIL THEN WILL SEE CONSIDERABLE CLOUDINESS ALONG WITH BOUTS OF
LIGHT RAIN OR SHOWERS... AS SPOKES OF ENERGY ROTATE DOWN THE
BACKSIDE OF THE LOW. CLOUDS WILL ACT AS BLANKET AND LIMIT DIURNAL
SWINGS INTO FRI. CLOUD FORECAST CHALLENGING FRI NGT INTO SAT WITH
OVERALL INCOMING SUBSIDENCE IN WAKE OF DEPARTING LOW SUPPORTIVE OF
CLEARING... BUT NAM BUFR SOUNDINGS DEPICT A LOT OF LOW LEVEL
MOISTURE TRAPPED BENEATH SUBSIDENCE INVERSION. TIME OF YEAR WITH
LOWER SUN ANGLE BECOMING MORE FAVORABLE FOR THESE SCENARIOS AND
NUDGED TOWARD A MORE PESSIMISTIC SKY COVER FRI NGT THUS STAYING AT
OR ABOVE WARM SIDE OF GUIDANCE ON LOWS.
SAT-SUN... DRY WITH WARMING TREND TO ABOVE NORMAL TEMPS BY SUN AS
NEXT SIGNIFICANT TROUGH PUSHES INTO THE PACIFIC NORTHWEST... WHICH
RESULTS IN DOWNSTREAM AMPLIFICATION OF UPPER RIDGE OVER THE REGION.
MON-WED... ABOVE NORMAL TEMPS GENERALLY SUGGESTED WITH DEEP TROUGHING
OVER THE WESTERN CONUS AND SW FLOW ALOFT. SW FLOW COUPLED WITH FRONTAL
ZONE WAVERING NEARBY WILL RESULT IN OCCASIONAL RAIN CHCS AS WELL
DURING THE PERIOD. THE FIRST RAIN CHCS APPEAR TO ARRIVE AS EARLY AS
MONDAY MORNING WITH MORE ROBUST LOW LEVEL WARM ADVECTION REGIME.
OTHERWISE... IT IS DIFFICULT TO PIN DOWN RAIN CHCS THEREAFTER WITH
MODELS OFFERING DIFFERENCES ON LOCATION OF THE FRONT AND TIMING OF
UPPER LEVEL DISTURBANCES EJECTING FROM WESTERN TROUGH.
TRANSITION TO SIGNIFICANTLY COLDER REGIME IS DEPICTED BY ECMWF AND GFS
BY THE END OF NEXT WEEK INTO NEXT WEEKEND. 05
AVIATION... /ISSUED 1247 PM CDT WED OCT 17 2012/
A COLD FRONT WILL SWEEP THROUGH EASTERN IOWA AND ILLINOIS IN THE
18Z/17 TO 00Z/18 TIME FRAME. VFR WX IS GENERALLY EXPECTED WITH
SPRINKLES OR SHRA. ALONG/EAST OF THE MISSISSIPPI RIVER ISOLD TSRA
WILL BE POSSIBLE THAT ARE EXPECTED TO BECOME MORE NUMEROUS AFT
21Z. VFR CONDITIONS ARE EXPECTED BUT THERE MAY BE BRIEF INCURSIONS
OF MVFR CONDITIONS WITH ANY TSRA OR STRONGER SHRA. AFT 00Z/18 VFR
CONDITIONS ARE EXPECTED. CIGS WILL LOWER AGAIN AFT 12Z/18 BUT
SHOULD REMAIN VFR. 08
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
331 PM CDT WED OCT 17 2012
.SYNOPSIS...
12Z UA ANALYSIS HAS 850MB LOWS ON THE NORTH SHORE OF LAKE WINNIPEG
AND IN NORTHWEST MINNESOTA. AN 850MB COLD FRONT RAN FROM THE
MINNESOTA LOW INTO SOUTHEAST NEW MEXICO WITH A TROF FROM SOUTHERN
MINNESOTA INTO SOUTH TEXAS. SATELLITE/RADAR TRENDS SHOWS EXTENSIVE
LOW AND MID LEVEL CLOUDS WITH STRONG CONVECTION ACROSS MISSOURI
AND MORE SCATTERED CONVECTION ACROSS IOWA/ILLINOIS.
18Z SFC ANALYSIS HAS A LOW EAST OF KFAR WITH THE COLD FRONT SOUTH
INTO SOUTHEAST KANSAS. TWO MESO LOWS WERE IN SOUTHWEST MISSOURI
AND NORTHEAST OKLAHOMA. A PRE-FRONTAL TROF RAN FROM JUST EAST OF
KMSP TO ABOUT KIRK. DEW POINTS AHEAD OF THE COLD FRONT WERE IN THE
50S AND 60S WITH 20S AND 30S BEHIND THE COLD FRONT IN THE PLAINS.
&&
.SHORT TERM...TONIGHT AND THURSDAY
THE CURRENT PICTURE AT MID AFTERNOON HAS MID LEVEL FORCING OR A
WEAK VORT MAX PUSHING A SLUG OF MAINLY SHRA ACROSS THE CWFA. A
MUCH STRONGER VORT MAX IS ROTATING NORTHEAST ACROSS MISSOURI. IF
THE TRENDS OF THE RAP ARE CORRECT...THERE SHOULD BE A BAND OF
ENHANCED CONVECTION THAT DEVELOPS LATE THIS AFTERNOON IN THE
SOUTHEAST QUADRANT OF THE CWFA AND ROTATES NORTHEAST.
THIS BAND OF CONVECTION WILL BE ACROSS ROUGHLY THE EASTERN 40
PERCENT OF THE CWFA DURING THE EARLY EVENING HOURS BEFORE EXITING
THE CWFA. SOME LINGERING SHRA SHOULD THEN BE SEEN IN THE THE MID
AND LATE EVENING HOURS BEFORE ENDING.
AFTER MIDNIGHT THERE SHOULD BE SOME CLEARING OF THE CLOUDS WITH
DRY CONDITIONS AS CONDENSATION PRESSURE DEFICITS RISE
CONSIDERABLY. CONDENSATION PRESSURE DEFICITS IN THE 850-700MB
LAYER COLLAPSE AGAIN ACROSS THE CWFA PRIOR TO SUNRISE BUT THE
1000-850MB LAYER CONDENSATION PRESSURE DEFICITS ONLY LOWER
SLIGHTLY. THUS MOST OF THE AREA SHOULD REMAIN DRY AFTER MIDNIGHT
BUT SOME SPRINKLES MIGHT ENTER THE FAR NORTHWEST PART OF THE CWFA
JUST PRIOR TO DAWN.
THURSDAY...WRAP AROUND CLOUDS/PRECIP MOVE SOUTHEAST THROUGH THE
CWFA DURING THE MORNING HOURS. STEEP LAPSE RATES WILL AID IN
DEVELOPING NEW DIURNAL CLOUDS IN AREAS THAT WERE PARTIALLY CLEAR
AT SUNRISE. SCATTERED SHRA WILL BECOME MORE NUMEROUS DURING THE
DAY AS A VORT MAX ROTATES THROUGH AND INCREASES THE LIFT. THE
FREEZING LEVEL IS 3.0-3.5 KFT AGL PLUS/MINUS 700 FT DEPENDING ON
LOCAL ELEVATION ABOVE SEA LEVEL. HOWEVER...THE LOWEST 2 KFT ABOVE
THE GROUND REMAINS ABOVE FREEZING. THUS IN THE STRONGER SHOWERS
THE POTENTIAL DOES EXIST FOR SOME SMALL GRAUPEL TO DEVELOP THAT
REACHES THE GROUND.
TEMPERATURES WILL REMAIN IN THE 40S FOR MUCH OF THE DAY BUT THE
SOUTHEAST THIRD TO 40 PERCENT OF THE CWFA MAY MANAGE TO GET INTO
THE LOWER 50S. REGARDLESS...IT WILL BE A COLD RAW DAY WHEN THE
WIND IS FACTORED IN. 08
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
UPPER LOW PROGGED TO EXIT INTO THE GREAT LAKES REGION BY FRI NGT.
UNTIL THEN WILL SEE CONSIDERABLE CLOUDINESS ALONG WITH BOUTS OF
LIGHT RAIN OR SHOWERS... AS SPOKES OF ENERGY ROTATE DOWN THE
BACKSIDE OF THE LOW. CLOUDS WILL ACT AS BLANKET AND LIMIT DIURNAL
SWINGS INTO FRI. CLOUD FORECAST CHALLENGING FRI NGT INTO SAT WITH
OVERALL INCOMING SUBSIDENCE IN WAKE OF DEPARTING LOW SUPPORTIVE OF
CLEARING... BUT NAM BUFR SOUNDINGS DEPICT A LOT OF LOW LEVEL
MOISTURE TRAPPED BENEATH SUBSIDENCE INVERSION. TIME OF YEAR WITH
LOWER SUN ANGLE BECOMING MORE FAVORABLE FOR THESE SCENARIOS AND
NUDGED TOWARD A MORE PESSIMISTIC SKY COVER FRI NGT THUS STAYING AT
OR ABOVE WARM SIDE OF GUIDANCE ON LOWS.
SAT-SUN... DRY WITH WARMING TREND TO ABOVE NORMAL TEMPS BY SUN AS
NEXT SIGNIFICANT TROUGH PUSHES INTO THE PACIFIC NORTHWEST... WHICH
RESULTS IN DOWNSTREAM AMPLIFICATION OF UPPER RIDGE OVER THE REGION.
MON-WED... ABOVE NORMAL TEMPS GENERALLY SUGGESTED WITH DEEP TROUGHING
OVER THE WESTERN CONUS AND SW FLOW ALOFT. SW FLOW COUPLED WITH FRONTAL
ZONE WAVERING NEARBY WILL RESULT IN OCCASIONAL RAIN CHCS AS WELL
DURING THE PERIOD. THE FIRST RAIN CHCS APPEAR TO ARRIVE AS EARLY AS
MONDAY MORNING WITH MORE ROBUST LOW LEVEL WARM ADVECTION REGIME.
OTHERWISE... IT IS DIFFICULT TO PIN DOWN RAIN CHCS THEREAFTER WITH
MODELS OFFERING DIFFERENCES ON LOCATION OF THE FRONT AND TIMING OF
UPPER LEVEL DISTURBANCES EJECTING FROM WESTERN TROUGH.
TRANSITION TO SIGNIFICANTLY COLDER REGIME IS DEPICTED BY ECMWF AND GFS
BY THE END OF NEXT WEEK INTO NEXT WEEKEND. 05
&&
.AVIATION... /ISSUED 1247 PM CDT WED OCT 17 2012/
A COLD FRONT WILL SWEEP THROUGH EASTERN IOWA AND ILLINOIS IN THE
18Z/17 TO 00Z/18 TIME FRAME. VFR WX IS GENERALLY EXPECTED WITH
SPRINKLES OR SHRA. ALONG/EAST OF THE MISSISSIPPI RIVER ISOLD TSRA
WILL BE POSSIBLE THAT ARE EXPECTED TO BECOME MORE NUMEROUS AFT
21Z. VFR CONDITIONS ARE EXPECTED BUT THERE MAY BE BRIEF INCURSIONS
OF MVFR CONDITIONS WITH ANY TSRA OR STRONGER SHRA. AFT 00Z/18 VFR
CONDITIONS ARE EXPECTED. CIGS WILL LOWER AGAIN AFT 12Z/18 BUT
SHOULD REMAIN VFR. 08
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
08/05
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1247 PM CDT WED OCT 17 2012
.UPDATE...
ANOTHER UPDATE HAS BEEN DONE TO THE FCST. THE POSSIBILITY OF A
NONLINEAR EVENT IS NOW A BIT HIGHER THAN IT WAS A FEW HOURS AGO.
BASED ON SUGGESTED TRENDS FROM THE RAP AND RADAR...THE
DEVELOPMENT OF ISOLATED TSRA ARE POSSIBLE PRIOR TO MID AFTERNOON
FROM APPROXIMATELY THE MISS RIVER ON EAST. THE MOISTURE BEING
ADVECTED NORTHWARD IS STARTING TO WIN AGAINST THE DRY AIR WITH
MORE VIRGA SHOWING UP ON RADAR.
TRENDS IN THE RAP MODEL ARE SUGGESTING A THETA E GRADIENT IS
DEVELOPING JUST WEST OF THE MISSISSIPPI. THIS GRADIENT ALONG WITH
WHAT DIFFERENTIAL HEATING OCCURRED MAY BE JUST ENOUGH TO INITIATE
A FEW ISOLATE TSRA. TSRA THAT HAVE DEVELOPED FROM EASTERN MISSOURI
INTO CENTRAL ILLINOIS SHOULD WEAKEN A LITTLE AS THEY ENCOUNTER
SLIGHTLY DRIER AIR.
THERE SHOULD STILL BE A RESPECTABLE BAND OF CONVECTION THAT FIRES
MID TO LATE AFTERNOON ALONG/EAST OF THE MISSISSIPPI RIVER. THE
TIMING AND PLACEMENT OF SAID BAND AS OF YET IS NOT FULLY KNOWN BUT
SHOULD BECOME OBVIOUS OVER THE NEXT FEW HOURS. ..08..
&&
.AVIATION...
A COLD FRONT WILL SWEEP THROUGH EASTERN IOWA AND ILLINOIS IN THE
18Z/17 TO 00Z/18 TIME FRAME. VFR WX IS GENERALLY EXPECTED WITH
SPRINKLES OR SHRA. ALONG/EAST OF THE MISSISSIPPI RIVER ISOLD TSRA
WILL BE POSSIBLE THAT ARE EXPECTED TO BECOME MORE NUMEROUS AFT
21Z. VFR CONDITIONS ARE EXPECTED BUT THERE MAY BE BRIEF INCURSIONS
OF MVFR CONDITIONS WITH ANY TSRA OR STRONGER SHRA. AFT 00Z/18 VFR
CONDITIONS ARE EXPECTED. CIGS WILL LOWER AGAIN AFT 12Z/18 BUT
SHOULD REMAIN VFR. ..08..
&&
.PREV DISCUSSION... /ISSUED 1053 AM CDT WED OCT 17 2012/
UPDATE...
A FAIRLY SIGNIFICANT REVISION TO THE FCST HAS BEEN DONE.
HOWEVER...THE MODELS ARE HINTING THAT A NONLINEAR EVENT MAY BE IN
THE OFFERING. IF CORRECT...THERE COULD BE ADDITIONAL
CHANGES...POSSIBLY SIGNIFICANT...TO THE FCST.
CURRENT DATA SHOWS THE WAA PRECIP IS SLOWLY EVAPORATING DUE TO THE
INITIALLY DRY ATMOSPHERE ACROSS THE AREA. WHAT IS BEING SUGGESTED
BY THE RAP AND THE 12Z WRF IS THAT THE INITIAL PLUME OF 6-7C 850MB
MOISTURE OVER THE AREA...PER 12Z RAOBS...WILL SHIFT EAST THE
REMAINDER OF THE MORNING. THUS THERE SHOULD BE MORE DRY AIR ALOFT
TO GENERATE MAINLY VIRGA/SPRINKLES WITH SCATTERED SHRA. THIS
SCENARIO IS PARTLY SUPPORTED BY A VORT MAX ROTATING THROUGH THE
AREA PER THE RAP/WRF THIS MORNING WITH LIFT INCREASING AND THEN
DECREASING.
THIS AFTERNOON THE MAIN FORCING WITH THE MAINLY POST FRONTAL
PRECIPITATION WILL MOVE INTO THE WESTERN CWFA SO WILL CONTINUE
WITH LIKELY POPS THERE. THE RAP/WRF CONTINUE TO PUSH MOISTURE
NORTHWARD SO THE REMAINDER OF THE CWFA SHOULD START SEEING MORE
SCATTERED SHRA DEVELOPMENT FOR THE FIRST PART OF THE AFTERNOON.
LATE THIS AFTERNOON THE LIFT AND HEAVY RAIN TOOLS WHEN APPLIED TO
THE RAP/WRF ARE SUGGESTING A FAIRLY SUBSTANTIAL BAND OF CONVECTION
COULD FIRE ROUGHLY ALONG OR JUST EAST OF THE MISSISSIPPI AND MOVE
EAST. SINCE MOISTURE WOULD BE MAXIMIZING JUST PAST PEAK HEATING
WITH THE FRONT IN ROUGHLY THE SAME AREA...THIS SCENARIO HAS SOME
PLAUSIBILITY TO IT. IF CORRECT...THE BETTER PRECIPITATION TOTALS
WOULD BE OVER THE EASTERN THIRD OF THE CWFA. ..08..
PREV DISCUSSION... /ISSUED 340 AM CDT WED OCT 17 2012/
SYNOPSIS...
THE BEGINNINGS OF ANOTHER MUCH NEEDED RAIN EVENT IS DEVELOPING OUT
OVER THE PLAINS THIS MORNING. A STRONG SURFACE LOW OVER EASTERN
SOUTH DAKOTA HAS A STRONG COLD FRONT DRAPED SOUTHWEST FROM IT ACROSS
NEBRASKA AND NORTHWEST KANSAS AND BACK INTO COLORADO. THERE IS ALSO
A WARM FRONT...WHICH PASSED THROUGH THE FORECAST AREA YESTERDAY
DRAPED ACROSS SOUTHERN MINNESOTA AND WISCONSIN. SOUTH WINDS HAVE
STAYED UP VERY NICELY OVERNIGHT AND TEMPERATURES AS OF 3 AM ARE
STILL IN THE MID 50S TO LOW 60S...HIGHLY UNUSUAL FOR THIS TIME OF
YEAR. SHOWERS HAVE ALREADY DEVELOPED OVER WESTERN IOWA...SOUTHWEST
MINNESOTA...EASTERN SOUTH DAKOTA...NEBRASKA AND KANSAS. AT UPPER
LEVELS WE HAVE A NICE PLUME OF HIGHER DEWPOINT AIR AT 850MB
EXTENDING FROM TEXAS UP INTO CENTRAL IOWA AND EVEN SOUTHERN
MINNESOTA...ASSOCIATED WITH A NICE LOW LEVEL FLOW OF 25-30KTS. THAT
THIS INCOMING SYSTEM IS VERY POWERFUL IS INDICATED BY THE DRAMATIC
HEIGHT FALLS AT 500MB OVER THE NORTHERN ROCKIES...AND THE STRONG JET
OF 140KTS+ IMPINGING ON THE WEST OREGON COAST. LE
SHORT TERM...TODAY AND TONIGHT...
THERE IS MUCH TO LOOK AT WITH THIS VERY DYNAMIC SYSTEM THAT WILL
MOVE OVER THE FORECAST AREA IN THE NEXT 24 HOURS. CANNOT WRITE ALL
THAT ONE WOULD LIKE WITH THIS MUCH TO LOOK AT...BUT HERE GOES.
THIS MORNING THIS SYSTEM WILL CONTINUE TO MOVE OUR DIRECTION...AS
THE UPPER LEVEL FEATURES BEGIN TO INTERACT MORE STRONGLY WITH THE
DEEPER MOISTURE NOW AVAILABLE OVER THE FORECAST AREA. THIS MORNING
IN THE WARM SECTOR AIRMASS WE SHOULD GET SOME CONVECTIVE
SHOWERS...SIMILAR TO WHAT WE ARE NOW SEEING OVER CENTRAL IOWA.
THESE SHOWERS SHOULD AFFECT MAINLY THE WESTERN PORTIONS OF THE
FORECAST AREA DUE TO THE DIMINISHING MOISTURE TO THE EAST...AND
THE BETTER ISENTROPIC LIFT TO THE WEST. THE BETTER DYNAMICS ARE
STILL TO COME...AND ARE EXPECTED TO MOVE ACROSS THE FORECAST AREA
THIS AFTERNOON AND EVENING. THE SURFACE LOW NOW OVER EASTERN SOUTH
DAKOTA WILL SWING NORTHEAST ACROSS MINNESOTA TODAY. A SECONDARY
LOW...NOT TERRIBLY STRONG...IS EXPECTED TO DEVELOP OVER THE
FORECAST AREA AS THE SURFACE COLD FRONT MOVES ACROSS THE AREA THIS
AFTERNOON AND EVENING. THIS WILL LIKELY ACT TO INCREASE THE
CONVERGENCE ALONG THE BOUNDARY AND INCREASE OUR PRECIPITATION
POTENTIAL. WE ALSO HAVE A BAND OF STRONG FRONTOGENESIS ALONG AND
BEHIND THE FRONT TO GENERATE PRECIPITATION AS WELL. FOR NOW HAVE A
STEEP GRADIENT OF POPS OVER THE AREA FROM JUST SLIGHT CHANCE POPS
NORTHEAST TO LIKELY OVER THE WESTERN PORTIONS THIS
MORNING...RAMPING UP TO CHANCES WEST AND CATEGORICAL EAST FOR THIS
AFTERNOON. WHILE MUCH OF THE PRECIPITATION WITH THIS SYSTEM WILL
BE STRATIFORM...ESPECIALLY LATER IN THE DAY...THERE WILL AT LEAST
BE SOME EMBEDDED THUNDER THIS AFTERNOON WITH THE STRONGEST LIFT
AND STEEPEST MID LEVEL LAPSE RATES. HIGH TEMPERATURES TODAY TO
ALSO HAVE A STEEP GRADIENT FROM AROUND 60 NORTHWEST TO UPPER 60S
SOUTHEAST.
TONIGHT THE RAIN OVER THE EASTERN PORTIONS OF THE AREA WILL SWEEP
QUICKLY OFF TO THE EAST...LEAVING THE AREA DRY BY THE TIME WE GET TO
MIDNIGHT...OR CLOSE TO IT. THERE MAY BE SOME LINGERING RAIN IN THE
NORTHEAST AFTERWARDS...DEPENDING ON WHICH MODEL YOU USE AND THE
TRACK OF THE SURFACE LOW. TEMPERATURES IN THE LOW 40S WILL SWEEP
INTO THE AREA BEHIND THIS SYSTEM...LIKELY WITH AT LEAST A BRIEF
PERIOD OF AT LEAST THINNER CLOUDS TO AID IN COOLING THE
TEMPERATURES. LE
LONG TERM...THURSDAY THROUGH TUESDAY...
LARGE UPPER LEVEL CLOSED LOW TO PROVIDE CLOUDY...COOL...AND DAMP
WEATHER THU...WHICH IS NOW LOOKING MORE LIKELY TO CONTINUE THROUGH
FRIDAY AS WELL. A PROGRESSIVE UPPER LEVEL PATTERN QUICKLY SWEEPS
THIS SYSTEM EAST OVER THE WEEKEND WITH RETURN FLOW BY SUNDAY LEADING
TO MODERATING TEMPERATURES. THE WARMING TREND CONTINUES INTO
MONDAY...ALONG WITH INCREASING CHANCES FOR RAIN AS MOISTURE
INCREASES IN A SW FLOW AHEAD OF A SLOW MOVING FRONT.
00Z MODELS ARE SOMEWHAT SIMILAR WITH DETAILS OF THE UPPER LOW WITH
THE NOTABLE EXCEPTION BEING THE WRF/NAM...WHICH BECOMES A SLOWER
OUTLIER WITH THE EJECTING SURFACE AND UPPER LOW HANGING FURTHER WEST
ON FRIDAY. WILL KEEP THE FORECAST CLOSE TO THE NON-WRF MODEL
CONSENSUS. STRONG UPPER VORT CENTER AND SURFACE LOW ROTATING AROUND
THE NW AND WESTERN SIDE OF THE UPPER LOW OVER WI WILL DROP SOUTH
INTO THE FORECAST AREA THURSDAY AFTERNOON. WRAP AROUND MOISTURE AND
SUFFICIENT LIFT SHOULD LEAD TO WIDESPREAD LIGHT RAIN OR SHOWERS...
SPREADING FROM NORTHWEST TO SOUTHEAST BY AFTERNOON. WITH INCREASING
CONFIDENCE...POPS HAVE BEEN INCREASED TO LIKELY BY AFTERNOON ACROSS
A LARGER AREA OF THE NORTH. WILL CERTAINLY BE A RAW DAY WITH BRISK
W-NW WINDS AND TEMPERATURES NOT LIKELY CLIMBING OUT OF THE 40S IN
THE NORTH WHERE RAIN ARRIVES EARLIER...WHILE THE FAR SOUTH MAY REACH
THE LOWER 50S. THURSDAY NIGHT POPS HAVE BEEN RAISED TO LIKELY ACROSS
THE BOARD AS THE SURFACE LOW MIGRATES SOUTHEAST ACROSS EASTERN IA
INTO NORTH CENTRAL IL BY MORNING. WHILE MOISTURE WILL BE LIMITED TO
WHAT ROTATES AROUND THE GREAT LAKES UPPER LOW...THE EXTENDED PERIOD
OF LOW LEVEL CONVERGENCE AND MID LEVEL FORCING SHOULD SQUEEZE OUT
RAIN AMOUNTS FROM SEVERAL HUNDREDTHS OF A INCH TO PERHAPS OVER A
QUARTER INCH THU AND THU NIGHT.
FRIDAY...ANOTHER LOBE OF ENERGY ROTATING AROUND THE LOW SHOWN NEAR
CHICAGO WILL KEEP AT LEAST SCATTERED LIGHT RAIN SHOWERS A
POSSIBILITY THROUGH MUCH OF THE DAY. OUTSIDE THE SHOWERS...THE
PROSPECT OF SUNSHINE LOOKS VERY LIMITED IN THE CYCLONIC FLOW AND
LAYER OF MOISTURE SHOWN BELOW 850...WHICH SHOULD LIMIT HIGHS TO THE
LOWER 50S AT BEST.
SATURDAY THROUGH TUESDAY...A PASSING RIDGE AT THE SURFACE AND UPPER
LEVELS SATURDAY INTO SATURDAY NIGHT WILL BE FOLLOWED BY STRONG
RETURN FLOW AND WARM ADVECTION SUNDAY INTO MONDAY. HAVE KEPT HIGHS
TRENDING FROM THE UPPER 50S TO LOWER 60S SATURDAY...RISING TO THE
UPPER 60S TO MID 70S MONDAY WHILE LOWS CLIMB FROM THE 30S FRIDAY
NIGHT TO THE 50S FOLLOWING RISING DEWPOINTS MONDAY MORNING. BASED ON
850 MB TEMPERATURES...HIGHS MONDAY COULD POTENTIALLY BE NEARLY AS
WARM AS YESTERDAY. OVERALL...THE 00Z MODELS HAVE COME INTO BETTER
AGREEMENT WITH THE UPPER LEVEL PATTERN AND SURFACE FRONTAL FEATURES
MONDAY INTO TUESDAY...DEVELOPING WARM ADVECTION AND MOISTURE RETURN
THAT COULD LEAD TO RAIN CHANCES FROM LATE SUNDAY NIGHT THROUGH
TUESDAY. BASED ON THE WARM ADVECTION...RETURN OF GULF MOISTURE...AND
STEEP MID LEVEL LAPSE RATES...THUNDERSTORMS WILL BE POSSIBLE
ESPECIALLY MONDAY INTO MONDAY NIGHT AND HAVE ADDED MENTION.
SHEETS
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1218 PM CDT WED OCT 17 2012
...UPDATED AVIATION DISCUSSION...
.SHORT TERM /TODAY/...
SEVERAL FORECAST CONCERNS TODAY WITH STRONG COLD FRONT EXPECTED TO
SWEEP ACROSS IOWA THIS MORNING. FROPA WILL BE BETWEEN 11-15Z THIS
MORNING FROM WEST TO EAST ACROSS THE FORECAST AREA. LEANED TOWARD A
BLEND OF THE SHORT TERM HIGH-RESOLUTION MODELS HRRR/4.0KM WRF AND
SREF/NAM12 AS THEY SEEMED TO HAVE BEST HANDLE ON TIMING OF FRONT AND
POPS.
SHARP PRESSURE GRADIENT COMBINED WITH A DECENT TROPOPAUSE UNDULATION
LATE THIS MORNING INTO THE AFTERNOON WILL PROVIDE A WINDY DAY. WINDS
ATOP THE MIX LAYER RANGE FROM 30-35KTS WEST OF THE INTERSTATE 35 AND
WITH THE CLOUDS CLEARING OUT THIS AFTERNOON IN WESTERN IOWA...SHOULD
ENHANCE THE WIND GUSTS. TWEAKED WINDS UP SLIGHTLY IN THIS AREA
THROUGH 18Z. STILL BORDER LINE WIND ADVISORY ATTM. KEPT MENTION OF
THE NON-DIURNAL TEMPS WITH THE STRONG CAA DEVELOPING LATE THIS
MORNING. 850MB TEMPS DROP TO +2C TO +4C BY THIS AFTERNOON. A NICE
STRATUS DECK LOOKS TO MOVE IN BY AROUND 00Z THURSDAY AS RH AT 850MB
INCREASES GREATER THAN 80 PERCENT. INCREASED SKY COVER ACROSS THE FAR
NORTHWEST.
BEST POPS WILL BE ACROSS THE SOUTHEAST LATE THIS MORNING WHERE
STRONGEST FORCING AND BEST THETA-E ADVECTION IS LOCATED. IN
ADDITION...SOME ELEVATED INSTABILITY IS PRESENT AND LIKELY WILL THE
HIGHER QPF AMOUNTS. THE LATEST HRRR COINCIDES WITH THIS THINKING AND
TWEAKED UP QPF THROUGH 18Z.
.LONG TERM /TONIGHT THROUGH TUESDAY/...
DEEPENING UPPER LOW WILL BE DIVING INTO MINNESOTA AND IOWA OVERNIGHT
WITH AN IMPRESSIVE 90-100KT JET ROUNDING THE BASE OF THE TROUGH AND
BEING INGESTED INTO THE SYSTEM THROUGH THURSDAY. THERE IS A
SIGNIFICANT AMOUNT OF ENERGY EMBEDDED IN THE FLOW WHICH WILL WRAP
AROUND THE SYSTEM THE NEXT FEW DAYS. ONE OF THE MORE VIGOROUS
IMPULSES IS MOVING THROUGH SRN IA AND MISSOURI TODAY AND WILL WRAP
AROUND THE SYSTEM AND MOVE ACROSS MINNESOTA AND IOWA ON THURSDAY AND
WILL SHIFT THE AXIS OF THE UPPER LOW BACK WEST A BIT. THIS SYSTEM
WILL ALSO HAVE GOOD THETA-E ADVECTION EMBEDDED WHICH WILL HELP PUSH
PWATS BACK TO NEAR 0.75 INCHES AND COMBINED WITH THE KINEMATIC
ENERGY...SHOULD RESULT IN WIDESPREAD SHOWERS BY THURSDAY AFTERNOON
AND EVENING. IN ADDITION...AN INCREASING PRESSURE GRADIENT OVER
WESTERN IOWA AND WINDS APPROACHING 50 KTS IN THE LOWEST 4 KFT OF THE
ATMOSPHERE DOES RAISE CONCERNS ABOUT POTENTIAL WIND ADVISORY
CRITERIA. IT WILL BE CLOSE...WEST OF INTERSTATE 35 THOUGH THERE ARE
A FEW NEGATIVES THAT WILL KEEP THE WINDS FROM REACHING MAX
POTENTIAL. A STRATUS DECK SHOULD ENGULF MUCH OF IOWA ON THURSDAY AND
THIS WILL LIMIT HIGH TEMPERATURES AND POTENTIAL FOR MIXING.
TEMPERATURES WILL LIKELY LINGER IN THE 40S FOR MUCH OF THE DAY. THE
GOOD REGION OF SUBSIDENCE WILL BE WEST OF THE MISSOURI RIVER AND
THAT WILL BE THE REGION FOR GOOD MOMENTUM TRANSFER AND BETTER MIXING
OF WINDS ALOFT.
PRECIPITATION CHANCES WILL CONTINUE THURSDAY NIGHT BEFORE THE BULK
OF THE ENERGY ROUNDS THE BASE OF THE UPPER LOW AND IT BEGINS TO
SHIFT OFF TO THE EAST ON FRIDAY. A FEW SHOWERS MAY LINGER FRIDAY
BEFORE MID LEVEL RIDGING MOVES IN FOR THE WEEKEND WITH WARMER
TEMPERATURES. STRENGTHENING HIGH PRESSURE OVER THE SOUTHEAST CONUS
AND REGION OF LOW PRESSURE TO THE WEST WILL ENHANCE THE WARM
ADVECTION INTO SUNDAY. AS MENTIONED LAST NIGHT...THIS SET UP IS
CONDUCIVE TO A STRONG SURGE OF LOW LEVEL GULF MOISTURE. SOME MINOR
TIMING DETAILS ON WHEN THIS MOISTURE ARRIVES IN IOWA...EITHER LATE
SUNDAY OR SUNDAY NIGHT. THIS MOISTURE WILL LIFT NORTH AND POOL AHEAD
OF A SFC BOUNDARY THAT WILL BE INCHING SOUTHEAST THROUGH IOWA SUNDAY
THROUGH MONDAY. THIS TYPE OF MOISTURE OFTEN RESULTS IN A STRATUS
FIELD AND MAY BE ACCOMPANIED WITH FOG OR DRIZZLE. ENHANCED VERTICAL
TURBULENCE WITH THE SFC BOUNDARY NEAR BY ENHANCES THAT POSSIBILITY.
ANY STRATUS CERTAINLY WOULD IMPACT TEMPERATURES. A SHORT WAVE
LIFTING THROUGH THE SOUTHWEST FLOW WILL INTRODUCE SOME CONVECTIVE
POTENTIAL MONDAY AND MONDAY NIGHT. THE MILD SOUTHWEST FLOW WILL
MAINTAIN THROUGH THE END OF THE EXTENDED WITH HIGHS IN THE 60S AND
70S.
&&
.AVIATION...17/18Z
PRECIPITATION BEHIND COLD FRONT WILL CONTINUE TO PUSH
EASTWARD...AFFECTING KDSM/KOTM/KMCW/KALO THROUGH 00Z. THERE WILL BE
LOCALIZED MVFR CEILINGS...BUT DO NOT ANTICIPATE THEM TO AFFECT
SITES...AND IF SO ONLY BRIEFLY. BEHIND FRONT...WINDS WILL BE STRONG
AND GUSTY FROM THE WEST TO NORTHWEST. WINDS WILL REMAIN STRONG
THROUGH THE NIGHT....AND WILL INCREASE AFTER 12Z...WITH GUSTS AGAIN
RETURNING. IN ADDITION...ANOTHER ROUND OF PRECIPITATION WILL BEGIN
TO AFFECT THE WESTERN SITES...KFOD/KDSM LATE IN THE PERIOD WITH MVFR
CEILINGS AND -RA POSSIBLE NEAR 15Z. HOWEVER...DO NOT HAVE ENOUGH
CONFIDENCE TO INCLUDE MENTION ATTM.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...DONAVON
AVIATION...AWB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
433 PM EDT WED OCT 17 2012
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 432 PM EDT WED OCT 17 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF IN THE PROCESS OF
AMPLIFYING OVER THE PLAINS. THERE ARE A NUMBER OF EMBEDDED SHORTWAVES
IN THE DEEPENING TROF...BUT THE 130-140KT JET PER LATEST RUC
CURRENTLY DROPPING DOWN THE BACKSIDE OF THE TROF WILL BE THE FACTOR
LEADING TO THE TROF CONTINUING TO DEEPEN. IN FACT...TROF WILL BECOME
DEEP FOR THIS TIME OF YEAR. AT PEAK INTENSITY THU OVER THE
MID/UPPER MISSISSIPPI VALLEY...500MB HEIGHTS WILL BE 3.5 STANDARD
DEVIATIONS BLO THE LONG TERM AVG FOR MID OCT. AT THE SFC...LOW PRES
OF 29.1 INCHES IS OVER NW MN WITH COLD FRONT EXTENDING INTO FAR WRN
WI/FAR ERN IA AND MO. SO FAR...PCPN COVERAGE HAS BEEN GREATEST NEAR
THE SFC LOW OVER NW MN/ERN ND. HOWEVER...SHRA ARE INCREASING IN
COVERAGE SOUTHWARD ALONG/AHEAD OF COLD FRONT AS UPPER DIFFLUENCE
IMPROVES DUE TO AFOREMENTIONED UPPER JET DROPPING DOWN BACKSIDE OF
THE TROF.
AS TROF CONTINUES TO DEEPEN TONIGHT...A NEW LOW PRES CENTER IS
EXPECTED TO DEVELOP ON COLD FRONT IN ERN WI AND THEN LIFT NW TO THE
VCNTY OF WRN LAKE SUPERIOR THU MORNING. DEEPENING SYSTEM WILL LEAD
TO LOW-LEVEL JET RAMPING UP TO AROUND 50KT WHICH WILL TRANSPORT
ABUNDANT MOISTURE N INTO THE AREA (PRECIPITABLE WATER INCREASES TO
200PCT OF NORMAL OR BETTER). STRONG DIRECTIONAL DIFFLUENCE AT UPPER
LEVELS OVERTOP TIGHTENING LOW LEVEL FRONTAL BOUNDARY WILL SUPPORT AN
EXPANDING AREA OF SHRA SPREADING INTO THE FCST AREA TONIGHT. LIKELY
TO CATEGORICAL POPS LOOK ON TRACK. MODELS HAVE AND CONTINUE TO POINT
TOWARD SW/W UPPER MI RECEIVING THE HEAVIEST RAINFALL WITH THAT AREA
NEAR THE TRACK OF NW MOVING SFC WAVE. SO...AS IN PREVIOUS FCSTS...
HIGHEST POPS WERE PAINTED IN THAT AREA. NOT OUT OF THE QUESTION THAT
THERE MAY BE A FEW RUMBLES OF THUNDER GIVEN SHOWALTER INDEX FALLING
TOWARD ZERO. MIN TEMPS WILL BE WELL ABOVE NORMAL GIVEN CLOUDS/DEEP
MOISTURE. MINS SHOULD RANGE FROM THE MID 40S FAR W WHERE CAA WILL
GET UNDERWAY OVERNIGHT TO THE MID 50S EAST.
MAIN PUSH OF PCPN FROM TONIGHT WILL ROTATE NW OF THE AREA BY
MORNING. SO THERE MAY BE SOMEWHAT OF A BREAK IN PCPN FOR A WHILE THU
MORNING. HOWEVER...A SHORTWAVE ROTATING AROUND MIDLEVEL LOW WILL BE
SWINGING N TOWARD ERN UPPER MI...AND SHOULD BRING ANOTHER ROUND OF
GREATER SHRA COVERAGE INTO ESPECIALLY THE CNTRL AND ERN FCST AREA
FOR THE AFTN. TEMP RISE THU WILL BE LIMITED BY CLOUDS/CAA.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 432 PM EDT WED OCT 17 2012
AN UPPER LOW WILL BE SPINNING OVER FAR SW WI AT 00Z FRI...WITH A SFC
LOW TO THE N OF IT BUT S OF WRN LAKE SUPERIOR. A SHORTWAVE TROUGH
WILL BE JUST SE OF THE CWA AT 00Z FRI...MOVING E TO W TO NEAR THE
CENTER OF THE CWA BY 06Z FRI...THEN TO FAR WRN UPPER MI/FAR WRN LAKE
SUPERIOR BY 12Z FRI. MODELS ARE IN GOOD AGREEMENT WITH THE
SHORTWAVE...WITH ONLY MINOR TIMING DIFFERENCES BETWEEN THEM /THE GFS
WAS USED WITH THE HIGHEST WEIGHT SINCE THE TIMING WAS BETWEEN THE
FASTER NAM AND SLOWER ECMWF/. THE BEST CHANCES FOR WIDESPREAD PRECIP
WILL BE FROM 00Z-06Z FRI. AFTER 06Z FRI...THE SFC LOW MOVING THROUGH
WITH THE SHORTWAVE WILL QUICKLY MOVE TO SW WI. ALSO...BETWEEN
00Z-12Z FRI...THE MID/UPPER LOWS WILL BE STACKED JUST W OF LAKE
MICHIGAN...WITH LOW LEVEL CYCLONIC FLOW UP THE LONG AXIS OF LAKE
MICHIGAN. 850MB TEMPS WILL BE BETWEEN 0C AND -1C...SO LAKE ENHANCED
RAIN WILL BE POSSIBLE INTO SCENTRAL AND ERN UPPER MI LATE THU NIGHT
INTO FRI MORNING.
SFC FEATURES BEGIN TO BREAK DOWN QUICKLY ON FRI AS THE SYSTEM MOVES
TO SE LOWER MI BY LATE IN THE DAY. THE ECMWF IS ABOUT 12 HOURS
SLOWER IN MOVING THE SYSTEM INTO QUEBEC ON SAT. EVEN SO...MODELS
AGREE WITH SHOWING A SFC RIDGE MOVING INTO THE CWA AROUND 18Z
SAT...WITH AN UPPER RIDGE PUSHING IN FROM THE NW. THE RIDGE WILL
LEAD TO PRETTY QUIET WEATHER OVER THE WEEKEND...WITH ANY SIGNIFICANT
CHANCES FOR RAIN BEING OVER THE FAR E AS THE LOW MOVES E OF THE CWA
SAT...BUT THOSE CHANCES ARE SMALL. SINCE WARM AIR WILL NOT START TO
RETURN TO THE AREA UNTIL THE SFC RIDGE MOVES THROUGH...SAT WILL SEE
SIMILAR TEMPS TO FRI WITH HIGHS IN THE MID 40S TO MID 50S. SUN WILL
BE WARMER AS 850MB TEMPS INCREASE TO 8-10C...LEADING TO HIGHS IN THE
50S AND 60S.
AFTER SUN...SUBSTANTIAL MODEL DISAGREEMENT ON THE LOCATION OF A SFC
RIDGE THAT MAY MOVE IN THE REGION. THE PROBLEM COMES FROM A SFC
TROUGH/STATIONARY FRONT THAT WILL BE S OF THE RIDGE. THE GFS KEEPS
THE RIDGE OVER THE CWA THROUGH NEXT WED...KEEPING US DRY...BUT THE
ECMWF HAS THE TROUGH/FRONT OVER THE CWA THROUGH MUCH OF THE
PERIOD...WHICH WOULD RESULT IN A MOST WET FORECAST. WITH HIGH MODEL
DISAGREEMENT AND LOW RUN TO RUN CONTINUITY...USED A CONSENSUS OF
MODELS IN THIS PORTION OF THE FORECAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 140 PM EDT WED OCT 17 2012
LOW PRESSURE SYSTEM OVER NW MN WILL SETTLE INTO THE WESTERN GREAT
LAKES REGION TONIGHT AND THU. AHEAD OF SYSTEM...EXPECT VFR
CONDITIONS THRU THE AFTN AT KIWD/KCMX/KSAW. AS SHRA DEVELOP/SPREAD
INTO THE AREA TONIGHT...EXPECT CONDITIONS TO FALL TO IFR/LIFR AS
ABUNDANT MOISTURE SWINGS N. CONDITIONS SHOULD BE LOWEST AT KSAW
UNDER FAVORABLE UPSLOPING WIND. MAIN PCPN AREA SHOULD LIFT OUT BY
SUNRISE WITH CONDITIONS RISING TO HIGH IFR/LOW MVFR DURING THE
MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 432 PM EDT WED OCT 17 2012
A TRICKY FCST SHAPING UP TONIGHT INTO THU. DEEP SFC LOW NOW IN NW MN
WILL BE REPLACED BY A NEW LOW PRES WAVE THAT WILL DEVELOP IN ERN WI
TONIGHT AND THEN ROTATE NW TO VCNTY OF WRN LAKE SUPERIOR THU. IN
RESPONSE TO THE NEW LOW...A BRIEF PERIOD OF E TO SE GALES MAY
DEVELOP LATE TONIGHT INTO THU MORNING OVER CNTRL AND ERN LAKE
SUPERIOR. GIVEN UNCERTAINTY IN HOW QUICK OR DEEP THE NEW LOW WILL
BECOME BY THU MORNING...HELD OFF ON THE ISSUANCE OF A GALE WARNING
FOR NOW. AS A TROUGH MOVES THROUGH THURSDAY NIGHT...SOUTHEAST WINDS OVER
EASTERN LAKE SUPERIOR AND NORTHEAST WINDS OVER WESTERN LAKE SUPERIOR
WILL GUST TO AROUND 25KTS. WINDS WILL THEN DIMINISH TO BELOW 20KTS
FRIDAY THROUGH MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...ROLFSON/TITUS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1221 PM CDT WED OCT 17 2012
.DISCUSSION...
UPDATE TO REMOVE BURLEIGH AND EMMONS COUNTIES FROM THE RED FLAG
WARNING AS THE LATEST HRRR AND RAP RUNS DEPICT PRECIPITATION
LASTING THROUGH MUCH OF THE AFTERNOON. ALSO GETTING FROM REPORTS
OF SLEET IN THE MINOT AREA. THE 12 UTC GUIDANCE CONSENSUS IS
APPARENTLY NOT PICKING UP ON AN ELEVATED MELTING LAYER...AND WILL
ADD A MENTION OF SLEET TO THE TERMINAL MORAINE WHERE A RELATIVE
MINIMUM IN 850 MB TEMPERATURE EXIST.
&&
.AVIATION...
CIGS HAD IMPROVED TO VFR AT KISN/KDIK...AND EXPECT VFR CIGS TO
PERSIST AT KISN BUT RETURN TO MVFR LATER TONIGHT. CIGS TO BECOME
SCATTERED AT KDIK THIS AFTERNOON. FARTHER EAST AT
KMOT/KBIS/KJMS...EXPECT PERIODS OF MVFR CIGS AND SHOWERS LINGERING
INTO THE AFTERNOON. CIGS AT KBIS MAY BECOME VFR FOR A TIME IN THE
AFTERNOON...THEN GO BACK TO MVFR AFT 00Z. WINDS WILL CONTINUE TO
INCREASE THROUGH THE AFTERNOON...LIKELY REACHING GUSTS AROUND 45-55
KTS. WINDS WILL DIMINISH SLIGHTLY LATER TONIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 7 PM CDT /6 PM MDT/ THURSDAY FOR
NDZ001>005-009>013-017>023-025-031>037-040>048-050-051.
RED FLAG WARNING UNTIL 10 PM CDT /9 PM MDT/ THIS EVENING FOR
NDZ009-017>020-031>034-040>045.
&&
$$
SHORT TERM...AYD
AVIATION...JV
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
216 PM EDT WED OCT 17 2012
.SYNOPSIS...
HIGH PRESSURE SLIPS EAST WEDNESDAY. COLD FRONT BRINGS GOOD CHANCE
FOR SHOWERS THURSDAY INTO FRIDAY. THE PARENT DEEP LOW PRESSURE
SYSTEM APPROACHES FROM THE NORTHWEST FRIDAY NIGHT INTO SATURDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
SLOW BUT STEADY PRESSURE FALLS TO OCCUR WITH THE APPROACH OF THE
COLD FRONT FROM THE WEST...CURRENTLY SITUATED JUST TO THE WEST OF
THE UPPER REACHES OF THE MISSISSIPPI. FRONTAL SYSTEM WILL BE IN
THE PROCESS OF OCCLUDING OVER THE WESTERN GREAT LAKES. THIS
STACKED LOW PRESSURE SYSTEM WILL BEGIN TO FILL AT THE SURFACE AND
ALOFT WHILE THE FRONT BARRELS THROUGH THE OHIO VALLEY AND
ULTIMATELY THROUGH THE MOUNTAINS.
RELIED HEAVILY...BUT NOT COMPLETELY...ON STRAIGHT NAM VALUES FOR
WIND VELOCITIES DURING THE NEAR TERM...USUALLY BETTER
REPRESENTATIVE OF A STRONGER WIND SCENARIO. COULD SEE SPORADIC
30KT GUSTS. LOW LEVEL JET AHEAD OF THE FRONT WILL PEAK OUT NEAR
60KTS.
THIS WILL BE A LOW INSTABILITY/HIGHLY DYNAMIC SYSTEM...WHICH WILL
LEAD TO SOME THUNDER POTENTIAL IN THE AFTERNOON HOURS. STRONG FLOW
THROUGH THE LAYERS WILL BRING SOME ORGANIZATION TO SHOWERS/STORMS
THAT COULD FORM...SO ISOLATED WIND PROBLEMS ARE POSSIBLE. ONE
THING TO WATCH WILL BE THE POSITIONING OF THE COLD FRONT AS IT
PUSHES INTO THE MOUNTAINS. NORTHERN PORTIONS OF THE CWA MAY END UP
BEING CUT OFF FROM THE BETTER AVAILABLE MOISTURE IN SOUTHERLY
FLOW...WHICH MAY RELEGATE ANY THUNDER TO THE SOUTHERN ZONES.
REGARDLESS...DESPITE THE SPC OUTLOOK...WILL GO MODEST ON THE
THUNDER POTENTIAL IN THE GRIDS FOR NOW...AND WILL CAP IT AT LOW
CHANCE. WILL LET THE MID SHIFT REEVALUATE THIS.
SHORT LIVED DRY SLOT WITH MAINLY CLEAR SKIES SHOULD FOLLOW THE
FRONT. MORE LOW LEVEL MOISTURE RETURNS TO THE FRINGES OF THE
WESTERN ZONES JUST PRIOR TO 00Z FRIDAY.
FRONTAL PASSAGE/RAIN WILL KNOCK TEMPERATURES OFF A FEW DEGREES
TOMORROW FROM THE WARMER VALUES CURRENTLY OCCURRING.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
THE NAM/CMC/GFS/ECMWF ARE IN AGREEMENT WITH THE TIMING OF
CONVECTION ASSOCIATED WITH APPROACHING COLD FRONT OVER SOUTHEAST
OH BY 12Z THURSDAY. HOWEVER...THERE ARE INTENSITY DIFFERENCES IN
QPF FIELDS...AS WELL AS IN THE UPPER LEVEL SUPPORT. THE GFS HAS
STRONGER MID LEVEL FORCING ACROSS THE OH RIVER...WHILE THE NAM
WEAKENS ITS FORCING. NEVERTHELESS...BELIEVE IN PREVIOUS FORECAST
BRINGING HIGH CATEGORICAL POPS INTO SOUTHEAST OH BY 12Z...DECREASING
TO LIKELY AS THE FRONT SWEEPS EAST INTO THE AFTERNOON HOURS. H850
WINDS AHEAD OF THE FRONT ARE BETWEEN 55-60 KNOTS IN THE WARM
SECTOR. DEWPOINTS WILL INCREASE INTO THE LOWER 50S UNDER DEEP
SOUTH SOUTHWEST FLOW...DESPITE OF AFTERNOON MIXING.
HOWEVER...PWATS LOOKS RATHER LOW BARELY OVER ONE INCH.
VERY WEAK LAYERED CAPE...BUT DEEP LAYERED SHEAR EXCEEDING 55
KNOTS...STORM RELATIVE HELICITY EXCEEDING 300 M2/S2...AND BOUNDARY
LAYER CONVERGENCE ALONG THE FRONT CALLS FOR A DYNAMIC ENVIRONMENT
CAPABLE TO PRODUCE STORMS. KEPT STORM MENTION WITH LIKELY POPS
DECREASING IN COVERAGE AS THE FRONT MOVE EAST THURSDAY AFTERNOON.
SEVERE STORMS ARE NOT ANTICIPATED AT THIS TIME...STRONG GUSTY FLOW
ARE WORTH TO BE MENTIONED IN THE HWO.
STRONG GUSTY WINDS CAN MIX DOWN TO SFC ALONG FRONTAL
CONVECTION...AND CAN BE POSSIBLE ALSO OVER THE HIGHER ELEVATIONS.
KEPT SFC FRONT EXITING EASTERN MOUNTAINS BY 21Z..IF NOT A LITTLE
SOONER. EXPECT DRY SLOT TO PRODUCE SOME BREAKS IN THE CLOUDS
MAINLY SOUTH AND CENTRAL SECTIONS OF OUR CWA.
THIS COLD FRONT...EXTENDS NORTHWEST AS A OCCLUDED FRONT INTO THE
PARENT DEEP LOW PRESSURE SYSTEM OVER THE GREAT LAKES. SOME
DIFFERENCES NOTED IN THE H5 LOW CENTER...WITH THE NAM SHOWING IT
OVER THE OH VALLEY...THE GFS OVER THE GREAT LAKES...AS WELL AS THE
ECMWF AND CMC. THEREFORE...PER CONSENSUS...EXPECT LOW PRESSURE
TO APPROACH OUR AREA FROM THE NORTHWEST...BUT LIFT NORTHEAST
FRIDAY NIGHT. RAP AROUND MOISTURE BEHIND THE DEPARTURE LOW WILL
BRING CHANCES OF STRATIFORM RAIN ACROSS THE NORTHERN PORTIONS OF
THE AREA FRIDAY...INTO EARLY SATURDAY MORNING...PER GFS/ECMWF/CMC
CONSENSUS.
KEPT WIND GUSTS 20-30 KNOTS DO TO CAA AND EFFICIENT MOMENTUM
TRANSFER AS SEEN IN INVERTED V FEATURE IN BUFKIT SOUNDING FRIDAY.
WENT A DEGREE OR TWO LOWER THAN MAV/MET GUIDANCE PER UNCERTAINTY
OF CLOUD COVER...GENERALLY UPPER 60S LOWLANDS...RANGING INTO THE
MID 50S HIGHEST ELEVATIONS...FOR THURSDAY. EXPECT A COOLER TREND
THURSDAY NIGHT AND FRIDAY UNDER CAA...AND CLOUD COVER.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
STILL SOME ISSUES WITH MODEL AGREEMENT IN THE LONG TERM PERIOD IN
TERMS OF TIMING AND PATH OF EXITING LOW PRESSURE. GFS IS STILL
FASTER AND FARTHER TO THE NORTH WITH THE UPPER LOW THAN THE ECMWF.
BUT REGARDLESS...A GRADUAL DRYING TREND IS EXPECTED TO BEGIN ON
SATURDAY AS THE UPPER LOW GRADUALLY PUSHES EAST...AND A RIDGE OF
HIGH PRESSURE GRADUALLY STARTS TO BUILD IN FOR THE BEGINNING OF NEXT
WEEK. DID START TO BUMP TEMPERATURES UP A BIT FROM PREVIOUS
FORECAST...AND DRY OUT FORECAST FOR LATE THIS WEEK/EARLY NEXT WEEK.
SOME ISSUES CONCERNING THE TIMING OF NEXT SYSTEM...PROGGED TO ENTER
CWA BY MID WEEK...BUT FOR NOW...MAINTAINED A DRY FORECAST INTO
PERIOD DUE TO UNCERTAINTY.
&&
.AVIATION /17Z WEDNESDAY THROUGH SUNDAY/...
INCREASING CLOUD COVER INTO TONIGHT WILL REMAIN VFR UNTIL
SHOWERS/FRONTAL BOUNDARY ARRIVE. MVFR CEILINGS/VISIBILITIES
PREVAIL WITH THE SHOWERS THURSDAY...ALTHOUGH SOME BOUNCING DURING
THIS TIME IS POSSIBLE. MAY SEE CB TOWARDS 18Z...ESPECIALLY SOUTH
AT BKW.
WIND GUSTS COULD BE MORE PROBLEMATIC...WITH GUSTS 20 TO 30 KNOTS
AHEAD OF THE FRONT POSSIBLE...GENERALLY OUT OF THE SOUTH. NAM
SUGGESTS LLWS POSSIBLE AT CRW AND BKW TONIGHT THROUGH EARLY
THURSDAY. WINDS EASE OFF SOMEWHAT AFTER FRONTAL PASSAGE...AND WILL
KEEP THE GUSTS 20KTS OR BELOW WITH LITTLE DIRECTION CHANGE FOR THE
WESTERN TERMINALS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z THURSDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: MAY NEED SLIGHTLY LONGER MVFR CEILINGS WITH
FRONTAL PASSAGE THURSDAY. MAY NEED CB AT CRW AND CKB THURSDAY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z THURSDAY...
NO WIDESPREAD IFR EXPECTED AT THIS TIME.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...50/26
NEAR TERM...26
SHORT TERM...ARJ
LONG TERM...SL
AVIATION...26
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
601 PM CDT WED OCT 17 2012
.DISCUSSION... /ISSUED 234 PM CDT WED OCT 17 2012/
CURRENT CONDITIONS ARE FOR NOW QUITE TRANQUIL ACROSS THE MIDSOUTH
WITH DEWPOINTS SLOWLY RISING ON STRONG SOUTHERLY BREEZES.
TEMPERATURES WERE IN THE 70S WITH SUNNY TO MOSTLY SUNNY SKIES.
LATEST COLD FRONT LOCATION WAS ELONGATED FROM SOUTHWEST MISSOURI
TO JUST EAST OF DALLAS TEXAS WITH CONVECTION INITIATION JUST WEST
OF SPRINGFIELD. LATEST 18Z LZK SOUNDING SHOWING A STOUT CAP OF 5C
AT 810MB...JUST ABOVE THE STRATUS DECK. CHANCES ARE THAT IT WILL
BE LATER THIS AFTERNOON FOR CONVECTION INITIATION. WILL BE
INTERESTING TO ALSO SEE AND COMPARE THIS SOUNDING TO A 19Z
RESEARCH SOUNDING LAUNCH IN EASTERN ARKANSAS WHERE SKIES WERE
MOSTLY SUNNY.
FOR TONIGHT...SEVERE WEATHER IS STILL LIKELY AS BOTH A STRONG
SHORTWAVE OVER THE CENTRAL PLAINS AND ASSOCIATED COLD FRONT SWING
THROUGH THE MISSISSIPPI VALLEY. 12Z MODEL RUNS ARE IN VERY GOOD
AGREEMENT THAT THE BRUNT OF PRECIPITATION AND SEVERE WEATHER WILL
OCCUR BETWEEN 23-06Z...WITH A HALF TO PERHAPS ONE HALF INCHES OF
TOTAL RAINFALL. AFTER SCANNING SPC`S HHR MODEL... CONVECTION WILL
REMAIN ALONG THE COLD FRONT IN NORTHWEST ARKANSAS AND SOUTHERN
MISSOURI THROUGH THE AFTERNOON HOURS...WITH A PREFRONTAL TROUGH
DEVELOPING AND SPARKING OFF CONVECTION ALONG CROWLEY`S RIDGE BY 6PM.
WIDSPREAD STRATUS CLOUD COVER OVER WESTERN AND CENTRAL ARKANSAS MAY
BE THE REASON FOR THE GREATER FOCUS TO SHIFT TO THE PRE-FRONTAL
TROUGH. BOTH BOUNDARIES ARE EXPECTED TO COMPLETELY MERGE ALONG THE
TENNESSEE RIVER BY MIDNIGHT. STRAIGHT-LINE WINDS WITH STORMS REMAINS
THE GREATEST SEVERE THREAT AS STORM/LINE SPEEDS ARE EXPECTED TO
EXCEED 50 MPH. MOST LOCATIONS WILL SEE DEWPOINTS CLIMB INTO THE
UPPER 50S AND LOW 60S AHEAD OF THE FRONT...WITH MID AND UPPER 60S
MAKING THERE WAY INTO THE SOUTHWEST DELTA COUNTIES. STILL FEEL THAT
THIS LOCATION...THAT IS SOUTH OF I-40 AND WEST OF I-55...WILL HAVE
THE BEST CHANCE FOR A TORNADIC STORM BEFORE 02Z...AND TO A LESSER
DEGREE FURTHER NORTH AND EAST. BY 02Z STORMS WILL HAVE CROSSED INTO
WEST TENNESSEE AND INTO NORTH CENTRAL MISSISSIPPI...QUICKLY EVOLVING
INTO ONE LONG LINE OF INDIVIDUAL BOWING SEGMENTS. THIS BOUNDARY
MERGER/TRANSITION IS IN RESPONSE TO A 80KT 500MB JET CROSSING
ARKANSAS. THUS A BETTER CHANCE FOR WIND DAMAGE WILL EXIST DURING THE
MID TO LATE EVENING HOURS. MODELS INDICATE THAT CONVECTION WILL EXIT
THE MIDSOUTH BY 1AM WITH SURFACE WINDS VEERING MORE WEST
SOUTHWESTERLY. LOWS WILL FALL INTO THE UPPER 40S OVER THE NORTHWEST
COUNTIES WHERE CLEARER SKIES WILL EXIST BEFORE SUNRISE...50S WILL BE
SEEN ELSEWHERE.
THURSDAY THROUGH SATURDAY...A STRONG WEST TO NORTHWEST UPPER FLOW
WILL DOMINATE THE REGION AS A CLOSED UPPER LOW PIVOTS THROUGH THE
SOUTHERN GREAT LAKES. CLOSER TO THE SURFACE HIGH PRESSURE WILL
BUILD EASTWARD FROM THE PLAIN STATES. WEST SOUTHWESTERLY SURFACE
WINDS WILL BECOME GUSTY AGAIN TOMORROW...SO THE NEED FOR ANOTHER
WIND ADVISORY WILL NEED TO BE ACCESSED BY THE NIGHTCREW. WEAK CAA
WILL CONTINUE ON FRIDAY AND SATURDAY AS WINDS SHIFT MORE
NORTHWESTERLY. NONE-THE-LESS THE BEGINNING OF THE WEEKEND WILL BE
NICE.
SUNDAY AND MONDAY...A QUICK WARMING TREND IS ANTICIPATED AS THE
LOW LEVEL FLOW TURNS SOUTHERLY AND AN UPPER RIDGE BUILDS OVER THE
EASTERN HALF OF THE U.S. THE GFS AND EURO SHOW THE PRESENCE OF A
WEAK SHORTWAVE CLIPPING THE REGION SUNDAY NIGHT AND ON MONDAY AS
IT APPROACHES THE RIDGE AXIS. HAVE ADJUSTED A SLIGHT CHANCE FOR
RAIN UP 12 HOURS TO REFLECT THIS NEW TIMING BEGINNING SUNDAY
NIGHT. HIGHS WILL RANGE FROM FIVE TO TEN DEGREES ABOVE NORMAL.
EXTENDED PERIOD...MOSTLY DRY WEATHER AND ABOVE NORMAL
TEMPERATURES WILL PERSIST INTO THE MIDDLE OF NEXT WEEK WITH
SOUTHERLY WINDS KEEPING A FRONT STATIONARY ACROSS THE MID
MISSISSIPPI VALLEY.
JAB
&&
.AVIATION...
00Z TAF SET
NOT MUCH CHANGE FROM PREVIOUS TAF SET. SHRAS/TSRAS BEGINNING TO
DEVELOP OVER EASTERN ARKANSAS WHICH IS WHAT LATEST HRRR MODEL WAS
SHOWING. BEST TIMING FOR KMEM WILL BE BETWEEN 01-04Z...FOR KJBR
00-03Z...FOR KMKL 02-05Z...AND FOR KTUP 03-06Z. LOW CIGS AND VSBYS
WILL OCCUR WITH THE SHRAS/TSRAS. WINDS WILL SWITCH AROUND TO THE
NW BRIEFLY BEHIND THE LINE BEFORE GOING BACK TO THE WSW. SPEEDS
WILL INCREASE TO 15-20 KTS SUSTAINED BETWEEN 15-18Z. GUSTS WILL BE
BETWEEN 25-30 KTS.
KRM
&&
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 53 72 49 69 / 90 10 10 10
MKL 50 71 45 65 / 90 10 10 10
JBR 48 71 47 66 / 70 10 10 10
TUP 55 73 45 70 / 90 10 10 10
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...WIND ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI-
PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...WIND ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR DUNKLIN-PEMISCOT.
MS...WIND ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR BENTON MS-COAHOMA-
DESOTO-LAFAYETTE-MARSHALL-PANOLA-QUITMAN-TALLAHATCHIE-TATE-
TUNICA-YALOBUSHA.
TN...WIND ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR CARROLL-CHESTER-
CROCKETT-DYER-FAYETTE-GIBSON-HARDEMAN-HAYWOOD-HENDERSON-
HENRY-LAKE-LAUDERDALE-MADISON-OBION-SHELBY-TIPTON-WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1246 PM CDT WED OCT 17 2012
.DISCUSSION...
18Z TAF UPDATE DISCUSSION BELOW.
&&
.AVIATION...
AREAWIDE SKIES CLEARING OUT TO VFR AHEAD OF TONIGHT`S FRONTAL
PASSAGE. FROPA IS TIMED TO PASS ACROSS THE NORTHERN HUBS BETWEEN
18/00-03Z...CENTRAL TERMINALS BETWEEN 18/03-06Z...AND SLOWING TO
THE COAST WITH WINDS GOING VRB IN THE 18/08-12Z TIME FRAME.
OVERALL...A DRY FRONTAL PASSAGE WITH THE BULK OF THE ENERGY AND
HIGHEST MOISTURE DISPLACED EAST OF THE MAJORITY OF HUBS. EARLY
MORNING VCSH IS NOT TOTALLY OUT OF THE QUESTION...BUT CURRENT
CONFIDENCE IS TOO LOW TO PLACE WITHIN THIS PACKAGE. CONFIDENCE IS
HIGHER THAT TERMINALS CLOSER TO THE COAST WILL EXPERIENCE EARLY
THURSDAY MORNING MVFR...POSSIBLY TEMPO IFR...CEILINGS AS THE
BOUNDARY HANGS UP JUST SHY OF THE SHORELINE. BRISK SOUTH-SOUTHWEST
WINDS TODAY WILL WEAKEN AND VEER PAST SUNSET...BECOMING MORE MODERATE
NORTH-NORTHEAST POST-15Z THURSDAY UNDER PARTIALLY CLEARING SKIES.
31
&&
.PREV DISCUSSION... /ISSUED 1055 AM CDT WED OCT 17 2012/
UPDATE...
SEE MORNING UPDATE.
DISCUSSION...
JUST A FEW CHANGES THIS MORNING AS HIGHER PW AIR LINGERS ALONG THE
COAST. RADAR IS SHOWING A FEW SHRA ALONG AND EAST OF HWY 59 SO
WILL ADD ISOLATED SHRA TODAY. WATER VAPOR IMAGERY SHOWS SOME DRIER
AIR WORKING EAST SO FEEL THE THREAT FOR SHRA WILL BE SHORT LIVED
AND PROBABLY END BY EARLY AFTERNOON. THAT SAID...THE LATEST RAP13
SHOWS SHRA CONTINUING ALL DAY OVER PARTS OF THE CENTRAL AND
EASTERN ZONES. WILL WATCH TRENDS AND HIGHER POPS MIGHT BE NEEDED
THIS AFTN IF THE RAP VERIFIES. WILL ALSO LOWER MAX TEMPS DUE TO A
COOL START...LINGERING CLOUD COVER AND MIXING FROM STRONGER WINDS.
NEW ZONES OUT BY 11 AM. 43
PREV DISCUSSION... /ISSUED 446 AM CDT WED OCT 17 2012/
DISCUSSION...
SHOULD MARKEDLY WARMER/DRIER ACROSS SE TX TODAY WITH THE PASSAGE
OF THAT STRONG SHORTWAVE LAST NIGHT. CLEARING SKIES/RETURN OF ON-
SHORE WINDS WILL HELP HI TEMPS TO TOP OFF INTO THE UPPER 80S AND
LOWER 90S THIS AFTN. HOWEVER RAIN CHCS STILL SET TO RETURN LATER
TONIGHT WITH THE PASSAGE OF THE COLD FRONT. FAVOURABLE UPPER JET
DYNAMICS ALONG WITH LIFT ALONG THE FRONT ITSELF SHOULD BE ENOUGH
FOR ISO/WIDELY SCT RAINS WITH FROPA. CURRENTLY THINKING THAT THE
HIGHER CHCS WILL BE OVER THE NERN CWA (WHERE LIFT IS STRONGEST).
FRONT SHOULD BE INTO THE NEARSHORE WATERS BY THURS MORNING AS WE
COOL OFF/DRY OUT ONCE AGAIN. A SLOW WARM UP THEN PROGGED THROUGH
THE END OF THE WEEK AS THE ASSOCIATED HIGH EVENTUALLY SETTLES IN
THE SERN U.S. THIS SHOULD ALLOW FOR THE RETURN OF ONSHORE WINDS/
LOW LEVEL MOISTURE OVER THE WEEKEND.
FAIRLY DECENT AGREEMENT WITH MODELS THROUGH THE START OF NEXT WK
AS A SOMEWHAT FLATTISH UPPER RIDGE DOMINATES THE PATTERN. BUT WE
ARE SEEING QUITE A BIT OF DISAGREEMENT FOR THE VERY LATTER STAGE
OF THE FCST CYCLE. ECMWF APPEARS TO BE MUCH MORE AGGRESSIVE/FAST
WITH THE APPROACH/DEVELOPMENT OF THE NEXT LONGWAVE TROF WHEN COM-
PARED TO THE GFS. SO WILL LIKELY KEEP WITH CURRENT EXTENDED FCST
FOR NOW AND SEE WHAT SHAKES OUT FOR LATER. 41
MARINE...
INCREASING SOUTHERLY FLOW TODAY WITH WINDS IN THE NEARSHORE
AREAS INCREASING TO 15 TO 20 KNOTS BEFORE RELAXING LATE THIS
AFTERNOON AND EVENING PRIOR TO THE ARRIVAL OF THE FRONT
THURSDAY MORNING. HAVE HOISTED A SCEC FOR THE NEARSHORE WATERS. WILL
HAVE TO KEEP AN EYE OUT FOR STRONG STORMS ALONG THE FRONTAL BOUNDARY
PASSAGE IN AND AROUND GALVESTON BAY AND HIGH ISLAND AREA WHERE MORE
FAVORABLE CAPE/SHEAR PROFILES SHOULD PREVAIL. AFTER THE FRONTAL
PASSAGE EXPECTING WINDS TO CLIMB TO 15 TO 20 KNOTS AND WILL LIKELY
NEED SCECS. WINDS GRADUALLY SWING TO THE SOUTHEAST AND EAST AS RIDGE
SLIDES EAST AND PARKS KEEPING A FAIRLY TIGHT GRADIENT OVER THE AREA
THIS WEEKEND.
45
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 58 80 52 82 56 / 10 10 10 10 10
HOUSTON (IAH) 65 82 54 83 56 / 20 20 10 10 10
GALVESTON (GLS) 73 81 66 80 67 / 20 20 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 7 PM CDT THIS EVENING
FOR THE FOLLOWING ZONES: 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...31
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
324 PM CDT WED OCT 17 2012
.SHORT TERM...
.TONIGHT...FORECAST CONFIDENCE HIGH.
A SHORTWAVE MOVING ACROSS SOUTHERN AND CENTRAL WI IS CAUSING AN AREA
OF SHOWERS...POSSIBLY WITH A FEW EMBEDDED THUNDERSTORMS... TO MOVE
NORTHEAST ACROSS SOUTH CENTRAL WI THIS AFTERNOON. ANOTHER AREA OF
SHOWERS WERE MOVING INTO SOUTHWEST WI AROUND 230 PM/1930Z.
THEN THE NEXT SURGE OF MOISTURE COMING UP CENTRAL IL WILL REACH
SOUTHERN WI RIGHT AROUND THE SAME TIME AS THE SURFACE COLD FRONT. IT
WILL BE SATURATED THROUGH THE WHOLE COLUMN...YIELDING EFFICIENT
PRECIPITATION AND LOW CLOUDS. THE TIMING OF MODERATE TO HEAVY RAIN
WILL BE RIGHT AROUND 00Z ACROSS ALL OF THE FORECAST AREA...BEGINNING
AROUND 23Z IN THE WESTERN FORECAST AREA. THIS IS THE TIME THE UPPER
DIVERGENCE FROM THE 250MB JET RAPIDLY INCREASES DIRECTLY
OVERHEAD...THE OMEGA VALUES SPIKE...AND THE LEFT EXIT REGION OF THE
850MB JET PUSHES INTO THE AREA.
THERE WILL BE ABOUT A 3 HOUR PERIOD OF MODERATE TO HEAVY RAIN LIKELY
TOTALING 0.75 TO 1 INCH. RAP SOUNDINGS SHOW CAPE VALUES AROUND 100
J/KG FOR A TIME AND GIVEN THE STRONG DYNAMICS...STILL EXPECTING
ISOLATED THUNDER.
MODELS ARE NOW SHOWING DRY AIR IN THE MID AND UPPER LEVELS PUSHING
IN FROM THE WEST BEHIND THE FRONT RATHER QUICKLY. THERE IS
UNCERTAINTY IN HOW QUICKLY THE LOWEST LEVELS WILL DRY OUT. WE COULD
SEE VERY LOW CLOUDS AND DRIZZLE HANG AROUND THROUGH THE REST OF THE
NIGHT INTO THURSDAY MORNING...OR THE DRY AIR AND LOW DEW POINTS WILL
ADVECT INTO HERE AND CLOUD BASES WILL LIFT AND EVENTUALLY SCATTER
OUT MID THU MORNING.
.THURSDAY...FORECAST CONFIDENCE MEDIUM.
THERE SHOULD BE A BREAK IN PRECIP DURING THE MORNING HOURS. THEN
ANOTHER ROUND OF LIGHT RAIN SHOWERS SHOULD SPREAD ACROSS SOUTHERN WI
THU AFTERNOON AS THE UPPER LOW PARKS OVER CENTRAL WI AND VORT MAXES
ROTATE AROUND IT. STEEP LOW LEVEL LAPSE RATES AND COLD CLOUDS MAY
LEAD TO ENOUGH INSTABILITY TO GENERATE GRAUPEL AND A CLAP OF THUNDER
IN A FEW SHOWERS. LEFT THE MENTION OUT OF THE FORECAST FOR NOW...BUT
KNOW THAT IT IS A POSSIBILITY.
MAX TEMPS ON THU WILL ONLY REACH THE UPPER 40S TO AROUND 50 WITH
AMPLE CLOUD COVER AND INTERMITTENT SHOWERS. WINDS MAY BECOME GUSTY
FOR A TIME OUT OF THE SOUTHWEST...DEPENDING ON CLOUD COVER.
.THURSDAY NIGHT AND FRIDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
THE LARGE NEARLY STATIONARY UPPER LOW CENTERED OVER SOUTHEAST
WISCONSIN BEGINS TO FILL FRIDAY AS IT ONLY REACHES LAKE MICHIGAN
FRIDAY AFTERNOON. IN THE MID LEVELS AT 500 MB SEVERAL AREAS OF
CYCLONIC VORTICITY WRAP AROUND THE MID/UPPER LOW.
THE BEST CHANCE FOR MODERATE RAIN RAIN WILL BE THURSDAY EVENING
ESPECIALLY FAR SOUTHEAST...BUT EXPECT INTERMITTENT LIGHT RAIN
FOR THIS PERIOD WITH CLOUDY SKIES AND COOL TEMPERATURES. 850 MB RH
VALUES NEAR 100 PERCENT. DUE TO RATHER STEEP LOW LEVEL LAPSE RATES
OF 9.5 CELSIUS/KM AT 850 MB THE NAM HAS SOME WEAK ZERO TO 1 KM
CAPE OF AROUND 50 J/KG.
.FRIDAY NIGHT AND SATURDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
THE GFS IS QUICKER IN PUSHING THE UPPER LOW OFF TO THE NORTHEAST.
THE SLOWER 12Z NAM IS MORE LIKE THE 00Z ECMWF AND IS PREFERRED.
THEREFORE EXPECT THE UPPER LOW TO WEAKEN AND SLOWLY PROGRESS TO THE
EAST...REACHING LOWER MICHIGAN SATURDAY. SOUTHERN WISCONSIN WILL
BE IN THE NORTHWEST CYCLONIC FLOW OF THE UPPER LOW WITH DRYING
OCCURRING AT 700 MB. STILL EXPECT LINGERING STRATOCUMULUS CLOUDS
ESPECIALLY OVER SOUTHEAST WISCONSIN DUE TO LINGERING MOISTURE IN
THE LOW LEVELS.
.LONG TERM...
.SUNDAY THROUGH TUESDAY...FORECAST CONFIDENCE...MEDIUM
A WEAK UPPER RIDGE WILL BUILD INTO THE WISCONSIN AREA ON SUNDAY
WITH A SOUTHWEST FLOW MONDAY AND TUESDAY. THE 12Z GFS/00Z ECMWF
AND 06Z DGEX ALL TAKE A WEAK SHORTWAVE ACROSS THE KANSAS AREA
MONDAY PUSHING IT NORTHEAST INTO ILLINOIS AND POSSIBLY SOUTHERN
WISCONSIN ON TUESDAY.
THICKNESS VALUES WARM TO AROUND 564 DECAMETERS BY SUNDAY AFTERNOON
RESULTING IN MILD TEMPERATURES. THE MAIN FORECAST PROBLEM WILL BE
A DEVELOPING SURFACE TROUGH OF LOW PRESSURE OVER KANSAS THAT LIFTS
NORTHEAST TOWARD SOUTHERN WISCONSIN ON MONDAY. THE MODELS ALL
BRING LIGHT PRECIPITATION INTO SOUTHERN WISCONSIN ON
MONDAY...WHILE THE 00Z ECMWF AND 06Z DGEX LINGER THE TROUGH AND
PRECIPITATION ON TUESDAY. PREFER THE 00Z ECMWF/06Z DGEX SO WILL
CONTINUE TO PUT A CHANCE OF SHOWERS FOR MONDAY AND TUESDAY.
.WEDNESDAY AND THURSDAY...FORECAST CONFIDENCE...MEDIUM TO LOW
THE NEXT MID/UPPER TROUGH MOVES INTO THE WEST COAST OF THE U.S.
WEDNESDAY...RESULTING IN A WEAK RIDGE ACROSS THE MISSISSIPPI
VALLEY AND INTO SOUTHERN WISCONSIN EARLY WEDNESDAY AS THE WEST TO
SOUTHWEST FLOW BECOMES MORE SOUTHWEST. THE 12Z GFS BRINGS OUT A
STRONG TROUGH/UPPER LOW INTO THE NORTHERN PLAINS ON
THURSDAY...WHILE THE 00Z ECMWF WAS A LITTLE SLOWER BRINGING THE
TROUGH NORTHEAST. NOW THE 12Z ECMWF HAS TRENDED TOWARD THE 12Z GFS.
THIS WOULD BRING A CHANCE OF SHOWERS NEAR AN ADVANCING WARM FRONT
WEDNESDAY MORNING. EVEN THOUGH THE 12Z ECMWF HAS TRENDED TOWARD
THE 12Z GFS WITH THE STRONGER FASTER SHORTWAVE...THE 00Z ECMWF
AND 12Z STILL KEEPS SOUTHERN WISCONSIN IN A DRY WARM SECTOR
WEDNESDAY NIGHT AND THURSDAY MORNING UNTIL THE ADVANCING COLD
FRONT REACHES THE FORECAST AREA THURSDAY AFTERNOON. BOTH THE 12Z
GFS AND 12Z ECMWF NOW BRING A STRONG LOW INTO MINNESOTA THURSDAY.
HOWEVER LITTLE CONSISTENCY BETWEEN MODEL RUNS SO CONFIDENCE IS
STILL LOWER EVEN THOUGH BOTH THE GFS AND ECMWF ARE NOW IN BETTER
AGREEMENT.
&&
.AVIATION/00Z TAFS/...
A COLD FRONT STEMMING FROM LOW PRESSURE IN THE NORTHERN PLAINS...
STRETCHING FROM MINNESOTA DOWN TO MISSOURI...WILL PUSH EAST ACROSS
WISCONSIN AND ILLINOIS THIS EVENING. A LEADING SURGE OF ENERGY LED
TO SCATTERED SHOWERS ACROSS SOUTHERN WI THIS AFTERNOON.
THEN ABUNDANT MOISTURE WITH STRONG DYNAMICAL FORCING WILL STREAM
NORTH INTO SOUTHERN WISCONSIN LATE THIS AFTERNOON. WIDESPREAD
MODERATE TO HEAVY RAINFALL AND ISOLATED THUNDERSTORMS WILL EXPAND
RAPIDLY BETWEEN 23Z AND 01Z THIS EVENING AND LAST AROUND 3 HOURS. AN
ASSOCIATED COLD FRONT WILL REACH MADISON AROUND OR SHORTLY AFTER 00Z
THU...AND THE MILWAUKEE AREA BY AROUND 04Z THU. WINDS WILL SHIFT
FROM SOUTH SOUTHWEST...TO WEST NORTHWEST IN THE WAKE OF THE
FRONT...THEN GRADUALLY SHIFT BACK TO THE SOUTH TOWARD MORNING.
LOOK FOR VFR CONDITIONS TO RAPIDLY DETERIORATE BY EARLY EVENING...
AND EVENTUALLY GO DOWN TO IFR WITH THE RAIN THIS EVENING. IT IS
LIKELY THAT TAF SITES WILL GO BELOW ALTERNATE MINIMUMS FOR CIGS AND
VSBY FOR A TIME MAYBE AROUND MIDNIGHT ALONG WITH DRIZZLE AFTER THE
MAIN RAIN EVENT ENDS AND BEFORE THE DRIER AIR GETS HERE.
&&
.MARINE...A LARGE LOW PRESSURE SYSTEM STRETCHING FROM THE NORTHERN
PLAINS...THROUGH MISSOURI WILL MOVE EAST TONIGHT AND AN ASSOCIATED
COLD FRONT WILL PUSH THROUGH THE NEARSHORE WATERS LATER THIS EVENING
AND OVERNIGHT. SOUTH WINDS OF 15 TO 25 KNOTS WITH WAVES RANGING FROM
4 TO 7 FEET WILL GRADUALLY DIMINISH BEHIND THE COLD FRONT.
THEREAFTER... WINDS WILL SHIFT TO THE WEST NORTHWEST OVERNIGHT...AND
THEN BACK TO THE SOUTHWEST ON THURSDAY. THERE MAY BE A FEW GUSTS TO
25 KNOTS DURING THE DAY ON THURSDAY...BUT NOT EXPECTING A SMALL
CRAFT ADVISORY AT THIS TIME.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 11 PM CDT THIS EVENING FOR LMZ645-646.
SMALL CRAFT ADVISORY UNTIL 4 AM CDT THURSDAY FOR LMZ643-644.
&&
$$
TONIGHT/THURSDAY AND AVIATION/MARINE...MRC
THURSDAY NIGHT THROUGH WEDNESDAY...HENTZ
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1145 AM CDT WED OCT 17 2012
.UPDATE...
A SHORTWAVE MOVING INTO SOUTHERN WI WILL LIKELY BRING SCATTERED
SHOWERS AND A FEW THUNDERSTORMS TO SOUTHERN WI BETWEEN NOW AND 21Z.
THIS INITIAL SURGE WILL HAVE HIGHER CLOUD BASES...AROUND 6000 FEET.
THEN WE WILL WAIT FOR THE NEXT SURGE OF MOISTURE COMING UP FROM THE
SOUTHWEST AND COINCIDENT WITH THE SURFACE COLD FRONT. IT WILL BE
SATURATED THROUGH THE WHOLE COLUMN...YIELDING EFFICIENT
PRECIPITATION AND LOW CLOUDS. THE TIMING OF MODERATE TO HEAVY RAIN
WILL BE RIGHT AROUND 00Z ACROSS ALL OF THE FORECAST AREA...BEGINNING
AROUND 23Z IN THE WESTERN FORECAST AREA. THIS IS THE TIME THE UPPER
DIVERGENCE FROM THE 250MB JET RAPIDLY INCREASES DIRECTLY
OVERHEAD...THE OMEGA VALUES SPIKE...AND THE LEFT EXIT REGION OF THE
850MB JET PUSHES INTO THE AREA.
THERE WILL BE ABOUT A 3 HOUR PERIOD OF MODERATE TO HEAVY RAIN LIKELY
TOTALING 0.75 TO 1 INCH. RAP SOUNDINGS SHOW CAPE VALUES AROUND 100
J/KG FOR A TIME AND GIVEN THE STRONG DYNAMICS...STILL EXPECTING
ISOLATED THUNDER.
UPDATED FORECAST TO REFLECT A MORE SCATTERED NATURE OF SHOWERS EARLY
IN THE AFTERNOON...AND THEN THE STEADY RAIN AROUND 00Z THROUGH 03Z.
WILL BE TAPERING OFF THE RAIN QUICKLY AFTER MIDNIGHT AS THE LATEST
MODELS ARE SHOWING THE DRY AIR MOVING IN EARLIER. WE COULD SEE VERY
LOW CLOUDS AND DRIZZLE HANG AROUND THROUGH THE REST OF THE NIGHT AND
THURSDAY MORNING. THEN ANOTHER ROUND OF SHOWERS SHOULD SPREAD ACROSS
SOUTHERN WI THU AFTERNOON.
&&
.AVIATION/18Z TAFS/...LOOK FOR VFR CONDITIONS THROUGH EARLY
AFTERNOON...FOLLOWED BY RAPIDLY DETERIORATING CONDITIONS...
EVENTUALLY GOING DOWN TO IFR FOR TONIGHT INTO THURSDAY. IT IS LIKELY
THAT TAF SITES WILL GO BELOW ALTERNATE MINIMUMS FOR CIGS AND VSBY
FOR A TIME LATE TONIGHT ALONG WITH DRIZZLE AFTER THE MAIN RAIN EVENT
ENDS.
A LARGE LOW PRESSURE SYSTEM STRETCHING FROM THE NORTHERN PLAINS...
DOWN TO MISSOURI AND KANSAS WILL PUSH EAST TODAY. THERE WILL BE SOME
SCATTERED SHOWERS IN THE AREA THIS AFTERNOON. THEN ABUNDANT MOISTURE
WILL STREAM NORTH INTO SOUTHERN WISCONSIN LATE THIS AFTERNOON.
WIDESPREAD MODERATE TO HEAVY RAINFALL AND ISOLATED THUNDERSTORMS WILL
EXPAND ABRUPTLY BETWEEN 23Z AND 01Z THIS EVENING AND LAST AROUND 3
HOURS. AN ASSOCIATED COLD FRONT WILL REACH MADISON AROUND OR SHORTLY
AFTER 00Z THU...AND THE MILWAUKEE AREA BY AROUND 04Z THU. WINDS
WILL SHIFT FROM SOUTH SOUTHWEST...TO WEST NORTHWEST IN THE WAKE OF
THE FRONT.
DRY AIR IN THE MID AND UPPER LEVELS WILL QUICKLY MOVE IN BEHIND THE
COLD FRONT AFTER MIDNIGHT. THERE COULD BE LINGERING LOW LEVEL
MOISTURE LEADING TO LOW CLOUDS AND LIGHT FOG AND POSSIBLY DRIZZLE.
&&
.PREV DISCUSSION... /ISSUED 340 AM CDT WED OCT 17 2012/
TODAY AND TONIGHT...FORECAST CONFIDENCE...HIGH
ALL THE MODELS ARE IN VERY GOOD AGREEMENT THAT SOUTHERN WISCONSIN
WILL BE HIT WITH A WIDESPREAD AND RATHER GENEROUS RAINFALL OVER THE
NEXT 24 HOURS. THE BULK OF THE RAIN WILL HIT FROM MID AFTERNOON
THROUGH THE OVERNIGHT HOURS AND COULD EXCEED 1 INCH IN SOME SPOTS.
A MID LEVEL TROF WILL DIG INTO THE NORTHERN PLAINS TODAY AND QUICKLY
CLOSE OFF INTO A LARGE AND AMPLIFYING UPPER LOW CENTERED AROUND
SOUTHERN MINNESOTA LATER TONIGHT. A SHORT WAVE ROTATING AROUND THE
BASE OF THE LOW WILL FORCE THE UPPER LOW INTO A NEGATIVE TILT
ORIENTATION FOR A TIME THIS EVENING. THE DEEP UPWARD VERTICAL MOTION
BLOSSOMS AT THIS POINT AND WE SHOULD SEE THE RAINFALL BECOME MORE
WIDESPREAD AND HEAVIER AT THAT POINT. MOISTURE WILL BE IN PLACE WITH
PRECIPITABLE WATER VALUES OF 1-1.2 INCHES EXPECTED. BY EARLY
EVENING...THE COLD FRONT ASSOCIATED WITH THE DEEPENING SURFACE LOW
WILL BE NEAR MADISON ALREADY. SO THE HEAVIEST RAIN WILL LIKELY BE
FOUND FROM MADISON ON EASTWARD. GIVEN THE OVERWHELMING CONSENSUS ON
RAINFALL...HAVE BUMPED POPS OVER THE EASTERN HALF OF THE CWA TO 100
PERCENT. THERE CONTINUES TO BE SOME ELEVATED INSTABILITY...SO WILL
CONTINUE MENTION OF ISOLATED THUNDER.
THE FRONT WILL SPIN OFF TO THE NORTH AND OCCLUDE OVERNIGHT. WILL
CONTINUE HIGH POPS ACROSS THE FAR NORTH AND DIMINISH ACROSS THE
SOUTH AS THIS SYSTEM STARTS TO BECOME A STACKED AND STUBBORN CUTOFF
LOW FOR THE REMAINDER OF THE WEEK.
THURSDAY FRIDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
LARGE AND DEEP UPPER LOW TO MOVE SLOWLY FROM NEARLY RIGHT OVER THE
FORECAST AREA THURSDAY EVENING ONLY TO LOWER MICHIGAN BY FRIDAY
EVENING. NEEDLESS TO SAY...GOOD CHANCE FOR CLOUDS...RAIN...AND
COOLER TEMPERATURES FOR THE LATTER HALF OF THE WORK WEEK.
BEST CHANCE FOR SHOWERS THURSDAY AND THURSDAY NIGHT EXPECTED TO BE
ACROSS SOUTHERN PORTIONS OF THE FORECAST AREA CLOSER TO THE SURFACE
LOW. SHOULD SEE BEST CHANCE FOR SHOWERS IN THE EAST FRIDAY DUE TO
LAKE ENHANCEMENT UNDER EASTERLY FLOW...WITH SFC-850 MB TEMP
DIFFERENCE INCREASING TO AROUND 14C. TEMPS WILL BE BELOW NORMAL BOTH
THURSDAY AND FRIDAY...WITH HIGHS STRUGGLING INTO THE UPPER 40S OR
LOW 50S.
SATURDAY AND SUNDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
TEMPERATURES SHOULD WARM TO NEAR NORMAL SATURDAY THEN A FEW DEGREES
ABOVE NORMAL SUNDAY AS UPPER RIDGING BUILDS INTO THE AREA. SHOULD BE
DRY THROUGH THE WEEKEND.
MONDAY AND TUESDAY...FORECAST CONFIDENCE...LOW TO MEDIUM
MODELS JUMPING AROUND QUITE A BIT WITH THE FORECAST FOR EARLY NEXT
WEEK. MAIN ISSUE IS HOW LONG MILDER AIR WILL STICK AROUND AND
RESULTANT PRECIP CHANCES DUE TO WARM AIR ADVECTION AND EVENTUAL
ARRIVAL OF COOLER AIR. TEMPERATURES TRICKY TOO...AS 925 MB TEMPS
SUPPORT HIGHS MILDER THAN THE CURRENT FORECAST. DID NOT GET THAT
AGGRESSIVE WITH WARMING UP TEMPS DUE TO INCONSISTENCY IN THE
MODELS...ALONG WITH CLOUDS AND POSSIBLE PRECIP. WILL LIKELY NEED
TO WARM THINGS UP THOUGH IF MODELS DO STICK WITH THE CURRENT
MILDER SOLUTION.
WITH EXPECTED WARM AIR ADVECTION AND A WEAK WAVE OR TWO IN THE
FLOW...KEPT SHOWER CHANCES GOING. ECMWF AND GFS BOTH SHOWING SOME
ELEVATED INSTABILITY...SO ADDED SLIGHT CHANCE OF THUNDER INTO THE
FORECAST.
AVIATION/12Z TAFS/...LOOK FOR VFR CONDITIONS THROUGH EARLY
AFTERNOON...FOLLOWED BY RAPIDLY DETERIORATING CONDITIONS...
EVENTUALLY GOING DOWN TO IFR FOR TONIGHT INTO THURSDAY.
A LARGE LOW PRESSURE SYSTEM STRETCHING FROM THE NORTHERN
PLAINS...DOWN TO MISSOURI AND KANSAS WILL PUSH EAST TODAY. ABUNDANT
MOISTURE WILL STREAM NORTH INTO SOUTHERN WISCONSIN THIS AFTERNOON
WITH WIDESPREAD RAINFALL AND ISOLATED THUNDERSTORMS BY LATE
AFTERNOON AND EVENING. AN ASSOCIATED COLD FRONT WILL REACH MADISON
AROUND OR SHORTLY AFTER 00Z THU...AND THE MILWAUKEE AREA BY AROUND
06Z THU. WINDS WILL SHIFT FROM SOUTH SOUTHWEST...TO WEST NORTHWEST
IN THE WAKE OF THE FRONT.
MARINE...SOUTH WINDS OF 15 TO 25 KNOTS WILL CONTINUE TODAY AND
INTO THE EVENING WITH WAVES RANGING FROM 4 TO 7 FEET. A LARGE LOW
PRESSURE SYSTEM STRETCHING FROM THE NORTHERN PLAINS...THROUGH
MISSOURI THIS MORNING WILL MOVE SLOWLY EAST TODAY. AN ASSOCIATED
COLD FRONT WILL PUSH THROUGH THE NEARSHORE WATERS LATER THIS EVENING
AND OVERNIGHT. THEREAFTER...WINDS WILL SHIFT TO THE WEST
NORTHWEST.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 11 PM CDT THIS EVENING FOR LMZ645-646.
SMALL CRAFT ADVISORY UNTIL 4 AM CDT THURSDAY FOR LMZ643-644.
&&
$$
UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...DAVIS
THURSDAY THROUGH TUESDAY...DDV