Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/18/12
AREA FORECAST DISCUSSION
NWS MIAMI FL
1015 PM EST SAT NOV 17 2012
.UPDATE...
NO MAJOR UPDATES TO THE PREVIOUS FORECAST ARE EXPECTED THIS
EVENING. THE EVENING SURFACE ANALYSIS SHOWED A LINGERING WEAK
TROUGH OR WHAT IS LEFT OF AN OLD FRONTAL BOUNDARY JUST EAST OF THE
FLORIDA PENINSULA WITH LIGHT TO MODERATE NORTHEAST FLOW
CONTINUING. ENHANCED LOW-LEVEL CONVERGENCE NEAR AND AROUND THIS
SURFACE FEATURE COMBINED WITH BELOW AVERAGE MID/UPPER-LEVEL
TEMPERATURES WILL MAINTAIN THE CHANCE FOR MAINLY ISOLATED SHOWERS
OVER THE ADJACENT ATLANTIC WATERS AND COASTAL AREAS THROUGH THE
OVERNIGHT HOURS. SIMILAR TO THE PAST FEW NIGHTS...INLAND FOG WILL
BE POSSIBLE THROUGH THE OVERNIGHT HOURS ACROSS THE INTERIOR AREAS.
THE LATEST SREF MODEL PROBABILITIES SUPPORT THIS AND INDICATE A
GOOD PORTION OF THIS INTERIOR AREA AROUND AND SOUTH OF THE LAKE
DIPPING INTO THE 1-3 MILE VISIBILITY RANGE BY DAYBREAK SUNDAY.
85/AG
&&
.PREV DISCUSSION... /ISSUED 644 PM EST SAT NOV 17 2012/
AVIATION...
AS A STALLED FRONTAL BOUNDARY LINGERS JUST OFFSHORE THE ATLANTIC
COAST...ISOLATED SHOWERS WILL REMAIN ACROSS THE AREA THROUGH THE
NIGHT AND IS DEPICTED BY THE LATEST HRRR GUIDANCE. SHOWERS COULD
BRIEFLY AFFECT ONE OR MORE EAST COAST SITES THROUGH THE EVENING
WITH MVFR CONDITIONS BUT WOULD BE VERY BRIEF AND DECIDED NOT TO
PREVAIL ANY SHRA MENTION. MID LEVEL DRYING EXPECTED TO PUSH INTO
THE SOUTH FLORIDA PENINSULA FROM THE NORTH THROUGH THE LATTER HALF
OF THE PERIOD.
PREV DISCUSSION... /ISSUED 246 PM EST SAT NOV 17 2012/
DISCUSSION...
SHORT TERM...THE BASIC SYNOPTIC SETUP OVER THE AREA IS A
NORTHWESTERLY FLOW OVER THE CWA AS HIGH PRESSURE TO THE NORTH
SLOWLY PUSHES A LOW PRESSURE SYSTEM WELL TO THE SOUTHEAST
EASTWARD. THERE IS A STALLED BOUNDARY THAT CONTINUES TO LAY
ACROSS THE OFFSHORE WATERS IN THE ATLANTIC. THE HIGH, CENTERED
OVER NEW ENGLAND, IS VERY SLOWLY CAUSING THE BOUNDARY TO DRIFT TO
THE EAST AND HAS PUSHED MOST OF THE SHOWERS AWAY FROM THE CWA.
THIS BOUNDARY WILL NOT GO FAR, HOWEVER, AS THERE IS NO REAL PUSH
NORMAL TO THE BOUNDARY. RATHER, THE FLOW IS ALMOST PARALLEL TO THE
BOUNDARY. SO, WITH STILL PLENTY OF MOISTURE REMAINING OVER THE
MAINLAND, DAYTIME HEATING WILL CAUSE SOME ISOLATED SHOWERS TO
DEVELOP. MODELS ARE INDICATING MOST OF ANY CONVECTION WILL BE
LOCATED MAINLY OFF SHORE. THIS PATTERN WILL BE IN PLACE FOR THE
REMAINDER OF THE WEEKEND.
OVER THE NEXT COUPLE OF DAYS, THE LOW WILL SLOWLY MOVE TO THE
NORTH AS THE HIGH PRESSURE SLIDES WELL TO THE NORTHEAST. THE LOW
WILL THEN DEEPEN AND INTERACT WITH THE STALLED BOUNDARY, TURNING
IT INTO A COLD FRONT. THIS COULD ALLOW FOR SOME SHOWERS OVER THE
ATLANTIC TO DEVELOP, BUT STILL LOOK ISOLATED AT BEST THROUGH 12Z
TUESDAY.
ALSO, WITH THE LOW DEVELOPING NEXT WEEK, SOMEWHAT COOLER, DRIER
AIR WILL TRY TO MAKE ITS WAY DOWN THE FLORIDA PENINSULA. WHILE
THE TEMPERATURES WILL ONLY COOL A COUPLE OF DEGREES, THE DEW
POINTS SHOULD DROP AROUND 5 DEGREES, ALLOWING THE AIR TO FEEL
SOMEWHAT DRIER FOR THE BEGINNING OF THE WEEK.
LONG TERM...TUESDAY THROUGH FRIDAY...DRY AND STABLE AIR OVER S FLA
TUESDAY PRECLUDES PRECIPITATION EXCEPT FOR THE E COAST. BY WEDNESDAY
THE APPROACHING UPPER TROUGH SHOVES A COLD FRONT TOWARD S FLA
THAT MOVES THROUGH THE AREA WEDNESDAY WITH SOME SHOWER ACTIVITY.
THURSDAY AND FRIDAY WILL BE DRY BUT COOLER. LOWS THURSDAY WILL RANGE
FROM NEAR 50 W OF LAKE OKEECHOBEE TO THE LOWER 60S SE WITH SLIGHTLY
WARMER TEMPERATURES FRIDAY MORNING. HIGHS WILL BE IN THE 70S
THURSDAY AND FRIDAY.
MARINE...
NNE TO NE WINDS AT 10 TO 15 KTS THROUGH MONDAY THEN SHIFTING MORE
NORTHERLY AND SLIGHTLY DECREASING TUESDAY BEFORE INCREASING FROM THE
NW WEDNESDAY BEHIND THE FRONT WITH MARINE CONDITIONS DETERIORATING.
SOME RISK OF RIP CURRENTS POSSIBLE E COAST TODAY...SUNDAY AND
MONDAY. WATERSPOUTS POSSIBLE ATLC WATERS TODAY AS OFFSHORE FLOW
CONVERGING WITH THE EASTERLY ATLC FLOW OFFSHORE.
FIRE WEATHER...
NO FIRE WEATHER CONCERNS ARE CURRENTLY ANTICIPATED. LOW PRESSURE
TO THE SOUTH, WILL SLOWLY MOVE TO THE NORTH, WELL EAST OF THE
BAHAMAS. THIS WILL ALLOW SLIGHTLY DRIER AIR TO MOVE IN NEXT WEEK,
WITH SLIGHTLY COOLER TEMPERATURES AS WELL. WINDS, OVER THE NEXT FEW
DAYS, WILL CONTINUE TO BE OUT OF THE NORTH NORTHEAST BETWEEN 5 AND
10 KTS. THEY WILL BECOME MORE NORTH TO NORTHWESTERLY BY MONDAY,
STILL BETWEEN 5 AND 10KTS. AS FOR MINIMUM RH, EXPECT RH`S IN THE
MID 50 PERCENT RANGE FOR THE WEEKEND, DROPPING INTO THE MID 40 TO
LOW 50 PERCENT RANGE BEGINNING NEXT WEEK. RECOVERIES SHOULD
CONTINUE TO BE GOOD EVERY NIGHT, REACHING INTO THE 90 PERCENT
RANGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 66 80 63 79 / 30 20 10 -
FORT LAUDERDALE 68 80 65 79 / 30 20 10 10
MIAMI 66 81 65 79 / 20 20 10 -
NAPLES 62 80 61 75 / 10 10 10 -
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS MIAMI FL
644 PM EST SAT NOV 17 2012
.AVIATION...
AS A STALLED FRONTAL BOUNDARY LINGERS JUST OFFSHORE THE ATLANTIC
COAST...ISOLATED SHOWERS WILL REMAIN ACROSS THE AREA THROUGH THE
NIGHT AND IS DEPICTED BY THE LATEST HRRR GUIDANCE. SHOWERS COULD
BRIEFLY AFFECT ONE OR MORE EAST COAST SITES THROUGH THE EVENING
WITH MVFR CONDITIONS BUT WOULD BE VERY BRIEF AND DECIDED NOT TO
PREVAIL ANY SHRA MENTION. MID LEVEL DRYING EXPECTED TO PUSH INTO
THE SOUTH FLORIDA PENINSULA FROM THE NORTH THROUGH THE LATTER HALF
OF THE PERIOD.
&&
.PREV DISCUSSION... /ISSUED 246 PM EST SAT NOV 17 2012/
DISCUSSION...
SHORT TERM...THE BASIC SYNOPTIC SETUP OVER THE AREA IS A
NORTHWESTERLY FLOW OVER THE CWA AS HIGH PRESSURE TO THE NORTH
SLOWLY PUSHES A LOW PRESSURE SYSTEM WELL TO THE SOUTHEAST
EASTWARD. THERE IS A STALLED BOUNDARY THAT CONTINUES TO LAY
ACROSS THE OFFSHORE WATERS IN THE ATLANTIC. THE HIGH, CENTERED
OVER NEW ENGLAND, IS VERY SLOWLY CAUSING THE BOUNDARY TO DRIFT TO
THE EAST AND HAS PUSHED MOST OF THE SHOWERS AWAY FROM THE CWA.
THIS BOUNDARY WILL NOT GO FAR, HOWEVER, AS THERE IS NO REAL PUSH
NORMAL TO THE BOUNDARY. RATHER, THE FLOW IS ALMOST PARALLEL TO THE
BOUNDARY. SO, WITH STILL PLENTY OF MOISTURE REMAINING OVER THE
MAINLAND, DAYTIME HEATING WILL CAUSE SOME ISOLATED SHOWERS TO
DEVELOP. MODELS ARE INDICATING MOST OF ANY CONVECTION WILL BE
LOCATED MAINLY OFF SHORE. THIS PATTERN WILL BE IN PLACE FOR THE
REMAINDER OF THE WEEKEND.
OVER THE NEXT COUPLE OF DAYS, THE LOW WILL SLOWLY MOVE TO THE
NORTH AS THE HIGH PRESSURE SLIDES WELL TO THE NORTHEAST. THE LOW
WILL THEN DEEPEN AND INTERACT WITH THE STALLED BOUNDARY, TURNING
IT INTO A COLD FRONT. THIS COULD ALLOW FOR SOME SHOWERS OVER THE
ATLANTIC TO DEVELOP, BUT STILL LOOK ISOLATED AT BEST THROUGH 12Z
TUESDAY.
ALSO, WITH THE LOW DEVELOPING NEXT WEEK, SOMEWHAT COOLER, DRIER
AIR WILL TRY TO MAKE ITS WAY DOWN THE FLORIDA PENINSULA. WHILE
THE TEMPERATURES WILL ONLY COOL A COUPLE OF DEGREES, THE DEW
POINTS SHOULD DROP AROUND 5 DEGREES, ALLOWING THE AIR TO FEEL
SOMEWHAT DRIER FOR THE BEGINNING OF THE WEEK.
LONG TERM...TUESDAY THROUGH FRIDAY...DRY AND STABLE AIR OVER S FLA
TUESDAY PRECLUDES PRECIPITATION EXCEPT FOR THE E COAST. BY WEDNESDAY
THE APPROACHING UPPER TROUGH SHOVES A COLD FRONT TOWARD S FLA
THAT MOVES THROUGH THE AREA WEDNESDAY WITH SOME SHOWER ACTIVITY.
THURSDAY AND FRIDAY WILL BE DRY BUT COOLER. LOWS THURSDAY WILL RANGE
FROM NEAR 50 W OF LAKE OKEECHOBEE TO THE LOWER 60S SE WITH SLIGHTLY
WARMER TEMPERATURES FRIDAY MORNING. HIGHS WILL BE IN THE 70S
THURSDAY AND FRIDAY.
MARINE...
NNE TO NE WINDS AT 10 TO 15 KTS THROUGH MONDAY THEN SHIFTING MORE
NORTHERLY AND SLIGHTLY DECREASING TUESDAY BEFORE INCREASING FROM THE
NW WEDNESDAY BEHIND THE FRONT WITH MARINE CONDITIONS DETERIORATING.
SOME RISK OF RIP CURRENTS POSSIBLE E COAST TODAY...SUNDAY AND
MONDAY. WATERSPOUTS POSSIBLE ATLC WATERS TODAY AS OFFSHORE FLOW
CONVERGING WITH THE EASTERLY ATLC FLOW OFFSHORE.
FIRE WEATHER...
NO FIRE WEATHER CONCERNS ARE CURRENTLY ANTICIPATED. LOW PRESSURE
TO THE SOUTH, WILL SLOWLY MOVE TO THE NORTH, WELL EAST OF THE
BAHAMAS. THIS WILL ALLOW SLIGHTLY DRIER AIR TO MOVE IN NEXT WEEK,
WITH SLIGHTLY COOLER TEMPERATURES AS WELL. WINDS, OVER THE NEXT FEW
DAYS, WILL CONTINUE TO BE OUT OF THE NORTH NORTHEAST BETWEEN 5 AND
10 KTS. THEY WILL BECOME MORE NORTH TO NORTHWESTERLY BY MONDAY,
STILL BETWEEN 5 AND 10KTS. AS FOR MINIMUM RH, EXPECT RH`S IN THE
MID 50 PERCENT RANGE FOR THE WEEKEND, DROPPING INTO THE MID 40 TO
LOW 50 PERCENT RANGE BEGINNING NEXT WEEK. RECOVERIES SHOULD
CONTINUE TO BE GOOD EVERY NIGHT, REACHING INTO THE 90 PERCENT
RANGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 66 80 63 79 / 20 20 10 -
FORT LAUDERDALE 68 80 65 79 / 20 20 10 10
MIAMI 66 81 65 79 / 20 20 10 -
NAPLES 62 80 61 75 / 10 10 10 -
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
627 PM EST SAT NOV 17 2012
.SYNOPSIS...
HIGH PRESSURE WILL KEEP DRY CONDITIONS AND SLIGHTLY ABOVE NORMAL
TEMPERATURES ACROSS THE REGION THROUGH THANKSGIVING. A WEAK FRONT
WILL CROSS THE AREA LATER FRIDAY INTO SATURDAY PRODUCING ONLY A
SMALL CHANCE OF A SHOWER.
&&
.NEAR TERM /THROUGH SUNDAY/...
630 PM UPDATE...WITH CLEAR SKIES AND LIGHT WINDS...LOWERED
MINIMUM TEMPERATURES FOR MOUNTAIN AREAS GARRETT AND NORTHERN WEST
VIRGINIA. DOESN`T LOOK LIKE CIRRUS FROM COASTAL SYSTEM WILL EVEN
MAKE IT TO SE COUNTIES AND HRRR CONCURS.
REST OF DISCUSSION FOLLOWS...
A RIDGE OF HIGH PRESSURE EXTENDS FROM QUEBEC SOUTHWEST INTO THE
MISSISSIPPI RIVER VALLEY. EXCEPT FOR A PASSING HIGH CLOUD...CLEAR
SKIES ARE EXPECTED THROUGH THE NEXT 24 HOURS. FORECAST IS
GENERALLY PERSISTENCE...WITH OVERNIGHT LOWS DROPPING BELOW
FREEZING WITH CLEAR SKIES AND LIGHT WINDS ALLOWING FOR GOOD
RADIATIONAL COOLING...AND SUNDAY/S HIGHS CLIMBING A DEGREE OR TWO
FROM TODAY/S READINGS.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
QUIET WEATHER PERSISTS. CLOUDS WILL BE THE MAIN FORECAST CHALLENGE
OF THE SHORT TERM...ESPECIALLY MONDAY NIGHT INTO TUESDAY. LOW
PRESSURE OFF THE SERN CONUS WILL HAVE NO EFFECT OVER OUR AREA
OUTSIDE PASSING ALTOCU OR CIRRUS IN THE AFOREMENTIONED TIME FRAME.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
HIGHLIGHTS...
- MEDIUM TO HIGH CONFIDENCE
- NO BIG STORMS OVER THE LONG HOLIDAY WEEKEND
- NEAR NORMAL TEMPERATURES
- FOLLOWED ECMWF
EXTENDED FORECAST REMAINS RATHER UNEVENTFUL WHICH IS GOOD GIVEN THE
TIME OF YEAR AND THE LARGE NUMBER OF PEOPLE OUT TRAVELING FOR THE
UPCOMING HOLIDAY WEEKEND. UPPER LEVEL IMPULSES CROSS
WEDNESDAY...BUT WITH MOISTURE CONVERGENCE VECTORS ORIGINATING FROM
THE LAKES AND SRN CANADA...DO NOT EXPECT MUCH QPF...IF ANY AT ALL.
A TRANSITORY H5 ANTI-CYCLONE ALLOWS A SUNNY AND MILD TURKEY DAY.
THE NEXT SYNOPTIC FEATURE WILL BE A WEAK BAROCLINIC ZONE THE SECOND
HALF OF FRIDAY. AGAIN...NOT MUCH IN THE WAY OF MOISTURE WITH THIS
SYSTEM SO EXPECT MINIMAL QPF AT BEST. NW FLOW RESULTING FROM FAIRLY
SIGNIFICANT HEIGHT FALLS OVER NEW ENGLAND ALLOW FOR LAKE EFFECT
RW/SW TO DEVELOP SAT N OF I-80. H8 TEMPS AT THIS TIME ARE PROGGED IN
THE -8 TO -10C RANGE...BUT DUE TO LESS THAN OPTIMAL INVERSION
HEIGHTS...LITTLE ACCUMULATION IS PROJECTED SATURDAY.
&&
.AVIATION /23Z SATURDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL ALLOW CLEAR SKIES AND LIGHT WINDS THROUGH THE
TAF PERIOD.
.OUTLOOK.../SUNDAY THROUGH THURSDAY/...
THE NEXT CHANCE FOR RESTRICTIONS IS EXPECTED BY TUESDAY WITH A
CROSSING DISTURBANCE...ALTHOUGH LIKELIHOOD OF RESTRICTIONS APPEARS
LOW AT THIS TIME.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
651 AM EST FRI NOV 16 2012
.SYNOPSIS...
ISSUED AT 310 AM EST FRI NOV 16 2012
QUIET AND SEASONABLE WEATHER IS EXPECTED THROUGH THE COMING WEEKEND
AND LIKELY THROUGH THE THANKSGIVING DAY HOLIDAY. A GOOD DEAL OF
SUNSHINE WITH TEMPERATURES AROUND 50 OR INTO THE 50S CAN BE EXPECTED
THROUGH MONDAY. THERE IS A LOW CHANCE OF SOME RAIN DURING THE MID
PORTION OF THE WEEK NEXT WEEK WITH A COUPLE OF WEAK SYSTEMS.
TEMPERATURES WILL REMAIN MILD THROUGH THANKSGIVING.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 310 AM EST FRI NOV 16 2012
FORECAST CHALLENGES ARE RATHER MINIMAL THROUGH THE SHORT TERM WITH
THE QUIET PATTERN IN PLACE. THE BIGGEST CONCERNS ARE PROBABLY FOG
POTENTIAL AND CLOUD TRENDS THROUGH THE PERIOD.
MOST SITES HAVE SOME REDUCTION IN VISIBILITY DUE TO LIGHT FOG THIS
MORNING. MOST SITES ARE REMAINING ABOVE 3 MILES. A COUPLE OF SITES
HAVE DROPPED DOWN INTO TRUE FOG BELOW A MILE. SO FAR...THIS SEEMS
ISOLATED ENOUGH THAT A MENTION IN THE ZONES WILL SUFFICE.
SOME CLOUDS WILL BE POSSIBLE TODAY AS THE WEAK FRONT CURRENTLY
ACROSS NW LOWER MICHIGAN HAS SOME CLOUDS ASSOCIATED WITH IT THIS
MORNING. LIKELY AIDING THE CAUSE FOR THESE CLOUDS IS SOME OVER LAKE
INSTABILITY WITH DELTA T/S AROUND 10-11C THIS MORNING AND A SW FLOW
AHEAD OF THE FRONT. WINDS WILL BECOME NE BEHIND THE FRONT...AND
THERE COULD BE SOME CONTRIBUTION OF MOISTURE FROM LAKE HURON. THE
ADDITIONAL MOISTURE AND LIGHT WINDS COULD ALLOW FOR SOME FOG ONCE
AGAIN TONIGHT.
THIS FRONT WILL SLOW DOWN ACROSS THE CWFA THIS AFTERNOON...BEFORE
HEADING BACK NORTH OF THE AREA ON SAT. THIS OCCURS AS THE SFC RIDGE
AXIS SHIFTS EAST OF THE AREA AND RETURN FLOW SETS UP. THE PATTERN
WILL REMAIN LIKE THIS THROUGH SUNDAY AS THE OVERALL PATTERN GETS
BOTTLE NECKED. WE MAY SEE A BATCH OF HIGH CLOUDS PASS ACROSS THE
AREA WITH A WEAK UPPER WAVE...BUT THAT WOULD BE ABOUT IT. HIGHS WILL
WARM INTO THE 50S FOR SAT AND SUN.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 310 AM EST FRI NOV 16 2012
FOR THE MOST PART EXPECT SLOWLY WARMING DAY TO DAY TEMPERATURES AND
LITTLE IF ANY PRECIPITATION THROUGH THANKSGIVING. THERE IS A
MOISTURE STARVED SHORTWAVE THAT CROSSES THE AREA IN THE TUESDAY TIME
FRAME. THAT COULD RESULT IN A FEW SPRINKLES BUT THAT WOULD BE ABOUT
IT.
THERE IS FAIRLY HIGH CONFIDENCE IN THE FORECAST THROUGH THANKSGIVING
SINCE THE MODEL AGREEMENT IN THAT TIME FRAME IS EXCELLENT FROM MODEL
TO MODEL AND RUN TO RUN. HOWEVER MODEL CONTINUITY BREAKS DOWN
SERIOUSLY AFTER THANKSGIVING BUT SINCE WE ONLY ARE FORECASTING OUT
TO THANKSGIVING WE ARE GOOD! WE WILL ADDRESS THIS ISSUE IN LATER
DISCUSSIONS.
AS NOTED YESTERDAY THIS IS A VERY ANOMALOUS PATTERN FOR SOUTHWEST
LOWER MICHIGAN AT THIS TIME YEAR. HAVING SO MANY DAYS IN NOVEMBER
WITH NO MEASURABLE PRECIPITATION IS A LESS THAN 1 IN 10 SORT OF
EVENT.
ALSO AS NOTED YESTERDAY THE PROBLEM IS RELATED TO BLOCKING AT HIGH
LATITUDES. NAMELY THE UPPER HIGH...THAT AT 00Z FRIDAY... WAS NEAR
178E AND 73N. IT IS CAUSING THE NORTHERN BRANCH OF THE POLAR JET TO
STAY NORTH OF 65N AROUND THE HEMISPHERE. THUS LOCKING THE TRULY
WINTER LIKE TEMPERATURES WELL NORTH OF HERE THROUGH THE END OF NEXT
WEEK. THE PRIMARY POLAR JET IS STAYING NEAR THE CANADIAN BOARDER
THROUGH THANKSGIVING. MEANWHILE THE SUB-TROPICAL JET IS DOWN NEAR
THE GULF COAST AND WILL LIKELY STAY THERE UNTIL THANKSGIVING. SO...
UNTIL THAT BLOCKING UPPER HIGH MOVES OUT OF THE WAY THIS OVERALL
MILD AND DRY WEATHER PATTERN WILL CONTINUE HERE OVER SOUTHWEST LOWER
MICHIGAN.
ENJOY THIS MILD WEATHER WHILE YOU CAN....
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 650 AM EST FRI NOV 16 2012
LARGELY MVFR VSBY PREVAILED AT 11Z THIS MORNING. MKG AND AZO ARE
MARGINALLY IFR (2 MILES VSBY). THERE IS ALSO A BAND OF MVFR/IFR
CIGS FROM STRATUS DROPPING SOUTH INTO THE ROUTE 10 AREA HEADING
SOUTH WITH TIME TO0.
DUE TO LIGHT WINDS BEING FORECAST (WINDS UNDER 15 KNOTS THROUGH
5000 FT AGL THROUGH SAT NIGHT) AND THE FEEBLE LATE NOVEMBER
SUNSHINE NOT HELPING OUR MIXING PROCESS MUCH I WOULD EXPECT T0
SEE HAZE CONTINUE INTO LATE MORNING AFTER THE LIGHT FOG BURNS OFF
AFTER SUNRISE. WE MAY HAVE MORE FOG ISSUES TONIGHT SINCE ONCE
AGAIN WINDS REMAIN LIGHT SO THERE IS NOTHING TO MIX OUT THE AIR
OVER US. WHILE IT IS TRUE A FRONT TRIES TO COME TROUGH TODAY IT IS
"BRIDGED" WHICH MEANS IT DISSIPATES SO NOT MUCH HELP THERE.
THE OTHER ISSUE IS THE STRATUS DECK MOVING SOUTH BEHIND THE FRONT.
THE NAM AND RAP MODELS SEEM TO WANT TO MIX THIS OUT BY EARLY
AFTERNOON. SO I CONTINUED THE SAME IDEA THE PREVIOUS SHIFT HAD.
THAT IS TO BRING MVFR CIGS TO MKG BY LATE MORNING AND TEMPO GROUP
IN THE GRR TAFS INTO MID AFTERNOON AFTERNOON.
&&
.MARINE...
ISSUED AT 310 AM EST FRI NOV 16 2012
THE STRONGEST WINDS THROUGH EARLY NEXT WEEK WILL BE UP NORTH OF
WHITEHALL THIS MORNING. A DECENT N-NE GRADIENT WILL HELP WINDS UP TO
20 KNOTS TODAY UP NORTH. BEYOND THAT...WINDS SHOULD GENERALLY REMAIN
AT OR BELOW 15 KNOTS THROUGH MONDAY.
&&
.HYDROLOGY...
ISSUED AT 310 AM EST FRI NOV 16 2012
NO HYDROLOGY ISSUES EXPECTED THROUGH THE PERIOD. NO RAIN EXPECTED
THROUGH MONDAY...AND ONLY A CHANCE OF LIGHT RAIN NEXT WEEK WILL
ALLOW THE AVERAGE TO BELOW AVERAGE RIVER LEVELS TO CONTINUE TO DROP.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...WDM
AVIATION...WDM
HYDROLOGY...NJJ
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS ELKO NV
253 PM PST FRI NOV 16 2012
.SYNOPSIS...A MOIST PACIFIC ONSHORE FLOW WILL COMBINE WITH TWO
WEAK AREAS OF LOW PRESSURE TO BRING UNSETTLED WEATHER TO THE GREAT
BASIN THIS WEEKEND. VALLEY RAIN AND MOUNTAIN SNOW SHOWERS WILL BE
THE NORM...WITH THE HEAVIEST PRECIPITATION EXPECTED ACROSS
HUMBOLDT AND ELKO COUNTIES. PARTIAL CLEARING AND WARM WEATHER
IS EXPECTED FOR THE BEGINNING OF THANKSGIVING WEEK.
&&
.SHORT TERM...FRIDAY NIGHT THROUGH MONDAY. TONIGHT...THE RAP AND
NAM12 ARE PROGGING A BAND OF PRECIPITATION TO DEVELOP ACROSS
CENTRAL NEVADA AND SLOWLY MOVE NORTH THIS EVENING. CURRENT RADAR
IS BEGINNING TO SHOW AN AREA OF RAIN SHOWERS DEVELOPING FROM
EUREKA TO FALLON. HAVE INCREASED POPS AND QPF FOR THIS POSSIBLE
SOLUTION ACROSS CENTRAL NEVADA THIS EVENING.
SATURDAY WILL BE A CLOUDY DAY AS A WEAKENING 500MB TROUGH OFF
THE CALIFORNIA COAST MOVES INTO THE GREAT BASIN. FEATURE IS
DYNAMICALLY WEAK...BUT HAS PWAT VALUES PUSHING OVER .50" TO WORK
WITH...THUS FEELING HUMBOLDT COUNTY COULD PICK UP .10-.30" OF
RAIN TOMORROW WITH ONLY THE HIGHEST TERRAIN EXPECTED TO GET
SNOWFALL. LIGHTER AMOUNTS OF PRECIPITATION WILL FALL ACROSS THE
REMAINING PART OF THE CWA. SATURDAY NIGHT INTO SUNDAY A STRONGER
500MB SHORTWAVE WILL PUSH IN FROM NORTHERN CALIFORNIA AND TRACK
ACROSS NORTHERN NEVADA DURING THE DAY ON SUNDAY. AMPLE ANTECEDENT
MOISTURE AHEAD OF THIS WAVE WILL LEAD TO THE BEST CHANCE FOR
WIDESPREAD PRECIPITATION IN QUITE SOME TIME. SNOW LEVELS WILL
START OUT HIGH ABOVE 7500K ON SATURDAY NIGHT...BEFORE DROPPING
FROM WEST TO EAST DOWN TO 6000K ON SUNDAY. THERE WILL BE A BURST
OF SNOW ACROSS THE HIGHER PASSES OF I-80...MOUNTAIN CITY
HIGHWAY...AND U.S. 93...BUT FEEL AIR TEMPS WILL REMAIN AROUND OR
JUST ABOVE FREEZING. THIS WILL LIMIT THE IMPACTS AND NOT THINKING
ANY WWA HEADLINES WILL BE NEEDED FOR MAJOR TRAVEL CORRIDORS...BUT
ZONE 034 COULD NEED AN ADVISORY WITH 4-6" OF SNOW POSSIBLE FOR THE
EAST HUMBOLDT`S & RUBY MOUNTAINS.
500MB SHORTWAVE QUICKLY PUSHES OUT OF THE AREA SUNDAY NIGHT...WITH
PARTIAL CLEARING EXPECTED ON MONDAY...AS HIGHS WARM BACK UP INTO
THE 50S.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY. THE PERIOD BEGINS WITH A
LARGE UPPER TROUGH OFF THE PACIFIC NORTHWEST COAST WITH RIDGING OVER
THE GREAT BASIN. SOME MOISTURE COMING OUT OF THE UPPER TROUGH WILL
RIDE UP OVER THE RIDGE AND COULD BRING A FEW SHOWERS TO FAR NORTHERN
NEVADA THROUGH WEDNESDAY. AS THE TROUGH COMES ONSHORE LATE WEDNESDAY
AND THURSDAY THE ECMWF KEEPS MOST OF THE ENERGY TO OUR NORTH WHILE
THE GFS DIGS IT FURTHER SOUTH. IN THE FORECAST GRIDS WENT WITH A
BLEND OF THE ECMWF/GFS WITH 15-30 POPS FROM ABOUT I-80 NORTH.
DAYTIME TEMPERATURES WILL REMAIN MILD WITH HIGHS IN THE 50S.
&&
.AVIATION...MOIST SOUTHWEST FLOW ALOFT OVER THE AREA WILL BRING A
FEW SHOWERS. CIGS/VSBYS EXPECTED TO REMAIN VFR.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
95/91/91
AREA FORECAST DISCUSSION
NWS RALEIGH NC
930 PM EST SAT NOV 17 2012
.SYNOPSIS...
STRONG HIGH PRESSURE OVER THE NORTHEAST STATES WILL EXTEND SOUTHWARD
INTO NORTH CAROLINA THROUGH MONDAY... WHILE BRISK NORTHEAST WINDS
BRING A STRONG FLOW OF ATLANTIC MOISTURE INTO THE REGION. COOL AND
CLOUDY CONDITIONS WITH A CHANCE OF RAIN WILL PERSIST INTO TUESDAY...
AS LOW PRESSURE FORMS OFF THE NORTH CAROLINA COAST.
&&
.NEAR TERM /THROUGH SUNDAY NIGHT/...
AS OF 930 PM SATURDAY...
REST OF TONIGHT: COMPLEX PATTERN ACROSS THE SOUTHEAST AND
MIDATLANTIC THIS EVENING... AND THE MAIN FORECAST CONCERN REMAINS
THE CHANCE FOR RAIN OVERNIGHT. SURFACE HIGH PRESSURE REMAINS QUITE
STRONG (OVER 1038 MB) CENTERED OVER THE ST LAWRENCE VALLEY AND
EXTENDING SOUTHWARD THROUGH NC... WHILE A STRENGTHENING LOW LEVEL
FRONTAL ZONE AND DEVELOPING LOW PRESSURE OFF THE SOUTHEAST COAST IS
EXPECTED TO GENERATE A TIGHTENING MSLP GRADIENT OVERNIGHT...
ESPECIALLY OVER THE SRN AND ERN CWA. CONVECTION WAS WIDESPREAD JUST
OFF THE CAROLINA COAST THIS AFTERNOON... AND WHILE THE INTENSITY OF
THIS RAIN HAS DECREASED... IT REMAINS IN PLACE JUST OFF THE SC AND
SRN NC COAST. THE 12Z 4-KM WRF-ARW AND WRF-NMM DID A SUBPAR JOB IN
DEPICTING THIS RAIN... ALTHOUGH THE 18Z LOCAL WRF-ARW DID BETTER AND
IS SIMILAR TO THE LATEST HRRR OUTPUT... WHICH SHOWS THE BULK OF THE
RAIN SHIELD HOLDING OVER AND JUST OFF THE SC COAST WITH JUST PATCHY
RAIN SPREADING INTO OUR FAR SOUTHEAST COUNTIES OVERNIGHT. THIS ALSO
APPEARS IN LINE WITH THE LATEST SREF PROBABILITIES OF MEASURABLE
RAIN... WHICH KEEPS CHANCES UNDER 30 PERCENT IN THE SOUTHEAST
TONIGHT. BASED ON THIS AND MODEL AGREEMENT ON ACCELERATING LOW LEVEL
MOISTURE TRANSPORT TONIGHT AND THE PACE AT WHICH THE LOWER STRATUS
AND SMALLER DEW POINT DEPRESSION AIR IS SPREADING WESTWARD INTO
SOUTHEAST NC... WILL HOLD ONTO A SLIGHT CHANCE OF RAIN TONIGHT IN
THIS AREA. FORECAST SOUNDINGS DEPICT A FAIRLY DEEP (3000-4000 FT
THICK) SURFACE-BASED STABLE LAYER... BUT CLOSE EXAMINATION REVEALS A
VERY SHALLOW (FEW HUNDRED FEET) SLIGHTLY MIXED LAYER RIGHT AT THE
SURFACE... REASONABLE CONSIDERING HOW THE WINDS THROUGHOUT THE
LOWEST FEW THOUSAND FEET WILL BE STRENGTHENING AT ONCE. WILL KEEP
WINDS UP OVERNIGHT WITH PERIODIC GUSTS. THE LOW LEVEL STIRRING WILL
HOLD TEMPS UP... AND EXPECT LOWS OF 38-48. -GIH
SUNDAY AND SUNDAY NIGHT...THE MID LEVEL ANTI-CYCLONE OFF THE
SOUTHERN NEW ENGLAND COAST AND THE NE FL/SRN GA COAST WILL MAINTAIN
A DEEP ELY FLOW INTO CENTRAL NC WITH SPEED CONFLUENCE NOTED OVER THE
REGION DURING THE AFTERNOON-EARLY EVENING HOURS. THE LIFT SUPPLIED
BY THIS CONFLUENCE WILL GENERATE AREAS OF LIGHT RAIN...MAINLY ALONG
THE I-95 CORRIDOR. FARTHER WEST...LIFT WEAKER TO NON-EXISTENT. THIS
WILL LEAD TO PRECIP CHANCES RANGING FROM LIKELY IN THE EAST TO LOW
END CHANCE-SLIGHT CHANCE IN THE FAR WEST LATE SUNDAY INTO SUNDAY
NIGHT.
EXPECT A NARROW DIURNAL TEMP RANGE SUNDAY SUNDAY NIGHT DUE TO CLOUDS
AND PRECIP. MAX TEMPS LOW-MID 50S SUNDAY.MIN TEMPS SUNDAY NIGHT
AROUND 40 NW TO UPPER 40S/NEAR 50 E-SE. -WSS
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 310 PM SATURDAY...
MONDAY AND MONDAY NIGHT...WHILE MID LEVEL ANTI-CYCLONE WILL REMAIN
NEARLY STATIONARY OFF THE NORTHERN MID ATLANTIC COAST...THE AREA OF
LOW PRESSURE OFF THE NE FL COAST WILL LIFT TO THE ENE. THIS MOVEMENT
OF THE LOW WILL CAUSE THE MID LEVEL FLOW OVER CENTRAL NC TO WEAKEN
AND BECOME MORE NELY. THUS...EXPECT RAIN CHANCES TO DWINDLE MONDAY
WITH A SLIGHT CHANCE POP CONFINED TO THE EASTERN HALF BY
AFTERNOON....AND LITTLE IF ANY RAIN EXPECTED MONDAY NIGHT. MODEL
GUIDANCE DIFFERS AS TO THE AMOUNT OF DECREASING CLOUDINESS TO OCCUR
WHICH LEADS TO DISCREPANCIES IN THE TEMP GUIDANCE MONDAY. LATEST NAM
MORE EMPHATIC WITH ITS CLEARING TREND WHICH TRANSLATES TO WARMER
AFTERNOON TEMPS. THE 12Z ECMWF WEAKEN OFFERS A SCENARIO SOMEWHAT BUT
NOT AS EMPHATIC WITH THE AMOUNT OF DRYING. GFS MAINTAINS A SATURATED
AIR MASS THROUGH THE PERIOD. PLACED A BIT MORE EMPHASIS TOT EH GFS
AS POTENTIAL EXIST FOR MOISTURE TO BE TRAPPED BELOW MID LEVEL
SUBSIDENCE INVERSION. THUS WILL FAVOR HIGH TEMPS MONDAY TOWARD THE
COOLER GFS MOS.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 310 PM SATURDAY...
BRIEF S/W RIDING ALOFT AT THE START OF THE MEDIUM RANGE PERIOD IS
EXPECTED TO QUICKLY SHIFT TO THE EAST OF THE AREA ON TUESDAY AS A
PAIR OF MID/UPPER LEVEL DISTURBANCES USHER IN A RETURN TO POSSIBLE
UNSETTLE WEATHER. HOWEVER... AT THE SURFACE/LOW LEVELS OF THE
ATMOSPHERE EXPECT A GENERALLY NORTHERLY FLOW WILL CONTINUE... WITH
THE AFOREMENTIONED SURFACE LOW PRESSURE EXPECTED TO REMAIN OFFSHORE
OR SLOWLY LIFT NORTH OR NORTHEASTWARD. MODELS ARE CONTINUING TO
STRUGGLE THOUGH WRT POSSIBLE LIGHT RAIN FOR TUESDAY INTO TUESDAY
NIGHT. THE DIFFERENCES APPEAR TO BE TIED TO THE STRENGTH IN THE
MID/UPPER LEVEL RIDGING AND APPROACHING NEXT SET OF IMPULSES ALOFT.
FOR NOW WILL TREND THE FORECAST TO THE DRIER SIDE OF GUIDANCE
(CLOSER TO THE ECMWF AND NAM). FOR NOW WILL LOWER POPS TO SLIGHT
CHANCE AREAWIDE. HOWEVER... STILL EXPECT SKIES WILL BE AT LEAST
MOSTLY CLOUDY WHICH WILL STILL HELP SUPPRESS HIGH TEMPS DESPITE LOW
LEVEL THICKNESS VALUES AROUND NORMAL. WILL GO WITH HIGH TEMPS IN THE
UPPER 50S TO AROUND 60... A BIT BELOW NORMAL. HOWEVER... IF THE RAIN
DOES MATERIALIZE EXPECTED TEMPS WOULD BE A GOOD 5 TO 10 DEGREES
COOLER AT LEAST THAN CURRENT FORECAST. LOW TUESDAY NIGHT/WEDNESDAY
MORNING ARE EXPECTED TO BE IN THE LOWER TO MID 40S... WITH SKIES
BEGINNING TO CLEAR AT BIT (MORE SO WEST) AS THE FIRST DISTURBANCE
BEGINS TO PUSH TO THE EAST OF THE AREA.
MID/UPPER LEVEL TROUGH AXIS IS EXPECTED TO AMPLIFY ACROSS THE AREA
AGAIN ON WEDNESDAY AS A SECOND S/W TROUGH ROTATES THROUGH THE AREA
ON WEDNESDAY/WEDNESDAY NIGHT. HOWEVER... DESPITE THE DEEPENING
TROUGH... BEST LIFT AND MOISTURE SHOULD REMAIN TO THE SOUTH OF THE
AREA. THUS... WITH AFTERNOON LOW LEVEL THICKNESS VALUES AROUND
NORMAL AND SKIES BECOMING PARTLY SUNNY LATE IN THE DAY EXPECT HIGH
TEMPS TO BE IN THE UPPER 50S TO LOWER 60S. LOWS WITH CLEARING SKIES
ON THURSDAY MORNING ARE EXPECTED TO RANGE FROM THE MID 30S TO LOWER
40S.
THURSDAY THROUGH SATURDAY:
RIDGING ALOFT IS EXPECTED TO BUILD ACROSS THE AREA DURING THIS
TIMEFRAME... WHILE A NORTHERN STREAM SYSTEM IS EXPECTED TO MOVE
ACROSS THE NORTHERN PORTION OF THE COUNTRY. AT THE SURFACE EXPECT
HIGH PRESSURE WILL REMAIN ACROSS THE AREA THROUGH AT LEAST FRIDAY
MORNING/AFTERNOON... BEFORE A TRAILING DRY COLD FRONT ASSOCIATED
WITH THE NORTHERN STREAM SYSTEM IS EXPECTED TO MOVE THROUGH THE AREA
LATE FRIDAY INTO FRIDAY NIGHT. HIGH PRESSURE IS EXPECTED TO BUILD
INTO THE AREA BEHIND THE FRONT ON SATURDAY. EXPECT ABOVE NORMAL
TEMPS THURSDAY/FRIDAY... WITH NEAR TO SLIGHTLY BELOW NORMAL TEMPS ON
SATURDAY. EXPECT HIGH TEMPS IN THE 60S THURSDAY/FRIDAY TO UPPER 50S
TO AROUND 60 NEXT SATURDAY. LOWS IN THE UPPER 30S TO LOWER 40S...
WITH POSSIBLE MID 30S IN THE USUAL RURAL COOL/COLDER AREAS.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AS OF 700 PM SATURDAY...
ONLY MEDIUM CONFIDENCE IN THE CURRENT AVIATION FORECAST AS LOW
CLOUDS MOVE INTO THE AREA TONIGHT AND LINGER INTO EARLY NEXT WEEK.
THE COMBINATION OF AN UPPER LEVEL WAVE AND A WEAK SURFACE LOW
OFFSHORE WILL LEAD TO STRENGTHENING EAST-NORTHEASTERLY LOW LEVEL
FLOW AS STRATUS SURGES INLAND FROM THE COAST TONIGHT. CEILINGS OVER
THE NC COASTAL PLAIN ARE CURRENTLY AROUND 3K FT AND THESE CEILINGS
WILL REACH KRWI AND KFAY BY 02Z...AND POSSIBLY KRDU BY 06Z...
LOWERING TO IFR BY 12Z. THE LOW LEVEL AIRMASS IS MUCH DRIER TO THE
WEST OF KRDU AND THERE IS LESS CONFIDENCE IN MVFR/IFR CEILINGS
REACHING KGSO/KINT BY 12Z. PRECIP WILL ALSO BEGIN TO SPREAD INLAND
SUNDAY MORNING...WITH KRDU/KRWI/KFAY EXPECTED TO SEE LIGHT RAIN
DURING THE DAY. AGAIN...WITH DRIER AIR OVER WESTERN NC...KGSO AND
KINT MAY BE ON THE EDGE OF THE LIGHT RAIN. WHILE A PERIOD OF IFR
CEILINGS ARE POSSIBLE...CEILINGS SHOULD REMAIN ABOVE 1000KT AND EVEN
RISE A LITTLE DURING THE DAY SUNDAY.
THE OTHER CONCERN DURING THE TAF PERIOD WILL BE STRENGTHENING
NORTHEASTERLY WINDS AND TURBULENCE/LOW LEVEL WIND SHEAR. MODELS ARE
INDICATING THAT WINDS WILL INCREASE BETWEEN THE WEAK LOW OFFSHORE
AND A STRONG HIGH PRESSURE OVER NEW ENGLAND....WITH WINDS AT 2000 FT
AS STRONG AS 40KT FROM KFAY TO KRWI AND EASTWARD SUNDAY AFTERNOON.
THE LOW LEVEL WINDS WILL BE MOSTLY UNIDIRECTIONAL AND WELL MIXED IN
THE BOUNDARY LAYER...SO LOW LEVEL WIND SHEAR CRITERIA MAY NOT BE
MET. HOWEVER...SUSTAINED 10-15KT WINDS WITH GUSTS TO 25KT SHOULD BE
EXPECTED.
OUTLOOK...
LOW CLOUDS ARE EXPECTED TO LINGER THROUGH AT LEAST TUESDAY...WITH
PREDOMINATELY MVFR CONDITIONS....THOUGH IFR CONDITIONS ARE POSSIBLE
MONDAY MORNING. THERE IS SOME UNCERTAINTY AS TO HOW QUICKLY VFR
CONDITIONS WILL RETURN...BUT A GENERAL IMPROVEMENT IS EXPECTED
TUESDAY THROUGH THURSDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD/WSS
SHORT TERM...WSS
LONG TERM...BSD
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
153 PM CST FRI NOV 16 2012
.SHORT TERM...THROUGH MONDAY NIGHT
153 PM CST FRI NOV 16 2012
STRATUS ALONG WITH FOG POTENTIAL WILL BE AN IMMEDIATE CONCERN
TONIGHT...MAINLY ALONG/NORTHEAST OF I-94. FOCUS THEN SHIFTS TO
MILDER PATTERN...ALONG WITH RAIN CHANCES ENTERING THE PICTURE SUNDAY
NIGHT THROUGH MONDAY EVENING.
SURFACE MAP HAS A HIGH PRESSURE RIDGE AXIS EXTENDING FROM SOUTHERN
ONTARIO INTO EASTERN MN/WESTERN IA. VISIBLE SATELLITE AND SURFACE
OBSERVATIONS SHOWING NORTHEAST WIND FETCH ACROSS LAKE MICHIGAN HAS
BROUGHT AREAS OF STRATUS/STRATOCUMULUS INTO PORTIONS OF
EASTERN/CENTRAL WISCONSIN. OTHERWISE...CLEAR/SUNNY SKIES PREVAILED
ACROSS THE REST OF THE AREA THANKS TO THE RIDGE OF HIGH PRESSURE
WITH TEMPERATURES AT 2 PM RANGING FROM THE LOW 40S TO NEAR 50
DEGREES.
16.12Z MODELS IN FAIRLY GOOD AGREEMENT THROUGH THE SHORT TERM..
FOR TONIGHT...WILL BE WATCHING FOR AREAS OF STRATUS/FOG ACROSS
CENTRAL WISCONSIN...MAINLY NORTHEAST OF I-94 AS RIDGE AXIS SLOWLY
SHIFTS INTO THE GREAT LAKES REGION. NAM/RAP IN GOOD AGREEMENT WITH
COOLING/SATURATION IN THE LOWEST 0.5KM AS LIGHT SOUTHEAST FLOW
CONTINUES TO ADVECT MOISTURE OFF OF LAKE MICHIGAN. QUESTION WILL BE
HOW EXPANSIVE LOW CLOUDS AND FOG WILL BE. BESIDES THE NAM/RAP
SHOWING FAIRLY SATURATED CONDITIONS IN THE LOWEST 0.5KM...3 OUT OF 4
MESO-WRF MODELS DEPICTING CIG HEIGHT/VIS INDICATING A FAIRLY STRONG
SIGNAL FOR LOW CLOUD/FOG POTENTIAL. HAVE INCREASED CLOUD COVER FOR
AREAS MAINLY ALONG/NORTHEAST OF I-94 THIS EVENING AND INTO THE EARLY
MORNING HOURS. ALSO ADDED AREAS OF FOG MENTION. NOT CONFIDENT HOW
LOW VISIBILITIES WILL GET. THINKING THERE MAY BE ISOLATED POCKETS OF
DENSER FOG WITH VISIBILITY BELOW A MILE...BUT THINKING 3-5SM SHOULD
BE THE RULE. MODELS THEN SHOW THIS LOW-LEVEL MOISTURE/LOW CLOUD
ADVECTING NORTHEAST OUT OF THE AREA AROUND DAWN WITH INCREASING
PRESSURE GRADIENT/SOUTH WINDS ON THE BACKSIDE OF THE HIGH.
FOCUS THEN SHIFTS TO MODERATING/MILDER TEMPERATURES PUSHING INTO THE
AREA SATURDAY/SUNDAY WITH BREEZY SOUTHERLY FLOW. NAM/GFS SHOWING
925MB TEMPERATURES WARMING FROM 5-7C ON SATURDAY...INTO THE 6-9C
RANGE ON SUNDAY. SOME ALTOCUMULUS WILL BE SEEN FROM TIME TO TIME
SATURDAY THROUGH SUNDAY IN WARM AIR ADVECTION/ISENTROPIC LIFT...BUT
NOT EXPECTED TO HINDER WARMING DURING THE DAY. GIVEN THIS AND
WARMING 925MB TEMPERATURES...PLAN ON HIGHS SATURDAY IN THE LOWER TO
MIDDLE 50S AND IN THE MID-UPPER 50S ON SUNDAY.
ATTENTION THEN TURNS TO RAIN CHANCES SUNDAY NIGH THROUGH MONDAY
NIGHT. MODELS SHOWING GOOD RUN-TO RUN CONSISTENCY WITH MID-LEVEL
TROUGH/WEAK SURFACE COLD FRONT MOVING OUT OF THE PLAINS AND ACROSS
THE AREA. FORCING IS NOT OVERLY STRONG WITH THE TROUGH/FRONT AND NOT
A LOT OF MOISTURE TO WORK WITH. AS A RESULT...IT WILL COME DOWN TO
HOW MUCH THE COLUMN GETS SATURATED GIVEN THE WEAKER FORCING. THE
GFS...MORE THAN THE NAM...SHOWING FAIRLY LIGHT RAINFALL ACROSS THE
AREA WITH AMOUNTS GENERALLY A FEW HUNDRETHS OF AN INCH AT MOST.
GIVEN THIS SIGNAL AND LEVEL OF SATURATION IN QUESTION...WILL KEEP
RAIN PROBABILITIES ON THE LOW SIDE AROUND 30 PERCENT...CENTERED ON
MONDAY.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
153 PM CST FRI NOV 16 2012
16.12Z GFS AND ECMWF CONTINUE THE MILD TREND FOR THE AREA THROUGH
THE LONG TERM AS THE MAIN STORM TRACK STAYS UP IN CANADA. SOME
DIFFERENCE ARISE ON WEAK/DRY COLD FRONTAL PASSAGE
WEDNESDAY/THANKSGIVING DAY TIME FRAME. THE GFS IS A BIT FASTER WITH
THIS PASSAGE TAKING PLACE WEDNESDAY NIGHT WHEREAS THE ECMWF SHOWS
PASSAGE DURING THE DAY ON THANKSGIVING. EITHER WAY AS MENTIONED...
THIS FRONT APPEARS O HAVE A DRY PASSAGE WITH TEMPERATURES
CONTINUING TO TREND WELL ABOVE NORMAL. MODELS THEN HAVE DIFFERENCES
RESOLVING A MID-LEVEL TROUGH MOVING OVER THE RIDGE ON FRIDAY. THE
ECMWF SHOW A MUCH MORE PROGRESSIVE/WEAK TROUGH WORKING ACROSS THE
AREA BY THURSDAY EVENING ALREADY WHEREAS THE GFS SHOW A MUCH MORE
VIGOROUS MID-LEVEL TROUGH/SURFACE LOW MOVING OUT OF THE PLAINS INTO
THE UPPER MISSISSIPPI RIVER VALLEY REGION. MORE WEIGHT PUT INTO THE
ECMWF AT THIS POINT WITH DRY FRIDAY. OTHERWISE AS STATED
EARLIER...LOOK FOR TEMPERATURES TO REMAIN ABOVE NORMAL THROUGH AT
LEAST THANKSGIVING WITH HIGHS IN THE UPPER 40S TO MIDDLE 50S.
&&
.AVIATION...THROUGH 18Z SATURDAY
1125 AM CST FRI NOV 16 2012
SURFACE HIGH PRESSURE WILL DRIFT EASTWARD THIS AFTERNOON AND
TONIGHT RESULTING IN A TIGHTENING PRESSURE GRADIENT AT THE TAF
SITES. LOW LEVEL MOISTURE OFF LAKE MICHIGAN AS DEPICTED IN THE
0-1KM RELATIVE HUMIDITY PROGS FROM THE 16.12Z RAP REMAINS EAST OF
KLSE. THUS HAVE KEPT THE ENTIRE TAF PERIOD WITH CLEAR SKIES. WITH
THE GRADIENT INCREASING...SOUTHEAST WINDS 5 TO 10 KNOTS EXPECTED
TONIGHT AND THEN INCREASING AFTER 15Z SATURDAY...ESPECIALLY AT
KRST WHERE SOME GUSTS TO 22 KNOTS ARE LIKELY BEFORE 18Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
153 PM CST FRI NOV 16 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1125 AM CST FRI NOV 16 2012
.SHORT TERM...THROUGH SUNDAY NIGHT
200 AM CST FRI NOV 16 2012
MAIN FORECAST FOCUS IS ON CLOUD COVER AND TEMPERATURES WITH A QUIET
WEATHER PATTERN IN PLACE.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT
ANALYSIS SHOWED RIDGING FROM NEW MEXICO INTO THE DAKOTAS...A
SHORTWAVE OVER NEVADA...AND SHORTWAVE TROUGHS OVER FAR SOUTHERN
ALBERTA INTO SASKATCHEWAN...AS WELL AS OVER INDIANA. THE FORECAST
AREA LIES IN SUBSIDENCE AND DRYING BEHIND THE LATTER SHORTWAVE
TROUGH. 00Z MPX AND ABR SOUNDINGS WERE QUITE DRY WITH PRECIPITABLE
WATER VALUES AROUND 0.17 INCHES AND DEWPOINT DEPRESSIONS OF 10C OR
MORE THROUGHOUT. THE SUBSIDENCE WAS NOTED AT THE SURFACE BY HIGH
PRESSURE WHICH STRETCHES FROM KANSAS INTO NORTHERN ONTARIO. THE
CLEAR SKIES...LIGHT WINDS AND DRY AIR ASSOCIATED THEN WITH THIS
RIDGE HAS ALLOWED TEMPERATURES TO DROP INTO THE 20S AT MOST
LOCATIONS. TO THE WEST...LITTLE IS GOING ON WITH THE SOUTHERN
ALBERTA/SASKATCHEWAN SHORTWAVE TROUGH EXCEPT FOR SOME CIRRUS.
TODAY AND TONIGHT...THE UPPER RIDGING SEEN OVER THE DAKOTAS IS
FORECAST TO MOVE OVER THE AREA TODAY...THEN TO LAKE ERIE TONIGHT...
IN RESPONSE TO THE SOUTHERN ALBERTA/SASKATCHEWAN SHORTWAVE PUSHING
EAST. ALTHOUGH THIS SETUP PLACES THE FORECAST AREA UNDER SOUTHWEST
FLOW ALOFT...TYPICALLY GOOD FOR PRECIPITATION...THE EXTENSIVE
AMOUNT OF DRY AIR PRESENT WILL PREVENT ANY PRECIPITATION FROM
OCCURRING. IN FACT...WE MAY NOT SEE MUCH CLOUD COVER BESIDES SOME
SCATTERED HIGH CLOUDS MOVING ACROSS THIS AFTERNOON/EVENING...
ASSOCIATED WITH THE ALBERTA/SASKATCHEWAN SHORTWAVE PASSING TO OUR
NORTH. A WARM ADVECTION PATTERN WILL ENSUE THIS AFTERNOON AS THE
CURRENT HIGH PRESSURE RIDGE MOVES EAST INTO THE GREAT LAKES
REGION. 925MB TEMPS ARE PROGGED TO RANGE FROM -2C NORTH TO +2C
SOUTH AT 18Z TODAY...ABOUT 3 TO 5C COOLER THAN YESTERDAY. THUS...
HIGHS WILL BE A BIT COOLER DESPITE FULL SUNSHINE. THE WARM
ADVECTION SHOULD INCREASE TONIGHT AS LOW PRESSURE BEGINS TO FORM
NEAR RAPID CITY...ASSOCIATED WITH THE NEVADA SHORTWAVE LIFTING
INTO WESTERN SOUTH DAKOTA. THE INCREASING SOUTHERLY FLOW WILL HELP
KEEP TEMPERATURES UP...PARTICULARLY OVER THE HIGHER TERRAIN WEST
OF THE MISSISSIPPI RIVER. NOTE THAT THE TYPICAL COLD SPOTS OF
WISCONSIN COULD GET CHILLY...SINCE THE SOUTHERLY FLOW TAKES
LONGER TO RAMP UP THERE. GENERALLY FOLLOWED A BLEND OF GUIDANCE
WHICH HAS A GOOD HANDLE ON BOTH TEMPERATURE SITUATIONS.
SATURDAY AND SATURDAY NIGHT...MODELS ARE IN GOOD AGREEMENT IN
KEEPING THE AREA IN SOUTHWEST FLOW ALOFT...WITH THE CURRENT NEVADA
SHORTWAVE FOLLOWING THE FLOW AND LIFTING INTO CENTRAL MINNESOTA BY
12Z SUNDAY. SURFACE PRESSURE GRADIENT IS PROGGED TO BE FAIRLY TIGHT
THROUGHOUT THIS PERIOD...DUE TO THE DOWNSLOPING FLOW OFF THE ROCKIES
KEEPING PRESSURES LOW ON THE LEE SIDE WHILE THE CURRENT HIGH
PRESSURE AREA STRENGTHENS OVER THE EASTERN GREAT LAKES. THUS...
BREEZY CONDITIONS ARE ON TAP. FORECAST 925MB WINDS ARE 25-30KT ON
SATURDAY AND WITH WHAT LOOKS TO BE PLENTY OF SUN UNTIL SOME CIRRUS
LATE IN THE DAY...SOME MIXING DOWN OF THOSE HIGHER WINDS CAN BE
EXPECTED. GUSTS OF 20-25KT SEEMS LIKELY. REGARDING TEMPERATURES...
925MB READINGS ARE 4-6C AT 18Z...WHICH SHOULD PUT MOST LOCATIONS
INTO THE 50S. FOR SATURDAY NIGHT...THERE ARE INDICATIONS OF MID AND
HIGH CLOUDS INCREASING/THICKENING OVER THE FORECAST AREA AHEAD OF
THE SHORTWAVE LIFTING INTO CENTRAL MINNESOTA. IN ADDITION...
ISENTROPIC LIFT PLOTS ON THE 295-300K SURFACES SHOW WEAK LIFT FROM
650-780MB CENTERED MOSTLY WEST OF THE MISSISSIPPI RIVER AFTER 06Z.
HOWEVER...PLENTIFUL DRY AIR EXISTS BELOW 800MB TO PREVENT
PRECIPITATION...ESPECIALLY GIVEN ONLY WEAK LIFT EXPECTED. WITH THE
INCREASING CLOUDS AND A SOUTHERLY BREEZE...STAYED ON THE WARM SIDE
OF GUIDANCE FOR LOWS.
SUNDAY AND SUNDAY NIGHT...THE SHORTWAVE IN CENTRAL MINNESOTA AT 12Z
SUNDAY ALL MODELS HAVE LIFT TOWARDS THE THUNDER BAY ONTARIO AREA BY
00Z MONDAY...ALLOWING FOR A WEAK UPPER RIDGE TO BUILD INTO THE
FORECAST AREA BEHIND IT IN THE GENERAL SOUTHWEST FLOW. THIS WEAK
RIDGE MAY ALLOW FOR A LITTLE THINNING OF THE CLOUD COVER FROM
SATURDAY NIGHT...RESULTING IN A PARTLY SUNNY DAY. 925MB TEMPS ARE
PROGGED IN THE 4-7C RANGE...WHICH WOULD ALLOW LOCATIONS THAT HAVE
MORE SUN TO APPROACH 60F. HAVE KEPT HIGH TEMPERATURES IN THE 50S FOR
NOW DUE TO CLOUD COVER UNCERTAINTY. ANOTHER WEAK SHORTWAVE TROUGH IS
PROGGED TO COME UP THROUGH THE SOUTHWEST FLOW AND REACH WESTERN
PORTIONS OF IOWA AND MINNESOTA BY 12Z MONDAY. THIS TROUGH LOOKS TO
HAVE A BETTER TAP INTO GULF OF MEXICO MOISTURE...THUS AT A MINIMUM
AN EXTENSIVE STRATUS THROUGH MID AND HIGH CLOUD DECK IS LIKELY TO
ACCOMPANY IT. HOWEVER...ISENTROPIC LIFT FORCING IS WEAK AT BEST...
FOCUSED MAINLY AROUND 700MB ON THE 300K SURFACE AND BETWEEN 06-12Z
MONDAY. AS SUCH...MODEL QPF FIELDS ARE QUITE LIGHT AND EVEN THE
16.00Z NAM KEEPS THE PRECIPITATION EVEN WEST OF THE FORECAST AREA.
FOR NOW THERE REMAINS ENOUGH OF A SIGNAL TO MAINTAIN A 20 PERCENT
CHANCE WEST OF THE MISSISSIPPI RIVER. WITH A SOUTHERLY BREEZE
PERSISTING AND CLOUDS AROUND...ANOTHER MILD NIGHT FOR MID-NOVEMBER
IS ON TAP...AND AGAIN FOLLOWED A BLEND OF GUIDANCE FOR LOWS.
.LONG TERM...MONDAY THROUGH THANKSGIVING NIGHT
200 AM CST FRI NOV 16 2012
OVERALL...REALLY GOOD MODEL AGREEMENT EXISTS ON THE UPPER LEVEL AND
SURFACE PATTERNS AMONGST 16.00Z GUIDANCE THROUGH ABOUT WEDNESDAY.
THE PATTERN FEATURES THE PLAINS TROUGH SUNDAY NIGHT LIFTING UP INTO
NORTHERN ONTARIO ON TUESDAY...FOLLOWED BY RIDGING BUILDING INTO THE
FORECAST AREA FOR TUESDAY NIGHT INTO WEDNESDAY. 20-30 PERCENT
CHANCES OF RAIN ARE MAINTAINED FOR MONDAY...ASSOCIATED WITH THE WEAK
ISENTROPIC LIFT AND DPVA ASSOCIATED WITH THE PLAINS TROUGH. NOTE
THAT ANY PRECIPITATION LOOKS MINIMAL AT THIS TIME...THUS THE LOW
CHANCES. THERE MAY STILL BE SOME LINGERING PRECIPITATION IN THE FAR
EASTERN PORTIONS OF THE FORECAST AREA MONDAY NIGHT...THUS A 20
PERCENT CHANCE EXISTS THEN. DRY WEATHER FOLLOWS FOR TUESDAY INTO
WEDNESDAY WITH THE UPPER RIDGE BUILDING IN AND SURFACE RIDGE IN
PLACE. TEMPERATURES LOOK TO REMAIN ABOVE NORMAL...ESPECIALLY ON
WEDNESDAY AS A SURGE OF DOWNSLOPED AIR OFF THE ROCKIES FLOWS INTO
THE FORECAST AREA. THIS AIR IS CHARACTERIZED BY 850MB STANDARDIZED
ANOMALIES OF 1.5 ABOVE NORMAL. THUS...HAVE LEANED TOWARDS THE WARMER
ECMWF GUIDANCE FOR HIGHS...IN THE 55 TO 60 RANGE. THESE MAY NEED TO
BE INCREASED IN FUTURE RUNS.
FROM WEDNESDAY NIGHT THROUGH THANKSGIVING NIGHT...THERE IS A LITTLE
MORE DISAGREEMENT WITH WHAT HAPPENS IN THE UPPER LEVELS.
15.12Z/16.00Z ECMWF ALLOWS A SHORTWAVE COMING OUT OF A NORTHEAST
PACIFIC TROUGH AND TRACKS IT ALONG THE U.S./CANADIAN BORDER AND INTO
LAKE SUPERIOR THANKSGIVING NIGHT. THIS SITUATION ALLOWS FOR A COLD
FRONTAL PASSAGE ON THANKSGIVING...THOUGH THE TRUE COLDER AIR FILTERS
IN DURING THE NIGHT TIME. ON THE OTHER HAND...THE 16.00Z GFS/GFS
ENSEMBLES AND EXTRAPOLATION OF THE 16.00Z CANADIAN/UKMET PREFER TO
HOLD UPPER RIDGING IN PLACE OVER THE FORECAST AREA. WITH THIS
SCENARIO...THE WELL ABOVE NORMAL WARMTH SEEN ON WEDNESDAY WOULD
PERSIST THROUGH THANKSGIVING NIGHT BEFORE A COLD FRONT PASSES ON
FRIDAY. FOR NOW HAVE MAINTAINED A CONSENSUS SOLUTION GIVEN THE
DIFFERENCES. EITHER SOLUTION HAS LITTLE MOISTURE TO WORK WITH SO A
DRY FORECAST IS STILL ON TAP.
&&
.AVIATION...THROUGH 18Z SATURDAY
1125 AM CST FRI NOV 16 2012
SURFACE HIGH PRESSURE WILL DRIFT EASTWARD THIS AFTERNOON AND
TONIGHT RESULTING IN A TIGHTENING PRESSURE GRADIENT AT THE TAF
SITES. LOW LEVEL MOISTURE OFF LAKE MICHIGAN AS DEPICTED IN THE
0-1KM RELATIVE HUMIDITY PROGS FROM THE 16.12Z RAP REMAINS EAST OF
KLSE. THUS HAVE KEPT THE ENTIRE TAF PERIOD WITH CLEAR SKIES. WITH
THE GRADIENT INCREASING...SOUTHEAST WINDS 5 TO 10 KNOTS EXPECTED
TONIGHT AND THEN INCREASING AFTER 15Z SATURDAY...ESPECIALLY AT
KRST WHERE SOME GUSTS TO 22 KNOTS ARE LIKELY BEFORE 18Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
200 AM CST FRI NOV 16 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
544 AM CST FRI NOV 16 2012
.SHORT TERM...THROUGH SUNDAY NIGHT
200 AM CST FRI NOV 16 2012
MAIN FORECAST FOCUS IS ON CLOUD COVER AND TEMPERATURES WITH A QUIET
WEATHER PATTERN IN PLACE.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT
ANALYSIS SHOWED RIDGING FROM NEW MEXICO INTO THE DAKOTAS...A
SHORTWAVE OVER NEVADA...AND SHORTWAVE TROUGHS OVER FAR SOUTHERN
ALBERTA INTO SASKATCHEWAN...AS WELL AS OVER INDIANA. THE FORECAST
AREA LIES IN SUBSIDENCE AND DRYING BEHIND THE LATTER SHORTWAVE
TROUGH. 00Z MPX AND ABR SOUNDINGS WERE QUITE DRY WITH PRECIPITABLE
WATER VALUES AROUND 0.17 INCHES AND DEWPOINT DEPRESSIONS OF 10C OR
MORE THROUGHOUT. THE SUBSIDENCE WAS NOTED AT THE SURFACE BY HIGH
PRESSURE WHICH STRETCHES FROM KANSAS INTO NORTHERN ONTARIO. THE
CLEAR SKIES...LIGHT WINDS AND DRY AIR ASSOCIATED THEN WITH THIS
RIDGE HAS ALLOWED TEMPERATURES TO DROP INTO THE 20S AT MOST
LOCATIONS. TO THE WEST...LITTLE IS GOING ON WITH THE SOUTHERN
ALBERTA/SASKATCHEWAN SHORTWAVE TROUGH EXCEPT FOR SOME CIRRUS.
TODAY AND TONIGHT...THE UPPER RIDGING SEEN OVER THE DAKOTAS IS
FORECAST TO MOVE OVER THE AREA TODAY...THEN TO LAKE ERIE TONIGHT...
IN RESPONSE TO THE SOUTHERN ALBERTA/SASKATCHEWAN SHORTWAVE PUSHING
EAST. ALTHOUGH THIS SETUP PLACES THE FORECAST AREA UNDER SOUTHWEST
FLOW ALOFT...TYPICALLY GOOD FOR PRECIPITATION...THE EXTENSIVE
AMOUNT OF DRY AIR PRESENT WILL PREVENT ANY PRECIPITATION FROM
OCCURRING. IN FACT...WE MAY NOT SEE MUCH CLOUD COVER BESIDES SOME
SCATTERED HIGH CLOUDS MOVING ACROSS THIS AFTERNOON/EVENING...
ASSOCIATED WITH THE ALBERTA/SASKATCHEWAN SHORTWAVE PASSING TO OUR
NORTH. A WARM ADVECTION PATTERN WILL ENSUE THIS AFTERNOON AS THE
CURRENT HIGH PRESSURE RIDGE MOVES EAST INTO THE GREAT LAKES
REGION. 925MB TEMPS ARE PROGGED TO RANGE FROM -2C NORTH TO +2C
SOUTH AT 18Z TODAY...ABOUT 3 TO 5C COOLER THAN YESTERDAY. THUS...
HIGHS WILL BE A BIT COOLER DESPITE FULL SUNSHINE. THE WARM
ADVECTION SHOULD INCREASE TONIGHT AS LOW PRESSURE BEGINS TO FORM
NEAR RAPID CITY...ASSOCIATED WITH THE NEVADA SHORTWAVE LIFTING
INTO WESTERN SOUTH DAKOTA. THE INCREASING SOUTHERLY FLOW WILL HELP
KEEP TEMPERATURES UP...PARTICULARLY OVER THE HIGHER TERRAIN WEST
OF THE MISSISSIPPI RIVER. NOTE THAT THE TYPICAL COLD SPOTS OF
WISCONSIN COULD GET CHILLY...SINCE THE SOUTHERLY FLOW TAKES
LONGER TO RAMP UP THERE. GENERALLY FOLLOWED A BLEND OF GUIDANCE
WHICH HAS A GOOD HANDLE ON BOTH TEMPERATURE SITUATIONS.
SATURDAY AND SATURDAY NIGHT...MODELS ARE IN GOOD AGREEMENT IN
KEEPING THE AREA IN SOUTHWEST FLOW ALOFT...WITH THE CURRENT NEVADA
SHORTWAVE FOLLOWING THE FLOW AND LIFTING INTO CENTRAL MINNESOTA BY
12Z SUNDAY. SURFACE PRESSURE GRADIENT IS PROGGED TO BE FAIRLY TIGHT
THROUGHOUT THIS PERIOD...DUE TO THE DOWNSLOPING FLOW OFF THE ROCKIES
KEEPING PRESSURES LOW ON THE LEE SIDE WHILE THE CURRENT HIGH
PRESSURE AREA STRENGTHENS OVER THE EASTERN GREAT LAKES. THUS...
BREEZY CONDITIONS ARE ON TAP. FORECAST 925MB WINDS ARE 25-30KT ON
SATURDAY AND WITH WHAT LOOKS TO BE PLENTY OF SUN UNTIL SOME CIRRUS
LATE IN THE DAY...SOME MIXING DOWN OF THOSE HIGHER WINDS CAN BE
EXPECTED. GUSTS OF 20-25KT SEEMS LIKELY. REGARDING TEMPERATURES...
925MB READINGS ARE 4-6C AT 18Z...WHICH SHOULD PUT MOST LOCATIONS
INTO THE 50S. FOR SATURDAY NIGHT...THERE ARE INDICATIONS OF MID AND
HIGH CLOUDS INCREASING/THICKENING OVER THE FORECAST AREA AHEAD OF
THE SHORTWAVE LIFTING INTO CENTRAL MINNESOTA. IN ADDITION...
ISENTROPIC LIFT PLOTS ON THE 295-300K SURFACES SHOW WEAK LIFT FROM
650-780MB CENTERED MOSTLY WEST OF THE MISSISSIPPI RIVER AFTER 06Z.
HOWEVER...PLENTIFUL DRY AIR EXISTS BELOW 800MB TO PREVENT
PRECIPITATION...ESPECIALLY GIVEN ONLY WEAK LIFT EXPECTED. WITH THE
INCREASING CLOUDS AND A SOUTHERLY BREEZE...STAYED ON THE WARM SIDE
OF GUIDANCE FOR LOWS.
SUNDAY AND SUNDAY NIGHT...THE SHORTWAVE IN CENTRAL MINNESOTA AT 12Z
SUNDAY ALL MODELS HAVE LIFT TOWARDS THE THUNDER BAY ONTARIO AREA BY
00Z MONDAY...ALLOWING FOR A WEAK UPPER RIDGE TO BUILD INTO THE
FORECAST AREA BEHIND IT IN THE GENERAL SOUTHWEST FLOW. THIS WEAK
RIDGE MAY ALLOW FOR A LITTLE THINNING OF THE CLOUD COVER FROM
SATURDAY NIGHT...RESULTING IN A PARTLY SUNNY DAY. 925MB TEMPS ARE
PROGGED IN THE 4-7C RANGE...WHICH WOULD ALLOW LOCATIONS THAT HAVE
MORE SUN TO APPROACH 60F. HAVE KEPT HIGH TEMPERATURES IN THE 50S FOR
NOW DUE TO CLOUD COVER UNCERTAINTY. ANOTHER WEAK SHORTWAVE TROUGH IS
PROGGED TO COME UP THROUGH THE SOUTHWEST FLOW AND REACH WESTERN
PORTIONS OF IOWA AND MINNESOTA BY 12Z MONDAY. THIS TROUGH LOOKS TO
HAVE A BETTER TAP INTO GULF OF MEXICO MOISTURE...THUS AT A MINIMUM
AN EXTENSIVE STRATUS THROUGH MID AND HIGH CLOUD DECK IS LIKELY TO
ACCOMPANY IT. HOWEVER...ISENTROPIC LIFT FORCING IS WEAK AT BEST...
FOCUSED MAINLY AROUND 700MB ON THE 300K SURFACE AND BETWEEN 06-12Z
MONDAY. AS SUCH...MODEL QPF FIELDS ARE QUITE LIGHT AND EVEN THE
16.00Z NAM KEEPS THE PRECIPITATION EVEN WEST OF THE FORECAST AREA.
FOR NOW THERE REMAINS ENOUGH OF A SIGNAL TO MAINTAIN A 20 PERCENT
CHANCE WEST OF THE MISSISSIPPI RIVER. WITH A SOUTHERLY BREEZE
PERSISTING AND CLOUDS AROUND...ANOTHER MILD NIGHT FOR MID-NOVEMBER
IS ON TAP...AND AGAIN FOLLOWED A BLEND OF GUIDANCE FOR LOWS.
.LONG TERM...MONDAY THROUGH THANKSGIVING NIGHT
200 AM CST FRI NOV 16 2012
OVERALL...REALLY GOOD MODEL AGREEMENT EXISTS ON THE UPPER LEVEL AND
SURFACE PATTERNS AMONGST 16.00Z GUIDANCE THROUGH ABOUT WEDNESDAY.
THE PATTERN FEATURES THE PLAINS TROUGH SUNDAY NIGHT LIFTING UP INTO
NORTHERN ONTARIO ON TUESDAY...FOLLOWED BY RIDGING BUILDING INTO THE
FORECAST AREA FOR TUESDAY NIGHT INTO WEDNESDAY. 20-30 PERCENT
CHANCES OF RAIN ARE MAINTAINED FOR MONDAY...ASSOCIATED WITH THE WEAK
ISENTROPIC LIFT AND DPVA ASSOCIATED WITH THE PLAINS TROUGH. NOTE
THAT ANY PRECIPITATION LOOKS MINIMAL AT THIS TIME...THUS THE LOW
CHANCES. THERE MAY STILL BE SOME LINGERING PRECIPITATION IN THE FAR
EASTERN PORTIONS OF THE FORECAST AREA MONDAY NIGHT...THUS A 20
PERCENT CHANCE EXISTS THEN. DRY WEATHER FOLLOWS FOR TUESDAY INTO
WEDNESDAY WITH THE UPPER RIDGE BUILDING IN AND SURFACE RIDGE IN
PLACE. TEMPERATURES LOOK TO REMAIN ABOVE NORMAL...ESPECIALLY ON
WEDNESDAY AS A SURGE OF DOWNSLOPED AIR OFF THE ROCKIES FLOWS INTO
THE FORECAST AREA. THIS AIR IS CHARACTERIZED BY 850MB STANDARDIZED
ANOMALIES OF 1.5 ABOVE NORMAL. THUS...HAVE LEANED TOWARDS THE WARMER
ECMWF GUIDANCE FOR HIGHS...IN THE 55 TO 60 RANGE. THESE MAY NEED TO
BE INCREASED IN FUTURE RUNS.
FROM WEDNESDAY NIGHT THROUGH THANKSGIVING NIGHT...THERE IS A LITTLE
MORE DISAGREEMENT WITH WHAT HAPPENS IN THE UPPER LEVELS.
15.12Z/16.00Z ECMWF ALLOWS A SHORTWAVE COMING OUT OF A NORTHEAST
PACIFIC TROUGH AND TRACKS IT ALONG THE U.S./CANADIAN BORDER AND INTO
LAKE SUPERIOR THANKSGIVING NIGHT. THIS SITUATION ALLOWS FOR A COLD
FRONTAL PASSAGE ON THANKSGIVING...THOUGH THE TRUE COLDER AIR FILTERS
IN DURING THE NIGHT TIME. ON THE OTHER HAND...THE 16.00Z GFS/GFS
ENSEMBLES AND EXTRAPOLATION OF THE 16.00Z CANADIAN/UKMET PREFER TO
HOLD UPPER RIDGING IN PLACE OVER THE FORECAST AREA. WITH THIS
SCENARIO...THE WELL ABOVE NORMAL WARMTH SEEN ON WEDNESDAY WOULD
PERSIST THROUGH THANKSGIVING NIGHT BEFORE A COLD FRONT PASSES ON
FRIDAY. FOR NOW HAVE MAINTAINED A CONSENSUS SOLUTION GIVEN THE
DIFFERENCES. EITHER SOLUTION HAS LITTLE MOISTURE TO WORK WITH SO A
DRY FORECAST IS STILL ON TAP.
&&
.AVIATION...TODAY AND TONIGHT
528 AM CST FRI NOV 16 2012
HIGH PRESSURE CENTERED OVER EAST-CENTRAL MINNESOTA WILL MOVE
EAST FROM NORTHERN WISCONSIN TO EASTERN QUEBEC TODAY. AS THIS
OCCURS...THE WINDS WILL SHIFT FROM THE NORTH TO THE EAST BY MID
MORNING AND SOUTH BY EARLY AFTERNOON. WIND SPEEDS WILL REMAIN LESS
THAN 10 KNOTS.
THE 16.00Z TRIES TO BRING SOME 925 MB MOISTURE INTO KLSE AROUND
16.12Z. THIS MOISTURE IS SUPPOSED TO BE ALREADY ACROSS SOUTHERN
WISCONSIN AND BOTH THE SATELLITE AND OBSERVATIONS DO NOT SUPPORT
THIS. AS A RESULT...TRENDED THE FORECAST TOWARD THE NAM/WRF WHICH
KEEPS CLEAR SKIES AT BOTH TAF SITES THROUGH 17.12Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
200 AM CST FRI NOV 16 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
200 AM CST FRI NOV 16 2012
.SHORT TERM...THROUGH SUNDAY NIGHT
200 AM CST FRI NOV 16 2012
MAIN FORECAST FOCUS IS ON CLOUD COVER AND TEMPERATURES WITH A QUIET
WEATHER PATTERN IN PLACE.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT
ANALYSIS SHOWED RIDGING FROM NEW MEXICO INTO THE DAKOTAS...A
SHORTWAVE OVER NEVADA...AND SHORTWAVE TROUGHS OVER FAR SOUTHERN
ALBERTA INTO SASKATCHEWAN...AS WELL AS OVER INDIANA. THE FORECAST
AREA LIES IN SUBSIDENCE AND DRYING BEHIND THE LATTER SHORTWAVE
TROUGH. 00Z MPX AND ABR SOUNDINGS WERE QUITE DRY WITH PRECIPITABLE
WATER VALUES AROUND 0.17 INCHES AND DEWPOINT DEPRESSIONS OF 10C OR
MORE THROUGHOUT. THE SUBSIDENCE WAS NOTED AT THE SURFACE BY HIGH
PRESSURE WHICH STRETCHES FROM KANSAS INTO NORTHERN ONTARIO. THE
CLEAR SKIES...LIGHT WINDS AND DRY AIR ASSOCIATED THEN WITH THIS
RIDGE HAS ALLOWED TEMPERATURES TO DROP INTO THE 20S AT MOST
LOCATIONS. TO THE WEST...LITTLE IS GOING ON WITH THE SOUTHERN
ALBERTA/SASKATCHEWAN SHORTWAVE TROUGH EXCEPT FOR SOME CIRRUS.
TODAY AND TONIGHT...THE UPPER RIDGING SEEN OVER THE DAKOTAS IS
FORECAST TO MOVE OVER THE AREA TODAY...THEN TO LAKE ERIE TONIGHT...
IN RESPONSE TO THE SOUTHERN ALBERTA/SASKATCHEWAN SHORTWAVE PUSHING
EAST. ALTHOUGH THIS SETUP PLACES THE FORECAST AREA UNDER SOUTHWEST
FLOW ALOFT...TYPICALLY GOOD FOR PRECIPITATION...THE EXTENSIVE
AMOUNT OF DRY AIR PRESENT WILL PREVENT ANY PRECIPITATION FROM
OCCURRING. IN FACT...WE MAY NOT SEE MUCH CLOUD COVER BESIDES SOME
SCATTERED HIGH CLOUDS MOVING ACROSS THIS AFTERNOON/EVENING...
ASSOCIATED WITH THE ALBERTA/SASKATCHEWAN SHORTWAVE PASSING TO OUR
NORTH. A WARM ADVECTION PATTERN WILL ENSUE THIS AFTERNOON AS THE
CURRENT HIGH PRESSURE RIDGE MOVES EAST INTO THE GREAT LAKES
REGION. 925MB TEMPS ARE PROGGED TO RANGE FROM -2C NORTH TO +2C
SOUTH AT 18Z TODAY...ABOUT 3 TO 5C COOLER THAN YESTERDAY. THUS...
HIGHS WILL BE A BIT COOLER DESPITE FULL SUNSHINE. THE WARM
ADVECTION SHOULD INCREASE TONIGHT AS LOW PRESSURE BEGINS TO FORM
NEAR RAPID CITY...ASSOCIATED WITH THE NEVADA SHORTWAVE LIFTING
INTO WESTERN SOUTH DAKOTA. THE INCREASING SOUTHERLY FLOW WILL HELP
KEEP TEMPERATURES UP...PARTICULARLY OVER THE HIGHER TERRAIN WEST
OF THE MISSISSIPPI RIVER. NOTE THAT THE TYPICAL COLD SPOTS OF
WISCONSIN COULD GET CHILLY...SINCE THE SOUTHERLY FLOW TAKES
LONGER TO RAMP UP THERE. GENERALLY FOLLOWED A BLEND OF GUIDANCE
WHICH HAS A GOOD HANDLE ON BOTH TEMPERATURE SITUATIONS.
SATURDAY AND SATURDAY NIGHT...MODELS ARE IN GOOD AGREEMENT IN
KEEPING THE AREA IN SOUTHWEST FLOW ALOFT...WITH THE CURRENT NEVADA
SHORTWAVE FOLLOWING THE FLOW AND LIFTING INTO CENTRAL MINNESOTA BY
12Z SUNDAY. SURFACE PRESSURE GRADIENT IS PROGGED TO BE FAIRLY TIGHT
THROUGHOUT THIS PERIOD...DUE TO THE DOWNSLOPING FLOW OFF THE ROCKIES
KEEPING PRESSURES LOW ON THE LEE SIDE WHILE THE CURRENT HIGH
PRESSURE AREA STRENGTHENS OVER THE EASTERN GREAT LAKES. THUS...
BREEZY CONDITIONS ARE ON TAP. FORECAST 925MB WINDS ARE 25-30KT ON
SATURDAY AND WITH WHAT LOOKS TO BE PLENTY OF SUN UNTIL SOME CIRRUS
LATE IN THE DAY...SOME MIXING DOWN OF THOSE HIGHER WINDS CAN BE
EXPECTED. GUSTS OF 20-25KT SEEMS LIKELY. REGARDING TEMPERATURES...
925MB READINGS ARE 4-6C AT 18Z...WHICH SHOULD PUT MOST LOCATIONS
INTO THE 50S. FOR SATURDAY NIGHT...THERE ARE INDICATIONS OF MID AND
HIGH CLOUDS INCREASING/THICKENING OVER THE FORECAST AREA AHEAD OF
THE SHORTWAVE LIFTING INTO CENTRAL MINNESOTA. IN ADDITION...
ISENTROPIC LIFT PLOTS ON THE 295-300K SURFACES SHOW WEAK LIFT FROM
650-780MB CENTERED MOSTLY WEST OF THE MISSISSIPPI RIVER AFTER 06Z.
HOWEVER...PLENTIFUL DRY AIR EXISTS BELOW 800MB TO PREVENT
PRECIPITATION...ESPECIALLY GIVEN ONLY WEAK LIFT EXPECTED. WITH THE
INCREASING CLOUDS AND A SOUTHERLY BREEZE...STAYED ON THE WARM SIDE
OF GUIDANCE FOR LOWS.
SUNDAY AND SUNDAY NIGHT...THE SHORTWAVE IN CENTRAL MINNESOTA AT 12Z
SUNDAY ALL MODELS HAVE LIFT TOWARDS THE THUNDER BAY ONTARIO AREA BY
00Z MONDAY...ALLOWING FOR A WEAK UPPER RIDGE TO BUILD INTO THE
FORECAST AREA BEHIND IT IN THE GENERAL SOUTHWEST FLOW. THIS WEAK
RIDGE MAY ALLOW FOR A LITTLE THINNING OF THE CLOUD COVER FROM
SATURDAY NIGHT...RESULTING IN A PARTLY SUNNY DAY. 925MB TEMPS ARE
PROGGED IN THE 4-7C RANGE...WHICH WOULD ALLOW LOCATIONS THAT HAVE
MORE SUN TO APPROACH 60F. HAVE KEPT HIGH TEMPERATURES IN THE 50S FOR
NOW DUE TO CLOUD COVER UNCERTAINTY. ANOTHER WEAK SHORTWAVE TROUGH IS
PROGGED TO COME UP THROUGH THE SOUTHWEST FLOW AND REACH WESTERN
PORTIONS OF IOWA AND MINNESOTA BY 12Z MONDAY. THIS TROUGH LOOKS TO
HAVE A BETTER TAP INTO GULF OF MEXICO MOISTURE...THUS AT A MINIMUM
AN EXTENSIVE STRATUS THROUGH MID AND HIGH CLOUD DECK IS LIKELY TO
ACCOMPANY IT. HOWEVER...ISENTROPIC LIFT FORCING IS WEAK AT BEST...
FOCUSED MAINLY AROUND 700MB ON THE 300K SURFACE AND BETWEEN 06-12Z
MONDAY. AS SUCH...MODEL QPF FIELDS ARE QUITE LIGHT AND EVEN THE
16.00Z NAM KEEPS THE PRECIPITATION EVEN WEST OF THE FORECAST AREA.
FOR NOW THERE REMAINS ENOUGH OF A SIGNAL TO MAINTAIN A 20 PERCENT
CHANCE WEST OF THE MISSISSIPPI RIVER. WITH A SOUTHERLY BREEZE
PERSISTING AND CLOUDS AROUND...ANOTHER MILD NIGHT FOR MID-NOVEMBER
IS ON TAP...AND AGAIN FOLLOWED A BLEND OF GUIDANCE FOR LOWS.
.LONG TERM...MONDAY THROUGH THANKSGIVING NIGHT
200 AM CST FRI NOV 16 2012
OVERALL...REALLY GOOD MODEL AGREEMENT EXISTS ON THE UPPER LEVEL AND
SURFACE PATTERNS AMONGST 16.00Z GUIDANCE THROUGH ABOUT WEDNESDAY.
THE PATTERN FEATURES THE PLAINS TROUGH SUNDAY NIGHT LIFTING UP INTO
NORTHERN ONTARIO ON TUESDAY...FOLLOWED BY RIDGING BUILDING INTO THE
FORECAST AREA FOR TUESDAY NIGHT INTO WEDNESDAY. 20-30 PERCENT
CHANCES OF RAIN ARE MAINTAINED FOR MONDAY...ASSOCIATED WITH THE WEAK
ISENTROPIC LIFT AND DPVA ASSOCIATED WITH THE PLAINS TROUGH. NOTE
THAT ANY PRECIPITATION LOOKS MINIMAL AT THIS TIME...THUS THE LOW
CHANCES. THERE MAY STILL BE SOME LINGERING PRECIPITATION IN THE FAR
EASTERN PORTIONS OF THE FORECAST AREA MONDAY NIGHT...THUS A 20
PERCENT CHANCE EXISTS THEN. DRY WEATHER FOLLOWS FOR TUESDAY INTO
WEDNESDAY WITH THE UPPER RIDGE BUILDING IN AND SURFACE RIDGE IN
PLACE. TEMPERATURES LOOK TO REMAIN ABOVE NORMAL...ESPECIALLY ON
WEDNESDAY AS A SURGE OF DOWNSLOPED AIR OFF THE ROCKIES FLOWS INTO
THE FORECAST AREA. THIS AIR IS CHARACTERIZED BY 850MB STANDARDIZED
ANOMALIES OF 1.5 ABOVE NORMAL. THUS...HAVE LEANED TOWARDS THE WARMER
ECMWF GUIDANCE FOR HIGHS...IN THE 55 TO 60 RANGE. THESE MAY NEED TO
BE INCREASED IN FUTURE RUNS.
FROM WEDNESDAY NIGHT THROUGH THANKSGIVING NIGHT...THERE IS A LITTLE
MORE DISAGREEMENT WITH WHAT HAPPENS IN THE UPPER LEVELS.
15.12Z/16.00Z ECMWF ALLOWS A SHORTWAVE COMING OUT OF A NORTHEAST
PACIFIC TROUGH AND TRACKS IT ALONG THE U.S./CANADIAN BORDER AND INTO
LAKE SUPERIOR THANKSGIVING NIGHT. THIS SITUATION ALLOWS FOR A COLD
FRONTAL PASSAGE ON THANKSGIVING...THOUGH THE TRUE COLDER AIR FILTERS
IN DURING THE NIGHT TIME. ON THE OTHER HAND...THE 16.00Z GFS/GFS
ENSEMBLES AND EXTRAPOLATION OF THE 16.00Z CANADIAN/UKMET PREFER TO
HOLD UPPER RIDGING IN PLACE OVER THE FORECAST AREA. WITH THIS
SCENARIO...THE WELL ABOVE NORMAL WARMTH SEEN ON WEDNESDAY WOULD
PERSIST THROUGH THANKSGIVING NIGHT BEFORE A COLD FRONT PASSES ON
FRIDAY. FOR NOW HAVE MAINTAINED A CONSENSUS SOLUTION GIVEN THE
DIFFERENCES. EITHER SOLUTION HAS LITTLE MOISTURE TO WORK WITH SO A
DRY FORECAST IS STILL ON TAP.
&&
.AVIATION...THROUGH 06Z SATURDAY
1059 PM CST THU NOV 15 2012
VFR CONDITIONS WITH CLEAR SKIES EXPECTED THROUGH THE TAF PERIOD.
SURFACE HIGH PRESSURE WILL DRIFT ACROSS THE TAF SITES TONIGHT AND
INTO EASTERN WISCONSIN/LAKE MICHIGAN BY LATE FRIDAY EVENING. LIGHT
NORTHERLY WINDS WILL COME AROUND TO THE EAST AND THEN FINALLY THE
SOUTHEAST BY FRIDAY AFTERNOON...BUT REMAIN BELOW 12 KNOTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
200 AM CST FRI NOV 16 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...RABERDING
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
1237 AM EST SUN NOV 18 2012
.AVIATION...
THE ISOLATED SHOWERS WILL CONTINUE TO AFFECT THE KPBI TAF SITE
THROUGH TODAY...DUE TO THE FRONTAL BOUNDARY REMAINING NEARLY
STATIONARY OVER THIS AREA. REST OF THE TAF SITES ACROSS SOUTH
FLORIDA SHOULD REMAIN DRY TODAY. SO WILL KEEP A VCSH IN THE TAF
SITE FOR KPBI.
THE WINDS WILL ALSO BE LIGHT AND VARIABLE ACROSS THE EAST COAST
TAF SITES EARLY THIS MORNING...BEFORE SWINGING TO A 10 TO 30
DEGREE DIRECTION WITH SPEEDS AROUND 10 MPH THROUGH 00Z MONDAY. AT
KAPF TAF SITE...THE WIND SPEEDS WILL BE AROUND 10 MPH TODAY FROM
THE NORTH TO NORTHEAST DIRECTION. THE CEILING AND VIS WILL ALSO
REMAIN IN THE VFR CONDITIONS TODAY AT ALL OF THE TAF SITES.
&&
.AVIATION...54/BNB
.PREV DISCUSSION... /ISSUED 1015 PM EST SAT NOV 17 2012/
UPDATE...
NO MAJOR UPDATES TO THE PREVIOUS FORECAST ARE EXPECTED THIS
EVENING. THE EVENING SURFACE ANALYSIS SHOWED A LINGERING WEAK
TROUGH OR WHAT IS LEFT OF AN OLD FRONTAL BOUNDARY JUST EAST OF THE
FLORIDA PENINSULA WITH LIGHT TO MODERATE NORTHEAST FLOW
CONTINUING. ENHANCED LOW-LEVEL CONVERGENCE NEAR AND AROUND THIS
SURFACE FEATURE COMBINED WITH BELOW AVERAGE MID/UPPER-LEVEL
TEMPERATURES WILL MAINTAIN THE CHANCE FOR MAINLY ISOLATED SHOWERS
OVER THE ADJACENT ATLANTIC WATERS AND COASTAL AREAS THROUGH THE
OVERNIGHT HOURS. SIMILAR TO THE PAST FEW NIGHTS...INLAND FOG WILL
BE POSSIBLE THROUGH THE OVERNIGHT HOURS ACROSS THE INTERIOR AREAS.
THE LATEST SREF MODEL PROBABILITIES SUPPORT THIS AND INDICATE A
GOOD PORTION OF THIS INTERIOR AREA AROUND AND SOUTH OF THE LAKE
DIPPING INTO THE 1-3 MILE VISIBILITY RANGE BY DAYBREAK SUNDAY.
85/AG
&&
PREV DISCUSSION... /ISSUED 644 PM EST SAT NOV 17 2012/
AVIATION...
AS A STALLED FRONTAL BOUNDARY LINGERS JUST OFFSHORE THE ATLANTIC
COAST...ISOLATED SHOWERS WILL REMAIN ACROSS THE AREA THROUGH THE
NIGHT AND IS DEPICTED BY THE LATEST HRRR GUIDANCE. SHOWERS COULD
BRIEFLY AFFECT ONE OR MORE EAST COAST SITES THROUGH THE EVENING
WITH MVFR CONDITIONS BUT WOULD BE VERY BRIEF AND DECIDED NOT TO
PREVAIL ANY SHRA MENTION. MID LEVEL DRYING EXPECTED TO PUSH INTO
THE SOUTH FLORIDA PENINSULA FROM THE NORTH THROUGH THE LATTER HALF
OF THE PERIOD.
&&
PREV DISCUSSION... /ISSUED 246 PM EST SAT NOV 17 2012/
DISCUSSION...
SHORT TERM...THE BASIC SYNOPTIC SETUP OVER THE AREA IS A
NORTHWESTERLY FLOW OVER THE CWA AS HIGH PRESSURE TO THE NORTH
SLOWLY PUSHES A LOW PRESSURE SYSTEM WELL TO THE SOUTHEAST
EASTWARD. THERE IS A STALLED BOUNDARY THAT CONTINUES TO LAY
ACROSS THE OFFSHORE WATERS IN THE ATLANTIC. THE HIGH, CENTERED
OVER NEW ENGLAND, IS VERY SLOWLY CAUSING THE BOUNDARY TO DRIFT TO
THE EAST AND HAS PUSHED MOST OF THE SHOWERS AWAY FROM THE CWA.
THIS BOUNDARY WILL NOT GO FAR, HOWEVER, AS THERE IS NO REAL PUSH
NORMAL TO THE BOUNDARY. RATHER, THE FLOW IS ALMOST PARALLEL TO THE
BOUNDARY. SO, WITH STILL PLENTY OF MOISTURE REMAINING OVER THE
MAINLAND, DAYTIME HEATING WILL CAUSE SOME ISOLATED SHOWERS TO
DEVELOP. MODELS ARE INDICATING MOST OF ANY CONVECTION WILL BE
LOCATED MAINLY OFF SHORE. THIS PATTERN WILL BE IN PLACE FOR THE
REMAINDER OF THE WEEKEND.
OVER THE NEXT COUPLE OF DAYS, THE LOW WILL SLOWLY MOVE TO THE
NORTH AS THE HIGH PRESSURE SLIDES WELL TO THE NORTHEAST. THE LOW
WILL THEN DEEPEN AND INTERACT WITH THE STALLED BOUNDARY, TURNING
IT INTO A COLD FRONT. THIS COULD ALLOW FOR SOME SHOWERS OVER THE
ATLANTIC TO DEVELOP, BUT STILL LOOK ISOLATED AT BEST THROUGH 12Z
TUESDAY.
ALSO, WITH THE LOW DEVELOPING NEXT WEEK, SOMEWHAT COOLER, DRIER
AIR WILL TRY TO MAKE ITS WAY DOWN THE FLORIDA PENINSULA. WHILE
THE TEMPERATURES WILL ONLY COOL A COUPLE OF DEGREES, THE DEW
POINTS SHOULD DROP AROUND 5 DEGREES, ALLOWING THE AIR TO FEEL
SOMEWHAT DRIER FOR THE BEGINNING OF THE WEEK.
LONG TERM...TUESDAY THROUGH FRIDAY...DRY AND STABLE AIR OVER S FLA
TUESDAY PRECLUDES PRECIPITATION EXCEPT FOR THE E COAST. BY WEDNESDAY
THE APPROACHING UPPER TROUGH SHOVES A COLD FRONT TOWARD S FLA
THAT MOVES THROUGH THE AREA WEDNESDAY WITH SOME SHOWER ACTIVITY.
THURSDAY AND FRIDAY WILL BE DRY BUT COOLER. LOWS THURSDAY WILL RANGE
FROM NEAR 50 W OF LAKE OKEECHOBEE TO THE LOWER 60S SE WITH SLIGHTLY
WARMER TEMPERATURES FRIDAY MORNING. HIGHS WILL BE IN THE 70S
THURSDAY AND FRIDAY.
MARINE...
NNE TO NE WINDS AT 10 TO 15 KTS THROUGH MONDAY THEN SHIFTING MORE
NORTHERLY AND SLIGHTLY DECREASING TUESDAY BEFORE INCREASING FROM THE
NW WEDNESDAY BEHIND THE FRONT WITH MARINE CONDITIONS DETERIORATING.
SOME RISK OF RIP CURRENTS POSSIBLE E COAST TODAY...SUNDAY AND
MONDAY. WATERSPOUTS POSSIBLE ATLC WATERS TODAY AS OFFSHORE FLOW
CONVERGING WITH THE EASTERLY ATLC FLOW OFFSHORE.
FIRE WEATHER...
NO FIRE WEATHER CONCERNS ARE CURRENTLY ANTICIPATED. LOW PRESSURE
TO THE SOUTH, WILL SLOWLY MOVE TO THE NORTH, WELL EAST OF THE
BAHAMAS. THIS WILL ALLOW SLIGHTLY DRIER AIR TO MOVE IN NEXT WEEK,
WITH SLIGHTLY COOLER TEMPERATURES AS WELL. WINDS, OVER THE NEXT FEW
DAYS, WILL CONTINUE TO BE OUT OF THE NORTH NORTHEAST BETWEEN 5 AND
10 KTS. THEY WILL BECOME MORE NORTH TO NORTHWESTERLY BY MONDAY,
STILL BETWEEN 5 AND 10KTS. AS FOR MINIMUM RH, EXPECT RH`S IN THE
MID 50 PERCENT RANGE FOR THE WEEKEND, DROPPING INTO THE MID 40 TO
LOW 50 PERCENT RANGE BEGINNING NEXT WEEK. RECOVERIES SHOULD
CONTINUE TO BE GOOD EVERY NIGHT, REACHING INTO THE 90 PERCENT
RANGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 63 79 64 79 / 10 - - 10
FORT LAUDERDALE 65 79 65 80 / 10 10 - 10
MIAMI 65 79 65 79 / 10 - - 10
NAPLES 61 75 62 78 / 10 - - -
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...15/JR
AVIATION/RADAR...54/BNB
AREA FORECAST DISCUSSION
NWS LINCOLN IL
307 AM CST SUN NOV 18 2012
.DISCUSSION...
ISSUED 250 AM CST SUN NOV 18 2012
CURRENT WEATHER PATTERN NOT MUCH DIFFERENT THAN 24 HRS AGO...WITH
AN UPPER LOW OVER THE EXTREME SERN US...AND HIGH PRESSURE RIDGE
FROM SERN CANADA TO THE CENTRAL GULF COAST. SFC WINDS IN THE
OVERNIGHT LIGHTER...BUT PREDOMINANTLY OUT OF THE S/SE AS THE SUN
COMES UP. FORECAST IS ESSENTIALLY ONE OF TEMPERATURES. TWO WAVES
ARE PROGGED TO MOVE THROUGH THE QUASI ZONAL FLOW...MON/MON
NIGHT...AND AGAIN LATER IN THE WEEK...BUT THE MODELS ARE SKETCHY
WITH CONSISTENCY...AND THE ATMOSPHERE WILL BE STRUGGLING TO
PRODUCE MOISTURE. AS A RESULT...THE ZONE FORECAST IS RUNNING DRY
AT THE MOMENT. TEMPERATURES RUNNING ABOVE NORMAL THROUGH MIDWEEK.
SHORT TERM...TODAY AND TOMORROW...
RATHER QUIET WEATHER AND S/SERLY WINDS AT THE SFC WITH HIGH PRESSURE
RIDGE OVER THE EASTERN HALF OF THE COUNTRY. MILD TEMPS
CONTINUE...APPROACHING LOW 60S FOR MUCH OF THE AREA. MOSTLY SUNNY
SKIES...AND CLEAR OVERNIGHT WILL COUNTER THE SOUTHERLY FLOW WITH RATHER
EFFECTIVE RADIATIONAL COOLING AND TEMPS DROPPING INTO THE UPPER
30S AND NEAR 40. SOUTHERLY WINDS PICK UP A BIT ON MONDAY...AND A
BROAD AREA OF WAA PUSHES UNSEASONABLE HEAT INTO THE SW AND CENTRAL
PORTIONS OF THE COUNTRY. TEMPS MONDAY A BIT AHEAD OF GUIDANCE...AS
THE SLOW WARMING TREND CONTINUES ACROSS THE MIDWEST.
LONG TERM...TUESDAY THROUGH SATURDAY...
HIGH PRESSURE RIDGE SLOWLY DRIFTS EASTWARD AND THE CLOSED UPPER
LOW KICKS OUT OF THE SE. A SHORT WAVE RIPPLES THROUGH THE UPPER
ATMOSPHERE...BRINGING A CHANCE FOR SHOWERS MON/MON NIGHT. AND
THOUGH THE GFS AND THE NAM ARE BOTH PORTRAYING SOME QPF FOR THE
REGION...KEEPING THE POPS RELATIVELY LOW...IN THE SLIGHT CHANCE
CAT...AND LACK OF COVERAGE POTENTIAL IF NOTHING ELSE. MOISTURE IS
SOMEWHAT LACKING THROUGH THE LAYER AHEAD OF THE SYSTEM. SOUTHERLY
WINDS PRIOR TO MONDAY NOT PROVIDING MUCH MOISTURE TRANSPORT INTO
THE AREA. WINDS START TO PICK UP A BIT ON MON WITH AN APPROACHING
STORM SYSTEM...BUT STILL NOT MUCH IN EXCESS OF 10 KTS. MODELS
HAVING A BIT OF AN ISSUE WITH THE WAVE ITSELF...WITH THE ECMWF
HOLDING BACK A BIT AND PASSING A MORE VIGOROUS PIECE OF ENERGY
LATER ON TUESDAY...ALBEIT A BIT OF AN OUTLIER. WILL WATCH
CAREFULLY.
ON THE OTHER SIDE OF THE CHANCES FOR SHOWERS MON...THE
WARMING TREND CONTINUES THROUGH MID WEEK. 850MB TEMPS AT 6-7C WILL
HAVE THE POTENTIAL TO TRANSLATE INTO UPPER 50S/LOWER 60S. GUIDANCE
HAS NOT COMPLETELY LATCHED ONTO THE WARMING TREND...THOUGH THE
MODEL FIELDS CLEARLY SHOW THE THERMAL RIDGE IN THE WESTERN CONUS
DEEPENING AND SLOWLY CREEPING INTO THE MIDWEST. HAVE BUMPED MAX
TEMPS A FEW DEGREES AHEAD OF ALLBLEND FOR MON- WED...AND A BIT ON
THURSDAY. THURSDAY MAY BE COMPLICATED BY AN APPROACHING STORM
SYSTEM AND ASSOCIATED CLOUD COVER...BUT SYSTEM STILL HAS A BIT OF
UNCERTAINTY AND WOULD ALSO HAVE THE SAME PROBLEM AS MONDAYS WAVE WITH
SCANT MOISTURE. KEEPING THE POPS LOW AND THE TEMPS A COUPLE OF
DEGREES ABOVE GUIDANCE...BUT MODERATE FOR NOW.
HJS
&&
.AVIATION...
ISSUED 1137 PM CST SAT NOV 17 2012...FOR THE 06Z TAFS
FORECAST RAP SOUNDINGS ARE STILL INDICATING MVFR VIS OF 4-5SM BR
WILL BE POSSIBLE LATER TONIGHT. BASED ON A SIMILAR AIRMASS TO LAST
NIGHT...WE KEPT A MENTION OF MVFR FOG AT ALL BUT BMI FOR SEVERAL
HOURS FROM 10/11Z TO 15/16Z. CIRRUS CLOUDS HAVE MAINLY CLEARED OUT
TO THE EAST...SO RADIATIONAL COOLING CONDITIONS WILL SUPPORT OUR
AIR TEMPS DIPPING TO NEAR THE WET BULB LATER TONIGHT.
LIGHT SOUTHEAST OR CALM WINDS WILL PREVAIL DUE TO THE WEAK
PRESSURE GRADIENT AND THE PROXIMITY OF THE SURFACE RIDGE AXIS
ACROSS OUR SOUTHEASTERN COUNTIES.
LITTLE CHANGE IS EXPECTED FOR SUNDAY...WITH SOUTHEAST WINDS LESS
THAN 10KT AND PERIODIC CIRRUS CLOUDS.
SHIMON
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1137 PM CST SAT NOV 17 2012
.DISCUSSION...
ISSUED 900 PM CST SAT NOV 17 2012
THE LARGE SURFACE HIGH EXTENDING FROM MAINE TO EASTERN TEXAS WILL
BE IN CONTROL OF OUR WEATHER OVERNIGHT. THE RIDGE AXIS EXTENDS
ACROSS OUR FAR EASTERN COUNTIES...WHICH WILL HELP KEEP WINDS LIGHT
SOUTHEAST OR CALM OVERNIGHT. CIRRUS CLOUDS MAY DRIFT ACROSS THE
SKY OCCASIONALLY TONIGHT...BUT ENOUGH CLEARING SHOULD DEVELOP TO
PROVIDE FAVORABLE RADIATIONAL COOLING CONDITIONS. THAT WILL ALLOW
TEMPS TO DIP INTO THE LOWER 30S BY SUNRISE SUNDAY.
SOME LIGHT FOG MAY DEVELOP LATE TONIGHT...BUT VISIBILITY SHOULD
REMAIN 4SM OR BETTER...SO NO REAL NEED TO ADD TO THE GRIDS AS
IMPACT WILL BE NEGLIGIBLE.
AS THE RIDGE AXIS SHIFTS FARTHER EAST OF ILLINOIS SUNDAY
MORNING...MID LEVEL TEMPS WILL BEGIN WARMING ON INCREASING
SOUTHERLY WINDS. THAT WILL HELP PUSH HIGH TEMPS A FEW DEGREES
WARMER THAN SATURDAY.
OUR LOW TEMP FORECAST TONIGHT LOOKED ON TRACK WITH EXPECTED
CONDITIONS. NO CHANGES APPEARED NECESSARY IN THE REMAINING GRIDS
FOR TONIGHT OR EARLY TOMORROW. NO FORMAL UPDATE WILL BE NEEDED
THIS EVENING.
SHIMON
&&
.AVIATION...
ISSUED 1137 PM CST SAT NOV 17 2012...FOR THE 06Z TAFS
FORECAST RAP SOUNDINGS ARE STILL INDICATING MVFR VIS OF 4-5SM BR
WILL BE POSSIBLE LATER TONIGHT. BASED ON A SIMILAR AIRMASS TO LAST
NIGHT...WE KEPT A MENTION OF MVFR FOG AT ALL BUT BMI FOR SEVERAL
HOURS FROM 10/11Z TO 15/16Z. CIRRUS CLOUDS HAVE MAINLY CLEARED OUT
TO THE EAST...SO RADIATIONAL COOLING CONDITIONS WILL SUPPORT OUR
AIR TEMPS DIPPING TO NEAR THE WET BULB LATER TONIGHT.
LIGHT SOUTHEAST OR CALM WINDS WILL PREVAIL DUE TO THE WEAK
PRESSURE GRADIENT AND THE PROXIMITY OF THE SURFACE RIDGE AXIS
ACROSS OUR SOUTHEASTERN COUNTIES.
LITTLE CHANGE IS EXPECTED FOR SUNDAY...WITH SOUTHEAST WINDS LESS
THAN 10KT AND PERIODIC CIRRUS CLOUDS.
SHIMON
&&
.PREV DISCUSSION...
ISSUED 246 PM CST SAT NOV 17 2012
ANOTHER DAY OF NOT MUCH TO TALK ABOUT WITH ONLY CONCERN BEING PCPN
CHANCES MON AND MON NIGHT...AND HOW WARM WILL IT GET THROUGH THE
PERIOD. MODELS IN THE SHORT TERM REMAIN SIMILAR AND CONSISTENT
FROM PREVIOUS RUNS...SO ONLY MAKING MINOR CHANGES TO GOING
FORECAST THROUGH TUESDAY. MODELS IN THE LONG TERM CONTINUE TO SHOW
DIFFERENCES IN TIMING WITH THE ONE SHORT WAVE/SYSTEM THAT MOVES
ACROSS THE AREA ON THANKSGIVING DAY/NIGHT. SO CONFIDENCE HAS NOT
CHANGED FROM PREVIOUS FORECASTS.
SHORT TERM...TONIGHT THROUGH TUESDAY
HIGH PRSS RIDGE OVER THE AREA WILL SLIDE SOUTHEAST TONIGHT AND
TOMORROW. THIS SHOULD ALLOW WAA TO OCCUR BACK INTO THE AREA AND AN
INCREASE OF LOW LEVEL MOISTURE. HOWEVER...SFC RIDGE WILL EXTEND
INTO THE GULF AND CUTOFF ANY RETURN OF MOISTURE TO THE AREA EARLY
NEXT WEEK. SO THE FRONTAL SYSTEM THAT IS MOVING TOWARD AND INTO
THE AREA MON NIGHT THROUGH TUE WILL HAVE VERY LIMITED MOISTURE TO
WORK WITH. SO WILL KEEP CURRENT FORECAST PRETTY CLOSE TO AS IS AND
STILL HAVE SLIGHT CHC FOR SHOWERS IN THE WEST FOR MONDAY AND
ACROSS THE WHOLE AREA FOR MONDAY NIGHT. ANY PCPN SHOULD BE WELL IN
THE WARM SECTOR SO AS THE FRONT MOVES INTO THE AREA FOR
TUESDAY...ANY PCPN WILL BE JUST EAST OF THE STATE.
DAYTIME TEMPS WILL BE ABOVE NORMAL ACROSS THE AREA. FOLLOWED
WARMER GUIDANCE...MET...FOR SUNDAY AND THEN BLEND FOR MONDAY AND
TUESDAY. SHOULD BE PLENTY OF SUNSHINE TOMORROW...THEN WILL HAVE TO
RELY ON WAA ON MONDAY AND TUESDAY...WHICH WILL HAVE LITTLE MORE
CLOUD COVER.
LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
STILL LOOKING AT A SOMEWHAT ZONAL PATTERN FOR REMAINDER OF THE
WEEK. BOTH MODELS SHOW A TROUGH/FRONTAL SYSTEM MOVING THROUGH THE
AREA THURSDAY-THURSDAY NIGHT...BUT TIMING DIFFERENCES HAVE GFS
QUICKER THAN ECMWF. ECMWF IS ALSO DEEPER WITH MID LEVEL TROUGH
THURSDAY NIGHT. SO WITH TIMING DIFFERENCES...WILL KEEP SLIGHT CHC
POPS IN GRIDS FOR THURSDAY NIGHT IN SOUTHEAST CWA...WHICH IS CLOSE
TO GOING FORECAST. REMAINDER OF THE TIME PERIOD WILL BE DRY AS
MOISTURE WILL REMAIN CUTOFF BY THE SFC RIDGE SITTING OVER THE
SOUTHEASTERN US AND INTO THE WESTERN GULF. TEMPS WILL REMAIN
WARM/ABOVE NORMAL WED AND THURSDAY...BUT THEN COOL SOME FOR FRIDAY
AND SAT...THOUGH STILL SLIGHTLY ABOVE NORMAL.
AUTEN
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
145 AM MST SUN NOV 18 2012
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 145 AM MST SUN NOV 18 2012
SUMMARY...DRY WEATHER WITH ABOVE NORMAL TEMPERATURES WILL CONTINUE
THROUGH THE SHORT TERM PART OF FORECAST.
TODAY...DEW POINT DEPRESSIONS CONTINUE TO LOWER EARLY THIS MORNING.
LATEST FOG PRODUCT SATELLITE IMAGERY DOES NOT SHOW ANY EVIDENCE OF
FOG FORMATION YET...BUT WITH LIGHT SURFACE WINDS...EXPECT SOME
PATCHY FOG TO DEVELOP SHORTLY BEFORE SUNRISE MAINLY ALONG HIGHWAY
83. LATEST HRRR MODEL SUPPORTS THIS. OTHERWISE...A WEAK SHORTWAVE
TROUGH WILL MOVE ACROSS THE FORECAST AREA DURING THE DAY...BUT
RAOBS/MODELS CONTINUE TO SHOW THAT THE AIR MASS WILL BE DRY. ONLY
MID AND HIGH LEVEL CLOUDS WILL ADVECT ACROSS THE AREA THIS AFTERNOON.
LEE SIDE SURFACE TROUGH WILL MOVE EAST THIS AFTERNOON AND WILL
SWITCH WINDS TO THE WEST ALONG THE COLORADO/KANSAS BORDER. WITH
LACK OF AIR MASS CHANGE...EXPECT TEMPERATURES TO BE SIMILAR TO
THOSE THAT OCCURRED SATURDAY.
TONIGHT...500 MB FLOW BECOMES INCREASINGLY ZONAL BEGINNING TONIGHT.
MODELS SHOW WEAK COLD AIR ADVECTION AT THE SURFACE STARTING AROUND
12Z.
MONDAY...DRY ZONAL MID LEVEL FLOW WILL CONTINUE. SURFACE WINDS WILL
BE NORTH BEHIND A PUSH OF SLIGHTLY COOLER AIR. ALTHOUGH 850 MB
TEMPERATURES COOL...THE COOLING IS VERY SLIGHT...ONLY ABOUT 1 DEGREE
CELSIUS. ONCE AGAIN...PERSISTENCE TEMPERATURE FORECASTS LOOK DECENT.
MONDAY NIGHT THROUGH TUESDAY NIGHT...500 MB RIDGE AND ASSOCIATED
SUBSIDENCE WILL DEVELOP OVER THE HIGH PLAINS. LEE SIDE TROUGH WILL
REFORM BY TUESDAY AFTERNOON BRINGING A RETURN OF SOUTH WINDS AND WEAK
WARM AIR ADVECTION.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 145 AM MST SUN NOV 18 2012
VERY LITTLE HAS CHANGED IN THE EXTENDED PERIODS WITH MODELS STILL
ADVERTISING PROGRESSIVE ZONAL PATTERN WITH MAIN STORM TRACK ALONG
US/CANADA BORDER. THERE ARE A FEW WEAK SHORTWAVE TROUGHS THAT COME
CLOSE TO THE CWA...HOWEVER WITH A DEEP DRY LAYER IN PLACE THE MOST
WE WOULD EXPECT TO SEE IS AN INCREASE IN MID-HIGH CLOUDS. RH VALUES
STILL LOOK TO BE NEAR RFW CRITERIA WEDNESDAY AFTERNOON...HOWEVER
SURFACE GRADIENT IS WEAK OVER THE CWA AND WINDS SHOULD BE WELL BELOW
CRITERIA.
OVERALL...STILL EXPECTING ABOVE NORMAL TEMPERATURES AND DRY CONDITIONS
TO CONTINUE. WED HIGHS WILL APPROACH 70F...WITH HIGHS IN THE UPPER
50S/NEAR 60F THROUGH THE REMAINING PERIODS AFTER A WEAK COLD FRONT
MOVES THROUGH THE REGION WED NIGHT/THU. OVERNIGHT LOWS SHOULD BE IN
THE LOW TO MID 30S EACH NIGHT...WHICH IS IS STILL ABOUT 10F ABOVE NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1000 PM MST SAT NOV 17 2012
RESTRICTED VISIBILITIES ARE POSSIBLE AT KGLD AND EXPECTED AT KMCK
AFTER 10Z OR SO THROUGH 15Z AS LOW LEVEL MOISTURE INCREASES AHEAD
OF A SFC TROUGH WHICH BY 12Z WILL BE ALONG THE CO/KS BORDER. THIS
TROUGH WILL SLOWLY MOVE EAST THROUGH THE DAY SUNDAY WITH W/NW WINDS
BEHIND IT AND SOUTHERLY WINDS AHEAD OF IT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...MENTZER
LONG TERM...DR
AVIATION...99
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1047 PM MST SAT NOV 17 2012
.AVIATION...
06Z TAF CYCLE
MID/HIGH LEVEL MOISTURE BOWING NORTHWARD OVER SOUTHERN AND
CENTRAL NEW MEXICO...WHILE TOP DOWN MOISTENING TO
CONTINUE...MAINLY EMBEDDED SCATTERED LIGHT SHOWERS WILL
RESULT...WHICH MAY OBSCURE HIGHER TERRAIN FAVORING AREAS SOUTH OF
HIGHWAY 60 NEXT 12 HOURS. IN ADDITION...DISTURBANCE PASSING
THROUGH GREAT BASIN AND CENTRAL ROCKIES MAY RESULT IN ISOLD -RASN
OR EVEN A SHORT LIVED THUNDERSTORM NEAR THE FOUR CORNERS AND THE
NORTHWEST MTS AND MAY RESULT IN BRIEF MT OBSCURATIONS THRU 12Z
SUNDAY. 00Z NAM12 AND LATEST RUC INDICATE SOME LOW/MID LEVEL
MOISTURE MAY MAKE A RUN UP THE RGV POSSIBLY REACHING KABQ BY 12Z
SUNDAY...THEREFORE MORE WIDESPREAD MT OBSCURATION POSSIBLE BUT CIGS
MAY REMAIN VFR.
&&
.DISCUSSION...TWO OPPORTUNITIES FOR PRECIPITATION THROUGH NEXT
WEEK...THE FIRST ONE THROUGH THE REMAINDER OF THIS WEEKEND AND THE
SECOND ONE WED AND WED NIGHT. OTHERWISE DRY WEATHER TO CONTINUE
WITH ONLY MINOR DAY TO DAY AND NIGHT TO NIGHT FLUCTUATIONS IN
TEMPERATURES. HIGH TEMPERATURES GENERALLY ABOVE NORMAL. NO STRONG
WINDS ARE EXPECTED WITH MODERATE BREEZES IN THE E SUN AND WED.
SHORT WAVE APPROACHING BAJA CA AND ANOTHER ONE OVER THE W COAST
WILL MOVE NE TON AND SUN. ENOUGH LOWER LEVEL MOISTURE SHOULD GET
DRAWN N INTO NM TO PRODUCE ISOLATED TO SCATTERED RAIN AND HIGHER
ELEVATION SNOW SHOWERS TON INTO SUN...EXCEPT IN THE NE. DEWPOINTS
CLIMBING INTO THE 20S AND 30S OVER THE SW ZONES WITH 30S AND 40S
DEWPOINTS ALREADY ACROSS THE EASTERN PLAINS.
DRYING TREND FOR LATE SUN INTO MON WITH A CHILLY NIGHT SUN NIGHT
BUT A NICE MON PM WITH ABOVE NORMAL TEMPS AND PLENTY OF SUNSHINE.
A WEAK BACK DOOR FRONT WILL SLOWLY PRESS S ACROSS THE EASTERN
PLAINS MON BUT HAVE LITTLE IMPACT ON THE SENSIBLE WEATHER. A
RIDGE OF HIGH PRESSURE WILL BUILD OVER THE STATE MON NIGHT THEN
SHIFT E TUE. IT WILL BE ANOTHER MILD DAY TUE WITH ABOVE NORMAL
TEMPERATURES.
MODELS REMAIN CONSISTENT IN BRINGING A LOW FROM OFF BAJA CA TUE
TO SOUTHERN NM WED. THEY VARY ON THE EXTENT OF QPF...WITH THE
EUROPEAN THE WETTEST FOLLOWED BY THE GFS THEN A MOSTLY DRY
CANADIAN MODEL. WILL CONTINUE WITH LOW CHANCES OF RAIN SHOWERS
OVER THE SC AND SE ZONES WED AND WED NIGHT.
THANKSGIVING DAY AND BLACK FRIDAY LOOKING MIGHTY FINE WITH DRY
CONDITIONS...LIGHT WINDS AND ABOVE NORMAL DAYTIME TEMPERATURES.
CHJ
&&
.FIRE WEATHER...
ABOVE NORMAL TEMPERATURES EXPECTED FOR THE NEXT 7 DAYS WITH
HUMIDITIES GENERALLY ABOVE CRITICAL THRESHOLDS. AN UPPER TROUGH
WILL BRING SMALL PRECIPITATION CHANCES LATE THIS AFTERNOON
THROUGH SUNDAY...AS WELL AS BREEZY CONDITIONS ACROSS THE PLAINS
SUNDAY AFTERNOON.
A BEAUTIFUL BAROCLINIC LEAF CLOUD MASS IS EVIDENT ON SATELLITE
IMAGERY THIS AFTERNOON ASSOCIATED WITH AN OTHERWISE WEAK UPPER
LEVEL TROUGH THAT WILL CROSS NEW MEXICO LATE THIS AFTERNOON
THROUGH SUNDAY. THE SYSTEM SHOULD PRODUCE MAINLY ISOLATED AND
LIGHT RAIN AND SNOW SHOWERS OVER CENTRAL...WESTERN AND SOUTHERN
AREAS AS IT CROSSES. A FEW POCKETS OF WETTING PRECIPITATION WILL
BE POSSIBLE ON THE WEST SLOPES OF THE SAN JUANS AND ACROSS THE
SOUTHERN TIER OF NEW MEXICOS MOUNTAINS. WINDS ALOFT WILL ALSO
STRENGTHEN WITH THE PASSING WEATHER SYSTEM...AND A LEE TROUGH IN
THE EAST WILL CAUSE WEST AND SOUTHWEST WINDS TO BECOME BREEZY
THERE SUNDAY AFTERNOON.
IN THE WAKE OF THE WEATHER SYSTEM...A WEAK COLD FRONT WILL SAG
SOUTHWARD THROUGH THE STATE MONDAY. AFTER HIGH TEMPERATURES A
FEW TO 14 DEGREES ABOVE NORMAL THIS WEEKEND...HIGHS WILL TREND
DOWNWARD A FEW DEGREES MONDAY AND ESPECIALLY TUESDAY.
NONETHELESS...READINGS WILL REMAIN 4 TO 11 DEGREES ABOVE NORMAL
ON TUESDAY...BEFORE WARMING SLIGHTLY WEDNESDAY.
THE GFS AND ECMWF CONTINUE TO AGREE ON A WEAK UPPER LEVEL TROUGH
TO EJECT FROM THE BAJA ACROSS NORTHERN MEXICO AND SOUTHERN NEW
MEXICO TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. AHEAD OF THE SYSTEM
A MOIST LOW LEVEL RETURN FLOW OUT OF THE SOUTHEAST SHOULD ENHANCE
MOISTURE ALONG AND EAST OF THE CENTRAL MOUNTAINS. THE SYSTEM MAY
FIND ENOUGH MOISTURE FOR A SLIGHT CHANCE OF RAIN SHOWERS IN
SOUTHERN AND EASTERN NM...AND SOME OF THESE SHOWERS MAY EXTEND AS
FAR NORTH AS THE MANZANO AND GALLINAS MOUNTAINS AND SOUTHERN PARTS
OF THE EAST CENTRAL PLAINS. THE LOW LEVEL MOISTURE TAP WITH THE
SYSTEM WILL PROBABLY BE TOO SHALLOW FOR MORE THAN SPOTTY WETTING
PRECIPITATION. ANOTHER WEAK COLD FRONT WILL SAG SOUTHWARD THROUGH
THE FORECAST AREA ON THURSDAY IN THE WAKE OF THE PASSING WAVE...
CAUSING TEMPERATURES TO TREND SLIGHTLY COOLER THURSDAY AND FRIDAY.
AFTER GOOD TO EXCELLENT VENTILATION IN MOST LOCATIONS OVER THE
WEEKEND...POOR VENTILATION WILL SPREAD ACROSS CENTRAL AND WESTERN
PARTS OF THE FORECAST AREA FROM THE WEST DURING THE FIRST HALF OF
THE COMING WORK WEEK. DURING THE LATTER HALF OF THE WEEK THE POOR
VENTILATION MAY BE COME EVEN MORE WIDESPREAD...EXPANDING TO INCLUDE
THE EASTERN PLAINS BY FRIDAY. 44
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS RALEIGH NC
247 AM EST SUN NOV 18 2012
.SYNOPSIS...
THROUGH EARLY NEXT WEEK...STRONG HIGH PRESSURE WILL EXTEND ACROSS
MUCH OF THE EASTERN US...WHILE A WEAK LOW PRESSURE SYSTEM WILL
MEANDER OFF THE SOUTHEAST COAST.
&&
.NEAR TERM /THROUGH SUNDAY NIGHT/...
AS OF 930 PM SATURDAY...
REST OF TONIGHT: COMPLEX PATTERN ACROSS THE SOUTHEAST AND
MIDATLANTIC THIS EVENING... AND THE MAIN FORECAST CONCERN REMAINS
THE CHANCE FOR RAIN OVERNIGHT. SURFACE HIGH PRESSURE REMAINS QUITE
STRONG (OVER 1038 MB) CENTERED OVER THE ST LAWRENCE VALLEY AND
EXTENDING SOUTHWARD THROUGH NC... WHILE A STRENGTHENING LOW LEVEL
FRONTAL ZONE AND DEVELOPING LOW PRESSURE OFF THE SOUTHEAST COAST IS
EXPECTED TO GENERATE A TIGHTENING MSLP GRADIENT OVERNIGHT...
ESPECIALLY OVER THE SRN AND ERN CWA. CONVECTION WAS WIDESPREAD JUST
OFF THE CAROLINA COAST THIS AFTERNOON... AND WHILE THE INTENSITY OF
THIS RAIN HAS DECREASED... IT REMAINS IN PLACE JUST OFF THE SC AND
SRN NC COAST. THE 12Z 4-KM WRF-ARW AND WRF-NMM DID A SUBPAR JOB IN
DEPICTING THIS RAIN... ALTHOUGH THE 18Z LOCAL WRF-ARW DID BETTER AND
IS SIMILAR TO THE LATEST HRRR OUTPUT... WHICH SHOWS THE BULK OF THE
RAIN SHIELD HOLDING OVER AND JUST OFF THE SC COAST WITH JUST PATCHY
RAIN SPREADING INTO OUR FAR SOUTHEAST COUNTIES OVERNIGHT. THIS ALSO
APPEARS IN LINE WITH THE LATEST SREF PROBABILITIES OF MEASURABLE
RAIN... WHICH KEEPS CHANCES UNDER 30 PERCENT IN THE SOUTHEAST
TONIGHT. BASED ON THIS AND MODEL AGREEMENT ON ACCELERATING LOW LEVEL
MOISTURE TRANSPORT TONIGHT AND THE PACE AT WHICH THE LOWER STRATUS
AND SMALLER DEW POINT DEPRESSION AIR IS SPREADING WESTWARD INTO
SOUTHEAST NC... WILL HOLD ONTO A SLIGHT CHANCE OF RAIN TONIGHT IN
THIS AREA. FORECAST SOUNDINGS DEPICT A FAIRLY DEEP (3000-4000 FT
THICK) SURFACE-BASED STABLE LAYER... BUT CLOSE EXAMINATION REVEALS A
VERY SHALLOW (FEW HUNDRED FEET) SLIGHTLY MIXED LAYER RIGHT AT THE
SURFACE... REASONABLE CONSIDERING HOW THE WINDS THROUGHOUT THE
LOWEST FEW THOUSAND FEET WILL BE STRENGTHENING AT ONCE. WILL KEEP
WINDS UP OVERNIGHT WITH PERIODIC GUSTS. THE LOW LEVEL STIRRING WILL
HOLD TEMPS UP... AND EXPECT LOWS OF 38-48. -GIH
SUNDAY AND SUNDAY NIGHT...THE MID LEVEL ANTI-CYCLONE OFF THE
SOUTHERN NEW ENGLAND COAST AND THE NE FL/SRN GA COAST WILL MAINTAIN
A DEEP ELY FLOW INTO CENTRAL NC WITH SPEED CONFLUENCE NOTED OVER THE
REGION DURING THE AFTERNOON-EARLY EVENING HOURS. THE LIFT SUPPLIED
BY THIS CONFLUENCE WILL GENERATE AREAS OF LIGHT RAIN...MAINLY ALONG
THE I-95 CORRIDOR. FARTHER WEST...LIFT WEAKER TO NON-EXISTENT. THIS
WILL LEAD TO PRECIP CHANCES RANGING FROM LIKELY IN THE EAST TO LOW
END CHANCE-SLIGHT CHANCE IN THE FAR WEST LATE SUNDAY INTO SUNDAY
NIGHT.
EXPECT A NARROW DIURNAL TEMP RANGE SUNDAY SUNDAY NIGHT DUE TO CLOUDS
AND PRECIP. MAX TEMPS LOW-MID 50S SUNDAY.MIN TEMPS SUNDAY NIGHT
AROUND 40 NW TO UPPER 40S/NEAR 50 E-SE. -WSS
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
AS OF 245 AM SUNDAY...
MONDAY NIGHT:
SURFACE LOW OFF THE NC COAST CONTINUES TO MIGRATE SLOWLY TO THE NE
WITH RIDGING OVER NC AND SURFACE HIGH OVER NEW ENGLAND. OFFSHORE LOW
BECOMES MORE VERTICALLY STACKED WITH THE UPPER LEVEL LOW OFFSHORE
AND RIDGING OVER NC. CENTRAL NC SHOULD REMAIN DRY OVERNIGHT...WITH
THE BEST CHANCES FOR LINGERING PRECIP ALONG THE NC COAST. WINDS WILL
BE STRONGEST FARTHER EAST...5 TO 10 KTS. LOWS EXPECTED IN THE MID
40S.
TUESDAY THROUGH WEDNESDAY:
SURFACE HIGH PRESSURE REMAINS IN PLACE AS AN UPPER LEVEL TROUGH
MOVES IN FROM THE WEST...WITH A S/W AHEAD OF THE MAIN TROUGH AXIS.
ALTHOUGH THERE IS STRONG VORTICITY AT THE UPPER LEVELS WITH THE
TROUGH AXIS...SURFACE HIGH PRESSURE...WITH ITS ASSOCIATED STABILITY
AND SUBSIDENCE IN THE LOWER LEVELS SHOULD KEEP THE CHANCES FOR
PRECIP LOW. THERE IS STILL SOME DIFFERENCE BETWEEN THE MODELS WITH
REGARD TO PRECIP GENERATION WITH THE INITIAL S/W...AS THE 12Z ECMWF
GENERATES PRECIP WHILE THE 00Z GFS REMAINS DRY THROUGHOUT. AS
SUCH...WILL KEEP SLIGHT CHANCE FOR RAIN TUESDAY AND TUESDAY NIGHT
AND A DRY FORECAST FOR WEDNESDAY...WITH OVERCAST SKIES EXPECTED
TUESDAY AND TUESDAY NIGHT. STRONGEST WINDS IN THE EAST WHERE THE
PRESSURE GRADIENT BETWEEN THE SURFACE HIGH AND OFFSHORE LOW IS THE
GREATEST. HIGHS NEAR NORMAL...IN THE UPPER 50S TO LOW 60S TUESDAY
AND WEDNESDAY WITH LOWS TUESDAY NIGHT IN THE LOW TO MID 40S.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
AS OF 245 AM SUNDAY...
SKIES WILL START CLEARING WEDNESDAY AFTERNOON AS THE UPPER LEVEL
TROUGH MOVES OFFSHORE. AS THE TROUGH MOVES OFFSHORE THE SURFACE LOW
OFF THE NC COAST WILL STRENGTHEN. THE LOW SHOULD BE FAR ENOUGH
OFFSHORE TO KEEP PRECIP OUT OF THE AREA. WITH THE RIDGE BUILDING
INTO THE AREA AT THE SURFACE AND ALOFT THURSDAY MORNING AND
REMAINING OVER CENTRAL NC THROUGH FRIDAY...WILL KEEP THE FORECAST
DRY THROUGH THAT PERIOD. HIGH TEMPS WILL BE IN THE MID 60S THURSDAY
AND FRIDAY WITH LOWS WEDNESDAY...THURSDAY...AND FRIDAY NIGHTS
RANGING FROM THE MID 30S TO LOW 40S. THERE ARE LARGE DIFFERENCES
BETWEEN THE 12Z ECMWF AND 00Z GFS FRIDAY AND SATURDAY WITH REGARD TO
WHETHER AN UPPER LEVEL LOW AND ASSOCIATED TROUGH (ECMWF) WILL
DEVELOP AND DIG INTO THE AREA FRIDAY NIGHT OR WHETHER THE PATTERN
ALOFT WILL REMAIN MORE ZONAL FRIDAY NIGHT...WITH A WEAKER TROUGH
DEVELOPING TO THE WEST LATE SATURDAY (GFS). PRECIP CHANCES WILL
DEPEND UPON THE TIMING AND STRENGTH OF THIS SYSTEM. WITH THE GREAT
DEAL OF UNCERTAINTY IN THE MODELS...CONFIDENCE IN THE PRECIP
FORECAST FRIDAY AND SATURDAY IS LOW...BUT FOR NOW WILL KEEP IT DRY.
HIGHS ON SATURDAY WILL ALSO BE IMPACTED IF PRECIP DOES DEVELOP...BUT
STAYING CONSISTENT WITH THE DRY FORECAST...ANTICIPATE HIGHS IN THE
UPPER 50S TO LOW 60S.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 125 AM SUNDAY...
THE PRESSURE GRADIENT BETWEEN STRONG HIGH PRESSURE OVER THE
NORTHEAST AND A FRONTAL ZONE AND DEVELOPING AREA OF LOW PRESSURE OFF
THE SOUTHEAST US COAST WILL PRODUCE STRONG NORTHEASTERLY LOW LEVEL
FLOW THAT WILL RESULT IN BOTH THE EXPANSION OF 1000-2000 FT (MVFR)
CEILINGS THIS MORNING AND BREEZY AND GUSTY NE SURFACE WINDS THROUGH
THE TAF PERIOD. THE CEILINGS MAY BRIEFLY LOWER TO IFR RANGE...JUST
BELOW 1000 FT...FOR A FEW HOURS THIS MORNING AT KRWI/KRDU...BUT
PREDOMINATELY MVFR CEILINGS ARE EXPECTED. THE OFFSHORE AREA OF LOW
PRESSURE WILL ALSO RESULT IN PATCHY LIGHT RAIN TODAY AND TONIGHT
MAINLY AT KFAY/KRWI/KRDU...AS IT MEANDERS OFF THE SOUTHEAST COAST.
LOOKING AHEAD: WHILE THE WINDS WILL GRADUALLY LESSEN BY MON...OWING
TO A STEADY WEAKENING OF THE SURFACE HIGH OVER THE NORTHEAST AND
CONSEQUENT RELAXATION OF THE MSL PRESSURE GRADIENT...THE WEAKENED
NORTHEASTERLY FLOW WILL REMAIN MOIST AND MAINTAIN A HIGH PROBABILITY
OF MVFR RANGE CEILINGS THROUGH EARLY TUE.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...HARTFIELD/WSS
SHORT TERM...KC
LONG TERM...KC
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
130 AM EST SUN NOV 18 2012
.SYNOPSIS...
THROUGH EARLY NEXT WEEK...STRONG HIGH PRESSURE WILL EXTEND ACROSS
MUCH OF THE EASTERN US...WHILE A WEAK LOW PRESSURE SYSTEM WILL
MEANDER OFF THE SOUTHEAST COAST.
&&
.NEAR TERM /THROUGH SUNDAY NIGHT/...
AS OF 930 PM SATURDAY...
REST OF TONIGHT: COMPLEX PATTERN ACROSS THE SOUTHEAST AND
MIDATLANTIC THIS EVENING... AND THE MAIN FORECAST CONCERN REMAINS
THE CHANCE FOR RAIN OVERNIGHT. SURFACE HIGH PRESSURE REMAINS QUITE
STRONG (OVER 1038 MB) CENTERED OVER THE ST LAWRENCE VALLEY AND
EXTENDING SOUTHWARD THROUGH NC... WHILE A STRENGTHENING LOW LEVEL
FRONTAL ZONE AND DEVELOPING LOW PRESSURE OFF THE SOUTHEAST COAST IS
EXPECTED TO GENERATE A TIGHTENING MSLP GRADIENT OVERNIGHT...
ESPECIALLY OVER THE SRN AND ERN CWA. CONVECTION WAS WIDESPREAD JUST
OFF THE CAROLINA COAST THIS AFTERNOON... AND WHILE THE INTENSITY OF
THIS RAIN HAS DECREASED... IT REMAINS IN PLACE JUST OFF THE SC AND
SRN NC COAST. THE 12Z 4-KM WRF-ARW AND WRF-NMM DID A SUBPAR JOB IN
DEPICTING THIS RAIN... ALTHOUGH THE 18Z LOCAL WRF-ARW DID BETTER AND
IS SIMILAR TO THE LATEST HRRR OUTPUT... WHICH SHOWS THE BULK OF THE
RAIN SHIELD HOLDING OVER AND JUST OFF THE SC COAST WITH JUST PATCHY
RAIN SPREADING INTO OUR FAR SOUTHEAST COUNTIES OVERNIGHT. THIS ALSO
APPEARS IN LINE WITH THE LATEST SREF PROBABILITIES OF MEASURABLE
RAIN... WHICH KEEPS CHANCES UNDER 30 PERCENT IN THE SOUTHEAST
TONIGHT. BASED ON THIS AND MODEL AGREEMENT ON ACCELERATING LOW LEVEL
MOISTURE TRANSPORT TONIGHT AND THE PACE AT WHICH THE LOWER STRATUS
AND SMALLER DEW POINT DEPRESSION AIR IS SPREADING WESTWARD INTO
SOUTHEAST NC... WILL HOLD ONTO A SLIGHT CHANCE OF RAIN TONIGHT IN
THIS AREA. FORECAST SOUNDINGS DEPICT A FAIRLY DEEP (3000-4000 FT
THICK) SURFACE-BASED STABLE LAYER... BUT CLOSE EXAMINATION REVEALS A
VERY SHALLOW (FEW HUNDRED FEET) SLIGHTLY MIXED LAYER RIGHT AT THE
SURFACE... REASONABLE CONSIDERING HOW THE WINDS THROUGHOUT THE
LOWEST FEW THOUSAND FEET WILL BE STRENGTHENING AT ONCE. WILL KEEP
WINDS UP OVERNIGHT WITH PERIODIC GUSTS. THE LOW LEVEL STIRRING WILL
HOLD TEMPS UP... AND EXPECT LOWS OF 38-48. -GIH
SUNDAY AND SUNDAY NIGHT...THE MID LEVEL ANTI-CYCLONE OFF THE
SOUTHERN NEW ENGLAND COAST AND THE NE FL/SRN GA COAST WILL MAINTAIN
A DEEP ELY FLOW INTO CENTRAL NC WITH SPEED CONFLUENCE NOTED OVER THE
REGION DURING THE AFTERNOON-EARLY EVENING HOURS. THE LIFT SUPPLIED
BY THIS CONFLUENCE WILL GENERATE AREAS OF LIGHT RAIN...MAINLY ALONG
THE I-95 CORRIDOR. FARTHER WEST...LIFT WEAKER TO NON-EXISTENT. THIS
WILL LEAD TO PRECIP CHANCES RANGING FROM LIKELY IN THE EAST TO LOW
END CHANCE-SLIGHT CHANCE IN THE FAR WEST LATE SUNDAY INTO SUNDAY
NIGHT.
EXPECT A NARROW DIURNAL TEMP RANGE SUNDAY SUNDAY NIGHT DUE TO CLOUDS
AND PRECIP. MAX TEMPS LOW-MID 50S SUNDAY.MIN TEMPS SUNDAY NIGHT
AROUND 40 NW TO UPPER 40S/NEAR 50 E-SE. -WSS
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 310 PM SATURDAY...
MONDAY AND MONDAY NIGHT...WHILE MID LEVEL ANTI-CYCLONE WILL REMAIN
NEARLY STATIONARY OFF THE NORTHERN MID ATLANTIC COAST...THE AREA OF
LOW PRESSURE OFF THE NE FL COAST WILL LIFT TO THE ENE. THIS MOVEMENT
OF THE LOW WILL CAUSE THE MID LEVEL FLOW OVER CENTRAL NC TO WEAKEN
AND BECOME MORE NELY. THUS...EXPECT RAIN CHANCES TO DWINDLE MONDAY
WITH A SLIGHT CHANCE POP CONFINED TO THE EASTERN HALF BY
AFTERNOON....AND LITTLE IF ANY RAIN EXPECTED MONDAY NIGHT. MODEL
GUIDANCE DIFFERS AS TO THE AMOUNT OF DECREASING CLOUDINESS TO OCCUR
WHICH LEADS TO DISCREPANCIES IN THE TEMP GUIDANCE MONDAY. LATEST NAM
MORE EMPHATIC WITH ITS CLEARING TREND WHICH TRANSLATES TO WARMER
AFTERNOON TEMPS. THE 12Z ECMWF WEAKEN OFFERS A SCENARIO SOMEWHAT BUT
NOT AS EMPHATIC WITH THE AMOUNT OF DRYING. GFS MAINTAINS A SATURATED
AIR MASS THROUGH THE PERIOD. PLACED A BIT MORE EMPHASIS TOT EH GFS
AS POTENTIAL EXIST FOR MOISTURE TO BE TRAPPED BELOW MID LEVEL
SUBSIDENCE INVERSION. THUS WILL FAVOR HIGH TEMPS MONDAY TOWARD THE
COOLER GFS MOS.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 310 PM SATURDAY...
BRIEF S/W RIDING ALOFT AT THE START OF THE MEDIUM RANGE PERIOD IS
EXPECTED TO QUICKLY SHIFT TO THE EAST OF THE AREA ON TUESDAY AS A
PAIR OF MID/UPPER LEVEL DISTURBANCES USHER IN A RETURN TO POSSIBLE
UNSETTLE WEATHER. HOWEVER... AT THE SURFACE/LOW LEVELS OF THE
ATMOSPHERE EXPECT A GENERALLY NORTHERLY FLOW WILL CONTINUE... WITH
THE AFOREMENTIONED SURFACE LOW PRESSURE EXPECTED TO REMAIN OFFSHORE
OR SLOWLY LIFT NORTH OR NORTHEASTWARD. MODELS ARE CONTINUING TO
STRUGGLE THOUGH WRT POSSIBLE LIGHT RAIN FOR TUESDAY INTO TUESDAY
NIGHT. THE DIFFERENCES APPEAR TO BE TIED TO THE STRENGTH IN THE
MID/UPPER LEVEL RIDGING AND APPROACHING NEXT SET OF IMPULSES ALOFT.
FOR NOW WILL TREND THE FORECAST TO THE DRIER SIDE OF GUIDANCE
(CLOSER TO THE ECMWF AND NAM). FOR NOW WILL LOWER POPS TO SLIGHT
CHANCE AREAWIDE. HOWEVER... STILL EXPECT SKIES WILL BE AT LEAST
MOSTLY CLOUDY WHICH WILL STILL HELP SUPPRESS HIGH TEMPS DESPITE LOW
LEVEL THICKNESS VALUES AROUND NORMAL. WILL GO WITH HIGH TEMPS IN THE
UPPER 50S TO AROUND 60... A BIT BELOW NORMAL. HOWEVER... IF THE RAIN
DOES MATERIALIZE EXPECTED TEMPS WOULD BE A GOOD 5 TO 10 DEGREES
COOLER AT LEAST THAN CURRENT FORECAST. LOW TUESDAY NIGHT/WEDNESDAY
MORNING ARE EXPECTED TO BE IN THE LOWER TO MID 40S... WITH SKIES
BEGINNING TO CLEAR AT BIT (MORE SO WEST) AS THE FIRST DISTURBANCE
BEGINS TO PUSH TO THE EAST OF THE AREA.
MID/UPPER LEVEL TROUGH AXIS IS EXPECTED TO AMPLIFY ACROSS THE AREA
AGAIN ON WEDNESDAY AS A SECOND S/W TROUGH ROTATES THROUGH THE AREA
ON WEDNESDAY/WEDNESDAY NIGHT. HOWEVER... DESPITE THE DEEPENING
TROUGH... BEST LIFT AND MOISTURE SHOULD REMAIN TO THE SOUTH OF THE
AREA. THUS... WITH AFTERNOON LOW LEVEL THICKNESS VALUES AROUND
NORMAL AND SKIES BECOMING PARTLY SUNNY LATE IN THE DAY EXPECT HIGH
TEMPS TO BE IN THE UPPER 50S TO LOWER 60S. LOWS WITH CLEARING SKIES
ON THURSDAY MORNING ARE EXPECTED TO RANGE FROM THE MID 30S TO LOWER
40S.
THURSDAY THROUGH SATURDAY:
RIDGING ALOFT IS EXPECTED TO BUILD ACROSS THE AREA DURING THIS
TIMEFRAME... WHILE A NORTHERN STREAM SYSTEM IS EXPECTED TO MOVE
ACROSS THE NORTHERN PORTION OF THE COUNTRY. AT THE SURFACE EXPECT
HIGH PRESSURE WILL REMAIN ACROSS THE AREA THROUGH AT LEAST FRIDAY
MORNING/AFTERNOON... BEFORE A TRAILING DRY COLD FRONT ASSOCIATED
WITH THE NORTHERN STREAM SYSTEM IS EXPECTED TO MOVE THROUGH THE AREA
LATE FRIDAY INTO FRIDAY NIGHT. HIGH PRESSURE IS EXPECTED TO BUILD
INTO THE AREA BEHIND THE FRONT ON SATURDAY. EXPECT ABOVE NORMAL
TEMPS THURSDAY/FRIDAY... WITH NEAR TO SLIGHTLY BELOW NORMAL TEMPS ON
SATURDAY. EXPECT HIGH TEMPS IN THE 60S THURSDAY/FRIDAY TO UPPER 50S
TO AROUND 60 NEXT SATURDAY. LOWS IN THE UPPER 30S TO LOWER 40S...
WITH POSSIBLE MID 30S IN THE USUAL RURAL COOL/COLDER AREAS.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 125 AM SUNDAY...
THE PRESSURE GRADIENT BETWEEN STRONG HIGH PRESSURE OVER THE
NORTHEAST AND A FRONTAL ZONE AND DEVELOPING AREA OF LOW PRESSURE OFF
THE SOUTHEAST US COAST WILL PRODUCE STRONG NORTHEASTERLY LOW LEVEL
FLOW THAT WILL RESULT IN BOTH THE EXPANSION OF 1000-2000 FT (MVFR)
CEILINGS THIS MORNING AND BREEZY AND GUSTY NE SURFACE WINDS THROUGH
THE TAF PERIOD. THE CEILINGS MAY BRIEFLY LOWER TO IFR RANGE...JUST
BELOW 1000 FT...FOR A FEW HOURS THIS MORNING AT KRWI/KRDU...BUT
PREDOMINATELY MVFR CEILINGS ARE EXPECTED. THE OFFSHORE AREA OF LOW
PRESSURE WILL ALSO RESULT IN PATCHY LIGHT RAIN TODAY AND TONIGHT
MAINLY AT KFAY/KRWI/KRDU...AS IT MEANDERS OFF THE SOUTHEAST COAST.
LOOKING AHEAD: WHILE THE WINDS WILL GRADUALLY LESSEN BY MON...OWING
TO A STEADY WEAKENING OF THE SURFACE HIGH OVER THE NORTHEAST AND
CONSEQUENT RELAXATION OF THE MSL PRESSURE GRADIENT...THE WEAKENED
NORTHEASTERLY FLOW WILL REMAIN MOIST AND MAINTAIN A HIGH PROBABILITY
OF MVFR RANGE CEILINGS THROUGH EARLY TUE.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...HARTFIELD/WSS
SHORT TERM...WSS
LONG TERM...BSD
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS SPOKANE WA
956 PM PST Sat Nov 17 2012
.SYNOPSIS...
Through next week expect a progressive and wet weather pattern to
return with periods of mountain snow and valley rain this weekend
and through next week. Higher snow levels Sunday Night through
Tuesday morning will combine with the heaviest expected
precipitation in this forecast cycle to produce rises on the areas
small stream or creeks...especially for North Idaho. Windy
conditions will develop over portions of the Inland Northwest on
Monday.
&&
.DISCUSSION...
...Areas of heavy rain...mountain snow...along with windy
conditions early next week....
Update...Radar imagery as of 945 pm indicated a large area of rain
associated with a cold front from Republic to Moses Lake eastward to
near the Washington/Idaho Border. The GFS/NAM/HRRR shows this area
of rain moving east through tonight with drier air and downslope
flow off the Cascades bringing a drying trend from west to east.
The HRRR which has a good handle on this area of rain shows the
back edge of the rain passing through Moses Lake around 10 pm,
Spokane 1 am, and Sandpoint 3 am. This matches the trends from the
NAM well so opted to update the forecast tonight to show these
trends in the NDFD grids. However some showers may linger over the
mountains of NE Washington and N Idaho Sunday morning after the
front passes due to the 850-700mb layer remaining nearly saturated
along with upslope flow.
No big changes noted on the 00z GFS run concerning the active
period expected for early next week with heavy mountain snow along
the East Slopes of the Cascades and Northern Mountains, windy
weather across portions of the area, along with heavy rain for
much of the Inland Northwest. See previous forecast discussion and
latest Weather Stories on our home page for more information. JW
&&
.AVIATION...
06Z TAFs: Rain will persist through 08-11z over Eastern Washington
and North Idaho as a cold front tracks through the area. Expect
lowering cigs and vis into MVFR category with rain this evening.
Moist upslope flow over the Spokane/Coeur d`Alene taf sites behind
the front is expected to lower cigs into the IFR category through at
least the early morning hours on Sunday. We will see a break in the
precipitation Sunday morning with another round of rain crossing the
Cascades around 00z Monday as a warm front moves in. Good mixing
potential on Sunday afternoon may result in gusts up to 20-25 kts
for the KGEG, KSFF, KCOE, KPUW and KMWH taf sites. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 37 45 38 42 40 46 / 100 50 100 100 100 80
Coeur d`Alene 37 45 36 42 40 46 / 100 50 90 100 100 80
Pullman 37 47 38 44 42 49 / 100 30 80 70 100 80
Lewiston 40 53 42 50 45 53 / 90 20 60 70 90 70
Colville 37 43 38 41 38 47 / 100 50 100 100 100 80
Sandpoint 37 44 35 41 38 44 / 100 80 90 100 100 100
Kellogg 37 41 34 39 39 44 / 100 80 60 100 100 100
Moses Lake 36 47 39 47 40 49 / 70 10 60 50 70 60
Wenatchee 37 45 38 44 39 47 / 40 20 90 50 70 60
Omak 35 42 37 42 39 45 / 100 30 100 100 70 60
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...High Wind Watch from late Sunday night through Monday evening
for Coeur d`Alene Area-Idaho Palouse.
Winter Storm Watch from Sunday evening through late Monday night
for Northern Panhandle.
WA...Winter Storm Watch from Sunday afternoon through Monday evening
for East Slopes Northern Cascades.
High Wind Watch from late Sunday night through Monday evening
for Lower Garfield and Asotin Counties-Moses Lake Area-
Northeast Blue Mountains-Northeast Mountains-Okanogan
Highlands-Spokane Area-Upper Columbia Basin-Washington
Palouse.
Winter Storm Watch from Sunday evening through late Monday night
for Northeast Mountains-Okanogan Highlands.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
828 PM PST Sat Nov 17 2012
.SYNOPSIS...
Through next week expect a progressive and wet weather pattern to
return with periods of mountain snow and valley rain this weekend
and through next week. Higher snow levels Sunday Night through
Tuesday morning will combine with the heaviest expected
precipitation in this forecast cycle to produce rises on the areas
small stream or creeks...especially for North Idaho. Windy
conditions will develop over portions of the Inland Northwest on
Monday.
&&
.DISCUSSION...
...Areas of heavy rain...mountain snow...along with windy
conditions early next week....
Update...Radar imagery as of 8 pm indicated a large area of rain
associated with a cold front from Omak to Moses Lake eastward to
near the Washington/Idaho Border. The GFS/NAM/HRRR shows this area
of rain moving east through tonight with drier air and downslope
flow off the Cascades bringing a drying trend from west to east.
The HRRR which has a good handle on this area of rain shows the
back edge of the rain passing through Moses Lake around 10 pm,
Spokane 1 am, and Sandpoint 3 am. This matches the trends from the
NAM well so opted to update the forecast tonight to show these
trends in the NDFD grids. However some showers may linger over the
mountains of NE Washington and N Idaho Sunday morning after the
front passes due to the 850-700mb layer remaining nearly saturated
along with upslope flow.
No big changes noted on the 00z GFS run concerning the active
period expected for early next week with heavy mountain snow along
the East Slopes of the Cascades and Northern Mountains, windy
weather across portions of the area, along with heavy rain for
much of the Inland Northwest. See previous forecast discussion and
latest Weather Stories on our home page for more information. JW
&&
.AVIATION...
00Z TAFs: A cold front is pushing into coastal Washington this evening.
Moist isentropic accent ahead of the front will result in light rain
at all taf sites this evening. Rainfall will diminish from west to
east late this evening into tonight as the front pushes east of the
region. Expect lowering cigs and vis into MVFR category with rain
this evening. Moist upslope flow over the Spokane/Coeur d`Alene taf
sites behind the front is expected to lower cigs into the IFR
category through at least the early morning hours on Sunday. We will
see a break in the precipitation Sunday morning with rain returning
Sunday afternoon as a warm front pushes in. Good mixing potential on
Sunday afternoon may result in a gusts up to 20-25 kts for the KGEG,
KSFF, KCOE, KPUW and KMWH taf sites. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 37 45 38 42 40 46 / 100 50 100 100 100 80
Coeur d`Alene 37 45 36 42 40 46 / 100 50 90 100 100 80
Pullman 37 47 38 44 42 49 / 100 30 80 70 100 80
Lewiston 40 53 42 50 45 53 / 90 20 60 70 90 70
Colville 37 43 38 41 38 47 / 100 50 100 100 100 80
Sandpoint 37 44 35 41 38 44 / 100 80 90 100 100 100
Kellogg 37 41 34 39 39 44 / 100 80 60 100 100 100
Moses Lake 36 47 39 47 40 49 / 70 10 60 50 70 60
Wenatchee 37 45 38 44 39 47 / 40 20 90 50 70 60
Omak 35 42 37 42 39 45 / 100 30 100 100 70 60
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...High Wind Watch from late Sunday night through Monday evening
for Coeur d`Alene Area-Idaho Palouse.
Winter Storm Watch from Sunday evening through late Monday night
for Northern Panhandle.
WA...Winter Storm Watch from Sunday afternoon through Monday evening
for East Slopes Northern Cascades.
High Wind Watch from late Sunday night through Monday evening
for Lower Garfield and Asotin Counties-Moses Lake Area-
Northeast Blue Mountains-Northeast Mountains-Okanogan
Highlands-Spokane Area-Upper Columbia Basin-Washington
Palouse.
Winter Storm Watch from Sunday evening through late Monday night
for Northeast Mountains-Okanogan Highlands.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
212 AM CST SUN NOV 18 2012
.SHORT TERM...THROUGH TUESDAY NIGHT
212 AM CST SUN NOV 18 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION CHANCES TONIGHT INTO
MONDAY AS WELL AS TEMPERATURES THROUGHOUT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A DEEP TROUGH FROM JUST OFF THE COAST OF BRITISH COLUMBIA
INTO THE PACIFIC NORTHWEST...AND SOUTHWEST FLOW FROM THE DESERT
SOUTHWEST THROUGH THE UPPER MISSISSIPPI RIVER VALLEY REGION. WITHIN
THIS SOUTHWEST FLOW...SHORTWAVES OF NOTE ARE ALONG THE UTAH/COLORADO
BORDER AND IN NORTHWEST MINNESOTA. DPVA AHEAD OF THIS LATTER
SHORTWAVE COMBINED WITH 295-300K ISENTROPIC LIFT PRODUCED SHOWERS
ACROSS NORTHEAST MINNESOTA. THE 295K ISENTROPIC LIFT ALSO EXTENDED
SOUTHWEST FROM NORTHEAST MINNESOTA INTO CENTRAL IOWA...AND ALONG
THIS ZONE IS A BAND OF STRATUS WITH CEILINGS BETWEEN 6000-9000 FT.
THE BAND OF STRATUS ALSO SEPARATES MOIST AIR FROM VERY DRY AIR AT
850MB. FOR EXAMPLE...FROM 00Z SOUNDINGS...THE 850MB DEWPOINT AT DVN
WAS -20C WHILE IT WAS -2C AT MPX AND 1C AT OAX. THE BROAD SOUTHWEST
FLOW ALOFT HAS RESULTED IN A WARM ADVECTION PATTERN ACROSS THE UPPER
MIDWEST. 850MB TEMPS WERE +6C AT MPX AND OAX AT 00Z. THE LOW LEVEL
SOUTHERLY FLOW WAS FAIRLY STRONG WITH 925MB PROFILER AND VWP DATA
SHOWING SPEEDS OF 35-45KT AROUND THE FORECAST AREA. THESE WINDS ARE
HOLDING TEMPERATURES UP FROM THE MID 30S TO MID 40S...WARMEST IN
SOUTHEAST MINNESOTA.
TODAY AND TONIGHT...FOCUS IS ON THAT SHORTWAVE ALONG THE
UTAH/COLORADO BORDER. GOOD MODEL AGREEMENT REMAINS ON THIS SHORTWAVE
LIFTING UP THROUGH THE SOUTHWEST FLOW AND MOVING INTO WESTERN
PORTIONS OF THE FORECAST AREA BY 12Z MONDAY. BRIEF RIDGING DEVELOPS
OVER THE FORECAST AREA TODAY DOWNSTREAM OF THIS SHORTWAVE...WHICH
SHOULD ACT TO CLEAR THE CLOUDS UP SOMEWHAT. WITH THE RELATIVELY
SPEAKING WARM START...SUNSHINE AND 925MB TEMPS AROUND 6C WHICH ARE
SIMILAR TO YESTERDAY...ANTICIPATING HIGHS TO BE FAIRLY SIMILAR TO A
FEW DEGREES WARMER THAN YESTERDAY. FOR TONIGHT...THE 850MB MOISTURE
STREAM CURRENTLY OVER WESTERN MINNESOTA AND IOWA WILL GET PUSHED
EAST INTO THE FORECAST AREA BY THE SHORTWAVE. THE MAIN QUESTION IS
IF DPVA AND ISENTROPIC LIFT AHEAD OF THIS SHORTWAVE WILL BE STRONG
ENOUGH TO ACT ON THIS MOISTURE AND PRODUCE PRECIPITATION. MID CLOUD
DEVELOPMENT IS A CERTAINTY...GIVEN WHAT HAPPENED LAST EVENING ON
THE LEADING EDGE OF THE 850MB MOISTURE STREAM. THE 18.00Z
NAM/REGIONAL CANADIAN PAINT A DRY PICTURE AND EVEN THE GFS WHICH
LOOKS TO HAVE A BIT TOO MUCH MOISTURE COMPARED TO ALL OTHER MODELS
PRODUCES LITTLE IF ANY PRECIPITATION BEFORE 12Z. THE 17.12Z ECMWF
MEANWHILE REMAINS MOST ROBUST WITH 0.1-0.2 OF AN INCH OVER NORTHEAST
IOWA BETWEEN 06-12Z MONDAY. NEW 18.00Z ECMWF IS SLIGHTLY DRIER. SREF
TRENDS HAVE SHOWN LESS MEMBERS PRODUCING 0.01 OF AN INCH OVER THE
LAST 5 RUNS...DOWN FROM 40-50 PERCENT TO 10-30 PERCENT. AT THIS
POINT...CANNOT SEE GOING WITH THE MORE ROBUST ECMWF SOLUTION AND
HAVE KEPT CHANCES LOW IN THE 20-30 PERCENT RANGE...CENTERED IN THE
09-12Z PERIOD. WITH THE INCREASING CLOUDS AND A SOUTHERLY BREEZE
BEING MAINTAINED...A SLIGHTLY WARMER NIGHT THAN TONIGHT IS
ANTICIPATED.
MONDAY AND MONDAY NIGHT...THE SHORTWAVE OVER WESTERN PORTIONS OF THE
FORECAST AREA AT 12Z LOOKS TO MOVE THROUGH THE REST OF THE FORECAST
AREA BY EARLY AFTERNOON...WHILE THE TAIL END OF THE DEEP TROUGHING
IN THE PACIFIC NORTHWEST IS PROGGED TO DROP DOWN INTO THE FORECAST
AREA AFTER MIDNIGHT MONDAY NIGHT. THIS LATTER SHORTWAVE WILL COME
THROUGH DRY SINCE THE SHORTWAVE COMING THROUGH MONDAY MORNING ENDS
UP SCOURING OUT A LOT OF THE MOISTURE. THUS ALL FOCUS IS ON THE
MONDAY MORNING PERIOD. AGAIN HERE...MODELS ARE AT ODDS WITH FORCING
AND MOISTURE AVAILABILITY. THE 18.00Z NAM/REGIONAL CANADIAN SAYS
THERE IS TOO MUCH DRY AIR BELOW 800MB AND THE FORCING IS TOO WEAK
ABOVE IT TO ALLOW FOR PRECIPITATION TO MAKE IT TO THE SURFACE. ON
THE OTHER HAND...THE 18.00Z GFS AND 17.12Z/18.00Z ECMWF ARE MORE
ROBUST IN BOTH ARENAS AND END UP PRODUCING LIGHT QPF ACROSS MUCH OF
THE AREA. SREF TRENDS FOR THE FULL DAY MONDAY ARE ALSO SIMILAR TO
06-12Z MONDAY...SHOWING A DECLINE OF MEMBERS PRODUCING AT LEAST 0.01
OF AN INCH. IT USED TO BE UP AT 70-80 PERCENT BUT NOW IS DOWN TO
30-60 PERCENT. THUS...CONFIDENCE REMAINS TOO LOW TO ADJUST THE
PREVIOUS FORECAST PRECIPITATION CHANCES OF 20-40 PERCENT. CERTAINLY
IF ANY PRECIPITATION OCCURS...ANY RAIN LOOKS REALLY LIGHT. REGARDING
CLOUD COVER...IT NOW APPEARS THAT THE SHORTWAVE ON MONDAY MORNING
SHOULD HELP TO CLEAR THE CLOUDS OUT AS IT MOVES AWAY DURING THE
AFTERNOON. THERE MAY BE AN INCREASE OF CIRRUS WITH THE SHORTWAVE
COMING IN MONDAY NIGHT...BUT THATS ABOUT IT. NOTE THAT THERE IS
CONCERN FOR A LOW CLOUD DECK BASED ON THE GFS/ECMWF 925MB RH
PROGS...BUT THEY MAY BE TOO MOIST. FOR NOW TAKING A COMPROMISE
APPROACH BY SPEEDING UP THE CLEARING SOME FROM THE PREVIOUS
FORECAST. HAVING MORE CLOUDS MONDAY WILL HOLD THE TEMPERATURES DOWN
A FEW DEGREES FROM HIGHS OVER THE WEEKEND. A COOLER NIGHT SEEMS
LIKELY TOO FOR MONDAY NIGHT...ESPECIALLY IF THE CLEARING OCCURS.
TUESDAY AND TUESDAY NIGHT...IN THE WAKE OF THAT SHORTWAVE DROPPING
INTO THE FORECAST AREA TUESDAY MORNING...SOME FAIRLY STRONG RIDGING
IS PROGGED TO BUILD INTO THE FORECAST AREA BY TUESDAY EVENING. ABOUT
ALL THAT SHORTWAVE IS GOING TO DO IS PREVENT THE 850MB TEMP
CLIMB...NOTED BY 850MB TEMPS AT 18Z TUESDAY OF 5-7C. ONCE THE
RIDGING STARTS BUILDING IN...THESE TEMPS CLIMB...TOPPING OUT AT 8C
EAST TO 11C WEST BY 12Z WEDNESDAY. WITH WHAT SHOULD BE PLENTY OF
SUN...HIGHS SHOULD BE ABLE TO TOP OUT IN THE 50S AGAIN ON TUESDAY
GIVEN THE AFOREMENTIONED 850MB TEMPS. INCREASING SOUTHERLY FLOW
TUESDAY NIGHT IN THE WAKE OF HIGH PRESSURE THAT CROSSES THE AREA ON
TUESDAY WILL HELP TO KEEP TEMPERATURES UP IN SOUTHEAST MINNESOTA.
FOLLOWED A BLEND OF GUIDANCE FOR LOWS.
.LONG TERM...WEDNESDAY THROUGH SATURDAY NIGHT
212 AM CST SUN NOV 18 2012
MAIN FOCUS CONTINUES TO BE ON A POTENT SHORTWAVE TROUGH ENTERING THE
PACIFIC NORTHWEST WEDNESDAY MORNING. MODEL AGREEMENT HANDLING THIS
POTENT TROUGH BEGINS TO DECLINE AS EARLY AS 12Z THURSDAY...WITH THE
18.00Z ECMWF/CANADIAN SHOWING A DIGGING NATURE TO IT INTO THE
NORTHERN PLAINS. MEANWHILE...THE 18.00Z GFS TAKES A MORE PROGRESSIVE
APPROACH AND SENDS IT UP INTO NORTHERN ONTARIO ON THURSDAY. BOTH THE
GFS AND ECMWF HAVE COMPLETELY FLIPPED FROM PREVIOUS RUNS WITH THE
HANDLING OF THIS POTENT TROUGH. THE 18.00Z ECMWF LOOKS MORE LIKE THE
17.00Z GFS WHILE THE 18.00Z GFS LOOKS MORE LIKE THE 16.12Z ECMWF.
THIS HAS SIGNIFICANT IMPLICATIONS ON THE TEMPERATURE AND WIND
FORECASTS...PRIMARILY FRIDAY AND BEYOND. WITH THE MORE DIGGING
NATURE OF THE ECMWF/CANADIAN...THEY END UP CARVING OUT A DEEP TROUGH
ACROSS THE WESTERN GREAT LAKES REGION FOR FRIDAY...THOUGH WITHIN
THIS GROUP THE CANADIAN IS MORE PROGRESSIVE. WHICHEVER MODEL
SCENARIO PLAYS OUT...IT APPEARS DRY WEATHER WOULD BE THE RULE WITH
THE BEST JUXTAPOSITION OF FORCING AND MOISTURE EITHER NORTH OR
SOUTHEAST OF THE AREA. GIVEN THE DIFFERENCES EARLY IN THE LONG TERM
PERIOD...HARD TO SAY HOW THE WEEKEND WILL PLAY ITSELF OUT. NOTE THAT
THE 18.00Z GFS ENSEMBLES HAVE A PRETTY GOOD SPREAD TOO WITH REGARDS
TO THE POTENT TROUGH. THUS FOR NOW HAVE STAYED WITH A CONSENSUS
APPROACH WHEN IT COMES TO THE WEEKEND...YIELDING COOLER AND A
CONTINUATION OF DRY CONDITIONS.
REGARDING TEMPERATURES...WEDNESDAY AND THANKSGIVING DAY STILL LOOK
WELL ABOVE NORMAL...ESPECIALLY WEDNESDAY AS 925MB TEMPS CLIMB TO
10-12C FOR 18Z. MIXING TO 925MB YIELDS HIGHS FROM THE UPPER 50S TO
MIDDLE 60S...THUS HAVE BOOSTED HIGHS A FEW DEGREES. RECORD HIGHS FOR
WEDNESDAY ARE 72 AT LA CROSSE AND 69 AT ROCHESTER...STILL 5-10
DEGREES ABOVE THE GOING FORECAST. NOTE THAT 850MB TEMP
STANDARDIZED ANOMALIES HAVE NOW JUMPED TO NEAR 2...SUPPORTING THE
INCREASING IN HIGH TEMPERATURES. SOME COOLING IN 925MB TEMPS
TAKES PLACE ON THANKSGIVING DAY AS A COLD FRONT MOVES INTO THE
REGION. STILL...MOST LOCATIONS SHOULD TOP OUT AT LEAST IN THE MID
TO UPPER 50S...MAYBE EVEN 60 AT SOME SOUTH OF I-90. RECORD HIGH
FOR THURSDAY IS 59 AT LA CROSSE AND 65 AT ROCHESTER...THUS LA
CROSSE MAY BE DOABLE TO BREAK. TEMPERATURES SHOULD RETURN CLOSER
TO NORMAL FOR FRIDAY INTO THE WEEKEND IN THE WAKE OF THE COLD
FRONT. IF THE 18.00Z ECMWF IS CORRECT...WE COULD EVEN BE BELOW
NORMAL FOR THE WEEKEND.
&&
.AVIATION...
1115 PM CST SAT NOV 17 2012
AN UPPER LEVEL DISTURBANCE WAS SPINNING ACROSS NORTHERN PARTS OF THE
REGION TONIGHT...RESULTING IN SOME MID/HIGH LEVEL CLOUDINESS. CIGS
WERE MOSTLY 6-10 10 KFT...AND EXPECT THEM TO CLEAR AROUND 15Z OR
SO SUN WITH THE EXIT OF THE SHORTWAVE. MORE MID/HIGH LEVEL CIGS WILL
RETURN SUNDAY NIGHT AS ANOTHER SHORTWAVE APPROACHES FROM THE
SOUTHERN PLAINS. THIS SYSTEM COULD PRODUCE SOME LIGHT PCPN
CHANCES...WITH THE BETTER CHANCES COMING AFTER 06Z MONDAY.
WINDS WILL STAY UP TONIGHT AS THE TIGHT PRESSURE GRADIENT
REMAINS...AND SUN AFTERNOON SHOULD BE FAIRLY SIMILAR TO SAT
AFTERNOON. EXPECT MIXING TO RESULT IN AFTERNOON GUSTINESS...CLOSE TO
25 KTS AT KRST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
212 AM CST SUN NOV 18 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
824 AM CST SUN NOV 18 2012
.DISCUSSION...
321 AM CST
SYNOPSIS...SOME THINGS BECOME CLEARER WHILE OTHER PARTS OF THE
FORECAST BECOME MORE MUDDLED. OVERALL A GRADUAL WARMING PATTERN IS
STILL EXPECTED THROUGH MONDAY...WITH TEMPERATURES WELL ABOVE NORMAL
WEDNESDAY AND THANKSGIVING. NO SIGNIFICANT PRECIP IS EXPECTED.
TODAY THROUGH MONDAY...
HIGH PRESSURE CURRENTLY CENTERED OVER SOUTHEASTERN QUEBEC/UPPER NEW
ENGLAND STRETCHES THROUGH THE MISSISSIPPI RIVER VALLEY. THE HIGH
WILL REMAINED CENTERED THERE THROUGH EARLY NEXT WEEK WITH RELATIVELY
QUIET WEATHER EXPECTED LOCALLY. TEMPS WILL BE AROUND 60 TODAY WITH
CLEAR SKIES AND SOUTHERLY FLOW.
CLOUDS INCREASE TOMORROW AS A THROUGH OF LOW PRESSURE/WEAK COLD
FRONT APPROACH FROM THE WEST. AS SUCH WENT WITH TEMPS A DEGREE OR
TWO COOLER ON MONDAY...BUT STILL WELL ABOVE AVERAGE.
MONDAY NIGHT AND TUESDAY...
LOW PRESSURE CURRENTLY OVER WESTERN BRITISH COLUMBIA WILL PUSH
EASTWARD THROUGH CANADA...AND MODELS CONTINUE TO PUSH THE LOW
FURTHER NORTH. THE LOWS COLD FRONT/LOW PRESSURE TROUGH WILL PASS
THROUGH THE AREA. FORCING REMAINS WEAK ALONG THE COLD FRONT
THEREFORE EXPECTING A FEW HUNDREDTHS AT BEST MONDAY EVENING THROUGH
MONDAY NIGHT. GUIDANCE INDICATES THE TROUGH/COLD FRONT WEAKENS AS
IT APPROACHES THE CWA SO THE BEST CHANCE OF PRECIP LOOKS TO BE
OVER THE WESTERN AND NORTHERN PORTIONS OF THE CWA MONDAY NIGHT.
AND BY BEST CHANCE I MEAN BEST VERY VERY SLIGHT CHANCE.
PRECIP MOVES OUT BY TUESDAY MORNING AND HIGH PRESSURE QUICKLY MOVES
OVER THE CWA. THINKING TEMPS WILL ONCE AGAIN BE A DEGREE OR TWO
HIGHER THAN MONDAY DUE TO WEAK UPPER LEVEL WAA AND CLEARING SKIES.
WEDNESDAY AND THANKSGIVING...
SOUTHERLY FLOW RETURNS IN FORCE WEDNESDAY AS THE HIGH PRESSURE
SLIDES TOWARD THE SOUTHEAST US. 850 HPA TEMPS SOAR TO AROUND 10C
WEDNESDAY AND THANKSGIVING...THEREFORE WENT A FEW DEGREES ABOVE
ALL-BLEND GUIDANCE ONCE AGAIN. ITS LOOKING LIKE THURSDAY MAY BE THE
WARMER OF THE TWO DAYS WITH TEMPS BOTH DAYS AT OR ABOVE 60 DEGREES.
MOST PEOPLE WOULD AGREE THAT IS SOMETHING TO BE THANKFUL ABOUT.
EXTENDED...THANKSGIVING NIGHT THROUGH SATURDAY...
WHAT HAPPENS THANKSGIVING EVENING/NIGHT IS THE BIG FORECAST
QUESTION. THE GEM AND ECMWF INDICATE LOW PRESSURE WILL MOVE FROM
THE CENTRAL PLAINS THROUGH WISCONSIN WITH ITS COLD FRONT MOVING
THROUGH THE CWA THANKSGIVING NIGHT. THE GFS ON THE OTHER HAND HAS
THE LOW MOVING MUCH FARTHER NORTH OVER CENTRAL ONTARIO AND QUEBEC.
THE GFS SOLUTION IS ALSO MUCH FASTER THAN THE OTHER TWO SOLUTIONS.
SINCE THE GEM AND ECMWF ARE MERGING TOWARD EACH OTHER...LEANING
TOWARD THAT SOLUTION. THERE ARE ENOUGH DIFFERENCES IN THE SOLUTIONS
THAT DECIDED TO NOT MAKE ANY ADJUSTMENTS TO THE ALL-BLEND TEMPS OR
SLIGHT CHANCE POP FORECAST.
THAT BEING SAID...IF THE ECMWF SOLUTION IS TO BE BELIEVED...A
SIGNIFICANT TEMPERATURE DROP WILL BE EXPECTED BETWEEN THANKSGIVING
AND FRIDAY. BY FRIDAY AFTERNOON 850 HPA TEMPS ARE WELL BELOW ZERO.
THE GFS FEATURES A MUCH WEAKER COLD AIR PUSH SINCE ITS UPPER LEVEL
PATTERN IS VERY ZONAL. NONETHELESS IT DOES FEATURE 850 HPA TEMPS
BELOW ZERO MOVING OVERHEAD SATURDAY.
JEE
&&
.CLIMATE...
321 AM CST
A SHIFT IN THE UPPER PATTERN WILL ALLOW SOME MODERATION OF
TEMPERATURES GOING INTO THE WEEKEND AND PREVAILING FOR SEVERAL DAYS
THEREAFTER. WHILE THE MODERATION WILL HELP OBSERVED TEMPERATURES TO
EXCEED DAILY NORMALS THE FACT THAT INCREASINGLY SHORTER DAYS AND
LOWERING SUN ANGLES RESULT IN THE NORMAL HIGH TEMPERATURE FALLING BY
1 DEGREE F ABOUT EVERY 2 DAYS. SO...IT IS THE COMBINATION OF THE
LOWERING NORMAL MAXIMUM TEMPERATURES ALONG WITH THE WARMING THAT
WILL RESULT IN DAYTIME TEMPERATURES TO CLIMB TO ABOVE NORMAL...WHICH
ARE NOW ONLY IN THE UPPER 40S AT MID NOVEMBER.
NORMALS...
CHICAGO ROCKFORD
MAX MIN MAX MIN
NOV 01 56 38 56 36
NOV 17 47 32 47 30
NOV 30 40 27 39 24
THIS UNUSUAL PATTERN WILL ALSO ALLOW HIGH TEMPERATURES ON
WEDNESDAY AND THURSDAY...THANSKGIVING...TO COME CLOSE TO THE
RECORD HIGH TEMPERATURES. WHILE FORECASTED HIGH TEMPERATURES ARE
CURRENTLY A FEW DEGREES COOLER THAN THE RECORDS...HERE ARE THE THE
MAX TEMPERATURE RECORDS FOR FOOD FOR THOUGHT:
CHICAGO ROCKFORD
NOV 21 72 1913 73 1913
NOV 22 69 1913 69 2010
TRS/JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* LAKE BREEZE MOVING INLAND TO MDW AND ORD VC 21-22Z TIME-FRAME.
TRS
//DISCUSSION...UPDATED 14Z...
LATEST RUC AND HRR MODEL OUTPUT SUGGESTING A WEAK LAKE BREEZE...
SUCH AS OCCURRED FRI AND SAT...DEVELOPING AND MOVING INLAND TO
MDW AND ORD VC 21-22Z TIME-FRAME. WINDS EXPECTED TO BECOME A BIT
MORE SOUTHERLY LATE MORNING AND EARLY AFTERNOON AND THE BACKING
TO SE-ESE THERE TERMINALS FOR LATE AFTERNOON INTO EARLY EVE.
TRS
PREVIOUS...UPDATED 12Z...
HIGH PRESSURE PARKED OVER THE EASTERN UNITED STATES WILL MAINTAIN
HIGH CLOUDS AND RELATIVELY LIGHT SOUTH TO SOUTHEASTERLY WINDS OVER
THE LOCAL TERMINALS. ALTHOUGH LATEST ASOS OBS AT ISSUANCE TIME
WERE SHOWING CALM WINDS...OPTED TO KEEP A SSE DIRECTION AND 5 KTS
IN THE TAFS TO HELP CRAFT A PLAN TO START OF THE DAY. THIS ALSO
MATCHES THE WINDS REPORTED ELSEWHERE AROUND ORD AS RELAYED BY THE
CWSU. DID NOT ATTEMPT TO PIN DOWN GUSTS OR MINOR VARIATIONS IN
DIRECTION THAT COULD OCCUR THROUGHOUT THE DAY...THOUGH THERE IS A
CHANCE THAT WINDS COULD TURN FARTHER TO THE EAST IN RESPONSE TO A
LAKE BREEZE INFLUENCE.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH CONFIDENCE IN VSBYS STAYING WELL ABOVE IFR...BUT BRIEF
REDUCTIONS DUE TO HAZE ARE POSSIBLE THROUGH SUNRISE.
* MEDIUM TO HIGH CONFIDENCE ON WIND TRENDS TODAY AND THIS EVENING.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...VFR WITH SLIGHT CHANCE OF LIGHT RAIN.
TUESDAY AND WEDNESDAY...VFR.
THANKSGIVING...VFR WITH A CHANCE OF SHOWERS LATE.
FRIDAY AND SATURDAY...VFR.
LENNING
&&
.MARINE...
249 AM CST
A BROAD RIDGE ACROSS THE NORTHEASTERN UNITED STATES WILL WEAKEN
SOMEWHAT BUT MOVE VERY LITTLE THROUGH THE FIRST HALF OF THE WEEK.
THE LOCATION OF THIS FEATURE WILL SUPPORT CONTINUED SOUTHERLY FLOW
ACROSS THE LAKE. THE LACK OF A STRONG PRESSURE GRADIENT WILL
GENERALLY KEEP WINDS AND WAVES BELOW LEVELS THAT WOULD POSE
HAZARDS. THE EXCEPTION WOULD BE ALONG THE FAR NORTHERN SHORE AT
THE END OF THE LONG FETCH WHERE SMALL CRAFT HEADLINES ARE IN
EFFECT. EVEN THE APPROACH OF A TROUGH FROM THE WEST TOWARD MIDWEEK
WILL NOT BE ENOUGH TO BOOST WINDS...SINCE BY THAT TIME THE RIDGE
TO THE EAST WILL HAVE WEAKENED SOMEWHAT AND MOVED A BIT FARTHER
AWAY TOWARD THE ATLANTIC COAST.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
428 AM MST SUN NOV 18 2012
.UPDATE...
ISSUED AT 428 AM MST SUN NOV 18 2012
THOUGH MID LEVEL CLOUDS HAVE OCCASIONALLY MOVED ACROSS THE AREA
EARLY THIS MORNING...LOW TEMPERATURES AT KITR/KMCK DROPPED INTO
THE MID 20S. ADJUSTED THE SHORT TERM GRIDS TO REFLECT THE COOLER
TEMPERATURES. TRIBUNE REPORTED SOME LIGHT FOG EARLIER THIS
MORNING...AND THE LATEST HRRR CONTINUES TO DEVELOP FOG ACROSS
SHERMAN AND THOMAS COUNTIES AFTER SUNRISE. WILL KEEP FOG MENTIONED
IN THE FORECASTS FOR A FEW MORE HOURS.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 145 AM MST SUN NOV 18 2012
SUMMARY...DRY WEATHER WITH ABOVE NORMAL TEMPERATURES WILL CONTINUE
THROUGH THE SHORT TERM PART OF FORECAST.
TODAY...DEW POINT DEPRESSIONS CONTINUE TO LOWER EARLY THIS MORNING.
LATEST FOG PRODUCT SATELLITE IMAGERY DOES NOT SHOW ANY EVIDENCE OF
FOG FORMATION YET...BUT WITH LIGHT SURFACE WINDS...EXPECT SOME
PATCHY FOG TO DEVELOP SHORTLY BEFORE SUNRISE MAINLY ALONG HIGHWAY
83. LATEST HRRR MODEL SUPPORTS THIS. OTHERWISE...A WEAK SHORTWAVE
TROUGH WILL MOVE ACROSS THE FORECAST AREA DURING THE DAY...BUT
RAOBS/MODELS CONTINUE TO SHOW THAT THE AIR MASS WILL BE DRY. ONLY
MID AND HIGH LEVEL CLOUDS WILL ADVECT ACROSS THE AREA THIS AFTERNOON.
LEE SIDE SURFACE TROUGH WILL MOVE EAST THIS AFTERNOON AND WILL
SWITCH WINDS TO THE WEST ALONG THE COLORADO/KANSAS BORDER. WITH
LACK OF AIR MASS CHANGE...EXPECT TEMPERATURES TO BE SIMILAR TO
THOSE THAT OCCURRED SATURDAY.
TONIGHT...500 MB FLOW BECOMES INCREASINGLY ZONAL BEGINNING TONIGHT.
MODELS SHOW WEAK COLD AIR ADVECTION AT THE SURFACE STARTING AROUND
12Z.
MONDAY...DRY ZONAL MID LEVEL FLOW WILL CONTINUE. SURFACE WINDS WILL
BE NORTH BEHIND A PUSH OF SLIGHTLY COOLER AIR. ALTHOUGH 850 MB
TEMPERATURES COOL...THE COOLING IS VERY SLIGHT...ONLY ABOUT 1 DEGREE
CELSIUS. ONCE AGAIN...PERSISTENCE TEMPERATURE FORECASTS LOOK DECENT.
MONDAY NIGHT THROUGH TUESDAY NIGHT...500 MB RIDGE AND ASSOCIATED
SUBSIDENCE WILL DEVELOP OVER THE HIGH PLAINS. LEE SIDE TROUGH WILL
REFORM BY TUESDAY AFTERNOON BRINGING A RETURN OF SOUTH WINDS AND WEAK
WARM AIR ADVECTION.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 145 AM MST SUN NOV 18 2012
VERY LITTLE HAS CHANGED IN THE EXTENDED PERIODS WITH MODELS STILL
ADVERTISING PROGRESSIVE ZONAL PATTERN WITH MAIN STORM TRACK ALONG
US/CANADA BORDER. THERE ARE A FEW WEAK SHORTWAVE TROUGHS THAT COME
CLOSE TO THE CWA...HOWEVER WITH A DEEP DRY LAYER IN PLACE THE MOST
WE WOULD EXPECT TO SEE IS AN INCREASE IN MID-HIGH CLOUDS. RH VALUES
STILL LOOK TO BE NEAR RFW CRITERIA WEDNESDAY AFTERNOON...HOWEVER
SURFACE GRADIENT IS WEAK OVER THE CWA AND WINDS SHOULD BE WELL BELOW
CRITERIA.
OVERALL...STILL EXPECTING ABOVE NORMAL TEMPERATURES AND DRY CONDITIONS
TO CONTINUE. WED HIGHS WILL APPROACH 70F...WITH HIGHS IN THE UPPER
50S/NEAR 60F THROUGH THE REMAINING PERIODS AFTER A WEAK COLD FRONT
MOVES THROUGH THE REGION WED NIGHT/THU. OVERNIGHT LOWS SHOULD BE IN
THE LOW TO MID 30S EACH NIGHT...WHICH IS IS STILL ABOUT 10F ABOVE NORMAL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 428 AM MST SUN NOV 18 2012
THE MAIN ISSUE WITH THIS FORECAST IS WHETHER FOG WILL FORM FROM
12-15Z. THE LATEST HRRR BRINGS LOWER VISIBILITIES TO KGLD...BUT
NOT TO KMCK. SATELLITE IMAGERGY CONTINUES TO SHOW NO EVIDENCE OF
FOG. GIVEN DEW POINT DEPRESSIONS OF 2-3 DEGREES AND LITTLE
WIND...WILL KEEP MENTION OF FOG WITH VISIBILITIES AROUND THREE
MILES AT KGLD. WILL KEEP KMCK FREE OF ANY FOG. REGARDLESS...BOTH
SITES WILL BE VFR AFTER 16Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...MENTZER
SHORT TERM...MENTZER
LONG TERM...DR
AVIATION...MENTZER
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
823 AM EST SUN NOV 18 2012
.SYNOPSIS...
HIGH PRESSURE WILL MAINTAIN DRY WEATHER AND SEASONAL TEMPERATURES ACROSS
THE REGION THROUGH THANKSGIVING.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ANOTHER COOL START TO THE MORNING...BUT TEMPERATURES WILL REBOUND
NICELY THIS AFTERNOON DUE TO WAA AND KATABATIC WINDS. RIDGES ARE
ALREADY MIXED EVIDENT BY LBE IN THE LOWER 40S AS OF 13Z. LOWER
ELEVATIONS WILL CATCH UP BY LATE MORNING AS A MCLR SKY IS AGAIN
PREDICTED. BUMPED MAXT TEMPS UP A CATEGORY...DUE TO A POSITIVE H8
24HR DELTA OF 2-3 AND MODEST SE WIND TRAJECTORY. HRRR DID AN
EXCELLENT JOB ON MAXT YDY...SO FOLLOWED IT TODAY...BUT SHAVED A
DEGREE OR TWO OFF THE LOWLANDS IMMEDIATELY ADJACENT TO THE MTNS.
THAT SAID...LOOK FOR UPPER 50S TO LOWER 60S TO BE COMMON THIS
AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
VERY LITTLE CHANGE IN THE PATTERN UNTIL LATE TUESDAY/WEDNESDAY...
WHEN A SHORTWAVE TROUGH WILL SWING THROUGH THE OHIO VALLEY. WILL
CONTINUE WITH A DRY FORECAST, AS UPPER LEVEL SUPPORT IS WEAK AND
DEEP MOISTURE IS LACKING. THE MAIN EFFECT FROM THE FEATURE WILL BE
AN INCREASE IN CLOUDS TUE NIGHT/WED MORNING.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...
- MEDIUM TO HIGH CONFIDENCE
- NO BIG STORMS OVER THE LONG HOLIDAY WEEKEND
- NEAR NORMAL TEMPERATURES
- FOLLOWED ECMWF
EXTENDED FORECAST REMAINS RATHER UNEVENTFUL WHICH IS GOOD GIVEN THE
TIME OF YEAR AND THE LARGE NUMBER OF PEOPLE OUT TRAVELING FOR THE
UPCOMING HOLIDAY WEEKEND. A TRANSITORY H5 ANTI-CYCLONE ALLOWS A
SUNNY AND MILD TURKEY DAY. THE NEXT SYNOPTIC FEATURE WILL BE A
WEAK BAROCLINIC ZONE THE SECOND HALF OF FRIDAY. AGAIN...NOT MUCH
IN THE WAY OF MOISTURE WITH THIS SYSTEM SO EXPECT MINIMAL QPF AT
BEST. NW FLOW RESULTING FROM FAIRLY SIGNIFICANT HEIGHT FALLS OVER
NEW ENGLAND ALLOW FOR LAKE EFFECT RW/SW TO DEVELOP SAT. H8 TEMPS
AT THIS TIME ARE PROGGED IN THE -8 TO -10C RANGE...BUT DUE TO LESS
THAN OPTIMAL INVERSION HEIGHTS...LITTLE ACCUMULATION IS PROJECTED
SATURDAY.
&&
.AVIATION /13Z SUNDAY THROUGH THURSDAY/...
HIGH PRES WL MAINTAIN VFR WEATHER WITH A CLEAR SKY AND LGT WND THROUGH
TODAY.
.OUTLOOK.../TONIGHT THROUGH THURSDAY/...
NO WIDESPREAD RESTRICTION AREAS ARE EXPECTED THIS WEEK ALTHOUGH A
CROSSING DISTURBANCE MAY SPAWN SOME LGT SHOWERS AND MID LVL CLDS ON
TUESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
NEAR TERM...98
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
301 AM MST SUN NOV 18 2012
.DISCUSSION...
CURRENTLY...JET FLOW MOVING FROM SOUTHWEST TO NORTHEAST ACROSS THE
HEART OF NEW MEXICO...WITH CLINIC IN INERTIAL INSTABILITY ON IR
IMAGERY SHOWING COLDEST CLOUD TOPS ON THE NORTH EDGE OF THE
FLOW...WITH WARMER TOPS TO THE SOUTH AND EAST. DESPITE IMPRESSIVE
SATELLITE DISPLAY...PRECIPITATION HAS BEEN MODEST UPSTREAM...AS
DRY AIR MASS AT THE SURFACE IS EVAPORATING MUCH OF WHAT WOULD BE
FALLING BEFORE IT HITS THE GROUND. DOME OF HIGH PRESSURE SITTING
OVER WESTERN COLORADO WORKING WITH SURFACE TROUGH EXTENDING FROM
SOUTHEAST COLORADO ACROSS EASTERN NEW MEXICO TO THE TEXAS BIG BEND
COUNTRY...AND THIS MIGHT PERMIT SOME LOW LEVEL STRATUS PENETRATION
DRIFTING OUT OF TEXAS AND INTO EASTERN NEW MEXICO HEADING TOWARD
SUNRISE.
MODELS...IN REASONABLE AGREEMENT THROUGH THE THANKSGIVING HOLIDAY
WEEKEND...WITH SOME SIGNIFICANT DIFFERENCES IN PATTERN EVOLUTION
AS THE FOLLOWING WORK WEEK GETS STARTED. GOOD CONSENSUS HAS
SOUTHWEST FLOW IN CIRCULATION ABOUT NEW GULF OF ALASKA CLOSED LOW
CIRCULATING SHORT WAVES AGAINST THE CALIFORNIA COAST THROUGH THE
DAY TODAY AND INTO TONIGHT...WITH THESE WAVES PROPAGATING QUICKLY
EASTWARD ACROSS NEW MEXICO. WAVE INTENSITY DIMINISHING SHARPLY BY
MONDAY MORNING...AS FLOW ALOFT RESETS TO ZONAL...AND BAGGY TROUGH
BUILDS FROM SOUTHERN CALIFORNIA SOUTHWARD ACROSS THE TROPICAL EAST
PACIFIC ALONG THE BAJA PENINSULA. AS GULF OF ALASKA CLOSED LOW
SHIFTS TO THE QUEEN CHARLOTTE ISLANDS OFF THE BRITISH COLUMBIA
COAST TUESDAY...RIDGE WILL BUILD OUT OF CENTRAL MEXICO NORTHWARD
ACROSS NEW MEXICO AND INTO THE NORTHERN PLAINS...AS EAST PACIFIC
TROUGH BEGINS SHEAR TO THE EAST ACROSS ARIZONA...AND THROUGH NEW
MEXICO ON WEDNESDAY. WITH TROUGH EXITING TO THE CENTRAL PLAINS ON
THANKSGIVING...WINDS ALOFT WILL DECREASE OVER NEW MEXICO...AND
RIDGING BUILDS NORTHWARD OUT OF CHIHUAHUA ACROSS NEW MEXICO TO THE
SNAKE RIVER VALLEY OF IDAHO AND THE BITTERROOT RANGE OF WESTERN
MONTANA. RIDGE WILL START EASTWARD DRIFT ON SATURDAY WITH NEXT
TROUGH DEEPENING ON THE WEST COAST AND STARTING SLOW TREK EAST
THROUGH SUNDAY. MODELS PART WAYS ON MONDAY...AS DOMESTIC GFS
BUILDS AMPLIFYING RIDGE NORTHWARD OVER THE EAST PACIFIC TO PLACE
NEW MEXICO IN NORTHWEST FLOW FOR THE FIRST HALF OF THE WORK WEEK.
EUROPEAN COLLEAGUES AT ECMWF DIG AMPLIFYING AND MUSCULAR TROUGH
OVER THE WESTERN U.S...PLACING NEW MEXICO IN INTENSIFYING SOUTHWEST
FLOW IN CIRCULATION ABOUT CLOSED LOW OVER SOUTHWEST CANADA. WILL
CONCUR WITH HPC COLLEAGUES WHO POINT OUT GFS TENDENCY TO BE A
LITTLE TOO QUICK WITH THIS KIND OF PATTERN...AND WILL LEAN THE
FIRST OF THE WORK WEEK TOWARD ECMWF FOR NOW.
FOR TODAY...BROAD CLOUDINESS ACROSS NEW MEXICO AS PACIFIC MOISTURE
IS SHOVED NORTHWARD AND EASTWARD FROM THE CALIFORNIA COAST IN
SOUTHWEST FLOW ALOFT AND AT THE SURFACE. BROAD SHOWER COVERAGE ACROSS
WESTERN AND SOUTHERN NEW MEXICO...WITH INCREASED SHOWER COVERAGE
AND INTENSITY MAINLY SOUTH OF A LINE FORM ROSWELL TO CLOVIS NEAR
THE LEA AND EDDY COUNTY LINES. UP NORTH...A FEW SPOTTY SHOWERS MAY
DUST THE SAN JUAN MOUNTAIN PEAKS WITH SNOW NEAR THE COLORADO
LINE...WITH LIGHT RAIN MOSTLY OVER SLOPES AND VALLEYS. DEEPENING
SURFACE TROUGH FROM EASTERN COLORADO TO THE TEXAS BIG BEND COUNTRY
WILL HELP PRODUCE SOME SOUTHWEST BREEZES IN SPOTS OVER THE EASTERN
PLAINS THIS AFTERNOON. SOME COOLER AIR FILTERING IN FROM THE NORTH
WILL TAKE THE EDGE OFF AFTERNOON TEMPERATURES OVER THE NORTHERN
TIER...WITH WARMING TREND CONTINUING ELSEWHERE. EASTERN PLAINS
TEMPERATURES WILL RUN 5 TO 10 DEGREES ABOVE NORMAL...WITH NEAR
NORMAL TEMPERATURES IN THE EAST.
FOR MONDAY...ZONAL FLOW BECOMING ESTABLISHED OVER THE STATE AS
NEXT WEST COAST SYSTEM WITH IMPRESSIVE CIRCULATION DRIFTS OUT OF
THE GULF OF ALASKA ALONG THE WEST COAST OF CANADA. SOMEWHAT COOLER
AIR MASS IN PLACE OVER NEW MEXICO WILL WORK AGAINST CLEARING SKIES
AND INCREASES IN SUNSHINE TO KEEP DAYTIME MAXIMUM TEMPERATURES
STEADY. SURFACE LOW WILL SHIFT OUT OF EASTERN COLORADO TO THE
TEXAS PANHANDLE...ALLOWING LOW LEVEL WINDS TO SHIFT NORTHWEST AND
TAP AIR A FEW DEGREES COOLER THROUGH THE DAY. SOME NORTHWEST TO
WESTERLY BREEZES POSSIBLE MONDAY AFTERNOON OVER THE EASTERN SLOPES
AND ADJACENT PLAINS OF THE CENTRAL MOUNTAIN CHAIN.
FOR TUESDAY...RIDGING OVER NEW MEXICO AS BIG BAGGY TROUGH OVER THE
BAJA PENINSULA ATTEMPTS TO SHOVE SOME CLOUD AND MOISTURE OUT OF
CHIHUAHUA AND THE TEXAS BIG BEND COUNTRY INTO SOUTHEAST NEW
MEXICO. MOISTURE WILL BE SLOW IN COMING...AND MOST SHOULD STAY
SOUTH OF OUR FORECAST AREA THROUGH TUESDAY NIGHT. STRONG SOUTHERLY
COMPONENT TO SURFACE WINDS IN RETURN FLOW. TEMPERATURE TRENDS
REMAINING FAIRLY STEADY TUESDAY AFTERNOON...WITH A LITTLE WARMING
IN THE WEST OFFSET BY A DEGREE OR TWO OF COOLING IN THE EAST.
FOR WEDNESDAY...SHOWERS OVER SOUTHERN NEW MEXICO EXPANDING
NORTHWARD TO INTERSTATE 40 WEDNESDAY AFTERNOON...AND THEN SHIFTING
FOCUS TO THE SOUTHEAST PLAINS BY WEDNESDAY NIGHT. SOME SOUTHWEST
BREEZES OVER THE NORTHEAST PLAINS WEDNESDAY AFTERNOON...HELPED BY
DEEPENING SURFACE TROUGH FROM EASTERN COLORADO INTO NORTHEAST NEW
MEXICO. STEADY TEMPERATURE TRENDS CONTINUING.
OUTLOOK...THANKSGIVING DAY THROUGH SATURDAY...ZONAL FLOW BACK IN
PLAY FOR THANKSGIVING DAY UNDER SUNNY SKIES...AND THE LAST OF THE
ISOLATED SHOWERS MOVING OUT OF THE SOUTHEAST PLAINS INTO THE HEART
OF TEXAS...AND TEMPERATURES STEADY AND ABOVE NORMAL. SAME BASIC
STORY FOR FRIDAY. BAGGY TROUGH REDEVELOPING OVER NORTHWEST MEXICO
AND THE ADJACENT TROPICAL EAST PACIFIC ON SATURDAY...AS COLD FRONT
SAGS SOUTHWARD ACROSS THE EASTERN PLAINS AND TO THE MEXICO BORDER
ON SATURDAY. THIS WILL TAKE A FEW DEGREES OFF THE SATURDAY HIGH
TEMPERATURE...BUT TEMPERATURES WILL REMAIN 3 TO 8 DEGREES ABOVE
LATE NOVEMBER NORMALS.
SHY
&&
.FIRE WEATHER...
CLOUDS WILL CONTINUE TO STREAM FROM SOUTHWEST TO NORTHEAST ACROSS
THE DISTRICT TODAY. THE BEST CHANCES FOR SHOWERS WILL BE OVER THE
SOUTHERN THIRD OR SO OF NEW MEXICO WHERE THE DEEPEST MOISTURE AND
STRONGEST ATMOSPHERIC LIFT ARE CO-LOCATED. AS THE WEAK UPPER LEVEL
PACIFIC TROUGH RESPONSIBLE FOR THE CLOUDS AND SHOWERS OVER SOUTHERN
AND CENTRAL NM EJECTS EAST-NORTHEAST THIS AFTERNOON...VERY DRY AIR
IN THE MID LEVELS OF THE ATMOSPHERE WILL MOVE IN FROM THE
WEST-SOUTHWEST AND BRING A GRADUAL END TO THE SHOWERS. SLIGHTLY
COOLER AIR WILL FILTER INTO THE NORTHWEST HALF OF NM THIS AFTERNOON.
AS THE COOLER AIR FILTERS IN FROM THE NORTHWEST AND HIGHER DEW POINT
LEVELS REMAIN IN PLACE.... VERY GOOD TO EXCELLENT HUMIDITY
RECOVERIES ARE EXPECTED OVERNIGHT. THE ONE EXCEPTION WILL BE OVER
NORTHEAST NM WHERE BREEZY DOWN SLOPE WEST WINDS WIND WILL KEEP RH
RECOVERIES IN THE FAIR TO GOOD RANGE.
THE NAM...GFS...AND EUROPEAN WEATHER PREDICTION MODELS ARE IN VERY
GOOD AGREEMENT WITH REGARD TO A WEAK UPPER LEVEL TROUGH EJECTING
NORTHEASTWARD FROM THE BAJA ACROSS FAR NORTHWEST MEXICO AND SOUTHERN
AND CENTRAL NEW MEXICO TUESDAY NIGHT AND WEDNESDAY. AHEAD OF THE
SYSTEM...A MOIST SOUTHERLY FLOW WILL TAP UNSEASONABLY DEEP
SUBTROPICAL MOISTURE FROM OLD MEXICO. THE GFS IS QUITE A BIT MORE
VIGOROUS THAN THE EUROPEAN MODEL WITH THE MOISTURE TRANSPORT AND THE
ATMOSPHERIC LIFT ASSOCIATED WITH THE UPPER TROUGH PASSAGE. IN ANY
EVENT...THE OVERALL MODEL TREND IS WETTER...WITH THE POTENTIAL FOR
SCATTERED WETTING PRECIPITATION OVER THE SOUTH...AND POSSIBLY AS FAR
NORTH AS INTERSTATE 40 FOR WEDNESDAY.
AFTER GOOD TO EXCELLENT VENTILATION IN MOST LOCATIONS OVER THE
WEEKEND...POOR VENTILATION WILL SPREAD ACROSS CENTRAL AND WESTERN
PARTS OF THE FORECAST AREA FROM THE WEST DURING THE FIRST HALF OF
THE COMING WORK WEEK. VENTILATION IS EXPECTED TO IMPROVE OVER
SOUTHERN AND CENTRAL NEW MEXICO...ASSOCIATED WITH THE PASSING THE
WEAK UPPER LEVEL TROUGH AND THE ASSOCIATED PRECIPITATION.
ECMWF AND CANADIAN MODEL ARE IN VERY GOOD AGREEMENT WITH ONE ANOTHER
FOR NEXT WEEKEND INTO EARLY NEXT WEEK...HINTING AT A MAJOR WEATHER
PATTERN CHANGE TOWARD COLDER AND WETTER CONDITIONS. STAY TUNED.
33
&&
.AVIATION...
06Z TAF CYCLE
MID/HIGH LEVEL MOISTURE BOWING NORTHWARD OVER SOUTHERN AND
CENTRAL NEW MEXICO...WHILE TOP DOWN MOISTENING TO
CONTINUE...MAINLY EMBEDDED SCATTERED LIGHT SHOWERS WILL
RESULT...WHICH MAY OBSCURE HIGHER TERRAIN FAVORING AREAS SOUTH OF
HIGHWAY 60 NEXT 12 HOURS. IN ADDITION...DISTURBANCE PASSING
THROUGH GREAT BASIN AND CENTRAL ROCKIES MAY RESULT IN ISOLD -RASN
OR EVEN A SHORT LIVED THUNDERSTORM NEAR THE FOUR CORNERS AND THE
NORTHWEST MTS AND MAY RESULT IN BRIEF MT OBSCURATION THRU 12Z
SUNDAY. 00Z NAM12 AND LATEST RUC INDICATE SOME LOW/MID LEVEL
MOISTURE MAY MAKE A RUN UP THE RGV POSSIBLY REACHING KABQ BY 12Z
SUNDAY...THEREFORE MORE WIDESPREAD MT OBSCURATION POSSIBLE BUT CIGS
MAY REMAIN VFR.
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 57 27 58 27 / 10 5 5 0
DULCE........................... 53 19 54 17 / 20 5 5 0
CUBA............................ 57 24 56 22 / 10 0 5 0
GALLUP.......................... 56 22 55 19 / 10 5 5 0
EL MORRO........................ 52 20 52 18 / 10 5 0 0
GRANTS.......................... 59 24 59 21 / 10 0 0 0
QUEMADO......................... 58 29 57 25 / 5 5 0 0
GLENWOOD........................ 65 29 65 27 / 10 5 0 0
CHAMA........................... 49 22 49 17 / 20 5 5 0
LOS ALAMOS...................... 54 32 53 30 / 10 5 0 0
PECOS........................... 54 32 55 29 / 5 0 0 0
CERRO/QUESTA.................... 53 21 53 19 / 5 5 0 0
RED RIVER....................... 46 19 47 15 / 5 5 5 0
ANGEL FIRE...................... 50 21 51 15 / 5 5 5 0
TAOS............................ 55 20 55 15 / 5 5 0 0
MORA............................ 56 28 56 25 / 5 5 0 0
ESPANOLA........................ 61 26 60 25 / 5 0 0 0
SANTA FE........................ 55 32 55 28 / 5 5 0 0
SANTA FE AIRPORT................ 58 28 57 27 / 5 0 0 0
ALBUQUERQUE FOOTHILLS........... 60 35 59 33 / 5 0 0 0
ALBUQUERQUE HEIGHTS............. 60 37 60 35 / 5 0 0 0
ALBUQUERQUE VALLEY.............. 63 34 62 31 / 5 0 0 0
ALBUQUERQUE WEST MESA........... 62 34 61 32 / 5 0 0 0
LOS LUNAS....................... 63 29 62 26 / 5 0 0 0
RIO RANCHO...................... 61 34 60 32 / 5 0 0 0
SOCORRO......................... 68 34 67 31 / 10 0 0 0
SANDIA PARK/CEDAR CREST......... 59 33 58 31 / 10 0 0 0
TIJERAS......................... 61 33 59 31 / 10 0 0 0
MORIARTY/ESTANCIA............... 61 24 60 21 / 5 0 0 0
CLINES CORNERS.................. 58 31 58 30 / 5 0 0 0
GRAN QUIVIRA.................... 60 34 60 31 / 10 5 0 0
CARRIZOZO....................... 64 35 65 30 / 20 5 0 0
RUIDOSO......................... 58 37 60 35 / 20 5 5 0
CAPULIN......................... 60 31 59 29 / 5 5 5 0
RATON........................... 62 25 62 23 / 0 5 5 0
SPRINGER........................ 63 26 63 24 / 0 5 5 0
LAS VEGAS....................... 60 31 60 27 / 0 5 5 0
CLAYTON......................... 69 37 68 34 / 5 5 5 0
ROY............................. 64 33 63 31 / 0 5 5 0
CONCHAS......................... 69 34 69 30 / 5 5 0 0
SANTA ROSA...................... 69 37 69 32 / 5 5 0 0
TUCUMCARI....................... 71 37 70 30 / 5 5 5 0
CLOVIS.......................... 68 39 69 34 / 20 5 5 0
PORTALES........................ 68 39 70 33 / 20 5 5 5
FORT SUMNER..................... 69 38 70 33 / 10 5 0 0
ROSWELL......................... 74 41 76 35 / 20 5 0 0
PICACHO......................... 70 39 70 34 / 20 5 5 0
ELK............................. 66 41 66 36 / 30 5 5 0
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHY
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
559 AM CST SUN NOV 18 2012
.SHORT TERM...THROUGH TUESDAY NIGHT
212 AM CST SUN NOV 18 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION CHANCES TONIGHT INTO
MONDAY AS WELL AS TEMPERATURES THROUGHOUT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A DEEP TROUGH FROM JUST OFF THE COAST OF BRITISH COLUMBIA
INTO THE PACIFIC NORTHWEST...AND SOUTHWEST FLOW FROM THE DESERT
SOUTHWEST THROUGH THE UPPER MISSISSIPPI RIVER VALLEY REGION. WITHIN
THIS SOUTHWEST FLOW...SHORTWAVES OF NOTE ARE ALONG THE UTAH/COLORADO
BORDER AND IN NORTHWEST MINNESOTA. DPVA AHEAD OF THIS LATTER
SHORTWAVE COMBINED WITH 295-300K ISENTROPIC LIFT PRODUCED SHOWERS
ACROSS NORTHEAST MINNESOTA. THE 295K ISENTROPIC LIFT ALSO EXTENDED
SOUTHWEST FROM NORTHEAST MINNESOTA INTO CENTRAL IOWA...AND ALONG
THIS ZONE IS A BAND OF STRATUS WITH CEILINGS BETWEEN 6000-9000 FT.
THE BAND OF STRATUS ALSO SEPARATES MOIST AIR FROM VERY DRY AIR AT
850MB. FOR EXAMPLE...FROM 00Z SOUNDINGS...THE 850MB DEWPOINT AT DVN
WAS -20C WHILE IT WAS -2C AT MPX AND 1C AT OAX. THE BROAD SOUTHWEST
FLOW ALOFT HAS RESULTED IN A WARM ADVECTION PATTERN ACROSS THE UPPER
MIDWEST. 850MB TEMPS WERE +6C AT MPX AND OAX AT 00Z. THE LOW LEVEL
SOUTHERLY FLOW WAS FAIRLY STRONG WITH 925MB PROFILER AND VWP DATA
SHOWING SPEEDS OF 35-45KT AROUND THE FORECAST AREA. THESE WINDS ARE
HOLDING TEMPERATURES UP FROM THE MID 30S TO MID 40S...WARMEST IN
SOUTHEAST MINNESOTA.
TODAY AND TONIGHT...FOCUS IS ON THAT SHORTWAVE ALONG THE
UTAH/COLORADO BORDER. GOOD MODEL AGREEMENT REMAINS ON THIS SHORTWAVE
LIFTING UP THROUGH THE SOUTHWEST FLOW AND MOVING INTO WESTERN
PORTIONS OF THE FORECAST AREA BY 12Z MONDAY. BRIEF RIDGING DEVELOPS
OVER THE FORECAST AREA TODAY DOWNSTREAM OF THIS SHORTWAVE...WHICH
SHOULD ACT TO CLEAR THE CLOUDS UP SOMEWHAT. WITH THE RELATIVELY
SPEAKING WARM START...SUNSHINE AND 925MB TEMPS AROUND 6C WHICH ARE
SIMILAR TO YESTERDAY...ANTICIPATING HIGHS TO BE FAIRLY SIMILAR TO A
FEW DEGREES WARMER THAN YESTERDAY. FOR TONIGHT...THE 850MB MOISTURE
STREAM CURRENTLY OVER WESTERN MINNESOTA AND IOWA WILL GET PUSHED
EAST INTO THE FORECAST AREA BY THE SHORTWAVE. THE MAIN QUESTION IS
IF DPVA AND ISENTROPIC LIFT AHEAD OF THIS SHORTWAVE WILL BE STRONG
ENOUGH TO ACT ON THIS MOISTURE AND PRODUCE PRECIPITATION. MID CLOUD
DEVELOPMENT IS A CERTAINTY...GIVEN WHAT HAPPENED LAST EVENING ON
THE LEADING EDGE OF THE 850MB MOISTURE STREAM. THE 18.00Z
NAM/REGIONAL CANADIAN PAINT A DRY PICTURE AND EVEN THE GFS WHICH
LOOKS TO HAVE A BIT TOO MUCH MOISTURE COMPARED TO ALL OTHER MODELS
PRODUCES LITTLE IF ANY PRECIPITATION BEFORE 12Z. THE 17.12Z ECMWF
MEANWHILE REMAINS MOST ROBUST WITH 0.1-0.2 OF AN INCH OVER NORTHEAST
IOWA BETWEEN 06-12Z MONDAY. NEW 18.00Z ECMWF IS SLIGHTLY DRIER. SREF
TRENDS HAVE SHOWN LESS MEMBERS PRODUCING 0.01 OF AN INCH OVER THE
LAST 5 RUNS...DOWN FROM 40-50 PERCENT TO 10-30 PERCENT. AT THIS
POINT...CANNOT SEE GOING WITH THE MORE ROBUST ECMWF SOLUTION AND
HAVE KEPT CHANCES LOW IN THE 20-30 PERCENT RANGE...CENTERED IN THE
09-12Z PERIOD. WITH THE INCREASING CLOUDS AND A SOUTHERLY BREEZE
BEING MAINTAINED...A SLIGHTLY WARMER NIGHT THAN TONIGHT IS
ANTICIPATED.
MONDAY AND MONDAY NIGHT...THE SHORTWAVE OVER WESTERN PORTIONS OF THE
FORECAST AREA AT 12Z LOOKS TO MOVE THROUGH THE REST OF THE FORECAST
AREA BY EARLY AFTERNOON...WHILE THE TAIL END OF THE DEEP TROUGHING
IN THE PACIFIC NORTHWEST IS PROGGED TO DROP DOWN INTO THE FORECAST
AREA AFTER MIDNIGHT MONDAY NIGHT. THIS LATTER SHORTWAVE WILL COME
THROUGH DRY SINCE THE SHORTWAVE COMING THROUGH MONDAY MORNING ENDS
UP SCOURING OUT A LOT OF THE MOISTURE. THUS ALL FOCUS IS ON THE
MONDAY MORNING PERIOD. AGAIN HERE...MODELS ARE AT ODDS WITH FORCING
AND MOISTURE AVAILABILITY. THE 18.00Z NAM/REGIONAL CANADIAN SAYS
THERE IS TOO MUCH DRY AIR BELOW 800MB AND THE FORCING IS TOO WEAK
ABOVE IT TO ALLOW FOR PRECIPITATION TO MAKE IT TO THE SURFACE. ON
THE OTHER HAND...THE 18.00Z GFS AND 17.12Z/18.00Z ECMWF ARE MORE
ROBUST IN BOTH ARENAS AND END UP PRODUCING LIGHT QPF ACROSS MUCH OF
THE AREA. SREF TRENDS FOR THE FULL DAY MONDAY ARE ALSO SIMILAR TO
06-12Z MONDAY...SHOWING A DECLINE OF MEMBERS PRODUCING AT LEAST 0.01
OF AN INCH. IT USED TO BE UP AT 70-80 PERCENT BUT NOW IS DOWN TO
30-60 PERCENT. THUS...CONFIDENCE REMAINS TOO LOW TO ADJUST THE
PREVIOUS FORECAST PRECIPITATION CHANCES OF 20-40 PERCENT. CERTAINLY
IF ANY PRECIPITATION OCCURS...ANY RAIN LOOKS REALLY LIGHT. REGARDING
CLOUD COVER...IT NOW APPEARS THAT THE SHORTWAVE ON MONDAY MORNING
SHOULD HELP TO CLEAR THE CLOUDS OUT AS IT MOVES AWAY DURING THE
AFTERNOON. THERE MAY BE AN INCREASE OF CIRRUS WITH THE SHORTWAVE
COMING IN MONDAY NIGHT...BUT THATS ABOUT IT. NOTE THAT THERE IS
CONCERN FOR A LOW CLOUD DECK BASED ON THE GFS/ECMWF 925MB RH
PROGS...BUT THEY MAY BE TOO MOIST. FOR NOW TAKING A COMPROMISE
APPROACH BY SPEEDING UP THE CLEARING SOME FROM THE PREVIOUS
FORECAST. HAVING MORE CLOUDS MONDAY WILL HOLD THE TEMPERATURES DOWN
A FEW DEGREES FROM HIGHS OVER THE WEEKEND. A COOLER NIGHT SEEMS
LIKELY TOO FOR MONDAY NIGHT...ESPECIALLY IF THE CLEARING OCCURS.
TUESDAY AND TUESDAY NIGHT...IN THE WAKE OF THAT SHORTWAVE DROPPING
INTO THE FORECAST AREA TUESDAY MORNING...SOME FAIRLY STRONG RIDGING
IS PROGGED TO BUILD INTO THE FORECAST AREA BY TUESDAY EVENING. ABOUT
ALL THAT SHORTWAVE IS GOING TO DO IS PREVENT THE 850MB TEMP
CLIMB...NOTED BY 850MB TEMPS AT 18Z TUESDAY OF 5-7C. ONCE THE
RIDGING STARTS BUILDING IN...THESE TEMPS CLIMB...TOPPING OUT AT 8C
EAST TO 11C WEST BY 12Z WEDNESDAY. WITH WHAT SHOULD BE PLENTY OF
SUN...HIGHS SHOULD BE ABLE TO TOP OUT IN THE 50S AGAIN ON TUESDAY
GIVEN THE AFOREMENTIONED 850MB TEMPS. INCREASING SOUTHERLY FLOW
TUESDAY NIGHT IN THE WAKE OF HIGH PRESSURE THAT CROSSES THE AREA ON
TUESDAY WILL HELP TO KEEP TEMPERATURES UP IN SOUTHEAST MINNESOTA.
FOLLOWED A BLEND OF GUIDANCE FOR LOWS.
.LONG TERM...WEDNESDAY THROUGH SATURDAY NIGHT
212 AM CST SUN NOV 18 2012
MAIN FOCUS CONTINUES TO BE ON A POTENT SHORTWAVE TROUGH ENTERING THE
PACIFIC NORTHWEST WEDNESDAY MORNING. MODEL AGREEMENT HANDLING THIS
POTENT TROUGH BEGINS TO DECLINE AS EARLY AS 12Z THURSDAY...WITH THE
18.00Z ECMWF/CANADIAN SHOWING A DIGGING NATURE TO IT INTO THE
NORTHERN PLAINS. MEANWHILE...THE 18.00Z GFS TAKES A MORE PROGRESSIVE
APPROACH AND SENDS IT UP INTO NORTHERN ONTARIO ON THURSDAY. BOTH THE
GFS AND ECMWF HAVE COMPLETELY FLIPPED FROM PREVIOUS RUNS WITH THE
HANDLING OF THIS POTENT TROUGH. THE 18.00Z ECMWF LOOKS MORE LIKE THE
17.00Z GFS WHILE THE 18.00Z GFS LOOKS MORE LIKE THE 16.12Z ECMWF.
THIS HAS SIGNIFICANT IMPLICATIONS ON THE TEMPERATURE AND WIND
FORECASTS...PRIMARILY FRIDAY AND BEYOND. WITH THE MORE DIGGING
NATURE OF THE ECMWF/CANADIAN...THEY END UP CARVING OUT A DEEP TROUGH
ACROSS THE WESTERN GREAT LAKES REGION FOR FRIDAY...THOUGH WITHIN
THIS GROUP THE CANADIAN IS MORE PROGRESSIVE. WHICHEVER MODEL
SCENARIO PLAYS OUT...IT APPEARS DRY WEATHER WOULD BE THE RULE WITH
THE BEST JUXTAPOSITION OF FORCING AND MOISTURE EITHER NORTH OR
SOUTHEAST OF THE AREA. GIVEN THE DIFFERENCES EARLY IN THE LONG TERM
PERIOD...HARD TO SAY HOW THE WEEKEND WILL PLAY ITSELF OUT. NOTE THAT
THE 18.00Z GFS ENSEMBLES HAVE A PRETTY GOOD SPREAD TOO WITH REGARDS
TO THE POTENT TROUGH. THUS FOR NOW HAVE STAYED WITH A CONSENSUS
APPROACH WHEN IT COMES TO THE WEEKEND...YIELDING COOLER AND A
CONTINUATION OF DRY CONDITIONS.
REGARDING TEMPERATURES...WEDNESDAY AND THANKSGIVING DAY STILL LOOK
WELL ABOVE NORMAL...ESPECIALLY WEDNESDAY AS 925MB TEMPS CLIMB TO
10-12C FOR 18Z. MIXING TO 925MB YIELDS HIGHS FROM THE UPPER 50S TO
MIDDLE 60S...THUS HAVE BOOSTED HIGHS A FEW DEGREES. RECORD HIGHS FOR
WEDNESDAY ARE 72 AT LA CROSSE AND 69 AT ROCHESTER...STILL 5-10
DEGREES ABOVE THE GOING FORECAST. NOTE THAT 850MB TEMP
STANDARDIZED ANOMALIES HAVE NOW JUMPED TO NEAR 2...SUPPORTING THE
INCREASING IN HIGH TEMPERATURES. SOME COOLING IN 925MB TEMPS
TAKES PLACE ON THANKSGIVING DAY AS A COLD FRONT MOVES INTO THE
REGION. STILL...MOST LOCATIONS SHOULD TOP OUT AT LEAST IN THE MID
TO UPPER 50S...MAYBE EVEN 60 AT SOME SOUTH OF I-90. RECORD HIGH
FOR THURSDAY IS 59 AT LA CROSSE AND 65 AT ROCHESTER...THUS LA
CROSSE MAY BE DOABLE TO BREAK. TEMPERATURES SHOULD RETURN CLOSER
TO NORMAL FOR FRIDAY INTO THE WEEKEND IN THE WAKE OF THE COLD
FRONT. IF THE 18.00Z ECMWF IS CORRECT...WE COULD EVEN BE BELOW
NORMAL FOR THE WEEKEND.
&&
.AVIATION...TODAY AND TONIGHT
557 AM CST SUN NOV 18 2012
A SCATTERED TO BROKEN DECK OF ALTOCUMULUS CLOUDS WILL GRADUALLY
DISSIPATE ACROSS SOUTHEAST MINNESOTA AND NORTHEAST IOWA THIS
AFTERNOON. A COLD FRONT WILL BRING ANOTHER ROUND OF MID AND HIGH
CLOUDS TO THE AREA TONIGHT. THERE WILL ALSO BE SOME ISOLATED TO
SCATTERED SHOWERS ACROSS SOUTHEAST MINNESOTA AND NORTHEAST IOWA
AFTER 19.06Z TONIGHT. SINCE THEIR COVERAGE IS VERY SMALL...DID NOT
INCLUDE THEM AT KRST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
212 AM CST SUN NOV 18 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
413 PM CST SUN NOV 18 2012
.DISCUSSION...
213 PM CST
TONIGHT...
ANTI-CYCLONIC FEATURE HAS BECOME STRETCHED OUT WITH A CENTER OVER
SOUTHEAST QUEBEC AND CONTINUES TO PROVIDE A MAIN INFLUENCE ACROSS
THE OHIO VALLEY/MID-MISSISSIPPI VALLEY. TO THE WEST OF THIS
INFLUENCE ACROSS PORTIONS OF THE UPPER MIDWEST/CENTRAL PLAINS...THE
PRESSURE GRADIENT IS TIGHTER AND RESULTING IN OCCASIONALLY GUSTY
SOUTH WINDS IN THOSE AREAS. VISIBLE IMAGERY EARLY THIS AFTERNOON
DEPICTS A CHANNEL OF CIRRUS CLOUDS FROM NORTHERN IL STRETCHING WEST
THROUGH IOWA...THEN A MORE EXPANSIVE AREA OF CIRRUS CLOUDS ACROSS
THE SOUTHERN PLAINS INTO THE SOUTHERN ROCKIES. THE SOUTHERN ROCKIES
IS THE AREA THAT GUIDANCE HAS BEEN FOCUSED ON FOR THE DEVELOPMENT OF
A WEAK WAVE THAT WILL SLIDE ALONG THE FRONTAL BOUNDARY AND
OVERSPREAD CLOUDS AND LGT PRECIP TO PORTIONS OF THE GREAT LAKES MON
NGT.
CLOUD COVER WILL STEADILY SLIDE OVERHEAD THIS
EVENING/OVERNIGHT...WITH A FEW POCKETS OF CLEARING. DEEPER MOISTURE
WILL REMAIN WEST OF THE CWFA THROUGH THE OVERNIGHT...MAINLY OVER
IA/MO/KS/OK. WITH POTENTIALLY HIGH CLOUDS OVERHEAD SFC TEMPS SHOULD
BE ABLE TO RADIATE INTO THE MID/UPR 30S ACROSS THE REGION. SFC WINDS
SHOULD CONTINUE OVERNIGHT AROUND 10 MPH OR LESS...HOWEVER SHOULD BE
JUST ENOUGH TO PREVENT LARGE SCALE FOG DEVELOPMENT. A FEW PROTECTED
AREAS AND LOCATIONS CLOSEST TO STREAMS...MAY SEE PATCHY FOG DEVELOP.
THE OTHER AREAS THAT COULD SEE PATCHY FOG MAY BE THE FAR NORTHEAST
CORNER OF NORTHEAST IL...WITH A WEAK ONSHORE FLOW AND MARINE
MOISTURE BLEEDING INLAND A FEW MILES.
CONFIDENCE...HIGH.
MONDAY THROUGH TUESDAY...
ANTI-CYCLONIC FLOW IS PROGGED TO BE THE MAIN FEATURE FOR EARLY
WEEK...HOWEVER A WEAK FRONTAL BOUNDARY IS PROGGED TO PUSH EAST
ACROSS THE MISSISSIPPI VALLEY INTO THE GREAT LAKES MONDAY
NIGHT/EARLY TUESDAY. GUIDANCE HAS CONTINUED TO HINT THAT SOME
MOISTURE WILL ACCOMPANY THIS BOUNDARY...ALTHOUGH LOOKING UPSTREAM AT
CURRENT CONDITIONS IT APPEARS THE SCENARIO OF LIGHT PRECIP IS LOW
FOR MONDAY NIGHT/EARLY TUE. ANOTHER POTENTIAL LIMITING FACTOR IS
THAT THE EXPECTED DOWNSTREAM RIDGE MAY CONTINUE TO HOLD WITH
DIFFLUENT FLOW IN THE MID-LVLS...WHICH WOULD AID IN DRYING THE
MOISTURE AT THE MID-LVLS. LLVL FLOW MAY BACK SLIGHTLY TO THE
SOUTHEAST...WHICH COULD ALSO AID IN MOISTURE AVAILABILITY. FORCING
DOES NOT APPEAR TO BE VERY POTENT EITHER. MANY PLUMES SUGGEST A DRY
MON NGT/EARLY TUE AS WELL ACROSS THE CWFA. BASED ON THESE
AFOREMENTIONED ELEMENTS...HAVE OPTED TO REMOVE MENTION OF PRECIP
ACROSS THE CWFA FOR MON NGT/EARLY TUE...AND ADJUSTED ANY PRECIP TO
LOCATIONS FURTHER NORTH ACROSS WISC/LAKE MICHIGAN/LOWER MICHIGAN. IF
PRECIP DOES DEVELOP...IT APPEARS IT MAY END UP BEING SPRINKLES.
OVERALL EXPECT JUST CLOUDS TO BE ON THE INCREASE FROM THIS SYSTEM.
TEMPS BOTH DAYS WILL CONTINUE TO BE MILD WITH A THERMAL RIDGE OF 5
TO 7 DEG C MONDAY...AND 6 TO 8 DEG C TUESDAY. WITH OPTIMAL CONDS
EXPECTED BOTH DAYS...TEMPS SHOULD EASILY WARM INTO THE MID/UPR 50S.
FOR LOCATIONS ALONG AND SOUTH OF I-80 TEMPS COULD TOUCH 60 DEGREES
TUESDAY AFTERNOON. SEVERAL 2M TEMP PLUMES FOR THIS PERIOD ALSO
SUPPORT THIS MAX TEMP FORECAST. OVERNIGHT LOWS WILL ALSO BE
MILD...UPR 30S/LOW 40S.
CONFIDENCE...HIGH.
PRECIP CONFIDENCE...MEDIUM/HIGH.
WEDNESDAY...
ONE OF THE BUSIEST TRAVEL DAYS OF THE YEAR...AND IT APPEARS MOTHER
NATURE WILL COOPERATE AND PRODUCE OPTIMAL TRAVEL CONDITIONS FOR
NORTHERN IL/NORTHWEST IN. ANTI-CYCLONIC FLOW WILL PUSH BACK INTO THE
REGION AND ERODE THE CLOUDS TUE NGT/EARLY WED...WITH COULD ALLOW
TEMPS EARLY WED BEFORE SUNRISE TO DIP INTO THE LOW 30S. THEN A LARGE
DIURNAL CURVE IS EXPECTED FOR WED AFTERNOON. 850MB THERMAL RIDGE OF
7 TO 9 DEG C IS PROGGED TO SLIDE OVERHEAD FROM THE
WEST/SOUTHWEST...WITH LLVL FLOW TURNING SOUTH/SOUTHWEST. THE BEST
PRESSURE GRADIENT AND ADVECTION APPEARS TO BE DISPLACED TO THE
NORTHWEST/WEST OF THE CWFA...HOWEVER IT APPEARS TEMPS COULD EASILY
WARM TO 60 DEG ACROSS THE AREA. FOR AREAS ALONG AND WEST OF A
ROCKFORD/KANKAKEE LINE...TEMPS MAY PUSH TO 61 TO 63 DEG.
CONFIDENCE...HIGH.
THANKSGIVING THROUGH SATURDAY...
THE ANOMALOUS WARM/DRY PATTERN THAT HAS DOMINATED MUCH OF THE REGION
FOR THE PAST SEVERAL DAYS...MAY BE TRANSITIONING INTO A MORE ACTIVE
PATTERN. ABOVE NORMAL 500MB HEIGHTS WILL PERSIST THROUGH THUR...THEN
STEADILY WEAKEN INTO A SEMI-ZONAL FLOW AND POSSIBLY A TROUGH DIGGING
INTO THE UPPER MIDWEST/CENTRAL ROCKIES DEVELOPS. GUIDANCE BECOMES
RATHER NOISY IN THE EXTENDED PERIODS FROM FRI-SAT...WHICH IS
INDICATED BY THE ENVELOPE OF SOLUTIONS THAT THE ENSEMBLES PROG AS
WELL AS OPERATIONAL GFS/ECMWF. THE FIRST FEW PERIODS WILL CONTINUE
TO BE MILD WITH TEMPS NEAR 60 TO POSSIBLY THE LOW 60S IN THE
AFTERNOON FOR THANKSGIVING...HOWEVER THIS WILL CHANGE FOR FRI/SAT.
500MB TROUGH CONTINUES TO BE PROGGED BY OPERATIONAL SOLUTIONS AND
ANTI-CYCLONIC FLOW WILL DEPART TO THE SOUTHEAST. THIS WILL AID IN A
STRENGTHENING SOUTHWEST FLOW THUR NGT/FRI AS A FRONTAL BOUNDARY
BEGINS TO APPROACH THE REGION. 850MB THERMAL TROUGH OF -2 TO -5 DEG
C SHOULD ARRIVE ACROSS THE REGION MIDDAY FRI...THUS TEMPS FRI MAY
STRUGGLE TO WARM WITH POSSIBLY THE WARMEST TEMPS FOR THE DAY
OCCURRING IN THE MORNING. 500MB SPEED MAX PIVOTS EAST ACROSS THE
UPPER MIDWEST/NORTHERN GREAT LAKES...HOWEVER APPEARS TO BE MAINLY
MOISTURE STARVED. AT THIS POINT HAVE CONTINUED TO MENTION CHC
POPS...AND TEMPS SHOULD BE COOL ENOUGH TO PRODUCE A POSSIBLE RA/SN
MIX HOWEVER MOISTURE RAPIDLY PIVOTS NORTHEAST BY FRI AFTN/EVE THAT
THIS WOULD BE RESTRICTED TO THE LAKE ENVIRONMENT AND LOWER MICHIGAN.
THEN ANTI-CYCLONIC FLOW IS PROGGED TO BUILD BACK INTO THE
MIDWEST/GREAT LAKES REGION FOR THE REMAINDER OF THE WEEKEND AND
PROVIDE DRY WEATHER. IN ADDITION THE LONGER TERM MODELS CONTINUE TO
HINT THAT TEMPS MAY YET AGAIN PUSH BACK ABOVE NORMAL FOR THE SECOND
HALF OF THE WEEKEND AND POSSIBLY CONTINUE INTO EARLY THE FOLLOWING
WEEK.
CONFIDENCE...HIGH.
BEACHLER
&&
.CLIMATE...
321 AM CST
A SHIFT IN THE UPPER PATTERN WILL ALLOW SOME MODERATION OF
TEMPERATURES GOING INTO THE WEEKEND AND PREVAILING FOR SEVERAL DAYS
THEREAFTER. WHILE THE MODERATION WILL HELP OBSERVED TEMPERATURES TO
EXCEED DAILY NORMALS THE FACT THAT INCREASINGLY SHORTER DAYS AND
LOWERING SUN ANGLES RESULT IN THE NORMAL HIGH TEMPERATURE FALLING BY
1 DEGREE F ABOUT EVERY 2 DAYS. SO...IT IS THE COMBINATION OF THE
LOWERING NORMAL MAXIMUM TEMPERATURES ALONG WITH THE WARMING THAT
WILL RESULT IN DAYTIME TEMPERATURES TO CLIMB TO ABOVE NORMAL...WHICH
ARE NOW ONLY IN THE UPPER 40S AT MID NOVEMBER.
NORMALS...
CHICAGO ROCKFORD
MAX MIN MAX MIN
NOV 01 56 38 56 36
NOV 17 47 32 47 30
NOV 30 40 27 39 24
THIS UNUSUAL PATTERN WILL ALSO ALLOW HIGH TEMPERATURES ON
WEDNESDAY AND THURSDAY...THANSKGIVING...TO COME CLOSE TO THE
RECORD HIGH TEMPERATURES. WHILE FORECAST HIGH TEMPERATURES ARE
CURRENTLY A FEW DEGREES COOLER THAN THE RECORDS...HERE ARE THE THE
MAX TEMPERATURE RECORDS FOR FOOD FOR THOUGHT:
CHICAGO ROCKFORD
NOV 21 72 1913 73 1913
NOV 22 69 1913 69 2010
TRS/JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* VARIABLE SE-SSE WINDS THROUGH EARLY EVENING BECOMING STEADIER
SOUTHEAST.
MDB
//DISCUSSION...UPDATED 22Z...
LAKE INFLUENCE SEEMS TO BE WEAKENING FOR AREAS EAST AND NORTH OF
ORD...POTENTIALLY DUE TO INCREASING HIGH LEVEL CLOUD SHIELD. AREAS
FROM UGN TO PWK THAT HAD SEEN A LARGER EAST COMPONENT TO THE
SOUTHERLY WIND HAVE TURNED MORE SOUTHEASTERLY FOR THE MOST
PART...WITH AREAS RIGHT ALONG THE ILLINOIS SHORE DOING SIMILAR. SO
IT APPEARS THAT A LARGER SOUTH WIND COMPONENT WILL PREVAIL ACROSS
THE CHI AREA TERMINALS WITH SOME VARIABILITY BETWEEN SE AND SSE
AT ORD/MDW FOR THE NEXT FEW HOURS.
MDB
FROM 18Z...
LATEST HI RES RUC AND HRR MODEL OUTPUT CONTINUE TO SUGGEST A WEAK
LAKE BREEZE...SUCH AS OCCURRED FRI AND SAT...IS TO DEVELOP AND
EVENTUALLY MOVE INLAND TO MDW AND ORD VICINITY 21-22Z TIME-FRAME.
RESULT IS THAT 5-10 KT SSE WINDS BACK A BIT TO SE-ESE FOR THE
LATE AFTERNOON. MARINE OBS SITES CURRENTLY SHOW A SE WIND
DIRECTION AT WAUKEGAN AND BURNHAM HARBORS WITH MESONET OBS
INDICATING LIGHT VARIABLE WINDS FROM JUST ASHORE TO A COUPLE MILES
INLAND SUGGESTING THE WEAK BOUNDARY IS ALONG THE SHORE AND LITTLE
RESISTANCE TO MOVING GRADUALLY INLAND AS CURRENT SMALL TEMPERATURE
DIFFERENTIAL BETWEEN LAND AND WATER CONTINUES TO INCREASE.
WITH LOSS OF HEATING TOWARDS DUSK AND DISSIPATION OF LAKE BREEZE
EARLY IN THE EVENING WINDS TO RETURN TO SSE-S. SPEEDS TO BE LESS
THAN 10 KT AS STRONGER SSW FLOW AHEAD OF AN APPROACHING COLD
FRONT/SURFACE TROUGH MOVING EAST ACROSS THE NORTHERN AND CENTRAL
PLAINS WILL BE DECOUPLED FROM THE SURFACE DURING THE NIGHT. AFTER
SUNRISE MONDAY MORNING STRONG...SHALLOW INVERSION WILL BEGIN TO BE
ERODED THOUGH WINDS AT TOP OF BOUNDARY LAYER DURING LATER MORNING
AND AFTERNOON ARE ONLY 14-17KT. EXPECT SOUTHERLY SURFACE WINDS TO
AVERAGE 8-10 KT AFTER SOME SURFACE HEATING AND MIXING WITH
POSSIBLE OCCASIONAL GUSTS OF 14-17KT.
EXPECT VFR CONDITIONS THROUGHOUT THE VALID TAFOR PERIOD WITH ONLY
SCT-BKN MID AND HIGH LEVEL CLOUDS.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* HIGH CONFIDENCE IN VARIABLE WIND DIRECTION THROUGH EARLY
EVENING.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...VFR WITH SLIGHT CHANCE OF LIGHT RAIN.
TUESDAY AND WEDNESDAY...VFR.
THANKSGIVING...VFR WITH A CHANCE OF SHOWERS LATE.
FRIDAY AND SATURDAY...VFR.
LENNING
&&
.MARINE...
225 PM CST
A LARGE RIDGE OF HIGH PRESSURE EXTENDS FROM NOVA SCOTIA TO THE
LOWER MISSISSIPPI VALLEY.. THE RIDGE IS EXPECTED TO ONLY DRIFT
VERY SLOWLY EAST OVER THE NEXT SEVERAL DAYS WHILE GRADUALLY
WEAKENING. A TROUGH OF LOW PRESSURE WILL MOVE INTO THE DAKOTAS
TODAY...THEN INTO THE WESTERN GREAT LAKES MONDAY NIGHT AS IT
WEAKENS SLIGHTLY. THIS WILL KEEP GENERALLY SOUTHERLY WINDS OVER
THE LAKE UNTIL EARLY NEXT WEEK. AS THE TROUGH FURTHER WEAKENS TUESDAY
NIGHT AND AN ASSOCIATED WEAK COLD FRONT CROSSES LAKE MICHIGAN...
WINDS WILL SHIFT TO NORTHWESTERLY. HOWEVER...NO INCREASE IN WINDS
IS LIKELY AS A WEAK RIDGE OF HIGH PRESSURE WILL IMMEDIATELY FILL
IN BEHIND THE FRONT AND THERE IS NO SIGNIFICANTLY COLD AIR BEHIND
THE FRONT. ANOTHER LOW IS FORECAST TO DEVELOP OVER MONTANA ON
WEDNESDAY AND QUICKLY TRACK EASTWARD TO NEAR LAKE SUPERIOR BY
THURSDAY EVENING. THE LOW WILL THEN TURN NORTHEAST TOWARD SOUTHERN
JAMES BAY...DRAGGING A COLD FRONT ACROSS LAKE MICHIGAN LATE
THURSDAY NIGHT OR FRIDAY MORNING. THIS FRONT IS EXPECTED TO BE
MUCH STRONGER THAN THE PREVIOUS FRONT...BRINGING IN A MUCH COLDER
INFLUX OF COLDER AIR...AND WILL BRING STRENGTHENING NORTHWESTERLY
WINDS TO THE LAKE,
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
225 PM CST SUN NOV 18 2012
.DISCUSSION...
213 PM CST
TONIGHT...
ANTI-CYCLONIC FEATURE HAS BECOME STRETCHED OUT WITH A CENTER OVER
SOUTHEAST QUEBEC AND CONTINUES TO PROVIDE A MAIN INFLUENCE ACROSS
THE OHIO VALLEY/MID-MISSISSIPPI VALLEY. TO THE WEST OF THIS
INFLUENCE ACROSS PORTIONS OF THE UPPER MIDWEST/CENTRAL PLAINS...THE
PRESSURE GRADIENT IS TIGHTER AND RESULTING IN OCCASIONALLY GUSTY
SOUTH WINDS IN THOSE AREAS. VISIBLE IMAGERY EARLY THIS AFTERNOON
DEPICTS A CHANNEL OF CIRRUS CLOUDS FROM NORTHERN IL STRETCHING WEST
THROUGH IOWA...THEN A MORE EXPANSIVE AREA OF CIRRUS CLOUDS ACROSS
THE SOUTHERN PLAINS INTO THE SOUTHERN ROCKIES. THE SOUTHERN ROCKIES
IS THE AREA THAT GUIDANCE HAS BEEN FOCUSED ON FOR THE DEVELOPMENT OF
A WEAK WAVE THAT WILL SLIDE ALONG THE FRONTAL BOUNDARY AND
OVERSPREAD CLOUDS AND LGT PRECIP TO PORTIONS OF THE GREAT LAKES MON
NGT.
CLOUD COVER WILL STEADILY SLIDE OVERHEAD THIS
EVENING/OVERNIGHT...WITH A FEW POCKETS OF CLEARING. DEEPER MOISTURE
WILL REMAIN WEST OF THE CWFA THROUGH THE OVERNIGHT...MAINLY OVER
IA/MO/KS/OK. WITH POTENTIALLY HIGH CLOUDS OVERHEAD SFC TEMPS SHOULD
BE ABLE TO RADIATE INTO THE MID/UPR 30S ACROSS THE REGION. SFC WINDS
SHOULD CONTINUE OVERNIGHT AROUND 10 MPH OR LESS...HOWEVER SHOULD BE
JUST ENOUGH TO PREVENT LARGE SCALE FOG DEVELOPMENT. A FEW PROTECTED
AREAS AND LOCATIONS CLOSEST TO STREAMS...MAY SEE PATCHY FOG DEVELOP.
THE OTHER AREAS THAT COULD SEE PATCHY FOG MAY BE THE FAR NORTHEAST
CORNER OF NORTHEAST IL...WITH A WEAK ONSHORE FLOW AND MARINE
MOISTURE BLEEDING INLAND A FEW MILES.
CONFIDENCE...HIGH.
MONDAY THROUGH TUESDAY...
ANTI-CYCLONIC FLOW IS PROGGED TO BE THE MAIN FEATURE FOR EARLY
WEEK...HOWEVER A WEAK FRONTAL BOUNDARY IS PROGGED TO PUSH EAST
ACROSS THE MISSISSIPPI VALLEY INTO THE GREAT LAKES MONDAY
NIGHT/EARLY TUESDAY. GUIDANCE HAS CONTINUED TO HINT THAT SOME
MOISTURE WILL ACCOMPANY THIS BOUNDARY...ALTHOUGH LOOKING UPSTREAM AT
CURRENT CONDITIONS IT APPEARS THE SCENARIO OF LIGHT PRECIP IS LOW
FOR MONDAY NIGHT/EARLY TUE. ANOTHER POTENTIAL LIMITING FACTOR IS
THAT THE EXPECTED DOWNSTREAM RIDGE MAY CONTINUE TO HOLD WITH
DIFFLUENT FLOW IN THE MID-LVLS...WHICH WOULD AID IN DRYING THE
MOISTURE AT THE MID-LVLS. LLVL FLOW MAY BACK SLIGHTLY TO THE
SOUTHEAST...WHICH COULD ALSO AID IN MOISTURE AVAILABILITY. FORCING
DOES NOT APPEAR TO BE VERY POTENT EITHER. MANY PLUMES SUGGEST A DRY
MON NGT/EARLY TUE AS WELL ACROSS THE CWFA. BASED ON THESE
AFOREMENTIONED ELEMENTS...HAVE OPTED TO REMOVE MENTION OF PRECIP
ACROSS THE CWFA FOR MON NGT/EARLY TUE...AND ADJUSTED ANY PRECIP TO
LOCATIONS FURTHER NORTH ACROSS WISC/LAKE MICHIGAN/LOWER MICHIGAN. IF
PRECIP DOES DEVELOP...IT APPEARS IT MAY END UP BEING SPRINKLES.
OVERALL EXPECT JUST CLOUDS TO BE ON THE INCREASE FROM THIS SYSTEM.
TEMPS BOTH DAYS WILL CONTINUE TO BE MILD WITH A THERMAL RIDGE OF 5
TO 7 DEG C MONDAY...AND 6 TO 8 DEG C TUESDAY. WITH OPTIMAL CONDS
EXPECTED BOTH DAYS...TEMPS SHOULD EASILY WARM INTO THE MID/UPR 50S.
FOR LOCATIONS ALONG AND SOUTH OF I-80 TEMPS COULD TOUCH 60 DEGREES
TUESDAY AFTERNOON. SEVERAL 2M TEMP PLUMES FOR THIS PERIOD ALSO
SUPPORT THIS MAX TEMP FORECAST. OVERNIGHT LOWS WILL ALSO BE
MILD...UPR 30S/LOW 40S.
CONFIDENCE...HIGH.
PRECIP CONFIDENCE...MEDIUM/HIGH.
WEDNESDAY...
ONE OF THE BUSIEST TRAVEL DAYS OF THE YEAR...AND IT APPEARS MOTHER
NATURE WILL COOPERATE AND PRODUCE OPTIMAL TRAVEL CONDITIONS FOR
NORTHERN IL/NORTHWEST IN. ANTI-CYCLONIC FLOW WILL PUSH BACK INTO THE
REGION AND ERODE THE CLOUDS TUE NGT/EARLY WED...WITH COULD ALLOW
TEMPS EARLY WED BEFORE SUNRISE TO DIP INTO THE LOW 30S. THEN A LARGE
DIURNAL CURVE IS EXPECTED FOR WED AFTERNOON. 850MB THERMAL RIDGE OF
7 TO 9 DEG C IS PROGGED TO SLIDE OVERHEAD FROM THE
WEST/SOUTHWEST...WITH LLVL FLOW TURNING SOUTH/SOUTHWEST. THE BEST
PRESSURE GRADIENT AND ADVECTION APPEARS TO BE DISPLACED TO THE
NORTHWEST/WEST OF THE CWFA...HOWEVER IT APPEARS TEMPS COULD EASILY
WARM TO 60 DEG ACROSS THE AREA. FOR AREAS ALONG AND WEST OF A
ROCKFORD/KANKAKEE LINE...TEMPS MAY PUSH TO 61 TO 63 DEG.
CONFIDENCE...HIGH.
THANKSGIVING THROUGH SATURDAY...
THE ANOMALOUS WARM/DRY PATTERN THAT HAS DOMINATED MUCH OF THE REGION
FOR THE PAST SEVERAL DAYS...MAY BE TRANSITIONING INTO A MORE ACTIVE
PATTERN. ABOVE NORMAL 500MB HEIGHTS WILL PERSIST THROUGH THUR...THEN
STEADILY WEAKEN INTO A SEMI-ZONAL FLOW AND POSSIBLY A TROUGH DIGGING
INTO THE UPPER MIDWEST/CENTRAL ROCKIES DEVELOPS. GUIDANCE BECOMES
RATHER NOISY IN THE EXTENDED PERIODS FROM FRI-SAT...WHICH IS
INDICATED BY THE ENVELOPE OF SOLUTIONS THAT THE ENSEMBLES PROG AS
WELL AS OPERATIONAL GFS/ECMWF. THE FIRST FEW PERIODS WILL CONTINUE
TO BE MILD WITH TEMPS NEAR 60 TO POSSIBLY THE LOW 60S IN THE
AFTERNOON FOR THANKSGIVING...HOWEVER THIS WILL CHANGE FOR FRI/SAT.
500MB TROUGH CONTINUES TO BE PROGGED BY OPERATIONAL SOLUTIONS AND
ANTI-CYCLONIC FLOW WILL DEPART TO THE SOUTHEAST. THIS WILL AID IN A
STRENGTHENING SOUTHWEST FLOW THUR NGT/FRI AS A FRONTAL BOUNDARY
BEGINS TO APPROACH THE REGION. 850MB THERMAL TROUGH OF -2 TO -5 DEG
C SHOULD ARRIVE ACROSS THE REGION MIDDAY FRI...THUS TEMPS FRI MAY
STRUGGLE TO WARM WITH POSSIBLY THE WARMEST TEMPS FOR THE DAY
OCCURRING IN THE MORNING. 500MB SPEED MAX PIVOTS EAST ACROSS THE
UPPER MIDWEST/NORTHERN GREAT LAKES...HOWEVER APPEARS TO BE MAINLY
MOISTURE STARVED. AT THIS POINT HAVE CONTINUED TO MENTION CHC
POPS...AND TEMPS SHOULD BE COOL ENOUGH TO PRODUCE A POSSIBLE RA/SN
MIX HOWEVER MOISTURE RAPIDLY PIVOTS NORTHEAST BY FRI AFTN/EVE THAT
THIS WOULD BE RESTRICTED TO THE LAKE ENVIRONMENT AND LOWER MICHIGAN.
THEN ANTI-CYCLONIC FLOW IS PROGGED TO BUILD BACK INTO THE
MIDWEST/GREAT LAKES REGION FOR THE REMAINDER OF THE WEEKEND AND
PROVIDE DRY WEATHER. IN ADDITION THE LONGER TERM MODELS CONTINUE TO
HINT THAT TEMPS MAY YET AGAIN PUSH BACK ABOVE NORMAL FOR THE SECOND
HALF OF THE WEEKEND AND POSSIBLY CONTINUE INTO EARLY THE FOLLOWING
WEEK.
CONFIDENCE...HIGH.
BEACHLER
&&
.CLIMATE...
321 AM CST
A SHIFT IN THE UPPER PATTERN WILL ALLOW SOME MODERATION OF
TEMPERATURES GOING INTO THE WEEKEND AND PREVAILING FOR SEVERAL DAYS
THEREAFTER. WHILE THE MODERATION WILL HELP OBSERVED TEMPERATURES TO
EXCEED DAILY NORMALS THE FACT THAT INCREASINGLY SHORTER DAYS AND
LOWERING SUN ANGLES RESULT IN THE NORMAL HIGH TEMPERATURE FALLING BY
1 DEGREE F ABOUT EVERY 2 DAYS. SO...IT IS THE COMBINATION OF THE
LOWERING NORMAL MAXIMUM TEMPERATURES ALONG WITH THE WARMING THAT
WILL RESULT IN DAYTIME TEMPERATURES TO CLIMB TO ABOVE NORMAL...WHICH
ARE NOW ONLY IN THE UPPER 40S AT MID NOVEMBER.
NORMALS...
CHICAGO ROCKFORD
MAX MIN MAX MIN
NOV 01 56 38 56 36
NOV 17 47 32 47 30
NOV 30 40 27 39 24
THIS UNUSUAL PATTERN WILL ALSO ALLOW HIGH TEMPERATURES ON
WEDNESDAY AND THURSDAY...THANSKGIVING...TO COME CLOSE TO THE
RECORD HIGH TEMPERATURES. WHILE FORECASTED HIGH TEMPERATURES ARE
CURRENTLY A FEW DEGREES COOLER THAN THE RECORDS...HERE ARE THE THE
MAX TEMPERATURE RECORDS FOR FOOD FOR THOUGHT:
CHICAGO ROCKFORD
NOV 21 72 1913 73 1913
NOV 22 69 1913 69 2010
TRS/JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* WEAK LAKE BREEZE MOVING INLAND TO ORD VC 22-23Z TIME-FRAME
BACKING WINDS SOMEWHAT FROM SSE TO SE FOR A PERIOD LATE
AFTERNOON-EARLY EVENING.
TRS
//DISCUSSION...UPDATED 18Z...
LATEST HI RES RUC AND HRR MODEL OUTPUT CONTINUE TO SUGGEST A WEAK
LAKE BREEZE...SUCH AS OCCURRED FRI AND SAT...IS TO DEVELOP AND
EVENTUALLY MOVE INLAND TO MDW AND ORD VICINITY 21-22Z TIME-FRAME.
RESULT IS THAT 5-10 KT SSE WINDS BACK A BIT TO SE-ESE FOR THE
LATE AFTERNOON. MARINE OBS SITES CURRENTLY SHOW A SE WIND
DIRECTION AT WAUKEGAN AND BURNHAM HARBORS WITH MESONET OBS
INDICATING LIGHT VARIABLE WINDS FROM JUST ASHORE TO A COUPLE MILES
INLAND SUGGESTING THE WEAK BOUNDARY IS ALONG THE SHORE AND LITTLE
RESISTANCE TO MOVING GRADUALLY INLAND AS CURRENT SMALL TEMPERATURE
DIFFERENTIAL BETWEEN LAND AND WATER CONTINUES TO INCREASE.
WITH LOSS OF HEATING TOWARDS DUSK AND DISSIPATION OF LAKE BREEZE
EARLY IN THE EVENING WINDS TO RETURN TO SSE-S. SPEEDS TO BE LESS
THAN 10 KT AS STRONGER SSW FLOW AHEAD OF AN APPROACHING COLD
FRONT/SURFACE TROUGH MOVING EAST ACROSS THE NORTHERN AND CENTRAL
PLAINS WILL BE DECOUPLED FROM THE SURFACE DURING THE NIGHT. AFTER
SUNRISE MONDAY MORNING STRONG...SHALLOW INVERSION WILL BEGIN TO BE
ERODED THOUGH WINDS AT TOP OF BOUNDARY LAYER DURING LATER MORNING
AND AFTERNOON ARE ONLY 14-17KT. EXPECT SOUTHERLY SURFACE WINDS TO
AVERAGE 8-10 KT AFTER SOME SURFACE HEATING AND MIXING WITH
POSSIBLE OCCASIONAL GUSTS OF 14-17KT.
EXPECT VFR CONDITIONS THROUGHOUT THE VALID TAFOR PERIOD WITH ONLY
SCT-BKN MID AND HIGH LEVEL CLOUDS.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE IN ORD WIND VEERING FM SSE TO SE DURING MID-
LATE AFTERNOON DUE TO WEAK LAKE BREEZE MOVING INLAND ACROSS
EXTREME NORTHEAST IL.
* HIGH CONFIDENCE REMAINDER OF FCST.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED12Z...
MONDAY NIGHT...VFR WITH SLIGHT CHANCE OF LIGHT RAIN.
TUESDAY AND WEDNESDAY...VFR.
THANKSGIVING...VFR WITH A CHANCE OF SHOWERS LATE.
FRIDAY AND SATURDAY...VFR.
LENNING
&&
.MARINE...
225 PM CST
A LARGE RIDGE OF HIGH PRESSURE EXTENDS FROM NOVA SCOTIA TO THE
LOWER MISSISSIPPI VALLEY.. THE RIDGE IS EXPECTED TO ONLY DRIFT
VERY SLOWLY EAST OVER THE NEXT SEVERAL DAYS WHILE GRADUALLY
WEAKENING. A TROUGH OF LOW PRESSURE WILL MOVE INTO THE DAKOTAS
TODAY...THEN INTO THE WESTERN GREAT LAKES MONDAY NIGHT AS IT
WEAKENS SLIGHTLY. THIS WILL KEEP GENERALLY SOUTHERLY WINDS OVER
THE LAKE UNTIL EARLY NEXT WEEK. AS THE TROUGH FURTHER WEAKENS TUESDAY
NIGHT AND AN ASSOCIATED WEAK COLD FRONT CROSSES LAKE MICHIGAN...
WINDS WILL SHIFT TO NORTHWESTERLY. HOWEVER...NO INCREASE IN WINDS
IS LIKELY AS A WEAK RIDGE OF HIGH PRESSURE WILL IMMEDIATELY FILL
IN BEHIND THE FRONT AND THERE IS NO SIGNIFICANTLY COLD AIR BEHIND
THE FRONT. ANOTHER LOW IS FORECAST TO DEVELOP OVER MONTANA ON
WEDNESDAY AND QUICKLY TRACK EASTWARD TO NEAR LAKE SUPERIOR BY
THURSDAY EVENING. THE LOW WILL THEN TURN NORTHEAST TOWARD SOUTHERN
JAMES BAY...DRAGGING A COLD FRONT ACROSS LAKE MICHIGAN LATE
THURSDAY NIGHT OR FRIDAY MORNING. THIS FRONT IS EXPECTED TO BE
MUCH STRONGER THAN THE PREVIOUS FRONT...BRINGING IN A MUCH COLDER
INFLUX OF COLDER AIR...AND WILL BRING STRENGTHENING NORTHWESTERLY
WINDS TO THE LAKE,
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
214 PM CST SUN NOV 18 2012
.DISCUSSION...
213 PM CST
TONIGHT...
ANTI-CYCLONIC FEATURE HAS BECOME STRETCHED OUT WITH A CENTER OVER
SOUTHEAST QUEBEC AND CONTINUES TO PROVIDE A MAIN INFLUENCE ACROSS
THE OHIO VALLEY/MID-MISSISSIPPI VALLEY. TO THE WEST OF THIS
INFLUENCE ACROSS PORTIONS OF THE UPPER MIDWEST/CENTRAL PLAINS...THE
PRESSURE GRADIENT IS TIGHTER AND RESULTING IN OCCASIONALLY GUSTY
SOUTH WINDS IN THOSE AREAS. VISIBLE IMAGERY EARLY THIS AFTERNOON
DEPICTS A CHANNEL OF CIRRUS CLOUDS FROM NORTHERN IL STRETCHING WEST
THROUGH IOWA...THEN A MORE EXPANSIVE AREA OF CIRRUS CLOUDS ACROSS
THE SOUTHERN PLAINS INTO THE SOUTHERN ROCKIES. THE SOUTHERN ROCKIES
IS THE AREA THAT GUIDANCE HAS BEEN FOCUSED ON FOR THE DEVELOPMENT OF
A WEAK WAVE THAT WILL SLIDE ALONG THE FRONTAL BOUNDARY AND
OVERSPREAD CLOUDS AND LGT PRECIP TO PORTIONS OF THE GREAT LAKES MON
NGT.
CLOUD COVER WILL STEADILY SLIDE OVERHEAD THIS
EVENING/OVERNIGHT...WITH A FEW POCKETS OF CLEARING. DEEPER MOISTURE
WILL REMAIN WEST OF THE CWFA THROUGH THE OVERNIGHT...MAINLY OVER
IA/MO/KS/OK. WITH POTENTIALLY HIGH CLOUDS OVERHEAD SFC TEMPS SHOULD
BE ABLE TO RADIATE INTO THE MID/UPR 30S ACROSS THE REGION. SFC WINDS
SHOULD CONTINUE OVERNIGHT AROUND 10 MPH OR LESS...HOWEVER SHOULD BE
JUST ENOUGH TO PREVENT LARGE SCALE FOG DEVELOPMENT. A FEW PROTECTED
AREAS AND LOCATIONS CLOSEST TO STREAMS...MAY SEE PATCHY FOG DEVELOP.
THE OTHER AREAS THAT COULD SEE PATCHY FOG MAY BE THE FAR NORTHEAST
CORNER OF NORTHEAST IL...WITH A WEAK ONSHORE FLOW AND MARINE
MOISTURE BLEEDING INLAND A FEW MILES.
CONFIDENCE...HIGH.
MONDAY THROUGH TUESDAY...
ANTI-CYCLONIC FLOW IS PROGGED TO BE THE MAIN FEATURE FOR EARLY
WEEK...HOWEVER A WEAK FRONTAL BOUNDARY IS PROGGED TO PUSH EAST
ACROSS THE MISSISSIPPI VALLEY INTO THE GREAT LAKES MONDAY
NIGHT/EARLY TUESDAY. GUIDANCE HAS CONTINUED TO HINT THAT SOME
MOISTURE WILL ACCOMPANY THIS BOUNDARY...ALTHOUGH LOOKING UPSTREAM AT
CURRENT CONDITIONS IT APPEARS THE SCENARIO OF LIGHT PRECIP IS LOW
FOR MONDAY NIGHT/EARLY TUE. ANOTHER POTENTIAL LIMITING FACTOR IS
THAT THE EXPECTED DOWNSTREAM RIDGE MAY CONTINUE TO HOLD WITH
DIFFLUENT FLOW IN THE MID-LVLS...WHICH WOULD AID IN DRYING THE
MOISTURE AT THE MID-LVLS. LLVL FLOW MAY BACK SLIGHTLY TO THE
SOUTHEAST...WHICH COULD ALSO AID IN MOISTURE AVAILABILITY. FORCING
DOES NOT APPEAR TO BE VERY POTENT EITHER. MANY PLUMES SUGGEST A DRY
MON NGT/EARLY TUE AS WELL ACROSS THE CWFA. BASED ON THESE
AFOREMENTIONED ELEMENTS...HAVE OPTED TO REMOVE MENTION OF PRECIP
ACROSS THE CWFA FOR MON NGT/EARLY TUE...AND ADJUSTED ANY PRECIP TO
LOCATIONS FURTHER NORTH ACROSS WISC/LAKE MICHIGAN/LOWER MICHIGAN. IF
PRECIP DOES DEVELOP...IT APPEARS IT MAY END UP BEING SPRINKLES.
OVERALL EXPECT JUST CLOUDS TO BE ON THE INCREASE FROM THIS SYSTEM.
TEMPS BOTH DAYS WILL CONTINUE TO BE MILD WITH A THERMAL RIDGE OF 5
TO 7 DEG C MONDAY...AND 6 TO 8 DEG C TUESDAY. WITH OPTIMAL CONDS
EXPECTED BOTH DAYS...TEMPS SHOULD EASILY WARM INTO THE MID/UPR 50S.
FOR LOCATIONS ALONG AND SOUTH OF I-80 TEMPS COULD TOUCH 60 DEGREES
TUESDAY AFTERNOON. SEVERAL 2M TEMP PLUMES FOR THIS PERIOD ALSO
SUPPORT THIS MAX TEMP FORECAST. OVERNIGHT LOWS WILL ALSO BE
MILD...UPR 30S/LOW 40S.
CONFIDENCE...HIGH.
PRECIP CONFIDENCE...MEDIUM/HIGH.
WEDNESDAY...
ONE OF THE BUSIEST TRAVEL DAYS OF THE YEAR...AND IT APPEARS MOTHER
NATURE WILL COOPERATE AND PRODUCE OPTIMAL TRAVEL CONDITIONS FOR
NORTHERN IL/NORTHWEST IN. ANTI-CYCLONIC FLOW WILL PUSH BACK INTO THE
REGION AND ERODE THE CLOUDS TUE NGT/EARLY WED...WITH COULD ALLOW
TEMPS EARLY WED BEFORE SUNRISE TO DIP INTO THE LOW 30S. THEN A LARGE
DIURNAL CURVE IS EXPECTED FOR WED AFTERNOON. 850MB THERMAL RIDGE OF
7 TO 9 DEG C IS PROGGED TO SLIDE OVERHEAD FROM THE
WEST/SOUTHWEST...WITH LLVL FLOW TURNING SOUTH/SOUTHWEST. THE BEST
PRESSURE GRADIENT AND ADVECTION APPEARS TO BE DISPLACED TO THE
NORTHWEST/WEST OF THE CWFA...HOWEVER IT APPEARS TEMPS COULD EASILY
WARM TO 60 DEG ACROSS THE AREA. FOR AREAS ALONG AND WEST OF A
ROCKFORD/KANKAKEE LINE...TEMPS MAY PUSH TO 61 TO 63 DEG.
CONFIDENCE...HIGH.
THANKSGIVING THROUGH SATURDAY...
THE ANOMALOUS WARM/DRY PATTERN THAT HAS DOMINATED MUCH OF THE REGION
FOR THE PAST SEVERAL DAYS...MAY BE TRANSITIONING INTO A MORE ACTIVE
PATTERN. ABOVE NORMAL 500MB HEIGHTS WILL PERSIST THROUGH THUR...THEN
STEADILY WEAKEN INTO A SEMI-ZONAL FLOW AND POSSIBLY A TROUGH DIGGING
INTO THE UPPER MIDWEST/CENTRAL ROCKIES DEVELOPS. GUIDANCE BECOMES
RATHER NOISY IN THE EXTENDED PERIODS FROM FRI-SAT...WHICH IS
INDICATED BY THE ENVELOPE OF SOLUTIONS THAT THE ENSEMBLES PROG AS
WELL AS OPERATIONAL GFS/ECMWF. THE FIRST FEW PERIODS WILL CONTINUE
TO BE MILD WITH TEMPS NEAR 60 TO POSSIBLY THE LOW 60S IN THE
AFTERNOON FOR THANKSGIVING...HOWEVER THIS WILL CHANGE FOR FRI/SAT.
500MB TROUGH CONTINUES TO BE PROGGED BY OPERATIONAL SOLUTIONS AND
ANTI-CYCLONIC FLOW WILL DEPART TO THE SOUTHEAST. THIS WILL AID IN A
STRENGTHENING SOUTHWEST FLOW THUR NGT/FRI AS A FRONTAL BOUNDARY
BEGINS TO APPROACH THE REGION. 850MB THERMAL TROUGH OF -2 TO -5 DEG
C SHOULD ARRIVE ACROSS THE REGION MIDDAY FRI...THUS TEMPS FRI MAY
STRUGGLE TO WARM WITH POSSIBLY THE WARMEST TEMPS FOR THE DAY
OCCURRING IN THE MORNING. 500MB SPEED MAX PIVOTS EAST ACROSS THE
UPPER MIDWEST/NORTHERN GREAT LAKES...HOWEVER APPEARS TO BE MAINLY
MOISTURE STARVED. AT THIS POINT HAVE CONTINUED TO MENTION CHC
POPS...AND TEMPS SHOULD BE COOL ENOUGH TO PRODUCE A POSSIBLE RA/SN
MIX HOWEVER MOISTURE RAPIDLY PIVOTS NORTHEAST BY FRI AFTN/EVE THAT
THIS WOULD BE RESTRICTED TO THE LAKE ENVIRONMENT AND LOWER MICHIGAN.
THEN ANTI-CYCLONIC FLOW IS PROGGED TO BUILD BACK INTO THE
MIDWEST/GREAT LAKES REGION FOR THE REMAINDER OF THE WEEKEND AND
PROVIDE DRY WEATHER. IN ADDITION THE LONGER TERM MODELS CONTINUE TO
HINT THAT TEMPS MAY YET AGAIN PUSH BACK ABOVE NORMAL FOR THE SECOND
HALF OF THE WEEKEND AND POSSIBLY CONTINUE INTO EARLY THE FOLLOWING
WEEK.
CONFIDENCE...HIGH.
BEACHLER
&&
.CLIMATE...
321 AM CST
A SHIFT IN THE UPPER PATTERN WILL ALLOW SOME MODERATION OF
TEMPERATURES GOING INTO THE WEEKEND AND PREVAILING FOR SEVERAL DAYS
THEREAFTER. WHILE THE MODERATION WILL HELP OBSERVED TEMPERATURES TO
EXCEED DAILY NORMALS THE FACT THAT INCREASINGLY SHORTER DAYS AND
LOWERING SUN ANGLES RESULT IN THE NORMAL HIGH TEMPERATURE FALLING BY
1 DEGREE F ABOUT EVERY 2 DAYS. SO...IT IS THE COMBINATION OF THE
LOWERING NORMAL MAXIMUM TEMPERATURES ALONG WITH THE WARMING THAT
WILL RESULT IN DAYTIME TEMPERATURES TO CLIMB TO ABOVE NORMAL...WHICH
ARE NOW ONLY IN THE UPPER 40S AT MID NOVEMBER.
NORMALS...
CHICAGO ROCKFORD
MAX MIN MAX MIN
NOV 01 56 38 56 36
NOV 17 47 32 47 30
NOV 30 40 27 39 24
THIS UNUSUAL PATTERN WILL ALSO ALLOW HIGH TEMPERATURES ON
WEDNESDAY AND THURSDAY...THANSKGIVING...TO COME CLOSE TO THE
RECORD HIGH TEMPERATURES. WHILE FORECASTED HIGH TEMPERATURES ARE
CURRENTLY A FEW DEGREES COOLER THAN THE RECORDS...HERE ARE THE THE
MAX TEMPERATURE RECORDS FOR FOOD FOR THOUGHT:
CHICAGO ROCKFORD
NOV 21 72 1913 73 1913
NOV 22 69 1913 69 2010
TRS/JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* WEAK LAKE BREEZE MOVING INLAND TO ORD VC 22-23Z TIME-FRAME
BACKING WINDS SOMEWHAT FROM SSE TO SE FOR A PERIOD LATE
AFTERNOON-EARLY EVENING.
TRS
//DISCUSSION...UPDATED 18Z...
LATEST HI RES RUC AND HRR MODEL OUTPUT CONTINUE TO SUGGEST A WEAK
LAKE BREEZE...SUCH AS OCCURRED FRI AND SAT...IS TO DEVELOP AND
EVENTUALLY MOVE INLAND TO MDW AND ORD VICINITY 21-22Z TIME-FRAME.
RESULT IS THAT 5-10 KT SSE WINDS BACK A BIT TO SE-ESE FOR THE
LATE AFTERNOON. MARINE OBS SITES CURRENTLY SHOW A SE WIND
DIRECTION AT WAUKEGAN AND BURNHAM HARBORS WITH MESONET OBS
INDICATING LIGHT VARIABLE WINDS FROM JUST ASHORE TO A COUPLE MILES
INLAND SUGGESTING THE WEAK BOUNDARY IS ALONG THE SHORE AND LITTLE
RESISTANCE TO MOVING GRADUALLY INLAND AS CURRENT SMALL TEMPERATURE
DIFFERENTIAL BETWEEN LAND AND WATER CONTINUES TO INCREASE.
WITH LOSS OF HEATING TOWARDS DUSK AND DISSIPATION OF LAKE BREEZE
EARLY IN THE EVENING WINDS TO RETURN TO SSE-S. SPEEDS TO BE LESS
THAN 10 KT AS STRONGER SSW FLOW AHEAD OF AN APPROACHING COLD
FRONT/SURFACE TROUGH MOVING EAST ACROSS THE NORTHERN AND CENTRAL
PLAINS WILL BE DECOUPLED FROM THE SURFACE DURING THE NIGHT. AFTER
SUNRISE MONDAY MORNING STRONG...SHALLOW INVERSION WILL BEGIN TO BE
ERODED THOUGH WINDS AT TOP OF BOUNDARY LAYER DURING LATER MORNING
AND AFTERNOON ARE ONLY 14-17KT. EXPECT SOUTHERLY SURFACE WINDS TO
AVERAGE 8-10 KT AFTER SOME SURFACE HEATING AND MIXING WITH
POSSIBLE OCCASIONAL GUSTS OF 14-17KT.
EXPECT VFR CONDITIONS THROUGHOUT THE VALID TAFOR PERIOD WITH ONLY
SCT-BKN MID AND HIGH LEVEL CLOUDS.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE IN ORD WIND VEERING FM SSE TO SE DURING MID-
LATE AFTERNOON DUE TO WEAK LAKE BREEZE MOVING INLAND ACROSS
EXTREME NORTHEAST IL.
* HIGH CONFIDENCE REMAINDER OF FCST.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED12Z...
MONDAY NIGHT...VFR WITH SLIGHT CHANCE OF LIGHT RAIN.
TUESDAY AND WEDNESDAY...VFR.
THANKSGIVING...VFR WITH A CHANCE OF SHOWERS LATE.
FRIDAY AND SATURDAY...VFR.
LENNING
&&
.MARINE...
249 AM CST
A BROAD RIDGE ACROSS THE NORTHEASTERN UNITED STATES WILL WEAKEN
SOMEWHAT BUT MOVE VERY LITTLE THROUGH THE FIRST HALF OF THE WEEK.
THE LOCATION OF THIS FEATURE WILL SUPPORT CONTINUED SOUTHERLY FLOW
ACROSS THE LAKE. THE LACK OF A STRONG PRESSURE GRADIENT WILL
GENERALLY KEEP WINDS AND WAVES BELOW LEVELS THAT WOULD POSE
HAZARDS. THE EXCEPTION WOULD BE ALONG THE FAR NORTHERN SHORE AT
THE END OF THE LONG FETCH WHERE SMALL CRAFT HEADLINES ARE IN
EFFECT. EVEN THE APPROACH OF A TROUGH FROM THE WEST TOWARD MIDWEEK
WILL NOT BE ENOUGH TO BOOST WINDS...SINCE BY THAT TIME THE RIDGE
TO THE EAST WILL HAVE WEAKENED SOMEWHAT AND MOVED A BIT FARTHER
AWAY TOWARD THE ATLANTIC COAST.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
205 PM CST SUN NOV 18 2012
.DISCUSSION...
321 AM CST
SYNOPSIS...SOME THINGS BECOME CLEARER WHILE OTHER PARTS OF THE
FORECAST BECOME MORE MUDDLED. OVERALL A GRADUAL WARMING PATTERN IS
STILL EXPECTED THROUGH MONDAY...WITH TEMPERATURES WELL ABOVE NORMAL
WEDNESDAY AND THANKSGIVING. NO SIGNIFICANT PRECIP IS EXPECTED.
TODAY THROUGH MONDAY...
HIGH PRESSURE CURRENTLY CENTERED OVER SOUTHEASTERN QUEBEC/UPPER NEW
ENGLAND STRETCHES THROUGH THE MISSISSIPPI RIVER VALLEY. THE HIGH
WILL REMAINED CENTERED THERE THROUGH EARLY NEXT WEEK WITH RELATIVELY
QUIET WEATHER EXPECTED LOCALLY. TEMPS WILL BE AROUND 60 TODAY WITH
CLEAR SKIES AND SOUTHERLY FLOW.
CLOUDS INCREASE TOMORROW AS A THROUGH OF LOW PRESSURE/WEAK COLD
FRONT APPROACH FROM THE WEST. AS SUCH WENT WITH TEMPS A DEGREE OR
TWO COOLER ON MONDAY...BUT STILL WELL ABOVE AVERAGE.
MONDAY NIGHT AND TUESDAY...
LOW PRESSURE CURRENTLY OVER WESTERN BRITISH COLUMBIA WILL PUSH
EASTWARD THROUGH CANADA...AND MODELS CONTINUE TO PUSH THE LOW
FURTHER NORTH. THE LOWS COLD FRONT/LOW PRESSURE TROUGH WILL PASS
THROUGH THE AREA. FORCING REMAINS WEAK ALONG THE COLD FRONT
THEREFORE EXPECTING A FEW HUNDREDTHS AT BEST MONDAY EVENING THROUGH
MONDAY NIGHT. GUIDANCE INDICATES THE TROUGH/COLD FRONT WEAKENS AS
IT APPROACHES THE CWA SO THE BEST CHANCE OF PRECIP LOOKS TO BE
OVER THE WESTERN AND NORTHERN PORTIONS OF THE CWA MONDAY NIGHT.
AND BY BEST CHANCE I MEAN BEST VERY VERY SLIGHT CHANCE.
PRECIP MOVES OUT BY TUESDAY MORNING AND HIGH PRESSURE QUICKLY MOVES
OVER THE CWA. THINKING TEMPS WILL ONCE AGAIN BE A DEGREE OR TWO
HIGHER THAN MONDAY DUE TO WEAK UPPER LEVEL WAA AND CLEARING SKIES.
WEDNESDAY AND THANKSGIVING...
SOUTHERLY FLOW RETURNS IN FORCE WEDNESDAY AS THE HIGH PRESSURE
SLIDES TOWARD THE SOUTHEAST US. 850 HPA TEMPS SOAR TO AROUND 10C
WEDNESDAY AND THANKSGIVING...THEREFORE WENT A FEW DEGREES ABOVE
ALL-BLEND GUIDANCE ONCE AGAIN. ITS LOOKING LIKE THURSDAY MAY BE THE
WARMER OF THE TWO DAYS WITH TEMPS BOTH DAYS AT OR ABOVE 60 DEGREES.
MOST PEOPLE WOULD AGREE THAT IS SOMETHING TO BE THANKFUL ABOUT.
EXTENDED...THANKSGIVING NIGHT THROUGH SATURDAY...
WHAT HAPPENS THANKSGIVING EVENING/NIGHT IS THE BIG FORECAST
QUESTION. THE GEM AND ECMWF INDICATE LOW PRESSURE WILL MOVE FROM
THE CENTRAL PLAINS THROUGH WISCONSIN WITH ITS COLD FRONT MOVING
THROUGH THE CWA THANKSGIVING NIGHT. THE GFS ON THE OTHER HAND HAS
THE LOW MOVING MUCH FARTHER NORTH OVER CENTRAL ONTARIO AND QUEBEC.
THE GFS SOLUTION IS ALSO MUCH FASTER THAN THE OTHER TWO SOLUTIONS.
SINCE THE GEM AND ECMWF ARE MERGING TOWARD EACH OTHER...LEANING
TOWARD THAT SOLUTION. THERE ARE ENOUGH DIFFERENCES IN THE SOLUTIONS
THAT DECIDED TO NOT MAKE ANY ADJUSTMENTS TO THE ALL-BLEND TEMPS OR
SLIGHT CHANCE POP FORECAST.
THAT BEING SAID...IF THE ECMWF SOLUTION IS TO BE BELIEVED...A
SIGNIFICANT TEMPERATURE DROP WILL BE EXPECTED BETWEEN THANKSGIVING
AND FRIDAY. BY FRIDAY AFTERNOON 850 HPA TEMPS ARE WELL BELOW ZERO.
THE GFS FEATURES A MUCH WEAKER COLD AIR PUSH SINCE ITS UPPER LEVEL
PATTERN IS VERY ZONAL. NONETHELESS IT DOES FEATURE 850 HPA TEMPS
BELOW ZERO MOVING OVERHEAD SATURDAY.
JEE
&&
.CLIMATE...
321 AM CST
A SHIFT IN THE UPPER PATTERN WILL ALLOW SOME MODERATION OF
TEMPERATURES GOING INTO THE WEEKEND AND PREVAILING FOR SEVERAL DAYS
THEREAFTER. WHILE THE MODERATION WILL HELP OBSERVED TEMPERATURES TO
EXCEED DAILY NORMALS THE FACT THAT INCREASINGLY SHORTER DAYS AND
LOWERING SUN ANGLES RESULT IN THE NORMAL HIGH TEMPERATURE FALLING BY
1 DEGREE F ABOUT EVERY 2 DAYS. SO...IT IS THE COMBINATION OF THE
LOWERING NORMAL MAXIMUM TEMPERATURES ALONG WITH THE WARMING THAT
WILL RESULT IN DAYTIME TEMPERATURES TO CLIMB TO ABOVE NORMAL...WHICH
ARE NOW ONLY IN THE UPPER 40S AT MID NOVEMBER.
NORMALS...
CHICAGO ROCKFORD
MAX MIN MAX MIN
NOV 01 56 38 56 36
NOV 17 47 32 47 30
NOV 30 40 27 39 24
THIS UNUSUAL PATTERN WILL ALSO ALLOW HIGH TEMPERATURES ON
WEDNESDAY AND THURSDAY...THANSKGIVING...TO COME CLOSE TO THE
RECORD HIGH TEMPERATURES. WHILE FORECASTED HIGH TEMPERATURES ARE
CURRENTLY A FEW DEGREES COOLER THAN THE RECORDS...HERE ARE THE THE
MAX TEMPERATURE RECORDS FOR FOOD FOR THOUGHT:
CHICAGO ROCKFORD
NOV 21 72 1913 73 1913
NOV 22 69 1913 69 2010
TRS/JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* WEAK LAKE BREEZE MOVING INLAND TO ORD VC 22-23Z TIME-FRAME
BACKING WINDS SOMEWHAT FROM SSE TO SE FOR A PERIOD LATE
AFTERNOON-EARLY EVENING.
TRS
//DISCUSSION...UPDATED 18Z...
LATEST HI RES RUC AND HRR MODEL OUTPUT CONTINUE TO SUGGEST A WEAK
LAKE BREEZE...SUCH AS OCCURRED FRI AND SAT...IS TO DEVELOP AND
EVENTUALLY MOVE INLAND TO MDW AND ORD VICINITY 21-22Z TIME-FRAME.
RESULT IS THAT 5-10 KT SSE WINDS BACK A BIT TO SE-ESE FOR THE
LATE AFTERNOON. MARINE OBS SITES CURRENTLY SHOW A SE WIND
DIRECTION AT WAUKEGAN AND BURNHAM HARBORS WITH MESONET OBS
INDICATING LIGHT VARIABLE WINDS FROM JUST ASHORE TO A COUPLE MILES
INLAND SUGGESTING THE WEAK BOUNDARY IS ALONG THE SHORE AND LITTLE
RESISTANCE TO MOVING GRADUALLY INLAND AS CURRENT SMALL TEMPERATURE
DIFFERENTIAL BETWEEN LAND AND WATER CONTINUES TO INCREASE.
WITH LOSS OF HEATING TOWARDS DUSK AND DISSIPATION OF LAKE BREEZE
EARLY IN THE EVENING WINDS TO RETURN TO SSE-S. SPEEDS TO BE LESS
THAN 10 KT AS STRONGER SSW FLOW AHEAD OF AN APPROACHING COLD
FRONT/SURFACE TROUGH MOVING EAST ACROSS THE NORTHERN AND CENTRAL
PLAINS WILL BE DECOUPLED FROM THE SURFACE DURING THE NIGHT. AFTER
SUNRISE MONDAY MORNING STRONG...SHALLOW INVERSION WILL BEGIN TO BE
ERODED THOUGH WINDS AT TOP OF BOUNDARY LAYER DURING LATER MORNING
AND AFTERNOON ARE ONLY 14-17KT. EXPECT SOUTHERLY SURFACE WINDS TO
AVERAGE 8-10 KT AFTER SOME SURFACE HEATING AND MIXING WITH
POSSIBLE OCCASIONAL GUSTS OF 14-17KT.
EXPECT VFR CONDITIONS THROUGHOUT THE VALID TAFOR PERIOD WITH ONLY
SCT-BKN MID AND HIGH LEVEL CLOUDS.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE IN ORD WIND VEERING FM SSE TO SE DURING MID-
LATE AFTERNOON DUE TO WEAK LAKE BREEZE MOVING INLAND ACROSS
EXTREME NORTHEAST IL.
* HIGH CONFIDENCE REMAINDER OF FCST.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED12Z...
MONDAY NIGHT...VFR WITH SLIGHT CHANCE OF LIGHT RAIN.
TUESDAY AND WEDNESDAY...VFR.
THANKSGIVING...VFR WITH A CHANCE OF SHOWERS LATE.
FRIDAY AND SATURDAY...VFR.
LENNING
&&
.MARINE...
249 AM CST
A BROAD RIDGE ACROSS THE NORTHEASTERN UNITED STATES WILL WEAKEN
SOMEWHAT BUT MOVE VERY LITTLE THROUGH THE FIRST HALF OF THE WEEK.
THE LOCATION OF THIS FEATURE WILL SUPPORT CONTINUED SOUTHERLY FLOW
ACROSS THE LAKE. THE LACK OF A STRONG PRESSURE GRADIENT WILL
GENERALLY KEEP WINDS AND WAVES BELOW LEVELS THAT WOULD POSE
HAZARDS. THE EXCEPTION WOULD BE ALONG THE FAR NORTHERN SHORE AT
THE END OF THE LONG FETCH WHERE SMALL CRAFT HEADLINES ARE IN
EFFECT. EVEN THE APPROACH OF A TROUGH FROM THE WEST TOWARD MIDWEEK
WILL NOT BE ENOUGH TO BOOST WINDS...SINCE BY THAT TIME THE RIDGE
TO THE EAST WILL HAVE WEAKENED SOMEWHAT AND MOVED A BIT FARTHER
AWAY TOWARD THE ATLANTIC COAST.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1201 PM CST SUN NOV 18 2012
.DISCUSSION...
321 AM CST
SYNOPSIS...SOME THINGS BECOME CLEARER WHILE OTHER PARTS OF THE
FORECAST BECOME MORE MUDDLED. OVERALL A GRADUAL WARMING PATTERN IS
STILL EXPECTED THROUGH MONDAY...WITH TEMPERATURES WELL ABOVE NORMAL
WEDNESDAY AND THANKSGIVING. NO SIGNIFICANT PRECIP IS EXPECTED.
TODAY THROUGH MONDAY...
HIGH PRESSURE CURRENTLY CENTERED OVER SOUTHEASTERN QUEBEC/UPPER NEW
ENGLAND STRETCHES THROUGH THE MISSISSIPPI RIVER VALLEY. THE HIGH
WILL REMAINED CENTERED THERE THROUGH EARLY NEXT WEEK WITH RELATIVELY
QUIET WEATHER EXPECTED LOCALLY. TEMPS WILL BE AROUND 60 TODAY WITH
CLEAR SKIES AND SOUTHERLY FLOW.
CLOUDS INCREASE TOMORROW AS A THROUGH OF LOW PRESSURE/WEAK COLD
FRONT APPROACH FROM THE WEST. AS SUCH WENT WITH TEMPS A DEGREE OR
TWO COOLER ON MONDAY...BUT STILL WELL ABOVE AVERAGE.
MONDAY NIGHT AND TUESDAY...
LOW PRESSURE CURRENTLY OVER WESTERN BRITISH COLUMBIA WILL PUSH
EASTWARD THROUGH CANADA...AND MODELS CONTINUE TO PUSH THE LOW
FURTHER NORTH. THE LOWS COLD FRONT/LOW PRESSURE TROUGH WILL PASS
THROUGH THE AREA. FORCING REMAINS WEAK ALONG THE COLD FRONT
THEREFORE EXPECTING A FEW HUNDREDTHS AT BEST MONDAY EVENING THROUGH
MONDAY NIGHT. GUIDANCE INDICATES THE TROUGH/COLD FRONT WEAKENS AS
IT APPROACHES THE CWA SO THE BEST CHANCE OF PRECIP LOOKS TO BE
OVER THE WESTERN AND NORTHERN PORTIONS OF THE CWA MONDAY NIGHT.
AND BY BEST CHANCE I MEAN BEST VERY VERY SLIGHT CHANCE.
PRECIP MOVES OUT BY TUESDAY MORNING AND HIGH PRESSURE QUICKLY MOVES
OVER THE CWA. THINKING TEMPS WILL ONCE AGAIN BE A DEGREE OR TWO
HIGHER THAN MONDAY DUE TO WEAK UPPER LEVEL WAA AND CLEARING SKIES.
WEDNESDAY AND THANKSGIVING...
SOUTHERLY FLOW RETURNS IN FORCE WEDNESDAY AS THE HIGH PRESSURE
SLIDES TOWARD THE SOUTHEAST US. 850 HPA TEMPS SOAR TO AROUND 10C
WEDNESDAY AND THANKSGIVING...THEREFORE WENT A FEW DEGREES ABOVE
ALL-BLEND GUIDANCE ONCE AGAIN. ITS LOOKING LIKE THURSDAY MAY BE THE
WARMER OF THE TWO DAYS WITH TEMPS BOTH DAYS AT OR ABOVE 60 DEGREES.
MOST PEOPLE WOULD AGREE THAT IS SOMETHING TO BE THANKFUL ABOUT.
EXTENDED...THANKSGIVING NIGHT THROUGH SATURDAY...
WHAT HAPPENS THANKSGIVING EVENING/NIGHT IS THE BIG FORECAST
QUESTION. THE GEM AND ECMWF INDICATE LOW PRESSURE WILL MOVE FROM
THE CENTRAL PLAINS THROUGH WISCONSIN WITH ITS COLD FRONT MOVING
THROUGH THE CWA THANKSGIVING NIGHT. THE GFS ON THE OTHER HAND HAS
THE LOW MOVING MUCH FARTHER NORTH OVER CENTRAL ONTARIO AND QUEBEC.
THE GFS SOLUTION IS ALSO MUCH FASTER THAN THE OTHER TWO SOLUTIONS.
SINCE THE GEM AND ECMWF ARE MERGING TOWARD EACH OTHER...LEANING
TOWARD THAT SOLUTION. THERE ARE ENOUGH DIFFERENCES IN THE SOLUTIONS
THAT DECIDED TO NOT MAKE ANY ADJUSTMENTS TO THE ALL-BLEND TEMPS OR
SLIGHT CHANCE POP FORECAST.
THAT BEING SAID...IF THE ECMWF SOLUTION IS TO BE BELIEVED...A
SIGNIFICANT TEMPERATURE DROP WILL BE EXPECTED BETWEEN THANKSGIVING
AND FRIDAY. BY FRIDAY AFTERNOON 850 HPA TEMPS ARE WELL BELOW ZERO.
THE GFS FEATURES A MUCH WEAKER COLD AIR PUSH SINCE ITS UPPER LEVEL
PATTERN IS VERY ZONAL. NONETHELESS IT DOES FEATURE 850 HPA TEMPS
BELOW ZERO MOVING OVERHEAD SATURDAY.
JEE
&&
.CLIMATE...
321 AM CST
A SHIFT IN THE UPPER PATTERN WILL ALLOW SOME MODERATION OF
TEMPERATURES GOING INTO THE WEEKEND AND PREVAILING FOR SEVERAL DAYS
THEREAFTER. WHILE THE MODERATION WILL HELP OBSERVED TEMPERATURES TO
EXCEED DAILY NORMALS THE FACT THAT INCREASINGLY SHORTER DAYS AND
LOWERING SUN ANGLES RESULT IN THE NORMAL HIGH TEMPERATURE FALLING BY
1 DEGREE F ABOUT EVERY 2 DAYS. SO...IT IS THE COMBINATION OF THE
LOWERING NORMAL MAXIMUM TEMPERATURES ALONG WITH THE WARMING THAT
WILL RESULT IN DAYTIME TEMPERATURES TO CLIMB TO ABOVE NORMAL...WHICH
ARE NOW ONLY IN THE UPPER 40S AT MID NOVEMBER.
NORMALS...
CHICAGO ROCKFORD
MAX MIN MAX MIN
NOV 01 56 38 56 36
NOV 17 47 32 47 30
NOV 30 40 27 39 24
THIS UNUSUAL PATTERN WILL ALSO ALLOW HIGH TEMPERATURES ON
WEDNESDAY AND THURSDAY...THANSKGIVING...TO COME CLOSE TO THE
RECORD HIGH TEMPERATURES. WHILE FORECASTED HIGH TEMPERATURES ARE
CURRENTLY A FEW DEGREES COOLER THAN THE RECORDS...HERE ARE THE THE
MAX TEMPERATURE RECORDS FOR FOOD FOR THOUGHT:
CHICAGO ROCKFORD
NOV 21 72 1913 73 1913
NOV 22 69 1913 69 2010
TRS/JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* WEAK LAKE BREEZE MOVING INLAND TO MDW AND ORD VC 21-22Z TIME-FRAME
BACKING WINDS SOMEWHAT FROM SSE TO SE.
TRS
//DISCUSSION...UPDATED 18Z...
LATEST HI RES RUC AND HRR MODEL OUTPUT CONTINUE TO SUGGEST A WEAK
LAKE BREEZE...SUCH AS OCCURRED FRI AND SAT...IS TO DEVELOP AND
EVENTUALLY MOVE INLAND TO MDW AND ORD VICINITY 21-22Z TIME-FRAME.
RESULT IS THAT 5-10 KT SSE WINDS BACK A BIT TO SE-ESE FOR THE
LATE AFTERNOON. MARINE OBS SITES CURRENTLY SHOW A SE WIND
DIRECTION AT WAUKEGAN AND BURNHAM HARBORS WITH MESONET OBS
INDICATING LIGHT VARIABLE WINDS FROM JUST ASHORE TO A COUPLE MILES
INLAND SUGGESTING THE WEAK BOUNDARY IS ALONG THE SHORE AND LITTLE
RESISTANCE TO MOVING GRADUALLY INLAND AS CURRENT SMALL TEMPERATURE
DIFFERENTIAL BETWEEN LAND AND WATER CONTINUES TO INCREASE.
WITH LOSS OF HEATING TOWARDS DUSK AND DISSIPATION OF LAKE BREEZE
EARLY IN THE EVENING WINDS TO RETURN TO SSE-S. SPEEDS TO BE LESS
THAN 10 KT AS STRONGER SSW FLOW AHEAD OF AN APPROACHING COLD
FRONT/SURFACE TROUGH MOVING EAST ACROSS THE NORTHERN AND CENTRAL
PLAINS WILL BE DECOUPLED FROM THE SURFACE DURING THE NIGHT. AFTER
SUNRISE MONDAY MORNING STRONG...SHALLOW INVERSION WILL BEGIN TO BE
ERODED THOUGH WINDS AT TOP OF BOUNDARY LAYER DURING LATER MORNING
AND AFTERNOON ARE ONLY 14-17KT. EXPECT SOUTHERLY SURFACE WINDS TO
AVERAGE 8-10 KT AFTER SOME SURFACE HEATING AND MIXING WITH
POSSIBLE OCCASIONAL GUSTS OF 14-17KT.
EXPECT VFR CONDITIONS THROUGHOUT THE VALID TAFOR PERIOD WITH ONLY
SCT-BKN MID AND HIGH LEVEL CLOUDS.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE ON WIND VEERING FM SSE TO SE AND ESE DURING
MID AFTERNOON DUE TO WEAK LAKE BREEZE MOVING INLAND.
* HIGH CONFIDENCE REMAINDER OF FCST.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED12Z...
MONDAY NIGHT...VFR WITH SLIGHT CHANCE OF LIGHT RAIN.
TUESDAY AND WEDNESDAY...VFR.
THANKSGIVING...VFR WITH A CHANCE OF SHOWERS LATE.
FRIDAY AND SATURDAY...VFR.
LENNING
&&
.MARINE...
249 AM CST
A BROAD RIDGE ACROSS THE NORTHEASTERN UNITED STATES WILL WEAKEN
SOMEWHAT BUT MOVE VERY LITTLE THROUGH THE FIRST HALF OF THE WEEK.
THE LOCATION OF THIS FEATURE WILL SUPPORT CONTINUED SOUTHERLY FLOW
ACROSS THE LAKE. THE LACK OF A STRONG PRESSURE GRADIENT WILL
GENERALLY KEEP WINDS AND WAVES BELOW LEVELS THAT WOULD POSE
HAZARDS. THE EXCEPTION WOULD BE ALONG THE FAR NORTHERN SHORE AT
THE END OF THE LONG FETCH WHERE SMALL CRAFT HEADLINES ARE IN
EFFECT. EVEN THE APPROACH OF A TROUGH FROM THE WEST TOWARD MIDWEEK
WILL NOT BE ENOUGH TO BOOST WINDS...SINCE BY THAT TIME THE RIDGE
TO THE EAST WILL HAVE WEAKENED SOMEWHAT AND MOVED A BIT FARTHER
AWAY TOWARD THE ATLANTIC COAST.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1045 AM CST SUN NOV 18 2012
.DISCUSSION...
ISSUED 1045 AM CST SUN NOV 18 2012
FORECAST LOOKS ON TRACK AGAIN TODAY WITH YET ANOTHER NICE FALL DAY
UNFOLDING. MAIN UPDATE IS FOR QUICKER RISE IN THE HOURLY TEMPS
THIS MORNING INTO MIDDAY. AMPLE SUNSHINE TODAY AS THIN CIRRUS
CLOUDS SPREAD EAST INTO CENTRAL IL. HIGHS IN THE UPPER 50S AND
LOWER 60S WITH SSE WINDS 5 TO 10 MPH.
LATE MORNING SURFACE MAP SHOWS STRONG 1041 MB HIGH PRESSURE OVER
NEW ENGLAND AND RIDGING SW INTO THE MID MS VALLEY. ALOFT AN UPPER
LEVEL TROF WAS ALONG THE WEST COAST WTIH UPPER LEVEL RIDGE OVER
THE OH/TN VALLEYS WHICH PLACES IL IN A SW FLOW ALOFT. LIGHT
FOG/HAZE DISSIPATE BY MID MORNING LEAVING SUNNY SKIES THIS MORNING.
TEMPS WERE IN THE UPPER 40S AND LOWER 50S AT 1030 AM WITH SSE
WINDS NEAR 8 MPH OR LESS. DEWPOINTS WERE IN THE MIDDLE 30S.
MODELS SLOWLY WEAKEN HIGH PRESSURE RIDGE INTO MON AS IT STAYS OVER
NEW ENGLAND AND RIDGES SW INTO THE MID MS VALLEY...KEEPING FAIR
WEATHER OVER CENTRAL/SE IL. CIRRUS CLOUDS OVER IA AND MORE
SCATTERED OVER MO/IL TO GRADUALLY INCREASE OVER CENTRAL IL THROUGH
TONIGHT AND LEAD TO BROKEN CIRRUS CLOUDS LATER THIS EVENING. RUC...
NAM AND HRRR HAS HIGHS IN THE MID TO UPPER 50S BY MID AFTERNOON
...BUT WENT A FEW DEGREES ABOVE THAT IN THE UPPER 50S AND LOWER
60S SINCE CURRENT TEMPS ARE RUNNING A FEW DEGREES AHEAD OF
GUIDANCE.
07
&&
.AVIATION...
ISSUED 532 AM CST SUN NOV 18 2012
QUIET/PREDOMINANTLY VFR AVIATION WEATHER CONDITIONS EXPECTED ACROSS
THE CENTRAL ILLINOIS TERMINALS THROUGH THE 12Z TAF VALID TIME.
THIS MORNING WILL BE ANOTHER MORNING WITH PATCHY MVFR FOG FOR A
COUPLE HOURS...ALTHOUGH THE AREAL COVERAGE OF THE FOG SHOULD BE
LESS THAN THE PAST COUPLE OF DAYS. AN APPROACHING UPPER LEVEL
DISTURBANCE WILL SPREAD CIRRUS CIGS ACROSS THE TERMINALS BY LATE
TONIGHT...BUT CIGS WILL BE WELL INTO THE VFR CATEGORY. THESE CIGS
AND SOUTHERLY WINDS STAYING A BIT STRONGER AT NIGHT SHOULD
PRECLUDE FOG REDEVELOPMENT LATER TONIGHT.
BAK
&&
.PREV DISCUSSION...
ISSUED 250 AM CST SUN NOV 18 2012
CURRENT WEATHER PATTERN NOT MUCH DIFFERENT THAN 24 HRS AGO...WITH
AN UPPER LOW OVER THE EXTREME SERN US...AND HIGH PRESSURE RIDGE
FROM SERN CANADA TO THE CENTRAL GULF COAST. SFC WINDS IN THE
OVERNIGHT LIGHTER...BUT PREDOMINANTLY OUT OF THE S/SE AS THE SUN
COMES UP. FORECAST IS ESSENTIALLY ONE OF TEMPERATURES. TWO WAVES
ARE PROGGED TO MOVE THROUGH THE QUASI ZONAL FLOW...MON/MON
NIGHT...AND AGAIN LATER IN THE WEEK...BUT THE MODELS ARE SKETCHY
WITH CONSISTENCY...AND THE ATMOSPHERE WILL BE STRUGGLING TO
PRODUCE MOISTURE. AS A RESULT...THE ZONE FORECAST IS RUNNING DRY
AT THE MOMENT. TEMPERATURES RUNNING ABOVE NORMAL THROUGH MIDWEEK.
SHORT TERM...TODAY AND TOMORROW...
RATHER QUIET WEATHER AND S/SERLY WINDS AT THE SFC WITH HIGH PRESSURE
RIDGE OVER THE EASTERN HALF OF THE COUNTRY. MILD TEMPS
CONTINUE...APPROACHING LOW 60S FOR MUCH OF THE AREA. MOSTLY SUNNY
SKIES...AND CLEAR OVERNIGHT WILL COUNTER THE SOUTHERLY FLOW WITH RATHER
EFFECTIVE RADIATIONAL COOLING AND TEMPS DROPPING INTO THE UPPER
30S AND NEAR 40. SOUTHERLY WINDS PICK UP A BIT ON MONDAY...AND A
BROAD AREA OF WAA PUSHES UNSEASONABLE HEAT INTO THE SW AND CENTRAL
PORTIONS OF THE COUNTRY. TEMPS MONDAY A BIT AHEAD OF GUIDANCE...AS
THE SLOW WARMING TREND CONTINUES ACROSS THE MIDWEST.
LONG TERM...TUESDAY THROUGH SATURDAY...
HIGH PRESSURE RIDGE SLOWLY DRIFTS EASTWARD AND THE CLOSED UPPER
LOW KICKS OUT OF THE SE. A SHORT WAVE RIPPLES THROUGH THE UPPER
ATMOSPHERE...BRINGING A CHANCE FOR SHOWERS MON/MON NIGHT. AND
THOUGH THE GFS AND THE NAM ARE BOTH PORTRAYING SOME QPF FOR THE
REGION...KEEPING THE POPS RELATIVELY LOW...IN THE SLIGHT CHANCE
CAT...AND LACK OF COVERAGE POTENTIAL IF NOTHING ELSE. MOISTURE IS
SOMEWHAT LACKING THROUGH THE LAYER AHEAD OF THE SYSTEM. SOUTHERLY
WINDS PRIOR TO MONDAY NOT PROVIDING MUCH MOISTURE TRANSPORT INTO
THE AREA. WINDS START TO PICK UP A BIT ON MON WITH AN APPROACHING
STORM SYSTEM...BUT STILL NOT MUCH IN EXCESS OF 10 KTS. MODELS
HAVING A BIT OF AN ISSUE WITH THE WAVE ITSELF...WITH THE ECMWF
HOLDING BACK A BIT AND PASSING A MORE VIGOROUS PIECE OF ENERGY
LATER ON TUESDAY...ALBEIT A BIT OF AN OUTLIER. WILL WATCH
CAREFULLY.
ON THE OTHER SIDE OF THE CHANCES FOR SHOWERS MON...THE
WARMING TREND CONTINUES THROUGH MID WEEK. 850MB TEMPS AT 6-7C WILL
HAVE THE POTENTIAL TO TRANSLATE INTO UPPER 50S/LOWER 60S. GUIDANCE
HAS NOT COMPLETELY LATCHED ONTO THE WARMING TREND...THOUGH THE
MODEL FIELDS CLEARLY SHOW THE THERMAL RIDGE IN THE WESTERN CONUS
DEEPENING AND SLOWLY CREEPING INTO THE MIDWEST. HAVE BUMPED MAX
TEMPS A FEW DEGREES AHEAD OF ALLBLEND FOR MON- WED...AND A BIT ON
THURSDAY. THURSDAY MAY BE COMPLICATED BY AN APPROACHING STORM
SYSTEM AND ASSOCIATED CLOUD COVER...BUT SYSTEM STILL HAS A BIT OF
UNCERTAINTY AND WOULD ALSO HAVE THE SAME PROBLEM AS MONDAYS WAVE WITH
SCANT MOISTURE. KEEPING THE POPS LOW AND THE TEMPS A COUPLE OF
DEGREES ABOVE GUIDANCE...BUT MODERATE FOR NOW.
HJS
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1003 AM CST SUN NOV 18 2012
.DISCUSSION...
321 AM CST
SYNOPSIS...SOME THINGS BECOME CLEARER WHILE OTHER PARTS OF THE
FORECAST BECOME MORE MUDDLED. OVERALL A GRADUAL WARMING PATTERN IS
STILL EXPECTED THROUGH MONDAY...WITH TEMPERATURES WELL ABOVE NORMAL
WEDNESDAY AND THANKSGIVING. NO SIGNIFICANT PRECIP IS EXPECTED.
TODAY THROUGH MONDAY...
HIGH PRESSURE CURRENTLY CENTERED OVER SOUTHEASTERN QUEBEC/UPPER NEW
ENGLAND STRETCHES THROUGH THE MISSISSIPPI RIVER VALLEY. THE HIGH
WILL REMAINED CENTERED THERE THROUGH EARLY NEXT WEEK WITH RELATIVELY
QUIET WEATHER EXPECTED LOCALLY. TEMPS WILL BE AROUND 60 TODAY WITH
CLEAR SKIES AND SOUTHERLY FLOW.
CLOUDS INCREASE TOMORROW AS A THROUGH OF LOW PRESSURE/WEAK COLD
FRONT APPROACH FROM THE WEST. AS SUCH WENT WITH TEMPS A DEGREE OR
TWO COOLER ON MONDAY...BUT STILL WELL ABOVE AVERAGE.
MONDAY NIGHT AND TUESDAY...
LOW PRESSURE CURRENTLY OVER WESTERN BRITISH COLUMBIA WILL PUSH
EASTWARD THROUGH CANADA...AND MODELS CONTINUE TO PUSH THE LOW
FURTHER NORTH. THE LOWS COLD FRONT/LOW PRESSURE TROUGH WILL PASS
THROUGH THE AREA. FORCING REMAINS WEAK ALONG THE COLD FRONT
THEREFORE EXPECTING A FEW HUNDREDTHS AT BEST MONDAY EVENING THROUGH
MONDAY NIGHT. GUIDANCE INDICATES THE TROUGH/COLD FRONT WEAKENS AS
IT APPROACHES THE CWA SO THE BEST CHANCE OF PRECIP LOOKS TO BE
OVER THE WESTERN AND NORTHERN PORTIONS OF THE CWA MONDAY NIGHT.
AND BY BEST CHANCE I MEAN BEST VERY VERY SLIGHT CHANCE.
PRECIP MOVES OUT BY TUESDAY MORNING AND HIGH PRESSURE QUICKLY MOVES
OVER THE CWA. THINKING TEMPS WILL ONCE AGAIN BE A DEGREE OR TWO
HIGHER THAN MONDAY DUE TO WEAK UPPER LEVEL WAA AND CLEARING SKIES.
WEDNESDAY AND THANKSGIVING...
SOUTHERLY FLOW RETURNS IN FORCE WEDNESDAY AS THE HIGH PRESSURE
SLIDES TOWARD THE SOUTHEAST US. 850 HPA TEMPS SOAR TO AROUND 10C
WEDNESDAY AND THANKSGIVING...THEREFORE WENT A FEW DEGREES ABOVE
ALL-BLEND GUIDANCE ONCE AGAIN. ITS LOOKING LIKE THURSDAY MAY BE THE
WARMER OF THE TWO DAYS WITH TEMPS BOTH DAYS AT OR ABOVE 60 DEGREES.
MOST PEOPLE WOULD AGREE THAT IS SOMETHING TO BE THANKFUL ABOUT.
EXTENDED...THANKSGIVING NIGHT THROUGH SATURDAY...
WHAT HAPPENS THANKSGIVING EVENING/NIGHT IS THE BIG FORECAST
QUESTION. THE GEM AND ECMWF INDICATE LOW PRESSURE WILL MOVE FROM
THE CENTRAL PLAINS THROUGH WISCONSIN WITH ITS COLD FRONT MOVING
THROUGH THE CWA THANKSGIVING NIGHT. THE GFS ON THE OTHER HAND HAS
THE LOW MOVING MUCH FARTHER NORTH OVER CENTRAL ONTARIO AND QUEBEC.
THE GFS SOLUTION IS ALSO MUCH FASTER THAN THE OTHER TWO SOLUTIONS.
SINCE THE GEM AND ECMWF ARE MERGING TOWARD EACH OTHER...LEANING
TOWARD THAT SOLUTION. THERE ARE ENOUGH DIFFERENCES IN THE SOLUTIONS
THAT DECIDED TO NOT MAKE ANY ADJUSTMENTS TO THE ALL-BLEND TEMPS OR
SLIGHT CHANCE POP FORECAST.
THAT BEING SAID...IF THE ECMWF SOLUTION IS TO BE BELIEVED...A
SIGNIFICANT TEMPERATURE DROP WILL BE EXPECTED BETWEEN THANKSGIVING
AND FRIDAY. BY FRIDAY AFTERNOON 850 HPA TEMPS ARE WELL BELOW ZERO.
THE GFS FEATURES A MUCH WEAKER COLD AIR PUSH SINCE ITS UPPER LEVEL
PATTERN IS VERY ZONAL. NONETHELESS IT DOES FEATURE 850 HPA TEMPS
BELOW ZERO MOVING OVERHEAD SATURDAY.
JEE
&&
.CLIMATE...
321 AM CST
A SHIFT IN THE UPPER PATTERN WILL ALLOW SOME MODERATION OF
TEMPERATURES GOING INTO THE WEEKEND AND PREVAILING FOR SEVERAL DAYS
THEREAFTER. WHILE THE MODERATION WILL HELP OBSERVED TEMPERATURES TO
EXCEED DAILY NORMALS THE FACT THAT INCREASINGLY SHORTER DAYS AND
LOWERING SUN ANGLES RESULT IN THE NORMAL HIGH TEMPERATURE FALLING BY
1 DEGREE F ABOUT EVERY 2 DAYS. SO...IT IS THE COMBINATION OF THE
LOWERING NORMAL MAXIMUM TEMPERATURES ALONG WITH THE WARMING THAT
WILL RESULT IN DAYTIME TEMPERATURES TO CLIMB TO ABOVE NORMAL...WHICH
ARE NOW ONLY IN THE UPPER 40S AT MID NOVEMBER.
NORMALS...
CHICAGO ROCKFORD
MAX MIN MAX MIN
NOV 01 56 38 56 36
NOV 17 47 32 47 30
NOV 30 40 27 39 24
THIS UNUSUAL PATTERN WILL ALSO ALLOW HIGH TEMPERATURES ON
WEDNESDAY AND THURSDAY...THANSKGIVING...TO COME CLOSE TO THE
RECORD HIGH TEMPERATURES. WHILE FORECASTED HIGH TEMPERATURES ARE
CURRENTLY A FEW DEGREES COOLER THAN THE RECORDS...HERE ARE THE THE
MAX TEMPERATURE RECORDS FOR FOOD FOR THOUGHT:
CHICAGO ROCKFORD
NOV 21 72 1913 73 1913
NOV 22 69 1913 69 2010
TRS/JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* LAKE BREEZE MOVING INLAND TO MDW AND ORD VC 21-22Z TIME-FRAME.
TRS
//DISCUSSION...UPDATED 14Z...
LATEST RUC AND HRR MODEL OUTPUT SUGGESTING A WEAK LAKE BREEZE...
SUCH AS OCCURRED FRI AND SAT...DEVELOPING AND MOVING INLAND TO
MDW AND ORD VC 21-22Z TIME-FRAME. WINDS EXPECTED TO BECOME A BIT
MORE SOUTHERLY LATE MORNING AND EARLY AFTERNOON AND THE BACKING
TO SE-ESE THERE TERMINALS FOR LATE AFTERNOON INTO EARLY EVE.
TRS
PREVIOUS...UPDATED 12Z...
HIGH PRESSURE PARKED OVER THE EASTERN UNITED STATES WILL MAINTAIN
HIGH CLOUDS AND RELATIVELY LIGHT SOUTH TO SOUTHEASTERLY WINDS OVER
THE LOCAL TERMINALS. ALTHOUGH LATEST ASOS OBS AT ISSUANCE TIME
WERE SHOWING CALM WINDS...OPTED TO KEEP A SSE DIRECTION AND 5 KTS
IN THE TAFS TO HELP CRAFT A PLAN TO START OF THE DAY. THIS ALSO
MATCHES THE WINDS REPORTED ELSEWHERE AROUND ORD AS RELAYED BY THE
CWSU. DID NOT ATTEMPT TO PIN DOWN GUSTS OR MINOR VARIATIONS IN
DIRECTION THAT COULD OCCUR THROUGHOUT THE DAY...THOUGH THERE IS A
CHANCE THAT WINDS COULD TURN FARTHER TO THE EAST IN RESPONSE TO A
LAKE BREEZE INFLUENCE.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM CONFIDENCE ON WIND VEERING FM SSE TO SE AND ESE DURING
MID AFTERNOON WITH WEAK LAKE BREEZE MOVING INLAND.
* HIGH CONFIDENCE REMAINDER OF FCST.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED12Z...
MONDAY NIGHT...VFR WITH SLIGHT CHANCE OF LIGHT RAIN.
TUESDAY AND WEDNESDAY...VFR.
THANKSGIVING...VFR WITH A CHANCE OF SHOWERS LATE.
FRIDAY AND SATURDAY...VFR.
LENNING
&&
.MARINE...
249 AM CST
A BROAD RIDGE ACROSS THE NORTHEASTERN UNITED STATES WILL WEAKEN
SOMEWHAT BUT MOVE VERY LITTLE THROUGH THE FIRST HALF OF THE WEEK.
THE LOCATION OF THIS FEATURE WILL SUPPORT CONTINUED SOUTHERLY FLOW
ACROSS THE LAKE. THE LACK OF A STRONG PRESSURE GRADIENT WILL
GENERALLY KEEP WINDS AND WAVES BELOW LEVELS THAT WOULD POSE
HAZARDS. THE EXCEPTION WOULD BE ALONG THE FAR NORTHERN SHORE AT
THE END OF THE LONG FETCH WHERE SMALL CRAFT HEADLINES ARE IN
EFFECT. EVEN THE APPROACH OF A TROUGH FROM THE WEST TOWARD MIDWEEK
WILL NOT BE ENOUGH TO BOOST WINDS...SINCE BY THAT TIME THE RIDGE
TO THE EAST WILL HAVE WEAKENED SOMEWHAT AND MOVED A BIT FARTHER
AWAY TOWARD THE ATLANTIC COAST.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1008 AM MST SUN NOV 18 2012
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 145 AM MST SUN NOV 18 2012
SUMMARY...DRY WEATHER WITH ABOVE NORMAL TEMPERATURES WILL CONTINUE
THROUGH THE SHORT TERM PART OF FORECAST.
TODAY...DEW POINT DEPRESSIONS CONTINUE TO LOWER EARLY THIS MORNING.
LATEST FOG PRODUCT SATELLITE IMAGERY DOES NOT SHOW ANY EVIDENCE OF
FOG FORMATION YET...BUT WITH LIGHT SURFACE WINDS...EXPECT SOME
PATCHY FOG TO DEVELOP SHORTLY BEFORE SUNRISE MAINLY ALONG HIGHWAY
83. LATEST HRRR MODEL SUPPORTS THIS. OTHERWISE...A WEAK SHORTWAVE
TROUGH WILL MOVE ACROSS THE FORECAST AREA DURING THE DAY...BUT
RAOBS/MODELS CONTINUE TO SHOW THAT THE AIR MASS WILL BE DRY. ONLY
MID AND HIGH LEVEL CLOUDS WILL ADVECT ACROSS THE AREA THIS AFTERNOON.
LEE SIDE SURFACE TROUGH WILL MOVE EAST THIS AFTERNOON AND WILL
SWITCH WINDS TO THE WEST ALONG THE COLORADO/KANSAS BORDER. WITH
LACK OF AIR MASS CHANGE...EXPECT TEMPERATURES TO BE SIMILAR TO
THOSE THAT OCCURRED SATURDAY.
TONIGHT...500 MB FLOW BECOMES INCREASINGLY ZONAL BEGINNING TONIGHT.
MODELS SHOW WEAK COLD AIR ADVECTION AT THE SURFACE STARTING AROUND
12Z.
MONDAY...DRY ZONAL MID LEVEL FLOW WILL CONTINUE. SURFACE WINDS WILL
BE NORTH BEHIND A PUSH OF SLIGHTLY COOLER AIR. ALTHOUGH 850 MB
TEMPERATURES COOL...THE COOLING IS VERY SLIGHT...ONLY ABOUT 1 DEGREE
CELSIUS. ONCE AGAIN...PERSISTENCE TEMPERATURE FORECASTS LOOK DECENT.
MONDAY NIGHT THROUGH TUESDAY NIGHT...500 MB RIDGE AND ASSOCIATED
SUBSIDENCE WILL DEVELOP OVER THE HIGH PLAINS. LEE SIDE TROUGH WILL
REFORM BY TUESDAY AFTERNOON BRINGING A RETURN OF SOUTH WINDS AND WEAK
WARM AIR ADVECTION.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 145 AM MST SUN NOV 18 2012
VERY LITTLE HAS CHANGED IN THE EXTENDED PERIODS WITH MODELS STILL
ADVERTISING PROGRESSIVE ZONAL PATTERN WITH MAIN STORM TRACK ALONG
US/CANADA BORDER. THERE ARE A FEW WEAK SHORTWAVE TROUGHS THAT COME
CLOSE TO THE CWA...HOWEVER WITH A DEEP DRY LAYER IN PLACE THE MOST
WE WOULD EXPECT TO SEE IS AN INCREASE IN MID-HIGH CLOUDS. RH VALUES
STILL LOOK TO BE NEAR RFW CRITERIA WEDNESDAY AFTERNOON...HOWEVER
SURFACE GRADIENT IS WEAK OVER THE CWA AND WINDS SHOULD BE WELL BELOW
CRITERIA.
OVERALL...STILL EXPECTING ABOVE NORMAL TEMPERATURES AND DRY CONDITIONS
TO CONTINUE. WED HIGHS WILL APPROACH 70F...WITH HIGHS IN THE UPPER
50S/NEAR 60F THROUGH THE REMAINING PERIODS AFTER A WEAK COLD FRONT
MOVES THROUGH THE REGION WED NIGHT/THU. OVERNIGHT LOWS SHOULD BE IN
THE LOW TO MID 30S EACH NIGHT...WHICH IS IS STILL ABOUT 10F ABOVE NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1006 AM MST SUN NOV 18 2012
VFR CONDITIONS ANTICIPATED AT BOTH KGLD AND KMCK THROUGH THE TAF
PERIOD. HIGH CLOUDS WILL GRADUALLY MOVE EAST THROUGH THE REST OF
TODAY. LIGHT WESTERLY SURFACE WINDS TONIGHT WILL PREVENT FOG
FORMATION...THOUGH WILL NEED TO MONITOR KMCK FOR PATCHY FOG IN THE
REPUBLICAN RIVER VALLEY AROUND SUNRISE MONDAY MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...MENTZER
SHORT TERM...MENTZER
LONG TERM...DR
AVIATION...024
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
332 PM CST Sun Nov 18 2012
.DISCUSSION...
Tonight - Monday:
The main challenges through this period are the timing/onset of
precipitation and the duration into the Monday period. Water vapor
imagery was showing the weak upper level disturbance moving out of
the Southern Rockies and into the Plains. Radar and visible/IR
imagery show what also may be a weak baroclinic zone across south
central to eastern Nebraska with a few light returns showing up on
radar. The GFS does indicate a slightly tighter theta-e gradient
aloft through this area. The radar returns are consistent with the
latest HRRR run, albeit a few hours delayed, which develops
precipitation in this area this afternoon. Precipitation should
increase in coverage across the eastern half of Kansas this evening
as the support from the upper wave moves into the region. Think that
the timing of precipitation in our western zones will be in the 2-3Z
window and persist for 4-6 hours as the whole area moves into our
eastern zones. It still looks like coverage will be in the 50% range
and precipitation totals will be less than a quarter inch for those
that do pick up rain. Precipitation still looks to be coming to end
by mid day Monday. There could potentially be a few sprinkles Monday
afternoon as another weak wave will be tracking into the area. But
models are in good agreement moving any QPF away from the area
during the afternoon so the chances of precipitation look too small
to mention at this time.
High temperatures on Monday will be restrained a bit in our eastern
zones as cloud cover will be exiting the area preventing a warm up
like our western zones are expected to see. Overall, highs will
range from the low to mid 60s in our west to the middle 50s in our
east.
Tuesday - Tuesday Night:
Quiet weather with above normal temperatures are expected this
period. High temperatures should climb into the 60s across the area
but may be inhibited by weak flow and limited mixing. Overnight lows
should be mild for this time of year with lows generally in the low
to mid 40s. With light winds overnight, some of our typical low
lying/ drainage areas may fall into the 30s.
CDB
Wednesday - Sunday:
Model consensus is a continuation of near to above average
temperatures during this period with little in the way of
precipitation. Travel day on Wednesday looks outstanding with
temperatures nearing the 70 degree mark possible in the far western
CWA.
Most of the focus is on Thursday/Thanksgiving. An upper level ridge
will exit the region on Wednesday as another impulse within the
southern stream lifts northeast from the Southern Rockies on
Thanksgiving. Despite a lack of low level moisture there is
increasing support from the GFS and ECMWF that sufficient mid level
Pacific moisture will be available for scattered light showers as a
weak cold front drops southeast through MO Thursday night. Have
nudged Thursday night pops up to chance category for the far
southern counties.
A large vortex over the Gulf of Alaska is expected to eject a
significant piece of energy eastward at the start of the period. The
resulting shortwave trough will dig/deepen southeast through the
Upper MS Valley and Great Lakes Thursday night/Friday. Any weather
with this feature will track to the north but a secondary cold front
will pass through on Friday and reinforce an intrusion of colder
air. Have gone along with model consensus on temperatures but the
trend is towards more cooling and can envision later forecasts
tweaking Friday`s temperatures downward some more.
Zonal flow through the mid levels and warm air advection in the
boundary layer will return for the dry weekend.
MJ
&&
.AVIATION...
For the 18Z TAFs, VFR conditions are likely to occur throughout the
valid period. The one exception will be for a few hours tonight as an
upper level disturbance tracks across the region. As it does, widely
scattered to scattered rain showers are possible at the terminals.
This system will not have a lot of moisture to work with and the
system itself is rather weak. So the result is a higher probability
for VFR conditions as the wave is tracking through than sub-VFR
conditions. During any showers, ceilings may fall to around 4 to 5
thousand feet and the shower intensity should not be strong enough to
restrict visibilities.
Outside of the rain chances tonight, winds will be rather strong and
gusty from the south this afternoon before diminishing some tonight.
Winds will also increase again from the south to southwest by late
tomorrow morning or by noon but do not look to be as strong as this
afternoon.
CDB
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
305 PM CST SUN NOV 18 2012
.SHORT TERM...THROUGH MONDAY AFTERNOON. OVERALL THE BENIGN WEATHER
PATTERN OF LATE CONTINUES THROUGH THE NEXT 24 HOURS...WITH THE
MAIN FAIRLY MINOR ISSUE CONSISTING OF THE POSSIBILITY OF SPRINKLES
ACROSS SOUTHEAST ZONES LATE THIS AFTERNOON INTO THIS EVENING.
20Z OBJECTIVE SURFACE ANALYSIS PLACES A GENERALLY NORTH-SOUTH
TROUGH AXIS RUNNING FROM WESTERN SD THROUGH THE NEB PANHANDLE AND
DOWN ALONG THE KS/CO BORDER...TRAILING SOUTH FROM A 1005MB LOW AT
THE WY/MT/SD INTERSECTION. MEANWHILE...AN EXPANSIVE RIDGE AXIS
CONTINUES TO DOMINATE MUCH OF THE EASTERN CONUS. THE CWA LIES
ALONG THE INTERFACE BETWEEN THESE TWO FEATURES...WITH A MODEST
PRESSURE GRADIENT AND DIURNAL MIXING GENERALLY INTO THE 900-875MB
RANGE DRIVING SOUTHERLY SUSTAINED BREEZES TYPICALLY 13-23 MPH WITH
GUSTS MAINLY 20-25 MPH. VISIBLE SATELLITE CONFIRMS A RATHER
HEALTHY COVERAGE OF MID-HIGH CLOUDS STREAMING
OVERHEAD...ESPECIALLY ACROSS THE SOUTHEAST 2/3 OF THE CWA. RADAR
EVEN SUGGESTS A FEW SPRINKLES MAY HAVE ALREADY FALLEN THIS
AFTERNOON ACROSS PARTS OF NUCKOLLS/THAYER/FILLMORE COUNTIES. THESE
CLOUDS SEEM TO BE HAVING A VARYING EFFECT ON TEMPS THIS
AFTERNOON...WITH BOTH KS ZONES AND NORTHERN ZONES IN NEB VERY MUCH
ON TRACK TO NEAR FORECAST HIGHS IN THE LOW-MID 60S...WHILE CENTRAL
AREAS INCLUDING THE TRI-CITIES MAY FALL A BIT SHORT AND STRUGGLE
TO REACH 60. THE CLOUDS HAVE LIKELY ALSO REDUCED MIXING SOMEWHAT
AND HELD DOWN WIND SPEEDS SLIGHTLY. WATER VAPOR IMAGERY AND SHORT
TERM MODEL DATA DEPICTS BROAD QUASI-ZONAL/SLIGHTLY SOUTHWESTERLY
FLOW ACROSS THE CENTRAL/WESTERN CONUS...WITH A PAIR OF FAIRLY
VIGOROUS SHORTWAVE TROUGHS TRANSLATING THROUGH THE NORTHERN
ROCKIES AND OFF THE PACIFIC NORTHWEST COAST. CLOSER TO HOME...A
MORE SUBTLE LOW AMPLITUDE MID LEVEL WAVE IS CURRENTLY LIFTING OUT
OF CO/WY...INTO NEB/KS...WITH THE MID-HIGH CLOUDS STREAMING OUT
AHEAD OF THIS WAVE LARGELY ASSOCIATED WITH A MODEST 70+KT 300MB
JET STREAK.
LATE THIS AFTERNOON INTO THIS EVENING...THIS LOW AMPLITUDE MID
LEVEL WAVE WILL CONTINUE TRACKING ACROSS THE HEART OF THE CENTRAL
PLAINS...WITH THE ONGOING BATCH OF MID-HIGH CLOUDS GRADUALLY
CLEARING THE CWA FROM WEST-EAST AND PAVING THE WAY FOR A CLEAR
OVERNIGHT. PRIOR TO THIS HOWEVER...THE MOISTURE-STARVED
DISTURBANCE WILL CONTINUE TO PROMOTE MODEST THETA-E ADVECTION
EVIDENT IN THE 850-700MB LAYER MAINLY OVER THE EASTERN HALVES OF
NEB/KS. DESPITE PLENTIFUL DRY AIR ESPECIALLY BELOW 700MB...WILL
MAINTAIN A CHANCE OF SPRINKLES THROUGH 10 PM FOR LOCATIONS
GENERALLY EAST OF A LINE FROM YORK-NELSON-OSBORNE...WITH
ESSENTIALLY ZERO RISK OF PRECIP ACROSS THE REMAINDER OF THE CWA.
DESPITE VARIOUS MODELS SUCH AS THE NAM/ECMWF/GFS KEEPING ALL QPF
EAST OF THE CWA INTO THIS EVENING...THE WEAK RADAR RETURNS ALREADY
OBSERVED WITHIN THE FAR SOUTHEAST CWA THIS AFTERNOON ALONG WITH
THE 1KM REFLECTIVITY PROGS FROM THE LATEST HRRR MAKE ME UNWILLING
TO COMPLETELY IGNORE SPRINKLE POTENTIAL...ALTHOUGH AGREE WITH
PREVIOUS FORECASTER THAT ANYTHING MEASURABLE SHOULD FOCUS WELL
EAST/SOUTHEAST OF THE LOCAL AREA. AS MENTIONED...THE OVERNIGHT
WILL FEATURE CLEAR SKIES...WHILE AT THE SURFACE...A WEAK TROUGH
WILL MOVE EASTWARD ACROSS MAINLY THE WESTERN 1/2 OF THE
CWA...TURNING LIGHT BREEZES NORTHWESTERLY IN ITS WAKE. TEMPS
OVERNIGHT COULD BE A BIT TRICKY...AS THE NORTHWEST COMPONENT
BEHIND THE SURFACE TROUGH COULD ACT TO HOLD THINGS UP...WHILE JUST
AHEAD OF THE TROUGH THE COMBINATION OF NEAR-CALM TO LIGHT
SOUTHERLY BREEZES AND CLEAR SKIES SHOULD PROMOTE AN EFFICIENT
DROP. FEEL THAT A BLEND OF 12Z MET/MAV GUIDANCE IS PROBABLY THE
BEST COMPROMISE...AND THUS WILL LOWER MOST OF THE CWA 2-3 DEGREES
FROM PREVIOUS FORECAST...BUT STILL KEEPING ALL BUT A FEW NORTHWEST
COUNTIES ABOVE FREEZING AND IN THE 33-37 RANGE. ALTHOUGH SUPPOSE
SOME HAZE OR LIGHT FOG IS NOT OUT OF THE QUESTION AROUND SUNRISE
ESPECIALLY ALONG THE TROUGH AXIS...AM NOT EXPECTING FOG TO BE
WORTHY OF A FORMAL MENTION IN THE FORECAST.
FOR THE MONDAY DAYTIME PERIOD...TRANQUIL...MOISTURE-STARVED QUASI-
ZONAL FLOW WILL CONTINUE ALOFT OVER THE CENTRAL PLAINS...AS THE
SHORTWAVE CURRENTLY AFFECTING THE AREA MOVES WELL OFF EAST TOWARD
THE GREAT LAKES...WHILE THE SOUTHERN FRINGES OF ANOTHER MID LEVEL
WAVE CENTERED OVER THE CANADIAN BORDER BRUSHES INTO WESTERN NEB
DURING THE AFTERNOON. WHILE THE MAJORITY OF THE DAY SHOULD REMAIN
QUITE SUNNY WITH ONLY A FEW PASSING SPLOTCHES OF HIGH CIRRUS...THE
MID-LATE AFTERNOON HOURS COULD FEATURE A BIT GREATER INCOMING
CIRRUS COVERAGE MAINLY OVER NORTHWEST ZONES ASSOCIATED WITH THE
APPROACHING SHORTWAVE TROUGH. AT THE SURFACE...THE TROUGH AXIS
ESSENTIALLY BISECTING THE AREA AT SUNRISE WILL CONTINUE PUSHING
SOUTHEAST THROUGH THE DAY. IN ITS WAKE...FAIRLY LIGHT BREEZES OF
ONLY AROUND 10 MPH FROM THE NORTH-NORTHWEST WILL PREVAIL. THESE
LIGHT WINDS WILL MAKE FOR PLEASANT CONDITIONS THANKS TO THE NEXT
IN A LONG STRETCH OF SEASONABLY WARM DAYS. MADE VERY LITTLE
CHANGE TO HIGH TEMPS...AND IF ANYTHING NUDGED SOME PLACES UP
ANOTHER DEGREE...AIMING FOR LOW 60S NORTHEAST...MID 60S CENTRAL
INCLUDING TRI-CITIES...AND UPPER 60S KS ZONES. THE OVERALL BIGGEST
CHANGE TO THE MONDAY GRIDS WAS TO DEWPOINTS...WHICH WERE LOWERED
4-7 DEGREES...WITH VALUES ONLY EXPECTED TO AVERAGE IN THE LOW-MID
30S IN MOST AREAS. EVEN SO...RELATIVE HUMIDITY VALUES SHOULD STILL
DROP NO LOWER THAN THE UPPER 20S...KEEPING FIRE DANGER QUITE LOW
THANKS TO THE LIGHT WINDS.
.LONG TERM...STARTING 00Z TUESDAY. GUIDANCE FROM THE
OPERATIONAL GFS...GEFS-MEAN AND EC ALL CONTINUE TO SUGGEST MID
AND UPPER LEVEL JET ENERGY WILL REMAIN TO THE NORTH OF THE CENTRAL
PLAINS THROUGH THE LONG TERM FORECAST PERIOD. A MID LEVEL SHORT
WAVE IS EXPECTED TO PUSH ACROSS SOUTHERN CANADA AND THE NORTHERN
PLAINS DURING THE DAY THURSDAY...ALONG WITH A WEAK MID LEVEL
PERTURBATION WHICH IS EXPECTED PUSH ACROSS THE SOUTHERN PLAINS
ALSO ON THURSDAY. ALTHOUGH THESE MID LEVEL DISTURBANCES WILL
REMAIN NORTH AND SOUTH OF OUR REGION...AN ASSOCIATED LOW LEVEL
BAROCLINIC ZONE IS EXPECTED TO PUSH ACROSS OUR AREA DURING THE DAY
THURSDAY. THE OPERATIONAL GFS AND EC BOTH CONTINUE TO SUGGEST LOW
LEVEL CONVERGENCE AND RESULTANT FORCING WILL REMAIN WEAK ALONG
THIS BAROCLINIC ZONE. ALTHOUGH THERE COULD BE AN INCREASE IN MID
TO HIGH LEVEL CLOUDS AS THE MID LEVEL PERTURBATION PUSHES ACROSS
THE SOUTHERN PLAINS...AN OVERALL LACK IN KINEMATIC FORCING SHOULD
KEEP OUR AREA DRY THROUGHOUT THE LONG TERM FORECAST PERIOD.
LITTLE CHANGE IN THE LOW LEVEL AIRMASS TUESDAY THROUGH THURSDAY WILL
PRESENT SIMILAR TEMPERATURES EACH DAY...WITH HIGHS GENERALLY IN THE
60S AND LOWS IN THE 30S AND 40S...WHICH IS WELL ABOVE NORMAL FOR
THIS TIME OF YEAR. WEAK LOW LEVEL COLD AIR ADVECTION POST FROPA
BEGINNING THURSDAY NIGHT WILL THEN PRESENT SOMEWHAT COOLER WEATHER
TO FINISH OUT THE WEEK...WITH HIGHS GENERALLY IN THE 50S AND LOWS IN
THE 30S...STILL ABOVE NORMAL FOR THIS TIME OF YEAR.
&&
.PREV DISCUSSION... /ISSUED 1116 AM CST SUN NOV 18 2012/
AVIATION...18Z KGRI TAF. VFR CONDITIONS ARE EXPECTED. SURFACE LOW
PRESSURE ALONG THE FRONT RANGE OF THE ROCKIES THIS AFTERNOON WILL
GRADUALLY SHIFT EASTWARD THROUGHOUT THE TAF PERIOD. AHEAD OF THIS
SYSTEM...STRONG SOUTH WINDS WILL CONTINUE WITH WIND SPEEDS NEAR
15 TO 20 MILES PER HOUR. HIGH CIRRUS CAN ALSO BE EXPECTED
THROUGHOUT MUCH OF THE DAY...WITH DECREASING CLOUDS AND WIND
SPEEDS TOWARDS THE OVERNIGHT HOURS. THE MAIN TROUGH AXIS WILL
BEGIN TO SHIFT ACROSS THE REGION AROUND 6Z TO 8Z...WITH WINDS
EXPECTED TO SHIFT TO THE WEST NORTHWEST BEHIND THE TROUGH.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...BRYANT
AVIATION...SALTZMAN
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1121 AM CST SUN NOV 18 2012
.SHORT TERM...THROUGH TUESDAY NIGHT
212 AM CST SUN NOV 18 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION CHANCES TONIGHT INTO
MONDAY AS WELL AS TEMPERATURES THROUGHOUT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A DEEP TROUGH FROM JUST OFF THE COAST OF BRITISH COLUMBIA
INTO THE PACIFIC NORTHWEST...AND SOUTHWEST FLOW FROM THE DESERT
SOUTHWEST THROUGH THE UPPER MISSISSIPPI RIVER VALLEY REGION. WITHIN
THIS SOUTHWEST FLOW...SHORTWAVES OF NOTE ARE ALONG THE UTAH/COLORADO
BORDER AND IN NORTHWEST MINNESOTA. DPVA AHEAD OF THIS LATTER
SHORTWAVE COMBINED WITH 295-300K ISENTROPIC LIFT PRODUCED SHOWERS
ACROSS NORTHEAST MINNESOTA. THE 295K ISENTROPIC LIFT ALSO EXTENDED
SOUTHWEST FROM NORTHEAST MINNESOTA INTO CENTRAL IOWA...AND ALONG
THIS ZONE IS A BAND OF STRATUS WITH CEILINGS BETWEEN 6000-9000 FT.
THE BAND OF STRATUS ALSO SEPARATES MOIST AIR FROM VERY DRY AIR AT
850MB. FOR EXAMPLE...FROM 00Z SOUNDINGS...THE 850MB DEWPOINT AT DVN
WAS -20C WHILE IT WAS -2C AT MPX AND 1C AT OAX. THE BROAD SOUTHWEST
FLOW ALOFT HAS RESULTED IN A WARM ADVECTION PATTERN ACROSS THE UPPER
MIDWEST. 850MB TEMPS WERE +6C AT MPX AND OAX AT 00Z. THE LOW LEVEL
SOUTHERLY FLOW WAS FAIRLY STRONG WITH 925MB PROFILER AND VWP DATA
SHOWING SPEEDS OF 35-45KT AROUND THE FORECAST AREA. THESE WINDS ARE
HOLDING TEMPERATURES UP FROM THE MID 30S TO MID 40S...WARMEST IN
SOUTHEAST MINNESOTA.
TODAY AND TONIGHT...FOCUS IS ON THAT SHORTWAVE ALONG THE
UTAH/COLORADO BORDER. GOOD MODEL AGREEMENT REMAINS ON THIS SHORTWAVE
LIFTING UP THROUGH THE SOUTHWEST FLOW AND MOVING INTO WESTERN
PORTIONS OF THE FORECAST AREA BY 12Z MONDAY. BRIEF RIDGING DEVELOPS
OVER THE FORECAST AREA TODAY DOWNSTREAM OF THIS SHORTWAVE...WHICH
SHOULD ACT TO CLEAR THE CLOUDS UP SOMEWHAT. WITH THE RELATIVELY
SPEAKING WARM START...SUNSHINE AND 925MB TEMPS AROUND 6C WHICH ARE
SIMILAR TO YESTERDAY...ANTICIPATING HIGHS TO BE FAIRLY SIMILAR TO A
FEW DEGREES WARMER THAN YESTERDAY. FOR TONIGHT...THE 850MB MOISTURE
STREAM CURRENTLY OVER WESTERN MINNESOTA AND IOWA WILL GET PUSHED
EAST INTO THE FORECAST AREA BY THE SHORTWAVE. THE MAIN QUESTION IS
IF DPVA AND ISENTROPIC LIFT AHEAD OF THIS SHORTWAVE WILL BE STRONG
ENOUGH TO ACT ON THIS MOISTURE AND PRODUCE PRECIPITATION. MID CLOUD
DEVELOPMENT IS A CERTAINTY...GIVEN WHAT HAPPENED LAST EVENING ON
THE LEADING EDGE OF THE 850MB MOISTURE STREAM. THE 18.00Z
NAM/REGIONAL CANADIAN PAINT A DRY PICTURE AND EVEN THE GFS WHICH
LOOKS TO HAVE A BIT TOO MUCH MOISTURE COMPARED TO ALL OTHER MODELS
PRODUCES LITTLE IF ANY PRECIPITATION BEFORE 12Z. THE 17.12Z ECMWF
MEANWHILE REMAINS MOST ROBUST WITH 0.1-0.2 OF AN INCH OVER NORTHEAST
IOWA BETWEEN 06-12Z MONDAY. NEW 18.00Z ECMWF IS SLIGHTLY DRIER. SREF
TRENDS HAVE SHOWN LESS MEMBERS PRODUCING 0.01 OF AN INCH OVER THE
LAST 5 RUNS...DOWN FROM 40-50 PERCENT TO 10-30 PERCENT. AT THIS
POINT...CANNOT SEE GOING WITH THE MORE ROBUST ECMWF SOLUTION AND
HAVE KEPT CHANCES LOW IN THE 20-30 PERCENT RANGE...CENTERED IN THE
09-12Z PERIOD. WITH THE INCREASING CLOUDS AND A SOUTHERLY BREEZE
BEING MAINTAINED...A SLIGHTLY WARMER NIGHT THAN TONIGHT IS
ANTICIPATED.
MONDAY AND MONDAY NIGHT...THE SHORTWAVE OVER WESTERN PORTIONS OF THE
FORECAST AREA AT 12Z LOOKS TO MOVE THROUGH THE REST OF THE FORECAST
AREA BY EARLY AFTERNOON...WHILE THE TAIL END OF THE DEEP TROUGHING
IN THE PACIFIC NORTHWEST IS PROGGED TO DROP DOWN INTO THE FORECAST
AREA AFTER MIDNIGHT MONDAY NIGHT. THIS LATTER SHORTWAVE WILL COME
THROUGH DRY SINCE THE SHORTWAVE COMING THROUGH MONDAY MORNING ENDS
UP SCOURING OUT A LOT OF THE MOISTURE. THUS ALL FOCUS IS ON THE
MONDAY MORNING PERIOD. AGAIN HERE...MODELS ARE AT ODDS WITH FORCING
AND MOISTURE AVAILABILITY. THE 18.00Z NAM/REGIONAL CANADIAN SAYS
THERE IS TOO MUCH DRY AIR BELOW 800MB AND THE FORCING IS TOO WEAK
ABOVE IT TO ALLOW FOR PRECIPITATION TO MAKE IT TO THE SURFACE. ON
THE OTHER HAND...THE 18.00Z GFS AND 17.12Z/18.00Z ECMWF ARE MORE
ROBUST IN BOTH ARENAS AND END UP PRODUCING LIGHT QPF ACROSS MUCH OF
THE AREA. SREF TRENDS FOR THE FULL DAY MONDAY ARE ALSO SIMILAR TO
06-12Z MONDAY...SHOWING A DECLINE OF MEMBERS PRODUCING AT LEAST 0.01
OF AN INCH. IT USED TO BE UP AT 70-80 PERCENT BUT NOW IS DOWN TO
30-60 PERCENT. THUS...CONFIDENCE REMAINS TOO LOW TO ADJUST THE
PREVIOUS FORECAST PRECIPITATION CHANCES OF 20-40 PERCENT. CERTAINLY
IF ANY PRECIPITATION OCCURS...ANY RAIN LOOKS REALLY LIGHT. REGARDING
CLOUD COVER...IT NOW APPEARS THAT THE SHORTWAVE ON MONDAY MORNING
SHOULD HELP TO CLEAR THE CLOUDS OUT AS IT MOVES AWAY DURING THE
AFTERNOON. THERE MAY BE AN INCREASE OF CIRRUS WITH THE SHORTWAVE
COMING IN MONDAY NIGHT...BUT THATS ABOUT IT. NOTE THAT THERE IS
CONCERN FOR A LOW CLOUD DECK BASED ON THE GFS/ECMWF 925MB RH
PROGS...BUT THEY MAY BE TOO MOIST. FOR NOW TAKING A COMPROMISE
APPROACH BY SPEEDING UP THE CLEARING SOME FROM THE PREVIOUS
FORECAST. HAVING MORE CLOUDS MONDAY WILL HOLD THE TEMPERATURES DOWN
A FEW DEGREES FROM HIGHS OVER THE WEEKEND. A COOLER NIGHT SEEMS
LIKELY TOO FOR MONDAY NIGHT...ESPECIALLY IF THE CLEARING OCCURS.
TUESDAY AND TUESDAY NIGHT...IN THE WAKE OF THAT SHORTWAVE DROPPING
INTO THE FORECAST AREA TUESDAY MORNING...SOME FAIRLY STRONG RIDGING
IS PROGGED TO BUILD INTO THE FORECAST AREA BY TUESDAY EVENING. ABOUT
ALL THAT SHORTWAVE IS GOING TO DO IS PREVENT THE 850MB TEMP
CLIMB...NOTED BY 850MB TEMPS AT 18Z TUESDAY OF 5-7C. ONCE THE
RIDGING STARTS BUILDING IN...THESE TEMPS CLIMB...TOPPING OUT AT 8C
EAST TO 11C WEST BY 12Z WEDNESDAY. WITH WHAT SHOULD BE PLENTY OF
SUN...HIGHS SHOULD BE ABLE TO TOP OUT IN THE 50S AGAIN ON TUESDAY
GIVEN THE AFOREMENTIONED 850MB TEMPS. INCREASING SOUTHERLY FLOW
TUESDAY NIGHT IN THE WAKE OF HIGH PRESSURE THAT CROSSES THE AREA ON
TUESDAY WILL HELP TO KEEP TEMPERATURES UP IN SOUTHEAST MINNESOTA.
FOLLOWED A BLEND OF GUIDANCE FOR LOWS.
.LONG TERM...WEDNESDAY THROUGH SATURDAY NIGHT
212 AM CST SUN NOV 18 2012
MAIN FOCUS CONTINUES TO BE ON A POTENT SHORTWAVE TROUGH ENTERING THE
PACIFIC NORTHWEST WEDNESDAY MORNING. MODEL AGREEMENT HANDLING THIS
POTENT TROUGH BEGINS TO DECLINE AS EARLY AS 12Z THURSDAY...WITH THE
18.00Z ECMWF/CANADIAN SHOWING A DIGGING NATURE TO IT INTO THE
NORTHERN PLAINS. MEANWHILE...THE 18.00Z GFS TAKES A MORE PROGRESSIVE
APPROACH AND SENDS IT UP INTO NORTHERN ONTARIO ON THURSDAY. BOTH THE
GFS AND ECMWF HAVE COMPLETELY FLIPPED FROM PREVIOUS RUNS WITH THE
HANDLING OF THIS POTENT TROUGH. THE 18.00Z ECMWF LOOKS MORE LIKE THE
17.00Z GFS WHILE THE 18.00Z GFS LOOKS MORE LIKE THE 16.12Z ECMWF.
THIS HAS SIGNIFICANT IMPLICATIONS ON THE TEMPERATURE AND WIND
FORECASTS...PRIMARILY FRIDAY AND BEYOND. WITH THE MORE DIGGING
NATURE OF THE ECMWF/CANADIAN...THEY END UP CARVING OUT A DEEP TROUGH
ACROSS THE WESTERN GREAT LAKES REGION FOR FRIDAY...THOUGH WITHIN
THIS GROUP THE CANADIAN IS MORE PROGRESSIVE. WHICHEVER MODEL
SCENARIO PLAYS OUT...IT APPEARS DRY WEATHER WOULD BE THE RULE WITH
THE BEST JUXTAPOSITION OF FORCING AND MOISTURE EITHER NORTH OR
SOUTHEAST OF THE AREA. GIVEN THE DIFFERENCES EARLY IN THE LONG TERM
PERIOD...HARD TO SAY HOW THE WEEKEND WILL PLAY ITSELF OUT. NOTE THAT
THE 18.00Z GFS ENSEMBLES HAVE A PRETTY GOOD SPREAD TOO WITH REGARDS
TO THE POTENT TROUGH. THUS FOR NOW HAVE STAYED WITH A CONSENSUS
APPROACH WHEN IT COMES TO THE WEEKEND...YIELDING COOLER AND A
CONTINUATION OF DRY CONDITIONS.
REGARDING TEMPERATURES...WEDNESDAY AND THANKSGIVING DAY STILL LOOK
WELL ABOVE NORMAL...ESPECIALLY WEDNESDAY AS 925MB TEMPS CLIMB TO
10-12C FOR 18Z. MIXING TO 925MB YIELDS HIGHS FROM THE UPPER 50S TO
MIDDLE 60S...THUS HAVE BOOSTED HIGHS A FEW DEGREES. RECORD HIGHS FOR
WEDNESDAY ARE 72 AT LA CROSSE AND 69 AT ROCHESTER...STILL 5-10
DEGREES ABOVE THE GOING FORECAST. NOTE THAT 850MB TEMP
STANDARDIZED ANOMALIES HAVE NOW JUMPED TO NEAR 2...SUPPORTING THE
INCREASING IN HIGH TEMPERATURES. SOME COOLING IN 925MB TEMPS
TAKES PLACE ON THANKSGIVING DAY AS A COLD FRONT MOVES INTO THE
REGION. STILL...MOST LOCATIONS SHOULD TOP OUT AT LEAST IN THE MID
TO UPPER 50S...MAYBE EVEN 60 AT SOME SOUTH OF I-90. RECORD HIGH
FOR THURSDAY IS 59 AT LA CROSSE AND 65 AT ROCHESTER...THUS LA
CROSSE MAY BE DOABLE TO BREAK. TEMPERATURES SHOULD RETURN CLOSER
TO NORMAL FOR FRIDAY INTO THE WEEKEND IN THE WAKE OF THE COLD
FRONT. IF THE 18.00Z ECMWF IS CORRECT...WE COULD EVEN BE BELOW
NORMAL FOR THE WEEKEND.
&&
.AVIATION...THROUGH 18Z MONDAY
1121 AM CST SUN NOV 18 2012
WILL BE WATCHING A MID-LEVEL TROUGH OF LOW PRESSURE AND SURFACE
COLD FRONT APPROACH THE AREA FROM THE PLAINS LATE TONIGHT...AND
THEN ACROSS THE AREA ON MONDAY. THIS WILL SPREAD CLOUDS INTO THE
UPPER MISSISSIPPI RIVER REGION TONIGHT AND THEN PRODUCE SCATTERED
-SHRA ACROSS PORTIONS OF SOUTHEAST MN/NORTHEAST IA INTO SOUTHWEST
WISCONSIN TOWARD MORNING. EXPECTING SCATTERED -SHRA TO REMAIN EAST
OF KRST BUT DID INCLUDE A VCSH MENTION AT KLSE AFTER 11Z SINCE
THIS IS WHERE BETTER SURGE OF MOISTURE TRANSPORT WILL EXIST.
PLAN ON VFR CONDITIONS THROUGH THE PERIOD WITH CIGS EXPECTED TO
REMAIN AOA 4500 FT AGL.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
212 AM CST SUN NOV 18 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...DAS