Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 01/29/12
PREVIOUS FORECAST DISCUSSION IS BELOW...
AS OF 400 PM EST...THE WATER VAPOR LOOP THIS AFTERNOON CONTINUES
TO SHOW A SHORT-WAVE IN THE W/SW FLOW APPROACHING FROM THE GREAT
LAKES REGION AND LAKE ERIE. A FASTING MOVING SFC LOW OR A CLIPPER
ROTATING AROUND A CLOSED H500 CIRCULATION OVER HUDSONS BAY IS
MOVING ACROSS SE ONTARIO INTO SRN QUEBEC. THE COLD FRONT TO THE
CLIPPER HAS MOVED ACROSS OH AND MI AND IS MOVING INTO WRN NY AND
WRN PA. CLOUDS WILL CONTINUE TO THICKEN AND LOWER AHEAD OF THE
FRONT. THERE IS A BAND OF SNOW SHOWERS MOVING INTO THE TUG HILL
PLATEAU REGION...THAT WILL MOVE INTO THE WRN DACKS OVER THE NEXT
FEW HOURS. THE BEST LOW-LEVEL CONVERGENCE IS ALONG THE FRONTAL
BOUNDARY...AND MAINLY NORTH OF THE MOHAWK RIVER VALLEY. MOISTURE
WILL BE TAPPED FROM THE ERN GREAT LAKES WITH THE BEST MOISTURE
CONVERGENCE NORTHWEST OF THE CAPITAL REGION ALONG THE NOSE OF A
50-60 KT H850 LLJ. THE LATEST HRRR 3KM COLUMNAR MAX REF CONTINUES
TO SHOW A BROKEN BAND OF CELLS WITH SOME 30-40 DBZ ECHOES MOVE
ACROSS THE FCST AREA AHEAD OF THE FRONT BTWN 00Z-02Z. THERE COULD
BE SOME ISOLD SNOW SQUALLS THAT PUT OUT A BRIEF BURST OF SNOW.
WE KEPT THE HIGHEST POPS TO THE NORTH AND WEST OF THE CAPITAL
REGION...AND SLIGHT CHC TO LOW CHC FURTHER SOUTH AND EAST.
THE WINDS INCREASE IN THE WAKE OF THE FRONT FROM THE W/NW AT 15 TO
25 MPH WITH A FEW GUSTS IN THE 30-40 MPH RANGE...AND THE LAKE EFFECT
POTENTIAL INCREASES FOR THE WRN DACKS. THE NAM AND CAN REGIONAL
CONTINUE TO PRODUCE A QUARTER TO FOUR TENTHS OF AN INCH OF QPF WITH
A FAVORABLE 260 DEGREE LAKE TRAJECTORY IN THIS AREA. THE SFC-H850
WINDS ALIGN WELL FROM THE WEST WITH LITTLE DIRECTIONAL SHEAR. THE
INVERSION IS WELL ABOVE 10KFT AGL BASED ON NAM SOUNDING PROFILES
OVER NRN HERKIMER COUNTY...AND THEN SLOWLY LOWER TO ABOUT 7-8 KFT
AGL AROUND 12Z- 15Z. THE INSTABILITY CLASS OFF THE BUFKIT PROFILES
CONTINUES TO BE CONDITIONAL WITH MARGINAL DELTA T/S. WE PUT OUT A
LAKE EFFECT ADVISORY FOR NRN HERKIMER CTY FROM 00Z/SUN TO 15/SUN FOR
NRN HERKIMER CTY. THE LOCATIONS IMPACTED WILL GENERALLY BE FROM THE
RT 28/OLD FORGE CORRIDOR NORTHWARD WITH 3 TO 7 INCHES OF
ACCUMULATION. THERE COULD ALSO BE SOME BLOWING SNOW TONIGHT. FURTHER
EAST INTO HAMILTON COUNTY EXPECT 2 TO 5 INCHES OF SNOWFALL WITH THE
BAND EXTENSION IN QUESTION. ELSEWHERE FROM THE SCT SNOW SHOWERS AND
ISOLD SQUALLS...A COATING TO HALF AN INCH WILL BE POSSIBLE. COLD
ADVECTION OCCURS OVERNIGHT WITH H850 TEMPS FALLING BACK TO -8C TO
-12C. EXPECT LOWS TO BE A LITTLE COLDER TONIGHT THAN LAST NIGHT WITH
LOWS IN THE MID AND U20S IN THE VALLEYS...AND UPPER TEENS AND LOWER
20S OVER THE MTNS.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
TOMORROW...THE LAKE EFFECT BEGINS TO DIMINISH WITH THE LOWERING
INVERSION...AND THE LOW LEVEL FLOW BACKING TO THE SOUTH/SOUTHWEST
AHEAD OF THE NEXT DISTURBANCE APPROACHING FROM THE LOWER GREAT
LAKES REGION. HIGH PRESSURE WILL BRIEFLY RIDGE IN FROM THE SOUTH.
THE SHORT-WAVE IS A BIT STRONGER THAN THE ONE TONIGHT. THE STRONG
CYCLONIC VORTICITY ADVECTION COUPLED WITH STEEP LAPSE RATES MAY
FOCUS A ROBUST BAND OF SNOW SHOWERS APPROACHING FROM W-CNTRL NY
LATE IN THE AFTERNOON. WE INCREASED THE POPS PREDOMINANTLY WEST OF
THE HUDSON VALLEY IN THE MID TO LATE AFTERNOON WITH SLIGHT CHC TO
CHC VALUES...EXCEPT LIKELY AND CATEGORICAL VALUES OVER THE WRN
MOHAWK VALLEY...AND SRN DACKS. WE WENT CLOSE TO GFSMOS MAX TEMPS
WITH HIGHS IN THE U30S TO L40S IN THE VALLEYS /A FEW M40S IN THE
MID HUDSON VALLEY/...AND U20S TO M30S OVER THE MTNS.
TOMORROW NIGHT...THE POTENT VORT MAX AND ITS ASSOCIATED COLD FRONT
TIED TO THE TROUGH OF LOW PRESSURE/CLIPPER MOVING ACROSS SE QUEBEC
WILL MOVE ACROSS THE REGION BTWN 00Z-06Z. THE STRONG CONVERGENCE
ALONG THE BOUNDARY MAY PRODUCE MORE WIDESPREAD ONE INCH AMOUNTS
WITH THIS SYSTEM. THE WRN DACKS COULD GET ANOTHER 1 TO 4
INCHES...AS LAKE EFFECT STARTS AGAIN. LOWS WILL GENERALLY BE IN
THE TEENS OVER THE HILLS AND MTNS...AND L20S IN THE VALLEYS...AS
STRONG COLD ADVECTION SWEEPS OVER THE REGION.
MONDAY...ANOTHER BRIEF LAKE CONNECTION IS EXPECTED MONDAY MORNING.
THIS TIME A 290 DEGREE LOW-LEVEL TRAJECTORY WOULD BE FAVORED WITH
THE SW DACKS...W-CNTRL MOHAWK VALLEY...AND NRN CATSKILLS IMPACTED.
WE COULD SEE A BAND SNEAK DOWN THE MOHAWK RIVER VALLEY EARLY IN
THE DAY...AND WE KEPT SOME SLIGHT-LOW CHC POPS IN FOR THE CAPITAL
REGION...TACONICS...AND BERKSHIRES. RIGHT NOW...SNOW ACCUMULATIONS
WEST OF ALBANY WOULD BE IN THE 1 TO 3 INCH RANGE. THE NAM
CONTINUES TO SHOW THE LAKE EFFECT POTENTIAL WEAKENING DURING THE
DAY WITH THE FLOW BEGINNING TO BACK AGAIN...AND THE INVERSION
LOWERING...AS HIGH PRESSURE BRIEFLY BUILDS IN AGAIN. H850 TEMPS
TUMBLE CLOSER TO SEASONABLE LEVELS AT -13C TO -16C OVER THE REGION
WITH HIGHS IN THE U20S TO M30S IN THE VALLEYS AND LOWER
ELEVATIONS...AND LOWER TO M20S OVER THE MTNS.
MONDAY NIGHT...A WARM FRONT WILL MOVE INTO THE REGION FROM THE
OHIO VALLEY AND THE LOWER GREAT LAKES REGION. THE ISENTROPIC LIFT
INCREASES ON THE 295K SFC. OVERRUNNING LIGHT SNOWFALL WILL
OVERSPREAD THE REGION. THE BETTER QG LIFT IS FROM THE HUDSON
VALLEY WESTWARD. WE KEPT HIGH CHC POPS IN THE FORECAST FOR THIS
TIME FRAME. THE WARM FRONT SLOWLY LIFT NORTHWARD OF THE I-90
CORRIDOR BY TUESDAY MORNING.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AT THE START OF THE EXTENDED PERIOD...A WARM FRONT WILL BE MOVING
NORTH THROUGH THE REGION DURING TUESDAY MORNING. THIS WILL CONTINUE
TO BRING SOME LIGHT SNOW FOR AREAS MAINLY TO THE NORTH OF I-90. BY
AFTERNOON...MUCH OF THE PRECIPITATION SHOULD BE DONE ACROSS THE
REGION....WITH THE EXCEPTION ACROSS PARTS OF THE SOUTHERN
ADIRONDACKS/LAKE GEORGE AREA.
BEHIND THIS WARM FRONT...A WARMER SOUTHERLY FLOW WILL TAKE OVER.
THIS WILL ALLOW FOR TUESDAY NIGHT MIN TEMPS NOT TO BE AS COOL AS
RECENT NIGHTS...WITH MUCH OF THE CAPITAL REGION REMAINING ABOVE
FREEZING EVEN DURING THE OVERNIGHT. TEMPS WILL CONTINUE TO BE ABOVE
NORMAL RIGHT INTO WEDNESDAY...WITH 40S ACROSS THE ENTIRE AREA BY WED
AFTN. SOME RAIN SHOWERS WILL BE POSSIBLE...ESP FOR WEDNESDAY...AS A
STORM SYSTEM MOVES ACROSS SOUTHERN CANADA AND THE STORM/S COLD FRONT
PROVIDES SOME LIFT FOR SHOWERS ACROSS OUR AREA.
THE MODELS DISAGREE ON WHAT OCCURS FOR WEDNESDAY NIGHT AND BEYOND.
THE 12 UTC ECMWF ATTEMPTS TO DEVELOP A WAVE ALONG THE FRONTAL
BOUNDARY AS IT MOVES OFF THE EASTERN SEABOARD...WHICH COULD BRING
SOME ADDITIONAL LIGHT PRECIP /RAIN OR SNOW/ TO SOUTHEASTERN PARTS OF
THE AREA FOR WED NIGHT INTO THURSDAY. MEANWHILE...THE GFS IS MUCH
MORE PROGRESSIVE AND KEEPS IT FAIRLY DRY WITH JUST SOME CYCLONIC
FLOW RAIN/SNOW SHOWER FOR NORTHWESTERN PARTS OF THE AREA. THE GFS
HAS BEEN PERSISTENT IN GOING AGAINST THE IDEA OF A BIG STORM DURING
THIS PERIOD...AND THE 12 UTC GEFS ONLY SUPPORTS LIGHT PRECIP FROM
WRAP AROUND OF THE CANADIAN LOW PRESSURE DURING THIS TIME FRAME AS
WELL. EVEN THE ECMWF IS STARTING TO BACK OFF ON THE IDEA OF A
STRONGER SECONDARY WAVE DURING THIS PERIOD...AS IT ONLY HAS A WEAK
LOW ALONG THE FRONT...WITH THE STORM WAITING UNTIL ITS MUCH FURTHER
OFFSHORE BEFORE RAPID DEEPENING. FOR NOW...WITH GO WITH LOW POPS
FOR WED NIGHT/THURS AND CONTINUE TO SHOW TEMPS ABOVE NORMAL.
TEMPS WILL CONTINUE TO BE SOMEWHAT ABOVE NORMAL FOR FRIDAY INTO
SATURDAY ACROSS THE AREA. FOR NOW...WILL GO WITH SLIGHT CHC POPS AS
SOME WEAK UPPER LEVEL DISTURBANCES MAY ALLOW FOR A RAIN OR SNOW
SHOWER...ESP FOR THE HIGHER TERRAIN...BEFORE A STRONG AREA OF HIGH
PRESSURE MOVES TOWARDS THE AREA FOR LATER IN THE WEEKEND.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
GENERALLY VFR CONDITIONS ARE EXPECTED AT THE KGFL/KALB/KPOU TAF
SITES FOR THE TAF PERIOD ENDING AT 00Z MONDAY. THE EXCEPTION MAY BE
THE THREAT OF SNOW/RAIN SHOWERS AT THE KGFL/KALB TAF SITES THIS
EVENING AS A FRONTAL BOUNDARY MOVES ACROSS THE REGION. EXPECT THE
SHOWERS TO THE WEST TO MAINLY DISIPATE AS THEY HEAD INTO THE HUDSON
VALLEY...BUT THE THREAT OF A SHOWERS CAN NOT BE RULED OUT...SO HAVE
INLCUDED VCSH AT KGFL/KALB THROUGH ABOUT 08Z. AFTER THAT...VFR
CONDITIONS FOR THE REST OF THE TAF PERIOD.
WINDS WILL BE SOUTHERLY AHEAD OF THE FRONTAL BOUNDARY AT 5 TO 10 KTS
WITH SOME GUSTS TO AROUND 15 KTS. BEHIND THE FRONT...THE WINDS WILL
SHIFT TO SOUTHWEST OR WEST AT 10 TO 15 KTS WITH GUSTS UP TO AROUND
20 KTS. THESE WINDS WILL SUBSIDE SOMEWHAT LATE TONIGHT...THEN
INCREASE AGAIN SUNDAY MORNING FRONT THE WEST AT 10 TO 15 KTS WITH
GUSTS OF 20 TO 25 KTS. BY LATE IN THE DAY ON SUNDAY...WINDS WILL
DECREASE TO 10 KTS OR LESS AND SHIFT TO A SOUTHERLY DIRECTION.
OUTLOOK...
SUN NIGHT...VFR/MVFR. CHC -SHSN.
MON-TUE...VFR. NO SIG WX.
TUE NIGHT-WED...VFR/MVFR. CHC -SHRA/-SHSN.
THU...VFR...SLIGHT CHC -SHRA/-SHSN.
&&
.HYDROLOGY...
RIVER FLOWS CONTINUE TO RECEDE FROM THE RAIN AND MIXED
PRECIPITATION YESTERDAY. THE FLOOD WARNING WAS CANCELED FOR
MCKEEVER ON THE MOOSE RIVER...AS THE ICE JAM HAS BROKEN...AND WATER
IS FREELY FLOWING AGAIN.
A COUPLE OF CLIPPER LOW PRESSURE SYSTEMS AND THEIR ASSOCIATED COLD
FRONTS WILL IMPACT THE REGION LATE TODAY AND TONIGHT...AND SUNDAY
NIGHT INTO MONDAY MORNING. SOME SCATTERED SNOW SHOWERS AND
FLURRIES WILL BE COMMON WITH LIGHT SNOW ACCUMULATIONS UP TO A FEW
INCHES IN THE SOUTHERN ADIRONDACKS. SOME MODERATE SNOW
ACCUMULATIONS WILL BE POSSIBLE TONIGHT IN THE WESTERN ADIRONDACKS. A
WARM FRONT WILL ALSO BRING SOME LIGHT SNOW MONDAY NIGHT INTO
TUESDAY MORNING.
OVERALL...RIVER FLOWS WILL CONTINUE TO RECEDE INTO THE MID WEEK.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST SUNDAY FOR NYZ032.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...WASULA
NEAR TERM...FRUGIS/WASULA
SHORT TERM...WASULA
LONG TERM...FRUGIS
AVIATION...GJM
HYDROLOGY...WASULA
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
257 PM CST FRI JAN 27 2012
.DISCUSSION...
333 AM CST
FOR TODAY...CLOUDS ON THE BACKSIDE OF THE LOW THAT IS LIFTING OUT OF
THE OHIO VALLEY...WILL CONTINUE TO CHARGE TO THE SOUTHEAST. AIRCRAFT
SOUNDINGS OUT OF ORD SHOW A FAIRLY SHALLOW SATURATED LAYER REMAINING.
UPSTREAM SOUNDINGS AND RUC ANALYSIS SHOW AN OVERALL DRYING TREND
TO CONTINUE AND NOT EXPECTING ANY EXPANSION TO THE CLOUDS EARLY
THIS MORNING. MOST LOCATIONS SHOULD SEE MOSTLY SUNNY AND BLUE
SKIES...WITH THE EXCEPTION OF THE FAR SOUTHEAST WHERE THEY WILL BE
SLUGGISH. BOTH THE RUC AND NARRE-TL GUIDANCE ARE IN AGREEMENT THAT
THE NORTHWEST SHOULD BE CLEAR BY SUNRISE...WITH THE CHICAGO METRO
A FEW HOURS BEYOND. FAST ON THE HEELS OF THE CLEAR SKIES WILL BE
MID LEVEL CLOUDS ARRIVING FROM THE WEST WITH THE NEXT WAVE MOVING
IN...AND THE ENTIRE CWA IS THEN EXPECTED TO BECOME CLOUDY AGAIN
BY THE EARLY TO MID AFTERNOON. WITH NO REAL CHANGE TO THE AIRMASS
TODAY AND TONIGHT...TEMPERATURES ARE EXPECTED TO BE CLOSE TO
CARBON COPIES OF YESTERDAY. FOCUS IN THE EVENING WILL THEN TURN
TOWARDS THE WEST AS A WEAK CLIPPER /THAT IS NOTED ON REGIONAL
RADAR THIS MORNING ACROSS THE NORTHERN DAKOTAS/ AND A WEAK
SOUTHERN STREAM SYSTEM /NEAR THE OKLAHOMA PAN HANDLE THIS MORNING/
SHIFT EAST AND NOT QUITE MERGE...RATHER COMPLICATE THE EVENING
FORECAST. THE GOOD NEWS IS THAT THE TIMING SHOULD BE AS RUSH HOUR
COMES TO A CLOSE FOR THE FAR NORTHWEST...AND HOURS BEYOND THE
CHICAGO METRO RUSH.
THE OVERALL PICTURE HAS BEEN PRETTY CONSISTENT THE LAST FEW DAYS
THAT ANYWHERE FROM AN INCH TO INCH AND A HALF OF SNOW ARE EXPECTED
WITH THIS SYSTEM. THE EARLIER 18/00Z GUIDANCE SEEMED TO BE IN DECENT
AGREEMENT WITH KEEPING THE BEST FORCING NORTH AND HAVING A BIT MORE
OF A UNIFORM TOTAL ACROSS THE AREA...WITH POTENTIALLY HIGHER AMOUNTS
NORTH OF I-80...BUT THE 00Z GFS AND ECMWF BEGAN TO THROW A WRENCH
AND GIVE THE SOUTHERN SECTION A LITTLE MORE GUSTO THAN PREVIOUS
RUNS...MAKING THE SNOW FALL A LITTLE MORE DISJOINTED. WITH DRY AIR
INVADING THE REGION THIS MORNING...IT WILL TAKE SOME TIME TO
SATURATE THE COLUMN BEFORE IT PRECIPITATES TO THE GROUND. THE OTHER
QUESTION WILL BE ON WHAT FORM THE PRECIP WILL BE AT THE ONSET.
FORECAST SOUNDINGS ARE TRYING TO HOLD ONTO SURFACE TEMPERATURES AT
OR SLIGHTLY ABOVE FREEZING THROUGH ROUGHLY 9 TO 10 PM
TONIGHT...CONTINUING TO COOL BEYOND AND INTO THE OVERNIGHT HOURS.
SIMPLE CROSS HAIRS TECHNIQUE SHOWS THE HIGHEST OMEGA VALUES
INTERSECTING THE DGZ IN A 2 OR SO HOUR WINDOW...AND GENERALLY IN THE
3-4-5Z TIME FRAME. IT IS WITHIN THIS WINDOW THAT THE BEST
ACCUMULATION SHOULD HAPPEN...BUT NOT ANTICIPATING MUCH BEYOND A HALF
INCH AN HOUR RATE WHEN THE ATMOSPHERE IS MOST EFFICIENT...AND WILL
LIKELY START AS A HEAVIER/WET SNOW. STILL CONFIDENT THAT THE
TOTALS WILL BE LOW AND IN THE GENERAL INCH TO MAYBE CLOSE TO AN
INCH AND A HALF/TWO INCH RANGE FOR SOME LOCATIONS. THE SYSTEM WILL
BE FAST MOVING AND GENERALLY TO THE EAST BY THE MORNING.
THE COOLING TREND WILL CONTINUE INTO THE WEEKEND UNDER GENERAL
NORTHWEST FLOW. THE NEXT WIGGLE IN THE FLOW WILL COME SHOOTING
ACROSS THE DAKOTAS AND BRING THE CHANCE OF SNOW TO THE ILLINOIS AND
WISCONSIN BORDER OVERNIGHT TOMORROW. MOISTURE IS LACKING WITH THIS
SYSTEM AND GENERALLY ANTICIPATING A DUSTING TO A SMIDGEN MORE FARTHER
NORTH...TYPICALLY NORTH OF THE I-88 DIVISION LINE. WITH FAIRLY FRESH
SNOW...AND ON AND OFF CLOUDS THROUGH THE WEEKEND...ONLY EXPECTING
TEMPERATURES TO DECREASE SLIGHTLY AND NOT NOSEDIVE. SUNDAY HIGHS
WILL GENERALLY RANGE FROM THE LOWER 30S TO MIDDLE 20S...WITH
OVERNIGHT LOWS 10 OR SO DEGREES BELOW THE AFTERNOON HIGHS.
THE EXTENDED FORECAST IS STILL MODERATELY LOW WITH RESPECT TO
OVERALL CONFIDENCE. ANOTHER WEAK CLIPPER WILL SLIDE ACROSS WISCONSIN
MONDAY AND BRUSH THE EXTREME NORTHERN COUNTIES. BUT THERE ARE STILL
CONSIDERABLE DIFFERENCES BETWEEN THE EC AND GFS...WITH THE GFS BEING
A LITTLE MORE BULLISH WITH THE 00Z RUN. THE BIGGEST ISSUE IN
ADJUSTING POPS UP OR DOWN IS THE FACT THAT THE GFS HAS BEEN FLOPPING
EVERY RUN WITH WHERE THE BEST AXIS LINES UP...AND THE ECMWF REMAINS
CONSISTENT AND MOVES THE NEXT SYSTEM THROUGH OUR AREA COMPLETELY
DRY. TRENDS BEYOND INDICATE A DECENT THERMAL RIDGE ALOFT BUILDING
IN FROM THE WEST...BRINGING HIGHS TUESDAY AND INTO WEDNESDAY INTO
THE MIDDLE AND UPPER 40S...TO EVEN LOWER 50S SOUTH. BY THE
EVENING...A SYSTEM WILL IMPACT THE REGION. THE DIFFERENCES AT 120
HOURS OUT ARE FROM DRY /ECMWF/ TO WET /GFS/ AND ENSEMBLE GUIDANCE
LEAVES CONFIDENCE TO GAIN. FOR NOW...WILL LEAVE ONLY CONTINUE WITH
A SLIGHTS MENTION.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* ACCUMULATING SNOW WITH TEMPORARY VISIBILITY UNDER 1SM TONIGHT.
* INCREASING GUSTY WINDS TONIGHT AFTER 03Z FROM THE WEST SOUTHWEST
BECOMING NORTHWEST INTO SATURDAY. WIND GUSTS TO 30 KTS POSSIBLE
SATURDAY.
RATZER
//DISCUSSION...UPDATED 18Z...
SURFACE HIGH PRESSURE RIDGE MOVING ACROSS THE FORECAST AREA THIS
AFTERNOON...ALLOWING LIGHT NORTHWEST WINDS TO BACK SOUTHWEST. NEXT
WEATHER SYSTEM QUICKLY APPROACHING HOWEVER...IN THE FORM OF MID
LEVEL DISTURBANCE TRACKING SOUTHEAST OUT OF THE DAKOTAS AND
MISSOURI VALLEY REGION. SNOW ALREADY SPREADING ACROSS WESTERN AND
PARTS OF CENTRAL IOWA AT THIS HOUR...AND WILL CONTINUE TO SPREAD
INTO ILLINOIS THIS EVENING. PREVIOUS FORECAST APPEARS TO HAVE THIS
WELL IN HAND...WITH LITTLE OVERALL CHANGE NOTED IN 12Z MODEL RUNS.
IF ANYTHING...MAY HAVE TO WATCH FOR A LITTLE EARLIER ONSET. SYSTEM
MOVES THROUGH QUICKLY OVERNIGHT...WITH PERHAPS AN INCH OR SO OF
ACCUMULATION AND A BRIEF PERIOD OF IFR VSBY A LITTLE LESS THAN A
MILE. SNOW SHOULD BE EXITING STAGE RIGHT PRIOR TO SUNRISE
SATURDAY...WITH CEILINGS SCATTERING OUT RATHER QUICKLY DURING THE
EARLY MORNING HOURS.
AFTER THE SNOW...WINDS WILL BECOME GUSTY FROM THE WEST-NORTHWEST
SATURDAY MORNING AS COLDER AIR PUSHES INTO THE REGION. BETWEEN A
RELATIVELY TIGHT PRESSURE GRADIENT AND DEEP MIXING DUE TO COLD
ADVECTION...FORECAST SOUNDINGS INDICATE WINDS GUSTING TO 30 KTS BY
LATE MORNING/MIDDAY.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN ACCUMULATING SNOW WITH AT LEAST TEMPORARY
VISIBILITY AT OR JUST UNDER ONE MILE TONIGHT. MEDIUM CONFIDENCE
IN EXACT TIMING.
* HIGH CONFIDENCE IN WIND TRENDS.
RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...SLIGHT CHANCE OF A DUSTING SNOWFALL OVERNIGHT.
MVFR LIKELY.
SUNDAY...MORNING MVFR THEN CLEARING.
MONDAY...VFR,
TUESDAY...SLIGHT CHANCE OF RAIN...POSSIBLY MIXED WITH SNOW EARLY
AND AGAIN LATE AT NIGHT. IFR POSSIBLE.
WEDNESDAY....MVFR POSSIBLE.
THURSDAY...CHANCE OF SNOW. IFR POSSIBLE.
MTF
&&
.MARINE...
257 PM...ACTIVE PATTERN WITH SEVERAL SYSTEMS TO CONTINUE INTO NEXT
WEEK. LOW PRESSURE OVER MN THIS AFTERNOON WILL MOVE EAST AND CROSS
NORTHERN LAKE MICHIGAN LATE TONIGHT INTO EARLY SATURDAY MORNING.
THIS LOW IS RIDING A COLD FRONT TRAILING A MUCH STRONGER LOW NEAR
HUDSON BAY. AS THIS LOW AND ASSOCIATED FRONT APPROACH THE LAKE
THIS EVENING WESTERLY WINDS WILL SHIFT SOUTHWESTERLY AND STEADILY
INCREASE...THEN SHIFT WESTERLY AS THE FRONT ARRIVES BEFORE SUNRISE
SATURDAY. COLDER AIR SPREADING ACROSS THE REGION COMBINED WITH A
TIGHTENING GRADIENT SHOULD ALLOW GALES TO DEVELOP AROUND SUNRISE
ACROSS THE SOUTHERN HALF OR SO OF THE LAKE. WHILE THE GRADIENT
DOES TIGHTEN OVER NORTHERN LAKE MICHIGAN...IT APPEARS WINDS WILL
ONLY INCREASE TO 30 KTS OR SO. THE GRADIENT THEN RELAXES SOME
SATURDAY EVENING...AS ANOTHER WEAK LOW DEVELOPS OVER WI SATURDAY
EVENING. THIS LOW WILL MOVE ACROSS NORTH/CENTRAL LAKE MICHIGAN
EARLY SUNDAY MORNING WITH ANOTHER PERIOD OF STRONGER WINDS...
PERHAPS UP TO 30 KTS ON THE BACK SIDE OF THIS LOW ON SUNDAY.
ANOTHER FAST MOVING RIDGE MOVES ACROSS THE WESTERN LAKES SUNDAY
EVENING...AS ANOTHER STRONG LOW MOVES ACROSS THE UPPER MIDWEST AND
NORTHERN LAKES MONDAY AFTERNOON INTO MONDAY NIGHT. SOUTHERLY WINDS
WILL INCREASE MONDAY...AHEAD OF THIS LOW. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-
LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...4 AM SATURDAY TO 6 PM
SATURDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
202 PM CST FRI JAN 27 2012
.DISCUSSION...
333 AM CST
FOR TODAY...CLOUDS ON THE BACKSIDE OF THE LOW THAT IS LIFTING OUT OF
THE OHIO VALLEY...WILL CONTINUE TO CHARGE TO THE SOUTHEAST. AIRCRAFT
SOUNDINGS OUT OF ORD SHOW A FAIRLY SHALLOW SATURATED LAYER REMAINING.
UPSTREAM SOUNDINGS AND RUC ANALYSIS SHOW AN OVERALL DRYING TREND
TO CONTINUE AND NOT EXPECTING ANY EXPANSION TO THE CLOUDS EARLY
THIS MORNING. MOST LOCATIONS SHOULD SEE MOSTLY SUNNY AND BLUE
SKIES...WITH THE EXCEPTION OF THE FAR SOUTHEAST WHERE THEY WILL BE
SLUGGISH. BOTH THE RUC AND NARRE-TL GUIDANCE ARE IN AGREEMENT THAT
THE NORTHWEST SHOULD BE CLEAR BY SUNRISE...WITH THE CHICAGO METRO
A FEW HOURS BEYOND. FAST ON THE HEELS OF THE CLEAR SKIES WILL BE
MID LEVEL CLOUDS ARRIVING FROM THE WEST WITH THE NEXT WAVE MOVING
IN...AND THE ENTIRE CWA IS THEN EXPECTED TO BECOME CLOUDY AGAIN
BY THE EARLY TO MID AFTERNOON. WITH NO REAL CHANGE TO THE AIRMASS
TODAY AND TONIGHT...TEMPERATURES ARE EXPECTED TO BE CLOSE TO
CARBON COPIES OF YESTERDAY. FOCUS IN THE EVENING WILL THEN TURN
TOWARDS THE WEST AS A WEAK CLIPPER /THAT IS NOTED ON REGIONAL
RADAR THIS MORNING ACROSS THE NORTHERN DAKOTAS/ AND A WEAK
SOUTHERN STREAM SYSTEM /NEAR THE OKLAHOMA PAN HANDLE THIS MORNING/
SHIFT EAST AND NOT QUITE MERGE...RATHER COMPLICATE THE EVENING
FORECAST. THE GOOD NEWS IS THAT THE TIMING SHOULD BE AS RUSH HOUR
COMES TO A CLOSE FOR THE FAR NORTHWEST...AND HOURS BEYOND THE
CHICAGO METRO RUSH.
THE OVERALL PICTURE HAS BEEN PRETTY CONSISTENT THE LAST FEW DAYS
THAT ANYWHERE FROM AN INCH TO INCH AND A HALF OF SNOW ARE EXPECTED
WITH THIS SYSTEM. THE EARLIER 18/00Z GUIDANCE SEEMED TO BE IN DECENT
AGREEMENT WITH KEEPING THE BEST FORCING NORTH AND HAVING A BIT MORE
OF A UNIFORM TOTAL ACROSS THE AREA...WITH POTENTIALLY HIGHER AMOUNTS
NORTH OF I-80...BUT THE 00Z GFS AND ECMWF BEGAN TO THROW A WRENCH
AND GIVE THE SOUTHERN SECTION A LITTLE MORE GUSTO THAN PREVIOUS
RUNS...MAKING THE SNOW FALL A LITTLE MORE DISJOINTED. WITH DRY AIR
INVADING THE REGION THIS MORNING...IT WILL TAKE SOME TIME TO
SATURATE THE COLUMN BEFORE IT PRECIPITATES TO THE GROUND. THE OTHER
QUESTION WILL BE ON WHAT FORM THE PRECIP WILL BE AT THE ONSET.
FORECAST SOUNDINGS ARE TRYING TO HOLD ONTO SURFACE TEMPERATURES AT
OR SLIGHTLY ABOVE FREEZING THROUGH ROUGHLY 9 TO 10 PM
TONIGHT...CONTINUING TO COOL BEYOND AND INTO THE OVERNIGHT HOURS.
SIMPLE CROSS HAIRS TECHNIQUE SHOWS THE HIGHEST OMEGA VALUES
INTERSECTING THE DGZ IN A 2 OR SO HOUR WINDOW...AND GENERALLY IN THE
3-4-5Z TIME FRAME. IT IS WITHIN THIS WINDOW THAT THE BEST
ACCUMULATION SHOULD HAPPEN...BUT NOT ANTICIPATING MUCH BEYOND A HALF
INCH AN HOUR RATE WHEN THE ATMOSPHERE IS MOST EFFICIENT...AND WILL
LIKELY START AS A HEAVIER/WET SNOW. STILL CONFIDENT THAT THE
TOTALS WILL BE LOW AND IN THE GENERAL INCH TO MAYBE CLOSE TO AN
INCH AND A HALF/TWO INCH RANGE FOR SOME LOCATIONS. THE SYSTEM WILL
BE FAST MOVING AND GENERALLY TO THE EAST BY THE MORNING.
THE COOLING TREND WILL CONTINUE INTO THE WEEKEND UNDER GENERAL
NORTHWEST FLOW. THE NEXT WIGGLE IN THE FLOW WILL COME SHOOTING
ACROSS THE DAKOTAS AND BRING THE CHANCE OF SNOW TO THE ILLINOIS AND
WISCONSIN BORDER OVERNIGHT TOMORROW. MOISTURE IS LACKING WITH THIS
SYSTEM AND GENERALLY ANTICIPATING A DUSTING TO A SMIDGEN MORE FARTHER
NORTH...TYPICALLY NORTH OF THE I-88 DIVISION LINE. WITH FAIRLY FRESH
SNOW...AND ON AND OFF CLOUDS THROUGH THE WEEKEND...ONLY EXPECTING
TEMPERATURES TO DECREASE SLIGHTLY AND NOT NOSEDIVE. SUNDAY HIGHS
WILL GENERALLY RANGE FROM THE LOWER 30S TO MIDDLE 20S...WITH
OVERNIGHT LOWS 10 OR SO DEGREES BELOW THE AFTERNOON HIGHS.
THE EXTENDED FORECAST IS STILL MODERATELY LOW WITH RESPECT TO
OVERALL CONFIDENCE. ANOTHER WEAK CLIPPER WILL SLIDE ACROSS WISCONSIN
MONDAY AND BRUSH THE EXTREME NORTHERN COUNTIES. BUT THERE ARE STILL
CONSIDERABLE DIFFERENCES BETWEEN THE EC AND GFS...WITH THE GFS BEING
A LITTLE MORE BULLISH WITH THE 00Z RUN. THE BIGGEST ISSUE IN
ADJUSTING POPS UP OR DOWN IS THE FACT THAT THE GFS HAS BEEN FLOPPING
EVERY RUN WITH WHERE THE BEST AXIS LINES UP...AND THE ECMWF REMAINS
CONSISTENT AND MOVES THE NEXT SYSTEM THROUGH OUR AREA COMPLETELY
DRY. TRENDS BEYOND INDICATE A DECENT THERMAL RIDGE ALOFT BUILDING
IN FROM THE WEST...BRINGING HIGHS TUESDAY AND INTO WEDNESDAY INTO
THE MIDDLE AND UPPER 40S...TO EVEN LOWER 50S SOUTH. BY THE
EVENING...A SYSTEM WILL IMPACT THE REGION. THE DIFFERENCES AT 120
HOURS OUT ARE FROM DRY /ECMWF/ TO WET /GFS/ AND ENSEMBLE GUIDANCE
LEAVES CONFIDENCE TO GAIN. FOR NOW...WILL LEAVE ONLY CONTINUE WITH
A SLIGHTS MENTION.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* ACCUMULATING SNOW WITH TEMPORARY VISIBILITY UNDER 1SM TONIGHT.
* INCREASING GUSTY WINDS TONIGHT AFTER 03Z FROM THE WEST SOUTHWEST
BECOMING NORTHWEST INTO SATURDAY. WIND GUSTS TO 30 KTS POSSIBLE
SATURDAY.
RATZER
//DISCUSSION...UPDATED 18Z...
SURFACE HIGH PRESSURE RIDGE MOVING ACROSS THE FORECAST AREA THIS
AFTERNOON...ALLOWING LIGHT NORTHWEST WINDS TO BACK SOUTHWEST. NEXT
WEATHER SYSTEM QUICKLY APPROACHING HOWEVER...IN THE FORM OF MID
LEVEL DISTURBANCE TRACKING SOUTHEAST OUT OF THE DAKOTAS AND
MISSOURI VALLEY REGION. SNOW ALREADY SPREADING ACROSS WESTERN AND
PARTS OF CENTRAL IOWA AT THIS HOUR...AND WILL CONTINUE TO SPREAD
INTO ILLINOIS THIS EVENING. PREVIOUS FORECAST APPEARS TO HAVE THIS
WELL IN HAND...WITH LITTLE OVERALL CHANGE NOTED IN 12Z MODEL RUNS.
IF ANYTHING...MAY HAVE TO WATCH FOR A LITTLE EARLIER ONSET. SYSTEM
MOVES THROUGH QUICKLY OVERNIGHT...WITH PERHAPS AN INCH OR SO OF
ACCUMULATION AND A BRIEF PERIOD OF IFR VSBY A LITTLE LESS THAN A
MILE. SNOW SHOULD BE EXITING STAGE RIGHT PRIOR TO SUNRISE
SATURDAY...WITH CEILINGS SCATTERING OUT RATHER QUICKLY DURING THE
EARLY MORNING HOURS.
AFTER THE SNOW...WINDS WILL BECOME GUSTY FROM THE WEST-NORTHWEST
SATURDAY MORNING AS COLDER AIR PUSHES INTO THE REGION. BETWEEN A
RELATIVELY TIGHT PRESSURE GRADIENT AND DEEP MIXING DUE TO COLD
ADVECTION...FORECAST SOUNDINGS INDICATE WINDS GUSTING TO 30 KTS BY
LATE MORNING/MIDDAY.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN ACCUMULATING SNOW WITH AT LEAST TEMPORARY
VISIBILITY AT OR JUST UNDER ONE MILE TONIGHT. MEDIUM CONFIDENCE
IN EXACT TIMING.
* HIGH CONFIDENCE IN WIND TRENDS.
RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...SLIGHT CHANCE OF A DUSTING SNOWFALL OVERNIGHT.
MVFR LIKELY.
SUNDAY...MORNING MVFR THEN CLEARING.
MONDAY...VFR,
TUESDAY...SLIGHT CHANCE OF RAIN...POSSIBLY MIXED WITH SNOW EARLY
AND AGAIN LATE AT NIGHT. IFR POSSIBLE.
WEDNESDAY....MVFR POSSIBLE.
THURSDAY...CHANCE OF SNOW. IFR POSSIBLE.
MTF
&&
.MARINE...
420 AM CST
AN ACTIVE PATTERN MEANS MULTIPLE LOWS WILL BE MOVING ACROSS
SOUTHERN CANADA AND THE NORTHERN STATES. THIS WILL RESULT IN
REPEATED COLD FRONTAL PASSAGES ACROSS LAKE MI OVER THE NEXT
SEVERAL DAYS.
MODERATELY STRONG NW WINDS THIS MORNING WILL DIMINISH AND BACK TO
OUT OF THE SW AS A RIDGE OF HIGH PRESSURE SLIDES E TO THE UPPER
GREAT LAKES AND LOWER OH VALLEY BY THIS EVENING. WINDS WILL
INCREASE TONIGHT AS A LOW AND COLD FRONT MOVE E INTO THE WESTERN
GREAT LAKES OVERNIGHT.
ANOTHER LOW WILL DROP SE OVER NORTHERN MN BY SAT EVENING. AS IT
CONTINUES ON TO LOWER MI BY DAWN SUN...IT WILL SWEEP ANOTHER COLD
FRONT ACROSS LAKE MI. THIS LOW MOVES E TO NEAR LAKE ONTARIO BY
LATE SUN ALLOWING A RIDGE OF HIGH PRES TO SLIDE E TO THE UPPER
MIDWEST AND MID MS VALLEY SUN. IT CONTINUES MOVING ACROSS THE
UPPER GREAT LAKES TO THE LOWER LAKES AND UPPER OH VALLEY BY MON
MORNING.
YET ANOTHER LOW WILL BE MOVING ACROSS NORTHERN MN AND LAKE
SUPERIOR TUE...BRINGING ANOTHER COLD FRONT ACROSS LAKE MI.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE BURNS HARBOR TO MICHIGAN CITY IN UNTIL 3 PM FRIDAY.
GALE WARNING...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-
LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...4 AM SATURDAY TO 6 PM
SATURDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1117 AM CST FRI JAN 27 2012
.DISCUSSION...
333 AM CST
FOR TODAY...CLOUDS ON THE BACKSIDE OF THE LOW THAT IS LIFTING OUT OF
THE OHIO VALLEY...WILL CONTINUE TO CHARGE TO THE SOUTHEAST. AIRCRAFT
SOUNDINGS OUT OF ORD SHOW A FAIRLY SHALLOW SATURATED LAYER REMAINING.
UPSTREAM SOUNDINGS AND RUC ANALYSIS SHOW AN OVERALL DRYING TREND
TO CONTINUE AND NOT EXPECTING ANY EXPANSION TO THE CLOUDS EARLY
THIS MORNING. MOST LOCATIONS SHOULD SEE MOSTLY SUNNY AND BLUE
SKIES...WITH THE EXCEPTION OF THE FAR SOUTHEAST WHERE THEY WILL BE
SLUGGISH. BOTH THE RUC AND NARRE-TL GUIDANCE ARE IN AGREEMENT THAT
THE NORTHWEST SHOULD BE CLEAR BY SUNRISE...WITH THE CHICAGO METRO
A FEW HOURS BEYOND. FAST ON THE HEELS OF THE CLEAR SKIES WILL BE
MID LEVEL CLOUDS ARRIVING FROM THE WEST WITH THE NEXT WAVE MOVING
IN...AND THE ENTIRE CWA IS THEN EXPECTED TO BECOME CLOUDY AGAIN
BY THE EARLY TO MID AFTERNOON. WITH NO REAL CHANGE TO THE AIRMASS
TODAY AND TONIGHT...TEMPERATURES ARE EXPECTED TO BE CLOSE TO
CARBON COPIES OF YESTERDAY. FOCUS IN THE EVENING WILL THEN TURN
TOWARDS THE WEST AS A WEAK CLIPPER /THAT IS NOTED ON REGIONAL
RADAR THIS MORNING ACROSS THE NORTHERN DAKOTAS/ AND A WEAK
SOUTHERN STREAM SYSTEM /NEAR THE OKLAHOMA PAN HANDLE THIS MORNING/
SHIFT EAST AND NOT QUITE MERGE...RATHER COMPLICATE THE EVENING
FORECAST. THE GOOD NEWS IS THAT THE TIMING SHOULD BE AS RUSH HOUR
COMES TO A CLOSE FOR THE FAR NORTHWEST...AND HOURS BEYOND THE
CHICAGO METRO RUSH.
THE OVERALL PICTURE HAS BEEN PRETTY CONSISTENT THE LAST FEW DAYS
THAT ANYWHERE FROM AN INCH TO INCH AND A HALF OF SNOW ARE EXPECTED
WITH THIS SYSTEM. THE EARLIER 18/00Z GUIDANCE SEEMED TO BE IN DECENT
AGREEMENT WITH KEEPING THE BEST FORCING NORTH AND HAVING A BIT MORE
OF A UNIFORM TOTAL ACROSS THE AREA...WITH POTENTIALLY HIGHER AMOUNTS
NORTH OF I-80...BUT THE 00Z GFS AND ECMWF BEGAN TO THROW A WRENCH
AND GIVE THE SOUTHERN SECTION A LITTLE MORE GUSTO THAN PREVIOUS
RUNS...MAKING THE SNOW FALL A LITTLE MORE DISJOINTED. WITH DRY AIR
INVADING THE REGION THIS MORNING...IT WILL TAKE SOME TIME TO
SATURATE THE COLUMN BEFORE IT PRECIPITATES TO THE GROUND. THE OTHER
QUESTION WILL BE ON WHAT FORM THE PRECIP WILL BE AT THE ONSET.
FORECAST SOUNDINGS ARE TRYING TO HOLD ONTO SURFACE TEMPERATURES AT
OR SLIGHTLY ABOVE FREEZING THROUGH ROUGHLY 9 TO 10 PM
TONIGHT...CONTINUING TO COOL BEYOND AND INTO THE OVERNIGHT HOURS.
SIMPLE CROSS HAIRS TECHNIQUE SHOWS THE HIGHEST OMEGA VALUES
INTERSECTING THE DGZ IN A 2 OR SO HOUR WINDOW...AND GENERALLY IN THE
3-4-5Z TIME FRAME. IT IS WITHIN THIS WINDOW THAT THE BEST
ACCUMULATION SHOULD HAPPEN...BUT NOT ANTICIPATING MUCH BEYOND A HALF
INCH AN HOUR RATE WHEN THE ATMOSPHERE IS MOST EFFICIENT...AND WILL
LIKELY START AS A HEAVIER/WET SNOW. STILL CONFIDENT THAT THE
TOTALS WILL BE LOW AND IN THE GENERAL INCH TO MAYBE CLOSE TO AN
INCH AND A HALF/TWO INCH RANGE FOR SOME LOCATIONS. THE SYSTEM WILL
BE FAST MOVING AND GENERALLY TO THE EAST BY THE MORNING.
THE COOLING TREND WILL CONTINUE INTO THE WEEKEND UNDER GENERAL
NORTHWEST FLOW. THE NEXT WIGGLE IN THE FLOW WILL COME SHOOTING
ACROSS THE DAKOTAS AND BRING THE CHANCE OF SNOW TO THE ILLINOIS AND
WISCONSIN BORDER OVERNIGHT TOMORROW. MOISTURE IS LACKING WITH THIS
SYSTEM AND GENERALLY ANTICIPATING A DUSTING TO A SMIDGEN MORE FARTHER
NORTH...TYPICALLY NORTH OF THE I-88 DIVISION LINE. WITH FAIRLY FRESH
SNOW...AND ON AND OFF CLOUDS THROUGH THE WEEKEND...ONLY EXPECTING
TEMPERATURES TO DECREASE SLIGHTLY AND NOT NOSEDIVE. SUNDAY HIGHS
WILL GENERALLY RANGE FROM THE LOWER 30S TO MIDDLE 20S...WITH
OVERNIGHT LOWS 10 OR SO DEGREES BELOW THE AFTERNOON HIGHS.
THE EXTENDED FORECAST IS STILL MODERATELY LOW WITH RESPECT TO
OVERALL CONFIDENCE. ANOTHER WEAK CLIPPER WILL SLIDE ACROSS WISCONSIN
MONDAY AND BRUSH THE EXTREME NORTHERN COUNTIES. BUT THERE ARE STILL
CONSIDERABLE DIFFERENCES BETWEEN THE EC AND GFS...WITH THE GFS BEING
A LITTLE MORE BULLISH WITH THE 00Z RUN. THE BIGGEST ISSUE IN
ADJUSTING POPS UP OR DOWN IS THE FACT THAT THE GFS HAS BEEN FLOPPING
EVERY RUN WITH WHERE THE BEST AXIS LINES UP...AND THE ECMWF REMAINS
CONSISTENT AND MOVES THE NEXT SYSTEM THROUGH OUR AREA COMPLETELY
DRY. TRENDS BEYOND INDICATE A DECENT THERMAL RIDGE ALOFT BUILDING
IN FROM THE WEST...BRINGING HIGHS TUESDAY AND INTO WEDNESDAY INTO
THE MIDDLE AND UPPER 40S...TO EVEN LOWER 50S SOUTH. BY THE
EVENING...A SYSTEM WILL IMPACT THE REGION. THE DIFFERENCES AT 120
HOURS OUT ARE FROM DRY /ECMWF/ TO WET /GFS/ AND ENSEMBLE GUIDANCE
LEAVES CONFIDENCE TO GAIN. FOR NOW...WILL LEAVE ONLY CONTINUE WITH
A SLIGHTS MENTION.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* ACCUMULATING SNOW WITH TEMPORARY VISIBILITY UNDER 1SM TONIGHT.
* INCREASING GUSTY WINDS TONIGHT AFTER 03Z FROM THE WEST SOUTHWEST
BECOMING NORTHWEST INTO SATURDAY. WIND GUSTS TO 30 KTS POSSIBLE
SATURDAY.
RATZER
//DISCUSSION...UPDATED 18Z...
SURFACE HIGH PRESSURE RIDGE MOVING ACROSS THE FORECAST AREA THIS
AFTERNOON...ALLOWING LIGHT NORTHWEST WINDS TO BACK SOUTHWEST. NEXT
WEATHER SYSTEM QUICKLY APPROACHING HOWEVER...IN THE FORM OF MID
LEVEL DISTURBANCE TRACKING SOUTHEAST OUT OF THE DAKOTAS AND
MISSOURI VALLEY REGION. SNOW ALREADY SPREADING ACROSS WESTERN AND
PARTS OF CENTRAL IOWA AT THIS HOUR...AND WILL CONTINUE TO SPREAD
INTO ILLINOIS THIS EVENING. PREVIOUS FORECAST APPEARS TO HAVE THIS
WELL IN HAND...WITH LITTLE OVERALL CHANGE NOTED IN 12Z MODEL RUNS.
IF ANYTHING...MAY HAVE TO WATCH FOR A LITTLE EARLIER ONSET. SYSTEM
MOVES THROUGH QUICKLY OVERNIGHT...WITH PERHAPS AN INCH OR SO OF
ACCUMULATION AND A BRIEF PERIOD OF IFR VSBY A LITTLE LESS THAN A
MILE. SNOW SHOULD BE EXITING STAGE RIGHT PRIOR TO SUNRISE
SATURDAY...WITH CEILINGS SCATTERING OUT RATHER QUICKLY DURING THE
EARLY MORNING HOURS.
AFTER THE SNOW...WINDS WILL BECOME GUSTY FROM THE WEST-NORTHWEST
SATURDAY MORNING AS COLDER AIR PUSHES INTO THE REGION. BETWEEN A
RELATIVELY TIGHT PRESSURE GRADIENT AND DEEP MIXING DUE TO COLD
ADVECTION...FORECAST SOUNDINGS INDICATE WINDS GUSTING TO 30 KTS BY
LATE MORNING/MIDDAY.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN ACCUMULATING SNOW WITH AT LEAST TEMPORARY
VISIBILITY AT OR JUST UNDER ONE MILE TONIGHT. MEDIUM CONFIDENCE
IN EXACT TIMING.
* HIGH CONFIDENCE IN WIND TRENDS.
RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...SLIGHT CHANCE OF A DUSTING SNOWFALL OVERNIGHT.
MVFR LIKELY.
SUNDAY...MORNING MVFR THEN CLEARING.
MONDAY...VFR,
TUESDAY...SLIGHT CHANCE OF RAIN...POSSIBLY MIXED WITH SNOW EARLY
AND AGAIN LATE AT NIGHT. IFR POSSIBLE.
WEDNESDAY....MVFR POSSIBLE.
THURSDAY...CHANCE OF SNOW. IFR POSSIBLE.
MTF
&&
.MARINE...
420 AM CST
AN ACTIVE PATTERN MEANS MULTIPLE LOWS WILL BE MOVING ACROSS
SOUTHERN CANADA AND THE NORTHERN STATES. THIS WILL RESULT IN
REPEATED COLD FRONTAL PASSAGES ACROSS LAKE MI OVER THE NEXT
SEVERAL DAYS.
MODERATELY STRONG NW WINDS THIS MORNING WILL DIMINISH AND BACK TO
OUT OF THE SW AS A RIDGE OF HIGH PRESSURE SLIDES E TO THE UPPER
GREAT LAKES AND LOWER OH VALLEY BY THIS EVENING. WINDS WILL
INCREASE TONIGHT AS A LOW AND COLD FRONT MOVE E INTO THE WESTERN
GREAT LAKES OVERNIGHT.
ANOTHER LOW WILL DROP SE OVER NORTHERN MN BY SAT EVENING. AS IT
CONTINUES ON TO LOWER MI BY DAWN SUN...IT WILL SWEEP ANOTHER COLD
FRONT ACROSS LAKE MI. THIS LOW MOVES E TO NEAR LAKE ONTARIO BY
LATE SUN ALLOWING A RIDGE OF HIGH PRES TO SLIDE E TO THE UPPER
MIDWEST AND MID MS VALLEY SUN. IT CONTINUES MOVING ACROSS THE
UPPER GREAT LAKES TO THE LOWER LAKES AND UPPER OH VALLEY BY MON
MORNING.
YET ANOTHER LOW WILL BE MOVING ACROSS NORTHERN MN AND LAKE
SUPERIOR TUE...BRINGING ANOTHER COLD FRONT ACROSS LAKE MI.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE BURNS HARBOR TO MICHIGAN CITY IN UNTIL 3 PM FRIDAY.
GALE WATCH...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-
LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...6 AM SATURDAY TO 6 PM
SATURDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1011 AM CST FRI JAN 27 2012
.DISCUSSION...
333 AM CST
FOR TODAY...CLOUDS ON THE BACKSIDE OF THE LOW THAT IS LIFTING OUT OF
THE OHIO VALLEY...WILL CONTINUE TO CHARGE TO THE SOUTHEAST. AIRCRAFT
SOUNDINGS OUT OF ORD SHOW A FAIRLY SHALLOW SATURATED LAYER REMAINING.
UPSTREAM SOUNDINGS AND RUC ANALYSIS SHOW AN OVERALL DRYING TREND
TO CONTINUE AND NOT EXPECTING ANY EXPANSION TO THE CLOUDS EARLY
THIS MORNING. MOST LOCATIONS SHOULD SEE MOSTLY SUNNY AND BLUE
SKIES...WITH THE EXCEPTION OF THE FAR SOUTHEAST WHERE THEY WILL BE
SLUGGISH. BOTH THE RUC AND NARRE-TL GUIDANCE ARE IN AGREEMENT THAT
THE NORTHWEST SHOULD BE CLEAR BY SUNRISE...WITH THE CHICAGO METRO
A FEW HOURS BEYOND. FAST ON THE HEELS OF THE CLEAR SKIES WILL BE
MID LEVEL CLOUDS ARRIVING FROM THE WEST WITH THE NEXT WAVE MOVING
IN...AND THE ENTIRE CWA IS THEN EXPECTED TO BECOME CLOUDY AGAIN
BY THE EARLY TO MID AFTERNOON. WITH NO REAL CHANGE TO THE AIRMASS
TODAY AND TONIGHT...TEMPERATURES ARE EXPECTED TO BE CLOSE TO
CARBON COPIES OF YESTERDAY. FOCUS IN THE EVENING WILL THEN TURN
TOWARDS THE WEST AS A WEAK CLIPPER /THAT IS NOTED ON REGIONAL
RADAR THIS MORNING ACROSS THE NORTHERN DAKOTAS/ AND A WEAK
SOUTHERN STREAM SYSTEM /NEAR THE OKLAHOMA PAN HANDLE THIS MORNING/
SHIFT EAST AND NOT QUITE MERGE...RATHER COMPLICATE THE EVENING
FORECAST. THE GOOD NEWS IS THAT THE TIMING SHOULD BE AS RUSH HOUR
COMES TO A CLOSE FOR THE FAR NORTHWEST...AND HOURS BEYOND THE
CHICAGO METRO RUSH.
THE OVERALL PICTURE HAS BEEN PRETTY CONSISTENT THE LAST FEW DAYS
THAT ANYWHERE FROM AN INCH TO INCH AND A HALF OF SNOW ARE EXPECTED
WITH THIS SYSTEM. THE EARLIER 18/00Z GUIDANCE SEEMED TO BE IN DECENT
AGREEMENT WITH KEEPING THE BEST FORCING NORTH AND HAVING A BIT MORE
OF A UNIFORM TOTAL ACROSS THE AREA...WITH POTENTIALLY HIGHER AMOUNTS
NORTH OF I-80...BUT THE 00Z GFS AND ECMWF BEGAN TO THROW A WRENCH
AND GIVE THE SOUTHERN SECTION A LITTLE MORE GUSTO THAN PREVIOUS
RUNS...MAKING THE SNOW FALL A LITTLE MORE DISJOINTED. WITH DRY AIR
INVADING THE REGION THIS MORNING...IT WILL TAKE SOME TIME TO
SATURATE THE COLUMN BEFORE IT PRECIPITATES TO THE GROUND. THE OTHER
QUESTION WILL BE ON WHAT FORM THE PRECIP WILL BE AT THE ONSET.
FORECAST SOUNDINGS ARE TRYING TO HOLD ONTO SURFACE TEMPERATURES AT
OR SLIGHTLY ABOVE FREEZING THROUGH ROUGHLY 9 TO 10 PM
TONIGHT...CONTINUING TO COOL BEYOND AND INTO THE OVERNIGHT HOURS.
SIMPLE CROSS HAIRS TECHNIQUE SHOWS THE HIGHEST OMEGA VALUES
INTERSECTING THE DGZ IN A 2 OR SO HOUR WINDOW...AND GENERALLY IN THE
3-4-5Z TIME FRAME. IT IS WITHIN THIS WINDOW THAT THE BEST
ACCUMULATION SHOULD HAPPEN...BUT NOT ANTICIPATING MUCH BEYOND A HALF
INCH AN HOUR RATE WHEN THE ATMOSPHERE IS MOST EFFICIENT...AND WILL
LIKELY START AS A HEAVIER/WET SNOW. STILL CONFIDENT THAT THE
TOTALS WILL BE LOW AND IN THE GENERAL INCH TO MAYBE CLOSE TO AN
INCH AND A HALF/TWO INCH RANGE FOR SOME LOCATIONS. THE SYSTEM WILL
BE FAST MOVING AND GENERALLY TO THE EAST BY THE MORNING.
THE COOLING TREND WILL CONTINUE INTO THE WEEKEND UNDER GENERAL
NORTHWEST FLOW. THE NEXT WIGGLE IN THE FLOW WILL COME SHOOTING
ACROSS THE DAKOTAS AND BRING THE CHANCE OF SNOW TO THE ILLINOIS AND
WISCONSIN BORDER OVERNIGHT TOMORROW. MOISTURE IS LACKING WITH THIS
SYSTEM AND GENERALLY ANTICIPATING A DUSTING TO A SMIDGEN MORE FARTHER
NORTH...TYPICALLY NORTH OF THE I-88 DIVISION LINE. WITH FAIRLY FRESH
SNOW...AND ON AND OFF CLOUDS THROUGH THE WEEKEND...ONLY EXPECTING
TEMPERATURES TO DECREASE SLIGHTLY AND NOT NOSEDIVE. SUNDAY HIGHS
WILL GENERALLY RANGE FROM THE LOWER 30S TO MIDDLE 20S...WITH
OVERNIGHT LOWS 10 OR SO DEGREES BELOW THE AFTERNOON HIGHS.
THE EXTENDED FORECAST IS STILL MODERATELY LOW WITH RESPECT TO
OVERALL CONFIDENCE. ANOTHER WEAK CLIPPER WILL SLIDE ACROSS WISCONSIN
MONDAY AND BRUSH THE EXTREME NORTHERN COUNTIES. BUT THERE ARE STILL
CONSIDERABLE DIFFERENCES BETWEEN THE EC AND GFS...WITH THE GFS BEING
A LITTLE MORE BULLISH WITH THE 00Z RUN. THE BIGGEST ISSUE IN
ADJUSTING POPS UP OR DOWN IS THE FACT THAT THE GFS HAS BEEN FLOPPING
EVERY RUN WITH WHERE THE BEST AXIS LINES UP...AND THE ECMWF REMAINS
CONSISTENT AND MOVES THE NEXT SYSTEM THROUGH OUR AREA COMPLETELY
DRY. TRENDS BEYOND INDICATE A DECENT THERMAL RIDGE ALOFT BUILDING
IN FROM THE WEST...BRINGING HIGHS TUESDAY AND INTO WEDNESDAY INTO
THE MIDDLE AND UPPER 40S...TO EVEN LOWER 50S SOUTH. BY THE
EVENING...A SYSTEM WILL IMPACT THE REGION. THE DIFFERENCES AT 120
HOURS OUT ARE FROM DRY /ECMWF/ TO WET /GFS/ AND ENSEMBLE GUIDANCE
LEAVES CONFIDENCE TO GAIN. FOR NOW...WILL LEAVE ONLY CONTINUE WITH
A SLIGHTS MENTION.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* ACCUMULATING SNOW WITH TEMPORARY VISIBILITY UNDER 1SM TONIGHT.
* INCREASING GUSTY WINDS TONIGHT AFTER 03Z FROM THE WEST SOUTHWEST
BECOMING NORTHWEST INTO SATURDAY. WIND GUSTS TO 30 KTS POSSIBLE
SATURDAY.
RATZER
//DISCUSSION...UPDATED 12Z...
THE DAYTIME PERIOD IS EXPECTED TO BE QUIET AVIATION-WISE
TODAY...BUT SOME CLOUDS PRIOR TO DAYBREAK AND SOME SNOW TONIGHT
ARE THE FORECAST CHALLENGES. THE 020-030 CIGS THIS MORNING WILL
CONTINUE TO DEPART AS A BRIEF AND WEAK HIGH PRESSURE RIDGE AND
DRIER LOW-LEVEL AIR MASS SPREAD INTO THE AREA. WINDS WILL REMAIN
NORTHWEST THIS MORNING BEFORE BACKING TO THE SOUTHWEST FROM 17Z
THROUGH 22Z. AN UPPER LEVEL DISTURBANCE WILL MOVE OVER THE AREA
TONIGHT...LEADING TO SNOWFALL BY MID-EVENING AT ALL TAF SITES. IT
IS POSSIBLE THE START TIME IS SLIGHTLY EARLIER AT EACH AIRPORT
THAN PRESENTLY FORECAST. THE FORCING AND DEEPER MOISTURE FOR SNOW
IS FAIRLY PROGRESSIVE...SO THE WINDOW FOR IFR VISIBILITY AND MVFR
CIGS IN SNOW LOOKS TO BE THREE TO FIVE HOURS. THE CIGS ARE FAVORED
TO LAST SLIGHTLY AFTER THE ACCUMULATING SNOW ENDS...AND SO MIGHT
SOME FLURRIES. TOTAL ACCUMULATION AT AREA TAF SITES IS EXPECTED TO
BE BETWEEN ONE AND TWO INCHES AT THIS TIME...WITH THE SNOW
INITIALLY BEING WET AND THEN BECOMING MORE DRY AS IT WRAPS UP. IN
ADDITION...WINDS WILL BEGIN TO VEER GRADUALLY BACK TOWARDS THE
WEST AND INCREASE IN SPEED ONCE THE SNOW BEGINS THIS EVENING...AND
THEN SHARPLY TO THE NORTHWEST AND BECOME QUITE GUSTY ONCE THE
SYSTEM COLD FRONT PASSES BETWEEN 08Z AND 11Z. SOME SHALLOW BLOWING
SNOW IS LIKELY LATE TONIGHT INTO SATURDAY MORNING. WINDS ARE
FAVORED TO GUST AS HIGH AS 30 KT ON SATURDAY BETWEEN 15Z AND 22Z.
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN ACCUMULATING SNOW WITH AT LEAST TEMPORARY
VISIBILITY AT OR JUST UNDER ONE MILE TONIGHT. MEDIUM CONFIDENCE
IN EXACT TIMING. IT MAY NEED TO BE ADJUSTED AN HOUR EARLIER
DEPENDING ON TRENDS TODAY.
* MEDIUM CONFIDENCE IN WIND TRENDS...BUT HIGH CONFIDENCE IN GUSTS
TO 20 KTS LATE TONIGHT AND TO NEAR 30 KTS BY MID MORNING
SATURDAY.
RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...SLIGHT CHANCE OF A DUSTING SNOWFALL OVERNIGHT.
MVFR LIKELY.
SUNDAY...MORNING MVFR THEN CLEARING.
MONDAY...VFR,
TUESDAY...SLIGHT CHANCE OF RAIN...POSSIBLY MIXED WITH SNOW EARLY
AND AGAIN LATE AT NIGHT. IFR POSSIBLE.
WEDNESDAY....MVFR POSSIBLE.
THURSDAY...CHANCE OF SNOW. IFR POSSIBLE.
MTF
&&
.MARINE...
420 AM CST
AN ACTIVE PATTERN MEANS MULTIPLE LOWS WILL BE MOVING ACROSS
SOUTHERN CANADA AND THE NORTHERN STATES. THIS WILL RESULT IN
REPEATED COLD FRONTAL PASSAGES ACROSS LAKE MI OVER THE NEXT
SEVERAL DAYS.
MODERATELY STRONG NW WINDS THIS MORNING WILL DIMINISH AND BACK TO
OUT OF THE SW AS A RIDGE OF HIGH PRESSURE SLIDES E TO THE UPPER
GREAT LAKES AND LOWER OH VALLEY BY THIS EVENING. WINDS WILL
INCREASE TONIGHT AS A LOW AND COLD FRONT MOVE E INTO THE WESTERN
GREAT LAKES OVERNIGHT.
ANOTHER LOW WILL DROP SE OVER NORTHERN MN BY SAT EVENING. AS IT
CONTINUES ON TO LOWER MI BY DAWN SUN...IT WILL SWEEP ANOTHER COLD
FRONT ACROSS LAKE MI. THIS LOW MOVES E TO NEAR LAKE ONTARIO BY
LATE SUN ALLOWING A RIDGE OF HIGH PRES TO SLIDE E TO THE UPPER
MIDWEST AND MID MS VALLEY SUN. IT CONTINUES MOVING ACROSS THE
UPPER GREAT LAKES TO THE LOWER LAKES AND UPPER OH VALLEY BY MON
MORNING.
YET ANOTHER LOW WILL BE MOVING ACROSS NORTHERN MN AND LAKE
SUPERIOR TUE...BRINGING ANOTHER COLD FRONT ACROSS LAKE MI.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE BURNS HARBOR TO MICHIGAN CITY IN UNTIL 3 PM FRIDAY.
GALE WATCH...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-
LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...6 AM SATURDAY TO 6 PM
SATURDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
757 AM CST FRI JAN 27 2012
.DISCUSSION...
333 AM CST
FOR TODAY...CLOUDS ON THE BACKSIDE OF THE LOW THAT IS LIFTING OUT OF
THE OHIO VALLEY...WILL CONTINUE TO CHARGE TO THE SOUTHEAST. AIRCRAFT
SOUNDINGS OUT OF ORD SHOW A FAIRLY SHALLOW SATURATED LAYER REMAINING.
UPSTREAM SOUNDINGS AND RUC ANALYSIS SHOW AN OVERALL DRYING TREND
TO CONTINUE AND NOT EXPECTING ANY EXPANSION TO THE CLOUDS EARLY
THIS MORNING. MOST LOCATIONS SHOULD SEE MOSTLY SUNNY AND BLUE
SKIES...WITH THE EXCEPTION OF THE FAR SOUTHEAST WHERE THEY WILL BE
SLUGGISH. BOTH THE RUC AND NARRE-TL GUIDANCE ARE IN AGREEMENT THAT
THE NORTHWEST SHOULD BE CLEAR BY SUNRISE...WITH THE CHICAGO METRO
A FEW HOURS BEYOND. FAST ON THE HEELS OF THE CLEAR SKIES WILL BE
MID LEVEL CLOUDS ARRIVING FROM THE WEST WITH THE NEXT WAVE MOVING
IN...AND THE ENTIRE CWA IS THEN EXPECTED TO BECOME CLOUDY AGAIN
BY THE EARLY TO MID AFTERNOON. WITH NO REAL CHANGE TO THE AIRMASS
TODAY AND TONIGHT...TEMPERATURES ARE EXPECTED TO BE CLOSE TO
CARBON COPIES OF YESTERDAY. FOCUS IN THE EVENING WILL THEN TURN
TOWARDS THE WEST AS A WEAK CLIPPER /THAT IS NOTED ON REGIONAL
RADAR THIS MORNING ACROSS THE NORTHERN DAKOTAS/ AND A WEAK
SOUTHERN STREAM SYSTEM /NEAR THE OKLAHOMA PAN HANDLE THIS MORNING/
SHIFT EAST AND NOT QUITE MERGE...RATHER COMPLICATE THE EVENING
FORECAST. THE GOOD NEWS IS THAT THE TIMING SHOULD BE AS RUSH HOUR
COMES TO A CLOSE FOR THE FAR NORTHWEST...AND HOURS BEYOND THE
CHICAGO METRO RUSH.
THE OVERALL PICTURE HAS BEEN PRETTY CONSISTENT THE LAST FEW DAYS
THAT ANYWHERE FROM AN INCH TO INCH AND A HALF OF SNOW ARE EXPECTED
WITH THIS SYSTEM. THE EARLIER 18/00Z GUIDANCE SEEMED TO BE IN DECENT
AGREEMENT WITH KEEPING THE BEST FORCING NORTH AND HAVING A BIT MORE
OF A UNIFORM TOTAL ACROSS THE AREA...WITH POTENTIALLY HIGHER AMOUNTS
NORTH OF I-80...BUT THE 00Z GFS AND ECMWF BEGAN TO THROW A WRENCH
AND GIVE THE SOUTHERN SECTION A LITTLE MORE GUSTO THAN PREVIOUS
RUNS...MAKING THE SNOW FALL A LITTLE MORE DISJOINTED. WITH DRY AIR
INVADING THE REGION THIS MORNING...IT WILL TAKE SOME TIME TO
SATURATE THE COLUMN BEFORE IT PRECIPITATES TO THE GROUND. THE OTHER
QUESTION WILL BE ON WHAT FORM THE PRECIP WILL BE AT THE ONSET.
FORECAST SOUNDINGS ARE TRYING TO HOLD ONTO SURFACE TEMPERATURES AT
OR SLIGHTLY ABOVE FREEZING THROUGH ROUGHLY 9 TO 10 PM
TONIGHT...CONTINUING TO COOL BEYOND AND INTO THE OVERNIGHT HOURS.
SIMPLE CROSS HAIRS TECHNIQUE SHOWS THE HIGHEST OMEGA VALUES
INTERSECTING THE DGZ IN A 2 OR SO HOUR WINDOW...AND GENERALLY IN THE
3-4-5Z TIME FRAME. IT IS WITHIN THIS WINDOW THAT THE BEST
ACCUMULATION SHOULD HAPPEN...BUT NOT ANTICIPATING MUCH BEYOND A HALF
INCH AN HOUR RATE WHEN THE ATMOSPHERE IS MOST EFFICIENT...AND WILL
LIKELY START AS A HEAVIER/WET SNOW. STILL CONFIDENT THAT THE
TOTALS WILL BE LOW AND IN THE GENERAL INCH TO MAYBE CLOSE TO AN
INCH AND A HALF/TWO INCH RANGE FOR SOME LOCATIONS. THE SYSTEM WILL
BE FAST MOVING AND GENERALLY TO THE EAST BY THE MORNING.
THE COOLING TREND WILL CONTINUE INTO THE WEEKEND UNDER GENERAL
NORTHWEST FLOW. THE NEXT WIGGLE IN THE FLOW WILL COME SHOOTING
ACROSS THE DAKOTAS AND BRING THE CHANCE OF SNOW TO THE ILLINOIS AND
WISCONSIN BORDER OVERNIGHT TOMORROW. MOISTURE IS LACKING WITH THIS
SYSTEM AND GENERALLY ANTICIPATING A DUSTING TO A SMIDGEN MORE FARTHER
NORTH...TYPICALLY NORTH OF THE I-88 DIVISION LINE. WITH FAIRLY FRESH
SNOW...AND ON AND OFF CLOUDS THROUGH THE WEEKEND...ONLY EXPECTING
TEMPERATURES TO DECREASE SLIGHTLY AND NOT NOSEDIVE. SUNDAY HIGHS
WILL GENERALLY RANGE FROM THE LOWER 30S TO MIDDLE 20S...WITH
OVERNIGHT LOWS 10 OR SO DEGREES BELOW THE AFTERNOON HIGHS.
THE EXTENDED FORECAST IS STILL MODERATELY LOW WITH RESPECT TO
OVERALL CONFIDENCE. ANOTHER WEAK CLIPPER WILL SLIDE ACROSS WISCONSIN
MONDAY AND BRUSH THE EXTREME NORTHERN COUNTIES. BUT THERE ARE STILL
CONSIDERABLE DIFFERENCES BETWEEN THE EC AND GFS...WITH THE GFS BEING
A LITTLE MORE BULLISH WITH THE 00Z RUN. THE BIGGEST ISSUE IN
ADJUSTING POPS UP OR DOWN IS THE FACT THAT THE GFS HAS BEEN FLOPPING
EVERY RUN WITH WHERE THE BEST AXIS LINES UP...AND THE ECMWF REMAINS
CONSISTENT AND MOVES THE NEXT SYSTEM THROUGH OUR AREA COMPLETELY
DRY. TRENDS BEYOND INDICATE A DECENT THERMAL RIDGE ALOFT BUILDING
IN FROM THE WEST...BRINGING HIGHS TUESDAY AND INTO WEDNESDAY INTO
THE MIDDLE AND UPPER 40S...TO EVEN LOWER 50S SOUTH. BY THE
EVENING...A SYSTEM WILL IMPACT THE REGION. THE DIFFERENCES AT 120
HOURS OUT ARE FROM DRY /ECMWF/ TO WET /GFS/ AND ENSEMBLE GUIDANCE
LEAVES CONFIDENCE TO GAIN. FOR NOW...WILL LEAVE ONLY CONTINUE WITH
A SLIGHTS MENTION.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* ACCUMULATING SNOW WITH TEMPORARY VISIBILITY UNDER 1SM TONIGHT.
* INCREASING GUSTY WINDS TONIGHT AFTER 03Z FROM THE WEST SOUTHWEST
BECOMING NORTHWEST INTO SATURDAY. WIND GUSTS TO 30 KTS POSSIBLE
SATURDAY.
RATZER
//DISCUSSION...UPDATED 12Z...
THE DAYTIME PERIOD IS EXPECTED TO BE QUIET AVIATION-WISE
TODAY...BUT SOME CLOUDS PRIOR TO DAYBREAK AND SOME SNOW TONIGHT
ARE THE FORECAST CHALLENGES. THE 020-030 CIGS THIS MORNING WILL
CONTINUE TO DEPART AS A BRIEF AND WEAK HIGH PRESSURE RIDGE AND
DRIER LOW-LEVEL AIR MASS SPREAD INTO THE AREA. WINDS WILL REMAIN
NORTHWEST THIS MORNING BEFORE BACKING TO THE SOUTHWEST FROM 17Z
THROUGH 22Z. AN UPPER LEVEL DISTURBANCE WILL MOVE OVER THE AREA
TONIGHT...LEADING TO SNOWFALL BY MID-EVENING AT ALL TAF SITES. IT
IS POSSIBLE THE START TIME IS SLIGHTLY EARLIER AT EACH AIRPORT
THAN PRESENTLY FORECAST. THE FORCING AND DEEPER MOISTURE FOR SNOW
IS FAIRLY PROGRESSIVE...SO THE WINDOW FOR IFR VISIBILITY AND MVFR
CIGS IN SNOW LOOKS TO BE THREE TO FIVE HOURS. THE CIGS ARE FAVORED
TO LAST SLIGHTLY AFTER THE ACCUMULATING SNOW ENDS...AND SO MIGHT
SOME FLURRIES. TOTAL ACCUMULATION AT AREA TAF SITES IS EXPECTED TO
BE BETWEEN ONE AND TWO INCHES AT THIS TIME...WITH THE SNOW
INITIALLY BEING WET AND THEN BECOMING MORE DRY AS IT WRAPS UP. IN
ADDITION...WINDS WILL BEGIN TO VEER GRADUALLY BACK TOWARDS THE
WEST AND INCREASE IN SPEED ONCE THE SNOW BEGINS THIS EVENING...AND
THEN SHARPLY TO THE NORTHWEST AND BECOME QUITE GUSTY ONCE THE
SYSTEM COLD FRONT PASSES BETWEEN 08Z AND 11Z. SOME SHALLOW BLOWING
SNOW IS LIKELY LATE TONIGHT INTO SATURDAY MORNING. WINDS ARE
FAVORED TO GUST AS HIGH AS 30 KT ON SATURDAY BETWEEN 15Z AND 22Z.
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE IN ACCUMULATING SNOW WITH AT LEAST TEMPORARY
VISIBILITY AT OR JUST UNDER ONE MILE TONIGHT. MEDIUM CONFIDENCE
IN EXACT TIMING. IT MAY NEED TO BE ADJUSTED AN HOUR EARLIER
DEPENDING ON TRENDS TODAY.
* MEDIUM CONFIDENCE IN WIND TRENDS...BUT HIGH CONFIDENCE IN GUSTS
TO 20 KTS LATE TONIGHT AND TO NEAR 30 KTS BY MID MORNING
SATURDAY.
RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...SLIGHT CHANCE OF A DUSTING SNOWFALL OVERNIGHT.
MVFR LIKELY.
SUNDAY...MORNING MVFR THEN CLEARING.
MONDAY...VFR,
TUESDAY...SLIGHT CHANCE OF RAIN...POSSIBLY MIXED WITH SNOW EARLY
AND AGAIN LATE AT NIGHT. IFR POSSIBLE.
WEDNESDAY....MVFR POSSIBLE.
THURSDAY...CHANCE OF SNOW. IFR POSSIBLE.
MTF
&&
.MARINE...
420 AM CST
AN ACTIVE PATTERN MEANS MULTIPLE LOWS WILL BE MOVING ACROSS
SOUTHERN CANADA AND THE NORTHERN STATES. THIS WILL RESULT IN
REPEATED COLD FRONTAL PASSAGES ACROSS LAKE MI OVER THE NEXT
SEVERAL DAYS.
MODERATELY STRONG NW WINDS THIS MORNING WILL DIMINISH AND BACK TO
OUT OF THE SW AS A RIDGE OF HIGH PRESSURE SLIDES E TO THE UPPER
GREAT LAKES AND LOWER OH VALLEY BY THIS EVENING. WINDS WILL
INCREASE TONIGHT AS A LOW AND COLD FRONT MOVE E INTO THE WESTERN
GREAT LAKES OVERNIGHT.
ANOTHER LOW WILL DROP SE OVER NORTHERN MN BY SAT EVENING. AS IT
CONTINUES ON TO LOWER MI BY DAWN SUN...IT WILL SWEEP ANOTHER COLD
FRONT ACROSS LAKE MI. THIS LOW MOVES E TO NEAR LAKE ONTARIO BY
LATE SUN ALLOWING A RIDGE OF HIGH PRES TO SLIDE E TO THE UPPER
MIDWEST AND MID MS VALLEY SUN. IT CONTINUES MOVING ACROSS THE
UPPER GREAT LAKES TO THE LOWER LAKES AND UPPER OH VALLEY BY MON
MORNING.
YET ANOTHER LOW WILL BE MOVING ACROSS NORTHERN MN AND LAKE
SUPERIOR TUE...BRINGING ANOTHER COLD FRONT ACROSS LAKE MI.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE BURNS HARBOR TO MICHIGAN CITY IN UNTIL 2 PM FRIDAY.
GALE WATCH...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-
LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...6 AM SATURDAY TO 6 PM
SATURDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
527 AM CST FRI JAN 27 2012
.DISCUSSION...
333 AM CST
FOR TODAY...CLOUDS ON THE BACKSIDE OF THE LOW THAT IS LIFTING OUT OF
THE OHIO VALLEY...WILL CONTINUE TO CHARGE TO THE SOUTHEAST. AIRCRAFT
SOUNDINGS OUT OF ORD SHOW A FAIRLY SHALLOW SATURATED LAYER REMAINING.
UPSTREAM SOUNDINGS AND RUC ANALYSIS SHOW AN OVERALL DRYING TREND
TO CONTINUE AND NOT EXPECTING ANY EXPANSION TO THE CLOUDS EARLY
THIS MORNING. MOST LOCATIONS SHOULD SEE MOSTLY SUNNY AND BLUE
SKIES...WITH THE EXCEPTION OF THE FAR SOUTHEAST WHERE THEY WILL BE
SLUGGISH. BOTH THE RUC AND NARRE-TL GUIDANCE ARE IN AGREEMENT THAT
THE NORTHWEST SHOULD BE CLEAR BY SUNRISE...WITH THE CHICAGO METRO
A FEW HOURS BEYOND. FAST ON THE HEELS OF THE CLEAR SKIES WILL BE
MID LEVEL CLOUDS ARRIVING FROM THE WEST WITH THE NEXT WAVE MOVING
IN...AND THE ENTIRE CWA IS THEN EXPECTED TO BECOME CLOUDY AGAIN
BY THE EARLY TO MID AFTERNOON. WITH NO REAL CHANGE TO THE AIRMASS
TODAY AND TONIGHT...TEMPERATURES ARE EXPECTED TO BE CLOSE TO
CARBON COPIES OF YESTERDAY. FOCUS IN THE EVENING WILL THEN TURN
TOWARDS THE WEST AS A WEAK CLIPPER /THAT IS NOTED ON REGIONAL
RADAR THIS MORNING ACROSS THE NORTHERN DAKOTAS/ AND A WEAK
SOUTHERN STREAM SYSTEM /NEAR THE OKLAHOMA PAN HANDLE THIS MORNING/
SHIFT EAST AND NOT QUITE MERGE...RATHER COMPLICATE THE EVENING
FORECAST. THE GOOD NEWS IS THAT THE TIMING SHOULD BE AS RUSH HOUR
COMES TO A CLOSE FOR THE FAR NORTHWEST...AND HOURS BEYOND THE
CHICAGO METRO RUSH.
THE OVERALL PICTURE HAS BEEN PRETTY CONSISTENT THE LAST FEW DAYS
THAT ANYWHERE FROM AN INCH TO INCH AND A HALF OF SNOW ARE EXPECTED
WITH THIS SYSTEM. THE EARLIER 18/00Z GUIDANCE SEEMED TO BE IN DECENT
AGREEMENT WITH KEEPING THE BEST FORCING NORTH AND HAVING A BIT MORE
OF A UNIFORM TOTAL ACROSS THE AREA...WITH POTENTIALLY HIGHER AMOUNTS
NORTH OF I-80...BUT THE 00Z GFS AND ECMWF BEGAN TO THROW A WRENCH
AND GIVE THE SOUTHERN SECTION A LITTLE MORE GUSTO THAN PREVIOUS
RUNS...MAKING THE SNOW FALL A LITTLE MORE DISJOINTED. WITH DRY AIR
INVADING THE REGION THIS MORNING...IT WILL TAKE SOME TIME TO
SATURATE THE COLUMN BEFORE IT PRECIPITATES TO THE GROUND. THE OTHER
QUESTION WILL BE ON WHAT FORM THE PRECIP WILL BE AT THE ONSET.
FORECAST SOUNDINGS ARE TRYING TO HOLD ONTO SURFACE TEMPERATURES AT
OR SLIGHTLY ABOVE FREEZING THROUGH ROUGHLY 9 TO 10 PM
TONIGHT...CONTINUING TO COOL BEYOND AND INTO THE OVERNIGHT HOURS.
SIMPLE CROSS HAIRS TECHNIQUE SHOWS THE HIGHEST OMEGA VALUES
INTERSECTING THE DGZ IN A 2 OR SO HOUR WINDOW...AND GENERALLY IN THE
3-4-5Z TIME FRAME. IT IS WITHIN THIS WINDOW THAT THE BEST
ACCUMULATION SHOULD HAPPEN...BUT NOT ANTICIPATING MUCH BEYOND A HALF
INCH AN HOUR RATE WHEN THE ATMOSPHERE IS MOST EFFICIENT...AND WILL
LIKELY START AS A HEAVIER/WET SNOW. STILL CONFIDENT THAT THE
TOTALS WILL BE LOW AND IN THE GENERAL INCH TO MAYBE CLOSE TO AN
INCH AND A HALF/TWO INCH RANGE FOR SOME LOCATIONS. THE SYSTEM WILL
BE FAST MOVING AND GENERALLY TO THE EAST BY THE MORNING.
THE COOLING TREND WILL CONTINUE INTO THE WEEKEND UNDER GENERAL
NORTHWEST FLOW. THE NEXT WIGGLE IN THE FLOW WILL COME SHOOTING
ACROSS THE DAKOTAS AND BRING THE CHANCE OF SNOW TO THE ILLINOIS AND
WISCONSIN BORDER OVERNIGHT TOMORROW. MOISTURE IS LACKING WITH THIS
SYSTEM AND GENERALLY ANTICIPATING A DUSTING TO A SMIDGEN MORE FARTHER
NORTH...TYPICALLY NORTH OF THE I-88 DIVISION LINE. WITH FAIRLY FRESH
SNOW...AND ON AND OFF CLOUDS THROUGH THE WEEKEND...ONLY EXPECTING
TEMPERATURES TO DECREASE SLIGHTLY AND NOT NOSEDIVE. SUNDAY HIGHS
WILL GENERALLY RANGE FROM THE LOWER 30S TO MIDDLE 20S...WITH
OVERNIGHT LOWS 10 OR SO DEGREES BELOW THE AFTERNOON HIGHS.
THE EXTENDED FORECAST IS STILL MODERATELY LOW WITH RESPECT TO
OVERALL CONFIDENCE. ANOTHER WEAK CLIPPER WILL SLIDE ACROSS WISCONSIN
MONDAY AND BRUSH THE EXTREME NORTHERN COUNTIES. BUT THERE ARE STILL
CONSIDERABLE DIFFERENCES BETWEEN THE EC AND GFS...WITH THE GFS BEING
A LITTLE MORE BULLISH WITH THE 00Z RUN. THE BIGGEST ISSUE IN
ADJUSTING POPS UP OR DOWN IS THE FACT THAT THE GFS HAS BEEN FLOPPING
EVERY RUN WITH WHERE THE BEST AXIS LINES UP...AND THE ECMWF REMAINS
CONSISTENT AND MOVES THE NEXT SYSTEM THROUGH OUR AREA COMPLETELY
DRY. TRENDS BEYOND INDICATE A DECENT THERMAL RIDGE ALOFT BUILDING
IN FROM THE WEST...BRINGING HIGHS TUESDAY AND INTO WEDNESDAY INTO
THE MIDDLE AND UPPER 40S...TO EVEN LOWER 50S SOUTH. BY THE
EVENING...A SYSTEM WILL IMPACT THE REGION. THE DIFFERENCES AT 120
HOURS OUT ARE FROM DRY /ECMWF/ TO WET /GFS/ AND ENSEMBLE GUIDANCE
LEAVES CONFIDENCE TO GAIN. FOR NOW...WILL LEAVE ONLY CONTINUE WITH
A SLIGHTS MENTION.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* CIGS GRADUALLY MOVING OUT FROM NORTH TO SOUTH THROUGH THE EARLY
MORNING.
* ACCUMULATING SNOW WITH TEMPORARY VISIBILITY UNDER 1SM TONIGHT.
* INCREASING GUSTY WINDS TONIGHT AFTER 03Z FROM THE WEST SOUTHWEST
BECOMING NORTHWEST INTO SATURDAY.
//DISCUSSION...UPDATED 12Z...
THE DAYTIME PERIOD IS EXPECTED TO BE QUIET AVIATION-WISE
TODAY...BUT SOME CLOUDS PRIOR TO DAYBREAK AND SOME SNOW TONIGHT
ARE THE FORECAST CHALLENGES. THE 020-030 CIGS THIS MORNING WILL
CONTINUE TO DEPART AS A BRIEF AND WEAK HIGH PRESSURE RIDGE AND
DRIER LOW-LEVEL AIR MASS SPREAD INTO THE AREA. WINDS WILL REMAIN
NORTHWEST THIS MORNING BEFORE BACKING TO THE SOUTHWEST FROM 17Z
THROUGH 22Z. AN UPPER LEVEL DISTURBANCE WILL MOVE OVER THE AREA
TONIGHT...LEADING TO SNOWFALL BY MID-EVENING AT ALL TAF SITES. IT
IS POSSIBLE THE START TIME IS SLIGHTLY EARLIER AT EACH AIRPORT
THAN PRESENTLY FORECAST. THE FORCING AND DEEPER MOISTURE FOR SNOW
IS FAIRLY PROGRESSIVE...SO THE WINDOW FOR IFR VISIBILITY AND MVFR
CIGS IN SNOW LOOKS TO BE THREE TO FIVE HOURS. THE CIGS ARE FAVORED
TO LAST SLIGHTLY AFTER THE ACCUMULATING SNOW ENDS...AND SO MIGHT
SOME FLURRIES. TOTAL ACCUMULATION AT AREA TAF SITES IS EXPECTED TO
BE BETWEEN ONE AND TWO INCHES AT THIS TIME...WITH THE SNOW
INITIALLY BEING WET AND THEN BECOMING MORE DRY AS IT WRAPS UP. IN
ADDITION...WINDS WILL BEGIN TO VEER GRADUALLY BACK TOWARDS THE
WEST AND INCREASE IN SPEED ONCE THE SNOW BEGINS THIS EVENING...AND
THEN SHARPLY TO THE NORTHWEST AND BECOME QUITE GUSTY ONCE THE
SYSTEM COLD FRONT PASSES BETWEEN 08Z AND 11Z. SOME SHALLOW BLOWING
SNOW IS LIKELY LATE TONIGHT INTO SATURDAY MORNING. WINDS ARE
FAVORED TO GUST AS HIGH AS 30 KT ON SATURDAY BETWEEN 15Z AND 22Z.
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* MEDIUM CONFIDENCE IN EXACT CLEARING TIME OF MORNING CLOUDS. HIGH
CONFIDENCE THE CLEARING IS PRIOR TO 14Z.
* HIGH CONFIDENCE IN ACCUMULATING SNOW WITH AT LEAST TEMPORARY
VISIBILITY AT OR JUST UNDER ONE MILE TONIGHT. MEDIUM CONFIDENCE
IN EXACT TIMING. IT MAY NEED TO BE ADJUSTED AN HOUR EARLIER
DEPENDING ON TRENDS TODAY.
* MEDIUM CONFIDENCE IN WIND TRENDS...BUT HIGH CONFIDENCE IN GUSTS
TO 20 KTS LATE TONIGHT AND TO NEAR 30 KTS BY MID MORNING
SATURDAY.
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...SLIGHT CHANCE OF A DUSTING SNOWFALL OVERNIGHT.
MVFR LIKELY.
SUNDAY...MORNING MVFR THEN CLEARING.
MONDAY...VFR,
TUESDAY...SLIGHT CHANCE OF RAIN...POSSIBLY MIXED WITH SNOW EARLY
AND AGAIN LATE AT NIGHT. IFR POSSIBLE.
WEDNESDAY....MVFR POSSIBLE.
THURSDAY...CHANCE OF SNOW. IFR POSSIBLE.
MTF
&&
.MARINE...
420 AM CST
AN ACTIVE PATTERN MEANS MULTIPLE LOWS WILL BE MOVING ACROSS
SOUTHERN CANADA AND THE NORTHERN STATES. THIS WILL RESULT IN
REPEATED COLD FRONTAL PASSAGES ACROSS LAKE MI OVER THE NEXT
SEVERAL DAYS.
MODERATELY STRONG NW WINDS THIS MORNING WILL DIMINISH AND BACK TO
OUT OF THE SW AS A RIDGE OF HIGH PRESSURE SLIDES E TO THE UPPER
GREAT LAKES AND LOWER OH VALLEY BY THIS EVENING. WINDS WILL
INCREASE TONIGHT AS A LOW AND COLD FRONT MOVE E INTO THE WESTERN
GREAT LAKES OVERNIGHT.
ANOTHER LOW WILL DROP SE OVER NORTHERN MN BY SAT EVENING. AS IT
CONTINUES ON TO LOWER MI BY DAWN SUN...IT WILL SWEEP ANOTHER COLD
FRONT ACROSS LAKE MI. THIS LOW MOVES E TO NEAR LAKE ONTARIO BY
LATE SUN ALLOWING A RIDGE OF HIGH PRES TO SLIDE E TO THE UPPER
MIDWEST AND MID MS VALLEY SUN. IT CONTINUES MOVING ACROSS THE
UPPER GREAT LAKES TO THE LOWER LAKES AND UPPER OH VALLEY BY MON
MORNING.
YET ANOTHER LOW WILL BE MOVING ACROSS NORTHERN MN AND LAKE
SUPERIOR TUE...BRINGING ANOTHER COLD FRONT ACROSS LAKE MI.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE BURNS HARBOR TO MICHIGAN CITY IN UNTIL 2 PM FRIDAY.
GALE WATCH...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-
LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...6 AM SATURDAY TO 6 PM
SATURDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
422 AM CST FRI JAN 27 2012
.DISCUSSION...
333 AM CST
FOR TODAY...CLOUDS ON THE BACKSIDE OF THE LOW THAT IS LIFTING OUT OF
THE OHIO VALLEY...WILL CONTINUE TO CHARGE TO THE SOUTHEAST. AIRCRAFT
SOUNDINGS OUT OF ORD SHOW A FAIRLY SHALLOW SATURATED LAYER REMAINING.
UPSTREAM SOUNDINGS AND RUC ANALYSIS SHOW AN OVERALL DRYING TREND
TO CONTINUE AND NOT EXPECTING ANY EXPANSION TO THE CLOUDS EARLY
THIS MORNING. MOST LOCATIONS SHOULD SEE MOSTLY SUNNY AND BLUE
SKIES...WITH THE EXCEPTION OF THE FAR SOUTHEAST WHERE THEY WILL BE
SLUGGISH. BOTH THE RUC AND NARRE-TL GUIDANCE ARE IN AGREEMENT THAT
THE NORTHWEST SHOULD BE CLEAR BY SUNRISE...WITH THE CHICAGO METRO
A FEW HOURS BEYOND. FAST ON THE HEELS OF THE CLEAR SKIES WILL BE
MID LEVEL CLOUDS ARRIVING FROM THE WEST WITH THE NEXT WAVE MOVING
IN...AND THE ENTIRE CWA IS THEN EXPECTED TO BECOME CLOUDY AGAIN
BY THE EARLY TO MID AFTERNOON. WITH NO REAL CHANGE TO THE AIRMASS
TODAY AND TONIGHT...TEMPERATURES ARE EXPECTED TO BE CLOSE TO
CARBON COPIES OF YESTERDAY. FOCUS IN THE EVENING WILL THEN TURN
TOWARDS THE WEST AS A WEAK CLIPPER /THAT IS NOTED ON REGIONAL
RADAR THIS MORNING ACROSS THE NORTHERN DAKOTAS/ AND A WEAK
SOUTHERN STREAM SYSTEM /NEAR THE OKLAHOMA PAN HANDLE THIS MORNING/
SHIFT EAST AND NOT QUITE MERGE...RATHER COMPLICATE THE EVENING
FORECAST. THE GOOD NEWS IS THAT THE TIMING SHOULD BE AS RUSH HOUR
COMES TO A CLOSE FOR THE FAR NORTHWEST...AND HOURS BEYOND THE
CHICAGO METRO RUSH.
THE OVERALL PICTURE HAS BEEN PRETTY CONSISTENT THE LAST FEW DAYS
THAT ANYWHERE FROM AN INCH TO INCH AND A HALF OF SNOW ARE EXPECTED
WITH THIS SYSTEM. THE EARLIER 18/00Z GUIDANCE SEEMED TO BE IN DECENT
AGREEMENT WITH KEEPING THE BEST FORCING NORTH AND HAVING A BIT MORE
OF A UNIFORM TOTAL ACROSS THE AREA...WITH POTENTIALLY HIGHER AMOUNTS
NORTH OF I-80...BUT THE 00Z GFS AND ECMWF BEGAN TO THROW A WRENCH
AND GIVE THE SOUTHERN SECTION A LITTLE MORE GUSTO THAN PREVIOUS
RUNS...MAKING THE SNOW FALL A LITTLE MORE DISJOINTED. WITH DRY AIR
INVADING THE REGION THIS MORNING...IT WILL TAKE SOME TIME TO
SATURATE THE COLUMN BEFORE IT PRECIPITATES TO THE GROUND. THE OTHER
QUESTION WILL BE ON WHAT FORM THE PRECIP WILL BE AT THE ONSET.
FORECAST SOUNDINGS ARE TRYING TO HOLD ONTO SURFACE TEMPERATURES AT
OR SLIGHTLY ABOVE FREEZING THROUGH ROUGHLY 9 TO 10 PM
TONIGHT...CONTINUING TO COOL BEYOND AND INTO THE OVERNIGHT HOURS.
SIMPLE CROSS HAIRS TECHNIQUE SHOWS THE HIGHEST OMEGA VALUES
INTERSECTING THE DGZ IN A 2 OR SO HOUR WINDOW...AND GENERALLY IN THE
3-4-5Z TIME FRAME. IT IS WITHIN THIS WINDOW THAT THE BEST
ACCUMULATION SHOULD HAPPEN...BUT NOT ANTICIPATING MUCH BEYOND A HALF
INCH AN HOUR RATE WHEN THE ATMOSPHERE IS MOST EFFICIENT...AND WILL
LIKELY START AS A HEAVIER/WET SNOW. STILL CONFIDENT THAT THE
TOTALS WILL BE LOW AND IN THE GENERAL INCH TO MAYBE CLOSE TO AN
INCH AND A HALF/TWO INCH RANGE FOR SOME LOCATIONS. THE SYSTEM WILL
BE FAST MOVING AND GENERALLY TO THE EAST BY THE MORNING.
THE COOLING TREND WILL CONTINUE INTO THE WEEKEND UNDER GENERAL
NORTHWEST FLOW. THE NEXT WIGGLE IN THE FLOW WILL COME SHOOTING
ACROSS THE DAKOTAS AND BRING THE CHANCE OF SNOW TO THE ILLINOIS AND
WISCONSIN BORDER OVERNIGHT TOMORROW. MOISTURE IS LACKING WITH THIS
SYSTEM AND GENERALLY ANTICIPATING A DUSTING TO A SMIDGEN MORE FARTHER
NORTH...TYPICALLY NORTH OF THE I-88 DIVISION LINE. WITH FAIRLY FRESH
SNOW...AND ON AND OFF CLOUDS THROUGH THE WEEKEND...ONLY EXPECTING
TEMPERATURES TO DECREASE SLIGHTLY AND NOT NOSEDIVE. SUNDAY HIGHS
WILL GENERALLY RANGE FROM THE LOWER 30S TO MIDDLE 20S...WITH
OVERNIGHT LOWS 10 OR SO DEGREES BELOW THE AFTERNOON HIGHS.
THE EXTENDED FORECAST IS STILL MODERATELY LOW WITH RESPECT TO
OVERALL CONFIDENCE. ANOTHER WEAK CLIPPER WILL SLIDE ACROSS WISCONSIN
MONDAY AND BRUSH THE EXTREME NORTHERN COUNTIES. BUT THERE ARE STILL
CONSIDERABLE DIFFERENCES BETWEEN THE EC AND GFS...WITH THE GFS BEING
A LITTLE MORE BULLISH WITH THE 00Z RUN. THE BIGGEST ISSUE IN
ADJUSTING POPS UP OR DOWN IS THE FACT THAT THE GFS HAS BEEN FLOPPING
EVERY RUN WITH WHERE THE BEST AXIS LINES UP...AND THE ECMWF REMAINS
CONSISTENT AND MOVES THE NEXT SYSTEM THROUGH OUR AREA COMPLETELY
DRY. TRENDS BEYOND INDICATE A DECENT THERMAL RIDGE ALOFT BUILDING
IN FROM THE WEST...BRINGING HIGHS TUESDAY AND INTO WEDNESDAY INTO
THE MIDDLE AND UPPER 40S...TO EVEN LOWER 50S SOUTH. BY THE
EVENING...A SYSTEM WILL IMPACT THE REGION. THE DIFFERENCES AT 120
HOURS OUT ARE FROM DRY /ECMWF/ TO WET /GFS/ AND ENSEMBLE GUIDANCE
LEAVES CONFIDENCE TO GAIN. FOR NOW...WILL LEAVE ONLY CONTINUE WITH
A SLIGHTS MENTION.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 10Z...
* LOW CEILINGS GRADUALLY DEPARTING FROM NORTHWEST TO SOUTHEAST
SOON AFTER DAYBREAK.
* VISIBILITY GRADUALLY IMPROVING.
* SNOW TONIGHT...MAINLY BETWEEN 03Z AND 08Z.
//DISCUSSION...UPDATED 06Z...
A SLOW MOVING COLD FRONT IS MOVING ACROSS THE MISSISSIPPI RIVER THIS
EVENING WITH CONDITIONS QUICKLY IMPROVING TO VFR BEHIND THE FRONT.
AHEAD OF THE FRONT...WIDESPREAD IFR/LIFR CONDITIONS PERSIST MAINLY
DUE TO LOW CIGS...WITH VARIABLE VSBY. VSBY SHOULD SHOW A GRADUAL
IMPROVING TREND OVER NEXT COUPLE HOURS AS WIND SPEEDS PICK UP
AHEAD OF THE FRONT TONIGHT...BUT CIGS WILL HOLD STEADY OR MAY FALL
SOME AS WEAK PRESSURE FALLS CONTINUE TO OVERSPREAD THE AREA. SKIES
SHOULD QUICKLY CLEAR IN THE EARLY MORNING HOURS...~06Z AT RFD AND
09-10Z FOR THE CHICAGO AREA TERMINALS...AS ANTICYCLONIC FLOW
MOVES ACROSS THE REGION BEHIND THE COLD FRONT.
MOST OF FRIDAY WILL HAVE RELATIVELY QUIET WEATHER CONDITIONS WITH
WESTERLY WINDS GRADUALLY BACKING TO THE SOUTHWEST THROUGH THE DAY AS
ANOTHER CLIPPER SYSTEM PUSHES EAST ACROSS THE NORTHERN PLAINS. THIS
SYSTEM WILL BEGIN TO AFFECT THE ROCKFORD/CHICAGO TERMINALS DURING
THE EVENING HOURS AS CIGS BEGIN TO COME DOWN AND SNOWFALL STARTING
LATE IN THE EVENING. EXPECT LIGHT ACCUMULATIONS WITH THIS SYSTEM...
AN INCH OR TWO...WITH IFR OR LOW END MVFR CONDITIONS RETURNING.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 10Z...
* HIGH CONFIDENCE THAT CIGS WILL NOW REMAIN ABOVE 1500 FT INTO
THE DAYLIGHT HOURS.
* MEDIUM CONFIDENCE IN EXACT DEPARTURE TIME OF MORNING CLOUDS...BUT
HIGH CONFIDENCE THEY WILL BE OUT OF THE AREA BY 14Z.
* MEDIUM CONFIDENCE IN VISIBILITY TRENDS THROUGH 14Z.
* MEDIUM CONFIDENCE ON SNOW TIMING TONIGHT. HIGH CONFIDENCE IN AT
LEAST TEMPORARY VISIBILITY UNDER 4SM IN SNOW.
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
SATURDAY...MVFR POSSIBLE. GUSTS TO AROUND 30KT POSSIBLE.
SUNDAY...SLIGHT CHANCE OF SNOW...ELSE VFR.
MONDAY...VFR.
TUESDAY...MVFR WITH CHANCE OF RAIN.
WEDNESDAY...MVFR.
BMD/MTF
&&
.MARINE...
420 AM CST
AN ACTIVE PATTERN MEANS MULTIPLE LOWS WILL BE MOVING ACROSS
SOUTHERN CANADA AND THE NORTHERN STATES. THIS WILL RESULT IN
REPEATED COLD FRONTAL PASSAGES ACROSS LAKE MI OVER THE NEXT
SEVERAL DAYS.
MODERATELY STRONG NW WINDS THIS MORNING WILL DIMINISH AND BACK TO
OUT OF THE SW AS A RIDGE OF HIGH PRESSURE SLIDES E TO THE UPPER
GREAT LAKES AND LOWER OH VALLEY BY THIS EVENING. WINDS WILL
INCREASE TONIGHT AS A LOW AND COLD FRONT MOVE E INTO THE WESTERN
GREAT LAKES OVERNIGHT.
ANOTHER LOW WILL DROP SE OVER NORTHERN MN BY SAT EVENING. AS IT
CONTINUES ON TO LOWER MI BY DAWN SUN...IT WILL SWEEP ANOTHER COLD
FRONT ACROSS LAKE MI. THIS LOW MOVES E TO NEAR LAKE ONTARIO BY
LATE SUN ALLOWING A RIDGE OF HIGH PRES TO SLIDE E TO THE UPPER
MIDWEST AND MID MS VALLEY SUN. IT CONTINUES MOVING ACROSS THE
UPPER GREAT LAKES TO THE LOWER LAKES AND UPPER OH VALLEY BY MON
MORNING.
YET ANOTHER LOW WILL BE MOVING ACROSS NORTHERN MN AND LAKE
SUPERIOR TUE...BRINGING ANOTHER COLD FRONT ACROSS LAKE MI.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ745...7 AM FRIDAY TO 2 PM FRIDAY.
GALE WATCH...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-
LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...6 AM SATURDAY TO 6 PM
SATURDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
420 AM CST FRI JAN 27 2012
.DISCUSSION...
333 AM CST
FOR TODAY...CLOUDS ON THE BACKSIDE OF THE LOW THAT IS LIFTING OUT OF
THE OHIO VALLEY...WILL CONTINUE TO CHARGE TO THE SOUTHEAST. AIRCRAFT
SOUNDINGS OUT OF ORD SHOW A FAIRLY SHALLOW SATURATED LAYER REMAINING.
UPSTREAM SOUNDINGS AND RUC ANALYSIS SHOW AN OVERALL DRYING TREND
TO CONTINUE AND NOT EXPECTING ANY EXPANSION TO THE CLOUDS EARLY
THIS MORNING. MOST LOCATIONS SHOULD SEE MOSTLY SUNNY AND BLUE
SKIES...WITH THE EXCEPTION OF THE FAR SOUTHEAST WHERE THEY WILL BE
SLUGGISH. BOTH THE RUC AND NARRE-TL GUIDANCE ARE IN AGREEMENT THAT
THE NORTHWEST SHOULD BE CLEAR BY SUNRISE...WITH THE CHICAGO METRO
A FEW HOURS BEYOND. FAST ON THE HEELS OF THE CLEAR SKIES WILL BE
MID LEVEL CLOUDS ARRIVING FROM THE WEST WITH THE NEXT WAVE MOVING
IN...AND THE ENTIRE CWA IS THEN EXPECTED TO BECOME CLOUDY AGAIN
BY THE EARLY TO MID AFTERNOON. WITH NO REAL CHANGE TO THE AIRMASS
TODAY AND TONIGHT...TEMPERATURES ARE EXPECTED TO BE CLOSE TO
CARBON COPIES OF YESTERDAY. FOCUS IN THE EVENING WILL THEN TURN
TOWARDS THE WEST AS A WEAK CLIPPER /THAT IS NOTED ON REGIONAL
RADAR THIS MORNING ACROSS THE NORTHERN DAKOTAS/ AND A WEAK
SOUTHERN STREAM SYSTEM /NEAR THE OKLAHOMA PAN HANDLE THIS MORNING/
SHIFT EAST AND NOT QUITE MERGE...RATHER COMPLICATE THE EVENING
FORECAST. THE GOOD NEWS IS THAT THE TIMING SHOULD BE AS RUSH HOUR
COMES TO A CLOSE FOR THE FAR NORTHWEST...AND HOURS BEYOND THE
CHICAGO METRO RUSH.
THE OVERALL PICTURE HAS BEEN PRETTY CONSISTENT THE LAST FEW DAYS
THAT ANYWHERE FROM AN INCH TO INCH AND A HALF OF SNOW ARE EXPECTED
WITH THIS SYSTEM. THE EARLIER 18/00Z GUIDANCE SEEMED TO BE IN DECENT
AGREEMENT WITH KEEPING THE BEST FORCING NORTH AND HAVING A BIT MORE
OF A UNIFORM TOTAL ACROSS THE AREA...WITH POTENTIALLY HIGHER AMOUNTS
NORTH OF I-80...BUT THE 00Z GFS AND ECMWF BEGAN TO THROW A WRENCH
AND GIVE THE SOUTHERN SECTION A LITTLE MORE GUSTO THAN PREVIOUS
RUNS...MAKING THE SNOW FALL A LITTLE MORE DISJOINTED. WITH DRY AIR
INVADING THE REGION THIS MORNING...IT WILL TAKE SOME TIME TO
SATURATE THE COLUMN BEFORE IT PRECIPITATES TO THE GROUND. THE OTHER
QUESTION WILL BE ON WHAT FORM THE PRECIP WILL BE AT THE ONSET.
FORECAST SOUNDINGS ARE TRYING TO HOLD ONTO SURFACE TEMPERATURES AT
OR SLIGHTLY ABOVE FREEZING THROUGH ROUGHLY 9 TO 10 PM
TONIGHT...CONTINUING TO COOL BEYOND AND INTO THE OVERNIGHT HOURS.
SIMPLE CROSS HAIRS TECHNIQUE SHOWS THE HIGHEST OMEGA VALUES
INTERSECTING THE DGZ IN A 2 OR SO HOUR WINDOW...AND GENERALLY IN THE
3-4-5Z TIME FRAME. IT IS WITHIN THIS WINDOW THAT THE BEST
ACCUMULATION SHOULD HAPPEN...BUT NOT ANTICIPATING MUCH BEYOND A HALF
INCH AN HOUR RATE WHEN THE ATMOSPHERE IS MOST EFFICIENT...AND WILL
LIKELY START AS A HEAVIER/WET SNOW. STILL CONFIDENT THAT THE
TOTALS WILL BE LOW AND IN THE GENERAL INCH TO MAYBE CLOSE TO AN
INCH AND A HALF/TWO INCH RANGE FOR SOME LOCATIONS. THE SYSTEM WILL
BE FAST MOVING AND GENERALLY TO THE EAST BY THE MORNING.
THE COOLING TREND WILL CONTINUE INTO THE WEEKEND UNDER GENERAL
NORTHWEST FLOW. THE NEXT WIGGLE IN THE FLOW WILL COME SHOOTING
ACROSS THE DAKOTAS AND BRING THE CHANCE OF SNOW TO THE ILLINOIS AND
WISCONSIN BORDER OVERNIGHT TOMORROW. MOISTURE IS LACKING WITH THIS
SYSTEM AND GENERALLY ANTICIPATING A DUSTING TO A SMIDGEN MORE FARTHER
NORTH...TYPICALLY NORTH OF THE I-88 DIVISION LINE. WITH FAIRLY FRESH
SNOW...AND ON AND OFF CLOUDS THROUGH THE WEEKEND...ONLY EXPECTING
TEMPERATURES TO DECREASE SLIGHTLY AND NOT NOSEDIVE. SUNDAY HIGHS
WILL GENERALLY RANGE FROM THE LOWER 30S TO MIDDLE 20S...WITH
OVERNIGHT LOWS 10 OR SO DEGREES BELOW THE AFTERNOON HIGHS.
THE EXTENDED FORECAST IS STILL MODERATELY LOW WITH RESPECT TO
OVERALL CONFIDENCE. ANOTHER WEAK CLIPPER WILL SLIDE ACROSS WISCONSIN
MONDAY AND BRUSH THE EXTREME NORTHERN COUNTIES. BUT THERE ARE STILL
CONSIDERABLE DIFFERENCES BETWEEN THE EC AND GFS...WITH THE GFS BEING
A LITTLE MORE BULLISH WITH THE 00Z RUN. THE BIGGEST ISSUE IN
ADJUSTING POPS UP OR DOWN IS THE FACT THAT THE GFS HAS BEEN FLOPPING
EVERY RUN WITH WHERE THE BEST AXIS LINES UP...AND THE ECMWF REMAINS
CONSISTENT AND MOVES THE NEXT SYSTEM THROUGH OUR AREA COMPLETELY
DRY. TRENDS BEYOND INDICATE A DECENT THERMAL RIDGE ALOFT BUILDING
IN FROM THE WEST...BRINGING HIGHS TUESDAY AND INTO WEDNESDAY INTO
THE MIDDLE AND UPPER 40S...TO EVEN LOWER 50S SOUTH. BY THE
EVENING...A SYSTEM WILL IMPACT THE REGION. THE DIFFERENCES AT 120
HOURS OUT ARE FROM DRY /ECMWF/ TO WET /GFS/ AND ENSEMBLE GUIDANCE
LEAVES CONFIDENCE TO GAIN. FOR NOW...WILL LEAVE ONLY CONTINUE WITH
A SLIGHTS MENTION.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 08Z...
* LOW CEILINGS GRADUALLY DEPARTING FROM NORTHWEST TO SOUTHEAST BY
OR SOON AFTER DAYBREAK.
* LOW VISIBILITY GRADUALLY IMPROVING.
* CHANCES FOR SNOW FRIDAY EVENING/NIGHT.
//DISCUSSION...UPDATED 06Z...
A SLOW MOVING COLD FRONT IS MOVING ACROSS THE MISSISSIPPI RIVER THIS
EVENING WITH CONDITIONS QUICKLY IMPROVING TO VFR BEHIND THE FRONT.
AHEAD OF THE FRONT...WIDESPREAD IFR/LIFR CONDITIONS PERSIST MAINLY
DUE TO LOW CIGS...WITH VARIABLE VSBY. VSBY SHOULD SHOW A GRADUAL
IMPROVING TREND OVER NEXT COUPLE HOURS AS WIND SPEEDS PICK UP
AHEAD OF THE FRONT TONIGHT...BUT CIGS WILL HOLD STEADY OR MAY FALL
SOME AS WEAK PRESSURE FALLS CONTINUE TO OVERSPREAD THE AREA. SKIES
SHOULD QUICKLY CLEAR IN THE EARLY MORNING HOURS...~06Z AT RFD AND
09-10Z FOR THE CHICAGO AREA TERMINALS...AS ANTICYCLONIC FLOW
MOVES ACROSS THE REGION BEHIND THE COLD FRONT.
MOST OF FRIDAY WILL HAVE RELATIVELY QUIET WEATHER CONDITIONS WITH
WESTERLY WINDS GRADUALLY BACKING TO THE SOUTHWEST THROUGH THE DAY AS
ANOTHER CLIPPER SYSTEM PUSHES EAST ACROSS THE NORTHERN PLAINS. THIS
SYSTEM WILL BEGIN TO AFFECT THE ROCKFORD/CHICAGO TERMINALS DURING
THE EVENING HOURS AS CIGS BEGIN TO COME DOWN AND SNOWFALL STARTING
LATE IN THE EVENING. EXPECT LIGHT ACCUMULATIONS WITH THIS SYSTEM...
AN INCH OR TWO...WITH IFR OR LOW END MVFR CONDITIONS RETURNING.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 08Z...
* MEDIUM CONFIDENCE IN EXACT DEPARTURE TIME OF MVFR CLOUDS...BUT
HIGH CONFIDENCE THEY WILL BE OUT OF THE AREA BY 13Z.
* MEDIUM CONFIDENCE IN VISIBILITY REMAINING 5SM OR HIGHER THE
REMAINDER OF THE NIGHT.
* MEDIUM CONFIDENCE ON SNOW TIMING FRIDAY NIGHT.
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
SATURDAY...MVFR POSSIBLE. GUSTS TO AROUND 30KT POSSIBLE.
SUNDAY...SLIGHT CHANCE OF SNOW...ELSE VFR.
MONDAY...VFR.
TUESDAY...MVFR WITH CHANCE OF RAIN.
WEDNESDAY...MVFR.
BMD/MTF
&&
.MARINE...
420 AM CST
AN ACTIVE PATTERN MEANS MULTIPLE LOWS WILL BE MOVING ACROSS
SOUTHERN CANADA AND THE NORTHERN STATES. THIS WILL RESULT IN
REPEATED COLD FRONTAL PASSAGES ACROSS LAKE MI OVER THE NEXT
SEVERAL DAYS.
MODERATELY STRONG NW WINDS THIS MORNING WILL DIMINISH AND BACK TO
OUT OF THE SW AS A RIDGE OF HIGH PRESSURE SLIDES E TO THE UPPER
GREAT LAKES AND LOWER OH VALLEY BY THIS EVENING. WINDS WILL
INCREASE TONIGHT AS A LOW AND COLD FRONT MOVE E INTO THE WESTERN
GREAT LAKES OVERNIGHT.
ANOTHER LOW WILL DROP SE OVER NORTHERN MN BY SAT EVENING. AS IT
CONTINUES ON TO LOWER MI BY DAWN SUN...IT WILL SWEEP ANOTHER COLD
FRONT ACROSS LAKE MI. THIS LOW MOVES E TO NEAR LAKE ONTARIO BY
LATE SUN ALLOWING A RIDGE OF HIGH PRES TO SLIDE E TO THE UPPER
MIDWEST AND MID MS VALLEY SUN. IT CONTINUES MOVING ACROSS THE
UPPER GREAT LAKES TO THE LOWER LAKES AND UPPER OH VALLEY BY MON
MORNING.
YET ANOTHER LOW WILL BE MOVING ACROSS NORTHERN MN AND LAKE
SUPERIOR TUE...BRINGING ANOTHER COLD FRONT ACROSS LAKE MI.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE BURNS HARBOR TO MICHIGAN
CITY IN TIL 2 PM FRI.
GALE WATCH...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-
LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...6 AM SAT TO 6 PM SAT.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
333 AM CST FRI JAN 27 2012
.DISCUSSION...
333 AM CST
FOR TODAY...CLOUDS ON THE BACKSIDE OF THE LOW THAT IS LIFTING OUT OF
THE OHIO VALLEY...WILL CONTINUE TO CHARGE TO THE SOUTHEAST. AIRCRAFT
SOUNDINGS OUT OF ORD SHOW A FAIRLY SHALLOW SATURATED LAYER REMAINING.
UPSTREAM SOUNDINGS AND RUC ANALYSIS SHOW AN OVERALL DRYING TREND
TO CONTINUE AND NOT EXPECTING ANY EXPANSION TO THE CLOUDS EARLY
THIS MORNING. MOST LOCATIONS SHOULD SEE MOSTLY SUNNY AND BLUE
SKIES...WITH THE EXCEPTION OF THE FAR SOUTHEAST WHERE THEY WILL BE
SLUGGISH. BOTH THE RUC AND NARRE-TL GUIDANCE ARE IN AGREEMENT THAT
THE NORTHWEST SHOULD BE CLEAR BY SUNRISE...WITH THE CHICAGO METRO
A FEW HOURS BEYOND. FAST ON THE HEELS OF THE CLEAR SKIES WILL BE
MID LEVEL CLOUDS ARRIVING FROM THE WEST WITH THE NEXT WAVE MOVING
IN...AND THE ENTIRE CWA IS THEN EXPECTED TO BECOME CLOUDY AGAIN
BY THE EARLY TO MID AFTERNOON. WITH NO REAL CHANGE TO THE AIRMASS
TODAY AND TONIGHT...TEMPERATURES ARE EXPECTED TO BE CLOSE TO
CARBON COPIES OF YESTERDAY. FOCUS IN THE EVENING WILL THEN TURN
TOWARDS THE WEST AS A WEAK CLIPPER /THAT IS NOTED ON REGIONAL
RADAR THIS MORNING ACROSS THE NORTHERN DAKOTAS/ AND A WEAK
SOUTHERN STREAM SYSTEM /NEAR THE OKLAHOMA PAN HANDLE THIS MORNING/
SHIFT EAST AND NOT QUITE MERGE...RATHER COMPLICATE THE EVENING
FORECAST. THE GOOD NEWS IS THAT THE TIMING SHOULD BE AS RUSH HOUR
COMES TO A CLOSE FOR THE FAR NORTHWEST...AND HOURS BEYOND THE
CHICAGO METRO RUSH.
THE OVERALL PICTURE HAS BEEN PRETTY CONSISTENT THE LAST FEW DAYS
THAT ANYWHERE FROM AN INCH TO INCH AND A HALF OF SNOW ARE EXPECTED
WITH THIS SYSTEM. THE EARLIER 18/00Z GUIDANCE SEEMED TO BE IN DECENT
AGREEMENT WITH KEEPING THE BEST FORCING NORTH AND HAVING A BIT MORE
OF A UNIFORM TOTAL ACROSS THE AREA...WITH POTENTIALLY HIGHER AMOUNTS
NORTH OF I-80...BUT THE 00Z GFS AND ECMWF BEGAN TO THROW A WRENCH
AND GIVE THE SOUTHERN SECTION A LITTLE MORE GUSTO THAN PREVIOUS
RUNS...MAKING THE SNOW FALL A LITTLE MORE DISJOINTED. WITH DRY AIR
INVADING THE REGION THIS MORNING...IT WILL TAKE SOME TIME TO
SATURATE THE COLUMN BEFORE IT PRECIPITATES TO THE GROUND. THE OTHER
QUESTION WILL BE ON WHAT FORM THE PRECIP WILL BE AT THE ONSET.
FORECAST SOUNDINGS ARE TRYING TO HOLD ONTO SURFACE TEMPERATURES AT
OR SLIGHTLY ABOVE FREEZING THROUGH ROUGHLY 9 TO 10 PM
TONIGHT...CONTINUING TO COOL BEYOND AND INTO THE OVERNIGHT HOURS.
SIMPLE CROSS HAIRS TECHNIQUE SHOWS THE HIGHEST OMEGA VALUES
INTERSECTING THE DGZ IN A 2 OR SO HOUR WINDOW...AND GENERALLY IN THE
3-4-5Z TIME FRAME. IT IS WITHIN THIS WINDOW THAT THE BEST
ACCUMULATION SHOULD HAPPEN...BUT NOT ANTICIPATING MUCH BEYOND A HALF
INCH AN HOUR RATE WHEN THE ATMOSPHERE IS MOST EFFICIENT...AND WILL
LIKELY START AS A HEAVIER/WET SNOW. STILL CONFIDENT THAT THE
TOTALS WILL BE LOW AND IN THE GENERAL INCH TO MAYBE CLOSE TO AN
INCH AND A HALF/TWO INCH RANGE FOR SOME LOCATIONS. THE SYSTEM WILL
BE FAST MOVING AND GENERALLY TO THE EAST BY THE MORNING.
THE COOLING TREND WILL CONTINUE INTO THE WEEKEND UNDER GENERAL
NORTHWEST FLOW. THE NEXT WIGGLE IN THE FLOW WILL COME SHOOTING
ACROSS THE DAKOTAS AND BRING THE CHANCE OF SNOW TO THE ILLINOIS AND
WISCONSIN BORDER OVERNIGHT TOMORROW. MOISTURE IS LACKING WITH THIS
SYSTEM AND GENERALLY ANTICIPATING A DUSTING TO A SMIDGEN MORE FARTHER
NORTH...TYPICALLY NORTH OF THE I-88 DIVISION LINE. WITH FAIRLY FRESH
SNOW...AND ON AND OFF CLOUDS THROUGH THE WEEKEND...ONLY EXPECTING
TEMPERATURES TO DECREASE SLIGHTLY AND NOT NOSEDIVE. SUNDAY HIGHS
WILL GENERALLY RANGE FROM THE LOWER 30S TO MIDDLE 20S...WITH
OVERNIGHT LOWS 10 OR SO DEGREES BELOW THE AFTERNOON HIGHS.
THE EXTENDED FORECAST IS STILL MODERATELY LOW WITH RESPECT TO
OVERALL CONFIDENCE. ANOTHER WEAK CLIPPER WILL SLIDE ACROSS WISCONSIN
MONDAY AND BRUSH THE EXTREME NORTHERN COUNTIES. BUT THERE ARE STILL
CONSIDERABLE DIFFERENCES BETWEEN THE EC AND GFS...WITH THE GFS BEING
A LITTLE MORE BULLISH WITH THE 00Z RUN. THE BIGGEST ISSUE IN
ADJUSTING POPS UP OR DOWN IS THE FACT THAT THE GFS HAS BEEN FLOPPING
EVERY RUN WITH WHERE THE BEST AXIS LINES UP...AND THE ECMWF REMAINS
CONSISTENT AND MOVES THE NEXT SYSTEM THROUGH OUR AREA COMPLETELY
DRY. TRENDS BEYOND INDICATE A DECENT THERMAL RIDGE ALOFT BUILDING
IN FROM THE WEST...BRINGING HIGHS TUESDAY AND INTO WEDNESDAY INTO
THE MIDDLE AND UPPER 40S...TO EVEN LOWER 50S SOUTH. BY THE
EVENING...A SYSTEM WILL IMPACT THE REGION. THE DIFFERENCES AT 120
HOURS OUT ARE FROM DRY /ECMWF/ TO WET /GFS/ AND ENSEMBLE GUIDANCE
LEAVES CONFIDENCE TO GAIN. FOR NOW...WILL LEAVE ONLY CONTINUE WITH
A SLIGHTS MENTION.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 08Z...
* LOW CEILINGS GRADUALLY DEPARTING FROM NORTHWEST TO SOUTHEAST BY
OR SOON AFTER DAYBREAK.
* LOW VISIBILITY GRADUALLY IMPROVING.
* CHANCES FOR SNOW FRIDAY EVENING/NIGHT.
//DISCUSSION...UPDATED 06Z...
A SLOW MOVING COLD FRONT IS MOVING ACROSS THE MISSISSIPPI RIVER THIS
EVENING WITH CONDITIONS QUICKLY IMPROVING TO VFR BEHIND THE FRONT.
AHEAD OF THE FRONT...WIDESPREAD IFR/LIFR CONDITIONS PERSIST MAINLY
DUE TO LOW CIGS...WITH VARIABLE VSBY. VSBY SHOULD SHOW A GRADUAL
IMPROVING TREND OVER NEXT COUPLE HOURS AS WIND SPEEDS PICK UP
AHEAD OF THE FRONT TONIGHT...BUT CIGS WILL HOLD STEADY OR MAY FALL
SOME AS WEAK PRESSURE FALLS CONTINUE TO OVERSPREAD THE AREA. SKIES
SHOULD QUICKLY CLEAR IN THE EARLY MORNING HOURS...~06Z AT RFD AND
09-10Z FOR THE CHICAGO AREA TERMINALS...AS ANTICYCLONIC FLOW
MOVES ACROSS THE REGION BEHIND THE COLD FRONT.
MOST OF FRIDAY WILL HAVE RELATIVELY QUIET WEATHER CONDITIONS WITH
WESTERLY WINDS GRADUALLY BACKING TO THE SOUTHWEST THROUGH THE DAY AS
ANOTHER CLIPPER SYSTEM PUSHES EAST ACROSS THE NORTHERN PLAINS. THIS
SYSTEM WILL BEGIN TO AFFECT THE ROCKFORD/CHICAGO TERMINALS DURING
THE EVENING HOURS AS CIGS BEGIN TO COME DOWN AND SNOWFALL STARTING
LATE IN THE EVENING. EXPECT LIGHT ACCUMULATIONS WITH THIS SYSTEM...
AN INCH OR TWO...WITH IFR OR LOW END MVFR CONDITIONS RETURNING.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 08Z...
* MEDIUM CONFIDENCE IN EXACT DEPARTURE TIME OF MVFR CLOUDS...BUT
HIGH CONFIDENCE THEY WILL BE OUT OF THE AREA BY 13Z.
* MEDIUM CONFIDENCE IN VISIBILITY REMAINING 5SM OR HIGHER THE
REMAINDER OF THE NIGHT.
* MEDIUM CONFIDENCE ON SNOW TIMING FRIDAY NIGHT.
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
SATURDAY...MVFR POSSIBLE. GUSTS TO AROUND 30KT POSSIBLE.
SUNDAY...SLIGHT CHANCE OF SNOW...ELSE VFR.
MONDAY...VFR.
TUESDAY...MVFR WITH CHANCE OF RAIN.
WEDNESDAY...MVFR.
BMD/MTF
&&
.MARINE...
245 PM CST
RATHER BENIGN WEATHER FOR THIS AFTERNOON ACROSS LAKE
MICHIGAN...WITH MINIMAL WIND. ACROSS THE FAR NORTHERN TIER OF LAKE
MICHIGAN THE PRESSURE GRADIENT WAS SLIGHTLY STRONGER...RESULTING
IN WINDS BETWEEN 10 TO 20 KT. FURTHER SOUTH OVER THE SOUTHERN
THIRD OF THE LAKE...WINDS HAVE REMAINED LGT AND VRB LESS THAN
10KT. BASED ON LATEST HI-RES GUIDANCE...IT APPEARS WINDS WILL
CONTINUE TO BE LGT AND VRB THRU MIDNIGHT. MEANWHILE TWO LOW
PRESSURE SYSTEMS WILL BEGIN TO INFLUENCE THE WEATHER FOR LAKE
MICHIGAN. ONE SYSTEM CURRENTLY OVER SOUTHERN MANITOBA...WILL
DEEPEN AND LIFT NORTHEAST TOWARDS HUDSON BAY FRIDAY EVENING/EARLY
SATURDAY. WHILE A SOUTHERN STREAM LOW PRESSURE SYSTEM WILL DEVELOP
OVER THE TENNESSEE VALLEY...AND IS EXPECTED TO STRENGTHEN AND
LIFT NORTHEAST TOWARDS THE EASTERN GREAT LAKES REGION SATURDAY. THE
LOW PRESSURE OVER HUDSON BAY WILL HAVE A TRAILING FRONTAL BOUNDARY
THAT WILL PUSH EAST ACROSS LAKE MICHIGAN SATURDAY...WITH AN
INCREASING PRESSURE GRADIENT BEHIND IT. LATEST GUIDANCE HAS
CONTINUED TO TREND UPWARD THAT BY SATURDAY MIDDAY/AFTERNOON
OCCASIONAL GALE FORCE GUSTS WILL BE POSSIBLE TO 35KT. AT THIS TIME
HAVE OPTED TO REFRAIN FROM HOISTING ANY HEADLINES...AS CURRENTLY
ONLY COMING UP WITH MARGINAL CRITERIA.
A LULL IN THE WEATHER WILL OCCUR FOR LATE SAT EVE/EARLY SUN...BEFORE
YET ANOTHER LOW PRESSURE IS PROGGED TO DEVELOP OVER THE DAKOTAS AND
APPROACH THE WESTERN GREAT LAKES MIDDAY SUN. THEN HIGH PRESSURE WILL
RELAX THE GRADIENT FOR SUN NGT INTO EARLY MON...BEFORE THE ACTIVE
PATTERN CONTINUES EARLY NEXT WEEK.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ745...7 AM FRIDAY TO 2 PM FRIDAY.
GALE WATCH...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-
LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...6 AM SATURDAY TO 6 PM
SATURDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
100 PM EST FRI JAN 27 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
A SERIES OF FRONTS WILL MOVE ACROSS CENTRAL INDIANA DURING THE
UPCOMING WEEK...BRINGING PERIODIC CHANCES FOR PRECIPITATION.
TEMPERATURES WILL START OFF NEAR OR BELOW AVERAGE...BUT WARM TO
ABOVE AVERAGE READINGS BY EARLY NEXT WEEK.
&&
.NEAR TERM /THIS AFTERNOON/...
STRATOCU REMAINS STUBBORN AND ONLY GIVING WAY SLOWLY LATE THIS
MORNING...AS BACK EDGE MOVING INTO THE WABASH VALLEY AT THIS TIME.
TEMPS HAVE BEEN HELD IN THE LOWER AND MID 30S ALL MORNING
UNDERNEATH THE THICK STRATOCU DECK.
MAIN CHANGES FOR THIS AFTERNOON FOCUS ON THE LOW CLOUDS AND
SUBSEQUENT IMPACTS TO TEMPS. MOST RECENT RUC DATA SUGGESTIVE THAT
BACK EDGE OF THE CLOUDS WILL LIKELY TAKE A LARGE PART OF THE
AFTERNOON TO MOVE OUT OF MUCH OF THE AREA...AND MAY NOT COMPLETELY
DEPART THE EASTERN COUNTIES BEFORE THE HIGHER CLOUDS AHEAD OF THE
CLIPPER FOR TONIGHT BEGIN ARRIVING FROM THE WEST. HAVE THEREFORE
BEEFED UP CLOUD COVER FOR THE AFTERNOON HOURS AND BUMPED DOWN
TEMPS A DEGREE OR TWO. STILL OPTIMISTIC THAT THE BACK EDGE OF THE
CLOUDS WILL MAKE IT TO THE INDY METRO BY MID AFTERNOON WITH A VERY
BRIEF PERIOD OF FILTERED SUNSHINE AS THE HIGHER CLOUDS MOVE IN
FROM THE WEST.
ZONE AND GRID UPDATES OUT SHORTLY.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
FOCUS IS ON CHANCES FOR SNOW THROUGH THE PERIOD. MODELS ARE
SIMILAR ENOUGH THAT A BLEND CAN BE USED FOR MOST FEATURES.
ISENTROPIC LIFT RAMPS UP LATER THIS EVENING AND OVERNIGHT AHEAD OF
AN APPROACHING FRONT. THIS LIFT PLUS AVAILABLE MOISTURE WILL LEAD
TO PRECIPITATION ACROSS MUCH OF THE AREA. THUS WENT ABOVE MOS POPS
AND CONTINUED LIKELY POPS ACROSS THE NORTHERN 2/3 OF THE FORECAST
AREA WITH CHANCE POPS SOUTH.
BASED ON MODEL SOUNDINGS IT LOOKS LIKE THE SOUTHERN FORECAST AREA
COULD SEE A MIX OF RAIN AND SNOW UNTIL LATER TONIGHT WHEN ALL SNOW
CAN BE EXPECTED. ACROSS THE NORTH...SNOW LOOKS TO BE THE
PRECIPITATION TYPE. BASED ON EXPECTED QPF HAVE LOWERED SNOW
AMOUNTS A BIT...WITH AROUND 1 INCH EXPECTED NORTH TO 1/2 TO 1 INCH
CENTRAL TO A FEW TENTHS SOUTH DUE TO MIXING WITH RAIN.
WITH CLOUDS AND PRECIPITATION AROUND...STUCK CLOSER TO THE WARMER
MAV NUMBERS FOR LOWS TONIGHT.
COLDER AIR WILL MOVE INTO THE AREA ON SATURDAY. A DECENT PRESSURE
GRADIENT WILL LEAD TO WINDY CONDITIONS WITH GUSTS NEAR 30KT
POSSIBLE. THE WINDS SHOULD BRING IN ENOUGH DRY AIR FOR PARTLY
CLOUDY SKIES. A MOS BLEND LOOKS GOOD FOR TEMPERATURES GIVEN
EXPECTED CONDITIONS.
YET ANOTHER FRONT WILL APPROACH AND MOVE INTO THE AREA SATURDAY
NIGHT AND SUNDAY WITH A BRIEF SHOT OF COLD AIR BEHIND IT. THERE
WILL BE SOME DECENT LIFT AS SHOWN BY Q-VECTOR CONVERGENCE...BUT
THERE MAY NOT BE AS MUCH MOISTURE WITH THIS SYSTEM AS THE ONE
BEFORE IT. THUS WILL ONLY GO LOW POPS ON SUNDAY. THERMAL PROFILES
SHOW SNOW AS THE PRECIPITATION TYPE. THERE WILL BE GUSTY WINDS
AGAIN ON SUNDAY WITH A CONTINUED TIGHT PRESSURE GRADIENT AROUND.
DRIER AIR WILL QUICKLY MOVE IN FOR SUNDAY NIGHT PROVIDING DRY
CONDITIONS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
LONG RANGE MODELS HAVING SOME TIMING DIFFERENCES WITH SYNOPTIC
DETAILS AS WELL AS QPF...SO DID NOT FEEL COMFORTABLE CHANGING THE
CENTRAL REGION EXTENDED. ONE FRONTAL SYSTEM IS EXPECTED TO BRING A
CHANCE OF RAIN IN BY TUESDAY AND LINGER INTO OUR SOUTHEAST ON
WEDNESDAY MORNING. THEN...ANOTHER SYSTEM WILL BRING RAIN CHANCES
INTO THE SOUTHWEST WEDNESDAY NIGHT AND ACROSS ALL OF CENTRAL INDIANA
THURSDAY. COULD SEE A MIX OF RAIN AND SNOW OVERNIGHT WEDNESDAY
NIGHT...OTHERWISE...MILD TREND TO CONTINUE AS HAS BEEN THE CASE MOST
OF THE WINTER WITH QUASI-ZONAL FLOW ALOFT KEEPING THE COLDER
CANADIAN AIR NORTH OF THE OHIO VALLEY. DAYTIME HIGHS IN THE 40S
ANTICIPATED WITH 50S ACROSS PARTS OF SOUTH CENTRAL INDIANA TUESDAY
THROUGH WEDNESDAY.
&&
.AVIATION /DISCUSSION FOR THE 27/18Z TAF ISSUANCE/...
CLEARING LINE OF PERSISTENT CLOUD DECK IS ENTERING KLAF AND WILL
MOVE ACROSS REMAINING TAF SITES OVER THE NEXT FEW HOURS.
ANTICIPATE RETURN TO VFR CONDITIONS AT ALL TAF SITES BY MID
AFTERNOON. HOWEVER...HIGH CLOUDS WILL QUICKLY BUILD INTO THE AREA
AS A QUICK CLIPPER SYSTEM MOVES CLOSER. THIS SYSTEM WILL PRODUCE
SNOW AT KIND AND KLAF...AND MAINLY A RAIN/SNOW MIX AT KHUF AND
KBMG AFTER SAT 06Z CAUSING MVFR/IFR CONDITIONS. THIS
DISTURBANCE WILL EXIT QUICKLY THOUGH...AND PRECIP WILL COME TO
AN END BY DAYBREAK TOMORROW. MVFR CONDITIONS WILL LINGER UNTIL MID
MORNING TOMORROW...AND THEN BACK TO VFR BY LATE MORNING AS CLOUDS
SCATTER OUT.
WEST WINDS WILL INCREASE AROUND DAYBREAK TOMORROW AND WILL BECOME
STRONGER THROUGH THE COURSE OF THE DAY. SUSTAINED SPEEDS WILL
RANGE FROM 15 TO 20 KTS WITH GUSTS UP TO 30 KTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...RYAN
SHORT TERM...50
LONG TERM....MK
AVIATION...TDUD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1114 AM EST FRI JAN 27 2012
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A SERIES OF FRONTS WILL MOVE ACROSS CENTRAL INDIANA DURING THE
UPCOMING WEEK...BRINGING PERIODIC CHANCES FOR PRECIPITATION.
TEMPERATURES WILL START OFF NEAR OR BELOW AVERAGE...BUT WARM TO
ABOVE AVERAGE READINGS BY EARLY NEXT WEEK.
&&
.NEAR TERM /THIS AFTERNOON/...
STRATOCU REMAINS STUBBORN AND ONLY GIVING WAY SLOWLY LATE THIS
MORNING...AS BACK EDGE MOVING INTO THE WABASH VALLEY AT THIS TIME.
TEMPS HAVE BEEN HELD IN THE LOWER AND MID 30S ALL MORNING
UNDERNEATH THE THICK STRATOCU DECK.
MAIN CHANGES FOR THIS AFTERNOON FOCUS ON THE LOW CLOUDS AND
SUBSEQUENT IMPACTS TO TEMPS. MOST RECENT RUC DATA SUGGESTIVE THAT
BACK EDGE OF THE CLOUDS WILL LIKELY TAKE A LARGE PART OF THE
AFTERNOON TO MOVE OUT OF MUCH OF THE AREA...AND MAY NOT COMPLETELY
DEPART THE EASTERN COUNTIES BEFORE THE HIGHER CLOUDS AHEAD OF THE
CLIPPER FOR TONIGHT BEGIN ARRIVING FROM THE WEST. HAVE THEREFORE
BEEFED UP CLOUD COVER FOR THE AFTERNOON HOURS AND BUMPED DOWN
TEMPS A DEGREE OR TWO. STILL OPTIMISTIC THAT THE BACK EDGE OF THE
CLOUDS WILL MAKE IT TO THE INDY METRO BY MID AFTERNOON WITH A VERY
BRIEF PERIOD OF FILTERED SUNSHINE AS THE HIGHER CLOUDS MOVE IN
FROM THE WEST.
ZONE AND GRID UPDATES OUT SHORTLY.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
FOCUS IS ON CHANCES FOR SNOW THROUGH THE PERIOD. MODELS ARE
SIMILAR ENOUGH THAT A BLEND CAN BE USED FOR MOST FEATURES.
ISENTROPIC LIFT RAMPS UP LATER THIS EVENING AND OVERNIGHT AHEAD OF
AN APPROACHING FRONT. THIS LIFT PLUS AVAILABLE MOISTURE WILL LEAD
TO PRECIPITATION ACROSS MUCH OF THE AREA. THUS WENT ABOVE MOS POPS
AND CONTINUED LIKELY POPS ACROSS THE NORTHERN 2/3 OF THE FORECAST
AREA WITH CHANCE POPS SOUTH.
BASED ON MODEL SOUNDINGS IT LOOKS LIKE THE SOUTHERN FORECAST AREA
COULD SEE A MIX OF RAIN AND SNOW UNTIL LATER TONIGHT WHEN ALL SNOW
CAN BE EXPECTED. ACROSS THE NORTH...SNOW LOOKS TO BE THE
PRECIPITATION TYPE. BASED ON EXPECTED QPF HAVE LOWERED SNOW
AMOUNTS A BIT...WITH AROUND 1 INCH EXPECTED NORTH TO 1/2 TO 1 INCH
CENTRAL TO A FEW TENTHS SOUTH DUE TO MIXING WITH RAIN.
WITH CLOUDS AND PRECIPITATION AROUND...STUCK CLOSER TO THE WARMER
MAV NUMBERS FOR LOWS TONIGHT.
COLDER AIR WILL MOVE INTO THE AREA ON SATURDAY. A DECENT PRESSURE
GRADIENT WILL LEAD TO WINDY CONDITIONS WITH GUSTS NEAR 30KT
POSSIBLE. THE WINDS SHOULD BRING IN ENOUGH DRY AIR FOR PARTLY
CLOUDY SKIES. A MOS BLEND LOOKS GOOD FOR TEMPERATURES GIVEN
EXPECTED CONDITIONS.
YET ANOTHER FRONT WILL APPROACH AND MOVE INTO THE AREA SATURDAY
NIGHT AND SUNDAY WITH A BRIEF SHOT OF COLD AIR BEHIND IT. THERE
WILL BE SOME DECENT LIFT AS SHOWN BY Q-VECTOR CONVERGENCE...BUT
THERE MAY NOT BE AS MUCH MOISTURE WITH THIS SYSTEM AS THE ONE
BEFORE IT. THUS WILL ONLY GO LOW POPS ON SUNDAY. THERMAL PROFILES
SHOW SNOW AS THE PRECIPITATION TYPE. THERE WILL BE GUSTY WINDS
AGAIN ON SUNDAY WITH A CONTINUED TIGHT PRESSURE GRADIENT AROUND.
DRIER AIR WILL QUICKLY MOVE IN FOR SUNDAY NIGHT PROVIDING DRY
CONDITIONS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
LONG RANGE MODELS HAVING SOME TIMING DIFFERENCES WITH SYNOPTIC
DETAILS AS WELL AS QPF...SO DID NOT FEEL COMFORTABLE CHANGING THE
CENTRAL REGION EXTENDED. ONE FRONTAL SYSTEM IS EXPECTED TO BRING A
CHANCE OF RAIN IN BY TUESDAY AND LINGER INTO OUR SOUTHEAST ON
WEDNESDAY MORNING. THEN...ANOTHER SYSTEM WILL BRING RAIN CHANCES
INTO THE SOUTHWEST WEDNESDAY NIGHT AND ACROSS ALL OF CENTRAL INDIANA
THURSDAY. COULD SEE A MIX OF RAIN AND SNOW OVERNIGHT WEDNESDAY
NIGHT...OTHERWISE...MILD TREND TO CONTINUE AS HAS BEEN THE CASE MOST
OF THE WINTER WITH QUASI-ZONAL FLOW ALOFT KEEPING THE COLDER
CANADIAN AIR NORTH OF THE OHIO VALLEY. DAYTIME HIGHS IN THE 40S
ANTICIPATED WITH 50S ACROSS PARTS OF SOUTH CENTRAL INDIANA TUESDAY
THROUGH WEDNESDAY.
&&
.AVIATION /DISCUSSION FOR THE 27/15Z TAF UPDATE/...
UPDATE...
CONDITIONS HAVE BEEN SLOW TO IMPROVE. IFR CATEGORY CONDITIONS
CONTINUE TO LINGER AT KIND AND WILL MOST LIKELY DO SO THROUGH
LATE MORNING. ORIGINAL THINKING WAS THAT VFR CONDITIONS WOULD
RETURN BY EARLY AFTERNOON...BUT THAT MAY HAVE BEEN TOO OPTIMISTIC.
ANTICIPATE MVFR CONDITIONS FOR THE FIRST PART OF THE
AFTERNOON...AND THEN VFR LATER TODAY.
PREVIOUS DISCUSSION...
CONDITIONS HAVE IMPROVED TO MVFR AND SHOULD REMAIN SO THIS MORNING.
SHOULD SEE ONLY SCATTERED VFR CU AND A BROKEN AC DECK AFTER 16Z AT
LAF AND HUF AND 18Z AT IND AND BMG AS THE CLEARING LINE ACROSS
EASTERN ILLINOIS PROGRESSES EASTWARD. A COLD FRONT WILL THEN BRING
SOME LIGHT SNOW TO IND AND LAF AND RAIN OR SNOW TO HUF AND BMG AFTER
04Z BRINGING MVFR CEILINGS OR WORSE IN. FINALLY...WINDS WILL SHIFT
FROM NORTHWEST AROUND 10 KNOTS TODAY TO SOUTHWEST LESS THAN 10 KNOTS
TONIGHT AND INCREASE TO WEST AT 15 KNOTS AND GUSTING TO 22 KNOTS AT
FROPA WHICH SHOULD BE AROUND 10Z AT LAF AND HUF TO 12Z AT IND AND
BMG. THE PRECIPITATION SHOULD ALSO END AT FROPA.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...RYAN
SHORT TERM...50
LONG TERM....MK
AVIATION...MK/TDUD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
208 PM EST THU JAN 26 2012
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
PRECIPITATION WILL COME TO AN END TONIGHT AS LOW PRESSURE AND A
FRONTAL BOUNDARY MOVE EAST AWAY FROM THE OHIO VALLEY. AFTER A DRY
DAY FRIDAY...A QUICK MOVING ALBERTA CLIPPER WILL TRACK THROUGH THE
LOWER GREAT LAKES FRIDAY NIGHT WITH THE CHANCE FOR LIGHT SNOW FOR
CENTRAL INDIANA. AN ADDITIONAL CLIPPER MAY BRING FLURRIES OR LIGHT
SNOW AGAIN FOR SUNDAY MORNING. DRY WEATHER RETURNS TO END THE
WEEKEND AS HIGH PRESSURE SPREADS ACROSS THE AREA. TEMPERATURES WILL
WARM FOR EARLY NEXT WEEK WITH THE NEXT CHANCE FOR RAIN COMING
TUESDAY AND WEDNESDAY AS A FRONT MOVES THROUGH THE OHIO VALLEY.
&&
.NEAR TERM /REST OF TONIGHT/...
MAIN ADJUSTMENTS OVERNIGHT WILL BE TO SLOW DOWN ENDING OF
PRECIPITATION A LITTLE...DOWN PLAY SNOW AND ADD PATCHY FOG TO MOST
AREAS BASED ON CURRENT CONDITIONS UPSTREAM. RADAR AT 0230Z STILL
SHOWS AN EXTENSIVE AREA OF LIGHT RAIN SHOWERS ACROSS MOST OF OUR
FORECAST AREA AND RUC STILL SHOWS ACCUMULATIONS OVER MOST OF OUR
AREA THROUGH 09Z AND ACROSS THE EAST HALF THROUGH 12Z.
SO FAR NO AREAS OF SNOW HAVE DEVELOPED YET UPSTREAM AND RUC AND 18Z
GFS HAVE BACKED OFF CONSIDERABLY ON SNOWFALL LATE TONIGHT. 1000-850
MB THICKNESSES DROP BELOW 1300 METERS ALL BUT FAR SOUTHEAST BY 12Z.
BUT MOST OF THIS HAPPENS BETWEEN 09Z-12Z. WITH TEMPERATURES AND LOW
LEVEL THICKNESS MORE IFFY WILL MENTION A MIXTURE ALL BUT FAR SOUTH
AND SOUTHEAST LATE TONIGHT.
THERE HAVE BEEN AREAS OF FOG ACROSS CENTRAL ILLINOIS AND WILL ADD
MENTION OF PATCHY FOG MOST AREAS LATER TONIGHT. BUT WITH WINDS
INCREASING OVERNIGHT...I DO NOT EXPECT FOG TO BE A SIGNIFICANT
CONCERN.
AS FAR AS TEMPERATURES ARE CONCERNED...WILL RAISE LOWS A LITTLE MOST
AREAS OVERNIGHT DUE TO CLOUDS AND MILD TEMPERATURES UPSTREAM.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
SLOWED DOWN CLEARING A LITTLE ON FRIDAY AS SATELLITE SHOWS CLOUDS
EXTENDING BACK INTO EASTERN IOWA. OTHERWISE NO OTHER CHANGES MADE TO
GRIDS AFTER TONIGHT. PREVIOUS SHORT TERM DISCUSSION FOLLOWS...
FORECAST CHALLENGES FOCUS ON POTENTIAL FOR ANOTHER QUICK SHOT OF
LIGHT SNOW FRIDAY NIGHT/EARLY SATURDAY AS A CLIPPER SYSTEM SWINGS
THROUGH THE LOWER GREAT LAKES.
FIRST CHALLENGE FOR FRIDAY FOCUSES ON THE CLOUD COVER WHICH APPEARS
INCREASINGLY LIKELY TO LINGER WELL INTO THE MORNING...ESPECIALLY
OVER THE EASTERN HALF OF THE FORECAST AREA. MODEL SOUNDINGS SHOWING
A LEFTOVER INVERSION PRESENT WITH MOISTURE TRAPPED BENEATH IT. HAVE
THEREFORE BUMPED UP CLOUD COVER THROUGH MIDDAY...WITH DIMINISHING
LOW CLOUDS THEREAFTER AS THE INVERSION RELAXES. SUNSHINE THOUGH MAY
BE BRIEF AS MID AND HIGH LEVEL CLOUDS AHEAD OF THE APPROACHING
CLIPPER WILL ALREADY BE SPREADING INTO THE REGION FROM THE WEST BY
THE AFTERNOON THICKENING UP BY EARLY EVENING.
MODEL GUIDANCE HAS COME IN WITH A SHARPER CLIPPER SYSTEM FOR FRIDAY
NIGHT AND ALTHOUGH THE BULK OF THE DEEPER FORCING WILL REMAIN
CONFINED TO THE NORTH OF THE REGION CLOSER TO THE TRACK OF THE
LOW...SYSTEM WILL HAVE A GREATER IMPACT ON CENTRAL INDIANA AND
PARTICULARLY OVER THE NORTHERN HALF OF THE FORECAST AREA LATE FRIDAY
NIGHT. SYSTEM APPEARS TO BE A BIT STRONGER THAN PREVIOUS RUNS
INDICATED AND THERE IS MORE AMPLE MOISTURE AVAILABLE AS MID LEVEL
ENERGY DIVES OUT OF THE NORTHERN PLAINS AND HELPS AMPLIFY THE
SHORTWAVE ALOFT. DIV Q VALUES ALSO APPEAR QUITE FAVORABLE FOR A
SEVERAL HOUR PERIOD OF LIGHT TO OCCASIONALLY MODERATE SNOWFALL TO
ENCOMPASS THE NORTHERN HALF OF THE FORECAST AREA AS THE CLIPPER
PASSES THROUGH THE LOWER GREAT LAKES.
OTHER THAN A FEW FLURRIES...ANTICIPATE MUCH OF THE FORECAST AREA
REMAINS DRY UNTIL LATE EVENING AS LOWER LEVELS MOISTEN UP AND
SATURATE. AREA OF SNOW WILL THEN PROGRESS ACROSS THE FORECAST AREA
FOR THE REST OF THE NIGHT THROUGH A BOUT 12Z SATURDAY. TEMPS WILL
REMAIN NEAR IF NOT JUST ABOVE FREEZING FRIDAY EVENING AND INTO THE
OVERNIGHT BEFORE FALLING BACK INTO THE UPPER 20S/LOWER 30S WITH THE
ONSET OF SNOWFALL. GROWING CONFIDENCE IN LIGHT ACCUMULATIONS FOR
LOCATIONS NORTH OF A TERRE HAUTE-BLOOMINGTON-RUSHVILLE LINE RANGING
FROM A FEW TENTHS NEAR THOSE CITIES TO AROUND AN INCH ALONG THE I-70
CORRIDOR AND INCLUDING THE INDY METRO. OVER NORTHERN FORECAST AREA
WHERE FORCING ALOFT IS MORE ABUNDANT...FEEL 1.5 TO 2 INCHES MAY BE
ACHIEVABLE BY SATURDAY MORNING. OVER FAR SOUTHERN COUNTIES...LOWER
CONFIDENCE IN ANY SNOW ACCUMULATIONS AS BOUNDARY LAYER CONDITIONS
WILL BE MARGINAL TO SUPPORT AT BEST AND MAY SEE RA/SN MIX FOR THE
DURATION OF THE EVENT. WILL BE ISSUING AN SPS TO FURTHER HIGHLIGHT
SNOW POTENTIAL WITH THIS SYSTEM.
MUCH DRIER AIR AND A SHOT OF SUBSIDENCE ALOFT WILL SERVE TO DRY OUT
THE REGION QUICKLY SATURDAY MORNING...SETTING THE STAGE FOR A BREEZY
CHILLY DAY. STRONG HIGH PRESSURE WILL DRIFT BY TO THE SOUTH OF THE
REGION THROUGH THE COURSE OF THE DAY AND EVENING...WITH CLOUDS ONCE
AGAIN INCREASING LATE SATURDAY NIGHT AS ANOTHER CLIPPER MOVES INTO
THE WESTERN GREAT LAKES. WITH MODEL SOUNDINGS INDICATING AN
ABUNDANCE OF DRY AIR IN THE LOWER LEVELS SATURDAY NIGHT...ONLY
ANTICIPATING A FEW FLURRIES NORTH OF I-70 AT THIS TIME PRIOR TO
DAYBREAK SUNDAY.
TEMPS...WITH THE ANTICIPATED LATER DEPARTURE OF THE LOW CLOUDS
FRIDAY...LOWERED HIGHS BY A FEW DEGREES FROM PREVIOUS FORECAST. WENT
ABOVE GUIDANCE FOR LOWS FRIDAY NIGHT...THEN UNDERCUT BY SEVERAL
DEGREES SATURDAY AS COLD ADVECTION WILL KEEP TEMPS FROM RISING
MORE THAN 5 TO 8 DEGREES FROM MORNING LOWS. NEAR GUIDANCE ON LOWS
SATURDAY NIGHT FALLING INTO THE LOWER AND MID 20S.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
LONG RANGE MODELS HAVING SOME TIMING DIFFERENCES WITH SYNOPTIC
DETAILS AS WELL AS QPF...SO DID NOT FEEL COMFORTABLE CHANGING THE
CENTRAL REGION EXPENTED. ONE FRONTAL SYSTEM IS EXPECTED TO BRING A
CHANCE OF RAIN IN BY TUESDAY AND LINGER INTO OUR SOUTHEAST ON
WEDNESDAY MORNING. THEN...ANOTHER SYSTEM WILL BRING RAIN CHANCES
INTO THE SOUTHWEST WEDNESDAY NIGHT AND ACROSS ALL OF CENTRAL INDIANA
THURSDAY. COULD SEE A MIX OF RAIN AND SNOW OVERNIGHT WEDNESDAY
NIGHT...OTHERWISE...MILD TREND TO CONTINUE AS HAS BEEN THE CASE MOST
OF THE WINTER WITH QUASI-ZONAL FLOW ALOFT KEEPING THE COLDER
CANADIAN AIR NORTH OF THE OHIO VALLEY. DAYTIME HIGHS IN THE 40S
ANTICIPATED WITH 50S ACROSS PARTS OF SOUTH CENTRAL INDIANA TUESDAY
THROUGH WEDNESDAY.
&&
.AVIATION /DISCUSSION FOR 270600Z KIND TAF ISSUANCE/...
IFR CEILINGS AT THE SITES WITH SOME RAIN STILL LINGERING OVER KBMG
AND KIND THAT WILL MOVE OUT BY 8Z IF NOT BEFORE. AT KHUF AND KLAF
PRECIPITATION SHOULD BE EAST OF THE SITES BY ISSUANCE TIME WITH THE
POSSIBLE EXCEPTION OF SOME DRIZZLE AT KHUF. WHILE GUIDANCE DOESN/T
INDICATE THIS...UPSTREAM OBS SHOW THAT VISIBILITIES COULD DROP ONCE
THE PRECIPITATION MOVES OUT. WILL PROBABLY KEEP THEM AT IFR LEVELS
UNTIL DAYBREAK. CEILINGS WILL STAY IFR OR DROP TO LIFR THROUGH THE
NIGHT. SHORTLY AFTER DAYBREAK THEY SHOULD RAISE TO MVFR AND THEN VFR
AT KLAF AND KHUF. KBMG AND KIND WILL LINGER IN THE LOW CLOUDS UNTIL
MIDDAY WITH THE INVERSION TAKING LONGER TO MIX OUT THERE. AFTER 18Z
THE SITES SHOULD BE VFR. IN THE EVENING A CLIPPER SYSTEM WILL
APPROACH THAT SHOULD BRING SNOW IN NEAR THE END OF THE PERIOD. THE
SOUTHWARD EXTENT OF THIS IS FAIRLY UNCERTAIN SO WILL LEAVE OUT OF
KBMG.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...JH
SHORT TERM...RYAN/JH
LONG TERM....MK
AVIATION...CP
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
536 AM CST FRI JAN 27 2012
.AVIATION...
VFR WX IS EXPECTED THROUGH 20Z/27 WITH HIGH AND MID LEVEL CLOUDS.
AFT 20Z/27 CIGS WILL SLOWLY LOWER TO JUST ABOVE MVFR. TOP DOWN
SATURATION OF THE ATMOSPHERE WILL OCCUR FROM 21Z/27 TO 03Z/28 WITH
PRECIPITATION TURNING TO -SN AS THE LOWER ATMOSPHERE COOLS. ROUGHLY A
6 HR PERIOD OF MVFR CONDITIONS ARE EXPECTED THAT MAY BRIEFLY GO TO
IFR. CONDITIONS SHOULD IMPROVE AGAIN TO VFR 03Z/28 TO 09Z/28.
..08..
&&
.PREV DISCUSSION... /ISSUED 312 AM CST FRI JAN 27 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS A STORM SYSTEM OVER THE EASTERN GREAT LAKES
MOVING INTO NEW ENGLAND. WEAK LOWS WERE LOCATED NEAR KBIS AND
KPHP. A WARM FRONT RAN FROM THE KPHP LOW TO NEAR KYKN AND THEN
SOUTH INTO EASTERN NEBRASKA. DEW POINTS WERE GENERALLY IN THE 20S
AND 30S ACROSS THE MIDWEST WITH A POCKET OF TEENS IN THE PLAINS.
SATELLITE TRENDS SHOW HIGH CLOUDS MOVING EAST TOWARD THE
MISSISSIPPI RIVER WITH MID AND SOME LOW CLOUDS IN THE PLAINS.
RADAR HAS VERY LIGHT PRECIPITATION OCCURRING IN THE CENTRAL AND
NORTHERN PLAINS.
SHORT TERM...TODAY AND TONIGHT...
THE KEY TO EVERYTHING LATER TODAY AND TONIGHT WILL BE WHEN DOES
SATURATION OCCUR. VERIFICATION OF THE MODELS THROUGH 06Z SHOW THEY
ARE WAY OVERDONE ON THE AMOUNT OF QPF. ADDITIONALLY...THEY ALL
INITIALIZED TOO MOIST IN THE LOW LEVELS AND HAD THE STRENGTH OF THE
PLAINS SFC RIDGE TOO STRONG. ALL THIS PLAYS SIGNIFICANTLY INTO
PRECIPITATION AMOUNTS IN THE NEXT 24 HRS.
OVERALL FORCING AND 850-700MB CONDENSATION PRESSURE DEFICITS FROM
THE RUC HAVE BEEN QUITE USEFUL IN DEPICTING WHERE PRECIPITATION
HAS BEEN OCCURRING IN THE PLAINS SO FAR. HOWEVER...IT TOO IS A BIT
OVERLY MOIST ON ITS INITIALIZATION AT 06Z.
THE MORNING HOURS WILL BE DRY WITH INCREASING CLOUDS. DURING THIS
TIME TEMPERATURES WILL RESPOND REASONABLE WELL TO THE WAA THAT
WILL BE OCCURRING AND ALLOW TEMPERATURES TO GET ABOVE NORMAL.
CAREFUL EXTRAPOLATION OF THE 12 HR RUC FCST SUGGESTS PRECIPITATION
ADVECTING OR DEVELOPING ROUGHLY WEST OF A DUBUQUE TO KEOKUK LINE
DURING THE FIRST HALF OF THE AFTERNOON. FCST SOUNDINGS FROM THE
RUC AND OTHER MODELS SUGGEST THAT MUCH OF THE FORCING WILL GO INTO
SATURATION. THE WARM TEMPERATURES INDICATE THAT THE PRECIPITATION
SHOULD INITIALLY START OUT AS RAIN. HOWEVER...EVAPORATIVE COOLING
WILL QUICKLY DROP THE LOWER ATMOSPHERE BELOW FREEZING. SO THE
PRECIPITATION WILL START OUT AS RAIN AND QUICKLY CHANGE TO SNOW
WITH A BRIEF PERIOD OF A MIX.
BY 00Z...6 PM...A WAA WING OF PRECIPITATION SHOULD COVER ALL BUT
THE FAR EASTERN REACHES OF THE CWFA. SNOW AMOUNTS BY EARLY EVENING
WILL RANGE FROM ZERO TO A DUSTING.
BASED ON THE OVERALL MOVEMENT OF THE FORCING...PRECIPITATION
SHOULD LAST ABOUT 6-9 HRS AT ANY ONE LOCATION ONCE IT BEGINS.
PRECIPITATION SHOULD BE WIDESPREAD ACROSS THE CWFA DURING THE
EARLY EVENING WITH IT ENDING FROM WEST TO EAST AFTER 9 PM.
PRECIPITATION SHOULD LINGER PAST MIDNIGHT OVER ROUGHLY THE EASTERN
HALF OF THE CWFA BEFORE ENDING BY SUNRISE SATURDAY.
OVERALL SNOW AMOUNTS FOR THIS EVENT SHOULD RANGE FROM A DUSTING TO
JUST OVER ONE HALF INCH.
.08..
LONG TERM...SATURDAY THROUGH NEXT THURSDAY...
NORTHWEST FLOW PATTERN WILL DOMINATE INTO MON. CLIPPER SYSTEM TO PASS
MAINLY TO OUR NORTH SAT NGT WITH SMALL CHC OF -SN WITH WARM
ADVECTION WING FAR N/NE COUNTIES. BETTER CHCS WILL RESIDE
FARTHER NORTH ACROSS PORTIONS OF MN AND WI ALONG AND LEFT OF THE
TRACK IN THE COLDER AIR. AS IT PASSES TO OUR N/E SAT NGT IT WILL SEND
COLD FRONT DOWN THROUGH REGION RESULTING IN COLDER TEMPS (NEAR TO
A LITTLE BELOW NORMAL) ON SUNDAY. NEXT WEAK CLIPPER SYSTEM
AND ATTENDANT WARM ADVECTION WING LOOKS TO PASS WELL NORTH OF REGION
SUN NGT INTO MON. STRENGTHENING SOUTHERLY SFC FLOW WILL BRING WELL
ABOVE NORMALS TEMPS BACK INTO REGION. HAVE BUMPED UP HIGHS SEVERAL
DEGS ON MON... BUT IF 00Z GFS AND HI-RES ECMWF VERIFY ON MIXING DEPTH
AND THERMAL FIELDS THEN WOULD NEED TO RAISE FURTHER WITH BOTH
SUPPORTIVE OF M/U 40S IN THE NORTH TO AROUND 57F IN THE FAR SOUTH.
TUE-THU... ZONAL FLOW LOOKS TO DOMINATE ACROSS MUCH OF THE CONUS WITH
TEMPS ABOVE NORMAL IN MP AIRMASS. MODELS STILL VARY ON EVOLUTION
OF PACIFIC SHORTWAVE ON TUE WITH THE ECMWF AND GEM MORE PROGRESSIVE
AND NORTHERLY WHILE THE GFS AND UKMET ARE MUCH SLOWER AND MORE
SOUTHERLY. DPROG/DT OF GFS SHOWS CONSIDERABLE RUN TO RUN VARIANCE WHILE
ECMWF MORE STABLE... AND THUS FAVORED. LOW LEVEL MOISTURE LOOKS
FAIRLY SHALLOW AND TRANSPORT VECTORS VEER IN TIME ON TUE SHUNTING
BETTER LOW LEVEL MOISTURE TO OUR S/E. HAVE THEREFORE TRIMMED BACK POPS
TO MOSTLY SLIGHT CHC. PATTERN LOOKS TO SHIFT BACK TO HIGHLY AMPLIFIED
ONE BY LATE WEEK INTO NEXT WEEKEND WITH RETURN OF COLDER AIR. DURING
THIS TRANSITION THERE WILL BE AT LEAST A COUPLE OF PCPN CHCS (RAIN/SNOW)
THU-SAT. ..05..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
312 AM CST FRI JAN 27 2012
.SYNOPSIS...
06Z SFC ANALYSIS HAS A STORM SYSTEM OVER THE EASTERN GREAT LAKES
MOVING INTO NEW ENGLAND. WEAK LOWS WERE LOCATED NEAR KBIS AND
KPHP. A WARM FRONT RAN FROM THE KPHP LOW TO NEAR KYKN AND THEN
SOUTH INTO EASTERN NEBRASKA. DEW POINTS WERE GENERALLY IN THE 20S
AND 30S ACROSS THE MIDWEST WITH A POCKET OF TEENS IN THE PLAINS.
SATELLITE TRENDS SHOW HIGH CLOUDS MOVING EAST TOWARD THE
MISSISSIPPI RIVER WITH MID AND SOME LOW CLOUDS IN THE PLAINS.
RADAR HAS VERY LIGHT PRECIPITATION OCCURRING IN THE CENTRAL AND
NORTHERN PLAINS.
&&
.SHORT TERM...TODAY AND TONIGHT...
THE KEY TO EVERYTHING LATER TODAY AND TONIGHT WILL BE WHEN DOES
SATURATION OCCUR. VERIFICATION OF THE MODELS THROUGH 06Z SHOW THEY
ARE WAY OVERDONE ON THE AMOUNT OF QPF. ADDITIONALLY...THEY ALL
INITIALIZED TOO MOIST IN THE LOW LEVELS AND HAD THE STRENGTH OF THE
PLAINS SFC RIDGE TOO STRONG. ALL THIS PLAYS SIGNIFICANTLY INTO
PRECIPITATION AMOUNTS IN THE NEXT 24 HRS.
OVERALL FORCING AND 850-700MB CONDENSATION PRESSURE DEFICITS FROM
THE RUC HAVE BEEN QUITE USEFUL IN DEPICTING WHERE PRECIPITATION
HAS BEEN OCCURRING IN THE PLAINS SO FAR. HOWEVER...IT TOO IS A BIT
OVERLY MOIST ON ITS INITIALIZATION AT 06Z.
THE MORNING HOURS WILL BE DRY WITH INCREASING CLOUDS. DURING THIS
TIME TEMPERATURES WILL RESPOND REASONABLE WELL TO THE WAA THAT
WILL BE OCCURRING AND ALLOW TEMPERATURES TO GET ABOVE NORMAL.
CAREFUL EXTRAPOLATION OF THE 12 HR RUC FCST SUGGESTS PRECIPITATION
ADVECTING OR DEVELOPING ROUGHLY WEST OF A DUBUQUE TO KEOKUK LINE
DURING THE FIRST HALF OF THE AFTERNOON. FCST SOUNDINGS FROM THE
RUC AND OTHER MODELS SUGGEST THAT MUCH OF THE FORCING WILL GO INTO
SATURATION. THE WARM TEMPERATURES INDICATE THAT THE PRECIPITATION
SHOULD INITIALLY START OUT AS RAIN. HOWEVER...EVAPORATIVE COOLING
WILL QUICKLY DROP THE LOWER ATMOSPHERE BELOW FREEZING. SO THE
PRECIPITATION WILL START OUT AS RAIN AND QUICKLY CHANGE TO SNOW
WITH A BRIEF PERIOD OF A MIX.
BY 00Z...6 PM...A WAA WING OF PRECIPITATION SHOULD COVER ALL BUT
THE FAR EASTERN REACHES OF THE CWFA. SNOW AMOUNTS BY EARLY EVENING
WILL RANGE FROM ZERO TO A DUSTING.
BASED ON THE OVERALL MOVEMENT OF THE FORCING...PRECIPITATION
SHOULD LAST ABOUT 6-9 HRS AT ANY ONE LOCATION ONCE IT BEGINS.
PRECIPITATION SHOULD BE WIDESPREAD ACROSS THE CWFA DURING THE
EARLY EVENING WITH IT ENDING FROM WEST TO EAST AFTER 9 PM.
PRECIPITATION SHOULD LINGER PAST MIDNIGHT OVER ROUGHLY THE EASTERN
HALF OF THE CWFA BEFORE ENDING BY SUNRISE SATURDAY.
OVERALL SNOW AMOUNTS FOR THIS EVENT SHOULD RANGE FROM A DUSTING TO
JUST OVER ONE HALF INCH.
..08..
.LONG TERM...SATURDAY THROUGH NEXT THURSDAY...
NORTHWEST FLOW PATTERN WILL DOMINATE INTO MON. CLIPPER SYSTEM TO PASS
MAINLY TO OUR NORTH SAT NGT WITH SMALL CHC OF -SN WITH WARM
ADVECTION WING FAR N/NE COUNTIES. BETTER CHCS WILL RESIDE
FARTHER NORTH ACROSS PORTIONS OF MN AND WI ALONG AND LEFT OF THE
TRACK IN THE COLDER AIR. AS IT PASSES TO OUR N/E SAT NGT IT WILL SEND
COLD FRONT DOWN THROUGH REGION RESULTING IN COLDER TEMPS (NEAR TO
A LITTLE BELOW NORMAL) ON SUNDAY. NEXT WEAK CLIPPER SYSTEM
AND ATTENDANT WARM ADVECTION WING LOOKS TO PASS WELL NORTH OF REGION
SUN NGT INTO MON. STRENGTHENING SOUTHERLY SFC FLOW WILL BRING WELL
ABOVE NORMALS TEMPS BACK INTO REGION. HAVE BUMPED UP HIGHS SEVERAL
DEGS ON MON... BUT IF 00Z GFS AND HI-RES ECMWF VERIFY ON MIXING DEPTH
AND THERMAL FIELDS THEN WOULD NEED TO RAISE FURTHER WITH BOTH
SUPPORTIVE OF M/U 40S IN THE NORTH TO AROUND 57F IN THE FAR SOUTH.
TUE-THU... ZONAL FLOW LOOKS TO DOMINATE ACROSS MUCH OF THE CONUS WITH
TEMPS ABOVE NORMAL IN MP AIRMASS. MODELS STILL VARY ON EVOLUTION
OF PACIFIC SHORTWAVE ON TUE WITH THE ECMWF AND GEM MORE PROGRESSIVE
AND NORTHERLY WHILE THE GFS AND UKMET ARE MUCH SLOWER AND MORE
SOUTHERLY. DPROG/DT OF GFS SHOWS CONSIDERABLE RUN TO RUN VARIANCE WHILE
ECMWF MORE STABLE... AND THUS FAVORED. LOW LEVEL MOISTURE LOOKS
FAIRLY SHALLOW AND TRANSPORT VECTORS VEER IN TIME ON TUE SHUNTING
BETTER LOW LEVEL MOISTURE TO OUR S/E. HAVE THEREFORE TRIMMED BACK POPS
TO MOSTLY SLIGHT CHC. PATTERN LOOKS TO SHIFT BACK TO HIGHLY AMPLIFIED
ONE BY LATE WEEK INTO NEXT WEEKEND WITH RETURN OF COLDER AIR. DURING
THIS TRANSITION THERE WILL BE AT LEAST A COUPLE OF PCPN CHCS (RAIN/SNOW)
THU-SAT. ..05..
&&
.PREV DISCUSSION... /ISSUED 1149 PM CST THU JAN 26 2012/
AVIATION...
COLD FRONTAL PASSAGE THIS AFTERNOON BRINGING DRIER AIR INTO THE
AREA WITH ALL TERMINALS VFR. CLEAR SKIES AND SUBSIDENCE TO PERSIST
UNTIL DAYBREAK. CLEAR SKIES AND VISIBILITY 7+ MILES TO CONTINUE
UNTIL 15Z FRIDAY WITH LIGHT NW WINDS OF 5-10 MPH. INCREASING HIGH
CLOUDS AOA 10K AGL AFTER 15Z WITH CIGS DOWN TO ~6K AGL WITH SNOW
SHOWERS AFTER 26/20Z ALL TERMINALS. SEVERAL HOURS OF MVFR TO
HIGHER END IFR CONDITIONS POSSIBLE UNTIL 27/06Z WITH LIGHT SNOW.
.NICHOLS..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
544 PM CST SAT JAN 28 2012
.SHORT TERM /TODAY THROUGH MONDAY/
SURFACE HIGH PRESSURE RESIDES TO THE IMMEDIATE SOUTH OF THE AREA
THIS AFTERNOON PROVIDING LIGHT NORTHWEST WINDS ACROSS THE BULK OF
THE FORECAST AREA. THE AIRMASS IS QUITE DRY AND AFTERNOON MIXING
HAS CREATED VERY LOW DEW POINTS ACROSS THE AREA THAT HAVE PUSHED
RELATIVE HUMIDITIES INTO THE 15 TO 20 PERCENT RANGE ACROSS A LARGE
PORTION OF THE EAST. WITH WIND GUSTS BETWEEN 20 AND 30 MPH, THIS
HAS BROUGHT CONDITIONS CLOSE TO RED FLAG THIS AFTERNOON. IT IS
LIKELY SOME LOCATIONS OF THE EAST CENTRAL INCLUDING PRATT AND
STAFFORD COUNTIES MIGHT REACH THE RED FLAG RH AND WIND ELEMENTS
LOCALLY, BUT IT DOES NOT APPEAR A TIME THRESHOLD FOR TRUE RED FLAG
WARNING WILL BE MET SINCE TEMPERATURES WILL BEGIN TO RADIATIONAL
COOL RAPIDLY BY 5 PM.
THE MODELS SHOW FAIRLY SIMILAR FIELDS OVER THE NEXT COUPLE OF DAYS
ON THE SYNOPTIC AND MESOSCALE. THE WARM UP THAT WAS FORECAST IS STILL
EXPECTED. DEW POINTS SHOULD INCREASE FROM THE VERY LOW VALUES WE
OBSERVED THIS AFTERNOON, AS THE SURFACE ANTICYCLONE DRIFTS INTO THE
LOWER MISSISSIPPI VALLEY. MAINLY SUNNY SKIES ARE ANTICIPATED AS
WELL, ALTHOUGH SOME CIRRUS MY BE OFF TO THE NORTHEAST ASSOCIATED THE
NORTHWESTERLY ORIENTED JET. AS THE UPPER FLOW SLOWLY BECOMES ZONAL
OVER WESTERN KANSAS, A WEAK SURFACE TROUGH WILL REMAIN ANCHORED
ACROSS EASTERN COLORADO ALLOWING SOUTHWEST TO SOUTH WINDS OVER
ACROSS OUR COUNTIES. BOUNDARY LAYER THETA-E WILL INCREASE THROUGH
THE OVERNIGHT INTO MONDAY PERIOD ALLOWING AFTERNOON HIGHS TO RISE
THROUGH THE LOW 50S ON SUNDAY AND THE UPPER 50S AND LOW 60S ON
MONDAY. LOWS WILL PROBABLY NOT GET QUITE AS COLD WITH SOME LIGHT
WINDS EXPECTED OVERNIGHT AND LESS DRY AIR. STILL - TEMPERATURES
TONIGHT MAY REACH THE UPPER TEENS WITH VERY STRONG RADIATIONAL
COOLING, BUT THETA-E INCREASE ON SUNDAY SHOULD LIMIT COOLING TO THE
UPPER 20S ON SUNDAY NIGHT.
DAYS 3-7...
WESTERLY FLOW WILL IMPROVE EARLY NEXT AS A SERIES OF UPPER LEVEL
DISTURBANCES MOVE OUT OF THE PACIFIC AND ACROSS THE WESTERN/CENTRAL
UNITED STATES. THE FIRST UPPER LEVEL TROUGH REMAINS ON TRACK TO
CROSS OUT OF THE ROCKIES AND INTO THE CENTRAL PLAINS ON TUESDAY WITH
THE NEXT, STRONGER UPPER LEVEL TROUGH FORECAST TO DIG FURTHER SOUTH
INTO THE SOUTHERN PLAINS BY EARLY THURSDAY. FOR WESTERN KANSAS THE
MOISTURE WITH EACH OF THESE SYSTEMS APPEAR TO BE CONFINED MAINLY IN
THE MID TO UPPER LEVELS. ON TUESDAY THERE WILL BE SOME UPPER LEVEL
JET DYNAMICS IN THE NORTH WHILE ON THURSDAY THERE WILL BE BETTER MID
LEVEL LAPSE RATES, 700MB IMPROVING FRONTOGENESIS, AND 850MB WARM AIR
ADVECTION DEVELOPING ACROSS PORTIONS OF SOUTH CENTRAL KANSAS AHEAD
OF THIS WAVE. MAIN CONCERN THIS SECOND UPPER LEVEL TROUGH IS THE
EVOLUTION AND TRACK GIVEN THAT THE NEW GFS AND ECMWF ARE NOW
DIFFERING FROM PREVIOUS RUNS. AS A RESULT CONFIDENCE AFTER DAY 5 IS
LOW SO GIVEN THIS WILL STAY CLOSE TO THE PREVIOUS FORECAST AND LEAVE
THE LATER PERIODS FREE FROM ANY TYPE OF PRECIPITATION.
AS FOR TEMPERATURES...A WEAK COLD FRONT WILL BRIEFLY RETURN ON
TUESDAY BEHIND OUR FIRST UPPER LEVEL TROUGH. TEMPERATURES THEN
BRIEFLY WARM MID TO LATE WEEK UNTIL OUR ANOTHER COLD FRONT RETURNS
ON FRIDAY AS THE SECOND, STRONGER, UPPER LEVEL TROUGH CROSSES THE
CENTRAL/SOUTHERN PLAINS.
$$
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
WEST WINDS WILL INCREASE INTO THE 15 TO NEAR 20 KT RANGE THIS
AFTERNOON BASED ON MIXED LAYER WINDS FROM THE RUC AND NAM MODEL
SOUNDINGS. THESE GUSTY AFTERNOON WINDS WILL THEN SUBSIDE AFTER
SUNSET AS THE ATMOSPHERE DECOUPLES. MODELS SOUNDINGS TODAY ALSO
INDICATING VFR CONDITIONS THROUGHOUT THE PERIOD.
$$
18
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 537 PM CST SAT JAN 28 2012
A WEAK TROUGH OF LOW PRESSURE WILL DEVELOP ACROSS THE NORTHERN
PLAINS BY SUNDAY. LIGHT NORTHWEST WINDS TONIGHT WILL TRANSITION TO
5 TO 15 KT SOUTHWESTERLY WINDS BY 15Z SUNDAY. VFR CONDITONS CAN BE
EXPECTED.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 19 59 27 64 / 0 0 0 0
GCK 19 59 25 64 / 0 0 0 0
EHA 23 59 27 65 / 0 0 0 0
LBL 22 58 27 65 / 0 0 0 0
HYS 20 58 26 65 / 0 0 0 0
P28 21 58 27 63 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AVIATION...99
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1129 AM CST FRI JAN 27 2012
.AVIATION...
FOR THE 18Z TAF ISSUANCE...
A COLD FRONT HAS MOVED ACROSS THE TAF SITES THIS MORNING SHIFTING
THE WINDS TO THE NORTH. SUSTAINED WINDS OF 25 TO 35 KNOTS ARE
ANTICIPATED INTO THE LATE AFTERNOON WITH SOME GUSTS OVER 40 KNOTS.
MID TO HIGH LEVEL CLOUDS HAVE DEVELOPED BEHIND THIS FRONT AND ARE
ANTICIPATED TO CREATE MOSTLY CLOUDY SKIES THROUGH EARLY THIS
EVENING. CLEARING SKIES AND DECREASED WIND SPEEDS ARE EXPECTED
OVERNIGHT TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 607 AM CST FRI JAN 27 2012/
SYNOPSIS...
IN APPLYING THE FORECAST FUNNEL, ONE WOULD START WITH THE 27.00Z 300
HPA SYNOPTIC MAP. A 100 KT JET EXTENDED FROM KMFR TO KLBF. THIS JET
WAS WELL UPSTREAM OF A HIGHLY AMPLIFIED MERIDIONAL TROUGH AXIS THAT
EXTENDED FROM ONTARIO INTO THE GULF OF MEXICO. A FASTER 135 TO 140 KT
JET LOCATED EAST OF THIS TROUGH AXIS ACROSS THE EASTERN UNITED STATES.
AT 500 HPA, A SHORTWAVE TROUGH WAS MOVING ACROSS THE NORTHERN ROCKIES.
THIS UPPER LEVEL FEATURE WAS USHERING IN A SURFACE COLD FRONT ACROSS
THE NORTHERN PLAINS AND INTO WYOMING. NOTHING TOO OUT OF THE ORDINARY WAS
OBSERVED AT 700 AND 850 HPA ACROSS THE CENTRAL PLAINS EXCEPT A DRY THERMODYNAMIC
PROFILE.
DISCUSSION...
DAYS 1-2...
TODAY:
FORECAST SOUNDINGS FROM THE 27.00Z GFS AND 27.00Z NAM BOTH AGREE ON
RAPID SATURATION BETWEEN 600 AND 400 HPA IN ASSOCIATION WITH MID LEVEL
MOISTURE ADVECTION AHEAD OF AN APPROACHING UPPER LEVEL SHORTWAVE TROUGH
THIS MORNING. BELOW 600 HPA, ALL MODELS SHOW THE ATMOSPHERIC PROFILE
BECOMING MIXED (PARTICULARLY BELOW 800 HPA) AND AS A RESULT IS RELATIVELY
DRY. WITH THE EXCEPTION OF THE 27.00Z GFS, ALL MODELS BASICALLY HAVE
NO QPF ACROSS SOUTHWEST KANSAS TODAY. ALSO CHECKED THE ARW/NMM/HRRR
WHICH PAINT AN ALMOST NEGLIGIBLE QPF SIGNAL. AS A RESULT, HAVE REDUCED
POPS TO BELOW 15 PERCENT. SOME VIRGA IS POSSIBLE THIS MORNING BUT OTHER
THAN THAT, THE FORECAST WILL REMAIN DRY FOR TODAY.
SECOND SENSIBLE WEATHER CONCERN AND RATHER THE MOST SIGNIFICANT IS WINDS.
AS THE ABOVE MENTIONED SHORTWAVE TROUGH MOVES ACROSS KANSAS, THIS FEATURE
WILL PUSH A SURFACE COLD FRONT ACROSS THE REGION THIS MORNING. IN THE
WAKE OF THE FRONT, A TIGHT PRESSURE GRADIENT AND MIXING FROM ON AVERAGE
800 HPA TO THE SURFACE WILL RESULT IN MOMENTUM TRANSFER FROM THE TOP
OF THE BOUNDARY LAYER TO THE GROUND. BUFKIT SOUNDINGS SHOW ABOUT 40
KT AT THE TOP OF THE MIXING LAYER. AS WITH THE PREVIOUS DAY SHIFT, I
HAVE UTILIZED THE MIXED LAYER WIND SMART TOOL WHICH BROUGHT IT REASONABLE
WINDS SPEEDS INTO THE GRIDS. MOS/LAMP GUIDANCE ALSO SUGGESTS SIMILAR
WIND MAGNITUDE AS OUTPUTTED BY TOOL. THE ONGOING NPW LOOKS VERY REASONABLE
ALTHOUGH I DID ADJUST THE START TIME EARLIER AS THE HRRR MODEL IS SUGGESTING
NEAR CRITERIA WIND SPEEDS AT THE END OF THE MODEL RUN (EARLIER). WINDS
AROUND 29-33 KT WITH GUSTS TO 40-45 KT ARE FORECAST TODAY. WINDS WILL
DECREASE SIGNIFICANTLY TOWARDS SUNSET.
TONIGHT:
HIGH PRESSURE WILL SLIDE ACROSS KANSAS TONIGHT AND INTO TOMORROW MORNING.
FORECAST SOUNDINGS SHOW RAPID DRYING IN THE MID LEVELS AFTER 00Z. WITH
CLEARING SKIES AND RELATIVELY LIGHT WINDS, AM EXPECTING COOL OVERNIGHT
LOWS WITH TEENS TO LOW 20S DEG F ACROSS MUCH OF THE REGION. SUBSIDENCE
AND HIGH PRESSURE IN THE WAKE OF THE DEPARTING TROUGH WILL KEEP POPS
AT ZERO BY 06Z TONIGHT.
SATURDAY/SATURDAY NIGHT:
EXTREMELY QUIET WEATHER IS EXPECTED AS NORTHWESTERLY FLOW ALOFT PREVAILS
ACROSS THE SUNFLOWER STATE THROUGH THE BEGINNING OF THE WEEKEND. MUCH
WEAKER WESTERLY TO NORTHWESTERLY WINDS AROUND 10 TO 15 KT ARE EXPECTED
SATURDAY. TEMPERATURES WILL BE FAIRLY SEASONABLE TO SLIGHT ABOVE
WITH MID TO UPPER 40S DEG F EXPECTED. SKIES SHOULD BE FAIRLY
CLEAR. LOWS INTO SUNDAY MORNING ARE EXPECTED TO BE NEAR NORMAL...LOW
20S DEG F.
DAYS 3-7...
A PROGRESSIVE, ZONAL SYNOPTIC SCALE PATTERN IS EXPECTED TO PREVAIL THROUGH
THE MEDIUM RANGE YIELDING WEAK COLD FRONT PASSAGES AND AN OVERALL CONTINUED
ABOVE-AVERAGE TEMPERATURE FORECAST.
A LEE TROUGH WILL DEVELOP SUNDAY AS AN UPPER LEVEL TROUGH BEGINS TO
ENTER THE PACIFIC NORTHWEST REGION. REMNANT, COOL POLAR AIRMASS OVER
THE CENTRAL CONUS WILL LOSE ITS GRIP WITH INCREASING LOW LEVEL THICKNESSES
AND SUBSEQUENT WARMER TEMPERATURES OVER THE WESTERN PLAINS. HIGHS SUNDAY
SHOULD WARM WELL INTO THE 50S AND HAVE INCREASED THE FORECAST HIGHS
ABOUT 2 TO 3 DEGREES ON AVERAGE ACROSS THE DDC FORECAST AREA.
MONDAY CERTAINLY LOOKS TO BE A WARM DAY WITH THE LEE TROUGH OVER EASTERN
COLORADO AND ADJACENT WESTERN KANSAS DOWN TO ABOUT 1002-1004MB. DEPENDING
ON THE DEGREE OF BOUNDARY LAYER MIXING, A VERY WARM DAY COULD RESULT...ESPECIALLY
ACROSS THE SOUTHWESTERN COUNTIES (HIGHER ELEVATION RESULTING IN BETTER
POTENTIAL FOR DEEPER MIXING). THE ALLBLEND GUIDANCE GIVES HIGHS OF 59-60F
FOR MUCH OF THE FORECAST AREA BUT SOME MID 60S CANNOT BE RULED OUT IN
THIS VERY WARM PATTERN AHEAD OF A LOW AMPLITUDE ZONAL SHORTWAVE TROUGH.
THIS AFOREMENTIONED TROUGH WILL MOVE FAST ACROSS THE CENTRAL PLAINS
MONDAY NIGHT AND TUESDAY SHOULD BE A BIT COOLER...YET STILL QUITE A
BIT ABOVE THE CLIMATOLOGICAL AVERAGE OF LOWER-MID 40S FOR SOUTHWEST
KANSAS TO END THE MONTH OF JANUARY. AFTER THAT...THERE IS SOME UNCERTAINTY
IN HOW THE PATTERN WILL EVOLVE. THE GFS SHOWS AMPLIFICATION TAKING PLACE
QUICKLY OVER THE WESTERN CONUS WITH A RIDGE AXIS OVER THE WEST COAST
AND SUBSEQUENT TROUGH OVER THE CENTRAL CONUS. THIS IS A COOLER PATTERN,
HOWEVER THE NEW ECMWF MODEL SHOWS A MUCH WARMER SCENARIO FOR MID-WEEK
WITH A MUCH LOWER AMPLITUDE RIDGE-TROUGH SETUP OVER THE WESTERN AND
CENTRAL CONUS. THE ECMWF MODEL DOES INDEED AMPLIFY THE SYNOPTIC SCALE
PATTERN RATHER SUBSTANTIALLY BY THURSDAY, RESULTING IN A MEAN TROUGH/LOWER
HEIGHTS OVER THE CENTRAL CONUS...SO THE ABOVE/MUCH ABOVE TEMPERATURES
WE WILL BE SEEING SUNDAY THROUGH WEDNESDAY MAY END BY THURSDAY- FRIDAY
OF NEXT WEEK (FEB 2-3) DEPENDING ON HOW THE AMPLIFICATION OF THE LARGE
SCALE PATTERN EVOLVES OVER THE CONUS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 18 49 21 56 / 0 0 0 0
GCK 18 47 20 55 / 0 0 0 0
EHA 19 49 23 59 / 0 0 0 0
LBL 18 49 21 57 / 0 0 0 0
HYS 18 47 20 55 / 0 0 0 0
P28 20 49 23 56 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM CST /5 PM MST/ THIS EVENING FOR KSZ030-
031-043>046-061>066-074>081-084>090.
&&
$$
FN12/42/42
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
607 AM CST FRI JAN 27 2012
.AVIATION...
FOR THE 12Z TAF ISSUANCE...
VERY STRONG NORTH WINDS WILL AFFECT ALL THREE TERMINALS TODAY
(GCK, DDC, HYS) AS A COLD FRONT MOVES SOUTH ACROSS THE CENTRAL
PLAINS. THE STRONGEST WINDS WILL OCCUR BETWEEN ROUGHLY 17Z AND 21Z
WHICH IS WHEN 30 TO 35 KNOTS SUSTAINED WILL BE OCCURRING. A FEW
WIND GUSTS IN THE 45 TO 50 KNOT RANGE WILL ALSO BE POSSIBLE. VFR
CONDITIONS ARE EXPECTED TO PREVAIL WITH THE PASSAGE OF THE COLD
FRONT ACROSS SOUTHWEST KANSAS. -UMSCHEID
&&
.PREV DISCUSSION... /ISSUED 324 AM CST FRI JAN 27 2012/
SYNOPSIS...
IN APPLYING THE FORECAST FUNNEL, ONE WOULD START WITH THE 27.00Z 300
HPA SYNOPTIC MAP. A 100 KT JET EXTENDED FROM KMFR TO KLBF. THIS JET
WAS WELL UPSTREAM OF A HIGHLY AMPLIFIED MERIDIONAL TROUGH AXIS THAT
EXTENDED FROM ONTARIO INTO THE GULF OF MEXICO. A FASTER 135 TO 140 KT
JET LOCATED EAST OF THIS TROUGH AXIS ACROSS THE EASTERN UNITED STATES.
AT 500 HPA, A SHORTWAVE TROUGH WAS MOVING ACROSS THE NORTHERN ROCKIES.
THIS UPPER LEVEL FEATURE WAS USHERING IN A SURFACE COLD FRONT ACROSS
THE NORTHERN PLAINS AND INTO WYOMING. NOTHING TOO OUT OF THE ORDINARY WAS
OBSERVED AT 700 AND 850 HPA ACROSS THE CENTRAL PLAINS EXCEPT A DRY THERMODYNAMIC
PROFILE. -SUGDEN
DISCUSSION...
DAYS 1-2...
TODAY:
FORECAST SOUNDINGS FROM THE 27.00Z GFS AND 27.00Z NAM BOTH AGREE ON
RAPID SATURATION BETWEEN 600 AND 400 HPA IN ASSOCIATION WITH MID LEVEL
MOISTURE ADVECTION AHEAD OF AN APPROACHING UPPER LEVEL SHORTWAVE TROUGH
THIS MORNING. BELOW 600 HPA, ALL MODELS SHOW THE ATMOSPHERIC PROFILE
BECOMING MIXED (PARTICULARLY BELOW 800 HPA) AND AS A RESULT IS RELATIVELY
DRY. WITH THE EXCEPTION OF THE 27.00Z GFS, ALL MODELS BASICALLY HAVE
NO QPF ACROSS SOUTHWEST KANSAS TODAY. ALSO CHECKED THE ARW/NMM/HRRR
WHICH PAINT AN ALMOST NEGLIGIBLE QPF SIGNAL. AS A RESULT, HAVE REDUCED
POPS TO BELOW 15 PERCENT. SOME VIRGA IS POSSIBLE THIS MORNING BUT OTHER
THAN THAT, THE FORECAST WILL REMAIN DRY FOR TODAY.
SECOND SENSIBLE WEATHER CONCERN AND RATHER THE MOST SIGNIFICANT IS WINDS.
AS THE ABOVE MENTIONED SHORTWAVE TROUGH MOVES ACROSS KANSAS, THIS FEATURE
WILL PUSH A SURFACE COLD FRONT ACROSS THE REGION THIS MORNING. IN THE
WAKE OF THE FRONT, A TIGHT PRESSURE GRADIENT AND MIXING FROM ON AVERAGE
800 HPA TO THE SURFACE WILL RESULT IN MOMENTUM TRANSFER FROM THE TOP
OF THE BOUNDARY LAYER TO THE GROUND. BUFKIT SOUNDINGS SHOW ABOUT 40
KT AT THE TOP OF THE MIXING LAYER. AS WITH THE PREVIOUS DAY SHIFT, I
HAVE UTILIZED THE MIXED LAYER WIND SMART TOOL WHICH BROUGHT IT REASONABLE
WINDS SPEEDS INTO THE GRIDS. MOS/LAMP GUIDANCE ALSO SUGGESTS SIMILAR
WIND MAGNITUDE AS OUTPUTTED BY TOOL. THE ONGOING NPW LOOKS VERY REASONABLE
ALTHOUGH I DID ADJUST THE START TIME EARLIER AS THE HRRR MODEL IS SUGGESTING
NEAR CRITERIA WIND SPEEDS AT THE END OF THE MODEL RUN (EARLIER). WINDS
AROUND 29-33 KT WITH GUSTS TO 40-45 KT ARE FORECAST TODAY. WINDS WILL
DECREASE SIGNIFICANTLY TOWARDS SUNSET.
TONIGHT:
HIGH PRESSURE WILL SLIDE ACROSS KANSAS TONIGHT AND INTO TOMORROW MORNING.
FORECAST SOUNDINGS SHOW RAPID DRYING IN THE MID LEVELS AFTER 00Z. WITH
CLEARING SKIES AND RELATIVELY LIGHT WINDS, AM EXPECTING COOL OVERNIGHT
LOWS WITH TEENS TO LOW 20S DEG F ACROSS MUCH OF THE REGION. SUBSIDENCE
AND HIGH PRESSURE IN THE WAKE OF THE DEPARTING TROUGH WILL KEEP POPS
AT ZERO BY 06Z TONIGHT.
SATURDAY/SATURDAY NIGHT:
EXTREMELY QUIET WEATHER IS EXPECTED AS NORTHWESTERLY FLOW ALOFT PREVAILS
ACROSS THE SUNFLOWER STATE THROUGH THE BEGINNING OF THE WEEKEND. MUCH
WEAKER WESTERLY TO NORTHWESTERLY WINDS AROUND 10 TO 15 KT ARE EXPECTED
SATURDAY. TEMPERATURES WILL BE FAIRLY SEASONABLE TO SLIGHT ABOVE
WITH MID TO UPPER 40S DEG F EXPECTED. SKIES SHOULD BE FAIRLY
CLEAR. LOWS INTO SUNDAY MORNING ARE EXPECTED TO BE NEAR NORMAL...LOW
20S DEG F. -SUGDEN
DAYS 3-7...
A PROGRESSIVE, ZONAL SYNOPTIC SCALE PATTERN IS EXPECTED TO PREVAIL THROUGH
THE MEDIUM RANGE YIELDING WEAK COLD FRONT PASSAGES AND AN OVERALL CONTINUED
ABOVE-AVERAGE TEMPERATURE FORECAST.
A LEE TROUGH WILL DEVELOP SUNDAY AS AN UPPER LEVEL TROUGH BEGINS TO
ENTER THE PACIFIC NORTHWEST REGION. REMNANT, COOL POLAR AIRMASS OVER
THE CENTRAL CONUS WILL LOSE ITS GRIP WITH INCREASING LOW LEVEL THICKNESSES
AND SUBSEQUENT WARMER TEMPERATURES OVER THE WESTERN PLAINS. HIGHS SUNDAY
SHOULD WARM WELL INTO THE 50S AND HAVE INCREASED THE FORECAST HIGHS
ABOUT 2 TO 3 DEGREES ON AVERAGE ACROSS THE DDC FORECAST AREA.
MONDAY CERTAINLY LOOKS TO BE A WARM DAY WITH THE LEE TROUGH OVER EASTERN
COLORADO AND ADJACENT WESTERN KANSAS DOWN TO ABOUT 1002-1004MB. DEPENDING
ON THE DEGREE OF BOUNDARY LAYER MIXING, A VERY WARM DAY COULD RESULT...ESPECIALLY
ACROSS THE SOUTHWESTERN COUNTIES (HIGHER ELEVATION RESULTING IN BETTER
POTENTIAL FOR DEEPER MIXING). THE ALLBLEND GUIDANCE GIVES HIGHS OF 59-60F
FOR MUCH OF THE FORECAST AREA BUT SOME MID 60S CANNOT BE RULED OUT IN
THIS VERY WARM PATTERN AHEAD OF A LOW AMPLITUDE ZONAL SHORTWAVE TROUGH.
THIS AFOREMENTIONED TROUGH WILL MOVE FAST ACROSS THE CENTRAL PLAINS
MONDAY NIGHT AND TUESDAY SHOULD BE A BIT COOLER...YET STILL QUITE A
BIT ABOVE THE CLIMATOLOGICAL AVERAGE OF LOWER-MID 40S FOR SOUTHWEST
KANSAS TO END THE MONTH OF JANUARY. AFTER THAT...THERE IS SOME UNCERTAINTY
IN HOW THE PATTERN WILL EVOLVE. THE GFS SHOWS AMPLIFICATION TAKING PLACE
QUICKLY OVER THE WESTERN CONUS WITH A RIDGE AXIS OVER THE WEST COAST
AND SUBSEQUENT TROUGH OVER THE CENTRAL CONUS. THIS IS A COOLER PATTERN,
HOWEVER THE NEW ECMWF MODEL SHOWS A MUCH WARMER SCENARIO FOR MID-WEEK
WITH A MUCH LOWER AMPLITUDE RIDGE-TROUGH SETUP OVER THE WESTERN AND
CENTRAL CONUS. THE ECMWF MODEL DOES INDEED AMPLIFY THE SYNOPTIC SCALE
PATTERN RATHER SUBSTANTIALLY BY THURSDAY, RESULTING IN A MEAN TROUGH/LOWER
HEIGHTS OVER THE CENTRAL CONUS...SO THE ABOVE/MUCH ABOVE TEMPERATURES
WE WILL BE SEEING SUNDAY THROUGH WEDNESDAY MAY END BY THURSDAY- FRIDAY
OF NEXT WEEK (FEB 2-3) DEPENDING ON HOW THE AMPLIFICATION OF THE LARGE
SCALE PATTERN EVOLVES OVER THE CONUS. -UMSCHEID
AVIATION...
FOR THE 06Z TAF ISSUANCE...SOUTH TO SOUTHEAST WINDS AT 8 TO 15 KNOTS
WILL PERSIST AT THE TAF SITES THROUGH ABOUT 10Z. THE WINDS COULD OCCASIONALLY
BE GUSTY TO 20 KNOTS AS WELL. AFTER 10Z THE WINDS WILL DIMINISH AND
SWITCH TO THE SOUTHWEST AS A LOW PRESSURE TROUGH MOVES INTO THE AREA
FROM EASTERN COLORADO. A STRONG COLD FRONT WILL PUSH THROUGH WESTERN
KANSAS BETWEEN 12Z AND 14Z. WINDS BEHIND THE FRONT WILL INCREASE FROM
THE NORTH AT 25 TO 35 KNOTS AND CONTINUE INTO THE EARLY AFTERNOON HOURS
BEFORE DIMINISHING SOMEWHAT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 48 18 49 21 / 10 0 0 0
GCK 45 18 47 20 / 10 0 0 0
EHA 45 19 49 23 / 10 0 0 0
LBL 46 18 49 21 / 10 0 0 0
HYS 47 18 47 20 / 10 0 0 0
P28 53 20 49 23 / 10 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM CST /5 PM MST/ THIS EVENING FOR KSZ030-
031-043>046-061>066-074>081-084>090.
&&
$$
FN99/99/25
AREA FORECAST DISCUSSION
NWS GOODLAND KS
446 AM MST FRI JAN 27 2012
.DISCUSSION...
200 AM MST FRI JAN 27 2012
SHORT TERM...TODAY-SUNDAY NIGHT...COLD FRONT AN HOUR OR SO AWAY
FROM ENTERING THE FORECAST AREA. AS PREVIOUS SHIFTS HAVE
MENTIONED ADVISORY CRITERIA WINDS TO MOVE IN FROM WEST TO EAST
WITH SUSTAINED WINDS AROUND 30-35 MPH WITH GUSTS AROUND 50 MPH.
HIGH TEMPERATURES 35 TO 40 WEST OF THE CO/KS BORDER...LOW TO MID
40S EAST WITH WARMEST READINGS IN THE NORTON AND HILL CITY AREAS.
VERY DRY AIR MOVES IN TONIGHT AND AROUND 06Z WINDS MAY REALLY DROP
OFF FOR A FEW HOURS BEFORE INCREASING FROM THE SOUTHWEST WHICH
SHOULD TEND TO STABILIZE TEMPS A BIT. ITS THAT FEW HOURS WHERE THE
COLDEST READINGS EXPECTED WITH LOWS GENERALLY 10-15 DEGREES. DRY
AIR REMAINS OVER THE AREA SATURDAY WITH AFTERNOON HIGHS IN THE MID
40S. SHOULD HAVE NORTHWEST WINDS OF 15-20 MPH WITH HIGHER GUSTS
GENERALLY NORTH OF THE INTERSTATE AS PRESSURE GRADIENT INCREASES.
FOR SUNDAY MILD TEMPERATURES RETURN TO THE AREA AS BROAD UPPER
RIDGING SLOWLY MOVES IN FROM THE WEST. HIGH TEMPERATURES GENERALLY
IN THE MID 50S.
007
LONG TERM...MONDAY THROUGH THURSDAY
AN UPPER LEVEL TROUGH WILL MOVE THROUGH THE TRI-STATE AREA TUESDAY
AND AGAIN ON WEDNESDAY. DUE TO UNCERTAINTIES REGARDING MOISTURE AND
JET SUPPORT WILL GO WITH THE DRY CONSENSUS MODEL OUTPUT.
TEMPERATURES THROUGH THE PERIOD WILL BE ABOVE NORMAL. THE WARMEST
TEMPERATURES FOR THE PERIOD WILL BE MONDAY PRIOR TO A COLD FRONT
MOVING THROUGH THE AREA MONDAY NIGHT.
JTL
&&
.AVIATION...
436 AM MST FRI JAN 27 2012
VFR CONDITIONS EXPECTED FOR THE 12Z TAFS. COLD FRONT CURRENTLY
WORKING ITS WAY THROUGH NORTHEAST COLORADO AND SOUTHWEST NEBRASKA.
AM THINKING THE FRONT WILL MOVE THROUGH THE TAFS SITES DURING THE
12Z TO 15Z TIME FRAME THIS MORNING...MOVING THROUGH KGLD CLOSER TO
12Z AND KMCK CLOSER TO 15Z. NAM SOUNDINGS/CROSS SECTIONS AND EARLIER
HRRR HAVE BEEN INDICATING A PERIOD OF MVFR CEILINGS AS THE FRONT
MOVES THROUGH. LATEST HRRR HAS BACKED OFF THE MVFR
CEILINGS...SHOWING LOW VFR CEILINGS INSTEAD WHICH IS MORE IN LINE
WITH THE LATEST OBSERVATIONS. AS SUCH HAVE LOW VFR CEILINGS
FORECAST AS THE FRONT MOVES THROUGH. BEHIND THE FRONT WINDS WILL
INCREASE QUICKLY AND REMAIN STRONG THROUGH MUCH OF THE AFTERNOON.
THE WINDS WILL BACK OFF AS TEMPERATURES COOL DURING THE EVENING.
JTL
&&
.FIRE WEATHER...
200 AM MST FRI JAN 27 2012
CRITICAL FIRE WEATHER CONDITIONS REMAIN POSSIBLE SATURDAY
AFTERNOON. AFTERNOON RH VALUES TO DROP JUST BELOW 20 PERCENT WITH
NORTHWEST WINDS OF 15 TO 20 MPH WITH HIGHER GUSTS. LATER SHIFTS
CAN RE-EVALUATE THE NEED FOR A FIRE WEATHER HIGHLITE.
007
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WIND ADVISORY FROM 8 AM MST /9 AM CST/ THIS MORNING TO 5 PM MST
/6 PM CST/ THIS AFTERNOON FOR KSZ001>004-013>016-027>029-
041-042.
NE...WIND ADVISORY FROM 8 AM MST /9 AM CST/ THIS MORNING TO 5 PM MST
/6 PM CST/ THIS AFTERNOON FOR NEZ079>081.
CO...WIND ADVISORY FROM 8 AM THIS MORNING TO 5 PM MST THIS AFTERNOON
FOR COZ090>092.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
324 AM CST FRI JAN 27 2012
.SYNOPSIS...
IN APPLYING THE FORECAST FUNNEL, ONE WOULD START WITH THE 27.00Z 300
HPA SYNOPTIC MAP. A 100 KT JET EXTENDED FROM KMFR TO KLBF. THIS JET
WAS WELL UPSTREAM OF A HIGHLY AMPLIFIED MERIDIONAL TROUGH AXIS THAT
EXTENDED FROM ONTARIO INTO THE GULF OF MEXICO. A FASTER 135 TO 140 KT
JET LOCATED EAST OF THIS TROUGH AXIS ACROSS THE EASTERN UNITED STATES.
AT 500 HPA, A SHORTWAVE TROUGH WAS MOVING ACROSS THE NORTHERN ROCKIES.
THIS UPPER LEVEL FEATURE WAS USHERING IN A SURFACE COLD FRONT ACROSS
THE NORTHERN PLAINS AND INTO WYOMING. NOTHING TOO OUT OF THE ORDINARY WAS
OBSERVED AT 700 AND 850 HPA ACROSS THE CENTRAL PLAINS EXCEPT A DRY THERMODYNAMIC
PROFILE. -SUGDEN
&&
.DISCUSSION...
DAYS 1-2...
TODAY:
FORECAST SOUNDINGS FROM THE 27.00Z GFS AND 27.00Z NAM BOTH AGREE ON
RAPID SATURATION BETWEEN 600 AND 400 HPA IN ASSOCIATION WITH MID LEVEL
MOISTURE ADVECTION AHEAD OF AN APPROACHING UPPER LEVEL SHORTWAVE TROUGH
THIS MORNING. BELOW 600 HPA, ALL MODELS SHOW THE ATMOSPHERIC PROFILE
BECOMING MIXED (PARTICULARLY BELOW 800 HPA) AND AS A RESULT IS RELATIVELY
DRY. WITH THE EXCEPTION OF THE 27.00Z GFS, ALL MODELS BASICALLY HAVE
NO QPF ACROSS SOUTHWEST KANSAS TODAY. ALSO CHECKED THE ARW/NMM/HRRR
WHICH PAINT AN ALMOST NEGLIGIBLE QPF SIGNAL. AS A RESULT, HAVE REDUCED
POPS TO BELOW 15 PERCENT. SOME VIRGA IS POSSIBLE THIS MORNING BUT OTHER
THAN THAT, THE FORECAST WILL REMAIN DRY FOR TODAY.
SECOND SENSIBLE WEATHER CONCERN AND RATHER THE MOST SIGNIFICANT IS WINDS.
AS THE ABOVE MENTIONED SHORTWAVE TROUGH MOVES ACROSS KANSAS, THIS FEATURE
WILL PUSH A SURFACE COLD FRONT ACROSS THE REGION THIS MORNING. IN THE
WAKE OF THE FRONT, A TIGHT PRESSURE GRADIENT AND MIXING FROM ON AVERAGE
800 HPA TO THE SURFACE WILL RESULT IN MOMENTUM TRANSFER FROM THE TOP
OF THE BOUNDARY LAYER TO THE GROUND. BUFKIT SOUNDINGS SHOW ABOUT 40
KT AT THE TOP OF THE MIXING LAYER. AS WITH THE PREVIOUS DAY SHIFT, I
HAVE UTILIZED THE MIXED LAYER WIND SMART TOOL WHICH BROUGHT IT REASONABLE
WINDS SPEEDS INTO THE GRIDS. MOS/LAMP GUIDANCE ALSO SUGGESTS SIMILAR
WIND MAGNITUDE AS OUTPUTTED BY TOOL. THE ONGOING NPW LOOKS VERY REASONABLE
ALTHOUGH I DID ADJUST THE START TIME EARLIER AS THE HRRR MODEL IS SUGGESTING
NEAR CRITERIA WIND SPEEDS AT THE END OF THE MODEL RUN (EARLIER). WINDS
AROUND 29-33 KT WITH GUSTS TO 40-45 KT ARE FORECAST TODAY. WINDS WILL
DECREASE SIGNIFICANTLY TOWARDS SUNSET.
TONIGHT:
HIGH PRESSURE WILL SLIDE ACROSS KANSAS TONIGHT AND INTO TOMORROW MORNING.
FORECAST SOUNDINGS SHOW RAPID DRYING IN THE MID LEVELS AFTER 00Z. WITH
CLEARING SKIES AND RELATIVELY LIGHT WINDS, AM EXPECTING COOL OVERNIGHT
LOWS WITH TEENS TO LOW 20S DEG F ACROSS MUCH OF THE REGION. SUBSIDENCE
AND HIGH PRESSURE IN THE WAKE OF THE DEPARTING TROUGH WILL KEEP POPS
AT ZERO BY 06Z TONIGHT.
SATURDAY/SATURDAY NIGHT:
EXTREMELY QUIET WEATHER IS EXPECTED AS NORTHWESTERLY FLOW ALOFT PREVAILS
ACROSS THE SUNFLOWER STATE THROUGH THE BEGINNING OF THE WEEKEND. MUCH
WEAKER WESTERLY TO NORTHWESTERLY WINDS AROUND 10 TO 15 KT ARE EXPECTED
SATURDAY. TEMPERATURES WILL BE FAIRLY SEASONABLE TO SLIGHT ABOVE
WITH MID TO UPPER 40S DEG F EXPECTED. SKIES SHOULD BE FAIRLY
CLEAR. LOWS INTO SUNDAY MORNING ARE EXPECTED TO BE NEAR NORMAL...LOW
20S DEG F. -SUGDEN
DAYS 3-7...
A PROGRESSIVE, ZONAL SYNOPTIC SCALE PATTERN IS EXPECTED TO PREVAIL THROUGH
THE MEDIUM RANGE YIELDING WEAK COLD FRONT PASSAGES AND AN OVERALL CONTINUED
ABOVE-AVERAGE TEMPERATURE FORECAST.
A LEE TROUGH WILL DEVELOP SUNDAY AS AN UPPER LEVEL TROUGH BEGINS TO
ENTER THE PACIFIC NORTHWEST REGION. REMNANT, COOL POLAR AIRMASS OVER
THE CENTRAL CONUS WILL LOSE ITS GRIP WITH INCREASING LOW LEVEL THICKNESSES
AND SUBSEQUENT WARMER TEMPERATURES OVER THE WESTERN PLAINS. HIGHS SUNDAY
SHOULD WARM WELL INTO THE 50S AND HAVE INCREASED THE FORECAST HIGHS
ABOUT 2 TO 3 DEGREES ON AVERAGE ACROSS THE DDC FORECAST AREA.
MONDAY CERTAINLY LOOKS TO BE A WARM DAY WITH THE LEE TROUGH OVER EASTERN
COLORADO AND ADJACENT WESTERN KANSAS DOWN TO ABOUT 1002-1004MB. DEPENDING
ON THE DEGREE OF BOUNDARY LAYER MIXING, A VERY WARM DAY COULD RESULT...ESPECIALLY
ACROSS THE SOUTHWESTERN COUNTIES (HIGHER ELEVATION RESULTING IN BETTER
POTENTIAL FOR DEEPER MIXING). THE ALLBLEND GUIDANCE GIVES HIGHS OF 59-60F
FOR MUCH OF THE FORECAST AREA BUT SOME MID 60S CANNOT BE RULED OUT IN
THIS VERY WARM PATTERN AHEAD OF A LOW AMPLITUDE ZONAL SHORTWAVE TROUGH.
THIS AFOREMENTIONED TROUGH WILL MOVE FAST ACROSS THE CENTRAL PLAINS
MONDAY NIGHT AND TUESDAY SHOULD BE A BIT COOLER...YET STILL QUITE A
BIT ABOVE THE CLIMATOLOGICAL AVERAGE OF LOWER-MID 40S FOR SOUTHWEST
KANSAS TO END THE MONTH OF JANUARY. AFTER THAT...THERE IS SOME UNCERTAINTY
IN HOW THE PATTERN WILL EVOLVE. THE GFS SHOWS AMPLIFICATION TAKING PLACE
QUICKLY OVER THE WESTERN CONUS WITH A RIDGE AXIS OVER THE WEST COAST
AND SUBSEQUENT TROUGH OVER THE CENTRAL CONUS. THIS IS A COOLER PATTERN,
HOWEVER THE NEW ECMWF MODEL SHOWS A MUCH WARMER SCENARIO FOR MID-WEEK
WITH A MUCH LOWER AMPLITUDE RIDGE-TROUGH SETUP OVER THE WESTERN AND
CENTRAL CONUS. THE ECMWF MODEL DOES INDEED AMPLIFY THE SYNOPTIC SCALE
PATTERN RATHER SUBSTANTIALLY BY THURSDAY, RESULTING IN A MEAN TROUGH/LOWER
HEIGHTS OVER THE CENTRAL CONUS...SO THE ABOVE/MUCH ABOVE TEMPERATURES
WE WILL BE SEEING SUNDAY THROUGH WEDNESDAY MAY END BY THURSDAY- FRIDAY
OF NEXT WEEK (FEB 2-3) DEPENDING ON HOW THE AMPLIFICATION OF THE LARGE
SCALE PATTERN EVOLVES OVER THE CONUS. -UMSCHEID
&&
.AVIATION...
FOR THE 06Z TAF ISSUANCE...SOUTH TO SOUTHEAST WINDS AT 8 TO 15 KNOTS
WILL PERSIST AT THE TAF SITES THROUGH ABOUT 10Z. THE WINDS COULD OCCASIONALLY
BE GUSTY TO 20 KNOTS AS WELL. AFTER 10Z THE WINDS WILL DIMINISH AND
SWITCH TO THE SOUTHWEST AS A LOW PRESSURE TROUGH MOVES INTO THE AREA
FROM EASTERN COLORADO. A STRONG COLD FRONT WILL PUSH THROUGH WESTERN
KANSAS BETWEEN 12Z AND 14Z. WINDS BEHIND THE FRONT WILL INCREASE FROM
THE NORTH AT 25 TO 35 KNOTS AND CONTINUE INTO THE EARLY AFTERNOON HOURS
BEFORE DIMINISHING SOMEWHAT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 48 18 49 21 / 10 0 0 0
GCK 45 18 47 20 / 10 0 0 0
EHA 45 19 49 23 / 10 0 0 0
LBL 46 18 49 21 / 10 0 0 0
HYS 47 18 47 20 / 10 0 0 0
P28 53 20 49 23 / 10 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 8 AM CST /7 AM MST/ THIS MORNING TO 6 PM CST
/5 PM MST/ THIS EVENING FOR KSZ030-031-043>046-061>066-074>081-
084>090.
&&
$$
FN36/25/25
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
1140 AM EST FRI JAN 27 2012
.SYNOPSIS...
LOW PRESSURE WILL APPROACH FROM THE WEST PROMPTING A SECONDARY
COASTAL LOW TO DEEPEN ALONG THE NEW ENGLAND COAST THIS
AFTERNOON. THE LOW WILL EXIT INTO THE CANADIAN MARITIMES TONIGHT.
ANOTHER LOW WILL TRACK THROUGH SOUTHERN CANADA SATURDAY NIGHT
WITH A WEAK COLD FRONT CROSSING NORTHERN NEW ENGLAND. ANOTHER
FRONT WILL CROSS NEW ENGLAND SUNDAY NIGHT WITH COLDER TEMPERATURES
BEHIND IT. A WARM FRONT WILL LIFT NORTHWARD INTO NORTHERN NEW
ENGLAND TUESDAY NIGHT AND LOW PRESSURE WILL TRACK ALONG THE WARM
FRONT ON WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
.UPDATE...
JUST A QUICK UPDATE TO ADJUST TEMPERATURES AND DEW POINTS AND
EXTEND ADVISORIES ANOTHER 2-3 HOURS AS COLD AIR REMAINS STUBBORN.
THE WARNINGS IN PLACE FOR COOS...OXFORD...FRANKLIN...AND SOMERSET
WERE EXTENDED UNTIL 7 PM AS SREF PROBABILITIES INDICATE FREEZING
RAIN WILL CONTINUE TO BE LIKELY.
&&
.PREVIOUS UPDATE... FREEZING LINE CONTINUES TO CREEP NORTH INTO
CENTRAL GRAFTON AND CARROLL COUNTIES BUT REMAINS MIDWAY THROUGH
CUMBERLAND COUNTY AND SOUTH OF AUGUSTA. WINDS ARE EASTERLY ALONG
THE COAST AND ROCKLAND IS GUSTING TO NEAR 30 MPH. THE BEST
PRESSURE FALLS ARE NEAR BEVERLY MASSACHUSETTS AND IT APPEARS THIS
IS WHERE THE SURFACE LOW WILL REDEVELOP. THIS WILL KEEP THE COLD
AIR OVER OUR AREA LONGER. WILL NEED TO KEEP AN EYE ON THE ENDING
TIMES OF THE ADVISORIES AND WARNINGS. THE HRRR MODEL INDICATES
PRECIPITATION WILL BE WINDING DOWN BY NOON...BUT IF COLD AIR HANGS
ON AND LIGHT PRECIPITATION CONTINUES WE MAY NEED TO EXTEND THE
ADVISORY FOR A COUPLE HOURS. RADAR IMAGERY IS ENCOURAGING WITH A
RELATIVELY ECHO-FREE AREA HEADED OUR WAY. ADJUSTED HIGH
TEMPERATURES DOWN A COUPLE OF DEGREES FOR THIS UPDATE.
$$
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
AFTER SOME PCPN OVER EASTERN AREAS EARLY...CLEARING IS EXPECTED
THIS EVENING AS THE SURFACE LOW PROGRESSES INTO THE CANADIAN
MARITIMES. THIS WILL BE FOLLOWED BY A WEAK RIDGE OF HIGH PRESSURE
LATE TONIGHT. HOWEVER...SOME HIGH...THIN CLOUDINESS WILL ALREADY
BE INVADING THE SKY BY MIDDAY SATURDAY AS A WEAK TROUGH OF LOW
PRESSURE QUICKLY APPROACHES NORTHERN NEW ENGLAND. WITH DRY
ATMOSPHERE IN PLACE IN THE LOWER LEVELS...WE EXPECT ANY PCPN TO
HOLD OFF UNTIL AFTER DARK.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
OVER THE OUTLOOK PERIOD FAST MOVING CLIPPERS WITH VERY LIMITED
MOISTURE WILL BE MOVING THROUGH A RATHER ZONAL WESTERLY FLOW
ALLOWING EXCHANGES IN AIR MASSES ABOUT EVERY 48 HRS. TEMPS WILL
GENERALLY BE AVERAGING ABOVE NORMAL THROUGH MOST OF THE PERIOD.
WITH THAT GENERAL OUTLOOK IN MIND...MORE SPECIFICALLY...A RIDGE OF
HIGH PRESSURE CROSSES THE AREA ON SATURDAY WITH WARMER
TEMPERATURES AND DRY CONDITIONS.
A FAST MOVING CLIPPER MOVES EAST THROUGH ONTARIO AND INTO QUEBEC
LATE SATURDAY INTO SATURDAY NIGHT...SPREADING SCATTERED SNOW
SHOWERS ACROSS THE MOUNTAINS OF NEW HAMPSHIRE AND WESTERN MAINE. A
COLD FRONT WILL PUSH THROUGH AS WELL WITH COLDER TEMPERATURES AND
GUSTY WEST WINDS BEHIND IT.
A WEAK RIDGE OF PRESSURE SETTLES OVER THE AREA SUNDAY BUT IS
QUICKLY FOLLOWED BY ANOTHER FAST MOVING CLIPPER THAT WILL MOVE
ACROSS NEW ENGLAND SUNDAY NIGHT WITH A WEAK SURFACE LOW TRACKING
THROUGH SOUTHERN QUEBEC. A FEW MORE LIGHT SNOW SHOWERS WILL BE
POSSIBLE MAINLY IN THE MOUNTAINS. SEASONABLY COLD AIR WILL MOVE IN
FOR MONDAY.
THE FAST FLOW ALOFT CONTINUES THROUGH THE WEEK WITH WAVE AFTER
WAVE CROSSING THROUGH THE FLOW. ANOTHER WAVE APPROACHES ON TUESDAY
WITH A WARM FRONT LIFTING NORTHWARD INTO CENTRAL PARTS OF NEW
HAMPSHIRE AND MAINE BY TUESDAY NIGHT INTO WEDNESDAY. THIS MAY LEAD
TO SOME LIGHT SNOW BUT OVERALL FORCING LOOKS WEAK UNTIL WEDNESDAY
WHEN SURFACE LOW PRESSURE TRACKS EASTWARD ALONG THE WARM FRONT.
BEST PRECIPITATION CHANCES WILL BE FARTHER TO THE NORTH. WARM AIR
IN PLACE SOUTH OF THE WARM FRONT WILL YIELD MOSTLY RAIN AS
PRECIPITATION TYPE...WHILE NORTH OF THE FRONT SNOW IS MORE
LIKELY.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
SHORT TERM...
MAINLY LIFR CONDITIONS...IMPROVING TO VFR THIS EVENING WITH THE
PASSAGE OF THE SURFACE LOW AND A WIND SWITCH TO THE WEST.
LONG TERM...
MOSTLY VFR CONDITIONS EXPECTED. MOST LIKELY TIMES FOR
FLIGHT RESTRICTIONS WILL BE SUNDAY NIGHT AND AGAIN TUESDAY THROUGH
WEDNESDAY.
&&
.MARINE...
SHORT TERM...
HAVE ISSUED A GALE WARNING FOR THE OUTER WATERS THROUGH TONIGHT AS
SURFACE LOW INTENSIFIES...PULLS TO OUR EAST...AND INCREASES THE
GRADIENT AS WELL AS THE COLD AIR ADVECTION.
LONG TERM...
MAY SEE WINDS REACH 30 OR 35 KT BEHIND A COLD FRONT ON
SATURDAY NIGHT. ANOTHER FAST MOVING FRONT WILL CROSS THE WATERS
SUNDAY NIGHT WITH GUSTY WINDS BEHIND IT AS WELL.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
MEZ019>022.
WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
MEZ007>009.
WINTER WEATHER ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
MEZ012>014.
NH...WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
NHZ005-006.
WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
NHZ001>004.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST SATURDAY FOR ANZ151-153.
GALE WARNING UNTIL 5 AM EST SATURDAY FOR ANZ150-152-154.
&&
$$
UPDATE...HANES
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
1041 AM EST FRI JAN 27 2012
.SYNOPSIS...
LOW PRESSURE WILL APPROACH FROM THE WEST PROMPTING A SECONDARY
COASTAL LOW TO DEEPEN ALONG THE NEW ENGLAND COAST THIS
AFTERNOON. THE LOW WILL EXIT INTO THE CANADIAN MARITIMES TONIGHT.
ANOTHER LOW WILL TRACK THROUGH SOUTHERN CANADA SATURDAY NIGHT
WITH A WEAK COLD FRONT CROSSING NORTHERN NEW ENGLAND. ANOTHER
FRONT WILL CROSS NEW ENGLAND SUNDAY NIGHT WITH COLDER TEMPERATURES
BEHIND IT. A WARM FRONT WILL LIFT NORTHWARD INTO NORTHERN NEW
ENGLAND TUESDAY NIGHT AND LOW PRESSURE WILL TRACK ALONG THE WARM
FRONT ON WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
.UPDATE...
FREEZING LINE CONTINUES TO CREEP NORTH INTO CENTRAL GRAFTON AND
CARROLL COUNTIES BUT REMAINS MIDWAY THROUGH CUMBERLAND COUNTY AND
SOUTH OF AUGUSTA. WINDS ARE EASTERLY ALONG THE COAST AND ROCKLAND
IS GUSTING TO NEAR 30 MPH. THE BEST PRESSURE FALLS ARE NEAR
BEVERLY MASSACHUSETTS AND IT APPEARS THIS IS WHERE THE SURFACE LOW
WILL REDEVELOP. THIS WILL KEEP THE COLD AIR OVER OUR AREA LONGER.
WILL NEED TO KEEP AN EYE ON THE ENDING TIMES OF THE ADVISORIES AND
WARNINGS. THE HRRR MODEL INDICATES PRECIPITATION WILL BE WINDING
DOWN BY NOON...BUT IF COLD AIR HANGS ON AND LIGHT PRECIPITATION
CONTINUES WE MAY NEED TO EXTEND THE ADVISORY FOR A COUPLE HOURS.
RADAR IMAGERY IS ENCOURAGING WITH A RELATIVELY ECHO-FREE AREA
HEADED OUR WAY. ADJUSTED HIGH TEMPERATURES DOWN A COUPLE OF
DEGREES FOR THIS UPDATE.
$$
PREVIOUS UPDATE... HAVE UPDATED THE FORECASTS AND GRIDS TO
ACCOUNT FOR CURRENT CONDITIONS WITH THE ANTICIPATED CHANGEOVER IN
FULL SWING ACROSS SOUTHERN ZONES. HAVE REMOVED THE COAST FROM THE
WINTER WEATHER ADVISORIES AS TEMPERATURES HAVE CLIMBED TO AT OR
ABOVE FREEZING IN MOST LOCATIONS AS THE ONSHORE EASTERLIES
CONTINUE OFF THE BRINK. OVER SOUTHERN NEW HAMPSHIRE AND INTERIOR
SOUTHWEST MAINE...WARM AIR HAS SUFFICIENTLY ENTERED THE
REGION...BOTH AT THE SURFACE AND ALOFT TO CHANGE THE P TYPE TO
RAIN.
LATEST SURFACE ANALYSIS CONTINUES TO SHOW THE BEST PRESSURE FALLS
ALONG THE MASSACHUSETTS COASTLINE WHILE LOW PRESSURE LINGERS BACK
IN WRN PA. WINDS HAVE BACKED OVER THE LAST HOUR ALONG THE COAST.
THIS TREND WILL BE MONITORED VERY CLOSELY IN THE EVENT THE
SECONDARY LOW DEVELOPS FURTHER SOUTH NEAR MASSACHUSETTS...INSTEAD
OF THE MAINE COASTLINE. THIS WOULD HAVE RAMIFICATIONS TO THE LOW
LEVEL THERMAL PROFILE AND P TYPES FOR TODAY...BRINGING A SLIGHTLY
COLDER SOLUTION TO THIS EVENT OVER CENTRAL AND NORTHERN AREAS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
AFTER SOME PCPN OVER EASTERN AREAS EARLY...CLEARING IS EXPECTED
THIS EVENING AS THE SURFACE LOW PROGRESSES INTO THE CANADIAN
MARITIMES. THIS WILL BE FOLLOWED BY A WEAK RIDGE OF HIGH PRESSURE
LATE TONIGHT. HOWEVER...SOME HIGH...THIN CLOUDINESS WILL ALREADY
BE INVADING THE SKY BY MIDDAY SATURDAY AS A WEAK TROUGH OF LOW
PRESSURE QUICKLY APPROACHES NORTHERN NEW ENGLAND. WITH DRY
ATMOSPHERE IN PLACE IN THE LOWER LEVELS...WE EXPECT ANY PCPN TO
HOLD OFF UNTIL AFTER DARK.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
OVER THE OUTLOOK PERIOD FAST MOVING CLIPPERS WITH VERY LIMITED
MOISTURE WILL BE MOVING THROUGH A RATHER ZONAL WESTERLY FLOW
ALLOWING EXCHANGES IN AIR MASSES ABOUT EVERY 48 HRS. TEMPS WILL
GENERALLY BE AVERAGING ABOVE NORMAL THROUGH MOST OF THE PERIOD.
WITH THAT GENERAL OUTLOOK IN MIND...MORE SPECIFICALLY...A RIDGE OF
HIGH PRESSURE CROSSES THE AREA ON SATURDAY WITH WARMER
TEMPERATURES AND DRY CONDITIONS.
A FAST MOVING CLIPPER MOVES EAST THROUGH ONTARIO AND INTO QUEBEC
LATE SATURDAY INTO SATURDAY NIGHT...SPREADING SCATTERED SNOW
SHOWERS ACROSS THE MOUNTAINS OF NEW HAMPSHIRE AND WESTERN MAINE. A
COLD FRONT WILL PUSH THROUGH AS WELL WITH COLDER TEMPERATURES AND
GUSTY WEST WINDS BEHIND IT.
A WEAK RIDGE OF PRESSURE SETTLES OVER THE AREA SUNDAY BUT IS
QUICKLY FOLLOWED BY ANOTHER FAST MOVING CLIPPER THAT WILL MOVE
ACROSS NEW ENGLAND SUNDAY NIGHT WITH A WEAK SURFACE LOW TRACKING
THROUGH SOUTHERN QUEBEC. A FEW MORE LIGHT SNOW SHOWERS WILL BE
POSSIBLE MAINLY IN THE MOUNTAINS. SEASONABLY COLD AIR WILL MOVE IN
FOR MONDAY.
THE FAST FLOW ALOFT CONTINUES THROUGH THE WEEK WITH WAVE AFTER
WAVE CROSSING THROUGH THE FLOW. ANOTHER WAVE APPROACHES ON TUESDAY
WITH A WARM FRONT LIFTING NORTHWARD INTO CENTRAL PARTS OF NEW
HAMPSHIRE AND MAINE BY TUESDAY NIGHT INTO WEDNESDAY. THIS MAY LEAD
TO SOME LIGHT SNOW BUT OVERALL FORCING LOOKS WEAK UNTIL WEDNESDAY
WHEN SURFACE LOW PRESSURE TRACKS EASTWARD ALONG THE WARM FRONT.
BEST PRECIPITATION CHANCES WILL BE FARTHER TO THE NORTH. WARM AIR
IN PLACE SOUTH OF THE WARM FRONT WILL YIELD MOSTLY RAIN AS
PRECIPITATION TYPE...WHILE NORTH OF THE FRONT SNOW IS MORE
LIKELY.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
SHORT TERM...
MAINLY LIFR CONDITIONS...IMPROVING TO VFR THIS EVENING WITH THE
PASSAGE OF THE SURFACE LOW AND A WIND SWITCH TO THE WEST.
LONG TERM...
MOSTLY VFR CONDITIONS EXPECTED. MOST LIKELY TIMES FOR
FLIGHT RESTRICTIONS WILL BE SUNDAY NIGHT AND AGAIN TUESDAY THROUGH
WEDNESDAY.
&&
.MARINE...
SHORT TERM...
HAVE ISSUED A GALE WARNING FOR THE OUTER WATERS THROUGH TONIGHT AS
SURFACE LOW INTENSIFIES...PULLS TO OUR EAST...AND INCREASES THE
GRADIENT AS WELL AS THE COLD AIR ADVECTION.
LONG TERM...
MAY SEE WINDS REACH 30 OR 35 KT BEHIND A COLD FRONT ON
SATURDAY NIGHT. ANOTHER FAST MOVING FRONT WILL CROSS THE WATERS
SUNDAY NIGHT WITH GUSTY WINDS BEHIND IT AS WELL.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR MEZ019>022.
WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR
MEZ007>009.
WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
MEZ012>014.
NH...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR NHZ005-006.
WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR
NHZ001>004.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST SATURDAY FOR ANZ151-153.
GALE WARNING UNTIL 5 AM EST SATURDAY FOR ANZ150-152-154.
&&
$$
UPDATE...HANES
AREA FORECAST DISCUSSION
NWS GRAY ME
720 AM EST FRI JAN 27 2012
.SYNOPSIS...
LOW PRESSURE WILL APPROACH FROM THE WEST PROMPTING A SECONDARY COASTAL
LOW TO DEEPEN ALONG THE NEW ENGLAND COAST THIS AFTERNOON. THE LOW
WILL EXIT INTO THE CANADIAN MARITIMES TONIGHT. ANOTHER LOW WILL
TRACK THROUGH SOUTHERN CANADA ON SATURDAY NIGHT WITH A WEAK COLD
FRONT CROSSING NORTHERN NEW ENGLAND. ANOTHER FRONT WILL CROSS NEW
ENGLAND SUNDAY NIGHT WITH COLDER TEMPERATURES BEHIND IT. A WARM
FRONT WILL LIFT NORTHWARD INTO NORTHERN NEW ENGLAND TUESDAY NIGHT
AND LOW PRESSURE WILL TRACK ALONG THE WARM FRONT ON WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
HAVE UPDATED THE FORECASTS AND GRIDS TO ACCOUNT FOR CURRENT
CONDITIONS WITH THE ANTICIPATED CHANGEOVER IN FULL SWING ACROSS
SOUTHERN ZONES. HAVE REMOVED THE COAST FROM THE WINTER WEATHER
ADVISORIES AS TEMPERATURES HAVE CLIMBED TO AT OR ABOVE FREEZING IN
MOST LOCATIONS AS THE ONSHORE EASTERLIES CONTINUE OFF THE BRINK.
OVER SOUTHERN NEW HAMPSHIRE AND INTERIOR SOUTHWEST
MAINE...WARM AIR HAS SUFFICIENTLY ENTERED THE REGION...BOTH AT THE
SURFACE AND ALOFT TO CHANGE THE PTYPE TO RAIN.
LATEST SURFACE ANALYSIS CONTINUES TO SHOW THE BEST PRESSURE FALLS
ALONG THE MASSACHUSETTS COASTLINE WHILE LOW PRESSURE LINGERS BACK
IN WRN PA. WINDS HAVE BACKED OVER THE LAST HOUR ALONG THE COAST.
THIS TREND WILL BE MONITORED VERY CLOSELY IN THE EVENT THE
SECONDARY LOW DEVELOPS FURTHER SOUTH NEAR MASSACHUSETTS...INSTEAD
OF THE MAINE COASTLINE. THIS WOULD HAVE RAMIFICATIONS TO THE LOW
LEVEL THERMAL PROFILE AND PTYPES FOR TODAY...BRINGING A SLIGHTLY COLDER
SOLUTION TO THIS EVENT OVER CENTRAL AND NORTHERN AREAS.
PREV DISC...
00Z SOUNDING AT GYX REMAINS VERY DRY IN THE LOWER LEVELS.
THIS COOL/DRY AIR IS ENTRENCHED MORE THAN EVEN THE COLDEST GFS
SCENARIO HAS TO OFFER. THIS HAS KEPT PCPN IN THE FORM OF SNOW FOR
A LONGER PERIOD ACROSS SOUTHERN MAINE AND NEW HAMPSHIRE.
LATEST HRRR RUN PUSHES THE PCPN TO QUICKLY AND AGRESSIVELY INTO
THIS DRY AIR. HOWEVER...ATMOSPHERE WILL SATURDAY OVER THE NEXT
HOUR OR TWO OVER NORTHERN PORTIONS OF THE FORECAST AREA.
MAIN BAND OF STEADY PCPN WILL CONTINUE TO MOVE NORTHWARD OUT OF
SOUTHERN NEW HAMPSHIRE OVER THE NEXT FEW HOURS. PTYPE WILL
TRANSITION FROM ALL SNOW TO SLEET AND FREEZING RAIN OVER
SOUTHERNMOST NH AND FAR SOUTHWEST MAINE OVER THE NEXT HOUR OR TWO
AS WARM AIR ARRIVES BOTH IN THE BOUNDRY LAYER AND ALOFT. PTYPE
WILL SWITCH TO RAIN RIGHT ALONG THE COAST AFTER A QUICK INCH OR
TWO HAS FALLEN.
MADE SOME MINOR ADJUSTMENTS TO THE SNOWFALL MAP FOR THE WEB TO
SMOOTH AND MODIFY SOME OF THE DATA. ALL WARNINGS AND ADVISORIES
WILL REMAIN IN PLACE THROUGH 21Z.
TIMING OF CHANGEOVER AND STEADY PCPN APPEARS TO BE ON TRACK. MADE
ONLY MINOR ADJUSTMENTS TO THE GRIDS. MAY NEED TO ADDRESS THE
MARINE FCST WITH GALES SHORTLY.
FAVORED COOLER MAV TEMPS FOR TODAYS MAXES.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
AFTER SOME PCPN OVER EASTERN AREAS EARLY...CLEARING IS EXPECTED
THIS EVENING AS THE SURFACE LOW PROGRESSES INTO THE CANADIAN
MARITIMES. THIS WILL BE FOLLOWED BY A WEAK RIDGE OF HIGH PRESSURE
LATE TONIGHT. HOWEVER...SOME HIGH...THIN CLOUDINESS WILL ALREADY
BE INVADING THE SKY BY MIDDAY SATURDAY AS A WEAK TROUGH OF LOW
PRESSURE QUICKLY APPROACHES NORTHERN NEW ENGLAND. WITH DRY
ATMOSPHERE IN PLACE IN THE LOWER LEVELS...WE EXPECT ANY PCPN TO
HOLD OFF UNTIL AFTER DARK.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
OVER THE OUTLOOK PERIOD FAST MOVING CLIPPERS WITH VERY LIMITED
MOISTURE WILL BE MOVING THROUGH A RATHER ZONAL WESTERLY FLOW ALLOWING
EXCHANGES IN AIR MASSES ABOUT EVERY 48 HRS. TEMPS WILL GENERALLY
BE AVERAGING ABOVE NORMAL THROUGH MOST OF THE PERIOD.
WITH THAT GENERAL OUTLLOK IN MIND..MORE SPECIFICALLY...A RIDGE OF
HIGH PRESSURE CROSSES THE AREA ON SATURDAY WITH WARMER
TEMPERATURES AND DRY CONDITIONS.
A FAST MOVING CLIPPER MOVES EAST THROUGH ONTARIO AND INTO QUEBEC
LATE SATURDAY INTO SATURDAY NIGHT... SPREADING SCATTERED SNOW
SHOWERS ACROSS THE MOUNTAINS OF NEW HAMPSHIRE AND WESTERN MAINE.
A COLD FRONT WILL PUSH THROUGH AS WELL WITH COLDER TEMPERATURES
AND GUSTY WEST WINDS BEHIND IT.
A WEAK RIDGE OF PRES SETTLES OVER THE AREA SUNDAY BUT QUICKLY
FOLLOWED BY ANOTHER FAST MOVING CLIPPER THAT WILL MOVE ACROSS NEW
ENGLAND SUNDAY NIGHT WITH A WEAK SURFACE LOW TRACKING THROUGH
SOUTHERN QUEBEC. A FEW MORE LIGHT SNOW SHOWERS WILL BE POSSIBLE
MAINLY IN THE MOUNTAINS. SEASONABLY COLD AIR WILL MOVE IN FOR
MONDAY.
THE FAST FLOW ALOFT CONTINUES THROUGH THE WEEK WITH WAVE AFTER
WAVE CROSSING THROUGH THE FLOW. ANOTHER WAVE APPROACHES ON TUESDAY
WITH A WARM FRONT LIFTING NORTHWARD INTO CENTRAL PARTS OF NEW
HAMPSHIRE AND MAINE BY TUESDAY NIGHT INTO WEDNESDAY. THIS MAY LEAD
TO SOME LIGHT SNOW BUT OVERALL FORCING LOOKS WEAK UNTIL WEDNESDAY
WHEN SURFACE LOW PRESSURE TRACKS EASTWARD ALONG THE WARM FRONT.
BEST PRECIPITATION CHANCES WILL BE FURTHER TO THE NORTH. WARM AIR
IN PLACE SOUTH OF THE WARM FRONT WILL YIELD MOSTLY RAIN AS
PRECIPITATION TYPE... WHILE NORTH OF THE FRONT SNOW IS MORE
LIKELY.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
SHORT TERM...
MAINLY LIFR CONDITIONS...IMPROVING TO VFR THIS EVENING WITH THE
PASSAGE OF THE SURFACE LOW AND A WIND SWITCH TO THE WEST.
LONG TERM...
MOSTLY VFR CONDITIONS EXPECTED. MOST LIKELY TIMES FOR
FLIGHT RESTRICTIONS WILL BE SUNDAY NIGHT AND AGAIN TUESDAY THROUGH
WEDNESDAY.
&&
.MARINE...
SHORT TERM...
HAVE ISSUED A GALE WARNING FOR THE OUTER WATERS THROUGH TONIGHT AS
SURFACE LOW INTENSIFIES...PULLS TO OUR EAST...AND INCREASES THE
GRADIENT AS WELL AS THE COLD AIR ADVECTION.
LONG TERM...
MAY SEE WINDS REACH 30 OR 35 KT BEHIND A COLD FRONT ON
SATURDAY NIGHT. ANOTHER FAST MOVING FRONT WILL CROSS THE WATERS
SUNDAY NIGHT WITH GUSTY WINDS BEHIND IT AS WELL.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR MEZ019>022.
WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR
MEZ007>009.
WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
MEZ012>014.
NH...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR NHZ005-006.
WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR
NHZ001>004.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST SATURDAY FOR ANZ151-153.
GALE WARNING UNTIL 5 AM EST SATURDAY FOR ANZ150-152-154.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
512 AM EST FRI JAN 27 2012
.SYNOPSIS...
LOW PRESSURE WILL APPROACH FROM THE WEST PROMPTING A SECONDARY COASTAL
LOW TO DEEPEN ALONG THE NEW ENGLAND COAST THIS AFTERNOON. THE LOW
WILL EXIT INTO THE CANADIAN MARITIMES TONIGHT. ANOTHER LOW WILL
TRACK THROUGH SOUTHERN CANADA ON SATURDAY NIGHT WITH A WEAK COLD
FRONT CROSSING NORTHERN NEW ENGLAND. ANOTHER FRONT WILL CROSS NEW
ENGLAND SUNDAY NIGHT WITH COLDER TEMPERATURES BEHIND IT. A WARM
FRONT WILL LIFT NORTHWARD INTO NORTHERN NEW ENGLAND TUESDAY NIGHT
AND LOW PRESSURE WILL TRACK ALONG THE WARM FRONT ON WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...
HAVE UPDATED THE FORECASTS AND GRIDS TO ACCOUNT FOR CURRENT
CONDITIONS WITH THE ANTICIPATED CHANGEOVER IN FULL SWING ACROSS
SOUTHERN ZONES. HAVE REMOVED THE COAST FROM THE WINTER WEATHER
ADVISORIES AS TEMPERATURES HAVE CLIMBED TO AT OR ABOVE FREEZING IN
MOST LOCATIONS AS THE ONSHORE EASTERLIES CONTINUE OFF THE BRINK.
OVER SOUTHERN NEW HAMPSHIRE AND INTERIOR SOUTHWEST
MAINE...WARM AIR HAS SUFFICIENTLY ENTERED THE REGION...BOTH AT THE
SURFACE AND ALOFT TO CHANGE THE PTYPE TO RAIN.
LATEST SURFACE ANALYSIS CONTINUES TO SHOW THE BEST PRESSURE FALLS
ALONG THE MASSACHUSETTS COASTLINE WHILE LOW PRESSURE LINGERS BACK
IN WRN PA. WINDS HAVE BACKED OVER THE LAST HOUR ALONG THE COAST.
THIS TREND WILL BE MONITORED VERY CLOSELY IN THE EVENT THE
SECONDARY LOW DEVELOPS FURTHER SOUTH NEAR MASSACHUSETTS...INSTEAD
OF THE MAINE COASTLINE. THIS WOULD HAVE RAMIFICATIONS TO THE LOW
LEVEL THERMAL PROFILE AND PTYPES FOR TODAY...BRINGING A SLIGHTLY COLDER
SOLUTION TO THIS EVENT OVER CENTRAL AND NORTHERN AREAS.
PREV DISC...
00Z SOUNDING AT GYX REMAINS VERY DRY IN THE LOWER LEVELS.
THIS COOL/DRY AIR IS ENTRENCHED MORE THAN EVEN THE COLDEST GFS
SCENARIO HAS TO OFFER. THIS HAS KEPT PCPN IN THE FORM OF SNOW FOR
A LONGER PERIOD ACROSS SOUTHERN MAINE AND NEW HAMPSHIRE.
LATEST HRRR RUN PUSHES THE PCPN TO QUICKLY AND AGRESSIVELY INTO
THIS DRY AIR. HOWEVER...ATMOSPHERE WILL SATURDAY OVER THE NEXT
HOUR OR TWO OVER NORTHERN PORTIONS OF THE FORECAST AREA.
MAIN BAND OF STEADY PCPN WILL CONTINUE TO MOVE NORTHWARD OUT OF
SOUTHERN NEW HAMPSHIRE OVER THE NEXT FEW HOURS. PTYPE WILL
TRANSITION FROM ALL SNOW TO SLEET AND FREEZING RAIN OVER
SOUTHERNMOST NH AND FAR SOUTHWEST MAINE OVER THE NEXT HOUR OR TWO
AS WARM AIR ARRIVES BOTH IN THE BOUNDRY LAYER AND ALOFT. PTYPE
WILL SWITCH TO RAIN RIGHT ALONG THE COAST AFTER A QUICK INCH OR
TWO HAS FALLEN.
MADE SOME MINOR ADJUSTMENTS TO THE SNOWFALL MAP FOR THE WEB TO
SMOOTH AND MODIFY SOME OF THE DATA. ALL WARNINGS AND ADVISORIES
WILL REMAIN IN PLACE THROUGH 21Z.
TIMING OF CHANGEOVER AND STEADY PCPN APPEARS TO BE ON TRACK. MADE
ONLY MINOR ADJUSTMENTS TO THE GRIDS. MAY NEED TO ADDRESS THE
MARINE FCST WITH GALES SHORTLY.
FAVORED COOLER MAV TEMPS FOR TODAYS MAXES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
AFTER SOME PCPN OVER EASTERN AREAS EARLY...CLEARING IS EXPECTED
THIS EVENING AS THE SURFACE LOW PROGRESSES INTO THE CANADIAN
MARITIMES. THIS WILL BE FOLLOWED BY A WEAK RIDGE OF HIGH PRESSURE
LATE TONIGHT. HOWEVER...SOME HIGH...THIN CLOUDINESS WILL ALREADY
BE INVADING THE SKY BY MIDDAY SATURDAY AS A WEAK TROUGH OF LOW
PRESSURE QUICKLY APPROACHES NORTHERN NEW ENGLAND. WITH DRY
ATMOSPHERE IN PLACE IN THE LOWER LEVELS...WE EXPECT ANY PCPN TO
HOLD OFF UNTIL AFTER DARK.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
OVER THE OUTLOOK PERIOD FAST MOVING CLIPPERS WITH VERY LIMITED
MOISTURE WILL BE MOVING THROUGH A RATHER ZONAL WESTERLY FLOW ALLOWING
EXCHANGES IN AIR MASSES ABOUT EVERY 48 HRS. TEMPS WILL GENERALLY
BE AVERAGING ABOVE NORMAL THROUGH MOST OF THE PERIOD.
WITH THAT GENERAL OUTLLOK IN MIND..MORE SPECIFICALLY...A RIDGE OF
HIGH PRESSURE CROSSES THE AREA ON SATURDAY WITH WARMER
TEMPERATURES AND DRY CONDITIONS.
A FAST MOVING CLIPPER MOVES EAST THROUGH ONTARIO AND INTO QUEBEC
LATE SATURDAY INTO SATURDAY NIGHT... SPREADING SCATTERED SNOW
SHOWERS ACROSS THE MOUNTAINS OF NEW HAMPSHIRE AND WESTERN MAINE.
A COLD FRONT WILL PUSH THROUGH AS WELL WITH COLDER TEMPERATURES
AND GUSTY WEST WINDS BEHIND IT.
A WEAK RIDGE OF PRES SETTLES OVER THE AREA SUNDAY BUT QUICKLY
FOLLOWED BY ANOTHER FAST MOVING CLIPPER THAT WILL MOVE ACROSS NEW
ENGLAND SUNDAY NIGHT WITH A WEAK SURFACE LOW TRACKING THROUGH
SOUTHERN QUEBEC. A FEW MORE LIGHT SNOW SHOWERS WILL BE POSSIBLE
MAINLY IN THE MOUNTAINS. SEASONABLY COLD AIR WILL MOVE IN FOR
MONDAY.
THE FAST FLOW ALOFT CONTINUES THROUGH THE WEEK WITH WAVE AFTER
WAVE CROSSING THROUGH THE FLOW. ANOTHER WAVE APPROACHES ON TUESDAY
WITH A WARM FRONT LIFTING NORTHWARD INTO CENTRAL PARTS OF NEW
HAMPSHIRE AND MAINE BY TUESDAY NIGHT INTO WEDNESDAY. THIS MAY LEAD
TO SOME LIGHT SNOW BUT OVERALL FORCING LOOKS WEAK UNTIL WEDNESDAY
WHEN SURFACE LOW PRESSURE TRACKS EASTWARD ALONG THE WARM FRONT.
BEST PRECIPITATION CHANCES WILL BE FURTHER TO THE NORTH. WARM AIR
IN PLACE SOUTH OF THE WARM FRONT WILL YIELD MOSTLY RAIN AS
PRECIPITATION TYPE... WHILE NORTH OF THE FRONT SNOW IS MORE
LIKELY.
&&
.AVIATION /10Z FRIDAY THROUGH TUESDAY/...
SHORT TERM...
MAINLY LIFR CONDITIONS...IMPROVING TO VFR THIS EVENING WITH THE
PASSAGE OF THE SURFACE LOW AND A WIND SWITCH TO THE WEST.
LONG TERM...
MOSTLY VFR CONDITIONS EXPECTED. MOST LIKELY TIMES FOR
FLIGHT RESTRICTIONS WILL BE SUNDAY NIGHT AND AGAIN TUESDAY THROUGH
WEDNESDAY.
&&
.MARINE...
SHORT TERM...
HAVE ISSUED A GALE WARNING FOR THE OUTER WATERS THROUGH TONIGHT AS
SURFACE LOW INTENSIFIES...PULLS TO OUR EAST...AND INCREASES THE
GRADIENT AS WELL AS THE COLD AIR ADVECTION.
LONG TERM...
MAY SEE WINDS REACH 30 OR 35 KT BEHIND A COLD FRONT ON
SATURDAY NIGHT. ANOTHER FAST MOVING FRONT WILL CROSS THE WATERS
SUNDAY NIGHT WITH GUSTY WINDS BEHIND IT AS WELL.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR MEZ019>022.
WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR
MEZ007>009.
WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
MEZ012>014.
NH...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR NHZ005-006.
WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR
NHZ001>004.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST SATURDAY FOR ANZ151-153.
GALE WARNING UNTIL 5 AM EST SATURDAY FOR ANZ150-152-154.
&&
$$
JC/RAM
AREA FORECAST DISCUSSION
NWS GRAY ME
139 AM EST FRI JAN 27 2012
.SYNOPSIS...
LOW PRESSURE WILL APPROACH FROM THE WEST PROMPTING A COASTAL LOW
TO DEEPEN ALONG THE NEW ENGLAND COAST THIS AFTERNOON. THE LOW
WILL EXIT INTO THE CANADIAN MARITIMES TONIGHT. ANOTHER LOW
WILL TRACK THROUGH SOUTHERN CANADA ON SATURDAY NIGHT WITH A WEAK
COLD FRONT CROSSING NORTHERN NEW ENGLAND. ANOTHER FRONT WILL CROSS
NEW ENGLAND SUNDAY NIGHT WITH COLDER TEMPERATURES BEHIND IT. A
WARM FRONT WILL LIFT NORTHWARD INTO NORTHERN NEW ENGLAND TUESDAY
NIGHT AND LOW PRESSURE WILL TRACK ALONG THE WARM FRONT ON
WEDNESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
00Z SOUNDING AT GYX REMAINS VERY DRY IN THE LOWER LEVELS. THIS
COOL/DRY AIR IS ENTRENCHED MORE THAN EVEN THE COLDEST GFS SCENARIO
HAS TO OFFER. THIS HAS KEPT PCPN IN THE FORM OF SNOW FOR A LONGER
PERIOD ACROSS SOUTHERN MAINE AND NEW HAMPSHIRE.
LATEST HRRR RUN PUSHES THE PCPN TO QUICKLY AND AGRESSIVELY INTO
THIS DRY AIR. HOWEVER...ATMOSPHERE WILL SATURDAY OVER THE NEXT
HOUR OR TWO OVER NORTHERN PORTIONS OF THE FORECAST AREA.
MAIN BAND OF STEADY PCPN WILL CONTINUE TO MOVE NORTHWARD OUT OF
SOUTHERN NEW HAMPSHIRE OVER THE NEXT FEW HOURS. PTYPE WILL
TRANSITION FROM ALL SNOW TO SLEET AND FREEZING RAIN OVER
SOUTHERNMOST NH AND FAR SOUTHWEST MAINE OVER THE NEXT HOUR OR TWO
AS WARM AIR ARRIVES BOTH IN THE BOUNDRY LAYER AND ALOFT. PTYPE
WILL SWITCH TO RAIN RIGHT ALONG THE COAST AFTER A QUICK INCH OR
TWO HAS FALLEN.
MADE SOME MINOR ADJUSTMENTS TO THE SNOWFALL MAP FOR THE WEB TO
SMOOTH AND MODIFY SOME OF THE DATA. ALL WARNINGS AND ADVISORIES
WILL REMAIN IN PLACE THROUGH 21Z.
TIMING OF CHANGEOVER AND STEADY PCPN APPEARS TO BE ON TRACK. MADE
ONLY MINOR ADJUSTMENTS TO THE GRIDS. MAY NEED TO ADDRESS THE
MARINE FCST WITH GALES SHORTLY.
FAVORED COOLER MAV TEMPS FOR TODAYS MAXES.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM SATURDAY/...
AFTER SOME PCPN OVER EASTERN AREAS EARLY...CLEARING IS EXPECTED
THIS EVENING AS THE SURFACE LOW PROGRESSES INTO THE CANADIAN
MARITIMES. THIS WILL BE FOLLOWED BY A WEAK RIDGE OF HIGH PRESSURE
LATE TONIGHT. HOWEVER...SOME HIGH...THIN CLOUDINESS WILL ALREADY
BE INVADING THE SKY BY MIDDAY SATURDAY AS A WEAK TROUGH OF LOW
PRESSURE QUICKLY APPROACHES NORTHERN NEW ENGLAND. WITH DRY
ATMOSPHERE IN PLACE IN THE LOWER LEVELS...WE EXPECT ANY PCPN TO
HOLD OFF UNTIL AFTER DARK.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
OVER THE OUTLOOK PERIOD FAST MOVING CLIPPERS WITH VERY LIMITED
MOISTURE WILL BE MOVING THROUGH A RATHER ZONAL WESTERLY FLOW ALLOWING
EXCHANGES IN AIR MASSES ABOUT EVERY 48 HRS. TEMPS WILL GENERALLY
BE AVERAGING ABOVE NORMAL THROUGH MOST OF THE PERIOD.
WITH THAT GENERAL OUTLLOK IN MIND..MORE SPECIFICALLY...A RIDGE OF
HIGH PRESSURE CROSSES THE AREA ON SATURDAY WITH WARMER
TEMPERATURES AND DRY CONDITIONS.
A FAST MOVING CLIPPER MOVES EAST THROUGH ONTARIO AND INTO QUEBEC
LATE SATURDAY INTO SATURDAY NIGHT... SPREADING SCATTERED SNOW
SHOWERS ACROSS THE MOUNTAINS OF NEW HAMPSHIRE AND WESTERN MAINE.
A COLD FRONT WILL PUSH THROUGH AS WELL WITH COLDER TEMPERATURES
AND GUSTY WEST WINDS BEHIND IT.
A WEAK RIDGE OF PRES SETTLES OVER THE AREA SUNDAY BUT QUICKLY
FOLLOWED BY ANOTHER FAST MOVING CLIPPER THAT WILL MOVE ACROSS NEW
ENGLAND SUNDAY NIGHT WITH A WEAK SURFACE LOW TRACKING THROUGH
SOUTHERN QUEBEC. A FEW MORE LIGHT SNOW SHOWERS WILL BE POSSIBLE
MAINLY IN THE MOUNTAINS. SEASONABLY COLD AIR WILL MOVE IN FOR
MONDAY.
THE FAST FLOW ALOFT CONTINUES THROUGH THE WEEK WITH WAVE AFTER
WAVE CROSSING THROUGH THE FLOW. ANOTHER WAVE APPROACHES ON TUESDAY
WITH A WARM FRONT LIFTING NORTHWARD INTO CENTRAL PARTS OF NEW
HAMPSHIRE AND MAINE BY TUESDAY NIGHT INTO WEDNESDAY. THIS MAY LEAD
TO SOME LIGHT SNOW BUT OVERALL FORCING LOOKS WEAK UNTIL WEDNESDAY
WHEN SURFACE LOW PRESSURE TRACKS EASTWARD ALONG THE WARM FRONT.
BEST PRECIPITATION CHANCES WILL BE FURTHER TO THE NORTH. WARM AIR
IN PLACE SOUTH OF THE WARM FRONT WILL YIELD MOSTLY RAIN AS
PRECIPITATION TYPE... WHILE NORTH OF THE FRONT SNOW IS MORE
LIKELY.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
SHORT TERM...
MAINLY LIFR CONDITIONS...IMPROVING TO VFR THIS EVENING WITH THE
PASSAGE OF THE SURFACE LOW AND A WIND SWITCH TO THE WEST.
LONG TERM...
MOSTLY VFR CONDITIONS EXPECTED. MOST LIKELY TIMES FOR
FLIGHT RESTRICTIONS WILL BE SUNDAY NIGHT AND AGAIN TUESDAY THROUGH
WEDNESDAY.
&&
.MARINE...
SHORT TERM...
WILL LIKELY REQUIRE A GALE WARNING FOR THE OUTER WATERS TONIGHT AS
SURFACE LOW INTENSIFIES...PULLS TO OUR EAST...AND INCREASES THE
GRADIENT AS WELL AS THE COLD AIR ADVECTION.
LONG TERM...
MAY SEE WINDS REACH 30 OR 35 KT BEHIND A COLD FRONT ON
SATURDAY NIGHT. ANOTHER FAST MOVING FRONT WILL CROSS THE WATERS
SUNDAY NIGHT WITH GUSTY WINDS BEHIND IT AS WELL.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
MEZ012>014-018>022-026>028.
WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR
MEZ007>009.
NH...WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
NHZ005>010-013.
WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR
NHZ001>004.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR
ANZ150>154.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1005 PM EST SAT JAN 28 2012
.SYNOPSIS...
CLEAR SKIES ARE EXPECTED OVERNIGHT AS DRY AIR MOVES ACROSS THE
UPPER OHIO VALLEY. A FAST MOVING COLD FRONT WILL BRING A MIX OF
RAIN AND SNOW SHOWERS TO THE AREA ON SUNDAY. HIGH PRESSURE PASSING
TO THE SOUTH WILL THEN ALLOW FOR A DRY START TO THE WORK WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
03Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO ACCOUNT
FOR MOST RECENT TEMP AND DEW POINT TRENDS AND TO INCREASE THE WINDS
FOR LATE SUNDAY MORNING INTO THE EVENING HOURS.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES THE UPPER OHIO VALLEY
IN A SOUTHWESTERLY FLOW AS A SHORT WAVE TROUGH AXIS SHIFTS
NORTHEAST OF THE AREA. AT THE SURFACE, MSAS ANALYSIS INDICATES A
998MB LOW ACROSS SOUTHERN QUEBEC. A TIGHTENED PRESSURE GRADIENT IS
SETUP ACROSS THE UPPER OHIO VALLEY BETWEEN THE LOW AND A 1030MB
HIGH ACROSS THE ARKLATEX REGION. THIS HAS LED TO WINDS GUSTING TO
30 TO 40 MPH AT TIMES EARLIER THIS EVENING.
TONIGHT...THE SURFACE LOW NORTH OF THE AREA WILL SHIFT FURTHER
NORTHEAST OF THE AREA AND THE PRESSURE GRADIENT WILL LOOSEN
SLIGHTLY. THIS IN COMBINATION WITH THE LOSS OF DIURNAL MIXING
WILL ALLOW FOR WIND GUSTS TO DECREASE OVERNIGHT. A FEW GUSTS TO 25
MPH ARE STILL NOT OUT OF THE QUESTION THOUGH. SKIES WILL BE CLEAR
ACROSS MOST OF THE AREA THROUGH THE NIGHT AS A DEEP LAYER OF DRY
AIR BUILDS INTO THE REGION. DESPITE TDS IN THE LOWER TO MID TEENS,
SOUTHWEST WINDS WILL SERVE AS A LIMITING FACTOR FOR RADIATIONAL
COOLING OVERNIGHT. OVERNIGHT LOWS ARE CLOSEST LAMP GUIDANCE,
RANGING FROM NEAR 20 ACROSS THE EASTERN RIDGES TO THE MID 20S
ELSEWHERE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
PER RECENT NAM MODEL OUTPUT, EXPECT CLIPPER-TYPE LOW PRESSURE
MOVING QUICKLY THROUGH THE GREAT LAKES TO PUSH A COLD FRONT
THROUGH THE UPPER OHIO VALLEY SUNDAY MIDDAY AND AFTERNOON. GFS/NAM
MOMENTUM TRANSFER INDICATES THAT WINDS WILL GUST TO 25 TO 35 KTS
BETWEEN 15Z AND 00Z ON SUNDAY. WITH A DEEP MIXING LAYER, A FEW
GUSTS MAY APPROACH WIND ADVISORY CRITERIA AND THIS WILL NEED TO
BE MONITORED.
EXPECT TEMPERATURES TO BE A TAD COLDER THAN SATURDAY, HENCE MORE
AREAS CAN SEE LIGHT SNOW SHOWERS. ITS POSSIBLE THERE CAN BE SHORT
BURSTS OF SLEET, BUT HAVE HELD OFF MENTION. SNOW ACCUMULATIONS
WILL AGAIN BE MINIMAL.
WITH UPPER JETSTREAM FLOW BACKING SLIGHTLY INTO THE WEST
SOUTHWEST, THE NEXT CLIPPER-TYPE SYSTEM TO PASS EASTWARD THROUGH
THE GREAT LAKES MAY HAVE LESS IMPACT ON THE UPPER OHIO VALLEY.
STILL INCLUDED A CHANCE OF SHOWERS OF RAIN AND SNOW, BUT MAINLY
NORTH.
FORECASTED HIGHS MONDAY TO BE 2-3 DEGREES WARMER THAN SUNDAY.
RECENT ECMWF MODEL OUTPUT SHOWS A DRY BREAK MONDAY NIGHT AND
TUESDAY WITH SOUTHWEST WINDS PROVIDING A WARM UP TO 10 DEGREES
ABOVE NORMAL, PER GFS AND NAEFS VALUES.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MODELS ARE IN FAIRLY GOOD AGREEMENT ON A COLD FRONT PASSAGE
WEDNESDAY AS THE ASSOCIATED LOW PRESSURE SYSTEM CROSSES NORTH OF THE
GREAT LAKES. BEYOND WEDNESDAY...THERE ARE INCONSISTENCIES FROM
RUN TO RUN WITH THE DETERMINISTIC MODELS KEEPING CONFIDENCE
RELATIVELY LOW ESPECIALLY INTO FRIDAY AND SATURDAY.
ALL MODELS SUGGEST A GRADUAL DEEPENING LONG WAVE TROUGH OVER THE
CENTRAL U.S WITH THE GFS THE STRONGEST AND THE ECMWF AND GEFS
ENSEMBLES REMAINING LESS AMPLIFIED. THIS IN TURN MAKES LOW
PLACEMENT SIGNIFICANTLY DIFFERENT BETWEEN THE MODELS. WITH SUCH A
WIDE SPREAD...OPTED TO REMAIN CLOSE TO HPC GUIDANCE FOR THE PERIOD
FROM THURSDAY THROUGH SATURDAY...WHICH IS CLOSEST TO THE 00/12Z
ECMWF AND GEFS. THIS WOULD BRING A SURFACE LOW SOUTH ALONG THE
APPALACHIANS AND OFF THE COAST BY FRIDAY.
KEPT TEMPERATURES CLOSE TO AN HPC MEX BLEND WHICH SEEMED TO MATCH UP
WELL WITH NAEFS TRENDS.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
VFR FORECAST THROUGH SUNDAY MORNING. EXPECT WINDS TO CONTINUE TO
SLOWLY WEAKEN AS THE NIGHT PROGRESSES. MOST LIKELY, WINDS WILL
REMAIN STRONGEST ACROSS THE NORTH, WHERE THE SFC PRESS GRADIENT
REMAINS TIGHT. WILL LEAVE IN GUSTS ACROSS THE NORTH.
WINDS WILL AGAIN PICK UP SUNDAY MORNING, ALTHOUGH BY THIS TIME, THEY
WILL HAVE VEERED TO THE SOUTHWEST. ANOTHER FAST-MOVING COLD FRONT
WILL BRING MVFR RESTRICTIONS SUNDAY AFTERNOON. LOWER CIGS AND A
THREE TO FOUR HOUR PERIOD OF SNOW SHOWERS IS EXPECTED.
OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...
RESTRICTIONS WILL CONTINUE SUNDAY NIGHT WITH CAA AND NW FLOW ALOFT.
VFR CONDITIONS ARE THEN ANTICIPATED MONDAY AND TUESDAY UNDER HIGH
PRESSURE. A COLD FRONT WILL BRING ANOTHER ROUND OF SHOWERS AND
POSSIBLE RESTRICTIONS ON WEDNESDAY AND THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
610 PM EST SAT JAN 28 2012
.SYNOPSIS...
CLEAR SKIES ARE EXPECTED OVERNIGHT AS DRY AIR MOVES ACROSS THE
UPPER OHIO VALLEY. A FAST MOVING COLD FRONT WILL BRING A MIX OF
RAIN AND SNOW SHOWERS TO THE AREA ON SUNDAY. HIGH PRESSURE PASSING
TO THE SOUTH WILL THEN ALLOW FOR A DRY START TO THE WORK WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AN EARLY EVENING ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN
ISSUED TO REMOVE POPS AND REDUCE CLOUD COVERAGE WITH CLEARING SKIES
OVERNIGHT.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A 500MB SHORT WAVE TROUGH
CROSSING THE EASTERN GREAT LAKES WITH THE UPPER OHIO VALLEY IN A
SOUTHWESTERLY FLOW. AT THE SURFACE, MSAS ANALYSIS INDICATES A
998MB LOW ACROSS ONTARIO. A COLD FRONT EXTENDING SOUTHEAST OF THIS
FEATURE HAS QUICKLY PUSHED EAST OF THE AREA. A TIGHTENED PRESSURE
GRADIENT ACROSS THE UPPER OHIO VALLEY BETWEEN THE LOW AND A 1030MB
HIGH ACROSS THE ARKLATEX REGION HAS LED TO WINDS GUSTING TO
35 TO 45 MPH AT TIMES THIS EVENING. SKIES HAVE CLEARED BEHIND THE
FRONT.
TONIGHT...THE SURFACE LOW NORTH OF THE AREA WILL SHIFT INTO QUEBEC
AND LOOSEN THE PRESSURE GRADIENT SLIGHTLY ACROSS THE AREA. THIS IN
COMBINATION WITH THE LOSS OF DIURNAL MIXING WILL ALLOW FOR WIND
GUSTS TO DECREASE OVERNIGHT. A FEW GUSTS TO 20 MPH ARE STILL NOT
OUT OF THE QUESTION THOUGH. SKIES WILL BE CLEAR ACROSS MOST OF
THE AREA THROUGH THE NIGHT AS A DEEP LAYER OF DRY AIR BUILDS INTO
THE REGION. DESPITE TDS IN THE MID TO UPPER TEENS, SOUTHWEST WINDS
WILL SERVE AS A LIMITING FACTOR FOR RADIATIONAL COOLING OVERNIGHT.
WITH TDS TRENDING COOLER LOWS ARE A FEW DEGREES LESS THAN LAMP
GUIDANCE, RANGING FROM THE UPPER TEENS ACROSS THE EASTERN RIDGES
TO THE MID 20S ACROSS AREAS SOUTH AND WEST OF PITTSBURGH.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
PER RECENT NAM MODEL OUTPUT, EXPECT CLIPPER-TYPE LOW PRESSURE
MOVING QUICKLY THROUGH THE GREAT LAKES TO PUSH A COLD FRONT
THROUGH THE UPPER OHIO VALLEY SUNDAY MIDDAY AND AFTERNOON.
EXPECT TEMPERATURES TO BE A TAD COLDER THAN SATURDAY, HENCE MORE
AREAS CAN SEE LIGHT SNOW SHOWERS. ITS POSSIBLE THERE CAN BE SHORT
BURSTS OF SLEET, BUT HAVE HELD OFF MENTION. SNOW ACCUMULATIONS
WILL AGAIN BE MINIMAL.
WITH UPPER JETSTREAM FLOW BACKING SLIGHTLY INTO THE WEST
SOUTHWEST, THE NEXT CLIPPER-TYPE SYSTEM TO PASS EASTWARD THROUGH
THE GREAT LAKES MAY HAVE LESS IMPACT ON THE UPPER OHIO VALLEY.
STILL INCLUDED A CHANCE OF SHOWERS OF RAIN AND SNOW, BUT MAINLY
NORTH.
FORECASTED HIGHS MONDAY TO BE 2-3 DEGREES WARMER THAN SUNDAY.
RECENT ECMWF MODEL OUTPUT SHOWS A DRY BREAK MONDAY NIGHT AND
TUESDAY WITH SOUTHWEST WINDS PROVIDING A WARM UP TO 10 DEGREES
ABOVE NORMAL, PER GFS AND NAEFS VALUES.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MODELS ARE IN FAIRLY GOOD AGREEMENT ON A COLD FRONT PASSAGE
WEDNESDAY AS THE ASSOCIATED LOW PRESSURE SYSTEM CROSSES NORTH OF THE
GREAT LAKES. BEYOND WEDNESDAY...THERE ARE INCONSISTENCIES FROM
RUN TO RUN WITH THE DETERMINISTIC MODELS KEEPING CONFIDENCE
RELATIVELY LOW ESPECIALLY INTO FRIDAY AND SATURDAY.
ALL MODELS SUGGEST A GRADUAL DEEPENING LONG WAVE TROUGH OVER THE
CENTRAL U.S WITH THE GFS THE STRONGEST AND THE ECMWF AND GEFS
ENSEMBLES REMAINING LESS AMPLIFIED. THIS IN TURN MAKES LOW
PLACEMENT SIGNIFICANTLY DIFFERENT BETWEEN THE MODELS. WITH SUCH A
WIDE SPREAD...OPTED TO REMAIN CLOSE TO HPC GUIDANCE FOR THE PERIOD
FROM THURSDAY THROUGH SATURDAY...WHICH IS CLOSEST TO THE 00/12Z
ECMWF AND GEFS. THIS WOULD BRING A SURFACE LOW SOUTH ALONG THE
APPALACHIANS AND OFF THE COAST BY FRIDAY.
KEPT TEMPERATURES CLOSE TO AN HPC MEX BLEND WHICH SEEMED TO MATCH UP
WELL WITH NAEFS TRENDS.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
VFR FORECAST THROUGH TONIGHT AND SUNDAY MORNING. GUSTY WESTERLY
WINDS WILL CONTINUE THROUGH AT LEAST THE EVENING HOURS. EXPECT WINDS
ACROSS MOST PORTS TO SLOWLY WEAKEN AFTER SUNSET. HOWEVER, SFC PRESS
GRADIENT REMAINS TIGHT OVERNIGHT, SO THERE COULD STILL BE OCCASIONAL
GUSTS. FOR THE FORECAST, WILL LEAVE IN GUSTS ACROSS THE NORTH.
WINDS WILL AGAIN PICK UP SUNDAY MORNING, ALTHOUGH BY THIS TIME, THEY
WILL HAVE VEERED TO THE SOUTHWEST. ANOTHER FAST-MOVING COLD FRONT
WILL BRING MVFR RESTRICTIONS SUNDAY AFTERNOON. LOWER CIGS AND A
THREE TO FOUR HOUR PERIOD OF SNOW SHOWERS IS EXPECTED.
OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...
RESTRICTIONS WILL CONTINUE SUNDAY NIGHT WITH CAA AND NW FLOW ALOFT.
VFR CONDITIONS ARE THEN ANTICIPATED MONDAY AND TUESDAY UNDER HIGH
PRESSURE. A COLD FRONT WILL BRING ANOTHER ROUND OF SHOWERS AND
POSSIBLE RESTRICTIONS ON WEDNESDAY AND THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
356 PM EST FRI JAN 27 2012
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES WILL CROSS THE AREA THIS
WEEKEND, BRINGING A MIX OF RAIN AND SNOW SHOWERS. HIGH PRESSURE
BUILDING IN FROM THE SOUTHWEST WILL ALLOW FOR A DRY START TO THE
WORK WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A 500MB SHORT WAVE
TROUGH AXIS EXTENDING FROM ONTARIO ACROSS THE EASTERN GREAT
LAKES. VORT ENERGY WITH THIS FEATURE HAS MOSTLY SHIFTED NORTHEAST
OF THE AREA. AT THE SURFACE, A 991MB LOW IS LOCATED IN NORTHERN NY
WITH A COLD FRONT EXTENDING SOUTHWARD OF THIS FEATURE. THE COLD
FRONT HAS PUSHED WELL EAST OF THE AREA AHEAD OF THE MID- LEVEL
TROUGH. LINGERING LIGHT RAIN AND SNOW SHOWERS ARE DIMINISHING AS
FORCING SHIFTS NORTHEAST OF THE AREA.
TONIGHT...A WEAK LOW-LEVEL RIDGE WILL BUILD INTO THE AREA WITH DRY
WEATHER EXPECTED AS HIGH PRESSURE BUILDS IN FROM THE SOUTHWEST.
THE NEXT SHORT WAVE WILL APPROACH FROM THE WEST NEAR DAWN,
RETURNING A SCHC OF SNOW SHOWERS BY DAWN ON SATURDAY FOR AREAS
NORTHWEST OF PITTSBURGH. DESPITE THE COLDER AIR MASS IN PLACE,
CLOUD COVERAGE WILL LIMIT RADIATIONAL COOLING TONIGHT, WITH LOWS A
FEW DEGREES WARMER THAN A MAV/MET BLEND, RANGING FROM THE MID 20S
ACROSS THE EASTERN RIDGES TO THE NEAR 30 ACROSS NORTH-CENTRAL WV
AND EASTERN OHIO.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
THE NAM/GFS/ECMWF SHOW AGREEMENT IN BRINGING A LOW PRESSURE SYSTEM
ACROSS THE NORTHERN GREAT LAKES THAT WILL SWEEP A WEAK COLD FRONT
ACROSS THE UPPER OHIO VALLEY ON SATURDAY. PRECIPITATION WITH THE
FRONT WILL BE GENERALLY LESS THAN A TENTH OF AN INCH WITH A LACK OF
DEEP MOISTURE WITH THIS SYSTEM. FOR PRECIP TYPE, NAM/GFS INDICATE
THE 1000-500MB 5400M LINE SOUTH OF THE AREA THROUGHOUT THE DAY,
ALTHOUGH THE 1000-850MB 1300M LINE WILL CREEP NORTH OF THE
MASON-DIXON LINE AND WILL ALLOW FOR MOSTLY RAIN SHOWERS FOR
LOCATIONS SOUTH OF THE PITTSBURGH METRO AND A MIX OF RAIN AND SNOW
NORTHWARD TO THE I-80 CORRIDOR. CHC POPS BEGIN NORTHWEST OF PITTSBURGH
DURING THE MORNING HOURS WITH POPS INCREASING TO LIKELY AS THE FRONT
CROSSES SATURDAY AFTERNOON. THE BEST CHANCE FOR ANY SNOW
ACCUMULATION WILL BE ALONG THE I-80 CORRIDOR, WITH LESS THAN AN INCH
POSSIBLE THERE. FORECAST HIGH TEMPS ARE A FEW DEGREES COOLER THAN A
MAV/MET BLEND AS ONGOING CLOUD COVERAGE WILL BE A LIMITING FACTOR.
HIGHS WILL RANGE FROM THE MID 30S ACROSS THE I-80 CORRIDOR TO THE
LOWER 40S ACROSS NORTH-CENTRAL WV.
SATURDAY NIGHT...A BREAK IS EXPECTED IN RAIN/SNOW SHOWERS AS HIGH
PRESSURE PASSES SOUTH OF THE AREA AND A DEEP LAYER OF DRY AIR BUILDS
IN THROUGH DAWN ON SUNDAY. COLD AIR ADVECTION IN THE WAKE OF THE
FRONT WILL ALLOW LOW TEMPS TO RANGE FROM NEAR 20 ALONG THE I-80
CORRIDOR AND EASTERN RIDGES TO THE MID 20S ELSEWHERE.
SUNDAY THROUGH MONDAY...THERE IS OPERATIONAL MODEL AGREEMENT THAT A
SHORT WAVE TROUGH WILL SWING INTO THE AREA SUNDAY AFTERNOON.
DECREASING THICKNESSES WILL ALLOW FOR PRECIPITATION TO BE MOSTLY IN
THE FORM OF SNOW SHOWERS WITH THIS DISTURBANCE AS IT CROSS THE UPPER
OHIO VALLEY WITH THE POSSIBILITY OF RAIN MIXING IN DURING THE
AFTERNOON FOR AREAS SOUTH OF THE I-70 CORRIDOR. ANY LIGHT SNOW
ACCUMULATION OF AN INCH OR LESS WILL BE LIMITED TO THE I-80
CORRIDOR AND THE EASTERN RIDGES WITH THIS SYSTEM. HIGH PRESSURE
WILL BUILD BACK IN FROM THE SOUTH FOR SUNDAY NIGHT INTO MONDAY,
WITH A DRY FORECAST RETURNING TO BEGIN NEXT WEEK. TEMPERATURES
WILL BE NEAR SEASONAL NORMALS THROUGH THIS PERIOD.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
HIGH PRESSURE WILL MOVE OFF THE SOUTHEASTERN UNITED STATES COAST
TUESDAY...WITH CONDITIONS REMAINING DRY. MODELS ARE IN GOOD
AGREEMENT SHOWING LOW PRESSURE MOVING ACROSS CANADA AND BRINGING A
COLD FRONT ACROSS THE REGION...ALTHOUGH THERE IS SOME DISAGREEMENT
WITH TIMING. AVERAGE TIMING PUTS FRONTAL PASSAGE AROUND
WEDNESDAY...AND HAVE PUT HIGHEST POPS IN THE FORECAST AT THAT TIME.
12Z GFS/ECMWF ARE MORE AGGRESSIVE THAN THEIR 00Z COUNTERPARTS IN
DEVELOPING A LOW ACROSS THE SOUTHEASTERN UNITED STATES...AND MOVING
IT OFFSHORE OF NEW YORK CITY BY FRIDAY MORNING. THIS BRINGS IN POPS
FOR THE EASTERN HALF OF THE REGION THURSDAY INTO FRIDAY...WITH
SLIGHT CHANCE POPS TO THE WEST. TEMPERATURES WILL BE A FEW DEGREES
ABOVE NORMAL DURING THIS TIME PERIOD.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
AS OF MID AFTERNOON...ALL SITES ARE MVFR...EXCEPT FOR FKL AND DUJ.
EXPECT THE TWO NORTHERN SITES TO FINALLY REACH MVFR CONDITIONS BY
EVENING. DURING THE EVENING HOURS...THINK THAT MOST TERMINALS SHOULD
SCATTER OUT TO MID LEVEL CLOUDS. THE EXCEPTION AGAIN WOULD BE FKL
AND DUJ...WHERE LOW LEVEL MOISTURE WOULD REMAIN MORE ENTRENCHED AND
KEEP MVFR CEILINGS IN THE FORECAST. A COLD FRONT WILL APPROACH FROM
THE WEST SATURDAY MORNING. THINK THAT ALL SITES WILL RECEIVE SOME
LIGHT PRECIPITATION...AND HAVE INDICATED THIS AT THE END OF THE TAF
CYCLE FOR SOME SITES. MANY TERMINALS MAY REMAIN VFR WITH PRECIP.
SNOW AT FKL AND DUJ WILL LIKELY RESULT IN AT LEAST MVFR RESTRICTIONS
THERE.
OUTLOOK...SATURDAY THROUGH WEDNESDAY...
POTENTIAL FOR RESTRICTIONS SHOULD CONTINUE THRU THE WEEKEND AS A
SERIES OF UPPER DISTURBANCES GENERATE SHRA/SHSN FOR MOST TERMINALS.
VFR CONDITIONS ARE THEN ANTICIPATED MONDAY AND TUESDAY UNDER HIGH
PRESSURE. A COLD FRONT IS EXPECTED TO BRING ANOTHER ROUND OF SHOWERS
AND RESTRICTIONS ON WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED FOR 06Z TAFS
NWS MARQUETTE MI
1107 PM EST THU JAN 26 2012
.SHORT TERM...
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOWS A SHOTRWAVE OVER THE NRN
PLAINS POISED TO MOVE ACROSS THE AREA TONIGHT. RADAR RETURNS SHOW A
NARROW BAND OF PCPN IN FORM OF LIGHT SNOW ASSOC WITH THIS FEATURE
OVER WRN LAKE SUPERIOR AND NW WI. ANOTHER SHORTWAVE NOW OVER THE NRN
ROCKIES IS PROGGED TO MOVE INTO THE UPR MS VALLEY AND WRN GREAT
LAKES LATE FRIDAY BRINGING ANOTHER CHC FOR LIGHT SNOW FRI AFTERNOON
AND FRI NIGHT.
800-700 MB FGEN AND MODERATE MID-LVL Q-VECT CONV ALONG FRONTAL
BOUNDARY HAS RESULTED IN BAND OF LIGHT SNOW OVER WRN LAKE SUPERIOR
AND NW WI. MODELS INDICATE FGEN FORCING AND Q-VECT CONV WILL WEAKEN
SOME ALONG THE FRONTAL PASSAGE BUT THEN STRENGTH A BIT OVER THE ERN
FCST LATER THIS EVENING AND OVERNIGHT. THUS...KEPT ONLY SLIGHT CHC
POPS FOR SNOW OVER THE WRN HALF OF THE FCST AREA THIS EVENING AND
KEPT IN 30 PCT POPS OVER THE ERN COUNTIES. CLEARING LATER THIS
EVENING AND OVERNIGHT WILL ALLOW TEMPS TO FALL INTO THE TEENS OVER
THE WRN INTERIOR WHERE TEMPS ELSEWHERE SHOULD BE MAINLY IN THE LOWER
TO MID 20S. 850 MB TEMPS BEHIND THE FRONT ARE ONLY EXPECTED TO DROP
TO -8 TO -9C WHICH SHOULD NOT BE COLD ENOUGH FOR ANY LES IN WNW FLOW
BEHIND FRONT.
RDGG MOVING OVER THE AREA WILL KEEP MUCH OF THE CWA DRY ON FRIDAY.
THE ONLY EXCEPTION WILL BE FAR WRN COUNTIES FRI AFTERNOON WHERE
SHORTWAVE APPROACHING FM THE NRN ROCKIES WILL BRING ANOTHER CHC OF
SNOW LATE IN THE DAY.
.LONG TERM DISCUSSION /FRIDAY NIGHT THROUGH THURSDAY/...
FRIDAY NIGHT THROUGH SUNDAY...
LARGE SHORTWAVE OVER JAMES BAY WILL KEEP TROUGH ACROSS THE UPPER
GREAT LAKES THROUGH SUNDAY...WITH SEVERAL WEAK AND FAST MOVING
SHORTWAVES DEVELOPING ALONG THE DESCENDING BRANCH OF THE TROUGH OVER
THE FORECAST PERIOD. THE FIRST OF THESE SHORTWAVES WILL REACH THE
CWA SATURDAY MORNING...MERGING WITH A SECONDARY SHORTWAVE TO OUR
SOUTH...WITH THE ASSOCIATED SURFACE LOW PRESSURE SYSTEM AND PRECIP
IMPACTING THE AREA BEGINNING FRIDAY NIGHT CONTINUING DURING THE DAY
ON SATURDAY. ALL MODELS ARE PERSISTENT ON THIS IDEA...HOWEVER THERE
SEEMS TO BE SOME DISAGREEMENT BETWEEN THE NAM AND OTHER MODELS AS
FAR AS THE PLACEMENT OF THE SURFACE LOW...AND RESULTING PRECIP.
BASED ON SREF DATA ALSO TRENDING AWAY FROM GENERAL NAM
SOLUTION...HAVE DECIDED TO GO WITH CONSENSUS OF OTHER MODELS WHICH
WILL KEEP SURFACE LOW AND MAIN QVECTOR CONV TO THE SOUTH...KEEPING
MAIN PRECIP ALONG THE SOUTHERN HALF OF THE CWA...WITH SOME CHANCES
POSSIBLE ACROSS THE REMAINING CWA.
AS SYSTEM PULLS OUT SATURDAY AFTERNOON...WINDS WILL TRANSITION TO A
WNW DIRECTION AND THEN EVENTUALLY TO A MORE W DIRECTION BY SATURDAY
NIGHT...BEFORE FINALLY VEERING BACK TO THE NW BY SUNDAY MORNING
AHEAD OF NEXT APPROACHING SHORTWAVE. FALLING H850 TEMPS TO AROUND
-14C BEHIND THE ASSOCIATED COLD FRONT AND AHEAD OF A DESCENDING
POLAR JET WILL INDUCE LAKE EFFECT SNOW IN WNW FAVORED REGIONS DURING
THE DAY SATURDAY...AND THEN INTENSIFY IN AREAS FAVORED BY A NW WIND
DIRECTION DURING THE DAY SUNDAY AS H850 TEMPS BOTTOM OUT TO AROUND
-18C. POTENTIAL FOR HEAVY ACCUMULATIONS IN AFFECTED AREAS IS
POSSIBLE THROUGH THIS PERIOD/SATURDAY AFTERNOON THROUGH SUNDAY
EVENING...AS INVERSION HEIGHTS RANGE BETWEEN 5K-10K FT WITH DEEP
MOISTURE AVAILABLE AT TIMES IN THE SNOW GROWTH ZONE.
SUNDAY NIGHT THROUGH THURSDAY...
STRONG RIDGE AMPLIFICATION OVER THE WESTERN U.S. WILL ALLOW LARGE
SHORTWAVE TO REMAIN STATIONARY ACROSS HUDSON BAY...WITH A RESULTING
TROUGHING PATTERN ACROSS THE GREAT LAKES REGION. THIS SHARP TROUGH
WILL ALLOW THE POLAR JET TO DIP DOWN AS FAR SOUTH AS KENTUCKY SUNDAY
NIGHT...WHICH WILL TRANSLATE TO THE RETURN OF MUCH COLDER
TEMPERATURES TO THE REGION. H850 TEMPS OF -18C OVER THE LAKE WILL
KEEP SOME LINGERING CHANCES OF LES IN AREAS FAVORED BY NW
WINDS...QUICKLY DIMINISHING AS WAA ADVECTION COMES IN TO PLAY AND
WINDS BACK TO A MORE SW DIRECTION. AT THIS POINT/SUNDAY NIGHT/ THE
POLAR JET WILL MERGE WITH THE SUBTROPICAL JET AND MOVE
EASTWARD...WHICH WILL SLOWLY LIFT THE STATIONARY TROUGH TO THE
NORTHEAST AND RETURN MUCH OF THE US TO A MORE ZONAL FLOW BY MONDAY
NIGHT. WEAK SURFACE DISTURBANCE WILL FORM ALONG THE DESCENDING
BRANCH OF THIS SHORTWAVE...BRINGING A CHANCE FOR SYNOPTIC SNOWFALL
MONDAY...BEFORE QUICKLY MOVING OFF TO THE EAST FOLLOWING THE GENERAL
UPR LEVEL FLOW. SOME MODEL DISAGREEMENTS ON TIMING AND STRENGTH OF
THIS SHORTWAVE...WITH GFS BEING MORE PROGRESSIVE AND ECMWF BEING
SLOWER YET STRONGER...SO HAVE GONE WITH A GENERAL CONSENSUS.
THE NEXT SHORTWAVE WILL TRACK ACROSS THE AREA SOMETIME
TUESDAY/TUESDAY NIGHT NIGHT...WITH SAME DISAGREEMENT AND LOW
CONFIDENCE BETWEEN THE MODELS ON THE EXACT LOCATION AND STRENGTH.
ECMWF AND GEM ARE MORE PROGRESSIVE WITH THE ARRIVAL OF THE
SHORTWAVE...HAVING IT AMPLIFYING IT OVER THE GREAT LAKES REGION BY
TUESDAY MORNING...GFS ON THE OTHER HAND KEEPS THE LOW FARTHER TO OUR
SOUTH...PASSING ACROSS LAKE MI BY LATE TUESDAY NIGHT. DESPITE
DISAGREEMENTS ON PLACEMENT...STRONG MOISTURE AVAILABILITY/PWAT
VALUES 200 PCT ABOVE NORMAL/ AND WAA WILL BE ENOUGH TO KEEP CHANCES
OF PRECIP IN BOTH TUESDAY AND WEDNESDAY...ESPECIALLY EAST HALF OF
THE CWA. THIS AMPLIFIED TROUGH WILL ONCE AGAIN BRING SOME COLDER
TEMPERATURES IN DURING THE OVERNIGHT HOURS TUESDAY NIGHT. UPPER
GREAT LAKES SHOULD THEN TRANSITION TO A RIDGING PATTERN WITH
RELATIVELY QUIET WEATHER THROUGH THE REMAINDER OF THE FORECAST
PERIOD.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
EXPECT MVFR CIGS TO CLEAR OVERNIGHT AT KIWD AND KCMX WITH SOME IFR
CIGS BRIEFLY AT KSAW. A COLD FRONT WILL CONTINUE MOVING THROUGH
OVERNIGHT AND ASSOCIATED MIXING AND DRIER AIR SHOULD ALLOW MVFR CIGS
TO LIFT AND VFR CONDITIONS TO PREVAIL OVERNIGHT THROUGH FRI
AFTERNOON AT ALL SITES. ANOTHER COLD FRONT MOVES THROUGH FRI EVENING
WITH COLDER AIR COMING IN AND CAUSING MVFR CIGS AND VIS AT ALL SITES
WITH SOME LIGHT SNOW.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
EXPECT GUSTY SW WINDS TO 25 KTS INTO EARLY THIS EVENING AHEAD OF
APPROACHING TROUGH. AFTER THE TROUGH PASSES...W/WNW WINDS WILL
INCREASE TO 30 KTS...MAINLY OVER CENTRAL AND EASTERN LAKE SUPERIOR
THIS EVENING INTO FRI MORNING. THERE COULD BE A FEW GALE FORCE GUSTS
TO 35 KTS BUT PREVAILING WIND SPD SHOULD STAY BLO GALES. A SERIES OF
TROUGHS WILL THEN PASS THROUGH FRIDAY NIGHT THROUGH SUNDAY BEFORE
HIGH PRESSURE MOVES OVERHEAD SUN NIGHT AND MONDAY. EACH OF THESE
TROUGHS WILL BRING INCREASED WINDS...WITH A POSSIBLE PERIOD OF GALES
SAT AFTERNOON INTO SAT EVENING...MAINLY OVER THE ERN HALF OF THE
LAKE WHERE A GALE WATCH HAS BEEN ISSUED.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING FOR
LSZ265>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JMW
AVIATION...07
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
100 PM CST FRI JAN 27 2012
.AVIATION... /18Z TAF ISSUANCE/
COLD FRONT STRETCHING FROM KINL TO KAXN TO KMML. FRONTAL
BOUNDARY EXPECTED TO MOVE THROUGH MN TAF SITES BY 00Z AND THROUGH
ALL WI AIRPORTS BY 03Z. INTENSE BAND OF SNOW PRODUCING VSBYS DOWN
TO 1/4SM OVER MUCH OF FAR EAST CENTRAL MN. IFR CIGS AND VSBYS SHOULD
BE EXPECTED AS THIS BAND PASSES YOUR LOCATION. ALL SNOW PER GFS40
290K ISENTROPIC ANAL WILL END THIS REGION BY 22Z...AND OVER KEAU BY
02-03Z. LOOK FOR SURFACE PRESSURE GRADIENT TO CONTINUE TO STRENGTHEN
OVER REGION INTO LATE THIS AFTERNOON...AND REMAIN VIRTUALLY UNCHANGED
INTO 28/18Z. GUSTINESS ASSOCIATED WITH NW FLOW WILL DECOUPLE SHORTLY
AFTER 01Z MOST LOCALES...AND RETURN BY 15Z. CLIPPER SYSTEM WILL PRODUCE
ANOTHER ROUND OF LIGHT TO VERY LIGHT SNOWFALL OVER ENTIRE REGION ON
SATURDAY...AND MAINLY DURING THE AFTN. CONVERGENCE ALOFT PER GFS40
250MB LEVEL PRETTY MUCH GUARANTEEING MAINLY MVFR TO VFR VSBYS...WITH
MVFR CIGS ASSOCIATED WITH SNOWFALL.
KMSP...MFVR...OCCASIONAL VFR CIGS WILL END AT KMSP BY 21Z ASSOCIATED
WITH INTENSE SNOW BAND JUST AHEAD OF FRONTAL BOUNDARY. WEST TO NW
FLOW WILL ENVELOP AIRPORT SITE BY 23Z...WITH GUSTINESS DECOUPLING
AFTER 02Z. CLIPPER SYSTEM WILL PRODUCE ANOTHER ROUND OF LIGHT TO
VERY LIGHT SNOWFALL OVER ENTIRE REGION ON SATURDAY...AND MAINLY
DURING THE AFTN. CONVERGENCE ALOFT PER GFS40 250MB LEVEL PRETTY MUCH
GUARANTEEING MAINLY MVFR TO VFR VSBYS...WITH MVFR CIGS ASSOCIATED
WITH SNOWFALL.
&&
.DISCUSSION... /ISSUED 427 AM CST FRI JAN 27 2012/
LIGHT SNOW EVENT STILL ON COURSE FOR TODAY. SNOW IN THE DAKOTAS
IS ONGOING WITH MOST OF THE AIRPORTS UNDERNEATH THE SNOW SHOWING
BETWEEN 1-2SM VISIBILITY. THE 27.00/06Z NAM/GFS AND 27.00Z EC NOT
DEVIATING TOO FAR FROM THURSDAY`S MODEL GUIDANCE. OVER THE PAST
24-30HR...THE MODEL SOLUTIONS HAVE SHIFTED THE BEST AXIS OF QPF
NORTH WITH TIME. LIKELY A FEW MORE LOCATIONS SEEING 2-4 INCHES
ACROSS NORTHERN PORTIONS OF MINNESOTA...ESPECIALLY GIVEN THE MORE
FAVORABLE PROFILE FOR DENDRITE SNOW GROWTH. THE MODEL GUIDANCE AND
EVEN THE RADAR THIS MORNING SHOWING TWO SEPARATE AREAS OF ENHANCED
SNOW...WITH A RELATIVE WEAKNESS OVER EASTERN SD. THESE TWO AREAS
LINE UP PRETTY WELL WITH THE 700-400MB DIFFERENTIAL VORTICITY
ADVECTION...AND SEEMS TO BE BETTER 850MB TEMPERATURE ADVECTION OFF
THE RUC IN THE VICINITY OF THESE TWO AREAS AS WELL. LOWEST SNOW
TOTALS WILL LIKELY BE IN WEST CENTRAL MN WHERE THE PRECIP SHOULD
LARGELY SPLIT THE AREA AND IT MIGHT ONLY MANAGE A TRACE OF SNOW.
THE TWO AREAS SHOULD FILL IN BY THE TIME THE WAVE MAKES IT INTO
EASTERN MN AND WESTERN WI EARLY THIS AFTERNOON...SO MOST LOCATIONS
WILL AT LEAST SEE A FEW TENTHS OF SNOW. TRIED TO TIME THE POP/WX
FORECAST WITH HOURLY GRIDS THIS MORNING AND WALK A BAND OF 60-90%
POPS ACROSS THE FORECAST AREA LATE THIS MORNING AND AFTERNOON.
PROBABLY COULD BE DONE A LITTLE MORE 80-100% POPS...BUT THE SNOW
WILL BE PRETTY LIGHT. BASED THE HOURLY TREND ON A LOT OF VARIOUS
WRF-NMM AND WRF-ARW SIMULATIONS FROM NCEP/SPC/MPX. MUCH BETTER
ISENTROPIC ADIABATIC OMEGA SLIDING ACROSS THE GRAND FORKS AND
DULUTH FORECAST AREAS. BEST CHANCE FOR 1-2" WILL BE ACROSS
PORTIONS OF CENTRAL MINNESOTA...LIKELY NEAR AND NORTH OF A LINE
FROM FERGUS FALLS...TO LITTLE FALLS...TO RICE LAKE IN WI. SNOW
LARGELY MOVES OUT OF THE FORECAST THIS EVENING.
BEYOND TODAY...THERE ARE A COUPLE OTHER MINOR SNOW EVENTS IN THE
WORKS SATURDAY THROUGH WEDNESDAY. NICE 500MB SHORT WAVE DROPS
SOUTH OUT OF SASKATCHEWAN ON SATURDAY WITH SOME SURFACE RESPONSE
AND A WEAK SURFACE TROUGH. CONVERGENCE ISN`T OVERLY STRONG...BUT
PROBABLY WORTH CHANCE POPS FOR SATURDAY AFTERNOON AND EVENING.
OVERALL THE WEEKEND WILL BE COOLER AFTER TODAY`S SYSTEM...BUT LIKE
SO MANY TIMES THIS WINTER...COLD FRONTS CAN ONLY MANAGE TO COOL AS
DOWN TO NEAR NORMAL. WARM FRONT COMES THROUGH SUNDAY NIGHT...SO
ONCE AGAIN HAVE SMALL POPS IN THE FORECAST DURING THIS TIME FRAME
DUE TO THE ISENTROPIC LIFT. EC IS A LITTLE STRONGER WITH THE UPPER
TROUGH AND SURFACE LOW ON TUESDAY COMPARED TO THE GFS...BUT IT`S
ALSO FARTHER TO THE NORTH. THE SECOND HALF OF NEXT WEEK IS QUITE
WARM IF YOU TRUST THE GFS AND THE PRONOUNCED LONG WAVE RIDGING.
THE EC HOLD THE RIDGE BACK TO THE WEST.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
RAH/CLF
AREA FORECAST DISCUSSION
NWS DULUTH MN
1157 AM CST FRI JAN 27 2012
.UPDATE...HEAVIER SNOW BANDS HAVE DEVELOPED FARTHER NORTH THAN
ORIGINALLY THOUGHT. HAVE ADJUSTED POPS/QPF/SNOW AMOUNT
ACCORDINGLY. SNOW IS DIMINISHING ALREADY FROM BRD TO INL.
&&
.PREV DISCUSSION... /ISSUED 1127 AM CST FRI JAN 27 2012/
AVIATION...18Z TAF ISSUANCE...
AREA OF LOW PRESSURE WILL TRACK ACROSS THE SRN HALF OF THE
FORECAST AREA THIS AFTERNOON AND SPREAD SNOW SHOWERS THROUGH THE
REGION. SOME OF THESE SHOWERS COULD REDUCE VSBYS DOWN TO 1/2-1/4SM
AT TIMES...WITH TEMPORARY IFR CIGS AS WELL. THIS SYSTEM WILL BE
FAST MOVING...SO THESE CONDITIONS WILL BE SHORT-LIVED THIS
AFTERNOON. PREVAILING MVFR CIGS WITH POSSIBLE FLURRIES WILL
IMPROVE TO VFR THIS EVENING FOR MOST LOCATIONS...BUT CIGS DROP TO
MVFR AGAIN FOR HIB AND INL AFTER 06Z TONIGHT. DLH AND BRD COULD
SEE SOME LLWS THIS EVENING AND INTO THE OVERNIGHT HOURS...WITH
SPEED SHEAR BEING THE MAIN CONCERN AS SFC- 2000FT WINDS REMAIN
NEARLY UNIDIRECTIONAL. LIGHT LLWS WILL BE POSSIBLE AT ALL OTHER
TERMINALS THIS EVENING...HOWEVER CONFIDENCE IS LIMITED...THEREFORE
LEFT THE MENTION OUT OF 18Z TAFS. ANOTHER SURGE OF LOW LEVEL
MOISTURE MOVES IN FROM THE NW LATE TONIGHT...BUT CONFIDENCE IS LOW
REGARDING THE FORMATION OF LOW-END MVFR CIGS FOR THE SRN
TERMINALS...DLH...BRD AND HYR. SFC WINDS INCREASE FROM THE WNW
LATE SAT MORNING...WITH GUSTS 20-25 KNOTS.
PREV DISCUSSION... /ISSUED 934 AM CST FRI JAN 27 2012/
UPDATE...CURRENT RADAR TRENDS MATCH UP WELL WITH THE 11Z HRRR AND
HAVE ADJUSTED THE GRIDS THIS AFTERNOON TO LEAN TOWARDS ITS
SOLUTION. NO CHANGE FOR THE REST OF THIS MORNING.
PREV DISCUSSION... /ISSUED 546 AM CST FRI JAN 27 2012/
AVIATION...12Z TAF ISSUANCE...
A WEATHER SYSTEM WILL MOVE FROM EASTERN ND TO CENTRAL MN THIS
MORNING. EXPECT A PERIOD OF ABOUT 3 TO 5 HOURS OF IFR/MVFR CIGS AT
ALL TAF SITES...BEGINNING AT KBRD/KINL THIS MORNING...AND THEN AT
KHIB/KDLH/KHYR THIS AFTERNOON AS THE SYSTEM PASSES THROUGH
MN. THE PERIOD OF IFR/MVFR CIGS WILL BE ACCOMPANIED BY -SN AND
REDUCED VSBY. KINL SHOULD ESCAPE MOST OF THE SNOW...BUT
KBRD/KHIB/KDLH/KHYR WILL CLOSER TO THE FOCUS OF THE SNOWFALL AND
WILL SEE A PERIOD OF LOW END MVFR VSBYS. THIS WINDS TODAY WILL
GENERALLY BE LIGHT FROM THE WEST TO NORTHWEST...WITH SOME
INCREASING WESTERLY WINDS EARLY THIS EVENING. ONCE THE LOW MVFR
CIGS PASS...EACH TAF SITE SHOULD SEE HIGH BASED CIGS THROUGH
THE REST OF THE AFTERNOON AND INTO TONIGHT. WIND SHEAR MAY BE AN
ISSUE AT KBRD THIS EVENING DUE TO STRONG NORTHWEST WINDS
ALOFT...BUT OTHERWISE WIND SHEAR IS NOT EXPECTED TO BE AN ISSUE
FOR THE OTHER TAF SITES.
PREV DISCUSSION... /ISSUED 306 AM CST FRI JAN 27 2012/
SHORT TERM...THROUGH SATURDAY.
WE MADE SIGNIFICANT CHANGES TO THE FORECAST TODAY...NAMELY
SPREADING MUCH HIGHER POPS NORTH TO NEARLY THE INTERNATIONAL
BORDER.
SURFACE LOW PRESSURE OVER NORTH CENTRAL NORTH DAKOTA WILL MOVE ESE
TODAY...WITH 08Z SURFACE ANALYSIS SHOWING 2.5MB PRESSURE FALLS
JUST TO THE ESE OF THE LOW CENTER. THE GFS CONTINUES TO BE THE
FURTHEST SOUTH WITH THE TRACK OF THIS CLIPPER...AND THE RESULTANT
SNOW. THE 00Z ECMWF HAS SHIFTED THE LOW/PRECIP FURTHER NORTH...THE
NAM CONTINUES TO BE NORTH...AND THE HIGHER RESOLUTION 4KM WRF/3KM
HRRR SUGGEST SNOW WILL FALL FURTHER NORTH AS WELL. NAM ALSO SHOWS A
NICE FGEN SIGNATURE THAT MOVES THROUGH CASS/ITASCA COUNTIES...ESE
INTO WI. THERE WILL BE A NICE BURST OF SNOW THAT FALLS...AND 2 TO
3 INCHES IS EXPECTED IN THE MAIN AREA OF SNOW...WITH 1 TO 2 INCHES
NORTH AND SOUTH...AND EVEN LESS ALONG THE INTERNATIONAL BORDER. A
FEW HIGHER AMOUNTS WILL BE POSSIBLE AS WELL TO 4 INCHES. THE EXACT
LOCATION OF THE HEAVIER SNOW BAND AND THE SPEED OF THE SYSTEM
PRECLUDES US FROM ISSUING AN ADVISORY AT THIS TIME...BUT WE WILL
MONITOR RADAR OVER THE NEXT FEW HOURS AND ISSUE IF CONFIDENCE
INCREASES. AT THIS TIME...WE HAVE THE HIGHEST SNOW TOTALS ACROSS
NORTHERN CASS/SOUTHERN ITASCA COUNTIES INTO THE TWIN PORTS AND
ACROSS NORTHERN WISCONSIN.
SNOW SHOULD START THIS MORNING OVER OUR WESTERN CWA...REACH
THE EASTERN IRON RANGE...TWIN PORTS...INTERSTATE 35 CORRIDOR BY
EARLY AFTERNOON...THEN OUR EASTERN WISCONSIN ZONES BY MID-LATE
AFTERNOON.
THE SNOW WILL END IN OUR WEST THIS AFTERNOON...AND LINGER THROUGH
THE EVENING OVER PORTIONS OF NORTHWEST WISCONSIN.
COLDER AIR MOVES IN BEHIND THE LOW TONIGHT INTO SATURDAY. LOW
LEVEL FLOW IS TOO WESTERLY TO GET ANY SIGNIFICANT LES.
CYCLONIC UPPER LEVEL FLOW AND COLDER AIR MAY LEAD TO SOME LIGHT
SNOW SHOWERS ON SATURDAY OVER PORTIONS OF THE NORTHLAND. A
STRONGER SHORTWAVE WILL DIVE JUST SOUTHWEST OF THE CWA AND KEEP
THE HIGHER CHANCES FOR SNOW OUT OF OUR CWA. HIGHS SATURDAY WILL
RANGE FROM THE UPPER TEENS IN THE ARROWHEAD...TO THE TWENTIES
ELSEWHERE.
LONG TERM...SATURDAY NIGHT - THURSDAY...
SATURDAY NIGHT...THE NORTHLAND WILL BEGIN THE PERIOD IN COLD
NORTHWEST FLOW WITH A PASSING SHORTWAVE AND TROUGH. THERE COULD BE
LIGHT SNOW ACROSS THE SOUTHERN FA RELATED TO THE PASSING
SHORTWAVE...AND LAKE EFFECT SNOW SHOWERS ALONG PARTS OF THE SOUTH
SHORE DUE TO THE COLD NORTHWEST FLOW OVER THE LAKE. THE LATEST
MAV/MET/MEX GUIDANCE WAS INDICATING MUCH OVERNIGHT LOW
TEMPERATURES...SO LOWERED THE FORECAST.
SUNDAY...A RIDGE OF HIGH PRESSURE WILL MOVE INTO THE NORTHLAND
WHICH WILL RELAX THE NORTHWEST WINDS AND CAUSE CLEARING SKIES FROM
WEST TO EAST. THERE COULD BE LINGERING LAKE EFFECT SNOW SHOWERS
ALONG PARTS OF THE SOUTH SHORE...MOSTLY IN THE MORNING BEFORE THE
NORTHWESTERLY WINDS BECOME WESTERLY BY THE AFTERNOON.
SUNDAY NIGHT AND MONDAY...IT LOOKS LIKE A NORTHWEST TO SOUTHEAST
ORIENTATED WARM FRONT WILL MOVE INTO THE WESTERN FA OVERNIGHT AND
THE EASTERN FA MONDAY. THE FRONT COULD BRING LIGHT PCPN TO THE
FA...BUT THE MODELS DISAGREE ON THE TIMING/LOCATION/STRENGTH. BASED
ON SOUNDINGS...IT WOULD APPEAR THE PCPN WOULD INITIALLY FALL AS
LIGHT SNOW...BUT DRYING IN THE MID LEVELS BEHIND THE FRONT COULD
RESULT IN A MIXTURE OF LIGHT SNOW AND FREEZING DRIZZLE/RAIN ON
MONDAY.
MONDAY NIGHT THROUGH THURSDAY...THE MODELS SHOW A WEAK LOW PRESSURE
SYSTEM MOVING THROUGH THE UPPER MIDWEST WHICH COULD BRING LIGHT PCPN
TO THE NORTHLAND SOMETIME MONDAY NIGHT THROUGH TUESDAY NIGHT. BASED
ON SURFACE TEMPERATURES AND SOUNDINGS...IT WOULD APPEAR THERE COULD
BE A MIXTURE OF RAIN AND SNOW ACROSS THE FAR SOUTHERN FA TUESDAY. IT
THEN APPEARS WEAK HIGH PRESSURE WILL KEEP THE NORTHLAND DRY THROUGH
THE REMAINDER OF THE FORECAST.
&&
.POINT TEMPS/POPS...
DLH 30 16 22 2 / 80 10 10 10
INL 28 12 19 -6 / 40 10 20 10
BRD 30 16 24 2 / 80 10 20 10
HYR 32 14 23 2 / 80 50 10 10
ASX 33 17 24 6 / 80 50 20 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...GSF
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1127 AM CST FRI JAN 27 2012
.AVIATION...18Z TAF ISSUANCE...
AREA OF LOW PRESSURE WILL TRACK ACROSS THE SRN HALF OF THE
FORECAST AREA THIS AFTERNOON AND SPREAD SNOW SHOWERS THROUGH THE
REGION. SOME OF THESE SHOWERS COULD REDUCE VSBYS DOWN TO 1/2-1/4SM
AT TIMES...WITH TEMPORARY IFR CIGS AS WELL. THIS SYSTEM WILL BE
FAST MOVING...SO THESE CONDITIONS WILL BE SHORT-LIVED THIS
AFTERNOON. PREVAILING MVFR CIGS WITH POSSIBLE FLURRIES WILL
IMPROVE TO VFR THIS EVENING FOR MOST LOCATIONS...BUT CIGS DROP TO
MVFR AGAIN FOR HIB AND INL AFTER 06Z TONIGHT. DLH AND BRD COULD
SEE SOME LLWS THIS EVENING AND INTO THE OVERNIGHT HOURS...WITH
SPEED SHEAR BEING THE MAIN CONCERN AS SFC- 2000FT WINDS REMAIN
NEARLY UNIDIRECTIONAL. LIGHT LLWS WILL BE POSSIBLE AT ALL OTHER
TERMINALS THIS EVENING...HOWEVER CONFIDENCE IS LIMITED...THEREFORE
LEFT THE MENTION OUT OF 18Z TAFS. ANOTHER SURGE OF LOW LEVEL
MOISTURE MOVES IN FROM THE NW LATE TONIGHT...BUT CONFIDENCE IS LOW
REGARDING THE FORMATION OF LOW-END MVFR CIGS FOR THE SRN
TERMINALS...DLH...BRD AND HYR. SFC WINDS INCREASE FROM THE WNW
LATE SAT MORNING...WITH GUSTS 20-25 KNOTS.
&&
.PREV DISCUSSION... /ISSUED 934 AM CST FRI JAN 27 2012/
UPDATE...CURRENT RADAR TRENDS MATCH UP WELL WITH THE 11Z HRRR AND
HAVE ADJUSTED THE GRIDS THIS AFTERNOON TO LEAN TOWARDS ITS
SOLUTION. NO CHANGE FOR THE REST OF THIS MORNING.
PREV DISCUSSION... /ISSUED 546 AM CST FRI JAN 27 2012/
AVIATION...12Z TAF ISSUANCE...
A WEATHER SYSTEM WILL MOVE FROM EASTERN ND TO CENTRAL MN THIS
MORNING. EXPECT A PERIOD OF ABOUT 3 TO 5 HOURS OF IFR/MVFR CIGS AT
ALL TAF SITES...BEGINNING AT KBRD/KINL THIS MORNING...AND THEN AT
KHIB/KDLH/KHYR THIS AFTERNOON AS THE SYSTEM PASSES THROUGH
MN. THE PERIOD OF IFR/MVFR CIGS WILL BE ACCOMPANIED BY -SN AND
REDUCED VSBY. KINL SHOULD ESCAPE MOST OF THE SNOW...BUT
KBRD/KHIB/KDLH/KHYR WILL CLOSER TO THE FOCUS OF THE SNOWFALL AND
WILL SEE A PERIOD OF LOW END MVFR VSBYS. THIS WINDS TODAY WILL
GENERALLY BE LIGHT FROM THE WEST TO NORTHWEST...WITH SOME
INCREASING WESTERLY WINDS EARLY THIS EVENING. ONCE THE LOW MVFR
CIGS PASS...EACH TAF SITE SHOULD SEE HIGH BASED CIGS THROUGH
THE REST OF THE AFTERNOON AND INTO TONIGHT. WIND SHEAR MAY BE AN
ISSUE AT KBRD THIS EVENING DUE TO STRONG NORTHWEST WINDS
ALOFT...BUT OTHERWISE WIND SHEAR IS NOT EXPECTED TO BE AN ISSUE
FOR THE OTHER TAF SITES.
PREV DISCUSSION... /ISSUED 306 AM CST FRI JAN 27 2012/
SHORT TERM...THROUGH SATURDAY.
WE MADE SIGNIFICANT CHANGES TO THE FORECAST TODAY...NAMELY
SPREADING MUCH HIGHER POPS NORTH TO NEARLY THE INTERNATIONAL
BORDER.
SURFACE LOW PRESSURE OVER NORTH CENTRAL NORTH DAKOTA WILL MOVE ESE
TODAY...WITH 08Z SURFACE ANALYSIS SHOWING 2.5MB PRESSURE FALLS
JUST TO THE ESE OF THE LOW CENTER. THE GFS CONTINUES TO BE THE
FURTHEST SOUTH WITH THE TRACK OF THIS CLIPPER...AND THE RESULTANT
SNOW. THE 00Z ECMWF HAS SHIFTED THE LOW/PRECIP FURTHER NORTH...THE
NAM CONTINUES TO BE NORTH...AND THE HIGHER RESOLUTION 4KM WRF/3KM
HRRR SUGGEST SNOW WILL FALL FURTHER NORTH AS WELL. NAM ALSO SHOWS A
NICE FGEN SIGNATURE THAT MOVES THROUGH CASS/ITASCA COUNTIES...ESE
INTO WI. THERE WILL BE A NICE BURST OF SNOW THAT FALLS...AND 2 TO
3 INCHES IS EXPECTED IN THE MAIN AREA OF SNOW...WITH 1 TO 2 INCHES
NORTH AND SOUTH...AND EVEN LESS ALONG THE INTERNATIONAL BORDER. A
FEW HIGHER AMOUNTS WILL BE POSSIBLE AS WELL TO 4 INCHES. THE EXACT
LOCATION OF THE HEAVIER SNOW BAND AND THE SPEED OF THE SYSTEM
PRECLUDES US FROM ISSUING AN ADVISORY AT THIS TIME...BUT WE WILL
MONITOR RADAR OVER THE NEXT FEW HOURS AND ISSUE IF CONFIDENCE
INCREASES. AT THIS TIME...WE HAVE THE HIGHEST SNOW TOTALS ACROSS
NORTHERN CASS/SOUTHERN ITASCA COUNTIES INTO THE TWIN PORTS AND
ACROSS NORTHERN WISCONSIN.
SNOW SHOULD START THIS MORNING OVER OUR WESTERN CWA...REACH
THE EASTERN IRON RANGE...TWIN PORTS...INTERSTATE 35 CORRIDOR BY
EARLY AFTERNOON...THEN OUR EASTERN WISCONSIN ZONES BY MID-LATE
AFTERNOON.
THE SNOW WILL END IN OUR WEST THIS AFTERNOON...AND LINGER THROUGH
THE EVENING OVER PORTIONS OF NORTHWEST WISCONSIN.
COLDER AIR MOVES IN BEHIND THE LOW TONIGHT INTO SATURDAY. LOW
LEVEL FLOW IS TOO WESTERLY TO GET ANY SIGNIFICANT LES.
CYCLONIC UPPER LEVEL FLOW AND COLDER AIR MAY LEAD TO SOME LIGHT
SNOW SHOWERS ON SATURDAY OVER PORTIONS OF THE NORTHLAND. A
STRONGER SHORTWAVE WILL DIVE JUST SOUTHWEST OF THE CWA AND KEEP
THE HIGHER CHANCES FOR SNOW OUT OF OUR CWA. HIGHS SATURDAY WILL
RANGE FROM THE UPPER TEENS IN THE ARROWHEAD...TO THE TWENTIES
ELSEWHERE.
LONG TERM...SATURDAY NIGHT - THURSDAY...
SATURDAY NIGHT...THE NORTHLAND WILL BEGIN THE PERIOD IN COLD
NORTHWEST FLOW WITH A PASSING SHORTWAVE AND TROUGH. THERE COULD BE
LIGHT SNOW ACROSS THE SOUTHERN FA RELATED TO THE PASSING
SHORTWAVE...AND LAKE EFFECT SNOW SHOWERS ALONG PARTS OF THE SOUTH
SHORE DUE TO THE COLD NORTHWEST FLOW OVER THE LAKE. THE LATEST
MAV/MET/MEX GUIDANCE WAS INDICATING MUCH OVERNIGHT LOW
TEMPERATURES...SO LOWERED THE FORECAST.
SUNDAY...A RIDGE OF HIGH PRESSURE WILL MOVE INTO THE NORTHLAND
WHICH WILL RELAX THE NORTHWEST WINDS AND CAUSE CLEARING SKIES FROM
WEST TO EAST. THERE COULD BE LINGERING LAKE EFFECT SNOW SHOWERS
ALONG PARTS OF THE SOUTH SHORE...MOSTLY IN THE MORNING BEFORE THE
NORTHWESTERLY WINDS BECOME WESTERLY BY THE AFTERNOON.
SUNDAY NIGHT AND MONDAY...IT LOOKS LIKE A NORTHWEST TO SOUTHEAST
ORIENTATED WARM FRONT WILL MOVE INTO THE WESTERN FA OVERNIGHT AND
THE EASTERN FA MONDAY. THE FRONT COULD BRING LIGHT PCPN TO THE
FA...BUT THE MODELS DISAGREE ON THE TIMING/LOCATION/STRENGTH. BASED
ON SOUNDINGS...IT WOULD APPEAR THE PCPN WOULD INITIALLY FALL AS
LIGHT SNOW...BUT DRYING IN THE MID LEVELS BEHIND THE FRONT COULD
RESULT IN A MIXTURE OF LIGHT SNOW AND FREEZING DRIZZLE/RAIN ON
MONDAY.
MONDAY NIGHT THROUGH THURSDAY...THE MODELS SHOW A WEAK LOW PRESSURE
SYSTEM MOVING THROUGH THE UPPER MIDWEST WHICH COULD BRING LIGHT PCPN
TO THE NORTHLAND SOMETIME MONDAY NIGHT THROUGH TUESDAY NIGHT. BASED
ON SURFACE TEMPERATURES AND SOUNDINGS...IT WOULD APPEAR THERE COULD
BE A MIXTURE OF RAIN AND SNOW ACROSS THE FAR SOUTHERN FA TUESDAY. IT
THEN APPEARS WEAK HIGH PRESSURE WILL KEEP THE NORTHLAND DRY THROUGH
THE REMAINDER OF THE FORECAST.
&&
.POINT TEMPS/POPS...
DLH 30 16 22 2 / 80 10 10 10
INL 28 12 19 -6 / 40 10 20 20
BRD 30 16 24 2 / 80 10 20 20
HYR 32 14 23 2 / 80 50 10 10
ASX 33 17 24 6 / 80 50 20 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...GSF
AVIATION...TENTINGER
AREA FORECAST DISCUSSION
NWS DULUTH MN
934 AM CST FRI JAN 27 2012
.UPDATE...CURRENT RADAR TRENDS MATCH UP WELL WITH THE 11Z HRRR AND
HAVE ADJUSTED THE GRIDS THIS AFTERNOON TO LEAN TOWARDS ITS
SOLUTION. NO CHANGE FOR THE REST OF THIS MORNING.
&&
.PREV DISCUSSION... /ISSUED 546 AM CST FRI JAN 27 2012/
AVIATION...12Z TAF ISSUANCE...
A WEATHER SYSTEM WILL MOVE FROM EASTERN ND TO CENTRAL MN THIS
MORNING. EXPECT A PERIOD OF ABOUT 3 TO 5 HOURS OF IFR/MVFR CIGS AT
ALL TAF SITES...BEGINNING AT KBRD/KINL THIS MORNING...AND THEN AT
KHIB/KDLH/KHYR THIS AFTERNOON AS THE SYSTEM PASSES THROUGH
MN. THE PERIOD OF IFR/MVFR CIGS WILL BE ACCOMPANIED BY -SN AND
REDUCED VSBY. KINL SHOULD ESCAPE MOST OF THE SNOW...BUT
KBRD/KHIB/KDLH/KHYR WILL CLOSER TO THE FOCUS OF THE SNOWFALL AND
WILL SEE A PERIOD OF LOW END MVFR VSBYS. THIS WINDS TODAY WILL
GENERALLY BE LIGHT FROM THE WEST TO NORTHWEST...WITH SOME
INCREASING WESTERLY WINDS EARLY THIS EVENING. ONCE THE LOW MVFR
CIGS PASS...EACH TAF SITE SHOULD SEE HIGH BASED CIGS THROUGH
THE REST OF THE AFTERNOON AND INTO TONIGHT. WIND SHEAR MAY BE AN
ISSUE AT KBRD THIS EVENING DUE TO STRONG NORTHWEST WINDS
ALOFT...BUT OTHERWISE WIND SHEAR IS NOT EXPECTED TO BE AN ISSUE
FOR THE OTHER TAF SITES.
PREV DISCUSSION... /ISSUED 306 AM CST FRI JAN 27 2012/
SHORT TERM...THROUGH SATURDAY.
WE MADE SIGNIFICANT CHANGES TO THE FORECAST TODAY...NAMELY
SPREADING MUCH HIGHER POPS NORTH TO NEARLY THE INTERNATIONAL
BORDER.
SURFACE LOW PRESSURE OVER NORTH CENTRAL NORTH DAKOTA WILL MOVE ESE
TODAY...WITH 08Z SURFACE ANALYSIS SHOWING 2.5MB PRESSURE FALLS
JUST TO THE ESE OF THE LOW CENTER. THE GFS CONTINUES TO BE THE
FURTHEST SOUTH WITH THE TRACK OF THIS CLIPPER...AND THE RESULTANT
SNOW. THE 00Z ECMWF HAS SHIFTED THE LOW/PRECIP FURTHER NORTH...THE
NAM CONTINUES TO BE NORTH...AND THE HIGHER RESOLUTION 4KM WRF/3KM
HRRR SUGGEST SNOW WILL FALL FURTHER NORTH AS WELL. NAM ALSO SHOWS A
NICE FGEN SIGNATURE THAT MOVES THROUGH CASS/ITASCA COUNTIES...ESE
INTO WI. THERE WILL BE A NICE BURST OF SNOW THAT FALLS...AND 2 TO
3 INCHES IS EXPECTED IN THE MAIN AREA OF SNOW...WITH 1 TO 2 INCHES
NORTH AND SOUTH...AND EVEN LESS ALONG THE INTERNATIONAL BORDER. A
FEW HIGHER AMOUNTS WILL BE POSSIBLE AS WELL TO 4 INCHES. THE EXACT
LOCATION OF THE HEAVIER SNOW BAND AND THE SPEED OF THE SYSTEM
PRECLUDES US FROM ISSUING AN ADVISORY AT THIS TIME...BUT WE WILL
MONITOR RADAR OVER THE NEXT FEW HOURS AND ISSUE IF CONFIDENCE
INCREASES. AT THIS TIME...WE HAVE THE HIGHEST SNOW TOTALS ACROSS
NORTHERN CASS/SOUTHERN ITASCA COUNTIES INTO THE TWIN PORTS AND
ACROSS NORTHERN WISCONSIN.
SNOW SHOULD START THIS MORNING OVER OUR WESTERN CWA...REACH
THE EASTERN IRON RANGE...TWIN PORTS...INTERSTATE 35 CORRIDOR BY
EARLY AFTERNOON...THEN OUR EASTERN WISCONSIN ZONES BY MID-LATE
AFTERNOON.
THE SNOW WILL END IN OUR WEST THIS AFTERNOON...AND LINGER THROUGH
THE EVENING OVER PORTIONS OF NORTHWEST WISCONSIN.
COLDER AIR MOVES IN BEHIND THE LOW TONIGHT INTO SATURDAY. LOW
LEVEL FLOW IS TOO WESTERLY TO GET ANY SIGNIFICANT LES.
CYCLONIC UPPER LEVEL FLOW AND COLDER AIR MAY LEAD TO SOME LIGHT
SNOW SHOWERS ON SATURDAY OVER PORTIONS OF THE NORTHLAND. A
STRONGER SHORTWAVE WILL DIVE JUST SOUTHWEST OF THE CWA AND KEEP
THE HIGHER CHANCES FOR SNOW OUT OF OUR CWA. HIGHS SATURDAY WILL
RANGE FROM THE UPPER TEENS IN THE ARROWHEAD...TO THE TWENTIES
ELSEWHERE.
LONG TERM...SATURDAY NIGHT - THURSDAY...
SATURDAY NIGHT...THE NORTHLAND WILL BEGIN THE PERIOD IN COLD
NORTHWEST FLOW WITH A PASSING SHORTWAVE AND TROUGH. THERE COULD BE
LIGHT SNOW ACROSS THE SOUTHERN FA RELATED TO THE PASSING
SHORTWAVE...AND LAKE EFFECT SNOW SHOWERS ALONG PARTS OF THE SOUTH
SHORE DUE TO THE COLD NORTHWEST FLOW OVER THE LAKE. THE LATEST
MAV/MET/MEX GUIDANCE WAS INDICATING MUCH OVERNIGHT LOW
TEMPERATURES...SO LOWERED THE FORECAST.
SUNDAY...A RIDGE OF HIGH PRESSURE WILL MOVE INTO THE NORTHLAND
WHICH WILL RELAX THE NORTHWEST WINDS AND CAUSE CLEARING SKIES FROM
WEST TO EAST. THERE COULD BE LINGERING LAKE EFFECT SNOW SHOWERS
ALONG PARTS OF THE SOUTH SHORE...MOSTLY IN THE MORNING BEFORE THE
NORTHWESTERLY WINDS BECOME WESTERLY BY THE AFTERNOON.
SUNDAY NIGHT AND MONDAY...IT LOOKS LIKE A NORTHWEST TO SOUTHEAST
ORIENTATED WARM FRONT WILL MOVE INTO THE WESTERN FA OVERNIGHT AND
THE EASTERN FA MONDAY. THE FRONT COULD BRING LIGHT PCPN TO THE
FA...BUT THE MODELS DISAGREE ON THE TIMING/LOCATION/STRENGTH. BASED
ON SOUNDINGS...IT WOULD APPEAR THE PCPN WOULD INITIALLY FALL AS
LIGHT SNOW...BUT DRYING IN THE MID LEVELS BEHIND THE FRONT COULD
RESULT IN A MIXTURE OF LIGHT SNOW AND FREEZING DRIZZLE/RAIN ON
MONDAY.
MONDAY NIGHT THROUGH THURSDAY...THE MODELS SHOW A WEAK LOW PRESSURE
SYSTEM MOVING THROUGH THE UPPER MIDWEST WHICH COULD BRING LIGHT PCPN
TO THE NORTHLAND SOMETIME MONDAY NIGHT THROUGH TUESDAY NIGHT. BASED
ON SURFACE TEMPERATURES AND SOUNDINGS...IT WOULD APPEAR THERE COULD
BE A MIXTURE OF RAIN AND SNOW ACROSS THE FAR SOUTHERN FA TUESDAY. IT
THEN APPEARS WEAK HIGH PRESSURE WILL KEEP THE NORTHLAND DRY THROUGH
THE REMAINDER OF THE FORECAST.
&&
.POINT TEMPS/POPS...
DLH 30 16 22 2 / 80 10 10 10
INL 28 12 19 -6 / 40 10 30 20
BRD 30 16 24 2 / 80 10 20 20
HYR 32 14 23 2 / 80 50 10 10
ASX 33 17 24 6 / 80 50 20 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...GSF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
600 AM CST FRI JAN 27 2012
.AVIATION... /12Z TAF ISSUANCE/
LOW PRESSURE OVER EASTERN ND...WITH A COLD FRONT TRAILING SOUTH...
WILL REACH THE TWIN CITIES AROUND 21Z AND KEAU BY 02Z. CONFIDENCE
ON THE SNOW FORECAST TODAY IS LOW. THIS IS DUE TO THE SYSTEM
BASICALLY BEING IN TWO PARTS...ONE TO OUR NORTH AND THE OTHER TO
OUR SOUTH. REFLECTIVITY TRENDS IN THE VARIOUS WRF MODELS
OVERNIGHT ARE SUGGESTING MORE BANDING TO THE SNOW TODAY. THIS
WOULD MEAN MORE FLUCTUATIONS IN THE CEILING/VISIBILITY RATHER THAN
STEADY LOW CONDITIONS. TIMING REMAINS CONSISTENT WITH THE PREVIOUS
TAF PACKAGE WITH ADJUSTMENTS OF AN HOUR OR SO MADE. THE SNOW
TODAY WILL ONLY LAST FOR A COUPLE OF HOURS. RATHER STRONG
NORTHWEST WINDS WILL DEVELOP IN THE WAKE OF THE LOW...ESPECIALLY
AT KRWF AND KAXN. SPEEDS SUSTAINED IN THE 20 TO 25 KNOT RANGE
LIKELY ALONG WITH GUSTS APPROACHING 35 KNOTS. BRISK NORTHWEST
WINDS TO CONTINUE TONIGHT. THERE ARE SOME INDICATIONS THAT AN AREA
OF MVFR CEILINGS WILL SPREAD SOUTHEAST ACROSS EASTERN MN AND
WESTERN WI LATE TONIGHT AND SATURDAY AND THIS WAS INCLUDED IN
KMSP...KRNH AND KEAU AFTER 09Z.
KMSP...SOME LIGHT SNOW MAY REACH THE AIRFIELD BETWEEN 16Z AND
18Z...BUT THE MAIN SNOW REMAINS IN THE 18Z-21Z TIME FRAME WITH
VISIBILITY NEAR 1SM ALONG WITH CEILINGS DOWN TO VV008. THE SNOW
ENDS BY LATE AFTERNOON ALONG WITH WINDS SHIFTING TO THE NORTHWEST
(290-310) NEAR 15 KNOTS WITH GUSTS TO 25 KNOTS. THE WINDS WILL
CONTINUE THROUGH THE EVENING.
&&
.DISCUSSION... /ISSUED 427 AM CST FRI JAN 27 2012/
LIGHT SNOW EVENT STILL ON COURSE FOR TODAY. SNOW IN THE DAKOTAS
IS ONGOING WITH MOST OF THE AIRPORTS UNDERNEATH THE SNOW SHOWING
BETWEEN 1-2SM VISIBILITY. THE 27.00/06Z NAM/GFS AND 27.00Z EC NOT
DEVIATING TOO FAR FROM THURSDAY`S MODEL GUIDANCE. OVER THE PAST
24-30HR...THE MODEL SOLUTIONS HAVE SHIFTED THE BEST AXIS OF QPF
NORTH WITH TIME. LIKELY A FEW MORE LOCATIONS SEEING 2-4 INCHES
ACROSS NORTHERN PORTIONS OF MINNESOTA...ESPECIALLY GIVEN THE MORE
FAVORABLE PROFILE FOR DENDRITE SNOW GROWTH. THE MODEL GUIDANCE AND
EVEN THE RADAR THIS MORNING SHOWING TWO SEPARATE AREAS OF ENHANCED
SNOW...WITH A RELATIVE WEAKNESS OVER EASTERN SD. THESE TWO AREAS
LINE UP PRETTY WELL WITH THE 700-400MB DIFFERENTIAL VORTICITY
ADVECTION...AND SEEMS TO BE BETTER 850MB TEMPERATURE ADVECTION OFF
THE RUC IN THE VICINITY OF THESE TWO AREAS AS WELL. LOWEST SNOW
TOTALS WILL LIKELY BE IN WEST CENTRAL MN WHERE THE PRECIP SHOULD
LARGELY SPLIT THE AREA AND IT MIGHT ONLY MANAGE A TRACE OF SNOW.
THE TWO AREAS SHOULD FILL IN BY THE TIME THE WAVE MAKES IT INTO
EASTERN MN AND WESTERN WI EARLY THIS AFTERNOON...SO MOST LOCATIONS
WILL AT LEAST SEE A FEW TENTHS OF SNOW. TRIED TO TIME THE POP/WX
FORECAST WITH HOURLY GRIDS THIS MORNING AND WALK A BAND OF 60-90%
POPS ACROSS THE FORECAST AREA LATE THIS MORNING AND AFTERNOON.
PROBABLY COULD BE DONE A LITTLE MORE 80-100% POPS...BUT THE SNOW
WILL BE PRETTY LIGHT. BASED THE HOURLY TREND ON A LOT OF VARIOUS
WRF-NMM AND WRF-ARW SIMULATIONS FROM NCEP/SPC/MPX. MUCH BETTER
ISENTROPIC ADIABATIC OMEGA SLIDING ACROSS THE GRAND FORKS AND
DULUTH FORECAST AREAS. BEST CHANCE FOR 1-2" WILL BE ACROSS
PORTIONS OF CENTRAL MINNESOTA...LIKELY NEAR AND NORTH OF A LINE
FROM FERGUS FALLS...TO LITTLE FALLS...TO RICE LAKE IN WI. SNOW
LARGELY MOVES OUT OF THE FORECAST THIS EVENING.
BEYOND TODAY...THERE ARE A COUPLE OTHER MINOR SNOW EVENTS IN THE
WORKS SATURDAY THROUGH WEDNESDAY. NICE 500MB SHORT WAVE DROPS
SOUTH OUT OF SASKATCHEWAN ON SATURDAY WITH SOME SURFACE RESPONSE
AND A WEAK SURFACE TROUGH. CONVERGENCE ISN`T OVERLY STRONG...BUT
PROBABLY WORTH CHANCE POPS FOR SATURDAY AFTERNOON AND EVENING.
OVERALL THE WEEKEND WILL BE COOLER AFTER TODAY`S SYSTEM...BUT LIKE
SO MANY TIMES THIS WINTER...COLD FRONTS CAN ONLY MANAGE TO COOL AS
DOWN TO NEAR NORMAL. WARM FRONT COMES THROUGH SUNDAY NIGHT...SO
ONCE AGAIN HAVE SMALL POPS IN THE FORECAST DURING THIS TIME FRAME
DUE TO THE ISENTROPIC LIFT. EC IS A LITTLE STRONGER WITH THE UPPER
TROUGH AND SURFACE LOW ON TUESDAY COMPARED TO THE GFS...BUT IT`S
ALSO FARTHER TO THE NORTH. THE SECOND HALF OF NEXT WEEK IS QUITE
WARM IF YOU TRUST THE GFS AND THE PRONOUNCED LONG WAVE RIDGING.
THE EC HOLD THE RIDGE BACK TO THE WEST.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
RAH/CLF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
427 AM CST FRI JAN 27 2012
.DISCUSSION...
LIGHT SNOW EVENT STILL ON COURSE FOR TODAY. SNOW IN THE DAKOTAS IS
ONGOING WITH MOST OF THE AIRPORTS UNDERNEATH THE SNOW SHOWING
BETWEEN 1-2SM VISIBILITY. THE 27.00/06Z NAM/GFS AND 27.00Z EC NOT
DEVIATING TOO FAR FROM THURSDAY`S MODEL GUIDANCE. OVER THE PAST
24-30HR...THE MODEL SOLUTIONS HAVE SHIFTED THE BEST AXIS OF QPF
NORTH WITH TIME. LIKELY A FEW MORE LOCATIONS SEEING 2-4 INCHES
ACROSS NORTHERN PORTIONS OF MINNESOTA...ESPECIALLY GIVEN THE MORE
FAVORABLE PROFILE FOR DENDRITE SNOW GROWTH. THE MODEL GUIDANCE AND
EVEN THE RADAR THIS MORNING SHOWING TWO SEPARATE AREAS OF ENHANCED
SNOW...WITH A RELATIVE WEAKNESS OVER EASTERN SD. THESE TWO AREAS
LINE UP PRETTY WELL WITH THE 700-400MB DIFFERENTIAL VORTICITY
ADVECTION...AND SEEMS TO BE BETTER 850MB TEMPERATURE ADVECTION OFF
THE RUC IN THE VICINITY OF THESE TWO AREAS AS WELL. LOWEST SNOW
TOTALS WILL LIKELY BE IN WEST CENTRAL MN WHERE THE PRECIP SHOULD
LARGELY SPLIT THE AREA AND IT MIGHT ONLY MANAGE A TRACE OF SNOW.
THE TWO AREAS SHOULD FILL IN BY THE TIME THE WAVE MAKES IT INTO
EASTERN MN AND WESTERN WI EARLY THIS AFTERNOON...SO MOST LOCATIONS
WILL AT LEAST SEE A FEW TENTHS OF SNOW. TRIED TO TIME THE POP/WX
FORECAST WITH HOURLY GRIDS THIS MORNING AND WALK A BAND OF 60-90%
POPS ACROSS THE FORECAST AREA LATE THIS MORNING AND AFTERNOON.
PROBABLY COULD BE DONE A LITTLE MORE 80-100% POPS...BUT THE SNOW
WILL BE PRETTY LIGHT. BASED THE HOURLY TREND ON A LOT OF VARIOUS
WRF-NMM AND WRF-ARW SIMULATIONS FROM NCEP/SPC/MPX. MUCH BETTER
ISENTROPIC ADIABATIC OMEGA SLIDING ACROSS THE GRAND FORKS AND
DULUTH FORECAST AREAS. BEST CHANCE FOR 1-2" WILL BE ACROSS
PORTIONS OF CENTRAL MINNESOTA...LIKELY NEAR AND NORTH OF A LINE
FROM FERGUS FALLS...TO LITTLE FALLS...TO RICE LAKE IN WI. SNOW
LARGELY MOVES OUT OF THE FORECAST THIS EVENING.
BEYOND TODAY...THERE ARE A COUPLE OTHER MINOR SNOW EVENTS IN THE
WORKS SATURDAY THROUGH WEDNESDAY. NICE 500MB SHORT WAVE DROPS
SOUTH OUT OF SASKATCHEWAN ON SATURDAY WITH SOME SURFACE RESPONSE
AND A WEAK SURFACE TROUGH. CONVERGENCE ISN`T OVERLY STRONG...BUT
PROBABLY WORTH CHANCE POPS FOR SATURDAY AFTERNOON AND EVENING.
OVERALL THE WEEKEND WILL BE COOLER AFTER TODAY`S SYSTEM...BUT LIKE
SO MANY TIMES THIS WINTER...COLD FRONTS CAN ONLY MANAGE TO COOL AS
DOWN TO NEAR NORMAL. WARM FRONT COMES THROUGH SUNDAY NIGHT...SO
ONCE AGAIN HAVE SMALL POPS IN THE FORECAST DURING THIS TIME FRAME
DUE TO THE ISENTROPIC LIFT. EC IS A LITTLE STRONGER WITH THE UPPER
TROUGH AND SURFACE LOW ON TUESDAY COMPARED TO THE GFS...BUT IT`S
ALSO FARTHER TO THE NORTH. THE SECOND HALF OF NEXT WEEK IS QUITE
WARM IF YOU TRUST THE GFS AND THE PRONOUNCED LONG WAVE RIDGING.
THE EC HOLD THE RIDGE BACK TO THE WEST.
&&
.AVIATION.../06Z TAF ISSUANCE/
STILL A LOW RISK OF MVFR VSBYS IN FOG WEST CENTRAL WI FOR A SHORT
PERIOD OVERNIGHT UNTIL VFR CLOUDS MOVE INT, OTHERWISE LOW
PRESSURE CENTER AND TROUGH ON TARGET TO MOVE ACROSS THE AREA ON
FRIDAY...WITH LOW PRESSURE CENTER TRACKING ACROSS CENTRAL MN
DURING MID DAY. STILL LOOKS LIKE A 2-4 HOUR PERIOD OF SNOW WITH
THE LONGER DURATION OVER EASTERN SECTIONS OF THE FORECAST AREA.
THE GREATER RISK OF IFR VSBYS APPEARS TO BE ACROSS CENTRAL MN INTO
WEST CENTRAL WI AND POSSIBLY THE KMSP AREA. HAVE ADJUSTED THE
BEGINNING TIME A BIT LATER EASTERN AREAS. CIGS SHOULD PRIMARILY BE
MVFR IN THE SNOW BUT AREAS OF 1SM COULD YIELD IFR CIGS AS WELL.
THE LOWER CONDITIONS VCNTY KRWF NOT LIKELY TO LAST MUCH LONGER
THAN 2 HOURS. ACCUMULATIONS MOST AREAS COULD REACH AN INCH BUT UP
TO 2 INCHES CENTRAL AND EASTERN AREAS. A 2 HOUR PERIOD OF MVFR
CIGS COULD PERSIST BEHIND THE WAVE AND THEN SCT ON THE LOW CLOUDS
WEST LATER AFTERNOON AND THEN EASTERN MN FRIDAY EVENING.
THE OTHER ISSUE IS GUSTY NORTHWEST WINDS BEHIND THE TROUGH
ESPECIALLY OVER WEST CENTRAL MN. WILL INCLUDE THE HIGHER GUSTS NEAR
KRWF UP TO 30 KNOTS AND 20 TO 25 KNOTS OVER THE REST OF MN.
KMSP...VFR UNTIL SNOW MOVES IN 15Z-16Z WITH STILL A RISK OF IFR
VSBYS FOR 3 TO 4 HOURS AND DOWN TO 1SM AND CIGS 008. LOW END MVFR
BELOW 017 DOMINANT THOUGH. TIMING ABOUT AS PREV FORECAST BUT
PERHAPS A BIT LATER START. SNOW ACCUMULATION AROUND 1 INCH. HAVE
ADDED SOME CLEARING BEHIND THE WAVE FRIDAY EVENING. NORTHWEST
WINDS WITH GUSTS OF 22 KNOTS POSSIBLE BEHIND THE SYSTEM LATE
FRIDAY AFTERNOON AND CONTINUING INTO EVENING.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
CLF/JPR
AREA FORECAST DISCUSSION
NWS HASTINGS NE
421 PM CST FRI JAN 27 2012
.SHORT TERM...THROUGH SATURDAY AFTERNOON. PRIMARY CONCERNS ARE
TWO-FOLD...FIRST THE ONGOING WIND ADVISORY THIS AFTERNOON...AND
THEN POTENTIAL/LIKELY FIRE WEATHER ISSUES ON SATURDAY AFTERNOON.
AT 21Z...OBJECTIVE SURFACE ANALYSIS REVEALS A HEALTHY PRESSURE
GRADIENT ACROSS THE AREA...AS A 1022+MB HIGH SETTLES INTO THE
NORTHERN ROCKIES. WITH FORECAST SOUNDINGS INDICATING DEEP MIXING
TO AROUND 800MB...THE WIND ADVISORY FOR ALL BUT THE FAR EASTERN
CWA HAS WORKED OUT FAIRLY WELL...WITH SEVERAL AUTOMATED AIRPORT
SITES RECORDING SUSTAINED SPEEDS NEAR/JUST OVER 30 MPH...ALTHOUGH
PEAK GUSTS HAVE LARGELY TOPPED OUT AROUND 40 MPH...MAKING THIS A
LOW-END WIND ADVISORY OVERALL. ALOFT...AFTERNOON WATER VAPOR AND
SHORT TERM MODEL DATA CONFIRMS A BROAD SHORTWAVE TROUGH SWINGING
ACROSS THE CENTRAL CONUS. WITH PRIMARY ZONE OF SYNOPTIC SCALE LIFT
AND MID LEVEL SATURATION HAS BEEN OFF TO THE EAST FOR SEVERAL
HOURS NOW...WITH NO PRECIPITATION NOTED SO FAR THIS AFTERNOON
WITHIN THE CWA. TEMP WISE...HIGHS THIS AFTERNOON MET OR ONLY SLIGHTLY
EXCEEDED ORIGINAL FORECAST FROM THIS MORNING...RANGING FROM AROUND
40 IN THE NORTH TO UPPER 40S SOUTH.
LATE THIS AFTERNOON/TONIGHT...THE MAIN ISSUE IS THE ONGOING WIND
ADVISORY. WITH NAM FORECAST SOUNDINGS INDICATING A RAPID DIURNAL
DIMINISHMENT IN MIXING AROUND SUNSET...THE 00Z EXPIRATION TIME
LOOKS LIKE ON TARGET. THAT BEING SAID...IT WILL REMAIN RATHER
BREEZY WELL INTO THE EVENING HOURS...WITH SUSTAINED SPEEDS HOLDING
UP IN THE 15-20 MPH RANGE WITH HIGHER GUSTS. BY MIDNIGHT AND
THEREAFTER...SPEEDS SHOULD EASE DOWN INTO THE 5-15 MPH RANGE AND
TRANSITION MORE WESTERLY AS THE CENTER OF THE EXPANSIVE SURFACE
HIGH TO THE WEST SLIDES SOUTH. TURNING TO PRECIPITATION TRENDS
LATE THIS AFTERNOON/TONIGHT...INTRODUCED A MENTION OF
SCATTERED/ISOLATED FLURRIES THROUGH 03Z ACROSS MOST NEB ZONES...TO
ACCOUNT FOR UPSTREAM SNOW SHOWERS NOW EVIDENT OVER WESTERN/NORTH
CENTRAL NEBRASKA. THESE SNOW SHOWERS ARE A CLASSIC CASE OF PARTIAL
SUNSHINE ACTING UPON STEEP LOW LEVEL LAPSE RATES UNDER THE COLD
POCKET ALOFT...WITH THE LATEST SPC RUC MESOANALYSIS INDICATING 0-3KM
LAPSE RATES NOW IN THE 7.5-8.5 C/KM RANGE. SHORT TERM HIGH
RESOLUTION MODELS SUCH AS THE HRRR AND 4KM WRF-NMM HAVE HAD A GOOD
HANDLE ON THIS SNOW SHOWER/FLURRY ACTIVITY ALL DAY NOW...WITH THE
HRRR AND RADAR TRENDS CONFIRMING THAT THE WESTERN 1/2 OF THE CWA
IS MOST AT RISK FOR CATCHING SOME OF THIS FAST-MOVING ACTIVITY.
STRONGLY CONSIDERED ADDING A LOW MEASURABLE POP TO ACCOUNT FOR
POSSIBILITY THAT A FEW SPOTS MAINLY TOWARD DAWSON/VALLEY/SHERMAN
COUNTY AREA COULD MEASURE A QUICK FEW TENTHS OF SNOWFALL...BUT
WITH THE BETTER FOCUS REMAINING JUST NORTHWEST OF THE AREA...FELT
A SCATTERED FLURRY MENTION MIGHT BETTER CAPTURE THE BRIEF NATURE
OF ANY FALLING SNOW. AS LAPSE RATES LESSEN AFTER DARK AND THE
PRIMARY SHORTWAVE AXIS SLIDES EAST...ANY SNOW SHOWERS SHOULD
QUICKLY FADE AWAY...WITH LITTLE IF ANY RISK FOR THIS ACTIVITY
EXPECTED TO REMAIN BEYOND 03Z. TEMPERATURE WISE TONIGHT...THE
HEALTHY EVENING BREEZES SHOULD KEEP THINGS FROM DROPPING OFF VERY
QUICKLY...BUT EVENTUALLY EXPECT LOWS TO DROP INTO THE 17-21 RANGE
ACROSS MOST AREAS AS SKIES CLEAR...EXCEPT FOR SLIGHTLY COLDER READINGS
IN THE FAVORED SPOTS FROM VALLEY TOWARD DAWSON COUNTIES IN THE
WEST.
ON SATURDAY...THE MAIN CONCERN TURNS TO FIRE WEATHER...WHICH IS
COVERED IN THE FIRE WEATHER SECTION BELOW. ON THE LARGER SCALE
ALOFT...SLIGHT MID LEVEL HEIGHT RISES OCCUR AS BROAD RATHER HIGH
AMPLIFIED RIDGING DOMINATES THE WESTERN CONUS...WHILE OFF TO THE
EAST...THE PRIMARY SHORTWAVE PASSING THROUGH THE AREA TODAY WILL
SWING ACROSS THE SOUTHERN GREAT LAKES...WHILE AN UPSTREAM
SHORTWAVE/AREA OF CHANNELED VORTICITY SLIDES OUT OF CANADA INTO
THE EASTERN DAKOTAS. ANY PRECIPITATION ASSOCIATED WITH THIS WAVE
SHOULD REMAIN AT LEAST A FEW HUNDRED MILES OFF TO THE
NORTH/NORTHEAST OF THE CWA DURING THE AFTERNOON. IN THE LOW
LEVELS...IT WILL BE ANOTHER RATHER BREEZY LATE MORNING THROUGH
LATE AFTERNOON...BUT THIS TIME FROM THE WEST. NAM FORECAST
SOUNDINGS INDICATE IMPRESSIVE MIXING TO 800-750MB DURING THE
AFTERNOON. ALTHOUGH NOT ANTICIPATING ADVISORY LEVEL
WINDS...SUSTAINED SPEEDS OF 15-25 MPH WITH GUSTS 30-35 MPH WILL BE
COMMON. ALTHOUGH IT WILL REMAIN RATHER COOL ALOFT WITH 850MB TEMPS
ONLY RISING INTO THE -1 TO -3C RANGE DURING THE AFTERNOON...THE
DOWNSLOPE FLOW ALONG WITH NO WORSE THAN PARTLY CLOUDY SKIES SHOULD
MILK EVERY BIT OF WARMTH OUT OF THE AIRMASS AS POSSIBLE...AND
NUDGED HIGH TEMPERATURES UP SLIGHTLY FROM PREVIOUS FORECAST MOST
AREAS...WITH MOST NEB ZONES ADVERTISED BETWEEN 45-48...AND KS
ZONES 47-49. AS COVERED FURTHER IN THE FIRE WEATHER SECTION
BELOW...DEWPOINTS WERE LOWERED SEVERAL DEGREES FROM PREVIOUS
FORECAST.
.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY. THE MAJORITY OF THE
LONG TERM PERIOD WILL FEATURE WEST/NORTHWESTERLY FLOW ALOFT WITH
SEVERAL FAST MOVING WAVES RIPPLING THROUGH THE UPPER FLOW. THE
MEDIUM RANGE MODELS GENERALLY AGREE THAT THE BULK OF THE ENERGY
ASSOCIATED WITH THE WAVES NEVER REALLY TAKES DIRECT AIM AT THE
FORECAST AREA...AND WITH DRY AIR IN THE LOW LEVELS...PRECIPITATION
WILL BE HARD TO GENERATE. NOT TO SAY THERE MAY NOT BE A SMALL
CHANCE OF RAIN OR SNOW AT SOME POINT...BUT WITHOUT ANY DECENT
CHANCES OF PRECIPITATION SHOWN BY THE DETERMINISTIC RUNS...AND WITH
GEFS POPS SO LOW...WILL KEEP IT DRY THROUGH THE PERIOD.
TEMPERATURES THROUGH THE PERIOD SHOULD STAY ON THE WARM SIDE OF
NORMAL. IN FACT...MUCH OF NEXT WEEK SHOULD SEE HIGHS NEARLY 10 TO
15 DEGREES ABOVE SEASONAL AVERAGES. THE WARMEST DAY APPEARS TO BE
MONDAY WITH H85 TEMPERATURES NEAR 10 CELSIUS AND SOME MODEL
SOLUTIONS SUGGESTING HIGHS IN THE LOWER 60S. HAVE NOT GONE QUITE
THAT WARM IN THE GRIDS YET...BUT DO HAVE TEMPERATURES SOLIDLY IN THE
MID 50S TO NEAR 60. THERE SHOULD BE A COOL DOWN TOWARDS THE END OF
NEXT WEEK AS A COLD FRONT MOVES THROUGH THE REGION.
&&
.FIRE WEATHER...A FIRE WEATHER WATCH HAS BEEN ISSUED FOR THE
ENTIRE CWA FROM 18Z-00Z SATURDAY AFTERNOON...AND AN UPGRADE TO A
RED FLAG WARNING IS VERY POSSIBLE FOR AT LEAST WESTERN PORTIONS OF
THE WATCH AREA LATER TONIGHT. WITH DEEP MIXING NEAR/IN EXCESS OF
800MB EXPECTED...AND NEARLY DUE WESTERLY LOW LEVEL WINDS...THIS IS
A CLASSIC SET UP FOR A PRONOUNCED MIX-OUT OF DAYTIME DEW POINTS.
DESPITE SURFACE TEMPERATURES ONLY TOPPING OUT IN THE 40S...THE
ANTICIPATION OF DEWPOINTS FALLING INTO THE SINGLE DIGITS MOST
AREAS YIELDS A LARGE AREA OF AFTERNOON RELATIVE HUMIDITY VALUES
FALLING BETWEEN 15-23 PERCENT...ESPECIALLY FOR LOCATIONS SOUTHWEST
OF A LINE FROM ORD TO SUPERIOR...INCLUDING NORTH CENTRAL KANSAS.
THE LATEST ECMWF/GFS DETERMINISTIC SOLUTIONS EVEN SUGGEST THAT
DEWPOINTS COULD DROP BELOW ZERO ACROSS PARTS OF THE DISTRICT...AND
ALTHOUGH DIDN/T BUY THIS FULLY YET...ITS NOT OUT OF THE QUESTION
IN THIS WESTERLY WIND REGIME. AT ANY RATE...EASTERN PORTIONS OF
THE WATCH ARE OF LOWEST CONFIDENCE TO REACH RED FLAG
WARNING...WITH HIGHEST CONFIDENCE IN THE SOUTHWEST. THE WIND
CRITERIA OF 20 MPH SUSTAINED/GUSTS TO 25 MPH ARE NOT EXPECTED TO
BE A PROBLEM...SO EVERYTHING WILL HINGE ON THE COMBINATION OF
RISING TEMPERATURES/FALLING DEWPOINTS.
&&
.PREV DISCUSSION... /ISSUED 1139 AM CST FRI JAN 27 2012/
AVIATION...18Z KGRI TAF. VFR CEILING AND UNRESTRICTED VISIBILITY
FORECAST THROUGH THE PERIOD. HOWEVER...NORTH-NORTHWEST WINDS WILL
BE RATHER STRONG THIS AFTERNOON...WITH SEVERAL HOURS OF PEAK GUST
POTENTIAL TO AROUND 36KT BEFORE SUBSIDING THIS EVENING AND TURNING
MORE WESTERLY. WINDS WILL AGAIN INCREASE MID-LATE SATURDAY
MORNING FROM THE WEST...BUT WILL NOT BE QUITE AS STRONG AS THIS
AFTERNOON. AS FOR CLOUDS TRENDS...KEPT THINGS VFR...BUT THERE IS A
4-5 HOUR WINDOW THIS AFTERNOON FOR A BROKEN/OVERCAST CEILING IN
LOW-VFR RANGE AROUND 3500 FT AGL WHICH IS COVERED IN A TEMPO GROUP.
THE FINAL 18 HOURS OF THE PERIOD WILL FEATURE VERY LITTLE CLOUD
COVER...AND ONLY OF THE MID-HIGH VARIETY AT THAT. FINALLY...IT IS
NOT OUT OF THE QUESTION THAT A BRIEF PASSING SNOW SHOWER WILL
AFFECT THE AREA LATE THIS AFTERNOON INTO THIS EVENING...BUT WITH
THE BETTER CHANCES FOR THIS FOCUSING JUST OFF TO THE NORTH AND/OR
WEST...WILL OMIT THIS LOW CONFIDENCE SCENARIO FROM THE TAF FOR
NOW.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...FIRE WEATHER WATCH SATURDAY AFTERNOON FOR NEZ039>041-046>049-
060>064-072>077-082>087.
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ039>041-046>048-
060>063-072>076-082>086.
KS...FIRE WEATHER WATCH SATURDAY AFTERNOON FOR KSZ005>007-017>019.
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR KSZ005>007-017>019.
&&
$$
SHORT TERM/AVIATION/FIRE WEATHER...PFANNKUCH
LONG TERM...CK
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1150 AM CST FRI JAN 27 2012
.AVIATION...18Z TAFS FOR KOFK...KOMA AND KLNK.
VFR CONDITIONS ARE EXPECTED THRU THE TAF PD. SFC COLD FRONT JUST
MOVING THRU KOFK AT 18Z WILL CONTINUE TO PROGRESS RAPIDLY THRU
KOMA AND KLNK BY 20Z TURNING WINDS TO THE NORTHWEST WITH GUSTS
NEAR 30KTS. THERE IS A LOWER CLOUD DECK ASSOCIATED WITH THE
FRONTAL BOUNDARY THAT IS AROUND 3K FT AGL. WL NEED TO WATCH THIS
CLOSELY IN CASE IT FLUCTUATES LOWER THAN 3K FT AS IT APPROACHES
KLNK AND KOMA. WINDS WILL BEGIN TO DIMINISH BY 03Z AND BECOME MORE
SOUTHWEST BY MORNING.
KERN
&&
.PREV DISCUSSION... /ISSUED 752 AM CST FRI JAN 27 2012/
PREV DISCUSSION... /ISSUED 417 AM CST FRI JAN 27 2012/
DISCUSSION...
MAIN FORECAST CHALLENGE HAS BEEN ON PRECIPITATION
AMOUNTS/TYPE...MAINLY THIS MORNING...BUT APPARENTLY WITH MINOR
ACCUMULATIONS. AFTER THAT...WINDS THIS AFTERNOON AND THEN
TEMPERATURES ON MONDAY MAIN HAVE BEEN MAIN FOCUS.
MODEST SHORT WAVE ENERGY DROPPING SE TOWARD NORTHERN NEBRASKA THIS
MORNING WILL PROVIDE A SHOT OF STRONG LIFT TO FORECAST
AREA...ESPECIALLY NORTHERN ZONES. IT APPEARS LIFT WAS MOSTLY FROM
WARM ADVECTION EARLY AS ISENTROPIC UPGLIDE WAS STRONG IN 290-295
K LAYER. 06Z NAM LINGERED THIS LIFT LONGER INTO THIS AFTERNOON
COMPARED TO 00Z GFS...BUT NAM WAS MORE PROGRESSIVE WITH QPF FIELDS
COMPARED TO ITS 06Z RUC COUNTERPART. ALSO BASED ON TELCO/SURFACE
REPORTS THROUGH 09Z...QPF AMOUNTS FROM 06Z NAM APPEARED WAY TOO
HIGH. SO THAT MODEL APPEARED A LITTLE SUSPECT AND THUS LEANED
CLOSER TO GFS. SINCE MEASURABLE PRECIPITATION THROUGH 09Z HAD BEEN
HARD TO COME BY...LOWERED/DROPPED PRECIP MENTION EARLY THIS
MORNING SOUTHERN ZONES WITH SPRINKLES MENTIONED IN 15Z-18Z PD
AS SURFACE TEMPERATURES CLIMB ABOVE FREEZING. WILL COUNT ON LIFT
BEING STRONG ENOUGH TO COOL WARM LAYER ALOFT DOWN NORTHERN ZONES
SO THAT MAIN PRECIP TYPE EARLY WILL BE SNOW TRANSITIONING TO
SPRINKLES/FLURRIES AS BOUNDARY LAYER TEMPERATURES WARM WITH MIXING
LATER THIS MORNING. THAT LEFT A SMALL TRANSITION AREA ALONG PLATTE
RIVER WHERE NAM/GFS SUGGESTED A PERIOD OF FREEZING RAIN
POSSIBLE...ALTHOUGH THAT WILL BE CHANGED TO FREEZING SPRINKLES IN
LEGACY ZFP PRODUCT. TO FURTHER COMPLICATED MATTERS... LATEST RUC
SOUNDINGS KEPT ALL BUT FAR NW ZONES DRY INTO THIS AFTERNOON. AFTER
TROUGH PASSES...INCREASING NORTHWEST SURFACE WINDS COULD APPROACH
WIND ADVISORY CRITERIA W THROUGH NRN ZONES...BUT SPATIAL COVERAGE
AND LENGTH OF TIME WAS TOO UNCERTAIN TO ISSUE WIND ADVISORY WITH
THIS PACKAGE.
MADE LITTLE CHANGES TO TONIGHT THROUGH SUNDAY PERIOD. DECENT
MIXING AND WEAK WARM ADVECTION ON SATURDAY COULD PROVIDE A LITTLE
WARMER TEMPERATURES COMPARED TO TODAY. THEN SECONDARY PUSH OF
COLDER AIR SATURDAY NIGHT/EARLY SUNDAY FOLLOWED BY POSSIBLY MORE
CLOUDS/LESS MIXING LATER IN THE DAY COULD BRING A LITTLE COOLER
READINGS TO MOST AREAS ON SUNDAY. MAIN CHANGE IN TEMPERATURE
FORECAST WAS MADE TO THE MONDAY PERIOD WHERE HIGHS WERE RAISED BY
A CATEGORY OR SO. THERE WAS DECENT AGREEMENT BETWEEN 00Z GFS/ECMWF
IN WARMER H85 AIR ALREADY OVERSPREADING AREA BY 12Z MONDAY WITH
SUNSHINE...SW WINDS AND EVEN A BIT MORE WARM ADVECTION IN THE
AFTERNOON. PAST EVENTS SIMILAR TO THIS HAS PROVIDED 50S OVER SNOW
FREE AREAS. WITH DECENT CONSISTENCY IN MODEL RUNS...HIGHS OUTSIDE
OF EXPECTED SOME SNOW COVERED NORTHERN ZONES WERE RAISED INTO
50S...HIGHEST FAR S AND WEST CENTRAL.
AFTER THAT A SERIES OF FAST MOVING AND HARD-TO-TIME SYSTEMS BUT
OVERALL ABOVE NORMAL TEMPERATURES. FINE TUNING PROBABLY BEST LEFT
TO CLOSER TO ACTUAL TIME AND NO CHANGES WERE MADE TO A BLEND OF
MODEL/PREVIOUS FORECAST.
CHERMOK
AVIATION...
06Z TAFS FOR KOFK...KLNK AND KOMA.
DETERIORATING CONDITIONS ARE EXPECTED OVERNIGHT THROUGH 18Z AS A
STORM SYSTEM BRINGS SNOW TO NORTHEAST NEBRASKA...AND A RAIN SNOW
MIX TO KLNK AND KOMA. MID LEVEL CIGS WILL LOWER TO MVFR AT KOFK BY
10Z WITH OCCASIONAL IFR TO LIFR CIGS/VSBYS IN SNOW THROUGH 16Z.
MVFR CIGS WILL BE THE RULE AFTER 10Z AT KLNK AND KOMA WITH RAIN
AND SNOW LIKELY THROUGH 18Z. BRIEF PERIODS OF IFR VSBYS/CIGS MAY
OCCUR AT KOMA THROUGH THEN. A STRONG COLD FRONT WILL BRING AN END
TO THE PRECIPITATION BY ABOUT 18Z...BUT NORTHWEST WINDS OF 20 TO
30KTS AND BROKEN MVFR CIGS WILL FOLLOW. SKIES SHOULD CLEAR AND
WINDS DIE DOWN TOWARD 15KTS BY SHORTLY AFTER 00Z.
DERGAN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1139 AM CST FRI JAN 27 2012
.UPDATE...FOR THE MOST PART...FORECAST FOR TODAY REMAINS ON TRACK.
DRY AIR IN THE LOW LEVELS KEPT LEGITIMATE MEASURABLE PRECIPITATION
AT BAY THIS MORNING...WITH ONLY A FEW SNOW GRAINS/LIGHT SLEET
REPORTED IN SOME NORTHERN AREAS. FOR THIS AFTERNOON...PULLED
MEASURABLE SLIGHT CHANCE POP...BUT HAVE A SLIGHT CHANCE OF
FLURRIES/SPRINKLES GOING AFTER 20Z WITH CONTINUED SIGNAL FROM
SHORT TERM MODELS SUCH AS HRRR THAT STEEPENING LOW LEVEL LAPSE
RATES ACROSS WESTERN/NORTH CENTRAL NEB WILL EVENTUALLY SPARK SOME
ISOLATED/SCATTERED SNOW SHOWERS. ALTHOUGH MAIN FOCUS FOR THIS
ACTIVITY SHOULD REMAIN NORTH AND/OR WEST OF THE CWA...CERTAINLY
CANNOT RULE OUT SOME OF THIS ROAMING INTO THE AREA. THIS ACTIVITY
MAY EXTEND INTO THE EVENING HOURS AS WELL...AND MAY ADDRESS THIS
IN AFTERNOON UPDATE. AS FOR WIND ADVISORY...SEEMS TO BE ON TRACK
AND WILL LET RIDE AS IS. HOWEVER...A LOOK AT 12Z NAM FORECAST
SOUNDINGS INDICATES THAT THIS WILL LIKELY BE A MARGINAL
ADVISORY...THANKS TO WINDS AT THE TOP OF THE MIXED LAYER AROUND
800MB ONLY AVERAGING AROUND 40KT. AS A RESULT...ONLY EXPECTING
SUSTAINED SPEEDS AVERAGING AROUND 30 MPH...WITH PEAK GUSTS
GENERALLY 40-45 MPH. FOR TEMPS THIS AFTERNOON...TWEAKED 1-2
DEGREES UP IN A FEW AREAS...AS MANY AREAS ARE BRIEFLY SPIKING UP
AS INITIAL STRONG WINDS/INCREASED MIXING HITS...BUT FOR THE MOST
PART EXPECT NEAR-STEADY TEMPS MOST AREAS THIS AFTERNOON...WITH
HIGHS LOW 40S NORTH TO UPPER 40S SOUTH.
&&
.AVIATION...18Z KGRI TAF. VFR CEILING AND UNRESTRICTED VISIBILITY
FORECAST THROUGH THE PERIOD. HOWEVER...NORTH-NORTHWEST WINDS WILL
BE RATHER STRONG THIS AFTERNOON...WITH SEVERAL HOURS OF PEAK GUST
POTENTIAL TO AROUND 36KT BEFORE SUBSIDING THIS EVENING AND TURNING
MORE WESTERLY. WINDS WILL AGAIN INCREASE MID-LATE SATURDAY
MORNING FROM THE WEST...BUT WILL NOT BE QUITE AS STRONG AS THIS
AFTERNOON. AS FOR CLOUDS TRENDS...KEPT THINGS VFR...BUT THERE IS A
4-5 HOUR WINDOW THIS AFTERNOON FOR A BROKEN/OVERCAST CEILING IN
LOW-VFR RANGE AROUND 3500 FT AGL WHICH IS COVERED IN A TEMPO GROUP.
THE FINAL 18 HOURS OF THE PERIOD WILL FEATURE VERY LITTLE CLOUD
COVER...AND ONLY OF THE MID-HIGH VARIETY AT THAT. FINALLY...IT IS
NOT OUT OF THE QUESTION THAT A BRIEF PASSING SNOW SHOWER WILL
AFFECT THE AREA LATE THIS AFTERNOON INTO THIS EVENING...BUT WITH
THE BETTER CHANCES FOR THIS FOCUSING JUST OFF TO THE NORTH AND/OR
WEST...WILL OMIT THIS LOW CONFIDENCE SCENARIO FROM THE TAF FOR
NOW.
&&
.PREV DISCUSSION... /ISSUED 514 AM CST FRI JAN 27 2012/
SHORT TERM...TODAY THROUGH SUNDAY NIGHT. SOME PRECIPITATION TRYING
TO DEVELOP MAINLY IN THE NORTHERN CWA AS AN OCCLUDING FRONT MOVES
THROUGH. DEW POINT DEPRESSIONS ARE SO LARGE THAT PRECIPITATION
STRUGGLES TO REACH THE SURFACE. CUT BACK ON CHANCES OF PRECIPITATION
BECAUSE OF THIS. FREEZING RAIN LOOKS UNLIKELY AS TEMPERATURES HAVE
BUMPED UP THIS MORNING AT THE SURFACE. WILL BE EVEN MORE DIFFICULT
FOR PRECIPITATION TO MIX DOWN THE FARTHER SOUTH ONE GOES. WIND
ADVISORY IS STILL IN EFFECT FOR LATE MORNING/AFTERNOON WITH WINDS
ALOFT HAVING NO PROBLEM REACHING THE SURFACE WITH INCREASED LAPSE
RATES STEEPENING. THERE COULD BE SOME LIGHT SPRINKLE ACTIVITY...OR
EVEN FLURRY ACTIVITY IF IT OCCURS LATE ENOUGH IN THE AFTERNOON...AS
STEEP LAPSE RATES COMBINE WITH A MID-LEVEL TROUGH AXIS SWINGING
THROUGH IN THE AFTERNOON...SO I HAVE INCLUDED THIS FOR THE AFTERNOON
FOR THIS FORECAST.
TEMPERATURES WILL MODERATE INTO NEXT WEEK AS BROAD RIDGING OCCURS IN
THE WEST AND TROUGH IN THE EAST...WITH THE POLAR VORTEX FAR TO THE
NORTH. THIS TRANSLATES TO MILD AND DRY WEATHER FOR US INTO MONDAY.
LONG TERM...MONDAY THROUGH THURSDAY. MAIN FORECAST CONCERNS WILL BE
TEMPERATURES.
THE MAIN FEATURE DURING THE PERIOD IS A GENERAL NORTHWEST FLOW
ACROSS THE AREA. THERE ARE A FEW UPPER LEVEL WAVES THAT MOVE THROUGH
THE AREA. MODELS HAVE SOME DIFFERENCES IN THE TIMING OF THESE WAVES
AS THEM MOVE THROUGH THE AREA. DESPITE THE TIMING DIFFERENCES ALL
REMAIN DRY THROUGH THE PERIOD. TEMPERATURES THEN BECOME THE MAIN
CONCERN. MONDAY WILL LIKELY BE THE WARMEST DAY AHEAD OF A COLD FRONT
THAT MOVES THROUGH. THE TEMPERATURES BEHIND THE FRONT ARE COOLER BUT
ARE STILL ABOVE SEASONAL NORMALS.
LONG TERM...MONDAY THROUGH THURSDAY. MAIN FORECAST CONCERNS WILL BE
TEMPERATURES.
THE MAIN FEATURE DURING THE PERIOD IS A GENERAL NORTHWEST FLOW
ACROSS THE AREA. THERE ARE A FEW UPPER LEVEL WAVES THAT MOVE THROUGH
THE AREA. MODELS HAVE SOME DIFFERENCES IN THE TIMING OF THESE WAVES
AS THEM MOVE THROUGH THE AREA. DESPITE THE TIMING DIFFERENCES ALL
REMAIN DRY THROUGH THE PERIOD. TEMPERATURES THEN BECOME THE MAIN
CONCERN. MONDAY WILL LIKELY BE THE WARMEST DAY AHEAD OF A COLD FRONT
THAT MOVES THROUGH. THE TEMPERATURES BEHIND THE FRONT ARE COOLER BUT
ARE STILL ABOVE SEASONAL NORMALS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ039>041-046>048-
060>063-072>076-082>086.
KS...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR KSZ005>007-017>019.
&&
$$
UPDATE/AVIATION...PFANNKUCH
SHORT TERM...HEINLEIN
LONG TERM...JCB
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
752 AM CST FRI JAN 27 2012
AVIATION...
12Z TAFS FOR KOFK...KLNK AND KOMA.
BULK OF THE PRECIPITATION HAS MOVED TO THE NORTH OF THE TAF SITES
AND MAY SEE A BRIEF PERIOD OF A MIX OR SPRINKLES THROUGH 16Z AS
THE LIFT CONTINUES TO EXIT EASTERN NEBRASKA. CIGS SHOULD BE MAINLY
VFR. FOCUS THEN TURNS TO THE WINDS WHICH WILL INCREASE FROM THE
AT 18-25KT WITH GUSTS 25 TO 35KT AFTER 17Z. THE STRONG WINDS WILL
LAST INTO THE EARLY EVENING THEN DECREASE TO UNDER 12KTS AFTER
03Z.
&&
.PREV DISCUSSION... /ISSUED 417 AM CST FRI JAN 27 2012/
DISCUSSION...
MAIN FORECAST CHALLENGE HAS BEEN ON PRECIPITATION
AMOUNTS/TYPE...MAINLY THIS MORNING...BUT APPARENTLY WITH MINOR
ACCUMULATIONS. AFTER THAT...WINDS THIS AFTERNOON AND THEN
TEMPERATURES ON MONDAY MAIN HAVE BEEN MAIN FOCUS.
MODEST SHORT WAVE ENERGY DROPPING SE TOWARD NORTHERN NEBRASKA THIS
MORNING WILL PROVIDE A SHOT OF STRONG LIFT TO FORECAST
AREA...ESPECIALLY NORTHERN ZONES. IT APPEARS LIFT WAS MOSTLY FROM
WARM ADVECTION EARLY AS ISENTROPIC UPGLIDE WAS STRONG IN 290-295
K LAYER. 06Z NAM LINGERED THIS LIFT LONGER INTO THIS AFTERNOON
COMPARED TO 00Z GFS...BUT NAM WAS MORE PROGRESSIVE WITH QPF FIELDS
COMPARED TO ITS 06Z RUC COUNTERPART. ALSO BASED ON TELCO/SURFACE
REPORTS THROUGH 09Z...QPF AMOUNTS FROM 06Z NAM APPEARED WAY TOO
HIGH. SO THAT MODEL APPEARED A LITTLE SUSPECT AND THUS LEANED
CLOSER TO GFS. SINCE MEASURABLE PRECIPITATION THROUGH 09Z HAD BEEN
HARD TO COME BY...LOWERED/DROPPED PRECIP MENTION EARLY THIS
MORNING SOUTHERN ZONES WITH SPRINKLES MENTIONED IN 15Z-18Z PD
AS SURFACE TEMPERATURES CLIMB ABOVE FREEZING. WILL COUNT ON LIFT
BEING STRONG ENOUGH TO COOL WARM LAYER ALOFT DOWN NORTHERN ZONES
SO THAT MAIN PRECIP TYPE EARLY WILL BE SNOW TRANSITIONING TO
SPRINKLES/FLURRIES AS BOUNDARY LAYER TEMPERATURES WARM WITH MIXING
LATER THIS MORNING. THAT LEFT A SMALL TRANSITION AREA ALONG PLATTE
RIVER WHERE NAM/GFS SUGGESTED A PERIOD OF FREEZING RAIN
POSSIBLE...ALTHOUGH THAT WILL BE CHANGED TO FREEZING SPRINKLES IN
LEGACY ZFP PRODUCT. TO FURTHER COMPLICATED MATTERS... LATEST RUC
SOUNDINGS KEPT ALL BUT FAR NW ZONES DRY INTO THIS AFTERNOON. AFTER
TROUGH PASSES...INCREASING NORTHWEST SURFACE WINDS COULD APPROACH
WIND ADVISORY CRITERIA W THROUGH NRN ZONES...BUT SPATIAL COVERAGE
AND LENGTH OF TIME WAS TOO UNCERTAIN TO ISSUE WIND ADVISORY WITH
THIS PACKAGE.
MADE LITTLE CHANGES TO TONIGHT THROUGH SUNDAY PERIOD. DECENT
MIXING AND WEAK WARM ADVECTION ON SATURDAY COULD PROVIDE A LITTLE
WARMER TEMPERATURES COMPARED TO TODAY. THEN SECONDARY PUSH OF
COLDER AIR SATURDAY NIGHT/EARLY SUNDAY FOLLOWED BY POSSIBLY MORE
CLOUDS/LESS MIXING LATER IN THE DAY COULD BRING A LITTLE COOLER
READINGS TO MOST AREAS ON SUNDAY. MAIN CHANGE IN TEMPERATURE
FORECAST WAS MADE TO THE MONDAY PERIOD WHERE HIGHS WERE RAISED BY
A CATEGORY OR SO. THERE WAS DECENT AGREEMENT BETWEEN 00Z GFS/ECMWF
IN WARMER H85 AIR ALREADY OVERSPREADING AREA BY 12Z MONDAY WITH
SUNSHINE...SW WINDS AND EVEN A BIT MORE WARM ADVECTION IN THE
AFTERNOON. PAST EVENTS SIMILAR TO THIS HAS PROVIDED 50S OVER SNOW
FREE AREAS. WITH DECENT CONSISTENCY IN MODEL RUNS...HIGHS OUTSIDE
OF EXPECTED SOME SNOW COVERED NORTHERN ZONES WERE RAISED INTO
50S...HIGHEST FAR S AND WEST CENTRAL.
AFTER THAT A SERIES OF FAST MOVING AND HARD-TO-TIME SYSTEMS BUT
OVERALL ABOVE NORMAL TEMPERATURES. FINE TUNING PROBABLY BEST LEFT
TO CLOSER TO ACTUAL TIME AND NO CHANGES WERE MADE TO A BLEND OF
MODEL/PREVIOUS FORECAST.
CHERMOK
AVIATION...
06Z TAFS FOR KOFK...KLNK AND KOMA.
DETERIORATING CONDITIONS ARE EXPECTED OVERNIGHT THROUGH 18Z AS A
STORM SYSTEM BRINGS SNOW TO NORTHEAST NEBRASKA...AND A RAIN SNOW
MIX TO KLNK AND KOMA. MID LEVEL CIGS WILL LOWER TO MVFR AT KOFK BY
10Z WITH OCCASIONAL IFR TO LIFR CIGS/VSBYS IN SNOW THROUGH 16Z.
MVFR CIGS WILL BE THE RULE AFTER 10Z AT KLNK AND KOMA WITH RAIN
AND SNOW LIKELY THROUGH 18Z. BRIEF PERIODS OF IFR VSBYS/CIGS MAY
OCCUR AT KOMA THROUGH THEN. A STRONG COLD FRONT WILL BRING AN END
TO THE PRECIPITATION BY ABOUT 18Z...BUT NORTHWEST WINDS OF 20 TO
30KTS AND BROKEN MVFR CIGS WILL FOLLOW. SKIES SHOULD CLEAR AND
WINDS DIE DOWN TOWARD 15KTS BY SHORTLY AFTER 00Z.
DERGAN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
ZAPOTOCNY
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
417 AM CST FRI JAN 27 2012
.DISCUSSION...
MAIN FORECAST CHALLENGE HAS BEEN ON PRECIPITATION
AMOUNTS/TYPE...MAINLY THIS MORNING...BUT APPARENTLY WITH MINOR
ACCUMULATIONS. AFTER THAT...WINDS THIS AFTERNOON AND THEN
TEMPERATURES ON MONDAY MAIN HAVE BEEN MAIN FOCUS.
MODEST SHORT WAVE ENERGY DROPPING SE TOWARD NORTHERN NEBRASKA THIS
MORNING WILL PROVIDE A SHOT OF STRONG LIFT TO FORECAST
AREA...ESPECIALLY NORTHERN ZONES. IT APPEARS LIFT WAS MOSTLY FROM
WARM ADVECTION EARLY AS ISENTROPIC UPGLIDE WAS STRONG IN 290-295
K LAYER. 06Z NAM LINGERED THIS LIFT LONGER INTO THIS AFTERNOON
COMPARED TO 00Z GFS...BUT NAM WAS MORE PROGRESSIVE WITH QPF FIELDS
COMPARED TO ITS 06Z RUC COUNTERPART. ALSO BASED ON TELCO/SURFACE
REPORTS THROUGH 09Z...QPF AMOUNTS FROM 06Z NAM APPEARED WAY TOO
HIGH. SO THAT MODEL APPEARED A LITTLE SUSPECT AND THUS LEANED
CLOSER TO GFS. SINCE MEASURABLE PRECIPITATION THROUGH 09Z HAD BEEN
HARD TO COME BY...LOWERED/DROPPED PRECIP MENTION EARLY THIS
MORNING SOUTHERN ZONES WITH SPRINKLES MENTIONED IN 15Z-18Z PD
AS SURFACE TEMPERATURES CLIMB ABOVE FREEZING. WILL COUNT ON LIFT
BEING STRONG ENOUGH TO COOL WARM LAYER ALOFT DOWN NORTHERN ZONES
SO THAT MAIN PRECIP TYPE EARLY WILL BE SNOW TRANSITIONING TO
SPRINKLES/FLURRIES AS BOUNDARY LAYER TEMPERATURES WARM WITH MIXING
LATER THIS MORNING. THAT LEFT A SMALL TRANSITION AREA ALONG PLATTE
RIVER WHERE NAM/GFS SUGGESTED A PERIOD OF FREEZING RAIN
POSSIBLE...ALTHOUGH THAT WILL BE CHANGED TO FREEZING SPRINKLES IN
LEGACY ZFP PRODUCT. TO FURTHER COMPLICATED MATTERS... LATEST RUC
SOUNDINGS KEPT ALL BUT FAR NW ZONES DRY INTO THIS AFTERNOON. AFTER
TROUGH PASSES...INCREASING NORTHWEST SURFACE WINDS COULD APPROACH
WIND ADVISORY CRITERIA W THROUGH NRN ZONES...BUT SPATIAL COVERAGE
AND LENGTH OF TIME WAS TOO UNCERTAIN TO ISSUE WIND ADVISORY WITH
THIS PACKAGE.
MADE LITTLE CHANGES TO TONIGHT THROUGH SUNDAY PERIOD. DECENT
MIXING AND WEAK WARM ADVECTION ON SATURDAY COULD PROVIDE A LITTLE
WARMER TEMPERATURES COMPARED TO TODAY. THEN SECONDARY PUSH OF
COLDER AIR SATURDAY NIGHT/EARLY SUNDAY FOLLOWED BY POSSIBLY MORE
CLOUDS/LESS MIXING LATER IN THE DAY COULD BRING A LITTLE COOLER
READINGS TO MOST AREAS ON SUNDAY. MAIN CHANGE IN TEMPERATURE
FORECAST WAS MADE TO THE MONDAY PERIOD WHERE HIGHS WERE RAISED BY
A CATEGORY OR SO. THERE WAS DECENT AGREEMENT BETWEEN 00Z GFS/ECMWF
IN WARMER H85 AIR ALREADY OVERSPREADING AREA BY 12Z MONDAY WITH
SUNSHINE...SW WINDS AND EVEN A BIT MORE WARM ADVECTION IN THE
AFTERNOON. PAST EVENTS SIMILAR TO THIS HAS PROVIDED 50S OVER SNOW
FREE AREAS. WITH DECENT CONSISTENCY IN MODEL RUNS...HIGHS OUTSIDE
OF EXPECTED SOME SNOW COVERED NORTHERN ZONES WERE RAISED INTO
50S...HIGHEST FAR S AND WEST CENTRAL.
AFTER THAT A SERIES OF FAST MOVING AND HARD-TO-TIME SYSTEMS BUT
OVERALL ABOVE NORMAL TEMPERATURES. FINE TUNING PROBABLY BEST LEFT
TO CLOSER TO ACTUAL TIME AND NO CHANGES WERE MADE TO A BLEND OF
MODEL/PREVIOUS FORECAST.
CHERMOK
&&
.AVIATION...
06Z TAFS FOR KOFK...KLNK AND KOMA.
DETERIORATING CONDITIONS ARE EXPECTED OVERNIGHT THROUGH 18Z AS A
STORM SYSTEM BRINGS SNOW TO NORTHEAST NEBRASKA...AND A RAIN SNOW
MIX TO KLNK AND KOMA. MID LEVEL CIGS WILL LOWER TO MVFR AT KOFK BY
10Z WITH OCCASIONAL IFR TO LIFR CIGS/VSBYS IN SNOW THROUGH 16Z.
MVFR CIGS WILL BE THE RULE AFTER 10Z AT KLNK AND KOMA WITH RAIN
AND SNOW LIKELY THROUGH 18Z. BRIEF PERIODS OF IFR VSBYS/CIGS MAY
OCCUR AT KOMA THROUGH THEN. A STRONG COLD FRONT WILL BRING AN END
TO THE PRECIPITATION BY ABOUT 18Z...BUT NORTHWEST WINDS OF 20 TO
30KTS AND BROKEN MVFR CIGS WILL FOLLOW. SKIES SHOULD CLEAR AND
WINDS DIE DOWN TOWARD 15KTS BY SHORTLY AFTER 00Z.
DERGAN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BUFFALO NY
638 PM EST SAT JAN 28 2012
.SYNOPSIS...
LOW PRESSURE WILL LIFT JUST NORTH OF THE REGION TODAY...BRINGING A
SHARP COLD FRONT ACROSS THE REGION THROUGH THIS EVENING. THIS WILL
BRING WINDY CONDITIONS THIS EVENING AND SOME LAKE EFFECT SNOW EAST OF
THE LAKES TONIGHT. ANOTHER FAST MOVING LOW PRESSURE SYSTEM WILL
CROSS THE REGION SUNDAY...WHICH WILL BRING A A GENERAL LIGHT
SNOWFALL TO WESTERN NEW YORK FOLLOWED BY MORE LAKE EFFECT SNOW
EAST OF THE LAKES SUNDAY NIGHT. A THIRD FAST MOVING SYSTEM WILL
BRING ANOTHER CHANCE OF SNOW LATE MONDAY BEFORE ANOTHER SIGNIFICANT
WARM UP BY MIDWEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
MADE A QUICK UPDATE TO INCLUDE MONROE COUNTY IN THE WIND ADVISORY
THIS EVENING. WILL ALSO ISSUE A LAKE SHORE FLOOD ADVISORY FOR
CHAUTAUQUA AND SOUTHERN ERIE COUNTIES DUE TO THE POTENTIAL FOR MINOR
FLOODING WITH THE STRONG SOUTHWEST WINDS.
THE LATEST MOMENTUM TRANSFER SCHEMES SUGGEST THAT WINDS EAST OF LAKE
ONTARIO WILL ALSO GUST UP TO ADVISORY CRITERIA LATER THIS EVENING
THROUGH THE FIRST HALF OF TONIGHT. BASED ON THIS TREND...WILL
ISSUE A WIND ADVISORY FOR AREAS EAST OF LAKE ONTARIO.
LOW PRESSURE PASSING TO THE NORTH WILL DRAG A COLD FRONT ACROSS THE
REGION THROUGH THIS EVENING. AS OF 300 PM...ENTERING FAR WESTERN NEW
YORK NEAR BUFFALO.
THIS FRONT WILL BRING A PERIOD OF STRONG GUSTY WINDS...ESPECIALLY
ALONG LAKE ERIE AND THE NIAGARA FRONTIER. THE 12Z RUNS OF THE NAM/GFS
SHOWS WINDS AT 2000 FEET OF 50 TO 55 KTS...WITH SEVERAL RUC RUNS
SHOWING UP TO 60 KTS. WHILE THIS MAY NOT MIX DOWN ACROSS THE
INTERIOR VALLEYS...POST FRONTAL SW FLOW DO TYPICALLY MIX QUITE WELL
ACROSS FAR WESTERN NEW YORK...WHERE HIGHER TERRAIN HELPS FUNNEL
WINDS ALONG LAKE ERIE...AND ACROSS THE NIAGARA FRONTIER. EXPECT
SEVERAL HOURS OF WIND GUSTS TO 50 MPH IN THIS REGION...WITH THE
STRONGEST WINDS LIKELY BETWEEN 500 PM AND 900 PM.
THE OTHER ISSUE WITH THIS SYSTEM WILL BE SNOW FALL...MAINLY OF THE
LAKE EFFECT VARIETY. AHEAD OF THE FRONT...A BAND OF LIGHT SNOW WILL
WEAKEN AS IT MOVES EAST. WITH TEMPERATURES WARMER THERE...SNOW WILL
MIX WITH RAIN AT TIMES...WHICH WILL LIMIT PREFRONTAL ACCUMULATION.
WINDS WILL BOTH INCREASE AND SHIFT TO THE SW BEHIND THE FRONT. 850
MB TEMPERATURES WILL DROP TO AROUND -12C BEHIND THE FRONT...WHICH
WILL ONLY RESULT IN MODEST INSTABILITY OFF LAKE ERIE. WITH THE
STRONG FLOW LIMITING FETCH...EXPECT ONLY LIGHT LAKE EFFECT SNOWS OFF
LAKE ERIE...WITH VERY LIMITED ACCUMULATIONS.
OFF LAKE ONTARIO IS A DIFFERENT STORY...SINCE LAKE ONTARIO IS A BIT
WARMER...THE FLOW SHOULD BE FAIRLY WELL ALIENED FROM THE WSW ACROSS
THE LAKE. THIS WOULD PROBABLY STILL NOT BE ENOUGH FOR SIGNIFICANT
ACCUMULATIONS...EXCEPT THAT TERRAIN...ESPECIALLY THE TUG HILL...WILL
FURTHER ENHANCE QPF. THE ENTIRE REGION EAST OF LAKE ONTARIO SHOULD
GET AN INCH OR SO OF SNOW AHEAD OF THE FRONT LATE AFTERNOON. AFTER
THIS...LAKE EFFECT BANDS WILL SET UP...WITH WINDS LIKELY TO SUPPORT
A BAND SOMEWHERE NEAR OR JUST NORTH OF THE JEFFERSON/OSWEGO COUNTY
LINE. INITIALLY...EXPECT STRONG WINDS TO PREVENT AN ORGANIZED
CONVERGENCE BAND ON THE LAKE...WITH UPSLOPING THE BEST LIFTING
MECHANISM...FOCUSING STEADIEST SNOWS ON THE TUG HILL. THE RGEM KEYS
ON THIS...AS IT TYPICALLY WILL FORECAST LAKE BANDS WELL...BUT
INSTEAD IT KEYS ON THE UPSLOPING ON THE TUG HILL...AND ACROSS HIGHER
TERRAIN IN INTERIOR LEWIS COUNTY. WINDS WILL DIMINISH A BIT LATER IN
THE NIGHT...POTENTIALLY ALLOWING SOME ORGANIZATION OF A TIGHTER BUT
MORE INTENSE BAND...BEFORE MOISTURE DIMINISHES ON THE BACK OF THE
EXITING UPPER TROF. WILL KEEP THE ADVISORY AND SNOWFALL AMOUNTS IN
PLACE. CONFIDENCE IS NOT TERRIBLY HIGH...WITH STRONG WINDS
POTENTIALLY A LIMITING FACTOR...BUT GIVEN GOOD MOISTURE EARLY IN THE
EVENT...AND THE UPSLOPE COMPONENT...4 TO 7 INCHES STILL LOOKS
REASONABLE IN PORTIONS OF THE ADVISORY AREA.
FOR SUNDAY...A HIGH PRESSURE RIDGE WILL BRIEFLY BUILD TO THE
SOUTH...AS ANOTHER CLIPPER LOW DEVELOPS TO THE WEST. THE MORNING
HOURS WOULD BE UNEVENTFUL...EXCEPT FOR THE POTENTIAL FOR A LAKE
EFFECT BAND TO LIFT NORTHWARD ACROSS THE NIAGARA FRONTIER DURING THE
MORNING HOURS. WINDS WILL SHIFT FROM WSW TO SSW...SUPPORTING THE
LIFTING OF WHATEVER LAKE SNOWS REMAIN. INSTABILITY AND MOISTURE WILL
BE QUITE LIMITED BY THEN...BUT STILL MAY SEE A PERIOD OF LAKE SNOWS
DURING THE SUNDAY MORNING HOURS...WITH MINIMAL ACCUMULATION. A
SIMILAR STORY WILL PLAY OUT EAST OF LAKE ONTARIO...WITH THE BAND
THERE ALSO LIKELY TO LIFT NORTH TOWARD WATERTOWN TOWARD DAYBREAK.
AS LOW PRESSURE TRACKS ACROSS THE REGION LATE SUNDAY...EXPECT A
FAIRLY WIDESPREAD BUT GENERALLY LIGHT SNOWFALL FOR MOST OF THE
REGION. WHILE THE LAKES WILL PLAY SOME ROLE ENHANCING MOISTURE...THE
MAIN SOURCE OF LIFT WILL BE THE UPPER LEVEL TROF WITH THE LOW. THIS
SHOULD START IN MOST LOCATIONS DURING THE AFTERNOON HOURS. USING A
BLEND OF THE RGEM/NAM12 QPF...EXPECT AN INCH OR SO ACROSS INTERIOR
SECTIONS...WITH 1 TO 2 INCHES EAST OF THE LAKES.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
IN THE WAKE OF THE DEPARTING SURFACE LOW...COLDER AIR ARRIVES WITH
850 MB TEMPS FALLING FROM -8C TO -11C AT THE START OF THE NIGHT TO
ABOUT -14C/-15C BY MIDNIGHT. THIS WILL TRIGGER THE REDEVELOPMENT OF
SOME ACCUMULATING LAKE EFFECT SNOWS TO THE EAST AND EAST-SOUTHEAST
OF BOTH LAKES...WITH THE ACTIVITY PEAKING BETWEEN THE EARLY TO MID
EVENING AND EARLY OVERNIGHT HOURS...THEN WEAKENING THEREAFTER AS
STRONG LOW LEVEL RIDGING AND INCREASING AMOUNTS OF DRIER
AIR/SUBSIDENCE BUILD EAST FROM THE CENTRAL LAKES AND OHIO VALLEY.
THE SHORT-LIVED NATURE OF THE MOST FAVORABLE CONDITIONS WOULD TEND
TO RESULT IN BORDERLINE ADVISORY CRITERIA ACCUMULATIONS EAST AND
EAST-SOUTHEAST OF BOTH LAKES SUNDAY NIGHT...WITH THE BEST CHANCES
FOR THIS TO THE EAST-SOUTHEAST OF LAKE ONTARIO WHERE LONGER FETCH
AND MODEL-IMPLIED UPSTREAM CONNECTION TO GEORGIAN BAY WILL BE MORE
FAVORABLE.
DURING MONDAY...THE LOW LEVEL RIDGE AXIS WILL SHIFT EAST TO EASTERN
NEW YORK AND WESTERN NEW ENGLAND...WHILE THE NEXT WAVE OF LOW
PRESSURE PUSHES EAST INTO THE UPPER GREAT LAKES. IN BETWEEN THESE
TWO FEATURES...A WARM ADVECTION PATTERN WILL SET UP ACROSS THE
AREA...WEAKENING AND SUPPRESSING ANY REMAINING LAKE EFFECT SNOWS.
LATE MONDAY/MONDAY NIGHT WILL FEATURE SWATH OF LIGHT WARM ADVECTIVE
SNOW SHOWERS LIFTING NORTHEASTWARD ACROSS THE AREA...AS THE RIDGE OF
HIGH PRESSURE CONTINUES EASTWARD OF THE REGION AND THE WESTERN GREAT
LAKES LOW PUSHES ITS WARM FRONT NORTHEAST INTO NEW YORK STATE. WILL
BROADBRUSH MID-RANGE CHANCE POPS DURING THIS PERIOD...WHEN SOME
LIGHT SNOWFALL ACCUMULATIONS WILL BE POSSIBLE AREAWIDE.
TEMPS WILL BE MUCH CLOSER TO SEASONAL NORMALS ON SUNDAY NIGHT AND
MONDAY WITH LOWS IN THE MIDDLE TEENS TO LOWER 20S AND HIGHS IN THE
20S TO NEAR 30 DEGREES. EXPECT WARMER TEMPS AGAIN ON TUESDAY WITH
HIGHS IN THE MID TO UPPER 30S ACROSS THE NORTH COUNTRY AND THE LOWER
TO MID 40S ELSEWHERE. SOUTHERLY WINDS WILL KEEP TUESDAY NIGHT LOWS
QUITE MILD FOR THIS TIME OF YEAR WITH MID 20S TO LOW 30S EAST OF
LAKE ONTARIO AND THE LOWER TO MID 30S FOR THE REST OF THE FORECAST
AREA.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THIS PERIOD WILL FEATURE A RETURN TO A MORE PROGRESSIVE ZONAL
FLOW...WITH A SERIES OF LOW AMPLITUDE WAVES MOVING ALONG THE
CANADIAN BORDER AND KEEPING A GENERAL CHANCE OF PRECIP IN PLACE
RIGHT THROUGH THURSDAY. WITH MILDER PACIFIC AIR DOMINATING OUR
REGION UNDER THIS PATTERN...TEMPS WILL ONCE AGAIN REBOUND TO ABOVE
NORMAL LEVELS...AND WILL BE SUPPORTIVE OF A RAIN/SNOW MIX AT
NIGHT...WITH RAIN THE MORE DOMINANT PRECIP TYPE DURING THE DAYTIME
PERIODS. AT THIS POINT...THE WARMEST TIME FRAME APPEARS TO BE
WEDNESDAY...WHEN TEMPS SHOULD AT LEAST SURGE WELL INTO THE 40S IN
THE WARM SECTOR OF THE SECOND AND STRONGEST WAVE IN THE SERIES OF
SURFACE LOWS.
LATE IN THE PERIOD...THE GFS/ECMWF BOTH SUGGEST A RETURN OF
LARGER-SCALE TROUGHING ACROSS THE EASTERN THIRD OF THE COUNTRY AS
ANOTHER LARGE BUT ALSO PROGRESSIVE UPPER RIDGE BUILDS ACROSS THE
INTERMOUNTAIN WEST...WHICH WOULD RESULT IN A RETURN TO SEASONABLY
COLDER TEMPS FOR WEEK`S END. EXPECT A COLDER BUT DRY NORTHERLY FLOW
ON SATURDAY.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
WINDS WILL BE THE BIGGEST AVIATION CONCERN THROUGH THE EVENING. WEST
SOUTHWEST WINDS OF 20 TO 30 KNOTS WILL GUST TO 40 TO 45 KNOTS...
ESPECIALLY DOWNWIND OF THE LAKES THROUGH 03Z. WINDS WILL
GRADUALLY ABATE AFTER MIDNIGHT. CONDITIONS WILL BE MAINLY VFR...
BUT LAKE EFFECT SNOW SHOWERS COULD BRING MVFR/IFR CONDITIONS TO
KJHW AND KART AFTER 03Z.
SUNDAY SHOULD START OFF VFR/MVFR...HOWEVER A LAKE EFFECT SNOW BAND
MAY CROSS ART AT SOME POINT DURING THE MORNING HOURS. EXPECT
CIGS/VSBYS TO DROP TO MVFR OR EVEN IFR SUNDAY AFTERNOON AS A
SHORTWAVE RACES THROUGH THE AREA. CONFIGURATION OF THIS SYSTEM WILL
FOCUS AN AREA OF WIDESPREAD SNOW ACROSS THE REGION.
OUTLOOK...
SUNDAY NIGHT...MVFR/IFR CONDITIONS IN SNOW SHOWERS EARLY...IMPROVING
OVERNIGHT.
MONDAY...MVFR/IFR WITH AREAS OF SNOW.
TUESDAY...MAINLY VFR WITH SLIGHT CHANCE RAIN/SNOW SHOWERS.
WEDNESDAY AND THURSDAY...VFR/MVFR WITH A CHANCE OF RAIN SHOWERS.
&&
.MARINE...
AN AREA OF LOW PRESSURE WILL SWING BY JUST NORTH OF LAKES ERIE AND
ONTARIO THIS EVENING...WITH A SIGNIFICANT COLD FRONT CROSSING THE
LAKES LATE AFTERNOON AND EARLY EVENING. THE STRONGEST WINDS WILL BE
THROUGH THIS EVENING...AS A 50 TO 55 KT FLOW ALOFT PARTIALLY MIXES
DOWN IN THE SW FLOW BEHIND THE FRONT. EXPECT WINDS TO 40 KTS ACROSS
MUCH OF THE WATERS THIS EVENING...WITHOUT HIS GRADUALLY DIMINISHING
LATER TONIGHT.
WHILE WINDS WILL DIMINISH BELOW GALES LATE TONIGHT...MODERATE TO
STRONG WESTERLIES WILL CONTINUE SUNDAY AND SUNDAY NIGHT WITH SOLID
SMALL CRAFT ADVISORY CONDITIONS BEFORE HIGH PRESSURE BUILDS INTO THE
LOWER LAKES MONDAY WITH DIMINISHING WINDS.
OTHERWISE...A SERIES OF WEAK SYSTEMS WILL PASS THROUGH LATE NEXT
WILL...WITH WINDS GENERALLY ON THE LIGHT SIDE OUTSIDE OF A FEW
PERIODS WHERE SMALL CRAFT ADVISORIES MAY BE NEEDED.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST SUNDAY FOR NYZ007-
008.
WIND ADVISORY UNTIL 1 AM EST SUNDAY FOR NYZ006>008.
WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR NYZ001>003-010-
011-019-085.
LAKESHORE FLOOD ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ019-085.
MARINE...GALE WARNING UNTIL 4 AM EST SUNDAY FOR LEZ020-040-041.
GALE WARNING UNTIL 4 AM EST SUNDAY FOR LOZ030.
GALE WARNING UNTIL 7 AM EST SUNDAY FOR LOZ042>045-062>065.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL/TJP
SHORT TERM...WCH
LONG TERM...JJR/WCH
AVIATION...TMA
MARINE...APFFEL
AREA FORECAST DISCUSSION...UPDATED
NWS NEWPORT/MOREHEAD CITY NC
1023 PM EST SAT JAN 28 2012
.SYNOPSIS...
A DRY COLD FRONT WILL MOVE THROUGH THE AREA TONIGHT...THEN ANOTHER
SUNDAY NIGHT. HIGH PRESSURE WILL BUILD OVER THE SOUTHEAST MONDAY
THROUGH WEDNESDAY. A FRONTAL BOUNDARY WILL SLOWLY MOVE THROUGH THE
AREA THURSDAY NIGHT INTO FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 10 PM SAT...FORECAST LOOKS TO BE ON TRACK WITH THE COLD
FRONT ENCROACHING ON THE WESTERN PORTION OF THE CWA. ANTICIPATE
THE CALM/SWLY FLOW ACROSS MUCH OF THE REGION TO VEER TO THE NW AND
PICK UP IN INTENSITY OVER THE NEXT COUPLE OF HOURS...WITH WIND SPEEDS
AROUND 10 KTS WITH HIGHER GUSTS POSSIBLE AS THE FRONT MOVES
OFFSHORE EARLY SUNDAY MORNING. MINIMAL CLOUDS WILL ACCOMPANY THIS
FRONT...SO STILL EXPECT MOST CLEAR/PARTLY CLOUDY SKIES OVERNIGHT.
WHILE CAA WILL BE MAKING ITS WAY INTO THE AREA EARLY SUNDAY...THE
TEMPS WILL NOT DROP TO THEIR POTENTIAL GIVEN THE MIXING NEAR THE
SURFACE. THEREFORE..STILL FEEL TEMPS WILL DROP INTO THE LOWER/MID 30S
INLAND AND LOWER 40S ALONG THE COAST.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
AS OF 3 PM SAT...STRONG HIGH PRESSURE WILL CONTINUE TO BUILD OVER
THE DEEP SOUTH AND SE STATES. COOLER CONDITIONS EXPECTED SUN WITH
N FLOW EARLY BEHIND THE FRONT...BECOMING W/SW IN THE AFTERNOON.
LOW LEVEL THICKNESS VALUES AND MOSTLY SUNNY SKIES SUPPORT HIGH
TEMPS IN THE 50S...MUCH CLOSER TO CLIMO NORMS FOR LATE JAN.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
AS OF 3 PM SATURDAY...THE NORTHERN STREAM JET WILL DOMINATE EARLY
IN THE PERIOD WITH THE PASSAGE OF A SHORT WAVE TROUGH AND
ASSOCIATED SECONDARY DRY SURFACE COLD FRONT AGAIN SUNDAY NIGHT.
NEAR NORMAL HIGHS IN THE UPPER LOWER TO MIDDLE 50S ARE FORECAST ON
MONDAY AS AS COLD ADVECTION OCCURS WITH HIGH PRESSURE CRESTING
OVER THE AREA. A MODERATION IN TEMPERATURES INTO THE LOWER 60S
WILL OCCUR TUESDAY AS THE SURFACE HIGH MOVES OFF THE COAST AND
SOUTHERLY RETURN FLOW DEVELOPS. SOUTHERLY FLOW AND MILD
TEMPERATURES WELL INTO THE 60S WILL CONTINUE WEDNESDAY AND
THURSDAY. WEDNESDAY NIGHT A BACK DOOR COLD FRONT WILL STALL JUST
NORTH OF THE REGION THEN LIFT BACK TO THE NORTH THURSDAY AS
DEVELOPING LOW PRESSURE MOVES FROM THE TENNESSEE VALLEY TO OFF THE
MID ATLANTIC COAST. THIS SYSTEM WILL CIRCULATE MOISTURE FROM OFF
OF THE GULF OF MEXICO ACROSS THE CAROLINAS AND BRING A CHANCE OF
SHOWERS TO OUR REGION ON THURSDAY.
A COMPLEX PATTERN APPEARS TO BE SETTING UP FOR LATE NEXT INTO NEXT
WEEKEND AS A MEAN EASTERN UPPER TROUGH EVOLVES. A COLD FRONT WILL
APPROACH FROM THE WEST THURSDAY NIGHT...CROSSING THE REGION ON
FRIDAY BUT STALLING JUST SOUTH OF EASTERN NC. MILD TEMPERATURES ARE
EXPECTED TO CONTINUE FRIDAY AHEAD OF THE FRONT ALONG WITH A DECENT
CHANCE FOR SHOWERS. A SERIES OF WEAK LOW PRESSURE AREAS ARE FORECAST
TO MOVE ALONG THE STALLED FRONTAL BOUNDARY PRODUCING A COOLER AND
WET PATTERN ACROSS THE AREA OVER THE WEEKEND.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /THROUGH SUNDAY/
AS OF 620 PM SAT...VFR CONDITIONS EXPECTED THROUGH THE TAF
PERIOD. A DRY COLD FRONT WILL MOVE THROUGH EASTERN NC THIS
EVENING...WINDS WILL SHIFT TO NW AND MAY SEE A BRIEF WINDOW OF
GUSTS IN THE 15 TO 20 KT RANGE FROM 03Z THROUGH ABOUT 07Z. LIMITED
CLOUDS ASSOC WITH FRONT. MOSTLY CLEAR SKIES WILL CONT SUNDAY.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 3 PM SATURDAY...OUTSIDE OF THE USUAL LATE NIGHT AND EARLY
MORNING GROUND FOG THAT COULD CAUSE TEMPORARY REDUCTIONS IN
VISIBILITIES...PREVAILING VFR CONDITIONS ARE EXPECTED THROUGH
WEDNESDAY. A DRY COLD FRONT WILL CROSS THE AREA SUNDAY NIGHT. DRY
HIGH PRESSURE WILL THEN INFLUENCE THE WEATHER MONDAY THROUGH
WEDNESDAY. SOUTHERLY FLOW OFF OF THE GULF OF MEXICO AHEAD OF AN
APPROACHING COLD FRONT THURSDAY WILL BRING A CHANCE OF A FEW
SHOWERS WITH THE POSSIBILITY OF SUB VFR CONDITIONS.
&&
.MARINE...
SHORT TERM /THROUGH SUNDAY/...
AS OF 10 PM SAT...FORECAST LOOKS TO BE ON TRACK. CURRENT OBS ILLUSTRATE A
WSWLY FLOW AROUND 5-10KTS WITH SEAS HOVERING AROUND 3FT ACROSS THE
COASTAL WATERS. WINDS HAVE BEEN GUSTING AOA 20KT TO THE W
BEHIND FRONT AND MDLS SHOW GUSTY WINDS DEVELOPING ALONG THE COAST
AFTER FROPA. BASED ON LATEST RUC13 AND LOCAL WRF MDL HAVE ADDED
SCA FOR ALBEMARLE SOUND AS BOTH SHOW BRIEF PD OF 20 TO 25 KTS
LATER TONIGHT. WINDS WILL BE FAIRLY QUICK TO DIMINISH MID SUNDAY
MORNING AS FRONT MOVES FURTHER OFFSHORE. N WINDS WILL BACK THROUGH
THE DAY AND BECOME W/NW IN THE AFTERNOON.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 3 PM SATURDAY...MARGINAL SMALL CRAFT ADVISORY CONDITIONS
ARE EXPECTED AGAIN LATE SUNDAY NIGHT/EARLY MONDAY AS A SECONDARY
SURGE OF COOLER AIR PUSHES ACROSS THE WATERS. FREQUENT GUSTS TO 25
KT AND 5 TO 6 FT SEAS OVER THE OUTER WATERS WILL BE FORECAST.
CONDITIONS WILL IMPROVE AGAIN MONDAY AFTERNOON AND NIGHT AS A
STRONGER AND MORE PERSISTENT HIGH PRESSURE SYSTEM BUILDS OVER THE
WATERS. NW WINDS WILL DECREASE TO LESS THAN 15 KT MONDAY
AFTERNOON...AND 10 KT OR LESS MONDAY EVENING BEFORE BECOMING SW
10-15 KT LATE. SEAS WILL SUBSIDE TO 2 TO 3 FT MONDAY
AFTERNOON...AND 1-2 FT FOR MOST OF MONDAY NIGHT. SW WINDS 10-15 KT
WILL OCCUR TUESDAY AND TUESDAY NIGHT AS THE HIGH MOVES OFF THE
COAST WITH SEAS 2-3 FT TUESDAY BUILDING TO 3-4 FT TUESDAY NIGHT.
SW WINDS WILL INCREASE TO 15 TO 20 KT WEDNESDAY AHEAD OF A BACK
DOOR COLD FRONT WHOSE SOUTHERN EXTENT IS STILL UNDETERMINED.
CONSENSUS OF THE MODELS KEEP IT JUST NORTH OF THE NC WATERS.
MAGNITUDE AND DIRECTION OF WINDS FOR WEDNESDAY NIGHT INTO THURSDAY
STILL A LITTLE UNCERTAIN AS SOUTHWARD EXTENT OF BACK DOOR FRONT
UNKNOWN AND THERE WILL BE AN APPROACH OF A COLD FRONT FROM THE
WEST LATE. FOR NOW WILL FORECAST SW WINDS AROUND 15 KT AND SEAS
AROUND 3 FT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST SUNDAY FOR AMZ135.
SMALL CRAFT ADVISORY UNTIL 6 AM EST SUNDAY FOR AMZ130.
SMALL CRAFT ADVISORY UNTIL 1 PM EST SUNDAY FOR AMZ150-152-154.
SMALL CRAFT ADVISORY UNTIL 10 AM EST SUNDAY FOR AMZ156-158.
&&
$$
SYNOPSIS...CQD
NEAR TERM...LEP
SHORT TERM...CQD
LONG TERM...JME
AVIATION...RF/JME/CQD
MARINE...RF/JME/CQD/LEP
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
634 PM EST SAT JAN 28 2012
.SYNOPSIS...
A DRY COLD FRONT WILL MOVE THROUGH THE AREA TONIGHT...THEN ANOTHER
SUNDAY NIGHT. HIGH PRESSURE WILL BUILD OVER THE SOUTHEAST MONDAY
THROUGH WEDNESDAY. A FRONTAL BOUNDARY WILL SLOWLY MOVE THROUGH THE
AREA THURSDAY NIGHT INTO FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 630 PM SAT...NO SIGNIF CHANGES. SFC ANALYSIS SHOW COLD FRONT
APPROACHING CNTRL NC AND SWEEP ACROSS ERN NC BY 06Z. SATL SHOWS
LIMITED CLOUDS ASSOC WITH FRONT AND EXPECT MCLR SKIES TO CONT.
WILL SEE WINDS SHIFT TO NW LATE ER THIS EVENING...WILL BECOME
GUSTY ALONG THE CST. GOOD CAA EXPECTED LATER HOWEVER ATMS WILL
REMAIN RATHER MIXED RESULTING IN LOW TEMPS RANGING FROM LOWER 30S
INLAND TO LOWER 40S OBX.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
AS OF 3 PM SAT...STRONG HIGH PRESSURE WILL CONTINUE TO BUILD OVER
THE DEEP SOUTH AND SE STATES. COOLER CONDITIONS EXPECTED SUN WITH
N FLOW EARLY BEHIND THE FRONT...BECOMING W/SW IN THE AFTERNOON.
LOW LEVEL THICKNESS VALUES AND MOSTLY SUNNY SKIES SUPPORT HIGH
TEMPS IN THE 50S...MUCH CLOSER TO CLIMO NORMS FOR LATE JAN.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
AS OF 3 PM SATURDAY...THE NORTHERN STREAM JET WILL DOMINATE EARLY
IN THE PERIOD WITH THE PASSAGE OF A SHORT WAVE TROUGH AND
ASSOCIATED SECONDARY DRY SURFACE COLD FRONT AGAIN SUNDAY NIGHT.
NEAR NORMAL HIGHS IN THE UPPER LOWER TO MIDDLE 50S ARE FORECAST ON
MONDAY AS AS COLD ADVECTION OCCURS WITH HIGH PRESSURE CRESTING
OVER THE AREA. A MODERATION IN TEMPERATURES INTO THE LOWER 60S
WILL OCCUR TUESDAY AS THE SURFACE HIGH MOVES OFF THE COAST AND
SOUTHERLY RETURN FLOW DEVELOPS. SOUTHERLY FLOW AND MILD
TEMPERATURES WELL INTO THE 60S WILL CONTINUE WEDNESDAY AND
THURSDAY. WEDNESDAY NIGHT A BACK DOOR COLD FRONT WILL STALL JUST
NORTH OF THE REGION THEN LIFT BACK TO THE NORTH THURSDAY AS
DEVELOPING LOW PRESSURE MOVES FROM THE TENNESSEE VALLEY TO OFF THE
MID ATLANTIC COAST. THIS SYSTEM WILL CIRCULATE MOISTURE FROM OFF
OF THE GULF OF MEXICO ACROSS THE CAROLINAS AND BRING A CHANCE OF
SHOWERS TO OUR REGION ON THURSDAY.
A COMPLEX PATTERN APPEARS TO BE SETTING UP FOR LATE NEXT INTO NEXT
WEEKEND AS A MEAN EASTERN UPPER TROUGH EVOLVES. A COLD FRONT WILL
APPROACH FROM THE WEST THURSDAY NIGHT...CROSSING THE REGION ON
FRIDAY BUT STALLING JUST SOUTH OF EASTERN NC. MILD TEMPERATURES ARE
EXPECTED TO CONTINUE FRIDAY AHEAD OF THE FRONT ALONG WITH A DECENT
CHANCE FOR SHOWERS. A SERIES OF WEAK LOW PRESSURE AREAS ARE FORECAST
TO MOVE ALONG THE STALLED FRONTAL BOUNDARY PRODUCING A COOLER AND
WET PATTERN ACROSS THE AREA OVER THE WEEKEND.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /THROUGH SUNDAY/
AS OF 620 PM SAT...VFR CONDITIONS EXPECTED THROUGH THE TAF
PERIOD. A DRY COLD FRONT WILL MOVE THROUGH EASTERN NC THIS
EVENING...WINDS WILL SHIFT TO NW AND MAY SEE A BRIEF WINDOW OF
GUSTS IN THE 15 TO 20 KT RANGE FROM 03Z THROUGH ABOUT 07Z. LIMITED
CLOUDS ASSOC WITH FRONT. MOSTLY CLEAR SKIES WILL CONT SUNDAY.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 3 PM SATURDAY...OUTSIDE OF THE USUAL LATE NIGHT AND EARLY
MORNING GROUND FOG THAT COULD CAUSE TEMPORARY REDUCTIONS IN
VISIBILITIES...PREVAILING VFR CONDITIONS ARE EXPECTED THROUGH
WEDNESDAY. A DRY COLD FRONT WILL CROSS THE AREA SUNDAY NIGHT. DRY
HIGH PRESSURE WILL THEN INFLUENCE THE WEATHER MONDAY THROUGH
WEDNESDAY. SOUTHERLY FLOW OFF OF THE GULF OF MEXICO AHEAD OF AN
APPROACHING COLD FRONT THURSDAY WILL BRING A CHANCE OF A FEW
SHOWERS WITH THE POSSIBILITY OF SUB VFR CONDITIONS.
&&
.MARINE...
SHORT TERM /THROUGH SUNDAY/...
AS OF 630 PM SAT...LATEST BUOY OBS SHOW WSW 10KT OR
LESS...AND SEAS 2-4FT AHEAD OF COLD FRONT. FRONT WILL REACH SOUNDS
BY 04Z OR SO THEN BE OFFSHORE BY 06Z. WINDS HAVE BEEN GUSTING AOA
20KT TO THE W BEHIND FRONT AND MDLS SHOW GUSTY WINDS DEVELOPING
ALONG THE COAST AFTER FROPA. BASED ON LATEST RUC13 AND LOCAL WRF
MDL HAVE ADDED SCA FOR ALBEMARLE SOUND AS BOTH SHOW BRIEF PD OF
20 TO 25 KTS LATER TONIGHT. WINDS WILL BE FAIRLY QUICK TO
DIMINISH MID SUNDAY MORNING AS FRONT MOVES FURTHER OFFSHORE. N
WINDS WILL BACK THROUGH THE DAY AND BECOME W/NW IN THE AFTERNOON.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 3 PM SATURDAY...MARGINAL SMALL CRAFT ADVISORY CONDITIONS
ARE EXPECTED AGAIN LATE SUNDAY NIGHT/EARLY MONDAY AS A SECONDARY
SURGE OF COOLER AIR PUSHES ACROSS THE WATERS. FREQUENT GUSTS TO 25
KT AND 5 TO 6 FT SEAS OVER THE OUTER WATERS WILL BE FORECAST.
CONDITIONS WILL IMPROVE AGAIN MONDAY AFTERNOON AND NIGHT AS A
STRONGER AND MORE PERSISTENT HIGH PRESSURE SYSTEM BUILDS OVER THE
WATERS. NW WINDS WILL DECREASE TO LESS THAN 15 KT MONDAY
AFTERNOON...AND 10 KT OR LESS MONDAY EVENING BEFORE BECOMING SW
10-15 KT LATE. SEAS WILL SUBSIDE TO 2 TO 3 FT MONDAY
AFTERNOON...AND 1-2 FT FOR MOST OF MONDAY NIGHT. SW WINDS 10-15 KT
WILL OCCUR TUESDAY AND TUESDAY NIGHT AS THE HIGH MOVES OFF THE
COAST WITH SEAS 2-3 FT TUESDAY BUILDING TO 3-4 FT TUESDAY NIGHT.
SW WINDS WILL INCREASE TO 15 TO 20 KT WEDNESDAY AHEAD OF A BACK
DOOR COLD FRONT WHOSE SOUTHERN EXTENT IS STILL UNDETERMINED.
CONSENSUS OF THE MODELS KEEP IT JUST NORTH OF THE NC WATERS.
MAGNITUDE AND DIRECTION OF WINDS FOR WEDNESDAY NIGHT INTO THURSDAY
STILL A LITTLE UNCERTAIN AS SOUTHWARD EXTENT OF BACK DOOR FRONT
UNKNOWN AND THERE WILL BE AN APPROACH OF A COLD FRONT FROM THE
WEST LATE. FOR NOW WILL FORECAST SW WINDS AROUND 15 KT AND SEAS
AROUND 3 FT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 7 AM EST SUNDAY
FOR AMZ135.
SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 6 AM EST
SUNDAY FOR AMZ130.
SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 1 PM EST
SUNDAY FOR AMZ150-152-154.
SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST SUNDAY
FOR AMZ156-158.
&&
$$
SYNOPSIS...CQD
NEAR TERM...RF
SHORT TERM...CQD
LONG TERM...JME
AVIATION...RF/CQD/JME
MARINE...RF/CQD/JME
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
307 PM EST FRI JAN 27 2012
.SYNOPSIS...
DRIER AIR WILL MOVE INTO THE EASTERN CAROLINAS TONIGHT AS HIGH
PRESSURE BUILDS OVERHEAD EARLY SATURDAY. A DRY COLD FRONT WILL
PUSH THROUGH FROM THE WEST SATURDAY NIGHT...FOLLOWED BY CHILLY
TEMPERATURES ON SUNDAY AND MONDAY AS A NEW HIGH MOVES TOWARD THE
CAROLINAS. A WARMING TREND IS EXPECTED MID-WEEK...AND THE NEXT
FRONT WILL BRING A CHANCE OF RAIN THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM FRIDAY...DRY AIR WILL CONTINUE TO MAKE ITS WAY IN THIS
AFTERNOON IN GUSTY WESTERLY WINDS. WINDS WILL REMAIN GUSTY AS THEY
CONTINUE TO SHIFT AROUND TO THE W-NW THROUGH LATE THIS AFTERNOON.
LATEST NAM SHOWING SHORTWAVE LIFTING OFF TO THE NORTHEAST WITH MORE
OF A ZONAL FLOW DEVELOPING BEHIND IT THROUGH OVERNIGHT. INITIALLY
WILL SEE DEEPER NORTHWEST FLOW WITH COOLER AND DRIER AIR MAKING ITS
WAY IN BUT BY MORNING WILL SEE FAIRLY NEUTRAL TEMP ADVECTION. 850
TEMPS ACTUALLY DROP THROUGH THIS EVENING 5 OR 6C BEFORE LEVELING OFF
TONIGHT. MAX PCP WATER RIGHT ALONG THE COAST NEAR AN INCH WILL
CONTINUE TO FALL OFF AS DRY AIR CONTINUES TO MOVE IN. PCP WATER
VALUES WILL BE DOWN LESS THAN A HALF INCH BY MORNING. ALTHOUGH THERE
MAY BE SOME RESIDUAL MOISTURE ON THE GROUND IN AREAS WITH PCP THIS
MORNING...EXPECT ENOUGH DRYING TO OCCUR TO KEEP ANY FOG OUT OF
FORECAST.
CLEARING SKIES...LIGHTER WINDS AND SOME CAA WILL ALLOW TEMPS TO
DROP THROUGH THE NIGHT DOWN NEAR 40 OR JUST BELOW FURTHER INLAND.
DRIER AIR MAKING ITS WAY IN WILL PRODUCE A DROP IN DEWPOINT TEMPS
DOWN INTO THE MID 30S IN DIMINISHING NW TO N WINDS OVERNIGHT.
GUSTY WESTERLY WINDS WILL SHIFT TO THE NW AND DIMINISH THROUGH THIS
EVENING AS GRADIENT WEAKENS.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...TRANSITORY AND VERY WEAK SURFACE HIGH ACROSS
THE EASTERN CAROLINAS SATURDAY MORNING WILL SLIDE OFFSHORE DURING
THE AFTERNOON. THIS WILL BE FOLLOWED BY AN EQUALLY WEAK SHOT OF
WARM ADVECTION IN THE GAP BETWEEN THE DEPARTING HIGH AND AN
INCOMING DRY ARCTIC COLD FRONT. THIS ARCTIC FRONT WILL SWEEP
SOUTHEAST AND ACROSS THE AREA SATURDAY EVENING...FOLLOWED BY A ~12
HOUR PERIOD OF COLD ADVECTION THAT WILL DROP 850 MB TEMPS FROM +9C
LATE SATURDAY AFTERNOON TO AROUND 0C SUNDAY MORNING. ONLY A STEADY
BREEZE SATURDAY NIGHT INTO SUNDAY MORNING WILL KEEP LOW TEMPERATURES
FROM FALLING BELOW FREEZING ALL THE WAY DOWN TO THE COAST.
PRECIPITABLE WATER WILL REMAIN 0.5 INCHES OR LESS THROUGH THE
WEEKEND. WITH VERY LITTLE IF ANY LOW-LEVEL CLOUD COVER EXPECTED
THIS GIVES US HIGH CONFIDENCE IN A DRY FORECAST THROUGH THE PERIOD.
GFS AND NAM MOS HIGHS/LOWS DON`T LOOK BAD AND WERE VERY CLOSE TO
OUR PREVIOUS FORECAST NUMBERS. THERE IS A RATHER SUBSTANTIAL
DIFFERENCE IN LOW-LEVEL TEMPERATURES ON THE RAW MODELS SUNDAY
NIGHT (NAM WARMER THAN THE GFS BY 5-7 DEGREES F WITHIN THE
300-1500 FT AGL LAYER) BUT THIS HAD LITTLE IMPACT ON MOS LOWS...
PROBABLY DUE TO LIGHTER WIND SPEEDS IN THE NAM VERSUS THE GFS.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 PM FRIDAY...A DRY ATMOSPHERE MONDAY AND TUESDAY THROUGH
THE COLUMN AS SUBSIDENCE ALOFT ENSUES IN WAKE OF A DEPARTING UPPER
TROUGH LIFTING NE OVER NEW ENGLAND AND CANADIAN MARITIME PROVINCES.
AT GROUND LEVEL...AN ANTICYCLONE WILL BE EDGING INTO THE FORECAST
AREA DAYBREAK MONDAY...SLIPPING OFFSHORE DURING THE DAY TUESDAY.
GLOBAL MODELS ILLUSTRATING SOLID AGREEMENT MUCH OF NEXT WEEK IN
BRINGING RETURN FLOW...INCREASING LOW-LEVEL MOISTURE...AND MILD
TEMPERATURES FOR THE SEASON BEGINNING WEDNESDAY. LOW PRESSURE
EMERGING FROM THE GULF COAST STATES SHOULD BRING AN INCREASING
CHANCE OF RAIN ACROSS OUR AREA LATE WEDNESDAY AND EVEN MORE-SO BY
THURSDAY...AS THE LOW BECOME ENERGIZED BY A NORTHERN STREAM UPPER
TROUGH DIGGING ITS WAY ACROSS THE MIDDLE MISSISSIPPI VALLEY
THURSDAY INTO FRIDAY.
WHILE MODEL DIVERGENCE INCREASES DAYS 6/7...IT DOES APPEAR THE
IDEA OF AN APPROACHING UPPER TROUGH WILL SEE FRUITION. COUPLING
THIS WITH LOW-LEVEL CONVERGENCE ASSOCIATED WITH SFC LOW PRESSURE
MOVING ACROSS THE CAROLINAS...HAS PROMPTED ELEVATING POP VALUES TO
A CHANCE OF SHOWERS THURSDAY AND FRIDAY. INDICATED DRYING FROM THE
WEST LATE IN THE PERIOD OF DAY 7...BUT OBVIOUSLY WE WILL SEE
TIMING ADJUSTMENTS OR CHANGES WITH ADDITIONAL MODEL RUNS. IF THE
GFS IS CORRECT A COOL AND DRY WEEKEND...WHEREAS IF THE ECMWF HAS
ITS SAY...WE COULD REMAIN UNSETTLED INTO NEXT WEEKEND AS THE UPPER
TROUGH HOLDS WEST OF THE AREA ACROSS THE TENNESSEE VALLEY.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 18Z...COLD FRONT PUSHING TO THE COAST WITH VFR CONDITIONS AT
ALL TERMINALS. THE HRRR MODEL IS HINTING AT A SMALL BAND OF LIGHT
SHOWERS FORMING BEHIND THE MAIN MOISTURE SOURCE IN THE EARLY PORTION
OF THE AFTERNOON...BUT WITH THE RAPIDLY LOWERING DEWPOINTS...THINK
THIS IS UNLIKELY. GUSTY WEST WINDS WILL DIMINISH BY EARLY
EVENING...WITH LIGHT WINDS EXPECTED AT ALL TERMINALS THROUGH THE
NIGHTTIME HOURS. THERE WILL BE A SLIGHT CHANCE FOR FOG GIVEN THE LOW
LEVEL MOISTURE...HOWEVER THE VERTICAL CHANCE IN HUMIDITY IS NOT
FAVORABLE. SATURDAY...EXCELLENT AVIATION WEATHER WITH SCATTERED
SKIES AND GOOD VISIBILITIES. WINDS WILL BE LIGHT AND VARIABLE WITH
HIGH PRESSURE DIRECTLY OVERHEAD.
EXTENDED OUTLOOK...POTENTIAL MORNING FOG TUESDAY AND
WEDNESDAY...OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM FRIDAY...TIGHTENED GRADIENT FLOW WILL PERSIST THROUGH
THIS AFTERNOON WITH SW WINDS AROUND 20 TO 25 KTS WITH HIGHER GUSTS.
AS NORTHERN STREAM SHORTWAVE PUSHES NEXT FRONT ACROSS THE WATERS
LATER TODAY SW-W WINDS WILL SHIFT TO A MORE NW DIRECTION AND SPIKE
UP A BIT BEFORE DIMINISHING THROUGH THE NIGHT.
AS COOLER AND DRIER AIR MAKES ITS WAY IN OVERNIGHT IT WILL PRODUCE
GREATER MIXING AND KEEP GUSTIER WINDS INITIALLY. COOLER SHELF WATERS
KEEPING A MORE STABLE ENVIRONMENT WILL NOT EXPERIENCE THE STRONGER
WIND GUSTS TAKING PLACE OVER THE WARMER GULF STREAM WATERS FURTHER
OFF SHORE. AS WINDS CONTINUE TO VEER AROUND TO THE NORTH THROUGH
MORNING...THE GRADIENT WILL RELAX AND WINDS WILL DIMINISH AS HIGH
PRESSURE MOVES IN FROM THE WEST. WINDS WILL BE DOWN TO 10 TO 15 MPH
OUT OF THE NORTH BY MORNING.
AS WINDS DIMINISH IN AN OFF SHORE FLOW...SEAS WILL DROP OFF QUITE
RAPIDLY OVERNIGHT. EXPECT SEAS UP AROUND 6 TO 8 FT IN OUTER WATERS
THIS AFTERNOON TO DECREASE BELOW 5 FT BY MIDNIGHT AND SEAS WILL BE
DOWN LESS THAN 4 FT BY MORNING.
CLEARING SKIES...LIGHTER WINDS AND SOME CAA WILL ALLOW TEMPS TO
DROP THROUGH THE NIGHT DOWN NEAR 40 OR JUST BELOW FURTHER INLAND.
DRIER AIR MAKING ITS WAY IN WILL PRODUCE A DROP IN DEWPOINT TEMPS
DOWN INTO THE MID 30S IN DIMINISHING NW TO N WINDS OVERNIGHT.
GUSTY WESTERLY WINDS WILL SHIFT TO THE NW AND DIMINISH THROUGH THIS
EVENING AS GRADIENT WEAKENS.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...VERY TRANSITORY HIGH PRESSURE WILL ZIP ACROSS
THE AREA SATURDAY MORNING WITH A PERIOD OF LIGHT AND VARIABLE
WINDS. BEHIND THE DEPARTING HIGH WINDS WILL TURN TO THE SOUTH AND
SOUTHWEST DURING THE AFTERNOON...BUT WILL NOT SUBSTANTIALLY
INCREASE IN STRENGTH UNTIL A DRY ARCTIC FRONT BLASTS ACROSS THE
WATERS AROUND MIDNIGHT SATURDAY NIGHT. STEEPER LOW-LEVEL LAPSE
RATES AND PLUNGING AIR TEMPERATURES WILL PROMOTE WIND GUSTS NEAR
OR ABOVE 25 KNOTS AT TIMES...AND WE MAY NEED A SMALL CRAFT
ADVISORY FOR THIS PERIOD IN LATER FORECASTS. STRONGER WINDS WILL
DIMINISH SUNDAY BY LATE MORNING...BUT A SECONDARY SURGE OF COLD
AIR SUNDAY NIGHT WILL AGAIN INCREASE WIND SPEEDS TO 15-20 KT. WITH
GENERALLY OFFSHORE WIND TRAJECTORIES DURING THE WEEKEND SEAS
SHOULD REMAIN BELOW 4-5 FT WITHIN 20 MILES OF SHORE.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 300 PM FRIDAY...JUST A TAD FRISKY IN N WINDS EARLY MONDAY AS
THE LEADING EDGE OF HIGH PRESSURE BARGES INTO THE REGION. THIS
COULD RESULT IN 3-4 FOOT SEAS DAYBREAK MONDAY AND PERHAPS NEAR 5
FT AT FRYING PAN SHOALS. FOLLOWING THIS BRIEF SURGE...LOVELY
BOATING CONDITIONS ON TAP LATER MONDAY AND THROUGH TUESDAY...AS
THE HIGH PRESSURE CELL PASSES LAZILY OVER THE COASTAL CAROLINAS.
THE HIGH WILL SLIP OFFSHORE SOMETIME TUESDAY...ALLOWING WINDS TO
VEER TO A LIGHT SW DIRECTION BY TUESDAY AFTERNOON. LOWER PRESSURE
GRADUALLY ORGANIZING OUT OF THE GULF COASTS STATES WILL INTERACT
WITH HIGH PRESSURE OFFSHORE TO INSTIGATE MODERATE SW WINDS OF 10
TO 15 KNOTS ON WEDNESDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR AMZ254-
256.
SMALL CRAFT ADVISORY UNTIL 8 PM EST THIS EVENING FOR AMZ250-
252.
&&
$$
NEAR TERM...RGZ
SHORT TERM...TRA
LONG TERM...MJC
AVIATION...DL
FORECAST. PREVIOUS FORECAST DISCUSSION FOLLOWS:
LIGHT NORTHWEST FLOW SUN WILL INCREASE TO 15 TO 20 KT SUN NIGHT
WITH ARRIVAL OF COLD SURGE. PERIOD OF INCREASED WINDS IS BRIEF AND
DOES NOT LOOK LIKE HEADLINES WILL BE WARRANTED. SURFACE HIGH
BUILDS INTO FROM THE WEST MON WITH LIGHT NORTHERLY FLOW BECOMING
NORTHEAST DURING THE AFTERNOON. CENTER OF HIGH SHIFTS OFFSHORE
EARLY TUE WITH LIGHT RETURN FLOW DEVELOPING. OTHER THAN WITH THE
COLD SURGE SUN NIGHT WINDS WILL BE 10 KT OR LESS THROUGH THE
PERIOD. SEAS WILL RUN 2 TO 3 FT WITH THE EXCEPTION OF SUN NIGHT
WHEN SEAS NEAR 20 NM MAY APPROACH 4 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR AMZ254-
256.
SMALL CRAFT ADVISORY UNTIL 8 PM EST THIS EVENING FOR AMZ250-
252.
&&
$$
NEAR TERM...RGZ
SHORT TERM...SHK
LONG TERM...III
AVIATION...DL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1221 PM EST FRI JAN 27 2012
.SYNOPSIS...
A COLD FRONT WILL TRACK ACROSS THE REGION TODAY. FAIR WEATHER
RETURNS BY TONIGHT THROUGH THE WEEKEND AS HIGH PRESSURE SETTLES OVER
THE CAROLINAS.
&&
.NEAR TERM /TODAY THROUGH SATURDAY/...
AS OF 915 AM FRIDAY...
THE LATEST SURFACE ANALYSIS SHOWED A PREFRONTAL TROUGH MOVING EAST
ACROSS CENTRAL NORTH CAROLINA...WITH A COLD FRONT MOVING INTO THE
FOOTHILLS OF NORTH CAROLINA TOWARD THE YADKIN RIVER. AMDAR SOUNDINGS
FROM 12Z TO 13Z IN VICINITY OF BOTH KGSO AND KRDU SHOWED A
CONDITIONALLY UNSTABLE AIR MASS WITH LAPSE RATES THROUGH 500MB NEAR
THE MOIST ADIABAT. DESPITE STRONG WINDS...NEAR 60KT IN PLACES...ON
THE KRAX AND TRDU RADARS...VERY MODEST INSTABILITY...VERY LOW IF ANY
DOWNDRAFT CAPE...AND THE TIME OF DAY RESULTED IN WIND GUSTS AT THEIR
HIGHEST ON OBSERVATIONS VIEWED TO THIS POINT AT OR JUST ABOVE 40
MPH. THE SPC MESOANALYSIS HAS STARTED TO SHOW INCREASING MIXED-LAYER
CAPE IN THE LOWEST 100MB TOWARD THE COAST...BUT IT APPEARS THE
THREAT OF ANY SEVERE WEATHER SHOULD NOW BE EAST OF CENTRAL NORTH
CAROLINA.
FOR THE REST OF THE DAY...THE CONDITIONALLY UNSTABLE AIR MASS WILL
CONTINUE UNTIL THE FRONT CLEARS DURING THE AFTERNOON. GIVEN THE
AVAILABLE LAPSE RATES AND MOISTURE...AND GOOD SYNOPTIC LIFT WITH THE
FRONT AND THE MID-LEVEL TROUGH...ALONG WITH A 120KT 300MB JET MOVING
EAST...EXPECT AT LEAST SCATTERED SHOWERS ASSOCIATED WITH THE FRONT.
NAM...RUC...AND HRRR WRF GUIDANCE ALL NOTE THIS...BUT SUBSIDENCE
BEHIND THE FRONT SHOULD RESULT IN RAPIDLY FALLING CHANCES FOR
SHOWERS BY ABOUT 21Z TOWARD INTERSTATE 95. BY 00Z...WITH GOOD 850MB
SUBSIDENCE AND PRECIPITABLE WATER VALUES APPROACHING A HALF-INCH OR
LESS...CHANCES FOR SHOWERS BY DUSK ARE BELOW SLIGHT CHANCE. STILL
THE POTENTIAL FOR WIND GUSTS FROM 30 TO 40 MPH THIS AFTERNOON BASED
ON THE BOUNDARY LAYER LAPSE RATES AND WIND FORECAST BY THE 06Z NAM
BUFR SOUNDINGS...WITH WINDS DIMINISHING QUICKLY LATE AS THE GRADIENT
SLACKENS AND NIGHTTIME APPROACHES. WILL REVISIT TEMPERATURES DURING
THE LATE MORNING BASED UPON THE LATEST TRENDS AS THE FRONT PASSES...
WITH THE CURRENT FORECAST ABOVE THE MOS GUIDANCE.
TONIGHT AND SATURDAY...CONDITIONS SHOULD BE MOSTLY CLEAR. CHILLY
TONIGHT WITH LOWS IN THE MID 30S. HIGHS SATURDAY IN THE LOWER TO MID
60S WITH HIGH PRESSURE DOMINATING.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...
THIS TIME FRAME WILL FEATURE A COUPLE UPPER LEVEL DISTURBANCES...THE
FIRST ONE MOVING ACROSS THE REGION LATE SATURDAY AND THE NEXT ONE
LATE SUNDAY. BOTH OF THESE CLIPPER SYSTEMS WILL PUSH COLD FRONTS AND
REINFORCING SHOTS OF COOLER AIR INTO THE AREA. HOWEVER...DUE TO THE
LACK OF MOISTURE WITH BOTH OF THE SYSTEMS...AM EXPECTING THE FRONTAL
PASSAGES TO BE DRY. HIGH TEMPS ON SUNDAY WILL RETURN TO NEAR
SEASONABLE VALUES...GENERALLY UPPER 40S TO LOWER 50S. OVERNIGHT LOWS
ON SATURDAY NIGHT WILL BE IN THE LOW TO MID 30S...WITH SLIGHTLY
COOLER TEMPS EXPECTED BY SUNDAY NIGHT...GENERALLY THE UPPER 20S TO
LOWER 30S.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 AM FRIDAY...
A WARMING TREND WILL ENSUE DURING THE LONG TERM PERIOD. MODELS ARE
IN GOOD AGREEMENT THAT ZONAL FLOW WILL ENCOMPASS MUCH OF THE CONUS
BY THE BEGINNING OF THE WORK WEEK...WHILE AT THE SURFACE...HIGH
PRESSURE WILL PROGRESS ACROSS THE SOUTHEAST AND EVENTUALLY MOVE
OFFSHORE BY THE MIDDLE OF THE WEEK. AS A RESULT...SOUTHERLY FLOW
WILL RETURN TO THE REGION BY EARLY TUESDAY. THIS IN TURN WILL ALLOW
OUR TEMPS TO MODERATE AND AFTER NEAR SEASONABLE HIGHS ON MONDAY
(UPPER 40 TO LOW 50S)...MAX TEMPS WILL RISE WELL INTO THE 60S AGAIN
BY WEDNESDAY.
OUR NEXT SYSTEM IS EXPECTED TO IMPACT THE AREA SOMETIME MID TO LATE
WEEK...HOWEVER THERE IS LITTLE RUN TO RUN CONSISTENCY...AS WELL AS
SIGNIFICANT DISCREPANCIES BETWEEN THE MODELS. THEREFORE...WILL
MAINTAIN FORECAST CONSISTENCY AND GO NO HIGHER THAN SLIGHT CHANCE
POPS FOR THE LATE WEDNESDAY/THURSDAY TIME FRAME.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 1220 PM FRIDAY...
A COLD FRONT MOVING THROUGH CENTRAL NORTH CAROLINA WILL BE EAST OF
INTERSTATE 95 BY AROUND 21Z. LOCAL MVFR CONDITIONS IN SHOWERS WITH
THE FRONT WILL END AS WELL...LEAVING PRIMARY HAZARD BEHIND THE FRONT
THIS AFTERNOON WESTERLY WIND GUSTS TO AROUND 30KT. GRADIENT
DIMINISHES QUICKLY LATE THIS AFTERNOON AND TONIGHT RESULTING IN
LIGHTER WINDS...VEERING QUICKLY TO SOUTH AND SOUTHWEST AROUND
SUNRISE SATURDAY. UNDER VFR CONDITIONS SATURDAY WITH POSSIBLY SOME
CU DEVELOPING FROM ABOUT 3000FT TO 3500FT...EXPECT A FEW SOUTHWEST
WIND GUSTS TO AROUND 15KT WITH MIXING DURING THE MORNING.
BEYOND THE 18Z VALID TAF PERIOD...HIGH PROBABILITY OF VFR CONDITIONS
THROUGH THE WEEKEND...CONTINUING INTO TUESDAY. CHANCES INCREASE
FOR LATE NIGHT AND MORNING LOW CLOUDS TUESDAY NIGHT INTO WEDNESDAY.
CHANCES FOR SHOWERS START TO INCREASE AS HIGH PRESSURE MOVES AWAY
FROM CENTRAL NORTH CAROLINA JUST BEYOND THE END OF THIS OUTLOOK
PERIOD.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SEC
NEAR TERM...DJF/BADGETT
SHORT TERM...KRR
LONG TERM...KRR
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
917 AM EST FRI JAN 27 2012
.SYNOPSIS...
A COLD FRONT WILL TRACK ACROSS THE REGION TODAY. FAIR WEATHER
RETURNS BY TONIGHT THROUGH THE WEEKEND AS HIGH PRESSURE SETTLES OVER
THE CAROLINAS.
&&
.NEAR TERM /TODAY THROUGH SATURDAY/...
AS OF 915 AM FRIDAY...
THE LATEST SURFACE ANALYSIS SHOWED A PREFRONTAL TROUGH MOVING EAST
ACROSS CENTRAL NORTH CAROLINA...WITH A COLD FRONT MOVING INTO THE
FOOTHILLS OF NORTH CAROLINA TOWARD THE YADKIN RIVER. AMDAR SOUNDINGS
FROM 12Z TO 13Z IN VICINITY OF BOTH KGSO AND KRDU SHOWED A
CONDITIONALLY UNSTABLE AIR MASS WITH LAPSE RATES THROUGH 500MB NEAR
THE MOIST ADIABAT. DESPITE STRONG WINDS...NEAR 60KT IN PLACES...ON
THE KRAX AND TRDU RADARS...VERY MODEST INSTABILITY...VERY LOW IF ANY
DOWNDRAFT CAPE...AND THE TIME OF DAY RESULTED IN WIND GUSTS AT THEIR
HIGHEST ON OBSERVATIONS VIEWED TO THIS POINT AT OR JUST ABOVE 40
MPH. THE SPC MESOANALYSIS HAS STARTED TO SHOW INCREASING MIXED-LAYER
CAPE IN THE LOWEST 100MB TOWARD THE COAST...BUT IT APPEARS THE
THREAT OF ANY SEVERE WEATHER SHOULD NOW BE EAST OF CENTRAL NORTH
CAROLINA.
FOR THE REST OF THE DAY...THE CONDITIONALLY UNSTABLE AIR MASS WILL
CONTINUE UNTIL THE FRONT CLEARS DURING THE AFTERNOON. GIVEN THE
AVAILABLE LAPSE RATES AND MOISTURE...AND GOOD SYNOPTIC LIFT WITH THE
FRONT AND THE MID-LEVEL TROUGH...ALONG WITH A 120KT 300MB JET MOVING
EAST...EXPECT AT LEAST SCATTERED SHOWERS ASSOCIATED WITH THE FRONT.
NAM...RUC...AND HRRR WRF GUIDANCE ALL NOTE THIS...BUT SUBSIDENCE
BEHIND THE FRONT SHOULD RESULT IN RAPIDLY FALLING CHANCES FOR
SHOWERS BY ABOUT 21Z TOWARD INTERSTATE 95. BY 00Z...WITH GOOD 850MB
SUBSIDENCE AND PRECIPITABLE WATER VALUES APPROACHING A HALF-INCH OR
LESS...CHANCES FOR SHOWERS BY DUSK ARE BELOW SLIGHT CHANCE. STILL
THE POTENTIAL FOR WIND GUSTS FROM 30 TO 40 MPH THIS AFTERNOON BASED
ON THE BOUNDARY LAYER LAPSE RATES AND WIND FORECAST BY THE 06Z NAM
BUFR SOUNDINGS...WITH WINDS DIMINISHING QUICKLY LATE AS THE GRADIENT
SLACKENS AND NIGHTTIME APPROACHES. WILL REVISIT TEMPERATURES DURING
THE LATE MORNING BASED UPON THE LATEST TRENDS AS THE FRONT PASSES...
WITH THE CURRENT FORECAST ABOVE THE MOS GUIDANCE.
TONIGHT AND SATURDAY...CONDITIONS SHOULD BE MOSTLY CLEAR. CHILLY
TONIGHT WITH LOWS IN THE MID 30S. HIGHS SATURDAY IN THE LOWER TO MID
60S WITH HIGH PRESSURE DOMINATING.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...
THIS TIME FRAME WILL FEATURE A COUPLE UPPER LEVEL DISTURBANCES...THE
FIRST ONE MOVING ACROSS THE REGION LATE SATURDAY AND THE NEXT ONE
LATE SUNDAY. BOTH OF THESE CLIPPER SYSTEMS WILL PUSH COLD FRONTS AND
REINFORCING SHOTS OF COOLER AIR INTO THE AREA. HOWEVER...DUE TO THE
LACK OF MOISTURE WITH BOTH OF THE SYSTEMS...AM EXPECTING THE FRONTAL
PASSAGES TO BE DRY. HIGH TEMPS ON SUNDAY WILL RETURN TO NEAR
SEASONABLE VALUES...GENERALLY UPPER 40S TO LOWER 50S. OVERNIGHT LOWS
ON SATURDAY NIGHT WILL BE IN THE LOW TO MID 30S...WITH SLIGHTLY
COOLER TEMPS EXPECTED BY SUNDAY NIGHT...GENERALLY THE UPPER 20S TO
LOWER 30S.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 AM FRIDAY...
A WARMING TREND WILL ENSUE DURING THE LONG TERM PERIOD. MODELS ARE
IN GOOD AGREEMENT THAT ZONAL FLOW WILL ENCOMPASS MUCH OF THE CONUS
BY THE BEGINNING OF THE WORK WEEK...WHILE AT THE SURFACE...HIGH
PRESSURE WILL PROGRESS ACROSS THE SOUTHEAST AND EVENTUALLY MOVE
OFFSHORE BY THE MIDDLE OF THE WEEK. AS A RESULT...SOUTHERLY FLOW
WILL RETURN TO THE REGION BY EARLY TUESDAY. THIS IN TURN WILL ALLOW
OUR TEMPS TO MODERATE AND AFTER NEAR SEASONABLE HIGHS ON MONDAY
(UPPER 40 TO LOW 50S)...MAX TEMPS WILL RISE WELL INTO THE 60S AGAIN
BY WEDNESDAY.
OUR NEXT SYSTEM IS EXPECTED TO IMPACT THE AREA SOMETIME MID TO LATE
WEEK...HOWEVER THERE IS LITTLE RUN TO RUN CONSISTENCY...AS WELL AS
SIGNIFICANT DISCREPANCIES BETWEEN THE MODELS. THEREFORE...WILL
MAINTAIN FORECAST CONSISTENCY AND GO NO HIGHER THAN SLIGHT CHANCE
POPS FOR THE LATE WEDNESDAY/THURSDAY TIME FRAME.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
AS OF 915 AM FRIDAY...
24-HR TAF PERIOD:
A COLD FRONT WILL MOVE THROUGH THE REGION TODAY. A BAND OF
SHOWERS WITH BRIEF GUSTY WINDS TO 35KT AND HEAVY RAIN FOR 20 TO 30
MINUTES WILL ACCOMPANY THE BAND. EXPECT THE FRONT AND ANY
LINGERING SHOWERS AND ASSOCIATED LOWER CIGS/VSBYS TO BECOME VFR
CIGS/VSBYS BY AFTERNOON...WITH SCATTERED SHOWERS ACCOMPANYING THE
MAIN FRONT. WINDS WILL SHIFT TO THE WEST AT 15-25KT WITH GUSTS TO
30KT BEHIND THE FRONT...AND CONTINUE THROUGH THE DAY...DIMINISHING
QUICKLY LATE TODAY WITH THE THREAT OF SHOWERS ENDING LAST TOWARD
KRWI AROUND 21Z.
LOOKING AHEAD:
WINDS WILL QUICKLY WEAKEN AND BECOME LIGHT/VARIABLE BY OR SHORTLY
AFTER SUNSET FRIDAY NIGHT AS HIGH PRESSURE BUILDS OVER THE AREA FROM
THE WEST. THERE IS RELATIVELY HIGH CONFIDENCE THAT DRY/VFR
CONDITIONS WILL RULE FRIDAY NIGHT THROUGH EARLY NEXT WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SEC
NEAR TERM...DJF/BADGETT
SHORT TERM...KRR
LONG TERM...KRR
AVIATION...DJF/BADGETT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1245 AM EST FRI JAN 27 2012
.SYNOPSIS...
AN UPPER LEVEL TROUGH WILL SWEEP ACROSS THE REGION THIS MORNING. THE
ACCOMPANYING COLD FRONT WILL BE ACCOMPANIED BY A BAND OF SHOWERS AND
ISOLATED THUNDERSTORMS. HIGH PRESSURE WILL FOLLOW THIS AFTERNOON
INTO THE WEEKEND.
&&
.NEAR TERM /TODAY THROUGH FRIDAY/...
AS OF 1030 PM THURSDAY...
TONIGHT: A HIGH SHEAR AND LOW -- BUT HIGHER THAN RECENT NON-EVENTS
CAPE -- SEVERE WEATHER THREAT REMAINS FOR LATE TONIGHT INTO EARLY
FRIDAY.
AT 10 PM...A DEEPENING...SUB-1000 MB SURFACE CYCLONE WAS LOCATED
OVER CENTRAL KY...WITH A TRAILING COLD FRONT THAT STRETCHED SOUTH
SOUTHWESTWARD THROUGH CENTRAL AL. A SEPARATE FRONTAL ZONE STRETCHED
ALONG THE IMMEDIATE LEE OF THE APPALACHIANS FROM GA TO VA...WHICH IS
BEING ENHANCED BY A LONG-LIVED AND NOW SUB-SEVERE PRE-FRONTAL SQUALL
LINE THAT STRETCHED FROM THE WESTERN CAROLINAS...TO EAST-CENTRAL
GA...TO THE EASTERN GOM...WELL AHEAD OF THE PRIMARY SURFACE COLD.
MEANWHILE ALOFT...WV IMAGERY AND RAOB DATA INDICATE THE FORMER
CLOSED MID-UPPER LOW HAS OPENED OVER THE WESTERN TN VALLEY AND
BECOME EMBEDDED IN A PHASED FULL-LATITUDE UPPER TROUGH THAT SPANNED
THE LOWER 48 FROM ONTARIO TO MEXICO. THIS WAVE WILL ACCELERATE WEST
OF THE APPALACHIANS WITHIN AN OBSERVED 130 KT SOUTHWESTERLY UPPER
JET TONIGHT...WHILE A NORTHERN STREAM WAVE AND ASSOCIATED MID LEVEL
COLD POOL/CAA WILL CONTINUE TO AMPLIFY SHARPLY INTO CENTRAL MS/AL
BEFORE IT TOO ACCELERATES NORTHEASTWARD...ACROSS THE CAROLINAS EARLY
FRI. LARGE SCALE FORCING FOR ASCENT...CHARACTERIZED BY 00Z OBSERVED
MID-UPPER HEIGHT FALLS AROUND 150 METERS FROM KBNA TO KJAN...WILL
ACCORDINGLY STEADILY INCREASE EAST OF THE APPALACHIANS THROUGH THE
LATE-MORNING HOURS ON FRI. A SIGNIFICANT LOW LEVEL ACCELERATION WILL
ACCOMPANY THE STRONG MID-UPPER FORCING...AND RESULT IN THE FORECAST
DEVELOPMENT OF A 50-60 KT 925 MB JET THROUGH THE CENTRAL AND EASTERN
CAROLINAS AFTER 06Z...WHICH WILL FURTHER ENHANCE ALREADY ADEQUATE
LOW LEVEL SHEAR AND PROMOTE INCREASINGLY BREEZY CONDITIONS OVER THE
CAROLINAS. INDEED...UPSTREAM VWP DATA FROM KCAE AND KGSP INDICATE A
100 PERCENT INCREASE IN THIS LLJ...FROM 20 KTS JUST A FEW HOURS AGO
TO 40-50 KTS AT 10 PM.
SINCE LARGE-SCALE FORCING AND LOW-DEEP SHEAR WILL BE PLENTIFUL...THE
TWO WILDCARDS ARE 1) HOW THE PRE-FRONTAL SQUALL LINE MAY ALTER
VERTICAL MOTION ON THE MESOSCALE OVER OUR REGION...AND 2) HOW MUCH
(BOUNDARY LAYER-BASED) INSTABILITY MATERIALIZES - THE LATTER OF
WHICH SEEMS MORE STRAIGHTFORWARD. NAM/WRF AND RUC SOLUTIONS INDICATE
THE DEVELOPMENT OF 300-500 J/KG AFTER 4 AM...AND THIS LOOKS
REASONABLE GIVEN CURRENT SURFACE OBSERVATIONAL DATA THAT INDICATES
TEMPERATURES WILL HOLD STEADY OR RISE SLIGHTLY THROUGH THE LOWER TO
MIDDLE 60S...WITH DEWPOINTS FOLLOWING A SIMILAR TENDENCY AND ABOUT
2-4 DEGREES LOWER. THE GFS ON THE OTHER HAND IS TOO COOL AND DRY IN
THE BOUNDARY LAYER AND ACCORDINGLY DEPICTS LITTLE TO NO CAPE. HOW
THE SQUALL LINE AFFECTS THE DOWNSTREAM ENVIRONMENT REMAINS MORE
PROBLEMATIC AND MAY NOT BECOME FULLY EVIDENT UNTIL A POSSIBLE SEVERE
WEATHER EVENT IS UPON US...BUT THE MAGNITUDE OF APPROACHING
LARGER-SCALE FORCING MAY RENDER ANY PRECEDING MESOSCALE EFFECTS
MOOT.
WE ACCORDINGLY EXPECT AN UPSWING IN CONVECTIVE INTENSITY LATE
TONIGHT...PERHAPS IN TWO ROUNDS WITH FIRST THE PRE-FRONTAL SQUALL
LINE...FOLLOWED BY PROBABLY STRONGER DEVELOPMENT UPSTREAM OVER AL/GA
THAT IS FOCUSED BENEATH THE MORE CONCENTRATED FORCING AND CAA ALOFT.
THE COMBINATION OF SHEAR (AND SOUTHWESTERLY DEEP SHEAR VECTORS) AND
ALBEIT WEAK INSTABILITY WILL SUPPORT A CONDITIONAL PROBABILITY OF A
FEW LOW-TOPPED SUPERCELLS AND BOWS WITH AN ATTENDING THREAT OF
DAMAGING WINDS AND ISOLATED TORNADOES...MAINLY BETWEEN 4 AND 10 AM.
WHILE THIS THREAT WILL EXIST ACROSS ALL OF CENTRAL NC...THERE MAY BE
A RELATIVE MAXIMUM TORNADIC THREAT OVER THE FOOTHILLS AND WESTERN
PIEDMONT...INVOF THE AFOREMENTIONED LEE OF THE APPALACHIANS FRONTAL
ZONE. INTERESTINGLY...RECENT HRRR RUNS INDICATE VERY LITTLE UPSTREAM
DEVELOPMENT...AND INSTEAD A RE-INVIGORATION OF THE PRE-FRONTAL
CONVECTION OVER THE EASTERN TWO THIRDS OF THE CWFA. -MWS
FRI AFTERNOON AND EVENING: THE 12Z RUN ALSO SHOWS SOME POTENTIAL FOR
A LINE OF SHORT-LIVED LIGHT SHOWERS TO DEVELOP IN THE EARLY EVENING
HOURS. WINDS ARE EXPECTED TO BE SUSTAINED AT 15-20 KTS...GUSTING TO
BETWEEN 25 AND 30 KTS. HIGHS TOMORROW ARE EXPECTED TO BE IN THE LOW
60S ACROSS THE NORTHWEST TO NEAR 70 IN THE SOUTHEAST. -KMC
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 230 PM THURSDAY...
MODIFIED SOUTHERN STREAM SFC HIGH OVER THE GULF COAST STATES WILL
BRIEFLY BUILD INTO THE AREA FRIDAY NIGHT THROUGH EARLY SATURDAY.
A PAIR OF MOISTURE-DEPRIVED CLIPPER LIKE DISTURBANCES WILL THEN
DRIVE A SERIES OF DRY COLD FRONTAL PASSAGES SOUTHEASTWARD THROUGH
THE AREA LATE SATURDAY AFTERNOON AND THEN AGAIN SUNDAY
AFTERNOON/EVENING. EACH PASSING FRONT WILL BRING MARGINALLY COOLER
AIR INTO THE REGION.
THUS..EXPECT ANOTHER MILD DAY ON SATURDAY FEATURING HIGHS IN THE
UPPER 50S TO LOWER 60S...WITH HIGHS TEMPERATURES BRIEFLY FALLING
BACK TO MORE SEASONABLE READINGS OF UPPER 40S TO LOWER 50S SUNDAY
AND MONDAY. LOWS FRIDAY NIGHT IN THE MID TO UPPER 30S...WITH NEAR
FREEZING MINS SATURDAY NIGHT AND NEAR 30 READINGS SUNDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 230 PM WEDNESDAY...
UNSEASONABLY MILD TEMPERATURES TO CONTINUE NEXT WEEK.
MEDIUM RANGE MODELS ARE IN GOOD AGREEMENT THAT THE LARGE SCALE FLOW
OVER THE CONUS WILL QUICKLY FLATTEN/ZONAL OUT TO START THE WORK WEEK
WITH TEMPERATURES MODERATING AS SURFACE HIGH SHIFTS OFF THE
SOUTHEAST COAST. THE RESULTANT SOUTHERLY RETURN FLOW WILL MAKE 60
DEGREE READINGS PAR FOR THE COURSE BY WEDNESDAY WITH MIN
TEMPERATURES ONLY GETTING DOWN INTO THE 40S.
THERE REMAINS LITTLE RUN-TO-RUN CONSISTENCY WRT TO THE
DEVELOPMENT/AMPLITUDE OF A LOW AMPLITUDE SHORTWAVE TROUGH BY THE MID
TO LATE WEEK TIME FRAME. GIVEN THE ZONAL FLOW ALOFT THERE REMAINS
QUESTIONS IF THERE WILL BE ENOUGH MOISTURE TRANSPORT...AND THUS WILL
CARRY ONLY A SLIGHT CHANCE POP FOR NOW.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 1245 AM FRIDAY...
24-HR TAF PERIOD:
A COLD FRONT WILL MOVE THROUGH THE REGION BETWEEN 500 AM AND 900 AM
IN THE WEST... AND 700 AM AND 1000 AM IN THE EAST. GUSTY SSW WINDS
TO 30KT WILL OCCUR OUT AHEAD OF THE FRONT. A BAND OF SHOWERS AND
POTENTIALLY ISOLATED THUNDERSTORMS IS EXPECTED TO AFFECT THE REGION
WITH THE FRONTAL PASSAGE. IFR CIGS CAN GENERALLY BE EXPECTED... WITH
VFR VSBYS EXCEPT DROPPING TO IFR VSBYS WITH THE SHOWERS.
EXPECT THE FRONT AND ANY LINGERING SHOWERS AND ASSOCIATED LOWER
CIGS/VSBYS TO BECOME VFR CIGS/VSBYS BY LATE MORNING OR EARLY
AFTERNOON. WINDS WILL SHIFT TO THE WEST AT 15-25KT BEHIND THE
FRONT... AND CONTINUE THROUGH THE DAY.
LOOKING AHEAD:
WINDS WILL QUICKLY WEAKEN AND BECOME LIGHT/VARIABLE BY OR SHORTLY
AFTER SUNSET FRIDAY NIGHT AS HIGH PRESSURE BUILDS OVER THE AREA FROM
THE WEST. THERE IS RELATIVELY HIGH CONFIDENCE THAT DRY/VFR
CONDITIONS WILL RULE FRIDAY NIGHT THROUGH EARLY NEXT WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS/KC
SHORT TERM...CBL
LONG TERM...CBL
AVIATION...BADGETT/BSD
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
135 AM EST FRI JAN 27 2012
.SYNOPSIS...
A COLD FRONT WILL PUSH ACROSS THE REGION THIS MORNING. ANOTHER
LOW PRESSURE SYSTEM COMING OUT OF THE NORTHERN PLAINS AND INTO THE
GREAT LAKES WILL BRING A SECOND COLD FRONT THROUGH THE AREA ON
SATURDAY. HIGH PRESSURE WILL BE OVER THE EASTERN UNITED STATES
SUNDAY AND MONDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 116 AM EST FRIDAY...
HAVE TWO MAIN AREAS OF CONCERN. SHOWERS MOVING ALONG THE BLUE
RIDGE ARE BRINGING THE STRONG 8H WINDS DOWN WITH GUSTS OVER 45 MPH
BEING REPORTED WITH SOME OF THE SHOWERS. CONTEMPLATED A WIND
ADVISORY BUT THE TIMING OF THE WINDS WILL BE MAINLY LESS THAN AN
HOUR OR TWO WITH SHOWERS...SO OPTED TO GO WITH SPECIAL WX
STATEMENTS TO COVER THE STRONGER GUSTS. ONE THING OF NOTE IS THE
DEEP CONVECTION IN THE NE GULF OF MEXICO WHICH IS ROBBING THE
MOISTURE INFLOW INTO OUR AREA...WHICH WILL CUT DOWN ON QPF SOME.
WITH THE COLD FRONT/SFC LOW IS ANOTHER STRONGER LINE OF CONVECTION
FORMING AND HAVE AN SPS COVERING THIS AND WILL BE MONITORED FOR
POTENTIAL WARNINGS. THE LATEST RUC SHOWS TWO SPEED MAXES AT
8H...ONE MOVING ACROSS THE BLUE RIDGE AND THE OTHER UP INTO
WV. THIS LOW LVL JET WILL BE EAST OF THE MTNS BEFORE DAWN IN
ADDITION TO THE COLD FRONT. KEPT HIGHEST POPS ALONG AND WEST OF
THE BLUE RIDGE EARLY THEN TRANSITION TO THE EAST THROUGH DAWN. DRY
SLOT ON WV LOOP WORKING INTO THE SMOKYS WILL SURGE INTO OUR MTNS
BY 12Z TODAY AND NAM/CMC SHOWING CLEARING BUT GFS HOLDING ONTO
MORE CLOUDS. LOOKING AT IR SAT...THE CLEARING LINE IS LAGGING BACK
INTO NRN MS/WRN TN.
ON FRIDAY...ONCE THE FRONT GOES THROUGH MODELS WERE SHOWING RAPID
DRYING...PARTLY DUE TO STRONG DOWNSLOPING EAST OF THE BLUE RIDGE.
HOWEVER THE SAME STRONG NORTHWEST SURFACE AND LOW LEVEL WIND WILL
HOLD CLOUDS IN THE MOUNTAINS FOR MUCH OF THE MORNING. HAVE ENDED
SHOWERS A BIT FASTER IN THE EAST AND DIMINISHED THE CHANCE OF
PRECIPITATION IN THE WEST BY THE END OF THE DAY.
MODELS WERE SHOWING +8 TO +10 MB/3HR PRESSURE RISES AND MODEST COLD
AIR ADVECTION BEHIND THE FRONT ON FRIDAY MORNING. ONCE MIXING BEGINS
EXPECT GUSTY WINDS TO CONTINUE THROUGH AT LEAST MID AFTERNOON. NO
ADVISORY PLANNED AT THIS TIME. PEAK GUSTS LOOK TO BE JUST UNDER 45
MPH.
FOR LOWS TONIGHT...SINCE THE SURFACE DEW POINTS CONTINUE TO
RISE...DO NOT EXPECT MUCH OF A FALL IN TEMPERATURES. WILL GO ABOVE
GUIDANCE FOR MINIMUM TEMPERATURE. 850 MB TEMPERATURES BEHIND THE
FRONT DROP IN THE MORNING...SO HOURLY TEMPERATURE TREND WILL
MOSTLY LIKELY BE NON DIURNAL ON FRIDAY.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
AS OF 300 PM EST THURSDAY...
TWO FAST MOVING CLIPPERS WILL THROW CLOUDS AND COLDER WEATHER OUR
WAY FOR SUNDAY. SOME RAIN/SNOW SHOWERS AND SPRINKLES/FLURRIES
WILL BE POSSIBLE WITH BOTH OF THESE...BUT MORE SO WITH THE SECOND
CLIPPER PASSING THROUGH SUNDAY AFTERNOON...WHICH MAY TAKE A MORE
SOUTHERLY TRACK WITH COLDER AIR IN PLACE. DECENT WIND GUSTS WITH
EVAP COOLING WILL ACCOMPANY ANY VIRGA WHICH CROSSES THE RIDGES. THE
DOWNSLOPE WARMING WILL CREATE STEEP LAPSE RATES...NEARLY DRY
ADIABATIC AND DEEP MIXING TO H7 AS SHOWN ON NAM/GFS BUFKIT PROFILES.
MOMENTUM TRANSFER AT THE TOP OF THE MIXED LAYER IS 60 KTS IN THE NEW
RIVER VALLEY NEAR 7P SUNDAY...AND THE NAM IS ACTUALLY A LITTLE BIT
WEAKER. THIS IS PROBABLY BECAUSE THE OP GFS IS THE MOST AMPLIFIED
SOLUTION. NONETHELESS...CAN`T RULE OUT ADVISORY GUSTS WITH THIS
INVERTED V PROFILE ATOP THE RIDGES OF THE WESTERN HALF OF THE CWA.
A QUICK BURST OF SNOW SHOWERS SUNDAY NIGHT COULD PUT DOWN A QUICK
COATING OF SNOW IN WESTERN GREENBRIER COUNTY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 200 PM EST THURSDAY...
WILL BE LOOKING AT A SERIES OF WEAK COLD FRONTS PASSING ACROSS OUR
AREA DURING THE EXTENDED PERIOD...BUT DO NOT EXPECT ANY HIGH WEATHER
IMPACTS TO OUR AREA THROUGH THE FIRST FEW DAYS OF FEBRUARY. HIGH
PRESSURE WILL BUILD ACROSS OUR AREA ON MONDAY IN THE WAKE OF A
DEPARTING COLD FRONT...AND WE CAN EXPECT MOSTLY CLEAR SKIES AND
LIGHT NORTHWEST WINDS. BECAUSE THE DOME OF HIGH PRESSURE BUILDING IN
IS MORE PACIFIC IN ORIGIN RATHER THAN CANADIAN...WE CAN EXPECT THE
SEASONABLE TEMPERATURES TO CONTINUE ACROSS OUR AREA...WITH OVERNIGHT
LOWS IN THE UPPER 20S TO LOW 30S...AND MONDAY AFTERNOON HIGHS
RANGING FROM THE UPPER 30S IN THE MOUNTAINS...TO THE MID TO UPPER
40S ACROSS THE PIEDMONT REGION.
HIGH PRESSURE WILL PASS EAST OF OUR AREA ON MONDAY NIGHT AND
TUESDAY...ALLOWING OUR WINDS TO BECOME SOUTHERLY AND FOR
TEMPERATURES TO ENTER A WARMING TREND. EXPECT THAT WE WILL START OUT
THE DAY WITH MOSTLY SUNNY SKIES...BUT THAT CLOUDS WILL INCREASE
DURING THE EVENING AS ANOTHER COLD FRONT APPROACHES FROM THE WEST.
SHOWER ACTIVITY WILL BEGIN TO MAKE ITS WAY INTO OUR SOUTHEAST WEST
VIRGINIA AND MOUNTAIN EMPIRE REGION COUNTIES.
THE COLD FRONT IS EXPECTED TO PUSH THROUGH OUR AREA ON WEDNESDAY
AFTERNOON. WITH LIMITED MOISTURE TO WORK WITH...THIS COLD FRONT IS
EXPECTED TO TRIGGER ONLY SPOTTY LIGHT SHOWER ACTIVITY. HIGH PRESSURE
BUILDS IN QUICKLY BEHIND THE COLD FRONT ON WEDNESDAY AFTERNOON...AND
PASSES JUST AS QUICKLY TO THE EAST OF OUR AREA BY THURSDAY MORNING.
&&
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
AS OF 1115 PM EST THURSDAY...
A COLD FRONT CONTINUES TO APPROACH THE REGION FROM EASTERN
KENTUCKY. IN ADVANCE OF IN SOUTHERLY FLOW SOUTH OF A WARM FRONT IS
INCREASING. SHOWERS ARE NUMEROUS ALONG A LINE FROM KUKF TO
KHSP...INCLUDING TAF SITES KBCB AND KROA. EXPECTING COVERAGE TO
CONTINUE TO BE GOOD IN THIS REGION HEADING INTO THE EARLY MORNING
HOURS OF FRIDAY...ALL WHILE THE PRECIPITATION MAKES PROGRESSION
EASTWARD AS WELL. THERE MAY BE AN HOUR OR TWO GAP BETWEEN THIS
PRE-FRONTAL PRECIPITATION AND LOCALLY HEAVIER PRECIPIATION THAT
ARRIVES WHEN THE FRONT MOVES THROUGH BETWEEN 10Z...5AM WEST....AND
14Z...9AM EAST. MOST AREA WILL TREND TO IFR/MVFR CIGS AND THEN
IMRPOVE BEHIND THE FRONT...ESPECIALLY IN THE EAST WHERE WINDS
WILL HAVE A STRONG DOWNSLOPE COMPONENT.
AS OF 640 PM EST THURSDAY...
CONVECTION AND MVFR CIGS HAVE BEEN SLOWER TO FILL IN THAN
PREVIOUSLY ANTICIPATED. AS SUCH...HAVE SLOWED ONSET OF PREVAILING
PRECIPITION AND LOWER CIG THRESHOLDS BY ROUGHLY TWO HOURS ACROSS
THE BOARD. OTHER ASPECTS OF EARLIER FORECAST STILL RELATIVELY ON
TRACK SAVE THE ONSET OF LLWS. THIS TOO HAS BEEN DELAYED BY AROUND
TWO HOURS AT MOST LOCATIONS.
AS OF 108 PM EST THURSDAY...
THERE WILL BE SCATTERED TO ISOLATED THUNDERSTORMS...SOME WITH
VERY GUSTY WINDS ALONG WITH THE BAND OF SHOWERS. LOW CONFIDENCE
THAT ANY INDIVIDUAL TAF SITE WILL GET A THUNDERSTORM. THE MOST
LIKELY LOCATION WOULD BE DAN SO HAVE ADDED CB CLOUD TYPE IN LATE
TONIGHT.
BOTTOM OF THE 55-65 KNOT LOW LEVEL JET JUST REACHES THE 2000 FOOT
CRITERIA FOR LLWS SO HAVE INCLUDED IN THE TAFS AHEAD OF THE FRONT
THROUGH MOST OF THE NIGHT. ONCE MIXING BEGINS IN THE MORNING
BEHIND THE FRONT GUSTS MAY REACH 30 KNOTS DUE TO STRONG PRESSURE
RISES AND MODEST COLD AIR ADVECTION.
THE STRONG NORTHWEST WINDS CLEAR OUT THE CLOUDS BEHIND THE FRONT
FRIDAY EAST OF THE BLUE RIDGE. UPSLOPE CLOUDINESS WILL LINGER IN
SE WV...WITH MVFR CIGS MUCH OF FRIDAY.
COULD SEE SOME MVFR CEILINGS ACROSS THE WV TAF SITES SATURDAY AND
SATURDAY NIGHT WITH A CLIPPER MOVING ACROSS THE REGION. OTHERWISE
SATURDAY AND SUNDAY FLIGHT CONDITIONS WILL BE VFR.
&&
.FIRE WEATHER...
WINDS WILL GUST BEHIND THE FRONT ON FRIDAY WITH GOOD DRYING EAST
OF THE BLUE RIDGE AND GUSTS UP TO 45 MPH AT HIGHER ELEVATIONS.
THERE MAY BE SOME RED FLAG CRITERIA RH AND WIND SUNDAY...HOWEVER THE
GROUND WILL PROBABLY BE STILL TOO MOIST AND FUEL STICK MOISTURES
PROBABLY WILL NOT MAKE CRITERIA. WILL MENTION IN THE FWF DISCUSSION.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/WP
NEAR TERM...AMS/DS/WP
SHORT TERM...KM
LONG TERM...NF
AVIATION...AMS/DS/WP
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
621 PM CST SAT JAN 28 2012
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE...CORRECTION LAST
SENTENCE...
.SYNOPSIS...MORE OF WHAT HAS COME TO BE THE NORM FOR THIS
WINTER...ABOVE NORMAL TEMPERATURES WITH ONLY A COUPLE MODEST PCPN
EVENTS.
UPR PATTERN CURRENTLY FEATURES MODEST TROF OVER THE N-C CONUS...
BUT FLOW WL FLATTEN BACK TO ZONAL REGIME DURING THE NEXT COUPLE
DAYS. MED RANGE MODELS AGREEDED IN GRADUALLY BUILDING SOME RIDGING
OVER WRN CANADA DURING THE LATTER PART OF THE FCST PERIOD. BUT RIDGE
NEVER SEEMS TO GET STG/SHARP ENOUGH TO FORCE A DISTINCT DOWNSTREAM
TROF OVER ERN CONUS. SO WL PROBABLY CONT WITH GENERAL WLY FLOW AND
FAIRLY HIGH UPR HGTS.
OTHER THAN A COUPLE GLANCING SHOTS OF COLDER AIR BEHIND INDIVIDUAL
WX SYSTEMS...THE FCST AREA WL PRIMARILY BE DOMINATED BY PACIFIC
AIR. THAT WL RESULT IN ABV NORMAL TEMPS. PATTERN WL SUPPORT A FEW
PCPN PRODUCING SYSTEMS...BUT NO STG STORMS IN THE OFFING.
&&
.SHORT TERM...TONIGHT AND SUNDAY.
THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW THE STATE
OF WISCONSIN LOCATED BETWEEN LOW PRESSURE OVER THE ONTARIO/QUEBEC
BORDER AND HIGH PRESSURE SITUATED OVER THE SOUTHERN PLAINS.
CYCLONIC FLOW AND THERMAL TROUGHING BETWEEN THESE FEATURES ARE
CONTRIBUTING TO A WIDESPREAD STRATO-CU FIELD STRETCHING FROM
NORTHERN MINNESOTA TO LOWER MICHIGAN. PLENTY OF SNOW SHOWER ACTIVITY
WITHIN THE COLDER CLOUD TOPS OVER NORTH-CENTRAL WISCONSIN AND THE
WESTERN UPPER PENINSULA EARLY THIS AFTERNOON. THE NEXT SHORTWAVE IS
OBSERVED PUSHING INTO NORTH DAKOTA WHICH WILL HEAD FOR THE REGION
TONIGHT. PRECIP CHANCES WITH THIS FEATURE AND CLOUD COVER ARE THE
MAIN FORECAST CONCERNS OVER THE NEXT 24 HOURS.
TONIGHT...SHORTWAVE TROUGH OVER THE DAKOTAS IS NOW EXPECTED TO TAKE
A SLIGHTLY MORE SOUTHERLY TRACK THAN PROJECTED YESTERDAY...FROM
ABOUT EASTERN SOUTH DAKOTA TO NORTHERN ILLINOIS. THOUGH THE WAVE
WILL STILL HAVE GOOD QG FORCING WITH IT...THE MORE SOUTHERLY TRACK
WILL SHIFT THE COMMA HEAD OF THE COMPACT WAVE OVER SOUTHERN
WISCONSIN RATHER THAN CENTRAL WISCONSIN. AS A RESULT...HAVE REMOVED
POPS FROM CENTRAL AND EAST-CENTRAL WISCONSIN TONIGHT.
OTHERWISE...CYCLONIC FLOW SUBTLY BROADENS OUT TONIGHT...WHICH SHOULD
ALLOW THE LOW STRATO-CU TO RETREAT TO THE NORTH. PLENTY OF FLURRY
ACTIVITY UPSTREAM WILL FORCE ME TO KEEP A MENTION OVER N-C
WISCONSIN. LOW LEVEL WINDS ARE TOO WESTERLY HOWEVER TO HAVE MUCH OF
A LAKE INFLUENCE. LOWS WILL RANGE FROM THE MIDDLE SINGLE DIGITS
ABOVE ZERO NORTH TO THE MID TEENS SOUTHEAST.
SUNDAY...MID-LEVEL CLOUDS FROM THE SHORTWAVE WILL DEPART TO THE
SOUTHEAST EARLY SUNDAY MORNING WHICH MAY LEAVE A PERIOD OF MOSTLY
SUNNY CONDITIONS OVER CENTRAL AND EAST-CENTRAL WISCONSIN TO START
THE DAY. LOW LEVEL WINDS WILL TURN BACK TO THE NORTHWEST BEHIND THE
DEPARTING WAVE. AS THIS OCCURS...COLD ADVECTION WILL RESUME WHICH
SHOULD LEAD TO ANOTHER SURGE SOUTHEAST OF THE LOW STRATO-CU LATE
MORNING INTO EARLY AFTERNOON. WINDS THEN BACK AROUND TO THE WEST MID
TO LATE AFTERNOON AS THE SURFACE RIDGE APPROACHES. SHOULD SEE THE
STRATO-CU BREAK UP SOME AS DRIER AIR PUSHES IN FROM THE WEST. HIGH
TEMPS RANGING FROM THE MID TEENS NORTH TO THE LOWER 20S SOUTHEAST.
.LONG TERM...SUN NGT THROUGH NEXT SAT. TEMPS WL PROBABLY FALL OFF
FAIRLY QUICKLY EARLY SUN NGT WITH SFC RIDGE COMING ACRS THE
AREA...BUT THEN START TO RISE AS CLDS INCR. ISENT LIFT WL SWEEP
EWD ACRS THE AREA LATE AT NGT AND MON MORNING. MODELS SEEMED A BIT
SLOWER WITH THE PCPN...SO TWEAKED TIMING BACK A BIT. TOOK THE N UP
TO LIKELIES MON MORNING. WL PROBABLY GET A COUPLE INCHES OF SNOW
ACRS THE N...AND MAYBE AN INCH OR SO IN THE S. PCPN WL PROBABLY
TAPER OFF TO FZDZ/DZ AS MIDDLE LEVEL MOISTURE GETS STRIPPED OFF TO
THE NE.
12Z RUN OF THE ECMWF BACKED OFF WITH PCPN CHCS TUE. THE OTHER
MODELS ALREADY WERE TAMER. MAY VERY WELL GET BY WITHOUT ANY PCPN
AS FCST AREA WL JUST BE IN THE WARM SECTOR OF WK CYCLONE TRACKING
ALONG THE U.S/CANADIAN BORDER. BUT DIDN/T WANT TO COMPLETELY PULL
PCPN WITH SYSTEM CROSSING THE RGN...SO SETTLED FOR TRENDING POPS
DOWN.
&&
.AVIATION...
WATER VAPOR IMAGERY SHOWS UPPER-LEVEL DISTURBANCE DIVING SOUTHEAST
TOWARD SOUTHWEST MINNESOTA EARLY THIS EVENING. SOME VERY LIGHT
SNOW SHOWER ACTIVITY BEGINNING TO BREAK OUT ACROSS CENTRAL
AND SOUTHERN MINNESOTA. HOWEVER MODEL CONSENSUS SUGGESTS LIGHT
SNOW AND SNOW SHOWER ACTIVITY ACCOMPANYING THIS DISTURBANCE SHOULD
REMAIN SOUTH OF THE FORECAST AREA OVERNIGHT.
EXPECT MAINLY MVFR CIGS GENERALLY NORTH OF I29 CORRIDOR WITH A FEW
SCATTERED FLURRIES. EXPECT MVFR CIGS TO CONTINUE ACROSS THE NORTH
OVERNIGHT WITH FLURRY ACIVITY AROUND THE RHI VICINITY UNTIL ABOUT
03Z.
GENERALLY VFR CONDITIONS SOUTH OF I29 INCLUDING GRB AND CWA
OVERNIGHT WITH SCT-BKN CIGS AOA 3KFT. AS DISTURBANCE PASSES ACROSS
SOUTHERN WISCONSIN EXPECT INCREASE IN MID-LEVEL CLDS. GUSTY WEST
WINDS THIS EVENING WILL DIMINISH BY O6Z.
WK HIGH PRESSURE BUILDS INTO THE AREA DURING THE DAY ON SUNDAY
WITH GENERALLY VFR CONDITIONS EXCEPT OCCASIONAL MFVR CIGS THROUGH
MID-DAY AROUND RHI.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
EB
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1148 AM CST FRI JAN 27 2012
.SHORT TERM...UPDATE
1041 AM CST FRI JAN 27 2012
A BAND OF LIGHT SNOW CONTINUES TO TRACK EAST ACROSS WESTERN TO
CENTRAL MINNESOTA AND NORTH CENTRAL IOWA THIS MORNING. THERE HAS
BEEN SOME LIGHT RAIN AND SLEET THAT HAS SHOWN UP ACROSS THIS
REGION DUE TO A WARM LAYER AROUND 925MB WHERE TEMPERATURES ARE
AROUND 1 TO 3C. THE 27.14Z RUC SHOWS THIS WARM LAYER COOLING
THROUGH THE AFTERNOON...SO IT DOES NOT APPEAR THAT WE SHOULD SEE A
MIX AROUND HERE THOUGH THE 27.14Z HRRR DOES HINT AT A MIX OCCURRING
IN THE MISSISSIPPI RIVER VALLEY FROM LA CROSSE UP TO WINONA.
SO FAR...THE LOWEST VISIBILITIES DUE TO SNOW HAVE BEEN ACROSS
CENTRAL MINNESOTA NORTHWEST OF THE TWIN CITIES WITH BASICALLY A 1
TO 2SM SNOW OCCURRING THROUGH SOUTHERN MINNESOTA AND NORTHERN IOWA.
BASED ON THESE CURRENT TRENDS AND WHAT THE HRRR AND OTHER
MESOSCALE MODELS ARE SHOWING...THIS WILL BE A QUICK SNOW WITH THE
HEAVIEST RATES LASTING JUST A FEW HOURS BEFORE TAPERING OFF. HAVE
BACKED OFF ON SNOWFALL AMOUNTS A TAD FOR THIS AFTERNOON AND
EVENING WITH THE HEAVIEST SNOW STILL FALLING ACROSS NORTH CENTRAL
WISCONSIN. HAVE GONE WITH A 1 TO 3 INCH BAND THERE WITH AROUND AN
INCH GOING ACROSS THE REST OF THE REGION. BASED ON THE 27.14Z
HRRR...THE BACK EDGE OF THE SNOW AND SURFACE COLD FRONT SHOULD BE
TO THE MISSISSIPPI RIVER AROUND 00Z AND THROUGH WESTERN WISCONSIN
BY 4Z. FOR NOW...HAVE KEPT SOME CHANCES GOING INTO THE OVERNIGHT
HOURS...BUT WE MAY HAVE TO TREND THOSE BACK SOME WITH THE
AFTERNOON FORECAST PACKAGE.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
316 AM CST FRI JAN 27 2012
THE NEXT CHANCE FOR SOME PRECIPITATION WILL COME SUNDAY NIGHT INTO
MONDAY. AN AREA OF LOW PRESSURE WILL BE QUICKLY MOVING ACROSS
SOUTHERN CANADA WITH A WARM FRONT EXPECTED TO LIFT NORTHEAST
THROUGH THE REGION. THE GFS IS SHOWING AROUND 4 UBAR/S OF
ISENTROPIC UP GLIDE ON THE 280K SURFACE AHEAD OF THE WARM FRONT.
NOT A LOT OF OTHER FORCING SO ONLY SOME LIGHT PRECIPITATION
EXPECTED AS THIS COMES THROUGH. FOR NOW HAVE CARRIED THE CHANCES
ALL THE WAY THROUGH MONDAY...BUT THE AFTERNOON COULD END UP DRY.
IF THE PRECIPITATION DOES EXTEND INTO THE AFTERNOON...SOME
PRECIPITATION TYPE CONCERNS WILL COME INTO PLAY AS A WARM NOSE
ALOFT DEVELOPS. SOME ADDITIONAL CHANCES FOR PRECIPITATION COME IN
FOR TUESDAY AND TUESDAY NIGHT...BUT CONFIDENCE IS NOT HIGH AS THE
ECMWF AND 27.00Z GEM SHOW A SURFACE LOW MOVING EAST/SOUTHEAST
ACROSS THE NORTHERN GREAT LAKES WHILE THE GFS BRINGS THE LOW OUT
OF THE SOUTHWEST TOWARD THE GREAT LAKES. FOR NOW HAVE STAYED WITH
THE MODEL CONSENSUS WHICH HAS 20 TO 30 PERCENT CHANCES.
&&
.AVIATION...THROUGH 18Z SATURDAY
1148 AM CST FRI JAN 27 2012
THE MAIN CONCERN AT THE TAF SITES IS WITH THE BAND OF SNOW
CURRENTLY IN CENTRAL MINNESOTA AND NORTHERN IOWA AND WHEN IT WILL
COME THROUGH THE TAF SITES. THE LEADING EDGE OF THE SNOW SHOULD BE
INTO RST BETWEEN 19 TO 20Z AND LSE BETWEEN 21 TO 22Z. VISIBILITIES
HAVE MAINLY BEEN IN THE 1 1/2SM TO 3SM RANGE THOUGH THERE HAVE
BEEN SOME BRIEF 1/4SM TO 3/4SM REPORTS OUT ACROSS SOUTHERN
MINNESOTA AND NORTHERN IOWA. CONFIDENCE WAS NOT HIGH ENOUGH AT
THIS POINT TO PUT THESE LOWER VISIBILITIES INTO THE TAFS FOR A
BRIEF PERIOD...SO HAVE LEFT THEM OUT AT THIS POINT. WITH A DECENT
AMOUNT OF DRY LOW LEVEL AIR IN PLACE...CEILINGS SHOULD REMAIN MVFR
THROUGH THIS EVENING UNTIL THE COLD FRONT COMES THROUGH WHEN THEY
SHOULD CLIMB TO VFR. WINDS WILL BE ANOTHER ISSUE WITH SOUTHWEST
WINDS GUSTING TO 20 TO 25KTS AT RST THIS AFTERNOON AHEAD OF THE
COLD FRONT AND THEN EVEN STRONGER GUSTS UP TO 30KTS OUT OF THE
WEST NORTHWEST EXPECTED AFTER THE FRONT PASSES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
316 AM CST FRI JAN 27 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM....04
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1041 AM CST FRI JAN 27 2012
.SHORT TERM...UPDATE
1041 AM CST FRI JAN 27 2012
A BAND OF LIGHT SNOW CONTINUES TO TRACK EAST ACROSS WESTERN TO
CENTRAL MINNESOTA AND NORTH CENTRAL IOWA THIS MORNING. THERE HAS
BEEN SOME LIGHT RAIN AND SLEET THAT HAS SHOWN UP ACROSS THIS
REGION DUE TO A WARM LAYER AROUND 925MB WHERE TEMPERATURES ARE
AROUND 1 TO 3C. THE 27.14Z RUC SHOWS THIS WARM LAYER COOLING
THROUGH THE AFTERNOON...SO IT DOES NOT APPEAR THAT WE SHOULD SEE A
MIX AROUND HERE THOUGH THE 27.14Z HRRR DOES HINT AT A MIX OCCURRING
IN THE MISSISSIPPI RIVER VALLEY FROM LA CROSSE UP TO WINONA.
SO FAR...THE LOWEST VISIBILITIES DUE TO SNOW HAVE BEEN ACROSS
CENTRAL MINNESOTA NORTHWEST OF THE TWIN CITIES WITH BASICALLY A 1
TO 2SM SNOW OCCURRING THROUGH SOUTHERN MINNESOTA AND NORTHERN IOWA.
BASED ON THESE CURRENT TRENDS AND WHAT THE HRRR AND OTHER
MESOSCALE MODELS ARE SHOWING...THIS WILL BE A QUICK SNOW WITH THE
HEAVIEST RATES LASTING JUST A FEW HOURS BEFORE TAPERING OFF. HAVE
BACKED OFF ON SNOWFALL AMOUNTS A TAD FOR THIS AFTERNOON AND
EVENING WITH THE HEAVIEST SNOW STILL FALLING ACROSS NORTH CENTRAL
WISCONSIN. HAVE GONE WITH A 1 TO 3 INCH BAND THERE WITH AROUND AN
INCH GOING ACROSS THE REST OF THE REGION. BASED ON THE 27.14Z
HRRR...THE BACK EDGE OF THE SNOW AND SURFACE COLD FRONT SHOULD BE
TO THE MISSISSIPPI RIVER AROUND 00Z AND THROUGH WESTERN WISCONSIN
BY 4Z. FOR NOW...HAVE KEPT SOME CHANCES GOING INTO THE OVERNIGHT
HOURS...BUT WE MAY HAVE TO TREND THOSE BACK SOME WITH THE
AFTERNOON FORECAST PACKAGE.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
316 AM CST FRI JAN 27 2012
THE NEXT CHANCE FOR SOME PRECIPITATION WILL COME SUNDAY NIGHT INTO
MONDAY. AN AREA OF LOW PRESSURE WILL BE QUICKLY MOVING ACROSS
SOUTHERN CANADA WITH A WARM FRONT EXPECTED TO LIFT NORTHEAST
THROUGH THE REGION. THE GFS IS SHOWING AROUND 4 UBAR/S OF
ISENTROPIC UP GLIDE ON THE 280K SURFACE AHEAD OF THE WARM FRONT.
NOT A LOT OF OTHER FORCING SO ONLY SOME LIGHT PRECIPITATION
EXPECTED AS THIS COMES THROUGH. FOR NOW HAVE CARRIED THE CHANCES
ALL THE WAY THROUGH MONDAY...BUT THE AFTERNOON COULD END UP DRY.
IF THE PRECIPITATION DOES EXTEND INTO THE AFTERNOON...SOME
PRECIPITATION TYPE CONCERNS WILL COME INTO PLAY AS A WARM NOSE
ALOFT DEVELOPS. SOME ADDITIONAL CHANCES FOR PRECIPITATION COME IN
FOR TUESDAY AND TUESDAY NIGHT...BUT CONFIDENCE IS NOT HIGH AS THE
ECMWF AND 27.00Z GEM SHOW A SURFACE LOW MOVING EAST/SOUTHEAST
ACROSS THE NORTHERN GREAT LAKES WHILE THE GFS BRINGS THE LOW OUT
OF THE SOUTHWEST TOWARD THE GREAT LAKES. FOR NOW HAVE STAYED WITH
THE MODEL CONSENSUS WHICH HAS 20 TO 30 PERCENT CHANCES.
&&
.AVIATION...TODAY AND TONIGHT
536 AM CST FRI JAN 27 2012
SFC LOW/MID LEVEL SHORTWAVE ENERGY OVER THE DAKOTAS AND UPSTREAM
WILL DIG SOUTHEAST AND EAST ACROSS MN/WI TODAY/THIS EVENING. VFR
CONDITIONS WILL HOLD AT THE TAF SITES THRU THE MORNING WITH AN
INITIAL DRY LOW LEVEL AIRMASS IN PLACE. FORCING/LIFT AHEAD OF THE
LOW/SHORTWAVES IS EXPECTED TO EVENTUALLY SATURATE THE COLUMN OVER
THE AREA...WITH A BAND OF SNOW TO MOVE INTO THE TAF SITES AROUND MID
AFTERNOON AND PERSIST INTO THE EVENING. VSBYS EXPECTED TO QUICKLY
DROP TO IFR ONCE THE SNOW STARTS BUT WITH THE BULK OF THE
FORCING/LIFT ABOVE 850MB AND THE INITIAL DRY AIRMASS...MOST CIGS
LATER THIS AFTERNOON/EVENING EXPECTED TO BE MVFR BUT MAY DROP TO IFR
IN ANY AREAS OF MDT SNOW. FORCING LIFT EXIT EAST OF THE AREA BY
MIDNIGHT WITH THE SNOW DIMINISHING/ENDING. SFC COLD FRONT SWEEPS
THRU DURING THE EVENING WITH WINDS BECOMING WEST/NORTHWEST AND
INCREASING INTO THE 12-18KT RANGE WITH 25-30KT GUSTS. THESE WINDS
MAY PRODUCE SOME DRIFTING/BLOWING OF THE NEW INCH OR SO OF
SNOW...ESPECIALLY AT SITES LIKE KRST. CARRIED A BLSN SNOW MENTION AT
KRST THRU MUCH OF THE EVENING. SHOULD SEE IMPROVEMENT IN CIGS/VSBYS
AFTER 06Z. DID LEAVE CIGS MVFR LATE TONIGHT WITH AREAS
BKN-OVC015-025 SHOWING UP IN ND EARLY THIS MORNING BEHIND THE COLD
FRONT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
316 AM CST FRI JAN 27 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM....04
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
306 AM EST SUN JAN 29 2012
.Short Term (Today and Tonight)...
...A Windy Day Ahead...
The main challenges in the short term period are gusty winds today
and the slight chance for precip over southeast Indiana and the
northern Bluegrass. These challenges are courtesy of an upper level
wave crossing the Great Lakes and associated sfc front passing
through our area this afternoon.
First of all, light precip may fall over southeast Indiana and the
northern Bluegrass from 18Z-0Z. The latest RR model has the best
handle on this precip which was over southern MN, central Iowa, and
western WI as of 730Z. This clipper will push a thin band of low
level moisture into the Ohio Valley this afternoon. Model soundings
indicate temps will be cold enough aloft for ice crystal
production. However, sfc temps will be in the upper 30s and low 40s
by the afternoon hours, so precip should reach the sfc as just plain
rain with maybe some ice pellets mixing in. Precip will exit the
area by 0Z.
As for winds, a 35-40 kt LLJ will push through our area just ahead
of the front today. This will create the potential for wind gusts
in the 30-40 mph range over southern Indiana and central KY. Will
go ahead and issue an SPS for most of this area. Over the Bluegrass
region, however, it looks like the LLJ will cross during peak mixing
which may cause peak wind gusts in the 40 to 45 mph range. GFS,
SREF, and NAM soundings all indicate gusts into this range,
therefore, felt confident enough to issue an wind advisory from
along and east of a line from Scott County to Casey County in KY.
This matches well with ILN wind advy and JKL lake wind advy. The
Bluegrass advy will be valid from 16Z-23Z.
As for temps, we should see a gradient of highs from north to south
today with the colder, cloudier southern Indiana/northern KY area
only reaching the lower 40s for highs while the warmer, sunnier
south central KY area reaches the upper 40s. Low temps tonight
should cool into the mid 20s to around 30.
.Long Term (Monday through Saturday)...
We`ll sit under a fairly flat flow early in the long term, until a
weak wave moves into the Great Lakes Tuesday night...then a slightly
stronger one enters the Ohio Valley Wednesday night, and then a much
deeper upper trof dives into much of the eastern United States
Friday-Saturday. This should translate into tranquil weather early
in the long term and then increasingly unsettled conditions (not to
mention model disagreement) in later periods.
Will lean, with great trepidation, towards a blend of the
operational GFS/GFS ensemble mean/GEM ensemble mean, which are in
decent (albeit tenuous) agreement with each other. The operational
ECMWF goes off on its own by late in the week and is not in good
agreement with its own ensemble mean (which has some similarities to
the above mentioned suite of models). Unfortunately since there is
so much disagreement among the models it`s difficult to put much
faith in any solution.
Forging ahead anyway, at this time we will go with high pressure
over the southeast U.S. Monday-Tuesday. A tight gradient on the
backside of the high will pump warm air northward on stiff SSW
breezes. As a result, we went with rather warm temperatures for the
first couple of days of the new work week, including at night since
it appears the breezes will keep up around 10mph even after sunset.
Tuesday night should be especially warm ahead of an approaching cold
front. We should see gusts to at least 25 mph Monday afternoon and
30 mph Tuesday afternoon.
That cold front will approach from the northwest Tuesday night and
push through the LMK CWA on Wednesday, weakening as it does so.
Showers look likely with this feature Tuesday night-Wednesday,
tapering off Wednesday evening. No thunder is expected.
Thursday through Saturday are a mess in the model data. Inkling
right now is that Thursday may be dry as we sit between systems,
but given the Euro`s strong precipitation signal and in attempting
to blend with surrounding offices, will need to hang on to a small
POP.
Thursday night into Saturday a deep upper trof will dig into the
eastern U.S. and will bring chances of light, spotty precipitation
Thursday night into the weekend. Most of the precip should be in
the form of rain, though some snow could mix in late Friday night
into Saturday morning.
&&
.Aviation (06Z TAF Issuance)...
The main aviation concern for the next 24-30 hrs will be winds as a
weak clipper passing over the Great Lakes today will drag a weak
cold front over the TAF sites this afternoon. Ahead of the front, a
good LLJ will get going overnight. However, as noted with the
evening update, models are a little slower with the system and thus
the LLJ will be delayed into SDF. By the time it reaches SDF around
13-15Z, good mixing will have already begun and thus decided to take
the LLWS out of SDF TAF. Nevertheless, SW winds will certainly pick
up after sunrise with gusts in the 20-25kt range through late
morning. By the afternoon hours, 0Z NAM Bufkit soundings indicate
gusts into the 25-30 kt range. Looking at winds in the lower
levels, the potential is there for gusts into the 30-35 kt range.
Gusts in the 6Z TAFs are more of an average afternoon range, but it
should be noted that peak gusts for the day will likely be higher.
A distinct wind shift from SW to W with the weak front should occur
at SDF and LEX around 21Z and 22Z respectively. The front should be
too weak at BWG to create a distinct wind shift...it may be more
gradual during the late afternoon/early evening hours. Gusts should
decrease around or just after sunset. VFR CIGS/VSBYs are expected
through the TAF period. Any isld light precip with the clipper
system should stay to the north of the TAF sites.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...WIND ADVISORY FROM 11 AM THIS MORNING TO 6 PM EST THIS EVENING
FOR THE BLUEGRASS REGION.
$$
Short Term.......AMS
Long Term........13
Aviation.........AMS
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
259 AM EST SUN JAN 29 2012
.SYNOPSIS...
A DRY COLD FRONT WILL MOVE THROUGH THE AREA TONIGHT...THEN ANOTHER
SUNDAY NIGHT. HIGH PRESSURE WILL BUILD OVER THE SOUTHEAST MONDAY
THROUGH WEDNESDAY. A FRONTAL BOUNDARY WILL SLOWLY MOVE THROUGH THE
AREA THURSDAY NIGHT INTO FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1230 AM SUN...MINOR UPDATE FOR CLOUD COVER WITH SHRT WV MOVING
THROUGH AREA LATER TONIGHT INTO SUN MORNING. MODERATE CAA URGE
DEVELOPING OVER AREA IN WAKE OF DRY COLD FRONT MOVING OFFSHORE WHILE
MID CLOUDS WITH UPR LVL FEATURE ARE SLOWER TO MOVE E. LATEST GDNC
INDICATES THIS ACTVTY MOVING ACROSS LATER TONIGHT INTO SUN MORNING.
MINOR ADJUSTMENTS FOR CURRENT TEMP TRENDS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM/...
AS OF 3 PM SAT...STRONG HIGH PRESSURE WILL CONTINUE TO BUILD OVER
THE DEEP SOUTH AND SE STATES. COOLER CONDITIONS EXPECTED SUN WITH
N FLOW EARLY BEHIND THE FRONT...BECOMING W/SW IN THE AFTERNOON.
LOW LEVEL THICKNESS VALUES AND MOSTLY SUNNY SKIES SUPPORT HIGH
TEMPS IN THE 50S...MUCH CLOSER TO CLIMO NORMS FOR LATE JAN.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
SFC HIGH PRES MOVES ACRS THE FCST AREA MONDAY UNDER ZONAL FLOW
ALOFT. PLENTIFUL SUNSHINE BUT WITH LIGHT WINDS/LIMITED MIXING
AND A LOW LEVEL THICKNESS TROF OVER THE AREA...WILL UNDERCUT
MOS TEMPERATURE GUIDANCE A FEW DEGS.
A STRENGTHENING LOW LEVEL RETURN FLOW WILL BRING MODERATING
TEMPERATURES AS ZONAL FLOW REMAINS DOMINANT WITH DRY WEATHER THRU
WED.
A DECENT MODEL CONCENSUS IS DEVELOPING FOR A WEAK BACK DOOR COLD
FRONT TO DROP INTO THE AREA LATE WED NIGHT/EARLY THU BUT
THEREAFTER LONGER RANGE DETERMINISTIC MODEL CONSISTENCY IS
LACKING. RELUCTANT TO MAKE WHOLESALE CHANGES FOR THE LATE WEEK
INTO EARLY NEXT WEEKEND UNTIL BETTER MODEL CONSISTENCY/CONTINUITY
CAN BE ESTABLISHED.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /06Z SUNDAY THROUGH 06Z MONDAY/
AS OF 1230 AM SUN...VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD.
WINDS HAVE SHIFTED TO NW IN WAKE OF DRY FRONTAL PASSAGE AND MAY SEE
BRIEF PERIOD OF GUSTS TO 15-20KT NEXT FEW HOUR. SCT MID CLOUDS
MOVING ACROSS 09Z-12Z...OTRW CLEAR.
LONG TERM /MONDAY THROUGH THURSDAY/...
OUTSIDE OF THE USUAL LATE NIGHT AND EARLY MORNING GROUND FOG THAT
COULD CAUSE TEMPORARY REDUCTIONS IN VISIBILITIES...PREVAILING VFR
CONDITIONS ARE EXPECTED THROUGH WEDNESDAY AS HIGH PRESSURE
INFLUENCES THE WEATHER THROUGH WEDNESDAY. SCTD SHOWERS WITH THE
POSSIBILITY OF SUB VFR CONDITIONS LATER WED NIGHT INTO THU AS A
BACKDOOR COLD FRONT DROPS INTO THE REGION.
&&
.MARINE...
SHORT TERM /THROUGH SUNDAY/...
AS OF 1230 AM SUN...NO CHANGES WITH UPDATE. CAA SURGE DEVELOPING AS
EXPECTED IN WAKE OF DRY FRONTAL PASSAGE.
/PREVIOUS DISCUSSION/
AS OF 10 PM SAT...FORECAST LOOKS TO BE ON TRACK. CURRENT OBS
ILLUSTRATE A WSWLY FLOW AROUND 5-10KTS WITH SEAS HOVERING AROUND 3FT
ACROSS THE COASTAL WATERS. WINDS HAVE BEEN GUSTING AOA 20KT TO THE W
BEHIND FRONT AND MDLS SHOW GUSTY WINDS DEVELOPING ALONG THE COAST
AFTER FROPA. BASED ON LATEST RUC13 AND LOCAL WRF MDL HAVE ADDED SCA
FOR ALBEMARLE SOUND AS BOTH SHOW BRIEF PD OF 20 TO 25 KTS LATER
TONIGHT. WINDS WILL BE FAIRLY QUICK TO DIMINISH MID SUNDAY MORNING
AS FRONT MOVES FURTHER OFFSHORE. N WINDS WILL BACK THROUGH THE DAY
AND BECOME W/NW IN THE AFTERNOON.
LONG TERM /MONDAY THROUGH THURSDAY/...
WINDS/SEAS WILL BE DECREASING MONDAY AS HIGH PRES BUILDS TOWARD
THE NC WATERS. THEREAFTER...A S/SW RETIRN FLOW WILL DEVELOP AND
STRENGTHEN AS HIGH PRES MOVES OFF THE COAST THEN BUILDS OFFSHORE.
WINDS MAY REACH NEAR SMALL CRAFT ADVISORY LEVELS BY WED AFTN AND
CONTINUE INTO WED NIGHT AHEAD OF A BACKDOOR COLD FRONT MOVING DOWN
THE MID ATLC COAST. LOW CONFIDENCE FORECAST FOR THURSDAY DUE TO
THE UNCERTAINTY OF THE SOUTHWARD EXTENT OF BACK DOOR FRONT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST THIS MORNING FOR AMZ135.
SMALL CRAFT ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
AMZ130.
SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR AMZ150-
152-154.
SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR AMZ156-
158.
&&
$$
SYNOPSIS...CQD
NEAR TERM...JBM
SHORT TERM...CQD
LONG TERM...BTC
AVIATION...JBM/BTC/JME
MARINE...JBM/BTC/RF
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1240 AM EST SUN JAN 29 2012
.SYNOPSIS...
A DRY COLD FRONT WILL MOVE THROUGH THE AREA TONIGHT...THEN ANOTHER
SUNDAY NIGHT. HIGH PRESSURE WILL BUILD OVER THE SOUTHEAST MONDAY
THROUGH WEDNESDAY. A FRONTAL BOUNDARY WILL SLOWLY MOVE THROUGH THE
AREA THURSDAY NIGHT INTO FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 1230 AM SUN...MINOR UPDATE FOR CLOUD COVER WITH SHRT WV MOVING
THROUGH AREA LATER TONIGHT INTO SUN MORNING. MODERATE CAA URGE
DEVELOPING OVER AREA IN WAKE OF DRY COLD FRONT MOVING OFFSHORE WHILE
MID CLOUDS WITH UPR LVL FEATURE ARE SLOWER TO MOVE E. LATEST GDNC
INDICATES THIS ACTVTY MOVING ACROSS LATER TONIGHT INTO SUN MORNING.
MINOR ADJUSTMENTS FOR CURRENT TEMP TRENDS.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
AS OF 3 PM SAT...STRONG HIGH PRESSURE WILL CONTINUE TO BUILD OVER
THE DEEP SOUTH AND SE STATES. COOLER CONDITIONS EXPECTED SUN WITH
N FLOW EARLY BEHIND THE FRONT...BECOMING W/SW IN THE AFTERNOON.
LOW LEVEL THICKNESS VALUES AND MOSTLY SUNNY SKIES SUPPORT HIGH
TEMPS IN THE 50S...MUCH CLOSER TO CLIMO NORMS FOR LATE JAN.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
AS OF 3 PM SATURDAY...THE NORTHERN STREAM JET WILL DOMINATE EARLY
IN THE PERIOD WITH THE PASSAGE OF A SHORT WAVE TROUGH AND
ASSOCIATED SECONDARY DRY SURFACE COLD FRONT AGAIN SUNDAY NIGHT.
NEAR NORMAL HIGHS IN THE UPPER LOWER TO MIDDLE 50S ARE FORECAST ON
MONDAY AS AS COLD ADVECTION OCCURS WITH HIGH PRESSURE CRESTING
OVER THE AREA. A MODERATION IN TEMPERATURES INTO THE LOWER 60S
WILL OCCUR TUESDAY AS THE SURFACE HIGH MOVES OFF THE COAST AND
SOUTHERLY RETURN FLOW DEVELOPS. SOUTHERLY FLOW AND MILD
TEMPERATURES WELL INTO THE 60S WILL CONTINUE WEDNESDAY AND
THURSDAY. WEDNESDAY NIGHT A BACK DOOR COLD FRONT WILL STALL JUST
NORTH OF THE REGION THEN LIFT BACK TO THE NORTH THURSDAY AS
DEVELOPING LOW PRESSURE MOVES FROM THE TENNESSEE VALLEY TO OFF THE
MID ATLANTIC COAST. THIS SYSTEM WILL CIRCULATE MOISTURE FROM OFF
OF THE GULF OF MEXICO ACROSS THE CAROLINAS AND BRING A CHANCE OF
SHOWERS TO OUR REGION ON THURSDAY.
A COMPLEX PATTERN APPEARS TO BE SETTING UP FOR LATE NEXT INTO NEXT
WEEKEND AS A MEAN EASTERN UPPER TROUGH EVOLVES. A COLD FRONT WILL
APPROACH FROM THE WEST THURSDAY NIGHT...CROSSING THE REGION ON
FRIDAY BUT STALLING JUST SOUTH OF EASTERN NC. MILD TEMPERATURES ARE
EXPECTED TO CONTINUE FRIDAY AHEAD OF THE FRONT ALONG WITH A DECENT
CHANCE FOR SHOWERS. A SERIES OF WEAK LOW PRESSURE AREAS ARE FORECAST
TO MOVE ALONG THE STALLED FRONTAL BOUNDARY PRODUCING A COOLER AND
WET PATTERN ACROSS THE AREA OVER THE WEEKEND.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /06Z SUNDAY THROUGH 06Z MONDAY/
AS OF 1230 AM SUN...VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD.
WINDS HAVE SHIFTED TO NW IN WAKE OF DRY FRONTAL PASSAGE AND MAY SEE
BRIEF PERIOD OF GUSTS TO 15-20KT NEXT FEW HOUR. SCT MID CLOUDS
MOVING ACROSS 09Z-12Z...OTRW CLEAR.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 3 PM SATURDAY...OUTSIDE OF THE USUAL LATE NIGHT AND EARLY
MORNING GROUND FOG THAT COULD CAUSE TEMPORARY REDUCTIONS IN
VISIBILITIES...PREVAILING VFR CONDITIONS ARE EXPECTED THROUGH
WEDNESDAY. A DRY COLD FRONT WILL CROSS THE AREA SUNDAY NIGHT. DRY
HIGH PRESSURE WILL THEN INFLUENCE THE WEATHER MONDAY THROUGH
WEDNESDAY. SOUTHERLY FLOW OFF OF THE GULF OF MEXICO AHEAD OF AN
APPROACHING COLD FRONT THURSDAY WILL BRING A CHANCE OF A FEW
SHOWERS WITH THE POSSIBILITY OF SUB VFR CONDITIONS.
&&
.MARINE...
SHORT TERM /THROUGH SUNDAY/...
AS OF 1230 AM SUN...NO CHANGES WITH UPDATE. CAA SURGE DEVELOPING AS
EXPECTED IN WAKE OF DRY FRONTAL PASSAGE.
/PREVIOUS DISCUSSION/
AS OF 10 PM SAT...FORECAST LOOKS TO BE ON TRACK. CURRENT OBS
ILLUSTRATE A WSWLY FLOW AROUND 5-10KTS WITH SEAS HOVERING AROUND 3FT
ACROSS THE COASTAL WATERS. WINDS HAVE BEEN GUSTING AOA 20KT TO THE W
BEHIND FRONT AND MDLS SHOW GUSTY WINDS DEVELOPING ALONG THE COAST
AFTER FROPA. BASED ON LATEST RUC13 AND LOCAL WRF MDL HAVE ADDED SCA
FOR ALBEMARLE SOUND AS BOTH SHOW BRIEF PD OF 20 TO 25 KTS LATER
TONIGHT. WINDS WILL BE FAIRLY QUICK TO DIMINISH MID SUNDAY MORNING
AS FRONT MOVES FURTHER OFFSHORE. N WINDS WILL BACK THROUGH THE DAY
AND BECOME W/NW IN THE AFTERNOON.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 3 PM SATURDAY...MARGINAL SMALL CRAFT ADVISORY CONDITIONS
ARE EXPECTED AGAIN LATE SUNDAY NIGHT/EARLY MONDAY AS A SECONDARY
SURGE OF COOLER AIR PUSHES ACROSS THE WATERS. FREQUENT GUSTS TO 25
KT AND 5 TO 6 FT SEAS OVER THE OUTER WATERS WILL BE FORECAST.
CONDITIONS WILL IMPROVE AGAIN MONDAY AFTERNOON AND NIGHT AS A
STRONGER AND MORE PERSISTENT HIGH PRESSURE SYSTEM BUILDS OVER THE
WATERS. NW WINDS WILL DECREASE TO LESS THAN 15 KT MONDAY
AFTERNOON...AND 10 KT OR LESS MONDAY EVENING BEFORE BECOMING SW
10-15 KT LATE. SEAS WILL SUBSIDE TO 2 TO 3 FT MONDAY
AFTERNOON...AND 1-2 FT FOR MOST OF MONDAY NIGHT. SW WINDS 10-15 KT
WILL OCCUR TUESDAY AND TUESDAY NIGHT AS THE HIGH MOVES OFF THE
COAST WITH SEAS 2-3 FT TUESDAY BUILDING TO 3-4 FT TUESDAY NIGHT.
SW WINDS WILL INCREASE TO 15 TO 20 KT WEDNESDAY AHEAD OF A BACK
DOOR COLD FRONT WHOSE SOUTHERN EXTENT IS STILL UNDETERMINED.
CONSENSUS OF THE MODELS KEEP IT JUST NORTH OF THE NC WATERS.
MAGNITUDE AND DIRECTION OF WINDS FOR WEDNESDAY NIGHT INTO THURSDAY
STILL A LITTLE UNCERTAIN AS SOUTHWARD EXTENT OF BACK DOOR FRONT
UNKNOWN AND THERE WILL BE AN APPROACH OF A COLD FRONT FROM THE
WEST LATE. FOR NOW WILL FORECAST SW WINDS AROUND 15 KT AND SEAS
AROUND 3 FT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST SUNDAY FOR AMZ135.
SMALL CRAFT ADVISORY UNTIL 6 AM EST SUNDAY FOR AMZ130.
SMALL CRAFT ADVISORY UNTIL 1 PM EST SUNDAY FOR AMZ150-152-154.
SMALL CRAFT ADVISORY UNTIL 10 AM EST SUNDAY FOR AMZ156-158.
&&
$$
SYNOPSIS...CQD
NEAR TERM...JBM
SHORT TERM...CQD
LONG TERM...JME
AVIATION...JBM/JME
MARINE...JBM/RF/JME
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1051 PM CST SAT JAN 28 2012
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SYNOPSIS...MORE OF WHAT HAS COME TO BE THE NORM FOR THIS
WINTER...ABOVE NORMAL TEMPERATURES WITH ONLY A COUPLE MODEST PCPN
EVENTS.
UPR PATTERN CURRENTLY FEATURES MODEST TROF OVER THE N-C CONUS...
BUT FLOW WL FLATTEN BACK TO ZONAL REGIME DURING THE NEXT COUPLE
DAYS. MED RANGE MODELS AGREEDED IN GRADUALLY BUILDING SOME RIDGING
OVER WRN CANADA DURING THE LATTER PART OF THE FCST PERIOD. BUT RIDGE
NEVER SEEMS TO GET STG/SHARP ENOUGH TO FORCE A DISTINCT DOWNSTREAM
TROF OVER ERN CONUS. SO WL PROBABLY CONT WITH GENERAL WLY FLOW AND
FAIRLY HIGH UPR HGTS.
OTHER THAN A COUPLE GLANCING SHOTS OF COLDER AIR BEHIND INDIVIDUAL
WX SYSTEMS...THE FCST AREA WL PRIMARILY BE DOMINATED BY PACIFIC
AIR. THAT WL RESULT IN ABV NORMAL TEMPS. PATTERN WL SUPPORT A FEW
PCPN PRODUCING SYSTEMS...BUT NO STG STORMS IN THE OFFING.
&&
.SHORT TERM...TONIGHT AND SUNDAY.
THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW THE STATE
OF WISCONSIN LOCATED BETWEEN LOW PRESSURE OVER THE ONTARIO/QUEBEC
BORDER AND HIGH PRESSURE SITUATED OVER THE SOUTHERN PLAINS.
CYCLONIC FLOW AND THERMAL TROUGHING BETWEEN THESE FEATURES ARE
CONTRIBUTING TO A WIDESPREAD STRATO-CU FIELD STRETCHING FROM
NORTHERN MINNESOTA TO LOWER MICHIGAN. PLENTY OF SNOW SHOWER ACTIVITY
WITHIN THE COLDER CLOUD TOPS OVER NORTH-CENTRAL WISCONSIN AND THE
WESTERN UPPER PENINSULA EARLY THIS AFTERNOON. THE NEXT SHORTWAVE IS
OBSERVED PUSHING INTO NORTH DAKOTA WHICH WILL HEAD FOR THE REGION
TONIGHT. PRECIP CHANCES WITH THIS FEATURE AND CLOUD COVER ARE THE
MAIN FORECAST CONCERNS OVER THE NEXT 24 HOURS.
TONIGHT...SHORTWAVE TROUGH OVER THE DAKOTAS IS NOW EXPECTED TO TAKE
A SLIGHTLY MORE SOUTHERLY TRACK THAN PROJECTED YESTERDAY...FROM
ABOUT EASTERN SOUTH DAKOTA TO NORTHERN ILLINOIS. THOUGH THE WAVE
WILL STILL HAVE GOOD QG FORCING WITH IT...THE MORE SOUTHERLY TRACK
WILL SHIFT THE COMMA HEAD OF THE COMPACT WAVE OVER SOUTHERN
WISCONSIN RATHER THAN CENTRAL WISCONSIN. AS A RESULT...HAVE REMOVED
POPS FROM CENTRAL AND EAST-CENTRAL WISCONSIN TONIGHT.
OTHERWISE...CYCLONIC FLOW SUBTLY BROADENS OUT TONIGHT...WHICH SHOULD
ALLOW THE LOW STRATO-CU TO RETREAT TO THE NORTH. PLENTY OF FLURRY
ACTIVITY UPSTREAM WILL FORCE ME TO KEEP A MENTION OVER N-C
WISCONSIN. LOW LEVEL WINDS ARE TOO WESTERLY HOWEVER TO HAVE MUCH OF
A LAKE INFLUENCE. LOWS WILL RANGE FROM THE MIDDLE SINGLE DIGITS
ABOVE ZERO NORTH TO THE MID TEENS SOUTHEAST.
SUNDAY...MID-LEVEL CLOUDS FROM THE SHORTWAVE WILL DEPART TO THE
SOUTHEAST EARLY SUNDAY MORNING WHICH MAY LEAVE A PERIOD OF MOSTLY
SUNNY CONDITIONS OVER CENTRAL AND EAST-CENTRAL WISCONSIN TO START
THE DAY. LOW LEVEL WINDS WILL TURN BACK TO THE NORTHWEST BEHIND THE
DEPARTING WAVE. AS THIS OCCURS...COLD ADVECTION WILL RESUME WHICH
SHOULD LEAD TO ANOTHER SURGE SOUTHEAST OF THE LOW STRATO-CU LATE
MORNING INTO EARLY AFTERNOON. WINDS THEN BACK AROUND TO THE WEST MID
TO LATE AFTERNOON AS THE SURFACE RIDGE APPROACHES. SHOULD SEE THE
STRATO-CU BREAK UP SOME AS DRIER AIR PUSHES IN FROM THE WEST. HIGH
TEMPS RANGING FROM THE MID TEENS NORTH TO THE LOWER 20S SOUTHEAST.
.LONG TERM...SUN NGT THROUGH NEXT SAT. TEMPS WL PROBABLY FALL OFF
FAIRLY QUICKLY EARLY SUN NGT WITH SFC RIDGE COMING ACRS THE
AREA...BUT THEN START TO RISE AS CLDS INCR. ISENT LIFT WL SWEEP
EWD ACRS THE AREA LATE AT NGT AND MON MORNING. MODELS SEEMED A BIT
SLOWER WITH THE PCPN...SO TWEAKED TIMING BACK A BIT. TOOK THE N UP
TO LIKELIES MON MORNING. WL PROBABLY GET A COUPLE INCHES OF SNOW
ACRS THE N...AND MAYBE AN INCH OR SO IN THE S. PCPN WL PROBABLY
TAPER OFF TO FZDZ/DZ AS MIDDLE LEVEL MOISTURE GETS STRIPPED OFF TO
THE NE.
12Z RUN OF THE ECMWF BACKED OFF WITH PCPN CHCS TUE. THE OTHER
MODELS ALREADY WERE TAMER. MAY VERY WELL GET BY WITHOUT ANY PCPN
AS FCST AREA WL JUST BE IN THE WARM SECTOR OF WK CYCLONE TRACKING
ALONG THE U.S/CANADIAN BORDER. BUT DIDN/T WANT TO COMPLETELY PULL
PCPN WITH SYSTEM CROSSING THE RGN...SO SETTLED FOR TRENDING POPS
DOWN.
&&
.AVIATION...
UPPER-LEVEL DISTURBANCE OVER SOUTHERN MINNESOTA WILL PASS SOUTH OF
THE FORECAST AREA OVERNIGHT. GENERALLY VFR CIGS WITH SOME
SCATTERED MVFR AFTER 09Z ESPECIALLY AT RHI...CWA AND AUW.
VFR CONDITIONS TO PREVIAL AFTER ABOUT 16Z SUNDAY AS HIGH PRESSURE
BUILDS INTO THE REGION.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
EB
AREA FORECAST DISCUSSION
NWS ALBANY NY
1013 AM EST SUN JAN 29 2012
.SYNOPSIS...
THE PARADE OF FAST MOVING WEATHER SYSTEMS WILL CONTINUE
ACROSS THE NORTHEAST. HIGH PRESSURE RIDGED ALONG THE MID ATLANTIC
COAST WILL MOVE OFFSHORE THIS AFTERNOON...AS TWO COLD FRONTS WILL
MOVE ACROSS THE REGION THIS EVENING AND OVERNIGHT. ON MONDAY...HIGH
PRESSURE WILL BRIEFLY MOVE OVER THE NORTHEAST...THEN IT WILL SHIFT
OFFSHORE MONDAY NIGHT...AND A WARM FRONT WILL SET UP FROM THE UPPER
GREAT LAKES TO CAPE COD BY TUESDAY...PRODUCING SOME LIGHT SNOW FOR
THE REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 AM EST...WE CANCELED THE LAKE EFFECT SNOW ADVISORY FOR
NRN HERKIMER CTY...AS THE BAND AS SHIFTED NORTH OF THE AREA IN THE
BACKING LOW-LEVEL FLOW TO THE SW. THE BAND IS NOW IN THE ST
LAWRENCE RIVER VALLEY. SNOW TOTALS FROM THE LAKE EFFECT AND SNOW
SQUALLS THE PAST 12 TO 15 HOURS HAVE RANGED FROM 3 TO 7 INCHES
WITH SOME ISOLATED HIGHER AMOUNTS POSSIBLE. PLEASE SEE OUR LATEST
PNS STATEMENT.
THE TREND WILL BE FOR A BRIEF BREAK IN THE LATE MORNING INTO THE
EARLY PM FOR MOST OF THE REGION WITH THE RIDGING FROM THE SOUTH.
HOWEVER...ANOTHER POTENT SHORT-WAVE TROUGH IS APPROACHING FROM NRN
IL THIS MORNING. THIS STRONG UPPER LEVEL DISTURBANCE AND ITS
ASSOCIATED COLD FRONT WILL INCREASE THE CHANCE OF SNOW SHOWERS AND
ISOLD SQUALLS FROM WEST TO EAST LATE THIS AFTERNOON INTO THE
OVERNIGHT PERIOD. ONCE AGAIN...BASED ON THE 3-KM REF PRODUCT FROM
THE HRRR AND THE HIRES WRF FAVORS 00Z-03Z. THE HRRR IS FASTER WITH
A 22Z-01Z TIMING WITH THE FIRST BOUNDARY. A SECOND STRONGER
BOUNDARY WITH THE UPPER TROUGH...THE HRRR HAS APPROACHING
BTWN 03Z-06Z FOR THE FCST AREA. WE TRENDED THE SKY COVER TO PARTLY
TO MOSTLY SUNNY FROM THE HUDSON RIVER VALLEY EASTWARD INTO THE
EARLY TO MID PM...BEFORE THE CLOUD INCREASE AHEAD OF THE FIRST
FRONT. MAX TEMPS WILL STILL RUN ABOVE NORMAL WITH U30S TO L40S IN
THE VALLEYS...AND U20S TO M30S OVER THE MTNS. T/TD/RH/APPARENT
TEMP TRENDS WE REDONE BASED ON OBSERVATIONS. THE HIGHEST SNOW
ACCUMULATIONS WITH THIS DISTURBANCE LOOK LIKE THEY WILL BE NORTH
AND WEST OF OF THE CAPITAL REGION WITH 1 TO 4 INCHES POSSIBLE
/ESPECIALLY THE WRN DACKS AND WRN MOHAWK VALLEY/.
PREVIOUS NEAR TERM...
LAKE EFFECT BAND STILL PERSISTENT...AND SHOULD CONTINUE UNTIL WARM
ADVECTION BEGINS LATER THIS MORNING...WHEN THE BAND SHOULD BECOME
DISRUPTED. ALSO SOME ISOLATED SNOW SHOWERS AND FLURRIES STILL INTO
THE SCHOHARIE VALLEY. KEEPING THE SNOW IN THE FORECAST FOR THE
NEXT COUPLE OF HOURS IN THE SCHOHARIE VALLEY AND WESTERN MOHAWK
VALLEY...WHILE KEEPING THE NORTHERN HERKIMER AREA IN BETTER
CHANCES THROUGH THE MORNING. ONE REPORT OF JUST OVER A FOOT
WAS JUST RECEIVED...BUT KEEPING ADVISORY UP AS MOST AREAS SHOULD
SEE 7 INCHES OR LESS.
CLOUD COVER HIGHLY DEPENDENT ON LAKE EFFECT MOISTURE THIS MORNING
BUT THERE SHOULD BE LESS CLOUD COVER ONCE THE LAKE EFFECT BAND IS
DISRUPTED THIS AFTERNOON. SO...JUST SOME MINOR ADJUSTMENTS TO SKY
COVER AND TEMPERATURES THROUGH THIS MORNING.
PREV AFD BELOW...
LAKE EFFECT BAND STILL EXTENDING INTO THE WESTERN MOHAWK VALLEY AND
SOUTHERN ADIRONDACKS. IT IS A BIT CELLULAR AS THE DEPTH OF THE
MOISTURE AND INSTABILITY IS RELATIVELY DEEP...EVIDENT IN THE 00Z BUF
SOUNDING. THE BAND SHOULD CONTINUE TO BRING SNOW INTO THE AREA
THROUGH THE EXPIRATION OF THE WINTER WEATHER ADVISORY. SOME ISOLATED
REFLECTIVITIES ARE RESPECTABLE BUT BASED ON THERMAL PROFILES AND THE
RAPIDLY CHANGING CHARACTER OF THE BAND...SNOW RATIOS AND DURATION OF
HEAVIEST SNOW SEEMS TO SUGGEST SNOW SHOULD STAY WITHIN THE ADVISORY
RANGE. SNOWFALL AMOUNTS STILL LOOK TO BE UP TO 7 INCHES. SOME
ISOLATED SNOW SHOWER ACTIVITY ALSO EXTENDING INTO THE SCHOHARIE
VALLEY THROUGH THE EARLY MORNING HOURS BUT LIGHTER AND MORE
SCATTERED THAN THE SINGLE BAND TO THE NORTH.
WARM ADVECTION WILL BEGIN BY LATE MORNING...SO THE SINGLE BAND AND
THE SCATTERED ACTIVITY TO THE SOUTH IN THE SCHOHARIE VALLEY SHOULD
GET DISRUPTED AROUND OR SHORTLY AFTER SUNRISE. THERE SHOULD BE SOME
PERIODS OF SUN THROUGH AT LEAST THE MORNING...MAYBE INTO THE
AFTERNOON...ESPECIALLY IN EASTERN AREAS...DEPENDING ON HOW QUICKLY
THE NEXT SYSTEM APPROACHES FROM THE GREAT LAKES. BASED ON MIXING
POTENTIAL TODAY...HIGHS IN THE UPPER 30S TO MID 40S BEFORE CLOUD
COVER ARRIVES. HIGHS IN THE LOWER TO MID 30S IN THE SOUTHERN
ADIRONDACKS AND SOUTHERN GREEN MOUNTAINS.
NEXT QUICK MOVING NORTHERN STREAM SYSTEM TRACKS THROUGH THE REGION
TONIGHT...WHICH LOOKS TO BE RELATIVELY MOISTURE STARVED...EXCEPT FOR
WHAT COULD BE PICKED UP OFF THE GREAT LAKES. STILL...MOSTLY CLOUDY
MUCH OF THE NIGHT...WITH THE MOST WIDESPREAD SNOW SHOWER ACTIVITY IN
THE WESTERN MOHAWK VALLEY AND SOUTHERN ADIRONDACKS. SCATTERED
ACTIVITY SHOULD MAKE IT INTO MOST OF THE REGION...WITH MORE ISOLATED
ACTIVITY IN THE MID HUDSON VALLEY..SOUTHERN BERKSHIRES AND NW CT.
THERE COULD BE 1 TO 3 INCHES OF SNOW IN THE NORTHERN AREAS WITH
LOCAL DUSTINGS POSSIBLE ACROSS THE REST OF THE REGION. SOME PARTIAL
CLEARING IS POSSIBLE TOWARD SUNRISE...BUT GUSTY WEST TO NORTHWEST
WINDS SHOULD BEGIN AS THE SYSTEM EXITS LATE TONIGHT. LOWS IN THE
20S...BUT A LITTLE HIGHER THAN GUIDANCE NUMBERS DUE TO THE WINDS AND
MIXING. SOME LOWS IN THE TEENS IN THE SOUTHERN ADIRONDACKS.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
BACK DOOR CDFNT PUSHES SOUTH INTO FCA AS 500HPA SHORT WVS MOVE
EAST ACROSS NEW YORK NEW ENG. THIS WILL BRING A BRIEF PERIOD OF
COLD AIR AND REINVIGORATE LK EFFECT BAND INTO TUG HILL/W ADNDKS.
BY MON NT. LATE MONDAY INTO TUES EASTERN TROF DEPARTS...RIDGING
BUILDS FROM GRTLKS TO SE STATES AND A 500HPA SHORT WAVE EJECTS INTO
NORTHERN GREAT PLAINS. THIS SETS UP FRONTOGENESIS AS WMFNT ORGANIZES
DLH-BOS. MONDAY AND MONDAY NIGHTS CLOUDS BLOOM ALL ALONG AND AHEAD OF
IT...AND OVERRUNNING SNOW BREAKS OUT ACROSS THE GRTLKS.
MON NT INTO TUE MORNING THIS -SN SPREADS ACROSS NY/NEW ENG. THE
NAM/GFS/ECMWF ARE SIMILAR BUT NAM QPF IS DEFINITELY LIGHTER. THE
GEM HAS BULK OF PCPN N OF FCA. AS THE 500HPA FLOW TURNS SW THE
MODEL SUIT GENERALLY LIFTS TO WMFNT OUT OF THE FCA TUE
EVNG...LEAVING AREA IN WARM SECTOR WITH -SHRA THREAT TILL CDFNT
MOVES THROUGH WED. THEY ALL TAKE MAJOR CYCLONE WITH THIS SYSTEM
WELL NORTH INTO ONT/QB.
TEMPS ARE GENERALLY ABV NORMAL TO MUCH ABV DURING THIS PERIOD.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
THE FAST MOVING PATTERN CONTINUES WITH A SHORT WV MOVING THROUGH
THUR TRIGGERING ISOLD TO SCT -SHSN...MORE NEAR THE LAKE. HIGH
PRESSURE RIDGES SOUTH TO END THE WEEK WITH DRY CONDS...THEN THE
MODELS TAKE THE BIG DIVERGE. THE GFS PRODUCES A SIGNIFICANT
COASTAL LOW...AS USUAL BASED ON THE PHASING OF SHORT WAVES THAT
ARE SCATTERED ALL OVER EAST ASIA. THE ECMWF TAKES THIS STORM...NOT
UP THE EAST COAST...BUT UP THE ST LAWRENCE VLY. THE MODEL SUITE
HAS BEEN ALL OVER WITH THIS SYSTEM FROM IN THE WEST ATLC. FOR NOW
CARRIED CHC OR SLIGHT CHC. THERE`S 6 DAYS TO THE MODELS TO DEBATE
WITH THEMSELVES HOW THE SHORT WVS WILL PHASE. TEMPS DURING THE EFO
WILL BEGIN ABV NORMALS THU AND END THE PERIOD NEAR NORMAL.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
JUST SOME SCATTERED CLOUDS ABOVE 3000 FEET THROUGH THE MORNING...
THEN MID AND HIGH CLOUDS MOVE IN AHEAD OF THE NEXT SYSTEM THIS
AFTERNOON. SOME SCATTERED SNOW SHOWER ACTIVITY IS POSSIBLE AT KGFL
AND KALB AFTER 00Z SO ACKNOWLEDGING VCSH THERE. MOST OF THE SNOW
SHOWER ACTIVITY SHOULD STAY NORTH OF THE KPOU AREA. THE SNOW
SHOWERS SHOULD EXIT AFTER MIDNIGHT.
LIGHT WEST TO SOUTHWEST WINDS WILL INCREASE TO 10 TO 15 MPH AROUND
MID MORNING. GUSTY SOUTHWEST TO WEST WINDS SHOULD CONTINUE
THROUGH EARLY AFTERNOON AT 10 TO 15 MPH...WITH GUSTS OVER 20 MPH.
WINDS WILL BECOME SOUTH TO SOUTHWEST THIS AFTERNOON AT 10 MPH OR
LESS. ONCE THE SNOW SHOWER ACTIVITY MOVES OUT TONIGHT...WINDS
SHOULD SHIFT TO WEST AND NORTHWEST AT 10 TO 15 MPH...AND COULD GET
GUSTY.
OUTLOOK...
SUN NIGHT...VFR/MVFR. CHC -SHSN.
MON-TUE...VFR. NO SIG WX.
TUE NIGHT-WED...VFR/MVFR. CHC -SHRA/-SHSN.
THU...VFR...SLIGHT CHC -SHRA/-SHSN.
&&
.HYDROLOGY...
RIVER FLOWS CONTINUE TO RECEDE. A CLIPPER LOW PRESSURE SYSTEM AND
TWO COLD FRONTS WILL IMPACT THE REGION THIS EVENING INTO MONDAY
MORNING. SOME SCATTERED SNOW SHOWERS AND FLURRIES WILL BE COMMON
WITH LIGHT SNOW ACCUMULATIONS UP TO A FEW INCHES IN THE SOUTHERN
ADIRONDACKS. A WARM FRONT WILL ALSO BRING SOME LIGHT SNOW MONDAY
NIGHT INTO TUESDAY MORNING.
OVERALL...RIVER FLOWS WILL CONTINUE TO RECEDE INTO THE MID WEEK
ADN ANY RAINFALL THAT OCCURS WILL BE LIGHT AND MOST PRECIPITATION
DURING THE WEEK WILL BE LIGHT SNOW.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SNYDER/WASULA
NEAR TERM...NAS/WASULA
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...NAS
HYDROLOGY...NAS/WASULA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
645 AM EST SUN JAN 29 2012
.AVIATION /12 UTC TAFS/...
CONT VERY SIMILAR WRT RAPIDLY DETERIORATION OF MET CONDS LTR THIS AM
WITH ARRIVAL OF UPSTREAM WAVE. SLIGHT MOD TO LTR TIMING WITH REGARD
TO LWST CONDS...THOUGH STILL BRIEF MENTION AT LIFR CONDS AT KSBN AND
IFR AT KFWA APPEARS BEST PER UPSTREAM TRENDS AND LATEST AVBL HRRR
AND RUC TRENDS. ANTICIPATE HIGH VARIABILITY IN OVERALL CONDS BEFORE
SETLLING BACK ABOVE FUEL ALT BY ERLY AFTN.
&&
.SHORT TERM...
YET ANOTHER DIFFICULT FCST WRT SHORT TERM...ESP FIRST PD WITH
ATYPICAL CLIPPER SYSTEM WITH LOWER THAN AVG CONFIDENCE AND BUST
POTNL/HIGH RANGE OF REASONABLE EXPECTATIONS ATTM. DISTINCTLY
CRIMPED SHORTWAVE/TROPOSPHERIC FOLD NEAR KALO ATTM PER NAM/WV
IMAGERY DIGGING THROUGH BASE OF PRIMARY HUDSON/JAMES BAY VORTEX
WITH ASSOCD EXTENSION TO ARCTIC/JUST NORTH OF 70N PARALLEL/VCNTY
BARROW. STRONG 8H-5H COLD POOL POISED NORTH OF IA VORTICY TO
PLUNGE SEWD INTO SRN LAKE MICHIGAN AROUND 15 UTC. CURRENT
HORIZONTAL ROLLS AIDED BY LEADING E-W BURST OF MIDLVL FGEN LARGELY
SHOULD RMN NORTH OF CWA IN PREFRONTAL WRLY FLOW ACRS SRN LK MI AND
WHERE GRTR LK/8H THERMAL INSTABILITY AND MSTR DEPTH RESIDE.
CONTINGENCIES ALSO INCLUDE HEDGED BETS TOWARD BREVITY IN SYNOPTIC
SCALE CONVECTIVE BURSTS ALONG AND IMMEDIATELY POST CLIPPER INTO
NWRN CWA AROUND 12 UTC. SFC REFECTION CONTS TO GARNER STRENGTH PER
INCRG FALL/RISE PRES COUPLET NRN IL/SRN MN ALREADY TO 5MB/3 HR
CHNG. DOWNSTREAM 0-0.5KM THETA-E STREAM FM ECNTL MO INTO WRN
CWA SHOULD HELP TO PRECONDITION/MAINTAIN MFLUX GAINS AS IT MOVES
ACRS SRN LK MI. BEST STACKED UVM/MSTR DEPTH/THERMAL INSTABILITY
ACRS FAR NWRN/NRN CWA. SATURATED DEPTH WANES WITH SRN/SERN CWA
EXTENT AS WELL AS COLLOCATION OF MIDLVL ASCENT PER INCRSG SLANTED
UPDRAFTS. ALSO BEST INTERLACE OF FINER RANGE MODEL SIGNALS OF
MIDLVL FGEN/DPVA/STRONGEST DEFORMATION BAND ACRS NRN/NWRN
CWA...OPTED FOR POTNL FOR BRIEFLY HEAVY SHSN MENTION MID-LATE AM
AS WELL. TEMPORAL PERSISTENCE SHOULD LIMIT ACCUMS TO 2-3 INCH AMOUNTS
ACRS NWRN/NRN AREAS AND SIMILARLY DCRSG TO LESS THAN AN INCH FAR
SRN CWA OWING LARGELY TO LESS DVLPD MSTR PROFILE. THOUGH FAR
NRN/NWRN CWA COULD SEE MORE SHOULD CBL VEER TOO GREAT POST
CLIPPER THIS AFTN AS HAVE HIGH RELIANCE ON DRIER/SINGLE DIGIT SFC
DPS POOLED INTO WRN WI ALREADY AS TO NEGATE SUSTAINABILITY OF AFTN
LES. WL ALLOW DAY SHIFT TIME TO ASSESS AFTN POTNL THAT WOULD PSBLY
NECESSITATE ADVISORY LEVEL AMOUNTS IN THIS REGN. LAKE INDUCED EQL
CRASH TOWARD EVENING AND TRANSITION TO SLGHT CHC EVE ACRS MI
COUNTIES.
LEE ROCKIES/PLAINS FOEHN TO ESTABLISH SHARP WARM FNTL BNDRY PUSHING
ENEWD OUT OF CNTL PLAINS SUNDAY NIGHT AND INTO WRN GRTLKS MONDAY.
SOME CONCERN WITH SATURATED MIDLVLS/THERMAL PROFILE AMID ELEVATED
WARM LYR ASCENDING COLD BLYR FOR MIX SLEET/SNOW ACRS FAR NRN/NERN
CWA WITH SIG I285-290K ASCENT. HAVE SLIGHT ADJUSTMENT TO WX WITH
ONLY LOW CHC POPS MON. ALSO CONCERN WITH SNOWMELT/SATURATION OF
BLYR FOR STRATUS/DRIZZLE/FOG POTNL MON NIGHT...HOWEVER NO
CONFIDENCE FOR MORE THAN CLOUD COVER INCRS WITH A FAINT INDIRECT
NOD TOWARD PSBLTY.
&&
.LONG TERM...
TUESDAY THROUGH SATURDAY
PERSISTENT DEEP UPPER TROUGH OVER THE NORTHERN PAC INTO NE
RUSSIA...WILL CONTINUE TO SUPPORT FAST NW FLOW THROUGH MUCH OF THE
EXTENDED PERIOD...WITH MILD PAC DOWNSLOPE FLOW. INHERENT DIFFICULTY
IN RESOLVING THIS TYPE OF FLOW PATTERN IN THE LONG TERM PERIOD WILL
CONTINUE TO SUPPORT A STRONG SIDE TOWARD FORECAST
CONSISTENCY/PERSISTENCE PER POPS/TEMPS. THIS IS ESPECIALLY TRUE
GIVEN POORLY ANALYZED TURBULENT NORTHERN STREAM FLOW WITH ROCKIES
INTERACTION. JET CORES/ASSOCIATED SUBTLE WAVES/AND CAA PROCESSES ARE
FAR FROM BEING RESOLVED...AND ATTM WILL SIDE HEAVY TOWARD FORECAST
PERSISTENCE...WHICH INCLUDES A WX MENTION FOR THE THE TWO IMPULSES
EXPECTED TO ADVECT THROUGH THE FLOW. THE ECMWF REMAINS THE MODEL OF
CHOICE. HOWEVER...IT/S SOLUTIONS CONTINUE TO EXHIBIT TRACK/STRENGTH
DIFFERENCES PER THE THUR PERIOD AS THE 00Z RUN HAS RE-INTRODUCED A
POTENT SW EJECTING UPPER TROUGH. THE PRIMARY IMPETUS FOR SUCH A
RADICAL SHIFT IN RUN-RUN SOLUTIONS IS THE JUXTAPOSITION OF A LONG
LATITUDINAL JET CORE...WITH THE NOSE OF THIS JET INTERACTING WITH
THE ROCKIES. EXPECT CONTINUED FLOW ADJUSTMENT WITH POP ADJUSTMENT.
FORECAST MODELS ARE BEGINNING TO TREND TOWARD POSITIVE HEIGHT
ANOMALIES OVER GREENLAND BY NEXT WEEKEND...A SOLUTION THAT WOULD
SUPPORT NEGATIVE AO INDICES WITH A STAUNCH CP/MODIFIED ARCTIC
AIRMASS INTRUSION POSSIBLE BEHIND THE FRI-SAT TROUGH PASSAGE.
TUE-THUR...WARM/MILD CONDITIONS WITH PASSING IMPULSES EXPECTED TO
SUPPORT PRECIP AT TIMES. BEST CHANCE FOR PRECIP LOOKS TO BE IN
THE TUE NIGHT PERIOD GIVEN CONTINUED PROGGED SUFFICIENT LL MOISTURE
AHEAD OF THE EXPECTED UPPER IMPULSE. DRY CONDITIONS STILL FAVORED
WED...GIVEN WIDESPREAD MODEL SUPPORT FOR WEAK SFC RIDGING. THUR
STILL REMAINS QUESTIONABLE GIVEN A POTENTIAL EJECTING SW CONUS UPPER
TROUGH. WILL NOT THROW OUT THE 00Z ECMWF...WHICH REMAINS A STRONG
OUTLIER. COMPLICATED FLOW WARRANTS STRONG CONSIDERATION OF THE
ECMWF...IN ADDITION TO THE FACT THE ECWMF CONTINUES TO HIGHLY OUT
PERFORM ALL OTHER LONG RANGE FORECAST MODELS. HENCE...LEFT PREVIOUS
FORECAST NUMBERS WHICH COVER THESE CONCERNS. AGAIN...MILD CONDITIONS
EXPECTED AS TEMPS WILL EXCEED 50 IN THE PERIOD MANY PLACES...ESP IF
ENOUGH INSOLATION IS ATTAINED. HAVE CONTINUED ABOVE NORMAL TEMPS.
FRI-SAT...SIGNALS FOR SIG FLOW ADJUSTMENT SUPPORTS A DOWNTREND IN
TEMPS BY THE WEEKEND BACK TO CLIMO...WITH SIGNIFICANTLY COOLER
NUMBERS POSSIBLE BY SUN IF SUBSTANTIAL GREENLAND RIDGING DEVELOPS.
OTHERWISE...RETAINED LOW CHANCE SNOW MENTION SAT GIVEN A LIKELY FLOW
ADJUSTING IMPULSE/CP FRONT.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 5 AM EST MONDAY FOR LMZ043-046.
&&
$$
SHORT TERM...MURPHY
LONG TERM...JC
AVIATION...MURPHY
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
734 AM CST SUN JAN 29 2012
.UPDATE...
RADAR RETURNS SHOW THE BULK OF THE SNOW IS NOW EAST OF THE CWFA
WITH ONLY LINGERING FLURRIES REMAINING. RUC TRENDS AGREE WITH
WATER VAPOR IN PLACING THE MAIN VORT MAX OVER NORTHEAST ILLINOIS.
A SECONDARY VORT WAS APPROACHING THE MISSISSIPPI RIVER PER THE RUC
WITH A VORT LOBE INTO NORTHEAST IOWA. THE VORT LOBE IS HELPING TO
MAINTAIN FLURRIES AND THE AXIS OF THIS LOBE WILL BE EAST OF THE
MISSISSIPPI BY MID MORNING. AT THIS TIME STRONG DOWNWARD MOTION
WILL BE ACROSS THE CWFA WHICH WILL END THE PRECIPITATION THREAT.
AN UPDATE TO THE FCST TO REFLECT THE CURRENT TRENDS HAS BEEN SENT.
..08..
&&
.PREV DISCUSSION... /ISSUED 533 AM CST SUN JAN 29 2012/
AVIATION...
OVERALL RADAR TRENDS INDICATE THE BULK OF THE -SN IS GENERALLY
DONE. SOME FLURRIES WILL BE POSSIBLE THROUGH 15Z/29 AT KDBQ WITH
MVFR CONDITIONS. OTHERWISE...VFR CONDITIONS WILL BE SEEN AT
KCID/KMLI/KBRL WITH VFR DVLPG THROUGH 18Z/29 AT KDBQ. AFT 03Z/30
STRONG SOUTHWEST FLOW ALOFT WILL BRING MID AND HIGH LEVEL CLOUDS
INTO EASTERN IOWA AND NORTHERN ILLINOIS BUT VFR CONDITIONS ARE
EXPECTED AT ALL TAF SITES.
.08..
PREV DISCUSSION... /ISSUED 339 AM CST SUN JAN 29 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS A WEAK INFERRED LOW WEST OF KONA WITH A WARM
FRONT EAST INTO CENTRAL WISCONSIN. A COLD FRONT EXTENDS WEST FROM
THE LOW INTO NORTHEAST SOUTH DAKOTA. A TROF RAN SOUTH FROM THE LOW
TO KFNB. DEW POINTS WERE GENERALLY IN THE TEENS AND 20S ACROSS THE
MIDWEST WITH SINGLE DIGITS IN PARTS OF THE UPPER MIDWEST AND
PLAINS. RADAR SHOWS -SN MOVING EAST SOUTH FROM MINNESOTA INTO
SOUTHERN WISCONSIN WITH PATCHY SNOW ACROSS PARTS OF IOWA.
SHORT TERM...TODAY AND TONIGHT...
RUC TRENDS HAVE BEEN VERY USEFUL IN DEPICTING THE IMMEDIATE SHORT
TERM.
THE BULK OF THE SNOW ASSOCIATED WITH THE CLIPPER SYSTEM IS FALLING
GENERALLY ALONG AND NORTH OF THE VORT MAX TRACK WHICH FITS
CONCEPTUALLY WHERE THE STRONGEST FORCING WOULD BE LOCATED. THE
VORT MAX WILL MOVE EAST SOUTHEAST INTO NORTHERN ILLINOIS AND
SHOULD BE OVER NORTHEAST ILLINOIS AT SUNRISE. THUS THE BEST SNOW
WILL BE JUST OUTSIDE OF THE CWFA BUT A TRAILING VORT LOBE WITH LOW
850-700MB CONDENSATION PRESSURE DEFICITS AND RESPECTABLE FORCING
SHOULD ALLOW SOME -SN TO MOVE INTO THE HWY 20 CORRIDOR...
ESPECIALLY ALONG AND EAST OF DUBUQUE. F VECTOR CONVERGENCE AND
SOMEWHAT LOW CONDENSATION PRESSURE DEFICITS WITH SOME FORCING
SHOULD ALLOW -SN TO BE SEEN DOWN TO HWY 30 WITH FLURRIES IN THE
I-80 CORRIDOR. BASED ON OVERALL TIMING FROM RADAR...A MAJORITY OF
THE -SN AND FLURRIES SHOULD BE DONE BETWEEN 8 AND 9 AM THIS
MORNING.
FROM MID MORNING THROUGH NOON SOME LINGERING FLURRIES MAY BE
POSSIBLE IN THE FAR EASTERN PARTS OF THE CWFA AS FORCING WEAKENS
AND CONDENSATION PRESSURE DEFICITS RISE.
CLEARING SKIES AND DRY CONDITIONS WILL BE SEEN THIS AFTERNOON.
WHAT WAS THOUGHT TO BE A DRY SUNDAY NIGHT HAS SEVERAL SIGNALS
SUGGESTING THAT MAY NOT BE THE CASE.
THE EARLY EVENING HOURS WILL BE DRY AS THE SFC RIDGE IS OVER THE
CWFA AND MOVES EAST OF THE AREA. TEMPERATURES SHOULD DROP QUICKLY
AFTER SUNSET BEFORE LEVELING OUT AND THEN STARTING A SLOW RISE.
STARTING AROUND MID EVENING STRONG WAA ALOFT BEGINS MOVING INTO
THE WESTERN CWFA WITH AN APPROACHING TROF/FRONT. THE STRENGTH OF
THE WAA COMBINED WITH LOWERING 850-700MB CONDENSATION PRESSURE
DEFICITS SUGGESTS THE POTENTIAL FOR PRECIPITATION. INDEED LOOKING
AT THE HEAVY RAIN AND LIFT TOOLS SHOWS RESPECTABLE SPEED AND
MOISTURE CONVERGENCE AROUND 850MB. MODEL FCST SOUNDINGS SHOW THE
MID LEVELS SATURATING TO VARYING AMOUNTS.
TAKING ALL THIS INTO CONSIDERATION AND NOTING THAT THE ATMOSPHERE
REMAINS FAIRLY DRY BELOW 850MB SUGGESTS THAT FLURRIES MAY BE
POSSIBLE STARTING AROUND MID EVENING WEST OF THE MISSISSIPPI AND
NORTH OF HWY 30 WITH THE ACTIVITY SPREADING EAST OF THE MISSISSIPPI
AND NORTH OF HWY 30 AFTER MIDNIGHT. FCST SOUNDINGS VERY LATE
TONIGHT DEVELOP A PRONOUNCED WARM LAYER ALOFT WHILE LOW LEVEL TEMPERATURES
REMAIN BELOW FREEZING. IF THE LOW LEVELS WERE CLOSE TO SATURATION
THIS WOULD BE A CLASSIC FREEZING RAIN PROFILE. HOWEVER...THE LOW
LEVELS REMAIN DRY OR DRY OUT EVEN FURTHER. THUS WILL KEEP ONLY A
MENTION OF FLURRIES GOING AFTER MIDNIGHT AS ANY PRECIPITATION
FALLING MAY HAVE TROUBLE REACHING THE SFC AND WOULD RESULT IN
EVAPORATIVE COOLING AS WELL.
08..
LONG TERM...MONDAY THROUGH NEXT SATURDAY...
SEMI-ZONAL FLOW WITH MUCH ABOVE NORMAL TEMPS TO TRANSITION TO NORTHWEST
FLOW LATE WEEK WITH COLDER TEMPS INTO NEXT WEEKEND.
MON... TEMPS WILL BE WELL ABOVE NORMAL. WARM FRONTAL PASSAGE EXPECTED
EARLY AM ACCOMPANIED BY CLOUDS WITH FLURRIES POSSIBLE NORTH... THEN
DECREASING CLOUDS AND GUSTY SW WINDS BY PM TO FUEL WARM-UP. 00Z NAM
IS CONSIDERABLY WARMER AT 925 MB (OVER 2 STANDARD DEVIATIONS ABOVE
NORMAL) ESPECIALLY ACROSS THE SOUTH WHERE IT SHOWS TEMPS AROUND 14C
BY 21Z. MEANWHILE... GFS AND ECMWF SHOW 925 MB TEMPS ONLY AROUND 8-9C
ACROSS SOUTH. NAM WOULD EASILY SUPPORT UPPER 50S TO MID 60S SOUTH
AND AROUND 50F NORTH ONLY MIXING TO 925 MB AND WOULD PUT RECORD HIGHS
IN SERIOUS JEOPARDY... ESPECIALLY OVER SOUTHEAST IA... WEST CENTRAL IL
AND NORTHEAST MO. GIVEN TIME OF YEAR AND LIKELIHOOD OF CONSIDERABLE
MID CLOUDINESS FOR A WHILE MON AM WITH STRONG MID LEVEL THETA-E ADVECTION
HAVE OPTED TOWARD MORE CONSERVATIVE GFS AND ECMWF... ESPECIALLY OVER THE
SNOW PACK NORTH OF HWY 30. REASONABLE AGREEMENT NOW EXISTS WITH
DETERMINISTIC MODELS AND ENSEMBLES MOVING A PROGRESSIVE SHORTWAVE
THROUGH NORTHERN PLAINS AND UPPER MIDWEST ON TUE. ATTENDANT FRONT
OR MORE LIKELY JUST A WIND SHIFT WILL PUSH THROUGH WESTERN AND TOWARD
CENTRAL IA LATE MON NGT. CWA WILL RESIDE IN WARM SECTOR WITH
S/SW WINDS AND INCREASING HIGH CLOUDINESS WITH POSSIBLY LOWER CLOUDS
ARRIVING LATE TO KEEP LOWS ON MILD SIDE AND ABOVE WARM SIDE OF GUIDANCE.
TUE... MODELS WHICH HAD BEEN CONSISTENT WITH LOW MEASURABLE QPF SIGNAL
ARE NOW OVERALL TRENDING DRIER INCLUDING SREF WHICH NOW SHOWS
PROBABILITY OF MEASURABLE PCPN AT OR BELOW 15 PERCENT AND ONLY FAR S/E.
THIS LIKELY DUE TO LOW LEVEL FLOW VEERING AHEAD OF FRONT OR WIND SHIFT
THEREBY REDUCING LOW LEVEL CONVERGENCE. WILL THEREFORE KEEP POPS ONLY AT
SLIGHT CHC ALL BUT FAR N/W FOR LIGHT RAIN WITH NAM...GFS AND ECMWF
SOUNDINGS ACTUALLY MORE SUPPORTIVE OF DRIZZLE WITH CONTINUED LOW LEVEL
MOISTURE ADVECTION. HIGHS TUE STILL WELL ABOVE NORMAL AS WEAK FRONT
OR WIND SHIFT GRADUALLY PASSES INTO TUE NGT. DESPITE CLOUDY SKIES ON TUE
HIGHS SHOULD STILL BE IN THE 50S SOUTHEAST 1/2 OR SO DUE TO MOISTURE
ADVECTION.
WED-SAT... FCST CONFIDENCE EXTREMELY LOW HEADING INTO LATE WEEK AND NEXT
WEEKEND. OVERALL PATTERN LOOKS TO BECOME HIGHLY AMPLIFIED BY THU-FRI
WITH RIDGING DEVELOPING OVER WESTERN NOAM. IN RESPONSE AN
AMPLIFYING DEEP TROUGH LIKELY OVER CENTRAL AND EVENTUALLY EASTERN CONUS.
ENSEMBLE SPREADS REMAIN QUITE LARGE DURING THIS TRANSITION PERIOD AND
DETERMINISTIC MEDIUM RANGE MODELS SHOWING VERY POOR RUN TO RUN CONTINUITY
AND LARGE VARIABILITY FROM MODEL TO MODEL ALL MAKING FOR EXTREMELY LOW
CONFIDENCE ON FCST DETAILS. MAIN CULPRIT FOR MODEL UNCERTAINTY LIES WITH
EVOLUTION OF SHORTWAVE ENERGY IN EVOLVING DEEP TROUGH. BOTTOM LINE... THE
GENERAL IDEA OF TRANSITION TO HIGHLY AMPLIFIED PATTERN BY NEXT WEEKEND
WITH SHARP WESTERN NOAM RIDGE LOOKS GOOD... BUT THE DEVIL LIES WITH THE
DETAILS AND HANDLING OF DOWNSTREAM SHORTWAVE ENERGY PACKETS. IT DOES SEEM
THAT THE MODELS WANT TO DEVELOP A CLOSED UPPER LOW AND CONCEPTUALLY FITS
WITH MAGNITUDE OF JET ENERGY AND BAROCLINICITY. ON SIDE NOTE... BRUTAL
COLD CONTINUES OVER AK WITH FAIRBANKS HAVING HIT -50F YSTDY FOR FIRST TIME
SINCE 2006. TYPICALLY BITTER COLD IN AK PORTENDS COLD COMING TO THE
LOWER 48... AND RECENT LOWERING TRENDS OF NAO/AO FROM DETERMINISTIC MODEL
RUNS OF GFS AND ECMWF WOULD CORROBORATE IDEA OF TURNING COLDER IN FEB
AFTER AN ABOVE NORMAL START. ..05..
CLIMATE...
RECORD HIGHS FOR JANUARY 30...
MOLINE.........59 IN 1988
CEDAR RAPIDS...55 IN 1988
DUBUQUE........52 IN 1890
BURLINGTON.....60 IN 1988
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1019 AM EST SUN JAN 29 2012
...Forecast Update...
Winds have begun to become gusty over the last hour with a couple of
sites gusting to around 30 mph already. For now will keep the wind
advisory in place where it is and watch observations to see if it
needs to be expanded later. Made some minor tweaks to the grids to
update them based on current conditions. Also removed the pops from
the far northern part of the forecast area this afternoon. While a
few flurries or sprinkles are not out of the question, the main area
of precipitation should remain to our north. Other than that, no
major changes. Updates will be out soon.
&&
.Short Term (Today and Tonight)...
...A Windy Day Ahead...
The main challenges in the short term period are gusty winds today
and the slight chance for precip over southeast Indiana and the
northern Bluegrass. These challenges are courtesy of an upper level
wave crossing the Great Lakes and associated sfc front passing
through our area this afternoon.
First of all, light precip may fall over southeast Indiana and the
northern Bluegrass from 18Z-0Z. The latest RR model has the best
handle on this precip which was over southern MN, central Iowa, and
western WI as of 730Z. This clipper will push a thin band of low
level moisture into the Ohio Valley this afternoon. Model soundings
indicate temps will be cold enough aloft for ice crystal
production. However, sfc temps will be in the upper 30s and low 40s
by the afternoon hours, so precip should reach the sfc as just plain
rain with maybe some ice pellets mixing in. Precip will exit the
area by 0Z.
As for winds, a 35-40 kt LLJ will push through our area just ahead
of the front today. This will create the potential for wind gusts
in the 30-40 mph range over southern Indiana and central KY. Will
go ahead and issue an SPS for most of this area. Over the Bluegrass
region, however, it looks like the LLJ will cross during peak mixing
which may cause peak wind gusts in the 40 to 45 mph range. GFS,
SREF, and NAM soundings all indicate gusts into this range,
therefore, felt confident enough to issue a wind advisory along and
east of a line from Scott County to Casey County in KY. This
matches well with ILN wind advy and JKL lake wind advy. The
Bluegrass advy will be valid from 16Z-23Z.
As for temps, we should see a gradient of highs from north to south
today with the colder, cloudier southern Indiana/northern KY area
only reaching the lower 40s for highs while the warmer, sunnier
south central KY area reaches the upper 40s. Low temps tonight
should cool into the mid 20s to around 30.
.Long Term (Monday through Saturday)...
We`ll sit under a fairly flat flow early in the long term, until a
weak wave moves into the Great Lakes Tuesday night...then a slightly
stronger one enters the Ohio Valley Wednesday night, and then a much
deeper upper trof dives into much of the eastern United States
Friday-Saturday. This should translate into tranquil weather early
in the long term and then increasingly unsettled conditions (not to
mention model disagreement) in later periods.
Will lean, with great trepidation, towards a blend of the
operational GFS/GFS ensemble mean/GEM ensemble mean, which are in
decent (albeit tenuous) agreement with each other. The operational
ECMWF goes off on its own by late in the week and is not in good
agreement with its own ensemble mean (which has some similarities to
the above mentioned suite of models). Unfortunately since there is
so much disagreement among the models it`s difficult to put much
faith in any solution.
Forging ahead anyway, at this time we will go with high pressure
over the southeast U.S. Monday-Tuesday. A tight gradient on the
backside of the high will pump warm air northward on stiff SSW
breezes. As a result, we went with rather warm temperatures for the
first couple of days of the new work week, including at night since
it appears the breezes will keep up around 10mph even after sunset.
Tuesday night should be especially warm ahead of an approaching cold
front. We should see gusts to at least 25 mph Monday afternoon and
30 mph Tuesday afternoon.
That cold front will approach from the northwest Tuesday night and
push through the LMK CWA on Wednesday, weakening as it does so.
Showers look likely with this feature Tuesday night-Wednesday,
tapering off Wednesday evening. No thunder is expected.
Thursday through Saturday are a mess in the model data. Inkling
right now is that Thursday may be dry as we sit between systems,
but given the Euro`s strong precipitation signal and in attempting
to blend with surrounding offices, will need to hang on to a small
POP.
Thursday night into Saturday a deep upper trof will dig into the
eastern U.S. and will bring chances of light, spotty precipitation
Thursday night into the weekend. Most of the precip should be in
the form of rain, though some snow could mix in late Friday night
into Saturday morning.
&&
.Aviation (12Z TAF Issuance)...
The main aviation concern for today will be winds as a weak clipper
passing over the Great Lakes will drag a weak cold front over the
TAF sites this afternoon. Along and just ahead of the front, a good
LLJ is ongoing. These strong winds aloft will give BWG, SDF, and
LEX gusty conditions today. SSW winds will pick up after sunrise
with gusts in the 20-25kt range through late morning. By the
afternoon hours, 0Z NAM Bufkit soundings indicate gusts into the
25-30 kt range...higher than that at LEX. Looking at winds in the
lower levels, the potential is there for peak gusts into the 30-38
kt range with the strongest gusts at LEX this afternoon. Have
increased TAF forecast gusts for LEX. Felt that ongoing forecast
gusts at SDF/BWG were pretty close although actual peak gusts for
the day will likely be a bit higher. A distinct wind shift from SW
to W with the weak front should occur at SDF and LEX around 21Z and
22Z respectively. The front should be too weak at BWG to create a
distinct wind shift...it may be more gradual during the early
evening hours. Gusts should decrease around or just after sunset.
VFR CIGS/VSBYs are expected through the TAF period. Any isld light
precip with the clipper system should stay to the north of the TAF
sites although LEX would stand the best chance at any isld rain
showers.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...WIND ADVISORY UNTIL 6 PM EST THIS EVENING FOR
KYZ036-037-040>043-
047>049-055>057-066-067.
$$
Update...........EER
Short Term.......AMS
Long Term........13
Aviation.........AMS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
543 AM EST SUN JAN 29 2012
...Updated Aviation Discussion...
.Short Term (Today and Tonight)...
...A Windy Day Ahead...
The main challenges in the short term period are gusty winds today
and the slight chance for precip over southeast Indiana and the
northern Bluegrass. These challenges are courtesy of an upper level
wave crossing the Great Lakes and associated sfc front passing
through our area this afternoon.
First of all, light precip may fall over southeast Indiana and the
northern Bluegrass from 18Z-0Z. The latest RR model has the best
handle on this precip which was over southern MN, central Iowa, and
western WI as of 730Z. This clipper will push a thin band of low
level moisture into the Ohio Valley this afternoon. Model soundings
indicate temps will be cold enough aloft for ice crystal
production. However, sfc temps will be in the upper 30s and low 40s
by the afternoon hours, so precip should reach the sfc as just plain
rain with maybe some ice pellets mixing in. Precip will exit the
area by 0Z.
As for winds, a 35-40 kt LLJ will push through our area just ahead
of the front today. This will create the potential for wind gusts
in the 30-40 mph range over southern Indiana and central KY. Will
go ahead and issue an SPS for most of this area. Over the Bluegrass
region, however, it looks like the LLJ will cross during peak mixing
which may cause peak wind gusts in the 40 to 45 mph range. GFS,
SREF, and NAM soundings all indicate gusts into this range,
therefore, felt confident enough to issue a wind advisory along and
east of a line from Scott County to Casey County in KY. This
matches well with ILN wind advy and JKL lake wind advy. The
Bluegrass advy will be valid from 16Z-23Z.
As for temps, we should see a gradient of highs from north to south
today with the colder, cloudier southern Indiana/northern KY area
only reaching the lower 40s for highs while the warmer, sunnier
south central KY area reaches the upper 40s. Low temps tonight
should cool into the mid 20s to around 30.
.Long Term (Monday through Saturday)...
We`ll sit under a fairly flat flow early in the long term, until a
weak wave moves into the Great Lakes Tuesday night...then a slightly
stronger one enters the Ohio Valley Wednesday night, and then a much
deeper upper trof dives into much of the eastern United States
Friday-Saturday. This should translate into tranquil weather early
in the long term and then increasingly unsettled conditions (not to
mention model disagreement) in later periods.
Will lean, with great trepidation, towards a blend of the
operational GFS/GFS ensemble mean/GEM ensemble mean, which are in
decent (albeit tenuous) agreement with each other. The operational
ECMWF goes off on its own by late in the week and is not in good
agreement with its own ensemble mean (which has some similarities to
the above mentioned suite of models). Unfortunately since there is
so much disagreement among the models it`s difficult to put much
faith in any solution.
Forging ahead anyway, at this time we will go with high pressure
over the southeast U.S. Monday-Tuesday. A tight gradient on the
backside of the high will pump warm air northward on stiff SSW
breezes. As a result, we went with rather warm temperatures for the
first couple of days of the new work week, including at night since
it appears the breezes will keep up around 10mph even after sunset.
Tuesday night should be especially warm ahead of an approaching cold
front. We should see gusts to at least 25 mph Monday afternoon and
30 mph Tuesday afternoon.
That cold front will approach from the northwest Tuesday night and
push through the LMK CWA on Wednesday, weakening as it does so.
Showers look likely with this feature Tuesday night-Wednesday,
tapering off Wednesday evening. No thunder is expected.
Thursday through Saturday are a mess in the model data. Inkling
right now is that Thursday may be dry as we sit between systems,
but given the Euro`s strong precipitation signal and in attempting
to blend with surrounding offices, will need to hang on to a small
POP.
Thursday night into Saturday a deep upper trof will dig into the
eastern U.S. and will bring chances of light, spotty precipitation
Thursday night into the weekend. Most of the precip should be in
the form of rain, though some snow could mix in late Friday night
into Saturday morning.
&&
.Aviation (12Z TAF Issuance)...
The main aviation concern for today will be winds as a weak clipper
passing over the Great Lakes will drag a weak cold front over the
TAF sites this afternoon. Along and just ahead of the front, a good
LLJ is ongoing. These strong winds aloft will give BWG, SDF, and
LEX gusty conditions today. SSW winds will pick up after sunrise
with gusts in the 20-25kt range through late morning. By the
afternoon hours, 0Z NAM Bufkit soundings indicate gusts into the
25-30 kt range...higher than that at LEX. Looking at winds in the
lower levels, the potential is there for peak gusts into the 30-38
kt range with the strongest gusts at LEX this afternoon. Have
increased TAF forecast gusts for LEX. Felt that ongoing forecast
gusts at SDF/BWG were pretty close although actual peak gusts for
the day will likely be a bit higher. A distinct wind shift from SW
to W with the weak front should occur at SDF and LEX around 21Z and
22Z respectively. The front should be too weak at BWG to create a
distinct wind shift...it may be more gradual during the early
evening hours. Gusts should decrease around or just after sunset.
VFR CIGS/VSBYs are expected through the TAF period. Any isld light
precip with the clipper system should stay to the north of the TAF
sites although LEX would stand the best chance at any isld rain
showers.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...WIND ADVISORY FROM 11 AM THIS MORNING TO 6 PM EST THIS EVENING
FOR THE BLUEGRASS.
$$
Short Term.......AMS
Long Term........13
Aviation.........AMS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
852 AM EST SUN JAN 29 2012
LATEST UPDATE...SHORT TERM...
.SYNOPSIS...(415 AM EST SUN JAN 29 2012)
ANOTHER WAVE OF LOW PRESSURE WILL ZIP BY THE AREA THIS MORNING...AND
WILL BRING ANOTHER ROUND OF SNOW TO THE AREA. THE HIGHEST
ACCUMULATIONS WILL BE ACROSS THE SOUTHWEST CORNER OF THE AREA...
INCLUDING ALLEGAN...HASTINGS...AND KALAMAZOO. 2 TO LOCALLY 4 INCHES
OF ADDITIONAL ACCUMULATION IS LIKELY FOR THESE AREAS WILL LESS
ELSEWHERE. A BRIEF BREAK IN THE WEATHER IS EXPECTED TONIGHT...BEFORE
A FRONT MOVES IN ACROSS THE AREA ON MONDAY. THIS WILL INITIALLY
BRING LIGHT SNOW TO THE AREA...WITH IT CHANGING OVER TO RAIN BY
MONDAY EVENING. MUCH WARMER TEMPERATURES IN THE 40S CAN BE EXPECTED
BY TUESDAY.
&&
.SHORT TERM...(852 AM EST SUN JAN 29 2012)
(TODAY THROUGH TUESDAY)
THE WINTER WEATHER ADVISORY IS ON TRACK.
BASED ON THE LATEST IR AND WATER VAPOR LOOPS PLUS OUR RADAR MOSAIC
WITH CONSIDERATION TO THE 10Z HRRR IT SEEMS THE HEAVIEST SNOWFALL IN
THE NEXT THREE HOURS (TILL NOON) WILL BE OVER OTTAWA...SOUTHERN
KENT...NORTHERN ALLEGAN AND BARRY COUNTIES AS THAT IS WERE THE
DEFORMATION BAND SEEMS TO BE SETTING UP. BASED ON THIS THE ADVISORY
AS IT IS SEEMS FINE. I WOULD EXPECT SNOWFALL RATES OF UP TO AN INCH
AN HOUR IN THOSE FOUR COUNTIES.
REST OF THE EARLIER DISCUSSION...WE SHOULD SEE THE SYSTEM IN THE
PROCESS OF MOVING EAST OF THE AREA AT 18Z...AND IT SHOULD BE GONE BY
21Z. W/NW FLOW WILL HOLD IN AND DELTA T/S WILL REMAIN IN THE MID
TEENS. THIS WOULD SUPPORT ONGOING LAKE EFFECT WITH ACCUMS. HOWEVER
SUBSIDENCE IN THE WAKE OF THE MORNING WAVE WILL LOWER INVERSION
HEIGHTS TO AROUND 3K FT ALONG WITH THE UPPER FLOW EXPECTED TO BE
TRANSITIONING TO ANTI-CYCLONIC. THE LATTER FACTORS MENTIONED LOOK TO
BE SIGNIFICANT ENOUGH TO DIMINISH LAKE EFFECT CHCS LATE THIS
AFTERNOON INTO THE EVENING. THE FLOW WILL TRANSITION FROM W/NW TO SW
BY OVERNIGHT TONIGHT.
AFTER A SHORT BREAK WITH LAKE EFFECT WINDING DOWN...AND SFC RIDGING
MOVING ACROSS TONIGHT...WE WILL SEE PCPN CHCS INCREASE DURING THE
DAY ON MON. THIS OCCURS AS HEIGHTS BUILD...AND AN ELEVATED
BAROCLINIC/FRONTAL ZONE PUSHES TO THE NE AS AN ELEVATED WARM FRONT.
ALL MODELS ARE BREAKING OUT PCPN ALONG THE FRONT ACROSS CENTRAL AND
NRN LOWER MI. THE BETTER CHC OF PCPN WILL BE AS YOU HEAD FURTHER TO
THE NE AS PCPN BECOMES MORE ORGANIZED. PCPN WILL START OUT AS ALL
SNOW THE FIRST PART OF MON. PCPN WILL TRANSITION TO MORE LIQUID THEN
MON AFTERNOON AS WARMER AIR ALOFT MOVES IN...AND WE GET SOME
BOUNDARY LAYER HEATING. WE COULD SEE SOME SLEET MIX IN MON AFTERNOON
AS A SMALL COLD LAYER AROUND 1-3K FT AGL WILL TAKE SHAPE RESULTING
FROM THE SFC HEATING AND THE WAA ALOFT.
THE FRONT MOVES OUT MON EVENING...LEAVING LOWER MICHIGAN DRY UNTIL
TUE AFTERNOON AS WE SEE THE PV ANOMALY/UPPER WAVE APPROACH. PCPN IN
THE FORM OF LIGHT RAIN/SHOWERS WILL DEVELOP TUE AFTERNOON WHEN WE
SEE GOOD WARM AND MOIST ADVECTION AND THE SYNOPTIC FORCING MOVE IN
AHEAD OF THE WAVE.
&&
.LONG TERM...(415 AM EST SUN JAN 29 2012)
(TUESDAY NIGHT THROUGH SATURDAY)
HAVE OPTED TO FOLLOW THE GFS THROUGH THE LONG TERM. THE ECMWF SPINS
UP A SYSTEM AND PUSHES SIGNIFICANT PRECIPITATION INTO THE SOUTHERN
GREAT LAKES ON THURSDAY. THE PMDHMD DISCUSSION FROM HPC FAVORS THE
GFS AT 84 HOURS EXPLAINING THAT THE ECMWF AS AN OUTLIER. WITH THIS
IN MIND...THE GFS HAS A FAIRLY BENIGN LONG TERM PERIOD.
A COLD FRONT SLIDES EAST ACROSS LOWER MICHIGAN TUESDAY NIGHT WITH
RAIN. 850MB TEMPERATURES APPEAR WARM ENOUGH FOR MAINLY RAIN BEFORE
THE PRECIPITATION SHUTS OFF ALONG THE FRONT OVERNIGHT.
BEYOND TUESDAY NIGHT...HAVE A DRY FORECAST WEDNESDAY THROUGH
SATURDAY. FAIRLY TOUGH TO HAVE A DRY FORECAST THIS TIME OF YEAR IN
THE MID LATITUDES...BUT NOTHING SIGNIFICANT ENOUGH TO INCLUDE IN THE
FORECAST AT THIS TIME. THE PATTERN ESSENTIALLY IS ZONAL TO BEGIN THE
LONG TERM TRENDING TOWARD AND UPPER TROUGH BY LATE IN THE WEEK.
A WEAK SHORTWAVE ALOFT PASSES THROUGH THE AREA ON THURSDAY...BUT
VERY LIMITED MOISTURE SHOULD KEEP US DRY. ANOTHER SHORTWAVE PASSES
WELL OFF TO OUR SOUTH THURSDAY NIGHT AND FRIDAY AGAIN MISSING THE
AREA WITH PRECIPITATION.
TEMPERATURES THROUGH THE PERIOD WILL BE ABOVE NORMAL WITH HIGHS UP
AROUND 40 DURING THE WEEK. BY SATURDAY...COLDER AIR IS FILTERING IN
WITH THE DEEPENING TROUGH. TEMPS OVER THE WEEKEND LOOK TO BE
TRENDING BACK TOWARD NORMALS.
&&
.AVIATION...(650 AM EST SUN JAN 29 2012)
COMPACT UPPER DISTURBANCE WILL SWING ACROSS THE TAF SITES THIS
MORNING BRINGING WITH IT SNOW. THE SNOW WILL GET A BOOST FROM LAKE
MICHIGAN AS WELL. CONDITIONS WILL TREND DOWN RAPIDLY THIS MORNING AS
THE PRECIPITATION MOVES ON SHORE. EXPECTING MODERATE TO OCCASIONALLY
HEAVY SNOW AT THE TAF SITES BETWEEN 13Z AND 21Z. KMKG...KGRR AND
KAZO WILL BE MOST IMPACTED. VFR CONDITIONS ARE IN PLACE AT MOST
SITES ACROSS THE AREA AT 12Z. BY MID MORNING MVFR WILL HAVE MOVED
IN...WITH A TREND TOWARD IFR...ESPECIALLY VISIBILITIES.
THIS AFTERNOON AND EVENING...VISIBILITIES AND CEILINGS WILL
IMPROVE...TO AT LEAST MVFR IF NOT VFR. EXPECT 2500-3500FT CEILINGS
AND FLURRIES FOR MUCH OF THIS EVENING AND TONIGHT.
&&
.MARINE...(415 AM EST SUN JAN 29 2012)
WE WILL MAINTAIN THE SMALL CRAFT ADVISORY THAT REPLACED THE GALE
WARNING LAST EVENING. WINDS HAVE COME DOWN A FAIR AMOUNT SINCE THE
EVENING UPDATE...AND THE THREAT FOR GALES HAS ENDED. WE MAY DROP
BELOW THE WIND CRITERIA FOR SMALL CRAFT ADVISORIES THIS
AFTERNOON...HOWEVER WAVES WILL REMAIN UP UNTIL THE WINDS INCREASE
AGAIN LATER TODAY. THE SAME THING WILL LIKELY HAPPEN TONIGHT INTO
MONDAY. WE WILL HOLD THE SCA THROUGH 12Z MON...AND THIS WILL MOST
LIKELY NEED TO BE EXTENDED AT SOME POINT.
&&
.HYDROLOGY...(415 AM EST SUN JAN 29 2012)
ONLY POTENTIAL HYDROLOGY ISSUE THIS WEEKEND WOULD BE SOME ICE
DEVELOPMENT/ICE JAMS AS SOMEWHAT COLDER AIR HAS MOVED IN PLACE. THIS
AIR IS NOT SIGNIFICANTLY COLD...AND WE SHOULD NOT DEVELOP A LOT OF
ICE.
THE OTHER ISSUE THAT COULD DEVELOP WOULD BE INCREASING RIVER LEVELS
DUE TO MELTING SNOW WITH THE WARMER TEMPERATURES MOVING IN AND
MELTING SNOW ALONG WITH SOME RAIN. WE DO NOT HAVE A SIGNIFICANT
SNOWPACK IN PLACE...AND WE ARE NOT EXPECTING SIGNIFICANT AMOUNTS OF
RAIN. THIS SHOULD KEEP THE FLOODING POTENTIAL FAIRLY LOW THROUGH MID
WEEK.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY FOR OTTAWA...KENT...IONIA...
ALLEGAN...BARRY...EATON...VAN BUREN...KALAMAZOO AND CALHOUN
COUNTIES.
LM...SMALL CRAFT ADVISORY IN EFFECT THROUGH 7 AM MONDAY FOR THE
ENTIRE NEARSHORE.
&&
$$
SYNOPSIS: NJJ
SHORT TERM: NJJ WDM
LONG TERM: DUKE
AVIATION: DUKE
MARINE: NJJ
HYDROLOGY: NJJ
AREA FORECAST DISCUSSION
NWS GLASGOW MT
345 AM MST SUN JAN 29 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH TUESDAY...
WATER VAPOR IMAGERY AND 500 MB HEIGHT FIELD SHOWING A BROAD TWO-
THEMED WEATHER PATTERN ACROSS THE CONUS. THE HUDSON BAY UPPER LOW
CONTINUES TO PINWHEEL A FEW SMALLER SCALE SHORT WAVE TROUGHS
THROUGH THE GREAT LAKES AND NORTHEASTERN CONUS REGIONS. GENERAL
BROAD SCALE UPPER LEVEL TROUGHING IS IN PLACE OVER THE REMAINDER
OF THE EASTERN CONUS. A WEAK UPPER LEVEL RIDGE OVER THE
SOUTHWESTERN CONUS REGION CONTINUES TO WEAKEN UNDER A
STRENGTHENING STORM SYSTEM NOW MOVING ON SHORE OVER THE PACIFIC
NORTHWEST AND QUICKLY MOVING EASTWARD THROUGH THE NORTHERN ROCKIES
REGION. A FEW VERY SMALL SCALE SHORT WAVE TROUGHS ARE SETTING OFF
SOME THUNDERSTORMS EARLY THIS MORNING OVER THE OLYMPIC PENINSULA
OF WASHINGTON STATE.
PLENTIFUL MOISTURE IS STREAMING ALONG AND OVER THE CONTINENTAL
DIVIDE...MAKING ITS WAY OVER NORTHEAST MONTANA THIS MORNING. AN
AREA OF STRATIFORM SNOW FALL HAS SPREAD ACROSS THE CWA OVERNIGHT
AND THROUGH THE EARLY MORNING HOURS WITH JUST A FEW HIGHER
EMBEDDED AREAS OF MODERATE SNOW WHICH LASTED ONLY FOR SUDDEN
SPURTS. LOOKS LIKE THE NAM WAS MORE CORRECT IN THE PRECIP
PLACEMENT BUT A LITTLE TOO BULLISH ON THE PRECIP AMOUNTS.
FORECAST CHALLENGES INVOLVE THE PROGRESSION OF THIS STORM SYSTEM AS IT
MOVES ACROSS NORTHEAST MONTANA...INCLUDING THE EXTENT OF SNOW FALL
OVER OUR EASTERN ZONES...THE TRANSITION FROM SNOW TO A RAIN AND
SNOW MIX TO RAIN THROUGHOUT THE DAY TODAY FROM SOUTHWEST TO
NORTHEAST...AND THE HIGH WINDS OVER THE LITTLE ROCKIES AND HIGHWAY
191 TODAY.
THE INITIAL PUSH OF SNOWFALL ACROSS NORTHEAST MONTANA HAS ALREADY
MADE ITS WAY ACROSS OUR CWA. ACCORDING TO THE LATEST HRRR MODEL
RUNS...THERE MAY BE ANOTHER PUSH OR BAND OF SNOWFALL SET TO MOVE
ACROSS THE CWA LATER THIS MORNING...BUT IT LOOKS TO AMOUNT TO NOT MUCH.
TEMPERATURES A LITTLE TRICKY THIS MORNING. WE MAY HAVE ALREADY
REACHED OUR MORNING LOWS DURING THE MIDNIGHT HOUR. SURFACE
OBSERVATION TRENDS SHOWING STEADILY INCREASING TEMPERATURES EARLY
THIS MORNING BEHIND THE WARM FRONT JUST WEST AND SOUTHWEST OF OUR
CWA BORDER. TRIED TO SHOW A NON-DIURNAL TEMPERATURE TREND THIS
MORNING TO REPRESENT THIS THINKING. AS THE FRONT PUSHES THROUGH
OUR CWA TODAY...SNOW WILL TRANSITION OVER TO A RAIN AND SNOW
MIX...THEN BECOME ALL RAIN THIS AFTERNOON AS TEMPERATURES QUICKLY
CLIMB TO WELL ABOVE NORMAL LEVELS FOR THIS TIME OF YEAR. EXPECT
THE RAIN AND SNOW MIX TO BE AN ISSUE ONLY FOR THE 6 HOUR PERIOD
TODAY BETWEEN EARLY MORNING AND MID DAY.
WESTERLY WINDS ALREADY EARLY THIS MORNING AT ZORTMAN MINE AND THE
DOT SITE SOUTH OF MALTA ARE GUSTING IN THE 40 TO 50 MPH RANGE. THE
HIGH WIND WARNING LOOKS TO BE WELL PLACED AND WELL TIMED. KEEP AN
EYE ON ADDITIONAL SURROUNDING AREAS OF HIGHER TERRAIN IN CASE A
STRAY HIGH WIND GUST MIXES DOWN TO THE SURFACE...SAY IN PETROLEUM
COUNTY.
TONIGHT...THE STORM SYSTEM MAKES A QUICK EXIT TO THE EAST AS AN
UPPER LEVEL SHORT WAVE RIDGE SUSTAINS THE WARM UP TODAY AND MONDAY
TO THE TUNE OF NEARLY 20 DEGREES ABOVE NORMAL FOR THIS TIME OF YEAR.
LATE MONDAY INTO EARLY TUESDAY...ANOTHER UPPER LEVEL DISTURBANCE
QUICKLY SLIDES OVER THE NORTHERN ROCKIES AND THROUGH NORTHEAST
MONTANA...BRINGING A SPOTTY AND DISORGANIZED CHANCE FOR RAIN AND
SNOW TO PORTIONS OF OUR CWA. BMICKELSON
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...
PATTERN TRANSITIONS FROM ACTIVE ZONAL FLOW TO A HIGH AMPLITUDE
RIDGE ACROSS THE WESTERN STATES DURING THE EARLY DAYS OF THE
EXTENDED PERIOD. MODELS INDICATE TWO SHORTWAVES SLIDING ACROSS
EASTERN MONTANA WITH REASONABLE AGREEMENT ON TIMING. THE FIRST
WAVE CROSSES NORTHEAST MONTANA TUESDAY NIGHT BUT IS VERY WEAK WITH
NOT MUCH MOISTURE SO EXPECT DRY CONDITIONS. SECOND WAVE FOLLOWS
CLOSE BEHIND ON WEDNESDAY/WEDNESDAY NIGHT. THIS WAVE IS STRONGER
WITH BETTER DYNAMICS AND MOISTURE BUT MODELS STILL SUGGESTING BEST
CHANCES FOR PRECIPITATION WILL BE ACROSS SOUTHWEST MONTANA WITH
UPPER FLOW VEERING AS RIDGE BUILDS TO THE WEST. WILL KEEP WITH
CONSENSUS FOR NOW AND STAY WITH DRY FORECAST.
RIDGE BEGINS TO DOMINATE THE NORTHERN ROCKIES BY THURSDAY WITH
WARM AIR PUSHING EAST OF THE DIVIDE. BY THE WEEKEND THE WARM AIR
WILL BE FIRMLY IN PLACE OVER MONTANA...ALTHOUGH WITH LITTLE WIND
MIXING WILL BE DIFFICULT. EBERT
&&
.AVIATION...
VFR. CLOUDS WILL LOWER THIS MORNING AS A DISTURBANCE TRACKS INTO
NORTHEAST MONTANA. OCCASIONAL MVFR CONDITIONS ARE POSSIBLE WITH A
LITTLE LIGHT SNOW THIS MORNING. WINDS WILL BECOME WESTERLY BY LATE
MORNING AT 10 TO 20 KTS THEN DIMINISH IN THE EVENING. RAE
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 5 PM MST THIS AFTERNOON FOR SOUTHWEST
PHILLIPS.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1023 AM EST SUN JAN 29 2012
.SYNOPSIS...
ANOTHER FAST MOVING WAVE OF LOW PRESSURE WILL TRACK ACROSS THE
REGION THIS AFTERNOON AND EVENING...BRINGING A WIDESPREAD LIGHT
SNOWFALL...FOLLOWED BY RENEWED LAKE SNOWS EAST OF THE LAKES TONIGHT
AS A WESTERLY FLOW OF BRIEFLY COLDER AIR SPREADS ACROSS THE LOWER
LAKES. AN APPROACHING WARM FRONT WILL THEN BRING ANOTHER ROUND OF
WIDESPREAD LIGHT SNOW TO THE AREA LATE MONDAY AND MONDAY NIGHT...
FOLLOWED BY A SIGNIFICANT WARMUP FOR TUESDAY AND ESPECIALLY
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM...RADAR SHOWS A BAND OF SNOW EXTENDING NORTH OF THE
BUFFALO AND ROCHESTER METRO AREAS. THIS BAND HAS BEEN QUITE
IMPRESSIVE AT TIMES THIS MORNING...BRINGING A QUICK TWO INCHES OF
SNOW TO SOME LOCATIONS. THE BAND HAS SINCE WEAKENED A BIT. MODELS
HAVE NOT HANDLED THIS BAND WELL AT ALL...WITH THE LIKELY CAUSE A
COMBINATION OF MID-LEVEL WARM AIR ADVECTION AND LAKE EFFECT
ENHANCEMENT. IR SHOWS LESS MOISTURE IN THE MID-LEVELS
UPSTREAM...WHICH SUGGESTS THAT THE BAND WILL CONTINUE TO WEAKEN.
THIS SAID...WILL MAINTAIN LIKELY POPS BUFFALO NORTHWARD THROUGH
MID-AFTERNOON...WITH AN ADDITIONAL INCH OR TWO POSSIBLE FROM THIS
BAND THROUGH MID-AFTERNOON. MEANWHILE...OFF LAKE ONTARIO...THE
LAKE EFFECT BAND PROMPTING ADVISORIES HAS DISSIPATED...AND THIS
ADVISORY HAS BEEN ALLOWED TO EXPIRE. DESPITE THIS...ADDITIONAL
SNOW IS ON THE WAY...WITH ANOTHER HEADLINE POSSIBLE IN THE NEAR
FUTURE. AN ADDITIONAL CONCERN FOR THIS AREA IS AS MOISTURE FROM
THE LAKE ERIE BAND WORKS ACROSS LAKE ONTARIO...THERE MAY BE
ADDITIONAL ENHANCEMENT THIS AFTERNOON. SEE DISCUSSION BELOW.
MODELS ARE CONSISTENT IN BRINGING A SHORTWAVE ACROSS THE REGION
LATE AFTERNOON. THE HRRR HAS JOINED THE RGEM/NAM12 OF BRINGING A
DECENT SNOW BURST LATE AFTERNOON INTO THIS EVENING. QPFS ARE
GENERALLY BETWEEN .10 AND .25 WITH THIS...WHICH IS MARGINAL FOR
ADVISORIES. HOWEVER...GIVEN THE POTENTIAL SNOWFALL RATES...WILL
CONSIDER AN ADVISORY FOR MARGINAL AMOUNTS...BASED ON IMPACT. THERE
ALSO WILL BE LAKE EFFECT AFTER THIS...WHICH FURTHER COMPLICATES
THE ISSUE. WOULD LIKE TO LOOK AT 12Z RUNS BEFORE MAKING HEADLINE
DECISIONS...BUT WILL LIKELY MAKE HEADLINE DECISIONS BEFORE THE
SCHEDULED 300 PM UPDATE.
IMMEDIATELY FOLLOWING THE DEPARTURE OF THE SURFACE WAVE THIS
EVENING...A WESTERLY TO WEST-NORTHWESTERLY FLOW OF COLDER AIR WILL
ONCE AGAIN SET UP ACROSS THE LOWER LAKES...WITH 850 MB TEMPS
DROPPING FROM AROUND -10C/-11C EARLY THIS EVENING TO AROUND -14C
BY MIDNIGHT. THIS WILL TRIGGER A RENEWED ROUND OF LAKE SNOWS EAST
/EAST-SOUTHEAST OF BOTH LAKES. OFF LAKE ERIE...THE RELATIVELY
SHALLOW MOISTURE FIELD AND LOW CAPPING INVERSION HEIGHT OF 5 KFT
SHOULD HELP KEEP THE LAKE SNOWS FAIRLY MINIMAL IN NATURE EAST OF
THE LAKE...WHERE ABOUT 1 TO 3 INCHES OF FRESH ACCUMULATION WILL BE
POSSIBLE THROUGH THE END OF THE NIGHT. OFF LAKE ONTARIO...THINGS
WILL BE A DIFFERENT STORY AS A MUCH DEEPER MOISTURE
FIELD...STRONGER LIFT...AND A CAPPING INVERSION OF AROUND 9-10 KFT
SHOULD ALLOW FOR ANOTHER ROUND OF ADVISORY-CRITERIA SNOWS. THE
MAIN QUESTION AT THIS POINT IS EXACTLY WHERE THESE WILL BE...AS
THE MODELS CONTINUE TO SHOW SOME VARIATION IN THE EXACT LOCATION
OF THE LAKE SNOW BAND...RANGING FROM THE 00Z NAM`S DEPICTION OF A
BAND EAST-SOUTHEAST OF THE LAKE...TO THE 00Z RGEM`S TUG HILL
POSITIONING.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
AT THE START OF THE PERIOD SOME LAKE EFFECT SNOW WILL PERSIST ON
MONDAY EAST OF THE LAKES WITH 850MB TEMPS BOTTOMING OUT AROUND -14C
DURING THE MORNING.
OFF LAKE ERIE...A SURFACE RIDGE WILL BUILD ACROSS THE LAKE DURING
THE MORNING AND DISRUPT/BACK THE LOW LEVEL FLOW AND ALSO DRY OUT THE
LOW LEVELS. THIS SHOULD BRING A QUICK END TO LAKE EFFECT WITH
LINGERING SCATTERED SNOW SHOWERS ACROSS THE WESTERN SOUTHERN TIER
LIFTING NORTH TOWARDS THE BUF SOUTHTOWNS AND FALLING APART WITH ONLY
VERY MINOR DUSTING TO AN INCH ACCUMULATIONS ON THE HILLS IN THE
EARLY MORNING.
OFF LAKE ONTARIO...CONDITIONS WILL STILL BE MORE FAVORABLE THROUGH
THE MORNING HOURS WITH LAKE INDUCED EQUILIBRIUM LEVELS AROUND 10K
FEET...DETERIORATING TO LESS THAN 7K FEET BY AFTERNOON AS THE
SURFACE RIDGE BUILDS ACROSS LAKE ONTARIO. THERE REMAINS SOME SPREAD
WITH BAND PLACEMENT IN THE LATEST 00Z MODEL SUITE WITH THE CANADIAN
GEM HOLDING THE LAKE EFFECT ACROSS NORTHERN OSWEGO COUNTY AND THE
SOUTHERN TUG HILL...WHILE THE NAM DROPS THE BAND INTO SOUTHERN
OSWEGO COUNTY AND EVEN CLIPS N.CAYUGA AND NE WAYNE COUNTY FOR
AWHILE. FOR NOW HAVE PLACED THE BAND ACROSS CENTRAL OSWEGO COUNTY
BUT THIS MAY NEED TO BE TWEAKED AS SHORT TERM MODEL GUIDANCE
CONVERGES ON A COMMON SOLUTION FOR BAND PLACEMENT. SYNOPTIC SCALE
MOISTURE IS DRYING OUT BY MONDAY MORNING...BUT MODERATE INSTABILITY
AND LONG FETCH SUGGEST THE POTENTIAL FOR SEVERAL MORE INCHES IN
PERSISTENT BANDS THROUGH THE FIRST HALF OF MONDAY. AN ADVISORY WILL
LIKELY BE NEEDED FOR THIS INTO MONDAY...BUT AS STATED IN THE NEAR
TERM DISCUSSION WE WILL WAIT UNTIL THE CURRENT ADVISORY EXPIRES
BEFORE RAISING A NEW ONE TO AVOID CONFUSION.
THE LAKE ONTARIO LAKE EFFECT WILL WEAKEN AND END MONDAY AFTERNOON AS
THE SURFACE RIDGE CROSSES THE LAKE AND DISRUPTS THE LOW LEVEL FLOW.
OUR ATTENTION THEN QUICKLY TURNS BACK TO THE SYNOPTIC SCALE. PAST
FEW RUNS OF THE GFS AND SREF HAVE BEEN CONSISTENT IN DEVELOPING AN
AREA OF LIGHT SNOW LATE MONDAY AFTERNOON ACROSS WESTERN NY...THEN
SPREADING EAST ACROSS THE REST OF THE AREA MONDAY NIGHT. THIS AREA
OF SNOW WILL BE SUPPORTED BY A MODERATE TO STRONG WARM ADVECTION
REGIME WITH AMPLE ISENTROPIC UPGLIDE AND MOISTURE CONVERGENCE ON THE
NOSE OF A 60 KNOT 700MB JET SUPPORTING A 3-5 HOUR PERIOD OF SNOW.
THE QUALITY OF DYNAMICS AND MOISTURE COMING TOGETHER SUGGEST THIS
MAY PRODUCE A GENERAL 1-3 INCH SNOW ACROSS MUCH OF THE REGION.
THE SNOW THAT FALLS OVER THE NEXT FEW DAYS WILL BE A THING OF THE
PAST BY MIDWEEK AS ANOTHER UNSEASONABLY STRONG WARM-UP ARRIVES
BEGINNING TUESDAY. IN FACT...FOLLOWING THE GENERAL SNOW MONDAY
EVENING TEMPERATURES WILL RISE OVERNIGHT IN THE MODERATE TO STRONG
WARM ADVECTION REGIME...AND WILL BE WELL ABOVE FREEZING ALREADY BY
TUESDAY MORNING FROM THE FINGER LAKES WESTWARD. ONGOING WARM
ADVECTION WILL SUPPORT HIGHS IN THE MID TO UPPER 40S ACROSS MUCH OF
WESTERN AND CENTRAL NY WITH A MAINLY DRY DAY AS THE WARM SECTOR
MIXES NORTHWARD.
THE WARM FRONT WILL HANG UP EAST OF LAKE ONTARIO WITH LIGHT SNOW
LINGERING ACROSS THE NORTH COUNTRY ON TUESDAY. MAY SEE A LITTLE MORE
MINOR ACCUMULATION TUESDAY MORNING...BUT BY AFTERNOON EVEN THERE THE
WARM AIR WILL BEGIN TO WIN OUT WITH TEMPERATURES RISING ABOVE
FREEZING AND ALLOWING RAIN TO MIX IN WITH ANY LEFTOVER LIGHT SNOW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
TUESDAY NIGHT THE HEART OF THE WARM SECTOR WILL BUILD INTO THE LOWER
LAKES AS A SURFACE LOW MOVES FROM THE UPPER LAKES TO WESTERN QUEBEC
BY WEDNESDAY MORNING. THIS WILL SUPPORT A VERY MILD NIGHT WITH MANY
LOCATIONS NOT DROPPING OUT OF THE 40S...WITH MID 30S EAST OF LAKE
ONTARIO. THE APPROACH OF THE MID LEVEL TROUGH AND BELT OF ENHANCED
LOW/MID LEVEL FLOW WILL SUPPORT INCREASING LARGE SCALE FORCING FOR
ASCENT...WITH RAIN CHANCES GOING UP OVERNIGHT. THE SURFACE COLD
FRONT WILL CROSS THE REGION WEDNESDAY MORNING WITH VERY MILD TEMPS
JUST AHEAD GIVING WAY TO FALLING TEMPS BY AFTERNOON. BEST RAIN
CHANCES WILL BE EARLY...WITH DRYING EXPECTED BY AFTERNOON IF THE
CURRENT MODEL TIMING HOLDS.
COLD ADVECTION BEHIND THE SYSTEM WILL BRING TEMPS DOWN...BUT STILL
ABOVE CLIMO FOR THURSDAY WITH A FEW LIGHT SNOW SHOWERS POSSIBLE EAST
OF THE LAKES.
LATER THURSDAY INTO NEXT WEEKEND FORECAST UNCERTAINTY QUICKLY
INCREASES WITH THE LATEST GFS AND ECMWF RAPIDLY BECOMING
DRAMATICALLY DIFFERENT IN THE SYNOPTIC DETAILS AND EVEN THE LARGE
SCALE PATTERN. THE GFS KEEPS A FLAT TROUGH ON THURSDAY WITH A
GRADUAL AMPLIFICATION NEXT WEEKEND WHICH WOULD TAKE A SOUTHERN
STREAM LOW TOO FAR SOUTH AND EAST TO HAVE MUCH IMPACT ON THE LOWER
LAKES...RESULTING IN A TURN TO COLDER TEMPS NEXT WEEKEND BUT MAINLY
DRY. THE ECMWF ON THE OTHER HAND BRINGS A STRONGER SOUTHERN STREAM
LOW OVER THE LOWER LAKES LATE THURSDAY AND THURSDAY NIGHT WITH RAIN
AND WET SNOW CHANGING TO SNOW. THIS IS FOLLOWED BY A MORE
SIGNIFICANT TROUGH AMPLIFICATION BY SATURDAY NIGHT AND SUNDAY WITH
SOME SEMBLANCE OF ANOTHER OHIO VALLEY LOW BRINGING A GENERAL
SNOWFALL TO THE REGION FOR THE SECOND HALF OF THE WEEKEND.
GIVEN THE LACK OF MODEL CONSISTENCY...WILL STICK CLOSE TO THE
PREVIOUS FORECAST FOR LATE IN THE WEEK INTO NEXT WEEKEND. THE
COMPLEXITY OF THE PATTERN EVOLUTION LATE NEXT WEEK WILL LIKELY
RESULT IN ONGOING MODEL UNCERTAINTY FOR SEVERAL MORE DAYS UNTIL
MODELS BEGIN TO CONVERGE ON A COMMON SOLUTION.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
FOR THE 15Z AMD...EXPECT VARIABLE CONDITIONS THROUGH MID-
AFTERNOON. PREDOMINANTLY MVFR-VFR CONDITIONS ARE EXPECTED.
HOWEVER...PERIODIC LAKE SNOWS WILL DRASTICALLY LOWER CONDITIONS AT
BUF/IAG/ART AT TIMES THIS MORNING. TAFS BASICALLY FOLLOWING RADAR
TRENDS DURING THIS TIME...WITH PERIODS OF VSBY BELOW 1SM POSSIBLE
AT THESE TAF LOCATIONS.
AFTER 20Z...A SIGNIFICANT SHORTWAVE WILL MOVE ACROSS. THIS WILL
LIKELY PRODUCE A PERIOD OF LIFR CONDITIONS AT ALL SITES...WHICH
WILL LAST A COUPLE HOURS. VSBY BELOW 1/2SM IS LIKELY.
CONDITIONS WILL IMPROVE WITH THE EXIT OF THIS SHORTWAVE...WITH
MAINLY MVFR CONDITIONS OVERNIGHT. THE EXCEPTION WILL BE IN LAKE
EFFECT BANDS...BUT IN THE WNW FLOW THESE TYPICALLY HAVE ONLY MINOR
IMPACTS ON TAF SITES...THOUGH LOCAL AND BRIEF PERIODS OF LOWER
CONDITIONS ARE POSSIBLE.
OUTLOOK...
MONDAY...MVFR/IFR IN DIMINISHING LAKE SNOWS EAST OF THE LAKES...
MAINLY VFR ELSEWHERE.
MONDAY NIGHT...IFR WITH LIGHT SNOW LIKELY.
TUESDAY...IFR WITH LIGHT SNOW LIKELY EAST OF LAKE ONTARIO...
ELSEWHERE IMPROVING TO MAINLY VFR.
WEDNESDAY...VFR/MVFR WITH A CHANCE OF RAIN SHOWERS.
THURSDAY...VFR/MVFR WITH A CHANCE OF SNOW SHOWERS.
&&
.MARINE...
MODERATELY STRONG SOUTHWESTERLIES AND WESTERLIES WILL CONTINUE
ACROSS THE LOWER LAKES REGION RIGHT INTO MONDAY. THIS WILL RESULT
IN CONDITIONS REMAINING SOLIDLY IN THE SMALL CRAFT ADVISORY RANGE
THROUGH MONDAY MORNING...BEFORE AN APPROACHING WARM FRONT RESULTS
IN DIMINISHING WINDS MONDAY AFTERNOON AND EVENING.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST MONDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY UNTIL NOON EST TODAY FOR LEZ020.
SMALL CRAFT ADVISORY UNTIL 4 PM EST MONDAY FOR
LOZ042>045.
&&
$$
SYNOPSIS...JJR
NEAR TERM...APFFEL/JJR
SHORT TERM...HITCHCOCK
LONG TERM...HITCHCOCK
AVIATION...APFFEL/JJR
MARINE...APFFEL/JJR
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
918 AM MST SUN JAN 29 2012
.UPDATE...
&&
.AVIATION...VFR THRU TONIGHT WITH ONLY SOME MID AND HIGH LEVEL
CLOUDINESS. LATEST RUC AND HRRR DISAGREE SOMEWHAT ON WIND
DIRECTIONS BY MID TO LATE AFTN. THE RUC SHOWS SSW WINDS BECOMING
WNW BY 18Z AND THEN KEEPS THE SAME DIRECTION THRU THE AFTN WHILE
THE HRRR SHOWS A WEAK LONGMONT ANTICYCLONE DEVELOPING WITH WNW
WINDS BECOMING LIGHT ELY BY 22Z. FOR NOW WILL KEEP A WNW DIRECTION
LIKE THE RUC SHOWS FOR THE AFTN HOURS.
&&
.PREV DISCUSSION... /ISSUED 335 AM MST SUN JAN 29 2012/
SHORT TERM...WILL SEE A WARMER BUT LESS BREEZY DAY TODAY AS AN
UPPER RIDGE OVER THE SOUTHWEST MOVES SLIGHTLY EAST TO ADVECT IN
WARMER TEMPERATURES. THIS WILL PRODUCE TEMPERATURES ABOUT 10 TO
15 DEGREES WARMER THAN YESTERDAY. HIGH LEVEL MOISTURE IN THE FORM
OF CIRRUS CLOUDS ARE MOVING OVER THE STATE FROM THE PACIFIC
NORTHWEST. EXPECT PERIODS OF HIGH CLOUDS THROUGH THE DAY INCLUDING
A DEVELOPING WAVE CLOUD THIS AFTERNOON. A SLIGHT INCREASE IN
MOISTURE WILL KEEP HUMIDITIES SLIGHTLY HIGHER THAN YESTERDAY AND
WINDS ARE EXPECTED TO BE SLIGHTLY LESS THAN YESTERDAY FOR THE
PLAINS. THEREFORE NO FIRE WEATHER HIGHLIGHTS ARE NEEDED FOR TODAY.
A STABLE LAYER AT MOUNTAIN TOP AND TIGHT PRESSURE GRADIENT IS
PRODUCING STRONG AND GUSTY WINDS OVER THE HIGHER TERRAIN DOWN
INTO THE FOOTHILLS THIS MORNING. THIS WIND IS EXPECTED TO
DECREASE THROUGH THE DAY BUT SHOULD STILL SEE GUSTS IN THE 25 TO
40 MPH RANGE AS A LEESIDE SURFACE TROUGH REMAINS.
LIGHTER BUT STILL BREEZY WEST WINDS TONIGHT ALONG WITH WARMER AIR
ADVECTED ALOFT WILL MODERATE MINIMUM TEMPERATURES WITH READINGS IN
THE MID 20S TO MID 30S FOR THE PLAINS AND IN THE TEENS TO NEAR 20
FOR THE MOUNTAINS.
LONG TERM...ANOTHER MILD DAY CAN BE EXPECTED MONDAY WITH WARM MID
LEVEL TEMPS AND BREEZY DOWNSLOPE FLOW. LEE SURFACE TROUGH AND A
MILD START TO THE DAY WILL HELP OFFSET THE INCREASE IN CLOUD
COVER...SO HIGH TEMPS AT OR SLIGHTLY ABOVE 60F ARE FORECAST FOR
THE PLAINS. IN THE HIGH COUNTRY...LOOK FOR A MILD DAY AS WELL
BEFORE WEAK COLD ADVECTION AND INCREASING MOISTURE BRING A CHANCE
OF LIGHT SNOW BY MONDAY NIGHT. THE CURRENT SATELLITE IMAGES ARE
FAIRLY IMPRESSIVE WITH THIS NEXT SHORT WAVE...BUT MODELS DO NOT
INDICATE MUCH MOISTURE REACHING COLORADO. THERE IS SOME WEAK Q-G
VERTICAL MOTION...SO THINK THE MODELS MAY BE A BIT TOO DRY
ESPECIALLY CONSIDERING THE CURRENT SATELLITE PICS. HOWEVER...ANY
SNOW THAT DOES FALL SHOULD BE LIGHT WITH ALMOST DUE WESTERLY
OROGRAPHIC FLOW.
ON TUESDAY...WE EXPECT SOME DRYING IN THE HIGH COUNTRY IN BETWEEN
WEATHER SYSTEMS. BY TUESDAY NIGHT AND WEDNESDAY...MODELS SOLUTIONS
DIFFER SIGNIFICANTLY WITH TIMING AND INTENSITY OF SHORT WAVES AND
CONSIDERABLE RUN TO RUN DISCREPANCIES EXIST. AS A RESULT...FORECAST
CONFIDENCE IN TIMING THESE IS LACKING SO A PROLONGED PERIOD OF
CONSERVATIVE POPS FOR THE HIGH COUNTRY IS REASONABLE. THE BEST
CHANCE SEEMS TO BE CENTERING ON WEDNESDAY NIGHT INTO THURSDAY WITH
POTENTIAL FOR A STRONGER SHORT WAVE DROPPING ACROSS THE FORECAST
AREA IN DEVELOPING NORTHWEST FLOW ALOFT. TEMPERATURES WILL STILL
AVERAGE A FEW DEGREES ABOVE NORMAL TUESDAY AND WEDNESDAY...WITH
COOLER READINGS EXPECTED BY THURSDAY WITH STRONGER COLD ADVECTION
NOTED IN MOST MEDIUM RANGE MODEL SOLUTIONS. LATEST TRENDS ARE
POINTING TOWARD A DEEPER TROUGH...WHICH MAY BE ENOUGH TO BRING A
CHANCE OF SNOW TO THE PLAINS.
AFTER THAT TROUGH...A LARGE AND WARM RIDGE IS EXPECTED TO BUILD
OVER THE CENTRAL ROCKIES. THE WARMUP MAY TAKE A COUPLE DAYS WITH
COLD AIR EAST OF THE ROCKIES GRADUALLY ABATING...BUT ABOVE NORMAL
TEMPS WILL LIKELY RETURN BY NEXT WEEKEND.
AVIATION...
VFR CONDITIONS EXPECTED THROUGH MONDAY WITH ONLY HIGH LEVEL
CLOUDS. GUSTY WEST WINDS ARE EXPECTED TO CONTINUE OVER KBJC AND
AT TIMES KDEN AS THE MOUNTAIN WAVE PATTERN AND TIGHT SURFACE
PRESSURE GRADIENT REMAINS THIS MORNING. SHOULD SEE THESE WINDS
RELAX THROUGH THE DAY AS THE GRADIENT DECREASES. WESTERLY
COMPONENT TO WINDS WILL DOMINATE THROUGH MONDAY AS A LEE SURFACE
TROUGH REMAINS OVER THE EASTERN PLAINS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KRIEDERMAN
LONG TERM....BARJENBRUCH
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS NEW YORK NY
509 PM EST SUN JAN 29 2012
.SYNOPSIS...
A COLD FRONT PASSES THROUGH LATE TONIGHT. HIGH PRESSURE RETURNS ON
MONDAY. A WARM FRONT APPROACHES MONDAY NIGHT AND LIFTS NORTH OF
THE AREA TUESDAY MORNING. A COLD FRONT APPROACHES THE AREA
WEDNESDAY AND THEN MOVES THROUGH WEDNESDAY NIGHT. HIGH PRESSURE
BUILDS IN BRIEFLY ON THURSDAY. UNSETTLED FOR THURSDAY NIGHT
THROUGH SUNDAY WITH POTENTIAL IMPACTS FROM SEVERAL STORM SYSTEMS.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
INCREASING PRESSURE GRADIENT BETWEEN HIGH OFFSHORE AND LOW
APPROACHING FROM GREAT LAKES. POTENT SHORTWAVE ALOFT WITH 500 MB
VORT MAX AXIS MOVING THROUGH THE REGION LATE THIS EVENING AND THEN
EXITING TO THE EAST LATER OVERNIGHT. CLOUDS THICKEN AND LOWER THIS
EVENING AHEAD OF A COLD FRONT AT THE SURFACE. THE FRONT IS
FORECAST TO MOVE THROUGH SHORTLY AFTER MIDNIGHT. LOW LEVEL JET
INCREASES QUITE A BIT WITH 925 MB WINDS OF 40 TO 45 KT MOVING
ACROSS JUST AHEAD OF THE FRONT WITH BEST MIXING OVER THE WATER.
MAX WINDS LOOK TO BE GENERALLY 4Z TO 8Z...WITH WIND GUSTS MOSTLY
NEAR 30 MPH OVER LAND.
CONCERNING POPS...THE FORCING FROM THE SHORTWAVE ALONE KEEPS THE
FORECAST AT CHANCE...BUT NOT ANY HIGHER CONSIDERING THE DRY LOW
LEVELS AND MODEL SOLUTIONS. THE LARGE LIFTED INDEX TENDENCY AND
STEEPER LAPSE RATES IN THE LOWER LEVELS GO INTO THE FORCING
FACTORS. PRECIP TYPE WILL BE MAINLY SNOW SHOWERS NORTH AND WEST
OF NEW YORK CITY AND RAIN SHOWERS MIXING WITH SNOW SHOWERS FOR THE
REMAINDER OF THE AREA. THERE IS A CHANCE SNOW SHOWERS COULD BE
LOCALLY MODERATE TO HEAVY IN THE FORM OF SNOW SQUALLS BUT WILL BE
QUITE BRIEF IN DURATION. THIS IS MAINLY ACROSS THE COLDER
LOCATIONS IN LOWER HUDSON VALLEY...INTERIOR NORTHEAST NEW JERSEY
AND INTERIOR SOUTHWEST CONNECTICUT. JUST HAVE A FEW TENTHS OF AN
INCH OF SNOW IN NORTHERN ORANGE WHERE CONFIDENCE IS A BIT HIGHER
WITH SNOWFALL BUT IN THOSE OTHER LOCATIONS MENTIONED
PREVIOUSLY...COULD ALSO HAVE A QUICK COATING OF SNOW. MESOSCALE
MODELS OF NSSL WRF AND HRRR DEPICT A DETERIORATING LINE OF
REFLECTIVITY REPRESENTING THE SHOWERS APPROACHING LATER THIS
EVENING AND MOVING THROUGH BETWEEN 4 AND 8Z. AGAIN...THIS IS A
QUICK DURATION AND THINKING THAT IF TURNS OUT THIS LINE OF SHOWERS
IS LONGER LIVED AND STRONGER MORE PLACES COULD GET A QUICK COATING
OF SNOW...MAINLY ON THE GRASSY SURFACES WITH SOME QUICK 1 INCH
SNOW AMOUNTS MAINLY ON HIGHER ELEVATIONS. HOWEVER...CONFIDENCE IS
NOT THAT HIGH WITH MODEL POPS BEING SO LOW.
MODEL QPF FIELDS ARE VERY LOW THOUGH ON THE ORDER OF JUST A FEW
HUNDREDTHS OF AN INCH AND AGAIN DRY LOW LEVELS WILL ACT TO
DIMINISH THE PRECIP COMING IN FROM THE WEST.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
WINDS WILL BE DECREASING AS THE LOW PUSHES TO THE EAST OFFSHORE AND
SOUTH OF NOVA SCOTIA ON MONDAY. DRIER AIR MOVES INTO PLACE AS HIGH
PRESSURE FROM THE SOUTH WILL BE BUILDING IN WITH SOME RIDGING.
HOWEVER...COLDER 850 TEMPS DOWN TO -9 TO -13 C LEAD TO A GREATER
WEIGHT OF THE COLDER MET GUIDANCE FOR HIGH TEMPS. IN
ADDITION...LESS VERTICAL MIXING IS EXPECTED THAN TODAY WITH MIXING
UP TO A LITTLE ABOVE 850 HPA. FLOW ALOFT BECOMES QUASI-ZONAL.
MONDAY NIGHT...AN APPROACHING WARM FRONT FROM THE WEST WILL MOVE
INTO THE AREA. MOST PRECIP WILL BE IN THE FORM OF SNOW SHOWERS
MOSTLY IN THE NORTHERN ZONES. QPF AGAIN IS ONLY ON THE ORDER OF A
FEW HUNDREDTHS OF AN INCH AND FORCING IS EVEN WEAKER THAN FORCING
TONIGHT. THEREFORE...JUST LEFT SLIGHT CHANCE POPS.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
WARM FRONT LIFTS NORTH OF THE AREA EARLY TUESDAY WITH UNSEASONABLY
MILD TEMPS EXPECTED FOR TUESDAY AND WEDNESDAY. CHANCE OF SHOWERS
BEGINNING LATE TUESDAY NIGHT AS A COLD FRONT APPROACHES...WITH THE
BEST CHANCE FOR RAIN ARRIVING WEDNESDAY AFTERNOON AHEAD OF THE
FRONT. COLD FRONT PASSAGE EXPECTED OVERNIGHT WEDNESDAY...WITH COOLER
BUT STILL ABOVE AVERAGE TEMPS ON THURSDAY.
AFTER THURSDAY...THE PICTURE BECOMES MUCH LESS CERTAIN WITH WIDE
DIVERGENCE IN MODEL SOLUTIONS CONTINUING. ECMWF HAS COME IN EVEN
QUICKER WITH ITS HANDLING OF A SURFACE LOW MOVING OUT OF THE OHIO
VALLEY...LATEST RUN MOVES THE LOW JUST SOUTH OF THE AREA THURSDAY
NIGHT AND DEEPENS IT EAST OF THE AREA ON FRIDAY. THIS SYSTEM IS
FOLLOWED BY A COLDER SYSTEM WITH SECONDARY COASTAL LOW DEVELOPMENT
STARTING LATE SUNDAY. THE CURRENT CANADIAN RUN MOVES A PRECIP SHIELD
INTO THE AREA ON SATURDAY AHEAD OF A SOUTHERN STREAM LOW OVER THE
MISSISSIPPI VALLEY AND DEVELOPING SECONDARY LOW. THE OPERATIONAL GFS
IS DRY OVER THE SAME PERIOD WITH SURFACE LOWS PASSING TO THE SOUTH
AND EAST OF THE AREA ON FRIDAY AND SUNDAY. KEPT HIGHEST POPS IN FOR
SATURDAY CLOSER TO PREVIOUS ECWMF RUNS AND AS A NOD TO THE CANADIAN
SOLUTION. THIS IS EMPHATICALLY A LOW CONFIDENCE FORECAST FOR THE
THURSDAY NIGHT THROUGH SUNDAY PERIOD.
&&
.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
RIDGE OF HIGH PRESSURE TO THE EAST WEAKENS AS A COLD FRONT
APPROACHES THROUGH EARLY THIS EVENING. THE FRONT CROSSES THE
TERMINALS FROM ABOUT 05Z THROUGH 10Z. HIGH PRESSURE BUILDS BEHIND
THE FRONT MONDAY.
VFR THROUGH THE TAF PERIOD. MAINLY DRY...HOWEVER THERE IS A CHANCE
OF SCATTERED SNOW SHOWERS WITH THE FRONT. BEST CHANCE WILL BE AT
KSWF WHERE LOW END VFR TO HIGH END MVFR CONDITIONS WILL BE POSSIBLE
FROM 05Z TO 08Z.
GUSTY SOUTHWESTERLY WINDS SHIFT BACK TO WEST WITH THE PASSAGE OF THE
FRONT...AND GUSTS INCREASE FOR A TIME...NEARING 30 KTS. SOME
UNCERTAINTY WITH THE TIMING OF THE WIND SHIFT AND MAY BE AN HOUR OR
SO EITHER SIDE OF THE FORECAST TIME.
OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...
MONDAY THROUGH TUESDAY...VFR. GUSTY WESTERLY WINDS MONDAY.
WEDNESDAY...SUB-VFR POSSIBLE IN RAIN.
THURSDAY...VFR.
FRIDAY...LOW CHANCE OF SUB VFR.
&&
.MARINE...
GALES EXPECTED TO DEVELOP BETWEEN 0Z AND 6Z MON ACROSS THE WATERS
AND THEN DIMINISH TOWARDS MONDAY MORNING AS LOW PRESSURE
APPROACHES FROM THE WEST. HIGHEST WINDS AND SEAS EXPECTED NEAR
AND SHORTLY AFTER MIDNIGHT WITH BEST LOW TO MID LEVEL FORCING NEAR
THAT TIME. SCA THEREAFTER LATER ON MONDAY AS LOW PULLS AWAY
OFFSHORE.
SCA LEVEL SEAS FOR THE ATLANTIC ZONES EXPECTED ON TUESDAY WITH
STRONG SOUTHERLY FLOW FOLLOWING WARM FRONTAL PASSAGE. SEAS MAY
BRIEFLY SUBSIDE BELOW SCA CRITERIA TUESDAY NIGHT INTO WEDNESDAY
BEFORE BUILDING BACK LATE WEDNESDAY AHEAD OF A COLD FRONT. ROUGH
SEAS CONTINUING WEDNESDAY NIGHT INTO THURSDAY MORNING FOLLOWING COLD
FRONT PASSAGE...BEFORE DIMINISHING LATE THURSDAY AND FRIDAY.
&&
.HYDROLOGY...
ANY LIQUID EQUIVALENT PRECIPITATION THROUGH WEDNESDAY IS EXPECTED
TO BE GENERALLY LESS THAN A TENTH OF AN INCH ON AVERAGE.
&&
.EQUIPMENT...
THE WEATHER OBSERVATION FROM CENTRAL PARK WILL BE UNAVAILABLE
UNTIL FURTHER NOTICE. THIS IS DUE TO A SIGNIFICANT POWER
INTERRUPTION TO THE CENTRAL PARK AUTOMATED SURFACE OBSERVING
STATION /ASOS/ AND BACKUP STATION. UTILITY WORKERS ARE ADDRESSING
THE PROBLEM...BUT THERE IS CURRENTLY NO ESTIMATED TIME FOR RETURN
TO SERVICE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...GALE WARNING UNTIL 6 AM EST MONDAY FOR ANZ330-335-338-340-345-
350-353-355.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ330-
340-350-353.
&&
$$
SYNOPSIS...JM/MAS
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...MAS
AVIATION...MET
MARINE...JM/MAS
HYDROLOGY...JM
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS ALBANY NY
419 PM EST SUN JAN 29 2012
.SYNOPSIS...
A FAST MOVING CLIPPER TYPE SYSTEM WILL BRING SOME SNOW TO A GOOD
PORTION OF OUR REGION TONIGHT WITH SOME GUSTY WINDS AND SNOW
SQUALLS ALSO POSSIBLE. A WEAK RIDGE OF HIGH PRESSURE WILL BUILD
INTO THE REGION ON MONDAY. THIS WILL BE FOLLOWED BY A WARM FRONT
WHICH WILL APPROACH OUR REGION FROM THE SOUTHWEST MONDAY NIGHT...
BRINGING ANOTHER ROUND OF SNOW TO OUR REGION MONDAY NIGHT INTO
TUESDAY MORNING.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 4 PM EST...FIRST BATCH OF SNOW MOVING THROUGH THE
ADIRONDACKS WITH THE FIRST BOUNDARY WITH THE MAIN EVENT YET TO
FOLLOW AS THE LEADING EDGE OF SNOW AHEAD OF THE CLIPPER SYSTEM
MOVING INTO WESTERN NEW YORK. THE WINTER WEATHER ADVISORY
CONTINUES FOR THE WESTERN ADIRONDACKS AND WESTERN MOHAWK VALLEY
UNTIL 10 AM MONDAY MORNING. EXPECT SNOWFALL AMOUNTS RANGING FROM 3
TO 8 INCHES IN THE ADVISORY AREA ALONG WITH BLOWING SNOW AS WEST
TO NORTHWEST WINDS OF 10 TO 20 MPH WITH GUSTS UP TO 25 MPH WILL BE
COMMON WITH HIGHER GUSTS POSSIBLE WITH SOME SNOW SQUALLS LATER
THIS EVENING. THIS CLIPPER TYPE SYSTEM HAS SOME FAIRLY GOOD
DYNAMICS WITH IT INCLUDING A STRONG VORT AXIS AND LATEST IR SAT
PICS ARE INDICATING COOLING CLOUD TOPS. THERE ALSO COULD BE SOME
EMBEDDED SNOW SQUALLS THIS EVENING AND EVEN AN ISOLATED CHC OF
SOME THUNDER SNOW ESPECIALLY CLOSER TO LAKE ONTARIO AS THE
SHOWALTER INDICES BRIEFLY GET BELOW ZERO. BOTH THE HIRESWRF MODEL
COMPOSITE REFLECTIVITY AND THE HRRR COL MAX REFLECTIVITY HAVE
REFLECTIVITY VALUES INDICATIVE OF SNOW SQUALLS DURING THE LATE
EVENING TO AROUND MIDNIGHT TIME FRAME. IF THESE SNOW SQUALLS
BECOME MORE CERTAIN SPS WILL LIKELY BE ISSUED. LOWS TONIGHT ARE
EXPECTED TO RANGE FROM THE MID TO UPPER TEENS NORTHWEST TO UPPER
20S SOUTHEAST.
LATE TONIGHT AND MONDAY...IN THE WAKE OF THE CLIPPER TYPE SYSTEM
A LAKE EFFECT BAND WILL SET UP WHICH WILL INITIALLY BE ORIENTED
TOWARD THE WESTERN ADIRONDACKS AND THEN SLIDE SOUTHEASTWARD INTO
THE MOHAWK VALLEY. AS THIS BAND WILL BE SHORT LIVED WITH A RIDGE
OF HIGH PRESSURE BUILDING QUICKLY INTO THE REGION BY
LATE MORNING...EXPECT THE GREATEST ACCUMULATIONS WILL BE ACROSS
SOUTHERN PORTIONS WESTERN ADIRONDACKS AND THE WESTERN MOHAWK
VALLEY. THIS ADDITIONAL SNOW IN THE WESTERN MOHAWK VALLEY SHOULD
BE ENOUGH TO RESULT IN THE AREA AVERAGING OVER 4 INCHES OF SNOW
WHEN COUPLED WITH THE SNOW FROM THE CLIPPER TYPE SYSTEM. BY MONDAY
AFTERNOON THE RIDGE OF HIGH PRESSURE IS ALREADY CRESTING ACROSS
THE FA AND THEN SLIDING EAST OF THE FA BY EVENING. EXPECT HIGHS ON
MONDAY TO RANGE FROM THE LOW TO MID 20S NORTHWEST TO MID TO UPPER
30S SOUTHEAST.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
MONDAY NIGHT INTO TUESDAY MORNING THE FA IS EXPECTED TO BE
IMPACTED BY A WARM FRONT LIFTING NE FROM THE OHIO VALLEY. LIGHT
SNOW IS EXPECTED TO OVERSPREAD MUCH OF THE FA FROM SOUTHWEST TO
NORTHEAST MONDAY EVENING WITH THE HIGHEST QPF FROM THE MOHAWK
VALLEY NORTH IN NEW YORK AND ACROSS SOUTHERN VERMONT. THIS EVENT
GENERALLY LOOKS LIKE 2 TO 4 INCHES TOTAL ACROSS NORTHWEST PORTIONS
OF THE FA WITH MOST OTHER AREAS HAVING AROUND AN INCH OF
SNOW...ALTHOUGH THE MOUNTAINS EITHER SIDE OF THE GREATER CAPITAL
DISTRICT MAY PICK UP A COUPLE OF INCHES. EXPECT LOWS MONDAY NIGHT
TO BE IN THE MID TEENS TO MID 20S.
TUESDAY AFTERNOON INTO TUESDAY NIGHT EXPECT THE WARM FRONT TO BE
NORTH OF THE BULK OF THE FA BY TUESDAY EVENING WITH THE FA LEFT IN
THE WARM SECTOR. THERE WILL STILL BE A CHANCE OF PCPN TUESDAY
AFTERNOON INTO TUESDAY NIGHT MAINLY ACROSS THE NORTHERN HALF OF
THE FA UNTIL THE COLD FRONT ARRIVES ON WEDNESDAY. EXPECT HIGHS ON
TUESDAY TO RANGE FROM THE MID 30S NORTHWEST TO UPPER 40S TO AROUND
50 SOUTHEAST WITH LOWS TUESDAY NIGHT RANGING FROM THE UPPER 20S TO
LOWER 30S NORTH TO MID 30S SOUTH.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE EXTENDED FORECAST STARTS OUT VERY MILD MID WEEK...AND THEN
BECOMES VERY UNSETTLED WITH CONTINUED MEDIUM RANGE DETERMINISTIC AND
ENSEMBLE MODEL UNCERTAINTY...WITH A LOW CONFIDENCE FORECAST FROM
THURSDAY INTO WEEKEND. WE WENT CLOSE TO THE HPC GUIDANCE...HOWEVER
THE LATEST 12Z ECMWF WOULD INDICATE THAT TWO SEPARATE SYSTEMS IN THE
W/SW FLOW COULD IMPACT THE NORTHEAST THU NIGHT THROUGH FRIDAY...AND
ANOTHER SYSTEM LATER ON THE WEEKEND WITH SOME SNOW. THE CANADIAN
GGEM IS ALSO HINTING AT ANOTHER SYSTEM DEVELOPING SATURDAY NEXT
WEEKEND OVER THE CNTRL MS RIVER VALLEY THAT COULD IMPACT THE
NORTHEAST FOR SUNDAY TOO. MEANWHILE...THE GFS IS COLD AND DRY LATE
IN THE WEEK WITH A SHORT-WAVE TROUGH IN THE NW FLOW THAT COULD
PRODUCE SOME SOME SNOW SHOWERS LATER NEXT WEEKEND.
WED-WED NIGHT...HIGH PRESSURE RETREATS OFF THE MID ATLANTIC
COAST...AS A WAVE OF LOW PRESSURE MOVES ACROSS SRN QUEBEC. MOST OF
THE FCST AREA GETS INTO A WARM SECTOR WITH H850 TEMPS JUMPING UP TO
+1 TO +5C. MAX TEMPS COULD BE 10 TO 20 DEGREES ABOVE NORMAL WITH
HIGHS IN THE M40S TO L50S IN THE VALLEYS...AND LOWER TO M40S OVER
THE HILLS AND MTNS. THE COLD FRONT QUICKLY APPROACHES LATE IN THE
DAY INTO THE EVENING WITH A GOOD CHANCE OF SHOWERS...TRANSITIONING
TO SNOW SHOWERS WITH THE COLD AIR ADVECTION. WE KEPT THE TREND OF
LIKELY POPS NORTH OF THE CAPITAL REGION CLOSER TO THE BETTER
CONVERGENCE AND LIFT WITH THE WAVE AND FRONT. LOWS WILL RANGE FROM
THE LOWER TO M20S OVER THE MTNS...AND U20S TO L30S IN THE VALLEYS.
THU-THU NIGHT...THE GFS HAS HIGH PRESSURE BUILDING IN FROM SRN
QUEBEC WITH A BROAD LONGWAVE TROUGH OVER THE NRN TIER. THE ECMWF
HAS A SHORT-WAVE IN THE SRN STREAM PHASING INTO THE NRN STREAM NEAR
THE CNTRL MS RIVER VALLEY...AND MOVES IT INTO THE OHIO VALLEY BY
THURSDAY MORNING. THIS SYSTEM MOVES ALONG THE BAROCLINIC ZONE FROM
THE FRONTAL PASSAGE ON WED NIGHT. THE SFC WAVE MOVES NORTHEAST INTO
PA AND UPSTATE NY BY LATE IN THE DAY ON THU VIA THE ECMWF. THE HPC
GUIDANCE...AND GFS HAVE A SECONDARY COLD FRONT SLIP SOUTH OF THE
REGION DURING THE DAY...AND THE WAVE IS MUCH FLATTER PASSING SOUTH
OF THE REGION. WE KEPT MUCH OF THE DAY DRY ON THU WITH HIGH
PRESSURE IN CONTROL. WE DID ADD A SLIGHT CHC OF SNOW THU NIGHT
OVER MOST OF THE REGION IN THE GRIDDED FCST JUST IN CASE THE ECMWF
IS CORRECT HERE. LATER RUNS OF THE GFS COULD TREND FURTHER NORTHWARD
WITH THE ACTIVE W/SW FLOW ALOFT.
FRI-FRI NIGHT...THIS IS WHERE THE MEDIUM RANGE GUIDANCE CONTINUES TO
DIVERGE. THE HPC GUIDANCE AND GFS HAVE A COLD FRONT MOVING SOUTH
WITH HIGH PRESSURE RIDGING BACK IN WITH A NRN STREAM DISTURBANCE
DIGGING S/SE FROM THE UPPER MIDWEST. THE SUBTROPICAL JET/SRN STREAM
DISTURBANCE IS EJECTING OUT OF TX. WE KEPT SOME SLIGHT OR LOW CHC
POPS IN FOR SNOW SHOWERS OR LIGHT SNOW DURING THIS TIME FRAME WITH
THE FIRST WAVE MOVING INTO GULF OF MAINE AND THE CANADIAN
MARITIMES. THE ECMWF/CANADIAN GGEM/SOME GLOBAL ENSEMBLES MEMBERS
HAVE A AN IMPRESSIVE SYSTEM FORMING OVER THE SRN PLAINS/LOWER MS
RIVER VALLEY FRI NIGHT WITH A POSITIVELY TILTED LONGWAVE TROUGH
BEING CARVED OUT OVER THE CNTRL PLAINS.
SAT-SUN...VERY LOW CONFIDENCE FORECAST CONTINUES. CAN GGEM AND
ECMWF CONTINUES TO HAVE COASTAL WAVE MOVING NORTHEAST INTO MID
ATLANTIC REGION...AND SOUTH OF LONG ISLAND BY SUNDAY. THE 18Z HPC
GUIDANCE IS TRENDING FURTHER NORTH LATE SAT INTO SUNDAY WITH THE
WAVE. WE KEPT SLIGHT TO LOW CHC POPS IN FOR THE WEEKEND WITH SNOW
AS THE MAIN PTYPE /AS SUFFICIENTLY COLD ENOUGH AIR IS IMPLIED/. THE
TIMING AND EVOLUTION OF THE LATE WEEK INTO THE WEEKEND SYSTEMS IS
VERY UNCERTAIN. IT COULD BE VERY ACTIVE. TEMPS LOOK TO AVERAGE
NEAR NORMAL FOR FEBRUARY DURING THIS STRETCH.
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
HIGH PRESSURE IS BRIEFLY RIDGING IN FROM THE SOUTH THIS
AFTERNOON...BUT A STRONG UPPER LEVEL DISTURBANCE ASSOCIATED WITH A
CLIPPER LOW IS APPROACHING FROM THE LOWER GREAT REGION. THE CLIPPER
AND ITS COLD FRONT WILL QUICKLY MOVE ACROSS ERN NY AND WRN NEW
ENGLAND TONIGHT. HIGH PRESSURE WILL BRIEFLY BUILD IN FROM SOUTHERN
QUEBEC FOR MONDAY.
VFR CONDITIONS ARE EXPECTED TO LAST INTO THE EARLY EVENING WITH
THICKENING CIRRUS AND A HIGH STRATUS DECK AT 5-6 KFT AGL AHEAD OF
THE CLIPPER. THE BEST CHANCE OF SNOW SHOWERS OR ISOLD SNOW SQUALLS
IMPACTING ANY TERMINALS WILL BE NORTH OF KALB TOWARD KGFL. WE
INCLUDED A PERIOD OF AT LEAST MVFR CONDITIONS THERE BTWN 05Z-09Z. WE
USED VCSH GROUPS STARTING AT 02Z THERE. FURTHER SOUTH WE KEPT A
VCSH GROUP AT KALB. TEMPOS MAY BE ADDED LATER TO ACCOUNT FOR A
BRIEF PERIOD OF MVFR/IFR CONDITIONS WITH ANY SNOW SHOWERS OR
SQUALLS. KPOU LOOKS TO BE FURTHER SOUTH AWAY FROM THE BETTER
CONVERGENCE WITH THE CLIPPER AND COLD FRONT...WHERE IT IS UNCERTAIN
OF ANY REDUCTION BELOW VFR LEVELS OR A VCSH IS NEEDED AT THIS TIME.
THE SNOW SHOWERS...FLURRIES AND ISOLD SQUALLS SHOULD BE EAST OF THE
HUDSON RIVER VALLEY AT 09Z. THE WINDS WILL INCREASE FROM THE W/NW
WITH VFR CONDITIONS AND SCT-BKN CIGS 4-5 KFT AGL.
THE WINDS WILL BE FROM THE W/SW THIS AFTERNOON AT 8-13 KTS WITH A
FEW GUSTS 20-25 KTS...AND THEN BACK TO THE S/SW AT AROUND 10 KTS
AHEAD OF THE CLIPPER. EXPECT THE WINDS TO SHIFT TO THE W/NW AT 8-15
KTS WITH THE COLD FRONTAL PASSAGE SHORTLY AFTER MIDNIGHT...AND
PERSIST INTO THE LATE MORNING. SOME GUSTS TO AROUND 25 KTS WILL BE
POSSIBLE AT KALB THROUGH THE MORNING IN THE WAKE OF THE FRONT.
OUTLOOK...
MON..VFR...SLIGHT CHC -SHSNS KALB-KGFL.
MON NIGHT...VFR/MVFR WITH -SN LIKELY.
TUE...VFR/MVFR AT KGFL WITH -SN LIKELY ESP IN THE MORNING. KALB
SOUTH TO KPOU VFR.
TUE NIGHT-WED...VFR/MVFR. CHC -SHRA/-SHSN.
THU...VFR...SLIGHT CHC -SHRA AT KPOU.
FRI...VFR...SLIGHT CHC -SHRA/-SNSHS.
&&
.HYDROLOGY...
RIVER FLOWS CONTINUE TO RECEDE...ALTHOUGH SOME GAGE SITES REMAIN
IMPACTED BY ICE INCLUDING MCKN6. NO MAJOR PROBLEMS ARE EXPECTED ON
THE RIVERS THROUGH THE MID WEEK PERIOD...OTHER THAN THOSE AREAS
SUCH AS MCKN6 WHERE ICE JAMS ARE STILL A POSSIBILITY. THE
PRECIPITATION THROUGH THE MID WEEK PERIOD IS EXPECTED TO BE MAINLY
IN THE FORM OF SNOW WITH QPF AMOUNTS RANGING FROM A FEW HUNDREDTHS
OF AN INCH TO A QUARTER TO A THIRD OF AN INCH ACROSS NORTHWEST
PORTIONS OF THE HSA.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WINTER WEATHER ADVISORY UNTIL 10 AM EST MONDAY FOR NYZ032-033-
038.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...11
NEAR TERM...11
SHORT TERM...11
LONG TERM...WASULA
AVIATION...WASULA
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS ALBANY NY
127 PM EST SUN JAN 29 2012
.SYNOPSIS...
THE PARADE OF FAST MOVING WEATHER SYSTEMS WILL CONTINUE ACROSS
THE NORTHEAST. HIGH PRESSURE RIDGED ALONG THE MID ATLANTIC COAST
WILL MOVE OFFSHORE THIS AFTERNOON...AS TWO COLD FRONTS WILL MOVE
ACROSS THE REGION THIS EVENING AND OVERNIGHT. ON MONDAY...HIGH
PRESSURE WILL BRIEFLY MOVE OVER THE NORTHEAST...THEN IT WILL SHIFT
OFFSHORE MONDAY NIGHT...AND A WARM FRONT WILL SET UP FROM THE
UPPER GREAT LAKES TO CAPE COD BY TUESDAY...PRODUCING SOME LIGHT
SNOW FOR THE REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1 PM EST...HAVE ISSUED A WINTER WEATHER ADVISORY FOR THE
WESTERN ADIRONDACKS AND WESTERN MOHAWK VALLEY FROM 4 PM THIS
AFTERNOON UNTIL 10 AM MONDAY MORNING. EXPECT SNOWFALL AMOUNTS
RANGING FROM 3 TO 8 INCHES IN THE ADVISORY AREA ALONG WITH BLOWING
SNOW AS WEST TO NORTHWEST WINDS OF 10 TO 20 MPH WITH GUSTS UP TO
25 MPH WILL BE COMMON WITH HIGHER GUSTS POSSIBLE WITH SOME SNOW
SQUALLS LATER THIS EVENING. THE NEXT CLIPPER TYPE SYSTEM HAS SOME
FAIRLY GOOD DYNAMICS WITH IT INCLUDING A STRONG VORT AXIS AND
LATEST IR SAT PICS ARE INDICATING COOLING CLOUD TOPS. THERE ALSO
COULD BE SOME EMBEDDED SNOW SQUALLS THIS EVENING AND EVEN AN
ISOLATED CHC OF SOME THUNDER SNOW ESPECIALLY CLOSER TO LAKE
ONTARIO AS THE SHOWALTER INDICES BRIEFLY GET BELOW ZERO. BOTH THE
HIRESWRF MODEL COMPOSITE REFLECTIVITY AND THE HRRR COL MAX
REFLECTIVITY HAVE REFLECTIVITY VALUES INDICATIVE OF SNOW SQUALLS
DURING THE LATE EVENING TO AROUND MIDNIGHT TIME FRAME. IF THESE
SNOW SQUALLS BECOME MORE CERTAIN SPS WILL LIKELY BE ISSUED.
AS OF 950 AM EST...WE CANCELED THE LAKE EFFECT SNOW ADVISORY FOR
NRN HERKIMER CTY...AS THE BAND AS SHIFTED NORTH OF THE AREA IN THE
BACKING LOW-LEVEL FLOW TO THE SW. THE BAND IS NOW IN THE ST
LAWRENCE RIVER VALLEY. SNOW TOTALS FROM THE LAKE EFFECT AND SNOW
SQUALLS THE PAST 12 TO 15 HOURS HAVE RANGED FROM 3 TO 7 INCHES
WITH SOME ISOLATED HIGHER AMOUNTS POSSIBLE. PLEASE SEE OUR LATEST
PNS STATEMENT.
THE TREND WILL BE FOR A BRIEF BREAK IN THE LATE MORNING INTO THE
EARLY PM FOR MOST OF THE REGION WITH THE RIDGING FROM THE SOUTH.
HOWEVER...ANOTHER POTENT SHORT-WAVE TROUGH IS APPROACHING FROM NRN
IL THIS MORNING. THIS STRONG UPPER LEVEL DISTURBANCE AND ITS
ASSOCIATED COLD FRONT WILL INCREASE THE CHANCE OF SNOW SHOWERS AND
ISOLD SQUALLS FROM WEST TO EAST LATE THIS AFTERNOON INTO THE
OVERNIGHT PERIOD. ONCE AGAIN...BASED ON THE 3-KM REF PRODUCT FROM
THE HRRR AND THE HIRES WRF FAVORS 00Z-03Z. THE HRRR IS FASTER WITH
A 22Z-01Z TIMING WITH THE FIRST BOUNDARY. A SECOND STRONGER
BOUNDARY WITH THE UPPER TROUGH...THE HRRR HAS APPROACHING
BTWN 03Z-06Z FOR THE FCST AREA. WE TRENDED THE SKY COVER TO PARTLY
TO MOSTLY SUNNY FROM THE HUDSON RIVER VALLEY EASTWARD INTO THE
EARLY TO MID PM...BEFORE THE CLOUD INCREASE AHEAD OF THE FIRST
FRONT. MAX TEMPS WILL STILL RUN ABOVE NORMAL WITH U30S TO L40S IN
THE VALLEYS...AND U20S TO M30S OVER THE MTNS. T/TD/RH/APPARENT
TEMP TRENDS WE REDONE BASED ON OBSERVATIONS. THE HIGHEST SNOW
ACCUMULATIONS WITH THIS DISTURBANCE LOOK LIKE THEY WILL BE NORTH
AND WEST OF OF THE CAPITAL REGION WITH 1 TO 4 INCHES POSSIBLE
/ESPECIALLY THE WRN DACKS AND WRN MOHAWK VALLEY/.
PREVIOUS NEAR TERM...
LAKE EFFECT BAND STILL PERSISTENT...AND SHOULD CONTINUE UNTIL WARM
ADVECTION BEGINS LATER THIS MORNING...WHEN THE BAND SHOULD BECOME
DISRUPTED. ALSO SOME ISOLATED SNOW SHOWERS AND FLURRIES STILL INTO
THE SCHOHARIE VALLEY. KEEPING THE SNOW IN THE FORECAST FOR THE
NEXT COUPLE OF HOURS IN THE SCHOHARIE VALLEY AND WESTERN MOHAWK
VALLEY...WHILE KEEPING THE NORTHERN HERKIMER AREA IN BETTER
CHANCES THROUGH THE MORNING. ONE REPORT OF JUST OVER A FOOT
WAS JUST RECEIVED...BUT KEEPING ADVISORY UP AS MOST AREAS SHOULD
SEE 7 INCHES OR LESS.
CLOUD COVER HIGHLY DEPENDENT ON LAKE EFFECT MOISTURE THIS MORNING
BUT THERE SHOULD BE LESS CLOUD COVER ONCE THE LAKE EFFECT BAND IS
DISRUPTED THIS AFTERNOON. SO...JUST SOME MINOR ADJUSTMENTS TO SKY
COVER AND TEMPERATURES THROUGH THIS MORNING.
PREV AFD BELOW...
LAKE EFFECT BAND STILL EXTENDING INTO THE WESTERN MOHAWK VALLEY AND
SOUTHERN ADIRONDACKS. IT IS A BIT CELLULAR AS THE DEPTH OF THE
MOISTURE AND INSTABILITY IS RELATIVELY DEEP...EVIDENT IN THE 00Z BUF
SOUNDING. THE BAND SHOULD CONTINUE TO BRING SNOW INTO THE AREA
THROUGH THE EXPIRATION OF THE WINTER WEATHER ADVISORY. SOME ISOLATED
REFLECTIVITIES ARE RESPECTABLE BUT BASED ON THERMAL PROFILES AND THE
RAPIDLY CHANGING CHARACTER OF THE BAND...SNOW RATIOS AND DURATION OF
HEAVIEST SNOW SEEMS TO SUGGEST SNOW SHOULD STAY WITHIN THE ADVISORY
RANGE. SNOWFALL AMOUNTS STILL LOOK TO BE UP TO 7 INCHES. SOME
ISOLATED SNOW SHOWER ACTIVITY ALSO EXTENDING INTO THE SCHOHARIE
VALLEY THROUGH THE EARLY MORNING HOURS BUT LIGHTER AND MORE
SCATTERED THAN THE SINGLE BAND TO THE NORTH.
WARM ADVECTION WILL BEGIN BY LATE MORNING...SO THE SINGLE BAND AND
THE SCATTERED ACTIVITY TO THE SOUTH IN THE SCHOHARIE VALLEY SHOULD
GET DISRUPTED AROUND OR SHORTLY AFTER SUNRISE. THERE SHOULD BE SOME
PERIODS OF SUN THROUGH AT LEAST THE MORNING...MAYBE INTO THE
AFTERNOON...ESPECIALLY IN EASTERN AREAS...DEPENDING ON HOW QUICKLY
THE NEXT SYSTEM APPROACHES FROM THE GREAT LAKES. BASED ON MIXING
POTENTIAL TODAY...HIGHS IN THE UPPER 30S TO MID 40S BEFORE CLOUD
COVER ARRIVES. HIGHS IN THE LOWER TO MID 30S IN THE SOUTHERN
ADIRONDACKS AND SOUTHERN GREEN MOUNTAINS.
NEXT QUICK MOVING NORTHERN STREAM SYSTEM TRACKS THROUGH THE REGION
TONIGHT...WHICH LOOKS TO BE RELATIVELY MOISTURE STARVED...EXCEPT FOR
WHAT COULD BE PICKED UP OFF THE GREAT LAKES. STILL...MOSTLY CLOUDY
MUCH OF THE NIGHT...WITH THE MOST WIDESPREAD SNOW SHOWER ACTIVITY IN
THE WESTERN MOHAWK VALLEY AND SOUTHERN ADIRONDACKS. SCATTERED
ACTIVITY SHOULD MAKE IT INTO MOST OF THE REGION...WITH MORE ISOLATED
ACTIVITY IN THE MID HUDSON VALLEY..SOUTHERN BERKSHIRES AND NW CT.
THERE COULD BE 1 TO 3 INCHES OF SNOW IN THE NORTHERN AREAS WITH
LOCAL DUSTINGS POSSIBLE ACROSS THE REST OF THE REGION. SOME PARTIAL
CLEARING IS POSSIBLE TOWARD SUNRISE...BUT GUSTY WEST TO NORTHWEST
WINDS SHOULD BEGIN AS THE SYSTEM EXITS LATE TONIGHT. LOWS IN THE
20S...BUT A LITTLE HIGHER THAN GUIDANCE NUMBERS DUE TO THE WINDS AND
MIXING. SOME LOWS IN THE TEENS IN THE SOUTHERN ADIRONDACKS.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
BACK DOOR CDFNT PUSHES SOUTH INTO FCA AS 500HPA SHORT WVS MOVE
EAST ACROSS NEW YORK NEW ENG. THIS WILL BRING A BRIEF PERIOD OF
COLD AIR AND REINVIGORATE LK EFFECT BAND INTO TUG HILL/W ADNDKS.
BY MON NT. LATE MONDAY INTO TUES EASTERN TROF DEPARTS...RIDGING
BUILDS FROM GRTLKS TO SE STATES AND A 500HPA SHORT WAVE EJECTS INTO
NORTHERN GREAT PLAINS. THIS SETS UP FRONTOGENESIS AS WMFNT ORGANIZES
DLH-BOS. MONDAY AND MONDAY NIGHTS CLOUDS BLOOM ALL ALONG AND AHEAD OF
IT...AND OVERRUNNING SNOW BREAKS OUT ACROSS THE GRTLKS.
MON NT INTO TUE MORNING THIS -SN SPREADS ACROSS NY/NEW ENG. THE
NAM/GFS/ECMWF ARE SIMILAR BUT NAM QPF IS DEFINITELY LIGHTER. THE
GEM HAS BULK OF PCPN N OF FCA. AS THE 500HPA FLOW TURNS SW THE
MODEL SUIT GENERALLY LIFTS TO WMFNT OUT OF THE FCA TUE
EVNG...LEAVING AREA IN WARM SECTOR WITH -SHRA THREAT TILL CDFNT
MOVES THROUGH WED. THEY ALL TAKE MAJOR CYCLONE WITH THIS SYSTEM
WELL NORTH INTO ONT/QB.
TEMPS ARE GENERALLY ABV NORMAL TO MUCH ABV DURING THIS PERIOD.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
THE FAST MOVING PATTERN CONTINUES WITH A SHORT WV MOVING THROUGH
THUR TRIGGERING ISOLD TO SCT -SHSN...MORE NEAR THE LAKE. HIGH
PRESSURE RIDGES SOUTH TO END THE WEEK WITH DRY CONDS...THEN THE
MODELS TAKE THE BIG DIVERGE. THE GFS PRODUCES A SIGNIFICANT
COASTAL LOW...AS USUAL BASED ON THE PHASING OF SHORT WAVES THAT
ARE SCATTERED ALL OVER EAST ASIA. THE ECMWF TAKES THIS STORM...NOT
UP THE EAST COAST...BUT UP THE ST LAWRENCE VLY. THE MODEL SUITE
HAS BEEN ALL OVER WITH THIS SYSTEM FROM IN THE WEST ATLC. FOR NOW
CARRIED CHC OR SLIGHT CHC. THERE`S 6 DAYS TO THE MODELS TO DEBATE
WITH THEMSELVES HOW THE SHORT WVS WILL PHASE. TEMPS DURING THE EFO
WILL BEGIN ABV NORMALS THU AND END THE PERIOD NEAR NORMAL.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
HIGH PRESSURE IS BRIEFLY RIDGING IN FROM THE SOUTH THIS
AFTERNOON...BUT A STRONG UPPER LEVEL DISTURBANCE ASSOCIATED WITH A
CLIPPER LOW IS APPROACHING FROM THE LOWER GREAT REGION. THE CLIPPER
AND ITS COLD FRONT WILL QUICKLY MOVE ACROSS ERN NY AND WRN NEW
ENGLAND TONIGHT. HIGH PRESSURE WILL BRIEFLY BUILD IN FROM SOUTHERN
QUEBEC FOR MONDAY.
VFR CONDITIONS ARE EXPECTED TO LAST INTO THE EARLY EVENING WITH
THICKENING CIRRUS AND A HIGH STRATUS DECK AT 5-6 KFT AGL AHEAD OF
THE CLIPPER. THE BEST CHANCE OF SNOW SHOWERS OR ISOLD SNOW SQUALLS
IMPACTING ANY TERMINALS WILL BE NORTH OF KALB TOWARD KGFL. WE
INCLUDED A PERIOD OF AT LEAST MVFR CONDITIONS THERE BTWN 05Z-09Z. WE
USED VCSH GROUPS STARTING AT 02Z THERE. FURTHER SOUTH WE KEPT A
VCSH GROUP AT KALB. TEMPOS MAY BE ADDED LATER TO ACCOUNT FOR A
BRIEF PERIOD OF MVFR/IFR CONDITIONS WITH ANY SNOW SHOWERS OR
SQUALLS. KPOU LOOKS TO BE FURTHER SOUTH AWAY FROM THE BETTER
CONVERGENCE WITH THE CLIPPER AND COLD FRONT...WHERE IT IS UNCERTAIN
OF ANY REDUCTION BELOW VFR LEVELS OR A VCSH IS NEEDED AT THIS TIME.
THE SNOW SHOWERS...FLURRIES AND ISOLD SQUALLS SHOULD BE EAST OF THE
HUDSON RIVER VALLEY AT 09Z. THE WINDS WILL INCREASE FROM THE W/NW
WITH VFR CONDITIONS AND SCT-BKN CIGS 4-5 KFT AGL.
THE WINDS WILL BE FROM THE W/SW THIS AFTERNOON AT 8-13 KTS WITH A
FEW GUSTS 20-25 KTS...AND THEN BACK TO THE S/SW AT AROUND 10 KTS
AHEAD OF THE CLIPPER. EXPECT THE WINDS TO SHIFT TO THE W/NW AT 8-15
KTS WITH THE COLD FRONTAL PASSAGE SHORTLY AFTER MIDNIGHT...AND
PERSIST INTO THE LATE MORNING. SOME GUSTS TO AROUND 25 KTS WILL BE
POSSIBLE AT KALB THROUGH THE MORNING IN THE WAKE OF THE FRONT.
OUTLOOK...
MON..VFR...SLIGHT CHC -SHSNS KALB-KGFL.
MON NIGHT...VFR/MVFR WITH -SN LIKELY.
TUE...VFR/MVFR AT KGFL WITH -SN LIKELY ESP IN THE MORNING. KALB
SOUTH TO KPOU VFR.
TUE NIGHT-WED...VFR/MVFR. CHC -SHRA/-SHSN.
THU...VFR...SLIGHT CHC -SHRA AT KPOU.
FRI...VFR...SLIGHT CHC -SHRA/-SNSHS.
&&
.HYDROLOGY...
RIVER FLOWS CONTINUE TO RECEDE. A CLIPPER LOW PRESSURE SYSTEM AND
TWO COLD FRONTS WILL IMPACT THE REGION THIS EVENING INTO MONDAY
MORNING. SOME SCATTERED SNOW SHOWERS AND FLURRIES WILL BE COMMON
WITH LIGHT SNOW ACCUMULATIONS UP TO A FEW INCHES IN THE SOUTHERN
ADIRONDACKS. A WARM FRONT WILL ALSO BRING SOME LIGHT SNOW MONDAY
NIGHT INTO TUESDAY MORNING.
OVERALL...RIVER FLOWS WILL CONTINUE TO RECEDE INTO THE MID WEEK
ADN ANY RAINFALL THAT OCCURS WILL BE LIGHT AND MOST PRECIPITATION
DURING THE WEEK WILL BE LIGHT SNOW.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WINTER WEATHER ADVISORY UNTIL 10 AM EST MONDAY FOR NYZ032-033-
038.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SNYDER/WASULA
NEAR TERM...11/NAS/WASULA
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...WASULA
HYDROLOGY...NAS/WASULA
AREA FORECAST DISCUSSION
NWS NEW YORK NY
117 PM EST SUN JAN 29 2012
.SYNOPSIS...
HIGH PRESSURE WILL BE SITUATED OVER THE TRI STATE AREA TODAY. A
COLD FRONT PASSES THROUGH TONIGHT. HIGH PRESSURE RETURNS ON
MONDAY. A WARM FRONT APPROACHES MONDAY NIGHT AND LIFTS NORTH OF US
TUESDAY MORNING. A COLD FRONT FOLLOWS WEDNESDAY INTO WEDNESDAY
NIGHT. ADDITIONAL STORM SYSTEMS MAY AFFECT THE REGION LATE IN THE
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LITTLE CHANGE TO TEMPS/DEWPOINTS AS THEY SEEM TO BE ON TRACK THIS
AFTERNOON. WINDS ADJUSTED SLIGHTLY DOWNWARD TO ACCOUNT FOR CURRENT
TRENDS.
HIGH PRESSURE FROM THE SOUTH AND WEST BUILDS IN TODAY AND OFFSHORE
GOING INTO THIS EVENING. WEST TO SOUTHWEST WINDS WITH GOOD
VERTICAL MIXING UP TO ABOUT 800 MB STILL EXPECTED. ACARS SOUNDINGS
INDICATE MIXING UP TO 900 MB SO FAR AND GFS AND RUC BUFKIT
SOUNDINGS INDICATE A JUMP IN VERTICAL MIXING TO AROUND 800 MB AT
LEAST FOR THIS AFTERNOON BETWEEN 3 AND 5 PM. ADIABATICALLY MIXING
DOWN TO SURFACE TEMPS WITH SOME LOWERING FACTORS CONSIDERING MID
AND HIGH LEVEL CLOUDS COMING IN FROM THE WEST...YIELDS A END
RESULT RANGING OF HIGHS FROM LOWER 40S ACROSS INTERIOR ELEVATED
LOCATIONS TO THE MID AND UPPER 40S ELSEWHERE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
LONGWAVE TROUGH AXIS APPROACHES US TONIGHT WITH A VIGOROUS
SHORTWAVE MOVING ALONG ITS BASE. THIS SHORTWAVE IS PROGGED TO
PASS RIGHT OVER THE CWA TONIGHT. AN ACCOMPANYING COLD FRONT WILL
ALSO BE MOVING THROUGH THE REGION. HAVE GONE ABOVE GUIDANCE POPS
AND WENT WITH A 30 PERCENT CHANCE OF PRECIP. WITH SUCH A VIGOROUS
SHORTWAVE MOVING THROUGH...INSTABILITY ALOFT WILL INCREASE WITH
THE STRONG COLD ADVECTION. MODELS SHOWING LAPSE RATES OF AROUND
8-9 C/KM IN THE 850-500MB LAYER PASSING THROUGH TONIGHT. ALTHOUGH
MODELS DO NOT NECESSARILY SHOW DEEP MOISTURE DURING THE TIME THAT
THIS SYSTEM MOVES THROUGH...THINKING IS THAT THIS INSTABILITY AND
LIFT WILL BE ABLE TO MAKE EFFICIENT USE OF THE AVAILABLE MOISTURE.
00Z SPC WRF AND NAM FORECAST 1KM REFLECTIVITY EVEN DEPICT A
BROKEN SQUALL LINE MOVING THROUGH THE REGION TONIGHT...PICKING UP
MOISTURE APPARENTLY FROM THE COASTAL WATERS AS IT PASSES THROUGH.
THERMAL PROFILES SUPPORT SNOW SHOWERS NORTH OF THE CITY...AND A
RAIN/SNOW SHOWER MIX FOR THE CITY/ADJACENT SUBURBS AND LONG
ISLAND. WHERE IT DOES REMAIN ALL SNOW...A LIGHT COATING OF SNOW
WILL BE POSSIBLE. 30-35 MPH GUSTS WILL BE POSSIBLE TO BEHIND THE
COLD FRONT WITH THE STRONG COLD ADVECTION.
HIGH PRESSURE AND DRY WEATHER FOR MONDAY. MAV/NAM MOS BLEND LOOKED
GOOD AGAIN FOR TEMPS. A WARM FRONT THEN APPROACHES MONDAY
NIGHT...AND WITH THE NAM TYPICALLY BETTER AT HOLDING IN COLD AIR
DUE TO DAMMING...WILL GO WITH ITS IDEA THAT THE FRONT DOES NOT
MOVE NORTH OF US UNTIL TUESDAY MORNING. ISENTROPIC LIFT AHEAD OF
THE FRONT MAY PRODUCE SOME LIGHT SNOWFALL FOR PART OF THE CWA.
KEPT IN SLIGHT CHANCE POPS MONDAY NIGHT...BUT DRY OVER THE SW
CORNER OF THE CWA AS PER MODEL AGREEMENT. A NON DIURNAL
TEMPERATURE TREND WAS USED...CONSIDERING CLOUDS THICKENING THROUGH
THE NIGHT.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
A MILD AND DRY DAY ANTICIPATED ON TUESDAY WITH A WARM FRONT LIFTING
TO THE NORTH. HIGHS REACHING THE MID 50S ACROSS THE WARMEST
SPOTS. A COLD FRONT THEN APPROACHES FROM THE WEST...BRINGING A
CHANCE OF RAIN SHOWERS LATE TUESDAY NIGHT. MODELS AGREE THAT THE
FRONT MOVES THROUGH LATE WEDNESDAY INTO WEDNESDAY NIGHT WITH A
CONTINUED THREAT OF SHOWERS.
MODELS CONTINUE TO DIVERGE REGARDING THE FORECAST FROM THURSDAY ON.
AFTER COLLABORATION WITH THE SURROUNDING OFFICES...HAVE MOSTLY LEFT
THIS PORTION OF THE FORECAST ALONE. GENERALLY LEANING TOWARDS THE
IDEA DEPICTED BY HPC...WHERE WEAK LOW PRESSURE APPROACHES FROM THE
WEST ON THURSDAY...THEN PASSES NEARBY THURSDAY NIGHT INTO FRIDAY.
LONGWAVE TROUGHING OVER THE REGION WOULD THEN FOLLOW ON
SATURDAY...WITH A COLD FRONT OR LOW PRESSURE SYSTEM POTENTIALLY
AFFECTING THE AREA.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
RIDGE OF HIGH PRESSURE TO THE EAST WEAKENS AS A COLD FRONT
APPROACHES THROUGH EARLY THIS EVENING. THE FRONT CROSSES THE
TERMINALS FROM ABOUT 05Z THROUGH 10Z. HIGH PRESSURE BUILDS BEHIND
THE FRONT MONDAY.
VFR THROUGH THE TAF PERIOD. MAINLY DRY...HOWEVER THERE IS A CHANCE
OF SCATTERED SNOW SHOWERS WITH THE FRONT. BEST CHANCE WILL BE AT
KSWF WHERE LOW END VFR TO HIGH END MVFR CONDITIONS WILL BE POSSIBLE
FROM 05Z TO 08Z.
GUSTY WESTERLY WINDS GRADUALLY BECOME MORE SOUTHWEST BY LATE
AFTERNOON. WITH THE PASSAGE OF THE FRONT WINDS SHIFT BACK TO WEST
AND GUSTS INCREASE FOR A TIME...NEARING 30 KTS.
OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...
MONDAY THROUGH TUESDAY...VFR. GUSTY WESTERLY WINDS MONDAY.
WEDNESDAY...SUB-VFR POSSIBLE IN RAIN.
THURSDAY...VFR.
FRIDAY...LOW CHANCE OF SUB VFR.
&&
.MARINE...
LAST UPDATE...WITH LOWERING TREND TO WINDS AND SEAS BELOW
SCA...DROPPED SCA FOR WESTERN WATERS...BUT KEPT IT FOR EASTERN LI
SOUND AND BAYS AS WELL AS OCEAN WATERS SOUTH OF LONG ISLAND EAST
OF FIRE ISLAND INLET FOR REMAINDER OF AFTERNOON.
IN THE WAKE OF A COLD FRONT CROSSING THE WATERS THIS
EVENING...WINDS VEER TO THE W...WITH GUSTS LIKELY REACHING GALE
FORCE OVERNIGHT. AS A RESULT HAVE ISSUED A GALE WATCH FOR ALL
WATERS TONIGHT.
WIND GUSTS SHOULD DIMINISH TO SCA LEVELS BY MONDAY
MORNING...EXCEPT ON THE COASTAL OCEAN ZONES...WHERE GALES SHOULD
COULD LINGER THROUGH THE MORNING. SCA GUSTS COULD QUITE POSSIBLY
CONTINUE THROUGH THE DAY ON ALL WATERS MONDAY.
MONDAY NIGHT SHOULD SEE ALL BUT THE TWO EASTERN COASTAL OCEAN
ZONES HAVE CONDITIONS FALL BELOW SCA LEVELS. STILL COULD SEE SCA
GUSTS AT LEAST INTO THE EVENING IN THE EASTERN COASTAL
WATERS...WITH FAR EASTERN WATERS POSSIBLY MAINTAINING SCA LEVEL
GUSTS AND SEAS THROUGH THE NIGHT.
THE BATTLE IS THEN ON BETWEEN STRONG WINDS 950-850 HPA AND A LOW
LEVEL INVERSION TUESDAY-WEDNESDAY FOR NOW KEEP GUSTS TO AT MOST
SCA LEVELS...BUT POTENTIAL FOR GALES CANNOT BE COMPLETELY RULED
OUT IN THIS TIME FRAME.
HIGH PRESSURE BUILDS IN WEDNESDAY NIGHT-THURSDAY...SO SUB-SCA
CONDITIONS FORECAST.
&&
.HYDROLOGY...
ANY LIQUID EQUIVALENT PRECIPITATION THROUGH WEDNESDAY IS EXPECTED
TO BE ON THE LIGHT SIDE.
&&
.EQUIPMENT...
THE WEATHER OBSERVATION FROM CENTRAL PARK WILL BE UNAVAILABLE
UNTIL FURTHER NOTICE. THIS IS DUE TO A SIGNIFICANT POWER
INTERRUPTION TO THE CENTRAL PARK AUTOMATED SURFACE OBSERVING
STATION /ASOS/ AND BACKUP STATION. UTILITY WORKERS ARE ADDRESSING
THE PROBLEM...BUT THERE IS CURRENTLY NO ESTIMATED TIME FOR RETURN
TO SERVICE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...GALE WATCH FROM 6 PM EST THIS EVENING THROUGH LATE TONIGHT FOR
ANZ330-335-338-340-345-350-353-355.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ330-
340-350-353.
&&
$$
SYNOPSIS...
NEAR TERM...JM
SHORT TERM...
LONG TERM...
AVIATION...MET
MARINE...JM/MALOIT
HYDROLOGY...
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS ALBANY NY
104 PM EST SUN JAN 29 2012
.SYNOPSIS...
THE PARADE OF FAST MOVING WEATHER SYSTEMS WILL CONTINUE
ACROSS THE NORTHEAST. HIGH PRESSURE RIDGED ALONG THE MID ATLANTIC
COAST WILL MOVE OFFSHORE THIS AFTERNOON...AS TWO COLD FRONTS WILL
MOVE ACROSS THE REGION THIS EVENING AND OVERNIGHT. ON MONDAY...HIGH
PRESSURE WILL BRIEFLY MOVE OVER THE NORTHEAST...THEN IT WILL SHIFT
OFFSHORE MONDAY NIGHT...AND A WARM FRONT WILL SET UP FROM THE UPPER
GREAT LAKES TO CAPE COD BY TUESDAY...PRODUCING SOME LIGHT SNOW FOR
THE REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 AM EST...WE CANCELED THE LAKE EFFECT SNOW ADVISORY FOR
NRN HERKIMER CTY...AS THE BAND AS SHIFTED NORTH OF THE AREA IN THE
BACKING LOW-LEVEL FLOW TO THE SW. THE BAND IS NOW IN THE ST
LAWRENCE RIVER VALLEY. SNOW TOTALS FROM THE LAKE EFFECT AND SNOW
SQUALLS THE PAST 12 TO 15 HOURS HAVE RANGED FROM 3 TO 7 INCHES
WITH SOME ISOLATED HIGHER AMOUNTS POSSIBLE. PLEASE SEE OUR LATEST
PNS STATEMENT.
THE TREND WILL BE FOR A BRIEF BREAK IN THE LATE MORNING INTO THE
EARLY PM FOR MOST OF THE REGION WITH THE RIDGING FROM THE SOUTH.
HOWEVER...ANOTHER POTENT SHORT-WAVE TROUGH IS APPROACHING FROM NRN
IL THIS MORNING. THIS STRONG UPPER LEVEL DISTURBANCE AND ITS
ASSOCIATED COLD FRONT WILL INCREASE THE CHANCE OF SNOW SHOWERS AND
ISOLD SQUALLS FROM WEST TO EAST LATE THIS AFTERNOON INTO THE
OVERNIGHT PERIOD. ONCE AGAIN...BASED ON THE 3-KM REF PRODUCT FROM
THE HRRR AND THE HIRES WRF FAVORS 00Z-03Z. THE HRRR IS FASTER WITH
A 22Z-01Z TIMING WITH THE FIRST BOUNDARY. A SECOND STRONGER
BOUNDARY WITH THE UPPER TROUGH...THE HRRR HAS APPROACHING
BTWN 03Z-06Z FOR THE FCST AREA. WE TRENDED THE SKY COVER TO PARTLY
TO MOSTLY SUNNY FROM THE HUDSON RIVER VALLEY EASTWARD INTO THE
EARLY TO MID PM...BEFORE THE CLOUD INCREASE AHEAD OF THE FIRST
FRONT. MAX TEMPS WILL STILL RUN ABOVE NORMAL WITH U30S TO L40S IN
THE VALLEYS...AND U20S TO M30S OVER THE MTNS. T/TD/RH/APPARENT
TEMP TRENDS WE REDONE BASED ON OBSERVATIONS. THE HIGHEST SNOW
ACCUMULATIONS WITH THIS DISTURBANCE LOOK LIKE THEY WILL BE NORTH
AND WEST OF OF THE CAPITAL REGION WITH 1 TO 4 INCHES POSSIBLE
/ESPECIALLY THE WRN DACKS AND WRN MOHAWK VALLEY/.
PREVIOUS NEAR TERM...
LAKE EFFECT BAND STILL PERSISTENT...AND SHOULD CONTINUE UNTIL WARM
ADVECTION BEGINS LATER THIS MORNING...WHEN THE BAND SHOULD BECOME
DISRUPTED. ALSO SOME ISOLATED SNOW SHOWERS AND FLURRIES STILL INTO
THE SCHOHARIE VALLEY. KEEPING THE SNOW IN THE FORECAST FOR THE
NEXT COUPLE OF HOURS IN THE SCHOHARIE VALLEY AND WESTERN MOHAWK
VALLEY...WHILE KEEPING THE NORTHERN HERKIMER AREA IN BETTER
CHANCES THROUGH THE MORNING. ONE REPORT OF JUST OVER A FOOT
WAS JUST RECEIVED...BUT KEEPING ADVISORY UP AS MOST AREAS SHOULD
SEE 7 INCHES OR LESS.
CLOUD COVER HIGHLY DEPENDENT ON LAKE EFFECT MOISTURE THIS MORNING
BUT THERE SHOULD BE LESS CLOUD COVER ONCE THE LAKE EFFECT BAND IS
DISRUPTED THIS AFTERNOON. SO...JUST SOME MINOR ADJUSTMENTS TO SKY
COVER AND TEMPERATURES THROUGH THIS MORNING.
PREV AFD BELOW...
LAKE EFFECT BAND STILL EXTENDING INTO THE WESTERN MOHAWK VALLEY AND
SOUTHERN ADIRONDACKS. IT IS A BIT CELLULAR AS THE DEPTH OF THE
MOISTURE AND INSTABILITY IS RELATIVELY DEEP...EVIDENT IN THE 00Z BUF
SOUNDING. THE BAND SHOULD CONTINUE TO BRING SNOW INTO THE AREA
THROUGH THE EXPIRATION OF THE WINTER WEATHER ADVISORY. SOME ISOLATED
REFLECTIVITIES ARE RESPECTABLE BUT BASED ON THERMAL PROFILES AND THE
RAPIDLY CHANGING CHARACTER OF THE BAND...SNOW RATIOS AND DURATION OF
HEAVIEST SNOW SEEMS TO SUGGEST SNOW SHOULD STAY WITHIN THE ADVISORY
RANGE. SNOWFALL AMOUNTS STILL LOOK TO BE UP TO 7 INCHES. SOME
ISOLATED SNOW SHOWER ACTIVITY ALSO EXTENDING INTO THE SCHOHARIE
VALLEY THROUGH THE EARLY MORNING HOURS BUT LIGHTER AND MORE
SCATTERED THAN THE SINGLE BAND TO THE NORTH.
WARM ADVECTION WILL BEGIN BY LATE MORNING...SO THE SINGLE BAND AND
THE SCATTERED ACTIVITY TO THE SOUTH IN THE SCHOHARIE VALLEY SHOULD
GET DISRUPTED AROUND OR SHORTLY AFTER SUNRISE. THERE SHOULD BE SOME
PERIODS OF SUN THROUGH AT LEAST THE MORNING...MAYBE INTO THE
AFTERNOON...ESPECIALLY IN EASTERN AREAS...DEPENDING ON HOW QUICKLY
THE NEXT SYSTEM APPROACHES FROM THE GREAT LAKES. BASED ON MIXING
POTENTIAL TODAY...HIGHS IN THE UPPER 30S TO MID 40S BEFORE CLOUD
COVER ARRIVES. HIGHS IN THE LOWER TO MID 30S IN THE SOUTHERN
ADIRONDACKS AND SOUTHERN GREEN MOUNTAINS.
NEXT QUICK MOVING NORTHERN STREAM SYSTEM TRACKS THROUGH THE REGION
TONIGHT...WHICH LOOKS TO BE RELATIVELY MOISTURE STARVED...EXCEPT FOR
WHAT COULD BE PICKED UP OFF THE GREAT LAKES. STILL...MOSTLY CLOUDY
MUCH OF THE NIGHT...WITH THE MOST WIDESPREAD SNOW SHOWER ACTIVITY IN
THE WESTERN MOHAWK VALLEY AND SOUTHERN ADIRONDACKS. SCATTERED
ACTIVITY SHOULD MAKE IT INTO MOST OF THE REGION...WITH MORE ISOLATED
ACTIVITY IN THE MID HUDSON VALLEY..SOUTHERN BERKSHIRES AND NW CT.
THERE COULD BE 1 TO 3 INCHES OF SNOW IN THE NORTHERN AREAS WITH
LOCAL DUSTINGS POSSIBLE ACROSS THE REST OF THE REGION. SOME PARTIAL
CLEARING IS POSSIBLE TOWARD SUNRISE...BUT GUSTY WEST TO NORTHWEST
WINDS SHOULD BEGIN AS THE SYSTEM EXITS LATE TONIGHT. LOWS IN THE
20S...BUT A LITTLE HIGHER THAN GUIDANCE NUMBERS DUE TO THE WINDS AND
MIXING. SOME LOWS IN THE TEENS IN THE SOUTHERN ADIRONDACKS.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
BACK DOOR CDFNT PUSHES SOUTH INTO FCA AS 500HPA SHORT WVS MOVE
EAST ACROSS NEW YORK NEW ENG. THIS WILL BRING A BRIEF PERIOD OF
COLD AIR AND REINVIGORATE LK EFFECT BAND INTO TUG HILL/W ADNDKS.
BY MON NT. LATE MONDAY INTO TUES EASTERN TROF DEPARTS...RIDGING
BUILDS FROM GRTLKS TO SE STATES AND A 500HPA SHORT WAVE EJECTS INTO
NORTHERN GREAT PLAINS. THIS SETS UP FRONTOGENESIS AS WMFNT ORGANIZES
DLH-BOS. MONDAY AND MONDAY NIGHTS CLOUDS BLOOM ALL ALONG AND AHEAD OF
IT...AND OVERRUNNING SNOW BREAKS OUT ACROSS THE GRTLKS.
MON NT INTO TUE MORNING THIS -SN SPREADS ACROSS NY/NEW ENG. THE
NAM/GFS/ECMWF ARE SIMILAR BUT NAM QPF IS DEFINITELY LIGHTER. THE
GEM HAS BULK OF PCPN N OF FCA. AS THE 500HPA FLOW TURNS SW THE
MODEL SUIT GENERALLY LIFTS TO WMFNT OUT OF THE FCA TUE
EVNG...LEAVING AREA IN WARM SECTOR WITH -SHRA THREAT TILL CDFNT
MOVES THROUGH WED. THEY ALL TAKE MAJOR CYCLONE WITH THIS SYSTEM
WELL NORTH INTO ONT/QB.
TEMPS ARE GENERALLY ABV NORMAL TO MUCH ABV DURING THIS PERIOD.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
THE FAST MOVING PATTERN CONTINUES WITH A SHORT WV MOVING THROUGH
THUR TRIGGERING ISOLD TO SCT -SHSN...MORE NEAR THE LAKE. HIGH
PRESSURE RIDGES SOUTH TO END THE WEEK WITH DRY CONDS...THEN THE
MODELS TAKE THE BIG DIVERGE. THE GFS PRODUCES A SIGNIFICANT
COASTAL LOW...AS USUAL BASED ON THE PHASING OF SHORT WAVES THAT
ARE SCATTERED ALL OVER EAST ASIA. THE ECMWF TAKES THIS STORM...NOT
UP THE EAST COAST...BUT UP THE ST LAWRENCE VLY. THE MODEL SUITE
HAS BEEN ALL OVER WITH THIS SYSTEM FROM IN THE WEST ATLC. FOR NOW
CARRIED CHC OR SLIGHT CHC. THERE`S 6 DAYS TO THE MODELS TO DEBATE
WITH THEMSELVES HOW THE SHORT WVS WILL PHASE. TEMPS DURING THE EFO
WILL BEGIN ABV NORMALS THU AND END THE PERIOD NEAR NORMAL.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
HIGH PRESSURE IS BRIEFLY RIDGING IN FROM THE SOUTH THIS
AFTERNOON...BUT A STRONG UPPER LEVEL DISTURBANCE ASSOCIATED WITH A
CLIPPER LOW IS APPROACHING FROM THE LOWER GREAT REGION. THE CLIPPER
...AND ITS COLD FRONT WILL QUICKLY MOVE ACROSS ERN NY AND WRN NEW
ENGLAND TONIGHT. HIGH PRESSURE WILL BRIEFLY BUILD IN FROM SOUTHERN
QUEBEC FOR MONDAY.
VFR CONDITIONS ARE EXPECTED TO LAST INTO THE EARLY EVENING WITH
THICKENING CIRRUS AND A HIGH STRATUS DECK AT 5-6 KFT AGL AHEAD OF
THE CLIPPER. THE BEST CHANCE OF SNOW SHOWERS OR ISOLD SNOW SQUALLS
IMPACTING ANY TERMINALS WILL BE NORTH OF KALB TOWARD KGFL. WE
INCLUDED A PERIOD OF AT LEAST MVFR CONDITIONS THERE BTWN 05Z-09Z. WE
USED VCSH GROUPS STARTING AT 02Z THERE. FURTHER SOUTH WE KEPT A
VCSH GROUP AT KALB. TEMPOS MAY BE ADDED LATER TO ACCOUNT FOR A
BRIEF PERIOD OF MVFR/IFR CONDITIONS WITH ANY SNOW SHOWERS OR
SQUALLS. KPOU LOOKS TO BE FURTHER SOUTH AWAY FROM THE BETTER
CONVERGENCE WITH THE CLIPPER AND COLD FRONT...WHERE IT IS UNCERTAIN
OF ANY REDUCTION BELOW VFR LEVELS OR A VCSH IS NEEDED AT THIS TIME.
THE SNOW SHOWERS...FLURRIES AND ISOLD SQUALLS SHOULD BE EAST OF THE
HUDSON RIVER VALLEY AT 09Z. THE WINDS WILL INCREASE FROM THE W/NW
WITH VFR CONDITIONS AND SCT-BKN CIGS 4-5 KFT AGL.
THE WINDS WILL BE FROM THE W/SW THIS AFTERNOON AT 8-13 KTS WITH A
FEW GUSTS 20-25 KTS...AND THEN BACK TO THE S/SW AT AROUND 10 KTS
AHEAD OF THE CLIPPER. EXPECT THE WINDS TO SHIFT TO THE W/NW AT 8-15
KTS WITH THE COLD FRONTAL PASSAGE SHORTLY AFTER MIDNIGHT...AND
PERSIST INTO THE LATE MORNING. SOME GUSTS TO AROUND 25 KTS WILL BE
POSSIBLE AT KALB THROUGH THE MORNING IN THE WAKE OF THE FRONT.
OUTLOOK...
MON..VFR...SLIGHT CHC -SHSNS KALB-KGFL.
MON NIGHT...VFR/MVFR WITH -SN LIKELY.
TUE...VFR/MVFR AT KGFL WITH -SN LIKELY ESP IN THE MORNING. KALB
SOUTH TO KPOU VFR.
TUE NIGHT-WED...VFR/MVFR. CHC -SHRA/-SHSN.
THU...VFR...SLIGHT CHC -SHRA AT KPOU.
FRI...VFR...SLIGHT CHC -SHRA/-SNSHS.
&&
.HYDROLOGY...
RIVER FLOWS CONTINUE TO RECEDE. A CLIPPER LOW PRESSURE SYSTEM AND
TWO COLD FRONTS WILL IMPACT THE REGION THIS EVENING INTO MONDAY
MORNING. SOME SCATTERED SNOW SHOWERS AND FLURRIES WILL BE COMMON
WITH LIGHT SNOW ACCUMULATIONS UP TO A FEW INCHES IN THE SOUTHERN
ADIRONDACKS. A WARM FRONT WILL ALSO BRING SOME LIGHT SNOW MONDAY
NIGHT INTO TUESDAY MORNING.
OVERALL...RIVER FLOWS WILL CONTINUE TO RECEDE INTO THE MID WEEK
ADN ANY RAINFALL THAT OCCURS WILL BE LIGHT AND MOST PRECIPITATION
DURING THE WEEK WILL BE LIGHT SNOW.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WINTER WEATHER ADVISORY UNTIL 10 AM EST MONDAY FOR NYZ032-033-
038.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SNYDER/WASULA
NEAR TERM...NAS/WASULA
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...WASULA
HYDROLOGY...NAS/WASULA
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1207 PM EST SUN JAN 29 2012
...Updated Aviation Discussion...
...Forecast Update...
Winds have begun to become gusty over the last hour with a couple of
sites gusting to around 30 mph already. For now will keep the wind
advisory in place where it is and watch observations to see if it
needs to be expanded later. Made some minor tweaks to the grids to
update them based on current conditions. Also removed the pops from
the far northern part of the forecast area this afternoon. While a
few flurries or sprinkles are not out of the question, the main area
of precipitation should remain to our north. Other than that, no
major changes. Updates will be out soon.
&&
.Short Term (Today and Tonight)...
...A Windy Day Ahead...
The main challenges in the short term period are gusty winds today
and the slight chance for precip over southeast Indiana and the
northern Bluegrass. These challenges are courtesy of an upper level
wave crossing the Great Lakes and associated sfc front passing
through our area this afternoon.
First of all, light precip may fall over southeast Indiana and the
northern Bluegrass from 18Z-0Z. The latest RR model has the best
handle on this precip which was over southern MN, central Iowa, and
western WI as of 730Z. This clipper will push a thin band of low
level moisture into the Ohio Valley this afternoon. Model soundings
indicate temps will be cold enough aloft for ice crystal
production. However, sfc temps will be in the upper 30s and low 40s
by the afternoon hours, so precip should reach the sfc as just plain
rain with maybe some ice pellets mixing in. Precip will exit the
area by 0Z.
As for winds, a 35-40 kt LLJ will push through our area just ahead
of the front today. This will create the potential for wind gusts
in the 30-40 mph range over southern Indiana and central KY. Will
go ahead and issue an SPS for most of this area. Over the Bluegrass
region, however, it looks like the LLJ will cross during peak mixing
which may cause peak wind gusts in the 40 to 45 mph range. GFS,
SREF, and NAM soundings all indicate gusts into this range,
therefore, felt confident enough to issue a wind advisory along and
east of a line from Scott County to Casey County in KY. This
matches well with ILN wind advy and JKL lake wind advy. The
Bluegrass advy will be valid from 16Z-23Z.
As for temps, we should see a gradient of highs from north to south
today with the colder, cloudier southern Indiana/northern KY area
only reaching the lower 40s for highs while the warmer, sunnier
south central KY area reaches the upper 40s. Low temps tonight
should cool into the mid 20s to around 30.
.Long Term (Monday through Saturday)...
We`ll sit under a fairly flat flow early in the long term, until a
weak wave moves into the Great Lakes Tuesday night...then a slightly
stronger one enters the Ohio Valley Wednesday night, and then a much
deeper upper trof dives into much of the eastern United States
Friday-Saturday. This should translate into tranquil weather early
in the long term and then increasingly unsettled conditions (not to
mention model disagreement) in later periods.
Will lean, with great trepidation, towards a blend of the
operational GFS/GFS ensemble mean/GEM ensemble mean, which are in
decent (albeit tenuous) agreement with each other. The operational
ECMWF goes off on its own by late in the week and is not in good
agreement with its own ensemble mean (which has some similarities to
the above mentioned suite of models). Unfortunately since there is
so much disagreement among the models it`s difficult to put much
faith in any solution.
Forging ahead anyway, at this time we will go with high pressure
over the southeast U.S. Monday-Tuesday. A tight gradient on the
backside of the high will pump warm air northward on stiff SSW
breezes. As a result, we went with rather warm temperatures for the
first couple of days of the new work week, including at night since
it appears the breezes will keep up around 10mph even after sunset.
Tuesday night should be especially warm ahead of an approaching cold
front. We should see gusts to at least 25 mph Monday afternoon and
30 mph Tuesday afternoon.
That cold front will approach from the northwest Tuesday night and
push through the LMK CWA on Wednesday, weakening as it does so.
Showers look likely with this feature Tuesday night-Wednesday,
tapering off Wednesday evening. No thunder is expected.
Thursday through Saturday are a mess in the model data. Inkling
right now is that Thursday may be dry as we sit between systems,
but given the Euro`s strong precipitation signal and in attempting
to blend with surrounding offices, will need to hang on to a small
POP.
Thursday night into Saturday a deep upper trof will dig into the
eastern U.S. and will bring chances of light, spotty precipitation
Thursday night into the weekend. Most of the precip should be in
the form of rain, though some snow could mix in late Friday night
into Saturday morning.
&&
.Aviation (18Z TAF Issuance)...
The forecast for this TAF period is mainly a wind forecast. Winds
have become gusty late this morning ahead of a cold front moving
through this afternoon. Winds will remain out of the southwest until
the front passes through the TAF sites, then shift to the west
behind the front. Peak gusts this afternoon will be in the 25-30
knot range at SDF and BWG and in the 30-35 knot range at LEX. For
tonight winds will become light and variable as high pressure slides
across the region. Winds will quickly shift back to the southwest
tomorrow morning with gusty winds once again expected through the
late morning and afternoon. Ceilings will be VFR through the TAF
period.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...WIND ADVISORY UNTIL 6 PM EST THIS EVENING FOR
KYZ036-037-040>043-
047>049-055>057-066-067.
$$
Update...........EER
Short Term.......AMS
Long Term........13
Aviation.........EER
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
600 PM EST SUN JAN 29 2012
.SYNOPSIS...
A FAST MOVING COLD FRONT CAN BRING STRONG WIND GUSTS AND A MIX OF
LIGHT RAIN SLEET AND SNOW SHOWERS THIS EVENING. HIGH PRESSURE PASSING
TO THE SOUTH WILL THEN PROVIDE DRY SEASONABLE CONDITIONS MONDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
QUICK EARLY EVE UPDATE ISSUED BASED ON CURRENT TRENDS OF +SNOW
SHOWERS AND ACCUMULATION TO AROUND AN INCH.
HAVE CONTINUED THE WIND ADVISORY FOR GUSTS OVER 45 MPH THIS
EVENING WITH THE PASSAGE OF THE COLD FRONT. TIMING AND WIND GUSTS
BASED ON RADAR AND OBS. TRENDS. WIND WILL DIMINISH IN THE WAKE OF
THE FRONT.
BASED ON RECENT NAM AND HRRR MODEL VALUES, FORECASTED LOW
TEMPERATURES TO BE NEAR NORMAL,
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
ON MONDAY, SREF MODEL OUTPUT SHOWS THE UPPER JETSTREAM FLOW BACKING
SLIGHTLY INTO THE WEST SOUTHWEST. HENCE THE NEXT SHORT WAVE WILL
TO PASS EASTWARD THROUGH THE GREAT LAKES SHOULD HAVE LESS IMPACT
ON THE UPPER OHIO VALLEY. STILL INCLUDED A CHANCE OF SHOWERS OF
SNOW, BUT MAINLY NORTH. REST OF THE UPPER OHIO VALLEY WILL STAY
DRY THROUGH DAYTIME TUESDAY.
SREF MODEL OUTPUT THEN SHOWS THE NORTHERN JETSTREAM BRANCH GAINING
MORE INFLUENCE. THIS WILL STEER A LOW PRESSURE SYSTEM TO MOVE
SOUTHEAST FROM THE CANADIAN ROCKIES TO PUSH A COLD FRONT WITH RAIN
SHOWERS THROUGH THE UPPER OHIO VALLEY DAYTIME WEDNESDAY.
FORECAST TEMPERATURES THIS PERIOD USING BLEND OF GFS AND NAM MOS.
THIS GUIDANCE SHOWED HIGHS MONDAY TO BE 2-3 DEGREES WARMER THAN
NORMAL, AND LOWS AND HIGHS TUESDAY AND WEDNESDAY TO BE NEARLY 15
DEGREES WARMER THAN NORMAL.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS WAS THE CASE YESTERDAY...MODELS CONTINUE TO HAVE TROUBLE
RESOLVING THE PLACEMENT AND TIMING OF SYSTEMS DURING THIS PERIOD.
WHILE ALL THE MODELS CONTINUE TO SUGGEST A DEEPENING LONG WAVE
PATTERN...WITH A STRONG RIDGE OVER THE WESTERN U.S AND A DEEP TROUGH
OVER THE EASTERN U.S...THE SHORTWAVE PATTERN AND IN TURN LOW
PLACEMENT REMAINS INCONSISTENT FROM RUN TO RUN.
IN GENERAL...MODELS SUGGEST THAT THE COLD FRONT...PROGGED TO CROSS
THE OHIO VALLEY DURING THE DAY WEDNESDAY...WILL HANG UP AROUND THE
MASON-DIXON LINE AND EVENTUALLY MOVE NORTHWARD AS A WARM FRONT. THE
QUESTION IS WHEN AND HOW FAR NORTH WILL THE SYSTEM MAKE IT AT THIS
POINT.
CONTINUED TO REMAIN CLOSE TO HPC GUIDANCE WITH ONLY LOW CHANCE POPS
THROUGH MOST OF THE PERIOD WITH SUCH MODEL UNCERTAINTY AND
TEMPERATURES CLOSE TO AN HPC MEX BLEND.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL CONTINUE FOR A FEW MORE HOURS BEFORE ANOTHER
FAST MOVING COLD FRONT IMPACTS THE TERMINALS LATER THIS AFTERNOON.
MAINTAINED MOSTLY MVFR CIGS/VSBY AT ALL SITES WITH THE SYSTEM...BUT
IFR VSBY WILL BE POSSIBLE IN SNOW SHOWERS ESPECIALLY AT KFKL AND
KDUJ. WILL GRADUALLY IMPROVE SITES BACK TO VFR OVERNIGHT PER SREF
AND LAMP GUIDANCE HOWEVER...STRATOCUMULUS MAY REMAIN UNTIL MONDAY
MORNING AS W-NW WINDS ALLOWING FOR SOME LAKE INDUCED CLOUDS.
OUT AHEAD OF AND JUST BEHIND THE SYSTEM WINDS WILL VEER FROM S-SW TO
MORE W-NW AND INCREASE TO NEAR 15-20KTS SUSTAINED WITH GUSTS TO
35KTS POSSIBLE.
OUTLOOK...MONDAY THROUGH FRIDAY...
ANOTHER CLIPPER TYPE SYSTEM MAY CAUSE SOME RESTRICTIONS TO THE
NORTHERN TAF SITES MONDAY AFTERNOON BUT MOISTURE IS RATHER LIMITED.
ELSEWHERE...VFR IS EXPECTED THROUGH WEDNESDAY. A COLD FRONT WILL
THEN BRING A GREATER CHANCE FOR RESTRICTIONS AT ALL SITES WEDNESDAY
AND THURSDAY. RESTRICTIONS MAY BE POSSIBLE FRIDAY BUT THERE IS MUCH
UNCERTAINTY IN THE FORECAST AT THIS POINT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR MDZ001.
OH...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR OHZ039>041-
048>050-057>059-068-069.
PA...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR PAZ007>009-
013>016-020>023-029-031-073>076.
WV...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR WVZ001>004-012-
021>023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
340 PM EST SUN JAN 29 2012
.SYNOPSIS...
A FAST MOVING COLD FRONT CAN BRING STRONG WIND GUSTS AND A MIX OF
LIGHT RAIN SLEET AND SNOW SHOWERS THIS EVENING. HIGH PRESSURE PASSING
TO THE SOUTH WILL THEN PROVIDE DRY SEASONABLE CONDITIONS MONDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
HAVE EXPANDED WIND ADVISORY FOR GUSTS OVER 45 MPH THIS EVENING
WITH THE PASSAGE OF A COLD FRONTAL BAND OF SHOWERS OF RAIN AND
SNOW AND POSSIBLY SLEET. TIMING AND WIND GUSTS BASED ON HRRR MODEL
OUTPUT. WINDS WILL DIE DOWN OVERNIGHT.
TO BE TECHNICAL, THE WEATHER TYPE OF SLEET IS REALLY GRAUPEL OR
SNOW PELLETS.
RECENT HRRR AND NAM MODEL OUTPUT THEN SHOW POST FRONTAL COOLING
PRODUCING NO MORE THAN SCATTERED LIGHT SNOW SHOWERS, MAINLY NORTH
AND MOUNTAINS. ANY SNOW ACCUMULATIONS WILL BE LESS THAN 0.5
INCHES.
BASED ON RECENT NAM AND HRRR MODEL VALUES, FORECASTED LOW
TEMPERATURES TO BE NEAR NORMAL,
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
ON MONDAY, SREF MODEL OUTPUT SHOWS THE UPPER JETSTREAM FLOW BACKING
SLIGHTLY INTO THE WEST SOUTHWEST. HENCE THE NEXT SHORT WAVE WILL
TO PASS EASTWARD THROUGH THE GREAT LAKES SHOULD HAVE LESS IMPACT
ON THE UPPER OHIO VALLEY. STILL INCLUDED A CHANCE OF SHOWERS OF
SNOW, BUT MAINLY NORTH. REST OF THE UPPER OHIO VALLEY WILL STAY
DRY THROUGH DAYTIME TUESDAY.
SREF MODEL OUTPUT THEN SHOWS THE NORTHERN JETSTREAM BRANCH GAINING
MORE INFLUENCE. THIS WILL STEER A LOW PRESSURE SYSTEM TO MOVE
SOUTHEAST FROM THE CANADIAN ROCKIES TO PUSH A COLD FRONT WITH RAIN
SHOWERS THROUGH THE UPPER OHIO VALLEY DAYTIME WEDNESDAY.
FORECAST TEMPERATURES THIS PERIOD USING BLEND OF GFS AND NAM MOS.
THIS GUIDANCE SHOWED HIGHS MONDAY TO BE 2-3 DEGREES WARMER THAN
NORMAL, AND LOWS AND HIGHS TUESDAY AND WEDNESDAY TO BE NEARLY 15
DEGREES WARMER THAN NORMAL.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS WAS THE CASE YESTERDAY...MODELS CONTINUE TO HAVE TROUBLE
RESOLVING THE PLACEMENT AND TIMING OF SYSTEMS DURING THIS PERIOD.
WHILE ALL THE MODELS CONTINUE TO SUGGEST A DEEPENING LONG WAVE
PATTERN...WITH A STRONG RIDGE OVER THE WESTERN U.S AND A DEEP TROUGH
OVER THE EASTERN U.S...THE SHORTWAVE PATTERN AND IN TURN LOW
PLACEMENT REMAINS INCONSISTENT FROM RUN TO RUN.
IN GENERAL...MODELS SUGGEST THAT THE COLD FRONT...PROGGED TO CROSS
THE OHIO VALLEY DURING THE DAY WEDNESDAY...WILL HANG UP AROUND THE
MASON-DIXON LINE AND EVENTUALLY MOVE NORTHWARD AS A WARM FRONT. THE
QUESTION IS WHEN AND HOW FAR NORTH WILL THE SYSTEM MAKE IT AT THIS
POINT.
CONTINUED TO REMAIN CLOSE TO HPC GUIDANCE WITH ONLY LOW CHANCE POPS
THROUGH MOST OF THE PERIOD WITH SUCH MODEL UNCERTAINTY AND
TEMPERATURES CLOSE TO AN HPC MEX BLEND.
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL CONTINUE FOR A FEW MORE HOURS BEFORE ANOTHER
FAST MOVING COLD FRONT IMPACTS THE TERMINALS LATER THIS AFTERNOON.
MAINTAINED MOSTLY MVFR CIGS/VSBY AT ALL SITES WITH THE SYSTEM...BUT
IFR VSBY WILL BE POSSIBLE IN SNOW SHOWERS ESPECIALLY AT KFKL AND
KDUJ. WILL GRADUALLY IMPROVE SITES BACK TO VFR OVERNIGHT PER SREF
AND LAMP GUIDANCE HOWEVER...STRATOCUMULUS MAY REMAIN UNTIL MONDAY
MORNING AS W-NW WINDS ALLOWING FOR SOME LAKE INDUCED CLOUDS.
OUT AHEAD OF AND JUST BEHIND THE SYSTEM WINDS WILL VEER FROM S-SW TO
MORE W-NW AND INCREASE TO NEAR 15-20KTS SUSTAINED WITH GUSTS TO
35KTS POSSIBLE.
OUTLOOK...MONDAY THROUGH FRIDAY...
ANOTHER CLIPPER TYPE SYSTEM MAY CAUSE SOME RESTRICTIONS TO THE
NORTHERN TAF SITES MONDAY AFTERNOON BUT MOISTURE IS RATHER LIMITED.
ELSEWHERE...VFR IS EXPECTED THROUGH WEDNESDAY. A COLD FRONT WILL
THEN BRING A GREATER CHANCE FOR RESTRICTIONS AT ALL SITES WEDNESDAY
AND THURSDAY. RESTRICTIONS MAY BE POSSIBLE FRIDAY BUT THERE IS MUCH
UNCERTAINTY IN THE FORECAST AT THIS POINT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR MDZ001.
OH...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR OHZ039>041-
048>050-057>059-068-069.
PA...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR PAZ007>009-
013>016-020>023-029-031-073>076.
WV...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR WVZ001>004-012-
021>023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1216 PM EST SUN JAN 29 2012
.SYNOPSIS...
A FAST MOVING COLD FRONT WILL BRING GUSTY WINDS AND A MIX OF LIGHT RAIN
SLEET AND SNOW SHOWERS INTO EARLY EVENING. HIGH PRESSURE PASSING
TO THE SOUTH WILL THEN PROVIDE DRY SEASONABLE CONDITIONS MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AFTERNOON UPDATE, BASED ON BLEND OF RECENT SURFACE AND SATELLITE
DATA, AND HRRR AND NAM MODEL OUTPUT, HAS ADJUSTED ONSET TIMING OF
FRONTAL BAND OF SHOWERS TO MID AND LATE AFTERNOON. PER NAM MODEL
PROFILES, WHICH SHOW DEEP BUT NARROW INSTABILITY, HAVE ADDED
MENTION OF A SLIGHT CHANCE OF SLEET. THIS WILL BE SIMILAR TO WHAT
HAPPENED YESTERDAY AFTERNOON.
IN REALITY, THE WEATHER TYPE IS REALLY GRAUPEL OR SNOW PELLETS,
BUT CALLING IT SLEET WILL SUFFICE.
LIKEWISE HAVE ADJUSTED WIND GUSTS, MAINTAINING WIND ADVISORY FOR
THE HIGHER MOUNTAINS. WILL CONTINUE TO MONITOR THIS SITUATION AS
RECENT HRRR MODEL OUTPUT DID SHOW GUSTS TO 45-50 MPH POSSIBLE WITH
THE COLD FRONTAL PASSAGE.
EXPECT TEMPERATURES TO BE A BIT COLDER THAN SATURDAY, HENCE LIGHT SNOW
SHOWERS CAN OCCUR FARTHER SOUTH THIS AFTERNOON. HOWEVER, MOST
TEMPERATURES WILL BE WARMER THAN FREEZING, SO SNOW ACCUMULATIONS
WILL AGAIN BE MINIMAL. AS THE UPPER LEVEL SHORT WAVES MOVES OFF
RAPIDLY TO THE EAST TONIGHT...SNOW SHOWERS WILL END.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
ON MONDAY, WITH UPPER JETSTREAM FLOW BACKING SLIGHTLY INTO THE
WEST SOUTHWEST, THE NEXT SHORT WAVE WILL TO PASS EASTWARD THROUGH
THE GREAT LAKES MAY HAVE LESS IMPACT ON THE UPPER OHIO VALLEY.
STILL INCLUDED A CHANCE OF SHOWERS OF RAIN AND SNOW, BUT MAINLY
NORTH.
FORECAST HIGHS MONDAY TO BE 2-3 DEGREES WARMER THAN SUNDAY.
RECENT ECMWF MODEL OUTPUT SHOWS A DRY BREAK MONDAY NIGHT AND
TUESDAY WITH SOUTHWEST WINDS PROVIDING A WARM UP TO 10 DEGREES
ABOVE NORMAL, PER GFS AND NAEFS VALUES.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MODELS ARE IN FAIRLY GOOD AGREEMENT ON A COLD FRONT PASSAGE
WEDNESDAY AS THE ASSOCIATED LOW PRESSURE SYSTEM CROSSES NORTH OF THE
GREAT LAKES. BEYOND WEDNESDAY...THERE ARE INCONSISTENCIES FROM
RUN TO RUN WITH THE DETERMINISTIC MODELS KEEPING CONFIDENCE
RELATIVELY LOW ESPECIALLY INTO FRIDAY AND SATURDAY.
ALL MODELS SUGGEST A GRADUAL DEEPENING LONG WAVE TROUGH OVER THE
CENTRAL U.S WITH THE GFS THE STRONGEST AND THE ECMWF AND GEFS
ENSEMBLES REMAINING LESS AMPLIFIED. THIS IN TURN MAKES LOW
PLACEMENT SIGNIFICANTLY DIFFERENT BETWEEN THE MODELS. WITH SUCH A
WIDE SPREAD...OPTED TO REMAIN CLOSE TO HPC GUIDANCE FOR THE PERIOD
FROM THURSDAY THROUGH SATURDAY...WHICH IS CLOSEST TO THE 00/12Z
ECMWF AND GEFS. THIS WOULD BRING A SURFACE LOW SOUTH ALONG THE
APPALACHIANS AND OFF THE COAST BY FRIDAY.
KEPT TEMPERATURES CLOSE TO AN HPC MEX BLEND WHICH SEEMED TO MATCH UP
WELL WITH NAEFS TRENDS.
&&
.AVIATION /17Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS WILL CONTINUE FOR A FEW MORE HOURS BEFORE ANOTHER
FAST MOVING COLD FRONT IMPACTS THE TERMINALS LATER THIS AFTERNOON.
MAINTAINED MOSTLY MVFR CIGS/VSBY AT ALL SITES WITH THE SYSTEM...BUT
IFR VSBY WILL BE POSSIBLE IN SNOW SHOWERS ESPECIALLY AT KFKL AND
KDUJ. WILL GRADUALLY IMPROVE SITES BACK TO VFR OVERNIGHT PER SREF
AND LAMP GUIDANCE HOWEVER...STRATOCUMULUS MAY REMAIN UNTIL MONDAY
MORNING AS W-NW WINDS ALLOWING FOR SOME LAKE INDUCED CLOUDS.
OUT AHEAD OF AND JUST BEHIND THE SYSTEM WINDS WILL VEER FROM S-SW TO
MORE W-NW AND INCREASE TO NEAR 15-20KTS SUSTAINED WITH GUSTS TO
35KTS POSSIBLE.
OUTLOOK...MONDAY THROUGH FRIDAY...
ANOTHER CLIPPER TYPE SYSTEM MAY CAUSE SOME RESTRICTIONS TO THE
NORTHERN TAF SITES MONDAY AFTERNOON BUT MOISTURE IS RATHER LIMITED.
ELSEWHERE...VFR IS EXPECTED THROUGH WEDNESDAY. A COLD FRONT WILL
THEN BRING A GREATER CHANCE FOR RESTRICTIONS AT ALL SITES WEDNESDAY
AND THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR MDZ001.
OH...NONE.
PA...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR PAZ074-076.
WV...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
449 PM EST SUN JAN 29 2012
.SHORT TERM /TONIGHT AND MONDAY/...
WV IMAGERY AND RUC ANALYSIS SHOWS THE UPPER TROUGH THAT HAS BEEN
OVER THE UPPER GREAT LAKES OVER THE LAST DAY STARTING TO SHIFT TO
THE EAST. UPSTREAM...BROAD MOISTURE PLUME RUNNING OVER THE RIDGE
OVER THE US/CANADIAN ROCKIES AND MOVING INTO THE NRN PLAINS. CLOSER
TO HOME...VIS SATELLITE SHOWING LAKE EFFECT CLOUDS HANGING ON OVER
MUCH OF UPPER MICHIGAN...BUT DRIER AIR FROM THE APPROACHING SFC
RIDGE IN MN HAS QUICKLY ATE AWAY AT THE CLOUDS/SHOWERS OVER WRN LK
SUPERIOR. OVER THE ERN LK...LES CONTINUES...ALTHOUGH THE DRIER AIR
HAS STARTED TO DIMINISH THE INTENSITY OF THE SHOWERS...WHICH KMQT
RADAR IS SHOWING MAINLY 1HR SNOWFALL RATES OF 0.5 IN/HR. THE
STRONGEST SWRN BAND NEAR MUNISING HAS PICKED UP SLIGHTLY OVER THE
LAST HOUR...AS LLVL WINDS OFF MARQUETTE COUNTY HAVE SHIFTED SLIGHTLY
TO THE WNW AND INCREASED CONVERGENCE.
TONIGHT...WITH THE UPPER TROUGH CONTINUING TO PUSH E...SFC RIDGE
CURRENTLY OVER THE MN WILL PUSH INTO THE AREA. H850-700 SUBSIDENCE
AND DRY AIR ALREADY TAKEN HOLD OVER WRN LK SUPERIOR AND DIMINISHED
THE -SHSN OVER THE WRN CWA. AS SFC HIGH BUILDS INTO UPPER MI THIS
EVENING...WINDS WILL BE BACKING THROUGH THE EVENING HOURS AND END UP
FOCUSING ANY LINGERING LES OVER THE KEWEENAW PENINSULA BY MIDNIGHT.
SINCE INVERSION HEIGHTS ON BUFKIT SOUNDINGS OVER THE KEWEENAW ARE
ONLY AROUND 3KFT...DON/T EXPECT MUCH FOR ACCUMULATIONS...ESPECIALLY
WITH THE TRANSIENT NATURE OF THE LES.
OVER ERN ALGER AND LUCE COUNTIES...EXPECT LES TO BE ONGOING AT THE
START OF THE TONIGHT PERIOD WITH THE NW FLOW AND -18C H850 TEMPS.
DEEPER MOISTURE WILL DEPART LATE THIS AFTN AS SUBSIDENCE FROM
H850-700 WITH THE UPPER RIDGING WILL CAUSE INVERSION HEIGHTS TO FALL
TO 4-5KFT. STILL SHOULD SEE LES CONTINUING IN THE NW WIND SNOW BELTS
FROM MUNISING E THIS EVENING...BUT INTENSITY WILL BE LOWER THAN
TODAY. IN ADDITION...WITH WINDS BACKING TO THE W BY MIDNIGHT AND
THEN SW BY DAYBREAK...THE BANDS SHOULD BE SHIFTING TO THE ENE FROM
LATE EVENING ON. THUS...EXPECT LIMITED ACCUMULATION DUE TO THE
TRANSIENT NATURE OF THE BANDS AND WILL LET THE WARNING CONTINUE
UNTIL 00Z.
LOWS TONIGHT ARE VERY TRICKY...SINCE CLEARING SKIES...WEAKENING
WINDS WITH THE SFC RIDGE...AND PWATS AROUND 35 PERCENT OF NORMAL
LEAD TO A FAVORABLE RADIATION COOLING NIGHT. FORECAST IS DIFFICULT
DUE TO THE APPROACHING HIGH CLOUDS CURRENTLY MOVING INTO WRN MN.
THESE SHOULD START TO ARRIVE AFTER MIDNIGHT AND CAUSE FOR STEADY OR
RISING TEMPS LATE. WENT WITH A NON-DIURNAL TREND AND HAVE LOWS ALONG
THE WI BORDER IN THE MID SINGLE DIGITS BELOW ZERO AND WOULD NOT BE
SURPRISED IF THEY GET EVEN COLDER IF CLOUDS ARE DELAYED.
LATE TONIGHT INTO MONDAY...CLIPPER SYSTEM CURRENTLY TAKING SHAPE IN
ALBERTA WILL SLIDE A WARM FRONT ACROSS MN AND WI ON MON. H700-500
WAA AND MOISTURE...ALONG WITH ISENTROPIC ASCENT ON THE 275-300K SFCS
PUSHES ACROSS THE AREA FROM SW TO NE BETWEEN 09Z AND 18Z MON. BEST
MID LVL WAA LOOKS TO FOCUS OVER THE S HALF OF UPPER MI...MAINLY OVER
THE SCNTRL AND ALONG THE LK MI SHORELINE. WILL FOLLOW THAT SOLN FOR
QPF AMNTS FOR LATE TONIGHT INTO MON MORNING. WITH A GOOD CONSENSUS
ON FORCING/QPF/TIMING...HAVE BUMPED POPS UP TO LIKELY FOR MOST OF
THE LAND AREAS.
12Z NAM/GFS/GEM-REG CONSISTENT ON 0.12-0.2IN OF QPF OVER THE SRN
HALF OF UPPER MI BY MON EVENING AND MADE SOME MINOR ADJUSTMENTS UP
FROM PREVIOUS SHIFT. COBB OUTPUT FOR KESC/KIMT SHOWING HIGH RATIOS
AROUND 15/18-1 INITIALLY...THEN FALLING BELOW 10-1 HEADING INTO THE
AFTN AS THE DEEPER MOISTURE IS CUT OUT REMAINING FORCING/MOISTURE IS
BELOW THE DGZ. THINK MUCH OF THE SNOW WILL FALL IN THE HIGHER SNOW
RATIO PERIOD AND USED THAT AS THE STARTING POINT FOR SNOWFALL.
EXPECT A PERIOD OF LK ENHANCEMENT AFTER 15Z ON MON...WHEN LLVL
MOISTURE PROFILES FINALLY MOISTEN UP AND SRLY WINDS TAKE HOLD. WITH
H850 TEMPS AROUND -11C DURING THE PCPN PERIOD...SHOULD BE ENOUGH
LLVL INSTABILITY TO PROVIDE ENHANCEMENT OVER DELTA/SCHOOLCRAFT/LUCE
COUNTIES AND HAVE BUMPED UP QPF AMNTS SLIGHTLY IN THOSE
AREAS...ESPECIALLY SCHOOLCRAFT/LUCE. OVERALL...HAVE A GENERAL 1-2IN
OVER MUCH OF THE CWA. COULD BE SOME ISOLATED ADVY AMNTS OF 3IN OVER
THE SCNTRL AND ALONG THE LK MI SHORELINE...BUT THE OVERALL AVG WILL
BE BELOW ADVY AND WILL NOT ISSUE ANYTHING AT THIS TIME.
FINALLY...WITH THE MAIN FORCING AND DEEPER MOISTURE PULLING NE IN
THE AFTN...COULD SEE A PERIOD OF FZDZ. THIS IS DUE TO THE LINGERING
FORCING/MOISTURE BELOW THE ICE CRYSTAL AREA /ISENTROPIC ASCENT ON
275-280K SFCS AND H925-800 MOISTURE/. ADDED THIS TO THE GRIDS IN THE
AFTN FROM SW TO NE AS THE DEEP MOISTURE PULLS OUT...AND MAY BE MOST
PRONOUNCED OVER THE HIGHER TERRAIN NCNTRL...WHERE THE SSE UPSLOPE
FLOW WOULD FAVOR IT.
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
BIG FCST QUESTION FOR MONDAY NIGHT INTO TUESDAY TIME FRAME WILL BE
THE POTENTIAL FOR FZDZ IN THE WAKE OF MONDAYS TROUGH/WARM FRONT.
FCST SNDGS...ESPECIALLY THE NAM BUFR SNDGS...SHOW LINGERING SHALLOW
MOIST LAYER NEAR THE SFC AS DRYING/SUBSIDENCE OCCURS IN MID-LVLS IN
THE WAKE OF THE WARM FRONT. EXPECT LOCATIONS AFFECTED BY AN UPSLOPE
SRLY FLOW WILL BE MOST SUSCEPTIBLE TO PATCHY FZDZ MON NIGHT INTO
TUESDAY MORNING BUT WILL INCLUDE A MENTION FOR MOST OF THE CWA. ANY
LINGERING FZDZ SHOULD TURN TO DZ TUE AFTERNOON AS MOIST LOW-LVLS
WARM ABV FREEZING.
ANOTHER SHORTWAVE AND ASSOC COLD FRONT WILL MOVE THROUGH TUE
AFTERNOON AND TUE NIGHT. TRACK OF THE SHORTWAVE AND THE ASSOC SFC
LOW WOULD FAVOR MAINLY THE NRN TIER FOR SOME LIGHT RAIN OR SNOW AS
THIS IS WHERE MODELS INDICATE DEEPER MOISTURE AND CLOSER PROXIMITY
TO MODERATE Q-VECT CONV AND LIFT ASSOC WITH SHORTWAVE. RAIN/SNOW MIX
ALONG THE NRN TIER SHOULD TURN OVER TO ALL SNOW LATE TUE NIGHT WITH
CAA BEHIND FRONT AND WOULD EXPECT A DIMINISH TREND AS SHORTWAVE/SFC
LOW DEPART QUICKLY EAST.
WEAK RDGG BUILDING IN FROM THE WEST SHOULD RESULT IN MAINLY DRY
CONDITIONS ON WEDNESDAY.
FOR THE EXTENDED /THURSDAY THROUGH SUNDAY/...
MODEL DISAGREEMENTS WILL CONTINUE THROUGHOUT THE REMAINDER OF THE
FORECAST PERIOD PERTAINING TO THE LOCATION AND TIMING OF SHORTWAVES
AFFECTING THE AREA...SO HAVE NOT DIVERGED MUCH FROM CONSENSUS THIS
FAR OUT. MODELS ARE IN FAIRLY GOOD AGREEMENT...HOWEVER...THAT STRONG
RIDGING OFF THE PACIFIC NORTHWEST WEDNESDAY NIGHT/THURSDAY MORNING
WILL ALLOW THE JET STREAM TO TRANSITION TO A MERIDIONAL FLOW ON THE
DESCENDING BRANCH...CREATING AN ENHANCED TROUGHING PATTERN OVER THE
CENTRAL CONUS. GFS IS THE MOST PROGRESSIVE OF THE MODELS...KEEPING
THE TROUGH PLACEMENT FARTHER NORTH AND HAVING IT MOVE EAST MORE
QUICKLY THAN ECMWF/GEM. AS HIGH PRESSURE CONTINUES TO BUILD IN WEST
THROUGH SUNDAY...DESCENDING BRANCH OF TROUGH WILL BEGIN TO
RETROGRADE AND BECOME POSITIVELY TILTED.
TRANSLATING THIS TO THE UPPER GREAT LAKES REGION...OVERALL...THIS
WILL CREATE A FAIRLY BENIGN SYNOPTIC WEATHER PATTERN AS MUCH OF THE
SHORTWAVES WILL PASS TO OUR SOUTH TRAVERSING THE DESCENDING EDGE OF
THE TROUGH. HOWEVER...IF THE MORE NORTHERN PLACEMENT OF THE GFS PANS
OUT...AS THE TROUGH BECOMES POSITIVELY TILTED OVER THE UPPER GREAT
LAKES ON FRIDAY...EXPECT SHORTWAVE TO DEVELOP AND TRAVERSE THE AREA.
THIS WILL BRING THE BEST CHANCE FOR PRECIP DURING THE PERIOD
WITH STRONG QVECTOR CONVERGENCE AND FAIRLY MOIST PROFILE/STEEP LAPSE
RATES DURING ITS PASSAGE. THE ECMWF AND THE GEM ON THE OTHER HAND
HAVE THIS SYSTEM DEVELOPING MUCH FARTHER SOUTH AND THEREBY NOT
IMPACTING THE FORECAST PERIOD AT ALL...SO DIDN`T GO ANY HIGHER THAN
SLIGHT CHANCES. OTHERWISE...PREDOMINATE W AND SW WINDS ALOFT AHEAD
OF DESCENDING JET WILL KEEP TEMPERATURES WELL ABOVE NORMAL THURSDAY.
WITH LOW CONFIDENCE ON PLACEMENT AND STRENGTH OF JET AS IT NEARS THE
AREA...WILL KEEP WITH THE LOWERING TREND OF TEMPS AS WINDS TURN MORE
NORTHERLY BY THE END OF THE PERIOD...BUT MAGNITUDE OF THIS COLD AIR
INTRUSION IS YET TO BE DETERMINED. IF THE MORE AMPLIFIED TROF AND
COLDER SOLN OF THE ECMWF SOLUTION VERIFIES...THEN TEMPS WILL
PROBABLY NEED TO BE LOWERED AND POPS MAY NEED TO BE INCREASED FOR
NEXT WEEKEND FOR AREAS DOWNWIND OF LAKE SUPERIOR IN N-NW FLOW.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
LES WILL DIMINISH AT ALL OF THE TAF SITES THROUGH THE AFTERNOON AND
LEAD TO IMPROVING CONDITIONS...TOWARDS VFR. THE SITE THAT MAY BOUNCE
BETWEEN VFR/MVFR THROUGH THE AFTN INTO THE OVERNIGHT HOURS IS
KCMX...DUE TO WINDS BACKING TO A FAVORABLE WRLY DIRECTION. THIS WILL
LIKELY LEAD TO ANOTHER PERIOD OF LOWER VSBYS TOWARDS MIDNIGHT.
ATTENTION THEN TURNS TO WARM FRONT APPROACHING THE AREA LATE TONIGHT
INTO MON. SNOW AHEAD OF THIS FRONT WILL SPREAD FROM SW TO NE ACROSS
UPPER MI...IMPACTING KIWD BEFORE DAY BREAK AND KSAW/KCMX MID-LATE
MORNING. SHOULD SEE VSBYS DROPPING TO ALT LANDING MINS AS THIS SNOW
MOVES INTO THE AREA...ESPECIALLY AT KIWD.
&&
.MARINE /FOR THE 4PM LAKE SUPERIOR FORECAST ISSUANCE/...
HIGH PRESSURE RIDGE SHIFTING OVER LAKE SUPERIOR TONIGHT WILL BRING
DECREASING WINDS TONIGHT...BELOW 20KTS. A CLIPPER SYSTEM DEVELOPING
IN ALBERTA WILL BEGIN TO MOVE INTO THE NORTHERN PLAINS ON MONDAY
AFTERNOON AND EVENING BEFORE MOVING ACROSS THE UPPER GREAT LAKES ON
TUESDAY NIGHT. SOUTHERLY WINDS AHEAD OF THIS SYSTEM COULD PRODUCE
GUSTS TO 30KTS OVER THE ERN LK ON MONDAY AFTN AND EVENING. THE LOW
WILL SHIFT E ON WED...ALLOWING WEAK HIGH PRESSURE TO BUILD OVER THE
UPPER GREAT LAKES THROUGH THURS. A LOW PRESSURE SYSTEM WILL MOVE
THROUGH THE OHIO RIVER VALLEY ON FRI...BUT SHOULD HAVE LIMITED
EFFECTS ON LK SUPERIOR. EXPECT WINDS TO BE BELOW 25KTS FROM TUESDAY
MORNING THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST THIS EVENING FOR MIZ006-
007-085.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...VOSS
EXTENDED...JMW
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1252 PM EST SUN JAN 29 2012
LATEST UPDATE...AVIATION...
.SYNOPSIS...(415 AM EST SUN JAN 29 2012)
ANOTHER WAVE OF LOW PRESSURE WILL ZIP BY THE AREA THIS MORNING...AND
WILL BRING ANOTHER ROUND OF SNOW TO THE AREA. THE HIGHEST
ACCUMULATIONS WILL BE ACROSS THE SOUTHWEST CORNER OF THE AREA...
INCLUDING ALLEGAN...HASTINGS...AND KALAMAZOO. 2 TO LOCALLY 4 INCHES
OF ADDITIONAL ACCUMULATION IS LIKELY FOR THESE AREAS WILL LESS
ELSEWHERE. A BRIEF BREAK IN THE WEATHER IS EXPECTED TONIGHT...BEFORE
A FRONT MOVES IN ACROSS THE AREA ON MONDAY. THIS WILL INITIALLY
BRING LIGHT SNOW TO THE AREA...WITH IT CHANGING OVER TO RAIN BY
MONDAY EVENING. MUCH WARMER TEMPERATURES IN THE 40S CAN BE EXPECTED
BY TUESDAY.
&&
.SHORT TERM...(852 AM EST SUN JAN 29 2012)
(TODAY THROUGH TUESDAY)
THE WINTER WEATHER ADVISORY IS ON TRACK.
BASED ON THE LATEST IR AND WATER VAPOR LOOPS PLUS OUR RADAR MOSAIC
WITH CONSIDERATION TO THE 10Z HRRR IT SEEMS THE HEAVIEST SNOWFALL IN
THE NEXT THREE HOURS (TILL NOON) WILL BE OVER OTTAWA...SOUTHERN
KENT...NORTHERN ALLEGAN AND BARRY COUNTIES AS THAT IS WERE THE
DEFORMATION BAND SEEMS TO BE SETTING UP. BASED ON THIS THE ADVISORY
AS IT IS SEEMS FINE. I WOULD EXPECT SNOWFALL RATES OF UP TO AN INCH
AN HOUR IN THOSE FOUR COUNTIES.
REST OF THE EARLIER DISCUSSION...WE SHOULD SEE THE SYSTEM IN THE
PROCESS OF MOVING EAST OF THE AREA AT 18Z...AND IT SHOULD BE GONE BY
21Z. W/NW FLOW WILL HOLD IN AND DELTA T/S WILL REMAIN IN THE MID
TEENS. THIS WOULD SUPPORT ONGOING LAKE EFFECT WITH ACCUMS. HOWEVER
SUBSIDENCE IN THE WAKE OF THE MORNING WAVE WILL LOWER INVERSION
HEIGHTS TO AROUND 3K FT ALONG WITH THE UPPER FLOW EXPECTED TO BE
TRANSITIONING TO ANTI-CYCLONIC. THE LATTER FACTORS MENTIONED LOOK TO
BE SIGNIFICANT ENOUGH TO DIMINISH LAKE EFFECT CHCS LATE THIS
AFTERNOON INTO THE EVENING. THE FLOW WILL TRANSITION FROM W/NW TO SW
BY OVERNIGHT TONIGHT.
AFTER A SHORT BREAK WITH LAKE EFFECT WINDING DOWN...AND SFC RIDGING
MOVING ACROSS TONIGHT...WE WILL SEE PCPN CHCS INCREASE DURING THE
DAY ON MON. THIS OCCURS AS HEIGHTS BUILD...AND AN ELEVATED
BAROCLINIC/FRONTAL ZONE PUSHES TO THE NE AS AN ELEVATED WARM FRONT.
ALL MODELS ARE BREAKING OUT PCPN ALONG THE FRONT ACROSS CENTRAL AND
NRN LOWER MI. THE BETTER CHC OF PCPN WILL BE AS YOU HEAD FURTHER TO
THE NE AS PCPN BECOMES MORE ORGANIZED. PCPN WILL START OUT AS ALL
SNOW THE FIRST PART OF MON. PCPN WILL TRANSITION TO MORE LIQUID THEN
MON AFTERNOON AS WARMER AIR ALOFT MOVES IN...AND WE GET SOME
BOUNDARY LAYER HEATING. WE COULD SEE SOME SLEET MIX IN MON AFTERNOON
AS A SMALL COLD LAYER AROUND 1-3K FT AGL WILL TAKE SHAPE RESULTING
FROM THE SFC HEATING AND THE WAA ALOFT.
THE FRONT MOVES OUT MON EVENING...LEAVING LOWER MICHIGAN DRY UNTIL
TUE AFTERNOON AS WE SEE THE PV ANOMALY/UPPER WAVE APPROACH. PCPN IN
THE FORM OF LIGHT RAIN/SHOWERS WILL DEVELOP TUE AFTERNOON WHEN WE
SEE GOOD WARM AND MOIST ADVECTION AND THE SYNOPTIC FORCING MOVE IN
AHEAD OF THE WAVE.
&&
.LONG TERM...(415 AM EST SUN JAN 29 2012)
(TUESDAY NIGHT THROUGH SATURDAY)
HAVE OPTED TO FOLLOW THE GFS THROUGH THE LONG TERM. THE ECMWF SPINS
UP A SYSTEM AND PUSHES SIGNIFICANT PRECIPITATION INTO THE SOUTHERN
GREAT LAKES ON THURSDAY. THE PMDHMD DISCUSSION FROM HPC FAVORS THE
GFS AT 84 HOURS EXPLAINING THAT THE ECMWF AS AN OUTLIER. WITH THIS
IN MIND...THE GFS HAS A FAIRLY BENIGN LONG TERM PERIOD.
A COLD FRONT SLIDES EAST ACROSS LOWER MICHIGAN TUESDAY NIGHT WITH
RAIN. 850MB TEMPERATURES APPEAR WARM ENOUGH FOR MAINLY RAIN BEFORE
THE PRECIPITATION SHUTS OFF ALONG THE FRONT OVERNIGHT.
BEYOND TUESDAY NIGHT...HAVE A DRY FORECAST WEDNESDAY THROUGH
SATURDAY. FAIRLY TOUGH TO HAVE A DRY FORECAST THIS TIME OF YEAR IN
THE MID LATITUDES...BUT NOTHING SIGNIFICANT ENOUGH TO INCLUDE IN THE
FORECAST AT THIS TIME. THE PATTERN ESSENTIALLY IS ZONAL TO BEGIN THE
LONG TERM TRENDING TOWARD AND UPPER TROUGH BY LATE IN THE WEEK.
A WEAK SHORTWAVE ALOFT PASSES THROUGH THE AREA ON THURSDAY...BUT
VERY LIMITED MOISTURE SHOULD KEEP US DRY. ANOTHER SHORTWAVE PASSES
WELL OFF TO OUR SOUTH THURSDAY NIGHT AND FRIDAY AGAIN MISSING THE
AREA WITH PRECIPITATION.
TEMPERATURES THROUGH THE PERIOD WILL BE ABOVE NORMAL WITH HIGHS UP
AROUND 40 DURING THE WEEK. BY SATURDAY...COLDER AIR IS FILTERING IN
WITH THE DEEPENING TROUGH. TEMPS OVER THE WEEKEND LOOK TO BE
TRENDING BACK TOWARD NORMALS.
&&
.AVIATION...(1252 PM EST SUN JAN 29 2012)
IFR/LIFR WAS IMPACTING THE TAF SITES AS OF 1730Z IN MODERATE TO
HEAVY SNOW. SNOWFALL WILL DIMINISH FROM WEST TO EAST OVER THE THREE
HOURS...MOVING OUT OF THE JXN AREA BY 21Z. IMPROVEMENT FROM THE
WEST...BEHIND THE SNOW...WILL BE QUICK WITH VFR CONDITIONS
DEVELOPING WITHIN A COUPLE HOURS AFTER THE SNOW HAS ENDED. VFR IS
EXPECTED TO CONTINUE THROUGH THE OVERNIGHT PERIOD.
ANOTHER AREA OF SNOW IS EXPECTED TO SPREAD INTO THE AREA MONDAY
MORNING. THIS APPEARS TO BE MOST LIKELY ACROSS THE NORTHERN TAF
SITES...ALONG I-96. IFR WILL LIKELY REDEVELOP THERE AFTER 15Z
MONDAY. IFR WILL ALSO BE POSSIBLE ALONG I-94...HOWEVER IT SHOULD BE
SLIGHTLY LATER AND SHOULD BE MORE PATCHY. THE SNOW SHOULD BEGIN TO
SWITCH OVER TO A MIX RAIN/SNOW AFTER 18Z.
&&
.MARINE...(415 AM EST SUN JAN 29 2012)
WE WILL MAINTAIN THE SMALL CRAFT ADVISORY THAT REPLACED THE GALE
WARNING LAST EVENING. WINDS HAVE COME DOWN A FAIR AMOUNT SINCE THE
EVENING UPDATE...AND THE THREAT FOR GALES HAS ENDED. WE MAY DROP
BELOW THE WIND CRITERIA FOR SMALL CRAFT ADVISORIES THIS
AFTERNOON...HOWEVER WAVES WILL REMAIN UP UNTIL THE WINDS INCREASE
AGAIN LATER TODAY. THE SAME THING WILL LIKELY HAPPEN TONIGHT INTO
MONDAY. WE WILL HOLD THE SCA THROUGH 12Z MON...AND THIS WILL MOST
LIKELY NEED TO BE EXTENDED AT SOME POINT.
&&
.HYDROLOGY...(415 AM EST SUN JAN 29 2012)
ONLY POTENTIAL HYDROLOGY ISSUE THIS WEEKEND WOULD BE SOME ICE
DEVELOPMENT/ICE JAMS AS SOMEWHAT COLDER AIR HAS MOVED IN PLACE. THIS
AIR IS NOT SIGNIFICANTLY COLD...AND WE SHOULD NOT DEVELOP A LOT OF
ICE.
THE OTHER ISSUE THAT COULD DEVELOP WOULD BE INCREASING RIVER LEVELS
DUE TO MELTING SNOW WITH THE WARMER TEMPERATURES MOVING IN AND
MELTING SNOW ALONG WITH SOME RAIN. WE DO NOT HAVE A SIGNIFICANT
SNOWPACK IN PLACE...AND WE ARE NOT EXPECTING SIGNIFICANT AMOUNTS OF
RAIN. THIS SHOULD KEEP THE FLOODING POTENTIAL FAIRLY LOW THROUGH MID
WEEK.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY FOR OTTAWA...KENT...IONIA...
ALLEGAN...BARRY...EATON...VAN BUREN...KALAMAZOO AND CALHOUN
COUNTIES.
LM...SMALL CRAFT ADVISORY IN EFFECT THROUGH 7 AM MONDAY FOR THE
ENTIRE NEARSHORE.
&&
$$
SYNOPSIS: NJJ
SHORT TERM: NJJ WDM
LONG TERM: DUKE
AVIATION: JK
MARINE: NJJ
HYDROLOGY: NJJ
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
339 PM CST SUN JAN 29 2012
.DISCUSSION...
ANOTHER MILD WEEK IS AHEAD OF US...WITH HIGHS IN THE MID 30S TO
LOWER 40S COMING FOR MONDAY THROUGH THURSDAY. IMPRESSIVE WARM
FRONT COMING THROUGH TONIGHT WILL BRING ABOUT THE CHANCE FOR
ANOTHER DUSTING OF SNOW...WHILE A LOW PASSING ACROSS NRN MN
TUESDAY MAY BRING SOME LIGHT PRECIP TO NRN SECTIONS OF THE CWA.
AFTER THAT...THE REST OF THE FORECAST IS DRY...WITH ONLY A MODEST
COOL DOWN EXPECTED FOR THE WEEKEND.
STRONG WARM FRONT THIS AFTERNOON STRETCHES FROM KC TO NE MONTANA.
TO GO ALONG WITH THIS...UPPER RIDGE IS WORKING INTO THE
PLAINS...WITH THE RUC SWINGING 160M 12 HR H5 HEIGHT RISES ACROSS
THE AREA THIS AFTERNOON. COMBINATION OF A SHORTWAVE MOVING INTO
MT...ALONG WITH STRONG ISENTROPIC/FGEN FORCING TO THE NORTH OF THE
FRONT HAS RESULTED IN THE GENERATION OF A NICE BAND OF SNOW ACROSS
NODAK. SHORT TERM HI RES GUIDANCE ALL SIMILAR WITH THIS BAND OF
SNOW REACHING THE NW CWA BETWEEN 2Z AND 4Z AND QUICKLY WORKING
EAST THROUGH THE NIGHT...EXITING THE WI CWA AROUND 15Z MON
MORNING. ONE ISSUE TO WATCH FOR TONIGHT IS A DRY LAYER OF AIR THAT
IS DEVELOPING THIS AFTERNOON BETWEEN H9 AND H7. INDICATIONS FROM
BUFKIT SOUNDINGS IS THAT WE WILL BE MOISTENING THIS LAYER FROM
TOP-DOWN...SO MUCH OF THE SNOW MAY BE LOST TO SUBLIMATION. ARW
1 KM AGL REFLECTIVITY FORECASTS ARE SPOTTY/NON-EXISTENT ACROSS
MUCH OF THE MPX CWA...AND THIS DRY LAYER LIKELY HAS A LOT TO DO
WITH IT. STILL...SREF PROBS ARE UP OVER 80 PERCENT FROM CENTRAL MN
INTO WRN WI...WHICH MATCHES UP WELL WITH BEST THALER QG FORCING.
THEREFORE...HAVE CATEGORICAL POPS ALONG AND NORTH OF AN
AXN/STC/EAU LINE FOR TONIGHT...WHERE FORCING AND MOISTURE LOOK
MOST LIKELY TO COINCIDE. CERTAINLY LOOKING GRIM FOR ANYONE ALONG
AND SOUTH OF THE MN RIVER TO SEE MUCH PRECIP. AS FOR
P-TYPE...STILL SEEING A SIGNIFICANT WARM NOSE COMING IN WITH THE
WARM FRONT...BUT MODELS CONTINUE TO SHOW THE PRECIP REMAINING OUT
AHEAD OF THE WARM NOSE...WITH ONLY AN HOUR OR TWO OF A WINTRY MIX
POSSIBLE AS THE PRECIP PULLS OUT. LOOKS TO BE YET ANOTHER SYSTEM
THIS YEAR THAT LAYS DOWN A QUICK HALF INCH TO AN INCH WHERE
CATEGORICAL POPS ARE LOCATED.
BESIDE THE PRECIP COMING IN...ALL GUIDANCE SIMILAR WITH A NON-
DIURNAL TREND FOR TONIGHT...WITH HIGHS STEADILY RISING THROUGH THE
NIGHT. IN FACT...GFSLAMP HAS ABOUT 10 DEGREES OF WARMING FOR ALL
MN LOCATIONS THROUGH THE NIGHT. EVEN IN WI...TEMPS SHOULD ONLY
FALL THROUGH ABOUT 3Z BEFORE GOING STEADY AND THEN RISING.
BIG QUESTION FOR MONDAY IS WHERE DOES THE WARM FRONT SET UP. 12Z
GUIDANCE HAS THE FRONT SOMEWHERE BETWEEN I-94 AND A HINCKLEY TO
FARGO LINE AT 6PM MONDAY. THIS WILL LEAD TO SOME UNCERTAINTY FOR
HIGHS ON MONDAY...AS AREAS SOUTH OF THE WARM FRONT WILL LIKELY
MAKE A RUN INTO THE 40S...WHILE AREAS ALONG AND NORTH REMAIN
CLOUDY WITH HIGHS LIKELY ONLY TOPPING OUT AROUND FREEZING. IN
ADDITION...THERE IS SOME CONCERN FOR DRIZZLE NORTH OF THE FRONT
GIVEN THE AMOUNT OF LOW LEVEL MOISTURE EXPECTED. HOWEVER...NAM/GFS
BUFKIT SOUNDINGS OVER CENTRAL MN SHOW A SHALLOW MIXED BOUNDARY
LAYER DEVELOPING DURING THE AFTERNOON...WITH A BIT OF A TEMP/DEWP
SPREAD NOTED ON THE SOUNDINGS. BECAUSE OF THIS...NOT TOO CONFIDENT
THAT WE WILL SEE THAT MUCH DZ GENERATION ACROSS CENTRAL
MN...DESPITE PERSISTENT LIFT ALONG THE FRONT. OTHER VARIABLE TO
CONTEND WITH FOR TEMPS ON MONDAY WILL BE SNOW COVER. SATELLITE
IMAGES THIS MORNING SHOWED MOST OF YELLOW MEDICINE AND LAC QUI
PARLE COUNTIES ARE SNOW FREE...AND GIVEN FAVORABLE WSW FLOW ON
MONDAY...PLACES SUCH AS MADISON AND MONTEVIDEO COULD SEE HIGHS TOP
OUT IN THE LOW 50S. SOUTH CENTRAL MN HAS THE OPPOSITE PROBLEM...AS
COOP OBSERVES THIS MORNING REPORTED 3 TO 5 INCHES OF SNOW ON THE
GROUND DOWN THERE...THIS MAY RESULT IN HIGHS BEING A BIT OVER DONE
DOWN THERE. AT ANY RATE...A BLEND OF THE MET/MAV BIAS CORRECTED
DATA WAS USED FOR HIGHS TOMORROW.
THE MILD CONDITIONS WILL REMAIN IN PLACE MONDAY NIGHT THROUGH
THURSDAY. MODELS SWING A COLD FRONT ACROSS THE AREA TUESDAY
MORNING...WITH LOWS IN THE WARM SECTOR OUT AHEAD OF IT MONDAY
NIGHT LIKELY STRUGGLING TO FALL BELOW FREEZING. H85 TEMPS LOOKS TO
ONLY GET KNOCKED DOWN TO AROUND 0C BEHIND THE FRONT...WITH HIGHS
TUESDAY THROUGH THURSDAY LOOKING TO BE A DEGREE OR TWO COLDER THAN
THE PREVIOUS DAY. IN FACT...OVERNIGHT LOWS LOOK TO ONLY FALL BACK
TO AROUND THE AVERAGE HIGHS FOR THIS TIME OF YEAR. BY THE TIME
JANUARY IS ALL SAID AND DONE...SHOULD HAVE AN AVERAGE TEMPERATURE
DEPARTURE AT MSP SOMEWHERE IN THE NEIGHBORHOOD OF 8 DEGREES...WITH
JANUARY OF 2012 POSSIBLY REPLACING JANUARY OF 1933 AS 8TH WARMEST
ALL TIME /23.1 WAS THE AVE TEMP FOR JAN OF 1933/.
ONLY OTHER CHANCE FOR PRECIP LOOKS TO COME LATE MONDAY NIGHT INTO
TUESDAY AS A SFC LOW TRACKS ACROSS NRN MN. UNFORTUNATELY...THIS
LOW AND ITS ASSOCIATED COLD FRONT WILL BE ENCOUNTERING QUITE A BIT
OF DRY AIR OVER THE MPX CWA...WITH BEST PRECIP SIGNAL BEING UP
ACROSS NRN MN. STILL...SLIGHT SOUTHWARD SHIFT IN MODELS THIS
MORNING PROMPTED AN INTRODUCTION FOR SOME SLIGHT CHANCE POPS
ACROSS FAR NRN CWA LATE MONDAY NIGHT THAT LAST THROUGH THE DAY ON
TUESDAY. AN PRECIP AMOUNTS LOOK LIGHT...WITH P-TYPE BEING A RA/SN
MIX INTO TUESDAY MORNING THAT TRANSITIONS TO MAINLY RA DURING THE
DAY.
AS WE END THE WEEK...THE BIG STORY HERE WILL BE THE SIGNIFICANT
PATTERN SHIFT THE MEDIUM RANGE MODELS ARE SHOWING GOING INTO THE
WEEKEND. OUR CURRENT FAST WNW FLOW LOOKS TO BECOME MORE AMPLIFIED
BY THE WEEKEND...WITH A STRONG UPPER RIDGE DEVELOPING OVER WRN
NOAM AND THE PATTERN RESEMBLING MORE A LA NINA SITUATION FOR
ONCE. THOUGH THIS DOES OPEN US UP TO N/NW FLOW THIS WEEKEND...THE
ASSOCIATED COOL DOWN LOOKS TO ONLY TAKE ABOUT 10 DEGREES OFF OF
HIGHS...WITH READINGS GOING FROM 15 TO 20 DEGREES ABOVE NORMAL BACK
DOWN TO 5 TO 10 DEGREES ABOVE NORMAL. THERE ARE NO INDICATIONS OF
SIGNIFICANT COLD AIR SHOWING UP UNTIL THE SECOND WEEK OF
FEB...WHEN BOTH THE GFS/ECMWF SHOW A POLAR VORTEX SHOWING UP OVER
SRN HUDSON BAY. EVEN THEN THOUGH...MN LOOKS TO BE ON THE BOUNDARY
BETWEEN THE ARCTIC AIR TO THE EAST AND THE MILD PACIFIC AIR TO THE
WEST.
&&
.AVIATION.../18Z TAF ISSUANCE/
SHORT TERM CONCERNS... OR THRU 00Z DEPENDS UPON MVFR CLDS ACROSS
SW MN...AND IF THEY CONTINUE TO DEVELOP ACROSS SW...INTO SC MN
THIS AFTN WHICH WOULD BRING SOME MVFR CIGS TO RWF...AND POSSIBLY
AS FAR EAST AT MSP. AFT 00Z...AVIATION CONCERNS SHIFT TO THE WARM
FRONT MOVING ACROSS THE DAKOTAS THIS MORNING...AND HOW
PRECIPITATION SPREADS EASTWARD AND HOW LOW CIGS/VSBYS BECOME AS
LOW LEVELS SATURATE THIS EVENING.
TIMING OF THE -SN REMAINS CLOSE TO PREVIOUS TAFS WITH AXN ARND
00-01Z...WITH THE HEAVIEST BETWEEN 2-6Z. CIGS WILL TEMPO LOWER TO
LOW END MVFR WITH VSBYS ARND 1-2SM. RWF WILL LIKELY BE ON THE EDGE
OF THE SATURATED DENDRITIC ZONE WHICH WILL KEEP ANY TYPE OF VSBY
RESTRICTIONS TO A MINIMUM. CIGS COULD BRIEF LOWER TO MVFR IF
HEAVIER SN DEVELOPS. STC WILL BE SIMILAR TO AXN WITH TIMING OFF BY
1-2 HRS. RNH/EAU WILL LIKELY NOT SEE ANY TYPE OF RESTRICTIONS TO
VSBY UNTIL AFT 6Z WHICH WILL ALLOW FOR ONE MORE TAF PERIOD BEFORE
ANY TYPE OF SIGNIFICANT CHGS. WNDS WILL SHIFT TO THE SW/S THIS
AFTN FROM WEST TO EAST...WITH S/SE THIS EVENING WITH GUSTS OF 18
TO 22 KTS IN THE TYPICAL AREAS OF RWF/AXN/STC. WNDS SHOULD BECOME
TO DECREASE AFT MIDNIGHT...WITH MORE SW WNDS BY 12Z.
MSP...AS PREVIOUSLY STATED...MVFR CIGS ASSOCIATED WITH MOISTURE
ACROSS SW MN WILL BE LIMITED AS IT MOVES TO THE NE AS WNDS SHIFT
TO THE SW THIS AFTN. WILL ONLY ADVERTISE FEW025 ATTM BASED ON
CURRENT SATELLITE TRENDS. TIMING WHEN -SN STARTS IS SIMILAR TO
PREVIOUS TAFS...WITH THE HEAVIEST ACTIVITY LIKELY BETWEEN 4-7Z.
CIGS/VSBYS WILL LOWER AS -SN DEVELOPS. DENDRITIC ZONE WHERE THE
BEST LIFT OCCURS WILL BE BRIEF...AND WILL LIKELY END ABRUPTLY AFT
6Z. HOWEVER...THERE REMAINS SOME LIFT AFT 6Z WITH PRECIPITATION
TYPE A CONCERN. WILL INTRODUCE PL AT THIS TIME...BUT IT COULD BE
MORE -FZDZ/-FZRA DUE TO THE DEPTH OF THE WARM LAYER MOVING IN
RAPIDLY THIS EVENING. AFT 12-15Z/30...VFR CONDITIONS SHOULD
PREVAIL WITH WNDS BECOMING MORE S/SW UNDER 8 KTS.
.TUE...VFR.
.WED...MVFR/PRECIPITATION POSSIBLE.
.THU...VFR.
..JLT..
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
MPG/JLT
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
321 PM CST SUN JAN 29 2012
.DISCUSSION...
Short Term (Tonight through Tuesday Night)...
Near record warmth and fire weather concerns Monday remain the short
term weather highlights.
Recent satellite imagery shows the bulk of mid-high cloud cover
already beginning to shift north as upper flow begins to flatten
under the influence of weak upstream ridging. More prevalent
sunshine has allowed temperatures to reach the 50 degree mark yet
again, with the exception of far northeast Missouri where light snow
cover has kept readings in the upper 30s.
A dramatic increase in lower tropospheric temperatures will continue
through tonight as westerly winds spread across the Plains. With
cloud cover now expected to be a non-issue on Monday, the potential
for near-record highs looks much more certain. Have nudged up maxes
another degree or two, and given 925mb temp progs would not be
surprised to see a few isolated upper 60s given the favored
southwest surface winds. The record of 68 at Kansas City is one of
the longest standing records left (set in 1890) to this would be
quite a feat.
Dewpoint forecast remains the most challenging, with models having
grossly overforecast dewpoints on day 1 of nearly every warm spell
this season. Current surface analysis shows 30F+ dewpoints
restricted to Deep South Texas, with offshore or shore-parallel flow
prevailing across the western Gulf. Simply put, with -10 to -20C
dewpoints atop the boundary layer, models are simply off their
rockers with upper 30s to lower 40F dewpoints advecting into the
area tomorrow, especially given the continental wind
vectors...nevermind vertical mixing. Have made dramatic cuts to
dewpoints tomorrow with modified Gulf return not anticipated until
later Monday night. Given ambient conditions and mixing potential,
these cuts may still not be enough, and thus the potential for RH
values to plummet to near 20%. Therefore, went ahead with a fire
weather watch for tomorrow afternoon for all but northeast Missouri.
Should my hunch be correct, would expect a red flag warning to be
posted tonight.
Otherwise, moisture will begin to surge into the area ahead of a
weak front later Monday night, accompanied by a rapidly broadening
expanse of stratus. Low clouds, drizzle and fog will likely restrict
warming into the day Tuesday, and the current forecast looked
reasonable in these aspects. Clearing should take place from the
northwest Tuesday night, but with high pressure spilling off the
Colorado Rockies and a weak pressure gradient, the cool down will be
modest at best.
Bookbinder
Medium Range (Wednesday - Sunday):
Confidence in regards to the extended forecast remains low as models
are still struggling with the timing/location/intensity of a pattern
change from quasi-zonal to very meridional flow. There is general
agreement that a ridge will begin to build across the eastern
Pacific later this week and spread eastward into the western CONUS
Thursday into Friday. The response to this ridging is for troughing
to develop across the eastern half to two-thirds of the CONUS. And
this is where models are struggling, both run to run and amongst
themselves and their ensembles. By Friday, ensemble standard
deviation really increases across the region with values approaching
10 decameters and there could be a closed low anywhere from roughly
the Four Corners area to the Great Lakes. Given the huge uncertainty
for this period did not deviate much from the forecast
initialization. One minor change was to reduce precipitation chances
as confidence is just not high enough to justify mentioning a chance
of anything at this time. Also, even though there is poor agreement
regarding the details of the Eastern CONUS troughing there is
general agreement that the area should remain in or be close to the
cyclonic flow aloft which favors a cooling trend and we should be
more likely to see temperatures closer to normal heading into the
weekend.
CDB
&&
.CLIMATE...
Record high temperatures for January 30:
Kansas City...68 set in 1890
St. Joseph....64 set in 1988
&&
.AVIATION...
Blanket of mid cloud cover not handled well by all but the RUC model
has continued to spread southeast, topped by additional
cirro-stratus further upstream. Broken cloud cover should persist
through early evening, affecting mainly MCI/STJ with an overall
dissipating trend as the moisture is gradually shunted north and
east between 10-25kft.
Otherwise, light/variable flow will continue this afternoon, with a
trend toward light southeast and then south winds overnight. Winds
should finally settle around to the southwest before daybreak with
an increase in speed to 10-12 knots by mid morning.
In concert with strong warm advection tonight, better flow develops
aloft after midnight, but the vertical shear progs and degree of
boundary layer mixing later tonight lead me to believe that low
level wind shear will not be a major concern at this time. Certainly
if the near surface winds do not return as expected, then LLWS may
need to be included for the 00Z TAFs.
Bookbinder
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...FIRE WEATHER WATCH MONDAY AFTERNOON FOR MOZ001>005-011>015-
020>023-028>031-037>039-043>046-053-054.
KS...FIRE WEATHER WATCH MONDAY AFTERNOON FOR KSZ025-057-060-102>105.
&&
$$
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1121 AM CST SUN JAN 29 2012
...UPDATED AVIATION...
.DISCUSSION...
Water vapor imagery shows a subtle short wave tracking across the
Upper Midwest early this morning. Any appreciable moisture and
associated chances for light snow will stay to the northeast of the
forecast area with only a few mid/high clouds expected across
northern and central Missouri. As this system tracks into the Great
Lakes later this morning, veering low level winds behind it will
result in weak cold air advection across much of the forecast area
through at least 18Z. As a result, nudged max temperatures down a
degree or two for today, though they will still be well above
average, especially across the western CWA.
Warm air advection will get underway tonight as a broad upper ridge
spreads into the Plains. Resulting downslope westerly low-level flow
will spread much-above average temperatures into the region on
Monday, with 925 hPa temperatures forecast to be over 2 standard
deviations above average. These temperatures will be further boosted
by weak confluent/compressional low-level trajectories and a
favorable environment for boundary layer mixing. As a result, near-
record highs in the lower to middle 60s appear in store for the
western half of the forecast area (reference climate section below).
Utilized biased-corrected versions of the NAM/MET/ECMWF which appear
to handle forecast temperatures well, especially if the BL mixes a
bit higher than indicated by NAM forecast soundings.
A weak front will drop into the area on Tuesday with slightly
"cooler" temperatures in the upper 50s to near 60. Will need to watch
for potential low stratus and even a few rain showers developing
early Tuesday particularly across the eastern CWA in a region of
strong low-level moisture transport. However, with warm skin
temperatures and strongly veered low-level flow, would expect stratus
to struggle to develop and if it does, it should quickly scatter out
by afternoon.
Forecast confidence then deteriorates rapidly beyond 84 hours as
a highly meridional ridge begins to build into the West Coast with
downstream mean troughing across the eastern 2/3 of North America.
Subtle yet hard-to-resolve features developing downstream of the
upper ridge are plaguing medium range models with high run-to-run
variability. At some point a developing southwest system will likely
kick out into the Plains in the Weds night to early Friday time
frame. For now, made little deviation from model consensus PoPs
keeping the highest likelihood for precip across the south Thursday
evening. Despite the eventual outcome, large scale patterns support
northerly flow and temperatures returning closer to average by the
end of the extended.
Hawblitzel
&&
.CLIMATE...
Record high temperatures for January 30:
Kansas City...68 set in 1890
St. Joseph....64 set in 1988
&&
.AVIATION...
Blanket of mid cloud cover not handled well by all but the RUC model
has continued to spread southeast, topped by additional
cirro-stratus further upstream. This cloud cover should persist
through early evening before shifting north and east as the upper
ridge builds in.
Otherwise, light/variable flow will continue this afternoon, with a
trend toward light southeast and then south overnight, ultimately
becoming southwest before daybreak with an increase in speed to
10-12 knots by mid morning.
Better flow develops aloft overnight as strong warm advection
ensues, but the vertical shear progs and degree of boundary layer
mixing later tonight don`t lead me to believe that low level wind
shear will not be a major concern at this time. Certainly if the
near surface winds do not return as expected, then LLWS may need to
be included for the 00Z TAFs.
Bookbinder
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION
NWS GLASGOW MT
1005 AM MST SUN JAN 29 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY...
STRONG...BUT DRY WARM FRONT PUSHING E ACROSS OUR AREA THIS
MORNING...WITH TEMPS IN THE 20S AND LOWER 30S ON ONE SIDE AT 9
AM...40S AND LOWER 50S ON THE OTHER SIDE. THE WARMER AIR TO SPREAD
ACROSS THE ENTIRE CWA DURING THE REST OF THE LATE MORNING AND
AFTERNOON.
NO PRECIP REPORTED WITH THE FRONT...ALTHOUGH 88D RADAR RETURNS
INDICATING PROBABLY A FEW SNOWFLAKES AND SPRINKLES...MAINLY IN
OUR E. ALL MODELS TOO MOIST WITH THIS SYSTEM. THERE WILL BE A WEAK
SHORTWAVE FROM THE WNW THIS AFTERNOON...BUT EXPECTING MAINLY
JUST SPRINKLES IN THE WARMER AIRMASS. 850 MB TEMPS AS HIGH AS 10C
IN OUR SW TODAY.
HIGH WIND WARNING FOR SW PHILLIPS COUNTY VERIFIED WITH 70 MPH GUST
AT MALTA DOT. THE RESPONSIBLE 50-60 KT WINDS AT 850 MB MOVES
ACROSS OUR ENTIRE CWA TODAY. MODEL FORECAST SOUNDINGS SHOW
PROFILES NOT FAVORABLE TO MIX THESE SPEEDS TO SURFACE...HOWEVER
THE SOUNDINGS DO LOOK QUITE CLOSE FOR PARTS OF PETROLEUM...S
PHILLIPS AND W GARFIELD COUNTIES. UPDATE MADE EARLIER...NO FURTHER
UPDATE NEEDED. SIMONSEN
PREVIOUS SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH
TUESDAY...WATER VAPOR IMAGERY AND 500 MB HEIGHT FIELD SHOWING A
BROAD TWO- THEMED WEATHER PATTERN ACROSS THE CONUS. THE HUDSON BAY
UPPER LOW CONTINUES TO PINWHEEL A FEW SMALLER SCALE SHORT WAVE
TROUGHS THROUGH THE GREAT LAKES AND NORTHEASTERN CONUS REGIONS.
GENERAL BROAD SCALE UPPER LEVEL TROUGHING IS IN PLACE OVER THE
REMAINDER OF THE EASTERN CONUS. A WEAK UPPER LEVEL RIDGE OVER THE
SOUTHWESTERN CONUS REGION CONTINUES TO WEAKEN UNDER A
STRENGTHENING STORM SYSTEM NOW MOVING ON SHORE OVER THE PACIFIC
NORTHWEST AND QUICKLY MOVING EASTWARD THROUGH THE NORTHERN ROCKIES
REGION. A FEW VERY SMALL SCALE SHORT WAVE TROUGHS ARE SETTING OFF
SOME THUNDERSTORMS EARLY THIS MORNING OVER THE OLYMPIC PENINSULA
OF WASHINGTON STATE.
PLENTIFUL MOISTURE IS STREAMING ALONG AND OVER THE CONTINENTAL
DIVIDE...MAKING ITS WAY OVER NORTHEAST MONTANA THIS MORNING. AN
AREA OF STRATIFORM SNOW FALL HAS SPREAD ACROSS THE CWA OVERNIGHT
AND THROUGH THE EARLY MORNING HOURS WITH JUST A FEW HIGHER
EMBEDDED AREAS OF MODERATE SNOW WHICH LASTED ONLY FOR SUDDEN
SPURTS. LOOKS LIKE THE NAM WAS MORE CORRECT IN THE PRECIP
PLACEMENT BUT A LITTLE TOO BULLISH ON THE PRECIP AMOUNTS.
FORECAST CHALLENGES INVOLVE THE PROGRESSION OF THIS STORM SYSTEM AS IT
MOVES ACROSS NORTHEAST MONTANA...INCLUDING THE EXTENT OF SNOW FALL
OVER OUR EASTERN ZONES...THE TRANSITION FROM SNOW TO A RAIN AND
SNOW MIX TO RAIN THROUGHOUT THE DAY TODAY FROM SOUTHWEST TO
NORTHEAST...AND THE HIGH WINDS OVER THE LITTLE ROCKIES AND HIGHWAY
191 TODAY.
THE INITIAL PUSH OF SNOWFALL ACROSS NORTHEAST MONTANA HAS ALREADY
MADE ITS WAY ACROSS OUR CWA. ACCORDING TO THE LATEST HRRR MODEL
RUNS...THERE MAY BE ANOTHER PUSH OR BAND OF SNOWFALL SET TO MOVE
ACROSS THE CWA LATER THIS MORNING...BUT IT LOOKS TO AMOUNT TO NOT MUCH.
TEMPERATURES A LITTLE TRICKY THIS MORNING. WE MAY HAVE ALREADY
REACHED OUR MORNING LOWS DURING THE MIDNIGHT HOUR. SURFACE
OBSERVATION TRENDS SHOWING STEADILY INCREASING TEMPERATURES EARLY
THIS MORNING BEHIND THE WARM FRONT JUST WEST AND SOUTHWEST OF OUR
CWA BORDER. TRIED TO SHOW A NON-DIURNAL TEMPERATURE TREND THIS
MORNING TO REPRESENT THIS THINKING. AS THE FRONT PUSHES THROUGH
OUR CWA TODAY...SNOW WILL TRANSITION OVER TO A RAIN AND SNOW
MIX...THEN BECOME ALL RAIN THIS AFTERNOON AS TEMPERATURES QUICKLY
CLIMB TO WELL ABOVE NORMAL LEVELS FOR THIS TIME OF YEAR. EXPECT
THE RAIN AND SNOW MIX TO BE AN ISSUE ONLY FOR THE 6 HOUR PERIOD
TODAY BETWEEN EARLY MORNING AND MID DAY.
WESTERLY WINDS ALREADY EARLY THIS MORNING AT ZORTMAN MINE AND THE
DOT SITE SOUTH OF MALTA ARE GUSTING IN THE 40 TO 50 MPH RANGE. THE
HIGH WIND WARNING LOOKS TO BE WELL PLACED AND WELL TIMED. KEEP AN
EYE ON ADDITIONAL SURROUNDING AREAS OF HIGHER TERRAIN IN CASE A
STRAY HIGH WIND GUST MIXES DOWN TO THE SURFACE...SAY IN PETROLEUM
COUNTY.
TONIGHT...THE STORM SYSTEM MAKES A QUICK EXIT TO THE EAST AS AN
UPPER LEVEL SHORT WAVE RIDGE SUSTAINS THE WARM UP TODAY AND MONDAY
TO THE TUNE OF NEARLY 20 DEGREES ABOVE NORMAL FOR THIS TIME OF YEAR.
LATE MONDAY INTO EARLY TUESDAY...ANOTHER UPPER LEVEL DISTURBANCE
QUICKLY SLIDES OVER THE NORTHERN ROCKIES AND THROUGH NORTHEAST
MONTANA...BRINGING A SPOTTY AND DISORGANIZED CHANCE FOR RAIN AND
SNOW TO PORTIONS OF OUR CWA. BMICKELSON
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...
PATTERN TRANSITIONS FROM ACTIVE ZONAL FLOW TO A HIGH AMPLITUDE
RIDGE ACROSS THE WESTERN STATES DURING THE EARLY DAYS OF THE
EXTENDED PERIOD. MODELS INDICATE TWO SHORTWAVES SLIDING ACROSS
EASTERN MONTANA WITH REASONABLE AGREEMENT ON TIMING. THE FIRST
WAVE CROSSES NORTHEAST MONTANA TUESDAY NIGHT BUT IS VERY WEAK WITH
NOT MUCH MOISTURE SO EXPECT DRY CONDITIONS. SECOND WAVE FOLLOWS
CLOSE BEHIND ON WEDNESDAY/WEDNESDAY NIGHT. THIS WAVE IS STRONGER
WITH BETTER DYNAMICS AND MOISTURE BUT MODELS STILL SUGGESTING BEST
CHANCES FOR PRECIPITATION WILL BE ACROSS SOUTHWEST MONTANA WITH
UPPER FLOW VEERING AS RIDGE BUILDS TO THE WEST. WILL KEEP WITH
CONSENSUS FOR NOW AND STAY WITH DRY FORECAST.
RIDGE BEGINS TO DOMINATE THE NORTHERN ROCKIES BY THURSDAY WITH
WARM AIR PUSHING EAST OF THE DIVIDE. BY THE WEEKEND THE WARM AIR
WILL BE FIRMLY IN PLACE OVER MONTANA...ALTHOUGH WITH LITTLE WIND
MIXING WILL BE DIFFICULT. EBERT
&&
.AVIATION...
VFR. A BAND OF LIGHT SNOW MAY BRIEFLY AFFECT GLENDIVE AND SIDNEY
THIS MORNING...OTHERWISE MID AND HIGH CLOUDS ARE EXPECTED TO STICK
AROUND TODAY. SOME LOW LEVEL WIND SHEAR IS POSSIBLE AS LIGHT WINDS
AT THE SURFACE INCREASE DRAMATICALLY OFF THE GROUND ESPECIALLY
FROM GLASGOW TO MILES CITY CORRIDOR TODAY. MID LEVEL WINDS SHOULD
DIMINISH TONIGHT. JAMBA
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 5 PM MST THIS AFTERNOON FOR SOUTHWEST
PHILLIPS.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS BUFFALO NY
353 PM EST SUN JAN 29 2012
.SYNOPSIS...
A FAST MOVING WAVE OF LOW PRESSURE WILL MOVE ACROSS THE REGION
THROUGH THIS EVENING...BRINGING A BRIEF PERIOD OF HEAVY SNOW TO MOST
LOCATIONS. THIS WILL BE FOLLOWED BY LAKE SNOWS EAST OF THE LAKES
TONIGHT AS A WESTERLY FLOW OF BRIEFLY COLDER AIR SPREADS ACROSS THE
LOWER LAKES. AN APPROACHING WARM FRONT WILL THEN BRING ANOTHER ROUND
OF WIDESPREAD LIGHT SNOW TO THE AREA LATE MONDAY AND MONDAY NIGHT...
FOLLOWED BY A SIGNIFICANT WARMUP FOR TUESDAY AND ESPECIALLY
WEDNESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
FOR THE REMAINDER OF THIS AFTERNOON...LAKE SNOWS WILL LINGER EAST OF
LAKE ONTARIO. IR SHOWS LEFT OVER MOISTURE FROM THIS MORNINGS ROUND
OF SNOWS OF LAKE ERIE. THIS MOISTURE IS NOW MOVING ACROSS WHAT WAS A
WEAK LAKE EFFECT BAND...AND ENHANCING IT. EXPECT COUPLE HOURS OF
FAIRLY WIDESPREAD SNOWS...WITH LOCALLY HEAVY SNOWFALL ALONG A LAKE
CONVERGENCE BAND EXTENDING FROM NEAR WATER TOWN TO FORT DRUM. THIS
ALL SHOULD DIMINISH IN INTENSITY LATE AFTERNOON...BRIEFLY...BEFORE
THE NEXT SYSTEM COMES EARLY THIS EVENING.
A QUITE VIGOROUS SHORTWAVE AN WEAK SURFACE REFLECTION WILL QUICKLY
MOVE ACROSS THE REGION THROUGH THIS EVENING. THIS WILL CAUSE TWO
PERIODS OF SNOW...ONE WITH THE SHORTWAVE...AND THEN ANOTHER IN LAKE
EFFECT BEHIND HIT.
THROUGH THIS EVENING (THE SHORTWAVE)...A QUITE DISTINCT VORT MAX
EMBEDDED IN A CYCLONIC 500 MB TROF WILL CROSS THE REGION BETWEEN 500
PM AND 1000 PM. THIS SHORTWAVE IS PRODUCING AMPLE LIFT IN ITS OWN
RIGHT...WITH FAIRLY WIDESPREAD 1/4SM TO 1/2SM VSBY IN MODERATE TO
HEAVY SNOW ACROSS SOUTHEASTERN MICHIGAN. IF ANYTHING...SNOWFALL
SHOULD BE ENHANCED BY LAKE MOISTURE AND MODEST AMOUNTS OF LAKE
INDUCED INSTABILITY AHEAD OF THE BOUNDARY. THE SHORTWAVE WILL COOL
TEMPERATURES ALOFT...WITH EQUILIBRIUM LEVELS RISING TO NEAR 20K
FEET. MID LEVEL LAPSE RATES DROP TO AROUND 8 C/KM ALOFT. THIS ALL
INCREASES CONFIDENCE IN A TWO OR THREE HOUR PERIOD OF QUITE INTENSE
SNOWFALL ACROSS MUCH OF THE CWA. AS ONE MIGHT EXPECT...THIS RESULTS
IN A PERIOD OF VERY GOOD SNOW GROWTH...WITH A NEARLY CLASSIC
SIGNATURE OF BEST LIFT ALIGNED WITH -12C TO -20C TEMPERATURES ALOFT.
WHILE THE BRIEF NATURE OF THE EVENT WILL LIMIT SNOWFALL
TOTALS...EXPECT IT WILL HAVE A SIGNIFICANT IMPACT DURING THAT TIME.
FOR THIS REASON...WILL GO WITH A WINTER WEATHER ADVISORY ACROSS MOST
OF THE CWA. GENERALLY SPEAKING...THIS FEATURE SHOULD BRING A QUICK 2
TO 4 INCHES OF SNOW THROUGH THIS EVENING. AMOUNTS WILL TAPER OFF
FURTHER SOUTH AND EAST...AND FOR NOW WILL KEEP
ALLEGHENY/LIVINGSTON/ONTARIO COUNTIES OUT OF THE ADVISORY...AS THE
LACK OF LAKE ENHANCEMENT SHOULD LIMIT SNOWS TO AROUND 2 INCHES.
FINALLY...ITS WORTH NOTING THAT A BRIEF PERIOD OF GUSTY WINDS IS
LIKELY IMMEDIATELY BEHIND THE LOW...WHICH MAY CAUSE AREAS OF BLOWING
AND DRIFTING SNOW.
AFTER MIDNIGHT (LAKE EFFECT) WHILE THE LOW WILL QUICKLY EXIT EAST
LATE THIS EVENING...THERE WILL BE A SECOND ROUND OF LAKE SNOWS ON
THE BACK OF THE SYSTEM. WINDS WILL SHIFT TO THE WNW BEHIND THE
SYSTEM. OFF LAKE ERIE...EXPECT AMOUNTS TO BE MODEST...WITH A CAP AT
AROUND 7000 FT...AND A LIMITED FETCH OFF THE LAKE. HERE...BEST SNOWS
SHOULD COME LATE EVENING INTO THE EARLY MORNING HOURS...WHEN
MOISTURE LINGERS BEHIND THE EXITING SHORTWAVE. OFF LAKE
ONTARIO...CONSENSUS WIND FORECASTS POINT TO THE BEST LAKE SNOWS
ACROSS OSWEGO COUNTY...AND IN NORTHERN PORTIONS OF WAYNE AND CAYUGA
COUNTIES. HERE...THE CAP WILL BE MORE LIKE 9000 FT...WITH A LONGER
FETCH OFF THE LAKE. THE BAND MAY BRIEFLY DISRUPT DURING THE EARLY
MORNING HOURS...BUT WINDS ARE AT A NEARLY IDEAL SPEED...AND THEY
BECOME BETTER ALIGNED TOWARD DAYBREAK. ALL THIS POINTS TO A QUITE
INTENSE LAKE EFFECT BAND TO DEVELOP AT THIS TIME...WITH SNOWFALL
RATES TO 2 INCHES PER HOUR POSSIBLE. THIS SHOULD BE FAIRLY SHORT
LIVED...AS WINDS BECOME MORE SHEARED ON MONDAY MORNING...BUT THIS
AREA DOES BEAR WATCHING FOR A POSSIBLE UPGRADE TO WARNING.
FINALLY...THERE IS THE ISSUE OF THE LAKE ONTARIO SOUTH SHORES FROM
NIAGARA COUNTY TO MONROE COUNTY. IT IS POSSIBLE A BAND WILL MEANDER
ONSHORE THERE FROM TIME TO TIME...ESPECIALLY DURING THE LAKE EVENING
HOURS. THIS BEARS WATCHING...BUT FOR NOW WILL FOCUS THE ADVISORY IN
THESE COUNTIES ON THE SHORTWAVE...AND NOT THE LAKE EFFECT AFTERWARD.
AS HAS BEEN THE CASE FOR THE PAST SEVERAL DAYS...THE BREAK BETWEEN
SYSTEMS WILL BE BRIEF. ACTUALLY...SNOWS FROM THE NEXT SYSTEM MAY
START BEFORE THE LAKE EFFECT ON EASTERN LAKE ONTARIO IS COMPLETELY
DONE. HOWEVER...THIS SYSTEM WILL BE VERY DIFFERENT FROM THE LAST.
SNOW WILL BE CAUSED BY MORE OF A BROAD AREA OF MID-LEVEL WARM AIR
ADVECTION. THIS SHOULD RESULT IN A MORE GENERAL SNOWFALL...MUCH LESS
INTENSE THAN EARLIER SYSTEMS. EXPECT AROUND AN INCH OF ACCUMULATION
FROM THIS ACROSS FAR WESTERN NEW YORK FROM THIS THROUGH SUNSET.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
THE AXIS OF HIGH PRESSURE WILL BE WELL EAST OF THE FORECAST AREA
MONDAY NIGHT WITH AS STRONG WARM ADVECTION PATTERN DEVELOPING.
BOUNDARY LAYER TEMPS WILL REMAIN BELOW FREEZING EARLY ON AS THE
ELEVATED WARM FRONT CROSSES THE REGION WITH A BAND OF ASSOCIATED
LIGHT SNOW. USE OF THE WARM LAYER ALOFT PRECIP TYPE TOOL INDICATES
THAT THERE MAY BE SOME MIXED WINTRY PRECIP ALONG THE TRAILING EDGE
OF THE SNOW...ALTHOUGH THE VERTICAL MOISTURE PROFILE IS RATHER
NARROW AND MAY OUTRUN THE WARMING LEADING TO A DRIER PROFILE BY THE
TIME THAT THE WARM AIR ALOFT ARRIVES. WILL SHOW CHANCE POPS FOR
LIGHT MIX OF FREEZING RAIN AND SLEET BETWEEN MIDNIGHT AND DAYBREAK
ON TUESDAY...AND SHORT LIVED FOR ANY ONE AREA AS THIS TRAILING EDGE
OR PRECIP LIFTS THROUGH.
TUESDAY WILL BE CHARACTERIZED BY WARMER TEMPS AND BREEZY SOUTH TO
SOUTHWEST WINDS...TEMPS RISING TO THE MID TO UPPER 40S FOR MOST
LOCALES...AND IN THE MID 30S TO AROUND 40 FOR THE EASTERN LAKE
ONTARIO REGION. THE PRECIP WILL HAVE BEEN SHUNTED TO THE NORTH AND
THERE WILL REMAIN A CHANCE OF LIGHT RAIN OR A MIX OF RAIN AND WET
SNOW...BUT EXPECT IT TO BE DRY FOR THE REST OF THE REGION.
LOW PRESSURE MOVING NEAR WEST TO EAST ACROSS THE CENTRAL GREAT LAKES
AND TO THE NORTH OF LAKE ONTARIO WILL BRING A COLD FRONT TO THE WEST
OF THE REGION TUESDAY NIGHT...THE WARM SECTOR REMAINING IN PLACE
THROUGH THE NIGHT. WILL SEE LEFT FRONT EXIT REGION OF UPPER JET
ENHANCING PRECIP AHEAD OF THE COLD FRONT WITH LIKELY POPS FOR LIGHT
RAIN DURING THE NIGHT. THE TEMPS WILL ALSO REMAIN ON THE WARM SIDE
WITH OVERNIGHT LOWS NOT FALLING BELOW 40 DEGREES FOR MUCH OF THE
FORECAST AREA...SOME MIDDLE TO LOWER 30S FOR THE NORTH COUNTRY AND
THAT WILL BE EARLY IN THE EVENING WITH TEMPS RISING OVERNIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE SURFACE COLD FRONT TRAILING THE LOW TO OUR NORTH WILL CROSS THE
REGION WEDNESDAY MORNING WITH VERY MILD MORNING TEMPS GIVING WAY TO
FALLING TEMPS DURING AFTERNOON. BEST RAIN CHANCES WILL BE
EARLY...WITH DRYING EXPECTED BY AFTERNOON IF THE CURRENT MODEL
TIMING HOLDS.
COLD ADVECTION BEHIND THE SYSTEM WILL BRING TEMPS DOWN...BUT STILL
ABOVE CLIMO FOR THURSDAY WITH A FEW LIGHT SNOW SHOWERS POSSIBLE EAST
OF THE LAKES.
THURSDAY NIGHT INTO NEXT WEEKEND BECOME MORE UNCERTAIN WITH THE
LATEST GFS AND ECMWF RAPIDLY BECOMING DRAMATICALLY DIFFERENT IN THE
SYNOPTIC DETAILS AND EVEN THE LARGE SCALE PATTERN. THE GFS IS MUCH
LESS AMPLIFIED WITH A FLAT TROUGH ON THURSDAY NIGHT WITH A DIGGING
TROUGH SHOWING STRONGER AMPLIFICATION ON SATURDAY. THE ECMWF IS MORE
AMPLIFIED EVEN ON THE FAST MOVING SHORT WAVES THURSDAY THROUGH
FRIDAY...AND DEPICTS A DEEP AMPLITUDE 500MB TROUGH IN THE LEE OF THE
ROCKIES ON FRIDAY MORNING...TRYING TO BECOME A CUTOFF LOW ON
SATURDAY...THEN A POSITIVELY TILTED AND DEEP AMPLITUDE WAVE ON
SUNDAY.
GIVEN THE LACK OF MODEL CONSISTENCY...WILL STICK CLOSE TO THE
CONTINUITY FORECAST FOR LATE IN THE WEEK INTO NEXT WEEKEND...WITH A
CLIPPER PASSING TO THE WEST AND SOUTH OF US ON FRIDAY NIGHT AND
SATURDAY BRINGING SOME SNOW SHOWERS AND FLURRIES TO THE FORECAST
AREA. THE COMPLEXITY OF THE PATTERN EVOLUTION LATE NEXT WEEK WILL
LIKELY RESULT IN ONGOING MODEL UNCERTAINTY FOR SEVERAL MORE DAYS
UNTIL MODELS BEGIN TO CONVERGE ON A COMMON SOLUTION.
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
FOR THE 21Z TAFS...A SIGNIFICANT SHORTWAVE WILL MOVE ACROSS THE
REGION. BASED ON UPSTREAM OBSERVATIONS...AND NUMERICAL
GUIDANCE...HAVE AMPLE CONFIDENCE TO CARRY A PERIOD OF HEAVY SNOW
WITH 1/4SM VSBY AT MOST TAF SITES. TIMING BASED ON A COMBINATION
OF THE HRRR MODEL AND RADAR TRENDS.
CONDITIONS WILL IMPROVE WITH THE EXIT OF THIS SYSTEM...WITH MAINLY
MVFR CONDITIONS OVERNIGHT. THE EXCEPTION WILL BE IN LAKE EFFECT
BANDS...BUT IN THE WNW FLOW THESE TYPICALLY HAVE ONLY MINOR
IMPACTS ON TAF SITES...THOUGH LOCAL AND BRIEF PERIODS OF LOWER
CONDITIONS ARE POSSIBLE.
OUTLOOK...
MONDAY NIGHT...IFR WITH LIGHT SNOW LIKELY.
TUESDAY...IFR WITH LIGHT SNOW LIKELY EAST OF LAKE ONTARIO...
ELSEWHERE IMPROVING TO MAINLY VFR.
WEDNESDAY...VFR/MVFR WITH A CHANCE OF RAIN SHOWERS.
THURSDAY...VFR/MVFR WITH A CHANCE OF SNOW SHOWERS.
FRIDAY...VFR.
&&
.MARINE...
MODERATELY STRONG SOUTHWESTERLIES AND WESTERLIES WILL CONTINUE
ACROSS THE LOWER LAKES REGION RIGHT INTO MONDAY. THIS WILL RESULT
IN CONDITIONS REMAINING SOLIDLY IN THE SMALL CRAFT ADVISORY RANGE
THROUGH MONDAY MORNING...BEFORE AN APPROACHING WARM FRONT RESULTS
IN DIMINISHING WINDS MONDAY AFTERNOON AND EVENING.
LOW PRESSURE PASSING TO THE NORTH ON WEDNESDAY WILL CAUSE
SOUTHWESTERLY WINDS TO INCREASE. WINDS MAY APPROACH GALES FOR A
PERIOD.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NYZ007-
008.
WINTER WEATHER ADVISORY UNTIL NOON EST MONDAY FOR NYZ004>006.
WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ001>003-010-011.
WINTER WEATHER ADVISORY UNTIL 4 AM EST MONDAY FOR NYZ012-019-
020-085.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST MONDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 4 PM EST MONDAY FOR
LOZ042>045.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...WCH
LONG TERM...WCH
AVIATION...APFFEL
MARINE...APFFEL
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1235 PM EST SUN JAN 29 2012
.SYNOPSIS...
A FAST MOVING WAVE OF LOW PRESSURE WILL CROSS THE REGION LATE
AFTERNOON THROUGH THIS EVENING...BRINGING A BRIEF PERIOD OF HEAVY
SNOW TO MOST LOCATIONS. THIS WILL BE FOLLOWED BY LAKE SNOWS EAST
OF THE LAKES TONIGHT AS A WESTERLY FLOW OF BRIEFLY COLDER AIR
SPREADS ACROSS THE LOWER LAKES. AN APPROACHING WARM FRONT WILL
THEN BRING ANOTHER ROUND OF WIDESPREAD LIGHT SNOW TO THE AREA LATE
MONDAY AND MONDAY NIGHT... FOLLOWED BY A SIGNIFICANT WARMUP FOR
TUESDAY AND ESPECIALLY WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE FOR WINTER WEATHER ADVISORIES. HAVE ISSUED WINTER WEATHER
ADVISORIES FOR MOST OF THE CWA...WITH THE GREATEST AMOUNTS EAST OF
LAKE ONTARIO...WHERE 4 TO 8 INCHES OF ADDITIONAL SNOWFALL IS
EXPECTED. LESSER AMOUNTS ELSEWHERE...TAPERING DOWN TO AN ADDITIONAL
2 TO 5 INCHES WEST OF ROCHESTER. BECAUSE A SIGNIFICANT SNOW BURST
IS EXPECTED...AND BECAUSE A COUPLE INCHES OF SNOW HAS ALREADY
FALLEN IN THIS AREA...HAVE OPTED TO HANDLE THIS WITH AN ADVISORY.
ALSO...BECAUSE THE EVENT IS BEING INFLUENCED BY BOTH SYNOPTIC AND
LAKE FACTORS...HAVE CARRIED A WINTER WEATHER ADVISORY FOR ALL TO
KEEP OUR MESSAGE SIMPLE. THE MAJORITY OF THE EVENT WILL BE
SYNOPTIC...WITH THE EXCEPTION OF OSWEGO/NORTHERN CAYUGA/WAYNE
COUNTIES...WHERE SIGNIFICANT LAKE SNOWS WILL LINGER LATE TONIGHT
INTO MONDAY.
AS OF NOON...RADAR SHOWS A BAND OF SNOW EXTENDING NORTH OF THE
BUFFALO AND ROCHESTER METRO AREAS. THIS BAND HAS CONTINUED TO
WEAKEN OVER THE PAST COUPLE HOURS...AND IT WILL CONTINUE TO WEAKEN
THROUGH EARLY AFTERNOON. MODELS HAVE NOT HANDLED THIS BAND WELL
AT ALL...WITH THE LIKELY CAUSE A COMBINATION OF MID- LEVEL WARM
AIR ADVECTION AND LAKE EFFECT ENHANCEMENT. EXPECT MOISTURE FROM
THIS BAND TO ADVECT ACROSS LAKE ONTARIO...WHICH WILL LIKELY ENHANCE
SNOWFALL EAST OF LAKE ONTARIO...DESPITE MODEL QPFS.
MODELS ARE CONSISTENT IN BRINGING A SHORTWAVE ACROSS THE REGION
LATE AFTERNOON. THE HRRR AND 12Z RUNS OF THE NAM12/RGEM/GFS BRING A
DECENT SNOW BURST LATE AFTERNOON INTO THIS EVENING. QPFS ARE
GENERALLY BETWEEN .10 AND .25 WITH THIS...WHICH IS MARGINAL FOR
ADVISORIES. HOWEVER...GIVEN THE POTENTIAL SNOWFALL RATES...AND THE
ANTICIPATED FLUFF FACTOR OF THE SNOW...OPTED TO GO WITH THE
ADVISORY.
IMMEDIATELY FOLLOWING THE DEPARTURE OF THE SURFACE WAVE THIS
EVENING...A WESTERLY TO WEST-NORTHWESTERLY FLOW OF COLDER AIR WILL
ONCE AGAIN SET UP ACROSS THE LOWER LAKES...WITH 850 MB TEMPS
DROPPING FROM AROUND -10C/-11C EARLY THIS EVENING TO AROUND -14C
BY MIDNIGHT. THIS WILL TRIGGER A RENEWED ROUND OF LAKE SNOWS EAST
/EAST-SOUTHEAST OF BOTH LAKES. OFF LAKE ERIE...THE RELATIVELY
SHALLOW MOISTURE FIELD AND LOW CAPPING INVERSION HEIGHT OF 5 KFT
SHOULD HELP KEEP THE LAKE SNOWS FAIRLY MINIMAL IN NATURE EAST OF
THE LAKE...WHERE ABOUT 1 TO 3 INCHES OF FRESH ACCUMULATION WILL BE
POSSIBLE THROUGH THE END OF THE NIGHT. OFF LAKE ONTARIO...THINGS
WILL BE A DIFFERENT STORY AS A MUCH DEEPER MOISTURE
FIELD...STRONGER LIFT...AND A CAPPING INVERSION OF AROUND 9-10 KFT
SHOULD ALLOW FOR ANOTHER ROUND OF ADVISORY-CRITERIA SNOWS. THE
MAIN QUESTION AT THIS POINT IS EXACTLY WHERE THESE WILL BE...AS
THE MODELS CONTINUE TO SHOW SOME VARIATION IN THE EXACT LOCATION
OF THE LAKE SNOW BAND...RANGING FROM THE 00Z NAM`S DEPICTION OF A
BAND EAST-SOUTHEAST OF THE LAKE...TO THE 00Z RGEM`S TUG HILL
POSITIONING.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
AT THE START OF THE PERIOD SOME LAKE EFFECT SNOW WILL PERSIST ON
MONDAY EAST OF THE LAKES WITH 850MB TEMPS BOTTOMING OUT AROUND -14C
DURING THE MORNING.
OFF LAKE ERIE...A SURFACE RIDGE WILL BUILD ACROSS THE LAKE DURING
THE MORNING AND DISRUPT/BACK THE LOW LEVEL FLOW AND ALSO DRY OUT THE
LOW LEVELS. THIS SHOULD BRING A QUICK END TO LAKE EFFECT WITH
LINGERING SCATTERED SNOW SHOWERS ACROSS THE WESTERN SOUTHERN TIER
LIFTING NORTH TOWARDS THE BUF SOUTHTOWNS AND FALLING APART WITH ONLY
VERY MINOR DUSTING TO AN INCH ACCUMULATIONS ON THE HILLS IN THE
EARLY MORNING.
OFF LAKE ONTARIO...CONDITIONS WILL STILL BE MORE FAVORABLE THROUGH
THE MORNING HOURS WITH LAKE INDUCED EQUILIBRIUM LEVELS AROUND 10K
FEET...DETERIORATING TO LESS THAN 7K FEET BY AFTERNOON AS THE
SURFACE RIDGE BUILDS ACROSS LAKE ONTARIO. THERE REMAINS SOME SPREAD
WITH BAND PLACEMENT IN THE LATEST 00Z MODEL SUITE WITH THE CANADIAN
GEM HOLDING THE LAKE EFFECT ACROSS NORTHERN OSWEGO COUNTY AND THE
SOUTHERN TUG HILL...WHILE THE NAM DROPS THE BAND INTO SOUTHERN
OSWEGO COUNTY AND EVEN CLIPS N.CAYUGA AND NE WAYNE COUNTY FOR
AWHILE. FOR NOW HAVE PLACED THE BAND ACROSS CENTRAL OSWEGO COUNTY
BUT THIS MAY NEED TO BE TWEAKED AS SHORT TERM MODEL GUIDANCE
CONVERGES ON A COMMON SOLUTION FOR BAND PLACEMENT. SYNOPTIC SCALE
MOISTURE IS DRYING OUT BY MONDAY MORNING...BUT MODERATE INSTABILITY
AND LONG FETCH SUGGEST THE POTENTIAL FOR SEVERAL MORE INCHES IN
PERSISTENT BANDS THROUGH THE FIRST HALF OF MONDAY. AN ADVISORY WILL
LIKELY BE NEEDED FOR THIS INTO MONDAY...BUT AS STATED IN THE NEAR
TERM DISCUSSION WE WILL WAIT UNTIL THE CURRENT ADVISORY EXPIRES
BEFORE RAISING A NEW ONE TO AVOID CONFUSION.
THE LAKE ONTARIO LAKE EFFECT WILL WEAKEN AND END MONDAY AFTERNOON AS
THE SURFACE RIDGE CROSSES THE LAKE AND DISRUPTS THE LOW LEVEL FLOW.
OUR ATTENTION THEN QUICKLY TURNS BACK TO THE SYNOPTIC SCALE. PAST
FEW RUNS OF THE GFS AND SREF HAVE BEEN CONSISTENT IN DEVELOPING AN
AREA OF LIGHT SNOW LATE MONDAY AFTERNOON ACROSS WESTERN NY...THEN
SPREADING EAST ACROSS THE REST OF THE AREA MONDAY NIGHT. THIS AREA
OF SNOW WILL BE SUPPORTED BY A MODERATE TO STRONG WARM ADVECTION
REGIME WITH AMPLE ISENTROPIC UPGLIDE AND MOISTURE CONVERGENCE ON THE
NOSE OF A 60 KNOT 700MB JET SUPPORTING A 3-5 HOUR PERIOD OF SNOW.
THE QUALITY OF DYNAMICS AND MOISTURE COMING TOGETHER SUGGEST THIS
MAY PRODUCE A GENERAL 1-3 INCH SNOW ACROSS MUCH OF THE REGION.
THE SNOW THAT FALLS OVER THE NEXT FEW DAYS WILL BE A THING OF THE
PAST BY MIDWEEK AS ANOTHER UNSEASONABLY STRONG WARM-UP ARRIVES
BEGINNING TUESDAY. IN FACT...FOLLOWING THE GENERAL SNOW MONDAY
EVENING TEMPERATURES WILL RISE OVERNIGHT IN THE MODERATE TO STRONG
WARM ADVECTION REGIME...AND WILL BE WELL ABOVE FREEZING ALREADY BY
TUESDAY MORNING FROM THE FINGER LAKES WESTWARD. ONGOING WARM
ADVECTION WILL SUPPORT HIGHS IN THE MID TO UPPER 40S ACROSS MUCH OF
WESTERN AND CENTRAL NY WITH A MAINLY DRY DAY AS THE WARM SECTOR
MIXES NORTHWARD.
THE WARM FRONT WILL HANG UP EAST OF LAKE ONTARIO WITH LIGHT SNOW
LINGERING ACROSS THE NORTH COUNTRY ON TUESDAY. MAY SEE A LITTLE MORE
MINOR ACCUMULATION TUESDAY MORNING...BUT BY AFTERNOON EVEN THERE THE
WARM AIR WILL BEGIN TO WIN OUT WITH TEMPERATURES RISING ABOVE
FREEZING AND ALLOWING RAIN TO MIX IN WITH ANY LEFTOVER LIGHT SNOW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
TUESDAY NIGHT THE HEART OF THE WARM SECTOR WILL BUILD INTO THE LOWER
LAKES AS A SURFACE LOW MOVES FROM THE UPPER LAKES TO WESTERN QUEBEC
BY WEDNESDAY MORNING. THIS WILL SUPPORT A VERY MILD NIGHT WITH MANY
LOCATIONS NOT DROPPING OUT OF THE 40S...WITH MID 30S EAST OF LAKE
ONTARIO. THE APPROACH OF THE MID LEVEL TROUGH AND BELT OF ENHANCED
LOW/MID LEVEL FLOW WILL SUPPORT INCREASING LARGE SCALE FORCING FOR
ASCENT...WITH RAIN CHANCES GOING UP OVERNIGHT. THE SURFACE COLD
FRONT WILL CROSS THE REGION WEDNESDAY MORNING WITH VERY MILD TEMPS
JUST AHEAD GIVING WAY TO FALLING TEMPS BY AFTERNOON. BEST RAIN
CHANCES WILL BE EARLY...WITH DRYING EXPECTED BY AFTERNOON IF THE
CURRENT MODEL TIMING HOLDS.
COLD ADVECTION BEHIND THE SYSTEM WILL BRING TEMPS DOWN...BUT STILL
ABOVE CLIMO FOR THURSDAY WITH A FEW LIGHT SNOW SHOWERS POSSIBLE EAST
OF THE LAKES.
LATER THURSDAY INTO NEXT WEEKEND FORECAST UNCERTAINTY QUICKLY
INCREASES WITH THE LATEST GFS AND ECMWF RAPIDLY BECOMING
DRAMATICALLY DIFFERENT IN THE SYNOPTIC DETAILS AND EVEN THE LARGE
SCALE PATTERN. THE GFS KEEPS A FLAT TROUGH ON THURSDAY WITH A
GRADUAL AMPLIFICATION NEXT WEEKEND WHICH WOULD TAKE A SOUTHERN
STREAM LOW TOO FAR SOUTH AND EAST TO HAVE MUCH IMPACT ON THE LOWER
LAKES...RESULTING IN A TURN TO COLDER TEMPS NEXT WEEKEND BUT MAINLY
DRY. THE ECMWF ON THE OTHER HAND BRINGS A STRONGER SOUTHERN STREAM
LOW OVER THE LOWER LAKES LATE THURSDAY AND THURSDAY NIGHT WITH RAIN
AND WET SNOW CHANGING TO SNOW. THIS IS FOLLOWED BY A MORE
SIGNIFICANT TROUGH AMPLIFICATION BY SATURDAY NIGHT AND SUNDAY WITH
SOME SEMBLANCE OF ANOTHER OHIO VALLEY LOW BRINGING A GENERAL
SNOWFALL TO THE REGION FOR THE SECOND HALF OF THE WEEKEND.
GIVEN THE LACK OF MODEL CONSISTENCY...WILL STICK CLOSE TO THE
PREVIOUS FORECAST FOR LATE IN THE WEEK INTO NEXT WEEKEND. THE
COMPLEXITY OF THE PATTERN EVOLUTION LATE NEXT WEEK WILL LIKELY
RESULT IN ONGOING MODEL UNCERTAINTY FOR SEVERAL MORE DAYS UNTIL
MODELS BEGIN TO CONVERGE ON A COMMON SOLUTION.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
FOR THE 18Z TAFS...EXPECT VARIABLE CONDITIONS THROUGH ABOUT 21Z.
BY LARGE...IT SHOULD BE PREDOMINANTLY MVFR-VFR CONDITIONS.
HOWEVER...PERIODIC LAKE SNOWS WILL DRASTICALLY LOWER CONDITIONS AT
BUF/IAG/ART AT TIMES. AT 1230 PM...RADAR SHOWS A FAIRLY INTENSE
LAKE EFFECT BAND JUST NORTH OF ART...WHICH WILL LIKELY MEANDER
JUST ENOUGH SOUTH TO IMPACT THE TERMINAL AT TIMES THROUGH MID-AFTERNOON.
AFTER THIS...A SIGNIFICANT SHORTWAVE WILL MOVE ACROSS. THIS WILL
LIKELY PRODUCE A PERIOD OF LIFR CONDITIONS AT ALL SITES...WHICH
WILL LAST A COUPLE HOURS. VSBY BELOW 1/2SM IS LIKELY.
CONDITIONS WILL IMPROVE WITH THE EXIT OF THIS SYSTEM...WITH MAINLY
MVFR CONDITIONS OVERNIGHT. THE EXCEPTION WILL BE IN LAKE EFFECT
BANDS...BUT IN THE WNW FLOW THESE TYPICALLY HAVE ONLY MINOR
IMPACTS ON TAF SITES...THOUGH LOCAL AND BRIEF PERIODS OF LOWER
CONDITIONS ARE POSSIBLE.
OUTLOOK...
MONDAY NIGHT...IFR WITH LIGHT SNOW LIKELY.
TUESDAY...IFR WITH LIGHT SNOW LIKELY EAST OF LAKE ONTARIO...
ELSEWHERE IMPROVING TO MAINLY VFR.
WEDNESDAY...VFR/MVFR WITH A CHANCE OF RAIN SHOWERS.
THURSDAY...VFR/MVFR WITH A CHANCE OF SNOW SHOWERS.
FRIDAY...VFR.
&&
.MARINE...
MODERATELY STRONG SOUTHWESTERLIES AND WESTERLIES WILL CONTINUE
ACROSS THE LOWER LAKES REGION RIGHT INTO MONDAY. THIS WILL RESULT
IN CONDITIONS REMAINING SOLIDLY IN THE SMALL CRAFT ADVISORY RANGE
THROUGH MONDAY MORNING...BEFORE AN APPROACHING WARM FRONT RESULTS
IN DIMINISHING WINDS MONDAY AFTERNOON AND EVENING.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NYZ007-
008.
WINTER WEATHER ADVISORY UNTIL NOON EST MONDAY FOR NYZ004>006.
WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ001>003-010-011.
WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ012-019-020-085.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST MONDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
LEZ020.
SMALL CRAFT ADVISORY UNTIL 4 PM EST MONDAY FOR
LOZ042>045.
&&
$$
SYNOPSIS...JJR
NEAR TERM...APFFEL/JJR
SHORT TERM...HITCHCOCK
LONG TERM...HITCHCOCK
AVIATION...APFFEL
MARINE...APFFEL/JJR
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1210 PM EST SUN JAN 29 2012
.SYNOPSIS...
A FAST MOVING WAVE OF LOW PRESSURE WILL CROSS THE REGION LATE
AFTERNOON THROUGH THIS EVENING...BRINGING A BRIEF PERIOD OF HEAVY
SNOW TO MOST LOCATIONS. THIS WILL BE FOLLOWED BY LAKE SNOWS EAST
OF THE LAKES TONIGHT AS A WESTERLY FLOW OF BRIEFLY COLDER AIR
SPREADS ACROSS THE LOWER LAKES. AN APPROACHING WARM FRONT WILL
THEN BRING ANOTHER ROUND OF WIDESPREAD LIGHT SNOW TO THE AREA LATE
MONDAY AND MONDAY NIGHT... FOLLOWED BY A SIGNIFICANT WARMUP FOR
TUESDAY AND ESPECIALLY WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE FOR WINTER WEATHER ADVISORIES. HAVE ISSUED WINTER WEATHER
ADVISORIES FOR MOST OF THE CWA...WITH THE GREATEST AMOUNTS EAST OF
LAKE ONTARIO...WHERE 4 TO 8 INCHES OF ADDITIONAL SNOWFALL IS
EXPECTED. LESSER AMOUNTS ELSEWHERE...TAPERING DOWN TO AN ADDITIONAL
2 TO 5 INCHES WEST OF ROCHESTER. BECAUSE A SIGNIFICANT SNOW BURST
IS EXPECTED...AND BECAUSE A COUPLE INCHES OF SNOW HAS ALREADY
FALLEN IN THIS AREA...HAVE OPTED TO HANDLE THIS WITH AN ADVISORY.
ALSO...BECAUSE THE EVENT IS BEING INFLUENCED BY BOTH SYNOPTIC AND
LAKE FACTORS...HAVE CARRIED A WINTER WEATHER ADVISORY FOR ALL TO
KEEP OUR MESSAGE SIMPLE. THE MAJORITY OF THE EVENT WILL BE
SYNOPTIC...WITH THE EXCEPTION OF OSWEGO/NORTHERN CAYUGA/WAYNE
COUNTIES...WHERE SIGNIFICANT LAKE SNOWS WILL LINGER LATE TONIGHT
INTO MONDAY.
AS OF NOON...RADAR SHOWS A BAND OF SNOW EXTENDING NORTH OF THE
BUFFALO AND ROCHESTER METRO AREAS. THIS BAND HAS CONTINUED TO
WEAKEN OVER THE PAST COUPLE HOURS...AND IT WILL CONTINUE TO WEAKEN
THROUGH EARLY AFTERNOON. MODELS HAVE NOT HANDLED THIS BAND WELL
AT ALL...WITH THE LIKELY CAUSE A COMBINATION OF MID- LEVEL WARM
AIR ADVECTION AND LAKE EFFECT ENHANCEMENT. EXPECT MOISTURE FROM
THIS BAND TO ADVECT ACROSS LAKE ONTARIO...WHICH WILL LIKELY ENHANCE
SNOWFALL EAST OF LAKE ONTARIO...DESPITE MODEL QPFS.
MODELS ARE CONSISTENT IN BRINGING A SHORTWAVE ACROSS THE REGION
LATE AFTERNOON. THE HRRR AND 12Z RUNS OF THE NAM12/RGEM/GFS BRING A
DECENT SNOW BURST LATE AFTERNOON INTO THIS EVENING. QPFS ARE
GENERALLY BETWEEN .10 AND .25 WITH THIS...WHICH IS MARGINAL FOR
ADVISORIES. HOWEVER...GIVEN THE POTENTIAL SNOWFALL RATES...AND THE
ANTICIPATED FLUFF FACTOR OF THE SNOW...OPTED TO GO WITH THE
ADVISORY.
IMMEDIATELY FOLLOWING THE DEPARTURE OF THE SURFACE WAVE THIS
EVENING...A WESTERLY TO WEST-NORTHWESTERLY FLOW OF COLDER AIR WILL
ONCE AGAIN SET UP ACROSS THE LOWER LAKES...WITH 850 MB TEMPS
DROPPING FROM AROUND -10C/-11C EARLY THIS EVENING TO AROUND -14C
BY MIDNIGHT. THIS WILL TRIGGER A RENEWED ROUND OF LAKE SNOWS EAST
/EAST-SOUTHEAST OF BOTH LAKES. OFF LAKE ERIE...THE RELATIVELY
SHALLOW MOISTURE FIELD AND LOW CAPPING INVERSION HEIGHT OF 5 KFT
SHOULD HELP KEEP THE LAKE SNOWS FAIRLY MINIMAL IN NATURE EAST OF
THE LAKE...WHERE ABOUT 1 TO 3 INCHES OF FRESH ACCUMULATION WILL BE
POSSIBLE THROUGH THE END OF THE NIGHT. OFF LAKE ONTARIO...THINGS
WILL BE A DIFFERENT STORY AS A MUCH DEEPER MOISTURE
FIELD...STRONGER LIFT...AND A CAPPING INVERSION OF AROUND 9-10 KFT
SHOULD ALLOW FOR ANOTHER ROUND OF ADVISORY-CRITERIA SNOWS. THE
MAIN QUESTION AT THIS POINT IS EXACTLY WHERE THESE WILL BE...AS
THE MODELS CONTINUE TO SHOW SOME VARIATION IN THE EXACT LOCATION
OF THE LAKE SNOW BAND...RANGING FROM THE 00Z NAM`S DEPICTION OF A
BAND EAST-SOUTHEAST OF THE LAKE...TO THE 00Z RGEM`S TUG HILL
POSITIONING.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
AT THE START OF THE PERIOD SOME LAKE EFFECT SNOW WILL PERSIST ON
MONDAY EAST OF THE LAKES WITH 850MB TEMPS BOTTOMING OUT AROUND -14C
DURING THE MORNING.
OFF LAKE ERIE...A SURFACE RIDGE WILL BUILD ACROSS THE LAKE DURING
THE MORNING AND DISRUPT/BACK THE LOW LEVEL FLOW AND ALSO DRY OUT THE
LOW LEVELS. THIS SHOULD BRING A QUICK END TO LAKE EFFECT WITH
LINGERING SCATTERED SNOW SHOWERS ACROSS THE WESTERN SOUTHERN TIER
LIFTING NORTH TOWARDS THE BUF SOUTHTOWNS AND FALLING APART WITH ONLY
VERY MINOR DUSTING TO AN INCH ACCUMULATIONS ON THE HILLS IN THE
EARLY MORNING.
OFF LAKE ONTARIO...CONDITIONS WILL STILL BE MORE FAVORABLE THROUGH
THE MORNING HOURS WITH LAKE INDUCED EQUILIBRIUM LEVELS AROUND 10K
FEET...DETERIORATING TO LESS THAN 7K FEET BY AFTERNOON AS THE
SURFACE RIDGE BUILDS ACROSS LAKE ONTARIO. THERE REMAINS SOME SPREAD
WITH BAND PLACEMENT IN THE LATEST 00Z MODEL SUITE WITH THE CANADIAN
GEM HOLDING THE LAKE EFFECT ACROSS NORTHERN OSWEGO COUNTY AND THE
SOUTHERN TUG HILL...WHILE THE NAM DROPS THE BAND INTO SOUTHERN
OSWEGO COUNTY AND EVEN CLIPS N.CAYUGA AND NE WAYNE COUNTY FOR
AWHILE. FOR NOW HAVE PLACED THE BAND ACROSS CENTRAL OSWEGO COUNTY
BUT THIS MAY NEED TO BE TWEAKED AS SHORT TERM MODEL GUIDANCE
CONVERGES ON A COMMON SOLUTION FOR BAND PLACEMENT. SYNOPTIC SCALE
MOISTURE IS DRYING OUT BY MONDAY MORNING...BUT MODERATE INSTABILITY
AND LONG FETCH SUGGEST THE POTENTIAL FOR SEVERAL MORE INCHES IN
PERSISTENT BANDS THROUGH THE FIRST HALF OF MONDAY. AN ADVISORY WILL
LIKELY BE NEEDED FOR THIS INTO MONDAY...BUT AS STATED IN THE NEAR
TERM DISCUSSION WE WILL WAIT UNTIL THE CURRENT ADVISORY EXPIRES
BEFORE RAISING A NEW ONE TO AVOID CONFUSION.
THE LAKE ONTARIO LAKE EFFECT WILL WEAKEN AND END MONDAY AFTERNOON AS
THE SURFACE RIDGE CROSSES THE LAKE AND DISRUPTS THE LOW LEVEL FLOW.
OUR ATTENTION THEN QUICKLY TURNS BACK TO THE SYNOPTIC SCALE. PAST
FEW RUNS OF THE GFS AND SREF HAVE BEEN CONSISTENT IN DEVELOPING AN
AREA OF LIGHT SNOW LATE MONDAY AFTERNOON ACROSS WESTERN NY...THEN
SPREADING EAST ACROSS THE REST OF THE AREA MONDAY NIGHT. THIS AREA
OF SNOW WILL BE SUPPORTED BY A MODERATE TO STRONG WARM ADVECTION
REGIME WITH AMPLE ISENTROPIC UPGLIDE AND MOISTURE CONVERGENCE ON THE
NOSE OF A 60 KNOT 700MB JET SUPPORTING A 3-5 HOUR PERIOD OF SNOW.
THE QUALITY OF DYNAMICS AND MOISTURE COMING TOGETHER SUGGEST THIS
MAY PRODUCE A GENERAL 1-3 INCH SNOW ACROSS MUCH OF THE REGION.
THE SNOW THAT FALLS OVER THE NEXT FEW DAYS WILL BE A THING OF THE
PAST BY MIDWEEK AS ANOTHER UNSEASONABLY STRONG WARM-UP ARRIVES
BEGINNING TUESDAY. IN FACT...FOLLOWING THE GENERAL SNOW MONDAY
EVENING TEMPERATURES WILL RISE OVERNIGHT IN THE MODERATE TO STRONG
WARM ADVECTION REGIME...AND WILL BE WELL ABOVE FREEZING ALREADY BY
TUESDAY MORNING FROM THE FINGER LAKES WESTWARD. ONGOING WARM
ADVECTION WILL SUPPORT HIGHS IN THE MID TO UPPER 40S ACROSS MUCH OF
WESTERN AND CENTRAL NY WITH A MAINLY DRY DAY AS THE WARM SECTOR
MIXES NORTHWARD.
THE WARM FRONT WILL HANG UP EAST OF LAKE ONTARIO WITH LIGHT SNOW
LINGERING ACROSS THE NORTH COUNTRY ON TUESDAY. MAY SEE A LITTLE MORE
MINOR ACCUMULATION TUESDAY MORNING...BUT BY AFTERNOON EVEN THERE THE
WARM AIR WILL BEGIN TO WIN OUT WITH TEMPERATURES RISING ABOVE
FREEZING AND ALLOWING RAIN TO MIX IN WITH ANY LEFTOVER LIGHT SNOW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
TUESDAY NIGHT THE HEART OF THE WARM SECTOR WILL BUILD INTO THE LOWER
LAKES AS A SURFACE LOW MOVES FROM THE UPPER LAKES TO WESTERN QUEBEC
BY WEDNESDAY MORNING. THIS WILL SUPPORT A VERY MILD NIGHT WITH MANY
LOCATIONS NOT DROPPING OUT OF THE 40S...WITH MID 30S EAST OF LAKE
ONTARIO. THE APPROACH OF THE MID LEVEL TROUGH AND BELT OF ENHANCED
LOW/MID LEVEL FLOW WILL SUPPORT INCREASING LARGE SCALE FORCING FOR
ASCENT...WITH RAIN CHANCES GOING UP OVERNIGHT. THE SURFACE COLD
FRONT WILL CROSS THE REGION WEDNESDAY MORNING WITH VERY MILD TEMPS
JUST AHEAD GIVING WAY TO FALLING TEMPS BY AFTERNOON. BEST RAIN
CHANCES WILL BE EARLY...WITH DRYING EXPECTED BY AFTERNOON IF THE
CURRENT MODEL TIMING HOLDS.
COLD ADVECTION BEHIND THE SYSTEM WILL BRING TEMPS DOWN...BUT STILL
ABOVE CLIMO FOR THURSDAY WITH A FEW LIGHT SNOW SHOWERS POSSIBLE EAST
OF THE LAKES.
LATER THURSDAY INTO NEXT WEEKEND FORECAST UNCERTAINTY QUICKLY
INCREASES WITH THE LATEST GFS AND ECMWF RAPIDLY BECOMING
DRAMATICALLY DIFFERENT IN THE SYNOPTIC DETAILS AND EVEN THE LARGE
SCALE PATTERN. THE GFS KEEPS A FLAT TROUGH ON THURSDAY WITH A
GRADUAL AMPLIFICATION NEXT WEEKEND WHICH WOULD TAKE A SOUTHERN
STREAM LOW TOO FAR SOUTH AND EAST TO HAVE MUCH IMPACT ON THE LOWER
LAKES...RESULTING IN A TURN TO COLDER TEMPS NEXT WEEKEND BUT MAINLY
DRY. THE ECMWF ON THE OTHER HAND BRINGS A STRONGER SOUTHERN STREAM
LOW OVER THE LOWER LAKES LATE THURSDAY AND THURSDAY NIGHT WITH RAIN
AND WET SNOW CHANGING TO SNOW. THIS IS FOLLOWED BY A MORE
SIGNIFICANT TROUGH AMPLIFICATION BY SATURDAY NIGHT AND SUNDAY WITH
SOME SEMBLANCE OF ANOTHER OHIO VALLEY LOW BRINGING A GENERAL
SNOWFALL TO THE REGION FOR THE SECOND HALF OF THE WEEKEND.
GIVEN THE LACK OF MODEL CONSISTENCY...WILL STICK CLOSE TO THE
PREVIOUS FORECAST FOR LATE IN THE WEEK INTO NEXT WEEKEND. THE
COMPLEXITY OF THE PATTERN EVOLUTION LATE NEXT WEEK WILL LIKELY
RESULT IN ONGOING MODEL UNCERTAINTY FOR SEVERAL MORE DAYS UNTIL
MODELS BEGIN TO CONVERGE ON A COMMON SOLUTION.
&&
.AVIATION /17Z SUNDAY THROUGH THURSDAY/...
FOR THE 15Z AMD...EXPECT VARIABLE CONDITIONS THROUGH MID-
AFTERNOON. PREDOMINANTLY MVFR-VFR CONDITIONS ARE EXPECTED.
HOWEVER...PERIODIC LAKE SNOWS WILL DRASTICALLY LOWER CONDITIONS AT
BUF/IAG/ART AT TIMES THIS MORNING. TAFS BASICALLY FOLLOWING RADAR
TRENDS DURING THIS TIME...WITH PERIODS OF VSBY BELOW 1SM POSSIBLE
AT THESE TAF LOCATIONS.
AFTER 20Z...A SIGNIFICANT SHORTWAVE WILL MOVE ACROSS. THIS WILL
LIKELY PRODUCE A PERIOD OF LIFR CONDITIONS AT ALL SITES...WHICH
WILL LAST A COUPLE HOURS. VSBY BELOW 1/2SM IS LIKELY.
CONDITIONS WILL IMPROVE WITH THE EXIT OF THIS SHORTWAVE...WITH
MAINLY MVFR CONDITIONS OVERNIGHT. THE EXCEPTION WILL BE IN LAKE
EFFECT BANDS...BUT IN THE WNW FLOW THESE TYPICALLY HAVE ONLY MINOR
IMPACTS ON TAF SITES...THOUGH LOCAL AND BRIEF PERIODS OF LOWER
CONDITIONS ARE POSSIBLE.
OUTLOOK...
MONDAY...MVFR/IFR IN DIMINISHING LAKE SNOWS EAST OF THE LAKES...
MAINLY VFR ELSEWHERE.
MONDAY NIGHT...IFR WITH LIGHT SNOW LIKELY.
TUESDAY...IFR WITH LIGHT SNOW LIKELY EAST OF LAKE ONTARIO...
ELSEWHERE IMPROVING TO MAINLY VFR.
WEDNESDAY...VFR/MVFR WITH A CHANCE OF RAIN SHOWERS.
THURSDAY...VFR/MVFR WITH A CHANCE OF SNOW SHOWERS.
&&
.MARINE...
MODERATELY STRONG SOUTHWESTERLIES AND WESTERLIES WILL CONTINUE
ACROSS THE LOWER LAKES REGION RIGHT INTO MONDAY. THIS WILL RESULT
IN CONDITIONS REMAINING SOLIDLY IN THE SMALL CRAFT ADVISORY RANGE
THROUGH MONDAY MORNING...BEFORE AN APPROACHING WARM FRONT RESULTS
IN DIMINISHING WINDS MONDAY AFTERNOON AND EVENING.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NYZ007-
008.
WINTER WEATHER ADVISORY UNTIL NOON EST MONDAY FOR NYZ004>006.
WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ001>003-010-011.
WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ012-019-020-085.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST MONDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
LEZ020.
SMALL CRAFT ADVISORY UNTIL 4 PM EST MONDAY FOR
LOZ042>045.
&&
$$
SYNOPSIS...JJR
NEAR TERM...APFFEL/JJR
SHORT TERM...HITCHCOCK
LONG TERM...HITCHCOCK
AVIATION...APFFEL/JJR
MARINE...APFFEL/JJR
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1240 PM EST SUN JAN 29 2012
.SYNOPSIS...
A CLIPPER WILL WORK ITS WAY ACROSS THE SOUTHERN GREAT LAKES TODAY
AND BRING ANOTHER SHOT OF LIGHT SNOW TO THE AREA. A RIDGE MOVES
ACROSS TONIGHT. A WARM FRONT WILL LIFT NORTH MONDAY AND MONDAY
EVENING AND WILL BRING TEMPERATURES FOR MID WEEK BACK WELL ABOVE
NORMAL.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SURFACE LOW MOVING INTO SOUTH CENTRAL MICHIGAN WITH TROF/COLD
FRONT EXTENDING SSW FROM THE LOW. ALOFT MODELS SHOW A FAIRLY
VIGOROUS SHORT WAVE ASSOCIATED WITH THE SYSTEM WHICH WILL TRANSIT
NORTHERN OHIO THIS AFTERNOON. RADAR AND OBS SHOW ASSOCIATED SNOW
MOVING INTO FAR NWRN OHIO THIS HOUR WITH DEFIANCE NOW REPORTING
3/4SM VISIBILITY IN SNOW. EXPECT SNOW TO BEGIN IN TOL THIS HOUR
WITH SNOW REACHING KCLE VICINITY AROUND 3PM BASED ON RADAR TIMING.
HAVE ADJUSTED POPS AND WX IN GRIDS TO REFLECT THIS. ALTHOUGH POPS
ARE HIGH THIS WILL NOT BE AN ALL DAY EVENT AND IN FACE EXPECT ONLY
A LIGHT ACCUM...WITH MOST PLACES AROUND AN INCH. SOME OF THE
HIGHER ELEVATIONS FROM MFD NE ACROSS THE SNOW BELT COULD SEE
BETWEEN 1 AND 2 OF SNOWFALL HOWEVER TEMPS CURRENTLY IN THE MID
30S SO ACTUAL ACCUMS WILL STRUGGLE...AT LEAST DURING THE DAY.
ALSO...SNOW BEING BEING ENHANCED OFF LAKE MICHIGAN AND THIS WILL
LIKELY OCCUR THIS EVENING AND TONIGHT OFF LAKE ERIE INTO NERN OHIO
AND NWRN PA...BUT WILL NOT MAKE CHANGES THIS UPDATE. OTHER ISSUE
IS THE WIND. THE RUC SHOWS THE CORE OF THE HIGH WINDS AT 850MB
WILL MOVE ACROSS SOUTHERN OHIO...ALTHOUGH AT 925MB MODEL SHOWS THE
HIGHEST CORE (40KTS) MOVES ACROSS NRN OHIO. AT THIS TIME WILL
CONTINUE WITH THE WIND ADVISORY GIVEN THE EXPECTATION THAT THE
AIRMASS IS MORE UNSTABLE AND WILL ALLOW FOR DEEPER MIXING THAN
YDAY BUT THINKING THIS WILL BE A MARGINAL EVENT AND LIKELY
CONFINED TO THE VICINITY OF THE FRONT.
PREVIOUS...A CLIPPER TO COME ACROSS THE SOUTHERN GREAT LAKES AND
OHIO VALLEY TODAY WILL BRING ANOTHER QUICK AND LIGHT SNOW TO THE
ENTIRE FORECAST AREA. AS SHORTWAVE CROSSES AND TROUGH
SHARPENS...WINDS WILL PICK UP AND GUST. HAVE ISSUED A WIND
ADVISORY FOR THE SOUTHERN HALF OF THE AREA. THIS IS WHERE GUSTS TO
50 MPH LOOK MORE LIKELY. MIXING POTENTIAL IS GOOD TODAY. AS FAR AS
SNOW TIMING GOES...LOOKING AT 11 AM TO 5 PM FOR THE BULK OF IT.
ACROSS NE OHIO/NW PA...BETTER SNOW WILL START THIS AFTERNOON AND
LINGER INTO THE EVENING WITH SOME BETTER CONVERGENCE ALONG THE
LAKESHORE/SNOWBELT. MOST PLACES WILL BE AROUND AN INCH...BUT THE
SNOWBELT MAY GET UPWARDS OF 3 INCHES. WENT ON THE WARMER SIDE OF
TEMPS...THINKING WE COULD GAIN SEVERAL DEGREES BEFORE THE SNOW
BEGINS. WILL MENTION POSSIBLE RAIN/SNOW MIX...BUT SNOW LOOKS LIKE
THE BETTER OPTION WITH TEMPS LIKELY DROPPING A FEW DEGREES WITH
THE ARRIVAL OF THE PRECIPITATION. NO EARLY MORNING CHANGES MADE TO
THE FORECAST FOR TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
SNOW MAY BE LINGERING ACROSS THE EAST HALF DURING THE EVENING
HOURS...THEN TRANSITION TO SOME LIGHT LAKE EFFECT. AFTER ABOUT
03Z TEMPS GET COLD ENOUGH TO HAVE A DECENT LAKE INFLUENCE. WILL
HAVE LIKELY POPS FOR THE FAR EASTERN SNOWBELT THROUGH MOST OF THE
NIGHT. ONLY LIGHT AMOUNTS FORECAST THOUGH AS WE GET SOME
SIGNIFICANT DRYING IN AT THE SAME TIME AS THE COLDER AIR.
A WARM FRONT LIFTS ACROSS THE AREA MONDAY AND MONDAY EVENING.
TEMPERATURES ONCE AGAIN WARM AND WILL BE FORECAST TO TOP 40 IN
MANY PLACES MONDAY. THE ENTIRE AREA LOOKS TO BE WELL INTO THE 40S
FOR TUESDAY. MODELS HAVE BEEN FAIRLY CONSISTENT IN BRINGING SOME
WARM FRONTAL PRECIP INTO THE FAR NORTHEAST MONDAY. HAVE CONTINUED
THE CHANCE POPS AND DEPENDING ON TEMPS MAY BE LIGHT SNOW OR RAIN.
A FEW SPRINKLES OR FLURRIES MAY OCCUR ON THE FRINGES.
TUESDAY WILL LIKELY BE DRY AS WE ARE STILL A WAYS FROM ANY
FORCING. COLD FRONT TIMING APPEARS TO BE EARLY WEDNESDAY MORNING.
SCATTERED SHOWERS WILL ACCOMPANY THE FRONT OVERNIGHT TUESDAY. WE
GET HIGH PRESSURE AND DRYING TO BUILD IN QUICKLY ON WEDNESDAY. THE
FRONT DOES NOT HAVE A TIGHT GRADIENT IN TEMPERATURE AND NO REAL
COLD AIR PUSH AS THE FLOW FLATTENS OUT AGAIN. WILL KEEP TEMPS IN
THE 40S STILL.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
MODELS ARE CONTINUING TO STRUGGLE IN THE EXTENDED. HAVE ENDED UP
GOING WITH A HPC AND ECMWF BLEND. THIS WOULD BRING A CHANCE OF RAIN
TO THE AREA ON THURSDAY AS LOW PRESSURE TRACKS ACROSS OHIO. WE THEN
AWAIT ANOTHER PIECE OF JET ENERGY TO DIVE INTO A TROUGH THAT WILL BE
LOCATED OVER THE EASTERN HALF OF THE US. A TROUGH IN THIS POSITION
WILL EVENTUALLY DUMP SOME COLD AIR INTO THE REGION. HOWEVER IT
APPEARS THIS WONT OCCUR UNTIL SATURDAY NIGHT INTO SUNDAY.
HIGHS WILL CONTINUE ON THE WARM SIDE ON THURSDAY WITH HIGHS INTO THE
40S. COOLER FOR FRIDAY AND SATURDAY WITH HIGHS CLOSER TO SEASONAL
AVERAGES.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
CLIPPER SYSTEM NOW INTO SE LOWER MICHIGAN WILL MOVE EAST OF THE
AREA THIS EVENING...THEN MOVE OFF THE MID ATLANTIC COAST
OVERNIGHT. THAT SAID EXPECT SNOW NOW INTO NW OHIO TO SPREAD EAST
ACROSS ENTIRE AREA THIS AFTERNOON/EVENING AND TO BE EAST OF THE
AREA BY LATE EVENING. MAY LINGER SOME EXTREME NE OH/NW PA. EXPECT
A WIDESPREAD INCH OR SO BEFORE SNOW ENDS.
EXPECT SW WINDS AHEAD OF FRONT GUSTING INTO MID 30S. WINDS TURN TO
THE WEST BEHIND THE FRONT. WINDS WILL BEGIN TO DIMINISH AFTER
SUNSET AND THEN TURN BACK TO THE SOUTH-SOUTHWEST OVERNIGHT.
ANOTHER CLIPPER WILL SWING ACROSS THE CENTRAL GREAT LAKES TODAY.
EXPECT TO SEE CEILINGS LOWER THROUGH THE MORNING WITH SNOW
ARRIVING IN NW OHIO NEAR 16Z...CENTRAL AREAS AROUND 17Z AND
EASTERN AREAS AROUND 19Z. AS THE SNOW ARRIVES EXPECT TO SEE
CEILINGS DROP TO MVFR LEVELS. THERE WILL BE A 2 TO 3 HOUR WINDOW OF
MODERATE SNOWFALL WITH IFR CONDITIONS LIKELY. THE SNOW MAY LINGER
A BIT LONGER ACROSS THE EASTERN THIRD OF THE REGION...POSSIBLY
INTO THE EVENING.
THE OTHER CONCERN FOR THE DAY WILL BE GUSTY WINDS...ESPECIALLY
ACROSS THE SOUTHERN TAF SITES. SOUTHWEST TO WEST WINDS MAY GUST
OVER 40 KNOTS SOUTH OF A KFDY TO KYNG LINE. NORTH OF THIS LINE 30
TO 35 KNOT GUSTS WILL BE POSSIBLE. THE WINDS WILL LIKELY BE THE
STRONGEST JUST AHEAD OF THE AREA OF SNOWFALL AND IN THE WAKE OF THE
FRONT THAT WILL MOVE ACROSS THE AREA THROUGH THE AFTERNOON. THE
GUSTY WINDS WILL SUBSIDE BY EARLY EVENING.
.OUTLOOK...NON-VFR CONDITIONS ARE POSSIBLE TUESDAY AFTERNOON
THROUGH WEDNESDAY AFTERNOON IN PERIODS OF RAIN.
&&
.MARINE...
ANOTHER CLIPPER TYPE STORM SYSTEM WILL SWEEP ACROSS THE CENTRAL
GREAT LAKES TODAY WITH A COLD FRONT CROSSING THE LAKE THIS
AFTERNOON. WINDS WILL REMAIN SOUTHWEST AHEAD OF THIS CLIPPER BUT
WILL SHIFT TO THE WEST AS THE FRONT PASSES. SOUTHWEST WINDS OF 15
TO 25 KNOTS WILL PICK UP TO AROUND 30 KNOTS AS THE FRONT PASSES.
SO WITH THE LIGHTER WINDS THIS MORNING WE WILL BE ABLE TO DROP THE
GALE WARNING AND THE LOW WATER ADVISORY. HOWEVER WIND SPEEDS AND
WAVES WILL REMAIN HIGH ENOUGH TO KEEP A SMALL CRAFT ADVISORY GOING
THROUGH THE DAY. ACTUALLY WIND SPEEDS WILL REMAIN HIGH ENOUGH TO
KEEP A SMALL CRAFT ADVISORY GOING INTO AT LEAST EARLY MONDAY
MORNING.
THE NEXT STORM SYSTEM WILL BRING INCREASING SOUTH TO SOUTHWEST WINDS
TO THE LAKE BY TUESDAY AFTERNOON AND WILL LIKELY GET STRONGER IN
THE WAKE OF A COLD FRONT ON WEDNESDAY. THIS STORM SYSTEM MAY END UP
REQUIRING A GALE WARNING.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY UNTIL 6 PM EST THIS EVENING FOR OHZ017-020>023-
027>033-036>038-047.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST MONDAY FOR LEZ142>149.
&&
$$
SYNOPSIS...OUDEMAN
NEAR TERM...TK/OUDEMAN
SHORT TERM...OUDEMAN
LONG TERM...MULLEN
AVIATION...DJB
MARINE...MULLEN
AREA FORECAST DISCUSSION...UPDATED
NWS CLEVELAND OH
1221 PM EST SUN JAN 29 2012
.SYNOPSIS...
A CLIPPER WILL WORK ITS WAY ACROSS THE SOUTHERN GREAT LAKES TODAY
AND BRING ANOTHER SHOT OF LIGHT SNOW TO THE AREA. A RIDGE MOVES
ACROSS TONIGHT. A WARM FRONT WILL LIFT NORTH MONDAY AND MONDAY
EVENING AND WILL BRING TEMPERATURES FOR MID WEEK BACK WELL ABOVE
NORMAL.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SURFACE LOW MOVING INTO SOUTH CENTRAL MICHIGAN WITH TROF/COLD
FRONT EXTENDING SSW FROM THE LOW. ALOFT MODELS SHOW A FAIRLY
VIGOROUS SHORT WAVE ASSOCIATED WITH THE SYSTEM WHICH WILL TRANSIT
NORTHERN OHIO THIS AFTERNOON. RADAR AND OBS SHOW ASSOCIATED SNOW
MOVING INTO FAR NWRN OHIO THIS HOUR WITH DEFIANCE NOW REPORTING
3/4SM VISIBILITY IN SNOW. EXPECT SNOW TO BEGIN IN TOL THIS HOUR
WITH SNOW REACHING KCLE VICINITY AROUND 3PM BASED ON RADAR TIMING.
HAVE ADJUSTED POPS AND WX IN GRIDS TO REFLECT THIS. ALTHOUGH POPS
ARE HIGH THIS WILL NOT BE AN ALL DAY EVENT AND IN FACE EXPECT ONLY
A LIGHT ACCUM...WITH MOST PLACES AROUND AN INCH. SOME OF THE
HIGHER ELEVATIONS FROM MFD NE ACROSS THE SNOW BELT COULD SEE
BETWEEN 1 AND 2 OF SNOWFALL HOWEVER TEMPS CURRENTLY IN THE MID
30S SO ACTUAL ACCUMS WILL STRUGGLE...AT LEAST DURING THE DAY.
ALSO...SNOW BEING BEING ENHANCED OFF LAKE MICHIGAN AND THIS WILL
LIKELY OCCUR THIS EVENING AND TONIGHT OFF LAKE ERIE INTO NERN OHIO
AND NWRN PA...BUT WILL NOT MAKE CHANGES THIS UPDATE. OTHER ISSUE
IS THE WIND. THE RUC SHOWS THE CORE OF THE HIGH WINDS AT 850MB
WILL MOVE ACROSS SOUTHERN OHIO...ALTHOUGH AT 925MB MODEL SHOWS THE
HIGHEST CORE (40KTS) MOVES ACROSS NRN OHIO. AT THIS TIME WILL
CONTINUE WITH THE WIND ADVISORY GIVEN THE EXPECTATION THAT THE
AIRMASS IS MORE UNSTABLE AND WILL ALLOW FOR DEEPER MIXING THAN
YDAY BUT THINKING THIS WILL BE A MARGINAL EVENT AND LIKELY
CONFINED TO THE VICINITY OF THE FRONT.
PREVIOUS...A CLIPPER TO COME ACROSS THE SOUTHERN GREAT LAKES AND
OHIO VALLEY TODAY WILL BRING ANOTHER QUICK AND LIGHT SNOW TO THE
ENTIRE FORECAST AREA. AS SHORTWAVE CROSSES AND TROUGH
SHARPENS...WINDS WILL PICK UP AND GUST. HAVE ISSUED A WIND
ADVISORY FOR THE SOUTHERN HALF OF THE AREA. THIS IS WHERE GUSTS TO
50 MPH LOOK MORE LIKELY. MIXING POTENTIAL IS GOOD TODAY. AS FAR AS
SNOW TIMING GOES...LOOKING AT 11 AM TO 5 PM FOR THE BULK OF IT.
ACROSS NE OHIO/NW PA...BETTER SNOW WILL START THIS AFTERNOON AND
LINGER INTO THE EVENING WITH SOME BETTER CONVERGENCE ALONG THE
LAKESHORE/SNOWBELT. MOST PLACES WILL BE AROUND AN INCH...BUT THE
SNOWBELT MAY GET UPWARDS OF 3 INCHES. WENT ON THE WARMER SIDE OF
TEMPS...THINKING WE COULD GAIN SEVERAL DEGREES BEFORE THE SNOW
BEGINS. WILL MENTION POSSIBLE RAIN/SNOW MIX...BUT SNOW LOOKS LIKE
THE BETTER OPTION WITH TEMPS LIKELY DROPPING A FEW DEGREES WITH
THE ARRIVAL OF THE PRECIPITATION. NO EARLY MORNING CHANGES MADE TO
THE FORECAST FOR TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
SNOW MAY BE LINGERING ACROSS THE EAST HALF DURING THE EVENING
HOURS...THEN TRANSITION TO SOME LIGHT LAKE EFFECT. AFTER ABOUT
03Z TEMPS GET COLD ENOUGH TO HAVE A DECENT LAKE INFLUENCE. WILL
HAVE LIKELY POPS FOR THE FAR EASTERN SNOWBELT THROUGH MOST OF THE
NIGHT. ONLY LIGHT AMOUNTS FORECAST THOUGH AS WE GET SOME
SIGNIFICANT DRYING IN AT THE SAME TIME AS THE COLDER AIR.
A WARM FRONT LIFTS ACROSS THE AREA MONDAY AND MONDAY EVENING.
TEMPERATURES ONCE AGAIN WARM AND WILL BE FORECAST TO TOP 40 IN
MANY PLACES MONDAY. THE ENTIRE AREA LOOKS TO BE WELL INTO THE 40S
FOR TUESDAY. MODELS HAVE BEEN FAIRLY CONSISTENT IN BRINGING SOME
WARM FRONTAL PRECIP INTO THE FAR NORTHEAST MONDAY. HAVE CONTINUED
THE CHANCE POPS AND DEPENDING ON TEMPS MAY BE LIGHT SNOW OR RAIN.
A FEW SPRINKLES OR FLURRIES MAY OCCUR ON THE FRINGES.
TUESDAY WILL LIKELY BE DRY AS WE ARE STILL A WAYS FROM ANY
FORCING. COLD FRONT TIMING APPEARS TO BE EARLY WEDNESDAY MORNING.
SCATTERED SHOWERS WILL ACCOMPANY THE FRONT OVERNIGHT TUESDAY. WE
GET HIGH PRESSURE AND DRYING TO BUILD IN QUICKLY ON WEDNESDAY. THE
FRONT DOES NOT HAVE A TIGHT GRADIENT IN TEMPERATURE AND NO REAL
COLD AIR PUSH AS THE FLOW FLATTENS OUT AGAIN. WILL KEEP TEMPS IN
THE 40S STILL.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
MODELS ARE CONTINUING TO STRUGGLE IN THE EXTENDED. HAVE ENDED UP
GOING WITH A HPC AND ECMWF BLEND. THIS WOULD BRING A CHANCE OF RAIN
TO THE AREA ON THURSDAY AS LOW PRESSURE TRACKS ACROSS OHIO. WE THEN
AWAIT ANOTHER PIECE OF JET ENERGY TO DIVE INTO A TROUGH THAT WILL BE
LOCATED OVER THE EASTERN HALF OF THE US. A TROUGH IN THIS POSITION
WILL EVENTUALLY DUMP SOME COLD AIR INTO THE REGION. HOWEVER IT
APPEARS THIS WONT OCCUR UNTIL SATURDAY NIGHT INTO SUNDAY.
HIGHS WILL CONTINUE ON THE WARM SIDE ON THURSDAY WITH HIGHS INTO THE
40S. COOLER FOR FRIDAY AND SATURDAY WITH HIGHS CLOSER TO SEASONAL
AVERAGES.
&&
.AVIATION /17Z SUNDAY THROUGH THURSDAY/...
ANOTHER CLIPPER WILL SWING ACROSS THE CENTRAL GREAT LAKES TODAY.
EXPECT TO SEE CEILINGS LOWER THROUGH THE MORNING WITH SNOW
ARRIVING IN NW OHIO NEAR 16Z...CENTRAL AREAS AROUND 17Z AND
EASTERN AREAS AROUND 19Z. AS THE SNOW ARRIVES EXPECT TO SEE
CEILINGS DROP TO MVFR LEVELS. THERE WILL BE A 2 TO 3 HOUR WINDOW OF
MODERATE SNOWFALL WITH IFR CONDITIONS LIKELY. THE SNOW MAY LINGER
A BIT LONGER ACROSS THE EASTERN THIRD OF THE REGION...POSSIBLY
INTO THE EVENING.
THE OTHER CONCERN FOR THE DAY WILL BE GUSTY WINDS...ESPECIALLY
ACROSS THE SOUTHERN TAF SITES. SOUTHWEST TO WEST WINDS MAY GUST
OVER 40 KNOTS SOUTH OF A KFDY TO KYNG LINE. NORTH OF THIS LINE 30
TO 35 KNOT GUSTS WILL BE POSSIBLE. THE WINDS WILL LIKELY BE THE
STRONGEST JUST AHEAD OF THE AREA OF SNOWFALL AND IN THE WAKE OF THE
FRONT THAT WILL MOVE ACROSS THE AREA THROUGH THE AFTERNOON. THE
GUSTY WINDS WILL SUBSIDE BY EARLY EVENING.
.OUTLOOK...NON-VFR CONDITIONS ARE POSSIBLE TUESDAY AFTERNOON
THROUGH WEDNESDAY AFTERNOON IN PERIODS OF RAIN.
&&
.MARINE...
ANOTHER CLIPPER TYPE STORM SYSTEM WILL SWEEP ACROSS THE CENTRAL
GREAT LAKES TODAY WITH A COLD FRONT CROSSING THE LAKE THIS
AFTERNOON. WINDS WILL REMAIN SOUTHWEST AHEAD OF THIS CLIPPER BUT
WILL SHIFT TO THE WEST AS THE FRONT PASSES. SOUTHWEST WINDS OF 15
TO 25 KNOTS WILL PICK UP TO AROUND 30 KNOTS AS THE FRONT PASSES.
SO WITH THE LIGHTER WINDS THIS MORNING WE WILL BE ABLE TO DROP THE
GALE WARNING AND THE LOW WATER ADVISORY. HOWEVER WIND SPEEDS AND
WAVES WILL REMAIN HIGH ENOUGH TO KEEP A SMALL CRAFT ADVISORY GOING
THROUGH THE DAY. ACTUALLY WIND SPEEDS WILL REMAIN HIGH ENOUGH TO
KEEP A SMALL CRAFT ADVISORY GOING INTO AT LEAST EARLY MONDAY
MORNING.
THE NEXT STORM SYSTEM WILL BRING INCREASING SOUTH TO SOUTHWEST WINDS
TO THE LAKE BY TUESDAY AFTERNOON AND WILL LIKELY GET STRONGER IN
THE WAKE OF A COLD FRONT ON WEDNESDAY. THIS STORM SYSTEM MAY END UP
REQUIRING A GALE WARNING.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY UNTIL 6 PM EST THIS EVENING FOR OHZ017-020>023-
027>033-036>038-047.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST MONDAY FOR LEZ142>149.
&&
$$
SYNOPSIS...OUDEMAN
NEAR TERM...TK/OUDEMAN
SHORT TERM...OUDEMAN
LONG TERM...MULLEN
AVIATION...MULLEN
MARINE...MULLEN
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
219 PM CST SUN JAN 29 2012
.SYNOPSIS...MORE MILD WEATHER.
MODEST LARGE SCALE TROF OVER THE ERN CONUS WL SHIFT NEWD THE NEXT
COUPLE DAYS...PUTTING US BACK INTO WHAT HAS BECOME THE PATTERN OF
THE WINTER...A BROAD SOMEWHAT SPLIT ZONAL REGIME. HEIGHTS OVER WRN
CANADA WL GRADUALLY RISE LATER THIS WK. THAT WL EVENTUALLY FAVOR A
RETURN TO AN ERN TROF. MODELS OFFERED VARYING IDEAS ON HOW
SHARP/STG THE WRN RIDGE WL BECOME...AND THAT WILL MODULATE THE
STRENGTH OF THE DOWNSTREAM TROF. PERSISTENCE WOULD FAVOR THE
LESS AMPLIFIED OF THE GUIDANCE SOLUTIONS.
AFTER A RELATIVELY COLD NGT TNGT...TEMPS WL WARM TO SIGNIFICANTLY
ABV NORMAL LEVELS AGAIN FOR THE EARLY PART OF THE FCST PERIOD.
THEY WL DROP BACK CLOSER TO NORMAL BY NEXT WEEKEND...BUT UNLESS
ERN TROF GETS A LOT DEEPER THAN NOW EXPECTED...IT/S HARD TO SEE
THEM GOING BLO NORMAL. THE FCST AREA WL PROBABLY HAVE A COUPLE LGT
PCPN EVENTS...WITH AMNTS PROBABLY ENDING UP BLO NORMAL FOR THE
PERIOD AS A WHOLE.
&&
.SHORT TERM...TONIGHT AND MONDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE HIGH
PRESSURE WORKING EASTWARD ACROSS THE NORTHERN MISSISSIPPI VALLEY
EARLY THIS AFTERNOON. LOW STRATO-CU CLOUD DECK IS SLOWLY LIFTING
OFF TO THE NORTHEAST OVER NORTHEAST WISCONSIN...WHILE THE REST OF
THE REGION REMAINS SUNNY. LOOKING UPSTREAM...PRETTY EXPANSIVE CLOUD
SHIELD IS PRESSING EAST ACROSS THE DAKOTAS...JUST AHEAD OF A
DEVELOPING SURFACE WARM FRONT. AS THE WARM FRONT MOVES EAST ACROSS
THE REGION LATE TONIGHT INTO MONDAY...PRECIP TIMING AND AMOUNTS ARE
THE MAIN FORECAST CONCERNS.
TONIGHT...THE HIGH PRESSURE RIDGE AXIS WILL SLIDE ACROSS THE STATE
DURING THE EVENING HOURS. SHOULD SEE A PERIOD OF CLEAR SKIES AND
LIGHT WINDS THAT WOULD ALLOW TEMPS TO TAKE A TUMBLE. WENT ON THE
COLD SIDE OF GUIDANCE FOR THIS REASON...AS IT USUALLY DOESNT TAKE
MUCH TIME FOR TEMPS TO FALL 20 DEGREES...ESPECIALLY OVER
NORTH-CENTRAL WISCONSIN. THEREAFTER...A 850MB WARM FRONT OVER THE
NORTHERN PLAINS WILL SHIFT EAST INTO SOUTHWEST WISCONSIN AFTER
MIDNIGHT. MODELS HAVE A VARIETY OF ARRIVAL TIMINGS OF THE LIGHT
SNOW AS IT SPREADS SE ALONG THE FRONT INTO CENTRAL WISCONSIN LATE.
DONT REALLY HAVE A GOOD FEEL IF THE FASTER PACE OF THE GFS COMPARED
TO THE NAM IS LIKELY TO BE CORRECT. SO WENT MIDDLE OF THE ROAD FOR
POPS/QPF WHICH PLACES LIKELY POPS OVER NORTH-CENTRAL AND CENTRAL
WISCONSIN. PERHAPS CENTRAL WISCONSIN COULD SEE A QUICK HALF INCH OF
FLUFF BY 12Z. TEMPS SHOULD REBOUND ONCE THE CLOUDS ROLL IN...SO
MIDNIGHT LOWS WILL CREEP BACK UP THROUGH THE OVERNIGHT.
MONDAY...THE WARM FRONT WILL CONTINUE TO MOVE EAST ACROSS THE REGION
ON MONDAY. WILL SEE THE MOST WIDESPREAD SNOW DURING THE MORNING
HOURS WHEN A DECENT BAND OF MID-LEVEL FGEN MOVES OVERHEAD. MOST
PLACES WILL SEE 1-2 INCHES OF SNOW. THE PRIMARY UNCERTAINTY OF THE
EVENT WILL BE THE PTYPE ON THE BACK EDGE OF THE PRECIPITATION SHIELD
WHEN MOISTURE FALLS BELOW -10C...WHICH INCREASES THE PROBABILITY OF
THE ABSENCE OF ICE CRYSTALS IN THE CLOUD. WITH CLOUD COVER AND
PRECIP HOLDING BACK SURFACE TEMPS...THINK THERE COULD BE A RIBBON OF
FREEZING DRIZZLE...MAINLY OVER CENTRAL AND EAST-CENTRAL WISCONSIN ON
THE BACK EDGE. BUT DONT THINK IT WILL POSE A HAZARD AS THE FRONT IS
RELATIVELY FAST MOVING AND SHARP...AS OPPOSED TO A LONG DURATION
OVER-RUNNING EVENT. TEMPS MAY REACH ABOVE FREEZING OVER CENTRAL AND
E-C WISCONSIN AS THE PRECIP ENDS AND CLOUDS ERODE HERE FIRST LATE IN
THE AFTERNOON.
.LONG TERM...MON NGT THROUGH NEXT SUN. THE MESO WRF RUNS FM NCEP
SUGGESTED SOME LGT PCPN COULD STILL LINGER IN THE THE NE EARLY MON
NGT...BUT WITH LITTLE SUPPORT FM ANY OF THE OTHER MODELS STUCK
WITH A DRY FCST. MILD SLY FLOW WL PREVENT MUCH DROP IN TEMPS...SO
BUILT 3 HOURLY TEMP GRIDS FROM A ROBUST BLEND OF GUID PRODUCTS AND
THEN GENERATED MIN GRID FROM THAT.
TUE WAS THE MOST CHALLENGING DAY OF THE FCST PERIOD. WK CYCLONE WL
BE TRACKING EWD ALONG THE U.S. CANADIAN BORDER TOWARD LAKE
SUPERIOR...WITH FCST AREA BASICALLY IN THE WARM SECTOR. OVERALL...
FORCING FOR PCPN WEAK. BUT SOME QG FORCING FM UPR SHRTWV COULD
GENERATE SOME LGT PCPN ACRS THE NW PART OF THE FCST AREA DURING
THE AFTN. CONTD SLGT CHC OF RA/SN TO ACCOUNT FOR THAT. MAIN
QUESTION HOWEVER IS THE CLDS AND THEIR IMPACT ON TEMPS. IT COULD
BE A VERY MILD DAY IF WE CAN ESCAPE HAVING ST FORM ACRS THE AREA.
IF THE ST DOES FORM...IT WL LIMIT TEMPS AND DAMP SLY FLOW WL
PROBABLY MAKE IT SEEM COLDER THAN IT IS. STUCK WITH MAX TEMPS FM
PREV FCST WHICH WERE GENERALLY BLO WHAT BEST PERFORMING GUID WOULD
SUGGEST FOR HIGH TEMPS. INCOMING DWPTS IN THE LOWER TO MIDDLE 30S
MARGINAL FOR ST FORMATION...AND DIDN/T WANT TO TAKE TEMPS BEYOND
WHAT WE HAD GOING WITHOUT HAVING MORE CONFIDENCE THAT WE WOULDN/T
GET STUCK WITH LOW CLDS.
QUIET WX THEN EXPECTED TUE NGT AND WED AS THE CYCLONE PASSES OFF
TO THE E OF THE RGN.
&&
.AVIATION...HIGH PRESSURE WILL MOVE AND DRIFT OVER THE AREA THROUGH
THIS EVENING. AS THE HIGH APPROACHES...MVFR CLOUD DECK OVER
NORTHERN AND NORTHEAST WISCONSIN WILL LIFT OFF TO THE NORTHEAST THIS
AFTERNOON LEAVING VFR CONDITIONS IN ITS WAKE. VFR CONDITIONS THIS
EVENING BEFORE CLOUDS WILL BE ON THE INCREASE AND LOWERING AHEAD OF
A WARM FRONT. LIGHT SNOW IS EXPECTED TO DEVELOP AND EXPAND ALONG
THE FRONT LATE TONIGHT INTO TOMORROW MORNING ACROSS THE REGION.
THOUGH MODELS GENERALLY AGREE WITH THE SNOW AMOUNTS...THEY DIFFER IN
REGARDS TO THE ARRIVAL OF THE SNOW. TRIED TO PLAY THE MIDDLE OF THE
ROAD...WHICH BRINGS THE SNOW INTO CENTRAL WISCONSIN LATE TONIGHT AND
INTO EASTERN WISCONSIN TOMORROW MORNING. CIGS AND VSBYS SHOULD
EASILY FALL TO IFR LEVELS IN THE SNOW...AND PROBABLY LIFR OVER
CENTRAL AND NORTHERN WISCONSIN. SOME PATCHY FREEZING DRIZZLE
POSSIBLE ON THE BACKSIDE OF THE SNOW OVER CENTRAL WISCONSIN BY
MIDDAY.
MPC
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MPC/SKOWRONSKI