Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/28/15
AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
755 PM PST TUE JAN 27 2015
.UPDATE...
LATEST SATELLITE IMAGERY SHOWED UPPER LEVEL WAVE LIFTING OUT OF
WESTERN NV AND THE EASTERN SIERRA THIS EVENING WITH BROAD BAND OF
RADAR ECHOES SHOWING AN OVERALL DECREASE IN COVERAGE THE PAST
HOUR. SURFACE OBSERVATIONS ARE CONFIRMING THIS TREND SHOWING AN
END TO LIGHT PRECIPITATION. BOTH THE 00Z GFS/NAM ALONG WITH THE
LATEST HRRR INDICATE THAT ALL PRECIPITATION WILL END BY MIDNIGHT.
SO WE HAVE UPDATED TO DECREASE POPS TO SLIGHT CHANCE THIS EVENING
AND REMOVE THEM IN ALL AREAS BUT EASTERN PORTIONS OF THE BASIN AND
RANGE OVERNIGHT. OTHERWISE, ABUNDANT MOISTURE WILL BE LEFT BEHIND
AND KEEP SKIES MOSTLY CLOUDY. IF THERE ARE ANY BREAKS IN THE
CLOUDS LATE TONIGHT, PATCHY FOG/FREEZING FOG IS POSSIBLE. HOHMANN
&&
.SYNOPSIS...
THE LOW PRESSURE SYSTEM THAT BROUGHT RAIN AND MOUNTAIN SNOW WILL
CONTINUE TO EXIT WITH ABUNDANT MOISTURE AND CLOUD COVER LINGERING
THROUGH THURSDAY. A FEW SHOWERS ARE POSSIBLE SOUTH OF HIGHWAY 50
THURSDAY BEFORE DRIER CONDITIONS RETURN FOR THE WEEKEND.
&&
.PREVIOUS DISCUSSION... /ISSUED 241 PM PST TUE JAN 27 2015/
SYNOPSIS...
LOW PRESSURE WILL EXIT OUT OF THE REGION TONIGHT AS LIGHT VALLEY
RAIN AND MOUNTAIN SNOW TAPERS OFF THIS EVENING. TEMPERATURES WILL
COOL OFF THROUGH THE END OF THE WEEK WITH A FEW SHOWERS POSSIBLE
SOUTH OF HIGHWAY 50 THURSDAY AND FRIDAY. DRIER CONDITIONS RETURN FOR
THE WEEKEND BEFORE MOISTURE RETURNS TO THE NORTHWEST EARLY NEXT
WEEK.
SHORT TERM...
VALLEY RAIN AND MOUNTAIN SNOW WILL TAPER OFF THIS EVENING AND
OVERNIGHT AS LOW PRESSURE MOVES EAST OF THE AREA. WE STARTED SEEING
STEADY LIGHT RAIN IN WESTERN NEVADA AS EARLY AS 4AM THIS MORNING
WHICH THEN SPREAD NORTHWEST TO THE INTERSTATE 80 CORRIDOR AND TAHOE
BASIN THROUGH THE MORNING HOURS. THE GREATEST PRECIPITATION AMOUNTS
HAVE BEEN MAINLY AROUND THE FALLON AREA AS WELL AS IN THE CARSON
RANGE WITH PRECIP TOTALS AROUND 0.25-0.30". OTHERWISE, PRECIP
AMOUNTS HAVE BEEN PRETTY MEAGER AT LESS THAN 0.10". AROUND LAKE
TAHOE AND DOWN INTO MONO COUNTY ABOVE 6500-7000 FEET, LIGHT SNOW
AMOUNTS OF UP TO 3 INCHES WERE OBSERVED WITH ICY ROAD CONDITIONS
REPORTED BETWEEN MOUNT ROSE SUMMIT AND INCLINE VILLAGE. AS THE LOW
PRESSURE PUSHES INTO EASTERN NEVADA TONIGHT, THIS WILL SHIFT THE
DEFORMATION ZONE FARTHER NORTH AND EAST AS WELL. NO FOG IS EXPECTED
FOR TONIGHT IN THE SIERRA VALLEYS, DUE TO ABUNDANT CLOUDS. ALTHOUGH,
IF WE CLEAR OUT OVERNIGHT, WE COULD SEE FOG BY EARLY TOMORROW
MORNING.
REGARDING DROUGHT IMPACTS, THIS LIGHT PRECIPITATION WILL HAVE
VIRTUALLY NO EFFECT ON THE AREA`S LONG TERM DROUGHT. PUTTING THIS IN
PERSPECTIVE, IT`S ONLY A DROP IN A BUCKET COMPARED TO THE DEFICIT WE
HAVE FOR THE SIERRA AND WESTERN NEVADA. THIS RAIN DID, HOWEVER, PUSH
JANUARY 2015 UP TO TIE FOR THE 7TH DRIEST JANUARY ON RECORD FOR THE
RENO-TAHOE AIRPORT (AS OPPOSED BEING TIED FOR THE DRIEST ON RECORD
BEFORE TODAY!). THE 0.06" OF RAIN THE AIRPORT OBSERVED TODAY IS THE
ONLY MEASURABLE PRECIP WE`VE GOTTEN THIS MONTH.
A WEAK SHORTWAVE RIDGE BUILDS OVER CA/NV ON WEDNESDAY ALTHOUGH
ABUNDANT CLOUDS AND COOLER TEMPERATURES WILL REMAIN. A BAGGY TROUGH
MOVES ONSHORE THURSDAY WITH MEAGER MOISTURE BEING PULLED UP FROM
SOUTHERN CA/NV. WE LEFT IN A SLIGHT CHANCE OF LIGHT RAIN/SNOW SOUTH
OF HIGHWAY 50 THURSDAY AND THURSDAY NIGHT AS THIS WEAK TROUGH
TRANSITIONS OVER THE FORECAST AREA. BY FRIDAY, THIS LOW WILL
STRENGTHEN AS IT MOVES INTO THE DESERT SOUTHWEST. AS IT CONSOLIDATES
AND TIGHTENS UP, THIS SHOULD TAKE CLOUDS AND PRECIP INTO SOUTHERN
NEVADA, LEAVING CLEARING SKIES AS HIGH PRESSURE BUILDS INTO NORTHERN
CA/NV. HOON
LONG TERM...SATURDAY THROUGH TUESDAY...
GREATEST CHANGE TO THE FORECAST WAS TO ACCOUNT FOR THE MOIST FLOW
MOVING INTO THE PACIFIC NORTHWEST EARLY NEXT WEEK WITH SMALL CHANCES
PRECIPITATION MAY MAKE IT AS FAR SOUTH AS INTERSTATE 80. OTHERWISE,
THE FORECAST REMAINS LARGELY UNCHANGED.
POSITIVELY TILTED UPPER LEVEL RIDGE BUILDS INTO THE NORTHWEST
SATURDAY PUSHING THE CLOSED LOW IN THE SOUTHWEST SOUTH INTO
BAJA/NORTHERN MEXICO. EASTERLY WINDS WILL DEVELOP BETWEEN THESE TWO
FEATURES WITH SIERRA RIDGE GUSTS POSSIBLY REACHING 60 TO 80 MPH
SATURDAY, WEAKENING BY SUNDAY. AS THE RIDGE STRENGTHENS INTO SUNDAY
IT WILL HELP KEEP SKIES MOSTLY CLEAR WITH HIGH TEMPERATURES
CLIMBING 10 TO 12 DEGREES ABOVE NORMAL. THIS TRANSLATES TO MID 50S
TO LOW 60S ACROSS MOST VALLEYS WITH 40S TO LOW 50S IN THE MOUNTAINS.
A STREAM OF PACIFIC MOISTURE REACHES THE NORTHWEST COAST EARLY NEXT
WEEK AND RECENT OPERATIONAL MODEL RUNS AND SEVERAL ENSEMBLES ARE
SHOWING PRECIPITATION DEVELOPING ACROSS EXTREME NORTHERN CA/NV
NORTHWARD. CONFIDENCE IN EXACTLY HOW FAR SOUTH PRECIPITATION WILL
REACH IS LOW AT THIS POINT WITH ENSEMBLE MOISTURE TRANSPORT PLUMES
AS FAR NORTH AS BRITISH COLUMBIA AND AS FAR SOUTH AS NORTHERN
CALIFORNIA. FOR NOW HAVE ADDED A SLIGHT CHANCE OF SHOWERS MAINLY
NORTH AND WEST OF A SOUTH LAKE TAHOE-GERLACH LINE MONDAY INTO
TUESDAY OF NEXT WEEK. TEMPERATURES WILL REMAIN MILD AND SNOW LEVELS
FAIRLY HIGH BEING ON THE SOUTH SIDE OF THE JET. DJ
AVIATION...
SCATTERED SHOWERS WILL PERSIST THROUGH THIS EVENING ACROSS THE
SIERRA AND NORTHERN NEVADA BRINGING PERIODS OF MVFR-IFR CIGS/VIS.
TEMPERATURES HAVE WARMED ENOUGH TO KEEP PRECIPITATION AS RAIN AT ALL
TERMINALS, BUT ICING IS A CONCERN ALOFT. IN ADDITION, THERE IS
WIDESPREAD MOUNTAIN OBSCURATION ACROSS THE REGION.
GUSTY WESTERLY WINDS HAVE DEVELOPED THIS AFTERNOON, BUT ARE ONLY
SURFACING IN SOME LOCATIONS, LIKELY RELATED TO WHERE SHOWERS ARE
LOCATED. BE PREPARED FOR THE POSSIBILITY OF GUSTY WINDS UP TO 20 KTS
IN WESTERN NEVADA.
FOG IS UNLIKELY TO DEVELOP TONIGHT DUE TO LINGERING CLOUDS, BUT IF
CLEARING OCCURS BY MORNING, FOG IS POSSIBLE IN SHELTERED VALLEYS,
INCLUDING AT KTRK. CHANCES ARE ABOUT 15 PERCENT. DJ
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
219 PM PST MON JAN 26 2015
.SYNOPSIS...A WEAK STORM OVER SOUTHERN CALIFORNIA WILL SPREAD HIGH
CLOUDS OVER THE BAY AREA TONIGHT WITH A CHANCE OF SHOWERS FOR THE
CENTRAL COAST OVERNIGHT INTO TUESDAY MORNING. THE SYSTEM WILL MOVE
EASTWARD BY TUESDAY NIGHT WITH DRY AND MILD WEATHER FORECAST WEDNESDAY
THROUGH FRIDAY. A WARMING TREND IS FORECAST OVER THE WEEKEND AS
HIGH PRESSURE STRENGTHENS.
&&
.DISCUSSION...AS OF 2:19 PM PST MONDAY...TEMPERATURES IN THE BAY
AREA ARE TRENDING SLIGHTLY WARMER THIS AFTERNOON DUE TO LESS FOG
COVERAGE THIS MORNING. FARTHER SOUTH TEMPERATURES ALONG THE
CENTRAL COAST ARE MUCH COOLER AFTER YESTERDAYS RECORD WARMTH...AS
HIGH CLOUDS NOW BLANKET THE REGION IN ASSOCIATION WITH THE
CIRCULATION LOCATED WEST OF SAN DIEGO. RIGHT NOW SOME RAIN IS
FALLING IN THE DESERTS OF SOUTHERN CALIFORNIA WITH 29 PALMS AND
CHINA LAKE REPORTING LIGHT RAIN LAST HOUR. ITS AN UNUSUAL SET-UP
BUT ITS THE MOISTURE TO OUR SOUTH THAT WILL BE ADVECTED NORTHWARD
OVER THE NEXT 12-18 HOURS. LATEST MODELS CONTINUE TO KEEP BEST
CHANCES OF PRECIP EAST OF OUR DISTRICT BUT SOME OF THE MESO-SCALE
MODELS PAINT SOME SHOWERS OVER THE HILLS OF MONTEREY AND SAN
BENITO COUNTY AROUND SUNRISE TUESDAY AS THE SYSTEM BEGINS TO EJECT
INLAND. IN PARTICULAR THE LATEST RAP MODEL RUNS HAVE TRENDED
WETTER OVER MONTEREY/SAN BENITO COUNTY TUESDAY MORNING. HAVE LEFT
SHOWER CHANCES IN THE FORECAST TO ACCOUNT FOR THIS. ANY SHOWER
THREAT SHOULD END BY TUESDAY AFTERNOON AS THE MAIN UPPER LOW MOVES
EASTWARD.
AS THAT LOW MOVES TO OUR EAST THE SYNOPTIC PATTERN REMAINS FAIRLY
NONDESCRIPT WITH WEAK CYCLONIC FLOW ALOFT THAT MAY GENERATE SOME
SHOWERS OVER THE SIERRA BY THURSDAY BUT NO PRECIP FOR THE BAY
AREA. OUR TEMPERATURES WILL TREND SLIGHTLY ABOVE NORMAL WITH
AFTERNOON HIGHS IN THE 60S THROUGH THE WORK-WEEK.
ANOTHER WARM WEEKEND LOOKS TO BE IN STORE AS A RIDGE BUILDS
SATURDAY AND SUNDAY WITH 850 MB TEMPS TO AROUND 15 CELSIUS. DOESN`T
LOOK AS WARM AS LAST WEEKEND SO NOT EXPECTING ANY RECORDS.
THE PATTERN BEYOND SUNDAY BECOMES MORE MUDDLED. THE ECMWF AND GEM
MODEL ARE ACTUALLY TRENDING A LITTLE WETTER WHILE THE GFS REMAINS
DRY. GIVEN THE HISTORIC DRY PATTERN WERE UNDER WILL NOT BE
INTRODUCING DAY 7 POPS AT THIS TIME.
&&
.AVIATION...AS OF 9:50 AM PST MONDAY...PATCHY FOG IN THE VALLEYS
WILL CLEAR BY LATE MORNING. A WEAK WEATHER SYSTEM MOVING INTO
SOUTHERN CALIFORNIA WILL SPREAD CONSIDERABLE MID AND HIGH LEVEL
CLOUDS ACROSS THE REGION THROUGH TUESDAY. MOSTLY VFR CONDITIONS
ARE EXPECTED EXCEPT LOCAL IFR CONDITIONS IN FOG IN THE VALLEYS
LATE MONDAY NIGHT AND EARLY TUESDAY. WINDS WILL BE LIGHT
EASTERLY...TRANSITIONING TO LIGHT WESTERLY THIS AFTERNOON AND
LIGHT SOUTHERLY TONIGHT.
VICINITY OF KSFO...VFR. LIGHT OFFSHORE WINDS WINDS THIS MORNING
BECOMING LIGHT VARIABLE THIS AFTERNOON.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR. LIGHT WINDS.
&&
.MARINE...AS OF 1:49 PM PST MONDAY...EAST WINDS OVER THE COASTAL
WATERS WILL TURN TO THE SOUTHEAST LATER TODAY AND TONIGHT AS WEAK
LOW PRESSURE DEVELOPS OFFSHORE. HIGH PRESSURE WILL BUILD OFF THE
NORTHERN CALIFORNIA COAST BY MIDWEEK...RESULTING IN LIGHT TO
MODERATE NORTHWEST WINDS DURING THE SECOND HALF OF THE WEEK.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...NONE.
$$
PUBLIC FORECAST: RWW
AVIATION/MARINE: DYKEMA
VISIT US AT WEATHER.GOV/SANFRANCISCO
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AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
850 AM PST MON JAN 26 2015
.SYNOPSIS...
A LOW PRESSURE SYSTEM FROM THE SOUTHWEST WILL BRING SOME LIGHT
SHOWERS AND SPRINKLES THIS MORNING...WITH INCREASE SHOWERS LATE IN
THE AFTERNOON AND EVENING OVER SOUTHERN CALIFORNIA. BEST RAINFALL
AMOUNTS WILL LIKELY OCCUR IN THE MOUNTAINS...DESERTS AND VALLEYS. A
FEW TO SEVERAL INCHES OF SNOW POSSIBLE IN THE MOUNTAINS ABOVE 7500
FOOT ELEVATION WITH THIS SYSTEM. SHOWERS DISSIPATING QUICKLY
TUESDAY...WITH SLIGHTLY WARMER WEATHER AND BETTER SUNSHINE FOR
WEDNESDAY. ANOTHER WEAK LOW PRESSURE SYSTEM FROM THE SOUTHWEST WILL
BRING A CHANCE OF SHOWERS THURSDAY INTO THE WEEKEND.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
SOME WEAK OFFSHORE FLOW IS STILL OCCURRING THIS MORNING...WITH SOME
LOCAL GUSTS IN THE 30-40 MPH RANGE. OFFSHORE PRESSURE GRADIENTS ARE
CURRENTLY DOWN TO 8.2 MB FROM SAN DIEGO TO TONOPAH...WHEREAS THEY
WERE 12.2 MB 24 HOURS AGO. EXPECT WEAK OFFSHORE WINDS TO CONTINUE
TODAY AS THE OFFSHORE PRESSURE GRADIENT WEAKENS FURTHER...WITH SOME
WARMER THAN NORMAL TEMPERATURES POSSIBLE AT THE COAST DESPITE THE
INCREASED CLOUD COVER.
CURRENT WATER VAPOR IMAGERY SHOWS A DEFORMATION ZONE STRETCHING FROM
OFF THE COAST OF CENTRAL CALIFORNIA INTO SOUTHERN CALIFORNIA AND
ARIZONA...WITH A CUT-OFF UPPER LEVEL LOW TO THE SOUTHWEST OF SAN
DIEGO AND AN UPPER RIDGE TO THE NORTHEAST. IT IS EVIDENT THAT THE
LOW IS SPINNING UP MOISTURE INTO THE AREA FROM THE SOUTHEAST THIS
MORNING...BUT MOST OF IT IS IN THE MID AND HIGH LEVELS OF THE
ATMOSPHERE. ACCORDING TO THE 12Z MIRAMAR SOUNDING...MOST OF THE
MOISTURE IS ABOVE 550 MB...AND SO THE ONLY PLACES THAT HAVE REPORTED
MEASURABLE RAINFALL HAVE BEEN MAINLY IN THE HIGHER ELEVATIONS OF THE
MOUNTAINS DUE TO THE RAIN NOT HAVING AS MUCH TIME TO EVAPORATE IN
THE DRY LOW LAYERS BEFORE REACHING THE SURFACE. THE LOW IS STILL ON
TRACK TO MOVE NORTH AND WEAKEN TODAY AND THEN DEVELOP INTO AN OPEN
WAVE AS IT MOVES INTO SOUTHERN CALIFORNIA TONIGHT...BEFORE MOVING
OUT OF THE AREA ON TUESDAY. AS MORE MOISTURE STREAMS IN FROM THE
SOUTHEAST...EVENTUALLY THE LOWER LAYERS WILL SATURATE AS
WELL...RESULTING IN BETTER RAINFALL ACCUMULATIONS PARTICULARLY FOR
THE LOW ELEVATIONS. RADAR IMAGERY SHOWS MOSTLY LIGHT RETURNS
ASSOCIATED WITH THE AFOREMENTIONED DEFORMATION ZONE OVER THE
NORTHERN PORTIONS OF THE FORECAST AREA...WITH SOME LIGHT
SHOWERS/SPRINKLES MOVING UP FROM SOUTH OF THE BORDER. RAINFALL
AMOUNTS FOR THE MOUNTAINS ARE EXPECTED TO RANGE FROM ONE HALF TO ONE
INCH WITH LOCALLY GREATER AMOUNTS WITH ONE THIRD INCH OR LESS IN THE
DESERTS AND INLAND VALLEYS WITH LESSER AMOUNTS TOWARD THE COAST. THE
13Z HRRR COMPOSITE REFLECTIVITY INITIALIZED WELL...AND ACTUALLY
SHOWS THE FORECAST AREA REMAINING MOSTLY DRY THROUGH EARLY AFTERNOON
BEFORE THE MAIN AREA OF PRECIPITATION MOVES INTO THE AREA FROM THE
SOUTH THIS EVENING. IT IS ALSO INTERESTING TO NOTE THAT THE CANSAC
WRF...LOCAL WRF AND NAM4 HAVE ALL NOTICEABLY BACKED OFF ON THE
RAINFALL AMOUNTS WITH THIS SYSTEM COMPARED TO WHAT THEY SHOWED
YESTERDAY. THUS...THE CURRENT POPS AND QPF MAY BE OVERDONE. THE WARM
NATURE OF THE STORM WILL KEEP SNOW LEVELS HIGH...FALLING TO
7500-8000 FEET THIS EVENING...WITH A FEW TO SEVERAL INCHES OF SNOW
POSSIBLE ABOVE THOSE ELEVATIONS. A WINTER WEATHER ADVISORY HAS BEEN
ISSUED FOR THE SAN BERNARDINO AND RIVERSIDE COUNTY MOUNTAINS ABOVE
7500 FOOT ELEVATION. FINALLY...LOOKING AT THE BUFKIT FORECAST
SOUNDINGS FROM LOCAL WRF AND NAM4...DO NOT SEE MUCH IN THE WAY OF
INSTABILITY. HOWEVER...WITH A VORT MAX MOVING THROUGH THIS EVENING
IN COINCIDENCE WITH SOME COLD AIR ALOFT ASSOCIATED WITH THE LOW...A
LIGHTNING STRIKE OR TWO AND SOME HEAVIER DOWNPOURS CANNOT BE RULED
OUT...PARTICULARLY FOR THE COASTAL WATERS AND COAST.
SHOWERS WILL DISSIPATE QUICKLY TUESDAY MORNING AS THE TROUGH MOVES
NORTH OF THE AREA. WITH THE CONTINUED CLOUD COVER AND LOWER 850 MB
TEMPERATURES...THERE SHOULD BE SOME COOLING FOR TUESDAY. SLIGHTLY
WARMER WITH BETTER SUNSHINE ON WEDNESDAY WITH SOME WEAK HIGH
PRESSURE ALOFT MOVING OVER THE REGION. THEN MODELS CONTINUE TO SHOW
ANOTHER TROUGH MOVING INLAND OVER SOUTHERN CALIFORNIA THURSDAY AND
FRIDAY...MOVING SOUTHEAST ACROSS SOUTHEAST CALIFORNIA/ARIZONA/BAJA
MEXICO SATURDAY...AND THEN SOUTH INTO LOWER BAJA MEXICO ON SUNDAY.
MODELS DIFFER AS TO THE AMOUNT OF MOISTURE AND PRECIPITATION...WITH
THE 12Z GFS MOSTLY DRY...AND THE 00Z ECMWF SOMEWHAT WET. WITH LOW
CONFIDENCE DUE TO THESE DIFFERENCES...THE SLIGHT CHANCE TO CHANCE
OF SHOWERS CURRENTLY IN THE FORECAST FOR THAT TIME SEEM REASONABLE.
&&
.AVIATION...
261630Z...BKN-OVC080-120 LOWERING TO 050-080 THIS AFTERNOON AND
EVENING WITH INCREASING CHANCES FOR LIGHT SHOWERS. RAIN SHOWERS WILL
BE MOST WIDESPREAD OVER THE MOUNTAINS AND DESERTS FROM 22-06Z...WITH
LCL OVC040-060 IN HEAVIER SHOWERS. SHOWERS MOVING FROM SOUTH TO
NORTH OVERNIGHT AND ENDING EARLY TUESDAY.
&&
.MARINE...
830 AM...THERE IS A SLIGHT CHANCE FOR A THUNDERSTORM OVER THE
COASTAL WATERS LATE THIS AFTERNOON AND EVENING.
TUESDAY THROUGH FRIDAY...NO HAZARDOUS MARINE WEATHER IS EXPECTED
THROUGH FRIDAY.
&&
.SKYWARN...
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO MIDNIGHT PST
TONIGHT ABOVE 7500 FEET FOR THE SAN BERNARDINO COUNTY
MOUNTAINS.
PZ...NONE.
&&
$$
PUBLIC...HARRISON
AVIATION/MARINE...MOEDE
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
940 PM PST SUN JAN 25 2015
...AVIATION DISCUSSION UPDATED...
.SYNOPSIS...
TWO LOW PRESSURE SYSTEMS WILL IMPACT SOUTHWESTERN CALIFORNIA THIS
WEEK. THE FIRST SYSTEM WILL MOVE THROUGH THE REGION MONDAY AFTERNOON
THROUGH TUESDAY WITH CHANCES OF RAIN IN ALL AREAS. THE SECOND SYSTEM
IS EXPECTED THURSDAY NIGHT THROUGH SATURDAY MORNING WITH POSSIBLE
PRECIPITATION FOR THE VENTURA AND LOS ANGELES COUNTY MOUNTAINS AND
ANTELOPE VALLEY. OTHERWISE...VARYING AMOUNTS OF CLOUDS AND NEAR
SEASONAL TEMPERATURES CAN BE EXPECTED ACROSS SOUTHWESTERN CALIFORNIA
THROUGH THE WEEK.
&&
.SHORT TERM (TODAY-WED)...EVENING UPDATE...
WE SAW RECORD HEAT TODAY AT A FEW LOCATIONS INCLUDING OXNARD WITH A
HIGH OF 85 BREAKING THE OLD RECORD OF 84 BACK IN 1951 FOR THIS DATE.
ALSO SANTA BARBARA AP TIED THE OLD RECORD AT 79 DEGREES SET A FEW
YEARS BACK IN 2012 AND 1951. LASTLY PASO ROBLES REACHED 78 DEGREES
WHICH WAS A NEW RECORD BREAKING THE OLD RECORD OF 76 DEGREES SET IN
2014. AS FAR AS THE WINDS...THEY HAVE DROPPED OFF RAPIDLY EARLY THIS
EVENING. THE LAX-DAG WAS STILL WEAKLY OFFSHORE BUT TRENDING NEARLY
+4 MB OVER THE LAST 24 HOURS.
THERE WILL BE A MAJOR WEATHER PATTERN CHANGE OVER THE NEXT 24 HOURS
AS A FAIRLY EXPANSIVE UPPER LOW LOCATED AROUND 300 MILES WEST OF
BAJA WILL START TO ROTATE TO THE NORTH AS THE UPPER RIDGE GETS
PUSHED EASTWARD. AS USUAL...MODELS SEEM TO HAVE A TOUGH TIME
HANDLING MANY DETAILS WITH ANY WET SYSTEM MOVING IN FROM THE
SOUTHWEST. ALTHOUGH MOST ALL THE MODELS ARE IN PRETTY GOOD AGREEMENT
BRINGING STEADY LIGHT RAIN OVER THE AREA INITIALLY LATE MONDAY
AFTERNOON OR EARLY EVENING FROM THE SOUTH OVER LA COUNTY AND THEN
PIVOTING NORTH TOWARDS SLO COUNTY BY MONDAY NIGHT. THE BULK OF THE
RAIN WILL REMAIN ACROSS THE INTERIOR SECTIONS OF THE FORECAST AREA
WHILE COASTAL AREAS COULD SEE LESS THAN A TENTH OF AN INCH.
THE LATEST 00Z NAM CONCERNS ME A BIT IN RESPECT TO POSSIBLE ELEVATED
THUNDERSTORMS WITH THE CENTER OF THE LOW MOVING OVER THE COASTAL
WATERS MONDAY NIGHT INTO EARLY TUESDAY MORNING. 500 MB TEMPS LOWER
TO AROUND -22 DEGREES C AND THERE ARE A COUPLE OF RELATIVELY STRONG
VORT MAX`S MOVING OVER THE SO CAL BIGHT. ALSO...LIFTED INDEX VALUES
ARE MORE IMPRESSIVE THAN WOULD THINK WITH THIS UPPER LOW. HAVE RAN
SOME LOCAL FORECAST SOUNDINGS OVER THE SO CAL BIGHT AND COASTAL
AREAS AND EXCEPT FOR THE LACK OF LOW LEVEL MOISTURE...THERE IS SOME
ELEVATED INSTABILITY TO WORK WITH. AT THIS POINT WILL LEAVE QPF
ALONE AND LET THE MID SHIFT LOOK AT LOCAL HIGH RES MODELS TO PICK UP
ON SOME CONVECTIVE AREAS. ONE OTHER INTERESTING NOTE...THERE IS SOME
DECENT LOW LEVEL VEERING WINDS WITH THIS UPPER LOW. SO IF A FEW
STORMS DO DEVELOP OVER THE COASTAL WATERS...THE POSSIBILITY OF
ISOLATED WATERSPOUTS CAN`T BE RULED OUT MONDAY NIGHT INTO TUESDAY
MORNING.
IN RESPECT TO THE REST OF THE FORECAST...IT LOOKS TO BE IN GREAT
SHAPE FOR THE SHORT AND LONG TERM. AGAIN...WILL HAVE THE MID SHIFT
LOOK AT MORE HIGH RES DATA INCLUDING RAP AND HRRR INCLUDING THE
LOCAL 4KM WRF.
***FROM PREVIOUS DISCUSSION***
TONIGHT THROUGH MONDAY MORNING...THE UPPER LOW W OF BAJA WILL START
TO MOVE NW ALONG THE WESTERN FRINGE OF THE UPPER RIDGE...WHILE THE
UPPER RIDGE SHIFTS INTO THE WESTERN U.S. CLOUDS WILL CONTINUE TO
INCREASE ON MONDAY...ALONG WITH THE CHANCE OF SHOWERS AS THE UPPER
LOW STARTS TO MOVE NE TOWARDS SOCAL. POPS WERE INCREASED INTO THE
LIKELY CATEGORY FOR MOST OF LA COUNTY FOR THE MONDAY EVENING TIME
PERIOD...WHICH LOOKS LIKE THE BEST WINDOW FOR MEASURABLE RAIN. WITH
WEAK OFFSHORE FLOW AT THE SURFACE...THE ANTELOPE VALLEY AND THE
NORTH FACING SLOPES OF THE SAN GABRIEL MOUNTAINS WILL LIKELY HAVE
THE HIGHEST RAINFALL AMOUNTS. EXPECTING 0.25"-0.50" OF RAIN IN THESE
AREAS...WITH LIGHTER AMOUNTS W OF THE MOUNTAINS. ANY RAIN SHOWERS
SHOULD BE PRETTY MUCH DONE BY TUESDAY MORNING AS THE UPPER LOW
WEAKENS AND MOVES N. NOT MUCH SNOW EXPECTED WITH THIS SYSTEM...AS
SNOW LEVELS WILL GENERALLY REMAIN ABOVE 7000 FT...WITH LIGHT
ACCUMULATIONS POSSIBLE ABOVE THAT ALTITUDE. NO T-STORMS IN THE
FORECAST AS THEIR WILL BE LITTLE INSTABILITY TO WORK WITH (LESS THAN
500 J/KG OF CAPE OVER THE COASTAL WATERS) AND LIFT ASSOCIATED WITH
THE UPPER LOW WILL BE RELATIVELY WEAK. HOWEVER...WOULDN`T BE TOTALLY
SURPRISED IF THERE IS A T-STORM OR TWO WELL OFF THE COAST ON MONDAY
EVENING.
MAX TEMPS ON MONDAY AND TUESDAY WILL BE MUCH COOLER THAN THEY WERE
OVER THE WEEKEND...WITH NEAR NORMAL HIGHS EXPECTED. WEDNESDAY WILL
BE SEVERAL DEGREES WARMER AS A WEAK RIDGE POPS UP AHEAD OF THE NEXT
TROF OF LOW PRESSURE. WEAK OFFSHORE GRADIENTS AND FEWER CLOUDS WILL
HELP WITH THE WARMING ON WEDNESDAY AS WELL.
.LONG TERM (THU-SUN)...
LATEST MODELS ARE IN FAIRLY GOOD SYNOPTIC AGREEMENT THROUGH NEXT
WEEKEND...BUT WE WILL BE DEALING WITH ANOTHER CUTOFF LOW FRIDAY
THROUGH SUNDAY...SO WE`LL SEE HOW THAT GOES. CURRENT FORECAST HAS A
SLIGHT CHANCE OF SHOWERS FOR THE VENTURA/LA MOUNTAINS AND THE
ANTELOPE VALLEY THURSDAY THROUGH SATURDAY. FORECAST CONFIDENCE IS
RELATIVELY LOW...BUT NOT EXPECTING THIS TO BE A MAJOR RAIN PRODUCER
AT THIS TIME. CURRENT FORECAST ALSO HAS NEAR NORMAL TEMPS FOR
THURSDAY AND FRIDAY...WITH THE UPPER-LEVEL TROUGH OVERHEAD. SLIGHT
WARMING TREND FORECASTED FOR NEXT WEEKEND AS THE UPPER LOW DRIFTS TO
THE SE AND RIDGING/OFFSHORE FLOW DEVELOPS.
&&
.AVIATION...26/06Z...
AT 0520Z AT KLAX... THERE WAS NO INVERSION.
OVERALL...MODERATE CONFIDENCE IN 06Z TAFS. REDUCED CONFIDENCE DUE
TO UNCERTAINTY IN THE TIMING AND INTENSITY OF THE INCOMING
PRECIPITATION AND THE EFFECT ON WIND FLOW AND VSBY. AN INCREASING
CHANCE OF PRECIPITATION ACROSS THE REGION BEGINNING IN LOS ANGELES
COUNTY 22Z-00Z AND MOVING NORTH TOWARD SAN LUIS OBISPO COUNTY BY
06Z. CONDITIONS ARE MOST LIKELY TO REMAIN VFR THROUGH THE FORECAST
PERIOD THOUGH THERE IS A THIRTY PERCENT CHANCE OF MVFR CONDITIONS
AFTER 23Z.
KLAX...MODERATE CONFIDENCE IN 06Z TAF. REDUCED CONFIDENCE DUE TO
UNCERTAINTY IN THE TIMING AND INTENSITY OF THE INCOMING
PRECIPITATION AND THE EFFECT ON WIND FLOW AND VSBY. AN INCREASING
CHANCE OF PRECIPITATION BEGINNING 22Z-00Z. CONDITIONS ARE MOST
LIKELY TO REMAIN VFR THROUGH THE FORECAST PERIOD THOUGH THERE IS A
THIRTY PERCENT CHANCE OF MVFR CONDITIONS AFTER 23Z. A THIRTY
PERCENT CHANCE OF SOUTHEAST TO EAST WINDS GREATER THAN 7 KTS 09Z-18Z.
KBUR...MODERATE CONFIDENCE IN 06Z TAF. REDUCED CONFIDENCE DUE TO
UNCERTAINTY IN THE TIMING AND INTENSITY OF THE INCOMING
PRECIPITATION AND THE EFFECT ON WIND FLOW AND VSBY. AN INCREASING
CHANCE OF PRECIPITATION BEGINNING 22Z-00Z. CONDITIONS ARE MOST
LIKELY TO REMAIN VFR THROUGH THE FORECAST PERIOD THOUGH THERE IS A
THIRTY PERCENT CHANCE OF MVFR CONDITIONS AFTER 23Z.
.MARINE...25/745 PM...
AN AREA OF LOW PRESSURE OFF OF CENTRAL BAJA WILL MOVE NORTH OVER THE
AREA AND SOUTH AND SOUTHEAST WIND GUST TO AROUND 25 KT ARE EXPECTED
MONDAY MORNING AND PERSIST THROUGH THE AFTERNOON. THE STRONGEST
WINDS ARE EXPECTED OVER THE SANTA BARBARA CHANNEL AND SANTA MONICA
BASIN. OTHERWISE...THERE IS A CHANCE FOR SMALL CRAFT ADVISORY
CONDITIONS OVER THE OUTER WATERS THRU THRU FRI AS NORTH WINDS
DEVELOP AND THEN STRENGTHEN.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
&&
$$
PUBLIC...KAPLAN/SUKUP
AVIATION...KJ
MARINE...SIRARD
SYNOPSIS...SIRARD
WWW.WEATHER.GOV/LOSANGELES
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATE
NWS LOS ANGELES/OXNARD CA
810 PM PST SUN JAN 25 2015
.SYNOPSIS...
TWO LOW PRESSURE SYSTEMS WILL IMPACT SOUTHWESTERN CALIFORNIA THIS
WEEK. THE FIRST SYSTEM WILL MOVE THROUGH THE REGION MONDAY AFTERNOON
THROUGH TUESDAY WITH CHANCES OF RAIN IN ALL AREAS. THE SECOND SYSTEM
IS EXPECTED THURSDAY NIGHT THROUGH SATURDAY MORNING WITH POSSIBLE
PRECIPITATION FOR THE VENTURA AND LOS ANGELES COUNTY MOUNTAINS AND
ANTELOPE VALLEY. OTHERWISE...VARYING AMOUNTS OF CLOUDS AND NEAR
SEASONAL TEMPERATURES CAN BE EXPECTED ACROSS SOUTHWESTERN CALIFORNIA
THROUGH THE WEEK.
&&
.SHORT TERM (TODAY-WED)...EVENING UPDATE...
WE SAW RECORD HEAT TODAY AT A FEW LOCATIONS INCLUDING OXNARD WITH A
HIGH OF 85 BREAKING THE OLD RECORD OF 84 BACK IN 1951 FOR THIS DATE.
ALSO SANTA BARBARA AP TIED THE OLD RECORD AT 79 DEGREES SET A FEW
YEARS BACK IN 2012 AND 1951. LASTLY PASO ROBLES REACHED 78 DEGREES
WHICH WAS A NEW RECORD BREAKING THE OLD RECORD OF 76 DEGREES SET IN
2014. AS FAR AS THE WINDS...THEY HAVE DROPPED OFF RAPIDLY EARLY THIS
EVENING. THE LAX-DAG WAS STILL WEAKLY OFFSHORE BUT TRENDING NEARLY
+4 MB OVER THE LAST 24 HOURS.
THERE WILL BE A MAJOR WEATHER PATTERN CHANGE OVER THE NEXT 24 HOURS
AS A FAIRLY EXPANSIVE UPPER LOW LOCATED AROUND 300 MILES WEST OF
BAJA WILL START TO ROTATE TO THE NORTH AS THE UPPER RIDGE GETS
PUSHED EASTWARD. AS USUAL...MODELS SEEM TO HAVE A TOUGH TIME
HANDLING MANY DETAILS WITH ANY WET SYSTEM MOVING IN FROM THE
SOUTHWEST. ALTHOUGH MOST ALL THE MODELS ARE IN PRETTY GOOD AGREEMENT
BRINGING STEADY LIGHT RAIN OVER THE AREA INITIALLY LATE MONDAY
AFTERNOON OR EARLY EVENING FROM THE SOUTH OVER LA COUNTY AND THEN
PIVOTING NORTH TOWARDS SLO COUNTY BY MONDAY NIGHT. THE BULK OF THE
RAIN WILL REMAIN ACROSS THE INTERIOR SECTIONS OF THE FORECAST AREA
WHILE COASTAL AREAS COULD SEE LESS THAN A TENTH OF AN INCH.
THE LATEST 00Z NAM CONCERNS ME A BIT IN RESPECT TO POSSIBLE ELEVATED
THUNDERSTORMS WITH THE CENTER OF THE LOW MOVING OVER THE COASTAL
WATERS MONDAY NIGHT INTO EARLY TUESDAY MORNING. 500 MB TEMPS LOWER
TO AROUND -22 DEGREES C AND THERE ARE A COUPLE OF RELATIVELY STRONG
VORT MAX`S MOVING OVER THE SO CAL BIGHT. ALSO...LIFTED INDEX VALUES
ARE MORE IMPRESSIVE THAN WOULD THINK WITH THIS UPPER LOW. HAVE RAN
SOME LOCAL FORECAST SOUNDINGS OVER THE SO CAL BIGHT AND COASTAL
AREAS AND EXCEPT FOR THE LACK OF LOW LEVEL MOISTURE...THERE IS SOME
ELEVATED INSTABILITY TO WORK WITH. AT THIS POINT WILL LEAVE QPF
ALONE AND LET THE MID SHIFT LOOK AT LOCAL HIGH RES MODELS TO PICK UP
ON SOME CONVECTIVE AREAS. ONE OTHER INTERESTING NOTE...THERE IS SOME
DECENT LOW LEVEL VEERING WINDS WITH THIS UPPER LOW. SO IF A FEW
STORMS DO DEVELOP OVER THE COASTAL WATERS...THE POSSIBILITY OF
ISOLATED WATERSPOUTS CAN`T BE RULED OUT MONDAY NIGHT INTO TUESDAY
MORNING.
IN RESPECT TO THE REST OF THE FORECAST...IT LOOKS TO BE IN GREAT
SHAPE FOR THE SHORT AND LONG TERM. AGAIN...WILL HAVE THE MID SHIFT
LOOK AT MORE HIGH RES DATA INCLUDING RAP AND HRRR INCLUDING THE
LOCAL 4KM WRF.
***FROM PREVIOUS DISCUSSION***
TONIGHT THROUGH MONDAY MORNING...THE UPPER LOW W OF BAJA WILL START
TO MOVE NW ALONG THE WESTERN FRINGE OF THE UPPER RIDGE...WHILE THE
UPPER RIDGE SHIFTS INTO THE WESTERN U.S. CLOUDS WILL CONTINUE TO
INCREASE ON MONDAY...ALONG WITH THE CHANCE OF SHOWERS AS THE UPPER
LOW STARTS TO MOVE NE TOWARDS SOCAL. POPS WERE INCREASED INTO THE
LIKELY CATEGORY FOR MOST OF LA COUNTY FOR THE MONDAY EVENING TIME
PERIOD...WHICH LOOKS LIKE THE BEST WINDOW FOR MEASURABLE RAIN. WITH
WEAK OFFSHORE FLOW AT THE SURFACE...THE ANTELOPE VALLEY AND THE
NORTH FACING SLOPES OF THE SAN GABRIEL MOUNTAINS WILL LIKELY HAVE
THE HIGHEST RAINFALL AMOUNTS. EXPECTING 0.25"-0.50" OF RAIN IN THESE
AREAS...WITH LIGHTER AMOUNTS W OF THE MOUNTAINS. ANY RAIN SHOWERS
SHOULD BE PRETTY MUCH DONE BY TUESDAY MORNING AS THE UPPER LOW
WEAKENS AND MOVES N. NOT MUCH SNOW EXPECTED WITH THIS SYSTEM...AS
SNOW LEVELS WILL GENERALLY REMAIN ABOVE 7000 FT...WITH LIGHT
ACCUMULATIONS POSSIBLE ABOVE THAT ALTITUDE. NO T-STORMS IN THE
FORECAST AS THEIR WILL BE LITTLE INSTABILITY TO WORK WITH (LESS THAN
500 J/KG OF CAPE OVER THE COASTAL WATERS) AND LIFT ASSOCIATED WITH
THE UPPER LOW WILL BE RELATIVELY WEAK. HOWEVER...WOULDN`T BE TOTALLY
SURPRISED IF THERE IS A T-STORM OR TWO WELL OFF THE COAST ON MONDAY
EVENING.
MAX TEMPS ON MONDAY AND TUESDAY WILL BE MUCH COOLER THAN THEY WERE
OVER THE WEEKEND...WITH NEAR NORMAL HIGHS EXPECTED. WEDNESDAY WILL
BE SEVERAL DEGREES WARMER AS A WEAK RIDGE POPS UP AHEAD OF THE NEXT
TROF OF LOW PRESSURE. WEAK OFFSHORE GRADIENTS AND FEWER CLOUDS WILL
HELP WITH THE WARMING ON WEDNESDAY AS WELL.
.LONG TERM (THU-SUN)...
LATEST MODELS ARE IN FAIRLY GOOD SYNOPTIC AGREEMENT THROUGH NEXT
WEEKEND...BUT WE WILL BE DEALING WITH ANOTHER CUTOFF LOW FRIDAY
THROUGH SUNDAY...SO WE`LL SEE HOW THAT GOES. CURRENT FORECAST HAS A
SLIGHT CHANCE OF SHOWERS FOR THE VENTURA/LA MOUNTAINS AND THE
ANTELOPE VALLEY THURSDAY THROUGH SATURDAY. FORECAST CONFIDENCE IS
RELATIVELY LOW...BUT NOT EXPECTING THIS TO BE A MAJOR RAIN PRODUCER
AT THIS TIME. CURRENT FORECAST ALSO HAS NEAR NORMAL TEMPS FOR
THURSDAY AND FRIDAY...WITH THE UPPER-LEVEL TROUGH OVERHEAD. SLIGHT
WARMING TREND FORECASTED FOR NEXT WEEKEND AS THE UPPER LOW DRIFTS TO
THE SE AND RIDGING/OFFSHORE FLOW DEVELOPS.
&&
.AVIATION...26/0050Z...
AT 0030Z THERE WAS NO INVERSION AT KLAX.
MODERATE CONFIDENCE WITH 00Z TAFS. OVERALL EXPECT INCREASING VFR
CLOUD CONDS OVER THE NEXT 24 HOURS ACROSS THE ENTIRE FORECAST AREA.
THERE WILL BE A 30 PERCENT CHANCE FOR MVFR CIGS AFTER 19Z FOR LOS
ANGELES COUNTY. EXPECT INCREASING CHANCE FOR SHOWERS BY MONDAY NIGHT
INITIALLY FROM LOS ANGELES COUNTY...THEN WORKING NORTH INTO SAN LUIS
OBISPO COUNTY MONDAY NIGHT.
KLAX...MODERATE TO HIGH CONFIDENCE WITH 00Z TAF. EXPECT VFR CLOUD
COVER OVER NEXT 24 HOURS. 30 PERCENT CHANCE FOR MVFR CIGS TO DEVELOP
AFTER 19Z. 20 PERCENT CHANCE FOR 50 PERCENT CHANCE FOR -RA BY 23Z
MONDAY. 30 PERCENT THAT SE-E WIND DIRECTION WILL BE OVER 7 KTS
BETWEEN 09Z-18Z.
KBUR...MODERATE TO HIGH CONFIDENCE WITH 00Z TAF. EXPECT VFR CLOUD
COVER OVER NEXT 24 HOURS. 30 PERCENT CHANCE FOR MVFR CIGS TO DEVELOP
AFTER 19Z. 20 PERCENT CHANCE FOR 50 PERCENT CHANCE FOR -RA BY 23Z
MONDAY. NOT ANTICIPATING ANY WIND ISSUES OVER NEXT 24 HOURS.
.MARINE...25/745 PM...
AN AREA OF LOW PRESSURE OFF OF CENTRAL BAJA WILL MOVE NORTH OVER THE
AREA AND SOUTH AND SOUTHEAST WIND GUST TO AROUND 25 KT ARE EXPECTED
MONDAY MORNING AND PERSIST THROUGH THE AFTERNOON. THE STRONGEST
WINDS ARE EXPECTED OVER THE SANTA BARBARA CHANNEL AND SANTA MONICA
BASIN. OTHERWISE...THERE IS A CHANCE FOR SMALL CRAFT ADVISORY
CONDITIONS OVER THE OUTER WATERS THRU THRU FRI AS NORTH WINDS
DEVELOP AND THEN STRENGTHEN.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
&&
$$
PUBLIC...KAPLAN/SUKUP
AVIATION...KAPLAN
MARINE...SIRARD
SYNOPSIS...SIRARD
WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
912 PM CST TUE JAN 27 2015
.UPDATE...
905 PM CST
LOW CLOUD COVER CONTINUES TO SLOWLY MOVE WESTWARD AND HAS CLEARED
ALL BUT THE WESTERN FRINGES OF THE FORECAST AREA THIS EVENING.
SATELLITE SHOWS SOME HIGHER CLOUD STREAKS APPROACHING FROM THE
NORTHWEST AS UPPER RIDGING SHIFTS EASTWARD BUT COVERAGE LOOKS
LOOKS TO BE SPORADIC THROUGH THE NIGHT AND MAY BE AT A MINIMUM
DURING THE EARLY OVERNIGHT. TEMPERATURES HAVE BEGUN TO DROP OFF
WHERE THANKS TO THE MAINLY CLEAR SKIES WITH SEVERAL SITES IN
NORTH-CENTRAL ILLINOIS NOW IN THE TEENS. GIVEN THAT HIGHER CLOUD
COVER LOOKS INTERMITTENT AND WINDS WILL DROP OFF WITH HIGH
PRESSURE MOVING OVERHEAD HAVE GONE AHEAD AND LOWERED MINS
OVERNIGHT FOR MOST AREAS...THOUGH WESTERN FRINGES MAY SEE LOWER
LEVEL CLOUD COVER LINGER THROUGH THE NIGHT. WILL GO WITH LOWER
TEENS FOR MUCH OF THE WESTERN/CENTRAL CWA AND SOME OF THE
TRADITIONALLY COLDER SPOTS FROM LEE/OGLE COUNTIES TO DEKALB AND
KANE COUNTIES COULD SEE VALUES A LITTLE BIT LOWER IF HIGH CLOUD
COVER REMAINS VERY MINIMAL.
WITH THE LOWER TEMPS AND SPORADIC HIGHER CLOUD COVER...FREEZING
FOG WILL BE A CONCERN. THE COLDEST AREAS WILL LIKELY SEE A QUICK
DROP OFF IN THE NEXT FEW HOURS WHICH MAY LEAD TO MORE FROST
DEPOSITION RATHER THAN FOG FORMATION. WITH LIMITED CONFIDENCE IN
THIS HAPPENING AND REASONABLE SUPPORT FOR SOME FOG
DEVELOPMENT...WILL GO AHEAD AND ADD PATCHY FOG TO MUCH OF THE
CENTRAL AND WESTERN CWA OR FROM THE FAR WESTERN CHICAGO METRO WEST
AND SOUTHWEST FOR NOW. THIS MAY CAUSE SOME SLICK SPOTS ON ROADS
OVERNIGHT.
MDB
&&
.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 03Z...
* GUSTY SSELY WINDS TOMORROW.
* CHANCE FOR MVFR CIGS OR VIS LATE TONIGHT.
KREIN
//DISCUSSION...UPDATED 00Z...
THE DECK OF MVFR STRATOCU CONTINUES TO ERODE FROM EAST TO WEST PER
LATEST SATELLITE IMAGERY. RFD REMAINS THE ONLY TAF SITE STILL WITH
MVFR CIGS AND IS JUST WEST OF THE EDGE OF THE CLEARING SKIES. THE
EDGE OF THE CLEARING APPEARS TO HAVE SLOWED WITH THE SETTING
SUN...SO HAVE DELAYED IMPROVEMENT OF CIGS THERE UNTIL 04Z...BUT
THE CONFIDENCE IN THE EXACT TIMING IS LOW. AS HIGH PRESSURE
SETTLES OVER THE AREA TONIGHT...WINDS WILL DROP OFF TO
LGT/VRBL...AND WITH THE DECREASING CLOUD COVER...THERE SHOULD BE
ENOUGH RADIATIVE COOLING FOR TEMPERATURES TO DROP LOW ENOUGH OVER
RURAL AREAS TO ALLOW FOR SOME AREA OF BR DEVELOPMENT WITH VIS
DROPPING INTO THE 3-5SM RANGE. ORD/MDW/GYY WILL LIKELY REMAIN VFR
DUE TO URBAN HEAT ISLAND EFFECTS PREVENTING TEMPERATURES FROM
DROPPING OFF AS MUCH.
THE MAIN CONCERN FOR TOMORROW WILL BE WINDS. AS THE HIGH SETTLES
TO THE SOUTH AND LOW PRESSURE TRACKS EWD ACROSS THE CNTRL
PLAINS...A STRENGTHENING SOUTHERLY GRADIENT WILL SET UP...WITH
WINDS INCREASING BY LATE MORNING. THERE SHOULD BE ADEQUATE
SUNSHINE TO ALLOW FOR STRONGER WINDS ABOVE THE SFC TO MIX
DOWN...WITH GUSTS IN THE 20-25KT RANGE LIKELY THROUGH THE
AFTERNOON. THE LOW PRESSURE SYSTEM TRACKING ACROSS THE PLAINS
SHOULD BRING THE NEXT CHANCE FOR PCPN AND REDUCED CIGS/VIS...BUT
THIS WILL LIKELY NOT BE UNTIL AFTER MIDNIGHT TOMORROW NIGHT.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* MEDIUM CONFIDENCE IN CIGS/VIS TRENDS.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...CHANCE OF RAIN/SNOW. MVFR LIKELY/IFR POSSIBLE.
FRIDAY...VFR. WX NIL.
SATURDAY...CHANCE OF SNOW IN THE AFTERNOON AND OVERNIGHT. VFR
EARLY THEN MVFR LIKELY/IFR POSSIBLE.
SUNDAY...CHANCE OF SNOW. IFR POSSIBLE.
MONDAY...VFR. WX NIL.
KREIN
&&
.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:
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[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
639 PM CST Tue Jan 27 2015
.UPDATE...
ISSUED AT 639 PM CST TUE JAN 27 2015
Made some quick updates to the forecast this evening, mainly to
better reflect current and expected sky trends. 00z/6pm IR
satellite imagery shows cloud cover steadily eroding from the
E/NE, with mostly clear skies currently noted along/northeast of a
Champaign to Paris line. Clouds are beginning to break up south of
there along/south of the I-70 corridor as well. Based on satellite
loops and the latest HRRR forecast, it appears skies will become
partly to mostly clear across much of the KILX CWA tonight, except
perhaps the far NW around Galesburg. Will continue to monitor
trends to see if additional updates are needed, but for now will
hold on to overcast conditions through the entire night northwest
of the Peoria area with clearing skies elsewhere. Low temperatures
will be coldest where clearing has already occurred across the NE
CWA around Danville, where readings will dip into the teens. Lower
to middle 20s seem reasonable across the rest of central Illinois.
&&
.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 00Z TAFS through 00Z Wednesday evening)
ISSUED AT 547 PM CST TUE JAN 27 2015
Main aviation challenges are the current MVFR ceilings and timing
the clearing trend tonight. Latest satellite imagery continues to
show the cloud cover eroding from the E/NE, with mostly clear
skies now being reported along/northeast of a KCMI to KPRG line.
HRRR suggests the clouds will continue to slowly dissipate over
the next several hours, with clear skies across the board by
shortly after midnight. Based on satellite trends and HRRR, have
removed the ceiling from KCMI by 01z, then further west to KPIA by
around 07z. Winds will initially be quite light from the N/NE this
evening, then will veer to E/SE overnight. As the pressure
gradient tightens across the region, SE winds will increase
markedly on Wednesday. Forecast soundings and numeric guidance
suggest gusts in the 20 to 25kt range from late morning through
the afternoon hours. Other than high/thin cirrus clouds, skies
will be mostly clear through 00z.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Barnes
SHORT TERM...kmd
LONG TERM...RC
AVIATION...Barnes
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
200 PM CST MON JAN 26 2015
.SHORT TERM...
315 AM CST
THROUGH TONIGHT...
AN IMPRESSIVE WATER VAPOR LOOP THIS MORNING AS ROARING SUBTROPICAL
JET ACROSS THE SOUTHEAST IS DEEPENING A SIGNIFICANT SYSTEM THAT WILL
IMPACT THE NORTHEAST U.S. OVER THE NEXT 24 TO 36 HOURS. THE NORTHERN
STREAM JET WHICH IS ALSO HELPING TO CARVE OUT THE DEVELOPING TROUGH
IS DIVING SOUTHWARD OVER OUR REGION TODAY. ON THE CYCLONIC SIDE OF
THIS...FROM MANITOBA TO THE LOWER OHIO VALLEY...AN ELONGATED AREA OF
VORTICITY GENERATION WILL SUPPORT FORCING FOR ASCENT TODAY AND
TONIGHT...WITH THE MOST FOCUSED ZONE BEING A BETTER DEFINED WAVE
SEEN OVER CENTRAL MN EARLY THIS MORNING. THE RUN-TO-RUN TREND ON THE
RAP MODEL EARLY THIS MORNING IS FURTHER
WEST/SOUTHWEST...SUPPORTING UPSTREAM RADAR TRENDS AND FAVORING
NORTH CENTRAL IL TO GET IN A PERIOD OF SNOW BEGINNING LATER THIS
MORNING FOLLOWED BY A GRADUAL EXPANSION EAST. WHILE MOST OF THE
SNOW WILL BE LIGHT...THERE IS A WINDOW OF TIME LATE THIS MORNING
AND EARLY THIS AFTERNOON OVER NORTH CENTRAL ILLINOIS WHERE
850-700MB CONVERGENCE AND A F-GEN INDUCED CIRCULATION MAY ALLOW
FOR SPOTTY BURSTS OF MODERATE SNOW...WHICH HIGH-RESOLUTION
GUIDANCE TRIES TO INDICATE TOO. WITH ADJACENT OFFICES AND WPC
COLLABORATION...HAVE AROUND AN INCH FORECAST IN THE ROCKFORD
AREA...WITH AROUND A HALF INCH FURTHER EAST OF THERE. SOUTHWARD IN
THE FORECAST AREA THE DRY AIR SEEMS MORE PRONOUNCED...SO MAY END
UP JUST BEING FLURRIES AT TIMES.
THE FORCING ALOFT WEAKENS LATER THIS AFTERNOON AND EVENING SO
EXPECTING LIGHT SNOW TO BECOME MORE PATCHY IN COVERAGE. THE MOISTURE
IN THE ICE LAYER GRADUALLY DIMINISHES FROM WEST TO EAST THROUGH THE
EVENING...WITH STILL SOME LIGHT ADIABATIC ASCENT IN THE LOWEST
COUPLE THOUSAND FEET. IF THAT LOWEST LAYER IS SATURATED OR ABLE TO
THERE COULD BE A FREEZING DRIZZLE CONCERN...SO MAINTAIN THE GOING
CHANCE IN THE FORECAST.
FOR TEMPERATURES TODAY...DID BUMP DOWN SEVERAL DEGREES AS CLEARING
LAST NIGHT ALLOWED PLACES TO DROP QUICKLY AND NOW THE CLOUD CANOPY
WILL HINDER THEM FROM WARMING MUCH. FORECAST HIGHS ARE MAINLY IN THE
MID 20S WITH A FEW UPPER 20S POSSIBLE. WHILE THAT DOES NOT MAKE
HEADLINES IN JANUARY...IF THE FORECAST PANS OUT THIS WOULD BE THE
FIRST DAY WITH HIGHS BELOW 30 SINCE JANUARY 14TH.
MTF
&&
.LONG TERM...
315 AM CST
TUESDAY THROUGH SUNDAY...
HIGH PRESSURE WILL MOVE OVER THE AREA TUESDAY AFTERNOON AND NIGHT
BEFORE RETURN FLOW ON WEDNESDAY. THE CHALLENGE OF CLOUD COVER
PRESENTS ITSELF AGAIN ON TUESDAY AND WHILE HAVE SLOWED THE
CLEARING TREND TUESDAY MORNING...STILL THINK THE AFTERNOON SHOULD
SEE SOME BREAKS OF SUN AREAWIDE. SOUTHERLY FLOW ON WEDNESDAY IS
FORECAST TO BRING 925MB TEMPERATURES TO AROUND 0C WHICH USING
CLIMATOLOGY WITH LIMITED SNOW COVER SHOULD SUPPORT WIDESPREAD MID
TO UPPER 30S WITH A FEW LOWER 40S POSSIBLE IN THE SOUTHWEST CWA
OR CHICAGO METRO.
THE LARGE CLOSED LOW OFF THE BAJA OF CALIFORNIA THIS MORNING IS
FORECAST BY THE SUITE OF GUIDANCE TO DRIFT NORTHWARD AND GET CAUGHT
UP IN THE WESTERLIES BECOMING AN OPEN WAVE ACROSS THE MIDDLE OF THE
COUNTRY. WITH THE MASSIVE SYSTEM OFF THE NORTHEAST LIKELY TO SLOW
THINGS A BIT...CONTINUE TO LEAN WITH THE SLOWER EC AND GEM MODELS
WHICH WOULD FAVOR PRECIPITATION CHANCES MORE SO LATE WEDNESDAY NIGHT
AND THURSDAY...AROUND 12H SLOWER THAN THE GFS. FORECAST VERTICAL
PROFILES ON BOTH MODELS WOULD SUPPORT MORE OF RAIN AHEAD OF THIS
SYSTEM...ESPECIALLY CONSIDERING LOW-LEVEL TEMPERATURES SHOULD AT THE
VERY LEAST HOLD STEADY IF NOT MODERATE WEDNESDAY NIGHT...POTENTIALLY
TO 35 TO 38 DEGREES GIVEN EC AND GEM SOLUTIONS. ON THE BACKSIDE OF
THIS SYSTEM IT WOULD SEEM THERE WOULD BE AT LEAST A PERIOD OF SNOW
CHANCES. OBVIOUSLY A FEW DAYS OUT AND A CUTOFF LOW INVOLVED...A
LOT COULD CHANGE WITH SPECIFICS...BUT RIGHT NOW THIS IS NOT
LOOKING LIKE A HIGH IMPACT EVENT.
LATE THIS WEEK INTO THE WEEKEND THE NORTHERN STREAM FLOW PATTERN
IS FORECAST TO REMAIN QUITE PROGRESSIVE WHILE ANOTHER CUTOFF LOW
IS PROGGED TO DEVELOP OVER THE FAR SOUTHWEST US. THE 00Z EC HAS
FORECAST A STRONG SYSTEM IN THE NORTHWEST FLOW TO WIN OUT ABOUT A
WEEK FROM NOW AND DRAG DOWN -15C TO -20C 850MB TEMPERATURES.
SOMETHING TO MONITOR AS WE HEAD TOWARD THE FIRST DAYS OF FEBRUARY.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SNOW THIS AFTERNOON WITH MVFR CONDITIONS AND TEMPO IFR...AND
LIGHT ACCUMULATIONS LESS THAN AN INCH.
* SNOW TAPERING THIS EVENING AND POSSIBLY TRANSITIONING TO OR
MIXING WITH DRIZZLE.
BMD
//DISCUSSION...UPDATED 18Z...
SHEARED UPPER LEVEL DISTURBANCE IS HELPING TO DRIVE AN AREA OF SNOW
ACROSS ILLINOIS AND WISCONSIN EARLY THIS AFTERNOON. THIS SNOW IS
EXPECTED TO MOVE INTO THE CHICAGO AREA OVER THE NEXT COUPLE HOURS.
INITIALLY DRY LOW/MID LEVELS WILL TAKE THEIR TIME TO SATURATE AS THE
RADAR RETURNS MOVE OVERHEAD...PRECIPITATION INITIALLY EVAPORATING IN
THE DRY AIR...BUT THEN EXPECT CONDITIONS TO DETERIORATE TO MVFR WITH
TEMPO IFR VSBY IN ANY MODERATE BURSTS OF SNOW. ACCUMULATIONS ARE
EXPECTED TO BE FAIRLY MINIMAL...A DUSTING TO AROUND HALF AN INCH OR
SO. PRECIPITATION SHOULD BEGIN TO TAPER LATE THIS AFTERNOON OR EARLY
THIS EVENING AS UPPER LEVEL RIDGING BEGINS TO BUILD OVERHEAD
SUPPRESSING THE DEEPER MOISTURE. ON THE OTHER HAND...PERSISTENT LOW
LEVEL CONVERGENCE NEAR THE SURFACE TROUGH MAY RESULT IN WEAK ASCENT
LATER INTO THE EVENING WHICH WOULD SUPPORT A FEW FLURRIES...OR
POSSIBLY DRIZZLE AT TIMES AS SOUNDINGS INDICATE LOSS OF ICE IN THE
COLUMN LATER THIS EVENING AS DRY AIR BUILDS DOWN IN THE UPPER LEVEL
SUBSIDENCE. SOUTH WINDS THIS AFTERNOON SHOULD BACK AROUND TO THE
NORTHEAST OVERNIGHT.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE IN VSBY/CIG TRENDS WITH PRECIP.
* MEDIUM-HIGH CONFIDENCE IN PREVAILING MVFR CIGS DEVELOPING THIS
AFTERNOON.
* LOW CONFIDENCE IN END TIME OF PRECIP TONIGHT. LOW-MEDIUM
CONFIDENCE THAT SNOW MAY CHANGE OR MIX WITH DRIZZLE AT SOME
POINT LATE THIS EVENING.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...MAINLY VFR.
WEDNESDAY...MAINLY VFR DURING THE DAY. CHANCE OF RAIN/SNOW AT
NIGHT WITH MVFR/IFR POSSIBLE.
THURSDAY...CHANCE OF LIGHT SNOW. MVFR LIKELY/IFR POSSIBLE.
FRIDAY...MAINLY VFR.
SATURDAY...CHANCE OF SNOW/MVFR CIGS.
SUNDAY...MVFR CIGS POSSIBLE.
RATZER
&&
.MARINE...
143 AM CST
ONLY MARINE FORECAST CONCERNS ARE A BRIEF PERIOD OF ENHANCED
SOUTH-SOUTHEAST WINDS THIS AFTERNOON AND EVENING ESPECIALLY ON THE
NORTHERN PORTION OF THE LAKE...AND AGAIN WEDNESDAY AFTERNOON. GUSTY
NORTH WINDS NEAR 30 KT ARE ALSO LIKELY THURSDAY AND THURSDAY
NIGHT.
WINDS CONTINUE TO DIMINISH QUICKLY ACROSS LAKE MICHIGAN EARLY THIS
MORNING...AS WEAK HIGH PRESSURE RIDING SLIDES SOUTHEAST ACROSS THE
LAKE. THIS RIDGE WILL ALSO PASS QUICKLY OFF TO THE SOUTHEAST THIS
AFTERNOON IN WHAT REMAINS A PROGRESSIVE WEATHER PATTERN...WITH
ANOTHER LOW PRESSURE SYSTEM CURRENTLY NEAR LAKE WINNIPEG MOVING
QUICKLY SOUTHEAST INTO ILLINOIS BY MIDNIGHT TONIGHT WHILE FILLING.
THIS WILL RESULT IN WINDS BECOMING SOUTH AND INCREASING TO AROUND 20
KTS ON THE LAKE THIS AFTERNOON...THEN DECREASING AND BACKING TO THE
NORTHEAST INTO TUESDAY MORNING AS THE LOW PASSES AND WEAKENS.
ANOTHER HIGH PRESSURE RIDGE WILL SETTLE ACROSS THE WESTERN LAKES BY
TUESDAY EVENING.
ANOTHER MORE DEVELOPED LOW WILL FORM ACROSS THE LAKES TUESDAY
NIGHT...AND WILL DEEPEN SLIGHTLY AS IT APPROACHES FROM THE WEST
WEDNESDAY AND PASSES JUST SOUTH OF LAKE MICHIGAN EARLY THURSDAY
MORNING. THIS WILL AGAIN RESULT IN WINDS INITIALLY BECOMING SOUTH
AND INCREASING TO 20-25 KT WEDNESDAY AFTERNOON AND EVENING...THEN
BACKING TO THE NORTH EARLY THURSDAY AND GUSTING NEAR 30 KT AS THE
LOW PULLS AWAY ACROSS THE EASTERN LAKES AND UPPER OHIO VALLEY
THROUGH THURSDAY AFTERNOON AND NIGHT. HIGH PRESSURE THEN SPREADS
ACROSS THE REGION BY FRIDAY AFTERNOON.
FOR THE ILLINOIS AND NORTHWEST INDIANA NEARSHORE WATERS...AS SMALL
CRAFT ADVISORY REMAINS IN EFFECT UNTIL MID-MORNING TODAY...AS WAVES
CONTINUE TO SUBSIDE FROM YESTERDAY/LAST EVENINGS STRONG NORTHEAST
WINDS.
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
NATIONAL WEATHER SERVICE LINCOLN IL
1255 PM CST Mon Jan 26 2015
.UPDATE...
ISSUED AT 1036 AM CST MON JAN 26 2015
Brief wave moving through the region bringing some snowfall for
Central Illinois today. Temporary visibility drops associated with
the heavier snowfall. Other than some timely adjustments of pops
and weather for a more expedient system, forecast actually looking
good. Very minor adjustments, but no major updates anticipated at
this time.
&&
.SHORT TERM...(Today)
ISSUED AT 443 AM CST MON JAN 26 2015
Latest surface analysis indicating weak high pressure centered from
central lower Michigan southwest through northeast Missouri. Our
next weather system was already producing some light snow across
parts of central Minnesota...which was tracking southeast early this
morning. The main short term forecast concern will be with this weak
upper level system that will track across our area today and the
precip chances with it.
Models have trended a bit further south and west with the upper wave
along with the fairly compact area of lift associated with it.
Forcing in the 700-500 mb layer compact but short lived with this
system and based on the latest HRRR and RAP solutions, it appears
the threat (20-30 POPs) for light snow will track southeast into our
area later this morning and then shift into east central Illinois by
this afternoon and evening. Forecast soundings have all trended a
bit deeper with the moisture with this system and cold enough to
support light snow except over far southwest Illinois where there
may be a mix of rain and snow for a few hours as surface temps rise
into the middle 30s.
Despite the decent low to mid level forcing with this wave, QPF
amounts will be light with any snow accumulations of less than an
inch. As the better forcing shifts off to our east, we start to lose
the ice crystals in the upper levels of the clouds that would support
mainly light snow. Nam time-height cross sections showing some very
weak lift tracking thru the area late this afternoon in the 925-850
mb layer so not the greatest setup for freezing drizzle but will
need to be watched later this afternoon and evening.
&&
.LONG TERM...(Tonight through Sunday)
ISSUED AT 443 AM CST MON JAN 26 2015
Elongated short wave will gradually shift east of IL by dawn Tue
with light snow chances shifting east of IL into Indiana. Low clouds
will be slow to clear from the west Tue with mostly cloudy skies
generally prevailing with IL river valley having better chance of
becoming partly sunny during Tue afternoon. Seasonable highs in the
mid to upper 30s Tue with north winds 8-15 mph. Low clouds to
continue to decrease Tue night as weak surface high pressure ridge
sets up over IL by Tue evening. Lows Tue night in the low to mid
20s.
Upper level ridging into IL Wed will give partly to mostly sunny
skies, while 1005 mb surface low pressure moving east into the
central plains Wed to give breezy sse winds of milder air into the
region with highs in the 40s Wed (ranging from lower 40s ne counties
to near 50F from Jacksonville sw. Low pressure to move east across
central IL during Wed night and bring a chance of light rain with
lows staying above freezing in the mid to upper 30s. Light rain
chances to diminish from west to east during Thu and could see light
snow chances too over northern counties before ending as cooler air
arrives on back side of low pressure moving into the southern Great
Lakes region. Highs Thu range from upper 30s to near 40F IL river
valley to upper 40s in southeast IL.
Dry conditions and cooler temps return to central/se IL from Thu
night thru Fri night as high pressure settles into the ohio river
valley by Friday evening. Highs Fri back to seasonable levels for
late Jan in the mid to upper 30s. Continued slight chances of light
snow Sat and Sat night as cold front moves through. A cutoff upper
level low in the sw states late this week will move east and keeps
brunt of its qpf south of central IL, though some models have us on
northern edge of lighter qpf this weekend. Also have a northern
stream clipper system moving through the Great Lakes Sat and Sat
night that drives a cold front through IL. May need to increase
chances of light snow this weekend, though timing issues and also
question if any phasing can take place better stronger southern
stream system and weaken northern stream short wave. Also southern
areas could see a mix of precipitation on Sat before colder air
arrives Sat night. MEX/GFS appears too warm with temps behind cold
front Sun/Mon and oddly doesn`t cool it off much from Sat. ECMWF/ECE
model cools off much more Sun/Mon. Did not go as cold as this model,
but have temps dropping from highs in upper 30s/near 40F Sat to
upper 20s/lower 30s Sunday.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 1247 PM CST MON JAN 26 2015
Wave moving through Central Illinois and bringing quick drops in
category to IFR and isolated LIFR with some of the heavier snow bands.
Heavier showers not always discernible on radar making the TAF
trends difficult. PIA and SPI soon to the on the back edge of the
heavier snows...with cigs around 2kft...but a few obs with holes
to VFR. TAF forecast to the more degraded conditions as moisture
saturates through the column and drops categories more widespread
through the afternoon and into the overnight hours. Winds becoming
more NWrly. Models keeping low cigs through the overnight with
some MVFR reductions in vis predominant...with possible patchy drops
to IFR.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HJS
SHORT TERM...Smith
LONG TERM...07
AVIATION...HJS
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1155 AM CST MON JAN 26 2015
.SHORT TERM...
315 AM CST
THROUGH TONIGHT...
AN IMPRESSIVE WATER VAPOR LOOP THIS MORNING AS ROARING SUBTROPICAL
JET ACROSS THE SOUTHEAST IS DEEPENING A SIGNIFICANT SYSTEM THAT WILL
IMPACT THE NORTHEAST U.S. OVER THE NEXT 24 TO 36 HOURS. THE NORTHERN
STREAM JET WHICH IS ALSO HELPING TO CARVE OUT THE DEVELOPING TROUGH
IS DIVING SOUTHWARD OVER OUR REGION TODAY. ON THE CYCLONIC SIDE OF
THIS...FROM MANITOBA TO THE LOWER OHIO VALLEY...AN ELONGATED AREA OF
VORTICITY GENERATION WILL SUPPORT FORCING FOR ASCENT TODAY AND
TONIGHT...WITH THE MOST FOCUSED ZONE BEING A BETTER DEFINED WAVE
SEEN OVER CENTRAL MN EARLY THIS MORNING. THE RUN-TO-RUN TREND ON THE
RAP MODEL EARLY THIS MORNING IS FURTHER
WEST/SOUTHWEST...SUPPORTING UPSTREAM RADAR TRENDS AND FAVORING
NORTH CENTRAL IL TO GET IN A PERIOD OF SNOW BEGINNING LATER THIS
MORNING FOLLOWED BY A GRADUAL EXPANSION EAST. WHILE MOST OF THE
SNOW WILL BE LIGHT...THERE IS A WINDOW OF TIME LATE THIS MORNING
AND EARLY THIS AFTERNOON OVER NORTH CENTRAL ILLINOIS WHERE
850-700MB CONVERGENCE AND A F-GEN INDUCED CIRCULATION MAY ALLOW
FOR SPOTTY BURSTS OF MODERATE SNOW...WHICH HIGH-RESOLUTION
GUIDANCE TRIES TO INDICATE TOO. WITH ADJACENT OFFICES AND WPC
COLLABORATION...HAVE AROUND AN INCH FORECAST IN THE ROCKFORD
AREA...WITH AROUND A HALF INCH FURTHER EAST OF THERE. SOUTHWARD IN
THE FORECAST AREA THE DRY AIR SEEMS MORE PRONOUNCED...SO MAY END
UP JUST BEING FLURRIES AT TIMES.
THE FORCING ALOFT WEAKENS LATER THIS AFTERNOON AND EVENING SO
EXPECTING LIGHT SNOW TO BECOME MORE PATCHY IN COVERAGE. THE MOISTURE
IN THE ICE LAYER GRADUALLY DIMINISHES FROM WEST TO EAST THROUGH THE
EVENING...WITH STILL SOME LIGHT ADIABATIC ASCENT IN THE LOWEST
COUPLE THOUSAND FEET. IF THAT LOWEST LAYER IS SATURATED OR ABLE TO
THERE COULD BE A FREEZING DRIZZLE CONCERN...SO MAINTAIN THE GOING
CHANCE IN THE FORECAST.
FOR TEMPERATURES TODAY...DID BUMP DOWN SEVERAL DEGREES AS CLEARING
LAST NIGHT ALLOWED PLACES TO DROP QUICKLY AND NOW THE CLOUD CANOPY
WILL HINDER THEM FROM WARMING MUCH. FORECAST HIGHS ARE MAINLY IN THE
MID 20S WITH A FEW UPPER 20S POSSIBLE. WHILE THAT DOES NOT MAKE
HEADLINES IN JANUARY...IF THE FORECAST PANS OUT THIS WOULD BE THE
FIRST DAY WITH HIGHS BELOW 30 SINCE JANUARY 14TH.
MTF
&&
.LONG TERM...
315 AM CST
TUESDAY THROUGH SUNDAY...
HIGH PRESSURE WILL MOVE OVER THE AREA TUESDAY AFTERNOON AND NIGHT
BEFORE RETURN FLOW ON WEDNESDAY. THE CHALLENGE OF CLOUD COVER
PRESENTS ITSELF AGAIN ON TUESDAY AND WHILE HAVE SLOWED THE
CLEARING TREND TUESDAY MORNING...STILL THINK THE AFTERNOON SHOULD
SEE SOME BREAKS OF SUN AREAWIDE. SOUTHERLY FLOW ON WEDNESDAY IS
FORECAST TO BRING 925MB TEMPERATURES TO AROUND 0C WHICH USING
CLIMATOLOGY WITH LIMITED SNOW COVER SHOULD SUPPORT WIDESPREAD MID
TO UPPER 30S WITH A FEW LOWER 40S POSSIBLE IN THE SOUTHWEST CWA
OR CHICAGO METRO.
THE LARGE CLOSED LOW OFF THE BAJA OF CALIFORNIA THIS MORNING IS
FORECAST BY THE SUITE OF GUIDANCE TO DRIFT NORTHWARD AND GET CAUGHT
UP IN THE WESTERLIES BECOMING AN OPEN WAVE ACROSS THE MIDDLE OF THE
COUNTRY. WITH THE MASSIVE SYSTEM OFF THE NORTHEAST LIKELY TO SLOW
THINGS A BIT...CONTINUE TO LEAN WITH THE SLOWER EC AND GEM MODELS
WHICH WOULD FAVOR PRECIPITATION CHANCES MORE SO LATE WEDNESDAY NIGHT
AND THURSDAY...AROUND 12H SLOWER THAN THE GFS. FORECAST VERTICAL
PROFILES ON BOTH MODELS WOULD SUPPORT MORE OF RAIN AHEAD OF THIS
SYSTEM...ESPECIALLY CONSIDERING LOW-LEVEL TEMPERATURES SHOULD AT THE
VERY LEAST HOLD STEADY IF NOT MODERATE WEDNESDAY NIGHT...POTENTIALLY
TO 35 TO 38 DEGREES GIVEN EC AND GEM SOLUTIONS. ON THE BACKSIDE OF
THIS SYSTEM IT WOULD SEEM THERE WOULD BE AT LEAST A PERIOD OF SNOW
CHANCES. OBVIOUSLY A FEW DAYS OUT AND A CUTOFF LOW INVOLVED...A
LOT COULD CHANGE WITH SPECIFICS...BUT RIGHT NOW THIS IS NOT
LOOKING LIKE A HIGH IMPACT EVENT.
LATE THIS WEEK INTO THE WEEKEND THE NORTHERN STREAM FLOW PATTERN
IS FORECAST TO REMAIN QUITE PROGRESSIVE WHILE ANOTHER CUTOFF LOW
IS PROGGED TO DEVELOP OVER THE FAR SOUTHWEST US. THE 00Z EC HAS
FORECAST A STRONG SYSTEM IN THE NORTHWEST FLOW TO WIN OUT ABOUT A
WEEK FROM NOW AND DRAG DOWN -15C TO -20C 850MB TEMPERATURES.
SOMETHING TO MONITOR AS WE HEAD TOWARD THE FIRST DAYS OF FEBRUARY.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SNOW THIS AFTERNOON WITH MVFR CONDITIONS AND TEMPO IFR...AND
LIGHT ACCUMULATIONS LESS THAN AN INCH.
* SNOW TAPERING THIS EVENING AND POSSIBLY TRANSITIONING TO OR
MIXING WITH DRIZZLE.
BMD
//DISCUSSION...UPDATED 18Z...
SHEARED UPPER LEVEL DISTURBANCE IS HELPING TO DRIVE AN AREA OF SNOW
ACROSS ILLINOIS AND WISCONSIN EARLY THIS AFTERNOON. THIS SNOW IS
EXPECTED TO MOVE INTO THE CHICAGO AREA OVER THE NEXT COUPLE HOURS.
INITIALLY DRY LOW/MID LEVELS WILL TAKE THEIR TIME TO SATURATE AS THE
RADAR RETURNS MOVE OVERHEAD...PRECIPITATION INITIALLY EVAPORATING IN
THE DRY AIR...BUT THEN EXPECT CONDITIONS TO DETERIORATE TO MVFR WITH
TEMPO IFR VSBY IN ANY MODERATE BURSTS OF SNOW. ACCUMULATIONS ARE
EXPECTED TO BE FAIRLY MINIMAL...A DUSTING TO AROUND HALF AN INCH OR
SO. PRECIPITATION SHOULD BEGIN TO TAPER LATE THIS AFTERNOON OR EARLY
THIS EVENING AS UPPER LEVEL RIDGING BEGINS TO BUILD OVERHEAD
SUPPRESSING THE DEEPER MOISTURE. ON THE OTHER HAND...PERSISTENT LOW
LEVEL CONVERGENCE NEAR THE SURFACE TROUGH MAY RESULT IN WEAK ASCENT
LATER INTO THE EVENING WHICH WOULD SUPPORT A FEW FLURRIES...OR
POSSIBLY DRIZZLE AT TIMES AS SOUNDINGS INDICATE LOSS OF ICE IN THE
COLUMN LATER THIS EVENING AS DRY AIR BUILDS DOWN IN THE UPPER LEVEL
SUBSIDENCE. SOUTH WINDS THIS AFTERNOON SHOULD BACK AROUND TO THE
NORTHEAST OVERNIGHT.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN SNOW/TIMING BUT LOW-MEDIUM CONFIDENCE IN
VSBY/CIG TRENDS WITH PRECIP.
* MEDIUM-HIGH CONFIDENCE IN PREVAILING MVFR CIGS DEVELOPING THIS
AFTERNOON.
* LOW CONFIDENCE IN END TIME OF PRECIP TONIGHT. LOW-MEDIUM
CONFIDENCE THAT SNOW MAY CHANGE OR MIX WITH DRIZZLE AT SOME
POINT LATE THIS EVENING.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...MAINLY VFR.
WEDNESDAY...MAINLY VFR DURING THE DAY. CHANCE OF RAIN/SNOW AT
NIGHT WITH MVFR/IFR POSSIBLE.
THURSDAY...CHANCE OF LIGHT SNOW. MVFR LIKELY/IFR POSSIBLE.
FRIDAY...MAINLY VFR.
SATURDAY...CHANCE OF SNOW/MVFR CIGS.
SUNDAY...MVFR CIGS POSSIBLE.
RATZER
&&
.MARINE...
143 AM CST
ONLY MARINE FORECAST CONCERNS ARE A BRIEF PERIOD OF ENHANCED
SOUTH-SOUTHEAST WINDS THIS AFTERNOON AND EVENING ESPECIALLY ON THE
NORTHERN PORTION OF THE LAKE...AND AGAIN WEDNESDAY AFTERNOON. GUSTY
NORTH WINDS NEAR 30 KT ARE ALSO LIKELY THURSDAY AND THURSDAY
NIGHT.
WINDS CONTINUE TO DIMINISH QUICKLY ACROSS LAKE MICHIGAN EARLY THIS
MORNING...AS WEAK HIGH PRESSURE RIDING SLIDES SOUTHEAST ACROSS THE
LAKE. THIS RIDGE WILL ALSO PASS QUICKLY OFF TO THE SOUTHEAST THIS
AFTERNOON IN WHAT REMAINS A PROGRESSIVE WEATHER PATTERN...WITH
ANOTHER LOW PRESSURE SYSTEM CURRENTLY NEAR LAKE WINNIPEG MOVING
QUICKLY SOUTHEAST INTO ILLINOIS BY MIDNIGHT TONIGHT WHILE FILLING.
THIS WILL RESULT IN WINDS BECOMING SOUTH AND INCREASING TO AROUND 20
KTS ON THE LAKE THIS AFTERNOON...THEN DECREASING AND BACKING TO THE
NORTHEAST INTO TUESDAY MORNING AS THE LOW PASSES AND WEAKENS.
ANOTHER HIGH PRESSURE RIDGE WILL SETTLE ACROSS THE WESTERN LAKES BY
TUESDAY EVENING.
ANOTHER MORE DEVELOPED LOW WILL FORM ACROSS THE LAKES TUESDAY
NIGHT...AND WILL DEEPEN SLIGHTLY AS IT APPROACHES FROM THE WEST
WEDNESDAY AND PASSES JUST SOUTH OF LAKE MICHIGAN EARLY THURSDAY
MORNING. THIS WILL AGAIN RESULT IN WINDS INITIALLY BECOMING SOUTH
AND INCREASING TO 20-25 KT WEDNESDAY AFTERNOON AND EVENING...THEN
BACKING TO THE NORTH EARLY THURSDAY AND GUSTING NEAR 30 KT AS THE
LOW PULLS AWAY ACROSS THE EASTERN LAKES AND UPPER OHIO VALLEY
THROUGH THURSDAY AFTERNOON AND NIGHT. HIGH PRESSURE THEN SPREADS
ACROSS THE REGION BY FRIDAY AFTERNOON.
FOR THE ILLINOIS AND NORTHWEST INDIANA NEARSHORE WATERS...AS SMALL
CRAFT ADVISORY REMAINS IN EFFECT UNTIL MID-MORNING TODAY...AS WAVES
CONTINUE TO SUBSIDE FROM YESTERDAY/LAST EVENINGS STRONG NORTHEAST
WINDS.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1041 AM CST Mon Jan 26 2015
.UPDATE...
ISSUED AT 1036 AM CST MON JAN 26 2015
Brief wave moving through the region bringing some snowfall for
Central Illinois today. Temporary visibility drops associated with
the heavier snowfall. Other than some timely adjustments of pops
and weather for a more expedient system, forecast actually looking
good. Very minor adjustments, but no major updates anticipated at
this time.
&&
.SHORT TERM...(Today)
ISSUED AT 443 AM CST MON JAN 26 2015
Latest surface analysis indicating weak high pressure centered from
central lower Michigan southwest through northeast Missouri. Our
next weather system was already producing some light snow across
parts of central Minnesota...which was tracking southeast early this
morning. The main short term forecast concern will be with this weak
upper level system that will track across our area today and the
precip chances with it.
Models have trended a bit further south and west with the upper wave
along with the fairly compact area of lift associated with it.
Forcing in the 700-500 mb layer compact but short lived with this
system and based on the latest HRRR and RAP solutions, it appears
the threat (20-30 POPs) for light snow will track southeast into our
area later this morning and then shift into east central Illinois by
this afternoon and evening. Forecast soundings have all trended a
bit deeper with the moisture with this system and cold enough to
support light snow except over far southwest Illinois where there
may be a mix of rain and snow for a few hours as surface temps rise
into the middle 30s.
Despite the decent low to mid level forcing with this wave, QPF
amounts will be light with any snow accumulations of less than an
inch. As the better forcing shifts off to our east, we start to lose
the ice crystals in the upper levels of the clouds that would support
mainly light snow. Nam time-height cross sections showing some very
weak lift tracking thru the area late this afternoon in the 925-850
mb layer so not the greatest setup for freezing drizzle but will
need to be watched later this afternoon and evening.
&&
.LONG TERM...(Tonight through Sunday)
ISSUED AT 443 AM CST MON JAN 26 2015
Elongated short wave will gradually shift east of IL by dawn Tue
with light snow chances shifting east of IL into Indiana. Low clouds
will be slow to clear from the west Tue with mostly cloudy skies
generally prevailing with IL river valley having better chance of
becoming partly sunny during Tue afternoon. Seasonable highs in the
mid to upper 30s Tue with north winds 8-15 mph. Low clouds to
continue to decrease Tue night as weak surface high pressure ridge
sets up over IL by Tue evening. Lows Tue night in the low to mid
20s.
Upper level ridging into IL Wed will give partly to mostly sunny
skies, while 1005 mb surface low pressure moving east into the
central plains Wed to give breezy sse winds of milder air into the
region with highs in the 40s Wed (ranging from lower 40s ne counties
to near 50F from Jacksonville sw. Low pressure to move east across
central IL during Wed night and bring a chance of light rain with
lows staying above freezing in the mid to upper 30s. Light rain
chances to diminish from west to east during Thu and could see light
snow chances too over northern counties before ending as cooler air
arrives on back side of low pressure moving into the southern Great
Lakes region. Highs Thu range from upper 30s to near 40F IL river
valley to upper 40s in southeast IL.
Dry conditions and cooler temps return to central/se IL from Thu
night thru Fri night as high pressure settles into the ohio river
valley by Friday evening. Highs Fri back to seasonable levels for
late Jan in the mid to upper 30s. Continued slight chances of light
snow Sat and Sat night as cold front moves through. A cutoff upper
level low in the sw states late this week will move east and keeps
brunt of its qpf south of central IL, though some models have us on
northern edge of lighter qpf this weekend. Also have a northern
stream clipper system moving through the Great Lakes Sat and Sat
night that drives a cold front through IL. May need to increase
chances of light snow this weekend, though timing issues and also
question if any phasing can take place better stronger southern
stream system and weaken northern stream short wave. Also southern
areas could see a mix of precipitation on Sat before colder air
arrives Sat night. MEX/GFS appears too warm with temps behind cold
front Sun/Mon and oddly doesn`t cool it off much from Sat. ECMWF/ECE
model cools off much more Sun/Mon. Did not go as cold as this model,
but have temps dropping from highs in upper 30s/near 40F Sat to
upper 20s/lower 30s Sunday.
&&
.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
ISSUED AT 500 AM CST MON JAN 26 2015
Next weather system quickly tracking southeast out of Minnesota
this morning and will begin to affect our area after 15z this
morning with lower cigs and a period of -SN that may restrict
vsbys for a brief time as well. After that, forecast soundings
indicate as the system that brings the scattered light snow
to the area today moves away, we will lose the ice crystals
needed to support light snow with the threat for some freezing
drizzle late this afternoon and especially this evening. Not
very confident on the freezing drizzle at this point so will
not include in the 12z forecast but something to watch for
in later forecasts.
MVFR cigs still linger at DEC and CMI but based on latest
satellite data, they were very close to the backedge of the clouds
and will probably scatter the lower cigs out with VFR cigs
thereafter until early afternoon when all areas will see cigs
lower to MVFR with local IFR cigs in the areas of light snow. For
now, will include a tempo group for light snow only at PIA and BMI
this afternoon with VCSH for the remainder of the TAF sites. Look
for MVFR and occasional IFR cigs to prevail into the evening
hours.
Surface winds will be out of the south at around 10 kts today
with a wind shift into the northwest later this evening with
speeds tonight at 5 to 10 kts.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HJS
SHORT TERM...Smith
LONG TERM...07
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
549 AM CST MON JAN 26 2015
.SHORT TERM...
315 AM CST
THROUGH TONIGHT...
AN IMPRESSIVE WATER VAPOR LOOP THIS MORNING AS ROARING SUBTROPICAL
JET ACROSS THE SOUTHEAST IS DEEPENING A SIGNIFICANT SYSTEM THAT WILL
IMPACT THE NORTHEAST U.S. OVER THE NEXT 24 TO 36 HOURS. THE NORTHERN
STREAM JET WHICH IS ALSO HELPING TO CARVE OUT THE DEVELOPING TROUGH
IS DIVING SOUTHWARD OVER OUR REGION TODAY. ON THE CYCLONIC SIDE OF
THIS...FROM MANITOBA TO THE LOWER OHIO VALLEY...AN ELONGATED AREA OF
VORTICITY GENERATION WILL SUPPORT FORCING FOR ASCENT TODAY AND
TONIGHT...WITH THE MOST FOCUSED ZONE BEING A BETTER DEFINED WAVE
SEEN OVER CENTRAL MN EARLY THIS MORNING. THE RUN-TO-RUN TREND ON THE
RAP MODEL EARLY THIS MORNING IS FURTHER
WEST/SOUTHWEST...SUPPORTING UPSTREAM RADAR TRENDS AND FAVORING
NORTH CENTRAL IL TO GET IN A PERIOD OF SNOW BEGINNING LATER THIS
MORNING FOLLOWED BY A GRADUAL EXPANSION EAST. WHILE MOST OF THE
SNOW WILL BE LIGHT...THERE IS A WINDOW OF TIME LATE THIS MORNING
AND EARLY THIS AFTERNOON OVER NORTH CENTRAL ILLINOIS WHERE
850-700MB CONVERGENCE AND A F-GEN INDUCED CIRCULATION MAY ALLOW
FOR SPOTTY BURSTS OF MODERATE SNOW...WHICH HIGH-RESOLUTION
GUIDANCE TRIES TO INDICATE TOO. WITH ADJACENT OFFICES AND WPC
COLLABORATION...HAVE AROUND AN INCH FORECAST IN THE ROCKFORD
AREA...WITH AROUND A HALF INCH FURTHER EAST OF THERE. SOUTHWARD IN
THE FORECAST AREA THE DRY AIR SEEMS MORE PRONOUNCED...SO MAY END
UP JUST BEING FLURRIES AT TIMES.
THE FORCING ALOFT WEAKENS LATER THIS AFTERNOON AND EVENING SO
EXPECTING LIGHT SNOW TO BECOME MORE PATCHY IN COVERAGE. THE MOISTURE
IN THE ICE LAYER GRADUALLY DIMINISHES FROM WEST TO EAST THROUGH THE
EVENING...WITH STILL SOME LIGHT ADIABATIC ASCENT IN THE LOWEST
COUPLE THOUSAND FEET. IF THAT LOWEST LAYER IS SATURATED OR ABLE TO
THERE COULD BE A FREEZING DRIZZLE CONCERN...SO MAINTAIN THE GOING
CHANCE IN THE FORECAST.
FOR TEMPERATURES TODAY...DID BUMP DOWN SEVERAL DEGREES AS CLEARING
LAST NIGHT ALLOWED PLACES TO DROP QUICKLY AND NOW THE CLOUD CANOPY
WILL HINDER THEM FROM WARMING MUCH. FORECAST HIGHS ARE MAINLY IN THE
MID 20S WITH A FEW UPPER 20S POSSIBLE. WHILE THAT DOES NOT MAKE
HEADLINES IN JANUARY...IF THE FORECAST PANS OUT THIS WOULD BE THE
FIRST DAY WITH HIGHS BELOW 30 SINCE JANUARY 14TH.
MTF
&&
.LONG TERM...
315 AM CST
TUESDAY THROUGH SUNDAY...
HIGH PRESSURE WILL MOVE OVER THE AREA TUESDAY AFTERNOON AND NIGHT
BEFORE RETURN FLOW ON WEDNESDAY. THE CHALLENGE OF CLOUD COVER
PRESENTS ITSELF AGAIN ON TUESDAY AND WHILE HAVE SLOWED THE
CLEARING TREND TUESDAY MORNING...STILL THINK THE AFTERNOON SHOULD
SEE SOME BREAKS OF SUN AREAWIDE. SOUTHERLY FLOW ON WEDNESDAY IS
FORECAST TO BRING 925MB TEMPERATURES TO AROUND 0C WHICH USING
CLIMATOLOGY WITH LIMITED SNOW COVER SHOULD SUPPORT WIDESPREAD MID
TO UPPER 30S WITH A FEW LOWER 40S POSSIBLE IN THE SOUTHWEST CWA
OR CHICAGO METRO.
THE LARGE CLOSED LOW OFF THE BAJA OF CALIFORNIA THIS MORNING IS
FORECAST BY THE SUITE OF GUIDANCE TO DRIFT NORTHWARD AND GET CAUGHT
UP IN THE WESTERLIES BECOMING AN OPEN WAVE ACROSS THE MIDDLE OF THE
COUNTRY. WITH THE MASSIVE SYSTEM OFF THE NORTHEAST LIKELY TO SLOW
THINGS A BIT...CONTINUE TO LEAN WITH THE SLOWER EC AND GEM MODELS
WHICH WOULD FAVOR PRECIPITATION CHANCES MORE SO LATE WEDNESDAY NIGHT
AND THURSDAY...AROUND 12H SLOWER THAN THE GFS. FORECAST VERTICAL
PROFILES ON BOTH MODELS WOULD SUPPORT MORE OF RAIN AHEAD OF THIS
SYSTEM...ESPECIALLY CONSIDERING LOW-LEVEL TEMPERATURES SHOULD AT THE
VERY LEAST HOLD STEADY IF NOT MODERATE WEDNESDAY NIGHT...POTENTIALLY
TO 35 TO 38 DEGREES GIVEN EC AND GEM SOLUTIONS. ON THE BACKSIDE OF
THIS SYSTEM IT WOULD SEEM THERE WOULD BE AT LEAST A PERIOD OF SNOW
CHANCES. OBVIOUSLY A FEW DAYS OUT AND A CUTOFF LOW INVOLVED...A
LOT COULD CHANGE WITH SPECIFICS...BUT RIGHT NOW THIS IS NOT
LOOKING LIKE A HIGH IMPACT EVENT.
LATE THIS WEEK INTO THE WEEKEND THE NORTHERN STREAM FLOW PATTERN
IS FORECAST TO REMAIN QUITE PROGRESSIVE WHILE ANOTHER CUTOFF LOW
IS PROGGED TO DEVELOP OVER THE FAR SOUTHWEST US. THE 00Z EC HAS
FORECAST A STRONG SYSTEM IN THE NORTHWEST FLOW TO WIN OUT ABOUT A
WEEK FROM NOW AND DRAG DOWN -15C TO -20C 850MB TEMPERATURES.
SOMETHING TO MONITOR AS WE HEAD TOWARD THE FIRST DAYS OF FEBRUARY.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* LIGHT SNOW DEVELOPING AROUND MID-DAY. MVFR CIGS/IFR VSBY
POSSIBLE THIS AFTERNOON. MINOR ACCUMULATIONS.
* IFR CIGS AND MVFR FOG POSSIBLE TONIGHT WITH LINGERING FLURRIES.
* LIGHT/VARIABLE WINDS BECOME LIGHT SOUTH TODAY AND SOUTHEAST THIS
EVENING. GENERALLY LESS THAN 10 KT. WINDS THEN BECOME LIGHT
EAST-NORTHEAST LATE TONIGHT.
RATZER
//DISCUSSION...UPDATED 12Z...
WEAK SURFACE HIGH PRESSURE OVER THE AREA WILL MOVE QUICKLY OFF TO
THE SOUTHEAST THIS MORNING...AS AN AREA OF LOW PRESSURE RAPIDLY
APPROACHES FROM THE UPPER MIDWEST. VFR CLOUDS EXPECTED TO LOWER
THROUGH THE MORNING...WITH DEVELOPMENT OF LIGHT SNOW AND MVFR CIGS
BY/AROUND MID-DAY. A PERIOD OF LIGHT ACCUMULATING SNOW IS LIKELY
THROUGH THE AFTERNOON...WITH OCCASIONAL IFR VSBYS. SNOW IS
EXPECTED TO TAPER OFF BY EVENING THOUGH WILL LINGER IN LIGHTER
FASHION AND MAY MIX OR CHANGE TO FREEZING DRIZZLE LATE BEFORE
ENDING. MOIST LOW LEVELS AND LIGHT WINDS SUPPORT A PERIOD OF IFR
CIGS AND MVFR VSBYS IN FOG OVERNIGHT AS THE SURFACE LOW FILLS TO
JUST A TROUGH. SNOW ACCUMULATIONS LOOK TO RANGE FROM PERHAPS AN
INCH AROUND RFD...TO LESS THAN AN INCH FARTHER EAST ACROSS CHI
METRO TERMINALS.
WINDS CURRENTLY LIGHT/VARIABLE AS THE SURFACE RIDGE AXIS PASSES
ACROSS THE FORECAST AREA EARLY THIS MORNING. WINDS TO SHIFT SOUTH
DURING THE MORNING...THEN SOUTHEAST BY EVENING. SPEEDS GENERALLY
LESS THAN 10 KTS...THOUGH IF APPROACHING LOW IS SLOWER TO WEAKEN
THAN EXPECTED SOUTHEAST WINDS AROUND 10 KT WOULD BE POSSIBLE LATER
THIS AFTERNOON. WINDS TO TURN LIGHT NORTHEAST LATER TONIGHT INTO
EARLY TUESDAY.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH CONFIDENCE IN WIND TRENDS.
* MEDIUM CONFIDENCE IN SNOW TIMING/INTENSITY TODAY INTO THIS
EVENING.
* MEDIUM-LOW CONFIDENCE IN VIS/CIG TRENDS OVERNIGHT.
RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...MAINLY VFR.
WEDNESDAY...MAINLY VFR DURING THE DAY. CHANCE OF RAIN/SNOW AT
NIGHT WITH MVFR/IFR POSSIBLE.
THURSDAY...CHANCE OF LIGHT SNOW. MVFR LIKELY/IFR POSSIBLE.
FRIDAY...MAINLY VFR.
SATURDAY...CHANCE OF SNOW/MVFR CIGS.
SUNDAY...MVFR CIGS POSSIBLE.
RATZER
&&
.MARINE...
143 AM CST
ONLY MARINE FORECAST CONCERNS ARE A BRIEF PERIOD OF ENHANCED
SOUTH-SOUTHEAST WINDS THIS AFTERNOON AND EVENING ESPECIALLY ON THE
NORTHERN PORTION OF THE LAKE...AND AGAIN WEDNESDAY AFTERNOON. GUSTY
NORTH WINDS NEAR 30 KT ARE ALSO LIKELY THURSDAY AND THURSDAY
NIGHT.
WINDS CONTINUE TO DIMINISH QUICKLY ACROSS LAKE MICHIGAN EARLY THIS
MORNING...AS WEAK HIGH PRESSURE RIDING SLIDES SOUTHEAST ACROSS THE
LAKE. THIS RIDGE WILL ALSO PASS QUICKLY OFF TO THE SOUTHEAST THIS
AFTERNOON IN WHAT REMAINS A PROGRESSIVE WEATHER PATTERN...WITH
ANOTHER LOW PRESSURE SYSTEM CURRENTLY NEAR LAKE WINNIPEG MOVING
QUICKLY SOUTHEAST INTO ILLINOIS BY MIDNIGHT TONIGHT WHILE FILLING.
THIS WILL RESULT IN WINDS BECOMING SOUTH AND INCREASING TO AROUND 20
KTS ON THE LAKE THIS AFTERNOON...THEN DECREASING AND BACKING TO THE
NORTHEAST INTO TUESDAY MORNING AS THE LOW PASSES AND WEAKENS.
ANOTHER HIGH PRESSURE RIDGE WILL SETTLE ACROSS THE WESTERN LAKES BY
TUESDAY EVENING.
ANOTHER MORE DEVELOPED LOW WILL FORM ACROSS THE LAKES TUESDAY
NIGHT...AND WILL DEEPEN SLIGHTLY AS IT APPROACHES FROM THE WEST
WEDNESDAY AND PASSES JUST SOUTH OF LAKE MICHIGAN EARLY THURSDAY
MORNING. THIS WILL AGAIN RESULT IN WINDS INITIALLY BECOMING SOUTH
AND INCREASING TO 20-25 KT WEDNESDAY AFTERNOON AND EVENING...THEN
BACKING TO THE NORTH EARLY THURSDAY AND GUSTING NEAR 30 KT AS THE
LOW PULLS AWAY ACROSS THE EASTERN LAKES AND UPPER OHIO VALLEY
THROUGH THURSDAY AFTERNOON AND NIGHT. HIGH PRESSURE THEN SPREADS
ACROSS THE REGION BY FRIDAY AFTERNOON.
FOR THE ILLINOIS AND NORTHWEST INDIANA NEARSHORE WATERS...AS SMALL
CRAFT ADVISORY REMAINS IN EFFECT UNTIL MID-MORNING TODAY...AS WAVES
CONTINUE TO SUBSIDE FROM YESTERDAY/LAST EVENINGS STRONG NORTHEAST
WINDS.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 9 AM MONDAY.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
507 AM CST Mon Jan 26 2015
.SHORT TERM...(Today)
ISSUED AT 443 AM CST MON JAN 26 2015
Latest surface analysis indicating weak high pressure centered from
central lower Michigan southwest through northeast Missouri. Our
next weather system was already producing some light snow across
parts of central Minnesota...which was tracking southeast early this
morning. The main short term forecast concern will be with this weak
upper level system that will track across our area today and the
precip chances with it.
Models have trended a bit further south and west with the upper wave
along with the fairly compact area of lift associated with it.
Forcing in the 700-500 mb layer compact but short lived with this
system and based on the latest HRRR and RAP solutions, it appears
the threat (20-30 POPs) for light snow will track southeast into our
area later this morning and then shift into east central Illinois by
this afternoon and evening. Forecast soundings have all trended a
bit deeper with the moisture with this system and cold enough to
support light snow except over far southwest Illinois where there
may be a mix of rain and snow for a few hours as surface temps rise
into the middle 30s.
Despite the decent low to mid level forcing with this wave, QPF
amounts will be light with any snow accumulations of less than an
inch. As the better forcing shifts off to our east, we start to lose
the ice crystals in the upper levels of the clouds that would support
mainly light snow. Nam time-height cross sections showing some very
weak lift tracking thru the area late this afternoon in the 925-850
mb layer so not the greatest setup for freezing drizzle but will
need to be watched later this afternoon and evening.
&&
.LONG TERM...(Tonight through Sunday)
ISSUED AT 443 AM CST MON JAN 26 2015
Elongated short wave will gradually shift east of IL by dawn Tue
with light snow chances shifting east of IL into Indiana. Low clouds
will be slow to clear from the west Tue with mostly cloudy skies
generally prevailing with IL river valley having better chance of
becoming partly sunny during Tue afternoon. Seasonable highs in the
mid to upper 30s Tue with north winds 8-15 mph. Low clouds to
continue to decrease Tue night as weak surface high pressure ridge
sets up over IL by Tue evening. Lows Tue night in the low to mid
20s.
Upper level ridging into IL Wed will give partly to mostly sunny
skies, while 1005 mb surface low pressure moving east into the
central plains Wed to give breezy sse winds of milder air into the
region with highs in the 40s Wed (ranging from lower 40s ne counties
to near 50F from Jacksonville sw. Low pressure to move east across
central IL during Wed night and bring a chance of light rain with
lows staying above freezing in the mid to upper 30s. Light rain
chances to diminish from west to east during Thu and could see light
snow chances too over northern counties before ending as cooler air
arrives on back side of low pressure moving into the southern Great
Lakes region. Highs Thu range from upper 30s to near 40F IL river
valley to upper 40s in southeast IL.
Dry conditions and cooler temps return to central/se IL from Thu
night thru Fri night as high pressure settles into the ohio river
valley by Friday evening. Highs Fri back to seasonable levels for
late Jan in the mid to upper 30s. Continued slight chances of light
snow Sat and Sat night as cold front moves through. A cutoff upper
level low in the sw states late this week will move east and keeps
brunt of its qpf south of central IL, though some models have us on
northern edge of ligher qpf this weekend. Also have a northern
stream clipper system moving through the Great Lakes Sat and Sat
night that drives a cold front through IL. May need to increase
chances of light snow this weekend, though timing issues and also
question if any phasing can take place bettern stronger southern
stream system and weakern northern stream short wave. Also southern
areas could see a mix of precipitation on Sat before colder air
arrives Sat night. MEX/GFS appears too warm with temps behind cold
front Sun/Mon and oddly doesn`t cool it off much from Sat. ECWMF/ECE
model cools off much more Sun/Mon. Did not go as cold as this model,
but have temps dropping from highs in upper 30s/near 40F Sat to
upper 20s/lower 30s Sunday.
&&
.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
ISSUED AT 500 AM CST MON JAN 26 2015
Next weather system quickly tracking southeast out of Minnesota
this morning and will begin to affect our area after 15z this
morning with lower cigs and a period of -SN that may restrict
vsbys for a brief time as well. After that, forecast soundings
indicate as the system that brings the scattered light snow
to the area today moves away, we will lose the ice crystals
needed to support light snow with the threat for some freezing
drizzle late this afternoon and especially this evening. Not
very confident on the freezing drizzle at this point so will
not include in the 12z forecast but something to watch for
in later forecasts.
MVFR cigs still linger at DEC and CMI but based on latest
satellite data, they were very close to the backedge of the clouds
and will probably scatter the lower cigs out with VFR cigs
thereafter until early afternoon when all areas will see cigs
lower to MVFR with local IFR cigs in the areas of light snow. For
now, will include a tempo group for light snow only at PIA and BMI
this afternoon with VCSH for the remainder of the TAF sites. Look
for MVFR and occasional IFR cigs to prevail into the evening
hours.
Surface winds will be out of the south at around 10 kts today
with a wind shift into the northwest later this evening with
speeds tonight at 5 to 10 kts.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Smith
LONG TERM...07
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1154 PM CST SUN JAN 25 2015
.UPDATE...
820 PM CST
PCPN IS WINDING DOWN ACROSS THE AREA WITH ONLY SOME LINGERING
LIGHT SNOW SOUTH OF THE KANKAKEE RIVER. WHILE WINDS ARE CURRENTLY
STILL RATHER BREEZY ACROSS THE AREA...THE GENERAL TREND OF THE
REMAINDER OF THE EVENING AND OVERNIGHT SHOULD BE FOR WINDS TO
DIMINISH AND ANY LINGERING SNOW SHOULD PUSH OUT OF THE AREA.
TEMPERATURES SHOULD ALSO DROP OFF WITH PARTIALLY CLEARING SKIES
AND SOME COOLER AIR FILTERING IN AS THE LOW PRESSURE CENTER
ASSOCIATED WITH THE SYSTEM THAT BROUGHT TODAY`S PRECIPITATION
MOVES OFF TO THE SOUTHEAST.
HAVE MADE SOME CHANGES TO THE GOING FORECAST FOR TOMORROW. THE
LATEST 00Z MODEL RUNS ARE TRENDING TOWARD THE NEXT CLIPPER
DROPPING A LITTLE FARTHER SOUTH...WITH SOME MODEST LIFT IN THE
ZONE AHEAD OF A WEAK WARM FRONT ASSOCIATED WITH THE NEXT CLIPPER.
SO HAVE INCREASED POPS...WITH LIKELY POPS FOR THE AFTERNOON HOURS
ACROSS MUCH OF THE AREA...WITH THE EXCEPTION OF THE FAR SOUTHERN
PORTIONS OF THE CWA. ALSO...THE THERMAL PROFILES IN THE LATEST
MODEL SOUNDINGS SUGGEST THAT THE PCPN SHOULD BE ALL SNOW...WITH A
DEEP ENOUGH SATURATED LAYER TO SUPPORT ALL SNOW...AND LESSER
CHANCES FOR FREEZING DRIZZLE. SO...HAVE REMOVED THE FREEZING
DRIZZLE MENTION FOR THE DAYTIME HOURS. STILL FEEL THAT THERE IS A
BETTER CHANCE FOR FREEZING DRIZZLE TOMORROW NIGHT AS DRIER AIR
ALOFT LOWERS THE DEPTH OF THE SATURATED LAYER ENOUGH TO MINIMIZE
THE CHANCE FOR ICE PRODUCTION IN THE SATURATED LAYER. WHILE POPS
HAVE BEEN RAISED...THERE IS LITTLE AVAILABLE DEEP LAYER
MOISTURE...SO ACTUAL SNOWFALL AMOUNTS SHOULD BE LIGHT...ONLY
PERHAPS A COUPLE TENTHS OF AN INCH OF ACCUMULATION.
KREIN
&&
.SHORT TERM...
206 PM CST
TONIGHT THROUGH MONDAY NIGHT...
COOL AIR HAS STRUGGLED TO SLIDE SOUTH THIS AFTERNOON...HOWEVER TEMPS
ARE BEGINNING TO FALL INTO THE UPR 20S ACROSS FAR NORTHEAST IL.
ACROSS THE CENTRAL/SOUTHERN CWFA TEMPS REMAIN IN THE LOW 30S WITH
DEW POINT DEPRESSIONS NOT MUCH MORE THAN 1 TO 2 DEGREES. NORTH OF
I-80 PRECIP IS MAINLY FLURRIES...WITH A RAIN/SNOW MIX SLOWLY
CHANGING TO ALL SNOW LATER THIS AFTERNOON ACROSS THE SOUTHERN CWFA.
THE SHORTWAVE THAT BROUGHT THE LIGHT SNOW CONTINUES TO SLIDE EAST
ACROSS SOUTHERN IL...AND WILL STEADILY BRING AN END TO THE PRECIP
ACROSS THE FORECAST AREA THIS EVENING FROM NORTHWEST TO SOUTHEAST.
WINDS WILL GRADUALLY DIMINISH AS WELL AS THE PRESSURE GRADIENT
RELAXES.
SFC RIDGE CENTERED TO THE NORTH THIS AFTERNOON...WILL SAG SOUTH AND
EXPAND TO COVER A PORTION OF THE WESTERN GREAT LAKES/MISSOURI VALLEY
OVERNIGHT. WHILE SOME EROSION TO THE CLOUDS IS PROBABLE NORTH OF THE
FORECAST AREA...EXPECT SOME DECREASE IN CLOUDS CLOSER TO DAYBREAK
MON. CURRENTLY EXPECT OVERNIGHT LOWS TO DIP INTO THE MID/UPR
TEENS...HOWEVER THIS WILL LIKELY NOT OCCUR UNTIL CLOSER TO DAYBREAK
MON.
THE BRIEF BREAK IN CLOUDS MON MORNING WILL QUICKLY GIVE WAY TO THE
NEXT CLIPPER SYSTEM ARRIVING MON AFTN/EVE. GUIDANCE HAS MAINTAINED A
PROGRESSIVE LOOK TO THIS NEXT WAVE...HOWEVER OPERATIONAL SOLUTIONS
ARE EQUALLY BULLISH ON EROSION OF MOISTURE WITHIN THE LOWEST FEW
LAYERS OF THE ATMOS LATE MON NGT. HAVE SOME CONCERN ABOUT P-TYPE MON
AFTN/EVE. AT THE ONSET MOISTURE WILL QUICKLY SATURATE THRU THE -10
DEG C LAYER AND TOUCH THE FAVORED DGZ...HOWEVER THE DEPTH OF THE
MOISTURE BECOMES MORE SHALLOW MON EVE. ALONG WITH THE LACK OF GOOD
LIFT AND SHALLOW MOISTURE...IT IS LOOKING MORE LIKELY THAT PRECIP
MAY BE A MIX OF FREEZING DRIZZLE/LGT-SNOW.
A WEAK THERMAL RIDGE TRIES TO PUSH OVERHEAD MON AFTN...AS LLVL FLOW
TURNS SOUTHWESTERLY. TEMPS SHUD HOVER ARND FREEZING...HOWEVER THIS
WILL HINGE ON CLOUD COVER ARRIVAL AND DEVELOPMENT OF PRECIP. IF THIS
IS DELAYED...TEMPS COULD PUSH A FEW DEGREES WARMER MON EARLY AFTN.
HEIGHTS SLOWLY INCREASE MON NGT...WITH THE MOISTURE PEELING EAST
ALONG WITH THE WEAKENING SHORTWAVE. AT THIS TIME HAVE MAINTAINED A
MENTION OF LGT SNOW OR PATCHY FREEZING DRIZZLE MON NGT...BUT COULD
END UP WITH A DRY PERIOD.
BEACHLER
&&
.LONG TERM...
206 PM CST
TUESDAY THROUGH SUNDAY...
TOWARDS THE MIDDLE OF THE WEEK ENSEMBLES MAINTAIN A HIGH CONFIDENCE
IN THE TROUGH ALONG THE SOUTHEAST CONUS WEAKENING WITH RIDGING
EXPANDING EAST ACROSS THE CENTRAL PLAINS. THIS SHUD PLACE THE BULK
OF THE REGION INTO A WEAK SFC RIDGE TUE/WED. WED AFTN THE SFC RIDGE
QUICKLY SLIDES SOUTHEAST...WHICH COULD ALLOW SOME WARM AIR TO ADVECT
NORTHEAST INTO THE CWFA AND PUSH SFC TEMPS CLOSE TO 40 DEG.
WITH A QUASI-ZONAL SETUP WED NGT/THUR...GUIDANCE SUGGESTS A ROBUST
MID-LVL VORT WILL QUICKLY SLIDE EAST FROM THE ROCKIES TOWARDS THE
PLAINS WED EVE. GUIDANCE THEN FURTHER STRENGTHENS THIS WAVE AND
LIFTS NORTHEAST ACROSS THE FORECAST AREA THUR. SOUNDINGS SUGGESTS
THAT PRECIP COULD START AS MAINLY RAIN WITH THIS SYSTEM...THEN
DYNAMICALLY COOL OVERNIGHT INTO THUR AND TRANSITION PRECIP OVER TO
LGT SNOW.
A RELATIVELY ACTIVE PATTERN CONTINUES TOWARDS THE END OF THE WEEK
INTO EARLY NEXT WEEKEND...WITH TEMPS GENERALLY IN THE UPR 20S/LOW
30S.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* BRIEF HIGH-END MVFR CIGS OFF LAKE MICHIGAN SHOULD SCATTER BY
SUNRISE.
* PERIOD OF LIGHT SNOW POSSIBLE THIS AFTERNOON/EVENING WITH
REDEVELOPMENT OF MVFR CIGS WHICH LINGER TONIGHT.
RATZER
//DISCUSSION...UPDATED 06Z...
WEAK HIGH PRESSURE RIDGE QUICKLY MOVING INTO FORECAST AREA FROM
THE NORTHWEST OVERNIGHT...THOUGH NORTHEAST WINDS HAVE RESULTED IN
A LAKE-INDUCED PLUME OF MVFR STRATOCU FROM ABOUT ORD EAST...WITH
BASES AROUND 2500 FT. THESE CIGS WILL LIKELY AFFECT ORD/MDW/GYY
UNTIL ABOUT SUNRISE...WHEN MODELS DEPICT NORTHEAST FLOW QUICKLY
BECOMING DISORGANIZED WITH APPROACH OF SFC RIDGE. SFC WINDS TO
BECOME LIGHT/VARIABLE FOR A TIME THIS MORNING AS THE SURFACE HIGH
PRESSURE RIDGE MOVES ACROSS THE TERMINALS...GENERALLY FLOPPING
FROM LIGHT NORTHERLY TO LIGHT SOUTHERLY BY MID-DAY.
IR SATELLITE PICS ALREADY SHOWING HIGH CLOUDS SPILLING INTO THE
REGION FROM THE NORTHWEST AHEAD OF THE NEXT WEAK CLIPPER SYSTEM
WHICH WILL AFFECT THE AREA MONDAY AFTERNOON/EVENING. LOW LEVELS
ARE INITIALLY DRY AND WILL TAKE SOME WORK TO SATURATE FROM ABOVE
AS MID-LEVEL FORCING INCREASES MID-DAY INTO EARLY AFTERNOON. MOST
GUIDANCE DOES INDICATE SOME LIGHT SNOW DEVELOPING DURING THE
PERIOD...THOUGH A COMBINATION OF WEAKENING FORCING AND FORCING
FOCUSED BELOW TEMP LAYER CONDUCIVE TO LARGER SNOWFLAKE GROWTH
SUGGESTS THIS WILL BE RATHER LIGHT. WHILE A FEW INCONSEQUENTIAL
FLURRIES COULD BEGIN SOONER...THE TIMING OF THE PERIOD MOST
LIKELY TO SEE SOME LIGHT SNOW AND MVFR CIG/POSSIBLE IFR VSBY LOOKS
TO BE DURING THE AFTERNOON AT RFD...AND DURING THE LATE AFTN/EARLY
EVENING FOR CHICAGO TERMINALS. SNOW SHOULD TAPER OFF DURING THE
EVENING AT RFD AND BY LATE EVENING FOR CHICAGO TERMINALS...WITH
LOSS OF STRONGER LIFT AND DRYING IN MID-LEVELS. SOME INDICATION
THAT THERE COULD BE A BRIEF PERIOD OF FREEZING DRIZZLE AS THE SNOW
ENDS ESPECIALLY AT RFD WHERE MID-LEVELS DRY A LITTLE MORE
QUICKLY...THOUGH MODELS MAY BE OVERDOING THE DEGREE OF SATURATION
IN THE BOUNDARY LAYER AND CONFIDENCE IS LOW THAT FZDZ WOULD OCCUR.
IT DOES HOWEVER APPEAR THAT SOME SORT OF HIGH-IFR OR LOW-MVFR CIG
MAY LINGER DURING THE NIGHT.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH IN WIND TRENDS.
* MEDIUM-LOW IN SNOW TIMING/INTENSITY THIS AFTERNOON AND EVENING.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...MVFR CIGS POSSIBLE.
WEDNESDAY...VFR DURING THE DAY THEN CHANCE OF -RASN AND MVFR/IFR
AT NIGHT.
THURSDAY...CHANCE OF RAIN/SNOW. MVFR LIKELY/IFR POSSIBLE.
FRIDAY...CHANCE OF MVFR CIGS...ESPECIALLY EARLY.
SATURDAY...CHANCE OF LIGHT SNOW/MVFR CIGS.
IZZI
&&
.MARINE...
131 PM CST
A QUICK MOVING CLIPPER SYSTEM...CURRENTLY CENTERED ACROSS SOUTHERN
ILLINOIS...WILL RAPIDLY SHIFT EASTWARD TOWARDS THE ATLANTIC COAST
BY MONDAY MORNING. NORTHEASTERLY WINDS OF 30-35 KT CONTINUE ACROSS
THE SOUTHERN 1/3RD OF LAKE MICHIGAN...AND THESE WINDS LOOK TO
CONTINUE FOR THE NEXT FEW HOURS...BEFORE A DIMINISHING TREND BEGINS
EARLY THIS EVENING. ANOTHER WEAKENING LOW WILL SHIFT SOUTHWARD JUST
WEST OF THE LAKE LATE MONDAY AND MONDAY NIGHT. THIS WILL RESULT IN A
PERIOD OF SOUTHERLY WINDS OVER THE LAKE DURING THIS PERIOD. LATER IN
THE WEEK ANOTHER LOW IS EXPECTED TO IMPACT THE GREAT LAKES REGION.
THIS SYSTEM STILL HAS THE POTENTIAL TO PRODUCE A PERIOD OF STRONG
SOUTHERLY WINDS LATE WEDNESDAY AND WEDNESDAY NIGHT...FOLLOWED BY A
PERIOD OF STRONG NORTHERLY WINDS THURSDAY INTO EARLY FRIDAY.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 9 AM MONDAY.
&&
$$
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
1121 PM CST Sun Jan 25 2015
.UPDATE...
ISSUED AT 835 PM CST SUN JAN 25 2015
Have tweaked temps/winds/sky for tonight and flurries for
tomorrow. For most part current package is on track.
Precip coming to an end as surface system over central KY
continues to pull away from Illinois. Still could be a snow or
rain shower over the next several hours east of I-57, but for the
most part any significant precip has ended. Weak ridge is building
into Illinois from the northeast scattering out the cloudcover
over western Illinois this evening. This partial clearing will
likely spread only slowly south and east and then be overtaken by
clouds associated with next quick system for Monday. Moisture
remains quite limited with this second cliper and for now will
keep only flurry wording. Forecast soundings from 18z NAM and GFS
suggest that there also could be some freezing drizzle/sprinkles as the
atmospheric column is expected to be quite dry above -8C and it
may be difficult to form ice crystals. Will have to look closer at
this potential once the full 00z model suite has been analyzed.
&&
.SHORT TERM...(Tonight)
ISSUED AT 239 PM CST SUN JAN 25 2015
Area of low pressure which has brought our precipitation was
centered near Carbondale early this afternoon. Rain/snow transition
line has been struggling to move any further south, and in fact
areas from Macomb to Bloomington which had switched over were
starting to mix with rain again. Temperatures have been above
freezing over most of the snow area and accumulations have been
minor and slushy, but some more substantial 1-2 inch totals have
occurred north of Galesburg where temperatures are now below
freezing. The deformation band of snow has been weakening some the
last few hours, and there is a substantial hole in the precip over
the central 2/3 of the forecast area.
The RAP model shows a further weakening of the the deformation band
over the next few hours, and actually has the entire CWA dry by 6
pm. Have some concerns that may be too quick across the southeast,
as the upper wave continues to dig across southeast Missouri, and
have lingered some likely PoP`s down there slightly beyond that time
frame, but reduced PoP`s to below 20% by 9 pm.
Overnight, models are trying to show some substantial clearing over
most of the forecast area beginning late evening. While there is
some breakup of the clouds upstream across Wisconsin, it is not
completely clear up there and the north/northeast flow is not
especially conducive to rapid clearing. Have gone with partly cloudy
skies overnight across the northwest half of the forecast area, but
clouds will already been increasing ahead of the next clipper which
will be dropping southeast into northern Minnesota overnight.
&&
.LONG TERM...(Monday through Sunday)
ISSUED AT 239 PM CST SUN JAN 25 2015
A couple of cooler days are on tap across central and southeast
Illinois in the wake of today`s clipper. There is still a chance we
may see a few snow flakes or sprinkles on Monday as a shearing
upper-level wave, currently diving across the Canadian Prairies,
passes through the Great Lakes region and parts of the Midwest.
However, looking at forecast soundings, there will be a very small
window of opportunity where ice crystals will be present, suggesting
the chance of measurable precipitation is quite low. So, for now,
will only carry a chance of flurries Monday across the northern
portion of the forecast area as the very sheared wave passes to our
north. It is definitely possible that we will see nothing at all, or
perhaps some light drizzle or freezing drizzle (depending on surface
temperatures) due to the paucity of ice crystals.
Temperatures will warm heading into midweek as the persistent
amplified upper-level flow briefly turns more zonal, and a system
approaches from the Pacific coast. This system will mainly pose a
rain threat as it moves through Wednesday night into Thursday. A
brief period of snow is not out of the question later Thursday as
cold air filters in behind the system, but forecast soundings
currently suggest the moisture depth will be too shallow to support
precipitation (no ice crystals) by the time the thermal profile
would support snow.
Another cool down is expected in the wake of the midweek system, but
temperatures should still be near normal for late January. The
eastern North American mean trof that has been in place will try to
reestablish itself by the weekend. A clipper type wave in the
returning northwest upper-level flow may bring a chance of snow to
the area over the weekend. However, the current storm track keeps
the best snow chances to our north, and have only included a slight
chance of snow at this time.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
ISSUED AT 1120 PM CST SUN JAN 25 2015
Clearing area associated with weak ridge building into Illinois
has slowed its southeast progress near I-55. High clouds from
next cliper system already beginning to cross Mississippi River
and will likely overspread sites experiencing clearing over next
few hours.
NAM from 00z suggests that partial clearing will resume its
progress slowly southeast after 06z, but that will be followed by
MVFR deck from next system during the day Monday. Model suite from
00z a bit further south with low measurable pops and impacts all
TAF sites at one time or another. Forecast soundings suggest that
there may still be some potential for FZDZ given the dry air in
crystal formation layer. Will include about a 4-hr tempo group for
I-74 terminals for -SN at this time but later shifts will need to
monitor closely.
Winds are diminishing quickly as the gradient weakens as the
surface ridge moves in. Winds should shift around to the south
Monday and then back to the northwest after the cold front passage
associated with the cliper which will likely be just beyond the
valid time of this set of terminals.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Barker
SHORT TERM...Geelhart
LONG TERM...Bak
AVIATION...Barker
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1147 AM CST MON JAN 26 2015
.UPDATE...
ISSUED AT 558 AM CST MON JAN 26 2015
INTRODUCED PATCHY FZDZ/FLURRIES BETWEEN HIGHWAY 20 TO HIGHWAY 34
AND GENERALLY EAST OF HIGHWAY 169 THROUGH 14Z WITH THE WEAK BAND
OF PRECIP QUICKLY MOVING SOUTH THAT IS JUST MOVING INTO THE FORT
DODGE AREA AS OF 6 AM. ALGONA AND FOREST CITY REPORTING UP...ONLY
CONFIRMING PRECIP IS FINALLY ABLE TO REACH THE SURFACE. SHOULD BE
VERY SHORT-LIVED AND LOOKS TO EXIT THE DSM METRO BY 730-8AM.
.SHORT TERM /TODAY/...
ISSUED AT 318 AM CST MON JAN 26 2015
QUICK MOVING SHORTWAVE LOOKS TO BRING SOME VERY LIGHT SNOW/FZDZ
TO NORTHERN AND EASTERN PORTIONS OF THE FORECAST THIS MORNING.
TIMING OF ANY PRECIP LOOKS TO BE FROM 10Z TO 14Z WITH SOME
LINGERING POPS THROUGH 15Z NEAR THE ALO AREA. LEANED TOWARD A
BLEND OF THE NAM12/RAP FOR POPS TODAY AND TOWARDS THE WARMER
RAP/ECMWF FOR TEMPS.
THE RAP AND NAM MCW/FOD SOUNDINGS HAVE A TOUGH TIME GETTING
COMPLETELY SATURATED AS THEY DEPICT A DEEP DRY LAYER BETWEEN 850-
650MB. CERTAINLY SATURATED BELOW 850MB AND ABOVE 650MB...SO SEEDER
FEEDER POTENTIAL EXISTS BUT FORCING WITHIN THE DENDRITIC LAYER IS
VERY WEAK AND ANY SNOW WILL HAVE A DIFFICULT TIME MAKING IT THROUGH
THIS DRY LAYER. IT MAY SNOW FOR A SHORT STINT BY AROUND 12Z-13Z
ONCE THE COLUMN COMPLETELY SATURATES NEAR MCW/ALO AREA BUT THE
RAP KEEPS THE DRY LAYER THROUGH THE ENTIRE MORNING. AS A
RESULT...WITH THE LACK OF ANY ICE INTRODUCTION...HAVE MENTION OF
FZDZ THIS MORNING. ONLY A MINOR TRAVEL CONCERN WITH THE FZDZ AS
EXPECTING WARMER TEMPERATURES LOOK TO ADVECT IN AND WITH THE VERY
QUICK MOVING SHORTWAVE...THE PRECIP SHOULD BE SHORT-LIVED AND
SPORADIC AT BEST. PLUS...MUCH OF THE PRECIP RETURNS ON RADAR IN
SOUTHERN MINNESOTA ARE NOT REACHING THE GROUND WITH ONLY A COUPLE
SPOTS REPORTING -SN ATTM.
WAA WILL CONTINUE THROUGH MUCH OF THE MORNING INTO THE EARLY
AFTERNOON AND UTILIZED A BLEND OF THE RAP/ECMWF FOR MAX TEMPS
TODAY. THE NAM/GFS/SREF SEEMED TOO COLD FOR MOST OF THE FORECAST
AREA. GOOD MIXING AND CLEARING SKIES SHOULD PUT TEMPS BACK IN THE
50S FOR THE SOUTHWEST SECTIONS OF THE CWA.
.LONG TERM /TONIGHT THROUGH SUNDAY/...
ISSUED AT 318 AM CST MON JAN 26 2015
MAIN THEMES FOR THE WEEK CONTINUE TO BE CLOUDS AND MILDER
TEMPERATURES THROUGH AT LEAST WEDNESDAY. BY LATE THIS AFTERNOON
THE APPROACHING SHORT WAVE SLIDING NEARLY DUE SOUTH TOWARD US WILL
BE EAST OF THE REGION WITH THE H500/H700 RIDGE BUILDING INTO THE
AREA TONIGHT. ALMOST IMMEDIATELY ANOTHER LEE SIDE TROUGH/BOUNDARY
WILL FORM ACROSS THE WESTERN PLAINS AND ENHANCE SOME CLOUDS OVER
THE REGION TONIGHT. THIS WILL KEEP TEMPERATURES FROM FALLING TOO
FAR WITH RATHER MILD READINGS FOR JANUARY IN THE 20S NORTHEAST TO
30S SOUTH. BY TOMORROW...GENERALLY LIGHT WINDS AT THE SFC AND
ALOFT WILL PROMOTE LITTLE MIXING WITH ANY WARMING SOLELY DUE TO
INSOLATION. THUS...TEMPERATURES WILL BE SLIGHTLY COOLER THAN TODAY
WITH A SUN CLOUD MIX. PATTERN FOR US REMAINS RATHER BENIGN FOR A
FEW MORE DAYS...COMPARED TO EAST COAST...AND WE SHOULD BEGIN A
NICE WARMING TREND AGAIN LATE TUESDAY NIGHT INTO WEDNESDAY.
BETWEEN 06 AND 12Z WED BOTH GFS/00Z EURO INDICATE STRONG WARM AIR
ADVECTION WILL STREAM ACROSS MOST OF IOWA. A SFC WAVE IS EXPECTED
TO TRACK NEAR OR OVER CENTRAL IOWA KEEPING THE AREA IN THE WARM
SECTOR THROUGH THE NOON HOUR. EURO H850 TEMPS WARM CONSIDERABLY TO
+10C TO +12C WITH GFS +6C TO +8C THROUGH 18Z WITH SOME COOLING IN
THE AFTERNOON FOR BOTH MODELS AS CLOUDS THICKEN. SIMILAR TO JAN
16TH...AM EXPECTING STRONG WARMING TO OUR SOUTHWEST WHICH WILL
GENERALLY NOT BE MODIFIED MUCH AS IT MOVES NORTHEAST INTO OUR
AREA. GUIDANCE CONTINUES TO LAG WARMTH POTENTIAL AS WITH PREVIOUS
SIMILAR EVENT. SUNDAY HIGHS TO OUR SOUTHWEST WERE ALREADY IN THE
LOWER TO MID 50S WITH 4C TO 6C H850 TEMPS. HAVE RAISED TMAX FOR
WED TO LOWER 40S NORTH TO UPPER 50S SOUTHWEST FOR NOW AND THIS MAY
BE TOO COOL. AFTER THE PASSAGE OF THE SFC LOW WED NIGHT ONE COLD
FRONT WILL PASS SOUTHEAST BY MORNING WITH A SECONDARY COLD FRONT
DRIVING SOUTH THROUGH THE AREA DURING THE DAY WITH A SECOND UPPER
LEVEL WAVE. THIS SHOULD RESULT IN CLOUDS AND LIGHT SNOW OR
FLURRIES OVER THE EAST DURING THE DAY. ONCE AGAIN EURO H850 WINDS
QUITE STRONG WITH 45 TO NEAR 50 KTS EARLY IN THE DAY REMAINING
NEAR 45KTS THROUGH EARLY AFTERNOON. LIKELY THAT SUSTAINED WINDS
WILL BE NEAR 2O TO 25 MPH WITH GUST POTENTIAL ABOVE 40 KTS.
DESPITE THE EURO SHOWING A STRONGER SOLN THAN THE 00Z GFS...GFS
BUFR SOUNDINGS CONTINUE TO SUPPORT NEARLY SIMILAR CONDITIONS. WITH
SOME UNCERTAINTY AND MINOR DIFFERENCES BETWEEN SOLNS...WILL
CONTINUE TO MONITOR OVER THE NEXT FEW MODEL PACKAGES. BREEZY DAY
NONE THE LESS. MORE WAVE ENERGY ROTATING SOUTHEAST FROM THE POLAR
ANCHOR LOW OVER HUDSON BAY CANADA WILL MOVE SOUTHEAST TOWARD THE
GREAT LAKES AND NORTHERN PLAINS BY SATURDAY AND LATE SUNDAY. THERE
IS MUCH MORE UNCERTAINTY REGARDING THE EVOLUTION OF THE H500
VORTEX AS IT DEEPENS AND EXPANDS SOUTHEAST TOWARD THE EASTERN
CONUS. THE 00Z EURO DROPS ONE ARCTIC FRONT INTO THE AREA SATURDAY
WITH A SECOND FRONT AND UPPER LEVEL H500 WAVE BY 12Z SUNDAY.
PROGGED H850 TEMPS PLUMMET TO -20C TO -26C MONDAY. NEITHER THE GEM
NOR THE GFS OPERATIONAL RUNS SUPPORT THE SAME COLD SOLUTION OF THE
EURO FOR NOW WITH THE EXCEPTION OF SOME OF THE MEX GUIDANCE
ENSEMBLE GUIDANCE WHICH SUGGEST THE POSSIBILITY OF COLDER
TEMPERATURES. IN FACT THE GEM DEVELOPS A DECENT STORM PASSING JUST
TO OUR EAST WHILE THE EURO SHEARS THE SYSTEM EAST THROUGH THE
SOUTHERN STREAM. WILL NEED TO EVALUATE OVER THE COMING DAYS AND
TAKE A MORE MODEST APPROACH TO TEMPERATURES FOR NOW AS PAST TWO
NIGHTS THERE HAS BEEN NO CONSISTENCY OVER THE WEEKEND...RESULTING
IN LOW CONFIDENCE AT THIS TIME. BETTER CLARITY IS EXPECTED IN THE
NEXT DAY OR TWO.
&&
.AVIATION...26/18Z
ISSUED AT 1140 AM CST MON JAN 26 2015
IFR/MVFR CIGS CURRENTLY OVER FAR EASTERN IOWA WITH THE WESTERN
EDGE NEAR KALO AND KOTM. EXPECT KOTM AND OTHER SITES TO REMAIN VFR
THROUGH THE AFTERNOON HOWEVER KALO WILL BE IMPACTED BY THE STRATUS
EARLY IN THE PERIOD. ANOTHER ROUND OF STRATUS OVER MINNESOTA WILL
ARRIVE TONIGHT. WINDS WILL BECOME WEST TO NW TODAY THEN GRADUALLY
SHIFT TO THE NORTHEAST ON TUESDAY.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...PODRAZIK
SHORT TERM...PODRAZIK
LONG TERM...REV
AVIATION...DONAVON
AREA FORECAST DISCUSSION
NWS DES MOINES IA
600 AM CST MON JAN 26 2015
...UPDATED DISCUSSION...
.UPDATE...
ISSUED AT 558 AM CST MON JAN 26 2015
INTRODUCED PATCHY FZDZ/FLURRIES BETWEEN HIGHWAY 20 TO HIGHWAY 34
AND GENERALLY EAST OF HIGHWAY 169 THROUGH 14Z WITH THE WEAK BAND
OF PRECIP QUICKLY MOVING SOUTH THAT IS JUST MOVING INTO THE FORT
DODGE AREA AS OF 6 AM. ALGONA AND FOREST CITY REPORTING UP...ONLY
CONFIRMING PRECIP IS FINALLY ABLE TO REACH THE SURFACE. SHOULD BE
VERY SHORT-LIVED AND LOOKS TO EXIT THE DSM METRO BY 730-8AM.
.SHORT TERM /TODAY/...
ISSUED AT 318 AM CST MON JAN 26 2015
QUICK MOVING SHORTWAVE LOOKS TO BRING SOME VERY LIGHT SNOW/FZDZ
TO NORTHERN AND EASTERN PORTIONS OF THE FORECAST THIS MORNING.
TIMING OF ANY PRECIP LOOKS TO BE FROM 10Z TO 14Z WITH SOME
LINGERING POPS THROUGH 15Z NEAR THE ALO AREA. LEANED TOWARD A
BLEND OF THE NAM12/RAP FOR POPS TODAY AND TOWARDS THE WARMER
RAP/ECMWF FOR TEMPS.
THE RAP AND NAM MCW/FOD SOUNDINGS HAVE A TOUGH TIME GETTING
COMPLETELY SATURATED AS THEY DEPICT A DEEP DRY LAYER BETWEEN 850-
650MB. CERTAINLY SATURATED BELOW 850MB AND ABOVE 650MB...SO SEEDER
FEEDER POTENTIAL EXISTS BUT FORCING WITHIN THE DENDRITIC LAYER IS
VERY WEAK AND ANY SNOW WILL HAVE A DIFFICULT TIME MAKING IT THROUGH
THIS DRY LAYER. IT MAY SNOW FOR A SHORT STINT BY AROUND 12Z-13Z
ONCE THE COLUMN COMPLETELY SATURATES NEAR MCW/ALO AREA BUT THE
RAP KEEPS THE DRY LAYER THROUGH THE ENTIRE MORNING. AS A
RESULT...WITH THE LACK OF ANY ICE INTRODUCTION...HAVE MENTION OF
FZDZ THIS MORNING. ONLY A MINOR TRAVEL CONCERN WITH THE FZDZ AS
EXPECTING WARMER TEMPERATURES LOOK TO ADVECT IN AND WITH THE VERY
QUICK MOVING SHORTWAVE...THE PRECIP SHOULD BE SHORT-LIVED AND
SPORADIC AT BEST. PLUS...MUCH OF THE PRECIP RETURNS ON RADAR IN
SOUTHERN MINNESOTA ARE NOT REACHING THE GROUND WITH ONLY A COUPLE
SPOTS REPORTING -SN ATTM.
WAA WILL CONTINUE THROUGH MUCH OF THE MORNING INTO THE EARLY
AFTERNOON AND UTILIZED A BLEND OF THE RAP/ECMWF FOR MAX TEMPS
TODAY. THE NAM/GFS/SREF SEEMED TOO COLD FOR MOST OF THE FORECAST
AREA. GOOD MIXING AND CLEARING SKIES SHOULD PUT TEMPS BACK IN THE
50S FOR THE SOUTHWEST SECTIONS OF THE CWA.
.LONG TERM /TONIGHT THROUGH SUNDAY/...
ISSUED AT 318 AM CST MON JAN 26 2015
MAIN THEMES FOR THE WEEK CONTINUE TO BE CLOUDS AND MILDER
TEMPERATURES THROUGH AT LEAST WEDNESDAY. BY LATE THIS AFTERNOON
THE APPROACHING SHORT WAVE SLIDING NEARLY DUE SOUTH TOWARD US WILL
BE EAST OF THE REGION WITH THE H500/H700 RIDGE BUILDING INTO THE
AREA TONIGHT. ALMOST IMMEDIATELY ANOTHER LEE SIDE TROUGH/BOUNDARY
WILL FORM ACROSS THE WESTERN PLAINS AND ENHANCE SOME CLOUDS OVER
THE REGION TONIGHT. THIS WILL KEEP TEMPERATURES FROM FALLING TOO
FAR WITH RATHER MILD READINGS FOR JANUARY IN THE 20S NORTHEAST TO
30S SOUTH. BY TOMORROW...GENERALLY LIGHT WINDS AT THE SFC AND
ALOFT WILL PROMOTE LITTLE MIXING WITH ANY WARMING SOLELY DUE TO
INSOLATION. THUS...TEMPERATURES WILL BE SLIGHTLY COOLER THAN TODAY
WITH A SUN CLOUD MIX. PATTERN FOR US REMAINS RATHER BENIGN FOR A
FEW MORE DAYS...COMPARED TO EAST COAST...AND WE SHOULD BEGIN A
NICE WARMING TREND AGAIN LATE TUESDAY NIGHT INTO WEDNESDAY.
BETWEEN 06 AND 12Z WED BOTH GFS/00Z EURO INDICATE STRONG WARM AIR
ADVECTION WILL STREAM ACROSS MOST OF IOWA. A SFC WAVE IS EXPECTED
TO TRACK NEAR OR OVER CENTRAL IOWA KEEPING THE AREA IN THE WARM
SECTOR THROUGH THE NOON HOUR. EURO H850 TEMPS WARM CONSIDERABLY TO
+10C TO +12C WITH GFS +6C TO +8C THROUGH 18Z WITH SOME COOLING IN
THE AFTERNOON FOR BOTH MODELS AS CLOUDS THICKEN. SIMILAR TO JAN
16TH...AM EXPECTING STRONG WARMING TO OUR SOUTHWEST WHICH WILL
GENERALLY NOT BE MODIFIED MUCH AS IT MOVES NORTHEAST INTO OUR
AREA. GUIDANCE CONTINUES TO LAG WARMTH POTENTIAL AS WITH PREVIOUS
SIMILAR EVENT. SUNDAY HIGHS TO OUR SOUTHWEST WERE ALREADY IN THE
LOWER TO MID 50S WITH 4C TO 6C H850 TEMPS. HAVE RAISED TMAX FOR
WED TO LOWER 40S NORTH TO UPPER 50S SOUTHWEST FOR NOW AND THIS MAY
BE TOO COOL. AFTER THE PASSAGE OF THE SFC LOW WED NIGHT ONE COLD
FRONT WILL PASS SOUTHEAST BY MORNING WITH A SECONDARY COLD FRONT
DRIVING SOUTH THROUGH THE AREA DURING THE DAY WITH A SECOND UPPER
LEVEL WAVE. THIS SHOULD RESULT IN CLOUDS AND LIGHT SNOW OR
FLURRIES OVER THE EAST DURING THE DAY. ONCE AGAIN EURO H850 WINDS
QUITE STRONG WITH 45 TO NEAR 50 KTS EARLY IN THE DAY REMAINING
NEAR 45KTS THROUGH EARLY AFTERNOON. LIKELY THAT SUSTAINED WINDS
WILL BE NEAR 2O TO 25 MPH WITH GUST POTENTIAL ABOVE 40 KTS.
DESPITE THE EURO SHOWING A STRONGER SOLN THAN THE 00Z GFS...GFS
BUFR SOUNDINGS CONTINUE TO SUPPORT NEARLY SIMILAR CONDITIONS. WITH
SOME UNCERTAINTY AND MINOR DIFFERENCES BETWEEN SOLNS...WILL
CONTINUE TO MONITOR OVER THE NEXT FEW MODEL PACKAGES. BREEZY DAY
NONE THE LESS. MORE WAVE ENERGY ROTATING SOUTHEAST FROM THE POLAR
ANCHOR LOW OVER HUDSON BAY CANADA WILL MOVE SOUTHEAST TOWARD THE
GREAT LAKES AND NORTHERN PLAINS BY SATURDAY AND LATE SUNDAY. THERE
IS MUCH MORE UNCERTAINTY REGARDING THE EVOLUTION OF THE H500
VORTEX AS IT DEEPENS AND EXPANDS SOUTHEAST TOWARD THE EASTERN
CONUS. THE 00Z EURO DROPS ONE ARCTIC FRONT INTO THE AREA SATURDAY
WITH A SECOND FRONT AND UPPER LEVEL H500 WAVE BY 12Z SUNDAY.
PROGGED H850 TEMPS PLUMMET TO -20C TO -26C MONDAY. NEITHER THE GEM
NOR THE GFS OPERATIONAL RUNS SUPPORT THE SAME COLD SOLUTION OF THE
EURO FOR NOW WITH THE EXCEPTION OF SOME OF THE MEX GUIDANCE
ENSEMBLE GUIDANCE WHICH SUGGEST THE POSSIBILITY OF COLDER
TEMPERATURES. IN FACT THE GEM DEVELOPS A DECENT STORM PASSING JUST
TO OUR EAST WHILE THE EURO SHEARS THE SYSTEM EAST THROUGH THE
SOUTHERN STREAM. WILL NEED TO EVALUATE OVER THE COMING DAYS AND
TAKE A MORE MODEST APPROACH TO TEMPERATURES FOR NOW AS PAST TWO
NIGHTS THERE HAS BEEN NO CONSISTENCY OVER THE WEEKEND...RESULTING
IN LOW CONFIDENCE AT THIS TIME. BETTER CLARITY IS EXPECTED IN THE
NEXT DAY OR TWO.
&&
.AVIATION...26/12Z
ISSUED AT 558 AM CST MON JAN 26 2015
IFR CIGS WILL QUICKLY DEPART AT MCW THIS MORNING...BUT MVFR CIGS
LOOK TO PERSIST THROUGH MUCH OF THE TAF PERIOD. DSM/FOD/OTM LIKELY
TO SEE A BREAK IN THE MVFR CIGS THIS AFTERNOON BUT LOW LEVEL
MOISTURE MOVES BACK IN WITH THE CAA TONIGHT AND HAVE MENTION OF
MVFR CIGS THROUGH THE END OF THE TAF PERIOD.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...REV
AVIATION...PODRAZIK
UPDATE...PODRAZIK
AREA FORECAST DISCUSSION
NWS DES MOINES IA
319 AM CST MON JAN 26 2015
.SHORT TERM /TODAY/...
ISSUED AT 318 AM CST MON JAN 26 2015
QUICK MOVING SHORTWAVE LOOKS TO BRING SOME VERY LIGHT SNOW/FZDZ
TO NORTHERN AND EASTERN PORTIONS OF THE FORECAST THIS MORNING.
TIMING OF ANY PRECIP LOOKS TO BE FROM 10Z TO 14Z WITH SOME
LINGERING POPS THROUGH 15Z NEAR THE ALO AREA. LEANED TOWARD A
BLEND OF THE NAM12/RAP FOR POPS TODAY AND TOWARDS THE WARMER
RAP/ECMWF FOR TEMPS.
THE RAP AND NAM MCW/FOD SOUNDINGS HAVE A TOUGH TIME GETTING
COMPLETELY SATURATED AS THEY DEPICT A DEEP DRY LAYER BETWEEN 850-
650MB. CERTAINLY SATURATED BELOW 850MB AND ABOVE 650MB...SO SEEDER
FEEDER POTENTIAL EXISTS BUT FORCING WITHIN THE DENDRITIC LAYER IS
VERY WEAK AND ANY SNOW WILL HAVE A DIFFICULT TIME MAKING IT THROUGH
THIS DRY LAYER. IT MAY SNOW FOR A SHORT STINT BY AROUND 12Z-13Z ONCE
THE COLUMN COMPLETELY SATURATES NEAR MCW/ALO AREA BUT THE RAP KEEPS
THE DRY LAYER THROUGH THE ENTIRE MORNING. AS A RESULT...WITH THE
LACK OF ANY ICE INTRODUCTION...HAVE MENTION OF FZDZ THIS MORNING.
ONLY A MINOR TRAVEL CONCERN WITH THE FZDZ AS EXPECTING WARMER
TEMPERATURES LOOK TO ADVECT IN AND WITH THE VERY QUICK MOVING
SHORTWAVE...THE PRECIP SHOULD BE SHORT-LIVED AND SPORADIC AT BEST.
PLUS...MUCH OF THE PRECIP RETURNS ON RADAR IN SOUTHERN MINNESOTA ARE
NOT REACHING THE GROUND WITH ONLY A COUPLE SPOTS REPORTING -SN
ATTM.
WAA WILL CONTINUE THROUGH MUCH OF THE MORNING INTO THE EARLY
AFTERNOON AND UTILIZED A BLEND OF THE RAP/ECMWF FOR MAX TEMPS TODAY.
THE NAM/GFS/SREF SEEMED TOO COLD FOR MOST OF THE FORECAST AREA. GOOD
MIXING AND CLEARING SKIES SHOULD PUT TEMPS BACK IN THE 50S FOR THE
SOUTHWEST SECTIONS OF THE CWA.
.LONG TERM /TONIGHT THROUGH SUNDAY/...
ISSUED AT 318 AM CST MON JAN 26 2015
MAIN THEMES FOR THE WEEK CONTINUE TO BE CLOUDS AND MILDER TEMPERATURES
THROUGH AT LEAST WEDNESDAY. BY LATE THIS AFTERNOON THE APPROACHING
SHORT WAVE SLIDING NEARLY DUE SOUTH TOWARD US WILL BE EAST OF THE
REGION WITH THE H500/H700 RIDGE BUILDING INTO THE AREA TONIGHT.
ALMOST IMMEDIATELY ANOTHER LEE SIDE TROUGH/BOUNDARY WILL FORM
ACROSS THE WESTERN PLAINS AND ENHANCE SOME CLOUDS OVER THE REGION
TONIGHT. THIS WILL KEEP TEMPERATURES FROM FALLING TOO FAR WITH
RATHER MILD READINGS FOR JANUARY IN THE 20S NORTHEAST TO 30S
SOUTH. BY TOMORROW...GENERALLY LIGHT WINDS AT THE SFC AND ALOFT
WILL PROMOTE LITTLE MIXING WITH ANY WARMING SOLELY DUE TO
INSOLATION. THUS...TEMPERATURES WILL BE SLIGHTLY COOLER THAN TODAY
WITH A SUN CLOUD MIX. PATTERN FOR US REMAINS RATHER BENIGN FOR A
FEW MORE DAYS...COMPARED TO EAST COAST...AND WE SHOULD BEGIN A
NICE WARMING TREND AGAIN LATE TUESDAY NIGHT INTO WEDNESDAY.
BETWEEN 06 AND 12Z WED BOTH GFS/00Z EURO INDICATE STRONG WARM AIR
ADVECTION WILL STREAM ACROSS MOST OF IOWA. A SFC WAVE IS EXPECTED
TO TRACK NEAR OR OVER CENTRAL IOWA KEEPING THE AREA IN THE WARM
SECTOR THROUGH THE NOON HOUR. EURO H850 TEMPS WARM CONSIDERABLY TO
+10C TO +12C WITH GFS +6C TO +8C THROUGH 18Z WITH SOME COOLING IN
THE AFTERNOON FOR BOTH MODELS AS CLOUDS THICKEN. SIMILAR TO JAN
16TH...AM EXPECTING STRONG WARMING TO OUR SOUTHWEST WHICH WILL
GENERALLY NOT BE MODIFIED MUCH AS IT MOVES NORTHEAST INTO OUR
AREA. GUIDANCE CONTINUES TO LAG WARMTH POTENTIAL AS WITH PREVIOUS
SIMILAR EVENT. SUNDAY HIGHS TO OUR SOUTHWEST WERE ALREADY IN THE
LOWER TO MID 50S WITH 4C TO 6C H850 TEMPS. HAVE RAISED TMAX FOR
WED TO LOWER 40S NORTH TO UPPER 50S SOUTHWEST FOR NOW AND THIS MAY
BE TOO COOL. AFTER THE PASSAGE OF THE SFC LOW WED NIGHT ONE COLD
FRONT WILL PASS SOUTHEAST BY MORNING WITH A SECONDARY COLD FRONT
DRIVING SOUTH THROUGH THE AREA DURING THE DAY WITH A SECOND UPPER
LEVEL WAVE. THIS SHOULD RESULT IN CLOUDS AND LIGHT SNOW OR
FLURRIES OVER THE EAST DURING THE DAY. ONCE AGAIN EURO H850 WINDS
QUITE STRONG WITH 45 TO NEAR 50 KTS EARLY IN THE DAY REMAINING
NEAR 45KTS THROUGH EARLY AFTERNOON. LIKELY THAT SUSTAINED WINDS
WILL BE NEAR 2O TO 25 MPH WITH GUST POTENTIAL ABOVE 40 KTS.
DESPITE THE EURO SHOWING A STRONGER SOLN THAN THE 00Z GFS...GFS
BUFR SOUNDINGS CONTINUE TO SUPPORT NEARLY SIMILAR CONDITIONS. WITH
SOME UNCERTAINTY AND MINOR DIFFERENCES BETWEEN SOLNS...WILL
CONTINUE TO MONITOR OVER THE NEXT FEW MODEL PACKAGES. BREEZY DAY
NONE THE LESS. MORE WAVE ENERGY ROTATING SOUTHEAST FROM THE POLAR
ANCHOR LOW OVER HUDSON BAY CANADA WILL MOVE SOUTHEAST TOWARD THE
GREAT LAKES AND NORTHERN PLAINS BY SATURDAY AND LATE SUNDAY. THERE
IS MUCH MORE UNCERTAINTY REGARDING THE EVOLUTION OF THE H500
VORTEX AS IT DEEPENS AND EXPANDS SOUTHEAST TOWARD THE EASTERN
CONUS. THE 00Z EURO DROPS ONE ARCTIC FRONT INTO THE AREA SATURDAY
WITH A SECOND FRONT AND UPPER LEVEL H500 WAVE BY 12Z SUNDAY.
PROGGED H850 TEMPS PLUMMET TO -20C TO -26C MONDAY. NEITHER THE GEM
NOR THE GFS OPERATIONAL RUNS SUPPORT THE SAME COLD SOLUTION OF THE
EURO FOR NOW WITH THE EXCEPTION OF SOME OF THE MEX GUIDANCE
ENSEMBLE GUIDANCE WHICH SUGGEST THE POSSIBILITY OF COLDER
TEMPERATURES. IN FACT THE GEM DEVELOPS A DECENT STORM PASSING JUST
TO OUR EAST WHILE THE EURO SHEARS THE SYSTEM EAST THROUGH THE
SOUTHERN STREAM. WILL NEED TO EVALUATE OVER THE COMING DAYS AND
TAKE A MORE MODEST APPROACH TO TEMPERATURES FOR NOW AS PAST TWO
NIGHTS THERE HAS BEEN NO CONSISTENCY OVER THE WEEKEND...RESULTING
IN LOW CONFIDENCE AT THIS TIME. BETTER CLARITY IS EXPECTED IN THE
NEXT DAY OR TWO.
&&
.AVIATION...26/06Z
ISSUED AT 1133 PM CST SUN JAN 25 2015
LOW STRATUS WILL KEEP LOW MVFR CEILINGS AT SITES THROUGH MOST OF
PERIOD. NORTHER SITES...KMCW AND KALO MAY SEE CEILINGS DROP TO
IFR BRIEFLY BETWEEN 06Z-12Z AS SYSTEM PUSHES SOUTH.
HOWEVER...BELIEVE IFR CEILINGS WILL BE BRIEF. WESTERN SITES KFOD
AND KDSM WILL SEE IMPROVEMENT TO VFR NEAR 18Z...THOUGH EASTERN
SITES WILL REMAIN MVFR THROUGH MOST OF PERIOD...LIFTING NEAR
00Z...THOUGH MAY HAVE BEEN TOO OPTIMISTIC WITH IMPROVEMENT OF
CEILINGS. WINDS WILL SHIFT TO THE NORTHWEST BY 18Z AND WILL BE
STRONG...NEAR 15 KTS THROUGH AFTERNOON AT SITES.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...REV
AVIATION...AWB
AREA FORECAST DISCUSSION
NWS JACKSON KY
110 PM EST MON JAN 26 2015
.UPDATE...
ISSUED AT 1155 AM EST MON JAN 26 2015
THE BAND OF STEADIER SNOW CONTINUES TO WORK ACROSS THE SOUTHEASTERN
COUNTIES WITH SOME LIGHT SNOW AND FLURRIES ON UPSLOPE FLOW/INSTABILITY
LINGERING BEHIND THIS. SOME OF THIS LIGHTER SNOW AND FLURRIES ARE
BELOW THE RADAR BEAM...SO THE AREAL EXTENT AT THIS TIME MAY BE A BIT
GREATER THAN INDICATED BY RADAR. THE TEMPERATURES ARE GENERALLY
RUNNING BELOW GUIDANCE ONCE THE COLDER AIR MOVES IN AND WE CURRENTLY
EXPECT TEMPERATURES TO RECOVER ONLY A DEGREE OR TWO THE REMAINDER OF
THE DAY...SO NEARLY STEADY TEMPERATURES ARE EXPECTED IN MOST
PLACES...WITH A BUMP DOWN IN THE DEEPEST VALLEYS IN THE FAR SOUTHEAST
AND THEN NEARLY STEADY FOR THE REST OF THE DAY.
NORTHWEST FLOW AN ADDITIONAL DISTURBANCES PASSING BY WILL LEAD TO
ISOLATED TO SCATTERED SNOW SHOWERS AND FLURRIES THROUGH AT LEAST
TONIGHT. ADDITIONAL SNOW ACCUMULATIONS WILL BE LIGHT GENERALLY LESS
THAN A HALF OF AN INCH. HOWEVER...THE NEARLY STEADY TEMPERATURES
BELOW FREEZING AND SOME LIGHT FALLING PRECIP SHOULD ACT TO COOL
ROADWAYS AND SURFACES AND SLICK OR REFREEZE SPOTS ARE ANTICIPATED AT
TIMES ESPECIALLY ON ANY UNTREATED LOCATIONS. THESE COULD BECOME MORE
PREVALENT BY DARK...DEPENDING ON WHERE SNOW SHOWERS AND FLURRIES
OCCUR. AN SPS HAS BEEN REISSUED TO HANDLE THIS AND GRAPHICAL NOWCASTS
WILL CONTINUE TO BE ISSUED THIS AFTERNOON TO ADDRESS THIS.
UPDATE ISSUED AT 647 AM EST MON JAN 26 2015
WSR-88D RADAR SHOWS A FEW SHOWERS AND SNOW SHOWERS MOVING ACROSS THE
REGION THE MORNING AS CLIPPER LOW CONTINUES TO PROGRESS ACROSS
EASTERN KY. THE TEMPERATURES HAVE BEEN TRICKY OVERNIGHT INTO THIS
MORNING AS COLDER AIR CONTINUES TO SLOWLY ADVECT FROM NW TO SE THIS
MORNING. FRESHENED UP GRIDS WITH LATEST OBS AND TRENDS THIS MORNING
INCLUDING A QUICK UPDATE OF WX GRIDS TO BETTER SHOW TRANSITION THIS
MORNING.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 342 AM EST MON JAN 26 2015
WSR-88D THIS MORNING HAS CONTINUED TO SHOW AREAS OF RAIN SHOWERS
MOVING ACROSS EASTERN KY THIS MORNING. BEST COVERAGE HAS GENERALLY
BEEN ACROSS THE FAR SOUTHERN PORTIONS OF THE REGION THIS MORNING.
HOWEVER THIS MORNING WE HAVE SEEN GENERALLY LOWER AMTS OF PRECIP AND
TEMPS ARE STILL ABOVE FREEZING AT MOST LOCATIONS BESIDE BLACK MTN AT
8Z. GIVEN THIS HAVE LESSEN POPS AND ALSO LESSENED QPF AMTS ACROSS THE
REGION. THIS MAY STILL BE TOO OPTIMISTIC AS RETURNS FROM RADAR HAVE
BEEN QUITE LOW ACROSS CENTRAL AND WESTERN KY THIS MORNING. THIS TREND
OF LOWERING REFLECTIVITIES IS ALSO BACK UP BY THE HRRR WHICH ALSO
INITIALIZED FAIRLY WELL AT 7Z. OTHERWISE LEFT OVER SHOWERS WILL SLOWLY
TRANSITION TO SNOW SHOWERS THROUGH THE DAY WITH BEST COVERAGE ACROSS
THE FAR EAST THIS AFTERNOON.
THIS SURFACE LOW AND UPPER LEVEL TROUGH WILL CONTINUE EXIT EAST WHERE
IT DEVELOPS INTO A STRONG NOREASTER ALONG THE ATLANTIC SEABOARD LATER
TODAY. ACROSS EASTERN KY WE WILL CONTINUE TO TRANSITION TO GENERALLY
WEST TO NW FLOW. MODELS DO SHOW A FETCH OF MOISTURE DROPPING SOUTH
FROM THE GREAT LAKES TONIGHT INTO TUESDAY. RIGHT NOW HAVE MOVED
TOWARD SLIGHT CHANCES OF SNOW SHOWERS MAINLY ACROSS SW PORTION OF THE
CWA WHERE BETTER PLACEMENT OF MOISTURE AXIS EXISTS. EVEN SO GENERALLY
MOSTLY CLOUDY CONDITIONS WILL PREVAIL FOR MUCH OF THE PERIOD AREA
WIDE COUPLED WITH GENERALLY BELOW NORMAL TEMPS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 445 AM EST MON JAN 26 2015
THE MODELS ARE IN GOOD AGREEMENT ALOFT FOR THE FIRST PART OF THE
EXTENDED AND ARE IN FAIR AGREEMENT WITH THE LATTER PART. THE RUB HERE
IS THAT THE CONSISTENCY HAS BEEN TAKING HITS LATELY WITH THE FORECAST
FOR NEXT WEEKEND. A ONCE DISCARDED SOLUTION...MAINLY SEEN EARLIER IN
THE GFS...HAS RETURNED WITH SOME LIMITED SUPPORT FROM THE ECMWF.
EARLY ON...THE FOCUS WILL BE ON A DEEP CYCLONE OFF THE EASTERN
SEABOARD WHILE A FAST FLOW OF ENERGY ROILS ABOVE EAST KENTUCKY ON A
GENERALLY NORTHWEST TO SOUTHEAST PATH INTO WEDNESDAY MORNING. THIS
VORT STREAM IS SHUNTED EAST BY MIDDAY WEDNESDAY AS HIGHER HEIGHTS
FROM A WEAKENING SOUTHERN RIDGE MOVES INTO THE MID MISSISSIPPI
VALLEY AND THEN OVER THE LOWER OHIO BASIN. AT THE SAME TIME...A
DEVELOPING TROUGH WILL DIP INTO THE CENTRAL PLAINS AND SLIDE EAST.
THIS FEATURE RAMPS UP INTO THE DAY THURSDAY WITH THE GFS PROVIDING
BETTER SUPPORT FOR THE MORE ROBUST SOLUTION OF THE ECMWF. THIS
TROUGH CROSSES EAST KENTUCKY LATER THURSDAY NIGHT WITH FLAT FLOW TO
FOLLOW. HOWEVER...OVER THE SOUTHWEST PARTS OF THE NATION A LARGE
CLOSED LOW IN THE SOUTHERN STREAM IS NOW DEPICTED...PARTICULARLY BY
THE LATEST ECMWF...OPENING UP AND SPILLING ITS ENERGY EAST INTO THE
FLOW RIDING OVER THE TENNESSEE VALLEY. THE MODELS NOW 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. IN GENERAL...A BLEND
OF THE MODELS WAS PREFERRED THROUGH THE BULK OF THE FORECAST WITH
SOME ADJUSTMENT TOWARD THE PREVIOUS FORECAST FOR NEXT WEEKEND GIVEN
THE CONSISTENCY CONCERNS.
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 INTO FRIDAY MORNING. ONLY A BRIEF WINDOW FOR DRYING CAN BE
EXPECTED FROM FRIDAY NIGHT INTO SATURDAY MORNING 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
SUNDAY MORNING WITH SNOW CHANCES CONTINUING...MAINLY IN THE SOUTHERN
PARTS OF THE CWA. THIS SETUP WILL NEED TO BE WATCHED CLOSELY...
THOUGH...AS THE POTENTIAL EXISTS FOR THE COLD AIR TO SETTLE INTO THE
STATE BY LATE IN THE WEEKEND AND A LOW TO FORM IN THE NORTHERN GULF
SLIDING NORTHEAST WHILE SENDING AMPLE MOISTURE NORTH INTO OUR AREA
ON THE COLD SIDE OF THIS ARCTIC BOUNDARY. FOR NOW...HAVE GONE WITH
JUST SMALL CHANCES FOR SNOW FROM SATURDAY AFTERNOON THROUGH SUNDAY...
BUT THAT WILL SURELY NEED TO BE ADJUSTED ONE WAY OR ANOTHER AS THE
MODELS GET A BETTER HANDLE ON THIS SITUATION IN FUTURE RUNS.
THE CR GRID LOAD MADE FOR AN OKAY START TO THE EXTENDED FORECAST
GRIDS WITH CHANGES MADE PRIMARILY TO BETTER REFLECT THE LATEST ECMWF
SOLUTION FOR THE UPCOMING WEEKEND. ALSO...MADE SOME TYPICAL RIDGE
AND VALLEY TEMPERATURE ADJUSTMENTS FOR LOWS EACH NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 109 PM EST MON JAN 26 2015
EXPECT VARYING CIGS THROUGH THE EVENING AND INTO TONIGHT AS SOME
UPSLOPE SNOW SHOWERS CONTINUE TO MOVE THROUGH THE AREA. WITH
THIS...ACTIVITY...CIGS WILL GENERALLY BE AT AIRFIELD MINS OR JUST
ABOVE FOR THE TAF SITES. VISIBILITY REDUCTIONS WILL BE SHORT IN
DURATION DUE TO THE SHOWERY NATURE OF THE SNOW SHOWERS THIS EVENING.
A BRIEF BREAK IN THE ACTIVITY WILL OCCUR AROUND 00Z THROUGH 06Z
TONIGHT BEFORE THE NEXT SHORT WAVE MOVES THROUGH AND BRINGS ANOTHER
ROUND OF SNOW SHOWERS TUESDAY MORNING INTO THE AFTERNOON. WINDS WILL
GENERALLY BE OUT OF THE WEST AND NORTHWEST THROUGH THE PERIOD WITH
SOME GUSTS TO 20 KNOTS AT TIMES THROUGH THIS EVENING AND TONIGHT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...DJ
LONG TERM...GREIF
AVIATION...JVM/SHALLENBERGER
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1205 PM EST MON JAN 26 2015
.UPDATE...
ISSUED AT 1155 AM EST MON JAN 26 2015
THE BAND OF STEADIER SNOW CONTINUES TO WORK ACROSS THE SOUTHEASTERN
COUNTIES WITH SOME LIGHT SNOW AND FLURRIES ON UPSLOPE FLOW/INSTABILITY
LINGERING BEHIND THIS. SOME OF THIS LIGHTER SNOW AND FLURRIES ARE
BELOW THE RADAR BEAM...SO THE AREAL EXTENT AT THIS TIME MAY BE A BIT
GREATER THAN INDICATED BY RADAR. THE TEMPERATURES ARE GENERALLY
RUNNING BELOW GUIDANCE ONCE THE COLDER AIR MOVES IN AND WE CURRENTLY
EXPECT TEMPERATURES TO RECOVER ONLY A DEGREE OR TWO THE REMAINDER OF
THE DAY...SO NEARLY STEADY TEMPERATURES ARE EXPECTED IN MOST
PLACES...WITH A BUMP DOWN IN THE DEEPEST VALLEYS IN THE FAR SOUTHEAST
AND THEN NEARLY STEADY FOR THE REST OF THE DAY.
NORTHWEST FLOW AN ADDITIONAL DISTURBANCES PASSING BY WILL LEAD TO
ISOLATED TO SCATTERED SNOW SHOWERS AND FLURRIES THROUGH AT LEAST
TONIGHT. ADDITIONAL SNOW ACCUMULATIONS WILL BE LIGHT GENERALLY LESS
THAN A HALF OF AN INCH. HOWEVER...THE NEARLY STEADY TEMPERATURES
BELOW FREEZING AND SOME LIGHT FALLING PRECIP SHOULD ACT TO COOL
ROADWAYS AND SURFACES AND SLICK OR REFREEZE SPOTS ARE ANTICIPATED AT
TIMES ESPECIALLY ON ANY UNTREATED LOCATIONS. THESE COULD BECOME MORE
PREVALENT BY DARK...DEPENDING ON WHERE SNOW SHOWERS AND FLURRIES
OCCUR. AN SPS HAS BEEN REISSUED TO HANDLE THIS AND GRAPHICAL NOWCASTS
WILL CONTINUE TO BE ISSUED THIS AFTERNOON TO ADDRESS THIS.
UPDATE ISSUED AT 647 AM EST MON JAN 26 2015
WSR-88D RADAR SHOWS A FEW SHOWERS AND SNOW SHOWERS MOVING ACROSS THE
REGION THE MORNING AS CLIPPER LOW CONTINUES TO PROGRESS ACROSS
EASTERN KY. THE TEMPERATURES HAVE BEEN TRICKY OVERNIGHT INTO THIS
MORNING AS COLDER AIR CONTINUES TO SLOWLY ADVECT FROM NW TO SE THIS
MORNING. FRESHENED UP GRIDS WITH LATEST OBS AND TRENDS THIS MORNING
INCLUDING A QUICK UPDATE OF WX GRIDS TO BETTER SHOW TRANSITION THIS
MORNING.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 342 AM EST MON JAN 26 2015
WSR-88D THIS MORNING HAS CONTINUED TO SHOW AREAS OF RAIN SHOWERS
MOVING ACROSS EASTERN KY THIS MORNING. BEST COVERAGE HAS GENERALLY
BEEN ACROSS THE FAR SOUTHERN PORTIONS OF THE REGION THIS MORNING.
HOWEVER THIS MORNING WE HAVE SEEN GENERALLY LOWER AMTS OF PRECIP AND
TEMPS ARE STILL ABOVE FREEZING AT MOST LOCATIONS BESIDE BLACK MTN AT
8Z. GIVEN THIS HAVE LESSEN POPS AND ALSO LESSENED QPF AMTS ACROSS THE
REGION. THIS MAY STILL BE TOO OPTIMISTIC AS RETURNS FROM RADAR HAVE
BEEN QUITE LOW ACROSS CENTRAL AND WESTERN KY THIS MORNING. THIS TREND
OF LOWERING REFLECTIVITIES IS ALSO BACK UP BY THE HRRR WHICH ALSO
INITIALIZED FAIRLY WELL AT 7Z. OTHERWISE LEFT OVER SHOWERS WILL SLOWLY
TRANSITION TO SNOW SHOWERS THROUGH THE DAY WITH BEST COVERAGE ACROSS
THE FAR EAST THIS AFTERNOON.
THIS SURFACE LOW AND UPPER LEVEL TROUGH WILL CONTINUE EXIT EAST WHERE
IT DEVELOPS INTO A STRONG NOREASTER ALONG THE ATLANTIC SEABOARD LATER
TODAY. ACROSS EASTERN KY WE WILL CONTINUE TO TRANSITION TO GENERALLY
WEST TO NW FLOW. MODELS DO SHOW A FETCH OF MOISTURE DROPPING SOUTH
FROM THE GREAT LAKES TONIGHT INTO TUESDAY. RIGHT NOW HAVE MOVED
TOWARD SLIGHT CHANCES OF SNOW SHOWERS MAINLY ACROSS SW PORTION OF THE
CWA WHERE BETTER PLACEMENT OF MOISTURE AXIS EXISTS. EVEN SO GENERALLY
MOSTLY CLOUDY CONDITIONS WILL PREVAIL FOR MUCH OF THE PERIOD AREA
WIDE COUPLED WITH GENERALLY BELOW NORMAL TEMPS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 445 AM EST MON JAN 26 2015
THE MODELS ARE IN GOOD AGREEMENT ALOFT FOR THE FIRST PART OF THE
EXTENDED AND ARE IN FAIR AGREEMENT WITH THE LATTER PART. THE RUB HERE
IS THAT THE CONSISTENCY HAS BEEN TAKING HITS LATELY WITH THE FORECAST
FOR NEXT WEEKEND. A ONCE DISCARDED SOLUTION...MAINLY SEEN EARLIER IN
THE GFS...HAS RETURNED WITH SOME LIMITED SUPPORT FROM THE ECMWF.
EARLY ON...THE FOCUS WILL BE ON A DEEP CYCLONE OFF THE EASTERN
SEABOARD WHILE A FAST FLOW OF ENERGY ROILS ABOVE EAST KENTUCKY ON A
GENERALLY NORTHWEST TO SOUTHEAST PATH INTO WEDNESDAY MORNING. THIS
VORT STREAM IS SHUNTED EAST BY MIDDAY WEDNESDAY AS HIGHER HEIGHTS
FROM A WEAKENING SOUTHERN RIDGE MOVES INTO THE MID MISSISSIPPI
VALLEY AND THEN OVER THE LOWER OHIO BASIN. AT THE SAME TIME...A
DEVELOPING TROUGH WILL DIP INTO THE CENTRAL PLAINS AND SLIDE EAST.
THIS FEATURE RAMPS UP INTO THE DAY THURSDAY WITH THE GFS PROVIDING
BETTER SUPPORT FOR THE MORE ROBUST SOLUTION OF THE ECMWF. THIS
TROUGH CROSSES EAST KENTUCKY LATER THURSDAY NIGHT WITH FLAT FLOW TO
FOLLOW. HOWEVER...OVER THE SOUTHWEST PARTS OF THE NATION A LARGE
CLOSED LOW IN THE SOUTHERN STREAM IS NOW DEPICTED...PARTICULARLY BY
THE LATEST ECMWF...OPENING UP AND SPILLING ITS ENERGY EAST INTO THE
FLOW RIDING OVER THE TENNESSEE VALLEY. THE MODELS NOW 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. IN GENERAL...A BLEND
OF THE MODELS WAS PREFERRED THROUGH THE BULK OF THE FORECAST WITH
SOME ADJUSTMENT TOWARD THE PREVIOUS FORECAST FOR NEXT WEEKEND GIVEN
THE CONSISTENCY CONCERNS.
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 INTO FRIDAY MORNING. ONLY A BRIEF WINDOW FOR DRYING CAN BE
EXPECTED FROM FRIDAY NIGHT INTO SATURDAY MORNING 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
SUNDAY MORNING WITH SNOW CHANCES CONTINUING...MAINLY IN THE SOUTHERN
PARTS OF THE CWA. THIS SETUP WILL NEED TO BE WATCHED CLOSELY...
THOUGH...AS THE POTENTIAL EXISTS FOR THE COLD AIR TO SETTLE INTO THE
STATE BY LATE IN THE WEEKEND AND A LOW TO FORM IN THE NORTHERN GULF
SLIDING NORTHEAST WHILE SENDING AMPLE MOISTURE NORTH INTO OUR AREA
ON THE COLD SIDE OF THIS ARCTIC BOUNDARY. FOR NOW...HAVE GONE WITH
JUST SMALL CHANCES FOR SNOW FROM SATURDAY AFTERNOON THROUGH SUNDAY...
BUT THAT WILL SURELY NEED TO BE ADJUSTED ONE WAY OR ANOTHER AS THE
MODELS GET A BETTER HANDLE ON THIS SITUATION IN FUTURE RUNS.
THE CR GRID LOAD MADE FOR AN OKAY START TO THE EXTENDED FORECAST
GRIDS WITH CHANGES MADE PRIMARILY TO BETTER REFLECT THE LATEST ECMWF
SOLUTION FOR THE UPCOMING WEEKEND. ALSO...MADE SOME TYPICAL RIDGE
AND VALLEY TEMPERATURE ADJUSTMENTS FOR LOWS EACH NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 632 AM EST MON JAN 26 2015
MOST SITES HAVE COME DOWN THIS MORNING TO IFR AND LIFR CONDITIONS. A
FEW SITES ARE SEEING LOWER VIS DUE TO FOG AND/OR SHOWER ACTIVITY MOVING
ACROSS THOSE SITES. COLDER AIR IS SLOWING MOVING INTO THE REGION THIS
MORNING AND WILL TRANSITION RAIN SHOWERS TO SNOW SHOWERS AS WE GO
THROUGH THE MORNING. OTHERWISE A FEW SITES ARE SEEING GUSTY WINDS
AROUND 15 TO 20 KTS AS WINDS BEGIN SWITCHING WEST TO NORTHWEST
THROUGH THE DAY AS LOW CONTINUES TO EXIT TO THE EAST. OTHERWISE SITES
ARE EXPECTED TO IMPROVE LATER THIS AFTERNOON AS DRIER AIR CONTINUES
TO FILTER INTO EASTERN KY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...DJ
LONG TERM...GREIF
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
648 AM EST MON JAN 26 2015
.UPDATE...
ISSUED AT 647 AM EST MON JAN 26 2015
WSR-88D RADAR SHOWS A FEW SHOWERS AND SNOW SHOWERS MOVING ACROSS THE
REGION THE MORNING AS CLIPPER LOW CONTINUES TO PROGRESS ACROSS
EASTERN KY. THE TEMPERATURES HAVE BEEN TRICKY OVERNIGHT INTO THIS
MORNING AS COLDER AIR CONTINUES TO SLOWLY ADVECT FROM NW TO SE THIS
MORNING. FRESHENED UP GRIDS WITH LATEST OBS AND TRENDS THIS MORNING
INCLUDING A QUICK UPDATE OF WX GRIDS TO BETTER SHOW TRANSITION THIS
MORNING.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 342 AM EST MON JAN 26 2015
WSR-88D THIS MORNING HAS CONTINUED TO SHOW AREAS OF RAIN SHOWERS
MOVING ACROSS EASTERN KY THIS MORNING. BEST COVERAGE HAS GENERALLY
BEEN ACROSS THE FAR SOUTHERN PORTIONS OF THE REGION THIS MORNING.
HOWEVER THIS MORNING WE HAVE SEEN GENERALLY LOWER AMTS OF PRECIP AND
TEMPS ARE STILL ABOVE FREEZING AT MOST LOCATIONS BESIDE BLACK MTN AT
8Z. GIVEN THIS HAVE LESSEN POPS AND ALSO LESSENED QPF AMTS ACROSS THE
REGION. THIS MAY STILL BE TOO OPTIMISTIC AS RETURNS FROM RADAR HAVE
BEEN QUITE LOW ACROSS CENTRAL AND WESTERN KY THIS MORNING. THIS TREND
OF LOWERING REFLECTIVITIES IS ALSO BACK UP BY THE HRRR WHICH ALSO
INITIALIZED FAIRLY WELL AT 7Z. OTHERWISE LEFT OVER SHOWERS WILL SLOWLY
TRANSITION TO SNOW SHOWERS THROUGH THE DAY WITH BEST COVERAGE ACROSS
THE FAR EAST THIS AFTERNOON.
THIS SURFACE LOW AND UPPER LEVEL TROUGH WILL CONTINUE EXIT EAST WHERE
IT DEVELOPS INTO A STRONG NOREASTER ALONG THE ATLANTIC SEABOARD LATER
TODAY. ACROSS EASTERN KY WE WILL CONTINUE TO TRANSITION TO GENERALLY
WEST TO NW FLOW. MODELS DO SHOW A FETCH OF MOISTURE DROPPING SOUTH
FROM THE GREAT LAKES TONIGHT INTO TUESDAY. RIGHT NOW HAVE MOVED
TOWARD SLIGHT CHANCES OF SNOW SHOWERS MAINLY ACROSS SW PORTION OF THE
CWA WHERE BETTER PLACEMENT OF MOISTURE AXIS EXISTS. EVEN SO GENERALLY
MOSTLY CLOUDY CONDITIONS WILL PREVAIL FOR MUCH OF THE PERIOD AREA
WIDE COUPLED WITH GENERALLY BELOW NORMAL TEMPS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 445 AM EST MON JAN 26 2015
THE MODELS ARE IN GOOD AGREEMENT ALOFT FOR THE FIRST PART OF THE
EXTENDED AND ARE IN FAIR AGREEMENT WITH THE LATTER PART. THE RUB HERE
IS THAT THE CONSISTENCY HAS BEEN TAKING HITS LATELY WITH THE FORECAST
FOR NEXT WEEKEND. A ONCE DISCARDED SOLUTION...MAINLY SEEN EARLIER IN
THE GFS...HAS RETURNED WITH SOME LIMITED SUPPORT FROM THE ECMWF.
EARLY ON...THE FOCUS WILL BE ON A DEEP CYCLONE OFF THE EASTERN
SEABOARD WHILE A FAST FLOW OF ENERGY ROILS ABOVE EAST KENTUCKY ON A
GENERALLY NORTHWEST TO SOUTHEAST PATH INTO WEDNESDAY MORNING. THIS
VORT STREAM IS SHUNTED EAST BY MIDDAY WEDNESDAY AS HIGHER HEIGHTS
FROM A WEAKENING SOUTHERN RIDGE MOVES INTO THE MID MISSISSIPPI
VALLEY AND THEN OVER THE LOWER OHIO BASIN. AT THE SAME TIME...A
DEVELOPING TROUGH WILL DIP INTO THE CENTRAL PLAINS AND SLIDE EAST.
THIS FEATURE RAMPS UP INTO THE DAY THURSDAY WITH THE GFS PROVIDING
BETTER SUPPORT FOR THE MORE ROBUST SOLUTION OF THE ECMWF. THIS
TROUGH CROSSES EAST KENTUCKY LATER THURSDAY NIGHT WITH FLAT FLOW TO
FOLLOW. HOWEVER...OVER THE SOUTHWEST PARTS OF THE NATION A LARGE
CLOSED LOW IN THE SOUTHERN STREAM IS NOW DEPICTED...PARTICULARLY BY
THE LATEST ECMWF...OPENING UP AND SPILLING ITS ENERGY EAST INTO THE
FLOW RIDING OVER THE TENNESSEE VALLEY. THE MODELS NOW 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. IN GENERAL...A BLEND
OF THE MODELS WAS PREFERRED THROUGH THE BULK OF THE FORECAST WITH
SOME ADJUSTMENT TOWARD THE PREVIOUS FORECAST FOR NEXT WEEKEND GIVEN
THE CONSISTENCY CONCERNS.
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 INTO FRIDAY MORNING. ONLY A BRIEF WINDOW FOR DRYING CAN BE
EXPECTED FROM FRIDAY NIGHT INTO SATURDAY MORNING 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
SUNDAY MORNING WITH SNOW CHANCES CONTINUING...MAINLY IN THE SOUTHERN
PARTS OF THE CWA. THIS SETUP WILL NEED TO BE WATCHED CLOSELY...
THOUGH...AS THE POTENTIAL EXISTS FOR THE COLD AIR TO SETTLE INTO THE
STATE BY LATE IN THE WEEKEND AND A LOW TO FORM IN THE NORTHERN GULF
SLIDING NORTHEAST WHILE SENDING AMPLE MOISTURE NORTH INTO OUR AREA
ON THE COLD SIDE OF THIS ARCTIC BOUNDARY. FOR NOW...HAVE GONE WITH
JUST SMALL CHANCES FOR SNOW FROM SATURDAY AFTERNOON THROUGH SUNDAY...
BUT THAT WILL SURELY NEED TO BE ADJUSTED ONE WAY OR ANOTHER AS THE
MODELS GET A BETTER HANDLE ON THIS SITUATION IN FUTURE RUNS.
THE CR GRID LOAD MADE FOR AN OKAY START TO THE EXTENDED FORECAST
GRIDS WITH CHANGES MADE PRIMARILY TO BETTER REFLECT THE LATEST ECMWF
SOLUTION FOR THE UPCOMING WEEKEND. ALSO...MADE SOME TYPICAL RIDGE
AND VALLEY TEMPERATURE ADJUSTMENTS FOR LOWS EACH NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 632 AM EST MON JAN 26 2015
MOST SITES HAVE COME DOWN THIS MORNING TO IFR AND LIFR CONDITIONS. A
FEW SITES ARE SEEING LOWER VIS DUE TO FOG AND/OR SHOWER ACTIVITY MOVING
ACROSS THOSE SITES. COLDER AIR IS SLOWING MOVING INTO THE REGION THIS
MORNING AND WILL TRANSITION RAIN SHOWERS TO SNOW SHOWERS AS WE GO
THROUGH THE MORNING. OTHERWISE A FEW SITES ARE SEEING GUSTY WINDS
AROUND 15 TO 20 KTS AS WINDS BEGIN SWITCHING WEST TO NORTHWEST
THROUGH THE DAY AS LOW CONTINUES TO EXIT TO THE EAST. OTHERWISE SITES
ARE EXPECTED TO IMPROVE LATER THIS AFTERNOON AS DRIER AIR CONTINUES
TO FILTER INTO EASTERN KY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...DJ
LONG TERM...GREIF
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
633 AM EST MON JAN 26 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 342 AM EST MON JAN 26 2015
WSR-88D THIS MORNING HAS CONTINUED TO SHOW AREAS OF RAIN SHOWERS
MOVING ACROSS EASTERN KY THIS MORNING. BEST COVERAGE HAS GENERALLY
BEEN ACROSS THE FAR SOUTHERN PORTIONS OF THE REGION THIS MORNING.
HOWEVER THIS MORNING WE HAVE SEEN GENERALLY LOWER AMTS OF PRECIP AND
TEMPS ARE STILL ABOVE FREEZING AT MOST LOCATIONS BESIDE BLACK MTN AT
8Z. GIVEN THIS HAVE LESSEN POPS AND ALSO LESSENED QPF AMTS ACROSS THE
REGION. THIS MAY STILL BE TOO OPTIMISTIC AS RETURNS FROM RADAR HAVE
BEEN QUITE LOW ACROSS CENTRAL AND WESTERN KY THIS MORNING. THIS TREND
OF LOWERING REFLECTIVITIES IS ALSO BACK UP BY THE HRRR WHICH ALSO
INITIALIZED FAIRLY WELL AT 7Z. OTHERWISE LEFT OVER SHOWERS WILL SLOWLY
TRANSITION TO SNOW SHOWERS THROUGH THE DAY WITH BEST COVERAGE ACROSS
THE FAR EAST THIS AFTERNOON.
THIS SURFACE LOW AND UPPER LEVEL TROUGH WILL CONTINUE EXIT EAST WHERE
IT DEVELOPS INTO A STRONG NOREASTER ALONG THE ATLANTIC SEABOARD LATER
TODAY. ACROSS EASTERN KY WE WILL CONTINUE TO TRANSITION TO GENERALLY
WEST TO NW FLOW. MODELS DO SHOW A FETCH OF MOISTURE DROPPING SOUTH
FROM THE GREAT LAKES TONIGHT INTO TUESDAY. RIGHT NOW HAVE MOVED
TOWARD SLIGHT CHANCES OF SNOW SHOWERS MAINLY ACROSS SW PORTION OF THE
CWA WHERE BETTER PLACEMENT OF MOISTURE AXIS EXISTS. EVEN SO GENERALLY
MOSTLY CLOUDY CONDITIONS WILL PREVAIL FOR MUCH OF THE PERIOD AREA
WIDE COUPLED WITH GENERALLY BELOW NORMAL TEMPS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 445 AM EST MON JAN 26 2015
THE MODELS ARE IN GOOD AGREEMENT ALOFT FOR THE FIRST PART OF THE
EXTENDED AND ARE IN FAIR AGREEMENT WITH THE LATTER PART. THE RUB HERE
IS THAT THE CONSISTENCY HAS BEEN TAKING HITS LATELY WITH THE FORECAST
FOR NEXT WEEKEND. A ONCE DISCARDED SOLUTION...MAINLY SEEN EARLIER IN
THE GFS...HAS RETURNED WITH SOME LIMITED SUPPORT FROM THE ECMWF.
EARLY ON...THE FOCUS WILL BE ON A DEEP CYCLONE OFF THE EASTERN
SEABOARD WHILE A FAST FLOW OF ENERGY ROILS ABOVE EAST KENTUCKY ON A
GENERALLY NORTHWEST TO SOUTHEAST PATH INTO WEDNESDAY MORNING. THIS
VORT STREAM IS SHUNTED EAST BY MIDDAY WEDNESDAY AS HIGHER HEIGHTS
FROM A WEAKENING SOUTHERN RIDGE MOVES INTO THE MID MISSISSIPPI
VALLEY AND THEN OVER THE LOWER OHIO BASIN. AT THE SAME TIME...A
DEVELOPING TROUGH WILL DIP INTO THE CENTRAL PLAINS AND SLIDE EAST.
THIS FEATURE RAMPS UP INTO THE DAY THURSDAY WITH THE GFS PROVIDING
BETTER SUPPORT FOR THE MORE ROBUST SOLUTION OF THE ECMWF. THIS
TROUGH CROSSES EAST KENTUCKY LATER THURSDAY NIGHT WITH FLAT FLOW TO
FOLLOW. HOWEVER...OVER THE SOUTHWEST PARTS OF THE NATION A LARGE
CLOSED LOW IN THE SOUTHERN STREAM IS NOW DEPICTED...PARTICULARLY BY
THE LATEST ECMWF...OPENING UP AND SPILLING ITS ENERGY EAST INTO THE
FLOW RIDING OVER THE TENNESSEE VALLEY. THE MODELS NOW 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. IN GENERAL...A BLEND
OF THE MODELS WAS PREFERRED THROUGH THE BULK OF THE FORECAST WITH
SOME ADJUSTMENT TOWARD THE PREVIOUS FORECAST FOR NEXT WEEKEND GIVEN
THE CONSISTENCY CONCERNS.
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 INTO FRIDAY MORNING. ONLY A BRIEF WINDOW FOR DRYING CAN BE
EXPECTED FROM FRIDAY NIGHT INTO SATURDAY MORNING 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
SUNDAY MORNING WITH SNOW CHANCES CONTINUING...MAINLY IN THE SOUTHERN
PARTS OF THE CWA. THIS SETUP WILL NEED TO BE WATCHED CLOSELY...
THOUGH...AS THE POTENTIAL EXISTS FOR THE COLD AIR TO SETTLE INTO THE
STATE BY LATE IN THE WEEKEND AND A LOW TO FORM IN THE NORTHERN GULF
SLIDING NORTHEAST WHILE SENDING AMPLE MOISTURE NORTH INTO OUR AREA
ON THE COLD SIDE OF THIS ARCTIC BOUNDARY. FOR NOW...HAVE GONE WITH
JUST SMALL CHANCES FOR SNOW FROM SATURDAY AFTERNOON THROUGH SUNDAY...
BUT THAT WILL SURELY NEED TO BE ADJUSTED ONE WAY OR ANOTHER AS THE
MODELS GET A BETTER HANDLE ON THIS SITUATION IN FUTURE RUNS.
THE CR GRID LOAD MADE FOR AN OKAY START TO THE EXTENDED FORECAST
GRIDS WITH CHANGES MADE PRIMARILY TO BETTER REFLECT THE LATEST ECMWF
SOLUTION FOR THE UPCOMING WEEKEND. ALSO...MADE SOME TYPICAL RIDGE
AND VALLEY TEMPERATURE ADJUSTMENTS FOR LOWS EACH NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 632 AM EST MON JAN 26 2015
MOST SITES HAVE COME DOWN THIS MORNING TO IFR AND LIFR CONDITIONS. A
FEW SITES ARE SEEING LOWER VIS DUE TO FOG AND/OR SHOWER ACTIVITY MOVING
ACROSS THOSE SITES. COLDER AIR IS SLOWING MOVING INTO THE REGION THIS
MORNING AND WILL TRANSITION RAIN SHOWERS TO SNOW SHOWERS AS WE GO
THROUGH THE MORNING. OTHERWISE A FEW SITES ARE SEEING GUSTY WINDS
AROUND 15 TO 20 KTS AS WINDS BEGIN SWITCHING WEST TO NORTHWEST
THROUGH THE DAY AS LOW CONTINUES TO EXIT TO THE EAST. OTHERWISE SITES
ARE EXPECTED TO IMPROVE LATER THIS AFTERNOON AS DRIER AIR CONTINUES
TO FILTER INTO EASTERN KY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DJ
LONG TERM...GREIF
AVIATION...DJ
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
445 AM EST MON JAN 26 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 342 AM EST MON JAN 26 2015
WSR-88D THIS MORNING HAS CONTINUED TO SHOW AREAS OF RAIN SHOWERS
MOVING ACROSS EASTERN KY THIS MORNING. BEST COVERAGE HAS GENERALLY
BEEN ACROSS THE FAR SOUTHERN PORTIONS OF THE REGION THIS MORNING.
HOWEVER THIS MORNING WE HAVE SEEN GENERALLY LOWER AMTS OF PRECIP AND
TEMPS ARE STILL ABOVE FREEZING AT MOST LOCATIONS BESIDE BLACK MTN AT
8Z. GIVEN THIS HAVE LESSEN POPS AND ALSO LESSENED QPF AMTS ACROSS THE
REGION. THIS MAY STILL BE TOO OPTIMISTIC AS RETURNS FROM RADAR HAVE
BEEN QUITE LOW ACROSS CENTRAL AND WESTERN KY THIS MORNING. THIS TREND
OF LOWERING REFLECTIVITIES IS ALSO BACK UP BY THE HRRR WHICH ALSO
INITIALIZED FAIRLY WELL AT 7Z. OTHERWISE LEFT OVER SHOWERS WILL SLOWLY
TRANSITION TO SNOW SHOWERS THROUGH THE DAY WITH BEST COVERAGE ACROSS
THE FAR EAST THIS AFTERNOON.
THIS SURFACE LOW AND UPPER LEVEL TROUGH WILL CONTINUE EXIT EAST WHERE
IT DEVELOPS INTO A STRONG NOREASTER ALONG THE ATLANTIC SEABOARD LATER
TODAY. ACROSS EASTERN KY WE WILL CONTINUE TO TRANSITION TO GENERALLY
WEST TO NW FLOW. MODELS DO SHOW A FETCH OF MOISTURE DROPPING SOUTH
FROM THE GREAT LAKES TONIGHT INTO TUESDAY. RIGHT NOW HAVE MOVED
TOWARD SLIGHT CHANCES OF SNOW SHOWERS MAINLY ACROSS SW PORTION OF THE
CWA WHERE BETTER PLACEMENT OF MOISTURE AXIS EXISTS. EVEN SO GENERALLY
MOSTLY CLOUDY CONDITIONS WILL PREVAIL FOR MUCH OF THE PERIOD AREA
WIDE COUPLED WITH GENERALLY BELOW NORMAL TEMPS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 445 AM EST MON JAN 26 2015
THE MODELS ARE IN GOOD AGREEMENT ALOFT FOR THE FIRST PART OF THE
EXTENDED AND ARE IN FAIR AGREEMENT WITH THE LATTER PART. THE RUB HERE
IS THAT THE CONSISTENCY HAS BEEN TAKING HITS LATELY WITH THE FORECAST
FOR NEXT WEEKEND. A ONCE DISCARDED SOLUTION...MAINLY SEEN EARLIER IN
THE GFS...HAS RETURNED WITH SOME LIMITED SUPPORT FROM THE ECMWF.
EARLY ON...THE FOCUS WILL BE ON A DEEP CYCLONE OFF THE EASTERN
SEABOARD WHILE A FAST FLOW OF ENERGY ROILS ABOVE EAST KENTUCKY ON A
GENERALLY NORTHWEST TO SOUTHEAST PATH INTO WEDNESDAY MORNING. THIS
VORT STREAM IS SHUNTED EAST BY MIDDAY WEDNESDAY AS HIGHER HEIGHTS
FROM A WEAKENING SOUTHERN RIDGE MOVES INTO THE MID MISSISSIPPI
VALLEY AND THEN OVER THE LOWER OHIO BASIN. AT THE SAME TIME...A
DEVELOPING TROUGH WILL DIP INTO THE CENTRAL PLAINS AND SLIDE EAST.
THIS FEATURE RAMPS UP INTO THE DAY THURSDAY WITH THE GFS PROVIDING
BETTER SUPPORT FOR THE MORE ROBUST SOLUTION OF THE ECMWF. THIS
TROUGH CROSSES EAST KENTUCKY LATER THURSDAY NIGHT WITH FLAT FLOW TO
FOLLOW. HOWEVER...OVER THE SOUTHWEST PARTS OF THE NATION A LARGE
CLOSED LOW IN THE SOUTHERN STREAM IS NOW DEPICTED...PARTICULARLY BY
THE LATEST ECMWF...OPENING UP AND SPILLING ITS ENERGY EAST INTO THE
FLOW RIDING OVER THE TENNESSEE VALLEY. THE MODELS NOW 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. IN GENERAL...A BLEND
OF THE MODELS WAS PREFERRED THROUGH THE BULK OF THE FORECAST WITH
SOME ADJUSTMENT TOWARD THE PREVIOUS FORECAST FOR NEXT WEEKEND GIVEN
THE CONSISTENCY CONCERNS.
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 INTO FRIDAY MORNING. ONLY A BRIEF WINDOW FOR DRYING CAN BE
EXPECTED FROM FRIDAY NIGHT INTO SATURDAY MORNING 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
SUNDAY MORNING WITH SNOW CHANCES CONTINUING...MAINLY IN THE SOUTHERN
PARTS OF THE CWA. THIS SETUP WILL NEED TO BE WATCHED CLOSELY...
THOUGH...AS THE POTENTIAL EXISTS FOR THE COLD AIR TO SETTLE INTO THE
STATE BY LATE IN THE WEEKEND AND A LOW TO FORM IN THE NORTHERN GULF
SLIDING NORTHEAST WHILE SENDING AMPLE MOISTURE NORTH INTO OUR AREA
ON THE COLD SIDE OF THIS ARCTIC BOUNDARY. FOR NOW...HAVE GONE WITH
JUST SMALL CHANCES FOR SNOW FROM SATURDAY AFTERNOON THROUGH SUNDAY...
BUT THAT WILL SURELY NEED TO BE ADJUSTED ONE WAY OR ANOTHER AS THE
MODELS GET A BETTER HANDLE ON THIS SITUATION IN FUTURE RUNS.
THE CR GRID LOAD MADE FOR AN OKAY START TO THE EXTENDED FORECAST
GRIDS WITH CHANGES MADE PRIMARILY TO BETTER REFLECT THE LATEST ECMWF
SOLUTION FOR THE UPCOMING WEEKEND. ALSO...MADE SOME TYPICAL RIDGE
AND VALLEY TEMPERATURE ADJUSTMENTS FOR LOWS EACH NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1253 AM EST MON JAN 26 2015
TONIGHT WILL BE TRICKY IN TERMS OF CIGS AS SITES HAVE BEEN AROUND OR
MVFR CEILINGS THUS FAR TONIGHT. THE QUESTION THEN BECOMES HOW QUICKLY
TO WE SEE IFR CONDITIONS OVERNIGHT AND MORNING HOURS. RIGHT NOW HAVE
SITES GOING IFR BY 10 TO 11 Z BEFORE SITES IMPROVE TO MVFR THIS
AFTERNOON. THE LOW PRESSURE THAT HAS BEEN POISED TO MOVE ACROSS THE
REGION IS TRACKING OVER EASTERN KY THIS HOUR AND WILL CONTINUE TO
MOVE EAST TONIGHT. THIS WILL CONTINUE TO BRING PERIODS OF RAIN AND
EVENTUALLY A CHANGEOVER TO SNOW AS WE MOVE INTO THE EARLY MORNING
HOURS. THIS WILL THEN TRANSITION TO MORE SNOW SHOWER ACTIVITY AS WE
MOVE INTO THE AFTERNOON. THIS LOW PRESSURE WILL ALSO USHER IN
STRONGER NW FLOW LATER TONIGHT INTO TOMORROW WITH GUSTY WINDS AROUND
20 KNOTS POSSIBLE OVERNIGHT INTO THE DAY TODAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DJ
LONG TERM...GREIF
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
343 AM EST MON JAN 26 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 342 AM EST MON JAN 26 2015
WSR-88D THIS MORNING HAS CONTINUED TO SHOW AREAS OF RAIN SHOWERS
MOVING ACROSS EASTERN KY THIS MORNING. BEST COVERAGE HAS GENERALLY
BEEN ACROSS THE FAR SOUTHERN PORTIONS OF THE REGION THIS MORNING.
HOWEVER THIS MORNING WE HAVE SEEN GENERALLY LOWER AMTS OF PRECIP AND
TEMPS ARE STILL ABOVE FREEZING AT MOST LOCATIONS BESIDE BLACK MTN AT
8Z. GIVEN THIS HAVE LESSEN POPS AND ALSO LESSENED QPF AMTS ACROSS THE
REGION. THIS MAY STILL BE TOO OPTIMISTIC AS RETURNS FROM RADAR HAVE
BEEN QUITE LOW ACROSS CENTRAL AND WESTERN KY THIS MORNING. THIS TREND
OF LOWERING REFLECTIVITIES IS ALSO BACK UP BY THE HRRR WHICH ALSO
INITIALIZED FAIRLY WELL AT 7Z. OTHERWISE LEFT OVER SHOWERS WILL SLOWLY
TRANSITION TO SNOW SHOWERS THROUGH THE DAY WITH BEST COVERAGE ACROSS
THE FAR EAST THIS AFTERNOON.
THIS SURFACE LOW AND UPPER LEVEL TROUGH WILL CONTINUE EXIT EAST WHERE
IT DEVELOPS INTO A STRONG NOREASTER ALONG THE ATLANTIC SEABOARD LATER
TODAY. ACROSS EASTERN KY WE WILL CONTINUE TO TRANSITION TO GENERALLY
WEST TO NW FLOW. MODELS DO SHOW A FETCH OF MOISTURE DROPPING SOUTH
FROM THE GREAT LAKES TONIGHT INTO TUESDAY. RIGHT NOW HAVE MOVED
TOWARD SLIGHT CHANCES OF SNOW SHOWERS MAINLY ACROSS SW PORTION OF THE
CWA WHERE BETTER PLACEMENT OF MOISTURE AXIS EXISTS. EVEN SO GENERALLY
MOSTLY CLOUDY CONDITIONS WILL PREVAIL FOR MUCH OF THE PERIOD AREA
WIDE COUPLED WITH GENERALLY BELOW NORMAL TEMPS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 420 PM EST SUN JAN 25 2015
A RATHER AMPLIFIED PATTERN IS EXPECTED TO BEGIN THE PERIOD. MODELS
REMAIN IN GENERALLY IN GOOD AGREEMENT FOR MOST OF THE PERIOD...WITH
DIFFERENCES INCREASING TOWARD THE END OF THE PERIOD. AT THE START OF
THE PERIOD A TROUGH IS EXPECTED TO BE IN PLACE FROM THE GREAT LAKES
SOUTH INTO THE MID ATLANTIC SATES AND OFF THE SOUTHEASTERN US
COAST...WITH A RIDGE OF HIGH PRESSURE FROM MEXICO NORTH INTO THE
SOUTHERN PLAINS AND ROCKIES. AT THE SFC THE A DEEP SFC LOW/BLIZZARD
WILL BE MOVING ALONG THE NORTHEAST US COAST TO START THE PERIOD WITH
A RIDGE OF HIGH PRESSURE AT THE SFC EXTENDING FROM ONTARIO INTO THE
GREAT LAKES AND MS VALLEY REGION. A SERIES OF SHORTWAVES IN NW FLOW
BETWEEN THE TWO WILL DROP FROM THE GREAT LAKES AND THROUGH THE OH
VALLEY AND APPALACHIANS TUESDAY INTO TUESDAY NIGHT. THIS WILL BRING
CHANCES FOR SNOW SHOWERS AND REINFORCE A COLD AIRMASS WITH 850 MB
TEMPS TO FALL TO THE -8C TO -10C RANGE BY LATE TUE AFTERNOON AND TUE
EVENING.
AS THE TROUGH AXIS LIFTS TO THE NORTH AND EAST AND THE SFC LOW MOVES
FURTHER UP THE EASTERN SEABOARD...HIGH PRESSURE WILL GRADUALLY BUILD
INTO THE LOWER OH VALLEY REGION AND APPALACHIANS TUE NIGHT INTO WED.
THE INFLUENCE OF THE RIDGING WILL WANE BY LATE WED NIGHT AS A
SHORTWAVE MOVING AROUND THE RIDGE OVER THE ROCKIES AND A NORTHERN
STREAM TROUGH BEGIN TO JOIN FORCES AND APPROACH THE GREAT LAKES AND
MS VALLEY REGION AS WELL AS THE LOWER OH VALLEY REGION. THE
ASSOCIATED SFC LOW SHOULD TRACK WELL NORTH OF THE AREA JUST TO THE
SOUTH OF THE SOUTHERN GREAT LAKES AND INTO THE MID ATLANTIC STATES
FROM WED NIGHT INTO THU NIGHT. THIS SYSTEM WILL HAVE SOMEWHAT
LIMITED MOISTURE...AND THIS SHOULD BE ANOTHER EVENT WHERE THE
ATMOSPHERE MOISTENS FROM THE TOP DOWN. AT THE ONSET...SOME SNOW
COULD MIX IN PENDING THE STRENGTH OF WARM AIR ADVECTION AND MOISTURE
ADVECTION LATE WED NIGHT INTO THU MORNING. THE CLOUDS ALSO MAY NOT
THICKEN QUICK ENOUGH TO PREVENT AT LEAST A MINOR RIDGE/VALLEY SPLIT
FOR THE VALLEYS ON WED EVENING. AT THIS POINT...A LOW IN THE MID TO
UPPER 20S OCCURRING AROUND 6Z ON THU IS EXPECTED.
COLDER AIR WILL WRAP BACK INTO THE REGION BEHIND THIS SYSTEM AND
POSSIBLY CHANGE ANY PRECIP BACK TO SNOW AS IT DEPARTS. HIGH PRESSURE
SHOULD THEN BUILD IN TO BRING A DRY START TO THE WEEKEND. THE ECMWF
LOWERS HEIGHTS MORE SIGNIFICANTLY ACROSS THE REGION AS WELL AS THE
GREAT LAKES AND EASTERN SEABOARD AT THE END OF THE PERIOD AND IS
THUS MUCH COLDER WITH THE AIRMASS. ANY SHORTWAVES AT THE END OF THE
PERIOD SHOULD BE RATHER MOISTURE STARVED WITH THE MODEL CONSENSUS
FAVORING ANYTHING THAT FALLS BEING SNOW. FOR TEMPS LATE IN THE
PERIOD...OPTED TO GO A TAD COLDER THAN THE CONSENSUS BLEND...MORE IN
LINE WITH ISC CONSENSUS AND GIVING A BIT MORE CREDIT TO THE PAST 2
ECMWF RUNS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1253 AM EST MON JAN 26 2015
TONIGHT WILL BE TRICKY IN TERMS OF CIGS AS SITES HAVE BEEN AROUND OR
MVFR CEILINGS THUS FAR TONIGHT. THE QUESTION THEN BECOMES HOW QUICKLY
TO WE SEE IFR CONDITIONS OVERNIGHT AND MORNING HOURS. RIGHT NOW HAVE
SITES GOING IFR BY 10 TO 11 Z BEFORE SITES IMPROVE TO MVFR THIS
AFTERNOON. THE LOW PRESSURE THAT HAS BEEN POISED TO MOVE ACROSS THE
REGION IS TRACKING OVER EASTERN KY THIS HOUR AND WILL CONTINUE TO
MOVE EAST TONIGHT. THIS WILL CONTINUE TO BRING PERIODS OF RAIN AND
EVENTUALLY A CHANGEOVER TO SNOW AS WE MOVE INTO THE EARLY MORNING
HOURS. THIS WILL THEN TRANSITION TO MORE SNOW SHOWER ACTIVITY AS WE
MOVE INTO THE AFTERNOON. THIS LOW PRESSURE WILL ALSO USHER IN
STRONGER NW FLOW LATER TONIGHT INTO TOMORROW WITH GUSTY WINDS AROUND
20 KNOTS POSSIBLE OVERNIGHT INTO THE DAY TODAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DJ
LONG TERM...JP
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
144 AM EST MON JAN 26 2015
.UPDATE...
ISSUED AT 143 AM EST MON JAN 26 2015
DID A QUICK UPDATE TO FRESHEN GRIDS WITH OBS AND TRENDS. RIGHT NOW
LOW PRESSURE CONTINUES TO TRACK ACROSS THE REGION THIS EVENING AND
MOST OF THIS IS IN THE FORM OF RAIN WITH MOST SITES BESIDES BLACK MT
IN THE UPPER 30S TO LOWER 40S THIS HOUR. BEST COVERAGE OF RAIN THIS
HOUR IS ACROSS THE SOUTHERN PORTION OF THE CWA WITH MORE SCATTERED
ACTIVITY AS YOU MOVE NORTH. TEMPERATURES ARE DROPPING ACROSS FAR
WESTERN KY TONIGHT AND THIS IS EXPECTED TO BE THE TREND FROM NW TO SE
ACROSS THE STATE OVERNIGHT TONIGHT. WSR-88D RADAR HOWEVER IS NOT
SHOWING MUCH IN THE WAY OF RETURNS TO OUR WEST WITH GENERALLY LIGHT
BAND OF PRECIP ACROSS WEST AND CENTRAL KY THIS HOUR. THAT SAID
COMBINE THIS WITH HRRR THAT SHOWS A GENERAL WEAKENING TREND OF THE
PRECIP AS WE MOVE INTO THE MORNING WOULD SUGGEST LIGHTER AMTS AS WE
SWITCH TO SNOW IN THE DAWN HOUR. RIGHT NOW WILL ONLY MAKE MINOR
CHANGES AND CONTINUE TO MONITOR RADAR AND TRENDS.
UPDATE ISSUED AT 1137 PM EST SUN JAN 25 2015
GIVEN THE WELL ABOVE NORMAL TEMPERATURES EXPERIENCED TODAY /SOME
LOCATIONS IN THE 50S/...WE JUST REALLY HAVEN/T SEEN A LARGE COOL DOWN
ACROSS MUCH OF EASTERN KY THROUGH MOST OF THE EVENING. THIS IS
ESPECIALLY TRUE IN AREAS THAT HAVE NOT YET RECEIVED RAIN...OR HAVE
ONLY RECEIVED A SMALL AMOUNT. THIS BEING SAID...OTHER THAN ELEVATIONS
ABOVE 3000 FT...DON/T EXPECT RAIN TO START CHANGING OVER QUITE AS FAST
AS WHAT WAS IN THE PREVIOUS FORECAST. WORKED TO ADJUST THE LOW
TEMPERATURE FOR OVERNIGHT...BASED ON THE LATEST MODEL GUIDANCE AND
SOUNDINGS...AS WELL AS BASED ON THE ONGOING CONDITIONS WITH
TEMPERATURES AND COOLING DOWNSTREAM...PREVIOUS SNOW PACK...ETC.
WENT WITH A BLEND OF THE CURRENT FORECAST...THE LATEST HRRR /WHICH
SEEMS TO HAVE THE BEST INITIALIZATION FOR THIS SYSTEM/...AND A LITTLE
INFLUENCE FROM THE GFS...WHICH TRENDED CLOSER TO OVERALL THINKING FOR
THE LOW. THEN...ADJUSTED INDIVIDUAL LOCATIONS TO GET THEM WITHIN
BETTER TOLERANCE...INCLUDING BUMPING UP BLACK MOUNTAIN TO 29 DEGREES
AND OTHER TERRAIN ABOVE 2500 FEET TO BETWEEN 30 AND 32 DEGREES.
FURTHER MORE...GIVEN THE SLOW PROGRESS OF TEMPERATURES FALLING...WENT
AHEAD AND PUSHED BACK THE TIMING OF THE LOW TEMPERATURE TO 13Z
MONDAY. FROM HERE...USED A MIXTURE OF THE CONS-SHORT AND HAND EDITING
TO ADJUST THE DIURNAL CURVE FOR THE REMAINDER OF THE NIGHT.
ALL THINGS CONSIDERED...THE SLIGHT UPTICK IN TEMPERATURE FORECAST
WILL RESULT IN A SEVERAL HOUR DIFFERENCE IN THE RAIN CHANGING OVER TO
SNOW. THIS WILL KEEP ANY SNOW ACCUMULATIONS OUT OF THE FORECAST
THROUGH 12Z /WITH THE EXCEPTION OF BLACK MOUNTAIN/...AND LESS SNOW
ACCUMULATION IN FOR DURING THE DAY TOMORROW. BLACK MOUNTAIN IS
CURRENTLY AT 32 DEGREES...SO THEY MAY START TO MIX WITH SNOW AT ANY
TIME. HOWEVER...MOST OF THE REST OF THE AREA WILL LIKELY NOT SEE
SNOW MIXING IN UNTIL NEAR DAWN...THEN SLOWLY TRANSITION TO ALL SNOW
BETWEEN NOON AND 3PM. BY THIS POINT...MODEL SOUNDINGS ARE SHOWING A
STRONG AMOUNT OF DRY AIR CUTTING OFF SOME OF THE BEST ACCUMULATION
POTENTIAL DURING THE AFTERNOON. OVERALL...SNOW TOTALS WERE LOWERED
ACROSS THE CWA. EXPECT ELEVATIONS ABOVE 3000 FEET TO PICK UP THE
HIGHEST AMOUNTS...BETWEEN 1 AND 2 INCHES. SOME OF THE OTHER RIDGES
ACROSS THE AREA COULD SEE BETWEEN A HALF AN ONE INCH...BUT A MAJORITY
OF THE CWA WILL ONLY PICK UP A HALF INCH OR LESS. MOST OF THIS IS
STILL EXPECTED TO FALL BETWEEN 12 AND 18Z WHEN THE BEST LIFT AND
MOISTURE AND TEMPERATURES COMBINE...AND SURFACE TEMPERATURES FINALLY
FALL ENOUGH TO ALLOW FOR ACCUMULATING SNOW.
UPDATE ISSUED AT 706 PM EST SUN JAN 25 2015
FRESHENED UP THE GRIDS WITH THE LATEST OBSERVATIONAL DATA FOR
TEMPS...DEW POINTS...AND WINDS. THIS RESULTED IN LITTLE OVERALL
CHANGE FROM THE ONGOING FORECAST. BASED ON THE CURRENT RADAR
RETURNS...AND THE PWAT VALUES OVERNIGHT BEING AROUND A HALF INCH OR
LESS...WENT AHEAD AND REDUCED ANY MENTION OF MODERATE
RAINFALL/SNOWFALL TO LIGHT. JUST NOT SEEING A WHOLE LOT OF EVIDENCE
AT THIS POINT FOR MODERATE TO HEAVY INTENSITIES...THOUGH SNOW COULD
HAVE SOME HEAVIER SPOTS AT TIMES TOMORROW MORNING. LATEST NAM12
FORECAST SOUNDINGS REALLY START TO LOSE MOISTURE IN THE UPPER LEVELS
BETWEEN 6 AND 9 Z...WITH NOT MUCH LIFT EITHER...ALSO SUPPORTING
LIGHTER INTENSITIES. OTHERWISE...FORECAST SEEMS TO BE IN PRETTY GOOD
SHAPE OVER THE NEXT FEW HOURS. THE CENTER OF THE LOW IS CURRENTLY
OVER SOUTH CENTRAL KY AND MOVING OUR DIRECTION...WITH THE NEXT ROUND
OF LIGHT RAIN ABOUT TO SPREAD ACROSS THE CWA OVER THE NEXT 1 TO 2
HOURS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 409 PM EST SUN JAN 25 2015
SURFACE ANALYSIS AS OF 20Z ACROSS THE REGION FEATURES A SMALL LOW
PRESSURE SYSTEM OVER THE LOWER MIDWEST TRACKING EAST INTO THE OH
VALLEY THIS EVENING. AHEAD OF THIS...SOME SHOWER ACTIVITY HAS BEGUN
TO MOVE INTO THE AREA THIS AFTERNOON WITH MORE WIDESPREAD PRECIP BACK
WEST INTO WESTERN KENTUCKY AND SOUTHERN INDIANA. PLENTY OF SOUTHWEST
FLOW TODAY AND WAA INTO THE AREA HAS ALLOWED FOR TEMPS TO RISE INTO
THE UPPER 40S AND EVEN LOWER 50S ACROSS EASTERN KENTUCKY TODAY.
MODELS SHOWING THE COLD FRONT TO MOVE THROUGH LATER TONIGHT AFTER 00Z
WILL HAVE THE COLDER AIR MOVING IN LATER. THIS ADVECTION WILL BEGIN
IN EARNEST JUST AFTER 06Z AS THE FRONT MOVES THROUGH. EXPECTING A
CHANGE OVER IN THE HIGHER ELEVATIONS WITH ALREADY TEMPS AT BLACK
MOUNTAIN REACHING ITS HIGH FOR THE DAY IN THE UPPER 30S AND IS NOW
BEGINNING TO DROP OFF AT THIS HOUR. MODEL PROFILES SHOW A BRIEF
PERIOD OF GOOD OMEGA THROUGH THE LAST FEW HOURS OF THE EVENT AS THE
FRONT MOVES THROUGH. WITH COLD ENOUGH AIR MOVING IN...THERE COULD BE
SOME QUICK BURSTS OF SNOW IN THE HIGHER ELEVATIONS AND EVEN IN THE
VALLEYS WHERE COLDER AIR HAS FINALLY MOVED IN. SPEAKING OF
TEMPERATURES...LATE TONIGHT AND INTO THE DAY ON MONDAY...TEMPS WILL
BE FALLING INTO THE MORNING HOURS BUT SOME SLIGHT RADIATIONAL HEATING
DURING THE DAY BEFORE THE CORE OF THE AIR MASS MOVES IN MONDAY
AFTERNOON AND INTO MONDAY NIGHT WILL RESULT IN TEMPS RISING A DEGREE
OR TWO OR HOLDING STEADY THROUGH THE DAY TOMORROW. TEMPS OVER THE
HIGHER TERRAIN SHOULD SLOWLY FALL THROUGH THE DAY.
WINDS AFTER FRONTAL PASSAGE MONDAY MORNING WILL THEN SWITCH AROUND TO
THE NORTHWEST FOR A FAVORABLE DIRECTION FOR SOME UPSLOPE SNOW SHOWERS
THROUGH MONDAY AFTERNOON. MOISTURE DEPTH HANGS AROUND THROUGH MONDAY
MORNING AND INTO THE AFTERNOON WITH SOME DECENT LIFT REMAINING
ACCORDING TO THE NAM AND GFS SO SOME DECENT SNOW SHOWERS WILL HANG
AROUND THROUGH THE DAY ON MONDAY BEFORE TAPERING OFF TO FLURRIES FROM
WEST TO EAST INTO MONDAY NIGHT. THE CORE OF THE AIR MASS MOVING IN
WILL CAUSE TEMPS TO PLUMMET INTO THE MID 20S MONDAY NIGHT AND WILL
LIKELY ADD TO THE THREAT OF HAZARDOUS AND SLICK ROADS.
THEREFORE...HAVE ISSUED AN SPS TO HIGHLIGHT THIS THREAT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 420 PM EST SUN JAN 25 2015
A RATHER AMPLIFIED PATTERN IS EXPECTED TO BEGIN THE PERIOD. MODELS
REMAIN IN GENERALLY IN GOOD AGREEMENT FOR MOST OF THE PERIOD...WITH
DIFFERENCES INCREASING TOWARD THE END OF THE PERIOD. AT THE START OF
THE PERIOD A TROUGH IS EXPECTED TO BE IN PLACE FROM THE GREAT LAKES
SOUTH INTO THE MID ATLANTIC SATES AND OFF THE SOUTHEASTERN US
COAST...WITH A RIDGE OF HIGH PRESSURE FROM MEXICO NORTH INTO THE
SOUTHERN PLAINS AND ROCKIES. AT THE SFC THE A DEEP SFC LOW/BLIZZARD
WILL BE MOVING ALONG THE NORTHEAST US COAST TO START THE PERIOD WITH
A RIDGE OF HIGH PRESSURE AT THE SFC EXTENDING FROM ONTARIO INTO THE
GREAT LAKES AND MS VALLEY REGION. A SERIES OF SHORTWAVES IN NW FLOW
BETWEEN THE TWO WILL DROP FROM THE GREAT LAKES AND THROUGH THE OH
VALLEY AND APPALACHIANS TUESDAY INTO TUESDAY NIGHT. THIS WILL BRING
CHANCES FOR SNOW SHOWERS AND REINFORCE A COLD AIRMASS WITH 850 MB
TEMPS TO FALL TO THE -8C TO -10C RANGE BY LATE TUE AFTERNOON AND TUE
EVENING.
AS THE TROUGH AXIS LIFTS TO THE NORTH AND EAST AND THE SFC LOW MOVES
FURTHER UP THE EASTERN SEABOARD...HIGH PRESSURE WILL GRADUALLY BUILD
INTO THE LOWER OH VALLEY REGION AND APPALACHIANS TUE NIGHT INTO WED.
THE INFLUENCE OF THE RIDGING WILL WANE BY LATE WED NIGHT AS A
SHORTWAVE MOVING AROUND THE RIDGE OVER THE ROCKIES AND A NORTHERN
STREAM TROUGH BEGIN TO JOIN FORCES AND APPROACH THE GREAT LAKES AND
MS VALLEY REGION AS WELL AS THE LOWER OH VALLEY REGION. THE
ASSOCIATED SFC LOW SHOULD TRACK WELL NORTH OF THE AREA JUST TO THE
SOUTH OF THE SOUTHERN GREAT LAKES AND INTO THE MID ATLANTIC STATES
FROM WED NIGHT INTO THU NIGHT. THIS SYSTEM WILL HAVE SOMEWHAT
LIMITED MOISTURE...AND THIS SHOULD BE ANOTHER EVENT WHERE THE
ATMOSPHERE MOISTENS FROM THE TOP DOWN. AT THE ONSET...SOME SNOW
COULD MIX IN PENDING THE STRENGTH OF WARM AIR ADVECTION AND MOISTURE
ADVECTION LATE WED NIGHT INTO THU MORNING. THE CLOUDS ALSO MAY NOT
THICKEN QUICK ENOUGH TO PREVENT AT LEAST A MINOR RIDGE/VALLEY SPLIT
FOR THE VALLEYS ON WED EVENING. AT THIS POINT...A LOW IN THE MID TO
UPPER 20S OCCURRING AROUND 6Z ON THU IS EXPECTED.
COLDER AIR WILL WRAP BACK INTO THE REGION BEHIND THIS SYSTEM AND
POSSIBLY CHANGE ANY PRECIP BACK TO SNOW AS IT DEPARTS. HIGH PRESSURE
SHOULD THEN BUILD IN TO BRING A DRY START TO THE WEEKEND. THE ECMWF
LOWERS HEIGHTS MORE SIGNIFICANTLY ACROSS THE REGION AS WELL AS THE
GREAT LAKES AND EASTERN SEABOARD AT THE END OF THE PERIOD AND IS
THUS MUCH COLDER WITH THE AIRMASS. ANY SHORTWAVES AT THE END OF THE
PERIOD SHOULD BE RATHER MOISTURE STARVED WITH THE MODEL CONSENSUS
FAVORING ANYTHING THAT FALLS BEING SNOW. FOR TEMPS LATE IN THE
PERIOD...OPTED TO GO A TAD COLDER THAN THE CONSENSUS BLEND...MORE IN
LINE WITH ISC CONSENSUS AND GIVING A BIT MORE CREDIT TO THE PAST 2
ECMWF RUNS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1253 AM EST MON JAN 26 2015
TONIGHT WILL BE TRICKY IN TERMS OF CIGS AS SITES HAVE BEEN AROUND OR
MVFR CEILINGS THUS FAR TONIGHT. THE QUESTION THEN BECOMES HOW QUICKLY
TO WE SEE IFR CONDITIONS OVERNIGHT AND MORNING HOURS. RIGHT NOW HAVE
SITES GOING IFR BY 10 TO 11 Z BEFORE SITES IMPROVE TO MVFR THIS
AFTERNOON. THE LOW PRESSURE THAT HAS BEEN POISED TO MOVE ACROSS THE
REGION IS TRACKING OVER EASTERN KY THIS HOUR AND WILL CONTINUE TO
MOVE EAST TONIGHT. THIS WILL CONTINUE TO BRING PERIODS OF RAIN AND
EVENTUALLY A CHANGEOVER TO SNOW AS WE MOVE INTO THE EARLY MORNING
HOURS. THIS WILL THEN TRANSITION TO MORE SNOW SHOWER ACTIVITY AS WE
MOVE INTO THE AFTERNOON. THIS LOW PRESSURE WILL ALSO USHER IN
STRONGER NW FLOW LATER TONIGHT INTO TOMORROW WITH GUSTY WINDS AROUND
20 KNOTS POSSIBLE OVERNIGHT INTO THE DAY TODAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...SHALLENBERGER
LONG TERM...JP
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
1254 AM EST MON JAN 26 2015
.UPDATE...
ISSUED AT 1137 PM EST SUN JAN 25 2015
GIVEN THE WELL ABOVE NORMAL TEMPERATURES EXPERIENCED TODAY /SOME
LOCATIONS IN THE 50S/...WE JUST REALLY HAVEN/T SEEN A LARGE COOL DOWN
ACROSS MUCH OF EASTERN KY THROUGH MOST OF THE EVENING. THIS IS
ESPECIALLY TRUE IN AREAS THAT HAVE NOT YET RECEIVED RAIN...OR HAVE
ONLY RECEIVED A SMALL AMOUNT. THIS BEING SAID...OTHER THAN ELEVATIONS
ABOVE 3000 FT...DON/T EXPECT RAIN TO START CHANGING OVER QUITE AS FAST
AS WHAT WAS IN THE PREVIOUS FORECAST. WORKED TO ADJUST THE LOW
TEMPERATURE FOR OVERNIGHT...BASED ON THE LATEST MODEL GUIDANCE AND
SOUNDINGS...AS WELL AS BASED ON THE ONGOING CONDITIONS WITH
TEMPERATURES AND COOLING DOWNSTREAM...PREVIOUS SNOW PACK...ETC.
WENT WITH A BLEND OF THE CURRENT FORECAST...THE LATEST HRRR /WHICH
SEEMS TO HAVE THE BEST INITIALIZATION FOR THIS SYSTEM/...AND A LITTLE
INFLUENCE FROM THE GFS...WHICH TRENDED CLOSER TO OVERALL THINKING FOR
THE LOW. THEN...ADJUSTED INDIVIDUAL LOCATIONS TO GET THEM WITHIN
BETTER TOLERANCE...INCLUDING BUMPING UP BLACK MOUNTAIN TO 29 DEGREES
AND OTHER TERRAIN ABOVE 2500 FEET TO BETWEEN 30 AND 32 DEGREES.
FURTHER MORE...GIVEN THE SLOW PROGRESS OF TEMPERATURES FALLING...WENT
AHEAD AND PUSHED BACK THE TIMING OF THE LOW TEMPERATURE TO 13Z
MONDAY. FROM HERE...USED A MIXTURE OF THE CONS-SHORT AND HAND EDITING
TO ADJUST THE DIURNAL CURVE FOR THE REMAINDER OF THE NIGHT.
ALL THINGS CONSIDERED...THE SLIGHT UPTICK IN TEMPERATURE FORECAST
WILL RESULT IN A SEVERAL HOUR DIFFERENCE IN THE RAIN CHANGING OVER TO
SNOW. THIS WILL KEEP ANY SNOW ACCUMULATIONS OUT OF THE FORECAST
THROUGH 12Z /WITH THE EXCEPTION OF BLACK MOUNTAIN/...AND LESS SNOW
ACCUMULATION IN FOR DURING THE DAY TOMORROW. BLACK MOUNTAIN IS
CURRENTLY AT 32 DEGREES...SO THEY MAY START TO MIX WITH SNOW AT ANY
TIME. HOWEVER...MOST OF THE REST OF THE AREA WILL LIKELY NOT SEE
SNOW MIXING IN UNTIL NEAR DAWN...THEN SLOWLY TRANSITION TO ALL SNOW
BETWEEN NOON AND 3PM. BY THIS POINT...MODEL SOUNDINGS ARE SHOWING A
STRONG AMOUNT OF DRY AIR CUTTING OFF SOME OF THE BEST ACCUMULATION
POTENTIAL DURING THE AFTERNOON. OVERALL...SNOW TOTALS WERE LOWERED
ACROSS THE CWA. EXPECT ELEVATIONS ABOVE 3000 FEET TO PICK UP THE
HIGHEST AMOUNTS...BETWEEN 1 AND 2 INCHES. SOME OF THE OTHER RIDGES
ACROSS THE AREA COULD SEE BETWEEN A HALF AN ONE INCH...BUT A MAJORITY
OF THE CWA WILL ONLY PICK UP A HALF INCH OR LESS. MOST OF THIS IS
STILL EXPECTED TO FALL BETWEEN 12 AND 18Z WHEN THE BEST LIFT AND
MOISTURE AND TEMPERATURES COMBINE...AND SURFACE TEMPERATURES FINALLY
FALL ENOUGH TO ALLOW FOR ACCUMULATING SNOW.
UPDATE ISSUED AT 706 PM EST SUN JAN 25 2015
FRESHENED UP THE GRIDS WITH THE LATEST OBSERVATIONAL DATA FOR
TEMPS...DEW POINTS...AND WINDS. THIS RESULTED IN LITTLE OVERALL
CHANGE FROM THE ONGOING FORECAST. BASED ON THE CURRENT RADAR
RETURNS...AND THE PWAT VALUES OVERNIGHT BEING AROUND A HALF INCH OR
LESS...WENT AHEAD AND REDUCED ANY MENTION OF MODERATE
RAINFALL/SNOWFALL TO LIGHT. JUST NOT SEEING A WHOLE LOT OF EVIDENCE
AT THIS POINT FOR MODERATE TO HEAVY INTENSITIES...THOUGH SNOW COULD
HAVE SOME HEAVIER SPOTS AT TIMES TOMORROW MORNING. LATEST NAM12
FORECAST SOUNDINGS REALLY START TO LOSE MOISTURE IN THE UPPER LEVELS
BETWEEN 6 AND 9 Z...WITH NOT MUCH LIFT EITHER...ALSO SUPPORTING
LIGHTER INTENSITIES. OTHERWISE...FORECAST SEEMS TO BE IN PRETTY GOOD
SHAPE OVER THE NEXT FEW HOURS. THE CENTER OF THE LOW IS CURRENTLY
OVER SOUTH CENTRAL KY AND MOVING OUR DIRECTION...WITH THE NEXT ROUND
OF LIGHT RAIN ABOUT TO SPREAD ACROSS THE CWA OVER THE NEXT 1 TO 2
HOURS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 409 PM EST SUN JAN 25 2015
SURFACE ANALYSIS AS OF 20Z ACROSS THE REGION FEATURES A SMALL LOW
PRESSURE SYSTEM OVER THE LOWER MIDWEST TRACKING EAST INTO THE OH
VALLEY THIS EVENING. AHEAD OF THIS...SOME SHOWER ACTIVITY HAS BEGUN
TO MOVE INTO THE AREA THIS AFTERNOON WITH MORE WIDESPREAD PRECIP BACK
WEST INTO WESTERN KENTUCKY AND SOUTHERN INDIANA. PLENTY OF SOUTHWEST
FLOW TODAY AND WAA INTO THE AREA HAS ALLOWED FOR TEMPS TO RISE INTO
THE UPPER 40S AND EVEN LOWER 50S ACROSS EASTERN KENTUCKY TODAY.
MODELS SHOWING THE COLD FRONT TO MOVE THROUGH LATER TONIGHT AFTER 00Z
WILL HAVE THE COLDER AIR MOVING IN LATER. THIS ADVECTION WILL BEGIN
IN EARNEST JUST AFTER 06Z AS THE FRONT MOVES THROUGH. EXPECTING A
CHANGE OVER IN THE HIGHER ELEVATIONS WITH ALREADY TEMPS AT BLACK
MOUNTAIN REACHING ITS HIGH FOR THE DAY IN THE UPPER 30S AND IS NOW
BEGINNING TO DROP OFF AT THIS HOUR. MODEL PROFILES SHOW A BRIEF
PERIOD OF GOOD OMEGA THROUGH THE LAST FEW HOURS OF THE EVENT AS THE
FRONT MOVES THROUGH. WITH COLD ENOUGH AIR MOVING IN...THERE COULD BE
SOME QUICK BURSTS OF SNOW IN THE HIGHER ELEVATIONS AND EVEN IN THE
VALLEYS WHERE COLDER AIR HAS FINALLY MOVED IN. SPEAKING OF
TEMPERATURES...LATE TONIGHT AND INTO THE DAY ON MONDAY...TEMPS WILL
BE FALLING INTO THE MORNING HOURS BUT SOME SLIGHT RADIATIONAL HEATING
DURING THE DAY BEFORE THE CORE OF THE AIR MASS MOVES IN MONDAY
AFTERNOON AND INTO MONDAY NIGHT WILL RESULT IN TEMPS RISING A DEGREE
OR TWO OR HOLDING STEADY THROUGH THE DAY TOMORROW. TEMPS OVER THE
HIGHER TERRAIN SHOULD SLOWLY FALL THROUGH THE DAY.
WINDS AFTER FRONTAL PASSAGE MONDAY MORNING WILL THEN SWITCH AROUND TO
THE NORTHWEST FOR A FAVORABLE DIRECTION FOR SOME UPSLOPE SNOW SHOWERS
THROUGH MONDAY AFTERNOON. MOISTURE DEPTH HANGS AROUND THROUGH MONDAY
MORNING AND INTO THE AFTERNOON WITH SOME DECENT LIFT REMAINING
ACCORDING TO THE NAM AND GFS SO SOME DECENT SNOW SHOWERS WILL HANG
AROUND THROUGH THE DAY ON MONDAY BEFORE TAPERING OFF TO FLURRIES FROM
WEST TO EAST INTO MONDAY NIGHT. THE CORE OF THE AIR MASS MOVING IN
WILL CAUSE TEMPS TO PLUMMET INTO THE MID 20S MONDAY NIGHT AND WILL
LIKELY ADD TO THE THREAT OF HAZARDOUS AND SLICK ROADS.
THEREFORE...HAVE ISSUED AN SPS TO HIGHLIGHT THIS THREAT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 420 PM EST SUN JAN 25 2015
A RATHER AMPLIFIED PATTERN IS EXPECTED TO BEGIN THE PERIOD. MODELS
REMAIN IN GENERALLY IN GOOD AGREEMENT FOR MOST OF THE PERIOD...WITH
DIFFERENCES INCREASING TOWARD THE END OF THE PERIOD. AT THE START OF
THE PERIOD A TROUGH IS EXPECTED TO BE IN PLACE FROM THE GREAT LAKES
SOUTH INTO THE MID ATLANTIC SATES AND OFF THE SOUTHEASTERN US
COAST...WITH A RIDGE OF HIGH PRESSURE FROM MEXICO NORTH INTO THE
SOUTHERN PLAINS AND ROCKIES. AT THE SFC THE A DEEP SFC LOW/BLIZZARD
WILL BE MOVING ALONG THE NORTHEAST US COAST TO START THE PERIOD WITH
A RIDGE OF HIGH PRESSURE AT THE SFC EXTENDING FROM ONTARIO INTO THE
GREAT LAKES AND MS VALLEY REGION. A SERIES OF SHORTWAVES IN NW FLOW
BETWEEN THE TWO WILL DROP FROM THE GREAT LAKES AND THROUGH THE OH
VALLEY AND APPALACHIANS TUESDAY INTO TUESDAY NIGHT. THIS WILL BRING
CHANCES FOR SNOW SHOWERS AND REINFORCE A COLD AIRMASS WITH 850 MB
TEMPS TO FALL TO THE -8C TO -10C RANGE BY LATE TUE AFTERNOON AND TUE
EVENING.
AS THE TROUGH AXIS LIFTS TO THE NORTH AND EAST AND THE SFC LOW MOVES
FURTHER UP THE EASTERN SEABOARD...HIGH PRESSURE WILL GRADUALLY BUILD
INTO THE LOWER OH VALLEY REGION AND APPALACHIANS TUE NIGHT INTO WED.
THE INFLUENCE OF THE RIDGING WILL WANE BY LATE WED NIGHT AS A
SHORTWAVE MOVING AROUND THE RIDGE OVER THE ROCKIES AND A NORTHERN
STREAM TROUGH BEGIN TO JOIN FORCES AND APPROACH THE GREAT LAKES AND
MS VALLEY REGION AS WELL AS THE LOWER OH VALLEY REGION. THE
ASSOCIATED SFC LOW SHOULD TRACK WELL NORTH OF THE AREA JUST TO THE
SOUTH OF THE SOUTHERN GREAT LAKES AND INTO THE MID ATLANTIC STATES
FROM WED NIGHT INTO THU NIGHT. THIS SYSTEM WILL HAVE SOMEWHAT
LIMITED MOISTURE...AND THIS SHOULD BE ANOTHER EVENT WHERE THE
ATMOSPHERE MOISTENS FROM THE TOP DOWN. AT THE ONSET...SOME SNOW
COULD MIX IN PENDING THE STRENGTH OF WARM AIR ADVECTION AND MOISTURE
ADVECTION LATE WED NIGHT INTO THU MORNING. THE CLOUDS ALSO MAY NOT
THICKEN QUICK ENOUGH TO PREVENT AT LEAST A MINOR RIDGE/VALLEY SPLIT
FOR THE VALLEYS ON WED EVENING. AT THIS POINT...A LOW IN THE MID TO
UPPER 20S OCCURRING AROUND 6Z ON THU IS EXPECTED.
COLDER AIR WILL WRAP BACK INTO THE REGION BEHIND THIS SYSTEM AND
POSSIBLY CHANGE ANY PRECIP BACK TO SNOW AS IT DEPARTS. HIGH PRESSURE
SHOULD THEN BUILD IN TO BRING A DRY START TO THE WEEKEND. THE ECMWF
LOWERS HEIGHTS MORE SIGNIFICANTLY ACROSS THE REGION AS WELL AS THE
GREAT LAKES AND EASTERN SEABOARD AT THE END OF THE PERIOD AND IS
THUS MUCH COLDER WITH THE AIRMASS. ANY SHORTWAVES AT THE END OF THE
PERIOD SHOULD BE RATHER MOISTURE STARVED WITH THE MODEL CONSENSUS
FAVORING ANYTHING THAT FALLS BEING SNOW. FOR TEMPS LATE IN THE
PERIOD...OPTED TO GO A TAD COLDER THAN THE CONSENSUS BLEND...MORE IN
LINE WITH ISC CONSENSUS AND GIVING A BIT MORE CREDIT TO THE PAST 2
ECMWF RUNS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1253 AM EST MON JAN 26 2015
TONIGHT WILL BE TRICKY IN TERMS OF CIGS AS SITES HAVE BEEN AROUND OR
MVFR CEILINGS THUS FAR TONIGHT. THE QUESTION THEN BECOMES HOW QUICKLY
TO WE SEE IFR CONDITIONS OVERNIGHT AND MORNING HOURS. RIGHT NOW HAVE
SITES GOING IFR BY 10 TO 11 Z BEFORE SITES IMPROVE TO MVFR THIS
AFTERNOON. THE LOW PRESSURE THAT HAS BEEN POISED TO MOVE ACROSS THE
REGION IS TRACKING OVER EASTERN KY THIS HOUR AND WILL CONTINUE TO
MOVE EAST TONIGHT. THIS WILL CONTINUE TO BRING PERIODS OF RAIN AND
EVENTUALLY A CHANGEOVER TO SNOW AS WE MOVE INTO THE EARLY MORNING
HOURS. THIS WILL THEN TRANSITION TO MORE SNOW SHOWER ACTIVITY AS WE
MOVE INTO THE AFTERNOON. THIS LOW PRESSURE WILL ALSO USHER IN
STRONGER NW FLOW LATER TONIGHT INTO TOMORROW WITH GUSTY WINDS AROUND
20 KNOTS POSSIBLE OVERNIGHT INTO THE DAY TODAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JMW
SHORT TERM...SHALLENBERGER
LONG TERM...JP
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1216 AM EST Mon Jan 26 2015
...Updated Aviation Discussion...
...Forecast Update...
Issued at 855 PM EST Sun Jan 25 2015
The surface low pressure center now is east of Louisville, with the
airport going over to northerly winds. Those winds will pick up from
the northwest the rest of the night as the gradient tightens up.
Precipitation across our region still is all rain, though just north
of us in IND`s area, seeing some snow reports from a few of the
bordering AWOS`s. HRRR still gives a brief shot at a deformation
band taking a swipe at our counties northeast of Louisville over the
next few hours, but otherwise the precip looks to be rather light,
save for the moderate rain showers along the KY/TN border right now.
Precipitation totals for the day so far are in the 1-2 tenths of an
inch range. This bodes a little better against their being lots of
black ice in the morning, as winds behind the low pressure will act
to dry out the roadways some. However we still have the chance for
freezing drizzle, according to forecast soundings, and this could
create a glaze on its own. Will keep the SPS going and let the mid
shift decide, as road reports are coming in, if an upgrade to a
Traveler`s Advisory is needed before the morning rush hour Monday.
Did another grid update, but forecast still looks on track, so no
need for a zone update.
Issued at 625 PM EST Sun Jan 25 2015
Looked through the forecast grids and tweaked toward current
conditions. After leaning towards the high-res consensus models for
the various parameters, ended up coming up with similar numbers for
QPF and snow totals as ongoing forecast. Still more concerned about
the threat for wet roads freezing than snow accumulations,
especially in the area already highlighted by the previous
forecaster. The possible saving grace here will be gusty northwest
winds that may help to dry off some of the roads before they get a
chance to freeze. Will be issuing updates through the evening and
overnight, so stay tuned.
.SHORT TERM (Now through Monday Night)...
Issued at 310 PM EST Sun Jan 25 2015
...Light wintry precipitation could cause slick spots overnight into
Monday morning...
The surface low associated with a strong PV anomaly is now working
across southern Illinois, and will continue to slide ESE across our
area this evening. Light to occasionally moderate rainfall will
continue late this afternoon and evening ahead of this feature. Most
spots should see around a quarter of an inch of rainfall, with
locaized spots up to a half an inch.
As the system departs to our east tonight, a sharp cold front will
slide NW to SE across our area with rapidly dropping temperatures
into the mid 20s. Enough low level moisture looks to linger during
this time to support a change over to light snow. Can`t rule out
some freezing drizzle as well as saturation only goes up to around
-7 or -8 C, bringing the availability of ice crystals into question.
Either way, the combination of wet roads (from recent heavier
rainfall), and potential for a light snow dusting, or a very thin
glaze of ice could lead to some travel problems ahead of and into
the morning commute. Confidence isn`t overly high in widespread
travel problems, but enough that special mention should be given.
Issued a Special Weather Statement to highlight concerns. If
confidence does become higher, then can`t rule out an upgraded
product with future updates. Overall, kept light snow as the
predominant p-type as we head toward dawn, with generally a half an
inch or less of snow accumulation. Most likely area to see more
problems with slick roads should be east of I-65 and along and north
of I-64.
Expect lingering light snow/flurries/or freezing drizzle along and
east of I-75 through the first part of Monday. Temperatures will
struggle for much of the day under steady cold advection and only
expect highs in the low and mid 30s. Skies should stay mostly cloudy
to cloudy under lingering low clouds.
As we move into Monday evening/Monday night, we`ll watch as the left
exit region of an upper jet dives sharply south southeastward
overnight. As it does so, 1000-700 mb moisture will pool underneath
and should result in some light precipitation across the area,
mostly in the form of light snow. Best location for this looks to be
along and west of I-65 Monday evening, moving to along and east of
I-65 late Monday night.
.LONG TERM (Tuesday through Sunday)...
Issued at 250 PM EST Sun Jan 25 2015
Several light precipitation chances still remain the long term
period as we remain in an unsettled weather pattern.
Tues small vort waves on the back side of a broad upper trough will
create snow shower chances during the morning hours and then
possibly changing over to a rain/snow mix west of I-65/remaining
snow east of I-65 during the afternoon hours. A light snow
accumulation may result from this snow shower activity on Tuesday.
Flurries will likely last into the evening hours.
The next precip chances will come Wed night into Thurs as a clipper
system moves east across the upper Midwest. At this time, the low
associated with this clipper looks to pass to our north and actually
pull up a decent amount of warm air on Wed night. Precip may start
as a brief wintry mix Wed night and then transition to plain rain as
upper 30s and lower 40s temps get pulled into our area. Southerly
winds and a noticeably warmer airmass will result in rain on Thurs
with high temps reaching the upper 40s to around 50. Precipitation
will likely end Thurs night as light snow or a rain/snow mix.
Temps will run slightly below normal Tues/Wed, then a warm day
expected for Thurs, and back to slightly below normal for the end of
the week.
The weekend forecast is much less certain with models backing off of
any major weather systems to bring us notable precip. Have
scaled back POPs to 20% for Sat night/Sun night with snow or
rain/snow being the p-type.
&&
.AVIATION (06Z TAF Update)...
Issued at 1215 AM EST Mon Jan 26 2015
Low-end MVFR and IFR conditions continue early this morning, but
there should be a slow improvement through the TAF period. A cold
front has just pushed through KSDF, and will slide through KBWG and
KLEX in the next couple of hours. This front will bring gusty
northwesterly winds, likely pushing 20-25 knots at times. In
addition, the passage of this front may bring a brief period of
snow, but it does not appear as if it will amount to much more than
a dusting. Clouds have been bouncing around high-end IFR and
fuel-alternate MVFR, but should slowly improve to fuel-alternate
MVFR later this morning at all sites, as drier low-level air works
in behind the front. This MVFR deck will slowly lift through the
day today, with northwesterly winds decreasing through the afternoon
as the low pressure system pushes to the east.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........RJS
Short Term.....BJS
Long Term......AMS
Aviation.......KJD
AREA FORECAST DISCUSSION
NWS JACKSON KY
1141 PM EST SUN JAN 25 2015
.UPDATE...
ISSUED AT 1137 PM EST SUN JAN 25 2015
GIVEN THE WELL ABOVE NORMAL TEMPERATURES EXPERIENCED TODAY /SOME
LOCATIONS IN THE 50S/...WE JUST REALLY HAVEN/T SEEN A LARGE COOL DOWN
ACROSS MUCH OF EASTERN KY THROUGH MOST OF THE EVENING. THIS IS
ESPECIALLY TRUE IN AREAS THAT HAVE NOT YET RECEIVED RAIN...OR HAVE
ONLY RECEIVED A SMALL AMOUNT. THIS BEING SAID...OTHER THAN ELEVATIONS
ABOVE 3000 FT...DON/T EXPECT RAIN TO START CHANGING OVER QUITE AS FAST
AS WHAT WAS IN THE PREVIOUS FORECAST. WORKED TO ADJUST THE LOW
TEMPERATURE FOR OVERNIGHT...BASED ON THE LATEST MODEL GUIDANCE AND
SOUNDINGS...AS WELL AS BASED ON THE ONGOING CONDITIONS WITH
TEMPERATURES AND COOLING DOWNSTREAM...PREVIOUS SNOW PACK...ETC.
WENT WITH A BLEND OF THE CURRENT FORECAST...THE LATEST HRRR /WHICH
SEEMS TO HAVE THE BEST INITIALIZATION FOR THIS SYSTEM/...AND A LITTLE
INFLUENCE FROM THE GFS...WHICH TRENDED CLOSER TO OVERALL THINKING FOR
THE LOW. THEN...ADJUSTED INDIVIDUAL LOCATIONS TO GET THEM WITHIN
BETTER TOLERANCE...INCLUDING BUMPING UP BLACK MOUNTAIN TO 29 DEGREES
AND OTHER TERRAIN ABOVE 2500 FEET TO BETWEEN 30 AND 32 DEGREES.
FURTHER MORE...GIVEN THE SLOW PROGRESS OF TEMPERATURES FALLING...WENT
AHEAD AND PUSHED BACK THE TIMING OF THE LOW TEMPERATURE TO 13Z
MONDAY. FROM HERE...USED A MIXTURE OF THE CONS-SHORT AND HAND EDITING
TO ADJUST THE DIURNAL CURVE FOR THE REMAINDER OF THE NIGHT.
ALL THINGS CONSIDERED...THE SLIGHT UPTICK IN TEMPERATURE FORECAST
WILL RESULT IN A SEVERAL HOUR DIFFERENCE IN THE RAIN CHANGING OVER TO
SNOW. THIS WILL KEEP ANY SNOW ACCUMULATIONS OUT OF THE FORECAST
THROUGH 12Z /WITH THE EXCEPTION OF BLACK MOUNTAIN/...AND LESS SNOW
ACCUMULATION IN FOR DURING THE DAY TOMORROW. BLACK MOUNTAIN IS
CURRENTLY AT 32 DEGREES...SO THEY MAY START TO MIX WITH SNOW AT ANY
TIME. HOWEVER...MOST OF THE REST OF THE AREA WILL LIKELY NOT SEE
SNOW MIXING IN UNTIL NEAR DAWN...THEN SLOWLY TRANSITION TO ALL SNOW
BETWEEN NOON AND 3PM. BY THIS POINT...MODEL SOUNDINGS ARE SHOWING A
STRONG AMOUNT OF DRY AIR CUTTING OFF SOME OF THE BEST ACCUMULATION
POTENTIAL DURING THE AFTERNOON. OVERALL...SNOW TOTALS WERE LOWERED
ACROSS THE CWA. EXPECT ELEVATIONS ABOVE 3000 FEET TO PICK UP THE
HIGHEST AMOUNTS...BETWEEN 1 AND 2 INCHES. SOME OF THE OTHER RIDGES
ACROSS THE AREA COULD SEE BETWEEN A HALF AN ONE INCH...BUT A MAJORITY
OF THE CWA WILL ONLY PICK UP A HALF INCH OR LESS. MOST OF THIS IS
STILL EXPECTED TO FALL BETWEEN 12 AND 18Z WHEN THE BEST LIFT AND
MOISTURE AND TEMPERATURES COMBINE...AND SURFACE TEMPERATURES FINALLY
FALL ENOUGH TO ALLOW FOR ACCUMULATING SNOW.
UPDATE ISSUED AT 706 PM EST SUN JAN 25 2015
FRESHENED UP THE GRIDS WITH THE LATEST OBSERVATIONAL DATA FOR
TEMPS...DEW POINTS...AND WINDS. THIS RESULTED IN LITTLE OVERALL
CHANGE FROM THE ONGOING FORECAST. BASED ON THE CURRENT RADAR
RETURNS...AND THE PWAT VALUES OVERNIGHT BEING AROUND A HALF INCH OR
LESS...WENT AHEAD AND REDUCED ANY MENTION OF MODERATE
RAINFALL/SNOWFALL TO LIGHT. JUST NOT SEEING A WHOLE LOT OF EVIDENCE
AT THIS POINT FOR MODERATE TO HEAVY INTENSITIES...THOUGH SNOW COULD
HAVE SOME HEAVIER SPOTS AT TIMES TOMORROW MORNING. LATEST NAM12
FORECAST SOUNDINGS REALLY START TO LOSE MOISTURE IN THE UPPER LEVELS
BETWEEN 6 AND 9 Z...WITH NOT MUCH LIFT EITHER...ALSO SUPPORTING
LIGHTER INTENSITIES. OTHERWISE...FORECAST SEEMS TO BE IN PRETTY GOOD
SHAPE OVER THE NEXT FEW HOURS. THE CENTER OF THE LOW IS CURRENTLY
OVER SOUTH CENTRAL KY AND MOVING OUR DIRECTION...WITH THE NEXT ROUND
OF LIGHT RAIN ABOUT TO SPREAD ACROSS THE CWA OVER THE NEXT 1 TO 2
HOURS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 409 PM EST SUN JAN 25 2015
SURFACE ANALYSIS AS OF 20Z ACROSS THE REGION FEATURES A SMALL LOW
PRESSURE SYSTEM OVER THE LOWER MIDWEST TRACKING EAST INTO THE OH
VALLEY THIS EVENING. AHEAD OF THIS...SOME SHOWER ACTIVITY HAS BEGUN
TO MOVE INTO THE AREA THIS AFTERNOON WITH MORE WIDESPREAD PRECIP BACK
WEST INTO WESTERN KENTUCKY AND SOUTHERN INDIANA. PLENTY OF SOUTHWEST
FLOW TODAY AND WAA INTO THE AREA HAS ALLOWED FOR TEMPS TO RISE INTO
THE UPPER 40S AND EVEN LOWER 50S ACROSS EASTERN KENTUCKY TODAY.
MODELS SHOWING THE COLD FRONT TO MOVE THROUGH LATER TONIGHT AFTER 00Z
WILL HAVE THE COLDER AIR MOVING IN LATER. THIS ADVECTION WILL BEGIN
IN EARNEST JUST AFTER 06Z AS THE FRONT MOVES THROUGH. EXPECTING A
CHANGE OVER IN THE HIGHER ELEVATIONS WITH ALREADY TEMPS AT BLACK
MOUNTAIN REACHING ITS HIGH FOR THE DAY IN THE UPPER 30S AND IS NOW
BEGINNING TO DROP OFF AT THIS HOUR. MODEL PROFILES SHOW A BRIEF
PERIOD OF GOOD OMEGA THROUGH THE LAST FEW HOURS OF THE EVENT AS THE
FRONT MOVES THROUGH. WITH COLD ENOUGH AIR MOVING IN...THERE COULD BE
SOME QUICK BURSTS OF SNOW IN THE HIGHER ELEVATIONS AND EVEN IN THE
VALLEYS WHERE COLDER AIR HAS FINALLY MOVED IN. SPEAKING OF
TEMPERATURES...LATE TONIGHT AND INTO THE DAY ON MONDAY...TEMPS WILL
BE FALLING INTO THE MORNING HOURS BUT SOME SLIGHT RADIATIONAL HEATING
DURING THE DAY BEFORE THE CORE OF THE AIR MASS MOVES IN MONDAY
AFTERNOON AND INTO MONDAY NIGHT WILL RESULT IN TEMPS RISING A DEGREE
OR TWO OR HOLDING STEADY THROUGH THE DAY TOMORROW. TEMPS OVER THE
HIGHER TERRAIN SHOULD SLOWLY FALL THROUGH THE DAY.
WINDS AFTER FRONTAL PASSAGE MONDAY MORNING WILL THEN SWITCH AROUND TO
THE NORTHWEST FOR A FAVORABLE DIRECTION FOR SOME UPSLOPE SNOW SHOWERS
THROUGH MONDAY AFTERNOON. MOISTURE DEPTH HANGS AROUND THROUGH MONDAY
MORNING AND INTO THE AFTERNOON WITH SOME DECENT LIFT REMAINING
ACCORDING TO THE NAM AND GFS SO SOME DECENT SNOW SHOWERS WILL HANG
AROUND THROUGH THE DAY ON MONDAY BEFORE TAPERING OFF TO FLURRIES FROM
WEST TO EAST INTO MONDAY NIGHT. THE CORE OF THE AIR MASS MOVING IN
WILL CAUSE TEMPS TO PLUMMET INTO THE MID 20S MONDAY NIGHT AND WILL
LIKELY ADD TO THE THREAT OF HAZARDOUS AND SLICK ROADS.
THEREFORE...HAVE ISSUED AN SPS TO HIGHLIGHT THIS THREAT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 420 PM EST SUN JAN 25 2015
A RATHER AMPLIFIED PATTERN IS EXPECTED TO BEGIN THE PERIOD. MODELS
REMAIN IN GENERALLY IN GOOD AGREEMENT FOR MOST OF THE PERIOD...WITH
DIFFERENCES INCREASING TOWARD THE END OF THE PERIOD. AT THE START OF
THE PERIOD A TROUGH IS EXPECTED TO BE IN PLACE FROM THE GREAT LAKES
SOUTH INTO THE MID ATLANTIC SATES AND OFF THE SOUTHEASTERN US
COAST...WITH A RIDGE OF HIGH PRESSURE FROM MEXICO NORTH INTO THE
SOUTHERN PLAINS AND ROCKIES. AT THE SFC THE A DEEP SFC LOW/BLIZZARD
WILL BE MOVING ALONG THE NORTHEAST US COAST TO START THE PERIOD WITH
A RIDGE OF HIGH PRESSURE AT THE SFC EXTENDING FROM ONTARIO INTO THE
GREAT LAKES AND MS VALLEY REGION. A SERIES OF SHORTWAVES IN NW FLOW
BETWEEN THE TWO WILL DROP FROM THE GREAT LAKES AND THROUGH THE OH
VALLEY AND APPALACHIANS TUESDAY INTO TUESDAY NIGHT. THIS WILL BRING
CHANCES FOR SNOW SHOWERS AND REINFORCE A COLD AIRMASS WITH 850 MB
TEMPS TO FALL TO THE -8C TO -10C RANGE BY LATE TUE AFTERNOON AND TUE
EVENING.
AS THE TROUGH AXIS LIFTS TO THE NORTH AND EAST AND THE SFC LOW MOVES
FURTHER UP THE EASTERN SEABOARD...HIGH PRESSURE WILL GRADUALLY BUILD
INTO THE LOWER OH VALLEY REGION AND APPALACHIANS TUE NIGHT INTO WED.
THE INFLUENCE OF THE RIDGING WILL WANE BY LATE WED NIGHT AS A
SHORTWAVE MOVING AROUND THE RIDGE OVER THE ROCKIES AND A NORTHERN
STREAM TROUGH BEGIN TO JOIN FORCES AND APPROACH THE GREAT LAKES AND
MS VALLEY REGION AS WELL AS THE LOWER OH VALLEY REGION. THE
ASSOCIATED SFC LOW SHOULD TRACK WELL NORTH OF THE AREA JUST TO THE
SOUTH OF THE SOUTHERN GREAT LAKES AND INTO THE MID ATLANTIC STATES
FROM WED NIGHT INTO THU NIGHT. THIS SYSTEM WILL HAVE SOMEWHAT
LIMITED MOISTURE...AND THIS SHOULD BE ANOTHER EVENT WHERE THE
ATMOSPHERE MOISTENS FROM THE TOP DOWN. AT THE ONSET...SOME SNOW
COULD MIX IN PENDING THE STRENGTH OF WARM AIR ADVECTION AND MOISTURE
ADVECTION LATE WED NIGHT INTO THU MORNING. THE CLOUDS ALSO MAY NOT
THICKEN QUICK ENOUGH TO PREVENT AT LEAST A MINOR RIDGE/VALLEY SPLIT
FOR THE VALLEYS ON WED EVENING. AT THIS POINT...A LOW IN THE MID TO
UPPER 20S OCCURRING AROUND 6Z ON THU IS EXPECTED.
COLDER AIR WILL WRAP BACK INTO THE REGION BEHIND THIS SYSTEM AND
POSSIBLY CHANGE ANY PRECIP BACK TO SNOW AS IT DEPARTS. HIGH PRESSURE
SHOULD THEN BUILD IN TO BRING A DRY START TO THE WEEKEND. THE ECMWF
LOWERS HEIGHTS MORE SIGNIFICANTLY ACROSS THE REGION AS WELL AS THE
GREAT LAKES AND EASTERN SEABOARD AT THE END OF THE PERIOD AND IS
THUS MUCH COLDER WITH THE AIRMASS. ANY SHORTWAVES AT THE END OF THE
PERIOD SHOULD BE RATHER MOISTURE STARVED WITH THE MODEL CONSENSUS
FAVORING ANYTHING THAT FALLS BEING SNOW. FOR TEMPS LATE IN THE
PERIOD...OPTED TO GO A TAD COLDER THAN THE CONSENSUS BLEND...MORE IN
LINE WITH ISC CONSENSUS AND GIVING A BIT MORE CREDIT TO THE PAST 2
ECMWF RUNS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 717 PM EST SUN JAN 25 2015
AVIATION CONCERNS WILL INCLUDE DROPPING CIGS THROUGH THIS EVENING
AND INTO TONIGHT. WENT A BIT MORE OPTIMISTIC THROUGH ABOUT 6Z
COMPARED TO THE PREVIOUS FORECAST...GIVEN THE SLOW MOVEMENT OF THE
SYSTEM RESULTING IN A LONGER TIME FOR LOWER CIGS DOWNSTREAM TO REACH
THE TAF SITES. EXPECT MVFR CIGS TO NOW REACH THE AREA BETWEEN 4 AND
7Z TONIGHT...SLOWLY DROPPING THROUGH THE NIGHT AND INTO THE MORNING
AS THE HEAVIER PRECIP ARRIVES AND THE THE LOWER LEVELS MOISTEN UP.
EXPECT AIRFIELD MINIMUM CIGS /OR JUST A COUPLE HUNDRED FEET ABOVE/ TO
ARRIVE BETWEEN 12 AND 14Z AND REMAIN THROUGH MUCH OF THE AFTERNOON.
IT IS ALSO AT THIS POINT THAT RAIN WILL LIKELY MAKE THE TRANSITION TO
ALL SNOW AS TEMPS DROP BELOW FREEZING ACROSS THE REGION. LOWEST
VISIBILITIES MAY ACTUALLY OCCUR DURING THIS CHANGEOVER PERIOD...BUT
COULD FLUCTUATE ANYWHERE BETWEEN MVFR AND AIRPORT MINIMUMS DEPENDING
ON THE INTENSITY OF THE BAND OF PRECIP PASSING OVERHEAD. WINDS
THROUGH THE NIGHT WILL BEGIN TO SHIFT AROUND TO THE NORTHWEST WITH
GUSTS UP TO 20 KNOTS POSSIBLE BY TOMORROW IN SOME LOCATIONS. SNOW
SHOULD LIGHTEN UP AND TAPER OFF LATE IN THE TAF PERIOD WITH IMPROVING
CONDITIONS EXPECTED...GENERALLY AFTER 18Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JMW
SHORT TERM...SHALLENBERGER
LONG TERM...JP
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS JACKSON KY
1138 PM EST SUN JAN 25 2015
.UPDATE...
ISSUED AT 1137 PM EST SUN JAN 25 2015
GIVEN THE WELL ABOVE NORMAL TEMPERATURES EXPERIENCED TODAY /SOME
LOCATIONS IN THE 50S/...WE JUST REALLY HAVEN/T SEEN A LARGE COOL DOWN
ACROSS MUCH OF EASTERN KY THROUGH MOST OF THE EVENING. THIS IS
ESPECIALLY TRUE IN AREAS THAT HAVE NOT YET RECEIVED RAIN...OR HAVE
ONLY RECEIVED A SMALL AMOUNT. THIS BEING SAID...OTHER THAN ELEVATIONS
ABOVE 3000 FT...DON/T EXPECT RAIN TO START CHANGING OVER QUITE AS FAST
AS WHAT WAS IN THE PREVIOUS FORECAST. WORKED TO ADJUST THE LOW
TEMPERATURE FOR OVERNIGHT...BASED ON THE LATEST MODEL GUIDANCE AND
SOUNDINGS...AS WELL AS BASED ON THE ONGOING CONDITIONS WITH
TEMPERATURES AND COOLING DOWNSTREAM...PREVIOUS SNOW PACK...ETC.
WENT WITH A BLEND OF THE CURRENT FORECAST...THE LATEST HRRR /WHICH
SEEMS TO HAVE THE BEST INITIALIZATION FOR THIS SYSTEM/...AND A LITTLE
INFLUENCE FROM THE GFS...WHICH TRENDED CLOSER TO OVERALL THINKING FOR
THE LOW. THEN...ADJUSTED INDIVIDUAL LOCATIONS TO GET THEM WITHIN
BETTER TOLERANCE...INCLUDING BUMPING UP BLACK MOUNTAIN TO 29 DEGREES
AND OTHER TERRAIN ABOVE 2500 FEET TO BETWEEN 30 AND 32 DEGREES.
FURTHER MORE...GIVEN THE SLOW PROGRESS OF TEMPERATURES FALLING...WENT
AHEAD AND PUSHED BACK THE TIMING OF THE LOW TEMPERATURE TO 13Z
MONDAY. FROM HERE...USED A MIXTURE OF THE CONS-SHORT AND HAND EDITING
TO ADJUST THE DIURNAL CURVE FOR THE REMAINDER OF THE NIGHT.
ALL THINGS CONSIDERED...THE SLIGHT UPTICK IN TEMPERATURE FORECAST
WILL RESULT IN A SEVERAL HOUR DIFFERENCE IN THE RAIN CHANGING OVER TO
SNOW. THIS WILL KEEP ANY SNOW ACCUMULATIONS OUT OF THE FORECAST
THROUGH 12Z /WITH THE EXCEPTION OF BLACK MOUNTAIN/...AND LESS SNOW
ACCUMULATION IN FOR DURING THE DAY TOMORROW. BLACK MOUNTAIN IS
CURRENTLY AT 32 DEGREES...SO THEY MAY START TO MIX WITH SNOW AT ANY
TIME. HOWEVER...MOST OF THE REST OF THE AREA WILL LIKELY NOT SEE
SNOW MIXING IN UNTIL NEAR DAWN...THEN SLOWLY TRANSITION TO ALL SNOW
BETWEEN NOON AND 3PM. BY THIS POINT...MODEL SOUNDINGS ARE SHOWING A
STRONG AMOUNT OF DRY AIR CUTTING OFF SOME OF THE BEST ACCUMULATION
POTENTIAL DURING THE AFTERNOON. OVERALL...SNOW TOTALS WERE LOWERED
ACROSS THE CWA. EXPECT ELEVATIONS ABOVE 3000 FEET TO PICK UP THE
HIGHEST AMOUNTS...BETWEEN 1 AND 2 INCHES. SOME OF THE OTHER RIDGES
ACROSS THE AREA COULD SEE BETWEEN A HALF AN ONE INCH...BUT A MAJORITY
OF THE CWA WILL ONLY PICK UP A HALF INCH OR LESS. MOST OF THIS IS
STILL EXPECTED TO FALL BETWEEN 12 AND 18Z WHEN THE BEST LIFT AND
MOISTURE AND TEMPERATURES COMBINE.
UPDATE ISSUED AT 706 PM EST SUN JAN 25 2015
FRESHENED UP THE GRIDS WITH THE LATEST OBSERVATIONAL DATA FOR
TEMPS...DEW POINTS...AND WINDS. THIS RESULTED IN LITTLE OVERALL
CHANGE FROM THE ONGOING FORECAST. BASED ON THE CURRENT RADAR
RETURNS...AND THE PWAT VALUES OVERNIGHT BEING AROUND A HALF INCH OR
LESS...WENT AHEAD AND REDUCED ANY MENTION OF MODERATE
RAINFALL/SNOWFALL TO LIGHT. JUST NOT SEEING A WHOLE LOT OF EVIDENCE
AT THIS POINT FOR MODERATE TO HEAVY INTENSITIES...THOUGH SNOW COULD
HAVE SOME HEAVIER SPOTS AT TIMES TOMORROW MORNING. LATEST NAM12
FORECAST SOUNDINGS REALLY START TO LOSE MOISTURE IN THE UPPER LEVELS
BETWEEN 6 AND 9 Z...WITH NOT MUCH LIFT EITHER...ALSO SUPPORTING
LIGHTER INTENSITIES. OTHERWISE...FORECAST SEEMS TO BE IN PRETTY GOOD
SHAPE OVER THE NEXT FEW HOURS. THE CENTER OF THE LOW IS CURRENTLY
OVER SOUTH CENTRAL KY AND MOVING OUR DIRECTION...WITH THE NEXT ROUND
OF LIGHT RAIN ABOUT TO SPREAD ACROSS THE CWA OVER THE NEXT 1 TO 2
HOURS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 409 PM EST SUN JAN 25 2015
SURFACE ANALYSIS AS OF 20Z ACROSS THE REGION FEATURES A SMALL LOW
PRESSURE SYSTEM OVER THE LOWER MIDWEST TRACKING EAST INTO THE OH
VALLEY THIS EVENING. AHEAD OF THIS...SOME SHOWER ACTIVITY HAS BEGUN
TO MOVE INTO THE AREA THIS AFTERNOON WITH MORE WIDESPREAD PRECIP BACK
WEST INTO WESTERN KENTUCKY AND SOUTHERN INDIANA. PLENTY OF SOUTHWEST
FLOW TODAY AND WAA INTO THE AREA HAS ALLOWED FOR TEMPS TO RISE INTO
THE UPPER 40S AND EVEN LOWER 50S ACROSS EASTERN KENTUCKY TODAY.
MODELS SHOWING THE COLD FRONT TO MOVE THROUGH LATER TONIGHT AFTER 00Z
WILL HAVE THE COLDER AIR MOVING IN LATER. THIS ADVECTION WILL BEGIN
IN EARNEST JUST AFTER 06Z AS THE FRONT MOVES THROUGH. EXPECTING A
CHANGE OVER IN THE HIGHER ELEVATIONS WITH ALREADY TEMPS AT BLACK
MOUNTAIN REACHING ITS HIGH FOR THE DAY IN THE UPPER 30S AND IS NOW
BEGINNING TO DROP OFF AT THIS HOUR. MODEL PROFILES SHOW A BRIEF
PERIOD OF GOOD OMEGA THROUGH THE LAST FEW HOURS OF THE EVENT AS THE
FRONT MOVES THROUGH. WITH COLD ENOUGH AIR MOVING IN...THERE COULD BE
SOME QUICK BURSTS OF SNOW IN THE HIGHER ELEVATIONS AND EVEN IN THE
VALLEYS WHERE COLDER AIR HAS FINALLY MOVED IN. SPEAKING OF
TEMPERATURES...LATE TONIGHT AND INTO THE DAY ON MONDAY...TEMPS WILL
BE FALLING INTO THE MORNING HOURS BUT SOME SLIGHT RADIATIONAL HEATING
DURING THE DAY BEFORE THE CORE OF THE AIR MASS MOVES IN MONDAY
AFTERNOON AND INTO MONDAY NIGHT WILL RESULT IN TEMPS RISING A DEGREE
OR TWO OR HOLDING STEADY THROUGH THE DAY TOMORROW. TEMPS OVER THE
HIGHER TERRAIN SHOULD SLOWLY FALL THROUGH THE DAY.
WINDS AFTER FRONTAL PASSAGE MONDAY MORNING WILL THEN SWITCH AROUND TO
THE NORTHWEST FOR A FAVORABLE DIRECTION FOR SOME UPSLOPE SNOW SHOWERS
THROUGH MONDAY AFTERNOON. MOISTURE DEPTH HANGS AROUND THROUGH MONDAY
MORNING AND INTO THE AFTERNOON WITH SOME DECENT LIFT REMAINING
ACCORDING TO THE NAM AND GFS SO SOME DECENT SNOW SHOWERS WILL HANG
AROUND THROUGH THE DAY ON MONDAY BEFORE TAPERING OFF TO FLURRIES FROM
WEST TO EAST INTO MONDAY NIGHT. THE CORE OF THE AIR MASS MOVING IN
WILL CAUSE TEMPS TO PLUMMET INTO THE MID 20S MONDAY NIGHT AND WILL
LIKELY ADD TO THE THREAT OF HAZARDOUS AND SLICK ROADS.
THEREFORE...HAVE ISSUED AN SPS TO HIGHLIGHT THIS THREAT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 420 PM EST SUN JAN 25 2015
A RATHER AMPLIFIED PATTERN IS EXPECTED TO BEGIN THE PERIOD. MODELS
REMAIN IN GENERALLY IN GOOD AGREEMENT FOR MOST OF THE PERIOD...WITH
DIFFERENCES INCREASING TOWARD THE END OF THE PERIOD. AT THE START OF
THE PERIOD A TROUGH IS EXPECTED TO BE IN PLACE FROM THE GREAT LAKES
SOUTH INTO THE MID ATLANTIC SATES AND OFF THE SOUTHEASTERN US
COAST...WITH A RIDGE OF HIGH PRESSURE FROM MEXICO NORTH INTO THE
SOUTHERN PLAINS AND ROCKIES. AT THE SFC THE A DEEP SFC LOW/BLIZZARD
WILL BE MOVING ALONG THE NORTHEAST US COAST TO START THE PERIOD WITH
A RIDGE OF HIGH PRESSURE AT THE SFC EXTENDING FROM ONTARIO INTO THE
GREAT LAKES AND MS VALLEY REGION. A SERIES OF SHORTWAVES IN NW FLOW
BETWEEN THE TWO WILL DROP FROM THE GREAT LAKES AND THROUGH THE OH
VALLEY AND APPALACHIANS TUESDAY INTO TUESDAY NIGHT. THIS WILL BRING
CHANCES FOR SNOW SHOWERS AND REINFORCE A COLD AIRMASS WITH 850 MB
TEMPS TO FALL TO THE -8C TO -10C RANGE BY LATE TUE AFTERNOON AND TUE
EVENING.
AS THE TROUGH AXIS LIFTS TO THE NORTH AND EAST AND THE SFC LOW MOVES
FURTHER UP THE EASTERN SEABOARD...HIGH PRESSURE WILL GRADUALLY BUILD
INTO THE LOWER OH VALLEY REGION AND APPALACHIANS TUE NIGHT INTO WED.
THE INFLUENCE OF THE RIDGING WILL WANE BY LATE WED NIGHT AS A
SHORTWAVE MOVING AROUND THE RIDGE OVER THE ROCKIES AND A NORTHERN
STREAM TROUGH BEGIN TO JOIN FORCES AND APPROACH THE GREAT LAKES AND
MS VALLEY REGION AS WELL AS THE LOWER OH VALLEY REGION. THE
ASSOCIATED SFC LOW SHOULD TRACK WELL NORTH OF THE AREA JUST TO THE
SOUTH OF THE SOUTHERN GREAT LAKES AND INTO THE MID ATLANTIC STATES
FROM WED NIGHT INTO THU NIGHT. THIS SYSTEM WILL HAVE SOMEWHAT
LIMITED MOISTURE...AND THIS SHOULD BE ANOTHER EVENT WHERE THE
ATMOSPHERE MOISTENS FROM THE TOP DOWN. AT THE ONSET...SOME SNOW
COULD MIX IN PENDING THE STRENGTH OF WARM AIR ADVECTION AND MOISTURE
ADVECTION LATE WED NIGHT INTO THU MORNING. THE CLOUDS ALSO MAY NOT
THICKEN QUICK ENOUGH TO PREVENT AT LEAST A MINOR RIDGE/VALLEY SPLIT
FOR THE VALLEYS ON WED EVENING. AT THIS POINT...A LOW IN THE MID TO
UPPER 20S OCCURRING AROUND 6Z ON THU IS EXPECTED.
COLDER AIR WILL WRAP BACK INTO THE REGION BEHIND THIS SYSTEM AND
POSSIBLY CHANGE ANY PRECIP BACK TO SNOW AS IT DEPARTS. HIGH PRESSURE
SHOULD THEN BUILD IN TO BRING A DRY START TO THE WEEKEND. THE ECMWF
LOWERS HEIGHTS MORE SIGNIFICANTLY ACROSS THE REGION AS WELL AS THE
GREAT LAKES AND EASTERN SEABOARD AT THE END OF THE PERIOD AND IS
THUS MUCH COLDER WITH THE AIRMASS. ANY SHORTWAVES AT THE END OF THE
PERIOD SHOULD BE RATHER MOISTURE STARVED WITH THE MODEL CONSENSUS
FAVORING ANYTHING THAT FALLS BEING SNOW. FOR TEMPS LATE IN THE
PERIOD...OPTED TO GO A TAD COLDER THAN THE CONSENSUS BLEND...MORE IN
LINE WITH ISC CONSENSUS AND GIVING A BIT MORE CREDIT TO THE PAST 2
ECMWF RUNS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 717 PM EST SUN JAN 25 2015
AVIATION CONCERNS WILL INCLUDE DROPPING CIGS THROUGH THIS EVENING
AND INTO TONIGHT. WENT A BIT MORE OPTIMISTIC THROUGH ABOUT 6Z
COMPARED TO THE PREVIOUS FORECAST...GIVEN THE SLOW MOVEMENT OF THE
SYSTEM RESULTING IN A LONGER TIME FOR LOWER CIGS DOWNSTREAM TO REACH
THE TAF SITES. EXPECT MVFR CIGS TO NOW REACH THE AREA BETWEEN 4 AND
7Z TONIGHT...SLOWLY DROPPING THROUGH THE NIGHT AND INTO THE MORNING
AS THE HEAVIER PRECIP ARRIVES AND THE THE LOWER LEVELS MOISTEN UP.
EXPECT AIRFIELD MINIMUM CIGS /OR JUST A COUPLE HUNDRED FEET ABOVE/ TO
ARRIVE BETWEEN 12 AND 14Z AND REMAIN THROUGH MUCH OF THE AFTERNOON.
IT IS ALSO AT THIS POINT THAT RAIN WILL LIKELY MAKE THE TRANSITION TO
ALL SNOW AS TEMPS DROP BELOW FREEZING ACROSS THE REGION. LOWEST
VISIBILITIES MAY ACTUALLY OCCUR DURING THIS CHANGEOVER PERIOD...BUT
COULD FLUCTUATE ANYWHERE BETWEEN MVFR AND AIRPORT MINIMUMS DEPENDING
ON THE INTENSITY OF THE BAND OF PRECIP PASSING OVERHEAD. WINDS
THROUGH THE NIGHT WILL BEGIN TO SHIFT AROUND TO THE NORTHWEST WITH
GUSTS UP TO 20 KNOTS POSSIBLE BY TOMORROW IN SOME LOCATIONS. SNOW
SHOULD LIGHTEN UP AND TAPER OFF LATE IN THE TAF PERIOD WITH IMPROVING
CONDITIONS EXPECTED...GENERALLY AFTER 18Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JMW
SHORT TERM...SHALLENBERGER
LONG TERM...JP
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
657 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 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 651 PM EST TUE JAN 27 2015
BASED ON UPSTREAM CLOUDS OVER MUCH OF WI AND MN AND ALSO MID CLOUDS
SPREADING ACROSS THE UPPER LAKES FROM ONTARIO...LOW CLOUDS ACROSS
MUCH OF WEST AND CENTRAL UPPER MI MAY BE SLOW TO DEPART. EXPECT MVFR
CONDITIONS TO PERSIST AT ALL THE TAF SITES THROUGH THE FCST PD. THERE
MAY BE SLIGHT IMPROVEMENT TO HIGH END MVFR BY LATE WED MORNING AND
AFTERNOON WITH INCREASED MIXING FROM SOUTH WINDS.
&&
.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...VOSS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
437 PM EST MON JAN 26 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 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1249 PM EST MON JAN 26 2015
IN THE WAKE OF STEADIER SNOW THAT AFFECTED KIWD THIS MORNING...
EXPECT MVFR CONDITIONS TO PREVAIL THIS AFTN. ANOTHER DISTURBANCE
TRACKING SSE WILL BRING A ROUND OF -SN TO KIWD/KCMX/KSAW LATE THIS
AFTN/EVENING. WHILE KIWD SHOULD REMAIN MVFR AS THE -SN
PASSES...STEADIER SNOW AT KCMX/KSAW WILL LIKELY DROP CONDITIONS
FROM VFR TO IFR. LINGERING MOISTURE BEHIND THE DISTURBANCE WILL
RESULT IN CONDITIONS FALLING TO IFR AT KIWD BY LATE EVENING. IFR/LOW
MVFR CIGS WILL LIKELY PERSIST AT ALL TERMINALS THRU TUE MORNING.
&&
.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...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
435 PM EST MON JAN 26 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 THROUGH SUNDAY)
ISSUED AT 105 AM EST MON JAN 26 2015
WITH THE 500MB LOW AND THE AXIS OF THE 500MB TROUGH SHIFTED OVER THE
NEW ENGLAND STATES TUESDAY...THE RIDGE CURRENTLY OVER THE W HALF OF
THE NATION WILL BE ABLE TO SHIFT ACROSS THE CENTRAL PLAINS AND UPPER
GREAT LAKES TUESDAY INTO EARLY WEDNESDAY.
AT THE SFC...A RIDGE WILL BE ABLE TO SLIDE ACROSS LAKE SUPERIOR
TUESDAY /EXTENDING FROM MN UP THROUGH NEWFOUNDLAND/...WHICH WILL
LINGER INTO TUESDAY NIGHT AS THE MAIN AREA OF HIGH PRESSURE PUSHES
INTO THE OHIO VALLEY TUESDAY NIGHT INTO WEDNESDAY. THE RESULT WILL
BE A DRY PERIOD AT LEAST UNTIL MID DAY WEDNESDAY...ALTHOUGH THERE
MAY STILL BE SOME CLOUDS LINGERING/STUCK BELOW THE 850-900MB
SUBSIDENCE INVERSION. TRICKY CLOUD COVER FCST FOR THIS PERIOD.
WEDNESDAY LOOK TO BE THE LAST WARM DAY IN A WHILE...WITH
TEMPERATURES NEAR FREEZING. 850MB TEMPS ON S FLOW WILL RISE TO -1 TO
-4C THROUGH THE DAYTIME HOURS AS THICKER CLOUDS INVADE FROM THE NW.
AN ELONGATED AREA OF LOW PRESSURE OVER THE N AND CENTRAL PLAINS
WEDNESDAY MORNING WILL EDGE E ACROSS IL AND IN THURSDAY
MORNING...AND OFF TO THE LOWER GREAT LAKES AND OFF THE MID ATLANTIC
STATES FRIDAY. THIS WILL BRING A TROUGH ACROSS OUR AREA WEDNESDAY
NIGHT THROUGH THURSDAY EVENING...WHICH WILL BE ENHANCED BY THE
SUPPRESSION OF THE 500MB RIDGE WEDNESDAY EVENING AND THURSDAY. LOOK
FOR A WIDESPREAD 2-5IN OF SNOW WITH SLR VALUES AROUND 15:1. EXPECT
THE HIGHER VALUES OVER THE N HALF OF UPPER MI AS IT WILL LIKELY TAKE
UNTIL LATE AFTERNOON/EARLY EVENING FOR SNOW TO BEGIN S CENTRAL. WILL
NOT GO QUITE AS QUICK WITH THE INVADING PRECIP AS THE 00Z NAM...BUT
A BLENDED SOLUTION SOUNDS REASONABLE. A WINTER WX ADVISORY MAY BE
NEEDED IF THE 2-5IN CAN FALL IN A 12HR PERIOD. WILL CONTINUE TO LOOK
INTO THIS FOR POSSIBLE POSTING OF HEADLINES ON TUESDAY...AND
HIGHLIGHT THE POTENTIAL FOR LIGHT TO MODERATE SNOW IN THE HWO.
N FLOW BEHIND THE EXITING SFC TROUGH THURSDAY AFTERNOON WILL BE THE
START OF OUR COOL DOWN...WITH 850MB TEMPS FALLING TO -8 TO -10C.
WHILE NOT QUITE OPTIMAL FOR LAKE EFFECT YET...SOME LAKE ENHANCEMENT
WILL BE LIKELY ALONG THE UPSLOPE N SNOWBELTS ALONG LAKE SUPERIOR
THURSDAY AS THE SFC LOW EXITS TO THE LOWER GREAT LAKES/PENNSYLVANIA
FRIDAY EVENING.
DESPITE SFC-500MB RIDGING ON FRIDAY...A FEW LINGERING LES WILL
REMAIN ALONG THE LAKE SUPERIOR SHORELINES. DON/T EXPECT MUCH IN THE
WAY OF ACCUMULATIONS AS THE MOISTURE IS AGAIN TRAPPED BELOW 850MB.
BUT WILL THE MOISTURE LAYER IN THE DGZ /850MB TEMPS OF -15 TO
-17C/...SOME LIGHT ACCUMULATIONS WILL BE POSSIBLE.
SLIGHTLY WARMER AIR WILL PUSH IN THROUGH EARLY SATURDAY MORNING AS
THE SFC RIDGE EXITS TO THE LOWER GREAT LAKES...AND IN ADVANCE OF LOW
PRESSURE DEVELOPING NEARING FROM THE N PLAINS STATES.
SOME OF THE COLDEST AIR OF THE SEASON WILL PUSH INTO THE UPPER GREAT
LAKES SATURDAY AFTERNOON ON. THERE CONTINUES TO BE SOME TIMING
ISSUES ON THE ORDER OF AROUND 6HRS...WHICH IS PRETTY MINOR THIS FAR
OUT IN THE FCST...AND A BLENDED SOLUTION LOOKS REASONABLE. 850MB
TEMPS OF -20 TO -30C WILL SETTLE IN SUNDAY AFTERNOON AS THE SFC LOW
EXITS AND THE MAIN 500MB TROUGH PUSHES ACROSS THE UPPER GREAT LAKES.
LOOK FOR FINE LES THAT WILL BE GOOD AT REDUCING VIS...ESPECIALLY IF
THE STRONGER NW WINDS OF THE 25/12Z ECMWF ARE CORRECT/.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1249 PM EST MON JAN 26 2015
IN THE WAKE OF STEADIER SNOW THAT AFFECTED KIWD THIS MORNING...
EXPECT MVFR CONDITIONS TO PREVAIL THIS AFTN. ANOTHER DISTURBANCE
TRACKING SSE WILL BRING A ROUND OF -SN TO KIWD/KCMX/KSAW LATE THIS
AFTN/EVENING. WHILE KIWD SHOULD REMAIN MVFR AS THE -SN
PASSES...STEADIER SNOW AT KCMX/KSAW WILL LIKELY DROP CONDITIONS
FROM VFR TO IFR. LINGERING MOISTURE BEHIND THE DISTURBANCE WILL
RESULT IN CONDITIONS FALLING TO IFR AT KIWD BY LATE EVENING. IFR/LOW
MVFR CIGS WILL LIKELY PERSIST AT ALL TERMINALS THRU TUE MORNING.
&&
.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...KF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1249 PM EST MON JAN 26 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 416 AM EST MON JAN 26 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A NW FLOW ALOFT
OVER CENTRAL NAMERICA BTWN A HI AMPLITUDE RDG OVER THE W AND A DEEP
TROF OVER THE E. THERE ARE 2 SHRTWVS OF INTEREST EMBEDDED IN THE NW
FLOW...THE FIRST IS DIGGING SEWD INTO NW MN WHILE ANOTHER IS MOVING
SEWD THRU NRN MANITOBA/FAR NW ONTARIO. A FAIRLY VIGOROUS 998MB LO
OVER CENTRAL MANITOBA IS THE SFC REFLECTION OF THESE DISTURBANCES.
UPR MI IS UNDER THE SSW FLOW BTWN THIS LO AND SLOWLY RETREATING
ARCTIC HI PRES NEAR THE ONTARIO/QUEBEC BORDER. THE PRES GRADIENT IS
MUCH TIGHTER OVER MN CLOSER TO THE LO...AND SOME LIGHT SN IS NOTED
ON THE SFC OBS/RADAR COMPOSITES MOVING THRU NRN MN. ALTHOUGH NEARBY
RAOBS SHOW SOME MID LVL MSTR WITH 00Z H7 DEWPT DEPRESSIONS OF ONLY
2C AND 4C AT YPL AND INL RESPECTIVELY...THE RAOBS ALSO INDICATE SOME
LLVL DRY AIR LINGERS ACROSS THE AREA...WITH 00Z H85 DEWPT
DEPRESSIONS OF 26C AT MPX...22C AT GRB AND EVEN 13C AT INL/10C AT
YPL CLOSER TO THE SFC LO. SO THE OBSVD SN INTENSITY AND COVERAGE IS
NOT THAT GREAT DESPITE SOME FAIRLY STRONG ISENTROPIC ASCENT NOTED ON
THE 290K SFC /ABOUT H7/.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS/SN AMOUNTS
ASSOCIATED WITH THE 2 SHRTWVS NOTED ABOVE. SINCE THERE ARE 2
DISTURBANCES/SEPARATE AREAS OF DEEP LYR FORCING...THE INITIAL SHRTWV
IS TENDING TO TRACK FARTHER W DUE TO THE HI AMPLITUDE PATTERN AND
LARGER SCALE MSTR INFLOW WL REMAIN FAIRLY LIMITED...EXPECT SN
AMOUNTS TO BE SUB ADVY.
SHRTWV NOW MOVING INTO NW MN IS PROGGED TO DIG SSEWD THIS MRNG...
WITH AREA OF DEEP LYR QVECTOR CNVGC/SHARPER ISENTROPIC ASCENT ON THE
290K SFC IMPACTING MAINLY JUST THE WRN CWA THIS MRNG. THE SECOND
SHRTWV WL REACH FAR NW LK SUP LATE THIS AFTN...WITH AREA OF
DPVA/DEEP LYR QVECTOR CNVGC BUT WEAKER ISENTROPIC ASCENT INFLUENCING
MUCH OF THE CWA THIS AFTN/EVNG BEFORE FADING OVERNGT WITH APRCH OF
TRAILING SHRTWV RDG AXIS AND DNVA/DEEP LYR QVECTOR DVGC. WHILE THE
EXPECTED FORCING MAY JUSTIFY LIKELY TO CATEGORICAL POPS UNDER THE
BETTER FORCING...LIMITED MSTR INFLOW WL BE A MAJOR LIMITING FACTOR.
IN FACT THE H7 SPECIFIC HUMIDITY FCST UP TO 2 G/KG OVER THE W THIS
MRNG INTO EARLY AFTN IS FCST TO DIMINISH DURING THE EVENT. SO
DESPITE A FAVORABLE DEPTH/LOCATION OF THE DGZ CENTERED ARND 10K
FT...EXPECT SN TOTALS NOT MORE THAN 1 TO PERHAPS 3 INCHES...
HEAVIEST OVER THE W HALF BECAUSE THESE AREAS WL BE IMPACTED BY BOTH
SHRTWVS. SINCE SLOWLY BACKING LLVL FLOW WL ATTEMPT TO MAINTAIN FEED
OF NEAR SFC DRY AIR INTO THE E...FCST LOWER POPS/SN AMOUNTS IN THAT
AREA. IN FACT...THE FAR E MAY SEE LITTLE SN THRU TNGT. ONE CONCERN
FOR HEAVIER SN WL BE OVER THE SCENTRAL LATER THIS AFTN/EVNG DOWWIND
OF LK MI IN THE LLVL SLY FLOW AND WHEN DEEPER MSTR/FORCING
ASSOCIATED WITH 2ND SHRTWV WL ARRIVE IN THE PRESENCE OF H85 TEMPS /-
10 TO -12C/ SUFFICIENTLY COLD FOR SOME LK ENHANCEMENT.
HOWEVER...FAIRLY SHARP DIRECTIONAL SHEAR WITH BACKING LLVL SE FLOW
TURNING TO THE SSW AT H85 AND MAINTAINING A FEED OF NEAR SFC DRY AIR
MAY OFFSET THIS POTENTIAL. BUT OPTED TO MAINTAIN SOME HIER
CATEGORICAL POPS/QPF CENTERED NEAR ESCANABA TO ACCOUNT FOR THE
POTENTIAL LK ENHANCEMENT.
TEMPS TODAY SHOULD RECOVER INTO THE 20S OVER MOST OF THE CWA EXCEPT
OVER THE E...CLOSER TO SLOWLY RETREATING HI PRES/CORE OF COLDER AIR
AND WHERE H85 TEMPS ARE FCST TO RISE NO HIER THAN -12 TO -13C.
LINGERING CLDS THRU TNGT WL GREATLY LIMIT THE DIURNAL TEMP FALL. THE
COLDEST TEMPS AOB 10F WL ONCE AGAIN OCCUR OVER THE E.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 105 AM EST MON JAN 26 2015
WITH THE 500MB LOW AND THE AXIS OF THE 500MB TROUGH SHIFTED OVER THE
NEW ENGLAND STATES TUESDAY...THE RIDGE CURRENTLY OVER THE W HALF OF
THE NATION WILL BE ABLE TO SHIFT ACROSS THE CENTRAL PLAINS AND UPPER
GREAT LAKES TUESDAY INTO EARLY WEDNESDAY.
AT THE SFC...A RIDGE WILL BE ABLE TO SLIDE ACROSS LAKE SUPERIOR
TUESDAY /EXTENDING FROM MN UP THROUGH NEWFOUNDLAND/...WHICH WILL
LINGER INTO TUESDAY NIGHT AS THE MAIN AREA OF HIGH PRESSURE PUSHES
INTO THE OHIO VALLEY TUESDAY NIGHT INTO WEDNESDAY. THE RESULT WILL
BE A DRY PERIOD AT LEAST UNTIL MID DAY WEDNESDAY...ALTHOUGH THERE
MAY STILL BE SOME CLOUDS LINGERING/STUCK BELOW THE 850-900MB
SUBSIDENCE INVERSION. TRICKY CLOUD COVER FCST FOR THIS PERIOD.
WEDNESDAY LOOK TO BE THE LAST WARM DAY IN A WHILE...WITH
TEMPERATURES NEAR FREEZING. 850MB TEMPS ON S FLOW WILL RISE TO -1 TO
-4C THROUGH THE DAYTIME HOURS AS THICKER CLOUDS INVADE FROM THE NW.
AN ELONGATED AREA OF LOW PRESSURE OVER THE N AND CENTRAL PLAINS
WEDNESDAY MORNING WILL EDGE E ACROSS IL AND IN THURSDAY
MORNING...AND OFF TO THE LOWER GREAT LAKES AND OFF THE MID ATLANTIC
STATES FRIDAY. THIS WILL BRING A TROUGH ACROSS OUR AREA WEDNESDAY
NIGHT THROUGH THURSDAY EVENING...WHICH WILL BE ENHANCED BY THE
SUPPRESSION OF THE 500MB RIDGE WEDNESDAY EVENING AND THURSDAY. LOOK
FOR A WIDESPREAD 2-5IN OF SNOW WITH SLR VALUES AROUND 15:1. EXPECT
THE HIGHER VALUES OVER THE N HALF OF UPPER MI AS IT WILL LIKELY TAKE
UNTIL LATE AFTERNOON/EARLY EVENING FOR SNOW TO BEGIN S CENTRAL. WILL
NOT GO QUITE AS QUICK WITH THE INVADING PRECIP AS THE 00Z NAM...BUT
A BLENDED SOLUTION SOUNDS REASONABLE. A WINTER WX ADVISORY MAY BE
NEEDED IF THE 2-5IN CAN FALL IN A 12HR PERIOD. WILL CONTINUE TO LOOK
INTO THIS FOR POSSIBLE POSTING OF HEADLINES ON TUESDAY...AND
HIGHLIGHT THE POTENTIAL FOR LIGHT TO MODERATE SNOW IN THE HWO.
N FLOW BEHIND THE EXITING SFC TROUGH THURSDAY AFTERNOON WILL BE THE
START OF OUR COOL DOWN...WITH 850MB TEMPS FALLING TO -8 TO -10C.
WHILE NOT QUITE OPTIMAL FOR LAKE EFFECT YET...SOME LAKE ENHANCEMENT
WILL BE LIKELY ALONG THE UPSLOPE N SNOWBELTS ALONG LAKE SUPERIOR
THURSDAY AS THE SFC LOW EXITS TO THE LOWER GREAT LAKES/PENNSYLVANIA
FRIDAY EVENING.
DESPITE SFC-500MB RIDGING ON FRIDAY...A FEW LINGERING LES WILL
REMAIN ALONG THE LAKE SUPERIOR SHORELINES. DON/T EXPECT MUCH IN THE
WAY OF ACCUMULATIONS AS THE MOISTURE IS AGAIN TRAPPED BELOW 850MB.
BUT WILL THE MOISTURE LAYER IN THE DGZ /850MB TEMPS OF -15 TO
-17C/...SOME LIGHT ACCUMULATIONS WILL BE POSSIBLE.
SLIGHTLY WARMER AIR WILL PUSH IN THROUGH EARLY SATURDAY MORNING AS
THE SFC RIDGE EXITS TO THE LOWER GREAT LAKES...AND IN ADVANCE OF LOW
PRESSURE DEVELOPING NEARING FROM THE N PLAINS STATES.
SOME OF THE COLDEST AIR OF THE SEASON WILL PUSH INTO THE UPPER GREAT
LAKES SATURDAY AFTERNOON ON. THERE CONTINUES TO BE SOME TIMING
ISSUES ON THE ORDER OF AROUND 6HRS...WHICH IS PRETTY MINOR THIS FAR
OUT IN THE FCST...AND A BLENDED SOLUTION LOOKS REASONABLE. 850MB
TEMPS OF -20 TO -30C WILL SETTLE IN SUNDAY AFTERNOON AS THE SFC LOW
EXITS AND THE MAIN 500MB TROUGH PUSHES ACROSS THE UPPER GREAT LAKES.
LOOK FOR FINE LES THAT WILL BE GOOD AT REDUCING VIS...ESPECIALLY IF
THE STRONGER NW WINDS OF THE 25/12Z ECMWF ARE CORRECT/.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1249 PM EST MON JAN 26 2015
IN THE WAKE OF STEADIER SNOW THAT AFFECTED KIWD THIS MORNING...
EXPECT MVFR CONDITIONS TO PREVAIL THIS AFTN. ANOTHER DISTURBANCE
TRACKING SSE WILL BRING A ROUND OF -SN TO KIWD/KCMX/KSAW LATE THIS
AFTN/EVENING. WHILE KIWD SHOULD REMAIN MVFR AS THE -SN
PASSES...STEADIER SNOW AT KCMX/KSAW WILL LIKELY DROP CONDITIONS
FROM VFR TO IFR. LINGERING MOISTURE BEHIND THE DISTURBANCE WILL
RESULT IN CONDITIONS FALLING TO IFR AT KIWD BY LATE EVENING. IFR/LOW
MVFR CIGS WILL LIKELY PERSIST AT ALL TERMINALS THRU TUE MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 AM EST MON JAN 26 2015
EXPECT S WINDS UP TO 20-25 KTS OVER MUCH OF LAKE SUPERIOR INTO THIS
AFTERNOON AS THE PRES GRADIENT TIGHTENS BETWEEN HI PRES DEPARTING TO
THE E AND A LO PRES MOVING SOUTHEAST TOWARD WESTERN LAKE SUPERIOR.
WINDS WILL DIMINISH LATER THIS AFTERNOON AND TONIGHT AS THE LO
WEAKENS AND SLIDES TO THE S. THEN RELATIVELY LIGHT WINDS UNDER 20
KTS WILL PREVAIL THRU WED AS A HI PRES RIDGE AND RATHER SLACK PRES
GRADIENT DOMINATES THE AREA. LOOK FOR STRONGER N WINDS UP TO 25 KTS
TO RETURN ON THU AS A LO PRES MOVES E THROUGH THE LOWER GREAT LAKES
AHEAD OF HI PRES BUILDING THROUGH CENTRAL CANADA...TIGHTENING THE
PRES GRADIENT AGAIN OVER LAKE SUPERIOR. THE INFLUX OF COLDER AIR AND
WAVES BUILT UP BY THE GUSTY WINDS WILL LIKELY BRING A RETURN OF
FREEZING SPRAY TO AT LEAST PORTIONS OF THE LAKE. THE CLOSER APPROACH
OF THE HI ON FRI WILL BRING A RETURN OF MORE TRANQUIL CONDITIONS.
&&
.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
637 AM EST MON JAN 26 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 416 AM EST MON JAN 26 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A NW FLOW ALOFT
OVER CENTRAL NAMERICA BTWN A HI AMPLITUDE RDG OVER THE W AND A DEEP
TROF OVER THE E. THERE ARE 2 SHRTWVS OF INTEREST EMBEDDED IN THE NW
FLOW...THE FIRST IS DIGGING SEWD INTO NW MN WHILE ANOTHER IS MOVING
SEWD THRU NRN MANITOBA/FAR NW ONTARIO. A FAIRLY VIGOROUS 998MB LO
OVER CENTRAL MANITOBA IS THE SFC REFLECTION OF THESE DISTURBANCES.
UPR MI IS UNDER THE SSW FLOW BTWN THIS LO AND SLOWLY RETREATING
ARCTIC HI PRES NEAR THE ONTARIO/QUEBEC BORDER. THE PRES GRADIENT IS
MUCH TIGHTER OVER MN CLOSER TO THE LO...AND SOME LIGHT SN IS NOTED
ON THE SFC OBS/RADAR COMPOSITES MOVING THRU NRN MN. ALTHOUGH NEARBY
RAOBS SHOW SOME MID LVL MSTR WITH 00Z H7 DEWPT DEPRESSIONS OF ONLY
2C AND 4C AT YPL AND INL RESPECTIVELY...THE RAOBS ALSO INDICATE SOME
LLVL DRY AIR LINGERS ACROSS THE AREA...WITH 00Z H85 DEWPT
DEPRESSIONS OF 26C AT MPX...22C AT GRB AND EVEN 13C AT INL/10C AT
YPL CLOSER TO THE SFC LO. SO THE OBSVD SN INTENSITY AND COVERAGE IS
NOT THAT GREAT DESPITE SOME FAIRLY STRONG ISENTROPIC ASCENT NOTED ON
THE 290K SFC /ABOUT H7/.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS/SN AMOUNTS
ASSOCIATED WITH THE 2 SHRTWVS NOTED ABOVE. SINCE THERE ARE 2
DISTURBANCES/SEPARATE AREAS OF DEEP LYR FORCING...THE INITIAL SHRTWV
IS TENDING TO TRACK FARTHER W DUE TO THE HI AMPLITUDE PATTERN AND
LARGER SCALE MSTR INFLOW WL REMAIN FAIRLY LIMITED...EXPECT SN
AMOUNTS TO BE SUB ADVY.
SHRTWV NOW MOVING INTO NW MN IS PROGGED TO DIG SSEWD THIS MRNG...
WITH AREA OF DEEP LYR QVECTOR CNVGC/SHARPER ISENTROPIC ASCENT ON THE
290K SFC IMPACTING MAINLY JUST THE WRN CWA THIS MRNG. THE SECOND
SHRTWV WL REACH FAR NW LK SUP LATE THIS AFTN...WITH AREA OF
DPVA/DEEP LYR QVECTOR CNVGC BUT WEAKER ISENTROPIC ASCENT INFLUENCING
MUCH OF THE CWA THIS AFTN/EVNG BEFORE FADING OVERNGT WITH APRCH OF
TRAILING SHRTWV RDG AXIS AND DNVA/DEEP LYR QVECTOR DVGC. WHILE THE
EXPECTED FORCING MAY JUSTIFY LIKELY TO CATEGORICAL POPS UNDER THE
BETTER FORCING...LIMITED MSTR INFLOW WL BE A MAJOR LIMITING FACTOR.
IN FACT THE H7 SPECIFIC HUMIDITY FCST UP TO 2 G/KG OVER THE W THIS
MRNG INTO EARLY AFTN IS FCST TO DIMINISH DURING THE EVENT. SO
DESPITE A FAVORABLE DEPTH/LOCATION OF THE DGZ CENTERED ARND 10K
FT...EXPECT SN TOTALS NOT MORE THAN 1 TO PERHAPS 3 INCHES...
HEAVIEST OVER THE W HALF BECAUSE THESE AREAS WL BE IMPACTED BY BOTH
SHRTWVS. SINCE SLOWLY BACKING LLVL FLOW WL ATTEMPT TO MAINTAIN FEED
OF NEAR SFC DRY AIR INTO THE E...FCST LOWER POPS/SN AMOUNTS IN THAT
AREA. IN FACT...THE FAR E MAY SEE LITTLE SN THRU TNGT. ONE CONCERN
FOR HEAVIER SN WL BE OVER THE SCENTRAL LATER THIS AFTN/EVNG DOWWIND
OF LK MI IN THE LLVL SLY FLOW AND WHEN DEEPER MSTR/FORCING
ASSOCIATED WITH 2ND SHRTWV WL ARRIVE IN THE PRESENCE OF H85 TEMPS /-
10 TO -12C/ SUFFICIENTLY COLD FOR SOME LK ENHANCEMENT.
HOWEVER...FAIRLY SHARP DIRECTIONAL SHEAR WITH BACKING LLVL SE FLOW
TURNING TO THE SSW AT H85 AND MAINTAINING A FEED OF NEAR SFC DRY AIR
MAY OFFSET THIS POTENTIAL. BUT OPTED TO MAINTAIN SOME HIER
CATEGORICAL POPS/QPF CENTERED NEAR ESCANABA TO ACCOUNT FOR THE
POTENTIAL LK ENHANCEMENT.
TEMPS TODAY SHOULD RECOVER INTO THE 20S OVER MOST OF THE CWA EXCEPT
OVER THE E...CLOSER TO SLOWLY RETREATING HI PRES/CORE OF COLDER AIR
AND WHERE H85 TEMPS ARE FCST TO RISE NO HIER THAN -12 TO -13C.
LINGERING CLDS THRU TNGT WL GREATLY LIMIT THE DIURNAL TEMP FALL. THE
COLDEST TEMPS AOB 10F WL ONCE AGAIN OCCUR OVER THE E.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 105 AM EST MON JAN 26 2015
WITH THE 500MB LOW AND THE AXIS OF THE 500MB TROUGH SHIFTED OVER THE
NEW ENGLAND STATES TUESDAY...THE RIDGE CURRENTLY OVER THE W HALF OF
THE NATION WILL BE ABLE TO SHIFT ACROSS THE CENTRAL PLAINS AND UPPER
GREAT LAKES TUESDAY INTO EARLY WEDNESDAY.
AT THE SFC...A RIDGE WILL BE ABLE TO SLIDE ACROSS LAKE SUPERIOR
TUESDAY /EXTENDING FROM MN UP THROUGH NEWFOUNDLAND/...WHICH WILL
LINGER INTO TUESDAY NIGHT AS THE MAIN AREA OF HIGH PRESSURE PUSHES
INTO THE OHIO VALLEY TUESDAY NIGHT INTO WEDNESDAY. THE RESULT WILL
BE A DRY PERIOD AT LEAST UNTIL MID DAY WEDNESDAY...ALTHOUGH THERE
MAY STILL BE SOME CLOUDS LINGERING/STUCK BELOW THE 850-900MB
SUBSIDENCE INVERSION. TRICKY CLOUD COVER FCST FOR THIS PERIOD.
WEDNESDAY LOOK TO BE THE LAST WARM DAY IN A WHILE...WITH
TEMPERATURES NEAR FREEZING. 850MB TEMPS ON S FLOW WILL RISE TO -1 TO
-4C THROUGH THE DAYTIME HOURS AS THICKER CLOUDS INVADE FROM THE NW.
AN ELONGATED AREA OF LOW PRESSURE OVER THE N AND CENTRAL PLAINS
WEDNESDAY MORNING WILL EDGE E ACROSS IL AND IN THURSDAY
MORNING...AND OFF TO THE LOWER GREAT LAKES AND OFF THE MID ATLANTIC
STATES FRIDAY. THIS WILL BRING A TROUGH ACROSS OUR AREA WEDNESDAY
NIGHT THROUGH THURSDAY EVENING...WHICH WILL BE ENHANCED BY THE
SUPPRESSION OF THE 500MB RIDGE WEDNESDAY EVENING AND THURSDAY. LOOK
FOR A WIDESPREAD 2-5IN OF SNOW WITH SLR VALUES AROUND 15:1. EXPECT
THE HIGHER VALUES OVER THE N HALF OF UPPER MI AS IT WILL LIKELY TAKE
UNTIL LATE AFTERNOON/EARLY EVENING FOR SNOW TO BEGIN S CENTRAL. WILL
NOT GO QUITE AS QUICK WITH THE INVADING PRECIP AS THE 00Z NAM...BUT
A BLENDED SOLUTION SOUNDS REASONABLE. A WINTER WX ADVISORY MAY BE
NEEDED IF THE 2-5IN CAN FALL IN A 12HR PERIOD. WILL CONTINUE TO LOOK
INTO THIS FOR POSSIBLE POSTING OF HEADLINES ON TUESDAY...AND
HIGHLIGHT THE POTENTIAL FOR LIGHT TO MODERATE SNOW IN THE HWO.
N FLOW BEHIND THE EXITING SFC TROUGH THURSDAY AFTERNOON WILL BE THE
START OF OUR COOL DOWN...WITH 850MB TEMPS FALLING TO -8 TO -10C.
WHILE NOT QUITE OPTIMAL FOR LAKE EFFECT YET...SOME LAKE ENHANCEMENT
WILL BE LIKELY ALONG THE UPSLOPE N SNOWBELTS ALONG LAKE SUPERIOR
THURSDAY AS THE SFC LOW EXITS TO THE LOWER GREAT LAKES/PENNSYLVANIA
FRIDAY EVENING.
DESPITE SFC-500MB RIDGING ON FRIDAY...A FEW LINGERING LES WILL
REMAIN ALONG THE LAKE SUPERIOR SHORELINES. DON/T EXPECT MUCH IN THE
WAY OF ACCUMULATIONS AS THE MOISTURE IS AGAIN TRAPPED BELOW 850MB.
BUT WILL THE MOISTURE LAYER IN THE DGZ /850MB TEMPS OF -15 TO
-17C/...SOME LIGHT ACCUMULATIONS WILL BE POSSIBLE.
SLIGHTLY WARMER AIR WILL PUSH IN THROUGH EARLY SATURDAY MORNING AS
THE SFC RIDGE EXITS TO THE LOWER GREAT LAKES...AND IN ADVANCE OF LOW
PRESSURE DEVELOPING NEARING FROM THE N PLAINS STATES.
SOME OF THE COLDEST AIR OF THE SEASON WILL PUSH INTO THE UPPER GREAT
LAKES SATURDAY AFTERNOON ON. THERE CONTINUES TO BE SOME TIMING
ISSUES ON THE ORDER OF AROUND 6HRS...WHICH IS PRETTY MINOR THIS FAR
OUT IN THE FCST...AND A BLENDED SOLUTION LOOKS REASONABLE. 850MB
TEMPS OF -20 TO -30C WILL SETTLE IN SUNDAY AFTERNOON AS THE SFC LOW
EXITS AND THE MAIN 500MB TROUGH PUSHES ACROSS THE UPPER GREAT LAKES.
LOOK FOR FINE LES THAT WILL BE GOOD AT REDUCING VIS...ESPECIALLY IF
THE STRONGER NW WINDS OF THE 25/12Z ECMWF ARE CORRECT/.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 636 AM EST MON JAN 26 2015
SOME -SN ASSOCIATED WITH A CLIPPER TYPE LO MOVING FM NRN MN SSE INTO
WI TNGT WL IMPACT THE TAF SITES THIS FCST PERIOD. STEADIER SN WL
FALL AT IWD THIS MRNG...REDUCING VSBY INTO THE IFR RANGE UNTIL THE
SN SHIFTS AWAY THIS AFTN AND CONDITIONS REBOUND TO MVFR. AS THE AREA
OF SN DRIFTS ONLY SLOWLY TO THE E INTO FAIRLY DRY LLVL AIR
ASSOCIATED WITH DEPARTING HI PRES IN SE CANADA...EXPECT VFR
CONDITIONS AT CMX AND SAW TO DETERIORATE TO MVFR AND THEN IFR BY
LATE THIS AFTN. ALTHOUGH THE STEADIER SN WL EXIT THE AREA
TNGT...LINGERING LLVL MSTR WL RESULT IN LO END MVFR/HI IFR
CONDITIONS. THE LOCATION MOST LIKELY TO SEE IFR CONDITIONS WL BE SAW
WITH AN UPSLOPE SE WIND OFF LK MI.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 AM EST MON JAN 26 2015
EXPECT S WINDS UP TO 20-25 KTS OVER MUCH OF LAKE SUPERIOR INTO THIS
AFTERNOON AS THE PRES GRADIENT TIGHTENS BETWEEN HI PRES DEPARTING TO
THE E AND A LO PRES MOVING SOUTHEAST TOWARD WESTERN LAKE SUPERIOR.
WINDS WILL DIMINISH LATER THIS AFTERNOON AND TONIGHT AS THE LO
WEAKENS AND SLIDES TO THE S. THEN RELATIVELY LIGHT WINDS UNDER 20
KTS WILL PREVAIL THRU WED AS A HI PRES RIDGE AND RATHER SLACK PRES
GRADIENT DOMINATES THE AREA. LOOK FOR STRONGER N WINDS UP TO 25 KTS
TO RETURN ON THU AS A LO PRES MOVES E THROUGH THE LOWER GREAT LAKES
AHEAD OF HI PRES BUILDING THROUGH CENTRAL CANADA...TIGHTENING THE
PRES GRADIENT AGAIN OVER LAKE SUPERIOR. THE INFLUX OF COLDER AIR AND
WAVES BUILT UP BY THE GUSTY WINDS WILL LIKELY BRING A RETURN OF
FREEZING SPRAY TO AT LEAST PORTIONS OF THE LAKE. THE CLOSER APPROACH
OF THE HI ON FRI WILL BRING A RETURN OF MORE TRANQUIL CONDITIONS.
&&
.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
416 AM EST MON JAN 26 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 416 AM EST MON JAN 26 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A NW FLOW ALOFT
OVER CENTRAL NAMERICA BTWN A HI AMPLITUDE RDG OVER THE W AND A DEEP
TROF OVER THE E. THERE ARE 2 SHRTWVS OF INTEREST EMBEDDED IN THE NW
FLOW...THE FIRST IS DIGGING SEWD INTO NW MN WHILE ANOTHER IS MOVING
SEWD THRU NRN MANITOBA/FAR NW ONTARIO. A FAIRLY VIGOROUS 998MB LO
OVER CENTRAL MANITOBA IS THE SFC REFLECTION OF THESE DISTURBANCES.
UPR MI IS UNDER THE SSW FLOW BTWN THIS LO AND SLOWLY RETREATING
ARCTIC HI PRES NEAR THE ONTARIO/QUEBEC BORDER. THE PRES GRADIENT IS
MUCH TIGHTER OVER MN CLOSER TO THE LO...AND SOME LIGHT SN IS NOTED
ON THE SFC OBS/RADAR COMPOSITES MOVING THRU NRN MN. ALTHOUGH NEARBY
RAOBS SHOW SOME MID LVL MSTR WITH 00Z H7 DEWPT DEPRESSIONS OF ONLY
2C AND 4C AT YPL AND INL RESPECTIVELY...THE RAOBS ALSO INDICATE SOME
LLVL DRY AIR LINGERS ACROSS THE AREA...WITH 00Z H85 DEWPT
DEPRESSIONS OF 26C AT MPX...22C AT GRB AND EVEN 13C AT INL/10C AT
YPL CLOSER TO THE SFC LO. SO THE OBSVD SN INTENSITY AND COVERAGE IS
NOT THAT GREAT DESPITE SOME FAIRLY STRONG ISENTROPIC ASCENT NOTED ON
THE 290K SFC /ABOUT H7/.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS/SN AMOUNTS
ASSOCIATED WITH THE 2 SHRTWVS NOTED ABOVE. SINCE THERE ARE 2
DISTURBANCES/SEPARATE AREAS OF DEEP LYR FORCING...THE INITIAL SHRTWV
IS TENDING TO TRACK FARTHER W DUE TO THE HI AMPLITUDE PATTERN AND
LARGER SCALE MSTR INFLOW WL REMAIN FAIRLY LIMITED...EXPECT SN
AMOUNTS TO BE SUB ADVY.
SHRTWV NOW MOVING INTO NW MN IS PROGGED TO DIG SSEWD THIS MRNG...
WITH AREA OF DEEP LYR QVECTOR CNVGC/SHARPER ISENTROPIC ASCENT ON THE
290K SFC IMPACTING MAINLY JUST THE WRN CWA THIS MRNG. THE SECOND
SHRTWV WL REACH FAR NW LK SUP LATE THIS AFTN...WITH AREA OF
DPVA/DEEP LYR QVECTOR CNVGC BUT WEAKER ISENTROPIC ASCENT INFLUENCING
MUCH OF THE CWA THIS AFTN/EVNG BEFORE FADING OVERNGT WITH APRCH OF
TRAILING SHRTWV RDG AXIS AND DNVA/DEEP LYR QVECTOR DVGC. WHILE THE
EXPECTED FORCING MAY JUSTIFY LIKELY TO CATEGORICAL POPS UNDER THE
BETTER FORCING...LIMITED MSTR INFLOW WL BE A MAJOR LIMITING FACTOR.
IN FACT THE H7 SPECIFIC HUMIDITY FCST UP TO 2 G/KG OVER THE W THIS
MRNG INTO EARLY AFTN IS FCST TO DIMINISH DURING THE EVENT. SO
DESPITE A FAVORABLE DEPTH/LOCATION OF THE DGZ CENTERED ARND 10K
FT...EXPECT SN TOTALS NOT MORE THAN 1 TO PERHAPS 3 INCHES...
HEAVIEST OVER THE W HALF BECAUSE THESE AREAS WL BE IMPACTED BY BOTH
SHRTWVS. SINCE SLOWLY BACKING LLVL FLOW WL ATTEMPT TO MAINTAIN FEED
OF NEAR SFC DRY AIR INTO THE E...FCST LOWER POPS/SN AMOUNTS IN THAT
AREA. IN FACT...THE FAR E MAY SEE LITTLE SN THRU TNGT. ONE CONCERN
FOR HEAVIER SN WL BE OVER THE SCENTRAL LATER THIS AFTN/EVNG DOWWIND
OF LK MI IN THE LLVL SLY FLOW AND WHEN DEEPER MSTR/FORCING
ASSOCIATED WITH 2ND SHRTWV WL ARRIVE IN THE PRESENCE OF H85 TEMPS /-
10 TO -12C/ SUFFICIENTLY COLD FOR SOME LK ENHANCEMENT.
HOWEVER...FAIRLY SHARP DIRECTIONAL SHEAR WITH BACKING LLVL SE FLOW
TURNING TO THE SSW AT H85 AND MAINTAINING A FEED OF NEAR SFC DRY AIR
MAY OFFSET THIS POTENTIAL. BUT OPTED TO MAINTAIN SOME HIER
CATEGORICAL POPS/QPF CENTERED NEAR ESCANABA TO ACCOUNT FOR THE
POTENTIAL LK ENHANCEMENT.
TEMPS TODAY SHOULD RECOVER INTO THE 20S OVER MOST OF THE CWA EXCEPT
OVER THE E...CLOSER TO SLOWLY RETREATING HI PRES/CORE OF COLDER AIR
AND WHERE H85 TEMPS ARE FCST TO RISE NO HIER THAN -12 TO -13C.
LINGERING CLDS THRU TNGT WL GREATLY LIMIT THE DIURNAL TEMP FALL. THE
COLDEST TEMPS AOB 10F WL ONCE AGAIN OCCUR OVER THE E.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 105 AM EST MON JAN 26 2015
WITH THE 500MB LOW AND THE AXIS OF THE 500MB TROUGH SHIFTED OVER THE
NEW ENGLAND STATES TUESDAY...THE RIDGE CURRENTLY OVER THE W HALF OF
THE NATION WILL BE ABLE TO SHIFT ACROSS THE CENTRAL PLAINS AND UPPER
GREAT LAKES TUESDAY INTO EARLY WEDNESDAY.
AT THE SFC...A RIDGE WILL BE ABLE TO SLIDE ACROSS LAKE SUPERIOR
TUESDAY /EXTENDING FROM MN UP THROUGH NEWFOUNDLAND/...WHICH WILL
LINGER INTO TUESDAY NIGHT AS THE MAIN AREA OF HIGH PRESSURE PUSHES
INTO THE OHIO VALLEY TUESDAY NIGHT INTO WEDNESDAY. THE RESULT WILL
BE A DRY PERIOD AT LEAST UNTIL MID DAY WEDNESDAY...ALTHOUGH THERE
MAY STILL BE SOME CLOUDS LINGERING/STUCK BELOW THE 850-900MB
SUBSIDENCE INVERSION. TRICKY CLOUD COVER FCST FOR THIS PERIOD.
WEDNESDAY LOOK TO BE THE LAST WARM DAY IN A WHILE...WITH
TEMPERATURES NEAR FREEZING. 850MB TEMPS ON S FLOW WILL RISE TO -1 TO
-4C THROUGH THE DAYTIME HOURS AS THICKER CLOUDS INVADE FROM THE NW.
AN ELONGATED AREA OF LOW PRESSURE OVER THE N AND CENTRAL PLAINS
WEDNESDAY MORNING WILL EDGE E ACROSS IL AND IN THURSDAY
MORNING...AND OFF TO THE LOWER GREAT LAKES AND OFF THE MID ATLANTIC
STATES FRIDAY. THIS WILL BRING A TROUGH ACROSS OUR AREA WEDNESDAY
NIGHT THROUGH THURSDAY EVENING...WHICH WILL BE ENHANCED BY THE
SUPPRESSION OF THE 500MB RIDGE WEDNESDAY EVENING AND THURSDAY. LOOK
FOR A WIDESPREAD 2-5IN OF SNOW WITH SLR VALUES AROUND 15:1. EXPECT
THE HIGHER VALUES OVER THE N HALF OF UPPER MI AS IT WILL LIKELY TAKE
UNTIL LATE AFTERNOON/EARLY EVENING FOR SNOW TO BEGIN S CENTRAL. WILL
NOT GO QUITE AS QUICK WITH THE INVADING PRECIP AS THE 00Z NAM...BUT
A BLENDED SOLUTION SOUNDS REASONABLE. A WINTER WX ADVISORY MAY BE
NEEDED IF THE 2-5IN CAN FALL IN A 12HR PERIOD. WILL CONTINUE TO LOOK
INTO THIS FOR POSSIBLE POSTING OF HEADLINES ON TUESDAY...AND
HIGHLIGHT THE POTENTIAL FOR LIGHT TO MODERATE SNOW IN THE HWO.
N FLOW BEHIND THE EXITING SFC TROUGH THURSDAY AFTERNOON WILL BE THE
START OF OUR COOL DOWN...WITH 850MB TEMPS FALLING TO -8 TO -10C.
WHILE NOT QUITE OPTIMAL FOR LAKE EFFECT YET...SOME LAKE ENHANCEMENT
WILL BE LIKELY ALONG THE UPSLOPE N SNOWBELTS ALONG LAKE SUPERIOR
THURSDAY AS THE SFC LOW EXITS TO THE LOWER GREAT LAKES/PENNSYLVANIA
FRIDAY EVENING.
DESPITE SFC-500MB RIDGING ON FRIDAY...A FEW LINGERING LES WILL
REMAIN ALONG THE LAKE SUPERIOR SHORELINES. DON/T EXPECT MUCH IN THE
WAY OF ACCUMULATIONS AS THE MOISTURE IS AGAIN TRAPPED BELOW 850MB.
BUT WILL THE MOISTURE LAYER IN THE DGZ /850MB TEMPS OF -15 TO
-17C/...SOME LIGHT ACCUMULATIONS WILL BE POSSIBLE.
SLIGHTLY WARMER AIR WILL PUSH IN THROUGH EARLY SATURDAY MORNING AS
THE SFC RIDGE EXITS TO THE LOWER GREAT LAKES...AND IN ADVANCE OF LOW
PRESSURE DEVELOPING NEARING FROM THE N PLAINS STATES.
SOME OF THE COLDEST AIR OF THE SEASON WILL PUSH INTO THE UPPER GREAT
LAKES SATURDAY AFTERNOON ON. THERE CONTINUES TO BE SOME TIMING
ISSUES ON THE ORDER OF AROUND 6HRS...WHICH IS PRETTY MINOR THIS FAR
OUT IN THE FCST...AND A BLENDED SOLUTION LOOKS REASONABLE. 850MB
TEMPS OF -20 TO -30C WILL SETTLE IN SUNDAY AFTERNOON AS THE SFC LOW
EXITS AND THE MAIN 500MB TROUGH PUSHES ACROSS THE UPPER GREAT LAKES.
LOOK FOR FINE LES THAT WILL BE GOOD AT REDUCING VIS...ESPECIALLY IF
THE STRONGER NW WINDS OF THE 25/12Z ECMWF ARE CORRECT/.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1227 AM EST MON JAN 26 2015
A CLIPPER SYSTEM DROPPING SE THROUGH SRN MANITOBA WILL MOVE ACROSS
THE AREA OVERNIGHT INTO MONDAY. VFR CONDITIONS WILL GIVE WAY TO
GRADUALLY LOWERING CEILINGS AHEAD OF THE SYSTEM AND THEN SNOW MOVING
IN AT KIWD JUST AFT 12Z...AT KCMX LATE MON MORNING AND THEN AT KSAW
EARLY MON AFTERNOON. EXPECT IFR VSBYS TO AFFECT KIWD FROM MON MORNING
INTO EARLY AFTERNOON AND THEN IFR VBSYS WILL SPREAD INTO KCMX AND
KSAW LATE MON AFTERNOON INTO MON EVENING AS MOISTURE DEEPENS OVER THE
NW AND NCNTRL PORTION OF THE U.P. SOME IMPROVEMENT IN VSBY IS
EXPECTED AT KIWD LATE MONDAY AS BEST MOISTURE DEPARTS AND SNOW TAPERS
OFF.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 AM EST MON JAN 26 2015
EXPECT S WINDS UP TO 20-25 KTS OVER MUCH OF LAKE SUPERIOR INTO THIS
AFTERNOON AS THE PRES GRADIENT TIGHTENS BETWEEN HI PRES DEPARTING TO
THE E AND A LO PRES MOVING SOUTHEAST TOWARD WESTERN LAKE SUPERIOR.
WINDS WILL DIMINISH LATER THIS AFTERNOON AND TONIGHT AS THE LO
WEAKENS AND SLIDES TO THE S. THEN RELATIVELY LIGHT WINDS UNDER 20
KTS WILL PREVAIL THRU WED AS A HI PRES RIDGE AND RATHER SLACK PRES
GRADIENT DOMINATES THE AREA. LOOK FOR STRONGER N WINDS UP TO 25 KTS
TO RETURN ON THU AS A LO PRES MOVES E THROUGH THE LOWER GREAT LAKES
AHEAD OF HI PRES BUILDING THROUGH CENTRAL CANADA...TIGHTENING THE
PRES GRADIENT AGAIN OVER LAKE SUPERIOR. THE INFLUX OF COLDER AIR AND
WAVES BUILT UP BY THE GUSTY WINDS WILL LIKELY BRING A RETURN OF
FREEZING SPRAY TO AT LEAST PORTIONS OF THE LAKE. THE CLOSER APPROACH
OF THE HI ON FRI WILL BRING A RETURN OF MORE TRANQUIL CONDITIONS.
&&
.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 TWIN CITIES/CHANHASSEN MN
345 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 SANDWHICHED 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 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1154 AM CST MON JAN 26 2015
WARM FRONTAL BOUNDARY ORIENTED N-S HAS REACHED THE MN/WI
BORDER...WITH CLEAR SKIES AND WARM TEMPERATURES WEST OF IT...AND
COLD TEMPS/-SN/-FZDZ EAST AND NORTH OF IT UNDER LOW STRATUS.
EXPECTING THIS FRONT TO BE QUASI-STATIONARY SO LITTLE MOVEMENT IN
THE STRATUS IS EXPECTED FOR THE REMAINDER OF THE DAY. WESTERN MN
WILL REMAIN MOSTLY CLEAR AND EXPECT VFR FOR THE ENTIRE PERIOD. A
MUCH MORE COMPLICATED SCENARIO IN EASTERN MN...NEAR THE BOUNDARY
ITSELF. 925 RH FIELDS INDICATE THE POTENTIAL FOR LOW STRATUS TO
GET STUCK UNDER AN INVERSION TONIGHT...AS THE CLOUD COVER IN
NORTHERN MN ADVECTS SOUTHWARD THROUGH THE REMAINDER OF THE DAY.
STILL...NOT CONFIDENT IN THESE HIGH RH LEVELS IN THE LOWER LEVELS
ACTUALLY TRANSLATING TO LOW CIGS. SIGNIFICANT DRYING JUST ABOVE
THIS LEVEL /AND THE INVERSION/ MAKES IT A TOUGH CALL FROM LATE
TONIGHT THROUGH TUESDAY MORNING. LEANED TO THE OPTIMISTIC SIDE AND
SCATTERED OUT THE LOW CEILINGS LATE TONIGHT...BUT BE AWARE THERE
IS POTENTIAL THE LOW CIGS COULD STICK AROUND ALL NIGHT.
KMSP...VFR INITIALLY AS WE LINGER NEAR THE EDGE OF THE CLOUD DECK
TO THE NORTH AND EAST. THINKING WE`LL RIDE THE EDGE FOR MUCH OF
THE LATE AFTERNOON AND EVENING. WENT SCT AFTER 07Z...BUT LOW
CONFIDENCE IN THIS AND WILL NEED TO CONTINUE EVALUATING CIG
POTENTIAL FOR THE OVERNIGHT PERIOD.
/OUTLOOK FOR KMSP/
TUE...VFR. WIND LIGHT/VARIABLE.
WED...VFR. CHC MVFR. WIND SE 10 KT.
THU...CHC MVFR/-SN. WIND NW 10-20 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR WIZ015-
016-025>028.
&&
$$
SHORT TERM...SPD
LONG TERM...JRB
AVIATION...SPD
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
538 PM CST Tue Jan 27 2015
.SHORT TERM: (Through Late Tonight)
Issued at 400 PM CST Tue Jan 27 2015
Surface ridge extending from WI southwest into northern MO will
strengthen and move southeastward into the Ohio Valley region by 12Z
Wednesday. Persistent low level cloud cover extends across eastern
IA and much of IL this afternoon with some diurnally driven
cloudiness across eastern MO. Much of the cloud cover over eastern
MO should dissipate early this evening. The models try to slowly
dissipate and advect eastward the more solid cloud cover across
eastern IA and IL tonight. While this is possible due to at least
weak subsidence across the area, would not be surprised if this
cloud cover remains trapped under the inversion and actually
retrogrades some westward tonight as the surface/boundary layer wind
veers around to an easterly direction this evening. If this low
level cloud cover remains through the night the MOS minimum
temperature guidance may be a little too cool across the IL counties
of our forecast area. Lows tonight across the western portion of
the forecast area will be warmer despite less cloud cover due to
increasing low level warm air advection on the nose of a
southwesterly low level jet.
GKS
.LONG TERM: (Wednesday through Next Tuesday)
Issued at 400 PM CST Tue Jan 27 2015
(Wednesday-Friday)
12z guidance continues to support thinking that a strong but brief
warmup will occur tomorrow, followed by a cooling trend
that should send temps to below average levels by the end of the
work week. Have maintained current forecast highs for Wednesday,
which is several degrees warmer than warmest GFS MAV. In spite of
the very strong inversion that is forecast to limit mixing still
think warmer is the way to go, as guidance hasn`t been robust enough
the past few times we`ve had strong warming. I`m also uncertain how
much cloudiness there will be; worse case for warming would be that
this afternoon`s low clouds manage to hang around in the morning,
but increasing southerly surface winds should advect them back out
of the area for the afternoon.
Cold front will sweep through the region Wednesday night, with the
resultant cold advection only allowing a minimal daytime rebound
during the day on Thursday. I have also continued some slight
chance PoPs late Wednesday night and into Thursday morning as
shortwave drops into the mid-Mississippi Valley, but moisture
certainly looks scant at this time.
The chunk of cold air that pushes into the area on Thursday should
continue to exert its influence on Friday, with highs about a
category lower than those on Thursday.
(Saturday-Tuesday)
Over the past few days models have come into much better agreement
for this upcoming weekend, with upper low cutting off over the
southwestern U.S. while fairly active westerlies continue from the
Pacific NW, through the Mississippi Valley, into the east coast.
All medium range guidance now supports the idea that broad
overrunning will develop in the wake of the cold surface ridge on
Saturday, which should lead to at least a chance of precip over much
of the area. However, a strong shortwave in the westerlies will add
additional large scale lift Saturday night and into Sunday, and have
upped PoPs a bit more during this time.
While precip is looking more promising, still lots of unknowns about
ptype. 850mb temps are genenerally below 0C and certainly on
Saturday evaporative cooling should try to cool the lower levels of
the AMS enough to support snow. However, forecast soundings are
also suggesting low level temp profile will become isothermal at
around 0C on Saturday night and Sunday, which suggests ptype go be
either liquid or frozen. I have leaned ptype a bit more towards
snow, but still kept some mention of a mix because of the above
thermal profile.
A large chunk of very cold air will drop into the region behind the
weekend system, and by the start of the new work week we will likely
be reminded that winter is certainly not over. Have stayed with
initialization guidance for highs on Monday...generally ranging from
the lower 20s to the lower 30s.
Truett
&&
.AVIATION: (For the 00z TAFs through 00z Wednesday Evening)
Issued at 532 PM CST Tue Jan 27 2015
Main concern for the overnight hours will be on stratus in
Illinois. Dissipation has occurred over the past several hours on
the western flank mainly due to diurnal effects. Will have to
watch this area of stratus overnight as it is possible MVFR
ceilings advect back southwestward into KUIN and the St. Louis
metro TAF sites. RAP 925-950 hPa winds...albeit quite light...do
suggest this may be possible as initially northerly winds in the
aforementioned layer veer to the east and then eventually
southeast overnight tonight. Otherwise...quiet and tranquil
conditions are expected as sfc ridge of high pressure dominates
the area with winds staying light overnight. By
tomorrow/Wednesday...pressure gradient strengthens with winds
becoming more southerly at the surface with wind gusts up to
around 25 knots.
Specifics for KSTL:
Main concern for the overnight hours will be on stratus deck
currently residing just east of the terminal. Dissipation has
occurred over the past several hours on the western flank mainly
due to diurnal effects...but will have to watch this area of
stratus overnight as it is possible MVFR ceilings advect back
southwestward into Lambert Field. RAP 925-950 hPa winds...albeit quite
light...do suggest this may be possible as initially northerly
winds in the aforementioned layer veer to the east and then
eventually southeast overnight tonight. Otherwise...quiet and
tranquil conditions are expected as sfc ridge of high pressure
dominates the area with winds staying light overnight. By
tomorrow/Wednesday...pressure gradient strengthens with winds
becoming more southerly at the surface with wind gusts up to
around 25 knots.
Gosselin
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1141 PM CST Sun Jan 25 2015
.SHORT TERM: (Through Late Tonight)
Issued at 323 PM CST Sun Jan 25 2015
Precip over the CWA should be winding down over the next few hours
as upper level impulse works its way SE into the Ohio Valley.
Deformation zone that was so well defined this morning over IA and
n IL certainly falling apart as the afternoon progresses, and have
used a combination of regional radar and HRRR for PoP/weather
trends heading into the early evening. It would appear that the NW
edge of the precip (now all snow) will be near a KCOU-KILX line
by 00z, with the precip dropping southeast and exiting
SE sections of the CWA no later than 06z. Surface obs trends this
afternoon indicate that rain begins mixing with snow @ 36-37 and
is all snow at 34 or colder, and will use this for ptypes for the
rest of the afternoon and into the early evening. Given warm
ground and the light intensity of the precip once it goes to all
snow, accumulations should continue to be very minor.
Other question for tonight is how much clearing will occur as the
storm exits and a narrow ridge of high pressure works into the
region. Over the last few hours have seen a wedge of clearing
wrapping around the surface low from S WI into NE IA. Some of this
clearing may reach our area, but there is also a lot of additional
low cloud to our north that will advect our way as well, so for
now have only gone with partial clearing during the late evening
and overnight hours.
Truett
.LONG TERM: (Monday through Next Sunday)
Issued at 323 PM CST Sun Jan 25 2015
(Monday-Wednesday)
Overall, going forecast heading into midweek still looks pretty
good, so this package will include generally minor adjustments and
tweaks to these trends.
Fast moving shortwave in northwest flow will zip into the region on
Monday, with WAA in advance of this feature rapidly shutting down
the CAA occuring overnight in the wake of today`s clipper. 12z
synoptic runs are suggesting a fairly strong N-S warm front will be
located near or just west of STL by late Monday afternoon and have
attempted to reflect this in max temp forecast, allowing highs to
rebound into the middle 50s over mid MO while keeping highs in the
30s over our S IL counties. This temp trend also seems to be
supported by the model RH progs which suggest a fairly thick mid
deck sweeping from W to E across the area in the zone of WAA during
the day, with the most clouds over our eastern counties during the
afternoon. Some 12z guidance is even trying to kick out some
light QPF near and east of the Mississippi River in the zone of
strongest WAA. Have continued dry forecast for now, but will need
to keep an eye on this as there has been some very subtle suggestions
of this for several days.
The cold air advection behind Monday`s shortwave will try to dip
into the area Monday night, but with the longwave trof working into
the east coast during this time the main thrust of this cooler air
will be east of our area. Model consensus of thermal profiles over
the region support highs in the 40s over most of the CWA by Tuesday
as weak surface ridge drops into the Mississippi Valley.
Warmup still appears to be on schedule for Wednesday, and main
question is how much of the warming will be able to translate to the
surface. Forecast soundings are suggesting a large inversion, with
low level mixing up to 900-950mb. Surface/low level winds...while
strong...are going to primarily be southerly rather than the
southwest direction that normally gives us our biggest warmups.
Also some doubt to how much cloud cover there will be, as GFS
suggests some mid clouds working into the area during the afternoon
while NAM suggests lots of sunshine. Due to the above uncertainty
will keep highs about where they are now...ranging from the mid 40s
in our far eastern counties to near 60 in the far western tip of our
CWA.
(Thursday-Sunday)
Shortwave that works across the region Wednesday night and early
Thursday appears to be the first of several chunks of energy that
will be deepening long wave trof over the eastern U.S. heading into
the weekend, while cutoff low forms over the southwestern U.S.
Medium range solutions are in very broad agreement in developing
this split flow pattern, and in general this should mean temps
trending back towards more wintry levels after the mid-week warmup.
Will continue some slight chance PoPs on Wednesday night/Thursday
for eastern parts of the FA in advance of aforementioned shortwave,
with slight chance PoPs also continuing for parts of the FA on
Saturday and Saturday night as there is agreement in the medium
range models that WAA, a bit of shortwave energy, and a frontal
boundary will be passing through the area at that time.
Guidance is in reasonable agreement with their thermal profiles
through Saturday, but much like yesterday the operational ECMWF
continues to be deepest with the upper trof and much colder than the
GFS by the end of the period (it`s intesting to note that last
nights ECMWF-based MOS had over a 40 degree difference between the
warm and cold members for Sunday`s highs (58 vs 16). For now, will
lean towards MOS averages for temp trends on Sunday...which will be
in the 30s. This seems to be a reasonable compromise at this point,
with additional adjustments occurring as specific trends become less
muddled.
Truett
&&
.AVIATION: (For the 06z TAFs through 06z Monday Night)
Issued at 1132 PM CST Sun Jan 25 2015
Lingering MVFR SC deck to persist across most of taf sites through
mid morning before scattering out. There is a hole in the mvfr
deck that has made its way into KUIN but should see that fill back
in by 08z Monday. Then next frontal boundary to move through and lower
cigs back down to mvfr for tafs along and east of Mississippi
river, while KCOU to remain vfr. As for winds, to persist from the
north, then back to the southwest to south ahead of next front.
Frontal boundary to move through KCOU by 22z Monday, KUIN by 23z
Monday and metro area by 01z Tuesday. It will be a dry frontal
passage with winds veering to the northwest.
Specifics for KSTL:
Lingering MVFR SC deck to persist across metro area through midday
before lifting and scattering out. Then next frontal boundary to
move through and lower cigs back down to mvfr by 01z Tuesday. As
for winds, to persist from the north, then back to the south ahead
of next front. Frontal passage will be a dry one with winds
veering to the northwest.
Byrd
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
905 AM PST MON JAN 26 2015
.SYNOPSIS...INCREASING CLOUDS EXPECTED TODAY WITH RAIN MOVING INTO
PARTS OF NORTHWEST ARIZONA AND THE MOJAVE DESERT BY THE AFTERNOON.
RAIN CHANCES WILL EXPAND NORTHWARD TONIGHT AND LIFT INTO THE GREAT
BASIN TUESDAY. IMPROVING CONDITIONS ARE EXPECTED TUESDAY AFTERNOON
THROUGH WEDNESDAY BEFORE THE POSSIBILITY OF MORE UNSETTLED WEATHER
RETURNS LATE IN THE WEEK.
&&
.UPDATE...RADAR DETECTING NARROW LINE OF LIGHT RAIN RUNNING FROM
NEAR TWENTYNINE PALMS CA SOUTHEAST TOWARD YUMA AZ. BAND ASSOCIATED
WITH JETSTREAK ACROSS SOUTHERN CALIFORNIA THIS MORNING. SEE A REPORT
OF NEARLY TWO TENTH OF AN INCH FROM A STATION NORTH OF YUMA,
OTHERWISE RAIN AMOUNTS RANGE FROM A FEW HUNDREDTHS OF AN INCH DOWN
TO A TRACE. 12Z NAM/GFS PLUS THE 15Z HRRR SHIFT THIS BAND NORTHWEST
ACROSS WESTERN SAN BERNARDINO COUNTY THIS AFTERNOON WITH ADDITIONAL
BANDS DEVELOPING ACROSS EASTERN SAN BERNARDINO COUNTY AND SOUTHERN
MOHAVE COUNTY. UPDATED EARLIER TO INCREASE POPS FOR SOUTHERN SAN
BERNARDINO COUNTY AND THE AREA AROUND LAKE HAVASU CITY THIS
AFTERNOON.
A FEW 12Z MODELS NOW SUGGESTING RAIN BAND WILL BE MORE BROKEN AS IT
LIFTS NORTH INTO SOUTHERN NEVADA TONIGHT. THIS EVENT NOW LOOKING
MORE OF A HIGH POP, LOW QPF EVENT FOR THE LAS VEGAS VALLEY. WILL
ADDRESS AND POTENTIAL CHANGES IN THE AFTERNOON PACKAGE.
&&
.PREV DISCUSSION...326 AM PST MON JAN 26 2015
.SHORT TERM...THROUGH TUESDAY NIGHT.
FAIRLY EXTENSIVE CLOUD SHIELD WRAPPING AROUND THE BAJA LOW IS NOW
BEGINNING TO NUDGE INTO OUR SOUTHERN BORDER AND WILL CONTINUE TO
INVADE OUR SKIES THROUGH THE EARLY MORNING HOURS. FOR THE MOST PART
THE FORECAST REMAINS ON TRACK WITH SOME TENDENCY NOTED FOR THE
MODELS TO TAKE THE HEAVIEST QPF UP THROUGH SAN BERNARDINO COUNTY AND
INTO INYO COUNTY WITH LESSER AMOUNTS FURTHER EAST. REGARDLESS...I
STILL ANTICIPATE A FAIRLY WIDESPREAD RAIN EVENT FOR OUR AREA.
AS FOR THE DETAILS...RAIN WILL BEGIN TO BREAK OUT ACROSS SOUTHERN
SAN BERNARDINO COUNTY BY LATE MORNING OR EARLY AFTERNOON. THE LATEST
HRRR GUIDANCE HAS SOME LIGHT PRECIPITATION BREAKING OUT ROUGHLY
SOUTH OF INTERSTATE 40 BY NOON. THIS PRECIP BAND WILL CONTINUE TO
EXPAND THROUGH THE AFTERNOON WHILE SLOWLY LIFTING NORTHWARD. BY
NIGHTFALL THE PRECIP BAND WILL CONTINUE TO WORK NORTHWARD INTO INYO
COUNTY AS WELL ACROSS CLARK AND MOHAVE COUNTIES BEFORE LIFTING INTO
OUR SOUTHERN GREAT BASIN ZONES EARLY TUESDAY MORNING.
AS MENTIONED PREVIOUSLY...MODELS HAVE TRENDED TOWARDS TAKING THE
BEST QPF INTO INYO COUNTY WITH LESSER AMOUNTS FURTHER EAST. IN
FACT...IT LOOKS LIKE MUCH OF INYO COUNTY OUTSIDE OF THE LOWEST
VALLEYS STAND A GOOD CHANCE TO PICK UP A QUARTER TO A HALF AN INCH
OF PRECIPITATION...AND EVEN MORE ALONG THE SIERRA CREST. FURTHER
EAST ACROSS CLARK AND MOHAVE COUNTY...I STILL ANTICIPATE WIDESPREAD
RAIN BUT AMOUNTS MAY STRUGGLE TO EXCEED A TENTH OF AN INCH IN THE
LOWEST DESERT VALLEYS. HOWEVER...PLAYING DEVILS ADVOCATE...WITH
SUCH A MOISTURE RICH AIRMASS MOVING IN...IT WONT TAKE MUCH TO
SQUEEZE OUT MORE PRECIP THAN INDICATED BY MODEL GUIDANCE. WITH ALL
THIS IN MIND...IVE STAYED THE COURSE WITH THE FORECAST AND
MAINTAINED SIMILAR QPF VALUES ACROSS THE LAS VEGAS METRO AS WHAT WAS
INHERITED...WITH VALUES BETWEEN A TENTH AND A QUARTER OF AN INCH
EXPECTED.
FINALLY...SNOW LEVELS WILL BE RATHER HIGH FOR LATE JANUARY WITH THIS
STORM THANKS TO THE SUBTROPICAL ORIGIN OF THE MOISTURE. SEVERAL
INCHES OF SNOW ARE POSSIBLE ABOVE 7500 FEET PARTICULARLY ACROSS THE
SIERRA AND AND ALSO THE HIGHEST REACHES OF THE SPRING MOUNTAINS.
AFTER COORDINATING WITH THE NEIGHBORING OFFICES...DECIDED TO HOLD
OFF ON ANY WINTER WEATHER HEADLINES FOR NOW. THE DAY SHIFT CAN
REEVALUATE THE NEED FOR ANY ADVISORIES. ANY SNOW OF CONSEQUENCE WITH
REGARDS TO IMPACTS WOULD BE AT ELEVATIONS ABOVE 8000 FEET SUCH AS
THOSE LEADING TO LEE CANYON OR OVER THE SIERRA CREST.
.LONG TERM...WEDNESDAY THROUGH SUNDAY.
THE NEXT UPPER LEVEL DISTURBANCE TO AFFECT THE AREA WILL SLIDE INTO
THE REGION ON THURSDAY AFTERNOON...REINTRODUCING PRECIPITATION
CHANCES ACROSS MUCH OF THE AREA THROUGH SATURDAY. CURRENTLY THE
PRIMARY CONCERN WITH THIS NEXT IMPULSE IS THE TIMING DIFFERENCES
BETWEEN MODEL RUNS...WITH THE GFS BEING MUCH MORE PROGRESSIVE THAN
THE EUROPEAN AND NAM. HOWEVER LOOKING AT RUN TO RUN
CONSISTENCY...EACH MODEL HAS SHOWN SIGNS OF SPEEDING UP THIS NEXT
IMPULSE TO SOME DEGREE OVER THE PAST FEW MODEL RUNS. THIS TREND
WOULD SUPPORT LESS POPS WEST OF THE COLORADO RIVER AND WOULD FAVOR
FAR EASTERN NEVADA AND ARIZONA FOR THE HIGHEST POPS. DID SLIGHTLY
INCREASE POPS IN THESE AREAS FOR THESE REASONS AND THE FACT THAT
SUFFICIENT UPPER DIFLUENCE CONTINUES TO LOOK MOST LIKELY THERE.
MODELS CONTINUE TO SUPPORT THIS LOW WRAPPING UP AND MOVING SOUTHWARD
AS HIGH PRESSURE BUILDS BACK INTO THE AREA DURING THE LATTER PART OF
THE WEEKEND INTO EARLY NEXT WEEK. THIS WILL LEAD TO A DRYING TREND
ACROSS THE AREA LATE SATURDAY THROUGH THE BEGINNING OF THE WEEK. THE
WARM NATURE OF THIS SYSTEM WILL KEEP SNOW LEVELS HIGH FOR THIS TIME
OF YEAR...WITH LEVELS AT OR AROUND 7000 FEET THROUGH THIS EVENT.
TEMPERATURES WILL REMAIN A FEW DEGREES ABOVE NORMAL BEFORE A SLIGHT
WARMING TREND OCCURS LATE THIS WEEKEND INTO THE BEGINNING OF THE
WEEK.
&&
.AVIATION...FOR MCCARRAN...INCREASING CLOUDS EXPECTED TODAY WITH
RAIN EXPECTED TO IMPACT THE AIRFIELD TONIGHT AFTER 6Z. BIGGEST
CONCERNS WILL BE REDUCTIONS IN VISIBILITY AND LOW CIGS. CIGS FALLING
BELOW 5K EXPECTED AFTER 6Z AND POSSIBLY FALLING BELOW 3K AT TIMES
DURING THE HEAVIEST RAINFALL. WINDS THROUGH THE PERIOD LOOK TO
REMAIN LIGHT.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...INCREASING CLOUDS AND RAIN EXPECTED FOR MUCH OF THE
AREA STARTING THIS AFTERNOON ACROSS AREAS SOUTH OF A KDAG-KEED-KIGM
LINE AND LIFTING NORTH IN THE EVENING. REDUCTIONS IN VISIBILITY AND
LOW CIGS EXPECTED IN THE HEAVIER RAINFALL WITH WIDESPREAD MOUNTAIN
OBSCURATIONS EXPECTED.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION IS NOT EXPECTED
BUT SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT RAIN OR SNOW
IN THE COMING DAYS.
&&
$$
UPDATE...PIERCE
SHORT TERM/AVIATION...OUTLER
LONG TERM...PULLIN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
647 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 /00Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 00Z THURSDAY...A VARIETY OF FLIGHT CATEGORIES WILL EXIST
FOR MUCH OF TONIGHT BEFORE IMPROVING TO VFR AREA-WIDE ON
WEDNESDAY. SNOW SHOWERS AND LOW STRATUS CONTINUE TO LINGER THIS
EVENING AS COASTAL LOW DEPARTS THE NORTHEASTERN US. THESE WILL BE
MOST PREVALENT AT MPV/BTV/PBG WHERE PERIODS OF IFR ARE LIKELY
THROUGH 04Z-08Z. SNOW SHOWERS ALSO POSSIBLE AT RUT/SLK BUT WILL ONLY
SHOW MVFR FOR NOW. MSS WILL REMAIN DRY. SNOW SHOWERS WILL TAPER
OFF LATE TONIGHT AND EARLY WEDNESDAY MORNING. OTHERWISE LOW
STRATUS WITH A MIX OF VFR/MVFR CEILINGS WILL PERSIST OVERNIGHT
BEFORE IMPROVING AND SCATTERING OUT ON WEDNESDAY.
GUSTY NORTHWEST WINDS WITH GUSTS UP TO 25 KNOTS CONTINUE INTO
TONIGHT...GRADUALLY LESSENING AS THE NIGHT PROGRESSES. WINDS ON
WEDNESDAY WILL BE NORTH/NORTHWEST FROM 5 TO 10 KNOTS AT
BTV/RUT/MPV...NORTHEAST AT PBG FROM 5 TO 10 KNOTS...AND
WEST/SOUTHWEST FROM 5 TO 10 KNOTS AT MSS/SLK.
OUTLOOK 00Z THURSDAY 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...MUCCILLI/NASH
EQUIPMENT...WFO BTV
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1231 PM EST MON JAN 26 2015
.SYNOPSIS...
LOW PRESSURE AND A COLD FRONT WILL CROSS THE AREA TODAY AND
CONGEAL INTO A POWERFUL NEW ENGLAND NOR`EASTER. HIGH PRESSURE WILL
MOVE INTO THE CAROLINAS BY THURSDAY FOLLOWED BY ANOTHER COLD FRONT
THURSDAY NIGHT INTO FRIDAY. HIGH PRESSURE WILL BUILD IN FROM THE
NORTHWEST OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM MONDAY...AS EXPECTED CUMULUS CLOUDS ARE FILLING IN
ACROSS SOUTH CAROLINA WHERE SUNNY SKIES ALLOWED TEMPERATURES TO
SURGE INTO THE UPPER 50S THIS MORNING. THE LATEST HRRR SHOWS
ISOLATED SHOWERS MAY BEGIN TO DEVELOP HERE AS EARLY AS 19Z/2 PM EST.
OTHERWISE FEW CHANGES HAVE BEEN MADE TO THE FORECAST. PREVIOUS
DISCUSSION FROM 930 AM FOLLOWS...
COLD UPPER LEVEL LOW PRESSURE CENTERED OVER WESTERN VIRGINIA WILL
MOVE OFF THE COAST THIS EVENING. UNTIL THEN...VERY CHILLY CONDITIONS
AT 500 MB (TEMPS AS COLD AS -26C ACROSS SE NORTH CAROLINA) WILL
CONTINUE...PRODUCING STEEP MID LEVEL LAPSE RATES AT OR JUST STEEPER
THAN THE MOIST ADIABATIC LAPSE RATE. SATELLITE SHOWS CLEAR SKIES
ACROSS MOST OF SOUTH CAROLINA AND SPREADING EASTWARD INTO SE NORTH
CAROLINA. AS SUNSHINE HEATS TEMPERATURES INTO THE UPPER 50S WE
EXPECT A HEALTHY CUMULUS CLOUD DECK TO DEVELOP THIS AFTERNOON WITH
EMBEDDED TOWERING CUMULUS AND SHOWERY CB`S AS WELL. THIS BEST
POTENTIAL INITIALLY SHOULD DEVELOP IN THE NC SOUTHERN
PIEDMONT...ROTATING SOUTHEASTWARD TOWARD CAPE FEAR THIS EVENING. NOT
EVERY LOCATION WILL SEE MEASURABLE RAIN.
CHANGES TO THE FORECAST THIS MORNING INCLUDE BUMPING HIGHS UP TO
NEAR 60 NEAR THE SANTEE RIVER...DELAYING THE DEVELOPMENT OF SHOWERS
INTO THE EARLY-MID AFTERNOON HOURS...DELAYING THE ONSET OF CLEARING/
DRYING CONDITIONS THIS EVENING AS MOST OF THE LATEST MODEL DATA
INDICATES SHOWERS SHOULD CONTINUE THROUGH THE EVENING NEAR CAPE FEAR.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM MONDAY...BLOCKBUSTER STORM CLOBBERING NEW ENGLAND ON
TUESDAY AND AS AS USUAL WHEN THIS IS THE CASE COLD AIR WILL READILY
INVADE MOST AREAS EAST OF THE APPALACHIANS. A SMALL LAYER OF LOW
LEVEL MOISTURE STARTS OUT THE DAY BUT WITH A GREAT DEPTH OF THE
COLUMN A DRY NWRLY FLOW THIS SHOULD MIX OUT FOR NEARLY FULL
SUNSHINE. EVEN SO, THE CAA WILL CAP HIGHS IN THE MID 40S, SOME 10
DEGREES BELOW CLIMO. OFT TIMES WITH SUCH A LARGE AND STRENGTHENING
STORM OVER THE NORTHEASTERN U.S. IT IS OFTEN RATHER BLUSTERY LOCALLY
BUT THIS DOES NOT APPEAR TO BE IN THE OFFERING THIS TIME AROUND. WE
SEEM TO FIND OURSELVES IN A RELATIVE MINIMUM IN THE LOW LEVEL WIND
FIELD BETWEEN THE JET ASSOC WITH THE ACTUAL STORM CENTER AND THE
MAIN AXIS OF COLD AIR ADVECTION WEST OF THE LOW LVL THERMAL TROUGH
OVER THE GULF STATES. THERE WILL BE JUST ENOUGH WINDS TUESDAY NIGHT
TO PREVENT RADIATIONAL COOLING. SO IN AN AIRMASS COLD ENOUGH TO
BRING LOWS CLOSE TO 20 WE SHOULD INSTEAD REMAIN IN THE UPPER
20S...PERHAPS LOW 30S FAR SRN ZONES. UPPER TROUGH AXIS WELL OFFSHORE
BY WEDNESDAY WHILE THE AXIS OF HIGHEST SURFACE PRESSURES BUILDS
RIGHT OVERHEAD. SO WHILE THERE MAY BE SOME MINOR RECOVERY IN THE
BOUNDARY LAYER TEMPERATURES THE SHALLOW NATURE OF THE MIXING
(2200FT?) WILL BRING CHILLY HIGHS NEARLY IDENTICAL TO THOSE OBSERVED
TUESDAY. FORECAST SOUNDINGS WEDNESDAY NIGHT MUCH MORE TYPICAL OF
RADIATIONAL COOLING WITH NEAR ISOTHERMAL LAYER POSSIBLY AS DEEP AS
9KFT. HOWEVER DUE TO THE AFOREMENTIONED RECOVERY IN TEMPERATURES
WEDNESDAY NIGHT LOWS WILL BE SIMILAR TO THOSE OF THE NIGHT BEFORE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 300 AM MONDAY...SURFACE HIGH MOVES OVERHEAD EARLY THURSDAY AND
JUST OFFSHORE IN A WEAKENING STATE LATER IN THE DAY. ZONAL MID LEVEL
FLOW NORMAL QUITE DRY BUT SOME PVA INDUCED BY THE WESTERLIES
REACTING WITH SOME LOW LEVEL MOISTURE FLOW IN THE SW WINDS TO BRING
AN INCREASE IN CLOUDS. MEANWHILE AFTERNOON TEMPS REBOUND CLOSE TO
CLIMO. WILL THIS MOISTURE BE ADEQUATE TO SUPPORT SOME PRECIPITATION
AS THE NEXT UPPER WAVE AND COLD FRONT PASS THROUGH THURSDAY NIGHT
INTO FRIDAY MORNING? HARD TO SAY THIS FAR OUT BUT GIVEN THE FAIRLY
ROBUST STRENGTH OF THE TROUGH THE SLIGHT CHANCE INHERITED POPS LOOK
FINE. EITHER WAY IT WILL STAY MILD ENOUGH TO PRECLUDE ANY PTYPE
CONCERNS. THE WEEKEND WILL BASICALLY JUST FEATURE COLD AIR ADVECTION
IN NORTHWESTERLY FLOW AROUND HUDSON BAY VORTEX. THERE MAY AT SOME
TIME BE ENOUGH OF A SPOKE OF ENERGY WITHIN THIS FLOW TO YIELD ASCENT
AND EVEN OFFSHORE PRESSURE FALLS. ANY SUCH DISTURBANCE IS FAR BEYOND
BEING SAMPLED BY UPPER AIR NETWORK AND SO SOLUTIONS MAY SHOW HIGH
VARIABILITY FROM RUN TO RUN. AT THIS TIME IT SEEMS MOST PRUDENT TO
FOCUS ON THE CHILLY TEMPS AND ADDRESS ANY CLOUD COVER AND LOW RAIN
CHANCES AT A FUTURE TIME.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 18Z...VFR CONDITIONS THIS AFTERNOON COULD GIVE WAY TO PERIODS
OF MVFR CIGS IN THE LATE AFTERNOON AND EVENING HOURS. SFC HEATING
WITH VERY COLD AIR ALOFT WILL ALLOW FOR ISO/SCT SHOWERS TO DEVELOP
BY 20-21Z...MOST LIKELY OVER OUR NORTHERN TIER. THEREFORE...WILL
MAINTAIN VCSH AT ALL TERMINALS AND INTRODUCE TEMPO -SHRA AT KLBT AND
KILM THIS EVENING. DO NOT ANTICIPATE MUCH IN THE WAY OF AVIATION
IMPACTS OTHER THAN MVFR CIGS AND PERHAPS TEMPO MVFR VSBYS. W-NW
WINDS AROUND 10 KT WITH GUSTS OF 15-20 KT CAN BE EXPECTED TODAY INTO
TONIGHT AS LOW PRESSURE BEGINS RAPIDLY DEEPENING OFF THE
MID-ATLANTIC COAST. MVFR CIGS MAY LINGER OVERNIGHT...ESPECIALLY AT
KILM AS MOISTURE WRAPS AROUND THE NOR`EASTER. ELSEWHERE...VFR
CONDITIONS SHOULD PREVAIL AS THE LOW CLOUDS SCATTER OUT AND LOW
PRESSURE LIFTS NORTHWARD. NW WINDS 8-12 KT WILL PERSIST INTO TUESDAY
WITH A FEW HIGHER GUSTS POSSIBLE.
EXTENDED OUTLOOK...VFR WILL PREVAIL TUESDAY THROUGH SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM MONDAY...BUOYS REPORT LITTLE CHANGE IN SEA HEIGHT
SINCE THE 930 AM UPDATE THIS MORNING. WEST WINDS HAVE ACTUALLY
DECREASED IN SPEED A LITTLE BIT...POSSIBLY DUE TO DIURNAL HEATING
EFFECTS INLAND. AS CLOUDS INCREASE INLAND WE HEAD TOWARD EVENING
LOOK FOR WIND SPEEDS TO SURGE UP TOWARD 20-25 KT. PREVIOUS
DISCUSSION FROM 930 AM FOLLOWS...
BASED ON BUOY WAVE OBSERVATIONS OF 5.5 FEET FROM THE WILMINGTON
"HARBOR" BUOY LOCATED ABOUT 5 MILES SOUTH OF THE MOUTH OF THE CAPE
FEAR RIVER...I HAVE STARTED THE SMALL CRAFT ADVISORY EARLY (NOW) FOR
ALL ZONES AS IT IS LIKELY 6 FOOT SEAS ARE BEING EXPERIENCED ACROSS
AREAS WITH A LONG FETCH TO WESTERLY WINDS. LOW PRESSURE CENTERED
OVER NORTHWESTERN NORTH CAROLINA WILL SHIFT ITS ENERGY OFF THE
VIRGINIA COAST THIS AFTERNOON...AND THIS NEW LOW WILL BECOME THE
DOMINANT FEATURE FOR EAST COAST WEATHER OVER THE NEXT 24 HOURS.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM MONDAY...MODERATE OFFSHORE FLOW ON TUESDAY AS LOW
PRESSURE BOMB OFF THE NEW ENGLAND COAST BRINGS CYCLONIC FLOW ACROSS
THE ENTIRE EAST COAST. DUE TO THE DISTANCE OF THIS STORM AND THE
FACT THAT ITS BACKSWELL DOES NOT SIGNIFICANTLY REFRACT AROUND CAPE
HATTERAS TOWARDS OUR REGION IT SEEMS THAT WE MAY NOT SEE ANY
ADVISORIES SAVE FOR PERHAPS THE FIRST FEW HOURS OF THE PERIOD.
THEREAFTER DECREASING WINDS AND SEAS EXPECTED AS THE GRADIENT EASES.
NOT TOO FAR OFFSHORE HOWEVER THERE WILL STILL BE A BROAD AGITATED
WIND FIELD AND MARINERS VENTURING OUT PAST OUR 20NM ZONES ARE URGED
TO CHECK WITH THE OFFSHORE WATERS FORECAST FROM OPC. A FURTHER
ABATING OF THE WIND FIELD IS SLATED FOR WEDNESDAY AND THE WIND
DIRECTION WILL ALSO BE VEERING AS HIGH PRESSURE BUILDS IN FROM THE
NORTHWEST...TAKING UP RESIDENCE ALONG THE COASTLINE BY
AFTERNOON/EVENING.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 300 AM MONDAY...AN INITIALLY LIGHT SOUTH TO SOUTHWESTERLY
RETURN FLOW WILL BECOME ESTABLISHED ACROSS THE SOUTHEAST AS A
WEAKENING HIGH PRESSURE CELL MOVES OFF THE COAST. BY EVENING THIS
WIND FIELD WILL INCREASE A BIT IN RESPONSE TO AN APPROACHING COLD
FRONT FROM THE NORTHWEST. THE APPROACH AND PASSAGE OF THIS BOUNDARY
WILL BRING AN EXTENDED PERIOD OF VEERING DIRECTION WHICH PAIRED WITH
THE HIGHER WIND SPEEDS COULD LEAD TO SOME MARGINAL 6 FT SEAS OVER
MAINLY NORTHERN ZONES. NW WINDS BEHIND THE FRONT ON FRIDAY WITH WIND
AND SEAS BOTH SHOWING A DOWNWARD/IMPROVING TREND.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL TO 7 AM EST TUESDAY FOR
AMZ250-252-254-256.
&&
$$
SYNOPSIS...MBB
NEAR TERM...TRA
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
357 AM CST MON JAN 26 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 355 AM CST MON JAN 26 2015
FORECAST CHALLENGES CONCERN MAINLY TEMPERATURES AND MID WEEK PCPN
CHANCES WITH COLD FRONTAL PASSAGE. MODELS PRETTY CLOSE WITH THERMAL
PROFILES BUT DIFFER ON SNOW POTENTIAL WITH MID WEEK CFP. MODELS
HAVE OVERDONE QPF ON NEARLY EVERY OF THE RECENT WAVES IN NW FLOW
SO FOR NOW WILL BE CONSERVATIVE WITH SNOW POTENTIAL.
CURRENT RADAR RETURNS ASSOCIATED WITH MID LEVEL CLOUDS AROUND 10K
FT SO PULLED POPS EXCEPT FOR THE FAR NE FA. EVEN THERE CANADIAN
RADARS NOT IMPRESSIVE SO BACKED OFF ON COVERAGE THERE THIS
MORNING. STRONG WARM ADVECTION WITH WESTERLY WINDS APPROACHING
WESTERN VALLEY. BY 18Z OR SO SOME BACK DOOR COLD ADVECTION TAKES
OVER. WESTWARD EXTENT OF LOWER CIGS WILL ALSO PLAY A PART ON HOW
MUCH WE CAN RECOVER WITH MINIMAL SNOW COVER. SW FA INTO SOUTHERN
VALLEY WILL HAVE BEST POTENTIAL FOR SOLAR SO HAVE WARMEST READINGS
THERE.
HIGH PRESSURE BUILDS INTO THE FA OVERNIGHT AND CLOUD COVER WILL
AGAIN HAVE IMPACT ON TEMPERATURES SO STAYED CLOSE TO INHERITED
VALUES.
GOOD PUSH OF WARM ADVECTION TUESDAY WITH SOUTHERLY WINDS SO WILL
BE ANOTHER DAY OF WELL ABOVE AVERAGE TEMPERATURES.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 355 AM CST MON JAN 26 2015
COLD FRONT LOOKS TO REMAIN NORTH OF FA UNTIL WEDNESDAY SO ANOTHER
MILD NIGHT.
COLD FRONTAL PASSAGE FROM N-S WEDNESDAY. MODELS SHOWING
DIFFERENCES ON MAINLY POST FRONTAL PCPN POTENTIAL. BASED ON RECENT
TRENDS OF OVER FORECASTING PCPN WITH THESE WAVES WILL KEEP POPS ON
LOW END UNTIL CONFIDENCE INCREASES.
LONG WAVE RIDGE REMAINS OVER WESTERN NORTH AMERICA AND LONG WAVE
TROUGH OVER THE EASTERN NORTH AMERICA THROUGH THE PERIOD. LONG WAVE
RIDGE BUILDS OVER THE BERING STRAITS AND INTO AK BY DAY 5 THEN
WEAKENS. CROSS POLAR FLOW DEVELOPS THEREAFTER.
THE ECMWF AND THE GFS WERE IN REASONABLE AGREEMENT AT THE BEGINNING
OF THE PERIOD. THE ECMWF BECOMES A FASTER SOLUTION AND A MORE
AMPLIFIED SOLUTION BY 00Z MON. MODELS DIVERGE SIGNIFICANTLY BY THE
END OF THE PERIOD. GFS KEEPS THE SAME CURRENT PATTERN WITH SHORT
WAVE RIDGES MOVING ACROSS THE NORTHERN PLAINS WHILE THE ECMWF
INDICATED MORE SIGNIFICANT ARCTIC INTRUSIONS. WILL PREFER THE
ECMWF.
HIGH TEMPS WERE INCREASED TWO TO THREE DEGREES FOR THU AND ONE OR
TWO DEGREES FOR FRI. HIGH TEMPS WERE DECREASED THREE TO SIX DEGREES
ON SAT AND ONE TO THREE DEGREES ON SUN FROM YESTERDAYS FORECAST
PACKAGE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1142 PM CST SUN JAN 25 2015
MODEL MOS GUIDANCE FOR CIGS HAVE BEEN WAY TOO PESSIMISTIC. THEY
HOLD EVERYONE IN MVFR CIGS ALL NIGHT. THAT IS NOT THE CASE. MOST
AREAS HAVE SEEN LOWER LEVEL CLOUDS EXIT AS DRY LOW LEVEL AIR MOVES
IN. LEAVING SOME MID CLOUDS....EXCEPT FOR FAR NE FCST AREA.
SATELLITE SHOWS A LARGE CLEAR AREA IN SW MANITOBA MOVING INTO
NCNTRL ND AND THIS WILL SPREAD SOUTHEAST AS WELL. THUS KEPT MOST
SITES VFR OVERNIGHT OR BECOMING THAT WAY. WINDS WILL BE SOUTH TO
SOUTHWEST GUSTY AT TIMES TO 20-25KTS. MONDAY IS QUITE UNCERTAIN
HOW CLOUDS WILL TREND. MVFR CIGS BEHIND THE LOW IN WEST CENTRAL
MANITOBA UP NORTH OF DAUPHIN AND I THINK RAP MODEL HAS GOOD IDEA
OF THAT MOVING SOUTH INTO MUCH OF THE FCST AREA DURING THE DAY
MONDAY SO TRENDED IN THAT DIRECTION AS SFC WINDS TURN NORTHWEST.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...VOELKER
LONG TERM...HOPPES/VOELKER
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1245 AM CST MON JAN 26 2015
.UPDATE...
ISSUED AT 1245 AM CST MON JAN 26 2015
WAA ACROSS THE AREA WILL BE REPLACED WITH WEAK CAA FOR THE REST OF
THE MORNING AS LOW PRESSURE SLIDES SOUTHEAST INTO MINNESOTA. AREA
OF LIGHT RAIN/FREEZING RAIN WILL PUSH OUT OF THE SOUTHERN JAMES
RIVER VALLEY BY 09Z. NORTHWEST WINDS ARE ON THE INCREASE AS
GRADIENT FORCING INCREASES ACROSS THE STATE. WINDS WILL SLOWLY
SUBSIDE LATER THIS MORNING WEST TO EAST. TEMPERATURES WILL REMAIN
STEADY OR RISING IN THE 30S FOR THE REST OF THE OVERNIGHT.
UPPED SKY COVER A BIT WITH SCT-BKN MID LEVEL CLOUDS ALOFT AND
EXPECTED TO CONTINUE TO STREAM IN FROM THE NORTH.
UPDATE ISSUED AT 924 PM CST SUN JAN 25 2015
ENDED THE POPS BASED ON RADAR TRENDS AND LATEST HRRR RUNS. LEFT
THE FORECAST DRY FOR TONIGHT.
UPDATE ISSUED AT 648 PM CST SUN JAN 25 2015
BASED ON CANADIAN AND US RADARS AND LATEST HRRR MODEL WILL TRIM
POPS AFTER 06Z TONIGHT AS HRRR MODEL TAKES THE LIGHT PRECIP EAST OF
THE CWA. BOOSTED WINDS ABOUT 20 TO 30 MPH ACROSS PARTS OF THE
NORTH AND EAST TONIGHT WITH STRENGTHENING PRESSURE GRADIENT AS
JET MAX ALOFT MOVES THOUGH.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 322 PM CST SUN JAN 25 2015
...RECORD HIGH TEMPERATURES FORECAST WEST MONDAY...
A WARM FRONT IS CURRENTLY ENTERING THE MT/ND BORDER. THIS FRONT
WILL CONTINUE TO PUSH EAST TONIGHT. THERE WILL BE A SLIGHT CHANCE
FOR A WINTRY MIX OF RAIN...SLEET...AND FREEZING RAIN TO DEVELOP
ALONG AND EAST OF A LINE FROM THE TURTLE MOUNTAIN REGION INTO THE
JAMES RIVER VALLEY THIS EVENING. IMPACTS SHOULD BE MINIMAL...BUT
NOT ZERO. THEREFORE...WILL LEAVE THE WINTRY MIX IMPACTS MENTION IN
THE HWO FOR THIS UPDATE.
AS WARM AIR ADVECTION DEVELOPS OVER WESTERN AND CENTRAL NORTH
DAKOTA TONIGHT...TEMPERATURES SHOULD EITHER REMAIN STEADY OR
SLOWLY INCREASE OVERNIGHT. ABOVE NORMAL LOWS ARE EXPECTED.
DRY/WARM AIR IS PROGGED TO CONTINUE TO ADVECT INTO THE REGION
MONDAY. SOME MAXIMUM TEMPERATURE RECORDS WILL BE IN JEOPARDY OF
BEING BROKEN...ESPECIALLY OVER WESTERN NORTH DAKOTA. THE FOLLOWING
TABLE IS A RUN DOWN OF THE FORECAST HIGHS AND ASSOCIATED RECORD
HIGHS FOR SELECTED SITES ACROSS WESTERN AND CENTRAL NORTH DAKOTA.
LOCATION MON HI TEMP MON HI TEMP
FORECAST RECORD
DICKINSON 53 49 IN 1931
WILLISTON 47 47 IN 2006
BISMARCK 48 52 IN 1942
MINOT 44 58 IN 1906
JAMESTOWN 42 52 IN 1990
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 322 PM CST SUN JAN 25 2015
RECORD HIGH TEMPERATURES ARE POSSIBLE TUESDAY.
AN UPPER LEVEL RIDGE WILL CENTER ACROSS WESTERN NORTH
DAKOTA TUESDAY AFTERNOON WITH WARM AIR ADVECTION KICKING IN AHEAD
OF A SURFACE LOW. THIS COMBINED WITH WEST...DOWNSLOPING WINDS...MINIMAL
OR NONEXISTENT SNOWPACK AND PLENTY OF SUNSHINE...RECORD HIGH
TEMPERATURES ARE POSSIBLE ON TUESDAY.
THE 12 UTC ECMWF HAS 13-14 DEGREES CELSIUS AT 850MB WHILE THE GFS
AND NAM SHOW CLOSER TO 11-12. IF THESE TEMPERATURES CAN MIX DOWN
TO THE SURFACE IT SEEMS LIKELY THAT TEMPERATURES WILL CLIMB INTO
THE UPPER 50S ACROSS THE SOUTHWEST. IT ISN`T COMPLETELY OUT OF THE
REALM OF POSSIBILITY THAT A FEW AREAS REACH 60.
LATER THIS WEEK WE WILL LIKELY TRANSITION INTO NORTHWEST FLOW WITH
A TROUGH SPILLING INTO THE GREAT LAKES REGION. HOWEVER...LATEST
MODELS TEND TO KEEP THE AXIS OF THE TROUGH A LITTLE FURTHER EAST.
THIS WOULD MEAN TEMPERATURES ACROSS WESTERN AND CENTRAL NORTH
DAKOTA MAY NOT COOL DOWN AS MUCH AS INITIALLY THOUGHT EARLIER.
BUT...THIS IS STILL SEVERAL DAYS AWAY AND A LOT CAN CHANGE BETWEEN
NOW AND THEN. IT DOES APPEAR WE WILL TRANSITION INTO A MORE ACTIVE
PATTERN WITH SEVERAL CHANCE FOR LIGHT PRECIPITATION POSSIBLE LATER
THIS WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1245 AM CST MON JAN 26 2015
VFR CONDITIONS THROUGH THE 06Z TAF PERIOD WITH A SCT-BKN MID LEVEL
CLOUD DECK. A STEADY NORTHWEST WIND OF 15 TO NEAR 30 KTS FORECAST
THROUGH THE MORNING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...NH
SHORT TERM...TM
LONG TERM...AJ
AVIATION...NH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1147 PM CST SUN JAN 25 2015
.UPDATE...
ISSUED AT 1142 PM CST SUN JAN 25 2015
LAST PATCH OF FAST MOVING PRECIP MOVING INTO SE ND ATTM. PRODUCING
A FEW SPRINKLES AND FARGO CAME NR 05Z WITH A FEW FLAKES. THIS
ACTIVITY WILL MOVE OUT OF THE FCST AREA NEXT FEW HOURS. VERY
DIFFICULT TO GET HANDLE ON HOW MUCH WAS REACHING THE GROUND...BUT
BASED ON OBS AND DBZ ON RADAR SOME PRETTY VICIOUS VIRGA WAS
OCCURRING TONIGHT. IF DRY LAYER NR 850 MB WASNT THERE A WHOLE
DIFFERENT STORY. LIGHT SNOW IN LAKE OF THE WOODS REGION CONTINUES
BUT CANADIAN RADAR AND OBS INDICATE MOST OF IT WILL EXIT EAST
LATER TONGHT AND SNOW AMOUNTS LESS. LOWERED TO UP TO 1 INCH
BAUDETTE AREA. TEMP SURGE IS ON AND EXPECT TEMPS TO RISE TO ABOVE
FREEZING OVER ERN ND AND THE RRV AS THE NIGHT PROGRESSES...ALREADY
THAT WAY IN DVL BASIN.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 300 PM CST SUN JAN 25 2015
THE MAIN CHALLENGE WILL BE LIGHT PRECIP TONIGHT THEN TEMPS. MODELS
ARE IN GOOD OVERALL AGREEMENT...WITH JUST SOME SLIGHT TIMING
DIFFERENCES.
FOR TONIGHT...ISENTROPIC LIFT IN THE MID LEVELS AND A SPEED MAX
WILL MOVE IN FAST NW FLOW ALOFT. THERE WILL BE A BAND OF LIGHT
SNOW IN THE FAR NORTHEAST FA...WHERE UP TO AN INCH IS POSSIBLE.
FURTHER TO THE SOUTH AND WEST...SOME FREEZING RAIN OR A MIX OF
FREEZING RAIN/SNOW IS POSSIBLE. WE HAVE INTRODUCED POPS FOR THIS
AND MENTIONED IN THE UPDATED WEATHER STORY. WE WILL NEED TO
MONITOR THIS THREAT FOR ICING OVERNIGHT...EVEN WITH TEMPS RISING
TO NEAR FREEZING LATE WITH INCREASING S/SW WINDS SHIFTING WEST LATE.
ON MONDAY...SOME LINGERING LIGHT SNOW IS POSSIBLE IN NW MN DURING
THE MORNING...OTHERWISE EXPECT A MILD AND DRY DAY WITH W/NW WINDS
INCREASING INTO THE BREEZY CATEGORY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 300 PM CST SUN JAN 25 2015
ON TUE...EXPECT ANOTHER MILD AND DRY DAY WITH THE WARM WEATHER
CONTINUING. TEMPS SHOULD CLIMB TO AROUND 40 WEST INTO THE MID 30S
ELSEWHERE. IF THERE IS MORE INSOLATION THAN CURRENTLY
PROGGED...TEMPS COULD BE EVEN WARMER.
ON WED...A COLD FRONT WILL DROP FROM NORTH TO SOUTH THROUGH THE
DAY. THERE SHOULD BE AT LEAST SOME LIGHT SNOW IN THE NORTHER
AREAS. WE CAN/T RULE OUT SOME FREEZING DRIZZLE GIVEN THE WARM
ENVIRONMENT...BUT FOR NOW WON/T MENTION BUT MONITOR THREAT. IT
WILL BE MILD WITH TEMPS FALLING IN THE AFTERNOON BEHIND THE FRONT
IN NORTHERN AREAS.
FOR WED NIGHT THROUGH SAT...THE BEGINNING OF THE EXTENDED WILL
START OUT WARM WITH TEMPS ABOVE NORMAL. THERE COULD BE SOME LIGHT
SNOW WED NIGHT BEHIND A COOL FRONT...THEN AGAIN TOWARDS THE END OF
NEXT WEEK. A MORE SIGNIFICANT COLD FRONT IS PROGGED BY NEXT
SAT...THAT COULD MEAN AN END TO THE MILD TEMPS WE HAVE SEEN
RECENTLY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1142 PM CST SUN JAN 25 2015
MODEL MOS GUIDANCE FOR CIGS HAVE BEEN WAY TOO PESSIMISTIC. THEY
HOLD EVERYONE IN MVFR CIGS ALL NIGHT. THAT IS NOT THE CASE. MOST
AREAS HAVE SEEN LOWER LEVEL CLOUDS EXIT AS DRY LOW LEVEL AIR MOVES
IN. LEAVING SOME MID CLOUDS....EXCEPT FOR FAR NE FCST AREA.
SATELLITE SHOWS A LARGE CLEAR AREA IN SW MANITOBA MOVING INTO
NCNTRL ND AND THIS WILL SPREAD SOUTHEAST AS WELL. THUS KEPT MOST
SITES VFR OVERNIGHT OR BECOMING THAT WAY. WINDS WILL BE SOUTH TO
SOUTHWEST GUSTY AT TIMES TO 20-25KTS. MONDAY IS QUITE UNCERTAIN
HOW CLOUDS WILL TREND. MVFR CIGS BEHIND THE LOW IN WEST CENTRAL
MANITOBA UP NORTH OF DAUPHIN AND I THINK RAP MODEL HAS GOOD IDEA
OF THAT MOVING SOUTH INTO MUCH OF THE FCST AREA DURING THE DAY
MONDAY SO TRENDED IN THAT DIRECTION AS SFC WINDS TURN NORTHWEST.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...DK
LONG TERM...GODON/DK
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1256 AM EST MON JAN 26 2015
.SYNOPSIS...
THE CENTER OF AN ALBERTA CLIPPER WILL SWING THROUGH KENTUCKY OVERNIGHT.
THIS WILL BE FOLLOWED BY A WEAK UPPER DISTURBANCE DROPPING ACROSS
THE AREA MONDAY NIGHT INTO TUESDAY MORNING. HIGH PRESSURE WILL
BUILD IN WEDNESDAY...BRINGING QUIET WEATHER FOR MID WEEK BEFORE
YET ANOTHER SYSTEM BRINGS MIXED PRECIPITATION ON THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
RAIN/SNOW LINE CONTINUES TO MAKE IT WAY SLOWLY SOUTH AND
SOUTHEASTWARD. THE 1304 1000-850MB THICKNESS FROM THE RAP IS
HANDLING THE CHANGEOVER NICELY. STARTING TO SEE SOME BREAKS IN
THE PCPN IN THE WHITEWATER VALLEY AND THE BACKEDGE OF APPROACHING
NE MERCER COUNTY. ONLY MADE A FEW TWEAKS IN THE PCPN FORECAST FOR
TONIGHT. PRETTY MUCH KEPT THE SAME SNOW NUMBERS AND CHANGEOVER
TIMING. DID SPEED UP THE ENDING OF THE SNOW LATE IN THE PERIOD.
COLDER AIR HAS WORKED INTO THE N A LITTLE QUICKER THAN EXPECTED.
KNOCKED A DEGREE OR SO OFF PREVIOUS LOWS TONIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
BECAUSE OF THE AMPLIFICATION AND THEREFOR SLOWER DEPARTURE OF THE
SYSTEM WITH POTENTIAL FOR HIGHER SNOW RATIOS ON THE NW SIDE OF THE
DEPARTING LOW...HAVE LINGERED SNOW ACCUMULATIONS A LITTLE IN AREAS
S/E OF COLUMBUS WITH ADVISORY NOW IN EFFECT UNTIL 15Z AS WELL AS
ADDING A COUPLE OF COUNTIES. SHOULD REMAIN A RUSH HOUR IMPACT IN
ESPECIALLY AREAS EAST/SOUTHEAST OF COLUMBUS.
LINGERING NON-ACCUMULATING SNOW SHOWERS TO LINGER BEHIND THE
SYSTEM IN MAINLY THE FAR EASTERN FCST AREA...THEN WEAK SFC RIDGING
BUILDS IN TO THE WEST IN THE 21Z-00Z TIMEFRAME. ONLY LOCATION TO
RECEIVE SOME PARTIAL CLEARING WILL BE IN THE FAR NW AS MID/HIGH
CLOUDS BUILD IN FROM ADVANCING WEAK S/WV FROM THE NORTHERN PLAINS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE GFS/NAM HAVE TRENDED A LITTLE FARTHER WEST IN REGARDS TO A WEAK
S/WV DROPPING SOUTHEAST INTO THE MIDDLE OHIO VALLEY MONDAY NIGHT
INTO TUESDAY. AS SUCH...IT NOW APPEARS THAT THE CHANCE OF LIGHT SNOW
WITH THIS FEATURE MAY JUST GRAZE OUR FAR WEST/SOUTHWEST. HAVE
ADJUSTED THE FORECAST TO REFLECT THIS. THERE WILL BE CONSIDERABLE
CLOUDINESS THROUGH THE PERIOD.
HIGH PRESSURE WILL BRIEFLY BUILD INTO THE AREA TUESDAY NIGHT INTO
WEDNESDAY. COLD TEMPERATURES ON TUESDAY WILL MODIFY SOME BY
WEDNESDAY.
FOR THE PERIOD WEDNESDAY NIGHT INTO THURSDAY NIGHT...THE ECMWF AND
THE GFS DIFFER IN THE TIMING OF A TANDEM OF S/WVS TO AFFECT THE
REGION...ALONG WITH AN ASSOCIATED LOW PRESSURE/COLD FRONT. THE ECMWF
IS SLOWER AND SHARPER WITH THE SECOND S/WV WHILE THE GFS IS FASTER.
HAVE GONE WITH THE GFS TIMING AT THIS TIME TO KEEP CONTINUITY FROM
PREVIOUS FORECAST. WITH RETURN FLOW...TEMPERATURES WILL BEGIN TO
WARM SOME LATE WEDNESDAY NIGHT INTO THURSDAY. THERE WILL BE A RACE
BETWEEN HOW FAST IT WARMS COMPARED TO WHEN THE ONSET OF PCPN BEGINS.
AS STATED YESTERDAY...IT LOOKS LIKE THERE WILL BE SOME MIXED PCPN
(-FZRA/-PL/-SN) EARLY ON BEFORE IT BECOMES RAIN/SNOW MIXED NORTH AND
RAIN SOUTH BY THURSDAY AFTERNOON. GIVEN THAT THIS IS FOUR DAYS OUT
AND IT IS HARD TO PINPOINT THE CHANGING THERMAL FIELDS EVEN IN THE
SHORT TERM...HAVE CONTINUED WITH RAIN/SNOW WORDING ATTM. PCPN SHOULD
CHANGE BACK TO SNOW THURSDAY NIGHT BEFORE ENDING BY FRIDAY MORNING.
FOR FRIDAY INTO FRIDAY NIGHT...HIGH PRESSURE WILL ONCE AGAIN BUILD
INTO THE REGION. TEMPERATURES WILL COOL BACK DOWN TO BELOW SEASONAL
NORMALS.
LONG RANGE MODELS DISAGREE ON HOW FAST A MAJOR WEATHER PATTERN
CHANGE WILL OCCUR OVER THE WEEKEND INTO NEXT WEEK AS MUCH COLDER
ARCTIC AIR PLUNGES SOUTHEAST INTO THE GREAT LAKES AND THE OHIO
VALLEY. HAVE SIDED WITH THE ECMWF ATTM WHICH PUSHES AN ARCTIC FRONT
INTO THE REGION DURING THE SATURDAY/SUNDAY TIME FRAME. WILL FORECAST
A CHANCE OF SNOW WITH THIS SYSTEM.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
CLIPPER SYSTEM WILL CONTINUE TO MOVE THROUGH THE AREA OVERNIGHT
AND INTO THE EARLY DAYTIME HOURS ON MONDAY. SNOW WILL BE PRESENT
AT ALL AREA TAF SITES TO START THE TAF PERIOD. SNOW WILL GRADUALLY
TAPER OFF FROM THE WESTERN TAF SITES TO THE EASTERN TAF SITES.
CIGS WILL GENERALLY BE MVFR OVERNIGHT AND INTO THE DAYTIME MORNING
HOURS ON MONDAY HOWEVER SOME BRIEF IFR CIGS CANNOT BE RULED OUT
OVERNIGHT. VSBYS WITH THE SNOW WILL RANGE FROM IFR TO MVFR. WINDS
WILL GUST AROUND 20 TO 25 KNOTS AT TIMES OVERNIGHT.
HAVE CIGS IMPROVING TO VFR AT KCVG...KLUK...AND KDAY BY MID
DAY ON MONDAY. KILN IS EXPECTED TO RETURN TO VFR CONDITIONS LATER
IN THE DAY ON MONDAY. KCMH AND KLCK ARE EXPECTED TO HAVE MVFR CIGS
THROUGH THE TAF PERIOD.
OUTLOOK...MVFR CIGS AND VSBYS POSSIBLE THURSDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WINTER WEATHER ADVISORY UNTIL 4 AM EST EARLY THIS MORNING FOR
OHZ026-034-035.
WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR
OHZ042>046-051>055-060>064-072.
WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
OHZ056-065-073-074.
KY...NONE.
IN...WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR INZ050.
&&
$$
SYNOPSIS...JDR
NEAR TERM...SITES
SHORT TERM...JDR
LONG TERM...HICKMAN
AVIATION...NOVAK
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
556 PM EST MON JAN 26 2015
.SYNOPSIS...
PERIODS OF LIGHT SNOW WILL DECREASE ACROSS CENTRAL PENNSYLVANIA
TONIGHT AS A STRONG COASTAL STORM TRACKS TOWARDS NEW ENGLAND
TONIGHT. THE COASTAL STORM WILL RAPIDLY INTENSIFY TONIGHT AND
TUESDAY...AS IT TRACKS EAST OF NEW ENGLAND. HIGH PRESSURE WILL
BUILD OVER THE REGION FOR THE MIDDLE OF THE WEEK...FOLLOWED BY AN
ALBERTA CLIPPER THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
600 PM UPDATE...
EXTENDED THE ADVY FOR THOSE MIDDLE SUSQ COUNTIES THRU 11 PM...AS
SNOW IS STILL FALLING AND IS NOT TAPERING OFF AS QUICKLY AS 4KM
NAM/RAP/HRRR HAD PORTRAYED. MDLS CONTINUE TO INDICATE THAT THIS IS
THE FIRST AREA OF THE CWA WHICH WILL HAVE THE SNOW DROP TO
NOTHING. SNOW HAS RE-ENTERED/DEVELOPED OVER THE SE AND CURRENT
NUMBERS STILL LOOK GOOD OVER THE WHOLE REGION.
PREV...
ADDED TIOGA CO TO THE ADVY AS SNOW SHOULD CONTINUE TO FALL THERE
FOR ANOTHER FEW HRS AND THEY ARE ALREADY PUSHING 3-5 INCHES OF
SNOW OFF THEIR CARS. HOWEVER...THE RAP AND HRRR BOTH SLIDE THE BIG
BAND OFF TO THE WEST /NOT EAST/ SLIGHTLY - SO LESSER CHANCE FOR
SULLIVAN CO PA TO GET TOO MUCH MORE. JUST UPPED POPS SLIGHTLY TO
JUST BELOW 101 PERCENT IN THE CENTRAL AND WEST.
PREV...
DEFORMATION BETWEEN THE INVERTED SFC TROF OVER WESTERN AND
SOUTHWESTERN PA AND RAPIDLY DEVELOPING COASTAL LOW OFF OF
SOUTHEAST VA IS MAINTAINING CATEGORICAL POPS/SNOW ACROSS THE
LAURELS AND CENTRAL/WEST CENTRAL/NORTHWEST/NORTHERN MOUNTAINS
PRESENTLY. MY SOUTHEAST COUNTIES HAVE STARTED TO SEE SOME LIGHT
ACTIVITY BUT IT IS STILL REMOVED FROM THE BETTER DEFORMATION
ASSOCIATED WITH THE INVERTED TROF TO THE WEST AND THE INTENSIFYING
LOW TO THE EAST. LOWERED THE LOWER END OF SNOW FAR RANGES FOR THE
EAST IN WSW...GENERALLY 2 TO 5 INCHES EXPECTED OVERALL BEFORE
ACCUM SNOWFALL EXITS PA BY DAYBREAK TUE MORNING.
OVERALL HOWEVER...WIDESPREAD LIGHT SNOW WILL CONTINUE TO FALL OVR
CENTRAL PA THIS EVENING INTO LATE TONIGHT ALONG THE AXIS OF DEEP
EASTERLY FLOW BTWN LOW TO THE SOUTH AND HIGH PRES OVR NEW
ENGLAND...FORCED LOCALLY BY THE INCREASING AFOREMENTIONED
DEFORMATION. HI RES NAM/HRRR/WRF ARW ALL SUPPORT AN ADDITIONAL 1-3
INCHES TODAY...WITH THE HIGHEST AMTS ACROSS THE CENTRAL
MTNS/ALLEGHENIES. KEEPING HEADLINES AS IS FOR NOW BUT SOME MAY
NEED TO BE EXTENDED OVERNIGHT DEPENDING UPON WHERE THE DEFORMATION
PROPOGATES. HRRR INDICATES A SOUTHWEST SHIFT TO THE FORCING AFTER
03Z...AS THE PARENT COASTAL CIRCULATION DOMINATES AND TAKES OVER
EFFECTIVELY DISRUPTING AND ELIMINATING THE DEFORMATION FORCING
SNOWFALL OVER CENTRAL PA BY 12Z.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
AS MENTIONED ABOVE...DEFORMATION SNOW SHOWERS SHOULD DWINDLE EARLY
TUESDAY...WHILE NNW FLOW IN WAKE OF DEPARTING COASTAL LOW DRAWS
MUCH DRIER AIR INTO CENTRAL PA. 25 TO 35KT NE WIND GUSTS WILL BE
FELT AS TIGHT PRES GRADIENT IS REALIZED IN WAKE OF STORM JUST
OFFSHORE OF SOUTHERN NEW ENGLAND COAST. AS PREVIOUSLY
MENTIONED...THERE IS THE POTENTIAL OF SOME BLOWING/DRIFTING...ESP
EASTERN PA WHERE BUKFIT SOUNDINGS SUPPORT GUSTS BTWN 30-35KTS. ENS
MEAN 925 TEMPS SUPPORT MAX TEMPS TUE FROM NR 20F OVR THE N
MTNS...TO ARND 32F ACROSS THE LOWER SUSQ VALLEY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
DEEP STORM WILL PULL AWAY FROM PA TUESDAY NIGHT. WITH WINDS
FROM THE NORTH...TOOK OUT SNOW SHOWERS FOR JST.
SKIES SHOULD CLEAR OUT BY WED MORNING.
MAIN CHANGE WAS WED NIGHT...DID LOWER TEMPS...BASED ON 12Z
MODEL RUNS...AND THAT WITH MAINLY CLEAR SKIES AND LIGHT
WINDS...EXPECT TEMPS TO DROP...WITH FRESH SNOW COVER.
NEXT SYSTEM WILL BRING SOME SNOW SHOWERS TO THE AREA LATER THU
INTO FRIDAY. THIS SYSTEM NOT LOOKING LIKE IT WOULD RESULT IN
A COASTAL REAL NEAR THE COAST.
COLDER AIR FOR FRIDAY NIGHT.
WEEKEND NOT LOOKING TOO BAD...COLDER AIR WILL TRY TO BUILD IN
EARLY NEXT WEEK.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
SENT OUT MORE ADJUSTMENTS AT 22Z.
NW TO SE BANDS OF SNOW STILL LIFTING NORTHWARD FROM NEAR BWI.
EARLIER DISCUSSION BELOW.
REDUCTIONS CONTINUE REGIONWIDE AS INVERTED TROUGH LINGERS OVER
CENTRAL PA /AND AS DEVELOPING NOR`EASTER BEGINS TO DEEPEN OFF MID
ATLANTIC COAST/. EXPECT WIDESPREAD LIGHT SNOW TO CONTINUE THIS
INTO TONIGHT WITH VSBYS VARYING FROM 1-4SM AND CIGS OF MVFR- IFR
SETTLING BACK TOWARD A MORE ROBUST IFR DECK. NE WINDS WILL BE
AROUND 10 MPH TODAY...AND PICK UP A BIT TO 10-15 MPH IN THE LOWER
SUSQ TONIGHT AS STORM DEEPENS TO THE EAST AND SYNOPTIC FLOW
INCREASES.
IMPROVING CONDITIONS ON TUES AS HIGH PRESSURE BUILDS IN. SHOULD
SEE VFR CONDITIONS IN CENTRAL AND EAST...WITH MVFR CIGS IN NW FLOW
UNDER SUBSIDENCE INVERSION IN THE WESTERN HIGHER TERRAIN. NORTH
WIND WILL BE BREEZY...PRODUCING SPEEDS OF 10-20 MPH.
OUTLOOK...
WED...VFR WITH NO SIG WEATHER EXPECTED.
THU...VFR TO START...WITH LATE DAY RESTRICTIONS SPREADING IN FROM
THE WEST.
THU NIGHT-FRI...WIDESPREAD IFR/MVFR IN SNOW.
SAT...MAINLY VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR PAZ004>006-
010>012-017>019-024>026-033>036-045-058-059-064>066.
WINTER WEATHER ADVISORY UNTIL 11 PM EST THIS EVENING FOR
PAZ027-028-037-041-046-049>053-056-057-063.
&&
$$
SYNOPSIS...DEVOIR/FITZGERALD
NEAR TERM...DANGELO/DEVOIR/FITZGERALD
SHORT TERM...DEVOIR/FITZGERALD
LONG TERM...MARTIN
AVIATION...DEVOIR/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
515 PM EST MON JAN 26 2015
.SYNOPSIS...
PERIODS OF LIGHT SNOW WILL DECREASE ACROSS CENTRAL PENNSYLVANIA
TONIGHT AS A STRONG COASTAL STORM TRACKS TOWARDS NEW ENGLAND
TONIGHT. THE COASTAL STORM WILL RAPIDLY INTENSIFY TONIGHT AND
TUESDAY...AS IT TRACKS EAST OF NEW ENGLAND. HIGH PRESSURE WILL
BUILD OVER THE REGION FOR THE MIDDLE OF THE WEEK...FOLLOWED BY AN
ALBERTA CLIPPER THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
ADDED TIOGA CO TO THE ADVY AS SNOW SHOULD CONTINUE TO FALL THERE
FOR ANOTHER FEW HRS AND THEY ARE ALREADY PUSHING 3-5 INCHES OF
SNOW OFF THEIR CARS. HOWEVER...THE RAP AND HRRR BOTH SLIDE THE BIG
BAND OFF TO THE WEST /NOT EAST/ SLIGHTLY - SO LESSER CHANCE FOR
SULLIVAN CO PA TO GET TOO MUCH MORE. JUST UPPED POPS SLIGHTLY TO
JUST BELOW 101 PERCENT IN THE CENTRAL AND WEST.
PREV...
DEFORMATION BETWEEN THE INVERTED SFC TROF OVER WESTERN AND
SOUTHWESTERN PA AND RAPIDLY DEVELOPING COASTAL LOW OFF OF
SOUTHEAST VA IS MAINTAINING CATEGORICAL POPS/SNOW ACROSS THE
LAURELS AND CENTRAL/WEST CENTRAL/NORTHWEST/NORTHERN MOUNTAINS
PRESENTLY. MY SOUTHEAST COUNTIES HAVE STARTED TO SEE SOME LIGHT
ACTIVITY BUT IT IS STILL REMOVED FROM THE BETTER DEFORMATION
ASSOCIATED WITH THE INVERTED TROF TO THE WEST AND THE INTENSIFYING
LOW TO THE EAST. LOWERED THE LOWER END OF SNOW FAR RANGES FOR THE
EAST IN WSW...GENERALLY 2 TO 5 INCHES EXPECTED OVERALL BEFORE
ACCUM SNOWFALL EXITS PA BY DAYBREAK TUE MORNING.
OVERALL HOWEVER...WIDESPREAD LIGHT SNOW WILL CONTINUE TO FALL OVR
CENTRAL PA THIS EVENING INTO LATE TONIGHT ALONG THE AXIS OF DEEP
EASTERLY FLOW BTWN LOW TO THE SOUTH AND HIGH PRES OVR NEW
ENGLAND...FORCED LOCALLY BY THE INCREASING AFOREMENTIONED
DEFORMATION. HI RES NAM/HRRR/WRF ARW ALL SUPPORT AN ADDITIONAL 1-3
INCHES TODAY...WITH THE HIGHEST AMTS ACROSS THE CENTRAL
MTNS/ALLEGHENIES. KEEPING HEADLINES AS IS FOR NOW BUT SOME MAY
NEED TO BE EXTENDED OVERNIGHT DEPENDING UPON WHERE THE DEFORMATION
PROPOGATES. HRRR INDICATES A SOUTHWEST SHIFT TO THE FORCING AFTER
03Z...AS THE PARENT COASTAL CIRCULATION DOMINATES AND TAKES OVER
EFFECTIVELY DISRUPTING AND ELIMINATING THE DEFORMATION FORCING
SNOWFALL OVER CENTRAL PA BY 12Z.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
AS MENTIONED ABOVE...DEFORMATION SNOW SHOWERS SHOULD DWINDLE EARLY
TUESDAY...WHILE NNW FLOW IN WAKE OF DEPARTING COASTAL LOW DRAWS
MUCH DRIER AIR INTO CENTRAL PA. 25 TO 35KT NE WIND GUSTS WILL BE
FELT AS TIGHT PRES GRADIENT IS REALIZED IN WAKE OF STORM JUST
OFFSHORE OF SOUTHERN NEW ENGLAND COAST. AS PREVIOUSLY
MENTIONED...THERE IS THE POTENTIAL OF SOME BLOWING/DRIFTING...ESP
EASTERN PA WHERE BUKFIT SOUNDINGS SUPPORT GUSTS BTWN 30-35KTS. ENS
MEAN 925 TEMPS SUPPORT MAX TEMPS TUE FROM NR 20F OVR THE N
MTNS...TO ARND 32F ACROSS THE LOWER SUSQ VALLEY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
DEEP STORM WILL PULL AWAY FROM PA TUESDAY NIGHT. WITH WINDS
FROM THE NORTH...TOOK OUT SNOW SHOWERS FOR JST.
SKIES SHOULD CLEAR OUT BY WED MORNING.
MAIN CHANGE WAS WED NIGHT...DID LOWER TEMPS...BASED ON 12Z
MODEL RUNS...AND THAT WITH MAINLY CLEAR SKIES AND LIGHT
WINDS...EXPECT TEMPS TO DROP...WITH FRESH SNOW COVER.
NEXT SYSTEM WILL BRING SOME SNOW SHOWERS TO THE AREA LATER THU
INTO FRIDAY. THIS SYSTEM NOT LOOKING LIKE IT WOULD RESULT IN
A COASTAL REAL NEAR THE COAST.
COLDER AIR FOR FRIDAY NIGHT.
WEEKEND NOT LOOKING TOO BAD...COLDER AIR WILL TRY TO BUILD IN
EARLY NEXT WEEK.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
SENT OUT MORE ADJUSTMENTS AT 22Z.
NW TO SE BANDS OF SNOW STILL LIFTING NORTHWARD FROM NEAR BWI.
EARLIER DISCUSSION BELOW.
REDUCTIONS CONTINUE REGIONWIDE AS INVERTED TROUGH LINGERS OVER
CENTRAL PA /AND AS DEVELOPING NOR`EASTER BEGINS TO DEEPEN OFF MID
ATLANTIC COAST/. EXPECT WIDESPREAD LIGHT SNOW TO CONTINUE THIS
INTO TONIGHT WITH VSBYS VARYING FROM 1-4SM AND CIGS OF MVFR- IFR
SETTLING BACK TOWARD A MORE ROBUST IFR DECK. NE WINDS WILL BE
AROUND 10 MPH TODAY...AND PICK UP A BIT TO 10-15 MPH IN THE LOWER
SUSQ TONIGHT AS STORM DEEPENS TO THE EAST AND SYNOPTIC FLOW
INCREASES.
IMPROVING CONDITIONS ON TUES AS HIGH PRESSURE BUILDS IN. SHOULD
SEE VFR CONDITIONS IN CENTRAL AND EAST...WITH MVFR CIGS IN NW FLOW
UNDER SUBSIDENCE INVERSION IN THE WESTERN HIGHER TERRAIN. NORTH
WIND WILL BE BREEZY...PRODUCING SPEEDS OF 10-20 MPH.
OUTLOOK...
WED...VFR WITH NO SIG WEATHER EXPECTED.
THU...VFR TO START...WITH LATE DAY RESTRICTIONS SPREADING IN FROM
THE WEST.
THU NIGHT-FRI...WIDESPREAD IFR/MVFR IN SNOW.
SAT...MAINLY VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR PAZ004>006-
010>012-017>019-024>026-033>036-045-058-059-064>066.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ027-
028-037-041-046-049>053-056-057-063.
&&
$$
SYNOPSIS...DEVOIR/FITZGERALD
NEAR TERM...DANGELO/DEVOIR/FITZGERALD
SHORT TERM...DEVOIR/FITZGERALD
LONG TERM...MARTIN
AVIATION...DEVOIR/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
433 PM EST MON JAN 26 2015
.SYNOPSIS...
PERIODS OF LIGHT SNOW WILL DECREASE ACROSS CENTRAL PENNSYLVANIA
TONIGHT AS A STRONG COASTAL STORM TRACKS TOWARDS NEW ENGLAND
TONIGHT. THE COASTAL STORM WILL RAPIDLY INTENSIFY TONIGHT AND
TUESDAY...AS IT TRACKS EAST OF NEW ENGLAND. HIGH PRESSURE WILL
BUILD OVER THE REGION FOR THE MIDDLE OF THE WEEK...FOLLOWED BY AN
ALBERTA CLIPPER THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
ADDED TIOGA CO TO THE ADVY AS SNOW SHOULD CONTINUE TO FALL THERE
FOR ANOTHER FEW HRS AND THEY ARE ALREADY PUSHING 3-5 INCHES OF
SNOW OFF THEIR CARS. HOWEVER...THE RAP AND HRRR BOTH SLIDE THE BIG
BAND OFF TO THE WEST /NOT EAST/ SLIGHTLY - SO LESSER CHANCE FOR
SULLIVAN CO PA TO GET TOO MUCH MORE. JUST UPPED POPS SLIGHTLY TO
JUST BELOW 101 PERCENT IN THE CENTRAL AND WEST.
PREV...
DEFORMATION BETWEEN THE INVERTED SFC TROF OVER WESTERN AND
SOUTHWESTERN PA AND RAPIDLY DEVELOPING COASTAL LOW OFF OF
SOUTHEAST VA IS MAINTAINING CATEGORICAL POPS/SNOW ACROSS THE
LAURELS AND CENTRAL/WEST CENTRAL/NORTHWEST/NORTHERN MOUNTAINS
PRESENTLY. MY SOUTHEAST COUNTIES HAVE STARTED TO SEE SOME LIGHT
ACTIVITY BUT IT IS STILL REMOVED FROM THE BETTER DEFORMATION
ASSOCIATED WITH THE INVERTED TROF TO THE WEST AND THE INTENSIFYING
LOW TO THE EAST. LOWERED THE LOWER END OF SNOW FAR RANGES FOR THE
EAST IN WSW...GENERALLY 2 TO 5 INCHES EXPECTED OVERALL BEFORE
ACCUM SNOWFALL EXITS PA BY DAYBREAK TUE MORNING.
OVERALL HOWEVER...WIDESPREAD LIGHT SNOW WILL CONTINUE TO FALL OVR
CENTRAL PA THIS EVENING INTO LATE TONIGHT ALONG THE AXIS OF DEEP
EASTERLY FLOW BTWN LOW TO THE SOUTH AND HIGH PRES OVR NEW
ENGLAND...FORCED LOCALLY BY THE INCREASING AFOREMENTIONED
DEFORMATION. HI RES NAM/HRRR/WRF ARW ALL SUPPORT AN ADDITIONAL 1-3
INCHES TODAY...WITH THE HIGHEST AMTS ACROSS THE CENTRAL
MTNS/ALLEGHENIES. KEEPING HEADLINES AS IS FOR NOW BUT SOME MAY
NEED TO BE EXTENDED OVERNIGHT DEPENDING UPON WHERE THE DEFORMATION
PROPOGATES. HRRR INDICATES A SOUTHWEST SHIFT TO THE FORCING AFTER
03Z...AS THE PARENT COASTAL CIRCULATION DOMINATES AND TAKES OVER
EFFECTIVELY DISRUPTING AND ELIMINATING THE DEFORMATION FORCING
SNOWFALL OVER CENTRAL PA BY 12Z.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
AS MENTIONED ABOVE...DEFORMATION SNOW SHOWERS SHOULD DWINDLE EARLY
TUESDAY...WHILE NNW FLOW IN WAKE OF DEPARTING COASTAL LOW DRAWS
MUCH DRIER AIR INTO CENTRAL PA. 25 TO 35KT NE WIND GUSTS WILL BE
FELT AS TIGHT PRES GRADIENT IS REALIZED IN WAKE OF STORM JUST
OFFSHORE OF SOUTHERN NEW ENGLAND COAST. AS PREVIOUSLY
MENTIONED...THERE IS THE POTENTIAL OF SOME BLOWING/DRIFTING...ESP
EASTERN PA WHERE BUKFIT SOUNDINGS SUPPORT GUSTS BTWN 30-35KTS. ENS
MEAN 925 TEMPS SUPPORT MAX TEMPS TUE FROM NR 20F OVR THE N
MTNS...TO ARND 32F ACROSS THE LOWER SUSQ VALLEY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
DEEP STORM WILL PULL AWAY FROM PA TUESDAY NIGHT. WITH WINDS
FROM THE NORTH...TOOK OUT SNOW SHOWERS FOR JST.
SKIES SHOULD CLEAR OUT BY WED MORNING.
MAIN CHANGE WAS WED NIGHT...DID LOWER TEMPS...BASED ON 12Z
MODEL RUNS...AND THAT WITH MAINLY CLEAR SKIES AND LIGHT
WINDS...EXPECT TEMPS TO DROP...WITH FRESH SNOW COVER.
NEXT SYSTEM WILL BRING SOME SNOW SHOWERS TO THE AREA LATER THU
INTO FRIDAY. THIS SYSTEM NOT LOOKING LIKE IT WOULD RESULT IN
A COASTAL REAL NEAR THE COAST.
COLDER AIR FOR FRIDAY NIGHT.
WEEKEND NOT LOOKING TOO BAD...COLDER AIR WILL TRY TO BUILD IN
EARLY NEXT WEEK.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
REDUCTIONS CONTINUE REGIONWIDE AS INVERTED TROUGH LINGERS OVER
CENTRAL PA /AND AS DEVELOPING NOR`EASTER BEGINS TO DEEPEN OFF MID
ATLANTIC COAST/. EXPECT WIDESPREAD LIGHT SNOW TO CONTINUE THIS
INTO TONIGHT WITH VSBYS VARYING FROM 1-4SM AND CIGS OF MVFR- IFR
SETTLING BACK TOWARD A MORE ROBUST IFR DECK. NE WINDS WILL BE
AROUND 10 MPH TODAY...AND PICK UP A BIT TO 10-15 MPH IN THE LOWER
SUSQ TONIGHT AS STORM DEEPENS TO THE EAST AND SYNOPTIC FLOW
INCREASES.
IMPROVING CONDITIONS ON TUES AS HIGH PRESSURE BUILDS IN. SHOULD
SEE VFR CONDITIONS IN CENTRAL AND EAST...WITH MVFR CIGS IN NW FLOW
UNDER SUBSIDENCE INVERSION IN THE WESTERN HIGHER TERRAIN. NORTH
WIND WILL BE BREEZY...PRODUCING SPEEDS OF 10-20 MPH.
OUTLOOK...
WED...VFR WITH NO SIG WEATHER EXPECTED.
THU...VFR TO START...WITH LATE DAY RESTRICTIONS SPREADING IN FROM
THE WEST.
THU NIGHT-FRI...WIDESPREAD IFR/MVFR IN SNOW.
SAT...MAINLY VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR PAZ004>006-
010>012-017>019-024>026-033>036-045-058-059-064>066.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ027-
028-037-041-046-049>053-056-057-063.
&&
$$
SYNOPSIS...DEVOIR/FITZGERALD
NEAR TERM...DANGELO/DEVOIR/FITZGERALD
SHORT TERM...DEVOIR/FITZGERALD
LONG TERM...MARTIN
AVIATION...DEVOIR/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
432 PM EST MON JAN 26 2015
.SYNOPSIS...
PERIODS OF LIGHT SNOW WILL DECREASE ACROSS CENTRAL PENNSYLVANIA
TONIGHT AS A STRONG COASTAL STORM TRACKS TOWARDS NEW ENGLAND
TONIGHT. THE COASTAL STORM WILL RAPIDLY INTENSIFY TONIGHT AND
TUESDAY...AS IT TRACKS EAST OF NEW ENGLAND. HIGH PRESSURE WILL
BUILD OVER THE REGION FOR THE MIDDLE OF THE WEEK...FOLLOWED BY AN
ALBERTA CLIPPER THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
ADDED TIOGA CO TO THE ADVY AS SNOW SHOULD CONTINUE TO FALL THERE
FOR ANOTHER FEW HRS AND THEY ARE ALREADY PUSHING 3-5 INCHES OF
SNOW OFF THEIR CARS. HOWEVER...THE RAP AND HRRR BOTH SLIDE THE BIG
BAND OFF TO THE EAST SLIGHTLY - SO LESSER CHANCE FOR SULLIVAN CO
PA TO GET TOO MUCH MORE. JUST UPPED POPS SLIGHTLY TO JUST BELOW
101 PERCENT IN THE CENTRAL AND WEST.
PREV...
DEFORMATION BETWEEN THE INVERTED SFC TROF OVER WESTERN AND
SOUTHWESTERN PA AND RAPIDLY DEVELOPING COASTAL LOW OFF OF
SOUTHEAST VA IS MAINTAINING CATEGORICAL POPS/SNOW ACROSS THE
LAURELS AND CENTRAL/WEST CENTRAL/NORTHWEST/NORTHERN MOUNTAINS
PRESENTLY. MY SOUTHEAST COUNTIES HAVE STARTED TO SEE SOME LIGHT
ACTIVITY BUT IT IS STILL REMOVED FROM THE BETTER DEFORMATION
ASSOCIATED WITH THE INVERTED TROF TO THE WEST AND THE INTENSIFYING
LOW TO THE EAST. LOWERED THE LOWER END OF SNOW FAR RANGES FOR THE
EAST IN WSW...GENERALLY 2 TO 5 INCHES EXPECTED OVERALL BEFORE
ACCUM SNOWFALL EXITS PA BY DAYBREAK TUE MORNING.
OVERALL HOWEVER...WIDESPREAD LIGHT SNOW WILL CONTINUE TO FALL OVR
CENTRAL PA THIS EVENING INTO LATE TONIGHT ALONG THE AXIS OF DEEP
EASTERLY FLOW BTWN LOW TO THE SOUTH AND HIGH PRES OVR NEW
ENGLAND...FORCED LOCALLY BY THE INCREASING AFOREMENTIONED
DEFORMATION. HI RES NAM/HRRR/WRF ARW ALL SUPPORT AN ADDITIONAL 1-3
INCHES TODAY...WITH THE HIGHEST AMTS ACROSS THE CENTRAL
MTNS/ALLEGHENIES. KEEPING HEADLINES AS IS FOR NOW BUT SOME MAY
NEED TO BE EXTENDED OVERNIGHT DEPENDING UPON WHERE THE DEFORMATION
PROPOGATES. HRRR INDICATES A SOUTHWEST SHIFT TO THE FORCING AFTER
03Z...AS THE PARENT COASTAL CIRCULATION DOMINATES AND TAKES OVER
EFFECTIVELY DISRUPTING AND ELIMINATING THE DEFORMATION FORCING
SNOWFALL OVER CENTRAL PA BY 12Z.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
AS MENTIONED ABOVE...DEFORMATION SNOW SHOWERS SHOULD DWINDLE EARLY
TUESDAY...WHILE NNW FLOW IN WAKE OF DEPARTING COASTAL LOW DRAWS
MUCH DRIER AIR INTO CENTRAL PA. 25 TO 35KT NE WIND GUSTS WILL BE
FELT AS TIGHT PRES GRADIENT IS REALIZED IN WAKE OF STORM JUST
OFFSHORE OF SOUTHERN NEW ENGLAND COAST. AS PREVIOUSLY
MENTIONED...THERE IS THE POTENTIAL OF SOME BLOWING/DRIFTING...ESP
EASTERN PA WHERE BUKFIT SOUNDINGS SUPPORT GUSTS BTWN 30-35KTS. ENS
MEAN 925 TEMPS SUPPORT MAX TEMPS TUE FROM NR 20F OVR THE N
MTNS...TO ARND 32F ACROSS THE LOWER SUSQ VALLEY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
DEEP STORM WILL PULL AWAY FROM PA TUESDAY NIGHT. WITH WINDS
FROM THE NORTH...TOOK OUT SNOW SHOWERS FOR JST.
SKIES SHOULD CLEAR OUT BY WED MORNING.
MAIN CHANGE WAS WED NIGHT...DID LOWER TEMPS...BASED ON 12Z
MODEL RUNS...AND THAT WITH MAINLY CLEAR SKIES AND LIGHT
WINDS...EXPECT TEMPS TO DROP...WITH FRESH SNOW COVER.
NEXT SYSTEM WILL BRING SOME SNOW SHOWERS TO THE AREA LATER THU
INTO FRIDAY. THIS SYSTEM NOT LOOKING LIKE IT WOULD RESULT IN
A COASTAL REAL NEAR THE COAST.
COLDER AIR FOR FRIDAY NIGHT.
WEEKEND NOT LOOKING TOO BAD...COLDER AIR WILL TRY TO BUILD IN
EARLY NEXT WEEK.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
REDUCTIONS CONTINUE REGIONWIDE AS INVERTED TROUGH LINGERS OVER
CENTRAL PA /AND AS DEVELOPING NOR`EASTER BEGINS TO DEEPEN OFF MID
ATLANTIC COAST/. EXPECT WIDESPREAD LIGHT SNOW TO CONTINUE THIS
INTO TONIGHT WITH VSBYS VARYING FROM 1-4SM AND CIGS OF MVFR- IFR
SETTLING BACK TOWARD A MORE ROBUST IFR DECK. NE WINDS WILL BE
AROUND 10 MPH TODAY...AND PICK UP A BIT TO 10-15 MPH IN THE LOWER
SUSQ TONIGHT AS STORM DEEPENS TO THE EAST AND SYNOPTIC FLOW
INCREASES.
IMPROVING CONDITIONS ON TUES AS HIGH PRESSURE BUILDS IN. SHOULD
SEE VFR CONDITIONS IN CENTRAL AND EAST...WITH MVFR CIGS IN NW FLOW
UNDER SUBSIDENCE INVERSION IN THE WESTERN HIGHER TERRAIN. NORTH
WIND WILL BE BREEZY...PRODUCING SPEEDS OF 10-20 MPH.
OUTLOOK...
WED...VFR WITH NO SIG WEATHER EXPECTED.
THU...VFR TO START...WITH LATE DAY RESTRICTIONS SPREADING IN FROM
THE WEST.
THU NIGHT-FRI...WIDESPREAD IFR/MVFR IN SNOW.
SAT...MAINLY VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR PAZ004>006-
010>012-017>019-024>026-033>036-045-058-059-064>066.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ027-
028-037-041-046-049>053-056-057-063.
&&
$$
SYNOPSIS...DEVOIR/FITZGERALD
NEAR TERM...DANGELO/DEVOIR/FITZGERALD
SHORT TERM...DEVOIR/FITZGERALD
LONG TERM...MARTIN
AVIATION...DEVOIR/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
334 PM EST MON JAN 26 2015
.SYNOPSIS...
PERIODS OF LIGHT SNOW WILL DECREASE ACROSS CENTRAL PENNSYLVANIA
TONIGHT AS A STRONG COASTAL STORM TRACKS TOWARDS NEW ENGLAND
TONIGHT. THE COASTAL STORM WILL RAPIDLY INTENSIFY TONIGHT AND
TUESDAY...AS IT TRACKS EAST OF NEW ENGLAND. HIGH PRESSURE WILL
BUILD OVER THE REGION FOR THE MIDDLE OF THE WEEK...FOLLOWED BY AN
ALBERTA CLIPPER THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
DEFORMATION BETWEEN THE INVERTED SFC TROF OVER WESTERN AND
SOUTHWESTERN PA AND RAPIDLY DEVELOPING COASTAL LOW OFF OF
SOUTHEAST VA IS MAINTAINING CATEGORICAL POPS/SNOW ACROSS THE
LAURELS AND CENTRAL/WEST CENTRAL/NORTHWEST/NORTHERN MOUNTAINS
PRESENTLY. MY SOUTHEAST COUNTIES HAVE STARTED TO SEE SOME LIGHT
ACTIVITY BUT IT IS STILL REMOVED FROM THE BETTER DEFORMATION
ASSOCIATED WITH THE INVERTED TROF TO THE WEST AND THE INTENSIFYING
LOW TO THE EAST. LOWERED THE LOWER END OF SNOW FAR RANGES FOR THE
EAST IN WSW...GENERALLY 2 TO 5 INCHES EXPECTED OVERALL BEFORE
ACCUM SNOWFALL EXITS PA BY DAYBREAK TUE MORNING.
OVERALL HOWEVER...WIDESPREAD LIGHT SNOW WILL CONTINUE TO FALL OVR
CENTRAL PA THIS EVENING INTO LATE TONIGHT ALONG THE AXIS OF DEEP
EASTERLY FLOW BTWN LOW TO THE SOUTH AND HIGH PRES OVR NEW
ENGLAND...FORCED LOCALLY BY THE INCREASING AFOREMENTIONED
DEFORMATION. HI RES NAM/HRRR/WRF ARW ALL SUPPORT AN ADDITIONAL 1-3
INCHES TODAY...WITH THE HIGHEST AMTS ACROSS THE CENTRAL
MTNS/ALLEGHENIES. KEEPING HEADLINES AS IS FOR NOW BUT SOME MAY
NEED TO BE EXTENDED OVERNIGHT DEPENDING UPON WHERE THE DEFORMATION
PROPOGATES. HRRR INDICATES A SOUTHWEST SHIFT TO THE FORCING AFTER
03Z...AS THE PARENT COASTAL CIRCULATION DOMINATES AND TAKES OVER
EFFECTIVELY DISRUPTING AND ELIMINATING THE DEFORMATION FORCING
SNOWFALL OVER CENTRAL PA BY 12Z.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
AS MENTIONED ABOVE...DEFORMATION SNOW SHOWERS SHOULD DWINDLE EARLY
TUESDAY...WHILE NNW FLOW IN WAKE OF DEPARTING COASTAL LOW DRAWS
MUCH DRIER AIR INTO CENTRAL PA. 25 TO 35KT NE WIND GUSTS WILL BE
FELT AS TIGHT PRES GRADIENT IS REALIZED IN WAKE OF STORM JUST
OFFSHORE OF SOUTHERN NEW ENGLAND COAST. AS PREVIOUSLY
MENTIONED...THERE IS THE POTENTIAL OF SOME BLOWING/DRIFTING...ESP
EASTERN PA WHERE BUKFIT SOUNDINGS SUPPORT GUSTS BTWN 30-35KTS. ENS
MEAN 925 TEMPS SUPPORT MAX TEMPS TUE FROM NR 20F OVR THE N
MTNS...TO ARND 32F ACROSS THE LOWER SUSQ VALLEY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
DEEP STORM WILL PULL AWAY FROM PA TUESDAY NIGHT. WITH WINDS
FROM THE NORTH...TOOK OUT SNOW SHOWERS FOR JST.
SKIES SHOULD CLEAR OUT BY WED MORNING.
MAIN CHANGE WAS WED NIGHT...DID LOWER TEMPS...BASED ON 12Z
MODEL RUNS...AND THAT WITH MAINLY CLEAR SKIES AND LIGHT
WINDS...EXPECT TEMPS TO DROP...WITH FRESH SNOW COVER.
NEXT SYSTEM WILL BRING SOME SNOW SHOWERS TO THE AREA LATER THU
INTO FRIDAY. THIS SYSTEM NOT LOOKING LIKE IT WOULD RESULT IN
A COASTAL REAL NEAR THE COAST.
COLDER AIR FOR FRIDAY NIGHT.
WEEKEND NOT LOOKING TOO BAD...COLDER AIR WILL TRY TO BUILD IN
EARLY NEXT WEEK.
&&
.AVIATION /21Z MONDAY THROUGH SATURDAY/...
REDUCTIONS CONTINUE REGIONWIDE AS INVERTED TROUGH LINGERS OVER
CENTRAL PA /AND AS DEVELOPING NOR`EASTER BEGINS TO DEEPEN OFF MID
ATLANTIC COAST/. EXPECT WIDESPREAD LIGHT SNOW TO CONTINUE THIS
INTO TONIGHT WITH VSBYS VARYING FROM 1-4SM AND CIGS OF MVFR- IFR
SETTLING BACK TOWARD A MORE ROBUST IFR DECK. NE WINDS WILL BE
AROUND 10 MPH TODAY...AND PICK UP A BIT TO 10-15 MPH IN THE LOWER
SUSQ TONIGHT AS STORM DEEPENS TO THE EAST AND SYNOPTIC FLOW
INCREASES.
IMPROVING CONDITIONS ON TUES AS HIGH PRESSURE BUILDS IN. SHOULD
SEE VFR CONDITIONS IN CENTRAL AND EAST...WITH MVFR CIGS IN NW FLOW
UNDER SUBSIDENCE INVERSION IN THE WESTERN HIGHER TERRAIN. NORTH
WIND WILL BE BREEZY...PRODUCING SPEEDS OF 10-20 MPH.
OUTLOOK...
WED...VFR WITH NO SIG WEATHER EXPECTED.
THU...VFR TO START...WITH LATE DAY RESTRICTIONS SPREADING IN FROM
THE WEST.
THU NIGHT-FRI...WIDESPREAD IFR/MVFR IN SNOW.
SAT...MAINLY VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR PAZ004>006-
010>012-017>019-024>026-033>036-045-058-059-064>066.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ027-
028-041-046-049>053-056-057-063.
&&
$$
SYNOPSIS...DEVOIR/FITZGERALD
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...DEVOIR/FITZGERALD
LONG TERM...MARTIN
AVIATION...DEVOIR/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
245 PM EST MON JAN 26 2015
.SYNOPSIS...
PERIODS OF LIGHT SNOW WILL DECREASE ACROSS CENTRAL PENNSYLVANIA
TONIGHT AS A STRONG COASTAL STORM TRACKS TOWARDS NEW ENGLAND
TONIGHT. THE COASTAL STORM WILL RAPIDLY INTENSIFY TONIGHT AND
TUESDAY...AS IT TRACKS EAST OF NEW ENGLAND. HIGH PRESSURE WILL
BUILD OVER THE REGION FOR THE MIDDLE OF THE WEEK...FOLLOWED BY AN
ALBERTA CLIPPER THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
DEFORMATION BETWEEN THE INVERTED SFC TROF OVER WESTERN AND
SOUTHWESTERN PA AND RAPIDLY DEVELOPING COASTAL LOW OFF OF
SOUTHEAST VA IS MAINTAINING CATEGORICAL POPS/SNOW ACROSS THE
LAURELS AND CENTRAL/WEST CENTRAL/NORTHWEST/NORTHERN MOUNTAINS
PRESENTLY. MY SOUTHEAST COUNTIES HAVE STARTED TO SEE SOME LIGHT
ACTIVITY BUT IT IS STILL REMOVED FROM THE BETTER DEFORMATION
ASSOCIATED WITH THE INVERTED TROF TO THE WEST AND THE INTENSIFYING
LOW TO THE EAST. LOWERED THE LOWER END OF SNOW FAR RANGES FOR THE
EAST IN WSW...GENERALLY 2 TO 5 INCHES EXPECTED OVERALL BEFORE
ACCUM SNOWFALL EXITS PA BY DAYBREAK TUE MORNING.
OVERALL HOWEVER...WIDESPREAD LIGHT SNOW WILL CONTINUE TO FALL OVR
CENTRAL PA THIS EVENING INTO LATE TONIGHT ALONG THE AXIS OF DEEP
EASTERLY FLOW BTWN LOW TO THE SOUTH AND HIGH PRES OVR NEW
ENGLAND...FORCED LOCALLY BY THE INCREASING AFOREMENTIONED
DEFORMATION. HI RES NAM/HRRR/WRF ARW ALL SUPPORT AN ADDITIONAL 1-3
INCHES TODAY...WITH THE HIGHEST AMTS ACROSS THE CENTRAL
MTNS/ALLEGHENIES. KEEPING HEADLINES AS IS FOR NOW BUT SOME MAY
NEED TO BE EXTENDED OVERNIGHT DEPENDING UPON WHERE THE DEFORMATION
PROPOGATES. HRRR INDICATES A SOUTHWEST SHIFT TO THE FORCING AFTER
03Z...AS THE PARENT COASTAL CIRCULATION DOMINATES AND TAKES OVER
EFFECTIVELY DISRUPTING AND ELIMINATING THE DEFORMATION FORCING
SNOWFALL OVER CENTRAL PA BY 12Z.
&&
.SHORT TERM /TUESDAY/...
AS MENTIONED ABOVE...DEFORMATION SNOW SHOWERS SHOULD DWINDLE EARLY
TUESDAY...WHILE NNW FLOW IN WAKE OF DEPARTING COASTAL LOW DRAWS
MUCH DRIER AIR INTO CENTRAL PA. 25 TO 35KT NE WIND GUSTS WILL BE
FELT AS TIGHT PRES GRADIENT IS REALIZED IN WAKE OF STORM JUST
OFFSHORE OF SOUTHERN NEW ENGLAND COAST. AS PREVIOUSLY
MENTIONED...THERE IS THE POTENTIAL OF SOME BLOWING/DRIFTING...ESP
EASTERN PA WHERE BUKFIT SOUNDINGS SUPPORT GUSTS BTWN 30-35KTS. ENS
MEAN 925 TEMPS SUPPORT MAX TEMPS TUE FROM NR 20F OVR THE N
MTNS...TO ARND 32F ACROSS THE LOWER SUSQ VALLEY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
FAIR AND CHILLY WED EXPECTED WED...AS HIGH PRES BUILDS OVR THE
AREA. MED RANGE GUIDANCE STILL INDICATES A CHANCE OF SNOW
THURS/THU NIGHT WITH NEXT IN SERIES OF CLIPPERS. BULK OF MED RANGE
GUIDANCE TRACKS THE SFC LOW NORTH OF PA...LIKELY RESULTING IN
MINIMAL ACCUMS ACROSS OUR AREA. ECENS SHOWS A DEEPENING UPPER LVL
TROF OVR THE EASTERN CONUS BY NEXT WEEKEND...OFFERING NO RESPITE
FROM THE COLD WX.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
REDUCTIONS CONTINUE REGIONWIDE AS INVERTED TROUGH LINGERS OVER
CENTRAL PA /AND AS DEVELOPING NOR`EASTER BEGINS TO DEEPEN OFF MID
ATLANTIC COAST/. EXPECT WIDESPREAD LIGHT SNOW TO CONTINUE THIS
INTO TONIGHT WITH VSBYS VARYING FROM 1-4SM AND CIGS OF MVFR- IFR
SETTLING BACK TOWARD A MORE ROBUST IFR DECK. NE WINDS WILL BE
AROUND 10 MPH TODAY...AND PICK UP A BIT TO 10-15 MPH IN THE LOWER
SUSQ TONIGHT AS STORM DEEPENS TO THE EAST AND SYNOPTIC FLOW
INCREASES.
IMPROVING CONDITIONS ON TUES AS HIGH PRESSURE BUILDS IN. SHOULD
SEE VFR CONDITIONS IN CENTRAL AND EAST...WITH MVFR CIGS IN NW FLOW
UNDER SUBSIDENCE INVERSION IN THE WESTERN HIGHER TERRAIN. NORTH
WIND WILL BE BREEZY...PRODUCING SPEEDS OF 10-20 MPH.
OUTLOOK...
TUE...AREAS MVFR IN SHSN WEST...GENERALLY VFR EAST. BREEZY N WIND.
WED...VFR WITH NO SIG WEATHER EXPECTED.
THU...VFR TO START...WITH LATE DAY RESTRICTIONS SPREADING IN FROM
THE WEST.
THU NIGHT-FRI...WIDESPREAD IFR/MVFR IN SNOW.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR PAZ004>006-
010>012-017>019-024>026-033>036-045-058-059-064>066.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ027-
028-041-046-049>053-056-057-063.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...FITZGERALD/MARTIN
AVIATION...DEVOIR/MARTIN/RXR
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
328 AM CST MON JAN 26 2015
.DISCUSSION...
CURRENTLY...CLOUDY SKIES ACROSS THE MIDSOUTH WITH TEMPS DROPPING
INTO THE 30S UNDER NW WINDS AT 10 TO 20 MPH WITH HIGHER GUSTS.
TODAY...THE POTENT UPPER TROF THAT WILL SOON HELP CREATE THE
NORTHEAST U.S. BLIZZARD IS PUSHING TOWARD THE EASTERN SEABOARD
AND AWAY FROM THE MIDSOUTH. A QUICK MOVING SURFACE RIDGE OF HIGH
PRESSURE SANDWICHED BETWEEN THIS DEPARTING SYSTEM AND ANOTHER WEAK
SURFACE LOW DEVELOPING OVER THE MID MISSISSIPPI VALLEY WILL PUSH
THROUGH TODAY. WINDS WILL SHIFT FROM NORTH THIS AFTERNOON TO
SOUTHWEST BY THIS EVENING. AS A RESULT OF THIS WIND SHIFT EXPECT
LOW CLOUDS TO CLEAR OUT DURING THE DAY...LINGERING THE LONGEST
ACROSS NORTHEAST SECTIONS OF WEST TENNESSEE. TEMPS WILL BE COOL
ESPECIALLY ACROSS THE EAST... ALONG THE TN RIVER...WHERE LOWER 40S
IS ABOUT THE LIMIT...TEMPS WILL HIT 50 ACROSS PARTS OF EAST
ARKANSAS WHERE SUNSHINE WILL BE MORE PLENTIFUL.
TONIGHT...A WEAK SURFACE LOW WILL DROP INTO WESTERN MIDDLE
TENNESSEE AFTER MIDNIGHT AND PUSH A WEAK COLD FRONT THROUGH THE
AREA. THIS WILL SERVE TO SWITCH THE SURFACE WINDS BACK AROUND TO
THE NORTH. WINDS WILL PROBABLY BE A LITTLE GUSTY BY MORNING AND
WILL KEEP THE AIRMASS MIXED. AS A RESULT LOWS WILL ONLY BE ABLE
TO DROP INTO THE MID AND UPPER 30S.
TUESDAY AND TUESDAY NIGHT...BEHIND THE QUICK MOVING SURFACE LOW
AND COLD FRONT EXPECT GUSTY NORTH WINDS AND SOME ADDITIONAL LOW
CLOUDS TO MOVE BACK IN ESPECIALLY NEAR THE TN RIVER. THE MAV AND
MET ARE QUITE A BIT COOLER THAN THE PREVIOUS FORECAST AND HAVE HAD
TO CUT TEMPS ACROSS MUCH OF THE AREA. HIGHS WILL RANGE FROM THE
MID 40S NEAR PARIS...WHERE CLOUDS WILL LINGER MUCH OF THE DAY TO
THE MID 50S ACROSS SW PORTIONS OF THE FORECAST AREA. MOSTLY CLEAR
SKIES AND LIGHT WINDS WILL ALLOW TEMPS TO DROP INTO THE UPPER 20S
AND LOWER 30S TUESDAY NIGHT.
WEDNESDAY THROUGH FRIDAY...NICE DAY ON TAP FOR WEDNESDAY AS UPPER
FLOW TURNS MORE ZONAL AND SOUTHWEST SURFACE WINDS DEVELOP AHEAD
AN APPROACHING COLD FRONT. TEMPS WILL CLIMB INTO THE 50S JUST
ABOUT EVERYWHERE. THE MOISTURE STARVED FRONT WILL PUSH THROUGH
LATE WEDNESDAY NIGHT AND THURSDAY WITH ONLY SLIGHT CHANCE OF
SHOWERS ACROSS EASTERN SECTIONS. WEDNESDAY NIGHT WILL BE MILD
UNDER PERSISTENT SOUTHERLY FLOW AND HIGHS ON THURSDAY WILL REACH
WELL INTO THE 50S BEFORE THE COOLER AIR MOVES IN. COOL HIGH
PRESSURE SETTLES IN FOR FRIDAY WITH HIGHS BACK IN THE 40S.
SATURDAY AND SUNDAY...POTENTIAL OVERRUNNING SITUATION SETS UP
WITH DEVELOPING WSW FLOW ALOFT OVER A COOL AIRMASS AT THE SURFACE.
MODELS TIMING AND CONSISTENCY ARE NOT GREAT AT THIS POINT. GFS IS
FASTER...ECMWF IS SLOWER. WILL COMPROMISE WITH LOW POPS THROUGH
THE WEEKEND AND BELOW NORMAL TEMPS.
SJM
&&
.AVIATION...
06Z TAFS
MVFR WILL PREVAIL AREAWIDE DURING THE OVERNIGHT. THE BACKSIDE OF
THE STRATUS DECK HAD PASSED THROUGH MCI AT 05Z. THE 02Z HRRR MODEL
SHOWED IFR CONTINUING OVERNIGHT OVER CENTRAL MO...WHILE BREAKING
UP MVFR CIGS OVER NORTHEAST AR BY DAYBREAK.
VFR AND RELAXING/BACKING WINDS WILL PREVAIL AREAWIDE ON MONDAY.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1139 PM CST SUN JAN 25 2015
.UPDATE...
UPDATED FOR 06Z AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 839 PM CST SUN JAN 25 2015/
UPDATE...
UPDATED THIS EVENING TO FINE-TUNE POPS AND ALSO BETTER TIME THE
EXIT OF PRECIP TONIGHT. ELECTED TO ADD LIKELY POPS ACROSS PORTIONS
OF MIDDLE TENNESSEE CLOSER TO THE VORT MAX ROTATING SOUTHEAST. A
BAND OF WIDESPREAD SHOWERS WAS MOVING SOUTHEAST AND WILL AFFECT
THE REGION THROUGH MIDNIGHT. ELSEWHERE...MAINTAINED SLIGHT CHANCE
TO CHANCE POPS TO ACCOUNT FOR REMNANT SHOWERS MORE ASSOCIATED WITH
DAYTIME HEATING AND THE (VERY) COLD POCKET NEAR 500 MB. THESE WILL
CONTINUE TO WANE THROUGH THE EVENING. OTHERWISE...FORECAST LOOKS
GOOD WITH A WARM-UP SCHEDULED THROUGH MID-WEEK.
TVT
PREV DISCUSSION... /ISSUED 534 PM CST SUN JAN 25 2015/
UPDATE...
UPDATED FOR 00Z AVIATION DISCUSSION BELOW.
PREV DISCUSSION... /ISSUED 309 PM CST SUN JAN 25 2015/
DISCUSSION...WATER VAPOR SATELLITE/WSR-88D VAD WIND PROFILES THIS
AFTERNOON PLACE A CLOSED UPPER LEVEL LOW OVER SOUTHERN ILLINOIS
THIS AFTERNOON. A SHORTWAVE ROTATING AROUND THE UPPER LEVEL LOW IS
PRODUCING RAIN SHOWERS ACROSS THE MID SOUTH THIS AFTERNOON. AS OF
2 PM CST...TEMPERATURES ARE IN THE 50S AT MOST LOCATIONS.
SHORT TERM...(TONIGHT THROUGH WEDNESDAY)...AN UPPER LEVEL LOW
OVER SOUTHERN ILLINOIS WILL GRADUALLY MOVE TO THE APPALACHIANS BY
MONDAY AND THE MID ATLANTIC COAST BY MONDAY NIGHT. LATEST SHORT
TERM MODEL TRENDS SUGGEST CHANCES FOR RAIN SHOWERS WILL PERSIST
ACROSS THE MID SOUTH THIS EVENING AS ANOTHER SHORTWAVE TROUGH
ROTATING AROUND THE UPPER LEVEL LOW ROTATES THROUGH THE LOWER
MISSISSIPPI VALLEY. AT THIS TIME...IT APPEARS THAT PRECIPITATION
SHOULD BE OUT OF THE FORECAST AREA AROUND/AFTER 06Z...AND HAVE
LEFT THE REMAINDER OF TONIGHT/S FORECAST PRECIPITATION FREE.
SURFACE AND UPPER LEVEL RIDGING WILL BUILD BACK IN ACROSS THE MID
SOUTH FOR MONDAY THROUGH WEDNESDAY. TEMPERATURES THROUGH THE SHORT
TERM WILL AVERAGE NEAR NORMAL THROUGH MUCH OF THE PERIOD.
LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)...LONG TERM MODELS
INDICATE ANOTHER COLD FRONT WILL MOVE THROUGH THE LOWER
MISSISSIPPI VALLEY ON THURSDAY. QUESTIONS REMAIN WITH THE AMOUNT
OF MOISTURE WITH THIS SYSTEM AND HAVE KEPT CHANCES ON THE LOW END
FOR NOW.
CJC
&&
.AVIATION...
06Z TAFS
MVFR WILL PREVAIL AREAWIDE DURING THE OVERNIGHT. THE BACKSIDE OF
THE STRATUS DECK HAD PASSED THROUGH MCI AT 05Z. THE 02Z HRRR MODEL
SHOWED IFR CONTINUING OVERNIGHT OVER CENTRAL MO...WHILE BREAKING
UP MVFR CIGS OVER NORTHEAST AR BY DAYBREAK.
VFR AND RELAXING/BACKING WINDS WILL PREVAIL AREAWIDE ON MONDAY.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1126 PM CST SUN JAN 25 2015
.DISCUSSION...
SEE 06Z AVIATION DISCUSSION.
&&
.AVIATION...
VFR CONDS TO PREVAIL FOR THE NEXT 24 HOURS. LLWS WILL BE POSSIBLE
THROUGH EARLY MONDAY AS THE NAM12 AND RAP CONTINUE TO SHOW 40-45
KNOTS AT 925 MB. 43
&&
.PREV DISCUSSION... /ISSUED 910 PM CST SUN JAN 25 2015/
UPDATE...
CURRENT FORECAST REMAINS ON TRACK AS HIGH CLOUDS DRIFT ACROSS THE
AREA WITH ONLY MINOR TWEAKS MADE TO HOURLY TEMPERATURES AND DEW
POINTS BASED ON LATEST OBSERVATIONS. WEST TO NORTHWEST WINDS
BEHIND TODAY/S COLD FRONT WILL HELP DRIER AIR FILTER INTO THE
AREA...ALLOWING LOW TEMPERATURES TO FALL INTO THE UPPER 30S TO MID
40S.
HUFFMAN
PREV DISCUSSION... /ISSUED 300 PM CST SUN JAN 25 2015/
DISCUSSION...
VIS SATELLITE SHOWS SOME NICE CIRRUS STREAMING OVER SE TX THIS
AFTERNOON. A DRY COLD FRONT PUSHED THROUGH THE AREA SHIFTING
WINDS TO THE NW AND REALLY THATS ABOUT IT. GIVEN NW WINDS...TEMPS
HAVE REACHED CLOSE TO 70 AS COLD ADVECTION LAGS. MOSTLY CLEAR
SKIES AND DRY AIRMASS SHOULD ALLOW FOR MIN TEMPS BACK IN THE UPPER
30S/LOW 40S FOR MON MORNING. MAX TEMPS TOMORROW WILL BE SLIGHTLY
COOLER BUT A NICE WARM UP WILL BE ON TAP FOR THE NEXT FEW DAYS.
POTENT SHORT WAVE TROUGH OVER MISS/TN RIVER VALLEYS ON WATER
VAPOR IMAGERY WILL QUICKLY MOVE EAST INTO THE MID ATLANTIC. THE
SYSTEM SHOULD BOMB OUT WITH DEEPENING LOW PRESSURE AND BLIZZARD
CONDITIONS LATE MON THROUGH WED. HOW DOES THIS IMPACT HOUSTON?
LETS JUST SAY YOU SHOULD NOT EXPECT TO FLY EAST ANY TIME SOON
ESPECIALLY JFK/LGA/BOS. WHILE THERE SHOULD NOT BE ANY DELAYS AT
IAH/HOU THERE MAY BE SOME TRICKLE DOWN TRAVEL IMPACTS.
OVERALL UPPER LEVEL PATTERN REMAINS AMPLIFIED THROUGH THE END OF
THE WEEK WITH RIDGING OVER THE WESTERN THIRD OF THE U.S. AND NW
FLOW/LONG WAVE TROUGH OVER THE EASTERN 2 THIRDS OF THE U.S. BY THE
END OF THE WEEK...GFS/ECMWF DEVELOP ANOTHER UPPER LOW OVER S
CALIFORNIA AND BAJA PENINSULA. THIS SEEMS TO BE A FAVORED REGION
FOR CUT OFF LOWS THIS YEAR. THE PATTERN LOOKS VERY SIMILAR TO THE
RECENT RAIN EVENT AND THEN RUN OF GOOD WEATHER AFTER THAT. GRANTED
IT IS NEXT WEEKEND BUT WE WILL CONTINUE TO SHOW 30-50 PERCENT RAIN
CHANCES STARTING SAT INTO SUN. A COLD FRONT WILL PUSH INTO THE
AREA THUR INTO FRI SO THERE SHOULD BE ANOTHER SET UP FOR GOOD COLD
RAIN. THE HARDEST PART WILL BE TIMING ANY WEAK SHORT WAVE TROUGHS
THAT PUSH THROUGH IN THE MAIN JET FLOW. GFS/ECMWF HAVE SOME
DIFFERENCES IN THAT REGARD. GFS IS WET AT FIRST BUT REALLY HANGS
THE CUTT OFF OUT OVER THE BAJA. ECMWF IS DRIER AT FIRST...HAS ONE
CLUSTER OF RAIN NEXT SUN AND THEN FINALLY EJECTS THE UPPER LOW
OVER THE AREA FOR ANOTHER GOOD SOAKER IN THE 8-10DAY RANGE. WITH
THAT IN MIND...STANDARD DISCLAIMER APPLIES...DETAILS OF THE 8-10
DAY FORECAST WILL CHANGE QUITE A BIT WITH FUTURE MODEL RUNS. STILL
SOMETHING TO MONITOR.
39
MARINE...
W/SWLY WINDS JUST A BIT STRONGER THAN PREVIOUSLY EXPECTED FOR THIS
AFTN...ESPECIALLY FOR THE OFFSHORE WATERS. THIS TIGHTENED GRADIENT
WILL LIKELY RELAX A BIT THIS EVE AS THE WEAK SFC BOUNDARY MOVES IN
FROM THE N/NW. NO REAL CHANGE FROM CURRENT FCST OF SCEC CONDITIONS
TONIGHT/EARLY MON. HIGH PRESSURE BUILDING BACK INTO THE REGION BE-
HIND THE FRONT WILL HELP TO DECREASE WINDS/SEAS BY MON AFTN/EVE IF
ALL GOES WELL. THE GENERALLY LIGHT WLY FLOW MON SHOULD GIVE WAY TO
GENERALLY LIGHT ONSHORE WINDS FOR TUES/WEDS. THE NEXT FRONT ON TAP
FOR LATE THURS. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 42 66 48 73 50 / 0 0 0 0 0
HOUSTON (IAH) 43 65 47 74 47 / 0 0 0 0 0
GALVESTON (GLS) 47 60 51 66 54 / 0 0 0 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 9 AM CST MONDAY FOR
THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA
SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO
FREEPORT OUT 20 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION THROUGH MONDAY MORNING FOR
THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA
SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT 20 TO 60 NM.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
528 PM CST TUE JAN 27 2015
UPDATED AVIATION PORTION FOR 00Z TAF 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 00Z TAF ISSUANCE
ISSUED AT 526 PM CST TUE JAN 27 2015
LOOKS LIKE WE/VE MISSED OUT ON OUR OPPORTUNITY TO GET RID OF THE
LOW CLDS. THEY ARE NOW FIRMLY IN PLACE ACRS THE ENTIRE FCST
AREA...TRAPPED BY THE WK FLOW WITHIN THE LOW-LEVEL RIDGE. EXPECT
CIGS AND VSBYS TO GRADUALLY COME DOWN OVERNIGHT...WITH IMPROVEMENT
NOT OCCURRING UNTIL MID-DAY OR AFTN TOMORROW.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......SKOWRONSKI
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
459 PM CST MON JAN 26 2015
.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 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1142 AM CST MON JAN 26 2015
LIGHT FREEZING DRIZZLE WILL IMPACT KLSE AT TIMES THIS AFTERNOON AND
COULD POSSIBLY CONTINUE INTO EARLY THIS EVENING. TEMPERATURES MAY
WARM ENOUGH FOR THE PRECIPITATION TO FALL AS DRIZZLE AT THE
SURFACE LATE THIS AFTERNOON. WINDS WILL SWITCH TO THE WEST THEN
TO THE NORTHWEST THIS AFTERNOON AS A WARM FRONT EDGES IN. PLAN ON
MVFR CONDITIONS WITH IFR CONDITIONS POSSIBLE AT TIMES AT KLSE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ017-
029-032>034-041>044-053>055-061.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...AJ
SHORT TERM...DAS
LONG TERM....DAS
AVIATION...WETENKAMP
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.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 18Z TAF ISSUANCE
ISSUED AT 1124 AM CST MON JAN 26 2015
CLIPPER SYSTEM WILL BE MOVING SOUTH ACROSS THE REGION THROUGH
TONIGHT. LIGHT SNOW...DROPPING VSBYS TO MAINLY IFR...LOCALLY
LIFR...WILL SPREAD EAST INTO EASTERN WISCONSIN THIS AFTERNOON.
PATCHY FZDZ MAY IMPACT CENTRAL AND NORTH-CENTRAL WISCONSIN AT TIMES
THROUGH TONIGHT...BUT HIGHER IMPACTS SHOULD RESIDE WEST OF THIS
AREA. TOTAL ACCUMULATIONS WILL MOSTLY FALL INTO THE 1-2 INCH
RANGE...LOCALLY HIGHER OVER CENTRAL AND NORTH-CENTRAL WISCONSIN.
THE SNOW AND SPOTTY FREEZING DRIZZLE WILL GRADUALLY BE DIMINISHING
LATE THIS EVENING INTO THE OVERNIGHT. PLENTY OF LOW CIGS
UPSTREAM...SO THINK SKIES WILL REMAIN IFR/MVFR OVERCAST THROUGH MUCH
OF TUESDAY MORNING.
MPC.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR WIZ035.
&&
$$
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1135 PM CST SUN JAN 25 2015
.UPDATE...
ISSUED AT 831 PM CST SUN JAN 25 2015
AFTER MUCH DELIBERATION...HAVE DECIDED TO ISSUE THE WINTER
WEATHER ADVISORY FOR SOME OF THE FORECAST AREA. THE COUNTIES ALONG
THE MISSISSIPPI RIVER HAVE THE HIGHEST CONFIDENCE OF SEEING A
COUPLE HUNDREDTHS OF FREEZING DRIZZLE AS THE SNOW ENDS...WHILE IN
TAYLOR/CLARK COUNTIES THE POTENTIAL EXISTS FOR A LITTLE MORE SNOW
TO FALL THAN WHATS EVEN CURRENTLY FORECAST. THATS BECAUSE THE
RAP CONTINUES TO SHOW 7 C/KM LAPSE RATES MARCHING THROUGH WESTERN
WISCONSIN MONDAY MORNING...WHICH SHOULD ADD SOME CONVECTIVE
ENHANCEMENT TO THE SNOWFALL. THE EXPERIMENTAL HRRR AT BOULDER ALSO
SHOWS THIS CONVECTIVE ENHANCEMENT...EVEN INTO SOUTHEAST MN AND
INTO THE LSE AREA...RIGHT AT MORNING COMMUTE TIME.
ALTHOUGH SNOWFALL AMOUNTS WILL NOT REACH ADVISORY CRITERIA
ALONE...THE COMBINATION OF THE SNOW AND FREEZING DRIZZLE SHOULD
MAKE FOR A MESS ON ROADWAYS...ESPECIALLY THOSE LEFT UNTREATED.
ADDITIONALLY...HAVING THIS PRECIPITATION COME THROUGH AT MORNING
COMMUTE TIME IS ALSO A PROBLEM. THESE ARE THE MAIN REASONS WHY THE
ADVISORY HAS BEEN ISSUED.
UPDATE ISSUED AT 541 PM CST SUN JAN 25 2015
FOLLOWING THE SITUATION CLOSELY FOR MONDAY AS A WINTER WEATHER
ADVISORY MAY BE REQUIRED.
GOOD MODEL CONSENSUS EXISTS BETWEEN THE 25.15Z SREF...25.18Z
NAM/GFS AND 25.21Z RAP FOR SNOW TO MOVE INTO THE REGION VERY LATE
TONIGHT INTO MONDAY MORNING. GOOD DYNAMICAL SUPPORT IN THE MORNING
WITH A SHORTWAVE COMING THROUGH AS WELL AS HAVING THE LEFT EXIT
REGION OF AN UPPER LEVEL JET SITUATED OVERHEAD. ADDITIONALLY...THE
APPROACH OF A WARM FRONT WILL PROVIDE LOW LEVEL LIFT. THE CONCERN
BECOMES WHEN THE SHORTWAVE AND LEFT EXIT REGION LEAVE THE AREA BY
LATE MORNING...CAUSING MID-LEVEL DRYING AND THUS LOSS OF ICE IN
THE CLOUDS. MEANWHILE...WE STILL HAVE THAT WARM FRONT COMING INTO
THE REGION FROM NEAR I-35 TO PROVIDE THAT LOW LEVEL LIFT. THUS IT
APPEARS LIKELY WE SHOULD SEE SOME FREEZING DRIZZLE BY MID-LATE
MORNING...ESPECIALLY ALONG THE MISSISSIPPI RIVER COUNTIES.
ONE BENEFIT IS THAT SNOW IS STARTING OUT FIRST...WHICH SHOULD
MINIMIZE THE IMPACT OF THE FREEZING DRIZZLE ON TRAVEL.
HOWEVER...IF ROADS DO NOT GET TREATED...THEY COULD EASILY BE
SLIPPERY DUE TO THE COMBINATION OF SNOW AND FREEZING DRIZZLE.
ADDITIONALLY...THERE COULD BE ISSUES WITH THE SNOW COMING IN AT
COMMUTE TIME. SO BOTH SOME PROS AND CONS FOR A WINTER WEATHER
ADVISORY.
ANOTHER CONCERN IS THAT THE WARM FRONT MAY NOT MAKE IT FARTHER
EAST THAN A ROCHESTER TO OELWEIN LINE...KEEPING THE MISSISSIPPI
RIVER COUNTIES AT OR BELOW FREEZING THROUGH THE AFTERNOON...WHICH
WOULD BE COLDER THAN OUR CURRENT FORECAST. ALTHOUGH THE LOW LEVEL
LIFT IS PROGGED TO WEAKEN IN THE AFTERNOON...THERE IS PLENTY TO
KEEP SOME DRIZZLE GOING...WHICH COULD THEN FREEZE IF OUR
TEMPERATURES STAY COLD. ON THE OTHER HAND...DAYLIGHT THROUGH THE
CLOUDS MAY HEAT UP ROADS ENOUGH TO PREVENT ICING. NEEDLESS TO
SAY...PLENTY OF UNCERTAINTIES.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 257 PM CST SUN JAN 25 2015
CHALLENGES CONCERN PRECIPITATION CHANCES/AMOUNTS/TYPE LATE TONIGHT
THROUGH MONDAY WITH THE NEXT CANADIAN TROUGH MOVING THROUGH
NORTHWEST FLOW ALOFT. 25.12Z MODEL SUITE IN GOOD OVERALL AGREEMENT
WITH PRECIPITATION PLACEMENT...BUT DIFFER SLIGHTLY ON AMOUNTS...
ESPECIALLY EAST OF THE MS RIVER VALLEY. WILL USE A BLENDED
SOLUTION OF THE 25.12Z GFS/NAM/ECMWF/GEM WITH ADDITIONAL SUPPORT
FROM THE LATEST SUITE OF HIGH-RESOLUTION MODEL GUIDANCE.
THIS EVENING WILL BE PARTLY TO MOSTLY CLOUDY AND COOL WITH
TEMPERATURES DROPPING INTO THE LOWER TEENS TO LOWER 20S.
PRECIPITATION WILL HOLD OFF UNTIL AFTER MIDNIGHT WHEN AN 850 HPA
TROUGH OVER CENTRAL MANITOBA/EASTERN DAKOTAS MOVES ACROSS MN AND
INTO THE UPPER MS RIVER VALLEY. MODEST MID-LEVEL WARM AIR
ADVECTION/ISENTROPIC LIFT AND QG CONVERGENCE ALONG FRONTAL
BOUNDARY WILL SLIDE FROM WEST TO EAST ACROSS THE FORECAST AREA
MONDAY MORNING. INITIAL THERMAL/MOISTURE PROFILES ARE COLD ENOUGH
AND SATURATED TO AROUND 500 HPA FOR ALL SNOW. HOWEVER...AS DAY
PROGRESSES...ICE LOSS OCCURS AS 700 TO 500 HPA LAYER DRYS OUT.
WITH SUB-FREEZING BOUNDARY LAYER TEMPERATURES...EXPECT SNOW TO
TRANSITION TO FREEZING DRIZZLE FROM WEST TO EAST THROUGH THE DAY.
SNOW ACCUMULATION WILL BE GREATEST ALONG AND EAST OF A LINE FROM
EAU CLAIRE TO BLACK RIVER FALLS TO PLATTEVILLE WITH 1 TO 2 INCHES.
FARTHER WEST TO THE MS RIVER...A QUICKER CHANGE OVER TO DRIZZLE
WILL KEEP SNOW AMOUNTS GENERALLY IN THE HALF INCH TO AN INCH
RANGE. SNOW WEST OF THE RIVER WILL BE A TRACE TO HALF INCH.
A THIN GLAZE OF ICE FROM FREEZING DRIZZLE IS POSSIBLE MONDAY
MORNING...ESPECIALLY ALONG AND EAST OF THE MS RIVER VALLEY...BUT
BECAUSE THERE IS LIKELY TO BE A SHARP CUT-OFF BETWEEN THE STRONGEST
FORCING/BACK EDGE OF PRECIPITATION AND WHEN ICE LOSS OCCURS...
CONFIDENCE NOT HIGH ENOUGH AT THIS TIME TO HOIST AN ADVISORY.
IMPACTS TO THE MORNING COMMUTE A POSSIBILITY AND CERTAINLY
SOMETHING TO KEEP A CLOSE EYE ON THIS EVENING AND OVERNIGHT. IF
ICE ACCUMULATION DOES HAPPEN...IT SHOULD QUICKLY MELT AS
TEMPERATURES RISE TO ABOVE FREEZING FOR ALL AREAS EXCEPT THE FAR
EAST BEHIND THE WARM FRONT.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 257 PM CST SUN JAN 25 2015
LINGERING LIGHT SNOW/FREEZING DRIZZLE WILL PUSH EAST MONDAY NIGHT
WITH DRY CONDITIONS THROUGH TUESDAY AS SURFACE HIGH PRESSURE
BUILDS ACROSS THE REGION. SHOULD SEE SOME SUN BY LATE TUESDAY WITH
TEMPERATURES RISING INTO THE LOWER TO MID 30S.
WEDNESDAY WILL BE DRY AND POTENTIALLY QUITE WARM AS LOW PRESSURE
DRIFTS ACROSS THE REGION AND KEEPS MOST OF THE FORECAST AREA
WITHIN THE WARM SECTOR. PRECIPITATION WILL REMAIN TO THE NORTH
WITH 850 HPA TEMPERATURES ACROSS THE UPPER MS RIVER VALLEY FROM
+2 TO +5 C. CLOUD COVER COULD LIMIT TEMPERATURE RISE...BUT LOWER
40S A REAL POSSIBILITY...ESPECIALLY ACROSS NORTHEAST IA INTO
SOUTHWEST WI. PRECIPITATION CHANCES INCREASE WEDNESDAY NIGHT INTO
THURSDAY AS MID-LEVEL WAVE WRAPS-UP ACROSS WI.
LATE THURSDAY THROUGH SUNDAY...NORTHWEST FLOW ALOFT PERSISTS
ALLOWING A SERIES OF WEAK WAVES TO TRANSLATE ACROSS THE UPPER
MIDWEST. THE STRONGEST OF THESE IMPACTS THE REGION FRIDAY NIGHT
INTO SATURDAY WITH A 20-30 PERCENT CHANCE OF LIGHT SNOW.
TEMPERATURES FOR THE LATTER HALF OF THE WEEK INTO NEXT WEEKEND
WILL DROP SLIGHTLY EACH DAY AS AN ARCTIC TROUGH DROPS SOUTH ACROSS
EASTERN CANADA AND INTO THE EASTERN CONUS. HIGHS IN THE UPPER 20S
TO LOWER 30S ON THURSDAY WILL DROP INTO THE MID TEENS TO LOWER 20S
BY SUNDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1135 PM CST SUN JAN 25 2015
MVFR STRATUS REMAINS OVER RST AND WAS EXPANDING QUICKLY TOWARDS
LSE LATE THIS EVENING DUE TO SOUTHWEST WINDS PICKING UP. LSE
SHOULD GO MVFR BY 07Z. ATTENTION THEN TURNS TO A LOW PRESSURE
SYSTEM DROPPING SOUTHEAST THROUGH MN. THIS SYSTEM WILL BRING SNOW
INTO THE TAF SITES AROUND 11Z...ALONG WITH A DROP OF VISIBILITIES
AND CEILINGS TO IFR. RST COULD EVEN GO LIFR IN CEILINGS. TOWARDS
13Z AT RST AND 16Z AT LSE...THE ICE IN THE CLOUDS IS EXPECTED TO
BE LOST...CAUSING THE SNOW TO CHANGE TO FREEZING DRIZZLE.
SWITCHING THE PRECIPITATION TYPE WILL HELP TO IMPROVE VISIBILITY
TO MVFR. HOWEVER...LITTLE CHANGE IS EXPECTED TO CEILING.
PRECIPITATION SHOULD END BY NOON AT RST AS A WARM FRONT MOVES
IN...BUT WINDS WILL INCREASE FROM THE WEST AND EVENTUALLY
NORTHWEST LATE IN THE DAY WITH A COLD FRONTAL PASSAGE. LSE IS
TRICKY WIND WISE WITH BOTH FRONTS FORECAST TO LAY UP RIGHT NEAR
THE TAF SITE FOR THE AFTERNOON AND EVENING. NEVERTHELESS...BOTH
SITES EXPECTED TO SEE CEILINGS INCREASE TO MVFR LATE IN THE DAY
INTO THE EVENING AS MIXING INCREASES.
LOOKING AT TOTAL SNOWFALL AMOUNTS LESS THAN 1 INCH...WHILE A
LIGHT GLAZING OF ICE COULD OCCUR...ESPECIALLY AT LSE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM 5 AM TO NOON CST MONDAY FOR WIZ017-
029-032>034-041-042-053.
MN...WINTER WEATHER ADVISORY FROM 5 AM TO NOON CST MONDAY FOR MNZ079-
088-096.
IA...NONE.
&&
$$
UPDATE...AJ
SHORT TERM...ROGERS
LONG TERM...ROGERS
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
346 AM CST WED JAN 28 2015
.SHORT TERM...
345 AM CST
TODAY THROUGH FRIDAY NIGHT...
MAIN FORECAST CONCERNS IN THE SHORT TERM ARE CLOUD AND TEMP TRENDS
TODAY AND TONIGHT...AND TIMING...COVERAGE AND TYPE OF PRECIPITATION
TONIGHT AND THURSDAY AS LOW PRESSURE ORGANIZING OVER THE PLAINS
MOVES EAST.
RELATIVELY QUIET WEATHER THIS MORNING AS SURFACE HIGH PRESSURE
DRIFTS SLOWLY EAST OF THE AREA. SUBSIDENCE ASSOCIATED WITH HEIGHT
RISES ALOFT HAS LED TO A STRONG INVERSION AT AROUND 900 HPA HOWEVER
PER DVN 00Z SOUNDING...WHICH HAS TRAPPED LOW CLOUDS ACROSS THE
WESTERN PORTIONS OF THE FORECAST AREA OVERNIGHT. CLOUDS WERE SLOWLY
ERODING FROM THE SOUTHEAST THANKS TO 950-900 HPA WINDS GRADUALLY
VEERING TO THE SOUTHEAST AND SOUTH...AND LOWERING SUBSIDENCE
INVERSION. RAP GUIDANCE INDICATES SOUTH WINDS WILL INCREASE THIS
MORNING AND SHOULD CONTINUE TO LIFT THESE LOWER CLOUDS NORTH TOWARD
THE WI BORDER...THOUGH OVERALL NORTH CENTRAL ILLINOIS IS LIKELY TO
BE CLOUDIER THAN AREAS SOUTH AND EAST TODAY EVEN AS MID AND HIGH
CLOUDS BEGIN TO INCREASE AS WARM ADVECTION DEVELOPS ALOFT.
SURFACE LOW PRESSURE IS ALREADY TAKING SHAPE ACROSS THE PLAINS TO
OUR WEST THIS MORNING...IN RESPONSE TO A SHORT WAVE TROUGH EMERGING
FROM THE CENTRAL/NORTHERN ROCKIES. SURFACE PRESSURE FALLS AHEAD OF
THIS DEVELOPING LOW WILL LEAD TO INCREASING SOUTH-SOUTHEAST WINDS
NEAR 25 MPH THIS AFTERNOON. DESPITE SOUTHERLY FLOW...LOW LEVEL
PARCEL TRAJECTORIES WILL BE LARGELY FROM INDIANA/OHIO WHERE STRONG
COOLING HAS OCCURRED NEAR THE SURFACE HIGH THIS MORNING. COMBINED
WITH SOME MID/HIGH CLOUD COVER THIS MAY MAKE FOR HIGH TEMPERATURES
COMING LATER IN THE DAY WHEN LOW LEVEL WINDS VEER MORE SOUTHERLY AND
TAP MILDER AIR CURRENTLY ACROSS THE MISSOURI VALLEY. STRONG SOUTH
FLOW WILL CONTINUE TONIGHT AHEAD OF THE APPROACHING SURFACE
LOW...ALLOWING TEMPS TO STAY ABOVE FREEZING IN MOST AREAS.
GUIDANCE IN GOOD AGREEMENT IN DEVELOPING SOME LIGHT SPOTTY
PRECIPITATION ACROSS THE AREA LATE THIS EVENING...EXPANDING
OVERNIGHT ESPECIALLY ACROSS NORTHERN/NORTHEASTERN PARTS OF THE
FORECAST AREA. FORECAST SOUNDINGS INDICATE WARM LAYER TEMPS ALOFT IN
THE +5C RANGE OR BETTER...WITH SATURATION INITIALLY OCCURRING BELOW
700 HPA AND SUPPORTING LIGHT RAIN. WITH BREEZY SOUTH SURFACE WINDS
KEEPING TEMPS ABOVE MAINLY ABOVE FREEZING...PRECIPITATION TYPE IS
EXPECTED TO REMAIN LIQUID IN MOST LOCATIONS. LOW PROBABILITY DOES
EXIST FOR LIGHT FREEZING RAIN ESPECIALLY ACROSS FAR NORTH/NORTHEAST
IL...BUT AT THIS TIME FEEL IT IS FAIRLY UNLIKELY. THE SURFACE
LOW...AND A PAIR OF UN-PHASED SHORT WAVES....MOVE ACROSS THE CWA
DURING THE MORNING AND RESULT IN WINDS SHIFTING TO THE NORTHWEST.
THIS BRINGS COLDER AIR INTO THE REGION WITH COLLAPSING THICKNESS
FIELDS SUPPORTING LINGERING PRECIPITATION CHANGING OVER FROM LIGHT
RAIN TO A BRIEF RAIN/SLEET/SNOW MIX BEFORE ENDING FROM WEST-EAST.
MOST PRECIPITATION SHOULD END BY NOON WEST OF ABOUT THE IL/IN STATE
LINE...AND SHORTLY AFTER ACROSS NORTHWEST INDIANA. HOWEVER...GUSTY
NORTH-NORTHWEST WINDS AND COLDER AIR SPREADING ACROSS LAKE MICHIGAN
WILL LIKELY SUPPORT LAKE EFFECT SNOW SHOWERS ACROSS PARTS OF EASTERN
LAKE AND PORTER COUNTIES ESPECIALLY THURSDAY EVENING INTO EARLY
FRIDAY MORNING. THE REMAINDER OF THE AREA WILL JUST BE BLUSTERY AND
COLDER...WITH NORTH-NORTHWEST WINDS GUSTING ABOVE 30 MPH AT TIMES
THURSDAY BEFORE SLOWLY DIMINISHING THURSDAY NIGHT. AFTER MORNING
HIGHS IN THE MID-UPPER 30S OR EVEN NEAR 40 IN SOME SPOTS...THURSDAY
NIGHT LOOKS TO BE COLD WITH LOWS IN THE TEENS TO LOW 20S AND SINGLE
DIGIT WIND CHILLS.
SURFACE HIGH PRESSURE SPREADS INTO THE AREA AGAIN ON FRIDAY...WITH
TEMPERATURES STRUGGLING INTO THE MID-UPPER 20S BUT WITH MUCH LIGHTER
WINDS. LAKE SNOW SHOWERS WILL DIMINISH ACROSS NORTHWEST INDIANA AS
INVERSION HEIGHTS LOWER AND LOW LEVEL WINDS DIMINISH...WITH SUNSHINE
ELSEWHERE.
RATZER
&&
.LONG TERM...
345 AM CST
SATURDAY THROUGH TUESDAY...
THE MAIN FOCUS IN THE EXTENDED PERIOD IS ON A STORM SYSTEM WHICH
LOOKS TO LIFT THROUGH THE OHIO VALLEY LATE SATURDAY NIGHT THROUGH
SUNDAY. ECMWF/GFS ARE IN RELATIVELY GOOD AGREEMENT IN TAKING SURFACE
LOW TRACK ALONG THE OHIO RIVER...THOUGH GFS IS A LITTLE SLOWER AND
GEFS ENSEMBLE MEMBERS STILL SHOW QUITE A BIT OF SPREAD IN THEIR
SOLUTIONS AT THE SURFACE. GEM ALSO SLOWER AND A BIT FARTHER SOUTH
THAN THE OTHER GLOBAL MODELS. DEPENDING UPON HOW THIS SYSTEM
EVENTUALLY TRACKS...IT COULD BE A SNOW PRODUCER FOR ALL OR PART OF
THE CWA...AS IT TAPS GULF MOISTURE DEFORMATION BAND WOULD LIKELY
CROSS CENTRAL IL/IN. GLOBAL MODELS ALSO INDICATE A STRONG SURGE OF
ARCTIC AIR IN THE WAKE OF THIS SYSTEM...WITH SIGNIFICANTLY COLDER
WEATHER I.E. LOWS +/- SINGLE DIGITS AND HIGHS PERHAPS ONLY IN THE
TEENS BY MONDAY/TUESDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* LOW CHANCE FOR 1500-2500 FT CIGS BEFORE 14Z.
* GUSTY SOUTH-SOUTHEAST SURFACE WINDS DEVELOPING BY 18Z.
* CHANCE FOR SCATTERED LIGHT RAIN SHOWERS BEGINNING LATE THIS
EVENING.
* SOUTH-SOUTHWEST WINDS OF AT LEAST 50 KT AROUND 2000 FT THIS
EVENING INTO OVERNIGHT THAT MAY CREATE LOW-LEVEL WIND SHEAR.
//DISCUSSION...UPDATED 06Z...
AS HIGH PRESSURE MOVES EAST OVERNIGHT...SOUTHERLY WINDS WILL
START TO BRING CLOUDS ACROSS NORTHWEST AND WEST CENTRAL ILLINOIS
BACK NORTH TO NORTHEASTWARD. WHILE THE CLOUDS ARE THIN...THEY ARE
UNDER A STRONG INVERSION OF 8C/1000 FT...SO NOT ENVISIONING MUCH
MORE EROSION OVERNIGHT. RFD SHOULD GO BACK TO BROKEN OR EVEN
OVERCAST AS THESE CLOUDS EXPAND BACK NORTHWARD AND IT IS POSSIBLE
ORD AND DPA DO AS WELL.
WITH THE APPROACH OF LOW PRESSURE...SOUTH-SOUTHEAST WINDS WILL
INCREASE WEDNESDAY WITH GUSTS LIKELY IN THE AFTERNOON AND
PERSISTING INTO THE EVENING AS STRONG PRESSURE FALLS SPREAD OVER.
GIVEN THE CURRENT AND FORECAST PLACEMENT OF THE LOW PRESSURE...THE
WIND DIRECTION SHOULD BE EAST OF SOUTH MUCH OF WEDNESDAY AND EARLY
WEDNESDAY EVENING...BEFORE GRADUALLY VEERING DURING LATER
WEDNESDAY NIGHT. A COLD FRONT WILL PASS IN THE PRE-DAWN HOURS.
AHEAD...ALONG...AND BEHIND THIS FRONT WILL BE POTENTIAL FOR
SCATTERED RAIN SHOWERS...WITH THAT CHANGING TO A RAIN AND SNOW
SHOWER CHANCE DURING THE DAY THURSDAY.
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* HIGH THAT IF MVFR CIGS DO RETURN PRIOR TO 14Z THEY WOULD BE
TEMPORARY.
* HIGH IN WIND SPEED AND IN WIND DIRECTION BEING SLIGHTLY EAST OF
SOUTH THROUGH THE DAY. MEDIUM IN WIND DIRECTION TONIGHT.
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...CHANCE OF RAIN/SNOW. MVFR LIKELY/IFR POSSIBLE.
FRIDAY...VFR. WX NIL.
SATURDAY...CHANCE OF SNOW IN THE AFTERNOON AND OVERNIGHT. VFR
EARLY THEN MVFR LIKELY/IFR POSSIBLE.
SUNDAY...CHANCE OF SNOW. IFR POSSIBLE.
MONDAY...VFR. WX NIL.
MTF/KREIN
&&
.MARINE...
158 AM CST
AN ACTIVE PERIOD WILL UNFOLD OVER LAKE MICHIGAN THROUGH THIS
FORECAST THANKS TO THE PROGRESSIVE NATURE IN THE WEATHER PATTERN.
HIGH PRESSURE EARLY THIS MORNING WILL EXIT THE PICTURE AND A QUICKLY
APPROACHING LOW PRESSURE FROM THE WEST WILL BRING INCREASING
SOUTHERLY WINDS LATER TODAY INTO THIS EVENING. DURING THE EVENING
THERE IS A PERIOD WHERE OCCASIONAL GALES SHOULD OCCUR ACROSS THE
SOUTHERN HALF AS SOME INSTABILITY WILL BE PRESENT WITH GALE FORCE
WINDS ONLY 1000-1500 FT OFF THE WATER SURFACE. THE LOW SHOULD BE
ELONGATED RIGHT DOWN THE AXIS OF THE LAKE AROUND 6 AM THURSDAY
BEFORE IT QUICKLY MOVES EAST. THIS WILL RESULT IN STOUT NORTHWEST
WINDS AND COLD ADVECTION ACROSS THE LAKE WITH WHAT LOOKS LIKE
DEFINITE GALES FOR AT LEAST THE OPEN WATER...INCLUDING 40 KTS
WITH 45 KTS EVEN POSSIBLE ESPECIALLY IN THE NORTH. THIS LIKELY
WILL BRING SOME FREEZING SPRAY THURSDAY NIGHT TO THE OPEN
WATER. AT THIS TIME FORECAST INGREDIENTS ARE A LITTLE SHY FOR
HEAVY FREEZING SPRAY SO NO WATCH FOR THAT ISSUED BUT WILL NEED TO
BE MONITORED.
HAVE OPTED TO GO WITH A GALE WATCH FOR BEHIND THE LOW PRESSURE AS
THAT TIME PERIOD WILL BE THE HIGHEST WINDS WITH THE SYSTEM. WILL
JUST MENTION OCCASIONAL GALES ON THE FRONT SIDE DURING THIS
EVENING ACROSS MAINLY THE SOUTH HALF. SMALL CRAFT ADVISORY
CONDITIONS WILL OBVIOUSLY EXIST A GOOD AMOUNT OF THIS TIME ON THE
ILLINOIS AND INDIANA NEAR SHORES. WITH A SHORT 4-6 HOUR RESPITE
CENTERED ON DAYBREAK THURSDAY AS THE LOW PASSES...HAVE OPTED TO NOT
EXTEND THE CURRENT SMALL CRAFT ADVISORY...BUT ONE WILL DEFINITELY
BE NEEDED FOR THURSDAY AFTERNOON AND NIGHT...AND FOR THE INDIANA
SHORE INTO FRIDAY. THE GALE WATCH DOES INCLUDE PARTS OF THE
INDIANA NEARSHORE THAT WILL FEEL THE GREATER FETCH OF ONSHORE
WINDS AND THUS COULD REALIZE GALES THURSDAY AFTERNOON AND EVENING.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...NOON WEDNESDAY TO 4 AM THURSDAY.
GALE WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ744-LMZ745-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...NOON
THURSDAY TO 3 AM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1149 PM CST TUE JAN 27 2015
.UPDATE...
905 PM CST
LOW CLOUD COVER CONTINUES TO SLOWLY MOVE WESTWARD AND HAS CLEARED
ALL BUT THE WESTERN FRINGES OF THE FORECAST AREA THIS EVENING.
SATELLITE SHOWS SOME HIGHER CLOUD STREAKS APPROACHING FROM THE
NORTHWEST AS UPPER RIDGING SHIFTS EASTWARD BUT COVERAGE LOOKS
LOOKS TO BE SPORADIC THROUGH THE NIGHT AND MAY BE AT A MINIMUM
DURING THE EARLY OVERNIGHT. TEMPERATURES HAVE BEGUN TO DROP OFF
WHERE THANKS TO THE MAINLY CLEAR SKIES WITH SEVERAL SITES IN
NORTH-CENTRAL ILLINOIS NOW IN THE TEENS. GIVEN THAT HIGHER CLOUD
COVER LOOKS INTERMITTENT AND WINDS WILL DROP OFF WITH HIGH
PRESSURE MOVING OVERHEAD HAVE GONE AHEAD AND LOWERED MINS
OVERNIGHT FOR MOST AREAS...THOUGH WESTERN FRINGES MAY SEE LOWER
LEVEL CLOUD COVER LINGER THROUGH THE NIGHT. WILL GO WITH LOWER
TEENS FOR MUCH OF THE WESTERN/CENTRAL CWA AND SOME OF THE
TRADITIONALLY COLDER SPOTS FROM LEE/OGLE COUNTIES TO DEKALB AND
KANE COUNTIES COULD SEE VALUES A LITTLE BIT LOWER IF HIGH CLOUD
COVER REMAINS VERY MINIMAL.
WITH THE LOWER TEMPS AND SPORADIC HIGHER CLOUD COVER...FREEZING
FOG WILL BE A CONCERN. THE COLDEST AREAS WILL LIKELY SEE A QUICK
DROP OFF IN THE NEXT FEW HOURS WHICH MAY LEAD TO MORE FROST
DEPOSITION RATHER THAN FOG FORMATION. WITH LIMITED CONFIDENCE IN
THIS HAPPENING AND REASONABLE SUPPORT FOR SOME FOG
DEVELOPMENT...WILL GO AHEAD AND ADD PATCHY FOG TO MUCH OF THE
CENTRAL AND WESTERN CWA OR FROM THE FAR WESTERN CHICAGO METRO WEST
AND SOUTHWEST FOR NOW. THIS MAY CAUSE SOME SLICK SPOTS ON ROADS
OVERNIGHT.
MDB
&&
.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 06Z...
* CHANCE FOR 1500-2500 FT CIGS BEFORE 14Z.
* GUSTY SOUTH-SOUTHEAST SURFACE WINDS DEVELOPING BY 18Z.
* CHANCE FOR SCATTERED LIGHT RAIN SHOWERS BEGINNING LATE WEDNESDAY
EVENING.
* SOUTH-SOUTHWEST WINDS OF AT LEAST 50 KT AROUND 2000 FT WEDNESDAY
EVENING THAT MAY CREATE LOW-LEVEL WIND SHEAR.
//DISCUSSION...UPDATED 06Z...
AS HIGH PRESSURE MOVES EAST OVERNIGHT...SOUTHERLY WINDS WILL
START TO BRING CLOUDS ACROSS NORTHWEST AND WEST CENTRAL ILLINOIS
BACK NORTH TO NORTHEASTWARD. WHILE THE CLOUDS ARE THIN...THEY ARE
UNDER A STRONG INVERSION OF 8C/1000 FT...SO NOT ENVISIONING MUCH
MORE EROSION OVERNIGHT. RFD SHOULD GO BACK TO BROKEN OR EVEN
OVERCAST AS THESE CLOUDS EXPAND BACK NORTHWARD AND IT IS POSSIBLE
ORD AND DPA DO AS WELL.
WITH THE APPROACH OF LOW PRESSURE...SOUTH-SOUTHEAST WINDS WILL
INCREASE WEDNESDAY WITH GUSTS LIKELY IN THE AFTERNOON AND
PERSISTING INTO THE EVENING AS STRONG PRESSURE FALLS SPREAD OVER.
GIVEN THE CURRENT AND FORECAST PLACEMENT OF THE LOW PRESSURE...THE
WIND DIRECTION SHOULD BE EAST OF SOUTH MUCH OF WEDNESDAY AND EARLY
WEDNESDAY EVENING...BEFORE GRADUALLY VEERING DURING LATER
WEDNESDAY NIGHT. A COLD FRONT WILL PASS IN THE PRE-DAWN HOURS.
AHEAD...ALONG...AND BEHIND THIS FRONT WILL BE POTENTIAL FOR
SCATTERED RAIN SHOWERS...WITH THAT CHANGING TO A RAIN AND SNOW
SHOWER CHANCE DURING THE DAY THURSDAY.
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM THAT IF MVFR CIGS DO RETURN PRIOR TO 14Z THEY WOULD BE
TEMPORARY.
* HIGH IN WIND SPEED AND IN WIND DIRECTION BEING SLIGHTLY EAST OF
SOUTH THROUGH THE DAY WEDNESDAY. MEDIUM IN WIND DIRECTION
WEDNESDAY EVENING.
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...CHANCE OF RAIN/SNOW. MVFR LIKELY/IFR POSSIBLE.
FRIDAY...VFR. WX NIL.
SATURDAY...CHANCE OF SNOW IN THE AFTERNOON AND OVERNIGHT. VFR
EARLY THEN MVFR LIKELY/IFR POSSIBLE.
SUNDAY...CHANCE OF SNOW. IFR POSSIBLE.
MONDAY...VFR. WX NIL.
MTF/KREIN
&&
.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.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1139 PM CST Tue Jan 27 2015
.UPDATE...
ISSUED AT 639 PM CST TUE JAN 27 2015
Made some quick updates to the forecast this evening, mainly to
better reflect current and expected sky trends. 00z/6pm IR
satellite imagery shows cloud cover steadily eroding from the
E/NE, with mostly clear skies currently noted along/northeast of a
Champaign to Paris line. Clouds are beginning to break up south of
there along/south of the I-70 corridor as well. Based on satellite
loops and the latest HRRR forecast, it appears skies will become
partly to mostly clear across much of the KILX CWA tonight, except
perhaps the far NW around Galesburg. Will continue to monitor
trends to see if additional updates are needed, but for now will
hold on to overcast conditions through the entire night northwest
of the Peoria area with clearing skies elsewhere. Low temperatures
will be coldest where clearing has already occurred across the NE
CWA around Danville, where readings will dip into the teens. Lower
to middle 20s seem reasonable across the rest of central Illinois.
&&
.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 06Z TAFS through 06Z Wednesday night)
ISSUED AT 1139 PM CST TUE JAN 27 2015
Skies have cleared across much of central and southeast Illinois
late this evening, with MVFR ceilings persisting along/northwest
of a KBMI to KIJX line. IR satellite imagery continues to show
this area of clouds retreating to the northwest as light E/SE
return flow develops on the back side of departing high pressure.
Based on satellite loops and latest HRRR forecast, have removed
the ceiling at KBMI by 07z, then further northwest to KPIA by 09z.
Will need to keep an eye out for potential fog development, as
HRRR has been trying to develop areas of fog across the E/NE CWA
all evening. Latest obs show little or no obstruction to visby and
with dewpoints in the upper teens/lower 20s, do not think
widespread/dense fog will develop. Will however forecast slight
reductions in visby down to around 3-4 miles overnight. As the
high moves further away, strong southeasterly winds will develop
on Wednesday. Forecast soundings suggest gusts in the 20-25kt
range from late morning through the evening hours as the pressure
gradient continues to tighten. Next fast-moving storm system will
approach from the west late in the day, bringing an increase in
mid-level cloudiness but no precip through 06z Thu.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Barnes
SHORT TERM...kmd
LONG TERM...RC
AVIATION...Barnes
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1129 PM CST TUE JAN 27 2015
.DISCUSSION...
28/06Z TAF ISSUANCE.
&&
.AVIATION...
NO MAJOR CHANGES FROM PREVIOUS THINKING...ALTHOUGH A QUICK LOOK
OUTSIDE SHOWS SOME SHALLOW GROUND FOG BEGINNING TO DEVELOP HERE AT
THE LCH AIRPORT. LATEST HRRR SHOWS THE POTENTIAL FOR LOWER VSBYS
AT BPT AND POSSIBLY LCH...BUT GIVEN DRY AIRMASS IN PLACE ACRS THE
REGION...FOG SHOULD REMAIN PATCHY AND SHALLOW. INCLUDED TEMPO
GROUPS AT BPT/LCH FOR OCCASIONAL MVFR VSBYS BETWEEN 08-12Z...BUT
OTHERWISE VFR SHOULD PREVAIL. 24
&&
.PREV DISCUSSION... /ISSUED 844 PM CST TUE JAN 27 2015/
UPDATE...
THE LATEST UPPER AIR SOUNDING (28/00Z) FROM KLCH VERIFIES WHAT IS
SEEN ON WATER VAPOR IMAGERY...AS A DRY AIR MASS PREVAILS. SOME
LIGHT SOUTHERLY WINDS HAVE RISEN THE DEW POINTS SOME THIS EVENING
AT A FEW SPOTS. HOWEVER...WITH WINDS EXPECTED TO BE NEARLY
CALM...AND CLEAR SKIES WITH A DRY AIR MASS...OVERNIGHT LOW
TEMPERATURES STILL ON TRACK. WITH THIS...A FEW SITES MAY SEE SOME
SHALLOW GROUND FOG AS AIR TEMPERATURES LATER ON REACH DEW POINTS.
HOWEVER...THINKING IS THAT OVERALL AIR MASS IS TOO DRY TO SUPPORT
ANY SIGNIFICANT FOG DEVELOPMENT AND WILL NOT PLACE IN WEATHER
GRIDS AT THIS TIME. THEREFORE...NO CHANGES TO THE FORECAST FOR THE
EVENING UPDATE.
RUA
PREV DISCUSSION... /ISSUED 519 PM CST TUE JAN 27 2015/
DISCUSSION...
28/00Z TAF ISSUANCE.
AVIATION...
HIGH PRES RIDGING SW ACRS THE AREA WILL MOVE SLOWLY EAST THROUGH
WEDNESDAY. THE RESULT WILL BE VFR CONDITIONS WITH MAINLY SKC SKIES
AND LT VRBL WINDS WHICH WILL VEER MORE SELY DURING THE DAY
TOMORROW. 24
PREV DISCUSSION... /ISSUED 342 PM CST TUE JAN 27 2015/
DISCUSSION...
LATEST WATER VAPOR IMAGERY SHOWS SUBSIDENCE AND A RATHER DRY AIR
MASS ACROSS THE REGION. MEANWHILE...A WEAK SURFACE RIDGE ALSO LIES
ACROSS THE REGION. THE COMBINATION OF THE TWO IS HELPING TO PROVIDE
SUNNY SKIES...LIGHT WINDS...WHICH IN TURN IS ALLOWING FOR RATHER
WARM AIR TEMPERATURES FOR LATE JANUARY...FOR LOCATIONS AWAY FROM
THE GULF OF MEXICO...WITH READINGS IN THE MID TO UPPER 70S...SOME
15F DEGREES ABOVE NORMAL.
SURFACE RIDGE WILL SLIDE OFF TO THE EAST ON WEDNESDAY...WITH
SOUTHERLY WINDS OFF THE GULF GRADUALLY RETURNING TO THE FORECAST
AREA. THIS WILL HELP MODIFY THE AIR MASS AT THE SURFACE WITH THE
MORE MOIST AND COOLER GULF AIR HELPING TO KEEP TEMPERATURES ON
WEDNESDAY LOWER THAN WHAT IS OCCURRING TODAY. HOWEVER...THESE
VALUES WILL STILL BE SOME 10F DEGREES ABOVE NORMAL. THE INCREASE
IN GULF LOW LEVEL MOISTURE WILL ALSO BRING ABOUT THE CHANCE FOR
AT-LEAST PATCHY FOG DEVELOPMENT ON WEDNESDAY NIGHT INTO THURSDAY
MORNING.
A SHORT WAVE IS EXPECTED TO COME DOWN THE SIDE OF THE WESTERN U.S.
RIDGE LATE TOMORROW AND MOVE EASTWARD ACROSS THE PLAINS AND GREAT
LAKES THROUGH THURSDAY. THIS SYSTEM WILL HELP PUSH A WEAK COLD
FRONT ACROSS THE FORECAST AREA ON THURSDAY EVENING. MOISTURE
PROFILES DO HAVE PRECIPITABLE WATER VALUES NEARING 1 INCH WITH
MEAN RH BRIEFLY OVER 50 PERCENT AHEAD OF THE FRONT. HOWEVER...TIME
HEIGHTS SHOW THIS MOISTURE TO BE RATHER SHALLOW AND MAINLY BELOW
5K FEET. WITH UPPER LEVEL DYNAMICS ALSO STAYING WELL TO THE NORTH
WITH THIS FRONT...DO NOT EXPECT ANY SIGNIFICANT SHOWER ACTIVITY TO
DEVELOP WITH IT...AND WILL KEEP FRONTAL PASSAGE AS DRY.
COOLER CONDITIONS ARE EXPECTED BEHIND THE FRONT FOR FRIDAY WITH
HIGH TEMPERATURES BACK CLOSER TO SEASONAL NORMS.
CUT OFF UPPER LEVEL LOW IS STILL EXPECTED TO FORM OVER THE
SOUTHWEST U.S. BY THE END OF THE WEEK AND MOVE DOWN TOWARD THE
BAJA CALIFORNIA/NORTHWEST OLD MEXICO AREA OVER THE WEEKEND.
STRENGTHENING SOUTHERN JET WILL INCREASE PACIFIC MOISTURE ACROSS
THE FORECAST AREA...AS WELL AS PUSH DISTURBANCES EJECTING OUT OF
THE UPPER LEVEL LOW TOWARD THE FORECAST AREA. THIS WILL BRING
ABOUT A CHANCE OF SHOWERS BY SATURDAY.
SURFACE HIGH PRESSURE THAT BUILDS IN BEHIND THE COLD FRONT ON
THURSDAY NIGHT WILL PUSH OFF TO THE EAST BY SATURDAY NIGHT...AND
THIS WILL ALLOW SOUTHERLY WINDS TO DEVELOP DURING THIS TIME. THIS
WILL ALSO HELP INCREASE MOISTURE PROFILES AS LOW LEVEL GULF
MOISTURE WILL BE ADDED TO THE EAST PAC MOISTURE. PRECIPITABLE
WATER VALUES INCREASE FOR SATURDAY NIGHT INTO SUNDAY TO BETWEEN
1.3 AND 1.5 INCHES...WITH MEAN RH OVER 90 PERCENT...BOTH
RESPECTABLE NUMBERS FOR THE COOL SEASON. INCREASING LIFT FROM
DISTURBANCES IN THE SOUTHERN JET...AS WELL AS AN APPROACHING COLD
FRONT...THAT WILL MOVE ACROSS LATE SUNDAY...WILL TAP INTO THE
DECENT MOISTURE TO PROVIDE A LIKELIHOOD OF SHOWERS FOR THE
SATURDAY NIGHT INTO SUNDAY PERIOD. AT THIS POINT...SURFACE
INSTABILITY REMAINS RATHER MEAGER...SO WILL KEEP ACTIVITY AS JUST
SHOWERS...AND NOT MENTION THUNDER.
SHOWERS WILL GRADUALLY END FROM THE NORTHWEST TO THE SOUTHEAST ON
SUNDAY NIGHT AS DRIER AIR MOVES IN BEHIND THE FRONT.
RUA
MARINE...
LIGHT SOUTHERLY WINDS ARE EXPECTED ON WEDNESDAY AS A SURFACE HIGH
PRESSURE SYSTEM MOVES OFF TO THE EAST. THESE SOUTHERLY WINDS WILL
BRING BACK A MORE MOIST MARINE AIR MASS INTO THE REGION...AND WITH
DEW POINTS NEARING THE NEAR SHORE WATER TEMPERATURES...AT-LEAST
SOME PATCHY SEA FOG IS EXPECTED TO DEVELOP ON WEDNESDAY NIGHT INTO
THURSDAY. A COLD FRONT WILL MOVE ACROSS THE COASTAL WATERS ON
THURSDAY EVENING...ENDING FOG CHANCES AND BRINGING MODERATE NORTHERLY
WINDS.
WIND SPEEDS WILL REMAIN MODERATE AND BECOME EASTERLY ON SATURDAY
THEN SOUTHEASTERLY SATURDAY NIGHT INTO SUNDAY AS AN UPPER LEVEL
DISTURBANCE HELPS FORM AN AREA OF LOW PRESSURE OVER TEXAS...THAT
WILL MOVE ACROSS NORTHERN LOUISIANA. THIS SYSTEM WILL ALSO BRING
WIDESPREAD SHOWER ACTIVITY UNTIL ANOTHER COLD FRONT MOVES ACROSS
LATE SUNDAY.
RUA
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 45 69 51 73 / 0 0 0 0
KBPT 47 72 53 73 / 0 0 0 10
KAEX 41 71 49 73 / 0 0 0 0
KLFT 45 69 52 74 / 0 0 0 0
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
413 AM EST WED JAN 28 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...(THURSDAY THROUGH TUESDAY)
ISSUED AT 413 AM EST WED JAN 28 2015
FCST FOCUS IN THE MEDIUM AND EXTENDED RANGE WL TURN TO THE IMPACT OF
SEVERAL CLIPPER TYPE SHRTWVS THAT ARE FCST TO MOVE THRU A DEEPENING
UPR TROF IN ERN NAMERICA THAT WL BRING A RETURN OF BLO NORMAL TEMPS
MOST OF THIS TIME TO THE CWA. WITH THE RETURN OF ARCTIC AIR...LES WL
ALSO BE A CONCERN.
THU...THE FIRST OF THESE CLIPPER SHRTWVS IS CURRENTLY MOVING E THRU
ALBERTA AND IS FCST TO BE NEAR FAR NW LAKE SUP AT 12Z THU BEFORE
MOVING TO NEAR THE SAULT AT 00Z FRI TO THE N OF ANOTHER SHRTWV/SFC
LO PRES DRIFTING THRU THE LOWER LKS. THE MODELS INDICATE THERE WL BE
LTL IF ANY PHASING BTWN THESE SEPARTE DISTURBANCES...SO LINGERING
LIGHT SN IN THE WAA/DPVA/DEEP LYR QVECTOR CNVGC AHEAD OF THIS NRN
SHRTWV SHOULD BE DIMINISHING W-E ON THU MRNG AS ITS ATTENDANT COLD
FNT SWEEPS SE AND CLEARS THE CWA BY 18Z THU. NNW H925 WINDS FCST
AS HI AS 35 TO 40 KTS UNDER THE SHARP PRES GRADIENT BTWN THE
ASSOCIATED SFC LO MOVING INTO SE ONTARIO AND TRAILING ARCTIC HI
PRES BLDG THRU SCENTRAL CANADA WILL DRIVE MUCH COLDER AIR INTO THE
UPR LKS...DROPPING H85 TEMPS OVER THE UPR LKS TO ARND -20C BY 00Z
FRI. BEFORE THIS VERY COLD AIR SURGES INTO THE AREA IN THE
AFTN...NOT OUT OF THE QUESTION THERE COULD BE A BIT OF FREEZING DZ
MIXED WITH LINGERING LIGHT SN IN THE UPSLOPE AREAS NEAR LK SUP AS
SOME OF THE MODELS SHOW THE RELATIVELY SHALLOW MOIST LYR WARMER THAN
-10C FOR A COUPLE OF HRS. THE INFLUX OF ARCTIC AIR WL FAVOR
FALLING TEMPS AND LES IN THE AFTN. SO INCLUDED A SCHC OF SOME OF
THIS WINTRY MIX. BUT STRONG SUBSIDENCE RELATED TO THE VIGOROUS
CAA/DNVA/DEEP LYR QVECTOR DVGC IS FCST TO DROP THE INVRN BASE TO
BTWN H85-9 DURING THE DAY...WHICH ALONG WITH A NEUTRAL/ACYC LLVL
FLOW LIMIT THE INTENSITY OF THE SN SHOWERS DESPITE THE PRESENCE OF
THE DGZ WITHIN THE CONVECTIVE LYR. WITH THE STRONG CAA/NEAR SFC
DESTABILIZATION AND THE EXPECTED H925 WINDS...WIND GUSTS AT EXPOSED
AREAS NEAR LK SUP WL AT LEAST APRCH ADVY CRITERIA AND BRING ABOUT
CONSIDERABLE BLOWING SN. SINCE SN AMOUNTS WL BE MARGINAL...DID NOT
ISSUE ANY HEADLINES. WL MENTION THE GUSTY WINDS/BLOWING SN IN THE
HWO.
THU NGT...PERSISTENT COLD BUT SLOWLY DIMINISHING NNW WINDS IN
ADVANCE OF SLOWLY APRCHG SFC HI PRES WL BRING CONTINUED LES IN THE
FAVORED SN BELTS...BUT AS INVRN BASE SINKS FURTHER W-E UNDER THE
LARGER SCALE DNVA/DEEP LYR QVECTOR DVGC AHEAD OF APRCHG SHRTWV RDG
AXIS...FOLLOWED TREND OF PREVIOUS FCST TO SHOW DCRSG POPS ESPECIALLY
OVER THE W...WHERE THE H925 FLOW WL BECOME MORE SHARPLY ACYC. OVER
THE FAR W...THE LES MAY END COMPLETELY BY 12Z WITH FCST INVRN BASE
NEAR H95. AS FOR TEMPS...LOWS OVER THE INTERIOR W HALF MAY FALL BLO
ZERO IN A FEW SPOTS...BUT CONTINUED NW SFC-H925 FLOW WL FAVOR SOME
MODERATION OFF LK SUP AND LIMIT THE COVERAGE OF THE SUB ZERO MINS.
FRI...SFC HI PRES IS FCST TO SHIFT FM OVER MN INTO THE LOWER LKS. AS
WINDS BACK TO THE W...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 IS FCST TO SLIDE ESEWD THRU THE UPR LKS. SINCE
THIS DISTURBANCE IS FCST TO BE FAIRLY SHEARED OUT WITH ONLY
AN AREA OF RELATIVELY WEAK LARGE SCALE FORCING AND MSTR INFLOW WL BE
FAIRLY LIMITED...SUSPECT ACCOMPANYING SN WL BE ON THE LIGHT SIDE.
ANY LINGERING LIGHT SN OVER THE E ON SAT MRNG WL END WITH ARRIVAL OF
LARGER SCALE QVECTOR DVGC/MID LVL DRYING AND GIVE WAY TO SOME LES AS
COLDER AIR FOLLOWS THE SHRTWV AND DROPS H85 TEMPS TOWARD -20C AGAIN
LATE. BUT MORE DIFFLUENT ACYC H925 FLOW/LO SUBSIDENCE INVRN FCST IN
THE H875-9 RANGE WL BE LIMITING FACTORS FOR LES INTENSITY AGAIN.
EXTENDED...UNDER A NW FLOW ALF BTWN A MEAN TROF OVER ERN CANADA AND
A RDG OVER THE W...ARCTIC HI PRES IS FCST TO SINK SEWD FM WRN CANADA
ON SUN INTO UPR MS VALLEY ON MON AND THEN INTO THE OH RIVER VALLEY
ON TUE...BRINGING A CONTINUOUS FEED OF CNDN AIR AND H85 TEMPS
FALLING AS LO AS -25C BY EARLY NEXT WEEK. A NUMBER OF THE EXTENDED
MODELS ARE HINTING A LO PRES WL TAKE SHAPE IN THE MID MS RIVER VALLY
ON SUN ON THE LEADING EDGE OF THE INCOMING ARCTIC AIRMASS...BUT
INDICATE THE SFC LO WL TRACK ENE FAR ENUF TO THE SE OF UPR MI TO
KEEP THE ASSOCIATED PCPN SHIELD TO THE S AS WELL. BUT THE CHILL OF
THE INCOMING AIRMASS INDICATES LES WL BE A GOOD BET IN THE FAVORED
SN BELTS. THERE MAY BE SOME MODERATION NEXT TUE INTO WED AS THE SW
FLOW BTWN THE HI MOVING TOWARD THE MID ATLANTIC COAST AND ANOTHER
SHRTWV DROPPING SE THRU SCENTRAL CANADA DRAWS H85 TEMPS IN THE -10
TO -12C RANGE BACK INTO THE UPR LKS. BUT THIS CLIPPER MAY BRING SOME
LIGHT SN. AS THE TROF DEEPENS AGAIN FOLLOWING THE PASSAGE OF THIS
DISTURBANCE...ANOTHER VERY COLD AIRMASS MAY INVADE LATE NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1202 AM EST WED JAN 28 2015
BASED ON UPSTREAM CLOUDS OVER MUCH OF WI AND MN AND ALSO MID CLOUDS
SPREADING ACROSS THE UPPER LAKES FROM ONTARIO...MVFR CLOUD DECK
ACROSS MUCH OF WEST AND CENTRAL UPPER MI SHOULD PERSIST THROUGH MUCH
OF THE FCST PD AT ALL THE TAF SITES. THERE MAY BE A SLIGHT
IMPROVEMENT TO HIGH END MVFR BY WED AFTERNOON WITH INCREASED MIXING
FROM SOUTH WINDS. ANOTHER DISTURBANCE MOVING DOWN FROM ONTARIO WILL
BRING SOME LIGHT SNOW INTO THE AREA WED EVENING. THE BEST CHANCE FOR
IFR CONDITIONS IN SNOW WILL BE AT KCMX WHICH WILL BE IN CLOSER
PROXIMITY TO DEEPER MOISTURE AND BETTER FORCING WITH DISTURBANCE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 320 AM EST WED JAN 28 2015
A GALE WATCH HAS BEEN ISSUED FOR MUCH OF LAKE SUPERIOR LATE THURSDAY
MORNING INTO THURSDAY NIGHT...WITH N-NNW GALES OF 35-40KTS.
EXPECT HIGH PRESSURE CENTERED OVER OHIO THIS MORNING TO SHIFT E AND
OFF THE MID ATLANTIC COAST THURSDAY MORNING. A LOW TAKING SHAPE OVER
THE N PLAINS WILL MOVE TO AROUND CHICAGO ON THURSDAY...AND INTO N
NEW ENGLAND ON FRIDAY...WHILE ANOTHER LOW MOVES FROM S SASKATCHEWAN
TO N LAKE SUPERIOR AND QUEBEC. IN THEIR WAKE...EXPECT HIGH PRESSURE
OVER S CENTRAL CANADA TO FOLLOW INTO THE UPPER MIDWEST ON
FRIDAY...USHERING COLDER AIR INTO THE AREA. AS A RESULT...HEAVY
FREEZING SPRAY WILL BE POSSIBLE THURSDAY AFTERNOON THROUGH LATE
FRIDAY MORNING.
AS THIS HIGH MOVES INTO THE MID ATLANTIC STATES ON SATURDAY...A LOW
SHOULD MOVE ACROSS THE UPPER GREAT LAKES. THE LOW WILL THEN PUSH
OVER SE ONTARIO ON SUNDAY. N WINDS WILL AGAIN INCREASE TO 20-30KTS
SATURDAY-SUNDAY. LOOK FOR A RIDGE TO BUILD OVER W CANADA ON
SUNDAY...AND EXTEND A RIDGE INTO ONTARIO JUST N OF LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM THURSDAY AFTERNOON THROUGH LATE THURSDAY NIGHT
FOR LSZ267.
GALE WATCH FROM THURSDAY MORNING THROUGH LATE THURSDAY NIGHT FOR
LSZ266.
GALE WATCH FROM THURSDAY MORNING THROUGH LATE THURSDAY NIGHT FOR
LSZ264-265.
GALE WATCH FROM THURSDAY MORNING THROUGH THURSDAY EVENING FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KC
AVIATION...VOSS
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
321 AM EST WED JAN 28 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 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1202 AM EST WED JAN 28 2015
BASED ON UPSTREAM CLOUDS OVER MUCH OF WI AND MN AND ALSO MID CLOUDS
SPREADING ACROSS THE UPPER LAKES FROM ONTARIO...MVFR CLOUD DECK
ACROSS MUCH OF WEST AND CENTRAL UPPER MI SHOULD PERSIST THROUGH MUCH
OF THE FCST PD AT ALL THE TAF SITES. THERE MAY BE A SLIGHT
IMPROVEMENT TO HIGH END MVFR BY WED AFTERNOON WITH INCREASED MIXING
FROM SOUTH WINDS. ANOTHER DISTURBANCE MOVING DOWN FROM ONTARIO WILL
BRING SOME LIGHT SNOW INTO THE AREA WED EVENING. THE BEST CHANCE FOR
IFR CONDITIONS IN SNOW WILL BE AT KCMX WHICH WILL BE IN CLOSER
PROXIMITY TO DEEPER MOISTURE AND BETTER FORCING WITH DISTURBANCE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 320 AM EST WED JAN 28 2015
A GALE WATCH HAS BEEN ISSUED FOR MUCH OF LAKE SUPERIOR LATE THURSDAY
MORNING INTO THURSDAY NIGHT...WITH N-NNW GALES OF 35-40KTS.
EXPECT HIGH PRESSURE CENTERED OVER OHIO THIS MORNING TO SHIFT E AND
OFF THE MID ATLANTIC COAST THURSDAY MORNING. A LOW TAKING SHAPE OVER
THE N PLAINS WILL MOVE TO AROUND CHICAGO ON THURSDAY...AND INTO N
NEW ENGLAND ON FRIDAY...WHILE ANOTHER LOW MOVES FROM S SASKATCHEWAN
TO N LAKE SUPERIOR AND QUEBEC. IN THEIR WAKE...EXPECT HIGH PRESSURE
OVER S CENTRAL CANADA TO FOLLOW INTO THE UPPER MIDWEST ON
FRIDAY...USHERING COLDER AIR INTO THE AREA. AS A RESULT...HEAVY
FREEZING SPRAY WILL BE POSSIBLE THURSDAY AFTERNOON THROUGH LATE
FRIDAY MORNING.
AS THIS HIGH MOVES INTO THE MID ATLANTIC STATES ON SATURDAY...A LOW
SHOULD MOVE ACROSS THE UPPER GREAT LAKES. THE LOW WILL THEN PUSH
OVER SE ONTARIO ON SUNDAY. N WINDS WILL AGAIN INCREASE TO 20-30KTS
SATURDAY-SUNDAY. LOOK FOR A RIDGE TO BUILD OVER W CANADA ON
SUNDAY...AND EXTEND A RIDGE INTO ONTARIO JUST N OF LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...VOSS
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1203 AM EST WED JAN 28 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 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1202 AM EST WED JAN 28 2015
BASED ON UPSTREAM CLOUDS OVER MUCH OF WI AND MN AND ALSO MID CLOUDS
SPREADING ACROSS THE UPPER LAKES FROM ONTARIO...MVFR CLOUD DECK
ACROSS MUCH OF WEST AND CENTRAL UPPER MI SHOULD PERSIST THROUGH MUCH
OF THE FCST PD AT ALL THE TAF SITES. THERE MAY BE A SLIGHT
IMPROVEMENT TO HIGH END MVFR BY WED AFTERNOON WITH INCREASED MIXING
FROM SOUTH WINDS. ANOTHER DISTURBANCE MOVING DOWN FROM ONTARIO WILL
BRING SOME LIGHT SNOW INTO THE AREA WED EVENING. THE BEST CHANCE FOR
IFR CONDITIONS IN SNOW WILL BE AT KCMX WHICH WILL BE IN CLOSER
PROXIMITY TO DEEPER MOISTURE AND BETTER FORCING WITH DISTURBANCE.
&&
.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...VOSS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS DULUTH MN
353 AM CST WED JAN 28 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 353 AM CST WED JAN 28 2015
LOW PRESSURE WAS ORGANIZING IN THE DAKOTAS AT 08Z WITH A FRONTAL
BOUNDARY EXTENDING NORTHEASTWARD INTO SOUTHERN MANITOBA AND INTO NW
ONTARIO. IN THE WAA AHEAD OF THIS SYSTEM...SOME LIGHT SNOW WAS
FALLING OVER THE ARROWHEAD WITH LITTLE ACCUMULATION. NORTH OF THE
CANADIAN BORDER...SOME LIGHT FREEZING RAIN WAS OCCURRING RIGHT NEAR
THE FRONT FROM WINNIPEG TO NEAR DRYDEN. LATEST SHORT TERM HRRR AND
RAP KEEP THIS FREEZING RAIN NORTH OF THE BORDER. THE LIGHT SNOW OVER
THE ARROWHEAD IS EXPECTED TO SLOWLY END BY NOON. LITTLE ADDITIONAL
ACCUMULATION IS ANTICIPATED.
BY THIS AFTERNOON...THE SFC LOW MOVES EASTWARD WITH THE LOW CENTER
BEGINS TO REORGANIZE AND DRIFT INTO SOUTHWEST IOWA BY 00Z THURSDAY.
MEANWHILE...A MID LEVEL LONG WAVE TROF MOVES OVER THE WESTERN GREAT
LAKES. SOME MODEL DIFFERENCES BEGIN TO REVEL THEMSELVES WITH RESPECT
TO QPF PLACEMENT AND THE AMOUNT OF COLD AIR FORECAST TO DROP INTO
THE FORECAST AREA. THE GFS IS THE MOST ROBUST AND FURTHEST SOUTH
WHILE THE ECMWF HAS LIMITED QPF AND KEEPS IT NEAR THE CANADIAN
BORDER. HAVE USED A BLENDED APPROACH AND KEPT POPS TO THE NORTHERN
HALF OF THE FORECAST AREA BY LATE AFTERNOON. PRECIPITATION TYPE WILL
BE ALL SNOW. LATEST FORECAST SOUNDINGS ARE NOT SUPPORTING THE
MENTION OF FREEZING RAIN OR FREEZING DRIZZLE AND HAVE REMOVED.
TONIGHT...THE MID LEVEL LONG WAVE TROF MOVES EAST OF THE FORECAST
AREA BY 12Z THURSDAY. THIS PUSHES THE SFC LOW EAST OF THE AREA AS
WELL. BEHIND THIS SYSTEM...A TIGHTENING PRESSURE GRADIENT MOVES OVER
THE WESTERN GREAT LAKES AS HIGH PRESSURE BUILDS INTO THE WESTERN
DAKOTAS. MADE SOME MINOR CHANGES TO THE POPS AND THEIR TIMING ACROSS
THE AREA...WITH THE SNOW ENDING LATE TONIGHT OVER THE SOUTHWEST
PORTION OF THE FORECAST AREA TO THE TWIN PORTS LATE TONIGHT.
FORECAST SOUNDINGS INDICATE THAT THE PRECIPITATION TYPE WILL BE ALL
SNOW AND HAVE REMOVED THE MENTION FREEZING RAIN/FREEZING DRIZZLE AND
SLEET. SNOW AMOUNTS WILL BE LIGHT WITH THE HIGHEST AMOUNTS OF AROUND
ONE HALF INCH FOUND ALONG THE CANADIAN BORDER.
ON THURSDAY...ONLY MADE SOME MINOR CHANGES TO THE POPS AND WEATHER
AS MODELS ARE IN VERY GOOD AGREEMENT. WILL STILL HAVE GUSTY WINDS AS
THE TIGHT PRESSURE GRADIENT REMAINS UNTIL LATE AFTERNOON WHEN THE
AFOREMENTIONED HIGH PRESSURE MOVES INTO THE RED RIVER VALLEY. A NW
WIND OVER LAKE SUPERIOR AND CAA WILL LEAD TO SOME LAKE EFFECT SNOW
ALONG THE HIGHER TERRAIN OF THE SOUTH SHORE. SNOW AMOUNTS WILL BE
LIGHT HOWEVER AS DEEP COLD AIR IS LACKING UNTIL LATE AFTERNOON.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 353 AM CST WED JAN 28 2015
MUCH COLDER AIR ON THE WAY FOR THIS WEEKEND WITH A CHANCE FOR SNOW
FROM...YOU GUESSED IT...ANOTHER WEAK CLIPPER SYSTEM. THE LARGE SCALE
PATTERN WILL UNDERGO SOME CHANGES THROUGH THE LONG TERM THAT WILL
/AT LEAST TEMPORARILY/ PUT A STOP TO WHAT HAS BEEN A LONG PERIOD OF
WEAK /AND FRANKLY DISAPPOINTING FOR SNOW LOVERS/ CLIPPERS.
TEMPERATURES WILL DROP FROM WHAT HAS BEEN A VERY MILD PATTERN TO A
COLDER REGIME...ENDING THE LAST WEEK OF JANUARY WITH TEMPS SIMILAR
TO THE FIRST WEEK OF THE MONTH.
ON THE SYNOPTIC SCALE A SERIES OF STRONG ARCTIC AIR MASSES WILL DROP
DOWN INTO THE NORTHERN PLAINS AND UPPER MIDWEST. LATE THIS WEEK AN
AREA OF HIGH PRESSURE WILL MOVE OVER THE AREA THURSDAY NIGHT
FOLLOWED BY A WEAK CLIPPER ON FRIDAY/FRIDAY NIGHT. THEN LATE IN THE
WEEKEND A DEEP LONGWAVE TROUGH AT MID-LEVELS WILL DESCEND OVER THE
MIDWEST LEADING TO VERY COLD AIR ALOFT...850MB TEMPS APPROACHING THE
COLDEST 10 PERCENT OF CLIMATOLOGY IN THE MID -20S C /COMPARED TO 00Z
TODAY WHEN THEY WERE IN THE WARMEST 10 PERCENT OF CLIMO AT AROUND
0C/.
BEST CHANCE FOR SNOWFALL ACROSS THE REGION WILL BE LATE FRIDAY
AFTERNOON INTO FRIDAY NIGHT A CLIPPER MOVES ACROSS. GFS AND ECMWF IN
GOOD AGREEMENT ON TIMING...WITH ECMWF PESSIMISTIC ON INTENSITY AND
GFS A LITTLE STRONGER WITH A DEEPER MOISTURE PROFILE. GEM WAS SLOWER
AND NOT AS INTENSE OVERALL...BUT THIS WAS A PRETTY BIG CHANGE FROM
12Z GEM WHICH WAS FASTER AND MUCH MORE AGGRESSIVE ON PRECIP. AT THIS
POINT IT LOOKS LIKE A QUICK INCH OR TWO FOR NORTHERN MINNESOTA NORTH
OF HIGHWAY TWO. OTHERWISE NO SIGNIFICANT CHANCES FOR PRECIP IN THE
SEVEN DAY FOR MUCH OF THE REGION...WITH THE EXCEPTION OF LAKE EFFECT
SNOWFALL ALONG PORTIONS OF THE SOUTH SHORE OF LAKE SUPERIOR.
LAKE EFFECT SNOWFALL WILL BE PRESENT THROUGH MUCH OF THE LONG TERM
PERIOD. ON THURSDAY NIGHT CONDITIONS WILL BE GOOD FOR LAKE EFFECT
SNOWFALL ALONG THE HIGHER TERRAIN OF IRON/ASHLAND COUNTIES WITH
STEEP LOW LEVEL LAPSE RATES THROUGH 850MB AND GREAT NORTH/NORTHWEST
FLOW OVER THE LAKE. ICE COVERAGE ON THE SOUTH SHORE MAY LIMIT THE
INTENSITY OF LAKE EFFECT SNOWFALL...AND OPTED TO LEAVE NORTHERN
BAYFIELD COUNTY OUT OF HIGHER CHANCES FOR LAKE EFFECT SNOWFALL DUE
TO WHAT WOULD BE A VERY LIMITED FETCH LENGTH. LOW LEVEL MOISTURE
WILL ALSO BE A FACTOR AS NAM/GFS/ECMWF DEPICT A NEAR-SURFACE DRY
LAYER...SO IT MAY TAKE A WHILE TO SATURATE LOW LEVELS AND THUS LIMIT
SNOWFALL AMOUNTS. LAKE EFFECT WILL TAPER OFF AS HIGH PRESSURE MOVES
OVER LAKE SUPERIOR ON FRIDAY AFTERNOON...BUT RAMP BACK UP AGAIN ON
SATURDAY AND THROUGH ABOUT TUESDAY DUE TO THE VERY COLD AIRMASS THAT
WILL BE IN PLACE.
TEMPS WILL BE ON A DOWNWARD TREND...AND HAVE ADJUSTED SOME OF THE
USUAL COLD SPOTS A LITTLE COLDER THAN INITIAL GUIDANCE TO ACCOUNT
FOR THE ARCTIC HIGHS THAT WILL BE OVER NORTHEASTERN MINNESOTA IN THE
LONG TERM. HIGHS IN THE MID TEENS TO MID 20S ON SATURDAY...THEN THE
SINGLE DIGITS ON SUNDAY AND MONDAY BEFORE RECOVERING TO THE TEENS
TUESDAY. LOWS NEAR ZERO TO TEN OR MORE BELOW ZERO ON THURSDAY
NIGHT...MILD FRIDAY NIGHT DUE TO WEAK SOUTHERLY WINDS...THEN 0 TO
-15 SATURDAY NIGHT AND 10 TO 20 BELOW ZERO ON SUNDAY NIGHT. MONDAY
MORNING WILL BE THE COLDEST PERIOD IN THE LONG TERM WITH WIND CHILL
VALUES OF 25 TO 35 BELOW ZERO...AND COLD SPOTS IN THE TIP OF THE
ARROWHEAD REGION NEAR 40 BELOW ZERO.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1140 PM CST TUE JAN 27 2015
MVFR CEILINGS WERE ADVANCING NORTH THROUGH KFOZ HEADING TOWARD
KINL. AN AREA OF VFR CONDITIONS ALSO EXTENDED FROM KINL THROUGH
KTWM INTO KHYR. THE RAP SHOWS VFR CEILINGS WILL PREVAIL OVER
EASTERN PORTIONS OF THE NORTHLAND FOR A TIME TONIGHT...BUT SHOULD
LOWER ON WEDNESDAY AS LOW LEVEL WAA STRENGTHENS AGAIN. THE FGEN
BAND OF SNOW OVER FAR NORTHEAST MINNESOTA HAS DIMINISHED THIS
EVENING AND WE EXPECT SOME SPOTTY SNOW OVERNIGHT.
AN AREA OF LOW PRESSURE WILL MOVE INTO THE AREA ON WEDNESDAY AND
WILL BRING A THREAT FOR SOME MIXED PRECIPITATION TO THE AREA. AT
THIS TIME...WE LIMITED THE MENTION DUE TO UNCERTAINTY IN COVERAGE.
MUCH OF THE GUIDANCE AT THIS TIME SUGGESTS THE COVERAGE WILL BE
LIMITED UNTIL LATE IN THE PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 31 24 24 -1 / 10 50 10 0
INL 32 16 16 -10 / 30 60 10 0
BRD 34 22 22 5 / 10 40 0 0
HYR 33 27 27 -2 / 10 50 20 0
ASX 34 27 27 2 / 10 50 20 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...GSF
LONG TERM...JJM
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
1141 PM CST TUE JAN 27 2015
.UPDATE...
ISSUED AT 843 PM CST TUE JAN 27 2015
AN AREA OF FGEN OVER FAR NORTHEAST MINNESOTA HAS LED TO NARROW
BANDS OF SNOW...CAPABLE OF PRODUCING A HALF TO THREE QUARTERS OF
AN INCH OF SNOW OVER A NARROW AREA. WE INCREASED POPS AND WILL
CONTINUE TO MAKE ADJUSTMENTS THROUGH THE LATE EVENING AS THE BANDS
MOVE EAST AND NORTH.
UPDATE ISSUED AT 643 PM CST TUE JAN 27 2015
WE UPDATED TO INCREASE THE CHANCE FOR SNOW...ESPECIALLY ACROSS FAR
NORTHERN MINNESOTA. HIGH RES MODELS SUPPORT A BETTER CHANCE
THERE. FURTHER SOUTH...FORECAST SOUNDINGS SHOW DRIER AIR PRESENT
IN THE LOW/MID LEVELS WHICH WILL LEAD TO A LESSER CHANCE FOR SNOW
OR JUST SOME FLURRIES.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 247 PM CST TUE JAN 27 2015
MAIN CONCERNS IN THE SHORT TERM ARE FOCUSED AROUND THE POTENTIAL
FOR LIGHT SNOW ALONG THE BORDERLAND TONIGHT AND WEDNESDAY
MORNING...AND THE NEXT SHOT OF A WINTRY MIX WEDNESDAY AND WED
NIGHT. A MIX OF SNOW...SLEET AND FREEZING RAIN IS POSSIBLE...AND
WINTER WEATHER HEADLINES MAY BE NEEDED.
WEAK UPPER LEVEL RIDGE ORIENTED FROM WRN QUEBEC INTO THE UPPER
MIDWEST THIS AFTERNOON WITH AN ASSOCIATED SFC RIDGE AXIS FURTHER
TO THE E/SE. ON THE WRN EDGE OF THIS RIDGE THERE IS AN AREA OF
FAIRLY STRONG WAA OVER THE NRN PLAINS. INDICATIVE OF THIS WARM
AIR ARE THE UPPER 60 AND LOWER 70 DEGREE TEMPERATURES IN WRN SOUTH
DAKOTA. CONDITIONS ARE NOT AS PLEASANT ACROSS THE NORTHLAND WITH
MUCH OF THE REGION ENSHROUDED IN CLOUD COVER AND TEMPERATURES IN
THE UPPER 20S AND LOWER 30S. STILL NOT TOO BAD FOR LATE JANUARY.
THE DOME OF WARM AIR OVER THE PLAINS TODAY WILL GRADUALLY SHIFT
TO THE SOUTHEAST AS THE RIDGE BREAKS DOWN AND THE NEXT UPPER S/W
AND SFC LOW MOVE IN FROM THE NW. A WEAK LEAD WAVE...AHEAD OF THE
MAIN TROUGH WILL PASS THROUGH WRN ONTARIO AND BRUSH PORTIONS OF
THE ARROWHEAD AND BORDERLAND REGION WITH LIGHT SNOW TONIGHT AND
WEDNESDAY MORNING. ONLY LIGHT SNOW AMTS ARE EXPECTED.
THE BRUNT NEXT WINTER SYSTEM WILL BEGIN TO MOVE INTO N-CENTRAL MN
LATE WEDNESDAY MORNING WITH A MIX OF SNOW AND FREEZING
RAIN/DRIZZLE...THAT WILL SPREAD TO THE SOUTH THROUGH THE
AFTERNOON. AS THE PRECIPITATION MOVES IN...A COLDER AIR MASS WILL
AS WELL. BUT NOT BEFORE THE WEDGE OF WARM AIR IN THE MID LEVELS
CAN ALTER THE PRECIPITATION TYPE TO A WINTRY MIX...MAINLY ALONG
AND SOUTH OF A LINE PARALLEL TO HIGHWAY 2. THE BULK OF THE
PRECIP...NAMELY HEAVY SNOW...WITH THIS SYSTEM WILL FALL NORTH OF
THE INTERNATIONAL BORDER...CLOSER TO THE UPPER LEVEL FORCING AND
ALONG A AREA OF ENHANCED MID LEVEL F-GEN. HOWEVER...NE MN AND NW
WI WILL SEE LIGHTER PRECIP...BUT STILL ENOUGH TO CAUSE POTENTIALLY
HAZARDOUS TRAVEL/ROAD CONDITIONS DURING THE DAY WED AND WED NIGHT.
COULD SEE 1 TO 2 INCHES OF SNOW ACROSS THE ARROWHEAD...AND LIGHT
ICE ACCUMULATIONS POSSIBLE FROM WASKISH TO THE TWIN PORTS AND INTO
NW WI. ANOTHER ROUND OF WINTER WEATHER ADVISORIES COULD BE NEEDED.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 247 PM CST TUE JAN 27 2015
A STRONG COLD FRONT WILL MOVE THROUGH THE NORTHLAND EARLY THURSDAY
IN THE WAKE OF A PASSING CLIPPER SYSTEM. THERE WILL BE STRONG COLD
AIR ADVECTION DURING THE DAY. PARTLY TO MOSTLY CLOUDY SKIES SHOULD
ENSURE THAT THE CAA RESULTS IN FALLING TEMPERATURES THROUGH THE
DAY...SO HIGHS WILL BE IN THE MORNING. THE NAM12 AND GFS MODEL
SOUNDINGS ARE SHOWING A MIXING LAYER PACKING QUITE A BIT OF
NORTHERLY WIND. NOT SURE IF THE LAPSE RATES WILL BE SUFFICIENT
ENOUGH TO DRAW DOWN THE 35 TO 40 KNOTS OF WIND THOSE SOUNDINGS ARE
SHOWING IN THE MIXING LAYER...BUT SUBSTANTIALLY INCREASING THE
SUSTAINED WIND AND WIND GUST FORECAST OVER THE PREVIOUS FORECAST
SEEMED WARRANTED. THERE WILL LIKELY BE AT LEAST WIDESPREAD NNW WINDS
OF 10 TO 20 MPH WITH GUSTS UP TO 30 MPH. THERE COULD BE SNOW
FLURRIES AND LIGHT ACCUMULATING SNOW...PRIMARILY IN NW WISCONSIN DUE
TO LAKE ENHANCEMENT. OVERALL...THURSDAY LOOKS LIKE A BLUSTERY DAY
WHICH WILL PUT AN END TO OUR RECENT RELATIVELY WARM WEATHER.
HIGH PRESSURE WILL MOVE INTO THE NORTHLAND THURSDAY NIGHT. THE LIGHT
WINDS WILL PROMOTE RADIATIONAL COOLING...BUT LINGERING CLOUD COVER
COULD PROMOTE THE OPPOSITE. IT APPEARS THERE WILL BE NW TO WNW WINDS
OF 10 TO 15 KNOTS ALOFT THROUGH THE NIGHT...DESPITE THE SURFACE
WINDS BECOMING VERY LIGHT. THE NW WINDS ALOFT COULD MAINTAIN THE
CLOUD COVER. NONETHELESS...LOWERED THE THURSDAY NIGHT LOW
TEMPERATURES BASED ON A WIDE BLEND. LOWS WILL LIKELY BE NEAR OR UP
TO SEVERAL DEGREES BELOW ZERO.
SOUTHWEST FLOW WILL DEVELOP FRIDAY IN THE WAKE OF THE PASSING HIGH
PRESSURE AND IN ADVANCE OF AN APPROACHING CLIPPER IN SASKATCHEWAN
AND MANITOBA. THE INFLUX OF WARMER AIR SHOULD ALLOW TEMPERATURES TO
RECOVER 15 TO 20 DEGREES BY FRIDAY AFTERNOON. HIGHS WILL BE ABOUT 5
DEGREES BELOW NORMAL.
ANOTHER WEAK CLIPPER SYSTEM WILL MOVE THROUGH THE NORTHLAND FRIDAY
NIGHT AND EARLY SATURDAY. THIS COULD BRING ANOTHER DUSTING OF SNOW
TO THE FORECAST AREA. THE NORTHERN FA APPEARS TO HAVE THE BEST
CHANCE OF SEEING THIS DUSTING.
A PROLONGED PERIOD OF COLD N TO NW FLOW WILL DEVELOP SATURDAY IN THE
WAKE OF THE CLIPPER AND ITS COLD FRONT...AND CONTINUE THROUGH
MONDAY. THIS WILL LEAD TO ANOTHER COOLING TREND. TEMPERATURES WILL
LIKELY BE 15 TO 20 DEGREES BELOW NORMAL DURING THIS TIME. WIND CHILL
TEMPERATURES MIGHT FLIRT WITH READINGS OF -20 DEGREES OR COLDER AT
NIGHT...BOTH SUNDAY NIGHT AND MONDAY NIGHT. THE SNOWBELT REGION OF
NW WISCONSIN WILL LIKELY GET LIGHT LAKE EFFECT SNOW SUNDAY INTO
MONDAY DUE TO THE COLD NW FLOW OVER WESTERN LAKE SUPERIOR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1140 PM CST TUE JAN 27 2015
MVFR CEILINGS WERE ADVANCING NORTH THROUGH KFOZ HEADING TOWARD
KINL. AN AREA OF VFR CONDITIONS ALSO EXTENDED FROM KINL THROUGH
KTWM INTO KHYR. THE RAP SHOWS VFR CEILINGS WILL PREVAIL OVER
EASTERN PORTIONS OF THE NORTHLAND FOR A TIME TONIGHT...BUT SHOULD
LOWER ON WEDNESDAY AS LOW LEVEL WAA STRENGTHENS AGAIN. THE FGEN
BAND OF SNOW OVER FAR NORTHEAST MINNESOTA HAS DIMINISHED THIS
EVENING AND WE EXPECT SOME SPOTTY SNOW OVERNIGHT.
AN AREA OF LOW PRESSURE WILL MOVE INTO THE AREA ON WEDNESDAY AND
WILL BRING A THREAT FOR SOME MIXED PRECIPITATION TO THE AREA. AT
THIS TIME...WE LIMITED THE MENTION DUE TO UNCERTAINTY IN COVERAGE.
MUCH OF THE GUIDANCE AT THIS TIME SUGGESTS THE COVERAGE WILL BE
LIMITED UNTIL LATE IN THE PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 25 33 23 24 / 30 30 50 10
INL 27 32 14 16 / 60 30 60 10
BRD 27 34 21 22 / 10 20 40 0
HYR 24 34 27 27 / 10 10 50 20
ASX 25 36 27 28 / 30 10 50 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 HASTINGS NE
352 AM CST WED JAN 28 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 344 AM CST WED JAN 28 2015
BEEN ANOTHER QUIET NIGHT ACROSS THE AREA...THANKS TO AN UPPER
LEVEL SHORTWAVE RIDGE AXIS THAT HAS BEEN STEADILY MAKING ITS WAY
EAST THROUGH THE PLAINS...PUSHED BY AN UPPER LEVEL DISTURBANCE
MOVING INTO WRN PORTIONS OF WY. AT THE SURFACE...THE PATTERN OVER
THE CWA IS ONCE AGAIN ON THE WEAKER SIDE...WITH A TROUGH AXIS SET
UP OVER THE HIGH PLAINS...RESULTING IN LIGHT AND AT TIMES VARIABLE
WINDS. TEMPS EARLY THIS MORNING AT 3 AM RANGE ANYWHERE FROM THE
MID 20S IN THE NORTH TO MID 40S IN THE FAR SWRN CORNER OF THE CWA.
THE MAIN STORY THROUGH THE SHORT TERM PERIOD LIES WITH THAT UPPER
LEVEL DISTURBANCE PUSHING INTO WY THIS MORNING...AND THE
ACCOMPANYING FRONTAL BOUNDARY IT WILL PUSH THROUGH THE CWA. MODELS
ARE IN PRETTY GOOD AGREEMENT WITH THE TIMING OF THIS
DISTURBANCE...SHOWING IT MOVING INTO THE NEB PANHANDLE NEAR MIDDAY
TODAY...BY 00Z THIS EVENING THE TROUGH AXIS LOOKS TO BE EXTENDING
THROUGH THE HEART OF THE CWA...BEFORE PUSHING OFF TO THE MISSOURI
RIVER AREA BY MIDNIGHT TONIGHT. A WEAKER SECOND MID LEVEL
DISTURBANCE QUICK ON THE HEELS OF THE MAIN ONE IS FORECAST TO BE
WORKING INTO THE AREA AS WE GET INTO THE EARLY MORNING HOURS
THURSDAY. EVEN WITH THERE ACTUALLY BEING A SYSTEM TO TALK
ABOUT...MODELS /INCLUDING THE MORE SHORT TERM HIRES LIKE THE WRF/
OVERALL CONTINUE TO BE IN GOOD AGREEMENT SHOWING CONDITIONS
REMAINING DRY...JUST NOT A LOT OF MOISTURE TO WORK WITH. THAT
BEING SAID...SOME MODELS ARE HINTING AT THE POTENTIAL OF SOME VERY
LIGHT PRECIP FALLING THIS EVENING/OVERNIGHT...BUT KEEP THAT SIGNAL
JUST OUTSIDE THE N/NERN BORDERS OF THE CWA. WILL BE SOMETHING FOR
THE DAY SHIFT TO MONITOR WITH THE 12Z RUN OF MODELS THIS MORNING.
AT THE SFC...WINDS WILL REMAIN ON THE LIGHTER SIDE THIS
MORNING...BEFORE THE WIND SHIFT OF THE COLD FRONT ACCOMPANYING
THIS SYSTEM PASSES THROUGH THE CWA...WHICH MODELS SHOW PUSHING
ABOUT HALFWAY THROUGH THE CWA BY MID MORNING AND MAKING IT TO THE
ERN FRINGE OF THE CWA AROUND MIDDAY. THIS WILL USHER IN A PUSH OF
GUSTY W/NWRLY WINDS /15 TO 25 MPH IS FORECAST/...BUT THE MAIN PUSH
OF COLDER AIR IS LAGGING BEHIND. TEMPS ALOFT COOL A TOUCH DURING
THE DAY...BUT HIGHS ARE STILL FORECAST TO BE WELL ABOVE
AVERAGE...THANKS TO THE MILD AIR/DOWNSLOPING WINDS. NOT EXPECTED
TO BE AS WARM AS TUESDAY...BUT TRENDED HIGHS TOWARD THE MAV AND
RAP /WHICH DID PRETTY WELL TUESDAY/...WHICH PUTS THE MAJORITY OF
THE CWA AT LEAST INTO THE MID 60S /THE EXCEPTION AGAIN IS THE
E/NERN PORTIONS/...WITH HIGHS NEAR 70 FORECAST IN NC KS. IF TEMPS
PAN OUT AS FORECAST...IT WOULD SET A NEW RECORD HIGH TEMPS IN
GRAND ISLAND. BUT CONFIDENCE ISNT THE HIGHEST...AS THERE ARE
MODELS THAT SAY IT WILL FALL SHORT OF/MAYBE TIE THE RECORD OF 63
DEGREES. THE RECORD AT HASTINGS IS 69 DEGREES...AND THE RAP IS
BASICALLY THE ONLY ONE SHOWING THE POTENTIAL FOR TEMPS TO MAKE A
RUN AT THAT RECORD. FIRE WX CONCERNS ARISE AGAIN...SEE FIRE
WEATHER SECTION BELOW FOR ADDITIONAL INFORMATION.
THIS EVENING/TONIGHT...ONE MIGHT THINK THAT WINDS WE HAVE THIS
AFTERNOON WOULD TAPER OFF...BUT WITH THE MAIN PUSH OF COLD AIR
ADVECTION...BETTER PRESSURE RISES/TIGHTER PRESSURE GRADIENT...AND
STRONGER WINDS ALOFT TO TAP INTO...THATS NOT THE CASE. MADE SOME
ADJUSTMENTS TO WIND SPEEDS...WHICH WILL BE ON A SECOND INCREASE
THIS EVENING...AND BY MIDNIGHT TONIGHT SPEEDS IN THE 25 TO 30
MPH RANGE WILL BE POSSIBLE...MAINLY ACROSS OUR SC NEB COUNTIES.
LOOKS TO REMAIN BREEZY INTO THE EARLY MORNING HOURS THURSDAY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 344 AM CST WED JAN 28 2015
GUIDANCE SUGGESTS AN UPPER TROPOSPHERIC SHORT WAVE WILL BE NOTED
OVER THE MID-MISSISSIPPI VALLEY TO START THE LONG-TERM FORECAST
PERIOD AT 12Z THURSDAY...THUS HELPING PROVIDE NORTHWESTERLY UPPER
TROPOSPHERIC FLOW OVER OUR AREA. THIS NORTHWESTERLY FLOW IS
EXPECTED TO PERSIST OVER OUR AREA THURSDAY INTO THURSDAY NIGHT
BEFORE THE APPROACH OF AN UPPER TROPOSPHERIC LONGWAVE TROUGH AXIS
PROMOTES QUASI-ZONAL TO SOUTHWESTERLY UPPER TROPOSPHERIC FLOW
FRIDAY THROUGH SATURDAY. THIS UPPER TROPOSPHERIC TROUGH AXIS IS
EXPECTED TO CLEAR OUR AREA SATURDAY NIGHT...THUS ALLOWING FOR
NORTHWESTERLY UPPER TROPOSPHERIC FLOW OVER OUR AREA AS WE HEAD
INTO THE EARLY PART OF NEXT WEEK.
GUIDANCE SUGGESTS AN OVERALL LACK IN OMEGA WILL KEEP US DRY
THURSDAY...THURSDAY NIGHT AND THROUGH THE DAY FRIDAY...AND SUCH
HAS BEEN PRESENTED IN THE OFFICIAL FORECAST.
STARTING FRIDAY NIGHT AND CONTINUING INTO SATURDAY...SATURDAY
NIGHT AND PERHAPS EARLY SUNDAY...UPPER TROPOSPHERIC THERMAL
ADVECTION AHEAD OF THE APPROACHING TROUGH AXIS IS EXPECTED TO
PROMOTE ENOUGH OMEGA FOR PRECIPITATION PRODUCTION ACROSS MUCH OF
THE REGION...INCLUDING OUR CWA. THE OPERATIONAL GFS AND EC
CONTINUE TO COME INTO BETTER AGREEMENT BY SUGGESTING PRECIPITATION
WILL MOVE IN FROM SOUTHWEST TO NORTHEAST ACROSS MUCH OF OUR
AREA...AGAIN BEGINNING FRIDAY NIGHT...WITH WIDESPREAD
PRECIPITATION THEN CONTINUING ACROSS THE AREA SATURDAY AND
SATURDAY NIGHT BEFORE MOVING EAST...ALONG THE UPPER TROPOSPHERIC
TROUGH AXIS...AROUND OR SHORTLY AFTER SUNRISE SUNDAY. INTERESTING
TO NOTE THAT THE NAM...WHICH THROUGH 84 HOURS IS JUST NOW UP TO
12Z SATURDAY...APPEARS TO KEEP THE PRIMARY AXIS OF OMEGA WELL TO
OUR SOUTHEAST AND AS A RESULT...KEEPS US DRY THROUGH 12Z SATURDAY.
ALTHOUGH IT WILL BE VERY INTERESTING TO SEE HOW THE NAM UNFOLDS
THROUGH THE NEXT FEW RUNS...GIVEN THE AFOREMENTIONED DATA FROM
THE OPERATIONAL GFS AND EC...IT SEEMS PRUDENT TO PRESENT YET
ANOTHER INCREASE IN POPS FOR THIS WEEKEND AND 30-60% POPS ARE NOW
SHOWN IN THE OFFICIAL FORECAST...WITH THE HIGHEST POPS RELEGATED
TO OUR SOUTHEAST WHICH IS WHERE GUIDANCE SUGGESTS THE STRONGEST
OMEGA AND MOST EFFICIENT PRECIPITATION PRODUCTION WILL RESIDE
DURING THIS UPCOMING STORM SYSTEM.
ONCE PRECIPITATION COMES TO AN END ON SUNDAY...GUIDANCE SUGGESTS
DRY CONDITIONS SHOULD BE OBSERVED SUNDAY NIGHT THROUGH
TUESDAY...AND SUCH HAS BEEN PRESENTED IN THE OFFICIAL FORECAST.
ALTHOUGH IT APPEARS PRECIPITATION COULD START OUT AS RAIN FRIDAY
NIGHT...FORECAST PROXIMITY SOUNDINGS FROM ACROSS THE CWA...PER THE
OPERATIONAL GFS AND EC...SUGGEST THE LOWER TROPOSPHERE WILL BE
SUPPORTIVE FOR SNOWFALL AT THE SURFACE BY 12Z SATURDAY AND
CONTINUING INTO SUNDAY. THAT SAID...WITH A CONTINUED
SOUTH/SOUTHEASTERLY BOUNDARY- LAYER WIND FIELD EXPECTED THROUGH
THE DAY SATURDAY...THERE IS STILL AT LEAST AN OPPORTUNITY FOR SOME
TEMPERATURE RECOVERY NEAR THE SURFACE DURING THE DAY SATURDAY AND
SUPERBLEND RESPONDED BY PROVIDING SATURDAY HIGHS IN THE UPPER 30S
AND LOW 40S. THERE ARE SUGGESTIONS FROM MULTIPLE SETS OF GUIDANCE
THAT THIS TEMPERATURE FORECAST FOR SATURDAY IS TOO HIGH AND NEEDS
TO BE REDUCED BY 4-5 DEGREES. WENT AHEAD WITH A ~2 DEGREE DECREASE
FROM THE SUPERBLEND SOLUTION FOR SATURDAY HIGHS TO ACCOUNT OF
THIS...BUT EVEN NOW THE OFFICIAL FORECAST CALLS FOR SATURDAY
TEMPERATURE READINGS IN THE UPPER 30S FOR MOST LOCATIONS AND GIVEN
THIS...DESPITE FORECAST PROXIMITY SOUNDINGS FROM THE OPERATIONAL
GFS AND EC SUGGESTING SNOWFALL WILL BE THE PRIMARY PRECIPITATION
TYPE DURING THE DAY SATURDAY...FIND IT HARD TO JUSTIFY AN ALL-SNOW
FORECAST WITH SURFACE TEMPERATURE READINGS SO HIGH. AS A
RESULT...OPTED TO GO WITH A RAIN AND SNOW MIX DURING THE DAY
SATURDAY...WITH ALL SNOW THEN EXPECTED SATURDAY NIGHT INTO SUNDAY
AS DIABATIC HEATING IS LOST AND A BOUNDARY-LAYER BAROCLINIC ZONE
CLEARS THE AREA. OBVIOUSLY THE TEMPERATURE FORECAST FOR SATURDAY
WILL NEED TO BE CLOSELY MONITORED AS ANY MORE OF A DECREASE IN
SATURDAYS TEMPERATURE FORECAST WOULD SUGGEST MORE SNOW THAN RAIN
DURING THE DAY SATURDAY...AND MORE IN THE WAY OF SNOW
ACCUMULATION.
OBVIOUSLY STORM-TOTAL SNOWFALL ACCUMULATION WILL BE HEAVILY
DEPENDENT UPON HOW MUCH SNOWFALL IS REALIZED DURING THE DAY
SATURDAY...AND GIVEN THE UNCERTAINTY WITH RESPECT TO PRECIPITATION
TYPE AND RESULTANT SNOW ACCUMULATION DURING THE DAY
SATURDAY...IT STILL REMAINS TOO EARLY TO GET SPECIFIC ON SNOW
AMOUNTS IN THE OFFICIAL FORECAST. THAT SAID...ONCE AGAIN TAKING
THE OPERATIONAL GFS AND EC AT FACE VALUE SUGGESTS ADVISORY-WORTHY
ACCUMULATION OF ~3 INCHES COULD BE REALIZED ACROSS PORTIONS OF THE
CWA SATURDAY NIGHT INTO EARLY SUNDAY MORNING ALONE...DESPITE WHAT
HAPPENS DURING THE DAY SATURDAY. IN ADDITION...GUIDANCE IS NOW
SUGGESTING THAT AN INCREASING PRESSURE GRADIENT POST-FROPA
SATURDAY NIGHT INTO SUNDAY WILL PROMOTE A STRONG WIND...SUSTAINED
AT AROUND 18KTS WITH HIGHER GUSTS. THIS WIND...WORKING IN CONCERT
WITH THE SNOWFALL...WOULD LIKELY CREATE AT LEAST PERIODIC
VISIBILITY RESTRICTION IN BLOWING SNOW. SO...GIVEN THE FACT THAT
WE NOW HAVE "LIKELY" POPS IN THE FORECAST FOR PORTIONS OF THE AREA
THIS WEEKEND...AND THE FACT THAT IT NOW APPEARS WE HAVE AN
OPPORTUNITY FOR BLOWING SNOW AND VISIBILITY RESTRICTION...FEEL IT
PRUDENT TO INTRODUCE A MENTION OF ACCUMULATING SNOWFALL AND
VISIBILITY RESTRICTION DUE TO BLOWING SNOW FOR THIS WEEKEND IN THE
HWO.
FINALLY...HIGHS TO START THE LONG-TERM FORECAST PERIOD ON THURSDAY
AND FRIDAY ARE STILL EXPECTED TO CLIMB INTO THE 40S...BUT WILL
FALL INTO THE 20S POST-FROPA STARTING EARLY NEXT WEEK. OVERNIGHT
LOWS IN THE 20S AND 30S ARE ALSO EXPECTED TO START THE LONG-TERM
FORECAST PERIOD...BUT THESE READINGS WILL LIKELY FALL INTO THE
SINGLE DIGITS AND TEENS EARLY NEXT WEEK AS WELL.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1130 PM CST TUE JAN 27 2015
QUIET WEATHER WITH VFR CONDITIONS CURRENTLY FORECAST FOR THIS TAF
PERIOD...WITH THE PRIMARY CONCERN LYING WITH WINDS. A WEAKER
SURFACE PATTERN CURRENTLY IN PLACE LOOKS TO KEEP SRLY WINDS ON THE
LIGHTER SIDE TONIGHT...BEFORE BECOMING MORE WRLY NEAR SUNRISE AS A
COLD FRONT APPROACHES FROM THE WEST. THIS FRONT STARTS WORKING
ITS WAY THROUGH THE AREA DURING THE MORNING HOURS. EXPECTING THE
FRONT AND ACCOMPANYING GUSTIER NW WINDS TO MAKE THEIR WAY THROUGH
THE TERMINAL AREAS DURING THE MID MORNING HOURS...WITH SPEEDS THEN
INCREASING INTO THE 20 TO 25 MPH RANGE WITH HIGHER GUSTS...WHICH
ARE EXPECTED TO CONTINUE THROUGH THE DURATION OF THIS TAF PERIOD.
&&
.FIRE WEATHER...
ISSUED AT 344 AM CST WED JAN 28 2015
GUSTY W/NW WINDS ARE EXPECTED TO DEVELOP ACROSS THE CWA DURING THE
DAYTIME HOURS TODAY...AND ABOVE AVERAGE TEMPERATURES ARE ONCE
AGAIN FORECAST. HIGH TEMPERATURES REACHING WELL INTO THE 60S TO
NEAR 70 DEGREES IN SOME LOCATIONS...COMBINED WITH DEWPOINTS
FORECAST TO FALL TO NEAR 30 DEGREES WILL RESULT IN NEAR CRITICAL
FIRE WEATHER CONDITIONS ACROSS PORTIONS OF THE CWA. THE BEST
CHANCE FOR RELATIVE HUMIDITY VALUES TO FALL INTO THE 20 TO 25 MPH
RANGE WITH THOSE GUSTY WINDS WILL LIE ACROSS AREAS GENERALLY
ALONG AND WEST OF A LEXINGTON NEB TO BELOIT KS LINE.
&&
.CLIMATE...
ISSUED AT 331 AM CST TUE JAN 27 2015
YET ANOTHER DAY WITH FORECAST HIGHS WELL ABOVE AVERAGE IS EXPECTED
TODAY. AVERAGE HIGHS FOR THIS TIME OF YEAR ARE MAINLY IN THE MID
30S...WITH HIGHS FORECAST TODAY TO REACH INTO THE 60S /NEAR 70
POSSIBLE ACROSS SRN LOCATIONS/. HERE IS THE RECORD HIGH
TEMPERATURE INFORMATION FOR TODAY...WITH GRAND ISLAND CURRENTLY
FORECAST TO BREAK THAT RECORD...BUT HASTINGS FORECAST TO FALL A
BIT SHORT.
GRAND ISLAND: RECORD IS 63 DEGREES IN 1986. FORECAST HIGH: 65
HASTINGS: RECORD IS 69 DEGREES IN 1931. FORECAST HIGH: 65
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...ADP
LONG TERM...BRYANT
AVIATION...ADP
FIRE WEATHER...ADP
CLIMATE...ADP
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
319 AM CST WED JAN 28 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM CST WED JAN 28 2015
TRICKY TEMPERATURE FORECAST TODAY...WHICH WILL BE LARGELY DEPENDENT
ON THE EXTENT OF CLOUD COVERAGE. VERY MILD 925 MB TEMPERATURES ABOVE
ZERO AND SOUTHERLY WINDS AT THE SURFACE WILL TAP INTO SOME CONTINUED
SEASONABLY WARM TEMPERATURES. THE QUESTION IS HOW MUCH CLOUD COVER
WILL IMPACT WARMING TODAY. THE MOST RECENT HRRR HAS A GOOD HANDLE ON
CLOUDS EARLY THIS MORNING...WHICH WILL SHIFT EASTWARD INTO THE
MIDDAY HOURS. THINK THE THE NORTHEASTERN HALF OF THE FORECAST
AREA...FROM EAST CENTRAL SD INTO SOUTHWEST MN AND THE IOWA GREAT
LAKES ARE WILL HOLD ONTO MOSTLY CLOUDY SKIES THE BULK OF THE DAY.
KEPT TEMPERATURES ON THE CONSERVATIVE SIDE OF GUIDANCE IN THIS AREA.
IF CLOUDS LOOK LESS ABUNDANT...COULD SEE READINGS WARM ABOVE
FORECAST HIGHS. ELSEWHERE...MOSTLY SUNNY TO PARTLY CLOUDY SKIES
THROUGH MID AFTERNOON WILL GIVE WAY TO CLOUDS WITH THE ANTICIPATED
FRONTAL PASSAGE LATE AFTERNOON. SOUTH CENTRAL SD INTO THE MISSOURI
VALLEY WILL HAVE THE BEST POTENTIAL TO WARM INTO THE LOW TO MID 50S.
WITH THE FRONT TRACKING THROUGH THE AREA MID AFTERNOON INTO THIS
EVENING...CLOUDS WILL ROLL BACK INTO THE REGION. NORTHWEST WINDS
EXPECTED TO BECOME QUITE WINDY BEHIND THE FRONT WITH 40 TO 50 KT
WINDS JUST OFF THE SURFACE. AT THE SURFACE...WINDS WILL LIKELY BE
NEAR ADVISORY LEVEL...ESPECIALLY WITH GUSTS AROUND 40 OR 45 MPH.
GIVEN THAT THE STRONGEST WINDS ARE EXPECTED IN THE EARLY MORNING
HOURS AND ARE MARGINAL FOR AN ADVISORY...WILL HOLD OFF ISSUING ANY
HEADLINES FOR NOW.
WITH LOW LEVEL STRATUS BLANKETING THE AREA OVERNIGHT...A FAST MOVING
SHORTWAVE DROPS ACROSS SOUTHWEST MINNESOTA LATE EVENING INTO THE
EARLY MORNING HOURS. NOT MUCH MOISTURE IN PLACE...AND WHILE THE LOW
STRATUS DOES THICKEN...THE CLOUD MASS REMAINS LARGELY OUTSIDE THE
SNOW GROWTH ZONE. COULD SEE A FEW SNOW ISOLATED SHOWERS DEVELOP
MAINLY IN OUR MN COUNTIES...WITH SOME PATCH DRIZZLE ALSO POSSIBLE.
SURFACE TEMPERATURES WILL BE NEAR OR JUST ABOVE FREEZING IN THIS
AREA.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 316 AM CST WED JAN 28 2015
THE SHORTWAVE EXITS THE AREA ON THURSDAY WITH SURFACE HIGH PRESSURE
BUILDING INTO THE REGION. IT WILL BE BREEZY WITH A TIGHT GRADIENT
ACROSS THE AREA AND GOOD MIXING IN A COLD AIR ADVECTION REGIME. IN
RESPONSE TO THE COLDER AIR FILTERING INTO THE REGION BEHIND THE
EXITING SHORTWAVE...HIGH TEMPERATURES WILL BE A GOOD 10 TO 15
DEGREES COOLER THAN TODAY...TOPPING OUT IN THE UPPER 20S FROM EAST
CENTRAL SD THROUGH SOUTHWESTERN MN...TO UPPER 30S THROUGH THE MO
RIVER CORRIDOR. WINDS WILL DIE OFF ON THURSDAY NIGHT...LEADING TO A
COLD NIGHT WITH LOWS IN THE LOWER/MID TEENS THROUGH THE EASTERN TWO
THIRDS OF THE CWA. TO THE WEST...IT WILL NOT BE QUITE AS COLD WITH
AN ENSUING SOUTHEASTERLY FLOW BEHIND THE EXITING HIGH
PRESSURE...WITH LOWS GENERALLY LOWER 20S. FRIDAY WILL SEE WARMING
WITH A STRENGTHENING SOUTHERLY FLOW ON THE BACKSIDE OF THE HIGH.
HIGH TEMPERATURES WILL RUN LOWER 30S NORTHEAST TO AS WARM AS THE MID
40S THROUGH SOUTH CENTRAL SD.
ON SATURDAY NORTHERN STREAM UPPER LEVEL ENERGY DROPS OUT OF WESTERN
CANADA AND SLIDES SOUTHWARD AS SOUTHERN STREAM ENERGY LIFTS TO THE
NORTH...CONVERGING OVER THE CENTRAL PLAINS. STILL SOME MODEL
DIFFERENCES ON HOW THIS SCENARIO EVOLVES...BUT DOES POTENTIALLY
BRING PRECIPITATION TO AT LEAST OUR SOUTHERN AND EASTERN CWA FOR
LATER ON SATURDAY AFTERNOON AND SATURDAY NIGHT. PRECIPITATION TYPE
LOOKS TO BE MAINLY IN THE FORM OF SNOW...WITH COOLING THERMAL
PROFILES AS LOW PRESSURE OVER THE JAMES BAY BEGINS TO DRIVE COLDER
AIR SOUTHWARD. AT THIS POINT SNOWFALL AMOUNTS LOOK TO BE IN THE
RANGE OF 2 TO 3 INCHES IN OUR SOUTHEAST...THOUGH WILL HAVE TO WATCH
THE TRACK OF THIS SYSTEM FOR GREATER SNOWFALL AMOUNTS IF IT TRENDS
FARTHER TO THE NORTH. IT STILL WONT BE UNREASONABLY COLD ON SATURDAY
WITH HIGHS MAINLY IN THE 30S...BUT BY SATURDAY NIGHT AND SUNDAY MUCH
COLDER AIR WILL HAVE SETTLED INTO THE REGION WITH HIGHS ON SUNDAY
MOSTLY IN THE TEENS. THE COLD AIR THEN LOOKS TO LINGER THROUGH NEXT
MONDAY...WITH SOME MODERATION POSSIBLE BY TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1041 PM CST TUE JAN 27 2015
MVFR CEILINGS JUST BRUSHING EASTERN EDGE OF THE FORECAST AREA AT THE
START OF THE TAF PERIOD...AND MAIN QUESTION IS WHETHER THOSE MVFR
CONDITIONS WILL EXPAND BACK INTO THE FORECAST AREA LATER TONIGHT AND
INTO WEDNESDAY MORNING. GIVEN STRONGER BOUNDARY LAYER WIND PROFILE
WHICH SHIFTS FROM SOUTHEAST AT THE SURFACE...TO SOUTH-SOUTHWEST IN
THE POTENTIAL STRATUS LAYER AND ABOVE...PREFER MODEL SOLUTIONS WHICH
KEEP THE AREA LARGELY VFR. AREA TO WATCH MAY BE KHON...AS SATELLITE
SHOWING EITHER STRATUS OR FOG HUGGING THE HIGHER ELEVATIONS WEST OF
THE JAMES RIVER VALLEY. HOWEVER PREFERRED MODELS WHICH KEEP THIS
JUST WEST OF KHON...AND THUS WILL CARRY VFR CONDITIONS AT ALL TAF
SITES THROUGH SUNSET WEDNESDAY.
COLD FRONT WILL PUSH ACROSS THE FORECAST AREA IN THE LATE MORNING
AND AFTERNOON. MVFR CEILINGS AND INCREASING NORTHWEST WINDS WILL
TRAIL SURFACE FRONTAL PASSAGE BY 3-6 HOURS...AS COLDER AIR MOVES IN
ALOFT AFTER 29/00Z. FREQUENT GUSTS OF 25-30+ KTS LIKELY WEDNESDAY
EVENING.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...
LONG TERM...JM
AVIATION...JH
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1036 PM CST TUE JAN 27 2015
UPDATED AVIATION PORTION FOR 06Z TAF 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 06Z TAF ISSUANCE
ISSUED AT 1035 PM CST TUE JAN 27 2015
LOW CLDS ACTUALLY DISSIPATED IN FAR ERN WI FOR A TIME THIS
EVENING. BUT WITH LOW-LEVEL FLOW SHIFTG BACK TO LIGHT SWLY...THEY
SHOULD EXPAND BACK ACRS THE AREA. EXPECT CIGS AND VSBYS TO
GRADUALLY COME DOWN OVERNIGHT...WITH IMPROVEMENT NOT OCCURRING
UNTIL MID-DAY OR AFTN TOMORROW.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......SKOWRONSKI
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
559 AM CST WED JAN 28 2015
.SHORT TERM...
345 AM CST
TODAY THROUGH FRIDAY NIGHT...
MAIN FORECAST CONCERNS IN THE SHORT TERM ARE CLOUD AND TEMP TRENDS
TODAY AND TONIGHT...AND TIMING...COVERAGE AND TYPE OF PRECIPITATION
TONIGHT AND THURSDAY AS LOW PRESSURE ORGANIZING OVER THE PLAINS
MOVES EAST.
RELATIVELY QUIET WEATHER THIS MORNING AS SURFACE HIGH PRESSURE
DRIFTS SLOWLY EAST OF THE AREA. SUBSIDENCE ASSOCIATED WITH HEIGHT
RISES ALOFT HAS LED TO A STRONG INVERSION AT AROUND 900 HPA HOWEVER
PER DVN 00Z SOUNDING...WHICH HAS TRAPPED LOW CLOUDS ACROSS THE
WESTERN PORTIONS OF THE FORECAST AREA OVERNIGHT. CLOUDS WERE SLOWLY
ERODING FROM THE SOUTHEAST THANKS TO 950-900 HPA WINDS GRADUALLY
VEERING TO THE SOUTHEAST AND SOUTH...AND LOWERING SUBSIDENCE
INVERSION. RAP GUIDANCE INDICATES SOUTH WINDS WILL INCREASE THIS
MORNING AND SHOULD CONTINUE TO LIFT THESE LOWER CLOUDS NORTH TOWARD
THE WI BORDER...THOUGH OVERALL NORTH CENTRAL ILLINOIS IS LIKELY TO
BE CLOUDIER THAN AREAS SOUTH AND EAST TODAY EVEN AS MID AND HIGH
CLOUDS BEGIN TO INCREASE AS WARM ADVECTION DEVELOPS ALOFT.
SURFACE LOW PRESSURE IS ALREADY TAKING SHAPE ACROSS THE PLAINS TO
OUR WEST THIS MORNING...IN RESPONSE TO A SHORT WAVE TROUGH EMERGING
FROM THE CENTRAL/NORTHERN ROCKIES. SURFACE PRESSURE FALLS AHEAD OF
THIS DEVELOPING LOW WILL LEAD TO INCREASING SOUTH-SOUTHEAST WINDS
NEAR 25 MPH THIS AFTERNOON. DESPITE SOUTHERLY FLOW...LOW LEVEL
PARCEL TRAJECTORIES WILL BE LARGELY FROM INDIANA/OHIO WHERE STRONG
COOLING HAS OCCURRED NEAR THE SURFACE HIGH THIS MORNING. COMBINED
WITH SOME MID/HIGH CLOUD COVER THIS MAY MAKE FOR HIGH TEMPERATURES
COMING LATER IN THE DAY WHEN LOW LEVEL WINDS VEER MORE SOUTHERLY AND
TAP MILDER AIR CURRENTLY ACROSS THE MISSOURI VALLEY. STRONG SOUTH
FLOW WILL CONTINUE TONIGHT AHEAD OF THE APPROACHING SURFACE
LOW...ALLOWING TEMPS TO STAY ABOVE FREEZING IN MOST AREAS.
GUIDANCE IN GOOD AGREEMENT IN DEVELOPING SOME LIGHT SPOTTY
PRECIPITATION ACROSS THE AREA LATE THIS EVENING...EXPANDING
OVERNIGHT ESPECIALLY ACROSS NORTHERN/NORTHEASTERN PARTS OF THE
FORECAST AREA. FORECAST SOUNDINGS INDICATE WARM LAYER TEMPS ALOFT IN
THE +5C RANGE OR BETTER...WITH SATURATION INITIALLY OCCURRING BELOW
700 HPA AND SUPPORTING LIGHT RAIN. WITH BREEZY SOUTH SURFACE WINDS
KEEPING TEMPS ABOVE MAINLY ABOVE FREEZING...PRECIPITATION TYPE IS
EXPECTED TO REMAIN LIQUID IN MOST LOCATIONS. LOW PROBABILITY DOES
EXIST FOR LIGHT FREEZING RAIN ESPECIALLY ACROSS FAR NORTH/NORTHEAST
IL...BUT AT THIS TIME FEEL IT IS FAIRLY UNLIKELY. THE SURFACE
LOW...AND A PAIR OF UN-PHASED SHORT WAVES....MOVE ACROSS THE CWA
DURING THE MORNING AND RESULT IN WINDS SHIFTING TO THE NORTHWEST.
THIS BRINGS COLDER AIR INTO THE REGION WITH COLLAPSING THICKNESS
FIELDS SUPPORTING LINGERING PRECIPITATION CHANGING OVER FROM LIGHT
RAIN TO A BRIEF RAIN/SLEET/SNOW MIX BEFORE ENDING FROM WEST-EAST.
MOST PRECIPITATION SHOULD END BY NOON WEST OF ABOUT THE IL/IN STATE
LINE...AND SHORTLY AFTER ACROSS NORTHWEST INDIANA. HOWEVER...GUSTY
NORTH-NORTHWEST WINDS AND COLDER AIR SPREADING ACROSS LAKE MICHIGAN
WILL LIKELY SUPPORT LAKE EFFECT SNOW SHOWERS ACROSS PARTS OF EASTERN
LAKE AND PORTER COUNTIES ESPECIALLY THURSDAY EVENING INTO EARLY
FRIDAY MORNING. THE REMAINDER OF THE AREA WILL JUST BE BLUSTERY AND
COLDER...WITH NORTH-NORTHWEST WINDS GUSTING ABOVE 30 MPH AT TIMES
THURSDAY BEFORE SLOWLY DIMINISHING THURSDAY NIGHT. AFTER MORNING
HIGHS IN THE MID-UPPER 30S OR EVEN NEAR 40 IN SOME SPOTS...THURSDAY
NIGHT LOOKS TO BE COLD WITH LOWS IN THE TEENS TO LOW 20S AND SINGLE
DIGIT WIND CHILLS.
SURFACE HIGH PRESSURE SPREADS INTO THE AREA AGAIN ON FRIDAY...WITH
TEMPERATURES STRUGGLING INTO THE MID-UPPER 20S BUT WITH MUCH LIGHTER
WINDS. LAKE SNOW SHOWERS WILL DIMINISH ACROSS NORTHWEST INDIANA AS
INVERSION HEIGHTS LOWER AND LOW LEVEL WINDS DIMINISH...WITH SUNSHINE
ELSEWHERE.
RATZER
&&
.LONG TERM...
345 AM CST
SATURDAY THROUGH TUESDAY...
THE MAIN FOCUS IN THE EXTENDED PERIOD IS ON A STORM SYSTEM WHICH
LOOKS TO LIFT THROUGH THE OHIO VALLEY LATE SATURDAY NIGHT THROUGH
SUNDAY. ECMWF/GFS ARE IN RELATIVELY GOOD AGREEMENT IN TAKING SURFACE
LOW TRACK ALONG THE OHIO RIVER...THOUGH GFS IS A LITTLE SLOWER AND
GEFS ENSEMBLE MEMBERS STILL SHOW QUITE A BIT OF SPREAD IN THEIR
SOLUTIONS AT THE SURFACE. GEM ALSO SLOWER AND A BIT FARTHER SOUTH
THAN THE OTHER GLOBAL MODELS. DEPENDING UPON HOW THIS SYSTEM
EVENTUALLY TRACKS...IT COULD BE A SNOW PRODUCER FOR ALL OR PART OF
THE CWA...AS IT TAPS GULF MOISTURE DEFORMATION BAND WOULD LIKELY
CROSS CENTRAL IL/IN. GLOBAL MODELS ALSO INDICATE A STRONG SURGE OF
ARCTIC AIR IN THE WAKE OF THIS SYSTEM...WITH SIGNIFICANTLY COLDER
WEATHER I.E. LOWS +/- SINGLE DIGITS AND HIGHS PERHAPS ONLY IN THE
TEENS BY MONDAY/TUESDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* GUSTY SOUTH-SOUTHEAST SURFACE WINDS DEVELOPING BY EARLY
AFTERNOON AND STRENGTHENING INTO EVENING.
* SCATTERED LIGHT RAIN SHOWERS LIKELY AND MVFR CIGS DEVELOPING
OVERNIGHT...AND THE POSSIBILITY OF A BRIEF MIX WITH SNOW AND IFR
VISIBILITY BEFORE ENDING THURSDAY MORNING.
* SOUTH-SOUTHWEST WINDS AT 2000 FT OF AT LEAST 50 KT THIS EVENING
INTO OVERNIGHT THAT MAY CREATE LOW-LEVEL WIND SHEAR.
* NORTHWEST WINDS GUSTING TO AROUND 30 KT DURING THE DAY THURSDAY.
//DISCUSSION...UPDATED 12Z...
CURRENT BATCH OF MVFR CIGS ACROSS NORTHWEST ILLINOIS EARLY THIS
MORNING IS BEING STEERED ON SOUTHERLY WINDS EARLY THIS
MORNING...WITH RFD LIKELY TO EXPERIENCE AT LEAST TEMPORARY 2000 FT
CIGS OR SO THROUGH MID-MORNING. WITH THE APPROACH OF LOW
PRESSURE...SOUTH-SOUTHEAST WINDS WILL INCREASE WITH GUSTS LIKELY
IN THE AFTERNOON AND PERSISTING...AND LIKELY STRENGTHENING...INTO
THE EVENING AS STRONG PRESSURE FALLS ENVELOP THE REGION. GIVEN THE
CURRENT AND FORECAST PLACEMENT OF THE LOW PRESSURE...THE WIND
DIRECTION SHOULD BE EAST OF SOUTH MUCH OF TODAY AND EARLY THIS
EVENING...BEFORE GRADUALLY VEERING AHEAD OF A FRONT LATE TONIGHT.
A CHANNEL OF STRONG SOUTHWEST WINDS ALOFT...AROUND 2000-3000
FT...ARE LIKELY TO BE 50 PLUS KNOTS TONIGHT AND COULD RESULT IN
SOME LOW-LEVEL WIND SHEAR...ALTHOUGH SURFACE WINDS WILL REMAIN
ALSO INCREASED IN SOMEWHAT MIXED CONDITIONS.
THE COLD FRONT WILL PASS IN THE PRE-DAWN HOURS THURSDAY. AHEAD OF
THIS FRONT SATURATION SHOULD SLOWLY OCCUR NEAR THE INVERSION
LEVEL...WHICH IS EXPECTED TO BE AROUND 2000-3000 FT SO CIGS OF
THAT HEIGHT SHOULD GRADUALLY DEVELOP AS TONIGHT PROGRESSES. IN
ADDITION...THERE WILL BE POTENTIAL FOR SCATTERED RAIN
SHOWERS...WITH ANY RAIN POSSIBLY CHANGING TO A RAIN AND SNOW MIX
AFTER SUNRISE THURSDAY. ANY MIX IS NOT LIKELY TO LAST LONG BEFORE
ENDING...SO ACCUMULATIONS SHOULD BE ONLY A TRACE.
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH IN WIND DIRECTION AND SPEED TODAY AND THIS
EVENING...INCLUDING THE WIND DIRECTION REMAINING SLIGHTLY EAST
OF SOUTH.
* MEDIUM IN PRECIPITATION OCCURRING AT THE AIRFIELD LATER TONIGHT
AND EARLY THURSDAY MORNING.
* HIGH IN MVFR CIGS LATE TONIGHT INTO THURSDAY MORNING. LOW IN ANY
IFR OCCURRING.
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...MAINLY VFR. NORTH-NORTHWEST WINDS.
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...CHANCE OF SNOW DURING THE NIGHT. SOUTHWEST WINDS.
MTF
&&
.MARINE...
158 AM CST
AN ACTIVE PERIOD WILL UNFOLD OVER LAKE MICHIGAN THROUGH THIS
FORECAST THANKS TO THE PROGRESSIVE NATURE IN THE WEATHER PATTERN.
HIGH PRESSURE EARLY THIS MORNING WILL EXIT THE PICTURE AND A QUICKLY
APPROACHING LOW PRESSURE FROM THE WEST WILL BRING INCREASING
SOUTHERLY WINDS LATER TODAY INTO THIS EVENING. DURING THE EVENING
THERE IS A PERIOD WHERE OCCASIONAL GALES SHOULD OCCUR ACROSS THE
SOUTHERN HALF AS SOME INSTABILITY WILL BE PRESENT WITH GALE FORCE
WINDS ONLY 1000-1500 FT OFF THE WATER SURFACE. THE LOW SHOULD BE
ELONGATED RIGHT DOWN THE AXIS OF THE LAKE AROUND 6 AM THURSDAY
BEFORE IT QUICKLY MOVES EAST. THIS WILL RESULT IN STOUT NORTHWEST
WINDS AND COLD ADVECTION ACROSS THE LAKE WITH WHAT LOOKS LIKE
DEFINITE GALES FOR AT LEAST THE OPEN WATER...INCLUDING 40 KTS
WITH 45 KTS EVEN POSSIBLE ESPECIALLY IN THE NORTH. THIS LIKELY
WILL BRING SOME FREEZING SPRAY THURSDAY NIGHT TO THE OPEN
WATER. AT THIS TIME FORECAST INGREDIENTS ARE A LITTLE SHY FOR
HEAVY FREEZING SPRAY SO NO WATCH FOR THAT ISSUED BUT WILL NEED TO
BE MONITORED.
HAVE OPTED TO GO WITH A GALE WATCH FOR BEHIND THE LOW PRESSURE AS
THAT TIME PERIOD WILL BE THE HIGHEST WINDS WITH THE SYSTEM. WILL
JUST MENTION OCCASIONAL GALES ON THE FRONT SIDE DURING THIS
EVENING ACROSS MAINLY THE SOUTH HALF. SMALL CRAFT ADVISORY
CONDITIONS WILL OBVIOUSLY EXIST A GOOD AMOUNT OF THIS TIME ON THE
ILLINOIS AND INDIANA NEAR SHORES. WITH A SHORT 4-6 HOUR RESPITE
CENTERED ON DAYBREAK THURSDAY AS THE LOW PASSES...HAVE OPTED TO NOT
EXTEND THE CURRENT SMALL CRAFT ADVISORY...BUT ONE WILL DEFINITELY
BE NEEDED FOR THURSDAY AFTERNOON AND NIGHT...AND FOR THE INDIANA
SHORE INTO FRIDAY. THE GALE WATCH DOES INCLUDE PARTS OF THE
INDIANA NEARSHORE THAT WILL FEEL THE GREATER FETCH OF ONSHORE
WINDS AND THUS COULD REALIZE GALES THURSDAY AFTERNOON AND EVENING.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...NOON WEDNESDAY TO 4 AM THURSDAY.
GALE WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ744-LMZ745-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...NOON
THURSDAY TO 3 AM FRIDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS DES MOINES IA
533 AM CST WED JAN 28 2015
.SHORT TERM /TODAY/...
ISSUED AT 355 AM CST WED JAN 28 2015
COMPLICATED FORECAST TODAY TO SAY THE LEAST. INTENSE LOW EAST OF
MAINE CONTINUES TO BE HOLDING BACK EASTWARD TRANSLATION OF THE UPPER
LEVEL RIDGE OVER THE MIDWEST TODAY...RESULTING IN LOW STRATUS CLOUDS
HOLDING ON OVER EASTERN IOWA YESTERDAY AFTERNOON. FAST FORWARD TO
CURRENT WITH LOW STRATUS AND LIGHT FOG EXPANDING WEST A BIT INTO
CENTRAL IOWA ALONG A WEAK FRONTAL BOUNDARY EXTENDING WEST TO EAST
OVER THE FORECAST AREA AT 08Z. MESOSCALE MODELS DOING A BETTER JOB
WITH CLOUDS THAN SYNOPTIC...HRRR CAPTURES THE EXPANSION AND
GENERALLY BEGINS TO MOVE THE DECK NORTHEAST DURING THE DAY AS THE
PLAINS LOW ENTERS IOWA THIS AFTERNOON. OVER THE NORTH...MOISTURE
WILL REMAIN FOR MUCH OF THE DAY SO CLOUDS AND MUCH COOLER
TEMPERATURES THIS AFTERNOON ARE LIKELY ACROSS THE NORTH. A WIDE
RANGE OF TEMPERATURES IS EXPECTED TODAY WITH HIGHS IN THE UPPER 30S
FROM MASON CITY TO WATERLOO TO THE MID 50S AT DES MOINES TO NEAR 60
OVER THE FAR SOUTH. WILL CONTINUE THE NEAR RECORD HIGH HEADLINE OVER
THE SOUTHWEST AS ONCE THE CLOUDS BACK OFF...TEMPERATURES SHOULD MOVE
UP RATHER QUICKLY LATER THIS MORNING AND EARLY AFTERNOON. BY MID TO
LATE AFTERNOON CLOUDS WILL BEGIN TO FILL IN AGAIN AS THE LOW BEGINS
TO INCREASE LIFT ACROSS THE REGION. BY LATE AFTERNOON PARTLY SUNNY
CONDITIONS TO CLOUDY SKIES WILL PREVAIL. WINDS WILL BE SOUTH
SOUTHEAST THIS AFTERNOON WITH THE STRONGER WINDS OVER SOUTHEAST
SECTIONS. DESPITE THE UNSEASONABLY WARM TEMPERATURES ALOFT...6C
NORTHEAST TO 14C SOUTHWEST BY MIDDAY COOLING TO 4C NORTHEAST TO 10C
SOUTH...AFTERNOON HIGHS WILL BE ADVECTION BASED RATHER THAN PURE
MIXING BASED. TOWARD SUNSET MOSTLY CLOUDY CONDITIONS ARE EXPECTED.
.LONG TERM /TONIGHT THROUGH TUESDAY/...
ISSUED AT 355 AM CST WED JAN 28 2015
A VERY FAST MOVING SHORTWAVE IS STILL ON TRACK TO IMPACT DMX CWA
THURSDAY MORNING. AT 06Z WED...WATER VAPOR IMAGERY EASILY PICKING UP
THIS MID TO UPPER LOW CROSSING OVER THE ROCKIES. THE MODELS CONTINUE
TO INITIALIZE WELL WITH PLACEMENT OF THIS MID TO UPPER WAVE. TIMING
HAS REMAINED CONSISTENT...WITH THE MODELS PLACING THIS LOW DIRECTLY
OVER CENTRAL IOWA AT 06Z THU. SOUNDINGS ONCE AGAIN SHOW A SIZABLE
DRY AIR POCKET FROM AROUND 850MB TO 600MB WHICH WILL PREVENT CLOUD
THICKNESS FROM EXCEEDING 5 KFT AND...SUBSEQUENTLY...KEEP THIS SYSTEM
FROM PRODUCING ANYTHING BEYOND LIGHT PRECIP. KMCW TO KEST GFS
SOUNDINGS SUPPORT MAINLY DZ/-RA...WITH A VERY NARROW WINDOW OF -IP
TO -SN POSSIBLE FROM AROUND 09Z TO 12Z. BY 12Z THU...THIS LOW WILL
BE OVER NORTHERN ILLINOIS AND STRONG CAA ALONG WITH VERY DRY AIR IN
THE MID TO UPPER LEVELS WILL BE BROUGHT INTO OUR CWA. THOUGH A FAIR
AMOUNT OF SUNSHINE IS EXPECTED...DAYTIME TEMPS TO ONLY WARM AROUND 3
TO 5 DEGREES FROM OVERNIGHT MINS DUE TO CAA.
THURSDAY`S WINDS REMAIN WORTH MENTIONING. MODELS SHOWING 25 KT TO
30 KT WINDS RIGHT OFF THE DECK...APPROACHING 45 KT TO THE TOP OF
THE MIXED LAYER. SFC PRESSURE GRADIENT OF 3MB/100KM TO SUPPORT
STRONG WINDS AT THE SFC. WITH LOW OVER GREAT LAKES...WINDS WILL BE
STRONGEST ACROSS OUR NORTHERN CWA. IN ALL...WIND ADVISORY
BEGINNING EARLY THU AM LOOKING MORE AND MORE LIKELY WITH THE NEXT
UPDATE PACKAGE.
WHILE FRIDAY SHOULD BE SUNNY AND QUIET...IT LOOKS LIKE QUITE A
DIFFERENT STORY IS SHAPING UP FOR THE WEEKEND...ESPECIALLY
SATURDAY NIGHT INTO SUNDAY MORNING. THE EURO AND THE GFS ARE
BEGINNING TO COME IN LINE BOTH TEMPORALLY AND SPATIALLY WITH
BRINGING OUR NEXT CHANCE FOR "IMPACTFUL" SNOW ACCUMULATION TO OUR
CWA. FORECAST SOUNDINGS BEGIN TO SATURATE FROM TOP-DOWN SATURDAY
AFTERNOON. SEE LITTLE TO NO JUSTIFIABLE REASON FOR PRECIP DURING
THE MORNING SATURDAY...SO HAVE LOWERED POPS ACCORDINGLY. SATURDAY
EVENING...SOUNDINGS BEGIN TO COMPLETELY SATURATE ACROSS THE CWA
FROM SW TO NE...BECOMING COMPLETELY SATURATED BETWEEN 00Z SUN AND
06Z SUN. BOTH GFS AND EURO HAVE A LLJ TRANSPORTING MOISTURE INTO
THIS SYSTEM FROM THE GULF OF MEXICO. THE EURO IS SLIGHTLY FURTHER
NORTH WITH THIS MOISTURE...WHICH IS HELPING YIELD A COMPARATIVELY
HIGHER QPF. HIGHEST SNOWFALL AMOUNTS WILL THUS BE IN OUR SOUTHERN
CWA. CROSS SECTIONS CLEARLY SHOW LIFT THROUGH THE DENDRITIC GROWTH
ZONE. WAY TOO EARLY FOR ANY HEADLINES AT THIS POINT...BUT WORTH
NOTING THAT MODELS MAY BE KEYING IN ON A SOLUTION...WHICH WOULD
INCREASE CONFIDENCE.
BEHIND THIS SYSTEM...MONDAY INTO THE MID-WEEK...IT IS A LOCK THAT
TEMPERATURES WILL BE SIGNIFICANTLY COOLER THAN THEY HAVE BEEN FOR
THE PAST TWO WEEKS. THE FORECAST CHALLENGE FOR NOW IS HOW FAR THE
BOTTOM WILL FALL OUT ON TEMPS. ENSEMBLE RUNS ARE SHOWING AROUND -1
TO -2 STD DEV ON 850MB TEMPS ACROSS OUR CWA. TONIGHT`S 00Z GFS WAS
MARKEDLY COLDER THAN PVS RUNS. THE GFS HAS 850MB TEMPS DOWN TO
-19C ACROSS THE NE PORTION OF OUR CWA...WHEREAS THE EURO HAS 850
MB TEMPS DOWN TO ONLY -10C. SINCE OBVIOUS LACK OF CONSISTENCY FROM
GFS...WILL LEAN TOWARDS MORE CONSISTENT...LESS EXTREME...EURO. IF
THIS 00Z WED GFS SOLN HOLDS IN SUBSEQUENT RUNS...MAX AND MIN TEMPS
WILL NEED AT LEAST 5 DEGREES LOPPED OFF.
&&
.AVIATION...28/12Z
ISSUED AT 533 AM CST WED JAN 28 2015
STRATUS DECK THE MAIN CHALLENGE EARLY TODAY WITH AREA OF LIFR AND
FOG DEVELOPING AHEAD OF BOUNDARY NOW OVER CENTRAL IOWA. LOW
PRESSURE IN CENTRAL SOUTH DAKOTA TO MOVE SOUTHEAST. HRRR MODEL AND
TRENDS SUGGEST THAT CIGS WILL IMPROVE OVER CENTRAL/SOUTH AFT 15Z
WHILE NORTHEAST/NORTH WILL REMAIN IN MVFR/IFR CONDITIONS FOR MOST
OF THE DAY. BR AND NOW FG HAS DEVELOPED OVER THE NORTH WITH KMCW
DOWN TO 3/4SM. HAVE BROUGHT IN 1/2SM FZFG FOR BRIEF PERIOD PRIOR
TO 14Z WITH LIMITED IMPROVEMENT TOWARD 18Z. AFTER THE PASSAGE OF
THE LOW TONIGHT...WINDS BECOME MORE NORTHWEST AND INCREASE
DRAMATICALLY AFT 06-08Z REMAINING STRONG THROUGH END OF PERIOD.
CIGS WILL LOWER AGAIN NORTH AFT 03Z WITH POTENTIAL FOR -DZ OVER
NORTH AFT 00Z. CIGS SLOWLY IMPROVE BUT REMAIN IFR/MVFR OVER MUCH
OF AREA AFT 03Z. /REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...REV
LONG TERM...KOTENBERG
AVIATION...REV
AREA FORECAST DISCUSSION
NWS DULUTH MN
654 AM CST WED JAN 28 2015
.UPDATE...
ISSUED AT 654 AM CST WED JAN 28 2015
ADDED SOME PATCHY FOG THIS MORNING AS SEVERAL LOCATIONS ARE
REPORTING. SHOULD SEE THE FOG LIFT BY 15Z. REST OF THE FORECAST ON
TRACK.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 353 AM CST WED JAN 28 2015
LOW PRESSURE WAS ORGANIZING IN THE DAKOTAS AT 08Z WITH A FRONTAL
BOUNDARY EXTENDING NORTHEASTWARD INTO SOUTHERN MANITOBA AND INTO NW
ONTARIO. IN THE WAA AHEAD OF THIS SYSTEM...SOME LIGHT SNOW WAS
FALLING OVER THE ARROWHEAD WITH LITTLE ACCUMULATION. NORTH OF THE
CANADIAN BORDER...SOME LIGHT FREEZING RAIN WAS OCCURRING RIGHT NEAR
THE FRONT FROM WINNIPEG TO NEAR DRYDEN. LATEST SHORT TERM HRRR AND
RAP KEEP THIS FREEZING RAIN NORTH OF THE BORDER. THE LIGHT SNOW OVER
THE ARROWHEAD IS EXPECTED TO SLOWLY END BY NOON. LITTLE ADDITIONAL
ACCUMULATION IS ANTICIPATED.
BY THIS AFTERNOON...THE SFC LOW MOVES EASTWARD WITH THE LOW CENTER
BEGINS TO REORGANIZE AND DRIFT INTO SOUTHWEST IOWA BY 00Z THURSDAY.
MEANWHILE...A MID LEVEL LONG WAVE TROF MOVES OVER THE WESTERN GREAT
LAKES. SOME MODEL DIFFERENCES BEGIN TO REVEL THEMSELVES WITH RESPECT
TO QPF PLACEMENT AND THE AMOUNT OF COLD AIR FORECAST TO DROP INTO
THE FORECAST AREA. THE GFS IS THE MOST ROBUST AND FURTHEST SOUTH
WHILE THE ECMWF HAS LIMITED QPF AND KEEPS IT NEAR THE CANADIAN
BORDER. HAVE USED A BLENDED APPROACH AND KEPT POPS TO THE NORTHERN
HALF OF THE FORECAST AREA BY LATE AFTERNOON. PRECIPITATION TYPE WILL
BE ALL SNOW. LATEST FORECAST SOUNDINGS ARE NOT SUPPORTING THE
MENTION OF FREEZING RAIN OR FREEZING DRIZZLE AND HAVE REMOVED.
TONIGHT...THE MID LEVEL LONG WAVE TROF MOVES EAST OF THE FORECAST
AREA BY 12Z THURSDAY. THIS PUSHES THE SFC LOW EAST OF THE AREA AS
WELL. BEHIND THIS SYSTEM...A TIGHTENING PRESSURE GRADIENT MOVES OVER
THE WESTERN GREAT LAKES AS HIGH PRESSURE BUILDS INTO THE WESTERN
DAKOTAS. MADE SOME MINOR CHANGES TO THE POPS AND THEIR TIMING ACROSS
THE AREA...WITH THE SNOW ENDING LATE TONIGHT OVER THE SOUTHWEST
PORTION OF THE FORECAST AREA TO THE TWIN PORTS LATE TONIGHT.
FORECAST SOUNDINGS INDICATE THAT THE PRECIPITATION TYPE WILL BE ALL
SNOW AND HAVE REMOVED THE MENTION FREEZING RAIN/FREEZING DRIZZLE AND
SLEET. SNOW AMOUNTS WILL BE LIGHT WITH THE HIGHEST AMOUNTS OF AROUND
ONE HALF INCH FOUND ALONG THE CANADIAN BORDER.
ON THURSDAY...ONLY MADE SOME MINOR CHANGES TO THE POPS AND WEATHER
AS MODELS ARE IN VERY GOOD AGREEMENT. WILL STILL HAVE GUSTY WINDS AS
THE TIGHT PRESSURE GRADIENT REMAINS UNTIL LATE AFTERNOON WHEN THE
AFOREMENTIONED HIGH PRESSURE MOVES INTO THE RED RIVER VALLEY. A NW
WIND OVER LAKE SUPERIOR AND CAA WILL LEAD TO SOME LAKE EFFECT SNOW
ALONG THE HIGHER TERRAIN OF THE SOUTH SHORE. SNOW AMOUNTS WILL BE
LIGHT HOWEVER AS DEEP COLD AIR IS LACKING UNTIL LATE AFTERNOON.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 353 AM CST WED JAN 28 2015
MUCH COLDER AIR ON THE WAY FOR THIS WEEKEND WITH A CHANCE FOR SNOW
FROM...YOU GUESSED IT...ANOTHER WEAK CLIPPER SYSTEM. THE LARGE SCALE
PATTERN WILL UNDERGO SOME CHANGES THROUGH THE LONG TERM THAT WILL
/AT LEAST TEMPORARILY/ PUT A STOP TO WHAT HAS BEEN A LONG PERIOD OF
WEAK /AND FRANKLY DISAPPOINTING FOR SNOW LOVERS/ CLIPPERS.
TEMPERATURES WILL DROP FROM WHAT HAS BEEN A VERY MILD PATTERN TO A
COLDER REGIME...ENDING THE LAST WEEK OF JANUARY WITH TEMPS SIMILAR
TO THE FIRST WEEK OF THE MONTH.
ON THE SYNOPTIC SCALE A SERIES OF STRONG ARCTIC AIR MASSES WILL DROP
DOWN INTO THE NORTHERN PLAINS AND UPPER MIDWEST. LATE THIS WEEK AN
AREA OF HIGH PRESSURE WILL MOVE OVER THE AREA THURSDAY NIGHT
FOLLOWED BY A WEAK CLIPPER ON FRIDAY/FRIDAY NIGHT. THEN LATE IN THE
WEEKEND A DEEP LONGWAVE TROUGH AT MID-LEVELS WILL DESCEND OVER THE
MIDWEST LEADING TO VERY COLD AIR ALOFT...850MB TEMPS APPROACHING THE
COLDEST 10 PERCENT OF CLIMATOLOGY IN THE MID -20S C /COMPARED TO 00Z
TODAY WHEN THEY WERE IN THE WARMEST 10 PERCENT OF CLIMO AT AROUND
0C/.
BEST CHANCE FOR SNOWFALL ACROSS THE REGION WILL BE LATE FRIDAY
AFTERNOON INTO FRIDAY NIGHT A CLIPPER MOVES ACROSS. GFS AND ECMWF IN
GOOD AGREEMENT ON TIMING...WITH ECMWF PESSIMISTIC ON INTENSITY AND
GFS A LITTLE STRONGER WITH A DEEPER MOISTURE PROFILE. GEM WAS SLOWER
AND NOT AS INTENSE OVERALL...BUT THIS WAS A PRETTY BIG CHANGE FROM
12Z GEM WHICH WAS FASTER AND MUCH MORE AGGRESSIVE ON PRECIP. AT THIS
POINT IT LOOKS LIKE A QUICK INCH OR TWO FOR NORTHERN MINNESOTA NORTH
OF HIGHWAY TWO. OTHERWISE NO SIGNIFICANT CHANCES FOR PRECIP IN THE
SEVEN DAY FOR MUCH OF THE REGION...WITH THE EXCEPTION OF LAKE EFFECT
SNOWFALL ALONG PORTIONS OF THE SOUTH SHORE OF LAKE SUPERIOR.
LAKE EFFECT SNOWFALL WILL BE PRESENT THROUGH MUCH OF THE LONG TERM
PERIOD. ON THURSDAY NIGHT CONDITIONS WILL BE GOOD FOR LAKE EFFECT
SNOWFALL ALONG THE HIGHER TERRAIN OF IRON/ASHLAND COUNTIES WITH
STEEP LOW LEVEL LAPSE RATES THROUGH 850MB AND GREAT NORTH/NORTHWEST
FLOW OVER THE LAKE. ICE COVERAGE ON THE SOUTH SHORE MAY LIMIT THE
INTENSITY OF LAKE EFFECT SNOWFALL...AND OPTED TO LEAVE NORTHERN
BAYFIELD COUNTY OUT OF HIGHER CHANCES FOR LAKE EFFECT SNOWFALL DUE
TO WHAT WOULD BE A VERY LIMITED FETCH LENGTH. LOW LEVEL MOISTURE
WILL ALSO BE A FACTOR AS NAM/GFS/ECMWF DEPICT A NEAR-SURFACE DRY
LAYER...SO IT MAY TAKE A WHILE TO SATURATE LOW LEVELS AND THUS LIMIT
SNOWFALL AMOUNTS. LAKE EFFECT WILL TAPER OFF AS HIGH PRESSURE MOVES
OVER LAKE SUPERIOR ON FRIDAY AFTERNOON...BUT RAMP BACK UP AGAIN ON
SATURDAY AND THROUGH ABOUT TUESDAY DUE TO THE VERY COLD AIRMASS THAT
WILL BE IN PLACE.
TEMPS WILL BE ON A DOWNWARD TREND...AND HAVE ADJUSTED SOME OF THE
USUAL COLD SPOTS A LITTLE COLDER THAN INITIAL GUIDANCE TO ACCOUNT
FOR THE ARCTIC HIGHS THAT WILL BE OVER NORTHEASTERN MINNESOTA IN THE
LONG TERM. HIGHS IN THE MID TEENS TO MID 20S ON SATURDAY...THEN THE
SINGLE DIGITS ON SUNDAY AND MONDAY BEFORE RECOVERING TO THE TEENS
TUESDAY. LOWS NEAR ZERO TO TEN OR MORE BELOW ZERO ON THURSDAY
NIGHT...MILD FRIDAY NIGHT DUE TO WEAK SOUTHERLY WINDS...THEN 0 TO
-15 SATURDAY NIGHT AND 10 TO 20 BELOW ZERO ON SUNDAY NIGHT. MONDAY
MORNING WILL BE THE COLDEST PERIOD IN THE LONG TERM WITH WIND CHILL
VALUES OF 25 TO 35 BELOW ZERO...AND COLD SPOTS IN THE TIP OF THE
ARROWHEAD REGION NEAR 40 BELOW ZERO.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 526 AM CST WED JAN 28 2015
GENERALLY IFR CONDITIONS THROUGH MOST OF THE TAF PERIOD AT ALL SITES
DUE TO LOW CEILINGS AND PATCHY FOG DEVELOPING. AS OF THIS MORNING
ALL TAF SITES EXCEPT FOR INL WERE ALREADY AT IFR CONDITIONS...WITH
INL CEILINGS EXPECTED TO WORSEN LATER THIS MORNING. THERE WILL BE
LITTLE IMPROVEMENT THROUGH THE DAY WITH SOME SITES POSSIBLY
DETERIORATING TO LIFR CEILINGS AND IFR VISIBILITY THIS AFTERNOON.
TONIGHT A COLD FRONT WILL MOVE THROUGH WHICH WILL IMPROVE
CONDITIONS...WITH CEILINGS IMPROVING TO MVFR LEVELS. WINDS WILL BE
LIGHT TODAY OUT OF THE SOUTH...BUT BEHIND THE COLD FRONT LATE
TONIGHT WINDS WILL RAPIDLY INCREASE TO BECOME 10 TO 15 KTS OUT OF
THE WEST WITH GUSTS APPROACHING/EXCEEDING 30 KTS AT TIMES. DID NOT
INCLUDE STRONG WINDS IN ALL TAFS SINCE TIMING WILL BE RIGHT AROUND
END OF THE TAF PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 31 24 24 -1 / 10 50 10 0
INL 32 16 16 -10 / 30 60 10 0
BRD 34 22 22 5 / 10 40 0 0
HYR 33 27 27 -2 / 10 50 20 0
ASX 34 27 27 2 / 10 50 20 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...GSF
SHORT TERM...GSF
LONG TERM...JJM
AVIATION...JJM
AREA FORECAST DISCUSSION
NWS DULUTH MN
526 AM CST WED JAN 28 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 353 AM CST WED JAN 28 2015
LOW PRESSURE WAS ORGANIZING IN THE DAKOTAS AT 08Z WITH A FRONTAL
BOUNDARY EXTENDING NORTHEASTWARD INTO SOUTHERN MANITOBA AND INTO NW
ONTARIO. IN THE WAA AHEAD OF THIS SYSTEM...SOME LIGHT SNOW WAS
FALLING OVER THE ARROWHEAD WITH LITTLE ACCUMULATION. NORTH OF THE
CANADIAN BORDER...SOME LIGHT FREEZING RAIN WAS OCCURRING RIGHT NEAR
THE FRONT FROM WINNIPEG TO NEAR DRYDEN. LATEST SHORT TERM HRRR AND
RAP KEEP THIS FREEZING RAIN NORTH OF THE BORDER. THE LIGHT SNOW OVER
THE ARROWHEAD IS EXPECTED TO SLOWLY END BY NOON. LITTLE ADDITIONAL
ACCUMULATION IS ANTICIPATED.
BY THIS AFTERNOON...THE SFC LOW MOVES EASTWARD WITH THE LOW CENTER
BEGINS TO REORGANIZE AND DRIFT INTO SOUTHWEST IOWA BY 00Z THURSDAY.
MEANWHILE...A MID LEVEL LONG WAVE TROF MOVES OVER THE WESTERN GREAT
LAKES. SOME MODEL DIFFERENCES BEGIN TO REVEL THEMSELVES WITH RESPECT
TO QPF PLACEMENT AND THE AMOUNT OF COLD AIR FORECAST TO DROP INTO
THE FORECAST AREA. THE GFS IS THE MOST ROBUST AND FURTHEST SOUTH
WHILE THE ECMWF HAS LIMITED QPF AND KEEPS IT NEAR THE CANADIAN
BORDER. HAVE USED A BLENDED APPROACH AND KEPT POPS TO THE NORTHERN
HALF OF THE FORECAST AREA BY LATE AFTERNOON. PRECIPITATION TYPE WILL
BE ALL SNOW. LATEST FORECAST SOUNDINGS ARE NOT SUPPORTING THE
MENTION OF FREEZING RAIN OR FREEZING DRIZZLE AND HAVE REMOVED.
TONIGHT...THE MID LEVEL LONG WAVE TROF MOVES EAST OF THE FORECAST
AREA BY 12Z THURSDAY. THIS PUSHES THE SFC LOW EAST OF THE AREA AS
WELL. BEHIND THIS SYSTEM...A TIGHTENING PRESSURE GRADIENT MOVES OVER
THE WESTERN GREAT LAKES AS HIGH PRESSURE BUILDS INTO THE WESTERN
DAKOTAS. MADE SOME MINOR CHANGES TO THE POPS AND THEIR TIMING ACROSS
THE AREA...WITH THE SNOW ENDING LATE TONIGHT OVER THE SOUTHWEST
PORTION OF THE FORECAST AREA TO THE TWIN PORTS LATE TONIGHT.
FORECAST SOUNDINGS INDICATE THAT THE PRECIPITATION TYPE WILL BE ALL
SNOW AND HAVE REMOVED THE MENTION FREEZING RAIN/FREEZING DRIZZLE AND
SLEET. SNOW AMOUNTS WILL BE LIGHT WITH THE HIGHEST AMOUNTS OF AROUND
ONE HALF INCH FOUND ALONG THE CANADIAN BORDER.
ON THURSDAY...ONLY MADE SOME MINOR CHANGES TO THE POPS AND WEATHER
AS MODELS ARE IN VERY GOOD AGREEMENT. WILL STILL HAVE GUSTY WINDS AS
THE TIGHT PRESSURE GRADIENT REMAINS UNTIL LATE AFTERNOON WHEN THE
AFOREMENTIONED HIGH PRESSURE MOVES INTO THE RED RIVER VALLEY. A NW
WIND OVER LAKE SUPERIOR AND CAA WILL LEAD TO SOME LAKE EFFECT SNOW
ALONG THE HIGHER TERRAIN OF THE SOUTH SHORE. SNOW AMOUNTS WILL BE
LIGHT HOWEVER AS DEEP COLD AIR IS LACKING UNTIL LATE AFTERNOON.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 353 AM CST WED JAN 28 2015
MUCH COLDER AIR ON THE WAY FOR THIS WEEKEND WITH A CHANCE FOR SNOW
FROM...YOU GUESSED IT...ANOTHER WEAK CLIPPER SYSTEM. THE LARGE SCALE
PATTERN WILL UNDERGO SOME CHANGES THROUGH THE LONG TERM THAT WILL
/AT LEAST TEMPORARILY/ PUT A STOP TO WHAT HAS BEEN A LONG PERIOD OF
WEAK /AND FRANKLY DISAPPOINTING FOR SNOW LOVERS/ CLIPPERS.
TEMPERATURES WILL DROP FROM WHAT HAS BEEN A VERY MILD PATTERN TO A
COLDER REGIME...ENDING THE LAST WEEK OF JANUARY WITH TEMPS SIMILAR
TO THE FIRST WEEK OF THE MONTH.
ON THE SYNOPTIC SCALE A SERIES OF STRONG ARCTIC AIR MASSES WILL DROP
DOWN INTO THE NORTHERN PLAINS AND UPPER MIDWEST. LATE THIS WEEK AN
AREA OF HIGH PRESSURE WILL MOVE OVER THE AREA THURSDAY NIGHT
FOLLOWED BY A WEAK CLIPPER ON FRIDAY/FRIDAY NIGHT. THEN LATE IN THE
WEEKEND A DEEP LONGWAVE TROUGH AT MID-LEVELS WILL DESCEND OVER THE
MIDWEST LEADING TO VERY COLD AIR ALOFT...850MB TEMPS APPROACHING THE
COLDEST 10 PERCENT OF CLIMATOLOGY IN THE MID -20S C /COMPARED TO 00Z
TODAY WHEN THEY WERE IN THE WARMEST 10 PERCENT OF CLIMO AT AROUND
0C/.
BEST CHANCE FOR SNOWFALL ACROSS THE REGION WILL BE LATE FRIDAY
AFTERNOON INTO FRIDAY NIGHT A CLIPPER MOVES ACROSS. GFS AND ECMWF IN
GOOD AGREEMENT ON TIMING...WITH ECMWF PESSIMISTIC ON INTENSITY AND
GFS A LITTLE STRONGER WITH A DEEPER MOISTURE PROFILE. GEM WAS SLOWER
AND NOT AS INTENSE OVERALL...BUT THIS WAS A PRETTY BIG CHANGE FROM
12Z GEM WHICH WAS FASTER AND MUCH MORE AGGRESSIVE ON PRECIP. AT THIS
POINT IT LOOKS LIKE A QUICK INCH OR TWO FOR NORTHERN MINNESOTA NORTH
OF HIGHWAY TWO. OTHERWISE NO SIGNIFICANT CHANCES FOR PRECIP IN THE
SEVEN DAY FOR MUCH OF THE REGION...WITH THE EXCEPTION OF LAKE EFFECT
SNOWFALL ALONG PORTIONS OF THE SOUTH SHORE OF LAKE SUPERIOR.
LAKE EFFECT SNOWFALL WILL BE PRESENT THROUGH MUCH OF THE LONG TERM
PERIOD. ON THURSDAY NIGHT CONDITIONS WILL BE GOOD FOR LAKE EFFECT
SNOWFALL ALONG THE HIGHER TERRAIN OF IRON/ASHLAND COUNTIES WITH
STEEP LOW LEVEL LAPSE RATES THROUGH 850MB AND GREAT NORTH/NORTHWEST
FLOW OVER THE LAKE. ICE COVERAGE ON THE SOUTH SHORE MAY LIMIT THE
INTENSITY OF LAKE EFFECT SNOWFALL...AND OPTED TO LEAVE NORTHERN
BAYFIELD COUNTY OUT OF HIGHER CHANCES FOR LAKE EFFECT SNOWFALL DUE
TO WHAT WOULD BE A VERY LIMITED FETCH LENGTH. LOW LEVEL MOISTURE
WILL ALSO BE A FACTOR AS NAM/GFS/ECMWF DEPICT A NEAR-SURFACE DRY
LAYER...SO IT MAY TAKE A WHILE TO SATURATE LOW LEVELS AND THUS LIMIT
SNOWFALL AMOUNTS. LAKE EFFECT WILL TAPER OFF AS HIGH PRESSURE MOVES
OVER LAKE SUPERIOR ON FRIDAY AFTERNOON...BUT RAMP BACK UP AGAIN ON
SATURDAY AND THROUGH ABOUT TUESDAY DUE TO THE VERY COLD AIRMASS THAT
WILL BE IN PLACE.
TEMPS WILL BE ON A DOWNWARD TREND...AND HAVE ADJUSTED SOME OF THE
USUAL COLD SPOTS A LITTLE COLDER THAN INITIAL GUIDANCE TO ACCOUNT
FOR THE ARCTIC HIGHS THAT WILL BE OVER NORTHEASTERN MINNESOTA IN THE
LONG TERM. HIGHS IN THE MID TEENS TO MID 20S ON SATURDAY...THEN THE
SINGLE DIGITS ON SUNDAY AND MONDAY BEFORE RECOVERING TO THE TEENS
TUESDAY. LOWS NEAR ZERO TO TEN OR MORE BELOW ZERO ON THURSDAY
NIGHT...MILD FRIDAY NIGHT DUE TO WEAK SOUTHERLY WINDS...THEN 0 TO
-15 SATURDAY NIGHT AND 10 TO 20 BELOW ZERO ON SUNDAY NIGHT. MONDAY
MORNING WILL BE THE COLDEST PERIOD IN THE LONG TERM WITH WIND CHILL
VALUES OF 25 TO 35 BELOW ZERO...AND COLD SPOTS IN THE TIP OF THE
ARROWHEAD REGION NEAR 40 BELOW ZERO.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 526 AM CST WED JAN 28 2015
GENERALLY IFR CONDITIONS THROUGH MOST OF THE TAF PERIOD AT ALL SITES
DUE TO LOW CEILINGS AND PATCHY FOG DEVELOPING. AS OF THIS MORNING
ALL TAF SITES EXCEPT FOR INL WERE ALREADY AT IFR CONDITIONS...WITH
INL CEILINGS EXPECTED TO WORSEN LATER THIS MORNING. THERE WILL BE
LITTLE IMPROVEMENT THROUGH THE DAY WITH SOME SITES POSSIBLY
DETERIORATING TO LIFR CEILINGS AND IFR VISIBILITY THIS AFTERNOON.
TONIGHT A COLD FRONT WILL MOVE THROUGH WHICH WILL IMPROVE
CONDITIONS...WITH CEILINGS IMPROVING TO MVFR LEVELS. WINDS WILL BE
LIGHT TODAY OUT OF THE SOUTH...BUT BEHIND THE COLD FRONT LATE
TONIGHT WINDS WILL RAPIDLY INCREASE TO BECOME 10 TO 15 KTS OUT OF
THE WEST WITH GUSTS APPROACHING/EXCEEDING 30 KTS AT TIMES. DID NOT
INCLUDE STRONG WINDS IN ALL TAFS SINCE TIMING WILL BE RIGHT AROUND
END OF THE TAF PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 31 24 24 -1 / 10 50 10 0
INL 32 16 16 -10 / 30 60 10 0
BRD 34 22 22 5 / 10 40 0 0
HYR 33 27 27 -2 / 10 50 20 0
ASX 34 27 27 2 / 10 50 20 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...GSF
LONG TERM...JJM
AVIATION...JJM
AREA FORECAST DISCUSSION
NWS GLASGOW MT
835 AM MST WED JAN 28 2015
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH FRIDAY...
LOW CLOUDS AND PATCHY DENSE FOG HAS MOVED INTO THE NORTHERN ZONES
THIS MORNING AND IS EXPECTED TO SPREAD INTO THE SOUTHERN ZONES
THIS AFTERNOON...SANS THE FOG. TEMPS LOOK TO BE TOO HIGH SO
LOWERED THEM. PRECIP IN THE NE ZONES LOOK LIGHT. FOG WILL PROBABLY
LINGER INTO THE AFTERNOON. DOT CAMERAS EAST OF SCOBEY SHOWING
DENSE IN PLACES. TFJ
PREVIOUS DISCUSSION...
A SPLIT TROUGH TEMPORARILY KNOCKED DOWN THE RIDGE LAST NIGHT. THE
SOUTHERN SHORT-WAVE FEATURE WILL SEND MOISTURE THROUGH SOUTHEAST
MONTANA AND WYOMING TODAY...WHILE THE NORTHERN WAVE SENDS MOISTURE
EAST ACROSS CENTRAL SASKATCHEWAN. ASSOCIATED WITH THIS NORTHERN
TROUGH WILL BE A COLD FRONT SENT SOUTH OVER NORTHEAST MONTANA
TODAY. THE NAM AND GFS FRONTAL TIMING ARE DIFFERENT INDICATING
SOME UNCERTAINTY. THE RAP HAS PICKED THE MIDDLE GROUND...SO EXPECT
THE COLD FRONT TO CROSS THE INTERNATIONAL BORDER AROUND LATE
MORNING. TEMPERATURES ALOFT WILL BE COOLER THAN WE HAVE
EXPERIENCED FOR A WHILE...SO HIGHS WILL TREND LOWER THAN TUESDAY.
A SURFACE TROUGH SETS UP TO OUR EAST WHICH WILL DEVELOP BRISK
NORTHWEST WINDS OVER THE AREA TODAY...IN THE 20KT RANGE. WITH
INCREASED MIXING OF STRONG WINDS ALOFT TOWARD THE SURFACE...ALSO
EXPECT GUSTS TO 30KT. BY AFTERNOON THE FRONT SHOULD BE WELL INTO
NORTHEAST MONTANA. LIMITED OVERRUNNING MOISTURE COULD PRODUCE SOME
LIGHT PRECIPITATION. BUFKIT SUGGESTS PRECIPITATION TYPE TO BE
FREEZING RAIN OR RAIN IN THE MORNING AND RAIN IN THE AFTERNOON.
SLIGHT CHANCE POPS WILL BE LIMITED TO THE EASTERN ZONES.
TONIGHT...THE COLD BOUNDARY ONCE AGAIN SETS UP NW TO SE ACROSS THE
CWA. THE OVERRUNNING MOISTURE WILL CREATE LOW STRATUS OVER THE
EASTERN ZONES...AND POSSIBLY A LITTLE MORE LIGHT INTERMITTENT
PRECIPITATION IN THE EVENING. INCREASING HIGH SURFACE PRESSURE
FROM THE NORTH WILL DIMINISH NW WIND SIGNIFICANTLY.
THURSDAY THROUGH FRIDAY...FLOW ALOFT CONTINUES FROM THE NORTHWEST
AS THE STATIONARY BOUNDARY WANDERS AROUND JUST NORTHEAST OF OUR
AREA. 850MB TEMPERATURES WILL REMAIN NEAR 0C WHICH WILL BE MUCH
COOLER THAN THE LAST SEVERAL DAYS. MODELS CONTINUE TO DIFFER WITH
EXPECTED SURFACE TEMPERATURES. BUT UNTIL THE STATIONARY FRONT
DROPS SOUTH AGAIN TEMPERATURES WILL CONTINUE ABOVE NORMAL BY
AROUND 15F-20F. SCT
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY...
PERSISTENT LONG WAVE UPPER LEVEL RIDGE HANGS OVER PACIFIC NORTHEAST
REGION THROUGHOUT EXTENDED FORECAST PERIOD. RIDGE AXIS SLOWLY
RETROGRADES WESTWARD AS UPPER LEVEL HUDSON BAY LOW DEEPENS LATER
IN THE WEEKEND. TEMPERATURES WILL SLOWLY COOL TO BELOW SEASONAL
NORMALS SUNDAY AND MONDAY. BY WEDNESDAY RIDGE REESTABLISHES ITS
INFLUENCE OVER THE AREA FOR A RETURN TO NEAR NORMAL TEMPERATURES.
SEVERAL SHORTWAVES SWEEP THROUGH THE NORTHWEST FLOW ALOFT FOR A
SLIGHT CHANCE OF SHOWERS...WITH BEST CHANCES SATURDAY AFTERNOON AND
EVENING. WEAK SURFACE PRESSURE GRADIENTS WILL RESULT IN RELATIVELY
LIGHT WINDS THROUGH PERIOD. BRITTON
&&
.AVIATION...
FLIGHT CATEGORY: MVFR.
CIGS AND VSBY: MVFR WITH IFR CEILINGS ARE EXPECTED TODAY AS LOW
CLOUDS ARE MOVING SOUTHEAST INTO THE AREA. PATCHY DENSE FOG HAS
BEEN OBSERVED ON THE RIDGE TOPS. VALLEY AIRPORTS SHOULD ESCAPE
MUCH OF THE FOG.
WIND: WINDS WILL INCREASE THROUGH THE DAY FROM THE NW. TFJ
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS GLASGOW MT
521 AM MST WED JAN 28 2015
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH FRIDAY...
A SPLIT TROUGH TEMPORARILY KNOCKED DOWN THE RIDGE LAST NIGHT. THE
SOUTHERN SHORT-WAVE FEATURE WILL SEND MOISTURE THROUGH SOUTHEAST
MONTANA AND WYOMING TODAY...WHILE THE NORTHERN WAVE SENDS MOISTURE
EAST ACROSS CENTRAL SASKATCHEWAN. ASSOCIATED WITH THIS NORTHERN
TROUGH WILL BE A COLD FRONT SENT SOUTH OVER NORTHEAST MONTANA
TODAY. THE NAM AND GFS FRONTAL TIMING ARE DIFFERENT INDICATING
SOME UNCERTAINTY. THE RAP HAS PICKED THE MIDDLE GROUND...SO EXPECT
THE COLD FRONT TO CROSS THE INTERNATIONAL BORDER AROUND LATE
MORNING. TEMPERATURES ALOFT WILL BE COOLER THAN WE HAVE
EXPERIENCED FOR A WHILE...SO HIGHS WILL TREND LOWER THAN TUESDAY.
A SURFACE TROUGH SETS UP TO OUR EAST WHICH WILL DEVELOP BRISK
NORTHWEST WINDS OVER THE AREA TODAY...IN THE 20KT RANGE. WITH
INCREASED MIXING OF STRONG WINDS ALOFT TOWARD THE SURFACE...ALSO
EXPECT GUSTS TO 30KT. BY AFTERNOON THE FRONT SHOULD BE WELL INTO
NORTHEAST MONTANA. LIMITED OVERRUNNING MOISTURE COULD PRODUCE SOME
LIGHT PRECIPITATION. BUFKIT SUGGESTS PRECIPITATION TYPE TO BE
FREEZING RAIN OR RAIN IN THE MORNING AND RAIN IN THE AFTERNOON.
SLIGHT CHANCE POPS WILL BE LIMITED TO THE EASTERN ZONES.
TONIGHT...THE COLD BOUNDARY ONCE AGAIN SETS UP NW TO SE ACROSS THE
CWA. THE OVERRUNNING MOISTURE WILL CREATE LOW STRATUS OVER THE
EASTERN ZONES...AND POSSIBLY A LITTLE MORE LIGHT INTERMITTENT
PRECIPITATION IN THE EVENING. INCREASING HIGH SURFACE PRESSURE
FROM THE NORTH WILL DIMINISH NW WIND SIGNIFICANTLY.
THURSDAY THROUGH FRIDAY...FLOW ALOFT CONTINUES FROM THE NORTHWEST
AS THE STATIONARY BOUNDARY WANDERS AROUND JUST NORTHEAST OF OUR
AREA. 850MB TEMPERATURES WILL REMAIN NEAR 0C WHICH WILL BE MUCH
COOLER THAN THE LAST SEVERAL DAYS. MODELS CONTINUE TO DIFFER WITH
EXPECTED SURFACE TEMPERATURES. BUT UNTIL THE STATIONARY FRONT
DROPS SOUTH AGAIN TEMPERATURES WILL CONTINUE ABOVE NORMAL BY
AROUND 15F-20F. SCT
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY...
PERSISTENT LONG WAVE UPPER LEVEL RIDGE HANGS OVER PACIFIC NORTHEAST
REGION THROUGHOUT EXTENDED FORECAST PERIOD. RIDGE AXIS SLOWLY
RETROGRADES WESTWARD AS UPPER LEVEL HUDSON BAY LOW DEEPENS LATER
IN THE WEEKEND. TEMPERATURES WILL SLOWLY COOL TO BELOW SEASONAL
NORMALS SUNDAY AND MONDAY. BY WEDNESDAY RIDGE REESTABLISHES ITS
INFLUENCE OVER THE AREA FOR A RETURN TO NEAR NORMAL TEMPERATURES.
SEVERAL SHORTWAVES SWEEP THROUGH THE NORTHWEST FLOW ALOFT FOR A
SLIGHT CHANCE OF SHOWERS...WITH BEST CHANCES SATURDAY AFTERNOON AND
EVENING. WEAK SURFACE PRESSURE GRADIENTS WILL RESULT IN RELATIVELY
LIGHT WINDS THROUGH PERIOD. BRITTON
&&
.AVIATION...
FLIGHT CATEGORY: VFR.
SYNOPSIS: AN UPPER-LEVEL RIDGE OF HIGH PRESSURE PERSISTS OVER THE
REGION TODAY AND WILL ALLOW FOR SOME HIGH CLOUDINESS.
CIGS AND VSBY: VFR CIGS AND VSBY WILL CONTINUE THROUGH PERIOD.
WIND: WINDS WILL INCREASE THROUGH THE DAY ON WEDNESDAY.
BRITTON
&&
.HYDROLOGY...
DUE TO THE RECENT WARM TEMPERATURES SOME OF THE CREEKS AND SMALL
STREAMS HAVE BEGUN TO RUN. MINOR FLOODING WAS REPORTED AT 7 MILE
CREEK NEAR GLENDIVE WHICH PROMPTED THE ISSUANCE OF A SMALL STREAM
FLOOD ADVISORY THROUGH EARLY MORNING.
TEMPERATURES ARE EXPECTED TO TREND LOWER TOWARDS NORMAL BY THE
WEEKEND WHICH WILL WILL BEGIN TO LIMIT ANY FURTHER FLOODING.
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS GLASGOW MT
307 AM MST WED JAN 28 2015
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH FRIDAY...
A SPLIT TROUGH TEMPORARILY KNOCKED DOWN THE RIDGE LAST NIGHT. THE
SOUTHERN SHORT-WAVE FEATURE WILL SEND MOISTURE THROUGH SOUTHEAST
MONTANA AND WYOMING TODAY...WHILE THE NORTHERN WAVE SENDS MOISTURE
EAST ACROSS CENTRAL SASKATCHEWAN. ASSOCIATED WITH THIS NORTHERN
TROUGH WILL BE A COLD FRONT SENT SOUTH OVER NORTHEAST MONTANA
TODAY. THE NAM AND GFS FRONTAL TIMING ARE DIFFERENT INDICATING
SOME UNCERTAINTY. THE RAP HAS PICKED THE MIDDLE GROUND...SO EXPECT
THE COLD FRONT TO CROSS THE INTERNATIONAL BORDER AROUND LATE
MORNING. TEMPERATURES ALOFT WILL BE COOLER THAN WE HAVE
EXPERIENCED FOR A WHILE...SO HIGHS WILL TREND LOWER THAN TUESDAY.
A SURFACE TROUGH SETS UP TO OUR EAST WHICH WILL DEVELOP BRISK
NORTHWEST WINDS OVER THE AREA TODAY...IN THE 20KT RANGE. WITH
INCREASED MIXING OF STRONG WINDS ALOFT TOWARD THE SURFACE...ALSO
EXPECT GUSTS TO 30KT. BY AFTERNOON THE FRONT SHOULD BE WELL INTO
NORTHEAST MONTANA. LIMITED OVERRUNNING MOISTURE COULD PRODUCE SOME
LIGHT PRECIPITATION. BUFKIT SUGGESTS PRECIPITATION TYPE TO BE
FREEZING RAIN OR RAIN IN THE MORNING AND RAIN IN THE AFTERNOON.
SLIGHT CHANCE POPS WILL BE LIMITED TO THE EASTERN ZONES.
TONIGHT...THE COLD BOUNDARY ONCE AGAIN SETS UP NW TO SE ACROSS THE
CWA. THE OVERRUNNING MOISTURE WILL CREATE LOW STRATUS OVER THE
EASTERN ZONES...AND POSSIBLY A LITTLE MORE LIGHT INTERMITTENT
PRECIPITATION IN THE EVENING. INCREASING HIGH SURFACE PRESSURE
FROM THE NORTH WILL DIMINISH NW WIND SIGNIFICANTLY.
THURSDAY THROUGH FRIDAY...FLOW ALOFT CONTINUES FROM THE NORTHWEST
AS THE STATIONARY BOUNDARY WANDERS AROUND JUST NORTHEAST OF OUR
AREA. 850MB TEMPERATURES WILL REMAIN NEAR 0C WHICH WILL BE MUCH
COOLER THAN THE LAST SEVERAL DAYS. MODELS CONTINUE TO DIFFER WITH
EXPECTED SURFACE TEMPERATURES. BUT UNTIL THE STATIONARY FRONT
DROPS SOUTH AGAIN TEMPERATURES WILL CONTINUE ABOVE NORMAL BY
AROUND 15F-20F. SCT
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY...
PERSISTENT LONG WAVE UPPER LEVEL RIDGE HANGS OVER PACIFIC NORTHEAST
REGION THROUGHOUT EXTENDED FORECAST PERIOD. RIDGE AXIS SLOWLY
RETROGRADES WESTWARD AS UPPER LEVEL HUDSON BAY LOW DEEPENS LATER
IN THE WEEKEND. TEMPERATURES WILL SLOWLY COOL TO BELOW SEASONAL
NORMALS SUNDAY AND MONDAY. BY WEDNESDAY RIDGE REESTABLISHES ITS
INFLUENCE OVER THE AREA FOR A RETURN TO NEAR NORMAL TEMPERATURES.
SEVERAL SHORTWAVES SWEEP THROUGH THE NORTHWEST FLOW ALOFT FOR A
SLIGHT CHANCE OF SHOWERS...WITH BEST CHANCES SATURDAY AFTERNOON AND
EVENING. WEAK SURFACE PRESSURE GRADIENTS WILL RESULT IN RELATIVELY
LIGHT WINDS THROUGH PERIOD. BRITTON
&&
.AVIATION...
FLIGHT CATEGORY: VFR.
SYNOPSIS: AN UPPER-LEVEL RIDGE OF HIGH PRESSURE PERSISTS OVER THE
REGION TODAY AND WILL ALLOW FOR A FEW HIGH CHINOOK ARCH CLOUDS.
THEN AN UPPER-LEVEL SHORT WAVE SWINGS ACROSS NORTHERN MONTANA
AFTER 00Z.
CIGS AND VSBY: VFR CIGS AND VSBY WILL CONTINUE THROUGH 18Z THEN A
CHANCE FOR MVFR CIGS OVER THE NORTHEASTERN 1/3RD FOR THE
FORECAST AREA.
WIND: LIGHT WIND WILL SHIFT TO THE NORTHWEST OVERNIGHT AND THEN
INCREASE THROUGH THE DAY ON WEDNESDAY.
PROTON
&&
.HYDROLOGY...
DUE TO THE RECENT WARM TEMPERATURES SOME OF THE CREEKS AND SMALL
STREAMS HAVE BEGUN TO RUN. MINOR FLOODING WAS REPORTED AT 7 MILE
CREEK NEAR GLENDIVE WHICH PROMPTED THE ISSUANCE OF A SMALL STREAM
FLOOD ADVISORY FOR THROUGH EARLY MORNING.
TEMPERATURES ARE EXPECTED TO TREND LOWER TOWARDS NORMAL BY THE
WEEKEND WHICH WILL WILL BEGIN TO LIMIT ANY FURTHER FLOODING.
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS HASTINGS NE
540 AM CST WED JAN 28 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 344 AM CST WED JAN 28 2015
BEEN ANOTHER QUIET NIGHT ACROSS THE AREA...THANKS TO AN UPPER
LEVEL SHORTWAVE RIDGE AXIS THAT HAS BEEN STEADILY MAKING ITS WAY
EAST THROUGH THE PLAINS...PUSHED BY AN UPPER LEVEL DISTURBANCE
MOVING INTO WRN PORTIONS OF WY. AT THE SURFACE...THE PATTERN OVER
THE CWA IS ONCE AGAIN ON THE WEAKER SIDE...WITH A TROUGH AXIS SET
UP OVER THE HIGH PLAINS...RESULTING IN LIGHT AND AT TIMES VARIABLE
WINDS. TEMPS EARLY THIS MORNING AT 3 AM RANGE ANYWHERE FROM THE
MID 20S IN THE NORTH TO MID 40S IN THE FAR SWRN CORNER OF THE CWA.
THE MAIN STORY THROUGH THE SHORT TERM PERIOD LIES WITH THAT UPPER
LEVEL DISTURBANCE PUSHING INTO WY THIS MORNING...AND THE
ACCOMPANYING FRONTAL BOUNDARY IT WILL PUSH THROUGH THE CWA. MODELS
ARE IN PRETTY GOOD AGREEMENT WITH THE TIMING OF THIS
DISTURBANCE...SHOWING IT MOVING INTO THE NEB PANHANDLE NEAR MIDDAY
TODAY...BY 00Z THIS EVENING THE TROUGH AXIS LOOKS TO BE EXTENDING
THROUGH THE HEART OF THE CWA...BEFORE PUSHING OFF TO THE MISSOURI
RIVER AREA BY MIDNIGHT TONIGHT. A WEAKER SECOND MID LEVEL
DISTURBANCE QUICK ON THE HEELS OF THE MAIN ONE IS FORECAST TO BE
WORKING INTO THE AREA AS WE GET INTO THE EARLY MORNING HOURS
THURSDAY. EVEN WITH THERE ACTUALLY BEING A SYSTEM TO TALK
ABOUT...MODELS /INCLUDING THE MORE SHORT TERM HIRES LIKE THE WRF/
OVERALL CONTINUE TO BE IN GOOD AGREEMENT SHOWING CONDITIONS
REMAINING DRY...JUST NOT A LOT OF MOISTURE TO WORK WITH. THAT
BEING SAID...SOME MODELS ARE HINTING AT THE POTENTIAL OF SOME VERY
LIGHT PRECIP FALLING THIS EVENING/OVERNIGHT...BUT KEEP THAT SIGNAL
JUST OUTSIDE THE N/NERN BORDERS OF THE CWA. WILL BE SOMETHING FOR
THE DAY SHIFT TO MONITOR WITH THE 12Z RUN OF MODELS THIS MORNING.
AT THE SFC...WINDS WILL REMAIN ON THE LIGHTER SIDE THIS
MORNING...BEFORE THE WIND SHIFT OF THE COLD FRONT ACCOMPANYING
THIS SYSTEM PASSES THROUGH THE CWA...WHICH MODELS SHOW PUSHING
ABOUT HALFWAY THROUGH THE CWA BY MID MORNING AND MAKING IT TO THE
ERN FRINGE OF THE CWA AROUND MIDDAY. THIS WILL USHER IN A PUSH OF
GUSTY W/NWRLY WINDS /15 TO 25 MPH IS FORECAST/...BUT THE MAIN PUSH
OF COLDER AIR IS LAGGING BEHIND. TEMPS ALOFT COOL A TOUCH DURING
THE DAY...BUT HIGHS ARE STILL FORECAST TO BE WELL ABOVE
AVERAGE...THANKS TO THE MILD AIR/DOWNSLOPING WINDS. NOT EXPECTED
TO BE AS WARM AS TUESDAY...BUT TRENDED HIGHS TOWARD THE MAV AND
RAP /WHICH DID PRETTY WELL TUESDAY/...WHICH PUTS THE MAJORITY OF
THE CWA AT LEAST INTO THE MID 60S /THE EXCEPTION AGAIN IS THE
E/NERN PORTIONS/...WITH HIGHS NEAR 70 FORECAST IN NC KS. IF TEMPS
PAN OUT AS FORECAST...IT WOULD SET A NEW RECORD HIGH TEMPS IN
GRAND ISLAND. BUT CONFIDENCE ISNT THE HIGHEST...AS THERE ARE
MODELS THAT SAY IT WILL FALL SHORT OF/MAYBE TIE THE RECORD OF 63
DEGREES. THE RECORD AT HASTINGS IS 69 DEGREES...AND THE RAP IS
BASICALLY THE ONLY ONE SHOWING THE POTENTIAL FOR TEMPS TO MAKE A
RUN AT THAT RECORD. FIRE WX CONCERNS ARISE AGAIN...SEE FIRE
WEATHER SECTION BELOW FOR ADDITIONAL INFORMATION.
THIS EVENING/TONIGHT...ONE MIGHT THINK THAT WINDS WE HAVE THIS
AFTERNOON WOULD TAPER OFF...BUT WITH THE MAIN PUSH OF COLD AIR
ADVECTION...BETTER PRESSURE RISES/TIGHTER PRESSURE GRADIENT...AND
STRONGER WINDS ALOFT TO TAP INTO...THATS NOT THE CASE. MADE SOME
ADJUSTMENTS TO WIND SPEEDS...WHICH WILL BE ON A SECOND INCREASE
THIS EVENING...AND BY MIDNIGHT TONIGHT SPEEDS IN THE 25 TO 30
MPH RANGE WILL BE POSSIBLE...MAINLY ACROSS OUR SC NEB COUNTIES.
LOOKS TO REMAIN BREEZY INTO THE EARLY MORNING HOURS THURSDAY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 344 AM CST WED JAN 28 2015
GUIDANCE SUGGESTS AN UPPER TROPOSPHERIC SHORT WAVE WILL BE NOTED
OVER THE MID-MISSISSIPPI VALLEY TO START THE LONG-TERM FORECAST
PERIOD AT 12Z THURSDAY...THUS HELPING PROVIDE NORTHWESTERLY UPPER
TROPOSPHERIC FLOW OVER OUR AREA. THIS NORTHWESTERLY FLOW IS
EXPECTED TO PERSIST OVER OUR AREA THURSDAY INTO THURSDAY NIGHT
BEFORE THE APPROACH OF AN UPPER TROPOSPHERIC LONGWAVE TROUGH AXIS
PROMOTES QUASI-ZONAL TO SOUTHWESTERLY UPPER TROPOSPHERIC FLOW
FRIDAY THROUGH SATURDAY. THIS UPPER TROPOSPHERIC TROUGH AXIS IS
EXPECTED TO CLEAR OUR AREA SATURDAY NIGHT...THUS ALLOWING FOR
NORTHWESTERLY UPPER TROPOSPHERIC FLOW OVER OUR AREA AS WE HEAD
INTO THE EARLY PART OF NEXT WEEK.
GUIDANCE SUGGESTS AN OVERALL LACK IN OMEGA WILL KEEP US DRY
THURSDAY...THURSDAY NIGHT AND THROUGH THE DAY FRIDAY...AND SUCH
HAS BEEN PRESENTED IN THE OFFICIAL FORECAST.
STARTING FRIDAY NIGHT AND CONTINUING INTO SATURDAY...SATURDAY
NIGHT AND PERHAPS EARLY SUNDAY...UPPER TROPOSPHERIC THERMAL
ADVECTION AHEAD OF THE APPROACHING TROUGH AXIS IS EXPECTED TO
PROMOTE ENOUGH OMEGA FOR PRECIPITATION PRODUCTION ACROSS MUCH OF
THE REGION...INCLUDING OUR CWA. THE OPERATIONAL GFS AND EC
CONTINUE TO COME INTO BETTER AGREEMENT BY SUGGESTING PRECIPITATION
WILL MOVE IN FROM SOUTHWEST TO NORTHEAST ACROSS MUCH OF OUR
AREA...AGAIN BEGINNING FRIDAY NIGHT...WITH WIDESPREAD
PRECIPITATION THEN CONTINUING ACROSS THE AREA SATURDAY AND
SATURDAY NIGHT BEFORE MOVING EAST...ALONG THE UPPER TROPOSPHERIC
TROUGH AXIS...AROUND OR SHORTLY AFTER SUNRISE SUNDAY. INTERESTING
TO NOTE THAT THE NAM...WHICH THROUGH 84 HOURS IS JUST NOW UP TO
12Z SATURDAY...APPEARS TO KEEP THE PRIMARY AXIS OF OMEGA WELL TO
OUR SOUTHEAST AND AS A RESULT...KEEPS US DRY THROUGH 12Z SATURDAY.
ALTHOUGH IT WILL BE VERY INTERESTING TO SEE HOW THE NAM UNFOLDS
THROUGH THE NEXT FEW RUNS...GIVEN THE AFOREMENTIONED DATA FROM
THE OPERATIONAL GFS AND EC...IT SEEMS PRUDENT TO PRESENT YET
ANOTHER INCREASE IN POPS FOR THIS WEEKEND AND 30-60% POPS ARE NOW
SHOWN IN THE OFFICIAL FORECAST...WITH THE HIGHEST POPS RELEGATED
TO OUR SOUTHEAST WHICH IS WHERE GUIDANCE SUGGESTS THE STRONGEST
OMEGA AND MOST EFFICIENT PRECIPITATION PRODUCTION WILL RESIDE
DURING THIS UPCOMING STORM SYSTEM.
ONCE PRECIPITATION COMES TO AN END ON SUNDAY...GUIDANCE SUGGESTS
DRY CONDITIONS SHOULD BE OBSERVED SUNDAY NIGHT THROUGH
TUESDAY...AND SUCH HAS BEEN PRESENTED IN THE OFFICIAL FORECAST.
ALTHOUGH IT APPEARS PRECIPITATION COULD START OUT AS RAIN FRIDAY
NIGHT...FORECAST PROXIMITY SOUNDINGS FROM ACROSS THE CWA...PER THE
OPERATIONAL GFS AND EC...SUGGEST THE LOWER TROPOSPHERE WILL BE
SUPPORTIVE FOR SNOWFALL AT THE SURFACE BY 12Z SATURDAY AND
CONTINUING INTO SUNDAY. THAT SAID...WITH A CONTINUED
SOUTH/SOUTHEASTERLY BOUNDARY- LAYER WIND FIELD EXPECTED THROUGH
THE DAY SATURDAY...THERE IS STILL AT LEAST AN OPPORTUNITY FOR SOME
TEMPERATURE RECOVERY NEAR THE SURFACE DURING THE DAY SATURDAY AND
SUPERBLEND RESPONDED BY PROVIDING SATURDAY HIGHS IN THE UPPER 30S
AND LOW 40S. THERE ARE SUGGESTIONS FROM MULTIPLE SETS OF GUIDANCE
THAT THIS TEMPERATURE FORECAST FOR SATURDAY IS TOO HIGH AND NEEDS
TO BE REDUCED BY 4-5 DEGREES. WENT AHEAD WITH A ~2 DEGREE DECREASE
FROM THE SUPERBLEND SOLUTION FOR SATURDAY HIGHS TO ACCOUNT OF
THIS...BUT EVEN NOW THE OFFICIAL FORECAST CALLS FOR SATURDAY
TEMPERATURE READINGS IN THE UPPER 30S FOR MOST LOCATIONS AND GIVEN
THIS...DESPITE FORECAST PROXIMITY SOUNDINGS FROM THE OPERATIONAL
GFS AND EC SUGGESTING SNOWFALL WILL BE THE PRIMARY PRECIPITATION
TYPE DURING THE DAY SATURDAY...FIND IT HARD TO JUSTIFY AN ALL-SNOW
FORECAST WITH SURFACE TEMPERATURE READINGS SO HIGH. AS A
RESULT...OPTED TO GO WITH A RAIN AND SNOW MIX DURING THE DAY
SATURDAY...WITH ALL SNOW THEN EXPECTED SATURDAY NIGHT INTO SUNDAY
AS DIABATIC HEATING IS LOST AND A BOUNDARY-LAYER BAROCLINIC ZONE
CLEARS THE AREA. OBVIOUSLY THE TEMPERATURE FORECAST FOR SATURDAY
WILL NEED TO BE CLOSELY MONITORED AS ANY MORE OF A DECREASE IN
SATURDAYS TEMPERATURE FORECAST WOULD SUGGEST MORE SNOW THAN RAIN
DURING THE DAY SATURDAY...AND MORE IN THE WAY OF SNOW
ACCUMULATION.
OBVIOUSLY STORM-TOTAL SNOWFALL ACCUMULATION WILL BE HEAVILY
DEPENDENT UPON HOW MUCH SNOWFALL IS REALIZED DURING THE DAY
SATURDAY...AND GIVEN THE UNCERTAINTY WITH RESPECT TO PRECIPITATION
TYPE AND RESULTANT SNOW ACCUMULATION DURING THE DAY
SATURDAY...IT STILL REMAINS TOO EARLY TO GET SPECIFIC ON SNOW
AMOUNTS IN THE OFFICIAL FORECAST. THAT SAID...ONCE AGAIN TAKING
THE OPERATIONAL GFS AND EC AT FACE VALUE SUGGESTS ADVISORY-WORTHY
ACCUMULATION OF ~3 INCHES COULD BE REALIZED ACROSS PORTIONS OF THE
CWA SATURDAY NIGHT INTO EARLY SUNDAY MORNING ALONE...DESPITE WHAT
HAPPENS DURING THE DAY SATURDAY. IN ADDITION...GUIDANCE IS NOW
SUGGESTING THAT AN INCREASING PRESSURE GRADIENT POST-FROPA
SATURDAY NIGHT INTO SUNDAY WILL PROMOTE A STRONG WIND...SUSTAINED
AT AROUND 18KTS WITH HIGHER GUSTS. THIS WIND...WORKING IN CONCERT
WITH THE SNOWFALL...WOULD LIKELY CREATE AT LEAST PERIODIC
VISIBILITY RESTRICTION IN BLOWING SNOW. SO...GIVEN THE FACT THAT
WE NOW HAVE "LIKELY" POPS IN THE FORECAST FOR PORTIONS OF THE AREA
THIS WEEKEND...AND THE FACT THAT IT NOW APPEARS WE HAVE AN
OPPORTUNITY FOR BLOWING SNOW AND VISIBILITY RESTRICTION...FEEL IT
PRUDENT TO INTRODUCE A MENTION OF ACCUMULATING SNOWFALL AND
VISIBILITY RESTRICTION DUE TO BLOWING SNOW FOR THIS WEEKEND IN THE
HWO.
FINALLY...HIGHS TO START THE LONG-TERM FORECAST PERIOD ON THURSDAY
AND FRIDAY ARE STILL EXPECTED TO CLIMB INTO THE 40S...BUT WILL
FALL INTO THE 20S POST-FROPA STARTING EARLY NEXT WEEK. OVERNIGHT
LOWS IN THE 20S AND 30S ARE ALSO EXPECTED TO START THE LONG-TERM
FORECAST PERIOD...BUT THESE READINGS WILL LIKELY FALL INTO THE
SINGLE DIGITS AND TEENS EARLY NEXT WEEK AS WELL.
&&
.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 535 AM CST WED JAN 28 2015
MAIN FORECAST CONCERN FOR THIS TAF PERIOD LIES WITH WINDS. WINDS
REMAIN ON THE LIGHT AND AT TIMES VARIABLE SIDE EARLY THIS
MORNING THANKS TO A WEAKER SURFACE PATTERN IN PLACE...AND AT LEAST
FOR A FEW MORE HOURS WILL REMAIN THAT WAY. DEBATED THROWING IN A
MENTION OF LLWS FOR A FEW HOURS...BUT MODELS KEEP THE STRONGER
WINDS ALOFT TO THE WEST OF THE TERMINAL AREAS...SO KEPT OUT OF
THIS TAF. THIS MORNING...A FRONTAL BOUNDARY SHIFTING EAST WILL
BRING MORE WESTERLY WINDS TO THE AREA...THEN BECOMING
NORTHWESTERLY THIS AFTERNOON AND CONTINUING THROUGH THE END OF THE
TAF PERIOD. SPEEDS WILL ALSO BE ON THE INCREASE...WITH SUSTAINED
SPEEDS OF 15 TO 25 MPH EXPECTED THIS AFTERNOON...AND 25 TO 30 MPH
WINDS WILL BE POSSIBLE THROUGH AT LEAST THE EVENING HOURS...BUT
WILL REMAIN GUSTY THROUGH THE END OF THE PERIOD. MODELS ALSO
SUGGEST THE POTENTIAL FOR SOME LOWER CEILINGS ACCOMPANYING THE
COLDER AIR PUSH TONIGHT...SO INSERTED MVFR CEILINGS AT BOTH
TERMINALS.
&&
.FIRE WEATHER...
ISSUED AT 344 AM CST WED JAN 28 2015
GUSTY W/NW WINDS ARE EXPECTED TO DEVELOP ACROSS THE CWA DURING THE
DAYTIME HOURS TODAY...AND ABOVE AVERAGE TEMPERATURES ARE ONCE
AGAIN FORECAST. HIGH TEMPERATURES REACHING WELL INTO THE 60S TO
NEAR 70 DEGREES IN SOME LOCATIONS...COMBINED WITH DEWPOINTS
FORECAST TO FALL TO NEAR 30 DEGREES WILL RESULT IN NEAR CRITICAL
FIRE WEATHER CONDITIONS ACROSS PORTIONS OF THE CWA. THE BEST
CHANCE FOR RELATIVE HUMIDITY VALUES TO FALL INTO THE 20 TO 25 MPH
RANGE WITH THOSE GUSTY WINDS WILL LIE ACROSS AREAS GENERALLY
ALONG AND WEST OF A LEXINGTON NEB TO BELOIT KS LINE.
&&
.CLIMATE...
ISSUED AT 331 AM CST TUE JAN 27 2015
YET ANOTHER DAY WITH FORECAST HIGHS WELL ABOVE AVERAGE IS EXPECTED
TODAY. AVERAGE HIGHS FOR THIS TIME OF YEAR ARE MAINLY IN THE MID
30S...WITH HIGHS FORECAST TODAY TO REACH INTO THE 60S /NEAR 70
POSSIBLE ACROSS SRN LOCATIONS/. HERE IS THE RECORD HIGH
TEMPERATURE INFORMATION FOR TODAY...WITH GRAND ISLAND CURRENTLY
FORECAST TO BREAK THAT RECORD...BUT HASTINGS FORECAST TO FALL A
BIT SHORT.
GRAND ISLAND: RECORD IS 63 DEGREES IN 1986. FORECAST HIGH: 65
HASTINGS: RECORD IS 69 DEGREES IN 1931. FORECAST HIGH: 65
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...ADP
LONG TERM...BRYANT
AVIATION...ADP
FIRE WEATHER...ADP
CLIMATE...ADP
AREA FORECAST DISCUSSION
NWS BISMARCK ND
630 AM CST WED JAN 28 2015
.UPDATE...
ISSUED AT 630 AM CST WED JAN 28 2015
NO UPDATES OTHER THAN TO UPDATE TEMPERATURES BASED ON LATEST 6 AM
OBSERVATIONS.
UPDATE
ISSUED AT 546 AM CST WED JAN 28 2015
BASED ON TRENDS VIA OBSERVATIONS AND SATELLITE IMAGERY...WILL LEAN
ON HRRR GUIDANCE (WHICH IS DOING VERY WELL) AND EXPAND FOG
WORDING WEST AND SOUTH AND WILL ALSO EXPAND THE DENSE FOG ADVISORY
FARTHER WEST. ALSO EXTENDED TILL 18Z FOR HEADLINE CUTOFF.
UPDATE
ISSUED AT 344 AM CST WED JAN 28 2015
WILL GO WITH A DENSE FOG ADVISORY EAST. OBSERVATIONS NOT GETTING
ANY BETTER AND AREA WEB CAMS SHOWING WORSE VISIBILITIES NOW.
UPDATED PRODUCTS OUT SOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 312 AM CST WED JAN 28 2015
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE COOLER
TEMPERATURES...BREEZY CONDITIONS...AND CHANCES FOR LIGHT SNOW
TODAY AND TONIGHT.
CURRENTLY...ZONAL FLOW ALOFT WITH THE UPPER LEVEL RIDGE FLATTENING
ACROSS THE GREAT PLAINS IN RESPONSE TO SOUTHERN AND NORTHERN
STREAM S/WV`S CROSSING THE ROCKIES. SURFACE LOW PRESSURE
ASSOCIATED WITH THE SOUTHERN STREAM WAVE MOVING SOUTHEAST ACROSS
SOUTHWEST NORTH DAKOTA INTO CENTRAL SOUTH DAKOTA.
SOUTH/SOUTHEASTERLY RETURN FLOW AHEAD OF THE LOW HAS MAINTAINED
LOW STRATUS AND/OR FOG ACROSS EASTERN NORTH DAKOTA SINCE YESTERDAY
EVENING. LARGE STRATUS FIELD WRAPS BACK WESTWARD ACROSS SOUTH
CENTRAL CANADA WITH THE SOUTHERN EDGE OF THE STRATUS ALONG TO
SLIGHTLY NORTH OF THE INTERNATIONAL BORDER. VISIBILITIES CONTINUE
TO FLUCTUATE ACROSS MY EAST...AND WILL HANDLE THE PATCHY DENSE FOG
WITH THE CURRENT SPECIAL WEATHER STATEMENT.
AS THE SURFACE LOW CONTINUES SOUTHEAST TODAY...SURFACE WINDS
BECOME MORE NORTHWESTERLY AND INCREASE THROUGH THE MORNING INTO
THE AFTERNOON BEHIND A STRONG SFC COLD FRONT. BUFKIT ANALYSIS
BRINGS 35 TO NEAR 40KTS WITHIN THE TOP OF THE MIXED LAYER TO MOST
SITES...SO WHILE BREEZY...SUB-ADVISORY MAGNITUDES. THUS NO
HEADLINES WITH THIS FORECAST ISSUANCE. STRATUS TO OUR NORTH SURGES
SOUTH ALONG WITH CAA WITH MOST OF REGION CLOUDED OVER BY EARLY TO
MID AFTERNOON. CLOUD COVER AND BREEZY CONDITIONS WILL THEN
CONTINUE INTO WEDNESDAY NIGHT. POST FRONTAL SNOW SHOWERS DEVELOP
LATER THIS MORNING NORTH THEN SOUTHWARD THIS AFTERNOON CONTINUING
TONIGHT. KEPT POPS AT SLIGHT CHANCE FOR NOW...BUT MAY NEED TO BE
INCREASED.
FOR TEMPERATURES...DESPITE CAA AND CLOUD COVER...THE INCREASED
MIXING WITH THE BREEZY NORTHWEST WIND WILL ACTUALLY KEEP
TEMPERATURES FROM BOTTOMING OUT TOO MUCH TODAY. DAYTIME HIGHS
WILL BE COOLER THAN TUESDAY...RANGING FROM THE LOW 30S NORTH TO
MID/UPPER 40S SOUTHWEST. SO ABOUT 5-15 DEGREES COOLER. CLOUD COVER
AND CONTINUED MIXING TONIGHT SHOULD ALSO KEEP LOWS FROM DROPPING
TOO MUCH.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 315 AM CST WED JAN 28 2015
CHANCES FOR SNOW SATURDAY AND COOLER TEMPERATURES THROUGH THE
WEEKEND AND INTO NEXT WEEK WILL HIGHLIGHT THE LONG TERM.
AN UPPER LEVEL TROUGH MOVING SOUTHEAST FROM ALBERTA LATE FRIDAY INTO
EARLY SATURDAY MORNING WILL BRING A CHANCE OF SNOW THROUGH
SATURDAY NIGHT...ALONG WITH COLDER TEMPERATURES. THERE IS GOOD
AGREEMENT BETWEEN THE GFS/ECMWF IN THE OVERALL TIMING/LOCATION OF
THE UPPER LEVEL TROUGH. THE GLOBAL GEM IS AN OUTLIER AND WILL USE
A GFS/EC SOLUTION. THIS BRINGS THE BEST CHANCES OF LIGHT SNOW
ACCUMULATIONS MAINLY ALONG AND WEST OF THE HIGHWAY 83 CORRIDOR.
SNOW GROWTH ZONE BECOMES RATHER DEEP BY 00 UTC SUNDAY BUT OMEGA
WITHIN THE ZONE IS LIMITED. BUT WITH SNOW RATIOS INCREASING AS THE
COLD AIR FILTERS IN...THINK ONE OR TWO INCH ACCUMULATIONS ARE
POSSIBLE SATURDAY THROUGH SATURDAY NIGHT OVER THE WESTERN HALF OF
NORTH DAKOTA. A NORTHEAST SURFACE FLOW OF 10 TO 20 MPH COULD YIELD
SOME REDUCED VISIBILITIES IN FALLING SNOW...BUT SIGNIFICANT
BLOWING AND DRIFTING IS NOT EXPECTED AT THIS TIME. THE REMAINDER
OF THE FORECAST PERIOD BRINGS BELOW AVERAGE TEMPERATURES AND ONLY
MINIMAL PRECIPITATION CHANCES AHEAD OF EACH REINFORCING SHOT OF
COLD AIR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 630 AM CST WED JAN 28 2015
WIDESPREAD VLIFR CIGS WILL IMPACT ALL TERMINALS BY EARLY TODAY AS
LOW STRATUS AND FOG EXPAND SOUTH AND WEST ACROSS NORTH DAKOTA. LOW
STRATUS WILL THEN HOLD ON THROUGH WEDNESDAY NIGHT BUT WILL LIFT TO
LIFR/IFR MOST AREAS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR NDZ002>005-010>013-
021>023-025-036-037.
&&
$$
UPDATE...TWH
SHORT TERM...NH
LONG TERM...TWH
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
546 AM CST WED JAN 28 2015
.UPDATE...
ISSUED AT 546 AM CST WED JAN 28 2015
BASED ON TRENDS VIA OBSERVATIONS AND SATELLITE IMAGERY...WILL LEAN
ON HRRR GUIDANCE (WHICH IS DOING VERY WELL) AND EXPAND FOG
WORDING WEST AND SOUTH AND WILL ALSO EXPAND THE DENSE FOG ADVISORY
FARTHER WEST. ALSO EXTENDED TILL 18Z FOR HEADLINE CUTOFF.
UPDATE
ISSUED AT 344 AM CST WED JAN 28 2015
WILL GO WITH A DENSE FOG ADVISORY EAST. OBSERVATIONS NOT GETTING
ANY BETTER AND AREA WEB CAMS SHOWING WORSE VISIBILITIES NOW.
UPDATED PRODUCTS OUT SOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 312 AM CST WED JAN 28 2015
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE COOLER
TEMPERATURES...BREEZY CONDITIONS...AND CHANCES FOR LIGHT SNOW
TODAY AND TONIGHT.
CURRENTLY...ZONAL FLOW ALOFT WITH THE UPPER LEVEL RIDGE FLATTENING
ACROSS THE GREAT PLAINS IN RESPONSE TO SOUTHERN AND NORTHERN
STREAM S/WV`S CROSSING THE ROCKIES. SURFACE LOW PRESSURE
ASSOCIATED WITH THE SOUTHERN STREAM WAVE MOVING SOUTHEAST ACROSS
SOUTHWEST NORTH DAKOTA INTO CENTRAL SOUTH DAKOTA.
SOUTH/SOUTHEASTERLY RETURN FLOW AHEAD OF THE LOW HAS MAINTAINED
LOW STRATUS AND/OR FOG ACROSS EASTERN NORTH DAKOTA SINCE YESTERDAY
EVENING. LARGE STRATUS FIELD WRAPS BACK WESTWARD ACROSS SOUTH
CENTRAL CANADA WITH THE SOUTHERN EDGE OF THE STRATUS ALONG TO
SLIGHTLY NORTH OF THE INTERNATIONAL BORDER. VISIBILITIES CONTINUE
TO FLUCTUATE ACROSS MY EAST...AND WILL HANDLE THE PATCHY DENSE FOG
WITH THE CURRENT SPECIAL WEATHER STATEMENT.
AS THE SURFACE LOW CONTINUES SOUTHEAST TODAY...SURFACE WINDS
BECOME MORE NORTHWESTERLY AND INCREASE THROUGH THE MORNING INTO
THE AFTERNOON BEHIND A STRONG SFC COLD FRONT. BUFKIT ANALYSIS
BRINGS 35 TO NEAR 40KTS WITHIN THE TOP OF THE MIXED LAYER TO MOST
SITES...SO WHILE BREEZY...SUB-ADVISORY MAGNITUDES. THUS NO
HEADLINES WITH THIS FORECAST ISSUANCE. STRATUS TO OUR NORTH SURGES
SOUTH ALONG WITH CAA WITH MOST OF REGION CLOUDED OVER BY EARLY TO
MID AFTERNOON. CLOUD COVER AND BREEZY CONDITIONS WILL THEN
CONTINUE INTO WEDNESDAY NIGHT. POST FRONTAL SNOW SHOWERS DEVELOP
LATER THIS MORNING NORTH THEN SOUTHWARD THIS AFTERNOON CONTINUING
TONIGHT. KEPT POPS AT SLIGHT CHANCE FOR NOW...BUT MAY NEED TO BE
INCREASED.
FOR TEMPERATURES...DESPITE CAA AND CLOUD COVER...THE INCREASED
MIXING WITH THE BREEZY NORTHWEST WIND WILL ACTUALLY KEEP
TEMPERATURES FROM BOTTOMING OUT TOO MUCH TODAY. DAYTIME HIGHS
WILL BE COOLER THAN TUESDAY...RANGING FROM THE LOW 30S NORTH TO
MID/UPPER 40S SOUTHWEST. SO ABOUT 5-15 DEGREES COOLER. CLOUD COVER
AND CONTINUED MIXING TONIGHT SHOULD ALSO KEEP LOWS FROM DROPPING
TOO MUCH.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 315 AM CST WED JAN 28 2015
CHANCES FOR SNOW SATURDAY AND COOLER TEMPERATURES THROUGH THE
WEEKEND AND INTO NEXT WEEK WILL HIGHLIGHT THE LONG TERM.
AN UPPER LEVEL TROUGH MOVING SOUTHEAST FROM ALBERTA LATE FRIDAY INTO
EARLY SATURDAY MORNING WILL BRING A CHANCE OF SNOW THROUGH
SATURDAY NIGHT...ALONG WITH COLDER TEMPERATURES. THERE IS GOOD
AGREEMENT BETWEEN THE GFS/ECMWF IN THE OVERALL TIMING/LOCATION OF
THE UPPER LEVEL TROUGH. THE GLOBAL GEM IS AN OUTLIER AND WILL USE
A GFS/EC SOLUTION. THIS BRINGS THE BEST CHANCES OF LIGHT SNOW
ACCUMULATIONS MAINLY ALONG AND WEST OF THE HIGHWAY 83 CORRIDOR.
SNOW GROWTH ZONE BECOMES RATHER DEEP BY 00 UTC SUNDAY BUT OMEGA
WITHIN THE ZONE IS LIMITED. BUT WITH SNOW RATIOS INCREASING AS THE
COLD AIR FILTERS IN...THINK ONE OR TWO INCH ACCUMULATIONS ARE
POSSIBLE SATURDAY THROUGH SATURDAY NIGHT OVER THE WESTERN HALF OF
NORTH DAKOTA. A NORTHEAST SURFACE FLOW OF 10 TO 20 MPH COULD YIELD
SOME REDUCED VISIBILITIES IN FALLING SNOW...BUT SIGNIFICANT
BLOWING AND DRIFTING IS NOT EXPECTED AT THIS TIME. THE REMAINDER
OF THE FORECAST PERIOD BRINGS BELOW AVERAGE TEMPERATURES AND ONLY
MINIMAL PRECIPITATION CHANCES AHEAD OF EACH REINFORCING SHOT OF
COLD AIR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 546 AM CST WED JAN 28 2015
WIDESPREAD VLIFR CIGS WILL IMPACT ALL TERMINALS BY EARLY TODAY AS
LOW STRATUS AND FOG EXPAND SOUTH AND WEST ACROSS NORTH DAKOTA. LOW
STRATUS WILL THEN HOLD ON THROUGH WEDNESDAY NIGHT BUT WILL LIFT TO
LIFR/IFR MOST AREAS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR NDZ002>005-010>013-
021>023-025-036-037.
&&
$$
UPDATE...NH
SHORT TERM...NH
LONG TERM...TWH
AVIATION...NH
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
550 AM CST WED JAN 28 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM CST WED JAN 28 2015
TRICKY TEMPERATURE FORECAST TODAY...WHICH WILL BE LARGELY DEPENDENT
ON THE EXTENT OF CLOUD COVERAGE. VERY MILD 925 MB TEMPERATURES ABOVE
ZERO AND SOUTHERLY WINDS AT THE SURFACE WILL TAP INTO SOME CONTINUED
SEASONABLY WARM TEMPERATURES. THE QUESTION IS HOW MUCH CLOUD COVER
WILL IMPACT WARMING TODAY. THE MOST RECENT HRRR HAS A GOOD HANDLE ON
CLOUDS EARLY THIS MORNING...WHICH WILL SHIFT EASTWARD INTO THE
MIDDAY HOURS. THINK THE THE NORTHEASTERN HALF OF THE FORECAST
AREA...FROM EAST CENTRAL SD INTO SOUTHWEST MN AND THE IOWA GREAT
LAKES ARE WILL HOLD ONTO MOSTLY CLOUDY SKIES THE BULK OF THE DAY.
KEPT TEMPERATURES ON THE CONSERVATIVE SIDE OF GUIDANCE IN THIS AREA.
IF CLOUDS LOOK LESS ABUNDANT...COULD SEE READINGS WARM ABOVE
FORECAST HIGHS. ELSEWHERE...MOSTLY SUNNY TO PARTLY CLOUDY SKIES
THROUGH MID AFTERNOON WILL GIVE WAY TO CLOUDS WITH THE ANTICIPATED
FRONTAL PASSAGE LATE AFTERNOON. SOUTH CENTRAL SD INTO THE MISSOURI
VALLEY WILL HAVE THE BEST POTENTIAL TO WARM INTO THE LOW TO MID 50S.
WITH THE FRONT TRACKING THROUGH THE AREA MID AFTERNOON INTO THIS
EVENING...CLOUDS WILL ROLL BACK INTO THE REGION. NORTHWEST WINDS
EXPECTED TO BECOME QUITE WINDY BEHIND THE FRONT WITH 40 TO 50 KT
WINDS JUST OFF THE SURFACE. AT THE SURFACE...WINDS WILL LIKELY BE
NEAR ADVISORY LEVEL...ESPECIALLY WITH GUSTS AROUND 40 OR 45 MPH.
GIVEN THAT THE STRONGEST WINDS ARE EXPECTED IN THE EARLY MORNING
HOURS AND ARE MARGINAL FOR AN ADVISORY...WILL HOLD OFF ISSUING ANY
HEADLINES FOR NOW.
WITH LOW LEVEL STRATUS BLANKETING THE AREA OVERNIGHT...A FAST MOVING
SHORTWAVE DROPS ACROSS SOUTHWEST MINNESOTA LATE EVENING INTO THE
EARLY MORNING HOURS. NOT MUCH MOISTURE IN PLACE...AND WHILE THE LOW
STRATUS DOES THICKEN...THE CLOUD MASS REMAINS LARGELY OUTSIDE THE
SNOW GROWTH ZONE. COULD SEE A FEW SNOW ISOLATED SHOWERS DEVELOP
MAINLY IN OUR MN COUNTIES...WITH SOME PATCH DRIZZLE ALSO POSSIBLE.
SURFACE TEMPERATURES WILL BE NEAR OR JUST ABOVE FREEZING IN THIS
AREA.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 316 AM CST WED JAN 28 2015
THE SHORTWAVE EXITS THE AREA ON THURSDAY WITH SURFACE HIGH PRESSURE
BUILDING INTO THE REGION. IT WILL BE BREEZY WITH A TIGHT GRADIENT
ACROSS THE AREA AND GOOD MIXING IN A COLD AIR ADVECTION REGIME. IN
RESPONSE TO THE COLDER AIR FILTERING INTO THE REGION BEHIND THE
EXITING SHORTWAVE...HIGH TEMPERATURES WILL BE A GOOD 10 TO 15
DEGREES COOLER THAN TODAY...TOPPING OUT IN THE UPPER 20S FROM EAST
CENTRAL SD THROUGH SOUTHWESTERN MN...TO UPPER 30S THROUGH THE MO
RIVER CORRIDOR. WINDS WILL DIE OFF ON THURSDAY NIGHT...LEADING TO A
COLD NIGHT WITH LOWS IN THE LOWER/MID TEENS THROUGH THE EASTERN TWO
THIRDS OF THE CWA. TO THE WEST...IT WILL NOT BE QUITE AS COLD WITH
AN ENSUING SOUTHEASTERLY FLOW BEHIND THE EXITING HIGH
PRESSURE...WITH LOWS GENERALLY LOWER 20S. FRIDAY WILL SEE WARMING
WITH A STRENGTHENING SOUTHERLY FLOW ON THE BACKSIDE OF THE HIGH.
HIGH TEMPERATURES WILL RUN LOWER 30S NORTHEAST TO AS WARM AS THE MID
40S THROUGH SOUTH CENTRAL SD.
ON SATURDAY NORTHERN STREAM UPPER LEVEL ENERGY DROPS OUT OF WESTERN
CANADA AND SLIDES SOUTHWARD AS SOUTHERN STREAM ENERGY LIFTS TO THE
NORTH...CONVERGING OVER THE CENTRAL PLAINS. STILL SOME MODEL
DIFFERENCES ON HOW THIS SCENARIO EVOLVES...BUT DOES POTENTIALLY
BRING PRECIPITATION TO AT LEAST OUR SOUTHERN AND EASTERN CWA FOR
LATER ON SATURDAY AFTERNOON AND SATURDAY NIGHT. PRECIPITATION TYPE
LOOKS TO BE MAINLY IN THE FORM OF SNOW...WITH COOLING THERMAL
PROFILES AS LOW PRESSURE OVER THE JAMES BAY BEGINS TO DRIVE COLDER
AIR SOUTHWARD. AT THIS POINT SNOWFALL AMOUNTS LOOK TO BE IN THE
RANGE OF 2 TO 3 INCHES IN OUR SOUTHEAST...THOUGH WILL HAVE TO WATCH
THE TRACK OF THIS SYSTEM FOR GREATER SNOWFALL AMOUNTS IF IT TRENDS
FARTHER TO THE NORTH. IT STILL WONT BE UNREASONABLY COLD ON SATURDAY
WITH HIGHS MAINLY IN THE 30S...BUT BY SATURDAY NIGHT AND SUNDAY MUCH
COLDER AIR WILL HAVE SETTLED INTO THE REGION WITH HIGHS ON SUNDAY
MOSTLY IN THE TEENS. THE COLD AIR THEN LOOKS TO LINGER THROUGH NEXT
MONDAY...WITH SOME MODERATION POSSIBLE BY TUESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 540 AM CST WED JAN 28 2015
MVFR/IFR CEILINGS ARE TRACKING ALONG OUR FAR EASTERN COUNTIES
EARLY THIS MORNING. THIS STRATUS IS NOT EXPECTED TO EXPAND MUCH
FURTHER WEST THIS MORNING...HOWEVER A FAST MOVING FRONT WILL TRACK
WEST TO EAST THROUGH THE FORECAST AREA 18Z THROUGH 00Z THIS
AFTERNOON/EVENING AND USHER IN ADDITION LOW LEVEL CLOUDS BEHIND
IT. STRONG NORTHWEST WINDS BEHIND THE FRONT WILL AVERAGE 20 TO 25
KT WITH FREQUENT GUSTS 30+ KT IN THE EVENING AND OVERNIGHT.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...
LONG TERM...JM
AVIATION...
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1038 AM MST WED JAN 28 2015
.UPDATE...
ISSUED AT 1033 AM MST WED JAN 28 2015
AN UPPER DISTURBANCE OVER WY AND EVIDENT ON SATELLITE WATER VAPOR
IMAGES IS FORECAST BY SHORT-RANGE MODELS TO CLIP NW CO TODAY. THIS
AND TRAILING NW FLOW WILL KEEP SOME LIGHT SNOW ACROSS THE NRN CO
MTNS. A SPOTTER IN CORTEZ REPORTED SOME CUMULUS BUILDING TO THE
NORTHEAST AND INDICATIVE OF SOME INSTABILITY ALOFT BUT THINK THE
AIRMASS TOO DRY FOR ANY SIGNIFICANT THREAT OF SHOWERS FOR THE SAN
JUANS. TRIMMED BACK POPS ACROSS THE GRAND MESA AND WEST ELKS TODAY
PER CURRENT WEBCAM OBS AND LATEST AVAILABLE HRRR GUIDANCE.
OTHERWISE...THE CURRENT FORECAST LOOKS ON TRACK.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 447 AM MST WED JAN 28 2015
THE LOW PRESSURE DISTURBANCE THAT MOVED NORTHWARD THROUGH NV
YESTERDAY HAS BEEN PICKED UP BY THE WESTERLY FLOW OVER THE
NORTHERN TIER STATES...AND HAS MOVED ACROSS SOUTHERN ID AND INTO
FAR SOUTHWEST WY EARLY THIS MORNING. THIS DISTURBANCE WILL
CONTINUE TO BRUSH OUR NORTHERN ZONES THROUGH THE NEXT FEW
HOURS...WITH A NORTHWEST FLOW DEVELOPING BY LATE MORNING. RADAR
ECHOES EARLY THIS MORNING INDICATE SOME LIGHT SHOWER ACTIVITY
OVER THE COLORADO MOUNTAINS...WITH A FEW SHOWERS OVER THE
NORTHERN CO VALLEYS. AS THE TROUGH AXIS PASSES LATER THIS MORNING
A NORTHWEST FLOW WILL DEVELOP WHICH WILL COMBINE WITH THE STILL
MOIST AIR MASS TO KEEP AREAS OF PRECIPITATION OVER THE FAVORED
NORTHERN MOUNTAINS...ESPECIALLY ALONG THE NORTHERN DIVIDE. EARLY
MORNING TEMPERATURES HAVE REMAINED MILD SO RAIN OR MIXED
PRECIPITATION WILL BE POSSIBLE IN THE MIDDLE YAMPA RIVER BASIN
FROM AROUND MILNER WEST. WE DO GET SOME WEAK COOLING IN THE
NORTHWEST FLOW...BUT DAYTIME HIGHS WILL REMAIN ABOVE NORMAL...
BUT SLIGHTLY COOLER THAN TUESDAY`S.
MID-HIGH LEVEL MOISTURE WILL REMAIN OVER THE REGION THROUGH
THURSDAY AS THE RIDGE TEMPORARILY REBOUNDS ALONG THE CENTRAL
ROCKIES. DEEPER MOISTURE WILL BEGIN TO MOVE INTO THE DESERT
SOUTHWEST AHEAD OF ANOTHER LOW PRESSURE SYSTEM COMING ONSHORE
ALONG THE SOUTHWEST COAST. BUT MORE ABOUT THAT IN THE LONG TERM
DISCUSSION.
THE CLOUDY SKIES WILL KEEP TEMPERATURES SIMILAR TO A COUPLE
DEGREES COOLER THAN TODAY`S.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 447 AM MST WED JAN 28 2015
MOISTURE SURGE FROM THE SOUTH COMBINED WITH ISENTROPIC UPGLIDE
RESULTS IN EXPANDING CLOUD/PRECIPITATION SHIELD THURSDAY NIGHT. A
DEVELOPING CLOSED UPPER LOW OVER THE SRN COLORADO RIVER BASIN WILL
KEEP THE AIR MASS MOIST THROUGH SATURDAY. MOST AREAS SOUTH OF HIGHWAY
40 (VERNAL TO STEAMBOAT SPRINGS) STAND A VERY GOOD CHANCE OF OBSERVING
SOME PCPN...BUT DROP OFF SIGNIFICANTLY NORTH OF THIS HIGHWAY.
THE FORECAST CHALLENGE IS HOW MUCH QPF FALLS AND THE PCPN TYPE
(ESPECIALLY THE HIGHER SWRN COLORADO VALLEYS). WHILE SOME MODEL
SPREAD STILL EXISTS REGARDING THE EVOLUTION ON THE DEVELOPING
CLOSED LOW CIRCULATION...THE NAM...GFS AND ECMWF SHOW SIMILAR
TRENDS. THE BEST MOISTURE TRANSPORT STAYS SOUTH AND EAST OF THE
FORECAST AREA...TARGETING THE SOUTHERN PLAINS. SOME CYCLOGENETICAL
FORCING DOES EXIST...BUT THE BULLSEYE STAYS SOUTH OF THE FORECAST
AREA. THE GFS HINTS OF A SURFACE LOW NEAR DURANGO BY SATURDAY
MORNING...BUT NO OTHER MODEL SHOWS THIS AND THEREFORE NOT CONFIDENT
IN THIS SOLUTION. GIVEN THESE ASSESSMENTS...PATTERN FAVORS PCPN
AND HIGH POP VALUES FOR THE SRN HALF IS WARRANTED LATE THURSDAY
NIGHT INTO SATURDAY MORNING. WITH REGARD TO SNOW AMOUNTS...QPF
WITH SNOW RATIOS ON THE ORDER OF 8:1 TO 10:1 MAY ONLY RESULT IN 4
TO 8 INCHES WITH LOCALIZED AREAS REACHING 12 INCHES. WILL ALLOW
THE NEXT SHIFT TO MAKE ANOTHER ASSESSMENT BUT ELECTED NOT TO
ISSUE A WINTER STORM WATCH AT THIS TIME FOR THE SRN MOUNTAINS.
FOR THE SRN VALLEYS BETWEEN 6000 TO 8000 FEET...PCPN TYPE MAY
DEPEND ON THE TIME OF DAY. RAIN IN THE AFTERNOON...BUT
TRANSITIONING TO SNOW OR RAIN/SNOW MIXTURE DURING THE OVERNIGHT
HOURS.
SATURDAY AFTERNOON INTO SUNDAY...NRN STREAM DIVES TOWARD COLORADO
AND SHUNTS MOISTURE SOUTHWARD. THE CLOSED LOW CIRCULATION BEGINS
TO WEAKEN AND MOVE FARTHER SOUTH. THE PROGRESSIVE NRN STREAM SHORT
WAVE BRIEFLY ENHANCES OROGRAPHIC SNOWFALL AND LOWERS THE SNOW
LEVEL...BUT DRIER AIR SPREADS ACROSS THE ENTIRE FORECAST AREA
OVERNIGHT ON SATURDAY INTO SUNDAY.
WITH THE AMPLIFIED RIDGE AXIS GONE...PACIFIC ENERGY CONTINUES TO
MOVE INTO THE PACIFIC NORTHWEST ON MONDAY AND TUESDAY. CYCLONIC
NORTHWEST FLOW ALLOW SHORT WAVE ENERGY TO MOVE ACROSS THE CENTRAL
ROCKIES. THE LONG WAVE PATTERN MAY BE IN STATE OF FLUX HERE AND
NOT CLEAR HOW THESE PACIFIC WAVES WILL IMPACT THE NRN MOUNTAINS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1033 AM MST WED JAN 28 2015
WEAK DISTURBANCE WILL CLIP NW CO TODAY FOLLOWED BY NW FLOW FOR
SOME MTN OBSCURATIONS IN - SN FROM KCCU TO K3MW THIS AFTERNOON. ISOLD
TO SCT -SHSN/-SHRA MAY BRIEFLY PRODUCE MVFR CIGS AT KASE UNTIL
00Z...SO WILL CONTINUE TO CARRY VCSH THERE AS WELL AS AT KEGE.
OTHERWISE...VFR SHOULD BE THE PREVAILING CONDITIONS AT ALL TAF
SITES THROUGH THU MORNING AS HIGH CLOUDS INVADE FROM THE SOUTHWEST.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...JAD
SHORT TERM...EH
LONG TERM...PF
AVIATION...JAD
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
212 PM CST WED JAN 28 2015
.SHORT TERM...
345 AM CST
TODAY THROUGH FRIDAY NIGHT...
MAIN FORECAST CONCERNS IN THE SHORT TERM ARE CLOUD AND TEMP TRENDS
TODAY AND TONIGHT...AND TIMING...COVERAGE AND TYPE OF PRECIPITATION
TONIGHT AND THURSDAY AS LOW PRESSURE ORGANIZING OVER THE PLAINS
MOVES EAST.
RELATIVELY QUIET WEATHER THIS MORNING AS SURFACE HIGH PRESSURE
DRIFTS SLOWLY EAST OF THE AREA. SUBSIDENCE ASSOCIATED WITH HEIGHT
RISES ALOFT HAS LED TO A STRONG INVERSION AT AROUND 900 HPA HOWEVER
PER DVN 00Z SOUNDING...WHICH HAS TRAPPED LOW CLOUDS ACROSS THE
WESTERN PORTIONS OF THE FORECAST AREA OVERNIGHT. CLOUDS WERE SLOWLY
ERODING FROM THE SOUTHEAST THANKS TO 950-900 HPA WINDS GRADUALLY
VEERING TO THE SOUTHEAST AND SOUTH...AND LOWERING SUBSIDENCE
INVERSION. RAP GUIDANCE INDICATES SOUTH WINDS WILL INCREASE THIS
MORNING AND SHOULD CONTINUE TO LIFT THESE LOWER CLOUDS NORTH TOWARD
THE WI BORDER...THOUGH OVERALL NORTH CENTRAL ILLINOIS IS LIKELY TO
BE CLOUDIER THAN AREAS SOUTH AND EAST TODAY EVEN AS MID AND HIGH
CLOUDS BEGIN TO INCREASE AS WARM ADVECTION DEVELOPS ALOFT.
SURFACE LOW PRESSURE IS ALREADY TAKING SHAPE ACROSS THE PLAINS TO
OUR WEST THIS MORNING...IN RESPONSE TO A SHORT WAVE TROUGH EMERGING
FROM THE CENTRAL/NORTHERN ROCKIES. SURFACE PRESSURE FALLS AHEAD OF
THIS DEVELOPING LOW WILL LEAD TO INCREASING SOUTH-SOUTHEAST WINDS
NEAR 25 MPH THIS AFTERNOON. DESPITE SOUTHERLY FLOW...LOW LEVEL
PARCEL TRAJECTORIES WILL BE LARGELY FROM INDIANA/OHIO WHERE STRONG
COOLING HAS OCCURRED NEAR THE SURFACE HIGH THIS MORNING. COMBINED
WITH SOME MID/HIGH CLOUD COVER THIS MAY MAKE FOR HIGH TEMPERATURES
COMING LATER IN THE DAY WHEN LOW LEVEL WINDS VEER MORE SOUTHERLY AND
TAP MILDER AIR CURRENTLY ACROSS THE MISSOURI VALLEY. STRONG SOUTH
FLOW WILL CONTINUE TONIGHT AHEAD OF THE APPROACHING SURFACE
LOW...ALLOWING TEMPS TO STAY ABOVE FREEZING IN MOST AREAS.
GUIDANCE IN GOOD AGREEMENT IN DEVELOPING SOME LIGHT SPOTTY
PRECIPITATION ACROSS THE AREA LATE THIS EVENING...EXPANDING
OVERNIGHT ESPECIALLY ACROSS NORTHERN/NORTHEASTERN PARTS OF THE
FORECAST AREA. FORECAST SOUNDINGS INDICATE WARM LAYER TEMPS ALOFT IN
THE +5C RANGE OR BETTER...WITH SATURATION INITIALLY OCCURRING BELOW
700 HPA AND SUPPORTING LIGHT RAIN. WITH BREEZY SOUTH SURFACE WINDS
KEEPING TEMPS ABOVE MAINLY ABOVE FREEZING...PRECIPITATION TYPE IS
EXPECTED TO REMAIN LIQUID IN MOST LOCATIONS. LOW PROBABILITY DOES
EXIST FOR LIGHT FREEZING RAIN ESPECIALLY ACROSS FAR NORTH/NORTHEAST
IL...BUT AT THIS TIME FEEL IT IS FAIRLY UNLIKELY. THE SURFACE
LOW...AND A PAIR OF UN-PHASED SHORT WAVES....MOVE ACROSS THE CWA
DURING THE MORNING AND RESULT IN WINDS SHIFTING TO THE NORTHWEST.
THIS BRINGS COLDER AIR INTO THE REGION WITH COLLAPSING THICKNESS
FIELDS SUPPORTING LINGERING PRECIPITATION CHANGING OVER FROM LIGHT
RAIN TO A BRIEF RAIN/SLEET/SNOW MIX BEFORE ENDING FROM WEST-EAST.
MOST PRECIPITATION SHOULD END BY NOON WEST OF ABOUT THE IL/IN STATE
LINE...AND SHORTLY AFTER ACROSS NORTHWEST INDIANA. HOWEVER...GUSTY
NORTH-NORTHWEST WINDS AND COLDER AIR SPREADING ACROSS LAKE MICHIGAN
WILL LIKELY SUPPORT LAKE EFFECT SNOW SHOWERS ACROSS PARTS OF EASTERN
LAKE AND PORTER COUNTIES ESPECIALLY THURSDAY EVENING INTO EARLY
FRIDAY MORNING. THE REMAINDER OF THE AREA WILL JUST BE BLUSTERY AND
COLDER...WITH NORTH-NORTHWEST WINDS GUSTING ABOVE 30 MPH AT TIMES
THURSDAY BEFORE SLOWLY DIMINISHING THURSDAY NIGHT. AFTER MORNING
HIGHS IN THE MID-UPPER 30S OR EVEN NEAR 40 IN SOME SPOTS...THURSDAY
NIGHT LOOKS TO BE COLD WITH LOWS IN THE TEENS TO LOW 20S AND SINGLE
DIGIT WIND CHILLS.
SURFACE HIGH PRESSURE SPREADS INTO THE AREA AGAIN ON FRIDAY...WITH
TEMPERATURES STRUGGLING INTO THE MID-UPPER 20S BUT WITH MUCH LIGHTER
WINDS. LAKE SNOW SHOWERS WILL DIMINISH ACROSS NORTHWEST INDIANA AS
INVERSION HEIGHTS LOWER AND LOW LEVEL WINDS DIMINISH...WITH SUNSHINE
ELSEWHERE.
RATZER
&&
.LONG TERM...
345 AM CST
SATURDAY THROUGH TUESDAY...
THE MAIN FOCUS IN THE EXTENDED PERIOD IS ON A STORM SYSTEM WHICH
LOOKS TO LIFT THROUGH THE OHIO VALLEY LATE SATURDAY NIGHT THROUGH
SUNDAY. ECMWF/GFS ARE IN RELATIVELY GOOD AGREEMENT IN TAKING SURFACE
LOW TRACK ALONG THE OHIO RIVER...THOUGH GFS IS A LITTLE SLOWER AND
GEFS ENSEMBLE MEMBERS STILL SHOW QUITE A BIT OF SPREAD IN THEIR
SOLUTIONS AT THE SURFACE. GEM ALSO SLOWER AND A BIT FARTHER SOUTH
THAN THE OTHER GLOBAL MODELS. DEPENDING UPON HOW THIS SYSTEM
EVENTUALLY TRACKS...IT COULD BE A SNOW PRODUCER FOR ALL OR PART OF
THE CWA...AS IT TAPS GULF MOISTURE DEFORMATION BAND WOULD LIKELY
CROSS CENTRAL IL/IN. GLOBAL MODELS ALSO INDICATE A STRONG SURGE OF
ARCTIC AIR IN THE WAKE OF THIS SYSTEM...WITH SIGNIFICANTLY COLDER
WEATHER I.E. LOWS +/- SINGLE DIGITS AND HIGHS PERHAPS ONLY IN THE
TEENS BY MONDAY/TUESDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* GUSTY SOUTH-SOUTHEAST SURFACE WINDS THIS AFTERNOON...POSSIBLY STRENGTHENING
INTO EVENING.
* SCATTERED LIGHT RAIN SHOWERS LIKELY AND MVFR CIGS DEVELOPING
OVERNIGHT...AND THE POSSIBILITY OF A BRIEF MIX WITH SNOW AND IFR BEFORE
ENDING THURSDAY MORNING.
* SOUTH-SOUTHWEST WINDS AT 2000 FT OF AT LEAST 40-45 KT THIS EVENING
INTO OVERNIGHT THAT MAY CREATE LOW-LEVEL WIND SHEAR.
* NORTHWEST WINDS GUSTING TO AROUND 30 KT DURING THE DAY
THURSDAY.
KMD
//DISCUSSION...UPDATED 18Z...
QUITE A FEW AVIATION CONCERNS FOR THIS TAF CYCLE. THE FIRST
CENTERS AROUND WINDS. SE WINDS WILL GRADUALLY RAMP UP THIS
AFTERNOON AND EVENING WITH SUSTAINED WINDS HOLDING IN THE MID
TEENS AND GUSTS INTO 22-24 KT RANGE AHEAD OF LOW PRESSURE MOVING
EAST THROUGH THE PLAINS. THE LOW MOVES THROUGH LATE TONIGHT WITH A
TRAILING COLD FRONT INTO TOMORROW MORNING. AFTER A PERIOD OF
LIGHTER WINDS...NW WINDS RAMP UP QUICKLY MID MORNING THROUGH THE
AFTERNOON. NAM/GFS FORECAST SOUNDINGS SHOW GOOD MIXING THAT WILL
SUPPORT 30 KT OR SO GUSTS THROUGH THE AFTERNOON. AT THIS POINT
LLWS HAS NOT BEEN INTRODUCED AS WINDS AT 2000 FT WILL REACH 40-45
KT WHICH IS ON THE THRESHOLD...BUT WITH THE CONTINUED GUSTINESS IT
IS MARGINAL AT THIS POINT. DURING PERIODS OF LESS FREQUENT GUSTS
THERE COULD BE SOME LLWS.
OTHER CONCERNS REVOLVE AROUND PRECIPITATION EVOLUTION AND TYPE
THROUGH EARLY THURSDAY. SEVERAL MODELS SHOW SOME DECENT LIFT IN
THE WARM ADVECTIVE REGIME THIS EVENING. IN SPITE OF
THIS...GUIDANCE IS MIXED AS TO HOW MUCH MOISTURE THERE WILL
ACTUALLY BE TO SUPPORT PRECIPITATION DURING THIS INITIAL TIME
FRAME. IF PRECIP WERE TO DEVELOP IN THE 4Z-8Z TIME FRAME...SURFACE
TEMPERATURES COULD SUPPORT FZRA. HAVE ONLY GONE WITH A VCSH GIVEN
THE LACK OF MOISTURE ON SOME GUIDANCE...BUT WILL BE A PERIOD TO
WATCH. BETTER CHANCES OF PRECIPITATION COME WITH THE COLD FRONT
LATE TONIGHT INTO EARLY THURSDAY. PRECIP LOOKS TO BE A RAIN OR
DRIZZLE BEFORE TAPERING TO A RAIN SNOW MIX. SURFACE TEMPS HOLD AT
OR ABOVE 32 FOR MOST OF THE PRECIP THUS LITTLE TO NO ACCUMULATION
IS EXPECTED.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH IN WIND DIRECTION AND SPEED THROUGH THIS
EVENING...INCLUDING THE WIND DIRECTION REMAINING SLIGHTLY EAST
OF SOUTH.
* MEDIUM IN PRECIPITATION OCCURRING AT THE AIRFIELD LATER TONIGHT
AND EARLY THURSDAY MORNING. MEDIUM ON PRECIPITATION TYPE.
* MEDIUM THAT LLWS WILL REMAIN MARGINAL THROUGH THE EVENING.
* HIGH IN MVFR CIGS LATE TONIGHT INTO THURSDAY MORNING THOUGH
MEDIUM ON TIMING. MEDIUM IN ANY IFR OCCURRING.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...MAINLY VFR. NORTH-NORTHWEST WINDS.
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...CHANCE OF SNOW DURING THE NIGHT. SOUTHWEST WINDS.
MTF
&&
.MARINE...
211 PM CST
I HAVE UPGRADED THE GALE WATCH TO A WARNING FOR THURSDAY
AFTERNOON AND NIGHT. AN AREA OF LOW PRESSURE APPROACHING THE LAKES
REGION FROM THE PLAINS WILL PRODUCE A PERIOD OF STRONG SOUTHERLY
WINDS AROUND 30 KT TONIGHT...THEN A PERIOD OF NORTHERLY GALE FORCE
WINDS THURSDAY AFTERNOON AND NIGHT AS MUCH COLD AIR SPILLS IN OVER
THE LAKES IN THE WAKE OF THIS LOW. I HAVE INCLUDED MY ILLINOIS
NEAR SHORES IN THIS GALE WARNING AS IT APPEARS THE OFF SHORE
COMPONENT OF THE WIND WILL BE STRONG ENOUGH TO SUPPORT SOME LOW
END GALES.
SURFACE HIGH PRESSURE WILL GRADUALLY BUILD EASTWARD ACROSS THE PLAINS
AND UPPER MIDWEST LATER THURSDAY AND THURSDAY NIGHT...AND THIS
SHOULD ALLOW FOR SOME STRONGER WINDS TO CONTINUE INTO EARLY
FRIDAY...BEFORE DIMINISHING BY FRIDAY AFTERNOON. ANOTHER COLD FRONT
LOOKS TO DROP ACROSS THE LAKES ON SUNDAY...AND A PERIOD OF STRONGER
NORTHERLY WINDS (25 TO 30 KT) APPEAR LIKELY IN ITS WAKE AS A VERY
COLD AIRMASS MOVES SOUTHWARD OVER THE LAKE.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 4 AM THURSDAY.
GALE WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ744-LMZ745-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...NOON
THURSDAY TO 3 AM FRIDAY.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
152 PM CST WED JAN 28 2015
.SHORT TERM...
345 AM CST
TODAY THROUGH FRIDAY NIGHT...
MAIN FORECAST CONCERNS IN THE SHORT TERM ARE CLOUD AND TEMP TRENDS
TODAY AND TONIGHT...AND TIMING...COVERAGE AND TYPE OF PRECIPITATION
TONIGHT AND THURSDAY AS LOW PRESSURE ORGANIZING OVER THE PLAINS
MOVES EAST.
RELATIVELY QUIET WEATHER THIS MORNING AS SURFACE HIGH PRESSURE
DRIFTS SLOWLY EAST OF THE AREA. SUBSIDENCE ASSOCIATED WITH HEIGHT
RISES ALOFT HAS LED TO A STRONG INVERSION AT AROUND 900 HPA HOWEVER
PER DVN 00Z SOUNDING...WHICH HAS TRAPPED LOW CLOUDS ACROSS THE
WESTERN PORTIONS OF THE FORECAST AREA OVERNIGHT. CLOUDS WERE SLOWLY
ERODING FROM THE SOUTHEAST THANKS TO 950-900 HPA WINDS GRADUALLY
VEERING TO THE SOUTHEAST AND SOUTH...AND LOWERING SUBSIDENCE
INVERSION. RAP GUIDANCE INDICATES SOUTH WINDS WILL INCREASE THIS
MORNING AND SHOULD CONTINUE TO LIFT THESE LOWER CLOUDS NORTH TOWARD
THE WI BORDER...THOUGH OVERALL NORTH CENTRAL ILLINOIS IS LIKELY TO
BE CLOUDIER THAN AREAS SOUTH AND EAST TODAY EVEN AS MID AND HIGH
CLOUDS BEGIN TO INCREASE AS WARM ADVECTION DEVELOPS ALOFT.
SURFACE LOW PRESSURE IS ALREADY TAKING SHAPE ACROSS THE PLAINS TO
OUR WEST THIS MORNING...IN RESPONSE TO A SHORT WAVE TROUGH EMERGING
FROM THE CENTRAL/NORTHERN ROCKIES. SURFACE PRESSURE FALLS AHEAD OF
THIS DEVELOPING LOW WILL LEAD TO INCREASING SOUTH-SOUTHEAST WINDS
NEAR 25 MPH THIS AFTERNOON. DESPITE SOUTHERLY FLOW...LOW LEVEL
PARCEL TRAJECTORIES WILL BE LARGELY FROM INDIANA/OHIO WHERE STRONG
COOLING HAS OCCURRED NEAR THE SURFACE HIGH THIS MORNING. COMBINED
WITH SOME MID/HIGH CLOUD COVER THIS MAY MAKE FOR HIGH TEMPERATURES
COMING LATER IN THE DAY WHEN LOW LEVEL WINDS VEER MORE SOUTHERLY AND
TAP MILDER AIR CURRENTLY ACROSS THE MISSOURI VALLEY. STRONG SOUTH
FLOW WILL CONTINUE TONIGHT AHEAD OF THE APPROACHING SURFACE
LOW...ALLOWING TEMPS TO STAY ABOVE FREEZING IN MOST AREAS.
GUIDANCE IN GOOD AGREEMENT IN DEVELOPING SOME LIGHT SPOTTY
PRECIPITATION ACROSS THE AREA LATE THIS EVENING...EXPANDING
OVERNIGHT ESPECIALLY ACROSS NORTHERN/NORTHEASTERN PARTS OF THE
FORECAST AREA. FORECAST SOUNDINGS INDICATE WARM LAYER TEMPS ALOFT IN
THE +5C RANGE OR BETTER...WITH SATURATION INITIALLY OCCURRING BELOW
700 HPA AND SUPPORTING LIGHT RAIN. WITH BREEZY SOUTH SURFACE WINDS
KEEPING TEMPS ABOVE MAINLY ABOVE FREEZING...PRECIPITATION TYPE IS
EXPECTED TO REMAIN LIQUID IN MOST LOCATIONS. LOW PROBABILITY DOES
EXIST FOR LIGHT FREEZING RAIN ESPECIALLY ACROSS FAR NORTH/NORTHEAST
IL...BUT AT THIS TIME FEEL IT IS FAIRLY UNLIKELY. THE SURFACE
LOW...AND A PAIR OF UN-PHASED SHORT WAVES....MOVE ACROSS THE CWA
DURING THE MORNING AND RESULT IN WINDS SHIFTING TO THE NORTHWEST.
THIS BRINGS COLDER AIR INTO THE REGION WITH COLLAPSING THICKNESS
FIELDS SUPPORTING LINGERING PRECIPITATION CHANGING OVER FROM LIGHT
RAIN TO A BRIEF RAIN/SLEET/SNOW MIX BEFORE ENDING FROM WEST-EAST.
MOST PRECIPITATION SHOULD END BY NOON WEST OF ABOUT THE IL/IN STATE
LINE...AND SHORTLY AFTER ACROSS NORTHWEST INDIANA. HOWEVER...GUSTY
NORTH-NORTHWEST WINDS AND COLDER AIR SPREADING ACROSS LAKE MICHIGAN
WILL LIKELY SUPPORT LAKE EFFECT SNOW SHOWERS ACROSS PARTS OF EASTERN
LAKE AND PORTER COUNTIES ESPECIALLY THURSDAY EVENING INTO EARLY
FRIDAY MORNING. THE REMAINDER OF THE AREA WILL JUST BE BLUSTERY AND
COLDER...WITH NORTH-NORTHWEST WINDS GUSTING ABOVE 30 MPH AT TIMES
THURSDAY BEFORE SLOWLY DIMINISHING THURSDAY NIGHT. AFTER MORNING
HIGHS IN THE MID-UPPER 30S OR EVEN NEAR 40 IN SOME SPOTS...THURSDAY
NIGHT LOOKS TO BE COLD WITH LOWS IN THE TEENS TO LOW 20S AND SINGLE
DIGIT WIND CHILLS.
SURFACE HIGH PRESSURE SPREADS INTO THE AREA AGAIN ON FRIDAY...WITH
TEMPERATURES STRUGGLING INTO THE MID-UPPER 20S BUT WITH MUCH LIGHTER
WINDS. LAKE SNOW SHOWERS WILL DIMINISH ACROSS NORTHWEST INDIANA AS
INVERSION HEIGHTS LOWER AND LOW LEVEL WINDS DIMINISH...WITH SUNSHINE
ELSEWHERE.
RATZER
&&
.LONG TERM...
345 AM CST
SATURDAY THROUGH TUESDAY...
THE MAIN FOCUS IN THE EXTENDED PERIOD IS ON A STORM SYSTEM WHICH
LOOKS TO LIFT THROUGH THE OHIO VALLEY LATE SATURDAY NIGHT THROUGH
SUNDAY. ECMWF/GFS ARE IN RELATIVELY GOOD AGREEMENT IN TAKING SURFACE
LOW TRACK ALONG THE OHIO RIVER...THOUGH GFS IS A LITTLE SLOWER AND
GEFS ENSEMBLE MEMBERS STILL SHOW QUITE A BIT OF SPREAD IN THEIR
SOLUTIONS AT THE SURFACE. GEM ALSO SLOWER AND A BIT FARTHER SOUTH
THAN THE OTHER GLOBAL MODELS. DEPENDING UPON HOW THIS SYSTEM
EVENTUALLY TRACKS...IT COULD BE A SNOW PRODUCER FOR ALL OR PART OF
THE CWA...AS IT TAPS GULF MOISTURE DEFORMATION BAND WOULD LIKELY
CROSS CENTRAL IL/IN. GLOBAL MODELS ALSO INDICATE A STRONG SURGE OF
ARCTIC AIR IN THE WAKE OF THIS SYSTEM...WITH SIGNIFICANTLY COLDER
WEATHER I.E. LOWS +/- SINGLE DIGITS AND HIGHS PERHAPS ONLY IN THE
TEENS BY MONDAY/TUESDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* GUSTY SOUTH-SOUTHEAST SURFACE WINDS THIS AFTERNOON...POSSIBLY STRENGTHENING
INTO EVENING.
* SCATTERED LIGHT RAIN SHOWERS LIKELY AND MVFR CIGS DEVELOPING
OVERNIGHT...AND THE POSSIBILITY OF A BRIEF MIX WITH SNOW AND IFR BEFORE
ENDING THURSDAY MORNING.
* SOUTH-SOUTHWEST WINDS AT 2000 FT OF AT LEAST 40-45 KT THIS EVENING
INTO OVERNIGHT THAT MAY CREATE LOW-LEVEL WIND SHEAR.
* NORTHWEST WINDS GUSTING TO AROUND 30 KT DURING THE DAY
THURSDAY.
KMD
//DISCUSSION...UPDATED 18Z...
QUITE A FEW AVIATION CONCERNS FOR THIS TAF CYCLE. THE FIRST
CENTERS AROUND WINDS. SE WINDS WILL GRADUALLY RAMP UP THIS
AFTERNOON AND EVENING WITH SUSTAINED WINDS HOLDING IN THE MID
TEENS AND GUSTS INTO 22-24 KT RANGE AHEAD OF LOW PRESSURE MOVING
EAST THROUGH THE PLAINS. THE LOW MOVES THROUGH LATE TONIGHT WITH A
TRAILING COLD FRONT INTO TOMORROW MORNING. AFTER A PERIOD OF
LIGHTER WINDS...NW WINDS RAMP UP QUICKLY MID MORNING THROUGH THE
AFTERNOON. NAM/GFS FORECAST SOUNDINGS SHOW GOOD MIXING THAT WILL
SUPPORT 30 KT OR SO GUSTS THROUGH THE AFTERNOON. AT THIS POINT
LLWS HAS NOT BEEN INTRODUCED AS WINDS AT 2000 FT WILL REACH 40-45
KT WHICH IS ON THE THRESHOLD...BUT WITH THE CONTINUED GUSTINESS IT
IS MARGINAL AT THIS POINT. DURING PERIODS OF LESS FREQUENT GUSTS
THERE COULD BE SOME LLWS.
OTHER CONCERNS REVOLVE AROUND PRECIPITATION EVOLUTION AND TYPE
THROUGH EARLY THURSDAY. SEVERAL MODELS SHOW SOME DECENT LIFT IN
THE WARM ADVECTIVE REGIME THIS EVENING. IN SPITE OF
THIS...GUIDANCE IS MIXED AS TO HOW MUCH MOISTURE THERE WILL
ACTUALLY BE TO SUPPORT PRECIPITATION DURING THIS INITIAL TIME
FRAME. IF PRECIP WERE TO DEVELOP IN THE 4Z-8Z TIME FRAME...SURFACE
TEMPERATURES COULD SUPPORT FZRA. HAVE ONLY GONE WITH A VCSH GIVEN
THE LACK OF MOISTURE ON SOME GUIDANCE...BUT WILL BE A PERIOD TO
WATCH. BETTER CHANCES OF PRECIPITATION COME WITH THE COLD FRONT
LATE TONIGHT INTO EARLY THURSDAY. PRECIP LOOKS TO BE A RAIN OR
DRIZZLE BEFORE TAPERING TO A RAIN SNOW MIX. SURFACE TEMPS HOLD AT
OR ABOVE 32 FOR MOST OF THE PRECIP THUS LITTLE TO NO ACCUMULATION
IS EXPECTED.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH IN WIND DIRECTION AND SPEED THROUGH THIS
EVENING...INCLUDING THE WIND DIRECTION REMAINING SLIGHTLY EAST
OF SOUTH.
* MEDIUM IN PRECIPITATION OCCURRING AT THE AIRFIELD LATER TONIGHT
AND EARLY THURSDAY MORNING. MEDIUM ON PRECIPITATION TYPE.
* MEDIUM THAT LLWS WILL REMAIN MARGINAL THROUGH THE EVENING.
* HIGH IN MVFR CIGS LATE TONIGHT INTO THURSDAY MORNING THOUGH
MEDIUM ON TIMING. MEDIUM IN ANY IFR OCCURRING.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...MAINLY VFR. NORTH-NORTHWEST WINDS.
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...CHANCE OF SNOW DURING THE NIGHT. SOUTHWEST WINDS.
MTF
&&
.MARINE...
158 AM CST
AN ACTIVE PERIOD WILL UNFOLD OVER LAKE MICHIGAN THROUGH THIS
FORECAST THANKS TO THE PROGRESSIVE NATURE IN THE WEATHER PATTERN.
HIGH PRESSURE EARLY THIS MORNING WILL EXIT THE PICTURE AND A QUICKLY
APPROACHING LOW PRESSURE FROM THE WEST WILL BRING INCREASING
SOUTHERLY WINDS LATER TODAY INTO THIS EVENING. DURING THE EVENING
THERE IS A PERIOD WHERE OCCASIONAL GALES SHOULD OCCUR ACROSS THE
SOUTHERN HALF AS SOME INSTABILITY WILL BE PRESENT WITH GALE FORCE
WINDS ONLY 1000-1500 FT OFF THE WATER SURFACE. THE LOW SHOULD BE
ELONGATED RIGHT DOWN THE AXIS OF THE LAKE AROUND 6 AM THURSDAY
BEFORE IT QUICKLY MOVES EAST. THIS WILL RESULT IN STOUT NORTHWEST
WINDS AND COLD ADVECTION ACROSS THE LAKE WITH WHAT LOOKS LIKE
DEFINITE GALES FOR AT LEAST THE OPEN WATER...INCLUDING 40 KTS
WITH 45 KTS EVEN POSSIBLE ESPECIALLY IN THE NORTH. THIS LIKELY
WILL BRING SOME FREEZING SPRAY THURSDAY NIGHT TO THE OPEN
WATER. AT THIS TIME FORECAST INGREDIENTS ARE A LITTLE SHY FOR
HEAVY FREEZING SPRAY SO NO WATCH FOR THAT ISSUED BUT WILL NEED TO
BE MONITORED.
HAVE OPTED TO GO WITH A GALE WATCH FOR BEHIND THE LOW PRESSURE AS
THAT TIME PERIOD WILL BE THE HIGHEST WINDS WITH THE SYSTEM. WILL
JUST MENTION OCCASIONAL GALES ON THE FRONT SIDE DURING THIS
EVENING ACROSS MAINLY THE SOUTH HALF. SMALL CRAFT ADVISORY
CONDITIONS WILL OBVIOUSLY EXIST A GOOD AMOUNT OF THIS TIME ON THE
ILLINOIS AND INDIANA NEAR SHORES. WITH A SHORT 4-6 HOUR RESPITE
CENTERED ON DAYBREAK THURSDAY AS THE LOW PASSES...HAVE OPTED TO NOT
EXTEND THE CURRENT SMALL CRAFT ADVISORY...BUT ONE WILL DEFINITELY
BE NEEDED FOR THURSDAY AFTERNOON AND NIGHT...AND FOR THE INDIANA
SHORE INTO FRIDAY. THE GALE WATCH DOES INCLUDE PARTS OF THE
INDIANA NEARSHORE THAT WILL FEEL THE GREATER FETCH OF ONSHORE
WINDS AND THUS COULD REALIZE GALES THURSDAY AFTERNOON AND EVENING.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 4 AM THURSDAY.
GALE WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ744-LMZ745-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...NOON
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
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1222 PM CST WED JAN 28 2015
.SHORT TERM...
345 AM CST
TODAY THROUGH FRIDAY NIGHT...
MAIN FORECAST CONCERNS IN THE SHORT TERM ARE CLOUD AND TEMP TRENDS
TODAY AND TONIGHT...AND TIMING...COVERAGE AND TYPE OF PRECIPITATION
TONIGHT AND THURSDAY AS LOW PRESSURE ORGANIZING OVER THE PLAINS
MOVES EAST.
RELATIVELY QUIET WEATHER THIS MORNING AS SURFACE HIGH PRESSURE
DRIFTS SLOWLY EAST OF THE AREA. SUBSIDENCE ASSOCIATED WITH HEIGHT
RISES ALOFT HAS LED TO A STRONG INVERSION AT AROUND 900 HPA HOWEVER
PER DVN 00Z SOUNDING...WHICH HAS TRAPPED LOW CLOUDS ACROSS THE
WESTERN PORTIONS OF THE FORECAST AREA OVERNIGHT. CLOUDS WERE SLOWLY
ERODING FROM THE SOUTHEAST THANKS TO 950-900 HPA WINDS GRADUALLY
VEERING TO THE SOUTHEAST AND SOUTH...AND LOWERING SUBSIDENCE
INVERSION. RAP GUIDANCE INDICATES SOUTH WINDS WILL INCREASE THIS
MORNING AND SHOULD CONTINUE TO LIFT THESE LOWER CLOUDS NORTH TOWARD
THE WI BORDER...THOUGH OVERALL NORTH CENTRAL ILLINOIS IS LIKELY TO
BE CLOUDIER THAN AREAS SOUTH AND EAST TODAY EVEN AS MID AND HIGH
CLOUDS BEGIN TO INCREASE AS WARM ADVECTION DEVELOPS ALOFT.
SURFACE LOW PRESSURE IS ALREADY TAKING SHAPE ACROSS THE PLAINS TO
OUR WEST THIS MORNING...IN RESPONSE TO A SHORT WAVE TROUGH EMERGING
FROM THE CENTRAL/NORTHERN ROCKIES. SURFACE PRESSURE FALLS AHEAD OF
THIS DEVELOPING LOW WILL LEAD TO INCREASING SOUTH-SOUTHEAST WINDS
NEAR 25 MPH THIS AFTERNOON. DESPITE SOUTHERLY FLOW...LOW LEVEL
PARCEL TRAJECTORIES WILL BE LARGELY FROM INDIANA/OHIO WHERE STRONG
COOLING HAS OCCURRED NEAR THE SURFACE HIGH THIS MORNING. COMBINED
WITH SOME MID/HIGH CLOUD COVER THIS MAY MAKE FOR HIGH TEMPERATURES
COMING LATER IN THE DAY WHEN LOW LEVEL WINDS VEER MORE SOUTHERLY AND
TAP MILDER AIR CURRENTLY ACROSS THE MISSOURI VALLEY. STRONG SOUTH
FLOW WILL CONTINUE TONIGHT AHEAD OF THE APPROACHING SURFACE
LOW...ALLOWING TEMPS TO STAY ABOVE FREEZING IN MOST AREAS.
GUIDANCE IN GOOD AGREEMENT IN DEVELOPING SOME LIGHT SPOTTY
PRECIPITATION ACROSS THE AREA LATE THIS EVENING...EXPANDING
OVERNIGHT ESPECIALLY ACROSS NORTHERN/NORTHEASTERN PARTS OF THE
FORECAST AREA. FORECAST SOUNDINGS INDICATE WARM LAYER TEMPS ALOFT IN
THE +5C RANGE OR BETTER...WITH SATURATION INITIALLY OCCURRING BELOW
700 HPA AND SUPPORTING LIGHT RAIN. WITH BREEZY SOUTH SURFACE WINDS
KEEPING TEMPS ABOVE MAINLY ABOVE FREEZING...PRECIPITATION TYPE IS
EXPECTED TO REMAIN LIQUID IN MOST LOCATIONS. LOW PROBABILITY DOES
EXIST FOR LIGHT FREEZING RAIN ESPECIALLY ACROSS FAR NORTH/NORTHEAST
IL...BUT AT THIS TIME FEEL IT IS FAIRLY UNLIKELY. THE SURFACE
LOW...AND A PAIR OF UN-PHASED SHORT WAVES....MOVE ACROSS THE CWA
DURING THE MORNING AND RESULT IN WINDS SHIFTING TO THE NORTHWEST.
THIS BRINGS COLDER AIR INTO THE REGION WITH COLLAPSING THICKNESS
FIELDS SUPPORTING LINGERING PRECIPITATION CHANGING OVER FROM LIGHT
RAIN TO A BRIEF RAIN/SLEET/SNOW MIX BEFORE ENDING FROM WEST-EAST.
MOST PRECIPITATION SHOULD END BY NOON WEST OF ABOUT THE IL/IN STATE
LINE...AND SHORTLY AFTER ACROSS NORTHWEST INDIANA. HOWEVER...GUSTY
NORTH-NORTHWEST WINDS AND COLDER AIR SPREADING ACROSS LAKE MICHIGAN
WILL LIKELY SUPPORT LAKE EFFECT SNOW SHOWERS ACROSS PARTS OF EASTERN
LAKE AND PORTER COUNTIES ESPECIALLY THURSDAY EVENING INTO EARLY
FRIDAY MORNING. THE REMAINDER OF THE AREA WILL JUST BE BLUSTERY AND
COLDER...WITH NORTH-NORTHWEST WINDS GUSTING ABOVE 30 MPH AT TIMES
THURSDAY BEFORE SLOWLY DIMINISHING THURSDAY NIGHT. AFTER MORNING
HIGHS IN THE MID-UPPER 30S OR EVEN NEAR 40 IN SOME SPOTS...THURSDAY
NIGHT LOOKS TO BE COLD WITH LOWS IN THE TEENS TO LOW 20S AND SINGLE
DIGIT WIND CHILLS.
SURFACE HIGH PRESSURE SPREADS INTO THE AREA AGAIN ON FRIDAY...WITH
TEMPERATURES STRUGGLING INTO THE MID-UPPER 20S BUT WITH MUCH LIGHTER
WINDS. LAKE SNOW SHOWERS WILL DIMINISH ACROSS NORTHWEST INDIANA AS
INVERSION HEIGHTS LOWER AND LOW LEVEL WINDS DIMINISH...WITH SUNSHINE
ELSEWHERE.
RATZER
&&
.LONG TERM...
345 AM CST
SATURDAY THROUGH TUESDAY...
THE MAIN FOCUS IN THE EXTENDED PERIOD IS ON A STORM SYSTEM WHICH
LOOKS TO LIFT THROUGH THE OHIO VALLEY LATE SATURDAY NIGHT THROUGH
SUNDAY. ECMWF/GFS ARE IN RELATIVELY GOOD AGREEMENT IN TAKING SURFACE
LOW TRACK ALONG THE OHIO RIVER...THOUGH GFS IS A LITTLE SLOWER AND
GEFS ENSEMBLE MEMBERS STILL SHOW QUITE A BIT OF SPREAD IN THEIR
SOLUTIONS AT THE SURFACE. GEM ALSO SLOWER AND A BIT FARTHER SOUTH
THAN THE OTHER GLOBAL MODELS. DEPENDING UPON HOW THIS SYSTEM
EVENTUALLY TRACKS...IT COULD BE A SNOW PRODUCER FOR ALL OR PART OF
THE CWA...AS IT TAPS GULF MOISTURE DEFORMATION BAND WOULD LIKELY
CROSS CENTRAL IL/IN. GLOBAL MODELS ALSO INDICATE A STRONG SURGE OF
ARCTIC AIR IN THE WAKE OF THIS SYSTEM...WITH SIGNIFICANTLY COLDER
WEATHER I.E. LOWS +/- SINGLE DIGITS AND HIGHS PERHAPS ONLY IN THE
TEENS BY MONDAY/TUESDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* GUSTY SOUTH-SOUTHEAST SURFACE WINDS THIS AFTERNOON...POSSIBLY STRENGTHENING
INTO EVENING.
* SCATTERED LIGHT RAIN SHOWERS LIKELY AND MVFR CIGS DEVELOPING
OVERNIGHT...AND THE POSSIBILITY OF A BRIEF MIX WITH SNOW AND IFR BEFORE
ENDING THURSDAY MORNING.
* SOUTH-SOUTHWEST WINDS AT 2000 FT OF AT LEAST 40-45 KT THIS EVENING
INTO OVERNIGHT THAT MAY CREATE LOW-LEVEL WIND SHEAR.
* NORTHWEST WINDS GUSTING TO AROUND 30 KT DURING THE DAY
THURSDAY.
KMD
//DISCUSSION...UPDATED 18Z...
QUITE A FEW AVIATION CONCERNS FOR THIS TAF CYCLE. THE FIRST
CENTERS AROUND WINDS. SE WINDS WILL GRADUALLY RAMP UP THIS
AFTERNOON AND EVENING WITH SUSTAINED WINDS HOLDING IN THE MID
TEENS AND GUSTS INTO 22-24 KT RANGE AHEAD OF LOW PRESSURE MOVING
EAST THROUGH THE PLAINS. THE LOW MOVES THROUGH LATE TONIGHT WITH A
TRAILING COLD FRONT INTO TOMORROW MORNING. AFTER A PERIOD OF
LIGHTER WINDS...NW WINDS RAMP UP QUICKLY MID MORNING THROUGH THE
AFTERNOON. NAM/GFS FORECAST SOUNDINGS SHOW GOOD MIXING THAT WILL
SUPPORT 30 KT OR SO GUSTS THROUGH THE AFTERNOON. AT THIS POINT
LLWS HAS NOT BEEN INTRODUCED AS WINDS AT 2000 FT WILL REACH 40-45
KT WHICH IS ON THE THRESHOLD...BUT WITH THE CONTINUED GUSTINESS IT
IS MARGINAL AT THIS POINT. DURING PERIODS OF LESS FREQUENT GUSTS
THERE COULD BE SOME LLWS.
OTHER CONCERNS REVOLVE AROUND PRECIPITATION EVOLUTION AND TYPE
THROUGH EARLY THURSDAY. SEVERAL MODELS SHOW SOME DECENT LIFT IN
THE WARM ADVECTIVE REGIME THIS EVENING. IN SPITE OF
THIS...GUIDANCE IS MIXED AS TO HOW MUCH MOISTURE THERE WILL
ACTUALLY BE TO SUPPORT PRECIPITATION DURING THIS INITIAL TIME
FRAME. IF PRECIP WERE TO DEVELOP IN THE 4Z-8Z TIME FRAME...SURFACE
TEMPERATURES COULD SUPPORT FZRA. HAVE ONLY GONE WITH A VCSH GIVEN
THE LACK OF MOISTURE ON SOME GUIDANCE...BUT WILL BE A PERIOD TO
WATCH. BETTER CHANCES OF PRECIPITATION COME WITH THE COLD FRONT
LATE TONIGHT INTO EARLY THURSDAY. PRECIP LOOKS TO BE A RAIN OR
DRIZZLE BEFORE TAPERING TO A RAIN SNOW MIX. SURFACE TEMPS HOLD AT
OR ABOVE 32 FOR MOST OF THE PRECIP THUS LITTLE TO NO ACCUMULATION
IS EXPECTED.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH IN WIND DIRECTION AND SPEED THROUGH THIS
EVENING...INCLUDING THE WIND DIRECTION REMAINING SLIGHTLY EAST
OF SOUTH.
* MEDIUM IN PRECIPITATION OCCURRING AT THE AIRFIELD LATER TONIGHT
AND EARLY THURSDAY MORNING. MEDIUM ON PRECIPITATION TYPE.
* MEDIUM THAT LLWS WILL REMAIN MARGINAL THROUGH THE EVENING.
* HIGH IN MVFR CIGS LATE TONIGHT INTO THURSDAY MORNING THOUGH
MEDIUM ON TIMING. MEDIUM IN ANY IFR OCCURRING.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...MAINLY VFR. NORTH-NORTHWEST WINDS.
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...CHANCE OF SNOW DURING THE NIGHT. SOUTHWEST WINDS.
MTF
&&
.MARINE...
158 AM CST
AN ACTIVE PERIOD WILL UNFOLD OVER LAKE MICHIGAN THROUGH THIS
FORECAST THANKS TO THE PROGRESSIVE NATURE IN THE WEATHER PATTERN.
HIGH PRESSURE EARLY THIS MORNING WILL EXIT THE PICTURE AND A QUICKLY
APPROACHING LOW PRESSURE FROM THE WEST WILL BRING INCREASING
SOUTHERLY WINDS LATER TODAY INTO THIS EVENING. DURING THE EVENING
THERE IS A PERIOD WHERE OCCASIONAL GALES SHOULD OCCUR ACROSS THE
SOUTHERN HALF AS SOME INSTABILITY WILL BE PRESENT WITH GALE FORCE
WINDS ONLY 1000-1500 FT OFF THE WATER SURFACE. THE LOW SHOULD BE
ELONGATED RIGHT DOWN THE AXIS OF THE LAKE AROUND 6 AM THURSDAY
BEFORE IT QUICKLY MOVES EAST. THIS WILL RESULT IN STOUT NORTHWEST
WINDS AND COLD ADVECTION ACROSS THE LAKE WITH WHAT LOOKS LIKE
DEFINITE GALES FOR AT LEAST THE OPEN WATER...INCLUDING 40 KTS
WITH 45 KTS EVEN POSSIBLE ESPECIALLY IN THE NORTH. THIS LIKELY
WILL BRING SOME FREEZING SPRAY THURSDAY NIGHT TO THE OPEN
WATER. AT THIS TIME FORECAST INGREDIENTS ARE A LITTLE SHY FOR
HEAVY FREEZING SPRAY SO NO WATCH FOR THAT ISSUED BUT WILL NEED TO
BE MONITORED.
HAVE OPTED TO GO WITH A GALE WATCH FOR BEHIND THE LOW PRESSURE AS
THAT TIME PERIOD WILL BE THE HIGHEST WINDS WITH THE SYSTEM. WILL
JUST MENTION OCCASIONAL GALES ON THE FRONT SIDE DURING THIS
EVENING ACROSS MAINLY THE SOUTH HALF. SMALL CRAFT ADVISORY
CONDITIONS WILL OBVIOUSLY EXIST A GOOD AMOUNT OF THIS TIME ON THE
ILLINOIS AND INDIANA NEAR SHORES. WITH A SHORT 4-6 HOUR RESPITE
CENTERED ON DAYBREAK THURSDAY AS THE LOW PASSES...HAVE OPTED TO NOT
EXTEND THE CURRENT SMALL CRAFT ADVISORY...BUT ONE WILL DEFINITELY
BE NEEDED FOR THURSDAY AFTERNOON AND NIGHT...AND FOR THE INDIANA
SHORE INTO FRIDAY. THE GALE WATCH DOES INCLUDE PARTS OF THE
INDIANA NEARSHORE THAT WILL FEEL THE GREATER FETCH OF ONSHORE
WINDS AND THUS COULD REALIZE GALES THURSDAY AFTERNOON AND EVENING.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...3 PM WEDNESDAY TO 4 AM THURSDAY.
GALE WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ744-LMZ745-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...NOON
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
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1005 AM CST WED JAN 28 2015
.SHORT TERM...
345 AM CST
TODAY THROUGH FRIDAY NIGHT...
MAIN FORECAST CONCERNS IN THE SHORT TERM ARE CLOUD AND TEMP TRENDS
TODAY AND TONIGHT...AND TIMING...COVERAGE AND TYPE OF PRECIPITATION
TONIGHT AND THURSDAY AS LOW PRESSURE ORGANIZING OVER THE PLAINS
MOVES EAST.
RELATIVELY QUIET WEATHER THIS MORNING AS SURFACE HIGH PRESSURE
DRIFTS SLOWLY EAST OF THE AREA. SUBSIDENCE ASSOCIATED WITH HEIGHT
RISES ALOFT HAS LED TO A STRONG INVERSION AT AROUND 900 HPA HOWEVER
PER DVN 00Z SOUNDING...WHICH HAS TRAPPED LOW CLOUDS ACROSS THE
WESTERN PORTIONS OF THE FORECAST AREA OVERNIGHT. CLOUDS WERE SLOWLY
ERODING FROM THE SOUTHEAST THANKS TO 950-900 HPA WINDS GRADUALLY
VEERING TO THE SOUTHEAST AND SOUTH...AND LOWERING SUBSIDENCE
INVERSION. RAP GUIDANCE INDICATES SOUTH WINDS WILL INCREASE THIS
MORNING AND SHOULD CONTINUE TO LIFT THESE LOWER CLOUDS NORTH TOWARD
THE WI BORDER...THOUGH OVERALL NORTH CENTRAL ILLINOIS IS LIKELY TO
BE CLOUDIER THAN AREAS SOUTH AND EAST TODAY EVEN AS MID AND HIGH
CLOUDS BEGIN TO INCREASE AS WARM ADVECTION DEVELOPS ALOFT.
SURFACE LOW PRESSURE IS ALREADY TAKING SHAPE ACROSS THE PLAINS TO
OUR WEST THIS MORNING...IN RESPONSE TO A SHORT WAVE TROUGH EMERGING
FROM THE CENTRAL/NORTHERN ROCKIES. SURFACE PRESSURE FALLS AHEAD OF
THIS DEVELOPING LOW WILL LEAD TO INCREASING SOUTH-SOUTHEAST WINDS
NEAR 25 MPH THIS AFTERNOON. DESPITE SOUTHERLY FLOW...LOW LEVEL
PARCEL TRAJECTORIES WILL BE LARGELY FROM INDIANA/OHIO WHERE STRONG
COOLING HAS OCCURRED NEAR THE SURFACE HIGH THIS MORNING. COMBINED
WITH SOME MID/HIGH CLOUD COVER THIS MAY MAKE FOR HIGH TEMPERATURES
COMING LATER IN THE DAY WHEN LOW LEVEL WINDS VEER MORE SOUTHERLY AND
TAP MILDER AIR CURRENTLY ACROSS THE MISSOURI VALLEY. STRONG SOUTH
FLOW WILL CONTINUE TONIGHT AHEAD OF THE APPROACHING SURFACE
LOW...ALLOWING TEMPS TO STAY ABOVE FREEZING IN MOST AREAS.
GUIDANCE IN GOOD AGREEMENT IN DEVELOPING SOME LIGHT SPOTTY
PRECIPITATION ACROSS THE AREA LATE THIS EVENING...EXPANDING
OVERNIGHT ESPECIALLY ACROSS NORTHERN/NORTHEASTERN PARTS OF THE
FORECAST AREA. FORECAST SOUNDINGS INDICATE WARM LAYER TEMPS ALOFT IN
THE +5C RANGE OR BETTER...WITH SATURATION INITIALLY OCCURRING BELOW
700 HPA AND SUPPORTING LIGHT RAIN. WITH BREEZY SOUTH SURFACE WINDS
KEEPING TEMPS ABOVE MAINLY ABOVE FREEZING...PRECIPITATION TYPE IS
EXPECTED TO REMAIN LIQUID IN MOST LOCATIONS. LOW PROBABILITY DOES
EXIST FOR LIGHT FREEZING RAIN ESPECIALLY ACROSS FAR NORTH/NORTHEAST
IL...BUT AT THIS TIME FEEL IT IS FAIRLY UNLIKELY. THE SURFACE
LOW...AND A PAIR OF UN-PHASED SHORT WAVES....MOVE ACROSS THE CWA
DURING THE MORNING AND RESULT IN WINDS SHIFTING TO THE NORTHWEST.
THIS BRINGS COLDER AIR INTO THE REGION WITH COLLAPSING THICKNESS
FIELDS SUPPORTING LINGERING PRECIPITATION CHANGING OVER FROM LIGHT
RAIN TO A BRIEF RAIN/SLEET/SNOW MIX BEFORE ENDING FROM WEST-EAST.
MOST PRECIPITATION SHOULD END BY NOON WEST OF ABOUT THE IL/IN STATE
LINE...AND SHORTLY AFTER ACROSS NORTHWEST INDIANA. HOWEVER...GUSTY
NORTH-NORTHWEST WINDS AND COLDER AIR SPREADING ACROSS LAKE MICHIGAN
WILL LIKELY SUPPORT LAKE EFFECT SNOW SHOWERS ACROSS PARTS OF EASTERN
LAKE AND PORTER COUNTIES ESPECIALLY THURSDAY EVENING INTO EARLY
FRIDAY MORNING. THE REMAINDER OF THE AREA WILL JUST BE BLUSTERY AND
COLDER...WITH NORTH-NORTHWEST WINDS GUSTING ABOVE 30 MPH AT TIMES
THURSDAY BEFORE SLOWLY DIMINISHING THURSDAY NIGHT. AFTER MORNING
HIGHS IN THE MID-UPPER 30S OR EVEN NEAR 40 IN SOME SPOTS...THURSDAY
NIGHT LOOKS TO BE COLD WITH LOWS IN THE TEENS TO LOW 20S AND SINGLE
DIGIT WIND CHILLS.
SURFACE HIGH PRESSURE SPREADS INTO THE AREA AGAIN ON FRIDAY...WITH
TEMPERATURES STRUGGLING INTO THE MID-UPPER 20S BUT WITH MUCH LIGHTER
WINDS. LAKE SNOW SHOWERS WILL DIMINISH ACROSS NORTHWEST INDIANA AS
INVERSION HEIGHTS LOWER AND LOW LEVEL WINDS DIMINISH...WITH SUNSHINE
ELSEWHERE.
RATZER
&&
.LONG TERM...
345 AM CST
SATURDAY THROUGH TUESDAY...
THE MAIN FOCUS IN THE EXTENDED PERIOD IS ON A STORM SYSTEM WHICH
LOOKS TO LIFT THROUGH THE OHIO VALLEY LATE SATURDAY NIGHT THROUGH
SUNDAY. ECMWF/GFS ARE IN RELATIVELY GOOD AGREEMENT IN TAKING SURFACE
LOW TRACK ALONG THE OHIO RIVER...THOUGH GFS IS A LITTLE SLOWER AND
GEFS ENSEMBLE MEMBERS STILL SHOW QUITE A BIT OF SPREAD IN THEIR
SOLUTIONS AT THE SURFACE. GEM ALSO SLOWER AND A BIT FARTHER SOUTH
THAN THE OTHER GLOBAL MODELS. DEPENDING UPON HOW THIS SYSTEM
EVENTUALLY TRACKS...IT COULD BE A SNOW PRODUCER FOR ALL OR PART OF
THE CWA...AS IT TAPS GULF MOISTURE DEFORMATION BAND WOULD LIKELY
CROSS CENTRAL IL/IN. GLOBAL MODELS ALSO INDICATE A STRONG SURGE OF
ARCTIC AIR IN THE WAKE OF THIS SYSTEM...WITH SIGNIFICANTLY COLDER
WEATHER I.E. LOWS +/- SINGLE DIGITS AND HIGHS PERHAPS ONLY IN THE
TEENS BY MONDAY/TUESDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* GUSTY SOUTH-SOUTHEAST SURFACE WINDS DEVELOPING BY EARLY
AFTERNOON AND STRENGTHENING INTO EVENING.
* SCATTERED LIGHT RAIN SHOWERS LIKELY AND MVFR CIGS DEVELOPING
OVERNIGHT...AND THE POSSIBILITY OF A BRIEF MIX WITH SNOW AND IFR
VISIBILITY BEFORE ENDING THURSDAY MORNING.
* SOUTH-SOUTHWEST WINDS AT 2000 FT OF AT LEAST 50 KT THIS EVENING
INTO OVERNIGHT THAT MAY CREATE LOW-LEVEL WIND SHEAR.
* NORTHWEST WINDS GUSTING TO AROUND 30 KT DURING THE DAY THURSDAY.
KMD
//DISCUSSION...UPDATED 12Z...
CURRENT BATCH OF MVFR CIGS ACROSS NORTHWEST ILLINOIS EARLY THIS
MORNING IS BEING STEERED ON SOUTHERLY WINDS EARLY THIS
MORNING...WITH RFD LIKELY TO EXPERIENCE AT LEAST TEMPORARY 2000 FT
CIGS OR SO THROUGH MID-MORNING. WITH THE APPROACH OF LOW
PRESSURE...SOUTH-SOUTHEAST WINDS WILL INCREASE WITH GUSTS LIKELY
IN THE AFTERNOON AND PERSISTING...AND LIKELY STRENGTHENING...INTO
THE EVENING AS STRONG PRESSURE FALLS ENVELOP THE REGION. GIVEN THE
CURRENT AND FORECAST PLACEMENT OF THE LOW PRESSURE...THE WIND
DIRECTION SHOULD BE EAST OF SOUTH MUCH OF TODAY AND EARLY THIS
EVENING...BEFORE GRADUALLY VEERING AHEAD OF A FRONT LATE TONIGHT.
A CHANNEL OF STRONG SOUTHWEST WINDS ALOFT...AROUND 2000-3000
FT...ARE LIKELY TO BE 50 PLUS KNOTS TONIGHT AND COULD RESULT IN
SOME LOW-LEVEL WIND SHEAR...ALTHOUGH SURFACE WINDS WILL REMAIN
ALSO INCREASED IN SOMEWHAT MIXED CONDITIONS.
THE COLD FRONT WILL PASS IN THE PRE-DAWN HOURS THURSDAY. AHEAD OF
THIS FRONT SATURATION SHOULD SLOWLY OCCUR NEAR THE INVERSION
LEVEL...WHICH IS EXPECTED TO BE AROUND 2000-3000 FT SO CIGS OF
THAT HEIGHT SHOULD GRADUALLY DEVELOP AS TONIGHT PROGRESSES. IN
ADDITION...THERE WILL BE POTENTIAL FOR SCATTERED RAIN
SHOWERS...WITH ANY RAIN POSSIBLY CHANGING TO A RAIN AND SNOW MIX
AFTER SUNRISE THURSDAY. ANY MIX IS NOT LIKELY TO LAST LONG BEFORE
ENDING...SO ACCUMULATIONS SHOULD BE ONLY A TRACE.
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH IN WIND DIRECTION AND SPEED TODAY AND THIS
EVENING...INCLUDING THE WIND DIRECTION REMAINING SLIGHTLY EAST
OF SOUTH.
* MEDIUM IN PRECIPITATION OCCURRING AT THE AIRFIELD LATER TONIGHT
AND EARLY THURSDAY MORNING.
* HIGH IN MVFR CIGS LATE TONIGHT INTO THURSDAY MORNING. MEDIUM IN ANY
IFR OCCURRING.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...MAINLY VFR. NORTH-NORTHWEST WINDS.
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...CHANCE OF SNOW DURING THE NIGHT. SOUTHWEST WINDS.
MTF
&&
.MARINE...
158 AM CST
AN ACTIVE PERIOD WILL UNFOLD OVER LAKE MICHIGAN THROUGH THIS
FORECAST THANKS TO THE PROGRESSIVE NATURE IN THE WEATHER PATTERN.
HIGH PRESSURE EARLY THIS MORNING WILL EXIT THE PICTURE AND A QUICKLY
APPROACHING LOW PRESSURE FROM THE WEST WILL BRING INCREASING
SOUTHERLY WINDS LATER TODAY INTO THIS EVENING. DURING THE EVENING
THERE IS A PERIOD WHERE OCCASIONAL GALES SHOULD OCCUR ACROSS THE
SOUTHERN HALF AS SOME INSTABILITY WILL BE PRESENT WITH GALE FORCE
WINDS ONLY 1000-1500 FT OFF THE WATER SURFACE. THE LOW SHOULD BE
ELONGATED RIGHT DOWN THE AXIS OF THE LAKE AROUND 6 AM THURSDAY
BEFORE IT QUICKLY MOVES EAST. THIS WILL RESULT IN STOUT NORTHWEST
WINDS AND COLD ADVECTION ACROSS THE LAKE WITH WHAT LOOKS LIKE
DEFINITE GALES FOR AT LEAST THE OPEN WATER...INCLUDING 40 KTS
WITH 45 KTS EVEN POSSIBLE ESPECIALLY IN THE NORTH. THIS LIKELY
WILL BRING SOME FREEZING SPRAY THURSDAY NIGHT TO THE OPEN
WATER. AT THIS TIME FORECAST INGREDIENTS ARE A LITTLE SHY FOR
HEAVY FREEZING SPRAY SO NO WATCH FOR THAT ISSUED BUT WILL NEED TO
BE MONITORED.
HAVE OPTED TO GO WITH A GALE WATCH FOR BEHIND THE LOW PRESSURE AS
THAT TIME PERIOD WILL BE THE HIGHEST WINDS WITH THE SYSTEM. WILL
JUST MENTION OCCASIONAL GALES ON THE FRONT SIDE DURING THIS
EVENING ACROSS MAINLY THE SOUTH HALF. SMALL CRAFT ADVISORY
CONDITIONS WILL OBVIOUSLY EXIST A GOOD AMOUNT OF THIS TIME ON THE
ILLINOIS AND INDIANA NEAR SHORES. WITH A SHORT 4-6 HOUR RESPITE
CENTERED ON DAYBREAK THURSDAY AS THE LOW PASSES...HAVE OPTED TO NOT
EXTEND THE CURRENT SMALL CRAFT ADVISORY...BUT ONE WILL DEFINITELY
BE NEEDED FOR THURSDAY AFTERNOON AND NIGHT...AND FOR THE INDIANA
SHORE INTO FRIDAY. THE GALE WATCH DOES INCLUDE PARTS OF THE
INDIANA NEARSHORE THAT WILL FEEL THE GREATER FETCH OF ONSHORE
WINDS AND THUS COULD REALIZE GALES THURSDAY AFTERNOON AND EVENING.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...3 PM WEDNESDAY TO 4 AM THURSDAY.
GALE WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ744-LMZ745-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...NOON
THURSDAY TO 3 AM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS MARQUETTE MI
445 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 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1247 PM EST WED JAN 28 2015
BASED ON OBS AROUND THE AREA...IT APPEARS VFR CONDITIONS WILL
PREVAIL AT KIWD/KCMX/KSAW THIS AFTN. WILL NEED TO WATCH LOW CLOUDS
STREAMING N UP LAKE MICHIGAN. AS WINDS BACK SLIGHTLY THIS AFTN...
THESE LOWER CLOUDS/MVFR CIGS MAY REACH KSAW EARLIER THAN
ANTICIPATED. 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...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
342 PM CST WED JAN 28 2015
.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 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1155 AM CST WED JAN 28 2015
LOW MVFR/IFR CEILINGS WILL DOMINATE THIS AFTERNOON AND TONIGHT
WITH SOME POTENTIAL FOR VFR CEILINGS TO DEVELOP THURSDAY
AFTERNOON...BUT CONFIDENCE FOR THE VFR CEILINGS IS NOT HIGH AT
THIS TIME. THE MAIN CONCERN OVER THE NEXT 12-15 HOURS IS THE
THREAT FOR FREEZING DRIZZLE AS A LOW PRESSURE SYSTEM MOVES
THROUGH. LITTLE ICE IS INDICATED ALOFT WITH A SATURATED PROFILE
FROM 800MB ON DOWNWARD. THIS IS COUPLED WITH A STRONGLY VEERED LOW
LEVEL WIND PROFILE. SHORT TERM GUIDANCE INDICATES THE BEST
LOCATION IS ALONG AND NORTH OF I-94 IN MN AND ACROSS ALL OF WEST
CENTRAL WI WITH TIMING FROM 00Z-09Z. THEREFORE -FZDZ WAS INDICATED
IN ALL OF THE TAFS WITH THE EXCEPTION OF KRWF. THE WORST AREA
LOOKS TO BE ACROSS WEST CENTRAL WI. IN THE WAKE OF THE
LOW...NORTHWEST WINDS WILL INCREASE WITH SPEEDS OF 15 TO 20 KNOTS
BEFORE DAYBREAK THURSDAY WITH GUSTS IN THE 25 TO 35 KNOT RANGE.
THE HIGHER END SUSTAINED (20KTS) AND GUSTS (35KTS) ARE MOST LIKELY
AT KAXN AND KRWF.
KMSP...CEILINGS MAY LIFT A LITTLE ABOVE 010 THIS AFTERNOON BUT THE
OVERALL TREND IS AT OR BELOW THROUGH EARLY THURSDAY MORNING WITH A
SLOW UP TREND THEREAFTER. CONFIDENCE IS INCREASING ON A FEW HOURS
OF LIGHT FREEZING DRIZZLE WITH THE BEST TIME DURING THE EVENING.
/OUTLOOK FOR KMSP/
THU NGT...MAINLY VFR...CHC MVFR CIGS EARLY. WIND NW 10KT.
FRI...VFR. WIND S 5 KT.
SAT...MAINLY VFR...CHC MVFR CIGS/-SN. WIND NW 5-10 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.
&&
$$
SHORT TERM...RAH
LONG TERM...SPD
AVIATION...RAH
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1158 AM CST WED JAN 28 2015
.UPDATE...
ISSUED AT 1158 AM CST WED JAN 28 2015
NEW 18Z AVIATION DISCUSSION BELOW...
UPDATE ISSUED AT 1123 AM CST WED JAN 28 2015
LATE THIS MORNING...PERSISTENT LOW CLOUDS WERE FOUND ACROSS THE
NORTHLAND. HAVE NOT BEEN ABLE TO FIND ANY REPORTS OF LOCAL
FREEZING DRIZZLE OR OR SNOW AS OF 11 AM. WILL HOLD OFF MENTIONING
FZDZ FOR ANY OF THE DAYTIME HOURS...BUT WILL ADD SOME TO THE
SOUTHERN CWA THIS EVENING FOR A TIME.
UPDATE ISSUED AT 654 AM CST WED JAN 28 2015
ADDED SOME PATCHY FOG THIS MORNING AS SEVERAL LOCATIONS ARE
REPORTING. SHOULD SEE THE FOG LIFT BY 15Z. REST OF THE FORECAST ON
TRACK.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 353 AM CST WED JAN 28 2015
LOW PRESSURE WAS ORGANIZING IN THE DAKOTAS AT 08Z WITH A FRONTAL
BOUNDARY EXTENDING NORTHEASTWARD INTO SOUTHERN MANITOBA AND INTO NW
ONTARIO. IN THE WAA AHEAD OF THIS SYSTEM...SOME LIGHT SNOW WAS
FALLING OVER THE ARROWHEAD WITH LITTLE ACCUMULATION. NORTH OF THE
CANADIAN BORDER...SOME LIGHT FREEZING RAIN WAS OCCURRING RIGHT NEAR
THE FRONT FROM WINNIPEG TO NEAR DRYDEN. LATEST SHORT TERM HRRR AND
RAP KEEP THIS FREEZING RAIN NORTH OF THE BORDER. THE LIGHT SNOW OVER
THE ARROWHEAD IS EXPECTED TO SLOWLY END BY NOON. LITTLE ADDITIONAL
ACCUMULATION IS ANTICIPATED.
BY THIS AFTERNOON...THE SFC LOW MOVES EASTWARD WITH THE LOW CENTER
BEGINS TO REORGANIZE AND DRIFT INTO SOUTHWEST IOWA BY 00Z THURSDAY.
MEANWHILE...A MID LEVEL LONG WAVE TROF MOVES OVER THE WESTERN GREAT
LAKES. SOME MODEL DIFFERENCES BEGIN TO REVEL THEMSELVES WITH RESPECT
TO QPF PLACEMENT AND THE AMOUNT OF COLD AIR FORECAST TO DROP INTO
THE FORECAST AREA. THE GFS IS THE MOST ROBUST AND FURTHEST SOUTH
WHILE THE ECMWF HAS LIMITED QPF AND KEEPS IT NEAR THE CANADIAN
BORDER. HAVE USED A BLENDED APPROACH AND KEPT POPS TO THE NORTHERN
HALF OF THE FORECAST AREA BY LATE AFTERNOON. PRECIPITATION TYPE WILL
BE ALL SNOW. LATEST FORECAST SOUNDINGS ARE NOT SUPPORTING THE
MENTION OF FREEZING RAIN OR FREEZING DRIZZLE AND HAVE REMOVED.
TONIGHT...THE MID LEVEL LONG WAVE TROF MOVES EAST OF THE FORECAST
AREA BY 12Z THURSDAY. THIS PUSHES THE SFC LOW EAST OF THE AREA AS
WELL. BEHIND THIS SYSTEM...A TIGHTENING PRESSURE GRADIENT MOVES OVER
THE WESTERN GREAT LAKES AS HIGH PRESSURE BUILDS INTO THE WESTERN
DAKOTAS. MADE SOME MINOR CHANGES TO THE POPS AND THEIR TIMING ACROSS
THE AREA...WITH THE SNOW ENDING LATE TONIGHT OVER THE SOUTHWEST
PORTION OF THE FORECAST AREA TO THE TWIN PORTS LATE TONIGHT.
FORECAST SOUNDINGS INDICATE THAT THE PRECIPITATION TYPE WILL BE ALL
SNOW AND HAVE REMOVED THE MENTION FREEZING RAIN/FREEZING DRIZZLE AND
SLEET. SNOW AMOUNTS WILL BE LIGHT WITH THE HIGHEST AMOUNTS OF AROUND
ONE HALF INCH FOUND ALONG THE CANADIAN BORDER.
ON THURSDAY...ONLY MADE SOME MINOR CHANGES TO THE POPS AND WEATHER
AS MODELS ARE IN VERY GOOD AGREEMENT. WILL STILL HAVE GUSTY WINDS AS
THE TIGHT PRESSURE GRADIENT REMAINS UNTIL LATE AFTERNOON WHEN THE
AFOREMENTIONED HIGH PRESSURE MOVES INTO THE RED RIVER VALLEY. A NW
WIND OVER LAKE SUPERIOR AND CAA WILL LEAD TO SOME LAKE EFFECT SNOW
ALONG THE HIGHER TERRAIN OF THE SOUTH SHORE. SNOW AMOUNTS WILL BE
LIGHT HOWEVER AS DEEP COLD AIR IS LACKING UNTIL LATE AFTERNOON.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 353 AM CST WED JAN 28 2015
MUCH COLDER AIR ON THE WAY FOR THIS WEEKEND WITH A CHANCE FOR SNOW
FROM...YOU GUESSED IT...ANOTHER WEAK CLIPPER SYSTEM. THE LARGE SCALE
PATTERN WILL UNDERGO SOME CHANGES THROUGH THE LONG TERM THAT WILL
/AT LEAST TEMPORARILY/ PUT A STOP TO WHAT HAS BEEN A LONG PERIOD OF
WEAK /AND FRANKLY DISAPPOINTING FOR SNOW LOVERS/ CLIPPERS.
TEMPERATURES WILL DROP FROM WHAT HAS BEEN A VERY MILD PATTERN TO A
COLDER REGIME...ENDING THE LAST WEEK OF JANUARY WITH TEMPS SIMILAR
TO THE FIRST WEEK OF THE MONTH.
ON THE SYNOPTIC SCALE A SERIES OF STRONG ARCTIC AIR MASSES WILL DROP
DOWN INTO THE NORTHERN PLAINS AND UPPER MIDWEST. LATE THIS WEEK AN
AREA OF HIGH PRESSURE WILL MOVE OVER THE AREA THURSDAY NIGHT
FOLLOWED BY A WEAK CLIPPER ON FRIDAY/FRIDAY NIGHT. THEN LATE IN THE
WEEKEND A DEEP LONGWAVE TROUGH AT MID-LEVELS WILL DESCEND OVER THE
MIDWEST LEADING TO VERY COLD AIR ALOFT...850MB TEMPS APPROACHING THE
COLDEST 10 PERCENT OF CLIMATOLOGY IN THE MID -20S C /COMPARED TO 00Z
TODAY WHEN THEY WERE IN THE WARMEST 10 PERCENT OF CLIMO AT AROUND
0C/.
BEST CHANCE FOR SNOWFALL ACROSS THE REGION WILL BE LATE FRIDAY
AFTERNOON INTO FRIDAY NIGHT A CLIPPER MOVES ACROSS. GFS AND ECMWF IN
GOOD AGREEMENT ON TIMING...WITH ECMWF PESSIMISTIC ON INTENSITY AND
GFS A LITTLE STRONGER WITH A DEEPER MOISTURE PROFILE. GEM WAS SLOWER
AND NOT AS INTENSE OVERALL...BUT THIS WAS A PRETTY BIG CHANGE FROM
12Z GEM WHICH WAS FASTER AND MUCH MORE AGGRESSIVE ON PRECIP. AT THIS
POINT IT LOOKS LIKE A QUICK INCH OR TWO FOR NORTHERN MINNESOTA NORTH
OF HIGHWAY TWO. OTHERWISE NO SIGNIFICANT CHANCES FOR PRECIP IN THE
SEVEN DAY FOR MUCH OF THE REGION...WITH THE EXCEPTION OF LAKE EFFECT
SNOWFALL ALONG PORTIONS OF THE SOUTH SHORE OF LAKE SUPERIOR.
LAKE EFFECT SNOWFALL WILL BE PRESENT THROUGH MUCH OF THE LONG TERM
PERIOD. ON THURSDAY NIGHT CONDITIONS WILL BE GOOD FOR LAKE EFFECT
SNOWFALL ALONG THE HIGHER TERRAIN OF IRON/ASHLAND COUNTIES WITH
STEEP LOW LEVEL LAPSE RATES THROUGH 850MB AND GREAT NORTH/NORTHWEST
FLOW OVER THE LAKE. ICE COVERAGE ON THE SOUTH SHORE MAY LIMIT THE
INTENSITY OF LAKE EFFECT SNOWFALL...AND OPTED TO LEAVE NORTHERN
BAYFIELD COUNTY OUT OF HIGHER CHANCES FOR LAKE EFFECT SNOWFALL DUE
TO WHAT WOULD BE A VERY LIMITED FETCH LENGTH. LOW LEVEL MOISTURE
WILL ALSO BE A FACTOR AS NAM/GFS/ECMWF DEPICT A NEAR-SURFACE DRY
LAYER...SO IT MAY TAKE A WHILE TO SATURATE LOW LEVELS AND THUS LIMIT
SNOWFALL AMOUNTS. LAKE EFFECT WILL TAPER OFF AS HIGH PRESSURE MOVES
OVER LAKE SUPERIOR ON FRIDAY AFTERNOON...BUT RAMP BACK UP AGAIN ON
SATURDAY AND THROUGH ABOUT TUESDAY DUE TO THE VERY COLD AIRMASS THAT
WILL BE IN PLACE.
TEMPS WILL BE ON A DOWNWARD TREND...AND HAVE ADJUSTED SOME OF THE
USUAL COLD SPOTS A LITTLE COLDER THAN INITIAL GUIDANCE TO ACCOUNT
FOR THE ARCTIC HIGHS THAT WILL BE OVER NORTHEASTERN MINNESOTA IN THE
LONG TERM. HIGHS IN THE MID TEENS TO MID 20S ON SATURDAY...THEN THE
SINGLE DIGITS ON SUNDAY AND MONDAY BEFORE RECOVERING TO THE TEENS
TUESDAY. LOWS NEAR ZERO TO TEN OR MORE BELOW ZERO ON THURSDAY
NIGHT...MILD FRIDAY NIGHT DUE TO WEAK SOUTHERLY WINDS...THEN 0 TO
-15 SATURDAY NIGHT AND 10 TO 20 BELOW ZERO ON SUNDAY NIGHT. MONDAY
MORNING WILL BE THE COLDEST PERIOD IN THE LONG TERM WITH WIND CHILL
VALUES OF 25 TO 35 BELOW ZERO...AND COLD SPOTS IN THE TIP OF THE
ARROWHEAD REGION NEAR 40 BELOW ZERO.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1158 AM CST WED JAN 28 2015
IFR/LIFR CIGS AND MVFR/IFR VSBYS WERE FOUND ACROSS THE AREA LATE
THIS MORNING...AND THAT TREND SHOULD CONTINUE INTO THIS AFTERNOON
AT ALL TERMINALS. AREAS OF LIGHT SNOW/FREEZING DRIZZLE/FREEZING
FOG HAVE BEEN REPORTED OVER NORTHWEST MINNESOTA AND PORTIONS OF
NORTHWESTERN ONTARIO...AND EXPECT PRECIPITATION TO MOVE INTO INL
LATER THIS AFTERNOON. CONFIDENCE IN PRECIPITATION TYPE IS LOW...BUT
IT SEEMS FREEZING DRIZZLE/FREEZING FOG ARE MORE LIKELY THAN LIGHT
SNOW WITH THIS PACKAGE. AS DEEPER SATURATION EXPANDS ACROSS
REMAINING MN AIRPORTS THIS AFTERNOON...INTRODUCED A MIX OF
FREEZING DRIZZLE/LIGHT SNOW BEFORE 29.00Z. THE PRECIPITATION WILL
BE SLOWEST TO ARRIVE AT HAYWARD...WHERE ONSET SHOULD BE DELAYED
UNTIL THIS EVENING.
FOCUS THEN SHIFTS TO AN APPROACHING COLD FRONT LATER OVERNIGHT AND
COLD AIR POURING INTO THE AREA ON THURSDAY. WINDS WILL VEER
NORTHWEST THIS EVENING...BUT THE INCREASE IN SPEEDS WILL BE
DELAYED UNTIL LATE OVERNIGHT/EARLY THURSDAY MORNING. TEMPERATURES
WILL COOL SUFFICIENTLY TO SWITCH PRECIPITATION TO ALL SNOW AND THE
STRONG WINDS WILL RESULT IN MVFR VSBYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 31 24 24 -1 / 10 50 10 0
INL 31 16 16 -10 / 10 60 10 0
BRD 34 22 22 5 / 10 40 0 0
HYR 32 27 28 -2 / 10 50 20 0
ASX 34 27 29 2 / 10 50 20 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...DAP
SHORT TERM...GSF
LONG TERM...JJM
AVIATION...HUYCK
AREA FORECAST DISCUSSION
NWS DULUTH MN
1132 AM CST WED JAN 28 2015
.UPDATE...
ISSUED AT 1123 AM CST WED JAN 28 2015
LATE THIS MORNING...PERSISTENT LOW CLOUDS WERE FOUND ACROSS THE
NORTHLAND. HAVE NOT BEEN ABLE TO FIND ANY REPORTS OF LOCAL
FREEZING DRIZZLE OR OR SNOW AS OF 11 AM. WILL HOLD OFF MENTIONING
FZDZ FOR ANY OF THE DAYTIME HOURS...BUT WILL ADD SOME TO THE
SOUTHERN CWA THIS EVENING FOR A TIME.
UPDATE ISSUED AT 654 AM CST WED JAN 28 2015
ADDED SOME PATCHY FOG THIS MORNING AS SEVERAL LOCATIONS ARE
REPORTING. SHOULD SEE THE FOG LIFT BY 15Z. REST OF THE FORECAST ON
TRACK.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 353 AM CST WED JAN 28 2015
LOW PRESSURE WAS ORGANIZING IN THE DAKOTAS AT 08Z WITH A FRONTAL
BOUNDARY EXTENDING NORTHEASTWARD INTO SOUTHERN MANITOBA AND INTO NW
ONTARIO. IN THE WAA AHEAD OF THIS SYSTEM...SOME LIGHT SNOW WAS
FALLING OVER THE ARROWHEAD WITH LITTLE ACCUMULATION. NORTH OF THE
CANADIAN BORDER...SOME LIGHT FREEZING RAIN WAS OCCURRING RIGHT NEAR
THE FRONT FROM WINNIPEG TO NEAR DRYDEN. LATEST SHORT TERM HRRR AND
RAP KEEP THIS FREEZING RAIN NORTH OF THE BORDER. THE LIGHT SNOW OVER
THE ARROWHEAD IS EXPECTED TO SLOWLY END BY NOON. LITTLE ADDITIONAL
ACCUMULATION IS ANTICIPATED.
BY THIS AFTERNOON...THE SFC LOW MOVES EASTWARD WITH THE LOW CENTER
BEGINS TO REORGANIZE AND DRIFT INTO SOUTHWEST IOWA BY 00Z THURSDAY.
MEANWHILE...A MID LEVEL LONG WAVE TROF MOVES OVER THE WESTERN GREAT
LAKES. SOME MODEL DIFFERENCES BEGIN TO REVEL THEMSELVES WITH RESPECT
TO QPF PLACEMENT AND THE AMOUNT OF COLD AIR FORECAST TO DROP INTO
THE FORECAST AREA. THE GFS IS THE MOST ROBUST AND FURTHEST SOUTH
WHILE THE ECMWF HAS LIMITED QPF AND KEEPS IT NEAR THE CANADIAN
BORDER. HAVE USED A BLENDED APPROACH AND KEPT POPS TO THE NORTHERN
HALF OF THE FORECAST AREA BY LATE AFTERNOON. PRECIPITATION TYPE WILL
BE ALL SNOW. LATEST FORECAST SOUNDINGS ARE NOT SUPPORTING THE
MENTION OF FREEZING RAIN OR FREEZING DRIZZLE AND HAVE REMOVED.
TONIGHT...THE MID LEVEL LONG WAVE TROF MOVES EAST OF THE FORECAST
AREA BY 12Z THURSDAY. THIS PUSHES THE SFC LOW EAST OF THE AREA AS
WELL. BEHIND THIS SYSTEM...A TIGHTENING PRESSURE GRADIENT MOVES OVER
THE WESTERN GREAT LAKES AS HIGH PRESSURE BUILDS INTO THE WESTERN
DAKOTAS. MADE SOME MINOR CHANGES TO THE POPS AND THEIR TIMING ACROSS
THE AREA...WITH THE SNOW ENDING LATE TONIGHT OVER THE SOUTHWEST
PORTION OF THE FORECAST AREA TO THE TWIN PORTS LATE TONIGHT.
FORECAST SOUNDINGS INDICATE THAT THE PRECIPITATION TYPE WILL BE ALL
SNOW AND HAVE REMOVED THE MENTION FREEZING RAIN/FREEZING DRIZZLE AND
SLEET. SNOW AMOUNTS WILL BE LIGHT WITH THE HIGHEST AMOUNTS OF AROUND
ONE HALF INCH FOUND ALONG THE CANADIAN BORDER.
ON THURSDAY...ONLY MADE SOME MINOR CHANGES TO THE POPS AND WEATHER
AS MODELS ARE IN VERY GOOD AGREEMENT. WILL STILL HAVE GUSTY WINDS AS
THE TIGHT PRESSURE GRADIENT REMAINS UNTIL LATE AFTERNOON WHEN THE
AFOREMENTIONED HIGH PRESSURE MOVES INTO THE RED RIVER VALLEY. A NW
WIND OVER LAKE SUPERIOR AND CAA WILL LEAD TO SOME LAKE EFFECT SNOW
ALONG THE HIGHER TERRAIN OF THE SOUTH SHORE. SNOW AMOUNTS WILL BE
LIGHT HOWEVER AS DEEP COLD AIR IS LACKING UNTIL LATE AFTERNOON.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 353 AM CST WED JAN 28 2015
MUCH COLDER AIR ON THE WAY FOR THIS WEEKEND WITH A CHANCE FOR SNOW
FROM...YOU GUESSED IT...ANOTHER WEAK CLIPPER SYSTEM. THE LARGE SCALE
PATTERN WILL UNDERGO SOME CHANGES THROUGH THE LONG TERM THAT WILL
/AT LEAST TEMPORARILY/ PUT A STOP TO WHAT HAS BEEN A LONG PERIOD OF
WEAK /AND FRANKLY DISAPPOINTING FOR SNOW LOVERS/ CLIPPERS.
TEMPERATURES WILL DROP FROM WHAT HAS BEEN A VERY MILD PATTERN TO A
COLDER REGIME...ENDING THE LAST WEEK OF JANUARY WITH TEMPS SIMILAR
TO THE FIRST WEEK OF THE MONTH.
ON THE SYNOPTIC SCALE A SERIES OF STRONG ARCTIC AIR MASSES WILL DROP
DOWN INTO THE NORTHERN PLAINS AND UPPER MIDWEST. LATE THIS WEEK AN
AREA OF HIGH PRESSURE WILL MOVE OVER THE AREA THURSDAY NIGHT
FOLLOWED BY A WEAK CLIPPER ON FRIDAY/FRIDAY NIGHT. THEN LATE IN THE
WEEKEND A DEEP LONGWAVE TROUGH AT MID-LEVELS WILL DESCEND OVER THE
MIDWEST LEADING TO VERY COLD AIR ALOFT...850MB TEMPS APPROACHING THE
COLDEST 10 PERCENT OF CLIMATOLOGY IN THE MID -20S C /COMPARED TO 00Z
TODAY WHEN THEY WERE IN THE WARMEST 10 PERCENT OF CLIMO AT AROUND
0C/.
BEST CHANCE FOR SNOWFALL ACROSS THE REGION WILL BE LATE FRIDAY
AFTERNOON INTO FRIDAY NIGHT A CLIPPER MOVES ACROSS. GFS AND ECMWF IN
GOOD AGREEMENT ON TIMING...WITH ECMWF PESSIMISTIC ON INTENSITY AND
GFS A LITTLE STRONGER WITH A DEEPER MOISTURE PROFILE. GEM WAS SLOWER
AND NOT AS INTENSE OVERALL...BUT THIS WAS A PRETTY BIG CHANGE FROM
12Z GEM WHICH WAS FASTER AND MUCH MORE AGGRESSIVE ON PRECIP. AT THIS
POINT IT LOOKS LIKE A QUICK INCH OR TWO FOR NORTHERN MINNESOTA NORTH
OF HIGHWAY TWO. OTHERWISE NO SIGNIFICANT CHANCES FOR PRECIP IN THE
SEVEN DAY FOR MUCH OF THE REGION...WITH THE EXCEPTION OF LAKE EFFECT
SNOWFALL ALONG PORTIONS OF THE SOUTH SHORE OF LAKE SUPERIOR.
LAKE EFFECT SNOWFALL WILL BE PRESENT THROUGH MUCH OF THE LONG TERM
PERIOD. ON THURSDAY NIGHT CONDITIONS WILL BE GOOD FOR LAKE EFFECT
SNOWFALL ALONG THE HIGHER TERRAIN OF IRON/ASHLAND COUNTIES WITH
STEEP LOW LEVEL LAPSE RATES THROUGH 850MB AND GREAT NORTH/NORTHWEST
FLOW OVER THE LAKE. ICE COVERAGE ON THE SOUTH SHORE MAY LIMIT THE
INTENSITY OF LAKE EFFECT SNOWFALL...AND OPTED TO LEAVE NORTHERN
BAYFIELD COUNTY OUT OF HIGHER CHANCES FOR LAKE EFFECT SNOWFALL DUE
TO WHAT WOULD BE A VERY LIMITED FETCH LENGTH. LOW LEVEL MOISTURE
WILL ALSO BE A FACTOR AS NAM/GFS/ECMWF DEPICT A NEAR-SURFACE DRY
LAYER...SO IT MAY TAKE A WHILE TO SATURATE LOW LEVELS AND THUS LIMIT
SNOWFALL AMOUNTS. LAKE EFFECT WILL TAPER OFF AS HIGH PRESSURE MOVES
OVER LAKE SUPERIOR ON FRIDAY AFTERNOON...BUT RAMP BACK UP AGAIN ON
SATURDAY AND THROUGH ABOUT TUESDAY DUE TO THE VERY COLD AIRMASS THAT
WILL BE IN PLACE.
TEMPS WILL BE ON A DOWNWARD TREND...AND HAVE ADJUSTED SOME OF THE
USUAL COLD SPOTS A LITTLE COLDER THAN INITIAL GUIDANCE TO ACCOUNT
FOR THE ARCTIC HIGHS THAT WILL BE OVER NORTHEASTERN MINNESOTA IN THE
LONG TERM. HIGHS IN THE MID TEENS TO MID 20S ON SATURDAY...THEN THE
SINGLE DIGITS ON SUNDAY AND MONDAY BEFORE RECOVERING TO THE TEENS
TUESDAY. LOWS NEAR ZERO TO TEN OR MORE BELOW ZERO ON THURSDAY
NIGHT...MILD FRIDAY NIGHT DUE TO WEAK SOUTHERLY WINDS...THEN 0 TO
-15 SATURDAY NIGHT AND 10 TO 20 BELOW ZERO ON SUNDAY NIGHT. MONDAY
MORNING WILL BE THE COLDEST PERIOD IN THE LONG TERM WITH WIND CHILL
VALUES OF 25 TO 35 BELOW ZERO...AND COLD SPOTS IN THE TIP OF THE
ARROWHEAD REGION NEAR 40 BELOW ZERO.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 526 AM CST WED JAN 28 2015
GENERALLY IFR CONDITIONS THROUGH MOST OF THE TAF PERIOD AT ALL SITES
DUE TO LOW CEILINGS AND PATCHY FOG DEVELOPING. AS OF THIS MORNING
ALL TAF SITES EXCEPT FOR INL WERE ALREADY AT IFR CONDITIONS...WITH
INL CEILINGS EXPECTED TO WORSEN LATER THIS MORNING. THERE WILL BE
LITTLE IMPROVEMENT THROUGH THE DAY WITH SOME SITES POSSIBLY
DETERIORATING TO LIFR CEILINGS AND IFR VISIBILITY THIS AFTERNOON.
TONIGHT A COLD FRONT WILL MOVE THROUGH WHICH WILL IMPROVE
CONDITIONS...WITH CEILINGS IMPROVING TO MVFR LEVELS. WINDS WILL BE
LIGHT TODAY OUT OF THE SOUTH...BUT BEHIND THE COLD FRONT LATE
TONIGHT WINDS WILL RAPIDLY INCREASE TO BECOME 10 TO 15 KTS OUT OF
THE WEST WITH GUSTS APPROACHING/EXCEEDING 30 KTS AT TIMES. DID NOT
INCLUDE STRONG WINDS IN ALL TAFS SINCE TIMING WILL BE RIGHT AROUND
END OF THE TAF PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 31 24 24 -1 / 10 50 10 0
INL 31 16 16 -10 / 10 60 10 0
BRD 34 22 22 5 / 10 40 0 0
HYR 32 27 28 -2 / 10 50 20 0
ASX 34 27 29 2 / 10 50 20 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...DAP
SHORT TERM...GSF
LONG TERM...JJM
AVIATION...JJM
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1100 AM CST WED JAN 28 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 344 AM CST WED JAN 28 2015
BEEN ANOTHER QUIET NIGHT ACROSS THE AREA...THANKS TO AN UPPER
LEVEL SHORTWAVE RIDGE AXIS THAT HAS BEEN STEADILY MAKING ITS WAY
EAST THROUGH THE PLAINS...PUSHED BY AN UPPER LEVEL DISTURBANCE
MOVING INTO WRN PORTIONS OF WY. AT THE SURFACE...THE PATTERN OVER
THE CWA IS ONCE AGAIN ON THE WEAKER SIDE...WITH A TROUGH AXIS SET
UP OVER THE HIGH PLAINS...RESULTING IN LIGHT AND AT TIMES VARIABLE
WINDS. TEMPS EARLY THIS MORNING AT 3 AM RANGE ANYWHERE FROM THE
MID 20S IN THE NORTH TO MID 40S IN THE FAR SWRN CORNER OF THE CWA.
THE MAIN STORY THROUGH THE SHORT TERM PERIOD LIES WITH THAT UPPER
LEVEL DISTURBANCE PUSHING INTO WY THIS MORNING...AND THE
ACCOMPANYING FRONTAL BOUNDARY IT WILL PUSH THROUGH THE CWA. MODELS
ARE IN PRETTY GOOD AGREEMENT WITH THE TIMING OF THIS
DISTURBANCE...SHOWING IT MOVING INTO THE NEB PANHANDLE NEAR MIDDAY
TODAY...BY 00Z THIS EVENING THE TROUGH AXIS LOOKS TO BE EXTENDING
THROUGH THE HEART OF THE CWA...BEFORE PUSHING OFF TO THE MISSOURI
RIVER AREA BY MIDNIGHT TONIGHT. A WEAKER SECOND MID LEVEL
DISTURBANCE QUICK ON THE HEELS OF THE MAIN ONE IS FORECAST TO BE
WORKING INTO THE AREA AS WE GET INTO THE EARLY MORNING HOURS
THURSDAY. EVEN WITH THERE ACTUALLY BEING A SYSTEM TO TALK
ABOUT...MODELS /INCLUDING THE MORE SHORT TERM HIRES LIKE THE WRF/
OVERALL CONTINUE TO BE IN GOOD AGREEMENT SHOWING CONDITIONS
REMAINING DRY...JUST NOT A LOT OF MOISTURE TO WORK WITH. THAT
BEING SAID...SOME MODELS ARE HINTING AT THE POTENTIAL OF SOME VERY
LIGHT PRECIP FALLING THIS EVENING/OVERNIGHT...BUT KEEP THAT SIGNAL
JUST OUTSIDE THE N/NERN BORDERS OF THE CWA. WILL BE SOMETHING FOR
THE DAY SHIFT TO MONITOR WITH THE 12Z RUN OF MODELS THIS MORNING.
AT THE SFC...WINDS WILL REMAIN ON THE LIGHTER SIDE THIS
MORNING...BEFORE THE WIND SHIFT OF THE COLD FRONT ACCOMPANYING
THIS SYSTEM PASSES THROUGH THE CWA...WHICH MODELS SHOW PUSHING
ABOUT HALFWAY THROUGH THE CWA BY MID MORNING AND MAKING IT TO THE
ERN FRINGE OF THE CWA AROUND MIDDAY. THIS WILL USHER IN A PUSH OF
GUSTY W/NWRLY WINDS /15 TO 25 MPH IS FORECAST/...BUT THE MAIN PUSH
OF COLDER AIR IS LAGGING BEHIND. TEMPS ALOFT COOL A TOUCH DURING
THE DAY...BUT HIGHS ARE STILL FORECAST TO BE WELL ABOVE
AVERAGE...THANKS TO THE MILD AIR/DOWNSLOPING WINDS. NOT EXPECTED
TO BE AS WARM AS TUESDAY...BUT TRENDED HIGHS TOWARD THE MAV AND
RAP /WHICH DID PRETTY WELL TUESDAY/...WHICH PUTS THE MAJORITY OF
THE CWA AT LEAST INTO THE MID 60S /THE EXCEPTION AGAIN IS THE
E/NERN PORTIONS/...WITH HIGHS NEAR 70 FORECAST IN NC KS. IF TEMPS
PAN OUT AS FORECAST...IT WOULD SET A NEW RECORD HIGH TEMPS IN
GRAND ISLAND. BUT CONFIDENCE ISNT THE HIGHEST...AS THERE ARE
MODELS THAT SAY IT WILL FALL SHORT OF/MAYBE TIE THE RECORD OF 63
DEGREES. THE RECORD AT HASTINGS IS 69 DEGREES...AND THE RAP IS
BASICALLY THE ONLY ONE SHOWING THE POTENTIAL FOR TEMPS TO MAKE A
RUN AT THAT RECORD. FIRE WX CONCERNS ARISE AGAIN...SEE FIRE
WEATHER SECTION BELOW FOR ADDITIONAL INFORMATION.
THIS EVENING/TONIGHT...ONE MIGHT THINK THAT WINDS WE HAVE THIS
AFTERNOON WOULD TAPER OFF...BUT WITH THE MAIN PUSH OF COLD AIR
ADVECTION...BETTER PRESSURE RISES/TIGHTER PRESSURE GRADIENT...AND
STRONGER WINDS ALOFT TO TAP INTO...THATS NOT THE CASE. MADE SOME
ADJUSTMENTS TO WIND SPEEDS...WHICH WILL BE ON A SECOND INCREASE
THIS EVENING...AND BY MIDNIGHT TONIGHT SPEEDS IN THE 25 TO 30
MPH RANGE WILL BE POSSIBLE...MAINLY ACROSS OUR SC NEB COUNTIES.
LOOKS TO REMAIN BREEZY INTO THE EARLY MORNING HOURS THURSDAY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 344 AM CST WED JAN 28 2015
GUIDANCE SUGGESTS AN UPPER TROPOSPHERIC SHORT WAVE WILL BE NOTED
OVER THE MID-MISSISSIPPI VALLEY TO START THE LONG-TERM FORECAST
PERIOD AT 12Z THURSDAY...THUS HELPING PROVIDE NORTHWESTERLY UPPER
TROPOSPHERIC FLOW OVER OUR AREA. THIS NORTHWESTERLY FLOW IS
EXPECTED TO PERSIST OVER OUR AREA THURSDAY INTO THURSDAY NIGHT
BEFORE THE APPROACH OF AN UPPER TROPOSPHERIC LONGWAVE TROUGH AXIS
PROMOTES QUASI-ZONAL TO SOUTHWESTERLY UPPER TROPOSPHERIC FLOW
FRIDAY THROUGH SATURDAY. THIS UPPER TROPOSPHERIC TROUGH AXIS IS
EXPECTED TO CLEAR OUR AREA SATURDAY NIGHT...THUS ALLOWING FOR
NORTHWESTERLY UPPER TROPOSPHERIC FLOW OVER OUR AREA AS WE HEAD
INTO THE EARLY PART OF NEXT WEEK.
GUIDANCE SUGGESTS AN OVERALL LACK IN OMEGA WILL KEEP US DRY
THURSDAY...THURSDAY NIGHT AND THROUGH THE DAY FRIDAY...AND SUCH
HAS BEEN PRESENTED IN THE OFFICIAL FORECAST.
STARTING FRIDAY NIGHT AND CONTINUING INTO SATURDAY...SATURDAY
NIGHT AND PERHAPS EARLY SUNDAY...UPPER TROPOSPHERIC THERMAL
ADVECTION AHEAD OF THE APPROACHING TROUGH AXIS IS EXPECTED TO
PROMOTE ENOUGH OMEGA FOR PRECIPITATION PRODUCTION ACROSS MUCH OF
THE REGION...INCLUDING OUR CWA. THE OPERATIONAL GFS AND EC
CONTINUE TO COME INTO BETTER AGREEMENT BY SUGGESTING PRECIPITATION
WILL MOVE IN FROM SOUTHWEST TO NORTHEAST ACROSS MUCH OF OUR
AREA...AGAIN BEGINNING FRIDAY NIGHT...WITH WIDESPREAD
PRECIPITATION THEN CONTINUING ACROSS THE AREA SATURDAY AND
SATURDAY NIGHT BEFORE MOVING EAST...ALONG THE UPPER TROPOSPHERIC
TROUGH AXIS...AROUND OR SHORTLY AFTER SUNRISE SUNDAY. INTERESTING
TO NOTE THAT THE NAM...WHICH THROUGH 84 HOURS IS JUST NOW UP TO
12Z SATURDAY...APPEARS TO KEEP THE PRIMARY AXIS OF OMEGA WELL TO
OUR SOUTHEAST AND AS A RESULT...KEEPS US DRY THROUGH 12Z SATURDAY.
ALTHOUGH IT WILL BE VERY INTERESTING TO SEE HOW THE NAM UNFOLDS
THROUGH THE NEXT FEW RUNS...GIVEN THE AFOREMENTIONED DATA FROM
THE OPERATIONAL GFS AND EC...IT SEEMS PRUDENT TO PRESENT YET
ANOTHER INCREASE IN POPS FOR THIS WEEKEND AND 30-60% POPS ARE NOW
SHOWN IN THE OFFICIAL FORECAST...WITH THE HIGHEST POPS RELEGATED
TO OUR SOUTHEAST WHICH IS WHERE GUIDANCE SUGGESTS THE STRONGEST
OMEGA AND MOST EFFICIENT PRECIPITATION PRODUCTION WILL RESIDE
DURING THIS UPCOMING STORM SYSTEM.
ONCE PRECIPITATION COMES TO AN END ON SUNDAY...GUIDANCE SUGGESTS
DRY CONDITIONS SHOULD BE OBSERVED SUNDAY NIGHT THROUGH
TUESDAY...AND SUCH HAS BEEN PRESENTED IN THE OFFICIAL FORECAST.
ALTHOUGH IT APPEARS PRECIPITATION COULD START OUT AS RAIN FRIDAY
NIGHT...FORECAST PROXIMITY SOUNDINGS FROM ACROSS THE CWA...PER THE
OPERATIONAL GFS AND EC...SUGGEST THE LOWER TROPOSPHERE WILL BE
SUPPORTIVE FOR SNOWFALL AT THE SURFACE BY 12Z SATURDAY AND
CONTINUING INTO SUNDAY. THAT SAID...WITH A CONTINUED
SOUTH/SOUTHEASTERLY BOUNDARY- LAYER WIND FIELD EXPECTED THROUGH
THE DAY SATURDAY...THERE IS STILL AT LEAST AN OPPORTUNITY FOR SOME
TEMPERATURE RECOVERY NEAR THE SURFACE DURING THE DAY SATURDAY AND
SUPERBLEND RESPONDED BY PROVIDING SATURDAY HIGHS IN THE UPPER 30S
AND LOW 40S. THERE ARE SUGGESTIONS FROM MULTIPLE SETS OF GUIDANCE
THAT THIS TEMPERATURE FORECAST FOR SATURDAY IS TOO HIGH AND NEEDS
TO BE REDUCED BY 4-5 DEGREES. WENT AHEAD WITH A ~2 DEGREE DECREASE
FROM THE SUPERBLEND SOLUTION FOR SATURDAY HIGHS TO ACCOUNT OF
THIS...BUT EVEN NOW THE OFFICIAL FORECAST CALLS FOR SATURDAY
TEMPERATURE READINGS IN THE UPPER 30S FOR MOST LOCATIONS AND GIVEN
THIS...DESPITE FORECAST PROXIMITY SOUNDINGS FROM THE OPERATIONAL
GFS AND EC SUGGESTING SNOWFALL WILL BE THE PRIMARY PRECIPITATION
TYPE DURING THE DAY SATURDAY...FIND IT HARD TO JUSTIFY AN ALL-SNOW
FORECAST WITH SURFACE TEMPERATURE READINGS SO HIGH. AS A
RESULT...OPTED TO GO WITH A RAIN AND SNOW MIX DURING THE DAY
SATURDAY...WITH ALL SNOW THEN EXPECTED SATURDAY NIGHT INTO SUNDAY
AS DIABATIC HEATING IS LOST AND A BOUNDARY-LAYER BAROCLINIC ZONE
CLEARS THE AREA. OBVIOUSLY THE TEMPERATURE FORECAST FOR SATURDAY
WILL NEED TO BE CLOSELY MONITORED AS ANY MORE OF A DECREASE IN
SATURDAYS TEMPERATURE FORECAST WOULD SUGGEST MORE SNOW THAN RAIN
DURING THE DAY SATURDAY...AND MORE IN THE WAY OF SNOW
ACCUMULATION.
OBVIOUSLY STORM-TOTAL SNOWFALL ACCUMULATION WILL BE HEAVILY
DEPENDENT UPON HOW MUCH SNOWFALL IS REALIZED DURING THE DAY
SATURDAY...AND GIVEN THE UNCERTAINTY WITH RESPECT TO PRECIPITATION
TYPE AND RESULTANT SNOW ACCUMULATION DURING THE DAY
SATURDAY...IT STILL REMAINS TOO EARLY TO GET SPECIFIC ON SNOW
AMOUNTS IN THE OFFICIAL FORECAST. THAT SAID...ONCE AGAIN TAKING
THE OPERATIONAL GFS AND EC AT FACE VALUE SUGGESTS ADVISORY-WORTHY
ACCUMULATION OF ~3 INCHES COULD BE REALIZED ACROSS PORTIONS OF THE
CWA SATURDAY NIGHT INTO EARLY SUNDAY MORNING ALONE...DESPITE WHAT
HAPPENS DURING THE DAY SATURDAY. IN ADDITION...GUIDANCE IS NOW
SUGGESTING THAT AN INCREASING PRESSURE GRADIENT POST-FROPA
SATURDAY NIGHT INTO SUNDAY WILL PROMOTE A STRONG WIND...SUSTAINED
AT AROUND 18KTS WITH HIGHER GUSTS. THIS WIND...WORKING IN CONCERT
WITH THE SNOWFALL...WOULD LIKELY CREATE AT LEAST PERIODIC
VISIBILITY RESTRICTION IN BLOWING SNOW. SO...GIVEN THE FACT THAT
WE NOW HAVE "LIKELY" POPS IN THE FORECAST FOR PORTIONS OF THE AREA
THIS WEEKEND...AND THE FACT THAT IT NOW APPEARS WE HAVE AN
OPPORTUNITY FOR BLOWING SNOW AND VISIBILITY RESTRICTION...FEEL IT
PRUDENT TO INTRODUCE A MENTION OF ACCUMULATING SNOWFALL AND
VISIBILITY RESTRICTION DUE TO BLOWING SNOW FOR THIS WEEKEND IN THE
HWO.
FINALLY...HIGHS TO START THE LONG-TERM FORECAST PERIOD ON THURSDAY
AND FRIDAY ARE STILL EXPECTED TO CLIMB INTO THE 40S...BUT WILL
FALL INTO THE 20S POST-FROPA STARTING EARLY NEXT WEEK. OVERNIGHT
LOWS IN THE 20S AND 30S ARE ALSO EXPECTED TO START THE LONG-TERM
FORECAST PERIOD...BUT THESE READINGS WILL LIKELY FALL INTO THE
SINGLE DIGITS AND TEENS EARLY NEXT WEEK AS WELL.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1056 AM CST WED JAN 28 2015
THE MAIN ISSUE FOR THE TAF PERIOD WILL BE INCREASING NORTHWEST
WINDS. FOLLOWING THE PASSAGE OF A TROUGH AXIS THIS
AFTN...NORTHWEST WINDS WILL MIX DOWN WITH WIND GUSTS AROUND 30 MPH
POSSIBLE. EVEN STRONGER WINDS ARE FORECAST TONIGHT IN A TIGHTENING
PRESSURE GRADIENT IN BETWEEN AN EXITING SFC LOW AND A BUILDING SFC
RIDGE. NORTHWEST WIND GUSTS NEAR 40KTS ARE POSSIBLE THRU THE
OVERNIGHT HOURS. WIND SPEEDS WILL SUBSIDE JUST BEYOND THE TAF
PERIOD. CIGS MAY DROP TO MVFR.
&&
.FIRE WEATHER...
ISSUED AT 344 AM CST WED JAN 28 2015
GUSTY W/NW WINDS ARE EXPECTED TO DEVELOP ACROSS THE CWA DURING THE
DAYTIME HOURS TODAY...AND ABOVE AVERAGE TEMPERATURES ARE ONCE
AGAIN FORECAST. HIGH TEMPERATURES REACHING WELL INTO THE 60S TO
NEAR 70 DEGREES IN SOME LOCATIONS...COMBINED WITH DEWPOINTS
FORECAST TO FALL TO NEAR 30 DEGREES WILL RESULT IN NEAR CRITICAL
FIRE WEATHER CONDITIONS ACROSS PORTIONS OF THE CWA. THE BEST
CHANCE FOR RELATIVE HUMIDITY VALUES TO FALL INTO THE 20 TO 25 MPH
RANGE WITH THOSE GUSTY WINDS WILL LIE ACROSS AREAS GENERALLY
ALONG AND WEST OF A LEXINGTON NEB TO BELOIT KS LINE.
&&
.CLIMATE...
ISSUED AT 331 AM CST TUE JAN 27 2015
YET ANOTHER DAY WITH FORECAST HIGHS WELL ABOVE AVERAGE IS EXPECTED
TODAY. AVERAGE HIGHS FOR THIS TIME OF YEAR ARE MAINLY IN THE MID
30S...WITH HIGHS FORECAST TODAY TO REACH INTO THE 60S /NEAR 70
POSSIBLE ACROSS SRN LOCATIONS/. HERE IS THE RECORD HIGH
TEMPERATURE INFORMATION FOR TODAY...WITH GRAND ISLAND CURRENTLY
FORECAST TO BREAK THAT RECORD...BUT HASTINGS FORECAST TO FALL A
BIT SHORT.
GRAND ISLAND: RECORD IS 63 DEGREES IN 1986. FORECAST HIGH: 65
HASTINGS: RECORD IS 69 DEGREES IN 1931. FORECAST HIGH: 65
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...ADP
LONG TERM...BRYANT
AVIATION...FAY
FIRE WEATHER...ADP
CLIMATE...ADP
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1237 PM CST WED JAN 28 2015
.UPDATE...
ISSUED AT 1227 PM CST WED JAN 28 2015
ALLOWED THE DENSE FOG ADVISORY TO EXPIRE ACROSS THE NORTH AND EAST
AS VISIBILITIES HAVE CONSISTENTLY IMPROVED. HAVE LEFT AREAS OF FOG
IN THE FORECAST FOR PORTIONS OF THE NORTH CENTRAL AND JAMES RIVER
VALLEY...WITH PATCHY MENTIONS CENTRAL AND NORTHWEST.
INCREASED WINDS A BIT IN THE SOUTHWEST...BUT FOR NOW WILL HOLD OFF
ON ANY WIND ADVISORY AS CRITERIA IS BORDERLINE AND THE HIGHEST
WIND SPEEDS DO NOT LAST ALL THAT LONG.
UPDATE ISSUED AT 1018 AM CST WED JAN 28 2015
UPDATED THE FORECAST FOR PATCHY FREEZING DRIZZLE ACROSS THE NORTH
THROUGH 00 UTC. PROFILES SHOW A SATURATED LOWER LEVEL AND WITH
MOST OF THE MORNING AND AFTERNOON BELOW FREEZING ACROSS THE NORTH
DO EXPECT TO SEE SOME LIGHT FREEZING DRIZZLE.
UPDATE ISSUED AT 630 AM CST WED JAN 28 2015
NO UPDATES OTHER THAN TO UPDATE TEMPERATURES BASED ON LATEST 6 AM
OBSERVATIONS.
UPDATE
ISSUED AT 546 AM CST WED JAN 28 2015
BASED ON TRENDS VIA OBSERVATIONS AND SATELLITE IMAGERY...WILL LEAN
ON HRRR GUIDANCE (WHICH IS DOING VERY WELL) AND EXPAND FOG
WORDING WEST AND SOUTH AND WILL ALSO EXPAND THE DENSE FOG ADVISORY
FARTHER WEST. ALSO EXTENDED TILL 18Z FOR HEADLINE CUTOFF.
UPDATE
ISSUED AT 344 AM CST WED JAN 28 2015
WILL GO WITH A DENSE FOG ADVISORY EAST. OBSERVATIONS NOT GETTING
ANY BETTER AND AREA WEB CAMS SHOWING WORSE VISIBILITIES NOW.
UPDATED PRODUCTS OUT SOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 312 AM CST WED JAN 28 2015
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE COOLER
TEMPERATURES...BREEZY CONDITIONS...AND CHANCES FOR LIGHT SNOW
TODAY AND TONIGHT.
CURRENTLY...ZONAL FLOW ALOFT WITH THE UPPER LEVEL RIDGE FLATTENING
ACROSS THE GREAT PLAINS IN RESPONSE TO SOUTHERN AND NORTHERN
STREAM S/WV`S CROSSING THE ROCKIES. SURFACE LOW PRESSURE
ASSOCIATED WITH THE SOUTHERN STREAM WAVE MOVING SOUTHEAST ACROSS
SOUTHWEST NORTH DAKOTA INTO CENTRAL SOUTH DAKOTA.
SOUTH/SOUTHEASTERLY RETURN FLOW AHEAD OF THE LOW HAS MAINTAINED
LOW STRATUS AND/OR FOG ACROSS EASTERN NORTH DAKOTA SINCE YESTERDAY
EVENING. LARGE STRATUS FIELD WRAPS BACK WESTWARD ACROSS SOUTH
CENTRAL CANADA WITH THE SOUTHERN EDGE OF THE STRATUS ALONG TO
SLIGHTLY NORTH OF THE INTERNATIONAL BORDER. VISIBILITIES CONTINUE
TO FLUCTUATE ACROSS MY EAST...AND WILL HANDLE THE PATCHY DENSE FOG
WITH THE CURRENT SPECIAL WEATHER STATEMENT.
AS THE SURFACE LOW CONTINUES SOUTHEAST TODAY...SURFACE WINDS
BECOME MORE NORTHWESTERLY AND INCREASE THROUGH THE MORNING INTO
THE AFTERNOON BEHIND A STRONG SFC COLD FRONT. BUFKIT ANALYSIS
BRINGS 35 TO NEAR 40KTS WITHIN THE TOP OF THE MIXED LAYER TO MOST
SITES...SO WHILE BREEZY...SUB-ADVISORY MAGNITUDES. THUS NO
HEADLINES WITH THIS FORECAST ISSUANCE. STRATUS TO OUR NORTH SURGES
SOUTH ALONG WITH CAA WITH MOST OF REGION CLOUDED OVER BY EARLY TO
MID AFTERNOON. CLOUD COVER AND BREEZY CONDITIONS WILL THEN
CONTINUE INTO WEDNESDAY NIGHT. POST FRONTAL SNOW SHOWERS DEVELOP
LATER THIS MORNING NORTH THEN SOUTHWARD THIS AFTERNOON CONTINUING
TONIGHT. KEPT POPS AT SLIGHT CHANCE FOR NOW...BUT MAY NEED TO BE
INCREASED.
FOR TEMPERATURES...DESPITE CAA AND CLOUD COVER...THE INCREASED
MIXING WITH THE BREEZY NORTHWEST WIND WILL ACTUALLY KEEP
TEMPERATURES FROM BOTTOMING OUT TOO MUCH TODAY. DAYTIME HIGHS
WILL BE COOLER THAN TUESDAY...RANGING FROM THE LOW 30S NORTH TO
MID/UPPER 40S SOUTHWEST. SO ABOUT 5-15 DEGREES COOLER. CLOUD COVER
AND CONTINUED MIXING TONIGHT SHOULD ALSO KEEP LOWS FROM DROPPING
TOO MUCH.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 315 AM CST WED JAN 28 2015
CHANCES FOR SNOW SATURDAY AND COOLER TEMPERATURES THROUGH THE
WEEKEND AND INTO NEXT WEEK WILL HIGHLIGHT THE LONG TERM.
AN UPPER LEVEL TROUGH MOVING SOUTHEAST FROM ALBERTA LATE FRIDAY INTO
EARLY SATURDAY MORNING WILL BRING A CHANCE OF SNOW THROUGH
SATURDAY NIGHT...ALONG WITH COLDER TEMPERATURES. THERE IS GOOD
AGREEMENT BETWEEN THE GFS/ECMWF IN THE OVERALL TIMING/LOCATION OF
THE UPPER LEVEL TROUGH. THE GLOBAL GEM IS AN OUTLIER AND WILL USE
A GFS/EC SOLUTION. THIS BRINGS THE BEST CHANCES OF LIGHT SNOW
ACCUMULATIONS MAINLY ALONG AND WEST OF THE HIGHWAY 83 CORRIDOR.
SNOW GROWTH ZONE BECOMES RATHER DEEP BY 00 UTC SUNDAY BUT OMEGA
WITHIN THE ZONE IS LIMITED. BUT WITH SNOW RATIOS INCREASING AS THE
COLD AIR FILTERS IN...THINK ONE OR TWO INCH ACCUMULATIONS ARE
POSSIBLE SATURDAY THROUGH SATURDAY NIGHT OVER THE WESTERN HALF OF
NORTH DAKOTA. A NORTHEAST SURFACE FLOW OF 10 TO 20 MPH COULD YIELD
SOME REDUCED VISIBILITIES IN FALLING SNOW...BUT SIGNIFICANT
BLOWING AND DRIFTING IS NOT EXPECTED AT THIS TIME. THE REMAINDER
OF THE FORECAST PERIOD BRINGS BELOW AVERAGE TEMPERATURES AND ONLY
MINIMAL PRECIPITATION CHANCES AHEAD OF EACH REINFORCING SHOT OF
COLD AIR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1227 PM CST WED JAN 28 2015
FOG AND CEILINGS HAVE IMPROVED AT SITES KISN...KMOT...AND KJMS AND
ARE EXPECTED TO CONTINUE TO IMPROVE THROUGH THE AFTERNOON.
HOWEVER...CONDITIONS ARE EXPECTED TO REMAIN LIFR TO IFR. FOR KBIS AND
KDIK LOWER CEILINGS WILL MOVE IN THROUGH THE AFTERNOON FOR IFR CONDITIONS. TOOK
OUT THE MENTION OF SNOW FROM TAFS AS PRECIP TYPE WILL MORE LIKELY
BE FREEZING DRIZZLE OR SIMPLY DRIZZLE...HOWEVER IT WILL BE VERY
LIGHT AND PATCHY ACROSS THE REGION THUS HAVE OPTED TO GO WITH BR
IN THE TAFS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MM
SHORT TERM...NH
LONG TERM...TWH
AVIATION...MM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1024 AM CST WED JAN 28 2015
.UPDATE...
ISSUED AT 1018 AM CST WED JAN 28 2015
UPDATED THE FORECAST FOR PATCHY FREEZING DRIZZLE ACROSS THE NORTH
THROUGH 00 UTC. PROFILES SHOW A SATURATED LOWER LEVEL AND WITH
MOST OF THE MORNING AND AFTERNOON BELOW FREEZING ACROSS THE NORTH
DO EXPECT TO SEE SOME LIGHT FREEZING DRIZZLE.
UPDATE ISSUED AT 630 AM CST WED JAN 28 2015
NO UPDATES OTHER THAN TO UPDATE TEMPERATURES BASED ON LATEST 6 AM
OBSERVATIONS.
UPDATE
ISSUED AT 546 AM CST WED JAN 28 2015
BASED ON TRENDS VIA OBSERVATIONS AND SATELLITE IMAGERY...WILL LEAN
ON HRRR GUIDANCE (WHICH IS DOING VERY WELL) AND EXPAND FOG
WORDING WEST AND SOUTH AND WILL ALSO EXPAND THE DENSE FOG ADVISORY
FARTHER WEST. ALSO EXTENDED TILL 18Z FOR HEADLINE CUTOFF.
UPDATE
ISSUED AT 344 AM CST WED JAN 28 2015
WILL GO WITH A DENSE FOG ADVISORY EAST. OBSERVATIONS NOT GETTING
ANY BETTER AND AREA WEB CAMS SHOWING WORSE VISIBILITIES NOW.
UPDATED PRODUCTS OUT SOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 312 AM CST WED JAN 28 2015
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE COOLER
TEMPERATURES...BREEZY CONDITIONS...AND CHANCES FOR LIGHT SNOW
TODAY AND TONIGHT.
CURRENTLY...ZONAL FLOW ALOFT WITH THE UPPER LEVEL RIDGE FLATTENING
ACROSS THE GREAT PLAINS IN RESPONSE TO SOUTHERN AND NORTHERN
STREAM S/WV`S CROSSING THE ROCKIES. SURFACE LOW PRESSURE
ASSOCIATED WITH THE SOUTHERN STREAM WAVE MOVING SOUTHEAST ACROSS
SOUTHWEST NORTH DAKOTA INTO CENTRAL SOUTH DAKOTA.
SOUTH/SOUTHEASTERLY RETURN FLOW AHEAD OF THE LOW HAS MAINTAINED
LOW STRATUS AND/OR FOG ACROSS EASTERN NORTH DAKOTA SINCE YESTERDAY
EVENING. LARGE STRATUS FIELD WRAPS BACK WESTWARD ACROSS SOUTH
CENTRAL CANADA WITH THE SOUTHERN EDGE OF THE STRATUS ALONG TO
SLIGHTLY NORTH OF THE INTERNATIONAL BORDER. VISIBILITIES CONTINUE
TO FLUCTUATE ACROSS MY EAST...AND WILL HANDLE THE PATCHY DENSE FOG
WITH THE CURRENT SPECIAL WEATHER STATEMENT.
AS THE SURFACE LOW CONTINUES SOUTHEAST TODAY...SURFACE WINDS
BECOME MORE NORTHWESTERLY AND INCREASE THROUGH THE MORNING INTO
THE AFTERNOON BEHIND A STRONG SFC COLD FRONT. BUFKIT ANALYSIS
BRINGS 35 TO NEAR 40KTS WITHIN THE TOP OF THE MIXED LAYER TO MOST
SITES...SO WHILE BREEZY...SUB-ADVISORY MAGNITUDES. THUS NO
HEADLINES WITH THIS FORECAST ISSUANCE. STRATUS TO OUR NORTH SURGES
SOUTH ALONG WITH CAA WITH MOST OF REGION CLOUDED OVER BY EARLY TO
MID AFTERNOON. CLOUD COVER AND BREEZY CONDITIONS WILL THEN
CONTINUE INTO WEDNESDAY NIGHT. POST FRONTAL SNOW SHOWERS DEVELOP
LATER THIS MORNING NORTH THEN SOUTHWARD THIS AFTERNOON CONTINUING
TONIGHT. KEPT POPS AT SLIGHT CHANCE FOR NOW...BUT MAY NEED TO BE
INCREASED.
FOR TEMPERATURES...DESPITE CAA AND CLOUD COVER...THE INCREASED
MIXING WITH THE BREEZY NORTHWEST WIND WILL ACTUALLY KEEP
TEMPERATURES FROM BOTTOMING OUT TOO MUCH TODAY. DAYTIME HIGHS
WILL BE COOLER THAN TUESDAY...RANGING FROM THE LOW 30S NORTH TO
MID/UPPER 40S SOUTHWEST. SO ABOUT 5-15 DEGREES COOLER. CLOUD COVER
AND CONTINUED MIXING TONIGHT SHOULD ALSO KEEP LOWS FROM DROPPING
TOO MUCH.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 315 AM CST WED JAN 28 2015
CHANCES FOR SNOW SATURDAY AND COOLER TEMPERATURES THROUGH THE
WEEKEND AND INTO NEXT WEEK WILL HIGHLIGHT THE LONG TERM.
AN UPPER LEVEL TROUGH MOVING SOUTHEAST FROM ALBERTA LATE FRIDAY INTO
EARLY SATURDAY MORNING WILL BRING A CHANCE OF SNOW THROUGH
SATURDAY NIGHT...ALONG WITH COLDER TEMPERATURES. THERE IS GOOD
AGREEMENT BETWEEN THE GFS/ECMWF IN THE OVERALL TIMING/LOCATION OF
THE UPPER LEVEL TROUGH. THE GLOBAL GEM IS AN OUTLIER AND WILL USE
A GFS/EC SOLUTION. THIS BRINGS THE BEST CHANCES OF LIGHT SNOW
ACCUMULATIONS MAINLY ALONG AND WEST OF THE HIGHWAY 83 CORRIDOR.
SNOW GROWTH ZONE BECOMES RATHER DEEP BY 00 UTC SUNDAY BUT OMEGA
WITHIN THE ZONE IS LIMITED. BUT WITH SNOW RATIOS INCREASING AS THE
COLD AIR FILTERS IN...THINK ONE OR TWO INCH ACCUMULATIONS ARE
POSSIBLE SATURDAY THROUGH SATURDAY NIGHT OVER THE WESTERN HALF OF
NORTH DAKOTA. A NORTHEAST SURFACE FLOW OF 10 TO 20 MPH COULD YIELD
SOME REDUCED VISIBILITIES IN FALLING SNOW...BUT SIGNIFICANT
BLOWING AND DRIFTING IS NOT EXPECTED AT THIS TIME. THE REMAINDER
OF THE FORECAST PERIOD BRINGS BELOW AVERAGE TEMPERATURES AND ONLY
MINIMAL PRECIPITATION CHANCES AHEAD OF EACH REINFORCING SHOT OF
COLD AIR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 630 AM CST WED JAN 28 2015
WIDESPREAD VLIFR CIGS WILL IMPACT ALL TERMINALS BY EARLY TODAY AS
LOW STRATUS AND FOG EXPAND SOUTH AND WEST ACROSS NORTH DAKOTA. LOW
STRATUS WILL THEN HOLD ON THROUGH WEDNESDAY NIGHT BUT WILL LIFT TO
LIFR/IFR MOST AREAS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR NDZ002>005-010>013-
021>023-025-036-037.
&&
$$
UPDATE...MM
SHORT TERM...NH
LONG TERM...TWH
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1151 AM CST WED JAN 28 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM CST WED JAN 28 2015
TRICKY TEMPERATURE FORECAST TODAY...WHICH WILL BE LARGELY DEPENDENT
ON THE EXTENT OF CLOUD COVERAGE. VERY MILD 925 MB TEMPERATURES ABOVE
ZERO AND SOUTHERLY WINDS AT THE SURFACE WILL TAP INTO SOME CONTINUED
SEASONABLY WARM TEMPERATURES. THE QUESTION IS HOW MUCH CLOUD COVER
WILL IMPACT WARMING TODAY. THE MOST RECENT HRRR HAS A GOOD HANDLE ON
CLOUDS EARLY THIS MORNING...WHICH WILL SHIFT EASTWARD INTO THE
MIDDAY HOURS. THINK THE THE NORTHEASTERN HALF OF THE FORECAST
AREA...FROM EAST CENTRAL SD INTO SOUTHWEST MN AND THE IOWA GREAT
LAKES ARE WILL HOLD ONTO MOSTLY CLOUDY SKIES THE BULK OF THE DAY.
KEPT TEMPERATURES ON THE CONSERVATIVE SIDE OF GUIDANCE IN THIS AREA.
IF CLOUDS LOOK LESS ABUNDANT...COULD SEE READINGS WARM ABOVE
FORECAST HIGHS. ELSEWHERE...MOSTLY SUNNY TO PARTLY CLOUDY SKIES
THROUGH MID AFTERNOON WILL GIVE WAY TO CLOUDS WITH THE ANTICIPATED
FRONTAL PASSAGE LATE AFTERNOON. SOUTH CENTRAL SD INTO THE MISSOURI
VALLEY WILL HAVE THE BEST POTENTIAL TO WARM INTO THE LOW TO MID 50S.
WITH THE FRONT TRACKING THROUGH THE AREA MID AFTERNOON INTO THIS
EVENING...CLOUDS WILL ROLL BACK INTO THE REGION. NORTHWEST WINDS
EXPECTED TO BECOME QUITE WINDY BEHIND THE FRONT WITH 40 TO 50 KT
WINDS JUST OFF THE SURFACE. AT THE SURFACE...WINDS WILL LIKELY BE
NEAR ADVISORY LEVEL...ESPECIALLY WITH GUSTS AROUND 40 OR 45 MPH.
GIVEN THAT THE STRONGEST WINDS ARE EXPECTED IN THE EARLY MORNING
HOURS AND ARE MARGINAL FOR AN ADVISORY...WILL HOLD OFF ISSUING ANY
HEADLINES FOR NOW.
WITH LOW LEVEL STRATUS BLANKETING THE AREA OVERNIGHT...A FAST MOVING
SHORTWAVE DROPS ACROSS SOUTHWEST MINNESOTA LATE EVENING INTO THE
EARLY MORNING HOURS. NOT MUCH MOISTURE IN PLACE...AND WHILE THE LOW
STRATUS DOES THICKEN...THE CLOUD MASS REMAINS LARGELY OUTSIDE THE
SNOW GROWTH ZONE. COULD SEE A FEW SNOW ISOLATED SHOWERS DEVELOP
MAINLY IN OUR MN COUNTIES...WITH SOME PATCH DRIZZLE ALSO POSSIBLE.
SURFACE TEMPERATURES WILL BE NEAR OR JUST ABOVE FREEZING IN THIS
AREA.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 316 AM CST WED JAN 28 2015
THE SHORTWAVE EXITS THE AREA ON THURSDAY WITH SURFACE HIGH PRESSURE
BUILDING INTO THE REGION. IT WILL BE BREEZY WITH A TIGHT GRADIENT
ACROSS THE AREA AND GOOD MIXING IN A COLD AIR ADVECTION REGIME. IN
RESPONSE TO THE COLDER AIR FILTERING INTO THE REGION BEHIND THE
EXITING SHORTWAVE...HIGH TEMPERATURES WILL BE A GOOD 10 TO 15
DEGREES COOLER THAN TODAY...TOPPING OUT IN THE UPPER 20S FROM EAST
CENTRAL SD THROUGH SOUTHWESTERN MN...TO UPPER 30S THROUGH THE MO
RIVER CORRIDOR. WINDS WILL DIE OFF ON THURSDAY NIGHT...LEADING TO A
COLD NIGHT WITH LOWS IN THE LOWER/MID TEENS THROUGH THE EASTERN TWO
THIRDS OF THE CWA. TO THE WEST...IT WILL NOT BE QUITE AS COLD WITH
AN ENSUING SOUTHEASTERLY FLOW BEHIND THE EXITING HIGH
PRESSURE...WITH LOWS GENERALLY LOWER 20S. FRIDAY WILL SEE WARMING
WITH A STRENGTHENING SOUTHERLY FLOW ON THE BACKSIDE OF THE HIGH.
HIGH TEMPERATURES WILL RUN LOWER 30S NORTHEAST TO AS WARM AS THE MID
40S THROUGH SOUTH CENTRAL SD.
ON SATURDAY NORTHERN STREAM UPPER LEVEL ENERGY DROPS OUT OF WESTERN
CANADA AND SLIDES SOUTHWARD AS SOUTHERN STREAM ENERGY LIFTS TO THE
NORTH...CONVERGING OVER THE CENTRAL PLAINS. STILL SOME MODEL
DIFFERENCES ON HOW THIS SCENARIO EVOLVES...BUT DOES POTENTIALLY
BRING PRECIPITATION TO AT LEAST OUR SOUTHERN AND EASTERN CWA FOR
LATER ON SATURDAY AFTERNOON AND SATURDAY NIGHT. PRECIPITATION TYPE
LOOKS TO BE MAINLY IN THE FORM OF SNOW...WITH COOLING THERMAL
PROFILES AS LOW PRESSURE OVER THE JAMES BAY BEGINS TO DRIVE COLDER
AIR SOUTHWARD. AT THIS POINT SNOWFALL AMOUNTS LOOK TO BE IN THE
RANGE OF 2 TO 3 INCHES IN OUR SOUTHEAST...THOUGH WILL HAVE TO WATCH
THE TRACK OF THIS SYSTEM FOR GREATER SNOWFALL AMOUNTS IF IT TRENDS
FARTHER TO THE NORTH. IT STILL WONT BE UNREASONABLY COLD ON SATURDAY
WITH HIGHS MAINLY IN THE 30S...BUT BY SATURDAY NIGHT AND SUNDAY MUCH
COLDER AIR WILL HAVE SETTLED INTO THE REGION WITH HIGHS ON SUNDAY
MOSTLY IN THE TEENS. THE COLD AIR THEN LOOKS TO LINGER THROUGH NEXT
MONDAY...WITH SOME MODERATION POSSIBLE BY TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1139 AM CST WED JAN 28 2015
COLD FRONT MOVING THROUGH THE AREA THIS AFTERNOON WITH GUSTY
NORTHWEST WINDS BEHIND THE FRONT. WILL ALSO HAVE MVFR
STRATUS...WITH THE CHANCE FOR SOME LIGHT DRIZZLE/FREEZING DRIZZLE
ACROSS SOUTHWEST MINNESOTA AFTER 03Z -15ZISH THURSDAY MORNING.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...
LONG TERM...JM
AVIATION...
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
328 PM CST WED JAN 28 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 328 PM CST WED JAN 28 2015
AT 3 PM...SURFACE LOWS WERE LOCATED OVER NORTHEAST NEBRASKA AND
WEST OF HUDSON BAY. IN BETWEEN THESE 2 LOW PRESSURE SYSTEMS...
A TROUGH EXTENDED SOUTH ACROSS THE EASTERN DAKOTAS. LIKE THE
28.00Z AND 28.06Z MODELS...THE 28.12Z MODELS SHOW THAT THIS TROUGH
WILL MOVE EAST TONIGHT. AS IT APPROACHES...MODERATE TO STRONG
925 MB MOISTURE TRANSPORT DEVELOPS AHEAD OF IT ACROSS NORTHEAST
IOWA AND SOUTHEAST MINNESOTA THIS EVENING AND WESTERN WISCONSIN
TONIGHT. THIS WILL AID IN MOISTENING THE AIR MASS BELOW 800 MB.
SOUNDINGS GENERALLY SHOW THAT THERE IS NO INTRODUCTION OF ICE FROM
ALOFT...THUS KEEPING THE PRECIPITATION IN FORM OF SUPER COOLED
WATER DROPLETS. THERE WERE A FEW -8C SHOWING AT TIMES...SO TOTALLY
CANNOT RULE OUT MAYBE A BIT OF SNOW...BUT NOT ENOUGH TO
ACCUMULATE. WITH THE PRECIPITATION BEING DRIZZLE...THE MAIN
QUESTION WILL BE HOW COLD WILL BE THE SURFACE TEMPERATURES.
FILTERED SUNSHINE SOUTH OF INTERSTATE 90 HAS ALLOWED SURFACE
TEMPERATURES TO WARM INTO THE LOWER AND MID 30S...AND PAVEMENT
TEMPERATURES TO AROUND 40 DEGREES. WITH THE LOSS OF SUNSHINE...THE
PAVEMENT TEMPERATURES WILL QUICKLY FALL. HOWEVER THE SOUTHERLY
WINDS WILL LIKELY KEEP THE TEMPERATURES AT OR ABOVE FREEZING WEST
AND SOUTH OF INTERSTATE 94. AS A RESULT...THE FREEZING DRIZZLE
THREAT THERE LOOKS TO BE SCATTERED. MEANWHILE NORTH AND EAST OF
INTERSTATE 94 SURFACE TEMPERATURES HAVE BEEN SLOW TO WARM. THIS IS
DUE TO THE SOUTHEAST WINDS BLOWING OVER THE SNOW PACK. WITH
TEMPERATURES ALREADY BELOW FREEZING DECIDED TO ISSUE A FREEZING
RAIN ADVISORY FROM 9 AM TO 6 AM FOR THESE AREAS. ONLY A LIGHT
GLAZE IS EXPECTED TO DEVELOP ON UNTREATED ROADS AND SURFACES.
ON THURSDAY MORNING...THE MODELS SHOW THAT A SECOND SHORT WAVE
WILL MOVE QUICKLY EAST ACROSS THE AREA. WITH SOME MODERATE COLD
AIR ADVECTION IN THE WAKE OF THIS TROUGH...THE TEMPERATURES WILL
COOL ENOUGH FOR THERE TO BE A MIX OF LIGHT SNOW AND FREEZING
DRIZZLE/DRIZZLE. LITTLE...IF ANY...ACCUMULATION IS EXPECTED. ALSO
WITH THE SOUNDINGS SHOWING MOISTURE TRAPPED BELOW THE SUBSIDENCE
INVERSION...THE CLOUDS WILL LINGER THROUGH THE MORNING AND SLOWLY
ERODE DURING THE EVENING AS DRIER AIR ADVECTS INTO THE REGION.
FOR THE ENTIRE DAY THURSDAY...THE MODELS SHOW VERY STEEP LOW LEVEL
LAPSE RATES BETWEEN 950 AND 900 MB. THIS WILL ALLOW THE NORTHWEST
WINDS TO GUST INTO THE 25 TO 30 MPH RANGE ACROSS WESTERN
WISCONSIN...AND INTO THE 30 TO 35 MPH RANGE IN SOUTHEAST MINNESOTA
AND NORTHEAST IOWA.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 328 PM CST WED JAN 28 2015
ON FRIDAY NIGHT...A CANADIAN COLD FRONT WILL MOVE QUICKLY
SOUTHEAST ACROSS THE AREA. THE NAM SHOWS THAT THERE WILL BE ENOUGH
SATURATION FOR SOME LIGHT SNOW. MEANWHILE THE OTHER MODELS SHOW
THAT THE BEST LIFT AND SATURATION WILL REMAIN ACROSS NORTHERN
MINNESOTA...NORTHERN WISCONSIN...AND UPPER MICHIGAN. WITH THE
MODEL CONSENSUS...KEPT THE FORECAST DRY FOR NOW.
FROM SATURDAY AFTERNOON INTO SUNDAY...THE MODELS ARE NOW SHOWING
THAT THE SHORT WAVE FROM FRIDAY NIGHT WILL PUSH THE FRONT FAR
ENOUGH SOUTH THAT MUCH OF THE SNOW ASSOCIATED WITH THIS SYSTEM
WILL REMAIN SOUTH AND WEST OF THE FORECAST AREA. THE ONLY MODEL
STILL SHOWING ADVISORY SNOW IS THE GEM. BOTH THE GFS AND ECMWF
HAVE SIGNIFICANTLY SHIFTED MUCH OF THE SNOW SOUTH INTO THE MID
MISSISSIPPI RIVER VALLEY. SINCE THIS IS A RELATIVELY NEW
DEVELOPMENT...STILL KEPT THE SNOW CHANCES IN THE MODEL CONSENSUS
FOR SATURDAY NIGHT AND SUNDAY...BUT REMOVED THEM FOR SATURDAY
AFTERNOON. IF THIS TREND CONTINUES...FUTURE SHIFTS CAN TAKE THEM
OUT OR LOWER THESE SNOW CHANCES FURTHER.
TEMPERATURES FOR EARLY NEXT WEEK...LOOK TO BE MUCH COLDER WITH
HIGH TEMPERATURES IN THE SINGLE DIGITS AND TEENS...AND LOW
TEMPERATURES ON EITHER SIDE OF ZERO.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1142 AM CST WED JAN 28 2015
MAIN AVIATION CONCERNS IS THE POSSIBILITY OF FREEZING DRIZZLE THIS
EVENING INTO TONIGHT AT BOTH RST AND LSE TAF SITES...AND
LIFR/IFR/MVFR CONDITIONS AT THE TAF SITES THROUGH THE TAF PERIOD.
SURFACE LOW TRACKS INTO SOUTHERN IOWA AND NORTHERN ILLINOIS
TONIGHT. THE LATEST 28.12Z NAM/GFS AND 28.15Z RAP ARE INDICATING
SURFACE TEMPERATURES WILL BE TRICKY THIS EVENING INTO TONIGHT...AS
WARM AIR ADVECTS INTO BOTH TAF SITES THIS AFTERNOON. THE MODELS
SUGGEST TEMPERATURES WILL HOVER AROUND THE FREEZING MARK AND
ABOVE FREEZING THIS EVENING INTO TONIGHT. WITH ENOUGH LIFT AND
THE NEAR SURFACE BOUNDARY LAYER MOIST...PRECIPITATION TYPE WILL BE
ALL LIQUID AND DEPENDING ON TEMPERATURES...THERE IS POTENTIAL FOR
PATCHY FREEZING DRIZZLE TO OCCUR AT BOTH RST AND LSE TAF SITES
FROM 02Z THURSDAY INTO 12Z THURSDAY. AT THIS TIME...WITH THE
FREEZING DRIZZLE EXPECTED TO BE PATCHY...DID NOT INTRODUCE INTO
THE TAFS.
NEXT CONCERN ARE LIFR/IFR/MVFR CONDITIONS AT BOTH TAF SITES THROUGH
THE TAF PERIOD. LOW LEVEL MOISTURE WILL CONTINUE TO LINGER OVER MUCH
OF THE REGION THIS AFTERNOON INTO THURSDAY. CEILINGS WILL HOVER IN
THE LIFR AND IFR CONDITIONS AT RST...AS CEILINGS CURRENTLY BELOW 500
FEET AND RISE INTO THE 500-1000 FEET RANGE LATE THIS AFTERNOON.
THEN...AS SURFACE LOW IN SOUTHERN IOWA AND SUNSET CEILINGS WILL
LOWER BELOW 500 FEET THIS EVENING. AT THE LSE TAF SITE CEILINGS
WILL LOWER INTO THE 500-1000 FEET RANGE AROUND 02Z AND RISE BACK
INTO THE MVFR RANGE AROUND 09Z THURSDAY. WITH SURFACE LOW/FRONT
PASSAGE BETWEEN 09-12Z THURSDAY...PRESSURE GRADIENT TIGHTENS ON
THE BACKSIDE AND NORTHWEST WINDS INCREASE. HAVE INTRODUCE WIND
GUST OF 27 KNOTS AT RST TAF SITE AND 23 KNOTS AT LSE TAF SITE AT
12Z THURSDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FREEZING RAIN ADVISORY FROM 9 PM THIS EVENING TO 6 AM CST
THURSDAY FOR WIZ017-029-034-042>044.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...DTJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1142 AM CST WED JAN 28 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 332 AM CST WED JAN 28 2015
MAIN CONCERNS THIS PERIOD...DZ/FZDZ CHANCES TONIGHT...CLOUDS AND
TEMPERATURES BOTH TODAY AND TONIGHT.
06Z DATA ANALYSIS HAD HIGH PRESSURE OVER THE OH VALLEY AND DEEPENING
LOW PRESSURE OVER THE CENTRAL/NORTHERN PLAINS. SFC OBS AND FOG-
PRODUCT IMAGERY SHOW AN IFR/MVFR STRATUS DECK ACROSS MUCH OF WI/MN
AND EASTERN IA. LATEST AVAILABLE PILOT REPORTS INDICATED THIS CLOUD
DECK ABOUT 1000 FT THICK. THIS MOISTURE/CLOUDS TRAPPED UNDER A
STRONG AND STRENGTHENING INVERSION NEAR 900MB. THE CLOUD BLANKET AND
INCREASING SOUTHEAST GRADIENT WINDS HOLDING TEMPS STEADY IN THE
MID/UPPER 20S ACROSS MUCH OF THE REGION EARLY THIS MORNING.
INITIALIZATIONS OF 28.00Z MODELS GENERALLY LOOK QUITE GOOD.
SHORTWAVE RIDGING QUICKLY MOVES ACROSS THE UPPER MIDWEST TODAY AND
NORTHERN/SOUTHERN STREAM ENERGY CARVES OUT TROUGHING IN THE CENTRAL/
NORTHERN PLAINS. THE 2 PIECES OF ENERGY NEARLY PHASE TONIGHT AS THEY
AND DEEPENING MID LEVEL TROUGHING MOVES ACROSS THE MID/UPPER MS
VALLEY. THE TIGHTER CONSENSUS FOR TODAY/TONIGHT FAVORS A COMPROMISE
OF THE EARLIER 26.00Z/27.00Z RUNS. SHORT TERM FCST CONFIDENCE
REMAINS GOOD BUT THE FCST HINGES ON LOWER LEVEL MOISTURE WHICH THE
MODELS TYPICALLY STRUGGLE WITH.
IN THE SHORT TERM...THE STRATUS DECK WILL ONCE AGAIN BE PROBLEMATIC
TODAY FOR HIGH TEMPS. SOUTHEAST TO SOUTHWEST SFC-850MB GRADIENT FLOW
INCREASE ACROSS THE AREA TODAY AS THE PLAINS LOW MOVE TO NEAR
KFSD/KOMA THIS AFTERNOON. INVERSION OVER THE AREA REMAINS STRONG
UNDER THE INCREASING 925-850MB WARM ADVECTION. BY THIS AFTERNOON...
DEEPER/STRONGER LIFT ARRIVES...WITH AN INCREASE OF LOWER LEVEL
MOISTURE. ALL THIS POINTS TO THE LOWER STRATUS HANGING TOUGH OVER
THE AREA TODAY WITH LITTLE IF ANY SUNSHINE. CIRRUS SHIELD AHEAD OF
THE MID/UPPER LEVEL TROUGH MOVES OVER THE REGION FOR THE AFTERNOON
AS WELL. SOUTH-SOUTHEAST WINDS OVER AND LOW LEVEL WARM ADVECTION
OVER THE AREA TODAY...SO EXPECT TEMPS TO WARM A LITTLE...BUT ONLY TO
THE MID/UPPER 30S ACROSS MOST OF THE FCST AREA.
SFC THRU MID LEVEL TROUGH AXIS MOVES ACROSS THE AREA TONIGHT...WITH
MOISTURE/SATURATION IN ROUGHLY THE SFC-800MB PORTION OF THE COLUMN.
LOWER LEVEL LIFT/CONVERGENCE WITH THE SFC-850MB TROUGH AXIS...WITH
DEEP LAYERED LIFT/DIVERGENCE ALOFT AHEAD OF THE SHORTWAVES AND MID
LEVEL TROUGH AXIS. MODEL SOUNDINGS CONTINUE TO SHOW COLDEST TEMPS IN
THE LOWER SATURATED PORTION OF THE COLUMN AROUND -5C...INDICATING NO
ICE IN THE CLOUD DEPTH. PRECIP CHANCES TONIGHT REMAIN MAINLY -DZ/
-FZDZ. CONFINED THE HIGHEST CHANCES BETWEEN 03Z-09Z WHEN THE SFC-
850MB TROUGH AXIS AND ITS CONVERGENCE SLIDES ACROSS THE FCST AREA.
MORE CONSISTENT SIGNAL AMONG THE MODELS FOR LIGHT PRECIP PRODUCTION
REMAINS OVER THE NORTHEAST HALF OF THE FCST AREA...WITH HIGHER
PRECIP CHANCES THERE TONIGHT. GREATER THREAT OF MINOR ICING IS OVER
THE NORTHEAST HALF OF THE FCST AREA WERE TEMPS TODAY/TONIGHT WILL BE
MORE IN THE LOWER 30S AND ROAD TEMPS WILL REMAIN CLOSER TO OR BELOW
FREEZING. MAY YET NEED A FREEZING RAIN/DRIZZLE ADVISORY FOR THE
NORTHEAST 1/3 TO 1/2 OF THE FCST AREA. WILL LET DAY CREW HAVE
ANOTHER CYCLE OF MODELS TO LOOK AT AND SEE WHAT SFC TEMPS DO TODAY
TO MAKE THE CALL ON THAT. WITH THICKER LOW CLOUDS TONIGHT...THE
DZ/FZDZ CHANCES AND SOME PATCHY FOG...NEARLY STEADY TEMPS EXPECTED
DURING THE EVENING... THEN FALLING LATE AFTER THE TROUGH AXIS
PASSES/LOW LEVEL COLD ADVECTION/INCREASING NORTHWEST WINDS SPREAD
ACROSS THE AREA. BY THIS TIME BULK OF THE DEEP LAYERED LIFT HAS
SHIFTED EAST OF THE AREA WITH THE TROUGH AXIS AND DZ/FZDZ CHANCES
WILL BE DECREASING. TRENDED TOWARD COOLER OF GUIDANCE HIGHS TODAY
AND WARMER OF GUIDANCE LOWS TONIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 332 AM CST WED JAN 28 2015
MAIN FCST CONCERNS FOR THU THRU FRI NIGHT...LINGERING DZ/FZDZ
CHANCES THU MORNING...CLOUD/TEMPERATURE TRENDS THRU THE PERIOD.
28.00Z MODELS IN GOOD AGREEMENT FOR A SECOND NORTHERN STREAM
SHORTWAVE TO DROP QUICKLY ACROSS THE WESTERN GREAT LAKES THU
AFTERNOON/EVENING. GOOD BETWEEN MODEL AND RUN-TO-RUN CONSISTENCY FOR
HGTS TO THEN RISE FRI/FRI NIGHT...AHEAD OF THE NEXT NORTHERN/
SOUTHERN STREAM ENERGY HEADED TOWARD THE CENTRAL CONUS. FCST
CONFIDENCE IN THE THU THRU FRI NIGHT PERIOD IS GOOD THIS CYCLE.
THIS PERIOD SHAPING UP TO BE A COOLER/DRY/QUIET PERIOD BEFORE THE
NEXT STRONGER SYSTEM TAKES AIM AT THE UPPER MIDWEST FOR THE WEEKEND.
LOW LEVEL COLD ADVECTION AND DEEPER LAYERED SUBSIDENCE CONTINUE TO
SPREAD ACROSS THE AREA THU MORNING. MAINLY LIMITED ANY LINGERING DZ/
FZDZ CHANCES TO THE 12-15Z PERIOD OVER THE EAST HALF OF THE FCST
AREA. SHORTWAVE DROPPING ACROSS THE WESTERN GREAT LAKES THU
AFTERNOON/EVENING MAINLY PROVIDES THE AREA WITH A REINFORCING SHOT
OF LOW LEVEL COLD ADVECTION. APPEARS HIGHS THU WILL BE IN THE
MORNING WITH STEADY/SLOWING FALLING TEMPS THRU THE DAY UNDER THE
STRONGER COLD ADVECTION. STRONGER SUBSIDENCE/COLD ADVECTION AND CAN
HIGH PRESSURE BUILDING IN SHOULD CLEAR OUT THE LOWER CLOUDS THU
AFTERNOON/NIGHT. SFC RIDGE AXIS DRIFTS ACROSS THE AREA LATE THU
NIGHT/FRI MORNING...UNDER WHAT SHOULD BE MOSTLY CLEAR SKIES. THU
NIGHT LOWS LOOKING TO BE CLOSER TO NORMAL THAN THEY/VE BEEN DURING
THE PAST 2 WEEKS. LOW LEVEL WARM ADVECTION RETURNS FRI AS THE SFC-
850MB RIDGE AXIS MOVES SOUTH OF THE AREA. STRONGER OF THIS SPREADS
ACROSS THE AREA FRI NIGHT...WITH LOWS LOOKING TO BE FRI EVENING THEN
SLOWLY RISING TEMPS AFTER MIDNIGHT AS CLOUDS START TO INCREASE AND
SOUTHWEST GRADIENT WINDS FOR BOUNDARY LAYER MIXING INCREASE A BIT.
USED THE MODEL/ENSEMBLE BLEND OF GUIDANCE HIGHS/LOWS FOR THU THRU
FRI NIGHT.
FOR SATURDAY THRU TUESDAY.../DAYS 4 TO 7/...
MAIN FCST CONCERNS THIS PERIOD...SNOW CHANCES LATE SAT/SAT
NIGHT/SUN...COLD TEMPERATURES MOM-TUE.
28.00Z MEDIUM RANGE MODELS SHOW IMPROVING AGREEMENT SAT/SUN FOR
NORTHERN/SOUTHERN STREAM ENERGY TO AT LEAST PARTIALLY PHASES OVER
THE CENTRAL CONUS. TREND IS A BIT STRONGER/MORE PHASED WITH THE
STREAMS/SHORTWAVES OVER THE CENTRAL CONUS BY SUNDAY. GOOD BETWEEN
MODEL AND RUN-TO-RUN CONSISTENCY FOR THE TROUGH AXIS TO THEN MOVE
ACROSS THE MID/UPPER MS VALLEY SUN NIGHT...LEAVING THE DOOR OPEN FOR
NORTHWEST FLOW AND A STRONGER SHOT OF CANADIAN/ARCTIC AIR TO DROP
INTO THE UPPER MIDWEST FOR EARLY NEXT WEEK. GIVEN SOME LOWER LEVEL
DETAIL DIFFERENCES...FCST CONFIDENCE FOR SAT THRU TUE REMAINS
AVERAGE THIS CYCLE.
PHASING SHORTWAVES/DEEPENING TROUGH OVER THE PLAINS SAT/SUN SENDS
INCREASING MOISTURE NORTHWARD TOWARD THE UPPER MIDWEST FOR THE
WEEKEND. PW VALUES OF AROUND 1/2 INCH INDICATED IN THE INFLOW
AIRMASS AHEAD OF THE DEVELOPING TROUGH/SFC LOW. THIS MOISTURE BEING
PUSHED INTO A COLUMN WITH SFC-600MB TEMPS FAVORING A DEEP DENDRITIC
GROWTH ZONE AND FAVORABLE LIFT/DIVERGENCE IN THE MID/UPPER LEVELS
AHEAD OF THE PLAINS TROUGH. MODEL SOUNDINGS/X-SECTIONS SHOWING
COLUMN SATURATED FROM THE SFC TO 300MB OVER MUCH OF THE FCST AREA
FOR BY LATER SAT NIGHT AND FOR SUN. DETAIL DIFFERENCES INCLUDE HOW
MUCH AND QUICKLY PHASING ACTUALLY OCCURS AND HOW FAR NORTHWARD THE
GREATER THE 925-700MB MOISTURE AND THERMODYNAMIC FORCING ENDS UP
OCCURRING. POTENTIAL ALSO EXISTS FOR A LONGER DURATION PERIOD OF
SNOW FOR PARTS OR ALL OF THE FCST AREA FROM SAT NIGHT INTO SUN
NIGHT. SNOW CHANCES IN THE 30-50 PERCENT RANGE FOR SAT NIGHT/SUNDAY
LOOK GOOD FOR NOW...UNTIL THE DETAILS GET SORTED OUT. OVER WHAT
WOULD BE FRESH SNOW COVER FOR MUCH/ALL OF THE AREA...NORTHWEST
FLOW BEHIND THE TROUGH SENDS ANOTHER CAN/ARCTIC HIGH INTO THE
UPPER MIDWEST FOR SUN NIGHT INTO TUE. 925MB TEMPS PROGGED IN THE
-15C TO -20C RANGE MON INTO MON NIGHT. TEMPS TO START NEXT WEEK
CONTINUE TO TREND BELOW TO MUCH BELOW NORMAL. MODEL/ENSEMBLE
CONSENSUS OF HIGHS/LOWS FOR SAT THRU TUE LOOKS GOOD AT THIS TIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1142 AM CST WED JAN 28 2015
MAIN AVIATION CONCERNS IS THE POSSIBILITY OF FREEZING DRIZZLE THIS
EVENING INTO TONIGHT AT BOTH RST AND LSE TAF SITES...AND
LIFR/IFR/MVFR CONDITIONS AT THE TAF SITES THROUGH THE TAF PERIOD.
SURFACE LOW TRACKS INTO SOUTHERN IOWA AND NORTHERN ILLINOIS
TONIGHT. THE LATEST 28.12Z NAM/GFS AND 28.15Z RAP ARE INDICATING
SURFACE TEMPERATURES WILL BE TRICKY THIS EVENING INTO TONIGHT...AS
WARM AIR ADVECTS INTO BOTH TAF SITES THIS AFTERNOON. THE MODELS
SUGGEST TEMPERATURES WILL HOVER AROUND THE FREEZING MARK AND
ABOVE FREEZING THIS EVENING INTO TONIGHT. WITH ENOUGH LIFT AND
THE NEAR SURFACE BOUNDARY LAYER MOIST...PRECIPITATION TYPE WILL BE
ALL LIQUID AND DEPENDING ON TEMPERATURES...THERE IS POTENTIAL FOR
PATCHY FREEZING DRIZZLE TO OCCUR AT BOTH RST AND LSE TAF SITES
FROM 02Z THURSDAY INTO 12Z THURSDAY. AT THIS TIME...WITH THE
FREEZING DRIZZLE EXPECTED TO BE PATCHY...DID NOT INTRODUCE INTO
THE TAFS.
NEXT CONCERN ARE LIFR/IFR/MVFR CONDITIONS AT BOTH TAF SITES THROUGH
THE TAF PERIOD. LOW LEVEL MOISTURE WILL CONTINUE TO LINGER OVER MUCH
OF THE REGION THIS AFTERNOON INTO THURSDAY. CEILINGS WILL HOVER IN
THE LIFR AND IFR CONDITIONS AT RST...AS CEILINGS CURRENTLY BELOW 500
FEET AND RISE INTO THE 500-1000 FEET RANGE LATE THIS AFTERNOON.
THEN...AS SURFACE LOW IN SOUTHERN IOWA AND SUNSET CEILINGS WILL
LOWER BELOW 500 FEET THIS EVENING. AT THE LSE TAF SITE CEILINGS
WILL LOWER INTO THE 500-1000 FEET RANGE AROUND 02Z AND RISE BACK
INTO THE MVFR RANGE AROUND 09Z THURSDAY. WITH SURFACE LOW/FRONT
PASSAGE BETWEEN 09-12Z THURSDAY...PRESSURE GRADIENT TIGHTENS ON
THE BACKSIDE AND NORTHWEST WINDS INCREASE. HAVE INTRODUCE WIND
GUST OF 27 KNOTS AT RST TAF SITE AND 23 KNOTS AT LSE TAF SITE AT
12Z THURSDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION...DTJ