Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/22/12
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
845 PM EST WED NOV 21 2012
.UPDATE...
01Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AN AMPLIFIED UPPER LEVEL
TROUGH OVER THE SE CONUS COAST. THE TROUGH AXIS NOW EAST OF OUR
FORECAST AREA AND CONTINUING TO EXIT. IMPRESSIVE DEEP LAYER
SUBSIDENCE BEHIND THIS TROUGH IS SHOWN IN THE GFS/ECMWF QVECTOR
DIVERGENCE FIELDS AND IN AN EXPANDING AREA OF VERY DRY MID/UPPER
LEVEL AIR OVER THE REGION ON WV IMAGERY. 00Z KTBW SOUNDING PROFILE
HAS SAMPLED THIS DRY AIR QUITE WELL WITH IMPRESSIVE DEWPOINT
DEPRESSION ABOVE 800MB THROUGH THE EXTENT OF THE TROPOSPHERE. PW
VALUES HAS CONTINUED TO DROP AND IS NOW ONLY AROUND 0.6".
THE DRY COLUMN HAS ALLOWED SKIES TO CLEAR ACROSS THE REGION AND
CLEAR TO MOSTLY CLEAR SKIES WILL BE THE FORECAST THROUGH YOUR
THANKSGIVING DAY. TEMPERATURES OVERNIGHT WILL BECOME RATHER
COOL/CHILLY BY SUNRISE WITH MANY LOCATIONS AWAY FROM THE IMMEDIATE
COAST DROPPING INTO THE UPPER 40S TO AROUND 50. NORMALLY COLDER
LOCATIONS FROM BROOKSVILLE NORTHWARD TO LEVY COUNTY MAY BRIEFLY DIP
INTO THE LOWER/MID 40S BY SUNRISE. DESPITE THE COOL EARLY MORNING
TEMPS...NEAR 100% OF THE POSSIBLE INSOLATION DURING THE DAY ON
THURSDAY WILL HELP TEMPERATURES RECOVER BACK TO AROUND 70 NORTH AND
THE LOWER/MID 70S SOUTH OF TAMPA BAY. THESE TEMPS ARE STILL SEVERAL
DEGREES BELOW NORMAL BUT IN THE SEASONABLE RANGE. A LIGHT JACKET MAY
REMAIN A GOOD IDEA FOR ANY OUTDOOR FESTIVITIES ON THURSDAY AS A
BRISK NORTH WIND WILL MAKE IT FEEL A BIT COOLER. PLUS...ONCE WE PASS
5PM...AND THE SUN STARTS TO SINK TOWARD THE HORIZON...A GOOD
RADIATIONAL COOLING SETUP WILL ALLOW TEMPS TO FALL RATHER QUICKLY
FOR ANY EVENING ACTIVITIES. ENJOY!
&&
.AVIATION...
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. WINDS BECOMING GUSTY
BY LATE THURSDAY MORNING TO AROUND 20 KNOTS AT TIMES OUT OF THE
NORTH. WINDS DIMINISHING THURSDAY EVENING WITH SUNSET.
&&
.MARINE...
LOCAL GRADIENT WILL REMAIN TIGHT OVER THE EASTERN GULF OF MEXICO
BETWEEN A RIDGE OF HIGH PRESSURE ALONG THE NORTHERN GULF COAST AND
AN ELONGATED AREA OF LOW PRESSURE OFF THE GEORGIA/CAROLINA
COASTLINE. NORTHERLY WINDS OVERNIGHT WILL COME VEER MORE TO THE
NORTHEAST FOR THE DAY ON THURSDAY. WINDS WILL REACH EXERCISE CAUTION
LEVELS AT TIMES THROUGH THURSDAY EVENING BEFORE WINDS DIMINISH FOR
FRIDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 53 72 50 73 / 0 0 0 10
FMY 52 73 50 75 / 0 0 0 0
GIF 49 71 48 71 / 0 0 0 10
SRQ 52 73 50 73 / 0 0 0 0
BKV 43 71 39 73 / 0 0 0 10
SPG 56 71 55 71 / 0 0 0 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...FIRE WEATHER WATCH THURSDAY AFTERNOON FOR LEE-PINELLAS-
SARASOTA.
GULF WATERS...NONE.
&&
$$
UPDATE/MARINE...MROCZKA
AVIATION...CLOSE
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
629 AM EST TUE NOV 20 2012
.SYNOPSIS...
THE REGION WILL REMAIN BETWEEN HIGH PRESSURE EXTENDING FROM NEW
ENGLAND TO THE LOWER MISSISSIPPI VALLEY AND LOW PRESSURE OVER THE
WESTERN ATLANTIC THROUGH THURSDAY. A COLD FRONT WILL THEN APPROACH
FROM THE NORTHWEST LATE FRIDAY INTO SATURDAY...WITH HIGH PRESSURE
REBUILDING FROM THE WEST EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO MAJOR CHANGES WERE MADE FOR THE SUNRISE UPDATE. MADE MINOR
ADJUSTMENTS TO THE TIMING AND SOUTHWESTERN EXTENT OF LOW
CLOUDS MOVING ACROSS THE CHARLESTON TRI-COUNTY AREA.
HIGH PRESSURE WILL REMAIN ANCHORED OVER THE REGION TODAY AS A
LARGE OCEANIC STORM MEANDERS WELL OF THE U.S. EAST COAST. A FAIRLY
ZONAL FLOW WILL DOMINATE ALOFT AS SHORTWAVE ENERGY OVER THE
NORTHERN MISSISSIPPI VALLEY BEGINS TO DIG SOUTH.
THERE IS MUCH UNCERTAINTY ON HOW MUCH CLOUD COVER WILL OCCUR
TODAY. CIRRUS BEING ENHANCED BY THE LEFT EXIT REGION OF A 115 KT
JET STREAK WILL OVERSPREAD THE AREA FROM THE WEST LATER TODAY AS
THE SUBTROPICAL JET AXIS DROPS FARTHER TO THE SOUTH AND EAST.
MEANWHILE LOW CLOUDS SPREADING SOUTHWEST OUT OF NORTH CAROLINA ARE
POISED TO MOVE INTO THE CHARLESTON TRI-COUNTY AREA BY SUNRISE.
975MB RUC MOISTURE PROGS SUGGEST MUCH OF THIS LOW-LEVEL CLOUD
COVER WILL MIX OUT LATER THIS MORNING AS TEMPERATURES WARM WITH
SKIES BECOMING PARTLY CLOUDY LATER TODAY ACROSS A GOOD PORTION OF
THE AREA. HOWEVER...THERE REMAINS MUCH UNCERTAINTY ON EXACTLY HOW
THE SKY COVER FORECAST WILL PLAY OUT WITH SOME GUIDANCE SUGGESTING
SKIES WILL REMAIN MOSTLY CLOUDY FOR A GOOD PORTION OF THE DAY.
LATER SHIFTS WILL MOST CERTAINLY HAVE TO MADE SOME ADJUSTMENTS AS
THE DAY PROGRESSES. HIGHS WILL TOP OUT IN THE MID-UPPER 60S...
WARMEST ACROSS THE SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
TONIGHT...SIMILAR TO MONDAY EVENING...SKIES SHOULD CLEAR A BIT
WITH THE LOSS OF INSOLATION. MORE RAPID CLEARING IS EXPECTED TO
OCCUR AFTER MIDNIGHT AS THE CORE OF THE AFOREMENTIONED SHORTWAVE
DIGS TO THE WEST AND SOUTH...THUS SHUNTING THE SUBTROPICAL JET FAR
TO THE SOUTH. EXPECT MOSTLY CLEAR SKIES TO DOMINATE BETWEEN
MIDNIGHT AND SUNRISE WEDNESDAY. THE BOUNDARY LAYER SHOULD DECOUPLE
FAIRLY QUICKLY THIS EVENING. CALM/LIGHT WINDS COUPLED WITH
CLEARING SKIES WILL YIELD IMPROVING RADIATIONAL CONDITIONS
OVERNIGHT. LOWS WILL RANGE FROM THE LOWER 40S WELL INLAND TO THE
UPPER 40S AT THE COAST.
WEDNESDAY AND THURSDAY...AN AMPLIFIED UPPER TROUGH WILL CROSS THE
EAST COAST STATES WEDNESDAY MORNING AND MOVE OFFSHORE LATER IN THE
DAY. WHILE THE DEPARTING UPPER TROUGH STRENGTHENS THE ATLANTIC
SURFACE LOW FAR OUT TO SEA...SURFACE HIGH PRESSURE AND UPPER RIDGING
WILL BUILD IN FROM THE WEST. HIGH PRESSURE AT THE SURFACE AND ALOFT
WILL THEN DOMINATE THE PATTERN OVER THE LAND AREAS THROUGH THURSDAY.
LACKING ANY DEEP MOISTURE AS THE UPPER TROUGH PASSES THE REGION
WEDNESDAY...FOLLOWED BY LITTLE UPPER LEVEL SUPPORT IN ITS
WAKE...EXPECT DRY WEATHER TO PREVAIL THROUGH AT LEAST THURSDAY. HIGH
TEMPERATURES WILL TREND BACK UP TOWARD SEASONAL NORMALS...REACHING
THE MID TO UPPER 60S EACH AFTERNOON. NIGHTTIME LOW TEMPERATURES WILL
ACTUALLY FALL BELOW NORMAL...AS DECOUPLING WINDS AND CLEAR SKIES
SUPPORT IDEAL RADIATIONAL COOLING. LOW TEMPERATURES WEDNESDAY NIGHT
WILL RANGE FROM AROUND 40 DEGREES WELL INLAND TO THE MID 40S NEAR
THE COAST...AND THEN FALL TO EVEN COOLER LEVELS THURSDAY NIGHT IN
THE UPPER 30S TO AROUND 40S MOST LOCATIONS AWAY FROM THE IMMEDIATE
COAST.
FRIDAY...AN UPPER LOW WELL TO THE NORTH WILL MOVE ACROSS THE GREAT
LAKES REGION AND INTO THE NEW ENGLAND STATES LATE IN THE
WEEK. THE RIDGING ALOFT WILL BREAK DOWN AHEAD OF THE MAIN TROUGH
AXIS...ALLOWING A COLD FRONT TO RAPIDLY APPROACH FROM THE
NORTHWEST. WEST TO NORTHWEST FLOW REMAIN PROMINENT THROUGHOUT THE
PROFILE AS THE FRONT NEARS THE REGION...SUGGESTING THE FEATURE
WILL LACK A DECENT TAP INTO MOISTURE. THUS EXPECT DRY CONDITIONS
TO CONTINUE INTO FRIDAY. HIGH TEMPERATURES FRIDAY AFTERNOON COULD
BE THE WARMEST OF THE PERIOD...LIKELY DUE TO PRE-FRONTAL COMPRESSION
AND WINDS BRIEFLY BACKING TO THE SOUTHWEST.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
A COLD FRONT WILL DROP SOUTHEAST THROUGH THE FORECAST AREA LATE
FRIDAY INTO EARLY SATURDAY...AS AN UPPER TROUGH CROSSES THE MID
ATLANTIC COASTLINE BY SATURDAY AFTERNOON. ALTHOUGH THE FRONT IS
NOT EXPECTED TO BRING PRECIPITATION TO THE AREA...STRONG COLD
ADVECTION WILL FOLLOW IN ITS WAKE THROUGH THE WEEKEND. HIGH
TEMPERATURES ON SATURDAY WILL BE IN THE MID TO UPPER 60S...THEN
TREND EVEN COOLER IN THE LOWER 60S FOR SUNDAY AFTERNOON. BROAD
SURFACE HIGH PRESSURE WILL STEADILY SLIP FROM THE LOWER
MISSISSIPPI VALLEY TOWARD THE SOUTHEAST STATES THROUGH SUNDAY
WITHIN PROGRESSIVE ZONAL FLOW ALOFT. ANOTHER LOW PRESSURE SYSTEM
WILL APPROACH FROM THE WEST MONDAY THROUGH TUESDAY...BUT TIMING
AND IMPACTS ARE TOO UNCERTAIN THIS FAR OUT. WILL THUS MAINTAIN
RAIN CHANCES LESS THAN 15 PERCENT THROUGH THE EXTENDED PERIOD.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
KCHS...LOW CLOUDS ARE ON THE CUSP OF MOVING ACROSS THE TERMINAL.
EXPECT LOW-END MVFR CIGS OF 1000-1200 FT TO OCCUR THROUGH ABOUT
15Z AFTER WHICH RAP SOUNDING SHOW THE LOW CLOUD DECK MIXING OUT.
EXPECT VFR TO PREVAIL THROUGH THE REMAINDER OF THE 12Z TAF PERIOD
ONCE THIS OCCURS. THERE IS A CHANCE THAT CIGS MAY BRIEFLY DROP TO
IFR...BUT PROBABILITIES REMAIN FAIRLY LOW AND THERE ARE NO
INDICATIONS THAT CIGS WILL DROP BELOW ALTERNATE MINIMUMS.
KSAV...VFR.
EXTENDED AVIATION OUTLOOK...THERE NO SIGNIFICANT ISSUES.
&&
.MARINE...
TODAY...THE MARINE AREA WILL SEE IMPROVING CONDITIONS THROUGH THE
DAY. SEAS STILL LOOK TO REMAIN ABOVE 6 FT ACROSS THE CHARLESTON
COUNTY COASTAL WATERS UNTIL LATE MORNING SO FLAGS WILL BE EXTENDED
BY A FEW HOURS WITH SEAS 2-4 FT OVER THE REMAINING NEARSHORE LEGS.
SEAS OF 6-8 FT ARE FORECAST TO REMAIN OVER THE GEORGIA OFFSHORE
WATERS THROUGH THE AFTERNOON SO A SMALL CRAFT ADVISORY WILL REMAIN
IN FORCE THERE.
TONIGHT...SHOULD SEE A BIT OF AN INCREASE IN WINDS OVERNIGHT IN
RESPONSE TO SHORTWAVE ENERGY APPROACHING FROM THE WEST. SPEEDS
SHOULD BE NO HIGHER 15-20 KT OVER THE OFFSHORE WATERS WITH 10-15
KT CLOSER TO THE COAST. SEAS WILL RANGE FROM 2-4 FT NEARSHORE
WATERS TO 5-7 FT OFFSHORE WATERS. A SMALL CRAFT ADVISORY WILL
REMAIN IN EFFECT OVERNIGHT FOR THE GEORGIA OFFSHORE LEG.
WEDNESDAY THROUGH SATURDAY...WINDS AND SEAS WILL REMAIN ELEVATED
THROUGH MID WEEK...AS THE PRESSURE GRADIENT REMAINS ENHANCED
OVER THE WATERS BETWEEN BROAD HIGH PRESSURE INLAND AND A LOW
PRESSURE SYSTEM FARTHER OUT IN THE ATLANTIC. WINDS AND SEAS WILL
REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS FOR NEARSHORE
WATERS. HOWEVER A COMBINATION OF NORTH/NORTHEAST WINDS...LONG
PERIOD SWELLS AND COLD ADVECTION ASSOCIATED WITH BUILDING HIGH
PRESSURE FROM THE WEST WILL ALLOW SMALL CRAFT ADVISORY CONDITIONS
TO PERSIST OVER OUTER GEORGIA WATERS THROUGH MID WEEK AND POSSIBLY
THROUGH LATE WEEK. CONDITIONS WILL THEN SLOWLY IMPROVE OVER ALL
WATERS LATE WEEK...AS THE LOW PRESSURE SYSTEM SHIFTS FURTHER
OFFSHORE AND THE PRESSURE GRADIENT WEAKENS ACCORDINGLY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST SATURDAY FOR AMZ374.
SMALL CRAFT ADVISORY UNTIL 11 AM EST THIS MORNING FOR AMZ350.
&&
$$
ST/79
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
358 AM EST TUE NOV 20 2012
.SYNOPSIS...
THE REGION WILL REMAIN BETWEEN HIGH PRESSURE EXTENDING FROM NEW
ENGLAND TO THE LOWER MISSISSIPPI VALLEY AND LOW PRESSURE OVER THE
WESTERN ATLANTIC THROUGH THURSDAY. A COLD FRONT WILL THEN APPROACH
FROM THE NORTHWEST LATE FRIDAY INTO SATURDAY...WITH HIGH PRESSURE
REBUILDING FROM THE WEST EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
HIGH PRESSURE WILL REMAIN ANCHORED OVER THE REGION TODAY AS A
LARGE OCEANIC STORM MEANDERS WELL OF THE U.S. EAST COAST. A FAIRLY
ZONAL FLOW WILL DOMINATE ALOFT AS SHORTWAVE ENERGY OVER THE
NORTHERN MISSISSIPPI VALLEY BEGINS TO DIG SOUTH.
THERE IS MUCH UNCERTAINTY ON HOW MUCH CLOUD COVER WILL OCCUR
TODAY. CIRRUS BEING ENHANCED BY THE LEFT EXIT REGION OF A 115 KT
JET STREAK WILL OVERSPREAD THE AREA FROM THE WEST LATER TODAY AS
THE SUBTROPICAL JET AXIS DROPS FARTHER TO THE SOUTH AND EAST.
MEANWHILE LOW CLOUDS SPREADING SOUTHWEST OUT OF NORTH CAROLINA ARE
POISED TO MOVE INTO THE CHARLESTON TRI-COUNTY AREA BY SUNRISE.
975MB RUC MOISTURE PROGS SUGGEST MUCH OF THIS LOW-LEVEL CLOUD
COVER WILL MIX OUT LATER THIS MORNING AS TEMPERATURES WARM WITH
SKIES BECOMING PARTLY CLOUDY LATER TODAY ACROSS A GOOD PORTION OF
THE AREA. HOWEVER...THERE REMAINS MUCH UNCERTAINTY ON EXACTLY HOW
THE SKY COVER FORECAST WILL PLAY OUT WITH SOME GUIDANCE SUGGESTING
SKIES WILL REMAIN MOSTLY CLOUDY FOR A GOOD PORTION OF THE DAY.
LATER SHIFTS WILL MOST CERTAINLY HAVE TO MADE SOME ADJUSTMENTS AS
THE DAY PROGRESSES. HIGHS WILL TOP OUT IN THE MID-UPPER 60S...
WARMEST ACROSS THE SOUTH.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
TONIGHT...SIMILAR TO MONDAY EVENING...SKIES SHOULD CLEAR A BIT
WITH THE LOSS OF INSOLATION. MORE RAPID CLEARING IS EXPECTED TO
OCCUR AFTER MIDNIGHT AS THE CORE OF THE AFOREMENTIONED SHORTWAVE
DIGS TO THE WEST AND SOUTH...THUS SHUNTING THE SUBTROPICAL JET FAR
TO THE SOUTH. EXPECT MOSTLY CLEAR SKIES TO DOMINATE BETWEEN
MIDNIGHT AND SUNRISE WEDNESDAY. THE BOUNDARY LAYER SHOULD DECOUPLE
FAIRLY QUICKLY THIS EVENING. CALM/LIGHT WINDS COUPLED WITH
CLEARING SKIES WILL YIELD IMPROVING RADIATIONAL CONDITIONS
OVERNIGHT. LOWS WILL RANGE FROM THE LOWER 40S WELL INLAND TO THE
UPPER 40S AT THE COAST.
WEDNESDAY AND THURSDAY...AN AMPLIFIED UPPER TROUGH WILL CROSS THE
EAST COAST STATES WEDNESDAY MORNING AND MOVE OFFSHORE LATER IN THE
DAY. WHILE THE DEPARTING UPPER TROUGH STRENGTHENS THE ATLANTIC
SURFACE LOW FAR OUT TO SEA...SURFACE HIGH PRESSURE AND UPPER RIDGING
WILL BUILD IN FROM THE WEST. HIGH PRESSURE AT THE SURFACE AND ALOFT
WILL THEN DOMINATE THE PATTERN OVER THE LAND AREAS THROUGH THURSDAY.
LACKING ANY DEEP MOISTURE AS THE UPPER TROUGH PASSES THE REGION
WEDNESDAY...FOLLOWED BY LITTLE UPPER LEVEL SUPPORT IN ITS
WAKE...EXPECT DRY WEATHER TO PREVAIL THROUGH AT LEAST THURSDAY. HIGH
TEMPERATURES WILL TREND BACK UP TOWARD SEASONAL NORMALS...REACHING
THE MID TO UPPER 60S EACH AFTERNOON. NIGHTTIME LOW TEMPERATURES WILL
ACTUALLY FALL BELOW NORMAL...AS DECOUPLING WINDS AND CLEAR SKIES
SUPPORT IDEAL RADIATIONAL COOLING. LOW TEMPERATURES WEDNESDAY NIGHT
WILL RANGE FROM AROUND 40 DEGREES WELL INLAND TO THE MID 40S NEAR
THE COAST...AND THEN FALL TO EVEN COOLER LEVELS THURSDAY NIGHT IN
THE UPPER 30S TO AROUND 40S MOST LOCATIONS AWAY FROM THE IMMEDIATE
COAST.
FRIDAY...AN UPPER LOW WELL TO THE NORTH WILL MOVE ACROSS THE GREAT
LAKES REGION AND INTO THE NEW ENGLAND STATES LATE IN THE
WEEK. THE RIDGING ALOFT WILL BREAK DOWN AHEAD OF THE MAIN TROUGH
AXIS...ALLOWING A COLD FRONT TO RAPIDLY APPROACH FROM THE
NORTHWEST. WEST TO NORTHWEST FLOW REMAIN PROMINENT THROUGHOUT THE
PROFILE AS THE FRONT NEARS THE REGION...SUGGESTING THE FEATURE
WILL LACK A DECENT TAP INTO MOISTURE. THUS EXPECT DRY CONDITIONS
TO CONTINUE INTO FRIDAY. HIGH TEMPERATURES FRIDAY AFTERNOON COULD
BE THE WARMEST OF THE PERIOD...LIKELY DUE TO PRE-FRONTAL COMPRESSION
AND WINDS BRIEFLY BACKING TO THE SOUTHWEST.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
A COLD FRONT WILL DROP SOUTHEAST THROUGH THE FORECAST AREA LATE
FRIDAY INTO EARLY SATURDAY...AS AN UPPER TROUGH CROSSES THE MID
ATLANTIC COASTLINE BY SATURDAY AFTERNOON. ALTHOUGH THE FRONT IS
NOT EXPECTED TO BRING PRECIPITATION TO THE AREA...STRONG COLD
ADVECTION WILL FOLLOW IN ITS WAKE THROUGH THE WEEKEND. HIGH
TEMPERATURES ON SATURDAY WILL BE IN THE MID TO UPPER 60S...THEN
TREND EVEN COOLER IN THE LOWER 60S FOR SUNDAY AFTERNOON. BROAD
SURFACE HIGH PRESSURE WILL STEADILY SLIP FROM THE LOWER
MISSISSIPPI VALLEY TOWARD THE SOUTHEAST STATES THROUGH SUNDAY
WITHIN PROGRESSIVE ZONAL FLOW ALOFT. ANOTHER LOW PRESSURE SYSTEM
WILL APPROACH FROM THE WEST MONDAY THROUGH TUESDAY...BUT TIMING
AND IMPACTS ARE TOO UNCERTAIN THIS FAR OUT. WILL THUS MAINTAIN
RAIN CHANCES LESS THAN 15 PERCENT THROUGH THE EXTENDED PERIOD.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
IT NOW APPEARS LOW CLOUDS STREAMING IN FROM NORTH CAROLINA AND
THE PEE DEE WILL REACH KCHS ROUGHLY BETWEEN 10-11Z. THIS WILL
RESULT IN PERIOD OF LOW-END MVFR CIGS THROUGH ABOUT 15Z. WHILE A
BRIEF STINT TO HIGH-END IFR CAN NOT BE RULED OUT...THEY SHOULD
REMAIN ABOVE THE TERMINAL/S ALTERNATE MINIMUMS. STILL EXPECT VFR
CONDITIONS AT KSAV WITH THESE CLOUDS REMAINING TO THE NORTH.
EXTENDED AVIATION OUTLOOK...THERE NO SIGNIFICANT ISSUES.
&&
.MARINE...
TODAY...THE MARINE AREA WILL SEE IMPROVING CONDITIONS THROUGH THE
DAY. SEAS STILL LOOK TO REMAIN ABOVE 6 FT ACROSS THE CHARLESTON
COUNTY COASTAL WATERS UNTIL LATE MORNING SO FLAGS WILL BE EXTENDED
BY A FEW HOURS WITH SEAS 2-4 FT OVER THE REMAINING NEARSHORE LEGS.
SEAS OF 6-8 FT ARE FORECAST TO REMAIN OVER THE GEORGIA OFFSHORE
WATERS THROUGH THE AFTERNOON SO A SMALL CRAFT ADVISORY WILL REMAIN
IN FORCE THERE.
TONIGHT...SHOULD SEE A BIT OF AN INCREASE IN WINDS OVERNIGHT IN
RESPONSE TO SHORTWAVE ENERGY APPROACHING FROM THE WEST. SPEEDS
SHOULD BE NO HIGHER 15-20 KT OVER THE OFFSHORE WATERS WITH 10-15
KT CLOSER TO THE COAST. SEAS WILL RANGE FROM 2-4 FT NEARSHORE
WATERS TO 5-7 FT OFFSHORE WATERS. A SMALL CRAFT ADVISORY WILL
REMAIN IN EFFECT OVERNIGHT FOR THE GEORGIA OFFSHORE LEG.
WEDNESDAY THROUGH SATURDAY...WINDS AND SEAS WILL REMAIN ELEVATED
THROUGH MID WEEK...AS THE PRESSURE GRADIENT REMAINS ENHANCED
OVER THE WATERS BETWEEN BROAD HIGH PRESSURE INLAND AND A LOW
PRESSURE SYSTEM FARTHER OUT IN THE ATLANTIC. WINDS AND SEAS WILL
REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS FOR NEARSHORE
WATERS. HOWEVER A COMBINATION OF NORTH/NORTHEAST WINDS...LONG
PERIOD SWELLS AND COLD ADVECTION ASSOCIATED WITH BUILDING HIGH
PRESSURE FROM THE WEST WILL ALLOW SMALL CRAFT ADVISORY CONDITIONS
TO PERSIST OVER OUTER GEORGIA WATERS THROUGH MID WEEK AND POSSIBLY
THROUGH LATE WEEK. CONDITIONS WILL THEN SLOWLY IMPROVE OVER ALL
WATERS LATE WEEK...AS THE LOW PRESSURE SYSTEM SHIFTS FURTHER
OFFSHORE AND THE PRESSURE GRADIENT WEAKENS ACCORDINGLY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST SATURDAY FOR AMZ374.
SMALL CRAFT ADVISORY UNTIL 11 AM EST THIS MORNING FOR AMZ350.
&&
$$
ST/79
AREA FORECAST DISCUSSION
NWS DES MOINES IA
330 PM CST TUE NOV 20 2012
.SHORT TERM /TONIGHT/...
SFC HIGH CENTERED FROM SRN IA SOUTHWESTWARD TO SLIDE EAST SOUTHEAST
TONIGHT...WITH SOUTHERLY FLOW AND WAA KICKING IN ALOFT. MOSTLY CLEAR
SKIES EXPECTED TONIGHT WITH THE EXCEPTION OF THE FAR EAST...WHERE
LOW STRATUS/FOG THAT IS CURRENTLY ACROSS SOUTHEASTERN IOWA EXPECTED
TO BUILD BACK WEST/NORTHWARD THIS EVENING. THEREFORE LOW CLOUDS/FOG
POSSIBLE FROM WATERLOO TO MARSHALLTOWN TO OTTUMWA OVERNIGHT...BASED
ON THE HRRR OUTPUT FOR LOW CLOUDS. AS SFC RIDGE AXIS PUSHES THROUGH
THE AREA AND WAA/SOUTHERLY FLOW INCREASES EXPECT MIN TEMPS TO START
LEVELING OFF/POSSIBLY WARMING TOWARD SUNRISE.
.LONG TERM /TONIGHT THROUGH TUESDAY/...
HIGH PRESSURE WILL SHIFT OFF TO THE SOUTHEAST ON WEDNESDAY AS A
BROAD AREA OF HIGH PRESSURE MOVES INTO THE DAKOTAS. THIS WILL
INCREASE THE SOUTHERLY FLOW INTO IOWA AS THE THERMAL RIDGE LEANS
INTO THE STATE. THESE CONDITIONS ALONG WITH VERY DRY AIR WILL BE
CONDUCIVE TO GOOD WARMING. AN INVERSION NEAR 900 MB APPEARS TO BE A
LIMITING FACTOR FROM ACHIEVING RECORD HIGH TEMPERATURES IN THE LOWER
70S HOWEVER EVEN IF THE INVERSION HOLDS...SUPER ADIABATIC LAPSE NEAR
SURFACE SHOULD PUSH READINGS INTO THE MID TO UPPER 60S. THE THERMAL
RIDGE STRENGTHENS WEDNESDAY NIGHT WITH SOUTHERLY WINDS CONTINUING.
LOWS WILL BE WELL INTO THE 40S AT MOST LOCATIONS. THURSDAY WILL HAVE
A WARM START WITH A COLD FRONT EXPECTED TO PASS THROUGH CENTRAL IOWA
DURING THE AFTERNOON. AN SHORT WAVE WILL LIFT UP THROUGH THE
SOUTHWEST FLOW AHEAD OF THE BOUNDARY AND WILL BRING THE CHANCE FOR A
FEW SHOWERS OVER THE FAR SOUTHEAST. THE NMM AND ARW BASED MODELS ARE
FARTHER SOUTHEAST WITH THIS SYSTEM THOUGH THE ECMWF AND GFS AFFECT
IOWA MORE. GENERALLY ANY PRECIPITATION WILL BE LIGHT. THIS SYSTEM
COULD BRING AN INCREASE IN CLOUDS AND MAY LIMIT TEMPERATURES A BIT.
CENTRAL AND SOUTHEAST IOWA SHOULD REACH THE 60S BEFORE THE COLD
FRONT PASSES THROUGH. STRONGER COLD ADVECTION NEAR 850 MB WILL
ENHANCE MIXING BEHIND THE FRONTAL BOUNDARY WITH INCREASING
SUBSIDENCE AIDING MOMENTUM TRANSFER OF WINDS TO THE SURFACE. MIXED
LAYER WINDS OF 25 TO 35 KTS SHOULD PUSH SUSTAINED WINDS TO NEAR WIND
ADVISORY CRITERIA MAINLY OVER THE NORTH AND WEST.
ANOTHER SURGE OF COLD ADVECTION WILL DROP SOUTH THURSDAY NIGHT.
FRIDAY WILL BE BLUSTERY AND COLD WITH BREEZY NORTHWEST WINDS. HIGHS
WILL GENERALLY BE IN THE LOW TO MID 30S. HIGH PRESSURE MOVES ACROSS
FRIDAY NIGHT. CURRENTLY HAVE LOWS A FEW DEGREES ABOVE MOS GUIDANCE
FOR POTENTIAL MID TO HIGH LEVEL CLOUDS WITH INCREASING THETA-E
ADVECTION THROUGH THOSE LEVELS. MINOR MODERATION SATURDAY INTO
SUNDAY. A STRONGER COLD FRONT IS DUE TO ARRIVE MONDAY AND LEAD TO A
COLD START TO NEXT WEEK. THE EXTENDED WILL BE MOSTLY DRY WITH THE
POTENTIAL FOR VERY LIGHT RAIN OR SNOW EARLY NEXT WEEK.
&&
.AVIATION...20/18Z
MAINLY VFR CONDITIONS EXPECTED THROUGHOUT THE PERIOD...WITH THE
EXCEPTION OF AT KOTM...WHERE SOME LINGERING LOW CLOUDS/HAZE MAY KEEP
IT MVFR BRIEFLY THROUGH 19Z BEFORE ERODING/DISSIPATING. GOES-R
SATELLITE FORECAST PRODUCT ALSO SUGGESTING LOW CLOUDS/FOG OVER
MINNESOTA TO SPREAD SOUTHWARD LATE TONIGHT INDICATING POSSIBILITY OF
IFR/MVFR CONDITIONS INTO KMCW. FOR NOW SATELLITE FORECAST PRODUCT
SEEMS A BIT AGGRESSIVE COMPARED TO CURRENT SATELLITE TRENDS AND
MODELS SHOWING ABSENCE OF LOW LEVEL MOISTURE THUS HAVE KEPT THE
FORECAST VFR AT THIS TIME DUE TO UNCERTAINTY IN THE DEVELOPMENT OF
THE IFR/MVFR CONDITIONS.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...MJB
LONG TERM...DONAVON
AVIATION...MJB
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1110 AM CST TUE NOV 20 2012
.UPDATE...
HAVE UPDATED THE FORECAST TO REMOVE FOG WORDING AND TOUCH UP SKY
COVER GRIDS SOME AS LOW STRATUS CONTINUES TO DISSIPATE/ERODE OUT OF
THE EASTERN CWA. ALSO HAVE DROPPED HIGHS A BIT ACROSS THE
NORTH/EASTERN CWA WITH THE COOL START AND LINGERING LOW CLOUDS IN
SOME PLACES. WEAK WAA ALOFT...BUT NORTHERLY WINDS AND STRONGER PUSH
OF WARM AIR ALOFT NOT REALLY WORKING ITS WAY INTO THE CWA UNTIL LATE
THIS AFTERNOON. THEREFORE JUST NUDGED THEM DOWN A BIT IN SOME PLACES
NORTH/EAST.
.SHORT TERM /TODAY/...
WEAK COLD FRONT IS PUSHING INTO SOUTHEAST IOWA. MOISTURE AHEAD OF
THE FRONT...COMBINED WITH LIGHT WINDS AND CLEAR SKIES...HAS RESULTED
IN WIDESPREAD DENSE FOG. ADVISORY REMAINS IN EFFECT FOR THE EASTERN
PART OF THE CWA THROUGH 16Z. FOG WILL ERODE AWAY FROM THE
WEST...BUT ONLY SLOW PROGRESS IS EXPECTED. HRRR IS QUITE
AGGRESSIVE IN HOLDING ONTO THE FOG AND DO NOT EXPECTED IT TO LAST
INTO THE AFTERNOON AS IT IS INDICATING. A COOLER START THIS MORNING
THAN YESTERDAY WILL HELP KEEP TEMPS BELOW 60 ACROSS THE CWA TODAY.
IN ADDITION...LIGHT WINDS WILL LIMIT MIXING DEPTH AS WELL.
.LONG TERM /TONIGHT THROUGH MONDAY/...
RIDGE WILL BUILD IN BEHIND WEAK FRONTAL BOUNDARY FOR THE BEGINNING
OF THE EXTENDED. UNDER RIDGE WITH SURFACE HIGH PRESSURE AND STRONG
SOUTHERLY FLOW...TEMPERATURES WILL REMAIN WARM...WELL ABOVE NORMAL
FOR NOVEMBER. HAVE KEPT TEMPERATURES NEAR GOING FORECAST...WITH
WARMEST DAY WEDNESDAY AS WAA INCREASES AHEAD OF A FRONTAL
BOUNDARY...AND CONDITIONS LOOK RIGHT FOR GOOD MIXING. COULD SEE
TEMPERATURES POP A FEW DEGREES ABOVE GOING IN LOCATIONS FOR
WEDNESDAY IF MIXING IS MAXIMIZED AS 85MB TEMPS WILL BE NEAR 14C
ACROSS THE WEST.
A WEAK FRONTAL BOUNDARY WILL PUSH ACROSS THE AREA FOR
THURSDAY...WITH TEMPERATURES SLIGHTLY COOLER BEHIND THE BOUNDARY.
HAVE LEFT SLIGHT CHANCE POPS ACROSS THE SOUTH FOR THURSDAY AS
MOISTURE INCREASES. HOWEVER...DO NOT HAVE A LOT OF CONFIDENCE IN
THESE CHANCE POPS AS MOISTURE IS SOMEWHAT LACKING. GFS IS MUCH MORE
AGGRESSIVE WITH MOISTURE HEAD OF BOUNDARY...WITH NAM AND ECMWF MUCH
LESS SO. HOWEVER...WITH FORCING ASSOCIATED WITH BOUNDARY COULD SEE
SOME PRECIPITATION EVEN WITH LIMITED MOISTURE AND HAVE LEFT SLIGHT
CHANCE POPS GOING.
A MUCH STRONGER SYSTEM PUSHES THROUGH THURSDAY NIGHT...WITH A LARGE
COOL DOWN IN STORE FOR THE END OF THE WEEK AS TEMPERATURES RETURN
TO NEAR NORMAL. LOW PRESSURE SYSTEM WILL TRACK TO THE NORTH...AND
COULD SEE SOME WRAP AROUND MOISTURE BRING LIGHT PRECIPITATION TO
THE NORTH FRIDAY AND FRIDAY NIGHT...HOWEVER HAVE LEFT OUT ANY
MENTION OF PRECIPITATION ATTM AS BEST FORCING WILL REMAIN NORTH
INTO MINNESOTA.
THE END OF THE PERIOD BECOMES A BIT TRICKY AS MODELS BUILD IN A
WEAK RIDGE FOR THE WEEKEND...WITH TEMPERATURES AGAIN ABLE TO WARM
NICELY. HOWEVER...THERE IS LITTLE AGREEMENT WITH SYSTEM FOR LATE
IN THE WEEK. CURRENT MODEL TRENDS ARE TO HAVE A LOW PRESSURE
SYSTEM PUSH ACROSS CANADA...BREAKING DOWN WEAK RIDGING. FRONTAL
BOUNDARY ASSOCIATED WITH THIS LOW PRESSURES SYSTEM WILL ALLOW FOR
CHANCES FOR PRECIPITATION ACROSS THE CWA BY LATE MONDAY.
HOWEVER...THERE IS NOT GOOD AGREEMENT IN THE TIMING AND LOCATION
OF THIS SYSTEM AND DO NOT HAVE HIGH CONFIDENCE. THIS WILL NEED TO
BE WATCHED CLOSELY.
&&
.AVIATION...20/18Z
MAINLY VFR CONDITIONS EXPECTED THROUGHOUT THE PERIOD...WITH THE
EXCEPTION OF AT KOTM...WHERE SOME LINGERING LOW CLOUDS/HAZE MAY KEEP
IT MVFR BRIEFLY THROUGH 19Z BEFORE ERODING/DISSIPATING. GOES-R
SATELLITE FORECAST PRODUCT ALSO SUGGESTING LOW CLOUDS/FOG OVER
MINNESOTA TO SPREAD SOUTHWARD LATE TONIGHT INDICATING POSSIBILITY OF
IFR/MVFR CONDITIONS INTO KMCW. FOR NOW SATELLITE FORECAST PRODUCT
SEEMS A BIT AGGRESSIVE COMPARED TO CURRENT SATELLITE TRENDS AND
MODELS SHOWING ABSENCE OF LOW LEVEL MOISTURE THUS HAVE KEPT THE
FORECAST VFR AT THIS TIME DUE TO UNCERTAINTY IN THE DEVELOPMENT OF
THE IFR/MVFR CONDITIONS.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...MS NOV 12
LONG TERM...AWB
AVIATION...MJB
UPDATE...MJB
AREA FORECAST DISCUSSION...UPDATED
NWS DES MOINES IA
1005 AM CST TUE NOV 20 2012
.UPDATE...
HAVE UPDATED THE FORECAST TO REMOVE FOG WORDING AND TOUCH UP SKY
COVER GRIDS SOME AS LOW STRATUS CONTINUES TO DISSIPATE/ERODE OUT OF
THE EASTERN CWA. ALSO HAVE DROPPED HIGHS A BIT ACROSS THE
NORTH/EASTERN CWA WITH THE COOL START AND LINGERING LOW CLOUDS IN
SOME PLACES. WEAK WAA ALOFT...BUT NORTHERLY WINDS AND STRONGER PUSH
OF WARM AIR ALOFT NOT REALLY WORKING ITS WAY INTO THE CWA UNTIL LATE
THIS AFTERNOON. THEREFORE JUST NUDGED THEM DOWN A BIT IN SOME PLACES
NORTH/EAST.
.SHORT TERM /TODAY/...
WEAK COLD FRONT IS PUSHING INTO SOUTHEAST IOWA. MOISTURE AHEAD OF
THE FRONT...COMBINED WITH LIGHT WINDS AND CLEAR SKIES...HAS RESULTED
IN WIDESPREAD DENSE FOG. ADVISORY REMAINS IN EFFECT FOR THE EASTERN
PART OF THE CWA THROUGH 16Z. FOG WILL ERODE AWAY FROM THE
WEST...BUT ONLY SLOW PROGRESS IS EXPECTED. HRRR IS QUITE
AGGRESSIVE IN HOLDING ONTO THE FOG AND DO NOT EXPECTED IT TO LAST
INTO THE AFTERNOON AS IT IS INDICATING. A COOLER START THIS MORNING
THAN YESTERDAY WILL HELP KEEP TEMPS BELOW 60 ACROSS THE CWA TODAY.
IN ADDITION...LIGHT WINDS WILL LIMIT MIXING DEPTH AS WELL.
.LONG TERM /TONIGHT THROUGH MONDAY/...
RIDGE WILL BUILD IN BEHIND WEAK FRONTAL BOUNDARY FOR THE BEGINNING
OF THE EXTENDED. UNDER RIDGE WITH SURFACE HIGH PRESSURE AND STRONG
SOUTHERLY FLOW...TEMPERATURES WILL REMAIN WARM...WELL ABOVE NORMAL
FOR NOVEMBER. HAVE KEPT TEMPERATURES NEAR GOING FORECAST...WITH
WARMEST DAY WEDNESDAY AS WAA INCREASES AHEAD OF A FRONTAL
BOUNDARY...AND CONDITIONS LOOK RIGHT FOR GOOD MIXING. COULD SEE
TEMPERATURES POP A FEW DEGREES ABOVE GOING IN LOCATIONS FOR
WEDNESDAY IF MIXING IS MAXIMIZED AS 85MB TEMPS WILL BE NEAR 14C
ACROSS THE WEST.
A WEAK FRONTAL BOUNDARY WILL PUSH ACROSS THE AREA FOR
THURSDAY...WITH TEMPERATURES SLIGHTLY COOLER BEHIND THE BOUNDARY.
HAVE LEFT SLIGHT CHANCE POPS ACROSS THE SOUTH FOR THURSDAY AS
MOISTURE INCREASES. HOWEVER...DO NOT HAVE A LOT OF CONFIDENCE IN
THESE CHANCE POPS AS MOISTURE IS SOMEWHAT LACKING. GFS IS MUCH MORE
AGGRESSIVE WITH MOISTURE HEAD OF BOUNDARY...WITH NAM AND ECMWF MUCH
LESS SO. HOWEVER...WITH FORCING ASSOCIATED WITH BOUNDARY COULD SEE
SOME PRECIPITATION EVEN WITH LIMITED MOISTURE AND HAVE LEFT SLIGHT
CHANCE POPS GOING.
A MUCH STRONGER SYSTEM PUSHES THROUGH THURSDAY NIGHT...WITH A LARGE
COOL DOWN IN STORE FOR THE END OF THE WEEK AS TEMPERATURES RETURN
TO NEAR NORMAL. LOW PRESSURE SYSTEM WILL TRACK TO THE NORTH...AND
COULD SEE SOME WRAP AROUND MOISTURE BRING LIGHT PRECIPITATION TO
THE NORTH FRIDAY AND FRIDAY NIGHT...HOWEVER HAVE LEFT OUT ANY
MENTION OF PRECIPITATION ATTM AS BEST FORCING WILL REMAIN NORTH
INTO MINNESOTA.
THE END OF THE PERIOD BECOMES A BIT TRICKY AS MODELS BUILD IN A
WEAK RIDGE FOR THE WEEKEND...WITH TEMPERATURES AGAIN ABLE TO WARM
NICELY. HOWEVER...THERE IS LITTLE AGREEMENT WITH SYSTEM FOR LATE
IN THE WEEK. CURRENT MODEL TRENDS ARE TO HAVE A LOW PRESSURE
SYSTEM PUSH ACROSS CANADA...BREAKING DOWN WEAK RIDGING. FRONTAL
BOUNDARY ASSOCIATED WITH THIS LOW PRESSURES SYSTEM WILL ALLOW FOR
CHANCES FOR PRECIPITATION ACROSS THE CWA BY LATE MONDAY.
HOWEVER...THERE IS NOT GOOD AGREEMENT IN THE TIMING AND LOCATION
OF THIS SYSTEM AND DO NOT HAVE HIGH CONFIDENCE. THIS WILL NEED TO
BE WATCHED CLOSELY.
&&
.AVIATION...20/12Z
FOG OVER EASTERN IA WILL SLOWLY IMPROVE DURING THE MORNING AS SOME
MIXING TAKES PLACE BEHIND THE WEAK FRONTAL BOUNDARY. TIMING OF THE
FOG ON THE HRRR SEEMS TOO SLOW WITH AN EXTENSIVE AREA HOLDING WELL
PAST 18Z. GOES-R SIMULATED WRF FCST PRODUCT SEEMS TO HAVE THE BEST
HANDLE ON THE FOG TIMING AND FOLLOWED FAIRLY CLOSE WITH THE
CLEARING. LITTLE ACTION IN THE REST OF THE TAF WITH WEAK HIGH
PRESSURE RIDGE MOVING ACROSS THE STATE TODAY AND TONIGHT.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...MS NOV 12
LONG TERM...AWB
AVIATION...MS NOV 12
UPDATE...MJB
AREA FORECAST DISCUSSION
NWS DES MOINES IA
654 AM CST TUE NOV 20 2012
.SHORT TERM /TODAY/...
WEAK COLD FRONT IS PUSHING INTO SOUTHEAST IOWA. MOISTURE AHEAD OF
THE FRONT...COMBINED WITH LIGHT WINDS AND CLEAR SKIES...HAS RESULTED
IN WIDESPREAD DENSE FOG. ADVISORY REMAINS IN EFFECT FOR THE EASTERN
PART OF THE CWA THROUGH 16Z. FOG WILL ERODE AWAY FROM THE
WEST...BUT ONLY SLOW PROGRESS IS EXPECTED. HRRR IS QUITE
AGGRESSIVE IN HOLDING ONTO THE FOG AND DO NOT EXPECTED IT TO LAST
INTO THE AFTERNOON AS IT IS INDICATING. A COOLER START THIS MORNING
THAN YESTERDAY WILL HELP KEEP TEMPS BELOW 60 ACROSS THE CWA TODAY.
IN ADDITION...LIGHT WINDS WILL LIMIT MIXING DEPTH AS WELL.
.LONG TERM /TONIGHT THROUGH MONDAY/...
RIDGE WILL BUILD IN BEHIND WEAK FRONTAL BOUNDARY FOR THE BEGINNING
OF THE EXTENDED. UNDER RIDGE WITH SURFACE HIGH PRESSURE AND STRONG
SOUTHERLY FLOW...TEMPERATURES WILL REMAIN WARM...WELL ABOVE NORMAL
FOR NOVEMBER. HAVE KEPT TEMPERATURES NEAR GOING FORECAST...WITH
WARMEST DAY WEDNESDAY AS WAA INCREASES AHEAD OF A FRONTAL
BOUNDARY...AND CONDITIONS LOOK RIGHT FOR GOOD MIXING. COULD SEE
TEMPERATURES POP A FEW DEGREES ABOVE GOING IN LOCATIONS FOR
WEDNESDAY IF MIXING IS MAXIMIZED AS 85MB TEMPS WILL BE NEAR 14C
ACROSS THE WEST.
A WEAK FRONTAL BOUNDARY WILL PUSH ACROSS THE AREA FOR
THURSDAY...WITH TEMPERATURES SLIGHTLY COOLER BEHIND THE BOUNDARY.
HAVE LEFT SLIGHT CHANCE POPS ACROSS THE SOUTH FOR THURSDAY AS
MOISTURE INCREASES. HOWEVER...DO NOT HAVE A LOT OF CONFIDENCE IN
THESE CHANCE POPS AS MOISTURE IS SOMEWHAT LACKING. GFS IS MUCH MORE
AGGRESSIVE WITH MOISTURE HEAD OF BOUNDARY...WITH NAM AND ECMWF MUCH
LESS SO. HOWEVER...WITH FORCING ASSOCIATED WITH BOUNDARY COULD SEE
SOME PRECIPITATION EVEN WITH LIMITED MOISTURE AND HAVE LEFT SLIGHT
CHANCE POPS GOING.
A MUCH STRONGER SYSTEM PUSHES THROUGH THURSDAY NIGHT...WITH A LARGE
COOL DOWN IN STORE FOR THE END OF THE WEEK AS TEMPERATURES RETURN
TO NEAR NORMAL. LOW PRESSURE SYSTEM WILL TRACK TO THE NORTH...AND
COULD SEE SOME WRAP AROUND MOISTURE BRING LIGHT PRECIPITATION TO
THE NORTH FRIDAY AND FRIDAY NIGHT...HOWEVER HAVE LEFT OUT ANY
MENTION OF PRECIPITATION ATTM AS BEST FORCING WILL REMAIN NORTH
INTO MINNESOTA.
THE END OF THE PERIOD BECOMES A BIT TRICKY AS MODELS BUILD IN A
WEAK RIDGE FOR THE WEEKEND...WITH TEMPERATURES AGAIN ABLE TO WARM
NICELY. HOWEVER...THERE IS LITTLE AGREEMENT WITH SYSTEM FOR LATE
IN THE WEEK. CURRENT MODEL TRENDS ARE TO HAVE A LOW PRESSURE
SYSTEM PUSH ACROSS CANADA...BREAKING DOWN WEAK RIDGING. FRONTAL
BOUNDARY ASSOCIATED WITH THIS LOW PRESSURES SYSTEM WILL ALLOW FOR
CHANCES FOR PRECIPITATION ACROSS THE CWA BY LATE MONDAY.
HOWEVER...THERE IS NOT GOOD AGREEMENT IN THE TIMING AND LOCATION
OF THIS SYSTEM AND DO NOT HAVE HIGH CONFIDENCE. THIS WILL NEED TO
BE WATCHED CLOSELY.
&&
.AVIATION...20/12Z
FOG OVER EASTERN IA WILL SLOWLY IMPROVE DURING THE MORNING AS SOME
MIXING TAKES PLACE BEHIND THE WEAK FRONTAL BOUNDARY. TIMING OF THE
FOG ON THE HRRR SEEMS TOO SLOW WITH AN EXTENSIVE AREA HOLDING WELL
PAST 18Z. GOES-R SIMULATED WF FCST PRODUCT SEEMS TO HAVE THE BEST
HANDLE ON THE FOG TIMING AND FOLLOWED FAIRLY CLOSE WITH THE
CLEARING. LITTLE ACTION IN THE REST OF THE TAF WITH WEAK HIGH
PRESSURE RIDGE MOVING ACROSS THE STATE TODAY AND TONIGHT.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR BLACK HAWK-
BREMER-BUTLER-DAVIS-GRUNDY-JASPER-MAHASKA-MARSHALL-POWESHIEK-
TAMA-WAPELLO.
&&
$$
SHORT TERM...MS NOV 12
LONG TERM...AWB
AVIATION...MS NOV 12
AREA FORECAST DISCUSSION
NWS DES MOINES IA
339 AM CST TUE NOV 20 2012
.SHORT TERM /TODAY/...
WEAK COLD FRONT IS PUSHING INTO SOUTHEAST IOWA. MOISTURE AHEAD OF
THE FRONT...COMBINED WITH LIGHT WINDS AND CLEAR SKIES...HAS RESULTED
IN WIDESPREAD DENSE FOG. ADVISORY REMAINS IN EFFECT FOR THE EASTERN
PART OF THE CWA THROUGH 16Z. FOG WILL ERODE AWAY FROM THE
WEST...BUT ONLY SLOW PROGRESS IS EXPECTED. HRRR IS QUITE
AGGRESSIVE IN HOLDING ONTO THE FOG AND DO NOT EXPECTED IT TO LAST
INTO THE AFTERNOON AS IT IS INDICATING. A COOLER START THIS MORNING
THAN YESTERDAY WILL HELP KEEP TEMPS BELOW 60 ACROSS THE CWA TODAY.
IN ADDITION...LIGHT WINDS WILL LIMIT MIXING DEPTH AS WELL.
.LONG TERM /TONIGHT THROUGH MONDAY/...
RIDGE WILL BUILD IN BEHIND WEAK FRONTAL BOUNDARY FOR THE BEGINNING
OF THE EXTENDED. UNDER RIDGE WITH SURFACE HIGH PRESSURE AND STRONG
SOUTHERLY FLOW...TEMPERATURES WILL REMAIN WARM...WELL ABOVE NORMAL
FOR NOVEMBER. HAVE KEPT TEMPERATURES NEAR GOING FORECAST...WITH
WARMEST DAY WEDNESDAY AS WAA INCREASES AHEAD OF A FRONTAL
BOUNDARY...AND CONDITIONS LOOK RIGHT FOR GOOD MIXING. COULD SEE
TEMPERATURES POP A FEW DEGREES ABOVE GOING IN LOCATIONS FOR
WEDNESDAY IF MIXING IS MAXIMIZED AS 85MB TEMPS WILL BE NEAR 14C
ACROSS THE WEST.
A WEAK FRONTAL BOUNDARY WILL PUSH ACROSS THE AREA FOR
THURSDAY...WITH TEMPERATURES SLIGHTLY COOLER BEHIND THE BOUNDARY.
HAVE LEFT SLIGHT CHANCE POPS ACROSS THE SOUTH FOR THURSDAY AS
MOISTURE INCREASES. HOWEVER...DO NOT HAVE A LOT OF CONFIDENCE IN
THESE CHANCE POPS AS MOISTURE IS SOMEWHAT LACKING. GFS IS MUCH MORE
AGGRESSIVE WITH MOISTURE HEAD OF BOUNDARY...WITH NAM AND ECMWF MUCH
LESS SO. HOWEVER...WITH FORCING ASSOCIATED WITH BOUNDARY COULD SEE
SOME PRECIPITATION EVEN WITH LIMITED MOISTURE AND HAVE LEFT SLIGHT
CHANCE POPS GOING.
A MUCH STRONGER SYSTEM PUSHES THROUGH THURSDAY NIGHT...WITH A LARGE
COOL DOWN IN STORE FOR THE END OF THE WEEK AS TEMPERATURES RETURN
TO NEAR NORMAL. LOW PRESSURE SYSTEM WILL TRACK TO THE NORTH...AND
COULD SEE SOME WRAP AROUND MOISTURE BRING LIGHT PRECIPITATION TO
THE NORTH FRIDAY AND FRIDAY NIGHT...HOWEVER HAVE LEFT OUT ANY
MENTION OF PRECIPITATION ATTM AS BEST FORCING WILL REMAIN NORTH
INTO MINNESOTA.
THE END OF THE PERIOD BECOMES A BIT TRICKY AS MODELS BUILD IN A
WEAK RIDGE FOR THE WEEKEND...WITH TEMPERATURES AGAIN ABLE TO WARM
NICELY. HOWEVER...THERE IS LITTLE AGREEMENT WITH SYSTEM FOR LATE
IN THE WEEK. CURRENT MODEL TRENDS ARE TO HAVE A LOW PRESSURE
SYSTEM PUSH ACROSS CANADA...BREAKING DOWN WEAK RIDGING. FRONTAL
BOUNDARY ASSOCIATED WITH THIS LOW PRESSURES SYSTEM WILL ALLOW FOR
CHANCES FOR PRECIPITATION ACROSS THE CWA BY LATE MONDAY.
HOWEVER...THERE IS NOT GOOD AGREEMENT IN THE TIMING AND LOCATION
OF THIS SYSTEM AND DO NOT HAVE HIGH CONFIDENCE. THIS WILL NEED TO
BE WATCHED CLOSELY.
&&
.AVIATION...20/06Z
HAVE UPDATED TAFS TO INCLUDE LOWER VISIBILITY ACROSS THE NORTH AND
EAST OVERNIGHT. SOME QUESTION AS TO HOW LONG LOW VISIBILITY WILL
LAST AND IF VARIABLE CONDITIONS WILL DEVELOP WITH THE VSBY AS
TEMPS WARM AND FALL DUE TO FOG FORMATION. WEAK BOUNDARY EXPECTED
TO ARRIVE OVER EAST BY 12Z AS EXPECTED...AND THIS WILL FOCUS THE
FOG IN THIS LOCATION. OVER THE REMAINDER OF THE SITES NOT MUCH
EXPECTED AT KDSM AND KFOD...BUT KALO...KOTM...AND KMCW LIFR TO IFR
VSBY AND CIGS CAN BE EXPECTED AT TIMES UNTIL THE FOG LIFTS AFT
14-15Z. THE REMAINDER OF THE FORECAST WILL BECOME BENIGN WITH VFR
CONDITIONS RETURNING.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR BLACK HAWK-
BREMER-BUTLER-DAVIS-GRUNDY-JASPER-MAHASKA-MARSHALL-POWESHIEK-
TAMA-WAPELLO.
&&
$$
SHORT TERM...MS NOV 12
LONG TERM...AWB
AVIATION...REV
AREA FORECAST DISCUSSION...CORRECTED
NWS QUAD CITIES IA IL
1147 PM CST MON NOV 19 2012
.AVIATION...
SKIES HAVE CLEARED OVER MUCH OF THE AREA THIS EVENING...BUT VFR
CIGS BASED AROUND 35HND FEET REMAIN EAST OF A LINE FROM JUST WEST
OF KDBQ TO JUST WEST OF KMLI THROUGH KGBG. MODEL RH FIELDS SUGGEST
THESE CLOUDS WILL NOT MOVE MUCH FURTHER EAST AND THE LATEST
SATELLITE IMAGERY SHOWS THE EASTWARD PROGRESS SLOWING SIGNIFICANTLY.
TO THE WEST CLEAR SKIES AND LIGHT WINDS NEAR A WEAK FRONT JUST
MOVING INTO EASTERN IOWA HAVE CREATED FAVORABLE CONDITIONS FOR
FOG. DENSE FOG WITH LIFR CIGS AND VSBYS LOOK REASONABLE AT KCID
AND PROBABLY KBRL EARLY THIS MORNING. THE CLOUD COVER NEAR THE
MISSISSIPPI RIVER SHOULD KEEP THE DENSE FOG OUT OF KDBQ AND KMLI.
ONCE THE FRONT MOVES THROUGH THE AREA LOCATIONS THAT HAVE THE LIFR
CONDITIONS SHOULD SLOWLY IMPROVE WITH VFR CONDITIONS EXPECTED AT
ALL SITES AROUND 18Z TUESDAY.
DLF
&&
PREV DISCUSSION... /ISSUED 315 PM CST MON NOV 19 2012/
SYNOPSIS...
12Z UA ANALYSIS HAS SEVERAL WEAK TROFS FROM THE WESTERN GREAT LAKES
INTO THE ROCKIES. AT 850MB A MOISTURE PLUME EXTENDED FROM THE BAY OF
CAMPECHE UP INTO CENTRAL IOWA. RADAR TRENDS THROUGH EARLY AFTERNOON
SHOW A CONTINUED DECREASE OF THE PRECIPITATION AS THE OVERALL FORCING
WEAKENS. AT THE SAME TIME...LOW CLOUDS HAD DEVELOPED ON THE EASTERN
EDGE OF THE CLEARING AND WERE NOW OVER THE MID MISSISSIPPI VALLEY.
18Z SFC ANALYSIS HAS A VERY WEAK LOW ALONG THE OK/TX BORDER EAST OF
KAMA WITH A TROF EXTENDING NORTH FROM THE LOW INTO NORTHERN
MINNESOTA. A WEAK COLD FRONT RAN FROM NORTHWEST MINNESOTA INTO SOUTH
DAKOTA. DEW POINTS WERE IN THE 40S AND 50S IN A BROAD MOISTURE PLUME
FROM TEXAS INTO IOWA WITH 30S ACROSS THE REMAINDER OF THE MIDWEST
AND PLAINS.
SHORT TERM...TONIGHT AND TUESDAY...
THE ONLY EXPLANATION FOR THE RAPID DEVELOPMENT OF THE LOW CLOUDS
ACROSS THE CWFA SINCE LATE MORNING IS CONVERGENT FLOW AHEAD OF THE
TROF. THIS CONVERGENCE CONTINUES THIS AFTERNOON SO THE CLOUDS ARE
EXPECTED TO REMAIN ACROSS THE AREA. RADAR TRENDS SUGGEST THE
POTENTIAL FOR SOME SPRINKLES/VERY LIGHT SHRA TO CONTINUE INTO THE
LATE AFTERNOON HOURS AS WELL IN THE EASTERN CWFA.
GOING ON THE ASSUMPTION THAT THE RAP TRENDS ARE CORRECT...THE
OVERALL CONVERGENCE IS PROGGED TO WEAKEN THIS EVENING WHICH SHOULD
ALLOW THE CLOUDS TO PARTIALLY BREAK UP IN THE WESTERN CWFA. IN THE
EASTERN CWFA LINGERING SPRINKLES ARE POSSIBLE EARLY THIS EVENING.
THE RAP TRENDS AFTER MIDNIGHT ARE DISTURBING. THE CONVERGENT FLOW IS
PROGGED TO INCREASE AGAIN AND THE RAP IS INDICATING THAT A WEAK LOW
WILL MOVE ALONG THE TROF INTO THE CWFA PRIOR TO SUNRISE. WITH
PLENTIFUL LOW LEVEL MOISTURE IN PLACE THE CLOUDS ARE EXPECTED TO
RE-DEVELOP OR FOG/STRATUS WILL DEVELOP IN THE CLEAR AREAS. THUS WILL
ADD AREAS OF FOG IN THE WESTERN CWFA AND PATCHY FOG EAST WHERE THE
CLOUDS ARE EXPECTED TO LINGER LONGER.
I CANNOT RULE OUT THE POSSIBILITY OF A HEADLINE FOR THE FOG LATE
TONIGHT INTO TUESDAY MORNING. HOW THE CLOUDS AND POTENTIAL FOG
DEVELOP/EVOLVE LATE TONIGHT WILL BE THE KEY. IF ONE HAD TO ASSIGN A
PROBABILITY IT IS CURRENTLY 1 IN 5 OR 1 IN 4 REGARDING A HEADLINE.
ASSUMING THAT LOW CLOUDS/FOG DEVELOP LATE TONIGHT THEY WILL CONTINUE
INTO TUESDAY MORNING. THE FOG SHOULD LIFT BY LATE MORNING WITH THE
CLOUDS EXPECTED TO CLEAR OUT DURING THE AFTERNOON. THE RATE OF
CLEARING ON TUESDAY IS A CONCERN GIVEN THE WEAK SUN. IT IS ENTIRELY
POSSIBLE THAT THE CLOUDS MAY NOT CLEAR OUT UNTIL CLOSE TO SUNSET
TUESDAY. IF THAT OCCURS...THE CURRENT MAX TEMPERATURES FOR TUESDAY
ARE TOO WARM. ..08..
LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY...
TUESDAY NIGHT AND WEDNESDAY...BOTH SFC AND UPPER RIDGING STILL ON
TRACK TO GET PRESSED ACRS THE REGION THIS PERIOD AS WELL AS
UNSEASONABLY MILD TEMPS. LIGHT WINDS AND CLEAR OUT OF CLOUDS WILL
MAKE FOR A COOLER NIGHT TUE NIGHT WITH LOWS WELL DOWN IN THE 30S.
DEPENDING ON TUE AFTERNOON CLOUD CLEAR OUT...THE LATER THE CLEARING
TREND AND THUS REDUCING THE SFC MIX OUT DRYING...TUE NIGHT MAY BE AN
IDEAL RADIATIONAL FOG SET UP ESPECIALLY ALONG AND EAST OF THE MS RVR.
WILL HOLD OFF MENTION FOR NOW BUT FOLLOWING SHIFTS WILL HAVE TO
ASSESS THIS POTENTIAL. AS FOR WED...TEMPORARY OMEGA BLOCK OVER
STRENGTHENING WARMING LLVL RETURN FLOW STILL APPEAR ON TAP. EXTENT OF
AVERAGED LLVL THERMAL DRAW BY THE MAJORITY OF THE NEW 12Z RUN MODELS
AND MIXING UP INTO BASE ON BUILDING WARM WEDGE ALOFT SUPPORTS
WIDESPREAD HIGHS IN THE UPPER 50S IN THE FAR NORTHEAST...TO THE MID
60S IN THE SOUTHWEST. UNSEASONABLY MILD WED NIGHT AND IF SOUTHERLY
SFC WINDS CAN MAINTAIN AT 5-10 KTS...MANY AREAL TEMPS WILL BE HELD UP
FROM DIPPING BELOW THE MID-UPPER 40S. BUT MAY PLAY IT COOLER IN CASE
OF ANY SFC WIND DECREASE EVEN IF TEMPORARY.
THURSDAY AND FRIDAY... INCOMING PACIFIC NW WAVE ENERGY/DEVELOPING
CYCLONE ACRS THE NORTHERN PLAINS AND ASSOCIATED SFC FRONT PROJECTED
BY LATER RUNS TO SWEEP THROUGH THE DVN CWA THU EVENING. ACTUAL FROPA
OCCURRING ACRS THE MS RVR FROM THE WEST PROGGED BY ENSEMBLE MEAN NOW
LOOKS TO OCCUR AROUND OR JUST AFTER 00Z FRI...THUS THE BULK OF THU
THE DVN CWA TO BE IN BREEZY PRE-FRONTAL WARM SECTOR. STOUT INVERSION
ALOFT AND INCREASE IN LOW-TO-MID LEVEL MOISTURE/CLOUDS COULD BE THE
LIMITING FACTOR AND PREVENT A RECORD MILD THANKSGIVING. IF IT WERE
NOT FOR THOSE FACTORS...SOME AREAS WOULD HIT 70 OR HIGHER. BUT
WILL WITH A MORE CONSERVATIVE LOW TO MID 60S. STRENGTH OF LLVL FRONT
ITSELF AND MID-UPPER LOW ROLLING ACRS THE UPPER MS RVR VALLEY SHOULD
BE ENOUGH TO DEVELOP SOME SHOWERS JUST AHEAD OF THE FRONT THU
AFTERNOON AND EVENING EVEN TAKING INTO ACCOUNT SOMEWHAT LIMITED
MOISTURE RETURN INTO THE FROPA PROCESS. BUT IF LATER RUNS TREND
WETTER...SOME MODERATE SHOWERS AN POSSIBLY EVEN A THUNDERSTORM MAY BE
POSSIBLE THU AFTERNOON/EVENING. IT ALL DEPENDS ON ANY BUILD UP OF
INSTABILITY IF IT CAN AS THU PROGRESSES. DEPENDING ON THE FRONTAL
TIMING...LATE NIGHT SWITCH OVER TO LLVL COLD CONVEYOR COULD PLUNGE
MUCH OF THE NORTHWEST HALF OF THE LOCAL FCST AREA INTO THE LOW TO MID
30S. FRIDAY STILL ON TRACK TO BE A MUCH COLDER BLUSTERY DAY IN
SUBSIDING DRY SLOT OFF GRT LKS CYCLONE...WITH HIGHS HAVING TROUBLE
GETTING OUT OF THE UPPER 30S TO LOWER 40S AS NORTHWEST WINDS GUST
OVER 30 MPH. WRAP AROUND SNOW FLURRIES/SHOWERS MAY NOT BE ALL THAT
FAR AWAY FROM THE LOCAL AREA ACRS SOUTHERN WI. IF SFC WINDS DECOUPLE
UNDER CLEAR SKIES FRI NIGHT...LOWS COULD DIP INTO THE LOWER 20S TO
EVEN UPPER TEENS IN SOME LOCATIONS BY EARLY SAT MORNING.
SATURDAY THROUGH NEXT MONDAY...LATEST RUN OF THE MEDIUM RANGE
SOLUTIONS AND ENSEMBLES SUGGEST A QUICK RETURN TO PROGRESSIVE
WESTERLIES/ FLATTENED FLOW PATTERN ACRS MUCH OF THE CONUS...THUS DRY
AND THERMALLY MODERATING WX INTO SUNDAY AND SUNDAY NIGHT. HIGHS BY
SUNDAY BACK INTO THE MID 40S TO NEAR 50 WITH SOME RETURN FLOW MIXING
AND INSOLATION. AS FOR EARLY TO MID NEXT WEEK...NORTHERN HEMISPHERIC
TELECONNECTIONS SUGGEST ENOUGH WAVE ENERGY/UPPER JET INFLUX DIGGING
INTO THE WEST FOR AN EVENTUAL L/W TROF COMPLEX ACRS THE SOUTHWESTERN
ROCKIES AND GRT BSN. MANY COMPLEX PHASING ISSUES TO BE RESOLVED THAT
FAR OUT...BUT THE GENERAL SIGNAL OF A LOADED SOUTHWEST FLOW PATTERN
ACRS THE WESTERN TO MID CONUS WITH COLD AIR TRYING TO DUMP DOWN THE
PLAINS AND UPPER MIDWEST WHILE A WARM MOIST CONVEYOR STREAMS UP
NORTHWARD TO THE LEE OF THE L/W TROF...COULD MAKE FOR A VERY
INTERESTING MID TO LATE WEEK PERIOD. STAY TUNED. ..12..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
510 PM CST WED NOV 21 2012
...UPDATE TO AVIATION...
.SYNOPSIS...
ISSUED AT 343 PM CST WED NOV 21 2012
THE PERSISTENT LONGWAVE TROUGH CONTINUED TO BE THE PREVAILING
METEOROLOGICAL FEATURE ACROSS THE PACIFIC-NORTH AMERICA SECTOR. ON
THE SYNOPTIC SCALE, A FAIRLY INTENSE STORM SYSTEM WAS MOVING INLAND
WASHINGTON/SOUTHERN BRITISH COLUMBIA. BY WEDNESDAY AFTERNOON, THE
PRIMARY CIRCULATION CENTER WAS MOVING ACROSS THE CANADIAN ROCKIES.
THE STRONG CROSS-MOUNTAIN FLOW WAS KEEPING MSLP FAIRLY LOW ACROSS
ALL OF THE NORTHERN HIGH PLAINS (1001MB SURFACE LOW NEAR ALZADA,
MONTANA AT 21Z). A SUBSTANTIAL WARM SECTOR ENCOMPASSED MUCH OF THE
GREAT PLAINS FROM TEXAS TO SOUTH DAKOTA WITH WIDESPREAD 70S OBSERVED
THIS AFTERNOON. MSLP GRADIENT WAS STRONGEST FROM WESTERN IOWA INTO
SOUTHWESTERN KANSAS WHERE WINDS RANGED FROM 22 TO 27 KNOTS SUSTAINED
DURING THE AFTERNOON HOURS. OF NOTE AS WELL (WHICH WILL PLAY INTO
TONIGHTS FORECAST), WAS A SUBTROPICAL DISTURBANCE FROM NEW MEXICO TO
SOUTHWEST TEXAS WHICH YIELDED QUITE A BIT OF MID AND HIGH LEVEL
CLOUD COVER AND EVEN A FEW LIGHTNING STRIKES FROM SHOWERS AND
ISOLATED THUNDERSTORMS.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 343 PM CST WED NOV 21 2012
FOR THE TIME PERIOD TONIGHT AND TOMORROW, THE GREATEST CHALLENGE IN
THE FORECAST WILL BE LOWS TONIGHT AND HOW MUCH CLOUD COVER AND WIND
WILL INFLUENCE OVERNIGHT TEMPERATURES. THE PREVIOUS FORECAST
ALREADY HAD A FAIRLY TIGHT GRADIENT IN LOW TEMPERATURES TONIGHT
(FROM 33F ACROSS FAR WEST CENTRAL KANSAS TO AROUND 51F ACROSS FAR
SOUTH CENTRAL KANSAS). THESE LOOK GOOD FOR THE MOST PART, BUT THE
LATEST RAP AND NAM12 MODELS SUGGEST TEMPERATURES WILL NOT GET MUCH
BELOW 60F SOUTHEAST OF A GREAT BEND TO ASHLAND LINE, AND GIVEN THE
SEMI OPAQUE SKY COVER FROM 300-500MB CLOUD (FROM THE SUBTROPICAL
SHORTWAVE TROUGH) AND THE SOUTHWEST WINDS CONTINUING 12 TO 16 KNOTS
IN THESE AREAS, REALLY CANNOT ARGUE AGAINST THESE WARM TEMPERATURES
TONIGHT. AS A RESULT, I HAVE BUMPED UP MIN TEMPS ABOUT 2 TO 4
DEGREES AND MOVED THE GRADIENT WESTWARD ABOUT 30 MILES OR SO
(EFFECTIVELY WARMING UP DODGE CITY LOW QUITE A BIT).
THE FORECAST FOR THANKSGIVING DAY WILL BE A LITTLE LESS COMPLICATED
AS MID-HIGH LEVEL CLOUD COVER WILL BE MOVING EAST OF THE AREA WITH
SURFACE WINDS BECOMING NORTHWESTERLY. WHILE COLD ADVECTION WILL
EXIST BEHIND THE FRONT, THE AIRMASS WILL BE MODIFIED BY DOWNSLOPE
AND INSOLATION WILL ALSO COUNTER THE COLD ADVECTION. HIGHS WILL
STILL BE ABOVE AVERAGE FOR THE DATE WITH TEMPERATURES WARMING INTO
THE 60S (LOWER 70S SOUTH CENTRAL KS). WITH THE INITIAL ISALLOBARIC
WIND SURGE/PRESSURE RISE WITH THE PASSAGE OF THE FRONT, WIND SPEEDS
WILL BE 22 TO 26 KNOTS MUCH LIKE TODAY, BUT THESE SPEEDS SHOULD ONLY
OCCUR DURING ABOUT A 3 OR 4 HOUR PERIOD BEFORE WINDS GRADUALLY
DECREASE BACK DOWN TO THE 18 TO 22 KT RANGE LATE IN THE DAY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 248 PM CST WED NOV 21 2012
BY THE BEGINNING OF THE EXTENDED PERIOD ON THURSDAY NIGHT, A STRONG
UPPER LEVEL SHORTWAVE TROUGH WILL BE MOVING OUT OF THE NORTHERN
PLAINS INTO THE MIDWESTERN STATES AND GREAT LAKES REGION. A COLD
FRONT WILL BE LOCATED OVER SOUTHEAST KANSAS INTO WEST TEXAS. HIGH
PRESSURE WILL BE BUILDING INTO WESTERN KANSAS BEHIND THE FRONT
THURSDAY NIGHT THROUGH FRIDAY. THE 12Z MODEL TEMPERATURE FORECASTS
ARE COMING IN COOLER THAN PREVIOUS RUNS WHICH SEEMS REASONABLE GIVEN
THE ONGOING COLD AIR ADVECTION.
INTO THIS WEEKEND, FLAT UPPER LEVEL RIDGING WILL SPREAD EAST ACROSS
THE WESTERN AND CENTRAL PART OF THE COUNTRY. ANOTHER SHORTWAVE
TROUGH WILL MOVE INTO THE PACIFIC NORTHWEST ON SATURDAY BEHIND THE
RIDGE AND THIS FEATURE WILL BE DIGGING SOME AS IT MOVES INTO THE
CENTRAL HIGH PLAINS BY MONDAY NIGHT. THROUGH THIS WEEKEND THE DRY
FORECAST WILL CONTINUE WITH TEMPERATURES WILL MODERATE BACK INTO THE
60S. LEE SIDE TROUGHING WILL DEVELOP ON SATURDAY. THIS WILL DEVELOP
INTO A LOW PRESSURE AREA THAT MOVES INTO THE OKLAHOMA AND TEXAS
PANHANDLES BY SUNDAY EVENING AS THE NEXT UPPER TROUGH APPROACHES.
THIS WILL BRING A SWITCH IN THE SURFACE WINDS BACK AROUND TO THE
EAST TO NORTHEAST ON SUNDAY. THIS WAVE WILL MOVE OUT ACROSS THE
CENTRAL AND NORTHERN PLAINS MONDAY NIGHT. THERE DOES NOT APPEAR TO
BE SUFFICIENT MOISTURE AVAILABLE FOR THIS SYSTEM TO WORK WITH. THE
BEST CHANCES FOR MEASURABLE PRECIPITATION WILL BE ALONG THE EASTERN
SLOPES OF THE ROCKIES AND OVER EASTERN KANSAS INTO THE MID
MISSISSIPPI VALLEY. HIGH TEMPERATURES WILL DROP BACK INTO THE 40S ON
MONDAY AND TUESDAY.
THE REMAINDER OF THE EXTENDED PERIOD WILL SEE AN UPPER LEVEL RIDGE
BUILDING OVER THE CENTRAL PART OF THE COUNTRY. THIS WILL RESULT IN
TEMPERATURES MODERATING BACK INTO THE 60S LATER NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 505 PM CST WED NOV 21 2012
VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES THROUGH EARLY
THURSDAY AFTERNOON. AS FOR WINDS, A LEE SIDE TROUGH OF LOW
PRESSURE IN EXTREME EASTERN COLORADO WILL BEGIN EDGING EAST
INTO WESTERN KANSAS THIS EVENING. AS A RESULT, SOUTHERLY WINDS
OF 15 TO 25KT EARLY THIS EVENING WILL BECOME MORE SOUTHWESTERLY
WHILE DECREASING 5 TO 15KT OVERNIGHT. A COLD FRONT IS THEN
EXPECTED TO PUSH SOUTHEAST ACROSS WESTERN KANSAS EARLY THURSDAY
MORNING TURNING WINDS NORTHERLY 25 TO 35KT BY MID DAY THURSDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 53 66 24 53 / 0 0 0 0
GCK 36 64 22 53 / 0 0 0 0
EHA 39 65 23 53 / 0 0 0 0
LBL 48 67 24 55 / 0 0 0 0
HYS 43 63 21 51 / 0 0 0 0
P28 56 72 28 53 / 10 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...UMSCHEID
LONG TERM...GERARD
AVIATION...JJOHNSON
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1040 AM MST TUE NOV 20 2012
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 205 AM MST TUE NOV 20 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW A RIDGE EXTENDING NORTH
ACROSS THE CENTRAL AND HIGH PLAINS WITH A LARGE TROUGH JUST OFF THE
PACIFIC NORTHWEST COAST.
TODAY-WEDNESDAY...WITH SHORTWAVE RIDGE IN PLACE TODAY AND SW FLOW
ALOFT AND LARGE SCALE SUBSIDENCE ON WEDNESDAY DRY CONDITIONS ARE
EXPECTED. WITH WAA ON EASTERN EXTENT OF LEE TROUGH STRENGTHENING THE
NEXT FEW DAYS...WE SHOULD SEE TEMPERATURES IN THE 70S...WITH MID TO
UPPER 70S POSSIBLE ON WED. BREEZY CONDITIONS WILL ALSO DEVELOP OVER
PARTS OF THE AREA WITH GUSTS 20-30 MPH OVER PARTS OF THE AREA THE
NEXT FEW AFTERNOONS. SEE FIRE WEATHER SECTION REGARDING POSSIBLE RED
FLAG CONDITIONS THE NEXT FEW DAYS.
THURSDAY-THURSDAY NIGHT...A STRONG TROUGH WILL MOVE ALONG THE CANADA
US BORDER ON WED NIGHT AND THURSDAY...WITH A WEAKER LESS AMPLIFIED
SHORTWAVE MOVING ACROSS THE SOUTHERN STREAM. THE NORTHERN TROUGH
WILL KICK A COLD FRONT SOUTH OVER THE CWA THURSDAY...WITH WINDY
CONDITIONS EXPECTED THROUGH WED AFTERNOON. WE COULD SEE WIND ADVISORY
CRITERIA MET WITH BL WINDS 27-29KT AND H85 WINDS AROUND 40KT. ITS
STILL TOO EARLY FOR AN NPW...HOWEVER I DID INCREASE WINDS TO REFLECT
CURRENT THINKING. BEYOND FORCING IMMEDIATELY ALONG FRONT THE BEST
LARGE SCALE ASCENT IS WELL NORTH AND SOUTHEAST. THE AIR MASS ALSO
REMAINS VERY DRY ACROSS CWA...SO IM NOT ANTICIPATING ANY PRECIP.
WITH FROPA DURING THE DAY HIGH TEMPS THU ARE TRICKY...HOWEVER THEY
STILL SHOULD BE ABOVE NORMAL WITH A GRADIENT OF UPPER 50S IN THE
NORTH TO MID/UPPER 60S IN THE SOUTH. NEAR TO BELOW NORMAL LOW TEMPS
ARE EXPECTED THU NIGHT BEHIND THE FRONT WITH VALUES RANGING FROM THE
UPPER TEENS TO MID 20S.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 205 AM MST TUE NOV 20 2012
AT LEAST EARLY ON MODELS ARE CONSISTENT WITH THE PREVIOUS
FORECAST. COOLEST DAY WILL BE ON FRIDAY WITH MODERATION FOR
SATURDAY. THEN CHANGES AND INCONSISTENCIES BEGIN AFTER THAT. NEWER
MODEL DATA...ESPECIALLY THE ECMWF...IS NOW MORE PROGRESSIVE AND
NOT AS STRONG WITH INCOMING UPPER TROUGH AT THE BEGINNING OF NEXT
WEEK. GFS IS MUCH FASTER AND OLDER CANADIAN WAS MORE IN LINE WITH
THE ECMWF. IN ADDITION THE MODEL DATA BRINGS IN NOT JUST ONE
SHORTWAVE BUT A SERIES OF SHORTWAVE TROUGHS IN THE SUNDAY NIGHT
THROUGH MONDAY NIGHT TIME PERIOD.
THIS NEWER DATA IS FITTING THE PATTERN WE HAVE BEEN SEEING THIS
SEASON AND IN FACT THIS YEAR. THE TROUGH DOES NOT COME THROUGH IN
ONE NICE ORGANIZED SYSTEM BUT IN A SERIES OF SHORTWAVE TROUGHS.
ENSEMBLE DATA SUPPORTS THE MORE PROGRESSIVE AND MULTIPLE SHORTWAVE
SOLUTION AS WELL. THESE MULTIPLE SHORTWAVES HAVE TENDED TO SCOUR OUT
THE DEEPER MOISTURE THAT THE MODELS THINK IS THERE. BELIEVE THAT
THIS IS THE CASE HERE AS WELL. PLUS THE FRONT COMES THROUGH RATHER
EARLY AND BY SUNDAY NIGHT IS A GREAT DISTANCE SOUTH OF THE AREA. NO
SIGNIFICANT JET LIFT LOOKS TO BE INVOLVED AS WELL. AS A RESULT OF
ALL THIS AND COLLABORATION...KEPT THE SMALL AREAS OF SLIGHT CHANCE
POPS SUNDAY NIGHT AND MONDAY THE INIT GAVE ME AND REDUCED THE CHANCE
POPS FOR MONDAY NIGHT DOWN TO SLIGHT CHANCE.
BIG DIFFERENCES SHOWING UP IN THE LOW LEVEL THERMAL FIELD BEGINNING
ON SUNDAY. THE ECMWF WAS NOT AS COLD AS THE FRIGID GFS. THE ECMWF
TENDED TO BE IN THE MIDDLE OF THE ROAD AND ALSO MATCHED UP WELL WITH
THE CRH_INIT SO LEFT THE TEMPERATURES ALONE AS RESULT OF THAT AND
THE MODEL DIFFERENCES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1036 AM MST TUE NOV 20 2012
VFR CONDITIONS ARE EXPECTED AT KGLD AND KMCK FOR THE NEXT 24
HOURS. RELATIVELY LIGHT SOUTH TO SOUTHWEST WINDS ARE EXPECTED WITH
A SURFACE TROUGH IN EASTERN COLORADO.
&&
.FIRE WEATHER...
ISSUED AT 205 AM MST TUE NOV 20 2012
RH VALUES THIS AFTERNOON WILL RANGE FROM 15 TO 20
PERCENT. WITH WIND GUSTS 20-25 MPH WE WILL BE VERY CLOSE TO RFW
CRITERIA. FOR NOW I AM NOT CONFIDENT WE WILL MEET THE 3HR
REQUIREMENT...NO RFW PLANNED FOR NOW.
CRITICAL FIRE WEATHER CONDITIONS WILL ALSO BE POSSIBLE WED
AFTERNOON WHEN RH VALUES BETWEEN 10 AND 20 PERCENT ARE EXPECTED
ALONG AND NORTHWEST OF A LINE FROM OBERLIN TO LEOTI KS. WINDS ARE
GOING TO BE LIGHTER IN THE WEST...WITH STRONGEST WINDS CURRENTLY
WHERE RH VALUES ARE FORECAST TO BE HIGHER. MOST LOCATIONS SHOULD
BE OUTSIDE OF RFW CRITERIA OTHER THAN A NARROW CORRIDOR SOUTH OF
INTERSTATE 70 WHERE THERE COULD SEE A CROSSOVER OF RH/WIND. THIS
IS GOING TO BE CLOSE...SO ITS WORTH MONITORING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...032
FIRE WEATHER...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
411 AM MST TUE NOV 20 2012
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 205 AM MST TUE NOV 20 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW A RIDGE EXTENDING NORTH
ACROSS THE CENTRAL AND HIGH PLAINS WITH A LARGE TROUGH JUST OFF THE
PACIFIC NORTHWEST COAST.
TODAY-WEDNESDAY...WITH SHORTWAVE RIDGE IN PLACE TODAY AND SW FLOW
ALOFT AND LARGE SCALE SUBSIDENCE ON WEDNESDAY DRY CONDITIONS ARE
EXPECTED. WITH WAA ON EASTERN EXTENT OF LEE TROUGH STRENGTHENING THE
NEXT FEW DAYS...WE SHOULD SEE TEMPERATURES IN THE 70S...WITH MID TO
UPPER 70S POSSIBLE ON WED. BREEZY CONDITIONS WILL ALSO DEVELOP OVER
PARTS OF THE AREA WITH GUSTS 20-30 MPH OVER PARTS OF THE AREA THE
NEXT FEW AFTERNOONS. SEE FIRE WEATHER SECTION REGARDING POSSIBLE RED
FLAG CONDITIONS THE NEXT FEW DAYS.
THURSDAY-THURSDAY NIGHT...A STRONG TROUGH WILL MOVE ALONG THE CANADA
US BORDER ON WED NIGHT AND THURSDAY...WITH A WEAKER LESS AMPLIFIED
SHORTWAVE MOVING ACROSS THE SOUTHERN STREAM. THE NORTHERN TROUGH
WILL KICK A COLD FRONT SOUTH OVER THE CWA THURSDAY...WITH WINDY
CONDITIONS EXPECTED THROUGH WED AFTERNOON. WE COULD SEE WIND ADVISORY
CRITERIA MET WITH BL WINDS 27-29KT AND H85 WINDS AROUND 40KT. ITS
STILL TOO EARLY FOR AN NPW...HOWEVER I DID INCREASE WINDS TO REFLECT
CURRENT THINKING. BEYOND FORCING IMMEDIATELY ALONG FRONT THE BEST
LARGE SCALE ASCENT IS WELL NORTH AND SOUTHEAST. THE AIR MASS ALSO
REMAINS VERY DRY ACROSS CWA...SO IM NOT ANTICIPATING ANY PRECIP.
WITH FROPA DURING THE DAY HIGH TEMPS THU ARE TRICKY...HOWEVER THEY
STILL SHOULD BE ABOVE NORMAL WITH A GRADIENT OF UPPER 50S IN THE
NORTH TO MID/UPPER 60S IN THE SOUTH. NEAR TO BELOW NORMAL LOW TEMPS
ARE EXPECTED THU NIGHT BEHIND THE FRONT WITH VALUES RANGING FROM THE
UPPER TEENS TO MID 20S.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 205 AM MST TUE NOV 20 2012
AT LEAST EARLY ON MODELS ARE CONSISTENT WITH THE PREVIOUS
FORECAST. COOLEST DAY WILL BE ON FRIDAY WITH MODERATION FOR
SATURDAY. THEN CHANGES AND INCONSISTENCIES BEGIN AFTER THAT. NEWER
MODEL DATA...ESPECIALLY THE ECMWF...IS NOW MORE PROGRESSIVE AND
NOT AS STRONG WITH INCOMING UPPER TROUGH AT THE BEGINNING OF NEXT
WEEK. GFS IS MUCH FASTER AND OLDER CANADIAN WAS MORE IN LINE WITH
THE ECMWF. IN ADDITION THE MODEL DATA BRINGS IN NOT JUST ONE
SHORTWAVE BUT A SERIES OF SHORTWAVE TROUGHS IN THE SUNDAY NIGHT
THROUGH MONDAY NIGHT TIME PERIOD.
THIS NEWER DATA IS FITTING THE PATTERN WE HAVE BEEN SEEING THIS
SEASON AND IN FACT THIS YEAR. THE TROUGH DOES NOT COME THROUGH IN
ONE NICE ORGANIZED SYSTEM BUT IN A SERIES OF SHORTWAVE TROUGHS.
ENSEMBLE DATA SUPPORTS THE MORE PROGRESSIVE AND MULTIPLE SHORTWAVE
SOLUTION AS WELL. THESE MULTIPLE SHORTWAVES HAVE TENDED TO SCOUR OUT
THE DEEPER MOISTURE THAT THE MODELS THINK IS THERE. BELIEVE THAT
THIS IS THE CASE HERE AS WELL. PLUS THE FRONT COMES THROUGH RATHER
EARLY AND BY SUNDAY NIGHT IS A GREAT DISTANCE SOUTH OF THE AREA. NO
SIGNIFICANT JET LIFT LOOKS TO BE INVOLVED AS WELL. AS A RESULT OF
ALL THIS AND COLLABORATION...KEPT THE SMALL AREAS OF SLIGHT CHANCE
POPS SUNDAY NIGHT AND MONDAY THE INIT GAVE ME AND REDUCED THE CHANCE
POPS FOR MONDAY NIGHT DOWN TO SLIGHT CHANCE.
BIG DIFFERENCES SHOWING UP IN THE LOW LEVEL THERMAL FIELD BEGINNING
ON SUNDAY. THE ECMWF WAS NOT AS COLD AS THE FRIGID GFS. THE ECMWF
TENDED TO BE IN THE MIDDLE OF THE ROAD AND ALSO MATCHED UP WELL WITH
THE CRH_INIT SO LEFT THE TEMPERATURES ALONE AS RESULT OF THAT AND
THE MODEL DIFFERENCES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 411 AM MST TUE NOV 20 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD AT BOTH KGLD AND
KMCK. LIGHT SOUTHWEST WINDS WILL SHIFT TO THE SOUTH AND INCREASE
AROUND MIDDAY AT KGLD AND EARLY THIS AFTERNOON AT KMCK AS A LEE
TROUGH STRENGTHENS OVER EASTERN COLORADO. WIND GUSTS THIS AFTERNOON
20-25KT WILL BE POSSIBLE WITH STRONGEST GUSTS AT KGLD. WINDS WILL
DIMINISH AROUND SUNSET AS DAYTIME HEATING COMES TO AN END.
&&
.FIRE WEATHER...
ISSUED AT 205 AM MST TUE NOV 20 2012
RH VALUES THIS AFTERNOON WILL RANGE FROM 15 TO 20
PERCENT. WITH WIND GUSTS 20-25 MPH WE WILL BE VERY CLOSE TO RFW
CRITERIA. FOR NOW I AM NOT CONFIDENT WE WILL MEET THE 3HR
REQUIREMENT...NO RFW PLANNED FOR NOW.
CRITICAL FIRE WEATHER CONDITIONS WILL ALSO BE POSSIBLE WED
AFTERNOON WHEN RH VALUES BETWEEN 10 AND 20 PERCENT ARE EXPECTED
ALONG AND NORTHWEST OF A LINE FROM OBERLIN TO LEOTI KS. WINDS ARE
GOING TO BE LIGHTER IN THE WEST...WITH STRONGEST WINDS CURRENTLY
WHERE RH VALUES ARE FORECAST TO BE HIGHER. MOST LOCATIONS SHOULD
BE OUTSIDE OF RFW CRITERIA OTHER THAN A NARROW CORRIDOR SOUTH OF
INTERSTATE 70 WHERE THERE COULD SEE A CROSSOVER OF RH/WIND. THIS
IS GOING TO BE CLOSE...SO ITS WORTH MONITORING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...DR
FIRE WEATHER...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
205 AM MST TUE NOV 20 2012
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 205 AM MST TUE NOV 20 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW A RIDGE EXTENDING NORTH
ACROSS THE CENTRAL AND HIGH PLAINS WITH A LARGE TROUGH JUST OFF THE
PACIFIC NORTHWEST COAST.
TODAY-WEDNESDAY...WITH SHORTWAVE RIDGE IN PLACE TODAY AND SW FLOW
ALOFT AND LARGE SCALE SUBSIDENCE ON WEDNESDAY DRY CONDITIONS ARE
EXPECTED. WITH WAA ON EASTERN EXTENT OF LEE TROUGH STRENGTHENING THE
NEXT FEW DAYS...WE SHOULD SEE TEMPERATURES IN THE 70S...WITH MID TO
UPPER 70S POSSIBLE ON WED. BREEZY CONDITIONS WILL ALSO DEVELOP OVER
PARTS OF THE AREA WITH GUSTS 20-30 MPH OVER PARTS OF THE AREA THE
NEXT FEW AFTERNOONS. SEE FIRE WEATHER SECTION REGARDING POSSIBLE RED
FLAG CONDITIONS THE NEXT FEW DAYS.
THURSDAY-THURSDAY NIGHT...A STRONG TROUGH WILL MOVE ALONG THE CANADA
US BORDER ON WED NIGHT AND THURSDAY...WITH A WEAKER LESS AMPLIFIED
SHORTWAVE MOVING ACROSS THE SOUTHERN STREAM. THE NORTHERN TROUGH
WILL KICK A COLD FRONT SOUTH OVER THE CWA THURSDAY...WITH WINDY
CONDITIONS EXPECTED THROUGH WED AFTERNOON. WE COULD SEE WIND ADVISORY
CRITERIA MET WITH BL WINDS 27-29KT AND H85 WINDS AROUND 40KT. ITS
STILL TOO EARLY FOR AN NPW...HOWEVER I DID INCREASE WINDS TO REFLECT
CURRENT THINKING. BEYOND FORCING IMMEDIATELY ALONG FRONT THE BEST
LARGE SCALE ASCENT IS WELL NORTH AND SOUTHEAST. THE AIR MASS ALSO
REMAINS VERY DRY ACROSS CWA...SO IM NOT ANTICIPATING ANY PRECIP.
WITH FROPA DURING THE DAY HIGH TEMPS THU ARE TRICKY...HOWEVER THEY
STILL SHOULD BE ABOVE NORMAL WITH A GRADIENT OF UPPER 50S IN THE
NORTH TO MID/UPPER 60S IN THE SOUTH. NEAR TO BELOW NORMAL LOW TEMPS
ARE EXPECTED THU NIGHT BEHIND THE FRONT WITH VALUES RANGING FROM THE
UPPER TEENS TO MID 20S.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 205 AM MST TUE NOV 20 2012
AT LEAST EARLY ON MODELS ARE CONSISTENT WITH THE PREVIOUS
FORECAST. COOLEST DAY WILL BE ON FRIDAY WITH MODERATION FOR
SATURDAY. THEN CHANGES AND INCONSISTENCIES BEGIN AFTER THAT. NEWER
MODEL DATA...ESPECIALLY THE ECMWF...IS NOW MORE PROGRESSIVE AND
NOT AS STRONG WITH INCOMING UPPER TROUGH AT THE BEGINNING OF NEXT
WEEK. GFS IS MUCH FASTER AND OLDER CANADIAN WAS MORE IN LINE WITH
THE ECMWF. IN ADDITION THE MODEL DATA BRINGS IN NOT JUST ONE
SHORTWAVE BUT A SERIES OF SHORTWAVE TROUGHS IN THE SUNDAY NIGHT
THROUGH MONDAY NIGHT TIME PERIOD.
THIS NEWER DATA IS FITTING THE PATTERN WE HAVE BEEN SEEING THIS
SEASON AND IN FACT THIS YEAR. THE TROUGH DOES NOT COME THROUGH IN
ONE NICE ORGANIZED SYSTEM BUT IN A SERIES OF SHORTWAVE TROUGHS.
ENSEMBLE DATA SUPPORTS THE MORE PROGRESSIVE AND MULTIPLE SHORTWAVE
SOLUTION AS WELL. THESE MULTIPLE SHORTWAVES HAVE TENDED TO SCOUR OUT
THE DEEPER MOISTURE THAT THE MODELS THINK IS THERE. BELIEVE THAT
THIS IS THE CASE HERE AS WELL. PLUS THE FRONT COMES THROUGH RATHER
EARLY AND BY SUNDAY NIGHT IS A GREAT DISTANCE SOUTH OF THE AREA. NO
SIGNIFICANT JET LIFT LOOKS TO BE INVOLVED AS WELL. AS A RESULT OF
ALL THIS AND COLLABORATION...KEPT THE SMALL AREAS OF SLIGHT CHANCE
POPS SUNDAY NIGHT AND MONDAY THE INIT GAVE ME AND REDUCED THE CHANCE
POPS FOR MONDAY NIGHT DOWN TO SLIGHT CHANCE.
BIG DIFFERENCES SHOWING UP IN THE LOW LEVEL THERMAL FIELD BEGINNING
ON SUNDAY. THE ECMWF WAS NOT AS COLD AS THE FRIGID GFS. THE ECMWF
TENDED TO BE IN THE MIDDLE OF THE ROAD AND ALSO MATCHED UP WELL WITH
THE CRH_INIT SO LEFT THE TEMPERATURES ALONE AS RESULT OF THAT AND
THE MODEL DIFFERENCES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 429 PM MST MON NOV 19 2012
VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD AS A RIDGE OF
HIGHER PRESSURE MOVES EAST OF THE ROCKIES AND AMPLIFIES OVER THE
CENTRAL HIGH PLAINS ON TUESDAY. HIGH CLOUDS WILL DISSIPATE WITH
SKIES BECOMING CLEAR AFTER 06Z. LIGHT AND VARIABLE WINDS WILL
BECOME LIGHT SOUTHWEST AFTER 06Z AND WILL BECOME GUSTY AFTER 18Z
TUESDAY AFTERNOON AS A LEE TROUGH BEGINS TO DEEPEN ALONG THE FRONT
RANGE.
&&
.FIRE WEATHER...
ISSUED AT 205 AM MST TUE NOV 20 2012
RH VALUES THIS AFTERNOON WILL RANGE FROM 15 TO 20
PERCENT. WITH WIND GUSTS 20-25 MPH WE WILL BE VERY CLOSE TO RFW
CRITERIA. FOR NOW I AM NOT CONFIDENT WE WILL MEET THE 3HR
REQUIREMENT...NO RFW PLANNED FOR NOW.
CRITICAL FIRE WEATHER CONDITIONS WILL ALSO BE POSSIBLE WED
AFTERNOON WHEN RH VALUES BETWEEN 10 AND 20 PERCENT ARE EXPECTED
ALONG AND NORTHWEST OF A LINE FROM OBERLIN TO LEOTI KS. WINDS ARE
GOING TO BE LIGHTER IN THE WEST...WITH STRONGEST WINDS CURRENTLY
WHERE RH VALUES ARE FORECAST TO BE HIGHER. MOST LOCATIONS SHOULD
BE OUTSIDE OF RFW CRITERIA OTHER THAN A NARROW CORRIDOR SOUTH OF
INTERSTATE 70 WHERE THERE COULD SEE A CROSSOVER OF RH/WIND. THIS
IS GOING TO BE CLOSE...SO ITS WORTH MONITORING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...LOCKHART
FIRE WEATHER...DR
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1131 PM CST MON NOV 19 2012
.UPDATE...
ISSUED AT 1131 PM CST MON NOV 19 2012
THE AVIATION SECTION HAS BEEN UPDATED FOR THE 06Z TAF ISSUANCE.
UPDATE ISSUED AT 849 PM CST MON NOV 19 2012
ALTHOUGH NOT REGISTERED THROUGH SURFACE OBSERVATIONS...THE KVWX
RADAR HAS BEEN DETECTING ENOUGH 20+ DBZ RETURNS AT 0.5 DEGREE
ELEVATION TO WARRANT THE POTENTIAL FOR AT LEAST ISOLATED SHOWERS
OR SPRINKLES REACHING THE SURFACE. WITH THIS IN MIND AND WITH THE
ASSISTANCE OF THE HRRR 1KM REFLECTIVITY GUIDANCE...ADDED A SMALL
POP/WEATHER CHANCE MAINLY OVER THE WEST KENTUCKY PENNYRILE THROUGH
05Z /11 PM CST/.
UPPER AIR CHARTS CONTINUE TO SHOW A SERIES OF MINOR WAVES ROTATING
INTO THE BROAD TROUGH WITH THE BASE WEST OF THE WFO PAH FORECAST
AREA. DESPITE FLUCTUATIONS IN CLOUD COVER FOR THE REMAINDER OF
TONIGHT...ADJUSTED THE NET OPAQUE CLOUD COVER TO MOVE THE CLOUDS
WITH THE MEAN FLOW THIS EVENING AND OVERNIGHT. GIVEN THAT
SCENARIO...HAD TO INCREASE MINIMUM TEMPERATURES 3-4
DEGREES. IN ADDITION...THE SOUTHERLY WIND COMPONENT SHOULD PERSIST
FURTHER INTO THE NIGHT AS AN AGEOSTROPHIC RESPONSE TO THE
APPROACHING SHORTWAVES. THIS SHOULD HELP BUOY TEMPERATURES AT MOST
LOCATIONS OVERNIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 149 PM CST MON NOV 19 2012
CLOUDS AND WEAK SHORT WAVE MOVING THROUGH THE CWA AT THIS TIME.
WATER VAPOR IMAGERY CLEARLY SHOWS DRIER AIR WORKING INTO SEMO WHICH
IS HELPING TO DRY UP ANY PRECIPITATION LEFT FROM THIS MORNING. MAY
HAVE HAD A FEW SPRINKLES OVER RIPLEY AND CARTER COUNTIES...BUT THAT
WAS ABOUT IT. THE CLOUDS HAVE AFFECTED TEMPERATURES WITH SEMO
REMAINING AROUND 60.
THIS CLOUD BANK WILL MOVE ACROSS THE AREA TONIGHT WHICH SHOULD KEEP
TEMPERATURES UP COMPARED TO LAST NIGHT. KEPT THE DRY FORECAST GOING
AS THE LOWEST 5K FT REMAIN DRY.
A SHORTWAVE SEEN ON SATELLITE OVER THE NORTHERN PLAIN WILL MOVE
THROUGH OUR AREA ON TUESDAY IN THE FORM OF A WEAK COLD FRONT. THE
FRONT SHOULD MOVE THROUGH DURING THE LATE MORNING INTO THE AFTERNOON
HOURS WHICH SHOULD ALLOW FOR DECENT HEATING AHEAD OF THE FRONT
EXCEPT FOR THE EXTREME EASTERN SECTIONS AS THE CLOUDS ARE EXPECTED
TO HANG ON THERE INTO THE EVENING HOURS. NO PRECIPITATION IS
EXPECTED WITH THIS FRONTAL PASSAGE.
DRIER AIR MOVING MOVES IN ON WEDNESDAY AND WITH CLEAR SKIES AND
LIGHT WIND SOME FOG POSSIBLE OVER WESTERN KENTUCKY WEDNESDAY NIGHT
INTO THURSDAY.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 149 PM CST MON NOV 19 2012
WE WILL START OUT ON THURSDAY WITH AN UPPER LEVEL RIDGE
OVERHEAD...THAT WILL BE MOVING EASTWARD WITH TIME. THE 12Z GFS
CONTINUES TO BE FASTER...THAN PREVIOUS RUNS AND THE ECMWF IN MOVING THE
RIDGE EAST AS THE NEXT SHORTWAVE TROUGH APPROACHES FROM THE WEST. BY
00Z FRI...THE 00Z ECMWF STILL HAS THE UPPER RIDGE OVER THE CWA WITH
THE IMPENDING SHORTWAVE ACROSS EASTERN KS/OK. THE 12Z GFS HAS THE
UPPER RIDGE AXIS OVER THE APPALACHIANS AT THAT SAME TIME WITH THE
SHORTWAVE TROUGH KNOCKING ON OUR WESTERN FRINGES.
THE GFS HAS SPENT SEVERAL RUNS TRYING TO FIGURE OUT WHETHER THE
WESTERN FRINGES OF THE CWA WILL SEE ANY PRECIP PRIOR TO 00Z
FRIDAY...BUT CONSENSUS SAYS THAT THINGS WILL PROBABLY STAY DRY. IN
FACT...THE 00Z/12Z ECMWF KEEPS US DRY THROUGH 06Z AND THIS MODEL HAS
BEEN FLIP FLOPPING ON THAT FOR A WHILE NOW TOO...WHETHER TO START
PRECIP ON THURSDAY EVENING OR OVERNIGHT. THE GFS INDICATE RAIN
SHOWERS SHOULD BE MOVING IN FROM THE WEST DURING THE EVENING HOURS
ON THANKSGIVING...MOVING EAST DURING THE OVERNIGHT HOURS. THE GFS
HAS HAD A PROBLEM OVER THE PAST 2 DAYS...FIGURING OUT HOW LONG THE
PRECIP WAS GOING TO LINGER ON FRIDAY.
RIGHT NOW...THE 12Z GFS INDICATE THAT FRIDAY MORNING MIGHT END UP
BEING DRY. THE SLOWER 00Z/12Z ECMWF STILL HOLDS ONTO RAIN CHANCES
THOUGH THROUGH THE MORNING HOURS...AT LEAST IN THE SOUTHEASTERN
HALF. THINK THE GOING FORECAST RESEMBLES A GOOD BLEND OF SEVERAL
DAYS OF MODEL RUNS AND IS A GOOD COMPROMISE TO ALL OF THOSE RUNS OF
THE GFS/ECMWF. THE BOTTOM LINE: CHANCES FOR RAIN WILL BEGIN TO
INCREASE AFTER 00Z FRIDAY...AND CONTINUE THROUGH THE NIGHT...AND
BEGIN TO TAPER OFF THROUGHOUT THE MORNING HOURS ON FRIDAY. RAINFALL
AMTS LOOK TO BE RATHER LIGHT AT THIS POINT...AND GFS ENSEMBLES
SUPPORT THIS AS WELL.
ON FRIDAY...A NORTHERN STREAM SHORTWAVE WILL BE MOVING ACROSS THE
NORTHERN PLAINS AND DOWN INTO THE UPPER MIDWESTERN STATES...AND
BRING A NICE POCKET OF COLD AIR WITH IT. AS HAS BEEN THE CASE FOR
SEVERAL DAYS NOW...THE ECMWF CONTINUES TO BE DEEPER WITH THIS TROUGH
AND HENCE BRINGS THE COLDER AIR FURTHER SOUTH. IN FACT...IT IS A
PRETTY POTENT POCKET OF COLD AIR...WITH THE ECMWF SHOWING H850 TEMPS
AROUND -11C DEG ACROSS OUR FAR NORTH. HOWEVER...IT APPEARS AS THOUGH
THE 12Z GFS HAS LOCKED INTO SOMETHING NOW SINCE IT TOO BRINGS COLDER
AIR FURTHER SOUTH. IT IS NOT QUITE LIKE THE ECMWF BUT AT LEAST IT IS
CLOSER. PLUS THE GFS ENSEMBLES ARE COLDER THAN THE OPERATIONAL GFS.
WE WILL DEFINITELY SEE A DROP IN TEMPS ON FRIDAY AS COLD AIR
ADVECTION WILL BE WELL UNDERWAY WITH BRISK NORTHERLY FLOW AT THE
SFC. IN FACT...MODELS HAVE BEEN TRENDING COLDER WITH EACH MODEL
RUN...SO WILL LOWER HIGHS. HIGHS ON SATURDAY WILL BE QUITE COOL FROM
WHAT WE HAVE BEEN USED TO THIS WEEK AND COULD END UP BEING 10 DEG
COLDER THAN ON FRIDAY...AS HIGH PRESSURE BUILDS IN AT THE SFC. THE
COLDEST TEMPS WILL BE IN OUR EASTERN SECTIONS...WHERE SOME OF THE
GUIDANCE IS GIVING HIGHS ONLY IN THE LOW 40S.
THERE IS NOW QUITE A BIT OF DIFFERENCE BTWN THE GFS AND ECMWF FOR
THE SYSTEM ON SUNDAY AND MONDAY. THE 12Z GFS SHOWS THE HIGH MOVING
EAST AS A MOISTURE STARVED COLD FRONT MOVES INTO THE REGION ON
SUNDAY. HOWEVER...ON SUNDAY NIGHT...MOISTURE BEGINS TO RETURN NORTH
IN EARNEST AND A WARM FRONT STARTS DEVELOPING TO OUR S/SW...WHICH
ENDS UP CAUSING SOME OVERRUNNING PRECIP ACROSS OUR SOUTHERN AREAS
LATE SUNDAY NIGHT AND INTO MONDAY. THE 00Z ECMWF IS SLOW TO MOVE THE
SFC HIGH EAST BUT FINALLY DOES SO SUNDAY AFTERNOON/NIGHT...ALLOWING
FOR SOUTHERLY FLOW TO TAKE OVER AND MOISTURE SLOWLY INCREASE OVER
THE AREA. HOWEVER...ANY CHANCES FOR RAIN LOOK TO HOLD OFF UNTIL
MONDAY/MONDAY NIGHT WITH THE ARRIVAL OF THE FRONT. STILL A LOT OF
UNCERTAINTY HERE BUT WHAT DOES SEEM PROBABLE AT THIS POINT IS
SEEING AN INCREASE IN TEMPERATURES ON SUNDAY AND MONDAY...BUT WE
WILL HAVE TO SEE WHAT HAPPENS WITH FUTURE RUNS ON THE NEXT CHANCE
FOR PRECIP. FOR NOW...HAVE ADDED A CHANCE FOR MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1131 PM CST MON NOV 19 2012
CEILINGS ARE EXPECTED TO FILL IN IN THE 4-6KFT LAYER ACROSS ALL
SITES BY MORNING. CEILINGS MAY SLIGHTLY LOWER THROUGH THE DAY AS
A WEAK COLD FRONT APPROACHES THE AREA. THIS FRONT IS LITTLE MORE
THAN A WIND SHIFT AND A WEAK ONE AT THAT...SO IT WILL BE OF LITTLE
CONSEQUENCE TO THE TAFS. WILL SHOW A SHIFT FROM WEST SOUTHWEST TO
NORTH NORTHWEST AT ALL SITES FROM 21Z-23Z...BUT THIS TIMING COULD
BE EARLIER OR LATER. WILL HAVE TO WATCH FOR SOME CEILINGS DROPPING
JUST INTO MVFR TERRITORY NEAR THE FRONT...BUT FOR NOW DO NOT SEE
ENOUGH EVIDENCE IN THE LATEST GUIDANCE TO INSERT IT IN THE
FORECAST.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...PS
LONG TERM....CW
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
641 PM EST WED NOV 21 2012
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 437 PM EST WED NOV 21 2012
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG EXTENDING
NEWD FM THE SRN PLAINS INTO THE GRT LKS BTWN A TROF ALONG THE E
COAST AND ANOTHER ALONG THE W COAST. THE AIRMASS ALOFT IS QUITE WARM
AND DRY OVER THE UPR GRT LKS...BUT LO CLDS ENHANCED BY RADIATIONAL
COOLING LAST NGT THAT FORMED UNDER SHARP LLVL INVRN SHOWN ON LOCAL
12Z RAOBS ARE PROVING TO BE QUITE RESILIENT OVER THE SCENTRAL AND
ERN CWA WITH ADDED MOISTENING OFF LK MI IN SSW FLOW BTWN HI PRES IN
THE MID ATLANTIC AND LOWER PRES IN THE PLAINS. THERE IS NO FOG/ST
NOTED TO THE W...BUT PLENTY OF HI CLDS ARE STREAMING ENEWD FM THE
PLAINS INTO THE UPR LKS IN THE WSW FLOW ALF. A POTENT SHRTWV IS
COMING ASHORE IN THE PAC NW.
LATE THIS AFTN...LO CLDS PRESENT EARLY THIS AFTN OVER THE SCENTRAL
AND E WILL BREAK UP THRU THE AFTN IN THE PRESENCE OF SOME DIURNAL
HEATING. THESE CLDS WL BE MOST RESILIENT OVER THE FAR E DOWNWIND OF
LK MI AS STLT IMAGERY SHOWS ST DECK EXTENDING ALMOST THE ENTIRE
LENGTH OF THE LK.
TNGT...ALTHOUGH THE ST SHOULD BE GONE THIS EVNG EXCEPT OVER THE FAR
E...SUSPECT THIS LO CLD WL FORM AGAIN TNGT WITH NOCTURNAL COOLING
AND PERSISTENT SSW FLOW/LO INVRN SHOWN ON FCST SDNGS. CONFIDENCE IN
THIS SCENARIO IS HIER SINCE THE 12Z NAM/LOCAL WRF-ARW SHOW HIER
H95-9 SPECIFIC HUMIDITY ADVECTING INTO THE AREA OVERNGT IN THE
STRENGTHENING LLVL SSW FLOW. H925 WINDS AS HI AS 30-40KTS BY LATE
TNGT SHOULD LIMIT THE POTENTIAL FOR DENSER FOG...BUT STILL ADDED
SOME PATCHY FOG OVER THE SCENTRAL AND E AWAY FM MORE PRONOUNCED
DOWNSLOPE WARMING OVER THE NW AND NCENTRAL AS MODELS HINT AT A
PERIOD OF LIGHTER WINDS THIS EVNG THAT MIGHT AUGMENT A PERIOD OF
QUICK COOLING. MIN TEMPS WL REMAIN WELL ABV NORMAL WITH INCRSG
WINDS/ QUITE A BIT OF HI CLD...ESPECIALLY IN THE DOWNSLOPE AREAS
OVER THE W AND NCENTRAL NEAR LK SUP.
THANKSGIVING DAY...WITH DIURNAL HEATING...EXPECT LO CLDS/FOG IN THE
MRNG TO BREAK UP BY NOON. BUT WITH PERSISTENT SSW FLOW...THE ST WL
MOST LIKELY LINGER LONGER INTO THE AFTN OVER THE E DOWNSTREAM OF LK
MI. ATTENTION THEN TURNS TO TIMING/IMPACT OF SHRTWV NOW MOVING INTO
THE PAC NW. MODELS SHOW THIS DISTURBANCE MOVING EWD TO OVER MN BY
00Z FRI. ALTHOUGH ASSOCIATED SFC LO PRES IS FCST TO MOVE INTO
ONTARIO JUST N OF LK SUP WITH ATTENDANT COLD FNT PROGGED TO REACH
CENTRAL UPR MI BY 00Z...DEEP LARGER SCALE FORCING IS FCST TO HANG TO
THE W THRU THAT TIME. WITH LINGERING MID LVL DRY AIR...ANY
ACCOMPANYING PCPN SHOULD PUSH NO FARTHER THAN WRN LK SUP UNTIL AFT
00Z. OTRW... LOOK FOR ANOTHER DAY OF WELL ABV NORMAL TEMPS UNDER H85
THERMAL RDG UP TO 11C RIGHT AHEAD OF THE FNT. BUT TEMPS OVER THE W
SHOULD FALL IN THE AFTN FOLLOWING THE COLD FROPA WITH H85 TEMPS
PROGGED TO TUMBLE TOWARD 0C AT IWD BY 00Z FRI.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 437 PM EST WED NOV 21 2012
MODEL HAVE COME INTO MUCH BETTER OVERALL AGREEMENT RELATING TO THE
SYSTEM THAT WILL BRING SNOW TO MUCH OF THE AREA THU NIGHT INTO
SAT...WITH MAINLY SMALLER SCALE/TIMING DIFFERENCES THAT ARE NOT OUT
OF THE NORM FOR THE TIME FRAME OF THE EVENT. A GENERAL MODEL
CONSENSUS WAS USED...WITH MOST FORECAST ALIGNMENT WITH THE 12Z/21
NAM/GFS AND TO A SOMEWHAT LESSER DEGREE THE 00Z/21 ECMWF
FOCUSED MAJORITY OF ATTENTION ON THE SYSTEM THU NIGHT INTO SAT GIVEN
HIGHER IMPACTS FROM POST THANKSGIVING TRAVEL/ACTIVITIES.
AT 00Z FRI...MODELS SHOW THE 500MB SHORTWAVE IN THE BEGINNING STAGES
OF BEING CLOSED OFF OVER NW MN WITH A 1000MB SFC LOW OVER CENTRAL
LAKE SUPERIOR...AND A SFC COLD FRONT FROM THE HURON MOUNTAINS TO
IRON OR DICKINSON COUNTY. 850MB TEMPS WILL BE JUST FALLING BELOW 0C
OVER FAR WRN UPPER MI...BUT WILL STILL BY AROUND 6C OVER THE ERN
CWA. THE MID LEVEL LOW WILL CONTINUE TO STRENGTHEN AS IT MOVES TO
THE CENTRAL CWA BY 12Z FRI /AVG LOCATION AMONG PREFERRED
MODELS...THERE WERE MINOR TIMING DIFFERENCES/...WITH HEIGHT FALLS OF
7-10DAM FROM 12 HOURS PREVIOUS. BY 12Z FRI THE BULK OF THE SFC LOW
WILL HAVE SHIFTED NE INTO ONTARIO...BUT PREFER THE NAM/GEM/ECMWF
SOLUTIONS THAT PIN A 998MB SFC LOW OVER NE LAKE SUPERIOR AS OFTEN
HAPPENS DUE TO THE WARM LAKE TEMPS. 850MB TEMPS FALL TO -10C TO -12C
OVER WRN LAKE SUPERIOR BY 12Z FRI...AND WILL WELL BELOW 0C OVER THE
REST OF THE CWA. THE COMBINATION OF THE DEEPENING SFC LOW...COLD AIR
OVER THE WARM LAKE AND SHARP PRESSURE GRADIENT LEAD TO STRONG WINDS.
THE STRONGEST WINDS LOOK TO BE OVER THE KEWEENAW AND NEAR LAKE
SUPERIOR E OF THE HURON MOUNTAINS...ESPECIALLY ALONG THE SHORELINES
OF ALGER AND LUCE COUNTIES. IN THESE AREAS...MODELS SHOW 925MB WINDS
IN EXCESS OF 40KTS...SO GUSTS AS HIGH AS 40KTS SEEM APPROPRIATE FOR
THE FORECAST IN THESE MORE EXPOSED LOCATIONS FROM THE NW WINDS LATE
THU NIGHT AND THROUGH MUCH OF FRI. A SHORT SWATH OF DRY LOW AND MID
LEVEL AIR ROTATES THROUGH THE WRN CWA LATE FRI MORNING...WHICH WILL
DIMINISH SNOWFALL TO SOME EXTENT. MODELS THEN INDICATE ANOTHER
SHORTWAVE PUSHING THROUGH SOMETIME SAT EVENING AS 850MB TEMPS FALL
TO -14C OVER MUCH OF LAKE SUPERIOR...WHICH WILL ACT TO ENHANCE
SNOWFALL RATES. AFTER THIS SHORTWAVE...SNOWFALL SHOULD GENERALLY
SLOWLY DIMINISH IN INTENSITY/COVERAGE UNTIL SFC AND UPPER RIDGING
MOVES IN FROM THE W SAT...REACHING IWD BY 18Z SAT AND THE FAR ERN
CWA AROUND 00Z SUN.
GIVEN HOW QUICKLY TEMPS GET COLD AS THE UPPER LOW IS MOVING
OVER...SNOW TO LIQUID RATIOS WILL JUMP UP PRETTY QUICKLY TO AROUND
18 TO 1 RATIOS. THIS WILL INCREASE SNOWFALL ACCUMULATIONS AND WILL
ALLOW THE SNOW TO BE BLOW AROUND MORE FROM GUSTY WINDS. EXPECT TWO
MAIN BURSTS OF SNOW THAT SHOULD BE ESPECIALLY UNTACTFUL...ONE AS THE
UPPER LOW PUSHES IN WITH LAKE ENHANCEMENT ADDING TO SNOW INTENSITY.
THIS WILL HAPPEN THU NIGHT INTO EARLY FRI MORNING OVER THE WRN
CWA...AND FRI MORNING TO AROUND NOON FRI OVER THE ERN CWA. THE
SECOND BURST LOOKS TO BE WITH THE SECOND SHORTWAVE FRI EVENING TO
EARLY SAT NIGHT WITH ENHANCEMENT OF THE LES. THE FIRST BURST OF SNOW
LOOKS TO BE THE WORST GIVEN THE INCREASED FORCING FROM THE 500MB
LOW...WHICH WILL ALSO BE AT THE WORST TIMES GIVEN MUCH INCREASED
POST THANKSGIVING TRAVEL/ACTIVITY AS FAR A SOCIETAL IMPACTS GO. THIS
IS COMPOUNDED BY THE FACT THAT NO SIGNIFICANT SNOWFALL HAS OCCURRED
IN A WHILE...WHICH LOCAL STUDIES SUGGEST LEADS TO A LARGE INCREASE
IN TRAFFIC ACCIDENTS ONCE SNOW DOES FALL.
AS FAR AS SNOWFALL AMOUNTS GO...HAVE HIGHEST CONFIDENCE IN SNOWFALL
AMOUNTS OF PORTIONS OF ALGER...LUCE AND NRN SCHOOLCRAFT COUNTIES
WHERE MOISTURE WILL LINGER LONGER AND THE FETCH ACROSS LAKE SUPERIOR
WILL BE BETTER AND NW WINDS WILL NOT CHANGE DIRECTIONS MUCH THROUGH
THE EVENT. OVER THESE ERN AREAS...THE NAM SHOWS STORM TOTAL QPF
/WHICH SHOULD BE ALMOST ALL SNOW/ OF JUST UNDER 0.80 INCHES...WHICH
MAY BE A BIT ON THE HIGH SIDE BUT CAN NOT BE RULED OUT.
OVERALL...THINK 6-10 INCHES /WITH SOME POTENTIAL FOR UP TO A FOOT/
TOTAL SNOWFALL SEEMS REASONABLE FOR THE ERN AREAS. LOWEST CONFIDENCE
IS OVER THE NRN HURON MOUNTAINS IN NW MARQUETTE AND NE BARAGA
COUNTIES...AS THIS AREA IS ALWAYS HARD TO FORECAST IN NW WINDS...BUT
WOULD THINK 3-5 INCHES STORM TOTAL SNOW IS REASONABLE. THE HIGHER
TERRAIN OF WRN UPPER MI FROM IWD TO CMX AND COPPER HARBOR SHOULD SEE
4-8 INCHES STORM TOTAL SNOW /HIGHEST OVER PORTION OF NRN HOUGHTON
COUNTY AND WRN ONTONAGON/NRN GOGEBIC COUNTIES/...BUT WITH MORE
UNCERTAINTY THAT THE ERN CWA AND MORE HIGHER POSSIBILITIES OF HIGHER
OR LOWER AMOUNTS. NCENTRAL PARTS OF THE CWA /GENERALLY IN THE
MARQUETTE-NEGAUNEE AREA/ LOOK TO SEE 1-3 INCHES OF SNOW THROUGH THE
ENTIRE PERIOD. SCENTRAL PORTIONS OF THE CWA SHOULD SEE LITTLE TO NO
SNOW.
HEADLINES FOR THIS EVENT ARE SOMEWHAT TRICKY IN THAT TRADITIONAL
SNOWFALL AMOUNT BASED CRITERIA WILL NEED TO BE RELAXED GIVEN A
VARIETY OF PREVIOUSLY DISCUSSED SOCIETAL IMPACTS AND OTHER
CONTRIBUTING FACTORS /SUCH AS GUSTY WINDS/. GIVEN HIGHER CONFIDENCE
OVER THE ERN CWA /ALGER...LUCE AND NRN SCHOOLCRAFT COUNTIES/ DECIDED
TO ISSUE A WINTER STORM WATCH FOR THESE AREAS. ELSEWHERE ALONG THE
LAKE SUPERIOR SHORE...ISSUED AN SPS HIGHLIGHTING POOR TRAVEL
CONDITIONS SINCE IT IS TOO FAR OUT FOR AN ADVISORY.
NEXT SYSTEM OF INTEREST MOVES OVERHEAD ON SAT NIGHT INTO EARLY SUN
AS A CLIPPER SYSTEM PUSHES THROUGH. BEST MOISTURE IS CO-LOCATED WITH
UPPER SUPPORT IN LEFT EXIT REGION OF UPPER JET OVER NRN PORTIONS OF
THE AREA. INCREASED CONSENSUS GUIDANCE TO MID RANGE CHANCE POPS. AT
THIS TIME A COUPLE OF INCHES OF SNOW APPEARS POSSIBLE...MAINLY IN
THE HIGHER TERRAIN OVER THE NRN CWA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 640 PM EST WED NOV 21 2012
AT KSAW...CONDITIONS WILL BE VFR INITIALLY...BUT RADIATIONAL COOLING
WILL LIKELY RESULT IN DEVELOPMENT OF SOME FOG AND LOW CLOUDS/IFR
CONDITIONS ONCE AGAIN TONIGHT. VFR CONDITIONS SHOULD PREVAIL AT
KIWD/KCMX TONIGHT AS DOWNSLOPE NATURE OF SSW FLOW SHOULD LIMIT THE
POTENTIAL FOR LOW CLOUDS/FOG. WITH INCREASING SSW WINDS OVERNIGHT
ABOVE RADIATION INVERSION...LLWS IS EXPECTED AT ALL 3 LOCATIONS.
DAYTIME HEATING/MIXING SHOULD END LLWS/DISSIPATE ANY LOW CLOUDS/FOG
BY LATE THU MORNING. ARRIVAL OF COLD FRONT LATE IN THE DAY WILL
LIKELY BRING LOW MVFR CIGS TO KIWD/KCMX AFTER 21Z.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 437 PM EST WED NOV 21 2012
EXPECT S WINDS UP TO 20 KTS THRU THIS EVENING TO INCREASE UP TO 25
KTS LATE TONIGHT AND THU UNDER TIGHTENING PRES GRADIENT AHEAD OF
COLD FRONT ASSOCIATED WITH POWERFUL DISTURBANCE MOVING ACROSS THE
NORTHERN CONUS. ONCE THE COLD FRONT MOVES WEST TO EAST THU AFTERNOON
AND NIGHT...EXPECT A SHARP WIND SHIFT TO THE NW. AS THE PRES
GRADIENT TIGHTENS CONSIDERABLY AND MUCH COLDER AIR MOVES OVER THE
UPPER LAKES...EXPECT A HI END GALE EVENT EXCEPT OVER THE FAR W WITH
THE COLDER AIR ENHANCING THE MIXING OF STRONGER WINDS ALOFT TO THE
LAKE SURFACE. GIVEN THE CONSISTENT FORECAST TIMING AND STRENGTH OF
THIS EVENT...OPTED TO UPGRADE GOING GALE WATCHES TO WARNINGS FOR THE
LATE THU NIGHT INTO FRI NIGHT PERIOD. SOME STORM FORCE WIND GUSTS
WILL ALSO BE POSSIBLE ON FRI...ESPECIALLY OVER THE E HALF OF THE
LAKE. THE APPROACH OF A HI PRES RIDGE LATE FRI NIGHT WILL CAUSE THE
GALES TO DIMINISH W-E THEN. ANOTHER LO PRES TROF WILL IMPACT THE
UPPER GREAT LAKES OVER THE WEEKEND...BUT A WEAKER PRES GRADIENT WILL
LIKELY HOLDS WINDS TO NO HIER THAN 25 KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER STORM WATCH FROM LATE THURSDAY NIGHT THROUGH LATE FRIDAY
NIGHT FOR MIZ006-007-085.
LAKE SUPERIOR...
GALE WARNING FROM 1 AM FRIDAY TO 1 AM EST SATURDAY FOR
LSZ264>267.
GALE WARNING FROM 1 AM TO 7 PM EST FRIDAY FOR LSZ243>245-248>251-
263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
338 AM CST TUE NOV 20 2012
.SHORT TERM...
CHALLENGE FOR THE FORECAST IN THE SHORT TERM INCLUDES WARM TEMPS
AND THEN LOW PRESSURE SYSTEM TRACKING ACROSS THE AREA THANKSGIVING DAY
AND NIGHT. MODELS IN FAIR AGREEMENT THUS USED A BLEND THROUGH THE
MID WEEK.
SOME UNCERTAINTY WITH COVERAGE AND DEPTH OF FOG DEVELOPMENT THIS
MORNING AND ITS EVOLUTION TODAY. HRRR MODEL DEVELOPS WIDE AREA OF
FOG OVER THE MN PINES AND LAKES AND THEN SLOWLY ADVECTS IT TO THE
WEST AND NORTH OVER THE VALLEY DURING THE DAY TODAY. THIS SCENARIO
WOULD DRASTICALLY LOWER FORECASTED HIGHS TODAY...THOUGH HRRR DID
INITIALIZE WITH MORE FOG AT 08Z THAN WHAT IS CURRENTLY SEEN IN SFC
OBS. CURRENT THINKING IS THAT FOG WILL BE LESS DENSE AND ABLE TO
ERODE THIS MORNING AND ALLOW GOOD SOLAR SOME WAA ON SOUTH TO
SOUTHEAST WINDS ON THE BACKSIDE OF THE DEPARTING HIGH TO ALLOW HI
TEMPS TO REACH MID 40S.
LOW LEVEL WARM ADVECTION CONTINUES OVERNIGHT WITH GOOD MIXING
KEEPING TEMPS UP NEAR THE FREEZING MARK WEDNESDAY MORNING. THESE WARM
LOWS WILL BE SETTING THE STAGE FOR HIGHS IN THE MID 50S SOUTH...
NEAR THE RECORD OF 58 AT FARGO... TO NEAR 50 ALONG THE SNOW LINE
AS 850MB TEMPS RANGE FROM 10C IN THE NORTH TO 14 C IN THE SOUTH.
MODELS IN GOOD AGREEMENT WITH SFC LOW PRESSURE TO TRACK ACROSS THE
AREA EARLY THURSDAY MORNING. BEHIND THE ATTACHED COLD FRONT CHC
OF RAIN IN THE MORNING WILL GIVE WAY TO SNOW FROM NW TO SE AS THE
COLUMN COOLS. TEMPS LIKELY TO FALL DURING THE DAY AS THE COLD AIR
SPILLS INTO THE REGION ON THE NW WINDS. A MIXED PCPN TYPE IS
POSSIBLE BEFORE MEASURABLE SNOWFALL STARTS TO ACCUMULATE ACROSS
THE NORTHERN HALF OF THE CWFA THURSDAY AFTERNOON AND EVENING. BY
00Z FRI ALL PCPN WILL BE FROZEN WITH SNOW LIKELY ACROSS THE N RRV
AND INTO NW MN AS THE DEFORMATION SNOW BAND ORGANIZES OVERNIGHT.
WINDS WILL ALSO BE A FACTOR WITH THIS SYSTEM AS STRONG TO BLUSTERY
CONDITIONS ARE EXPECTED WITH 40 TO 50KTS AT 850MB THURSDAY NIGHT
COMBINED WITH THE AFOREMENTIONED SNOW COULD TRAVEL DIFFICULT
ACROSS PORTIONS OF THE CWFA. GIVEN THE HOLIDAY AND TRAVEL PLANS
INDIVIDUALS SHOULD CONTINUE TO MONITOR FUTURE FORECASTS.
.LONG TERM (FRIDAY-MONDAY)...MODELS ARE IN GOOD AGREEMENT WITH
TRENDS BUT A BIT DIFFERENT WITH DETAILS. THE GENERAL IDEA IS FOR
NORTHWEST FLOW ALOFT WITH A STRONGER SYSTEM/COLD FRONT SATURDAY
NIGHT OR SUNDAY. THE MAIN ISSUE WILL BE WINDS WITH THE FROPA AND
THEN WELL BELOW NORMAL TEMPERATURES BEHIND THIS FEATURE (WITH NOT
MUCH SNOWFALL).
&&
.AVIATION...
HIGH PRESSURE ALLOWING PATCHY TO DENSE FOG FORMATION AND IFR
CONDITIONS TO DEVELOP AT FAR...TVF AND BJI. DVL ALREADY SEEING S
WINDS AND SHOULD REMAIN AT VFR. GFK JUST WEST OF THE FOG FOR
NOW...IF IT EXPANDS...A GOOD POSSIBILITY IN THE NEXT 6 HR...GFK
TO SEE IFR. IFR CONDITIONS TO LIFT TO MVFR IN LATE MORNING BEFORE
SCT OUT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
JK/TG
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
840 PM EST WED NOV 21 2012
.SYNOPSIS...
HIGH PRESSURE WILL KEEP WARM AND DRY CONDITIONS ACROSS THE REGION
THROUGH THANKSGIVING. A COLD FRONT WILL MOVE THROUGH THE AREA
FRIDAY MORNING. TEMPERATURES WILL FALL FRIDAY AFTERNOON AND BE
WELL BELOW NORMAL OVER THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
FOR THE EVENING UPDATE ADDED PATCHY TO AREAS OF FOG MAINLY FOR
THE NORTHWESTERN PORTIONS OF THE FORECAST AREA AFTER MIDNIGHT
TONIGHT. TEMP/DEWPOINT SPREADS ARE NARROWING RAPIDLY THIS EVENING
ACROSS THESE AREAS WITH FOG ALREADY DEVELOPING JUST TO OUR
NORTHWEST. THIS TREND HAS BEEN INDICATED WELL BY THE RAP SURFACE RH
FIELDS THIS AFTERNOON AND THEREFORE IS BEING FOLLOWED FOR THE FOG
FORECAST FOR TONIGHT. OTHERWISE MADE NO ADJUSTMENTS TO THE
PREVIOUS FORECAST EXCEPT ADDING A FEW CIRRUS TO THE SKY GRIDS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
SOUTHERLY WINDS WILL OCCUR BETWEEN RETREATING HIGH PRESSURE AND AN
ADVANCING COLD FRONT THURSDAY AND THURSDAY EVENING. THIS WILL LEAD
TO WELL ABOVE NORMAL TEMPERATURES ONCE AGAIN. HIGH CLOUDS WILL
START STREAMING INTO THE REGION DURING THIS PERIOD.
THE COLD FRONT WILL MOVE INTO WESTERN SECTIONS VERY LATE THURSDAY
NIGHT AND CROSS THE REST OF THE FORECAST AREA FRIDAY MORNING.
THERE WILL BE SHOWERS WITH THE COLD FRONT. BUT THERE IS SOME
UNCERTAINTY ABOUT COVERAGE OF MEASURABLE RAIN. SO HAVE GONE HIGH
CHANCE AND LOW LIKELY FOR THE REGION LATE THURSDAY NIGHT AND
FRIDAY MORNING. SHOWERS WILL CLEAR OUT BY MIDDAY FRIDAY WITH
CLOUDS DECREASING. TEMPERATURES SHOULD STAY RATHER WARM UNTIL
FRONTAL PASSAGE EXCEPT FOR FAR EASTERN/SOUTHEASTERN COUNTIES WHERE
READINGS MAY DROP OFF EARLY THURSDAY NIGHT. LOOKS LIKE A SITUATION
WHERE THERE COULD BE 13Z LOWS AND 12Z HIGHS IN MANY LOCATIONS WITH
READINGS FALLING THROUGH THE REST OF FRIDAY. WINDS WILL BE GUSTY
BEHIND THE COLD FRONT WITH WIND CHILL VALUES DROPPING INTO THE
UPPER 20S TO MID 30S BY LATE IN THE DAY.
WINDS WILL DIMINISH SOMEWHAT FRIDAY NIGHT. ADDITIONAL CLOUD COVER
MAY SPREAD INTO THE REGION WITH COLD AIR ADVECTION AND CYCLONIC
FLOW OVER THE GREAT LAKES. FELT THAT GFS MOS LOWS LOOKED MORE
REASONABLE IN THIS SCENARIO.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
COLD AIR MASS WILL BE IN PLACE ACROSS THE AREA ON SATURDAY WITH HIGH
TEMPERATURES ONLY IN THE MIDDLE 30S. WITH WINDS OFF OF LAKE
MICHIGAN ON SATURDAY SOME LIGHT LAKE EFFECT SNOW SHOWERS WILL BE
POSSIBLE ACROSS NORTHERN PORTIONS OF THE FA. H8 WINDS WILL BECOME
MORE WESTERLY SATURDAY EVENING AND PRECIPITATION CHANCES WILL COME
TO AN END ACROSS THE FA. CLOUD COVER WILL DECREASE ACROSS THE AREA
SATURDAY NIGHT ALLOWING TEMPERATURES TO DROP DOWN INTO THE LOW 20S
ACROSS MOST LOCATIONS. WARMER AIR WILL GRADUALLY START TO WORK INTO
THE AREA LATE DURING THE OVERNIGHT SATURDAY NIGHT AND THIS SHOULD
HELP TO KEEP TEMPERATURES FROM FALLING INTO THE TEENS. TEMPERATURES
CLIMB INTO THE 40S ON SUNDAY ACROSS THE AREA WITH SW FLOW HOWEVER
THESE VALUES ARE STILL BELOW NORMAL FOR THIS TIME OF YEAR.
THE MODELS START TO DIVERGE WITH THE STORM SYSTEM BEGINNING TO
IMPACT THE AREA ON MONDAY. MODELS HAVE SHOWN QUITE A BIT OF RUN TO
RUN INCONSISTENCY WITH THIS FEATURE. THE LATEST 12Z ECMWF HAS
SHIFTED THE LOW QUITE A BIT FURTHER SOUTH FROM THE PREVIOUS MODEL
SOLUTIONS AND HAVE DECIDED NOT TO JUMP ON THIS LATEST RUN JUST YET.
INSTEAD...WENT WITH A 12Z GFS 00Z ECMWF BLEND. PRECIPITATION WILL
BEGIN TO MOVE INTO THE AREA ON MONDAY WITH A GREATER COVERAGE IN
PRECIPITATION EXPECTED MONDAY EVENING INTO TUESDAY. PRECIPITATION
WILL GENERALLY BE IN THE FORM OF RAIN THROUGH THE DAYTIME HOURS ON
TUESDAY EXCEPT FOR A LITTLE SNOW THAT MAY MIX IN AT TIMES ACROSS THE
NORTH MONDAY INTO MONDAY NIGHT. WITH THE 12Z GFS 00Z ECMWF BLEND
HAVE THE AREA OF LOW PRESSURE MOVING ALONG AND JUST NORTH OF THE
INTERSTATE 71 CORRIDOR ON TUESDAY. COLDER AIR WILL QUICKLY WORK
INTO THE AREA TUESDAY NIGHT AND ANY RESIDUAL PRECIPITATION WILL
BEGIN TO CHANGE OVER TO SNOW ACROSS THE REGION. DRY CONDITIONS WILL
RETURN TO THE AREA BY WEDNESDAY MORNING.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
MOSTLY CLEAR SKIES AND SUFFICIENT SURFACE MOISTURE SHOULD ALLOW
FOR RIVER VALLEY FOG TO AFFECT KLUK...WITH LESS DENSE GROUND
FOG/MIST TO AFFECT KCVG/KDAY/KILN LATE TONIGHT. KLUK WILL LIKELY
HAVE IFR VSBYS BEFORE SUNRISE. AFTER SUNRISE...EXPECT ANY FOG/MIST
TO QUICKLY DIMINISH WITH MAINLY SCATTERED CIRRUS PASSING BY. WINDS
WILL INCREASE DURING THE LATE MORNING OUT OF THE SOUTH TO AROUND
10 KTS...LASTING INTO THE EVENING.
OUTLOOK...MVFR CEILINGS AND VISIBILITIES POSSIBLE FRIDAY. MVFR
CEILINGS POSSIBLE SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...LATTO
SHORT TERM...
LONG TERM...NOVAK
AVIATION...LATTO
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
320 PM EST TUE NOV 20 2012
.SYNOPSIS...
A WEAKENING COLD FRONT OVER NORTHWEST OHIO WILL DISSIPATE AS IT
MOVES ACROSS THE LOCAL AREA TONIGHT. HIGH PRESSURE WILL RETURN
FOR WEDNESDAY AND THE THANKSGIVING HOLIDAY. A STRONGER COLD FRONT
IS EXPECTED TO ARRIVE ON FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
RADAR CONTINUES TO SHOW SOME WEAK RETURNS WITH A LEGITIMATE SHOWER
OVER RICHLAND COUNTY. A FEW SHOWERS HAVE COME AND GONE THE PAST
HOUR OR SO. WILL GO WITH A 20 POP OVER MUCH OF THE AREA THROUGH
00Z OR SO TO COVER ANY NEW DEVELOPMENT. LATEST HRRR INDICATES THAT
THIS IS A REASONABLE SCENARIO. WHAT IS LEFT OF THE COLD FRONT HAS
MOVED INTO NW OH AND SHOULD BE COMPLETELY GONE BY LATE EVENING.
HAVE SEEN SOME BREAKS IN THE CLOUDS RECENTLY BUT THINK THE FLAVOR
OF THE NIGHT WILL BE MOSTLY CLOUDY AS STRATO CU BEHIND THE FRONT
MOVES INTO THE AREA. GUIDANCE TEMPS LOOK REASONABLE.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY NIGHT/...
WE SHOULD SEE A DECREASE IN THE CLOUDS TOMORROW WITH PARTLY
CLOUDY TO MOSTLY SUNNY SKIES BY LATE AFTERNOON. TEMPS WILL BE A
DEGREE OR TWO WARMER THAN TODAY GIVEN THE SUNSHINE. EVEN WARMER
READINGS ARE EXPECTED FOR THANKSGIVING AS THE RIDGE AXIS WILL BE
JUST EAST OF THE AREA. ABUNDANT SUNSHINE IS ALSO EXPECTED. THE
MODELS CONTINUE TO BE IN DECENT AGREEMENT WITH THE COLD FRONTAL
PASSAGE ON FRIDAY. THE FRONT SHOULD BE INTO NW PA BY EARLY
AFTERNOON. ALL OF THE NEW GUIDANCE IS SHOWING A LINE OF SHOWERS
ALONG THE FRONT AND HAVE BUMPED POPS UP SLIGHTLY. EXPECT THAT
LATER SHIFTS MAY EVENTUALLY NEED TO GO WITH LIKELY OR HIGHER
WORDING. GOOD COLD AIR ADVECTION IS EXPECTED BEHIND THE FRONT WITH
850 MB TEMPS DIPPING TO AROUND NEG 10 BY 12Z SAT. WILL NEED TO HANG
ON TO SOME LAKE EFFECT PRECIP FRIDAY NIGHT OVER MOST OF THE AREA.
HAVE USED A BLEND OF GUIDANCE TEMPS DURING THE PERIOD.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
A DECENT LAKE EFFECT SHSN EVENT STILL LOOKS IN ORDER FOR SAT INTO
SAT NIGHT TAPERING TO MAINLY FLURRIES BY SUN MORNING AS RIDGE OF
HIGH PRESSURE MOVES OVERHEAD. THE RIDGE SHOULD BRIEFLY STOP THE
PRECIP THEN ANOTHER SYSTEM IS EXPECTED TO APPROACH THE AREA WITH
MOISTURE ARRIVING MONDAY. THE MODELS DIFFER GREATLY BY TUE SO WILL
CONTINUE A SMALL CHANCE FOR RAIN OR SNOW INTO TUE THUS LEANING MORE
TOWARD THE ECMWF AS THE GFS LOOKS TO BE TRENDING MORE THAT WAY TOO.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
VFR SHOULD PREVAIL MOST OF THE TIME THROUGH THE TAF PERIOD. CIGS MAY
LOWER IN THE WEST CLOSER TO MVFR LEVELS INTO TONIGHT. PATCHY MVFR
FOG MAY DEVELOP AT SOME TAF SITES LATE TONIGHT. WINDS WILL STAY
LIGHT.
OUTLOOK...NON-VFR SHOULD OCCUR FRIDAY SHIFTING TO MAINLY THE
SNOWBELT FOR SAT AND SAT NIGHT WITH SHRA CHANGING TO SHSN. VFR
SHOULD RETURN MOST SITES SUNDAY.
&&
.MARINE...
A RIDGE ACROSS THE LAKE WILL SHIFT SOUTHEAST LATE WEDNESDAY AND THAT
WILL ALLOW A SOUTHWEST FLOW TO DEVELOP. THE SOUTHWEST FLOW WILL
CONTINUE TO INCREASE THROUGH THURSDAY NIGHT BUT WITH THE LAKE AND
850 MB TEMPERATURE DIFFERENCE NEAR 0C...STABLE...IT WILL BE TOUGH
FOR THOSE STRONGER WINDS TO GET TO THE LAKE SURFACE. A SMALL CRAFT
ADVISORY MAY BE NEEDED BY LATE THURSDAY NIGHT WITH WINDS OF 15 TO 25
KNOTS. GOING WITH THE SLOWER GFS/ECMWF SOLUTIONS WHICH HAS THE COLD
FRONTAL PASSAGE AND A LITTLE STRONGER WINDS FOR LATE FRIDAY. IT IS
POSSIBLE THAT WINDS COULD BE CLOSE TO GALE FORCE MAINLY ON THE EAST
END OF THE LAKE FRIDAY AFTERNOON. AT THIS TIME IT LOOKS VERY
MARGINAL AND BRIEF...THIS WILL HAVE TO BE MONITORED. THE WATER LEVEL
WILL ALSO HAVE TO BE WATCHED ON THE WEST END OF THE LAKE FRIDAY AND
FRIDAY NIGHT. NONE THE LESS A SMALL CRAFT ADVISORY WILL LIKELY BE
NEED FROM LATE THURSDAY NIGHT THROUGH EARLY SATURDAY NIGHT. LATE
SATURDAY NIGHT AND ON SUNDAY THE WINDS SHIFT TO THE SOUTHWEST AS A
RIDGE MOVES EAST OF THE LAKE. ANOTHER FRONT OR TROF WILL MOVE ACROSS
THE LAKE LATE SUNDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KUBINA
NEAR TERM...KUBINA
SHORT TERM...KUBINA
LONG TERM...ADAMS
AVIATION...TK
MARINE...KIELTYKA
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
928 PM CST WED NOV 21 2012
.DISCUSSION...
STILL A LITTLE MIXY WITH SOUTHWESTERLY LOW LEVEL JET OVER EASTERN
PART OF THE AREA. THIS HOLDING TEMPERATURES UP THIS EVENING...WITH
READINGS STILL IN THE MID 50S TO LOWER 60S AS OF 03Z. MODELS DO NOT
HAVE A GREAT GRASP ON THIS...WITH RAP THE CLOSEST THOUGH STILL A FEW
DEGREES SHY AT 03Z. TREND IN THIS MODEL SEEMS REASONABLE THOUGH...
WITH SLOW FALL AHEAD OF PRE-FRONTAL TROUGH...WHICH WILL TURN WINDS
MORE WESTERLY AND SOMEWHAT LIGHTER OVERNIGHT. SHOULD SEE GREATER
FALL AFTER THIS TROUGH PASSAGE...AND WITH COLD ADVECTION BEGINNING
TO PUSH INTO WESTERN PARTS OF THE CWA PRIOR TO DAYBREAK...WILL LET
GOING LOWS RIDE WITH MINIMAL CHANGES. UPDATED GRIDS/PFM HAVE BEEN
SENT.
&&
.AVIATION.../FOR THE 00Z TAF ISSUANCE/
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. SOUTHEASTERLY WINDS
OVERNIGHT WILL TRANSITION TO NORTHWESTERLY AND INCREASE EARLY ON
THURSDAY...WITH GUSTS OF 30 TO 40 KTS LIKELY BY LATE MORNING AND
AFTERNOON. OTHER AREA OF CONCERN IS LOW LEVEL WIND SHEAR AT KSUX
THIS EVENING AS SURFACE WINDS FALL OFF AND 40 KT PLUS WINDS DEVELOP
AROUND 1000 FT. SHOULD SEE SOME STATUS FORM BEHIND THE FRONT
TOMORROW AS WELL. CURRENTLY THINKING ANY MVFR CIGS STAY NORTH OF OUR
CWA...ALTHOUGH WILL HAVE TO WATCH KHON...AS THEY COULD SEE A BRIEF
PERIOD OF MVFR CIGS RIGHT BEHIND THE FRONT...BEFORE DRYING AND
CLEARING TAKES PLACE. /CHENARD
&&
.PREV DISCUSSION.../ISSUED AT 241 PM CST/
BRISK SOUTH SOUTHWESTERLY FLOW WILL CONTINUE ACROSS MUCH OF THE AREA
TONIGHT WITH THE APPROACH OF A SURFACE TROUGH FROM THE WEST. THIS
WILL ALLOW FOR WINDS TO STAY UP OVERNIGHT...MORE SO IN THE
EAST...AND IT WILL BE A MILD NIGHT WITH LOWS PRIMARILY IN THE 40S.
THE SURFACE TROUGH/FRONTAL BOUNDARY WILL SWING THROUGH THE AREA ON
THURSDAY...AND WITH STRONG COLD AIR ADVECTION/STEEP LOW LEVEL LAPSE
RATES/WINDS GENERALLY 40 TO 45 KTS AT THE TOP OF THE MIXED LAYER/AND
A TIGHTENING GRADIENT IT WILL BE A WINDY DAY...AND EXPANDED THE WIND
ADVISORY OVER THE ENTIRE CWA. WHILE THE ADVISORY WILL BE MARGINAL IN
SOME AREAS...AND STRONGEST WINDS MAY ONLY PERSIST FOR 2 OR 3 HOURS
WITH THE FRONTAL PASSAGE...FOR THE SAKE OF SIMPLICITY AND
COORDINATION WITH SURROUNDING OFFICES ELECTED TO INCLUDE THE ENTIRE
AREA AS CRITERIA IS EXPECTED TO BE CLOSE ENOUGH. WHILE THE COLDEST
AIR WILL NOT COME IN UNTIL THURSDAY NIGHT...WITH 925 MB TEMPERATURES
PROGGED TO BE A GOOD 10 TO 15 DEGREES C COOLER ON THURSDAY AFTERNOON
OVER TODAY...WILL HAVE HIGHS RANGING FROM THE UPPER 40S TO
MID 50S ACROSS THE AREA...THOUGH IT WILL OBVIOUSLY FEEL COLDER WHEN
THE WINDS ARE FACTORED IN.
A STRONG SURGE OF COLD AIR WILL MOVE SOUTH ON THURSDAY NIGHT ALONG
WITH GUSTY NORTHWEST WINDS. MODELS IN PRETTY GOOD AGREEMENT WITH THE
AMOUNT OF COOLING...JUST SOME MINOR DIFFERENCES ON THE TIMING OF THE
FRONT. THE NAM SEEMS TO HANDLE THESE LOW LEVEL FRONTAL FEATURES BEST
THIS TIME OF YEAR SO USED THAT TO ACCOUNT FOR THE SOMEWHAT NON
DIURNAL NATURE OF TEMPERATURES AS THEY DROP THROUGH THE EARLY
MORNING OF FRIDAY BEFORE SLOWLY RISING THROUGH THE DAY. LOWS WILL BE
MODERATED A BIT BY THE STRONG FLOW SO WENT CLOSEST TO THE CONSRAW
OUTPUT WHICH HANDLES WINDY NIGHTS THE BEST...SO MAINLY LOWER TO MID
20S FOR LOWS. HIGH TEMPERATURES FRIDAY WILL NOT REBOUND MUCH AS COLD
ADVECTION CONTINUES AND CLOUDS IN THE EAST ARE SLOW TO ERODE. MAINLY
AIMING FOR 250 TO 30 IN THE EAST AND 30 TO 35 IN THE WEST.
FRIDAY NIGHT INTO SATURDAY WILL SEE A FAST MOVING SURFACE HIGH
PRESSURE MOVE THROUGH WITH BREEZY SOUTHERLY FLOW DEVELOPING ON
SATURDAY. TWEAKED LOWS DOWN JUST A TOUCH IN THE EASTERN CWA AND LEFT
THEM ABOUT AS IS IN THE WESTERN CWA. WITH THE RETURN FLOW SETTING UP
IN THE FAR SOUTH AND WEST CWA ALSO HAVE GRADUALLY WARMING
TEMPERATURES IN THOSE AREAS THROUGH SUNRISE. BY SATURDAY THIS STRONG
SOUTHERLY FLOW WILL BE IN PLACE WITH A FAIRLY STRONG THERMAL
GRADIENT DEVELOPING ACROSS THE CWA. EXPECTING TEMPERATURES TO
STRUGGLE A BIT IN THE EAST WHERE SOUTHERLY WINDS WILL BE SLOW TO SET
UP...SO ONLY MID 30S. IN THE SOUTHWEST CWA A SURGE OF WARMER AIR
SHOULD ALLOW TEMPERATURES TO BUMP UP INTO THE LOWER 50S.
IN THE LATTER PERIODS(SUN/WED)...A TROUGH OF LOW PRESSURE WILL DIG
INTO THE CENTRAL ROCKIES SUNDAY AFTERNOON THEN SPREAD ACROSS THE
CENTRAL PLAINS SUNDAY NIGHT INTO MONDAY. WHILE THERE WILL BE A SMALL
CHANCE FOR LIGHT SNOW DURING THIS TIME...WITH SO MUCH NORTHWEST JET
ENERGY UPSTREAM FEEL THAT THE WAVE MAY DIG A LITTLE FARTHER SOUTH
THAN MODELS CURRENTLY PROJECT SO DO NOT PLAN ON INCREASING
PROBABILITIES FOR MEASURABLE SNOWFALL. IF THE WAVE DOES DIVE A
LITTLE FARTHER SOUTHWEST ON SUNDAY THE AMOUNT OF WARM AIR THAT MAKES
IT THIS FAR NORTH WILL BE MINIMAL WITH A NORTH TO NORTHEAST WIND
DEVELOPING THROUGH THE DAY. WILL CONTINUE TO KEEP HIGHS FAIRLY COOL
BUT SEASONAL FROM THE UPPER 30S NORTH TO THE MID 40S SOUTH. AS THE
WAVE PASSES ON SUNDAY NIGHT COLDER AIR WILL POUR INTO THE REGION
SETTING UP A FAIRLY COLD MONDAY THROUGH THURSDAY TIME PERIOD. WILL
CONTINUE TO LEAN TOWARDS THE MORE CONSISTENT ECMWF WHICH BUILDS THE
HIGH PRESSURE SOUTH AND IS MORE STUBBORN ABOUT ALLOWING WARM AIR TO
SURGE NORTHEAST AS A WEAK WAVE PASSES ON TUESDAY NIGHT INTO
WEDNESDAY. /08
&&
.FIRE WEATHER.../ISSUED AT 333 PM CST/
THANKSGIVING DAY WILL SEE VERY STRONG NORTHWEST WINDS DEVELOP DURING
THE DAY AND WITH VERY DRY CONDITIONS A VERY HIGH FIRE DANGER WILL BE
IN PLACE. THE STRONGEST WINDS WILL BE IN CENTRAL SOUTH DAKOTA DOWN
THE MISSOURI RIVER VALLEY THROUGH EARLY AFTERNOON...THEN TRANSITION
INTO EASTERN SOUTH DAKOTA...SOUTHWEST MINNESOTA AND NORTHWEST IOWA
FROM EARLY AFTERNOON INTO THE EVENING.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...WIND ADVISORY FROM NOON TO 6 PM CST THURSDAY FOR IAZ001>003-
012>014-020>022-031-032.
MN...WIND ADVISORY FROM NOON TO 6 PM CST THURSDAY FOR MNZ071-072-080-
081-089-090-097-098.
NE...WIND ADVISORY FROM 9 AM TO 6 PM CST THURSDAY FOR NEZ013.
WIND ADVISORY FROM NOON TO 6 PM CST THURSDAY FOR NEZ014.
SD...WIND ADVISORY FROM 9 AM TO 6 PM CST THURSDAY FOR SDZ038-050-052-
053-057>060-063>066-068>070.
WIND ADVISORY FROM NOON TO 6 PM CST THURSDAY FOR SDZ039-040-
054>056-061-062-067-071.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
959 PM CST WED NOV 21 2012
.UPDATE...
QUICK UPDATE TO TWEAK OVERNIGHT WINDS...TEMPS...AND DEWPOINTS UPWARD BASED
ON CURRENT TRENDS.
KB
&&
.PREV DISCUSSION... /ISSUED 518 PM CST WED NOV 21 2012/
AVIATION...
00Z TAF CYCLE
UPPER TROUGH WILL MOVE ACROSS THE TEXAS AND OKLAHOMA PANHANDLES
TONIGHT PRODUCING CONSIDERABLE MID AND HIGH LEVEL CLOUDINESS AND
USHERING IN A COLD FRONT THANKSGIVING DAY MORNING. VFR CONDITIONS ARE
EXPECTED ALONG WITH SOUTHERLY WINDS 15 TO 20 KNOTS WITH SOME HIGHER
GUSTS POSSIBLE TONIGHT...THEN WINDS SHIFTING TO THE NORTHWEST AND
NORTH 15 TO 25 KNOTS WITH HIGHER GUSTS AFTER 14Z TO 17Z THANKSGIVING
DAY. WIND SPEEDS ARE EXPECTED TO GRADUALLY DIMINISH AFTER 20Z TO 22Z
THANKSGIVING DAY TO AROUND 15 KNOTS.
SCHNEIDER
PREV DISCUSSION... /ISSUED 415 PM CST WED NOV 21 2012/
DISCUSSION...
CONTINUED DRY CONDITIONS AND PERIODIC FRONTAL PASSAGES HIGHLIGHT THE
FORECAST PERIOD.
SOUTHWESTERLY WINDS AND CLOUD COVER HAVE INCREASED TODAY IN ADVANCE
OF A SHORTWAVE TROUGH NOW EJECTING THROUGH THE AMBIENT SOUTHWESTERLY
FLOW ALOFT. WHILE MOST OF THE FORCING/ASCENT AND MEANINGFUL RAIN
CHANCES ASSOCIATED WITH THIS FEATURE WILL REMAIN WELL SOUTH OF THE
AREA...SOME ENHANCED VORTICITY/DEEPENING OF THE TROUGH HAS EMERGED THIS
AFTERNOON OVER CENTRAL NEW MEXICO. ISOLATED HIGH-BASED CONVECTION HAS
DEVELOPED NEAR ROSWELL. ALL NWP SOLUTIONS MINIMIZE PROSPECTS FOR
PRECIPITATION IN THE PANHANDLES AS THIS TRANSLATES OVER THE REGION
TONIGHT. ONLY THE RAP DEPICTS THE SMALLEST HINT OF QPF OVER THE
SOUTHWESTERN PANHANDLE. THUS WE HAVE MAINTAINED A DRY FORECAST WITH
GRIDDED POPS AT/BELOW 10 PERCENT.
A FRONT IS EXPECTED TO PUSH ACROSS THE PANHANDLES AFTER 12-15Z
THURSDAY IN WAKE OF THE PASSING SHORTWAVE TROUGH AXIS. 3-HR PRESSURE
RISES AROUND 4 MB OVER KANSAS WILL SUPPORT POST FRONTAL WINDS OF 15
TO 25 MPH...ESPECIALLY OVER THE OKLAHOMA PANHANDLE AND THE NORTHERN
TEXAS PANHANDLE. ALL INDICATIONS OF SUFFICIENT LIFT/MOISTURE TO
SUPPORT CONVECTION ALONG THE FRONT ARE DISPLACED WELL EAST AND SOUTH
OF THE REGION.
A 1035-1037 MB CONTINENTAL SURFACE HIGH WILL PUSH SOUTHWARD THROUGH
THE PLAINS IN WAKE OF THE FRONT. THIS WILL RESULT IN NOTABLY COOLER
TEMPERATURES /SOME 5 DEGREES BELOW SEASONAL AVERAGES/ BY FRIDAY. THE
COOL SURFACE RIDGE WILL TRANSLATE SOUTHEAST TOWARD THE LOWER
MISSISSIPPI VALLEY...LENDING TOWARD TEMPERATURE MODERATION OVER THE
PANHANDLES THROUGH THE WEEKEND. THIS AS LOW AMPLITUDE RIDGING OVER
THE WEST RESULTS IN MODEST NORTHWESTERLY FLOW OVER THE CENTRAL/SOUTHERN
PLAINS AND LEE TROUGHING.
ATTENTION THEN SHIFTS TOWARD A SHORTWAVE TROUGH AND ASSOCIATED FRONTAL
PASSAGE EARLY NEXT WEEK. THE INITIAL FRONTAL PASSAGE WILL OCCUR DURING
THE LATE SUNDAY/EARLY MONDAY TIMEFRAME...AND MAY RESULT IN PROBLEMATIC
TEMPERATURE FORECASTS INITIALLY. THE FRONT WILL FINALLY PUSH SOLIDLY
THROUGH BY LATE MONDAY AS THE APPROACHING SHORTWAVE TROUGH AMPLIFIES
IN NORTHWESTERLY FLOW. SOME SOLUTIONS GENERATE LIGHT QPF IN PROXIMITY
TO THE NORTHERN AND EASTERN PANHANDLES...BUT CONFIDENCE IN SUFFICIENT
FORCING/MOISTURE IS NOT HIGH AND THE CURRENT DRY FORECAST CONTINUES TO
APPEAR VALID.
FIRE WEATHER...
ONGOING ELEVATED FIRE WEATHER OVER THE WESTERN AND CENTRAL OKLAHOMA
PANHANDLE AND NORTHWESTERN TEXAS PANHANDLE WILL DIMINISH BY EARLY
EVENING. CONCERNS FOR ELEVATED CONDITIONS WILL AGAIN EXIST THURSDAY...
AS POST FRONTAL WINDS INCREASE INTO THE 15 TO 20 MPH RANGE AND AFTERNOON
HUMIDITY MINIMA DROP TOWARDS 15 PERCENT AGAIN OVER THE WESTERN OKLAHOMA
PANHANDLE AND THE NORTHWESTERN TEXAS PANHANDLE. OTHERWISE...ELEVATED
OR CRITICAL CONDITIONS ARE NOT ANTICIPATED THROUGH THE REMAINDER OF THE
PERIOD.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
11/08
AREA FORECAST DISCUSSION
NWS AMARILLO TX
518 PM CST WED NOV 21 2012
.AVIATION...
00Z TAF CYCLE
UPPER TROUGH WILL MOVE ACROSS THE TEXAS AND OKLAHOMA PANHANDLES
TONIGHT PRODUCING CONSIDERABLE MID AND HIGH LEVEL CLOUDINESS AND
USHERING IN A COLD FRONT THANKSGIVING DAY MORNING. VFR CONDITIONS ARE
EXPECTED ALONG WITH SOUTHERLY WINDS 15 TO 20 KNOTS WITH SOME HIGHER
GUSTS POSSIBLE TONIGHT...THEN WINDS SHIFTING TO THE NORTHWEST AND
NORTH 15 TO 25 KNOTS WITH HIGHER GUSTS AFTER 14Z TO 17Z THANKSGIVING
DAY. WIND SPEEDS ARE EXPECTED TO GRADUALLY DIMINISH AFTER 20Z TO 22Z
THANKSGIVING DAY TO AROUND 15 KNOTS.
SCHNEIDER
&&
.PREV DISCUSSION... /ISSUED 415 PM CST WED NOV 21 2012/
DISCUSSION...
CONTINUED DRY CONDITIONS AND PERIODIC FRONTAL PASSAGES HIGHLIGHT THE
FORECAST PERIOD.
SOUTHWESTERLY WINDS AND CLOUD COVER HAVE INCREASED TODAY IN ADVANCE
OF A SHORTWAVE TROUGH NOW EJECTING THROUGH THE AMBIENT SOUTHWESTERLY
FLOW ALOFT. WHILE MOST OF THE FORCING/ASCENT AND MEANINGFUL RAIN
CHANCES ASSOCIATED WITH THIS FEATURE WILL REMAIN WELL SOUTH OF THE
AREA...SOME ENHANCED VORTICITY/DEEPENING OF THE TROUGH HAS EMERGED THIS
AFTERNOON OVER CENTRAL NEW MEXICO. ISOLATED HIGH-BASED CONVECTION HAS
DEVELOPED NEAR ROSWELL. ALL NWP SOLUTIONS MINIMIZE PROSPECTS FOR
PRECIPITATION IN THE PANHANDLES AS THIS TRANSLATES OVER THE REGION
TONIGHT. ONLY THE RAP DEPICTS THE SMALLEST HINT OF QPF OVER THE
SOUTHWESTERN PANHANDLE. THUS WE HAVE MAINTAINED A DRY FORECAST WITH
GRIDDED POPS AT/BELOW 10 PERCENT.
A FRONT IS EXPECTED TO PUSH ACROSS THE PANHANDLES AFTER 12-15Z
THURSDAY IN WAKE OF THE PASSING SHORTWAVE TROUGH AXIS. 3-HR PRESSURE
RISES AROUND 4 MB OVER KANSAS WILL SUPPORT POST FRONTAL WINDS OF 15
TO 25 MPH...ESPECIALLY OVER THE OKLAHOMA PANHANDLE AND THE NORTHERN
TEXAS PANHANDLE. ALL INDICATIONS OF SUFFICIENT LIFT/MOISTURE TO
SUPPORT CONVECTION ALONG THE FRONT ARE DISPLACED WELL EAST AND SOUTH
OF THE REGION.
A 1035-1037 MB CONTINENTAL SURFACE HIGH WILL PUSH SOUTHWARD THROUGH
THE PLAINS IN WAKE OF THE FRONT. THIS WILL RESULT IN NOTABLY COOLER
TEMPERATURES /SOME 5 DEGREES BELOW SEASONAL AVERAGES/ BY FRIDAY. THE
COOL SURFACE RIDGE WILL TRANSLATE SOUTHEAST TOWARD THE LOWER
MISSISSIPPI VALLEY...LENDING TOWARD TEMPERATURE MODERATION OVER THE
PANHANDLES THROUGH THE WEEKEND. THIS AS LOW AMPLITUDE RIDGING OVER
THE WEST RESULTS IN MODEST NORTHWESTERLY FLOW OVER THE CENTRAL/SOUTHERN
PLAINS AND LEE TROUGHING.
ATTENTION THEN SHIFTS TOWARD A SHORTWAVE TROUGH AND ASSOCIATED FRONTAL
PASSAGE EARLY NEXT WEEK. THE INITIAL FRONTAL PASSAGE WILL OCCUR DURING
THE LATE SUNDAY/EARLY MONDAY TIMEFRAME...AND MAY RESULT IN PROBLEMATIC
TEMPERATURE FORECASTS INITIALLY. THE FRONT WILL FINALLY PUSH SOLIDLY
THROUGH BY LATE MONDAY AS THE APPROACHING SHORTWAVE TROUGH AMPLIFIES
IN NORTHWESTERLY FLOW. SOME SOLUTIONS GENERATE LIGHT QPF IN PROXIMITY
TO THE NORTHERN AND EASTERN PANHANDLES...BUT CONFIDENCE IN SUFFICIENT
FORCING/MOISTURE IS NOT HIGH AND THE CURRENT DRY FORECAST CONTINUES TO
APPEAR VALID.
FIRE WEATHER...
ONGOING ELEVATED FIRE WEATHER OVER THE WESTERN AND CENTRAL OKLAHOMA
PANHANDLE AND NORTHWESTERN TEXAS PANHANDLE WILL DIMINISH BY EARLY
EVENING. CONCERNS FOR ELEVATED CONDITIONS WILL AGAIN EXIST THURSDAY...
AS POST FRONTAL WINDS INCREASE INTO THE 15 TO 20 MPH RANGE AND AFTERNOON
HUMIDITY MINIMA DROP TOWARDS 15 PERCENT AGAIN OVER THE WESTERN OKLAHOMA
PANHANDLE AND THE NORTHWESTERN TEXAS PANHANDLE. OTHERWISE...ELEVATED
OR CRITICAL CONDITIONS ARE NOT ANTICIPATED THROUGH THE REMAINDER OF THE
PERIOD.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
11/08
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
302 PM CST TUE NOV 20 2012
.SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT
301 PM CST TUE NOV 20 2012
MAIN FORECAST CONCERN IS ON CLOUDS/FOG POTENTIAL
TONIGHT...TEMPERATURES THROUGH THE PERIOD AND RAIN CHANCES FOR
THANKSGIVING DAY.
VISIBLE SATELLITE IMAGERY AT 18Z SHOWS AN AREA OF FOG ALONG THE
MISSISSIPPI RIVER AND ACROSS SOUTHWEST WISCONSIN AND EASTERN IOWA.
THIS AREA HAS BEEN SHRINKING OVER THE PAST SEVERAL HOURS AND EXPECT
IT TO DISSIPATE BY EVENING. OTHERWISE SKIES WERE CLEAR AROUND THE AREA.
20.12Z MODELS CONTINUE TO BE IN GOOD AGREEMENT THROUGH THE PERIOD.
NAM IS THE FASTEST SOLUTION IN REGARD TO THE FRONTAL MOVEMENT ON
THANKSGIVING DAY AND WENT MORE WITH A MODEL CONSENSUS WITH ITS
MOVEMENT ACROSS THE FORECAST AREA.
IN THE NEAR TERM...PROBLEM IS ON FOG AND LOW CLOUD POTENTIAL AGAIN
TONIGHT. RAP BUFKIT SOUNDINGS SHOW MOISTURE BEING TRAPPED UNDER THE
STRENGTHENING INVERSION TONIGHT...BUT NAM WANTS TO SCOUR THINGS OUT
WITH DRIER AIR FILTERING IN FROM THE WEST. HOWEVER...FEEL RAP MAYBE
MORE ACCURATE AS GRADIENT LOOKS TO BE QUITE WEAK UNTIL LATER TONIGHT
WHEN THE WINDS PICK UP ACROSS THE WEST. FEEL WIDESPREAD FOG IS AGAIN
LIKELY...MAINLY IN AREAS ALONG AND EAST OF THE MISSISSIPPI RIVER.
ATTENTION THEN TURNS TO BUILDING UPPER RIDGE ACROSS THE AREA
WEDNESDAY. 925MB TEMPERATURES WILL WARM INTO THE LOWER TO MIDDLE
TEENS CELSIUS BY AFTERNOON AND THUS EXPECT VERY WARM TEMPERATURES.
MIXING POTENTIAL LOOKS TO BE BETWEEN 925MB AND 950MB AND USING THE
MIX DOWN TOOL RESULTS IN A 10 DEGREE DIFFERENCE BETWEEN MIXING TO
925MB AND 950MB. THE CAVEAT WILL BE LINGERING CLOUDS AND FOG
EXPECTED INTO THE MID MORNING HOURS THAT MAY PREVENT FULL WARMING.
NONE THE LESS FORECAST IS BASED ON CLOUDS/FOG DISSIPATING BY MID
MORNING AND COMBINED WITH A MILD START WILL STILL MAKE IT INTO THE
MID 50S ACROSS THE NORTH TO THE MID 60S IN THE CENTRAL AND SOUTH.
ANOTHER MILD NIGHT IS EXPECTED WEDNESDAY NIGHT WITH SOUTHERLY LOW
LEVEL FLOW CONTINUING AHEAD OF AN APPROACHING COLD FRONT. THE COLD
FRONT WILL REMAIN WEST OF THE AREA THROUGH THE OVERNIGHT HOURS.
ANOTHER MILD DAY IS EXPECTED THANKSGIVING DAY AS THE FRONTAL PASSAGE
LOOKS LIKE IT WILL OCCUR DURING THE AFTERNOON HOURS. AS MENTIONED
PREVIOUSLY...NAM IS THE FASTEST SOLUTION AND USED A MODEL CONSENSUS.
IN EITHER CASE...THE COLDER AIR LAGS BEHIND AND WILL NOT ARRIVE
UNTIL THURSDAY NIGHT. GFS CONTINUES TO BE THE ONLY MODEL THAT
GENERATES SHOWERS OVER SOUTHWEST WISCONSIN...WITH THE GEM AND ECMWF
KEEPING THE RAIN JUST SOUTH OF THE AREA. WILL CONTINUE LOWER END
PROBABILITIES ACROSS FAR SOUTHWEST WISCONSIN.
STRONG COLD ADVECTION EXPECTED BEHIND THE FRONT THURSDAY NIGHT ALONG
WITH A TIGHTENING PRESSURE GRADIENT. STRATUS LOOKS TO ADVECT
SOUTHWARD AS THE NIGHT WEARS ON...ESPECIALLY ACROSS THE NORTHERN
HALF OF THE FORECAST AREA. THESE CLOUDS WILL THEN CONTINUE INTO
FRIDAY. PRESSURE GRADIENT RATHER TIGHT FRIDAY AND LOOKS LIKE A
BLUSTERY AND COLD DAY WITH TEMPERATURES ONLY CLIMBING A FEW DEGREES
FROM THE MORNING LOWS. BETTER CHANCES FOR LIGHT SHOW/RAIN WILL BE
ACROSS THE NORTH AND WILL CONTINUE THE LOWER END PROBABILITIES IN
THESE AREAS. HIGH PRESSURE THEN BUILDS EASTWARD FROM THE PLAINS
FRIDAY NIGHT AND WITH CLEAR SKIES EXPECTED...LOWS WILL BE IN THE
TEENS TO LOWER 20S.
.LONG TERM...
301 PM CST TUE NOV 20 2012
MEDIUM RANGE MODELS DO SHOW SOME DIFFERENCES IN THIS TIME FRAME.
20.12Z ECMWF HAS BACKED OFF ON A NEGATIVELY TILTED TROUGH DEVELOPING
EARLY NEXT WEEK AND NOW HAS MAINLY A ZONAL FLOW REGIME. GFS AND
ECMWF DO DIFFER WITH SOME SUBTLE WAVES EXPECTED TO TRANSLATE THROUGH
THE FLOW FROM SUNDAY THROUGH TUESDAY. SURFACE HIGH PRESSURE WILL
DOMINATE THE PATTERN SATURDAY...BUT AFTER THAT CONFIDENCE IS RATHER
LOW IN ANY ONE SOLUTION AND THUS HAVE WENT WITH THE MODEL CONSENSUS.
TEMPERATURES LOOK TO REMAIN BELOW NORMAL THROUGH THE PERIOD...WITH
HIGHS MAINLY IN THE 30S WITH LOWS IN THE TEENS AND 20S.
&&
.AVIATION...THIS AFTERNOON THROUGH WEDNESDAY
1125 AM CST TUE NOV 20 2012
A VERY PROBLEMATIC PERIOD WITH ABUNDANT LOW LEVEL MOISTURE TRAPPED
UNDER A RATHER STRONG INVERSION NEAR 925 MB. LIGHT WINDS/LIMITED
MIXING THIS TIME OF YEAR HAVE RESULTED IN PERSISTENT IFR/LIFR DENSE
FOG 25-50 MILES EITHER SIDE OF THE MS RIVER. SFC OBS/VIS IMAGERY
SHOWING ONLY A VERY SLOW EROSION/IMPROVEMENT OF THE FOG AS OF
MID-DAY. SOME IMPROVEMENT FROM LIFR TO IFR IN THIS BAND OF LOW
CLOUDS/FOG EXPECTED THRU THE AFTERNOON. RADIATIONAL COOLING/LIGHT
WINDS UNDER THE INVERSION WILL ALLOW THE FOG TO RE-THICKEN AGAIN
TONIGHT...AT LEAST THRU THE EVENING HOURS. SFC PRESSURE GRADIENT
TIGHTENS LATER TONIGHT AND INTO WED...ALLOWING FOR BOUNDARY LAYER
MIXING UNDER THE INVERSION. THIS EXPECTED TO RESULT IN MORE IFR/LIFR
STRATUS AND 1-3SM VSBYS IN BR VS. M1/4SM IN FG IF THE WINDS WERE TO
STAY LIGHT/VARIABLE. GRADIENT CONTINUES TO TIGHTEN WED WITH WARMER/
DRIER AIR ADVECTING/MIXING IN FROM THE SOUTHWEST. GIVEN THE TIME OF
YEAR...IFR/MVFR VSBYS AND SOME IFR CIGS LIKELY TO PERSIST THRU MUCH
OF WED MORNING BEFORE CONDITIONS IMPROVE WITH DEEPER MIXING/EROSION
OF THE INVERSION FOR THE MID-DAY/AFTERNOON HOURS.
&&
.CLIMATE...
200 AM CST SUN NOV 18 2012
RECORD HIGH TEMPERATURES FOR WEDNESDAY/21ST AND THURSDAY/22ND. COOP
SITES ARE 7 AM-7 AM HIGHS...THUS 22ND HIGHS ARE 21.12Z TO 22.12Z.
LA CROSSE AND ROCHESTER ARE THE ONLY NON-COOP SITES.
FORECAST HIGH TEMPERATURES SUGGEST SOME OF THE RECORDS BELOW MAY
BE TIED OR BROKEN.
LOCATION WEDNESDAY/21ST THURSDAY/22ND
LA CROSSE WI 72/1990 59/1963
SPARTA WI 65/1990 70/1990
MEDFORD WI 59/1913 65/1990
LANCASTER WI 66/2003 66/1898
MAUSTON WI 67/2003 66/1990
ROCHESTER MN 69/1990 65/1913
AUSTIN MN 70/1990 58/1966
WINONA DAM 5A MN 60/2003 60/2001
WABASHA MN 61/1908 59/1908
CHARLES CITY IA 71/1990 62/1966
OELWEIN IA 71/1990 62/1966
DECORAH IA 71/1990 62/1908
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
301 PM CST TUE NOV 20 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RABERDING
LONG TERM...RABERDING
AVIATION.....RRS
CLIMATE......JONES/DB/AJ/BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
513 AM CST TUE NOV 20 2012
.SHORT TERM...TODAY THROUGH THANKSGIVING
513 AM CST TUE NOV 20 2012
513 AM UPDATE...EXPANDING THE ADVISORY TO SOME SOUTHWEST WISCONSIN
COUNTIES. SEE WWA SECTION BELOW. HAVE REMOVED OLMSTED AND MOWER
COUNTIES AS SOME DRIER AIR ON NORTHWEST WINDS HAS CLEARED OUT MUCH
OF THE FOG THERE. THIS DRIER AIR SHOULD KEEP MAKING ITS WAY
SOUTHEAST...SO MORE COUNTIES MAY BE ABLE TO BE REMOVED. NEEDLESS
TO SAY A RAPIDLY EVOLVING SITUATION HERE WITH THE FOG.
PREVIOUS SHORT TERM DISCUSSION AT 326 AM...
AT 3 AM...A PACIFIC COLD FRONT WAS MOVING INTO SOUTHEAST MINNESOTA
AND NORTHEAST IOWA. AHEAD OF THIS FRONT...WIDESPREAD DENSE FOG HAS
DEVELOPED ACROSS MUCH OF NORTHEAST IOWA AND PARTS OF SOUTHEAST
MINNESOTA. AS THIS FRONT MOVES THROUGH...IT HAS BEEN LESSENING THE
DEPTH OF THE FOG. THIS HAS RESULTED IN SOME IMPROVEMENT IN THE
VISIBILITIES IN THE WAKE OF THIS FRONT. NOT QUITE SURE WHAT THIS
FOG IS GOING TO DO ONCE IT MOVES INTO WESTERN WISCONSIN. WILL IT
JUST BE A DECK OF STRATUS OR WILL WE SEE RAPID DEVELOPMENT OF
DENSE FOG. DUE TO THIS UNCERTAINTY HELD OFF EXPANDING THE DENSE
FOG ADVISORY FOR NOW.
FOR TODAY EXPECT TO SEE THE LOW CLOUDS AND FOG WILL DISSIPATE THIS
MORNING. THIS WILL LEAVE AFTERNOON MAINLY SUNNY. SINCE THIS
FRONT IS A PACIFIC ONE...TEMPERATURES SHOULD ONLY BE A FEW DEGREES
COOLER THAN MONDAY.
ON WEDNESDAY...SOUTHWEST WINDS ALOFT WILL BRING VERY WARM AIR
INTO THE REGION FROM THE CENTRAL AND SOUTHERN PLAINS. 925 MB
TEMPERATURES CLIMB FROM 8C THIS AFTERNOON TO 14C BY WEDNESDAY
AFTERNOON. THE WARM AIR BEING BROUGHT ISENTOPICALLY OFF OF THE
HIGH PLAINS WILL RESULT IN THE DEVELOPMENT OF A STRONG CAP. THIS
WILL INHIBIT THE DEVELOPMENT OF ANY PRECIPITATION. HIGH
TEMPERATURES WILL BE IN THE MID AND UPPER 50S NORTH OF INTERSTATE
94 CORRIDOR /WHICH WILL BE CLOSE TO SOME RECORDS/. MEANWHILE THE
REMAINDER OF THE AREA WILL BE IN THE LOWER AND MID 60S.
ON THANKSGIVING...BOTH THE GFS AND ECMWF SUGGEST THAT A SHORT WAVE
TROUGH WILL AFFECT SOUTHWEST WISCONSIN AND NORTHEAST IOWA.
SOUNDINGS SUGGEST THAT THE AIRMASS WILL MOISTEN ENOUGH THAT THERE
COULD BE SOME ELEVATED SHOWERS MOVE THROUGH THIS AREA. DUE TO
THIS BEING A CONSISTENT SIGNAL...KEPT A LOW /20 PERCENT/
PRECIPITATION PROBABILITY IN THE FORECAST.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY
326 AM CST TUE NOV 20 2012
ON THURSDAY NIGHT AND FRIDAY...THE 20.00Z MODELS CONTINUE TO SHOW THAT A
SHORT WAVE TROUGH WILL MOVE EAST THROUGH THE AREA. THIS SYSTEM WILL
USHER IN MUCH COOLER AIR INTO THE REGION. TEMPERATURES WILL RUN
NEAR TO SLIGHTLY BELOW NORMAL FROM FRIDAY INTO THE WEEKEND. THE
MODELS ALSO SHOW THAT THERE WILL DEEP ENOUGH MOISTURE FOR A
CHANCE OF SNOW ALONG AND NORTH OF THE INTERSTATE 94 CORRIDOR.
MEANWHILE SOUTH OF THIS CORRIDOR...THE BUFKIT SOUNDINGS SHOW SOME
WEAK OMEGA IN THE DENDRITIC GROWTH REGION AND THERE IS STEEP
LAPSE RATES /AROUND 8C/KM / BETWEEN THE 950-850 MB. DUE TO
THIS...INCLUDED SOME SCATTERED FLURRIES FOR THIS AREA FROM 29.09Z
AND 29.12Z. GUSTY NORTHWEST WINDS AT 15 TO 20 KNOTS WILL PRODUCE
WIND CHILLS FROM THE TEENS TO MID 20S.
FOR EARLY NEXT WEEK AND BEYOND...UNCERTAINTY IS MUCH HIGHER THAN
AVERAGE DUE TO THE FOLLOWING REASONS...
1. MADDEN JULIAN OSCILLATION /MJO/ - SEVERAL MODELS INCLUDING
SOME RUNS OF THE ECMWF AND GFS TRY TO BRING A STRONG MJO SIGNAL
INTO THE WESTERN PACIFIC BY EARLY NEXT WEEK. HOWEVER DURING THE
PAST 3 DAYS...200 MB VELOCITY POTENTIAL ANOMALIES HAVE
DRAMATICALLY DECREASED. IT WILL INTERESTING OVER THE WEEKEND
WHETHER THIS OSCILLATION STRENGTHENS AS IT MOVES OVER 30C WATER IN
THE WESTERN PACIFIC.
2. PHASE OF THE NORTH ATLANTIC OSCILLATION /NAO/ - FOR THE PAST
WEEK THE MODELS HAVE BEEN STRUGGLING ON WHEN THE NAO WILL ONCE
AGAIN BECOME NEGATIVE. CPC/S SPAGHETTI PLOT CONTINUES TO SHOW A
WIDE RANGE OF SOLUTIONS FROM -1.5 TO 1. LOOKING AT THE 150 MB WIND
ANOMALIES AND ALSO STRATOSPHERIC TEMPERATURES...DO NOT SEE ANY
INDICATION OF A BLOCKING RIDGE DEVELOPING ANYWHERE IN THE NORTHERN
HEMISPHERE.
3. CLIMATE MODELS - BOTH THE CFS VERSION 2 AND THE NORTH
AMERICAN ENSEMBLE FORECASTING SYSTEM /NAEFS/ SHOW ABOVE- NORMAL
TEMPERATURES FOR THE DAY 8 TO 14 TIME PERIOD. AS A RESULT...ANY
COLD PERIOD SHOULD BE RATHER SHORT. THIS IS INCONSISTENT WITH SOME
OF THE MODELS WHICH SHOW THAT SHOW A PERSISTENT TROUGH OVER THE
AREA.
WITH MIXED SIGNALS ACROSS THE GLOBE...VERY CAUTIOUS OF GRABBING
ONTO ANY ONE MODEL SOLUTION...THUS...WILL KEEP PRECIPITATION
PROBABILITIES LOW BEYOND DAY 5 UNTIL THERE IS A COHERENT DAY TO
DAY SIGNAL.
&&
.AVIATION...
1035 PM CST MON NOV 19 2012
FOG IS GOING TO BE A BIGGER PLAYER IN THE FORECAST THAN FIRST
THOUGHT. MESO MODELS CONTINUE TO POINT TO A RELATIVELY MOIST
BOUNDARY LAYER UNDER AN INVERSION TONIGHT...WITH LIGHT SFC WINDS.
FOG HAS ALREADY BEGUN TO DEVELOP WEST OF A CLOUD MASS THAT SAT
ACROSS MOST OF WI...PER LATEST FOG/STRATUS SATELLITE IMAGERY. IN THE
CLEAR REGION WEST OF THERE VSBYS HAVE ALREADY FALLEN BELOW 2 MILES
IN MANY AREAS. BELIEVE VSBYS WILL DROP BELOW 1 MILE AT TIMES
OVERNIGHT. PASSING SFC FRONT SHOULD USHER IN SOME DRIER AIR BY 12Z
AT KRST...WHICH SHOULD HELP IMPROVE VSBYS. SOME NUMERICAL MODELS
SUGGEST THAT FOG...POTENTIALLY DENSE...WOULD PERSIST THROUGH 15Z AT
KRST. NOT BUYING THAT AT THIS MOMENT. A PERIOD OF IFR/LIFR LOOKS
LIKELY AT KRST...AND PROBABLE AT KLSE. CAN/T RULE OUT THAT A DENSE
FOG ADVISORY WILL BE NEEDED FOR PORTIONS OF THE REGION FOR EARLY TUE
MORNING. WITH THE FOG WILL COME SOME STRATUS...ESPECIALLY AS THE FOG
STARTS TO LIFT. RAP BUFKIT SOUNDINGS WOULD SCATTER OUT ANY CIGS
BETWEEN 15-17Z. NOT ALL IS CLEAR CUT WITH VSBYS AND CIGS OVERNIGHT
THOUGH...SO A CLOSE WATCH ON CONDITIONS WILL HAVE TO CONTINUE AND
UPDATES MADE AS NEEDED.
HIGH PRESSURE GRADUALLY BUILDS IN TUE AFTERNOON...BUT QUICKLY SLIDES
SOUTHEAST OVERNIGHT. PRESSURE GRADIENT INCREASE BEHIND THE
HIGH...AND COULD SEE SOME INCREASE IN WINDS TOWARD 12Z WED AS A
RESULT.
&&
.CLIMATE...
200 AM CST SUN NOV 18 2012
RECORD HIGH TEMPERATURES FOR WEDNESDAY/21ST AND THURSDAY/22ND. COOP
SITES ARE 7 AM-7 AM HIGHS...THUS 22ND HIGHS ARE 21.12Z TO 22.12Z.
LA CROSSE AND ROCHESTER ARE THE ONLY NON-COOP SITES.
FORECAST HIGH TEMPERATURES SUGGEST SOME OF THE RECORDS BELOW MAY
BE TIED OR BROKEN.
LOCATION WEDNESDAY/21ST THURSDAY/22ND
LA CROSSE WI 72/1990 59/1963
SPARTA WI 65/1990 70/1990
MEDFORD WI 59/1913 65/1990
LANCASTER WI 66/2003 66/1898
MAUSTON WI 67/2003 66/1990
ROCHESTER MN 69/1990 65/1913
AUSTIN MN 70/1990 58/1966
WINONA DAM 5A MN 60/2003 60/2001
WABASHA MN 61/1908 59/1908
CHARLES CITY IA 71/1990 62/1966
OELWEIN IA 71/1990 62/1966
DECORAH IA 71/1990 62/1908
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
513 AM CST TUE NOV 20 2012
WI...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR WIZ032>034-
041-042-053.
MN...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR MNZ079-088-
095-096.
IA...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR IAZ008>011-
018-019-029-030.
&&
$$
SHORT TERM...BOYNE/AJ
LONG TERM...BOYNE
AVIATION.....RIECK
CLIMATE......JONES/DB/AJ/BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
326 AM CST TUE NOV 20 2012
.SHORT TERM...TODAY THROUGH THANKSGIVING
326 AM CST TUE NOV 20 2012
AT 3 AM...A PACIFIC COLD FRONT WAS MOVING INTO SOUTHEAST MINNESOTA
AND NORTHEAST IOWA. AHEAD OF THIS FRONT...WIDESPREAD DENSE FOG HAS
DEVELOPED ACROSS MUCH OF NORTHEAST IOWA AND PARTS OF SOUTHEAST
MINNESOTA. AS THIS FRONT MOVES THROUGH...IT HAS BEEN LESSENING THE
DEPTH OF THE FOG. THIS HAS RESULTED IN SOME IMPROVEMENT IN THE
VISIBILITIES IN THE WAKE OF THIS FRONT. NOT QUITE SURE WHAT THIS
FOG IS GOING TO DO ONCE IT MOVES INTO WESTERN WISCONSIN. WILL IT
JUST BE A DECK OF STRATUS OR WILL WE SEE RAPID DEVELOPMENT OF
DENSE FOG. DUE TO THIS UNCERTAINTY HELD OFF EXPANDING THE DENSE
FOG ADVISORY FOR NOW.
FOR TODAY EXPECT TO SEE THE LOW CLOUDS AND FOG WILL DISSIPATE THIS
MORNING. THIS WILL LEAVE AFTERNOON MAINLY SUNNY. SINCE THIS
FRONT IS A PACIFIC ONE...TEMPERATURES SHOULD ONLY BE A FEW DEGREES
COOLER THAN MONDAY.
ON WEDNESDAY...SOUTHWEST WINDS ALOFT WILL BRING VERY WARM AIR
INTO THE REGION FROM THE CENTRAL AND SOUTHERN PLAINS. 925 MB
TEMPERATURES CLIMB FROM 8C THIS AFTERNOON TO 14C BY WEDNESDAY
AFTERNOON. THE WARM AIR BEING BROUGHT ISENTOPICALLY OFF OF THE
HIGH PLAINS WILL RESULT IN THE DEVELOPMENT OF A STRONG CAP. THIS
WILL INHIBIT THE DEVELOPMENT OF ANY PRECIPITATION. HIGH
TEMPERATURES WILL BE IN THE MID AND UPPER 50S NORTH OF INTERSTATE
94 CORRIDOR /WHICH WILL BE CLOSE TO SOME RECORDS/. MEANWHILE THE
REMAINDER OF THE AREA WILL BE IN THE LOWER AND MID 60S.
ON THANKSGIVING...BOTH THE GFS AND ECMWF SUGGEST THAT A SHORT WAVE
TROUGH WILL AFFECT SOUTHWEST WISCONSIN AND NORTHEAST IOWA.
SOUNDINGS SUGGEST THAT THE AIRMASS WILL MOISTEN ENOUGH THAT THERE
COULD BE SOME ELEVATED SHOWERS MOVE THROUGH THIS AREA. DUE TO
THIS BEING A CONSISTENT SIGNAL...KEPT A LOW /20 PERCENT/
PRECIPITATION PROBABILITY IN THE FORECAST.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY
326 AM CST TUE NOV 20 2012
ON THURSDAY NIGHT AND FRIDAY...THE 20.00Z MODELS CONTINUE TO SHOW THAT A
SHORT WAVE TROUGH WILL MOVE EAST THROUGH THE AREA. THIS SYSTEM WILL
USHER IN MUCH COOLER AIR INTO THE REGION. TEMPERATURES WILL RUN
NEAR TO SLIGHTLY BELOW NORMAL FROM FRIDAY INTO THE WEEKEND. THE
MODELS ALSO SHOW THAT THERE WILL DEEP ENOUGH MOISTURE FOR A
CHANCE OF SNOW ALONG AND NORTH OF THE INTERSTATE 94 CORRIDOR.
MEANWHILE SOUTH OF THIS CORRIDOR...THE BUFKIT SOUNDINGS SHOW SOME
WEAK OMEGA IN THE DENDRITIC GROWTH REGION AND THERE IS STEEP
LAPSE RATES /AROUND 8C/KM / BETWEEN THE 950-850 MB. DUE TO
THIS...INCLUDED SOME SCATTERED FLURRIES FOR THIS AREA FROM 29.09Z
AND 29.12Z. GUSTY NORTHWEST WINDS AT 15 TO 20 KNOTS WILL PRODUCE
WIND CHILLS FROM THE TEENS TO MID 20S.
FOR EARLY NEXT WEEK AND BEYOND...UNCERTAINTY IS MUCH HIGHER THAN
AVERAGE DUE TO THE FOLLOWING REASONS...
1. MADDEN JULIAN OSCILLATION /MJO/ - SEVERAL MODELS INCLUDING
SOME RUNS OF THE ECMWF AND GFS TRY TO BRING A STRONG MJO SIGNAL
INTO THE WESTERN PACIFIC BY EARLY NEXT WEEK. HOWEVER DURING THE
PAST 3 DAYS...200 MB VELOCITY POTENTIAL ANOMALIES HAVE
DRAMATICALLY DECREASED. IT WILL INTERESTING OVER THE WEEKEND
WHETHER THIS OSCILLATION STRENGTHENS AS IT MOVES OVER 30C WATER IN
THE WESTERN PACIFIC.
2. PHASE OF THE NORTH ATLANTIC OSCILLATION /NAO/ - FOR THE PAST
WEEK THE MODELS HAVE BEEN STRUGGLING ON WHEN THE NAO WILL ONCE
AGAIN BECOME NEGATIVE. CPC/S SPAGHETTI PLOT CONTINUES TO SHOW A
WIDE RANGE OF SOLUTIONS FROM -1.5 TO 1. LOOKING AT THE 150 MB WIND
ANOMALIES AND ALSO STRATOSPHERIC TEMPERATURES...DO NOT SEE ANY
INDICATION OF A BLOCKING RIDGE DEVELOPING ANYWHERE IN THE NORTHERN
HEMISPHERE.
3. CLIMATE MODELS - BOTH THE CFS VERSION 2 AND THE NORTH
AMERICAN ENSEMBLE FORECASTING SYSTEM /NAEFS/ SHOW ABOVE- NORMAL
TEMPERATURES FOR THE DAY 8 TO 14 TIME PERIOD. AS A RESULT...ANY
COLD PERIOD SHOULD BE RATHER SHORT. THIS IS INCONSISTENT WITH SOME
OF THE MODELS WHICH SHOW THAT SHOW A PERSISTENT TROUGH OVER THE
AREA.
WITH MIXED SIGNALS ACROSS THE GLOBE...VERY CAUTIOUS OF GRABBING
ONTO ANY ONE MODEL SOLUTION...THUS...WILL KEEP PRECIPITATION
PROBABILITIES LOW BEYOND DAY 5 UNTIL THERE IS A COHERENT DAY TO
DAY SIGNAL.
&&
.AVIATION...
1035 PM CST MON NOV 19 2012
FOG IS GOING TO BE A BIGGER PLAYER IN THE FORECAST THAN FIRST
THOUGHT. MESO MODELS CONTINUE TO POINT TO A RELATIVELY MOIST
BOUNDARY LAYER UNDER AN INVERSION TONIGHT...WITH LIGHT SFC WINDS.
FOG HAS ALREADY BEGUN TO DEVELOP WEST OF A CLOUD MASS THAT SAT
ACROSS MOST OF WI...PER LATEST FOG/STRATUS SATELLITE IMAGERY. IN THE
CLEAR REGION WEST OF THERE VSBYS HAVE ALREADY FALLEN BELOW 2 MILES
IN MANY AREAS. BELIEVE VSBYS WILL DROP BELOW 1 MILE AT TIMES
OVERNIGHT. PASSING SFC FRONT SHOULD USHER IN SOME DRIER AIR BY 12Z
AT KRST...WHICH SHOULD HELP IMPROVE VSBYS. SOME NUMERICAL MODELS
SUGGEST THAT FOG...POTENTIALLY DENSE...WOULD PERSIST THROUGH 15Z AT
KRST. NOT BUYING THAT AT THIS MOMENT. A PERIOD OF IFR/LIFR LOOKS
LIKELY AT KRST...AND PROBABLE AT KLSE. CAN/T RULE OUT THAT A DENSE
FOG ADVISORY WILL BE NEEDED FOR PORTIONS OF THE REGION FOR EARLY TUE
MORNING. WITH THE FOG WILL COME SOME STRATUS...ESPECIALLY AS THE FOG
STARTS TO LIFT. RAP BUFKIT SOUNDINGS WOULD SCATTER OUT ANY CIGS
BETWEEN 15-17Z. NOT ALL IS CLEAR CUT WITH VSBYS AND CIGS OVERNIGHT
THOUGH...SO A CLOSE WATCH ON CONDITIONS WILL HAVE TO CONTINUE AND
UPDATES MADE AS NEEDED.
HIGH PRESSURE GRADUALLY BUILDS IN TUE AFTERNOON...BUT QUICKLY SLIDES
SOUTHEAST OVERNIGHT. PRESSURE GRADIENT INCREASE BEHIND THE
HIGH...AND COULD SEE SOME INCREASE IN WINDS TOWARD 12Z WED AS A
RESULT.
&&
.CLIMATE...
200 AM CST SUN NOV 18 2012
RECORD HIGH TEMPERATURES FOR WEDNESDAY/21ST AND THURSDAY/22ND. COOP
SITES ARE 7 AM-7 AM HIGHS...THUS 22ND HIGHS ARE 21.12Z TO 22.12Z.
LA CROSSE AND ROCHESTER ARE THE ONLY NON-COOP SITES.
FORECAST HIGH TEMPERATURES SUGGEST SOME OF THE RECORDS BELOW MAY
BE TIED OR BROKEN.
LOCATION WEDNESDAY/21ST THURSDAY/22ND
LA CROSSE WI 72/1990 59/1963
SPARTA WI 65/1990 70/1990
MEDFORD WI 59/1913 65/1990
LANCASTER WI 66/2003 66/1898
MAUSTON WI 67/2003 66/1990
ROCHESTER MN 69/1990 65/1913
AUSTIN MN 70/1990 58/1966
WINONA DAM 5A MN 60/2003 60/2001
WABASHA MN 61/1908 59/1908
CHARLES CITY IA 71/1990 62/1966
OELWEIN IA 71/1990 62/1966
DECORAH IA 71/1990 62/1908
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
117 AM CST TUE NOV 20 2012
WI...NONE.
MN...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR MNZ079-087-
088-094>096.
IA...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR IAZ008>011-
018-019-029-030.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION.....RIECK
CLIMATE......JONES/DB/AJ/BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
227 AM CST TUE NOV 20 2012
.SHORT TERM...THIS MORNING
227 AM CST TUE NOV 20 2012
THE DENSE FOG THAT FORMED NEAR MIDNIGHT OVER WESTERN PORTIONS OF
SOUTHEAST MINNESOTA AND NORTHEAST IOWA HAS BEEN SPREADING
WESTWARD. AS A RESULT...HAVE EXPANDED THE ADVISORY TO INCLUDE THE
COUNTIES BORDERING THE MISSISSIPPI RIVER. WILL CONTINUE TO WATCH
SATELLITE AND OBSERVATIONAL TRENDS...BUT THERE IS CONCERN THAT
SOME WISCONSIN COUNTIES MAY EVENTUALLY BE NEEDED IN THE ADVISORY
TOO. WILL EVALUATE THE NEED FOR FURTHER EXPANSION DURING THE NEXT
HOUR.
ALSO...THE LAST FEW HRRR RUNS WITH THE VISIBILITY PROGS SUGGEST
THIS FOG MAY TAKE LONGER TO DISSIPATE THAN PREVIOUSLY EXPECTED AT
MIDNIGHT. INITIAL THOUGHT WAS THAT THIS COLD FRONT COMING THROUGH
SOUTHEAST MINNESOTA AND NORTHEAST IOWA...NOTED BY WEST WINDS AT
ROCHESTER...DODGE CENTER AND PRESTON...WOULD HELP CLEAR UP THE
FOG. THIS HAS OCCURRED AT DODGE CENTER AND AS WELL FARTHER SOUTH
AT MASON CITY IN IOWA. HOWEVER...IT APPEARS IT IS TAKING AWHILE AT
AUSTIN TO DO SO. THUS...THINKING THE FOG MAY BE DEEPER AND MORE
RESILIENT TO CLEARING. PLUS...POST FRONTAL...TEMPERATURES AND
DEWPOINTS DO NOT DROP ALL THAT MUCH. YOU HAVE TO GO BACK INTO
SOUTHWEST MINNESOTA TO GET DEWPOINTS BELOW FREEZING. HRRR
VISIBILITY PROGS SUGGEST THE FOG COULD STICK AROUND UNTIL 16Z OR
SO. AS A RESULT...HAVE PLAYED THE PESSIMISTIC ROUTE AND EXTENDED
THE ADVISORY TO 16Z.
.LONG TERM...
250 PM CST MON NOV 19 2012
SYSTEM DEPARTS ON FRIDAY...WITH CYCLONIC FLOW ACROSS THE AREA.
TEMPERATURES WILL BE BELOW NORMAL WITH HIGHS MAINLY IN THE 30S. MAIN
PRECIPITATION CHANCE WILL BE ACROSS THE FAR NORTH.
OTHERWISE...REMAINDER OF THE PERIOD WILL BE DOMINATED BY SEASONAL TO
BELOW NORMAL TEMPERATURES. BEST CHANCE FOR ANY PRECIPITATION LOOKS
BE ON MONDAY...BUT MODELS SHOWING SOME DIFFERENCES WITH A DEVELOPING
TROUGH ACROSS THE CENTRAL CONUS. 19.12Z ECMWF SHOWS THIS FEATURE
WITH CYCLOGENESIS OCCURRING...WHILE THE GFS KEEPS FLOW MORE ZONAL.
IF THE ECMWF DOES VERIFY WILL HAVE TO WATCH THIS SYSTEM FOR PERIODS
BEYOND MONDAY.
&&
.AVIATION...
1035 PM CST MON NOV 19 2012
FOG IS GOING TO BE A BIGGER PLAYER IN THE FORECAST THAN FIRST
THOUGHT. MESO MODELS CONTINUE TO POINT TO A RELATIVELY MOIST
BOUNDARY LAYER UNDER AN INVERSION TONIGHT...WITH LIGHT SFC WINDS.
FOG HAS ALREADY BEGUN TO DEVELOP WEST OF A CLOUD MASS THAT SAT
ACROSS MOST OF WI...PER LATEST FOG/STRATUS SATELLITE IMAGERY. IN THE
CLEAR REGION WEST OF THERE VSBYS HAVE ALREADY FALLEN BELOW 2 MILES
IN MANY AREAS. BELIEVE VSBYS WILL DROP BELOW 1 MILE AT TIMES
OVERNIGHT. PASSING SFC FRONT SHOULD USHER IN SOME DRIER AIR BY 12Z
AT KRST...WHICH SHOULD HELP IMPROVE VSBYS. SOME NUMERICAL MODELS
SUGGEST THAT FOG...POTENTIALLY DENSE...WOULD PERSIST THROUGH 15Z AT
KRST. NOT BUYING THAT AT THIS MOMENT. A PERIOD OF IFR/LIFR LOOKS
LIKELY AT KRST...AND PROBABLE AT KLSE. CAN/T RULE OUT THAT A DENSE
FOG ADVISORY WILL BE NEEDED FOR PORTIONS OF THE REGION FOR EARLY TUE
MORNING. WITH THE FOG WILL COME SOME STRATUS...ESPECIALLY AS THE FOG
STARTS TO LIFT. RAP BUFKIT SOUNDINGS WOULD SCATTER OUT ANY CIGS
BETWEEN 15-17Z. NOT ALL IS CLEAR CUT WITH VSBYS AND CIGS OVERNIGHT
THOUGH...SO A CLOSE WATCH ON CONDITIONS WILL HAVE TO CONTINUE AND
UPDATES MADE AS NEEDED.
HIGH PRESSURE GRADUALLY BUILDS IN TUE AFTERNOON...BUT QUICKLY SLIDES
SOUTHEAST OVERNIGHT. PRESSURE GRADIENT INCREASE BEHIND THE
HIGH...AND COULD SEE SOME INCREASE IN WINDS TOWARD 12Z WED AS A
RESULT.
&&
.CLIMATE...
200 AM CST SUN NOV 18 2012
RECORD HIGH TEMPERATURES FOR WEDNESDAY/21ST AND THURSDAY/22ND. COOP
SITES ARE 6AM-6AM HIGHS...THUS 22ND HIGHS ARE 21.12Z TO 22.12Z. LA
CROSSE AND ROCHESTER ARE ONLY NON-COOP SITES.
FORECAST HIGH TEMPERATURES SUGGEST SOME OF THE RECORDS BELOW MAY
BE TIED OR BROKEN.
LOCATION WEDNESDAY/21ST THURSDAY/22ND
LA CROSSE WI 72/1990 59/1963
SPARTA WI 65/1990 70/1990
MEDFORD WI 59/1913 65/1990
LANCASTER WI 66/2003 66/1898
MAUSTON WI 67/2003 66/1990
ROCHESTER MN 69/1990 65/1913
AUSTIN MN 70/1990 58/1966
WINONA DAM 5A MN 60/2003 60/2001
WABASHA MN 61/1908 59/1908
CHARLES CITY IA 71/1990 62/1966
OELWEIN IA 71/1990 62/1966
DECORAH IA 71/1990 62/1908
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
227 AM CST TUE NOV 20 2012
WI...NONE.
MN...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR MNZ079-087-
088-094>096.
IA...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR IAZ008>011-
018-019-029-030.
&&
$$
SHORT TERM...AJ
LONG TERM....RABERDING
AVIATION.....RIECK
CLIMATE......JONES/DB/AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1035 PM CST MON NOV 19 2012
.SHORT TERM...
920 PM CST MON NOV 19 2012
QUICK UPDATE TO ADD FOG MENTION TO THE FORECAST FOR TONIGHT.
THIS MORNING/S RAINS...WHILE ONLY MINIMAL IN AMOUNTS...DID HELP ADD
SOME MOISTURE TO THE BOUNDARY LAYER. SFC WINDS ARE BECOMING LIGHT
AND SOME FUZZ IS STARTING TO DEVELOP OVER PARTS OF IOWA...JUST WEST
OF THE CLOUD EDGE. BUFKIT SOUNDINGS SUGGEST THAT THE LOW LEVEL
MOISTURE WILL REMAIN IN PLACE OVERNIGHT...WITH THE INVERSION
TRAPPING IT. SOME LOW STRATUS/FOG WOULD BE THE RESULT. FRONT IS
APPROACHING...BUT LIKELY WON/T CLEAR FORECAST AREA UNTIL WELL AFTER
12Z. THE LIGHT WINDS AREN/T PARTICULAR DEEP THOUGH...INCREASING TO
10 KTS OR SO WITHIN A FEW HUNDRED FEET. STILL...ENOUGH FAVORABLE
VARIABLES FOR FOG FORMATION THAT HAVE ADDED PATCHY-AREAS OF FOG TO
THE FORECAST FOR TONIGHT. ALL SAID...CONDITIONS WILL HAVE TO BE
MONITORED THROUGH THE OVERNIGHT HOURS. IF THE FRONT SLOWS UP...CAN/T
RULE OUT THE POSSIBILITY OF HEADLINES FOR DENSE FOG...MOSTLY WEST OF
THE CURRENT CLOUD SHIELD OVER WI.
.LONG TERM...
250 PM CST MON NOV 19 2012
SYSTEM DEPARTS ON FRIDAY...WITH CYCLONIC FLOW ACROSS THE AREA.
TEMPERATURES WILL BE BELOW NORMAL WITH HIGHS MAINLY IN THE 30S. MAIN
PRECIPITATION CHANCE WILL BE ACROSS THE FAR NORTH.
OTHERWISE...REMAINDER OF THE PERIOD WILL BE DOMINATED BY SEASONAL TO
BELOW NORMAL TEMPERATURES. BEST CHANCE FOR ANY PRECIPITATION LOOKS
BE ON MONDAY...BUT MODELS SHOWING SOME DIFFERENCES WITH A DEVELOPING
TROUGH ACROSS THE CENTRAL CONUS. 19.12Z ECMWF SHOWS THIS FEATURE
WITH CYCLOGENESIS OCCURRING...WHILE THE GFS KEEPS FLOW MORE ZONAL.
IF THE ECMWF DOES VERIFY WILL HAVE TO WATCH THIS SYSTEM FOR PERIODS
BEYOND MONDAY.
&&
.AVIATION...
1035 PM CST MON NOV 19 2012
FOG IS GOING TO BE A BIGGER PLAYER IN THE FORECAST THAN FIRST
THOUGHT. MESO MODELS CONTINUE TO POINT TO A RELATIVELY MOIST
BOUNDARY LAYER UNDER AN INVERSION TONIGHT...WITH LIGHT SFC WINDS.
FOG HAS ALREADY BEGUN TO DEVELOP WEST OF A CLOUD MASS THAT SAT
ACROSS MOST OF WI...PER LATEST FOG/STRATUS SATELLITE IMAGERY. IN THE
CLEAR REGION WEST OF THERE VSBYS HAVE ALREADY FALLEN BELOW 2 MILES
IN MANY AREAS. BELIEVE VSBYS WILL DROP BELOW 1 MILE AT TIMES
OVERNIGHT. PASSING SFC FRONT SHOULD USHER IN SOME DRIER AIR BY 12Z
AT KRST...WHICH SHOULD HELP IMPROVE VSBYS. SOME NUMERICAL MODELS
SUGGEST THAT FOG...POTENTIALLY DENSE...WOULD PERSIST THROUGH 15Z AT
KRST. NOT BUYING THAT AT THIS MOMENT. A PERIOD OF IFR/LIFR LOOKS
LIKELY AT KRST...AND PROBABLE AT KLSE. CAN/T RULE OUT THAT A DENSE
FOG ADVISORY WILL BE NEEDED FOR PORTIONS OF THE REGION FOR EARLY TUE
MORNING. WITH THE FOG WILL COME SOME STRATUS...ESPECIALLY AS THE FOG
STARTS TO LIFT. RAP BUFKIT SOUNDINGS WOULD SCATTER OUT ANY CIGS
BETWEEN 15-17Z. NOT ALL IS CLEAR CUT WITH VSBYS AND CIGS OVERNIGHT
THOUGH...SO A CLOSE WATCH ON CONDITIONS WILL HAVE TO CONTINUE AND
UPDATES MADE AS NEEDED.
HIGH PRESSURE GRADUALLY BUILDS IN TUE AFTERNOON...BUT QUICKLY SLIDES
SOUTHEAST OVERNIGHT. PRESSURE GRADIENT INCREASE BEHIND THE
HIGH...AND COULD SEE SOME INCREASE IN WINDS TOWARD 12Z WED AS A
RESULT.
&&
.CLIMATE...
200 AM CST SUN NOV 18 2012
RECORD HIGH TEMPERATURES FOR WEDNESDAY/21ST AND THURSDAY/22ND. COOP
SITES ARE 6AM-6AM HIGHS...THUS 22ND HIGHS ARE 21.12Z TO 22.12Z. LA
CROSSE AND ROCHESTER ARE ONLY NON-COOP SITES.
FORECAST HIGH TEMPERATURES SUGGEST SOME OF THE RECORDS BELOW MAY
BE TIED OR BROKEN.
LOCATION WEDNESDAY/21ST THURSDAY/22ND
LA CROSSE WI 72/1990 59/1963
SPARTA WI 65/1990 70/1990
MEDFORD WI 59/1913 65/1990
LANCASTER WI 66/2003 66/1898
MAUSTON WI 67/2003 66/1990
ROCHESTER MN 69/1990 65/1913
AUSTIN MN 70/1990 58/1966
WINONA DAM 5A MN 60/2003 60/2001
WABASHA MN 61/1908 59/1908
CHARLES CITY IA 71/1990 62/1966
OELWEIN IA 71/1990 62/1966
DECORAH IA 71/1990 62/1908
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
250 PM CST MON NOV 19 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK
LONG TERM....RABERDING
AVIATION.....RIECK
CLIMATE......JONES/DB/AJ
AREA FORECAST DISCUSSION
NWS DES MOINES IA
328 AM CST THU NOV 22 2012
.SHORT TERM /TODAY/...
MAIN CONCERN TODAY WILL BE THE WIND FOLLOWING THE FRONT BETWEEN
MID TO LATE AFTERNOON HOURS ACROSS THE NORTH. GUIDANCE AND BUFR
SOUNDINGS STILL SUGGEST SUSTAINED WINDS NEAR 30 MPH IN THE
ADVISORY AREA WITH GUSTS TO NEAR 40 TO 45 MPH BY MID AFTERNOON.
THE PEAK CONDITIONS ARE ONLY EXPECTED TO LAST ABOUT 2 TO 3 HOURS
BETWEEN 2 AND 5 PM AND AS SUN SETS...EXPECT THAT WIND GUSTS WILL
DROP OFF RATHER QUICKLY. ANOTHER WARM DAY IS EXPECTED FOR
THANKSGIVING WITH SOUTH WINDS AHEAD OF THE ADVANCING COLD FRONT.
HIGHS WILL REACH THE 60S OVER MUCH OF THE SOUTHEAST WHILE THE
NORTHWEST WILL BEGIN TO SEE HIGHS RETREATING INTO THE 50S FOR THE
DAY. BY 12Z FRONT WILL REACH FAR NW CORNER WITH FRONT NEARLY
BISECTING THE REGION BY 18Z. FRONT WILL BE THROUGH THE REGION BY
LATE AFTERNOON WITH FALLING TEMPERATURES BEHIND THE SYSTEM.
MOISTURE IS STILL LACKING WITH THE SYSTEM AND WILL CONTINUE ONLY
SLIGHT CHANCES FOR RAIN IN THE FAR SOUTHEAST FOR EARLY AFTERNOON
HOURS. REMAINDER OF THE AREA WILL BE RAIN FREE.
.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
MAIN FORECAST CONCERN FOR BEGINNING OF EXTENDED WILL BE WINDS
TONIGHT AND TEMPERATURES. FRONT WILL CONTINUE TO PUSH ACROSS THE
FAR SE OF CWA OVERNIGHT TONIGHT...WITH MUCH COLDER TEMPERATURES
AND STRONG WINDS BEHIND THE FRONT. HAVE KEPT WINDS UP OVERNIGHT
WITH STRONG PUSH OF SUBSIDENCE BEHIND FRONT AND CAA. WITH STRONG
WINDS WILL KEEP WIND ADVISORY THROUGH THE OVERNIGHT HOURS ACROSS
THE NORTH. AS LOW PULLS EASTWARD...WINDS WILL RELAX A BIT FOR
FRIDAY AFTERNOON...BUT COLD CANADIAN AIR WILL CONTINUE TO STREAM
OVER REGION...WITH HIGHS SLIGHTLY BELOW NORMAL. BROAD UPPER LEVEL
RIDGE WILL REMAIN OVER PLAINS FOR THE WEEKEND...WITH SURFACE HIGH
PRESSURE PUSHING SE. HAVE DROPPED TEMPERATURES A FEW DEGREES
FRIDAY NIGHT AS CONDITIONS LOOK RIGHT FOR A GOOD RADIATIONAL
COOLING NIGHT WITH LIGHT WINDS AND CLEAR SKIES AND CENTER OF HIGH
PASSING WEST OF CWA. WAA WILL THEN SET IN FOR SATURDAY AND SUNDAY
AND SOUTHERLY FLOW WILL RETURN WITH TEMPERATURES WARMING SLIGHTLY
FOR THE END OF THE WEEKEND AHEAD OF ANOTHER FRONTAL BOUNDARY.
ANOTHER WEEK FRONTAL BOUNDARY WILL PUSH SOUTH ACROSS IOWA FOR LATE
SUNDAY...WITH LIMITED MOISTURE...HAVE OPTED TO KEEP CONDITIONS DRY
FOR SUNDAY AND SUNDAY NIGHT...THOUGH CANNOT RULE OUT LIGHT
RAIN...DO NOT HAVE ENOUGH CONFIDENCE TO INCLUDE MENTION ATTM.
SYSTEM BECOME MUDDLED WITH LITTLE MODEL AGREEMENT. ECMWF CONTINUES
TO PUSH FRONT SOUTH...WITH GEM AND GFS PULLING AN AREA OF LOW
PRESSURE NE ACROSS THE AREA. HAVE CONTINUED TO TREND TOWARD THE
WETTER GEM/GFS SOLUTION WITH ECMWF/S DRY SOLUTION STILL AN
OUTLIER. SYSTEM WILL QUICKLY PULL EASTWARD WITH PRECIP CHANCES
ENDING BY TUESDAY NIGHT. WITH COOLER TEMPERATURES BEHIND FRONT
COULD SEE RAIN/SNOW MIX CHANGING OVER TO SNOW MONDAY NIGHT INTO
TUESDAY. HOWEVER ACCUMULATIONS LOOK TO BE MINIMAL ATTM. AS UPPER
LEVEL NORTHWEST FLOW RETURNS FOR REMAINDER OF THE PERIOD...ANOTHER
FAST MOVING SYSTEM IS EXPECTED TO PUSH ACROSS IOWA FOR LATE IN THE
PERIOD. HOWEVER...HAVE OPTED TO KEEP CONDITIONS DRY FOR NOW GIVEN
DIFFICULTY IN TIMING SUCH QUICK SYSTEM SO FAR OUT.
&&
.AVIATION...22/06Z
PRIMARY CONCERN REMAINS WINDS THROUGH THE PERIOD. SFC WINDS WILL
REMAIN STEADY FROM THE SOUTH TONIGHT...BUT EXPECT LLWS TO PERSIST AT
KDSM/KALO/KOTM WITH LATEST RAP STILL SHOWING 500M AGL WINDS /1600
FT/ AROUND 50KTS. HAVE REMOVED LLWS AT KFOD/KMCW HOWEVER WHERE
WINDS ARE ALREADY GUSTING INTO THE 20S. LLWS SHOULD END BY MORNING
WITH COLD FRONT REACHING NWRN IA BY 12Z. WINDS WILL THEN BECOME
GUSTY BEHIND MIDDAY AND AFTERNOON COLD FRONTAL PASSAGE...GENERALLY
25-30KTS BUT A FEW PERIODS OF HIGHER GUSTS ARE ALSO POSSIBLE. GUSTY
WINDS WILL CONTINUE BEYOND THE VALID PERIOD AND MAY EVEN BE STRONGER
THU NIGHT INTO EARLY FRI.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM NOON TODAY TO 6 AM CST FRIDAY FOR CALHOUN-
CERRO GORDO-EMMET-HANCOCK-HUMBOLDT-KOSSUTH-PALO ALTO-POCAHONTAS-
SAC-WEBSTER-WINNEBAGO-WORTH-WRIGHT.
&&
$$
SHORT TERM...REV
LONG TERM...AWB
AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1127 PM CST WED NOV 21 2012
.SHORT TERM /TONIGHT/...
FAIRLY TIGHT PRESSURE GRADIENT WILL CONTINUE
TO PROVIDE GUSTY SOUTH WINDS THROUGH THE OVERNIGHT HOURS AS A
SURFACE LOW AND COLD FRONT APPROACH THE STATE. THE SURFACE LOW LOOKS
TO BE CENTERED OVER NORTHERN MN BY AROUND 12Z AND COLD FRONT WILL BE
CLOSE TO WESTERN IOWA. WENT AT OR SLIGHTLY ABOVE GUIDANCE FOR
OVERNIGHT LOWS TONIGHT...NAM BEING THE COLDEST COMPARED TO THE
ECMWF/GFS.
.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
THURSDAY WILL BEGIN QUITE MILD WHICH WILL CONTINUE THROUGH NOON. A
SHORT WAVE LIFTING THROUGH THE WEAKENING SOUTHWEST FLOW COULD BRING
A FEW CLOUDS AND LIGHTS SHOWERS TO THE SOUTHEAST WHICH COULD TEMPER
TEMPERATURES A BIT. A COLD FRONT WILL ENTER THE NORTHWEST AREA BY
LATE MORNING THEN MOVE ACROSS THE REMAINDER OF CENTRAL IOWA THE
REMAINDER OF THE DAY. TEMPERATURES WILL BE STEADY OR SLIGHTLY RISING
WITH THE INITIAL FROPA DUE TO INCREASED MIXING BEFORE FALLING. THE
MIXING WILL ALSO INCREASE THE WINDS THROUGH THE AFTERNOON. THE COLD
ADVECTION WILL PROMOTE EFFICIENT MOMENTUM TRANSFER OF MIXED LAYER
WINDS TO THE SURFACE. THIS WILL PUSH WINDS TO WIND ADVISORY CRITERIA
OVER NORTHERN IOWA BY MID THURSDAY AFTERNOON. THE WINDS WILL
DIMINISH A BIT INTO THE EVENING BEFORE ANOTHER SURGE OF COLD
ADVECTION DROPS SOUTH OUT OF MINNESOTA LATE EVENING AND THROUGH THE
REMAINDER OF THE NIGHT. THIS SURGE OF COLD ADVECTION WILL INCREASE
LOW LEVEL MIXING ONCE AGAIN THOUGH MIXED LAYER WINDS WILL BE HIGHER
THAN THE AFTERNOON. SHOULD REACH WIND ADVISORY CRITERIA AGAIN
ESPECIALLY OVER NORTHERN IOWA. HAVE ISSUED A WIND ADVISORY FOR
PORTIONS OF THE NORTH FOR THURSDAY AFTERNOON AND NIGHT TO COVER
THESE EVENTS WHICH WILL IMPACT HOLIDAY TRAVEL.
FRIDAY WILL BE A COLD AND BLUSTERY DAY WITH BREEZY NORTHWEST WINDS
AND TEMPERATURES IN THE 30S. HIGH PRESSURE WILL SETTLE IN FRIDAY
NIGHT WITH TEMPERATURES FALLING INTO THE TEENS MOST AREAS. SOUTHERLY
WINDS WILL DEVELOP ON SATURDAY HOWEVER A STEEP LOW LEVEL INVERSION
AND MID LEVEL THETA-E ADVECTION INDUCED CLOUDS WILL LIMIT MODERATION
POTENTIAL. SUNDAY WILL BE WARMER AND CLOSER TO CLIMATOLOGY. A SHORT
WAVE DROPPING THROUGH THE NORTHWEST FLOW EARLY NEXT WEEK WILL DRIVE
A LONG WAVE TROUGH INTO THE REGION ALONG WITH ANOTHER COLD FRONT
PUSHING TEMPERATURES BACK INTO THE 30S. THE PRIMARY PRECIPITATION
EVENT AND LOW PRESSURE SYSTEM SHOULD TRACK SOUTHEAST OF IOWA AND
INTO THE OHIO VALLEY. LIGHT RAIN OR SNOW IS POSSIBLE BUT LITTLE TO
NO ACCUMULATION OF THE WHITE STUFF IS EXPECTED.
&&
.AVIATION...22/06Z
PRIMARY CONCERN REMAINS WINDS THROUGH THE PERIOD. SFC WINDS WILL
REMAIN STEADY FROM THE SOUTH TONIGHT...BUT EXPECT LLWS TO PERSIST AT
KDSM/KALO/KOTM WITH LATEST RAP STILL SHOWING 500M AGL WINDS /1600
FT/ AROUND 50KTS. HAVE REMOVED LLWS AT KFOD/KMCW HOWEVER WHERE
WINDS ARE ALREADY GUSTING INTO THE 20S. LLWS SHOULD END BY MORNING
WITH COLD FRONT REACHING NWRN IA BY 12Z. WINDS WILL THEN BECOME
GUSTY BEHIND MIDDAY AND AFTERNOON COLD FRONTAL PASSAGE...GENERALLY
25-30KTS BUT A FEW PERIODS OF HIGHER GUSTS ARE ALSO POSSIBLE. GUSTY
WINDS WILL CONTINUE BEYOND THE VALID PERIOD AND MAY EVEN BE STRONGER
THU NIGHT INTO EARLY FRI.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY THURSDAY AFTERNOON THROUGH THURSDAY NIGHT
EMMET-KOSSUTH-WINNEBAGO-WORTH-PALO ALTO-HANCOCK-CERRO GORDO-
POCAHONTAS-HUMBOLDT-WRIGHT-SAC-CALHOUN-WEBSTER
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...DONAVON
AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
226 AM MST THU NOV 22 2012
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 226 AM MST THU NOV 22 2012
MAIN FORECAST ISSUE WILL BE THE WINDS TODAY WITH MINOR CONCERNS OF
HOW MUCH IT COOLS OFF THROUGH TOMORROW AND HOW MUCH THE WARM UP IS
ON SATURDAY. SATELLITE SHOWING AN AMPLIFIED PATTERN OVER THE PACIFIC
WITH A LESS AMPLIFIED MORE PROGRESSIVE FLOW FROM NORTH AMERICA INTO
THE ATLANTIC. COLD FRONT IS APPROACHING THE AREA FROM THE NORTHWEST.
AT JET LEVEL...THE ECMWF WAS DOING A LITTLE BETTER THAN THE UKMET...
CANADIAN...AND NAM ON THE JET SEGMENT ASSOCIATED WITH THE NORTHERN
STREAM SYSTEM. THE GFS FOLLOWED BY THE SREF WAS TOO STRONG WITH THE
JET BEHIND THE INCOMING TROUGH. AT MID LEVELS THE MODELS INITIALIZED
FINE WITH NO BIG PROBLEMS. THE RUC AND NAM WERE DOING BEST ON THE
WIND/PRESSURE FIELD. LOW LEVEL THERMAL GUIDANCE WAS CLOSE TO EACH
OTHER AND REALITY.
TODAY/TONIGHT...SATELLITE AND UPPER AIR IS SHOWING A VERY DRY AND
SUBSIDENT AIR MASS BEHIND THE SYSTEM MOVING ALONG THE CANADIAN AND
UNITED STATES BORDER.
SURFACE TO 850 MB WINDS ARE HIGHEST AT 12Z AND THEN DECREASE BY 18Z.
SOME PLACES COULD REACH 35 KNOT GUSTS. HIGHEST OBSERVED 3 HOUR
PRESSURE RISES HAVE OCCURRED MUCH FURTHER NORTH AND ARE NOT ANYTHING
OUT OF THE ORDINARY AT THIS TIME. FORECAST PRESSURE GRADIENT AND 3
HOUR PRESSURE RISES ARE HIGHEST EARLY ON AND DECREASE BY 18Z. IN FACT
BOTH WOULD INDICATE A QUICK BURST OF THE STRONGEST WINDS RIGHT AFTER
THE FROPA AND SUPPORT WINDY CONDITIONS BUT NOT QUITE AT ADVISORY
CRITERIA. STRONGEST SUBSIDENCE LOOKS TO BE NEAR THE NORTHERN PORTION
OF OUR AREA. THAT AND OTHER GUIDANCE WOULD SUPPORT THE HIGHEST WINDS
TO BE IN THE NORTHERN PORTION OF THE AREA AND MAYBE SOME OF THE
SOUTHWEST. SO HAVE CONTINUE TO HAVE WINDS JUST UNDER ADVISORY
CRITERIA WITH THE NORTH THE CLOSEST.
HIGH LEVEL CLOUDS WILL BE THICKEST EARLY DUE TO THE RIGHT REAR
QUADRANT OF THE MID AND UPPER JET BEING CLOSE. OVERNIGHT
TEMPERATURES HAVE BEEN ALL OVER THE PLACE AS THE PREFRONTAL TROUGH
WORKS ITS WAY ACROSS. FRONT LOOKS TO PUSH THROUGH THE AREA EARLY
TODAY. NWP IS WARMER THAN IT WAS YESTERDAY AND IN CLOSE AGREEMENT.
MADE ONLY SLIGHT ADJUSTMENTS.
GUIDANCE THIS MORNING KEEPS THE WINDS STRONGER FOR TONIGHT THAN THE
IT DID YESTERDAY DUE TO THE SURFACE RIDGE MOVING IN A LITTLE
SLOWER. SO WARMED UP THE MINS.
FRIDAY/FRIDAY NIGHT...SHOULD SEE PLENTY OF SUN WITH AREA COMING
UNDER THE CONTROL OF RIDGING/SUBSIDENCE/DRYING. SURFACE HIGH MOVES
ACROSS DURING THE DAY AND IS NOT TOO FAR EAST OF THE AREA BY LATE IN
THE AFTERNOON. NEW GUIDANCE IS CLOSE TO EACH OTHER AND NOT TOO
DIFFERENT FROM ONGOING FORECAST SO MADE LITTLE IF ANY CHANGES. WIND
FIELD STARTS OUT LIGHT BEFORE WAA AND DOWNSLOPE STARTS. TEMPERATURES
COULD FALL RAPIDLY BEFORE THIS GETS GOING.
SATURDAY/SATURDAY NIGHT...AGAIN LOOKS LIKE A LOT OF SUN THROUGH THE
DAY. WINDS STAY LIGHT THROUGH THE DAY BUT MOSTLY FROM A DOWNSLOPE
DIRECTION. NEWER GUIDANCE IS PRETTY CLOSE TO EACH OTHER AND WARMER
THAN CURRENT FORECAST. CONSIDERING THE DEEP/INCREASING WESTERLY FLOW
ALOFT THIS DOES MAKE SENSE. DRY AIR MASS AND DRY GROUND SHOULD ALLOW
A QUICK RESPONSE TO THE EVEN LIGHT DOWNSLOPE WIND. HOWEVER MAY HAVE
SOME WAVE CLOUDS DEVELOP EVEN THOUGH MODELS SAY NO. WILL WARM UP
MAXES SOME AT THIS TIME.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 1142 PM MST WED NOV 21 2012
SHORTWAVE TROUGH WILL MOVE FROM THE NORTHERN ROCKIES TO THE
CENTRAL PLAINS SUNDAY NIGHT AND MONDAY. MODEL SOLUTIONS CONTINUE TO
RETREAT FROM PRECIPITATION CHANCES...AND ITS LOOKING LIKE LITTLE
TO NONE IN THE LOCAL AREA. COLDER AIR WILL MOVE IN BEHIND THE COLD
FRONT SUNDAY NIGHT BUT COOL DOWN WILL BE SHORT LIVED. UPPER RIDGE
WILL QUICKLY REBUILD OVER THE GREAT BASIN EARLY IN THE WEEK THEN
ROCKIES BY MID WEEK. TEMPERATURES WILL RETURN TO ABOVE NORMAL BY
TUESDAY WITH NO PRECIPITATION CHANCES.
&&
.AVIATION...FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1026 PM MST WED NOV 21 2012
VFR CONDITIONS ARE EXPECTED FOR THE NEXT 24 HOURS. THE ONLY CLOUD
COVER WILL BE SOME CIRRUS MOVING THROUGH THIS MORNING FROM THE
WEST. OF BIGGER CONCERN FOR AVIATION WILL BE THE WINDS THIS
AFTERNOON. A COLD FRONT AND LEE TROUGH WILL PUSH THROUGH DURING
THE FORECAST PERIOD. A TIGHT PRESSURE GRADIENT AND STRONGER WINDS
ALOFT WILL ALLOW FOR GUSTY NORTH WINDS AT THE SURFACE. WINDS WILL
GRADUALLY PICK UP IN THE MORNING HOURS AND WINDS FOR THE AFTERNOON
HOURS LOOK TO BE SUSTAINED AT AROUND 25 KTS WITH GUSTS TO 35
SUGGESTED BY GUIDANCE. WINDS WILL WEAKEN BY THIS EVENING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...024
AVIATION...RRH
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1100 PM CST WED NOV 21 2012
...UPDATE TO AVIATION FOR 06Z TAFS...
.SYNOPSIS...
ISSUED AT 1023 PM CST WED NOV 21 2012
THE 22.00Z 250 HPA MAP SHOWED A 100 KT NORTHWESTERLY JET ACROSS THE
PACIFIC NORTHWEST ON THE UPSTREAM SIDE OF A LONGWAVE TROF LOCATED ACROSS
THE NORTHERN ROCKIES. ANOTHER JET STREAK OF AROUND 110 KT WAS FOUND
ON THE BASE OF A VERY AMPLIFIED TROF LOCATED ACROSS FLORIDA AND THE
SW ATLANTIC BASIN. A VERY SUBTLE WIND MAX AROUND 50 KT WAS ALSO OBSERVED
AT KDDC (DODGE CITY, KS). AT 500 HPA, VERY COLD MID LEVEL TEMPS OF -30
DEG C TO -35 DEG C WERE OBSERVED ACROSS THE PACIFIC NORTHWEST. CLOSER
TO HOME, SOME MID LEVEL MOISTURE WAS NOTED ACROSS WEST TEXAS AHEAD OF
A WEAK PRESSURE PERTURBATION. DRY AIR ADVECTION WAS NOTED ACROSS THE
DEEP SOUTH IN THE WAKE OF THE AFOREMENTIONED UL DISTURBANCE. AT 700
HPA, TEMPS WERE WARM ACROSS THE CENTRAL PLAINS FOR NOVEMBER STANDARDS
WITH MANY LOCATIONS REPORTING IN THE 5 DEG C TO 8 DEG C RANGE. THE ATMOSPHERE
WAS FAIRLY DRY IN THIS AREA AS WELL. 850 HPA TEMPS ACROSS THE PLAINS
WERE WARM WITH A DRY/ADIABATICALLY MIXED PROFILE ACROSS KANSAS. TEMPS
AROUND 15 DEG C TO 17 DEG C WERE COMMON FROM WEST TEXAS TO MINNESOTA.
AT THE SFC, TWO FRONTAL SYSTEMS WERE NOTED ACROSS THE NORTHERN PRAIRIES.
A LEE TROUGH WAS ALSO NOTED ACROSS EASTERN COLORADO. A RIDGE AXIS OF
HIGH PRESSURE EXTENDED FROM THE NORTHERN GULF NE TO NEW ENGLAND.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 343 PM CST WED NOV 21 2012
FOR THE TIME PERIOD TONIGHT AND TOMORROW, THE GREATEST CHALLENGE IN
THE FORECAST WILL BE LOWS TONIGHT AND HOW MUCH CLOUD COVER AND WIND
WILL INFLUENCE OVERNIGHT TEMPERATURES. THE PREVIOUS FORECAST
ALREADY HAD A FAIRLY TIGHT GRADIENT IN LOW TEMPERATURES TONIGHT
(FROM 33F ACROSS FAR WEST CENTRAL KANSAS TO AROUND 51F ACROSS FAR
SOUTH CENTRAL KANSAS). THESE LOOK GOOD FOR THE MOST PART, BUT THE
LATEST RAP AND NAM12 MODELS SUGGEST TEMPERATURES WILL NOT GET MUCH
BELOW 60F SOUTHEAST OF A GREAT BEND TO ASHLAND LINE, AND GIVEN THE
SEMI OPAQUE SKY COVER FROM 300-500MB CLOUD (FROM THE SUBTROPICAL
SHORTWAVE TROUGH) AND THE SOUTHWEST WINDS CONTINUING 12 TO 16 KNOTS
IN THESE AREAS, REALLY CANNOT ARGUE AGAINST THESE WARM TEMPERATURES
TONIGHT. AS A RESULT, I HAVE BUMPED UP MIN TEMPS ABOUT 2 TO 4
DEGREES AND MOVED THE GRADIENT WESTWARD ABOUT 30 MILES OR SO
(EFFECTIVELY WARMING UP DODGE CITY LOW QUITE A BIT).
THE FORECAST FOR THANKSGIVING DAY WILL BE A LITTLE LESS COMPLICATED
AS MID-HIGH LEVEL CLOUD COVER WILL BE MOVING EAST OF THE AREA WITH
SURFACE WINDS BECOMING NORTHWESTERLY. WHILE COLD ADVECTION WILL
EXIST BEHIND THE FRONT, THE AIRMASS WILL BE MODIFIED BY DOWNSLOPE
AND INSOLATION WILL ALSO COUNTER THE COLD ADVECTION. HIGHS WILL
STILL BE ABOVE AVERAGE FOR THE DATE WITH TEMPERATURES WARMING INTO
THE 60S (LOWER 70S SOUTH CENTRAL KS). WITH THE INITIAL ISALLOBARIC
WIND SURGE/PRESSURE RISE WITH THE PASSAGE OF THE FRONT, WIND SPEEDS
WILL BE 22 TO 26 KNOTS MUCH LIKE TODAY, BUT THESE SPEEDS SHOULD ONLY
OCCUR DURING ABOUT A 3 OR 4 HOUR PERIOD BEFORE WINDS GRADUALLY
DECREASE BACK DOWN TO THE 18 TO 22 KT RANGE LATE IN THE DAY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 248 PM CST WED NOV 21 2012
BY THE BEGINNING OF THE EXTENDED PERIOD ON THURSDAY NIGHT, A STRONG
UPPER LEVEL SHORTWAVE TROUGH WILL BE MOVING OUT OF THE NORTHERN
PLAINS INTO THE MIDWESTERN STATES AND GREAT LAKES REGION. A COLD
FRONT WILL BE LOCATED OVER SOUTHEAST KANSAS INTO WEST TEXAS. HIGH
PRESSURE WILL BE BUILDING INTO WESTERN KANSAS BEHIND THE FRONT
THURSDAY NIGHT THROUGH FRIDAY. THE 12Z MODEL TEMPERATURE FORECASTS
ARE COMING IN COOLER THAN PREVIOUS RUNS WHICH SEEMS REASONABLE GIVEN
THE ONGOING COLD AIR ADVECTION.
INTO THIS WEEKEND, FLAT UPPER LEVEL RIDGING WILL SPREAD EAST ACROSS
THE WESTERN AND CENTRAL PART OF THE COUNTRY. ANOTHER SHORTWAVE
TROUGH WILL MOVE INTO THE PACIFIC NORTHWEST ON SATURDAY BEHIND THE
RIDGE AND THIS FEATURE WILL BE DIGGING SOME AS IT MOVES INTO THE
CENTRAL HIGH PLAINS BY MONDAY NIGHT. THROUGH THIS WEEKEND THE DRY
FORECAST WILL CONTINUE WITH TEMPERATURES WILL MODERATE BACK INTO THE
60S. LEE SIDE TROUGHING WILL DEVELOP ON SATURDAY. THIS WILL DEVELOP
INTO A LOW PRESSURE AREA THAT MOVES INTO THE OKLAHOMA AND TEXAS
PANHANDLES BY SUNDAY EVENING AS THE NEXT UPPER TROUGH APPROACHES.
THIS WILL BRING A SWITCH IN THE SURFACE WINDS BACK AROUND TO THE
EAST TO NORTHEAST ON SUNDAY. THIS WAVE WILL MOVE OUT ACROSS THE
CENTRAL AND NORTHERN PLAINS MONDAY NIGHT. THERE DOES NOT APPEAR TO
BE SUFFICIENT MOISTURE AVAILABLE FOR THIS SYSTEM TO WORK WITH. THE
BEST CHANCES FOR MEASURABLE PRECIPITATION WILL BE ALONG THE EASTERN
SLOPES OF THE ROCKIES AND OVER EASTERN KANSAS INTO THE MID
MISSISSIPPI VALLEY. HIGH TEMPERATURES WILL DROP BACK INTO THE 40S ON
MONDAY AND TUESDAY.
THE REMAINDER OF THE EXTENDED PERIOD WILL SEE AN UPPER LEVEL RIDGE
BUILDING OVER THE CENTRAL PART OF THE COUNTRY. THIS WILL RESULT IN
TEMPERATURES MODERATING BACK INTO THE 60S LATER NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1100 PM CST WED NOV 21 2012
A COLD FRONT WILL TRAVERSE ACROSS THE REGION THIS MORNING. WINDS WILL
INCREASE NORTHERLY 20-25 KT THROUGH LATE MORNING INTO THE EARLY AFTERNOON
VIA MIXING/MOMENTUM TRANSFER DOWNWARD. WINDS WILL DECREASE 10-15 KT BY
DUSK. OTHER THAN SOME MID TO HIGH LEVEL CLOUDS, CIGS WILL REMAIN VFR.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 52 66 24 53 / 0 0 0 0
GCK 41 64 22 53 / 0 0 0 0
EHA 41 65 23 53 / 0 0 0 0
LBL 47 67 24 55 / 0 0 0 0
HYS 42 63 21 51 / 0 0 0 0
P28 55 72 28 53 / 10 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...UMSCHEID
LONG TERM...GERARD
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1023 PM CST WED NOV 21 2012
...UPDATE TO SYNOPSIS...
.SYNOPSIS...
ISSUED AT 1023 PM CST WED NOV 21 2012
THE 22.00Z 250 HPA MAP SHOWED A 100 KT NORTHWESTERLY JET ACROSS THE
PACIFIC NORTHWEST ON THE UPSTREAM SIDE OF A LONGWAVE TROF LOCATED ACROSS
THE NORTHERN ROCKIES. ANOTHER JET STREAK OF AROUND 110 KT WAS FOUND
ON THE BASE OF A VERY AMPLIFIED TROF LOCATED ACROSS FLORIDA AND THE
SW ATLANTIC BASIN. A VERY SUBTLE WIND MAX AROUND 50 KT WAS ALSO OBSERVED
AT KDDC (DODGE CITY, KS). AT 500 HPA, VERY COLD MID LEVEL TEMPS OF -30
DEG C TO -35 DEG C WERE OBSERVED ACROSS THE PACIFIC NORTHWEST. CLOSER
TO HOME, SOME MID LEVEL MOISTURE WAS NOTED ACROSS WEST TEXAS AHEAD OF
A WEAK PRESSURE PERTURBATION. DRY AIR ADVECTION WAS NOTED ACROSS THE
DEEP SOUTH IN THE WAKE OF THE AFOREMENTIONED UL DISTURBANCE. AT 700
HPA, TEMPS WERE WARM ACROSS THE CENTRAL PLAINS FOR NOVEMBER STANDARDS
WITH MANY LOCATIONS REPORTING IN THE 5 DEG C TO 8 DEG C RANGE. THE ATMOSPHERE
WAS FAIRLY DRY IN THIS AREA AS WELL. 850 HPA TEMPS ACROSS THE PLAINS
WERE WARM WITH A DRY/ADIABATICALLY MIXED PROFILE ACROSS KANSAS. TEMPS
AROUND 15 DEG C TO 17 DEG C WERE COMMON FROM WEST TEXAS TO MINNESOTA.
AT THE SFC, TWO FRONTAL SYSTEMS WERE NOTED ACROSS THE NORTHERN PRAIRIES.
A LEE TROUGH WAS ALSO NOTED ACROSS EASTERN COLORADO. A RIDGE AXIS OF
HIGH PRESSURE EXTENDED FROM THE NORTHERN GULF NE TO NEW ENGLAND.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 343 PM CST WED NOV 21 2012
FOR THE TIME PERIOD TONIGHT AND TOMORROW, THE GREATEST CHALLENGE IN
THE FORECAST WILL BE LOWS TONIGHT AND HOW MUCH CLOUD COVER AND WIND
WILL INFLUENCE OVERNIGHT TEMPERATURES. THE PREVIOUS FORECAST
ALREADY HAD A FAIRLY TIGHT GRADIENT IN LOW TEMPERATURES TONIGHT
(FROM 33F ACROSS FAR WEST CENTRAL KANSAS TO AROUND 51F ACROSS FAR
SOUTH CENTRAL KANSAS). THESE LOOK GOOD FOR THE MOST PART, BUT THE
LATEST RAP AND NAM12 MODELS SUGGEST TEMPERATURES WILL NOT GET MUCH
BELOW 60F SOUTHEAST OF A GREAT BEND TO ASHLAND LINE, AND GIVEN THE
SEMI OPAQUE SKY COVER FROM 300-500MB CLOUD (FROM THE SUBTROPICAL
SHORTWAVE TROUGH) AND THE SOUTHWEST WINDS CONTINUING 12 TO 16 KNOTS
IN THESE AREAS, REALLY CANNOT ARGUE AGAINST THESE WARM TEMPERATURES
TONIGHT. AS A RESULT, I HAVE BUMPED UP MIN TEMPS ABOUT 2 TO 4
DEGREES AND MOVED THE GRADIENT WESTWARD ABOUT 30 MILES OR SO
(EFFECTIVELY WARMING UP DODGE CITY LOW QUITE A BIT).
THE FORECAST FOR THANKSGIVING DAY WILL BE A LITTLE LESS COMPLICATED
AS MID-HIGH LEVEL CLOUD COVER WILL BE MOVING EAST OF THE AREA WITH
SURFACE WINDS BECOMING NORTHWESTERLY. WHILE COLD ADVECTION WILL
EXIST BEHIND THE FRONT, THE AIRMASS WILL BE MODIFIED BY DOWNSLOPE
AND INSOLATION WILL ALSO COUNTER THE COLD ADVECTION. HIGHS WILL
STILL BE ABOVE AVERAGE FOR THE DATE WITH TEMPERATURES WARMING INTO
THE 60S (LOWER 70S SOUTH CENTRAL KS). WITH THE INITIAL ISALLOBARIC
WIND SURGE/PRESSURE RISE WITH THE PASSAGE OF THE FRONT, WIND SPEEDS
WILL BE 22 TO 26 KNOTS MUCH LIKE TODAY, BUT THESE SPEEDS SHOULD ONLY
OCCUR DURING ABOUT A 3 OR 4 HOUR PERIOD BEFORE WINDS GRADUALLY
DECREASE BACK DOWN TO THE 18 TO 22 KT RANGE LATE IN THE DAY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 248 PM CST WED NOV 21 2012
BY THE BEGINNING OF THE EXTENDED PERIOD ON THURSDAY NIGHT, A STRONG
UPPER LEVEL SHORTWAVE TROUGH WILL BE MOVING OUT OF THE NORTHERN
PLAINS INTO THE MIDWESTERN STATES AND GREAT LAKES REGION. A COLD
FRONT WILL BE LOCATED OVER SOUTHEAST KANSAS INTO WEST TEXAS. HIGH
PRESSURE WILL BE BUILDING INTO WESTERN KANSAS BEHIND THE FRONT
THURSDAY NIGHT THROUGH FRIDAY. THE 12Z MODEL TEMPERATURE FORECASTS
ARE COMING IN COOLER THAN PREVIOUS RUNS WHICH SEEMS REASONABLE GIVEN
THE ONGOING COLD AIR ADVECTION.
INTO THIS WEEKEND, FLAT UPPER LEVEL RIDGING WILL SPREAD EAST ACROSS
THE WESTERN AND CENTRAL PART OF THE COUNTRY. ANOTHER SHORTWAVE
TROUGH WILL MOVE INTO THE PACIFIC NORTHWEST ON SATURDAY BEHIND THE
RIDGE AND THIS FEATURE WILL BE DIGGING SOME AS IT MOVES INTO THE
CENTRAL HIGH PLAINS BY MONDAY NIGHT. THROUGH THIS WEEKEND THE DRY
FORECAST WILL CONTINUE WITH TEMPERATURES WILL MODERATE BACK INTO THE
60S. LEE SIDE TROUGHING WILL DEVELOP ON SATURDAY. THIS WILL DEVELOP
INTO A LOW PRESSURE AREA THAT MOVES INTO THE OKLAHOMA AND TEXAS
PANHANDLES BY SUNDAY EVENING AS THE NEXT UPPER TROUGH APPROACHES.
THIS WILL BRING A SWITCH IN THE SURFACE WINDS BACK AROUND TO THE
EAST TO NORTHEAST ON SUNDAY. THIS WAVE WILL MOVE OUT ACROSS THE
CENTRAL AND NORTHERN PLAINS MONDAY NIGHT. THERE DOES NOT APPEAR TO
BE SUFFICIENT MOISTURE AVAILABLE FOR THIS SYSTEM TO WORK WITH. THE
BEST CHANCES FOR MEASURABLE PRECIPITATION WILL BE ALONG THE EASTERN
SLOPES OF THE ROCKIES AND OVER EASTERN KANSAS INTO THE MID
MISSISSIPPI VALLEY. HIGH TEMPERATURES WILL DROP BACK INTO THE 40S ON
MONDAY AND TUESDAY.
THE REMAINDER OF THE EXTENDED PERIOD WILL SEE AN UPPER LEVEL RIDGE
BUILDING OVER THE CENTRAL PART OF THE COUNTRY. THIS WILL RESULT IN
TEMPERATURES MODERATING BACK INTO THE 60S LATER NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 505 PM CST WED NOV 21 2012
VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES THROUGH EARLY
THURSDAY AFTERNOON. AS FOR WINDS, A LEE SIDE TROUGH OF LOW
PRESSURE IN EXTREME EASTERN COLORADO WILL BEGIN EDGING EAST
INTO WESTERN KANSAS THIS EVENING. AS A RESULT, SOUTHERLY WINDS
OF 15 TO 25KT EARLY THIS EVENING WILL BECOME MORE SOUTHWESTERLY
WHILE DECREASING 5 TO 15KT OVERNIGHT. A COLD FRONT IS THEN
EXPECTED TO PUSH SOUTHEAST ACROSS WESTERN KANSAS EARLY THURSDAY
MORNING TURNING WINDS NORTHERLY 25 TO 35KT BY MID DAY THURSDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 52 66 24 53 / 0 0 0 0
GCK 41 64 22 53 / 0 0 0 0
EHA 41 65 23 53 / 0 0 0 0
LBL 47 67 24 55 / 0 0 0 0
HYS 42 63 21 51 / 0 0 0 0
P28 55 72 28 53 / 10 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...UMSCHEID
LONG TERM...GERARD
AVIATION...JJOHNSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
257 AM EST THU NOV 22 2012
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 437 PM EST WED NOV 21 2012
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG EXTENDING
NEWD FM THE SRN PLAINS INTO THE GRT LKS BTWN A TROF ALONG THE E
COAST AND ANOTHER ALONG THE W COAST. THE AIRMASS ALOFT IS QUITE WARM
AND DRY OVER THE UPR GRT LKS...BUT LO CLDS ENHANCED BY RADIATIONAL
COOLING LAST NGT THAT FORMED UNDER SHARP LLVL INVRN SHOWN ON LOCAL
12Z RAOBS ARE PROVING TO BE QUITE RESILIENT OVER THE SCENTRAL AND
ERN CWA WITH ADDED MOISTENING OFF LK MI IN SSW FLOW BTWN HI PRES IN
THE MID ATLANTIC AND LOWER PRES IN THE PLAINS. THERE IS NO FOG/ST
NOTED TO THE W...BUT PLENTY OF HI CLDS ARE STREAMING ENEWD FM THE
PLAINS INTO THE UPR LKS IN THE WSW FLOW ALF. A POTENT SHRTWV IS
COMING ASHORE IN THE PAC NW.
LATE THIS AFTN...LO CLDS PRESENT EARLY THIS AFTN OVER THE SCENTRAL
AND E WILL BREAK UP THRU THE AFTN IN THE PRESENCE OF SOME DIURNAL
HEATING. THESE CLDS WL BE MOST RESILIENT OVER THE FAR E DOWNWIND OF
LK MI AS STLT IMAGERY SHOWS ST DECK EXTENDING ALMOST THE ENTIRE
LENGTH OF THE LK.
TNGT...ALTHOUGH THE ST SHOULD BE GONE THIS EVNG EXCEPT OVER THE FAR
E...SUSPECT THIS LO CLD WL FORM AGAIN TNGT WITH NOCTURNAL COOLING
AND PERSISTENT SSW FLOW/LO INVRN SHOWN ON FCST SDNGS. CONFIDENCE IN
THIS SCENARIO IS HIER SINCE THE 12Z NAM/LOCAL WRF-ARW SHOW HIER
H95-9 SPECIFIC HUMIDITY ADVECTING INTO THE AREA OVERNGT IN THE
STRENGTHENING LLVL SSW FLOW. H925 WINDS AS HI AS 30-40KTS BY LATE
TNGT SHOULD LIMIT THE POTENTIAL FOR DENSER FOG...BUT STILL ADDED
SOME PATCHY FOG OVER THE SCENTRAL AND E AWAY FM MORE PRONOUNCED
DOWNSLOPE WARMING OVER THE NW AND NCENTRAL AS MODELS HINT AT A
PERIOD OF LIGHTER WINDS THIS EVNG THAT MIGHT AUGMENT A PERIOD OF
QUICK COOLING. MIN TEMPS WL REMAIN WELL ABV NORMAL WITH INCRSG
WINDS/ QUITE A BIT OF HI CLD...ESPECIALLY IN THE DOWNSLOPE AREAS
OVER THE W AND NCENTRAL NEAR LK SUP.
THANKSGIVING DAY...WITH DIURNAL HEATING...EXPECT LO CLDS/FOG IN THE
MRNG TO BREAK UP BY NOON. BUT WITH PERSISTENT SSW FLOW...THE ST WL
MOST LIKELY LINGER LONGER INTO THE AFTN OVER THE E DOWNSTREAM OF LK
MI. ATTENTION THEN TURNS TO TIMING/IMPACT OF SHRTWV NOW MOVING INTO
THE PAC NW. MODELS SHOW THIS DISTURBANCE MOVING EWD TO OVER MN BY
00Z FRI. ALTHOUGH ASSOCIATED SFC LO PRES IS FCST TO MOVE INTO
ONTARIO JUST N OF LK SUP WITH ATTENDANT COLD FNT PROGGED TO REACH
CENTRAL UPR MI BY 00Z...DEEP LARGER SCALE FORCING IS FCST TO HANG TO
THE W THRU THAT TIME. WITH LINGERING MID LVL DRY AIR...ANY
ACCOMPANYING PCPN SHOULD PUSH NO FARTHER THAN WRN LK SUP UNTIL AFT
00Z. OTRW... LOOK FOR ANOTHER DAY OF WELL ABV NORMAL TEMPS UNDER H85
THERMAL RDG UP TO 11C RIGHT AHEAD OF THE FNT. BUT TEMPS OVER THE W
SHOULD FALL IN THE AFTN FOLLOWING THE COLD FROPA WITH H85 TEMPS
PROGGED TO TUMBLE TOWARD 0C AT IWD BY 00Z FRI.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 437 PM EST WED NOV 21 2012
MODEL HAVE COME INTO MUCH BETTER OVERALL AGREEMENT RELATING TO THE
SYSTEM THAT WILL BRING SNOW TO MUCH OF THE AREA THU NIGHT INTO
SAT...WITH MAINLY SMALLER SCALE/TIMING DIFFERENCES THAT ARE NOT OUT
OF THE NORM FOR THE TIME FRAME OF THE EVENT. A GENERAL MODEL
CONSENSUS WAS USED...WITH MOST FORECAST ALIGNMENT WITH THE 12Z/21
NAM/GFS AND TO A SOMEWHAT LESSER DEGREE THE 00Z/21 ECMWF
FOCUSED MAJORITY OF ATTENTION ON THE SYSTEM THU NIGHT INTO SAT GIVEN
HIGHER IMPACTS FROM POST THANKSGIVING TRAVEL/ACTIVITIES.
AT 00Z FRI...MODELS SHOW THE 500MB SHORTWAVE IN THE BEGINNING STAGES
OF BEING CLOSED OFF OVER NW MN WITH A 1000MB SFC LOW OVER CENTRAL
LAKE SUPERIOR...AND A SFC COLD FRONT FROM THE HURON MOUNTAINS TO
IRON OR DICKINSON COUNTY. 850MB TEMPS WILL BE JUST FALLING BELOW 0C
OVER FAR WRN UPPER MI...BUT WILL STILL BY AROUND 6C OVER THE ERN
CWA. THE MID LEVEL LOW WILL CONTINUE TO STRENGTHEN AS IT MOVES TO
THE CENTRAL CWA BY 12Z FRI /AVG LOCATION AMONG PREFERRED
MODELS...THERE WERE MINOR TIMING DIFFERENCES/...WITH HEIGHT FALLS OF
7-10DAM FROM 12 HOURS PREVIOUS. BY 12Z FRI THE BULK OF THE SFC LOW
WILL HAVE SHIFTED NE INTO ONTARIO...BUT PREFER THE NAM/GEM/ECMWF
SOLUTIONS THAT PIN A 998MB SFC LOW OVER NE LAKE SUPERIOR AS OFTEN
HAPPENS DUE TO THE WARM LAKE TEMPS. 850MB TEMPS FALL TO -10C TO -12C
OVER WRN LAKE SUPERIOR BY 12Z FRI...AND WILL WELL BELOW 0C OVER THE
REST OF THE CWA. THE COMBINATION OF THE DEEPENING SFC LOW...COLD AIR
OVER THE WARM LAKE AND SHARP PRESSURE GRADIENT LEAD TO STRONG WINDS.
THE STRONGEST WINDS LOOK TO BE OVER THE KEWEENAW AND NEAR LAKE
SUPERIOR E OF THE HURON MOUNTAINS...ESPECIALLY ALONG THE SHORELINES
OF ALGER AND LUCE COUNTIES. IN THESE AREAS...MODELS SHOW 925MB WINDS
IN EXCESS OF 40KTS...SO GUSTS AS HIGH AS 40KTS SEEM APPROPRIATE FOR
THE FORECAST IN THESE MORE EXPOSED LOCATIONS FROM THE NW WINDS LATE
THU NIGHT AND THROUGH MUCH OF FRI. A SHORT SWATH OF DRY LOW AND MID
LEVEL AIR ROTATES THROUGH THE WRN CWA LATE FRI MORNING...WHICH WILL
DIMINISH SNOWFALL TO SOME EXTENT. MODELS THEN INDICATE ANOTHER
SHORTWAVE PUSHING THROUGH SOMETIME SAT EVENING AS 850MB TEMPS FALL
TO -14C OVER MUCH OF LAKE SUPERIOR...WHICH WILL ACT TO ENHANCE
SNOWFALL RATES. AFTER THIS SHORTWAVE...SNOWFALL SHOULD GENERALLY
SLOWLY DIMINISH IN INTENSITY/COVERAGE UNTIL SFC AND UPPER RIDGING
MOVES IN FROM THE W SAT...REACHING IWD BY 18Z SAT AND THE FAR ERN
CWA AROUND 00Z SUN.
GIVEN HOW QUICKLY TEMPS GET COLD AS THE UPPER LOW IS MOVING
OVER...SNOW TO LIQUID RATIOS WILL JUMP UP PRETTY QUICKLY TO AROUND
18 TO 1 RATIOS. THIS WILL INCREASE SNOWFALL ACCUMULATIONS AND WILL
ALLOW THE SNOW TO BE BLOW AROUND MORE FROM GUSTY WINDS. EXPECT TWO
MAIN BURSTS OF SNOW THAT SHOULD BE ESPECIALLY UNTACTFUL...ONE AS THE
UPPER LOW PUSHES IN WITH LAKE ENHANCEMENT ADDING TO SNOW INTENSITY.
THIS WILL HAPPEN THU NIGHT INTO EARLY FRI MORNING OVER THE WRN
CWA...AND FRI MORNING TO AROUND NOON FRI OVER THE ERN CWA. THE
SECOND BURST LOOKS TO BE WITH THE SECOND SHORTWAVE FRI EVENING TO
EARLY SAT NIGHT WITH ENHANCEMENT OF THE LES. THE FIRST BURST OF SNOW
LOOKS TO BE THE WORST GIVEN THE INCREASED FORCING FROM THE 500MB
LOW...WHICH WILL ALSO BE AT THE WORST TIMES GIVEN MUCH INCREASED
POST THANKSGIVING TRAVEL/ACTIVITY AS FAR A SOCIETAL IMPACTS GO. THIS
IS COMPOUNDED BY THE FACT THAT NO SIGNIFICANT SNOWFALL HAS OCCURRED
IN A WHILE...WHICH LOCAL STUDIES SUGGEST LEADS TO A LARGE INCREASE
IN TRAFFIC ACCIDENTS ONCE SNOW DOES FALL.
AS FAR AS SNOWFALL AMOUNTS GO...HAVE HIGHEST CONFIDENCE IN SNOWFALL
AMOUNTS OF PORTIONS OF ALGER...LUCE AND NRN SCHOOLCRAFT COUNTIES
WHERE MOISTURE WILL LINGER LONGER AND THE FETCH ACROSS LAKE SUPERIOR
WILL BE BETTER AND NW WINDS WILL NOT CHANGE DIRECTIONS MUCH THROUGH
THE EVENT. OVER THESE ERN AREAS...THE NAM SHOWS STORM TOTAL QPF
/WHICH SHOULD BE ALMOST ALL SNOW/ OF JUST UNDER 0.80 INCHES...WHICH
MAY BE A BIT ON THE HIGH SIDE BUT CAN NOT BE RULED OUT.
OVERALL...THINK 6-10 INCHES /WITH SOME POTENTIAL FOR UP TO A FOOT/
TOTAL SNOWFALL SEEMS REASONABLE FOR THE ERN AREAS. LOWEST CONFIDENCE
IS OVER THE NRN HURON MOUNTAINS IN NW MARQUETTE AND NE BARAGA
COUNTIES...AS THIS AREA IS ALWAYS HARD TO FORECAST IN NW WINDS...BUT
WOULD THINK 3-5 INCHES STORM TOTAL SNOW IS REASONABLE. THE HIGHER
TERRAIN OF WRN UPPER MI FROM IWD TO CMX AND COPPER HARBOR SHOULD SEE
4-8 INCHES STORM TOTAL SNOW /HIGHEST OVER PORTION OF NRN HOUGHTON
COUNTY AND WRN ONTONAGON/NRN GOGEBIC COUNTIES/...BUT WITH MORE
UNCERTAINTY THAT THE ERN CWA AND MORE HIGHER POSSIBILITIES OF HIGHER
OR LOWER AMOUNTS. NCENTRAL PARTS OF THE CWA /GENERALLY IN THE
MARQUETTE-NEGAUNEE AREA/ LOOK TO SEE 1-3 INCHES OF SNOW THROUGH THE
ENTIRE PERIOD. SCENTRAL PORTIONS OF THE CWA SHOULD SEE LITTLE TO NO
SNOW.
HEADLINES FOR THIS EVENT ARE SOMEWHAT TRICKY IN THAT TRADITIONAL
SNOWFALL AMOUNT BASED CRITERIA WILL NEED TO BE RELAXED GIVEN A
VARIETY OF PREVIOUSLY DISCUSSED SOCIETAL IMPACTS AND OTHER
CONTRIBUTING FACTORS /SUCH AS GUSTY WINDS/. GIVEN HIGHER CONFIDENCE
OVER THE ERN CWA /ALGER...LUCE AND NRN SCHOOLCRAFT COUNTIES/ DECIDED
TO ISSUE A WINTER STORM WATCH FOR THESE AREAS. ELSEWHERE ALONG THE
LAKE SUPERIOR SHORE...ISSUED AN SPS HIGHLIGHTING POOR TRAVEL
CONDITIONS SINCE IT IS TOO FAR OUT FOR AN ADVISORY.
NEXT SYSTEM OF INTEREST MOVES OVERHEAD ON SAT NIGHT INTO EARLY SUN
AS A CLIPPER SYSTEM PUSHES THROUGH. BEST MOISTURE IS CO-LOCATED WITH
UPPER SUPPORT IN LEFT EXIT REGION OF UPPER JET OVER NRN PORTIONS OF
THE AREA. INCREASED CONSENSUS GUIDANCE TO MID RANGE CHANCE POPS. AT
THIS TIME A COUPLE OF INCHES OF SNOW APPEARS POSSIBLE...MAINLY IN
THE HIGHER TERRAIN OVER THE NRN CWA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 257 AM EST THU NOV 22 2012
AT KSAW...IFR VIS THAT HAS DEVELOPED UNDER RADIATIONAL COOLING WILL
LIKELY PERSIST THRU THE NIGHT. IFR CIGS MAY ALSO SET IN AT SOME
POINT DURING THE NIGHT. VFR CONDITIONS SHOULD PREVAIL AT KIWD/KCMX
OVERNIGHT AS DOWNSLOPE NATURE OF SSW FLOW SHOULD LIMIT THE POTENTIAL
FOR LOW CLOUDS/FOG. LLWS IS EXPECTED AS SSW WINDS ABOVE RADIATION
INVERSION HAVE INCREASED TO 30KT PER KMQT VAD WIND PROFILE. WINDS
SHOULD CONTINUE TO INCREASE A LITTLE MORE DURING THE NIGHT. DAYTIME
HEATING/MIXING SHOULD END LLWS/DISSIPATE ANY LOW CLOUDS/FOG BY LATE
MORNING. ARRIVAL OF COLD FRONT LATE IN THE DAY WILL LIKELY BRING LOW
MVFR CIGS TO KIWD/KCMX AFTER 20Z. RA/SN CHANGING TO SN WILL DEVELOP
AT KIWD/KCMX IN THE EVENING AND SPREAD TO KSAW LATE EVENING. A
PERIOD OF AT LEAST MDT SNOW/LIFR CONDITIONS IS ANTICIPATED AT KCMX
MID TO LATE EVENING AS SECONDARY COLD FRONT BOOSTS LAKE ENHANCEMENT
UNDER STRONG CAA.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 437 PM EST WED NOV 21 2012
EXPECT S WINDS UP TO 20 KTS THRU THIS EVENING TO INCREASE UP TO 25
KTS LATE TONIGHT AND THU UNDER TIGHTENING PRES GRADIENT AHEAD OF
COLD FRONT ASSOCIATED WITH POWERFUL DISTURBANCE MOVING ACROSS THE
NORTHERN CONUS. ONCE THE COLD FRONT MOVES WEST TO EAST THU AFTERNOON
AND NIGHT...EXPECT A SHARP WIND SHIFT TO THE NW. AS THE PRES
GRADIENT TIGHTENS CONSIDERABLY AND MUCH COLDER AIR MOVES OVER THE
UPPER LAKES...EXPECT A HI END GALE EVENT EXCEPT OVER THE FAR W WITH
THE COLDER AIR ENHANCING THE MIXING OF STRONGER WINDS ALOFT TO THE
LAKE SURFACE. GIVEN THE CONSISTENT FORECAST TIMING AND STRENGTH OF
THIS EVENT...OPTED TO UPGRADE GOING GALE WATCHES TO WARNINGS FOR THE
LATE THU NIGHT INTO FRI NIGHT PERIOD. SOME STORM FORCE WIND GUSTS
WILL ALSO BE POSSIBLE ON FRI...ESPECIALLY OVER THE E HALF OF THE
LAKE. THE APPROACH OF A HI PRES RIDGE LATE FRI NIGHT WILL CAUSE THE
GALES TO DIMINISH W-E THEN. ANOTHER LO PRES TROF WILL IMPACT THE
UPPER GREAT LAKES OVER THE WEEKEND...BUT A WEAKER PRES GRADIENT WILL
LIKELY HOLDS WINDS TO NO HIER THAN 25 KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER STORM WATCH FROM LATE TONIGHT THROUGH LATE FRIDAY NIGHT
FOR MIZ006-007-085.
LAKE SUPERIOR...
GALE WARNING FROM 1 AM FRIDAY TO 1 AM EST SATURDAY FOR
LSZ264>267.
GALE WARNING FROM 1 AM TO 7 PM EST FRIDAY FOR LSZ243>245-248>251-
263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
433 AM EST THU NOV 22 2012
.SYNOPSIS...
HIGH PRESSURE WILL BRING ANOTHER MILD AND SUNNY DAY TO CENTRAL NEW
YORK AND NORTHEAST PENNSYLVANIA. A COLD FRONT WILL PASS THE REGION
LATE FRIDAY AFTERNOON AND EVENING WITH SHOWERS. COLD AIR BEHIND
THIS FRONT WILL ALLOW LAKE EFFECT SNOWS TO DEVELOP OVER PORTIONS OF
CENTRAL NEW YORK LATE FRIDAY NIGHT...WHICH WILL PERSIST INTO
SATURDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
SFC HI PRES RDG XTNDG FROM NEW ENGLAND INTO THE MID ATLC STATES
WILL BRING ANOTHER VERY NICE DAY TO THE FCST AREA...WITH MOSTLY
SUNNY SKIES AND TEMPS WELL ABV NORMAL. GIVEN FCST 925 TEMPS OF +8
IT LOOKS LIKE WE`LL SEE MAXES FLIRTING WITH 60 IF NOT THE LOWER 60S
ACRS THE CNTRL SRN TIER AND FINGER LAKES...M/U 50S ELSEWHERE.
FAIR WX CONTNIUE TNGT WITH SRLY FLOW INCRSNG.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
WE`LL SEE SOME SUNSHINE AHEAD OF THE FNT ON FRI AND IT APPEARS
WE`LL HAVE MAXES WELL INTO THE 50S ONCE AGAIN. CDFNT WILL PASS
LATE FRI AFTN/FRI EVNG WITH A BAND OF -SHRA. COLDER AIR WORKS IN
BEHIND THE FNT FRI NGT INTO SAT. ATTM IT APPEARS THAT FLOW WILL
REMAIN WSW TIL ARND 06Z WITH FLOW BCMG MORE NWLY BY 12Z SAT. THE
NW FLOW PERSISTS INTO SAT NGT. CYCLONIC FLOW ALOFT...GOOD LOW LVL
INSTAB...DENDRITIC SNOW GROWTH AND FAIRLY HI INVERSION LVL SHOWN
IN IN THE PROFILES...WITH SOME HINT OF PSBL HURON BAY CONNECTION
TO ONTARIO ACTIVITY ON SAT. HOWEVER...SOME SUGGESTION THAT THE
SYNOPTIC AIR MASS MAY BE ON THE DRY SIDE (EURO SHOWS TD`S DROPPING
INTO THE L/M TEENS DURING THIS TIME FRAME). IN ANY EVENT...POTNL
APPEARS TO BE THERE FOR ACCUMULATIONS....PRBLY IN THE ADVISORY
RNG...SPCLY ACRS THE FAVORED TRRN IN 300-320 FLOW SAT INTO SAT NGT.
WILL CONTINUE TO MENTION IN THE HWO.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
345 AM UPDATE...
FORECAST ONLY ADJUSTED SLIGHTLY AS NEEDED FOR COLLABORATION
PURPOSES AND TO ACCOUNT FOR LATEST MODEL TRENDS. THE GENERAL IDEA
REMAINS THE SAME.
850MB RIDGE NEVER REALLY REACHES THE AREA...IT ACTUALLY FLATTENS
TO OBLIVION IN RESPONSE TO PASSING WAVE ON SUNDAY. WAVE EVENTUALLY
YIELDS WARM AIR ADVECTION ALOFT...BUT 850MB TEMPERATURES REMAIN
COLD ENOUGH FOR AT LEAST A MARGINAL CONTINUED LAKE RESPONSE. WARM
FRONT MAY STRUGGLE TO FILL THE DRY LAYER BETWEEN HIGH LEVEL
MOISTURE ASSOCIATED WITH WARM FRONT ALOFT...AND LAKE MOISTURE IN
THE LOWER LEVELS. REGARDLESS THOUGH...LAKE MOISTURE BY ITSELF MAY
BE ENOUGH FOR AT LEAST SCATTERED SNOW SHOWERS TO CONTINUE INTO A
WAYS INTO SUNDAY FOR CENTRAL NY WHILE SHIFTING NORTHWARD /BACKING
WIND/.
MODELS CONTINUE THEIR CONFUSION FOR HOW TO HANDLE LOW PRESSURE
SYSTEM MON NIGHT THROUGH TUE NIGHT PERIOD. ECMWF KEEPS US COLDER
YET IS SO FAR SOUTH WITH TRACK OF LOW /WHICH IS ALSO
WEAKER/...THAT DEPICTED PRECIPITATION SHIELD DOES NOT EVEN MAKE IT
INTO OUR AREA DUE TO STRENGTH OF SURFACE HIGH OVER EASTERN CANADA.
MEANWHILE GFS IS BETTER PHASED AND AMPLIFIED...AND THUS DEVELOPS
STRONGER SURFACE LOW THAT TRACKS UP OHIO VALLEY AND THROUGH THE
REGION. SOME WARMER AIR GETS INVOLVED IN THE GFS SOLUTION...WHICH
MAKES PRECIPITATION TYPE COMPLICATED YET EVENTUALLY TRANSITIONING
TO ALL SNOW SHOWERS IN THE WAKE OF THE POTENTIAL SYSTEM. WITH MUCH
UNCERTAINTY...KEEPING POPS ONLY IN CHANCE RANGE SEEMS BEST AT THIS
TIME.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
06Z UPDATE...
VFR FOR ENTIRE TAF PERIOD...EXCEPT FOR QUESTION OF EARLY MORNING
VALLEY FOG DEVELOPMENT IN KELM...AND SOME MVFR VIS FOR KITH. GREAT
RADIATIONAL COOLING SET UP AND SHARP INVERSION...SUPPORTIVE OF
KELM VALLEY FOG...IS COMPETING WITH VERY ATMOSPHERE /AFTER YET
ANOTHER DAYTIME OF NO PRECIP AND LOW HUMIDITY LEVELS/. RAP MODEL
SOUNDING OVERALL SEEMS TILTED IN FAVOR OF THE DRY AIR MASS...WITH THE
MORE DEGRADED CONDITIONS STAYING TO OUR NORTH AND WEST /AS IS
ALREADY OCCURRING FOR MANY TERMINALS ON THE ONTARIO PENINSULA/...WHERE
HIGHER DEWPOINTS WERE ABLE TO ADVECT IN EARLIER. I HAVE TO RESPECT
THE STILL FAIR SET UP FOR KELM...AND INCLUDED TEMPO IFR 11Z-13Z...BUT
OTHERWISE HELD THE LINE AT MVFR VIS EARLY THIS MORNING. LIGHT
EASTERLY FLOW WILL ALSO YIELD SOME MVFR VIS FOR A TIME EARLY THIS
MORNING. FOR KRME...WILL HAVE TO WATCH FOR POSSIBLE MVFR LIGHT FOG
BUT NOT IN TAF BECAUSE MOST LIKELY SCENARIO IS VFR.
OUTLOOK...
FRI...MVFR POSSIBLE ALONG AND BEHIND SHOWERY COLD FRONT AFTN/EVE.
FRI NGT...MVFR CIGS. LATE IFR VIS POSS KSYR-KRME FROM LAKE -SHSN.
SAT...MVRF/BRIEF IFR FROM LAKE -SHSN...MAINLY CNY TERMINALS.
SUN...RESTRICTIONS PSBL IN SCT SHRA/SHSN.
MON...MAINLY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
LONG TERM...MDP/PVN
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
410 AM EST THU NOV 22 2012
.SYNOPSIS...
WARM ABOVE AVERAGE TEMPERATURES WILL PREVAIL ACROSS THE REGION ON
THANKSGIVING DAY WITH MANY LOCATIONS EASILY WARMING INTO THE
MIDDLE TO UPPER 50S FOR DAYTIME HIGHS. ABOVE NORMAL TEMPERATURES
WILL QUICKLY COME TO AN END BY FRIDAY AS A STRONG COLD FRONT
SWINGS THROUGH THE REGION. COLD AIR WILL RAPIDLY OVERSPREAD THE
REGION FRIDAY NIGHT AND SATURDAY WITH REDEVELOPING LAKE EFFECT
SNOWS EXPECTED OVER THE UPCOMING WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1030 PM UPDATE...CURRENT FORECAST REMAINS IN GOOD SHAPE, JUST
LOWERED OVERNIGHT LOWS BY 2-4 DEGREES AS WEAK BOUNDARY LAYER FLOW
WILL PERSIST UNTIL DAYBREAK EVEN ALONG THE LAKE PLAIN. WITH DEW
POINTS CONTINUING TO FALL IN TANDEM WITH SFC TEMPS, DENSE FOG
FORMATION IS NOT EXPECTED.
530 PM UPDATE...CLEAR SKIES AND LIGHT WINDS HAVE ALLOWED TEMPS TO
FALL QUICKLY LATE THIS AFTERNOON. AT PENN YAN AND ELMIRA TEMPS
FELL 10 AND 13 DEGREES RESPECTIVELY DURING THE PAST HOUR. ADJUSTED
TEMP GRIDS TO REFLECT THIS OTHERWISE FORECAST IN GOOD SHAPE WITH
NO OTHER CHANGES.
PREVIOUS DISC...
VISIBLE SATELLITE IMAGERY SHOWING MOSTLY CLEAR SKIES ACROSS THE
REGION THIS AFTERNOON AS SFC RIDGING ASSOCIATED WITH CANADIAN
MARITIMES HIGH PRESSURE CONTINUES TO EXTEND SOUTHWEST OVER OUR
AREA. WITH ABUNDANT SUNSHINE PREVAILING OVERHEAD...TEMPS HAVE WARMED
INTO THE LOWER 50S ACROSS MUCH OF THE AREA WHICH IS ANYWHERE
BETWEEN 5-10 DEGREES ABOVE NORMAL. WITH A DRY AIRMASS IN
PLACE...TEMPS WILL FALL OFF QUICKLY THIS EVENING WITH OVERNIGHT
LOWS EXPECTED TO REACH THE LOWER TO MIDDLE 30S. THE ONLY CONCERN
WITH THE GOING FCST OVERNIGHT WILL BE POSSIBLE FOG FORMATION
TOWARDS MORNING. UPSTREAM OBSERVATIONS THIS MORNING SHOWED AN
EXPANSIVE AREA OF FOG ACROSS THE UPPER MIDWEST WHERE VISIBILITIES
WERE NEAR ZERO ACROSS THE GREATER CHICAGO AREA FOR HRS. THIS MOIST
LOW-LEVEL AIRMASS WILL ADVANCE EAST OVERNIGHT WHERE IT WILL
ENCOUNTER MORE AND MORE DRY AIR WITH FURTHER EASTWARD PROGRESS.
FOR NOW...STATISTICAL GUIDANCE MAKING NO SUGGESTION OF ANY FOG
FORMATION ACROSS OUR AREA HOWEVER EVENING SHIFT WILL HAVE TO
MONITOR TRENDS ACCORDINGLY.
UNSEASONABLY WARM TEMPS TO CONTINUE RIGHT THROUGH THANKSGIVING DAY
WHERE 925-MB THERMAL RIDGING CHARACTERIZED BY TEMPS APPROACHING 9C
WILL SUPPORT AFTERNOON HIGH TEMPS REACHING THE MIDDLE TO UPPER 50S
ACROSS MANY AREAS. THAT SAID...HAVE ELECTED TO INCREASE TEMPS A
FEW DEGREES WITH UPPER 50S NOW BEING FORECAST ACROSS THE LAKE
PLAIN WHERE DOWNSLOPE COMPRESSIONAL WARMING MAY ALLOW TEMPS TO
APPROACH 60. FROM A CLIMATOLOGICAL STANDPOINT...IF SYR WERE TO
HIT 60 ON THANKSGIVING DAY...IT WILL BE THE FIRST TIME SINCE 2004
WHEN THE MERCURY CLIMBED TO A BALMY 63 DEGREES. DRY CONDITIONS TO
CONTINUE RIGHT THROUGH THANKSGIVING NIGHT WITH OVERNIGHT LOWS
EXPECTED TO FALL INTO THE MIDDLE TO UPPER 30S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
BIG CHANGES ON THE WAY BEGINNING FRI AS A WELL ADVERTISED COLD
FRONT SWINGS THROUGH THE AREA. PRECIP ALONG AND AHEAD OF THE FRONT
WILL BEGIN WORKING THROUGH THE WESTERN ZONES DURING THE LATE
MORNING BEFORE CLEARING THE ENTIRE CWA BY EARLY EVENING. WITH THE
FRONT MOVING THROUGH RAPIDLY...EXPECT PRECIP TOTALS TO GENERALLY
RANGE BELOW TWO TENTHS OF AN INCH. FOR AREAS MAINLY ALONG AND
WEST OF I-81...TEMPS WILL FALL RAPIDLY THROUGH THE MID/LATE
AFTERNOON AS STRONG COLD AIR ADVECTION OVERSPREADS THE REGION IN
THE FRONT/S WAKE.
BIG STORY HOWEVER WILL BE THE RAPID COOL DOWN EXPECTED FOLLOWING
FROPA AND THE REDEVELOPMENT OF LAKE EFFECT SNOW BEGINNING EARLY SAT
MORNING. INITIAL WIND DIRECTION FOLLOWING FROPA WILL FOLLOW A
WESTERLY TRAJECTORY WHICH WILL FAVOR THE SOUTHERN TUG HILL THROUGH
ROUGHLY 12Z ON SAT. FOLLOWING THIS...BOTH NAM AND GFS FCST MODELS
SHOW A SFC TROUGH DROPPING SOUTH IN CYCLONIC FLOW WHICH WILL ALLOW
WINDS TO SHIFT AROUND TO THE NORTHWEST THROUGH THE MORNING. AS
THIS OCCURS...850-MB TEMPS WILL CONTINUE TO COOL WITH VALUES
REACHING NEAR -13C BY 00Z SUN. INSPECTION OF SEVERAL GFS AND NAM
BUFKIT SOUNDINGS REVEALS AN INCREASINGLY FAVORABLE ENVIRONMENT FOR
LAKE EFFECT SNOWS THROUGH THE DAY ON SAT WITH GOOD SATURATION
THROUGH THE FAVORABLE DENDRITIC SNOW GROWTH REGION. THAT
SAID...HAVE DRAWN HIGHEST POPS FROM SOUTHERN ONEIDA COUNTY WEST
THROUGH THE CENTRAL FINGER LAKES TO INCLUDE THE
ITHACA AND SYRACUSE METRO AREAS. FROM THIS VANTAGE
POINT...SEVERAL INCHES OF FRESH LAKE EFFECT SNOWFALL WILL BE
POSSIBLE AS TEMPS STRUGGLE TO REACH THE MID 30S FOR DAYTIME HIGHS.
FOR NOW...IT LOOKS LIKE LAKE SNOWS WILL CONTINUE RIGHT THROUGH SAT
NGT WHICH WILL OBVIOUSLY JUST ADD TO SNOW TOTALS. WOULD NOT BE
SURPRISED IF ADVISORIES EVENTUALLY GET POSTED HOWEVER ITS MUCH TO
EARLY FOR THIS NOW. IN ANY EVENT...WILL HIGHLIGHT SNOW ACCUMULATION
POTENTIAL IN THE HWO TO INCREASE AWARENESS FOR HOLIDAY WEEKEND
TRAVELERS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
345 AM UPDATE...
FORECAST ONLY ADJUSTED SLIGHTLY AS NEEDED FOR COLLABORATION
PURPOSES AND TO ACCOUNT FOR LATEST MODEL TRENDS. THE GENERAL IDEA
REMAINS THE SAME.
850MB RIDGE NEVER REALLY REACHES THE AREA...IT ACTUALLY FLATTENS
TO OBLIVION IN RESPONSE TO PASSING WAVE ON SUNDAY. WAVE EVENTUALLY
YIELDS WARM AIR ADVECTION ALOFT...BUT 850MB TEMPERATURES REMAIN
COLD ENOUGH FOR AT LEAST A MARGINAL CONTINUED LAKE RESPONSE. WARM
FRONT MAY STRUGGLE TO FILL THE DRY LAYER BETWEEN HIGH LEVEL
MOISTURE ASSOCIATED WITH WARM FRONT ALOFT...AND LAKE MOISTURE IN
THE LOWER LEVELS. REGARDLESS THOUGH...LAKE MOISTURE BY ITSELF MAY
BE ENOUGH FOR AT LEAST SCATTERED SNOW SHOWERS TO CONTINUE INTO A
WAYS INTO SUNDAY FOR CENTRAL NY WHILE SHIFTING NORTHWARD /BACKING
WIND/.
MODELS CONTINUE THEIR CONFUSION FOR HOW TO HANDLE LOW PRESSURE
SYSTEM MON NIGHT THROUGH TUE NIGHT PERIOD. ECMWF KEEPS US COLDER
YET IS SO FAR SOUTH WITH TRACK OF LOW /WHICH IS ALSO
WEAKER/...THAT DEPICTED PRECIPITATION SHIELD DOES NOT EVEN MAKE IT
INTO OUR AREA DUE TO STRENGTH OF SURFACE HIGH OVER EASTERN CANADA.
MEANWHILE GFS IS BETTER PHASED AND AMPLIFIED...AND THUS DEVELOPS
STRONGER SURFACE LOW THAT TRACKS UP OHIO VALLEY AND THROUGH THE
REGION. SOME WARMER AIR GETS INVOLVED IN THE GFS SOLUTION...WHICH
MAKES PRECIPITATION TYPE COMPLICATED YET EVENTUALLY TRANSITIONING
TO ALL SNOW SHOWERS IN THE WAKE OF THE POTENTIAL SYSTEM. WITH MUCH
UNCERTAINTY...KEEPING POPS ONLY IN CHANCE RANGE SEEMS BEST AT THIS
TIME.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
06Z UPDATE...
VFR FOR ENTIRE TAF PERIOD...EXCEPT FOR QUESTION OF EARLY MORNING
VALLEY FOG DEVELOPMENT IN KELM...AND SOME MVFR VIS FOR KITH. GREAT
RADIATIONAL COOLING SET UP AND SHARP INVERSION...SUPPORTIVE OF
KELM VALLEY FOG...IS COMPETING WITH VERY ATMOSPHERE /AFTER YET
ANOTHER DAYTIME OF NO PRECIP AND LOW HUMIDITY LEVELS/. RAP MODEL
SOUNDING OVERALL SEEMS TILTED IN FAVOR OF THE DRY AIR MASS...WITH THE
MORE DEGRADED CONDITIONS STAYING TO OUR NORTH AND WEST /AS IS
ALREADY OCCURRING FOR MANY TERMINALS ON THE ONTARIO PENINSULA/...WHERE
HIGHER DEWPOINTS WERE ABLE TO ADVECT IN EARLIER. I HAVE TO RESPECT
THE STILL FAIR SET UP FOR KELM...AND INCLUDED TEMPO IFR 11Z-13Z...BUT
OTHERWISE HELD THE LINE AT MVFR VIS EARLY THIS MORNING. LIGHT
EASTERLY FLOW WILL ALSO YIELD SOME MVFR VIS FOR A TIME EARLY THIS
MORNING. FOR KRME...WILL HAVE TO WATCH FOR POSSIBLE MVFR LIGHT FOG
BUT NOT IN TAF BECAUSE MOST LIKELY SCENARIO IS VFR.
OUTLOOK...
FRI...MVFR POSSIBLE ALONG AND BEHIND SHOWERY COLD FRONT AFTN/EVE.
FRI NGT...MVFR CIGS. LATE IFR VIS POSS KSYR-KRME FROM LAKE -SHSN.
SAT...MVRF/BRIEF IFR FROM LAKE -SHSN...MAINLY CNY TERMINALS.
SUN...RESTRICTIONS PSBL IN SCT SHRA/SHSN.
MON...MAINLY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...CMG
NEAR TERM...CMG/RRM
SHORT TERM...CMG
LONG TERM...MDP
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
105 AM EST THU NOV 22 2012
.SYNOPSIS...
WARM ABOVE AVERAGE TEMPERATURES WILL PREVAIL ACROSS THE REGION ON
THANKSGIVING DAY WITH MANY LOCATIONS EASILY WARMING INTO THE
MIDDLE TO UPPER 50S FOR DAYTIME HIGHS. ABOVE NORMAL TEMPERATURES
WILL QUICKLY COME TO AN END BY FRIDAY AS A STRONG COLD FRONT
SWINGS THROUGH THE REGION. COLD AIR WILL RAPIDLY OVERSPREAD THE
REGION FRIDAY NIGHT AND SATURDAY WITH REDEVELOPING LAKE EFFECT
SNOWS EXPECTED OVER THE UPCOMING WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
1030 PM UPDATE...CURRENT FORECAST REMAINS IN GOOD SHAPE, JUST
LOWERED OVERNIGHT LOWS BY 2-4 DEGREES AS WEAK BOUNDARY LAYER FLOW
WILL PERSIST UNTIL DAYBREAK EVEN ALONG THE LAKE PLAIN. WITH DEW
POINTS CONTINUING TO FALL IN TANDEM WITH SFC TEMPS, DENSE FOG
FORMATION IS NOT EXPECTED.
530 PM UPDATE...CLEAR SKIES AND LIGHT WINDS HAVE ALLOWED TEMPS TO
FALL QUICKLY LATE THIS AFTERNOON. AT PENN YAN AND ELMIRA TEMPS
FELL 10 AND 13 DEGREES RESPECTIVELY DURING THE PAST HOUR. ADJUSTED
TEMP GRIDS TO REFLECT THIS OTHERWISE FORECAST IN GOOD SHAPE WITH
NO OTHER CHANGES.
PREVIOUS DISC...
VISIBLE SATELLITE IMAGERY SHOWING MOSTLY CLEAR SKIES ACROSS THE
REGION THIS AFTERNOON AS SFC RIDGING ASSOCIATED WITH CANADIAN
MARITIMES HIGH PRESSURE CONTINUES TO EXTEND SOUTHWEST OVER OUR
AREA. WITH ABUNDANT SUNSHINE PREVAILING OVERHEAD...TEMPS HAVE WARMED
INTO THE LOWER 50S ACROSS MUCH OF THE AREA WHICH IS ANYWHERE
BETWEEN 5-10 DEGREES ABOVE NORMAL. WITH A DRY AIRMASS IN
PLACE...TEMPS WILL FALL OFF QUICKLY THIS EVENING WITH OVERNIGHT
LOWS EXPECTED TO REACH THE LOWER TO MIDDLE 30S. THE ONLY CONCERN
WITH THE GOING FCST OVERNIGHT WILL BE POSSIBLE FOG FORMATION
TOWARDS MORNING. UPSTREAM OBSERVATIONS THIS MORNING SHOWED AN
EXPANSIVE AREA OF FOG ACROSS THE UPPER MIDWEST WHERE VISIBILITIES
WERE NEAR ZERO ACROSS THE GREATER CHICAGO AREA FOR HRS. THIS MOIST
LOW-LEVEL AIRMASS WILL ADVANCE EAST OVERNIGHT WHERE IT WILL
ENCOUNTER MORE AND MORE DRY AIR WITH FURTHER EASTWARD PROGRESS.
FOR NOW...STATISTICAL GUIDANCE MAKING NO SUGGESTION OF ANY FOG
FORMATION ACROSS OUR AREA HOWEVER EVENING SHIFT WILL HAVE TO
MONITOR TRENDS ACCORDINGLY.
UNSEASONABLY WARM TEMPS TO CONTINUE RIGHT THROUGH THANKSGIVING DAY
WHERE 925-MB THERMAL RIDGING CHARACTERIZED BY TEMPS APPROACHING 9C
WILL SUPPORT AFTERNOON HIGH TEMPS REACHING THE MIDDLE TO UPPER 50S
ACROSS MANY AREAS. THAT SAID...HAVE ELECTED TO INCREASE TEMPS A
FEW DEGREES WITH UPPER 50S NOW BEING FORECAST ACROSS THE LAKE
PLAIN WHERE DOWNSLOPE COMPRESSIONAL WARMING MAY ALLOW TEMPS TO
APPROACH 60. FROM A CLIMATOLOGICAL STANDPOINT...IF SYR WERE TO
HIT 60 ON THANKSGIVING DAY...IT WILL BE THE FIRST TIME SINCE 2004
WHEN THE MERCURY CLIMBED TO A BALMY 63 DEGREES. DRY CONDITIONS TO
CONTINUE RIGHT THROUGH THANKSGIVING NIGHT WITH OVERNIGHT LOWS
EXPECTED TO FALL INTO THE MIDDLE TO UPPER 30S.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
BIG CHANGES ON THE WAY BEGINNING FRI AS A WELL ADVERTISED COLD
FRONT SWINGS THROUGH THE AREA. PRECIP ALONG AND AHEAD OF THE FRONT
WILL BEGIN WORKING THROUGH THE WESTERN ZONES DURING THE LATE
MORNING BEFORE CLEARING THE ENTIRE CWA BY EARLY EVENING. WITH THE
FRONT MOVING THROUGH RAPIDLY...EXPECT PRECIP TOTALS TO GENERALLY
RANGE BELOW TWO TENTHS OF AN INCH. FOR AREAS MAINLY ALONG AND
WEST OF I-81...TEMPS WILL FALL RAPIDLY THROUGH THE MID/LATE
AFTERNOON AS STRONG COLD AIR ADVECTION OVERSPREADS THE REGION IN
THE FRONT/S WAKE.
BIG STORY HOWEVER WILL BE THE RAPID COOL DOWN EXPECTED FOLLOWING
FROPA AND THE REDEVELOPMENT OF LAKE EFFECT SNOW BEGINNING EARLY SAT
MORNING. INITIAL WIND DIRECTION FOLLOWING FROPA WILL FOLLOW A
WESTERLY TRAJECTORY WHICH WILL FAVOR THE SOUTHERN TUG HILL THROUGH
ROUGHLY 12Z ON SAT. FOLLOWING THIS...BOTH NAM AND GFS FCST MODELS
SHOW A SFC TROUGH DROPPING SOUTH IN CYCLONIC FLOW WHICH WILL ALLOW
WINDS TO SHIFT AROUND TO THE NORTHWEST THROUGH THE MORNING. AS
THIS OCCURS...850-MB TEMPS WILL CONTINUE TO COOL WITH VALUES
REACHING NEAR -13C BY 00Z SUN. INSPECTION OF SEVERAL GFS AND NAM
BUFKIT SOUNDINGS REVEALS AN INCREASINGLY FAVORABLE ENVIRONMENT FOR
LAKE EFFECT SNOWS THROUGH THE DAY ON SAT WITH GOOD SATURATION
THROUGH THE FAVORABLE DENDRITIC SNOW GROWTH REGION. THAT
SAID...HAVE DRAWN HIGHEST POPS FROM SOUTHERN ONEIDA COUNTY WEST
THROUGH THE CENTRAL FINGER LAKES TO INCLUDE THE
ITHACA AND SYRACUSE METRO AREAS. FROM THIS VANTAGE
POINT...SEVERAL INCHES OF FRESH LAKE EFFECT SNOWFALL WILL BE
POSSIBLE AS TEMPS STRUGGLE TO REACH THE MID 30S FOR DAYTIME HIGHS.
FOR NOW...IT LOOKS LIKE LAKE SNOWS WILL CONTINUE RIGHT THROUGH SAT
NGT WHICH WILL OBVIOUSLY JUST ADD TO SNOW TOTALS. WOULD NOT BE
SURPRISED IF ADVISORIES EVENTUALLY GET POSTED HOWEVER ITS MUCH TO
EARLY FOR THIS NOW. IN ANY EVENT...WILL HIGHLIGHT SNOW ACCUMULATION
POTENTIAL IN THE HWO TO INCREASE AWARENESS FOR HOLIDAY WEEKEND
TRAVELERS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
130 PM UPDATE...CLD AIR SETS IN BHND FRONTAL PASSAGE LATE IN THE
WEEK, CONTINUING THRU THE WEEKEND. H8 TEMPS DROP DOWN TO BTWN -10C
TO -12C LVG MODERATE LK INSTABILITY IN ITS WAKE. FLOW ALIGNS FM
310-320 DEGREES WITH FINGER LKS AREA UNDER THE GUN FOR CONTD LK
EFFECT SNOW THRU SUN AFTN. APPEARS AS THO WINDS SHIFT ARND TO THE
SOUTHWEST, MVG SNOW SHOWERS NORTH OF THE CWA SUN NGT.
MED RANGE MODELS AGREE ON S/WV DROPPING INTO THE INTERMOUNTAIN
STATES EARLY NEXT WEEK. THIS WL INDUCE SFC LOW DVLPMNT BY 00Z TUE
IN VICINITY OF MID-MS VLY. 00Z EURO IS QUICKER TO MV THIS SFC LOW
NORTH TWD THE AREA BY ABOUT 12 HRS. EURO BRINGS IT UP TO THE WEST
OF OUR AREA WITH RAIN OR SNOW EXPECTED DRG THE DAY ON TUESDAY. 12Z
GFS SUPPRESSES THE LOW FURTHER TO THE SOUTH, THOUGH H8 TEMPS RISE
ABV 0C ACRS PORTIONS OF OUR AREA. THUS HV GONE WITH CHC POPS THRU
12Z WED WITH A MIX OF RAIN OR SNOW, TOO EARLY TO SAY AT THIS
POINT.
TEMPS WL BE MORE TYPICAL OF VALUES EXPECTED FOR LATE NOVEMBER.
HIGHS IN THE U30S AND LOWS IN THE MID-20S.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
06Z UPDATE...
VFR FOR ENTIRE TAF PERIOD...EXCEPT FOR QUESTION OF EARLY MORNING
VALLEY FOG DEVELOPMENT IN KELM...AND SOME MVFR VIS FOR KITH. GREAT
RADIATIONAL COOLING SET UP AND SHARP INVERSION...SUPPORTIVE OF
KELM VALLEY FOG...IS COMPETING WITH VERY ATMOSPHERE /AFTER YET
ANOTHER DAYTIME OF NO PRECIP AND LOW HUMIDITY LEVELS/. RAP MODEL
SOUNDING OVERALL SEEMS TILTED IN FAVOR OF THE DRY AIR MASS...WITH THE
MORE DEGRADED CONDITIONS STAYING TO OUR NORTH AND WEST /AS IS
ALREADY OCCURRING FOR MANY TERMINALS ON THE ONTARIO PENINSULA/...WHERE
HIGHER DEWPOINTS WERE ABLE TO ADVECT IN EARLIER. I HAVE TO RESPECT
THE STILL FAIR SET UP FOR KELM...AND INCLUDED TEMPO IFR 11Z-13Z...BUT
OTHERWISE HELD THE LINE AT MVFR VIS EARLY THIS MORNING. LIGHT
EASTERLY FLOW WILL ALSO YIELD SOME MVFR VIS FOR A TIME EARLY THIS
MORNING. FOR KRME...WILL HAVE TO WATCH FOR POSSIBLE MVFR LIGHT FOG
BUT NOT IN TAF BECAUSE MOST LIKELY SCENARIO IS VFR.
EXTENDED OUTLOOK...
FRI...MVFR POSSIBLE ALONG AND BEHIND SHOWERY COLD FRONT AFTN/EVE.
FRI NGT...MVFR CIGS. LATE IFR VIS POSS KSYR-KRME FROM LAKE -SHSN.
SAT...MVRF/BRIEF IFR FROM LAKE -SHSN...MAINLY CNY TERMINALS.
SUN...RESTRICTIONS PSBL IN SCT SHRA/SHSN.
MON...MAINLY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...CMG
NEAR TERM...CMG/RRM
SHORT TERM...CMG
LONG TERM...PVN
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1241 AM EST THU NOV 22 2012
.SYNOPSIS...
HIGH PRESSURE WILL KEEP WARM AND DRY CONDITIONS ACROSS THE REGION
THROUGH THANKSGIVING. A COLD FRONT WILL MOVE THROUGH THE AREA
FRIDAY MORNING. TEMPERATURES WILL FALL FRIDAY AFTERNOON AND BE
WELL BELOW NORMAL OVER THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
FOR THE EVENING UPDATE ADDED PATCHY TO AREAS OF FOG MAINLY FOR
THE NORTHWESTERN PORTIONS OF THE FORECAST AREA AFTER MIDNIGHT
TONIGHT. TEMP/DEWPOINT SPREADS ARE NARROWING RAPIDLY THIS EVENING
ACROSS THESE AREAS WITH FOG ALREADY DEVELOPING JUST TO OUR
NORTHWEST. THIS TREND HAS BEEN INDICATED WELL BY THE RAP SURFACE RH
FIELDS THIS AFTERNOON AND THEREFORE IS BEING FOLLOWED FOR THE FOG
FORECAST FOR TONIGHT. OTHERWISE MADE NO ADJUSTMENTS TO THE
PREVIOUS FORECAST EXCEPT ADDING A FEW CIRRUS TO THE SKY GRIDS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
SOUTHERLY WINDS WILL OCCUR BETWEEN RETREATING HIGH PRESSURE AND AN
ADVANCING COLD FRONT THURSDAY AND THURSDAY EVENING. THIS WILL LEAD
TO WELL ABOVE NORMAL TEMPERATURES ONCE AGAIN. HIGH CLOUDS WILL
START STREAMING INTO THE REGION DURING THIS PERIOD.
THE COLD FRONT WILL MOVE INTO WESTERN SECTIONS VERY LATE THURSDAY
NIGHT AND CROSS THE REST OF THE FORECAST AREA FRIDAY MORNING.
THERE WILL BE SHOWERS WITH THE COLD FRONT. BUT THERE IS SOME
UNCERTAINTY ABOUT COVERAGE OF MEASURABLE RAIN. SO HAVE GONE HIGH
CHANCE AND LOW LIKELY FOR THE REGION LATE THURSDAY NIGHT AND
FRIDAY MORNING. SHOWERS WILL CLEAR OUT BY MIDDAY FRIDAY WITH
CLOUDS DECREASING. TEMPERATURES SHOULD STAY RATHER WARM UNTIL
FRONTAL PASSAGE EXCEPT FOR FAR EASTERN/SOUTHEASTERN COUNTIES WHERE
READINGS MAY DROP OFF EARLY THURSDAY NIGHT. LOOKS LIKE A SITUATION
WHERE THERE COULD BE 13Z LOWS AND 12Z HIGHS IN MANY LOCATIONS WITH
READINGS FALLING THROUGH THE REST OF FRIDAY. WINDS WILL BE GUSTY
BEHIND THE COLD FRONT WITH WIND CHILL VALUES DROPPING INTO THE
UPPER 20S TO MID 30S BY LATE IN THE DAY.
WINDS WILL DIMINISH SOMEWHAT FRIDAY NIGHT. ADDITIONAL CLOUD COVER
MAY SPREAD INTO THE REGION WITH COLD AIR ADVECTION AND CYCLONIC
FLOW OVER THE GREAT LAKES. FELT THAT GFS MOS LOWS LOOKED MORE
REASONABLE IN THIS SCENARIO.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
COLD AIR MASS WILL BE IN PLACE ACROSS THE AREA ON SATURDAY WITH HIGH
TEMPERATURES ONLY IN THE MIDDLE 30S. WITH WINDS OFF OF LAKE
MICHIGAN ON SATURDAY SOME LIGHT LAKE EFFECT SNOW SHOWERS WILL BE
POSSIBLE ACROSS NORTHERN PORTIONS OF THE FA. H8 WINDS WILL BECOME
MORE WESTERLY SATURDAY EVENING AND PRECIPITATION CHANCES WILL COME
TO AN END ACROSS THE FA. CLOUD COVER WILL DECREASE ACROSS THE AREA
SATURDAY NIGHT ALLOWING TEMPERATURES TO DROP DOWN INTO THE LOW 20S
ACROSS MOST LOCATIONS. WARMER AIR WILL GRADUALLY START TO WORK INTO
THE AREA LATE DURING THE OVERNIGHT SATURDAY NIGHT AND THIS SHOULD
HELP TO KEEP TEMPERATURES FROM FALLING INTO THE TEENS. TEMPERATURES
CLIMB INTO THE 40S ON SUNDAY ACROSS THE AREA WITH SW FLOW HOWEVER
THESE VALUES ARE STILL BELOW NORMAL FOR THIS TIME OF YEAR.
THE MODELS START TO DIVERGE WITH THE STORM SYSTEM BEGINNING TO
IMPACT THE AREA ON MONDAY. MODELS HAVE SHOWN QUITE A BIT OF RUN TO
RUN INCONSISTENCY WITH THIS FEATURE. THE LATEST 12Z ECMWF HAS
SHIFTED THE LOW QUITE A BIT FURTHER SOUTH FROM THE PREVIOUS MODEL
SOLUTIONS AND HAVE DECIDED NOT TO JUMP ON THIS LATEST RUN JUST YET.
INSTEAD...WENT WITH A 12Z GFS 00Z ECMWF BLEND. PRECIPITATION WILL
BEGIN TO MOVE INTO THE AREA ON MONDAY WITH A GREATER COVERAGE IN
PRECIPITATION EXPECTED MONDAY EVENING INTO TUESDAY. PRECIPITATION
WILL GENERALLY BE IN THE FORM OF RAIN THROUGH THE DAYTIME HOURS ON
TUESDAY EXCEPT FOR A LITTLE SNOW THAT MAY MIX IN AT TIMES ACROSS THE
NORTH MONDAY INTO MONDAY NIGHT. WITH THE 12Z GFS 00Z ECMWF BLEND
HAVE THE AREA OF LOW PRESSURE MOVING ALONG AND JUST NORTH OF THE
INTERSTATE 71 CORRIDOR ON TUESDAY. COLDER AIR WILL QUICKLY WORK
INTO THE AREA TUESDAY NIGHT AND ANY RESIDUAL PRECIPITATION WILL
BEGIN TO CHANGE OVER TO SNOW ACROSS THE REGION. DRY CONDITIONS WILL
RETURN TO THE AREA BY WEDNESDAY MORNING.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
HIGH PRESSURE CENTERED OVER THE REGION ATTM WILL SLIP EAST TODAY.
LIGHT WINDS AND CLEAR SKIES WILL ALLOW SOME FOG FORMATION. KEPT
FOG AT THE FOGGIER LOCATIONS...LUK AND ILN. ALLOWED LUK TO FALL TO
IFR IN FOG...BUT KEPT ILN MVFR ATTM.
H5 RIDGE ALSO OVER THE REGION WILL BREAK DOWN TODAY IN RESPONSE TO
A S/W KICKING OUT OF THE PLAINS. HIGH LEVEL MOISTURE WILL BEGIN
TO INCREASE DURING THE AFTN HOURS. AC DECK IS EXPECTED T0 WORK IN
AFT 00Z.
CDFNT SWINGING UP THE OH VALLEY WILL PUSH 4-5KFT CIGS INTO CVG AFT
06Z...WITH SCT SHRA AFT 10Z.
OUTLOOK...MVFR CEILINGS AND VISIBILITIES POSSIBLE FRIDAY. MVFR
CEILINGS POSSIBLE SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...LATTO
SHORT TERM...
LONG TERM...NOVAK
AVIATION...SITES
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1045 PM CST WED NOV 21 2012
.DISCUSSION...
STILL A LITTLE MIXY WITH SOUTHWESTERLY LOW LEVEL JET OVER EASTERN
PART OF THE AREA. THIS HOLDING TEMPERATURES UP THIS EVENING...WITH
READINGS STILL IN THE MID 50S TO LOWER 60S AS OF 03Z. MODELS DO NOT
HAVE A GREAT GRASP ON THIS...WITH RAP THE CLOSEST THOUGH STILL A FEW
DEGREES SHY AT 03Z. TREND IN THIS MODEL SEEMS REASONABLE THOUGH...
WITH SLOW FALL AHEAD OF PRE-FRONTAL TROUGH...WHICH WILL TURN WINDS
MORE WESTERLY AND SOMEWHAT LIGHTER OVERNIGHT. SHOULD SEE GREATER
FALL AFTER THIS TROUGH PASSAGE...AND WITH COLD ADVECTION BEGINNING
TO PUSH INTO WESTERN PARTS OF THE CWA PRIOR TO DAYBREAK...WILL LET
GOING LOWS RIDE WITH MINIMAL CHANGES. UPDATED GRIDS/PFM HAVE BEEN
SENT.
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
MAINLY VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. SOUTHERLY
WINDS OVERNIGHT WILL TRANSITION TO NORTHWESTERLY AND INCREASE EARLY
ON THURSDAY...WITH GUSTS OF 30 TO 40 KTS LIKELY BY LATE MORNING AND
AFTERNOON. REMOVED LLWS AT KSUX AS GUSTY SURFACE WINDS ARE
CURRENTLY LIMITING SHEAR...HOWEVER IF SURFACE WINDS ARE ABLE TO DROP
OFF OVER THE NEXT COUPLE HOURS LLWS MIGHT NEED TO BE
REINTRODUCED...AS STILL SEEING CLOSE TO A 45 KT JET NEAR 1K FEET.
SHOULD SEE SOME STRATUS FORM BEHIND THE FRONT TOMORROW AS WELL.
CURRENTLY THINKING ANY MVFR CIGS STAY NORTH OF OUR CWA...ALTHOUGH
WILL HAVE TO WATCH KHON AND TO A LESSER EXTENT KFSD...AS THEY COULD
SEE A BRIEF PERIOD OF MVFR CIGS RIGHT BEHIND THE FRONT LATE TOMORROW
MORNING INTO THE EARLY AFTERNOON HOURS...BEFORE DRYING AND CLEARING
TAKES PLACE. WINDS WILL REMAIN GUSTY THROUGH THE EVENING HOURS...BUT
SHOULD DROP A TAD. BUT AS A SECONDARY PUSH OF COLD AIR MOVES
THROUGH...WE SHOULD SEE WINDS KICK UP A NOTCH WITH GUSTS BACK AROUND
35 KTS LATER IN THE EVENING INTO THE OVERNIGHT. /CHENARD
&&
.PREV DISCUSSION.../ISSUED AT 241 PM CST/
BRISK SOUTH SOUTHWESTERLY FLOW WILL CONTINUE ACROSS MUCH OF THE AREA
TONIGHT WITH THE APPROACH OF A SURFACE TROUGH FROM THE WEST. THIS
WILL ALLOW FOR WINDS TO STAY UP OVERNIGHT...MORE SO IN THE
EAST...AND IT WILL BE A MILD NIGHT WITH LOWS PRIMARILY IN THE 40S.
THE SURFACE TROUGH/FRONTAL BOUNDARY WILL SWING THROUGH THE AREA ON
THURSDAY...AND WITH STRONG COLD AIR ADVECTION/STEEP LOW LEVEL LAPSE
RATES/WINDS GENERALLY 40 TO 45 KTS AT THE TOP OF THE MIXED LAYER/AND
A TIGHTENING GRADIENT IT WILL BE A WINDY DAY...AND EXPANDED THE WIND
ADVISORY OVER THE ENTIRE CWA. WHILE THE ADVISORY WILL BE MARGINAL IN
SOME AREAS...AND STRONGEST WINDS MAY ONLY PERSIST FOR 2 OR 3 HOURS
WITH THE FRONTAL PASSAGE...FOR THE SAKE OF SIMPLICITY AND
COORDINATION WITH SURROUNDING OFFICES ELECTED TO INCLUDE THE ENTIRE
AREA AS CRITERIA IS EXPECTED TO BE CLOSE ENOUGH. WHILE THE COLDEST
AIR WILL NOT COME IN UNTIL THURSDAY NIGHT...WITH 925 MB TEMPERATURES
PROGGED TO BE A GOOD 10 TO 15 DEGREES C COOLER ON THURSDAY AFTERNOON
OVER TODAY...WILL HAVE HIGHS RANGING FROM THE UPPER 40S TO
MID 50S ACROSS THE AREA...THOUGH IT WILL OBVIOUSLY FEEL COLDER WHEN
THE WINDS ARE FACTORED IN.
A STRONG SURGE OF COLD AIR WILL MOVE SOUTH ON THURSDAY NIGHT ALONG
WITH GUSTY NORTHWEST WINDS. MODELS IN PRETTY GOOD AGREEMENT WITH THE
AMOUNT OF COOLING...JUST SOME MINOR DIFFERENCES ON THE TIMING OF THE
FRONT. THE NAM SEEMS TO HANDLE THESE LOW LEVEL FRONTAL FEATURES BEST
THIS TIME OF YEAR SO USED THAT TO ACCOUNT FOR THE SOMEWHAT NON
DIURNAL NATURE OF TEMPERATURES AS THEY DROP THROUGH THE EARLY
MORNING OF FRIDAY BEFORE SLOWLY RISING THROUGH THE DAY. LOWS WILL BE
MODERATED A BIT BY THE STRONG FLOW SO WENT CLOSEST TO THE CONSRAW
OUTPUT WHICH HANDLES WINDY NIGHTS THE BEST...SO MAINLY LOWER TO MID
20S FOR LOWS. HIGH TEMPERATURES FRIDAY WILL NOT REBOUND MUCH AS COLD
ADVECTION CONTINUES AND CLOUDS IN THE EAST ARE SLOW TO ERODE. MAINLY
AIMING FOR 250 TO 30 IN THE EAST AND 30 TO 35 IN THE WEST.
FRIDAY NIGHT INTO SATURDAY WILL SEE A FAST MOVING SURFACE HIGH
PRESSURE MOVE THROUGH WITH BREEZY SOUTHERLY FLOW DEVELOPING ON
SATURDAY. TWEAKED LOWS DOWN JUST A TOUCH IN THE EASTERN CWA AND LEFT
THEM ABOUT AS IS IN THE WESTERN CWA. WITH THE RETURN FLOW SETTING UP
IN THE FAR SOUTH AND WEST CWA ALSO HAVE GRADUALLY WARMING
TEMPERATURES IN THOSE AREAS THROUGH SUNRISE. BY SATURDAY THIS STRONG
SOUTHERLY FLOW WILL BE IN PLACE WITH A FAIRLY STRONG THERMAL
GRADIENT DEVELOPING ACROSS THE CWA. EXPECTING TEMPERATURES TO
STRUGGLE A BIT IN THE EAST WHERE SOUTHERLY WINDS WILL BE SLOW TO SET
UP...SO ONLY MID 30S. IN THE SOUTHWEST CWA A SURGE OF WARMER AIR
SHOULD ALLOW TEMPERATURES TO BUMP UP INTO THE LOWER 50S.
IN THE LATTER PERIODS(SUN/WED)...A TROUGH OF LOW PRESSURE WILL DIG
INTO THE CENTRAL ROCKIES SUNDAY AFTERNOON THEN SPREAD ACROSS THE
CENTRAL PLAINS SUNDAY NIGHT INTO MONDAY. WHILE THERE WILL BE A SMALL
CHANCE FOR LIGHT SNOW DURING THIS TIME...WITH SO MUCH NORTHWEST JET
ENERGY UPSTREAM FEEL THAT THE WAVE MAY DIG A LITTLE FARTHER SOUTH
THAN MODELS CURRENTLY PROJECT SO DO NOT PLAN ON INCREASING
PROBABILITIES FOR MEASURABLE SNOWFALL. IF THE WAVE DOES DIVE A
LITTLE FARTHER SOUTHWEST ON SUNDAY THE AMOUNT OF WARM AIR THAT MAKES
IT THIS FAR NORTH WILL BE MINIMAL WITH A NORTH TO NORTHEAST WIND
DEVELOPING THROUGH THE DAY. WILL CONTINUE TO KEEP HIGHS FAIRLY COOL
BUT SEASONAL FROM THE UPPER 30S NORTH TO THE MID 40S SOUTH. AS THE
WAVE PASSES ON SUNDAY NIGHT COLDER AIR WILL POUR INTO THE REGION
SETTING UP A FAIRLY COLD MONDAY THROUGH THURSDAY TIME PERIOD. WILL
CONTINUE TO LEAN TOWARDS THE MORE CONSISTENT ECMWF WHICH BUILDS THE
HIGH PRESSURE SOUTH AND IS MORE STUBBORN ABOUT ALLOWING WARM AIR TO
SURGE NORTHEAST AS A WEAK WAVE PASSES ON TUESDAY NIGHT INTO
WEDNESDAY. /08
&&
.FIRE WEATHER.../ISSUED AT 333 PM CST/
THANKSGIVING DAY WILL SEE VERY STRONG NORTHWEST WINDS DEVELOP DURING
THE DAY AND WITH VERY DRY CONDITIONS A VERY HIGH FIRE DANGER WILL BE
IN PLACE. THE STRONGEST WINDS WILL BE IN CENTRAL SOUTH DAKOTA DOWN
THE MISSOURI RIVER VALLEY THROUGH EARLY AFTERNOON...THEN TRANSITION
INTO EASTERN SOUTH DAKOTA...SOUTHWEST MINNESOTA AND NORTHWEST IOWA
FROM EARLY AFTERNOON INTO THE EVENING.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...WIND ADVISORY FROM NOON TO 6 PM CST THURSDAY FOR IAZ001>003-
012>014-020>022-031-032.
MN...WIND ADVISORY FROM NOON TO 6 PM CST THURSDAY FOR MNZ071-072-080-
081-089-090-097-098.
NE...WIND ADVISORY FROM 9 AM TO 6 PM CST THURSDAY FOR NEZ013.
WIND ADVISORY FROM NOON TO 6 PM CST THURSDAY FOR NEZ014.
SD...WIND ADVISORY FROM 9 AM TO 6 PM CST THURSDAY FOR SDZ038-050-052-
053-057>060-063>066-068>070.
WIND ADVISORY FROM NOON TO 6 PM CST THURSDAY FOR SDZ039-040-
054>056-061-062-067-071.
&&
$$
AREA FORECAST DISCUSSION
NWS AMARILLO TX
1119 PM CST WED NOV 21 2012
.AVIATION...
06Z TAF CYCLE
UPPER TROUGH TO PUSH THROUGH THE PANHANDLES BETWEEN 12Z AND 18Z
THURSDAY WITH NORTHWESTERLY UPPER FLOW BEHIND THE DEPARTING UPPER
TROUGH LATE THURSDAY AND THURSDAY NIGHT. VFR CONDITIONS WITH
CONSIDERABLE MID AND HIGH LEVEL CLOUDINESS TONIGHT...AND CLEAR TO
SCATTERED HIGH LEVEL CLOUDS BY THURSDAY AFTERNOON AND THURSDAY NIGHT.
LOW LEVEL SOUTHERLY JET OVER THE PANHANDLES TONIGHT WILL ALLOW FOR
GUSTY SOUTHERLY WINDS 15 TO 25 KNOTS WITH OCCASIONAL HIGHER
GUSTS...THEN COLD FRONT MOVES THROUGH THE GUYMON AND DALHART TAF
SITES AROUND 13Z TO 15Z THURSDAY SHIFTING THE WINDS TO NORTHERLY 15
TO 25 KNOTS WITH HIGHER GUSTS. COLD FRONT MOVES THROUGH THE AMARILLO
TAF SITE BETWEEN AROUND 16Z AND 18Z THURSDAY WITH WINDS BECOMING
NORTHERLY 15 TO 25 KNOTS WITH HIGHER GUSTS. NORTHERLY WINDS GRADUALLY
DIMINISH BETWEEN 21Z THURSDAY AND 02Z FRIDAY TO AROUND 10 TO 20
KNOTS UNTIL 06Z FRIDAY.
SCHNEIDER
&&
.PREV DISCUSSION... /ISSUED 959 PM CST WED NOV 21 2012/
UPDATE...
QUICK UPDATE TO TWEAK OVERNIGHT WINDS...TEMPS...AND DEWPOINTS UPWARD BASED
ON CURRENT TRENDS.
KB
PREV DISCUSSION... /ISSUED 518 PM CST WED NOV 21 2012/
AVIATION...
00Z TAF CYCLE
UPPER TROUGH WILL MOVE ACROSS THE TEXAS AND OKLAHOMA PANHANDLES
TONIGHT PRODUCING CONSIDERABLE MID AND HIGH LEVEL CLOUDINESS AND
USHERING IN A COLD FRONT THANKSGIVING DAY MORNING. VFR CONDITIONS ARE
EXPECTED ALONG WITH SOUTHERLY WINDS 15 TO 20 KNOTS WITH SOME HIGHER
GUSTS POSSIBLE TONIGHT...THEN WINDS SHIFTING TO THE NORTHWEST AND
NORTH 15 TO 25 KNOTS WITH HIGHER GUSTS AFTER 14Z TO 17Z THANKSGIVING
DAY. WIND SPEEDS ARE EXPECTED TO GRADUALLY DIMINISH AFTER 20Z TO 22Z
THANKSGIVING DAY TO AROUND 15 KNOTS.
SCHNEIDER
PREV DISCUSSION... /ISSUED 415 PM CST WED NOV 21 2012/
DISCUSSION...
CONTINUED DRY CONDITIONS AND PERIODIC FRONTAL PASSAGES HIGHLIGHT THE
FORECAST PERIOD.
SOUTHWESTERLY WINDS AND CLOUD COVER HAVE INCREASED TODAY IN ADVANCE
OF A SHORTWAVE TROUGH NOW EJECTING THROUGH THE AMBIENT SOUTHWESTERLY
FLOW ALOFT. WHILE MOST OF THE FORCING/ASCENT AND MEANINGFUL RAIN
CHANCES ASSOCIATED WITH THIS FEATURE WILL REMAIN WELL SOUTH OF THE
AREA...SOME ENHANCED VORTICITY/DEEPENING OF THE TROUGH HAS EMERGED THIS
AFTERNOON OVER CENTRAL NEW MEXICO. ISOLATED HIGH-BASED CONVECTION HAS
DEVELOPED NEAR ROSWELL. ALL NWP SOLUTIONS MINIMIZE PROSPECTS FOR
PRECIPITATION IN THE PANHANDLES AS THIS TRANSLATES OVER THE REGION
TONIGHT. ONLY THE RAP DEPICTS THE SMALLEST HINT OF QPF OVER THE
SOUTHWESTERN PANHANDLE. THUS WE HAVE MAINTAINED A DRY FORECAST WITH
GRIDDED POPS AT/BELOW 10 PERCENT.
A FRONT IS EXPECTED TO PUSH ACROSS THE PANHANDLES AFTER 12-15Z
THURSDAY IN WAKE OF THE PASSING SHORTWAVE TROUGH AXIS. 3-HR PRESSURE
RISES AROUND 4 MB OVER KANSAS WILL SUPPORT POST FRONTAL WINDS OF 15
TO 25 MPH...ESPECIALLY OVER THE OKLAHOMA PANHANDLE AND THE NORTHERN
TEXAS PANHANDLE. ALL INDICATIONS OF SUFFICIENT LIFT/MOISTURE TO
SUPPORT CONVECTION ALONG THE FRONT ARE DISPLACED WELL EAST AND SOUTH
OF THE REGION.
A 1035-1037 MB CONTINENTAL SURFACE HIGH WILL PUSH SOUTHWARD THROUGH
THE PLAINS IN WAKE OF THE FRONT. THIS WILL RESULT IN NOTABLY COOLER
TEMPERATURES /SOME 5 DEGREES BELOW SEASONAL AVERAGES/ BY FRIDAY. THE
COOL SURFACE RIDGE WILL TRANSLATE SOUTHEAST TOWARD THE LOWER
MISSISSIPPI VALLEY...LENDING TOWARD TEMPERATURE MODERATION OVER THE
PANHANDLES THROUGH THE WEEKEND. THIS AS LOW AMPLITUDE RIDGING OVER
THE WEST RESULTS IN MODEST NORTHWESTERLY FLOW OVER THE CENTRAL/SOUTHERN
PLAINS AND LEE TROUGHING.
ATTENTION THEN SHIFTS TOWARD A SHORTWAVE TROUGH AND ASSOCIATED FRONTAL
PASSAGE EARLY NEXT WEEK. THE INITIAL FRONTAL PASSAGE WILL OCCUR DURING
THE LATE SUNDAY/EARLY MONDAY TIMEFRAME...AND MAY RESULT IN PROBLEMATIC
TEMPERATURE FORECASTS INITIALLY. THE FRONT WILL FINALLY PUSH SOLIDLY
THROUGH BY LATE MONDAY AS THE APPROACHING SHORTWAVE TROUGH AMPLIFIES
IN NORTHWESTERLY FLOW. SOME SOLUTIONS GENERATE LIGHT QPF IN PROXIMITY
TO THE NORTHERN AND EASTERN PANHANDLES...BUT CONFIDENCE IN SUFFICIENT
FORCING/MOISTURE IS NOT HIGH AND THE CURRENT DRY FORECAST CONTINUES TO
APPEAR VALID.
FIRE WEATHER...
ONGOING ELEVATED FIRE WEATHER OVER THE WESTERN AND CENTRAL OKLAHOMA
PANHANDLE AND NORTHWESTERN TEXAS PANHANDLE WILL DIMINISH BY EARLY
EVENING. CONCERNS FOR ELEVATED CONDITIONS WILL AGAIN EXIST THURSDAY...
AS POST FRONTAL WINDS INCREASE INTO THE 15 TO 20 MPH RANGE AND AFTERNOON
HUMIDITY MINIMA DROP TOWARDS 15 PERCENT AGAIN OVER THE WESTERN OKLAHOMA
PANHANDLE AND THE NORTHWESTERN TEXAS PANHANDLE. OTHERWISE...ELEVATED
OR CRITICAL CONDITIONS ARE NOT ANTICIPATED THROUGH THE REMAINDER OF THE
PERIOD.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
11/08
AREA FORECAST DISCUSSION
NWS GOODLAND KS
418 AM MST THU NOV 22 2012
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 226 AM MST THU NOV 22 2012
MAIN FORECAST ISSUE WILL BE THE WINDS TODAY WITH MINOR CONCERNS OF
HOW MUCH IT COOLS OFF THROUGH TOMORROW AND HOW MUCH THE WARM UP IS
ON SATURDAY. SATELLITE SHOWING AN AMPLIFIED PATTERN OVER THE PACIFIC
WITH A LESS AMPLIFIED MORE PROGRESSIVE FLOW FROM NORTH AMERICA INTO
THE ATLANTIC. COLD FRONT IS APPROACHING THE AREA FROM THE NORTHWEST.
AT JET LEVEL...THE ECMWF WAS DOING A LITTLE BETTER THAN THE UKMET...
CANADIAN...AND NAM ON THE JET SEGMENT ASSOCIATED WITH THE NORTHERN
STREAM SYSTEM. THE GFS FOLLOWED BY THE SREF WAS TOO STRONG WITH THE
JET BEHIND THE INCOMING TROUGH. AT MID LEVELS THE MODELS INITIALIZED
FINE WITH NO BIG PROBLEMS. THE RUC AND NAM WERE DOING BEST ON THE
WIND/PRESSURE FIELD. LOW LEVEL THERMAL GUIDANCE WAS CLOSE TO EACH
OTHER AND REALITY.
TODAY/TONIGHT...SATELLITE AND UPPER AIR IS SHOWING A VERY DRY AND
SUBSIDENT AIR MASS BEHIND THE SYSTEM MOVING ALONG THE CANADIAN AND
UNITED STATES BORDER.
SURFACE TO 850 MB WINDS ARE HIGHEST AT 12Z AND THEN DECREASE BY 18Z.
SOME PLACES COULD REACH 35 KNOT GUSTS. HIGHEST OBSERVED 3 HOUR
PRESSURE RISES HAVE OCCURRED MUCH FURTHER NORTH AND ARE NOT ANYTHING
OUT OF THE ORDINARY AT THIS TIME. FORECAST PRESSURE GRADIENT AND 3
HOUR PRESSURE RISES ARE HIGHEST EARLY ON AND DECREASE BY 18Z. IN FACT
BOTH WOULD INDICATE A QUICK BURST OF THE STRONGEST WINDS RIGHT AFTER
THE FROPA AND SUPPORT WINDY CONDITIONS BUT NOT QUITE AT ADVISORY
CRITERIA. STRONGEST SUBSIDENCE LOOKS TO BE NEAR THE NORTHERN PORTION
OF OUR AREA. THAT AND OTHER GUIDANCE WOULD SUPPORT THE HIGHEST WINDS
TO BE IN THE NORTHERN PORTION OF THE AREA AND MAYBE SOME OF THE
SOUTHWEST. SO HAVE CONTINUE TO HAVE WINDS JUST UNDER ADVISORY
CRITERIA WITH THE NORTH THE CLOSEST.
HIGH LEVEL CLOUDS WILL BE THICKEST EARLY DUE TO THE RIGHT REAR
QUADRANT OF THE MID AND UPPER JET BEING CLOSE. OVERNIGHT
TEMPERATURES HAVE BEEN ALL OVER THE PLACE AS THE PREFRONTAL TROUGH
WORKS ITS WAY ACROSS. FRONT LOOKS TO PUSH THROUGH THE AREA EARLY
TODAY. NWP IS WARMER THAN IT WAS YESTERDAY AND IN CLOSE AGREEMENT.
MADE ONLY SLIGHT ADJUSTMENTS.
GUIDANCE THIS MORNING KEEPS THE WINDS STRONGER FOR TONIGHT THAN THE
IT DID YESTERDAY DUE TO THE SURFACE RIDGE MOVING IN A LITTLE
SLOWER. SO WARMED UP THE MINS.
FRIDAY/FRIDAY NIGHT...SHOULD SEE PLENTY OF SUN WITH AREA COMING
UNDER THE CONTROL OF RIDGING/SUBSIDENCE/DRYING. SURFACE HIGH MOVES
ACROSS DURING THE DAY AND IS NOT TOO FAR EAST OF THE AREA BY LATE IN
THE AFTERNOON. NEW GUIDANCE IS CLOSE TO EACH OTHER AND NOT TOO
DIFFERENT FROM ONGOING FORECAST SO MADE LITTLE IF ANY CHANGES. WIND
FIELD STARTS OUT LIGHT BEFORE WAA AND DOWNSLOPE STARTS. TEMPERATURES
COULD FALL RAPIDLY BEFORE THIS GETS GOING.
SATURDAY/SATURDAY NIGHT...AGAIN LOOKS LIKE A LOT OF SUN THROUGH THE
DAY. WINDS STAY LIGHT THROUGH THE DAY BUT MOSTLY FROM A DOWNSLOPE
DIRECTION. NEWER GUIDANCE IS PRETTY CLOSE TO EACH OTHER AND WARMER
THAN CURRENT FORECAST. CONSIDERING THE DEEP/INCREASING WESTERLY FLOW
ALOFT THIS DOES MAKE SENSE. DRY AIR MASS AND DRY GROUND SHOULD ALLOW
A QUICK RESPONSE TO THE EVEN LIGHT DOWNSLOPE WIND. HOWEVER MAY HAVE
SOME WAVE CLOUDS DEVELOP EVEN THOUGH MODELS SAY NO. WILL WARM UP
MAXES SOME AT THIS TIME.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 1142 PM MST WED NOV 21 2012
SHORTWAVE TROUGH WILL MOVE FROM THE NORTHERN ROCKIES TO THE
CENTRAL PLAINS SUNDAY NIGHT AND MONDAY. MODEL SOLUTIONS CONTINUE TO
RETREAT FROM PRECIPITATION CHANCES...AND ITS LOOKING LIKE LITTLE
TO NONE IN THE LOCAL AREA. COLDER AIR WILL MOVE IN BEHIND THE COLD
FRONT SUNDAY NIGHT BUT COOL DOWN WILL BE SHORT LIVED. UPPER RIDGE
WILL QUICKLY REBUILD OVER THE GREAT BASIN EARLY IN THE WEEK THEN
ROCKIES BY MID WEEK. TEMPERATURES WILL RETURN TO ABOVE NORMAL BY
TUESDAY WITH NO PRECIPITATION CHANCES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 415 AM MST THU NOV 22 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. COLD FRONT WILL
MOVE THROUGH THE AREA THIS MORNING. AS IT DOES SO...WINDS WILL
INCREASE THROUGH THE MORNING AND BECOME GUSTY. SOME BLOWING DUST
COULD OCCUR BUT DO NOT EXPECT TO BE WIDESPREAD ENOUGH OR TO CREATE
SUB VFR CONDITIONS AT THIS TIME. WINDS ARE NOT EXPECTED TO
DECREASE UNTIL LATE IN THE AFTERNOON AND THEN REMAIN LIGHT THROUGH
THE REST OF THE NIGHT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...024
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
950 AM MST THU NOV 22 2012
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 226 AM MST THU NOV 22 2012
MAIN FORECAST ISSUE WILL BE THE WINDS TODAY WITH MINOR CONCERNS OF
HOW MUCH IT COOLS OFF THROUGH TOMORROW AND HOW MUCH THE WARM UP IS
ON SATURDAY. SATELLITE SHOWING AN AMPLIFIED PATTERN OVER THE PACIFIC
WITH A LESS AMPLIFIED MORE PROGRESSIVE FLOW FROM NORTH AMERICA INTO
THE ATLANTIC. COLD FRONT IS APPROACHING THE AREA FROM THE NORTHWEST.
AT JET LEVEL...THE ECMWF WAS DOING A LITTLE BETTER THAN THE UKMET...
CANADIAN...AND NAM ON THE JET SEGMENT ASSOCIATED WITH THE NORTHERN
STREAM SYSTEM. THE GFS FOLLOWED BY THE SREF WAS TOO STRONG WITH THE
JET BEHIND THE INCOMING TROUGH. AT MID LEVELS THE MODELS INITIALIZED
FINE WITH NO BIG PROBLEMS. THE RUC AND NAM WERE DOING BEST ON THE
WIND/PRESSURE FIELD. LOW LEVEL THERMAL GUIDANCE WAS CLOSE TO EACH
OTHER AND REALITY.
TODAY/TONIGHT...SATELLITE AND UPPER AIR IS SHOWING A VERY DRY AND
SUBSIDENT AIR MASS BEHIND THE SYSTEM MOVING ALONG THE CANADIAN AND
UNITED STATES BORDER.
SURFACE TO 850 MB WINDS ARE HIGHEST AT 12Z AND THEN DECREASE BY 18Z.
SOME PLACES COULD REACH 35 KNOT GUSTS. HIGHEST OBSERVED 3 HOUR
PRESSURE RISES HAVE OCCURRED MUCH FURTHER NORTH AND ARE NOT ANYTHING
OUT OF THE ORDINARY AT THIS TIME. FORECAST PRESSURE GRADIENT AND 3
HOUR PRESSURE RISES ARE HIGHEST EARLY ON AND DECREASE BY 18Z. IN FACT
BOTH WOULD INDICATE A QUICK BURST OF THE STRONGEST WINDS RIGHT AFTER
THE FROPA AND SUPPORT WINDY CONDITIONS BUT NOT QUITE AT ADVISORY
CRITERIA. STRONGEST SUBSIDENCE LOOKS TO BE NEAR THE NORTHERN PORTION
OF OUR AREA. THAT AND OTHER GUIDANCE WOULD SUPPORT THE HIGHEST WINDS
TO BE IN THE NORTHERN PORTION OF THE AREA AND MAYBE SOME OF THE
SOUTHWEST. SO HAVE CONTINUE TO HAVE WINDS JUST UNDER ADVISORY
CRITERIA WITH THE NORTH THE CLOSEST.
HIGH LEVEL CLOUDS WILL BE THICKEST EARLY DUE TO THE RIGHT REAR
QUADRANT OF THE MID AND UPPER JET BEING CLOSE. OVERNIGHT
TEMPERATURES HAVE BEEN ALL OVER THE PLACE AS THE PREFRONTAL TROUGH
WORKS ITS WAY ACROSS. FRONT LOOKS TO PUSH THROUGH THE AREA EARLY
TODAY. NWP IS WARMER THAN IT WAS YESTERDAY AND IN CLOSE AGREEMENT.
MADE ONLY SLIGHT ADJUSTMENTS.
GUIDANCE THIS MORNING KEEPS THE WINDS STRONGER FOR TONIGHT THAN THE
IT DID YESTERDAY DUE TO THE SURFACE RIDGE MOVING IN A LITTLE
SLOWER. SO WARMED UP THE MINS.
FRIDAY/FRIDAY NIGHT...SHOULD SEE PLENTY OF SUN WITH AREA COMING
UNDER THE CONTROL OF RIDGING/SUBSIDENCE/DRYING. SURFACE HIGH MOVES
ACROSS DURING THE DAY AND IS NOT TOO FAR EAST OF THE AREA BY LATE IN
THE AFTERNOON. NEW GUIDANCE IS CLOSE TO EACH OTHER AND NOT TOO
DIFFERENT FROM ONGOING FORECAST SO MADE LITTLE IF ANY CHANGES. WIND
FIELD STARTS OUT LIGHT BEFORE WAA AND DOWNSLOPE STARTS. TEMPERATURES
COULD FALL RAPIDLY BEFORE THIS GETS GOING.
SATURDAY/SATURDAY NIGHT...AGAIN LOOKS LIKE A LOT OF SUN THROUGH THE
DAY. WINDS STAY LIGHT THROUGH THE DAY BUT MOSTLY FROM A DOWNSLOPE
DIRECTION. NEWER GUIDANCE IS PRETTY CLOSE TO EACH OTHER AND WARMER
THAN CURRENT FORECAST. CONSIDERING THE DEEP/INCREASING WESTERLY FLOW
ALOFT THIS DOES MAKE SENSE. DRY AIR MASS AND DRY GROUND SHOULD ALLOW
A QUICK RESPONSE TO THE EVEN LIGHT DOWNSLOPE WIND. HOWEVER MAY HAVE
SOME WAVE CLOUDS DEVELOP EVEN THOUGH MODELS SAY NO. WILL WARM UP
MAXES SOME AT THIS TIME.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 1142 PM MST WED NOV 21 2012
SHORTWAVE TROUGH WILL MOVE FROM THE NORTHERN ROCKIES TO THE
CENTRAL PLAINS SUNDAY NIGHT AND MONDAY. MODEL SOLUTIONS CONTINUE TO
RETREAT FROM PRECIPITATION CHANCES...AND ITS LOOKING LIKE LITTLE
TO NONE IN THE LOCAL AREA. COLDER AIR WILL MOVE IN BEHIND THE COLD
FRONT SUNDAY NIGHT BUT COOL DOWN WILL BE SHORT LIVED. UPPER RIDGE
WILL QUICKLY REBUILD OVER THE GREAT BASIN EARLY IN THE WEEK THEN
ROCKIES BY MID WEEK. TEMPERATURES WILL RETURN TO ABOVE NORMAL BY
TUESDAY WITH NO PRECIPITATION CHANCES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 948 AM MST THU NOV 22 2012
VFR CONDITIONS WILL CONTINUE FOR THE NEXT 24 HOURS AT KGLD AND
KMCK. GUSTY NORTH WIND WILL GRADUALLY DECREASE BY SUNSET AND
OVERNIGHT INTO FRIDAY MORNING AS HIGH PRESSURE BUILDS INTO THE
REGION BEHIND THE COLD FRONT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...024
AVIATION...032
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1243 PM EST THU NOV 22 2012
.SYNOPSIS...
ISSUED AT 341 AM EST THU NOV 22 2012
A WINDY AND WARM THANKSGIVING DAY IS ON TAP FOR LOWER MICHIGAN.
TEMPERATURES WILL WARM INTO THE LOWER 60S AS GUSTY SOUTHERLY WINDS
BRING THE WARM AIR UP INTO MICHIGAN. THE WARMER AIR WILL BE SHORT
LIVED HOWEVER AS A STRONG COLD FRONT WILL MOVE THROUGH THE AREA LATE
TONIGHT. RAIN SHOWERS AND EVEN A SLIGHT CHANCE OF A RUMBLE OF
THUNDER WILL BE POSSIBLE.
THE COLDER AIR WILL FILTER INTO THE AREA DURING THE DAY ON FRIDAY.
TEMPERATURES WILL FALL THROUGH THE DAY INTO THE 30S. RAIN SHOWERS
WILL CHANGE OVER TO SNOW SHOWERS. SOME LIGHT ACCUMULATIONS WILL BE
POSSIBLE FOR THE LAKESHORE COMMUNITIES.
&&
.UPDATE...
ISSUED AT 1122 AM EST THU NOV 22 2012
I DID SOME SIGNIFICANT GRID UPDATES LATE THIS MORNING. I UPDATED
THE START OF THE GALE WARNING AND I INCREASED THE POP FOR BOTH
TONIGHT AND FRIDAY.
BASED ON THE LATEST DATA FROM BOTH THE NAM12 AND HRRR IT SEEMS TO ME
THE WINDS WILL RAMP UP SOONER OVER LAKE MICHIGAN AND OUR NEAR
SHORE WATERS. THE NAM12 SOUNDING AT MKG...BIV...LDM AND THE SOUTH
BUOY SHOW 40 TO 45 KNOTS IN THE MIX LAYER BY 21Z. CLOUDS MAY BE AN
ISSUE BUT AT 21Z I COULD SEE THERE NOT BEING A LOT OF CLOUDS YET.
AS A RESULT I BROUGHT FORWARD IN TIME THE START OF THE GALE
WARNING TO 4 PM FROM 10 PM.
THE NAM12 IS NOW SHOWING DEEPER MOISTURE FOR BOTH THE
PRECIPITATION EVENT TONIGHT AND THE LAKE ENHANCED SNOW FOR FRIDAY
AFTERNOON INTO SATURDAY MORNING. FOR THE MOST PART MY POP GRID IS
REALLY BASED ON THE LIFT IN THE SATURATED DGZ GRID FROM THE NAM12.
THAT HAS TIME AND AGAIN SHOWN ME TO BE THE MOST RELIABLE TOOL FOR
FORECASTING PRECIPITATION (RAIN/SNOW AND EVEN TIMING OF
THUNDERSTORMS IF THAT IS APPROPRIATE). THE SOUTHERN STREAM
MOISTURE (SEEN WELL ON THE WATER VAPOR LOOPS) IS STREAMING
NORTHEAST AND WILL RUN INTO THE FRONTAL ZONE LIFT BY MID
AFTERNOON. THIS SHOULD HAVE NO PROBLEM SPARKING SHOWERS AND
ISOLATED THUNDERSTORMS AS THERE IS A 50 - 70 KNOT LOW LEVEL JET
WITH PRECIPITABLE WATER VALUES OVER 300 PCT OF NORMAL JUST AHEAD
OF THE FRONT. I SEE NO REASON WHY I SHOULD NOT GO CONDITIONAL
GIVEN THE DEEP MOISTURE...STRONG LIFT AND STRONG FRONT WITH A GOOD
SOUTHERN STREAM SHORTWAVE.
AS FOR FRIDAY... THERE IS NOW BETTER LIFT IN THE DGZ ON THE NAM12
FOR THE LAKE EFFECT SNOW EVENT FRIDAY INTO FRIDAY NIGHT. I HAVE TO
LOOK AT THIS MORE CLOSELY BY WE MAY HAVE TO INCREASE SNOWFALL
AMOUNTS.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 341 AM EST THU NOV 22 2012
MAIN CHALLENGES IN THE SHORT TERM PORTION OF THE FCST REVOLVE AROUND
RAIN CHANCES TONIGHT...AND LAKE EFFECT TRENDS FRI THROUGH SAT. THE
ONLY REAL CHANGE TO THE FCST WAS TO SLIP A SLIGHT CHC MENTION OF
THUNDER IN THE FCST FOR LATE THIS AFTERNOON AND EVENING.
MANY OBSERVATIONS THIS MORNING ARE TRYING TO DROP THE VISIBILITIES
IN FOG. SITES ARE DOWN TO BETWEEN 1-4SM. THEY HAVE STABILIZED AS IT
APPEARS THE WINDS ALOFT...AND RESIDUAL BREEZE AT THE SURFACE ARE
KEEPING CONDITIONS FROM DROPPING TOO MUCH. WE DO NOT EXPECT TO HAVE
TO ISSUE ANY FOG HEADLINES THIS MORNING.
THE FIRST 2/3RDS OF THE DAY TODAY LOOKS QUITE NICE. WE SHOULD SEE A
GOOD DEAL OF SUNSHINE INTO THE FIRST PORTION OF THE AFTERNOON WITH
ONLY SOME HIGH CLOUDS MOVING THROUGH. IT WILL BE BREEZY WITH WIND
GUSTS APPROACHING 30 MPH IF NOT ECLIPSING IT AT TIMES. WE WILL SEE
THE MOISTURE TRANSPORT PICK UP SIGNIFICANTLY BETWEEN 18Z AND 00Z
TONIGHT AS THE LOW LEVEL JET AXIS MOVES OVERHEAD. WE SHOULD SEE THE
MOSTLY SUNNY SKIES TURN MOSTLY CLOUDY PRETTY QUICK LATER THIS
AFTERNOON. DEEP ENOUGH MOISTURE IS FOUND ACROSS THE WRN COUNTIES
WHERE ANY RAIN THAT FORMS COULD REACH THE GROUND BY 00Z.
THE BEST THREAT OF RAIN WILL COME BETWEEN 00Z AND 09Z TONIGHT...AND
ACROSS THE SE 2/3RDS OF THE CWFA. THIS IS WHERE THE DEEPEST MOISTURE
COMES TOGETHER DUE TO THE WAY THE UPPER MOISTURE ADVECTS INTO THE
AREA AHEAD OF THE WAVE. AS MENTIONED ABOVE...WE HAVE ADDED THUNDER
TO THE FCST. MODELS ARE INDICATING A LITTLE MORE ELEVATED
INSTABILITY PRESENT THAN 24 HOURS AGO. SEVERE THREAT SHOULD REMAIN
RATHER LOW DUE TO THE GENERAL NATURE OF THE ELEVATED INSTABILITY.
THE STRONG LOW LEVEL JET IS SOME CAUSE FOR CONCERN AS IT WOULDN/T
TAKE MUCH TO MIX IT DOWN. HOWEVER...ONCE AGAIN THE ELEVATED NATURE
OF THE INSTABILITY SHOULD LIMIT THE SEVERE POTENTIAL.
WE WILL SEE THE DRY SLOT TRAVERSE THE AREA BETWEEN 09Z AND 15Z FRI.
AFTER 15Z...WE SEE THE WRAP AROUND MOISTURE ROTATE BACK IN ACROSS
THE AREA. H850 TEMPS DROP PRETTY QUICK AT THIS TIME TO EVENTUALLY
AROUND -10C. WE EXPECT THAT THE WRAP AROUND MOISTURE WILL START OUT
AS SOME RAIN AND/OR SNOW SHOWERS THAT WILL TRANSITION TO ALL SNOW
SHOWERS PRETTY QUICKLY.
A FEW SCATTERED SYNOPTIC SNOW SHOWERS WILL REMAIN POSSIBLE. THE
FOCUS WILL TURN ON LAKE EFFECT BY LATE FRI AFTERNOON. DELTA T/S WILL
BE APPROACHING 20C. WE WILL HAVE CYCLONIC FLOW ALOFT. MOISTURE WILL
BE SOMEWHAT LIMITED...WITH INVERSION HEIGHTS AROUND 7-8K FT. THE
BEST LIFT IS BELOW THE DGZ SO WE DO NOT EXPECT SIGNIFICANT SNOW
RATES. THE FLOW WILL TRANSITION FROM WNW TO PURE NW BY 00Z SAT. THIS
WILL LAST INTO THE FIRST HALF OF SAT. WE ARE EXPECTING THAT A COUPLE
OF LOCATIONS MAY SEE AN INCH OR TWO FROM LATE FRI INTO MIDDAY SAT.
THE UPPER LOW WILL LIFT OUT OF THE AREA SAT AFTERNOON. THE UPPER
FLOW BECOMES ANTI-CYCLONIC BY 18Z...LIMITING THE MOISTURE DEPTH
QUITE A BIT. WE SHOULD SEE SNOW SHOWERS DIMINISH BY SAT
AFTERNOON...AND ANYTHING LEFT SPREADING INLAND ONCE AGAIN WITH THE
WRLY WIND SETTING UP WITH THE SFC HIGH MOVING THOUGH.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 341 AM EST THU NOV 22 2012
MODEL DISCREPANCIES CONTINUE IN THE LONG TERM PERIOD...ESPECIALLY IN
REGARD TO WHAT WOULD BE THE MOST SIGNIFICANT PRECIPITATION POTENTIAL
DURING THE PERIOD...THE SYSTEM FOR NEXT TUESDAY.
FIRST THOUGH A WEAK SYSTEM WILL PROGRESS EAST ACROSS THE NORTHERN
GREAT LAKES SATURDAY NIGHT INTO SUNDAY. COULD BE A LITTLE LIGHT SNOW
ACROSS CENTRAL LOWER...BUT NOT EXPECTING MUCH.
FOCUS THEN SHIFTS TO A POTENTIAL SYSTEM FOR TUESDAY INTO TUESDAY
NIGHT. THE GFS HAS A STRONGER MORE NORTHERN TRACK...WHILE THE ECMWF
WOULD BE WELL SOUTH AND WEAKER. AT THIS POINT CONFIDENCE IS NOT HIGH
IN WHICH SOLUTION IS MOST LIKELY TO VERIFY. GIVEN THE TYPICALLY
BETTER TRACK RECORD OF THE ECMWF IN THE 4-7 DAY PERIOD WOULD LEAN
TOWARD THE DRIER SOLUTION. THE GFS WOULD YIELD ACCUMULATING SNOW
ACROSS THE FORECAST AREA. CHANCE POPS IN THE FORECAST AT THIS POINT.
INTO WEDNESDAY THE ECMWF BRINGS A SHORTWAVE THROUGH ACCOMPANIED BY
SOME LIGHT SNOW AND LAKE ENHANCEMENT. MODEL DISCREPANCIES CONTINUE
INTO THIS TIME FRAME WITH THE GFS INDICATING DRY WX.
SUFFICE IT TO SAY AN OVERALL LOW CONFIDENCE FORECAST IN THE LONG
TERM. TEMPERATURES LOOK TO BE BELOW NORMAL THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1243 PM EST THU NOV 22 2012
MAIN AVIATION CONCERN THROUGH THIS AFTERNOON WILL BE THE
SOUTHERLY WINDS WHICH WILL GUST 20 TO 25 KTS. THESE ARE EXPECTED
TO TAPER OFF SOMEWHAT BY NIGHTFALL.
A STRONG COLD WILL BRING IN LOWER CEILINGS ALONG WITH RAIN SHOWERS
AND EVEN MORE WIND LATE TONIGHT. DUE TO THE AMOUNT OF MIXING
EXPECTED...MOST LOCATIONS WILL ONLY DIP DOWN TO MVFR WITH VERY
PATCHY IFR NEAR AND JUST BEHIND THE FRONT. CAN NOT COMPLETELY RULE
OUT A THUNDERSTORM WITH THE FRONT...BUT HAVE LEFT THAT OUT OF THE
TAFS AS ANY THUNDER SHOULD REMAIN VERY ISOLATED.
A DRY SLOT IS EXPECTED TO ROLL IN AROUND DAYBREAK. SO WE WILL
LIKELY SEE A PERIOD OF HIGHER CEILINGS AND VSBYS WITH THIS.
HOWEVER AS COLDER AIR EVADES THE REGION THROUGH THE MID FRI MORNING
HOURS LAKE EFFECT CLOUDS AND SNOW SHOWERS CAN BE EXPECTED. WITH
WNW FLOW EXPECT SOME AREAS OF IFR TO DEVELOP IN LOWERING VSBYS
AFTER ABOUT 14-16Z FRI.
&&
.MARINE...
ISSUED AT 1122 AM EST THU NOV 22 2012
I BROUGHT FORWARD IN TIME THE START OF THE GALE WARING FROM 10 PM
TO 4 PM. THIS IDEA IS BASED ON THE LATEST DATA FROM BOTH THE
NAM12 AND HRRR IT SEEMS TO ME THE WINDS WILL RAMP UP SOONER OVER
LAKE MICHIGAN AND OUR NEAR SHORE WATERS. THE NAM12 SOUNDING AT
MKG...BIV...LDM AND THE SOUTH BUOY SHOW 40 TO 45 KNOTS IN THE MIX
LAYER BY 21Z. CLOUDS MAY BE AN ISSUE BUT AT 21Z I COULD SEE THERE
NOT BEING A LOT OF CLOUDS YET. AS A RESULT I BROUGHT FORWARD IN
TIME THE START OF THE GALE WARNING TO 4 PM FROM 10 PM.
&&
.HYDROLOGY...
ISSUED AT 341 AM EST THU NOV 22 2012
WE CONTINUE TO EXPECT NO HYDROLOGY ISSUES THROUGH THIS FCST PERIOD.
WE ARE EXPECTING A QUICK SHOT OF RAINFALL WITH THE FRONT VERY LATE
TODAY AND MORE SO TONIGHT. RAINFALL AMOUNTS SHOULD RANGE FROM A
TENTH OR TWO UP NORTH...UP TO AS MUCH AS HALF AN INCH. RIVER AND
STREAM LEVELS CONTINUE TO FLOW BELOW AVERAGE. SOME LAKE EFFECT SNOW
SHOWERS WILL BE AROUND FRIDAY...BUT THIS SHOULD NOT HAVE A LOT OF
WATER CONTENT IN IT. MINIMAL RISES CAN BE EXPECTED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
LMZ844>849.
GALE WARNING FROM 4 PM THIS AFTERNOON TO 10 PM EST FRIDAY FOR
LMZ844>849.
&&
$$
UPDATE...WDM
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...DUKE
AVIATION...JK
HYDROLOGY...NJJ
MARINE...WDM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1122 AM EST THU NOV 22 2012
.SYNOPSIS...
ISSUED AT 341 AM EST THU NOV 22 2012
A WINDY AND WARM THANKSGIVING DAY IS ON TAP FOR LOWER MICHIGAN.
TEMPERATURES WILL WARM INTO THE LOWER 60S AS GUSTY SOUTHERLY WINDS
BRING THE WARM AIR UP INTO MICHIGAN. THE WARMER AIR WILL BE SHORT
LIVED HOWEVER AS A STRONG COLD FRONT WILL MOVE THROUGH THE AREA LATE
TONIGHT. RAIN SHOWERS AND EVEN A SLIGHT CHANCE OF A RUMBLE OF
THUNDER WILL BE POSSIBLE.
THE COLDER AIR WILL FILTER INTO THE AREA DURING THE DAY ON FRIDAY.
TEMPERATURES WILL FALL THROUGH THE DAY INTO THE 30S. RAIN SHOWERS
WILL CHANGE OVER TO SNOW SHOWERS. SOME LIGHT ACCUMULATIONS WILL BE
POSSIBLE FOR THE LAKESHORE COMMUNITIES.
&&
.UPDATE...
ISSUED AT 1122 AM EST THU NOV 22 2012
I DID SOME SIGNIFICANT GRID UPDATES LATE THIS MORNING. I UPDATED
THE START OF THE GALE WARNING AND I INCREASED THE POP FOR BOTH
TONIGHT AND FRIDAY.
BASED ON THE LATEST DATA FROM BOTH THE NAM12 AND HRRR IT SEEMS TO ME
THE WINDS WILL RAMP UP SOONER OVER LAKE MICHIGAN AND OUR NEAR
SHORE WATERS. THE NAM12 SOUNDING AT MKG...BIV...LDM AND THE SOUTH
BUOY SHOW 40 TO 45 KNOTS IN THE MIX LAYER BY 21Z. CLOUDS MAY BE AN
ISSUE BUT AT 21Z I COULD SEE THERE NOT BEING A LOT OF CLOUDS YET.
AS A RESULT I BROUGHT FORWARD IN TIME THE START OF THE GALE
WARNING TO 4 PM FROM 10 PM.
THE NAM12 IS NOW SHOWING DEEPER MOISTURE FOR BOTH THE
PRECIPITATION EVENT TONIGHT AND THE LAKE ENHANCED SNOW FOR FRIDAY
AFTERNOON INTO SATURDAY MORNING. FOR THE MOST PART MY POP GRID IS
REALLY BASED ON THE LIFT IN THE SATURATED DGZ GRID FROM THE NAM12.
THAT HAS TIME AND AGAIN SHOWN ME TO BE THE MOST RELIABLE TOOL FOR
FORECASTING PRECIPITATION (RAIN/SNOW AND EVEN TIMING OF
THUNDERSTORMS IF THAT IS APPROPRIATE). THE SOUTHERN STREAM
MOISTURE (SEEN WELL ON THE WATER VAPOR LOOPS) IS STREAMING
NORTHEAST AND WILL RUN INTO THE FRONTAL ZONE LIFT BY MID
AFTERNOON. THIS SHOULD HAVE NO PROBLEM SPARKING SHOWERS AND
ISOLATED THUNDERSTORMS AS THERE IS A 50 - 70 KNOT LOW LEVEL JET
WITH PRECIPITABLE WATER VALUES OVER 300 PCT OF NORMAL JUST AHEAD
OF THE FRONT. I SEE NO REASON WHY I SHOULD NOT GO CONDITIONAL
GIVEN THE DEEP MOISTURE...STRONG LIFT AND STRONG FRONT WITH A GOOD
SOUTHERN STREAM SHORTWAVE.
AS FOR FRIDAY... THERE IS NOW BETTER LIFT IN THE DGZ ON THE NAM12
FOR THE LAKE EFFECT SNOW EVENT FRIDAY INTO FRIDAY NIGHT. I HAVE TO
LOOK AT THIS MORE CLOSELY BY WE MAY HAVE TO INCREASE SNOWFALL
AMOUNTS.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 341 AM EST THU NOV 22 2012
MAIN CHALLENGES IN THE SHORT TERM PORTION OF THE FCST REVOLVE AROUND
RAIN CHANCES TONIGHT...AND LAKE EFFECT TRENDS FRI THROUGH SAT. THE
ONLY REAL CHANGE TO THE FCST WAS TO SLIP A SLIGHT CHC MENTION OF
THUNDER IN THE FCST FOR LATE THIS AFTERNOON AND EVENING.
MANY OBSERVATIONS THIS MORNING ARE TRYING TO DROP THE VISIBILITIES
IN FOG. SITES ARE DOWN TO BETWEEN 1-4SM. THEY HAVE STABILIZED AS IT
APPEARS THE WINDS ALOFT...AND RESIDUAL BREEZE AT THE SURFACE ARE
KEEPING CONDITIONS FROM DROPPING TOO MUCH. WE DO NOT EXPECT TO HAVE
TO ISSUE ANY FOG HEADLINES THIS MORNING.
THE FIRST 2/3RDS OF THE DAY TODAY LOOKS QUITE NICE. WE SHOULD SEE A
GOOD DEAL OF SUNSHINE INTO THE FIRST PORTION OF THE AFTERNOON WITH
ONLY SOME HIGH CLOUDS MOVING THROUGH. IT WILL BE BREEZY WITH WIND
GUSTS APPROACHING 30 MPH IF NOT ECLIPSING IT AT TIMES. WE WILL SEE
THE MOISTURE TRANSPORT PICK UP SIGNIFICANTLY BETWEEN 18Z AND 00Z
TONIGHT AS THE LOW LEVEL JET AXIS MOVES OVERHEAD. WE SHOULD SEE THE
MOSTLY SUNNY SKIES TURN MOSTLY CLOUDY PRETTY QUICK LATER THIS
AFTERNOON. DEEP ENOUGH MOISTURE IS FOUND ACROSS THE WRN COUNTIES
WHERE ANY RAIN THAT FORMS COULD REACH THE GROUND BY 00Z.
THE BEST THREAT OF RAIN WILL COME BETWEEN 00Z AND 09Z TONIGHT...AND
ACROSS THE SE 2/3RDS OF THE CWFA. THIS IS WHERE THE DEEPEST MOISTURE
COMES TOGETHER DUE TO THE WAY THE UPPER MOISTURE ADVECTS INTO THE
AREA AHEAD OF THE WAVE. AS MENTIONED ABOVE...WE HAVE ADDED THUNDER
TO THE FCST. MODELS ARE INDICATING A LITTLE MORE ELEVATED
INSTABILITY PRESENT THAN 24 HOURS AGO. SEVERE THREAT SHOULD REMAIN
RATHER LOW DUE TO THE GENERAL NATURE OF THE ELEVATED INSTABILITY.
THE STRONG LOW LEVEL JET IS SOME CAUSE FOR CONCERN AS IT WOULDN/T
TAKE MUCH TO MIX IT DOWN. HOWEVER...ONCE AGAIN THE ELEVATED NATURE
OF THE INSTABILITY SHOULD LIMIT THE SEVERE POTENTIAL.
WE WILL SEE THE DRY SLOT TRAVERSE THE AREA BETWEEN 09Z AND 15Z FRI.
AFTER 15Z...WE SEE THE WRAP AROUND MOISTURE ROTATE BACK IN ACROSS
THE AREA. H850 TEMPS DROP PRETTY QUICK AT THIS TIME TO EVENTUALLY
AROUND -10C. WE EXPECT THAT THE WRAP AROUND MOISTURE WILL START OUT
AS SOME RAIN AND/OR SNOW SHOWERS THAT WILL TRANSITION TO ALL SNOW
SHOWERS PRETTY QUICKLY.
A FEW SCATTERED SYNOPTIC SNOW SHOWERS WILL REMAIN POSSIBLE. THE
FOCUS WILL TURN ON LAKE EFFECT BY LATE FRI AFTERNOON. DELTA T/S WILL
BE APPROACHING 20C. WE WILL HAVE CYCLONIC FLOW ALOFT. MOISTURE WILL
BE SOMEWHAT LIMITED...WITH INVERSION HEIGHTS AROUND 7-8K FT. THE
BEST LIFT IS BELOW THE DGZ SO WE DO NOT EXPECT SIGNIFICANT SNOW
RATES. THE FLOW WILL TRANSITION FROM WNW TO PURE NW BY 00Z SAT. THIS
WILL LAST INTO THE FIRST HALF OF SAT. WE ARE EXPECTING THAT A COUPLE
OF LOCATIONS MAY SEE AN INCH OR TWO FROM LATE FRI INTO MIDDAY SAT.
THE UPPER LOW WILL LIFT OUT OF THE AREA SAT AFTERNOON. THE UPPER
FLOW BECOMES ANTI-CYCLONIC BY 18Z...LIMITING THE MOISTURE DEPTH
QUITE A BIT. WE SHOULD SEE SNOW SHOWERS DIMINISH BY SAT
AFTERNOON...AND ANYTHING LEFT SPREADING INLAND ONCE AGAIN WITH THE
WRLY WIND SETTING UP WITH THE SFC HIGH MOVING THOUGH.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 341 AM EST THU NOV 22 2012
MODEL DISCREPANCIES CONTINUE IN THE LONG TERM PERIOD...ESPECIALLY IN
REGARD TO WHAT WOULD BE THE MOST SIGNIFICANT PRECIPITATION POTENTIAL
DURING THE PERIOD...THE SYSTEM FOR NEXT TUESDAY.
FIRST THOUGH A WEAK SYSTEM WILL PROGRESS EAST ACROSS THE NORTHERN
GREAT LAKES SATURDAY NIGHT INTO SUNDAY. COULD BE A LITTLE LIGHT SNOW
ACROSS CENTRAL LOWER...BUT NOT EXPECTING MUCH.
FOCUS THEN SHIFTS TO A POTENTIAL SYSTEM FOR TUESDAY INTO TUESDAY
NIGHT. THE GFS HAS A STRONGER MORE NORTHERN TRACK...WHILE THE ECMWF
WOULD BE WELL SOUTH AND WEAKER. AT THIS POINT CONFIDENCE IS NOT HIGH
IN WHICH SOLUTION IS MOST LIKELY TO VERIFY. GIVEN THE TYPICALLY
BETTER TRACK RECORD OF THE ECMWF IN THE 4-7 DAY PERIOD WOULD LEAN
TOWARD THE DRIER SOLUTION. THE GFS WOULD YIELD ACCUMULATING SNOW
ACROSS THE FORECAST AREA. CHANCE POPS IN THE FORECAST AT THIS POINT.
INTO WEDNESDAY THE ECMWF BRINGS A SHORTWAVE THROUGH ACCOMPANIED BY
SOME LIGHT SNOW AND LAKE ENHANCEMENT. MODEL DISCREPANCIES CONTINUE
INTO THIS TIME FRAME WITH THE GFS INDICATING DRY WX.
SUFFICE IT TO SAY AN OVERALL LOW CONFIDENCE FORECAST IN THE LONG
TERM. TEMPERATURES LOOK TO BE BELOW NORMAL THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 649 AM EST THU NOV 22 2012
FOG GENERALLY BETWEEN 1-4SM ACROSS THE AREA WILL LIFT FAIRLY QUICK
AFTER SUNRISE. EXPECT ALL SITES TO BE VFR BY 15Z OR SO. SKIES WILL
BE MAINLY CLEAR THROUGH MID AFTERNOON. THE WIND WILL BE THE MAIN
WEATHER ISSUE TODAY WITH SOUTH-SOUTHWEST WINDS OF 13-25 KNOTS
THROUGH THE COURSE OF THE DAY.
RAIN SHOWERS WILL BREAK OUT ACROSS THE AREA BETWEEN 21Z AND
00Z...SPREADING EAST WITH TIME. A RUMBLE OF THUNDER CANNOT BE
RULED OUT BETWEEN 22Z AND 05Z...BUT THE THREAT IS TOO LOW TO
INCLUDE IN THE TAFS AT THIS TIME. CEILINGS WILL BE VFR THIS
EVENING BEFORE DROPPING TO MVFR AFTER 05Z.
&&
.MARINE...
ISSUED AT 1122 AM EST THU NOV 22 2012
I BROUGHT FORWARD IN TIME THE START OF THE GALE WARING FROM 10 PM
TO 4 PM. THIS IDEA IS BASED ON THE LATEST DATA FROM BOTH THE
NAM12 AND HRRR IT SEEMS TO ME THE WINDS WILL RAMP UP SOONER OVER
LAKE MICHIGAN AND OUR NEAR SHORE WATERS. THE NAM12 SOUNDING AT
MKG...BIV...LDM AND THE SOUTH BUOY SHOW 40 TO 45 KNOTS IN THE MIX
LAYER BY 21Z. CLOUDS MAY BE AN ISSUE BUT AT 21Z I COULD SEE THERE
NOT BEING A LOT OF CLOUDS YET. AS A RESULT I BROUGHT FORWARD IN
TIME THE START OF THE GALE WARNING TO 4 PM FROM 10 PM.
&&
.HYDROLOGY...
ISSUED AT 341 AM EST THU NOV 22 2012
WE CONTINUE TO EXPECT NO HYDROLOGY ISSUES THROUGH THIS FCST PERIOD.
WE ARE EXPECTING A QUICK SHOT OF RAINFALL WITH THE FRONT VERY LATE
TODAY AND MORE SO TONIGHT. RAINFALL AMOUNTS SHOULD RANGE FROM A
TENTH OR TWO UP NORTH...UP TO AS MUCH AS HALF AN INCH. RIVER AND
STREAM LEVELS CONTINUE TO FLOW BELOW AVERAGE. SOME LAKE EFFECT SNOW
SHOWERS WILL BE AROUND FRIDAY...BUT THIS SHOULD NOT HAVE A LOT OF
WATER CONTENT IN IT. MINIMAL RISES CAN BE EXPECTED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
LMZ844>849.
GALE WARNING FROM 4 PM THIS AFTERNOON TO 10 PM EST FRIDAY FOR
LMZ844>849.
&&
$$
UPDATE...WDM
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...NJJ
MARINE...WDM
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
222 PM CST THU NOV 22 2012
.DISCUSSION...
THERE IS ABOUT A 30 DEGREE DIFFERENCE IN THE TEMPERATURE EARLY
THIS AFTERNOON ACROSS THE CWA FROM WEST TO EAST. THE STRONG COLD
FRONT IS NEAR A RICE LAKE-MENOMINEE LINE AND WILL BE EAST OF OUR
CWA BY 22Z. IN THE WAKE OF THE FRONT...NORTHWEST WINDS OF 20 TO 25
MPH WITH GUSTS WELL INTO THE 30 MPH RANGE ARE COMMON. A BAND OF RAIN
AND SNOW EXISTS AS WELL BEHIND THE FRONT FROM SOUTHWEST MN THROUGH
CENTRAL AREAS OF THE STATE AND INTO THE ARROWHEAD. THIS IS AHEAD
OF AN AXIS OF MID LEVEL FRONTOGENESIS ALONG WITH A SUBSTANTIAL PV
BOOT AIMED AT KDLH. WEB CAMS THIS AFTERNOON HAVE INDICATED A QUICK
COATING OF SNOW AS THE BAND MOVES THROUGH.
OUR LOCAL WRF AND THE HRRR HAVE A PRETTY GOOD HANDLE ON THE
PRECIPITATION PATTERN. THE BAND OF FRONTOGENESIS WILL MOVE THROUGH
THE EASTERN MN...INCLUDING THE TWIN CITIES...IN THE 21Z-24Z TIME
FRAME AND ACROSS WEST CENTRAL WI IN THE 00Z-03Z PERIOD. OUR WRF
AND THE HRRR SUGGEST THE BEST CHANCES FOR PRECIPITATION DURING THE
LATE AFTERNOON AND EARLY EVENING HOURS ARE FROM THE NORTH METRO ON
NORTH AND EAST. THIS IS WHERE LIKELY POPS EXIST FOR A TIME WITH
DIMINISHING POPS TO THE SOUTH. A QUICK HALF INCH OF SNOW IS NOT
OUT OF THE QUESTION.
DURING THE LATE EVENING THROUGH OVERNIGHT HOURS...A SECONDARY
TROUGH WILL ROTATE SOUTHEAST ACROSS THE FA. SOME LIGHT SNOW IS
LIKELY...ESPECIALLY OVER OUR FAR NORTHERN TIER OF COUNTIES WITH
PERHAPS A HALF INCH OF SNOW. THEREFORE...RAISED POPS INTO THE LIKELY
CATEGORY FOR THIS AREA WITH CHANCE POPS FOR A FEW ROWS OF COUNTIES
TO THE SOUTH. ADDED FLURRIES ELSEWHERE OVERNIGHT AND FRIDAY
MORNING WITH THE COLD...MOIST...CYCLONIC FLOW.
DEBATED ON WHAT TO DO WITH THE WIND ADVISORY IN EFFECT THROUGH THE
NIGHT. I WOULD PREFER TO SEE AT LEAST A 10 MB PRESSURE GRADIENT
FROM KMSP TO THE SD BORDER. WE ARE CURRENTLY RUNNING AT 8 MB AND
MOST SOLUTIONS KEEP IT THIS WAY THROUGH THE NIGHT. HOWEVER...
EXAMINATION OF THE VERTICAL PROFILES FROM THE NAM THROUGH BUFKIT
INDICATE WEST CENTRAL THROUGH SOUTH CENTRAL MN AS HAVING PRETTY
GOOD POTENTIAL FOR SEEING 30 MPH SUSTAINED WINDS DURING THE
EVENING HOURS. IN ADDITION...TOP OF THE CHANNEL MOMENTUM TRANSFER
INDICATES THE POTENTIAL FOR EAST CENTRAL MN...INCLUDING THE TWIN
CITIES...TO HAVE GUSTS POTENTIAL NEAR 45 MPH DURING THE EVENING AS
WELL. LOOKING AT THE SREF...SEVERAL NMMB MEMBERS WERE BETWEEN 42
AND 45 KNOTS ADDING CONFIDENCE TO THE NAM SOLUTION. EVEN THE
FAVORITE ARW KF MEMBER WAS AT 42 KNOTS. HENCE...WILL NOT MESS WITH
THE ADVISORY AT THIS TIME WITH PLENTY OF POTENTIAL FOR
VERIFICATION OVER THE NEXT 8 TO 12 HOURS.
IT WILL BE BLUSTERY AND COLD OVER THE AREA TOMORROW AS BRISK
NORTHWEST WINDS CONTINUE. HIGHS WILL ONLY BE IN THE 20S. FACTOR IN
THE WIND AND THE APPARENT TEMPERATURE IS ONLY IN THE SINGLE DIGITS
AND TEENS. THERE SHOULD BE SOME FLURRIES AS WELL OVER EASTERN
AREAS IN THE MORNING.
NOTHING TOO EXCITING DURING THE WEEKEND OR NEXT WEEK. HIGH PRESSURE
WILL PASS BY ON SATURDAY WITH A LITTLE MODERATION IN TEMPERATURE
FOR SUNDAY BEFORE ANOTHER COLD FRONT PUSHES THROUGH ON MONDAY.
THERE ARE SOME DIFFERENCES BETWEEN THE GFS/GEM AND THE ECMWF
REGARDING A LOW PRESSURE SYSTEM PASSING SOUTH OF US MONDAY NIGHT
AND TUESDAY. THE GFS/GEM HAVE IT FARTHER NORTH WITH SNOW INTO FAR
SOUTHERN MN WHILE THE ECMWF HAS HIGH PRESSURE OVER IA WITH THE LOW
WAY SOUTHEAST. COLLABORATION WAS TO LEAVE THE SMALL POPS IN THE
FAR SOUTH PART OF MN DUE TO THE DIFFERENCES.
&&
.AVIATION... /18Z TAF ISSUANCE/
FRONT ALREADY IN THE WESTERN SUBURBS OF THE TWIN CITIES WITH WINDS
SHIFTING TO THE W/WNW AND BEGINNING TO GUST OVER 20 KTS. ABOUT 50
MILES TO THE WEST OF THE FRONTAL PASSAGE...WINDS INCREASE TO ARND
20 KTS...WITH GUSTS ALREADY EXCEEDING OR APPROACHING 30 TO 35 KTS.
IN ADDITION...MVFR/IFR CIGS HAD DEVELOPED BEHIND THIS FRONT ALONG
WITH SOME BR...BUT THESE CIGS HAVE SLOWED A BIT IN THE LAST
HR...AND WITH DIURNAL MIXING AHEAD OF IT...BELIEVE CIGS WILL
EVENTUALLY RISE TO 1.5 OR 2.5K DURING THE MID/LATE AFTN HRS. OUT
WEST IFR/LOW END MVFR CIGS WILL LIKELY CONTINUE BASED ON LITTLE
MIXING ON THE ONSET OF THESE LOWER CIGS. SOME -SHRA...MIXED WITH
IP/SN WAS DEVELOPING ACROSS FAR NE SD...WC MN WHICH IS PROGGED TO
MOVE E/NE ACROSS MAINLY THE NW FA DURING THE AFTN HRS. AS THE
ACTIVITY MOVED ACROSS SD...VSBYS DID NOT DECREASE AS RAPIDLY...SO
WILL CONTINUE WITH HIGH END MVFR VSBYS IN -SN/IP/RA THIS AFTN.
ONCE THE CHG OVER TO -SN OCCURS...THE VSBYS COULD
DROP...ESPECIALLY AT AXN/STC OVERNIGHT AS BETTER FORCING AND
DEEPER MOISTURE RESIDES. WINDS WILL BE THE STRONGEST DURING THE
EVENING/OVERNIGHT HRS...THEN SLOWLY DECREASING FRIDAY
MORNING...BUT REMAINING GUSTY.
KMSP...
MVFR CIGS IN THE WESTERN SUBURBS OF THE TWIN CITIES IS THE MAIN
CONCERN IN THE FIRST 3-6 HRS...DECIDED TO GO WITH MORE MIXING THIS
AFTN WITH CIGS BECOMING 2.0K BY 20Z. SOME CLDS BLW 1.5K WILL BE
NOTED...BUT IT SHOULD NOT BE A CIG THIS AFTN. WILL CONTINUE TO
MONITOR CIGS IN THE WEST AND SEE IF THESE CONTINUE TO THEIR STEADY
PACE TOWARD MSP. SOME -SHRA WILL BE POSSIBLE THIS AFTN...BUT MORE
LIKELY AFT 22Z...THRU 01Z. DEEPER MOISTURE ALONG WITH BETTER
FORCING DEVELOPS OVERNIGHT WHICH MAY MEAN SCATTERED -SN...WITH
MVFR VSBYS. BUT CONFIDENCE IS TOO LOW TO HAVE ANYTHING OTHER THAN
FLURRIES. CIGS WILL LIKELY HOLD IN THE MVFR RANGE OVERNIGHT...WITH
CIGS SLOWLY RISING AND BECOMING VFR FRIDAY AFTN.
/OUTLOOK FOR KMSP/
SAT...VFR. WINDS S AT 5-10KTS.
SUN...VFR. WINDS WNW AT 5-10KTS.
MON...MAINLY VFR...POSSIBLE MVFR CIGS LATE WITH -SN.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND ADVISORY UNTIL 6 AM CST FRIDAY FOR ANOKA-BLUE EARTH-BROWN-
CARVER-CHIPPEWA-DAKOTA-DOUGLAS-FARIBAULT-FREEBORN-GOODHUE-
HENNEPIN-KANDIYOHI-LAC QUI PARLE-LE SUEUR-MARTIN-MCLEOD-
MEEKER-NICOLLET-POPE-RAMSEY-REDWOOD-RENVILLE-RICE-SCOTT-
SHERBURNE-SIBLEY-STEARNS-STEELE-STEVENS-SWIFT-TODD-WASECA-
WASHINGTON-WATONWAN-WRIGHT-YELLOW MEDICINE.
WI...NONE.
&&
$$
RAH/JLT
AREA FORECAST DISCUSSION
NWS BILLINGS MT
922 AM MST THU NOV 22 2012
.SHORT TERM...VALID FOR TDY AND FRI...
CANADIAN COLD FRONT AND ASSOCIATED PRESSURE RISES SURGING MUCH
FURTHER WEST THAN PREVIOUSLY THOUGHT. COLD AIR HAS PUSHED THROUGH
JUDITH GAP WHERE TEMP MADE AN 11 DEGREE DROP FROM 31F TO 20F LAST
HOUR. STRONG COLD ADVECTION FURTHER EAST IS NOT QUITE TO MILES
CITY AND BAKER BUT WILL BE BEFORE MIDDAY. WITH TEMPS LARGELY IN
THE TEENS UPSTREAM...EXPECT A FAIRLY DRAMATIC TEMPERATURE DROP
ESPECIALLY IN OUR EAST. PER LOCATION OF UPSTREAM PRESSURE
RISES...THINK THIS FROPA WILL HAVE SOME IMPACT AT BILLINGS AS
WELL. FOR BILLINGS...EXPECT A SHIFT TO NORTH THEN EVENTUALLY
NORTHEAST WINDS THIS AFTERNOON...AND AN ASSOCIATED TEMPERATURE
DROP TO MAYBE THE LOW 30S/UPPER 20S AFTER A MIDDAY HIGH IN THE
LOW 40S. AS FOR PCPN...TROWAL WRAPPING SOUTHWARD THROUGH NORTHERN
MT WILL BRING SOME LIGHT SNOW SHOWERS TO OUR EASTERN PARTS...WITH
STRONGEST ASCENT PER THE RAP EXPECTED TO BE FROM ABOUT 18-23Z.
GIVEN MOISTENING OF DENDRITIC LAYER WHICH WILL FALL TO THE
SFC...COULD BE A DUSTING IN PLACES MAINLY EAST OF HYSHAM AND LAME
DEER. AREAS FROM FORSYTH TO BAKER HAVE ALSO EXPERIENCED SOME
STRATUS THIS MORNING PER ADVECTION FROM THE NW. WEB CAMS HAVE
SHOWN SOME VSBY REDUCTIONS OVER THE HILLS OUT THAT WAY.
NW WINDS WILL BE QUITE GUSTY THIS AFTERNOON ESPECIALLY ACROSS OUR
EAST...WITH CORE OF STRONGEST BOUNDARY LAYER WINDS PUSHING INTO
THE DAKOTAS. LOOKS LIKE WIDESPREAD 35-45 MPH GUSTS EAST OF
BILLINGS. CURRENT FORECAST HAS COVERED WELL.
ANY -SHSN ACTIVITY SHOULD BE OVER BY LATE AFTERNOON...LEADING TO A
DRY NIGHT TONIGHT WITH MUCH COLDER TEMPS/LIGHTER WINDS AS SFC
RIDGE BUILDS IN. WILL HAVE TO SEE HOW FAR WEST COLD ADVECTION
PUSHES DURING THE DAY AS THIS WILL IMPACT LOWS TONIGHT AND
LOCATION OF LEE SIDE TROF WHEN IT DEVELOPS.
JKL
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
EXTENDED MODELS IN OVERALL AGREEMENT WITH LARGE-SCALE FEATURES
BUT DIFFER IN SOME PARTICULAR DETAILS. A STRONG COLD FRONT WILL
SWEEP ACROSS THE FORECAST AREA LATE SATURDAY AFTERNOON INTO
SATURDAY EVENING. AHEAD OF THE FRONT...EXPECT GUSTY SOUTHWEST TO
WEST WINDS ALONG WITH DOWNSLOPE WARMING...ALTHOUGH TEMPERATURES
WILL NOT WARM TOO MUCH. HIGH TEMPERATURES WILL BE TRICKY DEPENDING
ON TIMING OF THE FRONT BUT MOST PLACES SHOULD RISE INTO THE UPPER
30S TO LOWER 40S.
THE FRONT WILL BRING RAIN AND SNOW SHOWERS WITH THE PRECIP
CHANGING TO ALL SNOW BY LATE SATURDAY NIGHT. AN EASTERLY UPSLOPE
FLOW AND FRONTOGENESIS BAND DEVELOP LATE SATURDAY NIGHT THROUGH
SUNDAY ACROSS MOST OF THE FORECAST AREA BUT ESPECIALLY ALONG THE
EASTERN SLOPES OF THE BEARTOOTH/ABSAROKA MOUNTAINS TO THE BIG
HORNS. THE AREA SHOULD SEE WIDESPREAD SNOW LATE SATURDAY NIGHT
THROUGH THE ENTIRE DAY SUNDAY BEFORE TAPERING OFF BY MONDAY
MORNING. AT THIS TIME...ADVISORY TYPE ACCUMULATIONS LOOK LIKELY
FOR MANY LOCATIONS. TEMPERATURES ARE NOT VERY COLD WITH THIS
SYSTEM RESULTING IN SNOW RATIOS AROUND 10:1 FOR MOST OF THE EVENT
WITH SOME HIGHER RATIOS SUNDAY NIGHT.
THE SYSTEM LOOKS TO BE DIFFERENT FROM WHAT OUR AREA USUALLY SEES
WITH A COLD FRONT AND SNOW IN THAT TEMPERATURES ARE NOT EXPECTED
TO GET VERY COLD LIKE USUALLY IS THE CASE WITH A FRONT DROPPING
OUT OF CANADA THIS TIME OF YEAR. TEMPERATURES MONDAY ARE STILL
EXPECTED TO REBOUND INTO THE UPPER 20S TO LOWER 30S AFTER MORNING
LOWS IN THE TEENS. UNSETTLED NORTHWEST FLOW ALOFT LOOKS TO BE OVER
THE FORECAST AREA TUESDAY INTO WEDNESDAY WITH A POSSIBLE RIDGE AND
WARMER TEMPERATURES BUT LATE NEXT WEEK. HOOLEY
&&
.AVIATION...
REINFORCING COLD FRONT LOCATED FROM LEWISTOWN TO SOUTH OF MILES
CITY AND BAKER WILL CONTINUE TO SLIDE SOUTH TODAY. FRONT WILL
LIKELY BACK TO A POSITION JUST EAST OF LIVINGSTON AND ALONG THE
BEARTOOTH FRONT BEFORE BECOMING STATIONARY THIS EVENING. LOW LEVEL
MOISTURE WILL BRING WIDESPREAD MVFR TO OCCASIONAL IFR CEILINGS
BEHIND THIS FRONT...ALONG WITH SCATTERED SNOW SHOWERS EAST OF A
ROUNDUP TO HARDIN LINE. TO THE WEST OF THE FRONT WEST TO NORTHWEST
WINDS WILL BE GUST TO AROUND 30 KTS AT TIMES...WHILE A NORTH TO
NORTHEAST WIND WILL FILL IN BEHIND THE FRONT.
FOR KMLS TAF LOCATION...IFR VISIBILITY FOG HAS DEVELOPED BEHIND
THE RECENT COLD FRONTAL PASSAGE. EXPECT THIS FOG TO LIFT AS
SCATTERED SNOW SHOWERS MOVE INTO THE AREA BY MID DAY. HOWEVER AN
MVFR TO IFR STRATUS CEILING WILL PERSIST...LIKELY THROUGH LATE
TONIGHT.
FOR KBIL TAF LOCATION...COLD FRONT WAS 50NM TO THE NORTH OF THE
AIRPORT AT 16Z. WEST WINDS GUSTING TO 30 KTS WILL PERSIST UNTIL
FRONTAL PASSAGE...AROUND 19Z. ONCE THE FRONT MOVES THROUGH EXPECT
WINDS TO TURN NORTHEASTERLY AND MVFR CEILING TO DEVELOP. MVFR
CEILINGS WILL PERSIST THROUGH LATE TONIGHT. CHAMBERS
&&
.PRELIMINARY POINT TEMP/POPS...
TDY FRI SAT SUN MON TUE WED
-------------------------------------------------------
BIL 041 022/051 037/051 031/034 020/031 016/035 021/040
0/N 00/B 04/W 67/S 73/J 12/J 32/W
LVM 038 022/050 038/046 028/033 018/031 014/033 022/039
0/N 00/N 06/W 78/S 74/J 12/J 32/W
HDN 043 017/051 030/052 030/036 020/032 014/035 020/041
1/N 00/B 04/W 67/S 73/J 11/B 22/W
MLS 032 011/040 028/049 028/030 017/028 014/031 020/036
3/J 00/B 02/W 46/S 42/J 11/B 21/B
4BQ 038 011/044 029/052 029/035 018/029 014/033 020/039
3/J 00/U 02/W 67/S 63/J 11/B 21/B
BHK 032 007/036 026/047 025/027 015/026 013/029 018/036
3/J 00/U 00/B 36/S 41/E 11/B 11/B
SHR 038 015/049 028/052 027/033 018/029 011/032 018/041
2/J 00/U 03/W 67/S 73/J 11/B 22/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
238 PM CST THU NOV 22 2012
.DISCUSSION...
THE ARCTIC FRONT APPEARS TO BE ENTERING NWRN SD THIS AFTN. THE
LATEST NAM AND RAP SOLNS SHOW THIS FRONT DROPPING THRU NCNTL NEB
THIS EVENING WITH WINDS ALOFT INCREASING TO 65KT AT 700MB...50KT
AT 850MB AND 25 TO 30KT AT 500M AGL. SO SFC WINDS COULD RUN 25 TO
30 MPH ALONG THE FRONT AND POTENTIAL GUSTS TO 45 MPH. THUS THE
WIND ADVISORY WILL BE EXTENDED ACROSS PARTS OF NCNTL NEB TONIGHT
IN ANTICIPATION OF THIS FRONTAL PASSAGE.
ARCTIC HIGH PRESSURE SLIDES THROUGH THE MISSOURI BASIN FRIDAY AND
INTO THE MID SOUTH BY SATURDAY MORNING. WITH THE ARCTIC HIGH
BUILDING THROUGH THE MISSOURI BASIN...THE COLD CORE NEVER REACHES
FAR WESTERN NEB SO A QUICK TEMPERATURE REBOUND CAN OCCUR SATURDAY
AS NEW LOW PRESSURE TRACKS THROUGH SRN SASKATCHEWAN AND MANITOBA
TURNING TO THE WEST ACROSS THE FCST AREA.
THIS LOW THEN DROPS ANOTHER ARCTIC FRONT INTO SOUTH DAKOTA SUNDAY
WITH NW FLOW ALOFT MAINTAINING A BAROCLINIC ZONE AND WEAK MID
LEVEL FRONTOGENESIS DEVELOPING. THE SFC FRONT IS FCST TO DROP
THROUGH NRN NEB SUNDAY AFTERNOON AND THE MODELS SUGGEST
SUFFICIENT LOW LEVEL MOISTURE FOR A CHANCE OF LIGHT RAIN OR SNOW
SUNDAY AFTERNOON CHANGING TO SNOW SUNDAY NIGHT AND ENDING MONDAY
MORNING. LIGHT ACCUMULATIONS WOULD DEVELOP GIVEN THE FLEETING
NATURE OF THE MID LEVEL FRONT...THE OPEN WAVE AT 700MB SHOWN BY
ALL MODELS AND 250 MB JET MAX MOVING THROUGH SRN NEB.
WEAK ARCTIC HIGH PRESSURE MOVES QUICKLY THROUGH THE FCST AREA TUESDAY
FOLLOWED BY ANOTHER LOW PRESSURE SYSTEM TRACKING ALONG THE
CANADIAN BORDER WEDNESDAY. THIS SYSTEM WILL PULL ANOTHER FAST
MOVING ARCTIC HIGH PRESSURE SYSTEM INTO THE FCST AREA FOR NEXT THURSDAY.
SAVE FOR ISOLATED FLURRIES WITH THE ARCTIC FRONT TONIGHT AND LIGHT
SNOW POSSIBLE LATE SUNDAY AND MONDAY MORNING...THE FORECAST IS
DRY. TEMPERATURES RANGE FROM 30S AND 40S NORTHEAST TO 40S AND 50S
SOUTHWEST.
&&
.AVIATION...
WINDS WILL CONTINUE TO BE THE PRIMARY AVIATION CONCERN THROUGH
FRIDAY. STRONG NORTHWEST TO NORTHERLY WINDS WILL CONTINUE THROUGH
THEN AFTERNOON AS A TIGHT PRESSURE GRADIENT AND GOOD MIXING OCCURS
ACROSS THE AREA. WINDS WILL DIMINISH FOR A PERIOD THIS EVENING...
THEN EXPECT ANOTHER INCREASE IN WINDS LATER IN THE EVENING AND
INTO THE OVERNIGHT PERIODS /ROUGHLY 03Z TO 08Z/ AS A FRONT MOVES
THROUGH THE REGION FROM NORTH TO SOUTH. THE STRONGEST WINDS ARE
EXPECTED OVER NORTH CENTRAL NEBRASKA...INCLUDING THE KVTN TAF SITE.
WINDS IN THESE AREAS COULD AGAIN GUST UP TO 45 MPH. WINDS WILL
DIMINISH BY MORNING WITH BENIGN AVIATION WEATHER CONDITIONS FOR
FRIDAY.
&&
.FIRE WEATHER...
OBSERVATIONS ACROSS WESTERN NEBRASKA HAVE GOTTEN NEAR RED FLAG
CRITERIA THIS AFTERNOON AS WINDS GUSTED BETWEEN 35 AND 45
MPH...WHILE DEW POINTS DROPPING INTO THE SINGLE DIGITS AND LOW TEENS
LOWERED RELATIVE HUMIDITY INTO THE UPPER TEENS AND LOW 20S.
HOWEVER...COLDER AIR WAS IN PLACE...WITH TEMPERATURES ONLY IN THE
MID AND UPPER 40S. ALTHOUGH CONDITIONS ARE CLOSE...AND MAY EVEN HIT
CRITERIA IN LOCALIZED SPOTS FOR A FEW HOURS...THESE LOWER
TEMPERATURES WILL KEEP FROM ISSUING A SHORT FUSED RED FLAG WARNING
FOR THE REMAINDER OF THE AFTERNOON. THAT BEING SAID...WITH THE
STRONG WINDS...ANY FIRES WILL STILL HAVE THE POTENTIAL TO SPREAD
RAPIDLY THIS AFTERNOON.
BEYOND TODAY...SATURDAY COULD SEE ELEVATED FIRE WEATHER CONDITIONS
WITH RELATIVE HUMIDITY DROPPING INTO THE UPPER TEENS AND
20S...HOWEVER WINDS ARE ONLY FORECAST AT 15 TO 20 MPH AT THE PEAK.
OTHERWISE THE REMAINDER OF THE NEXT 7 DAYS SHOULD BE QUIET FOR FIRE
CONCERNS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY UNTIL 6 PM CST
/5 PM MST/ THIS EVENING FOR
NEZ004-022>024-035>037-056>059-069>071-094.
WIND ADVISORY UNTIL 4 AM CST FRIDAY FOR NEZ005>010-025>029-038.
&&
$$
SHORT TERM/EXTENDED...CDC
AVIATION...BROOKS