Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/29/15
AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
222 AM PST TUE JAN 27 2015
.SYNOPSIS...A STORM SYSTEM OFF THE SOUTHERN CALIFORNIA COAST WILL
MOVE NORTH BRINGING A CHANCE OF SHOWERS TO MUCH OF THE CENTRAL
CALIFORNIA INTERIOR THROUGH THE AFTERNOON HOURS. DRY WEATHER WILL
RETURN BY WEDNESDAY...HOWEVER...ANOTHER STORM WILL BRING A RENEWED
CHANCE OF SHOWERS TO MAINLY THE MOUNTAINS AND DESERT WEDNESDAY INTO
FRIDAY.
&&
.DISCUSSION...AN UPPER LOW OFF THE SOUTHERN CALIFORNIA COASTLINE
CONTINUES TO BRING LIGHT TO MODERATE RAIN SHOWERS TO MUCH OF THE
REGION. THE HEAVIEST RAIN WAS OBSERVED IN KERN COUNTY IN THE PAST
6 HOURS...WHERE DESERT AND MOUNTAIN LOCATIONS PICKED UP BETWEEN A
QUARTER OF AN INCH TO NEARLY TWO-THIRDS OF AN INCH.
OTHERWISE...MANY VALLEY LOCATIONS FROM TULARE AND KINGS COUNTY
SOUTHWARD PICKED UP A FEW HUNDREDTHS OF AN INCH TO A TENTH OF AN
INCH. THE HIGH RES ARW...NMM...AND HRRR ALL INDICATE THAT SHOWERS
WILL CONTINUE TO SPREAD NORTHWARD...HOWEVER VERY LITTLE
ACCUMULATION IS EXPECTED. THIS ACTIVITY IS FORECAST TO CONTINUE
INTO THE EARLY AFTERNOON HOURS...WITH RAIN AND SNOW SHOWERS
CONTINUING OVER THE SIERRA NEVADA INTO THE EVENING HOURS...AS THE
UPPER LOW SHIFTS QUICKLY NORTHEAST OUT OF THE REGION.
SNOW LEVELS WITH THIS STORM WILL REMAIN AROUND 7,500 FEET WITH A
FEW INCHES POSSIBLE OVER SIERRA CREST.
HIGH PRESSURE WILL BRIEFLY BUILD OVER CALIFORNIA ON WEDNESDAY
BEFORE A WEAK UPPER TROUGH IMPACTS THE REGION THURSDAY INTO
FRIDAY. THE UPPER TROUGH WILL BECOME A CLOSED LOW ON FRIDAY AND
TRAVEL SLOWLY SOUTHEAST INTO SOUTHERN CALIFORNIA ON FRIDAY AND
INTO ARIZONA EARLY SATURDAY MORNING. THIS WILL BRING A CHANCE FOR
RAIN AND SNOW SHOWERS TO THE SIERRA NEVADA THURSDAY AND
FRIDAY...AND A SLIGHT CHANCE OF SHOWERS TO THE KERN COUNTY DESERT
ON FRIDAY AS THE LOW SHIFTS SOUTH INTO SOUTHERN CALIFORNIA. THE
ENSEMBLE MEAN TRENDS HAVE BEEN VERY INCONSISTENT WITH THE TRACK OF
THIS LOW...GIVING FORECASTERS VERY LITTLE CONFIDENCE IN
MEASUREABLE RAIN...ESPECIALLY FOR THE DESERT.
ONCE THE UPPER LOW EXITS EAST...HIGH PRESSURE WILL BUILD OVER THE
REGION SATURDAY INTO SUNDAY...WITH THE OPERATIONAL AND ENSEMBLE
MEANS ALL IN AGREEMENT. THE BEGINNING OF NEXT WEEK LOOKS A BIT
LESS CERTAIN...AS NCEPS GLOBAL ENSEMBLE SHOWING VERY LOW
PREDICABILITY FOR THE UPPER LEVEL PATTERN FOR THE BEGINNING OF
NEXT WEEK. REGARDLESS...BOTH THE GFS AND ECMWF ARE INDICATING DRY
WEATHER.
LASTLY...WITH THE LIGHT RAIN SHOWERS EXPERIENCED IN THE VALLEY
TODAY...PATCHY FOG WILL ONCE AGAIN BE POSSIBLE THROUGH MANY VALLEY
LOCATIONS STARTING AS EARLY AS THURSDAY. PATCHY FOG WILL BE
POSSIBLE EACH NIGHT AND EARLY MORNING FROM THURSDAY INTO EARLY
NEXT WEEK.
&&
.AVIATION...
LOCAL MVFR VISIBILITIES AND MOUNTAIN OBSCURATIIONS IN SHOWERS
THROUGH 00Z WEDNESDAY. OTHERWISE VFR CONDITIONS FOR THE NEXT 24
HOURS.
&&
.AIR QUALITY ISSUES...
ON TUESDAY JANUARY 27 2015... FIREPLACE/WOOD STOVE BURNING STATUS
IS: NO BURNING UNLESS REGISTERED IN FRESNO... KERN... KINGS AND
TULARE COUNTIES.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.CERTAINTY...
THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS MEDIUM.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM.
THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED
BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD.
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL
INFORMATION AND/OR TO PROVIDE FEEDBACK.
&&
.CLIMATE...
RECORDS
SITE DATE HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR
KFAT 01-27 70:1934 39:1963 52:2012 25:1949
KFAT 01-28 78:1986 41:1963 50:2003 23:1975
KFAT 01-29 73:1960 43:2002 55:1911 24:1902
KBFL 01-27 75:1928 37:1963 51:2012 24:1904
KBFL 01-28 77:1988 47:1957 52:1981 27:1957
KBFL 01-29 74:1986 42:2002 54:1986 27:1903
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
PUBLIC...RILEY
AVN/FW...BEAN
SYNOPSIS...RILEY
WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
411 PM CST TUE JAN 27 2015
.SHORT TERM...
304 PM CST
THROUGH THURSDAY...
PRIMARY CONCERN IN THE NEAR TERM REVOLVES AROUND THE STRATUS DECK
CURRENTLY OVER THE SOUTHWESTERN 2/3RDS OF THE CWA. WOULD ANTICIPATE
A CONTINUED VERY SLOW CLEARING FROM THE EAST FOR A COUPLE MORE HOURS
BEFORE LOW LEVEL FLOW DIMINISHES THIS EVENING BEFORE BACKING TO
SOUTHERLY OVERNIGHT...WHICH MAY WELL SEND STRATUS SLOSHING BACK
NORTH INTO AREAS THAT HAD PREVIOUSLY CLEARED OUT. TRIED TO REFLECT A
TREND LIKE THIS IN THE HOURLY SKY GRIDS AND RESULTANT TEMPERATURE
GRIDS...BUT GIVEN THE POOR MODEL HANDLING OF THIS CLOUDINESS IT
PRETTY MUCH GUARANTEED THAT OUR CURRENT SKY GRIDS WILL BE WRONG
SOMEWHERE AND NEED UPDATING WITH ACCOMPANYING CHANGES NEEDED IN
TEMPS TONIGHT. WHERE SKIES BECOME/STAY CLEAR TONIGHT COULD SEE
FREEZING GROUND FOG DEVELOP GIVEN THE LIGHT WINDS...BUT WILL LET
EVENING SHIFT WATCH TRENDS AND ADD FREEZING FOG AS NEEDED.
FOR WEDNESDAY HAVE OPTED TO BE OPTIMISTIC IN PUSHING STRATUS NORTH
AND BREAKING IT UP IN THE MORNING BUT THIS VERY WELL MAY END UP
BEING TOO OPTIMISTIC. ASSUMING THERE IS SOME SUNSHINE TOMORROW PRIOR
TO THE ARRIVAL OF EXTENSIVE MID AND HIGH LEVEL CLOUDINESS THEN HIGHS
COULD PUSH WELL INTO THE 30S...PARTICULARLY IN THE LESS SNOW COVERED
AND MORE URBANIZED AREAS. DEVELOPING LOW PRESSURE TO OUR WEST
SHOULD RESULT IN TIGHTENING PRESSURE GRADIENT AND STRENGTHENING
SOUTHERLY WINDS WEDNESDAY.
IZZI
&&
.LONG TERM...
304 PM CST
THURSDAY NIGHT THROUGH TUESDAY...
BRISK SOUTH WINDS...WARM AIR ADVECTION...AND CLOUD COVER IN ADVANCE
OF THE SYSTEM WEDNESDAY NIGHT SHOULD RESULT IN NEARLY STEADY TEMPS
IN THE EVENING AND PROBABLY RISING A BIT OVERNIGHT. COULD SEE A BIT
OF LIGHT RAIN OR DRIZZLE IN THE WARM SECTOR WEDNESDAY NIGHT FOLLOWED
BY SOME POTENTIAL FOR A BIT OF WRAP AROUND RAIN OR SNOW SHOWERS
THURSDAY ON THE BACK SIDE OF THE SYSTEM. STILL LOOKS LIKE PRETTY
LIMITED MOISTURE WITH THE SYSTEM AND HIGHEST QPF FOCUSED TO OUR
NORTH WITH LIGHT AMOUNTS IN OUR CWA AND ONLY MINIMAL THREAT OF ANY
ACCUMULATED FROZEN/FREEZING PRECIP GIVEN THE FORECAST TRACK AND
TEMPS.
SHOT OF SEASONABLY COLD AIR WILL KNOCK TEMPS TO JUST A HAIR BELOW
AVERAGE FRIDAY. VIGOROUS ALBERTA CLIPPER IS FORECAST TO RESULT IN
AN AMPLIFYING LONG WAVE TROUGH OVER THE CENTRAL CONUS THIS WEEKEND.
STILL SOME LARGE SPREAD BETWEEN MODELS WITH RESPECT TO THE DETAILS
THIS WEEKEND...BUT THERE HAS BEEN SOME AGREEMENT THE PAST COUPLE
DAYS ON THE GENERAL IDEA OF A LARGE SWATH OF ACCUMULATING SNOW
POTENTIALLY AFFECTING THE REGION SAT NIGHT INTO SUNDAY. ARCTIC AIR
IS FORECAST TO SURGE SOUTH INTO THE AREA IN THE WAKE OF THIS SYSTEM
EARLY NEXT WEEK...BUT THE DURATION AND MAGNITUDE OF THIS ARCTIC
INTRUSION ARE DEPENDENT ON WHICH MODEL YOU LOOK AT MEANING FAIRLY
LOW FORECAST CONFIDENCE AT THIS POINT.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* GUSTY SSELY WINDS TOMORROW.
* CHANCE FOR MVFR CIGS OR VIS LATE TONIGHT.
KREIN
//DISCUSSION...UPDATED 18Z...
BROAD MVFR STRATUS DECK BLANKETS THE REGION TODAY BUT HAS BEEN
STEADILY ERODING FROM THE NORTHEAST...WITH CLEARING SKIES MAKING
PROGRESS DOWN LAKE MICHIGAN THIS MORNING AND INTO THE CHICAGO AREA
EARLY THIS AFTERNOON. CLOUD BEARING FLOW OUT OF THE NORTHEAST THIS
MORNING WILL BACK TO THE NORTH THIS AFTERNOON AND EVENING SO EXPECT
THE PROGRESS OF THE CLEARING TO SLOW SOME...AND MAY EVEN REVERSE
TONIGHT AS A SURFACE RIDGE BUILDS ACROSS INDIANA WITH FLOW BECOMING
MORE SOUTHERLY. SURFACE WINDS WILL GENERALLY DECREASE FROM MID
AFTERNOON ON AS THE SURFACE HIGH NEARS...AND GO LIGHT AND
VARIABLE FOR A PERIOD THIS EVENING AND OVERNIGHT...BEFORE TURNING
SOUTH/SOUTH-SOUTHEAST TOMORROW. GUSTY WINDS PUSHING 20 KT ARE
EXPECTED TOMORROW AFTERNOON.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* LOW-MEDIUM CONFIDENCE IN CIG/VIS TRENDS OVERNIGHT.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...CHANCE OF RAIN/DRIZZLE. MVFR/IFR POSSIBLE.
THURSDAY...CHANCE OF RAIN/SNOW. MVFR LIKELY/IFR POSSIBLE.
FRIDAY AND SATURDAY...PRIMARILY VFR. CHANCE OF SNOW SATURDAY
NIGHT.
SUNDAY...CHANCE OF LIGHT SNOW. IFR POSSIBLE.
MONDAY...MVFR CIGS POSSIBLE.
RATZER
&&
.MARINE...
318 PM CST
LIGHTER NORTHERLY WINDS IN PLACE THIS AFTERNOON AS HIGH PRESSURE
SPANS THE REGION...WILL FURTHER DIMINISH THIS EVENING AS THIS HIGH
MOVES OVERHEAD. THIS HIGH WILL THEN CONTINUE SOUTHEAST TOWARDS THE
OHIO VALLEY TONIGHT AS A TROUGH OF LOW PRESSURE MOVES EAST ACROSS
THE CENTRAL PLAINS. THIS WILL HELP THE WINDS TO TURN BACK MORE
SOUTHERLY AND THEN BEGIN TO SLOWLY INCREASE LATER TONIGHT INTO
WEDNESDAY. THIS INCREASING TREND WILL CONTINUE THROUGHOUT THE DAY
WEDNESDAY...WITH SOUTHERLY WINDS REALLY INCREASING DURING THE
AFTERNOON TIME FRAME. THIS WILL LIKELY CREATE WINDS HAZARDOUS FOR
SMALL CRAFT...AND SO HAVE ISSUED A SMALL CRAFT ADVISORY FOR
WEDNESDAY AFTERNOON THROUGH LATE WEDNESDAY NIGHT WHEN WINDS WILL
DIMINISH WITH THE APPROACHING LOW PRESSURE. THIS WILL LIKELY BE
BRIEF AS WINDS WILL QUICKLY INCREASE ONCE AGAIN ON THE BACKSIDE OF
THIS SYSTEM THURSDAY. ALSO...SOUTHERLY WINDS ACROSS THE SOUTHERN
HALF OF THE LAKE COULD HOVER AROUND 30 KT A FOR A BRIEF WINDOW
WEDNESDAY NIGHT. WILL NEED TO MONITOR TRENDS DURING THIS
PERIOD...BUT WILL MAKE MENTION OF OCCASIONAL GALE FORCE GUSTS
DURING THIS TIME. EXPECT STRONG WINDS TO BE IN PLACE ON
THURSDAY...REALLY INCREASING INTO THE AFTERNOON AND EVENING HOURS.
GALES ARE APPEARING LIKELY FOR THE ENTIRE LAKE DURING THIS
TIME...EVEN FOR THE NEARSHORE WATERS...BUT WITH SPEEDS DIMINISHING
ONCE AGAIN LATE THURSDAY NIGHT INTO FRIDAY.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...NOON WEDNESDAY TO 4 AM THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
ISSUED BY NATIONAL WEATHER SERVICE CHICAGO IL
341 PM CST Tue Jan 27 2015
.SHORT TERM...(Through Wednesday afternoon)
ISSUED AT 255 PM CST TUE JAN 27 2015
MAIN CHALLENGE IN THE SHORT/NEAR TERM REVOLVES AROUND CLOUD COVER
TONIGHT...WINDS AND TEMPS ON WEDNESDAY. A SURFACE RIDGE IS IN PLACE
OVERHEAD...AND SATELLITE PICTURES SHOW LOWER CLOUDS ERODING FROM THE
NORTHEAST THIS AFTERNOON AS DRIER AIR FILTERS IN. BEST CHANCES FOR
EROSION WILL BE FOR EASTERN AREAS WHERE THIS DRIER AIR IS MAKING
BETTER HEADWAY. RAW MODEL GUIDANCE CONTINUES TO ADVERTISE CLEARING
MUCH SOONER THIS EVENING AREA-WIDE...WHILE RAP TIME HEIGHTS SUGGEST
IT WILL TAKE UNTIL LATER TONIGHT FOR THIS TO OCCUR...ESPECIALLY
NORTH OF I-72. MODEL SOUNDINGS SUGGEST THAT THIS LOWER LEVEL
MOISTURE WILL REMAIN TRAPPED BELOW A SUBSIDENCE INVERSION...AND THAT
IT WILL AT LEAST HOLD FIRM THROUGH THE EVENING HOURS. CLOUD BEARING
WINDS WILL BE TURNING MORE NORTHERLY AS WELL...WHICH WOULD SUPPORT
CLOUDS HANGING ON ALONG AND WEST OF HIGHWAY 51. SURFACE HIGH
PRESSURE TONIGHT WILL SHIFT OFF THE EAST TONIGHT AS THE UPPER RIDGE
IN THE PLAINS MOVE EAST AND CONTINUES TO DEAMPLIFY. EXPECT WINDS TO
SHIFT TO THE SE OVERNIGHT...WITH LOWS IN THE EAST IN THE UPPER TEENS
TO NEAR 20...WITH 20S HOLDING WEST WHERE CLOUD COVER IS EXPECTED TO
BE MORE PREVALENT.
THURSDAY...ATTENTION SHIFTS TO UPPER LEVEL LOW PRESSURE MOVING
THROUGH THE GREAT BASIN THIS AFTERNOON. THE UPPER TROUGH MOVES INTO
THE PLAINS RIDGE WHILE ADDITIONAL PACIFIC ENERGY MOVES INTO THE
NORTHERN PLAINS. LOW LEVEL WARM ADVECTION ENSUES IN THE
SOUTHWESTERLY FLOW AHEAD OF THESE SYSTEM .IT APPEARS THAT NOT ALL OF
OF THIS LOW LEVEL WARMING WILL NOT TRANSLATE TO THE SURFACE WITH A
FAIRLY STRONG INVERSION HOLDING...BUT DO EXPECT SOME WARMING FROM
TODAY`S READINGS...ESPECIALLY FOR SOUTHERN AND WESTERN AREAS WHERE
MID 40S LOOK LIKE A DECENT BET. AREAS NORTH AND EAST WILL REMAIN ON
THE COOLER SIDE STRUGGLING TO REACH 40. AHEAD OF THESE TWO
DISTURBANCES SURFACE LOW PRESSURE OF 1005 MB COMBINES WITH THE
DEPARTING HIGH TO CREATE A MODEST PRESSURE GRADIENT ACROSS THE AREA.
A VERY STRONG LOW LEVEL JET SETS UP LATE IN THE AFTERNOON...BUT
GIVEN THE LOW LEVEL INVERSION...EXPECT A BREEZY DAY WITH GUSTS IN
THE 25 KT RANGE.
KMD
&&
.LONG TERM...(Wednesday Night through Tuesday)
ISSUED AT 340 PM CST TUE JAN 27 2015
WEDNESDAY NIGHT THROUGH SATURDAY...
A WINDY AND MILD NIGHT IS IN STORE ON WEDNESDAY NIGHT AS LOW
PRESSURE QUICKLY MOVES JUST NORTH OF THE CWA. STRONG PRESSURE
FALLS DUE TO TIGHTENING GRADIENT BETWEEN ADVANCING LOW AND
DEPARTING HIGH PRESSURE TO THE EAST WILL RESULT IN SUSTAINED
SOUTHERLY WINDS IN THE MID TO HIGH TEENS WITH GUSTS OF 20-25 KT.
TEMPERATURES SHOULD DROP SOME IN THE EVENING BUT THEN ARE LIKELY
TO SLOWLY RISE TOWARD DAYBREAK. THERE IS A DECENT VORT MAX
ASSOCIATED WITH APPROACHING SHORT WAVE TROUGH...BUT GUIDANCE IS
FAIRLY DRY WITH EXCEPTION OF ECMWF AND NAM. MAINTAINED SLIGHT TO
LOW END CHANCE POPS FOR LIGHT RAIN MAINLY AFTER MIDNIGHT. MAY NEED
TO ADD DRIZZLE TO GRIDS.
COLD FRONT TRAILING FROM THE LOW PRESSURE WILL SWEEP ACROSS THE
AREA FROM NW TO SE OVERNIGHT INTO THURSDAY MORNING...SHIFTING
WINDS FROM SOUTHWEST TO NORTHWEST...AND COLD ADVECTION RAMPING UP
BEHIND IT. HAVE LOW POPS FOR MOST OF THE CWA IN THE MORNING...BUT
ANY PRECIP WOULD LIKELY BE LIGHT RAIN DESPITE COLD ADVECTION AS
SURFACE TEMPERATURES WOULDNT COOL QUICK ENOUGH FROM EARLY HIGHS IN
THE UPPER 30S TO MID 40S...WARMEST FAR SOUTHEAST. BIGGER STORY
WILL BE STRONG ISALLOBARIC PRESSURE RISES BEHIND FRONT RESULTING
IN NORTHWEST WINDS GUSTING TO 30-35 MPH MUCH OF THE MORNING AND
AFTERNOON. WINDS WILL GRADUALLY DIMINISH THURSDAY NIGHT AS
EXPANSIVE HIGH PRESSURE SPREADS SOUTHEAST. EXPECT LOWS IN THE
UPPER TEENS TO MID 20S BY EARLY FRIDAY...RECOVERING TO SLIGHTLY
BELOW CLIMO LOW-MID 30S UNDER LARGE CANADIAN HIGH. THE HIGH WILL
SLIDE SOUTHEAST ON SATURDAY...ALLOWING TEMPS TO WARM SLIGHTLY TO
THE MID TO UPPER 30S.
SATURDAY NIGHT THROUGH TUESDAY...
ATTENTION TURNS TO EJECTION OF CLOSED UPPER LOW OVER THE DESERT
SOUTHWEST AS MORE OF AN OPEN WAVE SATURDAY NIGHT INTO
SUNDAY...WITH ASSOCIATED WEAK SURFACE LOW POSSIBLY MOVING TOWARD
THE LOWER OR MID MS VALLEY THEN OH VALLEY BY SUNDAY EVENING. WITH
IT BEING STILL OVER 100 HRS OUT...GUIDANCE VARIES ON PLACEMENT OF
SURFACE LOW...BUT DECENT AGREEMENT IN OPERATIONAL MODELS AND
ENSEMBLES OF BROAD WARM ADVECTION/ISENTROPIC ASCENT WITH THIS
SYSTEM. THIS YIELDS THE POTENTIAL FOR FAIRLY LONG DURATION
PRECIPITATION. AT THIS POINT...THERMAL PROFILES APPEAR COLD ENOUGH
FOR SNOW ACROSS THE CWA...BUT FARTHER NORTHWEST/STRONGER LOW COULD
INTRODUCE P-TYPE CONCERNS...ESPECIALLY IN THE FAR SOUTHEAST. WAY
TOO EARLY TO DISCUSS POTENTIAL SNOW ACCUMULATIONS...BUT THIS
PERIOD BEARS WATCHING. BEHIND THIS SYSTEM...MODELS HAVE BEEN
WAFFLING ON INTENSITY OF A POTENTIAL SHOT OF ARCTIC AIR EARLY NEXT
WEEK AS PIECE OF POLAR VORTEX ROTATES SOUTH OF HUDSON BAY. BRUNT
OF THE ARCTIC BLAST MAY BE DIRECTED FARTHER EAST...BUT STILL LOOKS
LIKE THERE COULD BE A PERIOD OF WELL BELOW NORMAL TEMPERATURES
EARLY NEXT WEEK.
RC
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 1141 AM CST TUE JAN 27 2015
MAIN AVIATION CONCERN REVOLVES AROUND EXISTING MVFR AND IFR CIGS.
IFR CIGS ARE BECOMING LESS COMMON ACROSS THE TERMINALS AS DRIER
AIR SLOWLY FILTERS IN FROM THE NORTHEAST. EXPECT KBMI WILL HANG
ONTO IFR A BIT LONGER BEFORE TRANSITION MVFR CIGS IN THE 1000-1500
FT RANGE. CHALLENGE THEN TURNS TO HOW QUICKLY THE LOWER CLOUD BASE
ERODES. HRRR AND RAP GUIDANCE ARE A BIT MIXED TO HOW QUICKLY THIS
OCCURS. THE GENERAL FEELING IS THAT SOMETIME THIS EVENING THE MVFR
DECK WILL LIFT ABOVE 2000 FT AND SCATTER OUT AS THE HRRR
SUGGESTS...BUT CONFIDENCE ON THIS TIMING IS MEDIUM. HIGHEST CONFIDENCE
ON TIMING THIS OCCURRENCE IS AT KCMI AND EASTERN LOCATIONS WHERE
DRIER AIR WILL MORE READILY ADVECT IN. MEANWHILE THE RAP AND NAM
HOLD ONTO THE CLOUDS THROUGH 6Z OR SLIGHTLY LATER AS A LOW LEVEL
INVERSION REMAINS IN PLACE. WINDS OVERNIGHT WILL VEER TO THE
SOUTHEAST AND WEAKEN BEFORE STRENGTHENING TOMORROW MORNING. SOME
PATCHY FOG MAY DEVELOP AFTER CLOUDS CLEAR BUT HELD OFF ANY MENTION
AT THIS POINT.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...kmd
LONG TERM...RC
AVIATION...KMD
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
304 PM CST TUE JAN 27 2015
.SHORT TERM...
304 PM CST
THROUGH THURSDAY...
PRIMARY CONCERN IN THE NEAR TERM REVOLVES AROUND THE STRATUS DECK
CURRENTLY OVER THE SOUTHWESTERN 2/3RDS OF THE CWA. WOULD ANTICIPATE
A CONTINUED VERY SLOW CLEARING FROM THE EAST FOR A COUPLE MORE HOURS
BEFORE LOW LEVEL FLOW DIMINISHES THIS EVENING BEFORE BACKING TO
SOUTHERLY OVERNIGHT...WHICH MAY WELL SEND STRATUS SLOSHING BACK
NORTH INTO AREAS THAT HAD PREVIOUSLY CLEARED OUT. TRIED TO REFLECT A
TREND LIKE THIS IN THE HOURLY SKY GRIDS AND RESULTANT TEMPERATURE
GRIDS...BUT GIVEN THE POOR MODEL HANDLING OF THIS CLOUDINESS IT
PRETTY MUCH GUARANTEED THAT OUR CURRENT SKY GRIDS WILL BE WRONG
SOMEWHERE AND NEED UPDATING WITH ACCOMPANYING CHANGES NEEDED IN
TEMPS TONIGHT. WHERE SKIES BECOME/STAY CLEAR TONIGHT COULD SEE
FREEZING GROUND FOG DEVELOP GIVEN THE LIGHT WINDS...BUT WILL LET
EVENING SHIFT WATCH TRENDS AND ADD FREEZING FOG AS NEEDED.
FOR WEDNESDAY HAVE OPTED TO BE OPTIMISTIC IN PUSHING STRATUS NORTH
AND BREAKING IT UP IN THE MORNING BUT THIS VERY WELL MAY END UP
BEING TOO OPTIMISTIC. ASSUMING THERE IS SOME SUNSHINE TOMORROW PRIOR
TO THE ARRIVAL OF EXTENSIVE MID AND HIGH LEVEL CLOUDINESS THEN HIGHS
COULD PUSH WELL INTO THE 30S...PARTICULARLY IN THE LESS SNOW COVERED
AND MORE URBANIZED AREAS. DEVELOPING LOW PRESSURE TO OUR WEST
SHOULD RESULT IN TIGHTENING PRESSURE GRADIENT AND STRENGTHENING
SOUTHERLY WINDS WEDNESDAY.
IZZI
&&
.LONG TERM...
304 PM CST
THURSDAY NIGHT THROUGH TUESDAY...
BRISK SOUTH WINDS...WARM AIR ADVECTION...AND CLOUD COVER IN ADVANCE
OF THE SYSTEM WEDNESDAY NIGHT SHOULD RESULT IN NEARLY STEADY TEMPS
IN THE EVENING AND PROBABLY RISING A BIT OVERNIGHT. COULD SEE A BIT
OF LIGHT RAIN OR DRIZZLE IN THE WARM SECTOR WEDNESDAY NIGHT FOLLOWED
BY SOME POTENTIAL FOR A BIT OF WRAP AROUND RAIN OR SNOW SHOWERS
THURSDAY ON THE BACK SIDE OF THE SYSTEM. STILL LOOKS LIKE PRETTY
LIMITED MOISTURE WITH THE SYSTEM AND HIGHEST QPF FOCUSED TO OUR
NORTH WITH LIGHT AMOUNTS IN OUR CWA AND ONLY MINIMAL THREAT OF ANY
ACCUMULATED FROZEN/FREEZING PRECIP GIVEN THE FORECAST TRACK AND
TEMPS.
SHOT OF SEASONABLY COLD AIR WILL KNOCK TEMPS TO JUST A HAIR BELOW
AVERAGE FRIDAY. VIGOROUS ALBERTA CLIPPER IS FORECAST TO RESULT IN
AN AMPLIFYING LONG WAVE TROUGH OVER THE CENTRAL CONUS THIS WEEKEND.
STILL SOME LARGE SPREAD BETWEEN MODELS WITH RESPECT TO THE DETAILS
THIS WEEKEND...BUT THERE HAS BEEN SOME AGREEMENT THE PAST COUPLE
DAYS ON THE GENERAL IDEA OF A LARGE SWATH OF ACCUMULATING SNOW
POTENTIALLY AFFECTING THE REGION SAT NIGHT INTO SUNDAY. ARCTIC AIR
IS FORECAST TO SURGE SOUTH INTO THE AREA IN THE WAKE OF THIS SYSTEM
EARLY NEXT WEEK...BUT THE DURATION AND MAGNITUDE OF THIS ARCTIC
INTRUSION ARE DEPENDENT ON WHICH MODEL YOU LOOK AT MEANING FAIRLY
LOW FORECAST CONFIDENCE AT THIS POINT.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* MVFR CIGS CLEARING THE TERMINALS EARLY THIS AFTERNOON...BUT
LIKELY REMAIN NEARBY THIS EVENING AND TONIGHT.
BMD
//DISCUSSION...UPDATED 18Z...
BROAD MVFR STRATUS DECK BLANKETS THE REGION TODAY BUT HAS BEEN
STEADILY ERODING FROM THE NORTHEAST...WITH CLEARING SKIES MAKING
PROGRESS DOWN LAKE MICHIGAN THIS MORNING AND INTO THE CHICAGO AREA
EARLY THIS AFTERNOON. CLOUD BEARING FLOW OUT OF THE NORTHEAST THIS
MORNING WILL BACK TO THE NORTH THIS AFTERNOON AND EVENING SO EXPECT
THE PROGRESS OF THE CLEARING TO SLOW SOME...AND MAY EVEN REVERSE
TONIGHT AS A SURFACE RIDGE BUILDS ACROSS INDIANA WITH FLOW BECOMING
MORE SOUTHERLY. SURFACE WINDS WILL GENERALLY DECREASE FROM MID
AFTERNOON ON AS THE SURFACE HIGH NEARS...AND GO LIGHT AND
VARIABLE FOR A PERIOD THIS EVENING AND OVERNIGHT...BEFORE TURNING
SOUTH/SOUTH-SOUTHEAST TOMORROW. GUSTY WINDS PUSHING 20 KT ARE
EXPECTED TOMORROW AFTERNOON.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN PERIODS OF VFR THIS AFTERNOON...LOW-MEDIUM
CONFIDENCE IN CIG TRENDS OVERNIGHT.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...CHANCE OF RAIN/DRIZZLE. MVFR/IFR POSSIBLE.
THURSDAY...CHANCE OF RAIN/SNOW. MVFR LIKELY/IFR POSSIBLE.
FRIDAY AND SATURDAY...PRIMARILY VFR. CHANCE OF SNOW SATURDAY
NIGHT.
SUNDAY...CHANCE OF LIGHT SNOW. IFR POSSIBLE.
MONDAY...MVFR CIGS POSSIBLE.
RATZER
&&
.MARINE...
213 AM CST
MARINE CONCERNS ON LAKE MICHIGAN ARE A PERIOD OF STRONG SOUTH WINDS
WEDNESDAY AFTERNOON AND NIGHT...THEN A SHIFT TO STRONG NORTH TO
NORTHWEST WINDS THURSDAY AFTERNOON INTO EARLY FRIDAY...WITH THE
POTENTIAL FOR A PERIOD OF NORTHWEST GALES ESPECIALLY THURSDAY
AFTERNOON AND THURSDAY EVENING.
IN THE NEAR TERM...RELATIVELY QUIET WEATHER ACROSS THE LAKE EARLY
THIS MORNING AS A WEAKENING SURFACE TROUGH OVER ILLINOIS AND THE
LOWER OHIO VALLEY CONTINUES TO MOVE OFF TO THE SOUTHEAST...ALLOWING
WEAK HIGH PRESSURE TO SETTLE ACROSS THE AREA FROM THE NORTH TODAY.
LOOKING TO THE WEST...AN AREA OF LOW PRESSURE DEVELOPING IN THE LEE
OF THE CANADIAN ROCKIES WILL SLIDE SOUTHEAST INTO THE PLAINS
THROUGH TONIGHT...THEN WILL MOVE SLOWLY EAST TOWARD LAKE MICHIGAN
WEDNESDAY AND WEDNESDAY NIGHT. IN RESPONSE TO PRESSURE FALLS AHEAD
OF THE LOW...THE GRADIENT WILL TIGHTEN ACROSS LAKE MICHIGAN
WEDNESDAY WITH SOUTH WINDS RAMPING UP INTO THE 30 KT RANGE BY LATE
AFTERNOON AND EVENING. WINDS WILL DIMINISH BRIEFLY EARLY THURSDAY
MORNING AS THE LOW PRESSURE CENTER AND COLD FRONTAL TROUGH CROSS THE
LAKE...BEFORE WINDS SHIFT TO THE NORTH-NORTHWEST AND INCREASE
QUICKLY BACK INTO THE 30-35 KT RANGE THURSDAY AFTERNOON. FORECAST
SOUNDINGS INDICATE THE POTENTIAL FOR GALES THURSDAY AFTERNOON AND
EVENING IN THE STRONG PRESSURE RISES AND COLD ADVECTION BEHIND THE
DEPARTING LOW AND COLD FRONT. THESE STRONG WINDS WILL CONTINUE INTO
EARLY FRIDAY...BEFORE DIMINISHING AS A BROAD AREA OF HIGH PRESSURE
SPREADS INTO THE AREA BY FRIDAY EVENING. THE HIGH WILL SLOWLY MOVE
OFF TO THE EAST ON SATURDAY...WITH A WEAK LOW EXPECTED TO PASS
ACROSS THE NORTHERN LAKES SATURDAY NIGHT AND TRAIL A COLD FRONT
ACROSS LAKE MICHIGAN THROUGH SUNDAY.
FOR THE ILLINOIS AND NORTHWEST INDIANA NEARSHORE WATERS SMALL CRAFT
ADVISORY CONDITIONS LOOK TO DEVELOP WEDNESDAY AFTERNOON AND CONTINUE
THROUGH THURSDAY MORNING...WITH A BRIEF BREAK BEFORE HIGH WIND/WAVE
CONDITIONS DEVELOP AGAIN BY EARLY THURSDAY AFTERNOON. HIGH WAVES
WOULD LIKELY LINGER THROUGH MUCH OF FRIDAY...ESPECIALLY ALONG THE
INDIANA SHORE EAST OF GARY.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...NOON WEDNESDAY TO 4 AM THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
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WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
ISSUED BY NATIONAL WEATHER SERVICE CHICAGO IL
259 PM CST Tue Jan 27 2015
.SHORT TERM...(Through wednesday afternoon)
ISSUED AT 255 PM CST TUE JAN 27 2015
MAIN CHALLENGE IN THE SHORT/NEAR TERM REVOLVES AROUND CLOUD COVER
TONIGHT...WINDS AND TEMPS ON WEDNESDAY. A SURFACE RIDGE IS IN PLACE
OVERHEAD...AND SATELLITE PICTURES SHOW LOWER CLOUDS ERODING FROM THE
NORTHEAST THIS AFTERNOON AS DRIER AIR FILTERS IN. BEST CHANCES FOR
EROSION WILL BE FOR EASTERN AREAS WHERE THIS DRIER AIR IS MAKING
BETTER HEADWAY. RAW MODEL GUIDANCE CONTINUES TO ADVERTISE CLEARING
MUCH SOONER THIS EVENING AREA-WIDE...WHILE RAP TIME HEIGHTS SUGGEST
IT WILL TAKE UNTIL LATER TONIGHT FOR THIS TO OCCUR...ESPECIALLY
NORTH OF I-72. MODEL SOUNDINGS SUGGEST THAT THIS LOWER LEVEL
MOISTURE WILL REMAIN TRAPPED BELOW A SUBSIDENCE INVERSION...AND THAT
IT WILL AT LEAST HOLD FIRM THROUGH THE EVENING HOURS. CLOUD BEARING
WINDS WILL BE TURNING MORE NORTHERLY AS WELL...WHICH WOULD SUPPORT
CLOUDS HANGING ON ALONG AND WEST OF HIGHWAY 51. SURFACE HIGH
PRESSURE TONIGHT WILL SHIFT OFF THE EAST TONIGHT AS THE UPPER RIDGE
IN THE PLAINS MOVE EAST AND CONTINUES TO DEAMPLIFY. EXPECT WINDS TO
SHIFT TO THE SE OVERNIGHT...WITH LOWS IN THE EAST IN THE UPPER TEENS
TO NEAR 20...WITH 20S HOLDING WEST WHERE CLOUD COVER IS EXPECTED TO
BE MORE PREVALENT.
THURSDAY...ATTENTION SHIFTS TO UPPER LEVEL LOW PRESSURE MOVING
THROUGH THE GREAT BASIN THIS AFTERNOON. THE UPPER TROUGH MOVES INTO
THE PLAINS RIDGE WHILE ADDITIONAL PACIFIC ENERGY MOVES INTO THE
NORTHERN PLAINS. LOW LEVEL WARM ADVECTION ENSUES IN THE
SOUTHWESTERLY FLOW AHEAD OF THESE SYSTEM .IT APPEARS THAT NOT ALL OF
OF THIS LOW LEVEL WARMING WILL NOT TRANSLATE TO THE SURFACE WITH A
FAIRLY STRONG INVERSION HOLDING...BUT DO EXPECT SOME WARMING FROM
TODAY`S READINGS...ESPECIALLY FOR SOUTHERN AND WESTERN AREAS WHERE
MID 40S LOOK LIKE A DECENT BET. AREAS NORTH AND EAST WILL REMAIN ON
THE COOLER SIDE STRUGGLING TO REACH 40. AHEAD OF THESE TWO
DISTURBANCES SURFACE LOW PRESSURE OF 1005 MB COMBINES WITH THE
DEPARTING HIGH TO CREATE A MODEST PRESSURE GRADIENT ACROSS THE AREA.
A VERY STRONG LOW LEVEL JET SETS UP LATE IN THE AFTERNOON...BUT
GIVEN THE LOW LEVEL INVERSION...EXPECT A BREEZY DAY WITH GUSTS IN
THE 25 KT RANGE.
KMD
&&
.LONG TERM...(Tonight through Tuesday)
ISSUED AT 326 AM CST TUE JAN 27 2015
Low clouds to decrease during the evening as 1027 mb high pressure
drifts over IL/IN by overnight. Lows tonight range from upper teens
to near 20F ne counties (where clearing may occur soonest) to mid
20s sw counties. High pressure drifts east into eastern Ohio river
valley by 18Z/noon Wed and get a breezy SSE flow developing over IL
and bringing in milder air with partly to mostly sunny skies. Highs
Wed range from lower 40s eastern IL to the upper 40s to around 50F
from Jacksonville west to the MS river.
Low pressure ejects east from northern Rockies into western Great
Lakes by dawn Thu and pulls cold front east across IL late Wed night
into Thu morning. This to bring chances of light rain overnight Wed
night into Thu morning and possibly lingering over eastern IL Thu
afternoon where light snow could mix in over northern counties
before ending. Lows Wed night of 33-38F with coolest readings in
east central IL. Highs Thu in upper 30s and lower 40s central IL and
mid 40s in southeast IL southeast of I-70.
1040 mb Canadian high pressure moves down into the Midwest Friday
and returns mostly clear to partly cloudy skies and cooler
temperatures Thu night through Fri night. Cooler highs Friday of
30-35F. Most of Saturday now appears dry over central and eastern IL
with chance of light snow/rain moving into west central IL later
Saturday ahead of next storm system. Seasonable highs Saturday in mid
to upper 30s.
00Z extended models show more phasing of southern and northern
stream system this weekend and bring better chances of light snow to
central and southeast IL Sat night into Sunday evening as surface
low deepens ne from southeast Texas into the eastern OH/TN river
valleys. This could bring a few inches of snow accumulations
especially in southeast IL where even a mix of precipitation appears
possible south of Highway 50. Another Canadian high to drift
southeast into IL early next work week bringing colder/below normal
temperatures.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 1141 AM CST TUE JAN 27 2015
MAIN AVIATION CONCERN REVOLVES AROUND EXISTING MVFR AND IFR CIGS.
IFR CIGS ARE BECOMING LESS COMMON ACROSS THE TERMINALS AS DRIER
AIR SLOWLY FILTERS IN FROM THE NORTHEAST. EXPECT KBMI WILL HANG
ONTO IFR A BIT LONGER BEFORE TRANSITION MVFR CIGS IN THE 1000-1500
FT RANGE. CHALLENGE THEN TURNS TO HOW QUICKLY THE LOWER CLOUD BASE
ERODES. HRRR AND RAP GUIDANCE ARE A BIT MIXED TO HOW QUICKLY THIS
OCCURS. THE GENERAL FEELING IS THAT SOMETIME THIS EVENING THE MVFR
DECK WILL LIFT ABOVE 2000 FT AND SCATTER OUT AS THE HRRR
SUGGESTS...BUT CONFIDENCE ON THIS TIMING IS MEDIUM. HIGHEST CONFIDENCE
ON TIMING THIS OCCURRENCE IS AT KCMI AND EASTERN LOCATIONS WHERE
DRIER AIR WILL MORE READILY ADVECT IN. MEANWHILE THE RAP AND NAM
HOLD ONTO THE CLOUDS THROUGH 6Z OR SLIGHTLY LATER AS A LOW LEVEL
INVERSION REMAINS IN PLACE. WINDS OVERNIGHT WILL VEER TO THE
SOUTHEAST AND WEAKEN BEFORE STRENGTHENING TOMORROW MORNING. SOME
PATCHY FOG MAY DEVELOP AFTER CLOUDS CLEAR BUT HELD OFF ANY MENTION
AT THIS POINT.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...kmd
LONG TERM...07
AVIATION...KMD
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
146 PM CST TUE JAN 27 2015
.SHORT TERM...
330 AM CST
THROUGH WEDNESDAY...
INFRARED AND WATER VAPOR SATELLITE LOOPS EARLY THIS MORNING HAVE
SHOWN THE LAST IN A SERIES OF SHEARED VORTICITY MAXIMA TO HAVE MOVED
SOUTHEAST OF THE AREA. LIGHT SNOW ASSOCIATED WITH THESE HAS MAINLY
ENDED. LOW-LEVEL WINDS HAVE ALSO SHIFTED MORE NORTHERLY AS A
SURFACE INDUCED TROUGH AXIS PULLS AWAY. THIS HAS ENDED THE LOW-
LEVEL ISENTROPIC ASCENT AND OMEGA WHICH HELPED TO INDUCE MUCH OF
THE FREEZING DRIZZLE LAST NIGHT. SO WITH THAT HAVE CANCELLED THE
ADVISORY AS THE WIDESPREAD THREAT HAS ENDED GOING INTO THE RUSH
HOUR. ONE HOPEFULLY ONLY SMALL FLY IN THE OINTMENT TO THIS IS THE
CHANCE FOR FREEZING DRIZZLE LINGERING IN MAINLY LAKE AND COOK
COUNTIES...INCLUDING CHICAGO...AS WINDS TURN OFF THE LAKE EARLY
THIS MORNING STEERING IN SOME MARGINAL LAKE-INDUCED INSTABILITY.
THE MKX RADAR IS INDICATING LIGHT ECHOES MOVING WESTWARD THAT
DUAL-POL SUGGESTS IS FREEZING DRIZZLE. RAP PROFILES ARE ONLY
SATURATED ABOUT AS COOL AS -8C ADDING SUPPORT TO THAT. WITH NOT
EXPECTING A SITUATION SUCH AS LAST EVENING GIVEN THE TREATMENT ON
ROADS AND THE DIFFERENT MORE MESOSCALE/LOCALIZED INDUCED
LIFT...FEEL BETTER GOING WITH AN SPS IF NEEDED. EXPECT THE CHANCES
TO END BY 10 AM OR SO AS DRIER AIR CONTINUES TO ADVECT WESTWARD
OVER THE LAKE SEEN BY DEW POINTS NEAR 10F ON THE MICHIGAN SHORE
ALONG WITH AN EAST WIND.
CLOUDS SHOULD BE SLOW TO CLEAR TODAY GIVEN THE CURRENT EXPANSIVENESS
TO THE NORTH AND THE CYCLONIC FLOW CONTINUING THROUGH THIS
MORNING...AS WELL AS AFOREMENTIONED LAKE-ORIENTED FLOW INTO
NORTHEAST ILLINOIS. MESOSCALE MODEL MOISTURE/CONDENSATE FIELDS
INDICATE CLOUDS LINGERING THE LONGEST ACROSS THE ILLINOIS PART OF
THE CWA WITH INDIANA EXPERIENCING NORTHEASTERLY DRY ADVECTION.
HAVE HIGHS ONLY A FEW DEGREES WARMER THAN CURRENT EARLY MORNING
VALUES GIVEN THIS THOUGHT PROCESS. CONFIDENCE IS LOW ON WHETHER
CLEARING OCCURS AREAWIDE LATE THIS AFTERNOON AND EVENING AS
GUIDANCE WOULD SUGGEST...PLUS THERE WILL LIKELY BE CIRRUS
SPREADING IN TOO. THIS INTRODUCES BUST POTENTIAL IN LOW
TEMPERATURES OVER NORTH CENTRAL ILLINOIS WHERE LOW TEENS TO MID
20S COULD OCCUR DEPENDING ON CLOUDS. FEEL MORE CONFIDENT NORTHWEST
INDIANA WILL BE MOSTLY CLEAR AND TOUCH SOME OF THOSE LOWER TO MID
TEENS.
DURING THE DAY WEDNESDAY...A THERMAL RIDGE BUILDS INTO THE AREA AND
EXPECTING AT LEAST SOME SUNSHINE AS SOUTHWESTERLY LOW-LEVEL FLOW
WILL BE ENOUGH TO ADVECT OUT ANY RESIDUAL LOW CLOUDS. THE WARMEST
PART OF THE THERMAL RIDGE REACHES US MORE SO WEDNESDAY NIGHT AND
CLIMATOLOGY FOR FORECAST 925MB TEMPERATURES WOULD KEEP
SURFACE READINGS IN THE 30S FOR MOST OF THE CWA ESPECIALLY WITH
SOME SNOW COVER ALBEIT MINIMAL.
MTF
&&
.LONG TERM...
330 AM CST
WEDNESDAY NIGHT THROUGH MONDAY...
THE NEXT CHANCE FOR PRECIPITATION IS WEDNESDAY NIGHT AND
THURSDAY...AND CONFIDENCE HAS FURTHER INCREASED THAT THIS WILL BE A
LIGHT PRECIPITATION EVENT...AS WELL AS ONE WITH ONLY LIQUID
WEDNESDAY NIGHT IF PRECIPITATION DEVELOPS OVER OUR AREA. A CLOSED
UPPER LOW NEAR LOS ANGELES EARLY THIS MORNING IS STILL FORECAST TO
GET CAUGHT IN THE WESTERLIES AND DAMPEN THE STRONG UPPER RIDGE IN
PLACE OVER THE ROCKIES. A GRADUAL PHASING WITH A NORTHERN STREAM
PROGRESSIVE WAVE IS EXPECTED WEDNESDAY NIGHT THROUGH THURSDAY
OVER THE GREAT LAKES REGION. WHILE THE 27.00 GFS IS MORE
AGGRESSIVE WITH THIS PHASING THAN OTHER 27.00 GUIDANCE...IT ONLY
BRINGS A LITTLE MORE OOMPH FOR PRECIP HERE. THE THERMAL RIDGE
MENTIONED IN THE SHORT TERM SECTION FOR WEDNESDAY IS 2C-6C AT
850-925MB AND SURFACE TEMPERATURES ARE NOT LIKELY TO DROP GIVEN
THE SOUTHERN FLOW AND INCREASING CLOUDS...SO HAVE CHANCES OF RAIN
AND DRIZZLE WEDNESDAY NIGHT AS MOISTURE TRANSPORT DEVELOPS. ON
THURSDAY...TRANSITION TO A LIGHT RAIN AND SNOW MIX AND AT THIS
POINT WPC AND OURSELVES REALLY HAVE NO ACCUMULATIONS FORECAST.
HAVE STILL TRIED TO TAKE INTO ACCOUNT SOME POSSIBLE SLOWING IN THE
FORECAST GIVEN THE CURRENT SIGNIFICANT CLOSED SYSTEM OFF THE
NORTHEAST U.S...AND KEPT PRECIP CHANCES INTO THURSDAY AFTERNOON.
THE PROGRESSIVE ACTIVE FLOW PATTERN IS FORECAST TO CONTINUE INTO
THE WEEKEND...WITH STRONG HIGH PRESSURE ON FRIDAY GIVING WAY TO
PRECIPITATION CHANCES THIS WEEKEND. ANOTHER CLOSED LOW OVER THE
FAR SOUTHWESTERN U.S. IS FORECAST TO MOVE GRADUALLY EASTWARD AND
LOOKS TO BE ABLE TO TAP INTO GULF AND EASTERN PACIFIC MOISTURE.
WITH A CUT-OFF FEATURE THIS COULD END UP SLOWING AND CERTAINLY
CHANGING IN EVOLUTION. GUIDANCE DISAGREES HOW ANY NORTHERN STREAM
DISTURBANCE MAY AID TO PULL SOME OF THIS MOISTURE OVER OUR AREA.
AT THIS TIME THIS LOOKS TO BE A POSSIBLY LONG DURATION BUT LIGHT
INTENSITY QPF EVENT AT THIS LATITUDE. GIVEN THE FEATURES AT PLAY
AND CURRENT PATTERN WE ARE IN...ITS JUST WAY TOO EARLY AS
POTENTIAL COULD GO EITHER WAY FROM THAT SOLUTION. CONFIDENCE IS A
LITTLE HIGHER IN THAT IT WOULD PROBABLY BE A MAINLY SNOW EVENT IF
IT WERE TO OCCUR. GUIDANCE IS IN BETTER AGREEMENT THAN 24 HOURS
AGO WITH A CANADIAN/MODIFIED ARCTIC AIR MASS BEING TAPPED IN THE
WAKE OF THIS SYSTEM WITH POSSIBLY SINGLE DIGIT NIGHTTIME
TEMPERATURES DEPENDING ON IF ANY FRESH SNOW COVER CAN OCCUR.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* MVFR CIGS CLEARING THE TERMINALS EARLY THIS AFTERNOON...BUT
LIKELY REMAIN NEARBY THIS EVENING AND TONIGHT.
BMD
//DISCUSSION...UPDATED 18Z...
BROAD MVFR STRATUS DECK BLANKETS THE REGION TODAY BUT HAS BEEN
STEADILY ERODING FROM THE NORTHEAST...WITH CLEARING SKIES MAKING
PROGRESS DOWN LAKE MICHIGAN THIS MORNING AND INTO THE CHICAGO AREA
EARLY THIS AFTERNOON. CLOUD BEARING FLOW OUT OF THE NORTHEAST THIS
MORNING WILL BACK TO THE NORTH THIS AFTERNOON AND EVENING SO EXPECT
THE PROGRESS OF THE CLEARING TO SLOW SOME...AND MAY EVEN REVERSE
TONIGHT AS A SURFACE RIDGE BUILDS ACROSS INDIANA WITH FLOW BECOMING
MORE SOUTHERLY. SURFACE WINDS WILL GENERALLY DECREASE FROM MID
AFTERNOON ON AS THE SURFACE HIGH NEARS...AND GO LIGHT AND
VARIABLE FOR A PERIOD THIS EVENING AND OVERNIGHT...BEFORE TURNING
SOUTH/SOUTH-SOUTHEAST TOMORROW. GUSTY WINDS PUSHING 20 KT ARE
EXPECTED TOMORROW AFTERNOON.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN PERIODS OF VFR THIS AFTERNOON...LOW-MEDIUM
CONFIDENCE IN CIG TRENDS OVERNIGHT.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...CHANCE OF RAIN/DRIZZLE. MVFR/IFR POSSIBLE.
THURSDAY...CHANCE OF RAIN/SNOW. MVFR LIKELY/IFR POSSIBLE.
FRIDAY AND SATURDAY...PRIMARILY VFR. CHANCE OF SNOW SATURDAY
NIGHT.
SUNDAY...CHANCE OF LIGHT SNOW. IFR POSSIBLE.
MONDAY...MVFR CIGS POSSIBLE.
RATZER
&&
.MARINE...
213 AM CST
MARINE CONCERNS ON LAKE MICHIGAN ARE A PERIOD OF STRONG SOUTH WINDS
WEDNESDAY AFTERNOON AND NIGHT...THEN A SHIFT TO STRONG NORTH TO
NORTHWEST WINDS THURSDAY AFTERNOON INTO EARLY FRIDAY...WITH THE
POTENTIAL FOR A PERIOD OF NORTHWEST GALES ESPECIALLY THURSDAY
AFTERNOON AND THURSDAY EVENING.
IN THE NEAR TERM...RELATIVELY QUIET WEATHER ACROSS THE LAKE EARLY
THIS MORNING AS A WEAKENING SURFACE TROUGH OVER ILLINOIS AND THE
LOWER OHIO VALLEY CONTINUES TO MOVE OFF TO THE SOUTHEAST...ALLOWING
WEAK HIGH PRESSURE TO SETTLE ACROSS THE AREA FROM THE NORTH TODAY.
LOOKING TO THE WEST...AN AREA OF LOW PRESSURE DEVELOPING IN THE LEE
OF THE CANADIAN ROCKIES WILL SLIDE SOUTHEAST INTO THE PLAINS
THROUGH TONIGHT...THEN WILL MOVE SLOWLY EAST TOWARD LAKE MICHIGAN
WEDNESDAY AND WEDNESDAY NIGHT. IN RESPONSE TO PRESSURE FALLS AHEAD
OF THE LOW...THE GRADIENT WILL TIGHTEN ACROSS LAKE MICHIGAN
WEDNESDAY WITH SOUTH WINDS RAMPING UP INTO THE 30 KT RANGE BY LATE
AFTERNOON AND EVENING. WINDS WILL DIMINISH BRIEFLY EARLY THURSDAY
MORNING AS THE LOW PRESSURE CENTER AND COLD FRONTAL TROUGH CROSS THE
LAKE...BEFORE WINDS SHIFT TO THE NORTH-NORTHWEST AND INCREASE
QUICKLY BACK INTO THE 30-35 KT RANGE THURSDAY AFTERNOON. FORECAST
SOUNDINGS INDICATE THE POTENTIAL FOR GALES THURSDAY AFTERNOON AND
EVENING IN THE STRONG PRESSURE RISES AND COLD ADVECTION BEHIND THE
DEPARTING LOW AND COLD FRONT. THESE STRONG WINDS WILL CONTINUE INTO
EARLY FRIDAY...BEFORE DIMINISHING AS A BROAD AREA OF HIGH PRESSURE
SPREADS INTO THE AREA BY FRIDAY EVENING. THE HIGH WILL SLOWLY MOVE
OFF TO THE EAST ON SATURDAY...WITH A WEAK LOW EXPECTED TO PASS
ACROSS THE NORTHERN LAKES SATURDAY NIGHT AND TRAIL A COLD FRONT
ACROSS LAKE MICHIGAN THROUGH SUNDAY.
FOR THE ILLINOIS AND NORTHWEST INDIANA NEARSHORE WATERS SMALL CRAFT
ADVISORY CONDITIONS LOOK TO DEVELOP WEDNESDAY AFTERNOON AND CONTINUE
THROUGH THURSDAY MORNING...WITH A BRIEF BREAK BEFORE HIGH WIND/WAVE
CONDITIONS DEVELOP AGAIN BY EARLY THURSDAY AFTERNOON. HIGH WAVES
WOULD LIKELY LINGER THROUGH MUCH OF FRIDAY...ESPECIALLY ALONG THE
INDIANA SHORE EAST OF GARY.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1146 AM CST TUE JAN 27 2015
.SHORT TERM...
330 AM CST
THROUGH WEDNESDAY...
INFRARED AND WATER VAPOR SATELLITE LOOPS EARLY THIS MORNING HAVE
SHOWN THE LAST IN A SERIES OF SHEARED VORTICITY MAXIMA TO HAVE MOVED
SOUTHEAST OF THE AREA. LIGHT SNOW ASSOCIATED WITH THESE HAS MAINLY
ENDED. LOW-LEVEL WINDS HAVE ALSO SHIFTED MORE NORTHERLY AS A
SURFACE INDUCED TROUGH AXIS PULLS AWAY. THIS HAS ENDED THE LOW-
LEVEL ISENTROPIC ASCENT AND OMEGA WHICH HELPED TO INDUCE MUCH OF
THE FREEZING DRIZZLE LAST NIGHT. SO WITH THAT HAVE CANCELLED THE
ADVISORY AS THE WIDESPREAD THREAT HAS ENDED GOING INTO THE RUSH
HOUR. ONE HOPEFULLY ONLY SMALL FLY IN THE OINTMENT TO THIS IS THE
CHANCE FOR FREEZING DRIZZLE LINGERING IN MAINLY LAKE AND COOK
COUNTIES...INCLUDING CHICAGO...AS WINDS TURN OFF THE LAKE EARLY
THIS MORNING STEERING IN SOME MARGINAL LAKE-INDUCED INSTABILITY.
THE MKX RADAR IS INDICATING LIGHT ECHOES MOVING WESTWARD THAT
DUAL-POL SUGGESTS IS FREEZING DRIZZLE. RAP PROFILES ARE ONLY
SATURATED ABOUT AS COOL AS -8C ADDING SUPPORT TO THAT. WITH NOT
EXPECTING A SITUATION SUCH AS LAST EVENING GIVEN THE TREATMENT ON
ROADS AND THE DIFFERENT MORE MESOSCALE/LOCALIZED INDUCED
LIFT...FEEL BETTER GOING WITH AN SPS IF NEEDED. EXPECT THE CHANCES
TO END BY 10 AM OR SO AS DRIER AIR CONTINUES TO ADVECT WESTWARD
OVER THE LAKE SEEN BY DEW POINTS NEAR 10F ON THE MICHIGAN SHORE
ALONG WITH AN EAST WIND.
CLOUDS SHOULD BE SLOW TO CLEAR TODAY GIVEN THE CURRENT EXPANSIVENESS
TO THE NORTH AND THE CYCLONIC FLOW CONTINUING THROUGH THIS
MORNING...AS WELL AS AFOREMENTIONED LAKE-ORIENTED FLOW INTO
NORTHEAST ILLINOIS. MESOSCALE MODEL MOISTURE/CONDENSATE FIELDS
INDICATE CLOUDS LINGERING THE LONGEST ACROSS THE ILLINOIS PART OF
THE CWA WITH INDIANA EXPERIENCING NORTHEASTERLY DRY ADVECTION.
HAVE HIGHS ONLY A FEW DEGREES WARMER THAN CURRENT EARLY MORNING
VALUES GIVEN THIS THOUGHT PROCESS. CONFIDENCE IS LOW ON WHETHER
CLEARING OCCURS AREAWIDE LATE THIS AFTERNOON AND EVENING AS
GUIDANCE WOULD SUGGEST...PLUS THERE WILL LIKELY BE CIRRUS
SPREADING IN TOO. THIS INTRODUCES BUST POTENTIAL IN LOW
TEMPERATURES OVER NORTH CENTRAL ILLINOIS WHERE LOW TEENS TO MID
20S COULD OCCUR DEPENDING ON CLOUDS. FEEL MORE CONFIDENT NORTHWEST
INDIANA WILL BE MOSTLY CLEAR AND TOUCH SOME OF THOSE LOWER TO MID
TEENS.
DURING THE DAY WEDNESDAY...A THERMAL RIDGE BUILDS INTO THE AREA AND
EXPECTING AT LEAST SOME SUNSHINE AS SOUTHWESTERLY LOW-LEVEL FLOW
WILL BE ENOUGH TO ADVECT OUT ANY RESIDUAL LOW CLOUDS. THE WARMEST
PART OF THE THERMAL RIDGE REACHES US MORE SO WEDNESDAY NIGHT AND
CLIMATOLOGY FOR FORECAST 925MB TEMPERATURES WOULD KEEP
SURFACE READINGS IN THE 30S FOR MOST OF THE CWA ESPECIALLY WITH
SOME SNOW COVER ALBEIT MINIMAL.
MTF
&&
.LONG TERM...
330 AM CST
WEDNESDAY NIGHT THROUGH MONDAY...
THE NEXT CHANCE FOR PRECIPITATION IS WEDNESDAY NIGHT AND
THURSDAY...AND CONFIDENCE HAS FURTHER INCREASED THAT THIS WILL BE A
LIGHT PRECIPITATION EVENT...AS WELL AS ONE WITH ONLY LIQUID
WEDNESDAY NIGHT IF PRECIPITATION DEVELOPS OVER OUR AREA. A CLOSED
UPPER LOW NEAR LOS ANGELES EARLY THIS MORNING IS STILL FORECAST TO
GET CAUGHT IN THE WESTERLIES AND DAMPEN THE STRONG UPPER RIDGE IN
PLACE OVER THE ROCKIES. A GRADUAL PHASING WITH A NORTHERN STREAM
PROGRESSIVE WAVE IS EXPECTED WEDNESDAY NIGHT THROUGH THURSDAY
OVER THE GREAT LAKES REGION. WHILE THE 27.00 GFS IS MORE
AGGRESSIVE WITH THIS PHASING THAN OTHER 27.00 GUIDANCE...IT ONLY
BRINGS A LITTLE MORE OOMPH FOR PRECIP HERE. THE THERMAL RIDGE
MENTIONED IN THE SHORT TERM SECTION FOR WEDNESDAY IS 2C-6C AT
850-925MB AND SURFACE TEMPERATURES ARE NOT LIKELY TO DROP GIVEN
THE SOUTHERN FLOW AND INCREASING CLOUDS...SO HAVE CHANCES OF RAIN
AND DRIZZLE WEDNESDAY NIGHT AS MOISTURE TRANSPORT DEVELOPS. ON
THURSDAY...TRANSITION TO A LIGHT RAIN AND SNOW MIX AND AT THIS
POINT WPC AND OURSELVES REALLY HAVE NO ACCUMULATIONS FORECAST.
HAVE STILL TRIED TO TAKE INTO ACCOUNT SOME POSSIBLE SLOWING IN THE
FORECAST GIVEN THE CURRENT SIGNIFICANT CLOSED SYSTEM OFF THE
NORTHEAST U.S...AND KEPT PRECIP CHANCES INTO THURSDAY AFTERNOON.
THE PROGRESSIVE ACTIVE FLOW PATTERN IS FORECAST TO CONTINUE INTO
THE WEEKEND...WITH STRONG HIGH PRESSURE ON FRIDAY GIVING WAY TO
PRECIPITATION CHANCES THIS WEEKEND. ANOTHER CLOSED LOW OVER THE
FAR SOUTHWESTERN U.S. IS FORECAST TO MOVE GRADUALLY EASTWARD AND
LOOKS TO BE ABLE TO TAP INTO GULF AND EASTERN PACIFIC MOISTURE.
WITH A CUT-OFF FEATURE THIS COULD END UP SLOWING AND CERTAINLY
CHANGING IN EVOLUTION. GUIDANCE DISAGREES HOW ANY NORTHERN STREAM
DISTURBANCE MAY AID TO PULL SOME OF THIS MOISTURE OVER OUR AREA.
AT THIS TIME THIS LOOKS TO BE A POSSIBLY LONG DURATION BUT LIGHT
INTENSITY QPF EVENT AT THIS LATITUDE. GIVEN THE FEATURES AT PLAY
AND CURRENT PATTERN WE ARE IN...ITS JUST WAY TOO EARLY AS
POTENTIAL COULD GO EITHER WAY FROM THAT SOLUTION. CONFIDENCE IS A
LITTLE HIGHER IN THAT IT WOULD PROBABLY BE A MAINLY SNOW EVENT IF
IT WERE TO OCCUR. GUIDANCE IS IN BETTER AGREEMENT THAN 24 HOURS
AGO WITH A CANADIAN/MODIFIED ARCTIC AIR MASS BEING TAPPED IN THE
WAKE OF THIS SYSTEM WITH POSSIBLY SINGLE DIGIT NIGHTTIME
TEMPERATURES DEPENDING ON IF ANY FRESH SNOW COVER CAN OCCUR.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* MVFR CIGS CLEARING THE TERMINALS EARLY THIS AFTERNOON...BUT
LIKELY REMAIN NEARBY THIS EVENING AND TONIGHT.
BMD
//DISCUSSION...UPDATED 18Z...
BROAD MVFR STRATUS DECK BLANKETS THE REGION TODAY BUT HAS BEEN
STEADILY ERODING FROM THE NORTHEAST...WITH CLEARING SKIES MAKING
PROGRESS DOWN LAKE MICHIGAN THIS MORNING AND INTO THE CHICAGO AREA
EARLY THIS AFTERNOON. CLOUD BEARING FLOW OUT OF THE NORTHEAST THIS
MORNING WILL BACK TO THE NORTH THIS AFTERNOON AND EVENING SO EXPECT
THE PROGRESS OF THE CLEARING TO SLOW SOME...AND MAY EVEN REVERSE
TONIGHT AS A SURFACE RIDGE BUILDS ACROSS INDIANA WITH FLOW BECOMING
MORE SOUTHERLY. SURFACE WINDS WILL GENERALLY DECREASE FROM MID
AFTERNOON ON AS THE SURFACE HIGH NEARS...AND GO LIGHT AND
VARIABLE FOR A PERIOD THIS EVENING AND OVERNIGHT...BEFORE TURNING
SOUTH/SOUTH-SOUTHEAST TOMORROW. GUSTY WINDS PUSHING 20 KT ARE
EXPECTED TOMORROW AFTERNOON.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM-HIGH CONFIDENCE IN PERIODS OF VFR THIS AFTERNOON...LOW-
MEDIUM CONFIDENCE IN CIG TRENDS OVERNIGHT.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...CHANCE OF RAIN/DRIZZLE. MVFR/IFR POSSIBLE.
THURSDAY...CHANCE OF RAIN/SNOW. MVFR LIKELY/IFR POSSIBLE.
FRIDAY AND SATURDAY...PRIMARILY VFR. CHANCE OF SNOW SATURDAY
NIGHT.
SUNDAY...CHANCE OF LIGHT SNOW. IFR POSSIBLE.
MONDAY...MVFR CIGS POSSIBLE.
RATZER
&&
.MARINE...
213 AM CST
MARINE CONCERNS ON LAKE MICHIGAN ARE A PERIOD OF STRONG SOUTH WINDS
WEDNESDAY AFTERNOON AND NIGHT...THEN A SHIFT TO STRONG NORTH TO
NORTHWEST WINDS THURSDAY AFTERNOON INTO EARLY FRIDAY...WITH THE
POTENTIAL FOR A PERIOD OF NORTHWEST GALES ESPECIALLY THURSDAY
AFTERNOON AND THURSDAY EVENING.
IN THE NEAR TERM...RELATIVELY QUIET WEATHER ACROSS THE LAKE EARLY
THIS MORNING AS A WEAKENING SURFACE TROUGH OVER ILLINOIS AND THE
LOWER OHIO VALLEY CONTINUES TO MOVE OFF TO THE SOUTHEAST...ALLOWING
WEAK HIGH PRESSURE TO SETTLE ACROSS THE AREA FROM THE NORTH TODAY.
LOOKING TO THE WEST...AN AREA OF LOW PRESSURE DEVELOPING IN THE LEE
OF THE CANADIAN ROCKIES WILL SLIDE SOUTHEAST INTO THE PLAINS
THROUGH TONIGHT...THEN WILL MOVE SLOWLY EAST TOWARD LAKE MICHIGAN
WEDNESDAY AND WEDNESDAY NIGHT. IN RESPONSE TO PRESSURE FALLS AHEAD
OF THE LOW...THE GRADIENT WILL TIGHTEN ACROSS LAKE MICHIGAN
WEDNESDAY WITH SOUTH WINDS RAMPING UP INTO THE 30 KT RANGE BY LATE
AFTERNOON AND EVENING. WINDS WILL DIMINISH BRIEFLY EARLY THURSDAY
MORNING AS THE LOW PRESSURE CENTER AND COLD FRONTAL TROUGH CROSS THE
LAKE...BEFORE WINDS SHIFT TO THE NORTH-NORTHWEST AND INCREASE
QUICKLY BACK INTO THE 30-35 KT RANGE THURSDAY AFTERNOON. FORECAST
SOUNDINGS INDICATE THE POTENTIAL FOR GALES THURSDAY AFTERNOON AND
EVENING IN THE STRONG PRESSURE RISES AND COLD ADVECTION BEHIND THE
DEPARTING LOW AND COLD FRONT. THESE STRONG WINDS WILL CONTINUE INTO
EARLY FRIDAY...BEFORE DIMINISHING AS A BROAD AREA OF HIGH PRESSURE
SPREADS INTO THE AREA BY FRIDAY EVENING. THE HIGH WILL SLOWLY MOVE
OFF TO THE EAST ON SATURDAY...WITH A WEAK LOW EXPECTED TO PASS
ACROSS THE NORTHERN LAKES SATURDAY NIGHT AND TRAIL A COLD FRONT
ACROSS LAKE MICHIGAN THROUGH SUNDAY.
FOR THE ILLINOIS AND NORTHWEST INDIANA NEARSHORE WATERS SMALL CRAFT
ADVISORY CONDITIONS LOOK TO DEVELOP WEDNESDAY AFTERNOON AND CONTINUE
THROUGH THURSDAY MORNING...WITH A BRIEF BREAK BEFORE HIGH WIND/WAVE
CONDITIONS DEVELOP AGAIN BY EARLY THURSDAY AFTERNOON. HIGH WAVES
WOULD LIKELY LINGER THROUGH MUCH OF FRIDAY...ESPECIALLY ALONG THE
INDIANA SHORE EAST OF GARY.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1016 AM CST TUE JAN 27 2015
.SHORT TERM...
330 AM CST
THROUGH WEDNESDAY...
INFRARED AND WATER VAPOR SATELLITE LOOPS EARLY THIS MORNING HAVE
SHOWN THE LAST IN A SERIES OF SHEARED VORTICITY MAXIMA TO HAVE MOVED
SOUTHEAST OF THE AREA. LIGHT SNOW ASSOCIATED WITH THESE HAS MAINLY
ENDED. LOW-LEVEL WINDS HAVE ALSO SHIFTED MORE NORTHERLY AS A
SURFACE INDUCED TROUGH AXIS PULLS AWAY. THIS HAS ENDED THE LOW-
LEVEL ISENTROPIC ASCENT AND OMEGA WHICH HELPED TO INDUCE MUCH OF
THE FREEZING DRIZZLE LAST NIGHT. SO WITH THAT HAVE CANCELLED THE
ADVISORY AS THE WIDESPREAD THREAT HAS ENDED GOING INTO THE RUSH
HOUR. ONE HOPEFULLY ONLY SMALL FLY IN THE OINTMENT TO THIS IS THE
CHANCE FOR FREEZING DRIZZLE LINGERING IN MAINLY LAKE AND COOK
COUNTIES...INCLUDING CHICAGO...AS WINDS TURN OFF THE LAKE EARLY
THIS MORNING STEERING IN SOME MARGINAL LAKE-INDUCED INSTABILITY.
THE MKX RADAR IS INDICATING LIGHT ECHOES MOVING WESTWARD THAT
DUAL-POL SUGGESTS IS FREEZING DRIZZLE. RAP PROFILES ARE ONLY
SATURATED ABOUT AS COOL AS -8C ADDING SUPPORT TO THAT. WITH NOT
EXPECTING A SITUATION SUCH AS LAST EVENING GIVEN THE TREATMENT ON
ROADS AND THE DIFFERENT MORE MESOSCALE/LOCALIZED INDUCED
LIFT...FEEL BETTER GOING WITH AN SPS IF NEEDED. EXPECT THE CHANCES
TO END BY 10 AM OR SO AS DRIER AIR CONTINUES TO ADVECT WESTWARD
OVER THE LAKE SEEN BY DEW POINTS NEAR 10F ON THE MICHIGAN SHORE
ALONG WITH AN EAST WIND.
CLOUDS SHOULD BE SLOW TO CLEAR TODAY GIVEN THE CURRENT EXPANSIVENESS
TO THE NORTH AND THE CYCLONIC FLOW CONTINUING THROUGH THIS
MORNING...AS WELL AS AFOREMENTIONED LAKE-ORIENTED FLOW INTO
NORTHEAST ILLINOIS. MESOSCALE MODEL MOISTURE/CONDENSATE FIELDS
INDICATE CLOUDS LINGERING THE LONGEST ACROSS THE ILLINOIS PART OF
THE CWA WITH INDIANA EXPERIENCING NORTHEASTERLY DRY ADVECTION.
HAVE HIGHS ONLY A FEW DEGREES WARMER THAN CURRENT EARLY MORNING
VALUES GIVEN THIS THOUGHT PROCESS. CONFIDENCE IS LOW ON WHETHER
CLEARING OCCURS AREAWIDE LATE THIS AFTERNOON AND EVENING AS
GUIDANCE WOULD SUGGEST...PLUS THERE WILL LIKELY BE CIRRUS
SPREADING IN TOO. THIS INTRODUCES BUST POTENTIAL IN LOW
TEMPERATURES OVER NORTH CENTRAL ILLINOIS WHERE LOW TEENS TO MID
20S COULD OCCUR DEPENDING ON CLOUDS. FEEL MORE CONFIDENT NORTHWEST
INDIANA WILL BE MOSTLY CLEAR AND TOUCH SOME OF THOSE LOWER TO MID
TEENS.
DURING THE DAY WEDNESDAY...A THERMAL RIDGE BUILDS INTO THE AREA AND
EXPECTING AT LEAST SOME SUNSHINE AS SOUTHWESTERLY LOW-LEVEL FLOW
WILL BE ENOUGH TO ADVECT OUT ANY RESIDUAL LOW CLOUDS. THE WARMEST
PART OF THE THERMAL RIDGE REACHES US MORE SO WEDNESDAY NIGHT AND
CLIMATOLOGY FOR FORECAST 925MB TEMPERATURES WOULD KEEP
SURFACE READINGS IN THE 30S FOR MOST OF THE CWA ESPECIALLY WITH
SOME SNOW COVER ALBEIT MINIMAL.
MTF
&&
.LONG TERM...
330 AM CST
WEDNESDAY NIGHT THROUGH MONDAY...
THE NEXT CHANCE FOR PRECIPITATION IS WEDNESDAY NIGHT AND
THURSDAY...AND CONFIDENCE HAS FURTHER INCREASED THAT THIS WILL BE A
LIGHT PRECIPITATION EVENT...AS WELL AS ONE WITH ONLY LIQUID
WEDNESDAY NIGHT IF PRECIPITATION DEVELOPS OVER OUR AREA. A CLOSED
UPPER LOW NEAR LOS ANGELES EARLY THIS MORNING IS STILL FORECAST TO
GET CAUGHT IN THE WESTERLIES AND DAMPEN THE STRONG UPPER RIDGE IN
PLACE OVER THE ROCKIES. A GRADUAL PHASING WITH A NORTHERN STREAM
PROGRESSIVE WAVE IS EXPECTED WEDNESDAY NIGHT THROUGH THURSDAY
OVER THE GREAT LAKES REGION. WHILE THE 27.00 GFS IS MORE
AGGRESSIVE WITH THIS PHASING THAN OTHER 27.00 GUIDANCE...IT ONLY
BRINGS A LITTLE MORE OOMPH FOR PRECIP HERE. THE THERMAL RIDGE
MENTIONED IN THE SHORT TERM SECTION FOR WEDNESDAY IS 2C-6C AT
850-925MB AND SURFACE TEMPERATURES ARE NOT LIKELY TO DROP GIVEN
THE SOUTHERN FLOW AND INCREASING CLOUDS...SO HAVE CHANCES OF RAIN
AND DRIZZLE WEDNESDAY NIGHT AS MOISTURE TRANSPORT DEVELOPS. ON
THURSDAY...TRANSITION TO A LIGHT RAIN AND SNOW MIX AND AT THIS
POINT WPC AND OURSELVES REALLY HAVE NO ACCUMULATIONS FORECAST.
HAVE STILL TRIED TO TAKE INTO ACCOUNT SOME POSSIBLE SLOWING IN THE
FORECAST GIVEN THE CURRENT SIGNIFICANT CLOSED SYSTEM OFF THE
NORTHEAST U.S...AND KEPT PRECIP CHANCES INTO THURSDAY AFTERNOON.
THE PROGRESSIVE ACTIVE FLOW PATTERN IS FORECAST TO CONTINUE INTO
THE WEEKEND...WITH STRONG HIGH PRESSURE ON FRIDAY GIVING WAY TO
PRECIPITATION CHANCES THIS WEEKEND. ANOTHER CLOSED LOW OVER THE
FAR SOUTHWESTERN U.S. IS FORECAST TO MOVE GRADUALLY EASTWARD AND
LOOKS TO BE ABLE TO TAP INTO GULF AND EASTERN PACIFIC MOISTURE.
WITH A CUT-OFF FEATURE THIS COULD END UP SLOWING AND CERTAINLY
CHANGING IN EVOLUTION. GUIDANCE DISAGREES HOW ANY NORTHERN STREAM
DISTURBANCE MAY AID TO PULL SOME OF THIS MOISTURE OVER OUR AREA.
AT THIS TIME THIS LOOKS TO BE A POSSIBLY LONG DURATION BUT LIGHT
INTENSITY QPF EVENT AT THIS LATITUDE. GIVEN THE FEATURES AT PLAY
AND CURRENT PATTERN WE ARE IN...ITS JUST WAY TOO EARLY AS
POTENTIAL COULD GO EITHER WAY FROM THAT SOLUTION. CONFIDENCE IS A
LITTLE HIGHER IN THAT IT WOULD PROBABLY BE A MAINLY SNOW EVENT IF
IT WERE TO OCCUR. GUIDANCE IS IN BETTER AGREEMENT THAN 24 HOURS
AGO WITH A CANADIAN/MODIFIED ARCTIC AIR MASS BEING TAPPED IN THE
WAKE OF THIS SYSTEM WITH POSSIBLY SINGLE DIGIT NIGHTTIME
TEMPERATURES DEPENDING ON IF ANY FRESH SNOW COVER CAN OCCUR.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* CIGS SCATTERING TO VFR LATER THIS MORNING OR EARLY AFTERNOON.
* NORTHEAST WINDS AROUND 10 KT TODAY...BECOMING LIGHT/VARIABLE
AGAIN THIS EVENING/OVERNIGHT.
RATZER/DEUBELBEISS
//DISCUSSION...UPDATED 12Z...
WEAK LOW PRESSURE SYSTEM CONTINUES TO PULL AWAY TO THE SOUTHEAST
THIS MORNING...WITH A LINGERING SURFACE TROUGH REMAINING THE FOCUS
FOR AN AREA OF LOW CLOUDS...MVFR FOG AND SOME PATCHY LIGHT
FREEZING DRIZZLE. MID-LEVEL DISTURBANCE OVERHEAD AND WILL MOVE OFF
TO THE SOUTHEAST THIS MORNING...WHICH ALONG WITH DRIER NORTHEAST
WINDS DEVELOPING ABOVE THE SURFACE SHOULD LEAD TO DIMINISHING
POTENTIAL FOR -FZDZ BY MID-MORNING. DRIER AIR FROM THE NORTHEAST
SHOULD ALSO WORK TO RAISE CIGS AND IMPROVE VIS THROUGH THE MORNING
AND EARLY AFTERNOON HOURS AS WELL. WEAK HIGH PRESSURE WILL SPREAD
ACROSS THE AREA FROM THE NORTHWEST THIS EVENING...WITH VFR
CONDITIONS...THOUGH RFD/DPA COULD SEE SOME SHALLOW FOG DEVELOP
OVERNIGHT.
NORTH-NORTHEAST WINDS EARLY THIS MORNING WILL BECOME MORE SOLIDLY
NORTHEAST DURING THE MORNING...AROUND 10 KT. WINDS WILL DIMINISH
TOWARD EVENING AS GRADIENT WEAKENS WITH APPROACH OF THE HIGH...
WITH LIGHT/VARIABLE WINDS THIS EVENING AND OVERNIGHT. WITH THE
HIGH SHIFTING SOUTHEAST OF THE AREA EARLY WEDNESDAY...SOUTH WINDS
WILL DEVELOP.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM IN TIMING IMPROVEMENT FROM MVFR TO VFR.
* HIGH IN WIND TRENDS.
RATZER/DEUBELBEISS
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...CHANCE OF RAIN/DRIZZLE. MVFR/IFR POSSIBLE.
THURSDAY...CHANCE OF RAIN/SNOW. MVFR LIKELY/IFR POSSIBLE.
FRIDAY AND SATURDAY...PRIMARILY VFR. CHANCE OF SNOW SATURDAY
NIGHT.
SUNDAY...CHANCE OF LIGHT SNOW. IFR POSSIBLE.
MONDAY...MVFR CIGS POSSIBLE.
RATZER
&&
.MARINE...
213 AM CST
MARINE CONCERNS ON LAKE MICHIGAN ARE A PERIOD OF STRONG SOUTH WINDS
WEDNESDAY AFTERNOON AND NIGHT...THEN A SHIFT TO STRONG NORTH TO
NORTHWEST WINDS THURSDAY AFTERNOON INTO EARLY FRIDAY...WITH THE
POTENTIAL FOR A PERIOD OF NORTHWEST GALES ESPECIALLY THURSDAY
AFTERNOON AND THURSDAY EVENING.
IN THE NEAR TERM...RELATIVELY QUIET WEATHER ACROSS THE LAKE EARLY
THIS MORNING AS A WEAKENING SURFACE TROUGH OVER ILLINOIS AND THE
LOWER OHIO VALLEY CONTINUES TO MOVE OFF TO THE SOUTHEAST...ALLOWING
WEAK HIGH PRESSURE TO SETTLE ACROSS THE AREA FROM THE NORTH TODAY.
LOOKING TO THE WEST...AN AREA OF LOW PRESSURE DEVELOPING IN THE LEE
OF THE CANADIAN ROCKIES WILL SLIDE SOUTHEAST INTO THE PLAINS
THROUGH TONIGHT...THEN WILL MOVE SLOWLY EAST TOWARD LAKE MICHIGAN
WEDNESDAY AND WEDNESDAY NIGHT. IN RESPONSE TO PRESSURE FALLS AHEAD
OF THE LOW...THE GRADIENT WILL TIGHTEN ACROSS LAKE MICHIGAN
WEDNESDAY WITH SOUTH WINDS RAMPING UP INTO THE 30 KT RANGE BY LATE
AFTERNOON AND EVENING. WINDS WILL DIMINISH BRIEFLY EARLY THURSDAY
MORNING AS THE LOW PRESSURE CENTER AND COLD FRONTAL TROUGH CROSS THE
LAKE...BEFORE WINDS SHIFT TO THE NORTH-NORTHWEST AND INCREASE
QUICKLY BACK INTO THE 30-35 KT RANGE THURSDAY AFTERNOON. FORECAST
SOUNDINGS INDICATE THE POTENTIAL FOR GALES THURSDAY AFTERNOON AND
EVENING IN THE STRONG PRESSURE RISES AND COLD ADVECTION BEHIND THE
DEPARTING LOW AND COLD FRONT. THESE STRONG WINDS WILL CONTINUE INTO
EARLY FRIDAY...BEFORE DIMINISHING AS A BROAD AREA OF HIGH PRESSURE
SPREADS INTO THE AREA BY FRIDAY EVENING. THE HIGH WILL SLOWLY MOVE
OFF TO THE EAST ON SATURDAY...WITH A WEAK LOW EXPECTED TO PASS
ACROSS THE NORTHERN LAKES SATURDAY NIGHT AND TRAIL A COLD FRONT
ACROSS LAKE MICHIGAN THROUGH SUNDAY.
FOR THE ILLINOIS AND NORTHWEST INDIANA NEARSHORE WATERS SMALL CRAFT
ADVISORY CONDITIONS LOOK TO DEVELOP WEDNESDAY AFTERNOON AND CONTINUE
THROUGH THURSDAY MORNING...WITH A BRIEF BREAK BEFORE HIGH WIND/WAVE
CONDITIONS DEVELOP AGAIN BY EARLY THURSDAY AFTERNOON. HIGH WAVES
WOULD LIKELY LINGER THROUGH MUCH OF FRIDAY...ESPECIALLY ALONG THE
INDIANA SHORE EAST OF GARY.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
806 AM CST TUE JAN 27 2015
.SHORT TERM...
330 AM CST
THROUGH WEDNESDAY...
INFRARED AND WATER VAPOR SATELLITE LOOPS EARLY THIS MORNING HAVE
SHOWN THE LAST IN A SERIES OF SHEARED VORTICITY MAXIMA TO HAVE MOVED
SOUTHEAST OF THE AREA. LIGHT SNOW ASSOCIATED WITH THESE HAS MAINLY
ENDED. LOW-LEVEL WINDS HAVE ALSO SHIFTED MORE NORTHERLY AS A
SURFACE INDUCED TROUGH AXIS PULLS AWAY. THIS HAS ENDED THE LOW-
LEVEL ISENTROPIC ASCENT AND OMEGA WHICH HELPED TO INDUCE MUCH OF
THE FREEZING DRIZZLE LAST NIGHT. SO WITH THAT HAVE CANCELLED THE
ADVISORY AS THE WIDESPREAD THREAT HAS ENDED GOING INTO THE RUSH
HOUR. ONE HOPEFULLY ONLY SMALL FLY IN THE OINTMENT TO THIS IS THE
CHANCE FOR FREEZING DRIZZLE LINGERING IN MAINLY LAKE AND COOK
COUNTIES...INCLUDING CHICAGO...AS WINDS TURN OFF THE LAKE EARLY
THIS MORNING STEERING IN SOME MARGINAL LAKE-INDUCED INSTABILITY.
THE MKX RADAR IS INDICATING LIGHT ECHOES MOVING WESTWARD THAT
DUAL-POL SUGGESTS IS FREEZING DRIZZLE. RAP PROFILES ARE ONLY
SATURATED ABOUT AS COOL AS -8C ADDING SUPPORT TO THAT. WITH NOT
EXPECTING A SITUATION SUCH AS LAST EVENING GIVEN THE TREATMENT ON
ROADS AND THE DIFFERENT MORE MESOSCALE/LOCALIZED INDUCED
LIFT...FEEL BETTER GOING WITH AN SPS IF NEEDED. EXPECT THE CHANCES
TO END BY 10 AM OR SO AS DRIER AIR CONTINUES TO ADVECT WESTWARD
OVER THE LAKE SEEN BY DEW POINTS NEAR 10F ON THE MICHIGAN SHORE
ALONG WITH AN EAST WIND.
CLOUDS SHOULD BE SLOW TO CLEAR TODAY GIVEN THE CURRENT EXPANSIVENESS
TO THE NORTH AND THE CYCLONIC FLOW CONTINUING THROUGH THIS
MORNING...AS WELL AS AFOREMENTIONED LAKE-ORIENTED FLOW INTO
NORTHEAST ILLINOIS. MESOSCALE MODEL MOISTURE/CONDENSATE FIELDS
INDICATE CLOUDS LINGERING THE LONGEST ACROSS THE ILLINOIS PART OF
THE CWA WITH INDIANA EXPERIENCING NORTHEASTERLY DRY ADVECTION.
HAVE HIGHS ONLY A FEW DEGREES WARMER THAN CURRENT EARLY MORNING
VALUES GIVEN THIS THOUGHT PROCESS. CONFIDENCE IS LOW ON WHETHER
CLEARING OCCURS AREAWIDE LATE THIS AFTERNOON AND EVENING AS
GUIDANCE WOULD SUGGEST...PLUS THERE WILL LIKELY BE CIRRUS
SPREADING IN TOO. THIS INTRODUCES BUST POTENTIAL IN LOW
TEMPERATURES OVER NORTH CENTRAL ILLINOIS WHERE LOW TEENS TO MID
20S COULD OCCUR DEPENDING ON CLOUDS. FEEL MORE CONFIDENT NORTHWEST
INDIANA WILL BE MOSTLY CLEAR AND TOUCH SOME OF THOSE LOWER TO MID
TEENS.
DURING THE DAY WEDNESDAY...A THERMAL RIDGE BUILDS INTO THE AREA AND
EXPECTING AT LEAST SOME SUNSHINE AS SOUTHWESTERLY LOW-LEVEL FLOW
WILL BE ENOUGH TO ADVECT OUT ANY RESIDUAL LOW CLOUDS. THE WARMEST
PART OF THE THERMAL RIDGE REACHES US MORE SO WEDNESDAY NIGHT AND
CLIMATOLOGY FOR FORECAST 925MB TEMPERATURES WOULD KEEP
SURFACE READINGS IN THE 30S FOR MOST OF THE CWA ESPECIALLY WITH
SOME SNOW COVER ALBEIT MINIMAL.
MTF
&&
.LONG TERM...
330 AM CST
WEDNESDAY NIGHT THROUGH MONDAY...
THE NEXT CHANCE FOR PRECIPITATION IS WEDNESDAY NIGHT AND
THURSDAY...AND CONFIDENCE HAS FURTHER INCREASED THAT THIS WILL BE A
LIGHT PRECIPITATION EVENT...AS WELL AS ONE WITH ONLY LIQUID
WEDNESDAY NIGHT IF PRECIPITATION DEVELOPS OVER OUR AREA. A CLOSED
UPPER LOW NEAR LOS ANGELES EARLY THIS MORNING IS STILL FORECAST TO
GET CAUGHT IN THE WESTERLIES AND DAMPEN THE STRONG UPPER RIDGE IN
PLACE OVER THE ROCKIES. A GRADUAL PHASING WITH A NORTHERN STREAM
PROGRESSIVE WAVE IS EXPECTED WEDNESDAY NIGHT THROUGH THURSDAY
OVER THE GREAT LAKES REGION. WHILE THE 27.00 GFS IS MORE
AGGRESSIVE WITH THIS PHASING THAN OTHER 27.00 GUIDANCE...IT ONLY
BRINGS A LITTLE MORE OOMPH FOR PRECIP HERE. THE THERMAL RIDGE
MENTIONED IN THE SHORT TERM SECTION FOR WEDNESDAY IS 2C-6C AT
850-925MB AND SURFACE TEMPERATURES ARE NOT LIKELY TO DROP GIVEN
THE SOUTHERN FLOW AND INCREASING CLOUDS...SO HAVE CHANCES OF RAIN
AND DRIZZLE WEDNESDAY NIGHT AS MOISTURE TRANSPORT DEVELOPS. ON
THURSDAY...TRANSITION TO A LIGHT RAIN AND SNOW MIX AND AT THIS
POINT WPC AND OURSELVES REALLY HAVE NO ACCUMULATIONS FORECAST.
HAVE STILL TRIED TO TAKE INTO ACCOUNT SOME POSSIBLE SLOWING IN THE
FORECAST GIVEN THE CURRENT SIGNIFICANT CLOSED SYSTEM OFF THE
NORTHEAST U.S...AND KEPT PRECIP CHANCES INTO THURSDAY AFTERNOON.
THE PROGRESSIVE ACTIVE FLOW PATTERN IS FORECAST TO CONTINUE INTO
THE WEEKEND...WITH STRONG HIGH PRESSURE ON FRIDAY GIVING WAY TO
PRECIPITATION CHANCES THIS WEEKEND. ANOTHER CLOSED LOW OVER THE
FAR SOUTHWESTERN U.S. IS FORECAST TO MOVE GRADUALLY EASTWARD AND
LOOKS TO BE ABLE TO TAP INTO GULF AND EASTERN PACIFIC MOISTURE.
WITH A CUT-OFF FEATURE THIS COULD END UP SLOWING AND CERTAINLY
CHANGING IN EVOLUTION. GUIDANCE DISAGREES HOW ANY NORTHERN STREAM
DISTURBANCE MAY AID TO PULL SOME OF THIS MOISTURE OVER OUR AREA.
AT THIS TIME THIS LOOKS TO BE A POSSIBLY LONG DURATION BUT LIGHT
INTENSITY QPF EVENT AT THIS LATITUDE. GIVEN THE FEATURES AT PLAY
AND CURRENT PATTERN WE ARE IN...ITS JUST WAY TOO EARLY AS
POTENTIAL COULD GO EITHER WAY FROM THAT SOLUTION. CONFIDENCE IS A
LITTLE HIGHER IN THAT IT WOULD PROBABLY BE A MAINLY SNOW EVENT IF
IT WERE TO OCCUR. GUIDANCE IS IN BETTER AGREEMENT THAN 24 HOURS
AGO WITH A CANADIAN/MODIFIED ARCTIC AIR MASS BEING TAPPED IN THE
WAKE OF THIS SYSTEM WITH POSSIBLY SINGLE DIGIT NIGHTTIME
TEMPERATURES DEPENDING ON IF ANY FRESH SNOW COVER CAN OCCUR.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* CIGS SCATTERING TO VFR LATER THIS AFTERNOON.
* NORTHEAST WINDS AROUND 10 KT TODAY...BECOMING LIGHT/VARIABLE
AGAIN THIS EVENING/OVERNIGHT.
RATZER/DEUBELBEISS
//DISCUSSION...UPDATED 12Z...
WEAK LOW PRESSURE SYSTEM CONTINUES TO PULL AWAY TO THE SOUTHEAST
THIS MORNING...WITH A LINGERING SURFACE TROUGH REMAINING THE FOCUS
FOR AN AREA OF LOW CLOUDS...MVFR FOG AND SOME PATCHY LIGHT
FREEZING DRIZZLE. MID-LEVEL DISTURBANCE OVERHEAD AND WILL MOVE OFF
TO THE SOUTHEAST THIS MORNING...WHICH ALONG WITH DRIER NORTHEAST
WINDS DEVELOPING ABOVE THE SURFACE SHOULD LEAD TO DIMINISHING
POTENTIAL FOR -FZDZ BY MID-MORNING. DRIER AIR FROM THE NORTHEAST
SHOULD ALSO WORK TO RAISE CIGS AND IMPROVE VIS THROUGH THE MORNING
AND EARLY AFTERNOON HOURS AS WELL. WEAK HIGH PRESSURE WILL SPREAD
ACROSS THE AREA FROM THE NORTHWEST THIS EVENING...WITH VFR
CONDITIONS...THOUGH RFD/DPA COULD SEE SOME SHALLOW FOG DEVELOP
OVERNIGHT.
NORTH-NORTHEAST WINDS EARLY THIS MORNING WILL BECOME MORE SOLIDLY
NORTHEAST DURING THE MORNING...AROUND 10 KT. WINDS WILL DIMINISH
TOWARD EVENING AS GRADIENT WEAKENS WITH APPROACH OF THE HIGH...
WITH LIGHT/VARIABLE WINDS THIS EVENING AND OVERNIGHT. WITH THE
HIGH SHIFTING SOUTHEAST OF THE AREA EARLY WEDNESDAY...SOUTH WINDS
WILL DEVELOP.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM IN TIMING IMPROVEMENT FROM MVFR TO VFR.
* HIGH IN WIND TRENDS.
RATZER/DEUBELBEISS
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...CHANCE OF RAIN/DRIZZLE. MVFR/IFR POSSIBLE.
THURSDAY...CHANCE OF RAIN/SNOW. MVFR LIKELY/IFR POSSIBLE.
FRIDAY AND SATURDAY...PRIMARILY VFR. CHANCE OF SNOW SATURDAY
NIGHT.
SUNDAY...CHANCE OF LIGHT SNOW. IFR POSSIBLE.
MONDAY...MVFR CIGS POSSIBLE.
RATZER
&&
.MARINE...
213 AM CST
MARINE CONCERNS ON LAKE MICHIGAN ARE A PERIOD OF STRONG SOUTH WINDS
WEDNESDAY AFTERNOON AND NIGHT...THEN A SHIFT TO STRONG NORTH TO
NORTHWEST WINDS THURSDAY AFTERNOON INTO EARLY FRIDAY...WITH THE
POTENTIAL FOR A PERIOD OF NORTHWEST GALES ESPECIALLY THURSDAY
AFTERNOON AND THURSDAY EVENING.
IN THE NEAR TERM...RELATIVELY QUIET WEATHER ACROSS THE LAKE EARLY
THIS MORNING AS A WEAKENING SURFACE TROUGH OVER ILLINOIS AND THE
LOWER OHIO VALLEY CONTINUES TO MOVE OFF TO THE SOUTHEAST...ALLOWING
WEAK HIGH PRESSURE TO SETTLE ACROSS THE AREA FROM THE NORTH TODAY.
LOOKING TO THE WEST...AN AREA OF LOW PRESSURE DEVELOPING IN THE LEE
OF THE CANADIAN ROCKIES WILL SLIDE SOUTHEAST INTO THE PLAINS
THROUGH TONIGHT...THEN WILL MOVE SLOWLY EAST TOWARD LAKE MICHIGAN
WEDNESDAY AND WEDNESDAY NIGHT. IN RESPONSE TO PRESSURE FALLS AHEAD
OF THE LOW...THE GRADIENT WILL TIGHTEN ACROSS LAKE MICHIGAN
WEDNESDAY WITH SOUTH WINDS RAMPING UP INTO THE 30 KT RANGE BY LATE
AFTERNOON AND EVENING. WINDS WILL DIMINISH BRIEFLY EARLY THURSDAY
MORNING AS THE LOW PRESSURE CENTER AND COLD FRONTAL TROUGH CROSS THE
LAKE...BEFORE WINDS SHIFT TO THE NORTH-NORTHWEST AND INCREASE
QUICKLY BACK INTO THE 30-35 KT RANGE THURSDAY AFTERNOON. FORECAST
SOUNDINGS INDICATE THE POTENTIAL FOR GALES THURSDAY AFTERNOON AND
EVENING IN THE STRONG PRESSURE RISES AND COLD ADVECTION BEHIND THE
DEPARTING LOW AND COLD FRONT. THESE STRONG WINDS WILL CONTINUE INTO
EARLY FRIDAY...BEFORE DIMINISHING AS A BROAD AREA OF HIGH PRESSURE
SPREADS INTO THE AREA BY FRIDAY EVENING. THE HIGH WILL SLOWLY MOVE
OFF TO THE EAST ON SATURDAY...WITH A WEAK LOW EXPECTED TO PASS
ACROSS THE NORTHERN LAKES SATURDAY NIGHT AND TRAIL A COLD FRONT
ACROSS LAKE MICHIGAN THROUGH SUNDAY.
FOR THE ILLINOIS AND NORTHWEST INDIANA NEARSHORE WATERS SMALL CRAFT
ADVISORY CONDITIONS LOOK TO DEVELOP WEDNESDAY AFTERNOON AND CONTINUE
THROUGH THURSDAY MORNING...WITH A BRIEF BREAK BEFORE HIGH WIND/WAVE
CONDITIONS DEVELOP AGAIN BY EARLY THURSDAY AFTERNOON. HIGH WAVES
WOULD LIKELY LINGER THROUGH MUCH OF FRIDAY...ESPECIALLY ALONG THE
INDIANA SHORE EAST OF GARY.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
541 AM CST TUE JAN 27 2015
.SHORT TERM...
330 AM CST
THROUGH WEDNESDAY...
INFRARED AND WATER VAPOR SATELLITE LOOPS EARLY THIS MORNING HAVE
SHOWN THE LAST IN A SERIES OF SHEARED VORTICITY MAXIMA TO HAVE MOVED
SOUTHEAST OF THE AREA. LIGHT SNOW ASSOCIATED WITH THESE HAS MAINLY
ENDED. LOW-LEVEL WINDS HAVE ALSO SHIFTED MORE NORTHERLY AS A
SURFACE INDUCED TROUGH AXIS PULLS AWAY. THIS HAS ENDED THE LOW-
LEVEL ISENTROPIC ASCENT AND OMEGA WHICH HELPED TO INDUCE MUCH OF
THE FREEZING DRIZZLE LAST NIGHT. SO WITH THAT HAVE CANCELLED THE
ADVISORY AS THE WIDESPREAD THREAT HAS ENDED GOING INTO THE RUSH
HOUR. ONE HOPEFULLY ONLY SMALL FLY IN THE OINTMENT TO THIS IS THE
CHANCE FOR FREEZING DRIZZLE LINGERING IN MAINLY LAKE AND COOK
COUNTIES...INCLUDING CHICAGO...AS WINDS TURN OFF THE LAKE EARLY
THIS MORNING STEERING IN SOME MARGINAL LAKE-INDUCED INSTABILITY.
THE MKX RADAR IS INDICATING LIGHT ECHOES MOVING WESTWARD THAT
DUAL-POL SUGGESTS IS FREEZING DRIZZLE. RAP PROFILES ARE ONLY
SATURATED ABOUT AS COOL AS -8C ADDING SUPPORT TO THAT. WITH NOT
EXPECTING A SITUATION SUCH AS LAST EVENING GIVEN THE TREATMENT ON
ROADS AND THE DIFFERENT MORE MESOSCALE/LOCALIZED INDUCED
LIFT...FEEL BETTER GOING WITH AN SPS IF NEEDED. EXPECT THE CHANCES
TO END BY 10 AM OR SO AS DRIER AIR CONTINUES TO ADVECT WESTWARD
OVER THE LAKE SEEN BY DEW POINTS NEAR 10F ON THE MICHIGAN SHORE
ALONG WITH AN EAST WIND.
CLOUDS SHOULD BE SLOW TO CLEAR TODAY GIVEN THE CURRENT EXPANSIVENESS
TO THE NORTH AND THE CYCLONIC FLOW CONTINUING THROUGH THIS
MORNING...AS WELL AS AFOREMENTIONED LAKE-ORIENTED FLOW INTO
NORTHEAST ILLINOIS. MESOSCALE MODEL MOISTURE/CONDENSATE FIELDS
INDICATE CLOUDS LINGERING THE LONGEST ACROSS THE ILLINOIS PART OF
THE CWA WITH INDIANA EXPERIENCING NORTHEASTERLY DRY ADVECTION.
HAVE HIGHS ONLY A FEW DEGREES WARMER THAN CURRENT EARLY MORNING
VALUES GIVEN THIS THOUGHT PROCESS. CONFIDENCE IS LOW ON WHETHER
CLEARING OCCURS AREAWIDE LATE THIS AFTERNOON AND EVENING AS
GUIDANCE WOULD SUGGEST...PLUS THERE WILL LIKELY BE CIRRUS
SPREADING IN TOO. THIS INTRODUCES BUST POTENTIAL IN LOW
TEMPERATURES OVER NORTH CENTRAL ILLINOIS WHERE LOW TEENS TO MID
20S COULD OCCUR DEPENDING ON CLOUDS. FEEL MORE CONFIDENT NORTHWEST
INDIANA WILL BE MOSTLY CLEAR AND TOUCH SOME OF THOSE LOWER TO MID
TEENS.
DURING THE DAY WEDNESDAY...A THERMAL RIDGE BUILDS INTO THE AREA AND
EXPECTING AT LEAST SOME SUNSHINE AS SOUTHWESTERLY LOW-LEVEL FLOW
WILL BE ENOUGH TO ADVECT OUT ANY RESIDUAL LOW CLOUDS. THE WARMEST
PART OF THE THERMAL RIDGE REACHES US MORE SO WEDNESDAY NIGHT AND
CLIMATOLOGY FOR FORECAST 925MB TEMPERATURES WOULD KEEP
SURFACE READINGS IN THE 30S FOR MOST OF THE CWA ESPECIALLY WITH
SOME SNOW COVER ALBEIT MINIMAL.
MTF
&&
.LONG TERM...
330 AM CST
WEDNESDAY NIGHT THROUGH MONDAY...
THE NEXT CHANCE FOR PRECIPITATION IS WEDNESDAY NIGHT AND
THURSDAY...AND CONFIDENCE HAS FURTHER INCREASED THAT THIS WILL BE A
LIGHT PRECIPITATION EVENT...AS WELL AS ONE WITH ONLY LIQUID
WEDNESDAY NIGHT IF PRECIPITATION DEVELOPS OVER OUR AREA. A CLOSED
UPPER LOW NEAR LOS ANGELES EARLY THIS MORNING IS STILL FORECAST TO
GET CAUGHT IN THE WESTERLIES AND DAMPEN THE STRONG UPPER RIDGE IN
PLACE OVER THE ROCKIES. A GRADUAL PHASING WITH A NORTHERN STREAM
PROGRESSIVE WAVE IS EXPECTED WEDNESDAY NIGHT THROUGH THURSDAY
OVER THE GREAT LAKES REGION. WHILE THE 27.00 GFS IS MORE
AGGRESSIVE WITH THIS PHASING THAN OTHER 27.00 GUIDANCE...IT ONLY
BRINGS A LITTLE MORE OOMPH FOR PRECIP HERE. THE THERMAL RIDGE
MENTIONED IN THE SHORT TERM SECTION FOR WEDNESDAY IS 2C-6C AT
850-925MB AND SURFACE TEMPERATURES ARE NOT LIKELY TO DROP GIVEN
THE SOUTHERN FLOW AND INCREASING CLOUDS...SO HAVE CHANCES OF RAIN
AND DRIZZLE WEDNESDAY NIGHT AS MOISTURE TRANSPORT DEVELOPS. ON
THURSDAY...TRANSITION TO A LIGHT RAIN AND SNOW MIX AND AT THIS
POINT WPC AND OURSELVES REALLY HAVE NO ACCUMULATIONS FORECAST.
HAVE STILL TRIED TO TAKE INTO ACCOUNT SOME POSSIBLE SLOWING IN THE
FORECAST GIVEN THE CURRENT SIGNIFICANT CLOSED SYSTEM OFF THE
NORTHEAST U.S...AND KEPT PRECIP CHANCES INTO THURSDAY AFTERNOON.
THE PROGRESSIVE ACTIVE FLOW PATTERN IS FORECAST TO CONTINUE INTO
THE WEEKEND...WITH STRONG HIGH PRESSURE ON FRIDAY GIVING WAY TO
PRECIPITATION CHANCES THIS WEEKEND. ANOTHER CLOSED LOW OVER THE
FAR SOUTHWESTERN U.S. IS FORECAST TO MOVE GRADUALLY EASTWARD AND
LOOKS TO BE ABLE TO TAP INTO GULF AND EASTERN PACIFIC MOISTURE.
WITH A CUT-OFF FEATURE THIS COULD END UP SLOWING AND CERTAINLY
CHANGING IN EVOLUTION. GUIDANCE DISAGREES HOW ANY NORTHERN STREAM
DISTURBANCE MAY AID TO PULL SOME OF THIS MOISTURE OVER OUR AREA.
AT THIS TIME THIS LOOKS TO BE A POSSIBLY LONG DURATION BUT LIGHT
INTENSITY QPF EVENT AT THIS LATITUDE. GIVEN THE FEATURES AT PLAY
AND CURRENT PATTERN WE ARE IN...ITS JUST WAY TOO EARLY AS
POTENTIAL COULD GO EITHER WAY FROM THAT SOLUTION. CONFIDENCE IS A
LITTLE HIGHER IN THAT IT WOULD PROBABLY BE A MAINLY SNOW EVENT IF
IT WERE TO OCCUR. GUIDANCE IS IN BETTER AGREEMENT THAN 24 HOURS
AGO WITH A CANADIAN/MODIFIED ARCTIC AIR MASS BEING TAPPED IN THE
WAKE OF THIS SYSTEM WITH POSSIBLY SINGLE DIGIT NIGHTTIME
TEMPERATURES DEPENDING ON IF ANY FRESH SNOW COVER CAN OCCUR.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* PERIOD OF IFR CIGS/MVFR VIS IN FOG AND PATCHY LIGHT FREEZING
DRIZZLE EARLY THIS MORNING.
* CIGS IMPROVING TO MVFR BY LATE MORNING...SCATTERING TO VFR LATER
THIS AFTERNOON.
* NORTHEAST WINDS AROUND 10 KT TODAY...BECOMING LIGHT/VARIABLE
AGAIN THIS EVENING/OVERNIGHT.
RATZER
//DISCUSSION...UPDATED 12Z...
WEAK LOW PRESSURE SYSTEM CONTINUES TO PULL AWAY TO THE SOUTHEAST
THIS MORNING...WITH A LINGERING SURFACE TROUGH REMAINING THE FOCUS
FOR AN AREA OF LOW CLOUDS...MVFR FOG AND SOME PATCHY LIGHT
FREEZING DRIZZLE. MID-LEVEL DISTURBANCE OVERHEAD AND WILL MOVE OFF
TO THE SOUTHEAST THIS MORNING...WHICH ALONG WITH DRIER NORTHEAST
WINDS DEVELOPING ABOVE THE SURFACE SHOULD LEAD TO DIMINISHING
POTENTIAL FOR -FZDZ BY MID-MORNING. DRIER AIR FROM THE NORTHEAST
SHOULD ALSO WORK TO RAISE CIGS AND IMPROVE VIS THROUGH THE MORNING
AND EARLY AFTERNOON HOURS AS WELL. WEAK HIGH PRESSURE WILL SPREAD
ACROSS THE AREA FROM THE NORTHWEST THIS EVENING...WITH VFR
CONDITIONS...THOUGH RFD/DPA COULD SEE SOME SHALLOW FOG DEVELOP
OVERNIGHT.
NORTH-NORTHEAST WINDS EARLY THIS MORNING WILL BECOME MORE SOLIDLY
NORTHEAST DURING THE MORNING...AROUND 10 KT. WINDS WILL DIMINISH
TOWARD EVENING AS GRADIENT WEAKENS WITH APPROACH OF THE HIGH...
WITH LIGHT/VARIABLE WINDS THIS EVENING AND OVERNIGHT. WITH THE
HIGH SHIFTING SOUTHEAST OF THE AREA EARLY WEDNESDAY...SOUTH WINDS
WILL DEVELOP.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* MEDIUM-HIGH IN CIG/VIS TRENDS THIS MORNING. MEDIUM IN TIMING
IMPROVEMENT FROM IFR TO MVFR AND MVFR TO VFR.
* HIGH IN WIND TRENDS.
RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...CHANCE OF RAIN/DRIZZLE. MVFR/IFR POSSIBLE.
THURSDAY...CHANCE OF RAIN/SNOW. MVFR LIKELY/IFR POSSIBLE.
FRIDAY AND SATURDAY...PRIMARILY VFR. CHANCE OF SNOW SATURDAY
NIGHT.
SUNDAY...CHANCE OF LIGHT SNOW. IFR POSSIBLE.
MONDAY...MVFR CIGS POSSIBLE.
RATZER
&&
.MARINE...
213 AM CST
MARINE CONCERNS ON LAKE MICHIGAN ARE A PERIOD OF STRONG SOUTH WINDS
WEDNESDAY AFTERNOON AND NIGHT...THEN A SHIFT TO STRONG NORTH TO
NORTHWEST WINDS THURSDAY AFTERNOON INTO EARLY FRIDAY...WITH THE
POTENTIAL FOR A PERIOD OF NORTHWEST GALES ESPECIALLY THURSDAY
AFTERNOON AND THURSDAY EVENING.
IN THE NEAR TERM...RELATIVELY QUIET WEATHER ACROSS THE LAKE EARLY
THIS MORNING AS A WEAKENING SURFACE TROUGH OVER ILLINOIS AND THE
LOWER OHIO VALLEY CONTINUES TO MOVE OFF TO THE SOUTHEAST...ALLOWING
WEAK HIGH PRESSURE TO SETTLE ACROSS THE AREA FROM THE NORTH TODAY.
LOOKING TO THE WEST...AN AREA OF LOW PRESSURE DEVELOPING IN THE LEE
OF THE CANADIAN ROCKIES WILL SLIDE SOUTHEAST INTO THE PLAINS
THROUGH TONIGHT...THEN WILL MOVE SLOWLY EAST TOWARD LAKE MICHIGAN
WEDNESDAY AND WEDNESDAY NIGHT. IN RESPONSE TO PRESSURE FALLS AHEAD
OF THE LOW...THE GRADIENT WILL TIGHTEN ACROSS LAKE MICHIGAN
WEDNESDAY WITH SOUTH WINDS RAMPING UP INTO THE 30 KT RANGE BY LATE
AFTERNOON AND EVENING. WINDS WILL DIMINISH BRIEFLY EARLY THURSDAY
MORNING AS THE LOW PRESSURE CENTER AND COLD FRONTAL TROUGH CROSS THE
LAKE...BEFORE WINDS SHIFT TO THE NORTH-NORTHWEST AND INCREASE
QUICKLY BACK INTO THE 30-35 KT RANGE THURSDAY AFTERNOON. FORECAST
SOUNDINGS INDICATE THE POTENTIAL FOR GALES THURSDAY AFTERNOON AND
EVENING IN THE STRONG PRESSURE RISES AND COLD ADVECTION BEHIND THE
DEPARTING LOW AND COLD FRONT. THESE STRONG WINDS WILL CONTINUE INTO
EARLY FRIDAY...BEFORE DIMINISHING AS A BROAD AREA OF HIGH PRESSURE
SPREADS INTO THE AREA BY FRIDAY EVENING. THE HIGH WILL SLOWLY MOVE
OFF TO THE EAST ON SATURDAY...WITH A WEAK LOW EXPECTED TO PASS
ACROSS THE NORTHERN LAKES SATURDAY NIGHT AND TRAIL A COLD FRONT
ACROSS LAKE MICHIGAN THROUGH SUNDAY.
FOR THE ILLINOIS AND NORTHWEST INDIANA NEARSHORE WATERS SMALL CRAFT
ADVISORY CONDITIONS LOOK TO DEVELOP WEDNESDAY AFTERNOON AND CONTINUE
THROUGH THURSDAY MORNING...WITH A BRIEF BREAK BEFORE HIGH WIND/WAVE
CONDITIONS DEVELOP AGAIN BY EARLY THURSDAY AFTERNOON. HIGH WAVES
WOULD LIKELY LINGER THROUGH MUCH OF FRIDAY...ESPECIALLY ALONG THE
INDIANA SHORE EAST OF GARY.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
336 AM CST TUE JAN 27 2015
.SHORT TERM...
330 AM CST
THROUGH WEDNESDAY...
INFRARED AND WATER VAPOR SATELLITE LOOPS EARLY THIS MORNING HAVE
SHOWN THE LAST IN A SERIES OF SHEARED VORTICITY MAXIMA TO HAVE MOVED
SOUTHEAST OF THE AREA. LIGHT SNOW ASSOCIATED WITH THESE HAS MAINLY
ENDED. LOW-LEVEL WINDS HAVE ALSO SHIFTED MORE NORTHERLY AS A
SURFACE INDUCED TROUGH AXIS PULLS AWAY. THIS HAS ENDED THE LOW-
LEVEL ISENTROPIC ASCENT AND OMEGA WHICH HELPED TO INDUCE MUCH OF
THE FREEZING DRIZZLE LAST NIGHT. SO WITH THAT HAVE CANCELLED THE
ADVISORY AS THE WIDESPREAD THREAT HAS ENDED GOING INTO THE RUSH
HOUR. ONE HOPEFULLY ONLY SMALL FLY IN THE OINTMENT TO THIS IS THE
CHANCE FOR FREEZING DRIZZLE LINGERING IN MAINLY LAKE AND COOK
COUNTIES...INCLUDING CHICAGO...AS WINDS TURN OFF THE LAKE EARLY
THIS MORNING STEERING IN SOME MARGINAL LAKE-INDUCED INSTABILITY.
THE MKX RADAR IS INDICATING LIGHT ECHOES MOVING WESTWARD THAT
DUAL-POL SUGGESTS IS FREEZING DRIZZLE. RAP PROFILES ARE ONLY
SATURATED ABOUT AS COOL AS -8C ADDING SUPPORT TO THAT. WITH NOT
EXPECTING A SITUATION SUCH AS LAST EVENING GIVEN THE TREATMENT ON
ROADS AND THE DIFFERENT MORE MESOSCALE/LOCALIZED INDUCED
LIFT...FEEL BETTER GOING WITH AN SPS IF NEEDED. EXPECT THE CHANCES
TO END BY 10 AM OR SO AS DRIER AIR CONTINUES TO ADVECT WESTWARD
OVER THE LAKE SEEN BY DEW POINTS NEAR 10F ON THE MICHIGAN SHORE
ALONG WITH AN EAST WIND.
CLOUDS SHOULD BE SLOW TO CLEAR TODAY GIVEN THE CURRENT EXPANSIVENESS
TO THE NORTH AND THE CYCLONIC FLOW CONTINUING THROUGH THIS
MORNING...AS WELL AS AFOREMENTIONED LAKE-ORIENTED FLOW INTO
NORTHEAST ILLINOIS. MESOSCALE MODEL MOISTURE/CONDENSATE FIELDS
INDICATE CLOUDS LINGERING THE LONGEST ACROSS THE ILLINOIS PART OF
THE CWA WITH INDIANA EXPERIENCING NORTHEASTERLY DRY ADVECTION.
HAVE HIGHS ONLY A FEW DEGREES WARMER THAN CURRENT EARLY MORNING
VALUES GIVEN THIS THOUGHT PROCESS. CONFIDENCE IS LOW ON WHETHER
CLEARING OCCURS AREAWIDE LATE THIS AFTERNOON AND EVENING AS
GUIDANCE WOULD SUGGEST...PLUS THERE WILL LIKELY BE CIRRUS
SPREADING IN TOO. THIS INTRODUCES BUST POTENTIAL IN LOW
TEMPERATURES OVER NORTH CENTRAL ILLINOIS WHERE LOW TEENS TO MID
20S COULD OCCUR DEPENDING ON CLOUDS. FEEL MORE CONFIDENT NORTHWEST
INDIANA WILL BE MOSTLY CLEAR AND TOUCH SOME OF THOSE LOWER TO MID
TEENS.
DURING THE DAY WEDNESDAY...A THERMAL RIDGE BUILDS INTO THE AREA AND
EXPECTING AT LEAST SOME SUNSHINE AS SOUTHWESTERLY LOW-LEVEL FLOW
WILL BE ENOUGH TO ADVECT OUT ANY RESIDUAL LOW CLOUDS. THE WARMEST
PART OF THE THERMAL RIDGE REACHES US MORE SO WEDNESDAY NIGHT AND
CLIMATOLOGY FOR FORECAST 925MB TEMPERATURES WOULD KEEP
SURFACE READINGS IN THE 30S FOR MOST OF THE CWA ESPECIALLY WITH
SOME SNOW COVER ALBEIT MINIMAL.
MTF
&&
.LONG TERM...
330 AM CST
WEDNESDAY NIGHT THROUGH MONDAY...
THE NEXT CHANCE FOR PRECIPITATION IS WEDNESDAY NIGHT AND
THURSDAY...AND CONFIDENCE HAS FURTHER INCREASED THAT THIS WILL BE A
LIGHT PRECIPITATION EVENT...AS WELL AS ONE WITH ONLY LIQUID
WEDNESDAY NIGHT IF PRECIPITATION DEVELOPS OVER OUR AREA. A CLOSED
UPPER LOW NEAR LOS ANGELES EARLY THIS MORNING IS STILL FORECAST TO
GET CAUGHT IN THE WESTERLIES AND DAMPEN THE STRONG UPPER RIDGE IN
PLACE OVER THE ROCKIES. A GRADUAL PHASING WITH A NORTHERN STREAM
PROGRESSIVE WAVE IS EXPECTED WEDNESDAY NIGHT THROUGH THURSDAY
OVER THE GREAT LAKES REGION. WHILE THE 27.00 GFS IS MORE
AGGRESSIVE WITH THIS PHASING THAN OTHER 27.00 GUIDANCE...IT ONLY
BRINGS A LITTLE MORE OOMPH FOR PRECIP HERE. THE THERMAL RIDGE
MENTIONED IN THE SHORT TERM SECTION FOR WEDNESDAY IS 2C-6C AT
850-925MB AND SURFACE TEMPERATURES ARE NOT LIKELY TO DROP GIVEN
THE SOUTHERN FLOW AND INCREASING CLOUDS...SO HAVE CHANCES OF RAIN
AND DRIZZLE WEDNESDAY NIGHT AS MOISTURE TRANSPORT DEVELOPS. ON
THURSDAY...TRANSITION TO A LIGHT RAIN AND SNOW MIX AND AT THIS
POINT WPC AND OURSELVES REALLY HAVE NO ACCUMULATIONS FORECAST.
HAVE STILL TRIED TO TAKE INTO ACCOUNT SOME POSSIBLE SLOWING IN THE
FORECAST GIVEN THE CURRENT SIGNIFICANT CLOSED SYSTEM OFF THE
NORTHEAST U.S...AND KEPT PRECIP CHANCES INTO THURSDAY AFTERNOON.
THE PROGRESSIVE ACTIVE FLOW PATTERN IS FORECAST TO CONTINUE INTO
THE WEEKEND...WITH STRONG HIGH PRESSURE ON FRIDAY GIVING WAY TO
PRECIPITATION CHANCES THIS WEEKEND. ANOTHER CLOSED LOW OVER THE
FAR SOUTHWESTERN U.S. IS FORECAST TO MOVE GRADUALLY EASTWARD AND
LOOKS TO BE ABLE TO TAP INTO GULF AND EASTERN PACIFIC MOISTURE.
WITH A CUT-OFF FEATURE THIS COULD END UP SLOWING AND CERTAINLY
CHANGING IN EVOLUTION. GUIDANCE DISAGREES HOW ANY NORTHERN STREAM
DISTURBANCE MAY AID TO PULL SOME OF THIS MOISTURE OVER OUR AREA.
AT THIS TIME THIS LOOKS TO BE A POSSIBLY LONG DURATION BUT LIGHT
INTENSITY QPF EVENT AT THIS LATITUDE. GIVEN THE FEATURES AT PLAY
AND CURRENT PATTERN WE ARE IN...ITS JUST WAY TOO EARLY AS
POTENTIAL COULD GO EITHER WAY FROM THAT SOLUTION. CONFIDENCE IS A
LITTLE HIGHER IN THAT IT WOULD PROBABLY BE A MAINLY SNOW EVENT IF
IT WERE TO OCCUR. GUIDANCE IS IN BETTER AGREEMENT THAN 24 HOURS
AGO WITH A CANADIAN/MODIFIED ARCTIC AIR MASS BEING TAPPED IN THE
WAKE OF THIS SYSTEM WITH POSSIBLY SINGLE DIGIT NIGHTTIME
TEMPERATURES DEPENDING ON IF ANY FRESH SNOW COVER CAN OCCUR.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* LOW-MVFR/OCCASIONALLY HIGH-IFR CIG EARLY THIS MORNING. SPOTTY
LIGHT FREEZING DRIZZLE ALSO POSSIBLE THROUGH SUNRISE.
* CIGS EXPECTED TO IMPROVE TO SOLID MID-HIGH RANGE MVFR AFTER
SUNRISE...SCATTERING TO VFR BY MID-AFTERNOON.
* LIGHT NORTH-NORTHEAST WINDS...BECOMING NORTHEAST AND INCREASING
TO AROUND 10 KT DURING THE DAY.
RATZER
//DISCUSSION...UPDATED 09Z...
MID-LEVEL DISTURBANCE MOVING THROUGH WITH TRAILING EDGE OF MORE
ORGANIZED LIGHT SNOW NOW EXITING TO THE SOUTHEAST. WEAK CONVERGENT
LOW LEVEL WIND FIELD MAY STILL ALLOW FOR A LITTLE PATCHY LIGHT
FREEZING DRIZZLE FOR THE NEXT FEW HOURS GIVEN SATURATED LOW
LEVELS. CIGS HIGH-END IFR OR LOW-END MVFR SHOULD SHOW A GRADUAL
RISING TREND AS DRIER AIR SLOWLY ARRIVES FROM THE NORTHEAST.
RATZER
PREVIOUS DISCUSSION FROM 06Z...
ELONGATED/SHEARED MID-LEVEL DISTURBANCE CONTINUES TO PROPAGATE
SOUTHEASTWARD ACROSS THE FORECAST AREA AT MIDNIGHT...PRODUCING AN
AREA OF LIGHT SNOW AND SOME FREEZING DRIZZLE ACROSS SOUTHEAST
WISCONSIN AND NORTHEAST IL/NORTHWEST INDIANA. EXTRAPOLATION OF
RADAR FEATURES...WHICH COINCIDES WITH IR COLDER CLOUD TOPS AND AND
MODEL FORECAST OF SHEARED MID-LEVEL CIRCULATION...SUGGESTS MORE
ORGANIZED PRECIPITATION SHOULD END BY 10Z OR SO FOR THE CHICAGO
TERMINALS AND A COUPLE OF HOURS EARLIER FOR RFD. FORECAST
SOUNDINGS DO DEPICT LOW LEVELS REMAINING VERY MOIST AND CAPABLE OF
PRODUCING LIGHT FREEZING DRIZZLE/FLURRIES (SNIZZLE) AND AT LEAST
PATCHY IFR CIGS THROUGH SUNRISE OR SO...BEFORE INCREASING NORTH-
NORTHEAST BOUNDARY LAYER WINDS REALLY BEGIN TO DRY OUT THE LOWER
LEVELS. CONCURRENT WITH THAT...THERE SHOULD BE A STEADY
IMPROVEMENT IN CIG/VIS AND EVENTUALLY SCATTERING TO VFR IS
EXPECTED BY EARLY-MID AFTERNOON.
AS FOR WINDS...WEAK SURFACE LOW/TROUGH ACROSS IL WILL MOVE OFF TO
THE SOUTHEAST ACROSS THE OHIO RIVER THIS MORNING...ALLOWING LIGHT
SOUTHEAST (OR CALM/VARIABLE AT RFD) WINDS TO BACK TO THE NORTHEAST
AND EVENTUALLY INCREASE TO AROUND 10 KT LATER THIS MORNING. WEAK
HIGH PRESSURE RIDGE THEN MOVES INTO THE REGION TONIGHT ALLOWING
LIGHT WINDS TO VEER TO THE SOUTHEAST AGAIN.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 09...
* HIGH IN ANY -FZDZ BEING LIGHT EARLY THIS AM.
* HIGH IN WIND TRENDS.
* MEDIUM WITH CIG/VIS TRENDS REMAINDER OF OVERNIGHT/EARLY MORNING
HOURS.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...VFR THEN CHANCE FOR LIGHT RAIN OR DRIZZLE WEDNESDAY
NIGHT AND POTENTIAL FOR MVFR/IFR.
THURSDAY...CHANCE OF LIGHT SNOW OR LIGHT RAIN/SNOW MIX/ MVFR
LIKELY/IFR POSSIBLE.
FRIDAY...NORTH WINDS. PRIMARILY VFR.
SATURDAY AND SUNDAY...CHANCE OF LIGHT SNOW SATURDAY NIGHT INTO
SUNDAY. IFR POSSIBLE.
RC
&&
.MARINE...
213 AM CST
MARINE CONCERNS ON LAKE MICHIGAN ARE A PERIOD OF STRONG SOUTH WINDS
WEDNESDAY AFTERNOON AND NIGHT...THEN A SHIFT TO STRONG NORTH TO
NORTHWEST WINDS THURSDAY AFTERNOON INTO EARLY FRIDAY...WITH THE
POTENTIAL FOR A PERIOD OF NORTHWEST GALES ESPECIALLY THURSDAY
AFTERNOON AND THURSDAY EVENING.
IN THE NEAR TERM...RELATIVELY QUIET WEATHER ACROSS THE LAKE EARLY
THIS MORNING AS A WEAKENING SURFACE TROUGH OVER ILLINOIS AND THE
LOWER OHIO VALLEY CONTINUES TO MOVE OFF TO THE SOUTHEAST...ALLOWING
WEAK HIGH PRESSURE TO SETTLE ACROSS THE AREA FROM THE NORTH TODAY.
LOOKING TO THE WEST...AN AREA OF LOW PRESSURE DEVELOPING IN THE LEE
OF THE CANADIAN ROCKIES WILL SLIDE SOUTHEAST INTO THE PLAINS
THROUGH TONIGHT...THEN WILL MOVE SLOWLY EAST TOWARD LAKE MICHIGAN
WEDNESDAY AND WEDNESDAY NIGHT. IN RESPONSE TO PRESSURE FALLS AHEAD
OF THE LOW...THE GRADIENT WILL TIGHTEN ACROSS LAKE MICHIGAN
WEDNESDAY WITH SOUTH WINDS RAMPING UP INTO THE 30 KT RANGE BY LATE
AFTERNOON AND EVENING. WINDS WILL DIMINISH BRIEFLY EARLY THURSDAY
MORNING AS THE LOW PRESSURE CENTER AND COLD FRONTAL TROUGH CROSS THE
LAKE...BEFORE WINDS SHIFT TO THE NORTH-NORTHWEST AND INCREASE
QUICKLY BACK INTO THE 30-35 KT RANGE THURSDAY AFTERNOON. FORECAST
SOUNDINGS INDICATE THE POTENTIAL FOR GALES THURSDAY AFTERNOON AND
EVENING IN THE STRONG PRESSURE RISES AND COLD ADVECTION BEHIND THE
DEPARTING LOW AND COLD FRONT. THESE STRONG WINDS WILL CONTINUE INTO
EARLY FRIDAY...BEFORE DIMINISHING AS A BROAD AREA OF HIGH PRESSURE
SPREADS INTO THE AREA BY FRIDAY EVENING. THE HIGH WILL SLOWLY MOVE
OFF TO THE EAST ON SATURDAY...WITH A WEAK LOW EXPECTED TO PASS
ACROSS THE NORTHERN LAKES SATURDAY NIGHT AND TRAIL A COLD FRONT
ACROSS LAKE MICHIGAN THROUGH SUNDAY.
FOR THE ILLINOIS AND NORTHWEST INDIANA NEARSHORE WATERS SMALL CRAFT
ADVISORY CONDITIONS LOOK TO DEVELOP WEDNESDAY AFTERNOON AND CONTINUE
THROUGH THURSDAY MORNING...WITH A BRIEF BREAK BEFORE HIGH WIND/WAVE
CONDITIONS DEVELOP AGAIN BY EARLY THURSDAY AFTERNOON. HIGH WAVES
WOULD LIKELY LINGER THROUGH MUCH OF FRIDAY...ESPECIALLY ALONG THE
INDIANA SHORE EAST OF GARY.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FREEZING RAIN ADVISORY...ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 6 AM
TUESDAY.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1239 PM EST TUE JAN 27 2015
.SYNOPSIS...
ISSUED AT 828 AM EST TUE JAN 27 2015
SKIES WILL CLEAR TODAY WITH TEMPERATURES WARMING INTO THE MID TO
UPPER 20S. TEMPERATURES WILL RISE TO NEAR FREEZING ON WEDNESDAY
WITH PARTLY CLOUDY SKIES. THE NEXT CHANCE OF PRECIPITATION WILL
ARRIVE WEDNESDAY NIGHT AND THURSDAY WITH A WINTRY MIX EXPECTED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 403 AM EST TUE JAN 27 2015
ANOTHER RELATIVELY QUIET SHORT TERM BUT CLOUD CONCERNS AND POSSIBLE
FZDZ THIS MORNING MAKE FOR A FEW ISSUES. FAR WESTERN CWA SATURATED
OVERNIGHT WITH FLURRIES OR VERY LIGHT SNOW FALLING IN DOWNSHEAR SIDE
OF MID LEVEL JET AXIS. ADVISORY ISSUED LAST EVENING FOR FREEZING
DRIZZLE THAT NEVER REALLY MATERIALIZED OVER OUR AREA DUE TO
SATURATED DGZ AND SEEDER FEEDER MECHANISMS ALLOWING FOR SNOW CRYSTAL
GROWTH. HOWEVER...STILL A SLIGHT CONCERN FOR LIGHT FZDZ THROUGH
SUNRISE AS SATELLITE SHOWS WARMING CLOUD TOPS UPSTREAM ACROSS WI
MOVING QUICKLY SOUTH AND LOSS OF HIGHER SEED CLOUDS EXPECTED NEXT
FEW HOURS. HIRES MODEL SOUNDINGS INDEED SHOWING DGZ DRYING OUT EARLY
THIS MORNING IN THE WEST BUT LOW LEVELS ALSO DRYING. THUS CHANCES
FOR ANY PCPN WILL BE DIMINISHING BUT PCPN TYPE OF ANY RESIDUAL PCPN
COULD BE FZDZ. CALLS TO WHITE AND PULASKI COUNTY INDICATE NO
PROBLEMS FROM FZDZ OVERNIGHT AND LITTLE TO NO REPORTS OF FZDZ
UPSTREAM AT THIS HOUR. WITH ADVISORY SET TO EXPIRE AT 6AM ANYWAY
PLAN TO CANCEL EARLY AND HANDLE ANY SPOTTY FREEZING LIQUID
DEVELOPMENT WITH SPECIAL WEATHER STATEMENTS IF NEEDED.
DRY WEDGE IN LOWER LEVELS HAS REMAINED IN PLACE ACROSS REMAINDER OF
CWA WITH LIGHT EASTERLY FLOW AIDING IN DRY AIR ENTRAINMENT. THIS DRY
EASTERLY FLOW ALONG WITH SUBSIDENCE TODAY EXPECTED TO HELP BREAK UP
CLOUDS FROM NORTHEAST TO SOUTHWEST THROUGH THE DAY.
HOWEVER...SATELLITE SHOWS AREA OF STRATUS OVER WI MOVING SLOWLY
SOUTHWARD AND MODELS DO NOT HAVE A GOOD HANDLE ON THIS CLOUD COVER.
LOW LEVEL RH PROGS FROM VARIOUS MODELS ALL SEEM TO SUPPORT DRYING
TODAY FROM THE NORTHEAST BUT RUC13 HAS ALSO SHOWN A TENDENCY FOR
HIGHER RH ACROSS CENTRAL OH TO ADVECT WEST INTO OUR EASTERN AREA
THIS AFTERNOON. ALL THESE CLOUD ISSUES MAKE FOR DIFFICULT FORECAST
TODAY. MOST SURROUNDING OFFICES FAVORING THE CLEARING SCENARIO SO
WILL LEAN TOWARD THE DRYING AND BE OPTIMISTIC WITH SKIES BECOMING
PARTLY CLOUDY AND EVENTUALLY MOSTLY CLEAR TONIGHT. HIGH PRESSURE TO
THEN SLIDE ACROSS THE AREA TONIGHT WITH LIGHT WINDS AND MOSTLY CLEAR
SKIES. THIS SHOULD ALLOW GOOD RADIATIONAL COOLING AND TEMPS TO DROP
BACK TO SINGLE DIGITS EASTERN HALF AND LOWER TEENS WEST WHERE SOME
MID AND HIGH CLOUDS MAY SPILL OVER RIDGE.
&&
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 403 AM EST TUE JAN 27 2015
NEXT CLIPPER-TYPE SYSTEM STILL SLATED TO IMPACT THE AREA LATE
WEDNESDAY NIGHT INTO THURSDAY. THIS WAVE WILL ACTUALLY BE AIDED TO
SOME DEGREE BY ANOTHER VORT MAX LEFTOVER FROM OLD BAJA CUTOFF LOW
CURRENTLY BEING REABSORBED INTO THE MEAN WESTERLIES. STILL SOME
INCONSISTENCIES IN THE MODELS REGARDING WHERE EXACTLY THESE TWO
WAVES TRACK AND HOW THEY INTERACT BUT OUR AREA SHOULD SEE A PERIOD
OF DECENT PV ADVECTION/CVA THAT WILL GENERATE AT LEAST SOME FORCED
ASCENT AND LIGHT PRECIP. THE PROBLEM IS THAT UPPER JET SUPPORT IS
MARGINAL AT BEST AND LATEST CONSENSUS TRACK FORECAST KEEPS THE BEST
LOW LEVEL ISENTROPIC ASCENT AND FRONTOGENESIS GENERALLY NORTH OF OUR
AREA. FURTHERMORE...STRONG LOW LEVEL WAA WILL INTRODUCE A MELTING
LAYER ALOFT (AND EVENTUALLY AT THE SURFACE) THAT WILL MAKE
ACCUMULATING SNOW VERY DIFFICULT WITH A HODGEPODGE OF ALL DIFFERENT
PRECIP TYPES OVER SPACE AND TIME. IMPOSSIBLE TO CORRECTLY NAIL DOWN
EXACT TIMING AND LOCATION OF VARIOUS PRECIP TYPES THIS FAR OUT BUT
DID TRY TO PUT A "BEST GUESS" IN THE GRIDS FOR NOW...BASED ON
CONSENSUS OF FORECAST LOW TRACK AND THERMAL PROFILES. PREFERENCE
LIES WITH A GFS/ECMWF COMBO. NAM SURFACE TEMPS APPEAR TOO COLD AND
QPF AMOUNTS TOO LIGHT. GEM THERMAL PROFILES ARE DECENT BUT KEEPS
PRECIP LOCKED UP TOO FAR NORTH. SUPPOSE THIS IS POSSIBLE IF FORECAST
TRACK IS IN LARGE ERROR BUT SOLUTIONS HAVE BEEN FAIRLY STABLE THUS
FAR AND SUSPECT MOST AREAS WILL SEE AT LEAST SOME LIGHT PRECIP WITH
A MODEST PV ANOMALY PASSING DIRECTLY OVERHEAD. THIS IS ESPECIALLY
TRUE GIVEN SUPERB MOISTURE AVAILABILITY WITH 700MB MIXING RATIOS
OVER 4 G/KG AND PW VALUES AROUND 0.75 INCHES. AS FAR AS PRECIP
TYPES...EXPECT COLD SURFACE TEMPS TO SUPPORT FREEZING RAIN AT THE
ONSET...TRANSITIONING TO ALL RAIN FROM SOUTH TO NORTH EARLY THURSDAY
MORNING. LATENT HEAT RELEASE DUE TO FREEZING AND CONTINUAL WAA WITH
S/SW SURFACE WINDS SHOULD LEAD TO A NONDIURNAL TEMPERATURE TREND AND
A FAIRLY QUICK CHANGEOVER TO RAIN WITH MINIMAL ICE ACCUMULATION.
STILL COULD BE SOME SLICK ROADS DURING THE EARLY MORNING COMMUTE
THOUGH...ESPECIALLY NORTH OF US-30. ATYPICAL DIURNAL TEMP TREND
CONTINUES ON THURSDAY WITH HIGHS PROBABLY OCCURRING IN THE LATE
MORNING AND THEN FALLING THROUGH THE AFTERNOON AS COLDER AIR WRAPS
BACK AROUND EXITING LOW. THIS WILL LEAD TO A CHANGE BACK TO SNOW
FROM NORTH TO SOUTH WITH SOME TRANSITORY SLEET MIXING IN AS WELL.
EXPECT SNOW AMOUNTS AROUND AN INCH AT MOST WITH THE HIGHEST AMOUNTS
IN OUR FAR NORTHEAST. ANY ACCUMULATION OF FREEZING RAIN AT THE ONSET
WILL BE LESS THAN A TENTH OF AN INCH. SOME LIGHT LAKE EFFECT/
ENHANCED SNOW POSSIBLE THURSDAY NIGHT BUT BY AND LARGE EVENT WILL BE
WINDING DOWN BY THEN.
NEXT CHANCE OF SNOW LOOKS TO BE ON SUNDAY AS ELONGATED/POSITIVELY
TILTED TROUGH SWINGS THROUGH THE CENTRAL CONUS. MODELS HAVE SHOWN A
HIGH DEGREE OF VARIABILITY DURING THIS TIMEFRAME SO FORECAST
CONFIDENCE IS LOW. DID FOCUS THE POP FORECAST A BIT BUT WILL HOLD
OFF FOR A FEW MORE RUNS BEFORE LATCHING ONTO ANY SPECIFICS. STILL
LOOKS LIKE AT LEAST A GLANCING BLOW OF MUCH COLDER AIR BEHIND THIS
SYSTEM ON MONDAY. NUDGED THE FORECAST TOWARD COLDER RAW GUIDANCE
WITH HIGHS IN THE TEENS AND LOWS FLIRTING WITH 0F.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1235 PM EST TUE JAN 27 2015
VFR WITH LIGHT WINDS EXPECTED THROUGH THE TAF CYCLE. MAY SEE A
SCT CU DECK NEAR 3 KFT MATERIALIZE FOR A BRIEF TIME THIS AFTERNOON
AS MOISTURE STREAMS OFF OF LAKE HURON UNDER A STRENGTHENING
SUBSIDENCE INVERSION. OTHERWISE ANTICIPATE SOME MID-HIGH LEVEL
CLOUDINESS...ESPECIALLY BY TOMORROW AS WAA ENSUES.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...BENTLEY
SHORT TERM...LASHLEY
LONG TERM...AGD
AVIATION...STEINWEDEL
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
830 AM EST TUE JAN 27 2015
.SYNOPSIS...
ISSUED AT 828 AM EST TUE JAN 27 2015
SKIES WILL CLEAR TODAY WITH TEMPERATURES WARMING INTO THE MID TO
UPPER 20S. TEMPERATURES WILL RISE TO NEAR FREEZING ON WEDNESDAY
WITH PARTLY CLOUDY SKIES. THE NEXT CHANCE OF PRECIPITATION WILL
ARRIVE WEDNESDAY NIGHT AND THURSDAY WITH A WINTRY MIX EXPECTED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 403 AM EST TUE JAN 27 2015
ANOTHER RELATIVELY QUIET SHORT TERM BUT CLOUD CONCERNS AND POSSIBLE
FZDZ THIS MORNING MAKE FOR A FEW ISSUES. FAR WESTERN CWA SATURATED
OVERNIGHT WITH FLURRIES OR VERY LIGHT SNOW FALLING IN DOWNSHEAR SIDE
OF MID LEVEL JET AXIS. ADVISORY ISSUED LAST EVENING FOR FREEZING
DRIZZLE THAT NEVER REALLY MATERIALIZED OVER OUR AREA DUE TO
SATURATED DGZ AND SEEDER FEEDER MECHANISMS ALLOWING FOR SNOW CRYSTAL
GROWTH. HOWEVER...STILL A SLIGHT CONCERN FOR LIGHT FZDZ THROUGH
SUNRISE AS SATELLITE SHOWS WARMING CLOUD TOPS UPSTREAM ACROSS WI
MOVING QUICKLY SOUTH AND LOSS OF HIGHER SEED CLOUDS EXPECTED NEXT
FEW HOURS. HIRES MODEL SOUNDINGS INDEED SHOWING DGZ DRYING OUT EARLY
THIS MORNING IN THE WEST BUT LOW LEVELS ALSO DRYING. THUS CHANCES
FOR ANY PCPN WILL BE DIMINISHING BUT PCPN TYPE OF ANY RESIDUAL PCPN
COULD BE FZDZ. CALLS TO WHITE AND PULASKI COUNTY INDICATE NO
PROBLEMS FROM FZDZ OVERNIGHT AND LITTLE TO NO REPORTS OF FZDZ
UPSTREAM AT THIS HOUR. WITH ADVISORY SET TO EXPIRE AT 6AM ANYWAY
PLAN TO CANCEL EARLY AND HANDLE ANY SPOTTY FREEZING LIQUID
DEVELOPMENT WITH SPECIAL WEATHER STATEMENTS IF NEEDED.
DRY WEDGE IN LOWER LEVELS HAS REMAINED IN PLACE ACROSS REMAINDER OF
CWA WITH LIGHT EASTERLY FLOW AIDING IN DRY AIR ENTRAINMENT. THIS DRY
EASTERLY FLOW ALONG WITH SUBSIDENCE TODAY EXPECTED TO HELP BREAK UP
CLOUDS FROM NORTHEAST TO SOUTHWEST THROUGH THE DAY.
HOWEVER...SATELLITE SHOWS AREA OF STRATUS OVER WI MOVING SLOWLY
SOUTHWARD AND MODELS DO NOT HAVE A GOOD HANDLE ON THIS CLOUD COVER.
LOW LEVEL RH PROGS FROM VARIOUS MODELS ALL SEEM TO SUPPORT DRYING
TODAY FROM THE NORTHEAST BUT RUC13 HAS ALSO SHOWN A TENDENCY FOR
HIGHER RH ACROSS CENTRAL OH TO ADVECT WEST INTO OUR EASTERN AREA
THIS AFTERNOON. ALL THESE CLOUD ISSUES MAKE FOR DIFFICULT FORECAST
TODAY. MOST SURROUNDING OFFICES FAVORING THE CLEARING SCENARIO SO
WILL LEAN TOWARD THE DRYING AND BE OPTIMISTIC WITH SKIES BECOMING
PARTLY CLOUDY AND EVENTUALLY MOSTLY CLEAR TONIGHT. HIGH PRESSURE TO
THEN SLIDE ACROSS THE AREA TONIGHT WITH LIGHT WINDS AND MOSTLY CLEAR
SKIES. THIS SHOULD ALLOW GOOD RADIATIONAL COOLING AND TEMPS TO DROP
BACK TO SINGLE DIGITS EASTERN HALF AND LOWER TEENS WEST WHERE SOME
MID AND HIGH CLOUDS MAY SPILL OVER RIDGE.
&&
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 403 AM EST TUE JAN 27 2015
NEXT CLIPPER-TYPE SYSTEM STILL SLATED TO IMPACT THE AREA LATE
WEDNESDAY NIGHT INTO THURSDAY. THIS WAVE WILL ACTUALLY BE AIDED TO
SOME DEGREE BY ANOTHER VORT MAX LEFTOVER FROM OLD BAJA CUTOFF LOW
CURRENTLY BEING REABSORBED INTO THE MEAN WESTERLIES. STILL SOME
INCONSISTENCIES IN THE MODELS REGARDING WHERE EXACTLY THESE TWO
WAVES TRACK AND HOW THEY INTERACT BUT OUR AREA SHOULD SEE A PERIOD
OF DECENT PV ADVECTION/CVA THAT WILL GENERATE AT LEAST SOME FORCED
ASCENT AND LIGHT PRECIP. THE PROBLEM IS THAT UPPER JET SUPPORT IS
MARGINAL AT BEST AND LATEST CONSENSUS TRACK FORECAST KEEPS THE BEST
LOW LEVEL ISENTROPIC ASCENT AND FRONTOGENESIS GENERALLY NORTH OF OUR
AREA. FURTHERMORE...STRONG LOW LEVEL WAA WILL INTRODUCE A MELTING
LAYER ALOFT (AND EVENTUALLY AT THE SURFACE) THAT WILL MAKE
ACCUMULATING SNOW VERY DIFFICULT WITH A HODGEPODGE OF ALL DIFFERENT
PRECIP TYPES OVER SPACE AND TIME. IMPOSSIBLE TO CORRECTLY NAIL DOWN
EXACT TIMING AND LOCATION OF VARIOUS PRECIP TYPES THIS FAR OUT BUT
DID TRY TO PUT A "BEST GUESS" IN THE GRIDS FOR NOW...BASED ON
CONSENSUS OF FORECAST LOW TRACK AND THERMAL PROFILES. PREFERENCE
LIES WITH A GFS/ECMWF COMBO. NAM SURFACE TEMPS APPEAR TOO COLD AND
QPF AMOUNTS TOO LIGHT. GEM THERMAL PROFILES ARE DECENT BUT KEEPS
PRECIP LOCKED UP TOO FAR NORTH. SUPPOSE THIS IS POSSIBLE IF FORECAST
TRACK IS IN LARGE ERROR BUT SOLUTIONS HAVE BEEN FAIRLY STABLE THUS
FAR AND SUSPECT MOST AREAS WILL SEE AT LEAST SOME LIGHT PRECIP WITH
A MODEST PV ANOMALY PASSING DIRECTLY OVERHEAD. THIS IS ESPECIALLY
TRUE GIVEN SUPERB MOISTURE AVAILABILITY WITH 700MB MIXING RATIOS
OVER 4 G/KG AND PW VALUES AROUND 0.75 INCHES. AS FAR AS PRECIP
TYPES...EXPECT COLD SURFACE TEMPS TO SUPPORT FREEZING RAIN AT THE
ONSET...TRANSITIONING TO ALL RAIN FROM SOUTH TO NORTH EARLY THURSDAY
MORNING. LATENT HEAT RELEASE DUE TO FREEZING AND CONTINUAL WAA WITH
S/SW SURFACE WINDS SHOULD LEAD TO A NONDIURNAL TEMPERATURE TREND AND
A FAIRLY QUICK CHANGEOVER TO RAIN WITH MINIMAL ICE ACCUMULATION.
STILL COULD BE SOME SLICK ROADS DURING THE EARLY MORNING COMMUTE
THOUGH...ESPECIALLY NORTH OF US-30. ATYPICAL DIURNAL TEMP TREND
CONTINUES ON THURSDAY WITH HIGHS PROBABLY OCCURRING IN THE LATE
MORNING AND THEN FALLING THROUGH THE AFTERNOON AS COLDER AIR WRAPS
BACK AROUND EXITING LOW. THIS WILL LEAD TO A CHANGE BACK TO SNOW
FROM NORTH TO SOUTH WITH SOME TRANSITORY SLEET MIXING IN AS WELL.
EXPECT SNOW AMOUNTS AROUND AN INCH AT MOST WITH THE HIGHEST AMOUNTS
IN OUR FAR NORTHEAST. ANY ACCUMULATION OF FREEZING RAIN AT THE ONSET
WILL BE LESS THAN A TENTH OF AN INCH. SOME LIGHT LAKE EFFECT/
ENHANCED SNOW POSSIBLE THURSDAY NIGHT BUT BY AND LARGE EVENT WILL BE
WINDING DOWN BY THEN.
NEXT CHANCE OF SNOW LOOKS TO BE ON SUNDAY AS ELONGATED/POSITIVELY
TILTED TROUGH SWINGS THROUGH THE CENTRAL CONUS. MODELS HAVE SHOWN A
HIGH DEGREE OF VARIABILITY DURING THIS TIMEFRAME SO FORECAST
CONFIDENCE IS LOW. DID FOCUS THE POP FORECAST A BIT BUT WILL HOLD
OFF FOR A FEW MORE RUNS BEFORE LATCHING ONTO ANY SPECIFICS. STILL
LOOKS LIKE AT LEAST A GLANCING BLOW OF MUCH COLDER AIR BEHIND THIS
SYSTEM ON MONDAY. NUDGED THE FORECAST TOWARD COLDER RAW GUIDANCE
WITH HIGHS IN THE TEENS AND LOWS FLIRTING WITH 0F.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 625 AM EST TUE JAN 27 2015
LOW LEVEL EASTERLY FLOW HAS HELPED PUSH MVFR CIGS BACK EAST OF
KSBN SO TAF SITES NOW VFR. SATELLITE SHOWS MVFR AND IFR STILL
NORTH AND WEST OF AREA BUT TRAJECTORIES SUGGEST THESE WILL STAY
WEST OF TERMINALS. SATELLITE ALSO SHOWING CLEARING BEGINNING TO
WORK SOUTH THROUGH WESTERN MICHIGAN SO STAYED OPTIMISTIC WITH
CLEARING THIS MORNING AND VFR THROUGH THE PERIOD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...BENTLEY
SHORT TERM...LASHLEY
LONG TERM...AGD
AVIATION...LASHLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
628 AM EST TUE JAN 27 2015
.SYNOPSIS...
ISSUED AT 410 AM EST TUE JAN 27 2015
SOME VERY LIGHT SNOW OR LIGHT FREEZING DRIZZLE WILL BE POSSIBLE
EARLY THIS MORNING ACROSS FAR WESTERN AND NORTHWESTERN INDIANA AS
WELL AS ILLINOIS. ANY PRECIPITATION IS EXPECTED TO DIMINISH
SHORTLY AFTER SUNRISE. HIGHS TODAY WILL BE IN THE UPPER 20S AND
30S WITH PARTLY TO MOSTLY CLOUDY SKIES.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 403 AM EST TUE JAN 27 2015
ANOTHER RELATIVELY QUIET SHORT TERM BUT CLOUD CONCERNS AND POSSIBLE
FZDZ THIS MORNING MAKE FOR A FEW ISSUES. FAR WESTERN CWA SATURATED
OVERNIGHT WITH FLURRIES OR VERY LIGHT SNOW FALLING IN DOWNSHEAR SIDE
OF MID LEVEL JET AXIS. ADVISORY ISSUED LAST EVENING FOR FREEZING
DRIZZLE THAT NEVER REALLY MATERIALIZED OVER OUR AREA DUE TO
SATURATED DGZ AND SEEDER FEEDER MECHANISMS ALLOWING FOR SNOW CRYSTAL
GROWTH. HOWEVER...STILL A SLIGHT CONCERN FOR LIGHT FZDZ THROUGH
SUNRISE AS SATELLITE SHOWS WARMING CLOUD TOPS UPSTREAM ACROSS WI
MOVING QUICKLY SOUTH AND LOSS OF HIGHER SEED CLOUDS EXPECTED NEXT
FEW HOURS. HIRES MODEL SOUNDINGS INDEED SHOWING DGZ DRYING OUT EARLY
THIS MORNING IN THE WEST BUT LOW LEVELS ALSO DRYING. THUS CHANCES
FOR ANY PCPN WILL BE DIMINISHING BUT PCPN TYPE OF ANY RESIDUAL PCPN
COULD BE FZDZ. CALLS TO WHITE AND PULASKI COUNTY INDICATE NO
PROBLEMS FROM FZDZ OVERNIGHT AND LITTLE TO NO REPORTS OF FZDZ
UPSTREAM AT THIS HOUR. WITH ADVISORY SET TO EXPIRE AT 6AM ANYWAY
PLAN TO CANCEL EARLY AND HANDLE ANY SPOTTY FREEZING LIQUID
DEVELOPMENT WITH SPECIAL WEATHER STATEMENTS IF NEEDED.
DRY WEDGE IN LOWER LEVELS HAS REMAINED IN PLACE ACROSS REMAINDER OF
CWA WITH LIGHT EASTERLY FLOW AIDING IN DRY AIR ENTRAINMENT. THIS DRY
EASTERLY FLOW ALONG WITH SUBSIDENCE TODAY EXPECTED TO HELP BREAK UP
CLOUDS FROM NORTHEAST TO SOUTHWEST THROUGH THE DAY.
HOWEVER...SATELLITE SHOWS AREA OF STRATUS OVER WI MOVING SLOWLY
SOUTHWARD AND MODELS DO NOT HAVE A GOOD HANDLE ON THIS CLOUD COVER.
LOW LEVEL RH PROGS FROM VARIOUS MODELS ALL SEEM TO SUPPORT DRYING
TODAY FROM THE NORTHEAST BUT RUC13 HAS ALSO SHOWN A TENDENCY FOR
HIGHER RH ACROSS CENTRAL OH TO ADVECT WEST INTO OUR EASTERN AREA
THIS AFTERNOON. ALL THESE CLOUD ISSUES MAKE FOR DIFFICULT FORECAST
TODAY. MOST SURROUNDING OFFICES FAVORING THE CLEARING SCENARIO SO
WILL LEAN TOWARD THE DRYING AND BE OPTIMISTIC WITH SKIES BECOMING
PARTLY CLOUDY AND EVENTUALLY MOSTLY CLEAR TONIGHT. HIGH PRESSURE TO
THEN SLIDE ACROSS THE AREA TONIGHT WITH LIGHT WINDS AND MOSTLY CLEAR
SKIES. THIS SHOULD ALLOW GOOD RADIATIONAL COOLING AND TEMPS TO DROP
BACK TO SINGLE DIGITS EASTERN HALF AND LOWER TEENS WEST WHERE SOME
MID AND HIGH CLOUDS MAY SPILL OVER RIDGE.
&&
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 403 AM EST TUE JAN 27 2015
NEXT CLIPPER-TYPE SYSTEM STILL SLATED TO IMPACT THE AREA LATE
WEDNESDAY NIGHT INTO THURSDAY. THIS WAVE WILL ACTUALLY BE AIDED TO
SOME DEGREE BY ANOTHER VORT MAX LEFTOVER FROM OLD BAJA CUTOFF LOW
CURRENTLY BEING REABSORBED INTO THE MEAN WESTERLIES. STILL SOME
INCONSISTENCIES IN THE MODELS REGARDING WHERE EXACTLY THESE TWO
WAVES TRACK AND HOW THEY INTERACT BUT OUR AREA SHOULD SEE A PERIOD
OF DECENT PV ADVECTION/CVA THAT WILL GENERATE AT LEAST SOME FORCED
ASCENT AND LIGHT PRECIP. THE PROBLEM IS THAT UPPER JET SUPPORT IS
MARGINAL AT BEST AND LATEST CONSENSUS TRACK FORECAST KEEPS THE BEST
LOW LEVEL ISENTROPIC ASCENT AND FRONTOGENESIS GENERALLY NORTH OF OUR
AREA. FURTHERMORE...STRONG LOW LEVEL WAA WILL INTRODUCE A MELTING
LAYER ALOFT (AND EVENTUALLY AT THE SURFACE) THAT WILL MAKE
ACCUMULATING SNOW VERY DIFFICULT WITH A HODGEPODGE OF ALL DIFFERENT
PRECIP TYPES OVER SPACE AND TIME. IMPOSSIBLE TO CORRECTLY NAIL DOWN
EXACT TIMING AND LOCATION OF VARIOUS PRECIP TYPES THIS FAR OUT BUT
DID TRY TO PUT A "BEST GUESS" IN THE GRIDS FOR NOW...BASED ON
CONSENSUS OF FORECAST LOW TRACK AND THERMAL PROFILES. PREFERENCE
LIES WITH A GFS/ECMWF COMBO. NAM SURFACE TEMPS APPEAR TOO COLD AND
QPF AMOUNTS TOO LIGHT. GEM THERMAL PROFILES ARE DECENT BUT KEEPS
PRECIP LOCKED UP TOO FAR NORTH. SUPPOSE THIS IS POSSIBLE IF FORECAST
TRACK IS IN LARGE ERROR BUT SOLUTIONS HAVE BEEN FAIRLY STABLE THUS
FAR AND SUSPECT MOST AREAS WILL SEE AT LEAST SOME LIGHT PRECIP WITH
A MODEST PV ANOMALY PASSING DIRECTLY OVERHEAD. THIS IS ESPECIALLY
TRUE GIVEN SUPERB MOISTURE AVAILABILITY WITH 700MB MIXING RATIOS
OVER 4 G/KG AND PW VALUES AROUND 0.75 INCHES. AS FAR AS PRECIP
TYPES...EXPECT COLD SURFACE TEMPS TO SUPPORT FREEZING RAIN AT THE
ONSET...TRANSITIONING TO ALL RAIN FROM SOUTH TO NORTH EARLY THURSDAY
MORNING. LATENT HEAT RELEASE DUE TO FREEZING AND CONTINUAL WAA WITH
S/SW SURFACE WINDS SHOULD LEAD TO A NONDIURNAL TEMPERATURE TREND AND
A FAIRLY QUICK CHANGEOVER TO RAIN WITH MINIMAL ICE ACCUMULATION.
STILL COULD BE SOME SLICK ROADS DURING THE EARLY MORNING COMMUTE
THOUGH...ESPECIALLY NORTH OF US-30. ATYPICAL DIURNAL TEMP TREND
CONTINUES ON THURSDAY WITH HIGHS PROBABLY OCCURRING IN THE LATE
MORNING AND THEN FALLING THROUGH THE AFTERNOON AS COLDER AIR WRAPS
BACK AROUND EXITING LOW. THIS WILL LEAD TO A CHANGE BACK TO SNOW
FROM NORTH TO SOUTH WITH SOME TRANSITORY SLEET MIXING IN AS WELL.
EXPECT SNOW AMOUNTS AROUND AN INCH AT MOST WITH THE HIGHEST AMOUNTS
IN OUR FAR NORTHEAST. ANY ACCUMULATION OF FREEZING RAIN AT THE ONSET
WILL BE LESS THAN A TENTH OF AN INCH. SOME LIGHT LAKE EFFECT/
ENHANCED SNOW POSSIBLE THURSDAY NIGHT BUT BY AND LARGE EVENT WILL BE
WINDING DOWN BY THEN.
NEXT CHANCE OF SNOW LOOKS TO BE ON SUNDAY AS ELONGATED/POSITIVELY
TILTED TROUGH SWINGS THROUGH THE CENTRAL CONUS. MODELS HAVE SHOWN A
HIGH DEGREE OF VARIABILITY DURING THIS TIMEFRAME SO FORECAST
CONFIDENCE IS LOW. DID FOCUS THE POP FORECAST A BIT BUT WILL HOLD
OFF FOR A FEW MORE RUNS BEFORE LATCHING ONTO ANY SPECIFICS. STILL
LOOKS LIKE AT LEAST A GLANCING BLOW OF MUCH COLDER AIR BEHIND THIS
SYSTEM ON MONDAY. NUDGED THE FORECAST TOWARD COLDER RAW GUIDANCE
WITH HIGHS IN THE TEENS AND LOWS FLIRTING WITH 0F.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 625 AM EST TUE JAN 27 2015
LOW LEVEL EASTERLY FLOW HAS HELPED PUSH MVFR CIGS BACK EAST OF
KSBN SO TAF SITES NOW VFR. SATELLITE SHOWS MVFR AND IFR STILL
NORTH AND WEST OF AREA BUT TRAJECTORIES SUGGEST THESE WILL STAY
WEST OF TERMINALS. SATELLITE ALSO SHOWING CLEARING BEGINNING TO
WORK SOUTH THROUGH WESTERN MICHIGAN SO STAYED OPTIMISTIC WITH
CLEARING THIS MORNING AND VFR THROUGH THE PERIOD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...AGD
AVIATION...LASHLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
412 AM EST TUE JAN 27 2015
.SYNOPSIS...
ISSUED AT 410 AM EST TUE JAN 27 2015
SOME VERY LIGHT SNOW OR LIGHT FREEZING DRIZZLE WILL BE POSSIBLE
EARLY THIS MORNING ACROSS FAR WESTERN AND NORTHWESTERN INDIANA AS
WELL AS ILLINOIS. ANY PRECIPITATION IS EXPECTED TO DIMINISH
SHORTLY AFTER SUNRISE. HIGHS TODAY WILL BE IN THE UPPER 20S AND
30S WITH PARTLY TO MOSTLY CLOUDY SKIES.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 403 AM EST TUE JAN 27 2015
ANOTHER RELATIVELY QUIET SHORT TERM BUT CLOUD CONCERNS AND POSSIBLE
FZDZ THIS MORNING MAKE FOR A FEW ISSUES. FAR WESTERN CWA SATURATED
OVERNIGHT WITH FLURRIES OR VERY LIGHT SNOW FALLING IN DOWNSHEAR SIDE
OF MID LEVEL JET AXIS. ADVISORY ISSUED LAST EVENING FOR FREEZING
DRIZZLE THAT NEVER REALLY MATERIALIZED OVER OUR AREA DUE TO
SATURATED DGZ AND SEEDER FEEDER MECHANISMS ALLOWING FOR SNOW CRYSTAL
GROWTH. HOWEVER...STILL A SLIGHT CONCERN FOR LIGHT FZDZ THROUGH
SUNRISE AS SATELLITE SHOWS WARMING CLOUD TOPS UPSTREAM ACROSS WI
MOVING QUICKLY SOUTH AND LOSS OF HIGHER SEED CLOUDS EXPECTED NEXT
FEW HOURS. HIRES MODEL SOUNDINGS INDEED SHOWING DGZ DRYING OUT EARLY
THIS MORNING IN THE WEST BUT LOW LEVELS ALSO DRYING. THUS CHANCES
FOR ANY PCPN WILL BE DIMINISHING BUT PCPN TYPE OF ANY RESIDUAL PCPN
COULD BE FZDZ. CALLS TO WHITE AND PULASKI COUNTY INDICATE NO
PROBLEMS FROM FZDZ OVERNIGHT AND LITTLE TO NO REPORTS OF FZDZ
UPSTREAM AT THIS HOUR. WITH ADVISORY SET TO EXPIRE AT 6AM ANYWAY
PLAN TO CANCEL EARLY AND HANDLE ANY SPOTTY FREEZING LIQUID
DEVELOPMENT WITH SPECIAL WEATHER STATEMENTS IF NEEDED.
DRY WEDGE IN LOWER LEVELS HAS REMAINED IN PLACE ACROSS REMAINDER OF
CWA WITH LIGHT EASTERLY FLOW AIDING IN DRY AIR ENTRAINMENT. THIS DRY
EASTERLY FLOW ALONG WITH SUBSIDENCE TODAY EXPECTED TO HELP BREAK UP
CLOUDS FROM NORTHEAST TO SOUTHWEST THROUGH THE DAY.
HOWEVER...SATELLITE SHOWS AREA OF STRATUS OVER WI MOVING SLOWLY
SOUTHWARD AND MODELS DO NOT HAVE A GOOD HANDLE ON THIS CLOUD COVER.
LOW LEVEL RH PROGS FROM VARIOUS MODELS ALL SEEM TO SUPPORT DRYING
TODAY FROM THE NORTHEAST BUT RUC13 HAS ALSO SHOWN A TENDENCY FOR
HIGHER RH ACROSS CENTRAL OH TO ADVECT WEST INTO OUR EASTERN AREA
THIS AFTERNOON. ALL THESE CLOUD ISSUES MAKE FOR DIFFICULT FORECAST
TODAY. MOST SURROUNDING OFFICES FAVORING THE CLEARING SCENARIO SO
WILL LEAN TOWARD THE DRYING AND BE OPTIMISTIC WITH SKIES BECOMING
PARTLY CLOUDY AND EVENTUALLY MOSTLY CLEAR TONIGHT. HIGH PRESSURE TO
THEN SLIDE ACROSS THE AREA TONIGHT WITH LIGHT WINDS AND MOSTLY CLEAR
SKIES. THIS SHOULD ALLOW GOOD RADIATIONAL COOLING AND TEMPS TO DROP
BACK TO SINGLE DIGITS EASTERN HALF AND LOWER TEENS WEST WHERE SOME
MID AND HIGH CLOUDS MAY SPILL OVER RIDGE.
&&
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 403 AM EST TUE JAN 27 2015
NEXT CLIPPER-TYPE SYSTEM STILL SLATED TO IMPACT THE AREA LATE
WEDNESDAY NIGHT INTO THURSDAY. THIS WAVE WILL ACTUALLY BE AIDED TO
SOME DEGREE BY ANOTHER VORT MAX LEFTOVER FROM OLD BAJA CUTOFF LOW
CURRENTLY BEING REABSORBED INTO THE MEAN WESTERLIES. STILL SOME
INCONSISTENCIES IN THE MODELS REGARDING WHERE EXACTLY THESE TWO
WAVES TRACK AND HOW THEY INTERACT BUT OUR AREA SHOULD SEE A PERIOD
OF DECENT PV ADVECTION/CVA THAT WILL GENERATE AT LEAST SOME FORCED
ASCENT AND LIGHT PRECIP. THE PROBLEM IS THAT UPPER JET SUPPORT IS
MARGINAL AT BEST AND LATEST CONSENSUS TRACK FORECAST KEEPS THE BEST
LOW LEVEL ISENTROPIC ASCENT AND FRONTOGENESIS GENERALLY NORTH OF OUR
AREA. FURTHERMORE...STRONG LOW LEVEL WAA WILL INTRODUCE A MELTING
LAYER ALOFT (AND EVENTUALLY AT THE SURFACE) THAT WILL MAKE
ACCUMULATING SNOW VERY DIFFICULT WITH A HODGEPODGE OF ALL DIFFERENT
PRECIP TYPES OVER SPACE AND TIME. IMPOSSIBLE TO CORRECTLY NAIL DOWN
EXACT TIMING AND LOCATION OF VARIOUS PRECIP TYPES THIS FAR OUT BUT
DID TRY TO PUT A "BEST GUESS" IN THE GRIDS FOR NOW...BASED ON
CONSENSUS OF FORECAST LOW TRACK AND THERMAL PROFILES. PREFERENCE
LIES WITH A GFS/ECMWF COMBO. NAM SURFACE TEMPS APPEAR TOO COLD AND
QPF AMOUNTS TOO LIGHT. GEM THERMAL PROFILES ARE DECENT BUT KEEPS
PRECIP LOCKED UP TOO FAR NORTH. SUPPOSE THIS IS POSSIBLE IF FORECAST
TRACK IS IN LARGE ERROR BUT SOLUTIONS HAVE BEEN FAIRLY STABLE THUS
FAR AND SUSPECT MOST AREAS WILL SEE AT LEAST SOME LIGHT PRECIP WITH
A MODEST PV ANOMALY PASSING DIRECTLY OVERHEAD. THIS IS ESPECIALLY
TRUE GIVEN SUPERB MOISTURE AVAILABILITY WITH 700MB MIXING RATIOS
OVER 4 G/KG AND PW VALUES AROUND 0.75 INCHES. AS FAR AS PRECIP
TYPES...EXPECT COLD SURFACE TEMPS TO SUPPORT FREEZING RAIN AT THE
ONSET...TRANSITIONING TO ALL RAIN FROM SOUTH TO NORTH EARLY THURSDAY
MORNING. LATENT HEAT RELEASE DUE TO FREEZING AND CONTINUAL WAA WITH
S/SW SURFACE WINDS SHOULD LEAD TO A NONDIURNAL TEMPERATURE TREND AND
A FAIRLY QUICK CHANGEOVER TO RAIN WITH MINIMAL ICE ACCUMULATION.
STILL COULD BE SOME SLICK ROADS DURING THE EARLY MORNING COMMUTE
THOUGH...ESPECIALLY NORTH OF US-30. ATYPICAL DIURNAL TEMP TREND
CONTINUES ON THURSDAY WITH HIGHS PROBABLY OCCURRING IN THE LATE
MORNING AND THEN FALLING THROUGH THE AFTERNOON AS COLDER AIR WRAPS
BACK AROUND EXITING LOW. THIS WILL LEAD TO A CHANGE BACK TO SNOW
FROM NORTH TO SOUTH WITH SOME TRANSITORY SLEET MIXING IN AS WELL.
EXPECT SNOW AMOUNTS AROUND AN INCH AT MOST WITH THE HIGHEST AMOUNTS
IN OUR FAR NORTHEAST. ANY ACCUMULATION OF FREEZING RAIN AT THE ONSET
WILL BE LESS THAN A TENTH OF AN INCH. SOME LIGHT LAKE EFFECT/
ENHANCED SNOW POSSIBLE THURSDAY NIGHT BUT BY AND LARGE EVENT WILL BE
WINDING DOWN BY THEN.
NEXT CHANCE OF SNOW LOOKS TO BE ON SUNDAY AS ELONGATED/POSITIVELY
TILTED TROUGH SWINGS THROUGH THE CENTRAL CONUS. MODELS HAVE SHOWN A
HIGH DEGREE OF VARIABILITY DURING THIS TIMEFRAME SO FORECAST
CONFIDENCE IS LOW. DID FOCUS THE POP FORECAST A BIT BUT WILL HOLD
OFF FOR A FEW MORE RUNS BEFORE LATCHING ONTO ANY SPECIFICS. STILL
LOOKS LIKE AT LEAST A GLANCING BLOW OF MUCH COLDER AIR BEHIND THIS
SYSTEM ON MONDAY. NUDGED THE FORECAST TOWARD COLDER RAW GUIDANCE
WITH HIGHS IN THE TEENS AND LOWS FLIRTING WITH 0F.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1237 AM EST TUE JAN 27 2015
ANOTHER TRICKY AVIATION FORECAST WITH RESPECT TO CLOUD HEIGHTS
THIS PERIOD. TERMINALS REMAIN VFR AT ISSUANCE BUT MVFR AND IFR
CONDITIONS EXISTS JUST WEST OF KSBN. KMCY AND KOXI HAVE DROPPED
TO 25HFT WHILE KVPZ DOWN TO 1KFT WITH SOME LIGHT SNOW AT TIMES.
LOW LEVEL FLOW BEING SHOWN BY HIRES GUIDANCE TO SLOWLY TURN
NORTHEAST AND INCREASE SLIGHTLY TO AROUND 5-8 KNOTS NEXT FEW
HOURS. THIS SHOULD SLOW OR END THE EASTWARD EXPANSION OF MVFR CIGS
AND EVENTUALLY PUSH THEM SOUTHWEST. HOWEVER...WITH PROXIMITY TO
KSBN HAD TO ADD A FEW HOURS OF TEMPO MVFR TO ACCOUNT FOR
POSSIBILITY OF THESE CLOUDS. NORTHEAST FLOW SHOULD EVENTUALLY
ALLOW SLIGHTLY DRIER LOW LEVEL AIR TO WORK WEST WITH VFR
CONDITIONS INTO TUESDAY. NEXT CONCERN IS LOW LEVEL CLOUDS OVER
CENTRAL OHIO MAKING A RUN WEST AS THIS LOW LEVEL FLOW CHANGES. RUC
MODEL BRINGS HIGHER RH INTO KFWA TUESDAY MORNING. HAVE INTRODUCED
A SCATTERED DECK AT 25HFT FOR NOW BUT THIS WILL BE MONITORED FOR
POSSIBLE ADDITION OF MVFR CIGS TO LATER FORECASTS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...AGD
AVIATION...LASHLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
300 AM EST TUE JAN 27 2015
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 152 PM EST MON JAN 26 2015
A QUICK MOVING WEATHER DISTURBANCE WILL PUSH ACROSS ILLINOIS AND
INDIANA THIS EVENING...BRINGING CHANCES FOR SOME LIGHT SNOW THIS
EVENING TO WESTERN PARTS OF CENTRAL INDIANA.
COLD HIGH PRESSURE IS EXPECTED TO ARRIVE ON TUESDAY AND CONTINUE
TO REMAIN IN THE AREA THROUGH WEDNESDAY NIGHT. THIS WILL RESULT IN
DRY WEATHER WITH BELOW NORMAL TEMPERATURES. ANOTHER QUICK MOVING
AREA OF LOW PRESSURE IS EXPECTED TO ARRIVE AND PASS ACROSS CENTRAL
INDIANA ON EARLY THURSDAY MORNING...ONCE AGAIN RESULTING IN CHANCES
FOR PRECIPITATION.
ANOTHER WEAK LOW PRESSURE SYSTEM IS EXPECTED TO PUSH ACROSS THE
REGION THIS WEEKEND...ONCE AGAIN RESULTING IN CHANCES FOR
PRECIPITATION.
&&
.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 1039 PM EST MON JAN 26 2015
UPDATE...
INSERTED MENTION OF PATCHY FREEZING DRIZZLE ACROSS THE WESTERN
PORTIONS OF CENTRAL INDIANA. FREEZING DRIZZLE HAS BEEN REPORTED
UPSTREAM. CONTINUED TO LEAVE FAR NORTHEAST COUNTIES DRY EXCEPT FOR
A FEW FLURRIES. UPDATED GRIDS HAVE BEEN SENT.
PREVIOUS DISCUSSION...
MAIN FORECAST CHALLENGE WILL BE PRECIP THIS EVENING. GFS SUGGESTS
THE UPPER WAVE RESPONSIBLE FOR THE ONGOING SNOW OVER ILLINOIS WILL
CONTINUE TO DIVE SSE AMID THE QUICK FLOW ALOFT. HRRR SHOW PRECIP
MAINLY CONTAINED TO THE WESTERN PARTS OF THE FORECAST AREA. TIME
HEIGHTS THIS EVENING SHOW BEST SATURATION IN THE WESTERN AND
SOUTHERN PARTS OF THE FORECAST AREA...WITH LESS MOISTURE AVAILABLE
ACROSS THE NORTHEAST. ISENTROPIC SURFACE SHOWS LITTLE TO NO HELP
AS THIS SYSTEM PASSES. FORECAST SOUNDINGS ACROSS WESTERN INDIANA
CONTINUE TO SHOW GOOD LOW AND MID LEVEL SATURATION THROUGH THE
NIGHT.
THUS WILL RAISE POPS...PARTICULARLY ACROSS THE WESTERN PARTS OF
THE FORECAST AREA...TRENDING TOWARD A FLURRY OR DRY FORECAST ACROSS
THE FAR NORTHEAST. AS FOR TEMPS...CLOUDS ARE EXPECTED THROUGH MUCH
OF THE NIGHT AS THE UPPER WAVE PASSES AND TEMPERATURE ADVECTION IS
NEUTRAL. THUS WILL STICK CLOSE TO A BLEND ON TEMPS.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
ISSUED AT 152 PM EST MON JAN 26 2015
MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE TEMPS INITIALLY
FOLLOWED BY PRECIPITATION CHANCES ON THURSDAY.
DRY AND COLD WEATHER IS EXPECTED THROUGH WEDNESDAY DUE TO THE
FOLLOWING REASONS:
SURFACE HIGH PRESSURE BUILDING OUT OF CANADA WILL BUILD ACROSS AND
PASS OVER CENTRAL INDIANA THROUGH WEDNESDAY NIGHT. TIME HEIGHT
SECTIONS THROUGH WEDNESDAY NIGHT CONTINUE TO SHOW A DRY COLUMN
AMID SUBSIDENCE. FORECAST SOUNDINGS AGREE...ONLY SHOWING SOME
SATURATION NEAR 12Z THURSDAY. MEANWHILE ALOFT...A DEEP TROUGH OVER
EASTERN 1/2 OF THE UNITED STATES WILL CONTINUE TO PROVIDE A VERY
COLD AND NW FLOW TO CENTRAL INDIANA. THIS WILL HELP IN RESULTING
IN BELOW NORMAL TEMPERATURES. THUS WITH ONLY A FEW QUICK PASSING
HIGH CLOUDS EXPECTED...WILL TREND TOWARD PARTLY CLOUDY ON TUESDAY
THROUGH WEDNESDAY EVENING...ALONG WITH A BLEND ON TEMPS.
ON LATE WEDNESDAY NIGHT THE GFS INDICATES A WELL ORGANIZED SHORT
WAVE ALOFT PUSHING INTO INDIANA FROM THE WEST. ONCE
AGAIN...FORECAST SOUNDINGS HINT AT LOWER LEVEL SATURATION AHEAD OF
THIS SYSTEM. SOUNDINGS ALSO SHOW WARM AIR ADVECTION IN THE LOWEST
LEVELS THAT WILL ALLOW ANY PRECIP ON THURSDAY MORNING TO FALL AS
RAIN. 300K GFS ISENTROPIC SURFACE SHOWS GOOD UPGLIDE ALONG WITH A
SURGE OF SPECIFIC HUMIDITIES OF 2 G/KG. THUS ROUND OF LIGHT PRECIP
IS EXPECTED. BY THURSDAY AFTERNOON THE UPPER SHORT WAVE LOOKS TO
BE WELL EAST OF INDIANA AND COLD AIR ADVECTION WILL ONCE AGAIN BE
IN PLAY. FORECAST SOUNDINGS SHOW THE SATURATED LOWER PARTS OF THE
COLUMN FALLING BELOW FREEZING...THUS A CHANGE OVER TO SNOW DURING
THE AFTERNOON FOR ANY LINGERING PRECIP LOOKS REASONABLE. HOWEVER
WITH A LACK OF DEEP MOISTURE AND THE BEST FORCING OFF TO THE
EAST...ANY SNOW AMOUNTS WILL BE QUITE LIGHT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
ISSUED AT 300 AM EST TUE JAN 27 2015
NORTHWEST FLOW ALOFT AND STRONG CANADIAN HIGH PRESSURE WILL ENSURE
A COLD START TO THE EXTENDED PERIOD ON FRIDAY IN THE WAKE OF THE
COLD FRONTAL PASSAGE ON THURSDAY. THE HIGH WILL DRIFT EAST THROUGH
SATURDAY MAINTAINING DRY CHILLY CONDITIONS ACROSS CENTRAL INDIANA.
HIGHS WILL GENERALLY RANGE FROM THE UPPER 20S TO MID 30S BOTH DAYS.
THE MAIN FOCUS FOR THE EXTENDED PERIOD COMES DURING THE SECOND
HALF OF THE WEEKEND AS A STRENGTHENING SURFACE WAVE TRACKS FROM
THE WESTERN GULF SUNDAY MORNING INTO NEW ENGLAND BY MONDAY. MODEL
GUIDANCE HAS WAVERED WITH THE HANDLING OF THIS SYSTEM OVER THE
LAST FEW DAYS RANGING FROM A SUPPRESSED SYSTEM TRACKING THROUGH
THE SOUTHERN STATES TO A MORE PHASED SOLUTION BRINGING A GREATER
IMPACT NORTH INTO THE OHIO VALLEY. 00Z GUIDANCE IN GENERAL HAS
TRENDED BACK TOWARDS THE MORE PHASED UPPER WAVE WITH A SURFACE
WAVE TRACKING THROUGH THE TENNESSEE VALLEY SUNDAY INTO SUNDAY
NIGHT AND A BROAD AREA OF OVERRUNNING PRECIPITATION SPREADING
ACROSS THE ENTIRE REGION.
WITH COLD AIR LINGERING ACROSS CENTRAL INDIANA AND THE TRACK TO
THE SOUTH OF THE FORECAST AREA...PRECIP WOULD LIKELY FALL AS SNOW
AS IT STANDS NOW WITH POSSIBLY A BRIEF PERIOD OF MIXED PRECIP ON
SUNDAY DEPENDING ON THE AMOUNT OF WARMTH IN THE BOUNDARY LAYER
THAT CAN TAKE PLACE. STILL SEVERAL DAYS OUT AND LIKELY TO SEE
ADDITIONAL CHANGES AS WE NEAR THE WEEKEND. ONE CAVEAT TO KEEP IN
MIND...MODEL GUIDANCE IN GENERAL HAS UNDERDONE LOW LEVEL WARM
INTRUSIONS AND CAUSED PRECIP TYPE CHALLENGES ACROSS THE FORECAST
AREA WITH SURFACE WAVES ALL WINTER LONG. NOT SAYING THIS HAPPENS
HERE IF THE FORECAST TRACK THROUGH THE TENNESSEE AND LOWER OHIO
VALLEYS HOLDS. IT IS JUST SOMETHING TO KEEP IN MIND AS MODELS HONE
IN ON A CONSENSUS SOLUTION IN THE COMING DAYS. SHOULD THINGS COME
TOGETHER FOR A PREDOMINANT SNOW EVENT...POTENTIAL IS THERE FOR A
FEW INCHES OF ACCUMULATION LATE SATURDAY NIGHT THROUGH SUNDAY
NIGHT.
ONCE THE SURFACE WAVE PASSES AND DEEPENS OFF THE NEW ENGLAND COAST
MONDAY...A FRESH BATCH OF ARCTIC AIR WILL SPILL INTO THE REGION
FOR EARLY NEXT WEEK. HIGHS MAY STRUGGLE TO GET OUT OF THE TEENS
BOTH MONDAY/TUESDAY ACROSS NORTHERN COUNTIES.
&&
.AVIATION /DISCUSSION FOR THE 270600Z TAF ISSUANCE/...
ISSUED AT 1140 PM EST MON JAN 26 2015
IFR OR WORSE CONDITIONS IN LIGHT SNOW EXPECTED MUCH OF THE NIGHT AT
BMG AND HUF. MVFR OR WORSE POSSIBLE AT LAF THROUGH 07Z OR 08Z IN
LIGHT SNOW OR LIGHT DRIZZLE. BUFKIT DOES NOT FAVOR FREEZING DRIZZLE
AT THE OTHER SITES...HOWEVER RECENT REPORTS OF LIGHT FREEZING
DRIZZLE AT LAF AND NORTH AND WEST DEMAND AT LEAST A MENTION.
PRECIPITATION SHOULD BE ENDING FROM NORTHWEST TO SOUTHEAST...AFTER
09Z AT IND AND HUF AND 10Z AT BMG. FLYING CONDITIONS SHOULD IMPROVE
TO MVFR OR VFR AFTER 15Z WITH ONLY CIRRUS AFTER 00Z WEDNESDAY.
WINDS WILL BE LIGHT AND VARIABLE TO CALM OVERNIGHT AND BECOME
NORTHEAST AND NORTH 8 KNOTS OR LESS AFTER 15Z BEFORE BECOMING LIGHT
AND VARIABLE ONCE AGAIN AFTER 00Z WEDNESDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...PUMA
NEAR TERM...TDUD
SHORT TERM...PUMA
LONG TERM....RYAN
AVIATION...KOCH
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1141 PM EST MON JAN 26 2015
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 152 PM EST MON JAN 26 2015
A QUICK MOVING WEATHER DISTURBANCE WILL PUSH ACROSS ILLINOIS AND
INDIANA THIS EVENING...BRINGING CHANCES FOR SOME LIGHT SNOW THIS
EVENING TO WESTERN PARTS OF CENTRAL INDIANA.
COLD HIGH PRESSURE IS EXPECTED TO ARRIVE ON TUESDAY AND CONTINUE
TO REMAIN IN THE AREA THROUGH WEDNESDAY NIGHT. THIS WILL RESULT IN
DRY WEATHER WITH BELOW NORMAL TEMPERATURES. ANOTHER QUICK MOVING
AREA OF LOW PRESSURE IS EXPECTED TO ARRIVE AND PASS ACROSS CENTRAL
INDIANA ON EARLY THURSDAY MORNING...ONCE AGAIN RESULTING IN CHANCES
FOR PRECIPITATION.
ANOTHER WEAK LOW PRESSURE SYSTEM IS EXPECTED TO PUSH ACROSS THE
REGION THIS WEEKEND...ONCE AGAIN RESULTING IN CHANCES FOR
PRECIPITATION.
&&
.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 1039 PM EST MON JAN 26 2015
UPDATE...
INSERTED MENTION OF PATCHY FREEZING DRIZZLE ACROSS THE WESTERN
PORTIONS OF CENTRAL INDIANA. FREEZING DRIZZLE HAS BEEN REPORTED
UPSTREAM. CONTINUED TO LEAVE FAR NORTHEAST COUNTIES DRY EXCEPT FOR
A FEW FLURRIES. UPDATED GRIDS HAVE BEEN SENT.
PREVIOUS DISCUSSION...
MAIN FORECAST CHALLENGE WILL BE PRECIP THIS EVENING. GFS SUGGESTS
THE UPPER WAVE RESPONSIBLE FOR THE ONGOING SNOW OVER ILLINOIS WILL
CONTINUE TO DIVE SSE AMID THE QUICK FLOW ALOFT. HRRR SHOW PRECIP
MAINLY CONTAINED TO THE WESTERN PARTS OF THE FORECAST AREA. TIME
HEIGHTS THIS EVENING SHOW BEST SATURATION IN THE WESTERN AND
SOUTHERN PARTS OF THE FORECAST AREA...WITH LESS MOISTURE AVAILABLE
ACROSS THE NORTHEAST. ISENTROPIC SURFACE SHOWS LITTLE TO NO HELP
AS THIS SYSTEM PASSES. FORECAST SOUNDINGS ACROSS WESTERN INDIANA
CONTINUE TO SHOW GOOD LOW AND MID LEVEL SATURATION THROUGH THE
NIGHT.
THUS WILL RAISE POPS...PARTICULARLY ACROSS THE WESTERN PARTS OF
THE FORECAST AREA...TRENDING TOWARD A FLURRY OR DRY FORECAST ACROSS
THE FAR NORTHEAST. AS FOR TEMPS...CLOUDS ARE EXPECTED THROUGH MUCH
OF THE NIGHT AS THE UPPER WAVE PASSES AND TEMPERATURE ADVECTION IS
NEUTRAL. THUS WILL STICK CLOSE TO A BLEND ON TEMPS.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
ISSUED AT 152 PM EST MON JAN 26 2015
MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE TEMPS INITIALLY
FOLLOWED BY PRECIPITATION CHANCES ON THURSDAY.
DRY AND COLD WEATHER IS EXPECTED THROUGH WEDNESDAY DUE TO THE
FOLLOWING REASONS:
SURFACE HIGH PRESSURE BUILDING OUT OF CANADA WILL BUILD ACROSS AND
PASS OVER CENTRAL INDIANA THROUGH WEDNESDAY NIGHT. TIME HEIGHT
SECTIONS THROUGH WEDNESDAY NIGHT CONTINUE TO SHOW A DRY COLUMN
AMID SUBSIDENCE. FORECAST SOUNDINGS AGREE...ONLY SHOWING SOME
SATURATION NEAR 12Z THURSDAY. MEANWHILE ALOFT...A DEEP TROUGH OVER
EASTERN 1/2 OF THE UNITED STATES WILL CONTINUE TO PROVIDE A VERY
COLD AND NW FLOW TO CENTRAL INDIANA. THIS WILL HELP IN RESULTING
IN BELOW NORMAL TEMPERATURES. THUS WITH ONLY A FEW QUICK PASSING
HIGH CLOUDS EXPECTED...WILL TREND TOWARD PARTLY CLOUDY ON TUESDAY
THROUGH WEDNESDAY EVENING...ALONG WITH A BLEND ON TEMPS.
ON LATE WEDNESDAY NIGHT THE GFS INDICATES A WELL ORGANIZED SHORT
WAVE ALOFT PUSHING INTO INDIANA FROM THE WEST. ONCE
AGAIN...FORECAST SOUNDINGS HINT AT LOWER LEVEL SATURATION AHEAD OF
THIS SYSTEM. SOUNDINGS ALSO SHOW WARM AIR ADVECTION IN THE LOWEST
LEVELS THAT WILL ALLOW ANY PRECIP ON THURSDAY MORNING TO FALL AS
RAIN. 300K GFS ISENTROPIC SURFACE SHOWS GOOD UPGLIDE ALONG WITH A
SURGE OF SPECIFIC HUMIDITIES OF 2 G/KG. THUS ROUND OF LIGHT PRECIP
IS EXPECTED. BY THURSDAY AFTERNOON THE UPPER SHORT WAVE LOOKS TO
BE WELL EAST OF INDIANA AND COLD AIR ADVECTION WILL ONCE AGAIN BE
IN PLAY. FORECAST SOUNDINGS SHOW THE SATURATED LOWER PARTS OF THE
COLUMN FALLING BELOW FREEZING...THUS A CHANGE OVER TO SNOW DURING
THE AFTERNOON FOR ANY LINGERING PRECIP LOOKS REASONABLE. HOWEVER
WITH A LACK OF DEEP MOISTURE AND THE BEST FORCING OFF TO THE
EAST...ANY SNOW AMOUNTS WILL BE QUITE LIGHT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 250 PM EST MON JAN 26 2015
ONE SYSTEM WILL BE EXITING OUR REGION THURSDAY EVENING...THUS WILL
CONTINUE A SLIGHT CHANCE OF SNOW EAST AND CENTRAL THURSDAY EVENING.
HIGH PRESSURE BEHIND THIS SYSTEM WILL MOVE ACROSS OUR REGION FRIDAY
NIGHT AND IT NOW LOOKS LIKE DRY WEATHER WILL BE THE RULE THROUGH
SATURDAY.
ANOTHER SYSTEM WILL BRING US A CHANCE OF SNOW SATURDAY NIGHT INTO
SUNDAY AS THE MODELS HAVE TRENDED SLOWER WITH THIS SYSTEM.
FINALLY COLDER AND DRY WEATHER WILL BE THE RULE REST OF THE LONG
TERM AS A LONG WAVE TROUGH AMPLIFIES OVER THE EASTERN U.S. THE
MODELS HAVE TRENDED A LITTLE COLDER DURING THIS PERIOD. BUT ALL AND
ALL WENT CLOSE TO A MOS BLEND ON TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR THE 270600Z TAF ISSUANCE/...
ISSUED AT 1140 PM EST MON JAN 26 2015
IFR OR WORSE CONDITIONS IN LIGHT SNOW EXPECTED MUCH OF THE NIGHT AT
BMG AND HUF. MVFR OR WORSE POSSIBLE AT LAF THROUGH 07Z OR 08Z IN
LIGHT SNOW OR LIGHT DRIZZLE. BUFKIT DOES NOT FAVOR FREEZING DRIZZLE
AT THE OTHER SITES...HOWEVER RECENT REPORTS OF LIGHT FREEZING
DRIZZLE AT LAF AND NORTH AND WEST DEMAND AT LEAST A MENTION.
PRECIPITATION SHOULD BE ENDING FROM NORTHWEST TO SOUTHEAST...AFTER
09Z AT IND AND HUF AND 10Z AT BMG. FLYING CONDITIONS SHOULD IMPROVE
TO MVFR OR VFR AFTER 15Z WITH ONLY CIRRUS AFTER 00Z WEDNESDAY.
WINDS WILL BE LIGHT AND VARIABLE TO CALM OVERNIGHT AND BECOME
NORTHEAST AND NORTH 8 KNOTS OR LESS AFTER 15Z BEFORE BECOMING LIGHT
AND VARIABLE ONCE AGAIN AFTER 00Z WEDNESDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...PUMA
NEAR TERM...TDUD
SHORT TERM...PUMA
LONG TERM....JH
AVIATION...KOCH
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
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AREA FORECAST DISCUSSION
NWS DES MOINES IA
1145 AM CST TUE JAN 27 2015
.SHORT TERM /TODAY/...
ISSUED AT 355 AM CST TUE JAN 27 2015
MAIN CONCERNS TODAY WILL BE TEMPS AND CLOUD COVER THROUGH THE
MORNING HOURS...AND PERHAPS A PORTION OF THE AFTERNOON EAST. TO
VARYING DEGREES...MODELS ALL HINT AT SOME CLOUDS MOVING SOUTHEAST
ALONG THE EASTERN EDGE OF THE H700 RIDGE CAUGHT IN THE NORTHWEST
FLOW EARLY TODAY. HOWEVER...NONE OF THE MODELS IS DOING VERY WELL.
THE HRRR AND NMM WRF MAY HAVE A SLIGHTLY BETTER HANDLE ON THE
SITUATION. EXAMINING THE UPPER LEVEL H700 RIDGE THROUGH THE DAY
TODAY SHOWS THAT IT IS LIKELY TO CONTINUE BUILDING EAST THROUGH THE
AFTERNOON HOURS...ENDING ANY CYCLONIC PORTION OF CIRCULATION WHICH
IS ASSOCIATED WITH THE LEFTOVER SYSTEM FROM YESTERDAY. AT 00Z TUE
THE H850 ANALYSIS SHOWED A PRONOUNCED WAVE TRACKING THROUGH EASTERN
IOWA BACK NORTH TOWARD MINNEAPOLIS...BUT NORTHWEST OF THERE THE FLOW
BECOMES MORE ANTICYCLONIC OVER THE EASTERN DAKOTAS. ANOTHER UPSTREAM
TROUGH IS ALREADY DEVELOPING WITH AN ATTENDANT WARM FRONT OVER THE
WESTERN DAKOTAS. SOME CLOUDS OVER SASKATCHEWAN AND MANITOBA MAY
TRACK SOUTHEAST TOWARD THE REGION THIS AFTERNOON BUT LIKELY ONLY
AFFECT THE FAR EASTERN COUNTIES WITH MID TO HIGH LEVEL CLOUDS. BASED
ON CLOUDS AND LATER TRAJECTORIES...COOLER HIGHS WILL BE HAD OVER THE
NORTHEAST HALF OF THE FORECAST AREA WHILE THE SOUTHWEST HALF WILL
REMAIN MILD FOR JANUARY...BUT NOT AS WARM AS YESTERDAY. WITH A
RATHER WEAK RIDGE AXIS PASSING OVER THE AREA TODAY WINDS WILL REMAIN
LIGHT. HIGHS WILL RANGE FROM THE UPPER 30S NORTHEAST TO THE UPPER
40S SOUTHWEST.
.LONG TERM /TONIGHT THROUGH MONDAY/...
ISSUED AT 355 AM CST TUE JAN 27 2015
AM EXPECTING MAX TEMPS FOR WED TO BE VERY SIMILAR TO MONDAY`S HIGHS.
A WARM FRONT WILL CUT ACROSS THE MIDDLE OF THE CWA...LEADING TO A
NOTABLE TEMP GRADIENT...FROM NW TO SE. LOW 40S EXPECTED IN NE CWA
AND UPPER 50S IN SW CWA. NAM MORE AGGRESSIVE WITH LOW LEVEL CLOUD
COVER AND THUS IS A COOL OUTLIER. NAM ALSO STILL THINKS THERE IS
SNOW ACROSS THE CWA SO AM DISCARDING NAM SOLUTION.
A VERY FAST MOVING SHORTWAVE TO IMPACT CWA THURSDAY MORNING. THROUGH
WATER VAPOR IMAGERY...THIS SHORTWAVE CAN BE EASILY PICKED UP COMING
ONTO THE CALIFORNIA COAST AT 06Z TUE. MODELS INITIALIZING WELL WITH
PLACEMENT OF THIS LOW AS IT COMES ONSHORE.
ADDITIONALLY...MODELS CONVERGING ON SOLUTION OF PUTTING THE WAVE
DIRECTLY OVER CENTRAL IOWA AT 06Z THU. THERE IS A SIZABLE DRY AIR
POCKET FROM AROUND 850MB TO 500MB WHICH WILL PREVENT CLOUD
THICKNESS FROM EXCEEDING 5 KFT AND...SUBSEQUENTLY...KEEP THIS
SYSTEM FROM PRODUCING ANYTHING BEYOND LIGHT PRECIP. HAVE BUMPED
UP TEMPS FROM PVS SHIFT. KMCW TO KEST GFS SOUNDINGS SUPPORT MAINLY
DZ/-RA...WITH A VERY NARROW WINDOW OF -IP TO -SN POSSIBLE FROM
AROUND 09Z TO 12Z. PROFILE DURING THIS TIME IS BELOW ZERO UNTIL
NEAR SFC...WHICH IS NOT ENOUGH WARM LAYER DEPTH TO FULLY MELT ALL
SNOW FLAKES. BY 12Z THU...THIS LOW WILL BE OVER NORTHERN ILLINOIS
AND STRONG CAA PLUS SUBSIDENCE WILL BE ADVECTED INTO OUR CWA.
THOUGH SUNSHINE EXPECTED...DAYTIME TEMPS TO ONLY WARM AROUND 3 TO
5 DEGREES FROM OVERNIGHT MINS DUE TO CAA.
THURSDAY`S WINDS ALSO WORTH MENTIONING. MODELS SHOWING 25 KT TO 30
KT WINDS RIGHT OFF THE DECK...APPROACHING 35 KT TO 40 KT TO THE TOP
OF THE MIXED LAYER. SFC PRESSURE GRADIENT OF 3MB/100KM TO SUPPORT
STRONG WINDS AT THE SFC. IN ALL...MAY APPROACH WIND ADVISORY
CRITERIA STARTING EARLY THU AM AND HEADLINE MAY BE WARRANTED IF THIS
SOLUTION HOLDS. A STRONG SFC HIGH WILL MOVE THROUGH THE MIDWEST
FRIDAY...KEEPING FRIDAY QUIET AND HELPING TO DECOUPLE WINDS HEADING
INTO SATURDAY.
FOR THIS WEEKEND...THE 00Z RUNS ARE HOLDING AS THEY ARE SHOWING AN
ALBERTA CLIPPER TYPE SYSTEM LOOKS TO PASS THROUGH THE GREAT LAKES
REGION. THERE WILL BE AN ATTENDANT COLD FRONT TO THIS LOW WHICH IS
BEING PROGGED TO PROPAGATE THROUGH THE CWA SUNDAY MORNING. THE
TIMING HAS CHANGED SOME FROM THE 12Z MON MODEL RUNS TO THE 00Z TUE
RUNS...WITH THE EURO AND GFS DROPPING BACK FROPA UNTIL AROUND 06Z
TO 12Z SUN. MODELS SATURATE THE SKIES FROM TOP DOWN IN ADVANCE OF
THIS SYSTEM...STARTING SATURDAY MORNING. PUSHING TIMING BACK SEEMS
REASONABLE...AS LOW LEVELS NOT SATURATED UNTIL AFTER 00Z SUN. THUS
HAVE PUSHED BACK POPS SLIGHTLY. SOUNDING PROFILE COMPLETELY
SATURATED AND WELL BELOW FREEZING SUNDAY MORNING. HAVE BEGUN TO
NUDGE SUNDAY MORNING POPS UPWARD...WITH FURTHER INCREASES
CERTAINLY POSSIBLE IF THE MODEL SOLNS CONTINUE TO HOLD.
THE PAST FEW MODEL RUNS HAVE CERTAINLY BEEN TRENDING DOWNWARD WITH
TEMPERATURES BEHIND THIS FRONT. ENSEMBLES HAVE 850 MB TEMPS DOWN TO
THE -12C TO -15C RANGE ACROSS THE CWA. SINGLE DIGIT TEMPERATURES
APPEAR VERY POSSIBLE MONDAY AND TUESDAY MORNING.
&&
.AVIATION...27/18Z
ISSUED AT 1145 AM CST TUE JAN 27 2015
LOW LEVEL MOISTURE WILL LIKELY KEEP CLOUDS ACROSS THE FAR EAST AND
NORTH AFFECTING KMCW...KALO AND KOTM THROUGH AT LEAST 21Z. THE
FORECAST BECOMES PROBLEMATIC AFTER 06Z. WINDS SWITCH AROUND TO THE
SE BUT REMAIN LIGHT AND MODELS ARE NOT HANDLING THE LOW LEVEL
MOISTURE VERY WELL. WITH LIGHTER FLOW IT DOES NOT APPEAR THIS
MOISTURE WILL GET MOVED OUT SO I WENT MORE PESSIMISTIC ON THE CLOUD
COVER THROUGH THE PERIOD SINCE ALL MODELS SUGGEST AT LEAST SOME LOW
LEVEL MOISTURE REMAINING THROUGH 28/18Z.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...REV
LONG TERM...KOTENBERG
AVIATION...FAB
AREA FORECAST DISCUSSION
NWS DES MOINES IA
537 AM CST TUE JAN 27 2015
.SHORT TERM /TODAY/...
ISSUED AT 355 AM CST TUE JAN 27 2015
MAIN CONCERNS TODAY WILL BE TEMPS AND CLOUD COVER THROUGH THE
MORNING HOURS...AND PERHAPS A PORTION OF THE AFTERNOON EAST. TO
VARYING DEGREES...MODELS ALL HINT AT SOME CLOUDS MOVING SOUTHEAST
ALONG THE EASTERN EDGE OF THE H700 RIDGE CAUGHT IN THE NORTHWEST
FLOW EARLY TODAY. HOWEVER...NONE OF THE MODELS IS DOING VERY WELL.
THE HRRR AND NMM WRF MAY HAVE A SLIGHTLY BETTER HANDLE ON THE
SITUATION. EXAMINING THE UPPER LEVEL H700 RIDGE THROUGH THE DAY
TODAY SHOWS THAT IT IS LIKELY TO CONTINUE BUILDING EAST THROUGH THE
AFTERNOON HOURS...ENDING ANY CYCLONIC PORTION OF CIRCULATION WHICH
IS ASSOCIATED WITH THE LEFTOVER SYSTEM FROM YESTERDAY. AT 00Z TUE
THE H850 ANALYSIS SHOWED A PRONOUNCED WAVE TRACKING THROUGH EASTERN
IOWA BACK NORTH TOWARD MINNEAPOLIS...BUT NORTHWEST OF THERE THE FLOW
BECOMES MORE ANTICYCLONIC OVER THE EASTERN DAKOTAS. ANOTHER UPSTREAM
TROUGH IS ALREADY DEVELOPING WITH AN ATTENDANT WARM FRONT OVER THE
WESTERN DAKOTAS. SOME CLOUDS OVER SASKATCHEWAN AND MANITOBA MAY
TRACK SOUTHEAST TOWARD THE REGION THIS AFTERNOON BUT LIKELY ONLY
AFFECT THE FAR EASTERN COUNTIES WITH MID TO HIGH LEVEL CLOUDS. BASED
ON CLOUDS AND LATER TRAJECTORIES...COOLER HIGHS WILL BE HAD OVER THE
NORTHEAST HALF OF THE FORECAST AREA WHILE THE SOUTHWEST HALF WILL
REMAIN MILD FOR JANUARY...BUT NOT AS WARM AS YESTERDAY. WITH A
RATHER WEAK RIDGE AXIS PASSING OVER THE AREA TODAY WINDS WILL REMAIN
LIGHT. HIGHS WILL RANGE FROM THE UPPER 30S NORTHEAST TO THE UPPER
40S SOUTHWEST.
.LONG TERM /TONIGHT THROUGH MONDAY/...
ISSUED AT 355 AM CST TUE JAN 27 2015
AM EXPECTING MAX TEMPS FOR WED TO BE VERY SIMILAR TO MONDAY`S HIGHS.
A WARM FRONT WILL CUT ACROSS THE MIDDLE OF THE CWA...LEADING TO A
NOTABLE TEMP GRADIENT...FROM NW TO SE. LOW 40S EXPECTED IN NE CWA
AND UPPER 50S IN SW CWA. NAM MORE AGGRESSIVE WITH LOW LEVEL CLOUD
COVER AND THUS IS A COOL OUTLIER. NAM ALSO STILL THINKS THERE IS
SNOW ACROSS THE CWA SO AM DISCARDING NAM SOLUTION.
A VERY FAST MOVING SHORTWAVE TO IMPACT CWA THURSDAY MORNING. THROUGH
WATER VAPOR IMAGERY...THIS SHORTWAVE CAN BE EASILY PICKED UP COMING
ONTO THE CALIFORNIA COAST AT 06Z TUE. MODELS INITIALIZING WELL WITH
PLACEMENT OF THIS LOW AS IT COMES ONSHORE.
ADDITIONALLY...MODELS CONVERGING ON SOLUTION OF PUTTING THE WAVE
DIRECTLY OVER CENTRAL IOWA AT 06Z THU. THERE IS A SIZABLE DRY AIR
POCKET FROM AROUND 850MB TO 500MB WHICH WILL PREVENT CLOUD
THICKNESS FROM EXCEEDING 5 KFT AND...SUBSEQUENTLY...KEEP THIS
SYSTEM FROM PRODUCING ANYTHING BEYOND LIGHT PRECIP. HAVE BUMPED
UP TEMPS FROM PVS SHIFT. KMCW TO KEST GFS SOUNDINGS SUPPORT MAINLY
DZ/-RA...WITH A VERY NARROW WINDOW OF -IP TO -SN POSSIBLE FROM
AROUND 09Z TO 12Z. PROFILE DURING THIS TIME IS BELOW ZERO UNTIL
NEAR SFC...WHICH IS NOT ENOUGH WARM LAYER DEPTH TO FULLY MELT ALL
SNOW FLAKES. BY 12Z THU...THIS LOW WILL BE OVER NORTHERN ILLINOIS
AND STRONG CAA PLUS SUBSIDENCE WILL BE ADVECTED INTO OUR CWA.
THOUGH SUNSHINE EXPECTED...DAYTIME TEMPS TO ONLY WARM AROUND 3 TO
5 DEGREES FROM OVERNIGHT MINS DUE TO CAA.
THURSDAY`S WINDS ALSO WORTH MENTIONING. MODELS SHOWING 25 KT TO 30
KT WINDS RIGHT OFF THE DECK...APPROACHING 35 KT TO 40 KT TO THE TOP
OF THE MIXED LAYER. SFC PRESSURE GRADIENT OF 3MB/100KM TO SUPPORT
STRONG WINDS AT THE SFC. IN ALL...MAY APPROACH WIND ADVISORY
CRITERIA STARTING EARLY THU AM AND HEADLINE MAY BE WARRANTED IF THIS
SOLUTION HOLDS. A STRONG SFC HIGH WILL MOVE THROUGH THE MIDWEST
FRIDAY...KEEPING FRIDAY QUIET AND HELPING TO DECOUPLE WINDS HEADING
INTO SATURDAY.
FOR THIS WEEKEND...THE 00Z RUNS ARE HOLDING AS THEY ARE SHOWING AN
ALBERTA CLIPPER TYPE SYSTEM LOOKS TO PASS THROUGH THE GREAT LAKES
REGION. THERE WILL BE AN ATTENDANT COLD FRONT TO THIS LOW WHICH IS
BEING PROGGED TO PROPAGATE THROUGH THE CWA SUNDAY MORNING. THE
TIMING HAS CHANGED SOME FROM THE 12Z MON MODEL RUNS TO THE 00Z TUE
RUNS...WITH THE EURO AND GFS DROPPING BACK FROPA UNTIL AROUND 06Z
TO 12Z SUN. MODELS SATURATE THE SKIES FROM TOP DOWN IN ADVANCE OF
THIS SYSTEM...STARTING SATURDAY MORNING. PUSHING TIMING BACK SEEMS
REASONABLE...AS LOW LEVELS NOT SATURATED UNTIL AFTER 00Z SUN. THUS
HAVE PUSHED BACK POPS SLIGHTLY. SOUNDING PROFILE COMPLETELY
SATURATED AND WELL BELOW FREEZING SUNDAY MORNING. HAVE BEGUN TO
NUDGE SUNDAY MORNING POPS UPWARD...WITH FURTHER INCREASES
CERTAINLY POSSIBLE IF THE MODEL SOLNS CONTINUE TO HOLD.
THE PAST FEW MODEL RUNS HAVE CERTAINLY BEEN TRENDING DOWNWARD WITH
TEMPERATURES BEHIND THIS FRONT. ENSEMBLES HAVE 850 MB TEMPS DOWN TO
THE -12C TO -15C RANGE ACROSS THE CWA. SINGLE DIGIT TEMPERATURES
APPEAR VERY POSSIBLE MONDAY AND TUESDAY MORNING.
&&
.AVIATION...27/12Z
ISSUED AT 537 AM CST TUE JAN 27 2015
MAIN CONCERNS THROUGH THE PERIOD ARE LOW CLOUDS. CLOUDS TRAPPED
WITHIN A WEAK UPPER LEVEL RIDGE CONTINUE TO DRIFT SLOWLY SOUTHWEST
INTO THE NORTHEAST AND NORTHERN PORTIONS OF THE FORECAST AREA AT
1130Z. MEANWHILE THE UPPER LEVEL H700 RIDGE IS EXPECTED TO SLOWLY
DRIFT EAST...FORCING THE DECK OF IFR/MVFR CONDITIONS TO SLIDE EAST
AS WELL. THE RAP AND 06Z GFS SUGGEST THE DECK WILL HOLD ON LONGER
...ESPECIALLY NORTHEAST AT KMCW AND KALO. HAVE LENGTHENED CLOUD
RESIDENCE TIME THROUGH 18Z WITH GRADUAL SCT CONDITIONS RETURNING
AFT 18Z THERE. AT THIS TIME...WILL CONTINUE VFR CONDITIONS AT KDSM
AND KOTM WITH BRIEF PERIOD OF MVFR CIGS AT KFOD BETWEEN 15 AND
17Z. REMAINDER OF PERIOD STRONGER SOUTHEAST FLOW RETURNS WITH 12KT
SUSTAINED AND GUSTS AFT 07Z WEST AND NORTH SITES. /REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...REV
LONG TERM...KOTENBERG
AVIATION...REV
AREA FORECAST DISCUSSION
NWS DES MOINES IA
358 AM CST TUE JAN 27 2015
.SHORT TERM /TODAY/...
ISSUED AT 355 AM CST TUE JAN 27 2015
MAIN CONCERNS TODAY WILL BE TEMPS AND CLOUD COVER THROUGH THE
MORNING HOURS...AND PERHAPS A PORTION OF THE AFTERNOON EAST. TO
VARYING DEGREES...MODELS ALL HINT AT SOME CLOUDS MOVING SOUTHEAST
ALONG THE EASTERN EDGE OF THE H700 RIDGE CAUGHT IN THE NORTHWEST
FLOW EARLY TODAY. HOWEVER...NONE OF THE MODELS IS DOING VERY WELL.
THE HRRR AND NMM WRF MAY HAVE A SLIGHTLY BETTER HANDLE ON THE
SITUATION. EXAMINING THE UPPER LEVEL H700 RIDGE THROUGH THE DAY
TODAY SHOWS THAT IT IS LIKELY TO CONTINUE BUILDING EAST THROUGH THE
AFTERNOON HOURS...ENDING ANY CYCLONIC PORTION OF CIRCULATION WHICH
IS ASSOCIATED WITH THE LEFTOVER SYSTEM FROM YESTERDAY. AT 00Z TUE
THE H850 ANALYSIS SHOWED A PRONOUNCED WAVE TRACKING THROUGH EASTERN
IOWA BACK NORTH TOWARD MINNEAPOLIS...BUT NORTHWEST OF THERE THE FLOW
BECOMES MORE ANTICYCLONIC OVER THE EASTERN DAKOTAS. ANOTHER UPSTREAM
TROUGH IS ALREADY DEVELOPING WITH AN ATTENDANT WARM FRONT OVER THE
WESTERN DAKOTAS. SOME CLOUDS OVER SASKATCHEWAN AND MANITOBA MAY
TRACK SOUTHEAST TOWARD THE REGION THIS AFTERNOON BUT LIKELY ONLY
AFFECT THE FAR EASTERN COUNTIES WITH MID TO HIGH LEVEL CLOUDS. BASED
ON CLOUDS AND LATER TRAJECTORIES...COOLER HIGHS WILL BE HAD OVER THE
NORTHEAST HALF OF THE FORECAST AREA WHILE THE SOUTHWEST HALF WILL
REMAIN MILD FOR JANUARY...BUT NOT AS WARM AS YESTERDAY. WITH A
RATHER WEAK RIDGE AXIS PASSING OVER THE AREA TODAY WINDS WILL REMAIN
LIGHT. HIGHS WILL RANGE FROM THE UPPER 30S NORTHEAST TO THE UPPER
40S SOUTHWEST.
.LONG TERM /TONIGHT THROUGH MONDAY/...
ISSUED AT 355 AM CST TUE JAN 27 2015
AM EXPECTING MAX TEMPS FOR WED TO BE VERY SIMILAR TO MONDAY`S HIGHS.
A WARM FRONT WILL CUT ACROSS THE MIDDLE OF THE CWA...LEADING TO A
NOTABLE TEMP GRADIENT...FROM NW TO SE. LOW 40S EXPECTED IN NE CWA
AND UPPER 50S IN SW CWA. NAM MORE AGGRESSIVE WITH LOW LEVEL CLOUD
COVER AND THUS IS A COOL OUTLIER. NAM ALSO STILL THINKS THERE IS
SNOW ACROSS THE CWA SO AM DISCARDING NAM SOLUTION.
A VERY FAST MOVING SHORTWAVE TO IMPACT CWA THURSDAY MORNING. THROUGH
WATER VAPOR IMAGERY...THIS SHORTWAVE CAN BE EASILY PICKED UP COMING
ONTO THE CALIFORNIA COAST AT 06Z TUE. MODELS INITIALIZING WELL WITH
PLACEMENT OF THIS LOW AS IT COMES ONSHORE.
ADDITIONALLY...MODELS CONVERGING ON SOLUTION OF PUTTING THE WAVE
DIRECTLY OVER CENTRAL IOWA AT 06Z THU. THERE IS A SIZABLE DRY AIR
POCKET FROM AROUND 850MB TO 500MB WHICH WILL PREVENT CLOUD
THICKNESS FROM EXCEEDING 5 KFT AND...SUBSEQUENTLY...KEEP THIS
SYSTEM FROM PRODUCING ANYTHING BEYOND LIGHT PRECIP. HAVE BUMPED
UP TEMPS FROM PVS SHIFT. KMCW TO KEST GFS SOUNDINGS SUPPORT MAINLY
DZ/-RA...WITH A VERY NARROW WINDOW OF -IP TO -SN POSSIBLE FROM
AROUND 09Z TO 12Z. PROFILE DURING THIS TIME IS BELOW ZERO UNTIL
NEAR SFC...WHICH IS NOT ENOUGH WARM LAYER DEPTH TO FULLY MELT ALL
SNOW FLAKES. BY 12Z THU...THIS LOW WILL BE OVER NORTHERN ILLINOIS
AND STRONG CAA PLUS SUBSIDENCE WILL BE ADVECTED INTO OUR CWA.
THOUGH SUNSHINE EXPECTED...DAYTIME TEMPS TO ONLY WARM AROUND 3 TO
5 DEGREES FROM OVERNIGHT MINS DUE TO CAA.
THURSDAY`S WINDS ALSO WORTH MENTIONING. MODELS SHOWING 25 KT TO 30
KT WINDS RIGHT OFF THE DECK...APPROACHING 35 KT TO 40 KT TO THE TOP
OF THE MIXED LAYER. SFC PRESSURE GRADIENT OF 3MB/100KM TO SUPPORT
STRONG WINDS AT THE SFC. IN ALL...MAY APPROACH WIND ADVISORY
CRITERIA STARTING EARLY THU AM AND HEADLINE MAY BE WARRANTED IF THIS
SOLUTION HOLDS. A STRONG SFC HIGH WILL MOVE THROUGH THE MIDWEST
FRIDAY...KEEPING FRIDAY QUIET AND HELPING TO DECOUPLE WINDS HEADING
INTO SATURDAY.
FOR THIS WEEKEND...THE 00Z RUNS ARE HOLDING AS THEY ARE SHOWING AN
ALBERTA CLIPPER TYPE SYSTEM LOOKS TO PASS THROUGH THE GREAT LAKES
REGION. THERE WILL BE AN ATTENDANT COLD FRONT TO THIS LOW WHICH IS
BEING PROGGED TO PROPAGATE THROUGH THE CWA SUNDAY MORNING. THE
TIMING HAS CHANGED SOME FROM THE 12Z MON MODEL RUNS TO THE 00Z TUE
RUNS...WITH THE EURO AND GFS DROPPING BACK FROPA UNTIL AROUND 06Z
TO 12Z SUN. MODELS SATURATE THE SKIES FROM TOP DOWN IN ADVANCE OF
THIS SYSTEM...STARTING SATURDAY MORNING. PUSHING TIMING BACK SEEMS
REASONABLE...AS LOW LEVELS NOT SATURATED UNTIL AFTER 00Z SUN. THUS
HAVE PUSHED BACK POPS SLIGHTLY. SOUNDING PROFILE COMPLETELY
SATURATED AND WELL BELOW FREEZING SUNDAY MORNING. HAVE BEGUN TO
NUDGE SUNDAY MORNING POPS UPWARD...WITH FURTHER INCREASES
CERTAINLY POSSIBLE IF THE MODEL SOLNS CONTINUE TO HOLD.
THE PAST FEW MODEL RUNS HAVE CERTAINLY BEEN TRENDING DOWNWARD WITH
TEMPERATURES BEHIND THIS FRONT. ENSEMBLES HAVE 850 MB TEMPS DOWN TO
THE -12C TO -15C RANGE ACROSS THE CWA. SINGLE DIGIT TEMPERATURES
APPEAR VERY POSSIBLE MONDAY AND TUESDAY MORNING.
&&
.AVIATION...27/06Z
ISSUED AT 1131 PM CST MON JAN 26 2015
PRIMARY CONCERN REMAINS PROGRESSION OF MVFR/VFR STRATUS THAT
EXTENDS ALONG AND NE OF KEST-KDSM-KTVK LINE AT 06Z WITH PATCH OF
CLEAR SKIES OVER ERN IA FROM KALO-KOTM. MORE WIDESPREAD LOWER CIGS
THEN EXTEND ALL THE WAY BACK INTO MN...WI AND IL IN BROAD
CYCLONIC FLOW. NONE OF THE MODELS SEEM TO HAVE A GREAT HANDLE
ON CURRENT CONDITIONS ACROSS IA...BUT ALL MODELS SEEM TO SLIDE
THE STRATUS SLOWLY SOUTH AND WEST INTO TUE MORNING. THERE IS HIGH
CONFIDENCE THAT AT LEAST PATCHY MVFR CIGS WILL OOZE SW THROUGH IA...BUT
DURATION CONFIDENCE IS LOW. HAVE LEFT ENDING TIME AT 16Z UNTIL
EXIT TRENDS BECOME MORE CLEAR. RAP AND NAM SUGGEST IN SIMILAR
LOCATIONS WILL INTO TUE...WHILE HIGH RES NMM/ARW MODELS ARE MORE
OPTIMISTIC.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...REV
LONG TERM...KOTENBERG
AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1131 PM CST MON JAN 26 2015
.SHORT TERM /TONIGHT/...
ISSUED AT 341 PM CST MON JAN 26 2015
HIGH PRESSURE RIDGE WILL SHIFT SLOWLY EAST OVERNIGHT AND BE OVER
CENTRAL MINNESOTA AND INTO NW IOWA BY MORNING. OVERNIGHT WINDS WILL
BE OUT OF THE NORTHWEST TO NORTH MUCH OF THE NIGHT. THIS FLOW WILL
EXTEND UP TO NEAR 3-4 KFT AND WILL BE THE STEERING FLOW FOR A BAND
OF STRATUS CLOUDS TO THE NORTH OVER MINNESOTA. THE STRATUS WILL DROP
SOUTH INTO NORTHERN AND CENTRAL IOWA OVERNIGHT AND COMBINED WITH
WINDS 5 TO 8 MPH WILL KEEP TEMPERATURES IN UP OVERNIGHT. CURRENT
DEWPOINTS ARE HIGH AND WELL INTO THE 30S. AS TEMPERATURES
COOL...SOME QUESTION TO THE POTENTIAL FOR FOG FORMATION. STILL WITH
CLOUDS MOVING IN FROM THE NORTH AND PERSISTENT NORTHERLY WINDS...FOG
FORMATION SHOULD BE LIMITED. BEST POTENTIAL WILL BE OVER THE FAR
WEST AS WINDS DIMINISH AS THE RIDGE NEARS FROM THE WEST. DEWPOINTS
ARE EXPECTED TO LOWER OVERNIGHT AS SFC WINDS BECOME MORE NORTHERLY
WITH DEW POINT DEPRESSIONS INCREASING WHICH WILL LIMIT FOG POTENTIAL
AS WELL. LIKELY THE BIGGER HAZARD OVERNIGHT WILL BE FROST FORMATION
ON ROADS WHERE DEWPOINTS REMAIN HIGHER THAN GROUND TEMPERATURES.
.LONG TERM /TUESDAY THROUGH MONDAY/...
ISSUED AT 341 PM CST MON JAN 26 2015
MODEL RESOLUTION IN THE FURTHER OUT PERIODS (SATURDAY THROUGH
MONDAY) OF THE LONG TERM FORECAST ARE COMING INTO A LITTLE BETTER
AGREEMENT TODAY...ALTHOUGH TIMING ISSUES REMAIN. THE GFS IS
STARTING TO LOOK MORE LIKE THE EURO AND CANADIAN MODELS NOW WITH
DEVELOP A TROUGH OVER THE REGION INSTEAD OF A HUGE RIDGE. THAT
MEANS TEMPS WILL BE TRENDING COLDER OVER THE WEEKEND. BY SUNDAY
MODELS ARE SUGGESTING HIGHS ABOUT 8 TO 10 DEGREES BELOW SEASONAL
NORMALS. THERE IS A CHANCE FOR SNOW SATURDAY/SATURDAY NIGHT WITH
THE PASSAGE OF A COLD FRONT BUT AGAIN TIMING ISSUES REMAIN WITH THE
CANADIAN MUCH FASTER AND THE GFS MUCH WETTER. ALONG WITH THE COLD
AND SNOW POTENTIAL...SATURDAY NIGHT AND SUNDAY LOOK BREEZY AS WELL.
WINTER RETURNS NEXT WEEKEND.
GOING BACK TO TOMORROW (TUESDAY) SOUNDINGS SHOW A WARM NOSE OFF THE
SURFACE WHICH IS MORE PRONOUNCED ACROSS THE SOUTH BUT WINDS WILL BE
NORTHERLY AND WIND SPEEDS IN THE LOWEST GATES ARE QUITE LIGHT. AS A
SURFACE LOW MOVES FROM THE PLAINS INTO THE UPPER MIDWEST...SURFACE
WINDS WILL SHIFT AROUND TO THE SOUTHEAST BUT STILL REMAIN LIGHT SO
IT DOES NOT APPEAR THAT THERE WILL BE MUCH MIXING. COUNTERING THAT
WILL BE A LOT OF SUN SO WHILE WE WILL NOT BE AS WARM AS
TODAY...TEMPS SHOULD STILL REACH THE MID 30S NORTHEAST TO LOWER 50S
SOUTHWEST.
DEEPER MIXING AND A LITTLE STRONGER FLOW WILL OCCUR TUESDAY NIGHT
AND WEDNESDAY AND THIS WILL BE OUR WARMEST PERIOD. EXPECTED CLOUD
COVER AHEAD OF AN APPROACHING STILL MAKES ME A LITTLE CAUTIOUS TO
BOOST TEMPS TOO MUCH ON WEDNESDAY...ESPECIALLY SINCE THE SURFACE LOW
SHIFTS INTO THE AREA DURING THE AFTERNOON AND WINDS DIMINISH/SHIFT
BY LATE IN THE DAY BUT I AM COMFORTABLE WITH CURRENT FORECASTS SINCE
THE WARM ADVECTION WILL BE STRONG. EXCEPT FOR THE CANADIAN...ALL
MODELS ARE SIMILAR IN THE TIMING OF THE SHORTWAVE BUT IF THE
SHORTWAVE IS SLOWER OR CLOUD COVER IS NOT EXTENSIVE THEN WE WILL BE
TOO COOL FOR WEDNESDAY. STILL GOING DRY WEDNESDAY WITH JUST SOME
INCREASING CLOUDS THROUGH THE DAY WHICH COULD HAMPER HIGHS.
WHILE MOISTURE WITH THE WEDNESDAY SYSTEM IS WOEFULLY LACKING...IT
SHOULD IMPROVE WEDNESDAY NIGHT...AT LEAST IN THE LOW LEVELS. PRECIP
WILL BE POSSIBLE ALONG AND WITH THE PASSAGE OF A COLD FRONT AND A
SECOND SHORT WAVE WEDNESDAY NIGHT BUT THERE IS NO ICE INTRODUCTION
AND FRANKLY ABOVE 850MB THERE ISN`T MUCH MOISTURE AT ALL AND
NEGLIGIBLE FORCING. ALL THAT I SEE WEDNESDAY NIGHT INTO THURSDAY
MORNING IS A TRANSITION FROM MAY SOME RAIN OR MORE LIKELY DRIZZLE TO
FREEZING DRIZZLE OVERNIGHT INTO EARLY THURSDAY MORNING. THE
REMAINDER OF THURSDAY INTO FRIDAY WILL BE COLD BUT DRY WITH COLD
AIR CONTINUING TO FUNNEL INTO THE REGION THROUGH THE WEEKEND.
&&
.AVIATION...27/06Z
ISSUED AT 1131 PM CST MON JAN 26 2015
PRIMARY CONCERN REMAINS PROGRESSION OF MVFR/VFR STRATUS THAT
EXTENDS ALONG AND NE OF KEST-KDSM-KTVK LINE AT 06Z WITH PATCH OF
CLEAR SKIES OVER ERN IA FROM KALO-KOTM. MORE WIDESPREAD LOWER CIGS
THEN EXTEND ALL THE WAY BACK INTO MN...WI AND IL IN BROAD
CYCLONIC FLOW. NONE OF THE MODELS SEEM TO HAVE A GREAT HANDLE
ON CURRENT CONDITIONS ACROSS IA...BUT ALL MODELS SEEM TO SLIDE
THE STRATUS SLOWLY SOUTH AND WEST INTO TUE MORNING. THERE IS HIGH
CONFIDENCE THAT AT LEAST PATCHY MVFR CIGS WILL OOZE SW THROUGH IA...BUT
DURATION CONFIDENCE IS LOW. HAVE LEFT ENDING TIME AT 16Z UNTIL
EXIT TRENDS BECOME MORE CLEAR. RAP AND NAM SUGGEST IN SIMILAR
LOCATIONS WILL INTO TUE...WHILE HIGH RES NMM/ARW MODELS ARE MORE
OPTIMISTIC.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...DONAVON
LONG TERM...FAB
AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS JACKSON KY
201 PM EST TUE JAN 27 2015
.UPDATE...
ISSUED AT 201 PM EST TUE JAN 27 2015
SKIES HAVE BEGUN TO SLOWLY CLEAR OUT FROM NORTH TO SOUTH AS THE AREA
OF CLOUD COVER SLOWLY SLIDES SOUTH ASSOCIATED WITH THE WEAK WAVE THAT
DIVED SOUTH THROUGH EASTERN KENTUCKY THIS MORNING. ADJUSTED CLOUD
COVER FOR THIS AND HAVE TAKEN OUT THE MENTION OF FLURRIES FOR THIS.
DID ADJUST THE MAX TEMPS FOR TODAY AS THE CLEAR SKIES WILL ALLOW FOR
SLIGHTLY WARMER TEMPERATURES.
UPDATE ISSUED AT 1101 AM EST TUE JAN 27 2015
CURRENT OBSERVATIONS ARE SHOWING LOW LEVEL CLOUD COVER AND A FEW
FLURRIES MOVING THROUGH EASTERN KENTUCKY BUT MAINLY OVER THE SOUTHERN
PORTION. MUCH OF THE HEAVIER RETURNS ON RADAR HAVE DISSIPATED AND THE
SNOW SHOWER ACTIVITY HAS DWINDLED SIGNIFICANTLY. STILL CAN RULE OUT A
SLIGHT VISIBILITY REDUCTION INTO THIS AFTERNOON WITH SOME FLURRY
ACTIVITY. HAVE UPDATED THE GRIDS AND REMOVED SNOW SHOWER WORDING BUT
WILL CONTINUE TO INCLUDE SOME ISOLATED TO SCATTERED FLURRIES
THROUGH THE AFTERNOON. HAVE ISSUED A NEW ZFP FOR THESE CHANGES BUT
OVERALL THE FORECAST IS ON TRACK.
UPDATE ISSUED AT 725 AM EST TUE JAN 27 2015
A NEW SNOW BAND DEVELOPED OVER THE BLUEGRASS AREA AND HAS NOW SLIPPED
SOUTHEAST INTO OUR CWA RIDING JUST A TAD NORTHEAST OF THE PREVIOUS
ONE. ONLY BELATEDLY DID THE HRRR CATCH ON TO THIS LATEST BAND...
THOUGH. ACCORDINGLY...HAVE UPDATED THE GRIDS TO REFLECT THE SNOW
MOVEMENT AND ADJUSTED THE LIGHT SNOW AMOUNTS. ALSO FINE TUNED
TEMPERATURES AND DEWPOINTS PER THE LATEST OBS AND TRENDS. THESE HAVE
BEEN SENT TO THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 335 AM EST TUE JAN 27 2015
07Z SFC ANALYSIS SHOWS A DEEP AREA OF LOW PRESSURE OFF TO THE
NORTHEAST WHILE LOCALLY THE PRESSURE GRADIENT IS RATHER RELAXED AND
THIS IS LIMITING THE UPSLOPE COMPONENT OF THIS NIGHT/S SNOW THREAT.
THE MAIN BANDS OF SNOW ARE BEING PRIMARILY DRIVEN BY A SFC TROUGH
AXIS SPLITTING THE STATE AND A STREAM OF MID LEVEL ENERGY RUNNING
NORTH NORTHWEST TO THE SOUTH SOUTHEAST OVER PARTS OF CENTRAL AND
EASTERN KENTUCKY. ON RADAR...THIS BAND LINES UP WELL WITH THIS
ENERGY STREAM AND IS ALSO ABLE TO TAP INTO EXTRA MOISTURE FROM LAKE
MICHIGAN. THE SNOW ASSOCIATED WITH THIS HAS BEEN RELATIVELY LIGHT
WITH MOST SITES REPORTING SNOW SEEING 4SM OR BETTER VIS...THOUGH IT
IS LIKELY THAT UNDER THE HIGHEST RADAR RETURNS VIS IS LESS THAN 2
MILES. FOR THESE LOCATIONS...A COUPLE OF TENTHS OF AN INCH OR SO OF
ACCUMULATION WILL BE POSSIBLE WHILE MOST OTHER PLACES WILL SEE JUST A
THICK DUSTING OR LESS. AN SPS IS IN EFFECT FOR THIS AND IT WILL BE
CONTINUED THROUGH DAWN AND THE MORNING RUSH HOUR FOR GOOD MEASURE.
TEMPERATURES...MEANWHILE ARE IN THE MID TO UPPER 20S ACROSS THE AREA
WITH DEWPOINTS A DEGREE OR SO LOWER AND WINDS LIGHT TO CALM.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION
OF THE FORECAST AS A CLOSED LOW DEEPENS OFF THE NEW ENGLAND COAST AND
A STREAM OF ENERGY FLOWS NNW TO SSE OVER KENTUCKY AND INTO THE
BROADER EAST COAST TROUGH TODAY. THIS FLOW WILL BE NUDGED EAST BY A
MODERATELY STRONG RIDGE IN THE SOUTHERN STREAM CROSSING THE SOUTHERN
PLAINS LATER TONIGHT. THIS RIDGE WILL BE PUSHED SOUTH BY A DEVELOPING
TROUGH COMING OUT OF THE CENTRAL ROCKIES AND MOVING INTO THE CENTRAL
PLAINS LATER WEDNESDAY. GIVEN THE GOOD MODEL AGREEMENT HAVE FAVORED
THE HIGHER RESOLUTION HRRR AND NAM12 THROUGH THE FIRST PART OF THE
FORECAST AND A BLEND THEREAFTER.
SENSIBLE WEATHER WILL FEATURE A BATCH OF EARLY MORNING SNOW SHOWERS
TARGETING MAINLY THE CUMBERLAND VALLEY OF EASTERN KENTUCKY. A FEW
FLURRIES WILL THEN LINGER INTO EARLY AFTERNOON FOR FAR SOUTHEAST
PARTS OF THE CWA BEFORE ALSO COMING TO AN END BY EARLY EVENING AS THE
CLOUDS ATTEMPT TO CLEAR. THIS...ALONG WITH SOME CONTINUED CAA FROM
THE EAST COAST STORM...WILL MAKE FOR A CHILLY NIGHT WITH LOWS IN THE
TEENS FOR WEDNESDAY MORNING. DESPITE HIGH PRESSURE PASSING THROUGH...
A BATCH OF LOW CLOUDS COULD DEVELOP OVERNIGHT AND HUG OUR EASTERN
ZONES INTO DAWN WEDNESDAY...WHICH MAY SPARE THESE AREAS THE COLDEST
TEMPS. THIS LOW LEVEL MOISTURE WILL ALSO NEED TO BE WATCHED FOR A
POTENTIAL OF SPOTTY FREEZING DRIZZLE IF THE STRATUS GETS THICK
ENOUGH. FOR NOW...THOUGH...IT LOOKS LIKE THIS WILL NOT BE THE
CASE...BUT THE POTENTIAL IS THERE. OTHERWISE...THE APPROACH OF
ANOTHER NORTHERN PASSING SFC LOW WILL HELP TO WARM THE AREA UP ON
WEDNESDAY WITH TEMPS REBOUNDING INTO THE MID 30S NORTHEAST TO THE
LOWER 40S SOUTHWEST. HOWEVER...HIGH CLOUDS WILL START TO MOVE IN BY
AFTERNOON FROM THE NORTHWEST LIMITING SUNSHINE ONCE ANY LOW CLOUDS
BREAK UP.
USED THE BCCONSSHORT AS A STARTING POINT FOR TEMPERATURES...
DEWPOINTS...AND WINDS THROUGH THIS AFTERNOON BEFORE PLUGGING IN THE
SUPERBLEND THEREAFTER. DID MAKE SOME MINOR...TERRAIN BASED...
ADJUSTMENTS TO HOURLY AND MINIMUM TEMPERATURES TONIGHT. AS FOR
POPS...ENDED UP CLOSE TO A COMBINATION OF THE WETTER MAV AND DRIER
MET TODAY WHILE AGREED WITH THE LOW POPS FROM ALL GUIDANCE TONIGHT
AND WEDNESDAY ACROSS EAST KENTUCKY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 419 AM EST TUE JAN 27 2015
THE PERIOD BEGINS WITH HIGH PRESSURE CENTERED TO THE NORTH AND EAST
WITH SOME WEAK UPPER LEVEL RIDGING ACROSS THE REGION. EYES TURN
QUICKLY TO APPROACHING SURFACE LOW ACROSS THE MIDWEST THAT IS
FORECAST TO PROGRESS EAST INTO THE GREAT LAKES. A COLD FRONT
EXTENDING SOUTH FROM THE LOW WILL BE THE DRIVER FOR CHANCES OF PRECIP
AS WE MOVE INTO THURSDAY MORNING INTO THURSDAY NIGHT. THEREFORE
WEDNESDAY NIGHT WILL BE MET WITH INCREASING CLOUDS AND CHANCES OF
PRECIP INCREASING AS WE MOVE TOWARD DAYLIGHT ON THURSDAY. THE PRECIP
WILL BRING A CHANCES OF SNOW OR RAIN/SNOW MIX THURSDAY MORNING BEFORE
CHANGING TO ALL RAIN LATE MORNING INTO THURSDAY AS WARMER AIR MAKES
ITS WAY INTO THE REGION. THIS IS ALSO EVIDENT IN THE SOUNDS AS DRYER
AIR IS SEEN IN THE UPPER LEVEL LEADING TO LESS ICE BY THURSDAY
AFTERNOON. OTHERWISE THIS LOW PRESSURE SYSTEM AND ASSOCIATED
SHORTWAVE WILL MOVE EAST THURSDAY NIGHT WITH LOW DEEPENING ACROSS THE
NORTHEAST US. HERE WE SWITCH TO WEST TO NORTHWEST FLOW AND THEREFORE
HAVE KEPT SOME POPS ACROSS EAST AND SOUTHEAST THURSDAY NIGHT INTO
EARLY FRIDAY. THIS WILL LIKELY MIX WITH OR CHANGE TO SNOW AS WE MOVE
THROUGH THE NIGHT. GIVEN LIMITED MOISTURE AT THIS POINT WOULD THINK
LITTLE TO ANY ACCUMULATIONS WOULD BE EXPECTED WITH BEST CHANCES
ACROSS THE HIGHER TERRAIN.
MOVING INTO FRIDAY EXPECT DECREASING CLOUDS AND HIGH PRESSURE TO DROP
SOUTH OUT OF THE UPPER PLAINS. THIS WILL USHER IN GENERALLY BELOW
NORMAL TEMPS FOR FRIDAY. THE QUESTION REMAINS FRIDAY NIGHT AS TO HOW
MUCH THE TEMPS BOTTOM OUT. RIGHT NOW WOULD SEEM LIKE BEST CHANCES FOR
DECOUPLING WOULD BE ACROSS THE NORTH AND FAR EASTERN PORTIONS OF THE
CWA. DID INTRODUCE SOME TEENS TO BETTER MATCH NEIGHBORING OFFICES.
AFTER THIS THE HIGH PRESSURE MOVES EAST WITH RETURN FLOW SATURDAY
WITH TEMPERATURES GENERALLY ABLE TO REBOUND INTO THE UPPER 30S TO
LOWER 40S.
THEN FOCUS SHIFTS TO NEXT SYSTEM DEVELOPING ACROSS THE SOUTHWEST US
AND PLAINS STATES. THIS LOW PRESSURE WILL EVENTUALLY GET PICK UP BY
NORTHERN STREAM SHORTWAVE AND PROGRESS EAST INTO THE MISSISSIPPI
RIVER VALLEY LATE SATURDAY NIGHT. WE DO INTRODUCE SLIGHT TO CHANCE
POPS SATURDAY NIGHT WITH SOME OF THIS MIXING WITH SNOW AND RAIN
BEFORE CHANGING TO ALL RAIN SUNDAY AS LOW PRESSURE DEEPENS ALONG AND
NEAR THE OHIO RIVER VALLEY THROUGH THE DAY SUNDAY. THIS RAIN WILL
ONCE AGAIN TRANSITION TO MIX AND SNOW SUNDAY EVENING AND SUNDAY
NIGHT FROM NORTH TO SOUTH AS COLDER AIR FILTERS INTO THE REGION
BEHIND THIS LOW. GIVEN THE MORE NORTHERN TRACK OF THIS SURFACE LOW
AND BEST QPF AHEAD OF COLDER AIR WOULD THINK THAT ACCUMULATIONS WOULD
BE LIGHT IN TERMS OF ANY SNOW WE ARE ABLE TO GET. KEEP IN MIND THIS
IS STILL IN THE FARTHER REACHES OF THE LONG TERM FORECAST AND WILL
HAVE TO BE FINE TUNED AS WE GET CLOSER TO THE EVENT. AFTER THIS
SYSTEM MOVES EAST WITH SOME NW FLOW SNOW SHOWERS CONTINUING ACROSS
THE EAST AND SOUTHEAST. OTHERWISE COLDER AIR CONTINUES TO FILTER INTO
THE REGION WITH TEMPERATURES STRUGGLING TO MAKE IT ABOVE FREEZING
MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1255 PM EST TUE JAN 27 2015
SKIES ARE BEGINNING TO CLEAR FROM NORTH TO SOUTH ACROSS THE CWA...
WITH CLEAR SKIES BEING REPORTED AT THE SYM/SJS TAF SITES. IN THE
SOUTHERN AND SOUTHWEST PORTIONS OF OUR CWA...EXPECT CIELINGS TO
GRADUALLY LIFT AND CONDITIONS TO IMPROVE FROM MVFR TO VFR THROUGHOUT
THE AFTERNOON/EVENING HOURS. BY 23Z... ALL TAF SITES SHOULD SEE VFR
CONDITIONS. WEATHER WILL REMAIN DRY THROUGH TOMORROW AFTERNOON. WINDS
WILL GENERALLY BE LIGHT AND VARIABLE THROUGH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...GREIF
LONG TERM...DJ
AVIATION...JVM
AREA FORECAST DISCUSSION
NWS JACKSON KY
1255 PM EST TUE JAN 27 2015
.UPDATE...
ISSUED AT 1101 AM EST TUE JAN 27 2015
CURRENT OBSERVATIONS ARE SHOWING LOW LEVEL CLOUD COVER AND A FEW
FLURRIES MOVING THROUGH EASTERN KENTUCKY BUT MAINLY OVER THE SOUTHERN
PORTION. MUCH OF THE HEAVIER RETURNS ON RADAR HAVE DISSIPATED AND THE
SNOW SHOWER ACTIVITY HAS DWINDLED SIGNIFICANTLY. STILL CAN RULE OUT A
SLIGHT VISIBILITY REDUCTION INTO THIS AFTERNOON WITH SOME FLURRY
ACTIVITY. HAVE UPDATED THE GRIDS AND REMOVED SNOW SHOWER WORDING BUT
WILL CONTINUE TO INCLUDE SOME ISOLATED TO SCATTERED FLURRIES
THROUGH THE AFTERNOON. HAVE ISSUED A NEW ZFP FOR THESE CHANGES BUT
OVERALL THE FORECAST IS ON TRACK.
UPDATE ISSUED AT 725 AM EST TUE JAN 27 2015
A NEW SNOW BAND DEVELOPED OVER THE BLUEGRASS AREA AND HAS NOW SLIPPED
SOUTHEAST INTO OUR CWA RIDING JUST A TAD NORTHEAST OF THE PREVIOUS
ONE. ONLY BELATEDLY DID THE HRRR CATCH ON TO THIS LATEST BAND...
THOUGH. ACCORDINGLY...HAVE UPDATED THE GRIDS TO REFLECT THE SNOW
MOVEMENT AND ADJUSTED THE LIGHT SNOW AMOUNTS. ALSO FINE TUNED
TEMPERATURES AND DEWPOINTS PER THE LATEST OBS AND TRENDS. THESE HAVE
BEEN SENT TO THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 335 AM EST TUE JAN 27 2015
07Z SFC ANALYSIS SHOWS A DEEP AREA OF LOW PRESSURE OFF TO THE
NORTHEAST WHILE LOCALLY THE PRESSURE GRADIENT IS RATHER RELAXED AND
THIS IS LIMITING THE UPSLOPE COMPONENT OF THIS NIGHT/S SNOW THREAT.
THE MAIN BANDS OF SNOW ARE BEING PRIMARILY DRIVEN BY A SFC TROUGH
AXIS SPLITTING THE STATE AND A STREAM OF MID LEVEL ENERGY RUNNING
NORTH NORTHWEST TO THE SOUTH SOUTHEAST OVER PARTS OF CENTRAL AND
EASTERN KENTUCKY. ON RADAR...THIS BAND LINES UP WELL WITH THIS
ENERGY STREAM AND IS ALSO ABLE TO TAP INTO EXTRA MOISTURE FROM LAKE
MICHIGAN. THE SNOW ASSOCIATED WITH THIS HAS BEEN RELATIVELY LIGHT
WITH MOST SITES REPORTING SNOW SEEING 4SM OR BETTER VIS...THOUGH IT
IS LIKELY THAT UNDER THE HIGHEST RADAR RETURNS VIS IS LESS THAN 2
MILES. FOR THESE LOCATIONS...A COUPLE OF TENTHS OF AN INCH OR SO OF
ACCUMULATION WILL BE POSSIBLE WHILE MOST OTHER PLACES WILL SEE JUST A
THICK DUSTING OR LESS. AN SPS IS IN EFFECT FOR THIS AND IT WILL BE
CONTINUED THROUGH DAWN AND THE MORNING RUSH HOUR FOR GOOD MEASURE.
TEMPERATURES...MEANWHILE ARE IN THE MID TO UPPER 20S ACROSS THE AREA
WITH DEWPOINTS A DEGREE OR SO LOWER AND WINDS LIGHT TO CALM.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION
OF THE FORECAST AS A CLOSED LOW DEEPENS OFF THE NEW ENGLAND COAST AND
A STREAM OF ENERGY FLOWS NNW TO SSE OVER KENTUCKY AND INTO THE
BROADER EAST COAST TROUGH TODAY. THIS FLOW WILL BE NUDGED EAST BY A
MODERATELY STRONG RIDGE IN THE SOUTHERN STREAM CROSSING THE SOUTHERN
PLAINS LATER TONIGHT. THIS RIDGE WILL BE PUSHED SOUTH BY A DEVELOPING
TROUGH COMING OUT OF THE CENTRAL ROCKIES AND MOVING INTO THE CENTRAL
PLAINS LATER WEDNESDAY. GIVEN THE GOOD MODEL AGREEMENT HAVE FAVORED
THE HIGHER RESOLUTION HRRR AND NAM12 THROUGH THE FIRST PART OF THE
FORECAST AND A BLEND THEREAFTER.
SENSIBLE WEATHER WILL FEATURE A BATCH OF EARLY MORNING SNOW SHOWERS
TARGETING MAINLY THE CUMBERLAND VALLEY OF EASTERN KENTUCKY. A FEW
FLURRIES WILL THEN LINGER INTO EARLY AFTERNOON FOR FAR SOUTHEAST
PARTS OF THE CWA BEFORE ALSO COMING TO AN END BY EARLY EVENING AS THE
CLOUDS ATTEMPT TO CLEAR. THIS...ALONG WITH SOME CONTINUED CAA FROM
THE EAST COAST STORM...WILL MAKE FOR A CHILLY NIGHT WITH LOWS IN THE
TEENS FOR WEDNESDAY MORNING. DESPITE HIGH PRESSURE PASSING THROUGH...
A BATCH OF LOW CLOUDS COULD DEVELOP OVERNIGHT AND HUG OUR EASTERN
ZONES INTO DAWN WEDNESDAY...WHICH MAY SPARE THESE AREAS THE COLDEST
TEMPS. THIS LOW LEVEL MOISTURE WILL ALSO NEED TO BE WATCHED FOR A
POTENTIAL OF SPOTTY FREEZING DRIZZLE IF THE STRATUS GETS THICK
ENOUGH. FOR NOW...THOUGH...IT LOOKS LIKE THIS WILL NOT BE THE
CASE...BUT THE POTENTIAL IS THERE. OTHERWISE...THE APPROACH OF
ANOTHER NORTHERN PASSING SFC LOW WILL HELP TO WARM THE AREA UP ON
WEDNESDAY WITH TEMPS REBOUNDING INTO THE MID 30S NORTHEAST TO THE
LOWER 40S SOUTHWEST. HOWEVER...HIGH CLOUDS WILL START TO MOVE IN BY
AFTERNOON FROM THE NORTHWEST LIMITING SUNSHINE ONCE ANY LOW CLOUDS
BREAK UP.
USED THE BCCONSSHORT AS A STARTING POINT FOR TEMPERATURES...
DEWPOINTS...AND WINDS THROUGH THIS AFTERNOON BEFORE PLUGGING IN THE
SUPERBLEND THEREAFTER. DID MAKE SOME MINOR...TERRAIN BASED...
ADJUSTMENTS TO HOURLY AND MINIMUM TEMPERATURES TONIGHT. AS FOR
POPS...ENDED UP CLOSE TO A COMBINATION OF THE WETTER MAV AND DRIER
MET TODAY WHILE AGREED WITH THE LOW POPS FROM ALL GUIDANCE TONIGHT
AND WEDNESDAY ACROSS EAST KENTUCKY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 419 AM EST TUE JAN 27 2015
THE PERIOD BEGINS WITH HIGH PRESSURE CENTERED TO THE NORTH AND EAST
WITH SOME WEAK UPPER LEVEL RIDGING ACROSS THE REGION. EYES TURN
QUICKLY TO APPROACHING SURFACE LOW ACROSS THE MIDWEST THAT IS
FORECAST TO PROGRESS EAST INTO THE GREAT LAKES. A COLD FRONT
EXTENDING SOUTH FROM THE LOW WILL BE THE DRIVER FOR CHANCES OF PRECIP
AS WE MOVE INTO THURSDAY MORNING INTO THURSDAY NIGHT. THEREFORE
WEDNESDAY NIGHT WILL BE MET WITH INCREASING CLOUDS AND CHANCES OF
PRECIP INCREASING AS WE MOVE TOWARD DAYLIGHT ON THURSDAY. THE PRECIP
WILL BRING A CHANCES OF SNOW OR RAIN/SNOW MIX THURSDAY MORNING BEFORE
CHANGING TO ALL RAIN LATE MORNING INTO THURSDAY AS WARMER AIR MAKES
ITS WAY INTO THE REGION. THIS IS ALSO EVIDENT IN THE SOUNDS AS DRYER
AIR IS SEEN IN THE UPPER LEVEL LEADING TO LESS ICE BY THURSDAY
AFTERNOON. OTHERWISE THIS LOW PRESSURE SYSTEM AND ASSOCIATED
SHORTWAVE WILL MOVE EAST THURSDAY NIGHT WITH LOW DEEPENING ACROSS THE
NORTHEAST US. HERE WE SWITCH TO WEST TO NORTHWEST FLOW AND THEREFORE
HAVE KEPT SOME POPS ACROSS EAST AND SOUTHEAST THURSDAY NIGHT INTO
EARLY FRIDAY. THIS WILL LIKELY MIX WITH OR CHANGE TO SNOW AS WE MOVE
THROUGH THE NIGHT. GIVEN LIMITED MOISTURE AT THIS POINT WOULD THINK
LITTLE TO ANY ACCUMULATIONS WOULD BE EXPECTED WITH BEST CHANCES
ACROSS THE HIGHER TERRAIN.
MOVING INTO FRIDAY EXPECT DECREASING CLOUDS AND HIGH PRESSURE TO DROP
SOUTH OUT OF THE UPPER PLAINS. THIS WILL USHER IN GENERALLY BELOW
NORMAL TEMPS FOR FRIDAY. THE QUESTION REMAINS FRIDAY NIGHT AS TO HOW
MUCH THE TEMPS BOTTOM OUT. RIGHT NOW WOULD SEEM LIKE BEST CHANCES FOR
DECOUPLING WOULD BE ACROSS THE NORTH AND FAR EASTERN PORTIONS OF THE
CWA. DID INTRODUCE SOME TEENS TO BETTER MATCH NEIGHBORING OFFICES.
AFTER THIS THE HIGH PRESSURE MOVES EAST WITH RETURN FLOW SATURDAY
WITH TEMPERATURES GENERALLY ABLE TO REBOUND INTO THE UPPER 30S TO
LOWER 40S.
THEN FOCUS SHIFTS TO NEXT SYSTEM DEVELOPING ACROSS THE SOUTHWEST US
AND PLAINS STATES. THIS LOW PRESSURE WILL EVENTUALLY GET PICK UP BY
NORTHERN STREAM SHORTWAVE AND PROGRESS EAST INTO THE MISSISSIPPI
RIVER VALLEY LATE SATURDAY NIGHT. WE DO INTRODUCE SLIGHT TO CHANCE
POPS SATURDAY NIGHT WITH SOME OF THIS MIXING WITH SNOW AND RAIN
BEFORE CHANGING TO ALL RAIN SUNDAY AS LOW PRESSURE DEEPENS ALONG AND
NEAR THE OHIO RIVER VALLEY THROUGH THE DAY SUNDAY. THIS RAIN WILL
ONCE AGAIN TRANSITION TO MIX AND SNOW SUNDAY EVENING AND SUNDAY
NIGHT FROM NORTH TO SOUTH AS COLDER AIR FILTERS INTO THE REGION
BEHIND THIS LOW. GIVEN THE MORE NORTHERN TRACK OF THIS SURFACE LOW
AND BEST QPF AHEAD OF COLDER AIR WOULD THINK THAT ACCUMULATIONS WOULD
BE LIGHT IN TERMS OF ANY SNOW WE ARE ABLE TO GET. KEEP IN MIND THIS
IS STILL IN THE FARTHER REACHES OF THE LONG TERM FORECAST AND WILL
HAVE TO BE FINE TUNED AS WE GET CLOSER TO THE EVENT. AFTER THIS
SYSTEM MOVES EAST WITH SOME NW FLOW SNOW SHOWERS CONTINUING ACROSS
THE EAST AND SOUTHEAST. OTHERWISE COLDER AIR CONTINUES TO FILTER INTO
THE REGION WITH TEMPERATURES STRUGGLING TO MAKE IT ABOVE FREEZING
MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1255 PM EST TUE JAN 27 2015
SKIES ARE BEGINNING TO CLEAR FROM NORTH TO SOUTH ACROSS THE CWA...
WITH CLEAR SKIES BEING REPORTED AT THE SYM/SJS TAF SITES. IN THE
SOUTHERN AND SOUTHWEST PORTIONS OF OUR CWA...EXPECT CIELINGS TO
GRADUALLY LIFT AND CONDITIONS TO IMPROVE FROM MVFR TO VFR THROUGHOUT
THE AFTERNOON/EVENING HOURS. BY 23Z... ALL TAF SITES SHOULD SEE VFR
CONDITIONS. WEATHER WILL REMAIN DRY THROUGH TOMORROW AFTERNOON. WINDS
WILL GENERALLY BE LIGHT AND VARIABLE THROUGH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...GREIF
LONG TERM...DJ
AVIATION...JVM
AREA FORECAST DISCUSSION
NWS JACKSON KY
1102 AM EST TUE JAN 27 2015
.UPDATE...
ISSUED AT 1101 AM EST TUE JAN 27 2015
CURRENT OBSERVATIONS ARE SHOWING LOW LEVEL CLOUD COVER AND A FEW
FLURRIES MOVING THROUGH EASTERN KENTUCKY BUT MAINLY OVER THE SOUTHERN
PORTION. MUCH OF THE HEAVIER RETURNS ON RADAR HAVE DISSIPATED AND THE
SNOW SHOWER ACTIVITY HAS DWINDLED SIGNIFICANTLY. STILL CAN RULE OUT A
SLIGHT VISIBILITY REDUCTION INTO THIS AFTERNOON WITH SOME FLURRY
ACTIVITY. HAVE UPDATED THE GRIDS AND REMOVED SNOW SHOWER WORDING BUT
WILL CONTINUE TO INCLUDE SOME ISOLATED TO SCATTERED FLURRIES
THROUGH THE AFTERNOON. HAVE ISSUED A NEW ZFP FOR THESE CHANGES BUT
OVERALL THE FORECAST IS ON TRACK.
UPDATE ISSUED AT 725 AM EST TUE JAN 27 2015
A NEW SNOW BAND DEVELOPED OVER THE BLUEGRASS AREA AND HAS NOW SLIPPED
SOUTHEAST INTO OUR CWA RIDING JUST A TAD NORTHEAST OF THE PREVIOUS
ONE. ONLY BELATEDLY DID THE HRRR CATCH ON TO THIS LATEST BAND...
THOUGH. ACCORDINGLY...HAVE UPDATED THE GRIDS TO REFLECT THE SNOW
MOVEMENT AND ADJUSTED THE LIGHT SNOW AMOUNTS. ALSO FINE TUNED
TEMPERATURES AND DEWPOINTS PER THE LATEST OBS AND TRENDS. THESE HAVE
BEEN SENT TO THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 335 AM EST TUE JAN 27 2015
07Z SFC ANALYSIS SHOWS A DEEP AREA OF LOW PRESSURE OFF TO THE
NORTHEAST WHILE LOCALLY THE PRESSURE GRADIENT IS RATHER RELAXED AND
THIS IS LIMITING THE UPSLOPE COMPONENT OF THIS NIGHT/S SNOW THREAT.
THE MAIN BANDS OF SNOW ARE BEING PRIMARILY DRIVEN BY A SFC TROUGH
AXIS SPLITTING THE STATE AND A STREAM OF MID LEVEL ENERGY RUNNING
NORTH NORTHWEST TO THE SOUTH SOUTHEAST OVER PARTS OF CENTRAL AND
EASTERN KENTUCKY. ON RADAR...THIS BAND LINES UP WELL WITH THIS
ENERGY STREAM AND IS ALSO ABLE TO TAP INTO EXTRA MOISTURE FROM LAKE
MICHIGAN. THE SNOW ASSOCIATED WITH THIS HAS BEEN RELATIVELY LIGHT
WITH MOST SITES REPORTING SNOW SEEING 4SM OR BETTER VIS...THOUGH IT
IS LIKELY THAT UNDER THE HIGHEST RADAR RETURNS VIS IS LESS THAN 2
MILES. FOR THESE LOCATIONS...A COUPLE OF TENTHS OF AN INCH OR SO OF
ACCUMULATION WILL BE POSSIBLE WHILE MOST OTHER PLACES WILL SEE JUST A
THICK DUSTING OR LESS. AN SPS IS IN EFFECT FOR THIS AND IT WILL BE
CONTINUED THROUGH DAWN AND THE MORNING RUSH HOUR FOR GOOD MEASURE.
TEMPERATURES...MEANWHILE ARE IN THE MID TO UPPER 20S ACROSS THE AREA
WITH DEWPOINTS A DEGREE OR SO LOWER AND WINDS LIGHT TO CALM.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION
OF THE FORECAST AS A CLOSED LOW DEEPENS OFF THE NEW ENGLAND COAST AND
A STREAM OF ENERGY FLOWS NNW TO SSE OVER KENTUCKY AND INTO THE
BROADER EAST COAST TROUGH TODAY. THIS FLOW WILL BE NUDGED EAST BY A
MODERATELY STRONG RIDGE IN THE SOUTHERN STREAM CROSSING THE SOUTHERN
PLAINS LATER TONIGHT. THIS RIDGE WILL BE PUSHED SOUTH BY A DEVELOPING
TROUGH COMING OUT OF THE CENTRAL ROCKIES AND MOVING INTO THE CENTRAL
PLAINS LATER WEDNESDAY. GIVEN THE GOOD MODEL AGREEMENT HAVE FAVORED
THE HIGHER RESOLUTION HRRR AND NAM12 THROUGH THE FIRST PART OF THE
FORECAST AND A BLEND THEREAFTER.
SENSIBLE WEATHER WILL FEATURE A BATCH OF EARLY MORNING SNOW SHOWERS
TARGETING MAINLY THE CUMBERLAND VALLEY OF EASTERN KENTUCKY. A FEW
FLURRIES WILL THEN LINGER INTO EARLY AFTERNOON FOR FAR SOUTHEAST
PARTS OF THE CWA BEFORE ALSO COMING TO AN END BY EARLY EVENING AS THE
CLOUDS ATTEMPT TO CLEAR. THIS...ALONG WITH SOME CONTINUED CAA FROM
THE EAST COAST STORM...WILL MAKE FOR A CHILLY NIGHT WITH LOWS IN THE
TEENS FOR WEDNESDAY MORNING. DESPITE HIGH PRESSURE PASSING THROUGH...
A BATCH OF LOW CLOUDS COULD DEVELOP OVERNIGHT AND HUG OUR EASTERN
ZONES INTO DAWN WEDNESDAY...WHICH MAY SPARE THESE AREAS THE COLDEST
TEMPS. THIS LOW LEVEL MOISTURE WILL ALSO NEED TO BE WATCHED FOR A
POTENTIAL OF SPOTTY FREEZING DRIZZLE IF THE STRATUS GETS THICK
ENOUGH. FOR NOW...THOUGH...IT LOOKS LIKE THIS WILL NOT BE THE
CASE...BUT THE POTENTIAL IS THERE. OTHERWISE...THE APPROACH OF
ANOTHER NORTHERN PASSING SFC LOW WILL HELP TO WARM THE AREA UP ON
WEDNESDAY WITH TEMPS REBOUNDING INTO THE MID 30S NORTHEAST TO THE
LOWER 40S SOUTHWEST. HOWEVER...HIGH CLOUDS WILL START TO MOVE IN BY
AFTERNOON FROM THE NORTHWEST LIMITING SUNSHINE ONCE ANY LOW CLOUDS
BREAK UP.
USED THE BCCONSSHORT AS A STARTING POINT FOR TEMPERATURES...
DEWPOINTS...AND WINDS THROUGH THIS AFTERNOON BEFORE PLUGGING IN THE
SUPERBLEND THEREAFTER. DID MAKE SOME MINOR...TERRAIN BASED...
ADJUSTMENTS TO HOURLY AND MINIMUM TEMPERATURES TONIGHT. AS FOR
POPS...ENDED UP CLOSE TO A COMBINATION OF THE WETTER MAV AND DRIER
MET TODAY WHILE AGREED WITH THE LOW POPS FROM ALL GUIDANCE TONIGHT
AND WEDNESDAY ACROSS EAST KENTUCKY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 419 AM EST TUE JAN 27 2015
THE PERIOD BEGINS WITH HIGH PRESSURE CENTERED TO THE NORTH AND EAST
WITH SOME WEAK UPPER LEVEL RIDGING ACROSS THE REGION. EYES TURN
QUICKLY TO APPROACHING SURFACE LOW ACROSS THE MIDWEST THAT IS
FORECAST TO PROGRESS EAST INTO THE GREAT LAKES. A COLD FRONT
EXTENDING SOUTH FROM THE LOW WILL BE THE DRIVER FOR CHANCES OF PRECIP
AS WE MOVE INTO THURSDAY MORNING INTO THURSDAY NIGHT. THEREFORE
WEDNESDAY NIGHT WILL BE MET WITH INCREASING CLOUDS AND CHANCES OF
PRECIP INCREASING AS WE MOVE TOWARD DAYLIGHT ON THURSDAY. THE PRECIP
WILL BRING A CHANCES OF SNOW OR RAIN/SNOW MIX THURSDAY MORNING BEFORE
CHANGING TO ALL RAIN LATE MORNING INTO THURSDAY AS WARMER AIR MAKES
ITS WAY INTO THE REGION. THIS IS ALSO EVIDENT IN THE SOUNDS AS DRYER
AIR IS SEEN IN THE UPPER LEVEL LEADING TO LESS ICE BY THURSDAY
AFTERNOON. OTHERWISE THIS LOW PRESSURE SYSTEM AND ASSOCIATED
SHORTWAVE WILL MOVE EAST THURSDAY NIGHT WITH LOW DEEPENING ACROSS THE
NORTHEAST US. HERE WE SWITCH TO WEST TO NORTHWEST FLOW AND THEREFORE
HAVE KEPT SOME POPS ACROSS EAST AND SOUTHEAST THURSDAY NIGHT INTO
EARLY FRIDAY. THIS WILL LIKELY MIX WITH OR CHANGE TO SNOW AS WE MOVE
THROUGH THE NIGHT. GIVEN LIMITED MOISTURE AT THIS POINT WOULD THINK
LITTLE TO ANY ACCUMULATIONS WOULD BE EXPECTED WITH BEST CHANCES
ACROSS THE HIGHER TERRAIN.
MOVING INTO FRIDAY EXPECT DECREASING CLOUDS AND HIGH PRESSURE TO DROP
SOUTH OUT OF THE UPPER PLAINS. THIS WILL USHER IN GENERALLY BELOW
NORMAL TEMPS FOR FRIDAY. THE QUESTION REMAINS FRIDAY NIGHT AS TO HOW
MUCH THE TEMPS BOTTOM OUT. RIGHT NOW WOULD SEEM LIKE BEST CHANCES FOR
DECOUPLING WOULD BE ACROSS THE NORTH AND FAR EASTERN PORTIONS OF THE
CWA. DID INTRODUCE SOME TEENS TO BETTER MATCH NEIGHBORING OFFICES.
AFTER THIS THE HIGH PRESSURE MOVES EAST WITH RETURN FLOW SATURDAY
WITH TEMPERATURES GENERALLY ABLE TO REBOUND INTO THE UPPER 30S TO
LOWER 40S.
THEN FOCUS SHIFTS TO NEXT SYSTEM DEVELOPING ACROSS THE SOUTHWEST US
AND PLAINS STATES. THIS LOW PRESSURE WILL EVENTUALLY GET PICK UP BY
NORTHERN STREAM SHORTWAVE AND PROGRESS EAST INTO THE MISSISSIPPI
RIVER VALLEY LATE SATURDAY NIGHT. WE DO INTRODUCE SLIGHT TO CHANCE
POPS SATURDAY NIGHT WITH SOME OF THIS MIXING WITH SNOW AND RAIN
BEFORE CHANGING TO ALL RAIN SUNDAY AS LOW PRESSURE DEEPENS ALONG AND
NEAR THE OHIO RIVER VALLEY THROUGH THE DAY SUNDAY. THIS RAIN WILL
ONCE AGAIN TRANSITION TO MIX AND SNOW SUNDAY EVENING AND SUNDAY
NIGHT FROM NORTH TO SOUTH AS COLDER AIR FILTERS INTO THE REGION
BEHIND THIS LOW. GIVEN THE MORE NORTHERN TRACK OF THIS SURFACE LOW
AND BEST QPF AHEAD OF COLDER AIR WOULD THINK THAT ACCUMULATIONS WOULD
BE LIGHT IN TERMS OF ANY SNOW WE ARE ABLE TO GET. KEEP IN MIND THIS
IS STILL IN THE FARTHER REACHES OF THE LONG TERM FORECAST AND WILL
HAVE TO BE FINE TUNED AS WE GET CLOSER TO THE EVENT. AFTER THIS
SYSTEM MOVES EAST WITH SOME NW FLOW SNOW SHOWERS CONTINUING ACROSS
THE EAST AND SOUTHEAST. OTHERWISE COLDER AIR CONTINUES TO FILTER INTO
THE REGION WITH TEMPERATURES STRUGGLING TO MAKE IT ABOVE FREEZING
MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 705 AM EST TUE JAN 27 2015
A STREAM OF SHORTWAVE ENERGY ALOFT WILL KEEP THE CHANCES OF SNOW IN
THE FORECAST THROUGH MID MORNING FOR MUCH OF EASTERN KENTUCKY. THE
EARLIER BANDS OF LIGHT SNOW SET UP MAINLY OVER THE SOUTHWEST PORTION
OF THE FORECAST AREA...BUT THE NEXT BATCH...AND LIKELY LAST ONE...
LOOKS TO PASS THROUGH THE AREA MORE TO THE NORTHEAST OF THE EARLIER
ONES WITH A BETTER CHANCE OF AFFECTING THE JKL/SYM/SJS TAF SITES.
HAVE UPDATED THESE WITH A TEMPO FOR SOME MVFR AND IFR CIGS AND MVFR
VIS WITH ANY SNOW SHOWERS THROUGH MID MORNING. THE REST OF THE AREA
WILL SEE THEIR CURRENT IFR CIGS IMPROVE TO MVFR SHORTLY AND THEN VFR
LIKELY BY 17Z. LOOKING AT THE TIME HEIGHT SERIES FOR TONIGHT DECIDED
TO ADD SOME IFR STRATUS IN THE EASTERN TAF SITES IN THE PREDAWN
HOURS. WINDS WILL GENERALLY BE LIGHT AND VARIABLE THROUGH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...GREIF
LONG TERM...DJ
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
725 AM EST TUE JAN 27 2015
.UPDATE...
ISSUED AT 725 AM EST TUE JAN 27 2015
A NEW SNOW BAND DEVELOPED OVER THE BLUEGRASS AREA AND HAS NOW SLIPPED
SOUTHEAST INTO OUR CWA RIDING JUST A TAD NORTHEAST OF THE PREVIOUS
ONE. ONLY BELATEDLY DID THE HRRR CATCH ON TO THIS LATEST BAND...
THOUGH. ACCORDINGLY...HAVE UPDATED THE GRIDS TO REFLECT THE SNOW
MOVEMENT AND ADJUSTED THE LIGHT SNOW AMOUNTS. ALSO FINE TUNED
TEMPERATURES AND DEWPOINTS PER THE LATEST OBS AND TRENDS. THESE HAVE
BEEN SENT TO THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 335 AM EST TUE JAN 27 2015
07Z SFC ANALYSIS SHOWS A DEEP AREA OF LOW PRESSURE OFF TO THE
NORTHEAST WHILE LOCALLY THE PRESSURE GRADIENT IS RATHER RELAXED AND
THIS IS LIMITING THE UPSLOPE COMPONENT OF THIS NIGHT/S SNOW THREAT.
THE MAIN BANDS OF SNOW ARE BEING PRIMARILY DRIVEN BY A SFC TROUGH
AXIS SPLITTING THE STATE AND A STREAM OF MID LEVEL ENERGY RUNNING
NORTH NORTHWEST TO THE SOUTH SOUTHEAST OVER PARTS OF CENTRAL AND
EASTERN KENTUCKY. ON RADAR...THIS BAND LINES UP WELL WITH THIS
ENERGY STREAM AND IS ALSO ABLE TO TAP INTO EXTRA MOISTURE FROM LAKE
MICHIGAN. THE SNOW ASSOCIATED WITH THIS HAS BEEN RELATIVELY LIGHT
WITH MOST SITES REPORTING SNOW SEEING 4SM OR BETTER VIS...THOUGH IT
IS LIKELY THAT UNDER THE HIGHEST RADAR RETURNS VIS IS LESS THAN 2
MILES. FOR THESE LOCATIONS...A COUPLE OF TENTHS OF AN INCH OR SO OF
ACCUMULATION WILL BE POSSIBLE WHILE MOST OTHER PLACES WILL SEE JUST A
THICK DUSTING OR LESS. AN SPS IS IN EFFECT FOR THIS AND IT WILL BE
CONTINUED THROUGH DAWN AND THE MORNING RUSH HOUR FOR GOOD MEASURE.
TEMPERATURES...MEANWHILE ARE IN THE MID TO UPPER 20S ACROSS THE AREA
WITH DEWPOINTS A DEGREE OR SO LOWER AND WINDS LIGHT TO CALM.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION
OF THE FORECAST AS A CLOSED LOW DEEPENS OFF THE NEW ENGLAND COAST AND
A STREAM OF ENERGY FLOWS NNW TO SSE OVER KENTUCKY AND INTO THE
BROADER EAST COAST TROUGH TODAY. THIS FLOW WILL BE NUDGED EAST BY A
MODERATELY STRONG RIDGE IN THE SOUTHERN STREAM CROSSING THE SOUTHERN
PLAINS LATER TONIGHT. THIS RIDGE WILL BE PUSHED SOUTH BY A DEVELOPING
TROUGH COMING OUT OF THE CENTRAL ROCKIES AND MOVING INTO THE CENTRAL
PLAINS LATER WEDNESDAY. GIVEN THE GOOD MODEL AGREEMENT HAVE FAVORED
THE HIGHER RESOLUTION HRRR AND NAM12 THROUGH THE FIRST PART OF THE
FORECAST AND A BLEND THEREAFTER.
SENSIBLE WEATHER WILL FEATURE A BATCH OF EARLY MORNING SNOW SHOWERS
TARGETING MAINLY THE CUMBERLAND VALLEY OF EASTERN KENTUCKY. A FEW
FLURRIES WILL THEN LINGER INTO EARLY AFTERNOON FOR FAR SOUTHEAST
PARTS OF THE CWA BEFORE ALSO COMING TO AN END BY EARLY EVENING AS THE
CLOUDS ATTEMPT TO CLEAR. THIS...ALONG WITH SOME CONTINUED CAA FROM
THE EAST COAST STORM...WILL MAKE FOR A CHILLY NIGHT WITH LOWS IN THE
TEENS FOR WEDNESDAY MORNING. DESPITE HIGH PRESSURE PASSING THROUGH...
A BATCH OF LOW CLOUDS COULD DEVELOP OVERNIGHT AND HUG OUR EASTERN
ZONES INTO DAWN WEDNESDAY...WHICH MAY SPARE THESE AREAS THE COLDEST
TEMPS. THIS LOW LEVEL MOISTURE WILL ALSO NEED TO BE WATCHED FOR A
POTENTIAL OF SPOTTY FREEZING DRIZZLE IF THE STRATUS GETS THICK
ENOUGH. FOR NOW...THOUGH...IT LOOKS LIKE THIS WILL NOT BE THE
CASE...BUT THE POTENTIAL IS THERE. OTHERWISE...THE APPROACH OF
ANOTHER NORTHERN PASSING SFC LOW WILL HELP TO WARM THE AREA UP ON
WEDNESDAY WITH TEMPS REBOUNDING INTO THE MID 30S NORTHEAST TO THE
LOWER 40S SOUTHWEST. HOWEVER...HIGH CLOUDS WILL START TO MOVE IN BY
AFTERNOON FROM THE NORTHWEST LIMITING SUNSHINE ONCE ANY LOW CLOUDS
BREAK UP.
USED THE BCCONSSHORT AS A STARTING POINT FOR TEMPERATURES...
DEWPOINTS...AND WINDS THROUGH THIS AFTERNOON BEFORE PLUGGING IN THE
SUPERBLEND THEREAFTER. DID MAKE SOME MINOR...TERRAIN BASED...
ADJUSTMENTS TO HOURLY AND MINIMUM TEMPERATURES TONIGHT. AS FOR
POPS...ENDED UP CLOSE TO A COMBINATION OF THE WETTER MAV AND DRIER
MET TODAY WHILE AGREED WITH THE LOW POPS FROM ALL GUIDANCE TONIGHT
AND WEDNESDAY ACROSS EAST KENTUCKY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 419 AM EST TUE JAN 27 2015
THE PERIOD BEGINS WITH HIGH PRESSURE CENTERED TO THE NORTH AND EAST
WITH SOME WEAK UPPER LEVEL RIDGING ACROSS THE REGION. EYES TURN
QUICKLY TO APPROACHING SURFACE LOW ACROSS THE MIDWEST THAT IS
FORECAST TO PROGRESS EAST INTO THE GREAT LAKES. A COLD FRONT
EXTENDING SOUTH FROM THE LOW WILL BE THE DRIVER FOR CHANCES OF PRECIP
AS WE MOVE INTO THURSDAY MORNING INTO THURSDAY NIGHT. THEREFORE
WEDNESDAY NIGHT WILL BE MET WITH INCREASING CLOUDS AND CHANCES OF
PRECIP INCREASING AS WE MOVE TOWARD DAYLIGHT ON THURSDAY. THE PRECIP
WILL BRING A CHANCES OF SNOW OR RAIN/SNOW MIX THURSDAY MORNING BEFORE
CHANGING TO ALL RAIN LATE MORNING INTO THURSDAY AS WARMER AIR MAKES
ITS WAY INTO THE REGION. THIS IS ALSO EVIDENT IN THE SOUNDS AS DRYER
AIR IS SEEN IN THE UPPER LEVEL LEADING TO LESS ICE BY THURSDAY
AFTERNOON. OTHERWISE THIS LOW PRESSURE SYSTEM AND ASSOCIATED
SHORTWAVE WILL MOVE EAST THURSDAY NIGHT WITH LOW DEEPENING ACROSS THE
NORTHEAST US. HERE WE SWITCH TO WEST TO NORTHWEST FLOW AND THEREFORE
HAVE KEPT SOME POPS ACROSS EAST AND SOUTHEAST THURSDAY NIGHT INTO
EARLY FRIDAY. THIS WILL LIKELY MIX WITH OR CHANGE TO SNOW AS WE MOVE
THROUGH THE NIGHT. GIVEN LIMITED MOISTURE AT THIS POINT WOULD THINK
LITTLE TO ANY ACCUMULATIONS WOULD BE EXPECTED WITH BEST CHANCES
ACROSS THE HIGHER TERRAIN.
MOVING INTO FRIDAY EXPECT DECREASING CLOUDS AND HIGH PRESSURE TO DROP
SOUTH OUT OF THE UPPER PLAINS. THIS WILL USHER IN GENERALLY BELOW
NORMAL TEMPS FOR FRIDAY. THE QUESTION REMAINS FRIDAY NIGHT AS TO HOW
MUCH THE TEMPS BOTTOM OUT. RIGHT NOW WOULD SEEM LIKE BEST CHANCES FOR
DECOUPLING WOULD BE ACROSS THE NORTH AND FAR EASTERN PORTIONS OF THE
CWA. DID INTRODUCE SOME TEENS TO BETTER MATCH NEIGHBORING OFFICES.
AFTER THIS THE HIGH PRESSURE MOVES EAST WITH RETURN FLOW SATURDAY
WITH TEMPERATURES GENERALLY ABLE TO REBOUND INTO THE UPPER 30S TO
LOWER 40S.
THEN FOCUS SHIFTS TO NEXT SYSTEM DEVELOPING ACROSS THE SOUTHWEST US
AND PLAINS STATES. THIS LOW PRESSURE WILL EVENTUALLY GET PICK UP BY
NORTHERN STREAM SHORTWAVE AND PROGRESS EAST INTO THE MISSISSIPPI
RIVER VALLEY LATE SATURDAY NIGHT. WE DO INTRODUCE SLIGHT TO CHANCE
POPS SATURDAY NIGHT WITH SOME OF THIS MIXING WITH SNOW AND RAIN
BEFORE CHANGING TO ALL RAIN SUNDAY AS LOW PRESSURE DEEPENS ALONG AND
NEAR THE OHIO RIVER VALLEY THROUGH THE DAY SUNDAY. THIS RAIN WILL
ONCE AGAIN TRANSITION TO MIX AND SNOW SUNDAY EVENING AND SUNDAY
NIGHT FROM NORTH TO SOUTH AS COLDER AIR FILTERS INTO THE REGION
BEHIND THIS LOW. GIVEN THE MORE NORTHERN TRACK OF THIS SURFACE LOW
AND BEST QPF AHEAD OF COLDER AIR WOULD THINK THAT ACCUMULATIONS WOULD
BE LIGHT IN TERMS OF ANY SNOW WE ARE ABLE TO GET. KEEP IN MIND THIS
IS STILL IN THE FARTHER REACHES OF THE LONG TERM FORECAST AND WILL
HAVE TO BE FINE TUNED AS WE GET CLOSER TO THE EVENT. AFTER THIS
SYSTEM MOVES EAST WITH SOME NW FLOW SNOW SHOWERS CONTINUING ACROSS
THE EAST AND SOUTHEAST. OTHERWISE COLDER AIR CONTINUES TO FILTER INTO
THE REGION WITH TEMPERATURES STRUGGLING TO MAKE IT ABOVE FREEZING
MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 705 AM EST TUE JAN 27 2015
A STREAM OF SHORTWAVE ENERGY ALOFT WILL KEEP THE CHANCES OF SNOW IN
THE FORECAST THROUGH MID MORNING FOR MUCH OF EASTERN KENTUCKY. THE
EARLIER BANDS OF LIGHT SNOW SET UP MAINLY OVER THE SOUTHWEST PORTION
OF THE FORECAST AREA...BUT THE NEXT BATCH...AND LIKELY LAST ONE...
LOOKS TO PASS THROUGH THE AREA MORE TO THE NORTHEAST OF THE EARLIER
ONES WITH A BETTER CHANCE OF AFFECTING THE JKL/SYM/SJS TAF SITES.
HAVE UPDATED THESE WITH A TEMPO FOR SOME MVFR AND IFR CIGS AND MVFR
VIS WITH ANY SNOW SHOWERS THROUGH MID MORNING. THE REST OF THE AREA
WILL SEE THEIR CURRENT IFR CIGS IMPROVE TO MVFR SHORTLY AND THEN VFR
LIKELY BY 17Z. LOOKING AT THE TIME HEIGHT SERIES FOR TONIGHT DECIDED
TO ADD SOME IFR STRATUS IN THE EASTERN TAF SITES IN THE PREDAWN
HOURS. WINDS WILL GENERALLY BE LIGHT AND VARIABLE THROUGH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...GREIF
LONG TERM...DJ
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS JACKSON KY
419 AM EST TUE JAN 27 2015
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 335 AM EST TUE JAN 27 2015
07Z SFC ANALYSIS SHOWS A DEEP AREA OF LOW PRESSURE OFF TO THE
NORTHEAST WHILE LOCALLY THE PRESSURE GRADIENT IS RATHER RELAXED AND
THIS IS LIMITING THE UPSLOPE COMPONENT OF THIS NIGHT/S SNOW THREAT.
THE MAIN BANDS OF SNOW ARE BEING PRIMARILY DRIVEN BY A SFC TROUGH
AXIS SPLITTING THE STATE AND A STREAM OF MID LEVEL ENERGY RUNNING
NORTH NORTHWEST TO THE SOUTH SOUTHEAST OVER PARTS OF CENTRAL AND
EASTERN KENTUCKY. ON RADAR...THIS BAND LINES UP WELL WITH THIS
ENERGY STREAM AND IS ALSO ABLE TO TAP INTO EXTRA MOISTURE FROM LAKE
MICHIGAN. THE SNOW ASSOCIATED WITH THIS HAS BEEN RELATIVELY LIGHT
WITH MOST SITES REPORTING SNOW SEEING 4SM OR BETTER VIS...THOUGH IT
IS LIKELY THAT UNDER THE HIGHEST RADAR RETURNS VIS IS LESS THAN 2
MILES. FOR THESE LOCATIONS...A COUPLE OF TENTHS OF AN INCH OR SO OF
ACCUMULATION WILL BE POSSIBLE WHILE MOST OTHER PLACES WILL SEE JUST A
THICK DUSTING OR LESS. AN SPS IS IN EFFECT FOR THIS AND IT WILL BE
CONTINUED THROUGH DAWN AND THE MORNING RUSH HOUR FOR GOOD MEASURE.
TEMPERATURES...MEANWHILE ARE IN THE MID TO UPPER 20S ACROSS THE AREA
WITH DEWPOINTS A DEGREE OR SO LOWER AND WINDS LIGHT TO CALM.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION
OF THE FORECAST AS A CLOSED LOW DEEPENS OFF THE NEW ENGLAND COAST AND
A STREAM OF ENERGY FLOWS NNW TO SSE OVER KENTUCKY AND INTO THE
BROADER EAST COAST TROUGH TODAY. THIS FLOW WILL BE NUDGED EAST BY A
MODERATELY STRONG RIDGE IN THE SOUTHERN STREAM CROSSING THE SOUTHERN
PLAINS LATER TONIGHT. THIS RIDGE WILL BE PUSHED SOUTH BY A DEVELOPING
TROUGH COMING OUT OF THE CENTRAL ROCKIES AND MOVING INTO THE CENTRAL
PLAINS LATER WEDNESDAY. GIVEN THE GOOD MODEL AGREEMENT HAVE FAVORED
THE HIGHER RESOLUTION HRRR AND NAM12 THROUGH THE FIRST PART OF THE
FORECAST AND A BLEND THEREAFTER.
SENSIBLE WEATHER WILL FEATURE A BATCH OF EARLY MORNING SNOW SHOWERS
TARGETING MAINLY THE CUMBERLAND VALLEY OF EASTERN KENTUCKY. A FEW
FLURRIES WILL THEN LINGER INTO EARLY AFTERNOON FOR FAR SOUTHEAST
PARTS OF THE CWA BEFORE ALSO COMING TO AN END BY EARLY EVENING AS THE
CLOUDS ATTEMPT TO CLEAR. THIS...ALONG WITH SOME CONTINUED CAA FROM
THE EAST COAST STORM...WILL MAKE FOR A CHILLY NIGHT WITH LOWS IN THE
TEENS FOR WEDNESDAY MORNING. DESPITE HIGH PRESSURE PASSING THROUGH...
A BATCH OF LOW CLOUDS COULD DEVELOP OVERNIGHT AND HUG OUR EASTERN
ZONES INTO DAWN WEDNESDAY...WHICH MAY SPARE THESE AREAS THE COLDEST
TEMPS. THIS LOW LEVEL MOISTURE WILL ALSO NEED TO BE WATCHED FOR A
POTENTIAL OF SPOTTY FREEZING DRIZZLE IF THE STRATUS GETS THICK
ENOUGH. FOR NOW...THOUGH...IT LOOKS LIKE THIS WILL NOT BE THE
CASE...BUT THE POTENTIAL IS THERE. OTHERWISE...THE APPROACH OF
ANOTHER NORTHERN PASSING SFC LOW WILL HELP TO WARM THE AREA UP ON
WEDNESDAY WITH TEMPS REBOUNDING INTO THE MID 30S NORTHEAST TO THE
LOWER 40S SOUTHWEST. HOWEVER...HIGH CLOUDS WILL START TO MOVE IN BY
AFTERNOON FROM THE NORTHWEST LIMITING SUNSHINE ONCE ANY LOW CLOUDS
BREAK UP.
USED THE BCCONSSHORT AS A STARTING POINT FOR TEMPERATURES...
DEWPOINTS...AND WINDS THROUGH THIS AFTERNOON BEFORE PLUGGING IN THE
SUPERBLEND THEREAFTER. DID MAKE SOME MINOR...TERRAIN BASED...
ADJUSTMENTS TO HOURLY AND MINIMUM TEMPERATURES TONIGHT. AS FOR
POPS...ENDED UP CLOSE TO A COMBINATION OF THE WETTER MAV AND DRIER
MET TODAY WHILE AGREED WITH THE LOW POPS FROM ALL GUIDANCE TONIGHT
AND WEDNESDAY ACROSS EAST KENTUCKY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 419 AM EST TUE JAN 27 2015
THE PERIOD BEGINS WITH HIGH PRESSURE CENTERED TO THE NORTH AND EAST
WITH SOME WEAK UPPER LEVEL RIDGING ACROSS THE REGION. EYES TURN
QUICKLY TO APPROACHING SURFACE LOW ACROSS THE MIDWEST THAT IS
FORECAST TO PROGRESS EAST INTO THE GREAT LAKES. A COLD FRONT
EXTENDING SOUTH FROM THE LOW WILL BE THE DRIVER FOR CHANCES OF PRECIP
AS WE MOVE INTO THURSDAY MORNING INTO THURSDAY NIGHT. THEREFORE
WEDNESDAY NIGHT WILL BE MET WITH INCREASING CLOUDS AND CHANCES OF
PRECIP INCREASING AS WE MOVE TOWARD DAYLIGHT ON THURSDAY. THE PRECIP
WILL BRING A CHANCES OF SNOW OR RAIN/SNOW MIX THURSDAY MORNING BEFORE
CHANGING TO ALL RAIN LATE MORNING INTO THURSDAY AS WARMER AIR MAKES
ITS WAY INTO THE REGION. THIS IS ALSO EVIDENT IN THE SOUNDS AS DRYER
AIR IS SEEN IN THE UPPER LEVEL LEADING TO LESS ICE BY THURSDAY
AFTERNOON. OTHERWISE THIS LOW PRESSURE SYSTEM AND ASSOCIATED
SHORTWAVE WILL MOVE EAST THURSDAY NIGHT WITH LOW DEEPENING ACROSS THE
NORTHEAST US. HERE WE SWITCH TO WEST TO NORTHWEST FLOW AND THEREFORE
HAVE KEPT SOME POPS ACROSS EAST AND SOUTHEAST THURSDAY NIGHT INTO
EARLY FRIDAY. THIS WILL LIKELY MIX WITH OR CHANGE TO SNOW AS WE MOVE
THROUGH THE NIGHT. GIVEN LIMITED MOISTURE AT THIS POINT WOULD THINK
LITTLE TO ANY ACCUMULATIONS WOULD BE EXPECTED WITH BEST CHANCES
ACROSS THE HIGHER TERRAIN.
MOVING INTO FRIDAY EXPECT DECREASING CLOUDS AND HIGH PRESSURE TO DROP
SOUTH OUT OF THE UPPER PLAINS. THIS WILL USHER IN GENERALLY BELOW
NORMAL TEMPS FOR FRIDAY. THE QUESTION REMAINS FRIDAY NIGHT AS TO HOW
MUCH THE TEMPS BOTTOM OUT. RIGHT NOW WOULD SEEM LIKE BEST CHANCES FOR
DECOUPLING WOULD BE ACROSS THE NORTH AND FAR EASTERN PORTIONS OF THE
CWA. DID INTRODUCE SOME TEENS TO BETTER MATCH NEIGHBORING OFFICES.
AFTER THIS THE HIGH PRESSURE MOVES EAST WITH RETURN FLOW SATURDAY
WITH TEMPERATURES GENERALLY ABLE TO REBOUND INTO THE UPPER 30S TO
LOWER 40S.
THEN FOCUS SHIFTS TO NEXT SYSTEM DEVELOPING ACROSS THE SOUTHWEST US
AND PLAINS STATES. THIS LOW PRESSURE WILL EVENTUALLY GET PICK UP BY
NORTHERN STREAM SHORTWAVE AND PROGRESS EAST INTO THE MISSISSIPPI
RIVER VALLEY LATE SATURDAY NIGHT. WE DO INTRODUCE SLIGHT TO CHANCE
POPS SATURDAY NIGHT WITH SOME OF THIS MIXING WITH SNOW AND RAIN
BEFORE CHANGING TO ALL RAIN SUNDAY AS LOW PRESSURE DEEPENS ALONG AND
NEAR THE OHIO RIVER VALLEY THROUGH THE DAY SUNDAY. THIS RAIN WILL
ONCE AGAIN TRANSITION TO MIX AND SNOW SUNDAY EVENING AND SUNDAY
NIGHT FROM NORTH TO SOUTH AS COLDER AIR FILTERS INTO THE REGION
BEHIND THIS LOW. GIVEN THE MORE NORTHERN TRACK OF THIS SURFACE LOW
AND BEST QPF AHEAD OF COLDER AIR WOULD THINK THAT ACCUMULATIONS WOULD
BE LIGHT IN TERMS OF ANY SNOW WE ARE ABLE TO GET. KEEP IN MIND THIS
IS STILL IN THE FARTHER REACHES OF THE LONG TERM FORECAST AND WILL
HAVE TO BE FINE TUNED AS WE GET CLOSER TO THE EVENT. AFTER THIS
SYSTEM MOVES EAST WITH SOME NW FLOW SNOW SHOWERS CONTINUING ACROSS
THE EAST AND SOUTHEAST. OTHERWISE COLDER AIR CONTINUES TO FILTER INTO
THE REGION WITH TEMPERATURES STRUGGLING TO MAKE IT ABOVE FREEZING
MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1245 AM EST TUE JAN 27 2015
A STREAM OF SHORTWAVE ENERGY ALOFT WILL KEEP THE CHANCES OF SNOW IN
THE FORECAST THROUGH MID MORNING TUESDAY FOR EASTERN KENTUCKY. THE
EARLIER BAND OF LIGHT SNOW SET UP MAINLY OVER THE SOUTHWEST PORTION
OF EAST KENTUCKY...BUT THE NEXT BATCH LOOKS TO PASS THROUGH THE AREA
MORE TO THE NORTHEAST OF THE FIRST WITH A BETTER CHANCE OF AFFECTING
THE LOZ AND JKL TAF SITES. HAVE UPDATED THESE TWO WITH SOME MVFR CIGS
AND VIS EXPECTED FOR THE REST OF THE NIGHT IN OFF AND ON SNOW
SHOWERS. THE REST OF THE AREA WILL LIKELY REMAIN WITH MVFR OR NEAR
MVFR CIGS ALONG WITH OCCASIONAL FLURRIES AND AN ODD SNOW SHOWER OR
TWO. HAVE KEPT THE SYM AND SJS WITH JUST A VCSH MENTION DUE TO ALL
GUIDANCE AND TRENDS KEEPING THE BETTER SNOW TO THE SOUTHWEST THROUGH
DAWN. THE LOWER CLOUDS WILL BREAK UP IN MOST PLACES BY MID MORNING
WITH IMPROVING VFR CONDITIONS ANTICIPATED FOR THE AFTERNOON
SPREADING FROM WEST TO EAST ACROSS THE FORECAST AREA. WINDS WILL
GENERALLY BE LIGHT AND VARIABLE THROUGH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...DJ
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
335 AM EST TUE JAN 27 2015
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 335 AM EST TUE JAN 27 2015
07Z SFC ANALYSIS SHOWS A DEEP AREA OF LOW PRESSURE OFF TO THE
NORTHEAST WHILE LOCALLY THE PRESSURE GRADIENT IS RATHER RELAXED AND
THIS IS LIMITING THE UPSLOPE COMPONENT OF THIS NIGHT/S SNOW THREAT.
THE MAIN BANDS OF SNOW ARE BEING PRIMARILY DRIVEN BY A SFC TROUGH
AXIS SPLITTING THE STATE AND A STREAM OF MID LEVEL ENERGY RUNNING
NORTH NORTHWEST TO THE SOUTH SOUTHEAST OVER PARTS OF CENTRAL AND
EASTERN KENTUCKY. ON RADAR...THIS BAND LINES UP WELL WITH THIS
ENERGY STREAM AND IS ALSO ABLE TO TAP INTO EXTRA MOISTURE FROM LAKE
MICHIGAN. THE SNOW ASSOCIATED WITH THIS HAS BEEN RELATIVELY LIGHT
WITH MOST SITES REPORTING SNOW SEEING 4SM OR BETTER VIS...THOUGH IT
IS LIKELY THAT UNDER THE HIGHEST RADAR RETURNS VIS IS LESS THAN 2
MILES. FOR THESE LOCATIONS...A COUPLE OF TENTHS OF AN INCH OR SO OF
ACCUMULATION WILL BE POSSIBLE WHILE MOST OTHER PLACES WILL SEE JUST A
THICK DUSTING OR LESS. AN SPS IS IN EFFECT FOR THIS AND IT WILL BE
CONTINUED THROUGH DAWN AND THE MORNING RUSH HOUR FOR GOOD MEASURE.
TEMPERATURES...MEANWHILE ARE IN THE MID TO UPPER 20S ACROSS THE AREA
WITH DEWPOINTS A DEGREE OR SO LOWER AND WINDS LIGHT TO CALM.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION
OF THE FORECAST AS A CLOSED LOW DEEPENS OFF THE NEW ENGLAND COAST AND
A STREAM OF ENERGY FLOWS NNW TO SSE OVER KENTUCKY AND INTO THE
BROADER EAST COAST TROUGH TODAY. THIS FLOW WILL BE NUDGED EAST BY A
MODERATELY STRONG RIDGE IN THE SOUTHERN STREAM CROSSING THE SOUTHERN
PLAINS LATER TONIGHT. THIS RIDGE WILL BE PUSHED SOUTH BY A DEVELOPING
TROUGH COMING OUT OF THE CENTRAL ROCKIES AND MOVING INTO THE CENTRAL
PLAINS LATER WEDNESDAY. GIVEN THE GOOD MODEL AGREEMENT HAVE FAVORED
THE HIGHER RESOLUTION HRRR AND NAM12 THROUGH THE FIRST PART OF THE
FORECAST AND A BLEND THEREAFTER.
SENSIBLE WEATHER WILL FEATURE A BATCH OF EARLY MORNING SNOW SHOWERS
TARGETING MAINLY THE CUMBERLAND VALLEY OF EASTERN KENTUCKY. A FEW
FLURRIES WILL THEN LINGER INTO EARLY AFTERNOON FOR FAR SOUTHEAST
PARTS OF THE CWA BEFORE ALSO COMING TO AN END BY EARLY EVENING AS THE
CLOUDS ATTEMPT TO CLEAR. THIS...ALONG WITH SOME CONTINUED CAA FROM
THE EAST COAST STORM...WILL MAKE FOR A CHILLY NIGHT WITH LOWS IN THE
TEENS FOR WEDNESDAY MORNING. DESPITE HIGH PRESSURE PASSING THROUGH...
A BATCH OF LOW CLOUDS COULD DEVELOP OVERNIGHT AND HUG OUR EASTERN
ZONES INTO DAWN WEDNESDAY...WHICH MAY SPARE THESE AREAS THE COLDEST
TEMPS. THIS LOW LEVEL MOISTURE WILL ALSO NEED TO BE WATCHED FOR A
POTENTIAL OF SPOTTY FREEZING DRIZZLE IF THE STRATUS GETS THICK
ENOUGH. FOR NOW...THOUGH...IT LOOKS LIKE THIS WILL NOT BE THE
CASE...BUT THE POTENTIAL IS THERE. OTHERWISE...THE APPROACH OF
ANOTHER NORTHERN PASSING SFC LOW WILL HELP TO WARM THE AREA UP ON
WEDNESDAY WITH TEMPS REBOUNDING INTO THE MID 30S NORTHEAST TO THE
LOWER 40S SOUTHWEST. HOWEVER...HIGH CLOUDS WILL START TO MOVE IN BY
AFTERNOON FROM THE NORTHWEST LIMITING SUNSHINE ONCE ANY LOW CLOUDS
BREAK UP.
USED THE BCCONSSHORT AS A STARTING POINT FOR TEMPERATURES...
DEWPOINTS...AND WINDS THROUGH THIS AFTERNOON BEFORE PLUGGING IN THE
SUPERBLEND THEREAFTER. DID MAKE SOME MINOR...TERRAIN BASED...
ADJUSTMENTS TO HOURLY AND MINIMUM TEMPERATURES TONIGHT. AS FOR
POPS...ENDED UP CLOSE TO A COMBINATION OF THE WETTER MAV AND DRIER
MET TODAY WHILE AGREED WITH THE LOW POPS FROM ALL GUIDANCE TONIGHT
AND WEDNESDAY ACROSS EAST KENTUCKY.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 356 PM EST MON JAN 26 2015
THE EXTENDED PERIOD BEGINS WITH A TROUGH EXITING TO OUR EAST AS SHORTWAVE
RIDGING BUILDS INTO EASTERN KENTUCKY. THIS RIDGING SHOULD PROVIDE A
TEMPORARY RELIEF OF PRECIP WEDNESDAY AFTERNOON INTO THURSDAY
MORNING. BY 12Z THURSDAY... BOTH GFS/ECMWF SHOW A LOW PRESSURE
SYSTEM CLIPPING NORTHERN KENTUCKY AND LIFTING NEWD FROM THE OHIO
VALLEY TOWARDS NEW ENGLAND... WITH THE GFS PROVIDING MORE SUPPORT
FOR THE MORE ROBUST ECMWF SOLUTION. ANOTHER LULL IN PRECIP FOLLOWS
UNTIL SUNDAY MORNING. AT THAT POINT... MODELS DEPICT A LARGE CLOSED
LOW IN THE SOUTHERN STREAM...OPENING UP AND SPILLING ITS ENERGY EAST
INTO THE FLOW RIDGING OVER THE TENNESSEE VALLEY. THE MODELS CONTINUE
TO SHOW SOME CONNECTION TO THE NORTHERN AND SOUTHERN STREAMS WHICH
WOULD CERTAINLY MAKE THINGS MORE INTERESTING FOR THE UPCOMING
WEEKEND IF THAT PANS OUT. FOR NOW... WILL SHOW ONLY LIMITED
INTERACTION AND EASE INTO A MORE DYNAMIC SCENARIO GIVEN THE
UNCERTAINTY AND LACK OF MODEL RUN TO RUN CONSISTENCY WITH THIS PART
OF THE FORECAST.
SENSIBLE WEATHER WILL FEATURE THE ENDING OF THE UPSLOPE SNOW
SHOWERS/FLURRIES IN THE FAR EAST EARLY WEDNESDAY MORNING WITH SOME
SUNSHINE RETURNING. THE NEXT CLIPPER SYSTEM WILL THEN MOVE INTO THE
OHIO VALLEY ON THURSDAY WITH A CHANCE FOR RAIN AND SNOW ACROSS THE
AREA FRIDAY MORNING. ONLY A BRIEF WINDOW FOR DRYING CAN BE EXPECTED
FROM FRIDAY NIGHT INTO SATURDAY NIGHT BEFORE THE POTENTIAL FOR
MAINLY SNOW ARRIVES FROM THE SOUTHWEST IN FAST LOW AND MID LEVEL
FLOW RIDING ALONG A WEST TO EAST ARCTIC BOUNDARY LYING OVER THE OHIO
VALLEY. THIS BOUNDARY IS EXPECTED TO PUSH ON THROUGH KENTUCKY BY
MONDAY MORNING WITH SNOW CHANCES CONTINUING...MAINLY IN THE
SOUTHERN PARTS OF THE CWA. THIS SYSTEM WILL HAVE TO BE CLOSELY
MONITORED AS MODELS COME INTO BETTER AGREEMENT WITH THE PHASING OF
THE NORTHERN AND SOUTHERN STREAM ENERGY AS WELL AS HOW QUICKLY THE
COLD AIR SETTLES INTO THE REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1245 AM EST TUE JAN 27 2015
A STREAM OF SHORTWAVE ENERGY ALOFT WILL KEEP THE CHANCES OF SNOW IN
THE FORECAST THROUGH MID MORNING TUESDAY FOR EASTERN KENTUCKY. THE
EARLIER BAND OF LIGHT SNOW SET UP MAINLY OVER THE SOUTHWEST PORTION
OF EAST KENTUCKY...BUT THE NEXT BATCH LOOKS TO PASS THROUGH THE AREA
MORE TO THE NORTHEAST OF THE FIRST WITH A BETTER CHANCE OF AFFECTING
THE LOZ AND JKL TAF SITES. HAVE UPDATED THESE TWO WITH SOME MVFR CIGS
AND VIS EXPECTED FOR THE REST OF THE NIGHT IN OFF AND ON SNOW
SHOWERS. THE REST OF THE AREA WILL LIKELY REMAIN WITH MVFR OR NEAR
MVFR CIGS ALONG WITH OCCASIONAL FLURRIES AND AN ODD SNOW SHOWER OR
TWO. HAVE KEPT THE SYM AND SJS WITH JUST A VCSH MENTION DUE TO ALL
GUIDANCE AND TRENDS KEEPING THE BETTER SNOW TO THE SOUTHWEST THROUGH
DAWN. THE LOWER CLOUDS WILL BREAK UP IN MOST PLACES BY MID MORNING
WITH IMPROVING VFR CONDITIONS ANTICIPATED FOR THE AFTERNOON
SPREADING FROM WEST TO EAST ACROSS THE FORECAST AREA. WINDS WILL
GENERALLY BE LIGHT AND VARIABLE THROUGH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...JVM
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
100 AM EST TUE JAN 27 2015
.UPDATE...
ISSUED AT 100 AM EST TUE JAN 27 2015
PER RADAR TRENDS AND THE LATEST HRRR/SREF GUIDANCE...THE LIGHT SNOW
BANDS THAT AFFECTED THE FAR SOUTHWEST PORTION OF THE CWA EARLIER IN
THE EVENING WILL SHIFT A BIT MORE TO THE NORTHEAST EARLY THIS
MORNING THESE WILL LIKELY AFFECT MORE OF THE BREADTH OF EASTERN
KENTUCKY AND CONTINUE THROUGH THE EARLY MORNING HOURS...BUT LIKELY NOT
LEAVE MUCH MORE THAN A DUSTING BEHIND IN ANY ONE LOCATION. HOWEVER...
ALREADY COLD ROADS COULD LEAD TO ADDITIONAL SLICK SPOTS INTO DAWN
TUESDAY. HAVE UPDATED THE FORECAST TO FINE TUNE POPS/WX AND SNOW
AMOUNTS THROUGH THE MORNING. ALSO TWEAKED THE T AND TD GRIDS BASED
ON THE LATEST OBS/TRENDS/BCCONSSHORT GUIDANCE THROUGH DAWN. THESE
UPDATED GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 1100 PM EST MON JAN 26 2015
NO CRUCIAL CHANGES SINCE THE PREVIOUS UPDATE. NEAR TERM TEMPERATURES
CONTINUE TO BE WELL ON TRACK...FRESHENED THEM UP WITH THE LATEST
OBSERVATIONAL DATA...AS WELL AS THE DEW POINTS AND WINDS. FOCUS
CONTINUES TO BE THE SNOW POTENTIAL AS WE HEAD INTO THE OVERNIGHT
HOURS. HRRR HAD A GOOD HANDLE ON THE SNOW EARLIER THIS
EVENING...SHOWING AN EVENTUAL LESSENING AS WE HEADED INTO THE
CURRENT PERIOD. WHILE A FEW LIGHT SNOW SHOWERS AND/OR FLURRIES ARE
LIKELY ONGOING IN PORTIONS OF THE SW CWA...THERE IS A NOTICEABLE
BREAK IN THE WIDESPREAD PRECIP WE HAD OVER CENTRAL KY EARLIER. THAT
BEING SAID...ANOTHER BAND OF ENHANCED PRECIP IS CURRENTLY MAKING ITS
WAY FROM SOUTHERN LAKE MICHIGAN AND SOUTHWARD ACROSS INDIANA. THIS
WILL LIKELY MAKE IT INTO THE CWA OVER THE NEXT FEW HOURS.
UNFORTUNATELY...THE LATEST HRRR HAS A NOTICEABLE LACK IN
INITIALIZATION...AND FURTHERMORE IT IS SHOWING UNLIKELY ARTIFACTS AS
THIS NEXT ROUND OF PRECIP MOVES IN. NOT PUTTING MUCH FAITH INTO THE
HRRR AT THIS POINT FOR THE INCOMING PRECIP. THE LATEST NAM12 AND
ECMWF ALSO PICK UP ON THIS SECOND BAND...THOUGH THE ECMWF LIKELY HAS
THE BETTER HANDLE ON QPF TOTALS. THIS WILL BE THE THING TO MONITOR
FOR POTENTIAL UPDATES THROUGH THE NEXT FEW HOURS.
UPDATE ISSUED AT 658 PM EST MON JAN 26 2015
A BAND OF RADAR REFLECTIVITIES IS CURRENTLY MAKING ITS WAY INTO THE
SW PORTION OF THE CWA. HIGHER REFLECTIVITIES...WHICH HAVE BEEN
REPORTED TO BE PUTTING DOWN SOME QUICK SNOW IS CURRENTLY OVER CENTRAL
KY AND MAKING ITS WAY EASTWARD. WHILE MOST OF THE REFLECTIVITIES OVER
OUR CWA CURRENTLY ARE ONLY PRODUCING FLURRIES...GIVEN THE UPSTREAM
REPORTS...DID GO AHEAD AND INCREASE POPS OVER OUR SW
COUNTIES...BRINGING IN SNOW POTENTIAL A COUPLE HOURS SOONER THAN WAS
PREVIOUSLY FORECAST. ALSO ENDED UP BUMPING UP THE QPF BY A COUPLE
HUNDREDTHS IN THE SW BASED ON THE UPSTREAM REPORTS...BRINGING SNOW
TOTALS UP TO ABOUT HALF AN INCH OVERNIGHT FOR PULASKI...WAYNE...AND
MCCREARY COUNTIES. NEAR TERM TEMPERATURES SEEM TO BE IN FAIRLY GOOD
SHAPE BASED ON THE LATEST INGEST OF OBSERVATIONAL DATA.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 410 PM EST MON JAN 26 2015
AS OF MID TO LATE AFTERNOON...A SHORTWAVE TROUGH IS MOVING EAST OF
THE REGION INTO THE DEVELOPING DEEP TROUGH ACROSS THE EASTERN CONUS.
MEANWHILE THE CLIPPER SYSTEM THAT MOVED ACROSS THE AREA LAST NIGHT
INTO THIS MORNING IS BEGINNING TO REORGANIZE INTO A DEEP
NOR`EASTER/BLIZZARD EAST OF THE MID ATLANTIC STATES. THE REGION WILL
REMAIN UNDER THE INFLUENCE OF NW ALOFT BETWEEN THE DEEPENING TROUGH
ALONG THE EASTERN SEABOARD AND RIDGING EXTENDING FROM MEXICO INTO THE
ROCKIES. AT THE SFC...HIGH PRESSURE WILL ALSO GRADUALLY BUILD INTO THE
GREAT LAKES AND LOWER OH VALLEY REGION ONCE THE CLIPPER SFC LOW
APPROACHING FROM THE OH VALLEY DEPARTS ON TUESDAY.
THE SHORTWAVE TROUGH MOVING INTO WV WILL TAKE THE STEADIER SNOW WITH
IT. LOW LEVEL MOISTURE WILL REMAINS ACROSS THE AREA WITH UPSLOPE
FLOW AND SATURATION IN THE LOW CLOUDS TO COLDER THAN -8C...USUALLY
ENOUGH FOR SMALL SNOWFLAKES OF LIGHT SNOW AND FLURRIES. THE CLIPPER
SYSTEM WILL TRACK TO OUR SW FROM WESTERN KY TO THE SOUTHERN
APPALACHIANS. THIS TRACK WILL FAVOR LOCATIONS ACROSS THE SW PART OF
THE AREA FOR LIGHT SNOW OR SCATTERED SNOW SHOWER CHANCES...ALTHOUGH
MODEL TIME HEIGHT SECTIONS FORM THE NAM AND GFS MODELS DO HAVE A
WINDOW OF RATHER DEEP MOISTURE AND RATHER WEAK OMEGA NEAR 12Z...OR 7
AM ON TUESDAY. SNOW SHOWER CHANCES WILL REMAIN NEAR THE VA BORDER ON
THE UPSLOPE FLOW INTO THIS EVENING...WITH CHANCES FOR SNOW INCREASING
ACROSS THE SOUTHWEST PART OF THE AREA THROUGH THE EVENING AND INTO
THE OVERNIGHT HOURS. DAYTIME HEATING AND COLD TEMPERATURES ALOFT WILL
LEAD TO A CONTINUED CHANCE FOR SNOW SHOWERS AND FLURRIES ON TUESDAY
AND UNTIL THE FLOW BECOMES MORE NORTHERLY LATE TUE INTO TUESDAY
EVENING. QPF WITH THIS WILL BE LIGHT WITH ANY ACCUMULATIONS OF
A HALF AN INCH OR LESS ON AVERAGE WHERE SNOW DOES OCCUR. AN SPS WAS
REISSUED TO HIGHLIGHT THE LIGHT SNOW ACCUMULATION POTENTIAL AND
REFREEZE POTENTIAL THIS EVENING AND TONIGHT.
LOWS TONIGHT WILL BE COLDEST IN THE NORTH AND EAST WHERE 850 MB TEMPS
ARE PROGGED TO BE COLDEST. WE HAVE UNDERCUT MOST GUIDANCE TEMPS ON
AVERAGE ON TUESDAY AS THERE WILL BE SNOW ON THE GROUND IN SOME AREAS
AND MODELS WERE GENERALLY TOO WARM WITH TEMPS TODAY. GRADUAL CLEARING
SHOULD OCCUR FROM LATE TUE INTO TUE NIGHT AND WITH A DRY AIRMASS
PROGGED AND SNOW COVER LIKELY REMAINING IN SOME AREAS...VALLEYS
SHOULD FALL WELL INTO THE TEENS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 356 PM EST MON JAN 26 2015
THE EXTENDED PERIOD BEGINS WITH A TROUGH EXITING TO OUR EAST AS SHORTWAVE
RIDGING BUILDS INTO EASTERN KENTUCKY. THIS RIDGING SHOULD PROVIDE A
TEMPORARY RELIEF OF PRECIP WEDNESDAY AFTERNOON INTO THURSDAY
MORNING. BY 12Z THURSDAY... BOTH GFS/ECMWF SHOW A LOW PRESSURE
SYSTEM CLIPPING NORTHERN KENTUCKY AND LIFTING NEWD FROM THE OHIO
VALLEY TOWARDS NEW ENGLAND... WITH THE GFS PROVIDING MORE SUPPORT
FOR THE MORE ROBUST ECMWF SOLUTION. ANOTHER LULL IN PRECIP FOLLOWS
UNTIL SUNDAY MORNING. AT THAT POINT... MODELS DEPICT A LARGE CLOSED
LOW IN THE SOUTHERN STREAM...OPENING UP AND SPILLING ITS ENERGY EAST
INTO THE FLOW RIDGING OVER THE TENNESSEE VALLEY. THE MODELS CONTINUE
TO SHOW SOME CONNECTION TO THE NORTHERN AND SOUTHERN STREAMS WHICH
WOULD CERTAINLY MAKE THINGS MORE INTERESTING FOR THE UPCOMING
WEEKEND IF THAT PANS OUT. FOR NOW... WILL SHOW ONLY LIMITED
INTERACTION AND EASE INTO A MORE DYNAMIC SCENARIO GIVEN THE
UNCERTAINTY AND LACK OF MODEL RUN TO RUN CONSISTENCY WITH THIS PART
OF THE FORECAST.
SENSIBLE WEATHER WILL FEATURE THE ENDING OF THE UPSLOPE SNOW
SHOWERS/FLURRIES IN THE FAR EAST EARLY WEDNESDAY MORNING WITH SOME
SUNSHINE RETURNING. THE NEXT CLIPPER SYSTEM WILL THEN MOVE INTO THE
OHIO VALLEY ON THURSDAY WITH A CHANCE FOR RAIN AND SNOW ACROSS THE
AREA FRIDAY MORNING. ONLY A BRIEF WINDOW FOR DRYING CAN BE EXPECTED
FROM FRIDAY NIGHT INTO SATURDAY NIGHT BEFORE THE POTENTIAL FOR
MAINLY SNOW ARRIVES FROM THE SOUTHWEST IN FAST LOW AND MID LEVEL
FLOW RIDING ALONG A WEST TO EAST ARCTIC BOUNDARY LYING OVER THE OHIO
VALLEY. THIS BOUNDARY IS EXPECTED TO PUSH ON THROUGH KENTUCKY BY
MONDAY MORNING WITH SNOW CHANCES CONTINUING...MAINLY IN THE
SOUTHERN PARTS OF THE CWA. THIS SYSTEM WILL HAVE TO BE CLOSELY
MONITORED AS MODELS COME INTO BETTER AGREEMENT WITH THE PHASING OF
THE NORTHERN AND SOUTHERN STREAM ENERGY AS WELL AS HOW QUICKLY THE
COLD AIR SETTLES INTO THE REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1245 AM EST TUE JAN 27 2015
A STREAM OF SHORTWAVE ENERGY ALOFT WILL KEEP THE CHANCES OF SNOW IN
THE FORECAST THROUGH MID MORNING TUESDAY FOR EASTERN KENTUCKY. THE
EARLIER BAND OF LIGHT SNOW SET UP MAINLY OVER THE SOUTHWEST PORTION
OF EAST KENTUCKY...BUT THE NEXT BATCH LOOKS TO PASS THROUGH THE AREA
MORE TO THE NORTHEAST OF THE FIRST WITH A BETTER CHANCE OF AFFECTING
THE LOZ AND JKL TAF SITES. HAVE UPDATED THESE TWO WITH SOME MVFR CIGS
AND VIS EXPECTED FOR THE REST OF THE NIGHT IN OFF AND ON SNOW
SHOWERS. THE REST OF THE AREA WILL LIKELY REMAIN WITH MVFR OR NEAR
MVFR CIGS ALONG WITH OCCASIONAL FLURRIES AND AN ODD SNOW SHOWER OR
TWO. HAVE KEPT THE SYM AND SJS WITH JUST A VCSH MENTION DUE TO ALL
GUIDANCE AND TRENDS KEEPING THE BETTER SNOW TO THE SOUTHWEST THROUGH
DAWN. THE LOWER CLOUDS WILL BREAK UP IN MOST PLACES BY MID MORNING
WITH IMPROVING VFR CONDITIONS ANTICIPATED FOR THE AFTERNOON
SPREADING FROM WEST TO EAST ACROSS THE FORECAST AREA. WINDS WILL
GENERALLY BE LIGHT AND VARIABLE THROUGH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...JP
LONG TERM...JVM
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
950 PM CST WED JAN 28 2015
.DISCUSSION...
A QUIET NIGHT UNDERWAY WITH HIGH PRES EAST OF THE
REGION...ALLOWING SELY WINDS TO BRING INCREASING LOW LVL MOISTURE
OVER THE AREA. DEWPOINTS ACRS SW LA AND SE TX ARE IN THE LOWER
50S WITH MIDDLE AND UPPER 40S ACRS ERN PORTIONS OF THE AREA.
OVERNIGHT LOWS ARE EXPECTED TO RUN ABOUT 5-10 DEGREES WARMER THAN
LAST NIGHT WITH LOWS IN THE LOWER TO MIDDLE 50S ACRS ALL BUT THE
ERN-MOST ZONES WHERE TEMPERATURES WILL BE IN THE UPPER 40S/NR 50.
WITH LT WINDS ACRS THE AREA AND DEWPOINT DEPRESSIONS
NARROWING...FOG SHOULD BEGIN DEVELOPING BY MIDNIGHT. FOG IS
EXPECTED TO BEGIN DEVELOPING ACRS LOWER SE TX/SW LA INITIALLY...THEN
INCREASE IN COVERAGE FURTHER NORTH AND EAST ACRS THE AREA THROUGH
THE NIGHT. SREF PROBABILITIES AS WELL AS NAM AND HRRR GUIDANCE
INDICATE THE POTENTIAL FOR VISIBILITIES LESS THAN ONE MILE...AND
DENSE FOG COULD BE POSSIBLE IN A FEW LOCATIONS. WILL CONTINUE TO
MONITOR TRENDS FOR THE POSSIBILITY OF A DENSE FOG ADVISORY.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 52 72 45 58 / 0 0 10 10
KBPT 55 72 47 59 / 0 10 10 10
KAEX 51 72 43 56 / 0 0 10 0
KLFT 50 74 46 58 / 0 0 10 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
PUBLIC/MARINE...24
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
200 PM EST TUE JAN 27 2015
.SYNOPSIS...
A COASTAL LOW PRESSURE SYSTEM WILL RAPIDLY INTENSIFY AS IT TRACKS
NORTH NORTHEAST OFF THE NEW ENGLAND COAST THROUGH TONIGHT.
MEANWHILE...HIGH PRESSURE SLOWLY BUILDS OVER THE MID ATLANTIC
THROUGH MIDWEEK. A COLD FRONT WILL CROSS THE AREA THURSDAY
NIGHT...FOLLOWED BY HIGH PRESSURE THROUGH SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WINTER WX ADVSRYS HAVE BEEN SCALED BACK THIS MORNG AS THE SNOW HAS
ENDED IN SOME AREAS. THIS TREND WILL CONTINUE THRU THE LATE MORNG
HRS. ALSO ADDED AN SPS FOR AREAS S OF THE ADVSRY AREA WHERE UP TO
ONE INCH OF ACCUMULATION IS PSBL...BUT MAINLY ON GRASSY SFCS.
PREVIOUS DISCUSSION...
QUICK UPDATE TO CLEAR MARYLAND EASTERN SHORE COUNTIES FROM WITNER
WX ADVISORY BASED ON RADAR TRENDS. GIVEN LATEST REPORTS AND
TRAFFIC CAMS IN METRO RIC/ORF AREAS, WILL CONTINUE THEM ELSWEHERE.
EARLY MORNING RADAR MOSAIC SHOWING NARROW BAND OF PCPN DROPPING
SOUTH FROM CENTRAL PA SOUTH INTO EASTERN/CENTRAL VA. VSBY AVGG
2-4SM IN SN, AND WE`VE RECEIVED QUITE A FEW REPORTS ~1 AND A FEW
IN THE 1 1/2 TO 2" ALONG THE NORTHERN NECK INTO THE PENINSULA.
TRAFFIC CAMS SHOWING AT LEAST A COATING INTO THE TIDEWATER AREA
(CONFIRMED BY LOCAL COOPERATIVE OBSERVER). WE WILL BE MAINTAINING
WINTER HEADLINES FOR A LITTLE LONGER, WITH THIS BAND OF SNSH WELL
HANDLED BY THE HRRR EARLY THIS MORNING. NOT EXPECTING ANY LOCALES
IN NORFOLK OR RICHMOND METRO AREAS WILL RECEIVE ANY MORE THAN AN
INCH...BUT WITH THE HEADLINE ALREADY IN PLACE AND THE POTENTIAL
FOR SNOW TO CAUSE SOME IMPACTS DURING THE MORNING COMMUTE...DON`T
FEEL DROPPING THE HEADLINES IS PRUDENT ATTM. WL REVISIT HEADLINES
AT 7AM UPDATE. DO EXPECT DAY CREW WILL BE ABLE TO CLEAR HEADLINES
SHORTLY AFTER 14Z IF NOT SOONER.
HAVE BUMPED POPS UP IN TO CATEGORICAL RANGE FOR COASTAL NE NC, AND
GRADUALLY TAPERED THEM OFF ALONG THE EASTERN SHORE BY MID-LATE
MORNING. DROPPED POPS INTO NO HIGHER THAN 20% BUT HAVE KEPT
FLURRIES IN THE FORECAST FOR FAR WESTERN ZONES, AS ACCUMS NOT
ANTICIPATED.
INTENSIFYING SFC LOW WILL CONTINUE TO LIFT NE INTO NEW ENGLAND
THROUGH TONIGHT. ALL POPS DROP OFF BY EARLY AFTN, WITH STRONG CAA
BRINGING BREEZY/WINDY CONDITIONS (25-30MPH GUSTS ALONG THE
COAST/ERN SHORE), AND HOLDING HIGHS IN THE MID TO UPPER 30S (~40
IN THE PIEDMONT) UNDER A CLOUDY TO MOSTLY CLOUDY SKY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
IMPROVING WX FOR THE SHORT TERM PERIOD. FOR TUE
NIGHT/WED...AFOREMENTIONED COASTAL LOW PULLS TOWARDS ATLANTIC
CANADA AS COLD SFC HIGH PRESSURE BUILDS IN FROM THE W. CLEARING
SKY AND GRADUALLY DIMINISHING NW WINDS WILL ALLOW EARLY MORNING
LOW TEMPS TO FALL INTO THE THE 20S FOR MOST, W/ WIND CHILLS IN THE
TEENS IN MOST LOCATIONS.
HIGH PRESSURE BUILDS OVER THE LOCAL AREA ON WEDNESDAY.
TEMPERATURES REMAIN COOL WITH SHALLOW MIXING AND A NNE WIND. HIGHS
ONLY RANGING FROM THE MID 30S OVER THE LWR ERN SHORE TO THE UPR
30S TO LWR 40S ELSEWHERE. DRY AGAIN FOR WED NIGHT WITH LOWS IN THE
20S TO NEAR 30 ALONG THE COAST.
RAIN CHCS INCREASE ACROSS THE AREA LATER THU/THU NGT AS NORTHERN
STREAM SHORTWAVE TROUGH TRACKS FROM THE UPPER MIDWEST ACROSS TO
THE GREAT LAKES, WITH THE ASSOCIATED SFC LOW PUSHING ACROSS THE
NORTHERN MID-ATLANTIC INTO NEW ENGLAND BY LATE THU NGT. DAY BEGINS
PARTLY CLOUDY WITH GRADUALLY INCREASING CLOUDS. BEST FORCING
REMAINS OFF TO THE NORTH, SO HAVE CAPPED POP AT NO HIGHER THAN 30%
FOR NOW. RAIN CHANCES DIMINISH THU NGT AS SFC COLD FRONT PUSHES
ACROSS THE AREA. FOR HIGHS, SW FLOW AHEAD OF THE FRONT WILL ALLOW
FOR A MODEST WARMUP WITH MAXIMA IN THE U30S ERN SHORE/NRN
NECK...LOWER TO MID 40S INLAND AND U40S FAR SOUTHERN ZONES.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
THE LONG TERM PERIOD WILL FEATURE BLO NORMAL TEMPS WITH A
PROGRESSIVE NORTHERN STREAM. HIGH PRESSURE BUILDS IN FROM THE
WEST FRIDAY AND SATURDAY. ANOTHER COLD FRONT APPROACHES FROM THE
NW AND THEN MOVES ACROSS THE REGION LATE SUNDAY. EURO HAS A QUICK
MOVING FRONTAL WAVE MOVE ACROSS THE CAROLINAS LATE SUNDAY AND OUT
TO SEA MONDAY. THERE WILL BE A CHC FOR RAIN OR SNOW WITH THIS
SYSTEM BUT CONFIDENCE FOR SIGNIFICANT WINTER WEATHER IS LOW AT
THIS POINT.
HIGH TEMPERATURES ARE FORECAST IN THE UPR 30S AND 40S THURSDAY
LOWERING TO MOSTLY 30S TO AROUND 40 SATURDAY THROUGH MONDAY. LOWS
ARE EXPECTED TO RANGE THROUGH THE 30S FRIDAY MORNING AND MOSTLY 20S
SATURDAY THROUGH MONDAY MORNINGS.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
THE EFFECTS OF THE STORM IN TERMS OF SNOW AND IFR CONDS HAVE JUST
ABOUT ENDED. THERE ARE STILL LIGHT SNOW SHOWERS OR FLURRIES SW RIC
AS OF 18Z. CLOUDS (MOSTLY MVFR CIGS) ARE THINNING OUT AND SHOULD
CLEAR LATE AFTN/EVENING. WINDS WILL CONTINUE GUSTY FROM THE N/NW
THROUGH THE TAF PERIOD AND FOLLOWED CLOSE TO LAVMOS FOR THOSE WINDS.
OUTLOOK...VFR/DRY WEATHER IS EXPECTED TUE NIGHT THROUGH THU AFTN. A
WEAK SYSTEM MAY DROP CIGS AND VSBYS IN LIGHT RAIN THU NIGHT/EARLY
FRI. A RETURN TO DRY WEATHER IS EXPECTED DURING MOST OF THE WEEKEND.
&&
.MARINE...
UPDATE...DOWNGRADED THE GALE WARNING TO SCA FLAGS FOR NRN COASTAL
WATERS FROM FENWICK ISLAND TO PARRAMORE ISLAND. WIND GUSTS HAVE
STRUGGLED TO REACH 34KT OR GREATER AT SFC BUOYS. SCA FOR NRN WATERS
WILL NOW BE IN EFFECT THROUGH MIDNIGHT WEDNESDAY NIGHT...AFTER WHICH
WINDS AND PRIMARILY SEAS WILL DROP BELOW SCA THRESHOLDS.
PREVIOUS DISCUSSION...STRONG COASTAL LOW IS LOCATED ABOUT 225 MILES
EAST OF ATLANTIC CITY NJ AS OF 4 AM. THE SFC PRESSURE GRADIENT
REMAINS VERY TIGHT...ESPECIALLY ALONG THE ATLANTIC COAST. THE ADDED
CAA AND DIURNAL EFFECTS ARE CAUSING N-NW WINDS TO EXPERIENCE A BRIEF
SURGE IN SPEEDS. SEAS HAVE QUICKLY RISEN TO 8-12FT IN SRN COASTAL
WATERS AS WELL. THE SURGE IN WINDS/SEAS IS EXPECTED TO BE BRIEF...
LASTING THROUGH SUNRISE...AFTER WHICH WINDS WILL DIMINISH SLIGHTLY
AND SEAS WILL SLOWLY SUBSIDE THROUGH THIS AFTN TO 5-7FT SRN
WATERS/6-10FT NRN WATERS...AS THE LOW TRACKS NE AND AWAY FROM THE
MID ATLANTIC COAST. FOR TONIGHT...THE STRONG LOW TRACKS TWD THE
CANADIAN MARITIMES AS HIGH PRESSURE BUILDS OVER THE OHIO VALLEY...
KEEPING A TIGHT PRESSURE GRADIENT OVER THE WATERS. PRESSURE RISES
AROUND 3MB THIS EVENING (OCCURRING BTWN 21Z TODAY AND 06Z TONIGHT)...
INDICATE THAT ANOTHER NWLY SURGE WITH GUSTS AROUND 30KT IS POSSIBLE
THIS EVENING FOR THE BAY/OCEAN AS CAA AND WRAPAROUND SHORTWAVE
ENERGY TRAVERSE THE WATERS.
HIGH PRESSURE SLOWLY BUILDS INTO THE MID ATLANTIC REGION ON WED.
CONTINUED CAA WILL KEEP NW WINDS ELEVATED WITHIN SCA THRESHOLDS
OVER ALL WATERS THROUGH THE DAY. HOWEVER...SEAS WILL SHOW A MARKED
DECREASE TO 4-5FT BY WED AFTN. ONLY CHANGE MADE TO SCA FLAGS WAS
TO EXTEND CHES BAY AND SRN COASTAL WATERS THROUGH 10 PM WED
EVENING BEFORE WINDS/SEAS FALL BELOW SCA THRESHOLDS. SEAS CONTINUE
TO SUBSIDE THRU WED EVENING AS HIGH PRESSURE SLIDES OVER THE
WATERS. A CLIPPER SYSTEM APPROACHING THE REGION ON THU WILL SHUNT
THE HIGH OVER THE SE COAST. THE COLD FRONT ASSOCIATED WITH THE
CLIPPER IS THEN EXPECTED TO CROSS THE WATERS THU NIGHT...FOLLOWED
BY POTENTIALLY SOLID SCA CONDITIONS FRI/FRI NIGHT.
&&
.TIDES/COASTAL FLOODING...
COASTAL FLOOD ADVISORY FOR OCEAN CITY HAS BEEN CANCELLED...FELL
SHORT OF MINOR FLOODING THRESHOLDS AS WINDS SHIFTED FASTER THAN
EXPECTED FROM ONSHORE E/NE MON AFTN TO OFFSHORE N/NW. DEPARTURES
HAVE BEEN BETWEEN 1.5 AND 2 FT ABOVE ASTRONOMICAL TIDE. MDL
GUIDANCE SHOWS THE UPCOMING TIDE THIS AFTN REACHING ABOVE 4 FT
MLLW...BUT THIS APPEARS WELL OVERDONE GIVEN THE N/NW WIND
DIRECTION AND CURRENT OBS AND TRENDS. NAM- BASED CBOFS GUIDANCE IS
RUNNING ABOUT 2 FT HIGHER THAN REALITY...BUT IN TERMS OF TREND
SHOWS THE TIDE THIS AFTN TO BE SLIGHTLY LOWER THAN THE HIGH TIDE
EARLIER THIS MORNING THAT ONLY PEAKED AT 3.7 FT MLLW. HAVE ISSUED
A COASTAL FLOOD STATEMENT RATHER THAN AN ADVISORY AT THIS POINT
GIVEN THE UNFAVORABLE OFFSHORE WIND FLOW.
ACRS THE LOWER BAY DEPARTURES ARE ALSO RUNNING AS HIGH AS 1.5 TO 2
FEET...BUT THIS STILL LEADS TO TIDES FALLING AT LEAST 0.5 FT SHY
OF MINOR FLOODING THIS AFTN. DEPARTURES WILL FALL TONIGHT INTO WED
WITH NO FLOODING CONCERNS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST WEDNESDAY FOR ANZ633-
635>638.
SMALL CRAFT ADVISORY UNTIL 10 PM EST WEDNESDAY FOR ANZ630>632-
634-654-656-658.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST WEDNESDAY NIGHT FOR
ANZ650-652.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAS/MAM
SHORT TERM...MAS/MAM
LONG TERM...LSA
AVIATION...LSA
MARINE...BMD
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
935 AM EST TUE JAN 27 2015
.SYNOPSIS...
A COASTAL LOW PRESSURE SYSTEM WILL RAPIDLY INTENSIFY AS IT TRACKS
NORTH NORTHEAST OFF THE NEW ENGLAND COAST THROUGH TONIGHT.
MEANWHILE...HIGH PRESSURE SLOWLY BUILDS OVER THE MID ATLANTIC
THROUGH MIDWEEK. A COLD FRONT WILL CROSS THE AREA THURSDAY
NIGHT...FOLLOWED BY HIGH PRESSURE THROUGH SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WINTER WX ADVSRYS HAVE BEEN SCALED BACK THIS MORNG AS THE SNOW HAS
ENDED IN SOME AREAS. THIS TREND WILL CONTINUE THRU THE LATE MORNG
HRS. ALSO ADDED AN SPS FOR AREAS S OF THE ADVSRY AREA WHERE UP TO
ONE INCH OF ACCUMULATION IS PSBL...BUT MAINLY ON GRASSY SFCS.
PREVIOUS DISCUSSION...
QUICK UPDATE TO CLEAR MARYLAND EASTERN SHORE COUNTIES FROM WITNER
WX ADVISORY BASED ON RADAR TRENDS. GIVEN LATEST REPORTS AND
TRAFFIC CAMS IN METRO RIC/ORF AREAS, WILL CONTINUE THEM ELSWEHERE.
EARLY MORNING RADAR MOSAIC SHOWING NARROW BAND OF PCPN DROPPING
SOUTH FROM CENTRAL PA SOUTH INTO EASTERN/CENTRAL VA. VSBY AVGG
2-4SM IN SN, AND WE`VE RECEIVED QUITE A FEW REPORTS ~1 AND A FEW
IN THE 1 1/2 TO 2" ALONG THE NORTHERN NECK INTO THE PENINSULA.
TRAFFIC CAMS SHOWING AT LEAST A COATING INTO THE TIDEWATER AREA
(CONFIRMED BY LOCAL COOPERATIVE OBSERVER). WE WILL BE MAINTAINING
WINTER HEADLINES FOR A LITTLE LONGER, WITH THIS BAND OF SNSH WELL
HANDLED BY THE HRRR EARLY THIS MORNING. NOT EXPECTING ANY LOCALES
IN NORFOLK OR RICHMOND METRO AREAS WILL RECEIVE ANY MORE THAN AN
INCH...BUT WITH THE HEADLINE ALREADY IN PLACE AND THE POTENTIAL
FOR SNOW TO CAUSE SOME IMPACTS DURING THE MORNING COMMUTE...DON`T
FEEL DROPPING THE HEADLINES IS PRUDENT ATTM. WL REVISIT HEADLINES
AT 7AM UPDATE. DO EXPECT DAY CREW WILL BE ABLE TO CLEAR HEADLINES
SHORTLY AFTER 14Z IF NOT SOONER.
HAVE BUMPED POPS UP IN TO CATEGORICAL RANGE FOR COASTAL NE NC, AND
GRADUALLY TAPERED THEM OFF ALONG THE EASTERN SHORE BY MID-LATE
MORNING. DROPPED POPS INTO NO HIGHER THAN 20% BUT HAVE KEPT
FLURRIES IN THE FORECAST FOR FAR WESTERN ZONES, AS ACCUMS NOT
ANTICIPATED.
INTENSIFYING SFC LOW WILL CONTINUE TO LIFT NE INTO NEW ENGLAND
THROUGH TONIGHT. ALL POPS DROP OFF BY EARLY AFTN, WITH STRONG CAA
BRINGING BREEZY/WINDY CONDITIONS (25-30MPH GUSTS ALONG THE
COAST/ERN SHORE), AND HOLDING HIGHS IN THE MID TO UPPER 30S (~40
IN THE PIEDMONT) UNDER A CLOUDY TO MOSTLY CLOUDY SKY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
IMPROVING WX FOR THE SHORT TERM PERIOD. FOR TUE
NIGHT/WED...AFOREMENTIONED COASTAL LOW PULLS TOWARDS ATLANTIC
CANADA AS COLD SFC HIGH PRESSURE BUILDS IN FROM THE W. CLEARING
SKY AND GRADUALLY DIMINISHING NW WINDS WILL ALLOW EARLY MORNING
LOW TEMPS TO FALL INTO THE THE 20S FOR MOST, W/ WIND CHILLS IN THE
TEENS IN MOST LOCATIONS.
HIGH PRESSURE BUILDS OVER THE LOCAL AREA ON WEDNESDAY.
TEMPERATURES REMAIN COOL WITH SHALLOW MIXING AND A NNE WIND. HIGHS
ONLY RANGING FROM THE MID 30S OVER THE LWR ERN SHORE TO THE UPR
30S TO LWR 40S ELSEWHERE. DRY AGAIN FOR WED NIGHT WITH LOWS IN THE
20S TO NEAR 30 ALONG THE COAST.
RAIN CHCS INCREASE ACROSS THE AREA LATER THU/THU NGT AS NORTHERN
STREAM SHORTWAVE TROUGH TRACKS FROM THE UPPER MIDWEST ACROSS TO
THE GREAT LAKES, WITH THE ASSOCIATED SFC LOW PUSHING ACROSS THE
NORTHERN MID-ATLANTIC INTO NEW ENGLAND BY LATE THU NGT. DAY BEGINS
PARTLY CLOUDY WITH GRADUALLY INCREASING CLOUDS. BEST FORCING
REMAINS OFF TO THE NORTH, SO HAVE CAPPED POP AT NO HIGHER THAN 30%
FOR NOW. RAIN CHANCES DIMINISH THU NGT AS SFC COLD FRONT PUSHES
ACROSS THE AREA. FOR HIGHS, SW FLOW AHEAD OF THE FRONT WILL ALLOW
FOR A MODEST WARMUP WITH MAXIMA IN THE U30S ERN SHORE/NRN
NECK...LOWER TO MID 40S INLAND AND U40S FAR SOUTHERN ZONES.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
THE LONG TERM PERIOD WILL FEATURE BLO NORMAL TEMPS WITH A
PROGRESSIVE NORTHERN STREAM. HIGH PRESSURE BUILDS IN FROM THE
WEST FRIDAY AND SATURDAY. ANOTHER COLD FRONT APPROACHES FROM THE
NW AND THEN MOVES ACROSS THE REGION LATE SUNDAY. EURO HAS A QUICK
MOVING FRONTAL WAVE MOVE ACROSS THE CAROLINAS LATE SUNDAY AND OUT
TO SEA MONDAY. THERE WILL BE A CHC FOR RAIN OR SNOW WITH THIS
SYSTEM BUT CONFIDENCE FOR SIGNIFICANT WINTER WEATHER IS LOW AT
THIS POINT.
HIGH TEMPERATURES ARE FORECAST IN THE UPR 30S AND 40S THURSDAY
LOWERING TO MOSTLY 30S TO AROUND 40 SATURDAY THROUGH MONDAY. LOWS
ARE EXPECTED TO RANGE THROUGH THE 30S FRIDAY MORNING AND MOSTLY 20S
SATURDAY THROUGH MONDAY MORNINGS.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
SNOW SHOWERS AFFECTING THE TAF SITES AS OF 12Z...WITH EITHER LOW
MVFR OR IFR CONDITIONS THROUGHOUT. SOME VARIABILITY IS ANTICIPATED
IN CIGS/VSBYS THROUGH 15Z AND HAVE GONE WITH TEMPO IFR CONDITIONS
FOR MOST TAF SITES THROUGH 14-15Z. GUSTY N/NW WINDS TO AROUND 25
KT AT ORF/KECG...AROUND 20 KT ELSEWHERE.
CONDITIONS WILL GRADUALLY IMPROVE AFTER 15Z...WITH CIGS LIFTING
TO 1500-2500 FT THEREAFTER. WINDS SHIFT MORE TO THE NW AND REMAIN
GUSTY TO AROUND 20 KT.
OUTLOOK...VFR/DRY WEATHER IS EXPECTED TUE NIGHT THROUGH THU AFTN. A
WEAK SYSTEM MAY DROP CIGS AND VSBYS IN LIGHT RAIN THU NIGHT/EARLY
FRI.
&&
.MARINE...
UPDATE...DOWNGRADED THE GALE WARNING TO SCA FLAGS FOR NRN COASTAL
WATERS FROM FENWICK ISLAND TO PARRAMORE ISLAND. WIND GUSTS HAVE
STRUGGLED TO REACH 34KT OR GREATER AT SFC BUOYS. SCA FOR NRN WATERS
WILL NOW BE IN EFFECT THROUGH MIDNIGHT WEDNESDAY NIGHT...AFTER WHICH
WINDS AND PRIMARILY SEAS WILL DROP BELOW SCA THRESHOLDS.
PREVIOUS DISCUSSION...STRONG COASTAL LOW IS LOCATED ABOUT 225 MILES
EAST OF ATLANTIC CITY NJ AS OF 4 AM. THE SFC PRESSURE GRADIENT
REMAINS VERY TIGHT...ESPECIALLY ALONG THE ATLANTIC COAST. THE ADDED
CAA AND DIURNAL EFFECTS ARE CAUSING N-NW WINDS TO EXPERIENCE A BRIEF
SURGE IN SPEEDS. SEAS HAVE QUICKLY RISEN TO 8-12FT IN SRN COASTAL
WATERS AS WELL. THE SURGE IN WINDS/SEAS IS EXPECTED TO BE BRIEF...
LASTING THROUGH SUNRISE...AFTER WHICH WINDS WILL DIMINISH SLIGHTLY
AND SEAS WILL SLOWLY SUBSIDE THROUGH THIS AFTN TO 5-7FT SRN
WATERS/6-10FT NRN WATERS...AS THE LOW TRACKS NE AND AWAY FROM THE
MID ATLANTIC COAST. FOR TONIGHT...THE STRONG LOW TRACKS TWD THE
CANADIAN MARITIMES AS HIGH PRESSURE BUILDS OVER THE OHIO VALLEY...
KEEPING A TIGHT PRESSURE GRADIENT OVER THE WATERS. PRESSURE RISES
AROUND 3MB THIS EVENING (OCCURRING BTWN 21Z TODAY AND 06Z TONIGHT)...
INDICATE THAT ANOTHER NWLY SURGE WITH GUSTS AROUND 30KT IS POSSIBLE
THIS EVENING FOR THE BAY/OCEAN AS CAA AND WRAPAROUND SHORTWAVE
ENERGY TRAVERSE THE WATERS.
HIGH PRESSURE SLOWLY BUILDS INTO THE MID ATLANTIC REGION ON WED.
CONTINUED CAA WILL KEEP NW WINDS ELEVATED WITHIN SCA THRESHOLDS
OVER ALL WATERS THROUGH THE DAY. HOWEVER...SEAS WILL SHOW A MARKED
DECREASE TO 4-5FT BY WED AFTN. ONLY CHANGE MADE TO SCA FLAGS WAS
TO EXTEND CHES BAY AND SRN COASTAL WATERS THROUGH 10 PM WED
EVENING BEFORE WINDS/SEAS FALL BELOW SCA THRESHOLDS. SEAS CONTINUE
TO SUBSIDE THRU WED EVENING AS HIGH PRESSURE SLIDES OVER THE
WATERS. A CLIPPER SYSTEM APPROACHING THE REGION ON THU WILL SHUNT
THE HIGH OVER THE SE COAST. THE COLD FRONT ASSOCIATED WITH THE
CLIPPER IS THEN EXPECTED TO CROSS THE WATERS THU NIGHT...FOLLOWED
BY POTENTIALLY SOLID SCA CONDITIONS FRI/FRI NIGHT.
&&
.TIDES/COASTAL FLOODING...
COASTAL FLOOD ADVISORY FOR OCEAN CITY HAS BEEN CANCELLED...FELL
SHORT OF MINOR FLOODING THRESHOLDS AS WINDS SHIFTED FASTER THAN
EXPECTED FROM ONSHORE E/NE MON AFTN TO OFFSHORE N/NW. DEPARTURES
HAVE BEEN BETWEEN 1.5 AND 2 FT ABOVE ASTRONOMICAL TIDE. MDL
GUIDANCE SHOWS THE UPCOMING TIDE THIS AFTN REACHING ABOVE 4 FT
MLLW...BUT THIS APPEARS WELL OVERDONE GIVEN THE N/NW WIND
DIRECTION AND CURRENT OBS AND TRENDS. NAM- BASED CBOFS GUIDANCE IS
RUNNING ABOUT 2 FT HIGHER THAN REALITY...BUT IN TERMS OF TREND
SHOWS THE TIDE THIS AFTN TO BE SLIGHTLY LOWER THAN THE HIGH TIDE
EARLIER THIS MORNING THAT ONLY PEAKED AT 3.7 FT MLLW. HAVE ISSUED
A COASTAL FLOOD STATEMENT RATHER THAN AN ADVISORY AT THIS POINT
GIVEN THE UNFAVORABLE OFFSHORE WIND FLOW.
ACRS THE LOWER BAY DEPARTURES ARE ALSO RUNNING AS HIGH AS 1.5 TO 2
FEET...BUT THIS STILL LEADS TO TIDES FALLING AT LEAST 0.5 FT SHY
OF MINOR FLOODING THIS AFTN. DEPARTURES WILL FALL TONIGHT INTO WED
WITH NO FLOODING CONCERNS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR VAZ081-089-
093-096.
WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR
VAZ070-071.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST WEDNESDAY FOR ANZ633-
635>638.
SMALL CRAFT ADVISORY UNTIL 10 PM EST WEDNESDAY FOR ANZ630>632-
634-654-656-658.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST WEDNESDAY NIGHT FOR
ANZ650-652.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAS/MAM
SHORT TERM...MAS/MAM
LONG TERM...LSA
AVIATION...LKB
MARINE...BMD
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
701 AM EST TUE JAN 27 2015
.SYNOPSIS...
A COASTAL LOW PRESSURE SYSTEM WILL RAPIDLY INTENSIFY AS IT TRACKS
NORTH NORTHEAST OFF THE NEW ENGLAND COAST THROUGH TONIGHT.
MEANWHILE...HIGH PRESSURE SLOWLY BUILDS OVER THE MID ATLANTIC
THROUGH MIDWEEK. A COLD FRONT WILL CROSS THE AREA THURSDAY
NIGHT...FOLLOWED BY HIGH PRESSURE THROUGH SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
QUICK UPDATE TO CLEAR MARYLAND EASTERN SHORE COUNTIES FROM WITNER
WX ADVISORY BASED ON RADAR TRENDS. GIVEN LATEST REPORTS AND
TRAFFIC CAMS IN METRO RIC/ORF AREAS, WILL CONTINUE THEM ELSWEHERE.
PREVIOUS DISCUSSION...
EARLY MORNING RADAR MOSAIC SHOWING NARROW BAND OF PCPN DROPPING
SOUTH FROM CENTRAL PA SOUTH INTO EASTERN/CENTRAL VA. VSBY AVGG
2-4SM IN SN, AND WE`VE RECEIVED QUITE A FEW REPORTS ~1 AND A FEW
IN THE 1 1/2 TO 2" ALONG THE NORTHERN NECK INTO THE PENINSULA.
TRAFFIC CAMS SHOWING AT LEAST A COATING INTO THE TIDEWATER AREA
(CONFIRMED BY LOCAL COOPERATIVE OBSERVER). WE WILL BE MAINTAINING
WINTER HEADLINES FOR A LITTLE LONGER, WITH THIS BAND OF SNSH WELL
HANDLED BY THE HRRR EARLY THIS MORNING. NOT EXPECTING ANY LOCALES
IN NORFOLK OR RICHMOND METRO AREAS WILL RECEIVE ANY MORE THAN AN
INCH...BUT WITH THE HEADLINE ALREADY IN PLACE AND THE POTENTIAL
FOR SNOW TO CAUSE SOME IMPACTS DURING THE MORNING COMMUTE...DON`T
FEEL DROPPING THE HEADLINES IS PRUDENT ATTM. WL REVISIT HEADLINES
AT 7AM UPDATE. DO EXPECT DAY CREW WILL BE ABLE TO CLEAR HEADLINES
SHORTLY AFTER 14Z IF NOT SOONER.
HAVE BUMPED POPS UP IN TO CATEGORICAL RANGE FOR COASTAL NE NC, AND
GRADUALLY TAPERED THEM OFF ALONG THE EASTERN SHORE BY MID-LATE
MORNING. DROPPED POPS INTO NO HIGHER THAN 20% BUT HAVE KEPT
FLURRIES IN THE FORECAST FOR FAR WESTERN ZONES, AS ACCUMS NOT
ANTICIPATED.
INTENSIFYING SFC LOW WILL CONTINUE TO LIFT NE INTO NEW ENGLAND
THROUGH TONIGHT. ALL POPS DROP OFF BY EARLY AFTN, WITH STRONG CAA
BRINGING BREEZY/WINDY CONDITIONS (25-30MPH GUSTS ALONG THE
COAST/ERN SHORE), AND HOLDING HIGHS IN THE MID TO UPPER 30S (~40
IN THE PIEDMONT) UNDER A CLOUDY TO MOSTLY CLOUDY SKY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
IMPROVING WX FOR THE SHORT TERM PERIOD. FOR TUE
NIGHT/WED...AFOREMENTIONED COASTAL LOW PULLS TOWARDS ATLANTIC
CANADA AS COLD SFC HIGH PRESSURE BUILDS IN FROM THE W. CLEARING
SKY AND GRADUALLY DIMINISHING NW WINDS WILL ALLOW EARLY MORNING
LOW TEMPS TO FALL INTO THE THE 20S FOR MOST, W/ WIND CHILLS IN THE
TEENS IN MOST LOCATIONS.
HIGH PRESSURE BUILDS OVER THE LOCAL AREA ON WEDNESDAY.
TEMPERATURES REMAIN COOL WITH SHALLOW MIXING AND A NNE WIND. HIGHS
ONLY RANGING FROM THE MID 30S OVER THE LWR ERN SHORE TO THE UPR
30S TO LWR 40S ELSEWHERE. DRY AGAIN FOR WED NIGHT WITH LOWS IN THE
20S TO NEAR 30 ALONG THE COAST.
RAIN CHCS INCREASE ACROSS THE AREA LATER THU/THU NGT AS NORTHERN
STREAM SHORTWAVE TROUGH TRACKS FROM THE UPPER MIDWEST ACROSS TO
THE GREAT LAKES, WITH THE ASSOCIATED SFC LOW PUSHING ACROSS THE
NORTHERN MID-ATLANTIC INTO NEW ENGLAND BY LATE THU NGT. DAY BEGINS
PARTLY CLOUDY WITH GRADUALLY INCREASING CLOUDS. BEST FORCING
REMAINS OFF TO THE NORTH, SO HAVE CAPPED POP AT NO HIGHER THAN 30%
FOR NOW. RAIN CHANCES DIMINISH THU NGT AS SFC COLD FRONT PUSHES
ACROSS THE AREA. FOR HIGHS, SW FLOW AHEAD OF THE FRONT WILL ALLOW
FOR A MODEST WARMUP WITH MAXIMA IN THE U30S ERN SHORE/NRN
NECK...LOWER TO MID 40S INLAND AND U40S FAR SOUTHERN ZONES.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
THE LONG TERM PERIOD WILL FEATURE BLO NORMAL TEMPS WITH A
PROGRESSIVE NORTHERN STREAM. HIGH PRESSURE BUILDS IN FROM THE
WEST FRIDAY AND SATURDAY. ANOTHER COLD FRONT APPROACHES FROM THE
NW AND THEN MOVES ACROSS THE REGION LATE SUNDAY. EURO HAS A QUICK
MOVING FRONTAL WAVE MOVE ACROSS THE CAROLINAS LATE SUNDAY AND OUT
TO SEA MONDAY. THERE WILL BE A CHC FOR RAIN OR SNOW WITH THIS
SYSTEM BUT CONFIDENCE FOR SIGNIFICANT WINTER WEATHER IS LOW AT
THIS POINT.
HIGH TEMPERATURES ARE FORECAST IN THE UPR 30S AND 40S THURSDAY
LOWERING TO MOSTLY 30S TO AROUND 40 SATURDAY THROUGH MONDAY. LOWS
ARE EXPECTED TO RANGE THROUGH THE 30S FRIDAY MORNING AND MOSTLY 20S
SATURDAY THROUGH MONDAY MORNINGS.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
SNOW SHOWERS AFFECTING THE TAF SITES AS OF 12Z...WITH EITHER LOW
MVFR OR IFR CONDITIONS THROUGHOUT. SOME VARIABILITY IS ANTICIPATED
IN CIGS/VSBYS THROUGH 15Z AND HAVE GONE WITH TEMPO IFR CONDITIONS
FOR MOST TAF SITES THROUGH 14-15Z. GUSTY N/NW WINDS TO AROUND 25
KT AT ORF/KECG...AROUND 20 KT ELSEWHERE.
CONDITIONS WILL GRADUALLY IMPROVE AFTER 15Z...WITH CIGS LIFTING
TO 1500-2500 FT THEREAFTER. WINDS SHIFT MORE TO THE NW AND REMAIN
GUSTY TO AROUND 20 KT.
OUTLOOK...VFR/DRY WEATHER IS EXPECTED TUE NIGHT THROUGH THU AFTN. A
WEAK SYSTEM MAY DROP CIGS AND VSBYS IN LIGHT RAIN THU NIGHT/EARLY
FRI.
&&
.MARINE...
UPDATE...DOWNGRADED THE GALE WARNING TO SCA FLAGS FOR NRN COASTAL
WATERS FROM FENWICK ISLAND TO PARRAMORE ISLAND. WIND GUSTS HAVE
STRUGGLED TO REACH 34KT OR GREATER AT SFC BUOYS. SCA FOR NRN WATERS
WILL NOW BE IN EFFECT THROUGH MIDNIGHT WEDNESDAY NIGHT...AFTER WHICH
WINDS AND PRIMARILY SEAS WILL DROP BELOW SCA THRESHOLDS.
PREVIOUS DISCUSSION...STRONG COASTAL LOW IS LOCATED ABOUT 225 MILES
EAST OF ATLANTIC CITY NJ AS OF 4 AM. THE SFC PRESSURE GRADIENT
REMAINS VERY TIGHT...ESPECIALLY ALONG THE ATLANTIC COAST. THE ADDED
CAA AND DIURNAL EFFECTS ARE CAUSING N-NW WINDS TO EXPERIENCE A BRIEF
SURGE IN SPEEDS. SEAS HAVE QUICKLY RISEN TO 8-12FT IN SRN COASTAL
WATERS AS WELL. THE SURGE IN WINDS/SEAS IS EXPECTED TO BE BRIEF...
LASTING THROUGH SUNRISE...AFTER WHICH WINDS WILL DIMINISH SLIGHTLY
AND SEAS WILL SLOWLY SUBSIDE THROUGH THIS AFTN TO 5-7FT SRN
WATERS/6-10FT NRN WATERS...AS THE LOW TRACKS NE AND AWAY FROM THE
MID ATLANTIC COAST. FOR TONIGHT...THE STRONG LOW TRACKS TWD THE
CANADIAN MARITIMES AS HIGH PRESSURE BUILDS OVER THE OHIO VALLEY...
KEEPING A TIGHT PRESSURE GRADIENT OVER THE WATERS. PRESSURE RISES
AROUND 3MB THIS EVENING (OCCURRING BTWN 21Z TODAY AND 06Z TONIGHT)...
INDICATE THAT ANOTHER NWLY SURGE WITH GUSTS AROUND 30KT IS POSSIBLE
THIS EVENING FOR THE BAY/OCEAN AS CAA AND WRAPAROUND SHORTWAVE
ENERGY TRAVERSE THE WATERS.
HIGH PRESSURE SLOWLY BUILDS INTO THE MID ATLANTIC REGION ON WED.
CONTINUED CAA WILL KEEP NW WINDS ELEVATED WITHIN SCA THRESHOLDS
OVER ALL WATERS THROUGH THE DAY. HOWEVER...SEAS WILL SHOW A MARKED
DECREASE TO 4-5FT BY WED AFTN. ONLY CHANGE MADE TO SCA FLAGS WAS
TO EXTEND CHES BAY AND SRN COASTAL WATERS THROUGH 10 PM WED
EVENING BEFORE WINDS/SEAS FALL BELOW SCA THRESHOLDS. SEAS CONTINUE
TO SUBSIDE THRU WED EVENING AS HIGH PRESSURE SLIDES OVER THE
WATERS. A CLIPPER SYSTEM APPROACHING THE REGION ON THU WILL SHUNT
THE HIGH OVER THE SE COAST. THE COLD FRONT ASSOCIATED WITH THE
CLIPPER IS THEN EXPECTED TO CROSS THE WATERS THU NIGHT...FOLLOWED
BY POTENTIALLY SOLID SCA CONDITIONS FRI/FRI NIGHT.
&&
.TIDES/COASTAL FLOODING...
COASTAL FLOOD ADVISORY FOR OCEAN CITY HAS BEEN CANCELLED...FELL
SHORT OF MINOR FLOODING THRESHOLDS AS WINDS SHIFTED FASTER THAN
EXPECTED FROM ONSHORE E/NE MON AFTN TO OFFSHORE N/NW. DEPARTURES
HAVE BEEN BETWEEN 1.5 AND 2 FT ABOVE ASTRONOMICAL TIDE. MDL
GUIDANCE SHOWS THE UPCOMING TIDE THIS AFTN REACHING ABOVE 4 FT
MLLW...BUT THIS APPEARS WELL OVERDONE GIVEN THE N/NW WIND
DIRECTION AND CURRENT OBS AND TRENDS. NAM- BASED CBOFS GUIDANCE IS
RUNNING ABOUT 2 FT HIGHER THAN REALITY...BUT IN TERMS OF TREND
SHOWS THE TIDE THIS AFTN TO BE SLIGHTLY LOWER THAN THE HIGH TIDE
EARLIER THIS MORNING THAT ONLY PEAKED AT 3.7 FT MLLW. HAVE ISSUED
A COASTAL FLOOD STATEMENT RATHER THAN AN ADVISORY AT THIS POINT
GIVEN THE UNFAVORABLE OFFSHORE WIND FLOW.
ACRS THE LOWER BAY DEPARTURES ARE ALSO RUNNING AS HIGH AS 1.5 TO 2
FEET...BUT THIS STILL LEADS TO TIDES FALLING AT LEAST 0.5 FT SHY
OF MINOR FLOODING THIS AFTN. DEPARTURES WILL FALL TONIGHT INTO WED
WITH NO FLOODING CONCERNS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR VAZ081-
089>091-093>098.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
VAZ073>078-084>086-099-100.
WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR
VAZ063-064-070>072-082-083.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST WEDNESDAY FOR ANZ630>632-
634-654-656-658.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST WEDNESDAY NIGHT FOR
ANZ650-652.
SMALL CRAFT ADVISORY UNTIL 6 PM EST WEDNESDAY FOR ANZ633-
635>638.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...MAS/MAM
LONG TERM...LSA
AVIATION...LKB
MARINE...BMD
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
321 AM EST TUE JAN 27 2015
.SYNOPSIS...
A COASTAL LOW PRESSURE SYSTEM WILL RAPIDLY INTENSIFY OVERNIGHT AS IT
TRACKS NORTH NORTHEAST OFF THE MID ATLANTIC AND NEW ENGLAND
COASTS. THE LOW WILL MOVE INTO THE CANADIAN MARITIMES ON
WEDNESDAY...AS HIGH PRESSURE SLOWLY BUILDS OVER THE MID ATLANTIC.
A COLD FRONT WILL CROSS THE AREA THURSDAY NIGHT...FOLLOWED BY HIGH
PRESSURE THROUGH SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE AS OF 10 PM EST...
NO CHANGES TO THE INHERITED WSW HEADLINES THIS EVENING...ALTHOUGH
CONFIDENCE IN SEEING MORE THAN AN INCH OF SNOW WITHIN THE ENTIRE
WSW IS LOW. LATEST OPERATIONAL 00Z NAM REMAINS LESS THAN IMPRESSED
WITH POTENTIAL SNOWFALL ACCUMULATIONS THRU TUESDAY MORNING. OUTSIDE
OF THE BATCH OF RAIN MOVING SOUTH OVER THE CHES BAY/EASTERN SHORE
ATTM...THE NAM AND LATEST HRRR ARE VOID OF ANY OTHER ORGANIZED
AREAS OF PCPN. AT LEAST WE HAVE BEGUN TO SEE SIGNS OF LIGHT SNOW
DEVELOPING ACROSS THE PIEDMONT/I-95 CORRIDOR THIS EVENING AS
COLDER AIR ALOFT...ASSOCIATED WITH THE APPROACHING UPPER
TROUGH...CONTINUES TO MOVE IN. HOWEVER...OTHER THAN COUNTING ON
THE UPPER TROUGH ITSELF TO GENERATE MEANINGFUL SNOW SHOWERS
OVERNIGHT/TUES MORNING...THE AREA WILL REMAIN TO FAR REMOVED FROM
THE DEEPENING SFC LOW OFFSHORE FOR SIGNIFICANT SNOW. HAVE CONTINUED TO
TRIM SNOW ACCUMULATION WORDING IN THE WSW`S THIS EVENING...AS A
COATING/HALF INCH OF SNOW MAY BE ABOUT THE WORST CASE SCENARIO
MOST PLACES. WILL MAINTAIN GENERALLY 2-3" ON THE LOWER MD EASTERN
SHORE CLOSEST TO THE SFC LOW...BUT A FURTHER REDUCTION IN SNOW
TOTALS MAY BE NECESSARY ON THE NEXT SHIFT. LOWS TONIGHT IN THE UPR
20S NW TO THE MID 30S SE. GRADUALLY IMPROVING CONDITIONS LATER
TUES MORNING INTO THE AFTERNOON.
PREVIOUS DISCUSSION...
MAIN FORECAST CHANGE WAS TO START TRIMMING BACK ON INHERITED
WINTER WX ADVSRYS AS THE LIKELIHOOD FOR 1-3IN OF SNOW HAS DECREASED
OVER MANY AREAS. WPC AND MUCH OF 12Z GUIDANCE SUPPORT THIS
IDEA...WITH THE BEST CHANCE FOR ADVSRY-LEVEL SNOWFALL STILL OVER
THE LWR MD ERN SHORE WHERE 2-4IN IS PSBL. DO NOT THINK NORFOLK AND
RICHMOND METRO AREAS WILL RECEIVE AOA 2IN...BUT WITH THE HEADLINE
ALREADY OUT AND THE POTENTIAL FOR UP TO AN INCH TO PSBLY CAUSE
SOME IMPACTS DURING THE MORNING COMMUTE...WILL KEEP THOSE AREAS
(AND AREAS N AND E) IN THE ADVSRY FOR NOW. ANOTHER ISSUE IS
TEMPS...WITH PARTS OF THE AREA STAYING JUST A TAD ABOVE FREEZING.
WILL UPDATE AS NEEDED THIS EVENG AND TNGT.
AS FOR PCPN...EXPECT MAINLY DRY CONDS DURING THE NEXT FEW HRS
ASIDE FM WORCESTER CNTY WHERE AN AREA OF RA HAS BEEN PERSISTENT.
BETTER CHANCE FOR RAIN ARRIVES THIS EVENG AS SFC LO PRES DEVELOPS
OFFSHORE. POPS RANGE FM 40-50% SW TO 70-80% NE. THE RA WILL
TRANSITION TO A RA/SN MIX THEN SN FM NW TO SE TNGT. TOTAL QPF WILL
BE UP TO A QUARTER INCH. LO TEMPS WILL RANGE FM THE UPR 20S FAR
NW TO MID 30S SE. PCPN WILL END FM W TO E ON TUE AS THE SFC LO
ADVANCES TOWARDS THE GULF OF ME AND NW CAA FLOW LEADS TO GUSTS TO
25-30 MPH NR THE CST AND LWR ERN SHORE. HI TEMPS ONLY IN THE MID
30S TO LWR 40S UNDER A CLOUDY-MSTLY CLOUDY SKY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
IMPROVING WX FOR THE SHORT TERM PERIOD. FOR TUE
NIGHT/WED...AFOREMENTIONED CSTL LO PULLS TOWARDS THE CANADIAN
MARITIMES AS SFC HI PRES SLOWLY BLDS IN FM THE W. EXPECT
DECREASING CLOUDS TUE NIGHT WITH NW WINDS. LO TEMPS WILL RANGE
THRU THE 20S...WITH WIND CHILLS IN THE TEENS IN MOST LOCATIONS.
COOL TEMPS INTO WED AS WELL...WITH HIGHS ONLY RANGING FM THE MID
30S OVER THE LWR ERN SHORE TO THE UPR 30S TO LWR 40S ELSEWHERE.
DRY AGAIN FOR WED NIGHT WITH SIMILAR TEMPS AS TUE NIGHT.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
THE LONG TERM PERIOD WILL FEATURE BLO NORMAL TEMPS WITH A
PROGRESSIVE NORTHERN STREAM. ONE LOW PRESSURE SYSTEM MOVES FROM THE
MIDWEST TO THE NORTHEAST STATES SENDING A COLD FRONT THROUGH THE
AREA LATE THURSDAY NIGHT/EARLY FRIDAY MORNING. A CHC OF RAIN IS IN
THE FORECAST MAINLY FOR THURSDAY NIGHT WITH LIGHT SNOW PSBL FAR NRN
PORTIONS OF THE AREA. HIGH PRESSURE BUILDS IN FROM THE WEST FRIDAY
AND SATURDAY. ANOTHER COLD FRONT APPROACHES FROM THE NW AND THEN
MOVES ACROSS THE REGION LATE SUNDAY. EURO HAS A QUICK MOVING FRONTAL
WAVE MOVE ACROSS THE CAROLINAS LATE SUNDAY AND OUT TO SEA MONDAY.
THERE WILL BE A CHC FOR RAIN OR SNOW WITH THIS SYSTEM BUT CONFIDENCE
FOR SIGNIFICANT WINTER WEATHER IS LOW AT THIS POINT.
HIGH TEMPERATURES ARE FORECAST IN THE UPR 30S AND 40S THURSDAY
LOWERING TO MOSTLY 30S TO AROUND 40 SATURDAY THROUGH MONDAY. LOWS
ARE EXPECTED TO RANGE THROUGH THE 30S FRIDAY MORNING AND MOSTLY 20S
SATURDAY THROUGH MONDAY MORNINGS.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
SNOW SHOWERS AFFECTING THE TAF SITES AS OF 06Z (RAIN CHANGING TO
SNOW AT KECG)...WITH EITHER LOW MVFR OR IFR CONDITIONS THROUGHOUT.
SOME VARIABILITY IS ANTICIPATED IN CIGS/VSBYS THROUGH 12Z...WILL
AVG IFR WITH CIGS JUST BELOW 1000 FT AND VSBYS OF 2-3SM. COULD
BRIEFLY SEE LIFR CONDS IN HEAVIER SNOW SHOWERS (PROBABLY MOST
LIKELY AT KORF). GUSTY N/NW WINDS TO AROUND 25 KT AT
ORF/KECG...AROUND 20 KT ELSEWHERE.
CONDITIONS WILL GRADUALLY IMPROVE AFTER 12Z...ALTHOUGH WILL HANG
ONTO IFR CIGS AT MOST SITES THROUGH AROUND 15Z...WITH CIGS LIFTING
TO 1500-2500 FT THEREAFTER. WINDS SHIFT MORE TO THE NW AND REMAIN
GUSTY TO AROUND 20 KT.
OUTLOOK...VFR/DRY WEATHER IS EXPECTED TUE NIGHT THROUGH THU AFTN. A
WEAK SYSTEM MAY DROP CIGS AND VSBYS IN LIGHT RAIN THU NIGHT/EARLY
FRI.
&&
.MARINE...
EXTENDED PERIOD OF SCA HEADLINES FORECAST THRU WEDS.
LOW PRESSURE HAS LOCATED JUST OFF THE NC/VA COAST THIS AFTERNOON.
THE LOW HAS INTENSIFIED SLIGHTLY...RESULTING IN AN UPTICK OF N-NE
WINDS OVER THE WATERS. BEGINNING TO SEE 20 KT GUSTS OVER THE
BAY/LOWER JAMES WITH GUSTS OF 30 TO 35 KT OVER THE NRN COASTAL
WATERS. SEAS HAVE RESPONDED...BUILDING TO 7 FT AT BUOY 44009. WINDS
WILL CONTINUE TO RAMP UP THRU LATE AFTERNOON WITH SOLID SCA
CONDITIONS (GUSTS TO 30 KT) EXPECTED ACROSS ALL WATERS TONIGHT AS
THE LOW INTENSIFIES RAPIDLY AND LIFTS AWAY FROM THE COAST. LOW LEVEL
CAA ALSO INTENSIFIES. GALE CONDITIONS WITH GUSTS UP TO 40 KT
EXPECTED ACROSS THE NRN COASTAL WATERS...CLOSEST TO THE STRONGEST
GRADIENT WINDS AND CAA. SEAS BUILD TO 7 TO 12 FT IN THE NRN WATERS
AND 5 TO 8 FT IN THE SRN WATERS TONIGHT. AS THE LOW LIFTS
AWAY...FLOW BACKS TO THE NW...KEEPING HIGH SEAS FROM REACHING THE
BEACHES. NO HIGH SURF PLANNED ATTM. LITTLE CHANGE TUES AS STRONG NW
FLOW PERSISTS BTWN LOW PRESSURE OFF THE NE COAST AND HIGH PRESSURE
OVER THE OH VALLEY. GALE CONDITIONS PERSIST OVER THE NRN COASTAL
WATERS THRU EARLY TUES EVENING...BEFORE SUBSIDING TO SOLID SCA
CONDITIONS. SEAS SUBSIDE TO 5-8 FT TUES-TUES NIGHT. HIGH PRESSURE
FINALLY BUILDS OVER THE WATERS LATE WEDS...ALLOWING WINDS TO
DIMINISH AOB 15 KT. SEAS SUBSIDE THRU WEDS EVENING. HIGH PRESSURE
REMAINS OVER THE WATERS THURS IN ADVANCE OF THE NEXT CLIPPER FRONT
SET TO CROSS THE WATERS THURS NIGHT.
&&
.TIDES/COASTAL FLOODING...
COASTAL FLOOD ADVISORY FOR OCEAN CITY HAS BEEN CANCELLED...FELL
SHORT OF MINOR FLOODING THRESHOLDS AS WINDS SHIFTED FASTER THAN
EXPECTED FROM ONSHORE E/NE MON AFTN TO OFFSHORE N/NW. DEPARTURES
HAVE BEEN BETWEEN 1.5 AND 2 FT ABOVE ASTRONOMICAL TIDE. MDL
GUIDANCE SHOWS THE UPCOMING TIDE THIS AFTN REACHING ABOVE 4 FT
MLLW...BUT THIS APPEARS WELL OVERDONE GIVEN THE N/NW WIND
DIRECTION AND CURRENT OBS AND TRENDS. NAM- BASED CBOFS GUIDANCE IS
RUNNING ABOUT 2 FT HIGHER THAN REALITY...BUT IN TERMS OF TREND
SHOWS THE TIDE THIS AFTN TO BE SLIGHTLY LOWER THAN THE HIGH TIDE
EARLIER THIS MORNING THAT ONLY PEAKED AT 3.7 FT MLLW. WILL
MONITOR TRENDS THROUGH MID MORNING...BUT WILL NOT ISSUE ANY
COASTAL FLOOD ADVSIORY AT THIS POINT GIVEN THE UNFAVORABLE
OFFSHORE WIND FLOW.
ACRS THE LOWER BAY DEPARTURES ARE ALSO RUNNING AS HIGH AS 1.5 TO 2
FEET...BUT THIS STILL LEADS TO TIDES FALLING AT LEAST 0.5 FT SHY
OF MINOR FLOODING THIS AFTN. DEPARTURES WILL FALL TONIGHT INTO WED
WITH NO FLOODING CONCERNS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MDZ021>025.
NC...NONE.
VA...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR VAZ081-
089>091-093>098.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
VAZ073>078-084>086-099-100.
WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR
VAZ063-064-070>072-082-083.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST WEDNESDAY FOR ANZ630>632-
634-654-656-658.
GALE WARNING UNTIL 10 PM EST THIS EVENING FOR ANZ650-652.
SMALL CRAFT ADVISORY UNTIL 6 PM EST WEDNESDAY FOR ANZ633-
635>638.
&&
$$
SYNOPSIS...JDM/MAS
NEAR TERM...JDM/MAS
SHORT TERM...MAS
LONG TERM...LSA
AVIATION...LKB
MARINE...SAM
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
112 AM EST TUE JAN 27 2015
.SYNOPSIS...
A COASTAL LOW PRESSURE SYSTEM WILL RAPIDLY INTENSIFY OVERNIGHT AS IT
TRACKS NORTH NORTHEAST OFF THE MID ATLANTIC AND NEW ENGLAND
COASTS. THE LOW WILL MOVE INTO THE CANADIAN MARITIMES ON
WEDNESDAY...AS HIGH PRESSURE SLOWLY BUILDS OVER THE MID ATLANTIC.
A COLD FRONT WILL CROSS THE AREA THURSDAY NIGHT...FOLLOWED BY HIGH
PRESSURE THROUGH SATURDAY.
&&
.NEAR TERM /THROUGH TODAY/...
UPDATE AS OF 10 PM EST...
NO CHANGES TO THE INHERITED WSW HEADLINES THIS EVENING...ALTHOUGH
CONFIDENCE IN SEEING MORE THAN AN INCH OF SNOW WITHIN THE ENTIRE
WSW IS LOW. LATEST OPERATIONAL 00Z NAM REMAINS LESS THAN IMPRESSED
WITH POTENTIAL SNOWFALL ACCUMULATIONS THRU TUESDAY MORNING. OUTSIDE
OF THE BATCH OF RAIN MOVING SOUTH OVER THE CHES BAY/EASTERN SHORE
ATTM...THE NAM AND LATEST HRRR ARE VOID OF ANY OTHER ORGANIZED
AREAS OF PCPN. AT LEAST WE HAVE BEGUN TO SEE SIGNS OF LIGHT SNOW
DEVELOPING ACROSS THE PIEDMONT/I-95 CORRIDOR THIS EVENING AS
COLDER AIR ALOFT...ASSOCIATED WITH THE APPROACHING UPPER
TROUGH...CONTINUES TO MOVE IN. HOWEVER...OTHER THAN COUNTING ON
THE UPPER TROUGH ITSELF TO GENERATE MEANINGFUL SNOW SHOWERS
OVERNIGHT/TUES MORNING...THE AREA WILL REMAIN TO FAR REMOVED FROM
THE DEEPENING SFC LOW OFFSHORE FOR SIGNIFICANT SNOW. HAVE CONTINUED TO
TRIM SNOW ACCUMULATION WORDING IN THE WSW`S THIS EVENING...AS A
COATING/HALF INCH OF SNOW MAY BE ABOUT THE WORST CASE SCENARIO
MOST PLACES. WILL MAINTAIN GENERALLY 2-3" ON THE LOWER MD EASTERN
SHORE CLOSEST TO THE SFC LOW...BUT A FURTHER REDUCTION IN SNOW
TOTALS MAY BE NECESSARY ON THE NEXT SHIFT. LOWS TONIGHT IN THE UPR
20S NW TO THE MID 30S SE. GRADUALLY IMPROVING CONDITIONS LATER
TUES MORNING INTO THE AFTERNOON.
PREVIOUS DISCUSSION...
MAIN FORECAST CHANGE WAS TO START TRIMMING BACK ON INHERITED
WINTER WX ADVSRYS AS THE LIKELIHOOD FOR 1-3IN OF SNOW HAS DECREASED
OVER MANY AREAS. WPC AND MUCH OF 12Z GUIDANCE SUPPORT THIS
IDEA...WITH THE BEST CHANCE FOR ADVSRY-LEVEL SNOWFALL STILL OVER
THE LWR MD ERN SHORE WHERE 2-4IN IS PSBL. DO NOT THINK NORFOLK AND
RICHMOND METRO AREAS WILL RECEIVE AOA 2IN...BUT WITH THE HEADLINE
ALREADY OUT AND THE POTENTIAL FOR UP TO AN INCH TO PSBLY CAUSE
SOME IMPACTS DURING THE MORNING COMMUTE...WILL KEEP THOSE AREAS
(AND AREAS N AND E) IN THE ADVSRY FOR NOW. ANOTHER ISSUE IS
TEMPS...WITH PARTS OF THE AREA STAYING JUST A TAD ABOVE FREEZING.
WILL UPDATE AS NEEDED THIS EVENG AND TNGT.
AS FOR PCPN...EXPECT MAINLY DRY CONDS DURING THE NEXT FEW HRS
ASIDE FM WORCESTER CNTY WHERE AN AREA OF RA HAS BEEN PERSISTENT.
BETTER CHANCE FOR RAIN ARRIVES THIS EVENG AS SFC LO PRES DEVELOPS
OFFSHORE. POPS RANGE FM 40-50% SW TO 70-80% NE. THE RA WILL
TRANSITION TO A RA/SN MIX THEN SN FM NW TO SE TNGT. TOTAL QPF WILL
BE UP TO A QUARTER INCH. LO TEMPS WILL RANGE FM THE UPR 20S FAR
NW TO MID 30S SE. PCPN WILL END FM W TO E ON TUE AS THE SFC LO
ADVANCES TOWARDS THE GULF OF ME AND NW CAA FLOW LEADS TO GUSTS TO
25-30 MPH NR THE CST AND LWR ERN SHORE. HI TEMPS ONLY IN THE MID
30S TO LWR 40S UNDER A CLOUDY-MSTLY CLOUDY SKY.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
IMPROVING WX FOR THE SHORT TERM PERIOD. FOR TUE
NIGHT/WED...AFOREMENTIONED CSTL LO PULLS TOWARDS THE CANADIAN
MARITIMES AS SFC HI PRES SLOWLY BLDS IN FM THE W. EXPECT
DECREASING CLOUDS TUE NIGHT WITH NW WINDS. LO TEMPS WILL RANGE
THRU THE 20S...WITH WIND CHILLS IN THE TEENS IN MOST LOCATIONS.
COOL TEMPS INTO WED AS WELL...WITH HIGHS ONLY RANGING FM THE MID
30S OVER THE LWR ERN SHORE TO THE UPR 30S TO LWR 40S ELSEWHERE.
DRY AGAIN FOR WED NIGHT WITH SIMILAR TEMPS AS TUE NIGHT.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
THE LONG TERM PERIOD WILL FEATURE BLO NORMAL TEMPS WITH A
PROGRESSIVE NORTHERN STREAM. ONE LOW PRESSURE SYSTEM MOVES FROM THE
MIDWEST TO THE NORTHEAST STATES SENDING A COLD FRONT THROUGH THE
AREA LATE THURSDAY NIGHT/EARLY FRIDAY MORNING. A CHC OF RAIN IS IN
THE FORECAST MAINLY FOR THURSDAY NIGHT WITH LIGHT SNOW PSBL FAR NRN
PORTIONS OF THE AREA. HIGH PRESSURE BUILDS IN FROM THE WEST FRIDAY
AND SATURDAY. ANOTHER COLD FRONT APPROACHES FROM THE NW AND THEN
MOVES ACROSS THE REGION LATE SUNDAY. EURO HAS A QUICK MOVING FRONTAL
WAVE MOVE ACROSS THE CAROLINAS LATE SUNDAY AND OUT TO SEA MONDAY.
THERE WILL BE A CHC FOR RAIN OR SNOW WITH THIS SYSTEM BUT CONFIDENCE
FOR SIGNIFICANT WINTER WEATHER IS LOW AT THIS POINT.
HIGH TEMPERATURES ARE FORECAST IN THE UPR 30S AND 40S THURSDAY
LOWERING TO MOSTLY 30S TO AROUND 40 SATURDAY THROUGH MONDAY. LOWS
ARE EXPECTED TO RANGE THROUGH THE 30S FRIDAY MORNING AND MOSTLY 20S
SATURDAY THROUGH MONDAY MORNINGS.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
SNOW SHOWERS AFFECTING THE TAF SITES AS OF 06Z (RAIN CHANGING TO
SNOW AT KECG)...WITH EITHER LOW MVFR OR IFR CONDITIONS THROUGHOUT.
SOME VARIABILITY IS ANTICIPATED IN CIGS/VSBYS THROUGH 12Z...WILL
AVG IFR WITH CIGS JUST BELOW 1000 FT AND VSBYS OF 2-3SM. COULD
BRIEFLY SEE LIFR CONDS IN HEAVIER SNOW SHOWERS (PROBABLY MOST
LIKELY AT KORF). GUSTY N/NW WINDS TO AROUND 25 KT AT
ORF/KECG...AROUND 20 KT ELSEWHERE.
CONDITIONS WILL GRADUALLY IMPROVE AFTER 12Z...ALTHOUGH WILL HANG
ONTO IFR CIGS AT MOST SITES THROUGH AROUND 15Z...WITH CIGS LIFTING
TO 1500-2500 FT THEREAFTER. WINDS SHIFT MORE TO THE NW AND REMAIN
GUSTY TO AROUND 20 KT.
OUTLOOK...VFR/DRY WEATHER IS EXPECTED TUE NIGHT THROUGH THU AFTN. A
WEAK SYSTEM MAY DROP CIGS AND VSBYS IN LIGHT RAIN THU NIGHT/EARLY
FRI.
&&
.MARINE...
EXTENDED PERIOD OF SCA HEADLINES FORECAST THRU WEDS.
LOW PRESSURE HAS LOCATED JUST OFF THE NC/VA COAST THIS AFTERNOON.
THE LOW HAS INTENSIFIED SLIGHTLY...RESULTING IN AN UPTICK OF N-NE
WINDS OVER THE WATERS. BEGINNING TO SEE 20 KT GUSTS OVER THE
BAY/LOWER JAMES WITH GUSTS OF 30 TO 35 KT OVER THE NRN COASTAL
WATERS. SEAS HAVE RESPONDED...BUILDING TO 7 FT AT BUOY 44009. WINDS
WILL CONTINUE TO RAMP UP THRU LATE AFTERNOON WITH SOLID SCA
CONDITIONS (GUSTS TO 30 KT) EXPECTED ACROSS ALL WATERS TONIGHT AS
THE LOW INTENSIFIES RAPIDLY AND LIFTS AWAY FROM THE COAST. LOW LEVEL
CAA ALSO INTENSIFIES. GALE CONDITIONS WITH GUSTS UP TO 40 KT
EXPECTED ACROSS THE NRN COASTAL WATERS...CLOSEST TO THE STRONGEST
GRADIENT WINDS AND CAA. SEAS BUILD TO 7 TO 12 FT IN THE NRN WATERS
AND 5 TO 8 FT IN THE SRN WATERS TONIGHT. AS THE LOW LIFTS
AWAY...FLOW BACKS TO THE NW...KEEPING HIGH SEAS FROM REACHING THE
BEACHES. NO HIGH SURF PLANNED ATTM. LITTLE CHANGE TUES AS STRONG NW
FLOW PERSISTS BTWN LOW PRESSURE OFF THE NE COAST AND HIGH PRESSURE
OVER THE OH VALLEY. GALE CONDITIONS PERSIST OVER THE NRN COASTAL
WATERS THRU EARLY TUES EVENING...BEFORE SUBSIDING TO SOLID SCA
CONDITIONS. SEAS SUBSIDE TO 5-8 FT TUES-TUES NIGHT. HIGH PRESSURE
FINALLY BUILDS OVER THE WATERS LATE WEDS...ALLOWING WINDS TO
DIMINISH AOB 15 KT. SEAS SUBSIDE THRU WEDS EVENING. HIGH PRESSURE
REMAINS OVER THE WATERS THURS IN ADVANCE OF THE NEXT CLIPPER FRONT
SET TO CROSS THE WATERS THURS NIGHT.
&&
.TIDES/COASTAL FLOODING...
LOW PRESSURE INTENSIFIES RAPIDLY OFF THE MID-ATLANTIC COAST
OVERNIGHT AND TUESDAY. THE RESULT WILL BE A PERIOD OF STRONG NORTH
TO NORTHWEST WINDS OVER THE WATERS. TIDAL ANOMALIES ARE FORECAST
TO REACH 1.5 TO 2.0 FT IN THE LOWER BAY AND AROUND 2.0 FT FOR THE
COASTAL AREAS OF THE ERN SHORE. MINOR FLOODING THRESHOLDS ARE
ANTICIPATED AT OCEAN CITY INLET...WITH A WATER LEVEL OF AROUND 4.0 FT.
GUIDANCE CONTINUES TO TREND DOWN FROM MODERATE FLOODING...WHICH
MAKES SENSE GIVEN A MORE NORTH TO NORTHWEST WIND DIRECTION. THE
COASTAL FLOOD WATCH HAS BEEN REPLACED WITH A COASTAL FLOOD
ADVISORY.
WATER LEVELS ARE EXPECTED TO REMAIN BELOW MINOR FLOODING THRESHOLDS
IN THE LOWER BAY...BUT WILL REACH SLIGHTLY ABOVE HIGHEST ASTRO
TIDE. ANOTHER PERIOD OF HIGH ANOMALIES ARE EXPECTED AGAIN TUESDAY...BEFORE
ANOMALIES DROP OFF TUE NGT/WED AS THE LOW LIFTS AWAY FROM THE
REGION. AFTER CURRENT ADVISORY ENDS MAY NEED TO PLACE ANOTHER ONE
IN EFFECT FOR THE TUE AFTN HIGH TIDE AT OCEAN CITY.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MDZ021>025.
COASTAL FLOOD ADVISORY UNTIL 3 AM EST EARLY THIS MORNING FOR
MDZ025.
NC...NONE.
VA...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR VAZ081-
089>091-093>098.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
VAZ073>078-084>086-099-100.
WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR
VAZ063-064-070>072-082-083.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST WEDNESDAY FOR ANZ630>638-
654-656-658.
GALE WARNING UNTIL 10 PM EST THIS EVENING FOR ANZ650-652.
&&
$$
SYNOPSIS...JDM/MAS
NEAR TERM...JDM/MAS
SHORT TERM...MAS
LONG TERM...LSA
AVIATION...LKB
MARINE...SAM
TIDES/COASTAL FLOODING...AKQ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
611 PM EST WED JAN 28 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 444 PM EST WED JAN 28 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A PAIR OF SHORTWAVES TO
THE W AND NW. ONE IS MOVING OUT OF WY/CO INTO THE WRN PLAINS AND THE
OTHER IS MOVING FROM SRN SASKATCHEWAN INTO SRN MANITOBA. AHEAD OF
THESE FEATURES...A RIBBON OF STRENGTHENING WAA/ISENTROPIC ASCENT IS
SPREADING ESE ACROSS NRN ONTARIO AND THE UPPER GREAT LAKES
UNDERNEATH RIGHT ENTRANCE OF UPPER JET CURVING FROM NRN ONTARIO DOWN
THRU THE CNTRL APPALACHIANS. REGIONAL RADARS SHOW A STREAK OF RADAR
RETURNS EXTENDING ESE FROM SE MANITOBA ACROSS ADJACENT NRN ONTARIO
AND OVER LAKE SUPERIOR/ERN UPPER MI. THE ASCENT HAS BEEN SUFFICIENT
TO ERODE DRY AIR AT THE LOWER LEVELS AND ALLOW SOME -SN TO REACH THE
GROUND FROM THE TIP OF THE KEWEENAW INTO THE NCNTRL AND ERN FCST
AREA.
PAIR OF SHORTWAVES WILL CONTINUE MOVING ESE TONIGHT WITH THE NRN
STREAM WAVE THE MORE IMPORTANT FEATURE FOR THE WEATHER HERE. AS THE
WAVE APPROACHES...ISENTROPIC ASCENT ON THE 295K SFC INCREASES
TONIGHT...MOST NOTABLY OVER THE E HALF OF UPPER MI. WHILE IT WILL BE
TOO WARM FOR ANY LAKE ENHANCEMENT OFF LAKE MICHIGAN...THE FLOW OFF
THE LAKE WILL STILL AID THE MOISTENING OF THE LOW LEVELS. OVER THE
W...THE WINDOW OF COLUMN MOISTENING IS SHORTER BEFORE THE ISENTROPIC
ASCENT DEPARTS OVERNIGHT. THUS...PCPN AMOUNTS TONIGHT WILL BE
LIGHTEST OVER THE W AND GREATER OVER THE E. 295K SFC SHOWS MIXING
RATIOS OF 3-4G/KG AVBL...SUGGESTING THE POTENTIAL FOR 3-4INCHES OF
SNOW FOR THE ROUGHLY 6HRS OF ASCENT EXPECTED. 4 INCHES IS LIKELY TOO
HIGH SINCE SNOW TO WATER RATIOS SHOULD BE ON THE LOWER SIDE. AS IT
IS...WILL PROBABLY BE CLOSE TO ADVY THRESHOLD OVER THE FAR E...
MAINLY LUCE COUNTY...AS 12HR SNOW ACCUMULATIONS FROM LATE EVENING TO
LATE THU MORNING WILL BE NEAR 3 INCHES. SNOW ACCUMULATIONS WILL BE
STEADILY LIGHTER TO THE W...DOWN TO LESS THAN 1 INCH FAR W AND ALONG
THE WI BORDER. LATE TONIGHT INTO THU MORNING...FCST SOUNDINGS
SUPPORT THE POTENTIAL FOR SOME -FZDZ AS MID LEVEL MOISTURE/SYNOPTIC
SNOW EXIT...LEAVING A LOW LEVEL MOIST LAYER THAT HAS TEMPS HIGHER
THAN -10C. WILL INCLUDE MENTION OF -FZDZ WHERE WINDS WILL BE
UPSLOPING.
COLD FRONT PASSES ACROSS UPPER MI THU MORNING. DESPITE INCREASING
WIND FIELDS...INITIAL CAA IS WEAK AS THERMAL GRADIENT IS DISPLACED
OFF TO THE NW...BUT CAA INCREASES QUICKLY IN THE AFTN. 850MB TEMPS
AROUND -10C IN THE MORNING WILL FALL TO NEAR -20C BY 00Z FRI...AND
THIS WILL RESULT IN FALLING SFC TEMPS...ESPECIALLY IN THE AFTN. LAST
OF THE SYNOPTIC SNOW WILL END OVER THE E IN THE MORNING.
OTHERWISE...THERE MAY NOT BE TOO MUCH IN THE WAY OF PCPN (-SN/-FZDZ)
DURING THE MORNING AWAY FROM AREAS THAT SEE UPSLOPING UNDER NW
WINDS. AS COLDER AIR ARRIVES IN THE AFTN...NW/NNW FLOW LES WILL
INCREASE IN COVERAGE WITH DGZ DROPPING INTO THE CONVECTIVE LAYER.
STRONG SUBSIDENCE/DEEP LAYER QVECTOR DIVERGENCE WILL LIMIT LES
INTENSITY. SO FOR THE MOST PART...EXPECT ACCUMULATIONS MOSTLY AROUND
1 INCH IN THE AFTN. STRONG WINDS WILL DISPLACE LES A LITTLE FARTHER
INLAND THAN NORMAL. SPEAKING OF WINDS...FAVORABLE POSTIONING OF PRES
RISE/FALL COUPLET WILL RESULT IN AN ADDITIVE ISALLOBARIC WIND
COMPONENT. COMBINED WITH 925MB WINDS INCREASING TO AROUND
40KT...CONDITIONS WILL BECOME BLUSTERY ACROSS THE AREA. ALONG THE
LAKE SUPERIOR SHORE AROUND THE TIP OF THE KEWEENAW AND FROM BIG BAY
EASTWARD...WINDS WILL PROBABLY GUST TO 35 TO 45 MPH IN THE AFTN.
DEPENDING ON HOW QUICKLY LES INCREASES IN THE AFTN...BLSN COULD
BECOME A SIGNIFICANT ISSUE NEAR THE LAKE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 327 PM EST WED JAN 28 2015
A SHORTWAVE TROUGH WILL BE OVER THE CWA AT 00Z FRI...WITH MOST OF
THE ASSOCIATED FORCING E OF THE CWA BY THAT TIME. NW-NNW LOW LEVEL
WINDS AND 850MB TEMPS AS LOW AS -22C WILL KEEP SNOW GOING IN THE NW-
NNW WINDS SNOWBELTS THU NIGHT...BUT A SFC RIDGE PUSHING THROUGH ON
FRI WILL LEAD TO A DIMINISHING TREND IN THE LES AS WINDS BECOME ANTI-
CYCLONIC. WINDS TURN SWLY BY FRI NIGHT BEHIND THE TROUGH AND AHEAD
OF A CLIPPER SHORTWAVE/SFC TROUGH THAT WILL MOVE THROUGH LATE FRI
NIGHT/EARLY SAT. NW WIND LES WILL RAMP UP ALONG AND BEHIND THE
TROUGH AS 850MB WINDS AS LOW AS -30C SWEEP ACROSS THE AREA. TEMPS
LOOK TO MODERATE SOME MON INTO TUE AS A RIDGE MOVES THROUGH...WITH
ANOTHER COLD BLAST SHOWN BY MODELS TOWARD THE MIDDLE OF NEXT WEEK.
OVER THE NEXT WEEK THE NW WINDS SNOWBELTS MAINLY E OF MARQUETTE WILL
SEE THE MOST SNOWFALL...WITH PROLONGED LIGHT TO MODERATE SNOWFALL.
WITH THE VERY COLD AIRMASS... GROWTH WILL BE ADVERSELY
IMPACTED...WITH SMALL SNOW FLAKES EFFICIENT AT REDUCING VIS THE
PREDOMINANT CONDITION.
COLD TEMPS ARE A CERTAINTY...ESPECIALLY SUN AND MON WHEN HIGHS WILL
NOT MAKE IT OUT OF THE SINGLE DIGITS ABOVE ZERO IN MOST LOCATIONS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 611 PM EST WED JAN 28 2015
MVFR CIGS WILL REACH KSAW THIS EVENING. AT KIWD...DOWNSLOPE WIND
COMPONENT SHOULD PREVENT THE LOWER CLOUDS IN NRN WI FROM REACHING
THE TERMINAL. DISTURBANCE APPROACHING TONIGHT WILL BRING SOME
-SN/DETERIORATING CONDITIONS. ALL TERMINALS WILL LIKELY FALL TO IFR
WITH A FEW HRS OF LIFR POSSIBLE OVERNIGHT. THERE MAY BE A LITTLE
-FZDZ LATE TONIGHT AT KIWD. PASSAGE OF COLD FRONT
EARLY THU MORNING WILL BRING INCREASING...GUSTY NW
WINDS...ESPECIALLY AT THE MORE EXPOSED KCMX TERMINAL.
OTHERWISE...EXPECT IMPROVEMENT TO MVFR AT ALL TERMINALS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 444 PM EST WED JAN 28 2015
AHEAD OF AN APPROACHING LOW PRES TROF...S WINDS OF 20-30KT ARE
EXPECTED OVER ERN LAKE SUPERIOR TONIGHT. AS IS TYPICAL FOR SOUTHERLY
WINDS...WINDS WILL BE LIGHTER OVER THE W. THE TROF WILL PASS ACROSS
THE LAKE THU MORNING. BEHIND IT...N TO NW WINDS WILL INCREASE TO 20-
30KT OVER WRN LAKE SUPERIOR. OVER THE CNTRL AND ERN LAKE...WINDS
WILL INCREASE TO GALE FORCE (GUSTS TO AROUND 40KT) FOR THU AFTN AND
NIGHT. COMBINATION OF MUCH COLDER AIR/STRONG WINDS AND BUILDING
WAVES WILL LEAD TO HVY FREEZING SPRAY THU AFTN UNTIL EARLY FRI
MORNING WHEN WINDS/WAVES DIMINISH WITH THE CLOSER APPROACH OF
CANADIAN HIGH PRES. AFTER A PERIOD OF LIGHTER WINDS MOSTLY UNDER
20KT FRI AFTN/NIGHT...WINDS WILL INCREASE AGAIN TO 20-30KT
SAT...ESPECIALLY SAT AFTN/NIGHT...IN THE WAKE OF A LOW PRES TROUGH.
GALES MAY OCCUR OVER PORTIONS OF CNTRL LAKE SUPERIOR. WINDS SHOULD
DIMINISH FOR A TIME SUN BEFORE INCREASING AGAIN MON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 1 PM THURSDAY TO 7 AM EST
FRIDAY FOR LSZ264-266-267.
GALE WARNING FROM 1 PM THURSDAY TO 4 AM EST FRIDAY FOR LSZ267.
GALE WARNING FROM 10 AM THURSDAY TO 4 AM EST FRIDAY FOR LSZ265-
266.
GALE WARNING FROM 7 AM THURSDAY TO 1 AM EST FRIDAY FOR LSZ263-
264.
HEAVY FREEZING SPRAY WARNING FROM 1 PM THURSDAY TO 1 AM EST
FRIDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...07
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
426 PM EST TUE JAN 27 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 426 PM EST TUE JAN 27 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW AN AMPLIFIED PATTERN OVER
THE CONUS...FEATURING A STRONG RIDGE OVER THE ROCKIES AND A DEEP
TROF ALONG THE E COAST. RESULTING NW FLOW INTO THE GREAT LAKES IS
QUIETER TODAY THAN YESTERDAY AS SUBTLE SHORTWAVE RIDGING IS JUST
UPSTREAM OVER NRN ONTARIO. SO...THERE IS NO PCPN OF NOTE TODAY.
THERE HAVE BEEN SOME -SHSN/FLURRIES OFF NRN LAKE MICHIGAN INTO
MENOMINEE COUNTY...AND RECENTLY FLURRIES HAVE APPEARED ON KMQT RADAR
IMAGERY IN CNTRL UPPER MI. AT THE SFC...HIGH PRES IS CENTERED OVER
SRN QUEBEC WITH RIDGE EXTENDING BACK THRU THE UPPER LAKES. DRY AIR
ASSOCIATED WITH THE HIGH HAS RESULTED IN A SUNNY DAY OVER ERN UPPER
MI...ROUGHLY E OF A MUNISING-ESCANABA LINE. LOW CLOUDS HAVE BEEN
PERSISTENT OVER THE REST OF THE AREA...THOUGH PORTIONS OF NW UPPER
MI DID HAVE MOSTLY SUNNY SKIES EARLIER TODAY.
QUIET WEATHER WILL CONTINUE TONIGHT WITH SHORTWAVE RIDGING PASSING
ACROSS THE AREA. MAIN ISSUE WILL BE CLOUD TRENDS AND THE BIG IMPACT
THE CLOUDS WILL HAVE ON TEMPS. WITH CLEAR SKIES AND LIGHT/CALM WIND
TO START THE EVENING...THE ERN FCST AREA WILL BE COLDEST TONIGHT.
LOWERED MINS TO AROUND 0F IN THAT AREA...BUT IT COULD BE 5 OR MORE
DEGREES COLDER IF SKIES REMAIN CLEAR THRU THE WHOLE EVENING.
OVERNIGHT...THERE WILL BE AN INCREASE IN CLOUDS DUE TO HIGH CLOUDS
STREAKING SE WELL AHEAD OF THE NEXT SHORTWAVE MOVING ACROSS THE SRN
CANADIAN ROCKIES AND POSSIBLY FROM LOW CLOUDS ADVECTING NE IN
DEVELOPING SW FLOW. THIS WILL PUT THE BRAKES ON COOLING AND PROBABLY
LEAD TO TEMPS RISING SOME OVERNIGHT. ACROSS THE REST OF THE FCST
AREA...THE EXPANSE OF LOW CLOUDS EXTENDING W...SW AND S OVER MUCH OF
MN AND WI SUGGESTS CLOUDS WILL DOMINATE FOR MUCH OF THE NIGHT UNDER
LOW-LEVEL S TO SW WINDS. EVEN IF LOW CLOUDS CLEAR OUT IN SOME
AREAS...HIGH AND MID CLOUDS WILL BE OVERSPREADING THE AREA. LOWS
SHOULD GENERALLY BE IN THE 15-20F RANGE.
ON WED....ONE SHORTWAVE WILL MOVE FROM THE SRN CANADIAN ROCKIES INTO
THE DAKOTAS/MANITOBA WHILE A SECOND MOVES FROM WY/CO TO THE CNTRL
PLAINS. AHEAD OF THE NRN WAVE...WAA/ISENTROPIC ASCENT WILL
STRENGTHEN AND SHIFT ESE THRU THE DAY UNDERNEATH RIGHT ENTRANCE OF
UPPER JET. WITH THE FOCUS OF MOIST ISENTROPIC ASCENT JUST TO THE N
AND WITH DRIER AIR HOLDING ON AT LOW LEVELS...THE MAIN STREAK OF
SNOW WILL REMAIN N OF HERE WED AFTN. MODEL AGREEMENT IS IN EXCELLENT
AGREEMENT ON THIS POINT. HOWEVER...THERE IS SOME UNCERTAINTY IN
WHETHER THE SRN EDGE OF THE SNOW MAY CLIP THE AREA. BASED ON
STRENGTH OF ISENTROPIC ASCENT AND TEMP/MOISTURE PROFILES ON FCST
SOUNDINGS...THE KEWEENAW AND FAR ERN FCST AREA MAY GET CLIPPED BY A
LITTLE -SN. INCLUDED ONLY SCHC/LOW CHC POPS TO REFLECT THIS
POTENTIAL. OTHERWISE...EXPECT A WARMER DAY WITH HIGHS IN THE UPPER
20S/LWR 30S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 313 PM EST TUE JAN 27 2015
AN UPPER RIDGE OVER THE WESTERN COAST OF NORTH AMERICA AND AN UPPER
LOW OVER HUDSON BAY WILL KEEP NORTHWEST FLOW OVER THE UPPER GREAT
LAKES REGION FOR MUCH OF THE LONG TERM PERIOD. THIS WILL LEAD TO
SEVERAL SHORTWAVES DROPPING SOUTHEAST ACROSS THE REGION...WHILE THE
UPPER LOW OVER HUDSON BAY GRADUALLY SINKS SOUTH TOWARDS THE AREA.
THUS...EXPECT GRADUALLY COOLING TEMPERATURES THROUGH EARLY NEXT
WEEK.
THREE PIECES OF ENERGY WITHIN THE LARGER SHORTWAVE TROUGH MOVING
THROUGH THE UPPER GREAT LAKES REGION WEDNESDAY NIGHT AND THURSDAY
WILL BE DRIVING THE WEATHER FOR THE START OF THE LONG TERM PERIOD.
THE SOUTHERN TWO WAVES WILL BE SUPPORTING THE SURFACE LOW MOVING
THROUGH SOUTHERN WISCONSIN AND THE INVERTED TROUGH CROSSING THE
UPPER GREAT LAKES REGION. AT THE START OF THE LONG TERM
PERIOD...EXPECT THE HEAVIEST PRECIPITATION TO BE ONGOING OVER
NORTHERN ONTARIO AND FAR NORTHERN LAKE SUPERIOR...WHILE THERE WILL
BE SOME SNOW OVER EASTERN UPPER MICHIGAN TIED TO THE NOSE OF THE
850-700MB WARM AIR ADVECTION INTERACTING WITH THE DEEPER MOISTURE.
THINKING MUCH OF THE REST OF THE AREA WILL BE SEEING LIMITED
PRECIPITATION CHANCES WITH THE POCKET OF DRY AIR BETWEEN 925-750MB.
THEN AS THE 850-700MB TROUGH SWEEPS SOUTHEAST THROUGH THE AREA
THROUGH THE NIGHT...EXPECT SNOW TO QUICKLY SPREAD INTO THE AREA
THROUGH THE EVENING/OVERNIGHT HOURS. WITH THAT INITIAL PRECIPITATION
STAYING TO THE NORTH OF THE LAND AREA INITIALLY...HAVE TRENDED
QPF/SNOW AMOUNTS DOWN SLIGHTLY OVER THE WEST/CENTRAL (1-2IN).
NORTHEAST OF A LINE FROM HOUGHTON TO MANISTIQUE...HAVE AMOUNTS IN
THE 2-3.5 INCH RANGE AND WILL CONTINUE TO MENTION IN THE HWO FOR
THOSE AREAS. AS THE DEEPER MOISTURE DEPARTS THURSDAY
MORNING...WILL SEE THE SNOW DIMINISH...BUT THINK THERE WILL BE
ENOUGH TERRAIN INFLUENCE TO HELP KEEP SNOW SHOWERS IN THE
NORTH-NORTHWESTERLY WIND SNOW BELTS UNTIL THE COLD AIR ARRIVES
THURSDAY AFTERNOON AND INCREASES DELTA-T VALUES TOWARDS THE LOW 20S
BY THURSDAY EVENING. THERE ARE HINTS OF LIMITED ICE CRYSTALS (AND
THUS FREEZING DRIZZLE) OVER THE WEST AS THAT DEEP MOISTURE
DEPARTS...BUT THINK IT IS TOO MARGINAL TO MENTION AT THIS POINT.
WITH THAT COLD AIR ARRIVING FROM NORTHWEST TO SOUTHEAST ON THURSDAY
AFTERNOON/EVENING...SHOULD SEE LAKE EFFECT COVERAGE INCREASING
DURING THAT TIME FRAME. WILL TREND POPS UP TO LIKELY/DEFINITE VALUES
FOR THE FAVORED NORTHWEST WIND SNOW BELTS FOR THURSDAY NIGHT. WHILE
SNOW IS EXPECTED...THERE ARE A COUPLE LIMITING FACTORS FOR HIGHER
SNOWFALL AMOUNTS. FIRST...THE APPROACHING HIGH PRESSURE RIDGE WILL
KEEP THE SUBSIDENCE INVERSION AROUND 5KFT THROUGH THE PERIOD. WHILE
MUCH OF THE CLOUD WILL BE IN OR JUST ABOVE THE DGZ...THINK THE
FRACTURING OF THE FLAKES FROM THE GUSTY WINDS WILL KEEP SNOW RATIOS
LOWER (BUT BE BETTER AT REDUCING VISIBILITIES). THUS...HAVE
SNOWFALL AMOUNTS OF 1-4 INCHES IN THE FAVORED SNOW BELTS DURING THAT
PERIOD. AS THE HIGH MOVES JUST SOUTH OF THE AREA ON FRIDAY...EXPECT
WINDS TO BACK TOWARDS THE WEST AND LOWER THE SUBSIDENCE INVERSION
TOWARDS 4KFT. THEREFORE...WILL GRADUALLY DIMINISH PRECIPITATION
CHANCES THROUGH FRIDAY AS WINDS BACK TO THE SOUTHWEST ON FRIDAY
NIGHT.
THE NEXT CLIPPER WILL SWEEP ACROSS THE AREA SATURDAY AND DRAG A WEAK
SURFACE TROUGH WITH IT. STILL SOME DIFFERENCES IN THE TIMING WITH
THIS FEATURE...SO WILL GO WITH LOW END CHANCE POPS SPREADING ACROSS
THE CWA ON SATURDAY. OVERALL...LOOKS LIKE JUST A QUICK DUSTING OF
SNOW WITH THIS FEATURE. BEHIND THE TROUGH...COLD AIR WILL FILTER
BACK INTO THE UPPER GREAT LAKES REGION AND BRING ANOTHER PERIOD OF
LAKE EFFECT FOR THE NORTH-NORTHWEST WIND SNOWBELTS. ONCE AGAIN...THE
HIGH PRESSURE RIDGE NOSING EAST INTO THE AREA WILL KEEP THE
SUBSIDENCE INVERSION AROUND 5KFT AND KEEP THE LAKE EFFECT AMOUNTS ON
THE LIGHT SIDE. ONE ITEM TO WATCH IS THE POTENTIAL FOR A WEAK
SHORTWAVE SLIDING ACROSS THE AREA ON MONDAY. THERE ARE HINTS THAT
THIS MAY RAISE INVERSION HEIGHTS TOWARDS 7-10KFT...WHICH WOULD
PROVIDE THE POTENTIAL FOR MODERATE LAKE EFFECT. WHEN THAT
OCCURS...WITH ANOTHER SURGE OF COLD AIR (850MB TEMPS FALLING TO THE
MID -20S) THE CLOUD WILL BE WELL ABOVE THE DGZ AND SUPPORT SMALL
FLAKES THAT ARE HIGHLY EFFICIENT AT REDUCING VISIBILITY. WITH THE
HIGH MOVING SOUTHEAST FROM THE NORTHERN PLAINS ON MONDAY MORNING TO
THE OHIO RIVER VALLEY ON TUESDAY...EXPECT GRADUALLY BACKING WINDS
OVER LAKE SUPERIOR AND WILL FOLLOW THAT IDEA FOR AT LEAST LIKELY
POPS FOR THE FAVORED WIND DIRECTIONS THROUGH TUESDAY (WINDS NEAR
WESTERLY BY TUESDAY EVENING). WON/T MENTION IN THE HWO AT THIS
POINT...AS AMOUNTS WILL BE ON THE LOW SIDE...BUT MAY NEED TO ADDRESS
THE END OF THE WEEK LAKE EFFECT AND THE SUN-TUE LAKE EFFECT IN THE
FUTURE DUE TO THE LIKELY LOW VISIBILITIES IN THE STRONGER BANDS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1238 PM EST TUE JAN 27 2015
LINGERING LOW CLOUDS WILL BE SLOW TO EXIT OVER MUCH OF THE W HALF OF
UPPER MI THIS AFTN/EVENING UNDER LIGHT WIND FIELDS. AT KIWD/KSAW...
MVFR CIGS ARE LIKELY TO LINGER INTO THE EVENING. SLIGHT
STRENGTHENING OF DOWNSLOPE WIND SHOULD ALLOW MVFR CIGS TO SCATTER
OUT AT KIWD LATE THIS EVENING. IT MAY NOT BE UNTIL OVERNIGHT THAT
MVFR CIGS SCATTER OUT AT KSAW. RECENT VIS SATELLITE IMAGERY SHOWS
GRADUAL EXPANSION OF LOWER CLOUDS TOWARD KCMX. SO...IT APPEARS MVFR
CIGS WILL LIKELY DEVELOP AT KCMX IN THE NEXT COUPLE OF HRS...AND
THEN LINGER THRU THE EVENING. VFR CONDITIONS SHOULD BE THE RULE AT
ALL TERMINALS LATE TONIGHT THRU WED MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 426 PM EST TUE JAN 27 2015
WINDS WILL REMAIN UNDER 20KT TONIGHT/WED. LOW PRES WILL THEN TRACK
FROM THE MID AND UPPER MISSISSIPPI VALLEY WED EVENING TO THE LOWER
LAKES BY LATE THU EVENING. AHEAD OF THE LOW...S WINDS WILL INCREASE
FOR A TIME WED NIGHT...MAINLY OVER ERN LAKE SUPERIOR WHERE WINDS
WILL REACH 20-30KT. BEHIND THE LOW ON THU...N TO NW WINDS WILL
INCREASE TO 20-30KT OVER WRN LAKE SUPERIOR. OVER THE CNTRL AND ERN
LAKE...WINDS WILL INCREASE TO GALE FORCE FOR THU AFTN AND NIGHT.
COMBINATION OF MUCH COLDER AIR/STRONG WINDS AND BUILDING WAVES WILL
LEAD TO HVY FREEZING SPRAY THU AFTN UNTIL LATE FRI MORNING WHEN
WINDS/WAVES DIMINISH WITH THE CLOSER APPROACH OF CANADIAN HIGH PRES.
AFTER A PERIOD OF LIGHTER WINDS MOSTLY UNDER 20KT FRI INTO SAT
MORNING...N WINDS WILL INCREASE TO 20-30KT LATER SAT INTO SUN
IN THE WAKE OF A LOW PRES TROUGH.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
313 PM EST TUE JAN 27 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 409 AM EST TUE JAN 27 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NW FLOW ALOFT OVER
THE GREAT LKS BTWN HI AMPLITUDE RDG OVER THE ROCKIES AND DEEP TROF
OVER THE E SUPPORTING INTENSE WINTER STORM THAT IS IMPACTING NEW
ENGLAND. SHRTWV DIGGING SEWD WITHIN THIS NW FLOW/DEEPER CLDS THAT
CAUSED PERIOD OF SN LAST EVNG ARE NOW SE OF THE AREA...SO LINGERING
LIGHT SN OVER THE CENTRAL CWA IS DIMINISHING WITH THE APRCH OF
SHRTWV RDG AXIS/DNVA/DEEP LYR QVECTOR CNVGC AND DRIER MID LVL AIR
SHOWN ON THE 00Z INL/YPL RAOBS. THESE RAOBS SHOW SOME LLVL MSTR BLO
INVRN...SO PLENTY OF LO CLDS LINGER UPSTREAM OVER NRN MN/NW ONTARIO.
HOWEVER...WITH 00Z H85 TEMP ONLY -5C AT INL...THE INCOMING AIRMASS
IS NOT SUFFICIENTLY COLD TO SUPPORT LES. COLDER AND DRIER LLVL AIR
IS STILL PRESENT TOWARD THE E AND ARCTIC HI PRES IN QUEBEC...WITH
MOCLR SKIES REPORTED EARLY THIS MRNG AT NEWBERRY AND THE SAULT.
MAIN FCST CONCERNS FOR TODAY/TNGT WL BE CLD TRENDS/IMPACT ON TEMPS.
TODAY...UPR MI WL BE DOMINATED BY DNVA/DEEP LYR QVECTOR DVGC
ASSOCIATED WITH APRCHG SHRTWV RDG. SO AFTER ANY LINGERING LIGHT SN
ENDS EARLY THIS MRNG...THE DAY SHOULD BE DRY AS SFC RDG AXIS
EXTENDING WSW FM THE HI CENTER IN QUEBEC SHIFTS OVER THE CWA.
DESPITE THE MID LVL DRYING...LINGERING LLVL MSTR TRAPPED BLO
LOWERING/STRENGTHENING SUBSIDENCE INVRN WL LIKELY MAINTAIN GENERALLY
MOCLDY SKIES...IN LINE WITH UPSTREAM OBS. ONE EXCEPTION SHOULD BE
THE ERN CWA...WHERE LIGHT E WIND WL MAINTAIN THE LLVL DRY AIR AND
ALLOW FOR MOSUNNY SKIES. ANOTHER AREA THAT MAY SEE SOME CLRG IS NEAR
LK SUP OVER THE NW CWA WHERE THE LLVL SW FLOW ON THE NRN FLANK OF
THE SFC RDG AXIS WL DOWNSLOPE AND RESULT IN LOWERING THE INVRN BASE
FURTHER. GOING FCST HI TEMPS MAINLY IN THE 20S...COLDEST OVER THE
E AND WARMEST OVER THE W...LOOK TO BE IN GOOD SHAPE.
TNGT...A SHRTWV IS FCST TO TRACK THRU FAR NRN ONTARIO. ALTHOUGH
LINGERING SHRTWV RDG AXIS WL FORCE THIS DISTURBANCE TO PASS TOO FAR
TO THE N TO BRING PCPN TO ALL BUT FAR NRN LK SUP LATE...AN INCRSG
LLVL ACYC SW FLOW BTWN THE SFC RDG AXIS SLIDING OVER LOWER MI AND
FALLING MSLP IN ONTARIO ASSOCIATED WITH THE PASSING SHRTWV WL ADVECT
SOME DRIER AIR INTO THE CWA. THIS DRYING PLUS MORE LLVL SUBSIDENCE
ASSOCIATED WITH THE STRENGTHENING ACYC FLOW WL LIKELY BREAK UP THE
LO CLDS OVER MUCH OF THE CWA...ESPECIALLY OVER NW NEAR LK SUP WHERE
SW WINDS DOWNSLOPE. OVER THE E...THE SW FLOW OFF LK MI MIGHT DRAW
MORE LO CLDS INTO THAT AREA. DESPITE ANY CLRG OF THE LOWER CLDS...
STRONGER WINDS AND INCRSG MID/HI CLDS ON THE SRN FLANK OF THE
DISTURBANCE PASSING TO THE N WL LIMIT THE DIURNAL TEMP FALL. EXPECT
THE LOWEST MIN TEMPS OVER THE E...WHERE TEMPS WL FALL OFF QUICKLY IN
THE EVNG BEFORE THE WINDS HAVE A CHC TO PICK UP A BIT OR ANY
CLDS ROLL IN LATER.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 313 PM EST TUE JAN 27 2015
AN UPPER RIDGE OVER THE WESTERN COAST OF NORTH AMERICA AND AN UPPER
LOW OVER HUDSON BAY WILL KEEP NORTHWEST FLOW OVER THE UPPER GREAT
LAKES REGION FOR MUCH OF THE LONG TERM PERIOD. THIS WILL LEAD TO
SEVERAL SHORTWAVES DROPPING SOUTHEAST ACROSS THE REGION...WHILE THE
UPPER LOW OVER HUDSON BAY GRADUALLY SINKS SOUTH TOWARDS THE AREA.
THUS...EXPECT GRADUALLY COOLING TEMPERATURES THROUGH EARLY NEXT
WEEK.
THREE PIECES OF ENERGY WITHIN THE LARGER SHORTWAVE TROUGH MOVING
THROUGH THE UPPER GREAT LAKES REGION WEDNESDAY NIGHT AND THURSDAY
WILL BE DRIVING THE WEATHER FOR THE START OF THE LONG TERM PERIOD.
THE SOUTHERN TWO WAVES WILL BE SUPPORTING THE SURFACE LOW MOVING
THROUGH SOUTHERN WISCONSIN AND THE INVERTED TROUGH CROSSING THE
UPPER GREAT LAKES REGION. AT THE START OF THE LONG TERM
PERIOD...EXPECT THE HEAVIEST PRECIPITATION TO BE ONGOING OVER
NORTHERN ONTARIO AND FAR NORTHERN LAKE SUPERIOR...WHILE THERE WILL
BE SOME SNOW OVER EASTERN UPPER MICHIGAN TIED TO THE NOSE OF THE
850-700MB WARM AIR ADVECTION INTERACTING WITH THE DEEPER MOISTURE.
THINKING MUCH OF THE REST OF THE AREA WILL BE SEEING LIMITED
PRECIPITATION CHANCES WITH THE POCKET OF DRY AIR BETWEEN 925-750MB.
THEN AS THE 850-700MB TROUGH SWEEPS SOUTHEAST THROUGH THE AREA
THROUGH THE NIGHT...EXPECT SNOW TO QUICKLY SPREAD INTO THE AREA
THROUGH THE EVENING/OVERNIGHT HOURS. WITH THAT INITIAL PRECIPITATION
STAYING TO THE NORTH OF THE LAND AREA INITIALLY...HAVE TRENDED
QPF/SNOW AMOUNTS DOWN SLIGHTLY OVER THE WEST/CENTRAL (1-2IN).
NORTHEAST OF A LINE FROM HOUGHTON TO MANISTIQUE...HAVE AMOUNTS IN
THE 2-3.5 INCH RANGE AND WILL CONTINUE TO MENTION IN THE HWO FOR
THOSE AREAS. AS THE DEEPER MOISTURE DEPARTS THURSDAY
MORNING...WILL SEE THE SNOW DIMINISH...BUT THINK THERE WILL BE
ENOUGH TERRAIN INFLUENCE TO HELP KEEP SNOW SHOWERS IN THE
NORTH-NORTHWESTERLY WIND SNOW BELTS UNTIL THE COLD AIR ARRIVES
THURSDAY AFTERNOON AND INCREASES DELTA-T VALUES TOWARDS THE LOW 20S
BY THURSDAY EVENING. THERE ARE HINTS OF LIMITED ICE CRYSTALS (AND
THUS FREEZING DRIZZLE) OVER THE WEST AS THAT DEEP MOISTURE
DEPARTS...BUT THINK IT IS TOO MARGINAL TO MENTION AT THIS POINT.
WITH THAT COLD AIR ARRIVING FROM NORTHWEST TO SOUTHEAST ON THURSDAY
AFTERNOON/EVENING...SHOULD SEE LAKE EFFECT COVERAGE INCREASING
DURING THAT TIME FRAME. WILL TREND POPS UP TO LIKELY/DEFINITE VALUES
FOR THE FAVORED NORTHWEST WIND SNOW BELTS FOR THURSDAY NIGHT. WHILE
SNOW IS EXPECTED...THERE ARE A COUPLE LIMITING FACTORS FOR HIGHER
SNOWFALL AMOUNTS. FIRST...THE APPROACHING HIGH PRESSURE RIDGE WILL
KEEP THE SUBSIDENCE INVERSION AROUND 5KFT THROUGH THE PERIOD. WHILE
MUCH OF THE CLOUD WILL BE IN OR JUST ABOVE THE DGZ...THINK THE
FRACTURING OF THE FLAKES FROM THE GUSTY WINDS WILL KEEP SNOW RATIOS
LOWER (BUT BE BETTER AT REDUCING VISIBILITIES). THUS...HAVE
SNOWFALL AMOUNTS OF 1-4 INCHES IN THE FAVORED SNOW BELTS DURING THAT
PERIOD. AS THE HIGH MOVES JUST SOUTH OF THE AREA ON FRIDAY...EXPECT
WINDS TO BACK TOWARDS THE WEST AND LOWER THE SUBSIDENCE INVERSION
TOWARDS 4KFT. THEREFORE...WILL GRADUALLY DIMINISH PRECIPITATION
CHANCES THROUGH FRIDAY AS WINDS BACK TO THE SOUTHWEST ON FRIDAY
NIGHT.
THE NEXT CLIPPER WILL SWEEP ACROSS THE AREA SATURDAY AND DRAG A WEAK
SURFACE TROUGH WITH IT. STILL SOME DIFFERENCES IN THE TIMING WITH
THIS FEATURE...SO WILL GO WITH LOW END CHANCE POPS SPREADING ACROSS
THE CWA ON SATURDAY. OVERALL...LOOKS LIKE JUST A QUICK DUSTING OF
SNOW WITH THIS FEATURE. BEHIND THE TROUGH...COLD AIR WILL FILTER
BACK INTO THE UPPER GREAT LAKES REGION AND BRING ANOTHER PERIOD OF
LAKE EFFECT FOR THE NORTH-NORTHWEST WIND SNOWBELTS. ONCE AGAIN...THE
HIGH PRESSURE RIDGE NOSING EAST INTO THE AREA WILL KEEP THE
SUBSIDENCE INVERSION AROUND 5KFT AND KEEP THE LAKE EFFECT AMOUNTS ON
THE LIGHT SIDE. ONE ITEM TO WATCH IS THE POTENTIAL FOR A WEAK
SHORTWAVE SLIDING ACROSS THE AREA ON MONDAY. THERE ARE HINTS THAT
THIS MAY RAISE INVERSION HEIGHTS TOWARDS 7-10KFT...WHICH WOULD
PROVIDE THE POTENTIAL FOR MODERATE LAKE EFFECT. WHEN THAT
OCCURS...WITH ANOTHER SURGE OF COLD AIR (850MB TEMPS FALLING TO THE
MID -20S) THE CLOUD WILL BE WELL ABOVE THE DGZ AND SUPPORT SMALL
FLAKES THAT ARE HIGHLY EFFICIENT AT REDUCING VISIBILITY. WITH THE
HIGH MOVING SOUTHEAST FROM THE NORTHERN PLAINS ON MONDAY MORNING TO
THE OHIO RIVER VALLEY ON TUESDAY...EXPECT GRADUALLY BACKING WINDS
OVER LAKE SUPERIOR AND WILL FOLLOW THAT IDEA FOR AT LEAST LIKELY
POPS FOR THE FAVORED WIND DIRECTIONS THROUGH TUESDAY (WINDS NEAR
WESTERLY BY TUESDAY EVENING). WON/T MENTION IN THE HWO AT THIS
POINT...AS AMOUNTS WILL BE ON THE LOW SIDE...BUT MAY NEED TO ADDRESS
THE END OF THE WEEK LAKE EFFECT AND THE SUN-TUE LAKE EFFECT IN THE
FUTURE DUE TO THE LIKELY LOW VISIBILITIES IN THE STRONGER BANDS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1238 PM EST TUE JAN 27 2015
LINGERING LOW CLOUDS WILL BE SLOW TO EXIT OVER MUCH OF THE W HALF OF
UPPER MI THIS AFTN/EVENING UNDER LIGHT WIND FIELDS. AT KIWD/KSAW...
MVFR CIGS ARE LIKELY TO LINGER INTO THE EVENING. SLIGHT
STRENGTHENING OF DOWNSLOPE WIND SHOULD ALLOW MVFR CIGS TO SCATTER
OUT AT KIWD LATE THIS EVENING. IT MAY NOT BE UNTIL OVERNIGHT THAT
MVFR CIGS SCATTER OUT AT KSAW. RECENT VIS SATELLITE IMAGERY SHOWS
GRADUAL EXPANSION OF LOWER CLOUDS TOWARD KCMX. SO...IT APPEARS MVFR
CIGS WILL LIKELY DEVELOP AT KCMX IN THE NEXT COUPLE OF HRS...AND
THEN LINGER THRU THE EVENING. VFR CONDITIONS SHOULD BE THE RULE AT
ALL TERMINALS LATE TONIGHT THRU WED MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 409 AM EST TUE JAN 27 2015
EXPECT S TO SW WINDS UNDER 20 KTS TO DOMINATE THRU WED AS A HI PRES
RIDGE OVER UPPER MI TODAY SINKS SLOWLY INTO THE LOWER GREAT LAKES.
ON THE NORTHERN FLANK OF A HI PRES RIDGE ORIENTED ACROSS THE CENTRAL
GREAT LAKES. LO PRES WILL THEN TRACK FROM THE MID MISSISSIPPI VALLEY
WED NIGHT TO THE LOWER LAKES THU NIGHT. BEHIND THE LOW...N TO NW
WINDS WILL INCREASE TO 20-30KT AND THEN TO GALE FORCE LATE THU AND
THU NIGHT. SINCE THESE STRONG WINDS WILL DRAW MUCH COLDER ARCTIC AIR
INTO THE UPPER LAKES...HEAVY FREEZING SPRAY WILL DEVELOP OVER MUCH
OF THE LAKE AND CONTINUE INTO FRI...WHEN WINDS/WAVES WILL DIMINISH
WITH THE CLOSER APPROACH OF CANADIAN HI PRES. ANOTHER DISTURBANCE
AND COLD FRONT MAY SWING ACROSS THE UPPER LAKES ON SAT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1238 PM EST TUE JAN 27 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 409 AM EST TUE JAN 27 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NW FLOW ALOFT OVER
THE GREAT LKS BTWN HI AMPLITUDE RDG OVER THE ROCKIES AND DEEP TROF
OVER THE E SUPPORTING INTENSE WINTER STORM THAT IS IMPACTING NEW
ENGLAND. SHRTWV DIGGING SEWD WITHIN THIS NW FLOW/DEEPER CLDS THAT
CAUSED PERIOD OF SN LAST EVNG ARE NOW SE OF THE AREA...SO LINGERING
LIGHT SN OVER THE CENTRAL CWA IS DIMINISHING WITH THE APRCH OF
SHRTWV RDG AXIS/DNVA/DEEP LYR QVECTOR CNVGC AND DRIER MID LVL AIR
SHOWN ON THE 00Z INL/YPL RAOBS. THESE RAOBS SHOW SOME LLVL MSTR BLO
INVRN...SO PLENTY OF LO CLDS LINGER UPSTREAM OVER NRN MN/NW ONTARIO.
HOWEVER...WITH 00Z H85 TEMP ONLY -5C AT INL...THE INCOMING AIRMASS
IS NOT SUFFICIENTLY COLD TO SUPPORT LES. COLDER AND DRIER LLVL AIR
IS STILL PRESENT TOWARD THE E AND ARCTIC HI PRES IN QUEBEC...WITH
MOCLR SKIES REPORTED EARLY THIS MRNG AT NEWBERRY AND THE SAULT.
MAIN FCST CONCERNS FOR TODAY/TNGT WL BE CLD TRENDS/IMPACT ON TEMPS.
TODAY...UPR MI WL BE DOMINATED BY DNVA/DEEP LYR QVECTOR DVGC
ASSOCIATED WITH APRCHG SHRTWV RDG. SO AFTER ANY LINGERING LIGHT SN
ENDS EARLY THIS MRNG...THE DAY SHOULD BE DRY AS SFC RDG AXIS
EXTENDING WSW FM THE HI CENTER IN QUEBEC SHIFTS OVER THE CWA.
DESPITE THE MID LVL DRYING...LINGERING LLVL MSTR TRAPPED BLO
LOWERING/STRENGTHENING SUBSIDENCE INVRN WL LIKELY MAINTAIN GENERALLY
MOCLDY SKIES...IN LINE WITH UPSTREAM OBS. ONE EXCEPTION SHOULD BE
THE ERN CWA...WHERE LIGHT E WIND WL MAINTAIN THE LLVL DRY AIR AND
ALLOW FOR MOSUNNY SKIES. ANOTHER AREA THAT MAY SEE SOME CLRG IS NEAR
LK SUP OVER THE NW CWA WHERE THE LLVL SW FLOW ON THE NRN FLANK OF
THE SFC RDG AXIS WL DOWNSLOPE AND RESULT IN LOWERING THE INVRN BASE
FURTHER. GOING FCST HI TEMPS MAINLY IN THE 20S...COLDEST OVER THE
E AND WARMEST OVER THE W...LOOK TO BE IN GOOD SHAPE.
TNGT...A SHRTWV IS FCST TO TRACK THRU FAR NRN ONTARIO. ALTHOUGH
LINGERING SHRTWV RDG AXIS WL FORCE THIS DISTURBANCE TO PASS TOO FAR
TO THE N TO BRING PCPN TO ALL BUT FAR NRN LK SUP LATE...AN INCRSG
LLVL ACYC SW FLOW BTWN THE SFC RDG AXIS SLIDING OVER LOWER MI AND
FALLING MSLP IN ONTARIO ASSOCIATED WITH THE PASSING SHRTWV WL ADVECT
SOME DRIER AIR INTO THE CWA. THIS DRYING PLUS MORE LLVL SUBSIDENCE
ASSOCIATED WITH THE STRENGTHENING ACYC FLOW WL LIKELY BREAK UP THE
LO CLDS OVER MUCH OF THE CWA...ESPECIALLY OVER NW NEAR LK SUP WHERE
SW WINDS DOWNSLOPE. OVER THE E...THE SW FLOW OFF LK MI MIGHT DRAW
MORE LO CLDS INTO THAT AREA. DESPITE ANY CLRG OF THE LOWER CLDS...
STRONGER WINDS AND INCRSG MID/HI CLDS ON THE SRN FLANK OF THE
DISTURBANCE PASSING TO THE N WL LIMIT THE DIURNAL TEMP FALL. EXPECT
THE LOWEST MIN TEMPS OVER THE E...WHERE TEMPS WL FALL OFF QUICKLY IN
THE EVNG BEFORE THE WINDS HAVE A CHC TO PICK UP A BIT OR ANY
CLDS ROLL IN LATER.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 502 AM EST TUE JAN 27 2015
MUCH OF THIS PERIOD WILL BE IMPACTED BY THE STEADY 500MB LOW OVER E
AND E CANADA. FROM TIME TO TIME IT WILL BE EXTENDING A TROUGH ACROSS
MUCH OF THE E HALF OF THE U.S.
WARMEST DAY THIS PERIOD WILL BE WEDNESDAY...WITH HIGHS GENERALLY 30-
35F ON LIGHT S FLOW. A LOW OVER N HUDSON BAY AND AN ADDITIONAL LOW
ACROSS THE N/CENTRAL PLAINS WILL PUSH A TROUGH OVER LAKE SUPERIOR
WEDNESDAY NIGHT. THIS WILL BRING THE BEST CHANCE OF WIDESPREAD SNOW
THROUGH THE LONG TERM PERIOD. HAVE ADJUSTED THE HWO MESSAGE TO
INCLUDE MAINLY THE TIP OF THE KEWEENAW AND E OF A LINE FROM MQT TO
ESC FOR THE POTENTIAL FOR MODERATE SNOW AMOUNTS. EXACT AMOUNTS VARY
SIGNIFICANTLY DEPENDING ON WHAT MODEL IS USED. FOR EXAMPLE AT KSAW
FOR WEDNESDAY NIGHT BUFKIT IS INDICATING THE POTENTIAL FOR 1-2IN
/00Z AND 06Z MODEL RUNS/. THE GFS IS SHOWING CLOSER TO 4-6IN. TAKING
A LOOK AT THE PRECIP FIELDS...THE 27/00Z ECMWF ALIGNS BETTER WITH
THE NAM WHILE THE CANADIAN IS CLOSER TO THE GFS. WILL CONTINUE A
FCST OF 2-5IN FOR MUCH OF THE CWA FROM WED THROUGH THURSDAY...WITH
ONLY 1-2IN ALONG THE WI BORDER. ONLY LIMITED SNOW IS EXPECTED OVER
THE UPSLOPE N CENTRAL AND E LOCATIONS BAST WEDNESDAY NIGHT/THURSDAY
MORNING.
THE TROUGH WILL WEAKEN THURSDAY/THURSDAY NIGHT AS THE LOW ACROSS THE
PLAINS SHIFTS TO S LOWER MI...AND THE NEW ENGLAND STATES.
HOWEVER...INCREASED N-NNW WINDS THURSDAY AFTERNOON LOOK
REASONABLE...WITH A 30-40KT LLJ SET UP...EXPECT ABOVE 925MB. THIS
WILL BE AS UPPER MI BECOMES STUCK BETWEEN THE EXITING LOW PUSHING
TOWARDS THE LOWER GREAT LAKES AND STRONG HIGH PRESSURE NEARING FROM
THE W. LOOK FOR PATCHY BLOWING SNOW TO DEVELOP THURSDAY ALONG LAKE
SUPERIOR...REDUCING VIS.
FRIDAY INTO EARLY SATURDAY... EXPECT THE HIGH MENTIONED ABOVE OVER
SASKATCHEWAN ON THURSDAY TO SINK ACROSS MN AND W LAKE SUPERIOR
FRIDAY MORNING...AND INTO THE OHIO VALLEY AND MID ATLANTIC STATES
SATURDAY. COLD AIR WILL BE OVERHEAD...WITH HIGHS IN THE LOW TO MID
TEENS FRIDAY. WHILE LOW LEVEL MOISTURE AROUND 800MB AND BELOW WILL
REMAIN TRAPPED UNDER THE LOWERING INVERSION THURSDAY-FRIDAY...AND
THE DGZ WILL BE WITHIN THIS MOISTURE LAYER...NO HEADLINE LES IS
ANTICIPATED. THIS WILL BE EVEN THROUGH SLR VALUES CLIMB BACK TO 20-
25:1. LESS THAN FAVORABLE W-SW WINDS FRIDAY EVENING SHOULD PUSH MUCH
IF NOT ALL OF THE LINGERING LIGHT SNOW SHOWERS BACK INTO LAKE
SUPERIOR. THE DRY WEATHER WILL ONLY BE TEMPORARY.
REST OF SATURDAY... A BRIEF TROUGH OF LOW PRESSURE WILL PUSH ACROSS
LAKE SUPERIOR ON SATURDAY...BEFORE STRONGER HIGH PRESSURE NEARS FROM
CENTRAL CANADA. TIMING THIS TROUGH IS IS STILL A BIT ROUGH...AS THE
GFS/ECMWF/CANADIAN DIFFER BY 6-12HRS. THE 27/00Z CANDIAN AND 26/12Z
ECMWF ARE PRETTY CONSISTANT...WHILE THE 27/00Z GFS IS ON THE SLOW
SIDE. EITHER WAY IT WILL USHER IN ANOTHER ROUND OF COLD AIR. HIGHS
SUNDAY SHOULD TOP OUT 10-17F.
SUNDAY THROUGH MONDAY... STRONGER AND COLD 30.9 INCH/1040-1050MB
HIGH PRESSURE OVER MUCH OF CENTRAL CANADA FRIDAY AND SATURDAY WILL
SLOWLY WEAKEN TO 30.6IN/1033-1037MB AS IT SETTLES ACROSS THE N
PLAINS/ UPPER MS VALLEY/UPPER GREAT LAKES TO START THE NEXT WORK
WEEK. HIGHS MONDAY MAY ONLY BE IN THE SINGLE DIGITS ABOVE ZERO.
THE HIGH WILL CONTINUE TO SINK SE ACROSS THE MID MS VALLEY/OHIO
VALLEY MONDAY NIGHT...AND MID ATLANTIC STATES TUESDAY-WEDNESDAY. THE
GFS IS PERSISTENT IN KEEPING THE HIGH IN PLACE...WHILE THE 26/12Z
ECMWF IS MORE PROGRESSIVE. MORE ON THIS WHEN WE START FCSTING FOR
MID NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1238 PM EST TUE JAN 27 2015
LINGERING LOW CLOUDS WILL BE SLOW TO EXIT OVER MUCH OF THE W HALF OF
UPPER MI THIS AFTN/EVENING UNDER LIGHT WIND FIELDS. AT KIWD/KSAW...
MVFR CIGS ARE LIKELY TO LINGER INTO THE EVENING. SLIGHT
STRENGTHENING OF DOWNSLOPE WIND SHOULD ALLOW MVFR CIGS TO SCATTER
OUT AT KIWD LATE THIS EVENING. IT MAY NOT BE UNTIL OVERNIGHT THAT
MVFR CIGS SCATTER OUT AT KSAW. RECENT VIS SATELLITE IMAGERY SHOWS
GRADUAL EXPANSION OF LOWER CLOUDS TOWARD KCMX. SO...IT APPEARS MVFR
CIGS WILL LIKELY DEVELOP AT KCMX IN THE NEXT COUPLE OF HRS...AND
THEN LINGER THRU THE EVENING. VFR CONDITIONS SHOULD BE THE RULE AT
ALL TERMINALS LATE TONIGHT THRU WED MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 409 AM EST TUE JAN 27 2015
EXPECT S TO SW WINDS UNDER 20 KTS TO DOMINATE THRU WED AS A HI PRES
RIDGE OVER UPPER MI TODAY SINKS SLOWLY INTO THE LOWER GREAT LAKES.
ON THE NORTHERN FLANK OF A HI PRES RIDGE ORIENTED ACROSS THE CENTRAL
GREAT LAKES. LO PRES WILL THEN TRACK FROM THE MID MISSISSIPPI VALLEY
WED NIGHT TO THE LOWER LAKES THU NIGHT. BEHIND THE LOW...N TO NW
WINDS WILL INCREASE TO 20-30KT AND THEN TO GALE FORCE LATE THU AND
THU NIGHT. SINCE THESE STRONG WINDS WILL DRAW MUCH COLDER ARCTIC AIR
INTO THE UPPER LAKES...HEAVY FREEZING SPRAY WILL DEVELOP OVER MUCH
OF THE LAKE AND CONTINUE INTO FRI...WHEN WINDS/WAVES WILL DIMINISH
WITH THE CLOSER APPROACH OF CANADIAN HI PRES. ANOTHER DISTURBANCE
AND COLD FRONT MAY SWING ACROSS THE UPPER LAKES ON SAT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
626 AM EST TUE JAN 27 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 409 AM EST TUE JAN 27 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NW FLOW ALOFT OVER
THE GREAT LKS BTWN HI AMPLITUDE RDG OVER THE ROCKIES AND DEEP TROF
OVER THE E SUPPORTING INTENSE WINTER STORM THAT IS IMPACTING NEW
ENGLAND. SHRTWV DIGGING SEWD WITHIN THIS NW FLOW/DEEPER CLDS THAT
CAUSED PERIOD OF SN LAST EVNG ARE NOW SE OF THE AREA...SO LINGERING
LIGHT SN OVER THE CENTRAL CWA IS DIMINISHING WITH THE APRCH OF
SHRTWV RDG AXIS/DNVA/DEEP LYR QVECTOR CNVGC AND DRIER MID LVL AIR
SHOWN ON THE 00Z INL/YPL RAOBS. THESE RAOBS SHOW SOME LLVL MSTR BLO
INVRN...SO PLENTY OF LO CLDS LINGER UPSTREAM OVER NRN MN/NW ONTARIO.
HOWEVER...WITH 00Z H85 TEMP ONLY -5C AT INL...THE INCOMING AIRMASS
IS NOT SUFFICIENTLY COLD TO SUPPORT LES. COLDER AND DRIER LLVL AIR
IS STILL PRESENT TOWARD THE E AND ARCTIC HI PRES IN QUEBEC...WITH
MOCLR SKIES REPORTED EARLY THIS MRNG AT NEWBERRY AND THE SAULT.
MAIN FCST CONCERNS FOR TODAY/TNGT WL BE CLD TRENDS/IMPACT ON TEMPS.
TODAY...UPR MI WL BE DOMINATED BY DNVA/DEEP LYR QVECTOR DVGC
ASSOCIATED WITH APRCHG SHRTWV RDG. SO AFTER ANY LINGERING LIGHT SN
ENDS EARLY THIS MRNG...THE DAY SHOULD BE DRY AS SFC RDG AXIS
EXTENDING WSW FM THE HI CENTER IN QUEBEC SHIFTS OVER THE CWA.
DESPITE THE MID LVL DRYING...LINGERING LLVL MSTR TRAPPED BLO
LOWERING/STRENGTHENING SUBSIDENCE INVRN WL LIKELY MAINTAIN GENERALLY
MOCLDY SKIES...IN LINE WITH UPSTREAM OBS. ONE EXCEPTION SHOULD BE
THE ERN CWA...WHERE LIGHT E WIND WL MAINTAIN THE LLVL DRY AIR AND
ALLOW FOR MOSUNNY SKIES. ANOTHER AREA THAT MAY SEE SOME CLRG IS NEAR
LK SUP OVER THE NW CWA WHERE THE LLVL SW FLOW ON THE NRN FLANK OF
THE SFC RDG AXIS WL DOWNSLOPE AND RESULT IN LOWERING THE INVRN BASE
FURTHER. GOING FCST HI TEMPS MAINLY IN THE 20S...COLDEST OVER THE
E AND WARMEST OVER THE W...LOOK TO BE IN GOOD SHAPE.
TNGT...A SHRTWV IS FCST TO TRACK THRU FAR NRN ONTARIO. ALTHOUGH
LINGERING SHRTWV RDG AXIS WL FORCE THIS DISTURBANCE TO PASS TOO FAR
TO THE N TO BRING PCPN TO ALL BUT FAR NRN LK SUP LATE...AN INCRSG
LLVL ACYC SW FLOW BTWN THE SFC RDG AXIS SLIDING OVER LOWER MI AND
FALLING MSLP IN ONTARIO ASSOCIATED WITH THE PASSING SHRTWV WL ADVECT
SOME DRIER AIR INTO THE CWA. THIS DRYING PLUS MORE LLVL SUBSIDENCE
ASSOCIATED WITH THE STRENGTHENING ACYC FLOW WL LIKELY BREAK UP THE
LO CLDS OVER MUCH OF THE CWA...ESPECIALLY OVER NW NEAR LK SUP WHERE
SW WINDS DOWNSLOPE. OVER THE E...THE SW FLOW OFF LK MI MIGHT DRAW
MORE LO CLDS INTO THAT AREA. DESPITE ANY CLRG OF THE LOWER CLDS...
STRONGER WINDS AND INCRSG MID/HI CLDS ON THE SRN FLANK OF THE
DISTURBANCE PASSING TO THE N WL LIMIT THE DIURNAL TEMP FALL. EXPECT
THE LOWEST MIN TEMPS OVER THE E...WHERE TEMPS WL FALL OFF QUICKLY IN
THE EVNG BEFORE THE WINDS HAVE A CHC TO PICK UP A BIT OR ANY
CLDS ROLL IN LATER.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 502 AM EST TUE JAN 27 2015
MUCH OF THIS PERIOD WILL BE IMPACTED BY THE STEADY 500MB LOW OVER E
AND E CANADA. FROM TIME TO TIME IT WILL BE EXTENDING A TROUGH ACROSS
MUCH OF THE E HALF OF THE U.S.
WARMEST DAY THIS PERIOD WILL BE WEDNESDAY...WITH HIGHS GENERALLY 30-
35F ON LIGHT S FLOW. A LOW OVER N HUDSON BAY AND AN ADDITIONAL LOW
ACROSS THE N/CENTRAL PLAINS WILL PUSH A TROUGH OVER LAKE SUPERIOR
WEDNESDAY NIGHT. THIS WILL BRING THE BEST CHANCE OF WIDESPREAD SNOW
THROUGH THE LONG TERM PERIOD. HAVE ADJUSTED THE HWO MESSAGE TO
INCLUDE MAINLY THE TIP OF THE KEWEENAW AND E OF A LINE FROM MQT TO
ESC FOR THE POTENTIAL FOR MODERATE SNOW AMOUNTS. EXACT AMOUNTS VARY
SIGNIFICANTLY DEPENDING ON WHAT MODEL IS USED. FOR EXAMPLE AT KSAW
FOR WEDNESDAY NIGHT BUFKIT IS INDICATING THE POTENTIAL FOR 1-2IN
/00Z AND 06Z MODEL RUNS/. THE GFS IS SHOWING CLOSER TO 4-6IN. TAKING
A LOOK AT THE PRECIP FIELDS...THE 27/00Z ECMWF ALIGNS BETTER WITH
THE NAM WHILE THE CANADIAN IS CLOSER TO THE GFS. WILL CONTINUE A
FCST OF 2-5IN FOR MUCH OF THE CWA FROM WED THROUGH THURSDAY...WITH
ONLY 1-2IN ALONG THE WI BORDER. ONLY LIMITED SNOW IS EXPECTED OVER
THE UPSLOPE N CENTRAL AND E LOCATIONS BAST WEDNESDAY NIGHT/THURSDAY
MORNING.
THE TROUGH WILL WEAKEN THURSDAY/THURSDAY NIGHT AS THE LOW ACROSS THE
PLAINS SHIFTS TO S LOWER MI...AND THE NEW ENGLAND STATES.
HOWEVER...INCREASED N-NNW WINDS THURSDAY AFTERNOON LOOK
REASONABLE...WITH A 30-40KT LLJ SET UP...EXPECT ABOVE 925MB. THIS
WILL BE AS UPPER MI BECOMES STUCK BETWEEN THE EXITING LOW PUSHING
TOWARDS THE LOWER GREAT LAKES AND STRONG HIGH PRESSURE NEARING FROM
THE W. LOOK FOR PATCHY BLOWING SNOW TO DEVELOP THURSDAY ALONG LAKE
SUPERIOR...REDUCING VIS.
FRIDAY INTO EARLY SATURDAY... EXPECT THE HIGH MENTIONED ABOVE OVER
SASKATCHEWAN ON THURSDAY TO SINK ACROSS MN AND W LAKE SUPERIOR
FRIDAY MORNING...AND INTO THE OHIO VALLEY AND MID ATLANTIC STATES
SATURDAY. COLD AIR WILL BE OVERHEAD...WITH HIGHS IN THE LOW TO MID
TEENS FRIDAY. WHILE LOW LEVEL MOISTURE AROUND 800MB AND BELOW WILL
REMAIN TRAPPED UNDER THE LOWERING INVERSION THURSDAY-FRIDAY...AND
THE DGZ WILL BE WITHIN THIS MOISTURE LAYER...NO HEADLINE LES IS
ANTICIPATED. THIS WILL BE EVEN THROUGH SLR VALUES CLIMB BACK TO 20-
25:1. LESS THAN FAVORABLE W-SW WINDS FRIDAY EVENING SHOULD PUSH MUCH
IF NOT ALL OF THE LINGERING LIGHT SNOW SHOWERS BACK INTO LAKE
SUPERIOR. THE DRY WEATHER WILL ONLY BE TEMPORARY.
REST OF SATURDAY... A BRIEF TROUGH OF LOW PRESSURE WILL PUSH ACROSS
LAKE SUPERIOR ON SATURDAY...BEFORE STRONGER HIGH PRESSURE NEARS FROM
CENTRAL CANADA. TIMING THIS TROUGH IS IS STILL A BIT ROUGH...AS THE
GFS/ECMWF/CANADIAN DIFFER BY 6-12HRS. THE 27/00Z CANDIAN AND 26/12Z
ECMWF ARE PRETTY CONSISTANT...WHILE THE 27/00Z GFS IS ON THE SLOW
SIDE. EITHER WAY IT WILL USHER IN ANOTHER ROUND OF COLD AIR. HIGHS
SUNDAY SHOULD TOP OUT 10-17F.
SUNDAY THROUGH MONDAY... STRONGER AND COLD 30.9 INCH/1040-1050MB
HIGH PRESSURE OVER MUCH OF CENTRAL CANADA FRIDAY AND SATURDAY WILL
SLOWLY WEAKEN TO 30.6IN/1033-1037MB AS IT SETTLES ACROSS THE N
PLAINS/ UPPER MS VALLEY/UPPER GREAT LAKES TO START THE NEXT WORK
WEEK. HIGHS MONDAY MAY ONLY BE IN THE SINGLE DIGITS ABOVE ZERO.
THE HIGH WILL CONTINUE TO SINK SE ACROSS THE MID MS VALLEY/OHIO
VALLEY MONDAY NIGHT...AND MID ATLANTIC STATES TUESDAY-WEDNESDAY. THE
GFS IS PERSISTENT IN KEEPING THE HIGH IN PLACE...WHILE THE 26/12Z
ECMWF IS MORE PROGRESSIVE. MORE ON THIS WHEN WE START FCSTING FOR
MID NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 625 AM EST TUE JAN 27 2015
DRY AIR SLIPPING SLOWLY TO THE W IN THE LGT ESE FLOW ON THE WRN FLANK
OF HI PRES IN SE CANADA WL BRING PREDOMINANT VFR CONDITIONS TO CMX AND
SAW INTO THIS AFTN...WHEN A WSHFT TO THE SW ACCOMPANYING THE RDG MOVING
TO THE S WL DRAW MVFR CIGS PRESENT NEAR THE WI BORDER BACK OVHD. AS THE
SW WIND EVENTUALLY TAPS DRIER AIR TNGT AND THE INVRN BASE SINKS
FURTHER...THE LO CLDS/MVFR CIGS SHOULD GIVE WAY TO VFR CONDITIONS. FOR
IWD...MVFR CIGS SHOULD DOMINATE THRU THE DAY UNTIL LATE...WHEN LOWERING
INVRN BASE AND STRENGTHENING SW DOWNSLOPE WIND THAT WL ALSO TAP SOME
DRIER AIR WL BRING VFR CONDITIONS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 409 AM EST TUE JAN 27 2015
EXPECT S TO SW WINDS UNDER 20 KTS TO DOMINATE THRU WED AS A HI PRES
RIDGE OVER UPPER MI TODAY SINKS SLOWLY INTO THE LOWER GREAT LAKES.
ON THE NORTHERN FLANK OF A HI PRES RIDGE ORIENTED ACROSS THE CENTRAL
GREAT LAKES. LO PRES WILL THEN TRACK FROM THE MID MISSISSIPPI VALLEY
WED NIGHT TO THE LOWER LAKES THU NIGHT. BEHIND THE LOW...N TO NW
WINDS WILL INCREASE TO 20-30KT AND THEN TO GALE FORCE LATE THU AND
THU NIGHT. SINCE THESE STRONG WINDS WILL DRAW MUCH COLDER ARCTIC AIR
INTO THE UPPER LAKES...HEAVY FREEZING SPRAY WILL DEVELOP OVER MUCH
OF THE LAKE AND CONTINUE INTO FRI...WHEN WINDS/WAVES WILL DIMINISH
WITH THE CLOSER APPROACH OF CANADIAN HI PRES. ANOTHER DISTURBANCE
AND COLD FRONT MAY SWING ACROSS THE UPPER LAKES ON SAT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
502 AM EST TUE JAN 27 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 409 AM EST TUE JAN 27 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NW FLOW ALOFT OVER
THE GREAT LKS BTWN HI AMPLITUDE RDG OVER THE ROCKIES AND DEEP TROF
OVER THE E SUPPORTING INTENSE WINTER STORM THAT IS IMPACTING NEW
ENGLAND. SHRTWV DIGGING SEWD WITHIN THIS NW FLOW/DEEPER CLDS THAT
CAUSED PERIOD OF SN LAST EVNG ARE NOW SE OF THE AREA...SO LINGERING
LIGHT SN OVER THE CENTRAL CWA IS DIMINISHING WITH THE APRCH OF
SHRTWV RDG AXIS/DNVA/DEEP LYR QVECTOR CNVGC AND DRIER MID LVL AIR
SHOWN ON THE 00Z INL/YPL RAOBS. THESE RAOBS SHOW SOME LLVL MSTR BLO
INVRN...SO PLENTY OF LO CLDS LINGER UPSTREAM OVER NRN MN/NW ONTARIO.
HOWEVER...WITH 00Z H85 TEMP ONLY -5C AT INL...THE INCOMING AIRMASS
IS NOT SUFFICIENTLY COLD TO SUPPORT LES. COLDER AND DRIER LLVL AIR
IS STILL PRESENT TOWARD THE E AND ARCTIC HI PRES IN QUEBEC...WITH
MOCLR SKIES REPORTED EARLY THIS MRNG AT NEWBERRY AND THE SAULT.
MAIN FCST CONCERNS FOR TODAY/TNGT WL BE CLD TRENDS/IMPACT ON TEMPS.
TODAY...UPR MI WL BE DOMINATED BY DNVA/DEEP LYR QVECTOR DVGC
ASSOCIATED WITH APRCHG SHRTWV RDG. SO AFTER ANY LINGERING LIGHT SN
ENDS EARLY THIS MRNG...THE DAY SHOULD BE DRY AS SFC RDG AXIS
EXTENDING WSW FM THE HI CENTER IN QUEBEC SHIFTS OVER THE CWA.
DESPITE THE MID LVL DRYING...LINGERING LLVL MSTR TRAPPED BLO
LOWERING/STRENGTHENING SUBSIDENCE INVRN WL LIKELY MAINTAIN GENERALLY
MOCLDY SKIES...IN LINE WITH UPSTREAM OBS. ONE EXCEPTION SHOULD BE
THE ERN CWA...WHERE LIGHT E WIND WL MAINTAIN THE LLVL DRY AIR AND
ALLOW FOR MOSUNNY SKIES. ANOTHER AREA THAT MAY SEE SOME CLRG IS NEAR
LK SUP OVER THE NW CWA WHERE THE LLVL SW FLOW ON THE NRN FLANK OF
THE SFC RDG AXIS WL DOWNSLOPE AND RESULT IN LOWERING THE INVRN BASE
FURTHER. GOING FCST HI TEMPS MAINLY IN THE 20S...COLDEST OVER THE
E AND WARMEST OVER THE W...LOOK TO BE IN GOOD SHAPE.
TNGT...A SHRTWV IS FCST TO TRACK THRU FAR NRN ONTARIO. ALTHOUGH
LINGERING SHRTWV RDG AXIS WL FORCE THIS DISTURBANCE TO PASS TOO FAR
TO THE N TO BRING PCPN TO ALL BUT FAR NRN LK SUP LATE...AN INCRSG
LLVL ACYC SW FLOW BTWN THE SFC RDG AXIS SLIDING OVER LOWER MI AND
FALLING MSLP IN ONTARIO ASSOCIATED WITH THE PASSING SHRTWV WL ADVECT
SOME DRIER AIR INTO THE CWA. THIS DRYING PLUS MORE LLVL SUBSIDENCE
ASSOCIATED WITH THE STRENGTHENING ACYC FLOW WL LIKELY BREAK UP THE
LO CLDS OVER MUCH OF THE CWA...ESPECIALLY OVER NW NEAR LK SUP WHERE
SW WINDS DOWNSLOPE. OVER THE E...THE SW FLOW OFF LK MI MIGHT DRAW
MORE LO CLDS INTO THAT AREA. DESPITE ANY CLRG OF THE LOWER CLDS...
STRONGER WINDS AND INCRSG MID/HI CLDS ON THE SRN FLANK OF THE
DISTURBANCE PASSING TO THE N WL LIMIT THE DIURNAL TEMP FALL. EXPECT
THE LOWEST MIN TEMPS OVER THE E...WHERE TEMPS WL FALL OFF QUICKLY IN
THE EVNG BEFORE THE WINDS HAVE A CHC TO PICK UP A BIT OR ANY
CLDS ROLL IN LATER.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 502 AM EST TUE JAN 27 2015
MUCH OF THIS PERIOD WILL BE IMPACTED BY THE STEADY 500MB LOW OVER E
AND E CANADA. FROM TIME TO TIME IT WILL BE EXTENDING A TROUGH ACROSS
MUCH OF THE E HALF OF THE U.S.
WARMEST DAY THIS PERIOD WILL BE WEDNESDAY...WITH HIGHS GENERALLY 30-
35F ON LIGHT S FLOW. A LOW OVER N HUDSON BAY AND AN ADDITIONAL LOW
ACROSS THE N/CENTRAL PLAINS WILL PUSH A TROUGH OVER LAKE SUPERIOR
WEDNESDAY NIGHT. THIS WILL BRING THE BEST CHANCE OF WIDESPREAD SNOW
THROUGH THE LONG TERM PERIOD. HAVE ADJUSTED THE HWO MESSAGE TO
INCLUDE MAINLY THE TIP OF THE KEWEENAW AND E OF A LINE FROM MQT TO
ESC FOR THE POTENTIAL FOR MODERATE SNOW AMOUNTS. EXACT AMOUNTS VARY
SIGNIFICANTLY DEPENDING ON WHAT MODEL IS USED. FOR EXAMPLE AT KSAW
FOR WEDNESDAY NIGHT BUFKIT IS INDICATING THE POTENTIAL FOR 1-2IN
/00Z AND 06Z MODEL RUNS/. THE GFS IS SHOWING CLOSER TO 4-6IN. TAKING
A LOOK AT THE PRECIP FIELDS...THE 27/00Z ECMWF ALIGNS BETTER WITH
THE NAM WHILE THE CANADIAN IS CLOSER TO THE GFS. WILL CONTINUE A
FCST OF 2-5IN FOR MUCH OF THE CWA FROM WED THROUGH THURSDAY...WITH
ONLY 1-2IN ALONG THE WI BORDER. ONLY LIMITED SNOW IS EXPECTED OVER
THE UPSLOPE N CENTRAL AND E LOCATIONS BAST WEDNESDAY NIGHT/THURSDAY
MORNING.
THE TROUGH WILL WEAKEN THURSDAY/THURSDAY NIGHT AS THE LOW ACROSS THE
PLAINS SHIFTS TO S LOWER MI...AND THE NEW ENGLAND STATES.
HOWEVER...INCREASED N-NNW WINDS THURSDAY AFTERNOON LOOK
REASONABLE...WITH A 30-40KT LLJ SET UP...EXPECT ABOVE 925MB. THIS
WILL BE AS UPPER MI BECOMES STUCK BETWEEN THE EXITING LOW PUSHING
TOWARDS THE LOWER GREAT LAKES AND STRONG HIGH PRESSURE NEARING FROM
THE W. LOOK FOR PATCHY BLOWING SNOW TO DEVELOP THURSDAY ALONG LAKE
SUPERIOR...REDUCING VIS.
FRIDAY INTO EARLY SATURDAY... EXPECT THE HIGH MENTIONED ABOVE OVER
SASKATCHEWAN ON THURSDAY TO SINK ACROSS MN AND W LAKE SUPERIOR
FRIDAY MORNING...AND INTO THE OHIO VALLEY AND MID ATLANTIC STATES
SATURDAY. COLD AIR WILL BE OVERHEAD...WITH HIGHS IN THE LOW TO MID
TEENS FRIDAY. WHILE LOW LEVEL MOISTURE AROUND 800MB AND BELOW WILL
REMAIN TRAPPED UNDER THE LOWERING INVERSION THURSDAY-FRIDAY...AND
THE DGZ WILL BE WITHIN THIS MOISTURE LAYER...NO HEADLINE LES IS
ANTICIPATED. THIS WILL BE EVEN THROUGH SLR VALUES CLIMB BACK TO 20-
25:1. LESS THAN FAVORABLE W-SW WINDS FRIDAY EVENING SHOULD PUSH MUCH
IF NOT ALL OF THE LINGERING LIGHT SNOW SHOWERS BACK INTO LAKE
SUPERIOR. THE DRY WEATHER WILL ONLY BE TEMPORARY.
REST OF SATURDAY... A BRIEF TROUGH OF LOW PRESSURE WILL PUSH ACROSS
LAKE SUPERIOR ON SATURDAY...BEFORE STRONGER HIGH PRESSURE NEARS FROM
CENTRAL CANADA. TIMING THIS TROUGH IS IS STILL A BIT ROUGH...AS THE
GFS/ECMWF/CANADIAN DIFFER BY 6-12HRS. THE 27/00Z CANDIAN AND 26/12Z
ECMWF ARE PRETTY CONSISTANT...WHILE THE 27/00Z GFS IS ON THE SLOW
SIDE. EITHER WAY IT WILL USHER IN ANOTHER ROUND OF COLD AIR. HIGHS
SUNDAY SHOULD TOP OUT 10-17F.
SUNDAY THROUGH MONDAY... STRONGER AND COLD 30.9 INCH/1040-1050MB
HIGH PRESSURE OVER MUCH OF CENTRAL CANADA FRIDAY AND SATURDAY WILL
SLOWLY WEAKEN TO 30.6IN/1033-1037MB AS IT SETTLES ACROSS THE N
PLAINS/ UPPER MS VALLEY/UPPER GREAT LAKES TO START THE NEXT WORK
WEEK. HIGHS MONDAY MAY ONLY BE IN THE SINGLE DIGITS ABOVE ZERO.
THE HIGH WILL CONTINUE TO SINK SE ACROSS THE MID MS VALLEY/OHIO
VALLEY MONDAY NIGHT...AND MID ATLANTIC STATES TUESDAY-WEDNESDAY. THE
GFS IS PERSISTENT IN KEEPING THE HIGH IN PLACE...WHILE THE 26/12Z
ECMWF IS MORE PROGRESSIVE. MORE ON THIS WHEN WE START FCSTING FOR
MID NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1223 AM EST TUE JAN 27 2015
LINGERING LOW-LEVEL MOISTURE WILL KEEP ALL TAF SITES AT IFR TO LOW
MVFR CONDITIONS OVERNIGHT. EXPECT SOME DIURNAL IMPROVEMENT TO
HIGHER END MVFR LATE TUE MORNING INTO THE AFTERNOON UNDER A LIGHT
SOUTHERLY FLOW. VFR CONDITIONS MAY BE POSSIBLE AT KIWD TUE EVENING
AS DRIER AIR WORKS IN FROM THE SOUTH.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 409 AM EST TUE JAN 27 2015
EXPECT S TO SW WINDS UNDER 20 KTS TO DOMINATE THRU WED AS A HI PRES
RIDGE OVER UPPER MI TODAY SINKS SLOWLY INTO THE LOWER GREAT LAKES.
ON THE NORTHERN FLANK OF A HI PRES RIDGE ORIENTED ACROSS THE CENTRAL
GREAT LAKES. LO PRES WILL THEN TRACK FROM THE MID MISSISSIPPI VALLEY
WED NIGHT TO THE LOWER LAKES THU NIGHT. BEHIND THE LOW...N TO NW
WINDS WILL INCREASE TO 20-30KT AND THEN TO GALE FORCE LATE THU AND
THU NIGHT. SINCE THESE STRONG WINDS WILL DRAW MUCH COLDER ARCTIC AIR
INTO THE UPPER LAKES...HEAVY FREEZING SPRAY WILL DEVELOP OVER MUCH
OF THE LAKE AND CONTINUE INTO FRI...WHEN WINDS/WAVES WILL DIMINISH
WITH THE CLOSER APPROACH OF CANADIAN HI PRES. ANOTHER DISTURBANCE
AND COLD FRONT MAY SWING ACROSS THE UPPER LAKES ON SAT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...VOSS
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
409 AM EST TUE JAN 27 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 409 AM EST TUE JAN 27 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NW FLOW ALOFT OVER
THE GREAT LKS BTWN HI AMPLITUDE RDG OVER THE ROCKIES AND DEEP TROF
OVER THE E SUPPORTING INTENSE WINTER STORM THAT IS IMPACTING NEW
ENGLAND. SHRTWV DIGGING SEWD WITHIN THIS NW FLOW/DEEPER CLDS THAT
CAUSED PERIOD OF SN LAST EVNG ARE NOW SE OF THE AREA...SO LINGERING
LIGHT SN OVER THE CENTRAL CWA IS DIMINISHING WITH THE APRCH OF
SHRTWV RDG AXIS/DNVA/DEEP LYR QVECTOR CNVGC AND DRIER MID LVL AIR
SHOWN ON THE 00Z INL/YPL RAOBS. THESE RAOBS SHOW SOME LLVL MSTR BLO
INVRN...SO PLENTY OF LO CLDS LINGER UPSTREAM OVER NRN MN/NW ONTARIO.
HOWEVER...WITH 00Z H85 TEMP ONLY -5C AT INL...THE INCOMING AIRMASS
IS NOT SUFFICIENTLY COLD TO SUPPORT LES. COLDER AND DRIER LLVL AIR
IS STILL PRESENT TOWARD THE E AND ARCTIC HI PRES IN QUEBEC...WITH
MOCLR SKIES REPORTED EARLY THIS MRNG AT NEWBERRY AND THE SAULT.
MAIN FCST CONCERNS FOR TODAY/TNGT WL BE CLD TRENDS/IMPACT ON TEMPS.
TODAY...UPR MI WL BE DOMINATED BY DNVA/DEEP LYR QVECTOR DVGC
ASSOCIATED WITH APRCHG SHRTWV RDG. SO AFTER ANY LINGERING LIGHT SN
ENDS EARLY THIS MRNG...THE DAY SHOULD BE DRY AS SFC RDG AXIS
EXTENDING WSW FM THE HI CENTER IN QUEBEC SHIFTS OVER THE CWA.
DESPITE THE MID LVL DRYING...LINGERING LLVL MSTR TRAPPED BLO
LOWERING/STRENGTHENING SUBSIDENCE INVRN WL LIKELY MAINTAIN GENERALLY
MOCLDY SKIES...IN LINE WITH UPSTREAM OBS. ONE EXCEPTION SHOULD BE
THE ERN CWA...WHERE LIGHT E WIND WL MAINTAIN THE LLVL DRY AIR AND
ALLOW FOR MOSUNNY SKIES. ANOTHER AREA THAT MAY SEE SOME CLRG IS NEAR
LK SUP OVER THE NW CWA WHERE THE LLVL SW FLOW ON THE NRN FLANK OF
THE SFC RDG AXIS WL DOWNSLOPE AND RESULT IN LOWERING THE INVRN BASE
FURTHER. GOING FCST HI TEMPS MAINLY IN THE 20S...COLDEST OVER THE
E AND WARMEST OVER THE W...LOOK TO BE IN GOOD SHAPE.
TNGT...A SHRTWV IS FCST TO TRACK THRU FAR NRN ONTARIO. ALTHOUGH
LINGERING SHRTWV RDG AXIS WL FORCE THIS DISTURBANCE TO PASS TOO FAR
TO THE N TO BRING PCPN TO ALL BUT FAR NRN LK SUP LATE...AN INCRSG
LLVL ACYC SW FLOW BTWN THE SFC RDG AXIS SLIDING OVER LOWER MI AND
FALLING MSLP IN ONTARIO ASSOCIATED WITH THE PASSING SHRTWV WL ADVECT
SOME DRIER AIR INTO THE CWA. THIS DRYING PLUS MORE LLVL SUBSIDENCE
ASSOCIATED WITH THE STRENGTHENING ACYC FLOW WL LIKELY BREAK UP THE
LO CLDS OVER MUCH OF THE CWA...ESPECIALLY OVER NW NEAR LK SUP WHERE
SW WINDS DOWNSLOPE. OVER THE E...THE SW FLOW OFF LK MI MIGHT DRAW
MORE LO CLDS INTO THAT AREA. DESPITE ANY CLRG OF THE LOWER CLDS...
STRONGER WINDS AND INCRSG MID/HI CLDS ON THE SRN FLANK OF THE
DISTURBANCE PASSING TO THE N WL LIMIT THE DIURNAL TEMP FALL. EXPECT
THE LOWEST MIN TEMPS OVER THE E...WHERE TEMPS WL FALL OFF QUICKLY IN
THE EVNG BEFORE THE WINDS HAVE A CHC TO PICK UP A BIT OR ANY
CLDS ROLL IN LATER.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 437 PM EST MON JAN 26 2015
THERE WILL BE MINOR FLUCTUATIONS IN THE UPPER RIDGE ALONG THE
WESTERN COAST OF NORTH AMERICA...BUT IT WILL LARGELY STAY IN PLACE
THROUGH THE LONG TERM FORECAST. THIS WILL LEAD TO NORTHWESTERLY
FLOW ALOFT OVER THE UPPER GREAT LAKES REGION AND SEND A SERIES OF
SHORTWAVES THROUGH THE AREA.
THE UPPER GREAT LAKES REGION WILL BE UNDER WEAK RIDGING WITHIN THE
NORTHWESTERLY FLOW ALOFT TO START THE PERIOD...WHILE THE SURFACE
RIDGE WILL BE SLIDING EAST OF THE AREA. EXPECT THERE TO BE SOME
LINGERING LOWER CLOUDS OVER THE CENTRAL PART OF THE CWA...WHILE
THERE WILL BE HIGH CLOUDS SPREADING OVER THE WESTERN CWA AHEAD OF
THE NEXT SYSTEM. THESE CLOUDS WILL KEEP TEMPS FROM FALLING TOO MUCH
IN THAT AREA...BUT OVER THE EAST...CLEARING IN THE EVENING WILL
ALLOW TEMPERATURES TO QUICKLY FALL INTO THE LOWER SINGLE DIGITS
ABOVE ZERO. DID TREND TOWARDS THE BETTER PERFORMING GEM MODELS OVER
THE EAST IN THOSE CLEAR SKY AND RADIATIONAL COOLING SITUATIONS.
FOCUS THEN TURNS TO THE INVERTED TROUGH PUSHING EAST TOWARDS THE
AREA ON WEDNESDAY (FROM A LOW MOVING OUT OF THE NORTHERN/CENTRAL
PLAINS) AND THREE SHORTWAVES THAT WILL COME TOGETHER OVER THE GREAT
LAKES REGION THROUGH THURSDAY. THE INITIAL AREA OF PRECIPITATION
SHOULD STAY WELL TO THE NORTH OF UPPER MICHIGAN ON WEDNESDAY (TIED
TO THE DEEPER MOISTURE AND BROAD WARM AIR ADVECTION OVER NORTHERN
LAKE SUPERIOR. BUT AS A SECOND SHORTWAVE SLIDES SOUTHEAST INTO THE
AREA FROM MANITOBA ON WEDNESDAY NIGHT...EXPECT THE PRECIPITATION
SWEEP SOUTH THROUGH THE AREA WITH THE 850-700MB TROUGH. SHOULD SEE
1-3 INCHES OF SNOW MOVE ACROSS THE AREA ON WEDNESDAY NIGHT...WITH
THE HIGHEST AMOUNTS OVER THE EAST. COLDER AIR IS DELAYED BEHIND THE
SYSTEM...SO DON/T EXPECT MUCH IN THE WAY OF LAKE ENHANCEMENT...BUT
DID FACTOR IN SOME TERRAIN ENHANCEMENT FOR THURSDAY. WITH THAT LACK
OF COLD AIR...THE CLOUD THERMAL PROFILE IS ON THE EDGE FOR ICE
CRYSTALS. AT THIS POINT...THINK THERE WILL BE ENOUGH AND LEFT OUT
FREEZING DRIZZLE...BUT IT WILL BE SOMETHING TO WATCH.
THE COLD AIR FINALLY ARRIVES ON THURSDAY NIGHT AND REMAINS INTO
FRIDAY UNDER NORTH-NORTHWEST WINDS ALOFT. EXPECT LIGHT LAKE EFFECT
TO OCCUR IN THOSE SNOW BELTS...BUT WITH SUBSIDENCE FROM HIGH
PRESSURE BUILDING INTO THE UPPER MISSISSIPPI VALLEY...INVERSION
HEIGHTS WILL STRUGGLE TO RISE MUCH ABOVE 4-5KFT. THUS...THINK
ACCUMULATIONS WILL BE ON THE LOW SIDE...BUT THEY WILL BE EFFICIENT
AT REDUCING VISIBILITIES DUE TO THE CLOUD BEING ABOVE THE DGZ.
WINDS WILL BACK ON FRIDAY AFTERNOON/NIGHT AS THE HIGH SLIDES JUST
TO THE SOUTH OF THE AREA.
FORECAST BECOMES A LITTLE UNCERTAIN AS MODELS DIVERGE ON THE UPPER
LEVEL FEATURES. ALL IN ALL...LOOKS LIKE A WEAK TROUGH WILL SLIDE
ACROSS THE AREA ON SATURDAY AND USHER IN ANOTHER SURGE OF COLD AIR
(MID -20S 850MB TEMPS) INTO THE UPPER GREAT LAKES REGION. WILL
CONTINUE TO SHOW LAKE EFFECT POPS BEHIND THAT TROUGH IN THE NW WIND
SNOW BELTS FOR SATURDAY NIGHT INTO MONDAY. WITH THE AMOUNT OF COLD
AIR...EXPECT LIMITED SNOWFALL AMOUNTS BUT GOOD VISIBILITY
RESTRICTION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1223 AM EST TUE JAN 27 2015
LINGERING LOW-LEVEL MOISTURE WILL KEEP ALL TAF SITES AT IFR TO LOW
MVFR CONDITIONS OVERNIGHT. EXPECT SOME DIURNAL IMPROVEMENT TO
HIGHER END MVFR LATE TUE MORNING INTO THE AFTERNOON UNDER A LIGHT
SOUTHERLY FLOW. VFR CONDITIONS MAY BE POSSIBLE AT KIWD TUE EVENING
AS DRIER AIR WORKS IN FROM THE SOUTH.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 409 AM EST TUE JAN 27 2015
EXPECT S TO SW WINDS UNDER 20 KTS TO DOMINATE THRU WED AS A HI PRES
RIDGE OVER UPPER MI TODAY SINKS SLOWLY INTO THE LOWER GREAT LAKES.
ON THE NORTHERN FLANK OF A HI PRES RIDGE ORIENTED ACROSS THE CENTRAL
GREAT LAKES. LO PRES WILL THEN TRACK FROM THE MID MISSISSIPPI VALLEY
WED NIGHT TO THE LOWER LAKES THU NIGHT. BEHIND THE LOW...N TO NW
WINDS WILL INCREASE TO 20-30KT AND THEN TO GALE FORCE LATE THU AND
THU NIGHT. SINCE THESE STRONG WINDS WILL DRAW MUCH COLDER ARCTIC AIR
INTO THE UPPER LAKES...HEAVY FREEZING SPRAY WILL DEVELOP OVER MUCH
OF THE LAKE AND CONTINUE INTO FRI...WHEN WINDS/WAVES WILL DIMINISH
WITH THE CLOSER APPROACH OF CANADIAN HI PRES. ANOTHER DISTURBANCE
AND COLD FRONT MAY SWING ACROSS THE UPPER LAKES ON SAT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...VOSS
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1223 AM EST TUE JAN 27 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 434 PM EST MON JAN 26 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW AN AMPLIFIED PATTERN OVER
NAMERICA...FEATURING A RIDGE OVER THE WRN CONUS INTO SW CANADA AND A
TROF OVER THE E. RESULTING NW FLOW INTO THE GREAT LAKES IS CARRYING
SEVERAL MINOR DISTURBANCES TO THE SE...AND THIS HAS LED TO BKN PCPN
EXTENDING FROM IL/IN NNW INTO NRN ONTARIO PER REGIONAL RADAR
IMAGERY. IR IMAGERY SHOWS ONE DIMINISHING AREA OF ENHANCED CLOUDS
NOW SSE OF UPPER MI AND A SECOND AREA DROPPING SSE TOWARD LAKE
SUPERIOR. THE ENHANCED CLOUDS WITH THE APPROACHING SHORTWAVE HAVE
NOT CHANGED MUCH OVER THE LAST SEVERAL HRS...AND ENVIRONMENT CANADA
RADAR NEAR THUNDER BAY SHOWS A DECENT AREA OF ASSOCIATED SNOW
APPROACHING NW LAKE SUPERIOR. TO THE SE...AN AREA OF ENHANCED
CONVERGENCE OVER LAKE MI AT THE LEADING EDGE OF STRONGER SE WINDS
LED TO SOME SNOW SPREADING OFF LAKE MI INTO DELTA AND ALGER COUNTIES
TODAY. ON VIS SATELLITE IMAGERY...HIGH CLOUDS HAVE THINNED JUST
ENOUGH TO SEE THAT THERE IS LITTLE IN THE WAY OF LAKE EFFECT CLOUDS
REMAINING ON NRN LAKE MI NOW.
SHORTWAVE OFF TO THE NW WILL DIVE SE ACROSS UPPER MI TONIGHT. GIVEN
THE ENHANCED CLOUDS JUST NNW OF THE AREA...SNOW DEPICTED ON UPSTREAM
RADAR IMAGERY NEAR THUNDER BAY AND MODEST DEEP LAYER QVECTOR
CONVERGENCE INDICATED BY MODELS...EXPECT ANOTHER AREA OF STEADIER
-SN TO SPREAD SSE ACROSS THE WRN AND CNTRL FCST AREA THIS EVENING.
ERN EDGE OF THE FORCING WILL BE UP AGAINST A STEADY FEED OF LOW-
LEVEL DRY AIR EMANATING FROM HIGH PRES CENTERED OVER SOUTHERN
QUEBEC. THIS IS CERTAINLY EVIDENT IN NAM/GFS/RUC13 FCST SOUNDINGS
WHICH MAINTAIN A DRY WEDGE IN ROUGHLY THE 2-5KFT LAYER...AND HIGH
RES MODELS SHOW PCPN STAYING W OF ROUGHLY A KISQ/SHINGLETON LINE
WITH ONLY THE GEM GETTING PCPN CLOSE TO KERY. THUS...WILL NOT
INCLUDE ANY SNOW IN THE FCST OVER THE FAR E TONIGHT. THAT SAID...THE
ONLY POTENTIAL ISSUE WOULD BE FOR A COUPLE OF THE LES BANDS OFF NRN
LAKE HURON TO STREAK WNW INTO LUCE COUNTY FOR A TIME TONIGHT. BACK
TO THE W...HIGH RES MODELS SHOW PCPN AMOUNTS IN THE 0.03 TO 0.1 INCH
RANGE TONIGHT...FALLING ALMOST ENTIRELY BEFORE 06Z. WITH SLR
PROBABLY AROUND 17 TO 1...THIS SUGGESTS SNOW AMOUNTS OF 0.5 TO
NEARLY 2 INCHES. WITH LOW-LEVEL SE WINDS PROVIDING
UPSLOPING/MOISTENING OFF LAKE MICHIGAN...THE HIGHER SNOW AMOUNTS
SHOULD OCCUR ROUGHLY IN THE AREA S OF A LINE FROM IRON RIVER TO
NEGAUNEE TO ESCANABA. AS FOR TEMPS...BIGGEST CHALLENGE IS OVER THE
FAR E WHERE CLOUDS MAY THIN OUT ENOUGH LATE IN THE NIGHT FOR TEMPS
TO PLUMMET UNDER LIGHT/CALM WIND. FOR NOW...INDICATED MINS NEAR
ZERO IN THAT AREA.
QUIET DAY ON THE WAY FOR TUE WITH SFC HIGH PRES RIDGE OVER UPPER MI.
WHILE THE E WILL PROBABLY ENJOY A MOSTLY SUNNY DAY...LOW CLOUDS WILL
LIKELY TAKE SOME TIME TO SCATTER OUT OVER THE W AND CNTRL. EXPECT
HIGHS RANGING FROM THE LWR 20S E TO THE UPPER 20S W.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 437 PM EST MON JAN 26 2015
THERE WILL BE MINOR FLUCTUATIONS IN THE UPPER RIDGE ALONG THE
WESTERN COAST OF NORTH AMERICA...BUT IT WILL LARGELY STAY IN PLACE
THROUGH THE LONG TERM FORECAST. THIS WILL LEAD TO NORTHWESTERLY
FLOW ALOFT OVER THE UPPER GREAT LAKES REGION AND SEND A SERIES OF
SHORTWAVES THROUGH THE AREA.
THE UPPER GREAT LAKES REGION WILL BE UNDER WEAK RIDGING WITHIN THE
NORTHWESTERLY FLOW ALOFT TO START THE PERIOD...WHILE THE SURFACE
RIDGE WILL BE SLIDING EAST OF THE AREA. EXPECT THERE TO BE SOME
LINGERING LOWER CLOUDS OVER THE CENTRAL PART OF THE CWA...WHILE
THERE WILL BE HIGH CLOUDS SPREADING OVER THE WESTERN CWA AHEAD OF
THE NEXT SYSTEM. THESE CLOUDS WILL KEEP TEMPS FROM FALLING TOO MUCH
IN THAT AREA...BUT OVER THE EAST...CLEARING IN THE EVENING WILL
ALLOW TEMPERATURES TO QUICKLY FALL INTO THE LOWER SINGLE DIGITS
ABOVE ZERO. DID TREND TOWARDS THE BETTER PERFORMING GEM MODELS OVER
THE EAST IN THOSE CLEAR SKY AND RADIATIONAL COOLING SITUATIONS.
FOCUS THEN TURNS TO THE INVERTED TROUGH PUSHING EAST TOWARDS THE
AREA ON WEDNESDAY (FROM A LOW MOVING OUT OF THE NORTHERN/CENTRAL
PLAINS) AND THREE SHORTWAVES THAT WILL COME TOGETHER OVER THE GREAT
LAKES REGION THROUGH THURSDAY. THE INITIAL AREA OF PRECIPITATION
SHOULD STAY WELL TO THE NORTH OF UPPER MICHIGAN ON WEDNESDAY (TIED
TO THE DEEPER MOISTURE AND BROAD WARM AIR ADVECTION OVER NORTHERN
LAKE SUPERIOR. BUT AS A SECOND SHORTWAVE SLIDES SOUTHEAST INTO THE
AREA FROM MANITOBA ON WEDNESDAY NIGHT...EXPECT THE PRECIPITATION
SWEEP SOUTH THROUGH THE AREA WITH THE 850-700MB TROUGH. SHOULD SEE
1-3 INCHES OF SNOW MOVE ACROSS THE AREA ON WEDNESDAY NIGHT...WITH
THE HIGHEST AMOUNTS OVER THE EAST. COLDER AIR IS DELAYED BEHIND THE
SYSTEM...SO DON/T EXPECT MUCH IN THE WAY OF LAKE ENHANCEMENT...BUT
DID FACTOR IN SOME TERRAIN ENHANCEMENT FOR THURSDAY. WITH THAT LACK
OF COLD AIR...THE CLOUD THERMAL PROFILE IS ON THE EDGE FOR ICE
CRYSTALS. AT THIS POINT...THINK THERE WILL BE ENOUGH AND LEFT OUT
FREEZING DRIZZLE...BUT IT WILL BE SOMETHING TO WATCH.
THE COLD AIR FINALLY ARRIVES ON THURSDAY NIGHT AND REMAINS INTO
FRIDAY UNDER NORTH-NORTHWEST WINDS ALOFT. EXPECT LIGHT LAKE EFFECT
TO OCCUR IN THOSE SNOW BELTS...BUT WITH SUBSIDENCE FROM HIGH
PRESSURE BUILDING INTO THE UPPER MISSISSIPPI VALLEY...INVERSION
HEIGHTS WILL STRUGGLE TO RISE MUCH ABOVE 4-5KFT. THUS...THINK
ACCUMULATIONS WILL BE ON THE LOW SIDE...BUT THEY WILL BE EFFICIENT
AT REDUCING VISIBILITIES DUE TO THE CLOUD BEING ABOVE THE DGZ.
WINDS WILL BACK ON FRIDAY AFTERNOON/NIGHT AS THE HIGH SLIDES JUST
TO THE SOUTH OF THE AREA.
FORECAST BECOMES A LITTLE UNCERTAIN AS MODELS DIVERGE ON THE UPPER
LEVEL FEATURES. ALL IN ALL...LOOKS LIKE A WEAK TROUGH WILL SLIDE
ACROSS THE AREA ON SATURDAY AND USHER IN ANOTHER SURGE OF COLD AIR
(MID -20S 850MB TEMPS) INTO THE UPPER GREAT LAKES REGION. WILL
CONTINUE TO SHOW LAKE EFFECT POPS BEHIND THAT TROUGH IN THE NW WIND
SNOW BELTS FOR SATURDAY NIGHT INTO MONDAY. WITH THE AMOUNT OF COLD
AIR...EXPECT LIMITED SNOWFALL AMOUNTS BUT GOOD VISIBILITY
RESTRICTION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1223 AM EST TUE JAN 27 2015
LINGERING LOW-LEVEL MOISTURE WILL KEEP ALL TAF SITES AT IFR TO LOW
MVFR CONDITIONS OVERNIGHT. EXPECT SOME DIURNAL IMPROVEMENT TO
HIGHER END MVFR LATE TUE MORNING INTO THE AFTERNOON UNDER A LIGHT
SOUTHERLY FLOW. VFR CONDITIONS MAY BE POSSIBLE AT KIWD TUE EVENING
AS DRIER AIR WORKS IN FROM THE SOUTH.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 434 PM EST MON JAN 26 2015
WITH WEAK LOW PRES OVER NE MN DROPPING SSE TONIGHT...STRONGER S
WINDS OF 20-30KT WILL CONTINUE OVER ERN LAKE SUEPRIOR THRU THIS
EVENING BEFORE DIMINISHING OVERNIGHT. WITH WEAKER PRES GRADIENT OVER
THE W...WINDS WILL BE UNDER 20KT. WINDS WILL THEN BE UNDER 20KT
ACROSS THE ENTIRE LAKE TUE/WED AS HIGH PRES RIDGE DRIFTS SSE FROM
THE UPPER LAKES. LOW PRES WILL THEN TRACK FROM THE MID MISSISSIPPI
VALLEY WED NIGHT TO THE LOWER LAKES THU NIGHT. BEHIND THE LOW...N TO
NW WINDS WILL INCREASE TO 20-30KT THU/THU NIGHT WITH GALES POSSIBLE
OVER THE E HALF OF THE LAKE. WINDS WILL THEN DIMINISH FRI AS HIGH
PRES PASSES ACROSS THE WRN GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...VOSS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
639 PM CST WED JAN 28 2015
.UPDATE...
ISSUED AT 555 PM CST WED JAN 28 2015
UPDATED TO INCLUDE 00Z AVIATION DISCUSSION BELOW.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 342 PM CST WED JAN 28 2015
AN ACTIVE SHORT TERM AHEAD AS A LOW PRESSURE SYSTEM OVER THE
EASTERN DAKOTAS SLIDES SOUTHEAST INTO NORTHERN IL BY THURSDAY
MORNING. LITTLE ICE IS INDICATED ALOFT OVER NORTHERN AND EASTERN
AREAS OF THE FA TONIGHT WITH DEEPENING LOW LEVEL SATURATION. IN
ADDITION...SOUTHERLY LOW LEVEL WINDS INCREASE RATHER DRAMATICALLY
EARLY TONIGHT ACROSS EASTERN IA ON NORTHWARD INTO WEST CENTRAL
WI...WITH A VEERING PROFILE THROUGH 800MB. THIS SHOULD ADD THE
TURBULENCE FACTOR TO ALLOW FREEZING DRIZZLE TO BECOME WIDESPREAD
ACROSS MUCH OF WEST CENTRAL WI FROM AROUND MID EVENING INTO EARLY
THURSDAY MORNING. THIS IS COLLABORATED BY RUNS TODAY OF THE
HOPWRF...HRRR AND RAP SHOWING SOME A FEW HUNDREDTHS OF QPF IN THE
AFOREMENTIONED AREAS. THEREFORE...ISSUED A FREEZING RAIN ADVISORY
FROM 9 PM THROUGH 3 AM FROM RICE LAKE AND LADYSMITH ON SOUTH
THROUGH MENOMONIE AND AUGUSTA. THE EVENING SHIFT WILL NEED TO KEEP
A CLOSE EYE FROM THE TWIN CITIES ON NORTHWARD WHERE CONFIDENCE ON
THE FREEZING DRIZZLE IS LOWER.
IN THE WAKE OF THE LOW PRESSURE SYSTEM...THE SURFACE PRESSURE
GRADIENT INCREASES SIGNIFICANTLY ACROSS EASTERN SD AND SW MN
AFTER MIDNIGHT (12 MILLIBARS). IN FACT...6 HOUR PRESSURE CHANGES
ARE NEAR 14 MILLIBARS TO OUR WEST. BUFKIT PROFILE DATA SHOWED TWO
THINGS. FIRST...THE NAM PROFILE HAD THE STRONGEST TOP OF THE
CHANNEL WINDS NEARING 50 KNOTS ACROSS THE MN RIVER VALLEY AROUND
09Z WHILE THE GFS PROFILE HAD 32 KNOT WINDS AT 200 FEET AT KFRM.
THE COMBINATION OF CAA AND A UNIDIRECTIONAL FLOW TO THE TOP OF THE
CHANNEL RESULTED IN A WIND ADVISORY BEING ISSUED ALONG AND SOUTH
OF A LINE FROM APPLETON TO ALBERT LEA FROM MIDNIGHT THROUGH 9 AM.
TEMPERATURES TONIGHT AND THURSDAY ARE INTERESTING. BECAUSE OF THE
LOW PRESSURE SYSTEM COMING INTO THE AREA TONIGHT...TEMPERATURES
WILL WARM A LITTLE THIS EVENING AND THEN DROP BACK TO A LITTLE
BELOW WHERE WE ARE NOW. THURSDAY`S HIGHS WILL BE EARLY IN THE MORNING
WITH READINGS FALLING INTO THE TEENS AND LOWER 20S BY THIS TIME
THURSDAY AFTERNOON.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 342 PM CST WED JAN 28 2015
BY TOMORROW EVENING...THE PRESSURE GRADIENT WILL BE WEAKENING AND
THOSE STRONG NORTHWESTERLY WINDS WILL START TO SLOWLY DECREASE. A
SURFACE HIGH WILL DRIFT SOUTHEAST THROUGH OUR AREA OVERNIGHT THROUGH
FRIDAY MORNING...WHICH WILL BE ONE OF THE COOLER MORNINGS WE`VE HAD
IN TWO+ WEEKS WITH LOWS RANGING FROM NEAR ZERO NEAR LADYSMITH...TO
ABOUT 10-15 ABOVE TOWARD REDWOOD FALLS. THE CORE OF THE COLD WILL
ESSENTIALLY MISS US TO THE EAST AS IT IS DRAGGED SOUTH BEHIND THE
SYSTEM IMPACTING OUT REGION TONIGHT.
ON FRIDAY...MODEST WARM AIR ADVECTION WILL ENSUE AND ALLOW
TEMPERATURES TO WARM TO VERY NEAR SEASONAL NORMALS. WITH THE COLDER
AIR IN PLACE TO THE EAST OF THE AREA...HIGHS WILL STRUGGLE TO REACH
20 IN WEST CENTRAL WI...BUT WARMER AIR THE FURTHER WEST YOU GO WILL
YIELD HIGHS IN THE MID 20S FOR EASTERN MN AND LOW 30S ACROSS FAR
SOUTHWESTERN MN.
THE MAIN CHANGE FROM THE PREVIOUS FORECAST WAS TO THE SATURDAY NIGHT
SYSTEM. BOTH THE GFS AND EC RUNS CAME IN WITH A STRONG SURFACE HIGH
PUSHING SOUTH FROM SASKATCHEWAN INTO THE UPPER MIDWEST AS THE
NORTHERN STREAM JET BUCKLES SOUTHWARD ALLOWING DRY ARCTIC AIR TO
ADVANCE FURTHER SOUTH THAN PREVIOUS RUNS INDICATED. THIS IS A GREAT
HINDRANCE TO THE POTENTIAL FOR SNOW FROM A SYSTEM DEVELOPING IN THE
SOUTHWESTERN CONUS. BUT...THERE IS POTENTIAL FOR LIGHT SNOW FROM A
NORTHERN STREAM SHORTWAVE SATURDAY NIGHT. THIS LINES UP WELL WITH AN
ENHANCED AREA OF PV ADVECTING SOUTHEAST AND IN CONJUNCTION WITH THE
LEFT EXIT REGION OF A 120KT JET STREAK. ANY SNOW THAT DOES FALL
THROUGH WILL BE VERY LIGHT WITH THE PRE-EXISTING LOW LEVEL DRY AIR.
IT LOOKS LIKE WE`LL BEGIN FEBRUARY WITH TEMPERATURES SLIGHTLY BELOW
NORMAL AFTER AN IMPRESSIVE WARM STRETCH FOR THE LAST 3 WEEKS OF
JANUARY. BOUTS OF ARCTIC AIR WILL DROP SOUTH THROUGH THE
NORTHERN/NORTHEASTERN GREAT LAKES...GIVING US MORE OF A GLANCING
BLOW. ANOTHER POSSIBLE CLIPPER SYSTEM COULD BRING ANOTHER SHOT OF
VERY LIGHT SNOW MONDAY NIGHT/TUESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 555 PM CST WED JAN 28 2015
LOW STRATUS/FG WILL REMAIN IN PLACE THRU ARND MIDNIGHT...WITH SOME
PASSING -FZDZ/-SHSN ALONG THE WAY AS A CDFNT PUSHES THRU THE AREA.
TAFS MOST SUSCEPTIBLE TO SEEING PRECIP WILL BE THE WI SITES...AND
POSSIBLY AS FAR W AS KMSP-KSTC. ANY SITE THAT DOES SEE PRECIP WILL
LIKELY DROP INTO IFR RANGE...IF NOT THERE ALREADY BY VIRTUE OF LOW
STRATUS. ONCE THE CDFNT MOVES THRU...WINDS WILL QUICKLY SWING ARND
TO NW AND ANY PRECIP WILL COME TO AND END. WIND SPEEDS WILL ALSO
INCRS WHICH WILL HELP SCOUR OUT ANY NEAR-GROUND MOISTURE...THUS
ALLEVIATING VSBY CONCERNS. HOWEVER...THE LOW STRATUS WILL REMAIN
THRU AT LEAST THE FIRST HALF OF THU THOUGH CIGS WILL SLOWLY RISE
FROM IFR INTO THE LOWER-HALF RANGE OF MVFR. BY LATE AFTN...ANY
LINGERING LOW STRATUS WILL SCATTER OUT...RESULTING IN VFR CONDS BY
LATE TMRW AFTN INTO TMRW EVE. THE TIGHT PRES GRADIENT INCOMING
BEHIND THE FROPA WILL RESULT IN STRONG WINDS FOR THE REST OF THE
OVERNIGHT THRU MUCH OF THE DAY TMRW. SUSTAINED SPEEDS WILL
INCREASE TO 15-25 KT WITH HIGHER GUSTS BEFORE SETTLING DOWN THU
EVE.
KMSP...ABLE TO INITIALIZE AS MVFR BUT CONDS ARE EXPECTED TO DROP
TO IFR BY 02Z THEN REMAIN THERE THRU CLOSE TO DAYBREAK. OCNL
PERIODS OF -FZDZ/-SHSN WILL DRIFT ACRS THE FIELD OVERNIGHT BUT NOT
LOOKING FOR ANYTHING HEAVY. COLD FROPA BY 06Z WILL ALLOW PRECIP TO
GRADUALLY CEASE AND STRONG NW WINDS TO DEVELOP. HOWEVER...CIGS ARE
NOT EXPECTED TO RISE ABOVE 1700FT THRU LATE MRNG AND MAY EVEN HOLD
ON LONGER THAN THE 14Z TIME CURRENTLY ADVERTISED. CONDS LIKELY TO
IMPROVE TO VFR BY LATE THU AFTN.
/OUTLOOK FOR KMSP/
FRI...VFR. WIND S 5 KT.
SAT...MAINLY VFR...CHC MVFR CIGS/-SN. WIND N 5-10 KT.
SUN...MAINLY VFR...CHC MVFR CIGS. WIND N 10 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM CST THURSDAY FOR
MNZ054-056-064-065-073>075-082>084-091>093.
WI...FREEZING RAIN ADVISORY FROM 9 PM THIS EVENING TO 3 AM CST
THURSDAY FOR WIZ015-016-025-027-028.
&&
$$
UPDATE...JPC
SHORT TERM...RAH
LONG TERM...SPD
AVIATION...JPC
AREA FORECAST DISCUSSION
NWS DULUTH MN
332 AM CST TUE JAN 27 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 331 AM CST TUE JAN 27 2015
HIGH PRESSURE WAS SETTLING OVER THE FORECAST AREA AT 08Z. PLENTY OF
LOW CLOUDS COVERED THE AREA TRAPPED UNDER THE LOW LEVEL INVERSION
FROM THE HIGH. THERE ARE A FEW HOLES THAT OPEN NEAR LAKE
SUPERIOR...BUT NOT ANTICIPATING ANY OF THEM MAKING IT INLAND. IF
THEY DO...THEY WILL FILL IN RATHER QUICKLY. THE HIGH WILL DRIFT
OVER THE CENTRAL GREAT LAKES BY 00Z WEDNESDAY RESULTING IN A SW FLOW
AFFECTING THE AREA. MODELS ARE TRYING TO CLEAR OUT THE CLOUD COVER
SOMEWHAT DURING THE DAY...BUT HAVE OPTED TO HANG ONTO THE CLOUD
COVER THROUGH THE DAY AS 1000-850MB RH REMAINS ABOVE 65 PERCENT.
MODEL DIFFERENCES BEGIN TO CREEP INTO THE FORECAST PROCESS TONIGHT.
BY 06Z...THE ECMWF IS BRINGING SOME LIGHT QPF FROM INL TO THE
ARROWHEAD. OTHER MODELS KEEP THE PRECIPITATION NORTH OF THE CANADIAN
BORDER. HOWEVER...THE HIRES NMM/ARW EAST AND WEST ARE HINTING AT
SOME LIGHT PRECIPITATION...BUT JUST OVER THE ARROWHEAD. WILL USE A
BLENDED APPROACH AND HAVE NO QPF PRIOR TO 06Z. AFTER 06Z...HAVE
INTRODUCED SOME POPS TO THE TIP OF THE ARROWHEAD. THIS IS WHEN SOME
WEAK FRONTOGENESIS IS FOUND FROM 700MB TO 850MB. PTYPE SHOULD BE ALL
SNOW AS SUGGESTED BY THERMAL PROFILES. SNOW AMOUNTS WILL ONLY BE
ABOUT A TRACE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 331 AM CST TUE JAN 27 2015
OUR NEXT WEATHER MAKER IS PROJECTED TO MOVE THROUGH THE AREA ON
WEDNESDAY AND WEDNESDAY NIGHT. THERE ARE STILL LOTS OF DIFFERENCES
IN THE MODELS...BUT THE CONSENSUS SEEMS TO POINT TO A PAIR OF
SHORTWAVES MOVING THROUGH THE WEST-NORTHWEST UPPER LEVEL FLOW. ONE
IN THE NORTHERN STREAM THAT TRACKS ACROSS THE US/CANADIAN BORDER TO
LAKE SUPERIOR...AND ANOTHER THAT TRACKS FROM COLORADO EAST TO
SOUTHERN ILLINOIS BY THURSDAY MORNING. THE BETTER DYNAMICS ARE
FOCUSED ALONG THESE CORRIDORS...DESPITE THE WAVES BEING PHASED
ENOUGH FOR A SINGLE 850MB LOW MOVING ACROSS THE PLAINS. THE SURFACE
LOW TRACKS FROM WESTERN SOUTH DAKOTA EAST ACROSS IOWA...BUT THE
MODELS HAVE LOTS OF DIFFERENCES HERE...WITH SOME PLACING MORE ENERGY
IN THE NORTHERN STREAM AND PLACING A LOW FARTHER NORTH IN ADDITION
TO THIS MORE SOUTHERLY ONE. EITHER WAY...THE BETTER DYNAMICS STAY
JUST NORTH OF THE AREA AND SKIM THE NORTHERN CWA WITH PRECIPITATION
WEDNESDAY AND WEDNESDAY NIGHT...MAINLY ASSOCIATED WITH THE NORTHERN
STREAM WAVE. STILL LOTS TO SORT OUT WITH THIS SYSTEM...BUT FOR NOW
HAVE KEPT POPS IN THE LIKELY CATEGORY WEDNESDAY NIGHT ACROSS THE
NORTH...WITH LOWER POPS TO THE SOUTH. MID LEVEL TEMPERATURES GET
WARM ONCE AGAIN WITH THIS SYSTEM...AND WE HAVE A VERY REAL THREAT OF
MIXED PRECIPITATION INCLUDING FREEZING RAIN WEDNESDAY AND WEDNESDAY
EVENING BEFORE THE LOW PASSES THE AREA AND STRONG COLD AIR ADVECTION
SWITCHES ALL TO SNOW. SNOWFALL AMOUNTS WITH THIS SYSTEM WILL NOT BE
VERY LARGE...BUT THE MIXED PRECIPITATION MAY CAUSE TRAVEL PROBLEMS.
A STRONG HIGH PRESSURE BUILDS INTO THE AREA FOR THURSDAY NIGHT AND
FRIDAY...BRINGING COLDER TEMPERATURES TO THE REGION. WE MAY BE
LOOKING AT SOME BELOW ZERO TEMPERATURES BY FRIDAY MORNING. ANOTHER
COLD FRONT BRINGS ANOTHER CHANCE OF SNOW TO THE AREA ON
SATURDAY...BEFORE ANOTHER SURGE OF COLD AIR MOVES INTO THE AREA.
SATURDAY NIGHT AND SUNDAY NIGHT WILL BE COLDER YET...WITH
TEMPERATURES IN THE NEGATIVE DOUBLE DIGITS BY MONDAY MORNING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1134 PM CST MON JAN 26 2015
MVFR WITH A FEW IFR CEILINGS COVERED THE NORTHLAND LATE THIS
EVENING...AND ARE EXPECTED TO CONTINUE FOR MOST AREAS INTO AT
LEAST TUESDAY MORNING. OBSERVATIONS AND RADAR INDICATE LITTLE
PRECIP LEFT ACROSS THE AREA AND WE EXPECT THAT THROUGH THE REST OF
THE PERIOD AS WELL.
THE MAIN CHALLENGE CONTINUES TO BE WHEN AND IF THESE LOW CLOUDS
WILL BECOME SCATTERED. THE LATEST NAM AND RAP GUIDANCE CONTINUES
TO PUSH OFF THE CHANGE FROM MVFR/IFR TO VFR. WE WILL DELAY THIS
FOR SEVERAL MORE HOURS WITH THE 06Z TAFS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 32 21 32 22 / 0 10 20 50
INL 32 24 31 14 / 0 10 50 60
BRD 34 25 34 23 / 0 10 10 40
HYR 32 20 33 24 / 0 0 10 50
ASX 33 21 34 25 / 10 0 20 50
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...GSF
LONG TERM...LE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
1134 PM CST MON JAN 26 2015
.UPDATE...
ISSUED AT 918 PM CST MON JAN 26 2015
WE DECREASED SNOW/FREEZING DRIZZLE MENTION TONIGHT OVER NORTHERN
AREAS...BUT HELD ONTO OVER PORTIONS OF NORTHERN WISCONSIN FOR A
FEW MORE HOURS. OBSERVATIONS AND RADAR WOULD SUGGEST THE PRECIP IS
SPOTTY.
WE ALSO INCREASED CLOUD COVER TONIGHT INTO TUESDAY MORNING. WE DO
NOT EXPECT MUCH CLEARING OUTSIDE OF SOME POCKETS.
UPDATE ISSUED AT 547 PM CST MON JAN 26 2015
WE MADE SOME ADJUSTMENTS TO POPS EARLY THIS EVENING TO MATCH
CURRENT RADAR TRENDS...MAINLY INCREASING THEM EARLY OVER NORTHERN
WISCONSIN.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 245 PM CST MON JAN 26 2015
PERSISTENT SNOW SHOWERS WITH OCCASIONAL FREEZING DRIZZLE ON THE BACK
EDGE OF THE PRECIPITATION THIS AFTERNOON AND EVENING IS THE MAIN
CONCERN IN THE SHORT TERM. ADDITIONAL SNOW ACCUMULATION WILL BE
MINIMAL TONIGHT...AND ANY DRIZZLE OR FREEZING DRIZZLE TODAY WILL
BECOME ALL SNOW OR FLURRIES BY MIDNIGHT. COULD ALSO SEE PATCHY FOG
AFTER MIDNIGHT TONIGHT.
CLIPPER SYSTEM IS EXITING TO THE SOUTH/SE THIS AFTERNOON WITH A
TRAILING UPPER TROUGH AND AREA OF STEEP LAPSE RATES ALOFT SLIDING
ACROSS WRN ONTARIO AND WEAK HIGH PRESSURE BUILDING IN ON THE BACK
SIDE. A NARROW CORRIDOR OF WARM AIR IN THE MID LEVELS IS PASSING
THROUGH N-CENTRAL MN THIS AFTERNOON AND EARLY EVENING...WHICH IS
ALLOWING FOR VERY LIGHT RAIN/DRIZZLE TO FORM AROUND THE BRAINERD
LAKES AREA...WHILE SNOW SHOWERS CONTINUE THROUGH THE ARROWHEAD AND
OVER N-CENTRAL WI. AREAS IN BETWEEN...ALONG THE HIGHWAY 53 AND
I-35 CORRIDORS COULD SEE A MIX OF SNOW...FREEZING DRIZZLE AND/OR
DRIZZLE THROUGH THIS EVENING. HOWEVER...AS THE NIGHT WEARS ON THE
THREAT FOR PRECIP WILL DECREASE.
THE AIR MASS WILL MODIFY LATE TONIGHT AND TUESDAY MORNING WITH RAPID
DRYING ALOFT...COOLING IN THE NEAR-SFC LAYER...AND WEAK WAA
OCCURRING IN THE MID LEVELS. AS THIS MODIFICATION OCCURS ANY LIQUID
PRECIP WILL BECOME FROZEN...WITH FREEZING DRIZZLE CHANGING OVER TO
FLURRIES. AS THE WARMER AIR ADVECTS IN FROM THE WEST TONIGHT A
WEAK LOW LEVEL INVERSION WILL SET UP AND ALLOW FOR THE POTENTIAL
OF PATCHY FOG ACROSS THE NORTHLAND.
HIGH PRESSURE WILL BUILD IN ACROSS THE UPPER MIDWEST DURING THE DAY
TUESDAY AND KEEP WEATHER CONDITIONS QUIET WITH VERY MILD
TEMPERATURES ONCE AGAIN FROM THE UPPER 20S TO MID 30S. A FEW PEAKS
OF SUN ARE POSSIBLE TUE AFTERNOON...BUT MORE CLOUDS THAN SUN IS THE
MOST LIKELY SCENARIO.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 245 PM CST MON JAN 26 2015
A COUPLE MORE CLIPPERS WILL MOVE THROUGH THE REGION THIS
WEEK...PROVIDING ADDITIONAL OPPORTUNITIES TO PICK UP LIGHT SNOW. THE
FIRST CLIPPER WILL COME WEDNESDAY...AND THE SECOND ONE LATE THIS
WEEK. THERE IS MUCH LESS CONFIDENCE ON THE TIMING/TRACK/STRENGTH OF
THE SECOND CLIPPER THAN THE FIRST CLIPPER.
A WEAK CLIPPER WILL MOVE OUT OF CANADA INTO THE NORTHERN HIGH PLAINS
LATE TUESDAY...AND MERGE WITH ANOTHER SURFACE LOW PRESSURE CENTER IN
THE NORTHERN/CENTRAL PLAINS TUESDAY NIGHT. THIS COMBINED LOW WILL
DEEPEN AS IT MOVES EAST THROUGH THE CENTRAL PLAINS TOWARDS SOUTHERN
LAKE MICHIGAN WEDNESDAY AND WEDNESDAY NIGHT. THE MODELS INDICATE
THERE WILL BE A WEST TO EAST ORIENTATED BAND OF SNOW THAT WILL
DEVELOP WELL NORTH OF THE LOW WEDNESDAY. THIS BAND WILL PRIMARILY BE
OVER SOUTHERN MANITOBA AND NW ONTARIO...BUT WILL GRADUALLY SAG SOUTH
INTO THE NORTHLAND WEDNESDAY INTO WEDNESDAY EVENING. THE MODELS SHOW
THIS WILL ALSO BE ASSOCIATED WITH A SHORTWAVE AND BROAD UPWARD
MOTION. MOST OF THE SNOW WITH THIS SYSTEM WILL OCCUR LATE WEDNESDAY
AND EARLY THURSDAY. THE NORTHLAND CAN EXPECT A DUSTING TO LESS THAN
AN INCH OF SNOW. THE FAR NORTHERN ARROWHEAD HAS THE BEST CHANCE OF
SEEING MORE THAN ONE INCH OF SNOW. THE ASSOCIATED COLD FRONT WILL
MOVE THROUGH THE REGION WEDNESDAY NIGHT AND EARLY THURSDAY.
COLD NW FLOW WILL DEVELOP THURSDAY IN THE WAKE OF THE COLD FRONT AND
PASSING LOW PRESSURE SYSTEM. THIS WILL BEGIN A COOLING TREND INTO
THE WEEKEND. HIGH PRESSURE WILL MOVE THROUGH THE NORTHERN PLAINS AND
UPPER MIDWEST THURSDAY NIGHT AND FRIDAY...PROVIDING A PERIOD OF
RELATIVELY QUIET BUT COLDER WEATHER.
THE MODELS ARE SHOWING ANOTHER CLIPPER AND COLD FRONT MOVING THROUGH
THE NORTHLAND SOMETIME LATE THIS WEEK. THE GFS HAS A MUCH SLOWER AND
STRONGER CLIPPER THAN THE ECMWF AND GEM. LEANED ON THE ECMWF AND GEM
FOR THE FORECAST...WHICH BRING THE CLIPPER AND ASSOCIATED LIGHT SNOW
THROUGH THE NORTHLAND LATE FRIDAY AND EARLY SATURDAY. THE GFS DOES
NOT BRING THE SNOW THROUGH UNTIL SATURDAY AFTERNOON AND SATURDAY
NIGHT. THE COLD FRONT WILL CONTINUE THE COOLING TREND INTO EARLY
NEXT WEEK. HIGH TEMPERATURES WILL LIKELY BE AT LEAST 10 DEGREES
BELOW NORMAL BY SUNDAY AND MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1134 PM CST MON JAN 26 2015
MVFR WITH A FEW IFR CEILINGS COVERED THE NORTHLAND LATE THIS
EVENING...AND ARE EXPECTED TO CONTINUE FOR MOST AREAS INTO AT
LEAST TUESDAY MORNING. OBSERVATIONS AND RADAR INDICATE LITTLE
PRECIP LEFT ACROSS THE AREA AND WE EXPECT THAT THROUGH THE REST OF
THE PERIOD AS WELL.
THE MAIN CHALLENGE CONTINUES TO BE WHEN AND IF THESE LOW CLOUDS
WILL BECOME SCATTERED. THE LATEST NAM AND RAP GUIDANCE CONTINUES
TO PUSH OFF THE CHANGE FROM MVFR/IFR TO VFR. WE WILL DELAY THIS
FOR SEVERAL MORE HOURS WITH THE 06Z TAFS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 21 32 21 32 / 20 0 10 20
INL 18 32 24 31 / 10 0 10 50
BRD 24 34 25 34 / 10 0 10 10
HYR 19 32 20 33 / 50 0 0 10
ASX 22 33 21 34 / 40 10 0 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...MELDE
SHORT TERM...BJT
LONG TERM...GROCHOCINSKI
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1040 PM CST MON JAN 26 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 343 PM CST MON JAN 26 2015
A SURFACE LOW ANALYZED BY THE RAP NEAR DULUTH THIS AFTERNOON WITH A
STALLED WARM FRONT THROUGH EXTREME WESTERN WI...JUST EAST OF THE MN
BORDER. TEMPERATURES WEST OF THE FRONT HAVE CLIMBED WELL INTO THE
40S ACROSS MOST OF THE REGION WITH DEW POINTS IN THE LOW TO MID 30S.
THIS CAUSES SOME CONCERN FOR FOG DEVELOPMENT OVERNIGHT AS A SURFACE
HIGH/RIDGE AXIS MOVES IN LATE TONIGHT AND WINDS GO NEARLY CALM. THE
TRICKY PART OF THE FORECAST IS HOW FAR WEST THE CLOUD COVER WILL
EXTEND TONIGHT. MODEL GUIDANCE IS QUITE SATURATED AT 925MB BUT CAN
EASILY IMPACTED BY SURFACE MOISTURE. AN INVERSION WILL DEVELOP
AFTER DARK AND COULD LOCK ANY LOW CLOUD COVER IN PLACE. CONFIDENCE
IS LOW IN CLOUD COVER ACROSS WESTERN MN.
IN WEST CENTRAL WISCONSIN...EAST OF THE FRONT...TEMPERATURES HAVE
HELD STEADY IN THE MID 20S WITH -FZDZ AND -SN BEING REPORTED THROUGH
MUCH OF THE DAY. VERY LIGHT AND SCATTER PRECIP WILL CONTINUE MOVING
THROUGH THIS AREA ALONG THE FRONTAL BOUNDARY FOR THE NEXT FEW HOURS.
OTHERWISE...COOLED TEMPS SLIGHTLY FOR TOMORROW ACROSS THE EAST GIVEN
LINGERING CLOUD COVER...AND THE FACT THE SOUTHERLY WINDS ON THE BACK
SIDE OF THE RIDGE DONT ARRIVE UNTIL LATE IN THE DAY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 343 PM CST MON JAN 26 2015
A COUPLE CHANCES FOR LIGHT PRECIPITATION EXIST IN THE EXTENDED
PERIOD OF THE FORECAST...WHILE THE COOLDOWN REMAINS ON TRACK FOR THE
WEEKEND AND INTO EARLY NEXT WEEK.
EARLY AFTERNOON WATERVAPOR IMAGERY TOGETHER WITH GFS 500MB HEIGHTS
AND WINDS SHOWED A BROAD AREA OF NORTHEAST FLOW ACROSS THE CENTRAL
CONUS SANDWICHED BETWEEN THE NEGATIVELY TILTED RIDGE ALONG THE
SPINE OF THE ROCKIES...AND MORE NOTABLY THE NEGATIVE TILTED UPPER
LEVEL TROUGH DRIVING THE POWERFUL NOREASTER OVER THE NEW ENGLAND
AREA. THIS NORTHWEST FLOW PATTERN WILL GENERALLY REMAIN IN PLACE
ACROSS THE UPPER MIDWEST...WITH PERIODIC SHORTWAVES BRINGING
REPEATED CHANCES FOR LIGHT PRECIP.
THE FIRST WILL ARRIVE WEDNESDAY NIGHT...AND THERMAL PROFILES SHOW
THE POTENTIAL FOR A WINTRY MIX OF LIGHT SNOW OR FREEZING DRIZZLE.
NOTE...WEDNEDAYS HIGH TEMPERATURE WILL DEPEND HEAVILY ON CLOUD
COVER...SO DID NOT WARM TEMPS SINCE MID/LOW LEVEL CLOUDS SHOULD KEEP
AFTERNOON HIGHS FROM WARMING OUT OF CONTROL DESPITE THE FAVORABLE
TIMING OF THE WARM AIR ALOFT.
HIGH PRESSURE WILL BUILD IN THURSDAY AND FRIDAY...WITH COLD AIR
ADVECTION LIMITING TEMPS TO NEAR 30 ON THURSDAY...AND 20S ON FRIDAY.
FRIDAY NIGHT ANOTHER SYSTEM WILL MOVE ACROSS THE REGION...BUT
STRENGTH AND TIMING REMAIN UNCERTAIN. THE GFS IS FASTER AND STRONGER
THAN THE ECMWF/GEM...BUT NEITHER SOLUTION PRODUCES SIGNIFICANT
PRECIP...WHICH WILL BE ALL SNOW...ACROSS THE REGION. COLD AIR WILL
FUNNEL IN FOR THE EARLY PART OF NEXT WEEK...AND TO ECHO THE THOUGHTS
OF THE PREVIOUS FORECASTER...IT APPEARS MONDAY WILL HAVE HIGHS IN
THE SINGLE DIGITS...WITH LOWS BELOW ZERO OVERNIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1035 PM CST MON JAN 26 2015
OUTSIDE OF KRWF...WE HAVE HIGH CONFIDENCE IN MVFR CONDITIONS
TONIGHT. SITES THAT ARE CURRENTLY 3000-3200FT...SHOULD SEE SLOW
LOWERING OVER THE NEXT FEW HOURS. VISIBILITY AND PRECIP IS NOT A
CONCERN THROUGH THE MORNING.
KMSP...
WHILE WE EXPECT CEILINGS TO BE BELOW 3000FT FOR THE MORNING
RUSH...WE HAVE MEDIUM TO HIGH CONFIDENCE THEY WILL REMAIN ABOVE
1700FT. SHOULD HAVE LITTLE IN THE WAY OF AVIATION WEATHER IMPACTS
TODAY. THE WINDS SHOULD BE VERY LIGHT AND OUT OF THE N-NE BY THE
MORNING RUSH.
/OUTLOOK FOR KMSP/
WED...VFR. CHC MVFR. WIND SE 10 KT.
THU...CHC MVFR/-SN. WIND NW 10-20 KT.
FRI...VFR. WIND VARIABLE 2-5 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...SPD
LONG TERM...JRB
AVIATION...CLF
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1043 PM MST MON JAN 26 2015
.AVIATION...
06Z TAF CYCLE
VFR CONDITIONS SHOULD BE MAINTAINED THROUGH THE NEXT 24 HOURS AT
ALL TERMINAL SITES. A VERY ISOLD SHRA OR HIGH MT SHSN WILL BE
POSSIBLE FROM THE CONTINENTAL DIVIDE TO THE AZ BORDER THROUGH 00Z
WEDNESDAY. VERY BRIEF MT OBSCURATIONS POSSIBLE ALONG THE DIVIDE.
CHANCES NOW SO SLIM FOR A SHOWER IN KGUP WILL NOT INCLUDE VCSH IN
TAF.
&&
.PREV DISCUSSION...901 PM MST MON JAN 26 2015...
.UPDATE...
UPPER LEVEL LOW ACROSS THE PACIFIC HAS RETROGRADED SO FAR WEST
THAT PRECIPITATION CHANCES FOR NM CONTINUE TO DWINDLE DESPITE ONE
LOBE OF ENERGY KICKING OUT ACROSS SOCAL. HRRR AGREES AND PRODUCES
LITTLE QPF ACROSS WESTERN NM AND NEW GUIDANCE FOR THE NAM SUGGEST
NONE. THUS HAVE RATCHETED DOWN POPS FOR TONIGHT...AND EVEN
THEN...THEY STILL MAY BE TOO HIGH. AMOUNTS LOOK TO BE LESS THAN A
TENTH OF AN INCH IF ANYONE DOES RECEIVE PRECIP. WITH THE SYSTEM SO
FAR WEST...THE EFFECTS SHOULD BE MINIMALIZED GOING INTO TOMORROW
AS WELL SO HAVE LOWERED POPS ONCE AGAIN FOR TUESDAY. HAVE ALSO
LOWERED OR REMOVED POPS FOR WEDNESDAY AND WEDNESDAY NIGHT AS WELL
AS ANY REMAINING EFFECTS FROM THIS STORM SYSTEM SHOULD LARGELY
REMAIN NORTH OF THE NM/CO BORDER AS IT ROUNDS THE RIDGE.
OTHERWISE...MINOR TWEAKS TO TONIGHTS TEMPS AND SKY COVER. UPDATES
ALREADY OUT.
34
&&
.PREV DISCUSSION...241 PM MST MON JAN 26 2015...
.SYNOPSIS...
A LARGE BUT SLOW MOVING STORM DRIFTING OUT OF THE EASTERN PACIFIC
COASTAL WATERS OF BAJA CALIFORNIA INTO THE GREAT BASIN THROUGH
TUESDAY WILL INTRODUCE SOME SHOWERS IN WESTERN NEW MEXICO THROUGH
TUESDAY. A MIDWEEK BREAK FROM WEATHER WILL COME TO AN END LATE
THURSDAY...AS THE NEXT TROPICAL PACIFIC OCEAN STORM DRIFTS INTO
THE DESERT SOUTHWEST. SLOW MOTION WILL PRODUCE LONGER PERIODS OF
RAIN AND HIGH COUNTRY SNOW THROUGH MUCH OF FRIDAY AND INTO THE
FOLLOWING WEEKEND. COLDER AIR SAGGING SOUTHWARD WILL MOVE SHOWER
COVERAGE TO SOUTHERN NEW MEXICO AS THE WEEKEND WINDS UP...WITH
SOUTHERN CLOUDS CONTRASTING WITH NORTHERN CLEARING AS THE WORK
WEEK GETS UNDERWAY IN THE FIRST DAYS OF FEBRUARY.
&&
.DISCUSSION...
CURRENTLY...RIDGE ALOFT EXTENDING FROM SOUTH TEXAS ACROSS NEW
MEXICO TO THE INLAND PACIFIC NORTHWEST RIGHT NOW...AS LARGE
PACIFIC STORM SYSTEM SITS OFF THE SOUTHERN CALIFORNIA COAST WELL
WEST OF NEW MEXICO...AND SPEEDY POLAR JET STREAM FROM WESTERN CANADA TO
THE GULF OF MEXICO COAST PROVIDING THE FEATURE TO THE EAST OF NEW
MEXICO. BROAD SURFACE DOME OF HIGH PRESSURE OVER NEW MEXICO WILL
REMAIN IN PLACE FOR RIGHT NOW.
MODELS...IN GOOD AGREEMENT THROUGH NEXT WEEKEND...AND A START ON
MONDAY. DIFFERENCES EMERGING LATE MONDAY ONWARD...AS EUROPEAN
COLLEAGUES AT ECMWF MOVE THEIR SYSTEM EASTWARD WITH
AUTHORITY...WHILE DOMESTIC GFS COLLEAGUES ARE MUCH SLOWER WITH
EASTWARD DRIFT OF SYSTEM ACROSS THE SOUTHWESTERN U.S. THROUGH
MIDWEEK OF THE FOLLOWING WEEK. GOOD START CONVERTS PACIFIC SYSTEM
CORE INTO A WAVE AND SHEARS THE WAVE ACROSS SOUTHERN CALIFORNIA
TONIGHT...AND ON INTO THE CENTRAL ROCKIES BY TUESDAY NIGHT. FLOW
OVER NEW MEXICO WILL SIMPLY VEER FROM SOUTHERLY TO WESTERLY BY
MIDWEEK...AS QUICK DISTURBANCE MOVING ACROSS THE CENTRAL ROCKIES
MIGHT TAG THE NORTHERN TIER OF NEW MEXICO ON WEDNESDAY NIGHT.
UPSTREAM...NEXT TROPICAL PACIFIC SYSTEM WILL DEEPEN OFF SOUTHERN
CALIFORNIA AND WESTERN BAJA CALIFORNIA...AND THIS TROUGH WILL
DRIFT AGONIZINGLY SLOWLY TO SOUTHERN CALIFORNIA THURSDAY
NIGHT...TO THE COLORADO VALLEY IN WESTERN ARIZONA FRIDAY...AND
THEN A WOBBLE INTO NORTHERN SONORA ON SATURDAY. STORM WILL PICK UP
STRONG POSITIVE TILT ON SUNDAY...WITH CORE REMAINING OVER
NORTHWESTERN MEXICO...AND THIS WILL CLOSE UP INTO A LOW OVER THE
SOUTHERN PORTIONS OF BAJA CALIFORNIA NEAR CABO SAN LUCAS AND LA
PAZ TO KICK OFF THE WORK WEEK. DIFFERENCES EMERGING INTO
TUESDAY...AS EUROPEAN SYSTEM WILL PICK UP EASTBOUND SPEED...REACH
TEXAS BY TUESDAY AND DROP STRONGER NORTHWEST FLOW INTO NEW MEXICO
BY WEDNESDAY. DOMESTIC GFS...ON THE OTHER HAND...WILL KEEP SYSTEM
POSITIVELY TILTED BUT MUCH SLOWER...WITH CORE OVER EASTERN NEW
MEXICO ON WEDNESDAY AND MUCH WEAKER NORTHWEST FLOW ALOFT OVER THE
REMAINDER OF THE STATE. DIFFERENCES FROM MONDAY NIGHT ONWARD ARE
SOMEWHAT MODEST...SO CAN SIMPLY SPLIT THE DIFFERENCE FOR NOW AND
KEEP AN EYE ON FUTURE RUNS FOR ANY NEEDED IMPROVEMENT ON RUN TO
RUN CONTINUITY FOR ONE VERSION OR THE OTHER.
OVERNIGHT...MILDER OVERNIGHT YET AGAIN...AS CLOUD COVER AND SOME
SHOWER COVERAGE WORKS NORTH ACROSS CATRON COUNTY AND ON TOWARD
INTERSTATE 40 FROM THE ARIZONA LINE TO THE CONTINENTAL DIVIDE.
MOST SPOTS WILL PICK UP ISOLATED TO SCATTERED RAIN SHOWERS...WITH
SOME OVERNIGHT CHANGE OVER TO SNOW OVER THE CHUSKA MOUNTAINS AND
SUMMITS SLOPES OF THE CONTINENTAL DIVIDE BY EARLY TUESDAY
MORNING. SNOW ACCUMULATION NOT EXPECTED TO BE MUCH IN THESE HIGHER
SPOTS. RIDGE AXIS WILL DRIFT EAST OVERNIGHT...AND END UP LYING FROM
TEXAS INTO THE NORTHERN ROCKIES ON THE EAST SIDE OF NEW MEXICO BY
TUESDAY MORNING. OVERNIGHT WINDS WILL RUN ON THE LIGHT SIDE.
FOR TUESDAY...FLOW OVER NEW MEXICO GOING FROM ZERO UNDER THE RIDGE
TO SOMEWHAT STAGNANT SOUTHWEST FLOW BY TUESDAY AFTERNOON...AS
NORTH BOUND TROUGH CLIPS THE FOUR CORNERS AND SHEARS OFF INTO
WESTERN COLORADO. SURFACE TROUGH FROM WEST KANSAS TO THE TEXAS
PANHANDLE WILL RETURN WEST TO SOUTHWEST FLOW ACROSS THE SURFACES
IN THE EAST...WITH SOME BREEZES GOING THROUGH THE SANGRE DE CRISTO
MOUNTAINS IN THE NORTH...AND ALONG INTERSTATE 40 IN THE EASTERN
SLOPES AND ADJACENT PLAINS OF THE CENTRAL MOUNTAIN CHAIN THROUGH
TUESDAY AFTERNOON. LAST OF THE WESTERN ISOLATED SHOWER COVERAGE
WITH HIGH COUNTRY SNOWFALL WILL MIGRATE TO THE NORTHERN TIER
TUESDAY NIGHT AS SURFACE TEMPERATURES REMAIN 8 TO 15 DEGREES ABOVE
LATE JANUARY NORMALS. SNOW ACCUMULATION WILL RUN ON THE LOW
SIDE...AND FOCUS ON THE SAN JUAN AND NORTHERN SANGRE DE CRISTO
SUMMITS...AND SOME CHANCE FOR A LITTLE SNOW OVER THE JEMEZ SUMMITS
BEFORE STORMS MOVE NORTH TUESDAY EVENING.
FOR WEDNESDAY...FLOW ALOFT PICKING UP SPEED AND VEERING FROM
SOUTHWEST TO WEST...AS QUICK SHORTWAVE MAKES QUICK TRIP EASTWARD
ACROSS SOUTHERN COLORADO THROUGH WEDNESDAY AFTERNOON. SURFACE LOW
DEEPENING OVER THE MISSOURI RIVER VALLEY AS HIGH PRESSURE SETS UP
OVER THE GREAT BASIN TO THE WEST WILL SUPPORT SOME NORTHWEST
BREEZES ACROSS NEW MEXICO...WITH BREEZY SPEEDS OVER THE SANGRE DE
CRISTO AND CENTRAL MOUNTAIN CHAIN SUMMITS...AND SETTING UP EASTERN
SLOPES AND ADJACENT PLAINS NORTHWEST BREEZES OVER THE INTERSTATE
40 CORRIDOR IN THE EAST. LAST OF THE ISOLATE SHOWER COVERAGE WILL
FLICKER OVER THE NORTHERN TIER NEAR THE COLORADO LINE THROUGH
WEDNESDAY NIGHT. MIDWEEK DAYTIME TEMPERATURES RUNNING
STEADY...WITH 8 TO 15 DEGREE WARM DEPARTURES ON TAP...WARMEST IN
THE EAST.
FOR THURSDAY...COLD FRONT OUT OF THE CENTRAL PLAINS STATES WILL
INVADE EASTERN NEW MEXICO DURING THE DAY...AND EXPAND RAPIDLY WEST
AND SOUTH TO THE CONTINENTAL DIVIDE BY LATE THURSDAY AFTERNOON
INTO THURSDAY NIGHT. ACTION WILL BRING TEMPERATURES OUT OF THE
WARMTH AND INTO CLIMATOLOGICAL CLOSENESS TO NORMAL FOR LATE
JANUARY...A FEW DEGREES COOL IN THE EAST. DAYTIME SHOWERS OVER THE
NORTHERN MOUNTAINS...AND BUILDING THE NEXT ROUND INTO THE SOUTHWEST
AND SOUTH CENTRAL MOUNTAINS...WILL BECOME BROAD AND WIDESPREAD
RAIN AND SNOW THURSDAY NIGHT AS THE SOUTHWEST BOUND COLD FRONT
COLLIDES RAPIDLY WITH EASTBOUND TROPICAL STORM SYSTEM WORKING INTO
NEW MEXICO. BREEZY EAST TO SOUTHEAST WINDS WILL SET UP OVER THE
SOUTHERN HALF OF THE STATE NEAR THE FRONT AND UNDER THE BEST
DYNAMICS OVERHEAD...AND THIS COULD SET UP SOME EASTERLY BREEZES
THROUGH THE CENTRAL MOUNTAIN CHAIN AND OUT OVER THE RIO GRANDE
VALLEY THROUGH THURSDAY AFTERNOON WITH THESE BREEZES CONTINUING
THROUGH THURSDAY NIGHT.
OUTLOOK...FRIDAY THROUGH THE WEEKEND...BIG COOL DOWN WILL PUSH
TEMPERATURES INTO DOUBLE DIGITS BELOW NORMAL BY SUNDAY...A TAD
LESS EXTREME IN THE WEST. STORM CORE OVER NEW MEXICO FRIDAY WILL
GRADUALLY WEAKEN COLD FRONT ON SATURDAY AS STORM REMAINS IN
PLACE AND CONTINUES TO KEEP WEATHER UNSETTLED...AND THEN AS NEXT
RAPIDLY SINKING COLD FRONT REINVIGORATES OVER EXTREME SOUTHERN NEW
MEXICO...STORM FOCUS WILL SHIFT TO THE SOUTHERN HALF OF THE STATE
THROUGH SUNDAY. FRIDAY AND SATURDAY WILL REMAIN BREEZY OVER THE
SOUTH WITH CONTINUING EAST TO SOUTHEAST WINDS...WITH WIND SPEEDS
DROPPING OFF ON SUNDAY AS DIRECTIONS SHIFT TO MORE NORTHERLY.
SHY
&&
.FIRE WEATHER...
NO CRITICAL FIRE WX CONDITIONS EXPECTED FOR AT LEAST THE NEXT WEEK.
ALSO LOOKING AT AN INCREASING POTENTIAL FOR A WIDESPREAD WETTING
PRECIP EVENT BETWEEN THU NIGHT AND SAT NIGHT ACROSS THE ENTIRE FCST
AREA.
OVERALL QUIET PATTERN TO CONTINUE INTO THU MORN...WITH FEW
EXCEPTIONS. POOR VENT RATES WILL STILL REMAIN THE CASE INTO TUE
AS WINDS ALOFT TO BE FAIRLY LIGHT AND SFC PRESSURE GRADIENT PRETTY
WEAK. TEMPS TO CONTINUE WELL ABOVE SEASONAL AVERAGES INTO WED
AREA WIDE. AN UPPER LOW WEST OF THE NORTHERN BAJA REGION WILL HEAD
INTO CALIFORNIA LATE TONIGHT AND THE GREAT BASIN TUE...BUT WEAKEN
SOME AS IT DOES SO. WHILE MOISTURE IS COMING INTO NM CURRENTLY AND
WILL CONTINUE TO DO SO INTO TUE...IT WILL WILL BE MORE IN THE MID
AND UPPER LEVELS AND LESS SO DOWN LOW. FCST MODELS CONTINUE TO TREND
LOWER WITH AMT OF PRECIP TO BE SQUEEZED OUT TONIGHT THROUGH WED
ACROSS THE WEST AND NORTH WITH LITTLE INDICATION OF ANY AMTS INTO
THE WETTING CATEGORY OF A TENTH OF AN INCH OR MORE DURING THIS
PERIOD. EXPECTED MAINLY ISOLATED LIGHT RAIN SHOWERS AND HIGHER MTN
SNOW SHOWERS MAINLY NEAR AND WEST OF THE DIVIDE.
WINDS SFC AND ALOFT TO INCREASE SIGNIFICANTLY TUE NIGHT AND WED
MOSTLY ACROSS THE NORTHERN MTNS AND EAST FROM THE CENTRAL MTN
CHAIN...BUT MINIMUM RH VALUES TO BE TOO HIGH FOR ANY CRITICAL FIRE
WX CONDITIONS TO DEVELOP...THOUGH SOME WIND GUSTS BETWEEN 35 AND 45
MPH ARE POSSIBLE THESE AREAS. SOME MODEST VENTILATION RATE
IMPROVEMENTS EXPECTED...MAINLY FROM NW AND SANDIA/MANZANO MTS OVER
THE CENTRAL HIGHLANDS AND FAR NORTHEAST. MOST OTHER LOCATIONS WILL
CONTINUE TO SEE POOR TO MARGINALLY FAIR RATES WED. THEREAFTER A
BACKDOOR COLD FRONT WILL PUSH INTO NM...BRINGING SOME COOLING AND A
PERIOD OF MOISTENING EAST TO WEST LOW LEVEL WINDS. GUSTY EASTERLY
WINDS INTO THE RIO GRANDE VALLEY APPEAR LIKELY TO DEVELOP BY LATE
WED NIGHT OR THU MORN AND PERSIST THROUGH THU NIGHT AND PERHAPS FRI.
ANOTHER SURGE OF COOLER AIR AT THE SURFACE COULD OCCUR BY FRI NIGHT
OR SAT. NEITHER OF THESE SURGES SHOULD BE TERRIBLY COLD...BUT WILL
DROP TEMPS SLIGHTLY TO MODERATELY BELOW NORMAL. AS MENTIONED BRIEFLY
AT START OF THIS DISCUSSION WE ARE LOOKING AT INCREASING POTENTIAL
FOR WIDESPREAD WETTING PRECIP OVER MUCH OF NORTHERN AND CENTRAL NM
STARTING THU NIGHT AND CONTINUING THROUGH SAT BEFORE TAPERING OFF.
SNOW LEVELS MAY DROP SOME AS THIS EVENT GOES ON...BUT STILL LOOKS
LIKE THEY WILL BE RANGING FROM ABOUT 3500 TO ABOUT 5500 FEET EAST
AND GENERALLY BETWEEN 6000 AND A LITTLE OVER 7500 WEST. VENT RATES
IMPROVE THU...DUE TO STRONGER TRANSPORT WINDS...BUT WORSEN AGAIN
FRIDAY...AND AGAIN PERHAPS IMPROVING MAINLY EAST SAT.
43
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
346 PM EST TUE JAN 27 2015
.SYNOPSIS...
A STRONG COASTAL LOW PRESSURE EAST OF CAPE COD WILL
SLOWLY MOVE AWAY FROM THE REGION TONIGHT...WITH AREAS OF SNOW
TAPERING OFF TO SCATTERED FLURRIES BY WEDNESDAY MORNING. IN
ADDITION...GUSTY NORTH WINDS WILL SLOWLY DECREASE AS SURFACE HIGH
PRESSURE BUILDS INTO THE REGION. A FAST MOVING CLIPPER LIKE SYSTEM
WILL IMPACT THE NORTH COUNTRY LATE THURSDAY INTO FRIDAY WITH ANOTHER
ROUND OF LIGHT ACCUMULATING SNOW LIKELY. TEMPERATURES WILL START
BELOW NORMAL...BUT WARM TO NEAR NORMAL LEVELS BY THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 345 PM EST TUESDAY...AVE CANCELLED WINTER STORM WARNING AND
REPLACED WITH WINTER WX ADVISORY FOR SNOW AND BLOWING SNOW.
ALSO...EXPANDED ADVISORY TO COVER PARTS OF THE CHAMPLAIN AND
WESTERN SLOPES FOR THE COMBINATION SNOW AND BLOWING SNOW THROUGH
THE EVENING COMMUTE. EXPECTING A DIFFICULT EVENING COMMUTE ACROSS
MOST THE REGION. BTV PICKED UP 3 INCHES OF SNOW IN JUST SEVERAL
HRS UNDER THIS BAND OF HEAVY SNOW THIS AFTN. EXPECTING ADDITIONAL
ACCUMULATIONS OF 1 TO 3 WITH LOCALIZED HIGHER AMOUNTS UNDER THIS
NARROW MESO BAND OF MODERATE SNOW ACRS PORTIONS OF THE CHAMPLAIN
AND WESTERN SLOPES.
FCST CHALLENGE TONIGHT WL BE AREAL COVERAGE/INTENSITY OF SNOW THRU
MIDNIGHT...ESPECIALLY FOR THE CHAMPLAIN VALLEY AND PARTS OF GREEN
MTNS. CRNT WATER VAPOR SHOWS DEEP CLOSED CYCLONIC CIRCULATION JUST
EAST OF CAPE COD THIS AFTN...WITH SEVERAL BAND OF MID/UPPER LVL
MOISTURE ROTATING BACK TOWARD OUR CWA. WATER VAPOR AND RAP SHOWS
THIS MID LVL MOISTURE AND ELONGATED 5H VORTICITY MAXIMUM WL BECOME
STATIONARY ACRS THE CHAMPLAIN VALLEY/CENTRAL VT THIS
AFTN/EVENING...WITH OCCASIONAL SNOW LINGERING THRU THE EVENING HRS.
THIS SUPPORT ALOFT...COMBINED WITH FAVORABLE NORTHERLY FLW WL
ENHANCE CONVERGENCE ON THE EASTERN SIDE OF THE CHAMPLAIN
VALLEY...SUPPORTING LIGHT SNOW THRU 06Z...BEFORE TAPERING OFF TO
FLURRIES. IN ADDITION...NAM FROUDE NUMBER SHOWS BLOCKED FLW WITH
VALUES <0.50...SUPPORTING ENHANCED SNOWFALL ALONG AND UPSTREAM OF
THE GREEN MTNS INTO THE CHAMPLAIN VALLEY. WL TRY TO SHOW THIS DETAIL
IN THE GRIDS AND INCREASE THE SNOWFALL AMOUNTS SLIGHTLY ACRS THIS
REGION...THINKING BTWN 1 AND 4 INCHES...WITH ISOLATED HIGHER AMOUNTS
POSSIBLE. ELSEWHERE...AREAL COVERAGE OF MID LVL MOISTURE DECREASES
RAPIDLY THIS AFTN/EVENING...AND ADDITIONAL SNOWFALL WL BE LIMITED.
THIS IS ALREADY SUPPORTED BY RADAR SHOWING LARGE HOLE OF NO PRECIP
ACRS MOST OF THE CT RIVER VALLEY AND NEK OF VT. ADDITIONAL SNOWFALL
WL BE A DUSTING TO AN INCH OR TWO POSSIBLE IN THESE AREAS...WITH
ONLY FLURRIES FOR THE SAINT LAWRENCE VALLEY/WESTERN DACKS.
ALSO...EXPECT GUSTY NORTH WINDS TO CONTINUE...ESPECIALLY CHAMPLAIN
VALLEY WITH SOME ENHANCED CHANNELING...WHICH WL CAUSE AREAS OF
BLOWING AND DRIFTING SNOW. GUSTY TO 30 MPH WL BE LIKELY THRU 03Z
TONIGHT. TEMPS WL REMAIN NEARLY STEADY IN THE SINGLE DIGITS
ABOVE/BLW ZERO TO NEAR 10F MOST LOCATIONS.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
AS OF 345 PM EST TUESDAY...SFC HIGH PRES BUILDS ACRS OUR CWA ON
WEDS...RESULTING IN A SLOW WEST TO EAST CLRING TREND. GFS/ECMWF
STILL SHOWS SOME LINGERING 850 TO 500MB RH ACRS OUR CENTRAL/EASTERN
CWA THRU 15Z...BEFORE SHIFTING IT EASTWARD. LARGE SCALE SUBSIDENCE
AND DEEP DRYING WL RESULT IN CLRING SKIES BY 18Z WEDS. NEXT FAST
MOVING CLIPPER LIKE SYSTEM ARRIVES LATE THURS INTO FRIDAY. LATEST
GUIDANCE TRACKS THIS SYSTEM ACRS OUR CWA...WHICH WL CAUSE A
WIDESPREAD LIGHT SNOW EVENT. EXPECTING AN ADVISORY LVL EVENT WITH
GENERAL ACCUMULATIONS OF 3 TO 5 INCHES...EXCEPT SLIGHTLY HIGHER
AMOUNTS OF 6 INCHES IN THE FAVORABLE UPSLOPE REGIONS. TEMPS WL
REBOUND TO NEAR NORMAL LEVELS AFTER A COLD START ON THURS MORNING.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 335 PM EST TUESDAY...AN ACTIVE PATTERN IS QUITE LIKELY FOR
THE PERIOD, WITH TWO OPPORTUNITIES FOR SNOW AND SEVERAL DAYS WITH
WELL BELOW NORMAL TEMPERATURES. GIVEN THE ONGOING WEATHER, AND
FOCUS NEEDED ON THAT, I RELIED RATHER HEAVILY ON A "DOWN THE
MIDDLE" MODEL BLEND FOR MOST OF THE FORECAST PERIOD, WITH ONLY A
FEW MANUAL MODIFICATIONS. FROM WHAT I SAW, THE 12Z SUITE OF GFS,
GFS ENSEMBLE AND ECMWF WERE ALL IN THE BALLPARK ENOUGH THAT A
BLEND SHOULD WORK OUT PRETTY GOOD.
DAILY DETAILS BELOW...
FRIDAY: CLIPPER WILL BE QUICKLY EXITING DURING THE DAY, AND AS IT
MOVES EAST OF HERE IT SHOULD STRENGTHEN ONCE IT REACHES THE
"WARMER" ATLANTIC OCEAN WATERS. NET RESULT WILL BE AN INCREASE IN
NORTHWEST WINDS -- COULD BE GUSTY AT TIMES. PAINTED IN SOME
20-30MPH GUSTS. THESE NORTHWEST WINDS WILL ALSO USHER IN COLDER
AIR AS THE DAY GOES ON. DEFINITELY A NON-DIURNAL TEMPERATURE TREND
WITH HIGHS FIRST THING. THE MID 20S "WARMTH" AT 8AM WILL END UP
IN THE 5-15F RANGE BY EVENING TIME. COULD HAVE SOME WIND CHILL
ISSUES TO TRACK COME FRIDAY/FRIDAY NIGHT. ON THE PRECIPITATION
SIDE OF THINGS, SNOW SHOWERS FIRST THING IN THE DAY WILL DIMINISH
AND BE MORE CONFINED TO THE MOUNTAINS BY AFTERNOON. IN THE END,
LOOKS LIKE A SOLID 3-5" "ADVISORY" LEVEL EVENT (LOCALLY A BIT MORE
IN THE NORTHERN MOUNTAINS). GENERALLY CLEAR AND COLD FRIDAY
NIGHT. SUB- ZERO FOR EVERYBODY!
SATURDAY: HIGH PRESSURE BUILDS IN. SHOULD BE SUNNY, BUT ALWAYS
BEWARE OF SUNNY DAYS IN MID-WINTER. THAT MEANS COLD TOO. 925MB
TEMPERATURES DOWN AROUND -20C. HIGHS 0 TO 8F WHERE WE LIVE. BRRR.
WARM WEATHER FANS WILL NEED TO LOOK AT THE SUNNY SKIES AND PRETEND
TO FEEL THE WARMTH. SATURDAY NIGHT - ANOTHER QUIET AND COLD NIGHT.
SUB-ZERO FOR US ALL AGAIN.
SUNDAY/MONDAY: FAST MOVING TROUGH IN THE UPPER FLOW WILL RESULT IN
CYCLOGENESIS IN THE OHIO VALLEY SUNDAY, FOLLOWED BY PERHAPS THE
DEVELOPMENT BY MONDAY OF A STRONG SURFACE LOW THAT WILL TRACK
SOMEWHERE JUST SOUTH OF HERE. GFS SUGGEST JUST SOUTH OF LONG
ISLAND. ECMWF IS A BIT FARTHER NORTH AND GOES ACROSS SOUTHERN NEW
ENGLAND. HAVE GONE AHEAD AND BUMPED POPS UP TO THE 50-60% RANGE
FOR SUNDAY NITE/MONDAY. CERTAINLY STILL A LOT OF UNCERTAINTY WITH
REGARD TO TRACK AND INTENSITY. AT THIS POINT LOOKS LIKE AN ALL
SNOW EVENT WITH LIKELY A PLOWABLE AMOUNT OF SNOW. HOWEVER, IF THE
TRACK ENDS UP GOING A LITTLE FURTHER NORTH, THEN WE MAY BE LOOKING
AT SOME MIXED PRECIPITATION ISSUES FOR PARTS OF THE FORECAST AREA.
AS MENTIONED, EARLIER, JUST WENT WITH MODEL BLENDS FOR
TEMPERATURES BUT ABOVE THE BLENDS FOR PRECIPITATION CHANCES.
TUESDAY: ANOTHER SHOT OF BITTER ARCTIC AIR IN THE WAKE OF THE
SUNDAY/MONDAY STORM. GFS IS BRUTALLY COLD. 925MB TEMPERATURES DOWN
TO -35C! THE RAW MODEL SURFACE TEMPERATURE COME TUESDAY MORNING IS
-25 TO -35F! (NOTE THAT MOS TURNS THAT INTO A -3F FOR BTV), AND
HIGH TEMPERATURES WOULD ONLY BE -5 TO -15F. THE ECMWF IS "MUCH"
WARMER -- 925MB TEMPERATURES OF -20C WITH IT`S RAW SURFACE
TEMPERATURES ABOUT -15F IN THE MORNING WITH HIGHS -5 TO +5F. AT
THIS POINT, HAVE MADE THE FORECAST CLOSER TO THE ECWMF.
I DID WANT TO MAKE THE 7TH DAY OF THE FORECAST TO SHOW A +1C FOR A
HIGH TEMPERATURE, JUST TO GIVE SOME HOPE TO WARM WEATHER FANS
AFTER DAYS OF SUB-FREEZING (< 0C) HIGHS. BUT ALAS, IT WASN`T
POSSIBLE.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
THROUGH 18Z WEDNESDAY...CONFIDENCE ON THE LOW SIDE FOR SPECIFIC
DETAILS IN THE TAFS FOR NOW THROUGH 03Z. JUST WANTED TO GET THAT
OUT THERE FIRST.
CURRENTLY, CONDITIONS RANGE FROM IFR/LIFR ACROSS MUCH OF VERMONT
TO VFR ACROSS MUCH OF NORTHERN NEW YORK. BANDS OF SNOW ARE SLOWLY
PUSHING FROM EAST TO WEST ACROSS VERMONT. IN SPOTS, THE SNOW DOES
BRIEFLY RESULT IN VISIBILITY REDUCTIONS DOWN TO 1/4SM, BUT IN
GENERAL IT`S MORE LIKE 3/4SM TO 1 1/2SM.
RADAR TRENDS SHOWING THE INITIAL BATCH OF SNOW IS DRYING UP AS IT
MOVES TOWARD NORTHERN NEW YORK. THERE IS UNCERTAINTY AS TO WHETHER
IT MAKES IT TO SLK, THOUGH IT APPEARS MSS WILL STAY VFR. RADAR
ALSO SHOWING A "BREAK IN THE ACTION" DEVELOPING ACROSS THE VT/NH
BORDER. IT COULD BE THAT THIS IS A SIGN THAT THE SNOW WONT LAST
ALL THAT LONG (6 HOURS OR SO) IN ANY SPOT. HOWEVER, SOME GUIDANCE
SUGGESTS LIGHT SNOW CONTINUES ALL THE WAY TO 12Z.
GAVE IT MY BEST SHOT. IN GENERAL GOING WITH THE IDEA THAT THE BULK
OF THE MODERATE SNOW & LOWEST VISIBILITIES WILL LAST UP TO 20-23Z
OR SO, WITH DIMINSHING SNOW THROUGH 03Z (AND MVFR CONDITIONS).
AFTER THAT, VFR SHOULD BE THE RULE. MAY END UP NEEDING TO AMEND
FORECASTS IF THE RADAR TRENDS INDICATE THE FORECASTS NEED SOME
FIXING.
NORTHERLY SURFACE WINDS WILL REMAIN GUSTY, ESPECIALLY IN THE
CHAMPLAIN VALLEY. 20-25KTS SHOULD BE COMMON. PERHAPS SOME LOWER
30KT GUSTS. THESE WINDS WILL DIMINISH BY LATE AFTERNOON. THOUGH
NOT EXPLICITLY SHOWN IN THE TAFS, MINOR BLOWING SNOW MAY OCCUR AS
WELL.
FROM 12Z WEDNESDAY ONWARD, LOOKS LIKE VFR CONDITIONS AREA WIDE.
OUTLOOK 18Z WEDNESDAY THROUGH SUNDAY...
18Z WEDNESDAY THROUGH 00Z FRIDAY...VFR.
00Z FRIDAY THROUGH 00Z SATURDAY...MVFR/IFR IN PERIODS OF SNOW.
00Z SATURDAY ONWARD...VFR.
&&
.EQUIPMENT...
AS OF 122 PM EST MONDAY...THE KTYX 88D DOPPLER RADAR LOCATED NEAR
WATERTOWN NEW YORK WILL BE DOWN AT LEAST THROUGH TUESDAY. THIS IS
DUE TO A PEDESTAL DYNAMIC FAULT. ELECTRONICS TECHNICIANS HAVE
ORDERED NEW PARTS TO FIX THIS PROBLEM. HOWEVER...THE NEW PARTS
HAVE NOT ARRIVED AS OF THIS TIME AND THE KTYX RADAR WILL LIKELY
NOT BE RESTORED TO SERVICE UNTIL SOMETIME THIS WEEK.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER WEATHER ADVISORY UNTIL 1 AM EST WEDNESDAY FOR
VTZ002>012-016>019.
NY...WINTER WEATHER ADVISORY UNTIL 1 AM EST WEDNESDAY FOR NYZ035.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...NASH
AVIATION...NASH
EQUIPMENT...WFO BTV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1225 PM EST TUE JAN 27 2015
.SYNOPSIS...
STRONG COASTAL LOW PRESSURE WILL SPREAD WIDESPREAD LIGHT TO
MODERATE SNOWS ACROSS THE EASTERN HALF OF THE FORECAST AREA TODAY
INTO EARLY THIS EVENING. HIGH PRESSURE RETURNS FOR LATER TONIGHT
THROUGH EARLY THURSDAY WITH SEASONABLY COLD AND MAINLY DRY
WEATHER. MORE LIGHT SNOWS ARE EXPECTED BY THURSDAY NIGHT INTO
FRIDAY AS LOW PRESSURE TRACKS EAST FROM THE GREAT LAKES STATES.
&&
.NEAR TERM /UNTIL 10 PM THIS EVENING/...
AS OF 1214 PM EST TUESDAY...FCST REMAINS IN GOOD SHAPE THIS AFTN
WITH BAND OF MODERATE/HEAVY SNOW LIFTING ACRS CENTRAL VT
ATTM...WITH VIS AT MPV DOWN TO 1/4SM IN HEAVY SNOW. THIS BAND WL
SLOWLY SHIFT TWD THE CHAMPLAIN THRU THIS AFTN...WITH LIGHT TO
OCCASIONAL MODERATE SNOW EXPECT. CRNT RADAR SHOWS SNOW BREAKING UP
ACRS THE CT RIVER VALLEY...BUT EXPECT SOME ADDITIONAL LIGHT SNOW
THRU THE AFTN HOURS. HEADLINES REMAIN IN PLACE WITH STORM TOTAL
SNOW AMOUNTS RANGING FROM DUSTING TO 3 INCHES CHAMPLAIN
VALLEY/EASTERN DACKS TO 3 TO 6 INCHES CENTRAL VT...AND 5 TO 10
INCHES ACROSS RUTLAND/ORANGE AND WINDSOR COUNTIES. WL HAVE TO
WATCH POTENTIAL ENHANCEMENT HERE ACRS THE EASTERN CPV THRU THE
AFTN HOURS ASSOCIATED WITH NORTHERLY WINDS AND ADDITIONAL LLVL
MOISTURE COMING OFF LAKE CHAMPLAIN. LATEST RAP AND HRRR SHOW ONCE
THE MID/UPPER LVL BECOME SATURATED...THE SNOW MAY STICK AROUND
THRU 00Z THIS EVENING. ALSO...HAVE INCREASED WINDS ACRS THE
CHAMPLAIN VALLEY...AS WE ARE SEEING LOCALIZED ENHANCEMENT ON NORTH
FLW. COLCHESTER REEF SUBSTAIN AT 31 KNOTS AND DIAMOND ISLAND WAS
35 KNOTS EARLIER THIS MORNING. HAVE MENTION LOCALIZED GUSTS NEAR
THE LAKE AROUND 30 KNOTS OR SO.
&&
.SHORT TERM /10 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
AS OF 321 AM EST TUESDAY...HIGH PRESSURE THEN BUILDS EAST INTO
THE REGION BY WEDNESDAY WITH SKIES TRENDING CLEAR TO PARTLY CLOUDY
THROUGH THE COURSE OF THE AFTERNOON. DRY WEATHER CONDITIONS
EXPECTED WITH BLENDED MOS NUMBERS SUPPORTING HIGH TEMPERATURES
GENERALLY IN THE TEENS...PERHAPS LOWER 20S FAR SOUTH.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
AS OF 314 AM EST TUESDAY...DRY WEATHER TO START THE PERIOD AS
RIDGE OF HIGH PRESSURE AND ALOFT RESIDES OVER THE REGION WEDNESDAY
NIGHT. EARLY THURSDAY, THE RIDGE SLIDES EASTWARD WITH SOUTHERLY
FLOW DEVELOPING OVER THE REGION, INCREASING MOISTURE AND
MODERATING TEMPERATURES AHEAD OF A CLIPPER SYSTEM APPROACHING FROM
THE GREAT LAKES REGION. WHILE GFS AND ECMWF AGREE THAT
PRECIPITATION SHIELD WILL ENTER OUR WESTERN ZONES THURSDAY
AFTERNOON, THERE AREA DIFFERENCE REGARDING THE TRACK OF THE SFC
LOW AND THE PROGRESSION OF THE ASSOCIATED MID LEVEL TROUGH. THIS
LOW LOOKS TO BRING SNOW TO THE REGION THROUGH AT LEAST FRIDAY
EVENING. MID LEVEL TROUGH BECOMES NEGATIVELY TILTED ACCORDING TO
BOTH MODELS, THEREFORE AM FAVORING A SLOWER DEPARTURE OF
PRECIPITATION FROM NORTHEASTERN VERMONT AS DEPICTED BY THE ECMWF.
EXPECTING SOME LINGERING POPS INTO EARLY SATURDAY MORNING, BUT
NORTH/NORTHWEST FLOW BEHIND THIS SYSTEM WILL BRING IN DRIER AIR.
SO EXPECT SATURDAY TO BE MOSTLY DRY AT THIS POINT. AT THIS POINT,
EXPECT POTENTIAL SNOWFALL TOTALS TO RANGE FROM 2 TO 5 INCHES.
ANOTHER SYSTEM DEVELOPING IN THE MISSISSIPPI VALLEY WILL MOVE
NORTHEASTWARD LATE SUNDAY INTO MONDAY...BRINGING ANOTHER CHANCE
FOR SNOW FOR THE BEGINNING OF NEXT WEEK.
TEMPERATURES WEDNESDAY NIGHT WILL BE GENERALLY IN THE SINGLE
DIGITS ABOVE AND BELOW ZERO. TEMPERATURES MODERATING IN THE
SOUTHERLY FLOW THURSDAY THROUGH FRIDAY WITH MAXES IN THE 20S AND
MINS IN THE TEENS TO L20S. BEHIND THE CLIPPER LOW, COLD AIR WILL
RETURN WITH MINS OF -15F TO ZERO FOR THE REST OF THE PERIOD. MAXES
WILL REACH SINGLE DIGITS TO MID TEENS SATURDAY THROUGH MONDAY.
&&
.AVIATION /17Z TUESDAY THROUGH SUNDAY/...
THROUGH 12Z WEDNESDAY...VFR CONDITIONS WILL DETERIORATE TO MVFR
AS SNOW SPREADS NORTHWESTWARD THIS MORNING. EXPECT MVFR
CONDITIONS AND SNOW TO MOVE INTO KRUT BETWEEN 12-15Z...KMPV 13-
15Z...KBTV/KPBG 15Z-17Z...AND KSLK 16Z-18Z. KMSS WILL BE FAR
ENOUGH NORTH AND WEST TO REMAIN VFR. SOME EMBEDDED MODERATE SNOW
IS POSSIBLE WITH IFR/LIFR CONDITIONS AFFECTING KRUT/KMPV 14Z-
22Z...KBTV/KPBG 17Z-21Z AND KSLK 18Z-23Z.
SNOW WILL LIGHTEN AND DIMINISH THIS EVENING WITH MOSTLY DRY
CONDITIONS SETTLING IN AFTER MIDNIGHT/05Z. EXPECT CONDITIONS TO
IMPROVE TO MVFR/VFR AS SNOWFALL COMES TO AN END.
NORTH TO NORTHEAST WINDS OF 6-12KTS WILL INCREASE AND BECOME
GUSTY AROUND 25KTS BY MID MORNING. THIS WILL RESULT IN THE
POTENTIAL FOR AREAS OF BLOWING/DRIFTING SNOW, ESPECIALLY AT RUT
AND MPV WHERE DURATION OF MODERATE SNOW WILL BE LONGEST. EXPECT
GUSTS TO SUBSIDE HEADING INTO TUESDAY EVENING.
OUTLOOK 12Z WEDNESDAY THROUGH SATURDAY...
12Z WEDNESDAY THROUGH 12Z THURSDAY...MAINLY VFR CONDITIONS
EXPECTED AS RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION.
12Z THURSDAY THROUGH 00Z SATURDAY...TRENDING IFR/MVFR IN LIGHT
SNOW AS LOW PRESSURE MOVES EAST FROM THE OHIO VALLEY/GREAT LAKES
STATES.
00Z SATURDAY THROUGH 00Z SUNDAY...VFR CONDITIONS EXPECTING AS A
RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION.
&&
.EQUIPMENT...
AS OF 122 PM EST MONDAY...THE KTYX 88D DOPPLER RADAR LOCATED NEAR
WATERTOWN NEW YORK WILL BE DOWN AT LEAST THROUGH TUESDAY. THIS IS
DUE TO A PEDESTAL DYNAMIC FAULT. ELECTRONICS TECHNICIANS HAVE
ORDERED NEW PARTS TO FIX THIS PROBLEM. HOWEVER...THE NEW PARTS
HAVE NOT ARRIVED AS OF THIS TIME AND THE KTYX RADAR WILL LIKELY
NOT BE RESTORED TO SERVICE UNTIL SOMETIME THIS WEEK.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER STORM WARNING UNTIL 1 AM EST WEDNESDAY FOR VTZ010>012-
019.
WINTER WEATHER ADVISORY UNTIL 1 AM EST WEDNESDAY FOR VTZ004-
007>009-018.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...TABER
SHORT TERM...JMG
LONG TERM...KGM
AVIATION...KGM
EQUIPMENT...WFO BTV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
924 AM EST TUE JAN 27 2015
.SYNOPSIS...
STRONG COASTAL LOW PRESSURE WILL SPREAD WIDESPREAD LIGHT TO
MODERATE SNOWS ACROSS THE EASTERN HALF OF THE FORECAST AREA TODAY
INTO EARLY THIS EVENING. HIGH PRESSURE RETURNS FOR LATER TONIGHT
THROUGH EARLY THURSDAY WITH SEASONABLY COLD AND MAINLY DRY
WEATHER. MORE LIGHT SNOWS ARE EXPECTED BY THURSDAY NIGHT INTO
FRIDAY AS LOW PRESSURE TRACKS EAST FROM THE GREAT LAKES STATES.
&&
.NEAR TERM /UNTIL 10 PM THIS EVENING/...
AS OF 905 AM EST TUESDAY...FCST CHALLENGE CONTS TO BE NORTHERN
EXTENT OF HEAVIER SNOW SHIELD ASSOCIATED WITH STRONG COASTAL LOW
PRESSURE. OVERALL EXPECTING MINIMAL IMPACTS ACROSS OUR CWA...WITH
HEAVIEST SNOW ACCUMULATIONS OF 4 TO 8 INCHES OVER THE CT RIVER
VALLEY...WITH 3 TO 5 INCHES CENTRAL VT AND 1 TO 3 INCHES IN THE
CHAMPLAIN VALLEY AND A DUSTING TO AN INCH OR SO ACROSS NORTHERN
NY. ALL WARNINGS AND ADVISORIES WILL REMAIN UP FOR NOW...BUT WILL
RECONSIDER AFTER REVIEWING ALL 12Z DATA BEFORE DROPPING ANY HEADLINES.
CRNT SFC ANALYSIS SHOWS 977MB LOW PRES NEAR THE
40/70 BENCHMARK WITH BUOY 44008 INDICATING RISING
PRES...SUGGESTING LOW PRES WL TRACK JUST EAST OF THIS
LOCATION...WHICH IS ABOUT A 25 MILE SHIFT EASTWARD. THIS WL RESULT
IN LESS IMPACT OF HEAVIER SNOWFALL ACRS OUR CWA...WITH GREATEST
IMPACTS ACRS CENTRAL/EASTERN VT THRU THIS AFTN. HAVE NOTED VSF VIS
AT 1/2SM IN MODERATE SNOW AND MPV/RUT DOWN TO 1SM IN LIGHT SNOW.
EXPECT THIS ACTIVITY TO EXPAND NW INTO THE CHAMPLAIN VALLEY BY
NOON TODAY. LATEST 12Z RAP AND 12Z NAM DOES SHOW MID/UPPER LVL
CIRCULATION CAPTURING SFC FEATURE AND RETROGRADING IT BACK
WESTWARD...TWD THE CAPE. THIS WL HAVE TO BE WATCHED...AS CRNT
RADAR SHOWS VERY INTENSE MESO BAND OF HEAVY SNOW ACRS
CENTRAL/EASTERN NEW ENGLAND...MOVING TWD OUR EASTERN CWA. THIS
BAND IS EXPECTED TO WEAKEN AS IT SLOWLY MOVES WESTWARD...WHILE BEST
MOISTURE AND UPPER LVL SUPPORT IS CLOSER TO THE COAST...ASSOCIATED
WITH SFC LOW PRES. ALSO...WITH 977MB LOW PRES OFF THE SOUTHERN NEW
ENGLAND COAST...EXPECT GUSTY NORTH WINDS TO DEVELOP HERE IN THE
CHAMPLAIN VALLEY AND SAINT LAWRENCE VALLEY...WHERE ENHANCED
CHANNELING WILL OCCUR. HAVE MENTION GUST TO 30 MPH OR SO. REST OF
FCST IN GOOD SHAPE.
PRIOR DISCUSSION FROM 321 AM EST TUESDAY...
INTENSE STORM CONTINUES TO DEVELOP OFF THE SOUTHEASTERN NEW
ENGLAND COAST NEAR NANTUCKET EARLY THIS MORNING WITH IMPRESSIVE
3-HOURLY PRESSURE FALLS NEAR 8 MB JUST NORTH OF THE 40N/-70W
BENCHMARK PER MOST RECENT MSAS ANALYSIS. A CLASSIC MILLER-B
EVOLUTION WITH INTENSE FRONTOGENETICAL BANDING FEATURES PIVOTING
SLOWLY NORTH AND WEST ACROSS ERN MA/CT/LI. THE DEVIL IS IN THE
DETAILS HOWEVER...ESPECIALLY IN REGARD TO TOTAL QPF/SNOWFALL
ACROSS OUR AREA. LATEST CAM OUTPUT INCLUDING THE RAP AND HRRR ALL
COMING ON BOARD WITH FAIRLY REALISTIC SOLUTIONS SHOWING WESTERN
EDGE OF STEADIER SNOWS WILL SLOWLY PIVOT NORTH AND WEST INTO VT
THROUGH THE COURSE OF THE MORNING/EARLY AFTERNOON WITH A RATHER
SHARP CUTOFF IN PCPN THE FURTHER NORTH AND WEST ONE PROGRESSES.
MOST PROBLEMATIC IS THE VERY COLD AND DRY ARCTIC AIRMASS IN PLACE
ACROSS OUR AREA. INDEED...LOW TO MID LEVEL DEWPOINTS REMAIN QUITE
LOW THIS MORNING AND THIS WILL TAKE SEVERAL HOURS OF MOISTENING
BEFORE STEADIER SNOWS REACH THE CENTRAL/NRN PORTIONS OF THE STATE.
REMAINING DRY IN NRN NY UNTIL LATE MORNING/EARLY AFTERNOON AND
MAINLY EASTERN PORTIONS OF CLINTON/ESSEX COUNTIES.
OLD RULE OF THUMB THAT USUALLY WORKS WELL HERE IS NOT TO GO TOO
EXTREME ON SNOWFALL TOTALS IF SOUTH COASTAL NEW ENGLAND IS BEARING
THE BRUNT OF THE STORM. RARELY TO WE SEE HEAVY SNOW SWATHS IN
EXCESS OF 200 MI AND THIS STORM WILL BE NO EXCEPTION. PAST
HISTORY ALSO SUGGESTS CLIPPER BOMBS GENERALLY UNDERPERFORM UP HERE
IN LIEU OF THE MORE CLASSIC GULF COAST/SOUTHEASTERN SEABOARD
SYSTEMS AS LONGITUDINAL DEVELOPMENT TYPICALLY OCCURS A BIT TOO FAR
EAST FOR US. IN ANY REGARD FELT THIS MORNINGS NAM HAD THE BEST
HANDLE ON CURRENT SITUATION AND USED ITS SOLUTION IN TANDEM WITH
BLENDED CAM QPF OUTPUT TO ARRIVE AT POP/SNOWFALL GRADIENTS ACROSS
OUR AREA. GFS IDEA BIASED ABOUT 50 MI TOO FAR SOUTH AND EAST AND
EURO QPF TOO SPREAD OUT WITH ITS COARSER RESOLUTION DESPITE A
FAIRLY ACCURATE DEPICTION OF LOW TO MID LEVEL FEATURES.
WHAT THIS ALL SPELLS IS A STEADY 5-10/6-12 INCH SNOWFALL FOR OUR
SOUTHERNMOST COUNTIES...WITH A FAIRLY QUICK DROP OFF IN SNOW
TOTALS NORTH AND WEST. A SW-NE ORIENTED BAND OF 3-7 INCHES STILL
PROGGED FROM ABOUT MIDDLEBURY NORTHEASTWARD THROUGH MONTPELIER AND
ST JOHNSBURY...AND A GENERAL 1-3 INCH SNOWFALL FROM ESSEX COUNTY
NY NORTHEAST INTO THE BURLINGTON/PLATTSBURGH VICINITY AND ST
ALBANS/FRANKLIN COUNTY. LITTLE IF ANY ACCUMULATION FROM A SARANAC
LAKE TO MALONE LINE WEST. THIS IS MORE OR LESS STAYING THE COURSE
AND WE`RE NOW INTO THE WAIT AND SEE TIMEFRAME TO SEE HOW THIS ALL
PANS OUT. ALL ADVISORIES/WARNINGS REMAIN IN PLACE WITH NO CHANGES
NEEDED AT THIS TIME.
BY TONIGHT OCCLUDED CYCLONE CONTINUES ITS TREK SLOWLY NORTHEAST
TOWARD YARMOUTH, NS WITH WESTERN EDGE OF PCPN GRADUALLY FADING AWAY
ACROSS OUR AREA AS DEEPER LIFT AND DYNAMICAL SUPPORT FOR PCPN WANE.
SOME LIGHT TAIL-END ACCUMULATIONS POSSIBLE NORTH AND
EAST...OTHERWISE TRENDING DRY OVERNIGHT. DID ADJUST LOW TEMPERATURES
A TAD MILDER THAN PREVIOUS FORECASTS GIVEN CONTINUED OVERCAST SKIES
AND NEAR NEUTRAL THERMAL ADVECTIVE PROCESSES...MAINLY POSITIVE
SINGLE DIGITS...LOCALLY A BIT COLDER FAR WEST WHERE SOME PARTIAL
CLEARING MAY OCCUR LATE.
&&
.SHORT TERM /10 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
AS OF 321 AM EST TUESDAY...HIGH PRESSURE THEN BUILDS EAST INTO
THE REGION BY WEDNESDAY WITH SKIES TRENDING CLEAR TO PARTLY CLOUDY
THROUGH THE COURSE OF THE AFTERNOON. DRY WEATHER CONDITIONS
EXPECTED WITH BLENDED MOS NUMBERS SUPPORTING HIGH TEMPERATURES
GENERALLY IN THE TEENS...PERHAPS LOWER 20S FAR SOUTH.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
AS OF 314 AM EST TUESDAY...DRY WEATHER TO START THE PERIOD AS
RIDGE OF HIGH PRESSURE AND ALOFT RESIDES OVER THE REGION WEDNESDAY
NIGHT. EARLY THURSDAY, THE RIDGE SLIDES EASTWARD WITH SOUTHERLY
FLOW DEVELOPING OVER THE REGION, INCREASING MOISTURE AND
MODERATING TEMPERATURES AHEAD OF A CLIPPER SYSTEM APPROACHING FROM
THE GREAT LAKES REGION. WHILE GFS AND ECMWF AGREE THAT
PRECIPITATION SHIELD WILL ENTER OUR WESTERN ZONES THURSDAY
AFTERNOON, THERE AREA DIFFERENCE REGARDING THE TRACK OF THE SFC
LOW AND THE PROGRESSION OF THE ASSOCIATED MID LEVEL TROUGH. THIS
LOW LOOKS TO BRING SNOW TO THE REGION THROUGH AT LEAST FRIDAY
EVENING. MID LEVEL TROUGH BECOMES NEGATIVELY TILTED ACCORDING TO
BOTH MODELS, THEREFORE AM FAVORING A SLOWER DEPARTURE OF
PRECIPITATION FROM NORTHEASTERN VERMONT AS DEPICTED BY THE ECMWF.
EXPECTING SOME LINGERING POPS INTO EARLY SATURDAY MORNING, BUT
NORTH/NORTHWEST FLOW BEHIND THIS SYSTEM WILL BRING IN DRIER AIR.
SO EXPECT SATURDAY TO BE MOSTLY DRY AT THIS POINT. AT THIS POINT,
EXPECT POTENTIAL SNOWFALL TOTALS TO RANGE FROM 2 TO 5 INCHES.
ANOTHER SYSTEM DEVELOPING IN THE MISSISSIPPI VALLEY WILL MOVE
NORTHEASTWARD LATE SUNDAY INTO MONDAY...BRINGING ANOTHER CHANCE
FOR SNOW FOR THE BEGINNING OF NEXT WEEK.
TEMPERATURES WEDNESDAY NIGHT WILL BE GENERALLY IN THE SINGLE
DIGITS ABOVE AND BELOW ZERO. TEMPERATURES MODERATING IN THE
SOUTHERLY FLOW THURSDAY THROUGH FRIDAY WITH MAXES IN THE 20S AND
MINS IN THE TEENS TO L20S. BEHIND THE CLIPPER LOW, COLD AIR WILL
RETURN WITH MINS OF -15F TO ZERO FOR THE REST OF THE PERIOD. MAXES
WILL REACH SINGLE DIGITS TO MID TEENS SATURDAY THROUGH MONDAY.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
THROUGH 12Z WEDNESDAY...VFR CONDITIONS WILL DETERIORATE TO MVFR
AS SNOW SPREADS NORTHWESTWARD THIS MORNING. EXPECT MVFR
CONDITIONS AND SNOW TO MOVE INTO KRUT BETWEEN 12-15Z...KMPV 13-
15Z...KBTV/KPBG 15Z-17Z...AND KSLK 16Z-18Z. KMSS WILL BE FAR
ENOUGH NORTH AND WEST TO REMAIN VFR. SOME EMBEDDED MODERATE SNOW
IS POSSIBLE WITH IFR/LIFR CONDITIONS AFFECTING KRUT/KMPV 14Z-
22Z...KBTV/KPBG 17Z-21Z AND KSLK 18Z-23Z.
SNOW WILL LIGHTEN AND DIMINISH THIS EVENING WITH MOSTLY DRY
CONDITIONS SETTLING IN AFTER MIDNIGHT/05Z. EXPECT CONDITIONS TO
IMPROVE TO MVFR/VFR AS SNOWFALL COMES TO AN END.
NORTH TO NORTHEAST WINDS OF 6-12KTS WILL INCREASE AND BECOME
GUSTY AROUND 25KTS BY MID MORNING. THIS WILL RESULT IN THE
POTENTIAL FOR AREAS OF BLOWING/DRIFTING SNOW, ESPECIALLY AT RUT
AND MPV WHERE DURATION OF MODERATE SNOW WILL BE LONGEST. EXPECT
GUSTS TO SUBSIDE HEADING INTO TUESDAY EVENING.
OUTLOOK 12Z WEDNESDAY THROUGH SATURDAY...
12Z WEDNESDAY THROUGH 12Z THURSDAY...MAINLY VFR CONDITIONS
EXPECTED AS RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION.
12Z THURSDAY THROUGH 00Z SATURDAY...TRENDING IFR/MVFR IN LIGHT
SNOW AS LOW PRESSURE MOVES EAST FROM THE OHIO VALLEY/GREAT LAKES
STATES.
00Z SATURDAY THROUGH 00Z SUNDAY...VFR CONDITIONS EXPECTING AS A
RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION.
&&
.EQUIPMENT...
AS OF 122 PM EST MONDAY...THE KTYX 88D DOPPLER RADAR LOCATED NEAR
WATERTOWN NEW YORK WILL BE DOWN AT LEAST THROUGH TUESDAY. THIS IS
DUE TO A PEDESTAL DYNAMIC FAULT. ELECTRONICS TECHNICIANS HAVE
ORDERED NEW PARTS TO FIX THIS PROBLEM. HOWEVER...THE NEW PARTS
HAVE NOT ARRIVED AS OF THIS TIME AND THE KTYX RADAR WILL LIKELY
NOT BE RESTORED TO SERVICE UNTIL SOMETIME THIS WEEK.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER STORM WARNING UNTIL 1 AM EST WEDNESDAY FOR VTZ010>012-
019.
WINTER WEATHER ADVISORY UNTIL 1 AM EST WEDNESDAY FOR VTZ004-
007>009-018.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG/TABER
SHORT TERM...JMG
LONG TERM...KGM
AVIATION...KGM
EQUIPMENT...WFO BTV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
656 AM EST TUE JAN 27 2015
.SYNOPSIS...
STRONG COASTAL LOW PRESSURE WILL SPREAD WIDESPREAD LIGHT TO
MODERATE SNOWS ACROSS THE EASTERN HALF OF THE FORECAST AREA TODAY
INTO EARLY THIS EVENING. HIGH PRESSURE RETURNS FOR LATER TONIGHT
THROUGH EARLY THURSDAY WITH SEASONABLY COLD AND MAINLY DRY
WEATHER. MORE LIGHT SNOWS ARE EXPECTED BY THURSDAY NIGHT INTO
FRIDAY AS LOW PRESSURE TRACKS EAST FROM THE GREAT LAKES STATES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 635 AM EST TUESDAY...FORECAST GENERALLY REMAINS ON TRACK
AND ONLY CHANGES AT 630 AM WERE TO MATCH CURRENT T/TD TRENDS
ACROSS THE AREA. I AM GROWING A BIT CONCERNED ON OUR SNOWFALL
TOTALS ON THE NORTHWESTERN EDGE OF THE PCPN SHIELD WITH LATEST
MODEL TRENDS CONTINUING TO SUGGEST DRY LOWER LEVELS WILL TEND TO
OVERCOME MID LEVEL DYNAMICS FOSTERING A GENERAL EROSION OF THE
WESTERN EDGE OF THE PCPN SHIELD ACROSS OUR AREA.
ADDITIONALLY...LOW LEVEL MOISTURE TRANSPORT TO THE NORTHWEST IS
APPEARING TO BE BLOCKED BY THE INTENSE MESOSCALE BAND ACROSS EC/SE
NEW ENGLAND. THIS IS NOT AN UNCOMMON OCCURRENCE...BUT DIFFICULT TO
PREDICT UNTIL IT DEVELOPS. WE`LL HAVE TO SEE HOW THINGS EVOLVE
OVER THE NEXT 3-5 HOURS BUT NO CHANGES AT THIS POINT. PRIOR
DISCUSSION FOLLOWS. HAVE A GREAT DAY.
PRIOR DISCUSSION FROM 321 AM EST TUESDAY...
INTENSE STORM CONTINUES TO DEVELOP OFF THE SOUTHEASTERN NEW
ENGLAND COAST NEAR NANTUCKET EARLY THIS MORNING WITH IMPRESSIVE
3-HOURLY PRESSURE FALLS NEAR 8 MB JUST NORTH OF THE 40N/-70W
BENCHMARK PER MOST RECENT MSAS ANALYSIS. A CLASSIC MILLER-B
EVOLUTION WITH INTENSE FRONTOGENETICAL BANDING FEATURES PIVOTING
SLOWLY NORTH AND WEST ACROSS ERN MA/CT/LI. THE DEVIL IS IN THE
DETAILS HOWEVER...ESPECIALLY IN REGARD TO TOTAL QPF/SNOWFALL
ACROSS OUR AREA. LATEST CAM OUTPUT INCLUDING THE RAP AND HRRR ALL
COMING ON BOARD WITH FAIRLY REALISTIC SOLUTIONS SHOWING WESTERN
EDGE OF STEADIER SNOWS WILL SLOWLY PIVOT NORTH AND WEST INTO VT
THROUGH THE COURSE OF THE MORNING/EARLY AFTERNOON WITH A RATHER
SHARP CUTOFF IN PCPN THE FURTHER NORTH AND WEST ONE PROGRESSES.
MOST PROBLEMATIC IS THE VERY COLD AND DRY ARCTIC AIRMASS IN PLACE
ACROSS OUR AREA. INDEED...LOW TO MID LEVEL DEWPOINTS REMAIN QUITE
LOW THIS MORNING AND THIS WILL TAKE SEVERAL HOURS OF MOISTENING
BEFORE STEADIER SNOWS REACH THE CENTRAL/NRN PORTIONS OF THE STATE.
REMAINING DRY IN NRN NY UNTIL LATE MORNING/EARLY AFTERNOON AND
MAINLY EASTERN PORTIONS OF CLINTON/ESSEX COUNTIES.
OLD RULE OF THUMB THAT USUALLY WORKS WELL HERE IS NOT TO GO TOO
EXTREME ON SNOWFALL TOTALS IF SOUTH COASTAL NEW ENGLAND IS BEARING
THE BRUNT OF THE STORM. RARELY TO WE SEE HEAVY SNOW SWATHS IN
EXCESS OF 200 MI AND THIS STORM WILL BE NO EXCEPTION. PAST
HISTORY ALSO SUGGESTS CLIPPER BOMBS GENERALLY UNDERPERFORM UP HERE
IN LIEU OF THE MORE CLASSIC GULF COAST/SOUTHEASTERN SEABOARD
SYSTEMS AS LONGITUDINAL DEVELOPMENT TYPICALLY OCCURS A BIT TOO FAR
EAST FOR US. IN ANY REGARD FELT THIS MORNINGS NAM HAD THE BEST
HANDLE ON CURRENT SITUATION AND USED ITS SOLUTION IN TANDEM WITH
BLENDED CAM QPF OUTPUT TO ARRIVE AT POP/SNOWFALL GRADIENTS ACROSS
OUR AREA. GFS IDEA BIASED ABOUT 50 MI TOO FAR SOUTH AND EAST AND
EURO QPF TOO SPREAD OUT WITH ITS COARSER RESOLUTION DESPITE A
FAIRLY ACCURATE DEPICTION OF LOW TO MID LEVEL FEATURES.
WHAT THIS ALL SPELLS IS A STEADY 5-10/6-12 INCH SNOWFALL FOR OUR
SOUTHERNMOST COUNTIES...WITH A FAIRLY QUICK DROP OFF IN SNOW
TOTALS NORTH AND WEST. A SW-NE ORIENTED BAND OF 3-7 INCHES STILL
PROGGED FROM ABOUT MIDDLEBURY NORTHEASTWARD THROUGH MONTPELIER AND
ST JOHNSBURY...AND A GENERAL 1-3 INCH SNOWFALL FROM ESSEX COUNTY
NY NORTHEAST INTO THE BURLINGTON/PLATTSBURGH VICINITY AND ST
ALBANS/FRANKLIN COUNTY. LITTLE IF ANY ACCUMULATION FROM A SARANAC
LAKE TO MALONE LINE WEST. THIS IS MORE OR LESS STAYING THE COURSE
AND WE`RE NOW INTO THE WAIT AND SEE TIMEFRAME TO SEE HOW THIS ALL
PANS OUT. ALL ADVISORIES/WARNINGS REMAIN IN PLACE WITH NO CHANGES
NEEDED AT THIS TIME.
BY TONIGHT OCCLUDED CYCLONE CONTINUES ITS TREK SLOWLY NORTHEAST
TOWARD YARMOUTH, NS WITH WESTERN EDGE OF PCPN GRADUALLY FADING AWAY
ACROSS OUR AREA AS DEEPER LIFT AND DYNAMICAL SUPPORT FOR PCPN WANE.
SOME LIGHT TAIL-END ACCUMULATIONS POSSIBLE NORTH AND
EAST...OTHERWISE TRENDING DRY OVERNIGHT. DID ADJUST LOW TEMPERATURES
A TAD MILDER THAN PREVIOUS FORECASTS GIVEN CONTINUED OVERCAST SKIES
AND NEAR NEUTRAL THERMAL ADVECTIVE PROCESSES...MAINLY POSITIVE
SINGLE DIGITS...LOCALLY A BIT COLDER FAR WEST WHERE SOME PARTIAL
CLEARING MAY OCCUR LATE.
&&
.SHORT TERM /WEDNESDAY/...
AS OF 321 AM EST TUESDAY...HIGH PRESSURE THEN BUILDS EAST INTO
THE REGION BY WEDNESDAY WITH SKIES TRENDING CLEAR TO PARTLY CLOUDY
THROUGH THE COURSE OF THE AFTERNOON. DRY WEATHER CONDITIONS
EXPECTED WITH BLENDED MOS NUMBERS SUPPORTING HIGH TEMPERATURES
GENERALLY IN THE TEENS...PERHAPS LOWER 20S FAR SOUTH.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
AS OF 314 AM EST TUESDAY...DRY WEATHER TO START THE PERIOD AS
RIDGE OF HIGH PRESSURE AND ALOFT RESIDES OVER THE REGION WEDNESDAY
NIGHT. EARLY THURSDAY, THE RIDGE SLIDES EASTWARD WITH SOUTHERLY
FLOW DEVELOPING OVER THE REGION, INCREASING MOISTURE AND
MODERATING TEMPERATURES AHEAD OF A CLIPPER SYSTEM APPROACHING FROM
THE GREAT LAKES REGION. WHILE GFS AND ECMWF AGREE THAT
PRECIPITATION SHIELD WILL ENTER OUR WESTERN ZONES THURSDAY
AFTERNOON, THERE AREA DIFFERENCE REGARDING THE TRACK OF THE SFC
LOW AND THE PROGRESSION OF THE ASSOCIATED MID LEVEL TROUGH. THIS
LOW LOOKS TO BRING SNOW TO THE REGION THROUGH AT LEAST FRIDAY
EVENING. MID LEVEL TROUGH BECOMES NEGATIVELY TILTED ACCORDING TO
BOTH MODELS, THEREFORE AM FAVORING A SLOWER DEPARTURE OF
PRECIPITATION FROM NORTHEASTERN VERMONT AS DEPICTED BY THE ECMWF.
EXPECTING SOME LINGERING POPS INTO EARLY SATURDAY MORNING, BUT
NORTH/NORTHWEST FLOW BEHIND THIS SYSTEM WILL BRING IN DRIER AIR.
SO EXPECT SATURDAY TO BE MOSTLY DRY AT THIS POINT. AT THIS POINT,
EXPECT POTENTIAL SNOWFALL TOTALS TO RANGE FROM 2 TO 5 INCHES.
ANOTHER SYSTEM DEVELOPING IN THE MISSISSIPPI VALLEY WILL MOVE
NORTHEASTWARD LATE SUNDAY INTO MONDAY...BRINGING ANOTHER CHANCE
FOR SNOW FOR THE BEGINNING OF NEXT WEEK.
TEMPERATURES WEDNESDAY NIGHT WILL BE GENERALLY IN THE SINGLE
DIGITS ABOVE AND BELOW ZERO. TEMPERATURES MODERATING IN THE
SOUTHERLY FLOW THURSDAY THROUGH FRIDAY WITH MAXES IN THE 20S AND
MINS IN THE TEENS TO L20S. BEHIND THE CLIPPER LOW, COLD AIR WILL
RETURN WITH MINS OF -15F TO ZERO FOR THE REST OF THE PERIOD. MAXES
WILL REACH SINGLE DIGITS TO MID TEENS SATURDAY THROUGH MONDAY.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
THROUGH 12Z WEDNESDAY...VFR CONDITIONS WILL DETERIORATE TO MVFR
AS SNOW SPREADS NORTHWESTWARD THIS MORNING. EXPECT MVFR
CONDITIONS AND SNOW TO MOVE INTO KRUT BETWEEN 12-15Z...KMPV 13-
15Z...KBTV/KPBG 15Z-17Z...AND KSLK 16Z-18Z. KMSS WILL BE FAR
ENOUGH NORTH AND WEST TO REMAIN VFR. SOME EMBEDDED MODERATE SNOW
IS POSSIBLE WITH IFR/LIFR CONDITIONS AFFECTING KRUT/KMPV 14Z-
22Z...KBTV/KPBG 17Z-21Z AND KSLK 18Z-23Z.
SNOW WILL LIGHTEN AND DIMINISH THIS EVENING WITH MOSTLY DRY
CONDITIONS SETTLING IN AFTER MIDNIGHT/05Z. EXPECT CONDITIONS TO
IMPROVE TO MVFR/VFR AS SNOWFALL COMES TO AN END.
NORTH TO NORTHEAST WINDS OF 6-12KTS WILL INCREASE AND BECOME
GUSTY AROUND 25KTS BY MID MORNING. THIS WILL RESULT IN THE
POTENTIAL FOR AREAS OF BLOWING/DRIFTING SNOW, ESPECIALLY AT RUT
AND MPV WHERE DURATION OF MODERATE SNOW WILL BE LONGEST. EXPECT
GUSTS TO SUBSIDE HEADING INTO TUESDAY EVENING.
OUTLOOK 12Z WEDNESDAY THROUGH SATURDAY...
12Z WEDNESDAY THROUGH 12Z THURSDAY...MAINLY VFR CONDITIONS
EXPECTED AS RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION.
12Z THURSDAY THROUGH 00Z SATURDAY...TRENDING IFR/MVFR IN LIGHT
SNOW AS LOW PRESSURE MOVES EAST FROM THE OHIO VALLEY/GREAT LAKES
STATES.
00Z SATURDAY THROUGH 00Z SUNDAY...VFR CONDITIONS EXPECTING AS A
RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION.
&&
.EQUIPMENT...
AS OF 122 PM EST MONDAY...THE KTYX 88D DOPPLER RADAR LOCATED NEAR
WATERTOWN NEW YORK WILL BE DOWN AT LEAST THROUGH TUESDAY. THIS IS
DUE TO A PEDESTAL DYNAMIC FAULT. ELECTRONICS TECHNICIANS HAVE
ORDERED NEW PARTS TO FIX THIS PROBLEM. HOWEVER...THE NEW PARTS
HAVE NOT ARRIVED AS OF THIS TIME AND THE KTYX RADAR WILL LIKELY
NOT BE RESTORED TO SERVICE UNTIL SOMETIME THIS WEEK.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER STORM WARNING UNTIL 1 AM EST WEDNESDAY FOR VTZ010>012-
019.
WINTER WEATHER ADVISORY UNTIL 1 AM EST WEDNESDAY FOR VTZ004-
007>009-018.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG
SHORT TERM...JMG
LONG TERM...KGM
AVIATION...KGM
EQUIPMENT...WFO BTV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
635 AM EST TUE JAN 27 2015
.SYNOPSIS...
STRONG COASTAL LOW PRESSURE WILL SPREAD WIDESPREAD LIGHT TO
MODERATE SNOWS ACROSS THE EASTERN HALF OF THE FORECAST AREA TODAY
INTO EARLY THIS EVENING. HIGH PRESSURE RETURNS FOR LATER TONIGHT
THROUGH EARLY THURSDAY WITH SEASONABLY COLD AND MAINLY DRY
WEATHER. MORE LIGHT SNOWS ARE EXPECTED BY THURSDAY NIGHT INTO
FRIDAY AS LOW PRESSURE TRACKS EAST FROM THE GREAT LAKES STATES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 635 AM EST TUESDAY...FORECAST GENERALLY REMAINS ON TRACK
AND ONLY CHANGES AT 630 AM WERE TO MATCH CURRENT T/TD TRENDS
ACROSS THE AREA. I AM GROWING A BIT CONCERNED ON OUR SNOWFALL
TOTALS ON THE NORTHWESTERN EDGE OF THE PCPN SHIELD WITH LATEST
MODEL TRENDS CONTINUING TO SUGGEST DRY LOWER LEVELS WILL TEND TO
OVERCOME MID LEVEL DYNAMICS FOSTERING A GENERAL EROSION OF THE
WESTERN EDGE OF THE PCPN SHIELD ACROSS OUR AREA.
ADDITIONALLY...LOW LEVEL MOISTURE TRANSPORT TO THE NORTHWEST IS
APPEARING TO BE BLOCKED BY THE INTENSE MESOSCALE BAND ACROSS EC/SE
NEW ENGLAND. THIS IS NOT AN UNCOMMON OCCURRENCE...BUT DIFFICULT TO
PREDICT UNTIL IT DEVELOPS. WE`LL HAVE TO SEE HOW THINGS EVOLVE
OVER THE NEXT 3-5 HOURS BUT NO CHANGES AT THIS POINT. PRIOR
DISCUSSION FOLLOWS. HAVE A GREAT DAY.
PRIOR DISCUSSION FROM 321 AM EST TUESDAY...
INTENSE STORM CONTINUES TO DEVELOP OFF THE SOUTHEASTERN NEW
ENGLAND COAST NEAR NANTUCKET EARLY THIS MORNING WITH IMPRESSIVE
3-HOURLY PRESSURE FALLS NEAR 8 MB JUST NORTH OF THE 40N/-70W
BENCHMARK PER MOST RECENT MSAS ANALYSIS. A CLASSIC MILLER-B
EVOLUTION WITH INTENSE FRONTOGENETICAL BANDING FEATURES PIVOTING
SLOWLY NORTH AND WEST ACROSS ERN MA/CT/LI. THE DEVIL IS IN THE
DETAILS HOWEVER...ESPECIALLY IN REGARD TO TOTAL QPF/SNOWFALL
ACROSS OUR AREA. LATEST CAM OUTPUT INCLUDING THE RAP AND HRRR ALL
COMING ON BOARD WITH FAIRLY REALISTIC SOLUTIONS SHOWING WESTERN
EDGE OF STEADIER SNOWS WILL SLOWLY PIVOT NORTH AND WEST INTO VT
THROUGH THE COURSE OF THE MORNING/EARLY AFTERNOON WITH A RATHER
SHARP CUTOFF IN PCPN THE FURTHER NORTH AND WEST ONE PROGRESSES.
MOST PROBLEMATIC IS THE VERY COLD AND DRY ARCTIC AIRMASS IN PLACE
ACROSS OUR AREA. INDEED...LOW TO MID LEVEL DEWPOINTS REMAIN QUITE
LOW THIS MORNING AND THIS WILL TAKE SEVERAL HOURS OF MOISTENING
BEFORE STEADIER SNOWS REACH THE CENTRAL/NRN PORTIONS OF THE STATE.
REMAING DRY IN NRN NY UNTIL LATE MORNING/EARLY AFTERNOON AND
MAINLY EASTERN PORTIONS OF CLINTON/ESSEX COUNTIES.
OLD RULE OF THUMB THAT USUALLY WORKS WELL HERE IS NOT TO GO TOO
EXTREME ON SNOWFALL TOTALS IF SOUTH COASTAL NEW ENGLAND IS BEARING
THE BRUNT OF THE STORM. RARELY TO WE SEE HEAVY SNOW SWATHS IN
EXCESS OF 200 MI AND THIS STORM WILL BE NO EXCEPTION. PAST
HISTORY ALSO SUGGESTS CLIPPER BOMBS GENERALLY UNDERPERFORM UP HERE
IN LIEU OF THE MORE CLASSIC GULF COAST/SOUTHEASTERN SEABOARD
SYSTEMS AS LONGITUDINAL DEVELOPMENT TYPICALLY OCCURS A BIT TOO FAR
EAST FOR US. IN ANY REGARD FELT THIS MORNINGS NAM HAD THE BEST
HANDLE ON CURRENT SITUATION AND USED ITS SOLUTION IN TANDEM WITH
BLENDED CAM QPF OUTPUT TO ARRIVE AT POP/SNOWFALL GRADIENTS ACROSS
OUR AREA. GFS IDEA BIASED ABOUT 50 MI TOO FAR SOUTH AND EAST AND
EURO QPF TOO SPREAD OUT WITH ITS COARSER RESOLUTION DESPITE A
FAIRLY ACCURATE DEPICTION OF LOW TO MID LEVEL FEATURES.
WHAT THIS ALL SPELLS IS A STEADY 5-10/6-12 INCH SNOWFALL FOR OUR
SOUTHERNMOST COUNTIES...WITH A FAIRLY QUICK DROP OFF IN SNOW
TOTALS NORTH AND WEST. A SW-NE ORIENTED BAND OF 3-7 INCHES STILL
PROGGED FROM ABOUT MIDDLEBURY NORTHEASTWARD THROUGH MONTPELIER AND
ST JOHNSBURY...AND A GENERAL 1-3 INCH SNOWFALL FROM ESSEX COUNTY
NY NORTHEAST INTO THE BURLINGTON/PLATTSBURGH VICINITY AND ST
ALBANS/FRANKLIN COUNTY. LITTLE IF ANY ACCUMULATION FROM A SARANAC
LAKE TO MALONE LINE WEST. THIS IS MORE OR LESS STAYING THE COURSE
AND WE`RE NOW INTO THE WAIT AND SEE TIMEFRAME TO SEE HOW THIS ALL
PANS OUT. ALL ADVISORIES/WARNINGS REMAIN IN PLACE WITH NO CHANGES
NEEDED AT THIS TIME.
BY TONIGHT OCCLUDED CYCLONE CONTINUES ITS TREK SLOWLY NORTHEAST
TOWARD YARMOUTH, NS WITH WESTERN EDGE OF PCPN GRADUALLY FADING AWAY
ACROSS OUR AREA AS DEEPER LIFT AND DYNAMICAL SUPPORT FOR PCPN WANE.
SOME LIGHT TAIL-END ACCUMULATIONS POSSIBLE NORTH AND
EAST...OTHERWISE TRENDING DRY OVERNIGHT. DID ADJUST LOW TEMPERATURES
A TAD MILDER THAN PREVIOUS FORECASTS GIVEN CONTINUED OVERCAST SKIES
AND NEAR NEUTRAL THERMAL ADVECTIVE PROCESSES...MAINLY POSITIVE
SINGLE DIGITS...LOCALLY A BIT COLDER FAR WEST WHERE SOME PARTIAL
CLEARING MAY OCCUR LATE.
&&
.SHORT TERM /WEDNESDAY/...
AS OF 321 AM EST TUESDAY...HIGH PRESSURE THEN BUILDS EAST INTO
THE REGION BY WEDNESDAY WITH SKIES TRENDING CLEAR TO PARTLY CLOUDY
THROUGH THE COURSE OF THE AFTERNOON. DRY WEATHER CONDITIONS
EXPECTED WITH BLENDED MOS NUMBERS SUPPORTING HIGH TEMPERATURES
GENERALLY IN THE TEENS...PERHAPS LOWER 20S FAR SOUTH.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
AS OF 314 AM EST TUESDAY...DRY WEATHER TO START THE PERIOD AS
RIDGE OF HIGH PRESSURE AND ALOFT RESIDES OVER THE REGION WEDNESDAY
NIGHT. EARLY THURSDAY, THE RIDGE SLIDES EASTWARD WITH SOUTHERLY
FLOW DEVELOPING OVER THE REGION, INCREASING MOISTURE AND
MODERATING TEMPERATURES AHEAD OF A CLIPPER SYSTEM APPROACHING FROM
THE GREAT LAKES REGION. WHILE GFS AND ECMWF AGREE THAT
PRECIPITATION SHIELD WILL ENTER OUR WESTERN ZONES THURSDAY
AFTERNOON, THERE AREA DIFFERENCE REGARDING THE TRACK OF THE SFC
LOW AND THE PROGRESSION OF THE ASSOCIATED MID LEVEL TROUGH. THIS
LOW LOOKS TO BRING SNOW TO THE REGION THROUGH AT LEAST FRIDAY
EVENING. MID LEVEL TROUGH BECOMES NEGATIVELY TILTED ACCORDING TO
BOTH MODELS, THEREFORE AM FAVORING A SLOWER DEPARTURE OF
PRECIPITATION FROM NORTHEASTERN VERMONT AS DEPICTED BY THE ECMWF.
EXPECTING SOME LINGERING POPS INTO EARLY SATURDAY MORNING, BUT
NORTH/NORTHWEST FLOW BEHIND THIS SYSTEM WILL BRING IN DRIER AIR.
SO EXPECT SATURDAY TO BE MOSTLY DRY AT THIS POINT. AT THIS POINT,
EXPECT POTENTIAL SNOWFALL TOTALS TO RANGE FROM 2 TO 5 INCHES.
ANOTHER SYSTEM DEVELOPING IN THE MISSISSIPPI VALLEY WILL MOVE
NORTHEASTWARD LATE SUNDAY INTO MONDAY...BRINGING ANOTHER CHANCE
FOR SNOW FOR THE BEGINNING OF NEXT WEEK.
TEMPERATURES WEDNESDAY NIGHT WILL BE GENERALLY IN THE SINGLE
DIGITS ABOVE AND BELOW ZERO. TEMPERATURES MODERATING IN THE
SOUTHERLY FLOW THURSDAY THROUGH FRIDAY WITH MAXES IN THE 20S AND
MINS IN THE TEENS TO L20S. BEHIND THE CLIPPER LOW, COLD AIR WILL
RETURN WITH MINS OF -15F TO ZERO FOR THE REST OF THE PERIOD. MAXES
WILL REACH SINGLE DIGITS TO MID TEENS SATURDAY THROUGH MONDAY.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
THROUGH 06Z WEDNESDAY...VFR CONDITIONS PERSIST FOR THE NEXT
COUPLE HOURS, WITH MVFR CIGS/VSBYS SPREADING NORTHWESTWARD
ASSOCIATED WITH APPROACHING SNOW. LOW-LEVEL DRY AIR FROM NORTHERLY
ARCTIC AIR HAS SLOWED PROGRESSION OF SNOW AND DETERIORATING
CONDITIONS. EXPECT MVFR CONDITIONS TO MOVE INTO KRUT BETWEEN 09Z-
11Z...KMPV 11Z- 14Z...KBTV/KPBG 15Z-17Z...AND KSLK 16Z-18Z. KMSS
WILL BE FAR ENOUGH NORTH AND WEST TO REMAIN VFR.
HEAVIER SNOW WITH IFR-LIFR CONDITIONS WILL MOVE INTO THE
REGION...FOLLOWING THE SAME TRENDS AS ONSET OF SNOW APPROXIMATELY
2-4 HOURS AFTER THE ONSET OF SNOW. EXPECT THIS BAND OF MODERATE
SNOWFALL TO WEAKEN IN THE MID AFTERNOON, AROUND 20-22Z. AS
SNOWFALL LIGHTENS, CONDITIONS WILL IMPROVE TO MVFR/VFR.
WINDS WILL BE NORTH TO NORTHEAST AROUND 6-12 KTS THIS MORNING,
INCREASING AND BECOMING GUSTY (UP TO 25 KTS) INTO MID TO LATE
MORNING. POTENTIAL FOR AREAS OF BLOWING/DRIFTING SNOW, ESPECIALLY
AT RUT AND MPV WHERE DURATION OF MODERATE SNOW WILL BE LONGEST.
EXPECT GUSTS TO SUBSIDE HEADING INTO TUESDAY EVENING.
OUTLOOK 06Z WEDNESDAY THROUGH SATURDAY...
06Z THROUGH 12Z WEDNESDAY...MAINLY MVFR IN SNOW FROM DEEPENING
STORM OFF THE NEW ENGLAND COAST...ESPECIALLY VERMONT TERMINALS AND
KPBG. KMSS LIKELY TO REMAIN PCPN FREE MUCH OF THE PERIOD WITH
CONTINUED VFR CONDS. GUSTY NORTH WINDS TO 25 KTS
POSSIBLE...ESPECIALLY AT KPBG/KBTV WHERE NORTHERLY CHANNELING
EFFECTS MAY OCCUR.
12Z WEDNESDAY THROUGH 12Z THURSDAY...MAINLY VFR CONDITIONS
EXPECTED AS RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION.
12Z THURSDAY THROUGH 00Z SATURDAY...TRENDING IFR/MVFR IN LIGHT
SNOW AS LOW PRESSURE MOVES EAST FROM THE OHIO VALLEY/GREAT LAKES
STATES.
00Z SATURDAY THROUGH 00Z SUNDAY...VFR CONDITIONS EXPECTING AS A
RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION.
&&
.EQUIPMENT...
AS OF 122 PM EST MONDAY...THE KTYX 88D DOPPLER RADAR LOCATED NEAR
WATERTOWN NEW YORK WILL BE DOWN AT LEAST THROUGH TUESDAY. THIS IS
DUE TO A PEDESTAL DYNAMIC FAULT. ELECTRONICS TECHNICIANS HAVE
ORDERED NEW PARTS TO FIX THIS PROBLEM. HOWEVER...THE NEW PARTS
HAVE NOT ARRIVED AS OF THIS TIME AND THE KTYX RADAR WILL LIKELY
NOT BE RESTORED TO SERVICE UNTIL SOMETIME THIS WEEK.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER STORM WARNING UNTIL 1 AM EST WEDNESDAY FOR VTZ010>012-
019.
WINTER WEATHER ADVISORY UNTIL 1 AM EST WEDNESDAY FOR VTZ004-
007>009-018.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG
SHORT TERM...JMG
LONG TERM...KGM
AVIATION...KGM
EQUIPMENT...WFO BTV
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1256 AM EST TUE JAN 27 2015
.SYNOPSIS...
EARLY THIS MORNING, THE CLIPPER THAT BROUGHT SNOW SHOWERS TO THE
REGION WILL BECOME A POWERFUL NOR EASTER. A PERIOD OF HEAVY SNOW
IS POSSIBLE OVER THE POCONOS TO CATSKILLS TODAY INTO THE EVENING.
A COLD WINTRY WEATHER PATTERN WILL PERSIST THROUGH THE WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
10 PM UPDATE...
LATEST HRRR IS KEEPING THE HEAVY SNOW BAND OUT OF PIKE/SULLIVAN
THROUGH THE OVERNIGHT HOURS, SO CONFIDENCE IN INTENSE SNOW IN THE
WARNING AREA OVERNIGHT IS DROPPING. SNOWFALL AMOUNTS FROM EARLIER
TURNED OUT TO BE HIGHER THAN EXPECTED DUE TO A HIGH SNOW TO H20
RATIO. MANY LOCATIONS HAVE REPORTED 3 TO 5 INCHES OF SNOW ALREADY,
SO WE MAY STILL REACH WARNING CRITERIA.
NO CHANGES TO FLAGS AT THIS TIME. WE HAVE LOWERED AMOUNTS SLIGHTLY
FOR THE OVERNIGHT HOURS.
425 PM UPDATE...
ISSUED A LAST SECOND WINTER WEATHER ADVISORY FOR PORTIONS OF
CENTRAL SO TIER AND FINGER LAKES. WE ARE RECEIVING REPORTS OF 3 TO
4 INCHES OF SNOW FROM TRAINED SPOTTERS IN THIS AREA, AND HRRR
HOLDS ACTIVITY OVER THE NEW ADVISORY AREA THROUGH THE EVENING. NEW
PROJECTIONS ARE FOR 3 TO 6 INCHES OVER THIS REGION.
330 PM EST UPDATE...
THE CALM BEFORE THE STORM...
LIGHT SNOW SHOWERS HAVE ADVANCED NORTHWARD THIS AFTERNOON AND NOW
HAVE REACHED PRETTY MUCH THE WHOLE CWA. THESE SHOWERS ARE EXPECTED
TO CONTINUE TO LIFT NORTHWARD THIS EVENING AND ADDITIONAL
ACCUMULATIONS OF 1 TO 3 INCHES OF SNOW ARE POSSIBLE... ESPECIALLY
OVER THE FINGER LAKE REGION.
TEMPS HAVE RISEN QUITE A BIT FROM THIS MORNING AND CURRENTLY RANGE
IN THE MID TEENS TO LOW 20S. TEMPS MAY INCREASE A COUPLE MORE
DEGREES THIS AFTERNOON THEN WILL SLOWLY DECREASE AFTER SUNSET.
THIS EVENING THE CLIPPER THAT HAVE BROUGHT THE CWA SNOW THIS
AFTERNOON WILL TRANSITION OVER TO A POWERFUL NOR`EASTER AND CREATE
COPIOUS AMOUNTS OF SNOWFALL FOR MUCH OF THE NORTHEAST. THIS
NOR`EASTER WILL BE DISCUSSED IN THE FOLLOWING SECTION.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM WEDNESDAY/...
330 PM EST UPDATE...
AS MENTIONED BEFORE THE CLIPPER WILL TRANSFORM INTO A POWERFUL
NOR`EASTER AND CREATE AN ALMOST STAND STILL FOR MUCH OF THE NEW
ENGLAND COAST. SNOW FROM THIS SYSTEM IS STILL EXPECTED TO START
AFTER 06Z TONIGHT AND MAY PREVAIL THROUGH THE LATE EVENING HOURS
ON TUESDAY. WE CONTINUE TO REMAIN ON THE FAR OUTER EDGE OF THIS
SYSTEM. WITH THAT BEING SAID... THERE ARE STILL SOME UNCERTAINTIES
WITH HOW MUCH SNOWFALL WILL FALL IN OUR CWA FROM THIS SYSTEM.
CONFIDENCE IS DECREASING THAT WE WILL REACH WARNING CRITERIA FOR
SULLIVAN AND PIKE COUNTY. ATTM IT APPEARS THAT THE GREATEST
MOISTURE AXIS WILL REMAIN WELL TO OUR EAST. ALSO... WITH EACH NEW
GUIDANCE RUN HINTING AT THAT EDGE SHIFTING EVER SO SLIGHTLY
EAST... WE MAY REACH ADVISORY AND NOT WARNING CRITERIA FOR THOSE
TWO COUNTIES. IT IS STILL TOO FAR OUT IN THE EVOLUTION OF THIS
STORM TO KNOW WHERE EXACTLY THE CUTOFF OF WARNING CRITERIA WILL
BE... THUS KEPT PREVIOUS WARNING/ADVISORY LOCATIONS THE SAME.
STORM TOTAL SNOWFALL ACCUMULATIONS WERE MODIFIED JUST SLIGHTLY
FROM THE PREVIOUS FORECAST. THE HIGHEST EXPECTED SNOWFALL
ACCUMULATIONS OVER THE CWA ARE STILL EXPECTED TO BE IN THE WESTERN
CATSKILLS AND THE POCONO MOUNTAIN REGION. ATTM... KEPT TEN TO
FOURTEEN INCHES TOTAL OVER THESE REGIONS. WE WILL CLOSELY MONITOR
THE OVERALL EVOLUTION OF THIS STORM AND UPDATE AS NECESSARY.
WINDS WILL BECOME GUSTY DURING THE DAY TOMORROW AND CREATE BLOWING
AND DRIFTING SNOW. WINDS ARE EXPECTED TO RANGE FROM 10 TO 20 MPH
WITH GUSTS UP TO 30. THIS WILL CREATE HAZARDOUS DRIVING
CONDITIONS.
TEMPS AFTER THIS SYSTEM PULLS AWAY WILL BE VERY COLD FALLING INTO
THE SINGLE DIGITS OR SLIGHTLY BELOW ZERO.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
220 PM UPDATE...
HIGH PRESSURE BUILDS IN QUICKLY BHND DEPARTING NOR`EASTER WITH CLDS
CLRNG DRG THE MRNG FM WEST TO EAST. H8 TEMPS WARM TO NR -10C
YIELDING HIGHS IN THE L/M 20S. S/WV RIDGING WORKS IN ALOFT WED NGT
WITH MOCLR SKIES THRU MOST OF THE OVRNGT BFR CLOUDING UP FM THE WEST
BY 12Z. DRY WX EXPECTED TO HOLD THRU THUR MRNG.
WARM ADVECTION WL OVRSPRD WRN ZONES THURSDAY MORNING BRINGING A LO
CHC OF LGT SNOW TO FINGER LKS AREA. UPR TROF AND ASSOC FRONTAL
SYSTEM SWINGS THRU THURSDAY NGT AND WITH ALL MODELS INDICATING THIS
SOLN HV OPTED TO GO LKLY POPS FOR SNOW BTWN 00Z AND 12Z FRIDAY. NW
FLOW WL CONTINUE BHND SYSTEM LEADING TO ANOTHER CHC FOR LK EFFECT
SNOW SHOWERS THRU FRI NGT UNTIL NEXT HIGH BUILDS IN.
BASICALLY FOLLOWED WPC GUIDANCE THRU THE END OF THE LONG TERM WITH
HIPRES RESULTING IN DRY WX THRU THE FIRST HALF OF THE WEEKEND. NEXT
CHC FOR SNOW SHOWERS APPEAR TO MV IN ON SUNDAY.
MODELS DIFFER SIGNIFICANTLY LATE IN THE LONG TERM WITH CLD CANADIAN
AIR FILTERING IN AS 12Z GFS HAS LOPRES OVR TOP OF CWA AS OPPOSED
TO EC INDICATING NRLY FLOW WITH HIPRES. THUS HV GONE WITH WPC
NUMBERS FOR LOWS NEXT MON MRNG WITH LOW TEMPS BLO ZERO.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
1230 AM UPDATE...
MAINLY VFR CONDITIONS. A NORTH TO SOUTH BAND OF SNOW OVER ELM
GIVING THEM MVFR VSBYS AND AT TIMES IFR VSBYS EARLY. THIS BAND
WILL TAPER OFF TO FLURRIES AND CONDITIONS WILL RISE TO VFR.
THE MAIN SHIELD OF SNOW OVER SE NY IS EXPECTED TO GET TO KRME WITH
WEAK LAKE ENHANCEMENT OFF LAKE ONTARIO. POSSIBLE IFR VSBYS 19 TO
23Z BUT MAINLY MVFR CIG/VSBY. ALSO WITH THE NW FLOW SYR ITH BGM
SHOULD FALL TO MVFR IN SNOW SHOWERS.
ELM AVP AFTER 12Z VFR WITH ONLY FLURRIES.
N TO NE WINDS AT 4 TO 8 KTS EARLY THIS MORNING SHIFT TO NW TO N AT
10 WITH GUSTS TO 20 LATE MORNING INTO EARLY EVE. SLIGHTLY WEAKER
WINDS LATE EVENING OUT OF THE NW.
OUTLOOK...
TUE NGT-WED...LINGERING LAKE EFFECT -SHSN AND MVFR CIGS/VSBYS
POSSIBLE MAINLY NY TERMINALS INTO WED MORNING...OTHERWISE MAINLY
VFR.
THU AND FRI...RESTRICTIONS FROM -SN.
SAT...BECOMING VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER STORM WARNING UNTIL 6 PM EST THIS EVENING FOR PAZ048.
WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR PAZ040-
072.
NY...WINTER STORM WARNING UNTIL 6 PM EST THIS EVENING FOR NYZ062.
WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR NYZ046-
057.
WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR NYZ015-
016-022>024.
&&
$$
SYNOPSIS...KAH
NEAR TERM...DJP/KAH
SHORT TERM...KAH
LONG TERM...PVF
AVIATION...TAC
AREA FORECAST DISCUSSION
NWS RALEIGH NC
645 AM EST TUE JAN 27 2015
.SYNOPSIS...STRONG LOW PRESSURE OFF NEW ENGLAND THIS MORNING WILL
LIFT NORTHEAST AWAY FROM OUR AREA TODAY. HIGH PRESSURE WILL BUILD IN
FROM THE NORTHWEST THIS AFTERNOON THROUGH EARLY THURSDAY. ANOTHER
CLIPPER LOW PRESSURE SYSTEM WILL SWING BY JUST TO OUR NORTH LATE
THURSDAY THROUGH THURSDAY NIGHT... THEN HIGH PRESSURE WILL AGAIN
BUILD INTO OUR AREA FROM THE NORTHWEST ON FRIDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY NIGHT/...
AS OF 240 AM TUESDAY...
TODAY AND TONIGHT: FRONTAL SYSTEM IS CURRENTLY MOVING THROUGH THE
AREA AS LOW PRESSURE CONTINUES TO DEEPEN ACROSS THE DELMARVA. THE
CWA IS CURRENTLY SPLIT BETWEEN DRIER AIR TO THE WEST OF ROUTE 1 AND
MORE MOISTURE TO THE EAST. A BAND OF PRECIPITATION HAS SET UP ALONG
WHAT APPEARS TO BE THE FRONTAL BOUNDARY AND HAS BROUGHT SOME
SCATTERED REPORTS OF A RAIN/SNOW MIX FROM PERSON COUNTY DOWN THROUGH
WAKE COUNTY WITH MOSTLY RAIN OR DRIZZLE SOUTH OF THERE. THIS BAND
WILL MOVE GRADUALLY EASTWARD THROUGH THE EARLY MORNING HOURS TOWARDS
TEH I-95 CORRIDOR AND THE EASTERN TIER OF COUNTIES. SCATTERED
REPORTS OF LIGHT SNOW OR RAIN WILL CONTINUE THROUGH THE MORNING
BEFORE MOST LOCALES DRY OUT. THE THREAT FOR SNOW SHOULD END AFTER
12Z AS RAP FORECAST SOUNDINGS INDICATE SIGNIFICANT DRYING IN THE
SNOW GROWTH ZONE. NO ACCUMULATION IS EXPECTED OR ANY IMPACTS FROM
THE SNOW ASIDE FROM A POTENTIAL DUSTING ON ELEVATED SURFACES AT BEST
AS SOIL TEMPERATURES ARE STILL NEAR 40 DEGREES.
THIS SETUP HAS ALSO CAUSED A SPLIT IN CLOUD COVER WITH AREAS UNDER
AND EAST OF THE PRECIPITATION BAND EXPERIENCING MAINLY MVFR CEILINGS
WITH VFR CONDITIONS BACK TO THE WEST. A FEW WIND GUSTS STILL OUT
THERE UP TO 20 KTS OR SO OUT OF THE NORTHWEST. GUSTS MAY DIE OFF
TOWARDS SUNRISE BUT WILL PICK UP AGAIN LATER THIS AFTERNOON.
TEMPERATURES THIS AFTERNOON IN THE LOW TO MID 40S NE TO SW AS CLOUDS
LINGER LONGER AND COLD AIR ADVECTION IS MORE PRONOUNCED IN THE
NORTHEAST. EXPECT DRYING TO CONTINUE INTO TONIGHT WITH CLEARING
SKIES BUT WINDS REMAINING 5-10 KTS SO NOT EXACTLY GREAT FOR
RADIATIONAL COOLING BUT TEMPS WILL STILL MANAGE TO DROP INTO THE
MIDDLE 20S WITH THE CHANGE IN AIRMASS.
WEDNESDAY AND WEDNESDAY NIGHT: A DRY DAY EXPECTED FOR WEDNESDAY AS
CENTRAL NC IS SANDWICHED BETWEEN THE EXITING BLIZZARD TO THE
NORTHEAST AND INCOMING HIGH PRESSURE TO THE NORTHWEST. SURFACE
PRESSURE GRADIENT WILL RELAX A LITTLE BUT STILL A GOOD COLD AIR
ADVECTION REGIME BOTH AT THE SURFACE AND ALOFT ON THE BACK SIDE OF
THE UPPER LEVEL TROUGH. THIS WILL KEEP TEMPS DOWN IN THE LOW TO MID
40S...ABOUT 10 DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. WINDS 5-
10 KTS OUT OF THE NORTH VEERING TO NORTHEASTERLY LATER IN THE DAY.
CLOUDS WILL GRADUALLY INCREASE IN THE NORTHWEST ON WEDNESDAY NIGHT
AS THE NEXT LOW PRESSURE SYSTEM MOVES INTO THE OHIO VALLEY. THIS
WILL HELP TO KEEP LOW TEMPERATURES UP IN THE TRIAD. GENERALLY MID
20S BUT POSSIBLY SOME LOWER 20S IN OUR EASTERN NORMALLY COLD ZONES.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
AS OF 200 AM TUESDAY...
THU/THU NIGHT: THE GREAT LAKES SHORTWAVE TROUGH WILL TRACK ESE THEN
EASTWARD ACROSS THE NORTHEAST/MIDATLANTIC STATES... TRACKING THROUGH
THE BASE OF THE POLAR LOW OVER HUDSON BAY... WHILE ITS CORRESPONDING
SURFACE LOW CROSSES THE OH VALLEY AND MIDATLANTIC COAST. AFTER A
CHILLY MORNING WITH THE SURFACE RIDGE OVERHEAD... INCREASING
SOUTHERLY LOW LEVEL FLOW AS THE HIGH SHIFTS SSE WILL ALLOW FOR A
MODEST RECOVERY IN THICKNESSES... BUT STILL BELOW NORMAL... AND THE
TEMP RISE WILL BE HINDERED BY THICKENING AND LOWERING CLOUDS WITH
APPROACHING WEAK MID LEVEL DPVA AND LOW LEVEL FRONTAL ZONE. BUT
MODELS STILL SHOW PW VALUES JUST BARELY REACHING ABOVE NORMAL... AND
GFS/NAM BUFR FORECAST SOUNDINGS SHOW A DRY SUBCLOUD LAYER BELOW 850
MB THROUGH THU. MODEL QPF IS ALSO SCANT WITH THE GFS/NAM/SREF MEAN
STAYING DRY OVER CENTRAL NC THROUGH THU NIGHT. AFTER 00Z THE COLUMN
STARTS TO DRY OUT ALOFT BEHIND THE 700 MB TROUGH... AND JUST AHEAD
OF THE SURFACE FRONT WHICH IS EXPECTED TO SWEEP EAST THROUGH CENTRAL
NC AFTER MIDNIGHT. WILL TRIM BACK EXISTING SLIGHT CHANCE POPS A
BIT... FOCUSING THEM LATE THU AFTERNOON UNTIL SHORTLY AFTER
MIDNIGHT... HOWEVER AM RELUCTANT TO REMOVE THEM ENTIRELY AS THE
ECMWF CONTINUES TO GENERATE LIGHT PRECIP LATE THU AFTERNOON AND THU
EVENING. EXPECT HIGHS THU IN THE MID 40S TO AROUND 50. LOWS THU
NIGHT 32-38.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 200 AM TUESDAY...
FRI-SAT: THE MID LEVEL TROUGH AXIS WILL BE SWINGING TO OUR EAST FRI
MORNING WITH THE SURFACE COLD FRONT PUSHING OFF THE NC COAST. NW LOW
LEVEL FLOW WILL BRING IN COOLER AIR AS HIGH PRESSURE INITIALLY
CENTERED OVER NRN MINN DRIFTS SOUTHEAST... BUILDING INTO AND OVER
THE MIDATLANTIC THROUGH VA/ERN NC THROUGH SAT. SHOULD SEE MOSTLY
CLEAR SKIES FRI/FRI NIGHT... FOLLOWED BY INCREASING HIGH THIN CLOUDS
SAT AS WE START TO SEE INITIAL ENERGY EJECTING FROM THE DESERT SW
LOW TRACK EASTWARD WITHIN CONFLUENT NW MID LEVEL FLOW. WITH FALLING
THICKNESSES FRI... EXPECT BELOW-NORMAL HIGHS IN THE MID 40S TO LOWER
50S. LOWS FRI NIGHT IN THE MID 20S... THEN WITH SUCH A CHILLY START
AND THE CANADIAN-SOURCE AIR MASS BUILDING IN YIELDING THICKNESSES AT
LEAST 30 M BELOW NORMAL... HIGHS SAT SHOULD ONLY BE IN THE 40-45
RANGE.
SAT NGT-MON: A LOT OF UNCERTAINTY IN THE DETAILS PERSISTS THIS
MORNING... HOWEVER IT`S LOOKING MORE LIKELY THAT WE`RE ENTERING INTO
A PERIOD OF MORE ACTIVE WEATHER DOMINATED BY SOUTHERN STREAM ENERGY
BUT WITH POTENTIAL INJECTIONS OF COOLER AIR FROM THE NORTHERN
STREAM. A NRN STREAM WAVE DROPPING SOUTHEAST FROM MT THROUGH THE
CENTRAL PLAINS WILL MERGE WITH SOUTHERN STREAM ENERGY EMANATING FROM
THE LOW OVER NRN MEX SAT NIGHT/SUN... BRINGING MID LEVEL DPVA INTO
NC SUN/SUN NIGHT. THE SHIFTING OF THE SURFACE HIGH ESE OFF THE COAST
WILL ALLOW A MOIST RETURN FLOW OFF THE GULF INTO THE GULF/MIDSOUTH
AND SOUTHEAST STATES... AS SURFACE LOW PRESSURE DEVELOPS ALONG THE
BAROCLINIC ZONE NEAR THE NW GULF COAST AND TRACKS NORTHEAST TOWARD
NC. THE GFS/ECMWF BRING PRECIP INTO WRN NC BY MIDDAY SUN... THEN
SPREAD IT EASTWARD THROUGH CENTRAL NC SUN NIGHT INTO EARLY MON
MORNING. BOTH THE GFS/ECMWF SHOW A MILLER TYPE-B CYCLOGENESIS
PATTERN BUT WITH VARIED LOW PLACEMENT... WITH THE ECMWF DEPICTING A
FURTHER-SOUTH TRIPLE POINT LOW TRACK VERSUS THE GFS. THE LATEST RUNS
SHOWS SUFFICIENTLY WARM LOW- AND MID-LEVEL THICKNESSES TO SUPPORT AN
ALL-RAIN EVENT... BUT GIVEN THIS PATTERN... WILL NEED TO WATCH MODEL
TRENDS CAREFULLY IN THE COMING DAYS. WITH OTHERWISE GOOD MODEL
AGREEMENT ON TIMING AND THE MID-LEVEL PATTERN... WILL BUMP UP
POPS... FOCUSING THE HIGHER CHANCES SUN AFTERNOON THROUGH SUN
NIGHT... TAPERING DOWN WEST-TO-EAST MON MORNING AS THE DAMPENING MID
LEVEL SHORTWAVE TROUGH SHIFTS EAST OVER THE MIDATLANTIC/ NORTHEAST
WITH SURFACE FRONTAL PASSAGE THROUGH NC. EXPECT IMPROVING WEATHER
LATE MON WITH ANOTHER CANADIAN HIGH CENTERED OVER THE MIDWEST
BUILDING INTO OUR AREA. EXPECT BELOW NORMAL TEMPS THROUGH SUN
NIGHT... WITH MORE UNCERTAINTY FOR HIGHS ON MON AS MUCH WILL DEPEND
ON WHETHER OR NOT WE GET INTO THE WARM SECTOR BEFORE FRONTAL
PASSAGE. WILL KEEP TEMPS BELOW NORMAL FOR NOW BUT IF MODEL WARMING
TRENDS HOLD... MAY NEED TO BUMP UP MON HIGHS QUITE A BIT IN LATER
FORECASTS. -GIH
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 645 AM TUESDAY...
24 HOUR TAF PERIOD: LIGHT SNOW OVERSPREADING NORTHEASTERN AREAS OF
THE CWA THIS MORNING. SNOW IS CURRENTLY MOVING OUT OF THE KRWI AREA
AND IS NOW CONFINED NORTH AND EAST. ELSEWHERE PRECIPITATION HAS
LARGELY ENDED OUTSIDE OF A FEW SNOW FLURRIES. WINDS ARE LIGHT AND
VARIABLE AT THIS HOUR BUT WILL BE PICKING BACK UP TO 5-10 KTS OUT OF
THE NORTHWEST THIS MORNING AND THEN GUSTING TO 20 KTS THIS
AFTERNOON. SOME MVFR CEILINGS STILL IN PLACE IN AREAS WHERE LIGHT
SNOW IS STILL FALLING. ELSEWHERE VFR CEILINGS ARE PREVAILING AND
SKIES WILL CONTINUE TO CLEAR AS THE DAY PROGRESSES WITH THE
EXCEPTION OF THE NORTHEASTERN AREAS WHERE CLOUDS WILL LINGER.
LONG TERM: THE NEXT THREAT TO AVIATION CONDITIONS WILL BE THURSDAY
NIGHT INTO FRIDAY MORNING AS A FRONTAL SYSTEM CROSSES THE AREA AND
THEN ANOTHER SYSTEM SUNDAY INTO MONDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...ELLIS
SHORT TERM...HARTFIELD
LONG TERM...HARTFIELD
AVIATION...ELLIS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
241 AM EST TUE JAN 27 2015
.SYNOPSIS...STRONG LOW PRESSURE OFF NEW ENGLAND THIS MORNING WILL
LIFT NORTHEAST AWAY FROM OUR AREA TODAY. HIGH PRESSURE WILL BUILD IN
FROM THE NORTHWEST THIS AFTERNOON THROUGH EARLY THURSDAY. ANOTHER
CLIPPER LOW PRESSURE SYSTEM WILL SWING BY JUST TO OUR NORTH LATE
THURSDAY THROUGH THURSDAY NIGHT... THEN HIGH PRESSURE WILL AGAIN
BUILD INTO OUR AREA FROM THE NORTHWEST ON FRIDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY NIGHT/...
AS OF 240 AM TUESDAY...
TODAY AND TONIGHT: FRONTAL SYSTEM IS CURRENTLY MOVING THROUGH THE
AREA AS LOW PRESSURE CONTINUES TO DEEPEN ACROSS THE DELMARVA. THE
CWA IS CURRENTLY SPLIT BETWEEN DRIER AIR TO THE WEST OF ROUTE 1 AND
MORE MOISTURE TO THE EAST. A BAND OF PRECIPITATION HAS SET UP ALONG
WHAT APPEARS TO BE THE FRONTAL BOUNDARY AND HAS BROUGHT SOME
SCATTERED REPORTS OF A RAIN/SNOW MIX FROM PERSON COUNTY DOWN THROUGH
WAKE COUNTY WITH MOSTLY RAIN OR DRIZZLE SOUTH OF THERE. THIS BAND
WILL MOVE GRADUALLY EASTWARD THROUGH THE EARLY MORNING HOURS TOWARDS
TEH I-95 CORRIDOR AND THE EASTERN TIER OF COUNTIES. SCATTERED
REPORTS OF LIGHT SNOW OR RAIN WILL CONTINUE THROUGH THE MORNING
BEFORE MOST LOCALES DRY OUT. THE THREAT FOR SNOW SHOULD END AFTER
12Z AS RAP FORECAST SOUNDINGS INDICATE SIGNIFICANT DRYING IN THE
SNOW GROWTH ZONE. NO ACCUMULATION IS EXPECTED OR ANY IMPACTS FROM
THE SNOW ASIDE FROM A POTENTIAL DUSTING ON ELEVATED SURFACES AT BEST
AS SOIL TEMPERATURES ARE STILL NEAR 40 DEGREES.
THIS SETUP HAS ALSO CAUSED A SPLIT IN CLOUD COVER WITH AREAS UNDER
AND EAST OF THE PRECIPITATION BAND EXPERIENCING MAINLY MVFR CEILINGS
WITH VFR CONDITIONS BACK TO THE WEST. A FEW WIND GUSTS STILL OUT
THERE UP TO 20 KTS OR SO OUT OF THE NORTHWEST. GUSTS MAY DIE OFF
TOWARDS SUNRISE BUT WILL PICK UP AGAIN LATER THIS AFTERNOON.
TEMPERATURES THIS AFTERNOON IN THE LOW TO MID 40S NE TO SW AS CLOUDS
LINGER LONGER AND COLD AIR ADVECTION IS MORE PRONOUNCED IN THE
NORTHEAST. EXPECT DRYING TO CONTINUE INTO TONIGHT WITH CLEARING
SKIES BUT WINDS REMAINING 5-10 KTS SO NOT EXACTLY GREAT FOR
RADIATIONAL COOLING BUT TEMPS WILL STILL MANAGE TO DROP INTO THE
MIDDLE 20S WITH THE CHANGE IN AIRMASS.
WEDNESDAY AND WEDNESDAY NIGHT: A DRY DAY EXPECTED FOR WEDNESDAY AS
CENTRAL NC IS SANDWICHED BETWEEN THE EXITING BLIZZARD TO THE
NORTHEAST AND INCOMING HIGH PRESSURE TO THE NORTHWEST. SURFACE
PRESSURE GRADIENT WILL RELAX A LITTLE BUT STILL A GOOD COLD AIR
ADVECTION REGIME BOTH AT THE SURFACE AND ALOFT ON THE BACK SIDE OF
THE UPPER LEVEL TROUGH. THIS WILL KEEP TEMPS DOWN IN THE LOW TO MID
40S...ABOUT 10 DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. WINDS 5-
10 KTS OUT OF THE NORTH VEERING TO NORTHEASTERLY LATER IN THE DAY.
CLOUDS WILL GRADUALLY INCREASE IN THE NORTHWEST ON WEDNESDAY NIGHT
AS THE NEXT LOW PRESSURE SYSTEM MOVES INTO THE OHIO VALLEY. THIS
WILL HELP TO KEEP LOW TEMPERATURES UP IN THE TRIAD. GENERALLY MID
20S BUT POSSIBLY SOME LOWER 20S IN OUR EASTERN NORMALLY COLD ZONES.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
AS OF 200 AM TUESDAY...
THU/THU NIGHT: THE GREAT LAKES SHORTWAVE TROUGH WILL TRACK ESE THEN
EASTWARD ACROSS THE NORTHEAST/MIDATLANTIC STATES... TRACKING THROUGH
THE BASE OF THE POLAR LOW OVER HUDSON BAY... WHILE ITS CORRESPONDING
SURFACE LOW CROSSES THE OH VALLEY AND MIDATLANTIC COAST. AFTER A
CHILLY MORNING WITH THE SURFACE RIDGE OVERHEAD... INCREASING
SOUTHERLY LOW LEVEL FLOW AS THE HIGH SHIFTS SSE WILL ALLOW FOR A
MODEST RECOVERY IN THICKNESSES... BUT STILL BELOW NORMAL... AND THE
TEMP RISE WILL BE HINDERED BY THICKENING AND LOWERING CLOUDS WITH
APPROACHING WEAK MID LEVEL DPVA AND LOW LEVEL FRONTAL ZONE. BUT
MODELS STILL SHOW PW VALUES JUST BARELY REACHING ABOVE NORMAL... AND
GFS/NAM BUFR FORECAST SOUNDINGS SHOW A DRY SUBCLOUD LAYER BELOW 850
MB THROUGH THU. MODEL QPF IS ALSO SCANT WITH THE GFS/NAM/SREF MEAN
STAYING DRY OVER CENTRAL NC THROUGH THU NIGHT. AFTER 00Z THE COLUMN
STARTS TO DRY OUT ALOFT BEHIND THE 700 MB TROUGH... AND JUST AHEAD
OF THE SURFACE FRONT WHICH IS EXPECTED TO SWEEP EAST THROUGH CENTRAL
NC AFTER MIDNIGHT. WILL TRIM BACK EXISTING SLIGHT CHANCE POPS A
BIT... FOCUSING THEM LATE THU AFTERNOON UNTIL SHORTLY AFTER
MIDNIGHT... HOWEVER AM RELUCTANT TO REMOVE THEM ENTIRELY AS THE
ECMWF CONTINUES TO GENERATE LIGHT PRECIP LATE THU AFTERNOON AND THU
EVENING. EXPECT HIGHS THU IN THE MID 40S TO AROUND 50. LOWS THU
NIGHT 32-38.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 200 AM TUESDAY...
FRI-SAT: THE MID LEVEL TROUGH AXIS WILL BE SWINGING TO OUR EAST FRI
MORNING WITH THE SURFACE COLD FRONT PUSHING OFF THE NC COAST. NW LOW
LEVEL FLOW WILL BRING IN COOLER AIR AS HIGH PRESSURE INITIALLY
CENTERED OVER NRN MINN DRIFTS SOUTHEAST... BUILDING INTO AND OVER
THE MIDATLANTIC THROUGH VA/ERN NC THROUGH SAT. SHOULD SEE MOSTLY
CLEAR SKIES FRI/FRI NIGHT... FOLLOWED BY INCREASING HIGH THIN CLOUDS
SAT AS WE START TO SEE INITIAL ENERGY EJECTING FROM THE DESERT SW
LOW TRACK EASTWARD WITHIN CONFLUENT NW MID LEVEL FLOW. WITH FALLING
THICKNESSES FRI... EXPECT BELOW-NORMAL HIGHS IN THE MID 40S TO LOWER
50S. LOWS FRI NIGHT IN THE MID 20S... THEN WITH SUCH A CHILLY START
AND THE CANADIAN-SOURCE AIR MASS BUILDING IN YIELDING THICKNESSES AT
LEAST 30 M BELOW NORMAL... HIGHS SAT SHOULD ONLY BE IN THE 40-45
RANGE.
SAT NGT-MON: A LOT OF UNCERTAINTY IN THE DETAILS PERSISTS THIS
MORNING... HOWEVER IT`S LOOKING MORE LIKELY THAT WE`RE ENTERING INTO
A PERIOD OF MORE ACTIVE WEATHER DOMINATED BY SOUTHERN STREAM ENERGY
BUT WITH POTENTIAL INJECTIONS OF COOLER AIR FROM THE NORTHERN
STREAM. A NRN STREAM WAVE DROPPING SOUTHEAST FROM MT THROUGH THE
CENTRAL PLAINS WILL MERGE WITH SOUTHERN STREAM ENERGY EMANATING FROM
THE LOW OVER NRN MEX SAT NIGHT/SUN... BRINGING MID LEVEL DPVA INTO
NC SUN/SUN NIGHT. THE SHIFTING OF THE SURFACE HIGH ESE OFF THE COAST
WILL ALLOW A MOIST RETURN FLOW OFF THE GULF INTO THE GULF/MIDSOUTH
AND SOUTHEAST STATES... AS SURFACE LOW PRESSURE DEVELOPS ALONG THE
BAROCLINIC ZONE NEAR THE NW GULF COAST AND TRACKS NORTHEAST TOWARD
NC. THE GFS/ECMWF BRING PRECIP INTO WRN NC BY MIDDAY SUN... THEN
SPREAD IT EASTWARD THROUGH CENTRAL NC SUN NIGHT INTO EARLY MON
MORNING. BOTH THE GFS/ECMWF SHOW A MILLER TYPE-B CYCLOGENESIS
PATTERN BUT WITH VARIED LOW PLACEMENT... WITH THE ECMWF DEPICTING A
FURTHER-SOUTH TRIPLE POINT LOW TRACK VERSUS THE GFS. THE LATEST RUNS
SHOWS SUFFICIENTLY WARM LOW- AND MID-LEVEL THICKNESSES TO SUPPORT AN
ALL-RAIN EVENT... BUT GIVEN THIS PATTERN... WILL NEED TO WATCH MODEL
TRENDS CAREFULLY IN THE COMING DAYS. WITH OTHERWISE GOOD MODEL
AGREEMENT ON TIMING AND THE MID-LEVEL PATTERN... WILL BUMP UP
POPS... FOCUSING THE HIGHER CHANCES SUN AFTERNOON THROUGH SUN
NIGHT... TAPERING DOWN WEST-TO-EAST MON MORNING AS THE DAMPENING MID
LEVEL SHORTWAVE TROUGH SHIFTS EAST OVER THE MIDATLANTIC/ NORTHEAST
WITH SURFACE FRONTAL PASSAGE THROUGH NC. EXPECT IMPROVING WEATHER
LATE MON WITH ANOTHER CANADIAN HIGH CENTERED OVER THE MIDWEST
BUILDING INTO OUR AREA. EXPECT BELOW NORMAL TEMPS THROUGH SUN
NIGHT... WITH MORE UNCERTAINTY FOR HIGHS ON MON AS MUCH WILL DEPEND
ON WHETHER OR NOT WE GET INTO THE WARM SECTOR BEFORE FRONTAL
PASSAGE. WILL KEEP TEMPS BELOW NORMAL FOR NOW BUT IF MODEL WARMING
TRENDS HOLD... MAY NEED TO BUMP UP MON HIGHS QUITE A BIT IN LATER
FORECASTS. -GIH
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 100 AM TUESDAY...
24 HOUR TAF PERIOD: CONDITIONS AT THIS HOUR ARE GENERALLY SPLIT
BETWEEN VFR IN THE WEST WHERE IT IS CONSIDERABLY DRIER AND MVFR IN
THE EAST WHERE MORE MOISTURE IS PRESENT IN THE LOWER LEVELS. MVFR
CONDITIONS ARE DUE TO LOWER CEILINGS WITH VISIBILITIES EVERYWHERE
COMING IN AT 10 SM. THERE CONTINUE TO BE A FEW WIND GUSTS OUT THERE
UP TO 20 KTS...PARTICULARLY IN THE NORTHEAST WHICH MAKES SINCE AS
THE PRESSURE GRADIENT THERE INCREASES CLOSER TO THE LOW OFFSHORE.
WINDS ARE GENERALLY OUT OF THE NORTHWEST AND WILL STAY THAT WAY
THROUGH THE TAF PERIOD. GUSTS ARE EXPECTED TO RELAX AFTER 9Z. AS
DRIER AIR CONTINUES TO WORK IN FROM THE WEST CONDITIONS WILL IMPROVE
BACK TO VFR AND REMAIN THERE THROUGH THE PERIOD. GUSTS OF 15-20 KTS
WILL BE PREVALENT AGAIN LATER IN THE AFTERNOON. THERE IS A CHANCE
FOR A LINGERING RAIN SHOWER OR EVEN A FEW SNOW FLURRIES AS WE
CONTINUE THROUGH THE MORNING WITH THE MOST LIKELY LOCATION BEING THE
NORTHEAST. ONE OTHER NOTE...PILOT REPORTS HAVE BEEN COMING IN AROUND
KRDU AND POINTS NORTH FOR LIGHT TO MODERATE ICING FROM 4-12 KFT.
LONG TERM: THE NEXT THREAT TO AVIATION CONDITIONS WILL BE THURSDAY
NIGHT INTO FRIDAY MORNING AS A FRONTAL SYSTEM CROSSES THE AREA AND
THEN ANOTHER SYSTEM SUNDAY INTO MONDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...ELLIS
SHORT TERM...HARTFIELD
LONG TERM...HARTFIELD
AVIATION...ELLIS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
317 AM CST TUE JAN 27 2015
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 315 AM CST TUE JAN 27 2015
FORECAST CHALLENGE CONCERNS TEMPERATURES AND MIDWEEK SNOW CHANCES.
MODELS IN REASONABLE AGREEMENT AND WILL USE MODEL BLEND.
MAIN CHALLENGE TODAY WILL BE TEMPERATURES WHICH WILL HINGE ON WHAT
CURRENT CLOUD COVER DOES DURING THE DAY. CURRENT STRATUS CLOUD
SHIELD EXTENDS FROM VALLEY EASTWARD. MODELS CURRENTLY NOT HANDLING
CLOUD TRENDS WELL AT ALL AND HAVE DIFFERENT SOLUTIONS ON WHAT CLOUDS
WILL DO. HIGH RESOLUTION (HRRR) WAY TOO FAR WEST WITH LOWER CIGS
WHILE MOST OTHER MODELS TOO QUICK IN PUSHING LOW LEVEL MOIST
EASTWARD. GFS AND TO A DEGREE THE NAM WANT TO CLEAR OUT THE VALLEY
AND DEVELOP LOWER CIGS WEST OF THE VALLEY THIS AFTERNOON. AS LOW
LEVEL FLOW STRENGTHENS FROM THE S-SW DURING THE AFTERNOON ALONG
WITH INCREASING WARM ADVECTION WESTERN EDGE SHOULD ERODE BUT MAY
BE TOO LATE FOR SOLAR TO AID IN WARMING. WITH UNCERTAINTY DID NOT
DIFFER TOO MUCH ON MAXIMUM TEMPERATURES.
REGION REMAINS IN WARM SECTOR OVERNIGHT FOR ANOTHER MILD NIGHT.
COLDER AIR BEGINS TO SAG INTO THE FA WEDNESDAY. DURING THE DAY
MODELS SLOWER IN BRINGING PCPN INTO THE FA AND KEEP MOST
APPRECIABLE QPF NORTH OF THE BORDER. WITH MODELS TRENDING FOR
LIGHTER AMOUNTS OF PCPN AND DELAY IN BRINGING MOISTURE SOUTH OF
INL BORDER DELAYED/TRIMMED POPS DURING THE AM AND HELD WITH CHANCE
POPS DURING THE DAY AS ECMWF AND NAM NEARLY DRY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 315 AM CST TUE JAN 27 2015
MORE FAVORABLE UPPER SUPPORT MOVES INTO THE REGION LATER WEDNESDAY
SO MAINTAINED HIGHER POPS AND DECREASED POPS FROM WEST TO EAST
AFTER MIDNIGHT AS WAVE PUSHES EAST.
TEMPERATURES TREND COLDER TO FINISH OFF THE WORK WEEK BUT STILL ON THE
WARM SIDE OF SEASONAL AVERAGES.
UPPER LEVEL PATTERN CONTINUES WITH NW FLOW ALOFT...BEFORE AN UPPER
LEVEL TROF SAGS OVER THE AREA BY THE WEEKEND. SFC HIGH PRESSURE OVER
THE REGION WILL SHIFT SE ON FRIDAY AHEAD OF A DEVELOPING CLIPPER
SYSTEM. THIS SYSTEM WILL BRING ANOTHER CHANCE FOR LIGHT
PRECIPITATION...AND USHER IN COOLER TEMPERATURES FOR THE AREA
THROUGH THE REST OF THE PERIOD. OTHERWISE...NO MAJOR SYSTEMS
EXPECTED AND THE OVERALL WEATHER PATTERN WILL REMAIN QUIET.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1130 PM CST MON JAN 26 2015
FAR AND DVL COULD SEE SOME BR OR FG OVERNIGHT TONIGHT WHILE THE
WINDS ARE CALM. WILL SEE SOME IMPROVEMENT IN THE MORNING AS SE FLOW
PICKS UP. FOR NORTHWEST AND W CNTRL MN...CLOUDY SKIES SHOULD
INHIBIT VSBYS FROM FALLING TOO DRASTICALLY BUT CIGS HAVE DROPPED
INTO IFR RANGE AND 06Z TAFS WILL REFLECT THIS. THE HRRR DOES KEEP
THE IFR CONDS IN FOR MUCH OF MUCH OF THE DAY TOMORROW...HOWEVER
WITH INCREASING SE FLOW THINK WE WILL SEE IMPROVED CONDS BY LATE MORNING.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...VOELKER
LONG TERM...HOPKINS/VOELKER
AVIATION...SPEICHER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1039 PM EST WED JAN 28 2015
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFF TO THE SOUTHEAST OF THE REGION
TONIGHT...FOLLOWED BY AN ALBERTA CLIPPER WHICH WILL CROSS THE
AREA THURSDAY AND THURSDAY NIGHT. HIGH PRESSURE WILL RETURN FOR
LATE FRIDAY INTO SATURDAY. A NEW STORM MAY BRING A ROUND OF WINTRY
WEATHER FOR LATER SUNDAY INTO MONDAY...BEFORE ANOTHER SURGE OF
COLD AIR WORKS INTO THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
CLEAR SKIES...LIGHT WIND AND FRESH SNOW COVER ALLOWING TEMPS TO
FALL QUICKLY THIS EVENING. MESONET SHOWS SOME SUB-ZERO READINGS ALREADY
SHOWING UP ACROSS THE N MTNS AS OF 03Z. BASED ON AFTERNOON DWPTS
AND LATEST RAP OUTPUT...EXPECT THE COLDER VALLEYS OF THE
ALLEGHENIES TO BOTTOM OUT BTWN ZERO AND 10BLW AFTER MIDNIGHT.
UNDER SUCH AN IDEAL RAD COOLING SCENARIO...EXPECT WIDELY VARYING
MIN TEMPS...WITH 15F DIFFERENCES LIKELY WITHIN THE SAME
TOWNSHIPS. HAVE TRIED TO SETTLE ON AVG LOWS...WHICH WILL LKLY
RANGE FROM ARND ZERO ACROSS THE NW MTNS...TO ARND 10 ABV ACROSS
THE LOWER SUSQ VALLEY. WAA ALOFT AND ASSOC CIRRUS SHIELD WILL
LIKELY OVERSPREAD THE AREA FROM THE WEST TOWARD DAWN...RESULTING
IN RISING TEMPS LATE ACROSS THE WESTERN HALF OF THE STATE.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
CLOUDS WILL THICKEN QUICKLY THURSDAY WITH WARM ADVECTION PRECIP
OVERSPREADING THE AREA DURING THE AFTERNOON. WE HAVE OPTED FOR A
LOW END ADVISORY FOR OUR WESTERN HIGHER ELEVATION COUNTIES FOR THE
POTENTIAL OF SEVERAL INCHES OF SNOW...WITH THE POSSIBILITY OF A
BRIEF PERIOD OF FREEZING RAIN AT THE ONSET.
MODELS ALL AGREE IN SHOVING A WEDGE OF WARM AIR ALOFT INTO THE
AREA THURSDAY MORNING...BUT FORECAST SOUNDINGS SHOW THE COLUMN
COOLING QUICKLY ONCE PRECIP STARTS SO THE THREAT FOR SIG ICING
WILL BE PRETTY SMALL. THINKING IS THAT A GENERAL 2-4INCH SNOWFALL
IS LIKELY OVER THE RIDGE COUNTIES...WITH A COATING TO PERHAPS AS
MUCH AS 3 INCHES FROM CENTRAL AREAS EASTWARD BEFORE THINGS WIND
DOWN THURSDAY NIGHT OR FRIDAY.
HIGHS THURSDAY WILL MAKE TO THE UPPER 20S TO AROUND FREEZING IN
THE BRISK SW FLOW AHEAD OF THE CLIPPER/ARCTIC FRONT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
A STRONG SHOT OF WAA ALOFT AND MODERATELY STG UPPER LEVEL
DIVERGENCE ASSOCIATED WITH THE RIGHT ENTRANCE REGION OF AN
UPPER LVL JET MAX ACROSS SRN ONTARIO WILL LEAD TO PERIODS OF
LIGHT /TO BRIEFLY MDT SNOW/ FOCUSED ACROSS THE NW HALF OF THE
STATE LATER THU AFT INTO THURSDAY NIGHT. SOME FREEZING RAIN
COULD MIX IN EARLY...BUT UPWARD MOTION OFFSETS THE WARMING.
FCST TEMPS AT BUF COOLER NOW THAN YESTERDAY. THUS THINK MOST
OF OUR AREA WILL STAY MAINLY BELOW 32 ON THU. SOURCE REGION
OF THE AIRMASS IS FROM THE PLAINS. IT WAS IN THE 70S AND LOWER
80S ACROSS THE SOUTHERN PLAINS YESTERDAY...WARM THERE TODAY TOO.
SNOW WILL LINGER INTO EARLY FRIDAY...AS THE MAIN COLD FRONT DROPS
SE. IT WILL BE WINDY ON FRIDAY.
FRIDAY NIGHT WILL BE COLD...AS SKIES CLEAR AND WINDS DIE DOWN.
A BRIGHT DAY ON SAT...BUT NOT REAL WARM.
STILL HAVE CHC POPS ON SUNDAY. A LOT OF SPREAD IN THE MODEL OUTPUT
THE LAST FEW DAYS. 12Z MODELS BACKING OFF SOME NOW. PATTERN
SUPPORTS LOW PRESSURE SYSTEMS THAT ARE FAST MOVING AND WEAK. WOULD
STILL EXPECT SOME LIGHT SNOW INTO MONDAY MORNING.
A COLD NIGHT MONDAY NIGHT...AS THE NEXT HIGH BUILDS INTO
THE AREA.
SOME HINTS AT ANOTHER FAST MOVING LOW FOR MID WEEK...FOR NOW
WENT WITH CHC POPS.
MINOR CHANGES TO THE PACKAGE MADE.
&&
.AVIATION /04Z THURSDAY THROUGH MONDAY/...
HIGH PRESSURE WILL MOVE EAST ACROSS THE STATE OVERNIGHT....BRINGING
WIDESPREAD VFR CONDITIONS.
THURSDAY WILL BRING INCREASING CLOUDINESS WITH CONDITIONS
DETERIORATING IN SNOW STARTING AROUND MID DAY OVER WESTERN
TERMINALS...SPREADING RAPIDLY EAST THROUGH MID AFTERNOON.
REDUCED CONDITIONS WILL CONTINUE INTO EARLY FRIDAY.
OUTLOOK...
FRI...CONDITIONS IMPROVING DURING THE DAY...BUT REMAINING MVFR
OVER THE HIGHER ELEVATION TERMINALS OF THE WEST AND NORTH.
SAT...VFR.
SUN...RESTRICTIONS DEVELOPING WITH SNOW OVERSPREADING FROM THE
WEST.
MON...REDUCED CONDS EARLY IN SNOW. IMPROVING FROM WEST TO EAST
AFTERNOON ONWARD.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 11 AM THURSDAY TO 7 AM EST FRIDAY
FOR PAZ004>006-010-011-017-024-033.
&&
$$
SYNOPSIS...FITZGERALD/LA CORTE
NEAR TERM...FITZGERALD
SHORT TERM...LA CORTE
LONG TERM...MARTIN
AVIATION...LA CORTE/GARTNER
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1045 AM CST TUE JAN 27 2015
.UPDATE...
ISSUED AT 1040 AM CST TUE JAN 27 2015
HAVE UPDATED THE FORECAST FOR THIS MORNING TO ISSUE A DENSE FOG
ADVISORY. SOUTHEAST FLOW ACROSS THE AREA MAKING IT DIFFICULT FOR
STRATUS TO ERODE ACROSS THE AREA. WINDS EXPECTED TO INCREASE
THROUGHOUT THE DAY...BUT STILL MAY NOT BE ENOUGH TO SCOUR OUT THE
CLOUDS. HAVE LOWERED FORECAST HIGHS FOR TODAY...ESPECIALLY IN THE
EAST.
FOR TONIGHT...NAM SHOWS THE STRATUS THICKENING WHILE THE RAP SHOWS
THE STRATUS THINNING AS WINDS INCREASE. IF THE STRATUS GETS THICK
ENOUGH...MAY NEED TO CONSIDER DRIZZLE BUT WILL TAKE A LOOK AT THAT
FOR THE AFTERNOON PACKAGE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 257 AM CST TUE JAN 27 2015
ONLY AREA OF STRATUS VERY EARLY THIS MORNING IS SITUATED THROUGH
PORTIONS OF SOUTHWESTERN MINNESOTA INTO THE IOWA GREAT LAKES
AREA...WITH SOME PATCHY FOG LOCATED WITHIN THIS NARROW BAND. BOTH
THE RAP AND SREF ARE HANDLING THESE LOW CLOUDS/REDUCED VISIBILITY
WELL...AND HAVE IT DISSIPATING BY 15Z. OTHERWISE...THE REMAINDER OF
THE CWA REMAINS FOG FREE THIS MORNING SO REMOVED MOST OF THE FOG
FROM THE FORECAST. HIGH PRESSURE SITUATED ACROSS THE REGION THIS
MORNING WILL PUSH OFF TO THE EAST THROUGH THE DAY...AND AS IT DOES
SO THE LOW LEVEL FLOW WILL BECOME SOUTHEASTERLY. THIS AND A
STRENGTHENING INVERSION WILL INHIBIT MIXING TODAY...ESPECIALLY IN
THE EAST...AND IN RESPONSE HIGH TEMPERATURES WILL GENERALLY BE
COOLER THAN YESTERDAY. STILL VERY MILD FOR THIS TIME OF YEAR
HOWEVER...TOPPING OUT IN THE LOWER 40S THROUGH SOUTHWESTERN
MINNESOTA INTO THE EASTERN PORTIONS OF OUR IOWA ZONES...TO 50S
THROUGH THE JAMES RIVER VALLEY THROUGH THE LOWER MISSOURI RIVER
CORRIDOR.
A SURFACE TROUGH BEGINS TO APPROACH FROM THE WEST TONIGHT...AND IT
WILL BE A MILDER NIGHT WITH INCREASING WARM AIR ADVECTION OUT AHEAD
OF THE SYSTEM. WITH THAT...LOOKING AT LOWS GENERALLY LOWER TO MID
30S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 257 AM CST TUE JAN 27 2015
WEDNESDAY STILL TO BE THE FINAL VERY MILD DAY AS LOW PRESSURE PASSES
AND COOLER AIR BEGINS TO DRAIN SOUTHWARD. MODELS SIMILAR TO
YESTERDAY SO NO REAL CHANGES. STILL MAINTAIN A SMALL CHANCE FOR
LIGHT SNOW IN THE NORTH AS A WAVE PASSES BY BUT A BIT MOISTURE
STARVED SO NOT ANTICIPATING MUCH OF ANYTHING.
BECOMING A BIT WINDY LATE WEDNESDAY AFTERNOON AND NIGHT AS COLD AIR
ADVECTION AND A STRONG PRESSURE GRADIENT WORK TO MIX DOWN SOME
STRONG WINDS ALOFT. LIKELY SEE SOME WIND GUSTS OF 35 MPH OR SO
WEDNESDAY NIGHT. WITH SOME CLOUD COVER AND WIND TEMPERATURES SHOULD
STAY FAIRLY MILD FOR THIS TIME OF YEAR WITH THURSDAY MORNING LOWS
FROM THE MID 20S TO LOWER 30S.
THURSDAY STILL A BIT BREEZY AND DEFINITELY COLDER. THE LOWER LEVEL
THERMAL FIELD HAS COME IN A BIT COLDER THIS TIME AROUND WHICH IS
ALSO FAIRLY WELL AGREED UPON SO WENT AHEAD AND LOWERED HIGHS A
COUPLE OF DEGREES. HIGHS MAINLY UPPER 20S TO MID 30S.
IN THE OUTER PERIODS (FRIDAY THROUGH MONDAY)...THE COLDER PATTERN
SETTLES IN AND REMAINS IN PLACE. MODELS ALL IN PRETTY GOOD AGREEMENT
THIS TIME AROUND SO WILL KEEP TEMPERATURES ON THE COLDER SIDE OF
GUIDANCE. FRIDAY IS THE LAST OF THE MILD DAYS AS SOUTHERLY FLOW
KEEPS 925MB TEMPERATURES CLOSER TO ZERO. SATURDAY LIKELY POSING THE
POTENTIAL FOR THE BIGGEST ERROR IN FORECASTING AS THE ARCTIC
BOUNDARY IS PROGGED TO MOVE THROUGH. A LITTLE FASTER AND HIGHS WILL
BE IN THE 20S...A LITTLE SLOWER AND HIGH WOULD BE IN THE 40S SO
UPPER 20S IN THE NORTH AND MID 30S IN THE SOUTH SEEMS LIKE A GOOD
HEDGE TOWARDS THIS FAIRLY SHARP THERMAL GRADIENT. WILL ALSO HAVE A
CHANCE FOR LIGHT SNOW ON SATURDAY AND SATURDAY NIGHT AS THIS COLD
AIR SURGES SOUTH. SUNDAY AND MONDAY WELL INTO THE COLD AIR SO JUST
LOOKING AT HIGHS IN THE TEENS TO LOWER 20S AND LOWS IN THE SINGLE
DIGITS TO LOWER TEENS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1040 AM CST TUE JAN 27 2015
HAVE AMENDED TAFS AT KFSD THIS MORNING TO KEEP LOW CLOUDS AND FOG
THROUGH EARLY AFTERNOON. ELSEWHERE...INCREASING SOUTHEASTERLY
WINDS ARE EXPECTED TODAY INTO TONIGHT. QUESTIONS REMAIN HOW LONG
STRATUS WILL HANG TOUGH...ESPECIALLY ACROSS SOUTHWEST MINNESOTA.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...DENSE FOG ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR SDZ040-056-
062-067.
MN...DENSE FOG ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR MNZ071-072-
080-089-097-098.
IA...DENSE FOG ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR IAZ001-002-
012-013.
NE...NONE.
&&
$$
UPDATE...
SHORT TERM...JM
LONG TERM...08
AVIATION...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
508 AM CST TUE JAN 27 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 257 AM CST TUE JAN 27 2015
ONLY AREA OF STRATUS VERY EARLY THIS MORNING IS SITUATED THROUGH
PORTIONS OF SOUTHWESTERN MINNESOTA INTO THE IOWA GREAT LAKES
AREA...WITH SOME PATCHY FOG LOCATED WITHIN THIS NARROW BAND. BOTH
THE RAP AND SREF ARE HANDLING THESE LOW CLOUDS/REDUCED VISIBILITY
WELL...AND HAVE IT DISSIPATING BY 15Z. OTHERWISE...THE REMAINDER OF
THE CWA REMAINS FOG FREE THIS MORNING SO REMOVED MOST OF THE FOG
FROM THE FORECAST. HIGH PRESSURE SITUATED ACROSS THE REGION THIS
MORNING WILL PUSH OFF TO THE EAST THROUGH THE DAY...AND AS IT DOES
SO THE LOW LEVEL FLOW WILL BECOME SOUTHEASTERLY. THIS AND A
STRENGTHENING INVERSION WILL INHIBIT MIXING TODAY...ESPECIALLY IN
THE EAST...AND IN RESPONSE HIGH TEMPERATURES WILL GENERALLY BE
COOLER THAN YESTERDAY. STILL VERY MILD FOR THIS TIME OF YEAR
HOWEVER...TOPPING OUT IN THE LOWER 40S THROUGH SOUTHWESTERN
MINNESOTA INTO THE EASTERN PORTIONS OF OUR IOWA ZONES...TO 50S
THROUGH THE JAMES RIVER VALLEY THROUGH THE LOWER MISSOURI RIVER
CORRIDOR.
A SURFACE TROUGH BEGINS TO APPROACH FROM THE WEST TONIGHT...AND IT
WILL BE A MILDER NIGHT WITH INCREASING WARM AIR ADVECTION OUT AHEAD
OF THE SYSTEM. WITH THAT...LOOKING AT LOWS GENERALLY LOWER TO MID
30S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 257 AM CST TUE JAN 27 2015
WEDNESDAY STILL TO BE THE FINAL VERY MILD DAY AS LOW PRESSURE PASSES
AND COOLER AIR BEGINS TO DRAIN SOUTHWARD. MODELS SIMILAR TO
YESTERDAY SO NO REAL CHANGES. STILL MAINTAIN A SMALL CHANCE FOR
LIGHT SNOW IN THE NORTH AS A WAVE PASSES BY BUT A BIT MOISTURE
STARVED SO NOT ANTICIPATING MUCH OF ANYTHING.
BECOMING A BIT WINDY LATE WEDNESDAY AFTERNOON AND NIGHT AS COLD AIR
ADVECTION AND A STRONG PRESSURE GRADIENT WORK TO MIX DOWN SOME
STRONG WINDS ALOFT. LIKELY SEE SOME WIND GUSTS OF 35 MPH OR SO
WEDNESDAY NIGHT. WITH SOME CLOUD COVER AND WIND TEMPERATURES SHOULD
STAY FAIRLY MILD FOR THIS TIME OF YEAR WITH THURSDAY MORNING LOWS
FROM THE MID 20S TO LOWER 30S.
THURSDAY STILL A BIT BREEZY AND DEFINITELY COLDER. THE LOWER LEVEL
THERMAL FIELD HAS COME IN A BIT COLDER THIS TIME AROUND WHICH IS
ALSO FAIRLY WELL AGREED UPON SO WENT AHEAD AND LOWERED HIGHS A
COUPLE OF DEGREES. HIGHS MAINLY UPPER 20S TO MID 30S.
IN THE OUTER PERIODS (FRIDAY THROUGH MONDAY)...THE COLDER PATTERN
SETTLES IN AND REMAINS IN PLACE. MODELS ALL IN PRETTY GOOD AGREEMENT
THIS TIME AROUND SO WILL KEEP TEMPERATURES ON THE COLDER SIDE OF
GUIDANCE. FRIDAY IS THE LAST OF THE MILD DAYS AS SOUTHERLY FLOW
KEEPS 925MB TEMPERATURES CLOSER TO ZERO. SATURDAY LIKELY POSING THE
POTENTIAL FOR THE BIGGEST ERROR IN FORECASTING AS THE ARCTIC
BOUNDARY IS PROGGED TO MOVE THROUGH. A LITTLE FASTER AND HIGHS WILL
BE IN THE 20S...A LITTLE SLOWER AND HIGH WOULD BE IN THE 40S SO
UPPER 20S IN THE NORTH AND MID 30S IN THE SOUTH SEEMS LIKE A GOOD
HEDGE TOWARDS THIS FAIRLY SHARP THERMAL GRADIENT. WILL ALSO HAVE A
CHANCE FOR LIGHT SNOW ON SATURDAY AND SATURDAY NIGHT AS THIS COLD
AIR SURGES SOUTH. SUNDAY AND MONDAY WELL INTO THE COLD AIR SO JUST
LOOKING AT HIGHS IN THE TEENS TO LOWER 20S AND LOWS IN THE SINGLE
DIGITS TO LOWER TEENS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 505 AM CST TUE JAN 27 2015
WILL HAVE AREAS OF LIFR TO MVFR CIGS/VISBYS EAST OF INTERSTATE 29
THROUGH 15Z. OTHERWISE...VFR CONDITIONS THROUGH THE TAF PERIOD.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...JM
LONG TERM...08
AVIATION...JM
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
258 AM CST TUE JAN 27 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 257 AM CST TUE JAN 27 2015
ONLY AREA OF STRATUS VERY EARLY THIS MORNING IS SITUATED THROUGH
PORTIONS OF SOUTHWESTERN MINNESOTA INTO THE IOWA GREAT LAKES
AREA...WITH SOME PATCHY FOG LOCATED WITHIN THIS NARROW BAND. BOTH
THE RAP AND SREF ARE HANDLING THESE LOW CLOUDS/REDUCED VISIBILITY
WELL...AND HAVE IT DISSIPATING BY 15Z. OTHERWISE...THE REMAINDER OF
THE CWA REMAINS FOG FREE THIS MORNING SO REMOVED MOST OF THE FOG
FROM THE FORECAST. HIGH PRESSURE SITUATED ACROSS THE REGION THIS
MORNING WILL PUSH OFF TO THE EAST THROUGH THE DAY...AND AS IT DOES
SO THE LOW LEVEL FLOW WILL BECOME SOUTHEASTERLY. THIS AND A
STRENGTHENING INVERSION WILL INHIBIT MIXING TODAY...ESPECIALLY IN
THE EAST...AND IN RESPONSE HIGH TEMPERATURES WILL GENERALLY BE
COOLER THAN YESTERDAY. STILL VERY MILD FOR THIS TIME OF YEAR
HOWEVER...TOPPING OUT IN THE LOWER 40S THROUGH SOUTHWESTERN
MINNESOTA INTO THE EASTERN PORTIONS OF OUR IOWA ZONES...TO 50S
THROUGH THE JAMES RIVER VALLEY THROUGH THE LOWER MISSOURI RIVER
CORRIDOR.
A SURFACE TROUGH BEGINS TO APPROACH FROM THE WEST TONIGHT...AND IT
WILL BE A MILDER NIGHT WITH INCREASING WARM AIR ADVECTION OUT AHEAD
OF THE SYSTEM. WITH THAT...LOOKING AT LOWS GENERALLY LOWER TO MID
30S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 257 AM CST TUE JAN 27 2015
WEDNESDAY STILL TO BE THE FINAL VERY MILD DAY AS LOW PRESSURE PASSES
AND COOLER AIR BEGINS TO DRAIN SOUTHWARD. MODELS SIMILAR TO
YESTERDAY SO NO REAL CHANGES. STILL MAINTAIN A SMALL CHANCE FOR
LIGHT SNOW IN THE NORTH AS A WAVE PASSES BY BUT A BIT MOISTURE
STARVED SO NOT ANTICIPATING MUCH OF ANYTHING.
BECOMING A BIT WINDY LATE WEDNESDAY AFTERNOON AND NIGHT AS COLD AIR
ADVECTION AND A STRONG PRESSURE GRADIENT WORK TO MIX DOWN SOME
STRONG WINDS ALOFT. LIKELY SEE SOME WIND GUSTS OF 35 MPH OR SO
WEDNESDAY NIGHT. WITH SOME CLOUD COVER AND WIND TEMPERATURES SHOULD
STAY FAIRLY MILD FOR THIS TIME OF YEAR WITH THURSDAY MORNING LOWS
FROM THE MID 20S TO LOWER 30S.
THURSDAY STILL A BIT BREEZY AND DEFINITELY COLDER. THE LOWER LEVEL
THERMAL FIELD HAS COME IN A BIT COLDER THIS TIME AROUND WHICH IS
ALSO FAIRLY WELL AGREED UPON SO WENT AHEAD AND LOWERED HIGHS A
COUPLE OF DEGREES. HIGHS MAINLY UPPER 20S TO MID 30S.
IN THE OUTER PERIODS (FRIDAY THROUGH MONDAY)...THE COLDER PATTERN
SETTLES IN AND REMAINS IN PLACE. MODELS ALL IN PRETTY GOOD AGREEMENT
THIS TIME AROUND SO WILL KEEP TEMPERATURES ON THE COLDER SIDE OF
GUIDANCE. FRIDAY IS THE LAST OF THE MILD DAYS AS SOUTHERLY FLOW
KEEPS 925MB TEMPERATURES CLOSER TO ZERO. SATURDAY LIKELY POSING THE
POTENTIAL FOR THE BIGGEST ERROR IN FORECASTING AS THE ARCTIC
BOUNDARY IS PROGGED TO MOVE THROUGH. A LITTLE FASTER AND HIGHS WILL
BE IN THE 20S...A LITTLE SLOWER AND HIGH WOULD BE IN THE 40S SO
UPPER 20S IN THE NORTH AND MID 30S IN THE SOUTH SEEMS LIKE A GOOD
HEDGE TOWARDS THIS FAIRLY SHARP THERMAL GRADIENT. WILL ALSO HAVE A
CHANCE FOR LIGHT SNOW ON SATURDAY AND SATURDAY NIGHT AS THIS COLD
AIR SURGES SOUTH. SUNDAY AND MONDAY WELL INTO THE COLD AIR SO JUST
LOOKING AT HIGHS IN THE TEENS TO LOWER 20S AND LOWS IN THE SINGLE
DIGITS TO LOWER TEENS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1028 PM CST MON JAN 26 2015
VFR EXPECTED THROUGH 28/06Z...EXCEPT FOR AREAS OF FOG 27/09Z-
15Z. FOG WILL PRODUCE AREAS OF VISIBILITIES 3-5SM WITH LOCAL
VISIBILITIES BELOW 3SM.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...JM
LONG TERM...08
AVIATION...
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
521 AM CST TUE JAN 27 2015
.UPDATE...ADDED AVIATION SECTION FOR 12Z TAF`S.
&&
.AVIATION...BNA/CKV/CSV...CLOUDS DECK IS GOING TO BE SLOW TO
ERODE, WITH VFR CIGS LASTING INTO THE EVENING AT BNA AND CSV. CIGS
WILL ALTERNATE BETWEEN IFR & MVFR AT CSV AS BANDS OF LIGHT SNOW
MOVE ACROSS EASTERN MIDDLE TENNESSEE DURING THE MORNING. CLOUDS
WILL IMPROVE TO VFR LATER IN THE DAY AS THE DEEPEST MOISTURE PULLS
OUT.
&&
.PREV DISCUSSION... /ISSUED 315 AM CST TUE JAN 27 2015/
DISCUSSION...
CURRENTLY...SOME LIGHT SNOW INDICATED OVER CENTRAL AREAS OF KY.
LATEST MODEL RUNS SUPPORT THE SOUTHWARD MOVING IMPULSE.
HOWEVER...BEST REGION OF PVA THROUGH THE MORNING HOURS WILL BE
MAINLY EAST OF THE MID STATE...NORTHERN AREAS OF THE PLATEAU MAY
BE ON THE WESTERN FRINGE. THUS...WITH HRRR IN AGREEMENT WITH
TRENDING TOWARD LESS IN THE WAY OF SNOWFALL...WILL OPT TO TREND
DOWNWARD THE SNOW THREAT. HALF INCH ACCUMULATIONS WILL BE POSSIBLE
FOR THE NORTHERN PLATEAU ONLY FOR THIS MORNING...GENERALLY A TRACE TO A
QUARTER INCH ELSEWHERE ACROSS THE PLAT. AREAS JUST WEST OF THE
PLATEAU COULD SEE A FEW FLURRIES. OTHERWISE...CLOUDS WILL HANG ON
THROUGH TODAY...BUT CLEARING LINE NOT TOO FAR OFF TO THE
SOUTHWEST.
PARTIAL CLEARING WILL BEGIN TONIGHT AS HIGH PRESSURE SETTLES IN JUST
TO OUR NORTH. COLD TEMPS FOR TONIGHT WITH LOWS RANGING FROM NEAR 20
PLATEAU...AND MOSTLY LOWER TO MID 20S ELSEWHERE.
SUNSHINE WILL BE THE RULE FOR WEDNESDAY. A WEAK RIDGE AXIS WILL
STRETCH ACROSS THE MID STATE SO WE SHOULD SEE TEMPS WARM UP CLOSE TO
50 DEGREES FOR MOST AREAS.
A CLIPPER SYSTEM WILL THEN BE ON APPROACH AND THE ASSOCIATED
FRONTAL BOUNDARY WILL MOVE THROUGH ON THURSDAY. THIS WILL
TRANSLATE TO A CHANCE OF SHOWERS LATE WED NT INTO THURSDAY. THE
SFC LOW WILL PASS A GOOD DISTANCE TO THE NORTH OF TN. TEMPS WILL
THEREFORE REACH INTO THE LOWER TO MID 50S DURING THE DAY.
IN THE EXT FCST...COLDER AND MORE SEASONAL AIR WILL WORK IN BEHIND
THE CLIPPER SYSTEM. THEN...THE GULF STORM...THAT WE HAVE BEEN
LOOKING AT FOR SEVERAL DAYS NOW...WILL BEGIN TO GET ITS ACT
TOGETHER. FOR SEVERAL RUNS NOW...THE EURO MODEL WAS COLDER AND WAS
SUPPORTING A POTENTIAL SNOW EVENT WHILE THE GFS WAS A WARMER RAIN
SCENARIO. WELL...THE EURO HAS BACKED OFF AND IS NOW SHOWING MORE OF
A N-S TROUGH INVERSION AS OPPOSED TO THE COLDER W-E AXIS. THIS NOW
MATCHES UP WITH THE WARMER GFS SOLUTION. THUS...WILL TREND TOWARD
MORE OF A RAIN EVENT FOR SAT NT INTO SUNDAY. AT ANY RATE...LOOKS
LIKE ABOUT 1/2 TO PERHAPS 3/4 INCH RAINFALL AMOUNTS.
COLD AIR TO WORK INTO THE AREA BY SUNDAY AS THE MOISTURE IS PULLING
OUT. WILL INCLUDE A SLIGHT CHANCE OF SNOW.
MON AND TUES OF NEXT WEEK LOOK COLD...BUT NOTHING TOO BAD AS UPPER
FLOW IS MORE WESTERLY. SPLIT FLOW IS INDICATED BUT THE SOUTHERN JET
WILL BE WELL SOUTH OF THE AREA. JUST DRY WITH TEMPS 5 DEGREES OR SO
BELOW NORMAL.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
ROSE
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
315 AM CST TUE JAN 27 2015
.DISCUSSION...
CURRENTLY...SOME LIGHT SNOW INDICATED OVER CENTRAL AREAS OF KY.
LATEST MODEL RUNS SUPPORT THE SOUTHWARD MOVING IMPULSE.
HOWEVER...BEST REGION OF PVA THROUGH THE MORNING HOURS WILL BE
MAINLY EAST OF THE MID STATE...NORTHERN AREAS OF THE PLATEAU MAY
BE ON THE WESTERN FRINGE. THUS...WITH HRRR IN AGREEMENT WITH
TRENDING TOWARD LESS IN THE WAY OF SNOWFALL...WILL OPT TO TREND
DOWNWARD THE SNOW THREAT. HALF INCH ACCUMULATIONS WILL BE POSSIBLE
FOR THE NORTHERN PLATEAU ONLY FOR THIS MORNING...GENERALLY A TRACE TO A
QUARTER INCH ELSEWHERE ACROSS THE PLAT. AREAS JUST WEST OF THE
PLATEAU COULD SEE A FEW FLURRIES. OTHERWISE...CLOUDS WILL HANG ON
THROUGH TODAY...BUT CLEARING LINE NOT TOO FAR OFF TO THE
SOUTHWEST.
PARTIAL CLEARING WILL BEGIN TONIGHT AS HIGH PRESSURE SETTLES IN JUST
TO OUR NORTH. COLD TEMPS FOR TONIGHT WITH LOWS RANGING FROM NEAR 20
PLATEAU...AND MOSTLY LOWER TO MID 20S ELSEWHERE.
SUNSHINE WILL BE THE RULE FOR WEDNESDAY. A WEAK RIDGE AXIS WILL
STRETCH ACROSS THE MID STATE SO WE SHOULD SEE TEMPS WARM UP CLOSE TO
50 DEGREES FOR MOST AREAS.
A CLIPPER SYSTEM WILL THEN BE ON APPROACH AND THE ASSOCIATED
FRONTAL BOUNDARY WILL MOVE THROUGH ON THURSDAY. THIS WILL
TRANSLATE TO A CHANCE OF SHOWERS LATE WED NT INTO THURSDAY. THE
SFC LOW WILL PASS A GOOD DISTANCE TO THE NORTH OF TN. TEMPS WILL
THEREFORE REACH INTO THE LOWER TO MID 50S DURING THE DAY.
IN THE EXT FCST...COLDER AND MORE SEASONAL AIR WILL WORK IN BEHIND
THE CLIPPER SYSTEM. THEN...THE GULF STORM...THAT WE HAVE BEEN
LOOKING AT FOR SEVERAL DAYS NOW...WILL BEGIN TO GET ITS ACT
TOGETHER. FOR SEVERAL RUNS NOW...THE EURO MODEL WAS COLDER AND WAS
SUPPORTING A POTENTIAL SNOW EVENT WHILE THE GFS WAS A WARMER RAIN
SCENARIO. WELL...THE EURO HAS BACKED OFF AND IS NOW SHOWING MORE OF
A N-S TROUGH INVERSION AS OPPOSED TO THE COLDER W-E AXIS. THIS NOW
MATCHES UP WITH THE WARMER GFS SOLUTION. THUS...WILL TREND TOWARD
MORE OF A RAIN EVENT FOR SAT NT INTO SUNDAY. AT ANY RATE...LOOKS
LIKE ABOUT 1/2 TO PERHAPS 3/4 INCH RAINFALL AMOUNTS.
COLD AIR TO WORK INTO THE AREA BY SUNDAY AS THE MOISTURE IS PULLING
OUT. WILL INCLUDE A SLIGHT CHANCE OF SNOW.
MON AND TUES OF NEXT WEEK LOOK COLD...BUT NOTHING TOO BAD AS UPPER
FLOW IS MORE WESTERLY. SPLIT FLOW IS INDICATED BUT THE SOUTHERN JET
WILL BE WELL SOUTH OF THE AREA. JUST DRY WITH TEMPS 5 DEGREES OR SO
BELOW NORMAL.
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 45 25 50 38 / 10 0 0 20
CLARKSVILLE 43 25 49 40 / 10 0 0 20
CROSSVILLE 37 20 42 35 / 30 0 0 10
COLUMBIA 48 27 52 39 / 10 0 0 20
LAWRENCEBURG 50 28 52 39 / 10 0 0 10
WAVERLY 45 26 51 40 / 10 0 0 20
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
947 PM CST WED JAN 28 2015
.UPDATE...
WILL ISSUE A DENSE FOG ADVISORY FOR AREAS SOUTHWEST OF HOUSTON.
VISIBILITIES HAVE BEGUN TO DROP AND WINDS HAVE RELAXED A BIT. 43
&&
.PREV DISCUSSION... /ISSUED 823 PM CST WED JAN 28 2015/
UPDATE...
SEE EVENING UPDATE.
DISCUSSION...
AT 8 PM...SURFACE HIGH PRESSURE WAS LOCATED OVER THE NORTHERN GULF
COAST WITH A TROUGH LOW PRESSURE EXTENDING FROM EASTERN KANSAS
INTO NORTH CENTRAL TEXAS. THE PRESSURE GRADIENT BETWEEN THESE TWO
FEATURES IS RATHER TIGHT SO NOT EXPECTING WINDS TO FULLY DECOUPLE
OVERNIGHT. SFC TEMPS HAVE FALLEN TO NEAR THE DEW PT OVER THE SW
ZONES AND RAP13 FCST SOUNDINGS SHOW A VERY FAVORABLE PROFILE FOR
FOG DEVELOPMENT TONIGHT. THE HRRR IS HINTING AT FOG WITH
VISIBILITIES DROPPING TO BELOW A 1/2 MILE TONIGHT BUT JUST NOT
CONFIDENT ENOUGH TO GO WITH DENSE FOG AT THIS TIME DUE TO THE
SLIGHTLY STRONGER WINDS. WILL WATCH TRENDS CLOSELY AND IF WINDS
RELAX...A DENSE FOG ADVISORY MAY BE REQUIRED FOR THE SW HALF OF
THE REGION. 43
PREV DISCUSSION... /ISSUED 608 PM CST WED JAN 28 2015/
DISCUSSION...
SEE THE 00Z AVIATION DISCUSSION BELOW.
40
AVIATION...
THE SURFACE HIGH PRESSURE WAS SITUATED OVER THE GULF AT 6 PM AND A
SOUTHERLY FLOW WAS IN PLACE ACROSS SE TEXAS. THE NAM12 TRIES TO
RE-ESTABLISH THE RIDGE INTO THE COASTAL AREAS TONIGHT...AND THE
SURFACE WINDS SHOULD BECOME FAIRLY LIGHT. CLEAR SKIES OVERHEAD
AND A SLIGHTLY HIGHER SURFACE MOISTURE CONTENT WILL LEAD TO THE
POTENTIAL FOR AT LEAST PATCHY FOG FORMATION OVERNIGHT TONIGHT AND
THURSDAY MORNING. IF THE FOG DOES FORM...IT SHOULD BE MORE
PREVALENT OVER THE MORE RURAL SITES. AFTER 15Z...VFR CONDITIONS
ARE EXPECTED.
40
PREV DISCUSSION... /ISSUED 348 PM CST WED JAN 28 2015/
DISCUSSION...
UPPER LEVEL RIDGING AND SURFACE HIGH PRESSURE CENTERED OVER THE
SOUTHEASTERN TEXAS GULF HAS MADE FOR A MOSTLY CLEAR DAY ACROSS
THE AREA WITH THE EXCEPTION OF A FEW CIRRUS. MANY AREAS ACROSS
SOUTHEAST TEXAS HAVE MADE IT INTO THE UPPER 70S...AND IN A FEW
AREAS INTO THE LOW 80S. FOG WILL FORM OVERNIGHT AND HAVE ADDED PATCHY
FOG TO THE GRIDS. TOMORROW`S TEMPERATURES WILL A BIT COOLER DUE TO
MORE CLOUD COVER ASSOCIATED WITH THE NEXT COLD FRONT THAT SHOULD
MOVE THROUGH THE AREA THURSDAY AFTERNOON AND NIGHT. NO QPF IS
EXPECTED WITH THE FRONT. THE GFS IS THE FASTEST WITH BRINGING THE
FRONT THROUGH SOUTHEAST TEXAS AND HAVE LEANED MORE TOWARDS A
SOLUTION OF THE NAM/ECMWF DUE TO A LACK OF STRONG UPPER LEVEL
SUPPORT. BEHIND THE FRONT...TEMPS WILL FALL 10-20 DEGREES WITH
FRIDAY MORNING LOWS IN THE 40S AND HIGHS IN THE MIDDLE TO UPPER
50S.
ON SATURDAY A TRANSITION FROM A WESTERLY TO SOUTHWESTERLY FLOW
ALOFT OCCURS AS THE NEXT UPPER LEVEL TROUGH MOVES EASTWARD. THERE
MAY BE A FEW ISOLATED SHOWERS SATURDAY AFTERNOON DUE TO A SHORT
WAVE THAT WILL MOVE INTO THE AREA AHEAD OF THE UPPER LEVEL TROUGH.
GFS AND NAM SOUNDINGS DO NOT SHOW A PARTICULARLY MOIST COLUMN
DURING THE DAY ON SATURDAY. STILL...AN IMPULSE OF ENERGY AHEAD OF
THE MAIN UPPER LEVEL SYSTEM MAY BE ENOUGH FOR A FEW VERY LIGHT
SHOWERS.
THE NEXT COLD FRONT WILL MOVE THROUGH SOUTHEAST TEXAS ON
SUNDAY AFTERNOON AND EVENING. BOTH THE GFS AND ECMWF AGREE ON
FRONTAL TIMING...HAVING IT OFF THE COAST BY MONDAY AROUND 6Z
(MIDNIGHT). PRECIPITATION LOOKS TO MAINLY BE ALONG AND BEHIND THE
FRONT...WITH PRECIP TAPERING BY LATE SUNDAY NIGHT INTO EARLY
MONDAY MORNING. MIN TEMPS BEHIND THE COLD FRONT FOR MONDAY AND
TUESDAY COULD FALL INTO THE UPPER 30S FOR AREAS NORTH OF
INTERSTATE 10.
A FAIRLY UNSETTLED PATTERN REMAINS FOR THE NEXT WORK WEEK DUE TO
AN UPPER TROUGH TO THE SOUTHWEST OF THE AREA. A SERIES OF
DISTURBANCES WILL FORM AHEAD OF THE TROUGH AND MOVE INTO SOUTHEAST
TEXAS...GIVING A LOW TO MODERATE CHANCE OF PRECIP NEXT WEEK. 13
MARINE...
NAM IS STILL FORMING SEA FOG OVERNIGHT WITH THE SREF ALSO
HINTING AT SOME SEA FOG. WATER TEMPERATURES ARE IN THE UPPER 50S
ALONG THE COAST AND DEWPOINTS IN THE GULF ARE CURRENTLY ONLY IN THE
UPPER 50S. DUE TO THIS... CONFIDENCE HAS LOWERED ON THE FORMATION OF
SEA FOG. TIMING OF TOMORROWS FRONT IS STILL IN SOME DISAGREEMENT.
THE GFS PUSHES THE FRONT OFF THE COAST THURSDAY EVENING WHILE THE
EURO IS A TAD SLOWER. THE NAM IS EVEN SLOWER MOVING THE FRONT OVER
THE WATERS FRIDAY MORNING. FOR NOW HAVE LEANED TOWARDS THE EURO
COMPROMISE WHICH WOULD ALLOW WINDS OVER THE WATERS TO REACH CAUTION
CRITERIA FRIDAY MORNING. WINDS WILL THEN QUICKLY VEER TO THE
NORTHEAST AND KEEP AN EASTERLY COMPONENT THROUGH SATURDAY. SOME
ELEVATED TIDES ARE POSSIBLE SATURDAY. SUNDAY EVENING ANOTHER
STRONGER FRONT WILL MOVE OVER THE WATERS. ADVISORY CONDITIONS WILL
BE POSSIBLE. 23
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 53 72 43 57 45 / 0 10 10 10 20
HOUSTON (IAH) 54 73 47 60 46 / 0 10 10 10 10
GALVESTON (GLS) 56 70 51 57 50 / 0 10 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...43
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
823 PM CST WED JAN 28 2015
.UPDATE...
SEE EVENING UPDATE.
&&
.DISCUSSION...
AT 8 PM...SURFACE HIGH PRESSURE WAS LOCATED OVER THE NORTHERN GULF
COAST WITH A TROUGH LOW PRESSURE EXTENDING FROM EASTERN KANSAS
INTO NORTH CENTRAL TEXAS. THE PRESSURE GRADIENT BETWEEN THESE TWO
FEATURES IS RATHER TIGHT SO NOT EXPECTING WINDS TO FULLY DECOUPLE
OVERNIGHT. SFC TEMPS HAVE FALLEN TO NEAR THE DEW PT OVER THE SW
ZONES AND RAP13 FCST SOUNDINGS SHOW A VERY FAVORABLE PROFILE FOR
FOG DEVELOPMENT TONIGHT. THE HRRR IS HINTING AT FOG WITH
VISIBILITIES DROPPING TO BELOW A 1/2 MILE TONIGHT BUT JUST NOT
CONFIDENT ENOUGH TO GO WITH DENSE FOG AT THIS TIME DUE TO THE
SLIGHTLY STRONGER WINDS. WILL WATCH TRENDS CLOSELY AND IF WINDS
RELAX...A DENSE FOG ADVISORY MAY BE REQUIRED FOR THE SW HALF OF
THE REGION. 43
&&
.PREV DISCUSSION... /ISSUED 608 PM CST WED JAN 28 2015/
DISCUSSION...
SEE THE 00Z AVIATION DISCUSSION BELOW.
40
AVIATION...
THE SURFACE HIGH PRESSURE WAS SITUATED OVER THE GULF AT 6 PM AND A
SOUTHERLY FLOW WAS IN PLACE ACROSS SE TEXAS. THE NAM12 TRIES TO
RE-ESTABLISH THE RIDGE INTO THE COASTAL AREAS TONIGHT...AND THE
SURFACE WINDS SHOULD BECOME FAIRLY LIGHT. CLEAR SKIES OVERHEAD
AND A SLIGHTLY HIGHER SURFACE MOISTURE CONTENT WILL LEAD TO THE
POTENTIAL FOR AT LEAST PATCHY FOG FORMATION OVERNIGHT TONIGHT AND
THURSDAY MORNING. IF THE FOG DOES FORM...IT SHOULD BE MORE
PREVALENT OVER THE MORE RURAL SITES. AFTER 15Z...VFR CONDITIONS
ARE EXPECTED.
40
PREV DISCUSSION... /ISSUED 348 PM CST WED JAN 28 2015/
DISCUSSION...
UPPER LEVEL RIDGING AND SURFACE HIGH PRESSURE CENTERED OVER THE
SOUTHEASTERN TEXAS GULF HAS MADE FOR A MOSTLY CLEAR DAY ACROSS
THE AREA WITH THE EXCEPTION OF A FEW CIRRUS. MANY AREAS ACROSS
SOUTHEAST TEXAS HAVE MADE IT INTO THE UPPER 70S...AND IN A FEW
AREAS INTO THE LOW 80S. FOG WILL FORM OVERNIGHT AND HAVE ADDED PATCHY
FOG TO THE GRIDS. TOMORROW`S TEMPERATURES WILL A BIT COOLER DUE TO
MORE CLOUD COVER ASSOCIATED WITH THE NEXT COLD FRONT THAT SHOULD
MOVE THROUGH THE AREA THURSDAY AFTERNOON AND NIGHT. NO QPF IS
EXPECTED WITH THE FRONT. THE GFS IS THE FASTEST WITH BRINGING THE
FRONT THROUGH SOUTHEAST TEXAS AND HAVE LEANED MORE TOWARDS A
SOLUTION OF THE NAM/ECMWF DUE TO A LACK OF STRONG UPPER LEVEL
SUPPORT. BEHIND THE FRONT...TEMPS WILL FALL 10-20 DEGREES WITH
FRIDAY MORNING LOWS IN THE 40S AND HIGHS IN THE MIDDLE TO UPPER
50S.
ON SATURDAY A TRANSITION FROM A WESTERLY TO SOUTHWESTERLY FLOW
ALOFT OCCURS AS THE NEXT UPPER LEVEL TROUGH MOVES EASTWARD. THERE
MAY BE A FEW ISOLATED SHOWERS SATURDAY AFTERNOON DUE TO A SHORT
WAVE THAT WILL MOVE INTO THE AREA AHEAD OF THE UPPER LEVEL TROUGH.
GFS AND NAM SOUNDINGS DO NOT SHOW A PARTICULARLY MOIST COLUMN
DURING THE DAY ON SATURDAY. STILL...AN IMPULSE OF ENERGY AHEAD OF
THE MAIN UPPER LEVEL SYSTEM MAY BE ENOUGH FOR A FEW VERY LIGHT
SHOWERS.
THE NEXT COLD FRONT WILL MOVE THROUGH SOUTHEAST TEXAS ON
SUNDAY AFTERNOON AND EVENING. BOTH THE GFS AND ECMWF AGREE ON
FRONTAL TIMING...HAVING IT OFF THE COAST BY MONDAY AROUND 6Z
(MIDNIGHT). PRECIPITATION LOOKS TO MAINLY BE ALONG AND BEHIND THE
FRONT...WITH PRECIP TAPERING BY LATE SUNDAY NIGHT INTO EARLY
MONDAY MORNING. MIN TEMPS BEHIND THE COLD FRONT FOR MONDAY AND
TUESDAY COULD FALL INTO THE UPPER 30S FOR AREAS NORTH OF
INTERSTATE 10.
A FAIRLY UNSETTLED PATTERN REMAINS FOR THE NEXT WORK WEEK DUE TO
AN UPPER TROUGH TO THE SOUTHWEST OF THE AREA. A SERIES OF
DISTURBANCES WILL FORM AHEAD OF THE TROUGH AND MOVE INTO SOUTHEAST
TEXAS...GIVING A LOW TO MODERATE CHANCE OF PRECIP NEXT WEEK. 13
MARINE...
NAM IS STILL FORMING SEA FOG OVERNIGHT WITH THE SREF ALSO
HINTING AT SOME SEA FOG. WATER TEMPERATURES ARE IN THE UPPER 50S
ALONG THE COAST AND DEWPOINTS IN THE GULF ARE CURRENTLY ONLY IN THE
UPPER 50S. DUE TO THIS... CONFIDENCE HAS LOWERED ON THE FORMATION OF
SEA FOG. TIMING OF TOMORROWS FRONT IS STILL IN SOME DISAGREEMENT.
THE GFS PUSHES THE FRONT OFF THE COAST THURSDAY EVENING WHILE THE
EURO IS A TAD SLOWER. THE NAM IS EVEN SLOWER MOVING THE FRONT OVER
THE WATERS FRIDAY MORNING. FOR NOW HAVE LEANED TOWARDS THE EURO
COMPROMISE WHICH WOULD ALLOW WINDS OVER THE WATERS TO REACH CAUTION
CRITERIA FRIDAY MORNING. WINDS WILL THEN QUICKLY VEER TO THE
NORTHEAST AND KEEP AN EASTERLY COMPONENT THROUGH SATURDAY. SOME
ELEVATED TIDES ARE POSSIBLE SATURDAY. SUNDAY EVENING ANOTHER
STRONGER FRONT WILL MOVE OVER THE WATERS. ADVISORY CONDITIONS WILL
BE POSSIBLE. 23
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 53 72 43 57 45 / 0 10 10 10 20
HOUSTON (IAH) 54 73 47 60 46 / 0 10 10 10 10
GALVESTON (GLS) 56 70 51 57 50 / 0 10 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...43
YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND WEDNESDAY
ISSUED AT 258 PM CST TUE JAN 27 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW ARCTIC HIGH
PRESSURE NOSING SOUTHWEST ACROSS THE UPPER PENINSULA AND THE STATE
OF WISCONSIN. BUT DESPITE THE RIDGE AXIS SHARPENING OVER NE
WISCONSIN...LOW STRATUS HAS BEEN AWFULLY DIFFICULT TO ERODE THIS
AFTERNOON. CLOUDS OVER NORTHERN LAKE MICHIGAN ARE VERY SLOWLY
ERODING FROM EAST TO WEST...AND AS BOUNDARY LAYER FLOW LIGHTENS AND
BACKS TO THE NORTH LATER THIS AFTERNOON...THINK THIS WILL ACCELERATE
CLEARING OVER THE FOX VALLEY AND LAKESHORE. OTHERWISE...OVERCAST
CONDITIONS TO REMAIN OVER CENTRAL AND NORTH-CENTRAL WISCONSIN.
LOOKING UPSTREAM...CLOUDS ARE INCREASING AGAIN OVER THE NORTHERN
PLAINS AND NORTHWEST LAKE SUPERIOR AHEAD OF THE NEXT CLIPPER SYSTEM
WHICH WILL ARRIVE WEDNESDAY NIGHT. IN THE MEANTIME...CLOUD AND TEMP
TRENDS ARE THE MAIN FORECAST CONCERNS.
TONIGHT...ARCTIC HIGH PRESSURE WILL TEMPORARILY BUILD ACROSS EASTERN
WISCONSIN THIS EVENING THEN RETREAT BACK EAST OVERNIGHT. STILL
ANTICIPATING AT LEAST PARTIAL CLEARING TAKING PLACE OVER THE FOX
VALLEY AND LAKE SHORE AS THE RIDGE AXIS MOVES INTO THAT AREA. FARTHER
WEST...WINDS WILL TURN TO THE SOUTH OR SOUTHWEST...AND TRENDS OVER
THE U.P. SUPPORT THAT CLOUDS WILL JUST ROTATE NORTHWARD...LEAVING A
LOW OVERCAST DECK IN PLACE. AS A RESULT...INCREASED SKY COVER.
THEN OVERNIGHT...MID AND HIGH CLOUDS WILL BE RETURNING FROM THE
NORTHWEST...AND ANY CLEARING OVER EASTERN WISCONSIN SHOULD GO BACK
TO BROKEN OR OVERCAST. TRENDED WARMER WITH LOW TEMPS DUE TO THE
PERSISTENT CLOUD COVER.
WEDNESDAY...LOW PRESSURE WILL BE MOVING INTO THE NORTHERN
MISSISSIPPI VALLEY DURING THE AFTERNOON. AS WINDS BACK TO THE
SOUTHEAST...WARMER LOW LEVEL AIR WILL FINALLY SURGE INTO CENTRAL AND
NORTHEAST WISCONSIN...WHICH SHOULD ERODE ANY REMAINING LOW OVERCAST.
HOWEVER...WILL STILL HAVE AMPLE MID AND UPPER CLOUDS
OVERHEAD...MAKING FOR A MOSTLY CLOUDY DAY. AN 850MB WARM FRONT WILL
BE MAKING INTO NORTH-CENTRAL AND CENTRAL WISCONSIN BY LATE IN THE
AFTERNOON...BUT PROGGED SOUNDINGS CONTINUE TO SHOW A WEDGE OF DRY
AIR AROUND 10KFT THAT SHOULD BE ENOUGH TO KEEP THE AREA DRY. HIGHS
WARMING INTO THE LOW TO MID 30S.
.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY
ISSUED AT 258 PM CST TUE JAN 27 2015
NORTHWEST UPPER FLOW WILL CONTINUE THROUGH THE PERIOD...SO IT WILL
BE GENERALLY COLD AND DRY. THERE ARE AT LEAST TWO OPPORTUNITIES FOR
SOME SNOW. THE FIRST IS TOMORROW NIGHT AND EARLY THURSDAY AS JET
ENERGY APPROACHES FROM THE WEST. THERE ISN/T MUCH MOISTURE
AVAILABLE UNTIL THE SYSTEM GETS EAST OF WISCONSIN. THEREFORE SNOW
SHOULD BE LIGHT AND MIGHT BEGIN AS SLEET ACROSS THE CENTRAL AND
EAST CENTRAL AREAS. THERE IS ANOTHER CHANCE OF SNOW SATURDAY NIGHT
AND SUNDAY AHEAD OF ARCTIC AIR. THE GFS AND ECMWF HAVE A FEW WAVES
OF LOW PRESSURE THAT MOVE NORTHEAST ALONG THE FRONT...RESULTING IN
LOTS OF DIFFERENCES IN TIMING AND SNOW AMOUNTS. MILD PACIFIC AIR
WILL BRING US WARMER THAN NORMAL TEMPERATURES THURSDAY THEN BELOW
NORMAL TEMPERATURES ARE EXPECTED THROUGH THE MIDDLE OF NEXT WEEK.
THERE. WIND CHILL ADVISORIES MAY BE NEEDED MONDAY.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1121 AM CST TUE JAN 27 2015
WIDESPREAD MVFR AND IFR CIGS CONTINUE TO IMPACT THE REGION LATE THIS
MORNING. HAVE TRENDED MORE PESSIMISTICALLY WITH THIS FORECAST
DESPITE ARCTIC HIGH PRESSURE BUILDING SOUTHWEST INTO THE STATE.
THOUGH CLEARING IS TRYING TO PUSH IN FROM THE EAST...PROGRESS HAS
BEEN SLOWER THAN ORIGINALLY THOUGHT AND NOW THINK THAT THE CENTRAL
AND NORTH-CENTRAL TAFS SITES WILL REMAIN MVFR OVERCAST DURING THE
AFTERNOON AND PART OF THE EVENING. ANTICIPATED CIGS LOWERING AGAIN
OVERNIGHT IN THIS AREA AS THE INVERSION LOWERS. ACROSS EASTERN
WISCONSIN...POTENTIAL REMAINS FOR CLEARING TO TAKE PLACE LATER THIS
AFTERNOON WHEN WINDS OFF THE LAKE SUBSIDE. NO MATTER WHAT THE LOW
CLOUDS DO...MID AND HIGH CLOUDS WILL BE INCREASING TONIGHT THOUGH
EXPECT PRECIP TO HOLD OFF UNTIL LATER PERIODS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1122 PM CST MON JAN 26 2015
.UPDATE...
ISSUED AT 856 PM CST MON JAN 26 2015
CONDITIONS HAVE GREATLY IMPROVED OVER THE PAST HOUR. THIS IS DUE
TO A COMBINATION OF DIFFERENT REASONS:
1. PRECIPITATION HAS BEEN ON THE WANE. THERE WAS A NICELY EVIDENT
VORT MAX ON RADAR THAT CAME THROUGH THE FORECAST AREA BETWEEN
23-01Z. SUBSIDENCE IN THE WAKE OF THIS VORT HAS HELPED TO SQUASH A
LOT OF THE DEVELOPMENT PREVIOUS MODEL RUNS WERE SUGGESTING ALONG
THE INVERTED SURFACE TROUGH. ADDITIONALLY...SURFACE CONVERGENCE
ALONG THE TROUGH IS NOT THAT STRONG AS WINDS HAVE DIMINISHED SOME
WEST OF THE MISSISSIPPI RIVER. LASTLY...ALL THE PREVIOUS SNOW
THAT WAS UP IN NORTHWEST WISCONSIN HAS NOW PROGRESSED TO THE
SOUTHEAST INTO EASTERN WI AND OUT OF THE FORECAST AREA.
2. ROADS HAVE BEEN IMPROVING RESULTING FROM TREATMENTS WORKING ON
THEM. THE DIMINISHING OF PRECIPITATION HAS ONLY AIDED THIS MORE.
DUE TO THE IMPROVING CONDITIONS...HAVE CANCELLED THE WINTER
WEATHER ADVISORY EARLY. STILL CANNOT RULE OUT SOME PATCHY LIGHT
FREEZING DRIZZLE OR LIGHT SNOW WITH THAT INVERTED TROUGH
AROUND...BUT NOT ENOUGH COVERAGE EXISTS TO WARRANT THE ADVISORY
OUT ANYMORE.
UPDATE ISSUED AT 459 PM CST MON JAN 26 2015
HAVE EXPANDED THE ADVISORY INTO FAR SOUTHWEST WISCONSIN WHERE
NUMEROUS REPORTS OF BAD ROADS HAVE BEEN RECEIVED...ESPECIALLY
SECONDARY ROADS.
ALSO HAVE EXTENDED THE ADVISORY UNTIL MIDNIGHT. A WARM FRONT SITS
ALONG THE MISSISSIPPI RIVER...WHICH APPEARS TO BE STUCK NOW THAT
ITS PARALLEL WITH THE UPPER LEVEL FLOW. ADDITIONALLY...A SURFACE
LOW OVER NORTHWEST WI WILL RIDE DOWN ALONG THIS FRONT...SETTING UP
AN INVERTED TROUGH IN ITS WAKE. LOW LEVEL VERTICAL MOTION SHOULD
PERSIST ALONG AND EAST OF THIS BOUNDARY...AND WITH TEMPERATURES IN
THIS ZONE BELOW FREEZING...WE SHOULD SEE A CONTINUATION OF
FREEZING DRIZZLE THROUGH THE EVENING. THIS IS SHOWN NICELY IN THE
LATEST HRRR RUNS...RAP...26.12Z REGIONAL CANADIAN AND 26.18Z NAM.
ANOTHER CONCERN IS THE MASS OF SNOW MARCHING SOUTH OUT OF
NORTHWEST WISCONSIN...WHICH SHOULD MARCH DOWN THROUGH CENTRAL WI
OVER THE NEXT FEW HOURS. THE COMBINATION OF THIS SNOW AND
FREEZING DRIZZLE WARRANTS A CONTINUATION OF THE ADVISORY. LUCKILY
IMPACTS SHOULD CONTINUE TO DECREASE AS ROADS CONTINUE TO BE
TREATED...THOUGH THE LOSS OF DAYTIME HEATING WILL ALLOW UNTREATED ROADS
TO COOL AND MAKE THINGS WORSE.
&&
.SHORT TERM...(TONIGHT THROUGH TUESDAY NIGHT)
ISSUED AT 331 PM CST MON JAN 26 2015
MAIN FORECAST PROBLEM WILL BE LINGERING FREEZING DRIZZLE
CHANCES THROUGH THIS EVENING.
SURFACE MAP THIS AFTERNOON HAS SURFACE LOW OVER THE ARROWHEAD WITH A
WARM FRONT EXTENDING ACROSS EASTERN MN/IA. TEMPERATURES RANGED FROM
THE MIDDLE 30S TO MIDDLE 40S BEHIND THE FRONT ACROSS SOUTHEAST
MN/NORTHEAST IA...TO THE LOWER TO MIDDLE 20S EAST OF THE MISSISSIPPI
RIVER/AHEAD OF THE FRONT. LOWER LEVEL ISENTROPIC LIFT ACROSS THIS
FRONT WAS PRODUCING AREAS OF FREEZING DRIZZLE EAST OF THE
MISSISSIPPI WITH REPORTS OF SOME SLIPPERY STRETCHES ON ROADWAYS VIA
WI 511 AND FROM LOCAL ROAD CREW.
LOOK FOR THE SURFACE LOW TO MOVE SOUTHEAST FROM THE ARROWHEAD OF MN
THIS AFTERNOON INTO NORTHWEST IL BY EARLY THIS EVENING. MAIN LIFT
AHEAD OF THIS LOW ...WHICH IS PRESENTLY CAUSING THE FREEZING DRIZZLE
WILL THEREFORE BE IN A WANING PHASE WITH ITS PASSAGE. HOWEVER...RAP
BUFKIT SOUNDING SHOWS SOME LINGERING LIFT ACROSS CENTRAL WI THROUGH
LATER THIS EVENING AS THE MID-LEVEL/SURFACE INVERTED TROUGH HANGS
UP. WILL THEREFORE CONTINUE TO CARRY FREEZING DRIZZLE MENTION INTO
THIS EVENING. THERE MAY BE SOME LIGHT SNOW AS WELL WITH POCKETS OF
FEEDER/SEEDER ICE. MAY HAVE TO EXTEND CURRENT ADVISORY A LITTLE
LONGER INTO THIS EVENING TO COVER FOR THIS. WILL KEEP A CLOSE EYE ON
IT.
HIGH PRESSURE BUILDS OVER THE AREA LATER TONIGHT THROUGH TUESDAY FOR
QUIET WEATHER. LOOKS LIKE IT WILL REMAIN MOSTLY CLOUDY THOUGH DESPITE
HIGH BUILDING IN DUE TO MOISTURE BEING TRAPPED UNDER THE SUBSIDENCE
INVERSION. WITH PARTIAL SUNSHINE LATE IN THE MORNING THROUGH THE
AFTERNOON...PLAN ON HIGHS REBOUNDING INTO THE 30S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 331 PM CST MON JAN 26 2015
UNSEASONABLY MILD CONDITIONS EXPECTED FOR WEDNESDAY AHEAD OF
APPROACHING LOW PRESSURE ACROSS THE PLAINS. DESPITE AN INCREASE IN
STRATUS CLOUD...LOOK FOR HIGHS WELL INTO THE 30S WITH POSSIBLY A FEW
LOWER 40 READINGS ACROSS PARTS OF NORTHEAST IA INTO FAR SOUTHWEST WI.
A WINTRY MIX LOOKS TO IMPACT THE AREA WEDNESDAY NIGHT INTO THURSDAY
MORNING AS THE LOW OVER THE PLAINS MOVES TOWARD THE GREAT LAKES
REGION. MODEL SOUNDINGS NOT SHOWING A LOT OF ICE IN CLOUD FOR SNOW
PRODUCTION...SO LOOKS LIKE MORE OF A FREEZING RAIN/DRIZZLE POTENTIAL
AS A RESULT. WILL CONTINUE TO MONITOR THIS.
LATEST GFS/ECMWF SHOW ANOTHER STORM SYSTEM MOVING OUT OF THE PLAINS
TOWARD THE UPPER MISSISSIPPI RIVER REGION SATURDAY AFTERNOON INTO
SUNDAY FOR SNOW CHANCES.
OTHERWISE...LOOKS LIKE A SIGNIFICANT COOL DOWN THROUGH THE
WEEKEND/EARLY NEXT WEEK AS PATTERN SHIFTS TO NORTHWEST FLOW ALOFT.
HIGHS ON SATURDAY EXPECTED TO BE IN THE 20S...COOLING INTO THE
SINGLE DIGITS/TEENS BY MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1122 PM CST MON JAN 26 2015
STRATUS CONTINUES TO PLAGUE THE TAF SITES THIS EVENING...MOSTLY
OF THE MVFR VARIETY BUT OCCASIONALLY VFR. WITH THE FLOW TURNING
NORTHERLY AND PLENTY OF STRATUS THAT EXTENDS INTO NORTHERN
ONTARIO...BELIEVE THE STRATUS WILL STICK AROUND THROUGH MUCH OF
TUESDAY. ADDITIONALLY...WITH TEMPERATURES ABOVE THE CLOUD
WARMING...ITS POSSIBLE THAT THE CLOUD WILL GET PUSHED LOWER
CAUSING CEILINGS TO LOWER. FOR NOW STILL KEPT THE CEILINGS IN THE
MVFR RANGE...BUT BEARS WATCHING. AS WINDS SWING AROUND TO THE
SOUTH TO SOUTHWEST TUESDAY EVENING...FOLLOWING THE PASSAGE OF A
SURFACE RIDGE OF HIGH PRESSURE...ANTICIPATING CLEARING OF THE LOW
CLOUDS CURRENTLY IN WESTERN IOWA TO SURGE THROUGH THE TAF SITES.
ONLY LAST ITEM OF NOTE ARE SOME SNOW SHOWERS MOVING THROUGH LSE.
THESE SHOULD BE DONE BY 07Z AS THE TROUGH FORCING THEM WEAKENS.
ANY VISIBILITY REDUCTION SHOULD BE LIMITED TO MVFR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...AJ
SHORT TERM...DAS
LONG TERM....DAS
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1021 PM CST MON JAN 26 2015
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.UPDATE...
ISSUED AT 545 PM CST MON JAN 26 2015
QUICK CHECK WITH WOOD COUNTY INDICATED ROADS JUST SNOW COVERED...
WITH NO MAJOR TRAVEL PROBLEMS REPORTED. WILL ALLOW THE ADVISORY
TO EXPIRE AT 600 PM.
&&
.SHORT TERM...TONIGHT AND TUESDAY
ISSUED AT 245 PM CST MON JAN 26 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A WEAKENING
LOW PRESSURE SYSTEM MOVING SSE AS IT APPROACHES FAR NORTHWEST
WISCONSIN. AHEAD OF THE LOW...MODEST WARM ADVECTION AND MID-LEVEL
FGEN ARE CONTRIBUTING TO A BAND OF SNOW...BUT THE BEST RETURNS
APPEAR TO BE EXITING CENTRAL WISCONSIN EARLY THIS AFTERNOON. THE
LATEST DATA SHOW THAT THE MID-LEVEL FGEN WILL CONTINUE TO WEAKEN AS
THE BEST WARM ADVECTION PULLS OUT...SO SHOULD SEE ONLY VERY LIGHT
SNOW OR FLURRIES FOR A PERIOD UNTIL BETTER RETURNS OVER WESTERN LAKE
SUPERIOR ARRIVE. STILL SEEING OBSERVATIONS AT MARSHFIELD AND
MEDFORD OF FREEZING DRIZZLE OR UNKNOWN PRECIP...SO NO PLANS TO
CHANGE THE ADVISORY. SOME POSSIBILITY THAT IT COULD GET EXTENDED
INTO THE EVENING...BUT NO INDICATIONS OF FREEZING DRIZZLE ELSEWHERE
THOUGH. SNOWFALL ACCUMS AND IMPACTS REMAIN THE MAIN FORECAST
CONCERNS.
TONIGHT...CLIPPER LOW PRESSURE WILL CONTINUE TO WEAKEN AS IT TRACKS
ACROSS FAR SW WISCONSIN EARLY THIS EVENING AND INTO WESTERN
ILLINOIS. ANOTHER AREA OF LIGHT SNOW ASSOCIATED WITH WARM ADVECTION
WILL MOVE ACROSS NORTH-CENTRAL AND EASTERN WISCONSIN THAT WILL
PROLONG THE LIGHT SNOW FOR MUCH OF THE EVENING. THE SNOW WILL
LIKELY DIMINISH OVER CENTRAL WISCONSIN BY MID TO LATE EVENING...BUT
SATURATION WILL REMAIN DEEP ENOUGH FOR PATCHY FREEZING DRIZZLE...SO
LEFT THAT POSSIBILITY IN THE FORECAST ON THE WESTERN EDGE OF THE
PRECIP. THE HIGHEST ACCUMULATIONS WILL BE OVER EASTERN WISCONSIN
WHERE A HALF INCH OR INCH WILL LIKELY FALL. LIGHT ONSHORE FLOW FROM
SE WINDS MAY LOCALLY BOOST TOTALS HIGHER OVER THE DOOR PENINSULA
FROM LAKE ENHANCEMENT. MOST GUIDANCE SUPPORTS LIGHT PRECIP
DIMINISHING LATE TONIGHT ACROSS THE EAST...THOUGH FLURRIES COULD
CONTINUE IN THE EAST DUE TO THE LIGHT ONSHORE FLOW. LOWS MAINLY
BETWEEN 19-24 DEGREES.
TUESDAY...BECAUSE WEAK LOW LEVEL CONVERGENCE WILL BE
CONTINUING...THINK OVERCAST CONDITIONS WILL PERSIST THROUGH MUCH OF
THE MORNING HOURS. AS ARCTIC HIGH PRESSURE TRIES TO REBUILD INTO
THE REGION DURING THE AFTERNOON...SHOULD SEE THE LOW OVERCAST ERODE
FROM THE WEST AND ALSO THE EAST WHICH WILL LEAD TO INCREASING
SUNSHINE. HIGHS WILL RANGE FROM THE UPPER 20S TO LOWER 30S.
.LONG TERM...TUESDAY NIGHT THROUGH MONDAY
ISSUED AT 245 PM CST MON JAN 26 2015
A COUPLE OF WEAK UPPER TROUGHS WILL APPROACH FROM THE WEST
WEDNESDAY NIGHT AND BRING SOME LIGHT SNOW TO THE REGION. NOT
MUCH MOISTURE AVAILABLE BUT THERE IS PRETTY GOOD LOW LEVEL WARM
ADVECTION AND CONVERGENCE IN NORTHEAST WISCONSIN. THINK WE WILL
GET 1 TO 3 INCHES WITH THE GREATEST AMOUNTS OVER DOOR MARINETTE
AND FLORENCE AND FOREST COUNTIES.
LAKE EFFECT SNOW SHOWERS POSSIBLE IN NORTHCENTRAL WISCONSIN
WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT BUT ACCUMULATIONS SHOULD
BE LIGHT. DRY AND COLDER FRIDAY AND SATURDAY. AN ARCTIC COLD
FRONT WILL APPROACH THE AREA SATURDAY NIGHT AND SUNDAY AND SHOULD
BE ABLE TO PRODUCE SOME LIGHT SNOW AS IT MOVES ACROSS THE AREA.
MONDAY SHOULD BE QUITE COLD WITH SUBZERO HIGHS POSSIBLE IN
NORTHERN WISCONSIN.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1019 PM CST MON JAN 26 2015
THE SYSTEM PRODUCING THE SNOW WILL CONT TO SLOWLY SHIFT OFF TO
THE SE TNGT...BUT MVFR/IFR CIGS WILL LINGER IN THE MOIST CYCLONIC
FLOW REMAINING BEHIND THE DEPARTING SYSTEM. CIGS IN CENTRAL WI MAY
EVEN DROP INTO THE LIFR CATEGORY FOR A WHILE OVERNIGHT.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE.........SKOWRONSKI
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......SKOWRONSKI
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
358 AM CST THU JAN 29 2015
.SHORT TERM...
358 AM CST
TODAY THROUGH FRIDAY NIGHT...
THE MAIN FORECAST CONCERNS THIS MORNING INVOLVE THE AREA OF LOW
PRESSURE CURRENTLY OVER WEST CENTRAL ILLINOIS...AND INCLUDE PRECIP
TIMING/TYPE...TEMPERATURE TRENDS...GUSTY WINDS...AND EVENTUALLY THE
POTENTIAL FOR SOME LAKE EFFECT SNOW SHOWERS OVER NORTHWEST INDIANA
TONIGHT INTO FRIDAY.
THE SURFACE LOW CENTER WAS JUST SOUTHWEST OF LASALLE/PERU ILLINOIS
AT 3 AM CST...WITH THE ASSOCIATED CYCLONIC WIND CIRCULATION PULLING
RELATIVELY MILD AIR NORTH ACROSS THE EASTERN 2/3 OF THE CWA.
CHALLENGING HOURLY TEMPERATURE FORECAST...AS READINGS MAY REACH 40
DEGREES IN THE SOUTHEAST EARLY THIS MORNING BEFORE THE LOW PASSES
AND SHIFTS WINDS TO THE NORTHWEST AND PULLS IN COLDER AIR. WITH THE
EXCEPTION OF A BAND OF RAIN SHOWERS LATE LAST EVENING...LITTLE
PRECIPITATION HAS BEEN OCCURRING WITH THIS SYSTEM EXCEPT NORTH/EAST
OF THE FORECAST AREA OVERNIGHT. REGIONAL RADAR MOSAIC HAS BEEN
DEPICTING PERSISTENT LIGHT RETURNS BEHIND THE LOW/COLD FRONT HOWEVER
WHERE SOME OCCASIONAL DRIZZLE OR "UNKNOWN" PRECIP HAS BEEN REPORTED.
HIGH-RES GUIDANCE TRENDS CONTINUE TO INDICATE SOME VERY LIGHT
PRECIPITATION IS POSSIBLE ACROSS THE AREA THIS MORNING...WITH
FORECAST SOUNDINGS INDICATING MAINLY DRIZZLE WITH SATURATION MAINLY
IN LOW LEVELS AS COLDER AIR MOVES IN...THOUGH A BRIEF PERIOD OF
MID-LEVEL MOISTURE WITH RAGGED DEFORMATION AREA ALONG WEST/NORTHWEST
SIDE OF THE LOW COULD BRIEFLY INTRODUCE ICE INTO LOW LEVELS IN A
SEEDER-FEEDER SITUATION WHICH COULD RESULT IN A MIX OF DRIZZLE/LIGHT
RAIN AND LIGHT SNOW THIS MORNING...THOUGH NOT EXPECTING ANY REAL
MEASURABLE PRECIPITATION OR SNOW WITH THIS. STRONG DRYING ABOVE THE
BOUNDARY LAYER FROM THE NORTHWEST BY MIDDAY SHOULD ALLOW ANY LIGHT
PRECIP TO END FROM WEST TO EAST THROUGH THE LATE MORNING AND MIDDAY
HOURS.
WINDY CONDITIONS WILL DEVELOP DURING THE MORNING AS COLD ADVECTION
STEEPENS OUR LOW LEVEL LAPSE RATES IN THE TIGHT PRESSURE GRADIENT
WEST OF THE LOW. FORECAST SOUNDINGS INDICATE GUSTS AROUND 35 MPH
WILL BE POSSIBLE FROM MID-MORNING THROUGH THE AFTERNOON BEFORE WINDS
GRADUALLY DIMINISH TONIGHT. A QUICK NOTE OF TEMPERATURES WEST OF THE
LOW THIS MORNING INDICATES READINGS DO NOT DROP OFF TOO DRAMATICALLY
AND WILL LIKELY SEE STEADY TEMPS FOR THE MOST PART UNTIL LATE TODAY.
(EXCEPT IN THE SOUTHEAST WHERE TEMPS APPROACH 40 THIS MORNING...WILL
LIKELY SETTLE BACK TO THE MID 30S THERE).
AS FOR LAKE EFFECT TONIGHT...LOW LEVEL WINDS FROM THE
NORTH-NORTHWEST (AROUND 340 DEG) SUPPORT AN INITIAL CONVERGENCE ZONE
ALONG THE SOUTHWEST MICHIGAN SHORE THIS AFTERNOON AND EARLY THIS
EVENING...THOUGH OUR LOCALLY RUN ARW MODEL DOES VEER WINDS LATER
TONIGHT AND BRINGS CONVERGENT BAND INTO PORTER COUNTY LATE TONIGHT
INTO EARLY FRIDAY. LARGER SCALE FLOW BACKS MORE WESTERLY FRIDAY
AFTERNOON WHICH SHOULD PUSH ANY LINGERING SNOW SHOWERS BACK EAST OF
PORTER COUNTY BY MID/LATE FRIDAY AFTERNOON. THERMODYNAMICS ARE NOT
SPECTACULAR...THOUGH VARIOUS MODEL FORECAST SOUNDINGS DEVELOP
LAKE-850 HPA DELTA-T AROUND 17C EARLY FRIDAY WITH INVERSION HEIGHTS
5000-6000 FT BEFORE CONDITIONS GRADUALLY WANE LATER FRIDAY MORNING.
DEPENDING UPON HOW LONG THE BAND BACKS UP INTO PORTER/EASTERN LAKE
COUNTIES WILL MODULATE THE SNOWFALL ACCUMULATION POTENTIAL...THOUGH
A FEW INCHES ARE CERTAINLY POSSIBLE IF THE BAND DOES HANG UP THERE
FOR A WHILE LATE TONIGHT/EARLY FRIDAY...BEFORE EXPANSIVE SURFACE
HIGH BUILDS ACROSS THE AREA THROUGH FRIDAY NIGHT.
RATZER
&&
.LONG TERM...
358 AM CST
SATURDAY THROUGH WEDNESDAY...
THE MAIN CONCERN IN THE EXTENDED PERIOD CONTINUES TO BE THE
POTENTIAL FOR SOME ACCUMULATING SNOW OVER THE WEEKEND...ESPECIALLY
ACROSS THE SOUTHERN PART OF THE CWA LATE SATURDAY NIGHT AND SUNDAY.
GLOBAL RUNS CONTINUE TO SHOW AGREEMENT IN FIRST SAGGING A COLD FRONT
SOUTH ACROSS THE AREA SATURDAY...THEN WITH THE AMPLIFICATION OF AN
UPPER TROUGH OVER THE REGION WITH SUBSEQUENT SURFACE LOW DEVELOPMENT
OVER THE LOWER MISSISSIPPI VALLEY. WHILE THE TRACK OF THE SURFACE
LOW HAS TRENDED SOUTH OVER THE PAST FEW RUNS (NOW FROM THE LOWER
MISS VALLEY TO THE MID-ATLANTIC OR CAROLINA COAST BY MONDAY
MORNING)...NORTHERN PERIPHERY OF DEFORMATION BAND SNOW ACROSS
CENTRAL ILLINOIS/INDIANA WOULD STILL AFFECT SOUTHERN COUNTIES OF THE
LOT CWA AT THIS POINT. IN ADDITION...INCREASING NORTH-NORTHEAST
WINDS NORTH OF THE LOW TRACK COMBINED WITH ARCTIC AIR INTRUSION
BEHIND SATURDAY COLD FRONT COULD VERY WELL LEAD TO LAKE
EFFECT/ENHANCED SNOW SHOWERS INTO THE CHICAGO METRO AREA. SO...
WHILE MANY DETAILS REMAIN TO BE WORKED OUT HAVE MAINTAINED DECENT
CHANCE POPS FOR MEASURABLE SNOW ACROSS THE FORECAST AREA FOR THE
WEEKEND. STILL LOOKS COLD BEYOND THE WEEKEND INTO NEXT WEEK WITH
DEEP TROUGH ACROSS THE EAST...THOUGH PATTERN CONTINUES TO BE
PROGRESSIVE IN LONGER RANGE GUIDANCE SOLUTIONS WHICH KEEPS IT FROM
STICKING AROUND TOO LONG.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* SOUTH-SOUTHEAST WINDS TURNING NORTHWEST BY 13Z WITH A BRIEF
PERIOD OF LIGHT AND VARIABLE WINDS POSSIBLE FROM 10Z TO 13Z.
NORTHWEST GUSTS OF 30-35 KT FROM MID MORNING THROUGH THE
AFTERNOON.
* LOW MVFR CIGS AND POSSIBLY MVFR VISIBILITY ARRIVING NEAR OR
SHORTLY AFTER DAYBREAK. IFR CIGS POSSIBLE IFR FOR A FEW HOURS
THIS MORNING.
* DRIZZLE POSSIBLE 12Z-14Z...THEN A BRIEF PERIOD OF LIGHT
RAIN/SNOW SHOWERS LIKELY MID-MORNING.
//DISCUSSION...UPDATED 06Z...
LOW PRESSURE ACROSS SOUTHEAST IOWA AT 530Z WILL MOVE CLOSE TO MDW
AND GYY BY 12Z AND THEN ONTO LOWER MICHIGAN THROUGH THE REST OF
THURSDAY MORNING. BECAUSE OF THIS PATH...A TEMPORARY PERIOD OF
LIGHTER VARIABLE WINDS IS BECOMING MORE PROBABLE AT CHICAGO AREA
TAF SITES BETWEEN 10Z-13Z OR SO. BEHIND THE LOW PASSAGE ON
THURSDAY MORNING...THE WINDS WILL TURN TO THE NORTH-NORTHWEST AND
THEN NORTHWEST WITH SPEEDS QUICKLY INCREASING. OCCASIONAL GUSTS OF
30 TO 35 KT LOOK PROBABLE FOR DURING THE DAY THURSDAY.
SPOTTY LIGHT RAIN SHOWERS OR DRIZZLE WILL BE SEEN UNTIL THE STRONG
COLD ADVECTION ARRIVES. CIGS WILL ALSO DROP LOWER AS THE SYSTEM
CENTER PASSES. BASED ON UPSTREAM OBSERVATIONS...1000-1500 FT CIGS
ARE HIGHLY LIKELY WITH POTENTIAL FOR A PERIOD OF 600-900 FT CIGS
DURING THE MORNING. IN ADDITION...AS THE SYSTEM BEGINS TO
INTENSITY OVER LOW MICHIGAN...A BACKSIDE DEVELOPING AREA OF LIGHT
RAIN AND/OR SNOW IS EXPECTED TO MOVE CLOSE TO OR OVER THE TAF
SITES. THIS SHOULD LIKELY LAST NO LONGER THAN 90 MINUTES AT ANY
ONE SITE AND NO ACCUMULATION IS EXPECTED. MVFR CIGS ARE LIKELY TO
LAST INTO THURSDAY EVENING.
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* WHILE LOW ON SPECIFIC WIND DIRECTION 10Z-13Z...HIGH CONFIDENCE
THAT SPEEDS WILL BE LESS THAN 10 KT IN THAT PERIOD. HIGH
CONFIDENCE IN WINDS AFTER 13Z.
* HIGH IN MVFR CIGS AND TIMING. MEDIUM IN CIG BASES AND THAT A
BRIEF PERIOD OF IFR WILL OCCUR.
* MEDIUM IN PERIOD OF MVFR VISIBILITY THIS MORNING.
* MEDIUM IN CHANCE FOR A BRIEF PERIOD OF MIXED PRECIP THIS
MORNING. HIGH IN NO SNOW ACCUMULATION OCCURRING.
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
FRIDAY...VFR. NORTHWEST WINDS.
SATURDAY...CHANCE OF SNOW AND IFR DURING THE NIGHT. SOUTHWEST
WINDS.
SUNDAY...SNOW AND IFR LIKELY. NORTHEAST WINDS.
MONDAY...CHANCE OF SNOW WITH MVFR LIKELY. IFR POSSIBLE. NORTHWEST
WINDS.
TUESDAY...SLIGHT CHANCE OF SNOW DURING THE NIGHT. SOUTHWEST WINDS.
MTF/MDB
&&
.MARINE...
205 AM CST
A PROGRESSIVE ACTIVE PATTERN WILL CONTINUE ACROSS THE GREAT LAKES
REGION INTO THE BEGINNING OF FEBRUARY. MOVING EASTWARD EARLY THIS
MORNING IS AN ELONGATED TROUGH WITH TWO LOW PRESSURE CENTERS
COMPOSING IT...ONE PASSING JUST SOUTH OF LAKE MICHIGAN AND ANOTHER
OVER EASTERN LAKE SUPERIOR. TOGETHER THESE WILL CONSOLIDATE LATER
TODAY AND DRIVE MORE FOCUSED AND STRENGTHENING COLD ADVECTION
OVER LAKE MICHIGAN. THIS WITHIN THE STRONG AND ADVECTING PRESSURE
GRADIENT WILL SUPPORT NORTHWEST TO NORTH GALES...EVEN 45 KT GUST
POTENTIAL ACROSS PARTS OF THE NORTH. THE ILLINOIS AND ESPECIALLY
THE INDIANA NEAR SHORES SHOULD AT LEAST EXPERIENCE PERIODIC GALE
GUSTS INTO THIS EVENING. COLDER TEMPERATURES WILL BE WORKING
SOUTHWARD ACROSS THE LAKE LATER TODAY AND TONIGHT. SUPPORT FOR
HEAVY FREEZING SPRAY REMAINS OVER MAINLY THE NORTH AND CONTINUE
THE WARNING THERE. WAVES ARE LIKELY TO BUILD TO 12-15 FT TONIGHT
AT DOWNSTREAM FETCH LOCATIONS ON THE EASTERN HALF OF THE LAKE.
WINDS WILL GRADUALLY DIMINISH OVERNIGHT INTO FRIDAY MORNING AND
MORE QUICKLY AFTERWARD AS HIGH PRESSURE MOVES OVER THE LAKE.
BEYOND...THERE LOOKS LIKE OPPORTUNITIES FOR AT LEAST 30 KT WINDS
NEXT WEEK. ONE OF THESE IS BEHIND A COLD FRONT SATURDAY AFTERNOON
AND MORE SO SATURDAY NIGHT. MORE 30 KT WIND POTENTIAL WOULD COME
POSSIBLY TUESDAY AS RETURN SOUTHWEST FLOW SPREADS BACK OVER THE
LAKE.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 AM THURSDAY.
GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...10 AM
THURSDAY TO 3 AM FRIDAY.
GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...9 AM THURSDAY TO 3 AM
FRIDAY.
HEAVY FREEZING SPRAY WARNING...LMZ261-LMZ362-LMZ364-LMZ366-
LMZ563-LMZ565-LMZ567-LMZ868...2 PM THURSDAY TO 3 AM FRIDAY.
&&
$$
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[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
330 AM CST Thu Jan 29 2015
.SHORT TERM...(Today)
ISSUED AT 329 AM CST THU JAN 29 2015
Low pressure centered just north of Moline at 08z/2am will continue
to push east and drag a cold front through our area this morning.
Warmest temperatures will be just ahead of the cold front early this
morning, and then we expect temperatures to fall off quickly just
behind the cold front during the remainder of the morning, and then
hold fairly steady this afternoon. Winds will be gusty again today
but this time out of the northwest with a few gusts of 35 to 40 mph
at times about an hour or two after frontal passage right along the
stronger surface pressure rises. Look for gusts in the 30 to 35 mph
range this afternoon.
Not seeing a lot of precip, other than some occasional very light
rain/drizzle out in Iowa and northern MO so will continue with
just a slight chance of light rain/snow this morning with POPs
decreasing from west to east this afternoon, and that would be
mainly across the north half of the forecast area. Latest
satellite data and upstream surface observations not showing much
hope for any clearing across our area in the near term. Forecast
soundings off the NAM-WRF showing a fairly strong subsidence
inversion setting up again in the wake of this system resulting in
quite a bit of low level moisture trapped beneath the inversion at
around 2500-3000 feet. As a result, we have backed off with any
decrease in cloud cover until later this evening and that may be
optimistic based on the latest (06z) forecast soundings off the
NAM.
&&
.LONG TERM...(Tonight through Wednesday)
ISSUED AT 329 AM CST THU JAN 29 2015
Short wave trof to exit east and se of IL early this evening as
Canadian high pressure over the Canadian Rockies settles into the
upper Midwest tonight. However an inversion will likely trap low
level clouds longer tonight and have trended the forecast slower
with decreasing low clouds from the west. Low clouds could linger
over ne counties into Friday morning especially near IN border.
Cooler lows tonight in upper teens to near 20F northern areas to mid
20s in southeast IL. Brisk nw winds 15-25 mph this evening to slowly
diminish during overnight into Friday morning as high pressure
settles into IL on Friday. Highs Friday 29-35F with coolest readings
from I-74 ne with partly to mostly sunny skies.
High pressure settles into the Ohio river valley Friday evening and
into central Appalachians by dawn Sat and continue fair/dry weather
through at least Saturday morning. Lows Friday night in upper teens
and lower 20s again. Milder highs Sat in upper 30s and lower 40s
with mildest readings sw areas with ssw breezes. Clouds to increase
later Friday night into Sat ahead of next storm system with slight
chance of light rain/snow later Saturday afternoon west of I-55. Most
over central and especially eastern IL should still be dry through the
daytime hours on Saturday.
12Z Jan 28 forecast models trended further south with low pressure
system Sat night and Sunday, while 00Z Jan 29 forecast models have
trended back north with more phasing of southern and northern stream
upper level systems, along with higher snowfall amounts over central
and southeast IL. 00Z models have also trended colder with even
southeast IL looking like all snow with this eveng and mixed
precipitation south of I-64 toward the ohio river. Confidence is not
too high yet with this potentially high impact winter weather event
with extended period of overrunning snow developing Saturday night
and continue through Sunday before diminishing Sunday night. Several
inches of snow still appears possible over central and southeast IL.
Canadian high pressure settles into IL Monday returning dry and
colder weather. A northern stream short wave races ese into Great
Lakes region late Tue and Tue night bringing small chances of light
snow with best chances ne of central IL. Another Canadian high
pressure settles into region by Thu brining in even colder air. So
after above normal temps overall since mid Jan, next week (first
week of Feb) looks like temps will likely be below normal.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
ISSUED AT 1143 PM CST WED JAN 28 2015
Low pressure currently centered over eastern Iowa will track across
north-central Illinois tonight, then into Michigan by Thursday
morning. A tight pressure gradient ahead of the low will continue
to provide gusty southeasterly winds that will gradually veer to
the southwest after midnight, before veering sharply to the northwest
after FROPA between 12z and 15z Thu. Forecast soundings remain
quite dry, although models are hinting at perhaps a few light
showers near the low track, so have included VCSH at the I-74
terminals Thursday morning. VFR conditions will prevail until the
front passes and winds become northwesterly, at which time MVFR
ceilings currently over the Dakotas and western Iowa will spill
southeastward into the area. Based primarily on HRRR timing, have
introduced MVFR ceilings at KPIA by 10z, then further east to KCMI
by 13z. Once the low clouds arrive, they will stick around through
Thursday afternoon. Winds will be quite strong as well, with
northwesterly gusts in the 25 to 30kt range.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Smith
LONG TERM...07
AVIATION...Barnes
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
208 AM CST THU JAN 29 2015
.UPDATE...
901 PM...EVENING UPDATE...WEAK UPPER WAVE MOVING ACROSS THE AREA
LATE THIS EVENING WITH LIGHT RETURNS SHOWING UP ON RADAR. PIA
REPORTED 10 MINUTES OF LIGHT RAIN AND EXPECT THIS ACTIVITY WILL
REMAIN SUFFICIENT TO PRODUCE SOME SPRINKLES OR VERY LIGHT RAIN AND
WILL HAVE SLIGHT CHANCE POPS FOR THE REST OF THIS EVENING. BACK
EDGE OF THE CLOUD COVER NOW PUSHING INTO NORTHWEST IL AND EXPECT A
FEW HOURS OF MOSTLY CLEAR GOING INTO THE EARLY MORNING HOURS.
TEMPS HOLDING STEADY NEAR OR JUST ABOVE FREEZING WITH A FEW SITES
WARMING A DEGREE OR SO IN THE PAST FEW HOURS. CAN/T COMPLETELY
RULE OUT A CHANCE OF LIGHT FREEZING RAIN BUT GIVEN THE EXPECTED
LIGHT/SPOTTY NATURE OF THE PRECIP AND TEMPS AT OR ABOVE
FREEZING...NOT EXPECTING ANY SIGNIFICANT ICING CONCERNS.
SURFACE LOW OVER SOUTH CENTRAL IA WILL MOVE EAST/NORTHEAST TO THE
FAR SOUTHERN END OF LAKE MICHIGAN THURSDAY MORNING. AS IT DOES...
IT WILL TUG LOWER CLOUDS ACROSS SOUTHERN MN AND SOUTHERN WI SOUTH
ACROSS THE AREA...THUS CLEARING SHOULD BE RATHER SHORT LIVED. AS
THESE LOWER CLOUDS ARRIVE...THERE WILL LIKELY BE SOME PATCHY
DRIZZLE OR POTENTIALLY SOME LIGHT RAIN...BUT MODELS CONTINUE TO
DOWNPLAY PRECIP/QPF OVERNIGHT. ASSUMING THIS DRIZZLE OR VERY LIGHT
RAIN DOES MATERIALIZE...WILL NEED TO WATCH TEMP TRENDS ONCE CLOUDS
CLEAR TO SEE IF THEY DROP BACK TO NEAR FREEZING...THUS POTENTIAL
ICING CONCERNS...WHICH WOULD MAINLY BE ACROSS THE NORTHERN HALF OR
THIRD OF THE CWA. AT THIS POINT...WILL BE MAINTAINING AIR TEMPS AT
OR ABOVE FREEZING OVERNIGHT. CMS
&&
.SHORT TERM...
340 PM CST
THROUGH FRIDAY...
MAIN FORECAST CONCERNS ARE WITH PRECIP POTENTIAL AND TEMP TRENDS
TONIGHT...LINGERING LAKE EFFECT SNOW SHOWERS THURSDAY INTO EARLY
FRIDAY...AND POSSIBLE ACCUMULATING SNOW THIS WEEKEND.
RELATIVELY QUIET CONDITIONS THIS AFTERNOON...WITH INCREASING
MID/HIGH LEVEL CLOUD COVER OUT AHEAD OF APPROACHING SYSTEM OVER
THE CENTRAL PLAINS. SURFACE LOW OVER EASTERN NEBRASKA WILL
CONTINUE TO SHIFT EAST TOWARDS THE AREA THIS EVENING AS MID/UPPER
LEVEL TROUGH SWING EAST THROUGH THE CENTRAL CONUS. AS THIS
OCCURS...STRONG ISENTROPIC ASCENT OUT AHEAD OF IT WILL GRADUALLY
SHIFT EAST ACROSS THE CWA LATER THIS EVENING. INITIAL DRY
CONDITIONS IN PLACE WILL NEED TO BE OVERCOME THIS EVENING BUT
INCREASING ASCENT THIS EVENING SHOULD ALLOW FOR THE COLUMN TO
SATURATE...WITH DEVELOPING PRECIP TO THEN SPREAD OVER THE REGION.
GUIDANCE DOES VARY WITH REGARDS TO WHEN THE DRIER AIR WILL BE
OVERCOME...WITH SOME INDICATING THIS WILL OCCUR AS EARLY AS THIS
EVENING AND WITH OTHERS POINTING AT THE DEVELOPMENT AFTER THE
MIDNIGHT TIME FRAME. HAVE TRENDED TOWARDS THE PREVIOUS FORECAST
WITH THE POSSIBILITY OF PRECIP DEVELOPING BY MID TO LATE
EVENING...STRAYING AWAY FROM THE DRIER GUIDANCE. PERSISTENT
FORCING THROUGH THIS EVENING SHOULD ALLOW FOR AT LEAST LIGHT
DEVELOPMENT ACROSS A GOOD PORTION OF THE CWA. RAIN DOES APPEAR TO
BE THE PREDOMINANT PRECIP TYPE OVERNIGHT TONIGHT AS STRONG WARM
ADVECTION OUT AHEAD OF THIS SYSTEM OCCURS...AND ESPECIALLY AS
SOUTHERLY FLOW CONTINUES TO RAMP UP AHEAD OF THE SURFACE LOW.
HOWEVER...DO ANTICIPATE FOR SOME SLIGHT COOLING OF THE CURRENT MID
30 TEMPS LATE THIS AFTERNOON INTO THE EARLY EVENING BEFORE A
STEADY TEMP RISE IS OBSERVED FOR ALL AREAS. IF THE PRECIP WERE TO
OCCUR SLIGHTLY EARLIER THAN CURRENT THINKING...THEN A BETTER
CHANCE FOR LIGHT FREEZING RAIN COULD OCCUR. THIS TIME FRAME WOULD
BE IN THE 1-4Z PERIOD WHERE LOW TEMPS IN THE LOW 30S WILL BE
OBSERVED...BEFORE A RISE TO THE MID TO UPPER 30S WILL OCCUR. THIS
TEMP RISE SHOULD LIMIT ANY FREEZING RAIN POTENTIAL TO A SMALL
SEVERAL HOUR WINDOW...WITH ONCE AGAIN RAIN THEN EXPECTED EVEN INTO
EARLY THURSDAY MORNING.
EXPECT BEST DEVELOPMENT TO OCCUR MORE TOWARDS EARLY THURSDAY
MORNING INTO MID MORNING AS SURFACE LOW AND SURFACE BOUNDARIES
PUSH THROUGH...WITH THE RAIN BECOMING ALL SNOW THROUGH MID TO LATE
MORNING. PRECIP SHIELD SHOULD BE EXITING DURING THIS TRANSITION
WITH ANY SNOW ACCUMULATION EXPECTED TO NO MORE THAN A COUPLE OF
TENTHS OF AN INCH. LIGHT SNOW COULD LINGER INTO NORTHWEST INDIANA
AS LAKE EFFECT POTENTIAL INCREASES...BUT BETTER FOCUS WILL
INITIALLY BE FURTHER TO THE EAST. AS COLDER AIR SPILLS SOUTH AND
BOUNDARY LAYER FLOW SHIFTS...FOCUS FOR BETTER LAKE EFFECT SNOW
DEVELOPMENT WILL MOVE INTO THE CWA...WITH THE PORTER COUNTY AREA
WITHIN THE CWA LIKELY OBSERVING THIS BEST DEVELOPMENT. BUILDING
HIGH PRESSURE WITH BACKING LOW LEVEL FLOW WILL GRADUALLY HELP THIS
SNOW TO DIMINISH WHILE SHIFTING EAST THROUGHOUT THE DAY ON FRIDAY.
RODRIGUEZ
&&
.LONG TERM...
340 PM CST
FRIDAY NIGHT THROUGH WEDNESDAY...
MAIN CONCERN TO START THE PERIOD WILL BE FOR THE POTENTIAL FOR
ACCUMULATING SNOW SATURDAY NIGHT INTO SUNDAY. THERE STILL APPEARS
TO BE THE POTENTIAL FOR SNOW DURING THIS PERIOD...BUT WITH
CONFIDENCE OF THIS POTENTIAL FOR THE CWA LOWERING TODAY. PREVIOUS
CONSISTENCY AMONG VARYING GUIDANCE IS NOT PRESENT TODAY...WITH
GUIDANCE RANGING FROM LIGHT ACCUMULATIONS TO VERY LITTLE TO NONE.
AM NOT TOTALLY CONVINCED IN THE SHIFT WITH THE STORM TRACK AND
POTENTIAL PRECIP ADVERTISED TODAY AND DID NOT CHANGE POPS TOO MUCH
DURING THIS PERIOD...AS GUIDANCE COULD SHIFT BACK ONCE AGAIN.
WOULD LIKE TO SEE CONSISTENCY OF THIS POTENTIAL BEFORE POPS ARE
LOWERED. CURRENTLY HAVE THE HIGHEST POPS FOR THE SOUTHERN HALF OF
THE CWA...WITH A MORE FAVORED SOUTHERLY TRACK OF THIS SYSTEM.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* SOUTH-SOUTHEAST WINDS TURNING NORTHWEST BY 13Z WITH A BRIEF
PERIOD OF VARIABLE WINDS BECOMING MORE PROBABLE 10Z-13Z.
NORTHWEST GUSTS OF 30-35 KT FROM MID THURSDAY MORNING THROUGH
THE AFTERNOON.
* LOW MVFR CIGS AND MVFR VISIBILITY ARRIVING NEAR DAYBREAK AND
THEN POSSIBLY IFR FOR A FEW HOURS THURSDAY MORNING.
* A FEW RAIN SHOWERS AND DRIZZLE POSSIBLE PRIOR TO 13Z...THEN A
BRIEF PERIOD OF LIGHT RAIN/SNOW SHOWERS LIKELY MID-MORNING
THURSDAY.
//DISCUSSION...UPDATED 06Z...
LOW PRESSURE ACROSS SOUTHEAST IOWA AT 530Z WILL MOVE CLOSE TO MDW
AND GYY BY 12Z AND THEN ONTO LOWER MICHIGAN THROUGH THE REST OF
THURSDAY MORNING. BECAUSE OF THIS PATH...A TEMPORARY PERIOD OF
LIGHTER VARIABLE WINDS IS BECOMING MORE PROBABLE AT CHICAGO AREA
TAF SITES BETWEEN 10Z-13Z OR SO. BEHIND THE LOW PASSAGE ON
THURSDAY MORNING...THE WINDS WILL TURN TO THE NORTH-NORTHWEST AND
THEN NORTHWEST WITH SPEEDS QUICKLY INCREASING. OCCASIONAL GUSTS OF
30 TO 35 KT LOOK PROBABLE FOR DURING THE DAY THURSDAY.
SPOTTY LIGHT RAIN SHOWERS OR DRIZZLE WILL BE SEEN UNTIL THE STRONG
COLD ADVECTION ARRIVES. CIGS WILL ALSO DROP LOWER AS THE SYSTEM
CENTER PASSES. BASED ON UPSTREAM OBSERVATIONS...1000-1500 FT CIGS
ARE HIGHLY LIKELY WITH POTENTIAL FOR A PERIOD OF 600-900 FT CIGS
DURING THE MORNING. IN ADDITION...AS THE SYSTEM BEGINS TO
INTENSITY OVER LOW MICHIGAN...A BACKSIDE DEVELOPING AREA OF LIGHT
RAIN AND/OR SNOW IS EXPECTED TO MOVE CLOSE TO OR OVER THE TAF
SITES. THIS SHOULD LIKELY LAST NO LONGER THAN 90 MINUTES AT ANY
ONE SITE AND NO ACCUMULATION IS EXPECTED. MVFR CIGS ARE LIKELY TO
LAST INTO THURSDAY EVENING.
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* WHILE LOW ON SPECIFIC WIND DIRECTION 10Z-13Z...HIGH CONFIDENCE
THAT SPEEDS WILL BE LESS THAN 12 KT IN THAT PERIOD. HIGH
CONFIDENCE IN WINDS AFTER 13Z.
* HIGH IN MVFR CIGS AND TIMING. MEDIUM IN CIG BASES AND THAT A
BRIEF PERIOD OF IFR WILL OCCUR.
* MEDIUM IN PERIOD OF MVFR VISIBILITY THURSDAY MORNING.
* MEDIUM IN CHANCE FOR A BRIEF PERIOD OF MIXED PRECIP THURSDAY
MORNING. HIGH IN NO SNOW ACCUMULATION OCCURRING.
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
FRIDAY...VFR. NORTHWEST WINDS.
SATURDAY...CHANCE OF SNOW AND IFR DURING THE NIGHT. SOUTHWEST
WINDS.
SUNDAY...SNOW AND IFR LIKELY. NORTHEAST WINDS.
MONDAY...CHANCE OF SNOW WITH MVFR LIKELY. IFR POSSIBLE. NORTHWEST
WINDS.
TUESDAY...SLIGHT CHANCE OF SNOW DURING THE NIGHT. SOUTHWEST WINDS.
MTF/MDB
&&
.MARINE...
205 AM CST
A PROGRESSIVE ACTIVE PATTERN WILL CONTINUE ACROSS THE GREAT LAKES
REGION INTO THE BEGINNING OF FEBRUARY. MOVING EASTWARD EARLY THIS
MORNING IS AN ELONGATED TROUGH WITH TWO LOW PRESSURE CENTERS
COMPOSING IT...ONE PASSING JUST SOUTH OF LAKE MICHIGAN AND ANOTHER
OVER EASTERN LAKE SUPERIOR. TOGETHER THESE WILL CONSOLIDATE LATER
TODAY AND DRIVE MORE FOCUSED AND STRENGTHENING COLD ADVECTION
OVER LAKE MICHIGAN. THIS WITHIN THE STRONG AND ADVECTING PRESSURE
GRADIENT WILL SUPPORT NORTHWEST TO NORTH GALES...EVEN 45 KT GUST
POTENTIAL ACROSS PARTS OF THE NORTH. THE ILLINOIS AND ESPECIALLY
THE INDIANA NEAR SHORES SHOULD AT LEAST EXPERIENCE PERIODIC GALE
GUSTS INTO THIS EVENING. COLDER TEMPERATURES WILL BE WORKING
SOUTHWARD ACROSS THE LAKE LATER TODAY AND TONIGHT. SUPPORT FOR
HEAVY FREEZING SPRAY REMAINS OVER MAINLY THE NORTH AND CONTINUE
THE WARNING THERE. WAVES ARE LIKELY TO BUILD TO 12-15 FT TONIGHT
AT DOWNSTREAM FETCH LOCATIONS ON THE EASTERN HALF OF THE LAKE.
WINDS WILL GRADUALLY DIMINISH OVERNIGHT INTO FRIDAY MORNING AND
MORE QUICKLY AFTERWARD AS HIGH PRESSURE MOVES OVER THE LAKE.
BEYOND...THERE LOOKS LIKE OPPORTUNITIES FOR AT LEAST 30 KT WINDS
NEXT WEEK. ONE OF THESE IS BEHIND A COLD FRONT SATURDAY AFTERNOON
AND MORE SO SATURDAY NIGHT. MORE 30 KT WIND POTENTIAL WOULD COME
POSSIBLY TUESDAY AS RETURN SOUTHWEST FLOW SPREADS BACK OVER THE
LAKE.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 11 AM THURSDAY.
GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742-
LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878...11 AM THURSDAY TO 3 AM FRIDAY.
HEAVY FREEZING SPRAY WARNING...LMZ261-LMZ362-LMZ364-LMZ366-
LMZ563-LMZ565-LMZ567-LMZ868...2 PM THURSDAY TO 3 AM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
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WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1143 PM CST Wed Jan 28 2015
.UPDATE...
ISSUED AT 705 PM CST WED JAN 28 2015
00z/6pm surface analysis shows 1005mb low over western Iowa with
warm frontal boundary extending southward into Missouri.
Temperatures to the west of the warm front are currently in the
60s across Kansas/western Missouri, while readings further east
across central Illinois remain in the 30s and 40s. As the low
tracks into north-central Illinois, the warm front will push
eastward across the area this evening. While both the 00z KILX and
KDVN upper air soundings remain quite dry, latest radar mosaic
shows a narrow band of weak echoes developing ahead of the front.
High-res model output remains dry until the boundary pushes
further east into Indiana after midnight. Will however carry a
chance for sprinkles across the western half of the KILX CWA this
evening, then further east into east-central Illinois after
midnight as the boundary progresses across the area. Temperatures
will remain nearly steady or even rise a few degrees overnight as
gusty southeasterly winds gradually veer to the southwest. Once
the low pushes into Michigan, strong/gusty northwesterly winds
will develop by Thursday morning. In addition, low clouds
currently across the Dakotas will spill southward into the area.
May even see a few light rain/snow showers on the back side of the
departing system Thursday morning, particularly along/north of the
I-74 corridor.
&&
.SHORT TERM...(Tonight)
ISSUED AT 329 PM CST WED JAN 28 2015
A low pressure system currently centered over western Iowa will
track eastward across northern Illinois from around midnight to 6
a.m. tonight. As it does so, a warm frontal boundary followed by a
cold front will push across central Illinois in quick succession.
The warm front will cause temperatures to remain steady or even rise
slightly through much of the night, with primarily upper 30s and
lower 40s expected, followed by little increase in temperatures
after sunrise as the cold front pushes east across the area. This
system will be relatively moisture starved, so precipitation amounts
are expected to be very light. A potent surface pressure gradient
will be present with this system, keeping breezy winds going through
the night in the neighborhood of 15 to 20 mph with some higher
gusts. Winds will gradually turn from SSE this afternoon to SSW
overnight, shifting abruptly to northwest after the cold frontal
passage.
&&
.LONG TERM...(Thursday through Wednesday)
ISSUED AT 329 PM CST WED JAN 28 2015
Main concern today is the system over the weekend.
Morning upper air shows weak wave to move through tonight. Then
continued general northwest flow aloft as a cutoff low in the
southwest begins to drift to the east. A piece of shortwave energy
comes out from the southwest on Saturday and develops overrunning
pcpn Saturday night, as another wave in the northwest flow tracks to
the southeast into the area for Sunday. The result is a prolonged
period of light lift over the area Saturday night into Sunday
evening, which will produce light pcpn. Temperatures will be cold
enough for all over cwa but the far southeast to result in all snow
most of the period. At this time, lift seems to be light and just
the prolonged period from the 2 systems causing the pcpn. Will still
have to watch it as periods near to see if lift increases and thus
the resultant amounts. Kept amounts similar in the grids as previous
run at this time.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
ISSUED AT 1143 PM CST WED JAN 28 2015
Low pressure currently centered over eastern Iowa will track across
north-central Illinois tonight, then into Michigan by Thursday
morning. A tight pressure gradient ahead of the low will continue
to provide gusty southeasterly winds that will gradually veer to
the southwest after midnight, before veering sharply to the northwest
after FROPA between 12z and 15z Thu. Forecast soundings remain
quite dry, although models are hinting at perhaps a few light
showers near the low track, so have included VCSH at the I-74
terminals Thursday morning. VFR conditions will prevail until the
front passes and winds become northwesterly, at which time MVFR
ceilings currently over the Dakotas and western Iowa will spill
southeastward into the area. Based primarily on HRRR timing, have
introduced MVFR ceilings at KPIA by 10z, then further east to KCMI
by 13z. Once the low clouds arrive, they will stick around through
Thursday afternoon. Winds will be quite strong as well, with
northwesterly gusts in the 25 to 30kt range.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Barnes
SHORT TERM...Onton
LONG TERM...Goetsch
AVIATION...Barnes
AREA FORECAST DISCUSSION
NWS JACKSON KY
450 AM EST THU JAN 29 2015
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 400 AM EST THU JAN 29 2015
LATEST SURFACE MAP FEATURES HIGH PRESSURE ALONG THE EASTERN
CONUS...WITH LOW PRESSURE MOVING INTO THE GREAT LAKES AND OHIO VALLEY
REGIONS. ALOFT...A SHORT WAVE TROUGH IS ROTATING TOWARDS THE OHIO
VALLEY...WITH ANOTHER TROUGH DROPPING SOUTHEAST INTO THE NORTHERN
PLAINS...AND YET ONE MORE MOVING IN ACROSS SOUTH CENTRAL CANADA.
MAINLY MID AND HIGH LEVEL CLOUDS HAVE BEEN STREAMING IN ACROSS
EASTERN KENTUCKY. THE SOUTHERLY WIND FLOW OUT AHEAD OF THE
APPROACHING SURFACE LOW HAS ALLOWED FOR A NICE RIDGE/VALLEY SPLIT
ACROSS THE AREA...WITH MORE SHELTERED VALLEYS HOLDING IN THE LOW AND
MID 20S...WHILE RIDGETOPS ARE IN THE LOW TO MID 30S.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM...TAKING THE
LOW PRESSURE SYSTEM EAST ACROSS THE OHIO VALLEY DURING THE DAY...AND
ALLOWING THE ASSOCIATED SURFACE COLD FRONT TO MOVE THROUGH THE AREA
THIS AFTERNOON INTO EARLY THIS EVENING. MEANWHILE...THE MORE NORTHERN
SHORT WAVES WILL CONTINUE TO DROP SOUTHEAST IN SUCCESSION...HELPING
TO ESTABLISH A DEEP TROUGH ACROSS THE EAST BY FRIDAY.
THE CURRENT RADAR SHOWS A BAND OF LIGHT RAIN FROM SOUTH CENTRAL
INDIANA DOWN THROUGH WESTERN KENTUCKY. THE LATEST HRRR SHOWS THIS
ACTIVITY MAKING IT TO OUR DOORSTEP BY DAWN OR SHORTLY THEREAFTER...
ALTHOUGH THERE IS GOOD AGREEMENT THAT THE MAJORITY OF THE MEASURABLE
PRECIPITATION WILL STAY JUST NORTH...WITH MORE SPOTTIER ACTIVITY TO
CONTEND WITH ACROSS OUR AREA THROUGH 14Z. AFTER 14Z...PRECIPITATION
LOOKS TO BLOSSOM AS THE BETTER FORCING ARRIVES. HAVE BEEN CONCERNED
WITH THE COLD VALLEY READINGS ACROSS OUR AREA...HOWEVER IT LOOKS AS
THOUGH THAT BY THE TIME THE BETTER PRECIPITATION DOES MOVE IN...THAT
MOST LOCATIONS WILL BE ABOVE FREEZING. AS SUCH...WILL ISSUE A SPECIAL
WEATHER STATEMENT COVERING THE SPOTTIER PRECIPITATION AT ONSET...AS
MAINLY INTERIOR LOCATIONS WILL STILL LIKELY BE BELOW FREEZING. WILL
CONTINUE TO MONITOR TRENDS VERY CLOSELY OVER THE NEXT FEW HOURS SINCE
ANY RAMP UP IN THE PRECIPITATION WILL MEAN AN ICY COMMUTE POTENTIALLY.
ONCE THE FIRST BATCH OF PRECIP MOVES THROUGH LATER THIS MORNING INTO
EARLY THIS AFTERNOON...THERE WILL LIKELY BE A LULL IN THE
ACTIVITY...BEFORE THE COLDER AIR ARRIVES ON NORTHWEST WINDS AND THE
TROUGH AXIS MOVES THROUGH TONIGHT. THIS WILL ALLOW FOR SOME LIGHT
SNOW ACROSS THE AREA. SNOW SHOWERS WILL LIKELY LINGER IN THE EAST
THROUGH FRIDAY MORNING...BEFORE TAPERING OFF. ANY LIGHT ACCUMULATIONS
WILL FAVOR THE HIGHER TERRAIN IN THE FAR SOUTHEAST.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 446 AM EST THU JAN 29 2015
HIGH PRESSURE WILL TAKE HOLD OF SENSIBLE WEATHER TO BEGIN THIS
PERIOD. WHILE LOW PRESSURE THAT IS AFFECTING THE REGION TODAY
DEVELOPS INTO ANOTHER STRONG COASTAL LOW ACROSS THE NORTHEAST US.
THIS HIGH PRESSURE COUPLED WITH DECREASING CLOUDS WILL ALLOW FOR
DECOUPLING AND LOWS DROPPING DOWN INTO THE MID TO UPPER TEENS
AREA WIDE. THIS HIGH PRESSURE WILL ALLOW MOSTLY SUNNY SKIES EARLY IN
THE DAY FOR YOUR SATURDAY WITH INCREASING CLOUDS IN THE AFTERNOON.
WINDS WILL ALSO BECOME MORE SOUTHWEST BRINGING HIGHS ON SATURDAY INTO
THE UPPER 30S TO LOWER 40S.
NOW THE BIGGER CONCERN CONTINUES TO BE LATE WEEKEND STORM AND
CONFIDENCE REMAINS LOW IN REGARDS TO THIS SYSTEM. THE SETUP IS WE
HAVE A DEVELOPING UPPER LEVEL CLOSED LOW ACROSS THE NORTHERN BAJA
PENINSULA AND ASSOCIATED DEVELOPING SURFACE LOW SATURDAY MORNING.
MEANWHILE A UPPER LEVEL WAVE RIDES OVER RIDGING ACROSS THE NORTHWEST
US. THEN THIS IS WHERE THE MODELS CONTINUE TO STRUGGLE IS IN THE
PHASING PROCESS THAT OCCURS SATURDAY NIGHT IN THE UPPER LEVELS.
EARLIER THE 18Z/28 GFS AND 12Z/28 ECMWF HAD A MORE OPEN WAVE WHICH
TRANSLATED TO A WEAKER SURFACE LOW. THIS WAS NEW BASED ON THE
PREVIOUS RUNS SEEN OVER THE PAST COUPLE OF DAYS. THE LATEST 00Z/29
RUN OF THE GFS DEVELOPS A STRONGER LOW WITH A BIT OF A DEEPER TROUGH
SETTING UP. THE 00Z/29 ECMWF DOES HAVE SIMILARITIES...HOWEVER THE
SURFACE LOW PRESSURE IS NOT AS DEEP. ONE THING THAT REMAINS WITH BOTH
MODELS 00Z RUNS IS BOTH HAVE A GOOD AMT OF QPF RESPECTIVELY. ANOTHER
QUESTION THAT REMAINS IS HOW MUCH COLD AIR STAYS IN PLACE WITH THIS
SYSTEM ON SUNDAY AND THIS WILL DEPEND HEAVILY ON THE EVENTUAL TRACK
OF THIS SURFACE LOW. THAT SAID HAVE LEANED TOWARD A BIT COLDER
THROUGH THE DAY ON SUNDAY. THINKING STILL MUCH OF SUNDAY WOULD LEAD
TO MIXING ACROSS MUCH OF THE CWA WITH MORE IN THE WAY OF SNOW ACROSS
THE BLUEGRASS WHERE TEMPS REMAIN COOLER...HOWEVER CONFIDENCE IN THIS
SYSTEM REMAINS LOW GIVEN THE DRASTIC RUN TO RUN CHANGES SEEN IN THE
DETERMINISTIC MODELS. ALSO KEEPING IN MIND THAT THE ENSEMBLE MEAN HAS
BEEN QUITE ERRATIC AND GIVEN THAT THE 12 PERTURBATIONS IN OUR SYSTEM
ARE ERRATIC EXPLAINS THE LACK OF CONTINUITY. ALL THIS SAID STILL
THINK THERE IS A REASONABLE SHOT OF MEASURABLE SNOW SUNDAY INTO
MONDAY. ANOTHER PIECE TO THE PUZZLE TO KEEP IN MIND IS THAT A MORE
NORTHERLY TRACK SHOWN IN EARLIER RUNS COULD ALLOW FOR MORE SOUTHERLY
FLOW AND WARMER AIR AND LEAD TO LESSENING SNOWFALL TOTALS. ALTHOUGH
BEHIND THIS SYSTEM EXPECT COLD AIR TO FILTER INTO ALL OF THE CWA
SUNDAY NIGHT INTO MONDAY. ALSO WOULD EXPECT GENERALLY FALLING
TEMPERATURES DURING THE DAY ON MONDAY.
AFTER THIS THE AFOREMENTIONED LOW PRESSURE IS THEN FORECAST TO TRACK NE
AND CONTINUE TO DEEPEN ALONG NE ATLANTIC COAST. HIGH PRESSURE WILL
BUILD EAST MONDAY NIGHT AND EXPECT ANOTHER COLD NIGHT WITH GENERALLY
LOW TO MID TEENS ACROSS THE REGION. THESE TEMPS MAY HAVE TO BE
ADJUSTED FURTHER DEPENDING UPON IF WE RECEIVE MEASURABLE SNOW. THIS
HIGH PRESSURE WILL ADVANCE EAST OF THE REGION MOVING INTO THE DAY ON
TUESDAY BRINGING RETURN FLOW AND WELCOMING REBOUND IN
TEMPERATURE...WITH HIGHS IN THE MID TO UPPER 30S. THAT SAID WEDNESDAY
REMAINS UNCERTAIN WITH YET ANOTHER SYSTEM DEVELOPING AND AT THIS POINT
STUCK CLOSE TO THE BLEND. DID INTRODUCE MAINLY SLIGHT POPS DURING
THAT PORTION OF THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 219 AM EST THU JAN 29 2015
A PASSING COLD FRONT WILL BRING LOWERING CEILINGS...PRECIPITATION...
AND GUSTY SOUTH TO SOUTHWEST WINDS TO THE AREA THROUGH THURSDAY
EVENING. A STRONG LOW LEVEL JET DEVELOPING DURING THE OVERNIGHT HOURS
WILL ALSO ALLOW FOR LOW LEVEL WIND SHEAR BETWEEN 08 AND 14Z ACROSS
THE AREA. VFR CONDITIONS WILL LIKELY HOLD ON THROUGH THE EARLY
AFTERNOON...BEFORE CELINGS LIKELY COME DOWN QUICKLY TO MVFR/IFR ONCE
THE FRONT MOVES THROUGH THE AREA LATER THIS AFTERNOON INTO EARLY THIS
EVENING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GEOGERIAN
LONG TERM...DJ
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS JACKSON KY
400 AM EST THU JAN 29 2015
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 400 AM EST THU JAN 29 2015
LATEST SURFACE MAP FEATURES HIGH PRESSURE ALONG THE EASTERN
CONUS...WITH LOW PRESSURE MOVING INTO THE GREAT LAKES AND OHIO VALLEY
REGIONS. ALOFT...A SHORT WAVE TROUGH IS ROTATING TOWARDS THE OHIO
VALLEY...WITH ANOTHER TROUGH DROPPING SOUTHEAST INTO THE NORTHERN
PLAINS...AND YET ONE MORE MOVING IN ACROSS SOUTH CENTRAL CANADA.
MAINLY MID AND HIGH LEVEL CLOUDS HAVE BEEN STREAMING IN ACROSS
EASTERN KENTUCKY. THE SOUTHERLY WIND FLOW OUT AHEAD OF THE
APPROACHING SURFACE LOW HAS ALLOWED FOR A NICE RIDGE/VALLEY SPLIT
ACROSS THE AREA...WITH MORE SHELTERED VALLEYS HOLDING IN THE LOW AND
MID 20S...WHILE RIDGETOPS ARE IN THE LOW TO MID 30S.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM...TAKING THE
LOW PRESSURE SYSTEM EAST ACROSS THE OHIO VALLEY DURING THE DAY...AND
ALLOWING THE ASSOCIATED SURFACE COLD FRONT TO MOVE THROUGH THE AREA
THIS AFTERNOON INTO EARLY THIS EVENING. MEANWHILE...THE MORE NORTHERN
SHORT WAVES WILL CONTINUE TO DROP SOUTHEAST IN SUCCESSION...HELPING
TO ESTABLISH A DEEP TROUGH ACROSS THE EAST BY FRIDAY.
THE CURRENT RADAR SHOWS A BAND OF LIGHT RAIN FROM SOUTH CENTRAL
INDIANA DOWN THROUGH WESTERN KENTUCKY. THE LATEST HRRR SHOWS THIS
ACTIVITY MAKING IT TO OUR DOORSTEP BY DAWN OR SHORTLY THEREAFTER...
ALTHOUGH THERE IS GOOD AGREEMENT THAT THE MAJORITY OF THE MEASURABLE
PRECIPITATION WILL STAY JUST NORTH...WITH MORE SPOTTIER ACTIVITY TO
CONTEND WITH ACROSS OUR AREA THROUGH 14Z. AFTER 14Z...PRECIPITATION
LOOKS TO BLOSSOM AS THE BETTER FORCING ARRIVES. HAVE BEEN CONCERNED
WITH THE COLD VALLEY READINGS ACROSS OUR AREA...HOWEVER IT LOOKS AS
THOUGH THAT BY THE TIME THE BETTER PRECIPITATION DOES MOVE IN...THAT
MOST LOCATIONS WILL BE ABOVE FREEZING. AS SUCH...WILL ISSUE A SPECIAL
WEATHER STATEMENT COVERING THE SPOTTIER PRECIPITATION AT ONSET...AS
MAINLY INTERIOR LOCATIONS WILL STILL LIKELY BE BELOW FREEZING. WILL
CONTINUE TO MONITOR TRENDS VERY CLOSELY OVER THE NEXT FEW HOURS SINCE
ANY RAMP UP IN THE PRECIPTATION WILL MEAN AN ICY COMMUTE POTENTIALLY.
ONCE THE FIRST BATCH OF PRECIP MOVES THROUGH LATER THIS MORNING INTO
EARLY THIS AFTERNOON...THERE WILL LIKELY BE A LULL IN THE
ACTIVITY...BEFORE THE COLDER AIR ARRIVES ON NORTHWEST WINDS AND THE
TROUGH AXIS MOVES THROUGH TONIGHT. THIS WILL ALLOW FOR SOME LIGHT
SNOW ACROSS THE AREA. SNOW SHOWERS WILL LIKELY LINGER IN THE EAST
THROUGH FRIDAY MORNING...BEFORE TAPERING OFF. ANY LIGHT ACCUMULATIONS
WILL FAVOR THE HIGHER TERRAIN IN THE FAR SOUTHEAST.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 415 PM EST WED JAN 28 2015
QUITE AN ACTIVE PATTERN IN THE EXTENDED PERIOD WITH QUICK MOVING
S/WV TROUGHS OVER THE EASTERN US. THIS PERIOD BEGINS WITH YET
ANOTHER COASTAL LOW MOVING UP THE NEW ENGLAND COASTLINE... WITH
QUIET WEATHER ON THE HOMEFRONT. HIGH PRESSURE SETTLES INTO THE
REGION ON FRIDAY NIGHT INTO SATURDAY WITH RETURN FLOW FROM THE GULF
USHERING IN ADDITIONAL MOISTURE AHEAD OF THE NEXT SYSTEM.
THE END OF THE WEEKEND FEATURES A SYSTEM THAT STILL HAS A LOT OF
UNCERTAINTY TIED TO IT. THE BIG QUESTION IS HOW QUICKLY THE NORTHERN
AND SOUTHERN STREAM ENERGY PHASES TOGETHER...IF AT ALL... THE 12Z/28
GFS SHOWS A MORE LACKLUSTER SOLUTION WITH A WEAKER TROUGH WHEREAS
THE 00Z/28 ECMWF SHOWS THE ENERGY PHASING IN THE MIDWEST AND FORMING
A WELL-DEFINED LOW PRESSURE SYSTEM LIFTING UP ALONG THE NEW ENGLAND
COAST. BOTH SOLUTIONS INDICATE A RAIN TO SNOW CHANGEOVER EVENT FOR
EASTERN KENTUCKY SUNDAY NIGHT INTO MONDAY BUT THE ECMWF SOLUTION HAS
QUITE A BIT MORE ORGANIZED QPF ASSOCIATED WITH IT. AS OF RIGHT
NOW... THE MAJORITY OF THE PRECIP SHOULD FALL AS RAIN ON SUNDAY WHEN
THERE IS BETTER MOISTURE AND LIFT. THOUGH... GIVEN ALL OF THE
UNCERTAINTY... STILL THINK THERE IS POTENTIAL FOR ACCUMULATING SNOW
EARLY MONDAY MORNING SO THIS WILL HAVE TO BE MONITORED AND FINE
TUNED IN SUBSEQUENT FORECAST UPDATES.
TEMPERATURES ON MONDAY ARE EXPECTED TO GENERALLY DROP DURING THE DAY
AS COLD AIR CONTINUES TO PUSH IN BEHIND THE EXITING SYSTEM. HOW
QUICKLY THE SYSTEM EXITS WILL DETERMINE HOW MUCH AND HOW QUICKLY THE
TEMPERATURES WILL DROP. THAT BEING SAID... IT DOES APPEAR THAT WELL
BELOW NORMAL TEMPS WILL SETTLE INTO THE REGION WITH LOWS MONDAY
NIGHT DIPPING INTO THE MID AND UPPER TEENS. HIGH PRESSURE AND
SOUTHERLY FLOW RETURN TUESDAY HELPING TEMPERATURES RECOVER INTO
LOWER 30S. BY WEDNESDAY NIGHT ANOTHER SYSTEM LOOKS TO BRING ANOTHER
CHANCE FOR A MIXED PRECIP EVENT INTO THE DAY ON THURSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 219 AM EST THU JAN 29 2015
A PASSING COLD FRONT WILL BRING LOWERING CEILINGS...PRECIPITATION...
AND GUSTY SOUTH TO SOUTHWEST WINDS TO THE AREA THROUGH THURSDAY
EVENING. A STRONG LOW LEVEL JET DEVELOPING DURING THE OVERNIGHT HOURS
WILL ALSO ALLOW FOR LOW LEVEL WIND SHEAR BETWEEN 08 AND 14Z ACROSS
THE AREA. VFR CONDITIONS WILL LIKELY HOLD ON THROUGH THE EARLY
AFTERNOON...BEFORE CELINGS LIKELY COME DOWN QUICKLY TO MVFR/IFR ONCE
THE FRONT MOVES THROUGH THE AREA LATER THIS AFTERNOON INTO EARLY THIS
EVENING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GEOGERIAN
LONG TERM...JVM
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1203 AM CST THU JAN 29 2015
.UPDATE...
WENT AHEAD AND ISSUED A DENSE FOG ADVISORY FOR LOWER SE TX AND
FAR SW LA. VSBYS AT SE TX AIRPORTS HAVE ALREADY LOWERED TO ONE
QUARTER OF A MILE AND THESE CONDITIONS ARE EXPECTED TO PERSIST
THROUGH THE NIGHT. FOG HAS ALSO DEVELOPED ACRS SW LA...WITH VSBYS
CURRENTLY FLUCTUATING BUT EXPECTED TO LOWER TO AROUND 1/4 MILE AS
THE NIGHT PROGRESSES. CONDITIONS ARE EXPECTED TO IMPROVE BY MID-
MORNING THURSDAY. 24
&&
.PREV DISCUSSION... /ISSUED 1130 PM CST WED JAN 28 2015/
DISCUSSION...
FOR THE 29/06Z TAF ISSUANCE.
AVIATION...
SURFACE RIDGE IS EAST OF THE REGION WITH LIGHT SOUTHERLY WINDS
HELPING TO BRING SOME SHALLOW MOISTURE BACK INTO THE REGION. SHORT
WAVE PRODUCING SOME HIGH LEVEL CLOUDS HAVE PUSHED OFF TO THE EAST
ALSO LEAVING BEHIND CLEAR SKIES. WITH THE CLEAR SKIES AND LIGHT
WINDS...AIR TEMPERATURES SHOULD COOL TO DEW POINTS WITH SOME FOG
FORMATION...ESPECIALLY OVER SOUTHEAST TEXAS AND SOUTHWEST
LOUISIANA WHERE AIR TEMPERATURES HAVE ALREADY COOLED BELOW WHAT
THE EVENING DEW POINTS WERE...AND WITH THAT...VISIBILITY DOWN TO
LIFR AT KBPT AND BOUNCING BETWEEN MVFR/IFR AT KLCH. EXPECT KBPT TO
EXPERIENCE LIFR CONDITIONS FOR THE OVERNIGHT INTO EARLY THURSDAY
MORNING...WITH KLCH ALSO SETTLING IN FOR MAINLY LIFR CONDITIONS
AFTER 29/09Z. THE OTHER TAF SITES THAT HAVE SEEN LESS RETURN FLOW
MOISTURE WILL LIKELY EXPERIENCE MVFR CONDITIONS OVERNIGHT...WITH
THE BRIEF POSSIBILITY OF IFR. WITH INCREASING WINDS AND DAYTIME
HEATING...ANY FOG SHOULD LIFT BY 29/15Z...WITH VFR CONDITIONS
PREVAILING FOR THE REMAINDER OF THE DAY. A WEAK COLD FRONT WILL
MOVE THROUGH AT THE END OF THE TAF PERIOD WITH A SWITCH TO
NORTHWEST WINDS AND CLOUD DECK AROUND 5K FEET MOVING WITH THE
FRONT.
RUA
PREV DISCUSSION... /ISSUED 950 PM CST WED JAN 28 2015/
DISCUSSION...
A QUIET NIGHT UNDERWAY WITH HIGH PRES EAST OF THE
REGION...ALLOWING SELY WINDS TO BRING INCREASING LOW LVL MOISTURE
OVER THE AREA. DEWPOINTS ACRS SW LA AND SE TX ARE IN THE LOWER
50S WITH MIDDLE AND UPPER 40S ACRS ERN PORTIONS OF THE AREA.
OVERNIGHT LOWS ARE EXPECTED TO RUN ABOUT 5-10 DEGREES WARMER THAN
LAST NIGHT WITH LOWS IN THE LOWER TO MIDDLE 50S ACRS ALL BUT THE
ERN-MOST ZONES WHERE TEMPERATURES WILL BE IN THE UPPER 40S/NR 50.
WITH LT WINDS ACRS THE AREA AND DEWPOINT DEPRESSIONS
NARROWING...FOG SHOULD BEGIN DEVELOPING BY MIDNIGHT. FOG IS
EXPECTED TO BEGIN DEVELOPING ACRS LOWER SE TX/SW LA INITIALLY...THEN
INCREASE IN COVERAGE FURTHER NORTH AND EAST ACRS THE AREA THROUGH
THE NIGHT. SREF PROBABILITIES AS WELL AS NAM AND HRRR GUIDANCE
INDICATE THE POTENTIAL FOR VISIBILITIES LESS THAN ONE MILE...AND
DENSE FOG COULD BE POSSIBLE IN A FEW LOCATIONS. WILL CONTINUE TO
MONITOR TRENDS FOR THE POSSIBILITY OF A DENSE FOG ADVISORY.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 52 72 47 59 / 0 0 10 10
KBPT 55 72 50 61 / 0 10 10 10
KAEX 51 72 43 58 / 0 0 10 0
KLFT 50 74 48 60 / 0 0 10 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...DENSE FOG ADVISORY UNTIL 8 AM CST THURSDAY FOR CALCASIEU-WEST
CAMERON.
TX...DENSE FOG ADVISORY UNTIL 8 AM CST THURSDAY FOR HARDIN-JEFFERSON-
ORANGE-SOUTHERN JASPER-SOUTHERN NEWTON.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1130 PM CST WED JAN 28 2015
.DISCUSSION...
FOR THE 29/06Z TAF ISSUANCE.
&&
.AVIATION...
SURFACE RIDGE IS EAST OF THE REGION WITH LIGHT SOUTHERLY WINDS
HELPING TO BRING SOME SHALLOW MOISTURE BACK INTO THE REGION. SHORT
WAVE PRODUCING SOME HIGH LEVEL CLOUDS HAVE PUSHED OFF TO THE EAST
ALSO LEAVING BEHIND CLEAR SKIES. WITH THE CLEAR SKIES AND LIGHT
WINDS...AIR TEMPERATURES SHOULD COOL TO DEW POINTS WITH SOME FOG
FORMATION...ESPECIALLY OVER SOUTHEAST TEXAS AND SOUTHWEST
LOUISIANA WHERE AIR TEMPERATURES HAVE ALREADY COOLED BELOW WHAT
THE EVENING DEW POINTS WERE...AND WITH THAT...VISIBILITY DOWN TO
LIFR AT KBPT AND BOUNCING BETWEEN MVFR/IFR AT KLCH. EXPECT KBPT TO
EXPERIENCE LIFR CONDITIONS FOR THE OVERNIGHT INTO EARLY THURSDAY
MORNING...WITH KLCH ALSO SETTLING IN FOR MAINLY LIFR CONDITIONS
AFTER 29/09Z. THE OTHER TAF SITES THAT HAVE SEEN LESS RETURN FLOW
MOISTURE WILL LIKELY EXPERIENCE MVFR CONDITIONS OVERNIGHT...WITH
THE BRIEF POSSIBILITY OF IFR. WITH INCREASING WINDS AND DAYTIME
HEATING...ANY FOG SHOULD LIFT BY 29/15Z...WITH VFR CONDITIONS
PREVAILING FOR THE REMAINDER OF THE DAY. A WEAK COLD FRONT WILL
MOVE THROUGH AT THE END OF THE TAF PERIOD WITH A SWITCH TO
NORTHWEST WINDS AND CLOUD DECK AROUND 5K FEET MOVING WITH THE
FRONT.
RUA
&&
.PREV DISCUSSION... /ISSUED 950 PM CST WED JAN 28 2015/
DISCUSSION...
A QUIET NIGHT UNDERWAY WITH HIGH PRES EAST OF THE
REGION...ALLOWING SELY WINDS TO BRING INCREASING LOW LVL MOISTURE
OVER THE AREA. DEWPOINTS ACRS SW LA AND SE TX ARE IN THE LOWER
50S WITH MIDDLE AND UPPER 40S ACRS ERN PORTIONS OF THE AREA.
OVERNIGHT LOWS ARE EXPECTED TO RUN ABOUT 5-10 DEGREES WARMER THAN
LAST NIGHT WITH LOWS IN THE LOWER TO MIDDLE 50S ACRS ALL BUT THE
ERN-MOST ZONES WHERE TEMPERATURES WILL BE IN THE UPPER 40S/NR 50.
WITH LT WINDS ACRS THE AREA AND DEWPOINT DEPRESSIONS
NARROWING...FOG SHOULD BEGIN DEVELOPING BY MIDNIGHT. FOG IS
EXPECTED TO BEGIN DEVELOPING ACRS LOWER SE TX/SW LA INITIALLY...THEN
INCREASE IN COVERAGE FURTHER NORTH AND EAST ACRS THE AREA THROUGH
THE NIGHT. SREF PROBABILITIES AS WELL AS NAM AND HRRR GUIDANCE
INDICATE THE POTENTIAL FOR VISIBILITIES LESS THAN ONE MILE...AND
DENSE FOG COULD BE POSSIBLE IN A FEW LOCATIONS. WILL CONTINUE TO
MONITOR TRENDS FOR THE POSSIBILITY OF A DENSE FOG ADVISORY.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 53 71 45 59 42 / 0 10 10 10 10
KBPT 55 72 47 59 43 / 0 10 10 10 10
KAEX 51 72 43 56 38 / 0 0 10 0 10
KLFT 50 74 46 58 42 / 0 0 10 10 0
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
458 AM EST THU JAN 29 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 457 AM EST THU JAN 29 2015
WV AND LATEST RADAR IMAGERY SHOW IT WELL...THE DEEP MOISTURE SET UP
ACROSS CENTRAL UPPER MI IS QUICKLY EXITING E. THE SFC TROUGH SET UP
OVER W LAKE SUPERIOR AROUND 09Z THIS MORNING WILL EDGE TO THE E HALF
OF THE CWA SHORTLY AFTER DAYBREAK THIS IS WHEN WE WILL REALLY BEGIN
TO NOTICE SOME OF THOSE STRONGER N-NNW WINDS BEGIN /WINDS CURRENTLY
AROUND 12KTS AT CMX WILL BEGIN TO GUSTS 25-30KTS/.
-FZDZ HAS BEEN REPORTED OFF AND ON THIS MORNING AS THE MAIN BULK OF
MOISTURE EXISTS OVER CENTRAL AND E UPPER MI...AS STRONG HIGH
PRESSURE OVER CENTRAL SASKATCHEWAN NEARS. UTILIZED THE PROBABILITY
OF ICE PRESENT FROM THE RUC TO GET A BETTER HANDLE ON WHEN AND WHERE
-FZDZ MAY SET UP BEFORE COLD AIR PUSHES ACROSS ALL OF UPPER MI
/BASICALLY BY 18Z/ FOR ANY LINGERING MIXED PRECIP TO TRANSITION BACK
TO JUST -SHSN. LOOK FOR FALLING TEMPS THIS AFTERNOON AS THE COLDER
AIR SLIDES IN. 850MB TEMPS AROUND -10C EARLY THIS MORNING WILL FALL
THIS AFTERNOON...AND GET DOWN TO AROUND -17C BY 00Z...AND -20C BY
06Z FRIDAY. THE ARRIVAL OF THE COLDER AIR WILL BRING A BETTER CHANCE
OF LAKE EFFECT SNOW SHOWERS TO UPSLOPE LOCATIONS OVER THE W FAVORED
BY NNW WINDS.
LIMITING FACTORS FOR SIGNIFICANT SNOW ACCUMULATIONS OVER THE W THIRD
OF THE CWA LATER THIS AFTERNOON THROUGH THIS EVENING WILL BE THE
LOWERING DGZ TO AROUND 4KFT OR LESS BY 06Z FRIDAY...WINDS STILL
GUSTING 15-20KTS WILL KEEP SLR VALUES FROM RISING BACK UP TO
25:1 TOO FAST. HOWEVER...WITH THE 500MB TROUGH OVERHEAD AND AN
ADDITIONAL SHORTWAVE SLIDING THROUGH LATE THIS AFTERNOON THROUGH
THIS EVENING...SOME ENHANCEMENT IS EXPECTED. WILL KEEP SNOW AMOUNTS
AROUND 2IN OR LESS ACROSS THE W THIRD OF THE CWA.
ONE CONCERN FOR THE EVENING PERIOD WILL BE THE POTENTIAL OF A MESO
LOW SETTING UP OVER S CENTRAL LAKE SUPERIOR AFTER 03Z...KEEPING A
BAND OF MORE MODERATE SNOW OVER CENTRAL/E MARQUETTE COUNTY
AND W ALGER COUNTY. THE NAM AND REGIONAL WRF HIGHLIGHT THE
POTENTIAL. HAVE EXPANDED SNOW FARTHER W TO ACCOUNT FOR THIS...AS
WELL AS KEPT THE WINDS UP OVER S CENTRAL LAKE SUPERIOR A BIT LONGER
/WHICH SEEMS TO HAVE BEEN ALREADY ACCOUNTED FOR/. ENHANCED BY THE
WINDS GUSTING 25-35KTS...VISIBILITY RESTRICTIONS WILL BE A CONCERN
FOR THOSE TRAVELING ON M-28. EVEN WITHOUT ANY LAKE ENHANCEMENT
BLOWING AND DRIFTING SNOW COULD BE AN ISSUE...DEPENDING ON HOW SOLID
SNOW BANKS ON THE SIDE OF THE ROAD HAVE BECOME AND HOW MUCH SNOW HAS
BEEN ABLE TO ACCUMULATE ON THE ICE ALONG LAKE SUPERIOR.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 411 AM EST THU JAN 29 2015
FCST FOCUS IN THE MEDIUM AND EXTENDED RANGE WL BE ON THE IMPACT OF
SEVERAL CLIPPER TYPE SHRTWVS THAT ARE FCST TO MOVE THRU A MEAN UPR
TROF IN ERN NAMERICA. UNDER THE PERSISTENT NW FLOW ALOFT...EXPECT
BLO TO WELL BLO NORMAL TEMPS TO DOMINATE DURING THIS TIME WITH A
STEADY FEED OF CNDN AIR. WITH THE COLD AIR SURGES...LES WL BE AN
OBVIOUS CONCERN.
FRI...SFC HI PRES IS FCST TO SHIFT FM OVER MN TOWARD THE OH RIVER
VALLEY BE 00Z SAT. AS NW WINDS IN THE MRNG BACK TO THE W AND THEN
THE SW LATE...LINGERING LES OVER THE W WL BECOME CONFINED TO OVER
THE KEWEENAW AND END OVER THE E EXCEPT NEAR THE SHORE E OF GRAND
MARAIS TOWARD 00Z SAT. ALTHOUGH THE LK CLDS WL BE SHIFTING
OFFSHORE...MORE MID/HI CLDS IN ADVANCE OF ANOTHER SHRTWV MOVING SE
WITHIN THE NW FLOW ALF WL BE PUSHING INTO THE UPR LKS.
FRI NGT/SAT...SHRTWV EMBEDDED IN THE NW FLOW ALOFT WL BE MOVING INTO
NW MN AT 00Z SAT AND IS THEN FCST TO SLIDE SE THRU NCENTRAL WI BY
12Z SAT AND THEN ACROSS LOWER MI ON SAT. AT THE SAME TIME...ANOTHER
STRONGER SHRTWV WL BE MOVNG FM CENTRAL CANADA INTO FAR NW ONTARIO BY
12Z SAT BEFORE MOVING TO JUST S OF JAMES BAY BY 00Z SUN. UPR MI WL
BE IMPACTED MAINLY BY THE WEAKER SRN DISTURBANCE. ALTHOUGH A BAND OF
RELATIVELY WEAK QVECTOR CNVGC IS FCST TO SLIDE ACROSS UPR MI ON FRI
NGT INTO SAT MRNG ON THE CYC SIDE OF THIS SRN SHRTWV...ACCOMPANYING
ISENTROPIC ASCENT/MSTR INFLOW IS FCST TO BE RELATIVELY WEAK. SO WL
FCST ONLY CHC POPS OVER MOST OF THE CWA AND MAINLY BTWN 03Z SAT AND
15-18Z SAT...WHEN THE FORCING ACCOMPANYING THE SRN SHRTWV AND A COLD
FNT ATTENDANT TO THE NRN SHRTWV ARE FCST TO EXIT THE ERN CWA AND
GIVE WAY TO SOME VIGOROUS DEEP LYR QVECTOR DVGC. MAINTAINED SOME
LIKELY POPS OVER THE NRN TIER OF THE CWA CLOSE TO THE STRONGER NRN
SHRTWV AND WHERE SHARPER LLVL CNVGC WL ACCOMPANY THE SAT COLD FROPA.
THE COLDEST 00Z GFS/12Z ECMWF RUNS SHOW H85 TEMPS IN THE WAKE OF THE
SAT COLD FROPA PLUNGING AS LO AS -25C BY 00Z SUN...BUT QUICK
TRANSITION TO A MORE DIFFLUENT/ACYC H925 N FLOW AND INVRN BASE
FALLING TO H85-875 WL TEND TO LIMIT LES INTENSITY. RELATIVELY
MODERATE TEMPS INTO SAT MRNG WL FALL THRU THE AFTN AS THE COLDER AIR
SURGES INTO THE AREA IN THE STEADY N FLOW AHEAD OF ARCTIC HI PRES
BLDG SEWD IN SCENTRAL CANADA.
SAT NGT THRU SUN NGT...UPR MI WL REMAIN DOMINATED BY A COLD N
BACKING WNW LLVL FLOW OF ARCTIC AIR ASSOCIATED WITH ARCTIC HI PRES
MOVING FM OVER ALBERTA/SASKATCHEWAN AT 00Z SUN INTO THE UPR MS RIVER
VALLEY BY 12Z MON. EXPECT TEMPS TO RUN WELL BLO NORMAL AND LES TO
CONTINUE NEAR LK SUP WITH H85 TEMPS FCST TO REMAIN NOT FAR FM -22C
TO -25C. SAT NGT COULD BE PARTICULARLY CHILLY OVER THE E WITH THE N
H925 FLOW ALLOWING SOME DRAINAGE OF COLD AIR INTO THAT AREA OFF
ONTARIO. ALTHOUGH FCST ACYC NATURE OF THE H925 FLOW AND NEAR ABSENCE
OF THE DGZ ASSOCIATED WITH THE VERY LO H85 TEMPS WL LIMIT LES
AMOUNTS...SOME OF THE MODELS HINT THERE MAY BE SOME ENHANCED CNVGC
ALONG A LK INDUCED TROF STRETCHING FM THE KEWEENAW TOWARD WHITEFISH
PT THAT WL INTENSIFY AS THE LARGER PRES GRADIENT RELAXES AND A
SHRTWV EMBEDDED IN THE NW FLOW APRCHS ON SUN/SUN NGT. RAISED POPS
WELL ABOVE THE CONSENSUS TO LIKELY ALONG THIS AXIS.
MON...LES ALONG THE LK INDUCED TROF WL BEGIN TO DIMINISH/SHIFT OUT
INTO LK SUP WITH THE APRCH OF A SFC RDG AXIS EXTENDING N FM THE HI
CENTER SHIFTING TOWARD THE OH VALLEY AND THE ASSOCIATED BACKING LLVL
FLOW. BUT THE MORE W WIND COMPONENT WL MEAN LESS LK MODERATION AND
PERSISTENT WELL BLO NORMAL SFC TEMPS EVEN AS THE H85 TEMPS MODERATE
A BIT FASTER.
TUE/WED...THE LONGER RANGE GUIDANCE HINTS ANOTHER CLIPPER TYPE
DISTURBANCE WL PASS THRU THE UPR LKS ON TUE...WITH H85 TEMPS
REBOUNDING TO NEAR -15C IN THE WAA BTWN THIS FEATURE AND HI PRES
MOVING INTO THE MID ATLANTIC. BUT ANOTHER ARCTIC SURGE LOOKS TO
FOLLOW ON WED AS THE SHRTWV PASSAGE REAMPLIFIES THE ERN TROF AND THE
NW FLOW IN ADVANCE OF THE NEXT CNDN HI SINKING INTO THE NRN PLAINS
ADVECTS H85 TEMPS AS LO AS -25 TO -28C INTO THE UPR LKS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1154 PM EST WED JAN 28 2015
DISTURBANCE APPROACHING TONIGHT WILL BRING SOME -SN/DETERIORATING
CONDITIONS. ALL TERMINALS WILL LIKELY FALL TO IFR WITH A FEW HRS OF
LIFR POSSIBLE OVERNIGHT. THERE MAY BE A LITTLE
-FZDZ LATE TONIGHT AT KIWD. PASSAGE OF COLD FRONT
EARLY THU MORNING WILL BRING INCREASING...GUSTY NW
WINDS...ESPECIALLY AT THE MORE EXPOSED KCMX TERMINAL.
OTHERWISE...EXPECT IMPROVEMENT TO MVFR AT ALL TERMINALS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 AM EST THU JAN 29 2015
LOW PRESSURE SYSTEM NEAR N LAKE SUPERIOR THIS MORNING WILL MOVE INTO
QUEBEC THIS AFTERNOON WHILE ANOTHER LOW NEAR CHICAGO SHIFTS EAST
INTO NEW ENGLAND ON FRIDAY MORNING. MEANWHILE...A HIGH OVER S
CENTRAL CANADA WILL MOVE SE INTO MN ON FRIDAY. IN BETWEEN THE
EXITING LOW AND NEARING HIGH...STRONG N-NNW GALES GUSTING 35 TO
AROUND 40KTS WILL DEVELOP THIS AFTERNOON OVER MAINLY CENTRAL AND E
LAKE SUPERIOR. LOOK FOR WINDS TO SLOWLY DIMINISH LATE THIS EVENING
AND OVERNIGHT...WITH GUSTS REMAINING 25-30KTS THROUGH DAYBREAK
FRIDAY. GIVEN THE STRONG WINDS...AND COLDER AIR SURGING IN...HEAVY
FREEZING SPRAY WILL BE POSSIBLE OVER THIS SAME AREA INTO EARLY
FRIDAY MORNING. WINDS WILL THEN QUICKLY DIMINISH AND REMAIN LESS
THAN 30KTS THROUGH FRIDAY NIGHT.
AS THIS HIGH DRIFTS INTO THE OH RIVER VALLEY ON SATURDAY...A TROUGH
WILL SLIDE ACROSS THE UPPER GREAT LAKES. A FEW N TO NW GUSTS OF 30
TO NEAR 35KTS WILL BE POSSIBLE SATURDAY AFTERNOON AND EVENING.
EXPECT HIGH PRESSURE OVER CENTRAL CANADA ON SATURDAY TO MOVE SE INTO
THE N PLAINS ON SUNDAY...AND THE MID MS RIVER VALLEY ON MONDAY.
WINDS SHOULD DIMINISH FOR A TIME SUN BEFORE INCREASING AGAIN MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 7 AM
EST FRIDAY FOR LSZ264-266-267.
GALE WARNING FROM 1 PM THIS AFTERNOON TO 4 AM EST FRIDAY FOR
LSZ267.
GALE WARNING FROM 10 AM THIS MORNING TO 4 AM EST FRIDAY FOR
LSZ265-266.
GALE WARNING UNTIL 1 AM EST FRIDAY FOR LSZ263-264.
HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 1 AM
EST FRIDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KF
LONG TERM...KC
AVIATION...07
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
412 AM EST THU JAN 29 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 444 PM EST WED JAN 28 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A PAIR OF SHORTWAVES TO
THE W AND NW. ONE IS MOVING OUT OF WY/CO INTO THE WRN PLAINS AND THE
OTHER IS MOVING FROM SRN SASKATCHEWAN INTO SRN MANITOBA. AHEAD OF
THESE FEATURES...A RIBBON OF STRENGTHENING WAA/ISENTROPIC ASCENT IS
SPREADING ESE ACROSS NRN ONTARIO AND THE UPPER GREAT LAKES
UNDERNEATH RIGHT ENTRANCE OF UPPER JET CURVING FROM NRN ONTARIO DOWN
THRU THE CNTRL APPALACHIANS. REGIONAL RADARS SHOW A STREAK OF RADAR
RETURNS EXTENDING ESE FROM SE MANITOBA ACROSS ADJACENT NRN ONTARIO
AND OVER LAKE SUPERIOR/ERN UPPER MI. THE ASCENT HAS BEEN SUFFICIENT
TO ERODE DRY AIR AT THE LOWER LEVELS AND ALLOW SOME -SN TO REACH THE
GROUND FROM THE TIP OF THE KEWEENAW INTO THE NCNTRL AND ERN FCST
AREA.
PAIR OF SHORTWAVES WILL CONTINUE MOVING ESE TONIGHT WITH THE NRN
STREAM WAVE THE MORE IMPORTANT FEATURE FOR THE WEATHER HERE. AS THE
WAVE APPROACHES...ISENTROPIC ASCENT ON THE 295K SFC INCREASES
TONIGHT...MOST NOTABLY OVER THE E HALF OF UPPER MI. WHILE IT WILL BE
TOO WARM FOR ANY LAKE ENHANCEMENT OFF LAKE MICHIGAN...THE FLOW OFF
THE LAKE WILL STILL AID THE MOISTENING OF THE LOW LEVELS. OVER THE
W...THE WINDOW OF COLUMN MOISTENING IS SHORTER BEFORE THE ISENTROPIC
ASCENT DEPARTS OVERNIGHT. THUS...PCPN AMOUNTS TONIGHT WILL BE
LIGHTEST OVER THE W AND GREATER OVER THE E. 295K SFC SHOWS MIXING
RATIOS OF 3-4G/KG AVBL...SUGGESTING THE POTENTIAL FOR 3-4INCHES OF
SNOW FOR THE ROUGHLY 6HRS OF ASCENT EXPECTED. 4 INCHES IS LIKELY TOO
HIGH SINCE SNOW TO WATER RATIOS SHOULD BE ON THE LOWER SIDE. AS IT
IS...WILL PROBABLY BE CLOSE TO ADVY THRESHOLD OVER THE FAR E...
MAINLY LUCE COUNTY...AS 12HR SNOW ACCUMULATIONS FROM LATE EVENING TO
LATE THU MORNING WILL BE NEAR 3 INCHES. SNOW ACCUMULATIONS WILL BE
STEADILY LIGHTER TO THE W...DOWN TO LESS THAN 1 INCH FAR W AND ALONG
THE WI BORDER. LATE TONIGHT INTO THU MORNING...FCST SOUNDINGS
SUPPORT THE POTENTIAL FOR SOME -FZDZ AS MID LEVEL MOISTURE/SYNOPTIC
SNOW EXIT...LEAVING A LOW LEVEL MOIST LAYER THAT HAS TEMPS HIGHER
THAN -10C. WILL INCLUDE MENTION OF -FZDZ WHERE WINDS WILL BE
UPSLOPING.
COLD FRONT PASSES ACROSS UPPER MI THU MORNING. DESPITE INCREASING
WIND FIELDS...INITIAL CAA IS WEAK AS THERMAL GRADIENT IS DISPLACED
OFF TO THE NW...BUT CAA INCREASES QUICKLY IN THE AFTN. 850MB TEMPS
AROUND -10C IN THE MORNING WILL FALL TO NEAR -20C BY 00Z FRI...AND
THIS WILL RESULT IN FALLING SFC TEMPS...ESPECIALLY IN THE AFTN. LAST
OF THE SYNOPTIC SNOW WILL END OVER THE E IN THE MORNING.
OTHERWISE...THERE MAY NOT BE TOO MUCH IN THE WAY OF PCPN (-SN/-FZDZ)
DURING THE MORNING AWAY FROM AREAS THAT SEE UPSLOPING UNDER NW
WINDS. AS COLDER AIR ARRIVES IN THE AFTN...NW/NNW FLOW LES WILL
INCREASE IN COVERAGE WITH DGZ DROPPING INTO THE CONVECTIVE LAYER.
STRONG SUBSIDENCE/DEEP LAYER QVECTOR DIVERGENCE WILL LIMIT LES
INTENSITY. SO FOR THE MOST PART...EXPECT ACCUMULATIONS MOSTLY AROUND
1 INCH IN THE AFTN. STRONG WINDS WILL DISPLACE LES A LITTLE FARTHER
INLAND THAN NORMAL. SPEAKING OF WINDS...FAVORABLE POSTIONING OF PRES
RISE/FALL COUPLET WILL RESULT IN AN ADDITIVE ISALLOBARIC WIND
COMPONENT. COMBINED WITH 925MB WINDS INCREASING TO AROUND
40KT...CONDITIONS WILL BECOME BLUSTERY ACROSS THE AREA. ALONG THE
LAKE SUPERIOR SHORE AROUND THE TIP OF THE KEWEENAW AND FROM BIG BAY
EASTWARD...WINDS WILL PROBABLY GUST TO 35 TO 45 MPH IN THE AFTN.
DEPENDING ON HOW QUICKLY LES INCREASES IN THE AFTN...BLSN COULD
BECOME A SIGNIFICANT ISSUE NEAR THE LAKE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 411 AM EST THU JAN 29 2015
FCST FOCUS IN THE MEDIUM AND EXTENDED RANGE WL BE ON THE IMPACT OF
SEVERAL CLIPPER TYPE SHRTWVS THAT ARE FCST TO MOVE THRU A MEAN UPR
TROF IN ERN NAMERICA. UNDER THE PERSISTENT NW FLOW ALOFT...EXPECT
BLO TO WELL BLO NORMAL TEMPS TO DOMINATE DURING THIS TIME WITH A
STEADY FEED OF CNDN AIR. WITH THE COLD AIR SURGES...LES WL BE AN
OBVIOUS CONCERN.
FRI...SFC HI PRES IS FCST TO SHIFT FM OVER MN TOWARD THE OH RIVER
VALLEY BE 00Z SAT. AS NW WINDS IN THE MRNG BACK TO THE W AND THEN
THE SW LATE...LINGERING LES OVER THE W WL BECOME CONFINED TO OVER
THE KEWEENAW AND END OVER THE E EXCEPT NEAR THE SHORE E OF GRAND
MARAIS TOWARD 00Z SAT. ALTHOUGH THE LK CLDS WL BE SHIFTING
OFFSHORE...MORE MID/HI CLDS IN ADVANCE OF ANOTHER SHRTWV MOVING SE
WITHIN THE NW FLOW ALF WL BE PUSHING INTO THE UPR LKS.
FRI NGT/SAT...SHRTWV EMBEDDED IN THE NW FLOW ALOFT WL BE MOVING INTO
NW MN AT 00Z SAT AND IS THEN FCST TO SLIDE SE THRU NCENTRAL WI BY
12Z SAT AND THEN ACROSS LOWER MI ON SAT. AT THE SAME TIME...ANOTHER
STRONGER SHRTWV WL BE MOVNG FM CENTRAL CANADA INTO FAR NW ONTARIO BY
12Z SAT BEFORE MOVING TO JUST S OF JAMES BAY BY 00Z SUN. UPR MI WL
BE IMPACTED MAINLY BY THE WEAKER SRN DISTURBANCE. ALTHOUGH A BAND OF
RELATIVELY WEAK QVECTOR CNVGC IS FCST TO SLIDE ACROSS UPR MI ON FRI
NGT INTO SAT MRNG ON THE CYC SIDE OF THIS SRN SHRTWV...ACCOMPANYING
ISENTROPIC ASCENT/MSTR INFLOW IS FCST TO BE RELATIVELY WEAK. SO WL
FCST ONLY CHC POPS OVER MOST OF THE CWA AND MAINLY BTWN 03Z SAT AND
15-18Z SAT...WHEN THE FORCING ACCOMPANYING THE SRN SHRTWV AND A COLD
FNT ATTENDANT TO THE NRN SHRTWV ARE FCST TO EXIT THE ERN CWA AND
GIVE WAY TO SOME VIGOROUS DEEP LYR QVECTOR DVGC. MAINTAINED SOME
LIKELY POPS OVER THE NRN TIER OF THE CWA CLOSE TO THE STRONGER NRN
SHRTWV AND WHERE SHARPER LLVL CNVGC WL ACCOMPANY THE SAT COLD FROPA.
THE COLDEST 00Z GFS/12Z ECMWF RUNS SHOW H85 TEMPS IN THE WAKE OF THE
SAT COLD FROPA PLUNGING AS LO AS -25C BY 00Z SUN...BUT QUICK
TRANSITION TO A MORE DIFFLUENT/ACYC H925 N FLOW AND INVRN BASE
FALLING TO H85-875 WL TEND TO LIMIT LES INTENSITY. RELATIVELY
MODERATE TEMPS INTO SAT MRNG WL FALL THRU THE AFTN AS THE COLDER AIR
SURGES INTO THE AREA IN THE STEADY N FLOW AHEAD OF ARCTIC HI PRES
BLDG SEWD IN SCENTRAL CANADA.
SAT NGT THRU SUN NGT...UPR MI WL REMAIN DOMINATED BY A COLD N
BACKING WNW LLVL FLOW OF ARCTIC AIR ASSOCIATED WITH ARCTIC HI PRES
MOVING FM OVER ALBERTA/SASKATCHEWAN AT 00Z SUN INTO THE UPR MS RIVER
VALLEY BY 12Z MON. EXPECT TEMPS TO RUN WELL BLO NORMAL AND LES TO
CONTINUE NEAR LK SUP WITH H85 TEMPS FCST TO REMAIN NOT FAR FM -22C
TO -25C. SAT NGT COULD BE PARTICULARLY CHILLY OVER THE E WITH THE N
H925 FLOW ALLOWING SOME DRAINAGE OF COLD AIR INTO THAT AREA OFF
ONTARIO. ALTHOUGH FCST ACYC NATURE OF THE H925 FLOW AND NEAR ABSENCE
OF THE DGZ ASSOCIATED WITH THE VERY LO H85 TEMPS WL LIMIT LES
AMOUNTS...SOME OF THE MODELS HINT THERE MAY BE SOME ENHANCED CNVGC
ALONG A LK INDUCED TROF STRETCHING FM THE KEWEENAW TOWARD WHITEFISH
PT THAT WL INTENSIFY AS THE LARGER PRES GRADIENT RELAXES AND A
SHRTWV EMBEDDED IN THE NW FLOW APRCHS ON SUN/SUN NGT. RAISED POPS
WELL ABOVE THE CONSENSUS TO LIKELY ALONG THIS AXIS.
MON...LES ALONG THE LK INDUCED TROF WL BEGIN TO DIMINISH/SHIFT OUT
INTO LK SUP WITH THE APRCH OF A SFC RDG AXIS EXTENDING N FM THE HI
CENTER SHIFTING TOWARD THE OH VALLEY AND THE ASSOCIATED BACKING LLVL
FLOW. BUT THE MORE W WIND COMPONENT WL MEAN LESS LK MODERATION AND
PERSISTENT WELL BLO NORMAL SFC TEMPS EVEN AS THE H85 TEMPS MODERATE
A BIT FASTER.
TUE/WED...THE LONGER RANGE GUIDANCE HINTS ANOTHER CLIPPER TYPE
DISTURBANCE WL PASS THRU THE UPR LKS ON TUE...WITH H85 TEMPS
REBOUNDING TO NEAR -15C IN THE WAA BTWN THIS FEATURE AND HI PRES
MOVING INTO THE MID ATLANTIC. BUT ANOTHER ARCTIC SURGE LOOKS TO
FOLLOW ON WED AS THE SHRTWV PASSAGE REAMPLIFIES THE ERN TROF AND THE
NW FLOW IN ADVANCE OF THE NEXT CNDN HI SINKING INTO THE NRN PLAINS
ADVECTS H85 TEMPS AS LO AS -25 TO -28C INTO THE UPR LKS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1154 PM EST WED JAN 28 2015
DISTURBANCE APPROACHING TONIGHT WILL BRING SOME -SN/DETERIORATING
CONDITIONS. ALL TERMINALS WILL LIKELY FALL TO IFR WITH A FEW HRS OF
LIFR POSSIBLE OVERNIGHT. THERE MAY BE A LITTLE
-FZDZ LATE TONIGHT AT KIWD. PASSAGE OF COLD FRONT
EARLY THU MORNING WILL BRING INCREASING...GUSTY NW
WINDS...ESPECIALLY AT THE MORE EXPOSED KCMX TERMINAL.
OTHERWISE...EXPECT IMPROVEMENT TO MVFR AT ALL TERMINALS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 AM EST THU JAN 29 2015
LOW PRESSURE SYSTEM NEAR N LAKE SUPERIOR THIS MORNING WILL MOVE INTO
QUEBEC THIS AFTERNOON WHILE ANOTHER LOW NEAR CHICAGO SHIFTS EAST
INTO NEW ENGLAND ON FRIDAY MORNING. MEANWHILE...A HIGH OVER S
CENTRAL CANADA WILL MOVE SE INTO MN ON FRIDAY. IN BETWEEN THE
EXITING LOW AND NEARING HIGH...STRONG N-NNW GALES GUSTING 35 TO
AROUND 40KTS WILL DEVELOP THIS AFTERNOON OVER MAINLY CENTRAL AND E
LAKE SUPERIOR. LOOK FOR WINDS TO SLOWLY DIMINISH LATE THIS EVENING
AND OVERNIGHT...WITH GUSTS REMAINING 25-30KTS THROUGH DAYBREAK
FRIDAY. GIVEN THE STRONG WINDS...AND COLDER AIR SURGING IN...HEAVY
FREEZING SPRAY WILL BE POSSIBLE OVER THIS SAME AREA INTO EARLY
FRIDAY MORNING. WINDS WILL THEN QUICKLY DIMINISH AND REMAIN LESS
THAN 30KTS THROUGH FRIDAY NIGHT.
AS THIS HIGH DRIFTS INTO THE OH RIVER VALLEY ON SATURDAY...A TROUGH
WILL SLIDE ACROSS THE UPPER GREAT LAKES. A FEW N TO NW GUSTS OF 30
TO NEAR 35KTS WILL BE POSSIBLE SATURDAY AFTERNOON AND EVENING.
EXPECT HIGH PRESSURE OVER CENTRAL CANADA ON SATURDAY TO MOVE SE INTO
THE N PLAINS ON SUNDAY...AND THE MID MS RIVER VALLEY ON MONDAY.
WINDS SHOULD DIMINISH FOR A TIME SUN BEFORE INCREASING AGAIN MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 7 AM
EST FRIDAY FOR LSZ264-266-267.
GALE WARNING FROM 1 PM THIS AFTERNOON TO 4 AM EST FRIDAY FOR
LSZ267.
GALE WARNING FROM 10 AM THIS MORNING TO 4 AM EST FRIDAY FOR
LSZ265-266.
GALE WARNING UNTIL 1 AM EST FRIDAY FOR LSZ263-264.
HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 1 AM
EST FRIDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KC
AVIATION...07
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
355 AM EST THU JAN 29 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 444 PM EST WED JAN 28 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A PAIR OF SHORTWAVES TO
THE W AND NW. ONE IS MOVING OUT OF WY/CO INTO THE WRN PLAINS AND THE
OTHER IS MOVING FROM SRN SASKATCHEWAN INTO SRN MANITOBA. AHEAD OF
THESE FEATURES...A RIBBON OF STRENGTHENING WAA/ISENTROPIC ASCENT IS
SPREADING ESE ACROSS NRN ONTARIO AND THE UPPER GREAT LAKES
UNDERNEATH RIGHT ENTRANCE OF UPPER JET CURVING FROM NRN ONTARIO DOWN
THRU THE CNTRL APPALACHIANS. REGIONAL RADARS SHOW A STREAK OF RADAR
RETURNS EXTENDING ESE FROM SE MANITOBA ACROSS ADJACENT NRN ONTARIO
AND OVER LAKE SUPERIOR/ERN UPPER MI. THE ASCENT HAS BEEN SUFFICIENT
TO ERODE DRY AIR AT THE LOWER LEVELS AND ALLOW SOME -SN TO REACH THE
GROUND FROM THE TIP OF THE KEWEENAW INTO THE NCNTRL AND ERN FCST
AREA.
PAIR OF SHORTWAVES WILL CONTINUE MOVING ESE TONIGHT WITH THE NRN
STREAM WAVE THE MORE IMPORTANT FEATURE FOR THE WEATHER HERE. AS THE
WAVE APPROACHES...ISENTROPIC ASCENT ON THE 295K SFC INCREASES
TONIGHT...MOST NOTABLY OVER THE E HALF OF UPPER MI. WHILE IT WILL BE
TOO WARM FOR ANY LAKE ENHANCEMENT OFF LAKE MICHIGAN...THE FLOW OFF
THE LAKE WILL STILL AID THE MOISTENING OF THE LOW LEVELS. OVER THE
W...THE WINDOW OF COLUMN MOISTENING IS SHORTER BEFORE THE ISENTROPIC
ASCENT DEPARTS OVERNIGHT. THUS...PCPN AMOUNTS TONIGHT WILL BE
LIGHTEST OVER THE W AND GREATER OVER THE E. 295K SFC SHOWS MIXING
RATIOS OF 3-4G/KG AVBL...SUGGESTING THE POTENTIAL FOR 3-4INCHES OF
SNOW FOR THE ROUGHLY 6HRS OF ASCENT EXPECTED. 4 INCHES IS LIKELY TOO
HIGH SINCE SNOW TO WATER RATIOS SHOULD BE ON THE LOWER SIDE. AS IT
IS...WILL PROBABLY BE CLOSE TO ADVY THRESHOLD OVER THE FAR E...
MAINLY LUCE COUNTY...AS 12HR SNOW ACCUMULATIONS FROM LATE EVENING TO
LATE THU MORNING WILL BE NEAR 3 INCHES. SNOW ACCUMULATIONS WILL BE
STEADILY LIGHTER TO THE W...DOWN TO LESS THAN 1 INCH FAR W AND ALONG
THE WI BORDER. LATE TONIGHT INTO THU MORNING...FCST SOUNDINGS
SUPPORT THE POTENTIAL FOR SOME -FZDZ AS MID LEVEL MOISTURE/SYNOPTIC
SNOW EXIT...LEAVING A LOW LEVEL MOIST LAYER THAT HAS TEMPS HIGHER
THAN -10C. WILL INCLUDE MENTION OF -FZDZ WHERE WINDS WILL BE
UPSLOPING.
COLD FRONT PASSES ACROSS UPPER MI THU MORNING. DESPITE INCREASING
WIND FIELDS...INITIAL CAA IS WEAK AS THERMAL GRADIENT IS DISPLACED
OFF TO THE NW...BUT CAA INCREASES QUICKLY IN THE AFTN. 850MB TEMPS
AROUND -10C IN THE MORNING WILL FALL TO NEAR -20C BY 00Z FRI...AND
THIS WILL RESULT IN FALLING SFC TEMPS...ESPECIALLY IN THE AFTN. LAST
OF THE SYNOPTIC SNOW WILL END OVER THE E IN THE MORNING.
OTHERWISE...THERE MAY NOT BE TOO MUCH IN THE WAY OF PCPN (-SN/-FZDZ)
DURING THE MORNING AWAY FROM AREAS THAT SEE UPSLOPING UNDER NW
WINDS. AS COLDER AIR ARRIVES IN THE AFTN...NW/NNW FLOW LES WILL
INCREASE IN COVERAGE WITH DGZ DROPPING INTO THE CONVECTIVE LAYER.
STRONG SUBSIDENCE/DEEP LAYER QVECTOR DIVERGENCE WILL LIMIT LES
INTENSITY. SO FOR THE MOST PART...EXPECT ACCUMULATIONS MOSTLY AROUND
1 INCH IN THE AFTN. STRONG WINDS WILL DISPLACE LES A LITTLE FARTHER
INLAND THAN NORMAL. SPEAKING OF WINDS...FAVORABLE POSTIONING OF PRES
RISE/FALL COUPLET WILL RESULT IN AN ADDITIVE ISALLOBARIC WIND
COMPONENT. COMBINED WITH 925MB WINDS INCREASING TO AROUND
40KT...CONDITIONS WILL BECOME BLUSTERY ACROSS THE AREA. ALONG THE
LAKE SUPERIOR SHORE AROUND THE TIP OF THE KEWEENAW AND FROM BIG BAY
EASTWARD...WINDS WILL PROBABLY GUST TO 35 TO 45 MPH IN THE AFTN.
DEPENDING ON HOW QUICKLY LES INCREASES IN THE AFTN...BLSN COULD
BECOME A SIGNIFICANT ISSUE NEAR THE LAKE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 327 PM EST WED JAN 28 2015
A SHORTWAVE TROUGH WILL BE OVER THE CWA AT 00Z FRI...WITH MOST OF
THE ASSOCIATED FORCING E OF THE CWA BY THAT TIME. NW-NNW LOW LEVEL
WINDS AND 850MB TEMPS AS LOW AS -22C WILL KEEP SNOW GOING IN THE NW-
NNW WINDS SNOWBELTS THU NIGHT...BUT A SFC RIDGE PUSHING THROUGH ON
FRI WILL LEAD TO A DIMINISHING TREND IN THE LES AS WINDS BECOME ANTI-
CYCLONIC. WINDS TURN SWLY BY FRI NIGHT BEHIND THE TROUGH AND AHEAD
OF A CLIPPER SHORTWAVE/SFC TROUGH THAT WILL MOVE THROUGH LATE FRI
NIGHT/EARLY SAT. NW WIND LES WILL RAMP UP ALONG AND BEHIND THE
TROUGH AS 850MB WINDS AS LOW AS -30C SWEEP ACROSS THE AREA. TEMPS
LOOK TO MODERATE SOME MON INTO TUE AS A RIDGE MOVES THROUGH...WITH
ANOTHER COLD BLAST SHOWN BY MODELS TOWARD THE MIDDLE OF NEXT WEEK.
OVER THE NEXT WEEK THE NW WINDS SNOWBELTS MAINLY E OF MARQUETTE WILL
SEE THE MOST SNOWFALL...WITH PROLONGED LIGHT TO MODERATE SNOWFALL.
WITH THE VERY COLD AIRMASS... GROWTH WILL BE ADVERSELY
IMPACTED...WITH SMALL SNOW FLAKES EFFICIENT AT REDUCING VIS THE
PREDOMINANT CONDITION.
COLD TEMPS ARE A CERTAINTY...ESPECIALLY SUN AND MON WHEN HIGHS WILL
NOT MAKE IT OUT OF THE SINGLE DIGITS ABOVE ZERO IN MOST LOCATIONS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1154 PM EST WED JAN 28 2015
DISTURBANCE APPROACHING TONIGHT WILL BRING SOME -SN/DETERIORATING
CONDITIONS. ALL TERMINALS WILL LIKELY FALL TO IFR WITH A FEW HRS OF
LIFR POSSIBLE OVERNIGHT. THERE MAY BE A LITTLE
-FZDZ LATE TONIGHT AT KIWD. PASSAGE OF COLD FRONT
EARLY THU MORNING WILL BRING INCREASING...GUSTY NW
WINDS...ESPECIALLY AT THE MORE EXPOSED KCMX TERMINAL.
OTHERWISE...EXPECT IMPROVEMENT TO MVFR AT ALL TERMINALS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 AM EST THU JAN 29 2015
LOW PRESSURE SYSTEM NEAR N LAKE SUPERIOR THIS MORNING WILL MOVE INTO
QUEBEC THIS AFTERNOON WHILE ANOTHER LOW NEAR CHICAGO SHIFTS EAST
INTO NEW ENGLAND ON FRIDAY MORNING. MEANWHILE...A HIGH OVER S
CENTRAL CANADA WILL MOVE SE INTO MN ON FRIDAY. IN BETWEEN THE
EXITING LOW AND NEARING HIGH...STRONG N-NNW GALES GUSTING 35 TO
AROUND 40KTS WILL DEVELOP THIS AFTERNOON OVER MAINLY CENTRAL AND E
LAKE SUPERIOR. LOOK FOR WINDS TO SLOWLY DIMINISH LATE THIS EVENING
AND OVERNIGHT...WITH GUSTS REMAINING 25-30KTS THROUGH DAYBREAK
FRIDAY. GIVEN THE STRONG WINDS...AND COLDER AIR SURGING IN...HEAVY
FREEZING SPRAY WILL BE POSSIBLE OVER THIS SAME AREA INTO EARLY
FRIDAY MORNING. WINDS WILL THEN QUICKLY DIMINISH AND REMAIN LESS
THAN 30KTS THROUGH FRIDAY NIGHT.
AS THIS HIGH DRIFTS INTO THE OH RIVER VALLEY ON SATURDAY...A TROUGH
WILL SLIDE ACROSS THE UPPER GREAT LAKES. A FEW N TO NW GUSTS OF 30
TO NEAR 35KTS WILL BE POSSIBLE SATURDAY AFTERNOON AND EVENING.
EXPECT HIGH PRESSURE OVER CENTRAL CANADA ON SATURDAY TO MOVE SE INTO
THE N PLAINS ON SUNDAY...AND THE MID MS RIVER VALLEY ON MONDAY.
WINDS SHOULD DIMINISH FOR A TIME SUN BEFORE INCREASING AGAIN MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 7 AM
EST FRIDAY FOR LSZ264-266-267.
GALE WARNING FROM 1 PM THIS AFTERNOON TO 4 AM EST FRIDAY FOR
LSZ267.
GALE WARNING FROM 10 AM THIS MORNING TO 4 AM EST FRIDAY FOR
LSZ265-266.
GALE WARNING FROM 7 AM THIS MORNING TO 1 AM EST FRIDAY FOR
LSZ263-264.
HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 1 AM
EST FRIDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...07
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1154 PM EST WED JAN 28 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 444 PM EST WED JAN 28 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A PAIR OF SHORTWAVES TO
THE W AND NW. ONE IS MOVING OUT OF WY/CO INTO THE WRN PLAINS AND THE
OTHER IS MOVING FROM SRN SASKATCHEWAN INTO SRN MANITOBA. AHEAD OF
THESE FEATURES...A RIBBON OF STRENGTHENING WAA/ISENTROPIC ASCENT IS
SPREADING ESE ACROSS NRN ONTARIO AND THE UPPER GREAT LAKES
UNDERNEATH RIGHT ENTRANCE OF UPPER JET CURVING FROM NRN ONTARIO DOWN
THRU THE CNTRL APPALACHIANS. REGIONAL RADARS SHOW A STREAK OF RADAR
RETURNS EXTENDING ESE FROM SE MANITOBA ACROSS ADJACENT NRN ONTARIO
AND OVER LAKE SUPERIOR/ERN UPPER MI. THE ASCENT HAS BEEN SUFFICIENT
TO ERODE DRY AIR AT THE LOWER LEVELS AND ALLOW SOME -SN TO REACH THE
GROUND FROM THE TIP OF THE KEWEENAW INTO THE NCNTRL AND ERN FCST
AREA.
PAIR OF SHORTWAVES WILL CONTINUE MOVING ESE TONIGHT WITH THE NRN
STREAM WAVE THE MORE IMPORTANT FEATURE FOR THE WEATHER HERE. AS THE
WAVE APPROACHES...ISENTROPIC ASCENT ON THE 295K SFC INCREASES
TONIGHT...MOST NOTABLY OVER THE E HALF OF UPPER MI. WHILE IT WILL BE
TOO WARM FOR ANY LAKE ENHANCEMENT OFF LAKE MICHIGAN...THE FLOW OFF
THE LAKE WILL STILL AID THE MOISTENING OF THE LOW LEVELS. OVER THE
W...THE WINDOW OF COLUMN MOISTENING IS SHORTER BEFORE THE ISENTROPIC
ASCENT DEPARTS OVERNIGHT. THUS...PCPN AMOUNTS TONIGHT WILL BE
LIGHTEST OVER THE W AND GREATER OVER THE E. 295K SFC SHOWS MIXING
RATIOS OF 3-4G/KG AVBL...SUGGESTING THE POTENTIAL FOR 3-4INCHES OF
SNOW FOR THE ROUGHLY 6HRS OF ASCENT EXPECTED. 4 INCHES IS LIKELY TOO
HIGH SINCE SNOW TO WATER RATIOS SHOULD BE ON THE LOWER SIDE. AS IT
IS...WILL PROBABLY BE CLOSE TO ADVY THRESHOLD OVER THE FAR E...
MAINLY LUCE COUNTY...AS 12HR SNOW ACCUMULATIONS FROM LATE EVENING TO
LATE THU MORNING WILL BE NEAR 3 INCHES. SNOW ACCUMULATIONS WILL BE
STEADILY LIGHTER TO THE W...DOWN TO LESS THAN 1 INCH FAR W AND ALONG
THE WI BORDER. LATE TONIGHT INTO THU MORNING...FCST SOUNDINGS
SUPPORT THE POTENTIAL FOR SOME -FZDZ AS MID LEVEL MOISTURE/SYNOPTIC
SNOW EXIT...LEAVING A LOW LEVEL MOIST LAYER THAT HAS TEMPS HIGHER
THAN -10C. WILL INCLUDE MENTION OF -FZDZ WHERE WINDS WILL BE
UPSLOPING.
COLD FRONT PASSES ACROSS UPPER MI THU MORNING. DESPITE INCREASING
WIND FIELDS...INITIAL CAA IS WEAK AS THERMAL GRADIENT IS DISPLACED
OFF TO THE NW...BUT CAA INCREASES QUICKLY IN THE AFTN. 850MB TEMPS
AROUND -10C IN THE MORNING WILL FALL TO NEAR -20C BY 00Z FRI...AND
THIS WILL RESULT IN FALLING SFC TEMPS...ESPECIALLY IN THE AFTN. LAST
OF THE SYNOPTIC SNOW WILL END OVER THE E IN THE MORNING.
OTHERWISE...THERE MAY NOT BE TOO MUCH IN THE WAY OF PCPN (-SN/-FZDZ)
DURING THE MORNING AWAY FROM AREAS THAT SEE UPSLOPING UNDER NW
WINDS. AS COLDER AIR ARRIVES IN THE AFTN...NW/NNW FLOW LES WILL
INCREASE IN COVERAGE WITH DGZ DROPPING INTO THE CONVECTIVE LAYER.
STRONG SUBSIDENCE/DEEP LAYER QVECTOR DIVERGENCE WILL LIMIT LES
INTENSITY. SO FOR THE MOST PART...EXPECT ACCUMULATIONS MOSTLY AROUND
1 INCH IN THE AFTN. STRONG WINDS WILL DISPLACE LES A LITTLE FARTHER
INLAND THAN NORMAL. SPEAKING OF WINDS...FAVORABLE POSTIONING OF PRES
RISE/FALL COUPLET WILL RESULT IN AN ADDITIVE ISALLOBARIC WIND
COMPONENT. COMBINED WITH 925MB WINDS INCREASING TO AROUND
40KT...CONDITIONS WILL BECOME BLUSTERY ACROSS THE AREA. ALONG THE
LAKE SUPERIOR SHORE AROUND THE TIP OF THE KEWEENAW AND FROM BIG BAY
EASTWARD...WINDS WILL PROBABLY GUST TO 35 TO 45 MPH IN THE AFTN.
DEPENDING ON HOW QUICKLY LES INCREASES IN THE AFTN...BLSN COULD
BECOME A SIGNIFICANT ISSUE NEAR THE LAKE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 327 PM EST WED JAN 28 2015
A SHORTWAVE TROUGH WILL BE OVER THE CWA AT 00Z FRI...WITH MOST OF
THE ASSOCIATED FORCING E OF THE CWA BY THAT TIME. NW-NNW LOW LEVEL
WINDS AND 850MB TEMPS AS LOW AS -22C WILL KEEP SNOW GOING IN THE NW-
NNW WINDS SNOWBELTS THU NIGHT...BUT A SFC RIDGE PUSHING THROUGH ON
FRI WILL LEAD TO A DIMINISHING TREND IN THE LES AS WINDS BECOME ANTI-
CYCLONIC. WINDS TURN SWLY BY FRI NIGHT BEHIND THE TROUGH AND AHEAD
OF A CLIPPER SHORTWAVE/SFC TROUGH THAT WILL MOVE THROUGH LATE FRI
NIGHT/EARLY SAT. NW WIND LES WILL RAMP UP ALONG AND BEHIND THE
TROUGH AS 850MB WINDS AS LOW AS -30C SWEEP ACROSS THE AREA. TEMPS
LOOK TO MODERATE SOME MON INTO TUE AS A RIDGE MOVES THROUGH...WITH
ANOTHER COLD BLAST SHOWN BY MODELS TOWARD THE MIDDLE OF NEXT WEEK.
OVER THE NEXT WEEK THE NW WINDS SNOWBELTS MAINLY E OF MARQUETTE WILL
SEE THE MOST SNOWFALL...WITH PROLONGED LIGHT TO MODERATE SNOWFALL.
WITH THE VERY COLD AIRMASS... GROWTH WILL BE ADVERSELY
IMPACTED...WITH SMALL SNOW FLAKES EFFICIENT AT REDUCING VIS THE
PREDOMINANT CONDITION.
COLD TEMPS ARE A CERTAINTY...ESPECIALLY SUN AND MON WHEN HIGHS WILL
NOT MAKE IT OUT OF THE SINGLE DIGITS ABOVE ZERO IN MOST LOCATIONS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1154 PM EST WED JAN 28 2015
DISTURBANCE APPROACHING TONIGHT WILL BRING SOME -SN/DETERIORATING
CONDITIONS. ALL TERMINALS WILL LIKELY FALL TO IFR WITH A FEW HRS OF
LIFR POSSIBLE OVERNIGHT. THERE MAY BE A LITTLE
-FZDZ LATE TONIGHT AT KIWD. PASSAGE OF COLD FRONT
EARLY THU MORNING WILL BRING INCREASING...GUSTY NW
WINDS...ESPECIALLY AT THE MORE EXPOSED KCMX TERMINAL.
OTHERWISE...EXPECT IMPROVEMENT TO MVFR AT ALL TERMINALS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 444 PM EST WED JAN 28 2015
AHEAD OF AN APPROACHING LOW PRES TROF...S WINDS OF 20-30KT ARE
EXPECTED OVER ERN LAKE SUPERIOR TONIGHT. AS IS TYPICAL FOR SOUTHERLY
WINDS...WINDS WILL BE LIGHTER OVER THE W. THE TROF WILL PASS ACROSS
THE LAKE THU MORNING. BEHIND IT...N TO NW WINDS WILL INCREASE TO 20-
30KT OVER WRN LAKE SUPERIOR. OVER THE CNTRL AND ERN LAKE...WINDS
WILL INCREASE TO GALE FORCE (GUSTS TO AROUND 40KT) FOR THU AFTN AND
NIGHT. COMBINATION OF MUCH COLDER AIR/STRONG WINDS AND BUILDING
WAVES WILL LEAD TO HVY FREEZING SPRAY THU AFTN UNTIL EARLY FRI
MORNING WHEN WINDS/WAVES DIMINISH WITH THE CLOSER APPROACH OF
CANADIAN HIGH PRES. AFTER A PERIOD OF LIGHTER WINDS MOSTLY UNDER
20KT FRI AFTN/NIGHT...WINDS WILL INCREASE AGAIN TO 20-30KT
SAT...ESPECIALLY SAT AFTN/NIGHT...IN THE WAKE OF A LOW PRES TROUGH.
GALES MAY OCCUR OVER PORTIONS OF CNTRL LAKE SUPERIOR. WINDS SHOULD
DIMINISH FOR A TIME SUN BEFORE INCREASING AGAIN MON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 1 PM THURSDAY TO 7 AM EST
FRIDAY FOR LSZ264-266-267.
GALE WARNING FROM 1 PM THURSDAY TO 4 AM EST FRIDAY FOR LSZ267.
GALE WARNING FROM 10 AM THURSDAY TO 4 AM EST FRIDAY FOR LSZ265-
266.
GALE WARNING FROM 7 AM THURSDAY TO 1 AM EST FRIDAY FOR LSZ263-
264.
HEAVY FREEZING SPRAY WARNING FROM 1 PM THURSDAY TO 1 AM EST
FRIDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...07
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
349 AM CST THU JAN 29 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM CST THU JAN 29 2015
SHORT TERM CONCERNS ARE HEADLINES EARLY THIS MORNING. THEN OVERALL
IMPROVING TREND AND TURNING COLDER.
RADAR CONTINUES TO SHOW SOME LIGHT INTENSITY ECHOES MOVING ACROSS
EAST CENTRAL MN. WATER VAPOR IMAGERY SHOWING SECONDARY TROUGH
MOVING INTO WESTERN MN NOW. THE TREND ON THE RAP HAS BEEN
GENERATING SOME LIGHT QPF INTO SOUTH CENTRAL MN THROUGH ABOUT 14Z.
NOTHING TOO DRAMATIC ON RADAR...ALTHOUGH SURFACE OBS CONTINUE TO
SHOW SOME VISIBILITY REDUCTION IN BR AND OCCASIONALLY SOME -SN OR UP.
WILL CONTINUE THE FREEZING RAIN ADVISORY THROUGH 12Z. WILL WORD
THAT PRECIPITATION SHOULD BE ENDING THIS MORNING.
THE OTHER CONCERN IS THE WIND ADV TO THE SOUTHWEST. WINDS HAVE BEEN
INCREASING TO THE WEST OVERNIGHT AS THE PRESSURE GRADIENT INCREASES
WITH THE COLD FRONT MOVING THROUGH. THIS SHOULD CONTINUE THROUGH AT
LEAST MID MORNING AS THE GREATEST PRESSURE RISE MOVES THROUGH THE
AREA. HAVE INCLUDED A COUPLE MORE COUNTIES IN WEST CENTRAL MN AS
WELL.
WINDS ARE EXPECTED TO DIMINISH OVERALL AFTER 18Z AND BECOME LIGHT
INTO TONIGHT. CLOUDS WILL THIS AS WELL WITH TEMPERATURES DROPPING
THROUGH THE SINGLE DIGITS AND TEENS FOR LOWS TONIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 349 AM CST THU JAN 29 2015
WEST/NORTHWEST FLOW WILL PREVAIL THROUGH THE MAJORITY OF THE LONG
TERM FORECAST PERIOD...WITH ONLY MINOR/FLEETING CHANCES FOR
PRECIPITATION FORESEEN INTO EARLY NEXT WEEK.
FRIDAY WILL BE A TALE OF TWO STORIES WITHIN THE FORECAST AREA...AS
THE DEPARTING SURFACE HIGH YIELDS TEMPS AROUND 5 TO 10 DEGREES
BELOW NORMAL IN THE EAST OVER WISCONSIN...AND LOW LEVEL WARM AIR
ADVECTION OVER THE WEST BRINGS HIGHS FROM 5 TO 10 DEGREES ABOVE
NORMAL TO WEST CENTRAL AND SOUTHWESTERN MINNESOTA. EXPECT HIGH
TEMPS TO RANGE FROM 15 TO 20 DEGREES OVER WEST CENTRAL WI...TO THE
LOWER 30S ALONG THE MN RIVER VALLEY.
ON SATURDAY...THE GFS AND ECMWF MODELS ARE STICKING TO THEIR GUNS
IN PROGGING THE BULK OF THE PRECIPITATION TO PASS SOUTH OF THE
FORECAST AREA...AS AN INCOMING ARCTIC HIGH SUPPRESSES THE SYSTEM
LIFTING OUT OF THE SOUTHWESTERN CONUS. COULD SEE A LIGHT ROUND OF
SNOWFALL WITH INCH OR SO ACCUMULATIONS ON SATURDAY NIGHT AHEAD OF
THE APPROACHING HIGH...BUT THE MAIN /SOUTHERN STREAM/ SYSTEM
SHOULD STAY WELL SOUTH OF THE AREA.
THE ARCTIC HIGH WILL INEVITABLY BE ACCOMPANIED BY A NOTABLE
REDUCTION IN TEMPERATURES...WITH HIGHS FROM 5 TO 15 DEGREES ON
SUNDAY...AND SUB-ZERO LOWS OCCURRING NEARLY AREA-WIDE ON SUNDAY
NIGHT. ASSOCIATED WINDS WILL BE RATHER LIGHT...SO DO NOT CURRENTLY
EXPECT WIND CHILLS TO DIP LOWER THAN -15 TO -20 ON SUNDAY NIGHT
AND MONDAY MORNING.
AS THE HIGH SLIPS OFF TO THE SOUTHEAST...TEMPERATURES WILL
GRADUALLY MODERATE BACK TO NORMAL AS A SURFACE TROUGH APPROACHES
FROM THE NORTHERN ROCKIES. THIS FEATURE MAY BRING A LIGHT ROUND OF
SNOW ON MONDAY NIGHT INTO TUESDAY MORNING...DURING WHICH 20-30
POPS HAVE BEEN INCLUDED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1127 PM CST WED JAN 28 2015
LARGE AREA OF -FZDZ SLOWLY ERODING AWAY TO THE E AS CDFNT MAKES
PROGRESS THRU THE CWFA. THIS IS ALLOWING WRN MN TO HAVE CEILINGS
RISE FROM IFR RANGE TO MVFR RANGE WHILE VSBY INCRS TO VFR. THIS
TREND WILL CONTINUE EWD SLOWLY THRU THE EARLY MRNG HRS. IN
CONJUNCTION WITH THE CLEARING WILL BE A STRONG SURGE IN WIND
SPEEDS IN THE WAKE OF THE CDFNT. NW WINDS WILL INCREASE TO 15-25
KT WITH HIGHER GUSTS DURG THE EARLY MRNG HRS...LASTING THRU THU
AFTN BEFORE SPEEDS DISSIPATE THU EVE. THE INCRS IN WIND SPEEDS
WILL HELP SCOUR OUT NEAR-SFC MOISTURE...ALLOWING VSBYS TO QUICKLY
INCRS BUT THE LOW STRATUS WILL LINGER FOR MUCH OF THE DAY. BY LATE
AFTN...ANY LINGERING LOW STRATUS WILL SCATTER OUT...RESULTING IN
VFR CONDS BY LATE THU AFTN INTO THU EVE.
KMSP...HAVE INITIALIZED WITH IFR CONDS BUT AS THE CDFNT CONTINUES
TO SHIFT E ACRS THE AREA...VSBY WILL QUICKLY IMPROVE BETWEEN 06Z-
08Z TO VFR CONDS. CIGS WILL BE SLOW TO FOLLOW BY AM EXPECTING CIGS
TO RISE INTO MVFR RANGE BY 08Z. STILL SOME QUESTION AS TO HOW
QUICKLY CIGS RISE ABOUT THE 1700 FT THRESHOLD...AND IF ANYTHING...
THE TIMING MAY BE LATER THAN THE 14Z TIMEFRAME CURRENTLY
ADVERTISED. OTHERWISE...CONDS ARE ON TRACK TO REACH VFR LEVELS BY
LATE THU AFTN WITH CONTINUED IMPROVEMENT THRU THU NIGHT.
/OUTLOOK FOR KMSP/
FRI...VFR. WIND S 5 KT.
SAT...MAINLY VFR...CHC MVFR CIGS/-SN. WIND N 5-10 KT.
SUN...MAINLY VFR...CHC MVFR CIGS. WIND N 10 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FREEZING RAIN ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR
MNZ051>053-059>063-066>070-075>078-083>085.
WIND ADVISORY UNTIL 9 AM CST THIS MORNING FOR MNZ047-048-054>057-
064-065-073>075-082>084-091>093.
WI...FREEZING RAIN ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR
WIZ014>016-023>028.
&&
$$
SHORT TERM...DWE
LONG TERM...LS
AVIATION...JPC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1134 PM CST WED JAN 28 2015
.UPDATE...
ISSUED AT 1127 PM CST WED JAN 28 2015
UPDATED TO INCLUDE 06Z AVIATION DISCUSSION BELOW.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 342 PM CST WED JAN 28 2015
AN ACTIVE SHORT TERM AHEAD AS A LOW PRESSURE SYSTEM OVER THE
EASTERN DAKOTAS SLIDES SOUTHEAST INTO NORTHERN IL BY THURSDAY
MORNING. LITTLE ICE IS INDICATED ALOFT OVER NORTHERN AND EASTERN
AREAS OF THE FA TONIGHT WITH DEEPENING LOW LEVEL SATURATION. IN
ADDITION...SOUTHERLY LOW LEVEL WINDS INCREASE RATHER DRAMATICALLY
EARLY TONIGHT ACROSS EASTERN IA ON NORTHWARD INTO WEST CENTRAL
WI...WITH A VEERING PROFILE THROUGH 800MB. THIS SHOULD ADD THE
TURBULENCE FACTOR TO ALLOW FREEZING DRIZZLE TO BECOME WIDESPREAD
ACROSS MUCH OF WEST CENTRAL WI FROM AROUND MID EVENING INTO EARLY
THURSDAY MORNING. THIS IS COLLABORATED BY RUNS TODAY OF THE
HOPWRF...HRRR AND RAP SHOWING SOME A FEW HUNDREDTHS OF QPF IN THE
AFOREMENTIONED AREAS. THEREFORE...ISSUED A FREEZING RAIN ADVISORY
FROM 9 PM THROUGH 3 AM FROM RICE LAKE AND LADYSMITH ON SOUTH
THROUGH MENOMONIE AND AUGUSTA. THE EVENING SHIFT WILL NEED TO KEEP
A CLOSE EYE FROM THE TWIN CITIES ON NORTHWARD WHERE CONFIDENCE ON
THE FREEZING DRIZZLE IS LOWER.
IN THE WAKE OF THE LOW PRESSURE SYSTEM...THE SURFACE PRESSURE
GRADIENT INCREASES SIGNIFICANTLY ACROSS EASTERN SD AND SW MN
AFTER MIDNIGHT (12 MILLIBARS). IN FACT...6 HOUR PRESSURE CHANGES
ARE NEAR 14 MILLIBARS TO OUR WEST. BUFKIT PROFILE DATA SHOWED TWO
THINGS. FIRST...THE NAM PROFILE HAD THE STRONGEST TOP OF THE
CHANNEL WINDS NEARING 50 KNOTS ACROSS THE MN RIVER VALLEY AROUND
09Z WHILE THE GFS PROFILE HAD 32 KNOT WINDS AT 200 FEET AT KFRM.
THE COMBINATION OF CAA AND A UNIDIRECTIONAL FLOW TO THE TOP OF THE
CHANNEL RESULTED IN A WIND ADVISORY BEING ISSUED ALONG AND SOUTH
OF A LINE FROM APPLETON TO ALBERT LEA FROM MIDNIGHT THROUGH 9 AM.
TEMPERATURES TONIGHT AND THURSDAY ARE INTERESTING. BECAUSE OF THE
LOW PRESSURE SYSTEM COMING INTO THE AREA TONIGHT...TEMPERATURES
WILL WARM A LITTLE THIS EVENING AND THEN DROP BACK TO A LITTLE
BELOW WHERE WE ARE NOW. THURSDAY`S HIGHS WILL BE EARLY IN THE
MORNING WITH READINGS FALLING INTO THE TEENS AND LOWER 20S BY
THIS TIME THURSDAY AFTERNOON.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 342 PM CST WED JAN 28 2015
BY TOMORROW EVENING...THE PRESSURE GRADIENT WILL BE WEAKENING AND
THOSE STRONG NORTHWESTERLY WINDS WILL START TO SLOWLY DECREASE. A
SURFACE HIGH WILL DRIFT SOUTHEAST THROUGH OUR AREA OVERNIGHT
THROUGH FRIDAY MORNING...WHICH WILL BE ONE OF THE COOLER
MORNINGS WE`VE HAD IN TWO+ WEEKS WITH LOWS RANGING FROM NEAR ZERO
NEAR LADYSMITH...TO ABOUT 10-15 ABOVE TOWARD REDWOOD FALLS. THE
CORE OF THE COLD WILL ESSENTIALLY MISS US TO THE EAST AS IT IS
DRAGGED SOUTH BEHIND THE SYSTEM IMPACTING OUT REGION TONIGHT.
ON FRIDAY...MODEST WARM AIR ADVECTION WILL ENSUE AND ALLOW
TEMPERATURES TO WARM TO VERY NEAR SEASONAL NORMALS. WITH THE COLDER
AIR IN PLACE TO THE EAST OF THE AREA...HIGHS WILL STRUGGLE TO REACH
20 IN WEST CENTRAL WI...BUT WARMER AIR THE FURTHER WEST YOU GO WILL
YIELD HIGHS IN THE MID 20S FOR EASTERN MN AND LOW 30S ACROSS FAR
SOUTHWESTERN MN.
THE MAIN CHANGE FROM THE PREVIOUS FORECAST WAS TO THE SATURDAY
NIGHT SYSTEM. BOTH THE GFS AND EC RUNS CAME IN WITH A STRONG
SURFACE HIGH PUSHING SOUTH FROM SASKATCHEWAN INTO THE UPPER
MIDWEST AS THE NORTHERN STREAM JET BUCKLES SOUTHWARD ALLOWING DRY
ARCTIC AIR TO ADVANCE FURTHER SOUTH THAN PREVIOUS RUNS INDICATED.
THIS IS A GREAT HINDRANCE TO THE POTENTIAL FOR SNOW FROM A SYSTEM
DEVELOPING IN THE SOUTHWESTERN CONUS. BUT...THERE IS POTENTIAL FOR
LIGHT SNOW FROM A NORTHERN STREAM SHORTWAVE SATURDAY NIGHT. THIS
LINES UP WELL WITH AN ENHANCED AREA OF PV ADVECTING SOUTHEAST AND
IN CONJUNCTION WITH THE LEFT EXIT REGION OF A 120KT JET STREAK.
ANY SNOW THAT DOES FALL THROUGH WILL BE VERY LIGHT WITH THE PRE-
EXISTING LOW LEVEL DRY AIR.
IT LOOKS LIKE WE`LL BEGIN FEBRUARY WITH TEMPERATURES SLIGHTLY BELOW
NORMAL AFTER AN IMPRESSIVE WARM STRETCH FOR THE LAST 3 WEEKS OF
JANUARY. BOUTS OF ARCTIC AIR WILL DROP SOUTH THROUGH THE
NORTHERN/NORTHEASTERN GREAT LAKES...GIVING US MORE OF A GLANCING
BLOW. ANOTHER POSSIBLE CLIPPER SYSTEM COULD BRING ANOTHER SHOT OF
VERY LIGHT SNOW MONDAY NIGHT/TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1127 PM CST WED JAN 28 2015
LARGE AREA OF -FZDZ SLOWLY ERODING AWAY TO THE E AS CDFNT MAKES
PROGRESS THRU THE CWFA. THIS IS ALLOWING WRN MN TO HAVE CEILINGS
RISE FROM IFR RANGE TO MVFR RANGE WHILE VSBY INCRS TO VFR. THIS
TREND WILL CONTINUE EWD SLOWLY THRU THE EARLY MRNG HRS. IN
CONJUNCTION WITH THE CLEARING WILL BE A STRONG SURGE IN WIND
SPEEDS IN THE WAKE OF THE CDFNT. NW WINDS WILL INCREASE TO 15-25
KT WITH HIGHER GUSTS DURG THE EARLY MRNG HRS...LASTING THRU THU
AFTN BEFORE SPEEDS DISSIPATE THU EVE. THE INCRS IN WIND SPEEDS
WILL HELP SCOUR OUT NEAR-SFC MOISTURE...ALLOWING VSBYS TO QUICKLY
INCRS BUT THE LOW STRATUS WILL LINGER FOR MUCH OF THE DAY. BY LATE
AFTN...ANY LINGERING LOW STRATUS WILL SCATTER OUT...RESULTING IN
VFR CONDS BY LATE THU AFTN INTO THU EVE.
KMSP...HAVE INITIALIZED WITH IFR CONDS BUT AS THE CDFNT CONTINUES
TO SHIFT E ACRS THE AREA...VSBY WILL QUICKLY IMPROVE BETWEEN 06Z-
08Z TO VFR CONDS. CIGS WILL BE SLOW TO FOLLOW BY AM EXPECTING CIGS
TO RISE INTO MVFR RANGE BY 08Z. STILL SOME QUESTION AS TO HOW
QUICKLY CIGS RISE ABOUT THE 1700 FT THRESHOLD...AND IF ANYTHING...
THE TIMING MAY BE LATER THAN THE 14Z TIMEFRAME CURRENTLY
ADVERTISED. OTHERWISE...CONDS ARE ON TRACK TO REACH VFR LEVELS BY
LATE THU AFTN WITH CONTINUED IMPROVEMENT THRU THU NIGHT.
/OUTLOOK FOR KMSP/
FRI...VFR. WIND S 5 KT.
SAT...MAINLY VFR...CHC MVFR CIGS/-SN. WIND N 5-10 KT.
SUN...MAINLY VFR...CHC MVFR CIGS. WIND N 10 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FREEZING RAIN ADVISORY UNTIL 6 AM CST THURSDAY FOR MNZ041>045-
047>053-055>063-065>070-075>078-083>085.
WIND ADVISORY UNTIL 9 AM CST THURSDAY FOR MNZ054-056-064-065-
073>075-082>084-091>093.
WI...FREEZING RAIN ADVISORY UNTIL 6 AM CST THURSDAY FOR WIZ014>016-
023>028.
&&
$$
UPDATE...JPC
SHORT TERM...RAH
LONG TERM...SPD
AVIATION...JPC
AREA FORECAST DISCUSSION
NWS BILLINGS MT
929 PM MST WED JAN 28 2015
.UPDATE...
WEAK SHORTWAVE CONTINUES TO PRODUCE A FEW ECHOES IN OUR CENTRAL
PARTS...AND WILL SUSTAIN FLURRIES/SPRINKLES THROUGH MIDNIGHT...
WITH DESCENT SPREADING IN THEREAFTER ENDING ANY PCPN CHANCES.
THERE WAS A BRIEF PERIOD OF UPSLOPE ENHANCEMENT ALONG THE SE EDGE
OF THE BEARTOOTH FOOTHILLS EARLIER THIS EVENING...AND IN FACT WE
RECEIVED A SPOTTER REPORT OF ABOUT AN INCH OF SNOW IN RED LODGE.
PCPN IS MUCH LIGHTER NOW. AREA OF STRATUS CONTINUES TO CLIP OUR
FAR EAST NEAR BAKER AND EKALAKA. SOUNDINGS MAY BE A BIT OVERDONE
WITH THE LOW LEVEL MOISTURE BASED ON LOCAL METARS...BUT GIVEN THE
BOUNDARY LAYER MOISTURE AND INSTABILITY WITH TEMPS NO COLDER THAN
-8C...FEEL SOME LIGHT FREEZING DRIZZLE IS STILL A POSSIBILITY
MAINLY OVER THE HILLS OF FALLON AND NORTHERN CARTER COUNTIES WHERE
THE TERRAIN WILL BE CLOSER TO THE CLOUD BASES. ONLY OTHER ISSUE IS
FOG POTENTIAL. DEW PT DEPRESSIONS AT JDN AND MLS ALREADY DOWN TO
2-3F...WITH CLEAR SKIES AND DECREASING WINDS EXPECTED THRU THE
NIGHT. HRRR IS PINGING NORTHERN ROSEBUD WITH FOG TONIGHT...AND
THIS AREA JUST WEST OF THE CURRENTLY OBSERVED WNW WINDS MAKES
SENSE. COULD SEE SOME VALLEY FOG DEVELOP NEAR OR MAYBE JUST EAST
OF BILLINGS TOO... WITH STRONGER DRAINAGE EXPECTED TO HOLD OFF TIL
AROUND 15Z TOMORROW. HAVE EXPANDED COVERAGE OF PATCHY FOG WESTWARD
TO INCLUDE THESE AREAS. JKL
&&
.SHORT TERM...VALID FOR THU AND FRI...
SHORT WAVE THAT BROUGHT SOME SNOW TO THE HIGH COUNTRY LAST NIGHT
HAS EXCITED THE REGION...BUT COLD AIR IS BEING PULLED DOWN FROM
THE NORTH BEHIND IT. ASSOCIATED STRATUS ON VISIBLE SATELLITE
IMAGERY WAS MOVING INTO OUR NORTHERN ZONES AT MIDDAY AND IS
EXPECTED TO SPREAD ACROSS MUCH OF OUR CENTRAL/EASTERN ZONES BY
EVENING. CROSS SECTIONS INDICATE THE STRATUS WILL LINGER THROUGH
THE NIGHT BEFORE GRADUALLY DISSIPATING EARLY THURSDAY FROM WEST TO
EAST. THERE WILL BE A TYPICAL TRADE-OFF BETWEEN CAA AND LINGERING
STRATUS TONIGHT TO MAKE OVERNIGHT LOWS TRICKY IN OUR EAST...BUT
FEEL CAA WILL GENERALLY WIN OUT AND HAVE STUCK CLOSE TO INHERITED
FORECASTS/GUIDANCE. THERE WILL CERTAINLY BE A COOLER AIR MASS IN
PLACE OVER US TOMORROW...BUT NOTHING DRASTIC AND WE SHOULD BRIEFLY
SEE SOME SUNSHINE AROUND MIDDAY KEEPING US ON THE MILD SIDE
COMPARED TO SEASONAL AVERAGES.
THE OVERALL FLOW PATTERN IS STILL ANTICYCLONIC THURSDAY WITH SOME
WEAK QUASI LOW PRESSURE LINGERING OVER THE GREAT BASIN.
HOWEVER...WE BEGIN TO TRANSITION TO A BRISK NW FLOW ALOFT WITH
SHORT WAVE ENERGY OUT OF CANADA TRACKING THROUGH NE MONTANA BY
LATE FRIDAY NIGHT. THIS MAY OPEN THE DOOR TO UNSETTLED AND MUCH
COOLER WEATHER FOR THE WEEKEND. PLEASE SEE THE LONG TERM
DISCUSSION BELOW FOR MORE DETAILS. BT
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
A CHANGE IN THE PATTERN TO COLDER WEATHER WITH PERIODS OF SNOW
APPEARS LIKELY FOR THE EXTENDED PERIOD BEGINNING ON SAT. WHILE
MODELS AGREED WITH THIS OVERALL SCENARIO...THE PATTERN DETAILS
DIFFERED BETWEEN THEM.
JET ENERGY WILL DIVE SE INTO THE AREA ON SAT ACCOMPANIED BY A
SHORTWAVE AND BACKDOOR COLD FRONT. GFS WAS THE MOST AGGRESSIVE
MODEL IN BRINGING QPF SW INTO THE AREA COMPARED TO THE OTHER
MODELS. THE CANADIAN AND ECMWF BRING THE QPF IN ON SAT NIGHT.
BASED ON THE TIMING UNCERTAINTY...SLOWED DOWN ARRIVAL OF HIGHER
POPS IN THE SW PART OF THE AREA ON SAT...AND WENT WITH MAINLY
CHANCE POPS SAT NIGHT.
FLOW THEN TRANSITIONS INTO A FLAT NW FLOW ON THE MODELS FOR SUN
INTO TUE. MODELS HAD PACIFIC MOISTURE OVERRUNNING THE SURFACE
BOUNDARY ON SUN BUT DIFFERED IN THEIR QPF DEPICTIONS. WEAK
SHORTWAVE ENERGY REINFORCES THE COLD AIR OVER THE REGION ON MON
AND TUE WHILE PACIFIC MOISTURE CONTINUES TO OVERRUN THE BOUNDARY.
BLENDED POPS FOR THIS TIME FRAME WITH THE SUPERBLEND GUIDANCE AS
THE MODELS DIFFERED IN PRECIPITATION DETAILS. INHERITED TUE POPS
LOOKED REASONABLE.
ENERGY THEN WRAPS AROUND THE HUDSON BAY LOW FOR THE END
OF THE PERIOD. THIS ENERGY WILL REINFORCE THE COLD AIRMASS OVER
THE AREA. WILL CONTINUE TO USE A MODEL BLEND FOR POPS.
TEMPERATURE PROFILES ALSO DIFFERED BETWEEN THE MODELS FOR MUCH OF
THE PERIOD SO WENT WITH SUPERBLEND. RESULT WAS PERIODS OF
SEASONAL AND BELOW NORMAL TEMPERATURES. ARTHUR
&&
.AVIATION...
LOW CLOUDS AND PATCHY FOG WILL RESULT IN MVFR/IFR CONDITIONS EAST
OF KBIL THROUGH EARLY THURSDAY MORNING. SOME FREEZING DRIZZLE IS
ALSO POSSIBLE AROUND KBHK. AREA MOUNTAINS WILL BE OBSCURED AT
TIMES. ELSEWHERE...VFR CONDITIONS WILL PREVAIL UNDER PARTLY CLOUDY
SKIES. HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
THU FRI SAT SUN MON TUE WED
-----------------------------------------------------------
BIL 028/048 030/050 028/038 019/030 022/041 027/039 019/032
10/U 00/U 03/W 33/J 33/W 32/W 23/J
LVM 028/048 027/048 024/040 020/036 025/045 029/043 024/038
00/U 00/U 03/W 23/J 43/W 32/W 23/W
HDN 022/046 025/048 023/035 015/029 017/038 021/035 015/030
10/U 00/U 03/W 32/J 33/J 33/J 23/J
MLS 025/044 027/044 024/032 011/023 014/032 017/028 011/025
10/U 00/U 04/J 22/J 22/J 23/J 22/J
4BQ 025/048 027/049 025/037 015/029 018/039 021/035 016/030
00/U 00/U 03/W 32/J 22/W 23/J 22/J
BHK 025/040 024/043 021/028 007/020 009/029 015/027 009/023
10/B 00/U 04/J 32/J 22/J 23/J 22/J
SHR 022/044 020/045 020/037 015/029 016/040 020/038 017/032
10/U 00/U 03/W 32/J 22/W 32/J 23/J
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
400 AM CST THU JAN 29 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 359 AM CST THU JAN 29 2015
SFC OBS INDICATE CEILINGS ARE RISING ACROSS
NCNTL NEB. THE CLOUDS ARE ASSOCIATED WITH COLD AIR ADVECTION WHICH
THE NAM AND RAP MODELS SHOW WEAKENING THIS MORNING 15Z-18Z. THUS WE
SHOULD SEE A CONTINUED EROSION OF THE CLOUD COVER WITH MOSTLY SUNNY
SKIES FROM 18Z ONWARD.
THE MODEL CONSENSUS SUGGESTS HIGHS IN THE 40S TODAY. THE TEMPERATURE
FORECAST IS CLOSE TO RAP MODEL WHICH GENERALLY WORKS WELL IN CLEAR
SKY CONDITIONS.
TONIGHT...HIGH PRESSURE WILL MOVE OFF SLOWLY EAST WITH SOUTH WINDS
DEVELOPING ACROSS THE PANHANDLE FROM 03Z ONWARD AND SPREADING SLOWLY
EAST OVERNIGHT. THE COLDEST READINGS SHOULD OCCUR ALONG AND EAST OF
HIGHWAY 83 WHERE WINDS WILL REMAIN LIGHT AND VARIABLE MOST OF THE
NIGHT.
WINDS TODAY SHOULD CONTINUE TO DECREASE FROM WEST TO EAST. THE RAP
MODEL INDICATES NORTH WINDS AT JUST 10 TO 15 MPH BY 3 PM THIS AFTN
AS PACIFIC HIGH PRESSURE BUILDS INTO WRN NEB.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 359 AM CST THU JAN 29 2015
A WEAKENING UPPER LEVEL RIDGE WILL TRANSLATE EAST ACROSS THE CENTRAL
PORTIONS OF THE UNITED STATES FRIDAY. MILD PACIFIC AIR WILL
ACCOMPANY THE RIDGING...WITH H850MB TEMPERATURES RANGING FROM
2C TO 4C ACROSS THE AREA. THE DAY WILL START SUNNY...BUT SOME
INCREASE IN HIGH CLOUDINESS EXPECTED BY LATER IN THE DAY AS SUB
TROPICAL MOISTURE BEGINS TO APPROACH THE AREA FROM THE SOUTHWEST.
WITH THE MILD AIR IN PLACE AND EXPECTED SUN...WILL RAISE HIGHS A FEW
DEGREES INTO THE MID 40S TO LOWER 50S.
STILL LOOKS INTERESTING FRIDAY NIGHT THROUGH SATURDAY NIGHT. A
LARGE PLUMB OF SUB TROPICAL MOISTURE...ORIGINATING OFF THE WEST
COAST OF MEXICO...WILL BE DRAWN NORTHWARD INTO THE SOUTHERN AND
POSSIBLY CENTRAL PLAINS AHEAD OF AN UPPER LEVEL TROUGH THAT WILL
MOVE INTO THE DESERT SOUTHWEST/WESTERN CONUS BY FRIDAY EVENING. AT
THE SAME TIME...A NORTHERN STREAM SHORTWAVE WILL BE MOVING INTO
BRITISH COLUMBIA FROM THE GULF OF ALASKA. MODELS HAVE BEEN
STRUGGLING WITH THE NORTHERN STREAM FEATURE...WITH SOME MODEL RUNS
STRONGER AND MORE AMPLIFIED WITH THE SHORTWAVE...AND OTHERS WEAKER
AND MORE SHEARED. THE LATEST 29/00Z RUN OF THE ECMWF SUPPORTS A
WEAKER...FASTER AND MORE SHEARED SHORTWAVE...WITH THE GFS A BIT
SLOWER AND MORE AMPLIFIED...AND THE NAM BEING THE MOST AMPLIFIED AND
SLOWEST OF ALL. HOW THE NORTHERN STREAM SYSTEM INTERACTS WITH THE
SUB TROPICAL MOISTURE REMAINS IN QUESTION. A SLOWER MORE AMPLIFIED
SCENARIO WOULD PULL MOISTURE FARTHER NORTH THOUGH THE FORECAST
AREA...WHILE A FASTER MORE SHEARED SCENARIO WOULD TEND TO SHUNT MUCH
OF THE SUB TROPICAL MOISTURE OFF TO THE EAST. THE SLOWER MORE
AMPLIFIED NAM WOULD FAVOR BETTER CHANCES FOR SNOW...WHILE THE GFS
AND ESPECIALLY THE ECMWF WOULD NOT. DUE TO THE WOBBLING OF THE
MODELS IN REGARDS TO THE NORTHERN STREAM...WILL ONLY MAKE SLIGHT
ADJUSTMENTS TO THE CURRENT POP FORECAST. WILL MAINTAIN THE LOW
CHANCE POPS ACROSS CENTRAL AND PORTIONS OF NORTH CENTRAL
NEBRASKA...WITH A DECREASE TO JUST SLIGHT CHANCES FARTHER WEST.
NORTHERN STREAM ENERGY IS QUITE DIFFICULT TO FORECAST...AND EXPECT
THAT MODELS WILL CONTINUE TO WOBBLE SOME UNTIL THE FEATURE IS
ONSHORE FRIDAY.
AS THE NORTHERN STREAM ENERGY PASSES...EXPECT A BATCH OF ARCTIC AIR
TO PUSH SOUTH INTO THE CENTRAL AND NORTHERN PLAINS IN IT/S WAKE
SUNDAY. UPPER FLOW QUICKLY BECOMES MORE ZONAL MONDAY...WITH PACIFIC
AIR SPREADING BACK INTO THE REGION FROM THE WEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1121 PM CST WED JAN 28 2015
WINDY CONDITIONS WILL PERSIST PRIOR TO 12Z...THEN DIMINISH
THURSDAY MORNING. MVFR STRATUS WILL BE OBSERVED ACROSS THE AREA
OVERNIGHT...WHICH LOOKS TO MIX OUT MID TO LATE THURSDAY MORNING AT
THE KLBF AND KVTN TERMINALS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...ROBERG
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
316 AM CST THU JAN 29 2015
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 312 AM CST THU JAN 29 2015
EXTENSIVE LOW CLOUD LAYER HAD OVERSPREAD EASTERN NEBRASKA AND
SOUTHWEST IOWA EARLY THIS MORNING. HRRR SUGGESTS CLOUDS WILL
LIKELY HANG TOUGH THROUGH THE MORNING BEFORE BREAKING UP FROM WEST
TO EAST DURING THE EARLY AFTERNOON. GUSTY NORTHWEST WINDS ALSO
EXPECTED TO CONTINUE INTO THE MORNING ALTHOUGH LATEST TREND
APPEARS TO BE A DECREASE FROM NORTH TO SOUTH THROUGH 12Z. WILL
ADD REMAINING SOUTHERN COUNTIES TO ADVISORY THROUGH EXPIRATION AT
7 AM. HIGH PRESSURE RIDGE THEN SETTLES OVER THE AREA TONIGHT
BEFORE MOVING EAST ON FRIDAY.
NEXT FORECAST CONCERN DEVELOPS FRIDAY NIGHT AND SATURDAY AS A COLD
FRONT MOVES INTO THE AREA FROM THE NORTH WHILE LOW LEVEL WARM
ADVECTION MOVES IN FROM THE SOUTH IN ADVANCE OF CLOSED UPPER LOW
OVER THE SOUTHWEST PART OF THE COUNTRY. LATEST MODEL SOLUTIONS
INDICATE AN AREA OF LIGHT PRECIP SPREADING INTO THE SOUTH HALF OF
THE FORECAST AREA BY SATURDAY MORNING THEN LINGERS THROUGH
SATURDAY NIGHT.
AT THIS TIME IT APPEARS NORTHERN PARTS OF THE AREA SHOULD STAY DRY
FOR THE MOST PART. DRIER AIR COMING IN WITH NEXT BATCH OF COLD AIR
LOOKS TO LIMIT NORTHERN EXTENT OF PRECIP WITH A SHARP CUTOFF
ACROSS EAST CENTRAL NEBRASKA AND WEST CENTRAL IOWA. PRECIP LIKELY
TO START OFF AS LIQUID ALONG THE SOUTHEAST BORDER AREA LATE FRIDAY
NIGHT THEN TRANSITION TO LIGHT SNOW DURING THE DAY SATURDAY AS THE
COLD AIR DEEPENS BEHIND THE FRONT. SOME LIGHT SNOW ACCUMULATION IN
THE 1 TO 2 INCH RANGE POSSIBLE BY SUNDAY MORNING ACROSS SOUTHEAST
NEBRASKA INTO SOUTHWEST IOWA WITH UPPER BOUND NEAR SOUTHERN BORDER
OF NEBRASKA AND SOUTHWEST IOWA.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 312 AM CST THU JAN 29 2015
MUCH COLDER AIR MOVES IN ON SUNDAY AS THE SOUTHERN PLAINS WEATHER
SYSTEM MOVES EAST AND HIGH PRESSURE BUILDS INTO THE CENTRAL
PLAINS. COLDEST AIR HANGS AROUND THROUGH MONDAY BEFORE SOME
MODERATION RETURNS AS ANOTHER CLIPPER MOVES INTO THE REGION MONDAY
NIGHT. MORE COLD AIR FOLLOWS BEHIND THE CLIPPER FOR TUESDAY INTO
WEDNESDAY ALONG WITH ANOTHER POTENTIAL FOR LIGHT SNOW AS
BAROCLINIC ZONE DEVELOPS IN THE AREA.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1141 PM CST WED JAN 28 2015
MVFR CONDITIONS HAVE OVERSPREAD THE AREA AND SHOULD LAST INTO
THURSDAY MORNING. SPRINKLES WILL BE POSSIBLE...BUT NOT
SIGNIFICANT ENOUGH TO MENTION. NORTHWEST WINDS 20 TO 30KTS WITH
GUSTS 30 TO 40KTS TONIGHT. THE NORTHWEST WINDS SHOULD DROP OFF
THURSDAY AS THE STRONGER WINDS ALOFT SHIFT TO THE EAST...GENERALLY
DROPPING TO UNDER 15KTS THURSDAY AFTERNOON AND UNDER 10KTS
THURSDAY NIGHT.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 7 AM CST THIS MORNING FOR NEZ015-030>034-
042>045-050>053-065>068-078-088>093.
WIND ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR NEZ011-012-
016>018.
IA...WIND ADVISORY UNTIL 7 AM CST THIS MORNING FOR IAZ043-055-056-069-
079-080-090-091.
&&
$$
SHORT TERM...FOBERT
LONG TERM...FOBERT
AVIATION...ZAPOTOCNY
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
203 AM EST THU JAN 29 2015
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFF TO THE SOUTHEAST OF THE REGION
TONIGHT...FOLLOWED BY AN ALBERTA CLIPPER WHICH WILL CROSS THE
AREA THURSDAY AND THURSDAY NIGHT. HIGH PRESSURE WILL RETURN FOR
LATE FRIDAY INTO SATURDAY. A NEW STORM MAY BRING A ROUND OF WINTRY
WEATHER FOR LATER SUNDAY INTO MONDAY...BEFORE ANOTHER SURGE OF
COLD AIR WORKS INTO THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
CLEAR SKIES...LIGHT WIND AND FRESH SNOW COVER ALLOWING TEMPS TO
FALL QUICKLY THIS EVENING. MESONET SHOWS SOME SUB-ZERO READINGS ALREADY
SHOWING UP ACROSS THE N MTNS AS OF 03Z. BASED ON AFTERNOON DWPTS
AND LATEST RAP OUTPUT...EXPECT THE COLDER VALLEYS OF THE
ALLEGHENIES TO BOTTOM OUT BTWN ZERO AND 10BLW AFTER MIDNIGHT.
UNDER SUCH AN IDEAL RAD COOLING SCENARIO...EXPECT WIDELY VARYING
MIN TEMPS...WITH 15F DIFFERENCES LIKELY WITHIN THE SAME
TOWNSHIPS. HAVE TRIED TO SETTLE ON AVG LOWS...WHICH WILL LKLY
RANGE FROM ARND ZERO ACROSS THE NW MTNS...TO ARND 10 ABV ACROSS
THE LOWER SUSQ VALLEY. WAA ALOFT AND ASSOC CIRRUS SHIELD WILL
LIKELY OVERSPREAD THE AREA FROM THE WEST TOWARD DAWN...RESULTING
IN RISING TEMPS LATE ACROSS THE WESTERN HALF OF THE STATE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
CLOUDS WILL THICKEN QUICKLY THURSDAY WITH WARM ADVECTION PRECIP
OVERSPREADING THE AREA DURING THE AFTERNOON. WE HAVE OPTED FOR A
LOW END ADVISORY FOR OUR WESTERN HIGHER ELEVATION COUNTIES FOR THE
POTENTIAL OF SEVERAL INCHES OF SNOW...WITH THE POSSIBILITY OF A
BRIEF PERIOD OF FREEZING RAIN AT THE ONSET.
MODELS ALL AGREE IN SHOVING A WEDGE OF WARM AIR ALOFT INTO THE
AREA THURSDAY MORNING...BUT FORECAST SOUNDINGS SHOW THE COLUMN
COOLING QUICKLY ONCE PRECIP STARTS SO THE THREAT FOR SIG ICING
WILL BE PRETTY SMALL. THINKING IS THAT A GENERAL 2-4INCH SNOWFALL
IS LIKELY OVER THE RIDGE COUNTIES...WITH A COATING TO PERHAPS AS
MUCH AS 3 INCHES FROM CENTRAL AREAS EASTWARD BEFORE THINGS WIND
DOWN THURSDAY NIGHT OR FRIDAY.
HIGHS THURSDAY WILL MAKE TO THE UPPER 20S TO AROUND FREEZING IN
THE BRISK SW FLOW AHEAD OF THE CLIPPER/ARCTIC FRONT.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
A STRONG SHOT OF WAA ALOFT AND MODERATELY STG UPPER LEVEL
DIVERGENCE ASSOCIATED WITH THE RIGHT ENTRANCE REGION OF AN
UPPER LVL JET MAX ACROSS SRN ONTARIO WILL LEAD TO PERIODS OF
LIGHT /TO BRIEFLY MDT SNOW/ FOCUSED ACROSS THE NW HALF OF THE
STATE LATER THU AFT INTO THURSDAY NIGHT. SOME FREEZING RAIN
COULD MIX IN EARLY...BUT UPWARD MOTION OFFSETS THE WARMING.
FCST TEMPS AT BUF COOLER NOW THAN YESTERDAY. THUS THINK MOST
OF OUR AREA WILL STAY MAINLY BELOW 32 ON THU. SOURCE REGION
OF THE AIRMASS IS FROM THE PLAINS. IT WAS IN THE 70S AND LOWER
80S ACROSS THE SOUTHERN PLAINS YESTERDAY...WARM THERE TODAY TOO.
SNOW WILL LINGER INTO EARLY FRIDAY...AS THE MAIN COLD FRONT DROPS
SE. IT WILL BE WINDY ON FRIDAY.
FRIDAY NIGHT WILL BE COLD...AS SKIES CLEAR AND WINDS DIE DOWN.
A BRIGHT DAY ON SAT...BUT NOT REAL WARM.
STILL HAVE CHC POPS ON SUNDAY. A LOT OF SPREAD IN THE MODEL OUTPUT
THE LAST FEW DAYS. 12Z MODELS BACKING OFF SOME NOW. PATTERN
SUPPORTS LOW PRESSURE SYSTEMS THAT ARE FAST MOVING AND WEAK. WOULD
STILL EXPECT SOME LIGHT SNOW INTO MONDAY MORNING.
A COLD NIGHT MONDAY NIGHT...AS THE NEXT HIGH BUILDS INTO
THE AREA.
SOME HINTS AT ANOTHER FAST MOVING LOW FOR MID WEEK...FOR NOW
WENT WITH CHC POPS.
MINOR CHANGES TO THE PACKAGE MADE.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
HIGH PRESSURE WILL MOVE EAST ACROSS THE STATE OVERNIGHT....BRINGING
WIDESPREAD VFR CONDITIONS. THE ONLY CAVEAT IS THE POSSIBILITY FOR
MVFR VSBYS AT BFD.
THURSDAY WILL BRING INCREASING CLOUDINESS WITH CONDITIONS
DETERIORATING IN SNOW STARTING AROUND MID DAY OVER WESTERN
TERMINALS...SPREADING RAPIDLY EAST THROUGH MID AFTERNOON.
REDUCED CONDITIONS WILL CONTINUE INTO EARLY FRIDAY.
OUTLOOK...
FRI...CONDITIONS IMPROVING DURING THE DAY...BUT REMAINING MVFR
OVER THE HIGHER ELEVATION TERMINALS OF THE WEST AND NORTH.
SAT...VFR.
SUN...RESTRICTIONS DEVELOPING WITH SNOW OVERSPREADING FROM THE
WEST.
MON...REDUCED CONDS EARLY IN SNOW. IMPROVING FROM WEST TO EAST
AFTERNOON ONWARD.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 11 AM THIS MORNING TO 7 AM EST
FRIDAY FOR PAZ004>006-010-011-017-024-033.
&&
$$
SYNOPSIS...FITZGERALD/LA CORTE
NEAR TERM...FITZGERALD
SHORT TERM...LA CORTE
LONG TERM...MARTIN
AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1146 PM CST WED JAN 28 2015
.AVIATION...
WINDS WERE AROUND 25 TO 40 KNOTS AROUND 1500 FEET AWAY FROM THE
COASTAL COUNTIES. OTHERWISE...THE NAMBUFR AND RAP13 SOUNDINGS SHOW
PATCHY GROUND FOG MAY BECOME MORE WIDESPREAD AFTER ABOUT 10Z. AT
LEAST MVFR AND POSSIBLY IFR/LIFR MAY BE PREVALENT BETWEEN 10Z AND
15Z. THE FORECAST SOUNDINGS ALSO INDICATE THAT VFR MAY NOT DEVELOP
AFTER 17Z. A FRONTAL BOUNDARY WILL THEN MOVE INTO SOUTHEAST TEXAS
TOWARD THE EARLY EVENING.
40
&&
.PREV DISCUSSION... /ISSUED 947 PM CST WED JAN 28 2015/
UPDATE...
WILL ISSUE A DENSE FOG ADVISORY FOR AREAS SOUTHWEST OF HOUSTON.
VISIBILITIES HAVE BEGUN TO DROP AND WINDS HAVE RELAXED A BIT. 43
PREV DISCUSSION... /ISSUED 823 PM CST WED JAN 28 2015/
UPDATE...
SEE EVENING UPDATE.
DISCUSSION...
AT 8 PM...SURFACE HIGH PRESSURE WAS LOCATED OVER THE NORTHERN GULF
COAST WITH A TROUGH LOW PRESSURE EXTENDING FROM EASTERN KANSAS
INTO NORTH CENTRAL TEXAS. THE PRESSURE GRADIENT BETWEEN THESE TWO
FEATURES IS RATHER TIGHT SO NOT EXPECTING WINDS TO FULLY DECOUPLE
OVERNIGHT. SFC TEMPS HAVE FALLEN TO NEAR THE DEW PT OVER THE SW
ZONES AND RAP13 FCST SOUNDINGS SHOW A VERY FAVORABLE PROFILE FOR
FOG DEVELOPMENT TONIGHT. THE HRRR IS HINTING AT FOG WITH
VISIBILITIES DROPPING TO BELOW A 1/2 MILE TONIGHT BUT JUST NOT
CONFIDENT ENOUGH TO GO WITH DENSE FOG AT THIS TIME DUE TO THE
SLIGHTLY STRONGER WINDS. WILL WATCH TRENDS CLOSELY AND IF WINDS
RELAX...A DENSE FOG ADVISORY MAY BE REQUIRED FOR THE SW HALF OF
THE REGION. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 53 72 43 57 45 / 0 10 10 10 20
HOUSTON (IAH) 54 73 47 60 46 / 0 10 10 10 10
GALVESTON (GLS) 56 70 51 57 50 / 0 10 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 9 AM CST THURSDAY FOR THE FOLLOWING
ZONES: BRAZORIA...FORT BEND...GALVESTON...JACKSON...
MATAGORDA...WHARTON.
GM...NONE.
&&
$$
DISCUSSION...43
AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS TOPEKA KS
632 AM CST Thu Jan 29 2015
.UPDATE...
Issued at 632 AM CST THU JAN 29 2015
The stronger wind gusts seems to be more isolated than earlier,
and overall obs show winds speeds below 30 MPH. With the RAP and
NAM showing the pressure gradient remaining at its current
magnitude or gradually weakening, will allow the wind advisory to
expire at 7 am. Nevertheless northwest winds of 15 to 25 MPH will
persist through much of the day.
&&
.SHORT TERM...(Today and Tonight)
Issued at 424 AM CST THU JAN 29 2015
A shortwave could be seen on the 08Z water vapor imagery passing
overhead into MO with a second shortwave moving southeast through SD
and WY. an upper level low pressure system was seen spinning well
off the Baja California coast and shortwaves within faster flow near
40N and 145W were moving towards the British Columbia coast. At the
surface, high pressure was building south through the central plains
causing gusty northwest winds from a tight pressure gradient. In
fact the gradient has been strong enough for sustained winds of
30 MPH and an occasional gust up to 45 MPH. Because of this, have
issued a wind advisory until 7 am. By then the pressure gradient
is expected to begin relaxing.
For today and tonight, the weather should remain relatively quiet
due to increasing dry air as the surface high pressure system
continues to move south. Because of this the shortwave over SD and
WY is not expected to do much in terms of sensible weather. However
subsidence behind this wave should help to erode away the low
stratus that has moved in, and think skies should clear out by the
late afternoon. Since there is not a lot of cold air behind this
front and models show the boundary layer mixing to almost 850MB,
think highs in the middle 40s looks reasonable. Lows tonight should
be a bit colder as the ridge axis moves in creating light winds with
clear skies. Expecting good radiational conditions, have adjusted
min temps down to around 20. Models show pretty high RH values
developing Friday morning suggestive of fog. Am not real confident
in fog formation since we have not had any meaningful precip lately
and soils remain very dry. Because of this think dewpoints are
likely to remain a couple degrees cooler than the air temp.
.LONG TERM...(Friday through Wednesday)
Issued at 424 AM CST THU JAN 29 2015
Gradual warm advection will take place through the day Friday
following a cold start and the arrival of the thicker high clouds
now appears will be delayed...therefore highs should recover back into
the low to middle 40s for highs.
Friday night...low and mid level warm air and moisture advection
will increase across the county warning area and persist into
Saturday. Although the atmosphere will initially be very dry
across the CWA...saturation will slowly occur west to east across
the CWA as warm air and moisture advection increases. Will maintain
a slight chance for precip over the north central in the
evening...with a increasing chances all areas overnight. Forecast
soundings Friday night continue to trend slightly warmer and
dewpoints increasing slightly as well. With still a fairly shallow
depth of warm air in place in the low levels...precip could fall as
rain or snow...although if surface temps fall to or below
freezing...precip would likely be snow. Will continue to carry a
rain/snow chance most areas Friday night...then mainly north of I 70
through Saturday. Areas south of I 70 should mainly be rain by
Saturday afternoon as freeze levels slowly increase in the
afternoon.
By late afternoon the GFS is the most aggressive with the arrival of
the colder air/front across the northern CWA with a possible
changeover to all snow which would slowly spread southward through
Saturday night. The EC and GEM are a little slower but still brings
the colder air southward through the night. Snow chances linger
through Sunday morning most areas...but should also decrease with
time as the main upper trough pushes through. At this
point...snowfall amounts look to be in the 1 to 2 inch range most
areas...but could be locally higher across the northern CWA if the
cold air moves in quicker.
After highs Saturday around 40...colder and blustery conditions will
be the rule Sunday with highs in the upper 20s to around 30 degrees.
Although wind speeds will decrease Sunday night...low temps in the 7
to 12 degree range will produce wind chills near zero.
Return flow to the south Monday should allow temps to recover back
into the upper 20s/lower 30s...then the lower 40s Tuesday before
another shortwave trough moving through the northern Plains pushes a
front through the area that night with slightly cooler highs in the
30s and low 40s on Wednesday. For now appears any snow chance will
remain north of the area.
&&
.AVIATION...(For the 12Z TAFs through 12Z Friday Morning)
Issued at 450 AM CST THU JAN 29 2015
Stratus continues to fill in from the north, and think it will
remain over the terminals for much of the day, until subsidence
from a second shortwave overspreads the area. For the most part
CIGS should remain above 2 KFT. Did lean on the optimistic side by
mixing CIGS above 3 KFT by noon based on the RAP forecast
soundings. But given how expansive the stratus is upstream, there
is some uncertainty in whether CIGS will lift and when they will
mix out. Gusty northwest and north winds will persist through the
day until the pressure gradient relaxes towards sunset.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY until 7 AM CST this morning FOR KSZ009>012-023-024-
026.
&&
$$
UPDATE...Wolters
SHORT TERM...Wolters
LONG TERM...63
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS TOPEKA KS
450 AM CST Thu Jan 29 2015
...AVIATION UPDATE...
.SHORT TERM...(Today and Tonight)
Issued at 424 AM CST THU JAN 29 2015
A shortwave could be seen on the 08Z water vapor imagery passing
overhead into MO with a second shortwave moving southeast through SD
and WY. an upper level low pressure system was seen spinning well
off the Baja California coast and shortwaves within faster flow near
40N and 145W were moving towards the British Columbia coast. At the
surface, high pressure was building south through the central plains
causing gusty northwest winds from a tight pressure gradient. In
fact the gradient has been strong enough for sustained winds of
30 MPH and an occasional gust up to 45 MPH. Because of this, have
issued a wind advisory until 7 am. By then the pressure gradient
is expected to begin relaxing.
For today and tonight, the weather should remain relatively quiet
due to increasing dry air as the surface high pressure system
continues to move south. Because of this the shortwave over SD and
WY is not expected to do much in terms of sensible weather. However
subsidence behind this wave should help to erode away the low
stratus that has moved in, and think skies should clear out by the
late afternoon. Since there is not a lot of cold air behind this
front and models show the boundary layer mixing to almost 850MB,
think highs in the middle 40s looks reasonable. Lows tonight should
be a bit colder as the ridge axis moves in creating light winds with
clear skies. Expecting good radiational conditions, have adjusted
min temps down to around 20. Models show pretty high RH values
developing Friday morning suggestive of fog. Am not real confident
in fog formation since we have not had any meaningful precip lately
and soils remain very dry. Because of this think dewpoints are
likely to remain a couple degrees cooler than the air temp.
.LONG TERM...(Friday through Wednesday)
Issued at 424 AM CST THU JAN 29 2015
Gradual warm advection will take place through the day Friday
following a cold start and the arrival of the thicker high clouds
now appears will be delayed...therefore highs should recover back into
the low to middle 40s for highs.
Friday night...low and mid level warm air and moisture advection
will increase across the county warning area and persist into
Saturday. Although the atmosphere will initially be very dry
across the CWA...saturation will slowly occur west to east across
the CWA as warm air and moisture advection increases. Will maintain
a slight chance for precip over the north central in the
evening...with a increasing chances all areas overnight. Forecast
soundings Friday night continue to trend slightly warmer and
dewpoints increasing slightly as well. With still a fairly shallow
depth of warm air in place in the low levels...precip could fall as
rain or snow...although if surface temps fall to or below
freezing...precip would likely be snow. Will continue to carry a
rain/snow chance most areas Friday night...then mainly north of I 70
through Saturday. Areas south of I 70 should mainly be rain by
Saturday afternoon as freeze levels slowly increase in the
afternoon.
By late afternoon the GFS is the most aggressive with the arrival of
the colder air/front across the northern CWA with a possible
changeover to all snow which would slowly spread southward through
Saturday night. The EC and GEM are a little slower but still brings
the colder air southward through the night. Snow chances linger
through Sunday morning most areas...but should also decrease with
time as the main upper trough pushes through. At this
point...snowfall amounts look to be in the 1 to 2 inch range most
areas...but could be locally higher across the northern CWA if the
cold air moves in quicker.
After highs Saturday around 40...colder and blustery conditions will
be the rule Sunday with highs in the upper 20s to around 30 degrees.
Although wind speeds will decrease Sunday night...low temps in the 7
to 12 degree range will produce wind chills near zero.
Return flow to the south Monday should allow temps to recover back
into the upper 20s/lower 30s...then the lower 40s Tuesday before
another shortwave trough moving through the northern Plains pushes a
front through the area that night with slightly cooler highs in the
30s and low 40s on Wednesday. For now appears any snow chance will
remain north of the area.
&&
.AVIATION...(For the 12Z TAFs through 12Z Friday Morning)
Issued at 450 AM CST THU JAN 29 2015
Stratus continues to fill in from the north, and think it will
remain over the terminals for much of the day, until subsidence
from a second shortwave overspreads the area. For the most part
CIGS should remain above 2 KFT. Did lean on the optimistic side by
mixing CIGS above 3 KFT by noon based on the RAP forecast
soundings. But given how expansive the stratus is upstream, there
is some uncertainty in whether CIGS will lift and when they will
mix out. Gusty northwest and north winds will persist through the
day until the pressure gradient relaxes towards sunset.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY until 7 AM CST this morning FOR KSZ009>012-023-024-
026.
&&
$$
SHORT TERM...Wolters
LONG TERM...63
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS JACKSON KY
1014 AM EST THU JAN 29 2015
.UPDATE...
ISSUED AT 1013 AM EST THU JAN 29 2015
WITH REPORTS OF MANY ACCIDENTS...ISSUED AN FREEZING RAIN ADVISORY FOR
LOCATIONS WHERE VALLEYS TEMPS ARE BELOW FREEZING AND PRECIP IS STILL
OCCURRING. TEMPS ARE WARMING...SO THE ADVISORY ONLY RUNS FOR ABOUT
ANOTHER HOUR. WILL EVALUATE TEMPS IN A WHILE TO SEE IF IT CAN EXPIRE.
UPDATE ISSUED AT 844 AM EST THU JAN 29 2015
PRECIP SHIELD HAS MADE INTO OUR WESTERN FORECAST AREA. TEMPERATURES
HAVE RESPONDED WELL WHERE MEASURABLE PRECIPITATION IS
FALLING...HOWEVER SOME VALLEYS IN THE EAST STILL LINGER IN THE MID
20S. LOOKING AT RADAR TRENDS...THE MEASURABLE PRECIPITATION SEEMS TO
BE HAVING A HARDER TIME COMING EAST WITH SOME DOWNSLOPE FLOW IN
PLACE...AND READINGS HAVE BEEN EDGING UP EVEN IN THE COLDER SPOTS
PRIOR TO THE PRECIP ARRIVING. HAVE BEEFED UP POPS TO CATEGORICAL
ACROSS THE BOARD...AND WILL CONTINUE TO MENTION A CHANCE OF FREEZING
RAIN...AS SOME SPOTTY SLICK SPOTS STILL LOOK POSSIBLE. UPDATES HAVE
BEEN SENT.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 400 AM EST THU JAN 29 2015
LATEST SURFACE MAP FEATURES HIGH PRESSURE ALONG THE EASTERN
CONUS...WITH LOW PRESSURE MOVING INTO THE GREAT LAKES AND OHIO VALLEY
REGIONS. ALOFT...A SHORT WAVE TROUGH IS ROTATING TOWARDS THE OHIO
VALLEY...WITH ANOTHER TROUGH DROPPING SOUTHEAST INTO THE NORTHERN
PLAINS...AND YET ONE MORE MOVING IN ACROSS SOUTH CENTRAL CANADA.
MAINLY MID AND HIGH LEVEL CLOUDS HAVE BEEN STREAMING IN ACROSS
EASTERN KENTUCKY. THE SOUTHERLY WIND FLOW OUT AHEAD OF THE
APPROACHING SURFACE LOW HAS ALLOWED FOR A NICE RIDGE/VALLEY SPLIT
ACROSS THE AREA...WITH MORE SHELTERED VALLEYS HOLDING IN THE LOW AND
MID 20S...WHILE RIDGETOPS ARE IN THE LOW TO MID 30S.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM...TAKING THE
LOW PRESSURE SYSTEM EAST ACROSS THE OHIO VALLEY DURING THE DAY...AND
ALLOWING THE ASSOCIATED SURFACE COLD FRONT TO MOVE THROUGH THE AREA
THIS AFTERNOON INTO EARLY THIS EVENING. MEANWHILE...THE MORE NORTHERN
SHORT WAVES WILL CONTINUE TO DROP SOUTHEAST IN SUCCESSION...HELPING
TO ESTABLISH A DEEP TROUGH ACROSS THE EAST BY FRIDAY.
THE CURRENT RADAR SHOWS A BAND OF LIGHT RAIN FROM SOUTH CENTRAL
INDIANA DOWN THROUGH WESTERN KENTUCKY. THE LATEST HRRR SHOWS THIS
ACTIVITY MAKING IT TO OUR DOORSTEP BY DAWN OR SHORTLY THEREAFTER...
ALTHOUGH THERE IS GOOD AGREEMENT THAT THE MAJORITY OF THE MEASURABLE
PRECIPITATION WILL STAY JUST NORTH...WITH MORE SPOTTIER ACTIVITY TO
CONTEND WITH ACROSS OUR AREA THROUGH 14Z. AFTER 14Z...PRECIPITATION
LOOKS TO BLOSSOM AS THE BETTER FORCING ARRIVES. HAVE BEEN CONCERNED
WITH THE COLD VALLEY READINGS ACROSS OUR AREA...HOWEVER IT LOOKS AS
THOUGH THAT BY THE TIME THE BETTER PRECIPITATION DOES MOVE IN...THAT
MOST LOCATIONS WILL BE ABOVE FREEZING. AS SUCH...WILL ISSUE A SPECIAL
WEATHER STATEMENT COVERING THE SPOTTIER PRECIPITATION AT ONSET...AS
MAINLY INTERIOR LOCATIONS WILL STILL LIKELY BE BELOW FREEZING. WILL
CONTINUE TO MONITOR TRENDS VERY CLOSELY OVER THE NEXT FEW HOURS SINCE
ANY RAMP UP IN THE PRECIPITATION WILL MEAN AN ICY COMMUTE POTENTIALLY.
ONCE THE FIRST BATCH OF PRECIP MOVES THROUGH LATER THIS MORNING INTO
EARLY THIS AFTERNOON...THERE WILL LIKELY BE A LULL IN THE
ACTIVITY...BEFORE THE COLDER AIR ARRIVES ON NORTHWEST WINDS AND THE
TROUGH AXIS MOVES THROUGH TONIGHT. THIS WILL ALLOW FOR SOME LIGHT
SNOW ACROSS THE AREA. SNOW SHOWERS WILL LIKELY LINGER IN THE EAST
THROUGH FRIDAY MORNING...BEFORE TAPERING OFF. ANY LIGHT ACCUMULATIONS
WILL FAVOR THE HIGHER TERRAIN IN THE FAR SOUTHEAST.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 446 AM EST THU JAN 29 2015
HIGH PRESSURE WILL TAKE HOLD OF SENSIBLE WEATHER TO BEGIN THIS
PERIOD. WHILE LOW PRESSURE THAT IS AFFECTING THE REGION TODAY
DEVELOPS INTO ANOTHER STRONG COASTAL LOW ACROSS THE NORTHEAST US.
THIS HIGH PRESSURE COUPLED WITH DECREASING CLOUDS WILL ALLOW FOR
DECOUPLING AND LOWS DROPPING DOWN INTO THE MID TO UPPER TEENS
AREA WIDE. THIS HIGH PRESSURE WILL ALLOW MOSTLY SUNNY SKIES EARLY IN
THE DAY FOR YOUR SATURDAY WITH INCREASING CLOUDS IN THE AFTERNOON.
WINDS WILL ALSO BECOME MORE SOUTHWEST BRINGING HIGHS ON SATURDAY INTO
THE UPPER 30S TO LOWER 40S.
NOW THE BIGGER CONCERN CONTINUES TO BE LATE WEEKEND STORM AND
CONFIDENCE REMAINS LOW IN REGARDS TO THIS SYSTEM. THE SETUP IS WE
HAVE A DEVELOPING UPPER LEVEL CLOSED LOW ACROSS THE NORTHERN BAJA
PENINSULA AND ASSOCIATED DEVELOPING SURFACE LOW SATURDAY MORNING.
MEANWHILE A UPPER LEVEL WAVE RIDES OVER RIDGING ACROSS THE NORTHWEST
US. THEN THIS IS WHERE THE MODELS CONTINUE TO STRUGGLE IS IN THE
PHASING PROCESS THAT OCCURS SATURDAY NIGHT IN THE UPPER LEVELS.
EARLIER THE 18Z/28 GFS AND 12Z/28 ECMWF HAD A MORE OPEN WAVE WHICH
TRANSLATED TO A WEAKER SURFACE LOW. THIS WAS NEW BASED ON THE
PREVIOUS RUNS SEEN OVER THE PAST COUPLE OF DAYS. THE LATEST 00Z/29
RUN OF THE GFS DEVELOPS A STRONGER LOW WITH A BIT OF A DEEPER TROUGH
SETTING UP. THE 00Z/29 ECMWF DOES HAVE SIMILARITIES...HOWEVER THE
SURFACE LOW PRESSURE IS NOT AS DEEP. ONE THING THAT REMAINS WITH BOTH
MODELS 00Z RUNS IS BOTH HAVE A GOOD AMT OF QPF RESPECTIVELY. ANOTHER
QUESTION THAT REMAINS IS HOW MUCH COLD AIR STAYS IN PLACE WITH THIS
SYSTEM ON SUNDAY AND THIS WILL DEPEND HEAVILY ON THE EVENTUAL TRACK
OF THIS SURFACE LOW. THAT SAID HAVE LEANED TOWARD A BIT COLDER
THROUGH THE DAY ON SUNDAY. THINKING STILL MUCH OF SUNDAY WOULD LEAD
TO MIXING ACROSS MUCH OF THE CWA WITH MORE IN THE WAY OF SNOW ACROSS
THE BLUEGRASS WHERE TEMPS REMAIN COOLER...HOWEVER CONFIDENCE IN THIS
SYSTEM REMAINS LOW GIVEN THE DRASTIC RUN TO RUN CHANGES SEEN IN THE
DETERMINISTIC MODELS. ALSO KEEPING IN MIND THAT THE ENSEMBLE MEAN HAS
BEEN QUITE ERRATIC AND GIVEN THAT THE 12 PERTURBATIONS IN OUR SYSTEM
ARE ERRATIC EXPLAINS THE LACK OF CONTINUITY. ALL THIS SAID STILL
THINK THERE IS A REASONABLE SHOT OF MEASURABLE SNOW SUNDAY INTO
MONDAY. ANOTHER PIECE TO THE PUZZLE TO KEEP IN MIND IS THAT A MORE
NORTHERLY TRACK SHOWN IN EARLIER RUNS COULD ALLOW FOR MORE SOUTHERLY
FLOW AND WARMER AIR AND LEAD TO LESSENING SNOWFALL TOTALS. ALTHOUGH
BEHIND THIS SYSTEM EXPECT COLD AIR TO FILTER INTO ALL OF THE CWA
SUNDAY NIGHT INTO MONDAY. ALSO WOULD EXPECT GENERALLY FALLING
TEMPERATURES DURING THE DAY ON MONDAY.
AFTER THIS THE AFOREMENTIONED LOW PRESSURE IS THEN FORECAST TO TRACK NE
AND CONTINUE TO DEEPEN ALONG NE ATLANTIC COAST. HIGH PRESSURE WILL
BUILD EAST MONDAY NIGHT AND EXPECT ANOTHER COLD NIGHT WITH GENERALLY
LOW TO MID TEENS ACROSS THE REGION. THESE TEMPS MAY HAVE TO BE
ADJUSTED FURTHER DEPENDING UPON IF WE RECEIVE MEASURABLE SNOW. THIS
HIGH PRESSURE WILL ADVANCE EAST OF THE REGION MOVING INTO THE DAY ON
TUESDAY BRINGING RETURN FLOW AND WELCOMING REBOUND IN
TEMPERATURE...WITH HIGHS IN THE MID TO UPPER 30S. THAT SAID WEDNESDAY
REMAINS UNCERTAIN WITH YET ANOTHER SYSTEM DEVELOPING AND AT THIS POINT
STUCK CLOSE TO THE BLEND. DID INTRODUCE MAINLY SLIGHT POPS DURING
THAT PORTION OF THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 844 AM EST THU JAN 29 2015
A PASSING COLD FRONT WILL BRING LOWERING CEILINGS...PRECIPITATION...
AND GUSTY SOUTH TO SOUTHWEST WINDS TO THE AREA THROUGH THIS EVENING.
VFR CONDITIONS WILL LIKELY HOLD ON THROUGH THE EARLY
AFTERNOON...BEFORE CEILINGS LIKELY COME DOWN QUICKLY TO MVFR/IFR ONCE
THE FRONT MOVES THROUGH THE AREA LATER THIS AFTERNOON INTO EARLY THIS
EVENING. PRECIPITATION WILL TAPER OFF THIS MORNING...AND THEN LOOKS
TO PICK UP AGAIN TONIGHT AS AN UPPER TROUGH AXIS MOVES ACROSS THE OHIO
AND TENNESSEE VALLEYS. COLDER AIR WILL MOVE IN ON NORTHWEST
WINDS...WITH RAIN CHANGING OVER TO SNOW. SOUTH TO SOUTHWEST WINDS OF
10 TO 15 KTS...WITH GUSTS IN THE 15 TO 20 KT RANGE WILL SHIFT TO THE
WEST AND EVENTUALLY NORTHWEST. THE WINDS WILL DIMINISH AND BECOME
LESS GUSTY AFTER DUSK.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL 11 AM EST THIS MORNING FOR KYZ107-
109-110-112-113-115-117-119-120.
&&
$$
UPDATE...HAL
SHORT TERM...GEOGERIAN
LONG TERM...DJ
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS PADUCAH KY
905 AM CST Thu Jan 29 2015
.UPDATE...
Issued at 905 AM CST THU JAN 29 2015
The forecast has been updated to catch up to the cloud and
temperature trends. Much of west Kentucky will have highs greater
than forecast late this morning. Also, the latest HRRR has no
precipitation over the area through the day, so removed all
measurable PoPs. Would not rule out some patchy drizzle across the
Evansville Tri State region this afternoon, but will add that in
once it becomes more obvious.
UPDATE issued at 545 AM CST Thu Jan 29 2015
Updated aviation section for 12z tafs
&&
.SHORT TERM (Today through Saturday)...
Issued at 255 AM CST Thu Jan 29 2015
A well-defined cold front will move quickly southeast across our
region this morning. A small line of showers developed well ahead
of the front from kowb to khop early this morning. Cannot rule out
another small line until the front passes to our east. For most of
the forecast area, this will be a dry frontal passage.
Behind the front, winds will shift into the northwest and become
rather gusty today. Some gusts around 25 knots are likely. NAM and
GFS 925 mb rh progs indicate widespread low cloudiness will arrive
behind the front and persist through the afternoon. Low level cold
advection and widespread cloudiness should result in a steady or
slowly falling temperature trend this afternoon. Highs will be in
the morning. A period of sunshine prior to the arrival of low
clouds could push temps up from their 08z readings in the mid 40s
to lower 50s.
The main forecast issue for tonight is when and if the low clouds
will clear out. 925 mb rh forecasts from the 00z nam and gfs are
quite moist all night, especially east of the Mississippi River.
The forecast will show partial clearing from west to east tonight,
but at a slower rate than previous forecasts. Lows will be in the
mid to upper 20s.
Friday still looks mostly sunny, although there may still be some
morning low clouds in southwest Indiana and northwest Kentucky.
Winds will decrease as surface high pressure reaches the mid and
upper Mississippi Valley. Highs should be quite cold considering
the amount of sun, ranging from the mid 30s to lower 40s.
Friday night and Saturday...mid and high clouds will gradually
increase ahead of the next system. The low levels will be
extremely dry, which should make it very difficult for precip to
reach the ground. Will keep in a slight chance of showers in the
Ozark foothills of southeast Missouri. Despite the clouds, highs
should be mainly in the lower and mid 40s due to southerly winds.
.LONG TERM (Saturday night through Wednesday)...
Issued at 300 AM CST Thu Jan 29 2015
Main forecast challenge in this time frame comes with the storm
system that looks to be impacting the region over the weekend,
especially Sunday. Forecast confidence remains fairly low at this
time regarding precip types.
As we begin the period, split mid/upper flow pattern should be in
place...with nrn branch trof digging se into the Plains and a nearly
stationary srn branch low in place over the Baja of CA. It now looks
as though the srn branch low will feed pacific moisture into the nrn
branch...leading to fairly widespread precip shield over the mid MS
River and Ohio Valleys Saturday night and esp Sunday as sfc low
pressure develops over the Gulf Coast states. As mentioned, the main
uncertainly at this time lies with precip type. The latest 00z runs
of the operational GFS and ECMWF are now in decent agreement that
the sfc low and inverted trof will remain farther south over
MS/AL...as a 1040 mb sfc high presses south into the nrn Plains.
This would result in a colder thermal profile than we were thinking
yesterday. Snow would be the main precip type over all except our
far southern counties, with some potential for a few inches, esp
along and north/west of the Ohio River. On the other hand for
example, 00Z NAM/GEM both bring the sfc low farther north, and are
thus much warmer in their thermal profiles. For this package, will
keep much of the nrn half of the forecast area mostly snow, and go
with rain/snow for now over much of wrn KY and se MO. Again,
uncertainty is still quite high and things are likely to change one
way or another as we get closer to the event.
Very cold air will follow in the wake of the system as Canadian high
pressure moves se into the region. Most locations will fall into the
teens later Sunday night and Monday night. Highs Monday will likely
remain below freezing. Of course, things could be even colder if any
areas manage to get a fresh layer of snow on the ground. The next
clipper system Tue/Tue night is expected to stay much farther north
and cross over the Great lakes region. May be some light precip as
it drags another cold front across the region, but most impacts with
this low are expected to remain north of the forecast area.
&&
.AVIATION...
Issued at 545 AM CST Thu Jan 29 2015
The back edge of mid level clouds and sprinkles will move east of
the kevv/kowb area early this morning. Clear skies are expected for
a few hours before a strong cold front moves through around mid
morning. As the front passes, winds will shift into the
west/northwest and gust around 25 knots. A solid deck of mvfr cigs
will also arrive as the front passes. The mvfr cigs will likely be
slow to depart. In fact, the kevv/kowb sites should remain overcast
through Friday morning. Winds will diminish to around 10 knots
around sunset.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...MY
LONG TERM....GM
AVIATION...MY
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
844 AM EST THU JAN 29 2015
.UPDATE...
ISSUED AT 844 AM EST THU JAN 29 2015
PRECIP SHIELD HAS MADE INTO OUR WESTERN FORECAST AREA. TEMPERATURES
HAVE RESPONDED WELL WHERE MEASURABLE PRECIPITATION IS
FALLING...HOWEVER SOME VALLEYS IN THE EAST STILL LINGER IN THE MID
20S. LOOKING AT RADAR TRENDS...THE MEASURABLE PRECIPITATION SEEMS TO
BE HAVING A HARDER TIME COMING EAST WITH SOME DOWNSLOPE FLOW IN
PLACE...AND READINGS HAVE BEEN EDGING UP EVEN IN THE COLDER SPOTS
PRIOR TO THE PRECIP ARRIVING. HAVE BEEFED UP POPS TO CATEGORICAL
ACROSS THE BOARD...AND WILL CONTINUE TO MENTION A CHANCE OF FREEZING
RAIN...AS SOME SPOTTY SLICK SPOTS STILL LOOK POSSIBLE. UPDATES HAVE
BEEN SENT.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 400 AM EST THU JAN 29 2015
LATEST SURFACE MAP FEATURES HIGH PRESSURE ALONG THE EASTERN
CONUS...WITH LOW PRESSURE MOVING INTO THE GREAT LAKES AND OHIO VALLEY
REGIONS. ALOFT...A SHORT WAVE TROUGH IS ROTATING TOWARDS THE OHIO
VALLEY...WITH ANOTHER TROUGH DROPPING SOUTHEAST INTO THE NORTHERN
PLAINS...AND YET ONE MORE MOVING IN ACROSS SOUTH CENTRAL CANADA.
MAINLY MID AND HIGH LEVEL CLOUDS HAVE BEEN STREAMING IN ACROSS
EASTERN KENTUCKY. THE SOUTHERLY WIND FLOW OUT AHEAD OF THE
APPROACHING SURFACE LOW HAS ALLOWED FOR A NICE RIDGE/VALLEY SPLIT
ACROSS THE AREA...WITH MORE SHELTERED VALLEYS HOLDING IN THE LOW AND
MID 20S...WHILE RIDGETOPS ARE IN THE LOW TO MID 30S.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM...TAKING THE
LOW PRESSURE SYSTEM EAST ACROSS THE OHIO VALLEY DURING THE DAY...AND
ALLOWING THE ASSOCIATED SURFACE COLD FRONT TO MOVE THROUGH THE AREA
THIS AFTERNOON INTO EARLY THIS EVENING. MEANWHILE...THE MORE NORTHERN
SHORT WAVES WILL CONTINUE TO DROP SOUTHEAST IN SUCCESSION...HELPING
TO ESTABLISH A DEEP TROUGH ACROSS THE EAST BY FRIDAY.
THE CURRENT RADAR SHOWS A BAND OF LIGHT RAIN FROM SOUTH CENTRAL
INDIANA DOWN THROUGH WESTERN KENTUCKY. THE LATEST HRRR SHOWS THIS
ACTIVITY MAKING IT TO OUR DOORSTEP BY DAWN OR SHORTLY THEREAFTER...
ALTHOUGH THERE IS GOOD AGREEMENT THAT THE MAJORITY OF THE MEASURABLE
PRECIPITATION WILL STAY JUST NORTH...WITH MORE SPOTTIER ACTIVITY TO
CONTEND WITH ACROSS OUR AREA THROUGH 14Z. AFTER 14Z...PRECIPITATION
LOOKS TO BLOSSOM AS THE BETTER FORCING ARRIVES. HAVE BEEN CONCERNED
WITH THE COLD VALLEY READINGS ACROSS OUR AREA...HOWEVER IT LOOKS AS
THOUGH THAT BY THE TIME THE BETTER PRECIPITATION DOES MOVE IN...THAT
MOST LOCATIONS WILL BE ABOVE FREEZING. AS SUCH...WILL ISSUE A SPECIAL
WEATHER STATEMENT COVERING THE SPOTTIER PRECIPITATION AT ONSET...AS
MAINLY INTERIOR LOCATIONS WILL STILL LIKELY BE BELOW FREEZING. WILL
CONTINUE TO MONITOR TRENDS VERY CLOSELY OVER THE NEXT FEW HOURS SINCE
ANY RAMP UP IN THE PRECIPITATION WILL MEAN AN ICY COMMUTE POTENTIALLY.
ONCE THE FIRST BATCH OF PRECIP MOVES THROUGH LATER THIS MORNING INTO
EARLY THIS AFTERNOON...THERE WILL LIKELY BE A LULL IN THE
ACTIVITY...BEFORE THE COLDER AIR ARRIVES ON NORTHWEST WINDS AND THE
TROUGH AXIS MOVES THROUGH TONIGHT. THIS WILL ALLOW FOR SOME LIGHT
SNOW ACROSS THE AREA. SNOW SHOWERS WILL LIKELY LINGER IN THE EAST
THROUGH FRIDAY MORNING...BEFORE TAPERING OFF. ANY LIGHT ACCUMULATIONS
WILL FAVOR THE HIGHER TERRAIN IN THE FAR SOUTHEAST.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 446 AM EST THU JAN 29 2015
HIGH PRESSURE WILL TAKE HOLD OF SENSIBLE WEATHER TO BEGIN THIS
PERIOD. WHILE LOW PRESSURE THAT IS AFFECTING THE REGION TODAY
DEVELOPS INTO ANOTHER STRONG COASTAL LOW ACROSS THE NORTHEAST US.
THIS HIGH PRESSURE COUPLED WITH DECREASING CLOUDS WILL ALLOW FOR
DECOUPLING AND LOWS DROPPING DOWN INTO THE MID TO UPPER TEENS
AREA WIDE. THIS HIGH PRESSURE WILL ALLOW MOSTLY SUNNY SKIES EARLY IN
THE DAY FOR YOUR SATURDAY WITH INCREASING CLOUDS IN THE AFTERNOON.
WINDS WILL ALSO BECOME MORE SOUTHWEST BRINGING HIGHS ON SATURDAY INTO
THE UPPER 30S TO LOWER 40S.
NOW THE BIGGER CONCERN CONTINUES TO BE LATE WEEKEND STORM AND
CONFIDENCE REMAINS LOW IN REGARDS TO THIS SYSTEM. THE SETUP IS WE
HAVE A DEVELOPING UPPER LEVEL CLOSED LOW ACROSS THE NORTHERN BAJA
PENINSULA AND ASSOCIATED DEVELOPING SURFACE LOW SATURDAY MORNING.
MEANWHILE A UPPER LEVEL WAVE RIDES OVER RIDGING ACROSS THE NORTHWEST
US. THEN THIS IS WHERE THE MODELS CONTINUE TO STRUGGLE IS IN THE
PHASING PROCESS THAT OCCURS SATURDAY NIGHT IN THE UPPER LEVELS.
EARLIER THE 18Z/28 GFS AND 12Z/28 ECMWF HAD A MORE OPEN WAVE WHICH
TRANSLATED TO A WEAKER SURFACE LOW. THIS WAS NEW BASED ON THE
PREVIOUS RUNS SEEN OVER THE PAST COUPLE OF DAYS. THE LATEST 00Z/29
RUN OF THE GFS DEVELOPS A STRONGER LOW WITH A BIT OF A DEEPER TROUGH
SETTING UP. THE 00Z/29 ECMWF DOES HAVE SIMILARITIES...HOWEVER THE
SURFACE LOW PRESSURE IS NOT AS DEEP. ONE THING THAT REMAINS WITH BOTH
MODELS 00Z RUNS IS BOTH HAVE A GOOD AMT OF QPF RESPECTIVELY. ANOTHER
QUESTION THAT REMAINS IS HOW MUCH COLD AIR STAYS IN PLACE WITH THIS
SYSTEM ON SUNDAY AND THIS WILL DEPEND HEAVILY ON THE EVENTUAL TRACK
OF THIS SURFACE LOW. THAT SAID HAVE LEANED TOWARD A BIT COLDER
THROUGH THE DAY ON SUNDAY. THINKING STILL MUCH OF SUNDAY WOULD LEAD
TO MIXING ACROSS MUCH OF THE CWA WITH MORE IN THE WAY OF SNOW ACROSS
THE BLUEGRASS WHERE TEMPS REMAIN COOLER...HOWEVER CONFIDENCE IN THIS
SYSTEM REMAINS LOW GIVEN THE DRASTIC RUN TO RUN CHANGES SEEN IN THE
DETERMINISTIC MODELS. ALSO KEEPING IN MIND THAT THE ENSEMBLE MEAN HAS
BEEN QUITE ERRATIC AND GIVEN THAT THE 12 PERTURBATIONS IN OUR SYSTEM
ARE ERRATIC EXPLAINS THE LACK OF CONTINUITY. ALL THIS SAID STILL
THINK THERE IS A REASONABLE SHOT OF MEASURABLE SNOW SUNDAY INTO
MONDAY. ANOTHER PIECE TO THE PUZZLE TO KEEP IN MIND IS THAT A MORE
NORTHERLY TRACK SHOWN IN EARLIER RUNS COULD ALLOW FOR MORE SOUTHERLY
FLOW AND WARMER AIR AND LEAD TO LESSENING SNOWFALL TOTALS. ALTHOUGH
BEHIND THIS SYSTEM EXPECT COLD AIR TO FILTER INTO ALL OF THE CWA
SUNDAY NIGHT INTO MONDAY. ALSO WOULD EXPECT GENERALLY FALLING
TEMPERATURES DURING THE DAY ON MONDAY.
AFTER THIS THE AFOREMENTIONED LOW PRESSURE IS THEN FORECAST TO TRACK NE
AND CONTINUE TO DEEPEN ALONG NE ATLANTIC COAST. HIGH PRESSURE WILL
BUILD EAST MONDAY NIGHT AND EXPECT ANOTHER COLD NIGHT WITH GENERALLY
LOW TO MID TEENS ACROSS THE REGION. THESE TEMPS MAY HAVE TO BE
ADJUSTED FURTHER DEPENDING UPON IF WE RECEIVE MEASURABLE SNOW. THIS
HIGH PRESSURE WILL ADVANCE EAST OF THE REGION MOVING INTO THE DAY ON
TUESDAY BRINGING RETURN FLOW AND WELCOMING REBOUND IN
TEMPERATURE...WITH HIGHS IN THE MID TO UPPER 30S. THAT SAID WEDNESDAY
REMAINS UNCERTAIN WITH YET ANOTHER SYSTEM DEVELOPING AND AT THIS POINT
STUCK CLOSE TO THE BLEND. DID INTRODUCE MAINLY SLIGHT POPS DURING
THAT PORTION OF THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 844 AM EST THU JAN 29 2015
A PASSING COLD FRONT WILL BRING LOWERING CEILINGS...PRECIPITATION...
AND GUSTY SOUTH TO SOUTHWEST WINDS TO THE AREA THROUGH THIS EVENING.
VFR CONDITIONS WILL LIKELY HOLD ON THROUGH THE EARLY
AFTERNOON...BEFORE CEILINGS LIKELY COME DOWN QUICKLY TO MVFR/IFR ONCE
THE FRONT MOVES THROUGH THE AREA LATER THIS AFTERNOON INTO EARLY THIS
EVENING. PRECIPITATION WILL TAPER OFF THIS MORNING...AND THEN LOOKS
TO PICK UP AGAIN TONIGHT AS AN UPPER TROUGH AXIS MOVES ACROSS THE OHIO
AND TENNESSEE VALLEYS. COLDER AIR WILL MOVE IN ON NORTHWEST
WINDS...WITH RAIN CHANGING OVER TO SNOW. SOUTH TO SOUTHWEST WINDS OF
10 TO 15 KTS...WITH GUSTS IN THE 15 TO 20 KT RANGE WILL SHIFT TO THE
WEST AND EVENTUALLY NORTHWEST. THE WINDS WILL DIMINISH AND BECOME
LESS GUSTY AFTER DUSK.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...GEOGERIAN
LONG TERM...DJ
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
727 AM EST THU JAN 29 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 457 AM EST THU JAN 29 2015
WV AND LATEST RADAR IMAGERY SHOW IT WELL...THE DEEP MOISTURE SET UP
ACROSS CENTRAL UPPER MI IS QUICKLY EXITING E. THE SFC TROUGH SET UP
OVER W LAKE SUPERIOR AROUND 09Z THIS MORNING WILL EDGE TO THE E HALF
OF THE CWA SHORTLY AFTER DAYBREAK THIS IS WHEN WE WILL REALLY BEGIN
TO NOTICE SOME OF THOSE STRONGER N-NNW WINDS BEGIN /WINDS CURRENTLY
AROUND 12KTS AT CMX WILL BEGIN TO GUSTS 25-30KTS/.
-FZDZ HAS BEEN REPORTED OFF AND ON THIS MORNING AS THE MAIN BULK OF
MOISTURE EXISTS OVER CENTRAL AND E UPPER MI...AS STRONG HIGH
PRESSURE OVER CENTRAL SASKATCHEWAN NEARS. UTILIZED THE PROBABILITY
OF ICE PRESENT FROM THE RUC TO GET A BETTER HANDLE ON WHEN AND WHERE
-FZDZ MAY SET UP BEFORE COLD AIR PUSHES ACROSS ALL OF UPPER MI
/BASICALLY BY 18Z/ FOR ANY LINGERING MIXED PRECIP TO TRANSITION BACK
TO JUST -SHSN. LOOK FOR FALLING TEMPS THIS AFTERNOON AS THE COLDER
AIR SLIDES IN. 850MB TEMPS AROUND -10C EARLY THIS MORNING WILL FALL
THIS AFTERNOON...AND GET DOWN TO AROUND -17C BY 00Z...AND -20C BY
06Z FRIDAY. THE ARRIVAL OF THE COLDER AIR WILL BRING A BETTER CHANCE
OF LAKE EFFECT SNOW SHOWERS TO UPSLOPE LOCATIONS OVER THE W FAVORED
BY NNW WINDS.
LIMITING FACTORS FOR SIGNIFICANT SNOW ACCUMULATIONS OVER THE W THIRD
OF THE CWA LATER THIS AFTERNOON THROUGH THIS EVENING WILL BE THE
LOWERING DGZ TO AROUND 4KFT OR LESS BY 06Z FRIDAY...WINDS STILL
GUSTING 15-20KTS WILL KEEP SLR VALUES FROM RISING BACK UP TO
25:1 TOO FAST. HOWEVER...WITH THE 500MB TROUGH OVERHEAD AND AN
ADDITIONAL SHORTWAVE SLIDING THROUGH LATE THIS AFTERNOON THROUGH
THIS EVENING...SOME ENHANCEMENT IS EXPECTED. WILL KEEP SNOW AMOUNTS
AROUND 2IN OR LESS ACROSS THE W THIRD OF THE CWA.
ONE CONCERN FOR THE EVENING PERIOD WILL BE THE POTENTIAL OF A MESO
LOW SETTING UP OVER S CENTRAL LAKE SUPERIOR AFTER 03Z...KEEPING A
BAND OF MORE MODERATE SNOW OVER CENTRAL/E MARQUETTE COUNTY
AND W ALGER COUNTY. THE NAM AND REGIONAL WRF HIGHLIGHT THE
POTENTIAL. HAVE EXPANDED SNOW FARTHER W TO ACCOUNT FOR THIS...AS
WELL AS KEPT THE WINDS UP OVER S CENTRAL LAKE SUPERIOR A BIT LONGER
/WHICH SEEMS TO HAVE BEEN ALREADY ACCOUNTED FOR/. ENHANCED BY THE
WINDS GUSTING 25-35KTS...VISIBILITY RESTRICTIONS WILL BE A CONCERN
FOR THOSE TRAVELING ON M-28. EVEN WITHOUT ANY LAKE ENHANCEMENT
BLOWING AND DRIFTING SNOW COULD BE AN ISSUE...DEPENDING ON HOW SOLID
SNOW BANKS ON THE SIDE OF THE ROAD HAVE BECOME AND HOW MUCH SNOW HAS
BEEN ABLE TO ACCUMULATE ON THE ICE ALONG LAKE SUPERIOR.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 411 AM EST THU JAN 29 2015
FCST FOCUS IN THE MEDIUM AND EXTENDED RANGE WL BE ON THE IMPACT OF
SEVERAL CLIPPER TYPE SHRTWVS THAT ARE FCST TO MOVE THRU A MEAN UPR
TROF IN ERN NAMERICA. UNDER THE PERSISTENT NW FLOW ALOFT...EXPECT
BLO TO WELL BLO NORMAL TEMPS TO DOMINATE DURING THIS TIME WITH A
STEADY FEED OF CNDN AIR. WITH THE COLD AIR SURGES...LES WL BE AN
OBVIOUS CONCERN.
FRI...SFC HI PRES IS FCST TO SHIFT FM OVER MN TOWARD THE OH RIVER
VALLEY BE 00Z SAT. AS NW WINDS IN THE MRNG BACK TO THE W AND THEN
THE SW LATE...LINGERING LES OVER THE W WL BECOME CONFINED TO OVER
THE KEWEENAW AND END OVER THE E EXCEPT NEAR THE SHORE E OF GRAND
MARAIS TOWARD 00Z SAT. ALTHOUGH THE LK CLDS WL BE SHIFTING
OFFSHORE...MORE MID/HI CLDS IN ADVANCE OF ANOTHER SHRTWV MOVING SE
WITHIN THE NW FLOW ALF WL BE PUSHING INTO THE UPR LKS.
FRI NGT/SAT...SHRTWV EMBEDDED IN THE NW FLOW ALOFT WL BE MOVING INTO
NW MN AT 00Z SAT AND IS THEN FCST TO SLIDE SE THRU NCENTRAL WI BY
12Z SAT AND THEN ACROSS LOWER MI ON SAT. AT THE SAME TIME...ANOTHER
STRONGER SHRTWV WL BE MOVNG FM CENTRAL CANADA INTO FAR NW ONTARIO BY
12Z SAT BEFORE MOVING TO JUST S OF JAMES BAY BY 00Z SUN. UPR MI WL
BE IMPACTED MAINLY BY THE WEAKER SRN DISTURBANCE. ALTHOUGH A BAND OF
RELATIVELY WEAK QVECTOR CNVGC IS FCST TO SLIDE ACROSS UPR MI ON FRI
NGT INTO SAT MRNG ON THE CYC SIDE OF THIS SRN SHRTWV...ACCOMPANYING
ISENTROPIC ASCENT/MSTR INFLOW IS FCST TO BE RELATIVELY WEAK. SO WL
FCST ONLY CHC POPS OVER MOST OF THE CWA AND MAINLY BTWN 03Z SAT AND
15-18Z SAT...WHEN THE FORCING ACCOMPANYING THE SRN SHRTWV AND A COLD
FNT ATTENDANT TO THE NRN SHRTWV ARE FCST TO EXIT THE ERN CWA AND
GIVE WAY TO SOME VIGOROUS DEEP LYR QVECTOR DVGC. MAINTAINED SOME
LIKELY POPS OVER THE NRN TIER OF THE CWA CLOSE TO THE STRONGER NRN
SHRTWV AND WHERE SHARPER LLVL CNVGC WL ACCOMPANY THE SAT COLD FROPA.
THE COLDEST 00Z GFS/12Z ECMWF RUNS SHOW H85 TEMPS IN THE WAKE OF THE
SAT COLD FROPA PLUNGING AS LO AS -25C BY 00Z SUN...BUT QUICK
TRANSITION TO A MORE DIFFLUENT/ACYC H925 N FLOW AND INVRN BASE
FALLING TO H85-875 WL TEND TO LIMIT LES INTENSITY. RELATIVELY
MODERATE TEMPS INTO SAT MRNG WL FALL THRU THE AFTN AS THE COLDER AIR
SURGES INTO THE AREA IN THE STEADY N FLOW AHEAD OF ARCTIC HI PRES
BLDG SEWD IN SCENTRAL CANADA.
SAT NGT THRU SUN NGT...UPR MI WL REMAIN DOMINATED BY A COLD N
BACKING WNW LLVL FLOW OF ARCTIC AIR ASSOCIATED WITH ARCTIC HI PRES
MOVING FM OVER ALBERTA/SASKATCHEWAN AT 00Z SUN INTO THE UPR MS RIVER
VALLEY BY 12Z MON. EXPECT TEMPS TO RUN WELL BLO NORMAL AND LES TO
CONTINUE NEAR LK SUP WITH H85 TEMPS FCST TO REMAIN NOT FAR FM -22C
TO -25C. SAT NGT COULD BE PARTICULARLY CHILLY OVER THE E WITH THE N
H925 FLOW ALLOWING SOME DRAINAGE OF COLD AIR INTO THAT AREA OFF
ONTARIO. ALTHOUGH FCST ACYC NATURE OF THE H925 FLOW AND NEAR ABSENCE
OF THE DGZ ASSOCIATED WITH THE VERY LO H85 TEMPS WL LIMIT LES
AMOUNTS...SOME OF THE MODELS HINT THERE MAY BE SOME ENHANCED CNVGC
ALONG A LK INDUCED TROF STRETCHING FM THE KEWEENAW TOWARD WHITEFISH
PT THAT WL INTENSIFY AS THE LARGER PRES GRADIENT RELAXES AND A
SHRTWV EMBEDDED IN THE NW FLOW APRCHS ON SUN/SUN NGT. RAISED POPS
WELL ABOVE THE CONSENSUS TO LIKELY ALONG THIS AXIS.
MON...LES ALONG THE LK INDUCED TROF WL BEGIN TO DIMINISH/SHIFT OUT
INTO LK SUP WITH THE APRCH OF A SFC RDG AXIS EXTENDING N FM THE HI
CENTER SHIFTING TOWARD THE OH VALLEY AND THE ASSOCIATED BACKING LLVL
FLOW. BUT THE MORE W WIND COMPONENT WL MEAN LESS LK MODERATION AND
PERSISTENT WELL BLO NORMAL SFC TEMPS EVEN AS THE H85 TEMPS MODERATE
A BIT FASTER.
TUE/WED...THE LONGER RANGE GUIDANCE HINTS ANOTHER CLIPPER TYPE
DISTURBANCE WL PASS THRU THE UPR LKS ON TUE...WITH H85 TEMPS
REBOUNDING TO NEAR -15C IN THE WAA BTWN THIS FEATURE AND HI PRES
MOVING INTO THE MID ATLANTIC. BUT ANOTHER ARCTIC SURGE LOOKS TO
FOLLOW ON WED AS THE SHRTWV PASSAGE REAMPLIFIES THE ERN TROF AND THE
NW FLOW IN ADVANCE OF THE NEXT CNDN HI SINKING INTO THE NRN PLAINS
ADVECTS H85 TEMPS AS LO AS -25 TO -28C INTO THE UPR LKS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 725 AM EST THU JAN 29 2015
GUSTY N-NNW WINDS ARE BEGINNING TO TAKE HOLD AT IWD AND
CMX...AND WILL PUSH INTO SAW OVER THE NEXT 2 HOURS. MUCH DRIER AIR
WORKING IN WILL BE WORKING AGAINST THE STRONG UPSLOPE WINDS
TODAY...AND WITH COLDER AIR PUSHING ACROSS LAKE SUPERIOR...EXPECT
NEARLY STEADY STATE CONDITIONS WITH MVFR CEILINGS. IFR CONDITIONS
MAY BE POSSIBLE IN SNOW AND BLOWING SNOW LATER THIS AFTERNOON AND
THIS EVENING AS AN UPPER LEVEL DISTURBANCE ENHANCES SNOW SHOWERS
BRIEFLY. OTHERWISE...LOOK FOR SLOWLY IMPROVING CONDITIONS TOWARDS
DAYBREAK FRIDAY AS WINDS RELAX TO AROUND 10KS OR LESS MORE OUT OF THE
NW AND LOW LEVEL MOISTURE DIMINISHES.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 AM EST THU JAN 29 2015
LOW PRESSURE SYSTEM NEAR N LAKE SUPERIOR THIS MORNING WILL MOVE INTO
QUEBEC THIS AFTERNOON WHILE ANOTHER LOW NEAR CHICAGO SHIFTS EAST
INTO NEW ENGLAND ON FRIDAY MORNING. MEANWHILE...A HIGH OVER S
CENTRAL CANADA WILL MOVE SE INTO MN ON FRIDAY. IN BETWEEN THE
EXITING LOW AND NEARING HIGH...STRONG N-NNW GALES GUSTING 35 TO
AROUND 40KTS WILL DEVELOP THIS AFTERNOON OVER MAINLY CENTRAL AND E
LAKE SUPERIOR. LOOK FOR WINDS TO SLOWLY DIMINISH LATE THIS EVENING
AND OVERNIGHT...WITH GUSTS REMAINING 25-30KTS THROUGH DAYBREAK
FRIDAY. GIVEN THE STRONG WINDS...AND COLDER AIR SURGING IN...HEAVY
FREEZING SPRAY WILL BE POSSIBLE OVER THIS SAME AREA INTO EARLY
FRIDAY MORNING. WINDS WILL THEN QUICKLY DIMINISH AND REMAIN LESS
THAN 30KTS THROUGH FRIDAY NIGHT.
AS THIS HIGH DRIFTS INTO THE OH RIVER VALLEY ON SATURDAY...A TROUGH
WILL SLIDE ACROSS THE UPPER GREAT LAKES. A FEW N TO NW GUSTS OF 30
TO NEAR 35KTS WILL BE POSSIBLE SATURDAY AFTERNOON AND EVENING.
EXPECT HIGH PRESSURE OVER CENTRAL CANADA ON SATURDAY TO MOVE SE INTO
THE N PLAINS ON SUNDAY...AND THE MID MS RIVER VALLEY ON MONDAY.
WINDS SHOULD DIMINISH FOR A TIME SUN BEFORE INCREASING AGAIN MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 7 AM
EST FRIDAY FOR LSZ264-266-267.
GALE WARNING FROM 1 PM THIS AFTERNOON TO 4 AM EST FRIDAY FOR
LSZ267.
GALE WARNING UNTIL 4 AM EST FRIDAY FOR LSZ265-266.
GALE WARNING UNTIL 1 AM EST FRIDAY FOR LSZ263-264.
HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 1 AM
EST FRIDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KF
LONG TERM...KC
AVIATION...KF
MARINE...KF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
546 AM CST THU JAN 29 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM CST THU JAN 29 2015
SHORT TERM CONCERNS ARE HEADLINES EARLY THIS MORNING. THEN OVERALL
IMPROVING TREND AND TURNING COLDER.
RADAR CONTINUES TO SHOW SOME LIGHT INTENSITY ECHOES MOVING ACROSS
EAST CENTRAL MN. WATER VAPOR IMAGERY SHOWING SECONDARY TROUGH
MOVING INTO WESTERN MN NOW. THE TREND ON THE RAP HAS BEEN
GENERATING SOME LIGHT QPF INTO SOUTH CENTRAL MN THROUGH ABOUT 14Z.
NOTHING TOO DRAMATIC ON RADAR...ALTHOUGH SURFACE OBS CONTINUE TO
SHOW SOME VISIBILITY REDUCTION IN BR AND OCCASIONALLY SOME -SN OR UP.
WILL CONTINUE THE FREEZING RAIN ADVISORY THROUGH 12Z. WILL WORD
THAT PRECIPITATION SHOULD BE ENDING THIS MORNING.
THE OTHER CONCERN IS THE WIND ADV TO THE SOUTHWEST. WINDS HAVE BEEN
INCREASING TO THE WEST OVERNIGHT AS THE PRESSURE GRADIENT INCREASES
WITH THE COLD FRONT MOVING THROUGH. THIS SHOULD CONTINUE THROUGH AT
LEAST MID MORNING AS THE GREATEST PRESSURE RISE MOVES THROUGH THE
AREA. HAVE INCLUDED A COUPLE MORE COUNTIES IN WEST CENTRAL MN AS
WELL.
WINDS ARE EXPECTED TO DIMINISH OVERALL AFTER 18Z AND BECOME LIGHT
INTO TONIGHT. CLOUDS WILL THIS AS WELL WITH TEMPERATURES DROPPING
THROUGH THE SINGLE DIGITS AND TEENS FOR LOWS TONIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 349 AM CST THU JAN 29 2015
WEST/NORTHWEST FLOW WILL PREVAIL THROUGH THE MAJORITY OF THE LONG
TERM FORECAST PERIOD...WITH ONLY MINOR/FLEETING CHANCES FOR
PRECIPITATION FORESEEN INTO EARLY NEXT WEEK.
FRIDAY WILL BE A TALE OF TWO STORIES WITHIN THE FORECAST AREA...AS
THE DEPARTING SURFACE HIGH YIELDS TEMPS AROUND 5 TO 10 DEGREES
BELOW NORMAL IN THE EAST OVER WISCONSIN...AND LOW LEVEL WARM AIR
ADVECTION OVER THE WEST BRINGS HIGHS FROM 5 TO 10 DEGREES ABOVE
NORMAL TO WEST CENTRAL AND SOUTHWESTERN MINNESOTA. EXPECT HIGH
TEMPS TO RANGE FROM 15 TO 20 DEGREES OVER WEST CENTRAL WI...TO THE
LOWER 30S ALONG THE MN RIVER VALLEY.
ON SATURDAY...THE GFS AND ECMWF MODELS ARE STICKING TO THEIR GUNS
IN PROGGING THE BULK OF THE PRECIPITATION TO PASS SOUTH OF THE
FORECAST AREA...AS AN INCOMING ARCTIC HIGH SUPPRESSES THE SYSTEM
LIFTING OUT OF THE SOUTHWESTERN CONUS. COULD SEE A LIGHT ROUND OF
SNOWFALL WITH INCH OR SO ACCUMULATIONS ON SATURDAY NIGHT AHEAD OF
THE APPROACHING HIGH...BUT THE MAIN /SOUTHERN STREAM/ SYSTEM
SHOULD STAY WELL SOUTH OF THE AREA.
THE ARCTIC HIGH WILL INEVITABLY BE ACCOMPANIED BY A NOTABLE
REDUCTION IN TEMPERATURES...WITH HIGHS FROM 5 TO 15 DEGREES ON
SUNDAY...AND SUB-ZERO LOWS OCCURRING NEARLY AREA-WIDE ON SUNDAY
NIGHT. ASSOCIATED WINDS WILL BE RATHER LIGHT...SO DO NOT CURRENTLY
EXPECT WIND CHILLS TO DIP LOWER THAN -15 TO -20 ON SUNDAY NIGHT
AND MONDAY MORNING.
AS THE HIGH SLIPS OFF TO THE SOUTHEAST...TEMPERATURES WILL
GRADUALLY MODERATE BACK TO NORMAL AS A SURFACE TROUGH APPROACHES
FROM THE NORTHERN ROCKIES. THIS FEATURE MAY BRING A LIGHT ROUND OF
SNOW ON MONDAY NIGHT INTO TUESDAY MORNING...DURING WHICH 20-30
POPS HAVE BEEN INCLUDED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 540 AM CST THU JAN 29 2015
FREEZING DRIZZLE THREAT ENDING TO THE SOUTHEAST. TRANSITIONED TO
SNOW SHOWERS/FLURRIES UPSTREAM. THIS SHOULD COME TO AN END IN AN
THROUGH MID MORNING. THEN MVFR CIGS SHOULD GRADUALLY BREAK FROM
WEST TO EAST THROUGH THE LATE AFTERNOON/EVENING. EXPECT VFR
CONDITIONS THEN INTO THE LATE EVENING WITH SOME MID/HIGH LEVEL
CLOUDS RETURNING LATE. STRONG NW WINDS GUSTING 35-40KTS OUT IN
WESTERN AREAS THIS MORNING...DIMINISHING FROM WEST TO EAST INTO
EARLY EVENING.
KMSP...FREEZING DRIZZLE THREAT HAS ENDED. SOME FLURRIES POSSIBLE
FOR AN HOUR OR TWO. MVFR CONDITIONS EXPECTED THROUGH ABOUT 22Z.
THEN BECOMING VFR THROUGH THE REST OF THE PERIOD. SOME MID HIGH
LEVEL CLOUDS MOVE IN LATE TONIGHT BUT WILL REMAIN VFR. STRONG NW
WINDS GUSTING AROUND 25KTS THROUGH THE DAY...DIMINISHING THIS
EVENING AND BECOMING LIGHT SOUTHEAST FRIDAY MORNING.
/OUTLOOK FOR KMSP/
FRI AFTERNOON...VFR. WIND S 5 KT.
SAT...MAINLY VFR...CHC MVFR CIGS/-SN SAT NIGHT. WIND N 5-10 KT.
SUN...MAINLY VFR...CHC MVFR CIGS EARLY. WIND N 10 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FREEZING RAIN ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR
MNZ051>053-059>063-066>070-075>078-083>085.
WIND ADVISORY UNTIL 9 AM CST THIS MORNING FOR MNZ047-048-054>057-
064-065-073>075-082>084-091>093.
WI...FREEZING RAIN ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR
WIZ014>016-023>028.
&&
$$
SHORT TERM...DWE
LONG TERM...LS
AVIATION...DWE
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
529 AM CST THU JAN 29 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 359 AM CST THU JAN 29 2015
SFC OBS INDICATE CEILINGS ARE RISING ACROSS
NCNTL NEB. THE CLOUDS ARE ASSOCIATED WITH COLD AIR ADVECTION WHICH
THE NAM AND RAP MODELS SHOW WEAKENING THIS MORNING 15Z-18Z. THUS WE
SHOULD SEE A CONTINUED EROSION OF THE CLOUD COVER WITH MOSTLY SUNNY
SKIES FROM 18Z ONWARD.
THE MODEL CONSENSUS SUGGESTS HIGHS IN THE 40S TODAY. THE TEMPERATURE
FORECAST IS CLOSE TO RAP MODEL WHICH GENERALLY WORKS WELL IN CLEAR
SKY CONDITIONS.
TONIGHT...HIGH PRESSURE WILL MOVE OFF SLOWLY EAST WITH SOUTH WINDS
DEVELOPING ACROSS THE PANHANDLE FROM 03Z ONWARD AND SPREADING SLOWLY
EAST OVERNIGHT. THE COLDEST READINGS SHOULD OCCUR ALONG AND EAST OF
HIGHWAY 83 WHERE WINDS WILL REMAIN LIGHT AND VARIABLE MOST OF THE
NIGHT.
WINDS TODAY SHOULD CONTINUE TO DECREASE FROM WEST TO EAST. THE RAP
MODEL INDICATES NORTH WINDS AT JUST 10 TO 15 MPH BY 3 PM THIS AFTN
AS PACIFIC HIGH PRESSURE BUILDS INTO WRN NEB.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 359 AM CST THU JAN 29 2015
A WEAKENING UPPER LEVEL RIDGE WILL TRANSLATE EAST ACROSS THE CENTRAL
PORTIONS OF THE UNITED STATES FRIDAY. MILD PACIFIC AIR WILL
ACCOMPANY THE RIDGING...WITH H850MB TEMPERATURES RANGING FROM
2C TO 4C ACROSS THE AREA. THE DAY WILL START SUNNY...BUT SOME
INCREASE IN HIGH CLOUDINESS EXPECTED BY LATER IN THE DAY AS SUB
TROPICAL MOISTURE BEGINS TO APPROACH THE AREA FROM THE SOUTHWEST.
WITH THE MILD AIR IN PLACE AND EXPECTED SUN...WILL RAISE HIGHS A FEW
DEGREES INTO THE MID 40S TO LOWER 50S.
STILL LOOKS INTERESTING FRIDAY NIGHT THROUGH SATURDAY NIGHT. A
LARGE PLUMB OF SUB TROPICAL MOISTURE...ORIGINATING OFF THE WEST
COAST OF MEXICO...WILL BE DRAWN NORTHWARD INTO THE SOUTHERN AND
POSSIBLY CENTRAL PLAINS AHEAD OF AN UPPER LEVEL TROUGH THAT WILL
MOVE INTO THE DESERT SOUTHWEST/WESTERN CONUS BY FRIDAY EVENING. AT
THE SAME TIME...A NORTHERN STREAM SHORTWAVE WILL BE MOVING INTO
BRITISH COLUMBIA FROM THE GULF OF ALASKA. MODELS HAVE BEEN
STRUGGLING WITH THE NORTHERN STREAM FEATURE...WITH SOME MODEL RUNS
STRONGER AND MORE AMPLIFIED WITH THE SHORTWAVE...AND OTHERS WEAKER
AND MORE SHEARED. THE LATEST 29/00Z RUN OF THE ECMWF SUPPORTS A
WEAKER...FASTER AND MORE SHEARED SHORTWAVE...WITH THE GFS A BIT
SLOWER AND MORE AMPLIFIED...AND THE NAM BEING THE MOST AMPLIFIED AND
SLOWEST OF ALL. HOW THE NORTHERN STREAM SYSTEM INTERACTS WITH THE
SUB TROPICAL MOISTURE REMAINS IN QUESTION. A SLOWER MORE AMPLIFIED
SCENARIO WOULD PULL MOISTURE FARTHER NORTH THOUGH THE FORECAST
AREA...WHILE A FASTER MORE SHEARED SCENARIO WOULD TEND TO SHUNT MUCH
OF THE SUB TROPICAL MOISTURE OFF TO THE EAST. THE SLOWER MORE
AMPLIFIED NAM WOULD FAVOR BETTER CHANCES FOR SNOW...WHILE THE GFS
AND ESPECIALLY THE ECMWF WOULD NOT. DUE TO THE WOBBLING OF THE
MODELS IN REGARDS TO THE NORTHERN STREAM...WILL ONLY MAKE SLIGHT
ADJUSTMENTS TO THE CURRENT POP FORECAST. WILL MAINTAIN THE LOW
CHANCE POPS ACROSS CENTRAL AND PORTIONS OF NORTH CENTRAL
NEBRASKA...WITH A DECREASE TO JUST SLIGHT CHANCES FARTHER WEST.
NORTHERN STREAM ENERGY IS QUITE DIFFICULT TO FORECAST...AND EXPECT
THAT MODELS WILL CONTINUE TO WOBBLE SOME UNTIL THE FEATURE IS
ONSHORE FRIDAY.
AS THE NORTHERN STREAM ENERGY PASSES...EXPECT A BATCH OF ARCTIC AIR
TO PUSH SOUTH INTO THE CENTRAL AND NORTHERN PLAINS IN IT/S WAKE
SUNDAY. UPPER FLOW QUICKLY BECOMES MORE ZONAL MONDAY...WITH PACIFIC
AIR SPREADING BACK INTO THE REGION FROM THE WEST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 529 AM CST THU JAN 29 2015
THE AREA OF MVFR CIGS GENERALLY EAST OF HIGHWAY 83 IS EXPECTED TO
DRIFT EAST THIS MORNING AND THEN MIX OUT TO VFR CIGS BEFORE
COMPLETELY ERODING AROUND 18Z. VFR IS EXPECTED ALL AREAS
THEREAFTER THIS AFTN AND TONIGHT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
515 AM CST THU JAN 29 2015
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 312 AM CST THU JAN 29 2015
EXTENSIVE LOW CLOUD LAYER HAD OVERSPREAD EASTERN NEBRASKA AND
SOUTHWEST IOWA EARLY THIS MORNING. HRRR SUGGESTS CLOUDS WILL
LIKELY HANG TOUGH THROUGH THE MORNING BEFORE BREAKING UP FROM WEST
TO EAST DURING THE EARLY AFTERNOON. GUSTY NORTHWEST WINDS ALSO
EXPECTED TO CONTINUE INTO THE MORNING ALTHOUGH LATEST TREND
APPEARS TO BE A DECREASE FROM NORTH TO SOUTH THROUGH 12Z. WILL
ADD REMAINING SOUTHERN COUNTIES TO ADVISORY THROUGH EXPIRATION AT
7 AM. HIGH PRESSURE RIDGE THEN SETTLES OVER THE AREA TONIGHT
BEFORE MOVING EAST ON FRIDAY.
NEXT FORECAST CONCERN DEVELOPS FRIDAY NIGHT AND SATURDAY AS A COLD
FRONT MOVES INTO THE AREA FROM THE NORTH WHILE LOW LEVEL WARM
ADVECTION MOVES IN FROM THE SOUTH IN ADVANCE OF CLOSED UPPER LOW
OVER THE SOUTHWEST PART OF THE COUNTRY. LATEST MODEL SOLUTIONS
INDICATE AN AREA OF LIGHT PRECIP SPREADING INTO THE SOUTH HALF OF
THE FORECAST AREA BY SATURDAY MORNING THEN LINGERS THROUGH
SATURDAY NIGHT.
AT THIS TIME IT APPEARS NORTHERN PARTS OF THE AREA SHOULD STAY DRY
FOR THE MOST PART. DRIER AIR COMING IN WITH NEXT BATCH OF COLD AIR
LOOKS TO LIMIT NORTHERN EXTENT OF PRECIP WITH A SHARP CUTOFF
ACROSS EAST CENTRAL NEBRASKA AND WEST CENTRAL IOWA. PRECIP LIKELY
TO START OFF AS LIQUID ALONG THE SOUTHEAST BORDER AREA LATE FRIDAY
NIGHT THEN TRANSITION TO LIGHT SNOW DURING THE DAY SATURDAY AS THE
COLD AIR DEEPENS BEHIND THE FRONT. SOME LIGHT SNOW ACCUMULATION IN
THE 1 TO 2 INCH RANGE POSSIBLE BY SUNDAY MORNING ACROSS SOUTHEAST
NEBRASKA INTO SOUTHWEST IOWA WITH UPPER BOUND NEAR SOUTHERN BORDER
OF NEBRASKA AND SOUTHWEST IOWA.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 312 AM CST THU JAN 29 2015
MUCH COLDER AIR MOVES IN ON SUNDAY AS THE SOUTHERN PLAINS WEATHER
SYSTEM MOVES EAST AND HIGH PRESSURE BUILDS INTO THE CENTRAL
PLAINS. COLDEST AIR HANGS AROUND THROUGH MONDAY BEFORE SOME
MODERATION RETURNS AS ANOTHER CLIPPER MOVES INTO THE REGION MONDAY
NIGHT. MORE COLD AIR FOLLOWS BEHIND THE CLIPPER FOR TUESDAY INTO
WEDNESDAY ALONG WITH ANOTHER POTENTIAL FOR LIGHT SNOW AS
BAROCLINIC ZONE DEVELOPS IN THE AREA.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 509 AM CST THU JAN 29 2015
MVFR CONDITIONS EARLY IN THE PERIOD...BUT SCATTERING OUT TO VFR BY
18-20Z. VERY STRONG NORTHWEST WINDS 22 TO 32 KNOTS EARLY...WITH
GUSTS DIMINISHING BY 20-23Z...THEN BECOMING LIGHT AND VARIABLE BY
00-02Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 7 AM CST THIS MORNING FOR NEZ015-030>034-
042>045-050>053-065>068-078-088>093.
WIND ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR NEZ011-012-
016>018.
IA...WIND ADVISORY UNTIL 7 AM CST THIS MORNING FOR IAZ043-055-056-069-
079-080-090-091.
&&
$$
SHORT TERM...FOBERT
LONG TERM...FOBERT
AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1027 AM EST THU JAN 29 2015
.SYNOPSIS...HIGH PRESSURE WILL MOVE OFFSHORE TODAY AND GIVE WAY
TO A COLD FRONT THAT WILL CROSS THE AREA TONIGHT INTO FRIDAY
MORNING. HIGH PRESSURE WILL BUILD IN FROM THE WEST ON FRIDAY...WHICH
WILL HELP TO KEEP CONDITIONS DRY THROUGH MUCH OF THE WEEKEND.
&&
.NEAR TERM /THROUGH FRIDAY NIGHT/...
AS OF 1027 AM THURSDAY...
15Z ANALYSIS SHOWS HIGH PRESSURE CONTINUING TO PUSH EAST OF US WHILE
THE COLD FRONT OVER THE OHIO VALLEY MOVES EAST. CLOUDS WILL
CONTINUE TO INCREASE ACROSS OUR AREA AS THIS PATTERN EVOLVES AND THE
COLD FRONT APPROACHES. MODELS STILL SUGGESTING A FEW RAIN SPRINKLES
OR LIGHT RAIN SHOWERS ARE POSSIBLE LATER TODAY IN ADVANCE OF THE
FRONT...WITH THE BEST CHANCES ACROSS OUR NORTHERN AND WESTERN ZONES.
LATEST HRRR SUGGESTS THE SLIGHT CHANCE POPS THIS AFTERNOON MAY NEED
TO BE EXPANDED A LITTER FURTHER EASTWARD ACROSS OUR AREA...BUT
EITHER WAY...ANY RAIN THAT OCCURS WILL BE VERY LIGHT WITH LOW
IMPACTS. OTHERWISE...NO SIGNIF CHANGES WITH THE MORNING UPDATE.
PREV DISCUSSION AS OF 230 AM...OPTIMAL RADIATIONAL COOLING FOR THE
NEXT COUPLE OF HOURS WHILE HIGH PRESSURE OVERHEAD CALMS WINDS AND
SKIES REMAIN CLEAR. THIS WONT LAST FOR TOO LONG HOWEVER AS HIGH
CLOUDS ARE BEGINNING TO MOVE IN FROM THE WEST ASSOCIATED WITH A
FRONTAL SYSTEM WITH PARENT MOVING INTO THE CHICAGO AREA AT THIS
TIME. THE ATTENDANT COLD FRONT...WHICH IS WEAK IS PROGGED TO CROSS
CENTRAL NC LATER TONIGHT AND INTO FRIDAY MORNING. UNTIL
THEN...SOUTHERLY RETURN FLOW WILL PICK UP ON THE BACK SIDE OF THE
SURFACE HIGH AFTER SUNRISE WITH SOME GUSTING AROUND 15 KTS
POSSIBLE...ESPECIALLY IN THE WEST WHICH IS FURTHER AWAY FROM THE
CENTER OF THE HIGH. USING DRY ADIABATIC METHODS OR LOW LEVEL
THICKNESSES SUGGEST TEMPERATURES IN THE MID TO UPPER 50S BUT WITH
THE INCREASING CLOUD COVER...ESPECIALLY DURING PEAK HEATING THESE
NUMBERS WILL BE CUT BACK TO THE UPPER 40S TO MID 50S. CANT RULE OUT
SOME HIGHER TEMPS IN THE SOUTHEAST...WHERE THE EFFECTS OF THE
APPROACHING SYSTEM WILL BE MOST DELAYED.
AS FAR AS PRECIPITATION CHANCES ARE CONCERNED WITH THE ACTUAL
FRONT...CONDITIONS ARE DRY BUT THE LATEST VERSION OF THE MODELS IS
NOT QUITE AS DRY AS YESTERDAY WITH PW VALUES INCREASING TO NEAR 0.7
INCHES AS OPPOSED TO 0.5 YESTERDAY. A FIRST LOOK AT HIGH RESOLUTION
CONVECTIVE MODELS ALSO SHOWS SOME VERY LIGHT PRECIPITATION IN THE
NORTHWEST PIEDMONT JUST AFTER 21Z AND FADING OUT AS IT HEADS
EASTWARD BEFORE PICKING UP AGAIN OFF THE COAST. FORECAST SOUNDINGS
SHOW A SIMILAR STORY WITH THE BEST SATURATION IN THE TRIAD WITH LESS
LIKELY CHANCES FOR RAIN SOUTH AND EAST. DESPITE BETTER CHANCES IN
THE TRIAD...SATURATION IN THE MODEL SOUNDINGS IS BRIEF AND CONFINED
TO THE 850-700 MB RANGE WITH A LOT OF DRY AIR
UNDERNEATH...SUGGESTIVE OF SPRINKLES OR VIRGA PERHAPS IF MOISTURE
CANT REACH THE SURFACE. THE RESULT IS STILL VERY INCONSEQUENTIAL AS
QPF AMOUNTS WOULD BE A COUPLE OF HUNDREDTHS OF AN INCH AT THE VERY
BEST BUT MORE LIKELY TRACE AMOUNTS OR NOTHING. BETTER UPPER LEVEL
DYNAMICS COME IN AFTER 00Z FRIDAY BUT THE SYSTEM JUST LOOKS TO DRY
TO SUSTAIN ANYTHING AT THAT TIME.
AFTER FRONTAL PASSAGE AROUND 6Z FRIDAY...WINDS WILL SHIFT BACK TO
NORTHWESTERLY AND COLD AIR ADVECTION WILL ONCE AGAIN ENSUE.
LINGERING CLOUD COVER BEHIND THE FRONT WILL KEEP LOWS WARMER...IN
THE LOW TO UPPER 30S NW TO SE. AS DRY AIR WORKS IN BEHIND THE
FRONT...CLOUDS MAY CLEAR OUT FOR THE LATE MORNING PERIOD...BUT THEN
WRAP AROUND MOISTURE ON THE BACK SIDE OF THE EXITING SYSTEM WILL
MOVE IN FROM THE NORTH AND CUT DOWN ON INSOLATION DURING PEAK
HEATING. THIS MAY CAUSE A TEMPERATURE GRADIENT FROM THE NORTH TO
SOUTH RESULTING IN HIGHS IN THE MID 40S TO LOW 50S. DRY CONDITIONS
ARE EXPECTED AND INCREASING WINDS OF 15-20 KTS SUSTAINED WITH GUSTS
OF UP TO 25 KTS COULD CAUSE SOME FIRE WEATHER CONCERNS ON FRIDAY
AFTERNOON. AT THIS TIME MIN RH VALUES WILL HOVER AROUND 30%. WINDS
WILL DIE OFF AFTER SUNSET AND COUPLED WITH CLEAR SKIES WILL CAUSE
OPTIMAL RADIATIONAL COOLING RESULTING IN LOW TEMPERATURES NEAR 20
DEGREES FRIDAY NIGHT INTO SATURDAY MORNING.
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...
SURFACE HIGH PRESSURE OVER THE TN VALLEY WILL BUILD SOUTHWARD ACROSS
THE AREA ON SATURDAY...SHIFTING SOUTH AND OFF THE SOUTHEAST COAST
SATURDAY NIGHT. ALOFT...WEAK SOUTHERN STREAM IMPULSES EMBEDDED IN
INCREASING ZONAL FLOW ALOFT LATE SATURDAY/SATURDAY NIGHT WILL YIELD
THICKENING CIRRUS LAYER THROUGH THE DAY WITH MOSTLY CLOUDY SKIES BY
SATURDAY NIGHT. HIGHS WILL REMAIN BELOW NORMAL...RANGING FROM LOWER
40S NORTH TO MID/UPPER 40S SOUTH. LOWS SATURDAY NIGHT IN THE LOWER
TO MID 30S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...
SUNDAY THROUGH MONDAY: MINOR MID-LEVEL IMPULSES EMANATING FROM THE
UPPER TROUGH/CLOSED LOW OVER THE SOUTHWEST US...WILL
INTERACT....POTENTIALLY PHASE WITH NORTHERN STREAM ENERGY DIVING
SEWD WITHIN THE BROADENING CONUS TROUGH. ASSOCIATED CYCLOGENESIS
WILL TRACK EASTWARD ACROSS THE LOWER MS VALLEY/MID-SOUTH ON
SUNDAY...CROSSING THE SOUTHERN APPALACHIANS SUNDAY EVENING AND THEN
OFF THE CAROLINA COAST BY MIDDAY MONDAY. DESPIT MODEL DIFFERENCES
IN THE AMPLITUDE OF THE NORTHERN STREAM TROUGH...TIMING OF THE
BETTER RAIN CHANCES INTO THE AREA ARE SIMILAR...WITH RAIN CHANCES
QUICKLY RAMPING UP LATE SUNDAY AFTERNOON/EARLY EVENING...WITH
CATEGORICAL POPS SUNDAY NIGHT...CUTTING OFF FROM WEST TO EAST
MORNING MONDAY AS THE MID-LEVEL DRY SLOT SPREAD EAST. CURRENT
MODELS PROJECT A SOLID 0.50-1.0" ACROSS THE AREA...WITH SOME HIGHER
AMOUNTS POSSIBLE IF THE MORE AMPLIFIED--WETTER GFS VERIFIES. NO P-
TYPE CONCERNS. HIGHS BOTH DAYS IN THE 40S NORTH TO AROUND 50 SOUTH.
LOWS SUNDAY NIGHT IN THE MID TO UPPER 30S NORTH TO LOWER-MID 40S
SOUTH.
MONDAY NIGHT THROUGH WEDNESDAY: CONTINENTAL POLAR HIGH PRESSURE WILL
BUILD INTO THE AREA MONDAY NIGHT AND INTO TUESDAY IN THE WAKE OF THE
UPPER LEVEL TROUGH LIFTING OUT OF THE AREA. IF PROJECTED LOW-LEVEL
THICKNESSES VERIFY...STRONG CAA MONDAY NIGHT WILL SUPPORT LOWS
TUESDAY MORNING IN THE TEENS ACROSS MUCH OF THE AREA...WITH HIGHS
TUESDAY AFTERNOON STRUGGLING TO WARM INTO THE 40S.
MODEL SPREAD REMAINS HIGH WITH THE EASTWARD EJECTION OF THE
AFOREMENTIONED UPPER TROUGH/LOW OVER THE SOUTHWEST US. WHILE THE EC
SUGGEST THIS SYSTEM COULD BRING PRECIP CHANCES BACK INTO THE AREA
LATE TUESDAY NIGHT AND INTO WEDNESDAY...THE GFS AND CANADIAN
SUPPRESS THE SYSTEM WELL TO OUR SOUTH...MAINTAINING DRY CONDITIONS
THROUGH LATE WEEK. GIVEN THE UNCERTAINTY HAVE LIMITED POP TO
SLIGHT/SMALL CHANCE.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 645 AM THURSDAY...
24 HOUR TAF PERIOD: MEDIUM HIGH CONFIDENCE OF VFR CONDITIONS THROUGH
THE TAF PERIOD AS A DRY FRONTAL SYSTEM CROSSES THE AREA NEAR THE END
OF THE PERIOD. BANDS OF HIGH CLOUDS HAVE STARTED TO CROSS THE AREA
FROM THE WEST. LATER TODAY CLOUD COVER WILL INCREASE AS BROKEN
CEILINGS SET IN BY 18Z OR SO BUT THESE SHOULD BE IN THE 8-9 KFT
RANGE. THERE IS A SLIGHT CHANCE THAT CEILING COULD APPROACH MVFR
LEVELS AROUND 3Z BUT CONFIDENCE IN THIS IS LOW. AS FAR AS WINDS ARE
CONCERNED...EXPECT SOUTHERLY WINDS AT 5-10 KTS AFTER
DAYBREAK...GUSTING 15-20 KTS BEFORE RELAXING AGAIN AFTER SUNSET.
MAYBE A SPRINKLE OR LIGHT SHOWER IN THE TRIAD AHEAD OF THE FRONT
DURING THE 21-00Z TIMEFRAME.
LONG TERM: SUB-VFR CONDITIONS WILL BE POSSIBLE WITH A LOW PRESSURE
SYSTEM THAT WILL CROSS THE AREA LATE SUNDAY INTO MONDAY. VFR
CONDITIONS WILL PREVAIL FOR MUCH OF THE WEEK AFTER THAT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ELLIS
NEAR TERM... -/ELLIS
SHORT TERM...CBL
LONG TERM...CBL
AVIATION...ELLIS
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1017 AM EST THU JAN 29 2015
.SYNOPSIS...
A COLD FRONT WILL CROSS THE FORECAST AREA LATER TONIGHT WITH HIGH
PRESSURE BUILDING IN ITS WAKE ON FRIDAY. THE HIGH WILL LINGER OVER
THE REGION INTO SUNDAY BEFORE A MOIST LOW PRESSURE SYSTEM DEVELOPS
TO OUR SOUTHWEST AND BRINGS WIDESPREAD PRECIPITATION TO THE AREA
LATE SUNDAY AND MONDAY. ANOTHER CANADIAN HIGH MOVES BACK INTO THE
AREA LATE MONDAY AND LINGERS INTO MIDWEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
1000 EST THURSDAY UPDATE...LATEST SURROUNDING REGIONAL RADARS SHOW A
BAND OF LIGHT RETURNS WAS APPROACHING THE SOUTHERN APPALACHIANS FROM
THE TN VALLEY AS OF THIS MORNING. LATEST HRRR AND OTHER MESOSCALE
MODELS INDICATE THAT THIS BAND OF LIGHT PRECIP ASSOCIATED WITH AN
UPPER WAVE WILL MOVE EAST ACROSS THE NC MTN ZONES BETWEEN 16-18Z AND
ACROSS THE NC FOOTHILLS AND PORTIONS OF THE NORTHERN NC PIEDMONT
18-20Z. THEREFORE...POPS WERE UPDATED TO ACCOUNT FOR THIS THRU THIS
AFTERNOON. HOWEVER...PRECIP AMOUNTS APPEAR TO BE VERY LIGHT GIVEN
RELATIVELY DRY AIRMASS AND SHALLOW MOIST LAYER. NO WINTRY P-TYPE IS
EXPECTED THRU THIS AFTERNOON GIVEN GOOD WARMING TREND.
1115 UTC UPDATE...WINDS WERE UPDATED WITH A TWO TO ONE BLEND OF THE
NAM AND ADJMAV...FAVORING THE FORMER FOR STRINGER WINDS AND GUSTS IN
THE MOUNTAINS...BOTH AHEAD OF AND BEHIND THE APPROACHING COLD FRONT.
GUSTS STILL APPEAR TO REACH ADVISORY CRITERIA ONLY AT THE VERY
HIGHEST MOUNTAIN PEAKS LATE TONIGHT...SO NO ADVISORY IS PLANED AT
THIS TIME. SKY COVER WAS UPDATED FROM INFRARED SATELLITE IMAGERY.
AT 230 AM EST THURSDAY...AN UPPER RIDGE OF MODEST AMPLITUDE WILL
CROSS THE EASTERN SEABOARD THIS MORNING...WHILE AND UPPER TROUGH
MOVES FROM THE MS RIVER VALLEY TO THE OH AND TN RIVER VALLEYS. A
SHORTWAVE MOVING THROUGH THIS TROUGH WILL REACH THE CENTRAL
APPALACHIANS BY MIDDAY. THE RIDGE MOVES TO THE GULF STREAM THIS
AFTERNOON...WHILE THE SHORTWAVE MOVES OFF THE MID ATLANTIC COAST.
ANOTHER AND MORE ROBUST SHORTWAVE MOVING THROUGH THE TROUGH REACHES
THE CENTRAL AND SOUTHERN APPALACHIANS IN THE MIDDLE OF THURSDAY
NIGHT...MOVING EAST OF OUR AREA BY MORNING....WHILE THE TROUGH AXIS
REACHES THE EAST COAST.
A SURFACE RIDGE ALONG THE EAST COAST WILL MOVE OFFSHORE TODAY...
WHILE A COLD FRONT MOVES FROM THE MS RIVER VALLEY TO THE
APPALACHIANS. PRECIPITATION AHEAD OF THE FRONT WILL REACH THE
MOUNTAINS SOMETIME THIS MORNING...PERHAPS EARLY ENOUGH TO START AS
LIGHT SNOW. WITH WARMING...SNOW LEVELS RISE ABOVE THE MOUNTAIN TOPS
TODAY. NO APPRECIABLE SNOW ACCUMULATIONS ARE EXPECTED THIS MORNING.
THE MODELS DO NOT SHOW MUCH DEPTH TO THE MOIST LAYER EAST OF THE
BLUE RIDGE...AND PRECIPITATION CHANCES ARE QUITE LIMITED THERE.
FRONTAL PASSAGE TAKES PLACE OVERNIGHT...WITH DOWNSLOPE DRYING IN THE
LEE OF THE MOUNTAINS...AND MOIST NW FLOW INTO THE NC MOUNTAINS
BORDERING TN. SNOW LEVEL ARE EXPECTED TO FALL TO THE VALLEY FLOORS
THIS EVENING...WHILE COVERAGE RETREATS CLOSER TO THE TN BORDER.
RIGHT NOW IT APPEARS THAT SNOWFALL ACCUMULATIONS WILL RUN JUST UNDER
TWO INCHES OVERNIGHT...BUT ADVISORY CRITERIA WILL ONLY BE APPROACHED
ON THE VERY HIGHEST PEAKS...SO NO SNOW ADVISORY IS PLANNED. WINDS
WILL INCREASE IN THE TIGHT PRESSURE GRADIENT BEHIND THE FRONT...BUT
WIND ADVISORY CRITERIA WILL ONLY BE REACHED LATE TONIGHT ON PEAKS
OVER 5000 FT...SO NO WIND ADVISORY IS PLANNED AT THIS TIME.
HIGH TEMPERATURES WILL RUN NEAR NORMAL TODAY AS WARM ADVECTION UNDER
THE UPPER RIDGE IS OFFSET BY INCREASING CLOUD COVER...AND LOW
TEMPERATURES TONIGHT WILL RUN SLIGHTLY ABOVE NORMAL AS WINDS KEEP
THE ATMOSPHERE MIXED.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 115 AM THURSDAY...THE SHORT TERM BEGINS WITH AN INCREASING
SUBSIDENCE ZONE AND A WANING NWFS EVENT. DRY CP AIR WILL BEGIN
FILTERING INTO THE MTNS AND LIMIT THE ADDITIONAL SNOWFALL POTENTIAL.
LIKELY AROUND ANOTHER HALF TO ONE INCH THROUGH 21Z ACROSS WRN MTN
SPINE. GOOD H85 CAA ALONG WITH DEEP SUBSIDENCE WILL CONTINUE THE
STRONG WINDS/GUSTS ACROSS THE NC MTNS...WITH ADVISORY OR EVEN
WARNING CRITERIA BEING MET ABOVE 4000 FEET AS MODEL SOUNDINGS
INDICATE AN UPWARD TREND IN VELOCITIES ATOP THE MIXED LAYER THROUGH
MID AFTERNOON. WILL KEEP THE HWO MENTION FOR NOW AND THE DAY SHIFT
WILL LIKELY ISSUE THE NPW AS THE EVENT MOVES INTO THE 2ND PERIOD.
WINDS WILL RELAX SLOWLY THROUGH THE EVENING WITH A GOOD H85 TGRAD
EVENTUALLY LOOSENING AFT 00Z. MAX TEMPS WILL ABOUT 15 DEGREES BELOW
NORMAL MTN VALLEYS AND 3-5 DEGREES BELOW NORMAL NON/MTNS. HEIGHTS
BEGIN TO RISE FRI NIGHT AND FLAT RIDGING WILL BE IN PLACE BY SAT
AFTERNOON. THIS WILL ENABLE THE CP SFC HIGH TO CROSS THE FA
THROUGH THE PERIOD BECOMING SITUATED OFF THE CAROLINA COAST BY 12Z
SUN. THUS...SKIES WILL CLEAR AND TEMPS WILL REMAIN A FEW DEGREES
BELOW NORMAL AS A LLVL THETA/E TROF MIXES IN.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 255 AM THURSDAY MORNING...THE MEDIUM RANGE FCST PICKS UP AT
12Z ON SUNDAY WITH RELATIVELY ZONAL UPPER FLOW OVER THE CAROLINAS
AND A DEEPENING UPPER TROF TO OUR WEST. OVER THE NEXT 24 TO 36
HRS...THE TROF AXIS IS EXPECTED TO PASS OVERHEAD WITH MORE ZONAL
FLOW IN ITS WAKE. DURING THIS PERIOD...A SOUTHERN STREAM H5 LOW
SPINS UP OVER THE BAJA PENINSULA AND GRADUALLY DRIFTS NE TOWARDS OUR
AREA. BY THE END OF THE MEDIUM RANGE...THIS LOW WILL LIKELY GET
ABSORBED BY ANOTHER DEEPENING UPPER TROF.
AT THE SFC...HIGH PRESSURE WILL BE MOVING OFF THE SE COAST EARLY
SUNDAY AS ANOTHER LOW SPINS UP TO OUR WSW OVER THE LOWER MISS RIVER
VALLEY. THE ASSOCIATED BROAD AREA OF DEEP LYR MOISTURE WILL SPREAD
OVER THE REGION THRU THE DAY WITH OVERCAST CONDITIONS AND LIKELY
POPS BY LATE SUN/EARLY MON FOR PRETTY MUCH ALL ZONES. THE GFS
REMAINS ABOUT 12 HRS FASTER WITH THE DEVELOPMENT OF THIS SYSTEM
COMPARED TO THE ECMWF AND CMC. IN THE LOWS WAKE...ANOTHER CANADIAN
HIGH PUSHES BACK INTO THE REGION FROM THE NW ON MON AND DRIES THINGS
OUT. THE CENTER OF THE HIGH WILL PASS OVER THE AREA ON TUES AND MOVE
OFFSHORE BY EARLY WED. BEYOND THIS POINT THE MODEL GUIDANCE REMAINS
FAIRLY AMBIGUOUS WITH THE SYNOPTIC PATTERN. THE GFS BRINGS ANOTHER
REINFORCING CANADIAN HIGH DOWN OVER THE REGION ON THURS AND KEEPS
THINGS DRY. THE ECMWF TRIES TO SPIN UP ANOTHER MILLER A TYPE LOW
OVER THE NORTHERN GULF OF MEX ON WED AND MOVE THE SYSTEM ACROSS THE
CAROLINA COAST LATE WED/EARLY THURS AND AFTER THAT...IT DRIES THINGS
OUT LIKE THE GFS. THE PREVIOUS RUNS OF THE GFS HINTED MORE TOWARDS
THE MILLER A TYPE LOW DEVELOPING...SO THE CURRENT DRY SCENARIO LOOKS
QUESTIONABLE. AS FOR THE SENSIBLE FCST...I TRENDED A BIT COOLER FOR
THE MON/TUES PERIOD WITH LOWS EARLY TUES IN THE LOW TO MID 20S
ACROSS THE THE LOWER ELEVATIONS AND TEENS ACROSS THE HIGHER TERRAIN.
POP TRENDS WERE NOT CHANGED MUCH FOR THE FIRST HALF OF THE PERIOD
WITH BEST CHANCES LATE SUN THRU EARLY MON. FOR TUES/WED...I KEPT
POPS AT SLIGHT TO SOLID CHANCE DUE TO THE CONTINUING UNCERTAINTY
WITH THE GULF LOW.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
AT KCLT...VFR. A HIGH LEVEL CIRRUS CIG WILL SPREAD EAST OVER THE
FIELD THIS TODAY AHEAD OF A COLD FRONT. GUIDANCE HAS BACKED OFF
SUPPORT FOR A LOW VFR CIG THIS EVENING...INSTEAD PREFERRING A MID
LEVEL CIG...BEFORE EROSION LATE TONIGHT. SOME LOW CLOUDS WILL BE
CARRIED BENEATH HOWEVER. EVENING PRECIPITATION CHANCES STILL APPEAR
TOO LOW TO MENTION AT THIS TIME. S WINDS WILL COME UP THIS MORNING
VEERING SW THIS AFTERNOON...WITH GUSTS INCREASING. FRONTAL
PASSAGE AND NW WINDS WILL LATE TONIGHT.
ELSEWHERE...HIGH LEVEL CIRRUS CIGS WILL SET UP THIS MORNING IN
ADVANCE OF A COLD FRONT. CIGS FALL TO LOW VFR THIS EVENING AT KAVL
AND KAND...BUT GUIDANCE IS LESS CERTAIN AT KHKY...KGSP AND
KGMU...WHERE A MID LEVEL CIG IS INDICATED. AT THE LAST THREE
SITES...LOW CLOUDS WILL BE CARRIED BENEATH THE CIG. THE CIG FALLS TO
MVFR AT KAVL LATE TONIGHT IN MOIST NW FLOW BEHIND THE FRONT.
PRECIPITATION CHANCES AHEAD OF THE FRONT WILL TOO LOW TO
MENTION...ALTHOUGH KAVL WILL BE A CLOSE CALL. IF SOME SNOW CAN FALL
AT KAVL BEHIND THE FRONT LATE TONIGHT...VSBY MIGHT BE REDUCED...BUT
CONFIDENCE IS TOO LOW FOR A MENTION AT THIS TIME. S WINDS ARE
EXPECTED AFTER DAWN...THEN SW BY MIDDAY...WITH GUSTS INCREASING.
KAVL WINDS VEER NW THIS EVENING AS THE FRONT MOVES THROUGH...AND
FOOTHILLS WINDS FOLLOW SUIT LATE TONIGHT.
OUTLOOK...A PAIR OF CLIPPER SYSTEMS WILL BRING CHANCES FOR RAIN OR
SNOW SHOWERS TO THE NC MTNS FRI. MOST OF THESE SHOWERS WILL REMAIN
WEST AND NORTH OF KAVL...BUT BRIEF PERIODS OF RESTRICTIONS CANNOT BE
RULED OUT. OTHERWISE...MAINLY VFR CONDITIONS ARE EXPECTED ACROSS THE
AREA UNTIL MOISTURE BEGINS TO RETURN SUNDAY. DRYING IS EXPECTED ON
MONDAY.
CONFIDENCE TABLE...
15-21Z 21-03Z 03-09Z 09-12Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 92% MED 75%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...JAT/JOH
SHORT TERM...SBK
LONG TERM...JPT
AVIATION...JAT
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
410 PM CST THU JAN 29 2015
.SHORT TERM...
234 PM CST
THROUGH SATURDAY...
THE MAIN FOCUS DURING THIS PERIOD WILL BE WITH THE POTENTIAL FOR
SOME ACCUMULATING LAKE EFFECT SNOW ACROSS PORTIONS OF NORTHWESTERN
INDIANA TONIGHT INTO FRIDAY MORNING.
LOW PRESSURE NOW ACROSS THE EASTERN GREAT LAKES REGION...DROVE A
COLD FRONT ACROSS THE AREA THIS MORNING...AND HAS SINCE CONTINUED TO
PRODUCING GUSTY NORTHWEST WINDS ACROSS THE REGION THROUGH THE
AFTERNOON. WATER VAPOR IMAGERY THIS AFTERNOON INDICATES THE NEXT
SHORT WAVE DISTURBANCE NOW DIGGING SOUTHWARD OVER LAKE SUPERIOR.
THIS DISTURBANCE IS EXPECTED TO RACE SOUTHWARD ACROSS SOUTHERN LAKE
MICHIGAN THIS EVENING...AND AS IT DOES SO...IT COULD PRODUCE ENOUGH
LIFT TO SQUEEZE OUT A FEW FLURRIES...SO I HAVE ADDED THE MENTION TO
THE FORECAST THROUGH MUCH OF THE EVENING.
OTHERWISE...IT APPEARS THAT LAKE EFFECT SNOW SHOWERS WILL CONTINUE
TO DEVELOP OVER SOUTHERN LAKE MICHIGAN TONIGHT...AND AS THE BOUNDARY
LAYER FLOW OVER LAKE MICHIGAN BEGINS TO BACK NORTHERLY...IT APPEARS
THAT SOME BANDS OF LAKE EFFECT SNOW WILL BEGIN TO IMPACT PORTIONS OF
NORTHWESTERN INDIANA OVERNIGHT TONIGHT THROUGH FRIDAY MORNING. LAKE
INDUCED EQUILIBRIUM LEVELS ARE EXPECTED TO RESIDE AROUND 5,000
FEET...AND DUE TO THE COLD LOWER LEVEL ATMOSPHERE...THIS SHOULD BE
HIGH ENOUGH TO RESIDE WELL INTO THE DENDRITE GROWTH ZONE.
THEREFORE...SOME EFFICIENT SNOWFALL LOOKS TO RESULT IN SOME
ACCUMULATING POTENTIAL...ESPECIALLY ACROSS PORTIONS OF PORTER COUNTY
INDIANA IN MY AREA...WHERE SOME ISOLATED AREAS COULD GET A COUPLE
INCHES. THESE LAKE EFFECT SNOW SHOWERS WILL COME TO AN END BY EARLY
AFTERNOON AS THE FLOW BEGINS TO SHIFT WESTERLY IN RESPONSE TO A AN
AREA OF SURFACE HIGH SHIFTING SOUTHEASTWARD TOWARDS THE OHIO
VALLEY.
A BRIEF WARMING TREND LOOKS TO BE ON TAP LATE FRIDAY NIGHT AND
SATURDAY AS THIS HIGH SHIFTS OVER THE OHIO VALLEY...SETTING UP A
WEST SOUTHWESTERLY FLOW OF WARMER AIR OVER THE AREA. THIS SHOULD
ALLOW TEMPERATURES TO WARM WELL INTO THE 30S AREA-WIDE.
KJB
&&
.LONG TERM...
328 PM CST
SATURDAY NIGHT THROUGH THURSDAY...
THE MAIN FOCUS DURING THIS PERIOD WILL BE WITH THE INCREASING
POTENTIAL OF A DECENT ACCUMULATING SNOWFALL EVENT ACROSS AT LEAST
PORTIONS OF MY AREA SATURDAY EVENING THROUGH SUNDAY.
A COMPLEX WEATHER PATTERN WILL BE IN PLACE ACROSS THE CONUS DURING
THIS PERIOD. OVERALL...THE MAIN DISTURBANCE OF INTEREST IS NOW
EJECTING EAST-NORTHEASTWARD ACROSS THE NORTHEASTERN PACIFIC ALONG
THE EASTERN PERIPHERY OF AN UPPER LOW SOUTH OF THE ALEUTIANS. THIS
FEATURE WILL MOVING ONSHORE ACROSS THE BRITISH COLUMBIA COAST BY
FRIDAY MORNING...THEN IS EXPECTED TO DIG SOUTHEASTWARD ALONG THE
NORTHEASTERN PERIPHERY OF AN UPPER LEVEL RIDGE IN PLACE ACROSS THE
WESTERN CONUS. THE MAIN COMPLEXITIES WITH THIS SYSTEM...IS IF AND
HOW MUCH OF THE SOUTHERN STREAM ENERGY...EMANATING FROM THE
SOUTHWESTERN CONUS TROUGH...GETS TAPPED INTO BY THIS DIGGING SYSTEM.
MODEL GUIDANCE HAS FLIPPED FLOPPED A BIT OVER THE PAST COUPLE OF
RUNS ON HOW FAR NORTH THE ACCOMPANYING PRECIPITATION SHIELD WILL GET
SATURDAY NIGHT INTO SUNDAY. IT APPEARS ONE OF THE MAIN KEYS THAT
WILL PLAY A ROLE IN HOW FAR NORTH THE SNOWFALL ENDS UP GETTING
ACROSS ILLINOIS WILL BE THE TIMING OF COLDER AIRMASS/COLD FRONTAL
PASSAGE EXPECTED ON SATURDAY NIGHT. A MUCH COLDER AIRMASS IS
EXPECTED TO SPILL IN ACROSS THE NORTHERN CONUS AHEAD OF A STOUT 1044
MB HIGH BUILDING SOUTHWARD OUT OF SOUTHERN MANITOBA SATURDAY
NIGHT...AND THIS SHOULD SET UP A GOOD BAROCLINIC ZONE POTENTIALLY
RIGHT ACROSS THE HEART OF MY CWA SATURDAY NIGHT INTO SUNDAY. AT THE
SAME TIME...ISENTROPIC ASCENT AND MOISTURE TRANSPORT WILL RAMP UP TO
OUR SOUTHWEST IN ADVANCE OF THE APPROACHING DISTURBANCE. THIS SHOULD
RESULT IN A LARGE AREA OF SNOWFALL DEVELOPMENT IN THE COLD AIR ACROSS
MISSOURI AND WEST CENTRAL ILLINOIS BY SATURDAY AFTERNOON. IT APPEARS
THIS SNOWFALL WILL GRADUALLY DEVELOP NORTHWARD ACROSS ILLINOIS BY
SATURDAY EVENING...AND MAY END UP IMPACTING MOST OF MY AREA TO SOME
DEGREE OVERNIGHT SATURDAY AND INTO SUNDAY. IT APPEARS THAT A DECENT
BAND OF FRONTOGENESIS COULD SET UP SOMEWHERE NEAR THE I-80 CORRIDOR
INTO SUNDAY MORNING AS A DEFORMATION AXIS TRIES TO DEVELOP WITH THE
925-850 MB LAYER AHEAD OF THE APPROACHING COLD AIRMASS. THIS COULD
RESULT IN SOME AREAS OF HEAVIER SNOW. HOWEVER...CONFIDENCE ON WHERE
EXACTLY THIS ENHANCED MESOSCALE FORCING SETS UP IS LOW AT THIS
TIME...GIVEN THIS SYSTEM IS 60+ HOURS AWAY. IT DOES APPEAR THAT MOST
AREAS MAY SEE AT LEAST SOME LIGHT SNOW ACCUMULATIONS...BUT THE
POTENTIAL OF A FEW TO SEVERAL INCHES OF SNOW ACCUMULATION IS
CERTAINLY A POSSIBILITY.
THE OTHER FACTOR TO CONSIDER WITH THIS EVENT IS THE POTENTIAL FOR
LAKE ENHANCED SNOW SHOWERS LATER SUNDAY AND INTO SUNDAY NIGHT ACROSS
NORTHEASTERN ILLINOIS. AS THE COLDER AIRMASS BEGINS TO SPILL
SOUTHWARD OVER THE AREA ON SUNDAY...WINDS WILL BECOME NORTHEASTERLY
OFF OF LAKE MICHIGAN. THE COLDER AIRMASS...FEATURING 850 MB
TEMPERATURES IN THE TEENS BELOW ZERO CELSIUS...SHOULD ALSO PRODUCE
FAVORABLE THERMODYNAMICS IN THE LOWEST LEVELS OF THE ATMOSPHERE FOR
ENHANCED SNOW SHOWERS LATER SUNDAY AND SUNDAY NIGHT. MODEL SOUNDINGS
INDICATE INVERSION HEIGHTS REACHING UP AROUND 5-6,000 FEET...WHICH
SHOULD EXTEND WELL INTO THE DENDRITIC GROWTH ZONE. THEREFORE...WE CANT
RULE OUT THE POTENTIAL FOR SOME HEAVIER SNOW TOTALS ACROSS PORTIONS
OF NORTHEASTERN ILLINOIS. AT THIS TIME...I HAVE REMAINED A BIT
CONSERVATIVE ON SNOW AMOUNTS ACROSS NORTHERN ILLINOIS...MAINLY DUE
TO THE HIGH UNCERTAINTIES WITH THIS EVOLVING SYSTEM.
FOLLOWING THIS SYSTEM...IT APPEARS THE REGION WILL REMAIN IN AND
ACTIVE WEST/NORTHWESTERLY FLOW PATTERN. THIS COULD SUPPORT A FEW
ADDITIONAL CLIPPER TYPE SYSTEMS WITH SNOW CHANCES AND REINFORCING
SHOTS OF COLD AIR THROUGH THE EXTENDED PERIOD. OVERALL...IT APPEARS
THAT WE WILL REMAIN BELOW TO WELL BELOW AVERAGE FOR TEMPERATURES
NEXT WEEK. A PERIOD OF VERY COLD CONDITIONS COULD ALSO BE IN THE
WORKS FOR THE LATTER PART OF NEXT WEEK...WITH THE POSSIBILITIES OF A
SYSTEM DIGGING SOUTHWARD OVER THE AREA FROM THE HIGH LATITUDES OF
CANADA.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* NORTHWEST WINDS WITH ERRATIC SPEEDS BETWEEN 12 AND 17 KT GUSTING
TO AROUND 25 KT OR SO THROUGH AT LEAST MIDNIGHT...TAPERING SOME
OVERNIGHT.
* MVFR CIGS LIFTING TO VFR LATE EVENING OR EARLY TONIGHT.
* FLURRIES THIS EVENING POSSIBLY REDUCING VSBY TO MVFR.
MDB
//DISCUSSION...UPDATED 22Z...
NORTHWEST WINDS CONTINUE TO BE QUITE VARIABLE IN SPEED. ONE UPPER
WAVE IS CROSSING THE AREA AND AM THINKING THAT WINDS WILL PICK UP
A BIT CLOSER TO 00Z BEHIND THIS WAVE. ANOTHER WAVE WILL THEN CROSS
MID EVENING AND MAY RESULT IN ANOTHER BRIEF DECREASE IN SPEEDS
BEFORE INCREASING AGAIN LATE THIS EVENING. CIGS HAVE IMPROVED
UPSTREAM TO THE NORTH SO HAVE GONE WITH SLIGHTLY HIGHER CIGS IN
THE LATEST TAF BUT MAY NEED TO SPEED THE IMPROVEMENT TO VFR BY A
FEW HOURS.
MDB
FROM 18Z...
MAIN AVIATION CONCERN IS WITH GUSTY NW WINDS THIS AFTERNOON AND
TONIGHT. WE HAVE HAD A HARD TIME REALIZING DEEPER MIXING WITH THE
SOLID MVFR CLOUD DECK IN PLACE. WE HAVE SEEN OCCASIONAL 30 KT
GUSTS ON 1-MINUTE ASOS OBSERVATIONS...BUT IN GENERAL SUSTAINED
WINDS HAVE BEEN IN THE MID TO UPPER TEENS WITH GUSTS INTO THE MID
20S. EXPECT THESE WINDS TO REMAIN IN PLACE THIS AFTERNOON AND
EVENING AS A SECOND WAVE OF COLD AIR ADVECTION ENSUES TONIGHT.
NEXT CONCERN IS AROUND MVFR CIGS AND POSSIBLE FLURRIES TONIGHT.
CIGS SHOULD GENERALLY REMAIN ABOVE 1500 FT WITH THE GUSTY WINDS
AND MIXED VERY LOW LEVELS. A WEAKER TROUGH AXIS WILL MOVE THROUGH
THE TERMINALS THIS AFTERNOON...FOLLOWED BY A SHARPER VORT MAX THIS
EVENING. UPSTREAM OBSERVATIONS IN NORTHERN MINNESOTA AHEAD OF THIS
WAVE HAVE BEEN REPORTING SOME FLURRIES AND POSSIBLY EVEN SOME
FREEZING DRIZZLE. AS THIS WAVE MOVES THROUGH THIS EVENING...LOWER
LEVEL TEMPERATURES COOL TO THAT POINT TO SUPPORT SOME FLURRIES
AND POSSIBLE VISIBILITY REDUCTION IF THIS ACTIVITY. CONFIDENCE ON
THIS IS LOW ON SPECIFICALLY IMPACTING ANY PARTICULAR TERMINAL...SO
IT HAS NOT BEEN MENTIONED IN THE TAFS AT THE MOMENT. BUT
CONFIDENCE IS PRETTY HIGH THAT THE MVFR CIGS LINGER THROUGH MUCH
OF THE NIGHT. HIGH PRESSURE BUILDS IN TOMORROW WHICH RESULTS IN
LIGHTER WINDS AND LIKELY SOME SCATTERING OUT OF THE LOW CLOUD
DECK...BUT CONFIDENCE TIMING THE SCATTERING IS NOT VERY HIGH.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* HIGH IN SUSTAINED SPEEDS BEING ERRATIC AND MEDIUM-HIGH IN GUST
SPEEDS.
* MEDIUM CONFIDENCE IN TIMING OF IMPROVEMENT TO VFR CIGS AND TIME
OF SCATTERING. MAY NEED TO SPEED UP IMPROVEMENT TO VFR.
* LOW ON FLURRIES AND ANY ASSOCIATED VSBY REDUCTION THIS EVENING.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR. SOUTHWEST WINDS.
SATURDAY...CHANCE OF SNOW AND IFR DURING THE NIGHT. WEST WINDS.
SUNDAY...CHANCE OF SNOW AND IFR. AT LEAST MVFR CIGS LIKELY.
NORTHEAST WINDS.
MONDAY NIGHT-WEDNESDAY...CHANCES OF MAINLY LIGHT SNOW. WEST WINDS.
MTF
&&
.MARINE...
153 PM CST
ACTIVE PATTERN LOOKS TO PERSIST THROUGH THE WEEKEND WITH MUCH
COLDER AIR ARRIVING EARLY NEXT WEEK. WITH THE SLOW AND STEADY
DEPARTURE OF TWO LOW PRESSURES OVER THE WESTERN GREAT LAKES THIS
MORNING...THE TWO LOWS ARE NOW CONSOLIDATING OVER NORTHEAST LAKE
HURON. ALONG THE BACK EDGE OF THESE LOW PRESSURES...THE PRESSURE
GRADIENT HAS TIGHTEN AND WAS PRODUCING GALE FORCE WINDS TO 35 KT
FROM THE NORTHWEST. MOST OF THE AFTERNOON WINDS HAVE BEEN HELD TO
AROUND LOW END GALES OR JUST UNDER GALE FORCE...HOWEVER AS THE
AFTERNOON PROGRESSED MIXING HAS BEEN ABLE TO BRING TO THE SURFACE
MUCH STRONGER WINDS. AS A RESULT WILL MAINTAIN THE CURRENT GALE
WARNING THROUGH THIS EVENING. WITH THE STRONGEST GRADIENT OVER THE
NORTHERN HALF OF THE LAKE...PRODUCING GALES TO 40KT AT TIMES...THIS WILL
LIKELY PRODUCE HEAVY FREEZING SPRAY. FURTHER SOUTH THE GALES WILL
LIKELY REMAIN AROUND 35KT AND THE FREEZING SPRAY SHOULD ONLY BE
ALONG THE MODERATE LEVEL AND NOT REQUIRE A HEADLINE.
WAVES WILL CONTINUE TO BUILD EARLY THIS EVENING...WITH THE HIGHEST
WAVES BETWEEN 12-15 FT TONIGHT. HIGH PRESSURE THEN QUICKLY ARRIVES
AND BRINGS LIGHTER WINDS TO THE LAKE BY MIDDAY FRIDAY. THEN HIGH
PRESSURE QUICKLY SLIDES EAST/SOUTHEAST...WITH WINDS TURNING
SOUTHERLY AHEAD OF YET ANOTHER LOW PRESSURE SYSTEM OVER THE
WEEKEND. A FRONTAL BOUNDARY WILL SLIDE SOUTH FROM CANADA
SATURDAY...AND COULD DEVELOP A TIGHT GRADIENT OVER THE LAKE FOR A
PERIOD SATURDAY NIGHT INTO SUNDAY. AT THIS TIME IT LOOKS LIKE
NORTH/NORTHEAST WINDS WILL TOP OUT AROUND 30KT...BUT COULD SEE A
FEW GALE FORCE GUSTS FOR A FEW HOURS EARLY SUNDAY. THEN HIGH
PRESSURE PUSHES OVER THE WESTERN GREAT LAKES SUNDAY NIGHT INTO
MONDAY. UNFORTUNATELY ANOTHER ACTIVE PATTERN LOOKS FAVORABLE FOR
EARLY NEXT WEEK.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...HEAVY FREEZING SPRAY WARNING...LMZ261-LMZ362-LMZ364-LMZ366-
LMZ563-LMZ565-LMZ567-LMZ868 UNTIL 3 AM FRIDAY.
GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742-
LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878 UNTIL 3 AM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
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WWW.YOUTUBE.COM/NWSCHICAGO
[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
330 PM CST Thu Jan 29 2015
.SHORT TERM...(Tonight)
ISSUED AT 329 PM CST THU JAN 29 2015
Forecast challenge for tonight will be whether or not any partial
clearing will occur and the affect on low temperatures. The latest
satellite loop early this afternoon indicated an area of partly
cloudy skies in central/southern MN into central IA behind a
departing shortwave trough. This area was starting to fill in with a
few more clouds, though, the past hour. The latest guidance from the
RAP, HRRR and NAM all indicate that moisture in the lowest 100 mb
should stay high enough overnight for low clouds to persist until
Friday morning. Breaks in the clouds may occur at times late this
evening, but they shouldn`t low enough to impact low temperatures.
As a result will go with lows in the 20-25 range across all of
central and southeast IL.
Patches of drizzle/flurries may linger in parts of central Illinois
early this evening. However, this will have very small areal
coverage and will have little or no impact, so will not include in
the forecast for tonight.
As the low pressure center moves through the eastern Great Lakes
late this evening, the pressure gradient should loosen up, resulting
in gradually diminishing winds in central Illinois early tonight,
and in eastern Illinois by daybreak.
&&
.LONG TERM...(Friday through Thursday)
ISSUED AT 329 PM CST THU JAN 29 2015
Models have come into better agreement with the main focus for this
forecast, this weekend winter weather system. The GFS and ECMWF both
look very similar with location of the heaviest snowfall Sat night
through Sun. Only differences in the those two models is the timing
and track of the low press area as it moves northeast across the
southern Miss valley. Precip will begin to spread into the western
parts of the CWA Sat afternoon, but temps will be warm enough for
most of the pcpn to be either rain, or a mix of rain or snow. No
accumulations are expected during the afternoon due to the warm
temps. The major part of the snow will arrive late Sat night, after
midnight, through some light accumulations are possible Sat evening.
After midnight, the snow is expected to become moderate with rates
approaching 1/2 inch per hour. The snow will be during the
overrunning period of the system as it begins to lift out of the
southern plains. With the upper level part of the system being just
an open trough/wave, a heavy deformation area of snow will likely
not setup on the back side of the low pressure area. However, snow
will continue Sun afternoon through Sun evening, with accumulations
being on the lighter side. Preliminary indications are that snowfall
totals from Sat evening through Sun night will be in the 4.5 to 6
inch range. There is still some uncertainty with these amounts as
the models are just now coming into agreement and some shift south
or north with the track is still possible. Given the longer duration
of the snowfall, it does not meet criteria for a watch at this time,
so no headlines will be issued. A later forecast shift may decide to
issue one if any changes occur with the model forecasts.
Beyond this system this weekend, conditions will be relatively dry,
except for Tue night when another chance of snow is possible from a
system coming down from the northwest. Once this system pushes
through, temps will drop and become well below normal for Wed
through Thur.
&&
.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
ISSUED AT 1206 PM CST THU JAN 29 2015
The main aviation concerns will be with MVFR ceilings and the
strong northwest wind gusts across central and eastern Illinois.
The latest satellite loop and surface observations indicated a
large area of MVFR ceilings across all of Illinois and much of
Iowa. The main question is the advancement of an area of partial
clearing from southern MN and central IA, and when the MVFR
ceilings will dissipate. The vast majority of short range models
indicate that a shortwave trough axis will swing through central
and eastern IL late this evening. However, most of these same
models including the NAM, RAP and HRRR indicate that there will be
plenty of low level moisture trapped below a stout inversion. This
would keep at least broken MVFR ceilings in the area through the
night and into much of Friday morning. Will follow this line of
thinking as it can be very difficult to erode low level clouds
this time of year.
The tight pressure gradient will keep northwest winds gusting
around 25-30 knots through the afternoon into early evening at
most TAF sites - particularly in east central Illinois. The
lessening impact of the surface low moving through the eastern
Great Lakes will result in diminishing wind in central IL late
this evening, and in eastern Illinois before daybreak.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Miller
LONG TERM...Auten
AVIATION...Miller
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
153 PM CST THU JAN 29 2015
.SHORT TERM...
358 AM CST
TODAY THROUGH FRIDAY NIGHT...
THE MAIN FORECAST CONCERNS THIS MORNING INVOLVE THE AREA OF LOW
PRESSURE CURRENTLY OVER WEST CENTRAL ILLINOIS...AND INCLUDE PRECIP
TIMING/TYPE...TEMPERATURE TRENDS...GUSTY WINDS...AND EVENTUALLY THE
POTENTIAL FOR SOME LAKE EFFECT SNOW SHOWERS OVER NORTHWEST INDIANA
TONIGHT INTO FRIDAY.
THE SURFACE LOW CENTER WAS JUST SOUTHWEST OF LASALLE/PERU ILLINOIS
AT 3 AM CST...WITH THE ASSOCIATED CYCLONIC WIND CIRCULATION PULLING
RELATIVELY MILD AIR NORTH ACROSS THE EASTERN 2/3 OF THE CWA.
CHALLENGING HOURLY TEMPERATURE FORECAST...AS READINGS MAY REACH 40
DEGREES IN THE SOUTHEAST EARLY THIS MORNING BEFORE THE LOW PASSES
AND SHIFTS WINDS TO THE NORTHWEST AND PULLS IN COLDER AIR. WITH THE
EXCEPTION OF A BAND OF RAIN SHOWERS LATE LAST EVENING...LITTLE
PRECIPITATION HAS BEEN OCCURRING WITH THIS SYSTEM EXCEPT NORTH/EAST
OF THE FORECAST AREA OVERNIGHT. REGIONAL RADAR MOSAIC HAS BEEN
DEPICTING PERSISTENT LIGHT RETURNS BEHIND THE LOW/COLD FRONT HOWEVER
WHERE SOME OCCASIONAL DRIZZLE OR "UNKNOWN" PRECIP HAS BEEN REPORTED.
HIGH-RES GUIDANCE TRENDS CONTINUE TO INDICATE SOME VERY LIGHT
PRECIPITATION IS POSSIBLE ACROSS THE AREA THIS MORNING...WITH
FORECAST SOUNDINGS INDICATING MAINLY DRIZZLE WITH SATURATION MAINLY
IN LOW LEVELS AS COLDER AIR MOVES IN...THOUGH A BRIEF PERIOD OF
MID-LEVEL MOISTURE WITH RAGGED DEFORMATION AREA ALONG WEST/NORTHWEST
SIDE OF THE LOW COULD BRIEFLY INTRODUCE ICE INTO LOW LEVELS IN A
SEEDER-FEEDER SITUATION WHICH COULD RESULT IN A MIX OF DRIZZLE/LIGHT
RAIN AND LIGHT SNOW THIS MORNING...THOUGH NOT EXPECTING ANY REAL
MEASURABLE PRECIPITATION OR SNOW WITH THIS. STRONG DRYING ABOVE THE
BOUNDARY LAYER FROM THE NORTHWEST BY MIDDAY SHOULD ALLOW ANY LIGHT
PRECIP TO END FROM WEST TO EAST THROUGH THE LATE MORNING AND MIDDAY
HOURS.
WINDY CONDITIONS WILL DEVELOP DURING THE MORNING AS COLD ADVECTION
STEEPENS OUR LOW LEVEL LAPSE RATES IN THE TIGHT PRESSURE GRADIENT
WEST OF THE LOW. FORECAST SOUNDINGS INDICATE GUSTS AROUND 35 MPH
WILL BE POSSIBLE FROM MID-MORNING THROUGH THE AFTERNOON BEFORE WINDS
GRADUALLY DIMINISH TONIGHT. A QUICK NOTE OF TEMPERATURES WEST OF THE
LOW THIS MORNING INDICATES READINGS DO NOT DROP OFF TOO DRAMATICALLY
AND WILL LIKELY SEE STEADY TEMPS FOR THE MOST PART UNTIL LATE TODAY.
(EXCEPT IN THE SOUTHEAST WHERE TEMPS APPROACH 40 THIS MORNING...WILL
LIKELY SETTLE BACK TO THE MID 30S THERE).
AS FOR LAKE EFFECT TONIGHT...LOW LEVEL WINDS FROM THE
NORTH-NORTHWEST (AROUND 340 DEG) SUPPORT AN INITIAL CONVERGENCE ZONE
ALONG THE SOUTHWEST MICHIGAN SHORE THIS AFTERNOON AND EARLY THIS
EVENING...THOUGH OUR LOCALLY RUN ARW MODEL DOES VEER WINDS LATER
TONIGHT AND BRINGS CONVERGENT BAND INTO PORTER COUNTY LATE TONIGHT
INTO EARLY FRIDAY. LARGER SCALE FLOW BACKS MORE WESTERLY FRIDAY
AFTERNOON WHICH SHOULD PUSH ANY LINGERING SNOW SHOWERS BACK EAST OF
PORTER COUNTY BY MID/LATE FRIDAY AFTERNOON. THERMODYNAMICS ARE NOT
SPECTACULAR...THOUGH VARIOUS MODEL FORECAST SOUNDINGS DEVELOP
LAKE-850 HPA DELTA-T AROUND 17C EARLY FRIDAY WITH INVERSION HEIGHTS
5000-6000 FT BEFORE CONDITIONS GRADUALLY WANE LATER FRIDAY MORNING.
DEPENDING UPON HOW LONG THE BAND BACKS UP INTO PORTER/EASTERN LAKE
COUNTIES WILL MODULATE THE SNOWFALL ACCUMULATION POTENTIAL...THOUGH
A FEW INCHES ARE CERTAINLY POSSIBLE IF THE BAND DOES HANG UP THERE
FOR A WHILE LATE TONIGHT/EARLY FRIDAY...BEFORE EXPANSIVE SURFACE
HIGH BUILDS ACROSS THE AREA THROUGH FRIDAY NIGHT.
RATZER
&&
.LONG TERM...
358 AM CST
SATURDAY THROUGH WEDNESDAY...
THE MAIN CONCERN IN THE EXTENDED PERIOD CONTINUES TO BE THE
POTENTIAL FOR SOME ACCUMULATING SNOW OVER THE WEEKEND...ESPECIALLY
ACROSS THE SOUTHERN PART OF THE CWA LATE SATURDAY NIGHT AND SUNDAY.
GLOBAL RUNS CONTINUE TO SHOW AGREEMENT IN FIRST SAGGING A COLD FRONT
SOUTH ACROSS THE AREA SATURDAY...THEN WITH THE AMPLIFICATION OF AN
UPPER TROUGH OVER THE REGION WITH SUBSEQUENT SURFACE LOW DEVELOPMENT
OVER THE LOWER MISSISSIPPI VALLEY. WHILE THE TRACK OF THE SURFACE
LOW HAS TRENDED SOUTH OVER THE PAST FEW RUNS (NOW FROM THE LOWER
MISS VALLEY TO THE MID-ATLANTIC OR CAROLINA COAST BY MONDAY
MORNING)...NORTHERN PERIPHERY OF DEFORMATION BAND SNOW ACROSS
CENTRAL ILLINOIS/INDIANA WOULD STILL AFFECT SOUTHERN COUNTIES OF THE
LOT CWA AT THIS POINT. IN ADDITION...INCREASING NORTH-NORTHEAST
WINDS NORTH OF THE LOW TRACK COMBINED WITH ARCTIC AIR INTRUSION
BEHIND SATURDAY COLD FRONT COULD VERY WELL LEAD TO LAKE
EFFECT/ENHANCED SNOW SHOWERS INTO THE CHICAGO METRO AREA. SO...
WHILE MANY DETAILS REMAIN TO BE WORKED OUT HAVE MAINTAINED DECENT
CHANCE POPS FOR MEASURABLE SNOW ACROSS THE FORECAST AREA FOR THE
WEEKEND. STILL LOOKS COLD BEYOND THE WEEKEND INTO NEXT WEEK WITH
DEEP TROUGH ACROSS THE EAST...THOUGH PATTERN CONTINUES TO BE
PROGRESSIVE IN LONGER RANGE GUIDANCE SOLUTIONS WHICH KEEPS IT FROM
STICKING AROUND TOO LONG.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* NORTHWEST WINDS GUSTING TO AROUND 25 KT OR SO THROUGH AT LEAST
MIDNIGHT...TAPERING SOME OVERNIGHT.
* MVFR CIGS PERSISTING INTO THE EVENING...LIFTING TO VFR EITHER
OVERNIGHT OR INTO FRIDAY MORNING.
* FLURRIES THIS EVENING REDUCING VSBY TO MVFR.
KMD
//DISCUSSION...UPDATED 18Z...
MAIN AVIATION CONCERN IS WITH GUSTY NW WINDS THIS AFTERNOON AND
TONIGHT. WE HAVE HAD A HARD TIME REALIZING DEEPER MIXING WITH THE
SOLID MVFR CLOUD DECK IN PLACE. WE HAVE SEEN OCCASIONAL 30 KT
GUSTS ON 1-MINUTE ASOS OBSERVATIONS...BUT IN GENERAL SUSTAINED
WINDS HAVE BEEN IN THE MID TO UPPER TEENS WITH GUSTS INTO THE MID
20S. EXPECT THESE WINDS TO REMAIN IN PLACE THIS AFTERNOON AND
EVENING AS A SECOND WAVE OF COLD AIR ADVECTION ENSUES TONIGHT.
NEXT CONCERN IS AROUND MVFR CIGS AND POSSIBLE FLURRIES TONIGHT.
CIGS SHOULD GENERALLY REMAIN ABOVE 1500 FT WITH THE GUSTY WINDS
AND MIXED VERY LOW LEVELS. A WEAKER TROUGH AXIS WILL MOVE THROUGH
THE TERMINALS THIS AFTERNOON...FOLLOWED BY A SHARPER VORT MAX THIS
EVENING. UPSTREAM OBSEVATIONS IN NORTHERN MINNESOTA AHEAD OF THIS
WAVE HAVE BEEN REPORTING SOME FLURRIES AND POSSIBLY EVEN SOME
FREEZING DRIZZLE. AS THIS WAVE MOVES THROUGH THIS EVENING...LOWER
LEVEL TEMPERATURES COOL TO THAT POINT TO SUPPORT SOME FLURRIES
AND POSSIBLE VISIBILITY REDUCTION IF THIS ACTIVITY. CONFIDENCE ON
THIS IS LOW ON SPECIFICALLY IMPACTING ANY PARTICULAR TERMINAL...SO
IT HAS NOT BEEN MENTIONED IN THE TAFS AT THE MOMENT. BUT
CONFIDENCE IS PRETTY HIGH THAT THE MVFR CIGS LINGER THROUGH MUCH
OF THE NIGHT. HIGH PRESSURE BUILDS IN TOMORROW WHICH RESULTS IN
LIGHTER WINDS AND LIKELY SOME SCATTERING OUT OF THE LOW CLOUD
DECK...BUT CONFIDENCE TIMING THE SCATTERING IS NOT VERY HIGH.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH IN WINDS...MEDIUM ON GUSTS.
* HIGH IN MVFR CIGS ABOVE 1800 FT THROUGH AT LEAST MIDNIGHT. LOW-
MEDIUM ON SPECIFIC SCATTERING TIME...WHICH WOULD COULD BE
BETWEEN 6Z AND 9Z BUT MOST LIKELY BE SOME TIME AFTER 12Z.
* LOW ON FLURRIES AND ANY ASSOCIATED VSBY REDUCTION THIS EVENING.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR. SOUTHWEST WINDS.
SATURDAY...CHANCE OF SNOW AND IFR DURING THE NIGHT. WEST WINDS.
SUNDAY...CHANCE OF SNOW AND IFR. AT LEAST MVFR CIGS LIKELY.
NORTHEAST WINDS.
MONDAY NIGHT-WEDNESDAY...CHANCES OF MAINLY LIGHT SNOW. WEST WINDS.
MTF
&&
.MARINE...
205 AM CST
A PROGRESSIVE ACTIVE PATTERN WILL CONTINUE ACROSS THE GREAT LAKES
REGION INTO THE BEGINNING OF FEBRUARY. MOVING EASTWARD EARLY THIS
MORNING IS AN ELONGATED TROUGH WITH TWO LOW PRESSURE CENTERS
COMPOSING IT...ONE PASSING JUST SOUTH OF LAKE MICHIGAN AND ANOTHER
OVER EASTERN LAKE SUPERIOR. TOGETHER THESE WILL CONSOLIDATE LATER
TODAY AND DRIVE MORE FOCUSED AND STRENGTHENING COLD ADVECTION
OVER LAKE MICHIGAN. THIS WITHIN THE STRONG AND ADVECTING PRESSURE
GRADIENT WILL SUPPORT NORTHWEST TO NORTH GALES...EVEN 45 KT GUST
POTENTIAL ACROSS PARTS OF THE NORTH. THE ILLINOIS AND ESPECIALLY
THE INDIANA NEAR SHORES SHOULD AT LEAST EXPERIENCE PERIODIC GALE
GUSTS INTO THIS EVENING. COLDER TEMPERATURES WILL BE WORKING
SOUTHWARD ACROSS THE LAKE LATER TODAY AND TONIGHT. SUPPORT FOR
HEAVY FREEZING SPRAY REMAINS OVER MAINLY THE NORTH AND CONTINUE
THE WARNING THERE. WAVES ARE LIKELY TO BUILD TO 12-15 FT TONIGHT
AT DOWNSTREAM FETCH LOCATIONS ON THE EASTERN HALF OF THE LAKE.
WINDS WILL GRADUALLY DIMINISH OVERNIGHT INTO FRIDAY MORNING AND
MORE QUICKLY AFTERWARD AS HIGH PRESSURE MOVES OVER THE LAKE.
BEYOND...THERE LOOKS LIKE OPPORTUNITIES FOR AT LEAST 30 KT WINDS
NEXT WEEK. ONE OF THESE IS BEHIND A COLD FRONT SATURDAY AFTERNOON
AND MORE SO SATURDAY NIGHT. MORE 30 KT WIND POTENTIAL WOULD COME
POSSIBLY TUESDAY AS RETURN SOUTHWEST FLOW SPREADS BACK OVER THE
LAKE.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742-
LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878 UNTIL 3 AM FRIDAY.
HEAVY FREEZING SPRAY WARNING...LMZ261-LMZ362-LMZ364-LMZ366-
LMZ563-LMZ565-LMZ567-LMZ868 UNTIL 3 AM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1207 PM CST Thu Jan 29 2015
.UPDATE...
ISSUED AT 1054 AM CST THU JAN 29 2015
Only minor updates were made to the forecast for this afternoon in
central and southeast Illinois. The latest satellite loop shows
plenty of cloud cover upstream, so cloudy conditions will prevail
until at least tonight. There is a weak shortwave embedded in the
northwest flow across southeast Iowa. This should bring a period
of drizzle to west central Illinois early this afternoon, so
included that in the forecast west of I-55.
A steep pressure gradient will keep windy conditions in place this
afternoon, especially in central and eastern IL. Increased the
gusts slightly in a few places, otherwise the current forecast has
a good handle on the gusty northwest winds.
The cloud cover and weak low level cold advection will keep
temperatures fairly steady through the afternoon in the 35-40
range across the entire area.
&&
.SHORT TERM...(Today)
ISSUED AT 447 AM CST THU JAN 29 2015
Low pressure centered just north of Moline at 08z/2am will continue
to push east and drag a cold front through our area this morning.
Warmest temperatures will be just ahead of the cold front early this
morning, and then we expect temperatures to fall off quickly just
behind the cold front during the remainder of the morning, and then
hold fairly steady this afternoon. Winds will be gusty again today
but this time out of the northwest with a few gusts of 35 to 40 mph
at times about an hour or two after frontal passage right along the
stronger surface pressure rises. Look for gusts in the 30 to 35 mph
range this afternoon.
Not seeing a lot of precip, other than some occasional very light
rain/drizzle out in Iowa so will continue with just a slight chance
of light rain/snow this morning with POPs decreasing from west to
east this afternoon, and that would be mainly across the north half
of the forecast area. Latest satellite data and upstream surface
observations not showing much hope for any clearing across our area
in the near term. Forecast soundings off the NAM-WRF showing a
fairly strong subsidence inversion setting up again in the wake of
this system resulting in quite a bit of low level moisture trapped
beneath the inversion at around 2500-3000 feet. As a result, we have
backed off with any decrease in cloud cover until later this evening
and that may be optimistic based on the latest (06z) forecast
soundings off the NAM.
&&
.LONG TERM...(Tonight through Wednesday)
ISSUED AT 447 AM CST THU JAN 29 2015
Short wave trof to exit east and se of IL early this evening as
Canadian high pressure over the Canadian Rockies settles into the
upper Midwest tonight. However an inversion will likely trap low
level clouds longer tonight and have trended the forecast slower
with decreasing low clouds from the west. Low clouds could linger
over ne counties into Friday morning especially near IN border.
Cooler lows tonight in upper teens to near 20F northern areas to mid
20s in southeast IL. Brisk nw winds 15-25 mph this evening to slowly
diminish during overnight into Friday morning as high pressure
settles into IL on Friday. Highs Friday 29-35F with coolest readings
from I-74 ne with partly to mostly sunny skies.
High pressure settles into the Ohio river valley Friday evening and
into central Appalachians by dawn Sat and continue fair/dry weather
through at least Saturday morning. Lows Friday night in upper teens
and lower 20s again. Milder highs Sat in upper 30s and lower 40s
with mildest readings sw areas with ssw breezes. Clouds to increase
later Friday night into Sat ahead of next storm system with slight
chance of light rain/snow later Saturday afternoon west of I-55. Most
over central and especially eastern IL should still be dry through the
daytime hours on Saturday.
12Z Jan 28 forecast models trended further south with low pressure
system Sat night and Sunday, while 00Z Jan 29 forecast models have
trended back north with more phasing of southern and northern stream
upper level systems, along with higher snowfall amounts over central
and southeast IL. 00Z models have also trended colder with even
southeast IL looking like all snow with this eveng and mixed
precipitation south of I-64 toward the ohio river. Confidence is not
too high yet with this potentially high impact winter weather event
with extended period of overrunning snow developing Saturday night
and continue through Sunday before diminishing Sunday night. Several
inches of snow still appears possible over central and southeast IL.
Canadian high pressure settles into IL Monday returning dry and
colder weather. A northern stream short wave races ese into Great
Lakes region late Tue and Tue night bringing small chances of light
snow with best chances ne of central IL. Another Canadian high
pressure settles into region by Thu brining in even colder air. So
after above normal temps overall since mid Jan, next week (first
week of Feb) looks like temps will likely be below normal.
&&
.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
ISSUED AT 1206 PM CST THU JAN 29 2015
The main aviation concerns will be with MVFR ceilings and the
strong northwest wind gusts across central and eastern Illinois.
The latest satellite loop and surface observations indicated a
large area of MVFR ceilings across all of Illinois and much of
Iowa. The main question is the advancement of an area of partial
clearing from southern MN and central IA, and when the MVFR
ceilings will dissipate. The vast majority of short range models
indicate that a shortwave trough axis will swing through central
and eastern IL late this evening. However, most of these same
models including the NAM, RAP and HRRR indicate that there will be
plenty of low level moisture trapped below a stout inversion. This
would keep at least broken MVFR ceilings in the area through the
night and into much of Friday morning. Will follow this line of
thinking as it can be very difficult to erode low level clouds
this time of year.
The tight pressure gradient will keep northwest winds gusting
around 25-30 knots through the afternoon into early evening at
most TAF sites - particularly in east central Illinois. The
lessening impact of the surface low moving through the eastern
Great Lakes will result in diminishing wind in central IL late
this evening, and in eastern Illinois before daybreak.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Miller
SHORT TERM...Smith
LONG TERM...07
AVIATION...Miller
AREA FORECAST DISCUSSION
NWS DES MOINES IA
315 PM CST THU JAN 29 2015
.SHORT TERM /TONIGHT/...
ISSUED AT 315 PM CST THU JAN 29 2015
MAIN FORECAST CONCERN DEALT WITH LINGERING STRATUS DECK
AND TEMPERATURES AS A RESULT OF THE LINGERING CLOUD COVER. LEANED
TOWARD THE NAM/RAP/HRRR FOR CLOUD COVER AND LOW LEVEL RH THIS
EVENING. SOUNDINGS SUGGEST THE INVERSION CONTINUES THROUGH FRIDAY
MORNING AND POTENTIALLY TRAPPING THE LOW LEVEL MOISTURE/STRATUS OVER
CENTRAL IOWA DURING MUCH OF THE NIGHT. THERE IS A DECENT BREAK IN
THE CLOUD DECK OVER NORTH-CENTRAL IOWA AND INTO SOUTHERN MINNESOTA
AS OF 21Z...AND THE HRRR HAS SOMEWHAT PICKED UP ON THIS TREND AND
SLOWLY ERODES THE STRATUS BY AROUND 05Z ACROSS IOWA/MINNESOTA. HAVE
STRATUS SLOWLY ERODING DURING THE EVENING HOURS WITH THE NORTHEAST
SLOWEST TO CLEAR OUT.
CAA CONTINUES THROUGHOUT MUCH OF THE NIGHT BEFORE THE SURFACE RIDGE
SLIDES INTO NORTHERN IOWA FRIDAY MORNING AND FINALLY ALLOWING THE
WINDS TO BECOME LIGHT AND VARIABLE. SO ANY RADIATIONAL COOLING WILL
BE CLOSER TO SUNRISE. WITH THE TEMPERATURES REMAINING FAIRLY COLD
THIS AFTERNOON...LEANED TOWARD THE RAP FOR LOWS TONIGHT AS IT SEEMED
TO HAVE A BETTER HANDLE ON TEMP AND CLOUD COVER TRENDS.
.LONG TERM /FRIDAY THROUGH THURSDAY/...
ISSUED AT 315 PM CST THU JAN 29 2015
MUCH OF THE LONG TERM FORECAST WILL BE DOMINATED BY BROAD
NORTHWEST FLOW AND A SERIES OF WAVES MOVING THROUGH THE FLOW.
SURFACE RIDGING WILL BE ACROSS THE STATE AT THE BEGINNING OF THE
LONGER TERM TOMORROW MORNING WITH FRIDAY BEING THE BEST DAY OUT OF
REMAINDER OF THE FORECAST. WARM ADVECTION WILL INCREASE BY LATER
IN THE DAY AS SOUTHERLY SURFACE FLOW RESUMES AND READINGS ONCE
AGAIN ABOVE NORMAL. A DECENT PRESSURE GRADIENT KEEPING WINDS UP ON
FRIDAY NIGHT ALONG WITH INCREASING CLOUDINESS WILL HELP KEEP
TEMPERATURES QUITE WARM OVERNIGHT. MAY BEGIN TO SEE SOME LIGHT
PRECIPITATION IN THE FAR SOUTHWEST TOWARD DAYBREAK BUT THE BULK OF
THE SYSTEM WILL COME IN LATER PERIODS.
MOVING INTO THE WEEKEND...ALL FOCUS SHIFTS TO A SHORTWAVE TOPPING
THE WESTERN RIDGE AND ITS INTERACTION WITH A VERY MOIST UPPER LOW
ACROSS THE SOUTHWEST UNITED STATES. THE 12Z MODELS ARE BEGINNING
TO CLUSTER AROUND A SOLUTION OF DROPPING THE NORTHERN SHORTWAVE
SOUTHEAST WITH SUFFICIENT AMPLITUDE TO BRING THE MOISTURE PLUME
FAR ENOUGH NORTH TO IMPACT IOWA...AT LEAST THE SOUTHERN HALF OR
SO. INITIALLY...A SHORTWAVE THAT PASSES THROUGH THE GREAT LAKES
AREA FRIDAY NIGHT WILL SEND A COLD FRONT SOUTHWARD THRU THE
FORECAST AREA ON SATURDAY. MEANWHILE..INCREASING ISENTROPIC LIFT
AND MOISTURE ADVECTION WILL LEAD TO PRECIPITATION DEVELOPMENT
ACROSS SOUTHERN IOWA ON SATURDAY MORNING AHEAD OF THE BOUNDARY.
THE PRECIPITATION WILL LIKELY BE RAIN IN FAR SOUTHERN IOWA WITH
TEMPERATURES IN THE MID TO UPPER 30S. HOWEVER...A TRANSITION TO
SNOW IS LIKELY BY I80 OR HWY30 AS COLDER AIR IS ENCOUNTERED WITH
THE SOUTHWARD MOVING BOUNDARY. FORCING WILL SUSTAIN AND INCREASE
INTO SATURDAY NIGHT WITH DECENT MID LEVEL FRONTOGENETICAL FORCING
ACROSS THE SOUTHERN IOWA. ANY RAIN IN THE SOUTH ON SATURDAY WILL
TRANSITION TO SNOW IN THE EVENING AS COLD AIR CONTINUES TO DEEPEN
AND SPREAD SOUTHWARD BEHIND THE BOUNDARY. BY LATE SATURDAY NIGHT
INTO SUNDAY...DECENT MID LEVEL FORCING FROM APPROACHING SOUTHEAST
MOVING SHORTWAVE WILL HELP SNOW TO CONTINUE DURING THE DAY.
EVENTUALLY...THE FORCING WILL SHIFT TO THE EAST BY LATE IN THE DAY
WITH THE SNOW ENDING. THERE WILL BE A TIGHT GRADIENT OF SNOWFALL
ON NORTHERN SIDE OF PRECIPITATION SHIELD AND THEREFORE THE SNOW
AMOUNTS THAT ACCOMPANY THIS SYSTEM. AT THIS POINT...THE GRADIENT
APPEARS NEAR THE I80 CORRIDOR ALTHOUGH THIS WILL LIKELY MOVE WITH
SUBSEQUENT INFORMATION. GIVEN THE LONG DURATION OF THIS EVENT...IT
DOESNT APPEAR WARNING CRITERIA WILL BE MET...ALTHOUGH THE
COMBINATION OF WINDS AND SNOW MAY BE ENOUGH TO BOOST US INTO
WARNING. GIVEN THE CHANGES IN MODEL RUNS OVER THE PAST 36
HOURS...WILL WAIT ON ANY HEADLINES BUT BEGIN TO HIGHLIGHT MORE IN
THE HWO AND OTHER PRODUCTS. AMOUNTS OF AROUND 6 INCHES SEEM
POSSIBLE NEAR THE MO BORDER WITH 2-5 IN CENTRAL IOWA...AND AN INCH
OR LESS ACROSS THE NORTH.
MUCH COLDER AIR WILL FILTER INTO THE STATE FOR NEXT WEEK WITH A
SERIES OF SHORTWAVES PASSING THROUGH THE REGION. THIS WILL BRING
THE THREAT OF SNOW MONDAY NIGHT INTO TUESDAY WITH REINFORCING
SHOTS OF COLDER AIR.
&&
.AVIATION...29/18Z
ISSUED AT 1126 AM CST THU JAN 29 2015
MVFR CIGS LOOK TO PERSIST THROUGH THIS EVENING AND POTENTIALLY
INTO FRIDAY MORNING. CONFIDENCE IS HIGHER AT MCW/ALO AND EVEN OTM
FOR THE STRATUS TO LINGER A BIT LONGER...BUT CERTAINLY FOD AND DSM
EXTENDED THE MVFR CIGS TIME FRAME THROUGH LATE THIS EVENING.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...COGIL
AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1115 AM CST Thu Jan 29 2015
.UPDATE...
Issued at 632 AM CST THU JAN 29 2015
The stronger wind gusts seems to be more isolated than earlier,
and overall obs show winds speeds below 30 MPH. With the RAP and
NAM showing the pressure gradient remaining at its current
magnitude or gradually weakening, will allow the wind advisory to
expire at 7 am. Nevertheless northwest winds of 15 to 25 MPH will
persist through much of the day.
&&
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 424 AM CST THU JAN 29 2015
A shortwave could be seen on the 08Z water vapor imagery passing
overhead into MO with a second shortwave moving southeast through SD
and WY. an upper level low pressure system was seen spinning well
off the Baja California coast and shortwaves within faster flow near
40N and 145W were moving towards the British Columbia coast. At the
surface, high pressure was building south through the central plains
causing gusty northwest winds from a tight pressure gradient. In
fact the gradient has been strong enough for sustained winds of
30 MPH and an occasional gust up to 45 MPH. Because of this, have
issued a wind advisory until 7 am. By then the pressure gradient
is expected to begin relaxing.
For today and tonight, the weather should remain relatively quiet
due to increasing dry air as the surface high pressure system
continues to move south. Because of this the shortwave over SD and
WY is not expected to do much in terms of sensible weather. However
subsidence behind this wave should help to erode away the low
stratus that has moved in, and think skies should clear out by the
late afternoon. Since there is not a lot of cold air behind this
front and models show the boundary layer mixing to almost 850MB,
think highs in the middle 40s looks reasonable. Lows tonight should
be a bit colder as the ridge axis moves in creating light winds with
clear skies. Expecting good radiational conditions, have adjusted
min temps down to around 20. Models show pretty high RH values
developing Friday morning suggestive of fog. Am not real confident
in fog formation since we have not had any meaningful precip lately
and soils remain very dry. Because of this think dewpoints are
likely to remain a couple degrees cooler than the air temp.
.LONG TERM...(Friday through Wednesday)
Issued at 424 AM CST THU JAN 29 2015
Gradual warm advection will take place through the day Friday
following a cold start and the arrival of the thicker high clouds
now appears will be delayed...therefore highs should recover back into
the low to middle 40s for highs.
Friday night...low and mid level warm air and moisture advection
will increase across the county warning area and persist into
Saturday. Although the atmosphere will initially be very dry
across the CWA...saturation will slowly occur west to east across
the CWA as warm air and moisture advection increases. Will maintain
a slight chance for precip over the north central in the
evening...with a increasing chances all areas overnight. Forecast
soundings Friday night continue to trend slightly warmer and
dewpoints increasing slightly as well. With still a fairly shallow
depth of warm air in place in the low levels...precip could fall as
rain or snow...although if surface temps fall to or below
freezing...precip would likely be snow. Will continue to carry a
rain/snow chance most areas Friday night...then mainly north of I 70
through Saturday. Areas south of I 70 should mainly be rain by
Saturday afternoon as freeze levels slowly increase in the
afternoon.
By late afternoon the GFS is the most aggressive with the arrival of
the colder air/front across the northern CWA with a possible
changeover to all snow which would slowly spread southward through
Saturday night. The EC and GEM are a little slower but still brings
the colder air southward through the night. Snow chances linger
through Sunday morning most areas...but should also decrease with
time as the main upper trough pushes through. At this
point...snowfall amounts look to be in the 1 to 2 inch range most
areas...but could be locally higher across the northern CWA if the
cold air moves in quicker.
After highs Saturday around 40...colder and blustery conditions will
be the rule Sunday with highs in the upper 20s to around 30 degrees.
Although wind speeds will decrease Sunday night...low temps in the 7
to 12 degree range will produce wind chills near zero.
Return flow to the south Monday should allow temps to recover back
into the upper 20s/lower 30s...then the lower 40s Tuesday before
another shortwave trough moving through the northern Plains pushes a
front through the area that night with slightly cooler highs in the
30s and low 40s on Wednesday. For now appears any snow chance will
remain north of the area.
&&
.AVIATION...(For the 18Z TAFs through 18Z Friday Afternoon)
Issued at 1109 AM CST THU JAN 29 2015
VFR ceilings will persist through the evening hours before exiting
the region. A surface ridge will cause light and variable winds
overnight with mostly clear skies. Limited moisture should prevent fog
development although conditions may support reduced visibilities during
the predawn hours. Winds will gradually veer through the period
and eventually end up out of the south.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Wolters
SHORT TERM...Wolters
LONG TERM...63
AVIATION...Sanders
AREA FORECAST DISCUSSION
NWS JACKSON KY
211 PM EST THU JAN 29 2015
.UPDATE...
ISSUED AT 1225 PM EST THU JAN 29 2015
MADE MULTIPLE UPDATES BASED ON OBS AND NEW 12Z NAM. THIS INCLUDES
RAISING TEMPS FOR TODAY AND ADJUSTING TEMPS FOR TONIGHT INTO FRIDAY.
HAVE ALSO ADJUSTED SKY COVER TO ACCOUNT FOR TEMPORARY CLEARING TAKING
PLACE TODAY. TIMED POPS BASED ON NEW 12Z NAM TO INCLUDE THE BREAK IN
PRECIP THAT IS CURRENTLY OCCURRING. ADJUSTED SNOW POTENTIAL BASED ON
-10C MOISTURE AVAILABILITY ALOFT FOR TONIGHT.
UPDATE ISSUED AT 1113 AM EST THU JAN 29 2015
WITH PRECIP ON THE WAY OUT AND NO MORE OBSERVED TEMPS AT OR BELOW
FREEZING IN VALLEYS AND READINGS CONTINUING TO WARM...HAVE ALLOWED
THE WSW TO EXPIRE. HAVE ISSUED ANOTHER SPS UNTIL EARLY AFTERNOON FOR
ANY LINGERING PREVIOUSLY EXISTING ICE.
UPDATE ISSUED AT 1013 AM EST THU JAN 29 2015
WITH REPORTS OF MANY ACCIDENTS...ISSUED A FREEZING RAIN ADVISORY FOR
LOCATIONS WHERE VALLEYS TEMPS ARE BELOW FREEZING AND PRECIP IS STILL
OCCURRING. TEMPS ARE WARMING...SO THE ADVISORY ONLY RUNS FOR ABOUT
ANOTHER HOUR. WILL EVALUATE TEMPS IN A WHILE TO SEE IF IT CAN EXPIRE.
UPDATE ISSUED AT 844 AM EST THU JAN 29 2015
PRECIP SHIELD HAS MADE IT INTO OUR WESTERN FORECAST AREA.
TEMPERATURES HAVE RESPONDED WELL WHERE MEASURABLE PRECIPITATION IS
FALLING...HOWEVER SOME VALLEYS IN THE EAST STILL LINGER IN THE MID
20S. LOOKING AT RADAR TRENDS...THE MEASURABLE PRECIPITATION SEEMS TO
BE HAVING A HARDER TIME COMING EAST WITH SOME DOWNSLOPE FLOW IN
PLACE...AND READINGS HAVE BEEN EDGING UP EVEN IN THE COLDER SPOTS
PRIOR TO THE PRECIP ARRIVING. HAVE BEEFED UP POPS TO CATEGORICAL
ACROSS THE BOARD...AND WILL CONTINUE TO MENTION A CHANCE OF FREEZING
RAIN...AS SOME SPOTTY SLICK SPOTS STILL LOOK POSSIBLE. UPDATES HAVE
BEEN SENT.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 400 AM EST THU JAN 29 2015
LATEST SURFACE MAP FEATURES HIGH PRESSURE ALONG THE EASTERN
CONUS...WITH LOW PRESSURE MOVING INTO THE GREAT LAKES AND OHIO VALLEY
REGIONS. ALOFT...A SHORT WAVE TROUGH IS ROTATING TOWARDS THE OHIO
VALLEY...WITH ANOTHER TROUGH DROPPING SOUTHEAST INTO THE NORTHERN
PLAINS...AND YET ONE MORE MOVING IN ACROSS SOUTH CENTRAL CANADA.
MAINLY MID AND HIGH LEVEL CLOUDS HAVE BEEN STREAMING IN ACROSS
EASTERN KENTUCKY. THE SOUTHERLY WIND FLOW OUT AHEAD OF THE
APPROACHING SURFACE LOW HAS ALLOWED FOR A NICE RIDGE/VALLEY SPLIT
ACROSS THE AREA...WITH MORE SHELTERED VALLEYS HOLDING IN THE LOW AND
MID 20S...WHILE RIDGE TOPS ARE IN THE LOW TO MID 30S.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM...TAKING THE
LOW PRESSURE SYSTEM EAST ACROSS THE OHIO VALLEY DURING THE DAY...AND
ALLOWING THE ASSOCIATED SURFACE COLD FRONT TO MOVE THROUGH THE AREA
THIS AFTERNOON INTO EARLY THIS EVENING. MEANWHILE...THE MORE NORTHERN
SHORT WAVES WILL CONTINUE TO DROP SOUTHEAST IN SUCCESSION...HELPING
TO ESTABLISH A DEEP TROUGH ACROSS THE EAST BY FRIDAY.
THE CURRENT RADAR SHOWS A BAND OF LIGHT RAIN FROM SOUTH CENTRAL
INDIANA DOWN THROUGH WESTERN KENTUCKY. THE LATEST HRRR SHOWS THIS
ACTIVITY MAKING IT TO OUR DOORSTEP BY DAWN OR SHORTLY THEREAFTER...
ALTHOUGH THERE IS GOOD AGREEMENT THAT THE MAJORITY OF THE MEASURABLE
PRECIPITATION WILL STAY JUST NORTH...WITH MORE SPOTTIER ACTIVITY TO
CONTEND WITH ACROSS OUR AREA THROUGH 14Z. AFTER 14Z...PRECIPITATION
LOOKS TO BLOSSOM AS THE BETTER FORCING ARRIVES. HAVE BEEN CONCERNED
WITH THE COLD VALLEY READINGS ACROSS OUR AREA...HOWEVER IT LOOKS AS
THOUGH THAT BY THE TIME THE BETTER PRECIPITATION DOES MOVE IN...THAT
MOST LOCATIONS WILL BE ABOVE FREEZING. AS SUCH...WILL ISSUE A SPECIAL
WEATHER STATEMENT COVERING THE SPOTTIER PRECIPITATION AT ONSET...AS
MAINLY INTERIOR LOCATIONS WILL STILL LIKELY BE BELOW FREEZING. WILL
CONTINUE TO MONITOR TRENDS VERY CLOSELY OVER THE NEXT FEW HOURS SINCE
ANY RAMP UP IN THE PRECIPITATION WILL MEAN AN ICY COMMUTE POTENTIALLY.
ONCE THE FIRST BATCH OF PRECIP MOVES THROUGH LATER THIS MORNING INTO
EARLY THIS AFTERNOON...THERE WILL LIKELY BE A LULL IN THE
ACTIVITY...BEFORE THE COLDER AIR ARRIVES ON NORTHWEST WINDS AND THE
TROUGH AXIS MOVES THROUGH TONIGHT. THIS WILL ALLOW FOR SOME LIGHT
SNOW ACROSS THE AREA. SNOW SHOWERS WILL LIKELY LINGER IN THE EAST
THROUGH FRIDAY MORNING...BEFORE TAPERING OFF. ANY LIGHT ACCUMULATIONS
WILL FAVOR THE HIGHER TERRAIN IN THE FAR SOUTHEAST.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 446 AM EST THU JAN 29 2015
HIGH PRESSURE WILL TAKE HOLD OF SENSIBLE WEATHER TO BEGIN THIS
PERIOD. WHILE LOW PRESSURE THAT IS AFFECTING THE REGION TODAY
DEVELOPS INTO ANOTHER STRONG COASTAL LOW ACROSS THE NORTHEAST US.
THIS HIGH PRESSURE COUPLED WITH DECREASING CLOUDS WILL ALLOW FOR
DECOUPLING AND LOWS DROPPING DOWN INTO THE MID TO UPPER TEENS
AREA WIDE. THIS HIGH PRESSURE WILL ALLOW MOSTLY SUNNY SKIES EARLY IN
THE DAY FOR YOUR SATURDAY WITH INCREASING CLOUDS IN THE AFTERNOON.
WINDS WILL ALSO BECOME MORE SOUTHWEST BRINGING HIGHS ON SATURDAY INTO
THE UPPER 30S TO LOWER 40S.
NOW THE BIGGER CONCERN CONTINUES TO BE LATE WEEKEND STORM AND
CONFIDENCE REMAINS LOW IN REGARDS TO THIS SYSTEM. THE SETUP IS WE
HAVE A DEVELOPING UPPER LEVEL CLOSED LOW ACROSS THE NORTHERN BAJA
PENINSULA AND ASSOCIATED DEVELOPING SURFACE LOW SATURDAY MORNING.
MEANWHILE A UPPER LEVEL WAVE RIDES OVER RIDGING ACROSS THE NORTHWEST
US. THEN THIS IS WHERE THE MODELS CONTINUE TO STRUGGLE IS IN THE
PHASING PROCESS THAT OCCURS SATURDAY NIGHT IN THE UPPER LEVELS.
EARLIER THE 18Z/28 GFS AND 12Z/28 ECMWF HAD A MORE OPEN WAVE WHICH
TRANSLATED TO A WEAKER SURFACE LOW. THIS WAS NEW BASED ON THE
PREVIOUS RUNS SEEN OVER THE PAST COUPLE OF DAYS. THE LATEST 00Z/29
RUN OF THE GFS DEVELOPS A STRONGER LOW WITH A BIT OF A DEEPER TROUGH
SETTING UP. THE 00Z/29 ECMWF DOES HAVE SIMILARITIES...HOWEVER THE
SURFACE LOW PRESSURE IS NOT AS DEEP. ONE THING THAT REMAINS WITH BOTH
MODELS 00Z RUNS IS BOTH HAVE A GOOD AMT OF QPF RESPECTIVELY. ANOTHER
QUESTION THAT REMAINS IS HOW MUCH COLD AIR STAYS IN PLACE WITH THIS
SYSTEM ON SUNDAY AND THIS WILL DEPEND HEAVILY ON THE EVENTUAL TRACK
OF THIS SURFACE LOW. THAT SAID HAVE LEANED TOWARD A BIT COLDER
THROUGH THE DAY ON SUNDAY. THINKING STILL MUCH OF SUNDAY WOULD LEAD
TO MIXING ACROSS MUCH OF THE CWA WITH MORE IN THE WAY OF SNOW ACROSS
THE BLUEGRASS WHERE TEMPS REMAIN COOLER...HOWEVER CONFIDENCE IN THIS
SYSTEM REMAINS LOW GIVEN THE DRASTIC RUN TO RUN CHANGES SEEN IN THE
DETERMINISTIC MODELS. ALSO KEEPING IN MIND THAT THE ENSEMBLE MEAN HAS
BEEN QUITE ERRATIC AND GIVEN THAT THE 12 PERTURBATIONS IN OUR SYSTEM
ARE ERRATIC EXPLAINS THE LACK OF CONTINUITY. ALL THIS SAID STILL
THINK THERE IS A REASONABLE SHOT OF MEASURABLE SNOW SUNDAY INTO
MONDAY. ANOTHER PIECE TO THE PUZZLE TO KEEP IN MIND IS THAT A MORE
NORTHERLY TRACK SHOWN IN EARLIER RUNS COULD ALLOW FOR MORE SOUTHERLY
FLOW AND WARMER AIR AND LEAD TO LESSENING SNOWFALL TOTALS. ALTHOUGH
BEHIND THIS SYSTEM EXPECT COLD AIR TO FILTER INTO ALL OF THE CWA
SUNDAY NIGHT INTO MONDAY. ALSO WOULD EXPECT GENERALLY FALLING
TEMPERATURES DURING THE DAY ON MONDAY.
AFTER THIS THE AFOREMENTIONED LOW PRESSURE IS THEN FORECAST TO TRACK NE
AND CONTINUE TO DEEPEN ALONG NE ATLANTIC COAST. HIGH PRESSURE WILL
BUILD EAST MONDAY NIGHT AND EXPECT ANOTHER COLD NIGHT WITH GENERALLY
LOW TO MID TEENS ACROSS THE REGION. THESE TEMPS MAY HAVE TO BE
ADJUSTED FURTHER DEPENDING UPON IF WE RECEIVE MEASURABLE SNOW. THIS
HIGH PRESSURE WILL ADVANCE EAST OF THE REGION MOVING INTO THE DAY ON
TUESDAY BRINGING RETURN FLOW AND WELCOMING REBOUND IN
TEMPERATURE...WITH HIGHS IN THE MID TO UPPER 30S. THAT SAID WEDNESDAY
REMAINS UNCERTAIN WITH YET ANOTHER SYSTEM DEVELOPING AND AT THIS POINT
STUCK CLOSE TO THE BLEND. DID INTRODUCE MAINLY SLIGHT POPS DURING
THAT PORTION OF THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 211 PM EST THU JAN 29 2015
VFR PREVAILED AT THE START OF THE PERIOD...BUT LOW VFR CEILINGS WERE
PROGRESSING SE ACROSS THE REGION AFTER A PERIOD OF CLEARING. THE
CEILINGS ON THE WAY IN WILL GET PROGRESSIVELY LOWER WITH TIME. BY 00Z
MVFR CAN BE EXPECTED AREA WIDE...WITH IFR BEGINNING TO SHOW UP.
SCATTERED LIGHT RAIN SHOWERS WILL ALSO DEVELOP DURING THE AFTERNOON.
MOST AREAS WILL DEGRADE TO IFR TONIGHT...AND REMAINING RAIN SHOWERS
WILL CHANGE TO SNOW SHOWERS. THE SNOW SHOWERS WILL TAPER OFF AND
CEILINGS WILL START TO BREAK UP DURING THE DAY ON FRIDAY. WINDS WILL
GUST IN THE NEIGHBORHOOD OF 15-20 KTS THROUGH THE PERIOD...INITIALLY
FROM THE SW AND THEN SHIFTING TO THE WEST TONIGHT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...GEOGERIAN
LONG TERM...DJ
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
207 PM EST THU JAN 29 2015
.UPDATE...
ISSUED AT 1225 PM EST THU JAN 29 2015
MADE MULTIPLE UPDATES BASED ON OBS AND NEW 12Z NAM. THIS INCLUDES
RAISING TEMPS FOR TODAY AND ADJUSTING TEMPS FOR TONIGHT INTO FRIDAY.
HAVE ALSO ADJUSTED SKY COVER TO ACCOUNT FOR TEMPORARY CLEARING TAKING
PLACE TODAY. TIMED POPS BASED ON NEW 12Z NAM TO INCLUDE THE BREAK IN
PRECIP THAT IS CURRENTLY OCCURRING. ADJUSTED SNOW POTENTIAL BASED ON
-10C MOISTURE AVAILABILITY ALOFT FOR TONIGHT.
UPDATE ISSUED AT 1113 AM EST THU JAN 29 2015
WITH PRECIP ON THE WAY OUT AND NO MORE OBSERVED TEMPS AT OR BELOW
FREEZING IN VALLEYS AND READINGS CONTINUING TO WARM...HAVE ALLOWED
THE WSW TO EXPIRE. HAVE ISSUED ANOTHER SPS UNTIL EARLY AFTERNOON FOR
ANY LINGERING PREVIOUSLY EXISTING ICE.
UPDATE ISSUED AT 1013 AM EST THU JAN 29 2015
WITH REPORTS OF MANY ACCIDENTS...ISSUED A FREEZING RAIN ADVISORY FOR
LOCATIONS WHERE VALLEYS TEMPS ARE BELOW FREEZING AND PRECIP IS STILL
OCCURRING. TEMPS ARE WARMING...SO THE ADVISORY ONLY RUNS FOR ABOUT
ANOTHER HOUR. WILL EVALUATE TEMPS IN A WHILE TO SEE IF IT CAN EXPIRE.
UPDATE ISSUED AT 844 AM EST THU JAN 29 2015
PRECIP SHIELD HAS MADE IT INTO OUR WESTERN FORECAST AREA.
TEMPERATURES HAVE RESPONDED WELL WHERE MEASURABLE PRECIPITATION IS
FALLING...HOWEVER SOME VALLEYS IN THE EAST STILL LINGER IN THE MID
20S. LOOKING AT RADAR TRENDS...THE MEASURABLE PRECIPITATION SEEMS TO
BE HAVING A HARDER TIME COMING EAST WITH SOME DOWNSLOPE FLOW IN
PLACE...AND READINGS HAVE BEEN EDGING UP EVEN IN THE COLDER SPOTS
PRIOR TO THE PRECIP ARRIVING. HAVE BEEFED UP POPS TO CATEGORICAL
ACROSS THE BOARD...AND WILL CONTINUE TO MENTION A CHANCE OF FREEZING
RAIN...AS SOME SPOTTY SLICK SPOTS STILL LOOK POSSIBLE. UPDATES HAVE
BEEN SENT.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 400 AM EST THU JAN 29 2015
LATEST SURFACE MAP FEATURES HIGH PRESSURE ALONG THE EASTERN
CONUS...WITH LOW PRESSURE MOVING INTO THE GREAT LAKES AND OHIO VALLEY
REGIONS. ALOFT...A SHORT WAVE TROUGH IS ROTATING TOWARDS THE OHIO
VALLEY...WITH ANOTHER TROUGH DROPPING SOUTHEAST INTO THE NORTHERN
PLAINS...AND YET ONE MORE MOVING IN ACROSS SOUTH CENTRAL CANADA.
MAINLY MID AND HIGH LEVEL CLOUDS HAVE BEEN STREAMING IN ACROSS
EASTERN KENTUCKY. THE SOUTHERLY WIND FLOW OUT AHEAD OF THE
APPROACHING SURFACE LOW HAS ALLOWED FOR A NICE RIDGE/VALLEY SPLIT
ACROSS THE AREA...WITH MORE SHELTERED VALLEYS HOLDING IN THE LOW AND
MID 20S...WHILE RIDGE TOPS ARE IN THE LOW TO MID 30S.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM...TAKING THE
LOW PRESSURE SYSTEM EAST ACROSS THE OHIO VALLEY DURING THE DAY...AND
ALLOWING THE ASSOCIATED SURFACE COLD FRONT TO MOVE THROUGH THE AREA
THIS AFTERNOON INTO EARLY THIS EVENING. MEANWHILE...THE MORE NORTHERN
SHORT WAVES WILL CONTINUE TO DROP SOUTHEAST IN SUCCESSION...HELPING
TO ESTABLISH A DEEP TROUGH ACROSS THE EAST BY FRIDAY.
THE CURRENT RADAR SHOWS A BAND OF LIGHT RAIN FROM SOUTH CENTRAL
INDIANA DOWN THROUGH WESTERN KENTUCKY. THE LATEST HRRR SHOWS THIS
ACTIVITY MAKING IT TO OUR DOORSTEP BY DAWN OR SHORTLY THEREAFTER...
ALTHOUGH THERE IS GOOD AGREEMENT THAT THE MAJORITY OF THE MEASURABLE
PRECIPITATION WILL STAY JUST NORTH...WITH MORE SPOTTIER ACTIVITY TO
CONTEND WITH ACROSS OUR AREA THROUGH 14Z. AFTER 14Z...PRECIPITATION
LOOKS TO BLOSSOM AS THE BETTER FORCING ARRIVES. HAVE BEEN CONCERNED
WITH THE COLD VALLEY READINGS ACROSS OUR AREA...HOWEVER IT LOOKS AS
THOUGH THAT BY THE TIME THE BETTER PRECIPITATION DOES MOVE IN...THAT
MOST LOCATIONS WILL BE ABOVE FREEZING. AS SUCH...WILL ISSUE A SPECIAL
WEATHER STATEMENT COVERING THE SPOTTIER PRECIPITATION AT ONSET...AS
MAINLY INTERIOR LOCATIONS WILL STILL LIKELY BE BELOW FREEZING. WILL
CONTINUE TO MONITOR TRENDS VERY CLOSELY OVER THE NEXT FEW HOURS SINCE
ANY RAMP UP IN THE PRECIPITATION WILL MEAN AN ICY COMMUTE POTENTIALLY.
ONCE THE FIRST BATCH OF PRECIP MOVES THROUGH LATER THIS MORNING INTO
EARLY THIS AFTERNOON...THERE WILL LIKELY BE A LULL IN THE
ACTIVITY...BEFORE THE COLDER AIR ARRIVES ON NORTHWEST WINDS AND THE
TROUGH AXIS MOVES THROUGH TONIGHT. THIS WILL ALLOW FOR SOME LIGHT
SNOW ACROSS THE AREA. SNOW SHOWERS WILL LIKELY LINGER IN THE EAST
THROUGH FRIDAY MORNING...BEFORE TAPERING OFF. ANY LIGHT ACCUMULATIONS
WILL FAVOR THE HIGHER TERRAIN IN THE FAR SOUTHEAST.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 446 AM EST THU JAN 29 2015
HIGH PRESSURE WILL TAKE HOLD OF SENSIBLE WEATHER TO BEGIN THIS
PERIOD. WHILE LOW PRESSURE THAT IS AFFECTING THE REGION TODAY
DEVELOPS INTO ANOTHER STRONG COASTAL LOW ACROSS THE NORTHEAST US.
THIS HIGH PRESSURE COUPLED WITH DECREASING CLOUDS WILL ALLOW FOR
DECOUPLING AND LOWS DROPPING DOWN INTO THE MID TO UPPER TEENS
AREA WIDE. THIS HIGH PRESSURE WILL ALLOW MOSTLY SUNNY SKIES EARLY IN
THE DAY FOR YOUR SATURDAY WITH INCREASING CLOUDS IN THE AFTERNOON.
WINDS WILL ALSO BECOME MORE SOUTHWEST BRINGING HIGHS ON SATURDAY INTO
THE UPPER 30S TO LOWER 40S.
NOW THE BIGGER CONCERN CONTINUES TO BE LATE WEEKEND STORM AND
CONFIDENCE REMAINS LOW IN REGARDS TO THIS SYSTEM. THE SETUP IS WE
HAVE A DEVELOPING UPPER LEVEL CLOSED LOW ACROSS THE NORTHERN BAJA
PENINSULA AND ASSOCIATED DEVELOPING SURFACE LOW SATURDAY MORNING.
MEANWHILE A UPPER LEVEL WAVE RIDES OVER RIDGING ACROSS THE NORTHWEST
US. THEN THIS IS WHERE THE MODELS CONTINUE TO STRUGGLE IS IN THE
PHASING PROCESS THAT OCCURS SATURDAY NIGHT IN THE UPPER LEVELS.
EARLIER THE 18Z/28 GFS AND 12Z/28 ECMWF HAD A MORE OPEN WAVE WHICH
TRANSLATED TO A WEAKER SURFACE LOW. THIS WAS NEW BASED ON THE
PREVIOUS RUNS SEEN OVER THE PAST COUPLE OF DAYS. THE LATEST 00Z/29
RUN OF THE GFS DEVELOPS A STRONGER LOW WITH A BIT OF A DEEPER TROUGH
SETTING UP. THE 00Z/29 ECMWF DOES HAVE SIMILARITIES...HOWEVER THE
SURFACE LOW PRESSURE IS NOT AS DEEP. ONE THING THAT REMAINS WITH BOTH
MODELS 00Z RUNS IS BOTH HAVE A GOOD AMT OF QPF RESPECTIVELY. ANOTHER
QUESTION THAT REMAINS IS HOW MUCH COLD AIR STAYS IN PLACE WITH THIS
SYSTEM ON SUNDAY AND THIS WILL DEPEND HEAVILY ON THE EVENTUAL TRACK
OF THIS SURFACE LOW. THAT SAID HAVE LEANED TOWARD A BIT COLDER
THROUGH THE DAY ON SUNDAY. THINKING STILL MUCH OF SUNDAY WOULD LEAD
TO MIXING ACROSS MUCH OF THE CWA WITH MORE IN THE WAY OF SNOW ACROSS
THE BLUEGRASS WHERE TEMPS REMAIN COOLER...HOWEVER CONFIDENCE IN THIS
SYSTEM REMAINS LOW GIVEN THE DRASTIC RUN TO RUN CHANGES SEEN IN THE
DETERMINISTIC MODELS. ALSO KEEPING IN MIND THAT THE ENSEMBLE MEAN HAS
BEEN QUITE ERRATIC AND GIVEN THAT THE 12 PERTURBATIONS IN OUR SYSTEM
ARE ERRATIC EXPLAINS THE LACK OF CONTINUITY. ALL THIS SAID STILL
THINK THERE IS A REASONABLE SHOT OF MEASURABLE SNOW SUNDAY INTO
MONDAY. ANOTHER PIECE TO THE PUZZLE TO KEEP IN MIND IS THAT A MORE
NORTHERLY TRACK SHOWN IN EARLIER RUNS COULD ALLOW FOR MORE SOUTHERLY
FLOW AND WARMER AIR AND LEAD TO LESSENING SNOWFALL TOTALS. ALTHOUGH
BEHIND THIS SYSTEM EXPECT COLD AIR TO FILTER INTO ALL OF THE CWA
SUNDAY NIGHT INTO MONDAY. ALSO WOULD EXPECT GENERALLY FALLING
TEMPERATURES DURING THE DAY ON MONDAY.
AFTER THIS THE AFOREMENTIONED LOW PRESSURE IS THEN FORECAST TO TRACK NE
AND CONTINUE TO DEEPEN ALONG NE ATLANTIC COAST. HIGH PRESSURE WILL
BUILD EAST MONDAY NIGHT AND EXPECT ANOTHER COLD NIGHT WITH GENERALLY
LOW TO MID TEENS ACROSS THE REGION. THESE TEMPS MAY HAVE TO BE
ADJUSTED FURTHER DEPENDING UPON IF WE RECEIVE MEASURABLE SNOW. THIS
HIGH PRESSURE WILL ADVANCE EAST OF THE REGION MOVING INTO THE DAY ON
TUESDAY BRINGING RETURN FLOW AND WELCOMING REBOUND IN
TEMPERATURE...WITH HIGHS IN THE MID TO UPPER 30S. THAT SAID WEDNESDAY
REMAINS UNCERTAIN WITH YET ANOTHER SYSTEM DEVELOPING AND AT THIS POINT
STUCK CLOSE TO THE BLEND. DID INTRODUCE MAINLY SLIGHT POPS DURING
THAT PORTION OF THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 207 PM EST THU JAN 29 2015
VFR PREVAILED AT THE START OF THE PERIOD...BUT LOW VFR CEILINGS WERE
PROGRESSING SE ACROSS THE REGION AFTER A PERIOD OF CLEARING. THE
CEILINGS ON THE WAY IN WILL GET PROGRESSIVELY LOWER WITH TIME. BY 00Z
MVFR CAN BE EXPECTED AREA WIDE...WITH IFR BEGINNING TO SHOW UP.
SCATTERED LIGHT RAIN SHOWERS WILL ALSO DEVELOP DURING THE AFTERNOON.
MOST AREAS WILL DEGRADE TO IFR TONIGHT...AND REMAINING RAIN SHOWERS
WILL CHANGE TO SNOW SHOWERS. THE SNOW SHOWERS WILL TAPER OFF AND
CEILINGS WILL START TO BREAK UP DURING THE DAY ON FRIDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...GEOGERIAN
LONG TERM...DJ
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1137 AM CST Thu Jan 29 2015
.UPDATE...
Issued at 1137 AM CST THU JAN 29 2015
The AVIATION section has been updated for the 18Z TAF issuance.
UPDATE Issued at 905 AM CST THU JAN 29 2015
The forecast has been updated to catch up to the cloud and
temperature trends. Much of west Kentucky will have highs greater
than forecast late this morning. Also, the latest HRRR has no
precipitation over the area through the day, so removed all
measurable PoPs. Would not rule out some patchy drizzle across the
Evansville Tri State region this afternoon, but will add that in
once it becomes more obvious.
&&
.SHORT TERM (Today through Saturday)...
Issued at 255 AM CST Thu Jan 29 2015
A well-defined cold front will move quickly southeast across our
region this morning. A small line of showers developed well ahead
of the front from kowb to khop early this morning. Cannot rule out
another small line until the front passes to our east. For most of
the forecast area, this will be a dry frontal passage.
Behind the front, winds will shift into the northwest and become
rather gusty today. Some gusts around 25 knots are likely. NAM and
GFS 925 mb rh progs indicate widespread low cloudiness will arrive
behind the front and persist through the afternoon. Low level cold
advection and widespread cloudiness should result in a steady or
slowly falling temperature trend this afternoon. Highs will be in
the morning. A period of sunshine prior to the arrival of low
clouds could push temps up from their 08z readings in the mid 40s
to lower 50s.
The main forecast issue for tonight is when and if the low clouds
will clear out. 925 mb rh forecasts from the 00z nam and gfs are
quite moist all night, especially east of the Mississippi River.
The forecast will show partial clearing from west to east tonight,
but at a slower rate than previous forecasts. Lows will be in the
mid to upper 20s.
Friday still looks mostly sunny, although there may still be some
morning low clouds in southwest Indiana and northwest Kentucky.
Winds will decrease as surface high pressure reaches the mid and
upper Mississippi Valley. Highs should be quite cold considering
the amount of sun, ranging from the mid 30s to lower 40s.
Friday night and Saturday...mid and high clouds will gradually
increase ahead of the next system. The low levels will be
extremely dry, which should make it very difficult for precip to
reach the ground. Will keep in a slight chance of showers in the
Ozark foothills of southeast Missouri. Despite the clouds, highs
should be mainly in the lower and mid 40s due to southerly winds.
.LONG TERM (Saturday night through Wednesday)...
Issued at 300 AM CST Thu Jan 29 2015
Main forecast challenge in this time frame comes with the storm
system that looks to be impacting the region over the weekend,
especially Sunday. Forecast confidence remains fairly low at this
time regarding precip types.
As we begin the period, split mid/upper flow pattern should be in
place...with nrn branch trof digging se into the Plains and a nearly
stationary srn branch low in place over the Baja of CA. It now looks
as though the srn branch low will feed pacific moisture into the nrn
branch...leading to fairly widespread precip shield over the mid MS
River and Ohio Valleys Saturday night and esp Sunday as sfc low
pressure develops over the Gulf Coast states. As mentioned, the main
uncertainly at this time lies with precip type. The latest 00z runs
of the operational GFS and ECMWF are now in decent agreement that
the sfc low and inverted trof will remain farther south over
MS/AL...as a 1040 mb sfc high presses south into the nrn Plains.
This would result in a colder thermal profile than we were thinking
yesterday. Snow would be the main precip type over all except our
far southern counties, with some potential for a few inches, esp
along and north/west of the Ohio River. On the other hand for
example, 00Z NAM/GEM both bring the sfc low farther north, and are
thus much warmer in their thermal profiles. For this package, will
keep much of the nrn half of the forecast area mostly snow, and go
with rain/snow for now over much of wrn KY and se MO. Again,
uncertainty is still quite high and things are likely to change one
way or another as we get closer to the event.
Very cold air will follow in the wake of the system as Canadian high
pressure moves se into the region. Most locations will fall into the
teens later Sunday night and Monday night. Highs Monday will likely
remain below freezing. Of course, things could be even colder if any
areas manage to get a fresh layer of snow on the ground. The next
clipper system Tue/Tue night is expected to stay much farther north
and cross over the Great lakes region. May be some light precip as
it drags another cold front across the region, but most impacts with
this low are expected to remain north of the forecast area.
&&
.AVIATION...
Issued at 1137 AM CST THU JAN 29 2015
A large mass of MVFR ceilings is overspreading the region behind a
cold front late this morning. Given the expanse of the MVFR clouds
at this time, would not expect them to depart any time soon.
Definitely went on the pessimistic side of guidance with scattering
or lifting not until Friday morning. Northwest winds will continue
to gust well above 20kts this afternoon, but they should subside
some by sunset. Winds will remain around 10kts through the
remainder of the period.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...MY
LONG TERM....GM
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS JACKSON KY
1225 PM EST THU JAN 29 2015
.UPDATE...
ISSUED AT 1225 PM EST THU JAN 29 2015
MADE MULTIPLE UPDATES BASED ON OBS AND NEW 12Z NAM. THIS INCLUDES
RAISING TEMPS FOR TODAY AND ADJUSTING TEMPS FOR TONIGHT INTO FRIDAY.
HAVE ALSO ADJUSTED SKY COVER TO ACCOUNT FOR TEMPORARY CLEARING TAKING
PLACE TODAY. TIMED POPS BASED ON NEW 12Z NAM TO INCLUDE THE BREAK IN
PRECIP THAT IS CURRENTLY OCCURRING. ADJUSTED SNOW POTENTIAL BASED ON
-10C MOISTURE AVAILABILITY ALOFT FOR TONIGHT.
UPDATE ISSUED AT 1113 AM EST THU JAN 29 2015
WITH PRECIP ON THE WAY OUT AND NO MORE OBSERVED TEMPS AT OR BELOW
FREEZING IN VALLEYS AND READINGS CONTINUING TO WARM...HAVE ALLOWED
THE WSW TO EXPIRE. HAVE ISSUED ANOTHER SPS UNTIL EARLY AFTERNOON FOR
ANY LINGERING PREVIOUSLY EXISTING ICE.
UPDATE ISSUED AT 1013 AM EST THU JAN 29 2015
WITH REPORTS OF MANY ACCIDENTS...ISSUED A FREEZING RAIN ADVISORY FOR
LOCATIONS WHERE VALLEYS TEMPS ARE BELOW FREEZING AND PRECIP IS STILL
OCCURRING. TEMPS ARE WARMING...SO THE ADVISORY ONLY RUNS FOR ABOUT
ANOTHER HOUR. WILL EVALUATE TEMPS IN A WHILE TO SEE IF IT CAN EXPIRE.
UPDATE ISSUED AT 844 AM EST THU JAN 29 2015
PRECIP SHIELD HAS MADE IT INTO OUR WESTERN FORECAST AREA.
TEMPERATURES HAVE RESPONDED WELL WHERE MEASURABLE PRECIPITATION IS
FALLING...HOWEVER SOME VALLEYS IN THE EAST STILL LINGER IN THE MID
20S. LOOKING AT RADAR TRENDS...THE MEASURABLE PRECIPITATION SEEMS TO
BE HAVING A HARDER TIME COMING EAST WITH SOME DOWNSLOPE FLOW IN
PLACE...AND READINGS HAVE BEEN EDGING UP EVEN IN THE COLDER SPOTS
PRIOR TO THE PRECIP ARRIVING. HAVE BEEFED UP POPS TO CATEGORICAL
ACROSS THE BOARD...AND WILL CONTINUE TO MENTION A CHANCE OF FREEZING
RAIN...AS SOME SPOTTY SLICK SPOTS STILL LOOK POSSIBLE. UPDATES HAVE
BEEN SENT.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 400 AM EST THU JAN 29 2015
LATEST SURFACE MAP FEATURES HIGH PRESSURE ALONG THE EASTERN
CONUS...WITH LOW PRESSURE MOVING INTO THE GREAT LAKES AND OHIO VALLEY
REGIONS. ALOFT...A SHORT WAVE TROUGH IS ROTATING TOWARDS THE OHIO
VALLEY...WITH ANOTHER TROUGH DROPPING SOUTHEAST INTO THE NORTHERN
PLAINS...AND YET ONE MORE MOVING IN ACROSS SOUTH CENTRAL CANADA.
MAINLY MID AND HIGH LEVEL CLOUDS HAVE BEEN STREAMING IN ACROSS
EASTERN KENTUCKY. THE SOUTHERLY WIND FLOW OUT AHEAD OF THE
APPROACHING SURFACE LOW HAS ALLOWED FOR A NICE RIDGE/VALLEY SPLIT
ACROSS THE AREA...WITH MORE SHELTERED VALLEYS HOLDING IN THE LOW AND
MID 20S...WHILE RIDGETOPS ARE IN THE LOW TO MID 30S.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM...TAKING THE
LOW PRESSURE SYSTEM EAST ACROSS THE OHIO VALLEY DURING THE DAY...AND
ALLOWING THE ASSOCIATED SURFACE COLD FRONT TO MOVE THROUGH THE AREA
THIS AFTERNOON INTO EARLY THIS EVENING. MEANWHILE...THE MORE NORTHERN
SHORT WAVES WILL CONTINUE TO DROP SOUTHEAST IN SUCCESSION...HELPING
TO ESTABLISH A DEEP TROUGH ACROSS THE EAST BY FRIDAY.
THE CURRENT RADAR SHOWS A BAND OF LIGHT RAIN FROM SOUTH CENTRAL
INDIANA DOWN THROUGH WESTERN KENTUCKY. THE LATEST HRRR SHOWS THIS
ACTIVITY MAKING IT TO OUR DOORSTEP BY DAWN OR SHORTLY THEREAFTER...
ALTHOUGH THERE IS GOOD AGREEMENT THAT THE MAJORITY OF THE MEASURABLE
PRECIPITATION WILL STAY JUST NORTH...WITH MORE SPOTTIER ACTIVITY TO
CONTEND WITH ACROSS OUR AREA THROUGH 14Z. AFTER 14Z...PRECIPITATION
LOOKS TO BLOSSOM AS THE BETTER FORCING ARRIVES. HAVE BEEN CONCERNED
WITH THE COLD VALLEY READINGS ACROSS OUR AREA...HOWEVER IT LOOKS AS
THOUGH THAT BY THE TIME THE BETTER PRECIPITATION DOES MOVE IN...THAT
MOST LOCATIONS WILL BE ABOVE FREEZING. AS SUCH...WILL ISSUE A SPECIAL
WEATHER STATEMENT COVERING THE SPOTTIER PRECIPITATION AT ONSET...AS
MAINLY INTERIOR LOCATIONS WILL STILL LIKELY BE BELOW FREEZING. WILL
CONTINUE TO MONITOR TRENDS VERY CLOSELY OVER THE NEXT FEW HOURS SINCE
ANY RAMP UP IN THE PRECIPITATION WILL MEAN AN ICY COMMUTE POTENTIALLY.
ONCE THE FIRST BATCH OF PRECIP MOVES THROUGH LATER THIS MORNING INTO
EARLY THIS AFTERNOON...THERE WILL LIKELY BE A LULL IN THE
ACTIVITY...BEFORE THE COLDER AIR ARRIVES ON NORTHWEST WINDS AND THE
TROUGH AXIS MOVES THROUGH TONIGHT. THIS WILL ALLOW FOR SOME LIGHT
SNOW ACROSS THE AREA. SNOW SHOWERS WILL LIKELY LINGER IN THE EAST
THROUGH FRIDAY MORNING...BEFORE TAPERING OFF. ANY LIGHT ACCUMULATIONS
WILL FAVOR THE HIGHER TERRAIN IN THE FAR SOUTHEAST.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 446 AM EST THU JAN 29 2015
HIGH PRESSURE WILL TAKE HOLD OF SENSIBLE WEATHER TO BEGIN THIS
PERIOD. WHILE LOW PRESSURE THAT IS AFFECTING THE REGION TODAY
DEVELOPS INTO ANOTHER STRONG COASTAL LOW ACROSS THE NORTHEAST US.
THIS HIGH PRESSURE COUPLED WITH DECREASING CLOUDS WILL ALLOW FOR
DECOUPLING AND LOWS DROPPING DOWN INTO THE MID TO UPPER TEENS
AREA WIDE. THIS HIGH PRESSURE WILL ALLOW MOSTLY SUNNY SKIES EARLY IN
THE DAY FOR YOUR SATURDAY WITH INCREASING CLOUDS IN THE AFTERNOON.
WINDS WILL ALSO BECOME MORE SOUTHWEST BRINGING HIGHS ON SATURDAY INTO
THE UPPER 30S TO LOWER 40S.
NOW THE BIGGER CONCERN CONTINUES TO BE LATE WEEKEND STORM AND
CONFIDENCE REMAINS LOW IN REGARDS TO THIS SYSTEM. THE SETUP IS WE
HAVE A DEVELOPING UPPER LEVEL CLOSED LOW ACROSS THE NORTHERN BAJA
PENINSULA AND ASSOCIATED DEVELOPING SURFACE LOW SATURDAY MORNING.
MEANWHILE A UPPER LEVEL WAVE RIDES OVER RIDGING ACROSS THE NORTHWEST
US. THEN THIS IS WHERE THE MODELS CONTINUE TO STRUGGLE IS IN THE
PHASING PROCESS THAT OCCURS SATURDAY NIGHT IN THE UPPER LEVELS.
EARLIER THE 18Z/28 GFS AND 12Z/28 ECMWF HAD A MORE OPEN WAVE WHICH
TRANSLATED TO A WEAKER SURFACE LOW. THIS WAS NEW BASED ON THE
PREVIOUS RUNS SEEN OVER THE PAST COUPLE OF DAYS. THE LATEST 00Z/29
RUN OF THE GFS DEVELOPS A STRONGER LOW WITH A BIT OF A DEEPER TROUGH
SETTING UP. THE 00Z/29 ECMWF DOES HAVE SIMILARITIES...HOWEVER THE
SURFACE LOW PRESSURE IS NOT AS DEEP. ONE THING THAT REMAINS WITH BOTH
MODELS 00Z RUNS IS BOTH HAVE A GOOD AMT OF QPF RESPECTIVELY. ANOTHER
QUESTION THAT REMAINS IS HOW MUCH COLD AIR STAYS IN PLACE WITH THIS
SYSTEM ON SUNDAY AND THIS WILL DEPEND HEAVILY ON THE EVENTUAL TRACK
OF THIS SURFACE LOW. THAT SAID HAVE LEANED TOWARD A BIT COLDER
THROUGH THE DAY ON SUNDAY. THINKING STILL MUCH OF SUNDAY WOULD LEAD
TO MIXING ACROSS MUCH OF THE CWA WITH MORE IN THE WAY OF SNOW ACROSS
THE BLUEGRASS WHERE TEMPS REMAIN COOLER...HOWEVER CONFIDENCE IN THIS
SYSTEM REMAINS LOW GIVEN THE DRASTIC RUN TO RUN CHANGES SEEN IN THE
DETERMINISTIC MODELS. ALSO KEEPING IN MIND THAT THE ENSEMBLE MEAN HAS
BEEN QUITE ERRATIC AND GIVEN THAT THE 12 PERTURBATIONS IN OUR SYSTEM
ARE ERRATIC EXPLAINS THE LACK OF CONTINUITY. ALL THIS SAID STILL
THINK THERE IS A REASONABLE SHOT OF MEASURABLE SNOW SUNDAY INTO
MONDAY. ANOTHER PIECE TO THE PUZZLE TO KEEP IN MIND IS THAT A MORE
NORTHERLY TRACK SHOWN IN EARLIER RUNS COULD ALLOW FOR MORE SOUTHERLY
FLOW AND WARMER AIR AND LEAD TO LESSENING SNOWFALL TOTALS. ALTHOUGH
BEHIND THIS SYSTEM EXPECT COLD AIR TO FILTER INTO ALL OF THE CWA
SUNDAY NIGHT INTO MONDAY. ALSO WOULD EXPECT GENERALLY FALLING
TEMPERATURES DURING THE DAY ON MONDAY.
AFTER THIS THE AFOREMENTIONED LOW PRESSURE IS THEN FORECAST TO TRACK NE
AND CONTINUE TO DEEPEN ALONG NE ATLANTIC COAST. HIGH PRESSURE WILL
BUILD EAST MONDAY NIGHT AND EXPECT ANOTHER COLD NIGHT WITH GENERALLY
LOW TO MID TEENS ACROSS THE REGION. THESE TEMPS MAY HAVE TO BE
ADJUSTED FURTHER DEPENDING UPON IF WE RECEIVE MEASURABLE SNOW. THIS
HIGH PRESSURE WILL ADVANCE EAST OF THE REGION MOVING INTO THE DAY ON
TUESDAY BRINGING RETURN FLOW AND WELCOMING REBOUND IN
TEMPERATURE...WITH HIGHS IN THE MID TO UPPER 30S. THAT SAID WEDNESDAY
REMAINS UNCERTAIN WITH YET ANOTHER SYSTEM DEVELOPING AND AT THIS POINT
STUCK CLOSE TO THE BLEND. DID INTRODUCE MAINLY SLIGHT POPS DURING
THAT PORTION OF THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 844 AM EST THU JAN 29 2015
A PASSING COLD FRONT WILL BRING LOWERING CEILINGS...PRECIPITATION...
AND GUSTY SOUTH TO SOUTHWEST WINDS TO THE AREA THROUGH THIS EVENING.
VFR CONDITIONS WILL LIKELY HOLD ON THROUGH THE EARLY
AFTERNOON...BEFORE CEILINGS LIKELY COME DOWN QUICKLY TO MVFR/IFR ONCE
THE FRONT MOVES THROUGH THE AREA LATER THIS AFTERNOON INTO EARLY THIS
EVENING. PRECIPITATION WILL TAPER OFF THIS MORNING...AND THEN LOOKS
TO PICK UP AGAIN TONIGHT AS AN UPPER TROUGH AXIS MOVES ACROSS THE OHIO
AND TENNESSEE VALLEYS. COLDER AIR WILL MOVE IN ON NORTHWEST
WINDS...WITH RAIN CHANGING OVER TO SNOW. SOUTH TO SOUTHWEST WINDS OF
10 TO 15 KTS...WITH GUSTS IN THE 15 TO 20 KT RANGE WILL SHIFT TO THE
WEST AND EVENTUALLY NORTHWEST. THE WINDS WILL DIMINISH AND BECOME
LESS GUSTY AFTER DUSK.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...GEOGERIAN
LONG TERM...DJ
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS JACKSON KY
1113 AM EST THU JAN 29 2015
.UPDATE...
ISSUED AT 1113 AM EST THU JAN 29 2015
WITH PRECIP ON THE WAY OUT AND NO MORE OBSERVED TEMPS AT OR BELOW
FREEZING IN VALLEYS AND READINGS CONTINUING TO WARM...HAVE ALLOWED
THE WSW TO EXPIRE. HAVE ISSUED ANOTHER SPS UNTIL EARLY AFTERNOON FOR
ANY LINGERING PREVIOUSLY EXISTING ICE.
UPDATE ISSUED AT 1013 AM EST THU JAN 29 2015
WITH REPORTS OF MANY ACCIDENTS...ISSUED A FREEZING RAIN ADVISORY FOR
LOCATIONS WHERE VALLEYS TEMPS ARE BELOW FREEZING AND PRECIP IS STILL
OCCURRING. TEMPS ARE WARMING...SO THE ADVISORY ONLY RUNS FOR ABOUT
ANOTHER HOUR. WILL EVALUATE TEMPS IN A WHILE TO SEE IF IT CAN EXPIRE.
UPDATE ISSUED AT 844 AM EST THU JAN 29 2015
PRECIP SHIELD HAS MADE INTO OUR WESTERN FORECAST AREA. TEMPERATURES
HAVE RESPONDED WELL WHERE MEASURABLE PRECIPITATION IS
FALLING...HOWEVER SOME VALLEYS IN THE EAST STILL LINGER IN THE MID
20S. LOOKING AT RADAR TRENDS...THE MEASURABLE PRECIPITATION SEEMS TO
BE HAVING A HARDER TIME COMING EAST WITH SOME DOWNSLOPE FLOW IN
PLACE...AND READINGS HAVE BEEN EDGING UP EVEN IN THE COLDER SPOTS
PRIOR TO THE PRECIP ARRIVING. HAVE BEEFED UP POPS TO CATEGORICAL
ACROSS THE BOARD...AND WILL CONTINUE TO MENTION A CHANCE OF FREEZING
RAIN...AS SOME SPOTTY SLICK SPOTS STILL LOOK POSSIBLE. UPDATES HAVE
BEEN SENT.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 400 AM EST THU JAN 29 2015
LATEST SURFACE MAP FEATURES HIGH PRESSURE ALONG THE EASTERN
CONUS...WITH LOW PRESSURE MOVING INTO THE GREAT LAKES AND OHIO VALLEY
REGIONS. ALOFT...A SHORT WAVE TROUGH IS ROTATING TOWARDS THE OHIO
VALLEY...WITH ANOTHER TROUGH DROPPING SOUTHEAST INTO THE NORTHERN
PLAINS...AND YET ONE MORE MOVING IN ACROSS SOUTH CENTRAL CANADA.
MAINLY MID AND HIGH LEVEL CLOUDS HAVE BEEN STREAMING IN ACROSS
EASTERN KENTUCKY. THE SOUTHERLY WIND FLOW OUT AHEAD OF THE
APPROACHING SURFACE LOW HAS ALLOWED FOR A NICE RIDGE/VALLEY SPLIT
ACROSS THE AREA...WITH MORE SHELTERED VALLEYS HOLDING IN THE LOW AND
MID 20S...WHILE RIDGETOPS ARE IN THE LOW TO MID 30S.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM...TAKING THE
LOW PRESSURE SYSTEM EAST ACROSS THE OHIO VALLEY DURING THE DAY...AND
ALLOWING THE ASSOCIATED SURFACE COLD FRONT TO MOVE THROUGH THE AREA
THIS AFTERNOON INTO EARLY THIS EVENING. MEANWHILE...THE MORE NORTHERN
SHORT WAVES WILL CONTINUE TO DROP SOUTHEAST IN SUCCESSION...HELPING
TO ESTABLISH A DEEP TROUGH ACROSS THE EAST BY FRIDAY.
THE CURRENT RADAR SHOWS A BAND OF LIGHT RAIN FROM SOUTH CENTRAL
INDIANA DOWN THROUGH WESTERN KENTUCKY. THE LATEST HRRR SHOWS THIS
ACTIVITY MAKING IT TO OUR DOORSTEP BY DAWN OR SHORTLY THEREAFTER...
ALTHOUGH THERE IS GOOD AGREEMENT THAT THE MAJORITY OF THE MEASURABLE
PRECIPITATION WILL STAY JUST NORTH...WITH MORE SPOTTIER ACTIVITY TO
CONTEND WITH ACROSS OUR AREA THROUGH 14Z. AFTER 14Z...PRECIPITATION
LOOKS TO BLOSSOM AS THE BETTER FORCING ARRIVES. HAVE BEEN CONCERNED
WITH THE COLD VALLEY READINGS ACROSS OUR AREA...HOWEVER IT LOOKS AS
THOUGH THAT BY THE TIME THE BETTER PRECIPITATION DOES MOVE IN...THAT
MOST LOCATIONS WILL BE ABOVE FREEZING. AS SUCH...WILL ISSUE A SPECIAL
WEATHER STATEMENT COVERING THE SPOTTIER PRECIPITATION AT ONSET...AS
MAINLY INTERIOR LOCATIONS WILL STILL LIKELY BE BELOW FREEZING. WILL
CONTINUE TO MONITOR TRENDS VERY CLOSELY OVER THE NEXT FEW HOURS SINCE
ANY RAMP UP IN THE PRECIPITATION WILL MEAN AN ICY COMMUTE POTENTIALLY.
ONCE THE FIRST BATCH OF PRECIP MOVES THROUGH LATER THIS MORNING INTO
EARLY THIS AFTERNOON...THERE WILL LIKELY BE A LULL IN THE
ACTIVITY...BEFORE THE COLDER AIR ARRIVES ON NORTHWEST WINDS AND THE
TROUGH AXIS MOVES THROUGH TONIGHT. THIS WILL ALLOW FOR SOME LIGHT
SNOW ACROSS THE AREA. SNOW SHOWERS WILL LIKELY LINGER IN THE EAST
THROUGH FRIDAY MORNING...BEFORE TAPERING OFF. ANY LIGHT ACCUMULATIONS
WILL FAVOR THE HIGHER TERRAIN IN THE FAR SOUTHEAST.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 446 AM EST THU JAN 29 2015
HIGH PRESSURE WILL TAKE HOLD OF SENSIBLE WEATHER TO BEGIN THIS
PERIOD. WHILE LOW PRESSURE THAT IS AFFECTING THE REGION TODAY
DEVELOPS INTO ANOTHER STRONG COASTAL LOW ACROSS THE NORTHEAST US.
THIS HIGH PRESSURE COUPLED WITH DECREASING CLOUDS WILL ALLOW FOR
DECOUPLING AND LOWS DROPPING DOWN INTO THE MID TO UPPER TEENS
AREA WIDE. THIS HIGH PRESSURE WILL ALLOW MOSTLY SUNNY SKIES EARLY IN
THE DAY FOR YOUR SATURDAY WITH INCREASING CLOUDS IN THE AFTERNOON.
WINDS WILL ALSO BECOME MORE SOUTHWEST BRINGING HIGHS ON SATURDAY INTO
THE UPPER 30S TO LOWER 40S.
NOW THE BIGGER CONCERN CONTINUES TO BE LATE WEEKEND STORM AND
CONFIDENCE REMAINS LOW IN REGARDS TO THIS SYSTEM. THE SETUP IS WE
HAVE A DEVELOPING UPPER LEVEL CLOSED LOW ACROSS THE NORTHERN BAJA
PENINSULA AND ASSOCIATED DEVELOPING SURFACE LOW SATURDAY MORNING.
MEANWHILE A UPPER LEVEL WAVE RIDES OVER RIDGING ACROSS THE NORTHWEST
US. THEN THIS IS WHERE THE MODELS CONTINUE TO STRUGGLE IS IN THE
PHASING PROCESS THAT OCCURS SATURDAY NIGHT IN THE UPPER LEVELS.
EARLIER THE 18Z/28 GFS AND 12Z/28 ECMWF HAD A MORE OPEN WAVE WHICH
TRANSLATED TO A WEAKER SURFACE LOW. THIS WAS NEW BASED ON THE
PREVIOUS RUNS SEEN OVER THE PAST COUPLE OF DAYS. THE LATEST 00Z/29
RUN OF THE GFS DEVELOPS A STRONGER LOW WITH A BIT OF A DEEPER TROUGH
SETTING UP. THE 00Z/29 ECMWF DOES HAVE SIMILARITIES...HOWEVER THE
SURFACE LOW PRESSURE IS NOT AS DEEP. ONE THING THAT REMAINS WITH BOTH
MODELS 00Z RUNS IS BOTH HAVE A GOOD AMT OF QPF RESPECTIVELY. ANOTHER
QUESTION THAT REMAINS IS HOW MUCH COLD AIR STAYS IN PLACE WITH THIS
SYSTEM ON SUNDAY AND THIS WILL DEPEND HEAVILY ON THE EVENTUAL TRACK
OF THIS SURFACE LOW. THAT SAID HAVE LEANED TOWARD A BIT COLDER
THROUGH THE DAY ON SUNDAY. THINKING STILL MUCH OF SUNDAY WOULD LEAD
TO MIXING ACROSS MUCH OF THE CWA WITH MORE IN THE WAY OF SNOW ACROSS
THE BLUEGRASS WHERE TEMPS REMAIN COOLER...HOWEVER CONFIDENCE IN THIS
SYSTEM REMAINS LOW GIVEN THE DRASTIC RUN TO RUN CHANGES SEEN IN THE
DETERMINISTIC MODELS. ALSO KEEPING IN MIND THAT THE ENSEMBLE MEAN HAS
BEEN QUITE ERRATIC AND GIVEN THAT THE 12 PERTURBATIONS IN OUR SYSTEM
ARE ERRATIC EXPLAINS THE LACK OF CONTINUITY. ALL THIS SAID STILL
THINK THERE IS A REASONABLE SHOT OF MEASURABLE SNOW SUNDAY INTO
MONDAY. ANOTHER PIECE TO THE PUZZLE TO KEEP IN MIND IS THAT A MORE
NORTHERLY TRACK SHOWN IN EARLIER RUNS COULD ALLOW FOR MORE SOUTHERLY
FLOW AND WARMER AIR AND LEAD TO LESSENING SNOWFALL TOTALS. ALTHOUGH
BEHIND THIS SYSTEM EXPECT COLD AIR TO FILTER INTO ALL OF THE CWA
SUNDAY NIGHT INTO MONDAY. ALSO WOULD EXPECT GENERALLY FALLING
TEMPERATURES DURING THE DAY ON MONDAY.
AFTER THIS THE AFOREMENTIONED LOW PRESSURE IS THEN FORECAST TO TRACK NE
AND CONTINUE TO DEEPEN ALONG NE ATLANTIC COAST. HIGH PRESSURE WILL
BUILD EAST MONDAY NIGHT AND EXPECT ANOTHER COLD NIGHT WITH GENERALLY
LOW TO MID TEENS ACROSS THE REGION. THESE TEMPS MAY HAVE TO BE
ADJUSTED FURTHER DEPENDING UPON IF WE RECEIVE MEASURABLE SNOW. THIS
HIGH PRESSURE WILL ADVANCE EAST OF THE REGION MOVING INTO THE DAY ON
TUESDAY BRINGING RETURN FLOW AND WELCOMING REBOUND IN
TEMPERATURE...WITH HIGHS IN THE MID TO UPPER 30S. THAT SAID WEDNESDAY
REMAINS UNCERTAIN WITH YET ANOTHER SYSTEM DEVELOPING AND AT THIS POINT
STUCK CLOSE TO THE BLEND. DID INTRODUCE MAINLY SLIGHT POPS DURING
THAT PORTION OF THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 844 AM EST THU JAN 29 2015
A PASSING COLD FRONT WILL BRING LOWERING CEILINGS...PRECIPITATION...
AND GUSTY SOUTH TO SOUTHWEST WINDS TO THE AREA THROUGH THIS EVENING.
VFR CONDITIONS WILL LIKELY HOLD ON THROUGH THE EARLY
AFTERNOON...BEFORE CEILINGS LIKELY COME DOWN QUICKLY TO MVFR/IFR ONCE
THE FRONT MOVES THROUGH THE AREA LATER THIS AFTERNOON INTO EARLY THIS
EVENING. PRECIPITATION WILL TAPER OFF THIS MORNING...AND THEN LOOKS
TO PICK UP AGAIN TONIGHT AS AN UPPER TROUGH AXIS MOVES ACROSS THE OHIO
AND TENNESSEE VALLEYS. COLDER AIR WILL MOVE IN ON NORTHWEST
WINDS...WITH RAIN CHANGING OVER TO SNOW. SOUTH TO SOUTHWEST WINDS OF
10 TO 15 KTS...WITH GUSTS IN THE 15 TO 20 KT RANGE WILL SHIFT TO THE
WEST AND EVENTUALLY NORTHWEST. THE WINDS WILL DIMINISH AND BECOME
LESS GUSTY AFTER DUSK.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...GEOGERIAN
LONG TERM...DJ
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
357 PM EST THU JAN 29 2015
.SYNOPSIS...
A COLD FRONT WILL SWING THROUGH THE REGION TONIGHT. HIGH PRESSURE
BUILDING INTO THE REGION WILL BRING WINDY AND COLD CONDITIONS
FRIDAY AND FRIDAY NIGHT. THE HIGH WILL BUILD OVER THE AREA
SATURDAY...BUT LOW PRESSURE MAY IMPACT THE AREA LATER SUNDAY INTO
MONDAY. COLD HIGH PRESSURE WILL RETURN FOR THE MIDDLE PORTION OF
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
STILL HAVE SEVERAL MESONET OBS SHOWING 31/32 DEG F IN ANNE
ARUNDEL...PRINCE GEORGES COUNTIES. WITH PRECIP COMING IN FROM THE
WEST AND TEMPS NOT LIKELY TO MOVE ANY HIGHER /IN FACT GIVEN
DEWPOINTS THEY COULD DROP A DEGREE OR TWO/...HAVE OPTED TO EXPAND
EXISTING WINTER WEATHER ADVISORY EAST TO THE BAY TO INCLUDE MUCH
OF THE WASHINGTON METRO AREA FOR A BRIEF PERIOD OF SLEET MIXED
WITH POCKETS OF FREEZING RAIN OCCURRING DURING THE EVENING RUSH HOUR.
PREV...
A WINTRY MIX OF FREEZING RAIN...SLEET AND SNOW IS EXPECTED FOR MUCH
OF THE OUTLOOK AREA THIS AFTERNOON AND EARLY EVENING AND THEREFORE A
A WINTER WEATHER ADVISORY IS IN EFFECT.
HIGH PRESSURE CONTINUES TO MOVE OFF THE CAROLINA COAST THIS
AFTERNOON AND SOUTHERLY FLOW HAS INCREASED ACROSS THE REGION. A COLD
FRONT IS DRAPED FROM LAKE ERIE TO OH/IN TO KY. AHEAD OF THE COLD
FRONT AND IN RESPONSE TO A SHORTWAVE TROUGH AND WAA...PRECIPITATION
WILL CONTINUE TO MOVE ACROSS THE APPALACHIAN MTNS AND HIGHLANDS THIS
AFTERNOON. A NOSE OF +3 WARM AIR WILL CONTINUE TO MOVE INTO THE REGION AT
850MB. SOUTHERLY FLOW AT THE SFC HAS ALLOWED TEMPS TO CLIMB BUT COLD
SURFACES FROM RECENT COLD TEMPS AND SNOWPACK HAS SLOWED THEM FROM
CLIMBING MUCH. MANY OBS ARE AOB FREEZING AROUND WASHINGTON DC AND
BALTIMORE AND NORTH AND WEST ARE SUCH THAT. SOUTHERLY FLOW AT THE
SFC HAS MAINLY ALLOWED TEMPS IN VALLEYS IN CENTRAL
FOOTHILLS...PIEDMONT AND SOUTHERN MD TO RISE TO THE MID TO UPPER
30S. THIS TREND WILL CONTINUE AS BOUNDARY LAYER WINDS ARE EXPECTED
TO INCREASE TO 10-15KTS. THIS IS A BORDERLINE EVENT SINCE MANY ROAD
TEMPS ARE ABOVE FREEZING BUT MESONET OBS ARE NOT. EVEN THOUGH ASOS
AND AWOS SITES ARE WELL ABOVE FREEZING...MANY OBS BETWEEN THOSE
SITES ARE NOT. THEREFORE...PRECIPITATION MOVING EASTWARD MAY MELT
AND FREEZE ON CONTACT ESPECIALLY ON UNTREATED SURFACES. FURTHER
NORTH NEAR THE MD/PA BORDER...COLDER TEMPS ALOFT MAY LEAD TO MORE
SLEET AND SNOW THAN FZRA BUT ALL FROZEN PTYPES ARE POSSIBLE TODAY.
THEREFORE A WINTER WEATHER ADVISORY WAS ISSUED FOR THIS AFTERNOON
AND EVENING.
THE HRRR HAS BEEN FOLLOWING THE PRECIPITATION RATHER WELL THIS
MORNING. ANTICIPATE PRECIPITATION TO BE EAST OF THE WESTERN SHORE OF
THE CHESAPEAKE BAY BY 8PM. TEMPS SOUTH OF WASHINGTON DC ARE EXPECTED
TO BE ABOVE FREEZING AND THEREFORE RAIN AND SLEET ARE THE MAIN
PRECIP TYPES IN THIS REGION. THE FRONT WILL FOLLOW BEHIND AND MOVE ACROSS
THE MID-ATLANTIC TONIGHT REACHING THE CHESAPEAKE BAY BY LATE
TONIGHT. NW WINDS WILL MOVE IN BEHIND THE FRONT AND UPSLOPE SNOW
SHOWERS ARE EXPECTED ACROSS THE WESTERN SLOPES OF THE ALLEGHENY
FRONT. SNOW ACCUMULATION IS EXPECTED AS LAPSE RATES STEEPEN IN THE
SNOW GROWTH ZONE. A WINTER WEATHER ADVISORY CONTINUES FOR THE
WESTERN SLOPES FOR ACCUMULATING SNOW INTO FRIDAY. ACCUMULATION OF
4-8 INCHES ARE POSSIBLE IN THESE LOCATIONS.
VORTICITY ADVECTION WILL BE ROTATING AROUND THE MAIN TROUGH
TONIGHT AND TOMORROW. DRY WESTERLY WIND EAST OF THE ALLGHENY FRONT
SHOULD LIMIT PRECIP FROM REACHING THE GROUND. FCST MIN TEMPS WILL
REACH THE 20S IN THE MTNS AND LOW TO MID 30S FROM WASHINGTON DC AND
SOUTH AND EAST ALONG I-95.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
HIGH PRES BLDG INTO THE MID ATLC WL LEAD TO A STRNG PRES GRAD
ACROSS THE AREA. THIS IN TURN WL LEAD TO A WINDY DAY. BUFKIT
X-SXNS ARE SHOWING INXS OF 40 KT A FEW THOUSAND FT OFF THE GRND.
THIS WL HV THE PTNL TO BE BROUGHT TO THE SFC. WE ARE ADVSRTSG THE
PSBLTY OF A WIND ADVSRY - MOST LKLY AREAS WL BE ABV 1500 FT AND
ACROSS THE NRN 1/2 OF THE FCST AREA.
HIGHS IN THE LM30S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
HIGH PRES BLDG OVR THE RNG FRI NGT WL LEAD TO CHILLY TEMPS. LOWS
IN THE TEENS ACROSS MUCH OF THE AREA. WINDS WL BE DIMINISHING
OVRNGT...BUT W/ COLD TEMPS WINDS CHILLS XPCTD TO BE IN THE SINGLE
DIGITS E OF THE MTNS. PRSNTLY SEEING VALUES AS LOW AS -14 IN THE
HIGHLANDS. IF THIS TREND CONTS A WIND CHILL ADVSRY WL BE NEEDED
FOR OUR FAR WRN AREA.
SAT LOOKS TO BE M SUNNY BUT COLD W/ HIGHS RANGING FM THE U20S TO
THE MU30S OVR MOST OF THE AREA.
SAT NGT WL BE COLD...BUT A LTL WARMER THAN FRI NGT. NO WINDS SO
WIND CHILL WL NOT BE A CONCERN.
WHAT HAD BEEN A SPLIT IN THE MODELS BETWEEN A LOW TRACK TO OUR NORTH
AND ANOTHER TRACK TO OUR SOUTH SEEMS TO BE CONSOLIDATING AROUND THE
SOUTHERN TRACK NOW...TAKING IT EAST THRU S VA OR NC. THAT SUPPORTS
SNOW FOR MUCH IF NOT ALL OF OUR REGION. WOULD BE PASSING THRU AT A
GOOD CLIP BUT ACCUMULATING SNOW CERTAINLY A POSSIBILITY FOR SUN
AFTERNOON INTO MONDAY MORNING.
HIGH PRESSURE WILL FOLLOW FOR TUE. NEXT COLD FRONT POISED FOR
WEDNESDAY.
&&
.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
A WINTRY MIX IS EXPECTED THIS AFTERNOON AND EVENING FOR THE
TERMINALS. PRECIP WILL MOVE QUICK AND FROM WEST TO EAST THROUGH THE
REGION TODAY ENDING ACROSS BWI-MTN-DCA BY 8PM. MVFR CONDITIONS
POSSIBLE AT MRB-IAD-DCA-MTN-BWI AS COLDER AIR FURTHER NORTH GIVES A
GREATER POTENTIAL FOR SNPL. FURTHER SOUTH..CHO SHOULD STAY RAPL. S
WINDS 10-15KTS WILL CONTINUE TODAY AND TONIGHT AHEAD OF A COLD
FRONT. A STRONG FROPA IS EXPECTED TONIGHT WITH NW WINDS 20-25KTS G
35-40 EXPECTED LATE TONIGHT AND FRIDAY ACROSS THE TERMINALS.
WINDY CONDS FRI AND FRI NGT AS HIGH PRES BLDS INTO THE AREA. NO
PROBS XPCTD AVIATION-WISE SAT OR SAT NGT.
SNOW AND IFR CONDITIONS ARE POSSIBLE SUNDAY AFTERNOON INTO MONDAY
MORNING AS LOW PRESSURE SLIDES BY TO OUR SOUTH. VFR FOR TUESDAY.
&&
.MARINE...
A WINTRY MIX WILL MOVE ACROSS THE WATERS THIS EVENING. A MIX OF SNOW
SLEET AND RAIN ARE POSSIBLE BUT SHOULD END BY LATE TONIGHT.
SOUTHERLY WINDS WILL CONTINUE ON THE WATERS THROUGH TONIGHT BEFORE A
STRONG FROPA MOVES ACROSS THE WATERS BY FRIDAY MORNING. NW WINDS
20-25KT GUST AROUND 45KTS POSSIBLE. SCA ARE IN EFFECT AND WILL
TRANSITION TO A GALE WARNING FRIDAY.
A GALE WRNG IS IN EFFECT FM FRI MRNG THRU THE ERLY HRS OF SAT
MRNG..AND THEN AN SCA WL LKLY GO INTO EFFECT AFTRWARDS FOR THE
RMNDR OF THE NGT. WINDS WL BE DIMINISHING FOR SAT AND SAT NGT.
GUSTY WINDS AND A SMALL CRAFT ADVISORY ARE POSSIBLE ON MONDAY INTO
MONDAY NIGHT AS LOW PRESSURE INTENSIFIES OFFSHORE.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER WEATHER ADVISORY UNTIL 9 PM EST THIS EVENING FOR DCZ001.
MD...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR MDZ003-
502.
WINTER WEATHER ADVISORY UNTIL 9 PM EST THIS EVENING FOR
MDZ004>006-011-013-014-503>508.
WINTER WEATHER ADVISORY UNTIL NOON EST FRIDAY FOR MDZ501.
VA...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR VAZ027-
028-030-031-504.
WINTER WEATHER ADVISORY UNTIL 9 PM EST THIS EVENING FOR
VAZ052>054-501-505-506.
WINTER WEATHER ADVISORY UNTIL NOON EST FRIDAY FOR VAZ503.
WV...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
WVZ050>053-055-502-504-506.
WINTER WEATHER ADVISORY UNTIL NOON EST FRIDAY FOR WVZ501-503-
505.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530>534-
537>543.
GALE WARNING FROM 6 AM FRIDAY TO 1 AM EST SATURDAY FOR
ANZ530>543.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ535-
536.
&&
$$
BPP/HAS/WOODY!/CAS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
252 PM EST THU JAN 29 2015
.SYNOPSIS...
A COLD FRONT WILL SWING THROUGH THE REGION TONIGHT. HIGH PRESSURE
BUILDING INTO THE REGION WILL BRING WINDY AND COLD CONDITIONS
FRIDAY AND FRIDAY NIGHT. THE HIGH WILL BUILD OVER THE AREA
SATURDAY...BUT LOW PRESSURE MAY IMPACT THE AREA LATER SUNDAY INTO
MONDAY. COLD HIGH PRESSURE WILL RETURN FOR THE MIDDLE PORTION OF
NEXT WEEK.
&&
.NEAR TERM /TONIGHT/...
A WINTRY MIX OF FREEZING RAIN...SLEET AND SNOW IS EXPECTED FOR MUCH
OF THE OUTLOOK AREA THIS AFTERNOON AND EARLY EVENING AND THEREFORE A
A WINTER WEATHER ADVISORY IS IN EFFECT.
HIGH PRESSURE CONTINUES TO MOVE OFF THE CAROLINA COAST THIS
AFTERNOON AND SOUTHERLY FLOW HAS INCREASED ACROSS THE REGION. A COLD
FRONT IS DRAPED FROM LAKE ERIE TO OH/IN TO KY. AHEAD OF THE COLD
FRONT AND IN RESPONSE TO A SHORTWAVE TROUGH AND WAA...PRECIPITATION
WILL CONTINUE TO MOVE ACROSS THE APPALACHIAN MTNS AND HIGHLANDS THIS
AFTERNOON. A NOSE OF +3 WARM AIR WILL CONTINUE TO MOVE INTO THE REGION AT
850MB. SOUTHERLY FLOW AT THE SFC HAS ALLOWED TEMPS TO CLIMB BUT COLD
SURFACES FROM RECENT COLD TEMPS AND SNOWPACK HAS SLOWED THEM FROM
CLIMBING MUCH. MANY OBS ARE AOB FREEZING AROUND WASHINGTON DC AND
BALTIMORE AND NORTH AND WEST ARE SUCH THAT. SOUTHERLY FLOW AT THE
SFC HAS MAINLY ALLOWED TEMPS IN VALLEYS IN CENTRAL
FOOTHILLS...PIEDMONT AND SOUTHERN MD TO RISE TO THE MID TO UPPER
30S. THIS TREND WILL CONTINUE AS BOUNDARY LAYER WINDS ARE EXPECTED
TO INCREASE TO 10-15KTS. THIS IS A BORDERLINE EVENT SINCE MANY ROAD
TEMPS ARE ABOVE FREEZING BUT MESONET OBS ARE NOT. EVEN THOUGH ASOS
AND AWOS SITES ARE WELL ABOVE FREEZING...MANY OBS BETWEEN THOSE
SITES ARE NOT. THEREFORE...PRECIPITATION MOVING EASTWARD MAY MELT
AND FREEZE ON CONTACT ESPECIALLY ON UNTREATED SURFACES. FURTHER
NORTH NEAR THE MD/PA BORDER...COLDER TEMPS ALOFT MAY LEAD TO MORE
SLEET AND SNOW THAN FZRA BUT ALL FROZEN PTYPES ARE POSSIBLE TODAY.
THEREFORE A WINTER WEATHER ADVISORY WAS ISSUED FOR THIS AFTERNOON
AND EVENING.
THE HRRR HAS BEEN FOLLOWING THE PRECIPITATION RATHER WELL THIS
MORNING. ANTICIPATE PRECIPITATION TO BE EAST OF THE WESTERN SHORE OF
THE CHESAPEAKE BAY BY 8PM. TEMPS SOUTH OF WASHINGTON DC ARE EXPECTED
TO BE ABOVE FREEZING AND THEREFORE RAIN AND SLEET ARE THE MAIN
PRECIP TYPES IN THIS REGION. THE FRONT WILL FOLLOW BEHIND AND MOVE ACROSS
THE MID-ATLANTIC TONIGHT REACHING THE CHESAPEAKE BAY BY LATE
TONIGHT. NW WINDS WILL MOVE IN BEHIND THE FRONT AND UPSLOPE SNOW
SHOWERS ARE EXPECTED ACROSS THE WESTERN SLOPES OF THE ALLEGHENY
FRONT. SNOW ACCUMULATION IS EXPECTED AS LAPSE RATES STEEPEN IN THE
SNOW GROWTH ZONE. A WINTER WEATHER ADVISORY CONTINUES FOR THE
WESTERN SLOPES FOR ACCUMULATING SNOW INTO FRIDAY. ACCUMULATION OF
4-8 INCHES ARE POSSIBLE IN THESE LOCATIONS.
VORTICITY ADVECTION WILL BE ROTATING AROUND THE MAIN TROUGH
TONIGHT AND TOMORROW. DRY WESTERLY WIND EAST OF THE ALLGHENY FRONT
SHOULD LIMIT PRECIP FROM REACHING THE GROUND. FCST MIN TEMPS WILL
REACH THE 20S IN THE MTNS AND LOW TO MID 30S FROM WASHINGTON DC AND
SOUTH AND EAST ALONG I-95.
&&
.SHORT TERM /FRIDAY/...
HIGH PRES BLDG INTO THE MID ATLC WL LEAD TO A STRNG PRES GRAD
ACROSS THE AREA. THIS IN TURN WL LEAD TO A WINDY DAY. BUFKIT
X-SXNS ARE SHOWING INXS OF 40 KT A FEW THOUSAND FT OFF THE GRND.
THIS WL HV THE PTNL TO BE BROUGHT TO THE SFC. WE ARE ADVSRTSG THE
PSBLTY OF A WIND ADVSRY - MOST LKLY AREAS WL BE ABV 1500 FT AND
ACROSS THE NRN 1/2 OF THE FCST AREA.
HIGHS IN THE LM30S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRES BLDG OVR THE RNG FRI NGT WL LEAD TO CHILLY TEMPS. LOWS
IN THE TEENS ACROSS MUCH OF THE AREA. WINDS WL BE DIMINISHING
OVRNGT...BUT W/ COLD TEMPS WINDS CHILLS XPCTD TO BE IN THE SINGLE
DIGITS E OF THE MTNS. PRSNTLY SEEING VALUES AS LOW AS -14 IN THE
HIGHLANDS. IF THIS TREND CONTS A WIND CHILL ADVSRY WL BE NEEDED
FOR OUR FAR WRN AREA.
SAT LOOKS TO BE M SUNNY BUT COLD W/ HIGHS RANGING FM THE U20S TO
THE MU30S OVR MOST OF THE AREA.
SAT NGT WL BE COLD...BUT A LTL WARMER THAN FRI NGT. NO WINDS SO
WIND CHILL WL NOT BE A CONCERN.
WHAT HAD BEEN A SPLIT IN THE MODELS BETWEEN A LOW TRACK TO OUR NORTH
AND ANOTHER TRACK TO OUR SOUTH SEEMS TO BE CONSOLIDATING AROUND THE
SOUTHERN TRACK NOW...TAKING IT EAST THRU S VA OR NC. THAT SUPPORTS
SNOW FOR MUCH IF NOT ALL OF OUR REGION. WOULD BE PASSING THRU AT A
GOOD CLIP BUT ACCUMULATING SNOW CERTAINLY A POSSIBILITY FOR SUN
AFTERNOON INTO MONDAY MORNING.
HIGH PRESSURE WILL FOLLOW FOR TUE. NEXT COLD FRONT POISED FOR
WEDNESDAY.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
A WINTRY MIX IS EXPECTED THIS AFTERNOON AND EVENING FOR THE
TERMINALS. PRECIP WILL MOVE QUICK AND FROM WEST TO EAST THROUGH THE
REGION TODAY ENDING ACROSS BWI-MTN-DCA BY 8PM. MVFR CONDITIONS
POSSIBLE AT MRB-IAD-DCA-MTN-BWI AS COLDER AIR FURTHER NORTH GIVES A
GREATER POTENTIAL FOR SNPL. FURTHER SOUTH..CHO SHOULD STAY RAPL. S
WINDS 10-15KTS WILL CONTINUE TODAY AND TONIGHT AHEAD OF A COLD
FRONT. A STRONG FROPA IS EXPECTED TONIGHT WITH NW WINDS 20-25KTS G
35-40 EXPECTED LATE TONIGHT AND FRIDAY ACROSS THE TERMINALS.
WINDY CONDS FRI AND FRI NGT AS HIGH PRES BLDS INTO THE AREA. NO
PROBS XPCTD AVIATION-WISE SAT OR SAT NGT.
SNOW AND IFR CONDITIONS ARE POSSIBLE SUNDAY AFTERNOON INTO MONDAY
MORNING AS LOW PRESSURE SLIDES BY TO OUR SOUTH. VFR FOR TUESDAY.
&&
.MARINE...
A WINTRY MIX WILL MOVE ACROSS THE WATERS THIS EVENING. A MIX OF SNOW
SLEET AND RAIN ARE POSSIBLE BUT SHOULD END BY LATE TONIGHT.
SOUTHERLY WINDS WILL CONTINUE ON THE WATERS THROUGH TONIGHT BEFORE A
STRONG FROPA MOVES ACROSS THE WATERS BY FRIDAY MORNING. NW WINDS
20-25KT GUST AROUND 45KTS POSSIBLE. SCA ARE IN EFFECT AND WILL
TRANSITION TO A GALE WARNING FRIDAY.
A GALE WRNG IS IN EFFECT FM FRI MRNG THRU THE ERLY HRS OF SAT
MRNG..AND THEN AN SCA WL LKLY GO INTO EFFECT AFTRWARDS FOR THE
RMNDR OF THE NGT. WINDS WL BE DIMINISHING FOR SAT AND SAT NGT.
GUSTY WINDS AND A SMALL CRAFT ADVISORY ARE POSSIBLE ON MONDAY INTO
MONDAY NIGHT AS LOW PRESSURE INTENSIFIES OFFSHORE.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...WINTER WEATHER ADVISORY UNTIL NOON EST FRIDAY FOR MDZ501.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR MDZ003-
502.
WINTER WEATHER ADVISORY UNTIL 9 PM EST THIS EVENING FOR
MDZ004>006-011-503>508.
VA...WINTER WEATHER ADVISORY UNTIL NOON EST FRIDAY FOR VAZ503.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR VAZ027-
028-030-031-504.
WINTER WEATHER ADVISORY UNTIL 9 PM EST THIS EVENING FOR VAZ052-
053-501-505-506.
WV...WINTER WEATHER ADVISORY UNTIL NOON EST FRIDAY FOR WVZ501-503-
505.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
WVZ050>053-055-502-504-506.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530>534-
537>543.
GALE WARNING FROM 6 AM FRIDAY TO 1 AM EST SATURDAY FOR
ANZ530>543.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ535-
536.
&&
$$
PRODUCTS...HAS/WOODY!/CAS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1259 PM EST THU JAN 29 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 457 AM EST THU JAN 29 2015
WV AND LATEST RADAR IMAGERY SHOW IT WELL...THE DEEP MOISTURE SET UP
ACROSS CENTRAL UPPER MI IS QUICKLY EXITING E. THE SFC TROUGH SET UP
OVER W LAKE SUPERIOR AROUND 09Z THIS MORNING WILL EDGE TO THE E HALF
OF THE CWA SHORTLY AFTER DAYBREAK THIS IS WHEN WE WILL REALLY BEGIN
TO NOTICE SOME OF THOSE STRONGER N-NNW WINDS BEGIN /WINDS CURRENTLY
AROUND 12KTS AT CMX WILL BEGIN TO GUSTS 25-30KTS/.
-FZDZ HAS BEEN REPORTED OFF AND ON THIS MORNING AS THE MAIN BULK OF
MOISTURE EXISTS OVER CENTRAL AND E UPPER MI...AS STRONG HIGH
PRESSURE OVER CENTRAL SASKATCHEWAN NEARS. UTILIZED THE PROBABILITY
OF ICE PRESENT FROM THE RUC TO GET A BETTER HANDLE ON WHEN AND WHERE
-FZDZ MAY SET UP BEFORE COLD AIR PUSHES ACROSS ALL OF UPPER MI
/BASICALLY BY 18Z/ FOR ANY LINGERING MIXED PRECIP TO TRANSITION BACK
TO JUST -SHSN. LOOK FOR FALLING TEMPS THIS AFTERNOON AS THE COLDER
AIR SLIDES IN. 850MB TEMPS AROUND -10C EARLY THIS MORNING WILL FALL
THIS AFTERNOON...AND GET DOWN TO AROUND -17C BY 00Z...AND -20C BY
06Z FRIDAY. THE ARRIVAL OF THE COLDER AIR WILL BRING A BETTER CHANCE
OF LAKE EFFECT SNOW SHOWERS TO UPSLOPE LOCATIONS OVER THE W FAVORED
BY NNW WINDS.
LIMITING FACTORS FOR SIGNIFICANT SNOW ACCUMULATIONS OVER THE W THIRD
OF THE CWA LATER THIS AFTERNOON THROUGH THIS EVENING WILL BE THE
LOWERING DGZ TO AROUND 4KFT OR LESS BY 06Z FRIDAY...WINDS STILL
GUSTING 15-20KTS WILL KEEP SLR VALUES FROM RISING BACK UP TO
25:1 TOO FAST. HOWEVER...WITH THE 500MB TROUGH OVERHEAD AND AN
ADDITIONAL SHORTWAVE SLIDING THROUGH LATE THIS AFTERNOON THROUGH
THIS EVENING...SOME ENHANCEMENT IS EXPECTED. WILL KEEP SNOW AMOUNTS
AROUND 2IN OR LESS ACROSS THE W THIRD OF THE CWA.
ONE CONCERN FOR THE EVENING PERIOD WILL BE THE POTENTIAL OF A MESO
LOW SETTING UP OVER S CENTRAL LAKE SUPERIOR AFTER 03Z...KEEPING A
BAND OF MORE MODERATE SNOW OVER CENTRAL/E MARQUETTE COUNTY
AND W ALGER COUNTY. THE NAM AND REGIONAL WRF HIGHLIGHT THE
POTENTIAL. HAVE EXPANDED SNOW FARTHER W TO ACCOUNT FOR THIS...AS
WELL AS KEPT THE WINDS UP OVER S CENTRAL LAKE SUPERIOR A BIT LONGER
/WHICH SEEMS TO HAVE BEEN ALREADY ACCOUNTED FOR/. ENHANCED BY THE
WINDS GUSTING 25-35KTS...VISIBILITY RESTRICTIONS WILL BE A CONCERN
FOR THOSE TRAVELING ON M-28. EVEN WITHOUT ANY LAKE ENHANCEMENT
BLOWING AND DRIFTING SNOW COULD BE AN ISSUE...DEPENDING ON HOW SOLID
SNOW BANKS ON THE SIDE OF THE ROAD HAVE BECOME AND HOW MUCH SNOW HAS
BEEN ABLE TO ACCUMULATE ON THE ICE ALONG LAKE SUPERIOR.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 411 AM EST THU JAN 29 2015
FCST FOCUS IN THE MEDIUM AND EXTENDED RANGE WL BE ON THE IMPACT OF
SEVERAL CLIPPER TYPE SHRTWVS THAT ARE FCST TO MOVE THRU A MEAN UPR
TROF IN ERN NAMERICA. UNDER THE PERSISTENT NW FLOW ALOFT...EXPECT
BLO TO WELL BLO NORMAL TEMPS TO DOMINATE DURING THIS TIME WITH A
STEADY FEED OF CNDN AIR. WITH THE COLD AIR SURGES...LES WL BE AN
OBVIOUS CONCERN.
FRI...SFC HI PRES IS FCST TO SHIFT FM OVER MN TOWARD THE OH RIVER
VALLEY BE 00Z SAT. AS NW WINDS IN THE MRNG BACK TO THE W AND THEN
THE SW LATE...LINGERING LES OVER THE W WL BECOME CONFINED TO OVER
THE KEWEENAW AND END OVER THE E EXCEPT NEAR THE SHORE E OF GRAND
MARAIS TOWARD 00Z SAT. ALTHOUGH THE LK CLDS WL BE SHIFTING
OFFSHORE...MORE MID/HI CLDS IN ADVANCE OF ANOTHER SHRTWV MOVING SE
WITHIN THE NW FLOW ALF WL BE PUSHING INTO THE UPR LKS.
FRI NGT/SAT...SHRTWV EMBEDDED IN THE NW FLOW ALOFT WL BE MOVING INTO
NW MN AT 00Z SAT AND IS THEN FCST TO SLIDE SE THRU NCENTRAL WI BY
12Z SAT AND THEN ACROSS LOWER MI ON SAT. AT THE SAME TIME...ANOTHER
STRONGER SHRTWV WL BE MOVNG FM CENTRAL CANADA INTO FAR NW ONTARIO BY
12Z SAT BEFORE MOVING TO JUST S OF JAMES BAY BY 00Z SUN. UPR MI WL
BE IMPACTED MAINLY BY THE WEAKER SRN DISTURBANCE. ALTHOUGH A BAND OF
RELATIVELY WEAK QVECTOR CNVGC IS FCST TO SLIDE ACROSS UPR MI ON FRI
NGT INTO SAT MRNG ON THE CYC SIDE OF THIS SRN SHRTWV...ACCOMPANYING
ISENTROPIC ASCENT/MSTR INFLOW IS FCST TO BE RELATIVELY WEAK. SO WL
FCST ONLY CHC POPS OVER MOST OF THE CWA AND MAINLY BTWN 03Z SAT AND
15-18Z SAT...WHEN THE FORCING ACCOMPANYING THE SRN SHRTWV AND A COLD
FNT ATTENDANT TO THE NRN SHRTWV ARE FCST TO EXIT THE ERN CWA AND
GIVE WAY TO SOME VIGOROUS DEEP LYR QVECTOR DVGC. MAINTAINED SOME
LIKELY POPS OVER THE NRN TIER OF THE CWA CLOSE TO THE STRONGER NRN
SHRTWV AND WHERE SHARPER LLVL CNVGC WL ACCOMPANY THE SAT COLD FROPA.
THE COLDEST 00Z GFS/12Z ECMWF RUNS SHOW H85 TEMPS IN THE WAKE OF THE
SAT COLD FROPA PLUNGING AS LO AS -25C BY 00Z SUN...BUT QUICK
TRANSITION TO A MORE DIFFLUENT/ACYC H925 N FLOW AND INVRN BASE
FALLING TO H85-875 WL TEND TO LIMIT LES INTENSITY. RELATIVELY
MODERATE TEMPS INTO SAT MRNG WL FALL THRU THE AFTN AS THE COLDER AIR
SURGES INTO THE AREA IN THE STEADY N FLOW AHEAD OF ARCTIC HI PRES
BLDG SEWD IN SCENTRAL CANADA.
SAT NGT THRU SUN NGT...UPR MI WL REMAIN DOMINATED BY A COLD N
BACKING WNW LLVL FLOW OF ARCTIC AIR ASSOCIATED WITH ARCTIC HI PRES
MOVING FM OVER ALBERTA/SASKATCHEWAN AT 00Z SUN INTO THE UPR MS RIVER
VALLEY BY 12Z MON. EXPECT TEMPS TO RUN WELL BLO NORMAL AND LES TO
CONTINUE NEAR LK SUP WITH H85 TEMPS FCST TO REMAIN NOT FAR FM -22C
TO -25C. SAT NGT COULD BE PARTICULARLY CHILLY OVER THE E WITH THE N
H925 FLOW ALLOWING SOME DRAINAGE OF COLD AIR INTO THAT AREA OFF
ONTARIO. ALTHOUGH FCST ACYC NATURE OF THE H925 FLOW AND NEAR ABSENCE
OF THE DGZ ASSOCIATED WITH THE VERY LO H85 TEMPS WL LIMIT LES
AMOUNTS...SOME OF THE MODELS HINT THERE MAY BE SOME ENHANCED CNVGC
ALONG A LK INDUCED TROF STRETCHING FM THE KEWEENAW TOWARD WHITEFISH
PT THAT WL INTENSIFY AS THE LARGER PRES GRADIENT RELAXES AND A
SHRTWV EMBEDDED IN THE NW FLOW APRCHS ON SUN/SUN NGT. RAISED POPS
WELL ABOVE THE CONSENSUS TO LIKELY ALONG THIS AXIS.
MON...LES ALONG THE LK INDUCED TROF WL BEGIN TO DIMINISH/SHIFT OUT
INTO LK SUP WITH THE APRCH OF A SFC RDG AXIS EXTENDING N FM THE HI
CENTER SHIFTING TOWARD THE OH VALLEY AND THE ASSOCIATED BACKING LLVL
FLOW. BUT THE MORE W WIND COMPONENT WL MEAN LESS LK MODERATION AND
PERSISTENT WELL BLO NORMAL SFC TEMPS EVEN AS THE H85 TEMPS MODERATE
A BIT FASTER.
TUE/WED...THE LONGER RANGE GUIDANCE HINTS ANOTHER CLIPPER TYPE
DISTURBANCE WL PASS THRU THE UPR LKS ON TUE...WITH H85 TEMPS
REBOUNDING TO NEAR -15C IN THE WAA BTWN THIS FEATURE AND HI PRES
MOVING INTO THE MID ATLANTIC. BUT ANOTHER ARCTIC SURGE LOOKS TO
FOLLOW ON WED AS THE SHRTWV PASSAGE REAMPLIFIES THE ERN TROF AND THE
NW FLOW IN ADVANCE OF THE NEXT CNDN HI SINKING INTO THE NRN PLAINS
ADVECTS H85 TEMPS AS LO AS -25 TO -28C INTO THE UPR LKS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1258 PM EST THU JAN 29 2015
COLD FRONT IS EAST OF UPPER MICHIGAN AND BLUSTERY NORTHWEST WINDS OF
20-30 KTS IN GUSTS ARE ALREADY OCCURRING. EVENTUALLY THERE WILL BE A
SWITCH BACK TO MORE NUMEROUS LAKE EFFECT SNOW SHOWERS. OFF AND ON
ISOLD SNOW SHOWERS WILL AFFECT KIWD AND KCMX THIS AFTN WITH A WINDOW
FOR GREATER COVERAGE AND INTENSITY LATE THIS AFTN AS LIFT INCREASES
DUE TO AN UPPER LEVEL DISTURBANCE. SNOW SHOWERS WILL THEN DIMINISH
AGAIN BY LATE EVENING AS HIGH PRESSURE AND DRIER LOW-LEVEL AIR
ARRIVE FM THE NORTHWEST. AT KSAW...WILL HAVE TO CONTEND WITH MIX OF
SNOW AND FZDZ THIS AFTN BEFORE COLDER AIR SWITCHES THE PRECIP TO
LAKE EFFECT SNOW SHOWERS INTO THE EVENING. EXPECT DIMINISHING AND
ENDING TREND TO SNOW SHOWERS OVERNIGHT TONIGHT. WINDS WILL REMAIN
GUSTY AT ALL THE TAF SITES UNTIL LATER TONIGHT. VSBY MAINLY MVFR AT
ALL THE SITES THOUGH MAY DIP TO IFR BRIEFLY LATE THIS AFTN OR EARLY
EVENING. BY LATE TONIGHT INTO FRIDAY...MAINLY MVFR OR VFR FLYING
CONDITIONS ARE ANTICIPATED.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 AM EST THU JAN 29 2015
LOW PRESSURE SYSTEM NEAR N LAKE SUPERIOR THIS MORNING WILL MOVE INTO
QUEBEC THIS AFTERNOON WHILE ANOTHER LOW NEAR CHICAGO SHIFTS EAST
INTO NEW ENGLAND ON FRIDAY MORNING. MEANWHILE...A HIGH OVER S
CENTRAL CANADA WILL MOVE SE INTO MN ON FRIDAY. IN BETWEEN THE
EXITING LOW AND NEARING HIGH...STRONG N-NNW GALES GUSTING 35 TO
AROUND 40KTS WILL DEVELOP THIS AFTERNOON OVER MAINLY CENTRAL AND E
LAKE SUPERIOR. LOOK FOR WINDS TO SLOWLY DIMINISH LATE THIS EVENING
AND OVERNIGHT...WITH GUSTS REMAINING 25-30KTS THROUGH DAYBREAK
FRIDAY. GIVEN THE STRONG WINDS...AND COLDER AIR SURGING IN...HEAVY
FREEZING SPRAY WILL BE POSSIBLE OVER THIS SAME AREA INTO EARLY
FRIDAY MORNING. WINDS WILL THEN QUICKLY DIMINISH AND REMAIN LESS
THAN 30KTS THROUGH FRIDAY NIGHT.
AS THIS HIGH DRIFTS INTO THE OH RIVER VALLEY ON SATURDAY...A TROUGH
WILL SLIDE ACROSS THE UPPER GREAT LAKES. A FEW N TO NW GUSTS OF 30
TO NEAR 35KTS WILL BE POSSIBLE SATURDAY AFTERNOON AND EVENING.
EXPECT HIGH PRESSURE OVER CENTRAL CANADA ON SATURDAY TO MOVE SE INTO
THE N PLAINS ON SUNDAY...AND THE MID MS RIVER VALLEY ON MONDAY.
WINDS SHOULD DIMINISH FOR A TIME SUN BEFORE INCREASING AGAIN MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST FRIDAY FOR LSZ264-
266-267.
GALE WARNING UNTIL 4 AM EST FRIDAY FOR LSZ265>267.
GALE WARNING UNTIL 1 AM EST FRIDAY FOR LSZ263-264.
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST FRIDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KF
LONG TERM...KC
AVIATION...JLA
MARINE...KF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1216 PM CST THU JAN 29 2015
.UPDATED FOR 18Z AVIATION DISCUSSION...
ISSUED AT 1201 PM CST THU JAN 29 2015
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM CST THU JAN 29 2015
SHORT TERM CONCERNS ARE HEADLINES EARLY THIS MORNING. THEN OVERALL
IMPROVING TREND AND TURNING COLDER.
RADAR CONTINUES TO SHOW SOME LIGHT INTENSITY ECHOES MOVING ACROSS
EAST CENTRAL MN. WATER VAPOR IMAGERY SHOWING SECONDARY TROUGH
MOVING INTO WESTERN MN NOW. THE TREND ON THE RAP HAS BEEN
GENERATING SOME LIGHT QPF INTO SOUTH CENTRAL MN THROUGH ABOUT 14Z.
NOTHING TOO DRAMATIC ON RADAR...ALTHOUGH SURFACE OBS CONTINUE TO
SHOW SOME VISIBILITY REDUCTION IN BR AND OCCASIONALLY SOME -SN OR UP.
WILL CONTINUE THE FREEZING RAIN ADVISORY THROUGH 12Z. WILL WORD
THAT PRECIPITATION SHOULD BE ENDING THIS MORNING.
THE OTHER CONCERN IS THE WIND ADV TO THE SOUTHWEST. WINDS HAVE BEEN
INCREASING TO THE WEST OVERNIGHT AS THE PRESSURE GRADIENT INCREASES
WITH THE COLD FRONT MOVING THROUGH. THIS SHOULD CONTINUE THROUGH AT
LEAST MID MORNING AS THE GREATEST PRESSURE RISE MOVES THROUGH THE
AREA. HAVE INCLUDED A COUPLE MORE COUNTIES IN WEST CENTRAL MN AS
WELL.
WINDS ARE EXPECTED TO DIMINISH OVERALL AFTER 18Z AND BECOME LIGHT
INTO TONIGHT. CLOUDS WILL THIS AS WELL WITH TEMPERATURES DROPPING
THROUGH THE SINGLE DIGITS AND TEENS FOR LOWS TONIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 349 AM CST THU JAN 29 2015
WEST/NORTHWEST FLOW WILL PREVAIL THROUGH THE MAJORITY OF THE LONG
TERM FORECAST PERIOD...WITH ONLY MINOR/FLEETING CHANCES FOR
PRECIPITATION FORESEEN INTO EARLY NEXT WEEK.
FRIDAY WILL BE A TALE OF TWO STORIES WITHIN THE FORECAST AREA...AS
THE DEPARTING SURFACE HIGH YIELDS TEMPS AROUND 5 TO 10 DEGREES
BELOW NORMAL IN THE EAST OVER WISCONSIN...AND LOW LEVEL WARM AIR
ADVECTION OVER THE WEST BRINGS HIGHS FROM 5 TO 10 DEGREES ABOVE
NORMAL TO WEST CENTRAL AND SOUTHWESTERN MINNESOTA. EXPECT HIGH
TEMPS TO RANGE FROM 15 TO 20 DEGREES OVER WEST CENTRAL WI...TO THE
LOWER 30S ALONG THE MN RIVER VALLEY.
ON SATURDAY...THE GFS AND ECMWF MODELS ARE STICKING TO THEIR GUNS
IN PROGGING THE BULK OF THE PRECIPITATION TO PASS SOUTH OF THE
FORECAST AREA...AS AN INCOMING ARCTIC HIGH SUPPRESSES THE SYSTEM
LIFTING OUT OF THE SOUTHWESTERN CONUS. COULD SEE A LIGHT ROUND OF
SNOWFALL WITH INCH OR SO ACCUMULATIONS ON SATURDAY NIGHT AHEAD OF
THE APPROACHING HIGH...BUT THE MAIN /SOUTHERN STREAM/ SYSTEM
SHOULD STAY WELL SOUTH OF THE AREA.
THE ARCTIC HIGH WILL INEVITABLY BE ACCOMPANIED BY A NOTABLE
REDUCTION IN TEMPERATURES...WITH HIGHS FROM 5 TO 15 DEGREES ON
SUNDAY...AND SUB-ZERO LOWS OCCURRING NEARLY AREA-WIDE ON SUNDAY
NIGHT. ASSOCIATED WINDS WILL BE RATHER LIGHT...SO DO NOT CURRENTLY
EXPECT WIND CHILLS TO DIP LOWER THAN -15 TO -20 ON SUNDAY NIGHT
AND MONDAY MORNING.
AS THE HIGH SLIPS OFF TO THE SOUTHEAST...TEMPERATURES WILL
GRADUALLY MODERATE BACK TO NORMAL AS A SURFACE TROUGH APPROACHES
FROM THE NORTHERN ROCKIES. THIS FEATURE MAY BRING A LIGHT ROUND OF
SNOW ON MONDAY NIGHT INTO TUESDAY MORNING...DURING WHICH 20-30
POPS HAVE BEEN INCLUDED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1201 PM CST THU JAN 29 2015
MVFR CIGS WILL GRADUALLY THIN OUT LATER THIS AFTERNOON...WITH
CLEARING SKIES EXPECTED OVERNIGHT. NORTHWESTERLY WINDS WILL
DIMINISH TODAY AS WELL...BECOME LIGHT AND VARIABLE OVERNIGHT...AND
TAKE ON A SOUTHEASTERLY DIRECTION BY FRIDAY MORNING.
KMSP...
EXPECT A MIX OF VFR AND MVFR CONDITIONS BETWEEN 18-21Z TIMEFRAME.
BY EVEN CONDITIONS SHOULD BE VFR...WITH LIGHTER WINDS.
/OUTLOOK FOR KMSP/
SAT...VFR WITH MVFR CIGS/-SN POSSIBLE SAT NIGHT. WIND N AT 5-10KT.
SUN...VFR WITH MVFR CIGS POSSIBLE EARLY. WIND N AT 10 KT.
MON...VFR WITH MVFR/SN POSSIBLE LATE. WINDS S AT 10G15KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...DWE
LONG TERM...LS
AVIATION...JRB
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1132 AM CST THU JAN 29 2015
.UPDATE...
ISSUED AT 1132 AM CST THU JAN 29 2015
CLOUDS HAVE BEEN DIMINISHING IN COVERAGE ACROSS NORTH CENTRAL AND
CENTRAL NEBRASKA THROUGH THIS MORNING AS WARM AIR BUILDS IN ALOFT
AND THE BOUNDARY LAYER MIXES. THE CLOUDS KEPT TEMPERATURES FROM
DROPPING OVERNIGHT...AND WITH THE SUNSHINE ACROSS THE
WEST WARMING THOSE AREAS...TEMPERATURES ARE FAIRLY SIMILAR ACROSS
THE ENTIRE FORECAST AREA. MIXING TO 850MB CONTINUES TO LOOK LIKELY
THROUGH THE AFTERNOON AND WITH TEMPERATURES AT THAT LEVEL
INCREASING THE ONGOING FORECAST OF NEAR 40 TO MID 40S STILL LOOKS
GOOD.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 359 AM CST THU JAN 29 2015
SFC OBS INDICATE CEILINGS ARE RISING ACROSS
NCNTL NEB. THE CLOUDS ARE ASSOCIATED WITH COLD AIR ADVECTION WHICH
THE NAM AND RAP MODELS SHOW WEAKENING THIS MORNING 15Z-18Z. THUS WE
SHOULD SEE A CONTINUED EROSION OF THE CLOUD COVER WITH MOSTLY SUNNY
SKIES FROM 18Z ONWARD.
THE MODEL CONSENSUS SUGGESTS HIGHS IN THE 40S TODAY. THE TEMPERATURE
FORECAST IS CLOSE TO RAP MODEL WHICH GENERALLY WORKS WELL IN CLEAR
SKY CONDITIONS.
TONIGHT...HIGH PRESSURE WILL MOVE OFF SLOWLY EAST WITH SOUTH WINDS
DEVELOPING ACROSS THE PANHANDLE FROM 03Z ONWARD AND SPREADING SLOWLY
EAST OVERNIGHT. THE COLDEST READINGS SHOULD OCCUR ALONG AND EAST OF
HIGHWAY 83 WHERE WINDS WILL REMAIN LIGHT AND VARIABLE MOST OF THE
NIGHT.
WINDS TODAY SHOULD CONTINUE TO DECREASE FROM WEST TO EAST. THE RAP
MODEL INDICATES NORTH WINDS AT JUST 10 TO 15 MPH BY 3 PM THIS AFTN
AS PACIFIC HIGH PRESSURE BUILDS INTO WRN NEB.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 359 AM CST THU JAN 29 2015
A WEAKENING UPPER LEVEL RIDGE WILL TRANSLATE EAST ACROSS THE CENTRAL
PORTIONS OF THE UNITED STATES FRIDAY. MILD PACIFIC AIR WILL
ACCOMPANY THE RIDGING...WITH H850MB TEMPERATURES RANGING FROM
2C TO 4C ACROSS THE AREA. THE DAY WILL START SUNNY...BUT SOME
INCREASE IN HIGH CLOUDINESS EXPECTED BY LATER IN THE DAY AS SUB
TROPICAL MOISTURE BEGINS TO APPROACH THE AREA FROM THE SOUTHWEST.
WITH THE MILD AIR IN PLACE AND EXPECTED SUN...WILL RAISE HIGHS A FEW
DEGREES INTO THE MID 40S TO LOWER 50S.
STILL LOOKS INTERESTING FRIDAY NIGHT THROUGH SATURDAY NIGHT. A
LARGE PLUMB OF SUB TROPICAL MOISTURE...ORIGINATING OFF THE WEST
COAST OF MEXICO...WILL BE DRAWN NORTHWARD INTO THE SOUTHERN AND
POSSIBLY CENTRAL PLAINS AHEAD OF AN UPPER LEVEL TROUGH THAT WILL
MOVE INTO THE DESERT SOUTHWEST/WESTERN CONUS BY FRIDAY EVENING. AT
THE SAME TIME...A NORTHERN STREAM SHORTWAVE WILL BE MOVING INTO
BRITISH COLUMBIA FROM THE GULF OF ALASKA. MODELS HAVE BEEN
STRUGGLING WITH THE NORTHERN STREAM FEATURE...WITH SOME MODEL RUNS
STRONGER AND MORE AMPLIFIED WITH THE SHORTWAVE...AND OTHERS WEAKER
AND MORE SHEARED. THE LATEST 29/00Z RUN OF THE ECMWF SUPPORTS A
WEAKER...FASTER AND MORE SHEARED SHORTWAVE...WITH THE GFS A BIT
SLOWER AND MORE AMPLIFIED...AND THE NAM BEING THE MOST AMPLIFIED AND
SLOWEST OF ALL. HOW THE NORTHERN STREAM SYSTEM INTERACTS WITH THE
SUB TROPICAL MOISTURE REMAINS IN QUESTION. A SLOWER MORE AMPLIFIED
SCENARIO WOULD PULL MOISTURE FARTHER NORTH THOUGH THE FORECAST
AREA...WHILE A FASTER MORE SHEARED SCENARIO WOULD TEND TO SHUNT MUCH
OF THE SUB TROPICAL MOISTURE OFF TO THE EAST. THE SLOWER MORE
AMPLIFIED NAM WOULD FAVOR BETTER CHANCES FOR SNOW...WHILE THE GFS
AND ESPECIALLY THE ECMWF WOULD NOT. DUE TO THE WOBBLING OF THE
MODELS IN REGARDS TO THE NORTHERN STREAM...WILL ONLY MAKE SLIGHT
ADJUSTMENTS TO THE CURRENT POP FORECAST. WILL MAINTAIN THE LOW
CHANCE POPS ACROSS CENTRAL AND PORTIONS OF NORTH CENTRAL
NEBRASKA...WITH A DECREASE TO JUST SLIGHT CHANCES FARTHER WEST.
NORTHERN STREAM ENERGY IS QUITE DIFFICULT TO FORECAST...AND EXPECT
THAT MODELS WILL CONTINUE TO WOBBLE SOME UNTIL THE FEATURE IS
ONSHORE FRIDAY.
AS THE NORTHERN STREAM ENERGY PASSES...EXPECT A BATCH OF ARCTIC AIR
TO PUSH SOUTH INTO THE CENTRAL AND NORTHERN PLAINS IN IT/S WAKE
SUNDAY. UPPER FLOW QUICKLY BECOMES MORE ZONAL MONDAY...WITH PACIFIC
AIR SPREADING BACK INTO THE REGION FROM THE WEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1132 AM CST THU JAN 29 2015
VFR CONDITIONS WILL PERSIST THROUGH FRIDAY AFTERNOON AS MVFR
CEILINGS HAVE SCATTERED OUT BY LATE THIS MORNING. THE FORECAST
DOES HAVE A TREND SHOWING CHANGING WIND CONDITIONS AS THE CURRENT
BREEZY NORTHWEST WINDS DIMINISH NEAR MID AFTERNOON AS HIGH
PRESSURE BUILDS IN. NEAR SUNSET THE BOUNDARY LAYER WILL DECOUPLE
LEADING TO LIGHT WINDS WHICH WILL BE VARIABLE AND EVENTUALLY SHIFT
AROUND TO THE SOUTH OVERNIGHT. THE WINDS WILL INCREASE TO AROUND
12KTS LATE FRIDAY MORNING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BROOKS
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...BROOKS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1125 AM CST THU JAN 29 2015
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 312 AM CST THU JAN 29 2015
EXTENSIVE LOW CLOUD LAYER HAD OVERSPREAD EASTERN NEBRASKA AND
SOUTHWEST IOWA EARLY THIS MORNING. HRRR SUGGESTS CLOUDS WILL
LIKELY HANG TOUGH THROUGH THE MORNING BEFORE BREAKING UP FROM WEST
TO EAST DURING THE EARLY AFTERNOON. GUSTY NORTHWEST WINDS ALSO
EXPECTED TO CONTINUE INTO THE MORNING ALTHOUGH LATEST TREND
APPEARS TO BE A DECREASE FROM NORTH TO SOUTH THROUGH 12Z. WILL
ADD REMAINING SOUTHERN COUNTIES TO ADVISORY THROUGH EXPIRATION AT
7 AM. HIGH PRESSURE RIDGE THEN SETTLES OVER THE AREA TONIGHT
BEFORE MOVING EAST ON FRIDAY.
NEXT FORECAST CONCERN DEVELOPS FRIDAY NIGHT AND SATURDAY AS A COLD
FRONT MOVES INTO THE AREA FROM THE NORTH WHILE LOW LEVEL WARM
ADVECTION MOVES IN FROM THE SOUTH IN ADVANCE OF CLOSED UPPER LOW
OVER THE SOUTHWEST PART OF THE COUNTRY. LATEST MODEL SOLUTIONS
INDICATE AN AREA OF LIGHT PRECIP SPREADING INTO THE SOUTH HALF OF
THE FORECAST AREA BY SATURDAY MORNING THEN LINGERS THROUGH
SATURDAY NIGHT.
AT THIS TIME IT APPEARS NORTHERN PARTS OF THE AREA SHOULD STAY DRY
FOR THE MOST PART. DRIER AIR COMING IN WITH NEXT BATCH OF COLD AIR
LOOKS TO LIMIT NORTHERN EXTENT OF PRECIP WITH A SHARP CUTOFF
ACROSS EAST CENTRAL NEBRASKA AND WEST CENTRAL IOWA. PRECIP LIKELY
TO START OFF AS LIQUID ALONG THE SOUTHEAST BORDER AREA LATE FRIDAY
NIGHT THEN TRANSITION TO LIGHT SNOW DURING THE DAY SATURDAY AS THE
COLD AIR DEEPENS BEHIND THE FRONT. SOME LIGHT SNOW ACCUMULATION IN
THE 1 TO 2 INCH RANGE POSSIBLE BY SUNDAY MORNING ACROSS SOUTHEAST
NEBRASKA INTO SOUTHWEST IOWA WITH UPPER BOUND NEAR SOUTHERN BORDER
OF NEBRASKA AND SOUTHWEST IOWA.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 312 AM CST THU JAN 29 2015
MUCH COLDER AIR MOVES IN ON SUNDAY AS THE SOUTHERN PLAINS WEATHER
SYSTEM MOVES EAST AND HIGH PRESSURE BUILDS INTO THE CENTRAL
PLAINS. COLDEST AIR HANGS AROUND THROUGH MONDAY BEFORE SOME
MODERATION RETURNS AS ANOTHER CLIPPER MOVES INTO THE REGION MONDAY
NIGHT. MORE COLD AIR FOLLOWS BEHIND THE CLIPPER FOR TUESDAY INTO
WEDNESDAY ALONG WITH ANOTHER POTENTIAL FOR LIGHT SNOW AS
BAROCLINIC ZONE DEVELOPS IN THE AREA.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1117 AM CST THU JAN 29 2015
MVFR CONDITIONS ARE EXPECTED FOR THE FIRST FEW HOURS OF THE TAF
CYCLE. SKIES WILL CLEAR THIS AFTERNOON AND NORTHWEST SFC WINDS
WILL DIMINISH AND BECOME LIGHT AND VARIABLE OVERNIGHT. SOUTHWEST
SFC WINDS WILL THEN INCREASE FRIDAY MORNING.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...FOBERT
LONG TERM...FOBERT
AVIATION...KERN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
340 PM EST THU JAN 29 2015
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL SPREAD
ACCUMULATING SNOW ACROSS OUR REGION TONIGHT INTO FRIDAY.
TEMPERATURES WILL PLUMMET FRIDAY...WITH GUSTY WINDS SENDING WIND
CHILLS WELL BELOW ZERO FRIDAY NIGHT. COLD AIR WILL REMAIN INTO
NEXT WEEK.
&&
.NEAR TERM /THROUGH FRIDAY/...
SURFACE LOW IS MOVING INTO SOUTHERN ONTARIO WITH PRECIP SPREADING
EAST ACROSS NY. AT THIS POINT A LITTLE LIGHT SNOW IN THE CWA HAS
BEEN CONFINED MAINLY TO THE NORTHERN ZONES AS THERE IS A LOT OF
LOW LEVEL DRY AIR IN PLACE FARTHER SOUTH. HOWEVER MAIN BATCH OF
PRECIP NOW AROUND BUFFALO WILL MOVE EAST WITH LIGHT SNOW MOVING
INTO REMAINING AREAS OF THE CWA TOWARD THE LATE AFTERNOON / EARLY
EVENING TIME FRAME AS LOW LEVELS SATURATE.
EXPECT LIGHT SNOW TO CONTINUE THROUGH MOST OF THE NIGHT AS THE LOW MOVES
EAST WITH THE HEAVIEST AMOUNTS OVER NORTHERN PARTS OF THE CWA FROM
ONONDAGA EAST THROUGH ONEIDA COUNTIES...AS DYNAMICS WILL BE
STRONGEST HERE...AND THERE WILL ALSO BE ADDED OROGRAPHIC LIFT IN
THE TUG HILL PLATEAU REGION. NAM AND RAP SEEM TO BE HANDLING THIS
FAIRLY WELL SO LEANED FORECAST TOWARD THESE MODELS. THE LOW WILL
DRAG A COLD FRONT THROUGH LATE TONIGHT SHIFTING THE WINDS TO THE
NW AND STARTING THE LAKE EFFECT MACHINE. ARCTIC AIR RETURNS
QUICKLY FRIDAY UNDER AN UPPER LEVEL TROF WITH FALLING TEMPS
THROUGH THE DAY. MODERATE SW WINDS WILL SHIFT TO STRONGER NW WINDS
LATE TONIGHT AND CREATE DRIFTING AND BLOWING SNOW.
WITH A NW LL FLOW FRIDAY LAKE EFFECT FRIDAY WILL BE ACROSS THE USUAL
AREAS OF CENTRAL NY. CAA WILL INCREASE LAPSE RATES ESPECIALLY IN
THE AFTN. AT THE SAME TIME THE INVERSION AND DENDRITE ZONE LOWER.
MULTI BAND LES COULD BE BRIEFLY HEAVY.
A WINTER WEATHER ADVISORY REMAINS IN EFFECT FOR THE NRN THIRD OF THE CWA
FOR THE SYNOPTIC SNOW OF 2 TO 5 INCHES TONIGHT FOLLOWED BY
ANOTHER 1 TO 4 INCHES OF LES FRIDAY. IN ADDITION WIND GUSTS TO 35
WILL CAUSE BLOWING AND DRIFTING SNOW FRIDAY. FURTHER SOUTH, WE GENERALLY
EXPECT SNOW AMOUNTS THROUGH FRIDAY OF 1 TO 3 INCHES FROM NE PA
THROUGH THE SOUTHERN TIER OF NY.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
315 PM UPDATE... LINGERING MULTI-BAND LES ACRS CNY AND PA`S NRN
TIER FRI EVE...WILL SLOWLY DIMINISH OVERNIGHT...AS THE CAPPING
INVERSION LWRS. ANOTHER LOCALIZED 1-2" MAY ACCUMULATE FRI NGT OVER
THE HIGHER TERRAIN OF THE UPR SUSQ/FINGER LKS RGNS IN CNY.
VERY COLD WIND CHILL READINGS ARE DEFINITELY A CONCERN FRI
NGT...WITH SFC WINDS ONLY SLOWLY SUBSIDING...AND ACTUAL AIR TEMPS
DROPPING INTO THE 5 ABV TO 10 BLO RANGE. WE`LL CONTINUE TO
HIGHLIGHT THIS SITN IN THE HWO...CITING THE POTENTIAL FOR WC
ADVSYS OR WRNGS IN LATER FCST UPDATES.
OTHER THAN PERHAPS A FEW FLRYS ON SAT...THE DAY SHOULD BE LARGELY
DRY...WITH BRIEF RIDGING AT THE SFC AND SOME S/WV RIDGING ALOFT
ACRS THE FA.
SAT NGT INTO SUN MRNG...A WEAK NRN STREAM S/WV AND SFC FRNT WILL
PUSH SWD THROUGH CNY/NE PA...ACCOMPANIED BY FLRYS AND SCTD LGT
SNOW SHWRS (LTL OR NO ACCUMS).
BY LATER SUN AFTN...WE MAY SEE SOME STEADIER LGT SNOW APPROACH OUR
FAR SWRN ZNS...ON THE OUTER EDGES OF THE NEXT S/WV AND FAST MOVG
SFC WV. MORE ON THIS SYSTEM IN THE FOLLOWING SXN.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
330 PM UPDATE... MODEL DISAGREEMENT/INCONSISTENCY CONTS WITH THE
LATEST CYCLES REGARDING THE SUN NGT-MON STORM SYSTEM. THE MOST RECENT
RUNS OF THE EC/GFS HAVE TRENDED NWD SOMEWHAT AGN...NOW TRACKING
THE SFC LOW THROUGH VA AND SERN MD...AND BRINGING LGT SNOW AT
LEAST TO THE PA/NY BORDER...IF NOT INTO NY`S SRN TIER.
MEANWHILE...THE CAN GEM HAS NOW GONE MUCH FARTHER S...TAKING THE
SFC WV THROUGH THE CAROLINAS...WITH LTL OR NO SNOWFALL FOR OUR FA.
GIVEN ALL THE UNCERTAINTY...THE EXPECTATION OF FURTHER MODEL
WAFFLING...AND ALSO THE FACT THAT THE SUPPORTING S/WV ENERGY IS
NOW JUST APPROACHING THE PACIFIC COAST OF NORTH AMERICA...WE`LL
SIMPLY MAKE VERY SMALL INCREMENTAL CHGS ATTM...JUST EASING POPS
UPWARD AGN TO INCORPORATE THE LATEST EC/GFS TRENDS. THIS RESULTS
IN LIKELY POPS FOR OUR FAR SRN ZNS SUN NGT (BACK DOWN TO CHC BY
MON)...AND CHC POPS THROUGHOUT THIS PD FOR OUR NY SRN TIER CNTYS.
ALTHOUGH...STRICTLY SPEAKING...WE`RE CURRENTLY INDICATING THE
POTENTIAL FOR A FEW INCHES OF SNOW OVER PTNS OF NE PA...THIS WILL
CERTAINLY BE SUBJECT TO CHANGE OVER THE NEXT COUPLE OF DAYS. STAY
TUNED FOR THE LATEST UPDATES ON THIS SITN.
TUE INTO WED LOOK QUIETER...BUT VERY COLD...WITH ONLY SOME FLRYS
FORESEEN AT WORST.
BY WED NGT AND THU...OUR NEXT REINFORCING COLD FRNT AND NRN STREAM
S/WV APPROACH...BRINGING A CHC OF SNOW SHWRS. THE EC IS ALSO
SHOWING THE PSBLTY THAT SOME SRN STREAM MOISTURE GETS INCORPORATED
INTO THE SYSTEM. STILL PLENTY OF TIME TO SORT ALL OF THESE FINE
DETAILS OUT.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
UPDATED AT 1245 PM...VFR CONDITIONS WILL PREVAIL THRU THIS
AFTERNOON WITH INCREASING HIGH CLOUDS. A LOW PRESSURE SYSTEM WILL
MOVE ACROSS THE AREA LATE TODAY AND TONIGHT BRINGING PERIODS OF
LIGHT SNOW WITH OCCASIONAL IFR VSBYS AND CIGS AFTER 22Z. SURFACE
WINDS WILL GENERALLY BE SOUTH-SOUTHEAST 5 TO 15 KTS THIS
AFTERNOON INTO THIS EVENING. ALSO, A STRONG LOW LEVEL JET WILL
RESULT IN WIND SHEAR BECOMING AN ISSUE THIS AFTERNOON AND
PERSISTING INTO THIS EVENING AS WINDS NEAR 2000 FT WILL BE
INCREASING TO 40+ KNOTS.
FOR FRIDAY, EXPECT STRONG NW WINDS GUSTING 20 TO 30 KNOTS AND SNOW
SHOWERS ON THE BACKSIDE OF TODAY`S SYSTEM. CONDITIONS FRIDAY WILL GENERALLY
BE MVFR WITH OCCASIONAL IFR CEILINGS AND VISBYS POSSIBLE IN
HEAVIER SNOW SHOWERS...ESPECIALLY AROUND KSYR.
OUTLOOK...
FRI NGT...PSBL RESTRICTIONS (MVFR/IFR) IN SNOW SHWRS...SPCLY IN
THE EVE OVER NORTHERN AREAS
SAT...SAT NGT...AND MOST OF SUN...VFR.
SUN NGT MON...PSBL RESTRICTIONS (MVFR/IFR) IN SNOW.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...WINTER WEATHER ADVISORY UNTIL 5 PM EST FRIDAY FOR NYZ009-
016>018-036-037-044>046.
&&
$$
SYNOPSIS...PCF
NEAR TERM...PCF
SHORT TERM...MLJ
LONG TERM...MLJ
AVIATION...PCF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
ISSUED BY NATIONAL WEATHER SERVICE BLACKSBURG VA
1213 PM EST THU JAN 29 2015
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE THIS AFTERNOON AHEAD OF A COLD
FRONT THAT WILL CROSS THE AREA TONIGHT INTO FRIDAY MORNING. HIGH
PRESSURE WILL BUILD IN FROM THE WEST ON FRIDAY...WHICH WILL HELP
TO KEEP CONDITIONS DRY INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1027 AM THURSDAY...
15Z ANALYSIS SHOWS HIGH PRESSURE CONTINUING TO PUSH EAST OF US WHILE
THE COLD FRONT OVER THE OHIO VALLEY MOVES EAST. CLOUDS WILL
CONTINUE TO INCREASE ACROSS OUR AREA AS THIS PATTERN EVOLVES AND THE
COLD FRONT APPROACHES. MODELS STILL SUGGESTING A FEW RAIN SPRINKLES
OR LIGHT RAIN SHOWERS ARE POSSIBLE LATER TODAY IN ADVANCE OF THE
FRONT...WITH THE BEST CHANCES ACROSS OUR NORTHERN AND WESTERN ZONES.
LATEST HRRR SUGGESTS THE SLIGHT CHANCE POPS THIS AFTERNOON MAY NEED
TO BE EXPANDED A LITTER FURTHER EASTWARD ACROSS OUR AREA...BUT
EITHER WAY...ANY RAIN THAT OCCURS WILL BE VERY LIGHT WITH LOW
IMPACTS. OTHERWISE...NO SIGNIFICANT CHANGES WITH THE MORNING
UPDATE.
PREV DISCUSSION AS OF 230 AM...OPTIMAL RADIATIONAL COOLING FOR THE
NEXT COUPLE OF HOURS WHILE HIGH PRESSURE OVERHEAD CALMS WINDS AND
SKIES REMAIN CLEAR. THIS WONT LAST FOR TOO LONG HOWEVER AS HIGH
CLOUDS ARE BEGINNING TO MOVE IN FROM THE WEST ASSOCIATED WITH A
FRONTAL SYSTEM WITH PARENT MOVING INTO THE CHICAGO AREA AT THIS
TIME. THE ATTENDANT COLD FRONT...WHICH IS WEAK IS PROGGED TO CROSS
CENTRAL NC LATER TONIGHT AND INTO FRIDAY MORNING. UNTIL
THEN...SOUTHERLY RETURN FLOW WILL PICK UP ON THE BACK SIDE OF THE
SURFACE HIGH AFTER SUNRISE WITH SOME GUSTING AROUND 15 KTS
POSSIBLE...ESPECIALLY IN THE WEST WHICH IS FURTHER AWAY FROM THE
CENTER OF THE HIGH. USING DRY ADIABATIC METHODS OR LOW LEVEL
THICKNESSES SUGGEST TEMPERATURES IN THE MID TO UPPER 50S BUT WITH
THE INCREASING CLOUD COVER...ESPECIALLY DURING PEAK HEATING THESE
NUMBERS WILL BE CUT BACK TO THE UPPER 40S TO MID 50S. CANT RULE OUT
SOME HIGHER TEMPS IN THE SOUTHEAST...WHERE THE EFFECTS OF THE
APPROACHING SYSTEM WILL BE MOST DELAYED.
AS FAR AS PRECIPITATION CHANCES ARE CONCERNED WITH THE ACTUAL
FRONT...CONDITIONS ARE DRY BUT THE LATEST VERSION OF THE MODELS IS
NOT QUITE AS DRY AS YESTERDAY WITH PW VALUES INCREASING TO NEAR 0.7
INCHES AS OPPOSED TO 0.5 YESTERDAY. A FIRST LOOK AT HIGH RESOLUTION
CONVECTIVE MODELS ALSO SHOWS SOME VERY LIGHT PRECIPITATION IN THE
NORTHWEST PIEDMONT JUST AFTER 21Z AND FADING OUT AS IT HEADS
EASTWARD BEFORE PICKING UP AGAIN OFF THE COAST. FORECAST SOUNDINGS
SHOW A SIMILAR STORY WITH THE BEST SATURATION IN THE TRIAD WITH LESS
LIKELY CHANCES FOR RAIN SOUTH AND EAST. DESPITE BETTER CHANCES IN
THE TRIAD...SATURATION IN THE MODEL SOUNDINGS IS BRIEF AND CONFINED
TO THE 850-700 MB RANGE WITH A LOT OF DRY AIR
UNDERNEATH...SUGGESTIVE OF SPRINKLES OR VIRGA PERHAPS IF MOISTURE
CANT REACH THE SURFACE. THE RESULT IS STILL VERY INCONSEQUENTIAL AS
QPF AMOUNTS WOULD BE A COUPLE OF HUNDREDTHS OF AN INCH AT THE VERY
BEST BUT MORE LIKELY TRACE AMOUNTS OR NOTHING. BETTER UPPER LEVEL
DYNAMICS COME IN AFTER 00Z FRIDAY BUT THE SYSTEM JUST LOOKS TO DRY
TO SUSTAIN ANYTHING AT THAT TIME.
AFTER FRONTAL PASSAGE AROUND 6Z FRIDAY...WINDS WILL SHIFT BACK TO
NORTHWESTERLY AND COLD AIR ADVECTION WILL ONCE AGAIN ENSUE.
LINGERING CLOUD COVER BEHIND THE FRONT WILL KEEP LOWS WARMER...IN
THE LOW TO UPPER 30S NW TO SE. AS DRY AIR WORKS IN BEHIND THE
FRONT...CLOUDS MAY CLEAR OUT FOR THE LATE MORNING PERIOD...BUT THEN
WRAP AROUND MOISTURE ON THE BACK SIDE OF THE EXITING SYSTEM WILL
MOVE IN FROM THE NORTH AND CUT DOWN ON INSOLATION DURING PEAK
HEATING. THIS MAY CAUSE A TEMPERATURE GRADIENT FROM THE NORTH TO
SOUTH RESULTING IN HIGHS IN THE MID 40S TO LOW 50S. DRY CONDITIONS
ARE EXPECTED AND INCREASING WINDS OF 15-20 KTS SUSTAINED WITH GUSTS
OF UP TO 25 KTS COULD CAUSE SOME FIRE WEATHER CONCERNS ON FRIDAY
AFTERNOON. AT THIS TIME MIN RH VALUES WILL HOVER AROUND 30%. WINDS
WILL DIE OFF AFTER SUNSET AND COUPLED WITH CLEAR SKIES WILL CAUSE
OPTIMAL RADIATIONAL COOLING RESULTING IN LOW TEMPERATURES NEAR 20
DEGREES FRIDAY NIGHT INTO SATURDAY MORNING.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM THURSDAY...
SURFACE HIGH PRESSURE OVER THE TN VALLEY WILL BUILD SOUTHWARD ACROSS
THE AREA ON SATURDAY...SHIFTING SOUTH AND OFF THE SOUTHEAST COAST
SATURDAY NIGHT. ALOFT...WEAK SOUTHERN STREAM IMPULSES EMBEDDED IN
INCREASING ZONAL FLOW ALOFT LATE SATURDAY/SATURDAY NIGHT WILL YIELD
THICKENING CIRRUS LAYER THROUGH THE DAY WITH MOSTLY CLOUDY SKIES BY
SATURDAY NIGHT. HIGHS WILL REMAIN BELOW NORMAL...RANGING FROM LOWER
40S NORTH TO MID/UPPER 40S SOUTH. LOWS SATURDAY NIGHT IN THE LOWER
TO MID 30S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...
SUNDAY THROUGH MONDAY: MINOR MID-LEVEL IMPULSES EMANATING FROM THE
UPPER TROUGH/CLOSED LOW OVER THE SOUTHWEST US...WILL
INTERACT....POTENTIALLY PHASE WITH NORTHERN STREAM ENERGY DIVING
SEWD WITHIN THE BROADENING CONUS TROUGH. ASSOCIATED CYCLOGENESIS
WILL TRACK EASTWARD ACROSS THE LOWER MS VALLEY/MID-SOUTH ON
SUNDAY...CROSSING THE SOUTHERN APPALACHIANS SUNDAY EVENING AND THEN
OFF THE CAROLINA COAST BY MIDDAY MONDAY. DESPITE MODEL
DIFFERENCES IN THE AMPLITUDE OF THE NORTHERN STREAM
TROUGH...TIMING OF THE BETTER RAIN CHANCES INTO THE AREA ARE
SIMILAR...WITH RAIN CHANCES QUICKLY RAMPING UP LATE SUNDAY
AFTERNOON/EARLY EVENING...WITH CATEGORICAL POPS SUNDAY
NIGHT...CUTTING OFF FROM WEST TO EAST MORNING MONDAY AS THE MID-
LEVEL DRY SLOT SPREAD EAST. CURRENT MODELS PROJECT A SOLID
0.50-1.0" ACROSS THE AREA...WITH SOME HIGHER AMOUNTS POSSIBLE IF
THE MORE AMPLIFIED--WETTER GFS VERIFIES. NO P- TYPE CONCERNS.
HIGHS BOTH DAYS IN THE 40S NORTH TO AROUND 50 SOUTH. LOWS SUNDAY
NIGHT IN THE MID TO UPPER 30S NORTH TO LOWER-MID 40S SOUTH.
MONDAY NIGHT THROUGH WEDNESDAY: CONTINENTAL POLAR HIGH PRESSURE WILL
BUILD INTO THE AREA MONDAY NIGHT AND INTO TUESDAY IN THE WAKE OF THE
UPPER LEVEL TROUGH LIFTING OUT OF THE AREA. IF PROJECTED LOW-LEVEL
THICKNESSES VERIFY...STRONG CAA MONDAY NIGHT WILL SUPPORT LOWS
TUESDAY MORNING IN THE TEENS ACROSS MUCH OF THE AREA...WITH HIGHS
TUESDAY AFTERNOON STRUGGLING TO WARM INTO THE 40S.
MODEL SPREAD REMAINS HIGH WITH THE EASTWARD EJECTION OF THE
AFOREMENTIONED UPPER TROUGH/LOW OVER THE SOUTHWEST US. WHILE THE EC
SUGGEST THIS SYSTEM COULD BRING PRECIP CHANCES BACK INTO THE AREA
LATE TUESDAY NIGHT AND INTO WEDNESDAY...THE GFS AND CANADIAN
SUPPRESS THE SYSTEM WELL TO OUR SOUTH...MAINTAINING DRY CONDITIONS
THROUGH LATE WEEK. GIVEN THE UNCERTAINTY HAVE LIMITED POP TO
SLIGHT/SMALL CHANCE.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 1202 PM EST THURSDAY...
24 HOUR TAF PERIOD: BANDS OF HIGH AND MID CLOUDS WILL CONTINUE TO
SWEEP EAST THIS AFTERNOON AHEAD OF AN APPROACHING COLD FRONT JUST
WEST OF THE MOUNTAINS. CEILINGS MAY LOWER BELOW 8K FEET ACROSS
THE WESTERN SITES LATE THIS AFTERNOON AS A DEEPER BAND OF MOISTURE
SWINGS EAST AND WEAKENS. THUS WILL CONTINUE MEDIUM TO HIGH
CONFIDENCE OF VFR CONDITIONS THROUGH THE TAF PERIOD AS THIS FRONT
SLIDES ACROSS THE FROM THE WEST TONIGHT. THERE IS A SLIGHT CHANCE
THAT CEILINGS COULD APPROACH MVFR LEVELS BETWEEN 03Z-08Z/10PM-3AM
BUT IFFY AND MAINLY WEST OF KRDU AT THIS POINT. SOUTH TO SOUTHWEST
WINDS MAY ALSO GUST TO BETWEEN 15-20 KTS THIS AFTERNOON BEFORE
RELAXING AGAIN AFTER SUNSET. MAYBE A SPRINKLE OR LIGHT SHOWER IN
THE TRIAD AHEAD OF THE FRONT DURING THE LATE AFTERNOON/EARLY
EVENING TIMEFRAME.
THE PASSING COLD FRONT WILL BRING A SHIFT IN WINDS TO THE
WEST/NORTHWEST AFTER MIDNIGHT FOLLOWED BY GUSTY NORTHWEST WINDS
FOR MUCH OF THE DAY ON FRIDAY. APPEARS SUSTAINED NORTHWEST WINDS
OF 15-22 KNOTS LIKELY WITH GUSTS TO 25-30 KNOTS OR PERHAPS HIGHER
NEAR THE END OF THE VALID TAF PERIOD.
LONG TERM: SUB-VFR CONDITIONS WILL BE POSSIBLE WITH A LOW PRESSURE
SYSTEM THAT WILL CROSS THE AREA LATE SUNDAY INTO MONDAY. VFR
CONDITIONS WILL PREVAIL ON TUESDAY AS HIGH PRESSURE BUILDS EAST
BEHIND THIS SYSTEM.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JH/ELLIS
NEAR TERM...-/ELLIS
SHORT TERM...CBL
LONG TERM...CBL
AVIATION...JH/ELLIS
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
532 PM EST THU JAN 29 2015
.SYNOPSIS...
AN ALBERTA CLIPPER/ARCTIC COLD FRONT WILL CROSS THE AREA TONIGHT.
HIGH PRESSURE WILL RETURN FOR LATE FRIDAY INTO SATURDAY. A NEW
STORM IS EXPECTED TO PASS WELL SOUTH OF THE AREA LATER SUNDAY
INTO MONDAY...FOLLOWED BY ANOTHER SURGE OF COLD AIR FOR EARLY
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
POTENT LOOKING SHORTWAVE IN WATER VAPOR LOOP WORKING INTO WESTERN
PA THIS EVENING. WAA ALONG AXIS OF SOUTHERLY LL JET PRODUCING SNOW
ACROSS MUCH OF CENTRAL PA AS OF 22Z. HOWEVER...WARMER AIR ALOFT
HAS WORKED INTO THE LAUREL HIGHLANDS...TURNING PRECIP TO FZRA FROM
S CLEARFIELD COUNTY SOUTHWARD.
FOR MOST OF CENTRAL PA...EXPECT OCNL LGT SNOW TO CONTINUE THRU
LATE EVENING...AS UPPER LVL SHORTWAVE ROLLS THRU. OVR THE S TIER
COUNTIES...LATEST HRRR AND 4KM NAM SOUNDINGS CONTINUE TO INDICATE
ENOUGH WARMING ALOFT FOR SOME LGT FREEZING RAIN OVERNIGHT.
NEAR TERM MDL DATA TIMES THE BACK EDGE OF THE DEEP MOISTURE/SIG
PRECIP INTO THE LAUREL HIGHLANDS ARND 03Z AND THE EASTERN
COUNTIES BY ARND 06Z.
HAVE DECIDED TO COVER THE THREAT FOR ICY CONDITIONS WITH A
WINT WEATHER ADVISORY OVER MY SOUTHERN TIER. OVERALL REASONING
HAS NOT CHANGED WITH JUST ENOUGH WARM AIR ALOFT EXPECTED TO CAUSE
A PERIOD OF NUISANCE-TYPE ICING.
HAVE TWEAKED SNOWFALL TOTALS IN OUR GRIDDED FORECASTS...BASED ON
SFC REPORTS AND LATEST GUIDANCE. LOOKS LIKE ARND 4 INCHES ACROSS
THE NW MTNS...TO LESS THAN AN INCH FROM HARRISBURG SOUTHWARD. HAVE
INCLUDED LIGHT ICE TOTALS OF A TENTH OF AN INCH OR LESS ACROSS
SOUTHERN PA.
THE COLD FRONT SHOULD BE SWINGING THROUGH THE ALLEGHENY MTNS ARND
03Z AND THE EASTERN ZONES SHORTLY AFTER 06Z. BEHIND THE FRONT...ONLY
SCT LAKE EFFECT SNOW SHOWERS SHOULD REMAIN EARLY FRIDAY MORNING
OVR THE ALLEGHENY MTNS.
LOW TEMPS TONIGHT WILL RANGE FROM THE MID TO UPPER TEENS ACROSS
THE WRN MTNS...TO THE MID AND UPPER 20S ACROSS THE SUSQ VALLEY. IF
THE FRONT IS FASTER THAN EXPECTED...THESE COULD BE A TAD TOO HIGH.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
FRIDAY WILL BE A BLUSTERY AND COLD DAY AS ARCTIC AIR PAYS A
RETURN VISIT. LINGERING SNOW SHOWERS WILL FAVOR THE USUAL WESTERN
AND NORTHERN HIGHER TERRAIN WITH CENTRAL AND EASTERN AREAS
PROBABLY SEEING LITTLE MORE THAN SOME STRAY FLURRIES.
TEMPS WILL LIKELY PEAK EARLY AND EITHER STAY STEADY OR FALL
THROUGHOUT THE DAY. WIND CHILLS WILL RANGE FROM 5 TO 15 BELOW ZERO
OVER WESTERN HIGHER ELEVATIONS BY LATE IN THE DAY AS WINDS BECOME
GUSTY BEHIND THE DEPARTING FRONT.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
TOOK OUT MENTION OF SNOW FRIDAY NIGHT...FLOW TOO NORTHERLY.
WIND CHILL ADVISORIES WILL LIKELY BE NEEDED ACROSS NORTH
CENTRAL PA FRIDAY NIGHT INTO SATURDAY MORNING UNTIL AROUND
14Z. STILL MAINLY 3RD PERIOD...WILL HOLD OFF AN ADVISORY
FOR NOW.
SATURDAY LOOKS SUNNY BUT ON THE COLD SIDE.
SOME CHC OF SOME LIGHT SNOW SATURDAY NIGHT AND EARLY SUNDAY
ACROSS THE FAR NORTH...WITH COLD FRONT DROPPING SE. HAVE
LOW CHC IN EARLY SUNDAY ACROSS THE FAR WEST.
MODELS STILL SHOW POTENTIAL FOR A LOW MOVING JUST SOUTH
OF PA LATER SUNDAY INTO EARLY MONDAY. THUS LEFT SNOW IN
THE FCST. DID SOME MAKE A FEW ADJUSTMENTS. MAIN THING WAS
TO CUT BACK POPS ACROSS THE NW EARLY MONDAY. NOT SEEING
A LOT OF POTENTIAL FOR LAKE EFFECT LATE MONDAY...FLOW TOO
NORTHERLY. THUS MADE A FEW ADJUSTMENTS MONDAY NIGHT.
ANOTHER SHOT OF COLD AIR IN FOR MONDAY NIGHT INTO TUE...AS
HIGH PRESSURE BUILDS IN FROM THE PLAINS.
MODELS HINT AT ANOTHER LOW TRACKING NEAR THE AREA ON WED.
HAVE LOW END POPS FOR SNOW. MORE COLD AIR BEHIND THAT SYSTEM.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
VFR CONDITIONS WILL RAPIDLY DETERIORATE AS SNOW OVERSPREADS THE
REGION FROM WEST TO EAST.
SNOW WILL BEGIN SHORTLY IN BRADFORD. EXPECT IFR CONDITIONS TO
DEVELOP RAPIDLY WITH THE SNOW...SPREADING EAST 18-00Z. SOUTHERN
TIER TERMINALS FROM JST-AOO EAST INTO THE LOWER SUSQ VALLEY COULD
SEE A PERIOD OF LIGHT FREEZING RAIN OR SLEET AS THE PRECIPITATION
DEVELOPS.
REDUCED CONDITIONS SHOULD IMPROVE OVERNIGHT WITH THE PASSAGE OF
THE COLD FRONT...AROUND 03Z FRIDAY OVER THE WEST. MORE LIKE
06-09Z OVER THE SERN AREAS. THE CONDITIONS AT BFD AND JST WILL
LIKELY REMAIN MVFR/IFR WITH SNOW SHOWERS INTO FRIDAY.
OUTLOOK...
SAT...VFR.
SUN...LOWER CONDITIONS POSSIBLE OVER SOUTHERN AREAS ASSOCIATED
WITH A STORM MOVING THROUGH THE CAROLINAS.
MON...REDUCED CONDS EARLY IN SNOW SHOWERS. IMPROVING FROM WEST TO
EAST AFTERNOON ONWARD.
TUE...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST FRIDAY FOR PAZ004>006-
010-011-017-024-033.
WINTER WEATHER ADVISORY UNTIL 1 AM EST FRIDAY FOR PAZ025>028-
034>036-056-057-059-063>066.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...FITZGERALD/LA CORTE
SHORT TERM...LA CORTE
LONG TERM...MARTIN
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
126 PM EST THU JAN 29 2015
.SYNOPSIS...
AN ALBERTA CLIPPER/ARCTIC COLD FRONT WILL CROSS THE AREA TONIGHT.
HIGH PRESSURE WILL RETURN FOR LATE FRIDAY INTO SATURDAY. A NEW
STORM IS EXPECTED TO PASS WELL SOUTH OF THE AREA LATER SUNDAY
INTO MONDAY...FOLLOWED BY ANOTHER SURGE OF COLD AIR FOR EARLY
NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
HAVE DECIDED TO COVER THE THREAT FOR ICY CONDITIONS INTO THE
EVENING HOURS WITH A WEATHER ADVISORY OVER MY SOUTHERN TIER.
OVERALL REASONING HAS NOT CHANGED WITH JUST ENOUGH WARM AIR ALOFT
EXPECTED TO CAUSE A PERIOD OF NUISANCE-TYPE ICING.
THE MAIN AREA OF PRECIP IS ON TRACK AND SHOWN BY THE HRRR TO BE
ENTERING MY WESTERN ZONES BY 18-19Z. STILL SOME CONCERN FOR A
BRIEF PERIOD OF LIGHT FREEZING RAIN OR SLEET SO WE PUT AN
ADVISORY OVER THE SOUTHERN COUNTIES TO COVER THE POTENTIAL FOR
SOME LIGHT ICING. GUIDANCE IS CONSISTENT IN SHOWING WARM AIR
SURGING IN ALOFT TODAY...THEN BEING PINCHED OFF QUICKLY AS PRECIP
DEVELOPS AND THE COLUMN EVAPORATIVELY COOLS. HOWEVER...THE
RAP/HRRR HOURLY DATA SHOW THE WARM AIR ACTUALLY PUSHING BACK NORTH
BETWEEN 21-00Z OVER THE SWRN ZONES...COMPLICATING THE PRECIP TYPE
SCENARIO FROM THE LAURELS EASTWARD ALONG THE MARYLAND BORDER
COUNTIES.
A STRONG SHOT OF WAA ALOFT AND MODERATELY STG UPPER LEVEL
DIVERGENCE ASSOCIATED WITH THE RIGHT ENTRANCE REGION OF AN UPPER
LVL JET MAX ACROSS SRN ONTARIO WILL LEAD TO PERIODS OF SNOW
THIS AFTERNOON INTO TONIGHT. ALREADY 4-STAR SNOW AT MEADVILLE
WITH MODERATE SNOW OVER NERN OHIO UP INTO ERIE.
SNOWFALL TOTALS IN OUR GRIDDED FORECASTS LOOK REASONABLE AND WE
HAVE INCLUDED LIGHT ICE TOTALS OF A TENTH OF AN INCH OR LESS.
THE COLD FRONT WILL BE ENTERING WESTERN PA JUST AFTER DARK...AND
SHOULD BE SWINGING THROUGH MY EASTERN ZONES BETWEEN MIDNIGHT AND
6 AM. SNOW WILL TAPER TO SNOW SHOWERS AND FLURRIES BY LATE
TONIGHT...MAINLY IN THE ISOLATED FORM ACROSS THE CENTRAL AND
SOUTHERN VALLEYS.
LOW TEMPS TONIGHT WILL RANGE FROM THE MID TO UPPER TEENS ACROSS
THE WRN MTNS...TO THE MID AND UPPER 20S ACROSS THE SUSQ VALLEY. IF
THE FRONT IS FASTER THAN EXPECTED...THESE COULD BE A TAD TOO HIGH.
&&
.SHORT TERM /FRIDAY/...
FRIDAY WILL BE A BLUSTERY AND COLD DAY AS ARCTIC AIR PAYS A
RETURN VISIT. LINGERING SNOW SHOWERS WILL FAVOR THE USUAL WESTERN
AND NORTHERN HIGHER TERRAIN WITH CENTRAL AND EASTERN AREAS
PROBABLY SEEING LITTLE MORE THAN SOME STRAY FLURRIES.
TEMPS WILL LIKELY PEAK EARLY AND EITHER STAY STEADY OR FALL
THROUGHOUT THE DAY. WIND CHILLS WILL RANGE FROM 5 TO 15 BELOW ZERO
OVER WESTERN HIGHER ELEVATIONS BY LATE IN THE DAY AS WINDS BECOME
GUSTY BEHIND THE DEPARTING FRONT.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
PERIODS OF GENERALLY LIGHTER SNOW WILL LINGER INTO EARLY
FRIDAY...AS THE MAIN COLD FRONT DROPS SE.
A TIGHT LLVL PRESSURE GRADIENT IN THE WAKE OF THE COLD FRONT WILL
BRING GUSTY NORTHWEST WINDS AND SLOWLY FALLING TEMPS ACROSS THE
REGION DURING THE DAYLIGHT HOURS FRIDAY. WIND GUSTS WILL BE IN
THE MID TO UPPER 20 KT RANGE FOR MOST AREAS CREATING A WIND CHILL
IN THE SINGLE DIGITS TO LOW TEENS IN THE SUSQ VALLEY....AND 5
BELOW TO 15 BELOW ACROSS THE NRN AND WRN MTNS.
FRIDAY NIGHT WILL BE BITTERLY COLD...AS SKIES CLEAR AND WINDS DIE
DOWN. LOW TEMPS WILL VARY FROM THE SINGLE DIGITS BELOW ZERO ACROSS
THE NORTH...TO SINGLE DIGITS ABOVE ZERO IN THE SOUTH.
A BRIGHT DAY ON SAT...BUT NOT REAL WARM.
STILL HAVE CHC POPS ON SUNDAY. A LOT OF SPREAD IN THE MODEL OUTPUT
THE LAST FEW DAYS. 12Z MODELS BACKING OFF SOME NOW. PATTERN
SUPPORTS LOW PRESSURE SYSTEMS THAT ARE FAST MOVING AND WEAK. WOULD
STILL EXPECT SOME LIGHT SNOW INTO MONDAY MORNING.
A COLD NIGHT MONDAY NIGHT...AS THE NEXT HIGH BUILDS INTO
THE AREA.
SOME HINTS AT ANOTHER FAST MOVING LOW FOR MID WEEK...FOR NOW
WENT WITH CHC POPS.
MINOR CHANGES TO THE PACKAGE MADE.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
VFR CONDITIONS WILL RAPIDLY DETERIORATE AS SNOW OVERSPREADS THE
REGION FROM WEST TO EAST.
SNOW WILL BEGIN SHORTLY IN BRADFORD. EXPECT IFR CONDITIONS TO
DEVELOP RAPIDLY WITH THE SNOW...SPREADING EAST 18-00Z. SOUTHERN
TIER TERMINALS FROM JST-AOO EAST INTO THE LOWER SUSQ VALLEY COULD
SEE A PERIOD OF LIGHT FREEZING RAIN OR SLEET AS THE PRECIPITATION
DEVELOPS.
REDUCED CONDITIONS SHOULD IMPROVE OVERNIGHT WITH THE PASSAGE OF
THE COLD FRONT...AROUND 03Z FRIDAY OVER THE WEST. MORE LIKE
06-09Z OVER THE SERN AREAS. THE CONDITIONS AT BFD AND JST WILL
LIKELY REMAIN MVFR/IFR WITH SNOW SHOWERS INTO FRIDAY.
OUTLOOK...
SAT...VFR.
SUN...LOWER CONDITIONS POSSIBLE OVER SOUTHERN AREAS ASSOCIATED
WITH A STORM MOVING THROUGH THE CAROLINAS.
MON...REDUCED CONDS EARLY IN SNOW SHOWERS. IMPROVING FROM WEST TO
EAST AFTERNOON ONWARD.
TUE...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST FRIDAY FOR PAZ004>006-
010-011-017-024-033.
WINTER WEATHER ADVISORY UNTIL 1 AM EST FRIDAY FOR PAZ025>028-
034>036-056-057-059-063>066.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LAMBERT/MARTIN
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1141 AM EST THU JAN 29 2015
.SYNOPSIS...
AN ALBERTA CLIPPER WILL CROSS THE AREA THIS AFTERNOON AND
TONIGHT. HIGH PRESSURE WILL RETURN FOR LATE FRIDAY INTO SATURDAY.
A NEW STORM MAY BRING A ROUND OF WINTRY WEATHER FOR LATER SUNDAY
INTO MONDAY...BEFORE ANOTHER SURGE OF COLD AIR WORKS INTO THE AREA
EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLOUDS CONTINUE TO THICKEN OVER THE REGION AS OF LATE
MORNING...WITH THE FIRST PRECIPITATION REACHING THE GROUND OVER
FAR WESTERN PA IN THE FORM OF SOME SLEET OR FREEZING RAIN.
THE MAIN AREA OF PRECIP IS SHOWN BY THE HRRR TO BE ENTERING MY
WESTERN ZONES BY 18Z/1PM. STILL SOME CONCERN FOR A BRIEF PERIOD OF
LIGHT FREEZING RAIN OR SLEET AT THE ONSET...EVEN OUTSIDE THE
CURRENT ADVISORY AREAS. SNOWFALL TOTALS IN OUR GRIDDED FORECASTS
LOOK REASONABLE AND WE ARE NOT EXPECTING MORE THAN A TRACE OF
ICE...BUT IF IT SHOULD COINCIDE WITH THE EVENING COMMUTE UNTREATED
ROADS COULD POSE TRAVEL PROBLEMS. AT THIS STAGE WE PLAN TO HANDLE
THIS EXPECTED BRIEF PERIOD OF ICE WITH SPECIAL WEATHER
STATEMENTS AND NOWCASTS...AND WILL MONITOR FOR THE POSSIBLE NEED
FOR A HEADLINE PRODUCT.
A STRONG SHOT OF WAA ALOFT AND MODERATELY STG UPPER LEVEL
DIVERGENCE ASSOCIATED WITH THE RIGHT ENTRANCE REGION OF AN UPPER
LVL JET MAX ACROSS SRN ONTARIO WILL LEAD TO PERIODS OF LIGHT TO
BRIEFLY MDT SNOW FOCUSED ACROSS THE NW HALF OF THE STATE THIS
AFTERNOON INTO TONIGHT.
GUIDANCE IS CONSISTENT IN SHOWING WARM AIR SURGING IN ALOFT
TODAY...THEN BEING PINCHED OFF QUICKLY AS PRECIP DEVELOPS AND THE
COLUMN EVAPORATIVELY COOLS. HOWEVER...THE RAP/HRRR HOURLY DATA
SHOW THE WARM AIR ACTUALLY PUSHING BACK NORTH BETWEEN 21-00Z OVER
THE SWRN ZONES...WHICH IF IT COINCIDES WITH ONGOING PRECIP WILL
COMPLICATE THE PRECIP TYPE SCENARIO OVER THE LAURELS AND SOME
MARYLAND BORDER COUNTIES. THE POTENTIAL FOR THE WINTRY MIX IS THE
LOW PROBABILITY OUTCOME AT THIS POINT.
REST FROM EARLIER...
MODEL CONSENSUS REMAINS UNCHANGED TO A LARGE
DEGREE WITH RESPECT TO THE QPF FROM THE CLIPPER SYSTEM MOVING BY
JUST TO OUR NORTH ACROSS LAKES ERIE AND ONTARIO LATE TODAY AND
TONIGHT. A GENERAL 2-4 INCH SNOWFALL IS LIKELY OVER THE
ALLEGHENIES OF WRN PENN WHERE A WINTER WEATHER ADVISORY IS IN
EFFECT FROM LATE THIS MORNING THROUGH 12Z FRIDAY. THE CENTRAL
RIDGE AND VALLEY OF THE STATE WILL 1-2 INCHES BY MIDNIGHT
TONIGHT...WHILE COUNTIES THROUGHOUT THE LOWER SUSQ VALLEY RECEIVE
GENERALLY LESS THAN 0NE INCH. A BIT OF SLEET AND EVEN PATCHY ICE
FROM LIGHT FREEZING RAIN IS POSSIBLE ACROSS SOUTHERN PENN LATE
TODAY AND THIS EVENING AS THE RATHER SHALLOW WEDGE OF WARMER AIR
ALOFT DRIFTS EAST.
HIGHS THIS AFTERNOON WILL REACH THE UPPER 20S TO AROUND FREEZING
IN THE INCREASING/BRISK SW FLOW AHEAD OF THE CLIPPER/ARCTIC FRONT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
THE BRUNT OF THE CURRENT STORM SYSTEM WILL OCCUR LATE THIS
AFTERNOON AND EARLY TONIGHT...WITH SOME BRIEF PERIODS OF MDT SNOW
LIKELY AS ONE OR MORE N/S BANDS OF ENHANCED 850-700 MB UVVEL
CROSSES THE REGION. 03Z SREF INDICATES THAT AN AXIS OF ANOMALOUS
/2-3 SIGMA/ 850MB MOISTURE FLUX AND SIMILARLY ANOMALOUS /50 KT/
SWRLY LLJ WILL BE GRADUALLY WEAKENING AS IT CROSSES PENN BETWEEN
21Z AND 06Z FRI.
SFC COLD FRONT EXTENDING SOUTH FROM THE LOW...PUSHES ACROSS OUR
WESTERN ZONES LATE THIS EVENING...THEN CLEARS THE SUSQ VALLEY
BETWEEN 07-09Z FRIDAY. SNOW WILL TAPER TO SNOW SHOWERS BY LATE
TONIGHT...MAINLY IN THE ISOLATED FORM ACROSS THE CENTRAL AND
SOUTHERN VALLEYS.
LOW TEMPS TONIGHT WILL RANGE FROM THE MID TO UPPER TEENS ACRS THE
WRN MTNS...TO THE MID AND UPPER 20S ACROSS THE SUSQ VALLEY. A
SLIGHTLY EARLIER TIMING OF THE CFROPA WILL KNOCK THESE VALUES DOWN
BY A FEW DEG F.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
PERIODS OF GENERALLY LIGHTER SNOW WILL LINGER INTO EARLY
FRIDAY...AS THE MAIN COLD FRONT DROPS SE.
A TIGHT LLVL PRESSURE GRADIENT IN THE WAKE OF THE COLD FRONT WILL
BRING GUSTY NORTHWEST WINDS AND SLOWLY FALLING TEMPS ACROSS THE
REGION DURING THE DAYLIGHT HOURS FRIDAY. WIND GUSTS WILL BE IN
THE MID TO UPPER 20 KT RANGE FOR MOST AREAS CREATING A WIND CHILL
IN THE SINGLE DIGITS TO LOW TEENS IN THE SUSQ VALLEY....AND 5
BELOW TO 15 BELOW ACROSS THE NRN AND WRN MTNS.
FRIDAY NIGHT WILL BE BITTERLY COLD...AS SKIES CLEAR AND WINDS DIE
DOWN. LOW TEMPS WILL VARY FROM THE SINGLE DIGITS BELOW ZERO ACROSS
THE NORTH...TO SINGLE DIGITS ABOVE ZERO IN THE SOUTH.
A BRIGHT DAY ON SAT...BUT NOT REAL WARM.
STILL HAVE CHC POPS ON SUNDAY. A LOT OF SPREAD IN THE MODEL OUTPUT
THE LAST FEW DAYS. 12Z MODELS BACKING OFF SOME NOW. PATTERN
SUPPORTS LOW PRESSURE SYSTEMS THAT ARE FAST MOVING AND WEAK. WOULD
STILL EXPECT SOME LIGHT SNOW INTO MONDAY MORNING.
A COLD NIGHT MONDAY NIGHT...AS THE NEXT HIGH BUILDS INTO
THE AREA.
SOME HINTS AT ANOTHER FAST MOVING LOW FOR MID WEEK...FOR NOW
WENT WITH CHC POPS.
MINOR CHANGES TO THE PACKAGE MADE.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
VFR WILL CONTINUE INTO EARLY AFTERNOON BEFORE RAPIDLY
DETERIORATING TO MVFR/IFR AS SNOW OVERSPREADS THE FLYING AREA
FROM WEST TO EAST.
SNOW WILL BEGIN AROUND OR SHORTLY AFTER NOON IN BRADFORD. EXPECT
IFR CONDITIONS TO DEVELOP RAPIDLY WITH THE SNOW...SPREADING EAST
18-00Z.
REDUCED CONDITIONS SHOULD IMPROVE OVERNIGHT WITH THE PASSAGE OF
THE COLD FRONT...AROUND 06Z FRIDAY OVER THE WEST. MORE LIKE 09-12Z
OVER THE SERN AREAS. THE CONDITIONS AT BFD AND JST WILL LIKELY
REMAIN MVFR/IFR INTO FRIDAY.
OUTLOOK...
SAT...VFR.
SUN...RESTRICTIONS DEVELOPING WITH SNOW OVERSPREADING FROM THE
WEST.
MON...REDUCED CONDS EARLY IN SNOW. IMPROVING FROM WEST TO EAST
AFTERNOON ONWARD.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST FRIDAY FOR PAZ004>006-
010-011-017-024-033.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...LAMBERT
LONG TERM...LAMBERT/MARTIN
AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1258 PM EST THU JAN 29 2015
.SYNOPSIS...
IN THE WAKE OF A COLD FRONTAL PASSAGE...HIGH PRESSURE WILL BUILD
INTO THE REGION LATER ON FRIDAY. THE HIGH WILL LINGER OVER THE AREA
INTO SUNDAY BEFORE MOISTURE RETURNS OUT AHEAD OF A DEVELOPING
LOW PRESSURE SYSTEM. DRY CANADIAN HIGH MOVES BACK INTO THE AREA BY
TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1240 PM EST UPDATE...LATEST MESO-SCALE MODELS WERE HANDLING WELL
WITH THE BAND OF PRECIP CROSSING THE NC MTNS ZONES AS OF EARLY THIS
AFTERNOON. HENCE...HAVE BLENDED WITH THE CAMPOP FEATURING LIKELY
POPS OVER THE RIDGE TOPS OF THE BLUE RIDGE. ALSO...HAVE CARRIED A
MIX OF RAIN AND SNOW OVER PORTIONS OF THE NORTHERN NC MTNS/VALLEYS
AS TEMPS STRUGGLE TO WARM UP ABOVE 40S.
1000 EST THURSDAY UPDATE...LATEST SURROUNDING REGIONAL RADARS SHOW A
BAND OF LIGHT RETURNS WAS APPROACHING THE SOUTHERN APPALACHIANS FROM
THE TN VALLEY AS OF THIS MORNING. LATEST HRRR AND OTHER MESOSCALE
MODELS INDICATE THAT THIS BAND OF LIGHT PRECIP ASSOCIATED WITH AN
UPPER WAVE WILL MOVE EAST ACROSS THE NC MTN ZONES BETWEEN 16-18Z AND
ACROSS THE NC FOOTHILLS AND PORTIONS OF THE NORTHERN NC PIEDMONT
18-20Z. THEREFORE...POPS WERE UPDATED TO ACCOUNT FOR THIS THRU THIS
AFTERNOON. HOWEVER...PRECIP AMOUNTS APPEAR TO BE VERY LIGHT GIVEN
RELATIVELY DRY AIRMASS AND SHALLOW MOIST LAYER. NO WINTRY P-TYPE IS
EXPECTED THRU THIS AFTERNOON GIVEN GOOD WARMING TREND.
1115 UTC UPDATE...WINDS WERE UPDATED WITH A TWO TO ONE BLEND OF THE
NAM AND ADJMAV...FAVORING THE FORMER FOR STRINGER WINDS AND GUSTS IN
THE MOUNTAINS...BOTH AHEAD OF AND BEHIND THE APPROACHING COLD FRONT.
GUSTS STILL APPEAR TO REACH ADVISORY CRITERIA ONLY AT THE VERY
HIGHEST MOUNTAIN PEAKS LATE TONIGHT...SO NO ADVISORY IS PLANED AT
THIS TIME. SKY COVER WAS UPDATED FROM INFRARED SATELLITE IMAGERY.
AT 230 AM EST THURSDAY...AN UPPER RIDGE OF MODEST AMPLITUDE WILL
CROSS THE EASTERN SEABOARD THIS MORNING...WHILE AND UPPER TROUGH
MOVES FROM THE MS RIVER VALLEY TO THE OH AND TN RIVER VALLEYS. A
SHORTWAVE MOVING THROUGH THIS TROUGH WILL REACH THE CENTRAL
APPALACHIANS BY MIDDAY. THE RIDGE MOVES TO THE GULF STREAM THIS
AFTERNOON...WHILE THE SHORTWAVE MOVES OFF THE MID ATLANTIC COAST.
ANOTHER AND MORE ROBUST SHORTWAVE MOVING THROUGH THE TROUGH REACHES
THE CENTRAL AND SOUTHERN APPALACHIANS IN THE MIDDLE OF THURSDAY
NIGHT...MOVING EAST OF OUR AREA BY MORNING....WHILE THE TROUGH AXIS
REACHES THE EAST COAST.
A SURFACE RIDGE ALONG THE EAST COAST WILL MOVE OFFSHORE TODAY...
WHILE A COLD FRONT MOVES FROM THE MS RIVER VALLEY TO THE
APPALACHIANS. PRECIPITATION AHEAD OF THE FRONT WILL REACH THE
MOUNTAINS SOMETIME THIS MORNING...PERHAPS EARLY ENOUGH TO START AS
LIGHT SNOW. WITH WARMING...SNOW LEVELS RISE ABOVE THE MOUNTAIN TOPS
TODAY. NO APPRECIABLE SNOW ACCUMULATIONS ARE EXPECTED THIS MORNING.
THE MODELS DO NOT SHOW MUCH DEPTH TO THE MOIST LAYER EAST OF THE
BLUE RIDGE...AND PRECIPITATION CHANCES ARE QUITE LIMITED THERE.
FRONTAL PASSAGE TAKES PLACE OVERNIGHT...WITH DOWNSLOPE DRYING IN THE
LEE OF THE MOUNTAINS...AND MOIST NW FLOW INTO THE NC MOUNTAINS
BORDERING TN. SNOW LEVEL ARE EXPECTED TO FALL TO THE VALLEY FLOORS
THIS EVENING...WHILE COVERAGE RETREATS CLOSER TO THE TN BORDER.
RIGHT NOW IT APPEARS THAT SNOWFALL ACCUMULATIONS WILL RUN JUST UNDER
TWO INCHES OVERNIGHT...BUT ADVISORY CRITERIA WILL ONLY BE APPROACHED
ON THE VERY HIGHEST PEAKS...SO NO SNOW ADVISORY IS PLANNED. WINDS
WILL INCREASE IN THE TIGHT PRESSURE GRADIENT BEHIND THE FRONT...BUT
WIND ADVISORY CRITERIA WILL ONLY BE REACHED LATE TONIGHT ON PEAKS
OVER 5000 FT...SO NO WIND ADVISORY IS PLANNED AT THIS TIME.
HIGH TEMPERATURES WILL RUN NEAR NORMAL TODAY AS WARM ADVECTION UNDER
THE UPPER RIDGE IS OFFSET BY INCREASING CLOUD COVER...AND LOW
TEMPERATURES TONIGHT WILL RUN SLIGHTLY ABOVE NORMAL AS WINDS KEEP
THE ATMOSPHERE MIXED.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 115 AM THURSDAY...THE SHORT TERM BEGINS WITH AN INCREASING
SUBSIDENCE ZONE AND A WANING NWFS EVENT. DRY CP AIR WILL BEGIN
FILTERING INTO THE MTNS AND LIMIT THE ADDITIONAL SNOWFALL POTENTIAL.
LIKELY AROUND ANOTHER HALF TO ONE INCH THROUGH 21Z ACROSS WRN MTN
SPINE. GOOD H85 CAA ALONG WITH DEEP SUBSIDENCE WILL CONTINUE THE
STRONG WINDS/GUSTS ACROSS THE NC MTNS...WITH ADVISORY OR EVEN
WARNING CRITERIA BEING MET ABOVE 4000 FEET AS MODEL SOUNDINGS
INDICATE AN UPWARD TREND IN VELOCITIES ATOP THE MIXED LAYER THROUGH
MID AFTERNOON. WILL KEEP THE HWO MENTION FOR NOW AND THE DAY SHIFT
WILL LIKELY ISSUE THE NPW AS THE EVENT MOVES INTO THE 2ND PERIOD.
WINDS WILL RELAX SLOWLY THROUGH THE EVENING WITH A GOOD H85 TGRAD
EVENTUALLY LOOSENING AFT 00Z. MAX TEMPS WILL ABOUT 15 DEGREES BELOW
NORMAL MTN VALLEYS AND 3-5 DEGREES BELOW NORMAL NON/MTNS. HEIGHTS
BEGIN TO RISE FRI NIGHT AND FLAT RIDGING WILL BE IN PLACE BY SAT
AFTERNOON. THIS WILL ENABLE THE CP SFC HIGH TO CROSS THE FA
THROUGH THE PERIOD BECOMING SITUATED OFF THE CAROLINA COAST BY 12Z
SUN. THUS...SKIES WILL CLEAR AND TEMPS WILL REMAIN A FEW DEGREES
BELOW NORMAL AS A LLVL THETA/E TROF MIXES IN.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 255 AM THURSDAY MORNING...THE MEDIUM RANGE FCST PICKS UP AT
12Z ON SUNDAY WITH RELATIVELY ZONAL UPPER FLOW OVER THE CAROLINAS
AND A DEEPENING UPPER TROF TO OUR WEST. OVER THE NEXT 24 TO 36
HRS...THE TROF AXIS IS EXPECTED TO PASS OVERHEAD WITH MORE ZONAL
FLOW IN ITS WAKE. DURING THIS PERIOD...A SOUTHERN STREAM H5 LOW
SPINS UP OVER THE BAJA PENINSULA AND GRADUALLY DRIFTS NE TOWARDS OUR
AREA. BY THE END OF THE MEDIUM RANGE...THIS LOW WILL LIKELY GET
ABSORBED BY ANOTHER DEEPENING UPPER TROF.
AT THE SFC...HIGH PRESSURE WILL BE MOVING OFF THE SE COAST EARLY
SUNDAY AS ANOTHER LOW SPINS UP TO OUR WSW OVER THE LOWER MISS RIVER
VALLEY. THE ASSOCIATED BROAD AREA OF DEEP LYR MOISTURE WILL SPREAD
OVER THE REGION THRU THE DAY WITH OVERCAST CONDITIONS AND LIKELY
POPS BY LATE SUN/EARLY MON FOR PRETTY MUCH ALL ZONES. THE GFS
REMAINS ABOUT 12 HRS FASTER WITH THE DEVELOPMENT OF THIS SYSTEM
COMPARED TO THE ECMWF AND CMC. IN THE LOWS WAKE...ANOTHER CANADIAN
HIGH PUSHES BACK INTO THE REGION FROM THE NW ON MON AND DRIES THINGS
OUT. THE CENTER OF THE HIGH WILL PASS OVER THE AREA ON TUES AND MOVE
OFFSHORE BY EARLY WED. BEYOND THIS POINT THE MODEL GUIDANCE REMAINS
FAIRLY AMBIGUOUS WITH THE SYNOPTIC PATTERN. THE GFS BRINGS ANOTHER
REINFORCING CANADIAN HIGH DOWN OVER THE REGION ON THURS AND KEEPS
THINGS DRY. THE ECMWF TRIES TO SPIN UP ANOTHER MILLER A TYPE LOW
OVER THE NORTHERN GULF OF MEX ON WED AND MOVE THE SYSTEM ACROSS THE
CAROLINA COAST LATE WED/EARLY THURS AND AFTER THAT...IT DRIES THINGS
OUT LIKE THE GFS. THE PREVIOUS RUNS OF THE GFS HINTED MORE TOWARDS
THE MILLER A TYPE LOW DEVELOPING...SO THE CURRENT DRY SCENARIO LOOKS
QUESTIONABLE. AS FOR THE SENSIBLE FCST...I TRENDED A BIT COOLER FOR
THE MON/TUES PERIOD WITH LOWS EARLY TUES IN THE LOW TO MID 20S
ACROSS THE THE LOWER ELEVATIONS AND TEENS ACROSS THE HIGHER TERRAIN.
POP TRENDS WERE NOT CHANGED MUCH FOR THE FIRST HALF OF THE PERIOD
WITH BEST CHANCES LATE SUN THRU EARLY MON. FOR TUES/WED...I KEPT
POPS AT SLIGHT TO SOLID CHANCE DUE TO THE CONTINUING UNCERTAINTY
WITH THE GULF LOW.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AT KCLT...EXPECT VFR CONDITIONS TO PERSIST THROUGH 18Z FRIDAY. A
LIGHT BAND OF PRECIP ASSOCIATED WITH A WEAK UPPER WAVE WILL CROSS
THE NC MTNS THROUGH THIS AFTERNOON. HOWEVER...LATEST MESO-MODELS
INDICATE THAT THIS FEATURE WILL WEAKEN CONSIDERABLY AS IT ENTERS THE
NC FOOTHILLS/PIEDMONT BY EARLY THIS AFTERNOON. SO NO PRECIP WAS
MENTIONED IN THE TAF. SW WINDS SHOULD PERSIST WITH OCCASIONAL GUSTS
TO AROUND 15-20KTS POSSIBLE THRU THIS AFTERNOON. TONIGHT...SW WINDS
SHOULD TO VEER TO THE NW AS A SURFACE COLD FRONT PUSHES THROUGH THE
REGION. AS SURFACE PRESSURE TIGHTENS UP BEHIND THE FRONT...GUSTY NW
WINDS OF 15-20KTS WILL DEVELOP BY AROUND 15Z. CLOUD CIGS WILL BOTTOM
OUT AROUND 8K FT DURING THE FROPA TONIGHT.
ELSEWHERE...VFR THROUGH THE PERIOD EXCEPT KAVL WHERE MVFR CLOUDS
WILL SPREAD IN FROM THE NORTH TONIGHT DUE TO THE FROPA. A LIGHT BAND
OF PRECIP WILL MOVE ACROSS THE NC MTN ZONES THROUGH THIS AFTERNOON.
HOWEVER...THE PRECIP APPEARS TO BE VERY LIGHT AND IT WILL BE MAINLY
CONFINED TO THE RIDGE TOPS OF THE MTNS. HENCE...NO PRECIP WAS
MENTIONED IN KAVL. OTHERWISE...EXPECT MOSTLY CLOUDY SKIES WITH SW
WINDS PERSISTING THROUGH LATE THIS EVENING ACROSS MUCH OF THE
REGION. WINDS WILL VEER THE NW TONIGHT AS A SURFACE COLD FRONT
PUSHES THROUGH THE AREA. AGAIN...PRECIP CHANCES ARE TOO LOW TO
MENTION IN THE TAF. TIGHT PRESSURE GRADIENT BEHIND THE FRONT WILL
RESULT IN GUSTY NW WINDS ACROSS MUCH OF THE REGION BY FRI MORNING.
OUTLOOK...A PAIR OF CLIPPER SYSTEMS WILL BRING CHANCES FOR RAIN OR
SNOW SHOWERS TO THE NC MTNS FRI. MOST OF THESE SHOWERS WILL REMAIN
WEST AND NORTH OF KAVL...BUT BRIEF PERIODS OF RESTRICTIONS CANNOT BE
RULED OUT. OTHERWISE...MAINLY VFR CONDITIONS ARE EXPECTED ACROSS THE
AREA UNTIL MOISTURE BEGINS TO RETURN SUNDAY. DRYING IS EXPECTED ON
MONDAY.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 96% HIGH 81% MED 60%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...JAT/JOH
SHORT TERM...SBK
LONG TERM...JPT
AVIATION...JOH