Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/02/13
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
204 AM MST THU JAN 31 2013
.UPDATE...
ISSUED AT 201 AM MST THU JAN 31 2013
AS OF 2 AM...RADAR AND WEBCAMS CONTINUE TO SHOW SNOW BANDS
PERSISTING OVER GLENWOOD SPRINGS AND THROUGH GLENWOOD CANYON.
LATEST HRRR AND RAP SHOW SNOW CONTINUING THROUGH 15Z WITH SNOW
RAPIDLY DROPPING OFF AFTERWARDS. THIS CORRESPONDS WELL WITH TIME
HEIGHTS OVER GLENWOOD CANYON SHOWING DEEP SATURATED LAYER IN THE
DENDRITIC GROWTH ZONE WITH DECENT UPWARD MOTION PERSISTING THROUGH
15Z BEFORE THE PROFILE DRIES OUT. THEREFORE...EXTENDED THE WINTER
WEATHER ADVISORY FOR COZ008 THROUGH 15Z THIS MORNING.
UPDATE ISSUED AT 1130 PM MST WED JAN 30 2013
BASED ON RADAR AND SATELLITE OBSERVATIONS...THE PERSISTENT SNOW
BANDS THAT BROUGHT SNOW TO THE I-70 CORRIDOR HAVE SHIFTED EASTWARD
WITH CONDITIONS IMPROVING FROM RIFLE TO SILT BASED ON OBSERVATIONS
AND WEBCAMS. THIS IS CONSISTENT WITH THE LATEST RAP DATA SHOWING
LITTLE IF ANY ADDITIONAL ACCUMULATIONS HERE. THEREFORE CANCELLED
THE WINTER WEATHER ADVISORY FOR COZ007. WEBCAMS AND RADAR STILL
SHOW SNOW BANDS STREAMING ACROSS THE FLATTOPS...THE I-70 CORRIDOR
FROM GLENWOOD SPRINGS TO VAIL PASS...AND STEAMBOAT. REMAINING
HIGHLITES LOOK ON TRACK.
UPDATE ISSUED AT 536 PM MST WED JAN 30 2013
PERSISTENT SNOW OVER THE I-70 CORRIDOR WEST OF EAGLE AND EAST OF
PALISADE HAD ALREADY BROUGHT 1 TO 2 INCHES OF SNOW TO THESE AREAS
EARLY THIS EVENING. LATEST NAM12 AND RAP13 DATA INDICATED THIS
PERSISTENT BAND OF SNOW COULD LAST THROUGH THE EVENING BRINGING
FROM 2 TO 5 INCHES OF BY EARLY MORNING. THEREFORE...A WINTER
WEATHER ADVISORY HAS BEEN ISSUED ZONES 7 AND 8. AREAS IN ZONE 8
ARE NOT INCLUDED IN THIS ADVISORY.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 302 PM MST WED JAN 30 2013
SNOW AND WIND IMPACTING THE NERN PART OF THE FORECAST AREA TODAY.
CLASSIC OROGRAPHIC SNOW IN NORTHWEST FLOW AS PACIFIC MOISTURE
AND STRONG JET TARGETS THE PARK/GORE RANGES AND THE FLAT TOP
MOUNTAINS. MT WERNER SENSORS SHOW WIND OF 25 MPH BUT GUSTS TO
AROUND 40 MPH. GIVEN LOW SNOW TO LIQUID RATIO VALUES...WEB CAMS SHOWING
POOR VISIBILITY OVER THE MOUNTAIN PASSES. SNOTEL SITES SHOWING 6
HOUR QPF GENERALLY RANGING FROM /0.20/ TO /0.50/ INCHES...BUT THIS
MAY EQUATE TO 5 TO 13 INCHES OF SNOW IF LIQUID TO WATER RATIO IS
AROUND 25:1 OR HIGHER. THE HEAVIEST SNOW APPEARS CONFINED ABOVE
8500 FEET...OBSERVATIONS FROM THE PUBLIC AND SPOTTER REPORTS
SUGGEST ONLY LIGHT SNOW IN THE MOUNTAIN VALLEYS (FROM MARBLE AND
ASPEN).
MODEL DATA KEEPS MOISTURE STREAM AND OROGRAPHIC SNOW ONGOING
THROUGH THE NIGHT...BUT GRADUALLY TAPERS OFF ON THURSDAY. GRADIENT FLOW
DOES WEAKEN ON THURSDAY WITH MOISTURE STREAM SOMEWHAT WEAKER...THEREFORE
EXPECT SNOWFALL RATES TO DIMINISH ON THURSDAY. NO CHANGES TO THE
CURRENT WINTER STORM WARNINGS AS ACCUMULATING SNOWFALL COMBINED
WITH WIND WILL PERSIST INTO THURSDAY. IN ADDITION...AN EMBEDDED
DISTURBANCE IN NORTHWEST FLOW RACES ACROSS THE NRN DIVIDE MOUNTAINS
LATE THURSDAY AFTERNOON. ONCE THIS SHORT WAVE CROSSES THE
DIVIDE...EXPECT SNOW AND WIND TO TAPER OFF CONSIDERABLY.
FOR THE REMAINDER OF THE FORECAST AREA...MUCH OF EASTERN UTAH AND
EXTREME WRN COLORADO WILL BE DRY. EXTENSIVE CLOUD COVER THAT
COVERS MUCH OF THE REGION TODAY WILL GRADUALLY ERODE AWAY. MORE
SUN EXPECTED ON THURSDAY ACROSS THE SWRN HALF OF THE FORECAST
AREA. WITH LESS CLOUD COVER... EXPECT OVERNIGHT TEMPS ON FRIDAY
MORNING TO BE THE COLDEST OF THE WEEK FOR THE NRN AND CENTRAL
VALLEYS.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 302 PM MST WED JAN 30 2013
A WAVE IN NW FLOW WILL CLIP NW CO FRI AS IT MOVES INTO THE PLAINS.
THE GFS/ECMWF/CANADIAN MODELS IN GENERAL AGREEMENT HERE AND HAVE
BOOSTED POPS FOR THE ELKHEAD AND PARK RANGES BASED ON THIS. A PERIOD
OF Q-FORCING ALOFT WITH WARM ADVECTIVE UPLIFT AT MTN TOP LEVEL AND
WITH W-NW OROGRAPHICS SHOULD RESULT IN SOME AREAS OF SNOW FROM ABOUT
MIDDAY FRI INTO FRI EVENING.
THIS WEEKEND LOOKS DRY AS THE WEST COAST RIDGE SLIDES OVER THE
FORECAST AREA. A SMALL CLOSED LOW CURRENTLY DEVELOPING OFF THE CA
COAST IS FORECAST TO SHEAR INLAND AND WEAKEN WHILE A LARGER PACIFIC
TROUGH SPLITS AS IT APPROACHES THE COAST. THIS MORNING/S MODELS WERE
IN GENERAL AGREEMENT WITH TAKING THE SOUTHERN PORTION OF THE SPLIT
AND FORMING A CUT-OFF LOW WELL OFF THE CA COAST...WHILE THE NORTHERN
SPLIT BRUSHES OUR FORECAST ABOUT SUNDAY. NEITHER THE GFS NOR ECMWF
SHOW MUCH CHANCE OF SIGNIFICANT PRECIPITATION THOUGH FROM THE
NORTHERN WAVE THOUGH.
GFS HAS BEEN INCONSISTENT HANDLING THE SOUTHERN SPLIT CUT-OFF
LOW...ALTERNATING BETWEEN BRINGING TO ABOUT THE 4 CORNERS BY TUE AND
KEEPING IT OFFSHORE INLINE WITH THE MORE CONSISTENT ECMWF. FOLLOWING
MORE THE PREFERRED ECMWF WOULD RESULT IN GENERAL RIDGING OVER ERN
UT/WRN CO EARLY NEXT WEEK AND A MINIMAL CHANCE OF PRECIP. BUT BOTH
THE GFS AND ECMWF SHOW A DECENT TROUGH APPROACHING THE PACIFIC NW
COASTLINE ON WEDNESDAY...FOR POTENTIALLY UNSETTLED WEATHER LATE NEXT
WEEK.
TEMPERATURES ARE EXPECTED TO GRADUALLY MODERATE THIS PERIOD ALTHOUGH
TEMPS WILL STILL BE A BIT OF A CHALLENGE IN MANY VALLEYS. SNOW
COVER WILL KEEP TEMPS IN THE EASTERN UINTA BASIN LAGGING THE MOST
BEHIND...HOWEVER...WHERE AN INVERSION SHOULD BE SLOW TO ERODE. INVERSIONS
WILL NOT BE A STRONG FOR THE GRAND VALLEY WHERE SNOW COVER IS
DIMINISHING IN AREAL EXTENT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1015 PM MST WED JAN 30 2013
A PERSISTENT MOIST NORTHWEST FLOW WILL CONTINUE TO DELIVER SNOW TO
THE NORTHERN AND CENTRAL MOUNTAINS AND ADJACENT VALLEYS DURING THE
REMAINDER OF THE NIGHT. AS A RESULT...EXPECT KSBS AND KASE TO HAVE
PERSISTENT MVFR CIGS AND VSBY WITH OCCASIONAL IFR CONDITIONS DURING
MUCH OF THE REMAINDER OF THE NIGHT WITH SURROUNDING MOUNTAINS
OBSCURED IN SNOW. KRIL...KGWS...AND KGUC WILL HAVE OCCASIONAL
MVFR CIGS AND VSBY IN SNOW SHOWERS THROUGH 12Z THURSDAY.
MODELS CONTINUE TO GENERATE MOUNTAIN SNOW OVER THE NORTHERN AND
CENTRAL MOUNTAINS THURSDAY THROUGH MIDNIGHT...THOUGH LIGHTER IN
INTENSITY AND LESS EXTENSIVE. ADJACENT TERMINALS ARE UNLIKELY TO
DROP BELOW VFR CONDITIONS THURSDAY.
AREAS WEST OF A KPSO TO KCAG LINE WILL HAVE VFR CONDITIONS THROUGH
THE NEXT 24 HOURS.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 8 AM MST THIS MORNING FOR COZ008.
WINTER STORM WARNING UNTIL 6 PM MST THIS EVENING FOR COZ004-005-
010-013.
UT...NONE.
&&
$$
UPDATE...MDA
SHORT TERM...PF
LONG TERM...JAD
AVIATION...NL
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1130 PM MST WED JAN 30 2013
.UPDATE...
ISSUED AT 1130 PM MST WED JAN 30 2013
BASED ON RADAR AND SATELLITE OBSERVATIONS...THE PERSISTENT SNOW
BANDS THAT BROUGHT SNOW TO THE I-70 CORRIDOR HAVE SHIFTED EASTWARD
WITH CONDITIONS IMPROVING FROM RIFLE TO SILT BASED ON OBSERVATIONS
AND WEBCAMS. THIS IS CONSISTENT WITH THE LATEST RAP DATA SHOWING
LITTLE IF ANY ADDITIONAL ACCUMULATIONS HERE. THEREFORE CANCELLED
THE WINTER WEATHER ADVISORY FOR COZ007. WEBCAMS AND RADAR STILL
SHOW SNOW BANDS STREAMING ACROSS THE FLATTOPS...THE I-70 CORRIDOR
FROM GLENWOOD SPRINGS TO VAIL PASS...AND STEAMBOAT. REMAINING
HIGHLITES LOOK ON TRACK.
UPDATE ISSUED AT 536 PM MST WED JAN 30 2013
PERSISTENT SNOW OVER THE I-70 CORRIDOR WEST OF EAGLE AND EAST OF
PALISADE HAD ALREADY BROUGHT 1 TO 2 INCHES OF SNOW TO THESE AREAS
EARLY THIS EVENING. LATEST NAM12 AND RAP13 DATA INDICATED THIS
PERSISTENT BAND OF SNOW COULD LAST THROUGH THE EVENING BRINGING
FROM 2 TO 5 INCHES OF BY EARLY MORNING. THEREFORE...A WINTER
WEATHER ADVISORY HAS BEEN ISSUED ZONES 7 AND 8. AREAS IN ZONE 8
ARE NOT INCLUDED IN THIS ADVISORY.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 302 PM MST WED JAN 30 2013
SNOW AND WIND IMPACTING THE NERN PART OF THE FORECAST AREA TODAY.
CLASSIC OROGRAPHIC SNOW IN NORTHWEST FLOW AS PACIFIC MOISTURE
AND STRONG JET TARGETS THE PARK/GORE RANGES AND THE FLAT TOP
MOUNTAINS. MT WERNER SENSORS SHOW WIND OF 25 MPH BUT GUSTS TO
AROUND 40 MPH. GIVEN LOW SNOW TO LIQUID RATIO VALUES...WEB CAMS SHOWING
POOR VISIBILITY OVER THE MOUNTAIN PASSES. SNOTEL SITES SHOWING 6
HOUR QPF GENERALLY RANGING FROM /0.20/ TO /0.50/ INCHES...BUT THIS
MAY EQUATE TO 5 TO 13 INCHES OF SNOW IF LIQUID TO WATER RATIO IS
AROUND 25:1 OR HIGHER. THE HEAVIEST SNOW APPEARS CONFINED ABOVE
8500 FEET...OBSERVATIONS FROM THE PUBLIC AND SPOTTER REPORTS
SUGGEST ONLY LIGHT SNOW IN THE MOUNTAIN VALLEYS (FROM MARBLE AND
ASPEN).
MODEL DATA KEEPS MOISTURE STREAM AND OROGRAPHIC SNOW ONGOING
THROUGH THE NIGHT...BUT GRADUALLY TAPERS OFF ON THURSDAY. GRADIENT FLOW
DOES WEAKEN ON THURSDAY WITH MOISTURE STREAM SOMEWHAT WEAKER...THEREFORE
EXPECT SNOWFALL RATES TO DIMINISH ON THURSDAY. NO CHANGES TO THE
CURRENT WINTER STORM WARNINGS AS ACCUMULATING SNOWFALL COMBINED
WITH WIND WILL PERSIST INTO THURSDAY. IN ADDITION...AN EMBEDDED
DISTURBANCE IN NORTHWEST FLOW RACES ACROSS THE NRN DIVIDE MOUNTAINS
LATE THURSDAY AFTERNOON. ONCE THIS SHORT WAVE CROSSES THE
DIVIDE...EXPECT SNOW AND WIND TO TAPER OFF CONSIDERABLY.
FOR THE REMAINDER OF THE FORECAST AREA...MUCH OF EASTERN UTAH AND
EXTREME WRN COLORADO WILL BE DRY. EXTENSIVE CLOUD COVER THAT
COVERS MUCH OF THE REGION TODAY WILL GRADUALLY ERODE AWAY. MORE
SUN EXPECTED ON THURSDAY ACROSS THE SWRN HALF OF THE FORECAST
AREA. WITH LESS CLOUD COVER... EXPECT OVERNIGHT TEMPS ON FRIDAY
MORNING TO BE THE COLDEST OF THE WEEK FOR THE NRN AND CENTRAL
VALLEYS.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 302 PM MST WED JAN 30 2013
A WAVE IN NW FLOW WILL CLIP NW CO FRI AS IT MOVES INTO THE PLAINS.
THE GFS/ECMWF/CANADIAN MODELS IN GENERAL AGREEMENT HERE AND HAVE
BOOSTED POPS FOR THE ELKHEAD AND PARK RANGES BASED ON THIS. A PERIOD
OF Q-FORCING ALOFT WITH WARM ADVECTIVE UPLIFT AT MTN TOP LEVEL AND
WITH W-NW OROGRAPHICS SHOULD RESULT IN SOME AREAS OF SNOW FROM ABOUT
MIDDAY FRI INTO FRI EVENING.
THIS WEEKEND LOOKS DRY AS THE WEST COAST RIDGE SLIDES OVER THE
FORECAST AREA. A SMALL CLOSED LOW CURRENTLY DEVELOPING OFF THE CA
COAST IS FORECAST TO SHEAR INLAND AND WEAKEN WHILE A LARGER PACIFIC
TROUGH SPLITS AS IT APPROACHES THE COAST. THIS MORNING/S MODELS WERE
IN GENERAL AGREEMENT WITH TAKING THE SOUTHERN PORTION OF THE SPLIT
AND FORMING A CUT-OFF LOW WELL OFF THE CA COAST...WHILE THE NORTHERN
SPLIT BRUSHES OUR FORECAST ABOUT SUNDAY. NEITHER THE GFS NOR ECMWF
SHOW MUCH CHANCE OF SIGNIFICANT PRECIPITATION THOUGH FROM THE
NORTHERN WAVE THOUGH.
GFS HAS BEEN INCONSISTENT HANDLING THE SOUTHERN SPLIT CUT-OFF
LOW...ALTERNATING BETWEEN BRINGING TO ABOUT THE 4 CORNERS BY TUE AND
KEEPING IT OFFSHORE INLINE WITH THE MORE CONSISTENT ECMWF. FOLLOWING
MORE THE PREFERRED ECMWF WOULD RESULT IN GENERAL RIDGING OVER ERN
UT/WRN CO EARLY NEXT WEEK AND A MINIMAL CHANCE OF PRECIP. BUT BOTH
THE GFS AND ECMWF SHOW A DECENT TROUGH APPROACHING THE PACIFIC NW
COASTLINE ON WEDNESDAY...FOR POTENTIALLY UNSETTLED WEATHER LATE NEXT
WEEK.
TEMPERATURES ARE EXPECTED TO GRADUALLY MODERATE THIS PERIOD ALTHOUGH
TEMPS WILL STILL BE A BIT OF A CHALLENGE IN MANY VALLEYS. SNOW
COVER WILL KEEP TEMPS IN THE EASTERN UINTA BASIN LAGGING THE MOST
BEHIND...HOWEVER...WHERE AN INVERSION SHOULD BE SLOW TO ERODE. INVERSIONS
WILL NOT BE A STRONG FOR THE GRAND VALLEY WHERE SNOW COVER IS
DIMINISHING IN AREAL EXTENT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1015 PM MST WED JAN 30 2013
A PERSISTENT MOIST NORTHWEST FLOW WILL CONTINUE TO DELIVER SNOW TO
THE NORTHERN AND CENTRAL MOUNTAINS AND ADJACENT VALLEYS DURING THE
REMAINDER OF THE NIGHT. AS A RESULT...EXPECT KSBS AND KASE TO HAVE
PERSISTENT MVFR CIGS AND VSBY WITH OCCASIONAL IFR CONDITIONS DURING
MUCH OF THE REMAINDER OF THE NIGHT WITH SURROUNDING MOUNTAINS
OBSCURED IN SNOW. KRIL...KGWS...AND KGUC WILL HAVE OCCASIONAL
MVFR CIGS AND VSBY IN SNOW SHOWERS THROUGH 12Z THURSDAY.
MODELS CONTINUE TO GENERATE MOUNTAIN SNOW OVER THE NORTHERN AND
CENTRAL MOUNTAINS THURSDAY THROUGH MIDNIGHT...THOUGH LIGHTER IN
INTENSITY AND LESS EXTENSIVE. ADJACENT TERMINALS ARE UNLIKELY TO
DROP BELOW VFR CONDITIONS THURSDAY.
AREAS WEST OF A KPSO TO KCAG LINE WILL HAVE VFR CONDITIONS THROUGH
THE NEXT 24 HOURS.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 2 AM MST THURSDAY FOR COZ008.
WINTER STORM WARNING UNTIL 6 PM MST THURSDAY FOR COZ004-005-010-
013.
UT...NONE.
&&
$$
UPDATE...MDA
SHORT TERM...PF
LONG TERM...JAD
AVIATION...NL
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1000 PM MST WED JAN 30 2013
.UPDATE...NO CHANGES NEED TO THE CURRENT FORECAST. WINDS CONTINUE
TO BLOW OVER THE MOUNTAINS AND FOOTHILLS WITH GUSTS IN THE 40 TO
60 MPH RANGE...WITH BERTHOUD PASS JUST GUSTING TO 65 MPH. SNOTEL
OBSERVATIONS STILL SHOWING THE OROGRAPHIC SNOW PRODUCTION...WITH
AREAS RECEIVING BETWEEN HALF AN INCH TO UP TO AN INCH AN HOUR WITH
THE HIGHEST AMOUNTS NEAR RABBIT EARS PASS. WINTER STORM WARNING
STILL IN EFFECT UNTIL THURSDAY EVENING. SOME OF THE LATEST MODELS
ARE SHOWING LESS MOISTURE UPSTREAM...SO THE ENDING TIME OF THE
WARNING MAY HAVE TO BE ADJUSTED. HOWEVER...THE WIND WILL CONTINUE
TO BE QUITE STRONG TO CONTRIBUTE TO THE HAZARDOUS WEATHER.
&&
.AVIATION...SOUTHWEST WILL PREVAIL TONIGHT AT DEN AND APA AS
DRAINAGE FLOW DEVELOPS WITH SPEEDS AROUND 12 KTS. WINDS TO REMAIN
WEST TO NORTHWEST AT BJC THROUGH THE EVENING AND OVERNIGHT...WITH
SOME GUSTS TO 40 KTS POSSIBLE AFTER 06Z. ON THURSDAY...WINDS
TO BECOME NORTHWEST AND WEAKEN ACROSS THE AREA AFTER 16Z. SOME
GUSTS TO 25 KTS WILL BE POSSIBLE AT BJC. VFR TO PREVAIL.
&&
.PREV DISCUSSION... /ISSUED 355 PM MST WED JAN 30 2013/
SHORT TERM...STRONG NORTHWEST FLOW ALOFT OVER AREA WITH
OROGRAPHICS CONTINUING ACROSS MOUNTAINS. WEB CAMS INDICATE SNOW
CONTINUING ACROSS MOUNTAINS...THOUGH HAS SHOWN SOME SIGNS OF
DECREASING DURING THE PAST FEW HOURS. STABILITY HAS BEEN
LIMITED...WHICH HAS HINDERED THE HEAVIER SNOW RATES. STILL..WINDS
BEEN QUITE GUSTY ACROSS THE RIDGES...WITH A RECENT GUST TO 71 MPH
ATOP BERTHOUD PASS WHILE OTHER GUSTS WERE MAINLY IN THE 50S. THE
WINDS WERE CREATING AREAS OF BLOWING SNOW ACROSS THE MOUNTAIN
PASSES. GUSTY WINDS ALSO OCCURRING IN AND NEAR FOOTHILLS WITH
GUSTS MAINLY IN THE 40S. ACROSS PLAINS WEAK MESOCYCLONE SLIDING
SOUTH ACROSS MORGAN COUNTY KEEPING GUSTY WINDS FROM SPREADING EAST
ACROSS URBAN CORRIDOR. FLOW ALOFT REMAINS STRONG TONIGHT AND
INCREASES SLIGHTLY AS SHOWN BY RAP CROSS SECTIONS. AIRMASS TO
REMAIN QUITE MOIST ACROSS THE MOUNTAINS ALONG WITH CONTINUED
OROGRAPHICS AND SNOWFALL. STABILITY SHOULD IMPROVE OVERNIGHT...
HELPING WITH SNOWFALL RATES. ADDITIONAL 3 TO 6 INCHES STILL
POSSIBLE ON FAVORED WEST FACING SLOPES WITH LESSER AMOUNTS
ELSEWHERE. MODEL CROSS SECTIONS SHOW WEAK MOUNTAIN WAVE DEVELOPING
OVERNIGHT WHICH WILL HELP TO INCREASE WINDS. GUSTS AROUND 70 MPH
POSSIBLE ALONG THE HIGHER RIDGES...WITH GUSTS UP TO 60 MPH ALONG
THE FOOTHILLS. THE GUSTY WINDS WILL CONTINUE TO CREATE CONSIDERABLE
BLOWING SNOW OVER THE MOUNTAIN PASSES WITH POSSIBLE WHITE OUT
CONDITIONS ABOVE TIMBERLINE. ACROSS PLAINS...WINDS TO BE A BIT
GUSTY NEAR THE FOOTHILLS AND WYOMING BORDER WITH LESS WIND
ELSEWHERE. MODELS CONTINUE TO SHOW AN AREA OF LIGHT SNOW
DEVELOPING ALONG THE WYOMING BORDER TONIGHT IN VICINITY OF UPPER
JET. OTHERWISE...DRY CONDITIONS TO PREVAIL. ON THURSDAY...STRONG
NORTHWEST FLOW ALOFT TO CONTINUE THOUGH MODEL CROSS SECTIONS
INDICATE MOISTURE ACROSS MOUNTAINS DECREASING BY THE AFTERNOON AS
STABILITY INCREASES. STILL DECENT OROGRAPHICS IN PLACE FOR MUCH
OF THE DAY ALONG WITH GUSTY WINDS. SHOULD SEE SNOW GRADUALLY
DECREASE DURING THE DAY THOUGH THERE WILL STILL BE QUITE A BIT OF
BLOWING SNOW. WILL MAINTAIN THE WARNING THROUGH THE DAY THOUGH
ADDITIONAL SNOWFALL SHOULD BE LIGHT. WINDS TO BE A BIT GUSTY IN
AND NEAR THE FOOTHILLS AS A WEAK SURFACE TROUGH IS EXPECTED TO
DEVELOP. FURTHER EAST...MODELS CONTINUE TO SHOW A WEAK COLD FRONT
MOVING INTO THE NORTHEAST CORNER. WITH UPPER JET IN VICINITY...
THERE COULD BE A SLIGHT CHANCE OF LIGHT SNOW IN THE FAR NEAR THE
WYOMING BORDER. OTHERWISE DRY CONDITIONS WILL PREVAIL.
LONG TERM...A RATHER BENIGN WEEK OF WEATHER IS EXPECTED AFTER THE
SNOW SHOWERS CLEAR OUT OF THE MOUNTAINS THURSDAY NIGHT. ON
THURSDAY EVENING...A FEW SNOW SHOWERS MAY BE LINGERING...BUT THEY
WILL BE ON THE DECREASE AS SUBSIDENCE OVER THE STATE INCREASES.
DRY...NORTHWESTERLY FLOW ALOFT IS FORECAST TO CONTINUE THROUGH
THE PERIOD AS AN UPPER RIDGE REMAINS ANCHORED OFF THE WEST COAST
AND A DEEP TROUGH CONTINUES OVER THE EASTERN UNITED STATES. THE
ECMWF AND GFS ARE IN GOOD AGREEMENT THROUGH THE WEEKEND...BUT AT
THE END THE TWO MODELS HAVE DIFFERENT IDEAS ABOUT A TROUGH THAT
DEVELOPS OFF THE CALIFORNIA COAST. IF A TROUGH DEVELOPS...IT IS
NOT EXPECTED TO MOVE INTO THE CENTRAL ROCKIES UNTIL THE MIDDLE OF
NEXT WEEK. TEMPERATURES SHOULD GRADUALLY MODERATE THROUGH THE
UPCOMING FORECAST PERIOD AS THE NORTHWEST FLOW ALOFT CONTINUES.
AVIATION... WINDS HAVE BECOME LIGHT NORTHEAST AT DEN DUE TO WEAK
MESOCYCLONE OVER MORGAN COUNTY. GUSTY WEST TO NORTHWEST WINDS
CONTINUE AT APA AND BJC. WINDS TO BECOME NORTHWEST AT DEN BY 00Z
AS MESOCYCLONE SHIFTS EAST INTO WASHINGTON COUNTY. AFTER
03Z...WINDS SHOULD SHIFT TO THE SOUTHWEST AT DEN AND APA AS
DRAINAGE FLOW DEVELOPS WITH SPEEDS AROUND 12 KTS. WINDS TO REMAIN
WEST TO NORTHWEST AT BJC THROUGH THE EVENING AND OVERNIGHT...WITH
SOME GUSTS TO 40 KTS POSSIBLE AFTER 06Z. ON THURSDAY...WINDS
TO BECOME NORTHWEST AND WEAKEN ACROSS THE AREA AFTER 16Z. SOME
GUSTS TO 25 KTS WILL BE POSSIBLE AT BJC. VFR TO PREVAIL.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 5 PM MST THURSDAY FOR COZ031-033-034.
&&
$$
SHORT TERM...D-L
LONG TERM....DANKERS
UPDATE/AVIATION...KRIEDERMAN
AREA FORECAST DISCUSSION
NWS ALBANY NY
415 PM EST THU JAN 31 2013
.SYNOPSIS...
S A CANADIAN AIR MASS MOVES INTO THE REGION...
TEMPERATURES WILL BE MUCH COLDER TONIGHT WITH A DIMINISHING WIND.
LAKE EFFECT SNOW SHOWERS WILL CONTINUE TO AFFECT THE WESTERN
ADIRONDACKS AND MOHAWK VALLEY OVERNIGHT. LAKE EFFECT SNOW WILL SHIFT
SOUTH AND WEST OF THE REGION TOMORROW...WITH COLD TEMPERATURES AND
BREEZY CONDITIONS. SEASONABLY CHILLY TEMPERATURES WILL CONTINUE TO
BE IN PLACE OVER THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 415 PM EST...WINDS ARE STARTING TO DIMINISH AS THE PRESSURE
GRADIENT BEGINS TO RELAX. THE PRESSURE COUPLET ASSOCIATED WITH THE
SFC FRONTAL BOUNDARY IS WELL NORTHEAST OF THE REGION ACROSS
ATLANTIC CANADA. STILL...A FEW GUSTS OF 25-40 MPH ARE OCCURRING
LATE THIS AFTN...SO WE WILL LET THE CURRENT HIGH WIND WARNING
EXPIRE AT 6 PM. BY THAT POINT...WINDS WILL STILL BE BREEZY FOR THE
OVERNIGHT HOURS...BUT NOT ENOUGH TO CAUSE DAMAGE.
A BAND OF LAKE EFFECT SNOW IS CURRENTLY ONGOING ACROSS THE WESTERN
ADIRONDACKS. THE LOCAL HIRES WRF MODEL...AS WELL AS THE NAM12 AND
3KM HRRR MODEL...SHOWS THIS BAND TO SHIFT SOUTHWARD DURING THE
OVERNIGHT HOURS. WITH THIS BAND HAVING AN EXCELLENT MULTI-LAKE
CONNECTION ALL THE WAY BACK TO THE WESTERN GREAT LAKES AND STRONG
LOW LEVEL SPEED SHEAR...LOCAL CSTAR RESEARCH WOULD SUGGEST THAT
THIS BAND REACHES WELL INTO OUR AREA. AS A RESULT...HAVE ALSO
INCLUDED A LAKE EFFECT SNOW ADVISORY FOR HAMILTON COUNTY...IN
ADDITION TO THE WSW ALREADY IN EFFECT FOR NRN HERKIMER. SNOW
TOTALS LOOK TO REACH 4-8 INCHES IN NRN HERKIMER AND 3-6 INCHES
ACROSS WESTERN HAMILTON COUNTY.
AS THE BAND SHIFTS SOUTH FOR LATE TONIGHT...IT SHOULD MOVE
QUICKLY. WHILE A QUICK FEW INCHES OF ACCUMULATION IS POSSIBLE
ACROSS THE MOHAWK VALLEY...IT SHOULD MOVE QUICK ENOUGH SOUTHWARD TO
PREVENT ANY MODERATE ACCUMULATION OF SNOW. AS A RESULT...WE WILL
NOT ISSUE ANY LAKE EFFECT ADVISORIES FOR THE MOHAWK VALLEY
AREA...BUT WILL CONTINUE TO MENTION IN OUR HWO STATEMENT.
ELSEWHERE...SOME UPSLOPE SNOW SHOWERS ARE POSSIBLE FOR THE HIGH
TERRAIN OF WESTERN NEW ENGLAND WITH SOME MINOR SNOW ACCUMULATION
POSSIBLE. THE REMAINDER OF THE REGION LOOKS TO BE DRY...ALTHOUGH
AS THE LAKE BAND SHIFTS SOUTHWARD...THE INLAND EXTENT MAY ALLOW
FOR SOME FLAKES TO REACH THE CAPITAL REGION FOR 08Z-12Z. NOT
EXPECTING MUCH ACCUMULATION...BUT IT/S POSSIBLE FOR A COATING OF
SNOW IN THE ALBANY/SCHENECTADY/TROY AREA BY LATE IN THE NIGHT
TOWARDS DAYBREAK.
MIN TEMPS WILL BE MUCH COOLER THAN LAST NIGHT. MINS WILL RANGE
FROM THE SINGLE DIGITS IN THE ADKS TO THE LOW TO MID 20S IN THE
MID HUDSON VALLEY.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
MAINLY DRY AND SEASONABLY COOL WEATHER IS EXPECTED THROUGH THE
SHORT TERM PERIOD.
THE LAKE BAND WILL SHIFT SOUTH AND WEST OF THE CWA BY FRIDAY
MORNING...MAINLY ENDING THE THREAT FOR LAKE EFFECT IN OUR AREA.
THE EXCEPTION MAY BE A FEW HOURS OF SNOW FOR WESTERN SCHOHARIE
COUNTY WITH SOME LIGHT SNOW ACCUMULATION EARLY FRIDAY MORNING
BEFORE THE BAND SHIFTS AWAY FROM THE AREA. MAX TEMPS WILL BE
NOTICEABLY COOLER...WITH TEENS AND 20S ACROSS THE AREA. IN
ADDITION...DAYTIME MIXING WILL ALLOW FOR SOME GUSTY WINDS...SO IT
WILL FEEL EVEN COLDER...WITH SOME GUSTS OF 15-30 MPH POSSIBLE.
WE WILL CONTINUE TO MENTION LOW CHC OR SLIGHT CHC POPS FOR FAR
WESTERN AREAS FOR FRIDAY AFTERNOON...IN CASE UPSLOPE FLOW DOES
ALLOW FOR SOME LIGHT SNOW SHOWERS...BUT ANY ADDITIONAL SNOW
ACCUMULATION LOOKS LIGHT. THE HUDSON VALLEY AREA SHOULD REMAIN
MAINLY DRY.
CHILLY...BUT SEASONABLE TEMPS...ARE EXPECTED FRIDAY NIGHT WITH
TEMPS RANGING FROM A FEW DEGREES BELOW ZERO ACROSS THE ADIRONDACKS
TO THE MID TEENS IN THE HUDSON VALLEY/NW CT.
A WEAK SHORTWAVE WILL PASS TO THE NORTH OF THE REGION ON SATURDAY
INTO SATURDAY NIGHT. THIS MAY ALLOW FOR SOME LIGHT SNOW SHOWERS
ACROSS THE ADIRONDACKS...OTHERWISE IT LOOKS CONTINUED DRY AND
COOL. MAX TEMPS ON SATURDAY WILL MAINLY BE IN THE TEENS AND 20S.
MIN TEMPS SAT NIGHT WILL RANGE FROM THE SINGLE DIGITS UP NORTH TO
NEAR 20 SOUTH.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
MEAN UPPER TROUGH OVER EASTERN NORTH AMERICA THROUGH THE PERIOD...
WITH LITTLE NORTHERN STREAM IMPULSES TRACKING RAPIDLY THROUGH THE
CYCLONIC FLOW. THE TIMING OF THESE SYSTEMS IN SUCH QUICK UPPER FLOW
IS IN QUESTION BUT TIMED THE BETTER CHANCES FOR SNOW IN THE SUNDAY
TIME FRAME AND AGAIN IN THE MONDAY NIGHT TO TUESDAY TIME FRAME.
THESE SYSTEMS COULD TRACK FAR ENOUGH EAST AND SOUTH OF OUR REGION
THAT THERE COLD BE LITTLE TO NO SNOW IN MUCH OF THE FORECAST AREA...
SO INDICATING BEST CHANCES IN THE MID HUDSON VALLEY...NW CT AND THE
BERKSHIRES. ANY PRECIPITATION WOULD BE RELATIVELY LIGHT IN BOTH
EVENTS...AND SHOULD NOT REQUIRE SNOW HEADLINES SINCE THE STORMS
SHOULD BE STARVED FOR MOISTURE UNTIL THEY RAPIDLY HEAD OFFSHORE AND
WELL EAST OF OUR REGION.
OUTSIDE OF THESE POTENTIAL 2 SMALL EVENTS...SOME PERSISTENT LAKE
EFFECT SNOW BANDS COULD EXTEND INTO THE SOUTHERN ADIRONDACKS...
WESTERN MOHAWK VALLEY...SCHOHARIE VALLEY AND EASTERN CATSKILLS.
SO...PERIODS OF CLOUDS THROUGH THE PERIOD WITH TEMPERATURES AROUND
NORMAL SUNDAY...A LITTLE BELOW NORMAL MONDAY THROUGH WEDNESDAY AND
BACK TO AROUND NORMAL THURSDAY.
&&
.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
THE MAIN PROBLEM THIS AFTERNOON WILL BE THE CONTINUATION STRONG
WINDS OUT OF THE WEST TO NORTHWEST...WHICH WILL OCCASIONALLY GUST
NEAR 40 KT (OR BETTER) ESPECIALLY THIS AFTERNOON AT KALB. A HIGH
WIND WARNING REMAINS IN EFFECT.
THE WIND WILL ABATE SOMEWHAT TONIGHT BUT STILL CONTINUE TO
OCCASIONALLY GUST 20 TO 25 KT OUT OF THE WEST TO NORTHWEST...LESS
GUSTY AFTER ABOUT 02Z. CONDITIONS SHOULD REMAIN MAINLY VFR BUT CIGS
COULD OCCASIONALLY DROP INTO THE HIGH MVFR RANGE AT KPSF DURING THE
NIGHT.
WEST TO NORTHWEST WINDS SHOULD BECOME GUSTY AGAIN TOMORROW AFTER
ABOUT 16Z. IF THE CEILING AT KPSF DROPS TO MVFR TONIGHT...IT SHOULD
BE BACK TO VFR AFTER 12Z.
OUTLOOK...
FRI-MON...MAINLY VFR. CHC SUB-VFR -SHSN.
&&
.HYDROLOGY...
SNOWMELT FROM THE RECENT WARMER TEMPERATURES AND RAINFALL FROM
EARLY THIS MORNING COMBINED FOR SOME RUNOFF ACROSS THE REGION THIS
MORNING. HOWEVER...THIS WAS NOT ENOUGH TO CAUSE FLOODING ACROSS
OUR AREA. WITH TEMPERATURES COOLING BELOW FREEZING ACROSS THE
ENTIRE AREA THIS EVENING...ANY SNOWMELT SHOULD END...AND RIVERS
WILL START TO RECEDE.
BECAUSE OF THE WARM TEMPERATURES AND RAINFALL...SOME ICE BROKE UP
IN AREA RIVERS AND STREAMS. THIS CAUSED SOME MINOR FLOODING ON THE
EAST CANADA CREEK IN DOLGEVILLE AND ALONG THE HOOSIC RIVER NEAR
BUSKIRK. THE THREAT FOR ICE JAMS SHOULD DECREASE THIS EVENING
WITH THE COOLER TEMPERATURES...AND ALTHOUGH ANY ICE THAT BROKE UP
MAY BEGIN TO REFREEZE IN PLACE...LOWERING FLOWS SHOULD PREVENT ANY
FLOODING FROM OCCURRING.
THE NEXT SEVERAL DAYS WILL BE FAIRLY DRY...AND ANY LIGHT
PRECIPITATION WILL BE IN THE FORM OF SNOW. THIS SHOULD ALLOW
RIVERS AND STREAMS TO SLOWLY RECEDE INTO EARLY NEXT WEEK.
FOR SPECIFIC RIVER AND LAKE FORECASTS...PLEASE VISIT THE ADVANCED
HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...HIGH WIND WARNING UNTIL 6 PM EST THIS EVENING FOR CTZ001-013.
NY...HIGH WIND WARNING UNTIL 6 PM EST THIS EVENING FOR NYZ032-033-
038>043-047>054-058>061-063>066-082>084.
LAKE EFFECT SNOW ADVISORY UNTIL 6 AM EST FRIDAY FOR NYZ032-033.
MA...HIGH WIND WARNING UNTIL 6 PM EST THIS EVENING FOR MAZ001-025.
VT...HIGH WIND WARNING UNTIL 6 PM EST THIS EVENING FOR VTZ013>015.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS
SHORT TERM...FRUGIS
LONG TERM...NAS
AVIATION...NAS
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1006 AM EST Thu Jan 31 2013
...Possible short duration light freeze tonight...
...Another freeze possible Friday night...
.NEAR TERM [Through Tonight]...
Updated at 945 am EST-
The 12 UTC regional surface analysis showed the cold front that
moved through our forecast area last night was over South FL,
while a 1024 mb high pressure ridge (centered over LA) was
building east along the Gulf Coast. Vapor imagery and upper air
data showed a broad trough over much of the eastern CONUS, with
plenty of dry air throughout the atmospheric column. Based on our
12 UTC KTAE sounding and the latest NWP guidance, we expect high
temperatures today will be in the mid to upper 50s.
With the ridge building in quickly, surface winds will likely
become calm shortly after sunset. This will allow for rapid
cooling, and a light freeze is possible at our normally coldest
sites (inland, relatively "open" areas away from cities). Even for
those areas that don`t quite reach freezing, frost will be
possible. The one limiting factor (which could prevent a deeper
freeze) will be the potential for surface winds to increase
slightly shortly before dawn, ahead of a dry cold front just to
the north.
&&
.SHORT TERM [Friday Through Saturday]...
High Temps both Friday and Saturday will be slightly below
climatology and generally range from the upper 50s NW to the mid
60s SE. On Friday night, however, we could see one of the coldest
nights of the entire Winter Season thus far, as the Sfc Ridge
behind the Dry Cold Front will be positioned right overhead of the
CWA. This will allow for nearly ideal conditions for Radiational
Cooling with clear skies and near calm winds. Low Temps could
bottom out in the middle 20s over much of the interior, which will
result in at least a long duration light freeze, and the
possibility of the first Hard Freeze of the season. Therefore, all
outdoor interests and those with sensitive vegetation should keep
abreast of the latest information from the National Weather
Service in Tallahassee.
&&
.Long Term [Sunday night through Thursday]...
Undated at 945 am EST-
Mostly zonal flow will dominate on the southern periphery of
broad eastern U.S. troughing through the period. A weak impulse
will pass overhead late on Monday, however, dry air will limit the
impacts to passing high clouds with no chance for rain. A slightly
stronger mid/upper wave will approach towards the end of the
period. At this time, little to no rain is expected with this
disturbance either. Overall, the period will be dominated by dry
conditions and near or slightly above average temperatures.
&&
.AVIATION [through 18 UTC Friday]...
Undated at 945 am EST-
Unlimited visibility and ceilings will prevail through the period.
Winds will be NW 5 to 10 KT this afternoon, light overnight, then
NW 5 to 10 KT again Friday. The only possible visibility
restriction could be caused by any large fire occurring near a
terminal, but currently we don`t see any "hot spots" on
satellite/radar imagery that would concern us.
&&
.MARINE...
Updated at 945 am EST-
Winds & seas were still solidly at advisory levels, but the latest
NWP guidance (including high resolution RAP and local 4km WRF) is
unanimous in having the winds fall below advisory criteria by
early afternoon. Thereafter, light to moderate offshore winds and
seas will dominate through Friday, with a period of cautionary
northeasterly winds expected on Friday night. Then, light winds
and low seas are anticipated for the upcoming weekend and
beginning of next week.
&&
.FIRE WEATHER...
Very dry conditions will overspread the region today and continue
into the weekend. Red flag conditions look like a near certainty
across much of North Florida today and possibly again on Friday.
Though RH values will be below 25 percent in Alabama and Georgia
today and on Friday, it appears as though the other required
criteria (winds and/or fuel moisture) will not be met. More moist
conditions will return by Sunday, putting an end to any red flag
concerns.
&&
.HYDROLOGY...
Despite a fairly widespread rainfall across the region on Wednesday
(with most areas receiving between 0.50" and 2" of rain, with the
highest amounts well to the N and W), only minor rises have been
observed on area rivers thus far. The only exception appears to be
the Choctawhatchee River, where the river may rise to near action
stage at Caryville during the next few days.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 58 32 63 25 63 / 0 0 0 0 0
Panama City 57 42 61 36 61 / 0 0 0 0 0
Dothan 56 36 57 28 60 / 0 0 0 0 0
Albany 56 32 57 26 60 / 0 0 0 0 0
Valdosta 57 32 61 25 62 / 0 0 0 0 0
Cross City 60 30 66 26 65 / 0 0 0 0 0
Apalachicola 57 40 62 35 59 / 0 0 0 0 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...FREEZE WATCH from late tonight through Friday morning for
Calhoun-Central Walton-Coastal Dixie-Coastal Taylor-
Gadsden-Holmes-Inland Bay-Inland Dixie-Inland Franklin-
Inland Gulf-Inland Jefferson-Inland Taylor-Inland Wakulla-
Inland Walton-Jackson-Lafayette-Leon-Liberty-Madison-
Washington.
RED FLAG WARNING until 7 PM EST /6 PM CST/ this evening for
Calhoun-Central Walton-Coastal Bay-Coastal Dixie-Coastal
Jefferson-Coastal Taylor-Coastal Wakulla-Gadsden-Holmes-
Inland Bay-Inland Dixie-Inland Jefferson-Inland Taylor-
Inland Wakulla-Inland Walton-Jackson-Lafayette-Leon-
Liberty-Madison-South Walton-Washington.
FIRE WEATHER WATCH from Friday afternoon through Friday
evening for Calhoun-Central Walton-Coastal Bay-Coastal
Dixie-Coastal Franklin-Coastal Gulf-Coastal Jefferson-
Coastal Taylor-Coastal Wakulla-Gadsden-Holmes-Inland Bay-
Inland Dixie-Inland Franklin-Inland Gulf-Inland Jefferson-
Inland Taylor-Inland Wakulla-Inland Walton-Jackson-
Lafayette-Leon-Liberty-Madison-South Walton-Washington.
GA...FREEZE WATCH from late tonight through Friday morning for
Baker-Ben Hill-Berrien-Brooks-Calhoun-Clay-Colquitt-Cook-
Decatur-Dougherty-Early-Grady-Irwin-Lanier-Lee-Lowndes-
Miller-Mitchell-Quitman-Randolph-Seminole-Terrell-Thomas-
Tift-Turner-Worth.
AL...FREEZE WATCH from late tonight through Friday morning for
Coffee-Dale-Geneva-Henry-Houston.
GM...SMALL CRAFT ADVISORY until 1 PM EST this afternoon for
Apalachee Bay or Coastal Waters From Keaton Beach to
Ochlockonee River Fl out to 20 Nm-Coastal Waters From
Ochlockonee River to Apalachicola Fl out to 20 Nm-Coastal
waters from Suwannee River to Keaton Beach out 20 NM-
Coastal waters from Apalachicola to Destin FL out 20 NM-
Waters from Suwannee River to Apalachicola FL from 20 to
60 NM-Waters from Apalachicola to Destin FL from 20 to 60
NM.
&&
$$
NEAR TERM...Fournier
SHORT TERM...Gould
LONG TERM...Harrigan
AVIATION...Fournier
MARINE...Fournier/Gould
FIRE WEATHER...Fournier/Gould
HYDROLOGY...Gould
AREA FORECAST DISCUSSION
NWS MIAMI FL
136 AM EST THU JAN 31 2013
.AVIATION...
THE LATEST MODEL GUIDANCE SHOWS A NARROW LINE OF SHOWERS ALONG
THE FRONTAL BOUNDARY APPROACHING THROUGH THE FIRST FEW HOURS OF
THE TAF CYCLE...THROUGH APF BY/AROUND DAYBREAK...THEN THROUGH THE
EAST COAST TERMINALS THROUGH THE EARLY/MID MORNING HOURS. WINDS
WILL SHIFT FROM THE SOUTH TO NORTHWEST WITH THE FROPA. ALTHOUGH A
FEW PERIODS WITH MVFR CIGS CAN`T BE RULED OUT IN AND AROUND ANY
SHOWERS ALONG THE FRONT...MOSTLY VFR CONDITIONS ARE EXPECTED. IN
THE WAKE OF THE FRONTAL BOUNDARY...A STABLE LOW-LEVEL STATUS DECK
WILL LIKELY LINGER THROUGH A GOOD PORTION OF THE DAY BEFORE
GRADUALLY CLEARING.
&&
.PREV DISCUSSION... /ISSUED 855 PM EST WED JAN 30 2013/
UPDATE...
COLD FRONT MOVING THROUGH THE PANHANDLE THIS EVENING WILL APPROACH
SOUTH FLORIDA AFTER MIDNIGHT TONIGHT. LOCAL WRF AND HRRR SHOW A
THIN LINE OF SHOWERS APPROACHING THE NORTHWEST PORTIONS OF THE CWA
AROUND 09Z TONIGHT...AND THEN THE LINE SLOWLY MOVING THROUGH THE
REST OF THE REGION THROUGH THE MORNING HOURS. THE CURRENT POP
GRIDS HANDLE THIS WELL...SO NO UPDATES ARE NEEDED. TEMPERATURES
TONIGHT WILL BE WARM...WITH LOWS NEAR 60 TO THE LOWER 70S.
ALTHOUGH WINDS WILL LIKELY FALL BELOW SCA CRITERION OVER THE
LOCAL GULF WATERS THIS EVENING...KEPT THE SCA GOING AS WINDS WILL
INCREASE LATE TONIGHT BEHIND THE FRONT. FOR THE ATLANTIC
WATERS...WILL CANCEL THE SCA SINCE THE WINDS HAVE FALLEN TO AROUND
10-15 KNOTS AND WINDS ARE NOT EXPECTED TO INCREASE TO SCA
CONDITIONS AGAIN UNTIL AFTER 18Z ON THURSDAY.
PREV DISCUSSION... /ISSUED 628 PM EST WED JAN 30 2013/
AVIATION...VFR WILL PREVAIL, BUT A FEW SHOWERS/BRIEF MVFR WILL BE
POSSIBLE ALONG COLD FRONT EXPECTED TO MOVE ACROSS KAPF AT AROUND
SUNRISE, THEN THE EAST COAST TERMINALS BY MID MORNING THU. CURRENT
WIND OBS ARE SSE BUT ACARS DATA SHOWS SSW JUST ABOVE THE SFC.
VEERED WINDS THROUGH THE NIGHT TO SSW AS FRONT APPROACHES, THEN
TURNED WINDS NW BEHIND THE COLD FRONT THU. GUIDANCE SUGGEST
CLOUDS LIKELY WILL HANG TOUGH BEHIND THE FRONT FOR THE EAST COAST
TERMINALS THROUGHOUT THE DAY THU. BEST PROSPECTS FOR SHOWERS/BRIEF
MVFR CIGS LOOK TO BE 10-15Z THU, EXCEPT 06-12Z AT KAPF. THX CWSU
MIAMI FOR COORDINATION. /GREGORIA
PREV DISCUSSION... /ISSUED 237 PM EST WED JAN 30 2013/
SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH SOUTH FLORIDA THURSDAY
MORNING...ENDING THE ABOVE NORMAL TEMPERATURES AND BRINGING A
SLIGHT CHANCE OF SHOWERS AS IT PASSES. HIGH PRESSURE BUILDS IN
FRIDAY THROUGH THE WEEKEND...WITH SLIGHTLY BELOW NORMAL
TEMPERATURES RISING TO NEAR SEASONAL AVERAGES BY EARLY NEXT WEEK.
SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
BREEZY CONDITIONS IN PLACE THROUGH FLORIDA AS PRESSURE GRADIENT
BETWEEN THE SUBTROPICAL RIDGE OVER WESTERN ATLANTIC AND SURFACE
COLD FRONT MOVING EASTWARD THROUGH THE DEEP SOUTH INCREASES. SOUTH
WINDS HAVE GUSTED TO NEAR 30 KTS...JUST BELOW WIND ADVISORY
CRITERION. GUSTS MAY DIURNALLY DIMINISH SLIGHTLY...BUT REMAIN HIGH
ENOUGH TO PRECLUDE ANY FOG FORMATION TONIGHT. TEMPERATURES AHEAD
OF THE FRONT CONTINUE TO BE ABOVE NORMAL...WITH READINGS NEAR 80F
ACROSS MOST OF SOUTH FLORIDA.
MODELS HAVE TRENDED A BIT SLOWER FOR FROPA FOR SOUTH FLORIDA. THE
SFC FRONT LOCATED NEAR KPNS NOW WILL TREK ACROSS THE PANHANDLE
THIS EVENING...THEN APPROACH I-4 CORRIDOR OVERNIGHT. IT IS NOT
EXPECTED TO INTRUDE ON NORTHWEST SECTIONS OF OUR CWA UNTIL AROUND
SUNRISE. THUS...WARM AND FAIRLY BREEZY NIGHT IS IN STORE. MINIMA
WILL RANGE FROM AROUND 60F NORTHWEST INTERIOR TO AROUND 70F
ATLANTIC METROS. THE COLD FRONT WILL MOVE ACROSS SOUTH FLORIDA
DURING THE MORNING...ACCOMPANIED BY A FEW SHOWERS. DYNAMICAL
FORCING WILL BE NEGLIGIBLE AND ATMOSPHERE WILL REMAIN FAIRLY
STABLE...BUT LOW-LEVEL CONVERGENCE AND DECENT MOISTURE CONTENT
SHOULD BE SUFFICIENT FOR SCATTERED ACTIVITY ALONG AND IN VICINITY
OF SURFACE BOUNDARY. CAA WILL LAG SEVERAL HOURS BEHIND THE
FRONT...SO HIGH TEMPERATURES WILL STILL REACH M/U70S MOST
LOCATIONS.
SKIES CLEAR AND TEMPERATURES PLUMMET THURSDAY NIGHT...AND DESPITE
LACK OF IDEAL RADIATIONAL COOLING CONDITIONS...ADVECTION SHOULD
SUPPORT MINIMA REACHING BELOW 50F FOR MUCH OF THE INTERIOR...AND
SOME 30S ARE POSSIBLE ACROSS COLLIER...GLADES...AND HENDRY COUNTY.
IT APPEARS DRY LOW LEVELS AND NON-ZERO WIND SPEEDS WILL PREVENT
ANY FROST...BUT THIS WILL BE MONITORED. AFOREMENTIONED WINDS
HOWEVER WILL CREATE WIND CHILL VALUES SOME 5-10 DEGREES LOWER THAN
AMBIENT READINGS...LOW ENOUGH TO POSSIBLY REACH ADVISORY
THRESHOLDS ACROSS MAINLY GLADES AND HENDRY COUNTIES.
TEMPERATURES FRIDAY AND FRIDAY NIGHT WILL BE SLIGHTLY BELOW
NORMAL...WITH L70S FOR MAXIMA AND 40S INLAND/50S COASTAL FOR
MINIMA. HIGH PRESSURE BUILDING SOUTH WILL KEEP SKIES CLEAR...AND
NORTH WINDS WILL GRADUALLY BECOME NORTHEAST AND BECOME QUITE LIGHT
OVERNIGHT FRIDAY. TEMPERATURES ATTM APPEAR JUST ABOVE VALUES THAT
WOULD CAUSE FROST CONCERN AND LACK OF WIND SHOULD PRECLUDE ANY
WIND CHILL CONCERNS.
LONG TERM /SATURDAY THROUGH WEDNESDAY/...
THE EXTENDED PERIOD FROM THIS WEEKEND INTO THE MIDDLE OF NEXT WEEK
LOOKS UNEVENTFUL AND DRY AS SEVERAL MID LEVEL TROUGHS MOVE ACROSS
THE NORTHERN STATES MAINTAINING A WEST TO NORTHWEST FLOW OF DRY
AIR OVER THE FLORIDA PENINSULA AND KEEPING THE MID LEVEL RIDGE
SUPPRESSED TO OUR SOUTHEAST. AS THE TROUGHS MOVE TO OUR NORTH,
THIS WILL ALSO REINFORCE THE SURFACE RIDGING ACROSS THE SOUTHEAST
STATES WHICH IN TURN WILL KEEP THE TEMPERATURES CLOSE TO OR
SLIGHTLY BELOW CLIMATOLOGICAL AVERAGES FOR THE BEGINNING OF FEBRUARY.
AVIATION...
GUSTY SOUTHEASTERLY WINDS WILL CONTINUE THROUGH THE TAF PERIOD AT
ALL SITES. FROPA IS STILL EXPECTED ACROSS THE EAST COAST TERMINALS
BETWEEN 10Z-13Z ACCOMPANIED BY SCATTERED SHOWERS. BRIEF PERIODS OF
MVFR CIGS WILL LIKELY ACCOMPANY ANY SHOWER ACTIVITY BUT SHOULD NOT
BE LONG ENOUGH TO PREVAIL IN THE TAF. WINDS WILL TURN AROUND TO
THE NORTHWEST BEHIND THE FRONT AND REMAIN AT AROUND 10 KNOTS.
MARINE...
WINDS NEAR 20 KTS WITH SOUTHERLY GUSTS TO NEAR 30 KTS WARRANTED
ISSUANCE OF SMALL CRAFT ADVISORY EARLY TODAY...AND THIS WILL
REMAIN IN EFFECT FOR ALL MARINE ZONES OVERNIGHT. STRONG WINDS
BEING INDUCED BY TIGHT PRESSURE GRADIENT IN ADVANCE OF QUICK-
MOVING COLD FRONT. THIS FRONT WILL PASS THROUGH EARLY
FRIDAY...WITH NORTH WINDS LIKELY EXCEEDING ADVISORY THRESHOLD
BEHIND IT. STRONG WINDS AND BUILDING SEAS WILL IMPACT THE WATERS
THURSDAY NIGHT THROUGH AT LEAST FRIDAY...BEFORE SUBSIDING AS HIGH
PRESSURE BUILDS OVERHEAD.
FIRE WEATHER...
NO FIRE WEATHER CONCERNS TODAY. A COLD FRONT WILL RACE THROUGH
SOUTH FLORIDA THURSDAY MORNING...WITH MUCH DRIER AIR MOVING IN IN
ITS WAKE. RELATIVE HUMIDITY VALUES MAY DROP TO NEAR 35 PERCENT
THURSDAY AFTERNOON ACROSS GLADES AND HENDRY COUNTIES AND NORTH
WINDS WILL BE 10 TO 15 MPH OR HIGHER. FORECAST CONDITIONS DONT
SUPPORT ISSUANCE OF FIRE WEATHER WATCH...BUT A FIRE DANGER
STATEMENT HAS BEEN ISSUED THURSDAY. RELATIVE HUMIDITY WILL BE
VERY LOW FRIDAY...BUT WINDS WILL SUBSIDE A BIT. STILL...FIRE
WEATHER HEADLINES ARE LIKELY ON FRIDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 75 52 71 54 / 30 - 0 0
FORT LAUDERDALE 79 56 72 60 / 30 - 0 0
MIAMI 80 57 72 59 / 20 - 0 0
NAPLES 71 46 71 49 / 20 - 0 0
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR COASTAL
WATERS FROM CHOKOLOSKEE TO BONITA BEACH, FL OUT 20 NM-
COASTAL WATERS FROM EAST CAPE SABLE TO CHOKOLOSKEE, FL OUT
20 NM-GULF WATERS FROM CHOKOLOSKEE TO BONITA BEACH, FL
EXTENDING FROM 20 TO 60 NM.
&&
$$
DISCUSSION/MARINE/FIRE...30/KOB
AVIATION/RADAR...85/AG
AREA FORECAST DISCUSSION
NWS LINCOLN IL
848 PM CST FRI FEB 1 2013
.DISCUSSION...
ISSUED 845 PM CST FRI FEB 1 2013
HAVE SENT SOME ZONE/GRID UPDATES MAINLY TO REFLECT THE LATEST SNOW
TRENDS. SO FAR...THE MAIN AXIS OF THE SNOW HAS BEEN EXTENDING INTO
NORTHWEST ILLINOIS...WHERE THE LIFT HAS BEEN HIGHEST. HAVE SEEN A
FEW FLURRIES AS FAR SOUTH AS QUINCY...BUT MOST OBSERVATIONS
UPSTREAM OF CENTRAL ILLINOIS HAVE SHOWN ALTOCUMULUS PREVAILING.
WILL START SEEING SOME INCREASING ISENTROPIC LIFT OVER CENTRAL
ILLINOIS TOWARD LATE EVENING...AND LATEST RAP/NAM MODELS HAVE BEEN
DEVELOPING AN AREA OF LIGHT SNOW NEAR THE MIDDLE OF THE CWA AND
SHIFTING IT SOUTHEAST. MOST AREAS NOW EXPECTED TO RECEIVE LESS
THAN AN INCH OF SNOW...BUT SOME 1 INCH OR HIGHER TOTALS ARE
POSSIBLE ACROSS THE NORTHEAST AND EASTERN CWA.
GEELHART
&&
.AVIATION...
ISSUED 535 PM CST FRI FEB 1 2013
MAIN CONCERN WITH THIS TAF SET WILL BE WITH DEVELOPMENT OF MVFR
CONDITIONS AS AN ALBERTA CLIPPER RACES TOWARD THE AREA. MAIN
SYSTEM CURRENTLY BACK IN SOUTH DAKOTA AND SHOULD TRACK INTO
NORTHERN ILLINOIS OVERNIGHT. LATEST HIGH-RESOLUTION MODELS SUGGEST
THE HEAVIEST SNOW AXIS MAY TRACK MORE IN NORTHERN ILLINOIS...
ALTHOUGH THE RAP AND HRRR MODELS SHOW A SEPARATE AREA OF SNOW
DEVELOPING TOWARD 06Z IN CENTRAL ILLINOIS. HAVE DELAYED THE
STARTING TIME OF THE SNOW A BIT AS UPSTREAM OBS HAVE MOST OF THE
SNOW BACK IN SOUTHERN MINNESOTA AT 23Z. MOST OF THE SNOW SHOULD BE
EXITING THE AREA BY 12Z...BUT MAY SEE SOME LINGERING IN EASTERN
ILLINOIS INTO MID MORNING AS THE ACTUAL COLD FRONT PASSES.
CEILINGS SHOULD BE AROUND 6000 FEET MOST OF THE EVENING...THEN
START TO WORK THEIR WAY DOWN. HAVE KEPT MVFR CEILINGS PREVAILING
BY AROUND 06Z. MAY SEE CEILINGS BACK UP INTO VFR RANGE BY EARLY TO
MID AFTERNOON...BEFORE HEADING BACK DOWN AGAIN AHEAD OF THE NEXT
CLIPPER.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 300 PM CST FRI FEB 1 2013
THE ARCTIC OUTBREAK WILL LOSE SOME OF ITS BITE OVER THE NEXT
COUPLE OF DAYS...BUT REPEATED BRUSHES WITH CLIPPER SYSTEMS JUST TO
OUR NORTH-NORTHEAST WILL KEEP CHILLY AIR IN PLACE INTO NEXT WEEK.
THE MAIN SNOWFALL PERIOD WILL COME TONIGHT THROUGH SATURDAY
NIGHT...AS THE MORE SOUTHERLY TRACKS OF THE FIRST TWO CLIPPERS
WILL ALLOW THEM TO AFFECT MORE OF CENTRAL IL. THE NEXT SET OF
CLIPPERS FOR MONDAY AND TUESDAY WILL BE FARTHER NORTH ACROSS
NORTHERN ILLINOIS...WITH ONLY LIMITED INFLUENCE ON OUR
COUNTIES...AND MAINLY JUST THE E AND NE COUNTIES. THE EXPECTED
WARM UP WILL BE A BIT TEMPERED FROM PREVIOUS INDICATIONS...WITH
HIGHS REACHING THE UPPER 30S TO AROUND 40 THUR AND FRIDAY.
SHORT TERM...TONIGHT THROUGH SUNDAY.
CLOUDS ARE STREAMING AHEAD OF OUR INITIAL WEATHER SYSTEM FOR
TONIGHT INTO SATURDAY. THE PARENT LOW IS STILL BACK OVER SOUTH
DAKOTA AND NEBRASKA BUT IS MAKING STEADY PROGRESS TO THE ESE.
ISENTROPIC LIFT AND LOW CONDENSATION PRESSURE DEFICITS WILL PEAK
AROUND MIDNIGHT TONIGHT...AS SNOWFALL BEGINS ACROSS OUR WESTERN
COUNTIES BY 9 PM OR SO. SNOWFALL WILL CONTINUE TO EXPAND EASTWARD
OVER NIGHT...PRODUCING THE HEAVIER SNOWFALL AMOUNTS NORTHEAST OF A
LINE FROM CANTON TO PARIS...WHERE 1 TO 2 INCHES ARE POSSIBLE BY
SATURDAY MORNING. SOUTHWEST OF THERE...SNOW TOTALS WILL DROP OFF TO
TRACE TO HALF INCH AMOUNTS TOWARD JACKSONVILLE.
THE NEXT WAVE OF MEASURABLE SNOW IS EXPECTED SATURDAY
NIGHT...ALTHOUGH LIMITED MOISTURE AND SHORTER DURATION OF SNOW
WILL LIMIT THE ADDITIONAL ACCUMULATION TO LESS THAN AN INCH ACROSS
CENTRAL IL. THAT SYSTEM WILL BE MORE DISJOINTED AS THE LOWER COND
PRES DEF WILL PRECEDE THE BETTER ISENTROPIC LIFT...WHICH WILL
ARRIVE SAT EVENING. SO A BROAD DUSTING TO A HALF INCH OF SNOW
SEEMS TO BE A REASONABLE EXPECTATION FOR THAT SAT AFTERNOON/SAT
NIGHT SYSTEM.
LONG TERM...SUNDAY NIGHT THROUGH FRIDAY.
THE LATE WEEKEND CLIPPER ON SUNDAY NIGHT AND MONDAY WILL SEE THE
BEST FORCING FOR PRECIP REMAIN NORTH OF OUR COUNTIES SUNDAY
NIGHT...WITH SOME LIGHT RAIN OR SNOW POSSIBLE IN OUR EASTERN AREAS
ON MONDAY. LITTLE TO NO RAIN OR SNOW ACCUMS ARE EXPECTED...SO WE
KEPT ONLY SLIGHT CHANCE POPS IN THE GRIDS.
THE SYSTEM FOR TUESDAY WILL HAVE A BETTER ORGANIZED COUPLING OF
MOISTURE AND FORCING ACROSS NORTHERN ILLINOIS...WHICH MAY PRODUCE
SOME LIGHT SNOW ACROSS THE NORTHEASTERN THIRD OF OUR COUNTIES. WE
MAINLY KEPT POPS DOWN IN THE SLIGHT CHANCE CATEGORY...EXCEPT FOR A
SLIVER OF CHANCE POPS FROM HENRY TO EL PASO. THAT SYSTEM LOOKS
LIKE IT MAY EVOLVE INTO A MORE PROMINENT SYSTEM AS THE MODELS GET
CLOSER TO THE EVENT.
BEYOND THAT...A COLD FRONT PROJECTED FOR THURSDAY AND THURSDAY
NIGHT IS TRENDING DRIER IN THE GFS AND EVEN THE ECMWF A LITTLE.
WE KEPT POPS IN THE CHANCE CATEGORY FOR RAIN OR SNOW...BUT TRENDED
LOWER DUE TO THE SHIFTING TRACK OF THE PARENT SURFACE LOW FARTHER
FROM IL...AND A WEAKER FRONTAL SYSTEM PASSING OVER IL.
SHIMON
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
537 PM CST FRI FEB 1 2013
.DISCUSSION...
ISSUED 300 PM CST FRI FEB 1 2013
THE ARCTIC OUTBREAK WILL LOSE SOME OF ITS BITE OVER THE NEXT
COUPLE OF DAYS...BUT REPEATED BRUSHES WITH CLIPPER SYSTEMS JUST TO
OUR NORTH-NORTHEAST WILL KEEP CHILLY AIR IN PLACE INTO NEXT WEEK.
THE MAIN SNOWFALL PERIOD WILL COME TONIGHT THROUGH SATURDAY
NIGHT...AS THE MORE SOUTHERLY TRACKS OF THE FIRST TWO CLIPPERS
WILL ALLOW THEM TO AFFECT MORE OF CENTRAL IL. THE NEXT SET OF
CLIPPERS FOR MONDAY AND TUESDAY WILL BE FARTHER NORTH ACROSS
NORTHERN ILLINOIS...WITH ONLY LIMITED INFLUENCE ON OUR
COUNTIES...AND MAINLY JUST THE E AND NE COUNTIES. THE EXPECTED
WARM UP WILL BE A BIT TEMPERED FROM PREVIOUS INDICATIONS...WITH
HIGHS REACHING THE UPPER 30S TO AROUND 40 THUR AND FRIDAY.
SHORT TERM...TONIGHT THROUGH SUNDAY.
CLOUDS ARE STREAMING AHEAD OF OUR INITIAL WEATHER SYSTEM FOR
TONIGHT INTO SATURDAY. THE PARENT LOW IS STILL BACK OVER SOUTH
DAKOTA AND NEBRASKA BUT IS MAKING STEADY PROGRESS TO THE ESE.
ISENTROPIC LIFT AND LOW CONDENSATION PRESSURE DEFICITS WILL PEAK
AROUND MIDNIGHT TONIGHT...AS SNOWFALL BEGINS ACROSS OUR WESTERN
COUNTIES BY 9 PM OR SO. SNOWFALL WILL CONTINUE TO EXPAND EASTWARD
OVER NIGHT...PRODUCING THE HEAVIER SNOWFALL AMOUNTS NORTHEAST OF A
LINE FROM CANTON TO PARIS...WHERE 1 TO 2 INCHES ARE POSSIBLE BY
SATURDAY MORNING. SOUTHWEST OF THERE...SNOW TOTALS WILL DROP OFF TO
TRACE TO HALF INCH AMOUNTS TOWARD JACKSONVILLE.
THE NEXT WAVE OF MEASURABLE SNOW IS EXPECTED SATURDAY
NIGHT...ALTHOUGH LIMITED MOISTURE AND SHORTER DURATION OF SNOW
WILL LIMIT THE ADDITIONAL ACCUMULATION TO LESS THAN AN INCH ACROSS
CENTRAL IL. THAT SYSTEM WILL BE MORE DISJOINTED AS THE LOWER COND
PRES DEF WILL PRECEDE THE BETTER ISENTROPIC LIFT...WHICH WILL
ARRIVE SAT EVENING. SO A BROAD DUSTING TO A HALF INCH OF SNOW
SEEMS TO BE A REASONABLE EXPECTATION FOR THAT SAT AFTERNOON/SAT
NIGHT SYSTEM.
LONG TERM...SUNDAY NIGHT THROUGH FRIDAY.
THE LATE WEEKEND CLIPPER ON SUNDAY NIGHT AND MONDAY WILL SEE THE
BEST FORCING FOR PRECIP REMAIN NORTH OF OUR COUNTIES SUNDAY
NIGHT...WITH SOME LIGHT RAIN OR SNOW POSSIBLE IN OUR EASTERN AREAS
ON MONDAY. LITTLE TO NO RAIN OR SNOW ACCUMS ARE EXPECTED...SO WE
KEPT ONLY SLIGHT CHANCE POPS IN THE GRIDS.
THE SYSTEM FOR TUESDAY WILL HAVE A BETTER ORGANIZED COUPLING OF
MOISTURE AND FORCING ACROSS NORTHERN ILLINOIS...WHICH MAY PRODUCE
SOME LIGHT SNOW ACROSS THE NORTHEASTERN THIRD OF OUR COUNTIES. WE
MAINLY KEPT POPS DOWN IN THE SLIGHT CHANCE CATEGORY...EXCEPT FOR A
SLIVER OF CHANCE POPS FROM HENRY TO EL PASO. THAT SYSTEM LOOKS
LIKE IT MAY EVOLVE INTO A MORE PROMINENT SYSTEM AS THE MODELS GET
CLOSER TO THE EVENT.
BEYOND THAT...A COLD FRONT PROJECTED FOR THURSDAY AND THURSDAY
NIGHT IS TRENDING DRIER IN THE GFS AND EVEN THE ECMWF A LITTLE.
WE KEPT POPS IN THE CHANCE CATEGORY FOR RAIN OR SNOW...BUT TRENDED
LOWER DUE TO THE SHIFTING TRACK OF THE PARENT SURFACE LOW FARTHER
FROM IL...AND A WEAKER FRONTAL SYSTEM PASSING OVER IL.
SHIMON
&&
.AVIATION...
ISSUED 535 PM CST FRI FEB 1 2013
MAIN CONCERN WITH THIS TAF SET WILL BE WITH DEVELOPMENT OF MVFR
CONDITIONS AS AN ALBERTA CLIPPER RACES TOWARD THE AREA. MAIN
SYSTEM CURRENTLY BACK IN SOUTH DAKOTA AND SHOULD TRACK INTO
NORTHERN ILLINOIS OVERNIGHT. LATEST HIGH-RESOLUTION MODELS SUGGEST
THE HEAVIEST SNOW AXIS MAY TRACK MORE IN NORTHERN ILLINOIS...
ALTHOUGH THE RAP AND HRRR MODELS SHOW A SEPARATE AREA OF SNOW
DEVELOPING TOWARD 06Z IN CENTRAL ILLINOIS. HAVE DELAYED THE
STARTING TIME OF THE SNOW A BIT AS UPSTREAM OBS HAVE MOST OF THE
SNOW BACK IN SOUTHERN MINNESOTA AT 23Z. MOST OF THE SNOW SHOULD BE
EXITING THE AREA BY 12Z...BUT MAY SEE SOME LINGERING IN EASTERN
ILLINOIS INTO MID MORNING AS THE ACTUAL COLD FRONT PASSES.
CEILINGS SHOULD BE AROUND 6000 FEET MOST OF THE EVENING...THEN
START TO WORK THEIR WAY DOWN. HAVE KEPT MVFR CEILINGS PREVAILING
BY AROUND 06Z. MAY SEE CEILINGS BACK UP INTO VFR RANGE BY EARLY TO
MID AFTERNOON...BEFORE HEADING BACK DOWN AGAIN AHEAD OF THE NEXT
CLIPPER.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
256 PM CST THU JAN 31 2013
.DISCUSSION...
1016 AM CST
FOR MORNING UPDATE...
HAVE MADE A FEW ADJUSTMENTS TO NEAR TERM FORECAST THIS MORNING... TO
BUMP POPS A BIT FOR OCCASIONAL SNOW SHOWERS. HAVE SEEN SOME ISOLATED
VISIBILITY REDUCTIONS LESS THAN A MILE AT TIMES THIS MORNING WITH A
FEW PLACES PICKING UP A DUSTING TO A TENTH OF AN INCH OR SO. HAVE
ALSO TOUCHED UP SKY COVER GRIDS...ACCOUNT SIGNIFICANT OPEN PATCHES
THIS MORNING ACROSS WEST/SOUTH PARTS OF CWA AND CONVECTIVE NATURE OF
EXPECTED CLOUD COVER THROUGH THE DAY.
MORNING ANALYSIS INDICATES DEEPENING SURFACE LOW CONTINUES TO TRACK
AWAY WELL TO OUR NORTHEAST ACROSS SOUTHERN QUEBEC...WITH COLD FRONT
TRAILING THROUGH NORTHERN INDIANA/CENTRAL ILLINOIS. COLD ARCTIC AIR
CONTINUES TO SPREAD SOUTHEAST ACROSS THE UPPER MIDWEST BEHIND THIS
FRONT...WITH SINGLE DIGIT AND SUB-ZERO TEMPS WIDESPREAD TO OUR
WEST/NORTHWEST. LOOKING ALOFT...RATHER STRONG MID-LEVEL SHORT WAVE
WAS NOTED OVER THE EASTERN DAKOTAS/MINNESOTA...AND THIS WAVE IS
PROGGED TO CONTINUE TO MOVE SOUTHEAST ACROSS OUR AREA THROUGH THIS
EVENING.
SCATTERED SNOW SHOWERS...SOME FAIRLY INTENSE WITH VISIBILITY
REDUCTIONS AND BRIEF MINOR ACCUMULATIONS...HAVE BEEN PREVALENT
ACROSS NORTHEAST IL THIS MORNING. THESE APPEAR TO BE HIGHLY DRIVEN
BY STEEP LOW LEVEL LAPSE RATES AS EVIDENCED BY 12Z ILX RAOB AND
RECENT AIRCRAFT AMDAR SOUNDINGS FROM ORD...WHICH DEPICT ADIABATIC
LOW LEVEL PROFILES FROM THE SURFACE UP TO ABOUT 850-800 MB. THIS
ALSO COINCIDES NICELY WITH THE -12 TO -18C FAVORED TEMPERATURE LAYER
FOR GOOD DENDRITIC GROWTH OF ICE CRYSTALS...OF WHICH HAVE BEEN
OBSERVED AT TIMES THIS MORNING. FORECAST SOUNDINGS FROM MORNING RUNS
OF THE WRF-NAM AND RAP MAINTAIN THESE STEEP LOW LEVEL LAPSE RATES
THROUGH THE DAY...COINCIDENT WITH BETTER MID/UPPER LEVEL FORCING
ASSOCIATED WITH THE APPROACH AND PASSAGE OF AFOREMENTIONED UPPER
MIDWEST SHORT WAVE. DEPSITE DRY ADVECTION OF ARCTIC AIR AND EVEN
THOUGH VIS SATELLITE IMAGERY IS NOT TOO IMPRESSIVE WITH CLOUD
COVER...SUSPECT THAT THIN STRATOCU WILL CONTINUE TO DEVELOP AND
PERHAPS INCREASE IN COVERAGE IN UNSTABLE LOW LEVEL THERMODYNAMIC
ENVIRONMENT...AND SHOULD BE ABLE TO SUSTAIN SNOW SHOWERS AND
FLURRIES WITH SUFFICIENT INTENSITY AT TIMES TO PRODUCE SOME MINOR
ACCUMS IN LOCALIZED AREAS. THEREFORE HAVE BUMPED POPS TO HIGHER
CHANCE CATEGORY...AND WORDED OCCASIONAL SNOW SHOWERS/FLURRIES WITH A
FEW TENTHS OF AN INCH POSSIBLE FOR MUCH OF NORTHERN 2/3 OR SO OF THE
CWA THROUGH THE DAY...AND THIS EVENING. MID-LEVEL TROUGH AXIS MOVES
ACROSS THE REGION LATE EVENING/MIDNIGHT TIME FRAME...AFTER WHICH
FORECAST SOUNDINGS DEPICT STRENGTHENING/LOWERING SUBSIDENCE
INVERSION WHICH SHOULD LIMIT FURTHER MEASURABLE PRECIP THREAT.
OTHERWISE...GOING FORECAST LOOKS GOOD THROUGH THIS AFTERNOON WITH
TEMPS NOT GOING ANYWHERE...AND COLD...BLUSTERY CONDITIONS.
RATZER
//PREV DISCUSSION...
340 AM CST
PRIMARY FORECAST CHALLENGE THIS MORNING IS CLOUD COVER AND ITS
IMPACT ON TEMPS THE NEXT SEVERAL DAYS AS WELL AS FLURRY/LIGHT SNOW
CHANCES.
PHASE ONE OF ARCTIC AIR HAS MOVED INTO THE AREA WITH PHASE 2 STILL
UPSTREAM AND POISED TO ARRIVE THIS AFTERNOON INTO TONIGHT. AS
ALLUDED TO LAST NIGHT GUIDANCE HAS BEEN FAR TOO COLD WITH TEMPS
OVERNIGHT INTO THE EARLY MORNING HOURS THIS MORNING...RUNNING IN
SOME CASES MORE THAN 5F TOO COLD AT 9Z THANKS TO THE CLOUD COVER AND
WIND. NO APPRECIABLE CLEARING IS ANTICIPATED PRIOR TO SUNRISE SO A
VERY SLOW (1-2F EVERY HOUR OR TWO) FALL SHOULD CONTINUE THROUGH
SUNRISE. WITH THE RE-ENFORCING SHOT OF COLD AIR ARRIVING THIS
AFTERNOON AND A GOOD DEAL OF CLOUD COVER/GUSTY NORTHWEST WINDS DONT
ANTICIPATE TEMPS TO REBOUND MUCH FROM EARLY MORNING READINGS WITH
TEMPS FAIRLY STEADY MOST OF THE DAY.
ALONG WITH THE ARRIVAL OF THE COLD AIR...WATER VAPOR IMAGERY SHOWS A
COUPLE OF VORTS UPSTREAM OVER THE NORTHERN PLAINS THAT WILL PIVOT
SOUTHEAST INTO THE AREA THIS AFTERNOON/EVENING. ICE CRYSTALS ARE
LIKELY ALREADY PRESENT IN THE STRATUS DECK GIVEN THE ARCTIC TEMPS SO
IT WILL REMAIN REMARKABLY EASY FOR LIGHT SNOW OR FLURRIES TO FALL
OUT OF THIS STRATUS DECK TODAY INTO TONIGHT...THOUGH ACCUMULATIONS
SHOULD BE MINIMAL FLAKES WILL LIKELY BE FLYING AT TIMES TODAY INTO
THIS EVENING.
CERTAINLY THE AIR MASS ADVECTING INTO THE AREA WILL BE VERY COLD
WITH EVENING SOUNDINGS UPSTREAM SAMPLING 850MB TEMPS NEAR
-20C...HOWEVER ITS NOT CLEAR HOW MUCH IF ANY CLEARING WILL TAKE
PLACE TONIGHT. IN THE ABSENCE OF CLEARING...THE WINDS AND CLOUDS
WOULD LIKELY KEEP TEMPS SEVERAL DEGREES WARMER THAN MOS LOWS AND
SUSPECT THAT CLOUDS WILL LINGER THROUGH THE NIGHT OVER EASTERN CWA
WITH SOME CLEAR LATE WEST. HAVE GENERALLY ADJUSTED LOW TEMPS UPWARD
SOME FROM PREVIOUS FORECAST AND GONE A BIT ABOVE THE WARMER MOS
GUIDANCE NUMBERS AS MODELS SUGGEST THAT LOW LEVEL CYCLONIC FLOW WILL
PERSIST MOST OF THE NIGHT RAISING SERIOUS DOUBTS ABOUT HOW MUCH
CLEARING WILL TAKE PLACE. IN ADDITION...THE AIR MASS THIS GO AROUND
WILL BE A COUPLE/FEW DEGREES MILDER AT 850MB THAN THE PREVIOUS ONE
AND WITH LITTLE/NO SNOW COVER MOST AREAS WOULD EXPECT LOWS TO BOTTOM
OUT NO COLDER THAN LAST GO AROUND AND IN ALL LIKELIHOOD A COUPLE
DEGREES WARMER (WELL LESS COLD). BASED ON THE FORECAST LOWS AND
EXPECTED WINDS LOOKS LIKE NC IL STANDS A REASONABLY GOOD CHANCE OF
REACHING THE -20F WIND CHILL ADVISORY CRITERIA AND SO HAVE GONE
AHEAD AND ISSUED THAT ALREADY THERE. FOR CHICAGO AREA AND POINTS
SOUTH AND EAST IT WILL UNDOUBTEDLY BE VERY COLD TONIGHT BUT APPEARS
UNLIKELY THAT THE -20F CRITERIA WILL BE MET FOR ANY LENGTH OF TIME
SO KEPT ADVISORY NORTH/WEST OF THESE AREAS.
COULD SEE SOME SUNSHINE THE FIRST HALF OF THE DAY ON FRIDAY BUT WILL
REMAIN QUITE COLD WITH CLOUDS ROLLING BACK IN IN THE AFTERNOON AS
FAST MOVING CLIPPER DIVES SE TOWARD THE AREA. VERY LITTLE CHANGE IN
MODEL GUIDANCE IN HANDLING THIS WAVE WITH SWATH OF ACCUMULATING VERY
FLUFFIFIED/HIGH RATION SNOW LIKELY ACROSS NORTHERN/CENTRAL ILLINOIS
FRIDAY NIGHT INTO SATURDAY MORNING. DESPITE LIMITED MOISTURE...HIGH
SNOW:LIQUID RATIOS COULD SUPPORT SOLID 2-3 INCH BAND OF SNOW...WITH
BEST PROJECTIONS AT THIS POINT PLACING THE HEAVIEST SNOW ALONG OR
SOUTH OF I-80. GIVEN HOW LOW AMPLITUDE THIS WAVE IS WOULD NOT BE A
STRETCH TO ENVISION LATER RUNS REFINING THE TRACK A BIT...BUT EVEN
WITH THAT IN MIND FELT FAIRLY COMFORTABLE CONTINUING THE TREND OF
BUMPING POPS UP A BIT HIGHER AGAIN THIS MORNING.
SEEMINGLY NEVER ENDING PARADE OF CLIPPERS ARE PROGGED TO CONTINUE TO
PIVOT AROUND THE BASE OF THE TROUGH HEADING INTO NEXT WEEK. THE 00Z
ECMWF HAS COME IN A BIT DEEPER AND FARTHER WEST WITH THE POLAR
VORTEX OVER THE REGION WHICH WOULD PLACE OUR CWA CLOSER TO THE COLD
SIDE OF THE PATH OF THESE CLIPPERS AND ALSO CLOSER TO POTENTIAL
LIGHT ACCUMULATING SNOWS. THE GEM...GFS...AND PREVIOUS ECMWF WERE
QUICKER TO WEAKEN THE POLAR VORTEX ALLOWING THE CLIPPERS TO PASS TO
OUR NORTH KEEPING US DRY WITH ALTERNATING BOUTS OF ABOVE AVERAGE
TEMPS AND SLIGHT COOL DOWNS WITH A TREND TOWARD SLIGHTLY WEAKER COOL
DOWNS WITH EACH WAVE. CONFIDENCE IS NOT TERRIBLY HIGH IN ANY ONE
SOLUTION AT THIS POINT BUT A TOWARD MODERATING TEMPS DEFINITELY
LOOKS REASONABLE HEADING INTO NEXT WEEK WITH LESS CERTAINTY
REGARDING PRECIP CHANCES.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* W WIND GUSTING 25-30 KT THROUGH THIS EVENING THEN GUSTS 15-20 KT
OVERNIGHT.
* PERIODS OF -SHSN THROUGH THE EARLY EVENING...HEAVIER BANDS COULD
DROP VSBY DOWN TO LESS THAN A MILE.
* HIGH END MVFR TO LOW END VFR CIGS EXPECTED THROUGH TONIGHT.
JEE
//DISCUSSION...UPDATED 18Z...
AN UPPER LEVEL SHORT WAVE TROUGH MOVED THROUGH THE DAKOTAS AND
PROVIDED FORCING FOR THE BANDS OF SNOW THE AREA SAW EARLIER THIS
MORNING. THE SHORTWAVE IS MOVING INTO IA WITH SHSN FORMING OVER
SOUTHERN WI. AS SUCH KEPT OCNL FLURRIES IN FOR THE TERMINALS
THROUGH 20Z AND EXPECTING MORE SUBSTANTIAL -SHSN AFTER 20Z. THEY
COULD DEVELOP A LITTLE LATER THAN INDICATED...WITH ARND A HALF
INCH OF SNOW PSBL. THE HEAVIER BANDS IN WI ARE ASSOCIATED WITH VSBY
OF LESS THAN 1 MILE...BUT WILL ADDRESS THOSE HEAVIER BANDS AS THEY
SET UP. OVERALL THINKING VSBYS WILL BE 4SM OR BETTER. EXPECTING
CIGS TO DROP A LITTLE WITH THE SNOW AS WELL TO ARND 020. A FEW
UPSTREAM OBS INDICATE 015 CIGS ARE PSBL SO WILL KEEP AN EYE ON HOW
THE LOWER CIGS PROGRESS.
WINDS WILL REMAIN W GUSTING TO 25 KT THROUGH THE MID AFTN WITH
GUSTS INCREASING TO 25-30KT THROUGH THE EVENING. WEST WINDS
GUSTING 15-20 KT ARE THEN EXPECTED OVERNIGHT UNDER THE TIGHTENED
PRESSURE GRADIENT. HIGH PRESSURE SINKS SOUTH TO THE EAST OF THE
TERMINALS ALLOWING SKIES TO SCATTER OUT TOMORROW.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN PRECIP FCST...MEDIUM CONFIDENCE IN TIMING AND
VSBY ASSOCIATED WITH -SN/-SHSN.
* HIGH CONFIDENCE IN ALL OTHER FCST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
12Z...
FRIDAY NIGHT...ACCUMULATING SNOW BECOMING LIKELY. MVFR BECOMING
IFR.
SATURDAY...MVFR WITH A CHANCE OF IFR SNOW SHOWERS...MAINLY IN THE
MORNING.
SUNDAY...MVFR.
MONDAY...VFR.
TUESDAY...VFR.
WEDNESDAY...VFR.
TRS
&&
.MARINE...
255 PM CST
GUSTY WEST-NORTHWEST WINDS...ARCTIC AIR AND FREEZING SPRAY ARE THE
MAIN CONCERNS IN THE NEAR TERM...WITH MARGINAL GALE FORCE WINDS
EXPECTED ON THE SOUTH END OF THE LAKE OVERNIGHT. WINDS WILL
GRADUALLY DIMINISH FRIDAY...THOUGH AIR TEMPS IN THE SINGLE DIGITS TO
LOW TEENS WILL LIKELY CONTINUE TO RESULT IN FREEZING SPRAY EARLY IN
THE DAY. HAVE EXTENDED INDIANA NEARSHORE SMALL CRAFT ADVISORY
THROUGH EARLY SATURDAY MORNING...WHERE WAVES WILL BE A LITTLE
SLOWER TO SUBSIDE IN PERSISTENT WEST-NORTHWEST FLOW.
COLD CANADIAN HIGH PRESSURE WILL CONTINUE TO PUSH SOUTHEAST FROM THE
LOWER MISSOURI VALLEY INTO THE SOUTHEASTERN U.S. FRIDAY EVENING...
WITH WEAKER HIGH PRESSURE RIDGING MOVING ACROSS THE WESTERN LAKES
AND ALLOWING THE GRADIENT TO RELAX AND WIND SPEEDS TO DIMINISH MORE
SIGNIFICANTLY. A WEAK LOW WILL MOVE THROUGH THE MIDWEST SATURDAY...
JUST SOUTH OF THE LAKES...WHICH MAKES FOR A LITTLE LOWER CONFIDENCE
IN WIND DIRECTION AS THE GRADIENT REMAINS WEAK/BAGGY NEAR THE
TROUGH. SPEEDS SHOULD BE BELOW 20 KTS HOWEVER. ANOTHER LOW WILL DROP
SOUTHEAST ACROSS THE WESTERN/NORTHERN LAKES LATE SATURDAY NIGHT
HOWEVER AND WILL BRING A RENEWED PUSH OF COLDER AIR...WHICH COMBINED
WITH HIGH PRESSURE ONCE AGAIN MOVING SOUTH ACROSS THE PLAINS WILL
PRODUCE A PERIOD OF GUSTY NORTHWEST WINDS OF 30-35 KTS LATE SATURDAY
NIGHT THROUGH EARLY SUNDAY...HAVE MENTIONED GALES ON THE SOUTH HALF
SUNDAY MORNING. FREEZING SPRAY LIKELY DURING THIS TIME AS WELL...
THOUGH AIR TEMPS WILL BE A BIT WARMER THAN TONIGHT/FRIDAY MORNING.
HIGH PRESSURE THEN SPREADS ACROSS THE REGION AGAIN BY SUNDAY NIGHT
ALLOWING WINDS TO COME DOWN FAIRLY QUICKLY.
LONGER RANGE MODEL GUIDANCE DEVELOPS ANOTHER FAIRLY WEAK LOW WHICH
MOVES ACROSS THE LAKES TUESDAY...THOUGH NO DEEP STORMS THROUGH
MID-WEEK.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020...MIDNIGHT FRIDAY TO 10 AM FRIDAY.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 6 AM
FRIDAY.
SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 10 AM
FRIDAY.
SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 4 AM SATURDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
159 PM CST THU JAN 31 2013
.DISCUSSION...
1016 AM CST
FOR MORNING UPDATE...
HAVE MADE A FEW ADJUSTMENTS TO NEAR TERM FORECAST THIS MORNING... TO
BUMP POPS A BIT FOR OCCASIONAL SNOW SHOWERS. HAVE SEEN SOME ISOLATED
VISIBILITY REDUCTIONS LESS THAN A MILE AT TIMES THIS MORNING WITH A
FEW PLACES PICKING UP A DUSTING TO A TENTH OF AN INCH OR SO. HAVE
ALSO TOUCHED UP SKY COVER GRIDS...ACCOUNT SIGNIFICANT OPEN PATCHES
THIS MORNING ACROSS WEST/SOUTH PARTS OF CWA AND CONVECTIVE NATURE OF
EXPECTED CLOUD COVER THROUGH THE DAY.
MORNING ANALYSIS INDICATES DEEPENING SURFACE LOW CONTINUES TO TRACK
AWAY WELL TO OUR NORTHEAST ACROSS SOUTHERN QUEBEC...WITH COLD FRONT
TRAILING THROUGH NORTHERN INDIANA/CENTRAL ILLINOIS. COLD ARCTIC AIR
CONTINUES TO SPREAD SOUTHEAST ACROSS THE UPPER MIDWEST BEHIND THIS
FRONT...WITH SINGLE DIGIT AND SUB-ZERO TEMPS WIDESPREAD TO OUR
WEST/NORTHWEST. LOOKING ALOFT...RATHER STRONG MID-LEVEL SHORT WAVE
WAS NOTED OVER THE EASTERN DAKOTAS/MINNESOTA...AND THIS WAVE IS
PROGGED TO CONTINUE TO MOVE SOUTHEAST ACROSS OUR AREA THROUGH THIS
EVENING.
SCATTERED SNOW SHOWERS...SOME FAIRLY INTENSE WITH VISIBILITY
REDUCTIONS AND BRIEF MINOR ACCUMULATIONS...HAVE BEEN PREVALENT
ACROSS NORTHEAST IL THIS MORNING. THESE APPEAR TO BE HIGHLY DRIVEN
BY STEEP LOW LEVEL LAPSE RATES AS EVIDENCED BY 12Z ILX RAOB AND
RECENT AIRCRAFT AMDAR SOUNDINGS FROM ORD...WHICH DEPICT ADIABATIC
LOW LEVEL PROFILES FROM THE SURFACE UP TO ABOUT 850-800 MB. THIS
ALSO COINCIDES NICELY WITH THE -12 TO -18C FAVORED TEMPERATURE LAYER
FOR GOOD DENDRITIC GROWTH OF ICE CRYSTALS...OF WHICH HAVE BEEN
OBSERVED AT TIMES THIS MORNING. FORECAST SOUNDINGS FROM MORNING RUNS
OF THE WRF-NAM AND RAP MAINTAIN THESE STEEP LOW LEVEL LAPSE RATES
THROUGH THE DAY...COINCIDENT WITH BETTER MID/UPPER LEVEL FORCING
ASSOCIATED WITH THE APPROACH AND PASSAGE OF AFOREMENTIONED UPPER
MIDWEST SHORT WAVE. DEPSITE DRY ADVECTION OF ARCTIC AIR AND EVEN
THOUGH VIS SATELLITE IMAGERY IS NOT TOO IMPRESSIVE WITH CLOUD
COVER...SUSPECT THAT THIN STRATOCU WILL CONTINUE TO DEVELOP AND
PERHAPS INCREASE IN COVERAGE IN UNSTABLE LOW LEVEL THERMODYNAMIC
ENVIRONMENT...AND SHOULD BE ABLE TO SUSTAIN SNOW SHOWERS AND
FLURRIES WITH SUFFICIENT INTENSITY AT TIMES TO PRODUCE SOME MINOR
ACCUMS IN LOCALIZED AREAS. THEREFORE HAVE BUMPED POPS TO HIGHER
CHANCE CATEGORY...AND WORDED OCCASIONAL SNOW SHOWERS/FLURRIES WITH A
FEW TENTHS OF AN INCH POSSIBLE FOR MUCH OF NORTHERN 2/3 OR SO OF THE
CWA THROUGH THE DAY...AND THIS EVENING. MID-LEVEL TROUGH AXIS MOVES
ACROSS THE REGION LATE EVENING/MIDNIGHT TIME FRAME...AFTER WHICH
FORECAST SOUNDINGS DEPICT STRENGTHENING/LOWERING SUBSIDENCE
INVERSION WHICH SHOULD LIMIT FURTHER MEASURABLE PRECIP THREAT.
OTHERWISE...GOING FORECAST LOOKS GOOD THROUGH THIS AFTERNOON WITH
TEMPS NOT GOING ANYWHERE...AND COLD...BLUSTERY CONDITIONS.
RATZER
//PREV DISCUSSION...
340 AM CST
PRIMARY FORECAST CHALLENGE THIS MORNING IS CLOUD COVER AND ITS
IMPACT ON TEMPS THE NEXT SEVERAL DAYS AS WELL AS FLURRY/LIGHT SNOW
CHANCES.
PHASE ONE OF ARCTIC AIR HAS MOVED INTO THE AREA WITH PHASE 2 STILL
UPSTREAM AND POISED TO ARRIVE THIS AFTERNOON INTO TONIGHT. AS
ALLUDED TO LAST NIGHT GUIDANCE HAS BEEN FAR TOO COLD WITH TEMPS
OVERNIGHT INTO THE EARLY MORNING HOURS THIS MORNING...RUNNING IN
SOME CASES MORE THAN 5F TOO COLD AT 9Z THANKS TO THE CLOUD COVER AND
WIND. NO APPRECIABLE CLEARING IS ANTICIPATED PRIOR TO SUNRISE SO A
VERY SLOW (1-2F EVERY HOUR OR TWO) FALL SHOULD CONTINUE THROUGH
SUNRISE. WITH THE RE-ENFORCING SHOT OF COLD AIR ARRIVING THIS
AFTERNOON AND A GOOD DEAL OF CLOUD COVER/GUSTY NORTHWEST WINDS DONT
ANTICIPATE TEMPS TO REBOUND MUCH FROM EARLY MORNING READINGS WITH
TEMPS FAIRLY STEADY MOST OF THE DAY.
ALONG WITH THE ARRIVAL OF THE COLD AIR...WATER VAPOR IMAGERY SHOWS A
COUPLE OF VORTS UPSTREAM OVER THE NORTHERN PLAINS THAT WILL PIVOT
SOUTHEAST INTO THE AREA THIS AFTERNOON/EVENING. ICE CRYSTALS ARE
LIKELY ALREADY PRESENT IN THE STRATUS DECK GIVEN THE ARCTIC TEMPS SO
IT WILL REMAIN REMARKABLY EASY FOR LIGHT SNOW OR FLURRIES TO FALL
OUT OF THIS STRATUS DECK TODAY INTO TONIGHT...THOUGH ACCUMULATIONS
SHOULD BE MINIMAL FLAKES WILL LIKELY BE FLYING AT TIMES TODAY INTO
THIS EVENING.
CERTAINLY THE AIR MASS ADVECTING INTO THE AREA WILL BE VERY COLD
WITH EVENING SOUNDINGS UPSTREAM SAMPLING 850MB TEMPS NEAR
-20C...HOWEVER ITS NOT CLEAR HOW MUCH IF ANY CLEARING WILL TAKE
PLACE TONIGHT. IN THE ABSENCE OF CLEARING...THE WINDS AND CLOUDS
WOULD LIKELY KEEP TEMPS SEVERAL DEGREES WARMER THAN MOS LOWS AND
SUSPECT THAT CLOUDS WILL LINGER THROUGH THE NIGHT OVER EASTERN CWA
WITH SOME CLEAR LATE WEST. HAVE GENERALLY ADJUSTED LOW TEMPS UPWARD
SOME FROM PREVIOUS FORECAST AND GONE A BIT ABOVE THE WARMER MOS
GUIDANCE NUMBERS AS MODELS SUGGEST THAT LOW LEVEL CYCLONIC FLOW WILL
PERSIST MOST OF THE NIGHT RAISING SERIOUS DOUBTS ABOUT HOW MUCH
CLEARING WILL TAKE PLACE. IN ADDITION...THE AIR MASS THIS GO AROUND
WILL BE A COUPLE/FEW DEGREES MILDER AT 850MB THAN THE PREVIOUS ONE
AND WITH LITTLE/NO SNOW COVER MOST AREAS WOULD EXPECT LOWS TO BOTTOM
OUT NO COLDER THAN LAST GO AROUND AND IN ALL LIKELIHOOD A COUPLE
DEGREES WARMER (WELL LESS COLD). BASED ON THE FORECAST LOWS AND
EXPECTED WINDS LOOKS LIKE NC IL STANDS A REASONABLY GOOD CHANCE OF
REACHING THE -20F WIND CHILL ADVISORY CRITERIA AND SO HAVE GONE
AHEAD AND ISSUED THAT ALREADY THERE. FOR CHICAGO AREA AND POINTS
SOUTH AND EAST IT WILL UNDOUBTEDLY BE VERY COLD TONIGHT BUT APPEARS
UNLIKELY THAT THE -20F CRITERIA WILL BE MET FOR ANY LENGTH OF TIME
SO KEPT ADVISORY NORTH/WEST OF THESE AREAS.
COULD SEE SOME SUNSHINE THE FIRST HALF OF THE DAY ON FRIDAY BUT WILL
REMAIN QUITE COLD WITH CLOUDS ROLLING BACK IN IN THE AFTERNOON AS
FAST MOVING CLIPPER DIVES SE TOWARD THE AREA. VERY LITTLE CHANGE IN
MODEL GUIDANCE IN HANDLING THIS WAVE WITH SWATH OF ACCUMULATING VERY
FLUFFIFIED/HIGH RATION SNOW LIKELY ACROSS NORTHERN/CENTRAL ILLINOIS
FRIDAY NIGHT INTO SATURDAY MORNING. DESPITE LIMITED MOISTURE...HIGH
SNOW:LIQUID RATIOS COULD SUPPORT SOLID 2-3 INCH BAND OF SNOW...WITH
BEST PROJECTIONS AT THIS POINT PLACING THE HEAVIEST SNOW ALONG OR
SOUTH OF I-80. GIVEN HOW LOW AMPLITUDE THIS WAVE IS WOULD NOT BE A
STRETCH TO ENVISION LATER RUNS REFINING THE TRACK A BIT...BUT EVEN
WITH THAT IN MIND FELT FAIRLY COMFORTABLE CONTINUING THE TREND OF
BUMPING POPS UP A BIT HIGHER AGAIN THIS MORNING.
SEEMINGLY NEVER ENDING PARADE OF CLIPPERS ARE PROGGED TO CONTINUE TO
PIVOT AROUND THE BASE OF THE TROUGH HEADING INTO NEXT WEEK. THE 00Z
ECMWF HAS COME IN A BIT DEEPER AND FARTHER WEST WITH THE POLAR
VORTEX OVER THE REGION WHICH WOULD PLACE OUR CWA CLOSER TO THE COLD
SIDE OF THE PATH OF THESE CLIPPERS AND ALSO CLOSER TO POTENTIAL
LIGHT ACCUMULATING SNOWS. THE GEM...GFS...AND PREVIOUS ECMWF WERE
QUICKER TO WEAKEN THE POLAR VORTEX ALLOWING THE CLIPPERS TO PASS TO
OUR NORTH KEEPING US DRY WITH ALTERNATING BOUTS OF ABOVE AVERAGE
TEMPS AND SLIGHT COOL DOWNS WITH A TREND TOWARD SLIGHTLY WEAKER COOL
DOWNS WITH EACH WAVE. CONFIDENCE IS NOT TERRIBLY HIGH IN ANY ONE
SOLUTION AT THIS POINT BUT A TOWARD MODERATING TEMPS DEFINITELY
LOOKS REASONABLE HEADING INTO NEXT WEEK WITH LESS CERTAINTY
REGARDING PRECIP CHANCES.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* W WIND GUSTING 25-30 KT THROUGH THIS EVENING THEN GUSTS 15-20 KT
OVERNIGHT.
* PERIODS OF -SHSN THROUGH THE EARLY EVENING...HEAVIER BANDS COULD
DROP VSBY DOWN TO LESS THAN A MILE.
* HIGH END MVFR TO LOW END VFR CIGS EXPECTED THROUGH TONIGHT.
JEE
//DISCUSSION...UPDATED 18Z...
AN UPPER LEVEL SHORT WAVE TROUGH MOVED THROUGH THE DAKOTAS AND
PROVIDED FORCING FOR THE BANDS OF SNOW THE AREA SAW EARLIER THIS
MORNING. THE SHORTWAVE IS MOVING INTO IA WITH SHSN FORMING OVER
SOUTHERN WI. AS SUCH KEPT OCNL FLURRIES IN FOR THE TERMINALS
THROUGH 20Z AND EXPECTING MORE SUBSTANTIAL -SHSN AFTER 20Z. THEY
COULD DEVELOP A LITTLE LATER THAN INDICATED...WITH ARND A HALF
INCH OF SNOW PSBL. THE HEAVIER BANDS IN WI ARE ASSOCIATED WITH VSBY
OF LESS THAN 1 MILE...BUT WILL ADDRESS THOSE HEAVIER BANDS AS THEY
SET UP. OVERALL THINKING VSBYS WILL BE 4SM OR BETTER. EXPECTING
CIGS TO DROP A LITTLE WITH THE SNOW AS WELL TO ARND 020. A FEW
UPSTREAM OBS INDICATE 015 CIGS ARE PSBL SO WILL KEEP AN EYE ON HOW
THE LOWER CIGS PROGRESS.
WINDS WILL REMAIN W GUSTING TO 25 KT THROUGH THE MID AFTN WITH
GUSTS INCREASING TO 25-30KT THROUGH THE EVENING. WEST WINDS
GUSTING 15-20 KT ARE THEN EXPECTED OVERNIGHT UNDER THE TIGHTENED
PRESSURE GRADIENT. HIGH PRESSURE SINKS SOUTH TO THE EAST OF THE
TERMINALS ALLOWING SKIES TO SCATTER OUT TOMORROW.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN PRECIP FCST...MEDIUM CONFIDENCE IN TIMING AND
VSBY ASSOCIATED WITH -SN/-SHSN.
* HIGH CONFIDENCE IN ALL OTHER FCST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
12Z...
FRIDAY NIGHT...ACCUMULATING SNOW BECOMING LIKELY. MVFR BECOMING
IFR.
SATURDAY...MVFR WITH A CHANCE OF IFR SNOW SHOWERS...MAINLY IN THE
MORNING.
SUNDAY...MVFR.
MONDAY...VFR.
TUESDAY...VFR.
WEDNESDAY...VFR.
TRS
&&
.MARINE...
446 AM CST
DEEP LOW PRESSURE HAS MOVED FROM GEORGIAN BAY INTO SW QUEBEC
DURING LATE WED EVENING AND EARLY THIS MORNING AND WILL CONTINUE
TO MOVE FURTHER OFF TO THE NE. W TO WNW WINDS HAVE SLACKENED A BIT
AS A RESULT OR THE DECREASING PRESSURE GRADIENT OVER LAKE MI
THOUGH A FEW COASTAL OBSERVATION SITES ALONG THE IN AND FAR SW
LOWER MI SHORED CONTINUED TO MEASURE SOME 35-40KT GALE FORCE
GUSTS. WINDS WILL CONTINUE TO GRADUALLY DIMINISH DURING THE
PREDAWN AND EARLY MORNING HOURS BUT WILL REMAIN BRISK AS STRONG
HIGH PRESSURE CONTINUES TO BUILD SE FROM SOUTHERN SASKATCHEWAN
ACROSS THE NORTHERN AND CENTRAL PLAINS TODAY. WINDS WILL INCREASE
AND REACH GALES ON THE SOUTH PORTION OF THE LAKE BY MID AFTERNOON
AS A SURFACE TROUGH DROPS SE DOWN THE LAKE SPREADING AND ANOTHER
SURGE OF COLD AIR OVER THE REGION. GALE FORCE WINDS AND VERY COLD
AIR WILL RESULT IN FREEZING SPRAY ACROSS THE LAKE. GALES WILL
CONTINUE INTO LATE TONIGHT. BY FRIDAY MORNING A LARGE AREA OF
HIGH PRESSURE WILL BE CENTERED OVER IA AND MO. THE PRESSURE
GRADIENT DECREASES AS THE CENTER OF THE HIGH MOVES NEARER TO THE
AREA AND WINDS ON THE LAKE WILL DIMINISH TO BELOW GALE FORCE BY
FRI MORNING. NW WINDS GRADUALLY BACK TO SW DURING FRI AS THE
CENTER OF THE HIGH MOVES TO KY AND TN BY LATE IN THE AFTERNOON.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-
ILZ011...MIDNIGHT FRIDAY TO 10 AM FRIDAY.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 6 AM
FRIDAY.
SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 10 AM
FRIDAY.
SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 4 AM SATURDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1125 AM CST THU JAN 31 2013
.DISCUSSION...
1016 AM CST
FOR MORNING UPDATE...
HAVE MADE A FEW ADJUSTMENTS TO NEAR TERM FORECAST THIS MORNING... TO
BUMP POPS A BIT FOR OCCASIONAL SNOW SHOWERS. HAVE SEEN SOME ISOLATED
VISIBILITY REDUCTIONS LESS THAN A MILE AT TIMES THIS MORNING WITH A
FEW PLACES PICKING UP A DUSTING TO A TENTH OF AN INCH OR SO. HAVE
ALSO TOUCHED UP SKY COVER GRIDS...ACCOUNT SIGNIFICANT OPEN PATCHES
THIS MORNING ACROSS WEST/SOUTH PARTS OF CWA AND CONVECTIVE NATURE OF
EXPECTED CLOUD COVER THROUGH THE DAY.
MORNING ANALYSIS INDICATES DEEPENING SURFACE LOW CONTINUES TO TRACK
AWAY WELL TO OUR NORTHEAST ACROSS SOUTHERN QUEBEC...WITH COLD FRONT
TRAILING THROUGH NORTHERN INDIANA/CENTRAL ILLINOIS. COLD ARCTIC AIR
CONTINUES TO SPREAD SOUTHEAST ACROSS THE UPPER MIDWEST BEHIND THIS
FRONT...WITH SINGLE DIGIT AND SUB-ZERO TEMPS WIDESPREAD TO OUR
WEST/NORTHWEST. LOOKING ALOFT...RATHER STRONG MID-LEVEL SHORT WAVE
WAS NOTED OVER THE EASTERN DAKOTAS/MINNESOTA...AND THIS WAVE IS
PROGGED TO CONTINUE TO MOVE SOUTHEAST ACROSS OUR AREA THROUGH THIS
EVENING.
SCATTERED SNOW SHOWERS...SOME FAIRLY INTENSE WITH VISIBILITY
REDUCTIONS AND BRIEF MINOR ACCUMULATIONS...HAVE BEEN PREVALENT
ACROSS NORTHEAST IL THIS MORNING. THESE APPEAR TO BE HIGHLY DRIVEN
BY STEEP LOW LEVEL LAPSE RATES AS EVIDENCED BY 12Z ILX RAOB AND
RECENT AIRCRAFT AMDAR SOUNDINGS FROM ORD...WHICH DEPICT ADIABATIC
LOW LEVEL PROFILES FROM THE SURFACE UP TO ABOUT 850-800 MB. THIS
ALSO COINCIDES NICELY WITH THE -12 TO -18C FAVORED TEMPERATURE LAYER
FOR GOOD DENDRITIC GROWTH OF ICE CRYSTALS...OF WHICH HAVE BEEN
OBSERVED AT TIMES THIS MORNING. FORECAST SOUNDINGS FROM MORNING RUNS
OF THE WRF-NAM AND RAP MAINTAIN THESE STEEP LOW LEVEL LAPSE RATES
THROUGH THE DAY...COINCIDENT WITH BETTER MID/UPPER LEVEL FORCING
ASSOCIATED WITH THE APPROACH AND PASSAGE OF AFOREMENTIONED UPPER
MIDWEST SHORT WAVE. DEPSITE DRY ADVECTION OF ARCTIC AIR AND EVEN
THOUGH VIS SATELLITE IMAGERY IS NOT TOO IMPRESSIVE WITH CLOUD
COVER...SUSPECT THAT THIN STRATOCU WILL CONTINUE TO DEVELOP AND
PERHAPS INCREASE IN COVERAGE IN UNSTABLE LOW LEVEL THERMODYNAMIC
ENVIRONMENT...AND SHOULD BE ABLE TO SUSTAIN SNOW SHOWERS AND
FLURRIES WITH SUFFICIENT INTENSITY AT TIMES TO PRODUCE SOME MINOR
ACCUMS IN LOCALIZED AREAS. THEREFORE HAVE BUMPED POPS TO HIGHER
CHANCE CATEGORY...AND WORDED OCCASIONAL SNOW SHOWERS/FLURRIES WITH A
FEW TENTHS OF AN INCH POSSIBLE FOR MUCH OF NORTHERN 2/3 OR SO OF THE
CWA THROUGH THE DAY...AND THIS EVENING. MID-LEVEL TROUGH AXIS MOVES
ACROSS THE REGION LATE EVENING/MIDNIGHT TIME FRAME...AFTER WHICH
FORECAST SOUNDINGS DEPICT STRENGTHENING/LOWERING SUBSIDENCE
INVERSION WHICH SHOULD LIMIT FURTHER MEASURABLE PRECIP THREAT.
OTHERWISE...GOING FORECAST LOOKS GOOD THROUGH THIS AFTERNOON WITH
TEMPS NOT GOING ANYWHERE...AND COLD...BLUSTERY CONDITIONS.
RATZER
//PREV DISCUSSION...
340 AM CST
PRIMARY FORECAST CHALLENGE THIS MORNING IS CLOUD COVER AND ITS
IMPACT ON TEMPS THE NEXT SEVERAL DAYS AS WELL AS FLURRY/LIGHT SNOW
CHANCES.
PHASE ONE OF ARCTIC AIR HAS MOVED INTO THE AREA WITH PHASE 2 STILL
UPSTREAM AND POISED TO ARRIVE THIS AFTERNOON INTO TONIGHT. AS
ALLUDED TO LAST NIGHT GUIDANCE HAS BEEN FAR TOO COLD WITH TEMPS
OVERNIGHT INTO THE EARLY MORNING HOURS THIS MORNING...RUNNING IN
SOME CASES MORE THAN 5F TOO COLD AT 9Z THANKS TO THE CLOUD COVER AND
WIND. NO APPRECIABLE CLEARING IS ANTICIPATED PRIOR TO SUNRISE SO A
VERY SLOW (1-2F EVERY HOUR OR TWO) FALL SHOULD CONTINUE THROUGH
SUNRISE. WITH THE RE-ENFORCING SHOT OF COLD AIR ARRIVING THIS
AFTERNOON AND A GOOD DEAL OF CLOUD COVER/GUSTY NORTHWEST WINDS DONT
ANTICIPATE TEMPS TO REBOUND MUCH FROM EARLY MORNING READINGS WITH
TEMPS FAIRLY STEADY MOST OF THE DAY.
ALONG WITH THE ARRIVAL OF THE COLD AIR...WATER VAPOR IMAGERY SHOWS A
COUPLE OF VORTS UPSTREAM OVER THE NORTHERN PLAINS THAT WILL PIVOT
SOUTHEAST INTO THE AREA THIS AFTERNOON/EVENING. ICE CRYSTALS ARE
LIKELY ALREADY PRESENT IN THE STRATUS DECK GIVEN THE ARCTIC TEMPS SO
IT WILL REMAIN REMARKABLY EASY FOR LIGHT SNOW OR FLURRIES TO FALL
OUT OF THIS STRATUS DECK TODAY INTO TONIGHT...THOUGH ACCUMULATIONS
SHOULD BE MINIMAL FLAKES WILL LIKELY BE FLYING AT TIMES TODAY INTO
THIS EVENING.
CERTAINLY THE AIR MASS ADVECTING INTO THE AREA WILL BE VERY COLD
WITH EVENING SOUNDINGS UPSTREAM SAMPLING 850MB TEMPS NEAR
-20C...HOWEVER ITS NOT CLEAR HOW MUCH IF ANY CLEARING WILL TAKE
PLACE TONIGHT. IN THE ABSENCE OF CLEARING...THE WINDS AND CLOUDS
WOULD LIKELY KEEP TEMPS SEVERAL DEGREES WARMER THAN MOS LOWS AND
SUSPECT THAT CLOUDS WILL LINGER THROUGH THE NIGHT OVER EASTERN CWA
WITH SOME CLEAR LATE WEST. HAVE GENERALLY ADJUSTED LOW TEMPS UPWARD
SOME FROM PREVIOUS FORECAST AND GONE A BIT ABOVE THE WARMER MOS
GUIDANCE NUMBERS AS MODELS SUGGEST THAT LOW LEVEL CYCLONIC FLOW WILL
PERSIST MOST OF THE NIGHT RAISING SERIOUS DOUBTS ABOUT HOW MUCH
CLEARING WILL TAKE PLACE. IN ADDITION...THE AIR MASS THIS GO AROUND
WILL BE A COUPLE/FEW DEGREES MILDER AT 850MB THAN THE PREVIOUS ONE
AND WITH LITTLE/NO SNOW COVER MOST AREAS WOULD EXPECT LOWS TO BOTTOM
OUT NO COLDER THAN LAST GO AROUND AND IN ALL LIKELIHOOD A COUPLE
DEGREES WARMER (WELL LESS COLD). BASED ON THE FORECAST LOWS AND
EXPECTED WINDS LOOKS LIKE NC IL STANDS A REASONABLY GOOD CHANCE OF
REACHING THE -20F WIND CHILL ADVISORY CRITERIA AND SO HAVE GONE
AHEAD AND ISSUED THAT ALREADY THERE. FOR CHICAGO AREA AND POINTS
SOUTH AND EAST IT WILL UNDOUBTEDLY BE VERY COLD TONIGHT BUT APPEARS
UNLIKELY THAT THE -20F CRITERIA WILL BE MET FOR ANY LENGTH OF TIME
SO KEPT ADVISORY NORTH/WEST OF THESE AREAS.
COULD SEE SOME SUNSHINE THE FIRST HALF OF THE DAY ON FRIDAY BUT WILL
REMAIN QUITE COLD WITH CLOUDS ROLLING BACK IN IN THE AFTERNOON AS
FAST MOVING CLIPPER DIVES SE TOWARD THE AREA. VERY LITTLE CHANGE IN
MODEL GUIDANCE IN HANDLING THIS WAVE WITH SWATH OF ACCUMULATING VERY
FLUFFIFIED/HIGH RATION SNOW LIKELY ACROSS NORTHERN/CENTRAL ILLINOIS
FRIDAY NIGHT INTO SATURDAY MORNING. DESPITE LIMITED MOISTURE...HIGH
SNOW:LIQUID RATIOS COULD SUPPORT SOLID 2-3 INCH BAND OF SNOW...WITH
BEST PROJECTIONS AT THIS POINT PLACING THE HEAVIEST SNOW ALONG OR
SOUTH OF I-80. GIVEN HOW LOW AMPLITUDE THIS WAVE IS WOULD NOT BE A
STRETCH TO ENVISION LATER RUNS REFINING THE TRACK A BIT...BUT EVEN
WITH THAT IN MIND FELT FAIRLY COMFORTABLE CONTINUING THE TREND OF
BUMPING POPS UP A BIT HIGHER AGAIN THIS MORNING.
SEEMINGLY NEVER ENDING PARADE OF CLIPPERS ARE PROGGED TO CONTINUE TO
PIVOT AROUND THE BASE OF THE TROUGH HEADING INTO NEXT WEEK. THE 00Z
ECMWF HAS COME IN A BIT DEEPER AND FARTHER WEST WITH THE POLAR
VORTEX OVER THE REGION WHICH WOULD PLACE OUR CWA CLOSER TO THE COLD
SIDE OF THE PATH OF THESE CLIPPERS AND ALSO CLOSER TO POTENTIAL
LIGHT ACCUMULATING SNOWS. THE GEM...GFS...AND PREVIOUS ECMWF WERE
QUICKER TO WEAKEN THE POLAR VORTEX ALLOWING THE CLIPPERS TO PASS TO
OUR NORTH KEEPING US DRY WITH ALTERNATING BOUTS OF ABOVE AVERAGE
TEMPS AND SLIGHT COOL DOWNS WITH A TREND TOWARD SLIGHTLY WEAKER COOL
DOWNS WITH EACH WAVE. CONFIDENCE IS NOT TERRIBLY HIGH IN ANY ONE
SOLUTION AT THIS POINT BUT A TOWARD MODERATING TEMPS DEFINITELY
LOOKS REASONABLE HEADING INTO NEXT WEEK WITH LESS CERTAINTY
REGARDING PRECIP CHANCES.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* W WIND GUSTING 20-25KT THROUGH EARLY AFTERNOON...THEN GUSTING
25-30KT LATE AFTN AND THROUGH THE EVENING.
* SCATTERED -SN/FLURRIES PASSING OVER THE TERMINALS THROUGH 20Z
THEN A PERIOD OF -SHSN LATE THIS AFTN/EARLY EVENING.
* HIGH END MVFR TO LOW END VFR CIGS EXPECTED THROUGH TONIGHT.
JEE
//DISCUSSION...UPDATED 18Z...
AN UPPER LEVEL SHORT WAVE TROUGH MOVED THROUGH THE DAKOTAS AND
PROVIDED FORCING FOR THE BANDS OF SNOW THE AREA SAW EARLIER THIS
MORNING. THE SHORTWAVE IS MOVING INTO IA WITH SHSN FORMING OVER
SOUTHERN WI. AS SUCH KEPT OCNL FLURRIES IN FOR THE TERMINALS
THROUGH 20Z AND EXPECTING MORE SUBSTANTIAL -SHSN AFTER 20Z. THEY
COULD DEVELOP A LITTLE LATER THAN INDICATED...WITH ARND A HALF
INCH OF SNOW PSBL. THE HEAVIER BANDS IN WI ARE ASSOCIATED WITH VSBY
OF LESS THAN 1 MILE...BUT WILL ADDRESS THOSE HEAVIER BANDS AS THEY
SET UP. OVERALL THINKING VSBYS WILL BE 4SM OR BETTER. EXPECTING
CIGS TO DROP A LITTLE WITH THE SNOW AS WELL TO ARND 020. A FEW
UPSTREAM OBS INDICATE 015 CIGS ARE PSBL SO WILL KEEP AN EYE ON HOW
THE LOWER CIGS PROGRESS.
WINDS WILL REMAIN W GUSTING TO 25 KT THROUGH THE MID AFTN WITH
GUSTS INCREASING TO 25-30KT THROUGH THE EVENING. WEST WINDS
GUSTING 15-20 KT ARE THEN EXPECTED OVERNIGHT UNDER THE TIGHTENED
PRESSURE GRADIENT. HIGH PRESSURE SINKS SOUTH TO THE EAST OF THE
TERMINALS ALLOWING SKIES TO SCATTER OUT TOMORROW.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN PRECIP FCST...MEDIUM CONFIDENCE IN TIMING AND
VSBY ASSOCIATED WITH -SN/-SHSN.
* HIGH CONFIDENCE IN ALL OTHER FCST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
12Z...
FRIDAY NIGHT...ACCUMULATING SNOW BECOMING LIKELY. MVFR BECOMING
IFR.
SATURDAY...MVFR WITH A CHANCE OF IFR SNOW SHOWERS...MAINLY IN THE
MORNING.
SUNDAY...MVFR.
MONDAY...VFR.
TUESDAY...VFR.
WEDNESDAY...VFR.
TRS
&&
.MARINE...
446 AM CST
DEEP LOW PRESSURE HAS MOVED FROM GEORGIAN BAY INTO SW QUEBEC
DURING LATE WED EVENING AND EARLY THIS MORNING AND WILL CONTINUE
TO MOVE FURTHER OFF TO THE NE. W TO WNW WINDS HAVE SLACKENED A BIT
AS A RESULT OR THE DECREASING PRESSURE GRADIENT OVER LAKE MI
THOUGH A FEW COASTAL OBSERVATION SITES ALONG THE IN AND FAR SW
LOWER MI SHORED CONTINUED TO MEASURE SOME 35-40KT GALE FORCE
GUSTS. WINDS WILL CONTINUE TO GRADUALLY DIMINISH DURING THE
PREDAWN AND EARLY MORNING HOURS BUT WILL REMAIN BRISK AS STRONG
HIGH PRESSURE CONTINUES TO BUILD SE FROM SOUTHERN SASKATCHEWAN
ACROSS THE NORTHERN AND CENTRAL PLAINS TODAY. WINDS WILL INCREASE
AND REACH GALES ON THE SOUTH PORTION OF THE LAKE BY MID AFTERNOON
AS A SURFACE TROUGH DROPS SE DOWN THE LAKE SPREADING AND ANOTHER
SURGE OF COLD AIR OVER THE REGION. GALE FORCE WINDS AND VERY COLD
AIR WILL RESULT IN FREEZING SPRAY ACROSS THE LAKE. GALES WILL
CONTINUE INTO LATE TONIGHT. BY FRIDAY MORNING A LARGE AREA OF
HIGH PRESSURE WILL BE CENTERED OVER IA AND MO. THE PRESSURE
GRADIENT DECREASES AS THE CENTER OF THE HIGH MOVES NEARER TO THE
AREA AND WINDS ON THE LAKE WILL DIMINISH TO BELOW GALE FORCE BY
FRI MORNING. NW WINDS GRADUALLY BACK TO SW DURING FRI AS THE
CENTER OF THE HIGH MOVES TO KY AND TN BY LATE IN THE AFTERNOON.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-
ILZ011...MIDNIGHT FRIDAY TO 10 AM FRIDAY.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...3 PM
THURSDAY TO 6 AM FRIDAY.
SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 10 AM
FRIDAY.
SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 4 PM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1017 AM CST THU JAN 31 2013
.DISCUSSION...
1016 AM CST
FOR MORNING UPDATE...
HAVE MADE A FEW ADJUSTMENTS TO NEAR TERM FORECAST THIS MORNING... TO
BUMP POPS A BIT FOR OCCASIONAL SNOW SHOWERS. HAVE SEEN SOME ISOLATED
VISIBILITY REDUCTIONS LESS THAN A MILE AT TIMES THIS MORNING WITH A
FEW PLACES PICKING UP A DUSTING TO A TENTH OF AN INCH OR SO. HAVE
ALSO TOUCHED UP SKY COVER GRIDS...ACCOUNT SIGNIFICANT OPEN PATCHES
THIS MORNING ACROSS WEST/SOUTH PARTS OF CWA AND CONVECTIVE NATURE OF
EXPECTED CLOUD COVER THROUGH THE DAY.
MORNING ANALYSIS INDICATES DEEPENING SURFACE LOW CONTINUES TO TRACK
AWAY WELL TO OUR NORTHEAST ACROSS SOUTHERN QUEBEC...WITH COLD FRONT
TRAILING THROUGH NORTHERN INDIANA/CENTRAL ILLINOIS. COLD ARCTIC AIR
CONTINUES TO SPREAD SOUTHEAST ACROSS THE UPPER MIDWEST BEHIND THIS
FRONT...WITH SINGLE DIGIT AND SUB-ZERO TEMPS WIDESPREAD TO OUR
WEST/NORTHWEST. LOOKING ALOFT...RATHER STRONG MID-LEVEL SHORT WAVE
WAS NOTED OVER THE EASTERN DAKOTAS/MINNESOTA...AND THIS WAVE IS
PROGGED TO CONTINUE TO MOVE SOUTHEAST ACROSS OUR AREA THROUGH THIS
EVENING.
SCATTERED SNOW SHOWERS...SOME FAIRLY INTENSE WITH VISIBILITY
REDUCTIONS AND BRIEF MINOR ACCUMULATIONS...HAVE BEEN PREVALENT
ACROSS NORTHEAST IL THIS MORNING. THESE APPEAR TO BE HIGHLY DRIVEN
BY STEEP LOW LEVEL LAPSE RATES AS EVIDENCED BY 12Z ILX RAOB AND
RECENT AIRCRAFT AMDAR SOUNDINGS FROM ORD...WHICH DEPICT ADIABATIC
LOW LEVEL PROFILES FROM THE SURFACE UP TO ABOUT 850-800 MB. THIS
ALSO COINCIDES NICELY WITH THE -12 TO -18C FAVORED TEMPERATURE LAYER
FOR GOOD DENDRITIC GROWTH OF ICE CRYSTALS...OF WHICH HAVE BEEN
OBSERVED AT TIMES THIS MORNING. FORECAST SOUNDINGS FROM MORNING RUNS
OF THE WRF-NAM AND RAP MAINTAIN THESE STEEP LOW LEVEL LAPSE RATES
THROUGH THE DAY...COINCIDENT WITH BETTER MID/UPPER LEVEL FORCING
ASSOCIATED WITH THE APPROACH AND PASSAGE OF AFOREMENTIONED UPPER
MIDWEST SHORT WAVE. DEPSITE DRY ADVECTION OF ARCTIC AIR AND EVEN
THOUGH VIS SATELLITE IMAGERY IS NOT TOO IMPRESSIVE WITH CLOUD
COVER...SUSPECT THAT THIN STRATOCU WILL CONTINUE TO DEVELOP AND
PERHAPS INCREASE IN COVERAGE IN UNSTABLE LOW LEVEL THERMODYNAMIC
ENVIRONMENT...AND SHOULD BE ABLE TO SUSTAIN SNOW SHOWERS AND
FLURRIES WITH SUFFICIENT INTENSITY AT TIMES TO PRODUCE SOME MINOR
ACCUMS IN LOCALIZED AREAS. THEREFORE HAVE BUMPED POPS TO HIGHER
CHANCE CATEGORY...AND WORDED OCCASIONAL SNOW SHOWERS/FLURRIES WITH A
FEW TENTHS OF AN INCH POSSIBLE FOR MUCH OF NORTHERN 2/3 OR SO OF THE
CWA THROUGH THE DAY...AND THIS EVENING. MID-LEVEL TROUGH AXIS MOVES
ACROSS THE REGION LATE EVENING/MIDNIGHT TIME FRAME...AFTER WHICH
FORECAST SOUNDINGS DEPICT STRENGTHENING/LOWERING SUBSIDENCE
INVERSION WHICH SHOULD LIMIT FURTHER MEASURABLE PRECIP THREAT.
OTHERWISE...GOING FORECAST LOOKS GOOD THROUGH THIS AFTERNOON WITH
TEMPS NOT GOING ANYWHERE...AND COLD...BLUSTERY CONDITIONS.
RATZER
&&
.PREV DISCUSSION...
340 AM CST
PRIMARY FORECAST CHALLENGE THIS MORNING IS CLOUD COVER AND ITS
IMPACT ON TEMPS THE NEXT SEVERAL DAYS AS WELL AS FLURRY/LIGHT SNOW
CHANCES.
PHASE ONE OF ARCTIC AIR HAS MOVED INTO THE AREA WITH PHASE 2 STILL
UPSTREAM AND POISED TO ARRIVE THIS AFTERNOON INTO TONIGHT. AS
ALLUDED TO LAST NIGHT GUIDANCE HAS BEEN FAR TOO COLD WITH TEMPS
OVERNIGHT INTO THE EARLY MORNING HOURS THIS MORNING...RUNNING IN
SOME CASES MORE THAN 5F TOO COLD AT 9Z THANKS TO THE CLOUD COVER AND
WIND. NO APPRECIABLE CLEARING IS ANTICIPATED PRIOR TO SUNRISE SO A
VERY SLOW (1-2F EVERY HOUR OR TWO) FALL SHOULD CONTINUE THROUGH
SUNRISE. WITH THE RE-ENFORCING SHOT OF COLD AIR ARRIVING THIS
AFTERNOON AND A GOOD DEAL OF CLOUD COVER/GUSTY NORTHWEST WINDS DONT
ANTICIPATE TEMPS TO REBOUND MUCH FROM EARLY MORNING READINGS WITH
TEMPS FAIRLY STEADY MOST OF THE DAY.
ALONG WITH THE ARRIVAL OF THE COLD AIR...WATER VAPOR IMAGERY SHOWS A
COUPLE OF VORTS UPSTREAM OVER THE NORTHERN PLAINS THAT WILL PIVOT
SOUTHEAST INTO THE AREA THIS AFTERNOON/EVENING. ICE CRYSTALS ARE
LIKELY ALREADY PRESENT IN THE STRATUS DECK GIVEN THE ARCTIC TEMPS SO
IT WILL REMAIN REMARKABLY EASY FOR LIGHT SNOW OR FLURRIES TO FALL
OUT OF THIS STRATUS DECK TODAY INTO TONIGHT...THOUGH ACCUMULATIONS
SHOULD BE MINIMAL FLAKES WILL LIKELY BE FLYING AT TIMES TODAY INTO
THIS EVENING.
CERTAINLY THE AIR MASS ADVECTING INTO THE AREA WILL BE VERY COLD
WITH EVENING SOUNDINGS UPSTREAM SAMPLING 850MB TEMPS NEAR
-20C...HOWEVER ITS NOT CLEAR HOW MUCH IF ANY CLEARING WILL TAKE
PLACE TONIGHT. IN THE ABSENCE OF CLEARING...THE WINDS AND CLOUDS
WOULD LIKELY KEEP TEMPS SEVERAL DEGREES WARMER THAN MOS LOWS AND
SUSPECT THAT CLOUDS WILL LINGER THROUGH THE NIGHT OVER EASTERN CWA
WITH SOME CLEAR LATE WEST. HAVE GENERALLY ADJUSTED LOW TEMPS UPWARD
SOME FROM PREVIOUS FORECAST AND GONE A BIT ABOVE THE WARMER MOS
GUIDANCE NUMBERS AS MODELS SUGGEST THAT LOW LEVEL CYCLONIC FLOW WILL
PERSIST MOST OF THE NIGHT RAISING SERIOUS DOUBTS ABOUT HOW MUCH
CLEARING WILL TAKE PLACE. IN ADDITION...THE AIR MASS THIS GO AROUND
WILL BE A COUPLE/FEW DEGREES MILDER AT 850MB THAN THE PREVIOUS ONE
AND WITH LITTLE/NO SNOW COVER MOST AREAS WOULD EXPECT LOWS TO BOTTOM
OUT NO COLDER THAN LAST GO AROUND AND IN ALL LIKELIHOOD A COUPLE
DEGREES WARMER (WELL LESS COLD). BASED ON THE FORECAST LOWS AND
EXPECTED WINDS LOOKS LIKE NC IL STANDS A REASONABLY GOOD CHANCE OF
REACHING THE -20F WIND CHILL ADVISORY CRITERIA AND SO HAVE GONE
AHEAD AND ISSUED THAT ALREADY THERE. FOR CHICAGO AREA AND POINTS
SOUTH AND EAST IT WILL UNDOUBTEDLY BE VERY COLD TONIGHT BUT APPEARS
UNLIKELY THAT THE -20F CRITERIA WILL BE MET FOR ANY LENGTH OF TIME
SO KEPT ADVISORY NORTH/WEST OF THESE AREAS.
COULD SEE SOME SUNSHINE THE FIRST HALF OF THE DAY ON FRIDAY BUT WILL
REMAIN QUITE COLD WITH CLOUDS ROLLING BACK IN IN THE AFTERNOON AS
FAST MOVING CLIPPER DIVES SE TOWARD THE AREA. VERY LITTLE CHANGE IN
MODEL GUIDANCE IN HANDLING THIS WAVE WITH SWATH OF ACCUMULATING VERY
FLUFFIFIED/HIGH RATION SNOW LIKELY ACROSS NORTHERN/CENTRAL ILLINOIS
FRIDAY NIGHT INTO SATURDAY MORNING. DESPITE LIMITED MOISTURE...HIGH
SNOW:LIQUID RATIOS COULD SUPPORT SOLID 2-3 INCH BAND OF SNOW...WITH
BEST PROJECTIONS AT THIS POINT PLACING THE HEAVIEST SNOW ALONG OR
SOUTH OF I-80. GIVEN HOW LOW AMPLITUDE THIS WAVE IS WOULD NOT BE A
STRETCH TO ENVISION LATER RUNS REFINING THE TRACK A BIT...BUT EVEN
WITH THAT IN MIND FELT FAIRLY COMFORTABLE CONTINUING THE TREND OF
BUMPING POPS UP A BIT HIGHER AGAIN THIS MORNING.
SEEMINGLY NEVER ENDING PARADE OF CLIPPERS ARE PROGGED TO CONTINUE TO
PIVOT AROUND THE BASE OF THE TROUGH HEADING INTO NEXT WEEK. THE 00Z
ECMWF HAS COME IN A BIT DEEPER AND FARTHER WEST WITH THE POLAR
VORTEX OVER THE REGION WHICH WOULD PLACE OUR CWA CLOSER TO THE COLD
SIDE OF THE PATH OF THESE CLIPPERS AND ALSO CLOSER TO POTENTIAL
LIGHT ACCUMULATING SNOWS. THE GEM...GFS...AND PREVIOUS ECMWF WERE
QUICKER TO WEAKEN THE POLAR VORTEX ALLOWING THE CLIPPERS TO PASS TO
OUR NORTH KEEPING US DRY WITH ALTERNATING BOUTS OF ABOVE AVERAGE
TEMPS AND SLIGHT COOL DOWNS WITH A TREND TOWARD SLIGHTLY WEAKER COOL
DOWNS WITH EACH WAVE. CONFIDENCE IS NOT TERRIBLY HIGH IN ANY ONE
SOLUTION AT THIS POINT BUT A TOWARD MODERATING TEMPS DEFINITELY
LOOKS REASONABLE HEADING INTO NEXT WEEK WITH LESS CERTAINTY
REGARDING PRECIP CHANCES.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* W WIND GUSTING 20-25KT THROUGH EARLY AFTERNOON...THEN GUSTING
25-30KT LATE AFTN AND THROUGH THE EVENING.
* SCATTERED -SN/FLURRIES PASSING OVER THE TERMINALS THROUGH 20Z
THEN A PERIOD OF -SHSN LATE THIS AFTN/EARLY EVENING.
* HIGH END MVFR TO LOW END VFR CIGS EXPECTED.
JEE
//DISCUSSION...UPDATED 12Z...
ANOTHER MID LEVEL SHORT WAVE TROUGH WAS MOVING OVER NORTHERN WI...
CENTRAL MN AND SE ND EARLY THIS MORNING CONTINUING TO GENERATE
LIGHT SNOW ACROSS THE AREA. BANDS OF SOMEWHAT HEAVER SNOW
OCCASIONALLY PASS OVER ORD AND/OR MDW AND BRIEFLY DROP VISIBILITY
DOWN TO 3-5SM. THIS SNOW WILL PERSIST UNTIL THE TROUGH AXIS PASSES
BY...WHICH IS EXPECTED IN THE 13Z TO 15Z WINDOW. SOME FLURRIES MAY
LINGER THE REST OF THE MORNING BUT WILL NOT BE A RESTRICTION TO
VISIBILITY.
ANOTHER SHORT WAVE TROUGH...CURRENTLY OVER NORTHERN ND AND
MN...WILL CONTINUE TO DROP ESE THIS MORNING AND MOVE TO OVER SE
WI...NORTHERN IL AND SOUTHERN IA BY 00Z. SNOWFALL OF ANY
SIGNIFICANCE FROM THIS DISTURBANCE IS EXPECTED TO REMAIN MAINLY TO
THE NW AND N OF THE CHI AREA WITH JUST MORE FLURRIES...AND
POSSIBLY SOME VERY LIGHT SNOW SHOWERS...FOR THE LOCAL AREA DURING
THE LATE AFTERNOON AND EARLY EVENING.
WINDS SETTLED DOWN DURING THE OVERNIGHT THE TIGHTER PRESSURE
GRADIENT SHIFTED E. THE GRADIENT TIGHTENS AGAIN THIS MORNING WITH
W-WNW WINDS GUSTING BACK UP INTO 25-30KT RANGE BY LATE MORNING AS
THE HIGH PRESSURE RIDGE THAT EXTENDS S ACROSS SW SASKATCHEWAN SE
TO THE CENTRAL PLAINS GRADUALLY MOVES SE. WITH THE HIGH
CONTINUING TO THE SE THIS EVENING AND OVERNIGHT WINDS WILL DROP
OFF AGAIN AS THE GRADIENT ONCE AGAIN RELAXES.
MODEL RH FIELDS OF THE LOWER LAYERS SUGGEST THE CURRENT MVFR
CEILINGS WILL RISE TO VFR THIS MORNING THEN DROP BACK TO MVFR THIS
AFTERNOON.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN PRECIP FCST...MEDIUM CONFIDENCE IN VSBY
ASSOCIATED WITH -SN.
* HIGH CONFIDENCE IN ALL OTHER FCST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
12Z...
FRIDAY NIGHT...ACCUMULATING SNOW BECOMING LIKELY. MVFR BECOMING
IFR.
SATURDAY...MVFR WITH A CHANCE OF IFR SNOW SHOWERS...MAINLY IN THE
MORNING.
SUNDAY...MVFR.
MONDAY...VFR.
TUESDAY...VFR.
WEDNESDAY...VFR.
TRS
&&
.MARINE...
446 AM CST
DEEP LOW PRESSURE HAS MOVED FROM GEORGIAN BAY INTO SW QUEBEC
DURING LATE WED EVENING AND EARLY THIS MORNING AND WILL CONTINUE
TO MOVE FURTHER OFF TO THE NE. W TO WNW WINDS HAVE SLACKENED A BIT
AS A RESULT OR THE DECREASING PRESSURE GRADIENT OVER LAKE MI
THOUGH A FEW COASTAL OBSERVATION SITES ALONG THE IN AND FAR SW
LOWER MI SHORED CONTINUED TO MEASURE SOME 35-40KT GALE FORCE
GUSTS. WINDS WILL CONTINUE TO GRADUALLY DIMINISH DURING THE
PREDAWN AND EARLY MORNING HOURS BUT WILL REMAIN BRISK AS STRONG
HIGH PRESSURE CONTINUES TO BUILD SE FROM SOUTHERN SASKATCHEWAN
ACROSS THE NORTHERN AND CENTRAL PLAINS TODAY. WINDS WILL INCREASE
AND REACH GALES ON THE SOUTH PORTION OF THE LAKE BY MID AFTERNOON
AS A SURFACE TROUGH DROPS SE DOWN THE LAKE SPREADING AND ANOTHER
SURGE OF COLD AIR OVER THE REGION. GALE FORCE WINDS AND VERY COLD
AIR WILL RESULT IN FREEZING SPRAY ACROSS THE LAKE. GALES WILL
CONTINUE INTO LATE TONIGHT. BY FRIDAY MORNING A LARGE AREA OF
HIGH PRESSURE WILL BE CENTERED OVER IA AND MO. THE PRESSURE
GRADIENT DECREASES AS THE CENTER OF THE HIGH MOVES NEARER TO THE
AREA AND WINDS ON THE LAKE WILL DIMINISH TO BELOW GALE FORCE BY
FRI MORNING. NW WINDS GRADUALLY BACK TO SW DURING FRI AS THE
CENTER OF THE HIGH MOVES TO KY AND TN BY LATE IN THE AFTERNOON.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-
ILZ011...MIDNIGHT FRIDAY TO 10 AM FRIDAY.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...3 PM
THURSDAY TO 6 AM FRIDAY.
SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 10 AM
FRIDAY.
SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 4 PM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1119 AM MST THU JAN 31 2013
.UPDATE...
ISSUED AT 1115 AM MST THU JAN 31 2013
UPDATED TEMPERATURES FOR TODAY. COLD AIR IS MAKING ITS IMPACT
ESPECIALLY IN THE EASTERN FA WITH MCK TEMPERATURES STEADILY
FALLING ABOUT A DEGREE PER HOUR. EXPECT THAT TREND TO WORK ITS WAY
SLOWLY WEST ACROSS THE FA. ALSO LOWERED TONIGHT AND FRIDAY
TEMPERATURES.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 412 AM MST THU JAN 31 2013
FORECAST PROBLEMS WILL PROBLEMATIC TEMPERATURE FORECAST INTO TONIGHT
AND HOW MUCH TO WARM UP THE HIGH TEMPERATURES INTO SATURDAY.
SATELLITE SHOWING A BROAD UPPER TROUGH OVER THE TROUGH OVER THE
WESTERN AND CENTRAL PACIFIC WITH A RIDGE ALONG THE WEST COAST OF
NORTH AMERICA. A COUPLE OF SYSTEMS COMING INTO THE RIDGE ARE BEATING
IT DOWN. A STRONG AND COLD SYSTEM IS DIGGING INTO THE NORTH CENTRAL
PORTION OF THE COUNTRY. VERY COLD AIR MASS HAS MOVED FURTHER SOUTH
FROM YESTERDAY AND IS NOT TOO FAR NORTH AND EAST OF OUR AREA.
MODELS INITIALIZED WELL AT JET LEVEL WITH THE CANADIAN...GFS...AND
NAM DOING THE BEST. MODELS INITIALIZED WELL AT MID LEVELS WITH THE
GFS...CANADIAN...AND NAM DOING SLIGHTLY BETTER. LARGER SCALE MODELS
DO NOT HAVE THE BACKDOOR COLD FRONT FAR ENOUGH SOUTH AND WEST BY
06Z...OH SURPRISE. THE RUC HAS CONTINUED TO GET BETTER AS THE
NIGHT HAS PROGRESSED. OUTSIDE OF THE RUC ON THE LOW LEVEL THERMAL
FIELD...THE ECMWF AND GFS WERE DOING A LITTLE BETTER THAN THE UKMET
AND NAM.
TODAY/TONIGHT...VERY THICK CLOUD COVER HAS SPREAD OVER THE AREA
THROUGH THE NIGHT. WHAT THIS HAS DONE HAS PREVENTED ANY FALL OF THE
TEMPERATURES AND IN FACT HAS CAUSED THE TEMPERATURES TO RISE SOME.
NWP OUTPUT MUST BE UNDERDOING THIS CLOUD COVER AND IS TOO COOL WITH
TEMPERATURES. THIS CLOUD COVER IS BEING CAUSED BY STRONG MID TO
UPPER LEVEL JET. SOUNDINGS AND PLAN VIEW RELATIVE HUMIDITY PLOTS SHOW
THIS CLOUD COVER LASTING MOST OF THE DAY...ESPECIALLY IN THE
NORTHEAST PORTION.
BACKDOOR COLD FRONT WITH VERY COLD AIR BEHIND IT HAS BEEN MOVING
STEADILY TOWARD THE AREA THROUGH THE NIGHT AND IS NOT THAT FAR
AWAY. RUC IS CATCHING ONTO THIS AT THIS TIME. INITIALLY WAS GOING TO
CUT HIGH TEMPERATURES FROM GOING FORECAST BUT CLOUD COVER HAS
COMPLICATED THAT. SO WILL BE STARTING MUCH WARMER THAN WHAT MOST OF
THE MODELS SAY. FRONT SAGS ACROSS THE AREA THROUGH THE DAY WITH
SOME LOCATIONS IN THE NORTHEAST HALF TO TWO THIRDS REACHING THEIR
MAX BY 18Z. SO COMBINING REALITY AND THE RUC ADJUSTED MAX
TEMPERATURES UP BUT HAVE EXTREMELY LOW CONFIDENCE ABOUT THIS. DID
NOT GOES AS WARM AS IT BECAUSE OF THE CLOUD COVER. HRRR WOULD
INDICATE HIGH TEMPERATURES ABOUT 10 DEGREES WARMER IN THE SOUTHWEST
PORTION OF THE AREA THAT WHAT I HAVE.
LEFT FRONT QUADRANT OF INCOMING JET WILL CONTINUE TO AFFECT THE
NORTHEAST HALF TO TWO THIRDS OF THE AREA INTO EARLY AFTERNOON.
SEVERAL STATIONS HAVE REPORTED BRIEF PERIODS OF FLURRIES. ALL MODEL
OUTPUT AGREES IN PLACING LIGHT QPF IN THE ABOVE MENTIONED AREA. SREF
PROBABILITIES AGREE WITH THAT. IT MAKES SENSE WITH THE JET...
MESOSCALE FORCING AND LAPSE RATES IN PLACE. HOWEVER...DRIER AIR
IN THE LOWEST LAYERS. SO INTRODUCED SCATTERED FLURRIES THROUGH
MIDDAY WHEN THE FORCING AND MOISTURE LEAVE.
PROBLEMATIC MIN FORECAST AS WELL. WINDS SHIFT AROUND TO A SOUTH
DIRECTION PRETTY QUICKLY. NAM IS THE MOST AGGRESSIVE BUT IS
SUPPORTED BY OTHER MODEL OUTPUT IN BRINGING STRATUS AND FOG DURING
THE LATE EVENING AND OVERNIGHT HOURS. THIS IS AS THE COLD FRONT
RETREATS BACK AS A WARM FRONT AND ALL THE MODELS ARE VERY SIMILAR
IN DOING IT. MINS WILL PROBABLY BE REACHED IN THE EVENING
ESPECIALLY IN THE WEST AND POSSIBLY IN THE SOUTH AND A NON-DIURNAL
CURVE WILL HAVE TO BE INTRODUCED. BELIEVE MODELS ARE TOO COOL AND
WENT ABOVE THE GUIDANCE.
06Z NAM WAS MUCH MORE ROBUST IN BRINGING IN THE STRATUS AND FOG. NAM
HAS BEEN SHOWING THIS FOR A FEW DAYS PLUS THOSE SOUTH WINDS WILL BE
BLOWING ACROSS A SNOW FIELD. SO EXPANDED THE PATCHY FOG THAT WAS IN
THERE.
FRIDAY/FRIDAY NIGHT...STRATUS AND FOG GET PUSHED EAST PRETTY FAST BY
THE STRENGTHENING DOWNSLOPE WINDS. THERE MAY BE SOME HIGHER LEVEL
CLOUD COVER AROUND. INCOMING SHORTWAVE TROUGH IN NORTHWEST FLOW
ALOFT WILL PUSH A WEAK FRONT OR SURFACE TROUGH THROUGH LATER IN THE
DAY BUT IT LOOKS LIKE WINDS WILL BE FROM A DOWNSLOPE DIRECTION. SO
ENDED UP RAISING THE MAXES A LITTLE.
LEFT FRONT QUADRANT OF JET WILL AFFECT THE NORTHERN PORTION OF THE
AREA DURING THE NIGHT AS WELL AS THE ABOVE MENTIONED SHORTWAVE
TROUGH...WHICH HAPPENS TO BE THE ONE TOPPING THE RIDGE RIGHT NOW
NEAR WESTERN CANADA. ALL MODELS AGREE THAT THIS SYSTEM WILL HAVE
A VERY STRONG PV ANOMALY AS WELL. MODELS DO NOT SHOW A LOT OF
MOISTURE IN THE COLUMN BUT STRENGTH OF SYSTEM SHOULD COMPENSATE FOR
THAT. SO EXPANDED THE SPRINKLES AND FLURRIES OVER A LARGER AREA AND
THROUGH THE EVENING HOURS.
SATURDAY/SATURDAY NIGHT...RIDGING AND DRYING ALOFT PUSH INTO THE
AREA FOR SATURDAY. SO WILL HAVE PLENTY OF SUN ALONG WITH STRONG
DOWNSLOPE WINDS. SO RAISED MAXES MORE AND I MAY NOT BE WARM ENOUGH
AS I BELIEVE MODELS ARE TOO COOL.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 246 AM MST THU JAN 31 2013
MODEL AGREEMENT IS FAIRLY GOOD IN THE EXTENDED FORECAST. ALL
SOLUTIONS ARE POINTING TO A TAME WEATHER PATTERN WITHOUT ANY BIG
WEATHER CHANGES OR PRECIPITATION CHANCES. A SYSTEM WILL MOVE ACROSS
THE NORTHERN PLAINS AND GREAT LAKES ON MONDAY...BRINGING ONLY A WIND
SHIFT AND TEMPERATURES A DEGREE OR TWO COOLER. AFTER THAT...A RIDGE
OF HIGH PRESSURE BUILDS BACK IN FROM THE WEST.
TEMPERATURES SHOULD BE WELL ABOVE NORMAL FOR THIS TIME OF YEAR
THROUGHOUT THE EXTENDED FORECAST. HIGHS SHOULD BE IN THE 50S FOR
SUNDAY THROUGH TUESDAY...WITH HIGHS CLIMBING INTO THE 60S BY THE
MIDDLE OF NEXT WEEK. GUIDANCE HAS PULLED BACK SOMEWHAT FOR HIGH
TEMPERATURES ON SUNDAY BUT STILL THINK TEMPERATURES NEARING 60 FOR
EASTERN COLORADO IS NOT OUT OF THE QUESTION.
THE ONLY OTHER CONCERN FOR THE EXTENDED FORECAST WAS LOW
TEMPERATURES. THE INITIALIZATION PROCEDURE INPUT LOW TEMPERATURES
THAT WERE LIKELY TOO WARM. CONSIDERING THE ONGOING DROUGHT
CONDITIONS AND MEX AND ECE GUIDANCE SUGGESTING TEMPERATURES MUCH
LOWER THAN THE INITIALIZATION...HAVE LOWERED LOW TEMPERATURES A
DEGREE OR TWO. GUIDANCE IS ALTERED BY CLIMATOLOGICAL DATA SO THIS
COULD BE THE REASON MEX AND ECE GUIDANCE IS BEING HELD DOWN
SOMEWHAT. HOWEVER...THE HIGHER LOW TEMPS SEEMED A LITTLE
UNREASONABLE WITH CLEAR SKIES AND LIGHT WINDS THROUGHOUT THE
EXTENDED PERIOD.
THANKS TO ALL FOR THE COLLABORATION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1040 AM MST THU JAN 31 2013
VFR TO MVFR CONDITIONS WILL PERSIST THROUGH THE TAF PERIOD AT BOTH
GLD AND MCK. FOR THE REST OF THE DAY...SOME BREEZY WINDS AND
CLEARING SKIES AT GLD...WHILE CURRENT CLOUDS WILL STICK AROUND AT
MCK. THIS EVENING A BACKDOOR COLD FRONT WILL PUSH FROM NORTHEAST TO
SOUTHWEST...ARRIVING AT MCK AROUND 22Z. THIS WILL SHIFT
WINDS...THOUGH WIND SPEEDS AT BOTH TERMINALS WILL BE LIGHT /LESS
THAN 10KTS/ THROUGHOUT THE OVERNIGHT PERIOD. SOME PATCHY FOG AND LOW
STRATUS CLOUDS ARE EXPECTED...WITH CONDITIONS MAINLY REMAINING MVFR.
BEST CHANCE FOR FOG WILL BE AT GLD...THOUGH IF FOG REACHES MCK IT
MAY STICK AROUND INTO THE MID-MORNING HOURS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...032
SHORT TERM...BULLER
LONG TERM...RRH
AVIATION...JJM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1040 AM MST THU JAN 31 2013
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 412 AM MST THU JAN 31 2013
FORECAST PROBLEMS WILL PROBLEMATIC TEMPERATURE FORECAST INTO TONIGHT
AND HOW MUCH TO WARM UP THE HIGH TEMPERATURES INTO SATURDAY.
SATELLITE SHOWING A BROAD UPPER TROUGH OVER THE TROUGH OVER THE
WESTERN AND CENTRAL PACIFIC WITH A RIDGE ALONG THE WEST COAST OF
NORTH AMERICA. A COUPLE OF SYSTEMS COMING INTO THE RIDGE ARE BEATING
IT DOWN. A STRONG AND COLD SYSTEM IS DIGGING INTO THE NORTH CENTRAL
PORTION OF THE COUNTRY. VERY COLD AIR MASS HAS MOVED FURTHER SOUTH
FROM YESTERDAY AND IS NOT TOO FAR NORTH AND EAST OF OUR AREA.
MODELS INITIALIZED WELL AT JET LEVEL WITH THE CANADIAN...GFS...AND
NAM DOING THE BEST. MODELS INITIALIZED WELL AT MID LEVELS WITH THE
GFS...CANADIAN...AND NAM DOING SLIGHTLY BETTER. LARGER SCALE MODELS
DO NOT HAVE THE BACKDOOR COLD FRONT FAR ENOUGH SOUTH AND WEST BY
06Z...OH SURPRISE. THE RUC HAS CONTINUED TO GET BETTER AS THE
NIGHT HAS PROGRESSED. OUTSIDE OF THE RUC ON THE LOW LEVEL THERMAL
FIELD...THE ECMWF AND GFS WERE DOING A LITTLE BETTER THAN THE UKMET
AND NAM.
TODAY/TONIGHT...VERY THICK CLOUD COVER HAS SPREAD OVER THE AREA
THROUGH THE NIGHT. WHAT THIS HAS DONE HAS PREVENTED ANY FALL OF THE
TEMPERATURES AND IN FACT HAS CAUSED THE TEMPERATURES TO RISE SOME.
NWP OUTPUT MUST BE UNDERDOING THIS CLOUD COVER AND IS TOO COOL WITH
TEMPERATURES. THIS CLOUD COVER IS BEING CAUSED BY STRONG MID TO
UPPER LEVEL JET. SOUNDINGS AND PLAN VIEW RELATIVE HUMIDITY PLOTS SHOW
THIS CLOUD COVER LASTING MOST OF THE DAY...ESPECIALLY IN THE
NORTHEAST PORTION.
BACKDOOR COLD FRONT WITH VERY COLD AIR BEHIND IT HAS BEEN MOVING
STEADILY TOWARD THE AREA THROUGH THE NIGHT AND IS NOT THAT FAR
AWAY. RUC IS CATCHING ONTO THIS AT THIS TIME. INITIALLY WAS GOING TO
CUT HIGH TEMPERATURES FROM GOING FORECAST BUT CLOUD COVER HAS
COMPLICATED THAT. SO WILL BE STARTING MUCH WARMER THAN WHAT MOST OF
THE MODELS SAY. FRONT SAGS ACROSS THE AREA THROUGH THE DAY WITH
SOME LOCATIONS IN THE NORTHEAST HALF TO TWO THIRDS REACHING THEIR
MAX BY 18Z. SO COMBINING REALITY AND THE RUC ADJUSTED MAX
TEMPERATURES UP BUT HAVE EXTREMELY LOW CONFIDENCE ABOUT THIS. DID
NOT GOES AS WARM AS IT BECAUSE OF THE CLOUD COVER. HRRR WOULD
INDICATE HIGH TEMPERATURES ABOUT 10 DEGREES WARMER IN THE SOUTHWEST
PORTION OF THE AREA THAT WHAT I HAVE.
LEFT FRONT QUADRANT OF INCOMING JET WILL CONTINUE TO AFFECT THE
NORTHEAST HALF TO TWO THIRDS OF THE AREA INTO EARLY AFTERNOON.
SEVERAL STATIONS HAVE REPORTED BRIEF PERIODS OF FLURRIES. ALL MODEL
OUTPUT AGREES IN PLACING LIGHT QPF IN THE ABOVE MENTIONED AREA. SREF
PROBABILITIES AGREE WITH THAT. IT MAKES SENSE WITH THE JET...
MESOSCALE FORCING AND LAPSE RATES IN PLACE. HOWEVER...DRIER AIR
IN THE LOWEST LAYERS. SO INTRODUCED SCATTERED FLURRIES THROUGH
MIDDAY WHEN THE FORCING AND MOISTURE LEAVE.
PROBLEMATIC MIN FORECAST AS WELL. WINDS SHIFT AROUND TO A SOUTH
DIRECTION PRETTY QUICKLY. NAM IS THE MOST AGGRESSIVE BUT IS
SUPPORTED BY OTHER MODEL OUTPUT IN BRINGING STRATUS AND FOG DURING
THE LATE EVENING AND OVERNIGHT HOURS. THIS IS AS THE COLD FRONT
RETREATS BACK AS A WARM FRONT AND ALL THE MODELS ARE VERY SIMILAR
IN DOING IT. MINS WILL PROBABLY BE REACHED IN THE EVENING
ESPECIALLY IN THE WEST AND POSSIBLY IN THE SOUTH AND A NON-DIURNAL
CURVE WILL HAVE TO BE INTRODUCED. BELIEVE MODELS ARE TOO COOL AND
WENT ABOVE THE GUIDANCE.
06Z NAM WAS MUCH MORE ROBUST IN BRINGING IN THE STRATUS AND FOG. NAM
HAS BEEN SHOWING THIS FOR A FEW DAYS PLUS THOSE SOUTH WINDS WILL BE
BLOWING ACROSS A SNOW FIELD. SO EXPANDED THE PATCHY FOG THAT WAS IN
THERE.
FRIDAY/FRIDAY NIGHT...STRATUS AND FOG GET PUSHED EAST PRETTY FAST BY
THE STRENGTHENING DOWNSLOPE WINDS. THERE MAY BE SOME HIGHER LEVEL
CLOUD COVER AROUND. INCOMING SHORTWAVE TROUGH IN NORTHWEST FLOW
ALOFT WILL PUSH A WEAK FRONT OR SURFACE TROUGH THROUGH LATER IN THE
DAY BUT IT LOOKS LIKE WINDS WILL BE FROM A DOWNSLOPE DIRECTION. SO
ENDED UP RAISING THE MAXES A LITTLE.
LEFT FRONT QUADRANT OF JET WILL AFFECT THE NORTHERN PORTION OF THE
AREA DURING THE NIGHT AS WELL AS THE ABOVE MENTIONED SHORTWAVE
TROUGH...WHICH HAPPENS TO BE THE ONE TOPPING THE RIDGE RIGHT NOW
NEAR WESTERN CANADA. ALL MODELS AGREE THAT THIS SYSTEM WILL HAVE
A VERY STRONG PV ANOMALY AS WELL. MODELS DO NOT SHOW A LOT OF
MOISTURE IN THE COLUMN BUT STRENGTH OF SYSTEM SHOULD COMPENSATE FOR
THAT. SO EXPANDED THE SPRINKLES AND FLURRIES OVER A LARGER AREA AND
THROUGH THE EVENING HOURS.
SATURDAY/SATURDAY NIGHT...RIDGING AND DRYING ALOFT PUSH INTO THE
AREA FOR SATURDAY. SO WILL HAVE PLENTY OF SUN ALONG WITH STRONG
DOWNSLOPE WINDS. SO RAISED MAXES MORE AND I MAY NOT BE WARM ENOUGH
AS I BELIEVE MODELS ARE TOO COOL.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 246 AM MST THU JAN 31 2013
MODEL AGREEMENT IS FAIRLY GOOD IN THE EXTENDED FORECAST. ALL
SOLUTIONS ARE POINTING TO A TAME WEATHER PATTERN WITHOUT ANY BIG
WEATHER CHANGES OR PRECIPITATION CHANCES. A SYSTEM WILL MOVE ACROSS
THE NORTHERN PLAINS AND GREAT LAKES ON MONDAY...BRINGING ONLY A WIND
SHIFT AND TEMPERATURES A DEGREE OR TWO COOLER. AFTER THAT...A RIDGE
OF HIGH PRESSURE BUILDS BACK IN FROM THE WEST.
TEMPERATURES SHOULD BE WELL ABOVE NORMAL FOR THIS TIME OF YEAR
THROUGHOUT THE EXTENDED FORECAST. HIGHS SHOULD BE IN THE 50S FOR
SUNDAY THROUGH TUESDAY...WITH HIGHS CLIMBING INTO THE 60S BY THE
MIDDLE OF NEXT WEEK. GUIDANCE HAS PULLED BACK SOMEWHAT FOR HIGH
TEMPERATURES ON SUNDAY BUT STILL THINK TEMPERATURES NEARING 60 FOR
EASTERN COLORADO IS NOT OUT OF THE QUESTION.
THE ONLY OTHER CONCERN FOR THE EXTENDED FORECAST WAS LOW
TEMPERATURES. THE INITIALIZATION PROCEDURE INPUT LOW TEMPERATURES
THAT WERE LIKELY TOO WARM. CONSIDERING THE ONGOING DROUGHT
CONDITIONS AND MEX AND ECE GUIDANCE SUGGESTING TEMPERATURES MUCH
LOWER THAN THE INITIALIZATION...HAVE LOWERED LOW TEMPERATURES A
DEGREE OR TWO. GUIDANCE IS ALTERED BY CLIMATOLOGICAL DATA SO THIS
COULD BE THE REASON MEX AND ECE GUIDANCE IS BEING HELD DOWN
SOMEWHAT. HOWEVER...THE HIGHER LOW TEMPS SEEMED A LITTLE
UNREASONABLE WITH CLEAR SKIES AND LIGHT WINDS THROUGHOUT THE
EXTENDED PERIOD.
THANKS TO ALL FOR THE COLLABORATION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1040 AM MST THU JAN 31 2013
VFR TO MVFR CONDITIONS WILL PERSIST THROUGH THE TAF PERIOD AT BOTH
GLD AND MCK. FOR THE REST OF THE DAY...SOME BREEZY WINDS AND
CLEARING SKIES AT GLD...WHILE CURRENT CLOUDS WILL STICK AROUND AT
MCK. THIS EVENING A BACKDOOR COLD FRONT WILL PUSH FROM NORTHEAST TO
SOUTHWEST...ARRIVING AT MCK AROUND 22Z. THIS WILL SHIFT
WINDS...THOUGH WIND SPEEDS AT BOTH TERMINALS WILL BE LIGHT /LESS
THAN 10KTS/ THROUGHOUT THE OVERNIGHT PERIOD. SOME PATCHY FOG AND LOW
STRATUS CLOUDS ARE EXPECTED...WITH CONDITIONS MAINLY REMAINING MVFR.
BEST CHANCE FOR FOG WILL BE AT GLD...THOUGH IF FOG REACHES MCK IT
MAY STICK AROUND INTO THE MID-MORNING HOURS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...RRH
AVIATION...JJM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
448 AM MST THU JAN 31 2013
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 412 AM MST THU JAN 31 2013
FORECAST PROBLEMS WILL PROBLEMATIC TEMPERATURE FORECAST INTO TONIGHT
AND HOW MUCH TO WARM UP THE HIGH TEMPERATURES INTO SATURDAY.
SATELLITE SHOWING A BROAD UPPER TROUGH OVER THE TROUGH OVER THE
WESTERN AND CENTRAL PACIFIC WITH A RIDGE ALONG THE WEST COAST OF
NORTH AMERICA. A COUPLE OF SYSTEMS COMING INTO THE RIDGE ARE BEATING
IT DOWN. A STRONG AND COLD SYSTEM IS DIGGING INTO THE NORTH CENTRAL
PORTION OF THE COUNTRY. VERY COLD AIR MASS HAS MOVED FURTHER SOUTH
FROM YESTERDAY AND IS NOT TOO FAR NORTH AND EAST OF OUR AREA.
MODELS INITIALIZED WELL AT JET LEVEL WITH THE CANADIAN...GFS...AND
NAM DOING THE BEST. MODELS INITIALIZED WELL AT MID LEVELS WITH THE
GFS...CANADIAN...AND NAM DOING SLIGHTLY BETTER. LARGER SCALE MODELS
DO NOT HAVE THE BACKDOOR COLD FRONT FAR ENOUGH SOUTH AND WEST BY
06Z...OH SURPRISE. THE RUC HAS CONTINUED TO GET BETTER AS THE
NIGHT HAS PROGRESSED. OUTSIDE OF THE RUC ON THE LOW LEVEL THERMAL
FIELD...THE ECMWF AND GFS WERE DOING A LITTLE BETTER THAN THE UKMET
AND NAM.
TODAY/TONIGHT...VERY THICK CLOUD COVER HAS SPREAD OVER THE AREA
THROUGH THE NIGHT. WHAT THIS HAS DONE HAS PREVENTED ANY FALL OF THE
TEMPERATURES AND IN FACT HAS CAUSED THE TEMPERATURES TO RISE SOME.
NWP OUTPUT MUST BE UNDERDOING THIS CLOUD COVER AND IS TOO COOL WITH
TEMPERATURES. THIS CLOUD COVER IS BEING CAUSED BY STRONG MID TO
UPPER LEVEL JET. SOUNDINGS AND PLAN VIEW RELATIVE HUMIDITY PLOTS SHOW
THIS CLOUD COVER LASTING MOST OF THE DAY...ESPECIALLY IN THE
NORTHEAST PORTION.
BACKDOOR COLD FRONT WITH VERY COLD AIR BEHIND IT HAS BEEN MOVING
STEADILY TOWARD THE AREA THROUGH THE NIGHT AND IS NOT THAT FAR
AWAY. RUC IS CATCHING ONTO THIS AT THIS TIME. INITIALLY WAS GOING TO
CUT HIGH TEMPERATURES FROM GOING FORECAST BUT CLOUD COVER HAS
COMPLICATED THAT. SO WILL BE STARTING MUCH WARMER THAN WHAT MOST OF
THE MODELS SAY. FRONT SAGS ACROSS THE AREA THROUGH THE DAY WITH
SOME LOCATIONS IN THE NORTHEAST HALF TO TWO THIRDS REACHING THEIR
MAX BY 18Z. SO COMBINING REALITY AND THE RUC ADJUSTED MAX
TEMPERATURES UP BUT HAVE EXTREMELY LOW CONFIDENCE ABOUT THIS. DID
NOT GOES AS WARM AS IT BECAUSE OF THE CLOUD COVER. HRRR WOULD
INDICATE HIGH TEMPERATURES ABOUT 10 DEGREES WARMER IN THE SOUTHWEST
PORTION OF THE AREA THAT WHAT I HAVE.
LEFT FRONT QUADRANT OF INCOMING JET WILL CONTINUE TO AFFECT THE
NORTHEAST HALF TO TWO THIRDS OF THE AREA INTO EARLY AFTERNOON.
SEVERAL STATIONS HAVE REPORTED BRIEF PERIODS OF FLURRIES. ALL MODEL
OUTPUT AGREES IN PLACING LIGHT QPF IN THE ABOVE MENTIONED AREA. SREF
PROBABILITIES AGREE WITH THAT. IT MAKES SENSE WITH THE JET...
MESOSCALE FORCING AND LAPSE RATES IN PLACE. HOWEVER...DRIER AIR
IN THE LOWEST LAYERS. SO INTRODUCED SCATTERED FLURRIES THROUGH
MIDDAY WHEN THE FORCING AND MOISTURE LEAVE.
PROBLEMATIC MIN FORECAST AS WELL. WINDS SHIFT AROUND TO A SOUTH
DIRECTION PRETTY QUICKLY. NAM IS THE MOST AGGRESSIVE BUT IS
SUPPORTED BY OTHER MODEL OUTPUT IN BRINGING STRATUS AND FOG DURING
THE LATE EVENING AND OVERNIGHT HOURS. THIS IS AS THE COLD FRONT
RETREATS BACK AS A WARM FRONT AND ALL THE MODELS ARE VERY SIMILAR
IN DOING IT. MINS WILL PROBABLY BE REACHED IN THE EVENING
ESPECIALLY IN THE WEST AND POSSIBLY IN THE SOUTH AND A NON-DIURNAL
CURVE WILL HAVE TO BE INTRODUCED. BELIEVE MODELS ARE TOO COOL AND
WENT ABOVE THE GUIDANCE.
06Z NAM WAS MUCH MORE ROBUST IN BRINGING IN THE STRATUS AND FOG. NAM
HAS BEEN SHOWING THIS FOR A FEW DAYS PLUS THOSE SOUTH WINDS WILL BE
BLOWING ACROSS A SNOW FIELD. SO EXPANDED THE PATCHY FOG THAT WAS IN
THERE.
FRIDAY/FRIDAY NIGHT...STRATUS AND FOG GET PUSHED EAST PRETTY FAST BY
THE STRENGTHENING DOWNSLOPE WINDS. THERE MAY BE SOME HIGHER LEVEL
CLOUD COVER AROUND. INCOMING SHORTWAVE TROUGH IN NORTHWEST FLOW
ALOFT WILL PUSH A WEAK FRONT OR SURFACE TROUGH THROUGH LATER IN THE
DAY BUT IT LOOKS LIKE WINDS WILL BE FROM A DOWNSLOPE DIRECTION. SO
ENDED UP RAISING THE MAXES A LITTLE.
LEFT FRONT QUADRANT OF JET WILL AFFECT THE NORTHERN PORTION OF THE
AREA DURING THE NIGHT AS WELL AS THE ABOVE MENTIONED SHORTWAVE
TROUGH...WHICH HAPPENS TO BE THE ONE TOPPING THE RIDGE RIGHT NOW
NEAR WESTERN CANADA. ALL MODELS AGREE THAT THIS SYSTEM WILL HAVE
A VERY STRONG PV ANOMALY AS WELL. MODELS DO NOT SHOW A LOT OF
MOISTURE IN THE COLUMN BUT STRENGTH OF SYSTEM SHOULD COMPENSATE FOR
THAT. SO EXPANDED THE SPRINKLES AND FLURRIES OVER A LARGER AREA AND
THROUGH THE EVENING HOURS.
SATURDAY/SATURDAY NIGHT...RIDGING AND DRYING ALOFT PUSH INTO THE
AREA FOR SATURDAY. SO WILL HAVE PLENTY OF SUN ALONG WITH STRONG
DOWNSLOPE WINDS. SO RAISED MAXES MORE AND I MAY NOT BE WARM ENOUGH
AS I BELIEVE MODELS ARE TOO COOL.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 246 AM MST THU JAN 31 2013
MODEL AGREEMENT IS FAIRLY GOOD IN THE EXTENDED FORECAST. ALL
SOLUTIONS ARE POINTING TO A TAME WEATHER PATTERN WITHOUT ANY BIG
WEATHER CHANGES OR PRECIPITATION CHANCES. A SYSTEM WILL MOVE ACROSS
THE NORTHERN PLAINS AND GREAT LAKES ON MONDAY...BRINGING ONLY A WIND
SHIFT AND TEMPERATURES A DEGREE OR TWO COOLER. AFTER THAT...A RIDGE
OF HIGH PRESSURE BUILDS BACK IN FROM THE WEST.
TEMPERATURES SHOULD BE WELL ABOVE NORMAL FOR THIS TIME OF YEAR
THROUGHOUT THE EXTENDED FORECAST. HIGHS SHOULD BE IN THE 50S FOR
SUNDAY THROUGH TUESDAY...WITH HIGHS CLIMBING INTO THE 60S BY THE
MIDDLE OF NEXT WEEK. GUIDANCE HAS PULLED BACK SOMEWHAT FOR HIGH
TEMPERATURES ON SUNDAY BUT STILL THINK TEMPERATURES NEARING 60 FOR
EASTERN COLORADO IS NOT OUT OF THE QUESTION.
THE ONLY OTHER CONCERN FOR THE EXTENDED FORECAST WAS LOW
TEMPERATURES. THE INITIALIZATION PROCEDURE INPUT LOW TEMPERATURES
THAT WERE LIKELY TOO WARM. CONSIDERING THE ONGOING DROUGHT
CONDITIONS AND MEX AND ECE GUIDANCE SUGGESTING TEMPERATURES MUCH
LOWER THAN THE INITIALIZATION...HAVE LOWERED LOW TEMPERATURES A
DEGREE OR TWO. GUIDANCE IS ALTERED BY CLIMATOLOGICAL DATA SO THIS
COULD BE THE REASON MEX AND ECE GUIDANCE IS BEING HELD DOWN
SOMEWHAT. HOWEVER...THE HIGHER LOW TEMPS SEEMED A LITTLE
UNREASONABLE WITH CLEAR SKIES AND LIGHT WINDS THROUGHOUT THE
EXTENDED PERIOD.
THANKS TO ALL FOR THE COLLABORATION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 444 AM MST THU JAN 31 2013
AT THE BEGINNING OF THE PERIOD...EVEN THOUGH VFR CONDITIONS WILL
EXIST...THE LOW AND MID LEVEL CLOUD DECK WILL BE QUITE THICK. SOME
FLURRIES WITH LITTLE TO NO VISIBILITY RESTRICTIONS WILL
OCCUR...MAINLY AT KGLD. BY LATE MORNING SOME CLEARING WILL OCCUR
NEAR KGLD. THE WIND WILL BECOME BRIEFY GUSTY BEFORE DECREASING AND
SHIFTING TO AN EASTERLY DIRECTION AS A BACKDOOR COLD FRONT PUSHES
ACROSS THE AREA. DURING THE NIGHT THE LOW LEVELS WILL BECOME MORE
MOIST AS SOUTH TO SOUTHEAST WINDS ADVECT THE MOISTURE IN. MVFR TO
NEAR IFR CONDITIONS WILL OCCUR WHEN THIS BEGINS. THESE CONDITIONS
WILL LAST LONGER AT KMCK THAN AT KGLD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...RRH
AVIATION...BULLER
AREA FORECAST DISCUSSION...UPDATED
NWS DODGE CITY KS
533 AM CST THU JAN 31 2013
...UPDATED FOR AVIATION...
.SYNOPSIS...
ISSUED AT 349 AM CST THU JAN 31 2013
THE 00Z UPPER AIR ANALYSES SHOWED ONE MAJOR SHORTWAVE TROUGH
MOVING EASTWARD ACROSS ILLINOIS AND MISSOURI WHILE ANOTHER
SHORTWAVE TROUGH WAS JUST UPSTREAM OVER NORTH DAKOTA PROGRESSING
SOUTHEASTWARD. A LEAD ARCTIC FRONT WITH THE 1ST SHORTWAVE TROUGH
HAD STALLED ACROSS WESTERN KANSAS AND SOUTHWESTERLY DOWNSLOPE
WINDS WERE ACTUALLY PUSHING THE FRONT BACK TO THE NORTHEAST AS A
WARM FRONT. IN FACT, TEMPERATURES AS OF 3 AM WERE IN THE LOWER 30S
AT PLACES LIKE MCCOOK AND OGALLALA, NE AND GOODLAND, WHICH IS
VERY BALMY FOR THIS TIME OF MORNING IN JANUARY. MID LEVEL CLOUD
WAS PROGRESSING SOUTHWARD INTO NORTHWESTERN KANSAS. THE NEXT
ARCTIC FRONT WAS SLOWLY EDGING SOUTHWARD INTO SOUTHERN SOUTH
DAKOTA AND TEMPERATURES WERE WELL BELOW ZERO BEHIND THIS FRONT.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 349 AM CST THU JAN 31 2013
AS THE 2ND SHORTWAVE TROUGH MOVES SOUTHEAST TODAY, THE ASSOCIATED
REINFORCING ARCTIC FRONT WILL PROGRESS SOUTHWARD INTO CENTRAL AND
NORTHERN KANSAS LATE THIS MORNING, AND THEN SOUTHWESTWARD IN BACK
DOOR FASHION INTO DODGE CITY AND PRATT BY THIS EVENING. THERE ARE
SEVERAL COMPLICATING FACTORS FOR HIGH TEMPERATURES TODAY, INCLUDING
PERSISTENCE OF SNOW COVER FROM GARDEN CITY TO DODGE CITY TO HAYS,
DOWNSLOPE WARMING AHEAD OF THE FRONT, FRONTAL TIMING, AND THE
AMOUNT OF MID LEVEL CLOUD COVER. TEMPERATURES WILL BE TRICKIEST
AROUND HAYS AND STAFFORD WHERE IT IS NOT CLEAR IF THE ARCTIC AIR
WILL ARRIVE BEFORE DAYTIME HEATING OCCURS. UPON COORDINATION, IT
WAS DECIDED TO GO WITH MID 30S AT HAYS FOR AN EARLY HIGH AROUND
18-19Z, WITH FALLING TEMPERATURES THEREAFTER. WARMER 40S TO NEAR
50 DEGREES SEEMS REASONABLE FURTHER SOUTHWEST, WITH THE WARMEST
READINGS IN PLACES WITH NO SNOW COVER INCLUDING SYRACUSE, LIBERAL
AND MEDICINE LODGE. ALTHOUGH DODGE CITY, GARDEN CITY, JETMORE AND
NESS CITY WILL BE IN THE WARM SECTOR ALL DAY, SNOW COVER WILL BE
SLOW TO MELT, RESULTING IN HIGHS ONLY IN THE LOWER 40S BEFORE THE
FRONT ARRIVES. HOWEVER, IF SNOW COVER IS MORE RAPID THAN EXPECTED,
THEN HIGHS COULD REACH INTO THE MID 40S.
BY TONIGHT, SURFACE LEE TROUGHING WILL DEVELOP AHEAD OF THE NEXT
SHORTWAVE TROUGH APPROACHING THE NORTHERN ROCKIES AS THE MID
LEVEL FLOW GAINS A SLIGHT DOWNSLOPE COMPONENT ACROSS THE CENTRAL
ROCKIES. THIS WILL RESULT IN A RETURN TO SOUTH WINDS BY MIDNIGHT
SO THAT TEMPERATURES MAY ACTUALLY REACH LOWS AROUND MIDNIGHT AND
THEN HOLD STEADY OR SLOWLY RISE THEREAFTER.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 252 AM CST THU JAN 31 2013
LONG RANGE MODELS SHOW A TRANQUIL WEATHER PATTERN WITH DRY NORTHWEST
UPPER LEVEL FLOW, A FEW MINOR UPPER LEVEL SHORTWAVE TROUGHS, AND
WEAK CANADIAN COLD FRONTS. THE FIRST WAVE MOVES ACROSS THE CENTRAL
PLAINS ON FRIDAY NIGHT WITH WINDS SHIFTING FROM SOUTH TO NORTH
OVERNIGHT AND A WEAK COLD FRONT. THE NEXT UPPER LEVEL WAVE COMES
ACROSS THE PLAINS FROM THE PACIFIC NORTHWEST ON SUNDAY NIGHT BUT
THIS SYSTEM IS FAIRLY DRY. A STRONGER UPPER LEVEL SHORTWAVE TROUGH
MOVES ACROSS THE NORTHERN PLAINS ON TUESDAY MORNING WITH THE MAIN
UPPER JET STAYING WELL NORTH OF THE CENTRAL PLAINS. THE COLD AIR
ASSOCIATED WITH THIS WAVE STAYS INTO THE UPPER MIDWEST. AFTER THE
WAVE MOVES EAST INTO TUESDAY AND WEDNESDAY A WARMER AIRMASS MOVES
INTO THE WESTERN HIGH PLAINS.
OVERNIGHT LOWS ARE EXPECTED TO WARM FROM THE MID 20S FRIDAY NIGHT
AND SATURDAY NIGHT TO THE 30S INTO WEDNESDAY NIGHT. DAYTIME HIGHS
WARM FROM AROUND 50 ON FRIDAY TO THE MID AND UPPER 50S INTO
WEDNESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 523 AM CST THU JAN 31 2013
A BACKDOOR ARCTIC COLD FRONT IS FORECAST TO MOVE SOUTHWESTWARD AND
INTO WESTERN KANSAS THIS AFTERNOON WITH SOME LOW STRATUS
DEVELOPING. AHEAD OF THE FRONT EXPECT MID LEVEL CLOUDINESS.
SOUTHWEST TO NORTHWEST WINDS BECOME NORTHEAST TO EASTERLY WITH THE
ARCTIC BOUNDARY WITH IFR CONDITIONS DEVELOPING. THE ARCTIC FRONT
MAY COME A BIT FASTER THAN HRRR AND THE RAP MODELS FORECAST. FOR
NOW WILL HAVE THE ARCTIC FRONT MOVING THROUGH KHYS BY AROUND 19Z,
KDDC BY 23Z, AND KGCK BY 02Z. STRATUS MAY THEN ERODE IN THE KHYS
AREA AFTER 03Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 40 17 49 24 / 0 0 0 0
GCK 43 18 51 24 / 0 0 0 0
EHA 51 22 55 25 / 0 0 0 0
LBL 50 21 53 24 / 0 0 0 0
HYS 34 12 44 22 / 0 0 0 0
P28 47 15 46 26 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FINCH
SHORT TERM...FINCH
LONG TERM...KRUSE
AVIATION...KRUSE
AREA FORECAST DISCUSSION
NWS GOODLAND KS
412 AM MST THU JAN 31 2013
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 412 AM MST THU JAN 31 2013
FORECAST PROBLEMS WILL PROBLEMATIC TEMPERATURE FORECAST INTO TONIGHT
AND HOW MUCH TO WARM UP THE HIGH TEMPERATURES INTO SATURDAY.
SATELLITE SHOWING A BROAD UPPER TROUGH OVER THE TROUGH OVER THE
WESTERN AND CENTRAL PACIFIC WITH A RIDGE ALONG THE WEST COAST OF
NORTH AMERICA. A COUPLE OF SYSTEMS COMING INTO THE RIDGE ARE BEATING
IT DOWN. A STRONG AND COLD SYSTEM IS DIGGING INTO THE NORTH CENTRAL
PORTION OF THE COUNTRY. VERY COLD AIR MASS HAS MOVED FURTHER SOUTH
FROM YESTERDAY AND IS NOT TOO FAR NORTH AND EAST OF OUR AREA.
MODELS INITIALIZED WELL AT JET LEVEL WITH THE CANADIAN...GFS...AND
NAM DOING THE BEST. MODELS INITIALIZED WELL AT MID LEVELS WITH THE
GFS...CANADIAN...AND NAM DOING SLIGHTLY BETTER. LARGER SCALE MODELS
DO NOT HAVE THE BACKDOOR COLD FRONT FAR ENOUGH SOUTH AND WEST BY
06Z...OH SURPRISE. THE RUC HAS CONTINUED TO GET BETTER AS THE
NIGHT HAS PROGRESSED. OUTSIDE OF THE RUC ON THE LOW LEVEL THERMAL
FIELD...THE ECMWF AND GFS WERE DOING A LITTLE BETTER THAN THE UKMET
AND NAM.
TODAY/TONIGHT...VERY THICK CLOUD COVER HAS SPREAD OVER THE AREA
THROUGH THE NIGHT. WHAT THIS HAS DONE HAS PREVENTED ANY FALL OF THE
TEMPERATURES AND IN FACT HAS CAUSED THE TEMPERATURES TO RISE SOME.
NWP OUTPUT MUST BE UNDERDOING THIS CLOUD COVER AND IS TOO COOL WITH
TEMPERATURES. THIS CLOUD COVER IS BEING CAUSED BY STRONG MID TO
UPPER LEVEL JET. SOUNDINGS AND PLAN VIEW RELATIVE HUMIDITY PLOTS SHOW
THIS CLOUD COVER LASTING MOST OF THE DAY...ESPECIALLY IN THE
NORTHEAST PORTION.
BACKDOOR COLD FRONT WITH VERY COLD AIR BEHIND IT HAS BEEN MOVING
STEADILY TOWARD THE AREA THROUGH THE NIGHT AND IS NOT THAT FAR
AWAY. RUC IS CATCHING ONTO THIS AT THIS TIME. INITIALLY WAS GOING TO
CUT HIGH TEMPERATURES FROM GOING FORECAST BUT CLOUD COVER HAS
COMPLICATED THAT. SO WILL BE STARTING MUCH WARMER THAN WHAT MOST OF
THE MODELS SAY. FRONT SAGS ACROSS THE AREA THROUGH THE DAY WITH
SOME LOCATIONS IN THE NORTHEAST HALF TO TWO THIRDS REACHING THEIR
MAX BY 18Z. SO COMBINING REALITY AND THE RUC ADJUSTED MAX
TEMPERATURES UP BUT HAVE EXTREMELY LOW CONFIDENCE ABOUT THIS. DID
NOT GOES AS WARM AS IT BECAUSE OF THE CLOUD COVER. HRRR WOULD
INDICATE HIGH TEMPERATURES ABOUT 10 DEGREES WARMER IN THE SOUTHWEST
PORTION OF THE AREA THAT WHAT I HAVE.
LEFT FRONT QUADRANT OF INCOMING JET WILL CONTINUE TO AFFECT THE
NORTHEAST HALF TO TWO THIRDS OF THE AREA INTO EARLY AFTERNOON.
SEVERAL STATIONS HAVE REPORTED BRIEF PERIODS OF FLURRIES. ALL MODEL
OUTPUT AGREES IN PLACING LIGHT QPF IN THE ABOVE MENTIONED AREA. SREF
PROBABILITIES AGREE WITH THAT. IT MAKES SENSE WITH THE JET...
MESOSCALE FORCING AND LAPSE RATES IN PLACE. HOWEVER...DRIER AIR
IN THE LOWEST LAYERS. SO INTRODUCED SCATTERED FLURRIES THROUGH
MIDDAY WHEN THE FORCING AND MOISTURE LEAVE.
PROBLEMATIC MIN FORECAST AS WELL. WINDS SHIFT AROUND TO A SOUTH
DIRECTION PRETTY QUICKLY. NAM IS THE MOST AGGRESSIVE BUT IS
SUPPORTED BY OTHER MODEL OUTPUT IN BRINGING STRATUS AND FOG DURING
THE LATE EVENING AND OVERNIGHT HOURS. THIS IS AS THE COLD FRONT
RETREATS BACK AS A WARM FRONT AND ALL THE MODELS ARE VERY SIMILAR
IN DOING IT. MINS WILL PROBABLY BE REACHED IN THE EVENING
ESPECIALLY IN THE WEST AND POSSIBLY IN THE SOUTH AND A NON-DIURNAL
CURVE WILL HAVE TO BE INTRODUCED. BELIEVE MODELS ARE TOO COOL AND
WENT ABOVE THE GUIDANCE.
06Z NAM WAS MUCH MORE ROBUST IN BRINGING IN THE STRATUS AND FOG. NAM
HAS BEEN SHOWING THIS FOR A FEW DAYS PLUS THOSE SOUTH WINDS WILL BE
BLOWING ACROSS A SNOW FIELD. SO EXPANDED THE PATCHY FOG THAT WAS IN
THERE.
FRIDAY/FRIDAY NIGHT...STRATUS AND FOG GET PUSHED EAST PRETTY FAST BY
THE STRENGTHENING DOWNSLOPE WINDS. THERE MAY BE SOME HIGHER LEVEL
CLOUD COVER AROUND. INCOMING SHORTWAVE TROUGH IN NORTHWEST FLOW
ALOFT WILL PUSH A WEAK FRONT OR SURFACE TROUGH THROUGH LATER IN THE
DAY BUT IT LOOKS LIKE WINDS WILL BE FROM A DOWNSLOPE DIRECTION. SO
ENDED UP RAISING THE MAXES A LITTLE.
LEFT FRONT QUADRANT OF JET WILL AFFECT THE NORTHERN PORTION OF THE
AREA DURING THE NIGHT AS WELL AS THE ABOVE MENTIONED SHORTWAVE
TROUGH...WHICH HAPPENS TO BE THE ONE TOPPING THE RIDGE RIGHT NOW
NEAR WESTERN CANADA. ALL MODELS AGREE THAT THIS SYSTEM WILL HAVE
A VERY STRONG PV ANOMALY AS WELL. MODELS DO NOT SHOW A LOT OF
MOISTURE IN THE COLUMN BUT STRENGTH OF SYSTEM SHOULD COMPENSATE FOR
THAT. SO EXPANDED THE SPRINKLES AND FLURRIES OVER A LARGER AREA AND
THROUGH THE EVENING HOURS.
SATURDAY/SATURDAY NIGHT...RIDGING AND DRYING ALOFT PUSH INTO THE
AREA FOR SATURDAY. SO WILL HAVE PLENTY OF SUN ALONG WITH STRONG
DOWNSLOPE WINDS. SO RAISED MAXES MORE AND I MAY NOT BE WARM ENOUGH
AS I BELIEVE MODELS ARE TOO COOL.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 246 AM MST THU JAN 31 2013
MODEL AGREEMENT IS FAIRLY GOOD IN THE EXTENDED FORECAST. ALL
SOLUTIONS ARE POINTING TO A TAME WEATHER PATTERN WITHOUT ANY BIG
WEATHER CHANGES OR PRECIPITATION CHANCES. A SYSTEM WILL MOVE ACROSS
THE NORTHERN PLAINS AND GREAT LAKES ON MONDAY...BRINGING ONLY A WIND
SHIFT AND TEMPERATURES A DEGREE OR TWO COOLER. AFTER THAT...A RIDGE
OF HIGH PRESSURE BUILDS BACK IN FROM THE WEST.
TEMPERATURES SHOULD BE WELL ABOVE NORMAL FOR THIS TIME OF YEAR
THROUGHOUT THE EXTENDED FORECAST. HIGHS SHOULD BE IN THE 50S FOR
SUNDAY THROUGH TUESDAY...WITH HIGHS CLIMBING INTO THE 60S BY THE
MIDDLE OF NEXT WEEK. GUIDANCE HAS PULLED BACK SOMEWHAT FOR HIGH
TEMPERATURES ON SUNDAY BUT STILL THINK TEMPERATURES NEARING 60 FOR
EASTERN COLORADO IS NOT OUT OF THE QUESTION.
THE ONLY OTHER CONCERN FOR THE EXTENDED FORECAST WAS LOW
TEMPERATURES. THE INITIALIZATION PROCEDURE INPUT LOW TEMPERATURES
THAT WERE LIKELY TOO WARM. CONSIDERING THE ONGOING DROUGHT
CONDITIONS AND MEX AND ECE GUIDANCE SUGGESTING TEMPERATURES MUCH
LOWER THAN THE INITIALIZATION...HAVE LOWERED LOW TEMPERATURES A
DEGREE OR TWO. GUIDANCE IS ALTERED BY CLIMATOLOGICAL DATA SO THIS
COULD BE THE REASON MEX AND ECE GUIDANCE IS BEING HELD DOWN
SOMEWHAT. HOWEVER...THE HIGHER LOW TEMPS SEEMED A LITTLE
UNREASONABLE WITH CLEAR SKIES AND LIGHT WINDS THROUGHOUT THE
EXTENDED PERIOD.
THANKS TO ALL FOR THE COLLABORATION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1048 PM MST WED JAN 30 2013
VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD. LIGHT
WESTERLY WINDS WILL TURN NORTHWEST AND BECOME GUSTY AFTER
16Z...BECOMING LIGHT AGAIN FOLLOWING SUNSET AFTER 00Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...RRH
AVIATION...JSL
AREA FORECAST DISCUSSION
NWS PADUCAH KY
339 PM CST THU JAN 31 2013
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 315 PM CST THU JAN 31 2013
A STRONG ARCTIC FRONT IS COMBINING WITH AN UPPER LEVEL IMPULSE
SHOOTING QUICKLY EASTWARD TOWARDS THE REGION TO PRODUCE BANDS OF
LOCALLY HEAVY SNOWS ACROSS MISSOURI THIS AFTERNOON. MESO
MODELS...ESP THE RUC...AS WELL THE 12Z GFS TO A LESSER EXTENT ARE
CATCHING ONTO THIS. THE RUC BRINGS THE BANDING PRECIP...WHICH MAY
BEGIN BRIEFLY AS LIGHT RAIN...INTO SOUTHEAST MISSOURI AND SOUTHERN
ILLINOIS DURING THE MID TO LATE AFTERNOON HOURS IN THE POST
FRONTAL ENVIRONMENT.
THIS SNOW COULD QUICKLY BECOME HEAVY AT TIMES IN E TO W ORIENTED
BANDS ACROSS THE REGION. THIS AREA OF PRECIPITATION WILL RAPIDLY
MOVE EAST INTO ACROSS THE REMAINDER OF THE REGION EARLY TONIGHT.
THE SNOW WILL LIKELY TAPER OFF JUST AS QUICKLY AS IT BEGAN OVER
SOUTHEAST MISSOURI EARLY TONIGHT...THEN END OVER THE REST OF THE
REGION BY AROUND MIDNIGHT AS THE IMPULSE TRAVELS OFF TO THE EAST
ON THE NORTH SIDE OF THE COLD FRONT.
THE MAIN IMPACT WILL COME WITH BURSTS OF LOCALLY HEAVY SNOW IN
EAST TO WEST BANDING PRECIPITATION. WHERE...AND HOW NARROW OR
THICK THESE BANDS OF SNOW BECOME WILL DETERMINE HOW MUCH SNOW A
GIVEN LOCATION RECEIVES. AT THIS TIME...IT SEEMS LIKE MUCH OF THE
ADVISORY AREA WILL SEE UP TO A QUICK INCH OR SO OF SNOW.
HOWEVER...THERE WILL LIKELY BE LOCALLY HEAVIER BANDS THAT PRODUCE
A QUICK 2 TO 3 INCHES OF SNOW. MOTORISTS SHOULD BE PREPARED FOR
RAPIDLY FLUCTUATING VISIBILITIES TO UNDER A QUARTER MILE AT TIMES.
OTHER IMPACTS INCLUDE THE FACT THAT MUCH OF THE SNOW WILL OCCUR
DURING INCREASED TRAFFIC BETWEEN 4 PM AND 7 PM...ESPECIALLY IN
SOUTHEAST MISSOURI...SOUTHERN ILLINOIS AND THE WESTERN TIP OF
KENTUCKY AND SOUTHWEST INDIANA.
TRUE ARCTIC BLAST...THOUGH FAIRLY BRIEF...WILL FOLLOW QUICKLY IN
THE WAKE OF THIS SYSTEM. SHOULD SEE TEMPS STAY BELOW FREEZING ALL
DAY FRIDAY...WELL BELOW FREEZING IF WE GET A FRESH LAYER OF
SNOWFALL. SAME WITH FRI NIGHT. IF ANY SNOW IS ON THE
GROUND...TEMPS WILL LIKELY CHALLENGE SINGLE DIGITS IN THOSE
LOCATIONS.
WEAK DISTURBANCE AND WARM FRONT WILL LIKE PASS NEAR THE REGION
SAT. RIGHT NOW LOOKS LIKE A NON EVENT...UNLESS THE VERY LIGHT
PRECIP BEGINS EARLY ENOUGH SAT AM. IF SO...THEN A LITTLE LIGHT
SNOW...SLEET OF FREEZING RAIN WOULD BE POSSIBLE BEFORE SFC TEMPS
WARM ABOVE FREEZING.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 315 PM CST THU JAN 31 2013
A FAIRLY ACTIVE PATTERN SETTING UP FOR NEXT WEEK...WITH SEVERAL
WEATHER SYSTEMS TO KEEP AN EYE ON. HOWEVER...THEY ARE WEAK
SYSTEMS...EXCEPT FOR THE ONE SLATED FOR WED NIGHT/THURSDAY...WHICH
HAS THE BEST POTENTIAL RIGHT NOW OF BRINGING MORE WIDESPREAD
PRECIPITATION.
ON SUNDAY...WE SHOULD SEE SFC HIGH PRESSURE SLOWLY OOZE INTO THE
REGION...WITH NORTHWEST FLOW ALOFT. MODELS DIVERGE AFTER THIS...AS
THE 00Z ECMWF SHOVES THE SFC HIGH EAST SUNDAY NIGHT AS ANOTHER
FRONTAL SYSTEM BARRELS DOWN FROM THE NORTHWEST. A WEAK WAVE ALOFT
ACCOMPANIES THIS FEATURE BUT MOST OF THE ENERGY STAYS TO OUR
SOUTHWEST. THE 06Z ECMWF SHOWED A GLANCING SHOT FOR PRECIP ACROSS
SE MO/SW KY ON MONDAY...BUT THE 12Z RUN IS MUCH MORE AGGRESSIVE AND
PAINTS QPF OVER THE ENTIRE AREA. THE GFS IS MUCH SLOWER WITH THE
PROGRESSION OF THIS SYSTEM WITH ITS 06Z RUN...AND SHOWS THE SFC HIGH
RETREATING MONDAY MORNING WITH THE FRONTAL SYSTEM APPROACHING LATER
IN THE DAY...BUT WEAKENING SO MUCH THAT IT REALLY HAS LITTLE IMPACT
ON OUR AREA. THE 12Z GFS RUN IS MORE IN LINE WITH THE TIMING OF THE
00Z ECMWF NOW...BUT STILL SPLITS OUR AREA WHEN IT COMES TO
RAIN CHANCES...WITH THE MAIN PRECIP SKIRTING BY TO OUR
NORTH AND SOUTH. WILL START OUT WITH A SLIGHT CHANCE ACROSS SOUTHERN
MO AND SW KY.
ANOTHER LOW PRESSURE SYSTEM COMES DOWN OUT OF THE NORTHERN PLAINS
AND INTO THE MIDWEST LATE MONDAY NIGHT AND INTO TUESDAY.
AGAIN...MODELS DO NOT AGREE ON THIS SYSTEM EITHER...WITH THE ECMWF
MUCH DEEPER WITH THE UPPER TROUGH AND HENCE...IT INDICATES THAT SOME
PRECIP CHANCES MAY FLIRT WITH THE WABASH VALLEY OF SE IL AND THE EVV
TRI STATE REGION ON TUESDAY. SO EITHER WAY...IT DOES NOT LOOK LIKE
TOO BIG A DEAL SINCE MOST OF THE MOISTURE STAYS FURTHER NORTH AND
EAST OF THE AREA. MODEL SOUNDINGS INDICATE THAT THE LOWEST FEW
THOUSAND FT WILL BE WARM ENOUGH THAT EVEN IF IT DID PRECIPITATE...IT
SHOULD BE LIQUID. BUT THERE IS QUITE A DIFFERENCE IN LOW LEVEL TEMPS
BTWN THE GFS AND ECWMF DUE TO THE DEGREE OF THE AMPLITUDE OF THE
TROUGH COMING THROUGH.
TUESDAY NIGHT AND WEDNESDAY...HIGH PRESSURE WILL BUILD IN BEHIND THE
FRONT...BUT WILL QUICKLY MOVE EAST WED NIGHT. OUR NEXT SYSTEM COULD
IMPACT US AS EARLY AS LATE WED...OR HOLD OFF UNTIL THURSDAY.
HOWEVER...THE SIGNAL IS FAIRLY STRONG THAT WE WILL SEE SOME
PRECIPITATION ON THURSDAY...WITH SUPPORT OF THE GFS ENSEMBLES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1122 AM CST THU JAN 31 2013
BKN VFR DECK AT KEVV/KOWB ALONG WITH SOME MID CLOUDS AROUND. SCT
TO MID CLOUDS POSSIBLE ELSEWHERE AS WELL. ARCTIC COLD FRONT OFF
TO THE NORTHWEST WILL MOVE INTO THE AREA LATER THIS AFTERNOON.
GUSTY WSW WINDS AHEAD OF IT. HAVE A -SN CHANCE FROM 21Z- 01Z WITH
THE FRONTAL PASSAGE. CLEARING AFTER THAT...WITH GUSTY NW WINDS
POST FRONTAL...WHICH WILL SLACKEN BY 12Z.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR
ILZ081>094.
MO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MOZ076-
086-087-100-107>112-114.
IN...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR INZ081-
082-085>088.
KY...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR
KYZ001>022.
&&
$$
SHORT TERM...MEFFERT
LONG TERM....CW
AVIATION...CW
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1028 PM EST FRI FEB 1 2013
.SYNOPSIS...
A COLD NIGHT CAN BE EXPECTED WITH WIND CHILLS BELOW ZERO. A SERIES OF
WEATHER SYSTEMS WILL BRING PERIODS OF ACCUMULATING SNOW FOR THE
WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
A LATE EVENING UPDATE HAS BEEN ISSUED TO ACCOUNT FOR THE LATEST
TRENDS IN SKY COVERAGE WITH THE FORECAST AREA BISECTED BY AN AREA
OF CLEARING. TEMPS AND WINDS WERE ALSO UPDATED TO ACCOUNT FOR THE
LATEST TRENDS WITH VALUES NEAR WIND CHILL ADVISORY CRITERIA ACROSS
THE HIGHER ELEVATIONS OF THE LAUREL HIGHLANDS/ALLEGHENY FRONT IN
WV/MD/PA. THE REST OF THE PREVIOUS DISCUSSION REMAINS THE SAME.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES AN INITIAL SHORT WAVE
TROUGH PUSHING OFF THE MID-ATLANTIC COAST...WITH LINGERING VORT
ENERGY ON THE LEE SIDE OF THIS FEATURE PROVIDING ENOUGH FORCING
FOR A FEW FLURRIES IN WESTERN PA. AT 850MB...TEMPS RANGE FROM -10C
TO -16C ACROSS THE AREA TONIGHT...WITH A WEST-NORTHWESTERLY FLOW
CONTINUING OFF OF LAKE ERIE. AT THE SURFACE...A 1032MB HIGH IS
CENTERED ACROSS THE TENNESSEE VALLEY AND IS EDGING EAST-
NORTHEASTWARD TOWARD THE AREA. YET...THE PRESSURE GRADIENT BETWEEN
THE HIGH AND A SURFACE LOW WELL NORTH OF THE REGION IS ALLOWING
FOR 5-10KT SOUTHWESTERLY WINDS ACROSS THE LOWLANDS AND 10-15KTS
ACROSS THE RIDGES. THE COMBINATION OF TEMPS HAVING ALREADY DROPPED
INTO THE SINGLE DIGITS ACROSS THE HIGHER ELEVATIONS AND WINDS
CONTINUING NOCTURNALLY...HAS LED TO WIND CHILLS AT -10 TO -20 IN
THE RIDGES OF WV/MD/PA...THUS PROMPTING THE WIND CHILL ADVISORY.
OVERNIGHT...THE SHORT WAVE WILL SHIFT EAST OF THE AREA AND THE
SURFACE HIGH WILL PASS SOUTH OF THE AREA. NEGATIVE VORTICITY
ADVECTION IN THE DEPARTURE OF THE SHT WV WILL ALLOW LINGERING
FLURRIES TO DIMINISH WITH MANY LOCATIONS CLEARING FOR A PERIOD
OVERNIGHT. LOCALIZED 30KT 850MB WINDS WILL CONTRIBUTE TO
INCREASED WINDS ACROSS THE HIGHER ELEVATIONS AND ALLOW FOR WINDS
CHILLS TO REMAIN AT -10 TO -20. ELSEWHERE...TEMPS DROPPING INTO
THE SINGLE DIGITS...ESPECIALLY IN AREAS OF CLEARING...WILL ALLOW
FOR 0 TO 10 BELOW WIND CHILLS.
SATURDAY...THERE IS REASONABLE WRF-ARW/NMM/SREF AGREEMENT THAT A
WEAK LOW/CLIPPER SYSTEM WILL DIVE SOUTHEASTWARD FROM THE UPPER
MIDWEST INTO THE REGION DURING THE DAY. LIGHT SNOW WILL BE MORE
WIDESPREAD WITH LOCALIZED AREAS OF MORE MODERATE SNOW AT TIMES
LATER IN THE DAY AS THE SYSTEM CROSSES THE UPPER OHIO VALLEY. THE
ONSET OF SNOW IS PROGGED TO BE BETWEEN 12Z AND 15Z IN EASTERN
OHIO. THE SNOW WILL CONTINUE INTO THE EVENING...WITH 20:1 SNOW-TO-
LIQUID RATIOS BRINGING A LIGHT AND FLUFFY-NATURED SNOW TO THE
AREA. WITH AROUND A TENTH OF QPF ANTICIPATED WITH THE SYSTEM...1
TO 2 INCHES SEEMS REASONABLE ACROSS THE LOWLANDS DURING THE DAY
WITH 2 TO 3 INCHES FOR THE HIGHER ELEVATIONS.
FOR TEMPS...HIGHS ARE CLOSER TO THE COOLER MAV GUIDANCE...WITH
CLOUD COVERAGE LIMITING TEMPS. HIGHS WILL RANGE FROM NEAR 20
ACROSS THE LAUREL HIGHLANDS/ALLEGHENY FRONT TO THE MID 20S ACROSS
THE LOWLANDS.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
SNOW SHOWERS WILL CONTINUE THROUGH SUNDAY WITH A PERIOD OF LIGHTER
ACCUMULATION SATURDAY EVENING AS FIRST SHORTWAVE EXITS AND NEXT
SHORTWAVE DIVES SOUTHEAST. SNOW SHOWERS WILL RE-INTENSIFY LATER
SATURDAY NIGHT INTO MIDDAY SUNDAY. BEHIND 2ND SHORTWAVE SUNDAY
FLOW WILL TURN NORTHWEST WITH -14 TO -16C 850MB TEMPS CROSSING
LAKES AND DECENT INVERSION HEIGHTS. USING AN AVERAGE SNOW TO
LIQUID RATIO OF 20 TO 1 WENT WITH A 36 HOUR SNOWFALL OF 4 TO 6
INCHES OUTSIDE OF RIDGES...WITH 6 TO 10 IN THE HIGHEST ELEVATIONS.
HAVE ISSUED A LONG DURATION WINTER WEATHER ADVISORY TO DEAL WITH
SNOWFALL.
TEMPERATURES SATURDAY NIGHT WILL HOLD FAIRLY STEADY IN THE 20S,
THEN HOLD STEADY IN THE 20S EARLY THEN FALL SUNDAY AFTERNOON.
STILL SOME LEFTOVER LAKE/UPSLOPE SUNDAY NIGHT AS COLD ADVECTION
CONTINUES.
FOR MONDAY YET ANOTHER SHORTWAVE WILL BE DIVING SOUTHEAST WITH
SNOW SHOWERS DEVELOPING DURING THE DAY. THIS SYSTEM MAY NOT HAVE
AS MUCH MOISTURE TO WORK WITH SO HAVE KEPT POPS IN THE CHANCE
CATEGORY FOR NOW...TEMPERATURES STILL BELOW NORMAL.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
UNSETTLED PATTERN WILL CONTINUE AT THE BEGINNING OF THE EXTENDED
FORECAST. ALTHOUGH SNOW MAY BRIEFLY STOP MONDAY NIGHT INTO TUESDAY
MORNING...12Z GFS/ECMWF SHOW THE NEXT CLIPPER PUSHING THROUGH
TUESDAY NIGHT. SNOW MAY COME TO AN END WEDNESDAY WITH HIGH PRESSURE
OVERHEAD NOT ALLOWING FLOW OFF THE GREAT LAKES. AS THE HIGH MOVES
OFFSHORE THURSDAY...SOUTHWEST FLOW SHOULD ALLOW FOR MODERATION IN
TEMPERATURES TOWARDS NORMAL LEVELS. 12Z GFS SHOWS A DRY FRONTAL
PASSAGE ON FRIDAY...A SEEMINGLY UNLIKELY SCENARIO. WILL GO WITH POPS
FOR THE FRONTAL PASSAGE FALLING IN LINE BETTER WITH THE 12Z ECMWF.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
LOW VFR STRATOCU WILL PERSIST INTO THE EVENING AND SLOWLY DIMINISH
IN COVERAGE AS THE STRATOCU DECK SCATTERS OUT BY EARLY MORNING.
A FEW SNOW SHOWERS WILL CONTINUE INTO THE EARLY EVENING BEFORE
ENDING. GENL VFR IS FORECAST FOR TONIGHT AND EARLY SATURDAY..BUT
CONDITIONS WILL DEGRADE IFR BY SATURDAY AFTERNOON AS LOW PRESSURE
DEVELOPS WIDESPREAD SNOW OVER THE UPPER OHIO VALLEY.
.OUTLOOK.../SATURDAY NIGHT THROUGH MONDAY/...
PERIODIC RESTRICTIONS ARE EXPECTED THROUGH EARLY NXT WEEK AS A
SERIES OF UPPER DISTURBANCES MOVE OFF THE GREAT LAKES.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER WEATHER ADVISORY FROM 10 AM SATURDAY TO 7 PM EST SUNDAY
FOR MDZ001.
WIND CHILL ADVISORY UNTIL 10 AM EST SATURDAY FOR MDZ001.
OH...WINTER WEATHER ADVISORY FROM 10 AM SATURDAY TO 7 PM EST SUNDAY
FOR OHZ039>041-048>050-057>059-068-069.
PA...WINTER WEATHER ADVISORY FROM 10 AM SATURDAY TO 7 PM EST SUNDAY
FOR PAZ007>009-013>016-020>023-029-031-073>076.
WIND CHILL ADVISORY UNTIL 10 AM EST SATURDAY FOR PAZ074-076.
WV...WINTER WEATHER ADVISORY FROM 10 AM SATURDAY TO 7 PM EST SUNDAY
FOR WVZ001>004-012-021>023-041.
WIND CHILL ADVISORY UNTIL 10 AM EST SATURDAY FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
804 PM EST FRI FEB 1 2013
.SYNOPSIS...
A COLD NIGHT CAN BE EXPECTED WITH WIND CHILLS BELOW ZERO. A SERIES OF
WEATHER SYSTEMS WILL BRING PERIODS OF ACCUMULATING SNOW FOR THE
WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AN UPDATE HAS BEEN SENT OUT THIS EVENING TO ISSUE A WIND CHILL
ADVISORY FOR THE LAUREL HIGHLANDS/ALLEGHENY FRONT OF WV/MD/PA
WITH AN SPS ISSUED FOR SUB-ZERO WIND CHILLS ELSEWHERE. IN
ADDITION...SCATTERED FLURRIES HAVE BEEN ADDED FOR THIS EVENING
ACROSS THE PIT METRO AND NORTHWARD.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES AN INITIAL SHORT WAVE
TROUGH PUSHING OFF THE MID-ATLANTIC COAST...WITH LINGERING VORT
ENERGY ON THE LEESIDE OF THIS FEATURE PROVIDING ENOUGH FORCING FOR
A FEW FLURRIES AND LIGHT SNOW SHOWERS IN WESTERN PA. AT
850MB...TEMPS RANGE FROM -10C TO -16C ACROSS THE AREA
TONIGHT...WITH A WEST-NORTHWESTERLY FLOW CONTINUING OFF OF LAKE
ERIE. AT THE SURFACE...A 1032MB HIGH IS CENTERED ACROSS THE
TENNESSEE VALLEY AND IS EDGING EAST-NORTHEASTWARD TOWARD THE
AREA. YET...THE PRESSURE GRADIENT BETWEEN THE HIGH AND A SURFACE
LOW WELL NORTH OF THE REGION IS ALLOWING FOR 5-10KT SOUTHWESTERLY
WINDS ACROSS THE LOWLANDS AND 10-15KTS ACROSS THE RIDGES. THE
COMBINATION OF TEMPS HAVING ALREADY DROPPED INTO THE SINGLE DIGITS
ACROSS THE HIGHER ELEVATIONS AND WINDS CONTINUING
NOCTURNALLY...HAS LED TO WIND CHILLS AT -10 TO -20 IN THE RIDGES
OF WV/MD/PA...THUS PROMPTING THE WIND CHILL ADVISORY.
OVERNIGHT...THE SHORT WAVE WILL SHIFT EAST OF THE AREA AND THE
SURFACE HIGH WILL PASS SOUTH OF THE AREA. NEGATIVE VORTICITY
ADVECTION IN THE DEPARTURE OF THE SHT WV WILL ALLOW LINGERING
FLURRIES/SNOW SHOWERS TO DIMINISH AND SOME BREAKS IN CLOUD
COVERAGE. LOCALIZED 30KT 850MB WINDS WILL CONTRIBUTE TO INCREASED
WINDS ACROSS THE HIGHER ELEVATIONS AND ALLOW FOR WINDS CHILLS TO
REMAIN AT -10 TO -20. ELSEWHERE...TEMPS DROPPING INTO THE SINGLE
DIGITS...ESPECIALLY IN AREAS OF CLEARING...WILL ALLOW FOR 0 TO 10
BELOW WIND CHILLS.
SATURDAY...THERE IS REASONABLE WRF-ARW/NMM/SREF AGREEMENT THAT A
WEAK LOW/CLIPPER SYSTEM WILL DIVE SOUTHEASTWARD FROM THE UPPER
MIDWEST INTO THE REGION DURING THE DAY. LIGHT SNOW WILL BE MORE
WIDESPREAD WITH LOCALIZED AREAS OF MORE MODERATE SNOW AT TIMES
LATER IN THE DAY AS THE SYSTEM CROSS THE UPPER OHIO VALLEY. THE
ONSET OF SNOW IS PROGGED TO BE BETWEEN 12Z AND 15Z IN EASTERN
OHIO. THE SNOW WILL CONTINUE INTO THE EVENING...WITH 20:1 SNOW-TO-
LIQUID RATIOS BRINGING A LIGHT AND FLUFFY-NATURED SNOW TO THE
AREA. WITH AROUND A TENTH OF QPF ANTICIPATED WITH THE SYSTEM...1
TO 2 INCHES SEEMS REASONABLE ACROSS THE LOWLANDS DURING THE DAY
WITH 2 TO 3 INCHES FOR THE HIGHER ELEVATIONS.
FOR TEMPS...HIGHS ARE CLOSER TO THE COOLER MAV GUIDANCE...WITH
CLOUD COVERAGE LIMITING TEMPS. HIGHS WILL RANGE FROM NEAR 20
ACROSS THE LAUREL HIGHLANDS/ALLEGHENY FRONT TO THE UPPER 20S IN
LOCATIONS IN EASTERN OHIO.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
SNOW SHOWERS WILL CONTINUE THROUGH SUNDAY WITH A PERIOD OF LIGHTER
ACCUMULATION SATURDAY EVENING AS FIRST SHORTWAVE EXITS AND NEXT
SHORTWAVE DIVES SOUTHEAST. SNOW SHOWERS WILL RE-INTENSIFY LATER
SATURDAY NIGHT INTO MIDDAY SUNDAY. BEHIND 2ND SHORTWAVE SUNDAY
FLOW WILL TURN NORTHWEST WITH -14 TO -16C 850MB TEMPS CROSSING
LAKES AND DECENT INVERSION HEIGHTS. USING AN AVERAGE SNOW TO
LIQUID RATIO OF 20 TO 1 WENT WITH A 36 HOUR SNOWFALL OF 4 TO 6
INCHES OUTSIDE OF RIDGES...WITH 6 TO 10 IN THE HIGHEST ELEVATIONS.
HAVE ISSUED A LONG DURATION WINTER WEATHER ADVISORY TO DEAL WITH
SNOWFALL.
TEMPERATURES SATURDAY NIGHT WILL HOLD FAIRLY STEADY IN THE 20S,
THEN HOLD STEADY IN THE 20S EARLY THEN FALL SUNDAY AFTERNOON.
STILL SOME LEFTOVER LAKE/UPSLOPE SUNDAY NIGHT AS COLD ADVECTION
CONTINUES.
FOR MONDAY YET ANOTHER SHORTWAVE WILL BE DIVING SOUTHEAST WITH
SNOW SHOWERS DEVELOPING DURING THE DAY. THIS SYSTEM MAY NOT HAVE
AS MUCH MOISTURE TO WORK WITH SO HAVE KEPT POPS IN THE CHANCE
CATEGORY FOR NOW...TEMPERATURES STILL BELOW NORMAL.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
UNSETTLED PATTERN WILL CONTINUE AT THE BEGINNING OF THE EXTENDED
FORECAST. ALTHOUGH SNOW MAY BRIEFLY STOP MONDAY NIGHT INTO TUESDAY
MORNING...12Z GFS/ECMWF SHOW THE NEXT CLIPPER PUSHING THROUGH
TUESDAY NIGHT. SNOW MAY COME TO AN END WEDNESDAY WITH HIGH PRESSURE
OVERHEAD NOT ALLOWING FLOW OFF THE GREAT LAKES. AS THE HIGH MOVES
OFFSHORE THURSDAY...SOUTHWEST FLOW SHOULD ALLOW FOR MODERATION IN
TEMPERATURES TOWARDS NORMAL LEVELS. 12Z GFS SHOWS A DRY FRONTAL
PASSAGE ON FRIDAY...A SEEMINGLY UNLIKELY SCENARIO. WILL GO WITH POPS
FOR THE FRONTAL PASSAGE FALLING IN LINE BETTER WITH THE 12Z ECMWF.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
LOW VFR STRATOCU WILL PERSIST INTO THE EVENING AND SLOWLY DIMINISH
IN COVERAGE AS THE STRATOCU DECK SCATTERS OUT BY EARLY MORNING.
A FEW SNOW SHOWERS WILL CONTINUE INTO THE EARLY EVENING BEFORE
ENDING. GENL VFR IS FORECAST FOR TONIGHT AND EARLY SATURDAY..BUT
CONDITIONS WILL DEGRADE IFR BY SATURDAY AFTERNOON AS LOW PRESSURE
DEVELOPS WIDESPREAD SNOW OVER THE UPPER OHIO VALLEY.
.OUTLOOK.../SATURDAY NIGHT THROUGH MONDAY/...
PERIODIC RESTRICTIONS ARE EXPECTED THROUGH EARLY NXT WEEK AS A
SERIES OF UPPER DISTURBANCES MOVE OFF THE GREAT LAKES.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER WEATHER ADVISORY FROM 10 AM SATURDAY TO 7 PM EST SUNDAY
FOR MDZ001.
WIND CHILL ADVISORY UNTIL 10 AM EST SATURDAY FOR MDZ001.
OH...WINTER WEATHER ADVISORY FROM 10 AM SATURDAY TO 7 PM EST SUNDAY
FOR OHZ039>041-048>050-057>059-068-069.
PA...WINTER WEATHER ADVISORY FROM 10 AM SATURDAY TO 7 PM EST SUNDAY
FOR PAZ007>009-013>016-020>023-029-031-073>076.
WIND CHILL ADVISORY UNTIL 10 AM EST SATURDAY FOR PAZ074-076.
WV...WINTER WEATHER ADVISORY FROM 10 AM SATURDAY TO 7 PM EST SUNDAY
FOR WVZ001>004-012-021>023-041.
WIND CHILL ADVISORY UNTIL 10 AM EST SATURDAY FOR WVZ023-041.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
AVIATION...RSD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1156 PM EST WED JAN 30 2013
.UPDATE...
ISSUED AT 1012 PM EST WED JAN 30 2013
ALL HEADLINES THAT END THIS EVENING HAVE BEEN ALLOWED TO EXPIRE AS
SCHEDULED. ATTENTION NOW TURNS TO LAKE ENHANCED/LAKE EFFECT SNOW AS
COLDER AIR CONTINUES TO FLOW INTO THE AREA BEHIND DEPARTING STORM
SYSTEM. KMQT RADAR HAS SHOWN A NICE EXPANSION OF HVY SNOW BANDS OFF
LAKE SUPERIOR THIS EVENING UNDER LINGERING DEEP MOISTURE/CAA...AND
VAD WIND PROFILE SHOWS NEARLY UNIDIRECTIONAL NORTHERLY WINDS TO
11KFT MSL. THERE ARE CONFLICTING SIGNALS ON HOW MUCH THE WIND MAY
BACK OVERNIGHT AS LOCAL HIGH RES-WRF MAINTAINS A MORE NRLY WIND INTO
NCNTRL UPPER MI WHILE NAM BACKS WIND MORE NW. GIVEN TRENDS IN HRLY
RUC RAPID REFRESH RUNS TO SLOW THE BACKING...OPTED TO EXTEND WARNING
FOR MARQUETTE COUNTY UNTIL 11Z. WITH RATHER PERSISTENT HVY SNOW
OCCURRING AT THE OFFICE THIS EVENING AND RADAR IMAGERY SHOWING
EXPANSION OF HVY SNOW BANDS...WOULD NOT BE SURPRISED TO SEE SOME
LOCALIZED ACCUMULATIONS OVER 1 FOOT DURING THE NIGHT IN THE HIGHER
TERRAIN BETWEEN BIG BAY...NEGAUNEE...GWINN AND SKANDIA. THIS HVY
SNOW WILL ALSO TARGET WRN ALGER COUNTY WEST OF SHINGLETON. WHILE
WARNING FOR ALGER/LUCE/NRN SCHOOLCRAFT ONLY GOES TO 12Z...WILL LET
MID SHIFT TAKE A LOOK AT REPLACEMENT WITH A LONGER DURATION LAKE
EFFECT SNOW ADVY OR WARNING FOR THAT AREA.
TO THE W...NO CHANGES WERE MADE TO THE GOGEBIC/ONTONAGON ADVY. OVER
THE KEWEENAW...COLD AIR WILL PUSH THE DGZ DOWN TO NEAR THE SFC...
RESULTING IN SMALL SNOWFLAKES THAT ARE VERY EFFECTIVE AT REDUCING
VIS. WHILE ACCUMULATIONS WILL PROBABLY ONLY BE IN THE 2-4 INCH
RANGE/12HRS AT MOST LOCATIONS...VERY LOW VIS DURING -SHSN ALONG WITH
OCNL BLSN SUGGEST AN ADVY HEADLINE IS WARRANTED FOR KEWEENAW/NRN
HOUGHTON AS DRIVING WILL BE DIFFICULT AT TIMES.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 441 PM EST WED JAN 30 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
HUDSON BAY AND NW ONTARIO THROUGH MN/IA INTO ERN OK. THE POTENT
SHORTWAVE TROUGH OVER SW WI AND ASSOCIATED DEFORMATION ZONE
CONTINUED TO SUPPORT A HEAVY SNOW BAND FROM ERN WI INTO THE E HALF
OF UPPER MI. LIGHTER SNOW WAS OBSERVED OVER THE WEST HALF OF UPPER
MI. SNOW TOTALS OF AROUND 6 INCHES WERE OBSERVED BY 21Z FROM THE NWS
MQT OFFICE TO MNM...GLADSTONE AND MANISTIQUE. A TIGHT GRADIENT BTWN
THE 987 MB LOW OVER SRN LOWER MI AND ARCTIC HIGH PRES BUILDING INTO
THE PLAINS HAS RESULTED IN GALES ACROSS LAKE SUPERIOR AND GUSTY N
WINDS TO 30 MPH OVER MOST OF THE CWA.
TONIGHT AND THURSDAY...THE HEAVY SNOW BAND WHICH CORRELATED WELL WITH
NAM/RUC 700-600 MB FGEN IS EXPECTED TO SHIF QUICKLY TO THE NORTHEAST
THIS EVENING LEAVING MAINLY LIGHT SNOW THAT WILL DIMINISH BTWN
00Z-03Z. HOWEVER...COLDER AIR MOVING IN ON THE STRONG N WINDS
COMBINED WITH 850 MB TEMPS TO AROUND -15C WILL CONTINUE TO SUPPORT
LCLY HIGHER SNOWFALL RATES N CNTRL...ESPECIALLY VCTY MARQUETTE THIS
EVENING WITH CYCLONIC LOW LEVEL 340-350 WIND DIRECTION NEAR THE
SHORE. FAVORABLE UPSLOPE NRLY FLOW INTO THE FAR WEST SHOULD ALSO
BRING INCREASING LES INTO IWD. RADAR TRENDS AND MODELS SUGGEST
ADDITIONAL SYNOPTIC SNOW POTENTIAL IN THE 1 TO 3 INCH RANGE BTWN 21Z-
03Z. HOWEVER AREAS WITH LAKE CONTRIBUTION COULD SEE ANOTHER 3 TO 6
INCHES THROUGH 12Z/THU.
AS THE STRONGER SYNOPTIC FORCING WITH THE SHRTWV MOVES OUT THIS
EVENING...HEADLINES ARE SET TO EXPIRE BY AROUND 03Z OVER THE S CWA.
A TRANSISTION TO LAKE EFFECT SNOW WILL CONTINUE OVERNIGHT WITH
FAVORABLE CONDITION PERSISTING INTO THURSDAY. ANOTHER TRAILING
SHRTWV SLIDING SE INTO THE UPPER LAKES WILL MAINTAIN 850-700 MB
MOISTURE AND INVERSION HEIGHTS AOA 10K FT. WITH THE WINDS BACKING
SLIGHTLY TO 340-330 THE HEAVIER LES WILL CONTINUE TO FOCUS INTO THE
FAR WEST AND TO AREAS EAST OF MARQUETTE. 850 MB TEMPS FALLING TO
AROUND -20C MAY SHRINK THE DGZ LAYER INTO THE 1K-3K RANGE BUT STILL
SHOULD BE SUFFICIENT FOR LSR VALUES CLOSE TO 25/1. ADDITIONAL
SNOWFALL AMOUNTS OF 3 TO 7 INCHES ARE POSSIBLE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 441 PM EST WED JAN 30 2013
MODELS ARE IN GOOD GENERAL AGREEMENT THROUGH THE EXTENDED WITH DEEP
UPPER TROUGH STARTING THE PERIOD FRI AND GRADUALLY BREAKING DOWN AND
SHIFTING WEST THROUGH NEXT WED...AS AN UPPER RIDGE MOVES INTO THE
WRN CONUS.
GOOD NW WIND LES WILL BE ONGOING INTO THU NIGHT GIVEN NW LOW LEVEL
FLOW...AMPLE MOISTURE AND 825MB INVERSION TOP TEMPS AROUND -25C.
LATE THU NIGHT AND FRI...A SFC HIGH WILL MOVE S OF THE CWA WHILE A
SHORTWAVE TROUGH DIVES IN FROM THE NW FORMING A MESO-LOW OVER ERN
LAKE SUPERIOR LATE FRI. THIS TURNS THE NW WINDS WLY BY FRI
AFTERNOON...FOCUSING LES OVER THE KEWEENAW AND FAR NE UPPER MI.
PRIOR WIND SHIFT...THE BEST LES WILL BE FOCUSED OVER ONTONAGON AND
GOGEBIC COUNTIES AND OVER ERN UPPER MI FROM MUNISING TO GRAND
MARAIS. LES SHOULD INITIALLY WEAKEN SOME LATE THU NIGHT AS RIDGING
MOVES INTO THE AREA...BUT WILL GET A BOOST FROM THE SHORTWAVE LATER
ON FRIDAY. THERE IS ALREADY A LES ADVISORY FOR ONTONAGON/GOGEBIC
COUNTIES THROUGH THU NIGHT...AND THAT STILL LOOKS FINE. BUT WILL
LIKELY ALSO NEED HEADLINES FOR THE ERN U.P. THU NIGHT INTO FRI. THE
KEWEENAW MAY ALSO NEED HEADLINES FRI INTO FRI NIGHT. WILL NOT ISSUE
ANY NEW HEADLINES AT THIS POINT GIVEN HEADLINES ALREADY IN EFFECT
OVER THE ERN U.P. AND SOME UNCERTAINTY AS TO THE RESIDENCE TIME AND
INTENSITY OF ANY STRONGER BANDS THAT MOVE ACROSS THE KEWEENAW.
THU NIGHT THROUGH FRI NIGHT LOOKS TO BE THE COLDEST PERIOD OF THE
NEXT WEEK. LOWS THU NIGHT AND FRI NIGHT LOOKS TO FALL TO THE TEENS
BELOW ZERO WITH WIND CHILLS TO -35F OVER PARTS OF THE INTERIOR.
HIGHS ON FRI LOOK TO BE AROUND ZERO OVER THE INTERIOR W...AND IN THE
LOW TEENS ABOVE ZERO E. WIND CHILL VALUES ARE CURRENTLY FORECAST TO
BE IN TEENS BELOW ZERO AT THE WARMEST FRI AFTERNOON OVER THE
INTERIOR W...AND IN THE SINGLE DIGITS BELOW ZERO E. WILL LIKELY NEED
SOME WIND CHILL ADVISORY HEADLINES UP WHERE THERE ARE NO OTHER
WINTER WX HEADLINES.
MODELS IN RELATIVELY GOOD AGREEMENT WITH A CLIPPER SHORTWAVE MOVING
THROUGH LATE SAT INTO EARLY SAT NIGHT...BUT ONLY MINOR SYNOPTIC SNOW
ACCUMULATIONS AND INCREASED NW WIND LES ARE EXPECTED TO RESULT FROM
THE SYSTEM.
SFC RIDGING MOVES OVER ON SUN AHEAD OF THE NEXT...STRONGER...CLIPPER
SYSTEM THAT MODEL DEPICT MOVING THROUGH. ALTHOUGH MODELS SEEM TO
AGREE FAIRLY WELL ON THE OVERALL TRACK AND INTENSITY OF THE
SYSTEM...THE 00Z/30 ECMWF IS 6-12 HOURS FASTER THAN THE 12Z/30 GFS.
SEVERAL INCHES OF SNOW MAY RESULT AREA WIDE FROM THIS SYSTEM.
MODELS THEN INDICATE...WITH GREATER UNCERTAINTY...ANOTHER CLIPPER
SYSTEM MOVING THROUGH SOMETIME MIDWEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1155 PM EST WED JAN 30 2013
AT KIWD...LAKE EFFECT -SHSN WILL INCREASE OVERNIGHT AS COLDER AIR
FLOWS INTO THE AREA AND LOW-LEVEL WINDS BECOME MORE CONVERGENT INTO
WRN UPPER MI. AS A RESULT...IFR CONDITIONS SHOULD GENERALLY PREVAIL
AT KIWD THRU TODAY. SOME IMPROVEMENT IS POSSIBLE THIS EVENING AS WINDS
BEGIN TO BACK...POSSIBLY SHIFTING -SHSN N OF KIWD. AT KCMX...IFR
CONDITIONS SHOULD PREVAIL OVERNIGHT AS LAKE EFFECT -SHSN CONTINUE
UNDER INCREASINGLY COLDER AIR MASS. WITH THE COLDER AIR...SNOWFLAKE
SIZE WILL BECOME SMALLER AND VERY EFFECTIVE AT KEEPING VIS LOW.
COMBINATION OF SNOW AND SOME BLSN WILL LIKELY RESULT IN LIFR
CONDITIONS FOR MUCH OF THE DAY INTO THE EVENING AT KCMX. AT KSAW...
LAKE EFFECT SHSN UNDER NORTHERLY WINDS SHOULD LEAD TO IFR/LIFR
CONDITIONS FOR THE NEXT SEVERAL HRS. AS WINDS BACK AND PUSH HEAVIER
LAKE EFFECT SHSN TO THE E...EXPECT IMPROVEMENT TO MVFR EARLY IN THE
MORNING. MVFR SHOULD THEN PREVAIL FOR THE REMAINDER OF THE FCST
PERIOD. AS IS TYPICAL FOR LAKE EFFECT SNOW...EXPECT VIS AT ALL SITES
TO BE HIGHLY VARIABLE AT TIMES AS SNOW BANDS MOVE ACROSS THE AREA.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 441 PM EST WED JAN 30 2013
N TO NW GALES OF 35 TO 40 KNOTS WILL CONTINUE THROUGH MUCH OF
TONIGHT...WITH A FEW GALE FORCE GUSTS TO 35 KNOTS LINGERING E
THROUGH THURSDAY. LOW PRESSURE OVER LOWER MICHIGAN WILL LIFT
NORTHEAST INTO ONTARIO AND QUEBEC TONIGHT. WITH PLENTY OF
COLD AIR SINKING IN BEHIND THE LOW AND STRONG WINDS...HEAVY FREEZING
SPRAY WILL PREVAIL THROUGH THURSDAY NIGHT...AND MAY LINGER OVER THE
FAR EAST THROUGH FRIDAY NIGHT. A TROUGH WILL LINGER OVER LAKE
SUPERIOR THROUGH THURSDAY...AS STRONG HIGH PRESSURE SINKS ACROSS THE
PLAINS STATES. EXPECT THE HIGH PRESSURE SYSTEM TO WEAKEN SLIGHTLY
OVER THE MISSISSIPPI VALLEY FRIDAY...WHILE PUSHING A RIDGE ACROSS
WESTERN LAKE SUPERIOR. WEAK LOW PRESSURE WILL LINGER ACROSS EASTERN
LAKE SUPERIOR THROUGH SATURDAY. ANOTHER LOW PRESSURE TROUGH WILL
SINK SOUTHWARD FROM MANITOBA INTO THE UPPER GREAT LAKES SATURDAY
EVENING...BEFORE MOVING INTO THE LOWER GREAT LAKES DURING THE DAY
SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST /6 AM CST/ FRIDAY FOR
MIZ001>003-009.
WINTER STORM WARNING UNTIL 6 AM EST THURSDAY FOR MIZ005.
WINTER STORM WARNING UNTIL 7 AM EST THURSDAY FOR MIZ006-007-085.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST SATURDAY FOR
LSZ265>267.
GALE WARNING UNTIL 4 AM EST THURSDAY FOR LSZ264>267.
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST /MIDNIGHT CST/
SATURDAY FOR LSZ162-263-264.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...ROLFSON
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1152 PM EST WED JAN 30 2013
.AVIATION...
//DISCUSSION...
GUSTY WESTERLY WINDS WILL PERSIST THROUGH THE MORNING AS ARCTIC AIR
CONTINUES TO POUR INTO THE FORECAST AREA. STEEPENING LOW LEVEL LAPSE
RATES COURTESY OF THE COLD AIR ADVECTION WILL BRING SOME STRONG WIND
GUSTS DOWN TO THE SURFACE...LIKELY TOPPING 30 KNOTS AT TIMES THIS
MORNING. THE WINDS WILL DIMINISH SLIGHTLY THIS AFTERNOON AS THE
GRADIENT RELAXES. WIDESPREAD MVFR CIGS WILL SLOWLY LIFT DURING THE
COURSE OF THE TAF PERIOD AS THE COLD AIR ADVECTION LIFTS INVERSION
HEIGHTS. WHILE SNOW SHOWERS WILL REMAIN RATHER LIGHT
OVERNIGHT...SOME INCREASE IN INTENSITY IS EXPECTED AFTER
12Z...PRIMARILY FROM PTK SOUTH. WITH STILL SOME UNCERTAINTY AS TO
HOW THE LAKE BANDS WILL SET UP...WILL CONTINUE WITH MVFR TYPE
CIGS/VSBY IN THE SNOW SHOWERS THROUGH THE MORNING AT THIS TIME.
FOR DTW...EXPECT WESTERLY WIND GUSTS AROUND OR ABOVE 30 KNOTS
THROUGH THE MORNING AND INTO THE AFTERNOON. THERE IS A POTENTIAL FOR
ENHANCED SNOW SHOWERS OFF LAKE MICHIGAN TO IMPACT THE AIRPORT AFTER
12Z. GIVEN THE LOW CONFIDENCE AT THIS STAGE IN THE FORECAST...WILL
HOLD OFF ON INTRODUCING IFR TYPE CONDITIONS AT THIS TIME.
//DTW THRESHOLD THREATS...
* HIGH CONFIDENCE IN CEILING BELOW 5000 FT THROUGH THE TAF PERIOD.
* HIGH CONFIDENCE WESTERLY WIND GUSTS WILL EXCEED 28 KNOTS BETWEEN
06Z AND 19Z THURS.
&&
.PREV DISCUSSION...ISSUED 1007 PM EST WED JAN 30 2013
UPDATE...
THE WIDESPREAD RAIN WHICH HAS BEEN ROLLING ACROSS THE FORECAST
AREA THIS EVENING WILL QUICKLY LIFT OFF TO THE NORTHEAST OVER THE
NEXT COUPLE OF HOURS. RECENT OBSERVATIONS INDICATE THE BULK OF
THESE HEAVIER SHOWERS WILL BE OFF TO THE EAST PRIOR TO THE ARRIVAL
OF THE ARCTIC AIR AND CHANGE OVER TO SNOW. NONETHELESS...THE
ADVANCE OF DEEPER MOISTURE WITHIN THE MID LEVEL TROUGH AXIS WILL
ROTATE THROUGH THE FORECAST AREA OVERNIGHT PROVIDING SOME LIGHT
SNOW SHOWERS TO THE AREA. THE RESPONSE OFF LAKE MI FROM THE
AGGRESSIVE PUSH OF COLD AIR TONIGHT WILL ALSO BE QUITE GOOD. LAKE
ENHANCED SNOW SHOWERS SHOULD SUPPORT SOME HIGHER POPS ACROSS THE
SOUTHERN HALF OF THE FORECAST AREA OVERNIGHT. THE HIGHER INTENSITY
SNOW SHOWERS SHOULD HOLD OFF UNTIL AFTER DAYBREAK...SO SNOW ACCUMS
TONIGHT SHOULD BE MINOR. THE ARCTIC FRONT IS NOW ON THE DOORSTEP
OF THE FORECAST AREA AND WILL TRACK EAST OF THE AREA SHORTLY AFTER
MIDNIGHT. OVER THE NEXT TWO HOURS...TEMPS WILL RAPIDLY DROP BELOW
FREEZING. WHILE THE WINDS WILL HELP DRY THE ROAD SURFACES A
BIT...EXPECT THERE WILL SOME SLICK ROADS OVERNIGHT.
THE SURFACE LOW NOW OVER LAKE HURON WILL CONTINUE TO DEEPEN AS IT
PULLS NORTHEAST OF THE REGION OVERNIGHT. MEANWHILE...STRONG COLD
AIR ADVECTION WILL STEEPEN THE LOW LEVEL LAPSE RATES. THE MOST
RECENT RAP AND 18Z NAM CONTINUE TO SHOW A SOLID 40-45 KTS IN THE
MIXED LAYER OVERNIGHT /ESPECIALLY ACROSS THE EASTERN PORTIONS OF
THE FORECAST AREA/. THUS THE CURRENT WIND ADVISORY HEADLINE FOR
MUCH OF THE FORECAST AREA WILL REMAIN IN EFFECT.
PREV DISCUSSION...ISSUED 345 PM EST WED JAN 30 2013
SHORT TERM... TONIGHT
THERE ARE SEVERAL CONCERNS ASSOCIATED WITH THE FORECAST TONIGHT FOR
CONDITIONS THAT WILL HAVE AT LEAST MODERATE IMPACT AROUND SE
MICHIGAN. THE ADVISORY FOR HIGH WIND WILL BE MOST SIGNIFICANT
FOLLOWED CLOSELY BY THE COMBINATION OF FALLING TEMPERATURES AND RAIN
CHANGING TO SNOW ADDING A LAYER OF COMPLEXITY. ALL OF THIS WILL BE
DRIVEN BY A WAVE OF LOW PRESSURE THAT WILL MOVE FROM SOUTHWEST LOWER
MICHIGAN DURING THE AFTERNOON, THROUGH CENTRAL LAKE HURON AND INTO
EASTERN ONTARIO TONIGHT, ALL THE WHILE DEEPENING AS IT GOES.
THE DEEPENING TREND OF THE LOW AS IT PASSES TO OUR EAST WILL BE
FOSTERED BY THE DYNAMICS OF THE NEGATIVE TILT SHORT WAVE THAT IS
ALREADY TAKING SHAPE IN SATELLITE IMAGERY DURING THE AFTERNOON.
INCREASING SURFACE WIND TRAILING THE LOW IS ALSO OBSERVED TO PRODUCE
WIND GUSTS AROUND 30 KNOTS OVER THE MIDWEST AT PRESS TIME. WITH THE
SYSTEM ALREADY OFF TO A GOOD START, CONFIDENCE IS INCREASED IN THE
DEPICTIONS SHOWN IN THE ARRAY OF 12Z MODEL OUTPUT THAT BUILD A
STRONG WESTERLY WIND FIELD OVER SE MICHIGAN BY MIDNIGHT. SOME
GUSTINESS IS EXPECTED IN THE WARMER AIR AHEAD OF THE FRONT,
ASSOCIATED WITH THE LOW LEVEL JET, AND WITH THE ISALLOBARIC
COMPONENT OF FORCING IMMEDIATELY BEHIND THE FRONT, BUT THESE
ELEMENTS ARE NOT EXPECTED TO EXCEED ADVISORY CRITERIA. THAT IS
INSTEAD LIKELY TO OCCUR TOWARD MIDNIGHT THROUGH WEDNESDAY MORNING AS
DYNAMICALLY DRIVEN MID LEVEL SUBSIDENCE AND STRONG COLD ADVECTION
HELP DIRECT A 45-50 KNOT WIND FIELD TOWARD THE SURFACE FROM THE 850
TO 700 MB LAYER. MODEL CROSS SECTIONS INDICATE NEARLY 10 DEGREES(K)
OF THETA SURFACES INTERSECTING THE GROUND DURING THE INTERVAL OF
ISENTROPIC DECENT. MODEL SOUNDINGS THEN SHOW THE MIXED LAYER
DEEPENING TO NEAR THE 800 MB LEVEL FOR THE LATE OVERNIGHT HOURS WITH
45 KNOTS OF WIND AVAILABLE FOR CONTRIBUTION TO SURFACE WIND GUSTS.
AREAL COVERAGE WILL BE GREATEST ALONG AND SOUTH OF INTERSTATE 69
WITH THE THUMB VULNERABLE DUE TO WIND GUSTS MOVING OFF OF SAGINAW
BAY. PLAN TO LEAVE THE TRI CITIES OUT OF THE HEADLINE FOR NOW.
THE STRONG WINDS WILL PULL DRAMATICALLY COLDER AIR INTO SE MICHIGAN
DURING THE NIGHT WITH READINGS DROPPING INTO THE UPPER TEENS IN THE
TRI CITIES BY SUNRISE TO THE MID 20S METRO DETROIT. THE BULK OF
PRECIPITATION WILL COME IN THE FORM OF RAIN SHOWERS THROUGH MID
EVENING WITH THE CHANGE TO SNOW AT THE VERY TAIL END FOR JUST A
DUSTING OF ACCUMULATION IN THE DETROIT AREA AND UP TO AN INCH IN THE
NORTHERN THUMB.
LONG TERM...
LAKE MICHIGAN LAKE EFFECT MACHINE WILL BE CRANKING UP
THURSDAY...ENHANCED BY A GOOD UPPER LEVEL WAVE/MID LEVEL COLD POOL
SWINGING THROUGH THE MIDWEST/WESTERN OHIO VALLEY TOMORROW AFTERNOON.
STRONG WESTERLY WINDS (35-45 MPH) IN WAKE OF THE QUICKLY DEEPENING
LOW PRESSURE WILL USHER IN SUFFICIENTLY COLD AIRMASS...UPPER
NEGATIVE TEENS AT 850 MB OVER LOWER MICHIGAN...BUT LOWER NEGATIVE
20S SWINGING THROUGH THE WESTERN OHIO VALLEY. 700 MB COLD POOL OF
-28 TO -30 C OVER SOUTHERN LOWER MICHIGAN THURSDAY EVENING WITH
MODEST 925-850 MB LIFT/CONVERGENCE EXTENDING INTO SOUTHEAST
MICHIGAN...AND PLANNING ON CARRYING NUMEROUS POPS..ALTHOUGH FOCUS OF
ACTIVITY WILL LIKELY SHIFT FROM NORTH TO SOUTH THROUGH THE NIGHT AS
MODEST 850 THETA-E RIDGE SETTLES SOUTH. WITH A HIGH FLUFF FACTOR TO
SNOW...20+:1 RATIOS...A QUICK INCH OR TWO IS LIKELY IN SPOTS AS
925-850 MB PROFILES REMAIN IN THE DENDRITIC ZONE GROWTH REGION.
HEART OF THE COLD AIR/THERMAL TROUGH AXIS WILL BE IN PLACE FOR
FRIDAY...WITH 850 MB TEMPS HOVERING AROUND -20 C ON FRIDAY...AND
HAVE NO COMPLAINTS WITH INHERITED MAXES IN THE UPPER TEENS TO AROUND
20...IN LINE WITH LATEST GUIDANCE. A SURFACE RIDGE WILL ATTEMPT TO
MOVE IN FRIDAY NIGHT. IF THIS IS SUFFICIENT IN CLEARING OUT THE LOW
CLOUDS...LOOKING AT MINS AT OR BELOW ZERO FOR MUCH OF THE AREA WITH
EXPECTED FRESH SNOW COVER. CONFIDENCE IS NOT HIGH...AND WILL HAVE TO
PLAY IT CONSERVATIVE (LOW/MID SINGLE NUMBERS) AS THERE IS ALSO
LURKING WARM ADVECTION CLOUDS STREAMING INTO THE WESTERN GREAT
LAKES.
POLAR VORTEX LOOKS TO BE ANCHORED OVER/NEAR FAR NORTHERN HUDSON
BAY/SOUTHAMPTON ISLAND OVER THE NEXT SEVERAL DAYS...AND THIS WILL
MAINTAIN THE UPPER LEVEL NORTHWEST FLOW WITH A COUPLE
SHORTWAVES/CLIPPER SYSTEMS TO IMPACT OR TRACK NEAR SOUTHERN LOWER
MICHIGAN. WITH MOISTURE AT A PREMIUM...USUALLY NEED TO BE ON THE
NORTHEAST FLANK OF THE LOW (WARM ADVECTION/ISENTROPIC
ASCENT/MOISTURE CONVERGENCE) TO GET ANY SUBSTANTIAL
SNOWFALL. BEST GUESS AT TIMING OF SYSTEMS WOULD BE SATURDAY NIGHT
AND THEN AGAIN ON MONDAY. 12Z TRENDS OF EURO/GFS SUGGEST SATURDAY
NIGHTS SYSTEM WILL TRACK JUST A BIT TOO FAR SOUTH...WITH MONDAYS
SYSTEM/TRACK MORE FAVORABLE. THE EARLY NEXT WEEK LOW WILL ALSO HAVE
A BIT MORE OF A PACIFIC ORIGIN...AND THUS A BIT MORE MOISTURE. STILL
TOO EARLY TO GET A GOOD HANDLE OF THE GULF OF ALASKA ENERGY AND
EVENTUAL BREAKDOWN/SPILLING OVER INTO THE CONUS HOWEVER.
MARINE...
A POWERFUL COLD FRONT WILL SWEEP THROUGH LAKE HURON AND LOWER
MICHIGAN TONIGHT. INCREASING NORTHWEST WINDS AND A SURGE OF COLDER
AIR WILL BRING GALES TO ALL MARINE AREAS. CONSIDERABLE INSTABILITY
ACROSS THE LONG FETCH IN NORTHWEST FLOW OF THE OPEN WATERS WILL
MAINTAIN A LONGER PERIOD OF GALES FOR CENTRAL PORTIONS OF THE LAKE
THROUGH THURSDAY. THE COMBINATION OF THE STRONG WINDS, ARCTIC AIR,
AND COLDER WATER TEMPERATURE WILL LEAD TO HEAVY FREEZING SPRAY
ACROSS NORTHERN SECTIONS OF LAKE HURON DURING THIS TIME. HIGH
PRESSURE WILL SETTLE OVER THE OHIO VALLEY AND BRING IMPROVED
CONDITIONS BY FRIDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY...MIZ049-MIZ054-MIZ055-MIZ061-MIZ062-MIZ063-MIZ068-
MIZ069-MIZ070-MIZ075-MIZ076-MIZ082-MIZ083...UNTIL NOON
THURSDAY.
LAKE HURON...
GALE WARNING...LHZ361...UNTIL NOON THURSDAY.
HEAVY FREEZING SPRAY WARNING...LHZ361-LHZ362...UNTIL 7 PM THURSDAY.
GALE WARNING...LHZ362-LHZ363-LHZ462-LHZ463-LHZ464...UNTIL 7 PM
THURSDAY.
GALE WARNING...NEARSHORE WATERS FROM PORT AUSTIN TO PORT HURON
INCLUDING SAGINAW BAY...UNTIL 4 PM THURSDAY.
LAKE ST CLAIR...
GALE WARNING...UNTIL 4 PM THURSDAY.
MI WATERS OF LAKE ERIE...
GALE WARNING...UNTIL 4 PM THURSDAY.
&&
$$
AVIATION.....SC
UPDATE.......SC
SHORT TERM...BT
LONG TERM....SF
MARINE.......BT
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS HASTINGS NE
656 PM CST FRI FEB 1 2013
.UPDATE...EVENING UPPER AIR ANALYSIS INDICATES LONGWAVE TROUGHING
OVER THE EASTERN TWO-THIRDS OF THE CONUS...WITH RIDGING BUILDING
INTO THE WEST. MID AND UPPER LEVEL FLOW REMAINS FROM THE NORTHWEST
ACROSS THE CENTRAL PLAINS...MAXING OUT AT AROUND 70KTS NEAR 200MB
OVER OUR AREA. WATER VAPOR IMAGERY INDICATES A SUBTLE MID LEVEL
SHORT WAVE EXTENDING FROM THE DAKOTAS...SOUTHWEST INTO WESTERN
NEBRASKA AND SOUTHEASTERN WYOMING. AT THE SURFACE A WEAK AREA OF
BAROMETRIC PRESSURE EXISTS OVER EASTERN SOUTH DAKOTA...WITH A
TROUGH EXTENDING SOUTHWEST FROM THE LOW ACROSS PORTIONS OF
NEBRASKA AND KANSAS. THIS TROUGH PRETTY MUCH BISECTS OUR
CWA...WITH THE LOW LEVEL WIND FIELD ACROSS THE SOUTHEASTERN HALF
OF OUR CWA REMAINING FROM THE SOUTHWEST...AND LOCATIONS FARTHER
NORTHWEST NOW OBSERVING A SURFACE WIND FROM THE NORTHWEST. RADAR
DATA FROM KUEX...KLNX...AND KGLD ALL INDICATE LIGHT ELEVATED
PRECIPITATION EXTENDING FROM PORTIONS OF WESTERN NEBRASKA INTO
NORTHWESTERN KANSAS AND NORTHEASTERN COLORADO. REPORTS OF
PRECIPITATION ACTUALLY BEING REALIZED AT THE SURFACE HAVE BEEN FEW
AND FAR IN BETWEEN HOWEVER...WITH PROXIMITY SOUNDINGS FROM LAPS
AND RAP ANALYSIS INDICATING A VERY DRY LOWER TROPOSPHERE IS LIKELY
PREVENTING MUCH OF ANY PRECIPITATION FROM MAKING IT TO THE
SURFACE.
GUIDANCE FROM THE NAM...OPERATIONAL GFS...EC...SREF-MEAN...AND RAP
ALL SUGGEST THE MID LEVEL SHORT WAVE...CURRENTLY OVER THE NORTHERN
AND CENTRAL PLAINS...WILL CONTINUE MOVING SOUTHEAST TONIGHT...WITH
THE MID LEVEL TROUGH AXIS EXPECTED TO CLEAR OUR CWA SHORTLY AFTER
06Z. VERY WEAK MID LEVEL THERMAL ADVECTION AHEAD OF THE TROUGH
AXIS IS CREATING JUST ENOUGH OMEGA FOR THE ELEVATED PRECIPITATION
CURRENTLY BEING INDICATED BY AREA RADARS...WITH THIS AXIS OF WEAK
OMEGA EXPECTED TO CONTINUE PUSHING ACROSS OUR AREA TONIGHT AS THE
MID LEVEL TROUGH AXIS DOES THE SAME. THE BACK EDGE OF THIS OMEGA
AXIS IS APPARENTLY ALREADY WORKING INTO NORTHERN AND WESTERN
NEBRASKA...WITH KLNX INDICATING THE BACK EDGE ELEVATED
PRECIPITATION EXTENDING FROM NEAR KANW TO NEAR KIBM. GIVEN THE
CURRENT MOVEMENT OF THE MID LEVEL SHORT WAVE ON WATER VAPOR
IMAGERY...AND RADAR TRENDS THROUGH THE PAST 2-3 HOURS...IT APPEARS
THE BEST CHANCE FOR PRECIPITATION OVER OUR AREA WILL OCCUR BETWEEN
NOW AND 06Z...WITH DRY CONDITIONS LIKELY THEREAFTER AS THE MID
LEVEL TROUGH AXIS CLEARS THE AREA AND SUBSIDENCE SETTLES IN.
DESPITE THE RETURNS AS INDICATED BY AREA RADARS...ITS HARD TO
IGNORE THE VERY DRY LOWER TROPOSPHERE CURRENTLY IN PLACE AND THUS
IS SEEMS UNLIKELY MEASURABLE PRECIPITATION WILL BE REALIZED ACROSS
ANY OF OUR CWA TONIGHT. GIVEN THIS...WENT AHEAD AND PULLED POPS
FROM THE FORECAST FOR TONIGHT. THAT BEING SAID...CANNOT COMPLETELY
RULE OUT AN OCCASIONAL SPRINKLE MAKING IT TO THE SURFACE THROUGH
THE NEXT FEW HOURS AS THERE HAVE BEEN A FEW OBSERVATIONS ACROSS
WESTERN NEBRASKA WHICH INDICATED A BRIEF PERIOD OF PRECIPITATION
HERE OR THERE. GIVEN THE AFOREMENTIONED RADAR RETURNS AND
OBSERVATIONS...OPTED TO GO WITH A MENTION OF SPRINKLES ACROSS OR
SOUTHWESTERN CWA THROUGH THIS EVENING AS THE MOST ENHANCED AREA OF
RADAR RETURNS...AROUND 25DBZ...PUSH OVER THOSE AREAS.
PROXIMITY SOUNDINGS FROM ACROSS OUR CWA PER LAPS AND RAP ANALYSIS
INDICATE AN ELEVATED WARM LAYER DOES EXIST NEAR 850MB...WITH
FORECAST PROXIMITY SOUNDINGS PER THE NAM...OPERATIONAL GFS...AND
RAP SUGGESTING THIS ELEVATED WARM LAYER WILL REMAIN INTACT THROUGH
MUCH OF THE NIGHT. IF MORE SIGNIFICANT PRECIPITATION WERE EXPECTED
TO MAKE IT TO THE SURFACE...THIS WOULD CERTAINLY CREATE CONCERNS
WITH RESPECT TO FREEZING RAIN. THAT BEING SAID...BECAUSE THE RADAR
RETURNS THUS FAR THIS EVENING HAVE BEEN SO WEAK...AND BECAUSE THE
MAJORITY GUIDANCE SUGGESTS NO PRECIPITATION WILL BE REALIZED OVER
OUR AREA TONIGHT...AND BECAUSE THERE IS SUCH A DEEP LAYER OF LOWER
TROPOSPHERIC DRY AIR IN PLACE...AM NOT OVERLY CONCERNED WITH AN
ICING THREAT AT THIS TIME. SHOULD SPRINKLES BE REALIZED ACROSS
PORTIONS OF THE CWA AFTER 02Z TONIGHT...THEN TECHNICALLY THESE
WOULD BE FREEZING SPRINKLES AS SURFACE TEMPERATURES WILL HAVE
DROPPED BELOW FREEZING BY THEN. BUT AT THIS TIME THE THREAT OF
ICING FROM SUCH ACTIVITY IS LITTLE TO NONE AND GIVEN THIS...OPTED
TO PULL ANY MENTION OF FREEING RAIN FROM THE HWO.
REMAINDER OF THE FORECAST REMAINS IN GOOD SHAPE...WITH ONLY SOME
MINOR TWEAKS MADE TO HOURLY TEMPERATURE...SKY...WIND...AND
DEWPOINT GRIDS TO ACCOUNT FOR CURRENT OBSERVATIONS.
&&
.PREV DISCUSSION... /ISSUED 516 PM CST FRI FEB 1 2013/
AVIATION...00Z KGRI TAF. VFR CONDITIONS TO CONTINUE THROUGH THE
NEXT 24 HOURS. MID LEVEL CLOUDS GENERALLY BETWEEN 5000 AND 10000FT
AGL WILL BE POSSIBLE THROUGH MUCH OF THE TAF PERIOD. THE SURFACE
WIND WILL TRANSITION FROM THE SOUTHWEST TO THE NORTHWEST TONIGHT.
THE SURFACE WIND WILL ALSO INCREASE IN INTENSITY DURING THE DAY
SATURDAY...SUSTAINED AROUND 18KTS AND GUSTING NEAR 26KTS.
RESTRICTION IN VISIBILITY IS NOT EXPECTED THROUGH THE NEXT 24
HOURS.
PREV DISCUSSION... /ISSUED 324 PM CST FRI FEB 1 2013/
.A TROF EMBEDDED IN NW FLOW MAY DELIVER A LIGHT WINTRY MIX IN
SPOTS TNGT THEN WE DEAL WITH WINDY CONDITIONS N OF I-80 SAT...
SHORT TERM...TONIGHT AND SATURDAY
UPPER-LEVELS: A +PNA PATTERN WAS IN PLACE...WITH A WRN N AMERICA
RIDGE AND AN ERN TROF. A PAIR OF PV ANOMALIES WERE DIVING DOWN THE
BACK SIDE OF THE LGWV TROF. THE 1ST WAS OVER WY AT MID AFTN WITH THE
2ND OVER ALBERTA HEADING FOR MT. THE FIRST SHRTWV TROF WILL SLIDE
INTO AND THRU KS TNGT. THE SECOND WILL FOLLOW IT INTO NEB AFTER
MIDNGT. A SHRTWV RIDGE FOLLOWS SAT MRNG...WITH A THIRD PV ANOMALY
MISSING AND HEADING INTO IA...AS THE LGWV PATTERN PROGRESSES A BIT
AND HGTS RISE.
STRONG MO HIGH PRES WILL DEPART TO THE MID-ATLC STATES TNGT. THE
ARCTIC FRONT BISECTED NEB-KS. THIS FRONT AND ITS THERMAL RIBBON WERE
BEING SHOVED E BY SW FLOW AHEAD OF A VERY WEAK SFC LOW. THIS LOW
TRACKS JUST N OF THE FCST AREA...TO THE MS RIVER BY DAYBREAK SAT.
HIGH PRES FOLLOWS HERE TOMORROW.
TNGT: VARIABLE CLOUDS BUT OVERALL EXPECT SKIES TO AVERAGE M/CLOUDY.
EXPANDED THREAT OF VERY LIGHT PCPN TO THE ENTIRE FCST AREA AND WE
NOW HAVE CHANCE POPS FOR AREAS NE OF THE TRI-CITIES AND FROM HWY
136 DOWN INTO N-CNTRL KS. ODDS ARE MOST PLACES REMAIN DRY WITH
LACK OF MSTR IN THE SUB-CLOUD LAYER...BUT WAS NOT COMFORTABLE WITH
AN ENTIRELY DRY FCST.
NEXT ISSUE IS PCPN TYPE. BOTH DDC/LBF HAD A WARM NOSE IN 12Z
SOUNDINGS. NAM/GFS BUFKIT SOUNDINGS SUGGEST 850 MB HAS WARMED TO
+3C OVERHEAD THIS AFTN. SO "IF" PCPN FALLS TNGT...PLAYED IT AS
FLURRIES OR A BRIEF SNOW SHWR NE OF THE TRI-CITIES...FLURRIES OR
SPRINKLES IN THE TRI-CITIES...AND SPRINKLES AND POSSIBLY A RAIN
SHWR S OF HWY 6 INTO N-CNTRL KS. THAT SAID...BELOIT IS STILL SUB-
FRZG AND THE REST OF N-CNTRL KS NOT MUCH ABOVE FRZG. IF TEMPS
COOL BACK DOWN BELOW FRZG AND A FEW -SHRA OCCUR...THERE COULD BE A
TOUCH OF GLAZE. THE LOW PROBABILITY THREAT IS NOW OUTLOOKED IN THE
HWO.
BEST CHANCE OF PCPN WILL OCCUR 9PM-3AM.
USED BURST OF PW AND K-INDEX TO ASSIST IN TIMING/LOCATION OF POPS
THRU THE FCST AREA. CHANCE POPS S OF HWY 136 WERE BASED ON HI-RES
MODEL REFLECTIVITY WHICH IS SUPPORTED BY THE TRACK OF THE PV
ANOMALY.
TEMPS: VARIABLE CLOUD COVER LOWERS CONFIDENCE SOMEWHAT...BUT
OVERALL THINK IT WILL BE A MILD NGT. TEMPS ARE BIAS CORRECTED
BLEND OF 2M TEMPS AND THE PREVIOUS GID FCST /21-27F/.
SAT: SKIES SHOULD BE P/CLOUDY S AND W OF THE TRI-CITIES AT DAWN...
AND M/CLOUDY N AND E. CLEARING AS THE DAY PROGRESSES AND WINDY N OF
I-80 IN THE "WARM" SECTOR OF THE NEXT PV ANOMALY AND CLIPPER FCST
OVER IA.
WIND: THERE IS A LOW PROBABILITY WE MAY NEED A WIND ADVISORY FOR
SOME OF OUR COUNTIES N OF I-80. SUBJECTIVE PROBABILITY PUTS IT
AROUND 40 PERCENT. WITH THE STRENGTH OF THE LOW-LEVEL WIND
FIELDS...BUFKIT MIXING HGTS ARE UNNERVING FROM BOTH THE NAM/GFS.
FOR NOW WE/VE INCLUDED G40 MPH IN THE FCST. THE MAIN CORE OF THE
STRONGEST WIND MOVES IN AFTER 21Z. THE 15Z SREF MEAN INCREASES
SPEEDS 40-45 KTS 21Z-00Z. THIS COINCIDES WITH PEAK HEATING AND
WILL NEED TO BE CONSIDERED BY THE MID SHIFT.
TEMPS ARE BIAS CORRECTED MOS GUIDE WITH SOME ADDITIONAL LOWERING
OF TEMPS OVER THE SNOW COVER S AND E OF HASTINGS AND SOME RAISING
FROM LXN DOWN TO THE KS BORDER...WHERE BIAS CORRECTION PROBABLY
CUT TEMPS TOO MUCH.
LONG TERM...SATURDAY NIGHT THROUGH FRIDAY. BEGINNING SATURDAY
NIGHT...A NORTHWEST FLOW PATTERN WILL BE IN PLACE ACROSS THE CENTRAL
PLAINS AND SHORTWAVE ENERGY IS PROGGED TO TRANSLATE SOUTHEAST ALONG
THE MISSOURI RIVER. COLD AIR BACKS IN BRIEFLY FOR THE OVERNIGHT
TIME FRAME...THEN IN RETURN FLOW ON SUNDAY THE AIRMASS MODERATES
BEHIND THE DEPARTING WAVE. THE NORTHWEST FLOW PATTERN REMAINS
PROGRESSIVE THROUGH MID WEEK WEEK WITH A SERIES OF WAVES TRANSLATING
THRU FLOW...MAINLY ALONG AND EAST OF THE MISSOURI RIVER...WHICH WILL
BRING A FEW COLD FRONTS ACROSS THE PLAINS WITH THE BRUNT OF THE
COOLER AIR REMAINING TO OUR EAST. IN THIS REGIME WE WILL SEE
ALTERNATING PERIODS OF WAA/CAA BUT WITH CONDITIONS REMAINING DRY.
AROUND MID WEEK...THE RIDGING OVER THE ROCKIES BREAKS DOWN AND
SETTLES ONTO THE PLAINS ALLOWING FOR A PROGRESSIVE BUT MORE ZONAL
FLOW PATTERN. EXTENDED MODELS ARE FAIRLY CONSISTENT WITH YET
ANOTHER SHORTWAVE TROUGH TO CROSS THE NORTHERN AND CENTRAL PLAINS
WEDNESDAY NIGHT...AND MODELS ARE HINTING THAT FRONT MAY BECOME
ACTIVE WEDNESDAY NIGHT NEAR OUR SOUTHEAST ZONES. CONFIDENCE IN PCPN
THIS FAR OUT IS NOT HIGH AND WILL CONTINUE TO MONITOR. ONCE THIS
WAVE DEPARTS...AN UPPER RIDGE SETTLES ACROSS THE INTERIOR CONUS
WHILE AN UPSTREAM TROUGH MOVES INTO THE ROCKIES. THE WEATHER
PATTERN LOOKS TO BECOME MORE ACTIVE NEXT WEEKEND WITH THE
PROGRESSION OF THE WESTERN TROUGH AND THIS WILL BE SOMETHING TO KEEP
AN EYE ON. UNTIL THAT TIME FRAME HOWEVER...LOOK FOR MAINLY DRY
CONDITIONS WITH TEMPS ABOVE NORMAL FOR THE MOST PART...ESPECIALLY
AFTER THE SNOW MELTS IN OUR EASTERN ZONES.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
0656 PM UPDATE/AVIATION...BRYANT
SHORT TERM...HALBLAUB
LONG TERM...FAY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1126 PM CST WED JAN 30 2013
.AVIATION...06Z KGRI TAF...AN APPROACHING UPPER LEVEL DISTURBANCE
WILL SPREAD MVFR CIGS ACROSS THE TERMINAL BY THE EARLY MORNING
HOURS THURSDAY...WITH A FEW SNOW FLAKES NOT OUT OF THE QUESTION.
ALREADY SEEING MVFR CIGS TO THE NORTHWEST AT KVTN WITH SOME
-SN...AND EXPECT THIS CLOUD COVER TO REACH KGRI AROUND
31/12Z...AND PERSIST THROUGH AROUND 31/18Z. WINDS WILL THE PRIMARY
FOCUS THROUGH THE DAY THURSDAY AS AN AREA OF SURFACE HIGH PRESSURE
OVER THE DAKOTAS SLIDES SOUTHWARD...RESULTING IN A TIGHTENING
PRESSURE GRADIENT. EXPECT WINDS TO GUST AS HIGH AS 30KTS DURING
THE AFTERNOON HOURS...BEFORE RAPIDLY DIMINISHING AROUND
01/00Z...AS THE CENTER OF THIS HIGH PRESSURE SYSTEM REACHES
EASTERN NEBRASKA.
&&
.PREV DISCUSSION... /ISSUED 956 PM CST WED JAN 30 2013/
UPDATE...EVENING UPPER AIR ANALYSIS PER RAP ANALYSIS DATA
SUGGESTS A LARGE MID AND UPPER LEVEL LONGWAVE TROUGH PERSISTS OVER
THE CENTRAL CONUS. MID AND UPPER LEVEL JET ENERGY EXTENDS
SOUTH/SOUTHEAST ACROSS THE WESTERN CONUS...THEN EAST ACROSS THE
SOUTHERN PLAINS...AND EVENTUALLY NORTHEAST ACROSS THE EASTERN ONE-
THIRD OF THE CONUS. ALTHOUGH MID AND UPPER TROPOSPHERIC FLOW HAS
BEEN FAIRLY WEAK OVER OUR AREA THROUGH THIS EVENING...THE MID
LEVEL WIND FIELD IS INTENSIFYING WITH THE APPROACH OF A ~80KT MID
LEVEL JET STREAK FROM THE NORTHWEST. WATER VAPOR IMAGERY INDICATES
FAIRLY MEAGER MID LEVEL MOISTURE OVER OUR AREA...ALTHOUGH SOME
MODEST INCREASE IN MID LEVEL MOISTURE IS NOTED ADVECTING INTO THE
AREA FROM THE NORTHWEST VIA THE MID LEVEL JET AXIS. A MID LEVEL
SHORT WAVE IS ALSO NOTED OVER PORTIONS OF SOUTHERN MANITOBA AND
SOUTHERN ONTARIO...MOVING SOUTH/SOUTHEAST WITHIN THE MEAN FLOW. AT
THE SURFACE LOW BAROMETRIC PRESSURE IS NOTED OVER PORTIONS OF
CENTRAL NEBRASKA...WITH RAPIDLY INCREASING BAROMETRIC PRESSURE
NOTED UPSTREAM ACROSS THE DAKOTAS AND PORTIONS OF MONTANA. THE LOW
LEVEL WIND FIELD OVER OUR AREA REMAINS FAIRLY LIGHT BUT STILL FROM
THE NORTHWEST FOR THE MOST PART.
GUIDANCE FROM THE NAM...OPERATIONAL GFS...EC...AND SREF-MEAN ALL
SUGGEST THE MID LEVEL SHORT WAVE...CURRENTLY ADVANCING
SOUTH/SOUTHEAST FROM SOUTHERN CANADA...WILL CONTINUE MOVING
SOUTHEAST ACROSS PORTIONS OF THE NORTHERN PLAINS AND UPPER
MISSISSIPPI VALLEY THROUGH THE NEXT 18-24 HOURS. IT APPEARS AS
THOUGH THE PRIMARY AXIS OF OMEGA AHEAD OF THE MID LEVEL TROUGH
AXIS WILL REMAIN NORTHEAST OF OUR AREA...ALTHOUGH THE SOUTHWESTERN
PERIPHERY OF THE MID LEVEL TROUGH AXIS COULD EXTEND JUST FAR
ENOUGH SOUTHWEST TO CLIP NORTHEASTERN PORTIONS OF OUR CWA AND
GENERATE SOME VERY LIGHT PRECIPITATION TONIGHT. FORECAST PROXIMITY
SOUNDINGS FROM ACROSS OUR CWA...PER THE NAM AND OPERATIONAL
GFS...SUGGEST LOW TO MID TROPOSPHERIC MOISTURE WILL LIKELY REMAIN
TOO MEAGER FOR SIGNIFICANT PRECIPITATION PRODUCTION...BUT STILL
CANNOT RULE OUT A FEW SNOW FLURRIES ACROSS OUR NORTHEAST.
OVERALL THE GOING FORECAST IS IN GREAT SHAPE...BUT DID GO AHEAD
AND TRIM THE MENTION OF FLURRIES ACROSS OUR CWA...AND THIS MENTION
IS NOW RELEGATED TO OUR FAR NORTHEASTERN CWA. FORECAST OVERNIGHT
LOWS ALSO LOOK GOOD FOR THE TIME BEING...GENERALLY IN THE TEENS
WITH THURSDAY MORNING APPARENT TEMPERATURE VALUES APPROACHING -10
ACROSS OUR NORTHEAST AROUND SUNRISE. ALL OTHER CHANGES WERE TO
HOURLY TEMPERATURE...WIND...SKY...AND DEWPOINT GRIDS TO BETTER
REFLECT CURRENT CONDITIONS.
PREV DISCUSSION... /ISSUED 423 PM CST WED JAN 30 2013/
SHORT TERM...TONIGHT AND THURSDAY. WE WILL BE WITHIN NORTHWEST
FLOW...BETWEEN THE MEAN TROUGH IN THE EAST AND RIDGE ON THE WEST
COAST. ANOTHER SHORTWAVE TROUGH SWINGS TROUGH LATE TONIGHT/EARLY
THURSDAY MORNING TO GIVE US A SHOT AT SOME FLURRIES...ESPECIALLY
NORTH. SREF INDICATING SOME SPOTTY LOW CHANCES OF ACCUMULATING
PRECIPITATION...BUT LEANING TOWARDS FLURRIES WITH THE DRY LOWER
LEVELS. SOME VORTICITY HOLDS ON LONGER IN THE SOUTH...SO KEPT SOME
SLIGHT CHANCES OF FLURRIES THERE THROUGH THE ENTIRE MORNING.
STRONG COLD AIR ADVECTION IS ADVERTISED AS SURFACE HIGH PRESSURE
BUILDS IN TOMORROW. WITH ANTICIPATED CONSIDERABLE SKY COVER FOR MOST
OF THE DAY AND 18Z 850 MB TEMPS NEAR -20C NEAR ORD TO -10C IN THE
SOUTHERN CWA...TEMPERATURES WILL NOT GO VERY FAR...SO HAVE LOWERED
TEMPERATURES CONSIDERABLY FOR THURSDAY...ESPECIALLY NORTH. THE WIND
WILL BECOME BRISK AGAIN FOR THURSDAY WITH THE STRONG COLD AIR
ADVECTION....WITH PLACES NEAR 0RD APPROACHING -15F IN THE EARLY
MORNING THURSDAY. SNOW PACK MAY HAVE SOME AFFECT ON
TEMPERATURES...BUT MOST OF THE CHILL WILL BE FROM THE COLD AIR
ADVECTION ANTICIPATED.
LONG TERM...THURSDAY EVENING THROUGH NEXT WEDNESDAY. THE SHORT
STORY THROUGH THIS 6-DAY PERIOD IS THAT THE FORECAST REMAINS
PRECIPITATION FREE...ALTHOUGH WILL HAVE TO WATCH FOR THE POTENTIAL
FOR SOME PESKY FLURRIES OR VERY LIGHT SNOW DEVELOPMENT FRIDAY/FRIDAY
NIGHT MAINLY NORTHEAST. OTHERWISE...TEMPERATURES WILL BE A
CONSIDERABLE CHALLENGE ESPECIALLY FRIDAY-SATURDAY AS WARMER AIR
MOVING IN FROM THE WEST STARTS A FIERCE BATTLE WITH THE
RESPECTABLE 1-5 INCH SNOW PACK NOW BLANKETING THE SOUTHEAST 1/2 OF
OUR CWA. OVERALL THOUGH...LEGITIMATELY ABOVE NORMAL TEMPERATURES
IN THE 40S/50S LOOK TO DOMINATE THE EARLY-MIDDLE PART OF NEXT
WEEK.
STARTING OFF THURSDAY NIGHT...MODELS SUCH AS THE 12Z NAM/GFS/ECMWF
ARE IN GOOD AGREEMENT THAT THE VERY BEGINNING STAGES OF MODEST
WARM AIR ADVECTION WILL START GETTING UNDERWAY IN THE LOW
LEVELS...AS THE COLD MID/UPPER TROUGH EDGES FARTHER EAST AWAY FROM
THE CENTRAL PLAINS. AT THE SURFACE...THE CWA WILL BE NEAR OR JUST
WEST OF A FAIRLY STRONG SURFACE RIDGE AXIS CENTERED OVER THE MO
VALLEY THROUGH THE FIRST PART OF THE NIGHT...WHILE SOUTHERLY
BREEZES OF AROUND 10 MPH WILL KICK INTO GEAR LATER IN THE NIGHT IN
THE RETURN FLOW AROUND THE DEPARTING HIGH. AS A RESULT...DEPENDING
ON CLOUD COVER TEMPS COULD REALLY DIP IN THE EVENING BEFORE
EXHIBITING A SLIGHT LATE-NIGHT RISE. CLOUD TRENDS WILL BE A BIT
TRICKY...AS MODELS SHOW THE POTENTIAL FOR A TRANSIENT BAND OF MID
LEVEL SATURATION WORKING ACROSS THE CWA FROM WEST-EAST THROUGH THE
NIGHT. ALTHOUGH ITS NOT OUT OF THE QUESTION A FEW FLURRIES COULD
TRY FORMING FROM THIS...CHANCES LOOK LOW ENOUGH TO LEAVE OUT AT THIS
TIME. AS FOR ACTUAL LOW TEMPS...LOWERED EAST-NORTHEAST ZONES A BIT
FROM PREVIOUS FORECAST. NOW HAVE LOWS DOWN IN THE SINGLE DIGITS
ABOVE ZERO MOST AREAS...EXCEPT FOR A 10-15 RANGE FAR SOUTHWEST
WHERE THE SOUTH WINDS KICK IN A BIT SOONER.
FRIDAY/FRIDAY NIGHT...AS ALREADY MENTIONED WILL NEED TO MONITOR
FOR SOME LOW-IMPACT FLURRY/VERY LIGHT SNOW ACTIVITY ESPECIALLY IN
NORTHEAST COUNTIES AS A LOW AMPLITUDE SHORTWAVE TROUGHS DROPS
OVERHEAD IN WEST-NORTHWEST FLOW ALOFT...BUT WITH THIS STILL BEING 4-5
PERIODS OUT AM CONTENT LEAVING IT OUT FOR NOW...AND LET LATER
SHIFTS TAKE A CLOSER LOOK. NO MATTER WHAT...THE MUCH BETTER FOCUS
FOR POTENTIALLY MEASURABLE SNOW WILL FOCUS WELL EAST INTO IA. HIGH
TEMPS FRIDAY ARE REALLY GOING TO BE A CHALLENGE...ESPECIALLY ALONG
THE INTERFACE BETWEEN THE NEARLY SNOW-FREE GROUND AND THE DEEPER
SNOWPACK. BREEZY SOUTHWEST WINDS SHOULD HAVE NO PROBLEM BOOSTING
ROUGHLY THE WESTERN HALF OF THE CWA WELL INTO THE 40S...WHILE EASTERN
AREAS COULD STAY WELL DOWN IN THE LOW-MID 30S. CONFIDENCE IN THE
MAGNITUDE OF THIS GRADIENT IS FAIRLY LOW AT THIS TIME. LOWS FRIDAY
NIGHT ARE FORECAST QUITE A BIT WARMER THAN THURS NIGHT THANKS TO
DEVELOPING WESTERLY FLOW BEHIND A PASSING TROUGH AXIS...AND HAVE
ALL AREAS HOLDING UP IN THE LOW-MID 20S.
SATURDAY/SATURDAY NIGHT...CONTINUED WEST-NORTHWEST DOWNSLOPE LOW
LEVEL FLOW SHOULD AID THE CONTINUED WARM-UP...AND MADE LITTLE
CHANGE TO HIGHS WITH MOST OF THE CWA REACHING THE MID-UPPER
40S...EXCEPT FOR LOW 40S IN THE FAR SOUTHEAST ESPECIALLY AROUND
HEBRON WHERE THE DEEPER SNOW EXISTS.
SUNDAY/SUNDAY NIGHT...CONFIDENCE REMAINS FAIRLY HIGH IN DRY
CONDITIONS...DESPITE THE PASSAGE OF ANOTHER QUICK MOVING SHORTWAVE
TROUGH IN THE PERSISTENT WEST/NORTHWEST FLOW ALOFT. THE ONLY REAL
IMPACT FROM THIS WAVE AT THE SURFACE WILL BE THE PASSAGE OF
ANOTHER MODEST SURFACE TROUGH MAINLY SUNDAY NIGHT. FOR
HIGHS...ANTICIPATE THAT THE SNOWPACK-EFFECTS SHOULD BE TEMPERED A
BIT VERSUS FRIDAY/SATURDAY...SO HAVE A BIT MORE UNIFORM
TEMPERATURE FIELD...WITH UPPER 40S/LOW 50S MOST AREAS EXCEPT MID
40S IN THE SOUTHEAST.
MONDAY/MONDAY NIGHT...CONTINUED NORTHWESTERLY FLOW ALOFT AS A
BROAD RIDGE STARTS BUILDING EASTWARD OVER THE WESTERN CONUS A BIT.
THE PREFERRED ECWMF SOLUTION KEEPS ANY PRECIP-PRODUCING SHORTWAVE
ENERGY WELL EAST OF THE LOCAL AREA ALONG AN AXIS FROM THE DAKOTAS
THROUGH IA. WITH LITTLE CHANGE IN THE LOW LEVEL TEMP FIELDS...HAVE
HIGHS SIMILAR TO SUNDAY WITH MOST AREAS UPPER 40S TO LOW 50S.
TUESDAY/TUESDAY NIGHT...CONTINUED DRY AS A BRIEF PERIOD OF
MID/UPPER RIDGING TRANSLATES OVERHEAD...AND AGAIN VERY SIMILAR
HIGH TEMPERATURES AS PREVIOUS FEW DAYS WITH UPPER 40S MOST NEB
ZONES AND LOW-MID 50S KS.
WEDNESDAY...STILL NO LEGITIMATE SIGN OF PRECIP...AS MODELS
ADVERTISE FAIRLY UNEVENTFUL QUASI-ZONAL FLOW AT THIS TIME. ONCE
AGAIN...HIGHS RANGING UPPER 40S NORTHEAST TO MID-50S SOUTHWEST.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
240 PM EST THU JAN 31 2013
.SYNOPSIS...
COLDER AIR WORKING INTO THE AREA BEHIND A STRONG COLD FRONT WILL
PRODUCE STRONG GUSTY WINDS TODAY...IN ADDITION TO LAKE EFFECT
SNOWS DOWNWIND OF LAKES ERIE AND ONTARIO. BELOW NORMAL
TEMPERATURES AND SCATTERED SHOW SHOWERS WILL CONTINUE INTO THE
WEEKEND...DUE TO A COMBINATION OF LAKE EFFECT SNOW SHOWERS AND
WEAK UPPER LEVEL DISTURBANCES.
&&
.NEAR TERM /THROUGH TONIGHT/...
12 NOON UPDATE... WE`VE PUSHED BACK THE START TIME OF THE LES WRNG
BY A FEW HRS IN NRN ONEIDA (NOW 21Z). BASED ON THE LATEST KBUF VWP
(STILL A 260 FLOW OVER A DEEP LYR)...AND OVERALL RADAR
PRESENTATION...WE THINK THE ONSET OF THE +SN IN NRN ONEIDA WILL BE
SOMEWHAT DELAYED FROM OUR EARLIER FCST. THE AMTS STILL LOOK
REPRESENTATIVE...AS PARAMETERS SEEM FAVORABLE FOR FAIRLY INTENSE
RATES...ONCE THE SNOW DOES FINALLY MOVE IN.
10 AM UPDATE... OUR CURRENT FCST IS IN EXCELLENT SHAPE ATTM...SO
ONLY COSMETIC CHGS WERE MADE.
AS STG CAA CONTS TO FILTER ACRS THE FA LATE THIS MRNG...LES BANDS
ARE TRYING TO ORGANIZE OFF BOTH LKS ERIE AND ONT. AS JUDGED FROM
THE 12Z RAOBS AT BUF/DTX...THE MIXED LYR EXTENDS UP TO ABT 750
MB...WITH A FAIR MOISTURE SUPPLY UNDERNEATH THE BASE OF THE
INVERSION. GIVEN CONTD CYCLONIC FLOW...FURTHER COOLING WITH
TIME...AND IF ANYTHING...A DEEPENING OF THE SYNOPTIC MOISTURE THIS
AFTN AND EVE...THERE`S NO REASON NOT TO EXPECT THE DVLPMT OF
FAIRLY STG LAKE-EFFECT PLUMES OFF BOTH LKS.
IN-HOUSE CAPE/SHEAR NOMOGRAM SHOWS ENUF OVER-LAND INSTAB THROUGH
THIS EVE (00-03Z)...SO THAT THE BANDS MAY TAKE ON SOMEWHAT OF A CELLULAR
APPEARANCE...AT TIMES. HOWEVER...ORGANIZATION IS NOT LIKELY TO BE
SERIOUSLY COMPROMISED. ALSO...THE CSTAR-DERIVED INLAND EXTENT
APPLICATION DEPICTS A FAIRLY DEEP INLAND PENETRATION THROUGHOUT
THE EVE HRS...AT LEAST...WITH A GOOD UPSTREAM CONNECTION TO
HURON/NRN LK MI/SUPERIOR...AND ALSO STG 0-1 KM SPEED SHEAR. THIS
ALSO SEEMS WELL SUPPORTED BY SIM REFLECTIVITY PRESENTATIONS FROM
THE NAM12...LOCAL ARW...AND HRRR MODELS.
BOTTOM LN...THINGS APPEAR WELL ON TRACK FOR THE LES WRNG IN NRN
ONEIDA...WITH A PD OF VERY HVY SNOW ANTICIPATED...FROM ROUGHLY
22-06Z. GIVEN DEEP MOISTURE...AND EXCELLENT CRYSTAL GROWTH
PARAMETERS...2-3"/HR RATES ARE NOT OUT OF THE QUESTION. ELSEWHERE
(ONONDAGA/MADISON/SRN ONEIDA)...DESPITE SOME ANTICIPATED
WEAKENING LTR TNT...AS THE BAND DROPS SWD...THERE MAY BE ENUF
RESIDUAL INTENSITY FOR ADVSY-LVL ACCUMS. WE`LL RE-VISIT THIS SITN
EARLY THIS AFTN.
ACRS THE TWIN TIERS...SOME CONVECTIVE SHSN ARE LIKELY TO FORM BY
MID TO LATE AFTN...AIDED A BIT BY ADVECTION OF MOISTURE FROM LKS
ERIE AND SRN MI IN STG WRLY FLOW. OVERALL...THOUGH...THE NATURE OF
THEM WILL REMAIN SCTD.
AS FOR THE WINDS...THEY`RE LIKELY TO BE AT THEIR PEAK THROUGH ABT
18Z...WITH A SLOW DIMINISHING TREND THEREAFTER...AS JUDGED FROM
ISALLOBARIC AND MOMENTUM TRANSFER PROGS.
A STEADY OR SLOWLY FALLING TEMP TREND IS WELL HANDLED IN THE
GRIDS...SO ONLY VERY MINOR TWEAKS WERE NEEDED.
PREV DISC... 620 AM...WILL DROP THE FLOOD WATCH FOR ERN ZONES AS
STEADY RAIN IS MOVG OUT. OTRW JUST MINOR NEAR TERM TWEEKS WITH NO
SIG CHGS TO FCST. PREV BLO...
450 AM...DROPPED FLOOD WATCH FOR THE CNTRL SRN TIER AND PORTIONS
OF THE FINGER LAKES AS BACK EDGE OF STEADIER RAIN HAS EXITED THIS
RGN. MAY STILL SEE SOME MINOR FLOODING DUE TO RUNOFF BUT FLS`S
HANDLING THAT. CONVECTIVE FNTL LINE PRODUCED WIND GUSTS IN THE
40-50 MPH RECENTLY AT SYR/BGM. SYNOPTIC SCALE WINDS WILL BE
INCRSNG RAPIDLY LATER THIS MRNG ALL AREAS. PREV BLO...
BACK EDGE OF AREA OF STEADY RAIN AREA MOVING INTO WRN ZONES AS OF
315 AM...CLOSE TO THE PSN OF THE SFC CDFNT...AND WILL CONTINUE IT`S EWD
PROGRESS THROUGH THE EARLY MRNG HRS. SOME OF THE RAIN MAY MIX
BRIEFLY WITH SNOW BEFORE TAPERING OFF THIS MRNG. FLOOD WATCH
REMAINS ON EFFECT...WE HAVE ISSUED SOME FLS`S THUS FAR AND WILL
CONTINUE TO MONITOR CAREFULLY.
MAIN ISSUE TDA WILL BE THE STRONG WINDS DVLPNG THIS MRNG AND
CONTINUING INTO THE AFTN HRS. BASED ON OUR SUSTAINED AND PEAK WIND
GRIDS...WE ADDED STEUBEN...YATES AND SENECA COUNTIES INTO THE
WARNING.
SCATTERED SNOW SHOWERS ARE XPCTD TDA...MAINLY DUE TO LAKE
INFLUENCES. WE COULD SEE -SHSN OFF LAKE ERIE ACRS PORTIONS OF THE
TWIN TIERS THIS AFTN/EVNG. POTNL FOR 2-4 INCHES ACRS PORTIONS OF
WRN STEUBEN TNGT. AFTN SHIFT CAN RE-ASSESS AND DETERMINE IF A LOW
END ADVISORY IS NEEDED HERE.
AS FOR THE NRN ONEIDA LES EVENT...THIS EVENT APPEARS TO BE SIMILAR
TO LAST WEEKS. THE ARW PERFORMED WELL IN THAT CASE...AND THIS
MRNG`S RUC ALSO SHOWS GOOD AGREEMENT EARLY ON IN THE PD. IT
APPEARS THAT THE BAND WILL NOT MAKE A MOVE INTO NRN ONEIDA UNTIL
LATE THIS AFTN...PERSISTING OVER THAT AREA TIL ARND 06Z BEFORE
DROPPING SWD AS FLOW BCMS MORE WNWLY. AS THIS OCCURS...MESO MDLS
SHOW THE BAND OVER LAKE ONTARIO DROPPING TO A PSN NEAR/ALONG THE
SRN SHORE OF LAKE ONTARIO LATE TNGT/TWDS DAYBREAK. THIS IS WHAT
OCCURRED WITH THE LAST BAND...AND RESULTED IN RAPID WEAKENING OF
THE BAND OVER THE BGM CWA DUE (AT LEAST IN PART) TO THE LOSS OF
OVER-LAKE TRAJECTORY. THIS IS ALSO HINTED AT IN THE MESO MDLS FRI
MRNG. FOR NOW WE HAVE THE BAND DROPPING SWD INTO ONON/MAD IN THE
09-12Z TIME FRAME...WITH POTNL FOR LOW END ADVISORY ACCUMS MAINLY
OVER NW ONON. GIVEN THE NUMEROUS HEADLINES ALREADY IN EFFECT AND
THE FACT WE HAVE SOME TIME TO TAKE A CLOSER LOOK AT THIS...WE WILL
JUST MENTION THE POTNL IN THE HWO AND LET THE DAY SHIFT ISSUE
HEADLINES FOR THIS EVENT IF NEEDED.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
A COUPLE OF CLIPPER-TYPE SYSTEMS WILL AFFECT THIS WEEKEND...WITH
SCATTERED SNOW SHOWERS. A MORE WDSPRD AREA OF LGT SNOW COULD DVLP
IN THE WARM ADVECTION PTRN AHEAD OF THE CLIPPER APRCHNG SAT NGT.
IN GNRL...CHC POPS FOR -SHSN AND BLO NORMAL TEMPS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
230 PM UPDATE...
LK EFFECT SNOW WL START OFF THE LONG TERM AS SYSTEM EXITS OFF OF THE
EAST COAST. NW FLOW WL BRING CLD AIR ACRS THE LKS ALONG WITH NEAR
SEASONAL TEMPS. CLIPPER TYPE LOW WL MV THRU THE UPR MIDWEST AND
MID-ATLANTIC SPREADING LIGHT SNOW INTO THE REGION ON TUESDAY. 12Z
MED RANGE GUIDANCE SHOWS SLIGHT DISCREPANCIES IN HOW FAR NORTH
CLIPPER TRACKS ON MON NGT INTO TUESDAY. WITH GFS BEING FURTHER NORTH
AND EC SUPPRESSED FURTHER TO THE SOUTH, HV SIDED WITH HPC GUIDANCE
WITH LOW-MID RANGE CHC POPS FOR THIS TIME PD. SYSTEM WL SKIRT TO THE
SOUTH AS HIPRES WL BUILD IN FM THE NORTH. HV ASSIGNED LOCHC POPS TO
THE ENTIRE AREA FOR TUE NGT THEN THINKING IT WL TRANSITION TO A LGT
LES EVENT ACRS FINGER LKS REGION WITH JUST FLURRIES ELSEWHERE. SFC
HIPRES WL BUILD IN WED NGT AND THURSDAY. L/WV TROF FCST TO DROP INTO
THE PLAINS TWD THE END OF THE PD WITH LIGHT SNOW SPREADING INTO CWA
BY 12Z FRIDAY.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
18Z UPDATE...
SNOW HAS MOVED INTO ALL TERMINALS BEHIND COLD FRONT. WITH
SCATTERED SNOW SHOWERS, CONDS WILL RANGE FROM VFR TO MVFR THOUGH
AN OCCASIONAL IFR CANNOT BE RULED OUT. AS LAKE EFFECT BAND GETS
ORGANIZED IFR VSBYS WILL MOVE INTO KRME AFTER 03Z AND KSYR AFTER
09Z. AT KELM AND KITH EXPECT MVFR CONDS TONIGHT WITH FLOW OFF OF
LAKE ERIE THOUGH KBGM AND KAVP SHOULD REMAIN LOW VFR.
WINDS OUT OF THE SOUTHWEST THIS AFTERNOON AROUND 25KTS WILL GUST
TO 30-40KTS. WINDS WILL REMAIN GUSTY NEXT 24 HOURS THOUGH GUSTS
WILL LESSEN TO AROUND 25KTS AND GRADUALLY SWITCH AROUND TO A MORE
WEST-NORTHWEST DIRECTION.
.OUTLOOK...
SAT/SAT NGT...MVFR-IFR FROM LAKE -SHSN IN CENTRAL NY.
SUN...A COLD FRONT WITH POSSIBLE MVFR AND IFR SNOW
SUN NGT-MON...MORE MVFR/IFR LAKE -SHSN MAINLY CENTRAL NY.
TUE...MVFR/IFR IN LIGHT SNOW AT ALL TERMINALS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ038>040-043-
044-047-048-072.
NY...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ023>025-044-
045-055-056-062.
HIGH WIND WARNING UNTIL 7 PM EST THIS EVENING FOR NYZ009-
015>018-022-036-037-046-057.
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST FRIDAY FOR NYZ009.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST FRIDAY FOR NYZ022.
LAKE EFFECT SNOW ADVISORY FROM 4 AM TO 7 PM EST FRIDAY FOR
NYZ018-036-037.
&&
$$
SYNOPSIS...
NEAR TERM...MLJ
SHORT TERM...
LONG TERM...PVN
AVIATION...PVN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
123 PM EST THU JAN 31 2013
.SYNOPSIS...
COLDER AIR WORKING INTO THE AREA BEHIND A STRONG COLD FRONT WILL
PRODUCE STRONG GUSTY WINDS TODAY...IN ADDITION TO LAKE EFFECT
SNOWS DOWNWIND OF LAKES ERIE AND ONTARIO. BELOW NORMAL
TEMPERATURES AND SCATTERED SHOW SHOWERS WILL CONTINUE INTO THE
WEEKEND...DUE TO A COMBINATION OF LAKE EFFECT SNOW SHOWERS AND
WEAK UPPER LEVEL DISTURBANCES.
&&
.NEAR TERM /THROUGH TONIGHT/...
12 NOON UPDATE... WE`VE PUSHED BACK THE START TIME OF THE LES WRNG
BY A FEW HRS IN NRN ONEIDA (NOW 21Z). BASED ON THE LATEST KBUF VWP
(STILL A 260 FLOW OVER A DEEP LYR)...AND OVERALL RADAR
PRESENTATION...WE THINK THE ONSET OF THE +SN IN NRN ONEIDA WILL BE
SOMEWHAT DELAYED FROM OUR EARLIER FCST. THE AMTS STILL LOOK
REPRESENTATIVE...AS PARAMETERS SEEM FAVORABLE FOR FAIRLY INTENSE
RATES...ONCE THE SNOW DOES FINALLY MOVE IN.
10 AM UPDATE... OUR CURRENT FCST IS IN EXCELLENT SHAPE ATTM...SO
ONLY COSMETIC CHGS WERE MADE.
AS STG CAA CONTS TO FILTER ACRS THE FA LATE THIS MRNG...LES BANDS
ARE TRYING TO ORGANIZE OFF BOTH LKS ERIE AND ONT. AS JUDGED FROM
THE 12Z RAOBS AT BUF/DTX...THE MIXED LYR EXTENDS UP TO ABT 750
MB...WITH A FAIR MOISTURE SUPPLY UNDERNEATH THE BASE OF THE
INVERSION. GIVEN CONTD CYCLONIC FLOW...FURTHER COOLING WITH
TIME...AND IF ANYTHING...A DEEPENING OF THE SYNOPTIC MOISTURE THIS
AFTN AND EVE...THERE`S NO REASON NOT TO EXPECT THE DVLPMT OF
FAIRLY STG LAKE-EFFECT PLUMES OFF BOTH LKS.
IN-HOUSE CAPE/SHEAR NOMOGRAM SHOWS ENUF OVER-LAND INSTAB THROUGH
THIS EVE (00-03Z)...SO THAT THE BANDS MAY TAKE ON SOMEWHAT OF A CELLULAR
APPEARANCE...AT TIMES. HOWEVER...ORGANIZATION IS NOT LIKELY TO BE
SERIOUSLY COMPROMISED. ALSO...THE CSTAR-DERIVED INLAND EXTENT
APPLICATION DEPICTS A FAIRLY DEEP INLAND PENETRATION THROUGHOUT
THE EVE HRS...AT LEAST...WITH A GOOD UPSTREAM CONNECTION TO
HURON/NRN LK MI/SUPERIOR...AND ALSO STG 0-1 KM SPEED SHEAR. THIS
ALSO SEEMS WELL SUPPORTED BY SIM REFLECTIVITY PRESENTATIONS FROM
THE NAM12...LOCAL ARW...AND HRRR MODELS.
BOTTOM LN...THINGS APPEAR WELL ON TRACK FOR THE LES WRNG IN NRN
ONEIDA...WITH A PD OF VERY HVY SNOW ANTICIPATED...FROM ROUGHLY
22-06Z. GIVEN DEEP MOISTURE...AND EXCELLENT CRYSTAL GROWTH
PARAMETERS...2-3"/HR RATES ARE NOT OUT OF THE QUESTION. ELSEWHERE
(ONONDAGA/MADISON/SRN ONEIDA)...DESPITE SOME ANTICIPATED
WEAKENING LTR TNT...AS THE BAND DROPS SWD...THERE MAY BE ENUF
RESIDUAL INTENSITY FOR ADVSY-LVL ACCUMS. WE`LL RE-VISIT THIS SITN
EARLY THIS AFTN.
ACRS THE TWIN TIERS...SOME CONVECTIVE SHSN ARE LIKELY TO FORM BY
MID TO LATE AFTN...AIDED A BIT BY ADVECTION OF MOISTURE FROM LKS
ERIE AND SRN MI IN STG WRLY FLOW. OVERALL...THOUGH...THE NATURE OF
THEM WILL REMAIN SCTD.
AS FOR THE WINDS...THEY`RE LIKELY TO BE AT THEIR PEAK THROUGH ABT
18Z...WITH A SLOW DIMINISHING TREND THEREAFTER...AS JUDGED FROM
ISALLOBARIC AND MOMENTUM TRANSFER PROGS.
A STEADY OR SLOWLY FALLING TEMP TREND IS WELL HANDLED IN THE
GRIDS...SO ONLY VERY MINOR TWEAKS WERE NEEDED.
PREV DISC... 620 AM...WILL DROP THE FLOOD WATCH FOR ERN ZONES AS
STEADY RAIN IS MOVG OUT. OTRW JUST MINOR NEAR TERM TWEEKS WITH NO
SIG CHGS TO FCST. PREV BLO...
450 AM...DROPPED FLOOD WATCH FOR THE CNTRL SRN TIER AND PORTIONS
OF THE FINGER LAKES AS BACK EDGE OF STEADIER RAIN HAS EXITED THIS
RGN. MAY STILL SEE SOME MINOR FLOODING DUE TO RUNOFF BUT FLS`S
HANDLING THAT. CONVECTIVE FNTL LINE PRODUCED WIND GUSTS IN THE
40-50 MPH RECENTLY AT SYR/BGM. SYNOPTIC SCALE WINDS WILL BE
INCRSNG RAPIDLY LATER THIS MRNG ALL AREAS. PREV BLO...
BACK EDGE OF AREA OF STEADY RAIN AREA MOVING INTO WRN ZONES AS OF
315 AM...CLOSE TO THE PSN OF THE SFC CDFNT...AND WILL CONTINUE IT`S EWD
PROGRESS THROUGH THE EARLY MRNG HRS. SOME OF THE RAIN MAY MIX
BRIEFLY WITH SNOW BEFORE TAPERING OFF THIS MRNG. FLOOD WATCH
REMAINS ON EFFECT...WE HAVE ISSUED SOME FLS`S THUS FAR AND WILL
CONTINUE TO MONITOR CAREFULLY.
MAIN ISSUE TDA WILL BE THE STRONG WINDS DVLPNG THIS MRNG AND
CONTINUING INTO THE AFTN HRS. BASED ON OUR SUSTAINED AND PEAK WIND
GRIDS...WE ADDED STEUBEN...YATES AND SENECA COUNTIES INTO THE
WARNING.
SCATTERED SNOW SHOWERS ARE XPCTD TDA...MAINLY DUE TO LAKE
INFLUENCES. WE COULD SEE -SHSN OFF LAKE ERIE ACRS PORTIONS OF THE
TWIN TIERS THIS AFTN/EVNG. POTNL FOR 2-4 INCHES ACRS PORTIONS OF
WRN STEUBEN TNGT. AFTN SHIFT CAN RE-ASSESS AND DETERMINE IF A LOW
END ADVISORY IS NEEDED HERE.
AS FOR THE NRN ONEIDA LES EVENT...THIS EVENT APPEARS TO BE SIMILAR
TO LAST WEEKS. THE ARW PERFORMED WELL IN THAT CASE...AND THIS
MRNG`S RUC ALSO SHOWS GOOD AGREEMENT EARLY ON IN THE PD. IT
APPEARS THAT THE BAND WILL NOT MAKE A MOVE INTO NRN ONEIDA UNTIL
LATE THIS AFTN...PERSISTING OVER THAT AREA TIL ARND 06Z BEFORE
DROPPING SWD AS FLOW BCMS MORE WNWLY. AS THIS OCCURS...MESO MDLS
SHOW THE BAND OVER LAKE ONTARIO DROPPING TO A PSN NEAR/ALONG THE
SRN SHORE OF LAKE ONTARIO LATE TNGT/TWDS DAYBREAK. THIS IS WHAT
OCCURRED WITH THE LAST BAND...AND RESULTED IN RAPID WEAKENING OF
THE BAND OVER THE BGM CWA DUE (AT LEAST IN PART) TO THE LOSS OF
OVER-LAKE TRAJECTORY. THIS IS ALSO HINTED AT IN THE MESO MDLS FRI
MRNG. FOR NOW WE HAVE THE BAND DROPPING SWD INTO ONON/MAD IN THE
09-12Z TIME FRAME...WITH POTNL FOR LOW END ADVISORY ACCUMS MAINLY
OVER NW ONON. GIVEN THE NUMEROUS HEADLINES ALREADY IN EFFECT AND
THE FACT WE HAVE SOME TIME TO TAKE A CLOSER LOOK AT THIS...WE WILL
JUST MENTION THE POTNL IN THE HWO AND LET THE DAY SHIFT ISSUE
HEADLINES FOR THIS EVENT IF NEEDED.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
A COUPLE OF CLIPPER-TYPE SYSTEMS WILL AFFECT THIS WEEKEND...WITH
SCATTERED SNOW SHOWERS. A MORE WDSPRD AREA OF LGT SNOW COULD DVLP
IN THE WARM ADVECTION PTRN AHEAD OF THE CLIPPER APRCHNG SAT NGT.
IN GNRL...CHC POPS FOR -SHSN AND BLO NORMAL TEMPS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
GRIDS WERE ADJUSTED SOME TO ACCOUNT FOR LATEST HPC GUIDANCE AND
GFS/ECMWF MODELS. NO BIG CHANGE TO GOING FORECAST OVERALL...BUT I
DID UPGRADE POPS INTO LIKELY CATEGORY FOR CENTRAL NY AND AT LEAST
HIGHER CHANCE FOR NORTHEAST PA SUNDAY WITH FAIR AGREEMENT ON BEING
INVOLVED IN MERGER BETWEEN DEVELOPING COASTAL LOW AND INCOMING
NORTHERN STREAM SYSTEM/CLIPPER. COULD EASILY RESULT IN LIGHT
COATING OF SNOW. ANOTHER WEAK CLIPPER CONTINUES TO LOOK POSSIBLE
MONDAY NIGHT/TUESDAY.
PREVIOUS DISCUSSION...
FOLLOWED HPC GUIDANCE. MODELS ARE SIMILAR WITH NO LARGE STORMS.
REMAIN UNDER A NORTHEAST US UPPER LEVEL TROF. SEASONABLE WEATHER
WITH WEAK LOW PRESSURE SYSTEMS FOLLOWED BY LAKE EFFECT. ALL PRECIP
WILL BE SNOW WITH HIGHS AROUND 30 AND LOWS IN THE TEENS. THE WEAK
SYSTEMS GO THROUGH SUNDAY AND MONDAY NIGHT...WITH LAKE EFFECT ON
THE OTHER DAYS. COULD BE A 12 HOUR DRY BREAK BETWEEN SYSTEMS WITH
WEAK HIGH PRESSURE MON AFTN.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
18Z UPDATE...
SNOW HAS MOVED INTO ALL TERMINALS BEHIND COLD FRONT. WITH
SCATTERED SNOW SHOWERS, CONDS WILL RANGE FROM VFR TO MVFR THOUGH
AN OCCASIONAL IFR CANNOT BE RULED OUT. AS LAKE EFFECT BAND GETS
ORGANIZED IFR VSBYS WILL MOVE INTO KRME AFTER 03Z AND KSYR AFTER
09Z. AT KELM AND KITH EXPECT MVFR CONDS TONIGHT WITH FLOW OFF OF
LAKE ERIE THOUGH KBGM AND KAVP SHOULD REMAIN LOW VFR.
WINDS OUT OF THE SOUTHWEST THIS AFTERNOON AROUND 25KTS WILL GUST
TO 30-40KTS. WINDS WILL REMAIN GUSTY NEXT 24 HOURS THOUGH GUSTS
WILL LESSEN TO AROUND 25KTS AND GRADUALLY SWITCH AROUND TO A MORE
WEST-NORTHWEST DIRECTION.
.OUTLOOK...
SAT/SAT NGT...MVFR-IFR FROM LAKE -SHSN IN CENTRAL NY.
SUN...A COLD FRONT WITH POSSIBLE MVFR AND IFR SNOW
SUN NGT-MON...MORE MVFR/IFR LAKE -SHSN MAINLY CENTRAL NY.
TUE...MVFR/IFR IN LIGHT SNOW AT ALL TERMINALS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ038>040-043-
044-047-048-072.
NY...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ023>025-044-
045-055-056-062.
HIGH WIND WARNING UNTIL 7 PM EST THIS EVENING FOR NYZ009-
015>018-022-036-037-046-057.
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST FRIDAY FOR NYZ009.
&&
$$
SYNOPSIS...
NEAR TERM...MLJ
SHORT TERM...
LONG TERM...MDP/TAC
AVIATION...PVN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1150 AM EST THU JAN 31 2013
.SYNOPSIS...
COLDER AIR WORKING INTO THE AREA BEHIND A STRONG COLD FRONT WILL
PRODUCE STRONG GUSTY WINDS TODAY...IN ADDITION TO LAKE EFFECT
SNOWS DOWNWIND OF LAKES ERIE AND ONTARIO. BELOW NORMAL
TEMPERATURES AND SCATTERED SHOW SHOWERS WILL CONTINUE INTO THE
WEEKEND...DUE TO A COMBINATION OF LAKE EFFECT SNOW SHOWERS AND
WEAK UPPER LEVEL DISTURBANCES.
&&
.NEAR TERM /THROUGH TONIGHT/...
12 NOON UPDATE... WE`VE PUSHED BACK THE START TIME OF THE LES WRNG
BY A FEW HRS IN NRN ONEIDA (NOW 21Z). BASED ON THE LATEST KBUF VWP
(STILL A 260 FLOW OVER A DEEP LYR)...AND OVERALL RADAR
PRESENTATION...WE THINK THE ONSET OF THE +SN IN NRN ONEIDA WILL BE
SOMEWHAT DELAYED FROM OUR EARLIER FCST. THE AMTS STILL LOOK
REPRESENTATIVE...AS PARAMETERS SEEM FAVORABLE FOR FAIRLY INTENSE
RATES...ONCE THE SNOW DOES FINALLY MOVE IN.
10 AM UPDATE... OUR CURRENT FCST IS IN EXCELLENT SHAPE ATTM...SO
ONLY COSMETIC CHGS WERE MADE.
AS STG CAA CONTS TO FILTER ACRS THE FA LATE THIS MRNG...LES BANDS
ARE TRYING TO ORGANIZE OFF BOTH LKS ERIE AND ONT. AS JUDGED FROM
THE 12Z RAOBS AT BUF/DTX...THE MIXED LYR EXTENDS UP TO ABT 750
MB...WITH A FAIR MOISTURE SUPPLY UNDERNEATH THE BASE OF THE
INVERSION. GIVEN CONTD CYCLONIC FLOW...FURTHER COOLING WITH
TIME...AND IF ANYTHING...A DEEPENING OF THE SYNOPTIC MOISTURE THIS
AFTN AND EVE...THERE`S NO REASON NOT TO EXPECT THE DVLPMT OF
FAIRLY STG LAKE-EFFECT PLUMES OFF BOTH LKS.
IN-HOUSE CAPE/SHEAR NOMOGRAM SHOWS ENUF OVER-LAND INSTAB THROUGH
THIS EVE (00-03Z)...SO THAT THE BANDS MAY TAKE ON SOMEWHAT OF A CELLULAR
APPEARANCE...AT TIMES. HOWEVER...ORGANIZATION IS NOT LIKELY TO BE
SERIOUSLY COMPROMISED. ALSO...THE CSTAR-DERIVED INLAND EXTENT
APPLICATION DEPICTS A FAIRLY DEEP INLAND PENETRATION THROUGHOUT
THE EVE HRS...AT LEAST...WITH A GOOD UPSTREAM CONNECTION TO
HURON/NRN LK MI/SUPERIOR...AND ALSO STG 0-1 KM SPEED SHEAR. THIS
ALSO SEEMS WELL SUPPORTED BY SIM REFLECTIVITY PRESENTATIONS FROM
THE NAM12...LOCAL ARW...AND HRRR MODELS.
BOTTOM LN...THINGS APPEAR WELL ON TRACK FOR THE LES WRNG IN NRN
ONEIDA...WITH A PD OF VERY HVY SNOW ANTICIPATED...FROM ROUGHLY
22-06Z. GIVEN DEEP MOISTURE...AND EXCELLENT CRYSTAL GROWTH
PARAMETERS...2-3"/HR RATES ARE NOT OUT OF THE QUESTION. ELSEWHERE
(ONONDAGA/MADISON/SRN ONEIDA)...DESPITE SOME ANTICIPATED
WEAKENING LTR TNT...AS THE BAND DROPS SWD...THERE MAY BE ENUF
RESIDUAL INTENSITY FOR ADVSY-LVL ACCUMS. WE`LL RE-VISIT THIS SITN
EARLY THIS AFTN.
ACRS THE TWIN TIERS...SOME CONVECTIVE SHSN ARE LIKELY TO FORM BY
MID TO LATE AFTN...AIDED A BIT BY ADVECTION OF MOISTURE FROM LKS
ERIE AND SRN MI IN STG WRLY FLOW. OVERALL...THOUGH...THE NATURE OF
THEM WILL REMAIN SCTD.
AS FOR THE WINDS...THEY`RE LIKELY TO BE AT THEIR PEAK THROUGH ABT
18Z...WITH A SLOW DIMINISHING TREND THEREAFTER...AS JUDGED FROM
ISALLOBARIC AND MOMENTUM TRANSFER PROGS.
A STEADY OR SLOWLY FALLING TEMP TREND IS WELL HANDLED IN THE
GRIDS...SO ONLY VERY MINOR TWEAKS WERE NEEDED.
PREV DISC... 620 AM...WILL DROP THE FLOOD WATCH FOR ERN ZONES AS
STEADY RAIN IS MOVG OUT. OTRW JUST MINOR NEAR TERM TWEEKS WITH NO
SIG CHGS TO FCST. PREV BLO...
450 AM...DROPPED FLOOD WATCH FOR THE CNTRL SRN TIER AND PORTIONS
OF THE FINGER LAKES AS BACK EDGE OF STEADIER RAIN HAS EXITED THIS
RGN. MAY STILL SEE SOME MINOR FLOODING DUE TO RUNOFF BUT FLS`S
HANDLING THAT. CONVECTIVE FNTL LINE PRODUCED WIND GUSTS IN THE
40-50 MPH RECENTLY AT SYR/BGM. SYNOPTIC SCALE WINDS WILL BE
INCRSNG RAPIDLY LATER THIS MRNG ALL AREAS. PREV BLO...
BACK EDGE OF AREA OF STEADY RAIN AREA MOVING INTO WRN ZONES AS OF
315 AM...CLOSE TO THE PSN OF THE SFC CDFNT...AND WILL CONTINUE IT`S EWD
PROGRESS THROUGH THE EARLY MRNG HRS. SOME OF THE RAIN MAY MIX
BRIEFLY WITH SNOW BEFORE TAPERING OFF THIS MRNG. FLOOD WATCH
REMAINS ON EFFECT...WE HAVE ISSUED SOME FLS`S THUS FAR AND WILL
CONTINUE TO MONITOR CAREFULLY.
MAIN ISSUE TDA WILL BE THE STRONG WINDS DVLPNG THIS MRNG AND
CONTINUING INTO THE AFTN HRS. BASED ON OUR SUSTAINED AND PEAK WIND
GRIDS...WE ADDED STEUBEN...YATES AND SENECA COUNTIES INTO THE
WARNING.
SCATTERED SNOW SHOWERS ARE XPCTD TDA...MAINLY DUE TO LAKE
INFLUENCES. WE COULD SEE -SHSN OFF LAKE ERIE ACRS PORTIONS OF THE
TWIN TIERS THIS AFTN/EVNG. POTNL FOR 2-4 INCHES ACRS PORTIONS OF
WRN STEUBEN TNGT. AFTN SHIFT CAN RE-ASSESS AND DETERMINE IF A LOW
END ADVISORY IS NEEDED HERE.
AS FOR THE NRN ONEIDA LES EVENT...THIS EVENT APPEARS TO BE SIMILAR
TO LAST WEEKS. THE ARW PERFORMED WELL IN THAT CASE...AND THIS
MRNG`S RUC ALSO SHOWS GOOD AGREEMENT EARLY ON IN THE PD. IT
APPEARS THAT THE BAND WILL NOT MAKE A MOVE INTO NRN ONEIDA UNTIL
LATE THIS AFTN...PERSISTING OVER THAT AREA TIL ARND 06Z BEFORE
DROPPING SWD AS FLOW BCMS MORE WNWLY. AS THIS OCCURS...MESO MDLS
SHOW THE BAND OVER LAKE ONTARIO DROPPING TO A PSN NEAR/ALONG THE
SRN SHORE OF LAKE ONTARIO LATE TNGT/TWDS DAYBREAK. THIS IS WHAT
OCCURRED WITH THE LAST BAND...AND RESULTED IN RAPID WEAKENING OF
THE BAND OVER THE BGM CWA DUE (AT LEAST IN PART) TO THE LOSS OF
OVER-LAKE TRAJECTORY. THIS IS ALSO HINTED AT IN THE MESO MDLS FRI
MRNG. FOR NOW WE HAVE THE BAND DROPPING SWD INTO ONON/MAD IN THE
09-12Z TIME FRAME...WITH POTNL FOR LOW END ADVISORY ACCUMS MAINLY
OVER NW ONON. GIVEN THE NUMEROUS HEADLINES ALREADY IN EFFECT AND
THE FACT WE HAVE SOME TIME TO TAKE A CLOSER LOOK AT THIS...WE WILL
JUST MENTION THE POTNL IN THE HWO AND LET THE DAY SHIFT ISSUE
HEADLINES FOR THIS EVENT IF NEEDED.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
A COUPLE OF CLIPPER-TYPE SYSTEMS WILL AFFECT THIS WEEKEND...WITH
SCATTERED SNOW SHOWERS. A MORE WDSPRD AREA OF LGT SNOW COULD DVLP
IN THE WARM ADVECTION PTRN AHEAD OF THE CLIPPER APRCHNG SAT NGT.
IN GNRL...CHC POPS FOR -SHSN AND BLO NORMAL TEMPS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
GRIDS WERE ADJUSTED SOME TO ACCOUNT FOR LATEST HPC GUIDANCE AND
GFS/ECMWF MODELS. NO BIG CHANGE TO GOING FORECAST OVERALL...BUT I
DID UPGRADE POPS INTO LIKELY CATEGORY FOR CENTRAL NY AND AT LEAST
HIGHER CHANCE FOR NORTHEAST PA SUNDAY WITH FAIR AGREEMENT ON BEING
INVOLVED IN MERGER BETWEEN DEVELOPING COASTAL LOW AND INCOMING
NORTHERN STREAM SYSTEM/CLIPPER. COULD EASILY RESULT IN LIGHT
COATING OF SNOW. ANOTHER WEAK CLIPPER CONTINUES TO LOOK POSSIBLE
MONDAY NIGHT/TUESDAY.
PREVIOUS DISCUSSION...
FOLLOWED HPC GUIDANCE. MODELS ARE SIMILAR WITH NO LARGE STORMS.
REMAIN UNDER A NORTHEAST US UPPER LEVEL TROF. SEASONABLE WEATHER
WITH WEAK LOW PRESSURE SYSTEMS FOLLOWED BY LAKE EFFECT. ALL PRECIP
WILL BE SNOW WITH HIGHS AROUND 30 AND LOWS IN THE TEENS. THE WEAK
SYSTEMS GO THROUGH SUNDAY AND MONDAY NIGHT...WITH LAKE EFFECT ON
THE OTHER DAYS. COULD BE A 12 HOUR DRY BREAK BETWEEN SYSTEMS WITH
WEAK HIGH PRESSURE MON AFTN.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
12Z UPDATE...
STRONG COLD FRONT IS JUST FINISHING ITS BLAST THROUGH THE
AREA...TAKING THE STEADIER RAIN SHOWERS WITH IT. WINDS WILL HAVE A
MUCH EASIER TIME MIXING DOWN IN THE COLD AIR BEHIND THE
FRONT...ALLOWING WESTERLY GUSTS FREQUENTLY IN THE 30-40 KT RANGE.
GUSTS AT KSYR AND PERHAPS KRME WILL EVEN TOP OUT AROUND 35-45 KTS
AT TIMES TODAY. EXPECTING SCT-BKN CLOUD DECK WITH SCT -SHSN AND
MVFR CIG FOR SOME TERMINALS. THOUGH GENERALLY VFR TO MVFR IN TAFS
TODAY WITH THE SNOW FLURRIES...SOME TERMINALS WILL HAVE TO WATCH
FOR BRIEF SURPRISE IFR VIS FROM A HEAVIER LAKE EFFECT SNOW SHOWER.
THE MAIN LAKE ONTARIO SNOW BAND WILL AT FIRST DEVELOP NORTH OF THE
AREA THIS AFTERNOON...BUT SHOULD EDGE SOUTH ENOUGH TO INVOLVE KRME
IN OCCASIONAL IFR VIS AFTER 03Z...AND BY 09Z ONWARD FOR KSYR.
.OUTLOOK...
FRI THRU SAT NGT...MVFR-IFR FROM LAKE -SHSN IN CENTRAL NY.
SUN...A COLD FRONT WITH POSSIBLE MVFR AND IFR SNOW
SUN NGT-MON...MORE MVFR/IFR LAKE -SHSN MAINLY CENTRAL NY.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ038>040-043-
044-047-048-072.
NY...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ023>025-044-
045-055-056-062.
HIGH WIND WARNING UNTIL 7 PM EST THIS EVENING FOR NYZ009-
015>018-022-036-037-046-057.
LAKE EFFECT SNOW WARNING FROM 4 PM THIS AFTERNOON TO 7 AM EST
FRIDAY FOR NYZ009.
&&
$$
SYNOPSIS...
NEAR TERM...MLJ
SHORT TERM...
LONG TERM...MDP/TAC
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1023 AM EST THU JAN 31 2013
.SYNOPSIS...
COLDER AIR WORKING INTO THE AREA BEHIND A STRONG COLD FRONT WILL
PRODUCE STRONG GUSTY WINDS TODAY...IN ADDITION TO LAKE EFFECT
SNOWS DOWNWIND OF LAKES ERIE AND ONTARIO. BELOW NORMAL
TEMPERATURES AND SCATTERED SHOW SHOWERS WILL CONTINUE INTO THE
WEEKEND...DUE TO A COMBINATION OF LAKE EFFECT SNOW SHOWERS AND
WEAK UPPER LEVEL DISTURBANCES.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE... OUR CURRENT FCST IS IN EXCELLENT SHAPE ATTM...SO
ONLY COSMETIC CHGS WERE MADE.
AS STG CAA CONTS TO FILTER ACRS THE FA LATE THIS MRNG...LES BANDS
ARE TRYING TO ORGANIZE OFF BOTH LKS ERIE AND ONT. AS JUDGED FROM
THE 12Z RAOBS AT BUF/DTX...THE MIXED LYR EXTENDS UP TO ABT 750
MB...WITH A FAIR MOISTURE SUPPLY UNDERNEATH THE BASE OF THE
INVERSION. GIVEN CONTD CYCLONIC FLOW...FURTHER COOLING WITH
TIME...AND IF ANYTHING...A DEEPENING OF THE SYNOPTIC MOISTURE THIS
AFTN AND EVE...THERE`S NO REASON NOT TO EXPECT THE DVLPMT OF
FAIRLY STG LAKE-EFFECT PLUMES OFF BOTH LKS.
IN-HOUSE CAPE/SHEAR NOMOGRAM SHOWS ENUF OVER-LAND INSTAB THROUGH
THIS EVE (00-03Z)...SO THAT THE BANDS MAY TAKE ON SOMEWHAT OF A CELLULAR
APPEARANCE...AT TIMES. HOWEVER...ORGANIZATION IS NOT LIKELY TO BE
SERIOUSLY COMPROMISED. ALSO...THE CSTAR-DERIVED INLAND EXTENT
APPLICATION DEPICTS A FAIRLY DEEP INLAND PENETRATION THROUGHOUT
THE EVE HRS...AT LEAST...WITH A GOOD UPSTREAM CONNECTION TO
HURON/NRN LK MI/SUPERIOR...AND ALSO STG 0-1 KM SPEED SHEAR. THIS
ALSO SEEMS WELL SUPPORTED BY SIM REFLECTIVITY PRESENTATIONS FROM
THE NAM12...LOCAL ARW...AND HRRR MODELS.
BOTTOM LN...THINGS APPEAR WELL ON TRACK FOR THE LES WRNG IN NRN
ONEIDA...WITH A PD OF VERY HVY SNOW ANTICIPATED...FROM ROUGHLY
22-06Z. GIVEN DEEP MOISTURE...AND EXCELLENT CRYSTAL GROWTH
PARAMETERS...2-3"/HR RATES ARE NOT OUT OF THE QUESTION. ELSEWHERE
(ONONDAGA/MADISON/SRN ONEIDA)...DESPITE SOME ANTICIPATED
WEAKENING LTR TNT...AS THE BAND DROPS SWD...THERE MAY BE ENUF
RESIDUAL INTENSITY FOR ADVSY-LVL ACCUMS. WE`LL RE-VISIT THIS SITN
EARLY THIS AFTN.
ACRS THE TWIN TIERS...SOME CONVECTIVE SHSN ARE LIKELY TO FORM BY
MID TO LATE AFTN...AIDED A BIT BY ADVECTION OF MOISTURE FROM LKS
ERIE AND SRN MI IN STG WRLY FLOW. OVERALL...THOUGH...THE NATURE OF
THEM WILL REMAIN SCTD.
AS FOR THE WINDS...THEY`RE LIKELY TO BE AT THEIR PEAK THROUGH ABT
18Z...WITH A SLOW DIMINISHING TREND THEREAFTER...AS JUDGED FROM
ISALLOBARIC AND MOMENTUM TRANSFER PROGS.
A STEADY OR SLOWLY FALLING TEMP TREND IS WELL HANDLED IN THE
GRIDS...SO ONLY VERY MINOR TWEAKS WERE NEEDED.
PREV DISC... 620 AM...WILL DROP THE FLOOD WATCH FOR ERN ZONES AS
STEADY RAIN IS MOVG OUT. OTRW JUST MINOR NEAR TERM TWEEKS WITH NO
SIG CHGS TO FCST. PREV BLO...
450 AM...DROPPED FLOOD WATCH FOR THE CNTRL SRN TIER AND PORTIONS
OF THE FINGER LAKES AS BACK EDGE OF STEADIER RAIN HAS EXITED THIS
RGN. MAY STILL SEE SOME MINOR FLOODING DUE TO RUNOFF BUT FLS`S
HANDLING THAT. CONVECTIVE FNTL LINE PRODUCED WIND GUSTS IN THE
40-50 MPH RECENTLY AT SYR/BGM. SYNOPTIC SCALE WINDS WILL BE
INCRSNG RAPIDLY LATER THIS MRNG ALL AREAS. PREV BLO...
BACK EDGE OF AREA OF STEADY RAIN AREA MOVING INTO WRN ZONES AS OF
315 AM...CLOSE TO THE PSN OF THE SFC CDFNT...AND WILL CONTINUE IT`S EWD
PROGRESS THROUGH THE EARLY MRNG HRS. SOME OF THE RAIN MAY MIX
BRIEFLY WITH SNOW BEFORE TAPERING OFF THIS MRNG. FLOOD WATCH
REMAINS ON EFFECT...WE HAVE ISSUED SOME FLS`S THUS FAR AND WILL
CONTINUE TO MONITOR CAREFULLY.
MAIN ISSUE TDA WILL BE THE STRONG WINDS DVLPNG THIS MRNG AND
CONTINUING INTO THE AFTN HRS. BASED ON OUR SUSTAINED AND PEAK WIND
GRIDS...WE ADDED STEUBEN...YATES AND SENECA COUNTIES INTO THE
WARNING.
SCATTERED SNOW SHOWERS ARE XPCTD TDA...MAINLY DUE TO LAKE
INFLUENCES. WE COULD SEE -SHSN OFF LAKE ERIE ACRS PORTIONS OF THE
TWIN TIERS THIS AFTN/EVNG. POTNL FOR 2-4 INCHES ACRS PORTIONS OF
WRN STEUBEN TNGT. AFTN SHIFT CAN RE-ASSESS AND DETERMINE IF A LOW
END ADVISORY IS NEEDED HERE.
AS FOR THE NRN ONEIDA LES EVENT...THIS EVENT APPEARS TO BE SIMILAR
TO LAST WEEKS. THE ARW PERFORMED WELL IN THAT CASE...AND THIS
MRNG`S RUC ALSO SHOWS GOOD AGREEMENT EARLY ON IN THE PD. IT
APPEARS THAT THE BAND WILL NOT MAKE A MOVE INTO NRN ONEIDA UNTIL
LATE THIS AFTN...PERSISTING OVER THAT AREA TIL ARND 06Z BEFORE
DROPPING SWD AS FLOW BCMS MORE WNWLY. AS THIS OCCURS...MESO MDLS
SHOW THE BAND OVER LAKE ONTARIO DROPPING TO A PSN NEAR/ALONG THE
SRN SHORE OF LAKE ONTARIO LATE TNGT/TWDS DAYBREAK. THIS IS WHAT
OCCURRED WITH THE LAST BAND...AND RESULTED IN RAPID WEAKENING OF
THE BAND OVER THE BGM CWA DUE (AT LEAST IN PART) TO THE LOSS OF
OVER-LAKE TRAJECTORY. THIS IS ALSO HINTED AT IN THE MESO MDLS FRI
MRNG. FOR NOW WE HAVE THE BAND DROPPING SWD INTO ONON/MAD IN THE
09-12Z TIME FRAME...WITH POTNL FOR LOW END ADVISORY ACCUMS MAINLY
OVER NW ONON. GIVEN THE NUMEROUS HEADLINES ALREADY IN EFFECT AND
THE FACT WE HAVE SOME TIME TO TAKE A CLOSER LOOK AT THIS...WE WILL
JUST MENTION THE POTNL IN THE HWO AND LET THE DAY SHIFT ISSUE
HEADLINES FOR THIS EVENT IF NEEDED.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
A COUPLE OF CLIPPER-TYPE SYSTEMS WILL AFFECT THIS WEEKEND...WITH
SCATTERED SNOW SHOWERS. A MORE WDSPRD AREA OF LGT SNOW COULD DVLP
IN THE WARM ADVECTION PTRN AHEAD OF THE CLIPPER APRCHNG SAT NGT.
IN GNRL...CHC POPS FOR -SHSN AND BLO NORMAL TEMPS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
GRIDS WERE ADJUSTED SOME TO ACCOUNT FOR LATEST HPC GUIDANCE AND
GFS/ECMWF MODELS. NO BIG CHANGE TO GOING FORECAST OVERALL...BUT I
DID UPGRADE POPS INTO LIKELY CATEGORY FOR CENTRAL NY AND AT LEAST
HIGHER CHANCE FOR NORTHEAST PA SUNDAY WITH FAIR AGREEMENT ON BEING
INVOLVED IN MERGER BETWEEN DEVELOPING COASTAL LOW AND INCOMING
NORTHERN STREAM SYSTEM/CLIPPER. COULD EASILY RESULT IN LIGHT
COATING OF SNOW. ANOTHER WEAK CLIPPER CONTINUES TO LOOK POSSIBLE
MONDAY NIGHT/TUESDAY.
PREVIOUS DISCUSSION...
FOLLOWED HPC GUIDANCE. MODELS ARE SIMILAR WITH NO LARGE STORMS.
REMAIN UNDER A NORTHEAST US UPPER LEVEL TROF. SEASONABLE WEATHER
WITH WEAK LOW PRESSURE SYSTEMS FOLLOWED BY LAKE EFFECT. ALL PRECIP
WILL BE SNOW WITH HIGHS AROUND 30 AND LOWS IN THE TEENS. THE WEAK
SYSTEMS GO THROUGH SUNDAY AND MONDAY NIGHT...WITH LAKE EFFECT ON
THE OTHER DAYS. COULD BE A 12 HOUR DRY BREAK BETWEEN SYSTEMS WITH
WEAK HIGH PRESSURE MON AFTN.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
12Z UPDATE...
STRONG COLD FRONT IS JUST FINISHING ITS BLAST THROUGH THE
AREA...TAKING THE STEADIER RAIN SHOWERS WITH IT. WINDS WILL HAVE A
MUCH EASIER TIME MIXING DOWN IN THE COLD AIR BEHIND THE
FRONT...ALLOWING WESTERLY GUSTS FREQUENTLY IN THE 30-40 KT RANGE.
GUSTS AT KSYR AND PERHAPS KRME WILL EVEN TOP OUT AROUND 35-45 KTS
AT TIMES TODAY. EXPECTING SCT-BKN CLOUD DECK WITH SCT -SHSN AND
MVFR CIG FOR SOME TERMINALS. THOUGH GENERALLY VFR TO MVFR IN TAFS
TODAY WITH THE SNOW FLURRIES...SOME TERMINALS WILL HAVE TO WATCH
FOR BRIEF SURPRISE IFR VIS FROM A HEAVIER LAKE EFFECT SNOW SHOWER.
THE MAIN LAKE ONTARIO SNOW BAND WILL AT FIRST DEVELOP NORTH OF THE
AREA THIS AFTERNOON...BUT SHOULD EDGE SOUTH ENOUGH TO INVOLVE KRME
IN OCCASIONAL IFR VIS AFTER 03Z...AND BY 09Z ONWARD FOR KSYR.
.OUTLOOK...
FRI THRU SAT NGT...MVFR-IFR FROM LAKE -SHSN IN CENTRAL NY.
SUN...A COLD FRONT WITH POSSIBLE MVFR AND IFR SNOW
SUN NGT-MON...MORE MVFR/IFR LAKE -SHSN MAINLY CENTRAL NY.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ038>040-043-
044-047-048-072.
NY...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ023>025-044-
045-055-056-062.
HIGH WIND WARNING UNTIL 7 PM EST THIS EVENING FOR NYZ009-
015>018-022-036-037-046-057.
LAKE EFFECT SNOW WARNING FROM 1 PM THIS AFTERNOON TO 7 AM EST
FRIDAY FOR NYZ009.
&&
$$
SYNOPSIS...
NEAR TERM...MLJ
SHORT TERM...
LONG TERM...MDP/TAC
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
651 AM EST THU JAN 31 2013
.SYNOPSIS...
COLDER AIR WORKING INTO THE AREA BEHIND A STRONG COLD FRONT WILL
PRODUCE STRONG GUSTY WINDS TODAY...IN ADDITION TO LAKE EFFECT
SNOWS DOWNWIND OF LAKES ERIE AND ONTARIO. BELOW NORMAL
TEMPERATURES AND SCATTERED SHOW SHOWERS WILL CONTINUE INTO THE
WEEKEND...DUE TO A COMBINATION OF LAKE EFFECT SNOW SHOWERS AND
WEAK UPPER LEVEL DISTURBANCES.
&&
.NEAR TERM /THROUGH TONIGHT/...
620 AM...WILL DROP THE FLOOD WATCH FOR ERN ZONES AS STEADY RAIN IS
MOVG OUT. OTRW JUST MINOR NEAR TERM TWEEKS WITH NO SIG CHGS TO
FCST. PREV BLO...
450 AM...DROPPED FLOOD WATCH FOR THER CNTRL SRN TIER AND PORTIONS
OF THE FINGER LAKES AS BACKEDGE OF STEADIER RAIN HAS EXITED THIS
RGN. MAY STILL SEE SOME MINOR FLOODING DUE TO RUNOFF BUT FLS`S
HANDLING THAT. CONVECTIVE FNTL LINE PRODUCED WIND GUSTS IN THE
40-50 MPH RECENTLY AT SYR/BGM. SYNOPTIC SCALE WINDS WILL BE
INCRSNG RAPIDLY LATER THIS MRNG ALL AREAS. PREV BLO...
BACKEDGE OF AREA OF STEADY RAIN AREA MOVING INTO WRN ZONES AS OF
315 AM...CLOSE TO THE PSN OF THE SFC CDFNT...AND WILL CONTINUE IT`S EWD
PROGRESS THROUGH THE EARLY MRNG HRS. SOME OF THE RAIN MAY MIX
BRIEFLY WITH SNOW BEFORE TAPERING OFF THIS MRNG. FLOOD WATCH
REMAINS ON EFFECT...WE HAVE ISSUED SOME FLS`S THUS FAR AND WILL
CONTINUE TO MONITOR CAREFULLY.
MAIN ISSUE TDA WILL BE THE STRONG WINDS DVLPNG THIS MRNG AND
CONTINUING INTO THE AFTN HRS. BASED ON OUR SUSTAINED AND PEAK WIND
GRIDS...WE ADDED STEUBEN...YATES AND SENECA COUNTIES INTO THE
WARNING.
SCATTERED SNOW SHOWERS ARE XPCTD TDA...MAILY DUE TO LAKE
INFLUENCES. WE COULD SEE -SHSN OFF LAKE ERIE ACRS PORTIONS OF THE
TWIN TIERS THIS AFTN/EVNG. POTNL FOR 2-4 INCHES ACRS PORTIONS OF
WRN STEUBEN TNGT. AFTN SHIFT CAN RE-ASSESS AND DETERMINE IF A LOW
END ADVISORY IS NEEDED HERE.
AS FOR THE NRN ONEIDA LES EVENT...THIS EVENT APPEARS TO BE SIMILAR
TO LAST WEEKS. THE ARW PERFORMED WELL IN THAT CASE...AND THIS
MRNG`S RUC ALSO SHOWS GOOD AGREEMENT EARLY ON IN THE PD. IT
APPEARS THAT THE BAND WILL NOT MAKE A MOVE INTO NRN ONEIDA UNTIL
LATE THIS AFTN...PERSISTING OVER THAT AREA TIL ARND 06Z BEFORE
DROPPING SWD AS FLOW BCMS MORE WNWLY. AS THIS OCCURS...MESO MDLS
SHOW THE BAND OVER LAKE ONTARIO DROPPING TO A PSN NEAR/ALONG THE
SRN SHORE OF LAKE ONTARIO LATE TNGT/TWDS DAYBREAK. THIS IS WHAT
OCCURRED WITH THE LAST BAND...AND RESULTED IN RAPID WEAKENING OF
TEH BAND OVER THE BGM CWA DUE (AT LEAST IN PART) TO THE LOSS OF
OVER-LAKE TRAJECTORY. THIS IS ALSO HINTED AT IN THE MESO MDLS FRI
MRNG. FOR NOW WE HAVE THE BAND DROPPING SWD INTO ONON/MAD IN THE
09-12Z TIME FRAME...WITH POTNL FOR LOW END ADVISORY ACCUMS MAINLY
OVER NW ONON. GIVEN THE NUMEROUS HEADLINES ALREADY IN EFFECT AND
THE FACT WE HAVE SOME TIME TO TAKE A CLOSER LOOK AT THIS...WE WILL
JUST MENTION THE POTNL IN THE HWO AND LET THE DAYSHIFT ISSUE
HEADLINES FOR THIS EVENT IF NEEDED.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
A COUPLE OF CLIPPER-TYPE SYSTEMS WILL AFFECT THIS WEEKEND...WITH
SCATTERED SNOW SHOWERS. A MORE WDSPRD AREA OF LGT SNOW COULD DVLP
IN THE WARM ADVECTION PTRN AHEAD OF THE CLIPPER APRCHNG SAT NGT.
IN GNRL...CHC POPS FOR -SHSN AND BLO NORMAL TEMPS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
GRIDS WERE ADJUSTED SOME TO ACCOUNT FOR LATEST HPC GUIDANCE AND
GFS/ECMWF MODELS. NO BIG CHANGE TO GOING FORECAST OVERALL...BUT I
DID UPGRADE POPS INTO LIKELY CATEGORY FOR CENTRAL NY AND AT LEAST
HIGHER CHANCE FOR NORTHEAST PA SUNDAY WITH FAIR AGREEMENT ON BEING
INVOLVED IN MERGER BETWEEN DEVELOPING COASTAL LOW AND INCOMING
NORTHERN STREAM SYSTEM/CLIPPER. COULD EASILY RESULT IN LIGHT
COATING OF SNOW. ANOTHER WEAK CLIPPER CONTINUES TO LOOK POSSIBLE
MONDAY NIGHT/TUESDAY.
PREVIOUS DISCUSSION...
FOLLOWED HPC GUIDANCE. MODELS ARE SIMILAR WITH NO LARGE STORMS.
REMAIN UNDER A NORTHEAST US UPPER LEVEL TROF. SEASONABLE WEATHER
WITH WEAK LOW PRESSURE SYSTEMS FOLLOWED BY LAKE EFFECT. ALL PRECIP
WILL BE SNOW WITH HIGHS AROUND 30 AND LOWS IN THE TEENS. THE WEAK
SYSTEMS GO THROUGH SUNDAY AND MONDAY NIGHT...WITH LAKE EFFECT ON
THE OTHER DAYS. COULD BE A 12 HOUR DRY BREAK BETWEEN SYSTEMS WITH
WEAK HIGH PRESSURE MON AFTN.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
12Z UPDATE...
STRONG COLD FRONT IS JUST FINISHING ITS BLAST THROUGH THE
AREA...TAKING THE STEADIER RAIN SHOWERS WITH IT. WINDS WILL HAVE A
MUCH EASIER TIME MIXING DOWN IN THE COLD AIR BEHIND THE
FRONT...ALLOWING WESTERLY GUSTS FREQUENTLY IN THE 30-40 KT RANGE.
GUSTS AT KSYR AND PERHAPS KRME WILL EVEN TOP OUT AROUND 35-45 KTS
AT TIMES TODAY. EXPECTING SCT-BKN CLOUD DECK WITH SCT -SHSN AND
MVFR CIG FOR SOME TERMINALS. THOUGH GENERALLY VFR TO MVFR IN TAFS
TODAY WITH THE SNOW FLURRIES...SOME TERMINALS WILL HAVE TO WATCH
FOR BRIEF SURPRISE IFR VIS FROM A HEAVIER LAKE EFFECT SNOW SHOWER.
THE MAIN LAKE ONTARIO SNOW BAND WILL AT FIRST DEVELOP NORTH OF THE
AREA THIS AFTERNOON...BUT SHOULD EDGE SOUTH ENOUGH TO INVOLVE KRME
IN OCCASIONAL IFR VIS AFTER 03Z...AND BY 09Z ONWARD FOR KSYR.
.OUTLOOK...
FRI THRU SAT NGT...MVFR-IFR FROM LAKE -SHSN IN CENTRAL NY.
SUN...A COLD FRONT WITH POSSIBLE MVFR AND IFR SNOW
SUN NGT-MON...MORE MVFR/IFR LAKE -SHSN MAINLY CENTRAL NY.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ038>040-043-
044-047-048-072.
NY...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ023>025-044-
045-055-056-062.
HIGH WIND WARNING UNTIL 7 PM EST THIS EVENING FOR NYZ009-
015>018-022-036-037-046-057.
LAKE EFFECT SNOW WARNING FROM 1 PM THIS AFTERNOON TO 7 AM EST
FRIDAY FOR NYZ009.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...MDP/TAC
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
620 AM EST THU JAN 31 2013
.SYNOPSIS...
COLDER AIR WORKING INTO THE AREA BEHIND A STRONG COLD FRONT WILL
PRODUCE STRONG GUSTY WINDS TODAY...IN ADDITION TO LAKE EFFECT
SNOWS DOWNWIND OF LAKES ERIE AND ONTARIO. BELOW NORMAL
TEMPERATURES AND SCATTERED SHOW SHOWERS WILL CONTINUE INTO THE
WEEKEND...DUE TO A COMBINATION OF LAKE EFFECT SNOW SHOWERS AND
WEAK UPPER LEVEL DISTURBANCES.
&&
.NEAR TERM /THROUGH TONIGHT/...
620 AM...WILL DROP THE FLOOD WATCH FOR ERN ZONES AS STEADY RAIN IS
MOVG OUT. OTRW JUST MINOR NEAR TERM TWEEKS WITH NO SIG CHGS TO
FCST. PREV BLO...
450 AM...DROPPED FLOOD WATCH FOR THER CNTRL SRN TIER AND PORTIONS
OF THE FINGER LAKES AS BACKEDGE OF STEADIER RAIN HAS EXITED THIS
RGN. MAY STILL SEE SOME MINOR FLOODING DUE TO RUNOFF BUT FLS`S
HANDLING THAT. CONVECTIVE FNTL LINE PRODUCED WIND GUSTS IN THE
40-50 MPH RECENTLY AT SYR/BGM. SYNOPTIC SCALE WINDS WILL BE
INCRSNG RAPIDLY LATER THIS MRNG ALL AREAS. PREV BLO...
BACKEDGE OF AREA OF STEADY RAIN AREA MOVING INTO WRN ZONES AS OF
315 AM...CLOSE TO THE PSN OF THE SFC CDFNT...AND WILL CONTINUE IT`S EWD
PROGRESS THROUGH THE EARLY MRNG HRS. SOME OF THE RAIN MAY MIX
BRIEFLY WITH SNOW BEFORE TAPERING OFF THIS MRNG. FLOOD WATCH
REMAINS ON EFFECT...WE HAVE ISSUED SOME FLS`S THUS FAR AND WILL
CONTINUE TO MONITOR CAREFULLY.
MAIN ISSUE TDA WILL BE THE STRONG WINDS DVLPNG THIS MRNG AND
CONTINUING INTO THE AFTN HRS. BASED ON OUR SUSTAINED AND PEAK WIND
GRIDS...WE ADDED STEUBEN...YATES AND SENECA COUNTIES INTO THE
WARNING.
SCATTERED SNOW SHOWERS ARE XPCTD TDA...MAILY DUE TO LAKE
INFLUENCES. WE COULD SEE -SHSN OFF LAKE ERIE ACRS PORTIONS OF THE
TWIN TIERS THIS AFTN/EVNG. POTNL FOR 2-4 INCHES ACRS PORTIONS OF
WRN STEUBEN TNGT. AFTN SHIFT CAN RE-ASSESS AND DETERMINE IF A LOW
END ADVISORY IS NEEDED HERE.
AS FOR THE NRN ONEIDA LES EVENT...THIS EVENT APPEARS TO BE SIMILAR
TO LAST WEEKS. THE ARW PERFORMED WELL IN THAT CASE...AND THIS
MRNG`S RUC ALSO SHOWS GOOD AGREEMENT EARLY ON IN THE PD. IT
APPEARS THAT THE BAND WILL NOT MAKE A MOVE INTO NRN ONEIDA UNTIL
LATE THIS AFTN...PERSISTING OVER THAT AREA TIL ARND 06Z BEFORE
DROPPING SWD AS FLOW BCMS MORE WNWLY. AS THIS OCCURS...MESO MDLS
SHOW THE BAND OVER LAKE ONTARIO DROPPING TO A PSN NEAR/ALONG THE
SRN SHORE OF LAKE ONTARIO LATE TNGT/TWDS DAYBREAK. THIS IS WHAT
OCCURRED WITH THE LAST BAND...AND RESULTED IN RAPID WEAKENING OF
TEH BAND OVER THE BGM CWA DUE (AT LEAST IN PART) TO THE LOSS OF
OVER-LAKE TRAJECTORY. THIS IS ALSO HINTED AT IN THE MESO MDLS FRI
MRNG. FOR NOW WE HAVE THE BAND DROPPING SWD INTO ONON/MAD IN THE
09-12Z TIME FRAME...WITH POTNL FOR LOW END ADVISORY ACCUMS MAINLY
OVER NW ONON. GIVEN THE NUMEROUS HEADLINES ALREADY IN EFFECT AND
THE FACT WE HAVE SOME TIME TO TAKE A CLOSER LOOK AT THIS...WE WILL
JUST MENTION THE POTNL IN THE HWO AND LET THE DAYSHIFT ISSUE
HEADLINES FOR THIS EVENT IF NEEDED.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
A COUPLE OF CLIPPER-TYPE SYSTEMS WILL AFFECT THIS WEEKEND...WITH
SCATTERED SNOW SHOWERS. A MORE WDSPRD AREA OF LGT SNOW COULD DVLP
IN THE WARM ADVECTION PTRN AHEAD OF THE CLIPPER APRCHNG SAT NGT.
IN GNRL...CHC POPS FOR -SHSN AND BLO NORMAL TEMPS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
GRIDS WERE ADJUSTED SOME TO ACCOUNT FOR LATEST HPC GUIDANCE AND
GFS/ECMWF MODELS. NO BIG CHANGE TO GOING FORECAST OVERALL...BUT I
DID UPGRADE POPS INTO LIKELY CATEGORY FOR CENTRAL NY AND AT LEAST
HIGHER CHANCE FOR NORTHEAST PA SUNDAY WITH FAIR AGREEMENT ON BEING
INVOLVED IN MERGER BETWEEN DEVELOPING COASTAL LOW AND INCOMING
NORTHERN STREAM SYSTEM/CLIPPER. COULD EASILY RESULT IN LIGHT
COATING OF SNOW. ANOTHER WEAK CLIPPER CONTINUES TO LOOK POSSIBLE
MONDAY NIGHT/TUESDAY.
PREVIOUS DISCUSSION...
FOLLOWED HPC GUIDANCE. MODELS ARE SIMILAR WITH NO LARGE STORMS.
REMAIN UNDER A NORTHEAST US UPPER LEVEL TROF. SEASONABLE WEATHER
WITH WEAK LOW PRESSURE SYSTEMS FOLLOWED BY LAKE EFFECT. ALL PRECIP
WILL BE SNOW WITH HIGHS AROUND 30 AND LOWS IN THE TEENS. THE WEAK
SYSTEMS GO THROUGH SUNDAY AND MONDAY NIGHT...WITH LAKE EFFECT ON
THE OTHER DAYS. COULD BE A 12 HOUR DRY BREAK BETWEEN SYSTEMS WITH
WEAK HIGH PRESSURE MON AFTN.
&&
.AVIATION /11Z THURSDAY THROUGH MONDAY/...
06Z UPDATE...
STRONG WET SYSTEM IS PROGRESSING THROUGH THE REGION. SSE WIND
AHEAD OF THE FRONT...WITH STRONG SSW FLOW NOT FAR OFF THE SURFACE.
FOR KRME AND KAVP...LIKELY MEETING LLWS THRESHOLD AND THUS
INCLUDED INITIALLY IN TAFS. HOWEVER...SURFACE WIND WILL ABRUPTLY
SHIFT TO SW WITH BRIEF HEAVY SHOWERS AS FRONT PASSES...WITH TIMING
AS INDICATED IN TAFS. THOUGH IFR NOT OUT OF QUESTION WITH
FRONT...MAINLY MVFR IS ANTICIPATED AND HAS OCCURRED UPSTREAM.
BEHIND FRONT...WINDS WILL HAVE A MUCH EASIER TIME MIXING
DOWN...MITIGATING ANY FURTHER LLWS BUT ALSO ALLOWING GUSTS
FREQUENTLY IN THE 30-40 KT RANGE. KSYR-KRME COULD EVEN GET A BIT
HIGHER THAN THAT THIS AFTERNOON. SCT-BKN CLOUD DECK DURING THE
DAYTIME HOURS...EVENTUALLY WITH SCT -SHSN AND MVFR CIG FOR SOME
TERMINALS. LAKE ONTARIO SNOW BAND WILL AT FIRST DEVELOP NORTH OF
THE AREA THIS AFTERNOON...BUT SHOULD EDGE SOUTH ENOUGH TO INVOLVE
KRME IN OCCASIONAL IFR VIS 00Z-06Z FRIDAY...AND NOT LONG AFTER
THAT FOR KSYR.
.OUTLOOK...
LATE THU NGT THRU SAT NGT...MVFR-IFR FROM LAKE -SHSN IN CENTRAL NY.
SUN...A COLD FRONT WITH POSSIBLE MVFR AND IFR SNOW
SUN NGT-MON...MORE MVFR/IFR LAKE -SHSN MAINLY CENTRAL NY.
&&
.HYDROLOGY...
CONSENSUS OF MODEL AND MAN MADE GUID PROGS PUTS 1 TO UP TO 2.5
INCHES WITH THE HEAVIEST RAIN AXIS FURTHER WEST ACROSS THE FINGER
LAKES AND CHEMUNG BASINS OF NY. WILL HAVE TWO BATCHES WITH THE
INITIAL BATCH ALREADY IN WRN PA AND WRN NY NOW. THIS FIRST BATCH
MOVES QUICKLY THROUGH THIS AFTN. RAINFALL THIS AFTN UP TO HALF AN
INCH. QUICK RESPONSE ON STREAMS BUT NO FLOODING INITIALLY. THE
COLD FRONT WILL COME THROUGH LATE EVE AND EARLY MORNING WITH MORE
HEAVY RAIN. ANOTHER QUICK INCH IN LESS THAN 6 HOURS WHICH WILL BE
MOSTLY RUNOFF. STREAMS AND RIVERS WILL RESPOND QUICKLY. FLASH
FLOODING POSSIBLE...FOLLOWED BY MINOR RIVER FLOODING.
FLOOD WATCH CONTINUES FOR ENTIRE CWA STARTING AT 4 PM INTO
THURSDAY MORNING. RIVER FLOOD WARNINGS JUST ISSUED FOR
WEST BRANCH DELAWARE RIVER AT WALTON
TIOUGHNIOGA RIVER AT CORTLAND
CHENANGO RIVER AT SHERBURNE
SUSQUEHANNA RIVER AT VESTAL
SUSQUEHANNA RIVER AT WAVERLY/SAYRE
SUSQUEHANNA RIVER AT TOWANDA
SUSQUEHANNA RIVER AT MESHOPPEN
SUSQUEHANNA RIVER NEAR WILKES-BARRE
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ038>040-043-
044-047-048-072.
NY...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ023>025-044-
045-055-056-062.
HIGH WIND WARNING UNTIL 7 PM EST THIS EVENING FOR NYZ009-
015>018-022-036-037-046-057.
LAKE EFFECT SNOW WARNING FROM 1 PM THIS AFTERNOON TO 7 AM EST
FRIDAY FOR NYZ009.
&&
$$
LONG TERM...MDP/TAC
AVIATION...MDP
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
454 AM EST THU JAN 31 2013
.SYNOPSIS...
COLDER AIR WORKING INTO THE AREA BEHIND A STRONG COLD FRONT WILL
PRODUCE STRONG GUSTY WINDS TODAY...IN ADDITION TO LAKE EFFECT
SNOWS DOWNWIND OF LAKES ERIE AND ONTARIO. BELOW NORMAL
TEMPERATURES AND SCATTERED SHOW SHOWERS WILL CONTINUE INTO THE
WEEKEND...DUE TO A COMBINATION OF LAKE EFFECT SNOW SHOWERS AND
WEAK UPPER LEVEL DISTURBANCES.
&&
.NEAR TERM /THROUGH TONIGHT/...
450 AM...DROPPED FLOOD WATCH FOR THER CNTRL SRN TIER AND PORTIONS
OF THE FINGER LAKES AS BACKEDGE OF STEADIER RAIN HAS EXITED THIS
RGN. MAY STILL SEE SOME MINOR FLOODING DUE TO RUNOFF BUT FLS`S
HANDLING THAT. CONVECTIVE FNTL LINE PRODUCED WIND GUSTS IN THE
40-50 MPH RECENTLY AT SYR/BGM. SYNOPTIC SCALE WINDS WILL BE
INCRSNG RAPIDLY LATER THIS MRNG ALL AREAS. PREV BLO...
BACKEDGE OF AREA OF STEADY RAIN AREA MOVING INTO WRN ZONES AS OF
315 AM...CLOSE TO THE PSN OF THE SFC CDFNT...AND WILL CONTINUE IT`S EWD
PROGRESS THROUGH THE EARLY MRNG HRS. SOME OF THE RAIN MAY MIX
BRIEFLY WITH SNOW BEFORE TAPERING OFF THIS MRNG. FLOOD WATCH
REMAINS ON EFFECT...WE HAVE ISSUED SOME FLS`S THUS FAR AND WILL
CONTINUE TO MONITOR CAREFULLY.
MAIN ISSUE TDA WILL BE THE STRONG WINDS DVLPNG THIS MRNG AND
CONTINUING INTO THE AFTN HRS. BASED ON OUR SUSTAINED AND PEAK WIND
GRIDS...WE ADDED STEUBEN...YATES AND SENECA COUNTIES INTO THE
WARNING.
SCATTERED SNOW SHOWERS ARE XPCTD TDA...MAILY DUE TO LAKE
INFLUENCES. WE COULD SEE -SHSN OFF LAKE ERIE ACRS PORTIONS OF THE
TWIN TIERS THIS AFTN/EVNG. POTNL FOR 2-4 INCHES ACRS PORTIONS OF
WRN STEUBEN TNGT. AFTN SHIFT CAN RE-ASSESS AND DETERMINE IF A LOW
END ADVISORY IS NEEDED HERE.
AS FOR THE NRN ONEIDA LES EVENT...THIS EVENT APPEARS TO BE SIMILAR
TO LAST WEEKS. THE ARW PERFORMED WELL IN THAT CASE...AND THIS
MRNG`S RUC ALSO SHOWS GOOD AGREEMENT EARLY ON IN THE PD. IT
APPEARS THAT THE BAND WILL NOT MAKE A MOVE INTO NRN ONEIDA UNTIL
LATE THIS AFTN...PERSISTING OVER THAT AREA TIL ARND 06Z BEFORE
DROPPING SWD AS FLOW BCMS MORE WNWLY. AS THIS OCCURS...MESO MDLS
SHOW THE BAND OVER LAKE ONTARIO DROPPING TO A PSN NEAR/ALONG THE
SRN SHORE OF LAKE ONTARIO LATE TNGT/TWDS DAYBREAK. THIS IS WHAT
OCCURRED WITH THE LAST BAND...AND RESULTED IN RAPID WEAKENING OF
TEH BAND OVER THE BGM CWA DUE (AT LEAST IN PART) TO THE LOSS OF
OVER-LAKE TRAJECTORY. THIS IS ALSO HINTED AT IN THE MESO MDLS FRI
MRNG. FOR NOW WE HAVE THE BAND DROPPING SWD INTO ONON/MAD IN THE
09-12Z TIME FRAME...WITH POTNL FOR LOW END ADVISORY ACCUMS MAINLY
OVER NW ONON. GIVEN THE NUMEROUS HEADLINES ALREADY IN EFFECT AND
THE FACT WE HAVE SOME TIME TO TAKE A CLOSER LOOK AT THIS...WE WILL
JUST MENTION THE POTNL IN THE HWO AND LET THE DAYSHIFT ISSUE
HEADLINES FOR THIS EVENT IF NEEDED.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
A COUPLE OF CLIPPER-TYPE SYSTEMS WILL AFFECT THIS WEEKEND...WITH
SCATTERED SNOW SHOWERS. A MORE WDSPRD AREA OF LGT SNOW COULD DVLP
IN THE WARM ADVECTION PTRN AHEAD OF THE CLIPPER APRCHNG SAT NGT.
IN GNRL...CHC POPS FOR -SHSN AND BLO NORMAL TEMPS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
GRIDS WERE ADJUSTED SOME TO ACCOUNT FOR LATEST HPC GUIDANCE AND
GFS/ECMWF MODELS. NO BIG CHANGE TO GOING FORECAST OVERALL...BUT I
DID UPGRADE POPS INTO LIKELY CATEGORY FOR CENTRAL NY AND AT LEAST
HIGHER CHANCE FOR NORTHEAST PA SUNDAY WITH FAIR AGREEMENT ON BEING
INVOLVED IN MERGER BETWEEN DEVELOPING COASTAL LOW AND INCOMING
NORTHERN STREAM SYSTEM/CLIPPER. COULD EASILY RESULT IN LIGHT
COATING OF SNOW. ANOTHER WEAK CLIPPER CONTINUES TO LOOK POSSIBLE
MONDAY NIGHT/TUESDAY.
PREVIOUS DISCUSSION...
FOLLOWED HPC GUIDANCE. MODELS ARE SIMILAR WITH NO LARGE STORMS.
REMAIN UNDER A NORTHEAST US UPPER LEVEL TROF. SEASONABLE WEATHER
WITH WEAK LOW PRESSURE SYSTEMS FOLLOWED BY LAKE EFFECT. ALL PRECIP
WILL BE SNOW WITH HIGHS AROUND 30 AND LOWS IN THE TEENS. THE WEAK
SYSTEMS GO THROUGH SUNDAY AND MONDAY NIGHT...WITH LAKE EFFECT ON
THE OTHER DAYS. COULD BE A 12 HOUR DRY BREAK BETWEEN SYSTEMS WITH
WEAK HIGH PRESSURE MON AFTN.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
06Z UPDATE...
STRONG WET SYSTEM IS PROGRESSING THROUGH THE REGION. SSE WIND
AHEAD OF THE FRONT...WITH STRONG SSW FLOW NOT FAR OFF THE SURFACE.
FOR KRME AND KAVP...LIKELY MEETING LLWS THRESHOLD AND THUS
INCLUDED INITIALLY IN TAFS. HOWEVER...SURFACE WIND WILL ABRUPTLY
SHIFT TO SW WITH BRIEF HEAVY SHOWERS AS FRONT PASSES...WITH TIMING
AS INDICATED IN TAFS. THOUGH IFR NOT OUT OF QUESTION WITH
FRONT...MAINLY MVFR IS ANTICIPATED AND HAS OCCURRED UPSTREAM.
BEHIND FRONT...WINDS WILL HAVE A MUCH EASIER TIME MIXING
DOWN...MITIGATING ANY FURTHER LLWS BUT ALSO ALLOWING GUSTS
FREQUENTLY IN THE 30-40 KT RANGE. KSYR-KRME COULD EVEN GET A BIT
HIGHER THAN THAT THIS AFTERNOON. SCT-BKN CLOUD DECK DURING THE
DAYTIME HOURS...EVENTUALLY WITH SCT -SHSN AND MVFR CIG FOR SOME
TERMINALS. LAKE ONTARIO SNOW BAND WILL AT FIRST DEVELOP NORTH OF
THE AREA THIS AFTERNOON...BUT SHOULD EDGE SOUTH ENOUGH TO INVOLVE
KRME IN OCCASIONAL IFR VIS 00Z-06Z FRIDAY...AND NOT LONG AFTER
THAT FOR KSYR.
.OUTLOOK...
LATE THU NGT THRU SAT NGT...MVFR-IFR FROM LAKE -SHSN IN CENTRAL NY.
SUN...A COLD FRONT WITH POSSIBLE MVFR AND IFR SNOW
SUN NGT-MON...MORE MVFR/IFR LAKE -SHSN MAINLY CENTRAL NY.
&&
.HYDROLOGY...
CONSENSUS OF MODEL AND MAN MADE GUID PROGS PUTS 1 TO UP TO 2.5
INCHES WITH THE HEAVIEST RAIN AXIS FURTHER WEST ACROSS THE FINGER
LAKES AND CHEMUNG BASINS OF NY. WILL HAVE TWO BATCHES WITH THE
INITIAL BATCH ALREADY IN WRN PA AND WRN NY NOW. THIS FIRST BATCH
MOVES QUICKLY THROUGH THIS AFTN. RAINFALL THIS AFTN UP TO HALF AN
INCH. QUICK RESPONSE ON STREAMS BUT NO FLOODING INITIALLY. THE
COLD FRONT WILL COME THROUGH LATE EVE AND EARLY MORNING WITH MORE
HEAVY RAIN. ANOTHER QUICK INCH IN LESS THAN 6 HOURS WHICH WILL BE
MOSTLY RUNOFF. STREAMS AND RIVERS WILL RESPOND QUICKLY. FLASH
FLOODING POSSIBLE...FOLLOWED BY MINOR RIVER FLOODING.
FLOOD WATCH CONTINUES FOR ENTIRE CWA STARTING AT 4 PM INTO
THURSDAY MORNING. RIVER FLOOD WARNINGS JUST ISSUED FOR
WEST BRANCH DELAWARE RIVER AT WALTON
TIOUGHNIOGA RIVER AT CORTLAND
CHENANGO RIVER AT SHERBURNE
SUSQUEHANNA RIVER AT VESTAL
SUSQUEHANNA RIVER AT WAVERLY/SAYRE
SUSQUEHANNA RIVER AT TOWANDA
SUSQUEHANNA RIVER AT MESHOPPEN
SUSQUEHANNA RIVER NEAR WILKES-BARRE
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...FLOOD WATCH UNTIL 7 AM EST THIS MORNING FOR PAZ039-040-043-044-
047-048-072.
WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ038>040-043-
044-047-048-072.
NY...FLOOD WATCH UNTIL 7 AM EST THIS MORNING FOR NYZ009-018-036-037-
044>046-056-057-062.
WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ023>025-044-
045-055-056-062.
HIGH WIND WARNING UNTIL 7 PM EST THIS EVENING FOR NYZ009-
015>018-022-036-037-046-057.
LAKE EFFECT SNOW WARNING FROM 1 PM THIS AFTERNOON TO 7 AM EST
FRIDAY FOR NYZ009.
&&
$$
LONG TERM...MDP/TAC
AVIATION...MDP
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
332 AM EST THU JAN 31 2013
.SYNOPSIS...
COLDER AIR WORKING INTO THE AREA BEHIND A STRONG COLD FRONT WILL
PRODUCE STRONG GUSTY WINDS TODAY...IN ADDITION TO LAKE EFFECT
SNOWS DOWNWIND OF LAKES ERIE AND ONTARIO. BELOW NORMAL
TEMPERATURES AND SCATTERED SHOW SHOWERS WILL CONTINUE INTO THE
WEEKEND...DUE TO A COMBINATION OF LAKE EFFECT SNOW SHOWERS AND
WEAK UPPER LEVEL DISTURBANCES.
&&
.NEAR TERM /THROUGH TONIGHT/...
BACKEDGE OF AREA OF STEADY RAIN AREA MOVING INTO WRN ZONES AS OF
315 AM...CLOSE TO THE PSN OF THE SFC CDFNT...AND WILL CONTINUE IT`S EWD
PROGRESS THROUGH THE EARLY MRNG HRS. SOME OF THE RAIN MAY MIX
BRIEFLY WITH SNOW BEFORE TAPERING OFF THIS MRNG. FLOOD WATCH
REMAINS ON EFFECT...WE HAVE ISSUED SOME FLS`S THUS FAR AND WILL
CONTINUE TO MONITOR CAREFULLY.
MAIN ISSUE TDA WILL BE THE STRONG WINDS DVLPNG THIS MRNG AND
CONTINUING INTO THE AFTN HRS. BASED ON OUR SUSTAINED AND PEAK WIND
GRIDS...WE ADDED STEUBEN...YATES AND SENECA COUNTIES INTO THE
WARNING.
SCATTERED SNOW SHOWERS ARE XPCTD TDA...MAILY DUE TO LAKE
INFLUENCES. WE COULD SEE -SHSN OFF LAKE ERIE ACRS PORTIONS OF THE
TWIN TIERS THIS AFTN/EVNG. POTNL FOR 2-4 INCHES ACRS PORTIONS OF
WRN STEUBEN TNGT. AFTN SHIFT CAN RE-ASSESS AND DETERMINE IF A LOW
END ADVISORY IS NEEDED HERE.
AS FOR THE NRN ONEIDA LES EVENT...THIS EVENT APPEARS TO BE SIMILAR
TO LAST WEEKS. THE ARW PERFORMED WELL IN THAT CASE...AND THIS
MRNG`S RUC ALSO SHOWS GOOD AGREEMENT EARLY ON IN THE PD. IT
APPEARS THAT THE BAND WILL NOT MAKE A MOVE INTO NRN ONEIDA UNTIL
LATE THIS AFTN...PERSISTING OVER THAT AREA TIL ARND 06Z BEFORE
DROPPING SWD AS FLOW BCMS MORE WNWLY. AS THIS OCCURS...MESO MDLS
SHOW THE BAND OVER LAKE ONTARIO DROPPING TO A PSN NEAR/ALONG THE
SRN SHORE OF LAKE ONTARIO LATE TNGT/TWDS DAYBREAK. THIS IS WHAT
OCCURRED WITH THE LAST BAND...AND RESULTED IN RAPID WEAKENING OF
TEH BAND OVER THE BGM CWA DUE (AT LEAST IN PART) TO THE LOSS OF
OVER-LAKE TRAJECTORY. THIS IS ALSO HINTED AT IN THE MESO MDLS FRI
MRNG. FOR NOW WE HAVE THE BAND DROPPING SWD INTO ONON/MAD IN THE
09-12Z TIME FRAME...WITH POTNL FOR LOW END ADVISORY ACCUMS MAINLY
OVER NW ONON. GIVEN THE NUMEROUS HEADLINES ALREADY IN EFFECT AND
THE FACT WE HAVE SOME TIME TO TAKE A CLOSER LOOK AT THIS...WE WILL
JUST MENTION THE POTNL IN THE HWO AND LET THE DAYSHIFT ISSUE
HEADLINES FOR THIS EVENT IF NEEDED.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
A COUPLE OF CLIPPER-TYPE SYSTEMS WILL AFFECT THIS WEEKEND...WITH
SCATTERED SNOW SHOWERS. A MORE WDSPRD AREA OF LGT SNOW COULD DVLP
IN THE WARM ADVECTION PTRN AHEAD OF THE CLIPPER APRCHNG SAT NGT.
IN GNRL...CHC POPS FOR -SHSN AND BLO NORMAL TEMPS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
GRIDS WERE ADJUSTED SOME TO ACCOUNT FOR LATEST HPC GUIDANCE AND
GFS/ECMWF MODELS. NO BIG CHANGE TO GOING FORECAST OVERALL...BUT I
DID UPGRADE POPS INTO LIKELY CATEGORY FOR CENTRAL NY AND AT LEAST
HIGHER CHANCE FOR NORTHEAST PA SUNDAY WITH FAIR AGREEMENT ON BEING
INVOLVED IN MERGER BETWEEN DEVELOPING COASTAL LOW AND INCOMING
NORTHERN STREAM SYSTEM/CLIPPER. COULD EASILY RESULT IN LIGHT
COATING OF SNOW. ANOTHER WEAK CLIPPER CONTINUES TO LOOK POSSIBLE
MONDAY NIGHT/TUESDAY.
PREVIOUS DISCUSSION...
FOLLOWED HPC GUIDANCE. MODELS ARE SIMILAR WITH NO LARGE STORMS.
REMAIN UNDER A NORTHEAST US UPPER LEVEL TROF. SEASONABLE WEATHER
WITH WEAK LOW PRESSURE SYSTEMS FOLLOWED BY LAKE EFFECT. ALL PRECIP
WILL BE SNOW WITH HIGHS AROUND 30 AND LOWS IN THE TEENS. THE WEAK
SYSTEMS GO THROUGH SUNDAY AND MONDAY NIGHT...WITH LAKE EFFECT ON
THE OTHER DAYS. COULD BE A 12 HOUR DRY BREAK BETWEEN SYSTEMS WITH
WEAK HIGH PRESSURE MON AFTN.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
06Z UPDATE...
STRONG WET SYSTEM IS PROGRESSING THROUGH THE REGION. SSE WIND
AHEAD OF THE FRONT...WITH STRONG SSW FLOW NOT FAR OFF THE SURFACE.
FOR KRME AND KAVP...LIKELY MEETING LLWS THRESHOLD AND THUS
INCLUDED INITIALLY IN TAFS. HOWEVER...SURFACE WIND WILL ABRUPTLY
SHIFT TO SW WITH BRIEF HEAVY SHOWERS AS FRONT PASSES...WITH TIMING
AS INDICATED IN TAFS. THOUGH IFR NOT OUT OF QUESTION WITH
FRONT...MAINLY MVFR IS ANTICIPATED AND HAS OCCURRED UPSTREAM.
BEHIND FRONT...WINDS WILL HAVE A MUCH EASIER TIME MIXING
DOWN...MITIGATING ANY FURTHER LLWS BUT ALSO ALLOWING GUSTS
FREQUENTLY IN THE 30-40 KT RANGE. KSYR-KRME COULD EVEN GET A BIT
HIGHER THAN THAT THIS AFTERNOON. SCT-BKN CLOUD DECK DURING THE
DAYTIME HOURS...EVENTUALLY WITH SCT -SHSN AND MVFR CIG FOR SOME
TERMINALS. LAKE ONTARIO SNOW BAND WILL AT FIRST DEVELOP NORTH OF
THE AREA THIS AFTERNOON...BUT SHOULD EDGE SOUTH ENOUGH TO INVOLVE
KRME IN OCCASIONAL IFR VIS 00Z-06Z FRIDAY...AND NOT LONG AFTER
THAT FOR KSYR.
.OUTLOOK...
LATE THU NGT THRU SAT NGT...MVFR-IFR FROM LAKE -SHSN IN CENTRAL NY.
SUN...A COLD FRONT WITH POSSIBLE MVFR AND IFR SNOW
SUN NGT-MON...MORE MVFR/IFR LAKE -SHSN MAINLY CENTRAL NY.
&&
.HYDROLOGY...
CONSENSUS OF MODEL AND MAN MADE GUID PROGS PUTS 1 TO UP TO 2.5
INCHES WITH THE HEAVIEST RAIN AXIS FURTHER WEST ACROSS THE FINGER
LAKES AND CHEMUNG BASINS OF NY. WILL HAVE TWO BATCHES WITH THE
INITIAL BATCH ALREADY IN WRN PA AND WRN NY NOW. THIS FIRST BATCH
MOVES QUICKLY THROUGH THIS AFTN. RAINFALL THIS AFTN UP TO HALF AN
INCH. QUICK RESPONSE ON STREAMS BUT NO FLOODING INITIALLY. THE
COLD FRONT WILL COME THROUGH LATE EVE AND EARLY MORNING WITH MORE
HEAVY RAIN. ANOTHER QUICK INCH IN LESS THAN 6 HOURS WHICH WILL BE
MOSTLY RUNOFF. STREAMS AND RIVERS WILL RESPOND QUICKLY. FLASH
FLOODING POSSIBLE...FOLLOWED BY MINOR RIVER FLOODING.
FLOOD WATCH CONTINUES FOR ENTIRE CWA STARTING AT 4 PM INTO
THURSDAY MORNING. RIVER FLOOD WARNINGS JUST ISSUED FOR
WEST BRANCH DELAWARE RIVER AT WALTON
TIOUGHNIOGA RIVER AT CORTLAND
CHENANGO RIVER AT SHERBURNE
SUSQUEHANNA RIVER AT VESTAL
SUSQUEHANNA RIVER AT WAVERLY/SAYRE
SUSQUEHANNA RIVER AT TOWANDA
SUSQUEHANNA RIVER AT MESHOPPEN
SUSQUEHANNA RIVER NEAR WILKES-BARRE
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...FLOOD WATCH UNTIL 7 AM EST THIS MORNING FOR PAZ038>040-043-044-
047-048-072.
WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ038>040-043-
044-047-048-072.
NY...FLOOD WATCH UNTIL 7 AM EST THIS MORNING FOR NYZ009-015>018-
022>025-036-037-044>046-055>057-062.
WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ023>025-044-
045-055-056-062.
HIGH WIND WARNING UNTIL 7 PM EST THIS EVENING FOR NYZ009-
015>018-022-036-037-046-057.
LAKE EFFECT SNOW WARNING FROM 1 PM THIS AFTERNOON TO 7 AM EST
FRIDAY FOR NYZ009.
&&
$$
LONG TERM...MDP/TAC
AVIATION...MDP
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1157 PM EST WED JAN 30 2013
.SYNOPSIS...
RAIN...HEAVY AT TIMES WILL FALL ACROSS THE REGION TONIGHT AHEAD OF A
COLD FRONT THAT WILL SWEEP ACROSS THE REGION WHICH WILL SEND
TEMPERATURES BACK TO SEASONAL NORMALS. AS THE COLD AIR DEEPENS ON
THURSDAY...LAKE EFFECT SNOWS WILL SET UP IN THE TRADITIONAL
SNOWBELTS EAST AND SOUTHEAST OF THE LAKES...THEN WILL CONTINUE
THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
LOW PRESSURE ACROSS LAKE HURON WILL LIFT NORTHEAST ACROSS SOUTHERN
ONTARIO OVERNIGHT. THIS WILL BRING A COLD FRONT ACROSS THE REGION
TONIGHT...FORECAST TO ENTER FAR WESTERN NEW YORK AROUND
MIDNIGHT...THEN SWEEP RAPIDLY TO THE EAST THROUGH THE EARLY
MORNING HOURS. THIS WILL CAUSE AN ABRUPT DROP IN TEMPERATURES...AND
KEY THE ONSET IN GUSTY WINDS. EXPECT WIND GUSTS WILL PUSH 50 MPH
IMMEDIATELY BEHIND THE FRONT...BEFORE THE STEADIER WINDS AHEAD OF
A SECONDARY SHOT OF COLDER AIR.
IN ADDITION....THIS SYSTEM WILL SET UP A DEEP SOUTHERLY FLOW OUT
AHEAD OF IT...WHICH WILL TRANSPORT MOISTURE FROM PENNSYLVANIA AND
INTO CENTRAL NEW YORK TONIGHT. A BLEND OF RADAR AND HRRR MODEL
GUIDANCE THROUGH 1100 PM SUGGEST THE HEAVIEST RAINS WILL SLIDE A
BIT FURTHER EAST...MAINLY IMPACTING LOCATIONS EAST OF LAKE
ONTARIO. BECAUSE OF THIS...HAVE MODIFIED THE FLOOD WATCH. REFER TO
THE HYDROLOGY SECTION FOR MORE ON THIS.
THE SYSTEM WILL CAUSE MULTIPLE ISSUES FOR THE CWA...ORGANIZED BY
IMPACT BELOW.
1. STRONG WINDS...THE AFOREMENTIONED STORM SYSTEM WILL DEEPEN FROM
AROUND 985MB 00Z TONIGHT TO 970MB 12Z TOMORROW MORNING JUST NORTH OF
VERMONT...AND THEN BELOW 960 MB BY 00Z FRIDAY ACROSS EASTERN QUEBEC.
THIS RAPID DEEPENING...COMBINED WITH 6 TO 8 MB ISALLOBARIC PRESSURE
RISES WITHIN COLD AIR ADVECTION FOLLOWING THE COLD FRONT SHOULD BE
ABLE TO MIX A 50 KNOT JET AT 925 HPA DOWN TO THE SURFACE. GIVEN THE
STRONG AND VERY DYNAMIC NATURE OF THIS SYSTEM...ITS ASSOCIATED WIND
FIELDS WILL ALSO BE QUITE STRONG. WE WILL UPGRADE THE ADVISORY TO A
WARNING FOR A GOOD PORTION OF THE CWA. WIND GUSTS UP TO 60 MPH ARE
LIKELY IN FAVORED AREAS ALONG THE LAKE ERIE SHORELINE INLAND ACROSS
SOUTHERN LAKE ONTARIO AND THROUGH THE EASTERN LAKE ONTARIO REGION.
FOR OUR INLAND COUNTIES OF WYOMING...ALLEGANY...LIVINGSTON AND
ONTARIO WE WILL LEAVE A HIGH END WIND ADVISORY AS THE DEEPENING LOW
MAY BE TOO FAR NORTH TO ALLOW FOR WARNING CRITERIA WINDS HERE.
2. LAKE EFFECT SNOW...FOLLOWING THE PASSAGE OF THE COLD FRONT -14C
TO -16C 850 HPA AIR TEMPERATURES WILL BE CROSSING THE LAKES. AT
FIRST WINDS MAY BE TO STRONG FOR GOOD FORMATION OF LAKE EFFECT SNOW
BANDS WITH THE WINDS SHEARING AWAY THE LAKE BAND FORMATION. ALSO
WITH THE STRONG WINDS RESIDENT TIME OVER THE LAKE BODIES WILL BE
LIMITED. AS WINDS DIMINISH THROUGH THE AFTERNOON AND COLD AIR
DEEPENS...AND LAKE INDUCED EQUILIBRIUM LEVELS RISE TOWARDS 7 TO 9K
FEET A BAND OF SNOW SHOULD BE FORMING OFF BOTH LAKE ERIE AND LAKE
ONTARIO. THE NAM...AND TO A DEGREE THE GFS HAS DEEP SYNOPTIC
MOISTURE REMAINING IN THE SNOW GROWTH ZONE...WHICH WILL BE FALLING
WITH THE COLD AIR ADVECTION.
OFF LAKE ONTARIO...WIND FIELD CONVERGENCE OVER LAKE ONTARIO IS
LEADING TO IMPRESSIVE OMEGA FIELDS BY THURSDAY AFTERNOON WHERE A
BAND OF LAKE EFFECT SNOW MAY BEGIN TO PRODUCE SNOWFALL RATES UP TO 2
INCHES PER HOUR. FOLLOWING THE SURFACE LOW AND UPPER LEVEL TROUGH
WINDS WILL BEGIN TO VEER THROUGH THE DAY DROPPING THE LAKE EFFECT
SNOW BAND SOUTH OF JEFFERSON COUNTY. FOR THIS REASON WILL LEAVE
JEFFERSON COUNTY AS A HIGH END LAKE EFFECT SNOW ADVISORY...AND HAVE
WARNINGS FOR LEWIS AND OSWEGO COUNTIES WHERE THE BAND WILL LIKELY
FALL LONGER.
OFF LAKE ERIE...A WESTERLY FLOW OVER THE STILL OPEN WATERS OF LAKE
ERIE WILL BRING MULTI BANDED STRUCTURE SNOW BANDS ACROSS THE SOUTHERN
TIER. CONFIDENCE IS GREATER ACROSS CHAUTAUQUA AND CATTARAUGUS COUNTIES
THAN SOUTHERN ERIE AND WYOMING COUNTIES FOR WARNING CRITERIA SNOW.
WILL UPGRADE THE WATCH TO A LAKE EFFECT WARNING ACROSS THE SOUTHERN
TIER...WHILE LEAVING ADVISORIES FOR SOUTHERN TIER AND WYOMING
COUNTIES.
3. REGARDING TEMPERATURES...RECORDED HIGHS WERE SHATTERED ACROSS
MUCH OF THE REGION TODAY WITH MORNING AND EARLY AFTERNOON HIGHS
REACHING NEAR 10 DEGREES ABOVE RECORD VALUES FOR THE DATE.
THE NEW RECORDS FOR TODAY...
BUFFALO.....66 (PREVIOUS WAS 56 IN 1916)
ROCHESTER...64 (PREVIOUS WAS 55 IN 1974)
WATERTOWN...63 (PREVIOUS WAS 52 IN 1995)
THESE READINGS ARE STILL SEVERAL DEGREES SHY OF THE ALLTIME
MONTHLY RECORD HIGH TEMPERATURE WHICH ARE AS FOLLOWS:
BUFFALO.....72 IN 1950.
ROCHESTER...74 IN 1950...CORRECTED
WATERTOWN...66 IN 1995.
THE COLD FRONT WILL SWEEP ACROSS THE REGION TONIGHT SENDING
TEMPERATURES BACK TO SEASONAL NORMS...WITH MANY AREAS DOWN INTO THE
UPPER 20S AND LOW 30S BY TOMORROW MORNING. WITH THE RAIN OVERNIGHT
THE PROSPECTS FOR BLACK ICE WILL BE PRESENT AS WE QUICKLY COOL
FURTHER INTO THE MID AND UPPER 20S BY MID MORNING.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
HEAVY LAKE EFFECT SNOWS SHOULD BE ONGOING ON A WESTERLY FLOW
REGIME AT THE START OF THE PERIOD. BUFR PROFILES FROM THURSDAY
NIGHT THROUGH AT LEAST THE DAYTIME HOURS OF FRIDAY CONTINUE TO
LOOK RATHER IMPRESSIVE...AS A DEEP LAYERED CYCLONIC FLOW REGIME IS
WELL ESTABLISHED. MOISTURE PROFILES LOOK QUITE ADEQUATE WITH
SATURATION WELL UP THROUGH 10K FEET AND DEEPER AT TIMES AS A
COUPLE OF REINFORCING WEAK SHORTWAVES WORK THROUGH THE MEAN WEST
NORTHWEST FLOW. THE BIGGEST FACTOR THAT COULD LIMIT TOTALS WILL BE
THE VEERING WINDS IN RESPONSE TO A SHORTWAVE CROSSING THE LOWER
LAKES. THIS WILL TEND TO PUSH THE LAKE BANDS...ESPECIALLY ACROSS
LAKE ONTARIO SOUTHWARD. THIS COULD BRING THE PRIME LAKE EFFECT
FOCUS ALONG THE SOUTH SHORE OF LAKE ONTARIO...WHICH COULD BRING AT
LEAST ADVISORY OR GREATER TOTALS TO THIS AREA INCLUDING THE
ROCHESTER METRO AREA. FEEL A BIT MORE CONFIDENT WITH THE AREA FROM
WAYNE OVER TO NORTHERN CAYUGA AT THIS POINT...THEREFORE WILL ISSUE
A LAKE EFFECT SNOW WATCH FOR THAT AREA...BUT IT IS HIGHLY POSSIBLE
THAT LAKE EFFECT HEADLINES MAY NEED TO BE ISSUED FARTHER TO THE
WEST.
ANOTHER SHORTWAVE APPROACHING THE REGION FRIDAY NIGHT AND SATURDAY
MAY REORIENT THE LAKES SNOWS FOR A TIME NORTHWARD AS THE FLOW
BACKS TO WEST SOUTHWEST...POTENTIALLY BRINGING SOME ACCUMULATING
SNOWS INTO PORTIONS OF THE BUFFALO METRO AND WATERTOWN AREAS. THE
PASSAGE OF THE SHORTWAVE SHOULD RE-ESTABLISH THE LAKE SNOWS BACK
SOUTHWARD LATER SATURDAY AND SATURDAY NIGHT.
MUCH COLDER AIR MASS ACROSS THE AREA FRIDAY AND SATURDAY WITH
DAYTIME HIGHS IN THE TEENS AND 20S...WITH WIND CHILLS PERIODICALLY
BELOW ZERO.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
THE VERY COLD AIR REMAINS IN PLACE SUNDAY...BEFORE A GRADUAL
MODIFICATION OF THE AIR MASS OCCURS INTO EARLY NEXT WEEK AS THE
UPPER TROUGH SHIFTS TO THE EAST. TWO CLIPPER TYPE WAVES LOOK TO
IMPACT THE LOWER LAKES REGION DURING THIS TIME FRAME. ONE WAVE MOVES
THROUGH ON SUNDAY WHICH MAY SERVE TO ENHANCE THE ONGOING LAKE EFFECT
SNOWS IN A WESTERLY FLOW REGIME. THE SECOND WAVE LOOKS TO MOVE
THROUGH LATE MONDAY OR EARLY TUESDAY AND APPEARS TO BE RATHER ROBUST
AND GIVEN THE PROJECTED TRACK OF THE ASSOCIATED SURFACE LOW COULD
BRING THE POTENTIAL FOR A GENERAL WIDESPREAD SEVERAL INCHES OF SNOW.
BEHIND THIS WAKE A COLDER FLOW DEVELOPS WHICH MAY REDEVELOP SOME
LAKE SNOWS BUT LACK OF SIGNIFICANT MOISTURE COULD LIMIT SNOWFALL
POTENTIAL.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
A COLD FRONT ACROSS BUF/IAG/JHW AT 06Z WILL RACE TO THE
EAST...REACHING ART AROUND 09Z. THIS FRONT WILL TRIGGER AN ABRUPT
INCREASE IN WINDS...WHICH WILL LAST THROUGH MUCH OF THE
DAY...BEFORE TAPERING OFF LATE THURSDAY AFTERNOON.
MEANWHILE...RAIN SHOWER AHEAD OF THE FRONT WILL CONTINUE TO SLIDE
EAST DURING THE EARLY MORNING HOURS. TEMPERATURES WILL COOL BEHIND
THE FRONT...WHICH WILL SET UP LAKE SNOWS EAST OF THE LAKES. THESE
SHOULD LARGELY MISS BUF/IAG/ROC FOR MOST OF TODAY AND THIS
EVENING. LAKE SNOWS WILL PROBABLY IMPACT JHW/ART FOR A
PERIOD...WITH IFR OR LOWER CONDITIONS POSSIBLE.
OUTLOOK...
THURSDAY NIGHT THROUGH SATURDAY...MVFR WITH LOCALIZED IFR IN LAKE
EFFECT SNOW EAST OF THE LAKES.
SUNDAY...MAINLY VFR WITH MVFR IN LOCALIZED LAKE EFFECT SNOW SHOWERS.
MONDAY...VFR.
&&
.MARINE...
A COMPLEX AREA OF LOW PRESSURE FROM SOUTHERN CANADA AND THROUGH THE
CENTRAL GREAT LAKES REGION THIS AFTERNOON WILL LIFT NORTHEASTWARD
AND DEEPEN TONIGHT AND TOMORROW. A COLD FRONT SWINGING ACROSS THE
LAKES...COUPLED WITH STRONG COLD AIR ADVECTION AND RAPID DEEPENING
OF THE SURFACE LOW WILL INCREASE WINDS QUICKLY TO GALE FORCE
FOLLOWING THE PASSAGE OF THE FRONT TONIGHT...WITH GALES THEN
CONTINUING THROUGH MUCH OF THURSDAY. FOR THIS REASON...GALE WARNINGS
WILL CONTINUE AS OUTLINED ON THE LAKES. WINDS AND WAVES WILL STILL
REMAIN STRONG THURSDAY EVENING THROUGH SATURDAY...BEFORE DIMINISHING
TO BELOW SMALL CRAFT CONDITIONS BY SATURDAY NIGHT.
&&
.HYDROLOGY...
FOLLOWING A BLEND OF RADAR AND NEAR TERM GUIDANCE...IT APPEARS THE
STEADIEST RAINS WILL FALL EAST OF LAKE ONTARIO...WITH LESSER
AMOUNTS WEST OF THE GENESEE RIVER. EAST OF LAKE ONTARIO...EXPECT
AROUND AN INCH OF RAIN TO FALL...WITH LESS THAN THAT WEST OF THE
GENESEE. LATEST RFC FORECASTS HAVE LOWERED CRESTS AT
WELLSVILLE...WITH THE MAJORITY OF MMEFS GUIDANCE KEEPING THE
BUFFALO CREEKS...GENESEE RIVER...AND ALLEGHENY RIVER BELOW FLOOD
STAGE. THERE STILL MAY BE A FEW LINGERING ICE JAMS IN TYPICALLY
FLOOD PRONE AREAS IN PARTS OF CHAUTAUQUA COUNTY.
THERE STILL A THREAT FOR FLOODING IN EASTERN PORTIONS...WHERE AN
INCH OF RAINFALL STILL APPEARS LIKELY. LOCALLY HIGHER AMOUNTS FROM
CONVECTION AND/OR UPSLOPING MAY ALSO OCCUR. THIS COMBINED WITH
SNOW MELT FROM LOCATIONS EAST OF LAKE ONTARIO WILL RESULT IN
SIGNIFICANT RISES IN THE RIVERS AND CREEKS. AN INCH OF RAIN IS
STILL MARGINAL TO CAUSE FLOODING...BUT WITH SNOW MELT QUITE
DIFFICULT TO FORECAST...AND SOME ICE JAMS POSSIBLE...THERE IS A
CONTINUED RISK OF FLOODING. THE SREF AND TO A LESSER EXTENT GFS/GGEM
BASED MMEFS ENSEMBLES POINT TO THIS POTENTIAL.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...HIGH WIND WARNING UNTIL 4 PM EST THURSDAY FOR NYZ001>008-010-
011-019-020-085.
LAKE EFFECT SNOW ADVISORY FROM 10 AM THURSDAY TO 6 PM EST
FRIDAY FOR NYZ012-085.
LAKE EFFECT SNOW ADVISORY FROM 10 AM THURSDAY TO 1 AM EST
FRIDAY FOR NYZ007.
FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR NYZ004>008-014.
LAKE EFFECT SNOW WARNING FROM 10 AM THURSDAY TO 6 PM EST
FRIDAY FOR NYZ006-008-019-020.
LAKE EFFECT SNOW WATCH FROM THURSDAY EVENING THROUGH FRIDAY
AFTERNOON FOR NYZ004-005.
WIND ADVISORY UNTIL 4 PM EST THURSDAY FOR NYZ012>014-021.
MARINE...GALE WARNING UNTIL 4 PM EST THURSDAY FOR LEZ040-041.
GALE WARNING UNTIL 10 AM EST THURSDAY FOR LEZ020.
SMALL CRAFT ADVISORY UNTIL 4 PM EST THURSDAY FOR
LOZ030.
GALE WARNING UNTIL 4 PM EST THURSDAY FOR LOZ042>045-
062>065.
&&
$$
SYNOPSIS...THOMAS
NEAR TERM...APFFEL/THOMAS
SHORT TERM...TMA
LONG TERM...TMA
AVIATION...APFFEL
MARINE...APFFEL/THOMAS
HYDROLOGY...APFFEL
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1112 PM EST WED JAN 30 2013
.SYNOPSIS...
RAIN...HEAVY AT TIMES WILL FALL ACROSS THE REGION TONIGHT AHEAD OF A
COLD FRONT THAT WILL SWEEP ACROSS THE REGION WHICH WILL SEND
TEMPERATURES BACK TO SEASONAL NORMALS. AS THE COLD AIR DEEPENS ON
THURSDAY...LAKE EFFECT SNOWS WILL SET UP IN THE TRADITIONAL
SNOWBELTS EAST AND SOUTHEAST OF THE LAKES...THEN WILL CONTINUE
THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
LOW PRESSURE ACROSS LAKE HURON WILL LIFT NORTHEAST ACROSS SOUTHERN
ONTARIO OVERNIGHT. THIS WILL BRING A COLD FRONT ACROSS THE REGION
TONIGHT...FORECAST TO ENTER FAR WESTERN NEW YORK AROUND
MIDNIGHT...THEN SWEEP RAPIDLY TO THE EAST THROUGH THE EARLY
MORNING HOURS. THIS WILL CAUSE AN ABRUPT DROP IN TEMPERATURES...AND
KEY THE ONSET IN GUSTY WINDS. EXPECT WIND GUSTS WILL PUSH 50 MPH
IMMEDIATELY BEHIND THE FRONT...BEFORE THE STEADIER WINDS AHEAD OF
A SECONDARY SHOT OF COLDER AIR.
IN ADDITION....THIS SYSTEM WILL SET UP A DEEP SOUTHERLY FLOW OUT
AHEAD OF IT...WHICH WILL TRANSPORT MOISTURE FROM PENNSYLVANIA AND
INTO CENTRAL NEW YORK TONIGHT. A BLEND OF RADAR AND HRRR MODEL
GUIDANCE THROUGH 1100 PM SUGGEST THE HEAVIEST RAINS WILL SLIDE A
BIT FURTHER EAST...MAINLY IMPACTING LOCATIONS EAST OF LAKE
ONTARIO. BECAUSE OF THIS...HAVE MODIFIED THE FLOOD WATCH. REFER TO
THE HYDROLOGY SECTION FOR MORE ON THIS.
THE SYSTEM WILL CAUSE MULTIPLE ISSUES FOR THE CWA...ORGANIZED BY
IMPACT BELOW.
1. STRONG WINDS...THE AFOREMENTIONED STORM SYSTEM WILL DEEPEN FROM
AROUND 985MB 00Z TONIGHT TO 970MB 12Z TOMORROW MORNING JUST NORTH OF
VERMONT...AND THEN BELOW 960 MB BY 00Z FRIDAY ACROSS EASTERN QUEBEC.
THIS RAPID DEEPENING...COMBINED WITH 6 TO 8 MB ISALLOBARIC PRESSURE
RISES WITHIN COLD AIR ADVECTION FOLLOWING THE COLD FRONT SHOULD BE
ABLE TO MIX A 50 KNOT JET AT 925 HPA DOWN TO THE SURFACE. GIVEN THE
STRONG AND VERY DYNAMIC NATURE OF THIS SYSTEM...ITS ASSOCIATED WIND
FIELDS WILL ALSO BE QUITE STRONG. WE WILL UPGRADE THE ADVISORY TO A
WARNING FOR A GOOD PORTION OF THE CWA. WIND GUSTS UP TO 60 MPH ARE
LIKELY IN FAVORED AREAS ALONG THE LAKE ERIE SHORELINE INLAND ACROSS
SOUTHERN LAKE ONTARIO AND THROUGH THE EASTERN LAKE ONTARIO REGION.
FOR OUR INLAND COUNTIES OF WYOMING...ALLEGANY...LIVINGSTON AND
ONTARIO WE WILL LEAVE A HIGH END WIND ADVISORY AS THE DEEPENING LOW
MAY BE TOO FAR NORTH TO ALLOW FOR WARNING CRITERIA WINDS HERE.
2. LAKE EFFECT SNOW...FOLLOWING THE PASSAGE OF THE COLD FRONT -14C
TO -16C 850 HPA AIR TEMPERATURES WILL BE CROSSING THE LAKES. AT
FIRST WINDS MAY BE TO STRONG FOR GOOD FORMATION OF LAKE EFFECT SNOW
BANDS WITH THE WINDS SHEARING AWAY THE LAKE BAND FORMATION. ALSO
WITH THE STRONG WINDS RESIDENT TIME OVER THE LAKE BODIES WILL BE
LIMITED. AS WINDS DIMINISH THROUGH THE AFTERNOON AND COLD AIR
DEEPENS...AND LAKE INDUCED EQUILIBRIUM LEVELS RISE TOWARDS 7 TO 9K
FEET A BAND OF SNOW SHOULD BE FORMING OFF BOTH LAKE ERIE AND LAKE
ONTARIO. THE NAM...AND TO A DEGREE THE GFS HAS DEEP SYNOPTIC
MOISTURE REMAINING IN THE SNOW GROWTH ZONE...WHICH WILL BE FALLING
WITH THE COLD AIR ADVECTION.
OFF LAKE ONTARIO...WIND FIELD CONVERGENCE OVER LAKE ONTARIO IS
LEADING TO IMPRESSIVE OMEGA FIELDS BY THURSDAY AFTERNOON WHERE A
BAND OF LAKE EFFECT SNOW MAY BEGIN TO PRODUCE SNOWFALL RATES UP TO 2
INCHES PER HOUR. FOLLOWING THE SURFACE LOW AND UPPER LEVEL TROUGH
WINDS WILL BEGIN TO VEER THROUGH THE DAY DROPPING THE LAKE EFFECT
SNOW BAND SOUTH OF JEFFERSON COUNTY. FOR THIS REASON WILL LEAVE
JEFFERSON COUNTY AS A HIGH END LAKE EFFECT SNOW ADVISORY...AND HAVE
WARNINGS FOR LEWIS AND OSWEGO COUNTIES WHERE THE BAND WILL LIKELY
FALL LONGER.
OFF LAKE ERIE...A WESTERLY FLOW OVER THE STILL OPEN WATERS OF LAKE
ERIE WILL BRING MULTI BANDED STRUCTURE SNOW BANDS ACROSS THE SOUTHERN
TIER. CONFIDENCE IS GREATER ACROSS CHAUTAUQUA AND CATTARAUGUS COUNTIES
THAN SOUTHERN ERIE AND WYOMING COUNTIES FOR WARNING CRITERIA SNOW.
WILL UPGRADE THE WATCH TO A LAKE EFFECT WARNING ACROSS THE SOUTHERN
TIER...WHILE LEAVING ADVISORIES FOR SOUTHERN TIER AND WYOMING
COUNTIES.
3. REGARDING TEMPERATURES...RECORDED HIGHS WERE SHATTERED ACROSS
MUCH OF THE REGION TODAY WITH MORNING AND EARLY AFTERNOON HIGHS
REACHING NEAR 10 DEGREES ABOVE RECORD VALUES FOR THE DATE.
THE NEW RECORDS FOR TODAY...
BUFFALO.....66 (PREVIOUS WAS 56 IN 1916)
ROCHESTER...64 (PREVIOUS WAS 55 IN 1974)
WATERTOWN...63 (PREVIOUS WAS 52 IN 1995)
THESE READINGS ARE STILL SEVERAL DEGREES SHY OF THE ALLTIME
MONTHLY RECORD HIGH TEMPERATURE WHICH ARE AS FOLLOWS:
BUFFALO.....72 IN 1950.
ROCHESTER...74 IN 1950...CORRECTED
WATERTOWN...66 IN 1995.
THE COLD FRONT WILL SWEEP ACROSS THE REGION TONIGHT SENDING
TEMPERATURES BACK TO SEASONAL NORMS...WITH MANY AREAS DOWN INTO THE
UPPER 20S AND LOW 30S BY TOMORROW MORNING. WITH THE RAIN OVERNIGHT
THE PROSPECTS FOR BLACK ICE WILL BE PRESENT AS WE QUICKLY COOL
FURTHER INTO THE MID AND UPPER 20S BY MID MORNING.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
HEAVY LAKE EFFECT SNOWS SHOULD BE ONGOING ON A WESTERLY FLOW
REGIME AT THE START OF THE PERIOD. BUFR PROFILES FROM THURSDAY
NIGHT THROUGH AT LEAST THE DAYTIME HOURS OF FRIDAY CONTINUE TO
LOOK RATHER IMPRESSIVE...AS A DEEP LAYERED CYCLONIC FLOW REGIME IS
WELL ESTABLISHED. MOISTURE PROFILES LOOK QUITE ADEQUATE WITH
SATURATION WELL UP THROUGH 10K FEET AND DEEPER AT TIMES AS A
COUPLE OF REINFORCING WEAK SHORTWAVES WORK THROUGH THE MEAN WEST
NORTHWEST FLOW. THE BIGGEST FACTOR THAT COULD LIMIT TOTALS WILL BE
THE VEERING WINDS IN RESPONSE TO A SHORTWAVE CROSSING THE LOWER
LAKES. THIS WILL TEND TO PUSH THE LAKE BANDS...ESPECIALLY ACROSS
LAKE ONTARIO SOUTHWARD. THIS COULD BRING THE PRIME LAKE EFFECT
FOCUS ALONG THE SOUTH SHORE OF LAKE ONTARIO...WHICH COULD BRING AT
LEAST ADVISORY OR GREATER TOTALS TO THIS AREA INCLUDING THE
ROCHESTER METRO AREA. FEEL A BIT MORE CONFIDENT WITH THE AREA FROM
WAYNE OVER TO NORTHERN CAYUGA AT THIS POINT...THEREFORE WILL ISSUE
A LAKE EFFECT SNOW WATCH FOR THAT AREA...BUT IT IS HIGHLY POSSIBLE
THAT LAKE EFFECT HEADLINES MAY NEED TO BE ISSUED FARTHER TO THE
WEST.
ANOTHER SHORTWAVE APPROACHING THE REGION FRIDAY NIGHT AND SATURDAY
MAY REORIENT THE LAKES SNOWS FOR A TIME NORTHWARD AS THE FLOW
BACKS TO WEST SOUTHWEST...POTENTIALLY BRINGING SOME ACCUMULATING
SNOWS INTO PORTIONS OF THE BUFFALO METRO AND WATERTOWN AREAS. THE
PASSAGE OF THE SHORTWAVE SHOULD RE-ESTABLISH THE LAKE SNOWS BACK
SOUTHWARD LATER SATURDAY AND SATURDAY NIGHT.
MUCH COLDER AIR MASS ACROSS THE AREA FRIDAY AND SATURDAY WITH
DAYTIME HIGHS IN THE TEENS AND 20S...WITH WIND CHILLS PERIODICALLY
BELOW ZERO.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
THE VERY COLD AIR REMAINS IN PLACE SUNDAY...BEFORE A GRADUAL
MODIFICATION OF THE AIR MASS OCCURS INTO EARLY NEXT WEEK AS THE
UPPER TROUGH SHIFTS TO THE EAST. TWO CLIPPER TYPE WAVES LOOK TO
IMPACT THE LOWER LAKES REGION DURING THIS TIME FRAME. ONE WAVE MOVES
THROUGH ON SUNDAY WHICH MAY SERVE TO ENHANCE THE ONGOING LAKE EFFECT
SNOWS IN A WESTERLY FLOW REGIME. THE SECOND WAVE LOOKS TO MOVE
THROUGH LATE MONDAY OR EARLY TUESDAY AND APPEARS TO BE RATHER ROBUST
AND GIVEN THE PROJECTED TRACK OF THE ASSOCIATED SURFACE LOW COULD
BRING THE POTENTIAL FOR A GENERAL WIDESPREAD SEVERAL INCHES OF SNOW.
BEHIND THIS WAKE A COLDER FLOW DEVELOPS WHICH MAY REDEVELOP SOME
LAKE SNOWS BUT LACK OF SIGNIFICANT MOISTURE COULD LIMIT SNOWFALL
POTENTIAL.
&&
.AVIATION /04Z THURSDAY THROUGH MONDAY/...
A BROAD AREA OF SHOWERS WILL MOVE INTO THE REGION...BOTH
STREAMING FROM THE SOUTH AND AHEAD OF A COLD FRONT. THIS WILL
BRING A PERIOD OF RAIN TO ALL TAF SITES...BUT WITH THE SOUTHERLY
DOWNSLOPE COMPONENT TO THE FLOW CIGS WILL BE INITIALLY SLOW TO
DROP.
AS THE COLD FRONT CROSS THE AREA BETWEEN 04Z AND 09Z...CIGS WILL
DROP AND IFR CONDITIONS WILL BECOME MORE WIDESPREAD...ESPECIALLY
DOWNWIND OF THE LAKES. RAIN WILL MIX WITH...THEN CHANGE TO SNOW
BEFORE DAYBREAK THURSDAY.
STRONG COLD AIR ADVECTION BEHIND THE DEPARTING FRONT WILL INCREASE
MIXING AND RAPIDLY STRENGTHEN WESTERLY WINDS OVERNIGHT. LATE TONIGHT
INTO THURSDAY MORNING...EXPECT WINDS TO GUST TO 40-50 KNOTS IN MOST
LOCATIONS...BEFORE TAPERING OFF LATE THURSDAY AFTERNOON. LAKE
SNOWS WILL DEVELOP EAST OF THE LAKES. THESE WILL LIKELY STAY OUT
OF BUF/IAG/ROC...BUT SHOULD IMPACT ART/JHW FOR A PERIOD.
CONDITIONS WILL VARY SIGNIFICANTLY IN AND OUT OF LAKE EFFECT BANDS.
OUTLOOK...
THURSDAY NIGHT THROUGH SATURDAY...MVFR WITH LOCALIZED IFR IN LAKE
EFFECT SNOW EAST OF THE LAKES.
SUNDAY...MAINLY VFR WITH MVFR IN LOCALIZED LAKE EFFECT SNOW SHOWERS.
MONDAY...VFR.
&&
.MARINE...
A COMPLEX AREA OF LOW PRESSURE FROM SOUTHERN CANADA AND THROUGH THE
CENTRAL GREAT LAKES REGION THIS AFTERNOON WILL LIFT NORTHEASTWARD
AND DEEPEN TONIGHT AND TOMORROW. A COLD FRONT SWINGING ACROSS THE
LAKES...COUPLED WITH STRONG COLD AIR ADVECTION AND RAPID DEEPENING
OF THE SURFACE LOW WILL INCREASE WINDS QUICKLY TO GALE FORCE
FOLLOWING THE PASSAGE OF THE FRONT TONIGHT...WITH GALES THEN
CONTINUING THROUGH MUCH OF THURSDAY. FOR THIS REASON...GALE WARNINGS
WILL CONTINUE AS OUTLINED ON THE LAKES. WINDS AND WAVES WILL STILL
REMAIN STRONG THURSDAY EVENING THROUGH SATURDAY...BEFORE DIMINISHING
TO BELOW SMALL CRAFT CONDITIONS BY SATURDAY NIGHT.
&&
.HYDROLOGY...
FOLLOWING A BLEND OF RADAR AND NEAR TERM GUIDANCE...IT APPEARS THE
STEADIEST RAINS WILL FALL EAST OF LAKE ONTARIO...WITH LESSER
AMOUNTS WEST OF THE GENESEE RIVER. EAST OF LAKE ONTARIO...EXPECT
AROUND AN INCH OF RAIN TO FALL...WITH LESS THAN THAT WEST OF THE
GENESEE. LATEST RFC FORECASTS HAVE LOWERED CRESTS AT
WELLSVILLE...WITH THE MAJORITY OF MMEFS GUIDANCE KEEPING THE
BUFFALO CREEKS...GENESEE RIVER...AND ALLEGHENY RIVER BELOW FLOOD
STAGE. THERE STILL MAY BE A FEW LINGERING ICE JAMS IN TYPICALLY
FLOOD PRONE AREAS IN PARTS OF CHAUTAUQUA COUNTY.
THERE STILL A THREAT FOR FLOODING IN EASTERN PORTIONS...WHERE AN
INCH OF RAINFALL STILL APPEARS LIKELY. LOCALLY HIGHER AMOUNTS FROM
CONVECTION AND/OR UPSLOPING MAY ALSO OCCUR. THIS COMBINED WITH
SNOW MELT FROM LOCATIONS EAST OF LAKE ONTARIO WILL RESULT IN
SIGNIFICANT RISES IN THE RIVERS AND CREEKS. AN INCH OF RAIN IS
STILL MARGINAL TO CAUSE FLOODING...BUT WITH SNOW MELT QUITE
DIFFICULT TO FORECAST...AND SOME ICE JAMS POSSIBLE...THERE IS A
CONTINUED RISK OF FLOODING. THE SREF AND TO A LESSER EXTENT GFS/GGEM
BASED MMEFS ENSEMBLES POINT TO THIS POTENTIAL.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...HIGH WIND WARNING UNTIL 4 PM EST THURSDAY FOR NYZ001>008-010-
011-019-020-085.
LAKE EFFECT SNOW ADVISORY FROM 10 AM THURSDAY TO 6 PM EST
FRIDAY FOR NYZ012-085.
LAKE EFFECT SNOW ADVISORY FROM 10 AM THURSDAY TO 1 AM EST
FRIDAY FOR NYZ007.
FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR NYZ004>008-014.
LAKE EFFECT SNOW WARNING FROM 10 AM THURSDAY TO 6 PM EST
FRIDAY FOR NYZ006-008-019-020.
LAKE EFFECT SNOW WATCH FROM THURSDAY EVENING THROUGH FRIDAY
AFTERNOON FOR NYZ004-005.
WIND ADVISORY UNTIL 4 PM EST THURSDAY FOR NYZ012>014-021.
MARINE...GALE WARNING UNTIL 4 PM EST THURSDAY FOR LEZ040-041.
GALE WARNING UNTIL 10 AM EST THURSDAY FOR LEZ020.
SMALL CRAFT ADVISORY UNTIL 4 PM EST THURSDAY FOR
LOZ030.
GALE WARNING UNTIL 4 PM EST THURSDAY FOR LOZ042>045-
062>065.
&&
$$
SYNOPSIS...THOMAS
NEAR TERM...APFFEL/THOMAS
SHORT TERM...TMA
LONG TERM...TMA
AVIATION...APFFEL
MARINE...APFFEL/THOMAS
HYDROLOGY...APFFEL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1208 PM EST THU JAN 31 2013
.SYNOPSIS...
COOL HIGH PRESSURE WILL BUILD IN FROM THE WEST TODAY...WITH BELOW
NORMAL TEMPERATURES EXPECTED. IT WILL BE BREEZY TODAY... ALTHOUGH
WINDS WILL NOT BE AS STRONG AS LAST NIGHT. A SERIES OF DRY COLD
FRONTS WILL MOVE ACROSS THE AREA. THE FIRST FRONT WILL CROSS THE
AREA FRIDAY FOLLOWED BY ANOTHER ON SUNDAY AND YET ANOTHER ON TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 AM THURSDAY...NO SIGNIFICANT CHANGES HAVE BEEN MADE TO
THE FORECAST. TEMPERATURES ARE SLOW TO RISE AS EXPECTED BUT ARE
FOLLOWING THE HOURLY CURVE DERIVED FROM A NAM/RUC BLEND WITHIN +/-1
DEGREE. NO CHANGES ARE NEEDED. PREVIOUS DISCUSSION FROM 930 AM
FOLLOWS...
THE SEASONS HAVE CHANGED YET AGAIN WITH YESTERDAY`S SPRING-LIKE
WEATHER REPLACED BY A RETURN TO WINTER TODAY. COLD ADVECTION ON
WESTERLY WINDS BEHIND LAST NIGHT`S STRONG COLD FRONT WILL ALMOST
PERFECTLY BALANCE NEARLY FULL SUNSHINE TODAY AND TEMPERATURES WILL
STRUGGLE JUST TO RISE A FEW DEGREES BY AFTERNOON...REACHING 53-56
DEGREES AREAWIDE. THE 12Z GSO SOUNDING WAS BEST SIMULATED BY THE 12Z
NAM AND RUC MODELS...AND THESE ARE THE TWO MODELS I BLENDED FOR MY
UPDATED FORECAST TODAY. DOWNWARD REVISIONS HAVE BEEN MADE TO
DEWPOINT FORECASTS FOR THE AFTERNOON HOURS WITH LOWER 20S DEWPOINTS
EXPECTED TO MIX DOWN FROM A RESERVOIR OF VERY DRY AIR ALOFT.
PRECIPITABLE WATER VALUES TODAY SHOULD RANGE FROM 0.20 TO 0.25
INCHES.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...SHORTWAVE ROUNDING BASE OF MID LEVEL TROUGH
EARLY FRI HELPS DRIVE A REINFORCING SHOT OF COLD AIR INTO THE
REGION. DRY COLD FRONT PUSHES OFFSHORE BY MIDDAY WITH A PERIOD OF
BRIEF BUT STRONG COLD ADVECTION ENDING LATE FRI NIGHT. TEMP DROP
WILL BE SIGNIFICANT WITH GUIDANCE SHOWING 850 TEMPS DECREASING BY
AS MUCH AS 10C IN SOME PLACES IN UNDER 12 HOURS. DEEP WEST TO
NORTHWEST FLOW FRI INTO FRI NIGHT HELPS KEEP SKIES CLEAR. PATTERN
BECOMES LESS AMPLIFIED AND MORE PROGRESSIVE LATE FRI
NIGHT...SHUTTING OFF COLD ADVECTION. MORE PROGRESSIVE EVOLUTION OF
MID LEVEL PATTERN HELPS MOVE CENTER OF SURFACE RIDGE AXIS OVER THE
REGION FOR SAT MORNING...ALLOWING FOR SOME RADIATIONAL COOLING. DO
NOT ANTICIPATE EFFECT TO BE VERY STRONG BUT TYPICAL COLD SPOTS
WILL FLIRT WITH TEENS FOR LOWS. HIGHS FRI WILL STRUGGLE TO REACH
CLIMO WHILE LOWS WILL DROP INTO THE LOW TO MID 20S IN MOST AREAS
SAT MORNING.
SURFACE RIDGE AXIS SHIFTS OFFSHORE SAT WITH WEAK RETURN FLOW SETTING
UP FOR THE END OF THE PERIOD. ALOFT ANOTHER SHORTWAVE HELPS AMPLIFY
THE MID LEVEL PATTERN...RESULTING IN A SHORT PERIOD OF DEEP
WEST-SOUTHWEST FLOW AHEAD OF ANOTHER COLD FRONT MOVING INTO THE
REGION AS THE PERIOD ENDS. ANTICIPATE AN INCREASE IN MID AND
UPPER LEVEL CLOUD ASSOCIATED WITH THIS WAVE BUT DURATION OF RETURN
FLOW IS NOT ENOUGH TO BRING SIGNIFICANT MOISTURE BACK INTO THE
REGION BEFORE THE FRONT PASSES. ALTHOUGH SOME GUIDANCE IS POINTING
TO SOME LIGHT ISOLATED PRECIP EARLY SUN MORNING DO NOT THINK THIS
WILL BE THE CASE. WILL MAINTAIN A POP FORECAST AROUND 10 SAT
NIGHT. TEMPERATURES REMAIN BELOW CLIMO SAT BUT END UP MUCH CLOSER
TO CLIMO SAT NIGHT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 3 AM THURSDAY...A RATHER REPETITIVE PATTERN FOR THE EXTENDED AS
AREAS OF HIGH PRESSURE PUSH OFFSHORE AHEAD OF A SERIES OF WEAK
COLD FRONTS.
FIRST COLD FRONT WILL CROSS THE AREA VERY EARLY SUNDAY MORNING.
LIMITED FORCING COMBINED WITH ONLY MARGINAL PWATS SUGGESTS FROPA
WILL BE DRY...AND ONLY ACT TO REINFORCE THE COOL AIR.
HOWEVER...ANY WEAK CAA REMAINS WELL DISPLACED BEHIND THE
FRONT...SO SUNDAY WILL END UP BEING WARMER THAN
SATURDAY...ALTHOUGH BOTH DAYS WILL BE AROUND TO SLIGHTLY BELOW
CLIMO.
ANOTHER LARGE BUT WEAK AREA OF HIGH PRESSURE BUILDS DOWN FROM THE NW
LATE SUNDAY AND PERSISTS INTO TUESDAY WHILE SLOWLY DRIFTING ACROSS
THE REGION. THIS CONTINUES THE COOL AND DRY WEATHER WITH NEAR TO
SLIGHTLY-BELOW SEASONABLE TEMPS. THIS HIGH PRESSURE THEN DRIFTS
OFFSHORE TUESDAY AHEAD OF ANOTHER COLD FRONT PROGGED TO CROSS THE
AREA LATE IN THE DAY. GUIDANCE SHOWING CONSIDERABLE AMPLITUDE
DIFFERENCES IN THE TROUGH DRIVING THIS FRONT WHICH WILL HAVE
SIGNIFICANT IMPACT ON PRECIP POTENTIAL. FOR NOW WILL KEEP INHERITED
SCHC/SILENT POP FOR D6 SINCE BENEFICIAL CHANGES CANNOT BE MADE AT
THIS TIME. TUESDAY WILL LIKELY BE THE WARMEST DAY OF THE PERIOD
THOUGH AHEAD OF THE COLD FRONT...WITH TEMPS RETURNING TO BELOW CLIMO
FOR WEDNESDAY AS ANOTHER AREA OF HIGH PRESSURE RIDGES DOWN FROM THE
NW.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 18Z...VFR WITH CLEAR SKIES THIS AFTERNOON. A TIGHT PRESSURE
GRADIENT WILL PRODUCE WSW-W WINDS 15-25 KNOTS WITH SPEEDS GRADUALLY
DIMINISHING. VFR THIS EVENING AND OVERNIGHT WITH WSW WINDS 6-12
KNOTS. ANOTHER COLD FRONT WILL TRAVERSE THE TERMINALS AFTER SUNRISE.
MAINLY SCATTERED VFR LEVEL LOW CLOUDS EXPECTED AS WINDS SHIFT TO THE
WNW GUSTING TO AROUND 25 KNOTS.
EXTENDED OUTLOOK...VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM THURSDAY...NO SIGNIFICANT CHANGES HAVE BEEN MADE TO
THE FORECAST. WINDS OUT AT FRYING PAN SHOALS BUOY ARE GUSTING TO 33
KNOTS ON THE LATEST OBSERVATION...AND GUSTS AT THE VARIOUS PIERS AND
BEACH OBSERVATIONS FINALLY ARE BELOW 30 KNOTS. SEAS CONTINUE TO
DIMINISH AS WELL. THE SMALL CRAFT ADVISORY WILL REMAIN POSTED FOR
THE ONGOING WINDS...AND FOR THE ANTICIPATION OF A RENEWED SURGE OF
NORTHWEST WINDS FRIDAY MORNING BEHIND A SECOND COLD FRONT. PREVIOUS
DISCUSSION FROM 930 AM FOLLOWS...
EARLIER BLOWOUT TIDE CONDITIONS HAVE ABATED. WATER LEVELS AS
MEASURED AT THE OFFICIAL NOS (NATIONAL OCEAN SERVICE) TIDE GAUGES
REACHED -1.92 FT MLLW AT WRIGHTSVILLE BEACH... AND -1.50 FT MLLW AT
MYRTLE BEACH. FOR THE NEXT LOW TIDE JUST AFTER 4 PM...WESTERLY WINDS
SHOULD BE DIMINISHING WITH LESS IMPACT ON COASTAL WATER LEVELS.
OTHERWISE...WEST WINDS AROUND 30 KNOTS WITH FREQUENT GALE-FORCE
GUSTS ARE STILL OCCURRING ACROSS THE AREA THIS MORNING. I WISH THE
GALE WARNING WERE STILL UP AS GUSTS AT THE FRYING PAN SHOALS BUOY
CONTINUE TO ECLIPSE 40 KNOTS...AND WITH 12 FOOT SEAS I AM FAIRLY
CERTAIN SUSTAINED GALE-FORCE WINDS ARE OCCURRING BEYOND 15 MILES
FROM SHORE. THESE VERY STRONG WINDS SHOULD BEGIN TO ABATE OVER THE
NEXT 2 HOURS AS HIGH PRESSURE OVER SOUTHERN LOUISIANA NOSES TOWARD
THE CAROLINAS AND OUR PRESSURE GRADIENT BEGINS TO WEAKEN.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...SMALL CRAFT ADVISORY CONTINUES INTO FRI BEFORE
PASSAGE OF COLD FRONT AND DEVELOPMENT OF OFFSHORE FLOW PUSHES 6
FT SEAS BEYOND 20 NM. STRONG BUT BRIEF COLD ADVECTION DURING THE
SECOND HALF OF FRI INTO FRI NIGHT MAY REQUIRE A PERIOD OF SCEC
HEADLINES. HIGH PRESSURE BUILDS IN FROM THE WEST LATE FRI NIGHT
THEN SHIFTS OVER THE WATERS DURING SAT. WEAKENING GRADIENT ALLOWS
WIND SPEEDS TO DROP FROM A SOLID 20 KT FRI TO UNDER 10 KT BY SAT
MORNING. RETURN FLOW STARTS TO DEVELOPING SAT AFTERNOON AS HIGH
PRESSURE SLIDES EAST OF THE WATERS. GRADIENT BECOMES PINCHED AHEAD
OF NEXT COLD FRONT...WITH SOUTHWEST WINDS INCREASING TO 15 KT AS
THE PERIOD ENDS. SEAS SUBSIDE DURING FRI...DROPPING FROM 4 TO 7 FT
AT THE START OF THE PERIOD TO 3 TO 4 FT FRI EVENING. SEAS FALL
FURTHER...CLOSE TO 2 FT...EARLY SAT BEFORE STARTING TO BUILD BACK
CLOSER TO 3 TO 4 FT LATE IN THE PERIOD AS SOUTHWEST WINDS
INCREASE.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 AM THURSDAY...A COLD FRONT WILL CROSS THE WATERS SUNDAY...
TURNING WINDS TO THE W/NW AT 10-15 KTS ON SUNDAY BEFORE SLOWLY
EASING TO LIGHT AND VARIABLE AGAIN MONDAY AS HIGH PRESSURE BUILDS
BACK OVER THE WATERS. SEAS WILL BE PRIMARILY WIND-DRIVEN THROUGH
THE PERIOD...INCREASING FOR A SHORT TIME SUNDAY UP TO 2-4 FT...
THEN DECREASING TO 1 TO 2 FT MONDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST FRIDAY FOR
AMZ250-252-254-256.
&&
$$
NEAR TERM...TRA
SHORT TERM...III
LONG TERM...JDW
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
937 AM EST THU JAN 31 2013
.SYNOPSIS...
COOL HIGH PRESSURE WILL BUILD IN FROM THE WEST TODAY...WITH BELOW
NORMAL TEMPERATURES EXPECTED. IT WILL BE BREEZY TODAY... ALTHOUGH
WINDS WILL NOT BE AS STRONG AS LAST NIGHT. A SERIES OF DRY COLD
FRONTS WILL MOVE ACROSS THE AREA. THE FIRST FRONT WILL CROSS THE
AREA FRIDAY FOLLOWED BY ANOTHER ON SUNDAY AND YET ANOTHER ON TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM THURSDAY...THE SEASONS HAVE CHANGED YET AGAIN WITH
YESTERDAY`S SPRING-LIKE WEATHER REPLACED BY A RETURN TO WINTER
TODAY. COLD ADVECTION ON WESTERLY WINDS BEHIND LAST NIGHT`S STRONG
COLD FRONT WILL ALMOST PERFECTLY BALANCE NEARLY FULL SUNSHINE TODAY
AND TEMPERATURES WILL STRUGGLE JUST TO RISE A FEW DEGREES BY
AFTERNOON...REACHING 53-56 DEGREES AREAWIDE. THE 12Z GSO SOUNDING
WAS BEST SIMULATED BY THE 12Z NAM AND RUC MODELS...AND THESE ARE THE
TWO MODELS I BLENDED FOR MY UPDATED FORECAST TODAY. DOWNWARD
REVISIONS HAVE BEEN MADE TO DEWPOINT FORECASTS FOR THE AFTERNOON
HOURS WITH LOWER 20S DEWPOINTS EXPECTED TO MIX DOWN FROM A RESERVOIR
OF VERY DRY AIR ALOFT. PRECIPITABLE WATER VALUES TODAY SHOULD RANGE
FROM 0.20 TO 0.25 INCHES.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...SHORTWAVE ROUNDING BASE OF MID LEVEL TROUGH
EARLY FRI HELPS DRIVE A REINFORCING SHOT OF COLD AIR INTO THE
REGION. DRY COLD FRONT PUSHES OFFSHORE BY MIDDAY WITH A PERIOD OF
BRIEF BUT STRONG COLD ADVECTION ENDING LATE FRI NIGHT. TEMP DROP
WILL BE SIGNIFICANT WITH GUIDANCE SHOWING 850 TEMPS DECREASING BY
AS MUCH AS 10C IN SOME PLACES IN UNDER 12 HOURS. DEEP WEST TO
NORTHWEST FLOW FRI INTO FRI NIGHT HELPS KEEP SKIES CLEAR. PATTERN
BECOMES LESS AMPLIFIED AND MORE PROGRESSIVE LATE FRI
NIGHT...SHUTTING OFF COLD ADVECTION. MORE PROGRESSIVE EVOLUTION OF
MID LEVEL PATTERN HELPS MOVE CENTER OF SURFACE RIDGE AXIS OVER THE
REGION FOR SAT MORNING...ALLOWING FOR SOME RADIATIONAL COOLING. DO
NOT ANTICIPATE EFFECT TO BE VERY STRONG BUT TYPICAL COLD SPOTS
WILL FLIRT WITH TEENS FOR LOWS. HIGHS FRI WILL STRUGGLE TO REACH
CLIMO WHILE LOWS WILL DROP INTO THE LOW TO MID 20S IN MOST AREAS
SAT MORNING.
SURFACE RIDGE AXIS SHIFTS OFFSHORE SAT WITH WEAK RETURN FLOW SETTING
UP FOR THE END OF THE PERIOD. ALOFT ANOTHER SHORTWAVE HELPS AMPLIFY
THE MID LEVEL PATTERN...RESULTING IN A SHORT PERIOD OF DEEP
WEST-SOUTHWEST FLOW AHEAD OF ANOTHER COLD FRONT MOVING INTO THE
REGION AS THE PERIOD ENDS. ANTICIPATE AN INCREASE IN MID AND
UPPER LEVEL CLOUD ASSOCIATED WITH THIS WAVE BUT DURATION OF RETURN
FLOW IS NOT ENOUGH TO BRING SIGNIFICANT MOISTURE BACK INTO THE
REGION BEFORE THE FRONT PASSES. ALTHOUGH SOME GUIDANCE IS POINTING
TO SOME LIGHT ISOLATED PRECIP EARLY SUN MORNING DO NOT THINK THIS
WILL BE THE CASE. WILL MAINTAIN A POP FORECAST AROUND 10 SAT
NIGHT. TEMPERATURES REMAIN BELOW CLIMO SAT BUT END UP MUCH CLOSER
TO CLIMO SAT NIGHT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 3 AM THURSDAY...A RATHER REPETITIVE PATTERN FOR THE EXTENDED AS
AREAS OF HIGH PRESSURE PUSH OFFSHORE AHEAD OF A SERIES OF WEAK
COLD FRONTS.
FIRST COLD FRONT WILL CROSS THE AREA VERY EARLY SUNDAY MORNING.
LIMITED FORCING COMBINED WITH ONLY MARGINAL PWATS SUGGESTS FROPA
WILL BE DRY...AND ONLY ACT TO REINFORCE THE COOL AIR.
HOWEVER...ANY WEAK CAA REMAINS WELL DISPLACED BEHIND THE
FRONT...SO SUNDAY WILL END UP BEING WARMER THAN
SATURDAY...ALTHOUGH BOTH DAYS WILL BE AROUND TO SLIGHTLY BELOW
CLIMO.
ANOTHER LARGE BUT WEAK AREA OF HIGH PRESSURE BUILDS DOWN FROM THE NW
LATE SUNDAY AND PERSISTS INTO TUESDAY WHILE SLOWLY DRIFTING ACROSS
THE REGION. THIS CONTINUES THE COOL AND DRY WEATHER WITH NEAR TO
SLIGHTLY-BELOW SEASONABLE TEMPS. THIS HIGH PRESSURE THEN DRIFTS
OFFSHORE TUESDAY AHEAD OF ANOTHER COLD FRONT PROGGED TO CROSS THE
AREA LATE IN THE DAY. GUIDANCE SHOWING CONSIDERABLE AMPLITUDE
DIFFERENCES IN THE TROUGH DRIVING THIS FRONT WHICH WILL HAVE
SIGNIFICANT IMPACT ON PRECIP POTENTIAL. FOR NOW WILL KEEP INHERITED
SCHC/SILENT POP FOR D6 SINCE BENEFICIAL CHANGES CANNOT BE MADE AT
THIS TIME. TUESDAY WILL LIKELY BE THE WARMEST DAY OF THE PERIOD
THOUGH AHEAD OF THE COLD FRONT...WITH TEMPS RETURNING TO BELOW CLIMO
FOR WEDNESDAY AS ANOTHER AREA OF HIGH PRESSURE RIDGES DOWN FROM THE
NW.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 12Z...SCATTERED TO BROKEN MVFR LEVEL CLOUDS TRAVERSING
MAINLY THE KILM TERMINAL WILL SHIFT QUICKLY OFFSHORE 13-14Z.
SCATTERED TO BROKEN VFR LEVEL LOW CLOUDS WILL LIKELY PERSIST AT
LEAST THROUGH THE EARLY MORNING HOURS FROM KLBT/KILM NORTH.
SIGNIFICANT DRYING OF THE AIRMASS SHOULD LEAD TO GENERALLY CLEAR
SKIES AT ALL TERMINALS BY LATE MORNING. A TIGHT PRESSURE GRADIENT
WILL PRODUCE WSW-W WINDS 15-25 KNOTS WITH ISOLATED GUSTS 30-35
KNOTS EARLY THIS MORNING. WIND SPEEDS WILL GRADUALLY EASE THROUGH
THE DAY. WILL NOT INCLUDE WIND SHEAR IN TAFS THIS MORNING AS KLTX
WIND PROFILE DATA AND SURFACE REPORTS SUGGESTS WIND SPEEDS ARE
GRADUALLY INCREASING SFC-2K. VFR THIS EVENING AND OVERNIGHT WITH
WSW WINDS 6-12 KNOTS.
EXTENDED OUTLOOK...VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM THURSDAY...EARLIER BLOWOUT TIDE CONDITIONS HAVE ABATED.
WATER LEVELS AS MEASURED AT THE OFFICIAL NOS (NATIONAL OCEAN
SERVICE) TIDE GAUGES REACHED -1.92 FT MLLW AT WRIGHTSVILLE BEACH...
AND -1.50 FT MLLW AT MYRTLE BEACH. FOR THE NEXT LOW TIDE JUST AFTER
4 PM...WESTERLY WINDS SHOULD BE DIMINISHING WITH LESS IMPACT ON
COASTAL WATER LEVELS. OTHERWISE...WEST WINDS AROUND 30 KNOTS WITH
FREQUENT GALE-FORCE GUSTS ARE STILL OCCURRING ACROSS THE AREA THIS
MORNING. I WISH THE GALE WARNING WERE STILL UP AS GUSTS AT THE
FRYING PAN SHOALS BUOY CONTINUE TO ECLIPSE 40 KNOTS...AND WITH 12
FOOT SEAS I AM FAIRLY CERTAIN SUSTAINED GALE-FORCE WINDS ARE
OCCURRING BEYOND 15 MILES FROM SHORE. THESE VERY STRONG WINDS SHOULD
BEGIN TO ABATE OVER THE NEXT 2 HOURS AS HIGH PRESSURE OVER SOUTHERN
LOUISIANA NOSES TOWARD THE CAROLINAS AND OUR PRESSURE GRADIENT
BEGINS TO WEAKEN.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...SMALL CRAFT ADVISORY CONTINUES INTO FRI BEFORE
PASSAGE OF COLD FRONT AND DEVELOPMENT OF OFFSHORE FLOW PUSHES 6
FT SEAS BEYOND 20 NM. STRONG BUT BRIEF COLD ADVECTION DURING THE
SECOND HALF OF FRI INTO FRI NIGHT MAY REQUIRE A PERIOD OF SCEC
HEADLINES. HIGH PRESSURE BUILDS IN FROM THE WEST LATE FRI NIGHT
THEN SHIFTS OVER THE WATERS DURING SAT. WEAKENING GRADIENT ALLOWS
WIND SPEEDS TO DROP FROM A SOLID 20 KT FRI TO UNDER 10 KT BY SAT
MORNING. RETURN FLOW STARTS TO DEVELOPING SAT AFTERNOON AS HIGH
PRESSURE SLIDES EAST OF THE WATERS. GRADIENT BECOMES PINCHED AHEAD
OF NEXT COLD FRONT...WITH SOUTHWEST WINDS INCREASING TO 15 KT AS
THE PERIOD ENDS. SEAS SUBSIDE DURING FRI...DROPPING FROM 4 TO 7 FT
AT THE START OF THE PERIOD TO 3 TO 4 FT FRI EVENING. SEAS FALL
FURTHER...CLOSE TO 2 FT...EARLY SAT BEFORE STARTING TO BUILD BACK
CLOSER TO 3 TO 4 FT LATE IN THE PERIOD AS SOUTHWEST WINDS
INCREASE.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 AM THURSDAY...A COLD FRONT WILL CROSS THE WATERS SUNDAY...
TURNING WINDS TO THE W/NW AT 10-15 KTS ON SUNDAY BEFORE SLOWLY
EASING TO LIGHT AND VARIABLE AGAIN MONDAY AS HIGH PRESSURE BUILDS
BACK OVER THE WATERS. SEAS WILL BE PRIMARILY WIND-DRIVEN THROUGH
THE PERIOD...INCREASING FOR A SHORT TIME SUNDAY UP TO 2-4 FT...
THEN DECREASING TO 1 TO 2 FT MONDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST FRIDAY FOR
AMZ250-252-254-256.
&&
$$
NEAR TERM...TRA
SHORT TERM...III
LONG TERM...JDW
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
650 AM EST THU JAN 31 2013
.SYNOPSIS...
A STRONG COLD FRONT WILL CROSS THE STATE EARLY THIS MORNING....
FOLLOWED BY COLDER AND DRIER AIR TODAY. A WEAK AND MOSTLY DRY COLD
FRONT SYSTEM WILL CROSS THE AREA EARLY FRIDAY WITH HIGH PRESSURE
BUILDING BACK IN FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 600 AM THURSDAY...
SQUALL LINE HAS PUSHES EAST OF THE CWA AND TO TORNADO WATCH WAS
ALLOWED TO EXPIRE AT 2AM. WINDS IMMEDIATELY BEHIND THE LINE
CONTINUE TO GUST TO 30-35KT...BUT DIE OFF WITH WESTWARD EXTENT AWAY
FROM THE LINE. THE IS AN AREA OF STRONGER GUSTS OVER NORTHERN GA
AND WESTERN SC...BUT HRRR WIND GUST FIELDS SUGGEST THESE WINDS WILL
SHIFT EAST ACROSS SC. THUS...WE WILL ALLOW THE WIND ADVISORY TO
EXPIRE AT 4AM.
THE COLD FRONT...CURRENTLY EMERGING EAST OF THE MOUNTAINS..WILL PUSH
EAST ACROSS THE CWA THIS MORNING AND IN TO THE COASTAL PLAIN BY
12Z. EXPECT WINDS WILL GUST PERIODICALLY TO AROUND 20KT WITH THE
FRONT...THEN BECOME MORE CONSISTENT IN THE 20-25KT RANGE OUT OF THE
WEST BEHIND THE FRONT TODAY. A FEW SHOWERS ARE POSSIBLE ALONG THE
FRONT...MAINLY NORTH...AND DRYING ALOFT SHOULD LIMIT COVERAGE IN THE
SOUTH. DESPITE CLEARING BEHIND THE FRONT...MODEST COLD ADVECTION
WILL DOMINATE THE FIRST HALF OF THE DAY... KEEPING TEMPS FROM RISING
MORE THAN 4-6 DEGREES ON MOST PLACES...RANGING FROM THE MID 40S
NORTHWEST TO LOWER 50S SOUTHEAST.
ANOTHER SHORTWAVE TROUGH DIGGING SOUTHEAST OUT OF CANADA WILL SWING
ACROSS THE MID ATLANTIC STATES LATE TONIGHT. STRENGTHENING DPVA AND
A BRIEF SHOT OF 60-80M HEIGHT FALLS FOCUSED ALONG THE NC/VA BORDER
AND NORTHWARD...COMBINED WITH A BAND OF MID LEVEL MOISTURE CROSSING
THE MOUNTAINS MAY BE SUFFICIENT TO CAUSE FLURRIES...MAINLY IN THE
09-12Z TIME FRAME. THE GFS HAS THE MOST ABUNDANT MOISTURE IN
GENERAL...WITH MOISTURE REACHING TO -10C IN A BAND THAT SPANS THE
ENTIRE CWA. HOWEVER...MOISTURE WITHIN THE ICE NUCLEATION ZONE IS
ONLY PRESENT NORTH OF I-40 AND MOST PRONOUNCED NEAR THE NC/VA
BORDER. THE LIMITED DURATION OF LIFT AND MOISTURE..AS WELL AS A
RELATIVELY DRY BOUNDARY LAYER AND POTENTIAL FOR SUBLIMATION...WILL
KEEP THIS TO A NO IMPACT EVENT. LOWS IN THE UPPER 20S TO LOWER 30S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 250 AM WEDNESDAY...
FOR FRIDAY/FRIDAY NIGHT: THE RISK OF A QUICK FLURRY OR SPRINKLE IS
LIKELY TO STRETCH PAST SUNRISE FRIDAY AS THE MID LEVEL SHORTWAVE
TROUGH SHIFTS EASTWARD OFF THE MIDATLANTIC COAST AND THE REINFORCING
CLIPPER COLD FRONT MOVES EAST OF CENTRAL NC. THE LOWEST 10 KFT LAYER
DRIES OUT RAPIDLY BY MID MORNING WITH WINDS IN THIS LAYER VEERING TO
NORTHWESTERLY AND STRONG DEEP SUBSIDENCE COMMENCING AS THE 160 KT
UPPER JET CORE SHIFTS FURTHER EAST OFF THE VA/NC COAST. EXPECT
GENERALLY CLEAR SKIES FROM LATE MORNING THROUGH THE DAY WITH A DRY
AND HIGHLY STABLE COLUMN. THE LOW LEVEL THERMAL STRUCTURE MIXING UP
TO ABOUT 800 MB SUPPORTS CHILLY HIGHS FROM 36 NORTH TO 46 NEAR THE
SC BORDER. TEMPS SHOULD DROP OFF QUICKLY AFTER SUNSET FRIDAY EVENING
THEN LEVEL OFF AS WE BEGIN TO SEE INCREASING HIGH AND MID CLOUDS
OVERNIGHT... AS MID LEVEL DPVA AND HEIGHT FALLS ARRIVE AHEAD OF THE
NEXT CLIPPER. BUT THESE CLOUDS SHOULD BE FAIRLY THIN AND GIVEN THE
VERY COLD YUKON ORIGINS OF THIS INCOMING AIR MASS AND THE WINDS
GOING NEARLY CALM AS THE SURFACE RIDGE AXIS SETTLES OVERHEAD...
STILL ANTICIPATE ABNORMALLY COLD LOWS OF 18-24.
FOR SATURDAY/SATURDAY NIGHT: THE NEXT CLIPPER FRONT WILL STRETCH
FROM THE GREAT LAKES ACROSS MO SATURDAY MORNING... WITH AN
ASSOCIATED WEAK WARM FRONT EXTENDING FROM IL TO SC. THE WARM FRONT
WILL SWEEP NORTHEASTWARD THROUGH THE NC SATURDAY AFTERNOON AS THE
SURFACE RIDGE PUSHES OFF THE COAST. CLOUD COVER WILL CONTINUE TO
THICKEN AND LOWER WITH INCREASING MID LEVEL HEIGHT FALLS IN ADVANCE
OF THE MID LEVEL SHORTWAVE TROUGH APPROACHING NC. DESPITE THE
CLOUDS... THE ENSUING SOUTHWEST LOW LEVEL FLOW SHOULD ALLOW
THICKNESSES AND TEMPS TO REBOUND TO JUST SLIGHTLY BELOW NORMAL...
HIGHS OF 45-50. MODELS DEPICT A 35-40 KT LOW LEVEL SOUTHWESTERLY JET
MOVING THROUGH THE REGION LATE SATURDAY AFTERNOON INTO THE
EVENING... COINCIDENT WITH FORECAST SOUNDINGS SHOWING DEEPENING
MOISTURE FROM 850 MB UP BEYOND 500 MB... AND AHEAD OF A MID LEVEL
VORTICITY MAX AND SHORTWAVE TROUGH THAT WILL BE TAKING ON A NEGATIVE
TILT AS IT PASSES THROUGH NC. THE SUBCLOUD LAYER SHOULD REMAIN
FAIRLY DRY HOWEVER... SO MUCH OF WHAT FALLS IS LIKELY TO
EVAPORATE/SUBLIMATE. GIVEN THAT THE WEB BULB PROFILE ON FORECAST
SOUNDINGS SHOULD BE CLOSE TO FREEZING AT THE SURFACE DURING THIS
TIME IN THE NORTHERN FORECAST AREA AND LIKELY JUST ABOVE FREEZING IN
THE SOUTH... A COMBINATION OF LIGHT SPRINKLES OR FLURRIES STILL
APPEARS REASONABLE. INTERESTING TO NOTE ARE THE GFS`S LAPSE RATES
ALOFT WHICH REACH 7.0 C/KM 800-500 MB SATURDAY NIGHT... SUGGESTING
THAT IF DYNAMIC FORCING FOR ASCENT IS STRONG ENOUGH TO AUGMENT
INSTABILITY ALOFT... WE MAY SEE A LIGHTNING STRIKE OR TWO IF THE
GFS`S STRONGER VORTICITY MAX IS CORRECT. AT ANY RATE... WILL LEAVE
IN A LOW CHANCE POP AREAWIDE FOR LATE AFTERNOON WELL INTO THE
NIGHT... BUT AGAIN EXPECT LITTLE MORE THAN TRACE TO A COUPLE OF
HUNDREDTHS OF AN INCH OF LIQUID EQUIVALENT AS THE SURFACE AIR
REMAINS DRY. SKIES SHOULD CLEAR OUT LATE SATURDAY NIGHT WITH NVA IN
THE WAKE OF THE EXITING TROUGH. LOWS 30-35. -GIH
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 315 AM WEDNESDAY...
FOR SUNDAY: ONE LAST SHOT OF POLAR STREAM ENERGY DIVES DOWN THE SW
SIDE OF THE MEAN TROUGH... FROM THE GREAT LAKES THROUGH WV AND
ACROSS DELMARVA WITH A SURFACE CLIPPER COLD FRONT NOT FAR BEHIND. IT
APPEARS THAT THE MID LEVELS WILL HAVE DRIED OUT AND STABILIZED BY
THIS TIME... AND MOISTURE IS UNIMPRESSIVE IN THE SURFACE-BASED MIXED
LAYER AS WELL... SO WILL SHOWS SOME CLOUDS SWEEPING THROUGH THE AREA
BUT WITH NO PRECIP CHANCES. THICKNESSES REMAIN SEASONABLE SO EXPECT
HIGHS OF 49-55.
FOR SUNDAY NIGHT THROUGH WEDNESDAY: THE COLD LONGWAVE TROUGH OVER
EASTERN NOAM FINALLY RETREATS NORTHWARD AND WEAKENS WITH RISING
HEIGHTS AND A FLATTENING FLOW OVER OUR REGION LASTING THROUGH MID
WEEK... AS MODIFYING SURFACE HIGH PRESSURE BUILDS IN. THE HIGH IS
INITIALLY CHILLY AND TEMPS MONDAY SHOULD RUN SEVERAL DEGREES BELOW
NORMAL... PARTICULARLY WITH MILKY SUNSHINE TO LIMIT INSOLATION AS
ONE LAST MINOR WAVE AND MID LEVEL SPEED MAX MOVE IN FROM THE WEST.
TEMPS SHOULD THEN RECOVER TO ABOVE NORMAL TUESDAY INTO WEDNESDAY AS
THE SURFACE HIGH QUICKLY MODIFIES AS IT EASES TO OUR SOUTH. THE
GFS/ECMWF BOTH SHOWS THIS HIGH PUSHING SOUTHWARD AND WEAKENING AS A
BACKDOOR FRONT APPROACHES FROM THE NORTH... ALTHOUGH THE ECMWF
SWINGS A POTENT NORTHERN STREAM WAVE THROUGH THE MIDATLANTIC
REGION... AND AS A RESULT HAS A MUCH STRONGER AND FASTER BACKDOOR
FRONT AND A NOTABLE COOLDOWN BY WEDNESDAY. WILL STAY WITH THE LESS
AMPLIFIED ROUTE OF THE GFS AT THIS TIME... AND KEEP TEMPS MILD ON
WEDNESDAY WITH FAIR SKIES. -GIH
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 650 AM THURSDAY...
COLD CURRENTLY PUSHING EAST THROUGH THE AREA WILL FORCE THE
REMAINING SHOWERS AND 3-4K FT CEILINGS BETWEEN KRWI AND KFAY TO MOVE
EAST OF THE AREA. THE STRONGEST WESTERLY WINDS ARE CURRENTLY OVER
THE SOUTHERN PORTIONS OF THE AREA...WHERE 25-30KT GUSTS ARE STILL
BEING REPORTED. THESE WINDS WILL WEAKEN THIS MORNING ONCE THE FRONT
MOVES THROUGH THE AREA. HOWEVER...THE APPROACH OF ANOTHER
DISTURBANCE FROM THE NORTHWEST AND STRENGTHENING LOW LEVEL WINDS
WILL LEAD TO 15-20KT SUSTAINED WESTERLY WINDS WITH GUSTS APPROACHING
30KT POSSIBLE LATER THIS AFTERNOON. WHILE VFR CEILINGS AND VSBYS
WILL PREVAIL...A CROSSWIND MAY CAUSE SOME ADVERSE AVIATION
CONDITIONS FOR SMALLER AIRCRAFT.
LOSS OF HEATING SHOULD ALLOW WINDS TO WEAKEN AFTER 00Z..THOUGH
SPORADIC GUSTS TO AROUND 20KT MAY CONTINUE INTO THE OVERNIGHT
HOURS. MID CLOUDS WILL INCREASE LATE TONIGHT AS THE AFOREMENTIONED
DISTURBANCE NEARS THE AREA.
OUTLOOK...VFR CONDITIONS ARE GENERALLY EXPECTED TO PREVAIL THROUGH
EARLY NEXT WEEK. A DISTURBANCE FORECAST TO CROSS THE AREA
SATURDAY/SATURDAY NIGHT WILL BRING ADDED CLOUD COVER AND THE
POTENTIAL FOR A SHORT PERIOD OF RAIN OR SNOW.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
SYNOPSIS...SMITH
NEAR TERM...SMITH
SHORT TERM...HARTFIELD
LONG TERM...HARTFIELD
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
325 AM EST THU JAN 31 2013
.SYNOPSIS...
A STRONG COLD FRONT WILL CROSS THE STATE EARLY THIS MORNING....
FOLLOWED BY COLDER AND DRIER AIR TODAY. A WEAK AND MOSTLY DRY COLD
FRONT SYSTEM WILL CROSS THE AREA EARLY FRIDAY WITH HIGH PRESSURE
BUILDING BACK IN FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 255 AM THURSDAY...
A WIND ADVISORY REMAINS IN EFFECT ACROSS ALL OF CENTRAL NC THROUGH 4
AM LST.
SQUALL LINE HAS PUSHES EAST OF THE CWA AND TO TORNADO WATCH WAS
ALLOWED TO EXPIRE AT 2AM. WINDS IMMEDIATELY BEHIND THE LINE
CONTINUE TO GUST TO 30-35KT...BUT DIE OFF WITH WESTWARD EXTENT AWAY
FROM THE LINE. THE IS AN AREA OF STRONGER GUSTS OVER NORTHERN GA
AND WESTERN SC...BUT HRRR WIND GUST FIELDS SUGGEST THESE WINDS WILL
SHIFT EAST ACROSS SC. THUS...WE WILL ALLOW THE WIND ADVISORY TO
EXPIRE AT 4AM.
THE COLD FRONT...CURRENTLY EMERGING EAST OF THE MOUNTAINS..WILL PUSH
EAST ACROSS THE CWA THIS MORNING AND IN TO THE COASTAL PLAIN BY
12Z. EXPECT WINDS WILL GUST PERIODICALLY TO AROUND 20KT WITH THE
FRONT...THEN BECOME MORE CONSISTENT IN THE 20-25KT RANGE OUT OF THE
WEST BEHIND THE FRONT TODAY. A FEW SHOWERS ARE POSSIBLE ALONG THE
FRONT...MAINLY NORTH...AND DRYING ALOFT SHOULD LIMIT COVERAGE IN THE
SOUTH. DESPITE CLEARING BEHIND THE FRONT...MODEST COLD ADVECTION
WILL DOMINATE THE FIRST HALF OF THE DAY... KEEPING TEMPS FROM RISING
MORE THAN 4-6 DEGREES ON MOST PLACES...RANGING FROM THE MID 40S
NORTHWEST TO LOWER 50S SOUTHEAST.
ANOTHER SHORTWAVE TROUGH DIGGING SOUTHEAST OUT OF CANADA WILL SWING
ACROSS THE MID ATLANTIC STATES LATE TONIGHT. STRENGTHENING DPVA AND
A BRIEF SHOT OF 60-80M HEIGHT FALLS FOCUSED ALONG THE NC/VA BORDER
AND NORTHWARD...COMBINED WITH A BAND OF MID LEVEL MOISTURE CROSSING
THE MOUNTAINS MAY BE SUFFICIENT TO CAUSE FLURRIES...MAINLY IN THE
09-12Z TIME FRAME. THE GFS HAS THE MOST ABUNDANT MOISTURE IN
GENERAL...WITH MOISTURE REACHING TO -10C IN A BAND THAT SPANS THE
ENTIRE CWA. HOWEVER...MOISTURE WITHIN THE ICE NUCLEATION ZONE IS
ONLY PRESENT NORTH OF I-40 AND MOST PRONOUNCED NEAR THE NC/VA
BORDER. THE LIMITED DURATION OF LIFT AND MOISTURE..AS WELL AS A
RELATIVELY DRY BOUNDARY LAYER AND POTENTIAL FOR SUBLIMATION...WILL
KEEP THIS TO A NO IMPACT EVENT. LOWS IN THE UPPER 20S TO LOWER 30S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 250 AM WEDNESDAY...
FOR FRIDAY/FRIDAY NIGHT: THE RISK OF A QUICK FLURRY OR SPRINKLE IS
LIKELY TO STRETCH PAST SUNRISE FRIDAY AS THE MID LEVEL SHORTWAVE
TROUGH SHIFTS EASTWARD OFF THE MIDATLANTIC COAST AND THE REINFORCING
CLIPPER COLD FRONT MOVES EAST OF CENTRAL NC. THE LOWEST 10 KFT LAYER
DRIES OUT RAPIDLY BY MID MORNING WITH WINDS IN THIS LAYER VEERING TO
NORTHWESTERLY AND STRONG DEEP SUBSIDENCE COMMENCING AS THE 160 KT
UPPER JET CORE SHIFTS FURTHER EAST OFF THE VA/NC COAST. EXPECT
GENERALLY CLEAR SKIES FROM LATE MORNING THROUGH THE DAY WITH A DRY
AND HIGHLY STABLE COLUMN. THE LOW LEVEL THERMAL STRUCTURE MIXING UP
TO ABOUT 800 MB SUPPORTS CHILLY HIGHS FROM 36 NORTH TO 46 NEAR THE
SC BORDER. TEMPS SHOULD DROP OFF QUICKLY AFTER SUNSET FRIDAY EVENING
THEN LEVEL OFF AS WE BEGIN TO SEE INCREASING HIGH AND MID CLOUDS
OVERNIGHT... AS MID LEVEL DPVA AND HEIGHT FALLS ARRIVE AHEAD OF THE
NEXT CLIPPER. BUT THESE CLOUDS SHOULD BE FAIRLY THIN AND GIVEN THE
VERY COLD YUKON ORIGINS OF THIS INCOMING AIR MASS AND THE WINDS
GOING NEARLY CALM AS THE SURFACE RIDGE AXIS SETTLES OVERHEAD...
STILL ANTICIPATE ABNORMALLY COLD LOWS OF 18-24.
FOR SATURDAY/SATURDAY NIGHT: THE NEXT CLIPPER FRONT WILL STRETCH
FROM THE GREAT LAKES ACROSS MO SATURDAY MORNING... WITH AN
ASSOCIATED WEAK WARM FRONT EXTENDING FROM IL TO SC. THE WARM FRONT
WILL SWEEP NORTHEASTWARD THROUGH THE NC SATURDAY AFTERNOON AS THE
SURFACE RIDGE PUSHES OFF THE COAST. CLOUD COVER WILL CONTINUE TO
THICKEN AND LOWER WITH INCREASING MID LEVEL HEIGHT FALLS IN ADVANCE
OF THE MID LEVEL SHORTWAVE TROUGH APPROACHING NC. DESPITE THE
CLOUDS... THE ENSUING SOUTHWEST LOW LEVEL FLOW SHOULD ALLOW
THICKNESSES AND TEMPS TO REBOUND TO JUST SLIGHTLY BELOW NORMAL...
HIGHS OF 45-50. MODELS DEPICT A 35-40 KT LOW LEVEL SOUTHWESTERLY JET
MOVING THROUGH THE REGION LATE SATURDAY AFTERNOON INTO THE
EVENING... COINCIDENT WITH FORECAST SOUNDINGS SHOWING DEEPENING
MOISTURE FROM 850 MB UP BEYOND 500 MB... AND AHEAD OF A MID LEVEL
VORTICITY MAX AND SHORTWAVE TROUGH THAT WILL BE TAKING ON A NEGATIVE
TILT AS IT PASSES THROUGH NC. THE SUBCLOUD LAYER SHOULD REMAIN
FAIRLY DRY HOWEVER... SO MUCH OF WHAT FALLS IS LIKELY TO
EVAPORATE/SUBLIMATE. GIVEN THAT THE WEB BULB PROFILE ON FORECAST
SOUNDINGS SHOULD BE CLOSE TO FREEZING AT THE SURFACE DURING THIS
TIME IN THE NORTHERN FORECAST AREA AND LIKELY JUST ABOVE FREEZING IN
THE SOUTH... A COMBINATION OF LIGHT SPRINKLES OR FLURRIES STILL
APPEARS REASONABLE. INTERESTING TO NOTE ARE THE GFS`S LAPSE RATES
ALOFT WHICH REACH 7.0 C/KM 800-500 MB SATURDAY NIGHT... SUGGESTING
THAT IF DYNAMIC FORCING FOR ASCENT IS STRONG ENOUGH TO AUGMENT
INSTABILITY ALOFT... WE MAY SEE A LIGHTNING STRIKE OR TWO IF THE
GFS`S STRONGER VORTICITY MAX IS CORRECT. AT ANY RATE... WILL LEAVE
IN A LOW CHANCE POP AREAWIDE FOR LATE AFTERNOON WELL INTO THE
NIGHT... BUT AGAIN EXPECT LITTLE MORE THAN TRACE TO A COUPLE OF
HUNDREDTHS OF AN INCH OF LIQUID EQUIVALENT AS THE SURFACE AIR
REMAINS DRY. SKIES SHOULD CLEAR OUT LATE SATURDAY NIGHT WITH NVA IN
THE WAKE OF THE EXITING TROUGH. LOWS 30-35. -GIH
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 315 AM WEDNESDAY...
FOR SUNDAY: ONE LAST SHOT OF POLAR STREAM ENERGY DIVES DOWN THE SW
SIDE OF THE MEAN TROUGH... FROM THE GREAT LAKES THROUGH WV AND
ACROSS DELMARVA WITH A SURFACE CLIPPER COLD FRONT NOT FAR BEHIND. IT
APPEARS THAT THE MID LEVELS WILL HAVE DRIED OUT AND STABILIZED BY
THIS TIME... AND MOISTURE IS UNIMPRESSIVE IN THE SURFACE-BASED MIXED
LAYER AS WELL... SO WILL SHOWS SOME CLOUDS SWEEPING THROUGH THE AREA
BUT WITH NO PRECIP CHANCES. THICKNESSES REMAIN SEASONABLE SO EXPECT
HIGHS OF 49-55.
FOR SUNDAY NIGHT THROUGH WEDNESDAY: THE COLD LONGWAVE TROUGH OVER
EASTERN NOAM FINALLY RETREATS NORTHWARD AND WEAKENS WITH RISING
HEIGHTS AND A FLATTENING FLOW OVER OUR REGION LASTING THROUGH MID
WEEK... AS MODIFYING SURFACE HIGH PRESSURE BUILDS IN. THE HIGH IS
INITIALLY CHILLY AND TEMPS MONDAY SHOULD RUN SEVERAL DEGREES BELOW
NORMAL... PARTICULARLY WITH MILKY SUNSHINE TO LIMIT INSOLATION AS
ONE LAST MINOR WAVE AND MID LEVEL SPEED MAX MOVE IN FROM THE WEST.
TEMPS SHOULD THEN RECOVER TO ABOVE NORMAL TUESDAY INTO WEDNESDAY AS
THE SURFACE HIGH QUICKLY MODIFIES AS IT EASES TO OUR SOUTH. THE
GFS/ECMWF BOTH SHOWS THIS HIGH PUSHING SOUTHWARD AND WEAKENING AS A
BACKDOOR FRONT APPROACHES FROM THE NORTH... ALTHOUGH THE ECMWF
SWINGS A POTENT NORTHERN STREAM WAVE THROUGH THE MIDATLANTIC
REGION... AND AS A RESULT HAS A MUCH STRONGER AND FASTER BACKDOOR
FRONT AND A NOTABLE COOLDOWN BY WEDNESDAY. WILL STAY WITH THE LESS
AMPLIFIED ROUTE OF THE GFS AT THIS TIME... AND KEEP TEMPS MILD ON
WEDNESDAY WITH FAIR SKIES. -GIH
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 1250 AM THURSDAY...
SQUALL LINE CURRENTLY EXTENDS FROM KAVC TO KJNX TO BETWEEN KFAY AND
KCTZ...MOVING EAST AT AROUND 30 MPH. STRONGEST SOUTHERLY WINDS
CONTINUE ALONG AND AHEAD OF THE LINE WHERE 35-40KT GUSTS ARE
REPORTED. HEAVY RAIN AND A SHORT PERIOD OF IFR/LIFR VSBYS AND
CEILINGS WILL OCCUR AT KRWI BETWEEN 06Z AND 07Z. BEHIND THE
LINE...SOUTHWESTERLY WINDS WILL CONTINUE TO GUST TO 25-30KT
IMMEDIATELY BEHIND THE LINE...WITH THE STRONGEST GUSTS LIKELY TO
ACCOMPANY SCATTERED SHOWERS THROUGH 09Z.
THE MAIN COLD FRONT IS CURRENTLY CROSSING THE MOUNTAINS AND WILL
CROSS THE AREAS BY 12Z. WINDS WILL TURN TO MORE WESTERLY WITH THE
FRONT AS CEILINGS AND VSBYS RETURN TO VFR. WHILE THERE MAY BE A
WEAKENING TREND IN WINDS...EXPECT THERE WILL STILL BE SOME SPORADIC
WIND GUSTS THROUGH THE MORNING HOURS...WITH WIDESPREAD WIND GUSTS
TO 20-25KT OUT OF THE WEST DURING THE DAY.
OUTLOOK...VFR CONDITIONS ARE THEN EXPECTED TO PREVAIL THROUGH EARLY
NEXT WEEK. ALTHOUGH...A COUPLE OF COLD FRONTS WILL MOVE ACROSS THE
AREA...ONE FRIDAY MORNING AND ONE SATURDAY NIGHT AND COULD PRODUCE A
PERIOD OF INCREASED CLOUDINESS...WITH EVEN A SMALL POSSIBILITY OF
SOME SPRINKLES OR FLURRIES.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY THROUGH 4 AM EST THIS MORNING FOR
NCZ007>011-021>028-038>043-073>078-083>086-088-089.
&&
$$
SYNOPSIS...CBL/SMITH
NEAR TERM...SMITH
SHORT TERM...HARTFIELD
LONG TERM...HARTFIELD
AVIATION...KRR/SMITH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
308 AM EST THU JAN 31 2013
.SYNOPSIS...
A STRONG COLD FRONT WILL CROSS THE STATE EARLY THIS
MORNING....FOLLOWED BY COLDER AND DRIER AIR TODAY. A WEAK AND MOSTLY
DRY COLD FRONT SYSTEM WILL CROSS THE AREA EARLY FRIDAY WITH HIGH
PRESSURE BUILDING BACK IN FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 255 AM THURSDAY...
...A WIND ADVISORY ALSO REMAINS IN EFFECT ACROSS ALL OF CENTRAL NC
THROUGH 4 AM LST...
SQUALL LINE HAS PUSHES EAST OF THE CWA AND TO TORNADO WATCH WAS
ALLOWED TO EXPIRE AT 2AM. WINDS IMMEDIATELY BEHIND THE LINE
CONTINUE TO GUST TO 30-35KT...BUT DIE OFF WITH WESTWARD EXTENT AWAY
FROM THE LINE. THE IS AN AREA OF STRONGER GUSTS OVER NORTHERN GA
AND WESTERN SC...BUT HRRR WIND GUST FIELDS SUGGEST THESE WINDS WILL
SHIFT EAST ACROSS SC. THUS...WE WILL ALLOW THE WIND ADVISORY TO
EXPIRE AT 4AM.
THE COLD FRONT...CURRENTLY EMERGING EAST OF THE MOUNTAINS..WILL PUSH
EAST ACROSS THE CWA THIS MORNING AND IN TO THE COASTAL PLAIN BY
12Z. EXPECT WINDS WILL GUST PERIODICALLY TO AROUND 20KT WITH THE
FRONT...THEN BECOME MORE CONSISTENT IN THE 20-25KT RANGE OUT OF THE
WEST BEHIND THE FRONT TODAY. A FEW SHOWERS ARE POSSIBLE ALONG THE
FRONT...MAINLY NORTH...AND DRYING ALOFT SHOULD LIMIT COVERAGE IN THE
SOUTH. DESPITE CLEARING BEHIND THE FRONT...MODEST COLD ADVECTION
WILL DOMINATE THE FIRST HALF OF THE DAY... KEEPING TEMPS FROM RISING
MORE THAN 4-6 DEGREES ON MOST PLACES...RANGING FROM THE MID 40S
NORTHWEST TO LOWER 50S SOUTHEAST.
ANOTHER SHORTWAVE TROUGH DIGGING SOUTHEAST OUT OF CANADA WILL SWING
ACROSS THE MID ATLANTIC STATES LATE TONIGHT. STRENGTHENING DPVA AND
A BRIEF SHOT OF 60-80M HEIGHT FALLS FOCUSED ALONG THE NC/VA BORDER
AND NORTHWARD...COMBINED WITH A BAND OF MID LEVEL MOISTURE CROSSING
THE MOUNTAINS MAY BE SUFFICIENT TO CAUSE FLURRIES...MAINLY IN THE
09-12Z TIME FRAME. THE GFS HAS THE MOST ABUNDANT MOISTURE IN
GENERAL...WITH MOISTURE REACHING TO -10C IN A BAND THAT SPANS THE
ENTIRE CWA. HOWEVER...MOISTURE WITHIN THE ICE NUCLEATION ZONE IS
ONLY PRESENT NORTH OF I-40 AND MOST PRONOUNCED NEAR THE NC/VA
BORDER. THE LIMITED DURATION OF LIFT AND MOISTURE..AS WELL AS A
RELATIVELY DRY BOUNDARY LAYER AND POTENTIAL FOR SUBLIMATION...WILL
KEEP THIS TO A NO IMPACT EVENT. LOWS IN THE UPPER 20S TO LOWER 30S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 250 AM WEDNESDAY...
FOR FRIDAY/FRIDAY NIGHT: THE RISK OF A QUICK FLURRY OR SPRINKLE IS
LIKELY TO STRETCH PAST SUNRISE FRIDAY AS THE MID LEVEL SHORTWAVE
TROUGH SHIFTS EASTWARD OFF THE MIDATLANTIC COAST AND THE REINFORCING
CLIPPER COLD FRONT MOVES EAST OF CENTRAL NC. THE LOWEST 10 KFT LAYER
DRIES OUT RAPIDLY BY MID MORNING WITH WINDS IN THIS LAYER VEERING TO
NORTHWESTERLY AND STRONG DEEP SUBSIDENCE COMMENCING AS THE 160 KT
UPPER JET CORE SHIFTS FURTHER EAST OFF THE VA/NC COAST. EXPECT
GENERALLY CLEAR SKIES FROM LATE MORNING THROUGH THE DAY WITH A DRY
AND HIGHLY STABLE COLUMN. THE LOW LEVEL THERMAL STRUCTURE MIXING UP
TO ABOUT 800 MB SUPPORTS CHILLY HIGHS FROM 36 NORTH TO 46 NEAR THE
SC BORDER. TEMPS SHOULD DROP OFF QUICKLY AFTER SUNSET FRIDAY EVENING
THEN LEVEL OFF AS WE BEGIN TO SEE INCREASING HIGH AND MID CLOUDS
OVERNIGHT... AS MID LEVEL DPVA AND HEIGHT FALLS ARRIVE AHEAD OF THE
NEXT CLIPPER. BUT THESE CLOUDS SHOULD BE FAIRLY THIN AND GIVEN THE
VERY COLD YUKON ORIGINS OF THIS INCOMING AIR MASS AND THE WINDS
GOING NEARLY CALM AS THE SURFACE RIDGE AXIS SETTLES OVERHEAD...
STILL ANTICIPATE ABNORMALLY COLD LOWS OF 18-24.
FOR SATURDAY/SATURDAY NIGHT: THE NEXT CLIPPER FRONT WILL STRETCH
FROM THE GREAT LAKES ACROSS MO SATURDAY MORNING... WITH AN
ASSOCIATED WEAK WARM FRONT EXTENDING FROM IL TO SC. THE WARM FRONT
WILL SWEEP NORTHEASTWARD THROUGH THE NC SATURDAY AFTERNOON AS THE
SURFACE RIDGE PUSHES OFF THE COAST. CLOUD COVER WILL CONTINUE TO
THICKEN AND LOWER WITH INCREASING MID LEVEL HEIGHT FALLS IN ADVANCE
OF THE MID LEVEL SHORTWAVE TROUGH APPROACHING NC. DESPITE THE
CLOUDS... THE ENSUING SOUTHWEST LOW LEVEL FLOW SHOULD ALLOW
THICKNESSES AND TEMPS TO REBOUND TO JUST SLIGHTLY BELOW NORMAL...
HIGHS OF 45-50. MODELS DEPICT A 35-40 KT LOW LEVEL SOUTHWESTERLY JET
MOVING THROUGH THE REGION LATE SATURDAY AFTERNOON INTO THE
EVENING... COINCIDENT WITH FORECAST SOUNDINGS SHOWING DEEPENING
MOISTURE FROM 850 MB UP BEYOND 500 MB... AND AHEAD OF A MID LEVEL
VORTICITY MAX AND SHORTWAVE TROUGH THAT WILL BE TAKING ON A NEGATIVE
TILT AS IT PASSES THROUGH NC. THE SUBCLOUD LAYER SHOULD REMAIN
FAIRLY DRY HOWEVER... SO MUCH OF WHAT FALLS IS LIKELY TO
EVAPORATE/SUBLIMATE. GIVEN THAT THE WEB BULB PROFILE ON FORECAST
SOUNDINGS SHOULD BE CLOSE TO FREEZING AT THE SURFACE DURING THIS
TIME IN THE NORTHERN FORECAST AREA AND LIKELY JUST ABOVE FREEZING IN
THE SOUTH... A COMBINATION OF LIGHT SPRINKLES OR FLURRIES STILL
APPEARS REASONABLE. INTERESTING TO NOTE ARE THE GFS`S LAPSE RATES
ALOFT WHICH REACH 7.0 C/KM 800-500 MB SATURDAY NIGHT... SUGGESTING
THAT IF DYNAMIC FORCING FOR ASCENT IS STRONG ENOUGH TO AUGMENT
INSTABILITY ALOFT... WE MAY SEE A LIGHTNING STRIKE OR TWO IF THE
GFS`S STRONGER VORTICITY MAX IS CORRECT. AT ANY RATE... WILL LEAVE
IN A LOW CHANCE POP AREAWIDE FOR LATE AFTERNOON WELL INTO THE
NIGHT... BUT AGAIN EXPECT LITTLE MORE THAN TRACE TO A COUPLE OF
HUNDREDTHS OF AN INCH OF LIQUID EQUIVALENT AS THE SURFACE AIR
REMAINS DRY. SKIES SHOULD CLEAR OUT LATE SATURDAY NIGHT WITH NVA IN
THE WAKE OF THE EXITING TROUGH. LOWS 30-35. -GIH
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 150 PM WEDNESDAY...
THE WARMER START AND INCREASING SUN EXPECTED ON SUNDAY WILL ALLOW
HIGHS TO REBOUND FURTHER...INTO THE SEASONABLE LOWER 50S OVER MOST
OF THE AREA.
THE EAST COAST TROF AXIS SHIFTS OFFSHORE AND UPPER FLOW WILL NOT BE
AS AMPLIFIED EARLY NEXT WEEK. ANOTHER REINFORCING BACKDOOR COLD
FRONT WILL BE SLOWLY EDGING SOUTH AND POTENTIALLY STALLING ACROSS
THE MID ATLANTIC ON TUESDAY INTO WEDNESDAY...BUT MOISTURE WILL BE
LACKING AND FORCING WILL BE UNFOCUSED IN THE WEAKER UPPER FLOW. AT
THIS POINT THE WEATHER MONDAY THROUGH WEDNESDAY LOOKS DRY AND
SEASONABLY MILD WITH HIGHS MOSTLY IN THE LOW TO MID 50S EACH DAY.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 1250 AM THURSDAY...
SQUALL LINE CURRENTLY EXTENDS FROM KAVC TO KJNX TO BETWEEN KFAY AND
KCTZ...MOVING EAST AT AROUND 30 MPH. STRONGEST SOUTHERLY WINDS
CONTINUE ALONG AND AHEAD OF THE LINE WHERE 35-40KT GUSTS ARE
REPORTED. HEAVY RAIN AND A SHORT PERIOD OF IFR/LIFR VSBYS AND
CEILINGS WILL OCCUR AT KRWI BETWEEN 06Z AND 07Z. BEHIND THE
LINE...SOUTHWESTERLY WINDS WILL CONTINUE TO GUST TO 25-30KT
IMMEDIATELY BEHIND THE LINE...WITH THE STRONGEST GUSTS LIKELY TO
ACCOMPANY SCATTERED SHOWERS THROUGH 09Z.
THE MAIN COLD FRONT IS CURRENTLY CROSSING THE MOUNTAINS AND WILL
CROSS THE AREAS BY 12Z. WINDS WILL TURN TO MORE WESTERLY WITH THE
FRONT AS CEILINGS AND VSBYS RETURN TO VFR. WHILE THERE MAY BE A
WEAKENING TREND IN WINDS...EXPECT THERE WILL STILL BE SOME SPORADIC
WIND GUSTS THROUGH THE MORNING HOURS...WITH WIDESPREAD WIND GUSTS
TO 20-25KT OUT OF THE WEST DURING THE DAY.
OUTLOOK...VFR CONDITIONS ARE THEN EXPECTED TO PREVAIL THROUGH EARLY
NEXT WEEK. ALTHOUGH...A COUPLE OF COLD FRONTS WILL MOVE ACROSS THE
AREA...ONE FRIDAY MORNING AND ONE SATURDAY NIGHT AND COULD PRODUCE A
PERIOD OF INCREASED CLOUDINESS...WITH EVEN A SMALL POSSIBILITY OF
SOME SPRINKLES OR FLURRIES.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY THROUGH 4 AM EST THIS MORNING FOR
NCZ007>011-021>028-038>043-073>078-083>086-088-089.
&&
$$
SYNOPSIS...CBL/SMITH
NEAR TERM...SMITH
SHORT TERM...HARTFIELD
LONG TERM...MLM
AVIATION...KRR/SMITH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
305 AM EST THU JAN 31 2013
.SYNOPSIS...
A STRONG COLD FRONT WILL CROSS THE STATE EARLY THIS
MORNING....FOLLOWED BY COLDER AND DRIER AIR TODAY. A WEAK AND MOSTLY
DRY COLD FRONT SYSTEM WILL CROSS THE AREA EARLY FRIDAY WITH HIGH
PRESSURE BUILDING BACK IN FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 255 AM THURSDAY...
...A WIND ADVISORY ALSO REMAINS IN EFFECT ACROSS ALL OF CENTRAL NC
THROUGH 4 AM LST...
SQUALL LINE HAS PUSHES EAST OF THE CWA AND TO TORNADO WATCH WAS
ALLOWED TO EXPIRE AT 2AM. WINDS IMMEDIATELY BEHIND THE LINE
CONTINUE TO GUST TO 30-35KT...BUT DIE OFF WITH WESTWARD EXTENT AWAY
FROM THE LINE. THE IS AN AREA OF STRONGER GUSTS OVER NORTHERN GA
AND WESTERN SC...BUT HRRR WIND GUST FIELDS SUGGEST THESE WINDS WILL
SHIFT EAST ACROSS SC. THUS...WE WILL ALLOW THE WIND ADVISORY TO
EXPIRE AT 4AM.
THE COLD FRONT...CURRENTLY EMERGING EAST OF THE MOUNTAINS..WILL PUSH
EAST ACROSS THE CWA THIS MORNING AND IN TO THE COASTAL PLAIN BY
12Z. EXPECT WINDS WILL GUST PERIODICALLY TO AROUND 20KT WITH THE
FRONT...THEN BECOME MORE CONSISTENT IN THE 20-25KT RANGE OUT OF THE
WEST BEHIND THE FRONT TODAY. A FEW SHOWERS ARE POSSIBLE ALONG THE
FRONT...MAINLY NORTH...AND DRYING ALOFT SHOULD LIMIT COVERAGE IN THE
SOUTH. DESPITE CLEARING BEHIND THE FRONT...MODEST COLD ADVECTION
WILL DOMINATE THE FIRST HALF OF THE DAY... KEEPING TEMPS FROM RISING
MORE THAN 4-6 DEGREES ON MOST PLACES...RANGING FROM THE MID 40S
NORTHWEST TO LOWER 50S SOUTHEAST.
ANOTHER SHORTWAVE TROUGH DIGGING SOUTHEAST OUT OF CANADA WILL SWING
ACROSS THE MID ATLANTIC STATES LATE TONIGHT. STRENGTHENING DPVA AND
A BRIEF SHOT OF 60-80M HEIGHT FALLS FOCUSED ALONG THE NC/VA BORDER
AND NORTHWARD...COMBINED WITH A BAND OF MID LEVEL MOISTURE CROSSING
THE MOUNTAINS MAY BE SUFFICIENT TO CAUSE FLURRIES...MAINLY IN THE
09-12Z TIME FRAME. THE GFS HAS THE MOST ABUNDANT MOISTURE IN
GENERAL...WITH MOISTURE REACHING TO -10C IN A BAND THAT SPANS THE
ENTIRE CWA. HOWEVER...MOISTURE WITHIN THE ICE NUCLEATION ZONE IS
ONLY PRESENT NORTH OF I-40 AND MOST PRONOUNCED NEAR THE NC/VA
BORDER. THE LIMITED DURATION OF LIFT AND MOISTURE..AS WELL AS A
RELATIVELY DRY BOUNDARY LAYER AND POTENTIAL FOR SUBLIMATION...WILL
KEEP THIS TO A NO IMPACT EVENT. LOWS IN THE UPPER 20S TO LOWER 30S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 150 PM WEDNESDAY...
COLD FRONT WILL BE WELL OFFSHORE BY DAYBREAK WITH HIGH PRESSURE
INITIALLY BUILDING ACROSS THE GULF STATES AND INTO THE REGION BEHIND
THE FRONT. MILD ORIGIN OF THE HIGH AND ENSUING WESTERLY FLOW WILL
ALLOW HIGHS ON THURSDAY TO REACH NEAR NORMAL...IN THE UPPER 40S TO
LOWER 50S AND WINDS WILL BE DIMINISHING AS THE PRESSURE GRADIENT
LOOSENS...LOOKING AT UP TO 15 MPH SUSTAINED WESTERLY WINDS WITH
GUSTS TO PERHAPS 25 MPH. A REINFORCING SHORT WAVE WILL BE DIGGING
INTO THE DOMINANT EAST COAST TROF LATE THURSDAY NIGHT...POSSIBLY
SQUEEZING OUT SOME ISOLATED FLURRIES ALONG THE NORTHWEST TIER AS IT
CROSSES THE MOUNTAINS. MINS THURSDAY NIGHT WILL BE AROUND 30...AND
THE MAIN SENSIBLE IMPACT FROM THIS SHORT WAVE WILL BE TO SHARPEN THE
NORTHWEST FLOW INTO THE TROF AND INITIATE STRONGER COLD AIR
ADVECTION ON FRIDAY...WHEN HIGHS WILL STRUGGLE TO GET OUT OF THE
30S IN THE NORTHWEST...AND MAX OUT IN THE MID 40S IN THE
SOUTHEAST. HIGH PRESSURE SETTLING OVERHEAD WILL LOCK THE COLD AIR IN
OVERNIGHT...AND UNDER CLEAR SKIES...MINS FRIDAY NIGHT WILL BOTTOM
OUT IN THE LOWER 20S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 150 PM WEDNESDAY...
MOSTLY CLEAR SKIES WITH HIGH PRESSURE OVERHEAD SATURDAY WILL ALLOW
HIGH TEMPERATURES TO CLIMB BACK TOWARDS SEASONABLE READINGS...IN THE
45 TO 50 DEGREE RANGE. THIS HIGH WILL SHIFT QUICKLY OFFSHORE AND A
FAST MOVING MID LEVEL CLIPPER SYSTEM WILL DIG INTO THE OHIO
VALLEY ON SATURDAY NIGHT...POSSIBLY PRODUCING SOME LIGHT RAIN OR
SNOW SHOWERS AS IT TRAVERSES THE AREA...WITH LITTLE TO NO
ACCUMULATION. THE ASSOCIATED CLOUDINESS WILL PREVENT TEMPERATURES
FROM CRASHING HARD SATURDAY NIGHT...HOWEVER...WITH SUNDAY MORNING
LOWS AROUND 30. THE WARMER START AND INCREASING SUN EXPECTED ON
SUNDAY WILL ALLOW HIGHS TO REBOUND FURTHER...INTO THE SEASONABLE
LOWER 50S OVER MOST OF THE AREA.
THE EAST COAST TROF AXIS SHIFTS OFFSHORE AND UPPER FLOW WILL NOT BE
AS AMPLIFIED EARLY NEXT WEEK. ANOTHER REINFORCING BACKDOOR COLD
FRONT WILL BE SLOWLY EDGING SOUTH AND POTENTIALLY STALLING ACROSS
THE MID ATLANTIC ON TUESDAY INTO WEDNESDAY...BUT MOISTURE WILL BE
LACKING AND FORCING WILL BE UNFOCUSED IN THE WEAKER UPPER FLOW. AT
THIS POINT THE WEATHER MONDAY THROUGH WEDNESDAY LOOKS DRY AND
SEASONABLY MILD WITH HIGHS MOSTLY IN THE LOW TO MID 50S EACH DAY.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 1250 AM THURSDAY...
SQUALL LINE CURRENTLY EXTENDS FROM KAVC TO KJNX TO BETWEEN KFAY AND
KCTZ...MOVING EAST AT AROUND 30 MPH. STRONGEST SOUTHERLY WINDS
CONTINUE ALONG AND AHEAD OF THE LINE WHERE 35-40KT GUSTS ARE
REPORTED. HEAVY RAIN AND A SHORT PERIOD OF IFR/LIFR VSBYS AND
CEILINGS WILL OCCUR AT KRWI BETWEEN 06Z AND 07Z. BEHIND THE
LINE...SOUTHWESTERLY WINDS WILL CONTINUE TO GUST TO 25-30KT
IMMEDIATELY BEHIND THE LINE...WITH THE STRONGEST GUSTS LIKELY TO
ACCOMPANY SCATTERED SHOWERS THROUGH 09Z.
THE MAIN COLD FRONT IS CURRENTLY CROSSING THE MOUNTAINS AND WILL
CROSS THE AREAS BY 12Z. WINDS WILL TURN TO MORE WESTERLY WITH THE
FRONT AS CEILINGS AND VSBYS RETURN TO VFR. WHILE THERE MAY BE A
WEAKENING TREND IN WINDS...EXPECT THERE WILL STILL BE SOME SPORADIC
WIND GUSTS THROUGH THE MORNING HOURS...WITH WIDESPREAD WIND GUSTS
TO 20-25KT OUT OF THE WEST DURING THE DAY.
OUTLOOK...VFR CONDITIONS ARE THEN EXPECTED TO PREVAIL THROUGH EARLY
NEXT WEEK. ALTHOUGH...A COUPLE OF COLD FRONTS WILL MOVE ACROSS THE
AREA...ONE FRIDAY MORNING AND ONE SATURDAY NIGHT AND COULD PRODUCE A
PERIOD OF INCREASED CLOUDINESS...WITH EVEN A SMALL POSSIBILITY OF
SOME SPRINKLES OR FLURRIES.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY THROUGH 4 AM EST THIS MORNING FOR
NCZ007>011-021>028-038>043-073>078-083>086-088-089.
&&
$$
SYNOPSIS...CBL/SMITH
NEAR TERM...SMITH
SHORT TERM...MLM
LONG TERM...MLM
AVIATION...KRR/SMITH
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
115 AM EST THU JAN 31 2013
.SYNOPSIS...
WINDY AND MILD CONDITIONS WILL CONTINUE AHEAD OF A STRONG COLD
FRONT. FAST MOVING SHOWERS AND ISOLATED THUNDERSTORMS TONIGHT
COULD PRODUCE LOCALIZED DAMAGING WIND GUSTS. DRY AND COOL
CONDITIONS WILL FOLLOW THE FRONT THURSDAY THROUGH EARLY NEXT WEEK
AS HIGH PRESSURE MOVES INTO THE REGION.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1045 PM WEDNESDAY...TORNADO WATCH REMAINS IN EFFECT FOR THE
ENTIRE ILM CWA THRU 2 AM. MAIN ADJUSTMENT THIS UPDATE HAS BEEN
APPLIED TO THE TIMING OF THE MAIN LINE OF CONVECTION CROSSING THE
AREA. LATEST KLTX 88D TRENDS...RADAR MOSAIC OF THE SE U.S
TRENDS...AND HRRR MODEL OUTPUT...INDICATE VERY LITTLE CONVECTION TO
DEVELOP AHEAD OF THE APPROACHING LINE. THIS DUE TO A STABLE
SFC BASED MARINE LAYER HAVING PROGRESSED WELL INLAND UNDER THE
STRONG SSE-SSW LOW LEVEL WINDS. AT THIS POINT...DO NOT ANTICIPATE
ANY ROGUE CONVECTIVE CELLS WELL AHEAD OF THIS LINE. HOWEVER...THE
STRONG DYNAMICS ASSOCIATED WITH THE NEARLY SOLID LINE OF THE
CONVECTION ITSELF CONTINUES TO WARRANT THE FORECAST OF STRONG TO
SEVERE CONVECTION...WITH DAMAGING WIND GUSTS THE MAIN CONCERN.
IN ADDITION...AN ISOLATED TORNADO REMAINS POSSIBLE DUE TO
SUPPORTIVE DIRECTIONAL AND SPEED SHEAR ESPECIALLY AT THE LOWER
LEVELS. THIS ILLUSTRATED NICELY BY 00Z UPPER AIR SOUNDING
HODOGRAPHS. CONTINUED TWEAKING NEEDED FOR THE OVERNIGHT TEMP/DEWPT
TRENDS...MAINLY DEALING WITH THE POST FRONTAL AIRMASS ADVECTING
ACROSS THE FA LATE TONIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...STRONG WESTERLY WINDS WILL ADVECT MUCH
COLDER AND DRIER AIR INTO REGION BEHIND EXITING COLD FRONT LOCATED
WELL OFF THE COAST BY THURS MORNING. A VERY BROAD MID TO UPPER
TROUGH WILL SHIFT EAST THROUGH THE PERIOD FINALLY LIFTING OFF TO
THE NORTHEAST BY FRI NIGHT. AS THIS TROUGH MOVES EAST IT WILL
DRIVE A SECONDARY BOUNDARY THROUGH THE AREA BY FRI MORNING. THIS
WILL PROVIDE A REINFORCING SHOT OF COLD AND DRY AIR INTO THE AREA
AS DEEP NW FLOW SETS UP ON FRIDAY.
OVERALL A POTENT STORM SYSTEM WILL LIFT OFF TO THE NORTHEAST AS
HIGH PRESSURE RIDGES UP FROM THE GULF COAST ON THURSDAY...BUT
STRONG HIGH PRESSURE WILL BUILD DOWN FROM CANADA REACHING INTO THE
CENTRAL CONUS BY THURS NIGHT AND SHIFTING EAST OVER THE LOCAL AREA
BY LATE FRI INTO EARLY SAT. THIS WILL MAINTAIN A TIGHTENED
GRADIENT FLOW THROUGH THURS AND THEN WINDS MAY BACK SLIGHTLY
BEFORE NEXT DRY FRONTAL BOUNDARY MOVES THROUGH EARLY FRI WITH A
SPIKE UP OF WINDS BEFORE FINALLY DIMINISHING AND VEERING MORE
NORTH BY FRI NIGHT. THESE STRONG WEST TO NORTHWEST WINDS WILL
MAINTAIN CAA THROUGH MUCH OF THE PERIOD. THERE WILL ONLY BE A
BRIEF PERIOD OF MORE NEUTRAL ADVECTION AHEAD OF DRY COLD FRONT FRI
MORNING. THEREFORE 850 TEMPS DROP FROM 13C JUST AHEAD OF INITIAL
COLD FRONT EARLY THURS MORNING DOWN LESS THAN 0C BY THURS AFTN AND
THEN WILL DROP AN ADDITIONAL SEVERAL DEGREES DOWN TO -8C BY FRI
EVENING. TEMPS REACHING THE MID 50S...ALREADY 20 DEGREES COOLER
THAN ON THURS...WILL HAVE TROUBLE REACHING INTO THE 50S ON FRI AS
COLD ARCTIC HIGH PRESSURE BUILDS DOWN INTO THE AREA. OVERNIGHT
LOWS WILL DROP DOWN TOWARD FREEZING THURS NIGHT IN CAA BUT FRI
NIGHT TEMPS WILL PLUMMET ONCE WINDS DROP OFF IN THE EVENING. A
MUCH MORE IDEAL RADIATIONAL COOLING NIGHT WILL OCCUR ON FRIDAY
NIGHT AS HIGH SHIFTS OVERHEAD...MAKING FOR ONE OF THE COLDEST
NIGHTS OF THE SEASON THUS FAR...WITH WIDESPREAD READINGS IN THE
20S.
DRY AIR WILL RUN SIMILAR TO TEMPS WITH A MAJOR DROP OFF BEHIND
FIRST FRONT AND THEN A PLATEAU AND MINOR INCREASE JUST AHEAD OF
DRY POLAR COLD FRONT FRI MORNING AND THEN ANOTHER NOSE DIVE
THROUGH FRI AFTN. THE PCP WATER DROP OFF FROM 1.6 INCHES VERY
EARLY THURS MORNING DOWN TO A QUARTER OF AN INCH BY LATE THURS
MORNING AND THEN DOWN CLOSE TO A TENTH OF AN INCH BY FRI AFTN.
WITH SUCH A DRY AIR MASS IN PLACE...EXPECT SUNSHINE THROUGH MOST
OF THE PERIOD. MAY SEE SOME CLOUDS WITH LINGERING MOISTURE THROUGH
THURS MORNING AFTER RAINFALL FROM FRONT...AND A SLIGHT SPIKE AHEAD
OF FRONT FRI MORNING.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM WEDNESDAY...A RATHER REPETITIVE PATTERN FOR THE
EXTENDED AS AREAS OF HIGH PRESSURE PUSH OFFSHORE AHEAD OF A SERIES
OF WEAK COLD FRONTS.
FIRST OF THESE OCCURS SATURDAY AS DIFFUSE HIGH PRESSURE MOVES ACROSS
THE AREA AND OFFSHORE...LEAVING A BRIEF PERIOD OF MOIST RETURN FLOW
INTO THE CAROLINAS. THIS IS JUST IN ADVANCE OF A COLD FRONT WHICH
WILL CROSS THE AREA VERY EARLY SUNDAY MORNING. LIMITED FORCING
COMBINED WITH ONLY MARGINAL PWATS SUGGESTS FROPA WILL BE DRY...AND
ONLY ACT TO REINFORCE THE COOL AIR. HOWEVER...ANY WEAK CAA REMAINS
WELL DISPLACED BEHIND THE FRONT...SO SUNDAY WILL END UP BEING WARMER
THAN SATURDAY...ALTHOUGH BOTH DAYS WILL BE AROUND TO SLIGHTLY BELOW
CLIMO.
ANOTHER LARGE BUT WEAK AREA OF HIGH PRESSURE BUILDS DOWN FROM THE NW
LATE SUNDAY AND PERSISTS INTO TUESDAY WHILE SLOWLY DRIFTING ACROSS
THE REGION. THIS CONTINUES THE COOL AND DRY WEATHER WITH NEAR TO
SLIGHTLY-BELOW SEASONABLE TEMPS. THIS HIGH PRESSURE THEN DRIFTS
OFFSHORE TUESDAY AHEAD OF ANOTHER COLD FRONT PROGGED TO CROSS THE
AREA LATE IN THE DAY. GUIDANCE SHOWING CONSIDERABLE AMPLITUDE
DIFFERENCES IN THE TROUGH DRIVING THIS FRONT WHICH WILL HAVE
SIGNIFICANT IMPACT ON PRECIP POTENTIAL. FOR NOW WILL KEEP INHERITED
SCHC/SILENT POP FOR D6 SINCE BENEFICIAL CHANGES CANNOT BE MADE AT
THIS TIME. TUESDAY WILL LIKELY BE THE WARMEST DAY OF THE PERIOD
THOUGH AHEAD OF THE COLD FRONT...WITH TEMPS RETURNING TO BELOW CLIMO
FOR WEDNESDAY AS ANOTHER AREA OF HIGH PRESSURE RIDGES DOWN FROM THE
NW.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 06Z...VFR WITH AREAS OF SHORT-LIVED MVFR/IFR AS SQUALL LINE
WITH SHOWERS/ISOLATED THUNDERSTORMS CONTINUES TO PUSH ACROSS THE
AREA OVER THE NEXT FEW HOURS. VFR EXPECTED THROUGH THE REMAINDER OF
THE VALID TAF PERIOD AFTER 10Z.
MAIN LINE OF SHOWERS IS NOW EAST OF KFLO/KLBT/KMYR...CURRENTLY
AFFECTING KCRE...AND PROGRESSING EASTWARD. EXPECT THIS ACTIVITY TO
REACH KILM WITHIN THE NEXT HOUR...BETWEEN 0645Z AND 0700Z. THIS
SQUALL LINE HAS A HISTORY OF PRODUCING STRONG WINDS WITH SUSTAINED
SPEEDS OF 20+ KTS AND GUSTS UP TO 40+ KTS...ALONG WITH SHORT-LIVED
MVFR/IFR CONDITIONS DUE TO HEAVY RAIN. WITH CURRENT TREND AND
GUIDANCE... EXPECT MAIN SQUALL LINE TO PUSH OFFSHORE BY 0715Z. AFTER
THE PASSAGE OF THE COLD FRONT...THE AREA WILL SEE A SUDDEN WIND
SHIFT...POST-FRONTAL RAIN POTENTIALLY CREATING MVFR/IFR CONDITIONS
OVER THE NEXT FEW HOURS. HAVE INCLUDED LLWS IN CURRENT FCST...AND
HAVE ISSUED AN AWW FOR KILM VALID UNTIL 0730Z FOR THE WINDSHIFT OF
60 DEGREES AND ASSOCIATED GUSTS UP TO 40+ KTS.
CLEARING SKIES WILL LEAD TO VFR CONDITIONS ACROSS THE ENTIRE AREA
BETWEEN 8-10Z. FOR THE REST OF THE PERIOD...EXPECT STRONG WESTERLY
WINDS CONTINUING THROUGH THE AFTERNOON HOURS WITH GUSTS UP TO 25
KTS. GUSTS WILL SUBSIDE INTO THE EVENING HOURS.
EXTENDED OUTLOOK...VFR THROUGH THE EXTENDED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 PM WEDNESDAY...SFC PG WINDS CONTINUE TO OVERSPREAD THE
COASTAL WATERS...WITH WINDS OF 15 TO 30 KT SPEEDS ACROSS THE NEAR
SHORE WATERS DUE TO SSTS IN THE LOW 50S. ACROSS THE OUTER WATERS
OF THE ILM CWA WHERE SSTS INCREASE TO AROUND 60 DEGREES...LOOK
FOR HIGHER WIND SPEEDS OF 25 TO 40 KT. WITH THE INCREASING OF SSE-
SSW WINDS THIS EVENING. ..BUILDING SHORT PERIOD SEAS HAVE FINALLY
RESPONDED. IE. SEAS AT THE OCEAN CREST PIER HAVE NOW CLIMBED TO 7
FT...THE ONSLOW BAY AND FRYING PAN SHOALS BUOYS HAVE CLIMBED TO
12-13 FT RESPECTIVELY...WITH SSTS MEASURED AT BOTH THESE BUOYS OF
60 AND 68 DEGREES RESPECTIVELY. OVERALL...LOOK FOR THIS RANGE OF
WINDS AND SEA CONDITIONS TO PERSIST ACROSS THE FA WATERS UNTIL THE
PASSAGE OF THE COLD FRONT BETWEEN 1 AM AND 5 AM. OVERALL...BUILDING
SIGNIFICANT SEAS HAVE LEVELED OFF FOR THE REMAINDER OF THE
OVERNIGHT...WITH ADJUSTMENTS UPWARDS NEEDED FOR THURSDAY FOR THE
ILM WATERS FROM CAPE FEAR SOUTH TO MURRELLS INLET DUE TO THE
STRONG WSW-W WIND DIRECTIONS KEEPING THE SEAS AGITATED.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...ALTHOUGH SEAS WILL BE ON THE DECREASE
THROUGH MUCH OF THE PERIOD IN STRONG OFF SHORE FLOW...TIGHTENED
GRADIENT FLOW AND COLD SURGE BEHIND FRONT THURS AND AGAIN ON FRI WILL
MAINTAIN SEAS ABOVE SCA THROUGH A GOOD PORTION OF THE SHORT TERM
PERIOD IN THE OUTER WATERS. WESTERLY WINDS UP AROUND 25 KTS WILL
DROP THROUGH THURS ALLOWING OFF SHORE SEAS TO SUBSIDE FROM 8 TO
10 FT FRI MORNING DOWN TO 5 FT BY THURS NIGHT.
WINDS WILL BACK SLIGHTLY TO THE SW THURS NIGHT INTO EARLY FRI
AHEAD OF APPROACHING DRY COLD FRONT BEFORE SPIKING UP IN SURGE
BEHIND FRONT. THIS WILL PRODUCE SEAS AROUND 6 FT ONCE AGAIN FOR A
FEW HOURS ON FRI. THE NEAR SHORE WATERS WILL DECREASE THROUGH
THURS IN OFF SHORE FLOW DOWN TO 2 TO 4 FT AND MAY SPIKE UP A BIT
FRI MORNING BUT OVERALL WILL DROP OFF SOME MORE LATE FRI AS HIGH
PRESSURE SHIFTS OVERHEAD ALLOWING FOR LOCAL SEAS TO DROP TO 2 TO 3 FT
IN ALL WATERS.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 300 PM WEDNESDAY...OTHER THAN A WEAK COLD FRONT
SUNDAY...DIFFUSE HIGH PRESSURE WILL DOMINATE THE WEATHER ACROSS THE
WATERS THROUGH THE EXTENDED. ONE AREA OF HIGH PRESSURE WILL MOVE
ACROSS THE WATERS SATURDAY CREATING LIGHT AND VARIABLE
WINDS...VEERING TO THE SW AND INCREASING TO AROUND 10 KTS LATE IN
THE DAY. THIS AHEAD OF A COLD FRONT WHICH WILL CROSS DURING
SUNDAY...TURNING WINDS TO THE W/NW AT 10-15 KTS ON SUNDAY BEFORE
SLOWLY EASING TO LIGHT AND VARIABLE AGAIN MONDAY AS HIGH PRESSURE
BUILDS BACK OVER THE WATERS. SEAS WILL BE PRIMARILY WIND-DRIVEN
THROUGH THE PERIOD...1-2 FT SATURDAY AND MONDAY...INCREASING FOR A
SHORT TIME SUNDAY UP TO 2-4 FT WITH A NW WIND WAVE DOMINANT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...WIND ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR SCZ017-023-
024-032-033-039-053>056.
NC...WIND ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR NCZ087-096-
099-105>110.
MARINE...GALE WARNING UNTIL 6 AM EST EARLY THIS MORNING FOR AMZ250-252-
254-256.
&&
$$
SYNOPSIS...RGZ
NEAR TERM...DCH
SHORT TERM...RGZ
LONG TERM...JDW
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1119 PM EST WED JAN 30 2013
.SYNOPSIS...
WINDY AND MILD CONDITIONS WILL CONTINUE AHEAD OF A STRONG COLD
FRONT. FAST MOVING SHOWERS AND ISOLATED THUNDERSTORMS TONIGHT
COULD PRODUCE LOCALIZED DAMAGING WIND GUSTS. DRY AND COOL
CONDITIONS WILL FOLLOW THE FRONT THURSDAY THROUGH EARLY NEXT WEEK
AS HIGH PRESSURE MOVES INTO THE REGION.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 1045 PM WEDNESDAY...TORNADO WATCH REMAINS IN EFFECT FOR THE
ENTIRE ILM CWA THRU 2 AM. MAIN ADJUSTMENT THIS UPDATE HAS BEEN
APPLIED TO THE TIMING OF THE MAIN LINE OF CONVECTION CROSSING THE
AREA. LATEST KLTX 88D TRENDS...RADAR MOSAIC OF THE SE U.S
TRENDS...AND HRRR MODEL OUTPUT...INDICATE VERY LITTLE CONVECTION TO
DEVELOP AHEAD OF THE APPROACHING LINE. THIS DUE TO A STABLE
SFC BASED MARINE LAYER HAVING PROGRESSED WELL INLAND UNDER THE
STRONG SSE-SSW LOW LEVEL WINDS. AT THIS POINT...DO NOT ANTICIPATE
ANY ROGUE CONVECTIVE CELLS WELL AHEAD OF THIS LINE. HOWEVER...THE
STRONG DYNAMICS ASSOCIATED WITH THE NEARLY SOLID LINE OF THE
CONVECTION ITSELF CONTINUES TO WARRANT THE FORECAST OF STRONG TO
SEVERE CONVECTION...WITH DAMAGING WIND GUSTS THE MAIN CONCERN.
IN ADDITION...AN ISOLATED TORNADO REMAINS POSSIBLE DUE TO
SUPPORTIVE DIRECTIONAL AND SPEED SHEAR ESPECIALLY AT THE LOWER
LEVELS. THIS ILLUSTRATED NICELY BY 00Z UPPER AIR SOUNDING
HODOGRAPHS. CONTINUED TWEAKING NEEDED FOR THE OVERNIGHT TEMP/DEWPT
TRENDS...MAINLY DEALING WITH THE POST FRONTAL AIRMASS ADVECTING
ACROSS THE FA LATE TONIGHT.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...STRONG WESTERLY WINDS WILL ADVECT MUCH
COLDER AND DRIER AIR INTO REGION BEHIND EXITING COLD FRONT LOCATED
WELL OFF THE COAST BY THURS MORNING. A VERY BROAD MID TO UPPER
TROUGH WILL SHIFT EAST THROUGH THE PERIOD FINALLY LIFTING OFF TO
THE NORTHEAST BY FRI NIGHT. AS THIS TROUGH MOVES EAST IT WILL
DRIVE A SECONDARY BOUNDARY THROUGH THE AREA BY FRI MORNING. THIS
WILL PROVIDE A REINFORCING SHOT OF COLD AND DRY AIR INTO THE AREA
AS DEEP NW FLOW SETS UP ON FRIDAY.
OVERALL A POTENT STORM SYSTEM WILL LIFT OFF TO THE NORTHEAST AS
HIGH PRESSURE RIDGES UP FROM THE GULF COAST ON THURSDAY...BUT
STRONG HIGH PRESSURE WILL BUILD DOWN FROM CANADA REACHING INTO THE
CENTRAL CONUS BY THURS NIGHT AND SHIFTING EAST OVER THE LOCAL AREA
BY LATE FRI INTO EARLY SAT. THIS WILL MAINTAIN A TIGHTENED
GRADIENT FLOW THROUGH THURS AND THEN WINDS MAY BACK SLIGHTLY
BEFORE NEXT DRY FRONTAL BOUNDARY MOVES THROUGH EARLY FRI WITH A
SPIKE UP OF WINDS BEFORE FINALLY DIMINISHING AND VEERING MORE
NORTH BY FRI NIGHT. THESE STRONG WEST TO NORTHWEST WINDS WILL
MAINTAIN CAA THROUGH MUCH OF THE PERIOD. THERE WILL ONLY BE A
BRIEF PERIOD OF MORE NEUTRAL ADVECTION AHEAD OF DRY COLD FRONT FRI
MORNING. THEREFORE 850 TEMPS DROP FROM 13C JUST AHEAD OF INITIAL
COLD FRONT EARLY THURS MORNING DOWN LESS THAN 0C BY THURS AFTN AND
THEN WILL DROP AN ADDITIONAL SEVERAL DEGREES DOWN TO -8C BY FRI
EVENING. TEMPS REACHING THE MID 50S...ALREADY 20 DEGREES COOLER
THAN ON THURS...WILL HAVE TROUBLE REACHING INTO THE 50S ON FRI AS
COLD ARCTIC HIGH PRESSURE BUILDS DOWN INTO THE AREA. OVERNIGHT
LOWS WILL DROP DOWN TOWARD FREEZING THURS NIGHT IN CAA BUT FRI
NIGHT TEMPS WILL PLUMMET ONCE WINDS DROP OFF IN THE EVENING. A
MUCH MORE IDEAL RADIATIONAL COOLING NIGHT WILL OCCUR ON FRIDAY
NIGHT AS HIGH SHIFTS OVERHEAD...MAKING FOR ONE OF THE COLDEST
NIGHTS OF THE SEASON THUS FAR...WITH WIDESPREAD READINGS IN THE
20S.
DRY AIR WILL RUN SIMILAR TO TEMPS WITH A MAJOR DROP OFF BEHIND
FIRST FRONT AND THEN A PLATEAU AND MINOR INCREASE JUST AHEAD OF
DRY POLAR COLD FRONT FRI MORNING AND THEN ANOTHER NOSE DIVE
THROUGH FRI AFTN. THE PCP WATER DROP OFF FROM 1.6 INCHES VERY
EARLY THURS MORNING DOWN TO A QUARTER OF AN INCH BY LATE THURS
MORNING AND THEN DOWN CLOSE TO A TENTH OF AN INCH BY FRI AFTN.
WITH SUCH A DRY AIR MASS IN PLACE...EXPECT SUNSHINE THROUGH MOST
OF THE PERIOD. MAY SEE SOME CLOUDS WITH LINGERING MOISTURE THROUGH
THURS MORNING AFTER RAINFALL FROM FRONT...AND A SLIGHT SPIKE AHEAD
OF FRONT FRI MORNING.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM WEDNESDAY...A RATHER REPETITIVE PATTERN FOR THE
EXTENDED AS AREAS OF HIGH PRESSURE PUSH OFFSHORE AHEAD OF A SERIES
OF WEAK COLD FRONTS.
FIRST OF THESE OCCURS SATURDAY AS DIFFUSE HIGH PRESSURE MOVES ACROSS
THE AREA AND OFFSHORE...LEAVING A BRIEF PERIOD OF MOIST RETURN FLOW
INTO THE CAROLINAS. THIS IS JUST IN ADVANCE OF A COLD FRONT WHICH
WILL CROSS THE AREA VERY EARLY SUNDAY MORNING. LIMITED FORCING
COMBINED WITH ONLY MARGINAL PWATS SUGGESTS FROPA WILL BE DRY...AND
ONLY ACT TO REINFORCE THE COOL AIR. HOWEVER...ANY WEAK CAA REMAINS
WELL DISPLACED BEHIND THE FRONT...SO SUNDAY WILL END UP BEING WARMER
THAN SATURDAY...ALTHOUGH BOTH DAYS WILL BE AROUND TO SLIGHTLY BELOW
CLIMO.
ANOTHER LARGE BUT WEAK AREA OF HIGH PRESSURE BUILDS DOWN FROM THE NW
LATE SUNDAY AND PERSISTS INTO TUESDAY WHILE SLOWLY DRIFTING ACROSS
THE REGION. THIS CONTINUES THE COOL AND DRY WEATHER WITH NEAR TO
SLIGHTLY-BELOW SEASONABLE TEMPS. THIS HIGH PRESSURE THEN DRIFTS
OFFSHORE TUESDAY AHEAD OF ANOTHER COLD FRONT PROGGED TO CROSS THE
AREA LATE IN THE DAY. GUIDANCE SHOWING CONSIDERABLE AMPLITUDE
DIFFERENCES IN THE TROUGH DRIVING THIS FRONT WHICH WILL HAVE
SIGNIFICANT IMPACT ON PRECIP POTENTIAL. FOR NOW WILL KEEP INHERITED
SCHC/SILENT POP FOR D6 SINCE BENEFICIAL CHANGES CANNOT BE MADE AT
THIS TIME. TUESDAY WILL LIKELY BE THE WARMEST DAY OF THE PERIOD
THOUGH AHEAD OF THE COLD FRONT...WITH TEMPS RETURNING TO BELOW CLIMO
FOR WEDNESDAY AS ANOTHER AREA OF HIGH PRESSURE RIDGES DOWN FROM THE
NW.
&&
.AVIATION /04Z THURSDAY THROUGH MONDAY/...
AS OF 00Z...STRONG COLD FRONT TO IMPACT THE TERMINALS TONIGHT WITH
GUSTY WINDS AND A POTENTIAL SQUALL LINE WITH SHOWERS/ISOLATED
THUNDERSTORMS.
COLD FRONT CURRENTLY ACROSS WESTERN PORTIONS OF SC/NC WILL PUSH EAST
TONIGHT AND BE ACCOMPANIED BY A LINE OF SHOWERS WITH ISOLATED
THUNDERSTORMS. HRRR APPEARS TO BE INITIALIZING BETTER THAN ANY OF
THE OTHER HIGH-RES GUIDANCE...SO HAVE RELIED HEAVILY ON THIS MODEL
FOR TIMING CONVECTION AT THE TERMINALS...AND EXPECT THE SQUALL LINE
TO IMPACT FLO/LBT AROUND 03Z...RACING EAST TO ILM AROUND 06Z.
ATTM...NO IFR HAS BEEN INTRODUCED INTO THE CURRENT SET OF TAFS DUE
TO UNCERTAINTY IN EXACT TIMING AND LIKELY SHORT-DURATION OF ANY
PRECIP INDUCED IFR. PREFER TO HANDLE ANY IFR WITH AMD/TEMPO GROUPS
AS THE CONVECTION UNFOLDS. HAVE SHOWN A 2-HR TEMPO GROUP AT ALL
TERMINALS FOR THE HEAVIEST CONVECTION WITH MVFR AND INCREASED WIND
GUSTS...BUT STRONGER GUSTS ARE POSSIBLE THAN WHAT IS CURRENTLY
DEPICTED.
OTHER CONCERN IS THE STRONG PRE-FRONTAL AND POST-FRONTAL WINDS. S/SW
WINDS WILL CONTINUE TO INCREASE TONIGHT AS A STRENGTHENING LOW LEVEL
JET MOVES OVERHEAD. FOR THIS REASON HAVE SHOWN INCREASING LLWS IN
ALL TAFS WITH 30 KT GUSTS LIKELY THROUGH THE NIGHT...EVEN OUTSIDE OF
CONVECTION. A SUDDEN WIND SHIFT WILL OCCUR WITH THE FROPA
TONIGHT...AND AWWS MAY BE REQUIRED FOR ILM/MYR LATER TONIGHT AS THE
FRONT CROSSES...AND WINDS SHIFT SUDDENLY TO THE WEST.
RAPID DRYING OCCURS BEHIND THE FRONT AND SKC WILL BECOME THE SKY
CONDITION ON THURSDAY. ALTHOUGH IT WILL BE CLEAR...STRONG WESTERLY
WINDS WILL PERSIST THROUGH THE DAY...GUSTING TO 25 KTS THROUGH THE
END OF THE VALID PERIOD.
EXTENDED OUTLOOK...VFR THROUGH THE EXTENDED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 PM WEDNESDAY...SFC PG WINDS CONTINUE TO OVERSPREAD THE
COASTAL WATERS...WITH WINDS OF 15 TO 30 KT SPEEDS ACROSS THE NEAR
SHORE WATERS DUE TO SSTS IN THE LOW 50S. ACROSS THE OUTER WATERS
OF THE ILM CWA WHERE SSTS INCREASE TO AROUND 60 DEGREES...LOOK
FOR HIGHER WIND SPEEDS OF 25 TO 40 KT. WITH THE INCREASING OF SSE-
SSW WINDS THIS EVENING. ..BUILDING SHORT PERIOD SEAS HAVE FINALLY
RESPONDED. IE. SEAS AT THE OCEAN CREST PIER HAVE NOW CLIMBED TO 7
FT...THE ONSLOW BAY AND FRYING PAN SHOALS BUOYS HAVE CLIMBED TO
12-13 FT RESPECTIVELY...WITH SSTS MEASURED AT BOTH THESE BUOYS OF
60 AND 68 DEGREES RESPECTIVELY. OVERALL...LOOK FOR THIS RANGE OF
WINDS AND SEA CONDITIONS TO PERSIST ACROSS THE FA WATERS UNTIL THE
PASSAGE OF THE COLD FRONT BETWEEN 1 AM AND 5 AM. OVERALL...BUILDING
SIGNIFICANT SEAS HAVE LEVELED OFF FOR THE REMAINDER OF THE
OVERNIGHT...WITH ADJUSTMENTS UPWARDS NEEDED FOR THURSDAY FOR THE
ILM WATERS FROM CAPE FEAR SOUTH TO MURRELLS INLET DUE TO THE
STRONG WSW-W WIND DIRECTIONS KEEPING THE SEAS AGITATED.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...ALTHOUGH SEAS WILL BE ON THE DECREASE
THROUGH MUCH OF THE PERIOD IN STRONG OFF SHORE FLOW...TIGHTENED
GRADIENT FLOW AND COLD SURGE BEHIND FRONT THURS AND AGAIN ON FRI WILL
MAINTAIN SEAS ABOVE SCA THROUGH A GOOD PORTION OF THE SHORT TERM
PERIOD IN THE OUTER WATERS. WESTERLY WINDS UP AROUND 25 KTS WILL
DROP THROUGH THURS ALLOWING OFF SHORE SEAS TO SUBSIDE FROM 8 TO
10 FT FRI MORNING DOWN TO 5 FT BY THURS NIGHT.
WINDS WILL BACK SLIGHTLY TO THE SW THURS NIGHT INTO EARLY FRI
AHEAD OF APPROACHING DRY COLD FRONT BEFORE SPIKING UP IN SURGE
BEHIND FRONT. THIS WILL PRODUCE SEAS AROUND 6 FT ONCE AGAIN FOR A
FEW HOURS ON FRI. THE NEAR SHORE WATERS WILL DECREASE THROUGH
THURS IN OFF SHORE FLOW DOWN TO 2 TO 4 FT AND MAY SPIKE UP A BIT
FRI MORNING BUT OVERALL WILL DROP OFF SOME MORE LATE FRI AS HIGH
PRESSURE SHIFTS OVERHEAD ALLOWING FOR LOCAL SEAS TO DROP TO 2 TO 3 FT
IN ALL WATERS.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 300 PM WEDNESDAY...OTHER THAN A WEAK COLD FRONT
SUNDAY...DIFFUSE HIGH PRESSURE WILL DOMINATE THE WEATHER ACROSS THE
WATERS THROUGH THE EXTENDED. ONE AREA OF HIGH PRESSURE WILL MOVE
ACROSS THE WATERS SATURDAY CREATING LIGHT AND VARIABLE
WINDS...VEERING TO THE SW AND INCREASING TO AROUND 10 KTS LATE IN
THE DAY. THIS AHEAD OF A COLD FRONT WHICH WILL CROSS DURING
SUNDAY...TURNING WINDS TO THE W/NW AT 10-15 KTS ON SUNDAY BEFORE
SLOWLY EASING TO LIGHT AND VARIABLE AGAIN MONDAY AS HIGH PRESSURE
BUILDS BACK OVER THE WATERS. SEAS WILL BE PRIMARILY WIND-DRIVEN
THROUGH THE PERIOD...1-2 FT SATURDAY AND MONDAY...INCREASING FOR A
SHORT TIME SUNDAY UP TO 2-4 FT WITH A NW WIND WAVE DOMINANT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...WIND ADVISORY UNTIL 6 AM EST THURSDAY FOR SCZ017-023-024-032-
033-039-053>056.
NC...WIND ADVISORY UNTIL 6 AM EST THURSDAY FOR NCZ087-096-099-
105>110.
MARINE...GALE WARNING UNTIL 6 AM EST THURSDAY FOR AMZ250-252-254-256.
&&
$$
SYNOPSIS...RGZ
NEAR TERM...DCH
SHORT TERM...RGZ
LONG TERM...JDW
AVIATION...JDW/SGL
AREA FORECAST DISCUSSION
NWS PORTLAND OR
843 AM PST THU JAN 31 2013
.SYNOPSIS...ONE LAST SYSTEM MOVING OVER THE TOP OF AN OFFSHORE HIGH
PRESSURE WILL BRING SOME LIGHT RAIN TO THE NORTHERN TIER TODAY.
STRENGTHENING HIGH PRESSURE WILL BRING DRY WEATHER FOR AT LEAST
FRIDAY AND SATURDAY...THOUGH THERE WILL BE PLENTY OF LOW CLOUDS AND
FOG ACROSS THE INTERIOR VALLEYS. EAST WINDS WILL INCREASE ACROSS
THE WESTERN COLUMBIA RIVER GORGE LATE FRIDAY LIKELY CAUSING THE
PORTLAND METRO AREA TO CLEAR THOUGH. SYSTEMS LATE THIS WEEKEND AND EARLY
NEXT WEEK APPEAR WEAK...WITH BETTER CHANCES OF PRECIPITATION AROUND
THE MIDDLE OF NEXT WEEK.
&&
.SHORT TERM...DOPPLER RADAR MOSAIC SHOWS A BAND OF LIGHT RAIN MOVING
INTO SOUTHWEST WASHINGTON AND EXTREME NORTHWESTERN OREGON. THIS RAIN
IS ASSOCIATED WITH AN AREA OF ISENTROPIC LIFT ACCOMPANYING A WEAK
FRONT PUSHING SOUTHEASTWARD. AS THIS FRONT DETACHES FROM ITS PARENT
UPPER LEVEL TROUGH OVER BRITISH COLUMBIA...EXPECT IT TO STALL AND
WEAKEN IN THE VICINITY OF THE COLUMBIA RIVER THIS AFTERNOON AND
TONIGHT...AS IT BECOMES ORIENTED MORE LATITUDINALLY.
THE CURRENT PRECIPITATION BAND IS A LITTLE MORE EXTENSIVE AND
ARRIVING EARLIER THAN MOST MODELS WOULD SEEM TO SUGGEST...EVEN THE
SHORT TERM MODELS. THE LATEST HRRR SUGGESTS A SHOWER OR TWO WILL BE
POSSIBLE ACROSS THE PORTLAND METRO AREA LATER THIS AFTERNOON AND
GIVEN THE SOUTHWARD EXTENT OF PRECIPITATION ON RADAR...THIS IDEA
SEEMS PLAUSIBLE. AS A RESULT OF THE ABOVE...POPS WERE INCREASED FOR
TODAY...AND GRIDS WERE SPLIT INTO THREE HOURS TO ATTEMPT TO REFLECT
THE LATEST TIMING AND TRENDS IN RAIN CHANCES.
THE OTHER PROBLEM CHILD THIS MORNING ARE AREAS OF FOG ACROSS THE
PORTLAND METRO AREA. GIVEN PORTIONS OF THE METRO AREA...SUCH AS
DOWNTOWN...REMAIN FOG FREE...WILL CONTINUE TO HANDLE THE FOG PROBLEM
WITH NOWCASTS. GIVEN THE LOW SUN ANGLE AND LIGHT LOW LEVEL FLOW...I
DID EXPAND THE FOG MENTION IN THE GRIDS UNTIL 1 PM AS IT WILL LIKELY
BE SLOW TO LIFT AND MIX OUT.
SKY COVER GRIDS WERE TWEAKED AS WELL FURTHER SOUTH AS AREA CAMS AND THE
FIRST VISIBLE SATELLITE IMAGES OF THE DAY INDICATE MOSTLY SUNNY TO
PARTLY CLOUDY SKIES EXIST ACROSS THE CENTRAL OREGON COAST AND THE
CENTRAL OREGON CASCADES. /NEUMAN
.LONG TERM...SATURDAY NIGHT THROUGH TUESDAY...THE UPPER LEVEL RIDGE
IN PLACE TO START THE WEEKEND BEGINS TO BREAK DOWN SLOWLY TOWARD LATE
SATURDAY AS A WEAK BOUNDARY APPROACHES THE AREA. THIS BOUNDARY WILL
AT THE LEAST BRING INCREASING CLOUDS TO THE AREA BY SUNDAY...BUT IT
WILL BE SHEARING AND SPLITTING...SO EXPECT RAIN CHANCES TO BE ON THE
LOW END. A QUICK MOVING BUT STRONGER FRONTAL SYSTEM WILL THEN
APPROACH THE COAST LATE SUNDAY INTO MONDAY. THIS SYSTEM SEEMS TO
FURTHER BREAK DOWN THE RIDGE...BUT MODELS DISAGREE ON HOW MUCH
MOISTURE IT PUSHES INLAND...BEFORE THE RIDGE REBOUNDS ON MONDAY
AFTERNOON. ANOTHER FRONTAL SYSTEM IS SHOWN TO SWING THROUGH THE AREA
LATER IN THE DAY TUESDAY OR TUESDAY EVENING. A COLD UPPER TROUGH
WILL THEN MOVE THROUGH FOR THE LATTER HALF OF THE WEEK. KMD/BROWN &&
.AVIATION...FLIGHT CONDITIONS REMAIN VARIABLE THIS MORNING...
RANGING ANYWHERE FROM LIFR TO VFR CATEGORY. MOIST LOW LEVELS IN A
LIGHT ONSHORE FLOW ARE LIKELY TO KEEP A VARIETY OF CONDITIONS
ACROSS THE AREA. OVERALL TREND IN THE AFTERNOON IS LIKELY TO BE
FOR SLOW IMPROVEMENT TO PREDOMINANTLY MVFR IN THE NORTH AND AND
VFR CATEGORY IN THE SOUTH. EXPECT A RETURN TO IFR CONDITIONS
ACROSS MUCH OF THE INTERIOR TONIGHT WITH A MIX OF MVFR AND IFR
CONDITIONS ALONG THE COAST.
KPDX AND APPROACHES...IFR AND LIFR CONDITIONS WILL CONTINUE THIS
MORNING. CONDITIONS WILL LIKELY IMPROVE TO MVFR AFTER 20Z TODAY.
IFR CONDITIONS ARE LIKELY TO RE-DEVELOP AFTER 08Z TONIGHT AS THE
AIRMASS STABILIZES.
&&
.MARINE...FAIRLY QUIET NEXT COUPLE OF DAYS AS A HIGH PRES SYSTEM IS
LIKELY TO KEEP WINDS BELOW SMALL CRAFT CRITERIA THROUGH THE WEEKEND.
A LONG PERIOD SWELL OUT OF THE W IS EXPECTED TO BEGIN SHOWING UP
FRI...AND ULTIMATELY RAISE SEAS ABOVE 10 FT ON SAT AND SUN. ALTHOUGH
THE OFFSHORE WAVE HEIGHTS ARE EXPECTED TO PEAK IN THE 10 TO 12 FT
RANGE SAT AND SUN...THE LONG PERIODS MAY PUSH BREAKERS AS HIGH AS
THE 18 TO 20 FT RANGE.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 10 AM
PST THIS MORNING.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 5 PM THIS
AFTERNOON TO 9 PM PST THIS EVENING.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
521 PM CST FRI FEB 1 2013
.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT
345 PM CDT FRI FEB 1 2013
AT 3 PM...THE WATER VAPOR IMAGERY SHOWED A SHORT WAVE TROUGH MOVING
SOUTHEAST THROUGH LAKE WINNIPEG. AT THE THE SURFACE...A COLD
FRONT...LOCATED JUST SOUTH OF LAKE WINNE PEG...WAS PRODUCING SNOW
ACROSS THE EASTERN DAKOTAS...AND NORTHWEST AND WEST CENTRAL
MINNESOTA. THIS SNOW WAS REDUCING VISIBILITIES TO 3/4 MILES AT FARGO
NORTH DAKOTA.
FOR TONIGHT...THE 01.12Z MESO AND DETERMINISTIC MODELS ARE IN GOOD
AGREEMENT THAT SHORT WAVE TROUGH AND COLD FRONT TO OUR NORTHWEST
WILL MOVE SOUTHEAST THROUGH THE FORECAST AREA THIS EVENING AND EARLY
OVERNIGHT. MODERATE 270 TO 280K ISENTROPIC LIFT /2 TO 4
MICROBARS/SEC/ DEVELOPS AHEAD OF THIS SYSTEM. THIS IS BRINGING THE
WARMER AND MORE MOIST /DEW POINTS IN THE LOWER AND MID 20S/ AIR
ALOFT. THIS WARMS THE ATMOSPHERIC COLUMN INTO THE DENDRITIC GROWTH
ZONE AND THE MOISTURE SATURATES IT. 01.09Z SREF SHOWS THAT 50 TO
70 PERCENT OF THE ENSEMBLE FAMILY HAS OVER 200 MB OF DENDRITIC
GROWTH THIS EVENING. THE ROCHESTER RAP BUFKIT SOUNDING SHOWS AT
LEAST 10K FEET IN THE DENDRITIC GROWTH ZONE BETWEEN 02.00Z AND
02.06Z. MEANWHILE THE GFS AND NAM BUFKIT SOUNDINGS HAVE A MUCH
SHORTER TIME. THIS WILL AFFECT THE SNOW RATIOS. THE RAP WOULD
SUGGEST 25-30 TO 1 SNOW TO LIQUID RATIOS. MEANWHILE THE GFS AND NAM
WOULD SUGGEST 17-23 TO 1 SNOW TO LIQUID RATIOS. SINCE THE SYSTEM IS
MOVING SO FAST...TRENDED MORE TOWARD THE GFS AND NAM SOLUTIONS.
THIS WOULD PRODUCE A 1 TO 2 INCH SNOW BAND ACROSS NORTHEAST IOWA AND
AND SOUTHWEST WISCONSIN...AND AROUND AN INCH NORTHWARD TO WISCONSIN
10.
ON SATURDAY AFTERNOON AND NIGHT...ANOTHER SHORT WAVE TROUGH WILL
MOVE SOUTHEAST THROUGH THE REGION. UNLIKE YESTERDAY...HAS THE LEFT
ENTRANCE REGION OF THE 250 MB JET A BIT FURTHER SOUTHEAST. AS A
RESULT...THE OMEGA IS NOT AS STRONG OR DEEP AS IT WAS YESTERDAY.
DESPITE THIS THERE IS MODERATE 270 TO 280K LIFT AHEAD OF THIS WAVE
AND THIS WILL ONCE AGAIN BRING SOME MOISTURE AND WARMER AIR ALOFT
FROM THE NORTHERN AND CENTRAL PLAINS. HOWEVER 01.09Z SREF SHOWS
FEWER MEMBERS HAVING 200 MB OR GREATER OF DENDRITIC GROWTH. THE COBB
DATA SUGGESTS 17-22 TO 1 SNOW TO LIQUID RATIOS. THIS WOULD RESULT IN
AROUND AN INCH OF SNOW FOR MUCH OF THE AREA.
FROM LATE SUNDAY AFTERNOON INTO SUNDAY NIGHT...THE MODELS SHOW YET
ANOTHER SHORT WAVE TROUGH WILL BE MOVING SOUTHEAST THROUGH THE
REGION. BY THIS TIME...THE AIR MASS WILL BE A BIT WARMER. AS A
RESULT...THE BEST ISENTROPIC LIFT IS TAKING PLACE BETWEEN 280 AND
300K. WITH THE AIR MASS WARMER...THERE IS LESS OF A LAYER IN
DENDRITIC GROWTH ZONE. HOWEVER THERE IS A BIT MORE MOISTURE FOR THIS
SYSTEM TO WORK WITH...SO IT LOOKS LIKE SNOW TOTALS WILL RANGE FROM 1
TO 2 INCHES.
OVERALL...IT LOOKS LIKE SNOW TOTALS DURING THE NEXT 3 DAYS WILL
RANGE FROM 2 TO 5 INCHES.
.LONG TERM...MONDAY THROUGH FRIDAY
345 PM CDT FRI FEB 1 2013
ON MONDAY NIGHT AND TUESDAY MORNING...ANOTHER SHORT WAVE WILL BE
MOVING SOUTHEAST THROUGH THE REGION. LIKE THE SYSTEM ON SUNDAY AND
SUNDAY NIGHT...THERE IS NOT MUCH OF THE THE ATMOSPHERIC COLUMN IN
THE DENDRITIC GROWTH ZONE...BUT THERE IS MORE MOISTURE FOR THIS
SYSTEM TO WORK WITH. AS A RESULT...THE SNOW TO LIQUID RATIOS LOOK TO
BE 15-20 TO 1. WITH A TENTH TO 2 TENTHS OF INCH OF QPF...THERE COULD
BE THE POTENTIAL OF ANOTHER 1 TO 3 INCHES OF SNOW.
IT STILL LOOKS LIKE ANOTHER SYSTEM WILL AFFECT THE AREA FROM
WEDNESDAY NIGHT INTO THURSDAY. HOWEVER THE MODELS HAVE BEEN MUCH
LESS CONSISTENT WITH THEIR PRECIPITATION AMOUNTS AND THE LOCATION OF
THIS SYSTEMS WARM FRONT. AS A RESULT...THERE IS MUCH LESS CERTAINTY
THAN THE PREVIOUS 4 SYSTEMS.
&&
.AVIATION...TONIGHT AND SATURDAY
521 PM CST FRI FEB 1 2013
A WEAK AREA OF LOW PRESSURE IS OVER NORTH CENTRAL NEBRASKA LATE
THIS AFTERNOON WITH A WARM FRONT ACROSS NORTHERN IOWA. WATER VAPOR
SATELLITE SHOWS A SHORT WAVE TROUGH ASSOCIATED WITH THE SURFACE
LOW MOVING INTO WESTERN MINNESOTA. THE SHORT WAVE TROUGH IS NOT
VERY STRONG AS EVIDENCE BY THE 4 TO 8 PVU/S OF VORTICITY ADVECTION
IT IS EXPECTED TO GENERATE IN THE 500-300 MB LAYER BUT IT SHOULD
STILL GENERATE A SHORT PERIOD OF WEAK TO MODERATE QG CONVERGENCE
IN THE 850 TO 500 MB LAYER. NORTH OF THE WARM FRONT...WEAK
FRONTOGENESIS IN THE 850-500 MB LAYER ALONG WITH 2 TO 4 UBAR/S OF
UP GLIDE ON THE 275K ISENTROPIC SURFACE WILL COMBINE WITH THE
FORCING FROM THE WAVE TO PRODUCE A PERIOD OF SNOW. CONDITIONS IN
THE SNOW OVER CENTRAL MINNESOTA ARE PRIMARILY MVFR WITH SOME
REDUCTION TO A MILE OR LESS WITH THE VISIBILITY. HAVE BROUGHT
THESE CONDITIONS IN FOR THE EVENING AT BOTH TAF SITES.
OBSERVATIONS BEHIND THE SNOW BAND INDICATE A RETURN TO PRIMARILY
VFR CONDITIONS WITH NO RESTRICTIONS ON THE VISIBILITY AND CEILINGS
OF 3 TO 4K FEET. THE NEXT SYSTEM WILL QUICKLY ADVANCE INTO THE
REGION SATURDAY AFTERNOON ON THE NORTHWEST FLOW ALOFT. CURRENT
INDICATIONS ARE THAT THE MAIN SNOW BAND FROM THIS WAVE MAY GO TO
THE SOUTHWEST OF THE TAF SITES BUT STILL ENOUGH TO DROP KRST BACK
TO MVFR LATE SATURDAY AFTERNOON. KLSE SHOULD SEE THIS NEXT BAND OF
SNOW MOVE IN RIGHT AROUND 00Z AND THIS WILL BE ADDED WITH THE NEXT
FORECAST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
344 PM CST FRI FEB 1 2013
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
AREA FORECAST DISCUSSION
NWS ALBANY NY
416 AM EST SAT FEB 2 2013
.SYNOPSIS...
HIGH PRESSURE WILL BRIEFLY BUILD IN FROM SOUTHERN QUEBEC
THIS MORNING. A CLIPPER LOW WILL APPROACH FROM THE LOWER GREAT
LAKES REGION WITH ISOLATED TO SCATTERED SNOW SHOWERS LATE THIS
AFTERNOON INTO THIS EVENING. ANOTHER CLIPPER WILL IMPACT THE REGION
LATE SUNDAY INTO SUNDAY NIGHT WITH SOME LIGHT SNOW AND CONTINUED
BELOW NORMAL TEMPERATURES TO OPEN NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 345 AM EST...THE LAKE EFFECT SNOWS HAVE ENDED SOUTH AND WEST
OF THE CAPITAL REGION...AS HIGH PRESSURE WILL BRIEFLY BUILD IN
FROM SRN QUEBEC THIS MORNING. A WEAK STATIONARY BOUNDARY OVER
UPSTATE NY AND NEW ENGLAND WILL LIFT BACK NORTHWARD AHEAD OF A
WEAK LOW PRESSURE SYSTEM OVER GEORGIAN BAY.
THE LOW AND MID LEVEL FLOW WILL BACK TO THE W/SW...AND LAKE EFFECT
SNOWFALL WILL BREAK OUT OVER EXTREME NRN NY OFF LAKE ONTARIO. A SW
FLOW TRAJECTORY WILL NOT IMPACT THE ALY FCST AREA MUCH. THE 240
DEGREE TRAJECTORY IS EXPECTED TO IMPACT LOCATIONS JUST NORTH AND
WEST OF THE WRN DACKS. THE LATEST ALY HIRES WRF COMPOSITE
REFLECTIVITY...AND 3-KM HRRR SHOW LITTLE IMPACT IN OUR AREA
TODAY. WE KEPT SOME HIGH CHC AND LIKELY POPS NORTH OF OLD FORGE IN
HERKIMER COUNTY...AND NW HAMILTON COUNTIES. THERE IS SOME WEAK
WARM ADVECTION WITH THE BOUNDARY TOO...SO SOME SLIGHT AND LOW CHC
POPS WERE EXPANDED SOUTH TO THE W-CNTRL MOHAWK VALLEY.
ANOTHER CLIPPER LOW MOVING ACROSS WI/IL THIS MORNING WILL APPROACH
THE REGION FOR LATE THIS AFTERNOON...AND TONIGHT WITH SOME
SCATTERED SNOW SHOWERS OR LIGHT SNOW. THE SHORT-WAVE TO THIS
CLIPPER IS MOVING INTO THE MIDWEST THIS MORNING VIA THE WATER
VAPOR LOOP. CHC POPS WERE EXPANDED OVER MOST OF THE FCST AREA LATE
THIS AFTERNOON INTO EARLY THIS EVENING.
DESPITE WEAK LOW TO MID LEVEL WARM ADVECTION...H850 TEMPS WILL
STILL BE -12C TO -16C FROM SOUTH TO NORTH OVER THE CWA. EXPECT
HIGHS TO BE 5 TO 10 DEGREES BELOW NORMAL WITH HIGHS IN THE MID TO
U20S IN THE CAPITAL DISTRICT...THE MID HUDSON VALLEY...AND CT
VALLEY. EXPECT TEENS TO L20S OVER THE MTNS...LAKE GEORGE
REGION...W-CNTRL MOHAWK VALLEY...SRN VT...AND THE LITCHFIELD HILLS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
TONIGHT...THE FIRST OF TWO CLIPPERS PASSES SOUTH OF THE REGION
WITH SCT SNOW SHOWERS/LIGHT SNOW ENDING FROM NORTH TO SOUTH.
EXPECT MAINLY COATINGS TO A HALF AN INCH AROUND THE REGION.
PORTIONS OF THE ERN CATSKILLS...AND WRN ADIRONDACKS COULD SEE
AROUND AN INCH OR SO. THE FLOW VEERS TO THE W/NW AGAIN WITH THE
UPPER LEVEL TROUGH OVER CNTRL-ERN CANADA CONTINUING TO THE DRIVE
THE WX OVER NY AND NEW ENGLAND. MIN TEMPS WERE BLENDED FROM THE
MET/MAV GUIDANCE WITH SINGLE DIGITS NORTH OF THE CAPITAL
REGION...AND THE MOHAWK VALLEY...AND TEENS FROM THE I-90 CORRIDOR
SOUTH AND EAST.
SUNDAY-SUNDAY NIGHT...ANOTHER LULL IS BRIEFLY EXPECTED IN THE PARADE
OF SHORT-WAVES/CLIPPERS IN THE W/NW FLOW ALOFT SUNDAY MORNING. THE
GUIDANCE HAS TRENDED A BIT SLOWER WITH THE NEXT CLIPPER. SOME
SLIGHT CHC POPS WERE PUT IN DURING THE LATE MORNING WEST OF THE
HUDSON RIVER VALLEY...AND THEN CHC POPS WERE PUT IN EVERYWHERE IN
THE PM INTO THE EVENING. THIS CLIPPER AND ITS ASSOCIATED SHORT-
WAVE MOVE ACROSS THE CNTRL-ERN GREAT LAKES INTO THE REGION. THEIR
IS SOME PRONOUNCED CYCLONIC VORTICITY ADVECTION WITH IT. THE
DISTURBANCE WILL PRODUCE A ROUND OF LIGHT SNOW FOR THE REGION WITH
GENERALLY A DUSTING TO AN INCH OR SO IN MOST LOCATIONS. THE SHORT-
WAVE ENERGY WITH THIS CLIPPER WILL LIKELY PHASE WITH A STORM EAST
OF THE GULF OF MAINE SUNDAY NIGHT. THE STORM WILL INTENSIFY AND
DEEPEN NEAR THE CANADIAN MARITIMES. SOME WESTERLY UPSLOPE OR LAKE
EFFECT SNOWFALL MAY IMPACT THE SRN GREENS AND WRN DACKS. WE HAVE
1-4" OF SNOW SUNDAY TO SUNDAY NIGHT IN THESE AREAS. HIGHS WILL
RANGE FROM THE 20S TO L30S ACROSS THE REGION...TO SINGLE DIGITS TO
TEENS FOR LOWS.
MONDAY-MONDAY NIGHT...THE WORK WEEK WILL OPEN WITH BLUSTERY AND COLD
CONDITIONS...AS A DEEPENING AND INTENSIFYING LOW PRESSURE SYSTEM
MOVES TOWARD LABRADOR...AND ARCTIC HIGH PRESSURE BUILDS IN FROM
THE GREAT LAKES REGION AND ONTARIO. W/NW WINDS OF 15 TO 25 MPH
WILL BE COMMON WITH SOME GUSTS AROUND 30-40 MPH. WESTERLY UPSLOPE
SNOW SHOWERS OVER THE SRN GREENS AND WRN DACKS WILL END DURING THE
AFTERNOON WITH ADDITIONAL LIGHT ACCUMULATIONS. IN THE COLD
ADVECTION REGIME...H850 TEMPS FALL TO -17C TO -22C. MAX TEMPS WILL
CONTINUE TO RUN BELOW NORMAL WITH TEENS TO M20S OVER THE HILLS AND
MTNS...AND L20S TO L30S IN THE VALLEY AREAS. TEMPS MAY FALL DURING
THE AFTERNOON. DIMINISHING WINDS AND FRIGID CONDITIONS ARE
ANTICIPATED MON NIGHT WITH HIGH PRESSURE BUILDING IN WITH LOWS
BELOW ZERO OVER THE ADIRONDACK PARK...AND SRN GREENS...SINGLE
DIGITS EVERYWHERE ELSE...EXCEPT 10-15F IN THE MID HUDSON VALLEY
AND SRN LITCHFIELD COUNTY.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
MODEL GUIDANCE IS IN FAIRLY GOOD AGREEMENT KEEPING THE REGION UNDER
A LONGWAVE TROUGH. A SHORT WAVE IS FORECAST TO MOVE THROUGH THE BASE
OF THE TROUGH TUESDAY NIGHT INTO WEDNESDAY BRINGING THE THREAT FOR
SOME SNOW SHOWERS. THE FLOW ALOFT IS EXPECTED TO BECOME MORE ZONAL
WITH RIDGING BUILDING IN AT THE SURFACE AND IN THE LOW LEVELS OF THE
ATMOSPHERE FOR THURSDAY BETWEEN SHORT WAVES AS THE UPPER LOW OVER
EASTERN CANADA/HUDSONS BAY SHIFTS A BIT NORTHWARD. THE SURFACE HIGH
WILL WEAKEN AND SHIFT EASTWARD AS ANOTHER SHORT WAVE TROUGH
APPROACHES FROM THE GREAT LAKES THURSDAY NIGHT. THE UPPER TROUGH AND
ASSOCIATED SURFACE LOW PRESSURE SHOULD CROSS THE REGION FRIDAY
BRINGING WIDESPREAD CHANCES FOR SNOW SHOWERS. QPF SHOULD BE LIGHT
SINCE MOISTURE ASSOCIATED WITH THE FEATURES WILL BE FAIRLY LIMITED.
AS FOR TEMPERATURES LOOKING AT AROUND SEASONABLE LEVELS FOR EARLY
FEBRUARY. SHOULD WARM TO A BIT ABOVE NORMAL ON FRIDAY AHEAD OF THE
APPROACHING LOW PRESSURE SYSTEM.
NORMALS FEB 5TH-8TH:
ALBANY: HIGHS LOWER 30S. LOWS MID TEENS.
GLENS FALLS: HIGHS LOWER 30S. LOWS UPPER SINGLE DIGITS.
POUGHKEEPSIE: HIGHS UPPER 30S. LOWS UPPER TEENS.
BENNINGTON: HIGHS LOWER 30S. LOWS MID TEENS.
PITTSFIELD: HIGHS AROUND 30. LOWS MID TEENS.
&&
.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
HIGHER PRESSURE BRIEFLY BUILDS INTO THE REGION FROM THE SOUTHWEST
THIS MORNING AND THE LAKE EFFECT SNOW WILL DISSIPATE. A CLIPPER LOW
WILL APPROACH FROM THE GREAT LAKES REGION TODAY AND IS EXPECTED TO
WEAKEN AS IT MOVES OVER THE REGION TONIGHT.
EXPECTING VFR CONDITIONS...THE EXCEPTION WILL BE MVFR CONDITIONS AT
KPSF FOR A COUPLE HOURS AT THE BEGINNING OF THE TAF TIME AND
POSSIBLY AGAIN LATE IN THE EVENING.
GUSTY WEST TO NORTHWEST WINDS AT KALB AND KPSF WILL WEAKEN EARLY
THIS MORNING. THE FLOW WILL SHIFT TO SOUTHWEST TO SOUTH DURING THE
DAY AHEAD OF THE APPROACHING CLIPPER LOW.
OUTLOOK...
SUN...MAINLY VFR. SUB-VFR WITH CHC LIGHT SNOW MID TO LATE AFTN.
SUN NIGHT...MAINLY VFR. SUB-VFR WITH A LIGHT SNOW. AT KPSF SNOW
LIKELY AFTER MIDNIGHT.
MON-TUE...VFR. NO SIG WX.
TUE NIGHT. MAINLY VFR. CHC -SHSN MAINLY AFTER MIDNIGHT.
WED...MAINLY VFR. CHC -SHSN IN THE AM AND SLIGHT CHC IN THE AFTN.
&&
.HYDROLOGY...
THE NEXT 5 DAYS EXTENDING INTO THE MIDDLE OF NEXT WEEK WILL FEATURE
NO HYDRO PROBLEMS. COLD TEMPS AND LIGHT PCPN SYSTEMS /SNOW AS THE
PTYPE/ WILL ALLOW RIVERS AND STREAM TO CONTINUE TO RECEDE FROM
LAST WEEKS STORM SYSTEM.
THE BELOW NORMAL TEMPERATURES WILL ALLOW ICE TO REFORM AND THICKEN
ON BODIES OF WATER IN THE ALBANY HYDRO SERVICE AREA.
FOR SPECIFIC RIVER AND LAKE FORECASTS...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...WASULA
NEAR TERM...WASULA
SHORT TERM...WASULA
LONG TERM...IAA
AVIATION...IAA
HYDROLOGY...WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
111 AM EST SAT FEB 2 2013
.SYNOPSIS...
AS A COLD CANADIAN AIR MASS CONTINUES TO MOVE INTO THE
REGION TODAY...IT WILL BE COLD AND WINDY. SOME LAKE EFFECT SNOW WILL
AFFECT PORTIONS OF THE MOHAWK AND SCHOHARIE VALLEYS AND CAPITAL
REGION THIS MORNING. THE WIND AND SNOW SHOWERS WILL DIMINISH
TONIGHT. IT WILL REMAIN COLD THROUGH THE WEEKEND AND THERE IS A
CHANCE FOR SOME LIGHT SNOW...ESPECIALLY ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1245 AM EST...THE LATEST RUC40 SHOWS A H500 VORT MAX MOVING
ACROSS THE REGION. THE LAKE EFFECT BAND AND SNOW SHOWERS HAVE
DECREASED DRAMATICALLY OVER THE PAST FEW HOURS. A NARROW FILAMENT
CONTINUES OVER THE NRN CATSKILLS IN SCHOHARIE COUNTY...AND THE
HELDERBERGS IN WRN ALBANY COUNTY. A QUICK COATING TO UP TO AN INCH
IS POSSIBLE BEFORE THE BAND FALLS APART WITH THE FLOW CONTINUING
TO VEER TO THE NORTHWEST. THE LATEST HRRR SHOWS THE DISSIPATION OF
THE BAND BTWN 06Z-08Z. THE FLOW WILL BEGIN TO BACK TO THE W/SW TOWARDS
SUNRISE...AS THE NEXT CLIPPER APPROACHES. SOME ISOLD-SCT FLURRIES
AND SNOW SHOWERS MAY IMPACT THE WRN DACKS/WRN MOHAWK VALLEY. THE TEMPS
LOOK ON TRACK...WITH SLIGHT DEVIATIONS UPWARD BASED ON THE
LINGERING CLOUDS.
OVERNIGHT LOWS WILL BE 10-15 DEGREES ALBANY SOUTHWARD..BUT 0-10 TO
THE NORTH AND WEST OF TOWN. SOME OF THE COLDEST SPOTS IN THE
ADIRONDACKS WILL DIP A LITTLE BELOW ZERO. WINDS CHILLS WILL MAKE IT
FEEL A BIT COLDER THAN AT TIMES...BUT NOT LOW ENOUGH TO ISSUE
ADVISORIES.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
A WEAK SHORTWAVE WILL PASS TO THE NORTH OF THE REGION ON SATURDAY
INTO SATURDAY NIGHT. THIS MAY ALLOW FOR SOME LIGHT SNOW SHOWERS
ACROSS THE ADIRONDACKS. BY LATE IN THE DAY A WAVE MOVING FROM THE
THE OHIO VALLEY TO THE MID ATLANTIC STATES MAY BRING A CHANCE FOR
LIGHT SNOW TO THE SOUTHERN PART OF THE FORECAST AREA...GENERALLY
SOUTH OF ALBANY. AS THE WAVE MOVES OFFSHORE SATURDAY NIGHT AND
SUNDAY...IT WILL INDUCE SURFACE LOW DEVELOPMENT...SO THERE WILL BE
A BETTER CHANCE FOR SOME LIGHT SNOW ACROSS THE REGION LATE SATURDAY
NIGHT INTO SUNDAY...ESPECIALLY SOUTH OF ALBANY.
IT WILL REMAIN COLD. HIGHS SATURDAY WILL BE IN THE MID TEENS TO THE
20S. LOWS SATURDAY NIGHT GENERALLY IN THE SINGLE NUMBERS AND
TEENS...AND HIGHS SUNDAY IN THE 20S TO LOWER 30S.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
THE MODELS ARE IN PRETTY GOOD AGREEMENT FOR THE EXTENDED PERIOD. A
LARGE BROAD TROUGH WILL CONTINUE MUCH OF THE PERIOD.
A SERIES OF CLIPPERS WILL CONTINUE TO PARADE THROUGH THE TROUGH
BRINGING THE THREAT OF NUISANCE SNOW SHOWERS...AND PERHAPS MORE
SIGNIFICANT LAKE EFFECT SNOWS. TEMPERATURES WILL CONTINUE TO TREND
BELOW NORMAL.
MONDAY ONE LOW PRESSURE WILL BE DEPARTING WELL TO OUR
EAST...BRINGING ANOTHER SURGE OF MODIFIED ARCTIC AIR ALONG WITH THE
USUAL THREAT OF SNOW SHOWERS OFF LAKE ONTARIO THAT WILL PROBABLY AT
LEAST BRUSHING OUR NORTHWESTERN ZONES AND SOME UPSLOPE SNOW POSSIBLE
ACROSS THE SOUTHERN GREENS. THE REMAINDER OF THE REGION WILL SEE
MAINLY FLURRIES (SLIGHT CHANCE OF SNOW SHOWERS) OR REMAIN DRY WITH
PARTIAL SUNSHINE. HOWEVER IT WILL BE A BRISK DAY ADDING TO THE CHILL.
HIGH PRESSURE LOOKS TO BUILD IN BY TUESDAY...FOLLOWED BY ANOTHER
CLIPPER ON TUESDAY NIGHT INTO WEDNESDAY. THIS STORM LOOKS TO TRACK
SOUTH OF OUR REGION...MAYBE TOO FAR SOUTH TO GET INTO THE BEST SNOW
SHIELD. FOR NOW...WENT WITH 30 POPS TUESDAY NIGHT LOWERING THEM TO
SLIGHT CHANCES ON WEDNESDAY.
ANOTHER HIGH PRESSURE WILL BUILD IN WEDNESDAY NIGHT THROUGH
THURSDAY. THEN ANOTHER CLIPPER TYPE SYSTEM APPROACHES THURSDAY NIGHT
INTO FRIDAY. THE EUROPEAN MODEL SUGGESTED THIS ONE COULD BE A BIT
STRONGER...AND OFFER MORE IN THE WAY OF QPF. IT WOULD BE COLD FOR
ALL SNOW FROM ALBANY NORTH. FURTHER SOUTH...IT MIGHT BE WARM UP
RIGHT NEAR THE SURFACE TO MIX WITH SOME RAIN.
THE 12Z GFS WAS NOT A ROBUST WITH THE STORM...FURTHER NORTH AND
LIGHTER QPF. FOR NOW...WENT WITH A 40 POP BUT DECIDED TO CALL IT
SNOW (AS OPPOSED TO SNOW SHOWERS).
TEMPERATURES GENERALLY LOOK TO STARTED OUT QUITE COLD ON MONDAY AND
TUESDAY...LOWER TO MID 20S FOR HIGHS CAPITAL DISTRICT AND POINTS
SOUTH...TEENS NORTH...WEST AND EVEN EAST OF THE CAPITAL DISTRICT.
HIGHS WILL MODERATE A LITTLE AFTER THAT. BY FRIDAY...HIGHS WILL
REACH THE 30S ALBANY SOUTHWARD...25-30 REMAINDER OF THE REGION.
OVERNIGHT LOWS WILL BE TEENS FROM SOUTH...SINGLE NUMBERS
NORTH...WITH SELECT SPOTS ESPECIALLY IN THE ADIRONDACKS FROM ZERO TO
10 BELOW.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
HIGHER PRESSURE BRIEFLY BUILDS INTO THE REGION FROM THE SOUTHWEST
THIS MORNING AND THE LAKE EFFECT SNOW WILL DISSIPATE. A CLIPPER LOW
WILL APPROACH FROM THE GREAT LAKES REGION TODAY AND IS EXPECTED TO
WEAKEN AS IT MOVES OVER THE REGION TONIGHT.
EXPECTING VFR CONDITIONS...THE EXCEPTION WILL BE MVFR CONDITIONS AT
KPSF FOR A COUPLE HOURS AT THE BEGINNING OF THE TAF TIME AND
POSSIBLY AGAIN LATE IN THE EVENING.
GUSTY WEST TO NORTHWEST WINDS AT KALB AND KPSF WILL WEAKEN EARLY
THIS MORNING. THE FLOW WILL SHIFT TO SOUTHWEST TO SOUTH DURING THE
DAY AHEAD OF THE APPROACHING CLIPPER LOW.
OUTLOOK...
SUN...MAINLY VFR. SUB-VFR WITH CHC SNOW DURING THE AFTN AND EVNG.
MON...MAINLY VFR. SLIGHT CHC -SHSN.
TUE...VFR. NO SIG WX.
TUE NIGHT. MAINLY VFR. CHC -SHSN.
WED...MAINLY VFR. SLIGHT CHC -SHSN.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED DURING THE NEXT FIVE DAYS.
TEMPERATURES WILL BE WELL BELOW FREEZING MOST OF THE TIME DURING THE
NEXT FIVE DAYS AND ONLY SNOWFALL IS EXPECTED IN TERMS OF ANY
PRECIPITATION. WITH THE COLD TEMPERATURES RUNOFF HAS DECREASED
SIGNIFICANTLY AND AREA STREAMS AND RIVERS ARE SLOWLY RECEDING.
FOR SPECIFIC RIVER AND LAKE FORECASTS...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...BGM
NEAR TERM...HWJIV/BGM/WASULA
SHORT TERM...HWJIV/BGM
LONG TERM...HWJIV
AVIATION...IAA
HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
1253 AM EST SAT FEB 2 2013
.SYNOPSIS...
AS A COLD CANADIAN AIR MASS CONTINUES TO MOVE INTO THE
REGION TODAY...IT WILL BE COLD AND WINDY. SOME LAKE EFFECT SNOW WILL
AFFECT PORTIONS OF THE MOHAWK AND SCHOHARIE VALLEYS AND CAPITAL
REGION THIS MORNING. THE WIND AND SNOW SHOWERS WILL DIMINISH
TONIGHT. IT WILL REMAIN COLD THROUGH THE WEEKEND AND THERE IS A
CHANCE FOR SOME LIGHT SNOW...ESPECIALLY ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1245 AM EST...THE LATEST RUC40 SHOWS A H500 VORT MAX MOVING
ACROSS THE REGION. THE LAKE EFFECT BAND AND SNOW SHOWERS HAVE
DECREASED DRAMATICALLY OVER THE PAST FEW HOURS. A NARROW FILAMENT
CONTINUES OVER THE NRN CATSKILLS IN SCHOHARIE COUNTY...AND THE
HELDERBERGS IN WRN ALBANY COUNTY. A QUICK COATING TO UP TO AN INCH
IS POSSIBLE BEFORE THE BAND FALLS APART WITH THE FLOW CONTINUING
TO VEER TO THE NORTHWEST. THE LATEST HRRR SHOWS THE DISSIPATION OF
THE BAND BTWN 06Z-08Z. THE FLOW WILL BEGIN TO BACK TO THE W/SW TOWARDS
SUNRISE...AS THE NEXT CLIPPER APPROACHES. SOME ISOLD-SCT FLURRIES
AND SNOW SHOWERS MAY IMPACT THE WRN DACKS/WRN MOHAWK VALLEY. THE TEMPS
LOOK ON TRACK...WITH SLIGHT DEVIATIONS UPWARD BASED ON THE
LINGERING CLOUDS.
OVERNIGHT LOWS WILL BE 10-15 DEGREES ALBANY SOUTHWARD..BUT 0-10 TO
THE NORTH AND WEST OF TOWN. SOME OF THE COLDEST SPOTS IN THE
ADIRONDACKS WILL DIP A LITTLE BELOW ZERO. WINDS CHILLS WILL MAKE IT
FEEL A BIT COLDER THAN AT TIMES...BUT NOT LOW ENOUGH TO ISSUE
ADVISORIES.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
A WEAK SHORTWAVE WILL PASS TO THE NORTH OF THE REGION ON SATURDAY
INTO SATURDAY NIGHT. THIS MAY ALLOW FOR SOME LIGHT SNOW SHOWERS
ACROSS THE ADIRONDACKS. BY LATE IN THE DAY A WAVE MOVING FROM THE
THE OHIO VALLEY TO THE MID ATLANTIC STATES MAY BRING A CHANCE FOR
LIGHT SNOW TO THE SOUTHERN PART OF THE FORECAST AREA...GENERALLY
SOUTH OF ALBANY. AS THE WAVE MOVES OFFSHORE SATURDAY NIGHT AND
SUNDAY...IT WILL INDUCE SURFACE LOW DEVELOPMENT...SO THERE WILL BE
A BETTER CHANCE FOR SOME LIGHT SNOW ACROSS THE REGION LATE SATURDAY
NIGHT INTO SUNDAY...ESPECIALLY SOUTH OF ALBANY.
IT WILL REMAIN COLD. HIGHS SATURDAY WILL BE IN THE MID TEENS TO THE
20S. LOWS SATURDAY NIGHT GENERALLY IN THE SINGLE NUMBERS AND
TEENS...AND HIGHS SUNDAY IN THE 20S TO LOWER 30S.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
THE MODELS ARE IN PRETTY GOOD AGREEMENT FOR THE EXTENDED PERIOD. A
LARGE BROAD TROUGH WILL CONTINUE MUCH OF THE PERIOD.
A SERIES OF CLIPPERS WILL CONTINUE TO PARADE THROUGH THE TROUGH
BRINGING THE THREAT OF NUISANCE SNOW SHOWERS...AND PERHAPS MORE
SIGNIFICANT LAKE EFFECT SNOWS. TEMPERATURES WILL CONTINUE TO TREND
BELOW NORMAL.
MONDAY ONE LOW PRESSURE WILL BE DEPARTING WELL TO OUR
EAST...BRINGING ANOTHER SURGE OF MODIFIED ARCTIC AIR ALONG WITH THE
USUAL THREAT OF SNOW SHOWERS OFF LAKE ONTARIO THAT WILL PROBABLY AT
LEAST BRUSHING OUR NORTHWESTERN ZONES AND SOME UPSLOPE SNOW POSSIBLE
ACROSS THE SOUTHERN GREENS. THE REMAINDER OF THE REGION WILL SEE
MAINLY FLURRIES (SLIGHT CHANCE OF SNOW SHOWERS) OR REMAIN DRY WITH
PARTIAL SUNSHINE. HOWEVER IT WILL BE A BRISK DAY ADDING TO THE CHILL.
HIGH PRESSURE LOOKS TO BUILD IN BY TUESDAY...FOLLOWED BY ANOTHER
CLIPPER ON TUESDAY NIGHT INTO WEDNESDAY. THIS STORM LOOKS TO TRACK
SOUTH OF OUR REGION...MAYBE TOO FAR SOUTH TO GET INTO THE BEST SNOW
SHIELD. FOR NOW...WENT WITH 30 POPS TUESDAY NIGHT LOWERING THEM TO
SLIGHT CHANCES ON WEDNESDAY.
ANOTHER HIGH PRESSURE WILL BUILD IN WEDNESDAY NIGHT THROUGH
THURSDAY. THEN ANOTHER CLIPPER TYPE SYSTEM APPROACHES THURSDAY NIGHT
INTO FRIDAY. THE EUROPEAN MODEL SUGGESTED THIS ONE COULD BE A BIT
STRONGER...AND OFFER MORE IN THE WAY OF QPF. IT WOULD BE COLD FOR
ALL SNOW FROM ALBANY NORTH. FURTHER SOUTH...IT MIGHT BE WARM UP
RIGHT NEAR THE SURFACE TO MIX WITH SOME RAIN.
THE 12Z GFS WAS NOT A ROBUST WITH THE STORM...FURTHER NORTH AND
LIGHTER QPF. FOR NOW...WENT WITH A 40 POP BUT DECIDED TO CALL IT
SNOW (AS OPPOSED TO SNOW SHOWERS).
TEMPERATURES GENERALLY LOOK TO STARTED OUT QUITE COLD ON MONDAY AND
TUESDAY...LOWER TO MID 20S FOR HIGHS CAPITAL DISTRICT AND POINTS
SOUTH...TEENS NORTH...WEST AND EVEN EAST OF THE CAPITAL DISTRICT.
HIGHS WILL MODERATE A LITTLE AFTER THAT. BY FRIDAY...HIGHS WILL
REACH THE 30S ALBANY SOUTHWARD...25-30 REMAINDER OF THE REGION.
OVERNIGHT LOWS WILL BE TEENS FROM SOUTH...SINGLE NUMBERS
NORTH...WITH SELECT SPOTS ESPECIALLY IN THE ADIRONDACKS FROM ZERO TO
10 BELOW.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
MAINLY VFR CONDITIONS WILL PREVAIL THROUGHOUT SATURDAY.
SNOW SHOWERS HAVE FLARED UP ONCE MORE DOWN THE MOHAWK VALLEY. THREW
IN A FOUR HOUR TEMPO TO INCLUDE AT LEAST A 50 PERCENT CERTAINTY
THAT MVFR SNOW SHOWERS COULD TAKE PLACE UP TO HALF OF THE TIME IN
THAT TIME FRAME. WILL CONTINUE TO MONITOR TRENDS. HAVE CONTINUED THE
TEMPO FOR TEMPO SNOW SHOWERS AT KPSF AS WELL. OTHERWISE VFR
CONDITIONS WILL PREVAIL.
NO SNOW SHOWERS EXPECTED AT THE OTHER SITES. THE SKY WILL REMAIN
PARTLY CLOUDY (PROBABLY FREE OF CIGS). EVEN IF ANY DO BRIEFLY
OCCUR...THEY WOULD BE IN THE MVFR RANGE.
THE GUSTY W TO NW WIND (ESPECIALLY AT KALB) WILL DIMINISH WITH TIME
TO AROUND 5-10KTS. (KEPT TEMPS FOR GUSTY WINDS AROUND 20KTS AT ALL
TAF SITES AWHILE THIS EVENING LONGEST AT KALB AND KPSF).
SATURDAY LOOKS MAINLY DRY TO START...BUT THERE IS A SLIGHT
INCREASING THREAT IN MORE SNOW SHOWER ACTIVITY LATER IN THE DAY AS A
CLIPPER NEARS WITH ITS ASSOCIATED COLD FRONT. THE SOUTH WIND WILL
PICK UP TO NEAR 10KTS MIDDAY (WITH A FEW HIGHER GUSTS POSSIBLE AT
KALB). WE ASSIGNED A VCSH DURING THE AFTERNOON AT ALL TAF SITES TO
INDICATE THE POSSIBILITY OF SNOW SHOWERS AROUND...A FEW WHICH COULD
BRIEFLY DROP CONDITIONS TO MVFR BUT RIGHT CONFIDENCE WAS BELOW 30
PERCENT.
OUTLOOK...
SAT NIGHT..VFR. NO SIG WX.
SUN-SUN NIGHT. MAINLY VFR. CHC SUB-VFR -SHSN.
MON-TUE. VFR. NO SIG WX.
TUE NIGHT-WED. MAINLY VFR. CHC SUB-VFR -SHSN.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED DURING THE NEXT FIVE DAYS.
TEMPERATURES WILL BE WELL BELOW FREEZING MOST OF THE TIME DURING THE
NEXT FIVE DAYS AND ONLY SNOWFALL IS EXPECTED IN TERMS OF ANY
PRECIPITATION. WITH THE COLD TEMPERATURES RUNOFF HAS DECREASED
SIGNIFICANTLY AND AREA STREAMS AND RIVERS ARE SLOWLY RECEDING.
FOR SPECIFIC RIVER AND LAKE FORECASTS...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...BGM
NEAR TERM...HWJIV/BGM/WASULA
SHORT TERM...HWJIV/BGM
LONG TERM...HWJIV
AVIATION...HWJIV
HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1120 PM CST FRI FEB 1 2013
.AVIATION...06Z TAF. SATELLITE AND OBSERVATIONS SHOW SOME LOWER
CLOUDS THAT WILL AFFECT THE KGRI TERMINAL AREA. THESE SHOULD BE
VFR AND SHOULD DIMINISH AFTER DAY BREAK. A SURFACE TROUGH THAT IS
MOVING THROUGH THE AREA AT THIS TIME HAS TURNED WINDS TO THE
NORTHWEST. THEY WILL INCREASE A BIT AROUND SUNRISE...THEN BECOME
GUSTY AND INCREASE THIS AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 656 PM CST FRI FEB 1 2013/
UPDATE...EVENING UPPER AIR ANALYSIS INDICATES LONGWAVE TROUGHING
OVER THE EASTERN TWO-THIRDS OF THE CONUS...WITH RIDGING BUILDING
INTO THE WEST. MID AND UPPER LEVEL FLOW REMAINS FROM THE NORTHWEST
ACROSS THE CENTRAL PLAINS...MAXING OUT AT AROUND 70KTS NEAR 200MB
OVER OUR AREA. WATER VAPOR IMAGERY INDICATES A SUBTLE MID LEVEL
SHORT WAVE EXTENDING FROM THE DAKOTAS...SOUTHWEST INTO WESTERN
NEBRASKA AND SOUTHEASTERN WYOMING. AT THE SURFACE A WEAK AREA OF
BAROMETRIC PRESSURE EXISTS OVER EASTERN SOUTH DAKOTA...WITH A
TROUGH EXTENDING SOUTHWEST FROM THE LOW ACROSS PORTIONS OF
NEBRASKA AND KANSAS. THIS TROUGH PRETTY MUCH BISECTS OUR
CWA...WITH THE LOW LEVEL WIND FIELD ACROSS THE SOUTHEASTERN HALF
OF OUR CWA REMAINING FROM THE SOUTHWEST...AND LOCATIONS FARTHER
NORTHWEST NOW OBSERVING A SURFACE WIND FROM THE NORTHWEST. RADAR
DATA FROM KUEX...KLNX...AND KGLD ALL INDICATE LIGHT ELEVATED
PRECIPITATION EXTENDING FROM PORTIONS OF WESTERN NEBRASKA INTO
NORTHWESTERN KANSAS AND NORTHEASTERN COLORADO. REPORTS OF
PRECIPITATION ACTUALLY BEING REALIZED AT THE SURFACE HAVE BEEN FEW
AND FAR IN BETWEEN HOWEVER...WITH PROXIMITY SOUNDINGS FROM LAPS
AND RAP ANALYSIS INDICATING A VERY DRY LOWER TROPOSPHERE IS LIKELY
PREVENTING MUCH OF ANY PRECIPITATION FROM MAKING IT TO THE
SURFACE.
GUIDANCE FROM THE NAM...OPERATIONAL GFS...EC...SREF-MEAN...AND RAP
ALL SUGGEST THE MID LEVEL SHORT WAVE...CURRENTLY OVER THE NORTHERN
AND CENTRAL PLAINS...WILL CONTINUE MOVING SOUTHEAST TONIGHT...WITH
THE MID LEVEL TROUGH AXIS EXPECTED TO CLEAR OUR CWA SHORTLY AFTER
06Z. VERY WEAK MID LEVEL THERMAL ADVECTION AHEAD OF THE TROUGH
AXIS IS CREATING JUST ENOUGH OMEGA FOR THE ELEVATED PRECIPITATION
CURRENTLY BEING INDICATED BY AREA RADARS...WITH THIS AXIS OF WEAK
OMEGA EXPECTED TO CONTINUE PUSHING ACROSS OUR AREA TONIGHT AS THE
MID LEVEL TROUGH AXIS DOES THE SAME. THE BACK EDGE OF THIS OMEGA
AXIS IS APPARENTLY ALREADY WORKING INTO NORTHERN AND WESTERN
NEBRASKA...WITH KLNX INDICATING THE BACK EDGE ELEVATED
PRECIPITATION EXTENDING FROM NEAR KANW TO NEAR KIBM. GIVEN THE
CURRENT MOVEMENT OF THE MID LEVEL SHORT WAVE ON WATER VAPOR
IMAGERY...AND RADAR TRENDS THROUGH THE PAST 2-3 HOURS...IT APPEARS
THE BEST CHANCE FOR PRECIPITATION OVER OUR AREA WILL OCCUR BETWEEN
NOW AND 06Z...WITH DRY CONDITIONS LIKELY THEREAFTER AS THE MID
LEVEL TROUGH AXIS CLEARS THE AREA AND SUBSIDENCE SETTLES IN.
DESPITE THE RETURNS AS INDICATED BY AREA RADARS...ITS HARD TO
IGNORE THE VERY DRY LOWER TROPOSPHERE CURRENTLY IN PLACE AND THUS
IS SEEMS UNLIKELY MEASURABLE PRECIPITATION WILL BE REALIZED ACROSS
ANY OF OUR CWA TONIGHT. GIVEN THIS...WENT AHEAD AND PULLED POPS
FROM THE FORECAST FOR TONIGHT. THAT BEING SAID...CANNOT COMPLETELY
RULE OUT AN OCCASIONAL SPRINKLE MAKING IT TO THE SURFACE THROUGH
THE NEXT FEW HOURS AS THERE HAVE BEEN A FEW OBSERVATIONS ACROSS
WESTERN NEBRASKA WHICH INDICATED A BRIEF PERIOD OF PRECIPITATION
HERE OR THERE. GIVEN THE AFOREMENTIONED RADAR RETURNS AND
OBSERVATIONS...OPTED TO GO WITH A MENTION OF SPRINKLES ACROSS OR
SOUTHWESTERN CWA THROUGH THIS EVENING AS THE MOST ENHANCED AREA OF
RADAR RETURNS...AROUND 25DBZ...PUSH OVER THOSE AREAS.
PROXIMITY SOUNDINGS FROM ACROSS OUR CWA PER LAPS AND RAP ANALYSIS
INDICATE AN ELEVATED WARM LAYER DOES EXIST NEAR 850MB...WITH
FORECAST PROXIMITY SOUNDINGS PER THE NAM...OPERATIONAL GFS...AND
RAP SUGGESTING THIS ELEVATED WARM LAYER WILL REMAIN INTACT THROUGH
MUCH OF THE NIGHT. IF MORE SIGNIFICANT PRECIPITATION WERE EXPECTED
TO MAKE IT TO THE SURFACE...THIS WOULD CERTAINLY CREATE CONCERNS
WITH RESPECT TO FREEZING RAIN. THAT BEING SAID...BECAUSE THE RADAR
RETURNS THUS FAR THIS EVENING HAVE BEEN SO WEAK...AND BECAUSE THE
MAJORITY GUIDANCE SUGGESTS NO PRECIPITATION WILL BE REALIZED OVER
OUR AREA TONIGHT...AND BECAUSE THERE IS SUCH A DEEP LAYER OF LOWER
TROPOSPHERIC DRY AIR IN PLACE...AM NOT OVERLY CONCERNED WITH AN
ICING THREAT AT THIS TIME. SHOULD SPRINKLES BE REALIZED ACROSS
PORTIONS OF THE CWA AFTER 02Z TONIGHT...THEN TECHNICALLY THESE
WOULD BE FREEZING SPRINKLES AS SURFACE TEMPERATURES WILL HAVE
DROPPED BELOW FREEZING BY THEN. BUT AT THIS TIME THE THREAT OF
ICING FROM SUCH ACTIVITY IS LITTLE TO NONE AND GIVEN THIS...OPTED
TO PULL ANY MENTION OF FREEING RAIN FROM THE HWO.
REMAINDER OF THE FORECAST REMAINS IN GOOD SHAPE...WITH ONLY SOME
MINOR TWEAKS MADE TO HOURLY TEMPERATURE...SKY...WIND...AND
DEWPOINT GRIDS TO ACCOUNT FOR CURRENT OBSERVATIONS.
PREV DISCUSSION... /ISSUED 324 PM CST FRI FEB 1 2013/
A TROF EMBEDDED IN NW FLOW MAY DELIVER A LIGHT WINTRY MIX IN
SPOTS TNGT THEN WE DEAL WITH WINDY CONDITIONS N OF I-80 SAT...
SHORT TERM...TONIGHT AND SATURDAY
UPPER-LEVELS: A +PNA PATTERN WAS IN PLACE...WITH A WRN N AMERICA
RIDGE AND AN ERN TROF. A PAIR OF PV ANOMALIES WERE DIVING DOWN THE
BACK SIDE OF THE LGWV TROF. THE 1ST WAS OVER WY AT MID AFTN WITH THE
2ND OVER ALBERTA HEADING FOR MT. THE FIRST SHRTWV TROF WILL SLIDE
INTO AND THRU KS TNGT. THE SECOND WILL FOLLOW IT INTO NEB AFTER
MIDNGT. A SHRTWV RIDGE FOLLOWS SAT MRNG...WITH A THIRD PV ANOMALY
MISSING AND HEADING INTO IA...AS THE LGWV PATTERN PROGRESSES A BIT
AND HGTS RISE.
STRONG MO HIGH PRES WILL DEPART TO THE MID-ATLC STATES TNGT. THE
ARCTIC FRONT BISECTED NEB-KS. THIS FRONT AND ITS THERMAL RIBBON WERE
BEING SHOVED E BY SW FLOW AHEAD OF A VERY WEAK SFC LOW. THIS LOW
TRACKS JUST N OF THE FCST AREA...TO THE MS RIVER BY DAYBREAK SAT.
HIGH PRES FOLLOWS HERE TOMORROW.
TNGT: VARIABLE CLOUDS BUT OVERALL EXPECT SKIES TO AVERAGE M/CLOUDY.
EXPANDED THREAT OF VERY LIGHT PCPN TO THE ENTIRE FCST AREA AND WE
NOW HAVE CHANCE POPS FOR AREAS NE OF THE TRI-CITIES AND FROM HWY
136 DOWN INTO N-CNTRL KS. ODDS ARE MOST PLACES REMAIN DRY WITH
LACK OF MSTR IN THE SUB-CLOUD LAYER...BUT WAS NOT COMFORTABLE WITH
AN ENTIRELY DRY FCST.
NEXT ISSUE IS PCPN TYPE. BOTH DDC/LBF HAD A WARM NOSE IN 12Z
SOUNDINGS. NAM/GFS BUFKIT SOUNDINGS SUGGEST 850 MB HAS WARMED TO
+3C OVERHEAD THIS AFTN. SO "IF" PCPN FALLS TNGT...PLAYED IT AS
FLURRIES OR A BRIEF SNOW SHWR NE OF THE TRI-CITIES...FLURRIES OR
SPRINKLES IN THE TRI-CITIES...AND SPRINKLES AND POSSIBLY A RAIN
SHWR S OF HWY 6 INTO N-CNTRL KS. THAT SAID...BELOIT IS STILL SUB-
FRZG AND THE REST OF N-CNTRL KS NOT MUCH ABOVE FRZG. IF TEMPS
COOL BACK DOWN BELOW FRZG AND A FEW -SHRA OCCUR...THERE COULD BE A
TOUCH OF GLAZE. THE LOW PROBABILITY THREAT IS NOW OUTLOOKED IN THE
HWO.
BEST CHANCE OF PCPN WILL OCCUR 9PM-3AM.
USED BURST OF PW AND K-INDEX TO ASSIST IN TIMING/LOCATION OF POPS
THRU THE FCST AREA. CHANCE POPS S OF HWY 136 WERE BASED ON HI-RES
MODEL REFLECTIVITY WHICH IS SUPPORTED BY THE TRACK OF THE PV
ANOMALY.
TEMPS: VARIABLE CLOUD COVER LOWERS CONFIDENCE SOMEWHAT...BUT
OVERALL THINK IT WILL BE A MILD NGT. TEMPS ARE BIAS CORRECTED
BLEND OF 2M TEMPS AND THE PREVIOUS GID FCST /21-27F/.
SAT: SKIES SHOULD BE P/CLOUDY S AND W OF THE TRI-CITIES AT DAWN...
AND M/CLOUDY N AND E. CLEARING AS THE DAY PROGRESSES AND WINDY N OF
I-80 IN THE "WARM" SECTOR OF THE NEXT PV ANOMALY AND CLIPPER FCST
OVER IA.
WIND: THERE IS A LOW PROBABILITY WE MAY NEED A WIND ADVISORY FOR
SOME OF OUR COUNTIES N OF I-80. SUBJECTIVE PROBABILITY PUTS IT
AROUND 40 PERCENT. WITH THE STRENGTH OF THE LOW-LEVEL WIND
FIELDS...BUFKIT MIXING HGTS ARE UNNERVING FROM BOTH THE NAM/GFS.
FOR NOW WE/VE INCLUDED G40 MPH IN THE FCST. THE MAIN CORE OF THE
STRONGEST WIND MOVES IN AFTER 21Z. THE 15Z SREF MEAN INCREASES
SPEEDS 40-45 KTS 21Z-00Z. THIS COINCIDES WITH PEAK HEATING AND
WILL NEED TO BE CONSIDERED BY THE MID SHIFT.
TEMPS ARE BIAS CORRECTED MOS GUIDE WITH SOME ADDITIONAL LOWERING
OF TEMPS OVER THE SNOW COVER S AND E OF HASTINGS AND SOME RAISING
FROM LXN DOWN TO THE KS BORDER...WHERE BIAS CORRECTION PROBABLY
CUT TEMPS TOO MUCH.
LONG TERM...SATURDAY NIGHT THROUGH FRIDAY. BEGINNING SATURDAY
NIGHT...A NORTHWEST FLOW PATTERN WILL BE IN PLACE ACROSS THE CENTRAL
PLAINS AND SHORTWAVE ENERGY IS PROGGED TO TRANSLATE SOUTHEAST ALONG
THE MISSOURI RIVER. COLD AIR BACKS IN BRIEFLY FOR THE OVERNIGHT
TIME FRAME...THEN IN RETURN FLOW ON SUNDAY THE AIRMASS MODERATES
BEHIND THE DEPARTING WAVE. THE NORTHWEST FLOW PATTERN REMAINS
PROGRESSIVE THROUGH MID WEEK WEEK WITH A SERIES OF WAVES TRANSLATING
THRU FLOW...MAINLY ALONG AND EAST OF THE MISSOURI RIVER...WHICH WILL
BRING A FEW COLD FRONTS ACROSS THE PLAINS WITH THE BRUNT OF THE
COOLER AIR REMAINING TO OUR EAST. IN THIS REGIME WE WILL SEE
ALTERNATING PERIODS OF WAA/CAA BUT WITH CONDITIONS REMAINING DRY.
AROUND MID WEEK...THE RIDGING OVER THE ROCKIES BREAKS DOWN AND
SETTLES ONTO THE PLAINS ALLOWING FOR A PROGRESSIVE BUT MORE ZONAL
FLOW PATTERN. EXTENDED MODELS ARE FAIRLY CONSISTENT WITH YET
ANOTHER SHORTWAVE TROUGH TO CROSS THE NORTHERN AND CENTRAL PLAINS
WEDNESDAY NIGHT...AND MODELS ARE HINTING THAT FRONT MAY BECOME
ACTIVE WEDNESDAY NIGHT NEAR OUR SOUTHEAST ZONES. CONFIDENCE IN PCPN
THIS FAR OUT IS NOT HIGH AND WILL CONTINUE TO MONITOR. ONCE THIS
WAVE DEPARTS...AN UPPER RIDGE SETTLES ACROSS THE INTERIOR CONUS
WHILE AN UPSTREAM TROUGH MOVES INTO THE ROCKIES. THE WEATHER
PATTERN LOOKS TO BECOME MORE ACTIVE NEXT WEEKEND WITH THE
PROGRESSION OF THE WESTERN TROUGH AND THIS WILL BE SOMETHING TO KEEP
AN EYE ON. UNTIL THAT TIME FRAME HOWEVER...LOOK FOR MAINLY DRY
CONDITIONS WITH TEMPS ABOVE NORMAL FOR THE MOST PART...ESPECIALLY
AFTER THE SNOW MELTS IN OUR EASTERN ZONES.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
400 AM CST SAT FEB 2 2013
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
MAIN FORECAST CHALLENGES INCLUDE LIGHT SNOW CHANCES AND TEMPERATURES.
GFS/NAM/ECMWF/GEM IN GOOD AGREEMENT AND WILL USE A BLENDED SOLUTION
FOR THIS FORECAST PACKAGE.
FOR TODAY...A CLIPPER SYSTEM IN NORTHWEST FLOW ALOFT WILL MOVE ACROSS
THE NORTHERN PLAINS. MOST OF THE FORECAST AREA WILL REMAIN ON THE COOL
SIDE OF THE SYSTEM AS THE SURFACE LOW TRACKS FROM CENTRAL SASKATCHEWAN
TO NORTHEAST SD. AFTERNOON HIGHS WILL MAINLY BE IN THE SINGLE DIGITS
TO LOW TEENS ABOVE ZERO...BUT AREAS WEST OF A LINE FROM DEVILS LAKE
TO VALLEY CITY TO LISBON MAY CLIMB INTO THE LOW 20S. CANADIAN RADARS
SHOW LIGHT SNOW SOUTH AND EAST OF THE SURFACE LOW AND THIS BAND IS
EXPECTED TO MOVE SOUTHEASTWARD THROUGH THE DAY...MAINLY IMPACTING
EASTERN ND INTO WEST CENTRAL MN. SLOWED THE TIMING OF THE HIGHEST
POPS AS LATEST RAP OUTPUT KEEPS MAJORITY OF PRECIPITATION OUT OF
THE FORECAST AREA UNTIL AFTER 15 UTC. TOTAL ACCUMULATIONS THROUGH
TONIGHT WILL GENERALLY BE AN INCH OR LESS.
REMAINING SNOW SHOWERS EXPECTED TO MOVE EAST OF THE FORECAST AREA
BY MIDNIGHT WITH DECREASING CLOUD COVER FROM WEST TO EAST. SUNDAY
MORNING LOWS EXPECTED IN THE 0 TO 10 BELOW RANGE...BUT WILL BE
HIGHLY DEPENDENT ON CLOUD COVER.
ANOTHER WEAK CLIPPER DROPS SOUTH ON SUNDAY...BRINGING A NARROW
BAND OF LIGHT SNOW FROM CENTRAL ND INTO SOUTHWEST MN. STRONG
SURFACE HIGH WILL MOVE INTO THE NORTHERN VALLEY BY 06 UTC MONDAY
AND THIS WILL LIMIT NORTHWARD EXTENT OF PRECIPITATION. MODEL
TRENDS PLACE SNOW FARTHER SOUTH...SO ADJUSTED HIGHEST POPS SOUTH
OF A LINE FROM DEVILS LAKE TO HILLSBORO TO PARK RAPIDS.
ACCUMULATIONS EXPECTED TO BE EVEN LESS THAN TODAY...GENERALLY A
HALF INCH OF LESS. SKIES WILL BE MOSTLY CLOUDY AND TEMPERATURES
WILL BE NEAR OR SLIGHTLY COOLER THAN TODAY IN THE WAKE OF TODAY/S
SYSTEM.
THE PARADE OF CLIPPERS CONTINUE INTO EARLY NEXT WEEK WITH A THIRD
WAVE ON MONDAY. THE TRACK OF THE SURFACE LOW IS A BIT FARTHER
NORTH...SO EXPECT GREATER SPATIAL COVERAGE OF ACCUMULATING
SNOWFALL. STRONG MID-LEVEL WARM AIR ADVECTION WILL COMBINE UPPER
JET DYNAMICS TO PRODUCE A COUPLE INCHES OF SNOW ACROSS THE
NORTHERN VALLEY INTO NORTHWEST MN. WITH TRACK OF THE LOW AND
ALIGNMENT OF THE BAROCLINIC AXIS...TEMPERATURES WILL BE A BIT
WARMER WITH AFTERNOON HIGHS MAINLY IN THE TEENS ABOVE ZERO.
MORNING LOWS WILL CONTINUE TO BE DEPENDENT ON CLOUD COVER...BUT
NOT EXPECTING MUCH DAY TO DAY CHANGE WITH THE COOLEST READINGS
ACROSS THE LAKE OF THE WOODS REGION.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
NW FLOW ALOFT WILL SLOWLY TRANSITION TO A MORE ZONAL/SW FLOW ALOFT
BY NEXT WEEKEND. THIS WILL MEAN GRADUALLY WARMING TEMPS ABOVE NORMAL
WITH MINIMAL CHANCES FOR PRECIP THROUGH SAT. THERE IS THE POTENTIAL
FOR SOME LINGERING LIGHT SNOW EARLY TUE IN THE EAST...AND IN THE
NORTH ON WED WITH SOME WAA. OTHERWISE...EXPECT A DRY EXTENDED WITH
A WARMING TREND. THERE ARE SOME HINTS AT A POTENTIAL STORM BY LATE
SAT INTO SUNDAY...WITH THE MAIN POTENTIAL IMPACTS AT THIS TIME
POSSIBLE IN THE SOUTHERN FORECAST AREA.
&&
.AVIATION...
VFR/MVFR CEILINGS WILL INCREASE FROM WEST TO EAST THROUGH THE DAY AS
A LOW PRESSURE SYSTEM MOVES ACROSS THE REGION. SOME LIGHT SNOW IS
POSSIBLE FOR AIRFIELDS ALONG AND WEST OF THE VALLEY AFTER 15 UTC.
SNOW SHOULD BE LIGHT...BUT SOME REDUCTIONS IN VISIBILITY LESS THAN
ONE MILE ARE POSSIBLE. LIGHT SOUTH-SOUTHWEST WIND THROUGH THE DAY
WILL INCREASE AND SHIFT TO THE NORTHWEST THIS EVENING AND
OVERNIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
ROGERS/DK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1249 AM CST SAT FEB 2 2013
.DISCUSSION...
LIGHT SNOW CONTINUES TO SLOWLY SPREAD EAST ACROSS WESTERN AND
CENTRAL NORTH DAKOTA EARLY THIS MORNING...WITH A SHARP GRADIENT
ALONG THE EASTERN PERIPHERY OF THE SURFACE HIGH PRESSURE OVER THE
EAST. THE DRY AIR ASSOCIATED WITH THIS SURFACE HIGH WILL CONTINUE
TO LIMIT THE EASTERN EXTENT OF THE AREA OF LIGHT SNOW. HAVE OPTED TO
TRIM BACK POPS/QPF ACROSS THE CENTRAL...USING THE LATEST RADAR DATA
AND RAP SOLUTION AS A GUIDE. OTHERWISE...MINOR ADJUSTMENTS TO ALL
OTHER GRIDS TO REFLECT CURRENT OBS AND TRENDS.
&&
.AVIATION...
LOW PRESSURE WILL DROP SOUTHEAST ACROSS ALBERTA AND
SASKATCHEWAN LATE TONIGHT THEN ACROSS CENTRAL AND INTO SOUTHEAST
NORTH DAKOTA ON SATURDAY. LIGHT NORTH TO NORTHWEST WINDS WILL SHIFT
SOUTH TO SOUTHWEST LATE TONIGHT THEN BACK NORTHWEST ON SATURDAY
BEHIND THE SURFACE LOW. WINDS WILL BECOME GUSTY BY SATURDAY
AFTERNOON THEN DIMINISH BY SATURDAY EVENING. WIDESPREAD MVFR-IFR
CEILINGS AND VISIBILITIES WILL REMAIN OVER WESTERN AND CENTRAL NORTH
DAKOTA AHEAD OF THE APPROACHING SURFACE LOW. LOWEST VISIBILITIES IN
SNOW WILL REMAIN FROM MINOT TO JAMESTOWN ON SATURDAY...CLOSE TO THE
TRACK OF THE LOW. EXPECT IMPROVING CEILINGS SATURDAY EVENING FROM
WEST TO EAST.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 9 AM CST /8 AM MST/ THIS MORNING TO 6 PM CST
/5 PM MST/ THIS EVENING FOR NDZ001>003-009>011-017>021-031>035-
040>046.
WIND ADVISORY FROM NOON TODAY TO 6 PM CST THIS EVENING FOR
NDZ004-005-012-013-022-023-025-036-037-047-048-050-051.
&&
$$
SHORT TERM...HUBER
AVIATION...
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1126 PM CST FRI FEB 1 2013
.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT
345 PM CDT FRI FEB 1 2013
AT 3 PM...THE WATER VAPOR IMAGERY SHOWED A SHORT WAVE TROUGH MOVING
SOUTHEAST THROUGH LAKE WINNIPEG. AT THE THE SURFACE...A COLD
FRONT...LOCATED JUST SOUTH OF LAKE WINNE PEG...WAS PRODUCING SNOW
ACROSS THE EASTERN DAKOTAS...AND NORTHWEST AND WEST CENTRAL
MINNESOTA. THIS SNOW WAS REDUCING VISIBILITIES TO 3/4 MILES AT FARGO
NORTH DAKOTA.
FOR TONIGHT...THE 01.12Z MESO AND DETERMINISTIC MODELS ARE IN GOOD
AGREEMENT THAT SHORT WAVE TROUGH AND COLD FRONT TO OUR NORTHWEST
WILL MOVE SOUTHEAST THROUGH THE FORECAST AREA THIS EVENING AND EARLY
OVERNIGHT. MODERATE 270 TO 280K ISENTROPIC LIFT /2 TO 4
MICROBARS/SEC/ DEVELOPS AHEAD OF THIS SYSTEM. THIS IS BRINGING THE
WARMER AND MORE MOIST /DEW POINTS IN THE LOWER AND MID 20S/ AIR
ALOFT. THIS WARMS THE ATMOSPHERIC COLUMN INTO THE DENDRITIC GROWTH
ZONE AND THE MOISTURE SATURATES IT. 01.09Z SREF SHOWS THAT 50 TO
70 PERCENT OF THE ENSEMBLE FAMILY HAS OVER 200 MB OF DENDRITIC
GROWTH THIS EVENING. THE ROCHESTER RAP BUFKIT SOUNDING SHOWS AT
LEAST 10K FEET IN THE DENDRITIC GROWTH ZONE BETWEEN 02.00Z AND
02.06Z. MEANWHILE THE GFS AND NAM BUFKIT SOUNDINGS HAVE A MUCH
SHORTER TIME. THIS WILL AFFECT THE SNOW RATIOS. THE RAP WOULD
SUGGEST 25-30 TO 1 SNOW TO LIQUID RATIOS. MEANWHILE THE GFS AND NAM
WOULD SUGGEST 17-23 TO 1 SNOW TO LIQUID RATIOS. SINCE THE SYSTEM IS
MOVING SO FAST...TRENDED MORE TOWARD THE GFS AND NAM SOLUTIONS.
THIS WOULD PRODUCE A 1 TO 2 INCH SNOW BAND ACROSS NORTHEAST IOWA AND
AND SOUTHWEST WISCONSIN...AND AROUND AN INCH NORTHWARD TO WISCONSIN
10.
ON SATURDAY AFTERNOON AND NIGHT...ANOTHER SHORT WAVE TROUGH WILL
MOVE SOUTHEAST THROUGH THE REGION. UNLIKE YESTERDAY...HAS THE LEFT
ENTRANCE REGION OF THE 250 MB JET A BIT FURTHER SOUTHEAST. AS A
RESULT...THE OMEGA IS NOT AS STRONG OR DEEP AS IT WAS YESTERDAY.
DESPITE THIS THERE IS MODERATE 270 TO 280K LIFT AHEAD OF THIS WAVE
AND THIS WILL ONCE AGAIN BRING SOME MOISTURE AND WARMER AIR ALOFT
FROM THE NORTHERN AND CENTRAL PLAINS. HOWEVER 01.09Z SREF SHOWS
FEWER MEMBERS HAVING 200 MB OR GREATER OF DENDRITIC GROWTH. THE COBB
DATA SUGGESTS 17-22 TO 1 SNOW TO LIQUID RATIOS. THIS WOULD RESULT IN
AROUND AN INCH OF SNOW FOR MUCH OF THE AREA.
FROM LATE SUNDAY AFTERNOON INTO SUNDAY NIGHT...THE MODELS SHOW YET
ANOTHER SHORT WAVE TROUGH WILL BE MOVING SOUTHEAST THROUGH THE
REGION. BY THIS TIME...THE AIR MASS WILL BE A BIT WARMER. AS A
RESULT...THE BEST ISENTROPIC LIFT IS TAKING PLACE BETWEEN 280 AND
300K. WITH THE AIR MASS WARMER...THERE IS LESS OF A LAYER IN
DENDRITIC GROWTH ZONE. HOWEVER THERE IS A BIT MORE MOISTURE FOR THIS
SYSTEM TO WORK WITH...SO IT LOOKS LIKE SNOW TOTALS WILL RANGE FROM 1
TO 2 INCHES.
OVERALL...IT LOOKS LIKE SNOW TOTALS DURING THE NEXT 3 DAYS WILL
RANGE FROM 2 TO 5 INCHES.
.LONG TERM...MONDAY THROUGH FRIDAY
345 PM CDT FRI FEB 1 2013
ON MONDAY NIGHT AND TUESDAY MORNING...ANOTHER SHORT WAVE WILL BE
MOVING SOUTHEAST THROUGH THE REGION. LIKE THE SYSTEM ON SUNDAY AND
SUNDAY NIGHT...THERE IS NOT MUCH OF THE THE ATMOSPHERIC COLUMN IN
THE DENDRITIC GROWTH ZONE...BUT THERE IS MORE MOISTURE FOR THIS
SYSTEM TO WORK WITH. AS A RESULT...THE SNOW TO LIQUID RATIOS LOOK TO
BE 15-20 TO 1. WITH A TENTH TO 2 TENTHS OF INCH OF QPF...THERE COULD
BE THE POTENTIAL OF ANOTHER 1 TO 3 INCHES OF SNOW.
IT STILL LOOKS LIKE ANOTHER SYSTEM WILL AFFECT THE AREA FROM
WEDNESDAY NIGHT INTO THURSDAY. HOWEVER THE MODELS HAVE BEEN MUCH
LESS CONSISTENT WITH THEIR PRECIPITATION AMOUNTS AND THE LOCATION OF
THIS SYSTEMS WARM FRONT. AS A RESULT...THERE IS MUCH LESS CERTAINTY
THAN THE PREVIOUS 4 SYSTEMS.
&&
.AVIATION...THROUGH 06Z SUNDAY
1126 PM CST FRI FEB 1 2013
THE SNOW CONTINUES TO MOVE SOUTHEAST ACROSS THE REGION WITH THE
LOCAL RADAR SHOWING THAT THE BULK OF IT SHOULD BE PAST BOTH TAF
SITES BY 06Z. STILL SOME RETURNS SHOWING UP ON THE KMPX RADAR WITH
SURFACE OBSERVATIONS SHOWING VISIBILITIES DOWN TO 3 OR 4 MILES AT
TIMES. WILL SHOW THIS IN THE TAFS UNTIL THE WINDS SWING AROUND TO
THE NORTH/NORTHWEST ONCE THE SURFACE LOW MOVES ACROSS NORTHERN
IOWA INTO ILLINOIS. HIGH PRESSURE OVER MANITOBA WILL QUICKLY MOVE
OVER THE REGION SATURDAY ALLOWING THE CLOUDS TO SCATTER OUT FOR A
SHORT PERIOD BEFORE THE NEXT SYSTEM STARTS TO COME IN. THE 02.00Z
NAM SUGGEST THE PV ADVECTION IN THE 500-300 MB LAYER WILL BE
STRONGER WITH THIS NEXT SHORT WAVE TROUGH THAN WITH THE ONE THIS
EVENING WITH UP TO 12 PVU/S POSSIBLE. THE WAVE SHOULD ALSO PRODUCE
WEAK TO MODERATE QG CONVERGENCE ON THE 850-500 MB LAYER.
HOWEVER...THERE SHOULD BE VERY LITTLE FRONTOGENESIS WITH JUST A
WEAK SIGNAL IN THE 1000-850 MB LAYER. THE BEST ISENTROPIC UP GLIDE
WILL SLIDE WEST OF THE REGION WITH ONLY 1 UBAR/S POSSIBLE ON THE
275K SURFACE. EXPECT THAT THE FORCING WITH THIS WAVE WILL BE
ENOUGH TO GENERATE ANOTHER ROUND OF SNOW WITH MVFR CONDITIONS AND
WILL BRING THE SNOW INTO BOTH TAF SITES AROUND 03.03Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
344 PM CST FRI FEB 1 2013
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
AREA FORECAST DISCUSSION
NWS ALBANY NY
929 AM EST SAT FEB 2 2013
.SYNOPSIS...
A CLIPPER LOW WILL APPROACH FROM THE LOWER GREAT LAKES
REGION WITH ISOLATED TO SCATTERED SNOW SHOWERS LATE THIS AFTERNOON
INTO THIS EVENING. ANOTHER CLIPPER WILL IMPACT THE REGION LATE
SUNDAY INTO SUNDAY NIGHT WITH SOME LIGHT SNOW AND CONTINUED BELOW
NORMAL TEMPERATURES TO OPEN NEXT WEEK. MUCH OF THE UPCOMING WEEK
WILL BE DRY WITH SEASONABLY CHILLY TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 929 AM EST...A BAND OF LAKE EFFECT SNOW HAS DEVELOPED OFF
LAKE ONTARIO...BUT IS REMAINING NORTHWEST OF OUR FORECAST AREA
ACROSS THE TUG HILL PLATEAU AND INTO THE ST. LAWRENCE VALLEY.
WITH A SW FLOW TRAJECTORY IN PLACE...THIS BAND SHOULD REMAIN JUST
NORTHWEST OF OUR FORECAST AREA TODAY. THE 240 DEGREE TRAJECTORY
IS EXPECTED TO IMPACT LOCATIONS JUST NORTH AND WEST OF THE WRN
DACKS. THE LATEST 12Z ALY HIRES WRF COMPOSITE REFLECTIVITY...AND
3-KM HRRR SHOW LITTLE IMPACT IN OUR AREA TODAY. WE KEPT SOME HIGH
CHC AND LIKELY POPS NORTH OF OLD FORGE IN HERKIMER COUNTY...AND
FAR NW HAMILTON COUNTY...BUT THE CORE OF THE BAND SHOULD REMAIN TO
THE NW.
A WEAK CLIPPER LOW IS MOVING ACROSS THE OHIO VALLEY THIS MORNING
AS SEEN VIA THE WATER VAPOR LOOP. THIS SYSTEM WILL APPROACH FOR
THE LATE AFTN AND EARLY EVENING HOURS. THERE IS LITTLE MOISTURE
FOR THIS SYSTEM TO WORK WITH...AND WITH THE SYSTEM BEING RATHER
WEAK...FORCING WILL BE LIMITED. VERY DRY LOW LEVELS WILL ALLOW FOR
SOME OF THE LITTLE MOISTURE THIS SYSTEM HAS TO BE LOST AS VIRGA.
WE WILL GO WITH SLIGHT CHC TO CHC POPS FOR MOST OF THE AREA DURING
THE AFTN/EARLY EVENING TO ACCOUNT FOR SOME LIGHT SNOW SHOWERS
ACTIVITY...WITH THE BEST CHC OF SEEING ACTIVITY ACROSS WESTERN
AREAS AND THE HIGH TERRAIN.
DESPITE WEAK LOW TO MID LEVEL WARM ADVECTION...H850 TEMPS WILL
STILL BE -12C TO -16C FROM SOUTH TO NORTH OVER THE CWA. EXPECT
HIGHS TO BE 5 TO 10 DEGREES BELOW NORMAL WITH HIGHS IN THE MID TO
U20S IN THE CAPITAL DISTRICT...THE MID HUDSON VALLEY...AND CT
VALLEY. EXPECT TEENS TO L20S OVER THE MTNS...LAKE GEORGE
REGION...W-CNTRL MOHAWK VALLEY...SRN VT...AND THE LITCHFIELD HILLS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
TONIGHT...THE FIRST OF TWO CLIPPERS PASSES SOUTH OF THE REGION
WITH SCT SNOW SHOWERS/LIGHT SNOW ENDING FROM NORTH TO SOUTH.
EXPECT MAINLY COATINGS TO A HALF AN INCH AROUND THE REGION.
PORTIONS OF THE ERN CATSKILLS...AND WRN ADIRONDACKS COULD SEE
AROUND AN INCH OR SO. THE FLOW VEERS TO THE W/NW AGAIN WITH THE
UPPER LEVEL TROUGH OVER CNTRL-ERN CANADA CONTINUING TO THE DRIVE
THE WX OVER NY AND NEW ENGLAND. MIN TEMPS WERE BLENDED FROM THE
MET/MAV GUIDANCE WITH SINGLE DIGITS NORTH OF THE CAPITAL
REGION...AND THE MOHAWK VALLEY...AND TEENS FROM THE I-90 CORRIDOR
SOUTH AND EAST.
SUNDAY-SUNDAY NIGHT...ANOTHER LULL IS BRIEFLY EXPECTED IN THE PARADE
OF SHORT-WAVES/CLIPPERS IN THE W/NW FLOW ALOFT SUNDAY MORNING. THE
GUIDANCE HAS TRENDED A BIT SLOWER WITH THE NEXT CLIPPER. SOME
SLIGHT CHC POPS WERE PUT IN DURING THE LATE MORNING WEST OF THE
HUDSON RIVER VALLEY...AND THEN CHC POPS WERE PUT IN EVERYWHERE IN
THE PM INTO THE EVENING. THIS CLIPPER AND ITS ASSOCIATED SHORT-
WAVE MOVE ACROSS THE CNTRL-ERN GREAT LAKES INTO THE REGION. THEIR
IS SOME PRONOUNCED CYCLONIC VORTICITY ADVECTION WITH IT. THE
DISTURBANCE WILL PRODUCE A ROUND OF LIGHT SNOW FOR THE REGION WITH
GENERALLY A DUSTING TO AN INCH OR SO IN MOST LOCATIONS. THE SHORT-
WAVE ENERGY WITH THIS CLIPPER WILL LIKELY PHASE WITH A STORM EAST
OF THE GULF OF MAINE SUNDAY NIGHT. THE STORM WILL INTENSIFY AND
DEEPEN NEAR THE CANADIAN MARITIMES. SOME WESTERLY UPSLOPE OR LAKE
EFFECT SNOWFALL MAY IMPACT THE SRN GREENS AND WRN DACKS. WE HAVE
1-4" OF SNOW SUNDAY TO SUNDAY NIGHT IN THESE AREAS. HIGHS WILL
RANGE FROM THE 20S TO L30S ACROSS THE REGION...TO SINGLE DIGITS TO
TEENS FOR LOWS.
MONDAY-MONDAY NIGHT...THE WORK WEEK WILL OPEN WITH BLUSTERY AND COLD
CONDITIONS...AS A DEEPENING AND INTENSIFYING LOW PRESSURE SYSTEM
MOVES TOWARD LABRADOR...AND ARCTIC HIGH PRESSURE BUILDS IN FROM
THE GREAT LAKES REGION AND ONTARIO. W/NW WINDS OF 15 TO 25 MPH
WILL BE COMMON WITH SOME GUSTS AROUND 30-40 MPH. WESTERLY UPSLOPE
SNOW SHOWERS OVER THE SRN GREENS AND WRN DACKS WILL END DURING THE
AFTERNOON WITH ADDITIONAL LIGHT ACCUMULATIONS. IN THE COLD
ADVECTION REGIME...H850 TEMPS FALL TO -17C TO -22C. MAX TEMPS WILL
CONTINUE TO RUN BELOW NORMAL WITH TEENS TO M20S OVER THE HILLS AND
MTNS...AND L20S TO L30S IN THE VALLEY AREAS. TEMPS MAY FALL DURING
THE AFTERNOON. DIMINISHING WINDS AND FRIGID CONDITIONS ARE
ANTICIPATED MON NIGHT WITH HIGH PRESSURE BUILDING IN WITH LOWS
BELOW ZERO OVER THE ADIRONDACK PARK...AND SRN GREENS...SINGLE
DIGITS EVERYWHERE ELSE...EXCEPT 10-15F IN THE MID HUDSON VALLEY
AND SRN LITCHFIELD COUNTY.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
MODEL GUIDANCE IS IN FAIRLY GOOD AGREEMENT KEEPING THE REGION UNDER
A LONGWAVE TROUGH. A SHORT WAVE IS FORECAST TO MOVE THROUGH THE BASE
OF THE TROUGH TUESDAY NIGHT INTO WEDNESDAY BRINGING THE THREAT FOR
SOME SNOW SHOWERS. THE FLOW ALOFT IS EXPECTED TO BECOME MORE ZONAL
WITH RIDGING BUILDING IN AT THE SURFACE AND IN THE LOW LEVELS OF THE
ATMOSPHERE FOR THURSDAY BETWEEN SHORT WAVES AS THE UPPER LOW OVER
EASTERN CANADA/HUDSONS BAY SHIFTS A BIT NORTHWARD. THE SURFACE HIGH
WILL WEAKEN AND SHIFT EASTWARD AS ANOTHER SHORT WAVE TROUGH
APPROACHES FROM THE GREAT LAKES THURSDAY NIGHT. THE UPPER TROUGH AND
ASSOCIATED SURFACE LOW PRESSURE SHOULD CROSS THE REGION FRIDAY
BRINGING WIDESPREAD CHANCES FOR SNOW SHOWERS. QPF SHOULD BE LIGHT
SINCE MOISTURE ASSOCIATED WITH THE FEATURES WILL BE FAIRLY LIMITED.
AS FOR TEMPERATURES LOOKING AT AROUND SEASONABLE LEVELS FOR EARLY
FEBRUARY. SHOULD WARM TO A BIT ABOVE NORMAL ON FRIDAY AHEAD OF THE
APPROACHING LOW PRESSURE SYSTEM.
NORMALS FEB 5TH-8TH:
ALBANY: HIGHS LOWER 30S. LOWS MID TEENS.
GLENS FALLS: HIGHS LOWER 30S. LOWS UPPER SINGLE DIGITS.
POUGHKEEPSIE: HIGHS UPPER 30S. LOWS UPPER TEENS.
BENNINGTON: HIGHS LOWER 30S. LOWS MID TEENS.
PITTSFIELD: HIGHS AROUND 30. LOWS MID TEENS.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
HIGHER PRESSURE OVER THE REGION THIS MORNING WILL WEAKEN AS A
CLIPPER LOW APPROACHES FROM THE GREAT LAKES. THE CLIPPER LOW IS
EXPECTED TO WEAKEN AS IT MOVES OVER THE REGION TONIGHT. THERE IS A
CHANCE OF SNOW SHOWERS FROM MID/LATE AFTERNOON THROUGH THE EVENING.
MAINLY VFR CONDITIONS ARE EXPECTED WITH MVFR POSSIBLE WITH ANY SNOW
SHOWERS. MVFR SHOULD DEVELOP AFTER MIDNIGHT.
SOUTH TO SOUTHWEST WINDS TODAY AHEAD OF THE APPROACHING CLIPPER LOW
BECOMING LIGHT AND VARIABLE TONIGHT.
OUTLOOK...
SUN...MAINLY VFR. SUB-VFR WITH CHC LIGHT SNOW MID TO LATE AFTN.
SUN NIGHT...MAINLY VFR. SUB-VFR WITH A LIGHT SNOW. AT KPSF SNOW
LIKELY AFTER MIDNIGHT.
MON-TUE...VFR. NO SIG WX.
TUE NIGHT. MAINLY VFR. CHC -SHSN MAINLY AFTER MIDNIGHT.
WED...MAINLY VFR. CHC -SHSN IN THE AM AND SLIGHT CHC IN THE AFTN.
&&
.HYDROLOGY...
THE NEXT 5 DAYS EXTENDING INTO THE MIDDLE OF NEXT WEEK WILL FEATURE
NO HYDRO PROBLEMS. COLD TEMPS AND LIGHT PCPN SYSTEMS /SNOW AS THE
PTYPE/ WILL ALLOW RIVERS AND STREAM TO CONTINUE TO RECEDE FROM
LAST WEEKS STORM SYSTEM.
THE BELOW NORMAL TEMPERATURES WILL ALLOW ICE TO REFORM AND THICKEN
ON BODIES OF WATER IN THE ALBANY HYDRO SERVICE AREA.
FOR SPECIFIC RIVER AND LAKE FORECASTS...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...FRUGIS/WASULA
NEAR TERM...FRUGIS/WASULA
SHORT TERM...WASULA
LONG TERM...IAA
AVIATION...IAA
HYDROLOGY...WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
641 AM EST SAT FEB 2 2013
.SYNOPSIS...
HIGH PRESSURE WILL BRIEFLY BUILD IN FROM SOUTHERN QUEBEC
THIS MORNING. A CLIPPER LOW WILL APPROACH FROM THE LOWER GREAT
LAKES REGION WITH ISOLATED TO SCATTERED SNOW SHOWERS LATE THIS
AFTERNOON INTO THIS EVENING. ANOTHER CLIPPER WILL IMPACT THE REGION
LATE SUNDAY INTO SUNDAY NIGHT WITH SOME LIGHT SNOW AND CONTINUED
BELOW NORMAL TEMPERATURES TO OPEN NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 640 AM EST...THE LAKE EFFECT SNOWS HAVE ENDED SOUTH AND WEST
OF THE CAPITAL REGION WITH JUST SOME ISOLD SNOW SHOWERS AND
FLURRIES AROUND...AS HIGH PRESSURE WILL BRIEFLY BUILD IN FROM SRN
QUEBEC THIS MORNING. A WEAK STATIONARY BOUNDARY OVER UPSTATE NY
AND NEW ENGLAND WILL LIFT BACK NORTHWARD AHEAD OF A WEAK LOW
PRESSURE SYSTEM OVER GEORGIAN BAY. SOME NEW LAKE EFFECT SNOW
SHOWERS HAVE REKINDLED OFF OF LAKE ONTARIO...AND ARE IMPACTING THE
TUG HILL PLATEAU AT 1130 UTC.
THE LOW AND MID LEVEL FLOW WILL CONTINUE TO BACK TO THE W/SW...AND
LAKE EFFECT SNOWFALL WILL BREAK OUT FURTHER OVER EXTREME NRN NY
OFF LAKE ONTARIO. A SW FLOW TRAJECTORY WILL NOT IMPACT THE ALY
FCST AREA MUCH. THE 240 DEGREE TRAJECTORY IS EXPECTED TO IMPACT
LOCATIONS JUST NORTH AND WEST OF THE WRN DACKS. THE LATEST ALY
HIRES WRF COMPOSITE REFLECTIVITY...AND 3-KM HRRR SHOW LITTLE
IMPACT IN OUR AREA TODAY. WE KEPT SOME HIGH CHC AND LIKELY POPS
NORTH OF OLD FORGE IN HERKIMER COUNTY...AND NW HAMILTON COUNTIES.
THERE IS SOME WEAK WARM ADVECTION WITH THE BOUNDARY TOO...SO SOME
SLIGHT AND LOW CHC POPS WERE EXPANDED SOUTH TO THE W-CNTRL MOHAWK
VALLEY.
ANOTHER CLIPPER LOW MOVING ACROSS WI/IL THIS MORNING WILL APPROACH
THE REGION FOR LATE THIS AFTERNOON...AND TONIGHT WITH SOME
SCATTERED SNOW SHOWERS OR LIGHT SNOW. THE SHORT-WAVE TO THIS
CLIPPER IS MOVING INTO THE MIDWEST THIS MORNING VIA THE WATER
VAPOR LOOP. CHC POPS WERE EXPANDED OVER MOST OF THE FCST AREA LATE
THIS AFTERNOON INTO EARLY THIS EVENING.
DESPITE WEAK LOW TO MID LEVEL WARM ADVECTION...H850 TEMPS WILL
STILL BE -12C TO -16C FROM SOUTH TO NORTH OVER THE CWA. EXPECT
HIGHS TO BE 5 TO 10 DEGREES BELOW NORMAL WITH HIGHS IN THE MID TO
U20S IN THE CAPITAL DISTRICT...THE MID HUDSON VALLEY...AND CT
VALLEY. EXPECT TEENS TO L20S OVER THE MTNS...LAKE GEORGE
REGION...W-CNTRL MOHAWK VALLEY...SRN VT...AND THE LITCHFIELD HILLS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
TONIGHT...THE FIRST OF TWO CLIPPERS PASSES SOUTH OF THE REGION
WITH SCT SNOW SHOWERS/LIGHT SNOW ENDING FROM NORTH TO SOUTH.
EXPECT MAINLY COATINGS TO A HALF AN INCH AROUND THE REGION.
PORTIONS OF THE ERN CATSKILLS...AND WRN ADIRONDACKS COULD SEE
AROUND AN INCH OR SO. THE FLOW VEERS TO THE W/NW AGAIN WITH THE
UPPER LEVEL TROUGH OVER CNTRL-ERN CANADA CONTINUING TO THE DRIVE
THE WX OVER NY AND NEW ENGLAND. MIN TEMPS WERE BLENDED FROM THE
MET/MAV GUIDANCE WITH SINGLE DIGITS NORTH OF THE CAPITAL
REGION...AND THE MOHAWK VALLEY...AND TEENS FROM THE I-90 CORRIDOR
SOUTH AND EAST.
SUNDAY-SUNDAY NIGHT...ANOTHER LULL IS BRIEFLY EXPECTED IN THE PARADE
OF SHORT-WAVES/CLIPPERS IN THE W/NW FLOW ALOFT SUNDAY MORNING. THE
GUIDANCE HAS TRENDED A BIT SLOWER WITH THE NEXT CLIPPER. SOME
SLIGHT CHC POPS WERE PUT IN DURING THE LATE MORNING WEST OF THE
HUDSON RIVER VALLEY...AND THEN CHC POPS WERE PUT IN EVERYWHERE IN
THE PM INTO THE EVENING. THIS CLIPPER AND ITS ASSOCIATED SHORT-
WAVE MOVE ACROSS THE CNTRL-ERN GREAT LAKES INTO THE REGION. THEIR
IS SOME PRONOUNCED CYCLONIC VORTICITY ADVECTION WITH IT. THE
DISTURBANCE WILL PRODUCE A ROUND OF LIGHT SNOW FOR THE REGION WITH
GENERALLY A DUSTING TO AN INCH OR SO IN MOST LOCATIONS. THE SHORT-
WAVE ENERGY WITH THIS CLIPPER WILL LIKELY PHASE WITH A STORM EAST
OF THE GULF OF MAINE SUNDAY NIGHT. THE STORM WILL INTENSIFY AND
DEEPEN NEAR THE CANADIAN MARITIMES. SOME WESTERLY UPSLOPE OR LAKE
EFFECT SNOWFALL MAY IMPACT THE SRN GREENS AND WRN DACKS. WE HAVE
1-4" OF SNOW SUNDAY TO SUNDAY NIGHT IN THESE AREAS. HIGHS WILL
RANGE FROM THE 20S TO L30S ACROSS THE REGION...TO SINGLE DIGITS TO
TEENS FOR LOWS.
MONDAY-MONDAY NIGHT...THE WORK WEEK WILL OPEN WITH BLUSTERY AND COLD
CONDITIONS...AS A DEEPENING AND INTENSIFYING LOW PRESSURE SYSTEM
MOVES TOWARD LABRADOR...AND ARCTIC HIGH PRESSURE BUILDS IN FROM
THE GREAT LAKES REGION AND ONTARIO. W/NW WINDS OF 15 TO 25 MPH
WILL BE COMMON WITH SOME GUSTS AROUND 30-40 MPH. WESTERLY UPSLOPE
SNOW SHOWERS OVER THE SRN GREENS AND WRN DACKS WILL END DURING THE
AFTERNOON WITH ADDITIONAL LIGHT ACCUMULATIONS. IN THE COLD
ADVECTION REGIME...H850 TEMPS FALL TO -17C TO -22C. MAX TEMPS WILL
CONTINUE TO RUN BELOW NORMAL WITH TEENS TO M20S OVER THE HILLS AND
MTNS...AND L20S TO L30S IN THE VALLEY AREAS. TEMPS MAY FALL DURING
THE AFTERNOON. DIMINISHING WINDS AND FRIGID CONDITIONS ARE
ANTICIPATED MON NIGHT WITH HIGH PRESSURE BUILDING IN WITH LOWS
BELOW ZERO OVER THE ADIRONDACK PARK...AND SRN GREENS...SINGLE
DIGITS EVERYWHERE ELSE...EXCEPT 10-15F IN THE MID HUDSON VALLEY
AND SRN LITCHFIELD COUNTY.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
MODEL GUIDANCE IS IN FAIRLY GOOD AGREEMENT KEEPING THE REGION UNDER
A LONGWAVE TROUGH. A SHORT WAVE IS FORECAST TO MOVE THROUGH THE BASE
OF THE TROUGH TUESDAY NIGHT INTO WEDNESDAY BRINGING THE THREAT FOR
SOME SNOW SHOWERS. THE FLOW ALOFT IS EXPECTED TO BECOME MORE ZONAL
WITH RIDGING BUILDING IN AT THE SURFACE AND IN THE LOW LEVELS OF THE
ATMOSPHERE FOR THURSDAY BETWEEN SHORT WAVES AS THE UPPER LOW OVER
EASTERN CANADA/HUDSONS BAY SHIFTS A BIT NORTHWARD. THE SURFACE HIGH
WILL WEAKEN AND SHIFT EASTWARD AS ANOTHER SHORT WAVE TROUGH
APPROACHES FROM THE GREAT LAKES THURSDAY NIGHT. THE UPPER TROUGH AND
ASSOCIATED SURFACE LOW PRESSURE SHOULD CROSS THE REGION FRIDAY
BRINGING WIDESPREAD CHANCES FOR SNOW SHOWERS. QPF SHOULD BE LIGHT
SINCE MOISTURE ASSOCIATED WITH THE FEATURES WILL BE FAIRLY LIMITED.
AS FOR TEMPERATURES LOOKING AT AROUND SEASONABLE LEVELS FOR EARLY
FEBRUARY. SHOULD WARM TO A BIT ABOVE NORMAL ON FRIDAY AHEAD OF THE
APPROACHING LOW PRESSURE SYSTEM.
NORMALS FEB 5TH-8TH:
ALBANY: HIGHS LOWER 30S. LOWS MID TEENS.
GLENS FALLS: HIGHS LOWER 30S. LOWS UPPER SINGLE DIGITS.
POUGHKEEPSIE: HIGHS UPPER 30S. LOWS UPPER TEENS.
BENNINGTON: HIGHS LOWER 30S. LOWS MID TEENS.
PITTSFIELD: HIGHS AROUND 30. LOWS MID TEENS.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
HIGHER PRESSURE OVER THE REGION THIS MORNING WILL WEAKEN AS A
CLIPPER LOW APPROACHES FROM THE GREAT LAKES. THE CLIPPER LOW IS
EXPECTED TO WEAKEN AS IT MOVES OVER THE REGION TONIGHT. THERE IS A
CHANCE OF SNOW SHOWERS FROM MID/LATE AFTERNOON THROUGH THE EVENING.
MAINLY VFR CONDITIONS ARE EXPECTED WITH MVFR POSSIBLE WITH ANY SNOW
SHOWERS. MVFR SHOULD DEVELOP AFTER MIDNIGHT.
SOUTH TO SOUTHWEST WINDS TODAY AHEAD OF THE APPROACHING CLIPPER LOW
BECOMING LIGHT AND VARIABLE TONIGHT.
OUTLOOK...
SUN...MAINLY VFR. SUB-VFR WITH CHC LIGHT SNOW MID TO LATE AFTN.
SUN NIGHT...MAINLY VFR. SUB-VFR WITH A LIGHT SNOW. AT KPSF SNOW
LIKELY AFTER MIDNIGHT.
MON-TUE...VFR. NO SIG WX.
TUE NIGHT. MAINLY VFR. CHC -SHSN MAINLY AFTER MIDNIGHT.
WED...MAINLY VFR. CHC -SHSN IN THE AM AND SLIGHT CHC IN THE AFTN.
&&
.HYDROLOGY...
THE NEXT 5 DAYS EXTENDING INTO THE MIDDLE OF NEXT WEEK WILL FEATURE
NO HYDRO PROBLEMS. COLD TEMPS AND LIGHT PCPN SYSTEMS /SNOW AS THE
PTYPE/ WILL ALLOW RIVERS AND STREAM TO CONTINUE TO RECEDE FROM
LAST WEEKS STORM SYSTEM.
THE BELOW NORMAL TEMPERATURES WILL ALLOW ICE TO REFORM AND THICKEN
ON BODIES OF WATER IN THE ALBANY HYDRO SERVICE AREA.
FOR SPECIFIC RIVER AND LAKE FORECASTS...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...WASULA
NEAR TERM...WASULA
SHORT TERM...WASULA
LONG TERM...IAA
AVIATION...IAA
HYDROLOGY...WASULA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
556 AM EST SAT FEB 2 2013
.UPDATE...
NOTEABLE 3HR PRES FALL MAX OVR NE IL/NW IN THIS MORNING W/COOLING IR
CLD TOPS NOTED WITHIN BURGEONING RADAR RTNS FM NE IL ACRS SRN LK MI
AND INTO SW MI. WHILE SNOW SHIELD HAS BEEN FAIRLY RAGGED SO FAR XPC
MORE ERSTWHILE DVLPMNT NR TERM IN LINE W/LATEST RUC DATA AND SEEN IN
UPSTREAM RADAR TRENDS. IN FACT NOTED BANDING TAKING PLACE OVR NE
IL/SRN LK MI ATTM W/WIDESPREAD 30DBZ+ RTNS NOTED AND INDICATIVE OF
SNOWFALL RATES NR 1 INCH PER HOUR.
WILL BUMP 12-18Z QPF/SNOW GRIDS SLIGHTLY ESP OVR BERRIEN COUNTY AS
SOME LK ENHANCMENT IS OCCURRING. OTRWS GIST OF PRIOR FCST HOLDS THIS
AFTN.
&&
.SHORT TERM...
TODAY THROUGH SUNDAY NIGHT...THE CHALLENGES THIS PERIOD INCLUDE A
NUMBER OF OPPORTUNITIES FOR SNOW INCLUDING A FAST MOVING CLIPPER
TYPE OF SYSTEM TODAY...LAKE EFFECT SNOW TONIGHT AND SUNDAY...AND A
SECOND FAST MOVING SYSTEM ARRIVING SUNDAY NIGHT OR MONDAY. FOR
THIS PACKAGE...FAVORED THE SRF. THE FIRST SYSTEM...THE LEFT EXIT
REGION OF UPPER JET WAS HELPING TO GENERATE SNOW OVER MUCH OF THE
FORECAST AREA EARLY THIS MORNING IN A VERY COLD AIRMASS LINGERING
OVER THE REGION. MOISTURE WAS LIMITED...BUT ISENTROPIC LIFT AND
SOME UPPER LEVEL JET SUPPORT WAS HELPING TO SUSTAIN THE SNOW. THE
ISENTROPIC LIFT SHOULD BE MOST FAVORABLE BETWEEN 09Z AND 15Z.
THEREFORE...WILL KEEP WIDESPREAD LIGHT SNOW ACCUMULATIONS
TODAY...WITH SNOW TAPERING THIS AFTERNOON. CURRENT THINKING IS
SNOW ACCUMULATIONS SHOULD BE AROUND AN INCH. FOR TONIGHT AND
SUNDAY... POOR LAKE EFFECT SNOW SET UP IN A HIGHLY SHEARED LOW
LEVEL ENVIRONMENT...ALTHOUGH DELTA T VALUES DO SUPPORT LAKE EFFECT
SNOW. LOW LEVEL SUBSIDENCE REALLY INCREASES LATER TODAY AND SHOULD
LIMIT SNOWFALL AND INTENSITY. REDUCED SNOW CHANCES CONSIDERABLY
ALL AREAS TONIGHT GIVEN LACK OF FORCING AND UPPER LEVEL SUPPORT
FOR WIDESPREAD SNOW. FOR THE SECOND CLIPPER SYSTEM...KEPT A CHANCE
FOR SNOW LATE SUNDAY NIGHT...WITH A MUCH BETTER CHANCE FOR SNOW
MONDAY AS ISENTROPIC LIFT INCREASES.
&&
.LONG TERM...
COLD PNA PATTN OF LATE ANCHORED BY DEEP POLAR TROUGH OVR HUDSON BAY
AND LW RIDGE ALG THE W COAST OF NOAM WILL RELAX THIS PD AS POLAR
TROUGH MIGRATES INTO BAFFIN BAY. RESULTING FLW PATTN WILL FLATTEN
OUT TO WRLY ACRS THE CONUS W/SIG WARMUP XPCD LT PD. UNTIL THEN HWVR
HAVE TO CONTEND W/CONTD PARADE OF SW RIPPLES EMBEDDED WITHIN STILL
FAIRLY STEEP NWRLY FLW ALOFT. 3RD SW OF NOTE WILL DIVE DOWN ACRS THE
SRN LAKES ON MON AND CONT TO FVR SRN CONSENSUS OF SOLUTIONS W/TRACK
OF THIS SW CNTRD OVR CNTRL IN. WHILE MSTR RTN AGAIN LIMITED...ROBUST
ISENTROPIC RESPONSE XPCD WITHIN ENTRANCE REGION OF UPR JET
COLLOCATED W/TIGHT BAROCLINIC ZONE. GIVEN PWS ARE A BIT BTR THAN NR
TERM SYS...XPCD SIMILAR EVOLUTION W/GENERAL 1-3 IN SNOWFALL ACRS THE
AREA...HEAVIEST CNTRL/SW. WILL BUMP POP SIGLY GIVEN GOOD INTERMODEL
AGREEMENT.
4TH SYS FOLLOWS QUICKLY LT TUE. HWVR PLACEMENT OF UPR JET AND
SOMEWHAT WEAKER RESPONSE ALOFT W/MORE LIMITED MSTR SUGGESTS MUCH
LIGHTER SNOW.
BEYOND THAT...FLW PATTN BREAKS DOWN W/WRN TROUGHING DVLPG TWD LT PD.
LEAD SYS BREAKING EWD OUT OF EPAC IN THIS TRANSITION WILL CROSS THE
AREA ON THU. EC/GFS SIMILAR IN SCOPE W/NARROW BUT IMPORTANT THETA-E
RIDGING DVLPG INADV AND IMPLY A POTENTIAL MIX FAR S/SW LT THU.
REGARDLESS SOME ENTRAINMENT OF FLEDGELING ERN GOMEX MSTR PLUME PSBL
AND WILL BRIDGE GOING POPS HIGHER.
&&
.AVIATION...
LEFT EXIT REGION OF UPPER JET AXIS HELPING TO GENERATE SNOW
UPSTREAM INTO NRN INDIANA IN VERY COLD AIRMASS LINGERING OVER THE
REGION. MOISTURE SOMEWHAT LIMITED...BUT VERY EFFICIENT SETUP TO
PRODUCE SNOW WITH VISIBILITIES DOWN TO 1 MILE. MADE SOME MAINLY
MINOR UPDATES TO THE ONGOING TAFS WITH THIS NEW ISSUANCE. VSBYS
SHOULD IMPROVE AFTER CLIPPER TYPE SYSTEM MOVES THROUGH...ALTHOUGH
EXPECT CIGS TO REMAIN MVFR.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 5 AM EST EARLY THIS MORNING FOR
LMZ043-046.
&&
$$
SHORT TERM...SKIPPER
LONG TERM...T
AVIATION...SKIPPER
UPDATE...T
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1013 AM EST SAT FEB 2 2013
.SYNOPSIS...
NORTHWEST FLOW WILL KEEP COLD AIR FUNNELING DOWN OVER THE MID
ATLANTIC STATES THROUGH WEDNESDAY. A SERIES OF WEAK LOW PRESSURE
SYSTEMS WILL QUICKLY PASS THROUGH THE REGION THROUGH WEDNESDAY.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
NEXT CLIPPER SYSTEM ON TRACK TO IMPACT THE REGION WITH LIGHT SNOW
STARTING THIS AFTERNOON AND CONTINUING THROUGH THE EVENING HOURS.
NOT MUCH IN THE WAY OF UPPER LEVEL DYNAMICS WITH THIS SYSTEM...SO
AM NOT EXPECTING ANYTHING OTHER A PERIOD OF LIGHT SNOW STARTING
DURING THE AFTERNOON AND ENDING LATE THIS EVENING. AT THE SURFACE...
HIGH PRESSURE OVERHEAD WILL MOVE EAST OF THE AREA THIS AFTERNOON
AHEAD OF THE CLIPPER LOW SYSTEM.
THE LATEST 12Z NAM SHOWS A FAIRLY DRY SYSTEM WITH ONLY LIGHT QPF
AMOUNTS OF LESS THAN 0.1 LIQUID...WTIH SNOW- LIQUID RATIOS OF 10
TO 12 TO ONE AS SHOWN BY THE 09Z/SREF. OTHER HI-RES MODELS ALL
AGREE ON TIMING THE SYSTEM ACROSS THE REGION THIS AFTERNOON AND
EVENING BUT DIFFER IN DETAILS OF SNOW AND ANY ATTENDANT SNOW
BANDING. THE 11Z 3KM HRRR IS TRENDING TO A WEAKER SYSTEM MOVING
THROUGH WITH LESS SNOWFALL POTENTIAL...WHEREAS THE 00Z 4KM NCEP
WRF NMM SHOWS A SLIGHTLY STRONG SYSTEM...ON A PAR WITH YESTERDAYS
CLIPPER.
CURRENT FORECAST HAD THE TIMING COVERED PRETTY WELL...AND I ONLY
MADE SOME MINOR ADJUSTMENTS TO THAT TIMING. FOR SNOWFALL AMOUNTS...
GIVING CURRENT SPEED OF THE CLIPPER...EXPECTING A 4 TO 6 HR PERIOD
WHERE OCCASSIONAL LIGHT SNOW WILL FALL. AIRMASS IS VERY DRY...
DULLES RAOB ONLY 0.18 INCHES...WITH FORECAST SOUNDINGS SHOWING AT
MOST 0.4 INCHES OF PRECIPITABLE WATER THIS AFTENROON AND EARLY
EVENING. DID NOT MAKE ANY CHANGES FOR CURRENT SNOW TOTAL GRAPHIC
FOR THE 930 AM UPDATE.
TEMPERATURES WILL BE UNSEASONABLY COLD TODAY MAINLY AT OR BELOW
FREEZING IN MOST LOCATIONS...AND AFTER LAST NIGHTS COLD READINGS
ANY SNOW THAT FALLS WILL STICK ON UNTREATED SURFACES.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH 6 PM SUNDAY/...
THE UPPER LEVEL WAVE/CLIPPER SYSTEM WILL BE SCOOTING OFF QUICKLY
TO THE EAST DURING THE EVENING HOURS...ENDING THE SNOW THREAT FOR
ALL AREAS...EXCEPT IN THE WESTERN UPSLOPE AREAS OF WESTERN
MD/VA/WV.
FOR SUN...ANOTHER UPPER LEVEL DISTURBANCE CLIPPER LIKE SYSTEM
APPROACHES THE REGION DURING THE MORNING AND CROSSES DURING THE
AFTERNOON HOURS. THIS SYSTEM HAS A LITTLE MORE IN THE WAY OF UPPER
DYNAMICS ASSOCIATED WITH IT...AND WOULD EXPECT TO SEE A BAND OR
TWO OF SNOW SHOWERS PASS ACROSS THE REGION DURING THE AFTERNOON
HOURS. TEMPS ON SUN EXPECTED TO BE 4 TO 6 DEGREES WARMER ON SUN.
ANY SNOW BANDS THAT COME THROUGH COULD PRODUCE A QUICK COATING OF
SNOW...BUT TEMPS SHOULD BE ABOVE FREEZING IN MOST AREAS. WILL
CONTINUE TO MONITOR.
PREVIOUS DISCUSSIONS FOLLOW.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
SUNDAY A SHEARED BUT POTENT SHORT WAVE WILL SLIDE EAST ACROSS THE
REGION...AND WE COULD SEE SOME SNOW SHOWERS WITH THAT. THE MAIN
THREAT WINDOW IS IN THE LATE MORNING THRU LATE AFTERNOON. ANY
ACCUM IS EXPECTED TO BE LESS THAN AN INCH...EXCEPT AROUND AN INCH
IN THE MOUNTAINS.
NEXT UP IS A CLIPPER MOVING EAST ACROSS THE MID ATLANTIC MONDAY
NIGHT WITH ANOTHER CHANCE AT A LIGHT ACCUMULATION. AND THIRD IS
ANOTHER CLIPPER PUSHING SOUTHEAST INTO NC WHICH BRINGS ANOTHER
CHANCE OF LIGHT ACCUMULATION ON TUESDAY NIGHT. THE GFS AND EURO
ARE IN GOOD AGREEMENT WITH THE TIMING OF BOTH OF THESE FEATURES
AND THEIR INTENSITIES.
AFTER THAT A SFC LOW IS SLATED TO CROSS TO OUR NORTH AND BRING A
COLD FRONT THROUGH US ON FRIDAY. BUT IT WILL NOT BE MUCH OF A COLD
FRONT AS RIDGING BUILDS IN QUICKLY BEHIND WITH MILDER TEMPS...AND
BASED ON THE LATEST WEEK TWO FORECASTS FROM THE NWS CLIMATE
PREDICTION CENTER...THOSE MILD TEMPS ARE EXPECTED TO DOMINATE THE
FOLLOWING WEEK.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
EXPECT A FEW PERIODS OF LIGHT SNOW TO DEVELOP THIS AFTERNOON AS
THE NEXT CLIPPER SYSTEM MOVES EAST. CIGS SHOULD DROP TO AROUND
3KFT AND VSBYS COULD LOWER BRIEFLY TO 1 TO 2 MILES. HAVE ADJST
TAFS TO REFLECT THIS. THE SNOW SHOULD BE SHORT-LIVED AND WILL BE
MOVING AWAY FROM THE AREA DURING THE 01-03Z TIMEFRAME THIS EVENING.
IFR CONDITIONS ARE POSSIBLE IN ANY SNOW SHOWERS ON
SUNDAY...AND AGAIN WITH SNOW SHOWERS WITH MON NIGHT AND TUE NIGHT
SHORT WAVES.
&&
.MARINE...
HIGH PRES TODAY WILL MOVE EAST IN ADVANCE OF THE CLIPPER SYSTEM.
WINDS COME AROUND TO S TO SW THIS AFTERNOON WITH A FEW 15 KT GUSTS
POSSIBLE. PERIODS OF LIGHT SNOW OVERSPREADING THE WATERS DURING
THE AFTERNOON BUT ENDING DURING THE MID EVENING HOURS.
ON SUN...ANOTHER UPPER LEVEL DISTURBANCE MOVES ACROSS THE WATER
DURING THE AFTERNOON. WINDS MAY INCREASE AFTER PASSAGE OF THIS
SYSTEM SUN AFTERNOON AND SMALL CRAFT ADV WINDS ARE EXPECTED SUNDAY
AFTERNOON INTO MONDAY AFTERNOON. THAT IS EXPECTED TO AGAIN BE THE
CASE ON WEDNESDAY AFTER THE CLIPPER.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 PM SUNDAY TO 3 PM EST MONDAY FOR
ANZ530>543.
&&
$$
SYNOPSIS...SMZ
NEAR TERM...SMZ
SHORT TERM...SMZ
LONG TERM...CAS
AVIATION...SMZ
MARINE...SMZ
AREA FORECAST DISCUSSION
NWS BISMARCK ND
422 AM CST SAT FEB 2 2013
.SHORT TERM...TODAY THROUGH SUNDAY...
THE MAIN HIGHLIGHTS OF THE SHORT TERM ARE STRONG WINDS AND LIGHT
ACCUMULATING SNOW THROUGH TONIGHT.
LIGHT SNOW CONTINUES ACROSS CENTRAL NORTH DAKOTA THIS MORNING AS
ANOTHER IMPULSE MOVES OVER THE AREA...WITH A SHARP GRADIENT ALONG
THE EASTERN PERIPHERY OF THE SURFACE ARCTIC HIGH PRESSURE TO THE
EAST. GUIDANCE FROM THE RAP AND 06Z NAM HAVE CAPTURED THIS
SCENARIO WELL THIS MORNING AND THUS HAVE DECIDED TO USE THEM AS A
GUIDE FOR THE CLIPPER SYSTEM THAT IS FORECAST TO MOVE OVER THE AREA
LATER THIS MORNING THROUGH THIS EVENING. THIS CLIPPER SYSTEM WILL
MOVE ALONG AND INTERACT WITH THE BAROCLINIC ZONE...GENERATING
ANOTHER ROUND OF LIGHT SNOW FOR CENTRAL AND EASTERN NORTH DAKOTA.
LIGHT SNOWFALL ACCUMULATIONS ARE EXPECTED AND GENERALLY AROUND AN
INCH NORTH AND EAST OF THE MISSOURI RIVER...WITH UP TO TWO INCHES
POSSIBLE FOR THE JAMES RIVER VALLEY.
LATER THIS MORNING...00Z GFS/NAM BUFR SOUNDINGS DEPICT LAPSE RATES
BECOMING NEARLY ADIABATIC ALLOWING FOR 45 KT H850 WINDS TO
BE MIXED DOWN TO THE SURFACE. COINCIDENT WITH STEEPENING LAPSE
RATES OVER THE AREA...MODEST ISALLOBARIC FORCING OF 6 MB SIX HOUR
PRESSURE RISES WILL MOVE OVER THE AREA. IF DOWNWARD MOMENTUM CAN
BE ACHIEVED...H850 WINDS WILL BE TRANSLATED DOWN TO THE
SURFACE...GENERATING WIDESPREAD GUSTS OF 45 KTS. MODELS ARE IN
GOOD AGREEMENT REGARDING THE OVERALL SEVERITY...BUT THERE IS SOME
DISAGREEMENT REGARDING TIMING. THE ECMWF SEEMS TO BE QUICK TO CUT
OFF THE STRONGEST WINDS BY 00Z...WITH OTHER MODELS HOLDING THE
STRONGEST WINDS THROUGH 03Z OVER THE SOUTHEAST. IN ADDITION TO
STRONG WINDS...AREAS OF BLOWING SNOW ARE POSSIBLE. THE STRONGEST WINDS
WILL NOT COINCIDE WITH THE HEAVIEST SNOWFALL...AND WILL BE FURTHER
HAMPERED BY ABOVE FREEZING TEMPERATURES ACROSS MUCH OF THE AREA.
HOWEVER...AREAS OF BLOWING SNOW AND REDUCED VISIBILITIES WILL BE
POSSIBLE FOR AREAS NORTH AND EAST OF THE MISSOURI RIVER...WHERE
THE HEAVIEST SNOWFALL TOTALS AND SUBFREEZING TEMPERATURES WILL BE
SEEN. AS A RESULT...HAVE DECIDED NOT TO ISSUE ANY ADVISORY
HEADLINES FOR BLOWING SNOW AND KEEP THE WIND ADVISORY AS IS EXCEPT
FOR THE SOUTHEAST WHERE IT HAS BEEN EXTENDED IN TIME.
.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...
THE MAIN FORECAST ISSUES IN THE LONG TERM PERIOD WILL BE A COUPLE OF
LIGHT SNOW EVENTS OVER THE NORTHEAST HALF OF THE FORECAST AREA.
NORTHWEST FLOW WILL BE IN PLACE ACROSS THE REGION AT THE BEGINNING
OF THE LONG TERM PERIOD. MODEL CONSENSUS CONTINUES TO SUPPORT A FEW
PERIODS OF SHORT WAVE ENERGY DIVING SOUTHEAST INTO THE STATE. HAVE
INCREASED POPS ACROSS THE NORTH AND EAST FOR SUNDAY
NIGHT...MONDAY...AND MONDAY NIGHT. THESE AREAS ARE FAVORED FOR
MINOR ACCUMULATIONS RANGING FROM A DUSTING TO AROUND TWO INCHES.
COMPLICATING FACTORS SUCH AS STRONG WIND AND BLOWING SNOW ARE NOT
EXPECTED. FORECAST BUFR SOUNDINGS CONTINUE TO INDICATE A MODEST WARM
LAYER ALOFT AND THE POTENTIAL FOR SOME SLEET AT TIMES ON THE BACK
EDGE OF THE PRECIP. UPPER FLOW WILL TRANSITION FROM ZONAL TO
SOUTHWEST...TUESDAY THROUGH FRIDAY. SOME ADDITIONAL LIGHT SNOW COULD
CLIP THE FAR NORTH WEDNESDAY...OTHERWISE EXPECT MAINLY DRY WEATHER
WITH RELATIVELY MILD AFTERNOON HIGHS IN THE 20S AND 30S.
&&
.AVIATION...
LOW PRESSURE WILL DROP SOUTHEAST ACROSS CENTRAL AND INTO SOUTHEAST
NORTH DAKOTA ON SATURDAY. LIGHT NORTH TO NORTHWEST WINDS WILL SHIFT
SOUTH TO SOUTHWEST LATE TONIGHT THEN BACK NORTHWEST ON SATURDAY
BEHIND THE SURFACE LOW. WINDS WILL BECOME GUSTY BY SATURDAY
AFTERNOON THEN DIMINISH BY SATURDAY EVENING. WIDESPREAD MVFR-IFR
CEILINGS AND VISIBILITIES WILL REMAIN OVER WESTERN AND CENTRAL NORTH
DAKOTA AHEAD OF THE APPROACHING SURFACE LOW. LOWEST VISIBILITIES IN
SNOW WILL REMAIN FROM MINOT TO JAMESTOWN ON SATURDAY...CLOSE TO THE
TRACK OF THE LOW. EXPECT IMPROVING CEILINGS SATURDAY EVENING FROM
WEST TO EAST.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 9 AM CST /8 AM MST/ THIS MORNING TO 6 PM CST
/5 PM MST/ THIS EVENING FOR NDZ001>003-009>011-017>021-031>035-
040>046.
WIND ADVISORY FROM NOON TODAY TO 6 PM CST THIS EVENING FOR
NDZ004-005-012-013-022-023-025-036-037-047-048-050-051.
&&
$$
SHORT TERM...HUBER
LONG TERM...KINNEY
AVIATION...HAMILTON
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
934 AM EST SAT FEB 2 2013
.SYNOPSIS...
A CLIPPER SYSTEM WILL TRACK EAST ACROSS THE GREAT LAKES AND OHIO
VALLEY THROUGH TONIGHT. A WEAK UPPER LEVEL WEATHER DISTURBANCE
WILL AFFECT THE REGION ON SUNDAY. HIGH PRESSURE WILL BUILD BRIEFLY
INTO THE OHIO VALLEY SUNDAY NIGHT. THE HIGH WILL MOVE EAST ON
MONDAY AS ANOTHER CLIPPER SYSTEM QUICKLY MOVES TOWARD THE OHIO
VALLEY FROM THE NORTHWEST.
&&
.NEAR TERM /THROUGH TONIGHT/...
SNOW HAS OVERSPREAD THE FORECAST AREA. NAM AND RAP MODELS HAVE
GOOD REPRESENTATIONS OF THE AREA OF SNOW. ACCUMULATIONS HAVE BEEN
UP TO AN INCH IN SOUTHWEST COUNTIES.
THE BEST ISENTROPIC LIFT WILL OCCUR AHEAD OF THE WEAK SFC LOW AND
FRONT. THUS...MUCH OF THE SNOW ACCUMULATION WILL OCCUR DURING THE
DAYLIGHT HOURS. THE SNOW WILL TAPER OFF FROM WEST TO EAST THIS
EVENING AS THE CLIPPER MOVES OFF TO THE EAST. USING A BLEND OF
MODEL QPF AND SNOW TO LIQUID RATIOS BASED ON TEMPERATURE...IT
STILL LOOKS LIKE A GOOD 2 TO 3 INCH SNOW EVENT AREA WIDE WITH
ISOLATED AMOUNTS NEAR 4 INCHES. A WINTER WEATHER ADVISORY WILL
REMAIN IN EFFECT THROUGH TONIGHT.
WITH LOW LEVEL WAA...HIGHS TODAY SHOULD RANGE FROM THE MID 20S
NORTH TO THE LOWER 30S SOUTH. IN CAA BEHIND THE DEPARTING
CLIPPER...OVERNIGHT LOWS SHOULD RANGE FROM THE MID TEENS
NORTHWEST TO THE LOWER 20S SOUTHEAST.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
OUR REGION WILL REMAIN UNDER A NORTHWEST FLOW PATTERN ALOFT
THROUGH THE SHORT TERM PERIOD. THIS PATTERN WILL ALLOW SEVERAL
WEATHER SYSTEMS TO AFFECT THE AREA.
ON SUNDAY...A SHEARED OUT WEAK UPR LVL WX DISTURBANCE WILL PASS
ACRS THE REGION. THIS FEATURE WILL KEEP SKIES MAINLY CLOUDY ALONG
WITH A CHANCE OF SNOW SHOWERS. THE WEAK DISTURBANCE WILL EXIT THE
AREA BY SUNDAY EVENING. DESPITE SURFACE HIGH PRESSURE BRIEFLY
BUILDING INTO THE OHIO VALLEY...CLOUDS WILL CONTINUE TO SPILL
SOUTHEAST FROM THE NEXT CLIPPER SYSTEM WHICH WILL LIMIT ANY
OPPORTUNITY TO CLEAR OUT.
FOR MONDAY INTO MONDAY NIGHT...MODELS ALL INDICATE THAT A CLIPPER
SYSTEM WILL TRACK SOUTHEAST THROUGH THE OHIO VALLEY. AM CONFIDENT
ENOUGH AT THIS POINT TO RAISE POPS TO LIKELY FOR MONDAY AFTERNOON
INTO MONDAY NIGHT. THERE CONTINUES TO BE STRENGTH ISSUES WITH THE
LOW AND ITS ASSOCIATED WAA/LOW LEVEL JET WHICH WILL ULTIMATELY
DICTATE PCPN TYPE AND SNOW ACCUMULATIONS. AT THIS POINT IT LOOKS
LIKE MUCH OF THE AREA NORTH OF THE OHIO RIVER WILL SEE SNOW WHILE
RAIN MAY MIX WITH SNOW ALONG AND SOUTH OF THE RIVER MONDAY
AFTERNOON INTO MONDAY EVENING UNTIL CAA CHANGES THE PCPN TO ALL
SNOW BEFORE TAPERING OFF LATE. AGAIN...WE SHOULD SEE SOME
ACCUMULATIONS BUT AMOUNTS ARE STILL UNCERTAIN AT THIS POINT DUE TO
REASONS JUST MENTIONED. WILL SPELL THIS OUT IN THE HWO PRODUCT.
LITTLE RESPITE IS EXPECTED TUESDAY INTO TUESDAY NIGHT AS ANOTHER
CLIPPER SYSTEM WILL BE ON THE HEELS OF THE MONDAY/MONDAY NIGHT
SYSTEM. THERE CONTINUES TO BE PLACEMENT ISSUES WITH THIS FEATURE
IN HOW FAR SOUTH IT WILL DIG. HAVE KEPT POPS IN THE CHANCE
CATEGORY UNTIL MODELS RESOLVE THIS DILEMMA. PCPN WILL BE IN THE
FORM OF SNOW NORTH WITH RAIN/SNOW POSSIBLE SOUTH.
AS FOR TEMPERATURES...THEY WILL BE HARD TO PINPOINT GIVEN SNOW
COVER AND SURFACE LOW PLACEMENT WITH THE UPCOMING CLIPPER SYSTEMS
WHICH WILL RESULT IN SFC WAA AHEAD OF THE LOW CENTER. MAINLY USED
A BLEND OF THE GFS/ECMWF SURFACE TEMPERATURES ALONG WITH
CLIMATOLOGICAL THICKNESS SCHEMES.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL BE IN PLACE ACROSS THE AREA FOR WEDNESDAY AND
WILL MOVE EAST OF THE FA ON THURSDAY. WITH SOUTHERLY FLOW ON
THURSDAY TEMPERATURES WILL RANGE FROM THE MIDDLE 30S TO THE MIDDLE
40S ACROSS THE REGION. PRECIPITATION WILL BEGIN TO MOVE INTO THE
FA THURSDAY EVENING AND BECOME MORE WIDESPREAD ACROSS THE AREA
THURSDAY NIGHT AS A COLD FRONT APPROACHES AND MOVES THROUGH THE
REGION. PRECIPITATION WILL TAPER OFF ACROSS THE FA DURING THE
MORNING HOURS ON FRIDAY AND HIGH PRESSURE WILL WORK BACK INTO THE
REGION FRIDAY AFTERNOON.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
SNOW IS NOW MOVING INTO THE TAF SITES...WITH VISIBILITIES QUICKLY
DROPPING INTO THE IFR CATEGORY JUST AFTER PRECIPITATION ONSET.
CEILINGS IN THE SNOW ARE ANYWHERE FROM VFR TO IFR...THOUGH IFR
CEILINGS HAVE BEEN FAIRLY UNCOMMON FOR THE PAST FEW HOURS. THE
TAFS WILL HANDLE THE BRUNT OF THE SNOW (OVER THE COURSE OF THE
NEXT 4-8 HOURS) WITH PREVAILING IFR VISIBILITIES AND LOW-END MVFR
CEILINGS IN A TEMPO. MVFR CEILINGS ARE EXPECTED TO BE THE RULE
LATER IN THE DAY...WITH LOW LEVEL MOISTURE FORECAST TO
INCREASE...EVEN AS THE STEADY PRECIPITATION COMES TO AN END. SNOW
SHOWERS LATER IN THE DAY MAY STILL BE CAPABLE OF BRIEF IFR
VISIBILITIES...BUT IN GENERAL MVFR CONDITIONS ARE EXPECTED.
AS SNOW TAPERS OFF DURING THE EVENING AND INTO THE OVERNIGHT
HOURS...VISIBILITIES SHOULD GO VFR...WITH SOME LOW CEILINGS
(GENERALLY MVFR) STILL REMAINING IN PLACE. HOWEVER...SOME
SCATTERING OF THE CLOUD DECK WILL BE EXPECTED.
OUTLOOK...MVFR CONDITIONS WILL CONTINUE TO BE POSSIBLE ON SUNDAY.
MVFR TO IFR CONDITIONS ARE EXPECTED AGAIN ON MONDAY AND MONDAY
NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WINTER WEATHER ADVISORY UNTIL 7 AM EST SUNDAY FOR OHZ026-034-
035-042>046-051>056-060>065-070>074-077>082-088.
KY...WINTER WEATHER ADVISORY UNTIL 7 AM EST SUNDAY FOR KYZ089>100.
IN...WINTER WEATHER ADVISORY UNTIL 7 AM EST SUNDAY FOR INZ050-058-
059-066-073>075-080.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...CONIGLIO/HICKMAN
SHORT TERM...HICKMAN
LONG TERM...NOVAK
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
429 PM EST SAT FEB 2 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 423 PM EST SAT FEB 2 2013
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW PERSISTENT DEEP
UPR TROF OVER E-CENTRL NAMERICA DOWNSTREAM OF HI AMPLITUDE UPR RDG
ALONG THE W COAST. SHRTWV EMBEDDED IN THE NW FLOW ALF PASSED OVER
THE UPR LKS THIS MRNG...BUT SHRTWV RDG/DNVA/DEEP LYR QVECTOR CNVGC
IN ITS WAKE IS DOMINATING THE CWA THIS AFTN. ALTHOUGH LES CONTINUES
IN THE NW WIND SN BELTS WITH H85 TEMPS NOT FAR FM -20C...THESE
NEGATIVE DYNAMICS THAT ARE DROPPING INVRN BASE TOWARD H9 PER RUC
ANALYSIS AND ARRIVAL OF LLVL ACYC FLOW AS WELL AS VERY DRY AIRMASS
UPWIND OF LK SUP /12Z PWAT AT INL AND YPL WAS ABOUT 0.06 INCH/ ARE
LIMITING THE INTENSITY/COVERAGE OF THE BANDS. FARTHER UPSTREAM...
THERE ARE TWO SHRTWVS DIGGING SEWD THRU THE NW FLOW ALF. THE FIRST
IS DIVING INTO THE NRN PLAINS. THE SECOND DISTURBANCE WHICH WL HAVE
A MORE DIRECT IMPACT IS HEADING SSEWD THRU NRN MANITOBA.
LATE TODAY/TNGT...AS SFC RDG AXIS IN THE WAKE OF DEPARTING SHRTWV
PASSES SEWD THRU THE FA THIS EVNG...WINDS WL BACK STEADILY TO THE SW
THRU THIS EVNG. LINGERING LES BANDS WL BE SHIFTING STEADILY WITH THE
FLOW...AND IN CONCERT WITH MORE ACYC FLOW/LOWERING INVRN BASE LIMIT
ANY ADDITIONAL SN ACCUMS. MEANWHILE...FIRST UPSTREAM SHRTWV IS
PROGGED TO HEAD SEWD THRU THE UPR MS RIVER VALLEY. SINCE THE SHARPER
DPVA/DEEP LYR QVECTOR CNVGC/DEEPER MSTR WL PASS TO THE SW OF THE WI
BORDER...EXPECT THE BULK OF ANY ACCOMPANYING PCPN TO REMAIN IN WI
EVEN THOUGH SOME CLDS WL ARRIVE. AREA OF SHARPER DPVA/QVECTOR CNVGC/
MSTR ASSOCIATED WITH 2ND SHRTWV WL ARRIVE AFT MIDNGT. DRYNESS OF
AIRMASS WL LIMIT ANY LARGER SCALE PCPN...BUT ARRIVAL OF ACCOMPANYING
LO PRES TROF OVER THE NW ZNS LATE/WSHFT TO THE W-NW THAT WL BRING
ABOUT SOME LK ENHANCEMENT IN THE PRESENCE OF H85 TEMPS ARND -18C/
DEEP MSTR JUSTIFIES GOING CATEGORICAL POPS IN THAT AREA. SINCE 12Z
NAM FCST PROFILE FOR CMX SHOWS UVV MAX WITHIN DENDRITIC SN GROWTH
LYR...THERE MAY BE A PERIOD OF HEAVY SHSN JUST BEFORE 12Z THAT
COINCIDES WITH THE ARRIVAL OF THE TROF/SHARPER LLVL CNVGC. AS FOR
TEMPS...EXPECT READINGS TO FALL OFF RATHER QUICKLY THIS EVNG TOWARD
THE LOWER END OF GUIDANCE BUT THEN FALL ONLY SLOWLY OR PERHAPS RISE
WITH ARRIVAL OF MORE CLDS.
SUN...2ND SHRTWV IS FCST TO TRACK THRU LK SUP/ADJOINING ONTARIO ON
SUN MRNG...WITH ATTENDANT SFC TROF/WSHFT TO THE NW SWINGING ACRS THE
ERN CWA IN THE 15Z-18Z TIME. IN ITS WAKE...DNVA/LARGER SCALE QVECTOR
DVGC WL DOMINATE...DROPPING INVRN BASE OVER THE W TO 4-5K FT BY 18Z
BUT NOT OVER THE E UNTIL NEAR 00Z. SINCE THE INCOMING AIRMASS WL BE
QUITE CHILLY WITH H85 TEMPS PROGGED TO FALL AS LO AS -23C OVER THE W
LATE IN THE DAY...RATHER SHORT FETCH LENGTH OVER THE W HALF OF LK
SUP...SHORTENED EVEN FURTHER BY RECENT ICE BUILDUP ALONG THE W SHORE
OF THE CWA...WL LIMIT LK MODERATION. WITH THE DGZ CONFINED TO ONLY A
SHALLOW NEAR SFC LYR...EXPECT SMALL SN FLAKE SIZE AND RATHER LIMITED
SN ACCUMS AFT THE PASSAGE OF THE TROF/HEAVIER SN BAND EARLY. EVEN
THOUGH H925 NW WINDS IN THE WAKE OF THE TROF ARE FCST TO BE NO HIER
THAN ABOUT 25KT WHICH WOULD TEND TO LIMIT THE MAGNITUDE OF ANY
BLSN...PRESENCE OF SN COVERED ICE OFFSHORE WL LIKELY ENHANCE THE
VSBY RESTRICTION. FOR THE W...OPTED TO GO WITH AN LES ADVY FOR
ONTONAGON/HOUGHTON/KEWEENAW COUNTIES BEGINNING AT 09Z AND EXTENDING
THRU THE DAY. FOR AREAS E OF MQT...EXPECT A PERIOD OF HEAVIER SHSN
TO DVLP IN THE MRNG WITH PASSAGE OF TROF AND THEN MORE SUSTAINED
HEAVIER SHSN IN PREVAILING NW FLOW THRU THE AFTN. FCST PROFILE SHOW
DEEPER DGZ MAINTAINED BY MORE LK MOISTENING WL CAUSE BIGGER SN
FLAKES/HIER SN ACCUMS THAN OVER THE W. FOR ALGER/NRN SCHOOLCRAFT/
LUCE COUNTIES...OPTED TO BEGIN LONG DURATION LES WRNG AT 15Z. OVER
THE CENTRAL ZNS WITH DOWNSLOPE FLOW/LIMITED ABSOLUTE MSTR...THERE
WL BE NOTHING MORE THAN ISOLD-SCT -SHSN ASSOCIATED WITH THE TROF
PASSAGE.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 423 PM EST SAT FEB 2 2013
UPPER TROUGH AXIS CENTERED OVER NORTHER HUDSON BAY FORECAST TO OPEN
UP AND LIFT FARTHER NORTH INTO NUNAVUT CANADA. RESULT IS TROUGH AND
COLD AIR OVER GREAT LAKES TO BEGIN THE PERIOD EASES MID-LATE WEEK.
BY NEXT WEEKEND...HEIGHTS AND TEMPS ARE ON THE RISE OVER MUCH OF
EASTERN CONUS OUT AHEAD OF DEEPENING TROUGH OVER SOUTHWEST CONUS.
MEDIUM RANGE MODELS /GFS/ECMWF/GEM-NH/UKMET/ IN GREAT AGREEMENT
WITH LARGER SCALE PATTERN THROUGH NEXT WEEK...LEADING TO HIGHER THAN
NORMAL CONFIDENCE FOR MUCH OF THE FORECAST.
NORTHWEST FLOW ALOFT KEEPS COLD AIR IN OVER THE AREA THROUGH AT
LEAST MIDWEEK. INITIAL CONCERN WILL BE NEXT ROUND OF MODERATE TO
HEAVY LK EFFECT SNOWS THAT KICK OFF ON SUNDAY. NW FLOW AREAS IN LINE
TO SEE THE MOST SNOW. IN THE WEST...SHORTER OVER-WATER FETCH RESULTS
IN LOWER INVERSION HEIGHTS AROUND 5KFT AND LESS LAKE INDUCED CAPE.
TEMPS MAINLY BLO -20C IN THE LK EFFECT CONVECTIVE LAYER POINT TO NOT
AS MUCH FOR SNOW ACCUMULATION BUT GIVEN SMALL SNOWFLAKE SIZE THE
VSBY WILL BE POOR IN ANY SNOW SHOWERS. AS MENTIONED IN SHORT TERM
DISCUSSION...BLSN/DRSN MAY NOW BE MORE OF ISSUE ALONG SHORE DUE TO
THE ICE BUILDUP IN LAST FEW DAYS. BTWN THE VSBY ISSUES AND MODERATE
SNOW...WILL CARRY LK EFFECT SNOW ADVY THROUGH DAYBREAK ON MONDAY.
HEAVIER SNOW EXPECTED OVER THE EAST...ESPECIALLY FROM MUNISING EAST
ACROSS THE FAVORED SNOWBELTS NORTH OF M-28 TO THE NORTH OF NEWBERRY.
UNLIKE THE WEST...MUCH LONGER OVER-WATER FETCH RESULTS IN INVERSION
HEIGHTS TO 8KFT AND LAKE INDUCED CAPES NEAR 700J/KG. ALSO UNLIKE THE
WEST...MORE OF THE DGZ IS WITHIN THE LAKE EFFECT LAYER...LEADING TO
HIGHER SLR/S OVER 25:1. KEY FOR THE HEAVY SNOW WILL BE WHERE
STRONGEST CONVERGENCE SETS UP SUNDAY NIGHT THROUGH MONDAY MORNING.
UNFORTUNATELY STILL SOME DESCREPANCY HERE...WITH REGIONAL-GEM AND
GFS OVER LUCE COUNTY WHILE NAM AND NCEP WRF-ARW ALONG WITH LOCAL WRF
ARE FARTHER WEST MORE INTO ALGER COUNTY. NOTICED THAT NAM SFC
CONVERGENCE IS FARTHER WEST COMPARED TO H95 CONVERGENCE. SFC
CONVERGENCE PEGGED WESTERN EDGE OF LK EFFECT TODAY FAIRLY WELL...SO
FOLLOWED THAT IDEA FOR POPS. KEPT HIGHER SNOW IN THE SNOWBELTS OF
EASTERN ALGER COUNTY THROUGH NORTHERN LUCE COUNTY. FOR THOSE AREAS
SNOW AMOUNTS OF 5-7 INCHES ARE EXPECTED SUNDAY NIGHT WITH ADDITIONAL
3-6 INCHES ON MONDAY. CERTAINLY POSSIBLE THAT MODERATE SNOW AMOUNTS
MAY FALL AS FAR WEST AS AU TRAIN/MUNISING AS WELL...ESPECIALLY IF
THE FARTHER WEST CONVERGENCE CAMP OF MODELS IS CORRECT. LK EFFECT
SNOW WARNING STARTS UP ON SUNDAY AND WILL JUST RUN IT ALL THE WAY
THROUGH MONDAY AS BLYR WINDS DO NOT REALLY BACK MORE WNW UNTIL LATER
MONDAY AFTN. LINGERED HIGHER POPS FOR SNOW SHOWERS EAST OF MUNISING
ON MONDAY NIGHT...BUT INVERSIONS LOWERING BLO 5KFT SHOULD BEGIN TO
TAKE TOLL ON INTENSITY OF LK EFFECT.
AWAY FROM THE LK EFFECT COLD WILL BE MAIN STORY. LGT WINDS AND DRY
AIRMASS LEADS TO POTENTIAL FOR MIN TEMPS WELL BLO ZERO SUNDAY NIGHT.
MAX TEMPS MONDAY LIKELY ONLY STRUGGLE INTO LOWER TEENS ABOVE ZERO.
ONCE THE LK EFFECT SUBSIDES LATER MONDAY NIGHT...ATTN IS ON
APPROACHING CLIPPER SHORTWAVE/PV ANAMOLY DIVING IN FROM NORTHERN
PLAINS. NAM APPEARS FARTHER NORTH WITH TRACK OF WAVE...RESULTING IN
STRONGER MOISTURE TRANSPORT/WARM AIR ADVECTION INTO NORTHERN WI/UPR
MICHIGAN. GFS/GEM-NH/ECMWF FARTHER SOUTH WITH ALL THE FORCING AND
ONLY GLANCE UPR MICHIGAN WITH SYSTEM SNOW. SEEMS THAT SHORTWAVE
WOULD TEND TO DIG FARTHER SOUTH GIVEN DOWNSTREAM TROUGHING OVER THE
EASTERN CONUS. MODELS HAVE BASICALLY BEEN CONSISTENT IN KEEPING
SYSTEM TO THE SOUTH AND THOUGH 12Z GFS DID JOG NORTH SOME...THE 12Z
ECMWF IS KEEPING TRACK TO THE SOUTH. EVEN WITH A DIRECT HIT FROM
SYSTEM...LACK OF AVAILABLE MOISTURE WITH PWATS JUST SHY OF NORMAL
AND H7 MIXING RATIOS NOT EVEN 2G/KG...WOULD KEEP SNOW AMOUNTS TO AN
INCH OR TWO. BIGGER IMPACT IS DOWNSTREAM OF LK MICHIGAN IN EASTERN
CWA...WHERE OVER-WATER INSTABILITY WOULD BE PRESENT WITH H85 TEMPS
BLO -10C COMBINING WITH THE LARGER SCALE LIFT FROM SYSTEM MAYBE
COULD HELP GENERATE ADVY LEVEL SNOWS.
NEXT CLIPPER MOVING THROUGH WEDNESDAY NIGHT INTO THURSDAY SEEMS TO
HAVE BETTER SHOT AT IMPACTING MUCH OF UPR MICHIGAN WITH SNOW. THOUGH
SFC LOW TRACKS WELL TO SOUTH ACROSS IA AND SOUTHERN WI...H85 TROUGH
IS FARTHER NORTH AND ALLOWS TEMP/MOISTURE ADVECTION INTO UPR
MICHIGAN. TEND TO THINK HEAVIER QPF WILL END UP SOUTH OF CWA THOUGH
AS RIGHT ENTRANCE REGION OF JET PLACES BETTER UPR DIVERGENCE SOUTH
OF UPR MICHIGAN. EVEN SO...WIDESPREAD SNOW OF 1-3"/2-4" COULD OCCUR
ACROSS CWA INTO THURSDAY. MAYBE SOME LK EFFECT ON THE BACKSIDE OF
THE TROUGH BUT TEMPS ARE MODERATING BY THIS TIME AS H85 TEMPS ARE
ONLY DOWN TO AROUND -13C. CONTINUING MODERATION ON FRIDAY AND
SATURDAY RESULTING IN LK EFFECT TO SHUT DOWN AND HIGH TEMPS BOTH
FRIDAY AND SATURDAY POSSIBLY EXCEEDING 30 DEGREES. NEXT TROUGH AND
SNOW CHANCES ARRIVES LATER IN THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1221 PM EST SAT FEB 2 2013
CMX...EXPECT IFR/MVFR CONDITIONS IN -SHSN THRU THIS AFTN TO GIVE WAY
TO VFR CONDITIONS WITH WSHFT TO THE SW THIS EVNG. AS ANOTHER UPR
DISTURBANCE/SFC TROF APRCH OVERNGT...MORE -SN/MVFR CONDITIONS WL
PREDOMINATE AFT 06Z. AS THE TROF PASSES TOWARD 12Z...EXPECT A PERIOD
OF HEAVIER SHSN WITH LIFR CONDITIONS FOR AT LEAST A COUPLE OF HRS.
FOLLOWING THE PASSAGE OF THE TROF/HEAVIER SHSN...IFR CONDITIONS WL
THEN LINGER THE REST OF THE TAF PERIOD WITH LES/SMALL SN FLAKES/SOME
BLSN EFFECTIVELY REDUCING VSBY.
IWD...VFR CONDITIONS THRU THIS EVNG WL GIVE WAY TO SOME -SN/MVFR
CONDITIONS LATE TNGT WITH APRCH OF DISTURBANCE/LO PRES TROF. IFR
CONDITIONS WL THEN ACCOMPANY THE PASSAGE OF THE TROF AND THEN
PERSIST AS LES SETS UP IN THE WAKE OF THE PASSAGE WITH WSHFT TO NW.
SAW...EXPECT VFR CONDITIONS TO PREDOMINATE THRU TNGT WITH DOWNSLOPE
NW FLOW BACKING TO THE WSW AHEAD OF APRCHG LO PRES TROF. SOME MVFR
CIGS MAY IMPACT THIS SITE FOLLOWING THE PASSAGE OF THE TROF ON SUN
MRNG AS VERY COLD AIR SURGES BACK INTO THE AREA.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 423 PM EST SAT FEB 2 2013
WSW WINDS UP TO 25 KTS WILL VEER NW LATE TONIGHT/SUN MORNING IN THE
WAKE OF A LO PRES TROF PASSAGE. AS ANOTHER VERY COLD AIRMASS POURS
OVER THE LAKE AND NW WINDS INCREASE UP TO 30 KTS...EXPECT HEAVY
FREEZING SPRAY TO DEVELOP OVER THE W AND CENTRAL ON SUN AND TO
CONTINUE OVER MUCH OF THE LAKE THROUGH MONDAY. WINDS DIMINISH BLO 25
KTS BY TUESDAY. EXPECT A COUPLE OF CLIPPER SYSTEMS TO MOVE ACROSS THE
UPPER GREAT LAKES THE REST OF THE WEEK...BUT WINDS SHOULD STAY MAINLY
BLO 30 KTS. GRADUALLY WARMING TEMPERATURES WILL END THE POTENTIAL FOR
FREEZING SPRAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 4 AM SUNDAY TO 7 AM EST MONDAY
FOR MIZ001>003-084.
LAKE EFFECT SNOW WARNING FROM 10 AM SUNDAY TO 7 PM EST MONDAY
FOR MIZ006-007-085.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WATCH FROM SUNDAY EVENING THROUGH MONDAY
MORNING FOR LSZ249>251-266-267.
HEAVY FREEZING SPRAY WARNING FROM 1 PM SUNDAY TO 7 AM EST MONDAY
FOR LSZ248-265.
HEAVY FREEZING SPRAY WARNING FROM 1 AM SUNDAY TO 7 AM EST MONDAY
FOR LSZ244-245-264.
HEAVY FREEZING SPRAY WARNING FROM 1 AM EST /MIDNIGHT CST/ SUNDAY
TO 1 AM EST /MIDNIGHT CST/ MONDAY FOR LSZ241>243-263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...KC
MARINE...KC/JLA
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
317 PM CST SAT FEB 2 2013
.SHORT TERM...
MAIN ISSUE WILL BE SNOW AND BLOWING SNOW LATE THIS AFTERNOON AND
EVENING.
SAT LOOP AND 500MB ANALYSIS SHOW THE CLIPPER SHORTWAVE MOVING
THROUGH CENTRAL ND...WITH A FAIR AMOUNT OF SNOW ACROSS MUCH OF THE
VALLEY. BEST RADAR RETURNS HAVE BEEN FROM VALLEY CITY TOWARDS
FARGO...AND WEBCAMS SHOW SOME LIGHT ACCUMULATIONS. A FEW OBS SITES
THIS MORNING WENT DOWN TO 1/4SM VIS BRIEFLY AS HEAVIER SNOW BANDS
MOVED OVER THEM...BUT QUICKLY IMPROVED WHEN SNOW BECAME LESS
INTENSE. OF GREATER IMPACT TO THE PUBLIC WILL BE THE WINDS ON THE
BACKSIDE OF THE SFC LOW CURRENTLY NEAR THE JAMESTOWN AREA. WINDS
HAVE SHIFTED TO THE NORTHWEST BEHIND THE LOW AND MANY HAVE
INCREASED INTO THE 25 TO 35 KT RANGE. THERE HAS BEEN QUITE A BIT
OF BLOWING SNOW AND NEAR ZERO VISIBILITIES IN THE WESTERN PART OF
THE STATE.
TRAJECTORY OF THE SFC LOW AND THE HIGH MSLP FALL/RISE
COUPLET WOULD HAVE THE HIGHEST WINDS MAINLY IMPACTING OUR WESTERN
AND SOUTHERN COUNTIES. RAP HAS HAD A DECENT HANDLE ON THE SFC
WINDS IN THE WEST SO HAVE FOLLOWED IT FAIRLY CLOSELY. MODEL
SOUNDINGS SHOW THE BEST CHANCES FOR GOOD MIXING TO THE SFC WILL BE
MAINLY OVER THE FAR SOUTHWEST COUNTIES. WINDS HAVE ALREADY SHIFTED
TO THE WEST IN WESTERN BENSON COUNTY AND SHOULD START BLOWING IN
THE NEXT HOUR OR TWO. RADAR ESTIMATES SHOW A COUPLE OF INCHES OF
FRESH ACCUMULATION FROM KDVL DOWN TOWARDS THE SOUTHERN VALLEY.
WITH FRESH SNOW...BLOWING SNOW AND REDUCED VIS WILL BE A PROBLEM.
WITH THE WORST OF THE SFC WINDS JUST MOVING BY TO OUR SOUTH AND
WEST...FOR NOW JUST INCLUDED THE HIGHER TERRAIN OF THE DEVILS LAKE
DOWN TO RANSOM/SARGENT COUNTIES...ALONG WITH RICHLAND AND WILKEN
COUNTIES. WILL HAVE TO WATCH FAR WESTERN CASS COUNTY FOR BLOWING
SNOW BUT FOR NOW WILL LEAVE FARGO OUT OF IT AS IT SEEMS THAT THE
WORST WINDS WILL MISS THEM. WINDS SHOULD START TO COME DOWN BY MID
EVENING IN THE DEVILS LAKE BASIN AND AROUND 06Z FURTHER SOUTH.
THE SHORTWAVE WILL MOVE QUICKLY OFF TO THE EAST TONIGHT...WITH
WINDS TAPERING OFF AND A WEAK SFC HIGH MOVING IN BY MORNING.
DEPENDING ON THE AMOUNT OF CLEARING BY MORNING...THERE COULD AGAIN
BE TEMPERATURES IN THE TEENS BELOW ZERO AND WIND CHILL VALUES
APPROACHING ADVISORY CRITERIA IN THE NORTH BY THE EARLY MORNING
HOURS. HOWEVER...WITH THE ONGOING WSW FOR BLOWING SNOW AND THE
UNCERTAINTY OF CLOUDS WILL LEAVE OUT FOR NOW.
ANOTHER WEAK SHORTWAVE WILL BEGIN TO DIG INTO THE WESTERN DAKOTAS
SUNDAY...WITH ANOTHER WEAK SFC LOW DEVELOPING TO THE SOUTHWEST OF
THE CWA. MODELS HAVE BEEN TRENDING FURTHER SOUTH AND WEST SO KEPT
HIGHEST POPS FROM THE DEVILS LAKE BASIN TOWARDS THE LAKES COUNTRY FOR
SUNDAY INTO SUNDAY NIGHT. TIGHT TEMP GRADIENT REMAINS OVER THE
NORTHERN PLAINS BUT THINK THAT ARCTIC AIR WILL REMAIN IN PLACE
OVER MOST OF THE REGION SO KEPT HIGHS MAINLY IN THE SINGLE DIGITS
WITH SOME TEENS IN THE WEST. THERE SHOULD BE A REINFORCING SURGE
OF COLD AIR SUNDAY NIGHT WHICH WILL HELP KEEP LOWS MOSTLY BELOW
ZERO.
ANOTHER WEAK CLIPPER SYSTEM WILL BEGIN TO MOVE INTO SOUTHERN
CANADA BY MONDAY...BRINGING ANOTHER ROUND OF PRECIP INTO OUR
NORTHWESTERN CWA BY MONDAY AFTERNOON. TEMPS SHOULD REMAIN BELOW
AVERAGE. THE PARADE OF WEAK SHORTWAVES WILL CONTINUE INTO MONDAY
NIGHT AND TUESDAY. THERE ARE SOME DIFFERENCES IN THE TRACK OF THE
MONDAY NIGHT/TUESDAY LOW...BUT OVERALL THIS SYSTEM SEEMS A BIT
FURTHER NORTH AND EAST THAN THE PREVIOUS FEW SYSTEMS. STILL PRETTY
UNCERTAIN SO INCLUDED JUST HIGH CHANCE POPS FOR NOW BUT WILL
PROBABLY NEED TO BUMP UP. THERE SHOULD BE A DECENT AMOUNT OF WARM
AIR ADVECTION AND SOME WARMER AIR GETTING INTO AT LEAST THE
SOUTHWESTERN CWA. STARTED BRINGING LOWS IN THE TEENS INTO THE WEST
MONDAY NIGHT AND HIGHS UP INTO THE TEENS TO 20S FOR TUESDAY.
.LONG TERM (TUE NIGHT-SAT)...
NORTHWEST FLOW ALOFT WILL GRADUALLY TRANSITION MORE TO A ZONAL FLOW
AND THEN BY LATE IN THE PERIOD...BRIEF RIDGING FOLLOWED BY SOUTHWEST
FLOW. MODELS SEEM PRETTY CONSISTENT IN DEPICTING ANOTHER SHOT OF
LIGHT SNOW MAINLY ACROSS THE NORTHERN FA ON WED/WED NIGHT. THURSDAY
AND FRIDAY SHOULD BE QUIET WITH MILDER AIR MOVING BACK INTO THE
AREA. STILL LOOKING TO TURN A LITTLE MORE ACTIVE AGAIN BY SATURDAY
IN THE SOUTHWEST FLOW WITH A COLORADO LOW TAKING SHAPE. AT THIS
POINT THIS SYSTEM WOULD AFFECT THE SOUTHERN FA MORE THAN THE NORTH
BUT IT IS A LONG WAYS OFF YET. WILL HAVE TO SEE WHAT FUTURE MODEL
RUNS HAVE IN STORE FOR THIS SYSTEM.
&&
.AVIATION...
THE BAND OF LIGHT SNOW LOOKS LIKE IT WILL MOVE THROUGH THE AREA
QUICKLY THIS AFTERNOON ONLY BRINGING AN HOUR OR SO OF LOWER VSBYS
BEFORE SHIFTING OFF TO THE SOUTHEAST. THE MAIN QUESTION FOR THE TAFS
IS WHETHER THE GUSTY WINDS WHICH ARE CURRENTLY WEST OF THE FA MAKE
IT INTO THE RED RIVER VALLEY TONIGHT AND CAUSE ANY REDUCTION TO VBSY
DUE TO BLOWING SNOW. BROUGHT WINDS UP AND INSERTED SOME BLOWING SNOW
WITH THE WORST CONDITIONS AT KFAR. WINDS SHOULD DIE DOWN LATER IN
THE EVENING.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR NDZ006-
007-014-015-024-026-028-054.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR NDZ038-
049-052-053.
MN...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ029.
&&
$$
JR/GODON
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1006 AM CST SAT FEB 2 2013
.DISCUSSION...
MADE SOME MINOR TWEAKS TO POPS/WX FOR SNOW AS THE CLIPPER SYSTEM
MOVES THROUGH THE AREA. OBS SHOW SOME -SN HAS STARTED IN THE
SOUTHWESTERN CWA...ALTHOUGH NOTHING ACCUMULATING SO FAR. NAM AND
RAP SHOW THE BEST PRECIP CHANCES WILL BE WITH THE MAIN SHORTWAVE
COMING THROUGH THIS AFTERNOON...WITH THE BEST CHANCES FOR
1 TO 2 INCHES OF SNOW STRETCHING SOUTHEASTWARD FROM NORTH CENTRAL
ND TOWARDS LAKES COUNTRY. MOST OF THE HIGHER WINDS THIS AFTERNOON
WILL BE TO OUR WEST...BUT THE FAR WESTERN TIER OF COUNTIES COULD
GET FAIRLY BREEZY LATE THIS AFTERNOON AND EVENING BEHIND THE SFC
LOW. INCLUDED A PATCHY BLOWING SNOW MENTION FOR A FEW HOURS...NO
HEADLINES BUT WILL KEEP AN EYE ON THINGS. ADJUSTED TEMPS A BIT AS
READINGS HAVE BEEN A BIT SLOW TO WARM IN THE BITTERLY COLD
NORTHEASTERN COUNTIES...BUT KEPT HIGHS IN THE SINGLE DIGITS TO
NEAR 20 IN THE FAR SOUTHWEST.
&&
.AVIATION...
VFR/MVFR CEILINGS WILL INCREASE FROM WEST TO EAST THROUGH THE DAY AS
A LOW PRESSURE SYSTEM MOVES ACROSS THE REGION. SOME LIGHT SNOW IS
POSSIBLE FOR AIRFIELDS ALONG AND WEST OF THE VALLEY AFTER 15 UTC.
SNOW SHOULD BE LIGHT...BUT SOME REDUCTIONS IN VISIBILITY LESS THAN
ONE MILE ARE POSSIBLE. LIGHT SOUTH-SOUTHWEST WIND THROUGH THE DAY
WILL INCREASE AND SHIFT TO THE NORTHWEST THIS EVENING AND
OVERNIGHT.
&&
.PREV DISCUSSION... /ISSUED 400 AM CST SAT FEB 2 2013/
SHORT TERM...TODAY THROUGH MONDAY NIGHT
MAIN FORECAST CHALLENGES INCLUDE LIGHT SNOW CHANCES AND TEMPERATURES.
GFS/NAM/ECMWF/GEM IN GOOD AGREEMENT AND WILL USE A BLENDED SOLUTION
FOR THIS FORECAST PACKAGE.
FOR TODAY...A CLIPPER SYSTEM IN NORTHWEST FLOW ALOFT WILL MOVE ACROSS
THE NORTHERN PLAINS. MOST OF THE FORECAST AREA WILL REMAIN ON THE COOL
SIDE OF THE SYSTEM AS THE SURFACE LOW TRACKS FROM CENTRAL SASKATCHEWAN
TO NORTHEAST SD. AFTERNOON HIGHS WILL MAINLY BE IN THE SINGLE DIGITS
TO LOW TEENS ABOVE ZERO...BUT AREAS WEST OF A LINE FROM DEVILS LAKE
TO VALLEY CITY TO LISBON MAY CLIMB INTO THE LOW 20S. CANADIAN RADARS
SHOW LIGHT SNOW SOUTH AND EAST OF THE SURFACE LOW AND THIS BAND IS
EXPECTED TO MOVE SOUTHEASTWARD THROUGH THE DAY...MAINLY IMPACTING
EASTERN ND INTO WEST CENTRAL MN. SLOWED THE TIMING OF THE HIGHEST
POPS AS LATEST RAP OUTPUT KEEPS MAJORITY OF PRECIPITATION OUT OF
THE FORECAST AREA UNTIL AFTER 15 UTC. TOTAL ACCUMULATIONS THROUGH
TONIGHT WILL GENERALLY BE AN INCH OR LESS.
REMAINING SNOW SHOWERS EXPECTED TO MOVE EAST OF THE FORECAST AREA
BY MIDNIGHT WITH DECREASING CLOUD COVER FROM WEST TO EAST. SUNDAY
MORNING LOWS EXPECTED IN THE 0 TO 10 BELOW RANGE...BUT WILL BE
HIGHLY DEPENDENT ON CLOUD COVER.
ANOTHER WEAK CLIPPER DROPS SOUTH ON SUNDAY...BRINGING A NARROW
BAND OF LIGHT SNOW FROM CENTRAL ND INTO SOUTHWEST MN. STRONG
SURFACE HIGH WILL MOVE INTO THE NORTHERN VALLEY BY 06 UTC MONDAY
AND THIS WILL LIMIT NORTHWARD EXTENT OF PRECIPITATION. MODEL
TRENDS PLACE SNOW FARTHER SOUTH...SO ADJUSTED HIGHEST POPS SOUTH
OF A LINE FROM DEVILS LAKE TO HILLSBORO TO PARK RAPIDS.
ACCUMULATIONS EXPECTED TO BE EVEN LESS THAN TODAY...GENERALLY A
HALF INCH OF LESS. SKIES WILL BE MOSTLY CLOUDY AND TEMPERATURES
WILL BE NEAR OR SLIGHTLY COOLER THAN TODAY IN THE WAKE OF TODAY/S
SYSTEM.
THE PARADE OF CLIPPERS CONTINUE INTO EARLY NEXT WEEK WITH A THIRD
WAVE ON MONDAY. THE TRACK OF THE SURFACE LOW IS A BIT FARTHER
NORTH...SO EXPECT GREATER SPATIAL COVERAGE OF ACCUMULATING
SNOWFALL. STRONG MID-LEVEL WARM AIR ADVECTION WILL COMBINE UPPER
JET DYNAMICS TO PRODUCE A COUPLE INCHES OF SNOW ACROSS THE
NORTHERN VALLEY INTO NORTHWEST MN. WITH TRACK OF THE LOW AND
ALIGNMENT OF THE BAROCLINIC AXIS...TEMPERATURES WILL BE A BIT
WARMER WITH AFTERNOON HIGHS MAINLY IN THE TEENS ABOVE ZERO.
MORNING LOWS WILL CONTINUE TO BE DEPENDENT ON CLOUD COVER...BUT
NOT EXPECTING MUCH DAY TO DAY CHANGE WITH THE COOLEST READINGS
ACROSS THE LAKE OF THE WOODS REGION.
LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
NW FLOW ALOFT WILL SLOWLY TRANSITION TO A MORE ZONAL/SW FLOW ALOFT
BY NEXT WEEKEND. THIS WILL MEAN GRADUALLY WARMING TEMPS ABOVE NORMAL
WITH MINIMAL CHANCES FOR PRECIP THROUGH SAT. THERE IS THE POTENTIAL
FOR SOME LINGERING LIGHT SNOW EARLY TUE IN THE EAST...AND IN THE
NORTH ON WED WITH SOME WAA. OTHERWISE...EXPECT A DRY EXTENDED WITH
A WARMING TREND. THERE ARE SOME HINTS AT A POTENTIAL STORM BY LATE
SAT INTO SUNDAY...WITH THE MAIN POTENTIAL IMPACTS AT THIS TIME
POSSIBLE IN THE SOUTHERN FORECAST AREA.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
JR
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1235 PM EST SAT FEB 2 2013
.SYNOPSIS...
A CLIPPER SYSTEM WILL TRACK EAST ACROSS THE GREAT LAKES AND OHIO
VALLEY THROUGH TONIGHT. A WEAK UPPER LEVEL WEATHER DISTURBANCE
WILL AFFECT THE REGION ON SUNDAY. HIGH PRESSURE WILL BUILD BRIEFLY
INTO THE OHIO VALLEY SUNDAY NIGHT. THE HIGH WILL MOVE EAST ON
MONDAY AS ANOTHER CLIPPER SYSTEM QUICKLY MOVES TOWARD THE OHIO
VALLEY FROM THE NORTHWEST.
&&
.NEAR TERM /THROUGH TONIGHT/...
SNOW HAS OVERSPREAD THE FORECAST AREA. NAM AND RAP MODELS HAVE
GOOD REPRESENTATIONS OF THE AREA OF SNOW. ACCUMULATIONS HAVE BEEN
UP TO AN INCH IN SOUTHWEST COUNTIES.
THE BEST ISENTROPIC LIFT WILL OCCUR AHEAD OF THE WEAK SFC LOW AND
FRONT. THUS...MUCH OF THE SNOW ACCUMULATION WILL OCCUR DURING THE
DAYLIGHT HOURS. THE SNOW WILL TAPER OFF FROM WEST TO EAST THIS
EVENING AS THE CLIPPER MOVES OFF TO THE EAST. USING A BLEND OF
MODEL QPF AND SNOW TO LIQUID RATIOS BASED ON TEMPERATURE...IT
STILL LOOKS LIKE A GOOD 2 TO 3 INCH SNOW EVENT AREA WIDE WITH
ISOLATED AMOUNTS NEAR 4 INCHES. A WINTER WEATHER ADVISORY WILL
REMAIN IN EFFECT THROUGH TONIGHT.
WITH LOW LEVEL WAA...HIGHS TODAY SHOULD RANGE FROM THE MID 20S
NORTH TO THE LOWER 30S SOUTH. IN CAA BEHIND THE DEPARTING
CLIPPER...OVERNIGHT LOWS SHOULD RANGE FROM THE MID TEENS
NORTHWEST TO THE LOWER 20S SOUTHEAST.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
OUR REGION WILL REMAIN UNDER A NORTHWEST FLOW PATTERN ALOFT
THROUGH THE SHORT TERM PERIOD. THIS PATTERN WILL ALLOW SEVERAL
WEATHER SYSTEMS TO AFFECT THE AREA.
ON SUNDAY...A SHEARED OUT WEAK UPR LVL WX DISTURBANCE WILL PASS
ACRS THE REGION. THIS FEATURE WILL KEEP SKIES MAINLY CLOUDY ALONG
WITH A CHANCE OF SNOW SHOWERS. THE WEAK DISTURBANCE WILL EXIT THE
AREA BY SUNDAY EVENING. DESPITE SURFACE HIGH PRESSURE BRIEFLY
BUILDING INTO THE OHIO VALLEY...CLOUDS WILL CONTINUE TO SPILL
SOUTHEAST FROM THE NEXT CLIPPER SYSTEM WHICH WILL LIMIT ANY
OPPORTUNITY TO CLEAR OUT.
FOR MONDAY INTO MONDAY NIGHT...MODELS ALL INDICATE THAT A CLIPPER
SYSTEM WILL TRACK SOUTHEAST THROUGH THE OHIO VALLEY. AM CONFIDENT
ENOUGH AT THIS POINT TO RAISE POPS TO LIKELY FOR MONDAY AFTERNOON
INTO MONDAY NIGHT. THERE CONTINUES TO BE STRENGTH ISSUES WITH THE
LOW AND ITS ASSOCIATED WAA/LOW LEVEL JET WHICH WILL ULTIMATELY
DICTATE PCPN TYPE AND SNOW ACCUMULATIONS. AT THIS POINT IT LOOKS
LIKE MUCH OF THE AREA NORTH OF THE OHIO RIVER WILL SEE SNOW WHILE
RAIN MAY MIX WITH SNOW ALONG AND SOUTH OF THE RIVER MONDAY
AFTERNOON INTO MONDAY EVENING UNTIL CAA CHANGES THE PCPN TO ALL
SNOW BEFORE TAPERING OFF LATE. AGAIN...WE SHOULD SEE SOME
ACCUMULATIONS BUT AMOUNTS ARE STILL UNCERTAIN AT THIS POINT DUE TO
REASONS JUST MENTIONED. WILL SPELL THIS OUT IN THE HWO PRODUCT.
LITTLE RESPITE IS EXPECTED TUESDAY INTO TUESDAY NIGHT AS ANOTHER
CLIPPER SYSTEM WILL BE ON THE HEELS OF THE MONDAY/MONDAY NIGHT
SYSTEM. THERE CONTINUES TO BE PLACEMENT ISSUES WITH THIS FEATURE
IN HOW FAR SOUTH IT WILL DIG. HAVE KEPT POPS IN THE CHANCE
CATEGORY UNTIL MODELS RESOLVE THIS DILEMMA. PCPN WILL BE IN THE
FORM OF SNOW NORTH WITH RAIN/SNOW POSSIBLE SOUTH.
AS FOR TEMPERATURES...THEY WILL BE HARD TO PINPOINT GIVEN SNOW
COVER AND SURFACE LOW PLACEMENT WITH THE UPCOMING CLIPPER SYSTEMS
WHICH WILL RESULT IN SFC WAA AHEAD OF THE LOW CENTER. MAINLY USED
A BLEND OF THE GFS/ECMWF SURFACE TEMPERATURES ALONG WITH
CLIMATOLOGICAL THICKNESS SCHEMES.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL BE IN PLACE ACROSS THE AREA FOR WEDNESDAY AND
WILL MOVE EAST OF THE FA ON THURSDAY. WITH SOUTHERLY FLOW ON
THURSDAY TEMPERATURES WILL RANGE FROM THE MIDDLE 30S TO THE MIDDLE
40S ACROSS THE REGION. PRECIPITATION WILL BEGIN TO MOVE INTO THE
FA THURSDAY EVENING AND BECOME MORE WIDESPREAD ACROSS THE AREA
THURSDAY NIGHT AS A COLD FRONT APPROACHES AND MOVES THROUGH THE
REGION. PRECIPITATION WILL TAPER OFF ACROSS THE FA DURING THE
MORNING HOURS ON FRIDAY AND HIGH PRESSURE WILL WORK BACK INTO THE
REGION FRIDAY AFTERNOON.
&&
.AVIATION /18Z SATURDAY THROUGH WEDNESDAY/...
SNOW WILL CONTINUE TO IMPACT AVIATION. VISIBILITIES AS LOW AS IFR
WILL PERSIST THIS AFTERNOON UNTIL WEAK LOW PRESSURE AND BANDS OF
SNOW MOVE EAST. SINCE MODELS HAVE LOW LEVEL MOISTURE REMAINING IN
PLACE...MVFR CEILINGS SHOULD LINGER THROUGH THE END OF THE TAF
PERIOD. WINDS WILL GUST CLOSE TO 20 KNOTS OUT OF THE SOUTH TO
SOUTHWEST THIS AFTERNOON. LOOK FOR A SHIFT IN DIRECTION TO WEST
TONIGHT BEHIND THE WEAK LOW. MORE SNOW SHOWERS ARE EXPECTED ON
SUNDAY DUE TO A WEAK DISTURBANCE IN THE JET STREAM.
OUTLOOK...MVFR TO IFR CONDITIONS ARE EXPECTED AGAIN ON MONDAY
AND MONDAY NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WINTER WEATHER ADVISORY UNTIL 7 AM EST SUNDAY FOR OHZ026-034-
035-042>046-051>056-060>065-070>074-077>082-088.
KY...WINTER WEATHER ADVISORY UNTIL 7 AM EST SUNDAY FOR KYZ089>100.
IN...WINTER WEATHER ADVISORY UNTIL 7 AM EST SUNDAY FOR INZ050-058-
059-066-073>075-080.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...CONIGLIO/HICKMAN
SHORT TERM...HICKMAN
LONG TERM...NOVAK
AVIATION...CONIGLIO
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
336 PM CST SAT FEB 2 2013
.DISCUSSION...
VERY WEAK FRONTAL BOUNDARY SHOULD MAKE ITS WAY TO THE I-10
CORRIDOR AROUND MIDNIGHT THEN OFFSHORE BEFORE SUNRISE. MAY SEE
SOME AREAS OF FOG CLOSER TO THE COAST BEFORE FROPA. OFFSHORE
WINDS WILL BE SHORT LIVED AS SE FLOW WILL RESUME BY EVENING WHEN
SFC HIGH PUSHES OFF TO THE EAST.
THESE ONSHORE WINDS WILL TRANSPORT SOME 1.3"-1.5" PW`S BACK INTO
THE AREA ON MONDAY COINCIDING WITH SOME WEAK IMPULSES MOVING
OVERHEAD. ANTICIPATE SOME SCT SHRA TO DEVELOP ACROSS THE REGION
WITH THE HIGHEST CHANCES PROBABLY E OF I-45.
APPEARS ANOTHER REALLY WEAK FRONT WILL APPROACH THE COAST ON TUES. LOOKS
LIKE IT`LL STALL JUST INLAND. GFS/ECMWF IN FAIR AGREEMENT SHOWING
UPPER TROF (CURRENTLY SEEN ON W/V IMAGERY OFF THE NRN CALIFORNIA
COAST) DROPPING SOUTH THEN EAST ACROSS S TX TUES NIGHT & WED.
THIS SHOULD PROVIDE OUR NEXT SHOT OF RAINFALL...ESPECIALLY THE SRN
HALF OF SE TX AND OFFSHORE. NUDGED POPS UPWARD DURING THIS TIME
PERIOD - AND WILL PROBABLY NEED TO CONTINUE DOING SO IF FUTURE
MODEL RUNS ARE CONSISTENT.
THE NEXT WRN TROF MAKES ITS WAY EWD NEXT WEEKEND. STILL SOME
TIMING/PATTERN DIFFERENCES BUT MEDIUM RANGE GUESSES BRING THE NEXT
COLD FRONT AND ASSOCIATED PRECIP INTO THE REGION NEXT SUNDAY...BUT
MAY SEE SOME SCT ACTIVITY IN ADVANCE ON SAT. 47
&&
.MARINE...
THE WEAK COLD FRONT SHOULD WORK ITS WAY OFF THE COAST BY AROUND 6 AM
SUNDAY. DO NOT THINK SEA FOG WILL FORM AS THE SURFACE DEWPOINTS
SHOULD STAY BELOW THE WATER TEMPERATURES. OTHERWISE...ONSHORE WINDS
WILL QUICKLY RETURN AHEAD OF THE NEXT FRONT TO MOVE OFF THE COAST
EARLY TUESDAY. MODERATE ONSHORE FLOW MAY DEVELOP BY AROUND MID WEEK
AS THE MODELS ARE SHOWING AN INCREASED PRESSURE GRADIENT. 40
&&
.147 PM AVIATION...
VFR CONDITIONS WILL PERSIST THROUGH THIS EVENING. A WEAK FRONT IS
FORECAST TO PUSH THROUGH TO THE COAST BY AROUND SUNRISE SUNDAY.
THERE IS A CHANCE THAT FOG WILL DEVELOP AHEAD OF THE FRONT...
ESPECIALLY FROM KCXO TO THE COAST. THE LATEST MODELS ARE A BIT
FASTER WITH THE FRONT PUSHING OUT THE FOG THAN THE 18Z FORECAST
INDICATES. WILL COMPARE THE LATEST RAP MODEL FORECASTS AND MAKE
ADJUSTMENTS ON THE 21Z UPDATE IF NEEDED. 40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 44 70 50 72 53 / 0 0 10 30 20
HOUSTON (IAH) 49 72 52 74 56 / 0 0 0 30 30
GALVESTON (GLS) 56 68 60 70 60 / 0 0 0 20 40
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
147 PM CST SAT FEB 2 2013
.DISCUSSION...
SEE THE 18Z/21Z AVIATION DISCUSSION BELOW.
40
&&
.AVIATION...
VFR CONDITIONS WILL PERSIST THROUGH THIS EVENING. A WEAK FRONT IS
FORECAST TO PUSH THROUGH TO THE COAST BY AROUND SUNRISE SUNDAY.
THERE IS A CHANCE THAT FOG WILL DEVELOP AHEAD OF THE FRONT...
ESPECIALLY FROM KCXO TO THE COAST. THE LATEST MODELS ARE A BIT
FASTER WITH THE FRONT PUSHING OUT THE FOG THAN THE 18Z FORECAST
INDICATES. WILL COMPARE THE LATEST RAP MODEL FORECASTS AND MAKE
ADJUSTMENTS ON THE 21Z UPDATE IF NEEDED.
40
&&
.PREV DISCUSSION... /ISSUED 952 AM CST SAT FEB 2 2013/
DISCUSSION...
SHOULD SEE A NICE WARM UP THIS AFTN WITH HIGHS TOPPING OUT IN THE
70S. CURRENT FCST IS IN GOOD SHAPE. JUST SOME INSIGNIFICANT TWEAKS
TO THE GRIDS BASED ON LATEST TRENDS FOR THE MORNING UPDATE. 47
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 74 43 69 50 72 / 0 10 0 20 30
HOUSTON (IAH) 75 48 71 51 74 / 0 10 0 10 30
GALVESTON (GLS) 71 55 68 57 68 / 0 10 0 10 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...47
AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
230 PM CST SAT FEB 2 2013
.SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT
230 PM CST SAT FEB 2 2013
THE TRAIN OF NORTHWEST FLOW SHORTWAVES CONTINUES.
TONIGHT...AN UPPER LEVEL SHORTWAVE CURRENTLY MIGRATING ACROSS THE
NORTHERN PLAINS WILL SLIDE ACROSS THE REGION. SOME WEAK 2-D
FRONTOGENETIC RESPONSE AT 900 MB WITH THE FEATURE...ALONG WITH WEAK
QG CONVERGENCE THROUGH THE 850-300 MB LAYER. SOME ISENTROPIC UPGLIDE
ON THE 280-290 K SFCS THIS EVENING...MOST OF WHICH EXITS EAST AFTER
06Z. GOOD DENDRITIC ZONE GROWTH //DGZ// REGION THOUGH...FROM 700 MB
TO THE SFC FOR MUCH OF TONIGHT...WHEN THE SNOW WILL BE FALLING.
RATIOS OF 30:1 ARE REASONABLE GIVEN THIS SCENARIO. THIS SHORTWAVE
DOESN/T LOOK TO BE AS PERKY AS THE ONE LAST NIGHT...AND WILL HAVE
EVEN LESS QPF. SO...EXPECT LESS SNOWFALL AMOUNTS. SOME CONCERN THAT
IT MIGHT MISS A BULK OF THE FORECAST AREA...WITH LATEST HRRR AND ARW
MESO MODELS SUGGESTING THAT MOST OF THE ACCUMULATING SNOWS WILL MOVE
INTO CENTRAL IA. THE NAM12/GFS40 SHOW SOMETHING SIMILAR...BUT STILL
PAINT SOME LIGHT SNOW INTO NORTHERN WI. WILL TREND THE HIGHER POPS
TO THE SOUTH.
SHORTWAVE NUMBER 4 SPINS ACROSS IA SUNDAY NIGHT...EXITING OVER THE
OH RIVER VALLEY ON MONDAY. FRONTOGENETIC RESPONSE IS MUCH STRONGER
WITH THIS FEATURE...AS IS THE QG CONVERGENCE AND ISENTROPIC UPGLIDE.
THE DGZ ISN/T AS DEEP AS EXPECTED FOR TONIGHT...AND WITH PREVIOUS
SHORTWAVES. THIS WILL HELP KEEP RATIOS CLOSER TO 15/20:1.
NAM/GFS/ECMWF ALL COMPARABLE WITH PRODUCING A RELATIVELY NARROW BAND
OF QPF...FOCUSED ON THE FRONTOGENETIC REGION...AND CENTER IT ROUGHLY
AROUND A ROCHESTER TO RICHLAND CENTER LINE. SEE THE POTENTIAL FOR
SOME ADVISORY AMOUNTS IN THE BAND...3 TO 4 INCHES POSSIBLE. NOT
ENOUGH CONFIDENCE TO ISSUE AT THIS TIME...BUT SCENARIO WILL CONTINUE
TO EVALUATED.
COME TUE...SURPRISE...SHORTWAVE NUMBER 5 DROPS FROM CANADA TO ACROSS
NORTHERN PARTS OF MN/WI. GFS AND NAM BOTH AGREE ON A SLIGHTLY MORE
NORTHERLY TRACK TO THIS WEATHER FEATURE...BRINGING THE BETTER SNOW
CHANCES TO NORTHERN PARTS OF THE FORECAST AREA. ANOTHER
INCH...PERHAPS TWO...LOOKS LIKELY.
.LONG TERM...WEDNESDAY THROUGH SATURDAY
230 PM CST SAT FEB 2 2013
VERY ACTIVE NORTHWEST FLOW CONTINUES THROUGH THE END OF THE WORK
WEEK. HOWEVER...WE MIGHT SEE THE CABOOSE WED NIGHT/THU
MORNING...WITH THE EC AND GFS SPINNING A PIECE OF UPPER LEVEL ENERGY
ACROSS THE REGION WED NIGHT...REINFORCED BY A STRONGER SHORTWAVE THU
MORNING. SOME QUESTION ON PTYPES WITH THIS EVENT AS WARMER AIR WILL
BE RETURNING...AND A POSSIBLE LOSS OF ICE IN THE CLOUD AS THE SYSTEM
STARTS TO EXIT EAST. WON/T GET OVERLY DETAILED WITH GRIDS AT THE
MOMENT...BUT THE POTENTIAL FOR MIXED WINTER PCPN WILL HAVE TO BE
MONITORED.
THE GFS AND EC FAVOR BRINGING A LOW PRESSURE SYSTEM OUT OF THE SOUTH
FOR THE WEEKEND...DRIVING IT ACROSS THE REGION SAT/SUN. DIFFERENCING
IN STRENGTH AND POSITION...AND SOME VARIANCE IN TIMING. BOTH WOULD
LAY DOWN A DEFORMATION BAND OF SNOW...BUT ALSO LIKELY HAVE SOME
RAIN/WINTER MIX ON ITS SOUTHEAST SIDE. THIS SYSTEM ALSO LOOKS TO
PACK MUCH MORE OF A PUNCH THAN THE PARADE OF SHORTWAVES MOVING DOWN
FROM THE NORTHWEST.
&&
.AVIATION...
1146 AM CST SAT FEB 2 2013
THIS AFTERNOON...MID CLOUDS /8 TO 10K/ WILL BE ON THE INCREASE AND
THE LIGHT SURFACE WINDS WILL GRADUALLY SHIFT FROM THE NORTHWEST TO
THE SOUTH AS YET ANOTHER SHORTWAVE MOVES THROUGH THE REGION.
TONIGHT...THE SHORTWAVE TROUGH WILL MOVE THROUGH THE REGION. AT THIS
TIME IS LOOKS LIKE THE BEST LIFT WILL OCCUR BETWEEN 03.02Z AND
03.07Z AT KRST AND BETWEEN 03.04Z AND 03.08Z AT KLSE. IN
ADDITION...THIS LIFT IS CO-LOCATED WITH A 8K FOOT DENDRITIC GROWTH
ZONE. THIS WILL RESULT IN ANOTHER ROUND OF SNOW FOR THE AREA.
VISIBILITIES WILL QUICKLY DROP TO 1 1/2 MILES DURING THIS TIME
PERIOD AND THE CEILINGS WILL BECOME MVFR. SNOW AMOUNTS WILL BE
AROUND AN INCH.
SUNDAY...SUBSIDENCE WILL CAUSE THE SKIES TO GRADUALLY CLEAR
BETWEEN 03.12Z AND 03.16Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
230 PM CST SAT FEB 2 2013
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION.....BOYNE
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1153 AM CST SAT FEB 2 2013
.UPDATE...VIS SAT SHOWS SKIES CLEARING ACROSS NORTHERN PORTIONS OF
THE FORECAST AREA...WITH THE BACK EDGE OF THE LOW LEVEL CLOUDS
WORKING ITS WAY SOUTH. UPDATED SKY GRIDS TO REFLECT LATEST
TRENDS. BOTH RAP AND NAM BUFKIT MODEL SOUNDINGS REFLECT SUCH A
TREND...AND HAVE THE LOW LEVELS OF THE MODEL SOUNDINGS DRYING OUT.
FURTHER...THE MODEL RH FIELDS...ESPECIALLY AT 850 HPA...SHOW A
DECREASING RH TREND.
FOR LATER IN THE DAY...NAM12 AND RAP BOTH SHOW AN INCREASE IN
MID- AND UPPER-LEVEL RH...THAT COINCIDES WITH CLOUDS SEEN ACROSS
EASTERN MN INTO SOUTHWESTERN WISCONSIN. THESE CLOUDS ARE EXPECTED
TO CONTINUE TO WORK THEIR WAY INTO SOUTH CENTRAL AND SOUTHEAST WI
THIS AFTERNOON.
TEMPERATURES WERE UPDATED TO REFLECT LATEST TRENDS. GIVEN THE
BREAK IN THE CLOUDS THAT WASNT EXACTLY ANTICIPATED IN THE
FCST...NOW CONCERNED WITH THE IMPACT LESS SKY COVER WILL HAVE ON
HIGH TEMPS. HOWEVER...THERE IS LIGHT COLD AIR ADVECTION ONGOING ON
THE LOW LEVELS. TEMPERATURE FCST IS TRENDING OK SO FAR...SO WILL
WAIT A BIT AND WILL EVALUATE MORE OF SHORT TERM GUIDANCE AND
ADJUST IF NEEDED.
ET
&&
.AVIATION/18Z TAFS/...VFR CONDITIONS EXPECTED ACROSS TAF SITES
THIS AFTERNOON AND EVENING. WINDS WILL BACK FROM NORTH THIS
AFTERNOON TO SOUTHWEST BY 06Z SUNDAY...REMAINING LIGHT. LOW CLOUDS
WILL MOVE SOUTH OF THE AREA EARLY THIS AFTERNOON...WITH MID TO
HIGH CLOUDS GRADUALLY FILLING INTO THE AREA THROUGH THE AFTERNOON
AND EVENING.
MVFR CEILINGS WITH VERY LIGHT SNOW IS EXPECTED BETWEEN 06Z AND 12Z
SUNDAY AT MADISON...AND 09Z AND 15Z SUNDAY AT THE EASTERN TAF
SITES. THE VERY LIGHT SNOW MAY BE ON AND OFF...AND ANY
ACCUMULATIONS WOULD BE 0.1 TO 0.2 INCHES AT BEST. FLUFFY AND
POWDERY SNOW IS EXPECTED...BUT STILL WOULD BE AN IMPACT ON
RUNWAYS.
WINDS VEER NORTHWEST BETWEEN 12Z AND 15Z SUNDAY AND BECOME GUSTY
THROUGH THE DAY. GUSTS TO 23 KNOTS ARE EXPECTED.
WOOD
&&
.PREV DISCUSSION... /ISSUED 344 AM CST SAT FEB 2 2013/
SHORT TERM...
TODAY AND TONIGHT...FORECAST CONFIDENCE - MEDIUM.
ENHANCED FORCING FROM WARM AIR ADVECTION SLIDING OFF TO THE
SOUTHEAST EARLY THIS MORNING RESULTING IN DIMINISHING ACCUMULATING
SNOW. HOWEVER...AREAS OF VERY LIGHT SNOW LAGGING BEHIND ASSOCIATED
WITH WEAK 85H TROUGH WHICH PASSES THRU SRN WI MAY RESULT IN AN
ADDITIONAL DUSTING BTWN 12Z AND 15Z. CLOUDS SHOULD THIN LATER TODAY
ALLOWING SOME SUNSHINE TO RETURN FOR A TIME. HOWEVER CLEARING WL BE
SHORT-LIVED AS ANOTHER WEAKER PUSH OF WARM AIR ADVECTION WL SWEEP
THROUGH WI TNGT.
WATER VAPOR IMAGERY CLEARLY SHOWS UPSTREAM SHORT WAVE TROUGH OVER
SRN SASKATCHEWAN MOVING SOUTHEAST. APPEARS SHORT TERM GUIDANCE
HAVING DIFFICULTY WITH THIS WAVE BUT IF IT MAINTAINS ITS CURRENT
SOUTHEAST COURSE...WOULD AFFECT PORTIONS OF SOUTHEAST WI OVERNIGHT.
POSSIBLE HINTS FROM Q-VECTOR CONVERGENCE WHERE AXIS OF -5 TO -10
UNITS MOVES ACROSS SRN WI FROM LATE EVE THRU THE OVERNIGHT. LITTLE
FRONTOGENETICAL FORCING...BUT SOME ISENTROPIC OMEGA SHOWING UP ON
280 THETA SFC OVERNIGHT. CONDENSATION PRESSURE DEFICITS DECREASE TO
LESS THAN 10 MB FOR A 3-6 HOUR PD. FOR NOW BUMPED UP TO LIKELY
WORDING ACROSS MORE OF THE NORTH AND WEST...WITH HIGHER CHC
ELSEWHERE. DEEP DENTRITIC GROWTH ZONE WOULD BE TAPPED BY WEAK
FORCING SO SNOW LIQUID RATIOS COULD AGAIN BE HIGHER THAN EXPECTED 25
TO 1. FOR NOW WL KEEP LIGHT ACCUMULATIONS LESS THAN AN INCH IN THE
NORTH AND WEST.
SUNDAY...FORECAST CONFIDENCE HIGH.
STRONG SUBSIDENCE BEHIND THE EXITING 500MB SHORTWAVE EXPECTED TO
BRING SOME SUNSHINE TO SOUTHERN WI DURING THE DAY ON SUNDAY. ONLY
EXPECTING LOWER TO MID TEENS FOR HIGH TEMPS...ALONG WITH COLD WIND
CHILLS WITH WEAK COLD AIR ADVECTION ON BRISK NORTHWEST WINDS.
SUNDAY NIGHT THROUGH MONDAY...FORECAST CONFIDENCE MEDIUM TO HIGH.
THE NEXT SHORTWAVE WILL BRING ANOTHER ROUND OF SNOW TO SOUTHERN WI
SUNDAY NIGHT. INCREASED POPS TO THE DEFINITE CATEGORY AS IMPRESSIVE
700 TO 850MB FRONTOGENESIS AND 700MB OMEGA MOVE ACROSS SOUTHERN
WISCONSIN. THIS WILL PROBABLY BE AN EVENT WHERE A NARROW LINE GETS A
SWATH OF 3 INCHES OF SNOW AND AREAS AROUND IT GET AN INCH. MANY
MODELS FOCUS THE HIGHEST QPF SWATH ACROSS FAR SOUTHERN WI AND
NORTHERN IL. THE CANADIAN HAS THIS SHIFTED SLIGHTLY NORTHWARD. USED
A CONSENSUS FOR SNOW RATIOS IN THE 17 TO 19:1 RANGE. THE 06Z NAM
CAME IN WITH A LATER ARRIVAL/END TIME OF THIS EVENT BY ALMOST 6
HOURS. FAVORED ECMWF TIMING FOR NOW.
SNOW WILL TAPER OFF MONDAY MORNING...ALTHOUGH FLURRIES MAY LINGER
INTO THE AFTERNOON WITH CYCLONIC FLOW ALOFT STICKING AROUND. WEAK
COLD ADVECTION WITH THE SURFACE HIGH MOVING OVERHEAD WILL KEEP TEMPS
COOL ONCE AGAIN...SO HIGHS IN THE UPPER TEENS TO AROUND 20 EXPECTED.
LONG TERM...
TUESDAY...FORECAST CONFIDENCE MEDIUM TO HIGH.
A STRONGER SHORTWAVE TROUGH/VORT MAX ON THE RIGHT ENTRANCE REGION OF
A 110 KNOT UPPER JET WILL ROLL THROUGH THE UPPER MIDWEST ON TUESDAY.
THE ASSOCIATED SURFACE LOW PRESSURE SYSTEM WILL TRACK ACROSS MN AND
WI AS IT WEAKENS AS THE 500MB VORT MAX SHEARS OUT. IT IS BECOMING
MORE LIKELY THAT LIGHT SNOW WILL SPREAD ACROSS SOUTHERN AND CENTRAL
WI EARLY TUE MORNING THROUGH TUE AFTERNOON. SNOW AMOUNTS SHOULD BE
ABOUT 1 TO 2 INCHES.
TUESDAY NIGHT THROUGH FRIDAY...FORECAST CONFIDENCE MEDIUM.
THE FLOW ALOFT WILL TRANSITION TO MORE ZONAL WED AND THU. QUIET
WEATHER EXPECTED ON WEDNESDAY. THEN TEMPS PROGGED TO WARM INTO THE
LOWER 30S ON THU JUST AHEAD OF THE NEXT SHORTWAVE BY THU AFTERNOON.
THE 850MB 0 DEGREE LINE IS FORECAST TO REACH THE WI/IL BORDER...BUT
THE TEMP PROFILE IN FORECAST SOUNDINGS REMAINS BELOW ZERO EXCEPT AT
THE SURFACE. THIS WOULD IMPLY A CHANCE FOR SOME SNOW TO CHANGE OVER
TO RAIN ACROSS SOUTHERN WI LATER THU AFTERNOON IF THE SURFACE WARMS
JUST ENOUGH. KEPT A RAIN/SNOW MIX THERE AND SNOW IN THE NORTHERN
FORECAST AREA.
HIGH PRESSURE AND QUIET WEATHER WITH HIGHS IN THE LOWER 30S WILL BE
IN PLACE FOR FRIDAY. MODELS ARE ADVERTISING A WET SYSTEM APPROACHING
WI OVER THE WEEKEND.
AVIATION/12Z TAFS/...VARYING VSBYS THIS MRNG BTWN MVFR AND VFR AND
-SN DIMINISHES ACROSS SRN WI. MOSTLY VFR CONDITIONS EXPCD THIS AFTN
BEFORE ANOTHER BATCH OF -SN AFFECTS SRN WI TNGT. PERIOD OF -SN WILL
BE BRIEFER THAN THIS MRNG WITH LESS ACCUMULATION.
MARINE...TIGHTENING PRESSURE GRADIENT BEHIND PASSING WEAK LOW
PRESSURE TROUGH MAY RESULT IN WIND GUSTS TO SMALL CRAFT ADVY LEVELS
ON SUNDAY...IN ICE FREE AREAS. THE GUSTY NORTHWEST WINDS WOULD
LINGER INTO SUNDAY EVENING BEFORE DIMINISHING.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...ET/WOOD
TODAY/TONIGHT AND AVIATION/MARINE...MBK
SUNDAY THROUGH FRIDAY...MRC