Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 02/23/12
AREA FORECAST DISCUSSION
NWS ALBANY NY
1258 PM EST TUE FEB 21 2012
.SYNOPSIS...
HIGH PRESSURE WILL SHIFT EASTWARD AND OFFSHORE TODAY WITH CLOUDS ON
THE INCREASE. A WARM FRONT WILL MOVE ACROSS THE REGION TONIGHT
ACCOMPANIED BY RAIN AND SNOW SHOWERS. THE WEATHER WILL REMAIN
UNSETTLED FOR THE REST OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
CI/CS CLOUD CANOPY CONTINUES TO THICKEN AND LOWER AS UPPER LOW
NEAR DETROIT LIFTS NORTHEAST. REGIONAL RADARS SHOW SHOWER ACTIVITY
HAS MOVED INTO EXTREME WESTERN NY AND WESTERN PA. UPSTREAM METARS
SHOW A MIXTURE OF RAIN/SNOW AS THIS WILL BECOME OUR ISSUE LATER
THIS EVENING. AS FOR ARRIVAL TIMING...PER THE HRRR AND
EXTRAPOLATING RADAR TRENDS...SEEMS OUR WESTERN AREAS COULD SEE
PRECIP AS EARLY AS 4 PM EST AND INTO THE HUDSON RIVER VALLEY
AROUND 6 PM. SO HAVE MADE SLIGHT ADJUSTMENTS TO THE POPS/WX GRIDS.
OTHERWISE...TEMPERATURES LOOK ON TRACK AND LITTLE CHANGES NEEDED
AT THIS TIME.
THIS PIECE OF ENERGY WILL LOSE ITS IDENTITY TONIGHT. HOWEVER MORE
ENERGY MOVING THROUGH THE LONGWAVE TROUGH WILL BE ON ITS HEALS.
WILL HAVE WEAK FRONTAL BOUNDARY...OCCLUDING WARM FRONT MOVE ACROSS
THE REGION TONIGHT. THE BEST CHANCES FOR SHOWERS WILL BE ACROSS
THE SOUTHERN ADIRONDACKS WHERE THE BETTER UPPER SUPPORT WILL BE.
IT WILL BE COLD ENOUGH FOR MAINLY SNOW ACROSS THE SOUTHERN
ADIRONDACKS WITH UP TO A COUPLE INCHES OF SNOW EXPECTED.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
MODEL GUIDANCE HAS NOT BEEN CONSISTENT HANDLING THE NEXT SIGNIFICANT
PIECE OF ENERGY MOVING THROUGH THE LONGWAVE PATTERN AND HOW AND
WHERE THE LOW PRESSURE SYSTEM ASSOCIATED WITH IT DEVELOPS. AS FOR
WEDNESDAY AND WEDNESDAY NIGHT...A SURFACE LOW WILL MOVE GRADUALLY
EASTWARD ACROSS ONTARIO AND QUEBEC WHILE THE UPPER TROUGH FLATTENS
OVER OUR REGION. PIECES OF ENERGY WILL MOVE THROUGH THIS FAST FLOW
KEEPING THE THREAT FOR PRECIPITATION IN THE FORECAST. MORE
ORGANIZED/WIDESPREAD PRECIPITATION WILL BEGIN TO MOVE INTO THE
REGION THURSDAY AS A LOW PRESSURE SYSTEM APPROACHES.
EXPECTING EVEN MILDER TEMPERATURES WEDNESDAY WITH SOUTHWESTERLY FLOW
ACROSS THE AREA...SHOULD REACH 50 DEGREES IN THE CAPITAL DISTRICT.
NOT QUITE AS MILD THURSDAY BUT STILL ABOVE NORMAL BY AROUND 10
DEGREES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE MEDIUM RANGE GUIDANCE CONTINUE TO FORECAST AN ACTIVE WEATHER
PATTERN AT THE END OF THE WEEK...AND THE BEGINNING OF THE WEEKEND.
THERE STILL IS QUITE A BIT OF UNCERTAINTY ON THE
TIMING...EVOLUTION...AND IMPACT OF A SYSTEM FRIDAY INTO
SATURDAY...AND WE ARE LEANING MORE TOWARDS AN HPC/GFS/GLOBAL
ENSEMBLE MEAN SCENARIO INTO THE FIRST HALF OF THE WEEKEND...AND THEN
FOLLOWED CLOSER TO HPC THEREAFTER.
THURSDAY NIGHT...A SFC CYCLONE APPROACHES THE FORECAST AREA FROM THE
GREAT LAKES REGION IN THE W/SW H500 FLOW ALOFT. THE WARM FRONT TO
THE CYCLONE LIFTS NORTHWARD FROM THE OHIO VALLEY. THE ISENTROPIC
LIFT STRENGTHENS FOR A PERIOD OF WET SNOW AND RAIN. THE WET SNOW
WILL LIKELY BE CONFINED TO LOCATIONS NORTH OF THE CAPITAL
REGION...AND OVER THE MOUNTAINS. LOWS WILL GENERALLY BE IN THE
LOWER TO M30S. AS THE WARM FRONT MOVES THROUGH...H850 TEMPS RISE TO
0C TO +6C BY 12Z/FRI.
FRIDAY...THE NAM IS THE FASTEST DEEPENING AND INTENSIFYING THE
CYCLONE TO 983 HPA OVER SRN QUEBEC BY 12Z. THE CAN GGEM/GFS ARE IN
PRETTY GOOD AGREEMENT THE LOW WILL BE NEAR WRN NY AND THE ERN GREAT
LAKES REGION AT THIS TIME...WHILE THE ECMWF IS MUCH SLOWER WITH THE
CYCLONE OVER THE OHIO VALLEY. THE 00Z GLOBAL ENSEMBLE MEAN IS A
COMPROMISE BTWN THE NAM AND THE GFS/CAN GGEM. HPC/S PLACEMENT OF A
992 HPA CYCLONE NEAR NIAGARA FALLS FAVORS THE GFS. THE NRN AND SRN
STREAMS CONTINUE TO SHOW SIGNS OF PHASING NEAR THE NORTHEAST DURING
THE DAY. A BROAD UPPER LEVEL TROUGH IS CARVED OUT OVER THE CENTRAL
PLAINS INTO THE MS RIVER VALLEY WITH THE NRN AND SRN STREAMS PHASING
POTENTIALLY ALONG OR JUST WEST OF THE APPALACHIAN MTNS. THE SURFACE
LOW INTENSIFIES AND DEEPENS...AS IT MOVES ACROSS NY AND NEW ENGLAND
INTO SE QUEBEC. THE ECMWF IS STUBBORNLY SLOWER AND MUCH MORE INTENSE
WITH THE CYCLONE DEVELOPMENT NEAR THE DELMARVA REGION AT 00Z/SAT.
THE GFS HAS A DRY SLOT OVER THE REGION HEADING INTO THE OVERNIGHT
PERIOD. MOST OF THE REGION WILL BE IN A WARM SECTOR WITH PERIODS OF
RAIN. THE QUESTION WILL BE HOW FAST THE COLD AIR MOVES BACK IN FROM
THE NORTH AND WEST WITH THE CYCLONE LIFTING NORTH AND EAST OF THE
REGION. AGAIN...LEANING TOWARDS HPC HERE WITH THE COLDER AIR MOVING
IN TOWARDS NIGHTFALL. HIGHS WILL BE BALMY ON FRIDAY...WITH U40S TO
M50S IN THE VALLEYS...AND LOWER TO M40S OVER THE MTNS.
FRI NIGHT...THE ECMWF HAS AN IMPRESSIVE ISALLOBARIC COUPLET
IMPACTING THE FCST AREA WITH THE STORM DEEPENING AND INTENSIFYING TO
967 HPA JUST NORTHEAST OF MONTREAL BY 12Z/SAT. THE GFS/HPC HAVE THE
DEEP STORM OF ABOUT 980 HPA OVER NRN ME/NEW BRUNSWICK. THE GFS SFC
ISALLOBARIC COUPLET ISN/T ANYWHERE NEAR AS STRONG AS THE ECMWF.
STRONG COLD AIR ADVECTION IMPACTS THE REGION WITH H850 TEMPS FALLING
BACK TO ABOUT -10C. IT WILL BE WINDY...BUT HOW WINDY IS THE
QUESTION AT THIS POINT BASED ON THE MODEL DISCREPANCIES. THE H850
WINDS FROM THE NW ARE ONLY 35-40 KTS BY 12Z/SAT ON THE GFS. WE WILL
CONTINUE TO MONITOR HOWS THINGS EVOLVE OVER THE NEXT FEW DAYS. THE
ECMWF SCENARIO WOULD BE THE WORST CASE SCENARIO WITH A POTENTIALLY
HIGH WIND EVENT. OUR CONFIDENCE IS NOT HIGH ENOUGH YET TO PLACE
THIS IN THE HWO.
SATURDAY...COLD AND WINDY CONDITIONS PREVAIL WITH NORTHWEST FLOW
ALOFT. A SERIES OF DISTURBANCES WILL BE ROTATING AROUND THE STACKED
LOW OVER THE CANADIAN MARITIMES. WE KEPT A CHANCE OF SNOW SHOWERS
IN NORTH AND WEST OF THE CAPITAL DISTRICT...AND A SLIGHT CHC SOUTH
AND EAST. MAX TEMPS WILL BE CLOSER TO SEASONABLE READINGS.
SATURDAY NIGHT...A SECOND COLD FRONT OR SFC TROUGH MOVES THROUGH
WITH H850 TEMPS FALLING TO -12C TO -15C OVER THE REGION. THIS
BOUNDARY HAS LESS MOISTURE TO WORK WITH...AND THE BEST CHC OF SNOW
SHOWERS WILL BE DOWNWIND OF LAKE ONTARIO...AND PREDOMINANTLY WEST OF
THE HUDSON RIVER VALLEY. LOWS WILL BE IN THE UPPER TEENS TO LOWER
20S IN THE VALLEYS...AND SINGLE DIGITS TO MID TEENS OVER THE MTNS.
SUNDAY TO MONDAY...FOLLOWED CLOSE TO HPC WITH HIGH PRESSURE BRIEFLY
BUILDING IN FROM SOUTH OF JAMES BAY TO CLOSE THE WEEKEND. ANY LAKE
EFFECT SNOW SHOWERS OR FLURRIES WILL END. THE NEXT CYCLONE
APPROACHES FROM THE LOWER GREAT LAKES REGION TO OPEN THE WEEK. IT
LOOKS TO PASS NORTH AND WEST OF UPSTATE NY...WITH A SLIGHT TO LOW
CHC OF RAIN AND SNOW SHOWERS. TEMPS MODERATE SLIGHTLY ABOVE NORMAL.
OVERALL...TEMPS WILL STILL RUN ABOVE NORMAL...WITH PRECIPITATION
AMOUNTS IN THE NORMAL RANGE DEPENDING ON THE FRIDAY SYSTEM.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
GUSTY WINDS OUT OF THE SOUTH THIS AFTERNOON AND EARLY
EVENING...WILL SUBSIDE...ONLY TO HAVE SNOW SHOWERS MOVE IN FROM
THE GREAT LAKES REGION AS A WARM FRONT MOVES ACROSS THE AREA
OVERNIGHT.
AS HIGH PRESSURE CONTINUES TO MOVE OFF SHORE AND LOW PRESSURE
OVER THE NORTHERN GREAT LAKES REGION APPROACHES...A TIGHT
PRESSURE GRADIENT WILL CONTINUE TO DEVELOP OVER THE NE...LEADING
TO WINDS GUSTING TO 15-25 KTS AT ALL TERMINALS THIS AFTERNOON. A
WARM FRONT ASSOCIATED WITH THE LOW PRESSURE WILL MAKE ITS WAY
NORTHEASTWARD...INCREASING AND LOWERING CLOUD COVER. VFR CIGS AND
VSBYS EXPECTED THROUGH AT LEAST 03Z...BUT UPSTREAM OBS INDICATE
MVFR CIGS POSSIBLE WITH -SHSN OVERNIGHT. MODELS INDICATE PRECIP
STARTING AROUND 00Z TONIGHT...BUT DRY AIR OVERHEAD WILL TAKE TIME
TO SATURATE. BEST CHC FOR -SHSN WILL BE KALB BRIEFLY AND KGFL.
HAVE THEREFORE INTRODUCED MVFR CIGS AT KALB AND KGFL AROUND
03Z...BUT KALB IMPROVING TO VFR SHORTLY AFTER MIDNIGHT/05Z. BEST
ISENTROPIC LIFT NEAR KGFL...HENCE LONGER DURATION -SHSN AND MVFR
VSBYS. KGFL CONDITIONS EXPECTED TO IMPROVE WEDNESDAY MORNING.
WINDS WILL SUBSIDE OVERNIGHT TO LESS THAN 10KTS OUT OF THE
SOUTH...BUT WINDS ALOFT WILL REMAIN 30-40 KTS...LEADING TO
POSSIBLE WIND SHEAR. HAVE INDICATED LLWS AT KGFL DUE TO BEST
CONFIDENCE...BUT IT MAY BE CLOSE AT OTHER TERMINALS THROUGH
MIDNIGHT. SFC WIND WILL SHIFT SW SOMETIME WEDNESDAY MORNING.
OUTLOOK....
WED...VFR...SLIGHT CHC -SHRA.
WED NIGHT...VFR/MVFR...CHC -SHRA KPOU...SLGT CHC -SHRA/-SHSN NORTH.
THU...VFR...CHC PM -SHRAS.
THU NIGHT...MVFR/VFR. CHC -RA.
FRI...MVFR CIGS/VSBYS...RA LIKELY. BECOMING WINDY.
FRI NGT-SUN...VFR...SLIGHT CHC -SHSN. WINDY.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED THIS WEEK. HIGH PRESSURE WILL MOVE
OFFSHORE TODAY AND THE WEATHER WILL BECOME UNSETTLED FOR THE REST OF
THE WEEK. THE BEST CHANCES FOR WIDESPREAD PRECIPITATION MAINLY IN
THE FORM OF RAIN WILL BE THURSDAY NIGHT AND FRIDAY WITH A TRANSITION
TO PRIMARILY SNOW AS COLDER AIR MOVES IN FRIDAY NIGHT. THE POTENTIAL
FOR FLOODING IS GENERALLY BELOW NORMAL DUE TO BELOW NORMAL SNOWPACK
AND RIVER ICE. PLEASE REFER TO OUR WINTER/SPRING FLOOD POTENTIAL
OUTLOOK (ALBESFALY) ISSUED ON FEBRUARY 16TH FOR DETAILS. NEXT
ISSUANCE OF THIS PRODUCT OS SCHEDULED FOR MARCH 1ST.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.CLIMATE...
LEAST SNOWIEST DEC-JAN-FEB FOR ALBANY NY
YEARS OF RECORD: 1884-2012
1) 8.8 INCHES 2011-12 (THROUGH 2/20)
2) 10.9 INCHES 1936-37
3) 11.7 INCHES 1912-13
4) 13.8 INCHES 1911-12
5) 14.2 INCHES 1988-89
6) 16.3 INCHES 1931-32
7) 16.6 INCHES 1979-80
8) 17.0 INCHES 1954-55
9) 17.1 INCHES 1918-19
17.1 INCHES 1889-90
10) 17.3 INCHES 1910-11
LEAST SNOWIEST SEASONS FOR ALBANY NY
YEARS OF RECORD: 1884-2012
1) 13.8 INCHES 1912-13
2) 14.1 INCHES 2011-12 (THROUGH FEB 20TH)
3) 19.0 INCHES 1988-89
4) 24.8 INCHES 1929-30
5) 26.7 INCHES 1918-19
6) 27.4 INCHES 1979-80
7) 28.1 INCHES 1889-90
8) 28.4 INCHES 1936-37
9) 28.7 INCHES 1990-91
28.7 INCHES 1914-15
11) 28.9 INCHES 1896-97
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA
NEAR TERM...IAA/BGM/JPV
SHORT TERM...IAA
LONG TERM...WASULA
AVIATION...KGM
HYDROLOGY...IAA
CLIMATE...IAA
AREA FORECAST DISCUSSION
NWS ALBANY NY
1229 PM EST TUE FEB 21 2012
.SYNOPSIS...
HIGH PRESSURE WILL SHIFT EASTWARD AND OFFSHORE TODAY WITH CLOUDS ON
THE INCREASE. A WARM FRONT WILL MOVE ACROSS THE REGION TONIGHT
ACCOMPANIED BY RAIN AND SNOW SHOWERS. THE WEATHER WILL REMAIN
UNSETTLED FOR THE REST OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
CI/CS CLOUD CANOPY CONTINUES TO THICKEN AND LOWER AS UPPER LOW
NEAR DETROIT LIFTS NORTHEAST. REGIONAL RADARS SHOW SHOWER ACTIVITY
HAS MOVED INTO EXTREME WESTERN NY AND WESTERN PA. UPSTREAM METARS
SHOW A MIXTURE OF RAIN/SNOW AS THIS WILL BECOME OUR ISSUE LATER
THIS EVENING. AS FOR ARRIVAL TIMING...PER THE HRRR AND
EXTRAPOLATING RADAR TRENDS...SEEMS OUR WESTERN AREAS COULD SEE
PRECIP AS EARLY AS 4 PM EST AND INTO THE HUDSON RIVER VALLEY
AROUND 6 PM. SO HAVE MADE SLIGHT ADJUSTMENTS TO THE POPS/WX GRIDS.
OTHERWISE...TEMPERATURES LOOK ON TRACK AND LITTLE CHANGES NEEDED
AT THIS TIME.
THIS PIECE OF ENERGY WILL LOSE ITS IDENTITY TONIGHT. HOWEVER MORE
ENERGY MOVING THROUGH THE LONGWAVE TROUGH WILL BE ON ITS HEALS.
WILL HAVE WEAK FRONTAL BOUNDARY...OCCLUDING WARM FRONT MOVE ACROSS
THE REGION TONIGHT. THE BEST CHANCES FOR SHOWERS WILL BE ACROSS
THE SOUTHERN ADIRONDACKS WHERE THE BETTER UPPER SUPPORT WILL BE.
IT WILL BE COLD ENOUGH FOR MAINLY SNOW ACROSS THE SOUTHERN
ADIRONDACKS WITH UP TO A COUPLE INCHES OF SNOW EXPECTED.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
MODEL GUIDANCE HAS NOT BEEN CONSISTENT HANDLING THE NEXT SIGNIFICANT
PIECE OF ENERGY MOVING THROUGH THE LONGWAVE PATTERN AND HOW AND
WHERE THE LOW PRESSURE SYSTEM ASSOCIATED WITH IT DEVELOPS. AS FOR
WEDNESDAY AND WEDNESDAY NIGHT...A SURFACE LOW WILL MOVE GRADUALLY
EASTWARD ACROSS ONTARIO AND QUEBEC WHILE THE UPPER TROUGH FLATTENS
OVER OUR REGION. PIECES OF ENERGY WILL MOVE THROUGH THIS FAST FLOW
KEEPING THE THREAT FOR PRECIPITATION IN THE FORECAST. MORE
ORGANIZED/WIDESPREAD PRECIPITATION WILL BEGIN TO MOVE INTO THE
REGION THURSDAY AS A LOW PRESSURE SYSTEM APPROACHES.
EXPECTING EVEN MILDER TEMPERATURES WEDNESDAY WITH SOUTHWESTERLY FLOW
ACROSS THE AREA...SHOULD REACH 50 DEGREES IN THE CAPITAL DISTRICT.
NOT QUITE AS MILD THURSDAY BUT STILL ABOVE NORMAL BY AROUND 10
DEGREES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THE MEDIUM RANGE GUIDANCE CONTINUE TO FORECAST AN ACTIVE WEATHER
PATTERN AT THE END OF THE WEEK...AND THE BEGINNING OF THE WEEKEND.
THERE STILL IS QUITE A BIT OF UNCERTAINTY ON THE
TIMING...EVOLUTION...AND IMPACT OF A SYSTEM FRIDAY INTO
SATURDAY...AND WE ARE LEANING MORE TOWARDS AN HPC/GFS/GLOBAL
ENSEMBLE MEAN SCENARIO INTO THE FIRST HALF OF THE WEEKEND...AND THEN
FOLLOWED CLOSER TO HPC THEREAFTER.
THURSDAY NIGHT...A SFC CYCLONE APPROACHES THE FORECAST AREA FROM THE
GREAT LAKES REGION IN THE W/SW H500 FLOW ALOFT. THE WARM FRONT TO
THE CYCLONE LIFTS NORTHWARD FROM THE OHIO VALLEY. THE ISENTROPIC
LIFT STRENGTHENS FOR A PERIOD OF WET SNOW AND RAIN. THE WET SNOW
WILL LIKELY BE CONFINED TO LOCATIONS NORTH OF THE CAPITAL
REGION...AND OVER THE MOUNTAINS. LOWS WILL GENERALLY BE IN THE
LOWER TO M30S. AS THE WARM FRONT MOVES THROUGH...H850 TEMPS RISE TO
0C TO +6C BY 12Z/FRI.
FRIDAY...THE NAM IS THE FASTEST DEEPENING AND INTENSIFYING THE
CYCLONE TO 983 HPA OVER SRN QUEBEC BY 12Z. THE CAN GGEM/GFS ARE IN
PRETTY GOOD AGREEMENT THE LOW WILL BE NEAR WRN NY AND THE ERN GREAT
LAKES REGION AT THIS TIME...WHILE THE ECMWF IS MUCH SLOWER WITH THE
CYCLONE OVER THE OHIO VALLEY. THE 00Z GLOBAL ENSEMBLE MEAN IS A
COMPROMISE BTWN THE NAM AND THE GFS/CAN GGEM. HPC/S PLACEMENT OF A
992 HPA CYCLONE NEAR NIAGARA FALLS FAVORS THE GFS. THE NRN AND SRN
STREAMS CONTINUE TO SHOW SIGNS OF PHASING NEAR THE NORTHEAST DURING
THE DAY. A BROAD UPPER LEVEL TROUGH IS CARVED OUT OVER THE CENTRAL
PLAINS INTO THE MS RIVER VALLEY WITH THE NRN AND SRN STREAMS PHASING
POTENTIALLY ALONG OR JUST WEST OF THE APPALACHIAN MTNS. THE SURFACE
LOW INTENSIFIES AND DEEPENS...AS IT MOVES ACROSS NY AND NEW ENGLAND
INTO SE QUEBEC. THE ECMWF IS STUBBORNLY SLOWER AND MUCH MORE INTENSE
WITH THE CYCLONE DEVELOPMENT NEAR THE DELMARVA REGION AT 00Z/SAT.
THE GFS HAS A DRY SLOT OVER THE REGION HEADING INTO THE OVERNIGHT
PERIOD. MOST OF THE REGION WILL BE IN A WARM SECTOR WITH PERIODS OF
RAIN. THE QUESTION WILL BE HOW FAST THE COLD AIR MOVES BACK IN FROM
THE NORTH AND WEST WITH THE CYCLONE LIFTING NORTH AND EAST OF THE
REGION. AGAIN...LEANING TOWARDS HPC HERE WITH THE COLDER AIR MOVING
IN TOWARDS NIGHTFALL. HIGHS WILL BE BALMY ON FRIDAY...WITH U40S TO
M50S IN THE VALLEYS...AND LOWER TO M40S OVER THE MTNS.
FRI NIGHT...THE ECMWF HAS AN IMPRESSIVE ISALLOBARIC COUPLET
IMPACTING THE FCST AREA WITH THE STORM DEEPENING AND INTENSIFYING TO
967 HPA JUST NORTHEAST OF MONTREAL BY 12Z/SAT. THE GFS/HPC HAVE THE
DEEP STORM OF ABOUT 980 HPA OVER NRN ME/NEW BRUNSWICK. THE GFS SFC
ISALLOBARIC COUPLET ISN/T ANYWHERE NEAR AS STRONG AS THE ECMWF.
STRONG COLD AIR ADVECTION IMPACTS THE REGION WITH H850 TEMPS FALLING
BACK TO ABOUT -10C. IT WILL BE WINDY...BUT HOW WINDY IS THE
QUESTION AT THIS POINT BASED ON THE MODEL DISCREPANCIES. THE H850
WINDS FROM THE NW ARE ONLY 35-40 KTS BY 12Z/SAT ON THE GFS. WE WILL
CONTINUE TO MONITOR HOWS THINGS EVOLVE OVER THE NEXT FEW DAYS. THE
ECMWF SCENARIO WOULD BE THE WORST CASE SCENARIO WITH A POTENTIALLY
HIGH WIND EVENT. OUR CONFIDENCE IS NOT HIGH ENOUGH YET TO PLACE
THIS IN THE HWO.
SATURDAY...COLD AND WINDY CONDITIONS PREVAIL WITH NORTHWEST FLOW
ALOFT. A SERIES OF DISTURBANCES WILL BE ROTATING AROUND THE STACKED
LOW OVER THE CANADIAN MARITIMES. WE KEPT A CHANCE OF SNOW SHOWERS
IN NORTH AND WEST OF THE CAPITAL DISTRICT...AND A SLIGHT CHC SOUTH
AND EAST. MAX TEMPS WILL BE CLOSER TO SEASONABLE READINGS.
SATURDAY NIGHT...A SECOND COLD FRONT OR SFC TROUGH MOVES THROUGH
WITH H850 TEMPS FALLING TO -12C TO -15C OVER THE REGION. THIS
BOUNDARY HAS LESS MOISTURE TO WORK WITH...AND THE BEST CHC OF SNOW
SHOWERS WILL BE DOWNWIND OF LAKE ONTARIO...AND PREDOMINANTLY WEST OF
THE HUDSON RIVER VALLEY. LOWS WILL BE IN THE UPPER TEENS TO LOWER
20S IN THE VALLEYS...AND SINGLE DIGITS TO MID TEENS OVER THE MTNS.
SUNDAY TO MONDAY...FOLLOWED CLOSE TO HPC WITH HIGH PRESSURE BRIEFLY
BUILDING IN FROM SOUTH OF JAMES BAY TO CLOSE THE WEEKEND. ANY LAKE
EFFECT SNOW SHOWERS OR FLURRIES WILL END. THE NEXT CYCLONE
APPROACHES FROM THE LOWER GREAT LAKES REGION TO OPEN THE WEEK. IT
LOOKS TO PASS NORTH AND WEST OF UPSTATE NY...WITH A SLIGHT TO LOW
CHC OF RAIN AND SNOW SHOWERS. TEMPS MODERATE SLIGHTLY ABOVE NORMAL.
OVERALL...TEMPS WILL STILL RUN ABOVE NORMAL...WITH PRECIPITATION
AMOUNTS IN THE NORMAL RANGE DEPENDING ON THE FRIDAY SYSTEM.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
VFR CONDITIONS WILL PREVAIL THE NEXT 12-18 HOURS WITH HIGH PRESSURE
IN CONTROL INTO THE AFTERNOON. A WARM FRONT WILL APPROACH FROM THE
OHIO VALLEY. THIS BOUNDARY WILL BRING AN INCREASE OF CLOUDS...A
CHANCE OF RAIN OR SNOW SHOWERS...AND LOW LEVEL WIND SHEAR CONDITIONS
AFTER 23Z FOR NORTH OF KALB.
HIGH CLOUDS WILL INCREASE WITH THE SFC HIGH MOVING OFF THE NEW
ENGLAND COAST INTO THE AFTERNOON. THE CLOUDS WILL CONTINUE TO
THICKEN AND LOWER INTO THE EARLY EVENING WITH BASES LOWERING TO 5-7
KFT AGL AFTER 00Z/WED. THE WINDS AT THE 2 KFT AGL WILL INCREASE TO
35-40 KTS. THE SFC WINDS WINDS MAY DECREASE TO 5 KTS OR LESS AFTER
DARK ESPECIALLY AT KGFL. A LLWS GROUP WAS ADDED AT KGFL WHERE OUR
CONFIDENCE WAS GREATEST. KPOU IS MARGINALLY CLOSE TO LLWS
CONDITIONS...AND MAY BE NECESSARY WITH LATER TAF ISSUANCES...IF
CONFIDENCE INCREASES.
SOME SCT SNOW SHOWERS WILL DEVELOP AHEAD OF THE WARM FRONT...AS CIGS
AND VSBYS WILL LOWER TO MVFR LEVELS ESPECIALLY NORTH OF KALB. FOR
NOW...WE CONTINUED LOW VFR CIGS FROM KALB SOUTH. WE ALSO INCLUDED
VCSH GROUPS FOR KPOU AND KALB AT 00Z AND 03Z RESPECTIVELY.
THE WINDS WILL BE SOUTHERLY AT 7-12 KTS IN THE LATE MORNING THRU THE
AFTERNOON...WITH A FEW GUSTS CLOSE TO 20 KTS AT KALB. THE SFC WINDS
WILL LIGHTEN TO 10 KTS OR LESS AFTER 00Z/WED.
OUTLOOK....
WED...VFR. SLIGHT CHC -SHRA.
WED NIGHT...VFR/MVFR...CHC -SHRA KPOU...SLGT CHC -SHRA/-SHSN NORTH.
THU...VFR...CHC PM -SHRAS.
THU NIGHT...MVFR/VFR. CHC -RA.
FRI...MVFR CIGS/VSBYS. RA LIKELY. BECOMING WINDY.
FRI NGT-SAT...VFR. SLIGHT CHC -SHSN. WINDY.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED THIS WEEK. HIGH PRESSURE WILL MOVE
OFFSHORE TODAY AND THE WEATHER WILL BECOME UNSETTLED FOR THE REST OF
THE WEEK. THE BEST CHANCES FOR WIDESPREAD PRECIPITATION MAINLY IN
THE FORM OF RAIN WILL BE THURSDAY NIGHT AND FRIDAY WITH A TRANSITION
TO PRIMARILY SNOW AS COLDER AIR MOVES IN FRIDAY NIGHT. THE POTENTIAL
FOR FLOODING IS GENERALLY BELOW NORMAL DUE TO BELOW NORMAL SNOWPACK
AND RIVER ICE. PLEASE REFER TO OUR WINTER/SPRING FLOOD POTENTIAL
OUTLOOK (ALBESFALY) ISSUED ON FEBRUARY 16TH FOR DETAILS. NEXT
ISSUANCE OF THIS PRODUCT OS SCHEDULED FOR MARCH 1ST.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.CLIMATE...
LEAST SNOWIEST DEC-JAN-FEB FOR ALBANY NY
YEARS OF RECORD: 1884-2012
1) 8.8 INCHES 2011-12 (THROUGH 2/20)
2) 10.9 INCHES 1936-37
3) 11.7 INCHES 1912-13
4) 13.8 INCHES 1911-12
5) 14.2 INCHES 1988-89
6) 16.3 INCHES 1931-32
7) 16.6 INCHES 1979-80
8) 17.0 INCHES 1954-55
9) 17.1 INCHES 1918-19
17.1 INCHES 1889-90
10) 17.3 INCHES 1910-11
LEAST SNOWIEST SEASONS FOR ALBANY NY
YEARS OF RECORD: 1884-2012
1) 13.8 INCHES 1912-13
2) 14.1 INCHES 2011-12 (THROUGH FEB 20TH)
3) 19.0 INCHES 1988-89
4) 24.8 INCHES 1929-30
5) 26.7 INCHES 1918-19
6) 27.4 INCHES 1979-80
7) 28.1 INCHES 1889-90
8) 28.4 INCHES 1936-37
9) 28.7 INCHES 1990-91
28.7 INCHES 1914-15
11) 28.9 INCHES 1896-97
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA
NEAR TERM...IAA/BGM/JPV
SHORT TERM...IAA
LONG TERM...WASULA
AVIATION...WASULA
HYDROLOGY...IAA
CLIMATE...IAA
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1121 AM CST TUE FEB 21 2012
.DISCUSSION...
ISSUED 1010 AM CST TUE FEB 21 2012
COLD FRONT CONTINUES TO APPROACH THE CWA LATE THIS MORNING...
CURRENTLY ANALYZED FROM ABOUT KANSAS CITY NORTHEAST INTO CENTRAL
WISCONSIN. LARGE AREA OF STRATOCUMULUS AHEAD OF THE FRONT SHOWED A
FEW HOLES EARLIER WHICH HAVE LARGELY FILLED...BUT TRAILING EDGE OF
THE CLOUD DECK JUST STARTING TO CROSS THE MISSISSIPPI RIVER AROUND
QUINCY. LAYER HUMIDITY PLOTS FROM RUC AND NAM SHOWING THIS BACK
EDGE OF THE LOW CLOUDS SHOULD BE ADVANCING NORTHEAST ACROSS THE
CWA THROUGH MID AFTERNOON...HOWEVER SOME MID AND HIGH CLOUDS MOVING
IN AT THE SAME TIME WILL FILTER THE SUNSHINE THAT WOULD OTHERWISE
HAVE OCCURRED.
HAVE SENT SOME MINOR TWEAKS TO THE ZONES/GRIDS...MAINLY TO REMOVE
THE RAIN CHANCES TODAY AND UPDATE THE HOURLY SKY/TEMPERATURE
TRENDS.
GEELHART
&&
.AVIATION...
ISSUED 1120 AM CST TUE FEB 21 2012
MAIN CONCERN IS WITH CEILINGS EARLY THIS AFTERNOON. MVFR CEILINGS
COVERING MOST OF THE AREA LATE THIS MORNING...WITH SOME POCKETS
BELOW 1000 FEET ESPECIALLY FROM KBMI NORTHWEST. BACK EDGE OF THE
LOW CLOUDS WAS ROUGHLY FROM KMUT-KMQB-KPPQ AT 17Z. CLOUD EDGE IS
STEADILY MOVING EASTWARD...AND AWIPS TIME-OF-ARRIVAL TOOL HAS IT
REACHING KCMI KCMI TOWARD 21Z. GUSTY SOUTHWEST WINDS TO BECOME
MORE WESTERLY AS A COLD FRONT ADVANCES...WITH SOME GUSTS TO AROUND
25 KNOTS THROUGH SUNSET. VFR CONDITIONS EXPECTED THE REMAINDER OF
THE PERIOD...ONCE THESE LOW CLOUDS EXIT. CEILINGS MAINLY AROUND
6000 FEET EXPECTED OVERNIGHT AND EARLY WEDNESDAY...ALTHOUGH MODEL
CROSS SECTIONS HINT AT A COUPLE HOURS AROUND 12Z WHERE THE
CEILINGS MAY BREAK FOR A TIME.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 239 AM CST TUE FEB 21 2012
SHORT TERM...TODAY THROUGH THURSDAY
VIGOROUS UPPER-LEVEL LOW CURRENTLY OVER MISSOURI WILL TRACK
EASTWARD ACROSS CENTRAL ILLINOIS THIS MORNING. BULK OF SHOWER
ACTIVITY ASSOCIATED WITH THIS FEATURE WILL LIFT N/NE OF THE AREA
BY 12Z...HOWEVER RADAR MOSAIC IS INDICATING SCATTERED LIGHT
SHOWERS DEVELOPING IMMEDIATELY BENEATH THE LOW...SO THINK RAIN
CHANCES ARE STILL WARRANTED THROUGH MIDDAY. ONCE THE LOW SHIFTS
FURTHER EAST...SYNOPTIC SUBSIDENCE ON ITS BACK SIDE WILL RESULT IN
CLEARING SKIES FROM WEST TO EAST DURING THE AFTERNOON. MID/HIGH
CLOUDS CURRENTLY UPSTREAM OVER NEBRASKA WILL STREAM EASTWARD INTO
THE AREA TOWARD EVENING...SO SUNSHINE WILL DEFINITELY BE LIMITED
TODAY. HIGH TEMPS WILL ONCE AGAIN BE ON THE MILD SIDE...WITH
READINGS TOPPING OUT IN THE MIDDLE TO UPPER 40S IN MOST LOCATIONS.
WEAK SHORT-WAVE WILL SKIRT THROUGH THE MIDWEST ON WEDNESDAY...HOWEVER
LACK OF DEEP ATMOSPHERIC MOISTURE WILL PREVENT ANY PRECIP FROM
DEVELOPING. MOSTLY CLOUDY AND DRY CONDITIONS WILL PREVAIL...WITH
HIGHS REACHING THE LOWER TO MIDDLE 50S THANKS TO A SUSTAINED
SOUTHERLY FLOW.
STRONGER WAVE CURRENTLY OVER THE GULF OF ALASKA WILL DROP
SOUTHEASTWARD THROUGH THE NORTHERN ROCKIES INTO THE PLAINS ON
THURSDAY...PUSHING A COLD FRONT INTO CENTRAL ILLINOIS LATE IN THE
DAY. WITH STRONGER UPPER DYNAMICS AND SOMEWHAT MORE FAVORABLE
MOISTURE PROFILES IN PLACE...THINK SCATTERED SHOWERS WILL DEVELOP
AHEAD OF THE FRONT. HAVE THEREFORE INCLUDED LOW CHANCE POPS ACROSS
THE BOARD ON THURSDAY...THEN ACROSS THE E/SE KILX CWA THURSDAY
NIGHT AS THE FRONT PUSHES FURTHER EAST.
LONG TERM...FRIDAY THROUGH MONDAY
DEEP TROUGH WILL DIG ACROSS THE MIDWEST/GREAT LAKES ON
FRIDAY/SATURDAY...RESULTING IN A TEMPORARY COOLING TREND. WITH
CYCLONIC FLOW AND VERY COLD 500MB TEMPS IN PLACE...COULD
POTENTIALLY SEE A FEW SCATTERED RAIN/SNOW SHOWERS ON
FRIDAY...HOWEVER THINK AREAL COVERAGE WILL BE MINIMAL DUE TO LACK
OF STRONG FOCUSING MECHANISM. WILL THEREFORE ONLY MENTION SLIGHT
CHANCE POPS AT THIS TIME. MAIN STORY WILL BE THE COOLER
TEMPS...WITH HIGHS ONLY REACHING THE UPPER 30S/LOWER 40S.
MODELS CONTINUE TO STRUGGLE WITH THE RAPIDLY EVOLVING UPPER
PATTERN LATE IN THE WEEKEND...WITH THE 00Z 21 FEB MODELS SHOWING
DRASTICALLY DIFFERENT SOLUTIONS. ECMWF/CANADIAN BOTH DIG A
PROMINENT TROUGH OVER THE WESTERN CONUS BY SUNDAY...RESULTING IN
RIDGING DOWNSTREAM OVER THE MIDWEST. ASSOCIATED 993MB SURFACE LOW
IS POSITIONED IN EASTERN COLORADO BY 00Z MON. MEANWHILE...THE GFS
IS MUCH WEAKER/MORE PROGRESSIVE WITH THE TROUGH...TRACKING IT
EASTWARD INTO THE MIDWEST MUCH FASTER. ITS SURFACE LOW PRESSURE IS
LOCATED OVER NORTHERN ILLINOIS BY 00Z MON. GIVEN POOR RUN-TO-RUN
CONSISTENCY...FORECAST CONFIDENCE REMAINS LOW BEYOND SATURDAY. WILL
HOWEVER TREND TOWARD THE ECMWF/CANADIAN CONSENSUS FOR THE LATTER
HALF OF THE EXTENDED. THIS WOULD RESULT IN WARM/DRY CONDITIONS ON
SUNDAY...FOLLOWED BY RAIN CHANCES ARRIVING BY MONDAY.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1010 AM CST TUE FEB 21 2012
.DISCUSSION...
ISSUED 1010 AM CST TUE FEB 21 2012
COLD FRONT CONTINUES TO APPROACH THE CWA LATE THIS MORNING...
CURRENTLY ANALYZED FROM ABOUT KANSAS CITY NORTHEAST INTO CENTRAL
WISCONSIN. LARGE AREA OF STRATOCUMULUS AHEAD OF THE FRONT SHOWED A
FEW HOLES EARLIER WHICH HAVE LARGELY FILLED...BUT TRAILING EDGE OF
THE CLOUD DECK JUST STARTING TO CROSS THE MISSISSIPPI RIVER AROUND
QUINCY. LAYER HUMIDITY PLOTS FROM RUC AND NAM SHOWING THIS BACK
EDGE OF THE LOW CLOUDS SHOULD BE ADVANCING NORTHEAST ACROSS THE
CWA THROUGH MID AFTERNOON...HOWEVER SOME MID AND HIGH CLOUDS MOVING
IN AT THE SAME TIME WILL FILTER THE SUNSHINE THAT WOULD OTHERWISE
HAVE OCCURRED.
HAVE SENT SOME MINOR TWEAKS TO THE ZONES/GRIDS...MAINLY TO REMOVE
THE RAIN CHANCES TODAY AND UPDATE THE HOULRY SKY/TEMPERATURE
TRENDS.
GEELHART
&&
.AVIATION...
ISSUED 538 AM CST TUE FEB 21 2012
EXCEPT FOR BMI AND CMI HAVING SOME SCATTERED SHOWERS FOR THE FIRST
HOUR OF THE TAFS...ALL SITES WILL START WITH MVFR CIGS AROUND
2-2.5KFT. BMI AND CMI WILL SEE THESE LOWER CIGS BY 13Z. CIGS WILL
THEN DROP LITTLE MORE AT ALL LOCATIONS AS THE WINDS PICK UP AROUND
14Z...THOUGH CIGS WILL REMAIN IN THE MVFR CATEGORY WITH BMI AND
CMI BELOW 2KFT. THESE LOWER CIGS WILL CONTINUE REST OF THE MORNING
AND THEN IMPROVE IN THE EARLY AFTERNOON. SATELLITE LOOPS SHOWS
THIS CLEARING LINE MOVING EASTWARD INTO PARTS OF MISSOURI AND
IOWA. TIMING TOOL INDICATES THIS CLEARING LINE SHOULD REACH
PIA/SPI EARLY AFTERNOON...FOLLOWED BY DEC/BMI AND THEN CMI
LAST...DURING LATE AFTERNOON. HIGHER SUN ANGLE SHOULD ALSO HELP IN
BURNING OFF BACK EDGE AS IT MOVES EAST. HOWEVER...CIRRUS/HIGH AC
WILL ADVECT INTO THE AREA AT THE SAME TIME AS THE
CLEARING...KEEPING SOME CLOUDS OVER THE SITES DURING THE LATE
AFTERNOON AND INTO THE EARLY EVENING HOURS. MODELS INDICATE
MORE LOW VFR CLOUDS AROUND 4-6KFT ARRIVING DURING THE EVENING
HOURS AT ALL SITES AND LASTING TIL MORNING. SOUTH WINDS WILL
BECOME SOUTHWEST AND INCREASE IN SPEED...BECOMING GUSTY AROUND
23-25KTS FOR THE DAY. WINDS WILL SHIFT IN THE AFTERNOON AND BECOME
WESTERLY...THEN RETURN TO SOUTHWEST FOR THE EVENING AND OVERNIGHT
HOURS. SPEEDS WILL BE LIGHTER AFTER SUNSET.
AUTEN
&&
.PREV DISCUSSION...
ISSUED 239 AM CST TUE FEB 21 2012
SHORT TERM...TODAY THROUGH THURSDAY
VIGOROUS UPPER-LEVEL LOW CURRENTLY OVER MISSOURI WILL TRACK
EASTWARD ACROSS CENTRAL ILLINOIS THIS MORNING. BULK OF SHOWER
ACTIVITY ASSOCIATED WITH THIS FEATURE WILL LIFT N/NE OF THE AREA
BY 12Z...HOWEVER RADAR MOSAIC IS INDICATING SCATTERED LIGHT
SHOWERS DEVELOPING IMMEDIATELY BENEATH THE LOW...SO THINK RAIN
CHANCES ARE STILL WARRANTED THROUGH MIDDAY. ONCE THE LOW SHIFTS
FURTHER EAST...SYNOPTIC SUBSIDENCE ON ITS BACK SIDE WILL RESULT IN
CLEARING SKIES FROM WEST TO EAST DURING THE AFTERNOON. MID/HIGH
CLOUDS CURRENTLY UPSTREAM OVER NEBRASKA WILL STREAM EASTWARD INTO
THE AREA TOWARD EVENING...SO SUNSHINE WILL DEFINITELY BE LIMITED
TODAY. HIGH TEMPS WILL ONCE AGAIN BE ON THE MILD SIDE...WITH
READINGS TOPPING OUT IN THE MIDDLE TO UPPER 40S IN MOST LOCATIONS.
WEAK SHORT-WAVE WILL SKIRT THROUGH THE MIDWEST ON WEDNESDAY...HOWEVER
LACK OF DEEP ATMOSPHERIC MOISTURE WILL PREVENT ANY PRECIP FROM
DEVELOPING. MOSTLY CLOUDY AND DRY CONDITIONS WILL PREVAIL...WITH
HIGHS REACHING THE LOWER TO MIDDLE 50S THANKS TO A SUSTAINED
SOUTHERLY FLOW.
STRONGER WAVE CURRENTLY OVER THE GULF OF ALASKA WILL DROP
SOUTHEASTWARD THROUGH THE NORTHERN ROCKIES INTO THE PLAINS ON
THURSDAY...PUSHING A COLD FRONT INTO CENTRAL ILLINOIS LATE IN THE
DAY. WITH STRONGER UPPER DYNAMICS AND SOMEWHAT MORE FAVORABLE
MOISTURE PROFILES IN PLACE...THINK SCATTERED SHOWERS WILL DEVELOP
AHEAD OF THE FRONT. HAVE THEREFORE INCLUDED LOW CHANCE POPS ACROSS
THE BOARD ON THURSDAY...THEN ACROSS THE E/SE KILX CWA THURSDAY
NIGHT AS THE FRONT PUSHES FURTHER EAST.
LONG TERM...FRIDAY THROUGH MONDAY
DEEP TROUGH WILL DIG ACROSS THE MIDWEST/GREAT LAKES ON
FRIDAY/SATURDAY...RESULTING IN A TEMPORARY COOLING TREND. WITH
CYCLONIC FLOW AND VERY COLD 500MB TEMPS IN PLACE...COULD
POTENTIALLY SEE A FEW SCATTERED RAIN/SNOW SHOWERS ON
FRIDAY...HOWEVER THINK AREAL COVERAGE WILL BE MINIMAL DUE TO LACK
OF STRONG FOCUSING MECHANISM. WILL THEREFORE ONLY MENTION SLIGHT
CHANCE POPS AT THIS TIME. MAIN STORY WILL BE THE COOLER
TEMPS...WITH HIGHS ONLY REACHING THE UPPER 30S/LOWER 40S.
MODELS CONTINUE TO STRUGGLE WITH THE RAPIDLY EVOLVING UPPER
PATTERN LATE IN THE WEEKEND...WITH THE 00Z 21 FEB MODELS SHOWING
DRASTICALLY DIFFERENT SOLUTIONS. ECMWF/CANADIAN BOTH DIG A
PROMINENT TROUGH OVER THE WESTERN CONUS BY SUNDAY...RESULTING IN
RIDGING DOWNSTREAM OVER THE MIDWEST. ASSOCIATED 993MB SURFACE LOW
IS POSITIONED IN EASTERN COLORADO BY 00Z MON. MEANWHILE...THE GFS
IS MUCH WEAKER/MORE PROGRESSIVE WITH THE TROUGH...TRACKING IT
EASTWARD INTO THE MIDWEST MUCH FASTER. ITS SURFACE LOW PRESSURE IS
LOCATED OVER NORTHERN ILLINOIS BY 00Z MON. GIVEN POOR RUN-TO-RUN
CONSISTENCY...FORECAST CONFIDENCE REMAINS LOW BEYOND SATURDAY. WILL
HOWEVER TREND TOWARD THE ECMWF/CANADIAN CONSENSUS FOR THE LATTER
HALF OF THE EXTENDED. THIS WOULD RESULT IN WARM/DRY CONDITIONS ON
SUNDAY...FOLLOWED BY RAIN CHANCES ARRIVING BY MONDAY.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
931 PM EST WED FEB 22 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...A CHAOTIC WEATHER PATTERN FOR THE NEXT FEW DAYS WILL
LEAD TO CHANCES FOR RAIN...THUNDERSTORMS...AND SNOW OVER THE NEXT
COUPLE OF DAYS. QUIET WEATHER FOR THE WEEKEND WILL GIVE WAY TO LOW
CHANCES FOR RAIN OR SNOW EARLY IN THE WORK WEEK.
&&
.NEAR TERM /TONIGHT/...
EVENING UPDATE #2...THIN CONVECTIVE LINE HAS QUICKLY DEVELOPED
OVER SOUTHWEST INDIANA JUST SOUTH OF THE FORECAST AREA OVER THE
LAST 30-45 MINUTES. THIS APPEARS TO BE ALONG THE WEAK BOUNDARY
PROGRESSING THROUGH THE SOUTHERN PART OF THE FORECAST AREA.
MESOANALYSIS ALSO SHOWING THAT THIS AREA SITS RIGHT ON THE EDGE OF
THE INSTABILITY AXIS EXTENDING SOUTH INTO THE LOWER MISSISSIPPI
VALLEY. ALSO APPEARS TO HAVE SOME UPPER SUPPORT AIDING DEVELOPMENT
AS TROUGH AXIS ALOFT IS OVERHEAD. HRRR HAS A NICE HANDLE ON
CURRENT DEVELOPMENT...EXPANDING IT EAST ALONG THE OHIO RIVER
VALLEY THIS EVENING. HAVE INSERTED LOW CHANCE POPS OVER FAR
SOUTHERN COUNTIES TO ACCOUNT FOR NORTHERN PART OF THE LINE
CLIPPING SOUTHERN PORTIONS OF THE FORECAST AREA THROUGH THE
EVENING. ANY PRECIP SHOULD BE EAST OF THE FORECAST AREA BY
MIDNIGHT AS WEAK RIDGING BUILDS IN.
PREVIOUS DISCUSSION FOLLOWS.
QUICK UPDATE TO ADDRESS THE GUSTY WINDS PERSISTING ALONG AND AHEAD
OF A WEAK BOUNDARY. HAVE SEEN MAX WIND GUSTS IN EXCESS OF 30MPH OVER
THE LAST HOUR OR TWO...ESPECIALLY NEAR AND SOUTH OF I-70. REPORTS OF
VIRGA DUE TO DRY AIR THROUGH THE BOUNDARY LAYER AND RADAR RETURNS
CURRENTLY SUPPORTING THIS. WITH 35-40KT JET NOTED ALOFT AT
850MB...THERE IS LIKELY SOME MIXING DOWN OF THE STRONGER WINDS AT
4-5KFT GOING ON AND CONTRIBUTING TO THE ENHANCEMENT IN WIND GUSTS.
HAVE THEREFORE BUMPED UP WIND GUSTS FOR THE DURATION OF THE
EVENING...ESPECIALLY NEAR AND SOUTH OF I-70. WINDS SHOULD DROP OFF
BY LATE EVENING AS LOW LEVEL JET SHIFTS EAST WITH SURFACE BOUNDARY.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
THERE IS QUITE A BIT OF DISAGREEMENT AMONG THE MODELS ON THE TRACK
OF THE SURFACE LOW THURSDAY INTO FRIDAY AND THIS WILL HAVE A BIG
IMPACT ON THE WEATHER THAT ENSUES. THE ECMWF TAKES THE LOW SOUTH OF
THE AREA WITH AGREEMENT FROM THE UKMET AND ECMWF ENSEMBLES...WHILE
THE GFS/NAM/ AND SREFS TAKE THE TRACK THROUGH ACROSS THE NORTHERN
PART OR JUST NORTH OF THE AREA. THE GEM SEEMED TO BE A SOLUTION IN
BETWEEN THOSE TWO CAMPS AND THUS TRENDED TOWARD IT.
A WARM FRONT SHOULD BE FORMING ACROSS OR JUST SOUTH OF THE AREA
THURSDAY MORNING AND THIS SHOULD PROVIDE FORCING FOR OVERRUNNING
RAIN SHOWERS WITH THE BEST CHANCES IN THE NORTHERN COUNTIES. AS THE
LOW PRESSURE MOVES ACROSS OR BY THE AREA THROUGH THE DAY IT COULD
DRAG A COLD FRONT THROUGH BY AROUND 0Z...AND WITH A 40 KT LOW LEVEL
JET FORMING UP SOUTH OF THE AREA IN THE AFTERNOON AND SOME ELEVATED
INSTABILITY AVAILABLE COULD SEE SOME THUNDERSTORMS FORM IN THE
AFTERNOON ESPECIALLY IN THE SOUTHERN COUNTIES. WHILE SPC GENERAL
THUNDER OUTLOOK ENCOMPASSES THE ENTIRE FORECAST AREA...THINK THAT
THE BEST CHANCES WILL REMAIN IN THE SOUTHERN COUNTIES WITH ONLY
ISOLATED THUNDER CENTRAL AND PROBABLY NO THUNDER IN THE NORTH. WHILE
AN ISOLATED SEVERE STORM IN THE SOUTH CANNOT BE RULED OUT...BEST
CHANCES FOR SEVERE SHOULD REMAIN SOUTH OF THE AREA.
BY THURSDAY NIGHT THE SYSTEM SHOULD BE MOVING OUT OF THE
AREA...ALTHOUGH SOME UPPER FORCING WILL REMAIN WEST OF THE AREA.
COLD AIR IS LAGGING BEHIND THE FRONT AND THUS WILL KEEP CHANCES FOR
RAIN ACROSS ALL BUT THE NORTHWEST WHERE SNOW COULD MIX IN BEFORE
6Z...AND EXPAND THE MIX ACROSS THE AREA FROM 6-12Z. COULD SEE SOME
STRONG WINDS IN THE WAKE OF THE LOW ON THURSDAY NIGHT AND FRIDAY
DEPENDING ON THE EXACT TRACK. FOR FRIDAY KEPT A CHANCE FOR RAIN OR
SNOW GOING FOR MOST OF THE AREA WITH RAIN CHANCE IN THE FAR SOUTH
BASED ON THE LITTLE FORCING LEFT FROM THE UPPER TROUGH...BUT NOT
ENOUGH TO GO BEYOND A SMALL CHANCE. THE SYSTEM WILL MOVE OUT ON
FRIDAY NIGHT LEAVING A CHANCE FOR SNOW IN THE NORTHEAST AS IT
EXITS...AND BY SATURDAY THE AREA SHOULD BE DRY.
FOR TEMPERATURES GENERALLY USED A CONSENSUS WITH A NUDGE TOWARD THE
GEM.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AN UPPER TROUGH MOVING ACROSS THE NORTHERN U.S. WILL AFFECT OUR
WEATHER AROUND MONDAY. HOWEVER MODELS HAVE TRENDED WITH LESS PRECIP
WITH THIS SYSTEM. I AM NOT CONFIDENT ENOUGH TO TAKE OUT CHANCE OF
PRECIP MONDAY...BUT WILL DROP MENTION ACROSS OUR SOUTHEAST HALF
SUNDAY NIGHT AND ALL AREAS MONDAY MONDAY NIGHT.
A SECOND AND POTENTIALLY MUCH STRONGER SYSTEM WILL AFFECT OUR
WEATHER BY THE MIDDLE OF NEXT WEEK. BOTH 12Z EURO AND 12Z GFS BRINGS
SIGNIFICANT PRECIP BY DAY 7. THERE IS A LOT OF DISAGREEMENT IN THE
SURFACE LOW TRACK AND ULTIMATELY PRECIP TYPE. AT THIS TIME MY
CONFIDENCE IS LOW...SO FOR NOW WILL RAISE ALL BLEND TEMPS TUESDAY
NIGHT AND LOWER THEM WEDNESDAY TO REDUCE THE DIURNAL RANGE. THIS
WOULD GIVE ME SNOW TUESDAY NIGHT WITH MIXED PRECIP SOUTH AND MOSTLY
RAIN WEDNESDAY. CONFIDENCE IS LOW ON PRECIP TYPE...BUT THIS MIDDLE
OF THE ROAD APPROACH SEEMS BEST WAY TO GO UNTIL MODELS HAVE A BETTER
AGREEMENT.
&&
.AVIATION /UPDATE TO KIND 230000Z TAF/...
GUSTINESS HAS ENDED FOR KIND AS WEAK SURFACE CONVERGENT ZONE OVER
SOUTHERN INDIANA SAGS SOUTH TOWARD THE OHIO RIVER. MID CLOUD DECK
OVERCAST MAY SCATTER FOR AWHILE THIS EVENING BEFORE MORE MID CLOUD
FROM APPROACHING SYSTEM PUSHES IN AFTER MIDNIGHT.
KHUF AND KBMG STILL BEING IMPACTED BY WEAK WAVE TO THE SOUTH THAT
IS CONTINUING GUSTY WINDS BUT THESE SHOULD END AT THESE LOCATIONS
BEFORE 230400Z.
EARLIER DISCUSSION...
WEAK LOW PRESSURE MOVING ACROSS CENTRAL INDIANA WITH A MID CLOUD
DECK AND WILL CARRY SOME GUSTY WIND UNTIL ABOUT START OF TAF TIME.
RADAR SHOWING SOME LIGHT ECHOES BUT LITTLE IF ANY REACHING GROUND.
MAIN IMPACT IN THIS FORECAST PERIOD WILL BE SYSTEM COMING OUT OF
THE ROCKIES. FAIRLY DRY AIR IN PLACE...DESPITE MOISTENING SOME
WITH SCT SHRA THURSDAY...SHOULD STILL REMAIN VFR THROUGH THE
FORECAST THOUGH BRIEF PERIOD OF MVFR CIGS AND VSBY POSSIBLE
DURING PERIODS WHEN SHOWERS ARE HEAVIER.
MODELS STILL DIFFER ON DEVELOPING SURFACE LOW TRACK ACROSS EITHER
CENTRAL OR SOUTHERN INDIANA AFTER 231800Z. MAJORITY OF RAIN WILL
FALL ACROSS NORTHERN INDIANA THOUGH PERIODS OF SHOWERS ARE LIKELY
AT TAF SITES AFTER 231300Z...RANGING FROM SHORT LIVED AT KBMG TO
MUCH OF DAY AT KLAF NEARER DEEPEST MOISTURE.
FOR WINDS...AFTER GUSTS DIE DOWN EARLY THIS EVENING...AS SURFACE
LOW MOVES INTO IOWA AND MISSOURI BY 231200Z...SURFACE WINDS
GENERALLY BACK TO SE AROUND 10KTS TOWARD SUNRISE. SHOULD SURFACE LOW
TRACK ACROSS SOUTHERN INDIANA THEN SURFACE WINDS WILL BACK MORE TO
BECOME EASTERLY. RIGHT NOW THOUGHT IS SURFACE LOW WILL COME OVER
TAF SITES BRINGING ALL BUT KLAF WINDS AROUND TO SOUTH AND SW
231800Z- 2100Z TIME FRAME. KLAF WILL REMAIN FAR ENOUGH TO NORTH OF
THE LOW CENTER THAT WINDS SHOULD REMAIN SE OR BACK TO EAST BY
232100Z.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...RYAN
SHORT TERM...CP
LONG TERM....JH
AVIATION...TUCEK
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
840 PM EST WED FEB 22 2012
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...A CHAOTIC WEATHER PATTERN FOR THE NEXT FEW DAYS WILL
LEAD TO CHANCES FOR RAIN...THUNDERSTORMS...AND SNOW OVER THE NEXT
COUPLE OF DAYS. QUIET WEATHER FOR THE WEEKEND WILL GIVE WAY TO LOW
CHANCES FOR RAIN OR SNOW EARLY IN THE WORK WEEK.
&&
.NEAR TERM /TONIGHT/...
EVENING UPDATE #2...THIN CONVECTIVE LINE HAS QUICKLY DEVELOPED
OVER SOUTHWEST INDIANA JUST SOUTH OF THE FORECAST AREA OVER THE
LAST 30-45 MINUTES. THIS APPEARS TO BE ALONG THE WEAK BOUNDARY
PROGRESSING THROUGH THE SOUTHERN PART OF THE FORECAST AREA.
MESOANALYSIS ALSO SHOWING THAT THIS AREA SITS RIGHT ON THE EDGE OF
THE INSTABILITY AXIS EXTENDING SOUTH INTO THE LOWER MISSISSIPPI
VALLEY. ALSO APPEARS TO HAVE SOME UPPER SUPPORT AIDING DEVELOPMENT
AS TROUGH AXIS ALOFT IS OVERHEAD. HRRR HAS A NICE HANDLE ON
CURRENT DEVELOPMENT...EXPANDING IT EAST ALONG THE OHIO RIVER
VALLEY THIS EVENING. HAVE INSERTED LOW CHANCE POPS OVER FAR
SOUTHERN COUNTIES TO ACCOUNT FOR NORTHERN PART OF THE LINE
CLIPPING SOUTHERN PORTIONS OF THE FORECAST AREA THROUGH THE
EVENING. ANY PRECIP SHOULD BE EAST OF THE FORECAST AREA BY
MIDNIGHT AS WEAK RIDGING BUILDS IN.
PREVIOUS DISCUSSION FOLLOWS.
QUICK UPDATE TO ADDRESS THE GUSTY WINDS PERSISTING ALONG AND AHEAD
OF A WEAK BOUNDARY. HAVE SEEN MAX WIND GUSTS IN EXCESS OF 30MPH OVER
THE LAST HOUR OR TWO...ESPECIALLY NEAR AND SOUTH OF I-70. REPORTS OF
VIRGA DUE TO DRY AIR THROUGH THE BOUNDARY LAYER AND RADAR RETURNS
CURRENTLY SUPPORTING THIS. WITH 35-40KT JET NOTED ALOFT AT
850MB...THERE IS LIKELY SOME MIXING DOWN OF THE STRONGER WINDS AT
4-5KFT GOING ON AND CONTRIBUTING TO THE ENHANCEMENT IN WIND GUSTS.
HAVE THEREFORE BUMPED UP WIND GUSTS FOR THE DURATION OF THE
EVENING...ESPECIALLY NEAR AND SOUTH OF I-70. WINDS SHOULD DROP OFF
BY LATE EVENING AS LOW LEVEL JET SHIFTS EAST WITH SURFACE BOUNDARY.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
THERE IS QUITE A BIT OF DISAGREEMENT AMONG THE MODELS ON THE TRACK
OF THE SURFACE LOW THURSDAY INTO FRIDAY AND THIS WILL HAVE A BIG
IMPACT ON THE WEATHER THAT ENSUES. THE ECMWF TAKES THE LOW SOUTH OF
THE AREA WITH AGREEMENT FROM THE UKMET AND ECMWF ENSEMBLES...WHILE
THE GFS/NAM/ AND SREFS TAKE THE TRACK THROUGH ACROSS THE NORTHERN
PART OR JUST NORTH OF THE AREA. THE GEM SEEMED TO BE A SOLUTION IN
BETWEEN THOSE TWO CAMPS AND THUS TRENDED TOWARD IT.
A WARM FRONT SHOULD BE FORMING ACROSS OR JUST SOUTH OF THE AREA
THURSDAY MORNING AND THIS SHOULD PROVIDE FORCING FOR OVERRUNNING
RAIN SHOWERS WITH THE BEST CHANCES IN THE NORTHERN COUNTIES. AS THE
LOW PRESSURE MOVES ACROSS OR BY THE AREA THROUGH THE DAY IT COULD
DRAG A COLD FRONT THROUGH BY AROUND 0Z...AND WITH A 40 KT LOW LEVEL
JET FORMING UP SOUTH OF THE AREA IN THE AFTERNOON AND SOME ELEVATED
INSTABILITY AVAILABLE COULD SEE SOME THUNDERSTORMS FORM IN THE
AFTERNOON ESPECIALLY IN THE SOUTHERN COUNTIES. WHILE SPC GENERAL
THUNDER OUTLOOK ENCOMPASSES THE ENTIRE FORECAST AREA...THINK THAT
THE BEST CHANCES WILL REMAIN IN THE SOUTHERN COUNTIES WITH ONLY
ISOLATED THUNDER CENTRAL AND PROBABLY NO THUNDER IN THE NORTH. WHILE
AN ISOLATED SEVERE STORM IN THE SOUTH CANNOT BE RULED OUT...BEST
CHANCES FOR SEVERE SHOULD REMAIN SOUTH OF THE AREA.
BY THURSDAY NIGHT THE SYSTEM SHOULD BE MOVING OUT OF THE
AREA...ALTHOUGH SOME UPPER FORCING WILL REMAIN WEST OF THE AREA.
COLD AIR IS LAGGING BEHIND THE FRONT AND THUS WILL KEEP CHANCES FOR
RAIN ACROSS ALL BUT THE NORTHWEST WHERE SNOW COULD MIX IN BEFORE
6Z...AND EXPAND THE MIX ACROSS THE AREA FROM 6-12Z. COULD SEE SOME
STRONG WINDS IN THE WAKE OF THE LOW ON THURSDAY NIGHT AND FRIDAY
DEPENDING ON THE EXACT TRACK. FOR FRIDAY KEPT A CHANCE FOR RAIN OR
SNOW GOING FOR MOST OF THE AREA WITH RAIN CHANCE IN THE FAR SOUTH
BASED ON THE LITTLE FORCING LEFT FROM THE UPPER TROUGH...BUT NOT
ENOUGH TO GO BEYOND A SMALL CHANCE. THE SYSTEM WILL MOVE OUT ON
FRIDAY NIGHT LEAVING A CHANCE FOR SNOW IN THE NORTHEAST AS IT
EXITS...AND BY SATURDAY THE AREA SHOULD BE DRY.
FOR TEMPERATURES GENERALLY USED A CONSENSUS WITH A NUDGE TOWARD THE
GEM.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AN UPPER TROUGH MOVING ACROSS THE NORTHERN U.S. WILL AFFECT OUR
WEATHER AROUND MONDAY. HOWEVER MODELS HAVE TRENDED WITH LESS PRECIP
WITH THIS SYSTEM. I AM NOT CONFIDENT ENOUGH TO TAKE OUT CHANCE OF
PRECIP MONDAY...BUT WILL DROP MENTION ACROSS OUR SOUTHEAST HALF
SUNDAY NIGHT AND ALL AREAS MONDAY MONDAY NIGHT.
A SECOND AND POTENTIALLY MUCH STRONGER SYSTEM WILL AFFECT OUR
WEATHER BY THE MIDDLE OF NEXT WEEK. BOTH 12Z EURO AND 12Z GFS BRINGS
SIGNIFICANT PRECIP BY DAY 7. THERE IS A LOT OF DISAGREEMENT IN THE
SURFACE LOW TRACK AND ULTIMATELY PRECIP TYPE. AT THIS TIME MY
CONFIDENCE IS LOW...SO FOR NOW WILL RAISE ALL BLEND TEMPS TUESDAY
NIGHT AND LOWER THEM WEDNESDAY TO REDUCE THE DIURNAL RANGE. THIS
WOULD GIVE ME SNOW TUESDAY NIGHT WITH MIXED PRECIP SOUTH AND MOSTLY
RAIN WEDNESDAY. CONFIDENCE IS LOW ON PRECIP TYPE...BUT THIS MIDDLE
OF THE ROAD APPROACH SEEMS BEST WAY TO GO UNTIL MODELS HAVE A BETTER
AGREEMENT.
&&
.AVIATION /DISCUSSION FOR THE 230000Z TAFS/...
WEAK LOW PRESSURE MOVING ACROSS CENTRAL INDIANA WITH A MID CLOUD
DECK AND WILL CARRY SOME GUSTY WIND UNTIL ABOUT START OF TAF TIME.
RADAR SHOWING SOME LIGHT ECHOES BUT LITTLE IF ANY REACHING GROUND.
MAIN IMPACT IN THIS FORECAST PERIOD WILL BE SYSTEM COMING OUT OF
THE ROCKIES. FAIRLY DRY AIR IN PLACE...DESPITE MOISTENING SOME
WITH SCT SHRA THURSDAY...SHOULD STILL REMAIN VFR THROUGH THE
FORECAST THOUGH BRIEF PERIOD OF MVFR CIGS AND VSBY POSSIBLE
DURING PERIODS WHEN SHOWERS ARE HEAVIER.
MODELS STILL DIFFER ON DEVELOPING SURFACE LOW TRACK ACROSS EITHER
CENTRAL OR SOUTHERN INDIANA AFTER 231800Z. MAJORITY OF RAIN WILL
FALL ACROSS NORTHERN INDIANA THOUGH PERIODS OF SHOWERS ARE LIKELY
AT TAF SITES AFTER 231300Z...RANGING FROM SHORT LIVED AT KBMG TO
MUCH OF DAY AT KLAF NEARER DEEPEST MOISTURE.
FOR WINDS...AFTER GUSTS DIE DOWN EARLY THIS EVENING...AS SURFACE
LOW MOVES INTO IOWA AND MISSOURI BY 231200Z...SURFACE WINDS
GENERALLY BACK TO SE AROUND 10KTS TOWARD SUNRISE. SHOULD SURFACE LOW
TRACK ACROSS SOUTHERN INDIANA THEN SURFACE WINDS WILL BACK MORE TO
BECOME EASTERLY. RIGHT NOW THOUGHT IS SURFACE LOW WILL COME OVER
TAF SITES BRINGING ALL BUT KLAF WINDS AROUND TO SOUTH AND SW
231800Z- 2100Z TIME FRAME. KLAF WILL REMAIN FAR ENOUGH TO NORTH OF
THE LOW CENTER THAT WINDS SHOULD REMAIN SE OR BACK TO EAST BY
232100Z.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...RYAN
SHORT TERM...CP
LONG TERM....JH
AVIATION...TUCEK
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1117 AM EST TUE FEB 21 2012
.AVIATION.../18Z TAFS/.
SOMEWHAT IMPROVING CONDITIONS EXPECTED AT BOTH SITES WITH MVFR
CIGS TO SLOWLY DOMINATE INTO THIS AFTERNOON AS EFFECTS OF
WEAKENING WAVE LESSEN. KSBN MAY SEE A CHANCE FOR SOME LIGHT
SHOWERS INTO THIS AFTERNOON AS A WEAKENING AREA OF RAIN/SNOW MOVES
OUT OF ILLINOIS/WISCONSIN. HAVE LEFT VCSH IN TO COVER. SOME BREAKS
IN CLOUD COVER ALSO NOTED WHICH MAY IMPACT KSBN AND ALLOW FOR
BRIEF IMPROVEMENT IN CIGS.
SIGNS NOT PROMISING FOR CLEARING SKIES TONIGHT AS ADDITIONAL MSTR
STREAMS IN FROM THE NW ACROSS THE AREA. WILL MAINTAIN VFR
CIGS/VSBYS FOR NOW BUT UPSTREAM OBS SUGGEST RETURN TO MVFR WILL BE
POSSIBLE OVERNIGHT.
&&
.UPDATE...
WILL BE UPDATING ZONES AGAIN IN THE NEXT HALF HOUR TO HOUR AS
COMPACT VORT MAX FINALLY SLIDING ACROSS THE AREA AND WEAKENING.
RADAR TRENDS HAVE SHOWN PRECIP FALLING APART RAPIDLY OVER THE PAST
HOUR WITH THIS TREND EXPECTED TO CONTINUE. FEW BREAKS IN THE
CLOUDS OBSERVED BACK ACROSS ILLINOIS WITH RISING TEMPS IN AND
OUT OF CLOUD COVER. AS A RESULT ANY SNOW SHOULD BEGIN TO MELT BACK
OFF WITH IMPROVING ROAD CONDITIONS FOR THOSE AREAS THAT SEEN THE
QUICK SHOT OF SNOW THIS MORNING. LAST AREA OF LIGHT SNOW/RAIN WAS
SEEN MOVING ACROSS SOUTHERN WISCONSIN INTO NORTHERN ILLINOIS. THIS
HAS BEEN SHOWING SIGNS OF WEAKENING AS WELL. WILL BE GETTING RID
OF A LOT OF THE POPS INTO THIS AFTERNOON EXCEPT NORTHERN SECTIONS
WHERE ABOVE MENTIONED PRECIP MAY CLIP. HIGHS ON TRACK FOR THE TIME
BEING SO NO CHANGES.
.PREV DISCUSSION... /ISSUED 351 AM EST TUE FEB 21 2012...CORRECTION/
SHORT TERM... / TODAY THROUGH WEDNESDAY NIGHT /
POTENT NEGATIVELY TILTED SHORTWAVE OVER MISSOURI WILL TRACK QUICKLY
NEWD THROUGH THE NORTHERN OHIO VALLEY THIS MORNING...WEAKENING A BIT
AS IT BEGINS TO PHASE WITH A NORTHERN STREAM WAVE DROPPING INTO THE
UPPER MIDWEST. THIS MISSOURI NEGATIVE HEIGHT ANOMALY LOOKS
IMPRESSIVE ON WATER VAPOR THIS MORNING WITH A TROWAL CLEARLY
EVIDENT. HOWEVER QUICK MOVEMENT AND SLIGHT WEAKENING TREND WILL
RESULT IN A LIGHTER PCPN AMOUNTS LOCALLY...GENERALLY BTW
0.10-0.25". STILL EXPECTING ABOUT A 2-3 HOUR PERIOD OF ORGANIZED
PCPN...WHICH WILL BE TIED TO A NARROW PLUME OF DEEP MOIST ASCENT
ON THE NOSE OF A ~50 KT LLJ AS CPD`S RAPIDLY LOWER FROM NEAR 200
MB TO 0-5 MB ON THE 290K SFC. USED A MODEL BLEND (MORE WEIGHT TO
HIGH RES GUIDANCE) TO TIME HIGHER POPS THROUGH THE FA. VERY DRY
ANTECEDENT AIRMASS PER 00Z AREA RAOBS AND DYNAMIC NATURE TO SYSTEM
STILL DOES SUPPORT THE CHANCES FOR A RAIN/SNOW MIX NW OF HIGHWAY
24...WITH A BRIEF BURST OF SNOW POSSIBLY SUPPORTING SOME LIGHT
ACCUMS MAINLY ALONG/NORTH OF ROUTE 6 IN INDIANA AND MICHIGAN.
STEEPENING MID LVL LAPSE RATES AND STRONG DYNAMIC/EVAPORATIVE
COOLING SUPPORT THE GOING CHC FOR A BRIEF PERIOD OF WET
SNOW...ESPECIALLY GIVEN TRENDS OF LATEST 05Z HRRR AND 06Z NAM.
THE LOW LVL FLOW WILL VEER SOUTHWESTERLY BEHIND AN OCCLUDED FRONT...
ALLOWING THE LOWEST 3 KFT TO WARM WELL ABOVE FREEZING EVERYWHERE BY
LATE MORNING AND AFTERNOON. ALSO...A TIGHTENING PRESSURE GRADIENT
WILL SUPPORT A BREEZY AFTERNOON WITH GUSTS OF 20-30 MPH POSSIBLE
PER BUFR MOMENTUM TRANSFER PROGS. DEEPER MOISTURE/LIFT WILL EXIT
TO THE EAST LEAVING A LOW OVERCAST AND DRIER CONDITIONS IN ITS
WAKE. HOWEVER..LINGERING MOIST LOW LEVELS AND POSSIBLE WEAK LIFT
FROM A SECONDARY SHORTWAVE COULD STILL SPARK A FEW SHOWERS THIS
AFTERNOON INTO EARLY THIS EVENING.
A SERIES OF SHORTWAVES WILL EMERGE OUT OF A 140 KT PLUS NORTH
PACIFIC UPPER JET THAT WILL HAVE WORKED WELL INLAND INTO THE CENTRAL
PLAINS BY WEDNESDAY/WEDNESDAY NIGHT. THIS WILL SUPPORT MID LVL
TROUGHING INTO THE CENTRAL CONUS AND FAST WESTERLY FLOW ALOFT
LOCALLY. GIVEN NEGATIVE THETA-E ADV IN THE LOW LEVELS TONIGHT WOULD
EXPECT ANY SHORTWAVE ENERGY IN FAST FLOW TO HAVE TROUBLE GENERATING
ANY RAINFALL ON WEDNESDAY. THERE APPEARS TO BE A BETTER CHANCE FOR
MEASURABLE RAINFALL BY WEDNESDAY NIGHT AS A MID LEVEL BAROCLINIC
ZONE LOOKS TO TIGHTEN OVERHEAD.
LONG TERM...
HIGH ENERGY NEPAC WAVE TRAIN AND ASSOCD/INTENSE UPR JET YIELDING
EXTREME MODEL VARIABILITY W/TIME ONCE AGAIN THIS MORNING AND
ALREADY MANIFESTING ITSELF TO BEGIN THE PD ON DY3 THU. PSBL EPAC
RECON TOMORROW EVENING WILL LEAD TO MITIGATION OF THE UNCERTAINTY
LTR THIS WEEK.
REGARDLESS PRIOR GRID ALIGNMENT STILL HOLDS FOR DY3 GIVEN A CONTD
PREFERENCE/DEPENDENCE ON ECMWF W/CORRESPONDING NOD FM UKMET...BOTH
OF WHICH DIG ROBUST NRN STREAM SW SEEN IN VAPOR NR 48N/163W THIS
MORNING QUICKER AND FARTHER WEST WHILE GFS SYSTEMIC PROGRESSION
BIASES RENDER ITS SOLUTION SUSPECT. THIS HWVR DOES NECESSITATE CHGS
FRI AS MID LVL DEFORMATION ZONE IS MORE LIKELY TO HANG BACK IN
RESPONSE TO SIG ERN OH VALLEY CYCLOGENESIS AT LEAST THROUGH MORNING.
OTHERWISE CHGS BEYOND DY4 DEEMED FUTILE GIVEN RAMPANT MODEL SPREAD
AND UNCERTAINTY.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 11 AM EST WEDNESDAY FOR LMZ043-046.
&&
$$
SHORT TERM...STEINWEDEL
LONG TERM...T
AVIATION...FISHER
UPDATE...FISHER
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
752 AM EST TUE FEB 21 2012
.UPDATE...
QUICK UPDATE SENT TO INCREASE SNOW ACCUMULATIONS ALONG AND
NORTHEAST OF US 30 FOR THIS MORNING. LEADING EDGE OF STRONG
FORCING RAPIDLY EXPANDED AND INTENSIFIED WITH RETURNS GREATER THAN
35 DBZ SEEN. WHILE MOST LOCATIONS HAVE REMAINED AROUND 1 MILE VSBY
AND ONLY A DUSTING OF SNOW LOCATIONS UNDER THESE HIGHER RETURNS
HAVE SEEN SNOWFALL RATES OF AN INCH OR MORE PER HOUR AS DYNAMIC
COOLING HAS OFFSET APPROACHING INCREASING IN TEMPS FOR THE TIME
BEING. SFC TEMP AT THE OFFICE DROPPED 3.5 DEGREES IN ABOUT ONE
HALF HOUR WHILE UNDER THE HEAVIER BAND WITH LARGE SNOWFLAKE
PRODUCTION.
WELL PRONOUNCED CIRCULATION STILL SEEN IN WATER VAPOR LOOP TAKING
AIM ON THE AREA THIS MORNING. PRECIP MAY CONTINUE TO EXPAND BEHIND
THIS INITIAL BURST...BUT PTYPE STILL SOMEWHAT QUESTIONABLE WITH
INCREASE IN LL TEMPS STILL EXPECTED WITH ARRIVAL OF WAVE. WILL
MONITOR TRENDS OVER THE NEXT COUPLE OF HOURS FOR FURTHER UPDATES.
&&
.PREV DISCUSSION... /ISSUED 351 AM EST TUE FEB 21 2012...CORRECTION/
SHORT TERM... / TODAY THROUGH WEDNESDAY NIGHT /
POTENT NEGATIVELY TILTED SHORTWAVE OVER MISSOURI WILL TRACK QUICKLY
NEWD THROUGH THE NORTHERN OHIO VALLEY THIS MORNING...WEAKENING A BIT
AS IT BEGINS TO PHASE WITH A NORTHERN STREAM WAVE DROPPING INTO THE
UPPER MIDWEST. THIS MISSOURI NEGATIVE HEIGHT ANOMALY LOOKS
IMPRESSIVE ON WATER VAPOR THIS MORNING WITH A TROWAL CLEARLY
EVIDENT. HOWEVER QUICK MOVEMENT AND SLIGHT WEAKENING TREND WILL
RESULT IN A LIGHTER PCPN AMOUNTS LOCALLY...GENERALLY BTW
0.10-0.25". STILL EXPECTING ABOUT A 2-3 HOUR PERIOD OF ORGANIZED
PCPN...WHICH WILL BE TIED TO A NARROW PLUME OF DEEP MOIST ASCENT
ON THE NOSE OF A ~50 KT LLJ AS CPD`S RAPIDLY LOWER FROM NEAR 200
MB TO 0-5 MB ON THE 290K SFC. USED A MODEL BLEND (MORE WEIGHT TO
HIGH RES GUIDANCE) TO TIME HIGHER POPS THROUGH THE FA. VERY DRY
ANTECEDENT AIRMASS PER 00Z AREA RAOBS AND DYNAMIC NATURE TO SYSTEM
STILL DOES SUPPORT THE CHANCES FOR A RAIN/SNOW MIX NW OF HIGHWAY
24...WITH A BRIEF BURST OF SNOW POSSIBLY SUPPORTING SOME LIGHT
ACCUMS MAINLY ALONG/NORTH OF ROUTE 6 IN INDIANA AND MICHIGAN.
STEEPENING MID LVL LAPSE RATES AND STRONG DYNAMIC/EVAPORATIVE
COOLING SUPPORT THE GOING CHC FOR A BRIEF PERIOD OF WET
SNOW...ESPECIALLY GIVEN TRENDS OF LATEST 05Z HRRR AND 06Z NAM.
THE LOW LVL FLOW WILL VEER SOUTHWESTERLY BEHIND AN OCCLUDED FRONT...
ALLOWING THE LOWEST 3 KFT TO WARM WELL ABOVE FREEZING EVERYWHERE BY
LATE MORNING AND AFTERNOON. ALSO...A TIGHTENING PRESSURE GRADIENT
WILL SUPPORT A BREEZY AFTERNOON WITH GUSTS OF 20-30 MPH POSSIBLE
PER BUFR MOMENTUM TRANSFER PROGS. DEEPER MOISTURE/LIFT WILL EXIT
TO THE EAST LEAVING A LOW OVERCAST AND DRIER CONDITIONS IN ITS
WAKE. HOWEVER..LINGERING MOIST LOW LEVELS AND POSSIBLE WEAK LIFT
FROM A SECONDARY SHORTWAVE COULD STILL SPARK A FEW SHOWERS THIS
AFTERNOON INTO EARLY THIS EVENING.
A SERIES OF SHORTWAVES WILL EMERGE OUT OF A 140 KT PLUS NORTH
PACIFIC UPPER JET THAT WILL HAVE WORKED WELL INLAND INTO THE CENTRAL
PLAINS BY WEDNESDAY/WEDNESDAY NIGHT. THIS WILL SUPPORT MID LVL
TROUGHING INTO THE CENTRAL CONUS AND FAST WESTERLY FLOW ALOFT
LOCALLY. GIVEN NEGATIVE THETA-E ADV IN THE LOW LEVELS TONIGHT WOULD
EXPECT ANY SHORTWAVE ENERGY IN FAST FLOW TO HAVE TROUBLE GENERATING
ANY RAINFALL ON WEDNESDAY. THERE APPEARS TO BE A BETTER CHANCE FOR
MEASURABLE RAINFALL BY WEDNESDAY NIGHT AS A MID LEVEL BAROCLINIC
ZONE LOOKS TO TIGHTEN OVERHEAD.
LONG TERM...
HIGH ENERGY NEPAC WAVE TRAIN AND ASSOCD/INTENSE UPR JET YIELDING
EXTREME MODEL VARIABILITY W/TIME ONCE AGAIN THIS MORNING AND
ALREADY MANIFESTING ITSELF TO BEGIN THE PD ON DY3 THU. PSBL EPAC
RECON TOMORROW EVENING WILL LEAD TO MITIGATION OF THE UNCERTAINTY
LTR THIS WEEK.
REGARDLESS PRIOR GRID ALIGNMENT STILL HOLDS FOR DY3 GIVEN A CONTD
PREFERENCE/DEPENDENCE ON ECMWF W/CORRESPONDING NOD FM UKMET...BOTH
OF WHICH DIG ROBUST NRN STREAM SW SEEN IN VAPOR NR 48N/163W THIS
MORNING QUICKER AND FARTHER WEST WHILE GFS SYSTEMIC PROGRESSION
BIASES RENDER ITS SOLUTION SUSPECT. THIS HWVR DOES NECESSITATE CHGS
FRI AS MID LVL DEFORMATION ZONE IS MORE LIKELY TO HANG BACK IN
RESPONSE TO SIG ERN OH VALLEY CYCLOGENESIS AT LEAST THROUGH MORNING.
OTHERWISE CHGS BEYOND DY4 DEEMED FUTILE GIVEN RAMPANT MODEL SPREAD
AND UNCERTAINTY.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 11 AM EST
WEDNESDAY FOR LMZ043-046.
&&
$$
SHORT TERM...STEINWEDEL
LONG TERM...T
UPDATE...FISHER
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
351 AM EST TUE FEB 21 2012...CORRECTION
.SHORT TERM... / TODAY THROUGH WEDNESDAY NIGHT /
POTENT NEGATIVELY TILTED SHORTWAVE OVER MISSOURI WILL TRACK QUICKLY
NEWD THROUGH THE NORTHERN OHIO VALLEY THIS MORNING...WEAKENING A BIT
AS IT BEGINS TO PHASE WITH A NORTHERN STREAM WAVE DROPPING INTO THE
UPPER MIDWEST. THIS MISSOURI NEGATIVE HEIGHT ANOMALY LOOKS
IMPRESSIVE ON WATER VAPOR THIS MORNING WITH A TROWAL CLEARLY
EVIDENT. HOWEVER QUICK MOVEMENT AND SLIGHT WEAKENING TREND WILL
RESULT IN A LIGHTER PCPN AMOUNTS LOCALLY...GENERALLY BTW
0.10-0.25". STILL EXPECTING ABOUT A 2-3 HOUR PERIOD OF ORGANIZED
PCPN...WHICH WILL BE TIED TO A NARROW PLUME OF DEEP MOIST ASCENT
ON THE NOSE OF A ~50 KT LLJ AS CPD`S RAPIDLY LOWER FROM NEAR 200
MB TO 0-5 MB ON THE 290K SFC. USED A MODEL BLEND (MORE WEIGHT TO
HIGH RES GUIDANCE) TO TIME HIGHER POPS THROUGH THE FA. VERY DRY
ANTECEDENT AIRMASS PER 00Z AREA RAOBS AND DYNAMIC NATURE TO SYSTEM
STILL DOES SUPPORT THE CHANCES FOR A RAIN/SNOW MIX NW OF HIGHWAY
24...WITH A BRIEF BURST OF SNOW POSSIBLY SUPPORTING SOME LIGHT
ACCUMS MAINLY ALONG/NORTH OF ROUTE 6 IN INDIANA AND MICHIGAN.
STEEPENING MID LVL LAPSE RATES AND STRONG DYNAMIC/EVAPORATIVE
COOLING SUPPORT THE GOING CHC FOR A BRIEF PERIOD OF WET
SNOW...ESPECIALLY GIVEN TRENDS OF LATEST 05Z HRRR AND 06Z NAM.
THE LOW LVL FLOW WILL VEER SOUTHWESTERLY BEHIND AN OCCLUDED FRONT...
ALLOWING THE LOWEST 3 KFT TO WARM WELL ABOVE FREEZING EVERYWHERE BY
LATE MORNING AND AFTERNOON. ALSO...A TIGHTENING PRESSURE GRADIENT
WILL SUPPORT A BREEZY AFTERNOON WITH GUSTS OF 20-30 MPH POSSIBLE
PER BUFR MOMENTUM TRANSFER PROGS. DEEPER MOISTURE/LIFT WILL EXIT
TO THE EAST LEAVING A LOW OVERCAST AND DRIER CONDITIONS IN ITS
WAKE. HOWEVER..LINGERING MOIST LOW LEVELS AND POSSIBLE WEAK LIFT
FROM A SECONDARY SHORTWAVE COULD STILL SPARK A FEW SHOWERS THIS
AFTERNOON INTO EARLY THIS EVENING.
A SERIES OF SHORTWAVES WILL EMERGE OUT OF A 140 KT PLUS NORTH
PACIFIC UPPER JET THAT WILL HAVE WORKED WELL INLAND INTO THE CENTRAL
PLAINS BY WEDNESDAY/WEDNESDAY NIGHT. THIS WILL SUPPORT MID LVL
TROUGHING INTO THE CENTRAL CONUS AND FAST WESTERLY FLOW ALOFT
LOCALLY. GIVEN NEGATIVE THETA-E ADV IN THE LOW LEVELS TONIGHT WOULD
EXPECT ANY SHORTWAVE ENERGY IN FAST FLOW TO HAVE TROUBLE GENERATING
ANY RAINFALL ON WEDNESDAY. THERE APPEARS TO BE A BETTER CHANCE FOR
MEASURABLE RAINFALL BY WEDNESDAY NIGHT AS A MID LEVEL BAROCLINIC
ZONE LOOKS TO TIGHTEN OVERHEAD.
&&
.LONG TERM...
HIGH ENERGY NEPAC WAVE TRAIN AND ASSOCD/INTENSE UPR JET YIELDING
EXTREME MODEL VARIABILITY W/TIME ONCE AGAIN THIS MORNING AND
ALREADY MANIFESTING ITSELF TO BEGIN THE PD ON DY3 THU. PSBL EPAC
RECON TOMORROW EVENING WILL LEAD TO MITIGATION OF THE UNCERTAINTY
LTR THIS WEEK.
REGARDLESS PRIOR GRID ALIGNMENT STILL HOLDS FOR DY3 GIVEN A CONTD
PREFERENCE/DEPENDENCE ON ECMWF W/CORRESPONDING NOD FM UKMET...BOTH
OF WHICH DIG ROBUST NRN STREAM SW SEEN IN VAPOR NR 48N/163W THIS
MORNING QUICKER AND FARTHER WEST WHILE GFS SYSTEMIC PROGRESSION
BIASES RENDER ITS SOLUTION SUSPECT. THIS HWVR DOES NECESSITATE CHGS
FRI AS MID LVL DEFORMATION ZONE IS MORE LIKELY TO HANG BACK IN
RESPONSE TO SIG ERN OH VALLEY CYCLOGENESIS AT LEAST THROUGH MORNING.
OTHERWISE CHGS BEYOND DY4 DEEMED FUTILE GIVEN RAMPANT MODEL SPREAD
AND UNCERTAINTY.
&&
.AVIATION... / 06Z TAFS /
POTENT NEGATIVE HEIGHT ANOMALY NEAR THE KS/MO BORDER WILL LIFT
NEWD THROUGH THE AREA LATER THIS MORNING. NARROW PLUME OF DEEP
MOIST ASCENT ON NOSE OF THE LOW LEVEL JET AND ASSOCIATED OCCLUDING
WARM FRONT WILL BRING ABOUT RAPIDLY DETERIORATING FLIGHT CONDITIONS
BTW 12-15Z...ALONG WITH A 2-3 HOUR PERIOD OF ORGANIZED LIGHT TO
MODERATE PCPN. EVAPORATIVE/DYNAMIC COOLING ON LEADING EDGE COULD
LEAD TO A BRIEF PERIOD OF IFR/LIFR SNOW AT THE START...BETTER
CHANCES AT SBN. AFTER THAT EXPECT A FEW SHOWERS/DRIZZLE WITH TOP
DOWN SATURATION YIELDING IFR OR LOW END MVFR CEILINGS MID MORNING
INTO MUCH OF THE AFTERNOON. OTHERWISE...WINDS WILL VEER
SOUTHWESTERLY BEHIND THE AFOREMENTIONED OCCLUDED FRONT WITH GUSTS
OF 20-30 KNOTS EXPECTED.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...STEINWEDEL
LONG TERM...T
AVIATION...STEINWEDEL
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
351 AM EST TUE FEB 21 2012
.SHORT TERM... / TODAY THROUGH WEDNESDAY NIGHT /
POTENT NEGATIVELY TILTED SHORTWAVE OVER MISSOURI WILL TRACK QUICKLY
NEWD THROUGH THE NORTHERN OHIO VALLEY THIS MORNING...WEAKENING A BIT
AS IT BEGINS TO PHASE WITH A NORTHERN STREAM WAVE DROPPING INTO THE
UPPER MIDWEST. THIS MISSOURI NEGATIVE HEIGHT ANOMALY LOOKS
IMPRESSIVE ON WATER VAPOR THIS MORNING WITH A TROWAL CLEARLY
EVIDENT. HOWEVER QUICK MOVEMENT AND SLIGHT WEAKENING TREND WILL
RESULT IN A LIGHTER PCPN AMOUNTS LOCALLY...GENERALLY BTW
0.10-0.25". STILL EXPECTING ABOUT A 2-3 HOUR PERIOD OF ORGANIZED
PCPN...WHICH WILL BE TIED TO A NARROW PLUME OF DEEP MOIST ASCENT
ON THE NOSE OF A ~50 KT LLJ AS CPD`S RAPIDLY LOWER FROM NEAR 200
MB TO 0-5 MB ON THE 290K SFC. USED A MODEL BLEND (MORE WEIGHT TO
HIGH RES GUIDANCE) TO TIME HIGHER POPS THROUGH THE FA. VERY DRY
ANTECEDENT AIRMASS PER 00Z AREA RAOBS AND DYNAMIC NATURE TO SYSTEM
STILL DOES SUPPORT THE CHANCES FOR A RAIN/SNOW MIX NW OF HIGHWAY
24...WITH A BRIEF BURST OF SNOW POSSIBLY SUPPORTING SOME LIGHT
ACCUMS MAINLY ALONG/NORTH OF ROUTE 6 IN INDIANA AND MICHIGAN.
STEEPENING MID LVL LAPSE RATES AND STRONG DYNAMIC/EVAPORATIVE
COOLING SUPPORT THE GOING CHC FOR A BRIEF PERIOD OF WET
SNOW...ESPECIALLY GIVEN TRENDS OF LATEST 05Z HRRR AND 06Z NAM.
THE LOW LVL FLOW WILL VEER SOUTHWESTERLY BEHIND AN OCCLUDED FRONT...
ALLOWING THE LOWEST 3 KFT TO WARM WELL ABOVE FREEZING EVERYWHERE BY
LATE MORNING AND AFTERNOON. ALSO...A TIGHTENING PRESSURE GRADIENT
WILL SUPPORT A BREEZY AFTERNOON WITH GUSTS OF 20-30 MPH POSSIBLE
PER BUFR MOMENTUM TRANSFER PROGS. DEEPER MOISTURE/LIFT WILL EXIT
TO THE EAST LEAVING A LOW OVERCAST AND DRIER CONDITIONS IN ITS
WAKE. HOWEVER..LINGERING MOIST LOW LEVELS AND POSSIBLE WEAK LIFT
FROM A SECONDARY SHORTWAVE COULD STILL SPARK A FEW SHOWERS THIS
AFTERNOON INTO EARLY THIS EVENING.
A SERIES OF SHORTWAVES WILL EMERGE OUT OF THE 140 KT PLUS NORTH
PACIFIC UPPER JET THAT WILL HAVE WORKED WELL INLAND INTO THE CENTRAL
PLAINS BY WEDNESDAY/WEDNESDAY NIGHT. THIS WILL SUPPORT MID LVL
TROUGHING INTO THE CENTRAL CONUS AND FAST WESTERLY FLOW ALOFT
LOCALLY. GIVEN NEGATIVE THETA-E ADV IN THE LOW LEVELS TONIGHT
WOULD EXPECT ANY SHORTWAVE ENERGY IN FAST FLOW TO HAVE TROUBLE
GENERATING ANY RAINFALL ON WEDNESDAY. THERE APPEARS TO BE A BETTER
CHANCE FOR MEASURABLE RAINFALL BY WEDNESDAY NIGHT AS A MID LEVEL
BAROCLINIC ZONE LOOKS TO TIGHTEN OVERHEAD.
&&
.LONG TERM...
HIGH ENERGY NEPAC WAVE TRAIN AND ASSOCD/INTENSE UPR JET YIELDING
EXTREME MODEL VARIABILITY W/TIME ONCE AGAIN THIS MORNING AND
ALREADY MANIFESTING ITSELF TO BEGIN THE PD ON DY3 THU. PSBL EPAC
RECON TOMORROW EVENING WILL LEAD TO MITIGATION OF THE UNCERTAINTY
LTR THIS WEEK.
REGARDLESS PRIOR GRID ALIGNMENT STILL HOLDS FOR DY3 GIVEN A CONTD
PREFERENCE/DEPENDENCE ON ECMWF W/CORRESPONDING NOD FM UKMET...BOTH
OF WHICH DIG ROBUST NRN STREAM SW SEEN IN VAPOR NR 48N/163W THIS
MORNING QUICKER AND FARTHER WEST WHILE GFS SYSTEMIC PROGRESSION
BIASES RENDER ITS SOLUTION SUSPECT. THIS HWVR DOES NECESSITATE CHGS
FRI AS MID LVL DEFORMATION ZONE IS MORE LIKELY TO HANG BACK IN
RESPONSE TO SIG ERN OH VALLEY CYCLOGENESIS AT LEAST THROUGH MORNING.
OTHERWISE CHGS BEYOND DY4 DEEMED FUTILE GIVEN RAMPANT MODEL SPREAD
AND UNCERTAINTY.
&&
.AVIATION... / 06Z TAFS /
POTENT NEGATIVE HEIGHT ANOMALY NEAR THE KS/MO BORDER WILL LIFT
NEWD THROUGH THE AREA LATER THIS MORNING. NARROW PLUME OF DEEP
MOIST ASCENT ON NOSE OF THE LOW LEVEL JET AND ASSOCIATED OCCLUDING
WARM FRONT WILL BRING ABOUT RAPIDLY DETERIORATING FLIGHT CONDITIONS
BTW 12-15Z...ALONG WITH A 2-3 HOUR PERIOD OF ORGANIZED LIGHT TO
MODERATE PCPN. EVAPORATIVE/DYNAMIC COOLING ON LEADING EDGE COULD
LEAD TO A BRIEF PERIOD OF IFR/LIFR SNOW AT THE START...BETTER
CHANCES AT SBN. AFTER THAT EXPECT A FEW SHOWERS/DRIZZLE WITH TOP
DOWN SATURATION YIELDING IFR OR LOW END MVFR CEILINGS MID MORNING
INTO MUCH OF THE AFTERNOON. OTHERWISE...WINDS WILL VEER
SOUTHWESTERLY BEHIND THE AFOREMENTIONED OCCLUDED FRONT WITH GUSTS
OF 20-30 KNOTS EXPECTED.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...STEINWEDEL
LONG TERM...T
AVIATION...STEINWEDEL
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1226 AM EST TUE FEB 21 2012
.AVIATION... / 06Z TAFS /
POTENT NEGATIVE HEIGHT ANOMALY NEAR THE KS/MO BORDER WILL LIFT
NEWD THROUGH THE AREA LATER THIS MORNING. NARROW PLUME OF DEEP
MOIST ASCENT ON NOSE OF THE LOW LEVEL JET AND ASSOCIATED OCCLUDING
WARM FRONT WILL BRING ABOUT RAPIDLY DETERIORATING FLIGHT CONDITIONS
BTW 12-15Z...ALONG WITH A 2-3 HOUR PERIOD OF ORGANIZED LIGHT TO
MODERATE PCPN. EVAPORATIVE/DYNAMIC COOLING ON LEADING EDGE COULD
LEAD TO A BRIEF PERIOD OF IFR/LIFR SNOW AT THE START...BETTER
CHANCES AT SBN. AFTER THAT EXPECT A FEW SHOWERS/DRIZZLE WITH TOP
DOWN SATURATION YIELDING IFR OR LOW END MVFR CEILINGS MID MORNING
INTO MUCH OF THE AFTERNOON. OTHERWISE...WINDS WILL VEER
SOUTHWESTERLY BEHIND THE AFOREMENTIONED OCCLUDED FRONT WITH GUSTS
OF 20-30 KNOTS EXPECTED.
&&
.PREV DISCUSSION... /ISSUED 823 PM EST MON FEB 20 2012/
UPDATE...
DELAYED ONSET OF PRECIPITATION PER SLOWER SOLUTION FROM BOTH 18Z NAM
AND LATEST HRRR GUIDANCE. ISENTROPIC PRECIP SHIELD WILL EXPAND
ACROSS THE AREA FROM WEST TO EAST DURING THE EARLY MORNING HOURS
AS MOISTURE PROFILE IMPROVES. INITIAL EVAPORATIVE COOLING COUPLED
WITH DYNAMIC LIFT SHOULD COOL THE COLUMN ENOUGH TO ALLOW FOR A RAIN
SNOW MIX THROUGH THE MORNING HOURS. ALSO ADJUSTED THE RAIN/SNOW
LINE SLIGHTLY NORTHWARD TO ACCOUNT FOR SLIGHTLY WARMER SOLUTION
TUE MORNING AS THE SHORTWAVE CURRENTLY OVER KANSAS PER WV IMAGERY
GOES NEGATIVE TILT AND ATTEMPTS TO PHASE WITH THE NORTHERN STREAM
TROUGH DURING THE MORNING HOURS TUE.
ADJUSTED NEAR TERM TEMPS DOWNWARD TO ACCOUNT FOR MOST RECENT
OBSERVATIONS AND TREND IN LATEST HRRR.
SHORT TERM...
FOCUS IN SHORT TERM CENTERS ON APPROACHING SHORT WAVE TROUGH AND
PRECIPITATION TYPE LATE TONIGHT AND TUESDAY MORNING. 12Z GUIDANCE IN
GOOD AGREEMENT AND LITTLE CHANGE FROM PRIOR RUNS. POTENT SHORT WAVE
CURRENTLY ACROSS CENTRAL PLAINS WILL LIFT NORTHEAST TONIGHT AND TAKE
ON A NEGATIVE TILT AS IT MOVES THROUGH THE GREAT LAKES. THIS WILL
RESULT IN BRIEF BUT INTENSE LIFT ACROSS THE AREA AS LOW LEVEL JET
ADVECTS INTO AREA. ISENTROPIC SURFACES BECOME SATURATED TOWARD 12Z
WITH STRONG LIFT DEPICTED AS WELL.
THERMAL PROFILES CONTINUE TO BE BORDERLINE FOR RAIN AND SNOW WITH
SNOW POSSIBLE AT ONSET GIVEN EVAPORATIVE COOLING PROCESSES WITH VERY
DRY AIRMASS INITIALLY. ONCE SATURATED..STRONG DYNAMIC LIFT MAY BE
ABLE TO KEEP PCPN AS SNOW OR AT LEAST MIXED. PREVIOUS FORECAST HAS
THIS HANDLED WELL WITH EXCELLENT DETAIL IN GRIDS. GIVEN LITTLE
CHANGE IN 12Z RUNS SEE NO REASON TO DEVIATE MUCH FROM PRIOR WEATHER
GRIDS OTHER THAN A FEW MINOR TWEAKS.
SOME SNOW ACCUMULATIONS REMAIN POSSIBLE...ESPECIALLY WEST AND NORTH
BUT TOTALLY DEPENDENT ON STRONG LIFT COOLING COLUMN ENOUGH TO GO
OVER TO ALL SNOW. THIS SYSTEM WILL BE CONVECTIVE IN NATURE AND THIS
ALREADY BEING SEEN UPSTREAM WHERE SOME LIGHTNING HAS BEEN NOTED OVER
EASTERN KS EARLY THIS AFTERNOON. THIS WOULD AID IN CHANGEOVER TO
SNOW. WILL KEEP ACCUMS IN THE ONE INCH OR LESS RANGE WITH THIS
PACKAGE BUT CERTAINLY WILL BE LOOKED AT CLOSELY THIS EVENING AND
OVERNIGHT PRIOR TO ONSET.
LINGERING PCPN EXPECTED ON TUESDAY. SECONDARY WEAKER SHORT WAVE
MOVES THROUGH TUE NIGHT WITH NAM SHOWING SOME LIGHT PCPN WITH IT.
HAVE ADDED A SLIGHT CHANCE POP FOR THIS FEATURE THOUGH IT COULD END
UP ONLY PRODUCING DRIZZLE OR SPRINKLE/FLURRY. FEW CHANGES NEEDED TO
TEMPS.
LONG TERM.../WEDNESDAY THROUGH MONDAY/
ACTIVE PATTERN IN STORE FOR THE EXTENDED PERIOD WITH SEVERAL CHANCES
FOR RAIN/SNOW.
TROUGH WILL BE EXITING THE REGION AT THE START OF THE
PERIOD...LEAVING BEHIND CLEARING SKIES AND A RETURN TO ABOVE NORMAL
TEMPS WITH COLD AIR BEING SHUNTED NORTH. WARM FRONT WILL SETUP TO
THE SOUTH AND MAKE A RUN FOR THE AREA WEDS NGT INTO THURS. MODELS
VARY ON HANDLING OF THIS FEATURE RANGING FROM STALLING OUT ACROSS
THE AREA TO PUSHING WELL NORTH. CHANCE FOR RAIN EXISTS ALONG AND
AHEAD OF THIS BOUNDARY BUT HAVE BEEN HELD IN CHC RANGE GIVEN MODEL
DIFFERENCES. GULF MSTR WILL REMAIN CUT OFF AT THIS POINT BUT NAM12
12Z RUN BRINGS A DECENT WAVE ALONG THE FRONT WITH A TENTH TO QUARTER
INCH OR MORE OF PRECIP THURS AFTERNOON/EVE. FOR SAME REASONS AS
POPS...HAVE KEPT TEMPS IN CHECK ON THURSDAY FOR THE TIME BEING WITH
PROXIMITY OF WARM FRONT AND SERIES OF WEAK DISTURBANCES LIKELY TO
WRECK HAVOC WITH AFTERNOON HIGHS. IF FRONT CAN SURGE NORTH AND SKIES
CLEAR...READINGS WELL INTO THE 50S WILL BE IN STORE.
LONGWAVE TROUGH WILL STRENGTHEN TO THE WEST WITH NORTHERN AND
SOUTHERN STREAM ENERGY MOVING TOWARDS THE AREA THURS NGT INTO FRI.
GFS KEEPS MAIN SFC LOW FURTHER NORTH WITH DEEPENING OF LOW INTO NEW
ENGLAND BY FRI MORNING. ECMWF KEEPS SOUTHERN STREAM SYSTEM STRONGEST
WITH INTENSIFICATION AND POTENTIAL FOR WRAP AROUND/TROWAL PRECIP
INTO THE AREA THURS NGT INTO FRI. HAVE HELD SHY OF LIKELY POPS GIVEN
ABUNDANCE OF SCENARIOS THAT MAY UNFOLD.
COLDER AIR WILL ARRIVE IN THE WAKE OF THE SYSTEM WITH CHANCES FOR
LAKE EFFECT SNOW SHOWERS STILL ON TAP FRI INTO SAT. HAVE KEPT WITH
GENERAL IDEA OF PREV FORECAST. YET ANOTHER WAVE MOVES IN TOWARDS THE
END OF THE PERIOD WITH CHANCE FOR RAIN ARRIVING ONCE AGAIN.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...LASHLEY
LONG TERM...FISHER
UPDATE...BENTLEY
AVIATION...STEINWEDEL
AREA FORECAST DISCUSSION
NWS TOPEKA KS
459 PM CST TUE FEB 21 2012
...AVIATION UPDATE...
.DISCUSSION...
SEE PREV DISCUSSION.
&&
.AVIATION...
THE NAM AND RUC FORECAST SOUNDINGS ARE INDICATING A STEEP NOCTURNAL
INVERSION SETTING UP LATE TONIGHT. SO THERE IS A CONCERN FOR SOME
LOW LEVEL WIND SHEER. WILL WATCH AND SEE HOW THE 00Z MODELS COME IN.
OTHERWISE DRY AIR IN THE LOWEST COUPLE KILOMETERS WILL LEAD TO VFR
CONDITIONS.
WOLTERS
&&
.PREV DISCUSSION... /334 PM CST TUE FEB 21 2012/
WESTERLY FLOW IN THE MID LEVELS WILL CONTINUE THROUGH THE PERIOD. A
SHORTWAVE WILL DROP SOUTHWEST OUT OF THE PACIFIC NORTHWEST LATE
TONIGHT WITH INCREASE IN MID LEVEL MOISTURE SO EXPECT A MID CLOUD
DECK TO MOVE OVER AFTER MIDNIGHT THEN EXIT DURING THE MORNING HOURS
ON TUESDAY. AS ANOTHER WAVE MOVES ACROSS THE NORTHERN PLAINS ON
TUESDAY MORE CLOUDS WILL MOVE INTO THE FAR NORTHERN COUNTIES IN THE
AFTERNOON NEAR THE NEBRASKA BORDER.
TONIGHT THE WINDS WILL DROP OFF AFTER SUNSET AS THE WINDS DECOUPLE
IN THE BOUNDARY LAYER. THIS WILL ALLOW TEMPERATURES TO COOL INTO THE
LOW TO MID 30S.
ON TUESDAY...THE COMBINATION OF WESTERLY DOWNSLOPE FLOW...ABUNDANT
SUNSHINE AND MIXING DOWN FROM 800 MB WILL YIELD HIGHS IN THE LOW TO
MID 60S FOR MUCH OF THE AREA. WEST WINDS WILL GUST OVER 20 MPH IN
THE AFTERNOON.
53
NEXT SHORTWAVE TROUGH MOVING ACROSS THE NORTHERN PLAINS WEDNESDAY
NIGHT/THURSDAY WILL FOCUS PRECIP TO THE NORTH OF THE AREA WITH
STILL A DRY FCST FOR THIS PERIOD. HOWEVER...AFTER WESTERLY WINDS
MOST OF THE NIGHT...A FRONT WILL BEGIN TO TRAVERSE THE CWA LATE IN
THE NIGHT. THE TIMING OF THE FRONT WILL LIKELY BE TOO LATE TO HAVE
A LOT OF IMPACT ON LOW TEMPS...EXCEPT MAYBE THE FAR NORTH WHERE A
FEW READINGS IN THE MIDDLE 30S ARE EXPECTED. ELSEWHERE...TEMPS
EXPECTED TO REMAIN WELL ABOVE NORMAL WITH LOWS SOUTH OF I 70
GENERALLY 40 TO 43 DEGREES. THE AFFECTS OF THE COLDER AIR MOVING
INTO THE CWA BEHIND THE FRONT WILL BE FELT MORE DURING THE DAY
THURSDAY AS HIGH TEMPS TOP OUT IN THE UPPER 40S AND LOWER 50S...OR
ABOUT 10 TO 15 DEGREES COOLER THAN WEDNESDAY ALONG WITH A BLUSTERY
NORTHWEST.
THE COOLEST HIGHS STILL LOOK TO BE ON FRIDAY WHERE THE COOLER LOWS
IN THE 20S TO AROUND 30 WILL HELP TO LIMIT THE DAYTIME HIGHS TO THE
40S. THE UPPER LEVEL PATTERN INTO THE WEEKEND STILL SHOWS THE UPPER
LEVEL SHORTWAVE TROUGH OVER THE GREAT LAKES MOVING OFF THE EAST
COAST WITH ANOTHER STRONG UPPER TROUGH ADVANCING FROM THE PACIFIC
NORTHWEST AND INTO THE NORTHERN PLAINS BY SUNDAY. WARM AIR ADVECTION
AHEAD OF THIS SYSTEM OVER THE WEEKEND SHOULD PUSH HIGHS INTO THE
LOWER 50S IN MANY AREAS BEFORE THE NORTHERN PLAINS WAVE PUSHES
ANOTHER COLD FRONT ACROSS THE CWA SUNDAY NIGHT. THIS WILL PROVIDE
THE NEXT CHANCE FOR RAIN OR POSSIBLY SOME SNOW SUNDAY NIGHT AS THE
COLDER AIR OVERSPREADS THE AREA BEHIND THE FRONT.
THERE MAY THEN BE A BRIEF BREAK IN PRECIP CHANCES DURING THE DAY ON
MONDAY BEFORE ANOTHER SYSTEM APPROACHES THE CENTRAL PLAINS FROM THE
ROCKIES LATER MONDAY NIGHT INTO TUESDAY. IF THIS SCENARIO
HAPPENS...MORE COLD AIR WOULD ALREADY BE IN PLACE AHEAD OF IT AND
THEREFORE SNOW CHANCES WOULD BE A LITTLE HIGHER. IT IS DIFFICULT
THIS FAR OUT IN THIS PATTERN TO GO WITH AN ALL SNOW FORECAST FOR AN
EXTENDED PERIOD OF TIME. WILL GO WITH A LIGHT SNOW/RAIN SNOW MIX
MONDAY NIGHT AND TUESDAY FOR NOW WITH HIGHS TUESDAY IN THE 30S. 63
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1150 PM CST MON FEB 20 2012
.AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
LOW CLOUDS WILL CONTINUE TO PUSH EAST AND SHOULD CLEAR KSLN/KICT
AT THE ONSET...AND KCNU BEFORE DAYBREAK. APPEARS SOME CIRRUS WILL
SPILL INTO THE AREA AROUND DAYBREAK AS WELL. GUSTY WINDS SHOULD
GRADUALLY DIMINISH OVERNIGHT. VFR CONDITIONS ARE EXPECTED AT ALL
SITES ON TUE WITH WINDS GRADUALLY DIMINISHING. -HOWERTON
&&
.PREV DISCUSSION... /ISSUED 616 PM CST MON FEB 20 2012/
AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
FRONT WILL CONTINUE TO PUSH EAST WITH STORMS MOVING THROUGH KCNU AT
THE ONSET. SOME LIGHT RAIN AND/OR SNOW SHOWERS WILL BE POSSIBLE THIS
EVENING IN THE WRAP AROUND MOISTURE...MAINLY IN THE VICINITY OF
KRSL...ALTHOUGH NOT OUT OF THE QUESTION AT KSLN/KHUT. KICT IS
LIKELY A BIT FAR REMOVED FROM THE BETTER MOISTURE FOR PRECIPITATION.
RAPID CLEARING IS ANTICIPATED ONCE WAVE MOVES THROUGH. VERY GUSTY WINDS
ARE LIKELY BOTH AHEAD/BEHIND FRONT...WITH WINDS ONLY GRADUALLY
DIMINISHING OVERNIGHT AND DURING THE DAY ON TUESDAY. -HOWERTON
PREV DISCUSSION... /ISSUED 211 PM CST MON FEB 20 2012/
DISCUSSION...
FORECAST CONCERNS...CONVECTIVE TRENDS THRU EARLY EVENING AND
THEN TEMPERATURE ROLLER-COASTER THRU THE END OF THE WEEK.
THIS EVENING/OVERNIGHT
LATEST RUC AND HRRR WOULD SUGGEST 700-900 J/KG CAPE NEAR MAX
HEATING LATE THIS AFTERNOON JUST AHEAD OF SURFACE DRY-LINE/COLD
FRONT ACROSS SOUTH CENTRAL KANSAS. THIS IN COMBO WITH STRONG
DEEP LAYER SHEAR WILL SUPPORT STRONG TO A FEW SEVERE STORMS
INTO THE EARLY EVENING TRANSITIONING FROM PORTIONS OF CENTRAL
AND SOUTH CENTRAL KANSAS ACROSS THE SOUTHERN FLINT HILLS. SEE
LATEST HAZARDOUS WEATHER OUTLOOK AND SHORT TERM GRAPHICAST FOR
MORE DETAILS.
OTHERWISE...WINDS SHOULD REMAIN STOUT EVEN BEHIND THE FRONT
THIS EVENING...NEAR ADVISORY THRESHOLDS...SO 06Z/MIDNIGHT
EXPIRATION LOOKS FINE.
TUESDAY-FRIDAY
A RATHER SIGNIFICANT WARMING TREND IS EXPECTED THROUGH THE
MID-WEEK PERIOD WITHIN THE DEVELOPING MEAN WESTERLY FLOW
AHEAD OF THE NEXT UPPER TROF. THIS SUPPORTS THE GOING MAXS...
APPROACHING 70F IN MANY AREAS ON WEDNESDAY. THIS WILL BE
FOLLOWED BY A MODERATE STRENGTH COLD FRONT ON THURSDAY WITH
TEMPERATURES CLOSER TO SEASONAL CLIMO FOR THE END OF THE WEEK.
SATURDAY-MONDAY
A MORE ZONAL UPPER FLOW PATTERN TO START OUT THE WEEKEND
WITH TEMPERATURES AGAIN MODERATING ABOVE SEASONAL CLIMO. THE
MEDIUM RANGE MODELS GENERALLY SUPPORT MEAN TROUGHING ALOFT
ACROSS THE WESTERN CONUS LATE IN THE PERIOD...WITH THE ECMWF
A BIT DEEPER WITH THIS TROF BY MONDAY. THE MAIN CHALLENGE IS
THE TIMING OF THE ASSOCIATED COLD FRONTAL BOUNDARY SOUTH
ACROSS THE PLAINS...AND POTENTIAL OF SIGNIFICANT COOLING
BEHIND THIS FRONT. FOR NOW FORECAST CONSENSUS WAS TO TREND
COOLER BY MONDAY...THOUGH CONFIDENCE IS RATHER LOW ON THE
MAGNITUDE...WITH POTENTIAL FOR MUCH COLDER AIR. WILL ALSO
CARRY SLIGHT TO MODEST POPS ALONG/JUST BEHIND THIS SOUTHWARD
SAGGING FRONT FOR NOW WHICH CAN BE REFINED WITH LATER RUNS.
DARMOFAL
AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
MVFR CIGS WILL HANG TOUGH THROUGH AT LEAST MID-
AFTERNOON...ALTHOUGH SOME CLEARING FROM THE WEST IS EXPECTED AS A
STRONG COLD FRONT CONTINUES TO APPROACH FROM THE WEST. AHEAD OF
THE FRONT...VERY STRONG/GUSTY SOUTHERLY WINDS WILL PREVAIL.
ADDITIONALLY...SCATTERED THUNDERSTORMS SHOULD DEVELOP AROUND
20-21Z JUST WEST OF THE I-135 CORRIDOR. STORM MOTION WILL BE TO
THE NORTHEAST AT 50-60 MPH. A FEW STORMS WILL LIKELY PRODUCE SMALL
TO MODERATE SIZE HAIL UP TO DIME/QUARTER SIZE...ALONG WITH GUSTY
WINDS. THE STORMS WILL MOVE RAPIDLY NORTHEAST...WITH VERY STRONG
WEST/NORTHWEST WINDS DEVELOPING BY EARLY THIS EVENING BEHIND THE
COLD FRONT SWEEPING EAST ACROSS THE AREA...ALONG WITH MVFR TO LOW
VFR CIGS. CIGS AND WINDS WILL DISSIPATE BY LATE EVENING FROM WEST
TO EAST...CLEARING KCNU LAST.
KLEINSASSER
FIRE WEATHER...
STRONG WINDS WILL CONTINUE TO ELEVATE FIRE DANGER THROUGH THE
EVENING ACROSS MUCH OF THE AREA. DRIER AIR AND DIURNALLY GUSTY
WINDS MAY LEAD TO PERIODS OF ELEVATED FIRE DANGER DURING THE
AFTERNOON HOURS FROM TUESDAY THROUGH THURSDAY.
KED
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 28 57 33 68 / 20 0 0 0
HUTCHINSON 27 57 32 69 / 20 0 0 0
NEWTON 29 56 34 68 / 30 0 0 0
ELDORADO 30 56 34 67 / 30 0 0 0
WINFIELD-KWLD 29 58 33 69 / 20 0 0 0
RUSSELL 26 56 32 69 / 40 0 0 0
GREAT BEND 26 56 32 69 / 30 0 0 0
SALINA 28 57 33 69 / 50 0 0 0
MCPHERSON 28 57 33 68 / 30 0 0 0
COFFEYVILLE 33 59 34 69 / 80 0 0 0
CHANUTE 32 57 34 67 / 80 0 0 0
IOLA 32 56 34 66 / 80 0 0 0
PARSONS-KPPF 33 58 34 68 / 80 0 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1119 PM CST MON FEB 20 2012
...UPDATE FOR AVIATION...
.UPDATE...
ISSUED AT 933 PM CST MON FEB 20 2012
WINDS CONTINUE TO DECREASE ACROSS NORTH CENTRAL KANSAS THIS
EVENING. GIVEN THE TRENDS FROM THE WINDS AT HAYS, GREAT BEND, AND
PRATT WILL ALLOW THE WIND ADVISORY EXPIRE AT 10 PM.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 235 PM CST MON FEB 20 2012
FORECAST CONCERNS ARE THE SNOW AND HIGH WINDS LATE THIS AFTERNOON
INTO EARLY EVENING. THIS MORNINGS UA ANALYSIS SHOWED A STRONG
UPPER TROUGH ALONG THE EASTERN SLOPES OF THE ROCKIES WITH A CLOSED
CIRCULATION SHOWING UP OVER NORTHEAST COLORADO. THIS FEATURE HAS BEEN
MOVING STEADILY EAST THROUGH WESTERN KANSAS AND THE OK/TX PANHANDLES
THIS AFTERNOON. RUC ANALYSIS SHOWED A FAIRLY INTENSE MID LEVEL
VORT MAX ACROSS THE AREA WITH STRONG PVA AND MID LEVEL UVV OCCURRING
OVER SOUTHWEST KANSAS. THIS LINES UP WELL WITH AN AREA OF LIGHT
TO MODERATE SNOW WHICH HAS BEEN TRANSLATING EAST THROUGH SOUTHWEST
KANSAS TODAY.
THE AREAS OF RAIN AND SNOW SHOULD CONTINUE TO WORK EASTWARD ACROSS
SOUTHWEST AND TOWARD CENTRAL KANSAS THROUGH THE LATE AFTERNOON
HOURS BUT SHOULD BEGIN TO DIMINISH RAPIDLY TOWARD SUNSET AS THE
TROUGH AXIS MOVES EAST OF THE AREA.
HIGH WINDS HAVE BEEN SLOW TO MATERIALIZE ACROSS SOUTHWEST KANSAS
THIS AFTERNOON PARTLY DUE TO THE WIDESPREAD CLOUD COVER AND
REDUCED MIXING. AM STILL CONCERNED THAT WE COULD SEE A WINDOW OF
OPPORTUNITY AS THE GRADIENT INCREASES ON THE BACKSIDE OF THE LOWER
ATMOSPHERIC TROUGH AXIS. RUC MODEL SOUNDINGS THROUGHOUT THE DAY
HAVE BEEN SHOWING 50-60 KNOT WINDS DEVELOPING IN THE 850-875 MB
LAYER THROUGH THE 21Z-01Z TIME PERIOD. WILL KEEP THE CURRENT
HEADLINES IN PLACE THROUGH THE EARLY EVENING HOURS.
THE UPPER LEVEL SHORTWAVE TROUGH WILL MOVE RAPIDLY EAST OUT OF THE
PLAINS TONIGHT WITH WESTERLY FLOW OVER THE HIGH PLAINS. ANOTHER
BROAD SHORTWAVE TROUGH IS FORECAST TO MOVE SOUTHEAST OVER THE
CENTRAL CONUS DURING THE DAY TUESDAY. ONLY SOME SCATTERED HIGH
CLOUDINESS IS EXPECTED WITH THE SHORTWAVE. LOW LEVEL DOWNSLOPE
FLOW SHOULD HELP BOOST TEMPERATURES INTO THE 55 TO 60 DEGREE RANGE
FOR AFTERNOON HIGHS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 543 PM CST MON FEB 20 2012
NORTHWESTERLY MID TO HIGH LEVEL FLOW WILL DEVELOP BY TUESDAY NIGHT
AND PERSIST THROUGH FRIDAY. THIS IS USUALLY A DRY REGIME FOR
WESTERN KANSAS AS THE GULF OF MEXICO TENDS TO BE SHUT OFF.
DOWNSLOPE WESTERLY LOW-LEVEL FLOW WILL DEVELOP TUESDAY NIGHT WITH
850MB TEMPERATURES RISING TO BETWEEN 6 AND 9C. HOWEVER, GIVEN THE
EXPECTED CLEAR SKIES AND ONLY 5 TO 10 KT WINDS, TEMPERATURES WILL
PROBABLY STILL DROP INTO THE LOWER 30S. WEDNESDAY WILL BE A WARM DAY
WITH WESTERLY DOWNSLOPE FLOW PERSISTING AS SURFACE LOW PRESSURE DEVELOPS
ACROSS NEBRASKA AHEAD OF A SHORTWAVE TROUGH. IN THESE SITUATIONS IN
LATE WINTER AND EARLY SPRING TEMPERATURES TYPICALLY GET WARMER THAN
ANY OF THE MODELS INDICATE. GIVEN THE EXPECTED WESTERLY SURFACE
WINDS AT 10 TO 20 KTS, A DEEP, DRY ADIABATIC LAYER WILL DEVELOP.
TEMPERATURES OUGHT TO EASILY REACH INTO THE UPPER 60S TO LOWER 70S.
AS IS TYPICAL IN DOWNSLOPE REGIMES WHEN THE WEST WINDS PROGRESS ALL
THE WAY INTO CENTRAL KANSAS, THE VERY WARMEST READINGS MAY BE ON THE
LOWER TERRAIN OF SOUTHERN CLARK, COMANCHE AND BARBER COUNTIES
(ELEVATIONS 1500-2000FT) AS OPPOSED TO DODGE CITY (2600FT), GARDEN
CITY (2900FT) AND SYRACUSE (3300FT).
COOL SURFACE HIGH PRESSURE WILL MOVE INTO WESTERN KANSAS LATE
WEDNESDAY NIGHT AND THURSDAY IN THE WAKE OF THE AFOREMENTIONED
SHORTWAVE TROUGH. LOW TEMPERATURES WEDNESDAY NIGHT WILL BE TRICKY.
IT COULD ACTUALLY GET COLDER AHEAD OF THE FRONT IF WINDS CAN DROP OFF
TO LIGHT AND VARIABLE. VERTICAL MIXING IMMEDIATELY BEHIND THE FRONT
MAY KEEP LOCATIONS NEAR INTERSTATE 70 WARMER. BUT THIS IS SUBJECT
TO CHANGES IN FRONTAL TIMING. IN THE ABSENCE OF ARCTIC AIR, HIGH
TEMPERATURES SHOULD COOL DOWN TO NEAR SEASONAL VALUES, WITH HIGHS IN
THE UPPER 40S TO LOWER 50S THURSDAY AND UPPER 40S TO MID 50S FOR
FRIDAY.
BY SATURDAY AND SUNDAY, THE MODELS INDICATE UPPER-LEVEL TROUGHING
DEVELOPING ACROSS THE WESTERN UNITED STATES, THE SPEED AND AMPLITUDE
OF WHICH IS DIFFERENT DEPENDING ON THE MODEL. THIS SYSTEM WILL BRING
SOME ARCTIC AIR SOUTHWARD INTO THE NORTHERN OR EVEN CENTRAL PLAINS BY
SUNDAY. HOW FAST THIS ARCTIC FRONT MOVES THROUGH KANSAS IS
UNCERTAIN. BUT IT LOOKS LIKE TEMPERATURES WILL BE GETTING MUCH
COLDER SOMETIME BETWEEN SUNDAY AND TUESDAY (FEBRUARY 26-28TH). BUT
THERE WILL BE A VERY SHARP TEMPERATURE GRADIENT ALONG THE LEADING
EDGE OF THE ARCTIC AIR. SO SOME PLACES IN THE SOUTHERN PLAINS
(POSSIBLY INCLUDING SOUTHERN KANSAS) COULD GET VERY WARM SUNDAY OR
MONDAY (POSSIBLY 70S) BEFORE THE ARCTIC AIR ARRIVES. IT IS TOO EARLY
TO TELL IF ANY PRECIPITATION WILL ACCOMPANY THIS SYSTEM. AT THIS
POINT IT APPEARS THAT MOST OF THE PRECIPITATION WILL BE IN THE WARM
SECTOR AND WELL EAST OF HERE. HOWEVER, IF THE SYSTEM IS SLOWER AND
FURTHER SOUTH THAN WE CURRENTLY EXPECT, THEN SOME RAIN/SNOW WOULD BE
POSSIBLE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1112 PM CST MON FEB 20 2012
A DRY UPPER LEVEL SHORTWAVE TROUGH WILL MOVE ACROSS WESTERN KANSAS
TODAY AND TONIGHT WITH ONLY A FEW MID AND HIGH LEVEL CLOUDS. EXPECT
VFR CONDITIONS WITH LIGHT NORTHWESTERLY TO WESTERLY WINDS. THE
WINDS COULD PICK UP TO 15 TO 25 KTS BY 15-18Z TUESDAY AT KYHS BUT
RAPIDLY DROP BY SUNSET.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 22 58 30 71 / 90 0 0 0
GCK 20 56 28 70 / 0 0 0 0
EHA 21 57 33 70 / 0 0 0 0
LBL 21 58 30 72 / 0 0 0 0
HYS 25 56 30 69 / 0 0 0 0
P28 27 60 32 73 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BURGERT
SHORT TERM...GERARD
LONG TERM....FINCH
AVIATION...KRUSE
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1248 PM EST TUE FEB 21 2012
.SYNOPSIS...
AN EASTBOUND OCCLUDED FRONT WILL PROVIDE SHOWERS AND GUSTY WINDS
THIS AFTERNOON, KEEPING TEMPERATURES MILD INTO THURSDAY. A STRONGER COLD
FRONT PASSES FRIDAY, USHERING IN COLD WEATHER FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOOKS LIKE VARIABLE MARCH WEATHER HAS ARRIVED EARLY.
PER RECENT SURFACE AND RADAR DATA, THE FRONTAL BAND OF RAIN
SHOWERS HAS BEEN LEADING OFF WITH A SHORT PERIOD OF LIGHT SNOW
SHOWERS, DESPITE TEMPERATURES OVER 40 DEGREES. THIS IS DUE TO
EVAPORATIONAL COOLING EFFECTS WITHIN THE INITIALLY DRY SURFACE
LAYER. NATURAL GRASSY SURFACES CAN BE COLDER THAN 32, SO A FEW
FLAKES CAN ACCUMULATE THERE, BUT PAVEMENTS BEING TREATED WILL JUST
BECOME WET.
MORE NOTEWORTHY IS THAT SURFACE WINDS CAN GUST UP TO 35 TO 40 MPH
IN THE WAKE OF THESE SHOWERS, PER BLEND OF RECENT SURFACE DATA AND
NAM MODEL PROFILES.
TEMPERATURE DETAILS WERE BASED ON BLEND OF RECENT HRRR, NAM, AND
GFS LAMP OUTPUT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
RAIN CHANCES SHOULD DECREASE AS A SHORT WAVE TROUGH EXITS TO THE
NORTHEAST TONIGHT, BUT A SURFACE BOUNDARY STRETCHED ACROSS THE
FORECAST AREA WILL MAINTAIN AT LEAST A CHANCE OF SHOWERS WEDNESDAY
INTO WEDNESDAY NIGHT.
MODELS SHOW A SURFACE LOW TRACKING EAST ACROSS THE GREAT LAKES
WITH A WARM FRONT PUSHING THROUGH THE UPPER OHIO VALLEY THURSDAY.
RAIN CHANCES WILL INCREASE AND TEMPERATURES SHOULD WARM INTO THE
50S TO LOWER 60S IN THE WARM SECTOR.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
VERY LITTLE CONFIDENCE IN THE LONG TERM AS MODEL DIFFERENCES MAKE
IT DIFFICULT TO PIN DOWN A CONSISTENT FORECAST.
STRONG FRONT WILL PASS THROUGH ON FRIDAY, BUT STILL DISCREPANCIES
ON TIMING AND IF SFC WAVE WILL DEVELOP ALONG THE FRONT.
MUCH COLDER AIR FOR THE WEEKEND. WITH LES POSSIBLE SATURDAY INTO
EARLY SUNDAY.
DIFFERENCES IN SOLUTIONS CONTINUE INTO THE BEGINNING OF NEXT WEEK.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
PER RECENT SURFACE AND HRRR MODEL OUTPUT, EXPECT A FRONTAL BAND OF
MAINLY MVFR SHOWERS TO COMPLETE ITS EASTWARD PINWHEEL THROUGH THE
UPPER OHIO VALLEY BY LATE AFTERNOON. EVAPORATIONAL COOLING WITHIN THE
INITIALLY DRY SURFACE LAYER CAN CAUSE UP TO 1 HOUR OF PURE SNOW
SHOWERS AT THE START WITH IFR VISIBILITIES, MAINLY AT KFKL AND
KDUJ AND POSSIBLY KLBE.
WINDS CAN GUST TO 35 KTS IN THE WAKE OF THE SHOWERS. THE SHOWERS
SHOULD EXIT EAST INTO THE MOUNTAINS BY 22Z.
NAM MODEL PROFILES SHOW WIND GUSTS SUBSIDING TO 20-25 KTS AFTER
01Z. CONSENSUS OF NAM AND GFS LAMP/MOS SHOW STRATOCUMULUS CEILINGS
CAN REMAIN AT MVFR LEVELS INTO DAYTIME WEDNESDAY. SHOWERS
ASSOCIATED WITH ANOTHER FRONTAL PASSAGE COULD MAINTAIN MVFR
CONDITIONS THROUGH THE AFTERNOON.
OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY...
RESTRICTIONS POSSIBLE WITH RAIN SHOWERS WEDNESDAY NIGHT AND
THURSDAY. A MORE PROLONGED PERIOD OF RESTRICTIONS POSSIBLE FRIDAY
INTO SATURDAY DUE TO A STRONG COLD FRONTAL PASSAGE FRIDAY,
PROVIDING RAIN SHOWERS DAYTIME FRIDAY, FOLLOWED BY COLD POOL LOW
CLOUDS AND SCATTERED SNOW SHOWERS FRIDAY NIGHT INTO SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1127 AM EST TUE FEB 21 2012
.SYNOPSIS...
AN EASTBOUND OCCLUDED FRONT WILL PROVIDE SHOWERS AND GUSTY WINDS
THIS AFTERNOON, KEEPING TEMPERATURES MILD INTO THURSDAY. A STRONGER COLD
FRONT PASSES FRIDAY, USHERING IN COLD WEATHER FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOOKS LIKE VARIABLE MARCH WEATHER HAS ARRIVED EARLY.
PER RECENT SURFACE AND RADAR DATA, THE FRONTAL BAND OF RAIN
SHOWERS HAS BEEN LEADING OFF WITH A SHORT PERIOD OF LIGHT SNOW
SHOWERS, DESPITE TEMPERATURES OVER 40 DEGREES. THIS IS DUE TO
EVAPORATIONAL COOLING EFFECTS WITHIN THE INITIALLY DRY SURFACE
LAYER. NATURAL GRASSY SURFACES CAN BE COLDER THAN 32, SO A FEW
FLAKES CAN ACCUMULATE THERE, BUT PAVEMENTS BEING TREATED WILL JUST
BECOME WET.
MORE NOTEWORTHY IS THAT SURFACE WINDS CAN GUST UP TO 35 TO 40 MPH
IN THE WAKE OF THESE SHOWERS, PER BLEND OF RECENT SURFACE DATA AND
NAM MODEL PROFILES.
TEMPERATURE DETAILS WERE BASED ON BLEND OF RECENT HRRR, NAM, AND
GFS LAMP OUTPUT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
RAIN CHANCES SHOULD DECREASE AS A SHORT WAVE TROUGH EXITS TO THE
NORTHEAST TONIGHT, BUT A SURFACE BOUNDARY STRETCHED ACROSS THE
FORECAST AREA WILL MAINTAIN AT LEAST A CHANCE OF SHOWERS WEDNESDAY
INTO WEDNESDAY NIGHT.
MODELS SHOW A SURFACE LOW TRACKING EAST ACROSS THE GREAT LAKES
WITH A WARM FRONT PUSHING THROUGH THE UPPER OHIO VALLEY THURSDAY.
RAIN CHANCES WILL INCREASE AND TEMPERATURES SHOULD WARM INTO THE
50S TO LOWER 60S IN THE WARM SECTOR.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
VERY LITTLE CONFIDENCE IN THE LONG TERM AS MODEL DIFFERENCES MAKE
IT DIFFICULT TO PIN DOWN A CONSISTENT FORECAST.
STRONG FRONT WILL PASS THROUGH ON FRIDAY, BUT STILL DISCREPANCIES
ON TIMING AND IF SFC WAVE WILL DEVELOP ALONG THE FRONT.
MUCH COLDER AIR FOR THE WEEKEND. WITH LES POSSIBLE SATURDAY INTO
EARLY SUNDAY.
DIFFERENCES IN SOLUTIONS CONTINUE INTO THE BEGINNING OF NEXT WEEK.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
PER RECENT SURFACE AND HRRR MODEL OUTPUT, EXPECT A FRONTAL BAND OF
MAINLY MVFR SHOWERS TO PINWHEEL EASTWARD THROUGH THE UPPER OHIO
VALLEY TODAY. EVAPORATIONAL COOLING WITHIN THE INITIALLY DRY
SURFACE LAYER CAN CAUSE UP TO 1 HOUR OF SNOW SHOWERS AT THE START
WITH IFR VISIBILITIES POSSIBLE.
WINDS CAN GUST TO 35 KTS IN THE WAKE OF THE SHOWERS. THE SHOWERS
SHOULD EXIT EAST INTO THE MOUNTAINS BY 22Z.
OUTLOOK...TONIGHT THROUGH SATURDAY...
VFR TONIGHT WITH SUBSIDING WIND. RESTRICTIONS POSSIBLE WITH FRONTAL
BANDS OF RAIN SHOWERS WEDNESDAY AND THURSDAY. A MORE PROLONGED
PERIOD OF RESTRICTIONS POSSIBLE FRIDAY INTO SATURDAY DUE TO A
STRONG COLD FRONTAL PASSAGE FRIDAY, WITH RAIN SHOWERS FRIDAY,
FOLLOWED BY COLD POOL LOW CLOUDS AND SCATTERED SNOW SHOWERS FRIDAY
NIGHT INTO SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1022 AM EST TUE FEB 21 2012
.SYNOPSIS...
AN EASTBOUND OCCLUDED FRONT WILL PROVIDE SHOWERS AND GUSTY WINDS
TODAY, KEEPING TEMPERATURES MILD INTO THURSDAY. A STRONGER COLD
FRONT PASSES FRIDAY, USHERING IN COLD WEATHER FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
PER RECENT SURFACE AND RADAR DATA, COUPLED WITH RECENT HRRR AND
NAM MODEL OUTPUT, EXPECT A FRONTAL BAND OF SHOWERS TO QUICKLY
PINWHEEL EASTWARD THROUGH THE UPPER OHIO VALLEY THROUGH THE
AFTERNOON. DUE TO INITIAL DRYNESS OF THE SURFACE LAYER, THERE CAN
BE SUFFICIENT EVAPORATIONAL COOLING FOR A SHORT PERIOD OF SNOW
SHOWERS AT THE START, BUT THERE WILL NOT BE ANY ACCUMULATION.
MORE NOTEWORTHY IS THAT SURFACE WINDS CAN GUST UP TO 35 TO 40 MPH
IN THE WAKE OF THESE SHOWERS.
TEMPERATURE DETAILS WERE BASED ON BLEND OF RECENT HRRR, NAM, AND
GFS LAMP OUTPUT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
RAIN CHANCES SHOULD DECREASE AS A SHORT WAVE TROUGH EXITS TO THE
NORTHEAST TONIGHT, BUT A SURFACE BOUNDARY STRETCHED ACROSS THE
FORECAST AREA WILL MAINTAIN AT LEAST A CHANCE OF SHOWERS WEDNESDAY
INTO WEDNESDAY NIGHT.
MODELS SHOW A SURFACE LOW TRACKING EAST ACROSS THE GREAT LAKES
WITH A WARM FRONT PUSHING THROUGH THE UPPER OHIO VALLEY THURSDAY.
RAIN CHANCES WILL INCREASE AND TEMPERATURES SHOULD WARM INTO THE
50S TO LOWER 60S IN THE WARM SECTOR.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
VERY LITTLE CONFIDENCE IN THE LONG TERM AS MODEL DIFFERENCES MAKE
IT DIFFICULT TO PIN DOWN A CONSISTENT FORECAST.
STRONG FRONT WILL PASS THROUGH ON FRIDAY, BUT STILL DISCREPANCIES
ON TIMING AND IF SFC WAVE WILL DEVELOP ALONG THE FRONT.
MUCH COLDER AIR FOR THE WEEKEND. WITH LES POSSIBLE SATURDAY INTO
EARLY SUNDAY.
DIFFERENCES IN SOLUTIONS CONTINUE INTO THE BEGINNING OF NEXT WEEK.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
PER RECENT SURFACE AND HRRR MODEL OUTPUT, EXPECT A FRONTAL BAND OF
MVFR SHOWERS TO PINWHEEL EASTWARD THROUGH THE UPPER OHIO VALLEY
TODAY. FOR KZZV, THERE CAN BE UP TO 1 HOUR PERIOD OF IFR WITH SNOW
SHOWERS DUE TO EVAPORATIONAL COOLING WITHIN INITIALLY DRY SURFACE
LAYER. WINDS CAN GUST TO 35 KTS IN THE WAKE OF THE SHOWERS. THE SHOWERS
WILL HAVE PASSED EAST OF KZZV BY 16Z, AND AFFECT TAF SITES KFKL,
KPIT AND KMGW 16Z-19Z, AND KLBE AND KDUJ 17Z-20Z.
OUTLOOK...TONIGHT THROUGH SATURDAY...
VFR TONIGHT WITH SUBSIDING WIND. RESTRICTIONS POSSIBLE WITH FRONTAL
BANDS OF RAIN SHOWERS WEDNESDAY AND THURSDAY. A MORE PROLONGED
PERIOD OF RESTRICTIONS POSSIBLE FRIDAY INTO SATURDAY DUE TO A
STRONG COLD FRONTAL PASSAGE FRIDAY, WITH RAIN SHOWERS FRIDAY,
FOLLOWED BY COLD POOL LOW CLOUDS AND SCATTERED SNOW SHOWERS FRIDAY
NIGHT INTO SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
845 AM EST TUE FEB 21 2012
.SYNOPSIS...
AN EASTBOUND OCCLUDED FRONT WILL PROVIDE SHOWERS AND GUSTY WINDS
TODAY, KEEPING TEMPERATURES MILD INTO THURSDAY. A STRONGER COLD
FRONT PASSES FRIDAY, USHERING IN COLD WEATHER FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
PER RECENT SURFACE AND RADAR DATA, COUPLED WITH RECENT HRRR AND
NAM MODEL OUTPUT, EXPECT A FRONTAL BAND OF SHOWERS TO QUICKLY
PINWHEEL EASTWARD THROUGH THE UPPER OHIO VALLEY TODAY. DUE TO
INITIAL DRYNESS OF THE SURFACE LAYER, ITS POSSIBLE THERE MAY BE
SUFFICIENT EVAPORATIONAL COOLING FOR A FEW SNOW FLAKES AT THE
START, BUT THERE WILL NOT BE ANY ACCUMULATION. MORE NOTEWORTHY IS
THAT SURFACE WINDS CAN GUST UP TO 35 TO 40 MPH IN THE WAKE OF
THESE SHOWERS.
TEMPERATURE DETAILS WERE BASED ON BLEND OF RECENT HRRR, NAM, AND
GFS LAMP OUTPUT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
RAIN CHANCES SHOULD DECREASE AS A SHORT WAVE TROUGH EXITS TO THE
NORTHEAST TONIGHT, BUT A SURFACE BOUNDARY STRETCHED ACROSS THE
FORECAST AREA WILL MAINTAIN AT LEAST A CHANCE OF SHOWERS WEDNESDAY
INTO WEDNESDAY NIGHT.
MODELS SHOW A SURFACE LOW TRACKING EAST ACROSS THE GREAT LAKES
WITH A WARM FRONT PUSHING THROUGH THE UPPER OHIO VALLEY THURSDAY.
RAIN CHANCES WILL INCREASE AND TEMPERATURES SHOULD WARM INTO THE
50S TO LOWER 60S IN THE WARM SECTOR.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
VERY LITTLE CONFIDENCE IN THE LONG TERM AS MODEL DIFFERENCES MAKE
IT DIFFICULT TO PIN DOWN A CONSISTENT FORECAST.
STRONG FRONT WILL PASS THROUGH ON FRIDAY, BUT STILL DISCREPANCIES
ON TIMING AND IF SFC WAVE WILL DEVELOP ALONG THE FRONT.
MUCH COLDER AIR FOR THE WEEKEND. WITH LES POSSIBLE SATURDAY INTO
EARLY SUNDAY.
DIFFERENCES IN SOLUTIONS CONTINUE INTO THE BEGINNING OF NEXT WEEK.
&&
.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
PER RECENT SURFACE AND HRRR MODEL OUTPUT, EXPECT A FRONTAL BAND OF
MVFR SHOWERS TO PINWHEEL EASTWARD THROUGH THE UPPER OHIO VALLEY
TODAY. WINDS CAN GUST TO 35 KTS IN THEIR WAKE. THE SHOWERS WILL
HAVE PASSED EAST OF KZZV BY 15Z, AND AFFECT TAF SITES KFKL, KPIT
AND KMGW 15Z-19Z, AND KLBE AND KDUJ 16Z-20Z.
OUTLOOK...TONIGHT THROUGH SATURDAY...
VFR TONIGHT WITH SUBSIDING WIND. RESTRICTIONS POSSIBLE WITH FRONTAL
BANDS OF RAIN SHOWERS WEDNESDAY AND THURSDAY. A MORE PROLONGED
PERIOD OF RESTRICTIONS POSSIBLE FRIDAY INTO SATURDAY DUE TO A
STRONG COLD FRONTAL PASSAGE FRIDAY, WITH RAIN SHOWERS FRIDAY,
FOLLOWED BY COLD POOL LOW CLOUDS AND SCATTERED SNOW SHOWERS FRIDAY
NIGHT INTO SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1049 PM EST WED FEB 22 2012
.UPDATE...
ISSUED AT 1047 PM EST WED FEB 22 2012
HAVE UPDATED FORECASTS TO REFLECT LESS SNOWFALL ACCUMULATION OVERNIGHT.
PRECIPITATION HAS SPREAD INTO SW LOWER MI AND RECENTLY CHANGED
OVER TO SNOW. WE ARE EXPECTING SLIGHTLY LESS TOTAL SNOWFALL THAN
BEFORE...AS THE BACK EDGE OF THIS PRECIPITATION ALREADY IS
SWEEPING ACROSS SW LOWER MI.
WE ARE WATCHING FOG DEVELOP JUST SOUTH OF I-94. A CLOUD LAYER
ASSOCIATED WITH THE PRECIPITATION SHOULD REDUCE THE FOG IN THE
NEXT FEW HOURS. AFTERWARDS WE MAY SEE SOME FOG REDEVELOP TOWARDS
SUNRISE...BUT NOTHING DENSE IS EXPECTED AT THIS TIME.
UPDATE ISSUED AT 650 PM EST WED FEB 22 2012
MADE TIMING ADJUSTMENTS TO PRECIPITATION CHANCES THROUGH 2 AM.
PRECIPITATION TYPE IS EXPECTED TO BE RAIN INITIALLY AS IT NOW IS
IN WI...THANKS TO CURRENT SURFACE TEMPERATURES AND DEWPOINTS OVER
MUCH OF LOWER MI. A GRADUAL CHANGEOVER TO SNOW SHOULD OCCUR MAINLY
AFTER 10 PM.
HRRR SHORT RANGE GUIDANCE CONTINUES TO SUPPORT A NARROW BAND OF
SNOW CROSSING THE I-96 CORRIDOR TONIGHT...AND THIS IS SUPPORTED BY
THE 22/12Z NCEP NESTED ARW/NMM NAM. IMPACTS ARE EXPECTED TO BE
MINIMAL GIVEN TIMING AND EXPECTED INTENSITY.
UPDATE ISSUED AT 444 PM EST WED FEB 22 2012
WILL BE ISSUING A WINTER STORM WATCH SHORTLY FOR THE CWA FROM
THURSDAY AFTERNOON INTO FRIDAY MORNING BASED LARGELY ON LATEST
ECMWF GUIDANCE. WILL TRY TO HAVE THE WATCH OUT BY 5 PM.
&&
.SYNOPSIS...
ISSUED AT 1045 PM EST WED FEB 22 2012
AFTER MOSTLY LIGHT PRECIPITATION MOVES THROUGH THE AREA OVERNIGHT...HIGH
PRESSURE WILL BRING CLEARING CONDITIONS TO THE AREA THURSDAY
MORNING. A STORM DEVELOPING IN THE SOUTHERN PLAINS WILL APPROACH
THE AREA DURING THE DAY THURSDAY...BRINGING A PERIOD OF
SIGNIFICANT SNOWFALL TO THE AREA THURSDAY NIGHT. SOME LAKE EFFECT
SNOW IS EXPECTED INTO SATURDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 400 PM EST WED FEB 22 2012
THERE IS THE THREAT FOR A SIGNIFICANT SNOWFALL EVENT THURSDAY
NIGHT INTO FRIDAY. CURRENT THINKING IS 4 TO 7 INCHES OVER THE
CENTRAL CWA... NEAR INTERSTATE 96. MOST OF THE SNOW SHOULD FALL
DURING THE MID TO LATE EVENING HOURS OF THURSDAY NIGHT INTO THE
MID MORNING HOURS OF FRIDAY.
THERE IS ALSO THE THREAT FOR A BRIEF BURST OF SIGNIFICANT SNOW THIS
EVENING AS A SHORTWAVE OVER WISCONSIN HEADS EAST ACROSS LAKE
MICHIGAN AND INTENSIFIES THIS EVENING. BOTH THE HRRR SUGGESTS UP
TO .25 INCHES OF QPF IN 3 HOURS OVER PARTS OF NORTHERN OTTAWA AND
CENTRAL AND NORTHERN KENT COUNTIES BY BETWEEN 9 PM AND MIDNIGHT.
SINCE THE PRECIPITATION AREA ALREADY IS OVER CENTRAL WISCONSIN AND
IS HEADED EAST... IT WOULD SEEM MORE THAN REASONABLE THIS WOULD
IMPACT CENTRAL LOWER MICHIGAN THIS EVENING. THERE IS GOOD LIFT IN
THE DGZ AS THIS FEATURE MOVES THROUGH THE AREA SO THAT SHOULD HELP
THE SNOWFLAKE PRODUCTION. WITH SURFACE DEW POINTS IN THE MID 20S
THE SNOW WILL WET BULB DOWN THE AIR TEMP QUICKLY SO SNOW WILL REACH
THE GROUND.
ONCE THAT FEATURE MOVES EAST OF THE CWA LATER THIS EVENING SHORT
WAVE RIDGING FOLLOWS LATE TONIGHT INTO MIDDAY THURSDAY. THAT
SHOULD ALLOW THE SKIES TO BECOME PARTLY CLOUDY...AT LEAST FOR A
TIME.
THEN WE HAVE THE ISSUE OF OUR STORM ON THURSDAY NIGHT. THE GFS AND
NAM HAVE BEEN CONSISTENTLY FARTHER NORTH THEN THE ECMWF HAS BEEN
WITH THIS SYSTEM. HOWEVER... THE ECMWF HAS FINALLY SHOWED A
SIGNIFICANT SHIFT NORTHWARD IN THE TRACK OF THE SYSTEM THURSDAY
NIGHT. THE REGIONAL GEM IS FARTHER NORTH AND WEST THAN IS THE
HEMISPHERIC GEM... TRACKING THE LOW NEAR DETROIT LATE THURSDAY
NIGHT. THERE IS SIGNIFICANT FGEN SUPPORT OF THIS EVENT AS IT IS
EXIT REGION OF 165 KNOT 300 MB JET CORE THAT TURNS CYCLONIC AS
IT HEADS NORTHEAST TOWARD CENTRAL OHIO FRIDAY MORNING. THIS ALSO
CREATES QUIET THE TROWAL FEATURE WITH STRONG ISOTROPIC LIFT. THERE
IS 3 TO 4 G/KG OF WATER NEAR 700 MB WHILE THIS IS GOING ON SO
SNOWFALL AMOUNTS OF 3 TO 6 INCHES SHOULD BE EASY TO DO WITH THIS
SET UP.
I WOULD HAVE ISSUED A WINTER STORM WATCH FOR THIS EVENT EXPECT FOR
THE ISSUE OF MODEL UNCERTAINTY. I WILL LET THE MIDNIGHT SHIFT
CONSIDER DOING JUST THAT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 400 PM EST WED FEB 22 2012
UNSETTLED/ACTIVE WEATHER IS EXPECTED TO GENERALLY CONTINUE THROUGH
THE LONG TERM PORTION OF THE FORECAST...IF NOT THE NEXT COUPLE OF
WEEKS. MAIN ITEMS OF CONCERN ARE LINGERING SNOW ON FRI...LAKE EFFECT
FRI NIGHT/SAT...SYSTEM COMING IN LATE SUN THROUGH MON...AND LAKE
EFFECT AGAIN ON TUE.
AN ACTIVE JET STREAM IS EXPECTED TO AFFECT MOST OF THE COUNTRY
THROUGH THE NEXT WEEK. WE ARE EXPECTING TO SEE STRONG PIECES OF
ENERGY BE PUSHED ACROSS THE COUNTRY...FUELED BY A VERY STRONG JET
OVER THE NRN PACIFIC. A LOT OF THIS ENERGY IS EXPECTED TO DIVE SE
INTO THE WRN STATES...BEFORE LIFTING E/NE TOWARD THE GREAT LAKES
REGION.
WE WILL SEE THE FIRST IN THE SERIES OF PV ANOMALIES/WAVES BE MOVING
OUT OF THE AREA AFTER DEPOSITING ACCUMULATING SNOW THU NIGHT AND
INTO FRI. IN THE WAKE OF THIS PHASED UPPER FEATURE...A POOL OF
ARCTIC AIR TO OUR NW WILL BE TAPPED AND WILL PUSH INTO THE AREA.
SYNOPTIC SNOW WILL LIKELY BE ONGOING EARLY ON FRI BEFORE TAPERING
OFF DURING THE DAY. THE SNOW WILL TRANSITION TO SOME LAKE EFFECT AS
H850 TEMPS DROP DOWN TO AROUND -10C TO -12C. WE COULD SEE SOME
DECENT LAKE EFFECT ACCUMS FOR MAINLY NW FAVORED AREAS WITH MOISTURE
POTENTIALLY UP THROUGH 10K FT LATE FRI AND FRI NIGHT. INVERSION
HEIGHTS WILL GRADUALLY FALL THROUGH SAT AS THE UPPER FLOW WILL
TRANSITION TO ANTI-CYCLONIC BY SAT EVENING.
WE WILL SEE A BRIEF BREAK IN THE WEATHER THEN SAT NIGHT THROUGH A
GOOD PORTION OF SUN FOR MOST AREAS AS RIDGING BUILDS IN. NW AREAS
COULD SEE SOME LIGHT PCPN SUN AFTERNOON AS WAA/ISENTROPIC ASCENT
STRENGTHENS AHEAD OF THE NEXT SYSTEM. THE UNSETTLED WEATHER WILL
SPREAD ACROSS THE ENTIRE AREA SUN NIGHT AS THE NEXT STRONG WAVE
DIVING INTO THE SW U.S. EARLY IN THE WEEKEND WILL LIFT NE. THIS WILL
LIKELY TAP SOME WARMER AND MOIST AIR FROM THE GULF AND ADVECT IT
INTO THE AREA LATE SUN THROUGH MON MORNING. PCPN COULD START OFF AS
SNOW...BUT SHOULD CHANGE OVER TO RAIN FOR A PERIOD SUN NIGHT AND
EARLY MON. THUNDER CAN NOT EVEN BE RULED OUT WITH THE STRONG FORCING
ASSOCIATED WITH THE SYSTEM. NOT CONFIDENT ENOUGH YET TO ADD THUNDER
INTO THE FCST.
THE COLD FRONT WILL MOVE THROUGH ON MON...AND A FLOOD OF COLDER AIR
WILL MOVE IN ACROSS THE STATE. THIS WILL HELP TO START THE LAKE
EFFECT BACK UP AS H850 TEMPS DROP BACK DOWN TO AROUND -10C TO -12C.
MODELS ARE INDICATING THOUGH THAT THE LOW LEVEL FLOW WILL TEND TO BE
NE WITH THE WAY THE RIDGE BUILDS IN FROM THE NW. THIS WILL TEND TO
LIMIT THE LAKE EFFECT CHCS AND AMOUNTS. QUITE A BIT OF UNCERTAINTY
WITH REGARDS TO TIMING AND TRACK WITH ANOTHER WAVE THAT IS EXPECTED
TO LIFT OUT FROM THE WRN U.S. BY MID WEEK NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 650 PM EST WED FEB 22 2012
MAIN CHANGES WERE TO REFINE TIMING OF PRECIPITATION TONIGHT. BASED
ON SURFACE OBSERVATIONS IN WI...HAVE REMOVED LIFR CONDITIONS AT
GRR. MODELS CONTINUE TO SUPPORT A RELATIVELY HEAVY AND NARROW BAND
OF SNOW POTENTIALLY AFFECTING THE MKG...GRR...AND POSSIBLY LAN
TERMINALS MAINLY BEFORE 06Z. WE BELIEVE WITH A FAIR AMOUNT OF
CONFIDENCE THAT RAIN ALONG THE I-96 CORRIDOR SHOULD TRANSITION TO
SNOW AFT 03Z.
ALTHOUGH NOT MENTIONED IN THE TAFS...EXPECT A GRADUAL IMPROVEMENT
TO MVFR/VFR CONDITIONS IN THE 06-12Z TIME FRAME. WE HOPE TO
ADDRESS THIS A BIT MORE SPECIFICALLY IN THE NEXT TAF PACKAGE.
&&
.MARINE...
ISSUED AT 1045 PM EST WED FEB 22 2012
HAVE ALLOWED THE SMALL CRAFT ADVISORY TO EXPIRE. WINDS AND WAVES
WILL CONTINUE A RAPID DOWNWARD TREND.
&&
.HYDROLOGY...
ISSUED AT 400 PM EST WED FEB 22 2012
NO SIGNIFICANT HYDROLOGY ISSUES ARE EXPECTED AS THE PRECIPITATION
THAT FALLS WILL BE IN THE FROM FOR SNOW. NONE OF RIVERS ARE AT OR
ABOVE ACTION STAGE CURRENTLY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER STORM WATCH FROM THURSDAY AFTERNOON THROUGH FRIDAY
MORNING FOR MIZ037>040-043>046-050>052-056>059-064>067-
071>074.
LM...NONE.
&&
$$
UPDATE...TJT
SYNOPSIS...TJT
SHORT TERM...WDM
LONG TERM....NJJ
AVIATION...TJT
MARINE...TJT
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
655 PM EST WED FEB 22 2012
.UPDATE...
ISSUED AT 650 PM EST WED FEB 22 2012
MADE TIMING ADJUSTMENTS TO PRECIPITATION CHANCES THROUGH 2 AM.
PRECIPITATION TYPE IS EXPECTED TO BE RAIN INITIALLY AS IT NOW IS
IN WI...THANKS TO CURRENT SURFACE TEMPERATURES AND DEWPOINTS OVER
MUCH OF LOWER MI. A GRADUAL CHANGEOVER TO SNOW SHOULD OCCUR MAINLY
AFTER 10 PM.
HRRR SHORT RANGE GUIDANCE CONTINUES TO SUPPORT A NARROW BAND OF
SNOW CROSSING THE I-96 CORRIDOR TONIGHT...AND THIS IS SUPPORTED BY
THE 22/12Z NCEP NESTED ARW/NMM NAM. IMPACTS ARE EXPECTED TO BE
MINIMAL GIVEN TIMING AND EXPECTED INTENSITY.
UPDATE ISSUED AT 444 PM EST WED FEB 22 2012
WILL BE ISSUING A WINTER STORM WATCH SHORTLY FOR THE CWA FROM
THURSDAY AFTERNOON INTO FRIDAY MORNING BASED LARGELY ON LATEST
ECMWF GUIDANCE. WILL TRY TO HAVE THE WATCH OUT BY 5 PM.
&&
.SYNOPSIS...
ISSUED AT 400 PM EST WED FEB 22 2012
A WEAK SYSTEM WILL MOVE THROUGH THE AREA EARLY TONIGHT BRINGING A
PERIOD OF SNOW SHOWERS TO AREAS NEAR AND SOUTH OF INTERSTATE 96. A
HIGH PRESSURE RIDGE WILL MOVE ACROSS THE AREA DURING THE MID
MORNING HOURS OF THURSDAY BRINGING PARTIAL CLEARING TO THE AREA.
THEN A STORM DEVELOPING IN THE SOUTHERN PLAINS WILL HEAD TO THE
SOUTH CENTRAL GREAT LAKES FOR LATE THURSDAY NIGHT AND HEAD INTO
NEW ENGLAND FRIDAY. THAT WILL BRING A PERIOD OF SIGNIFICANT
SNOWFALL TO THE AREA THURSDAY NIGHT INTO FRIDAY. SOME LAKE EFFECT
SNOW IS EXPECTED INTO SATURDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 400 PM EST WED FEB 22 2012
THERE IS THE THREAT FOR A SIGNIFICANT SNOWFALL EVENT THURSDAY
NIGHT INTO FRIDAY. CURRENT THINKING IS 4 TO 7 INCHES OVER THE
CENTRAL CWA... NEAR INTERSTATE 96. MOST OF THE SNOW SHOULD FALL
DURING THE MID TO LATE EVENING HOURS OF THURSDAY NIGHT INTO THE
MID MORNING HOURS OF FRIDAY.
THERE IS ALSO THE THREAT FOR A BRIEF BURST OF SIGNIFICANT SNOW THIS
EVENING AS A SHORTWAVE OVER WISCONSIN HEADS EAST ACROSS LAKE
MICHIGAN AND INTENSIFIES THIS EVENING. BOTH THE HRRR SUGGESTS UP
TO .25 INCHES OF QPF IN 3 HOURS OVER PARTS OF NORTHERN OTTAWA AND
CENTRAL AND NORTHERN KENT COUNTIES BY BETWEEN 9 PM AND MIDNIGHT.
SINCE THE PRECIPITATION AREA ALREADY IS OVER CENTRAL WISCONSIN AND
IS HEADED EAST... IT WOULD SEEM MORE THAN REASONABLE THIS WOULD
IMPACT CENTRAL LOWER MICHIGAN THIS EVENING. THERE IS GOOD LIFT IN
THE DGZ AS THIS FEATURE MOVES THROUGH THE AREA SO THAT SHOULD HELP
THE SNOWFLAKE PRODUCTION. WITH SURFACE DEW POINTS IN THE MID 20S
THE SNOW WILL WET BULB DOWN THE AIR TEMP QUICKLY SO SNOW WILL REACH
THE GROUND.
ONCE THAT FEATURE MOVES EAST OF THE CWA LATER THIS EVENING SHORT
WAVE RIDGING FOLLOWS LATE TONIGHT INTO MIDDAY THURSDAY. THAT
SHOULD ALLOW THE SKIES TO BECOME PARTLY CLOUDY...AT LEAST FOR A
TIME.
THEN WE HAVE THE ISSUE OF OUR STORM ON THURSDAY NIGHT. THE GFS AND
NAM HAVE BEEN CONSISTENTLY FARTHER NORTH THEN THE ECMWF HAS BEEN
WITH THIS SYSTEM. HOWEVER... THE ECMWF HAS FINALLY SHOWED A
SIGNIFICANT SHIFT NORTHWARD IN THE TRACK OF THE SYSTEM THURSDAY
NIGHT. THE REGIONAL GEM IS FARTHER NORTH AND WEST THAN IS THE
HEMISPHERIC GEM... TRACKING THE LOW NEAR DETROIT LATE THURSDAY
NIGHT. THERE IS SIGNIFICANT FGEN SUPPORT OF THIS EVENT AS IT IS
EXIT REGION OF 165 KNOT 300 MB JET CORE THAT TURNS CYCLONIC AS
IT HEADS NORTHEAST TOWARD CENTRAL OHIO FRIDAY MORNING. THIS ALSO
CREATES QUIET THE TROWAL FEATURE WITH STRONG ISOTROPIC LIFT. THERE
IS 3 TO 4 G/KG OF WATER NEAR 700 MB WHILE THIS IS GOING ON SO
SNOWFALL AMOUNTS OF 3 TO 6 INCHES SHOULD BE EASY TO DO WITH THIS
SET UP.
I WOULD HAVE ISSUED A WINTER STORM WATCH FOR THIS EVENT EXPECT FOR
THE ISSUE OF MODEL UNCERTAINTY. I WILL LET THE MIDNIGHT SHIFT
CONSIDER DOING JUST THAT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 400 PM EST WED FEB 22 2012
UNSETTLED/ACTIVE WEATHER IS EXPECTED TO GENERALLY CONTINUE THROUGH
THE LONG TERM PORTION OF THE FORECAST...IF NOT THE NEXT COUPLE OF
WEEKS. MAIN ITEMS OF CONCERN ARE LINGERING SNOW ON FRI...LAKE EFFECT
FRI NIGHT/SAT...SYSTEM COMING IN LATE SUN THROUGH MON...AND LAKE
EFFECT AGAIN ON TUE.
AN ACTIVE JET STREAM IS EXPECTED TO AFFECT MOST OF THE COUNTRY
THROUGH THE NEXT WEEK. WE ARE EXPECTING TO SEE STRONG PIECES OF
ENERGY BE PUSHED ACROSS THE COUNTRY...FUELED BY A VERY STRONG JET
OVER THE NRN PACIFIC. A LOT OF THIS ENERGY IS EXPECTED TO DIVE SE
INTO THE WRN STATES...BEFORE LIFTING E/NE TOWARD THE GREAT LAKES
REGION.
WE WILL SEE THE FIRST IN THE SERIES OF PV ANOMALIES/WAVES BE MOVING
OUT OF THE AREA AFTER DEPOSITING ACCUMULATING SNOW THU NIGHT AND
INTO FRI. IN THE WAKE OF THIS PHASED UPPER FEATURE...A POOL OF
ARCTIC AIR TO OUR NW WILL BE TAPPED AND WILL PUSH INTO THE AREA.
SYNOPTIC SNOW WILL LIKELY BE ONGOING EARLY ON FRI BEFORE TAPERING
OFF DURING THE DAY. THE SNOW WILL TRANSITION TO SOME LAKE EFFECT AS
H850 TEMPS DROP DOWN TO AROUND -10C TO -12C. WE COULD SEE SOME
DECENT LAKE EFFECT ACCUMS FOR MAINLY NW FAVORED AREAS WITH MOISTURE
POTENTIALLY UP THROUGH 10K FT LATE FRI AND FRI NIGHT. INVERSION
HEIGHTS WILL GRADUALLY FALL THROUGH SAT AS THE UPPER FLOW WILL
TRANSITION TO ANTI-CYCLONIC BY SAT EVENING.
WE WILL SEE A BRIEF BREAK IN THE WEATHER THEN SAT NIGHT THROUGH A
GOOD PORTION OF SUN FOR MOST AREAS AS RIDGING BUILDS IN. NW AREAS
COULD SEE SOME LIGHT PCPN SUN AFTERNOON AS WAA/ISENTROPIC ASCENT
STRENGTHENS AHEAD OF THE NEXT SYSTEM. THE UNSETTLED WEATHER WILL
SPREAD ACROSS THE ENTIRE AREA SUN NIGHT AS THE NEXT STRONG WAVE
DIVING INTO THE SW U.S. EARLY IN THE WEEKEND WILL LIFT NE. THIS WILL
LIKELY TAP SOME WARMER AND MOIST AIR FROM THE GULF AND ADVECT IT
INTO THE AREA LATE SUN THROUGH MON MORNING. PCPN COULD START OFF AS
SNOW...BUT SHOULD CHANGE OVER TO RAIN FOR A PERIOD SUN NIGHT AND
EARLY MON. THUNDER CAN NOT EVEN BE RULED OUT WITH THE STRONG FORCING
ASSOCIATED WITH THE SYSTEM. NOT CONFIDENT ENOUGH YET TO ADD THUNDER
INTO THE FCST.
THE COLD FRONT WILL MOVE THROUGH ON MON...AND A FLOOD OF COLDER AIR
WILL MOVE IN ACROSS THE STATE. THIS WILL HELP TO START THE LAKE
EFFECT BACK UP AS H850 TEMPS DROP BACK DOWN TO AROUND -10C TO -12C.
MODELS ARE INDICATING THOUGH THAT THE LOW LEVEL FLOW WILL TEND TO BE
NE WITH THE WAY THE RIDGE BUILDS IN FROM THE NW. THIS WILL TEND TO
LIMIT THE LAKE EFFECT CHCS AND AMOUNTS. QUITE A BIT OF UNCERTAINTY
WITH REGARDS TO TIMING AND TRACK WITH ANOTHER WAVE THAT IS EXPECTED
TO LIFT OUT FROM THE WRN U.S. BY MID WEEK NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 650 PM EST WED FEB 22 2012
MAIN CHANGES WERE TO REFINE TIMING OF PRECIPITATION TONIGHT. BASED
ON SURFACE OBSERVATIONS IN WI...HAVE REMOVED LIFR CONDITIONS AT
GRR. MODELS CONTINUE TO SUPPORT A RELATIVELY HEAVY AND NARROW BAND
OF SNOW POTENTIALLY AFFECTING THE MKG...GRR...AND POSSIBLY LAN
TERMINALS MAINLY BEFORE 06Z. WE BELIEVE WITH A FAIR AMOUNT OF
CONFIDENCE THAT RAIN ALONG THE I-96 CORRIDOR SHOULD TRANSITION TO
SNOW AFT 03Z.
ALTHOUGH NOT MENTIONED IN THE TAFS...EXPECT A GRADUAL IMPROVEMENT
TO MVFR/VFR CONDITIONS IN THE 06-12Z TIME FRAME. WE HOPE TO
ADDRESS THIS A BIT MORE SPECIFICALLY IN THE NEXT TAF PACKAGE.
&&
.MARINE...
ISSUED AT 400 PM EST WED FEB 22 2012
WINDS AND WAVES ARE STILL IN THE SMALL CRAFT ADVISORY RANGE LATE
THIS AFTERNOON. WINDS AND WAVES WILL DIMINISH TONIGHT OVERNIGHT AS
THE SURFACE RIDGE GETS CLOSER TO THE AREA. I WILL LET THE ADVISORY
EXPIRE AS SCHEDULED.
&&
.HYDROLOGY...
ISSUED AT 400 PM EST WED FEB 22 2012
NO SIGNIFICANT HYDROLOGY ISSUES ARE EXPECTED AS THE PRECIPITATION
THAT FALLS WILL BE IN THE FROM FOR SNOW. NONE OF RIVERS ARE AT OR
ABOVE ACTION STAGE CURRENTLY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER STORM WATCH FROM THURSDAY AFTERNOON THROUGH FRIDAY
MORNING FOR MIZ037>040-043>046-050>052-056>059-064>067-
071>074.
LM...SMALL CRAFT ADVISORY UNTIL 8 PM EST THIS EVENING FOR LMZ844>849.
&&
$$
UPDATE...TJT
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM....NJJ
AVIATION...TJT
MARINE...WDM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
407 PM EST TUE FEB 21 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 400 PM EST TUE FEB 21 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW OVER NRN
MN WITH A SHORTWAVE TROUGH EXTENDING INTO NW WI. 850-500 MB QVECTOR
CONV AND MID LEVEL FGEN ASSOCIATED WITH THE SHRTWV SUPPORTED A BAND
OF SNOW ACROSS CNTRL UPPER MI. SO...FAR ACCUMULATIONS HAVE BEEN
LIGHT...GENERALLY LESS THAN AN INCH. AT THE SFC...A 992 MB LOW WAS
LOCATED NEAR KINL WITH MOST OF THE SNOW AHEAD OF A TROUGH EXTENDING
TO THE SE THROUGH WRN UPPER MI INTO NE WI. ADDITIONAL SNOW OVER NE
MN WITH WRAP-AROUND MOISTURE NEAR THE MID LEVEL LOW WAS MOVING BACK
INTO NW WI.
RADAR TRENDS AND NAM/RUC FCST SUGGEST THAT THE INITIAL SNOWBAND WILL
MOVE OUT OF CNTRL UPPER MI INTO THE ERN CWA LATE THIS AFTERNOON AND
EVENING. THE SNOW AREA OVER MN IS ALSO EXPECTED TO SHIFT INTO WRN
UPPER MI THIS EVENING BRINGING POTENTIAL FOR ADDITIONAL LIGHT
ACCUMULATIONS OF AN INCH OR TWO. EVEN THOUGH THE STRONGER SYNOPTIC
FORCING IS FCST NEAR KIWD... THE COMBINATION OF CONVERGENT WRLY FLOW
AND 850 MB TEMPS DROPPING TO AROUND -8C WILL ALSO RESULT IN SOME
LAKE ENHANCED SNOW OVER NW UPPER MI WITH SNOWFALL AMOUNTS INTO THE 1
TO 3 INCH RANGE. AS THE WINDS VEER SLIGHTLY WED...THE LAKE ENHANCED
SNOW SHOULD ALSO MOVE INTO LOCATIONS NEAR LAKE SUPERIOR EAST OF
MUNISING. THE REMAINING SNOW OVER THE WEST WILL DIMINISH WED AS
HIGH PRESSURE AND DRIER AIR MOVE INTO THE AREA BEHIND THE DEPARTING
MID LEVEL LOW.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 400 PM EST TUE FEB 21 2012
THE 500MB LOW CURRENTLY OVER N MN THIS AFTERNOON WILL BE ALONG THE
ONTARIO/QUEBEC BORDER TO BEGIN THIS PERIOD. THE NEXT TROUGH SLIDING
IN FROM THE NW WILL BE BROAD...STRETCHING FROM W MANITOBA TO E LAKE
SUPERIOR/CENTRAL LAKE MI THURSDAY AFTERNOON. FCST MODELS BEGIN TO
DIVERGE EARLIER THAN NORMAL...THURSDAY AFTERNOON /DAY 2/.
THE 21/06Z NAM IS A QUICK OUTLIER...WITH A CLOSED LOW DEVELOPING
NEAR THE MACKINAC BRIDGE...BEFORE SHIFTING TO S QUEBEC FRIDAY
AFTERNOON. WHILE THE 21/06Z GFS HAS A SIMILAR TREND...IT IS APPROX 6
HOURS SLOWER. THE 21/09Z SREF TENDS TO FOLLOW A SOLUTION SIMILAR TO
THE GFS...WHILE THE 21/00Z CANADIAN IS AN AVERAGE BETWEEN THE
GFS/SREF AND THE MUCH SLOWER 21/00Z ECMWF /LOW OVER W ONTARIO WHILE
THE GFS HAS IT OVER THE S ONTARIO/QUEBEC BORDER/. THE ECMWF DOES NOT
PLACE THE LOW OVER THE S ONTARIO/QUEBEC BORDER UNTIL 12Z
SATURDAY...OR 18HRS BEHIND THE GFS. WILL PUSH THIS FORECAST CLOSER
TO A GFS SOLUTION THROUGH THE END OF THE WORK WEEK. THIS WILL RESULT
IN UPPER MI AND LAKE SUPERIOR STUCK BETWEEN THE FIRST SFC LOW
EXITING INTO QUEBEC AT 00Z THURSDAY...WITH THE STRONGER LOW
DEVELOPING OVER THE N PLAINS AND CENTRAL CANADA. A WEAK SFC TROUGH
WILL CONNECT THE TWO. THE MOST SIGNIFICANT CONTRAST THE MODELS CAN
BE SEEN OFF THE 00Z FRIDAY SFC MAP. THERE IS A CLUSTER OF MODELS
/GFS/NAM/SREF/ WITH THE LOW OVER CENTRAL TO N LOWER MI. BY CONTRAST
THE CANADIAN HAS IT ALONG THE LOWER MI/IA/OH BORDER...WITH THE ECMWF
ALONG THE CONFLUENCE OF THE OHIO AND MISSISSIPPI RIVERS. AS STATED
ABOVE...WILL PUSH THE FCST TO A MORE CENTRAL LOWER MI SOLUTION AT
00Z FRIDAY. THIS WILL KEEP THE BULK OF THE SYNOPTIC MOISTURE FALLING
JUST SOUTH OF THE CWA.
AFTER 18Z FRIDAY ALL OF THE SOLUTIONS COME INTO SOME BASIC AGREEMENT
OVER OUR CWA...WITH N TO NW WINDS AND 850MB TEMPS IN THE -8 TO -12C
RANGE. 850MB TEMPS OF -14 TO -16C SHOULD BE COMMON BY SUNDAY
AFTERNOON...BEFORE WAA ON MORE SW WINDS TAKE HOLD SATURDAY NIGHT.
STRONG SSW WINDS WILL LIKELY TAKE HOLD SUNDAY AFTERNOON INTO SUNDAY
NIGHT /DEPENDING ON THE TIMING OF THE NEXT LOW. THE ECMWF ENDS UP
BEING ROUGHLY 12 HOURS SLOWER THAN THE GFS WITH THIS NEXT SYSTEM
COMING OUT OF THE PLAINS. A STRONGER MORE NORTHERLY LOW OFF THE
ECMWF WOULD BRING 850MB TEMPS OF 2C...COMPARED TO THE WARMEST
READINGS OFF THE GFS OF -6C. AT 00Z TUESDAY THE SFC 983MB SFC LOW
OFF THE ECMWF IS OVER NE MN...WHILE AT THE SAME TIME THE
WEAKER/QUICKER GFS HAS A 1003MB LOW OVER FAR S QUEBEC. GIVEN THE
LOWER CONFIDENCE WITH THE FORECAST WILL NOT DIVE TO MUCH INTO THE
SPECIFICS...AND KEEP A CONSENSUS GOING FROM SATURDAY NIGHT ON. EVEN
WITH ALL THE DIFFERENCES...SUNDAY NIGHT LOOKED TO BE A GOOD
OPPORTUNITY TO INCLUDE LIKELY POPS OVER S CENTRAL UPPER MI.
OTHERWISE...WILL KEEP CHANCE OF LESS POPS GOING THROUGH MUCH OF THE
PERIOD WITH LOWER THAN NORMAL CONFIDENCE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1247 PM EST TUE FEB 21 2012
WITH LOW LEVEL MOISTURE IN PLACE OVER THE REGION...EXPECT IFR
CONDITIONS TO PERSIST AT KCMX/KSAW THIS AFTERNOON WHILE DOWNSLOPE
SRLY FLOW INTO KIWD RESULTS IN CIGS AOA MVFR THRESHOLD.
TONIGHT...WRLY WINDS WITH LAKE ENHANCED SNOW WILL KEEP MAINLY IFR
CONDITIONS OR LOWER END MVFR AT KCMX/KIWD. HOWEVER...CIGS SHOULD
LIFT A BIT A KSAW AS WINDS VEER MORE SW TO W.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 400 PM EST TUE FEB 21 2012
AS LOW PRESSURE SLIDES EASTWARD THROUGH NRN LAKE SUPERIOR AND
INTO QUEBEC BY WED AFTERNOON...WRLY WINDS WILL INCREASE TO 20 TO 30
KT TONIGHT INTO WED. WINDS WILL DIMINISH LATE WED INTO WED NIGHT AS
HIGH PRES BUILDS INTO THE UPPER GREAT LAKES. WINDS WILL THEN REMAIN
RELATIVELY LIGHT INTO UNTIL FRI WHEN NRLY WINDS OF 15 TO 25 KT ARE
POSSIBLE AS LOW PRESSURE MOVES TO THE SOUTH OF THE REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS GAYLORD MI
105 PM EST TUE FEB 21 2012
.UPDATE...
ISSUED AT 102 PM EST TUE FEB 21 2012
NOT MUCH OF ANYTHING GOING ON ACROSS THE FORECAST AREA AT EARLY
AFTERNOON...SAVE FOR SOME LIGHT SNOW AROUND SAGINAW BAY. SO HAVE
BEEN TRYING VAINLY TO GET THE PUBLIC/AVIATION FORECASTS SQUARED
AWAY TO REFLECT NEW REALITY...WHICH WILL FOCUS ON BAND OF
PRECIPITATION COMING OUT OF OF WISCONSIN ASSOCIATED WITH NORTHERN
BRANCH SHORT WAVE SPINNING ITS WAY ACROSS THE UPPER MIDWEST. THIS
SHOULD PUSH INTO FAR NORTHWEST LOWER MICHIGAN TOWARD 21Z...THEN
CROSS EASTERN UPPER AND FAR NORTHERN LOWER DURING THE EVENING
HOURS. MAY SEE SOME DRIZZLE DEVELOP FARTHER SOUTH THIS EVENING AS
LOWER CEILINGS SPREAD NORTHEAST AS WELL.
UPDATE ISSUED AT 1002 AM EST TUE FEB 21 2012
NO CHANGES MADE TO GOING FORECAST AT THIS POINT...WILL MAKE TWEAKS
AS NEEDED GOING FORWARD WITH RESPECT TO PRECIPITATION START TIMES.
UPDATE ISSUED AT 642 AM EST TUE FEB 21 2012
PRECIPITATION ONSET LOOKING ON TRACK GIVEN CURRENT OBSERVATIONS
SHOWING SNOW BREAKING OUT OVER SOUTHEAST WISCONSIN AND LIKELY OVER
THE SOUTHERN THIRD OF LAKE MICHIGAN AT THIS HOUR. RAOB JUST SENT
UP AT APX SHOWS IMPRESSIVE DRY WEDGE TO OVERCOME /30C DEWPOINT
DEPRESSIONS AT H85 WITH DRY WEDGE EXTENDING TO H6/ SO EXPECT THAT
WHILE CURRENT RADAR ECHOES LOOK A LITTLE OMINOUS...IT WILL TAKE
MANY MORE HOURS FOR PRECIPITATION TO FILL IN. THIS IS IN GOOD
AGREEMENT WITH 08/09Z HRRR WHICH SUGGESTS THAT PRECIPITATION WILL
STRUGGLE TO MAKE IT MUCH FURTHER NORTH THAN M-72 BY NOON.
SO...LITTLE TWEAKS IN THE POP/WEATHER DEPARTMENT. UPDATED SKY
BASED ON SLIGHTLY FASTER CLOUD-UP OVER EASTERN UPPER...BUT
OTHERWISE...LITTLE CHANGES NEEDED IN THIS UPDATE.
&&
.SYNOPSIS...
ISSUED AT 333 AM EST TUE FEB 21 2012
HIGH PRESSURE WILL EXIT INTO THE WESTERN ATLANTIC TODAY...AS
WEAKENING LOW PRESSURE TRACKS THROUGH THE GREAT LAKES INTO THIS
EVENING. THIS SYSTEM WILL BRING A BRIEF ROUND OF LIGHT RAIN AND SNOW
SHOWERS TO THE REGION THROUGH LATE EVENING...THOUGH WITH LITTLE TO
NO SNOW ACCUMULATION EXPECTED. LOOKING INTO THE REST OF THE WORK
WEEK...SEVERAL ADDITIONAL WEAK WEATHER SYSTEMS WILL PROGRESS THROUGH
THE AREA...EACH SUPPLYING SMALL CHANCES FOR SOME LIGHT RAIN OR SNOW.
HOWEVER...NO SIGNIFICANT SNOW ACCUMULATION IS EXPECTED THROUGH AT
LEAST SATURDAY.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 333 AM EST TUE FEB 21 2012
EARLY MORNING SURFACE ANALYSIS REVEALS DOUBLE-BARRELED LOW PRESSURE
SYSTEM ADVANCING NORTH AND EAST TOWARDS THE FORECAST AREA. 30-40 KT
LOW LEVEL JET RIDING UP AND OVER LOW LEVEL COOL DOME HAS PRODUCED A
FAIRLY WIDESPREAD REGION OF GENERALLY LIGHT PRECIPITATION THAT IS
PUSHING INTO EASTERN WISCONSIN AS OF THIS WRITING. DOUBLE BARRELED
STRUCTURE AT THE SURFACE HAS BEEN PRODUCED BY COMPETING MID AND
UPPER LEVEL SHORTWAVES...ONE COMPACT CENTER OVER NORTHERN MISSOURI
AND ANOTHER LARGER SCALE FEATURE OVER NORTH DAKOTA. MODEL TRENDS
OVER THE PAST 48 HOURS HAVE BEEN FOR A STRONGER AND FURTHER SOUTH
NORTHERN FEATURE...WHICH WILL DO A GOOD JOB OF KICKING THE SOUTHERN
WAVE SOUTH AND EAST OF OUR REGION TODAY. THIS LEAVES A GENERALLY
WEAK FORCING FOR ASCENT AS THE BEST DEEP MOISTURE SHIFTS EAST WITH
THE SOUTHERN WAVE...ALLOWING ONLY MODEST MOISTENING IN OUR REGION AS
MODEST QVECTOR CONVERGENCE AND FGEN FORCING ARRIVE.
00Z RAOBS FROM APX/GRB SHOW A PRETTY DRY ANTECEDENT AIRMASS WITH
PWATS BELOW TWO TENTHS OF AN INCH WITH DRY SOUTHEASTERLY FLOW IN THE
LOW LEVELS HELPING KEEP THIS DRY PROFILE IN PLACE. SO...MODEL
TRENDS FOR SLOWER PRECIPITATION ARRIVAL...AND LOWER PRECIPITATION
AMOUNTS ARE NOT A SURPRISE...AND EXPECT MINIMAL IMPACTS FOR THE
REGION TODAY. LIGHT SNOW...WHICH MAY ARRIVE IN BROKEN ELEMENTS
RATHER THAN A SOLID SHIELD...SHOULD ADVANCE FROM SOUTHWEST TO
NORTHEAST ACROSS NORTHERN LOWER BY BY NOON...WITH ANY ACTIVITY
HOLDING OFF IN EASTERN UPPER UNTIL LATE IN THE DAY. PRECIPITATION
COVERAGE MAY ACTUALLY INCREASE SOME TOWARDS EVENING AS QG FORCING
ASSOCIATED WITH THE NORTHERN STREAM FINALLY ARRIVES...WITH
INCREASINGLY CYCLONIC BOUNDARY LAYER FLOW ALSO ASSISTING.
A MIX WITH RAIN ALSO LOOKS TO BE IN THE CARDS...AS BOUNDARY LAYER
TEMPERATURES MAKE A RUN AT THE UPPER 30S NEAR THE LAKES AS
PRECIPITATION ARRIVES. THIS WILL ALSO BE HELPED BY THE GENERALLY
LIGHT PRECIPITATION RATES...WHICH WILL BETTER ALLOW THE SURFACE
LAYER TO DICTATE PRECIPITATION TYPE. EVEN WHERE PRECIPITATION
REMAINS ALL SNOW...INCREASING SUN ANGLES /EVEN WITH CLOUD COVER/
SUGGESTS THAT EVEN OVER THE HIGHER TERRAIN OF NORTHERN LOWER...WHERE
PRECIPITATION REMAINS ALL SNOW...THE HALF INCH OF SNOW EXPECTED WILL
HAVE TROUBLE STICKING TO AREA ROADWAYS.
AFOREMENTIONED SURFACE LOW SETTLES OVER NORTHERN LAKE SUPERIOR
TONIGHT WITH T85S FALLING TO ABOUT -8C WITH CONTINUED DECENT
SYNOPTIC MOISTURE AND CYCLONIC LLEVEL FLOW SUGGESTING LAKE ENHANCED
SHSN ACTIVITY WILL LIKELY PERSIST THROUGH MUCH OF THE NIGHT. WITH
COOLING BOUNDARY LAYER TEMPERATURES...EXPECT SNOW TO STICK A LITTLE
BETTER AND HAVE PAINTED UP TO AN INCH IN THE FORECAST OVERNIGHT OVER
EASTERN UPPER...AS WELL AS THE HIGHER TERRAIN OF NORTHERN LOWER
WHERE SOME UPSLOPE ENHANCEMENT UNDER WEST-SOUTHWEST FLOW WILL BOOST
PRECIPITATION TOTALS SLIGHTLY. WILL LEAN TOWARDS THE WARMER END OF
THE GUIDANCE SUITE FOR TEMPERATURES GIVEN CLOUD COVER AND
PRECIPITATION...WITH UPPER 20S LOOKING GOOD FOR MOST SPOTS.
LOW PRESSURE NORTH OF THE REGION GRADUALLY FILLS AND SHIFTS EAST ON
WEDNESDAY WITH A GRADUAL DOWN-TICK IN MOISTURE AND SLIGHT WARMING OF
TEMPS AT H85. THIS INDICATES THAT SHSN ACTIVITY WILL GRADUALLY
BECOME MORE AND MORE RESTRICTED TO NEAR THE LOW CENTER /EASTERN
UPPER/ AND WILL ALLOW POPS TO GRADUALLY FADE NORTH DURING THE DAY.
LIKELIES LOOK GOOD FOR A TIME EARLY...HOWEVER AS THERE IS NO SUDDEN
INFLUX OF DRY/WARM AIR TO SHUT THINGS DOWN. WHILE THERE WILL BE A
GOOD DEAL OF CLOUD COVER...T92 AROUND -3C SUGGEST MID TO PERHAPS
UPPER 30S WILL AGAIN BE IN ORDER.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 333 AM EST TUE FEB 21 2012
WEDNESDAY NIGHT THROUGH FRIDAY...CONVOLUTED PATTERN EXPECTED ACROSS
THE GREAT LAKES REGION TO WRAP UP THE WORK WEEK...WITH HONESTLY NOT
VERY HIGH CONFIDENCE IN ANY TIMING OF VARIOUS PRECIP CHANCES.
SECONDARY SHORTWAVE OF SHORT TERM MENTION ABOVE OVER THE NORTHERN
PLAINS WILL BE EXITING STAGE RIGHT WEDNESDAY EVENING...LEAVING
IMPRESSIVE PLUME OF PACIFIC JET ENERGY TO FLOOD JUST ABOUT THE
ENTIRE CONUS HEADING INTO FRIDAY. EMBEDDED WITHIN THE FLOW ARE
SEVERAL PROGGED SHORTWAVES...THOUGH THEIR PLACEMENT AND TIMING VARY
CONSIDERABLY FROM RUN TO RUN AND MODEL TO MODEL. ABOUT THE ONLY
THING THAT CAN BE SAID WITH SOME CONFIDENCE IS THAT VARIOUS MAINLY
SMALL PRECIP CHANCES WILL EXIST DURING THE LATE WEEK PERIOD...THOUGH
HIGHLY DOUBTING THE AMPLIFIED SOLUTIONS OF THE BOTH THE 21/00Z NAM
AND 20/12Z ECMWF GIVEN THE RAGING PACIFIC "FIREHOSE" JET ENERGY THAT
SHOULD EASILY KEEP THE FLOW PROGRESSIVE. INSTEAD WE APPEAR TO BE
LEFT WITH A MYRIAD OF WEAKER UPPER WAVES THAT WILL TRAVERSE A
BRIEFLY STATIONARY TIGHT THERMAL GRADIENT RESIDING OVER THE SOUTHERN
GREAT LAKES. AS SUCH...PRECIP CHANCES SHOULD BE GREATEST OVER
SOUTHERN COUNTIES...AND ENTIRELY POSSIBLE THAT NOT A WHOLE LOT
HAPPENS NORTH OF M-72. STILL...GIVEN PLENTY OF UNCERTAINTY...WILL
MAINTAIN SMALL CHANCE POPS PRETTY MUCH AREAWIDE...THOUGH WILL REMOVE
PRECIP MENTION NORTH OF M-72 ON THURSDAY. WILL ALSO KEEP PRECIP TYPE
AS ALL SNOW AT THIS POINT...THOUGH SOME HINTS EXIST THAT A RAIN/SNOW
MIX IS POSSIBLE ACROSS SOUTHERN AREAS ON THURSDAY AS STRONGER
SHORTWAVE ARRIVES. TEMPS BASICALLY TO CONTINUE ABOVE NORMAL THROUGH
THE PERIOD...MAINLY DRIVEN BY MILD OVERNIGHT LOWS.
LATER PERIODS (FRIDAY NIGHT THROUGH MONDAY)...POTENTIALLY MORE
ACTIVE WEATHER PATTERN STILL APPEARS IN THE WORKS HEADING INTO LATE
WEEKEND...AND MORE LIKELY THE FIRST HALF OF NEXT WEEK...WITH
INCREASING SIGNS OF STRONG NORTH PACIFIC JET COLLAPSING INTO SOME
DEGREE OF WESTERN CONUS TROUGHING. THIS SHOULD HAVE THE NEXT EFFECT
OF SLOWING DOWN THE WAVE TRAIN THROUGH THE CONUS...ALLOWING MORE
TIME FOR AMPLIFICATION OF VARIOUS FEATURES...AND PERHAPS SETTING UP
A SOUTHWEST FLOW REGIME FOR A TIME FROM LATER SUNDAY THROUGH MIDWEEK
(SOMETHING NOT SEEN AT ALL THIS WINTER BUT MUCH MORE TYPICAL OF A LA
NINA EPISODE). CONFIDENCE WITH ANY PARTICULAR PIECE OF GUIDANCE IS
VERY LOW...BUT THE FLAVOR OF THE FORECAST WILL REMAIN INTACT...
FEATURING INCREASING CHANCES FOR SNOW THROUGH MONDAY. AT THIS
JUNCTURE...TEMPS LOOK TO AVERAGE ABOUT NORMAL...THOUGH BIG BUST
POTENTIAL IS THERE LATE IN THE PERIOD SHOULD ANY SYSTEM AMPLIFY
SIGNIFICANT TO OUR WEST (WHICH WOULD HELP DRAG UP SOME QUITE WARM
AIR THIS WAY).
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 102 PM EST TUE FEB 21 2012
EXPECT IFR CONDITIONS TO DEVELOP AT ALL TERMINALS LATER THIS
AFTERNOON AND EARLY EVENING...IMPROVING TO MVFR OVERNIGHT.
&&
.MARINE...
ISSUED AT 333 AM EST TUE FEB 21 2012
SMALL CRAFTS ONGOING OVER ALL NEARSHORE ZONES...AND EXPECT THIS TO
CONTINUE THROUGH AT LEAST WEDNESDAY AS LOW PRESSURE TAKING SHAPE
OVER NORTHERN MINNESOTA TODAY SHIFTS OVER LAKE SUPERIOR TONIGHT WITH
SOUTHEAST WINDS SHIFTING SOUTHWEST TONIGHT. WINDS/WAVES SHOULD
SUBSIDE WEDNESDAY NIGHT AND THURSDAY AS WEAK AREA OF HIGH PRESSURE
BUILDS IN FROM THE NORTHWEST. AS THE WINDS SHIFT SOUTHWEST
TONIGHT...CAN/T COMPLETELY RULE OUT A FEW LOW-END GALES ON THE
NORTHWEST LAKE MICHIGAN COAST...BUT FLOW TRAJECTORY DOES NOT FAVOR
MUCH IN THE WAY OF COASTAL CONVERGENCE ENHANCEMENT...SO EXPECT MOST
SPOTS TO GUST TO AROUND 30KTS.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JPB
SHORT TERM...ARNOTT
LONG TERM....LAWRENCE
AVIATION...
MARINE...ARNOTT
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1255 PM EST TUE FEB 21 2012
.SYNOPSIS...
ISSUED AT 452 AM EST TUE FEB 21 2012
A COLD FRONT WILL PASS THROUGH THE AREA TODAY BRINGING A PERIOD OF
RAIN AND SNOW. THE STEADIEST PRECIPITATION SHOULD OCCUR THIS
MORNING...WITH THE MIX BECOMING LIGHTER AND MORE SCATTERED INTO THE
AFTERNOON. PORTIONS OF CENTRAL LOWER MICHIGAN MAY PICK A LIGHT
DUSTING OF SNOW...OTHERWISE LITTLE TO NO SNOW ACCUMULATION IS
EXPECTED. SCATTERED LIGHT SNOW SHOULD LINGER INTO TONIGHT BEFORE
SKIES GRADUALLY CLEAR ON WEDNESDAY.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH WEDNESDAY EVENING)
ISSUED AT 1255 PM EST TUE FEB 21 2012
OUR BAND OF SNOW HAS LIFTED OUT OF THE CWA AS OF 1230 PM. THERE IS
STILL THE AREA OF SNOW OVER CENTRAL WISCONSIN HEADING EAST WITH THE
COLD FRONT OCCASION. THE SOUTHERN EDGE OF THAT SNOW AREA HAS LIFTED
NORTH WITH TIME HOWEVER I BELIEVE THE ADDED MOISTURE FROM LAKE
MICHIGAN WILL HELP IT`S CAUSE AND AS PER THE HRRR WILL RAPIDLY
DEVELOP SOUTHWARD AS IT MOVES INTO SOUTHWEST LOWER MICHIGAN AFTER 3
PM THIS AFTERNOON. I USED THE TIMING TOOL TO FIGURE OUT WHERE IT
WOULD BE WHEN... AND IT WOULD REACH MKG BY 3 PM BUT IT WOULD NOT GET
TO LAN UNTIL 6 PM. I USED MODIFIED 15Z SREF POP TO MODEL THIS
FEATURE. BOTH THE NAM AND RUC SHOW STRONG LIFT IN THE BELOW 10000 FT
AGL WITH THE BEST LIFT NEAR 3000-5000 FT AGL. THAT IS WELL BELOW THE
DGZ BUT THE RUC SHOWS SOME OF THE DGZ IS IN THE LIFT ZONE SO THERE
JUST MAY BE SNOW SNOW WITH THIS. IN ANY EVENT IT WILL BE BRIEF...
LESS THAN 2 HOURS AT ANY ONE LOCATION.
THERE SEEMS TO BE TO MUCH DRY AIR WRAPPING IN BEHIND THE FRONT AS
THE SYSTEM LIFTS NORTHEAST FOR LAKE EFFECT TO HAVE MUCH IMPACT. EVEN
SO I HAVE CHC POP OVER THE NW CWA EVEN SO. SKIES SHOULD CLEAR FROM
SW TO NORTHEAST OVERNIGHT AS THIS DRY AIR WRAPS INTO THE AREA FROM
THE SOUTHWEST.
WEDNESDAY SHOULD SEE LITTLE IN THE WAY OF SIGNIFICANT WEATHER AS THE
SHORTWAVE RIDGE MOVES THROUGH THE AREA.
SOME ISSUES WITH THE NEXT SYSTEM... ECMWF VERSE THE GFS/NAM. SO NOT
MUCH CONFIDENCE THERE... I HAVE THE POP TOWARD THURSDAY MORNING. A
FAIR AMOUNT OF WARM AIR AHEAD OF THIS SO IF ANYTHING THIS WILL
MOSTLY BE RAIN.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 452 AM EST TUE FEB 21 2012
PLENTY OF CONCERNS IN THE LONG TERM REMAIN WITH MODEL DISCREPANCIES
AND PRECIPITATION TYPE/COVERAGE THE MAIN CONCERNS.
HAVE MAINTAINED CHANCE POPS WEDNESDAY NIGHT INTO THURSDAY...BUT
CONFIDENCE IS LOW. MODELS INDICATE A SHORTWAVE TROUGH SWINGING
THROUGH THE GREAT LAKES DURING THIS TIME FRAME. THE ASSOCIATED
SURFACE LOW HAS A VARIED TRACK...WITH THE NAME BEING WELL NORTH OF
THE FORECAST AREA AND THE EUROPEAN OFF TO THE SOUTH. GIVEN MODEL
DISCREPANCIES...MADE LITTLE CHANGE. THE NAM WOULD BRING IN WARMER
AIR AND AND CHANGE MOST OF THE FORECAST AREA OVER TO RAIN.
THE SURFACE LOW MOVES INTO THE EASTERN GREAT LAKES THURSDAY NIGHT
WITH SOME LINGERING SNOW OVER LOWER MICHIGAN. CONFIDENCE CONTINUES
TO BE LOW IN THIS PERIOD AS WELL WITH LOW POSITION RANGING FROM
QUEBEC (NAM) TO SOUTHERN OHIO (EURO) AT 12Z FRIDAY.
COLDER AIR FILTERS IN FOR FRIDAY NIGHT AND SATURDAY WITH LAKE EFFECT
NEAR LAKE MICHIGAN. THE GFS PUSHES A LOW INTO THE GREAT LAKES FOR
SUNDAY AND SUNDAY NIGHT WHILE THE EURO IS DRY (LOW IN COLORADO).
LEFT POPS IN THE FORECAST FOR NOW...BUT HPC BELIEVES THE GFS IS WAY
TOO QUICK. EURO WOULD THEN BRING RAIN INTO THE AREA ON MONDAY IS A
GOOD SOUTHERLY FLOW.
BOTTOM LINE...LITTLE CONFIDENCE IN THE LONG TERM PERIOD...WITH
MULTIPLE SHORTWAVE/S TO DEAL WITH IN GENERAL UPPER TROUGHING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY MORNING)
ISSUED AT 1255 PM EST TUE FEB 21 2012
IFR CIGS AND MVFR TO VFR VSBY COVER THE TAF SITES AT 1245 PM THIS
AFTERNOON. I EXPECT THE VSBY INCREASE TO VFR AT ALL BUT MKG WHICH IS
BY LAKE MICHIGAN THIS AFTERNOON AS THE PRECIPITATION HAS ENDED.
HOWEVER THE BAND OF SNOW OVER WISCONSIN WILL CROSS SOUTHWEST LOWER
MICHIGAN BETWEEN 20Z AND 02Z FROM WEST TO EAST AND LAST LESS THAN 2
HOURS AT ANY ONE LOCATION. QUESTIONABLE TEMPERATURES FOR ALL SNOW OR
ALL RAIN. FOR NOW I WENT WITH RAIN BUT DO NOT BE SURPRISED IF IT IS
SNOW (SEE SHORT TERM FOR DETAILS ON THIS). ONCE THE COLD FRONT
OCCLUSION COMES THROUGH EARLY THIS EVENING EXPECT RAPID IMPROVEMENT
FOR THE I-94 TAF SITES BUT IT MAY TAKE UNTIL AFTER 09Z FOR THE I-96
TAFS TO IMPROVE ABOVE MVFR.
I EXPECT SOLID VFR ALL TAF SITES WEDNESDAY FROM 12Z THROUGH AT LEAST
06Z THURSDAY.
&&
.MARINE...
ISSUED AT 452 AM EST TUE FEB 21 2012
HAVE EXPANDED THE SMALL CRAFT FOR ALL NEARSHORE ZONES STARTING 2 PM
THIS AFTERNOON. WINDS WILL PIVOT TO THE SW BEHIND THE FRONT LATER
THIS AFTERNOON. SPEEDS SHOULD APPROACH 30 KNOTS BY LATE IN THE DAY.
&&
.HYDROLOGY...
ISSUED AT 452 AM EST TUE FEB 21 2012
RIVER LEVELS ARE TO REMAIN NEARLY STEADY AND BELOW ACTION STAGE
THROUGH THE PERIOD. NO SIGNIFICANT RUNOFF IS FORECASTED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 8 PM EST WEDNESDAY FOR LMZ846>849.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 8 PM EST
WEDNESDAY FOR LMZ844-845.
&&
$$
SYNOPSIS...JK
SHORT TERM...WDM
LONG TERM....DUKE
AVIATION...WDM
MARINE...JK
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1005 AM EST TUE FEB 21 2012
.UPDATE...
ISSUED AT 1002 AM EST TUE FEB 21 2012
NO CHANGES MADE TO GOING FORECAST AT THIS POINT...WILL MAKE TWEAKS
AS NEEDED GOING FORWARD WITH RESPECT TO PRECIPITATION START TIMES.
UPDATE ISSUED AT 642 AM EST TUE FEB 21 2012
PRECIPITATION ONSET LOOKING ON TRACK GIVEN CURRENT OBSERVATIONS
SHOWING SNOW BREAKING OUT OVER SOUTHEAST WISCONSIN AND LIKELY OVER
THE SOUTHERN THIRD OF LAKE MICHIGAN AT THIS HOUR. RAOB JUST SENT
UP AT APX SHOWS IMPRESSIVE DRY WEDGE TO OVERCOME /30C DEWPOINT
DEPRESSIONS AT H85 WITH DRY WEDGE EXTENDING TO H6/ SO EXPECT THAT
WHILE CURRENT RADAR ECHOES LOOK A LITTLE OMINOUS...IT WILL TAKE
MANY MORE HOURS FOR PRECIPITATION TO FILL IN. THIS IS IN GOOD
AGREEMENT WITH 08/09Z HRRR WHICH SUGGESTS THAT PRECIPITATION WILL
STRUGGLE TO MAKE IT MUCH FURTHER NORTH THAN M-72 BY NOON.
SO...LITTLE TWEAKS IN THE POP/WEATHER DEPARTMENT. UPDATED SKY
BASED ON SLIGHTLY FASTER CLOUD-UP OVER EASTERN UPPER...BUT
OTHERWISE...LITTLE CHANGES NEEDED IN THIS UPDATE.
&&
.SYNOPSIS...
ISSUED AT 333 AM EST TUE FEB 21 2012
HIGH PRESSURE WILL EXIT INTO THE WESTERN ATLANTIC TODAY...AS
WEAKENING LOW PRESSURE TRACKS THROUGH THE GREAT LAKES INTO THIS
EVENING. THIS SYSTEM WILL BRING A BRIEF ROUND OF LIGHT RAIN AND SNOW
SHOWERS TO THE REGION THROUGH LATE EVENING...THOUGH WITH LITTLE TO
NO SNOW ACCUMULATION EXPECTED. LOOKING INTO THE REST OF THE WORK
WEEK...SEVERAL ADDITIONAL WEAK WEATHER SYSTEMS WILL PROGRESS THROUGH
THE AREA...EACH SUPPLYING SMALL CHANCES FOR SOME LIGHT RAIN OR SNOW.
HOWEVER...NO SIGNIFICANT SNOW ACCUMULATION IS EXPECTED THROUGH AT
LEAST SATURDAY.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 333 AM EST TUE FEB 21 2012
EARLY MORNING SURFACE ANALYSIS REVEALS DOUBLE-BARRELED LOW PRESSURE
SYSTEM ADVANCING NORTH AND EAST TOWARDS THE FORECAST AREA. 30-40 KT
LOW LEVEL JET RIDING UP AND OVER LOW LEVEL COOL DOME HAS PRODUCED A
FAIRLY WIDESPREAD REGION OF GENERALLY LIGHT PRECIPITATION THAT IS
PUSHING INTO EASTERN WISCONSIN AS OF THIS WRITING. DOUBLE BARRELED
STRUCTURE AT THE SURFACE HAS BEEN PRODUCED BY COMPETING MID AND
UPPER LEVEL SHORTWAVES...ONE COMPACT CENTER OVER NORTHERN MISSOURI
AND ANOTHER LARGER SCALE FEATURE OVER NORTH DAKOTA. MODEL TRENDS
OVER THE PAST 48 HOURS HAVE BEEN FOR A STRONGER AND FURTHER SOUTH
NORTHERN FEATURE...WHICH WILL DO A GOOD JOB OF KICKING THE SOUTHERN
WAVE SOUTH AND EAST OF OUR REGION TODAY. THIS LEAVES A GENERALLY
WEAK FORCING FOR ASCENT AS THE BEST DEEP MOISTURE SHIFTS EAST WITH
THE SOUTHERN WAVE...ALLOWING ONLY MODEST MOISTENING IN OUR REGION AS
MODEST QVECTOR CONVERGENCE AND FGEN FORCING ARRIVE.
00Z RAOBS FROM APX/GRB SHOW A PRETTY DRY ANTECEDENT AIRMASS WITH
PWATS BELOW TWO TENTHS OF AN INCH WITH DRY SOUTHEASTERLY FLOW IN THE
LOW LEVELS HELPING KEEP THIS DRY PROFILE IN PLACE. SO...MODEL
TRENDS FOR SLOWER PRECIPITATION ARRIVAL...AND LOWER PRECIPITATION
AMOUNTS ARE NOT A SURPRISE...AND EXPECT MINIMAL IMPACTS FOR THE
REGION TODAY. LIGHT SNOW...WHICH MAY ARRIVE IN BROKEN ELEMENTS
RATHER THAN A SOLID SHIELD...SHOULD ADVANCE FROM SOUTHWEST TO
NORTHEAST ACROSS NORTHERN LOWER BY BY NOON...WITH ANY ACTIVITY
HOLDING OFF IN EASTERN UPPER UNTIL LATE IN THE DAY. PRECIPITATION
COVERAGE MAY ACTUALLY INCREASE SOME TOWARDS EVENING AS QG FORCING
ASSOCIATED WITH THE NORTHERN STREAM FINALLY ARRIVES...WITH
INCREASINGLY CYCLONIC BOUNDARY LAYER FLOW ALSO ASSISTING.
A MIX WITH RAIN ALSO LOOKS TO BE IN THE CARDS...AS BOUNDARY LAYER
TEMPERATURES MAKE A RUN AT THE UPPER 30S NEAR THE LAKES AS
PRECIPITATION ARRIVES. THIS WILL ALSO BE HELPED BY THE GENERALLY
LIGHT PRECIPITATION RATES...WHICH WILL BETTER ALLOW THE SURFACE
LAYER TO DICTATE PRECIPITATION TYPE. EVEN WHERE PRECIPITATION
REMAINS ALL SNOW...INCREASING SUN ANGLES /EVEN WITH CLOUD COVER/
SUGGESTS THAT EVEN OVER THE HIGHER TERRAIN OF NORTHERN LOWER...WHERE
PRECIPITATION REMAINS ALL SNOW...THE HALF INCH OF SNOW EXPECTED WILL
HAVE TROUBLE STICKING TO AREA ROADWAYS.
AFOREMENTIONED SURFACE LOW SETTLES OVER NORTHERN LAKE SUPERIOR
TONIGHT WITH T85S FALLING TO ABOUT -8C WITH CONTINUED DECENT
SYNOPTIC MOISTURE AND CYCLONIC LLEVEL FLOW SUGGESTING LAKE ENHANCED
SHSN ACTIVITY WILL LIKELY PERSIST THROUGH MUCH OF THE NIGHT. WITH
COOLING BOUNDARY LAYER TEMPERATURES...EXPECT SNOW TO STICK A LITTLE
BETTER AND HAVE PAINTED UP TO AN INCH IN THE FORECAST OVERNIGHT OVER
EASTERN UPPER...AS WELL AS THE HIGHER TERRAIN OF NORTHERN LOWER
WHERE SOME UPSLOPE ENHANCEMENT UNDER WEST-SOUTHWEST FLOW WILL BOOST
PRECIPITATION TOTALS SLIGHTLY. WILL LEAN TOWARDS THE WARMER END OF
THE GUIDANCE SUITE FOR TEMPERATURES GIVEN CLOUD COVER AND
PRECIPITATION...WITH UPPER 20S LOOKING GOOD FOR MOST SPOTS.
LOW PRESSURE NORTH OF THE REGION GRADUALLY FILLS AND SHIFTS EAST ON
WEDNESDAY WITH A GRADUAL DOWN-TICK IN MOISTURE AND SLIGHT WARMING OF
TEMPS AT H85. THIS INDICATES THAT SHSN ACTIVITY WILL GRADUALLY
BECOME MORE AND MORE RESTRICTED TO NEAR THE LOW CENTER /EASTERN
UPPER/ AND WILL ALLOW POPS TO GRADUALLY FADE NORTH DURING THE DAY.
LIKELIES LOOK GOOD FOR A TIME EARLY...HOWEVER AS THERE IS NO SUDDEN
INFLUX OF DRY/WARM AIR TO SHUT THINGS DOWN. WHILE THERE WILL BE A
GOOD DEAL OF CLOUD COVER...T92 AROUND -3C SUGGEST MID TO PERHAPS
UPPER 30S WILL AGAIN BE IN ORDER.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 333 AM EST TUE FEB 21 2012
WEDNESDAY NIGHT THROUGH FRIDAY...CONVOLUTED PATTERN EXPECTED ACROSS
THE GREAT LAKES REGION TO WRAP UP THE WORK WEEK...WITH HONESTLY NOT
VERY HIGH CONFIDENCE IN ANY TIMING OF VARIOUS PRECIP CHANCES.
SECONDARY SHORTWAVE OF SHORT TERM MENTION ABOVE OVER THE NORTHERN
PLAINS WILL BE EXITING STAGE RIGHT WEDNESDAY EVENING...LEAVING
IMPRESSIVE PLUME OF PACIFIC JET ENERGY TO FLOOD JUST ABOUT THE
ENTIRE CONUS HEADING INTO FRIDAY. EMBEDDED WITHIN THE FLOW ARE
SEVERAL PROGGED SHORTWAVES...THOUGH THEIR PLACEMENT AND TIMING VARY
CONSIDERABLY FROM RUN TO RUN AND MODEL TO MODEL. ABOUT THE ONLY
THING THAT CAN BE SAID WITH SOME CONFIDENCE IS THAT VARIOUS MAINLY
SMALL PRECIP CHANCES WILL EXIST DURING THE LATE WEEK PERIOD...THOUGH
HIGHLY DOUBTING THE AMPLIFIED SOLUTIONS OF THE BOTH THE 21/00Z NAM
AND 20/12Z ECMWF GIVEN THE RAGING PACIFIC "FIREHOSE" JET ENERGY THAT
SHOULD EASILY KEEP THE FLOW PROGRESSIVE. INSTEAD WE APPEAR TO BE
LEFT WITH A MYRIAD OF WEAKER UPPER WAVES THAT WILL TRAVERSE A
BRIEFLY STATIONARY TIGHT THERMAL GRADIENT RESIDING OVER THE SOUTHERN
GREAT LAKES. AS SUCH...PRECIP CHANCES SHOULD BE GREATEST OVER
SOUTHERN COUNTIES...AND ENTIRELY POSSIBLE THAT NOT A WHOLE LOT
HAPPENS NORTH OF M-72. STILL...GIVEN PLENTY OF UNCERTAINTY...WILL
MAINTAIN SMALL CHANCE POPS PRETTY MUCH AREAWIDE...THOUGH WILL REMOVE
PRECIP MENTION NORTH OF M-72 ON THURSDAY. WILL ALSO KEEP PRECIP TYPE
AS ALL SNOW AT THIS POINT...THOUGH SOME HINTS EXIST THAT A RAIN/SNOW
MIX IS POSSIBLE ACROSS SOUTHERN AREAS ON THURSDAY AS STRONGER
SHORTWAVE ARRIVES. TEMPS BASICALLY TO CONTINUE ABOVE NORMAL THROUGH
THE PERIOD...MAINLY DRIVEN BY MILD OVERNIGHT LOWS.
LATER PERIODS (FRIDAY NIGHT THROUGH MONDAY)...POTENTIALLY MORE
ACTIVE WEATHER PATTERN STILL APPEARS IN THE WORKS HEADING INTO LATE
WEEKEND...AND MORE LIKELY THE FIRST HALF OF NEXT WEEK...WITH
INCREASING SIGNS OF STRONG NORTH PACIFIC JET COLLAPSING INTO SOME
DEGREE OF WESTERN CONUS TROUGHING. THIS SHOULD HAVE THE NEXT EFFECT
OF SLOWING DOWN THE WAVE TRAIN THROUGH THE CONUS...ALLOWING MORE
TIME FOR AMPLIFICATION OF VARIOUS FEATURES...AND PERHAPS SETTING UP
A SOUTHWEST FLOW REGIME FOR A TIME FROM LATER SUNDAY THROUGH MIDWEEK
(SOMETHING NOT SEEN AT ALL THIS WINTER BUT MUCH MORE TYPICAL OF A LA
NINA EPISODE). CONFIDENCE WITH ANY PARTICULAR PIECE OF GUIDANCE IS
VERY LOW...BUT THE FLAVOR OF THE FORECAST WILL REMAIN INTACT...
FEATURING INCREASING CHANCES FOR SNOW THROUGH MONDAY. AT THIS
JUNCTURE...TEMPS LOOK TO AVERAGE ABOUT NORMAL...THOUGH BIG BUST
POTENTIAL IS THERE LATE IN THE PERIOD SHOULD ANY SYSTEM AMPLIFY
SIGNIFICANT TO OUR WEST (WHICH WOULD HELP DRAG UP SOME QUITE WARM
AIR THIS WAY).
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 642 AM EST TUE FEB 21 2012
VFR CONDITIONS CONTINUE AT EACH OF THE TAF SITES...BUT
DETERIORATING CONDITIONS ARE EXPECTED AS AXIS OF LOW PRESSURE
SHIFTS TOWARDS THE AREA FROM THE SOUTHWEST...BRINGING A ROUND OF
SNOW...WHICH MAY BE MIXED WITH RAIN.
EXPECT MVFR-IFR CIGS/VSBYS IN LIGHT SNOW TO ARRIVE AT MBL/TVC LATE
THIS MORNING...AND PLN/APN THIS AFTERNOON. AT THIS TIME...EXPECT
PRECIPITATION TO BE QUITE LIGHT...WITH VSBYS LIKELY HAVING TROUBLE
REMAINING IFR FOR MORE THAN A FEW HOURS. ALSO...SOME RAIN MAY MIX
WITH THE SNOW AT TIMES AT MBL/TVC. THIS EVENING...AS THE INITIAL
BATCH OF PRECIPITATION SHIFT NORTH AND EAST...EXPECT RESIDUAL LAKE
ENHANCED SHSN THROUGH THE OVERNIGHT AT APN/PLN...WITH MVFR
CONDITIONS /PERHAPS IFR VSBYS AT PLN?/ PERSISTING THROUGH 12Z
WEDNESDAY. MORE IMPROVEMENT IS EXPECTED AT TVC...AND EXPECIALLY
MBL WHERE A RETURN TO VFR CIGS IS EXPECTED AFTER MIDNIGHT.
AS FOR WINDS...LLWS CONCERNS ARE ENDING AT THIS HOUR AS MIXING
STRENGTHENS AT LOW LEVELS. EXPECT SOUTHEAST WINDS 5-10KTS TO VEER
SOUTHERLY 5-10KTS DURING THE DAY TODAY...BEFORE SHIFTING SOUTHWEST
AND INCREASING TO 12G18KTS TONIGHT.
&&
.MARINE...
ISSUED AT 333 AM EST TUE FEB 21 2012
SMALL CRAFTS ONGOING OVER ALL NEARSHORE ZONES...AND EXPECT THIS TO
CONTINUE THROUGH AT LEAST WEDNESDAY AS LOW PRESSURE TAKING SHAPE
OVER NORTHERN MINNESOTA TODAY SHIFTS OVER LAKE SUPERIOR TONIGHT WITH
SOUTHEAST WINDS SHIFTING SOUTHWEST TONIGHT. WINDS/WAVES SHOULD
SUBSIDE WEDNESDAY NIGHT AND THURSDAY AS WEAK AREA OF HIGH PRESSURE
BUILDS IN FROM THE NORTHWEST. AS THE WINDS SHIFT SOUTHWEST
TONIGHT...CAN/T COMPLETELY RULE OUT A FEW LOW-END GALES ON THE
NORTHWEST LAKE MICHIGAN COAST...BUT FLOW TRAJECTORY DOES NOT FAVOR
MUCH IN THE WAY OF COASTAL CONVERGENCE ENHANCEMENT...SO EXPECT MOST
SPOTS TO GUST TO AROUND 30KTS.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 6 PM EST WEDNESDAY FOR LHZ346-349.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EST WEDNESDAY FOR LMZ323-341-342-
344-345-346.
LS...NONE.
&&
$$
UPDATE...JPB
SHORT TERM...ARNOTT
LONG TERM....LAWRENCE
AVIATION...ARNOTT
MARINE...ARNOTT
AREA FORECAST DISCUSSION
NWS GAYLORD MI
645 AM EST TUE FEB 21 2012
.UPDATE...
ISSUED AT 642 AM EST TUE FEB 21 2012
PRECIPITATION ONSET LOOKING ON TRACK GIVEN CURRENT OBSERVATIONS
SHOWING SNOW BREAKING OUT OVER SOUTHEAST WISCONSIN AND LIKELY OVER
THE SOUTHERN THIRD OF LAKE MICHIGAN AT THIS HOUR. RAOB JUST SENT
UP AT APX SHOWS IMPRESSIVE DRY WEDGE TO OVERCOME /30C DEWPOINT
DEPRESSIONS AT H85 WITH DRY WEDGE EXTENDING TO H6/ SO EXPECT THAT
WHILE CURRENT RADAR ECHOES LOOK A LITTLE OMINOUS...IT WILL TAKE
MANY MORE HOURS FOR PRECIPITATION TO FILL IN. THIS IS IN GOOD
AGREEMENT WITH 08/09Z HRRR WHICH SUGGESTS THAT PRECIPITATION WILL
STRUGGLE TO MAKE IT MUCH FURTHER NORTH THAN M-72 BY NOON.
SO...LITTLE TWEAKS IN THE POP/WEATHER DEPARTMENT. UPDATED SKY
BASED ON SLIGHTLY FASTER CLOUD-UP OVER EASTERN UPPER...BUT
OTHERWISE...LITTLE CHANGES NEEDED IN THIS UPDATE.
&&
.SYNOPSIS...
ISSUED AT 333 AM EST TUE FEB 21 2012
HIGH PRESSURE WILL EXIT INTO THE WESTERN ATLANTIC TODAY...AS
WEAKENING LOW PRESSURE TRACKS THROUGH THE GREAT LAKES INTO THIS
EVENING. THIS SYSTEM WILL BRING A BRIEF ROUND OF LIGHT RAIN AND SNOW
SHOWERS TO THE REGION THROUGH LATE EVENING...THOUGH WITH LITTLE TO
NO SNOW ACCUMULATION EXPECTED. LOOKING INTO THE REST OF THE WORK
WEEK...SEVERAL ADDITIONAL WEAK WEATHER SYSTEMS WILL PROGRESS THROUGH
THE AREA...EACH SUPPLYING SMALL CHANCES FOR SOME LIGHT RAIN OR SNOW.
HOWEVER...NO SIGNIFICANT SNOW ACCUMULATION IS EXPECTED THROUGH AT
LEAST SATURDAY.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 333 AM EST TUE FEB 21 2012
EARLY MORNING SURFACE ANALYSIS REVEALS DOUBLE-BARRELED LOW PRESSURE
SYSTEM ADVANCING NORTH AND EAST TOWARDS THE FORECAST AREA. 30-40 KT
LOW LEVEL JET RIDING UP AND OVER LOW LEVEL COOL DOME HAS PRODUCED A
FAIRLY WIDESPREAD REGION OF GENERALLY LIGHT PRECIPITATION THAT IS
PUSHING INTO EASTERN WISCONSIN AS OF THIS WRITING. DOUBLE BARRELED
STRUCTURE AT THE SURFACE HAS BEEN PRODUCED BY COMPETING MID AND
UPPER LEVEL SHORTWAVES...ONE COMPACT CENTER OVER NORTHERN MISSOURI
AND ANOTHER LARGER SCALE FEATURE OVER NORTH DAKOTA. MODEL TRENDS
OVER THE PAST 48 HOURS HAVE BEEN FOR A STRONGER AND FURTHER SOUTH
NORTHERN FEATURE...WHICH WILL DO A GOOD JOB OF KICKING THE SOUTHERN
WAVE SOUTH AND EAST OF OUR REGION TODAY. THIS LEAVES A GENERALLY
WEAK FORCING FOR ASCENT AS THE BEST DEEP MOISTURE SHIFTS EAST WITH
THE SOUTHERN WAVE...ALLOWING ONLY MODEST MOISTENING IN OUR REGION AS
MODEST QVECTOR CONVERGENCE AND FGEN FORCING ARRIVE.
00Z RAOBS FROM APX/GRB SHOW A PRETTY DRY ANTECEDENT AIRMASS WITH
PWATS BELOW TWO TENTHS OF AN INCH WITH DRY SOUTHEASTERLY FLOW IN THE
LOW LEVELS HELPING KEEP THIS DRY PROFILE IN PLACE. SO...MODEL
TRENDS FOR SLOWER PRECIPITATION ARRIVAL...AND LOWER PRECIPITATION
AMOUNTS ARE NOT A SURPRISE...AND EXPECT MINIMAL IMPACTS FOR THE
REGION TODAY. LIGHT SNOW...WHICH MAY ARRIVE IN BROKEN ELEMENTS
RATHER THAN A SOLID SHIELD...SHOULD ADVANCE FROM SOUTHWEST TO
NORTHEAST ACROSS NORTHERN LOWER BY BY NOON...WITH ANY ACTIVITY
HOLDING OFF IN EASTERN UPPER UNTIL LATE IN THE DAY. PRECIPITATION
COVERAGE MAY ACTUALLY INCREASE SOME TOWARDS EVENING AS QG FORCING
ASSOCIATED WITH THE NORTHERN STREAM FINALLY ARRIVES...WITH
INCREASINGLY CYCLONIC BOUNDARY LAYER FLOW ALSO ASSISTING.
A MIX WITH RAIN ALSO LOOKS TO BE IN THE CARDS...AS BOUNDARY LAYER
TEMPERATURES MAKE A RUN AT THE UPPER 30S NEAR THE LAKES AS
PRECIPITATION ARRIVES. THIS WILL ALSO BE HELPED BY THE GENERALLY
LIGHT PRECIPITATION RATES...WHICH WILL BETTER ALLOW THE SURFACE
LAYER TO DICTATE PRECIPITATION TYPE. EVEN WHERE PRECIPITATION
REMAINS ALL SNOW...INCREASING SUN ANGLES /EVEN WITH CLOUD COVER/
SUGGESTS THAT EVEN OVER THE HIGHER TERRAIN OF NORTHERN LOWER...WHERE
PRECIPITATION REMAINS ALL SNOW...THE HALF INCH OF SNOW EXPECTED WILL
HAVE TROUBLE STICKING TO AREA ROADWAYS.
AFOREMENTIONED SURFACE LOW SETTLES OVER NORTHERN LAKE SUPERIOR
TONIGHT WITH T85S FALLING TO ABOUT -8C WITH CONTINUED DECENT
SYNOPTIC MOISTURE AND CYCLONIC LLEVEL FLOW SUGGESTING LAKE ENHANCED
SHSN ACTIVITY WILL LIKELY PERSIST THROUGH MUCH OF THE NIGHT. WITH
COOLING BOUNDARY LAYER TEMPERATURES...EXPECT SNOW TO STICK A LITTLE
BETTER AND HAVE PAINTED UP TO AN INCH IN THE FORECAST OVERNIGHT OVER
EASTERN UPPER...AS WELL AS THE HIGHER TERRAIN OF NORTHERN LOWER
WHERE SOME UPSLOPE ENHANCEMENT UNDER WEST-SOUTHWEST FLOW WILL BOOST
PRECIPITATION TOTALS SLIGHTLY. WILL LEAN TOWARDS THE WARMER END OF
THE GUIDANCE SUITE FOR TEMPERATURES GIVEN CLOUD COVER AND
PRECIPITATION...WITH UPPER 20S LOOKING GOOD FOR MOST SPOTS.
LOW PRESSURE NORTH OF THE REGION GRADUALLY FILLS AND SHIFTS EAST ON
WEDNESDAY WITH A GRADUAL DOWN-TICK IN MOISTURE AND SLIGHT WARMING OF
TEMPS AT H85. THIS INDICATES THAT SHSN ACTIVITY WILL GRADUALLY
BECOME MORE AND MORE RESTRICTED TO NEAR THE LOW CENTER /EASTERN
UPPER/ AND WILL ALLOW POPS TO GRADUALLY FADE NORTH DURING THE DAY.
LIKELIES LOOK GOOD FOR A TIME EARLY...HOWEVER AS THERE IS NO SUDDEN
INFLUX OF DRY/WARM AIR TO SHUT THINGS DOWN. WHILE THERE WILL BE A
GOOD DEAL OF CLOUD COVER...T92 AROUND -3C SUGGEST MID TO PERHAPS
UPPER 30S WILL AGAIN BE IN ORDER.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 333 AM EST TUE FEB 21 2012
WEDNESDAY NIGHT THROUGH FRIDAY...CONVOLUTED PATTERN EXPECTED ACROSS
THE GREAT LAKES REGION TO WRAP UP THE WORK WEEK...WITH HONESTLY NOT
VERY HIGH CONFIDENCE IN ANY TIMING OF VARIOUS PRECIP CHANCES.
SECONDARY SHORTWAVE OF SHORT TERM MENTION ABOVE OVER THE NORTHERN
PLAINS WILL BE EXITING STAGE RIGHT WEDNESDAY EVENING...LEAVING
IMPRESSIVE PLUME OF PACIFIC JET ENERGY TO FLOOD JUST ABOUT THE
ENTIRE CONUS HEADING INTO FRIDAY. EMBEDDED WITHIN THE FLOW ARE
SEVERAL PROGGED SHORTWAVES...THOUGH THEIR PLACEMENT AND TIMING VARY
CONSIDERABLY FROM RUN TO RUN AND MODEL TO MODEL. ABOUT THE ONLY
THING THAT CAN BE SAID WITH SOME CONFIDENCE IS THAT VARIOUS MAINLY
SMALL PRECIP CHANCES WILL EXIST DURING THE LATE WEEK PERIOD...THOUGH
HIGHLY DOUBTING THE AMPLIFIED SOLUTIONS OF THE BOTH THE 21/00Z NAM
AND 20/12Z ECMWF GIVEN THE RAGING PACIFIC "FIREHOSE" JET ENERGY THAT
SHOULD EASILY KEEP THE FLOW PROGRESSIVE. INSTEAD WE APPEAR TO BE
LEFT WITH A MYRIAD OF WEAKER UPPER WAVES THAT WILL TRAVERSE A
BRIEFLY STATIONARY TIGHT THERMAL GRADIENT RESIDING OVER THE SOUTHERN
GREAT LAKES. AS SUCH...PRECIP CHANCES SHOULD BE GREATEST OVER
SOUTHERN COUNTIES...AND ENTIRELY POSSIBLE THAT NOT A WHOLE LOT
HAPPENS NORTH OF M-72. STILL...GIVEN PLENTY OF UNCERTAINTY...WILL
MAINTAIN SMALL CHANCE POPS PRETTY MUCH AREAWIDE...THOUGH WILL REMOVE
PRECIP MENTION NORTH OF M-72 ON THURSDAY. WILL ALSO KEEP PRECIP TYPE
AS ALL SNOW AT THIS POINT...THOUGH SOME HINTS EXIST THAT A RAIN/SNOW
MIX IS POSSIBLE ACROSS SOUTHERN AREAS ON THURSDAY AS STRONGER
SHORTWAVE ARRIVES. TEMPS BASICALLY TO CONTINUE ABOVE NORMAL THROUGH
THE PERIOD...MAINLY DRIVEN BY MILD OVERNIGHT LOWS.
LATER PERIODS (FRIDAY NIGHT THROUGH MONDAY)...POTENTIALLY MORE
ACTIVE WEATHER PATTERN STILL APPEARS IN THE WORKS HEADING INTO LATE
WEEKEND...AND MORE LIKELY THE FIRST HALF OF NEXT WEEK...WITH
INCREASING SIGNS OF STRONG NORTH PACIFIC JET COLLAPSING INTO SOME
DEGREE OF WESTERN CONUS TROUGHING. THIS SHOULD HAVE THE NEXT EFFECT
OF SLOWING DOWN THE WAVE TRAIN THROUGH THE CONUS...ALLOWING MORE
TIME FOR AMPLIFICATION OF VARIOUS FEATURES...AND PERHAPS SETTING UP
A SOUTHWEST FLOW REGIME FOR A TIME FROM LATER SUNDAY THROUGH MIDWEEK
(SOMETHING NOT SEEN AT ALL THIS WINTER BUT MUCH MORE TYPICAL OF A LA
NINA EPISODE). CONFIDENCE WITH ANY PARTICULAR PIECE OF GUIDANCE IS
VERY LOW...BUT THE FLAVOR OF THE FORECAST WILL REMAIN INTACT...
FEATURING INCREASING CHANCES FOR SNOW THROUGH MONDAY. AT THIS
JUNCTURE...TEMPS LOOK TO AVERAGE ABOUT NORMAL...THOUGH BIG BUST
POTENTIAL IS THERE LATE IN THE PERIOD SHOULD ANY SYSTEM AMPLIFY
SIGNIFICANT TO OUR WEST (WHICH WOULD HELP DRAG UP SOME QUITE WARM
AIR THIS WAY).
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 642 AM EST TUE FEB 21 2012
VFR CONDITIONS CONTINUE AT EACH OF THE TAF SITES...BUT
DETERIORATING CONDITIONS ARE EXPECTED AS AXIS OF LOW PRESSURE
SHIFTS TOWARDS THE AREA FROM THE SOUTHWEST...BRINGING A ROUND OF
SNOW...WHICH MAY BE MIXED WITH RAIN.
EXPECT MVFR-IFR CIGS/VSBYS IN LIGHT SNOW TO ARRIVE AT MBL/TVC LATE
THIS MORNING...AND PLN/APN THIS AFTERNOON. AT THIS TIME...EXPECT
PRECIPITATION TO BE QUITE LIGHT...WITH VSBYS LIKELY HAVING TROUBLE
REMAINING IFR FOR MORE THAN A FEW HOURS. ALSO...SOME RAIN MAY MIX
WITH THE SNOW AT TIMES AT MBL/TVC. THIS EVENING...AS THE INITIAL
BATCH OF PRECIPITATION SHIFT NORTH AND EAST...EXPECT RESIDUAL LAKE
ENHANCED SHSN THROUGH THE OVERNIGHT AT APN/PLN...WITH MVFR
CONDITIONS /PERHAPS IFR VSBYS AT PLN?/ PERSISTING THROUGH 12Z
WEDNESDAY. MORE IMPROVEMENT IS EXPECTED AT TVC...AND EXPECIALLY
MBL WHERE A RETURN TO VFR CIGS IS EXPECTED AFTER MIDNIGHT.
AS FOR WINDS...LLWS CONCERNS ARE ENDING AT THIS HOUR AS MIXING
STRENGTHENS AT LOW LEVELS. EXPECT SOUTHEAST WINDS 5-10KTS TO VEER
SOUTHERLY 5-10KTS DURING THE DAY TODAY...BEFORE SHIFTING SOUTHWEST
AND INCREASING TO 12G18KTS TONIGHT.
&&
.MARINE...
ISSUED AT 333 AM EST TUE FEB 21 2012
SMALL CRAFTS ONGOING OVER ALL NEARSHORE ZONES...AND EXPECT THIS TO
CONTINUE THROUGH AT LEAST WEDNESDAY AS LOW PRESSURE TAKING SHAPE
OVER NORTHERN MINNESOTA TODAY SHIFTS OVER LAKE SUPERIOR TONIGHT WITH
SOUTHEAST WINDS SHIFTING SOUTHWEST TONIGHT. WINDS/WAVES SHOULD
SUBSIDE WEDNESDAY NIGHT AND THURSDAY AS WEAK AREA OF HIGH PRESSURE
BUILDS IN FROM THE NORTHWEST. AS THE WINDS SHIFT SOUTHWEST
TONIGHT...CAN/T COMPLETELY RULE OUT A FEW LOW-END GALES ON THE
NORTHWEST LAKE MICHIGAN COAST...BUT FLOW TRAJECTORY DOES NOT FAVOR
MUCH IN THE WAY OF COASTAL CONVERGENCE ENHANCEMENT...SO EXPECT MOST
SPOTS TO GUST TO AROUND 30KTS.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 6 PM EST WEDNESDAY FOR LHZ346-349.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EST WEDNESDAY FOR LMZ323-341-342-
344-345-346.
LS...NONE.
&&
$$
UPDATE...ARNOTT
SYNOPSIS...LAWRENCE
SHORT TERM...ARNOTT
LONG TERM....LAWRENCE
AVIATION...ARNOTT
MARINE...ARNOTT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1224 AM EST TUE FEB 21 2012
.UPDATE...
ISSUED AT 946 PM EST MON FEB 20 2012
MAIN CONCERN OVERNIGHT INTO TUE IS ONSET OF -SN. WATER VAPOR IMAGERY
SHOWS A VIGOROUS SRN SHORTWAVE OVER ERN KS. THIS WAVE IS OUT OF
PHASE WITH THE NRN STREAM TROF OVER SASKATCHEWAN AND THE WRN
DAKATOS. WITH VIGOROUS SRN SHORTWAVE WRAPPING UP AND HEADING MORE
E THAN NE...WOULD EXPECT CURRENT STRONG SOUTHERLY FLOW AND
AGGRESSIVE NORTHWARD PUSH OF MOISTURE/PCPN INTO THE UPPER
MISSISSIPPI VALLEY TO DIMINISH WITH TIME AS THE OUT OF PHASE WAVES
SHIFT E OVERNIGHT INTO TUE. THIS WOULD ALLOW VERY DRY AIRMASS AT THE
LOWER LEVELS PER REGIONAL 00Z SOUNDINGS TO HAVE AN INCREASING
INFLUENCE ON SLOWING/ERODING FRONT EDGE OF PCPN AS IT TRANSLATES
EASTWARD...ESPECIALLY SINCE EASTERLY COMPONENT TO LOW-LEVEL WINDS
WILL HELP MAINTAIN A FEED OF DRY AIR. INHERITED FCST APPEARED TO
HAVE A GOOD HANDLE ON THIS IDEA...SO ONLY MINOR FCST CHANGES HAVE
BEEN MADE TO OVERALL TIMING OF -SN OVERNIGHT INTO TUE. SNOW
ACCUMULATIONS THRU TUE WILL BE ON THE LIGHT SIDE DUE TO SPLIT ENERGY
AND DUE TO ANTECEDANT DRY AIRMASS DELAYING ONSET OF SNOW AT THE SFC.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 346 PM EST MON FEB 20 2012
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG OVER THE
GREAT LKS BTWN TROF IN SE CAN AND ANOTHER IN THE PLAINS. AT THE
SFC...UPR MI LIES UNDER A SHARPENING PRES GRADIENT BTWN SFC HI PRES
OVER OH AND LOWER PRES IN THE PLAINS UNDER THE TROF. ALTHOUGH HI
CLDS ARE STREAMING OVHD IN THE SW FLOW ALF...12Z RAOBS TO THE S AT
GRB/MPX/AND QUAD CITIES IA SHOW DRY LO/MID LVLS. SINCE THE SUN IS
JUST FILTERED A BIT BY THESE HI CLDS...TEMPS HAVE REBOUNDED TO WELL
ABV NORMAL LVLS AGAIN AND WELL INTO THE 30S AT MOST SPOTS EARLY THIS
AFTN. ALTHOUGH THERE A LARGER SCALE TROF IN THE PLAINS...SEVERAL OUT
OF PHASE SHRTWVS ARE PRESENT WITHIN THE BROADER AREA OF LOWER HGTS.
THE STRONGEST OF THESE IS OVER THE SCNTRL PLAINS...WITH ANOTHER OVER
SASKATCHEWAN.
MAIN FCST CONCERNS THRU TUE REVOLVE ARND PCPN CHCS TNGT/TUE RELATED
TO EWD PROGRESSION OF PLAINS TROF AND EMBEDDED SHRTWVS. RECENT MODEL
RUNS ARE IN FAIRLY GOOD AGREEMENT SHOWING SHRTWVS/ASSOCIATED SFC LO
CENTERS REMAINING OUT OF PHASE THRU TUE...WHICH WILL LIMIT PCPN
TOTALS OVER THE CWA. IN GENERAL...FOLLOWED THE GFS FOR FCST DETAILS
AT THIS MODEL SHOWS MORE PERSISTENT LLVL DRY AIR WITH MORE MSTR TIED
TO THE STRONGER SRN DISTURBANCE FCST TO TRACK THRU THE LOWER LKS.
TNGT...SHRTWV OVER SASKATCHEWAN IS FCST TO DIG TOWARD MN BY 12Z
WHILE SRN DISTURBANCE MOVES INTO ILLINOIS. PREFERRED GFS SHOWS MORE
IMPRESSIVE QVECTOR CNVGC TENDING TO REMAIN TO THE W AND S OF THE FA.
SINCE SLOWLY BACKING WINDS FM THE SSW TOWARD THE SE WL MAINTAIN LLVL
DRY AIR FEED...PREFERRED GFS MODEL INDICATES PERSISTENT DRY WEDGE IN
THE LLVLS PERSISTING THRU 12Z OVER UPR MI. SO EXCEPT FOR WRN LK
SUP...WHICH WL BE CLOSEST TO INCOMING DYNAMICS ASSOCIATED WITH THE
NRN DISTURBANCE...TENDED TO CUT POPS OVER THE CWA. DESPITE LINGERING
DRY AIR IN THE LLVLS...A STRONGER SW FLOW AND THICKENING HI CLDS WL
PREVENT TEMPS FM FALLING AS SHARPLY AS THE LAST FEW NIGHTS.
TUE...WHILE SRN SHRTWV MOVES ENEWD WELL S OF THE FA...THE NRN
DISTURBANCE IS FCST TO DRIFT EWD INTO THE UPR LKS. WITH INCRSG DPVA/
LLVL MOISTENING/LARGE SCALE QVECTOR CNVGC/SOME UPR DVGC...EXPECT
INCRSG POPS TOWARD CATEGORICAL IN THE AFTN. HOWEVER...SINCE MOST OF
THE DYNAMICS WL BE SPENT SATURATING THE INITIALLY DRY LO/MID LVLS...
PCPN AMNTS WL BE RELATIVELY LGT AND UNDER 0.25 INCH. ALTHOUGH MAX
TEMPS WL TOP OUT OVER 32 ALMOST EVERYWHERE...DYNAMIC/WBLB COOLING
SHOULD KEEP PCPN IN THE FORM OF SN PER GFS FCST SNDGS AND H100-85
THKNS/WBZ HGT BLO CRITICAL LVLS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 346 PM EST MON FEB 20 2012
THE SLOW MOVING 500MB LOW OVER CENTRAL SASKATCHEWAN THIS AFTERNOON
WILL BE OVER N MN/W LAKE SUPERIOR AT 00Z WEDNESDAY...SETTING US UP
FOR AN ACTIVE PERIOD OF LIGHT SNOW SHOWERS.
EXPECT THE 500MB LOW TO BE DIRECTLY OVER UPPER MI AT 06Z
WEDNESDAY...WITH THE 20/06Z GFS SHOWING MORE OF AN OPEN WAVE INSTEAD
OF A CLOSED LOW. THE RESULT IS A MORE PROGRESSIVE /THAN THE
CONSENSUS AND ITS 20/00Z RUN/. EVEN AT THE SFC THE LOW IS QUITE A
BIT FARTHER TO THE SOUTH...BUT WITHIN REASON. ANOTHER DISCREPANCY
WOULD BE FROM THE 20/06Z NAM...WITH IS ON THE SLOW SIDE NEARLY RIGHT
OFF THE BAT. THE DIFFERENCE BETWEEN THE PLACEMENT OF THE FASTER GFS
AND SLOWER NAM IS ROUGHLY 240MI. EXPECT THE ELONGATED TO DOUBLE
BARREL SFC LOW STRETCHING FROM N MN TO SE IA AT 12Z TUESDAY TO
DEEPEN ACROSS E LAKE SUPERIOR TUESDAY NIGHT...BEFORE SLIDING ALMOST
DIRECTLY E INTO S QUEBEC LATE TUESDAY NIGHT INTO WEDNESDAY. WHILE A
SFC TROUGH WILL LINGER BEHIND THE EXITING LOW...IT WILL BE OF SHORT
DURATION...AS A SFC RIDGE QUICKLY BUILDS IN WEDNESDAY AFTERNOON
AHEAD OF THE NEXT LOW. ANOTHER HINDRANCE TO HEAVY SNOW WILL BE THE
RELATIVELY MILD 850MB TEMPS NEAR -8C...AND PREDOMINANT WNW WINDS
BEHIND THE SFC LOW. WHILE LAKE ENHANCEMENT WILL BE POSSIBLE AS THE
LOW MOVES OVERHEAD...SHIFTING WINDS WILL DETER SIGNIFICANT AMOUNTS.
THE BEST CHANCE OF RECEIVING 2-5 INCHES WOULD BE FROM IWD TO
CMX.
THE NEXT 500MB FEATURE OF IMPORTANCE WILL BE IN THE FORM OF A S
CENTRAL CANADIAN TROUGH WEDNESDAY NIGHT...SLIDING ACROSS THE UPPER
GREAT LAKES THURSDAY AFTERNOON. THE CONSENSUS IS TO HAVE THIS TROUGH
DEEPEN INTO A LOW UPPER MI FRIDAY...BEFORE MOVING INTO S QUEBEC
FRIDAY NIGHT. WHILE THE ORIGINS OF THE SFC LOW...OVER SASKATCHEWAN
WEDNESDAY AFTERNOON WOULD INDICATE ANOTHER LOW WITH LITTLE IN THE
WAY OF MOISTURE TO WORK WITH...ITS PROGRESSION WILL ALLOW THE GULF
TO OPEN UP. EXPECT THE SFC LOW TO RESIDE BETWEEN CENTRAL WI/CENTRAL
LOWER MI/CENTRAL UPPER MI AT 18Z THURSDAY /WITH THE ECMWF FARTHER
SOUTH THAN THIS/...AND A COLD FRONT DRAGGING ACROSS IL/MO/AND INTO
NE TX. THE SFC LOW SHOULD DEEPEN AS IT SLIDES EAST OF OUR
AREA...THURSDAY NIGHT NEAR THE LOWER GREAT LAKES...AND FRIDAY
AFTERNOON/EVENING OVER S QUEBEC. AS THE SYSTEM DEEPENS AND TAPS INTO
ADDITIONAL MOISTURE OFF THE ATLANTIC IT SHOULD WRAP IN STEADY N
WINDS SLOWLY BECOMING NW...AND PLENTY OF COLD AIR TO OUR REGION
FRIDAY AFTERNOON THROUGH SATURDAY NIGHT. 850MB TEMPS AT THIS POINT
THE PRESSURE GRADIENT BECOMES FAIRLY WEEK WITH A SFC RIDGE NEARLY
OVERHEAD.
PRECIPITATION TYPE MAY BE A CONCERN FOR THIS SYSTEM OVER THE SE
CORNER OF THE CWA RIGHT ALONG LAKE MICHIGAN. 850MB TEMPS OF THE
20/06Z GFS ARE AROUND -4C...WITH THE MNM SOUNDING SHOWING
INDICATIONS OF RA FROM MID MORNING THROUGH THE REMAINDER OF THE
DAYTIME HOURS THURSDAY. THE EVEN WARMER/MORE WRAPPED UP 20/00Z
CANADIAN WOULD HAVE 850MB TEMPS AROUND -2C OVER THE ENTIRE CWA
AROUND 12Z THURSDAY...LINGERING EAST AS THE LOW EXITS EARLY THURSDAY
EVENING. WILL NOT CONCENTRATE TOO MUCH ON THIS...AS THERE ARE LARGER
DISCREPANCIES...WITH THE NAM AND ECMWF NOT TOO ENTHUSED ABOUT THE
NORTHERN EXTENT OF THE SYSTEM...WITH THE BULK OF THE MOISTURE
REMAINING OVER IL/IN/OH. BOTH THE GFS AND ECMWF SHOW GOOD RUN TO RUN
CONSISTENCY...WITH A BLEND LOOKING REASONABLE AT THIS TIME. THE 12Z
RUNS OF THE GFS AND ECMWF KEPT WITH A MORE SOUTHERLY SOLUTION FOR
THIS SYSTEM...CLOSER TO THE 00Z RUN OF THE ECMWF. THIS TREND WOULD
CONTINUE TO LIMIT THE MENTION OF RAIN NEAR LAKE MICHIGAN. NO MATTER
WHICH SOLUTION OR GROUP OF SOLUTIONS IS PREFERRED...850MB TEMPS
SHOULD FALL BETWEEN -12 AND -16C FROM FRIDAY NIGHT ON...WITH
FAVORABLE WINDS OFF LAKE SUPERIOR PRODUCING LIGHT TO MODERATE SNOW
SHOWERS.
BEYOND FRIDAY NIGHT THE 20/06Z GFS AND 20/00Z ECMWF BECOME OUT OF
PHASE. THIS IS BEST INDICATED BY THE LATE SATURDAY AFTERNOON/SUNDAY
NIGHT TRENDS AT 500MB OVER THE GREAT LAKES...WITH THE ECMWF
INDICATING A RIDGE AND THE GFS A TROUGH. THIS IS MAINLY DUE TO THE
HANDLING OF THE LOW EJECTING E SATURDAY. THE ECMWF IS ON THE QUICKER
SIDE...WHILE THE LAST 2 GFS RUNS CONTINUE TO DEEPEN THE LOW AS IT
SHIFTS INTO FAR EASTERN CANADA. AS A RESULT...WILL NOT TRY TO PIN
POINT SPECIFICS BEYOND SATURDAY NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1224 AM EST TUE FEB 21 2012
LLWS WILL REMAIN IN THE FCST AT KCMX/KSAW FOR THE NEXT FEW HRS AS
KMQT VAD WIND PROFILE INDICATES 35KT S WIND AT 500FT AGL. EXCEPTION
IS AT KIWD AS SFC WINDS HAVE REMAINED GUSTY THERE. ATTENTION THEN
TURNS TO APPROACHING LOW PRES TROF. LOW-LEVEL DRY AIR WILL CONTINUE
TO SLOW EASTWARD PROGRESS OF -SN IN NW WI...BUT WEAK LEAD SHORTWAVE
LIFTING THRU SE MN INTO FA NW WI MAY BE SUFFICIENT TO BRING A PERIOD
OF -SN/MVFR CONDITIONS TO KIWD AND POSSIBLY KCMX OVERNIGHT.
OTHERWISE...MVFR CONDITIONS PROBABLY WON`T DEVELOP UNTIL LATE
MORNING AS MIDLEVEL TROF MOVES CLOSER. CONDITIONS MAY DROP TO IFR IN
THE AFTN/EVENING AS LOW-LEVELS SATURATE. FOR NOW...ONLY OPTED FOR
IFR AT KCMX AFTER COLD FRONT PASSES IN THE EVENING AND WINDS SHIFT
TO AN UPSLOPE WESTERLY DIRECTION.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 346 PM EST MON FEB 20 2012
WITH AN UNSEASONABLY WEAK PRES GRADIENT FORECAST THIS WEEK...EXPECT
WINDS NO HIER THAN 25 KTS. NO GALES ARE FORECAST IN THE NEAR FUTURE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...ROLFSON
SHORT TERM...KC
LONG TERM...KF
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
522 PM CST WED FEB 22 2012
UPDATED TO INCLUDE THE 00Z AVIATION DISCUSSION
.DISCUSSION...
SUMMARY...QUITE THE DAY HERE AT THE NWS OFFICE TODAY. THREE
POTENTIAL SNOW STORMS IN THE FORECAST AREA OVER THE NEXT 160 HOURS
AND PLENTY OF MODEL DISAGREEMENT TO GO ALONG WITH IT.
FIRST THINGS FIRST...SHORTWAVE PASSING THROUGH THIS AFTERNOON
YIELDING ISOLATED TO SCATTERED LIGHT SNOW SHOWERS...SHOULD BE
THROUGH EARLY THIS EVENING AND LOOKS DRY FOR SEVERAL HOURS BEFORE
THE SURFACE LOW FROM THE NORTHWEST. LOOK OF POTENTIAL WITH THIS
STORM FOR TONIGHT...BUT THE QUESTION TODAY HAS NOT BEEN IF THERE
WILL BE A 6+" SNOWBAND...BUT WHERE. IN GENERAL...THERE HAS BEEN
TWO CLUSTERS OF MODEL GUIDANCE: THE UKMET/EC IN ONE CAMP AND THE
GFS/GEM/SREF/ IN THE OTHER. THE 12Z NAM WAS AN OUTLIER TO THE
NORTH AND BROUGHT THE HEAVY SNOW ACROSS CENTRAL MN...INCLUDING THE
TWIN CITIES METRO. THE 18Z NAM JOINED THE GFS/SREF/GEM CAMP AND
CAME IN MUCH FURTHER SOUTH. DEBATED ON UPGRADING THE WATCH TO A
COMBINATION OF WARNING/ADVISORY WITH THE HEAVIEST ACCUMULATIONS IN
MARTIN AND FARIBAULT COUNTIES. IN FACT...EVEN HAD THE WARNING
DRAWN UP LATE THIS AFTERNOON...BUT THE LAST FRAME OF THE HRRR
AGREES QUITE WELL WITH THE ECMWF AND WOULD KEEP ALMOST ALL OF THE
SNOW OUT OF THE FORECAST AREA.
THERE IS ALREADY A LIGHTNING STRIKE UPSTREAM IN MONTANA THIS
AFTERNOON...WHICH IS USUALLY A PRETTY GOOD INDICATOR OF THE
STRENGTH OF THIS SYSTEM. NO SURPRISE WITH 992-993MB SURFACE LOW
DROPPING SOUTH ACROSS WESTERN IA BASED ON THE NAM/GFS...THERE IS
VERY GOOD 800-600MB FGEN TO GO ALONG WITH NEGATIVE EPV AND AT
LEAST SOME ELEVATED INSTABILITY-BEST LI APPROACHES THE FORECAST
AREA WITH 2/3 GRAM MIXING RATIOS OFF THE ISENTROPIC SURFACES. THE
FORECAST SIDES WITH THE GFS/GEM/NAM/SREF CLUSTER OF SOLUTIONS.
HOWEVER...LOW CONFIDENCE WITH NOW THE LATEST HRRR AGREEING QUITE
WELL WITH THE ECMWF. IT`S A FEAST OF FAMINE SITUATION-THERE WILL
LIKELY BE 6-10 INCHES...POSSIBLY A FOOT...IN A NARROW CORRIDOR
WHERE THE BEST FORCING SETS UP AND NOT MUCH TO THE NORTH OF IT.
DRAMATICALLY REDUCED POPS AND AMOUNT OF SNOW IN METRO...MIGHT BE
NOTHING AT. USUALLY GOOD SUBSIDENCE ON NORTH SIDE OF THE
DEFORMATION.
IN THE EXTENDED...THE SUNDAY/MONDAY SYSTEM LOOKS POTENT...JUST NOT
SOME MUCH FOR HERE WITH THE SURFACE LOW TRACKING OVERHEAD AND HIGH
POTENTIAL FOR DRY SLOT BASED ON THE ASSORTMENT OF OPERATIONAL RUNS
AND ENSEMBLE GUIDANCE. UNLESS SOMETHING CHANGES...A LOT OF SNOW
AND WIND IN THE DAKOTAS AND NORTHERN MN AND NOT MUCH HERE. GFS
SPITS OUT THE HIGHEST QPF...BUT IT MIGHT BE OVERDONE. THERE ARE
FAIRLY HIGH POPS IN THE FORECAST...BUT OVERALL...DOESN`T LOOK LIKE
ANYTHING MAJOR IN THE IMMEDIATE AREA. THERE`S ANOTHER WHOPPER OFF
THE GFS THIS TIME NEXT...BUT NOT SHOWING UP AS MUCH ON THE ECMWF
AND GFS ENSEMBLE TO SOME DEGREE. THE 12Z GFS HAD A BAND OF 12-18"
IN SOUTHERN MN...SOMETHING THAT WILL LIKELY CHANGE WITH TIME.
&&
.AVIATION.../00Z TAF ISSUANCE/
THE LATEST MODEL RUNS...CONTINUE TO ADVERTISE A WINTER STORM FOR
PORTIONS OF SOUTHERN MN LATER TONIGHT AND THURSDAY. EXPECT A NARROW
BAND OF MODERATE TO HEAVY SNOW TO SETUP OVER THE SOUTHERN TIER
COUNTIES OF MINNESOTA. WEATHER CONDITIONS IN THIS AREA EXPECTED TO
LOWER TO LIFR CATEGORY THURSDAY MORNING THEN IMPROVE TO MVFR
CATEGORY THURSDAY EVENING. ELSEWHERE...OVER THE REMAINDER OF THE TAF
SITES...VFR FLYING CONDITION WILL PREVAIL THROUGH THE BULK OF THE
PERIOD WITH THE EXCEPTION OVER PARTS OF WEST CENTRAL MN...WHERE
CEILINGS ARE EXPECTED TO LOWER BETWEEN 1500-2500 FEET AGL.
KMSP...VFR CONDITIONS PREVAILING THROUGH THURSDAY MORNING. WEATHER
SYSTEM WILL MOVING OUT OF THE NORTHERN ROCKIES...WILL MOVE SOUTHEAST
OVER NORTHERN IOWA. THIS SYSTEM WILL ONLY GRAZE THE SOUTHERN METRO
AREA. SCATTERED SNOW FLURRIES DEVELOPING ON THURSDAY...LITTLE
ACCUMULATION EXPECTED. CEILING BRIEFLY LOWERING AROUND 2500 FEET
AGL.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WATCH FROM 3 AM CST THURSDAY THROUGH THURSDAY
AFTERNOON FOR BLUE EARTH-BROWN-FARIBAULT-FREEBORN-MARTIN-
REDWOOD-STEELE-WASECA-WATONWAN.
WI...NONE.
&&
$$
CLF/JM
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1056 PM CST MON FEB 20 2012
.UPDATE...
ISSUED AT 834 PM CST MON FEB 20 2012
MADE SOME ADJUSTMENTS TO GOING FORECAST TO INCLUDE ISOLATED THUNDERSTORMS
OVER CENTRAL AND SOUTHEAST MISSOURI THIS EVENING...AND ADJUSTED POPS
BASED ON GOING RADAR OBSERVATIONS. LINE OF SHOWERS AND SCATTERED
THUNDERSTORMS ACROSS SOUTHWEST AND WEST CENTRAL MISSOURI THAT
PRODUCED ISOLATED SEVERE WIND GUSTS EARLIER CONTINUES TO MOVES
NORTHEAST THIS EVENING AND WILL LIKELY MOVE INTO CENTRAL AND
NORTHEAST MISSOURI BETWEEN 9-10PM. WHILE THE INTENSITY OF THE
THUNDERSTORMS SHOULD DECREASE AS IT MOVES INTO DRIER
AIR...STRENGTH OF ASCENT WITH NEGATIVELY TILTING UPPER TROUGH AND
DECENT 925-850MB MOISTURE CONVERGENCE SHOULD KEEP THE LINE OF
SHOWERS GOING. RADAR INTERPOLATION AND HRRR FORECAST REFLECTIVITY
SUGGESTS THAT THIS LINE OF SHOWERS WILL CONTINUE TO MOVE EAST AND
LIKELY EXIT THE CWA BY 3 AM. I HAVE ADDED ISOLATED THUNDERSTORMS
TO PARTS OF CENTRAL AND SOUTHEAST MISSOURI THIS EVENING BASED ON
THE STRENGTH OF THE ASCENT AND WEAK INSTABILITY SEEN IN THE RUC.
REST OF THE FORECAST STILL LOOKS GOOD.
BRITT
&&
.SHORT TERM...
ISSUED AT 239 PM CST MON FEB 20 2012
(TONIGHT)
MID AND HIGH CLOUDS MOVING INTO FORECAST AREA THIS AFTERNOON AHEAD
OF NEXT WEATHER SYSTEM. SOME SHOWERS HAVE DEVELOPED OVER WESTERN
MO AHEAD OF COLD FRONT...BUT MAKING VERY LITTLE PROGRESS TO THE
EAST YET UNTIL SHORTWAVE BEGINS TO LIFT OUT. SO BACKED OFF ON ONSET
OF PCPN WITH RAIN MOVING INTO CENTRAL MO BY 01Z...ALONG
MISSISSIPPI RIVER BY 04Z AND EASTERN PORTIONS OF FORECAST AREA BY
06Z. MODELS SHOWING LITTLE IN THE WAY OF INSTABILITY WITH THIS
SYSTEM OVER OUR AREA...SO REMOVED MENTION OF THUNDERSTORMS. ONCE
THIS SYSTEM BEGINS TO MAKE SOME PROGRESS TO THE EAST ONLY EXPECT
IT TO RAIN FOR A FEW HOURS MOST LOCATIONS...WITH ONLY A TENTH OF
AN INCH OF QPF...BEFORE COMING TO AN END TOWARDS DAYBREAK. AS FOR
LOW TEMPS...INITIALLY COLD AIR LAGGING BEHIND THIS SYSTEM...SO
LOWS TO ONLY DIP INTO THE UPPER 30S TO AROUND 40.
BYRD
&&
.LONG TERM...
ISSUED AT 350 PM CST MON FEB 20 2012
(TUESDAY THROUGH NEXT MONDAY)
THE LONGWAVE UPPER LEVEL TROF IS EXPECTED TO STILL SETTLE IN FOR
MUCH OF THE WORK WEEK BEGINNING TUESDAY AND MAINTAINING ITSELF UNTIL
FRIDAY WITH A FEW GENERALLY WEAK SHORTWAVES SWINGING THRU. THIS
WILL SCOOT A FEW FRONTS THRU AT A FRANTIC PACE BUT MOISTURE WILL BE
PRETTY LIMITED DURING THIS TIME ALTHOUGH IT APPEARS UPPER LEVEL
IMPULSE ON THURSDAY SHOULD BE STRONG ENOUGH WITH ENOUGH MOISTURE TO
WARRANT CONTINUED MENTION OF CHANCE POPS. FAIRLY DEEP MIXING
TUESDAY THRU THURSDAY WILL RESULT IN CONTINUED MILD TEMPS FOR LATE
FEBRUARY...WITH WARMEST MOS VALUES FAVORED...RESULTING IN 50S AND
SOME 60S FOR MAXES. AND TUESDAY/S VALUES ARE DESPITE CDFNT MOVING
THRU LATER TONIGHT...AS RESULTANT TEMPS WILL BE NEARLY IDENTICAL...
PERHAPS A TAD HIGHER...THAN PERSISTENCE.
NWLY UPPER LEVEL FLOW COUPLED WITH HI PRES INVOF THE FA WILL RESULT
IN QUIET WX FOR MUCH OF THE UPCOMING WEEKEND...WITH TEMPS REBOUNDING
FROM NEAR AVERAGE ON FRIDAY TO ABOVE AVERAGE AGAIN BY SUNDAY. UPPER
LEVEL FLOW SHIFTS SWLY BY NEXT MONDAY WHERE A STORMIER PATTERN
APPEARS IN THE OFFING.
TES
&&
.AVIATION...
ISSUED AT 1030 PM CST MON FEB 20 2012
A LINE OF SHOWERS MOVING THROUGH COU WILL MOVE NEWD THROUGH THE
REST OF THE TAF SITES DURING THE OVERNIGHT HOURS. THIS ACTIVITY
WAS ASSOCIATED WITH A SFC LOW OVER EXTREME NWRN MO AND A TRAILING
CDFNT S OF THE LOW. THESE SHOWERS SHOULD ONLY LAST A COUPLE OF
HOURS AS THEY MOVE QUICKLY THROUGH THE AREA. CLOUD CEILINGS HAVE
DROPPED INTO THE MVFR CATAGORY IN COU WITH THE RAIN AND SHOULD
ALSO DROP TO AROUND 2500 FT IN THE REST OF THE TAF SITES AS THE
RAIN MOVES IN. THE CIGS SHOULD ALSO LOWER LATE TGT/EARLY TUE MRNG
AFTER FROPA...ALTHOUGH PROBABLY NOT AS LOW AS THE NAM MOS CIG
HEIGHT GUIDANCE. GUSTY SLY SFC WINDS CAN BE EXPECTED ESPECIALLY
WITH THE SHOWER ACTIVITY...WITH THE WIND GRADUALLY VEERING AROUND
TO A SWLY DIRECTION AFTER FROPA AND A WLY DIRECTION TUE MRNG. THE
MVFR CIGS SHOULD SCATTER OUT IN COU EARLY TUE MRNG AND IN THE REST
OF THE TAF SITES LATE TUE MRNG. THE RELATIVELY STRONG AND GUSTY
WLY SFC WINDS WILL DIMINISH TUE EVNG AND BACK AROUND TO A SWLY
DIRECTION.
SPECIFICS FOR KSTL...A LINE OF SHOWERS WILL MOVE THROUGH STL FROM
06-09Z TUE WITH CLOUD CEILINGS LOWERING INTO THE MVFR CATAGORY
AND SELY SFC WINDS BECOMING SLY AND GUSTING UP TO AROUND 30 KTS
WITH THE SHOWERS. THE CEILING MAY RISE BRIEFLY AFTER MOST OF THE
SHOWERS MOVE THROUGH...BUT THEN DROP BACK DOWN TO THE MVFR
CATAGORY AFTER FROPA. THE SFC WIND WILL CONTINUE TO VEER AROUND TO
A SWLY DIRECTION LATE TGT AFTER FROPA...AND THEN A WLY DIRECTION
TUE MRNG. THE MVFR CIG SHOULD SCATTER OUT BY LATE TUE MRNG. THE
STRONG AND GUSTY WLY SFC WIND WILL DIMINISH TUE NGT AND BACK
AROUND TO A SWLY DIRECTION.
GKS
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1122 PM CST MON FEB 20 2012
.AVIATION...
06Z TAFS FOR KOFK...KOMA AND KLNK.
LOW CLOUDS CONTINUED TO CLEAR EASTWARD AND SHOULD WORK EAST OF
OMAHA BY 10-11Z. A PERIOD OF GUSTY NORTHWEST WINDS ARE EXPECTED
BEHIND COLD FRONT BUT THEY SHOULD RELAX AND BACK A LITTLE LATER
TONIGHT TO MORE WESTERLY BEFORE POSSIBLY INCREASING A BIT WITH
MIXING ON TUESDAY. A WEAK DISTURBANCE WILL SPREAD MID/HIGH CLOUDS
ACROSS AREA TUESDAY...ESPECIALLY BY EVENING.
CHERMOK
&&
PREV DISCUSSION... /ISSUED 340 PM CST MON FEB 20 2012/
SHORT TERM...TONIGHT THROUGH THURSDAY.
THE MAIN CONCERNS IN THE SHORT TERM WILL BE THE COVERAGE OF THE
PRECIPITATION THAT RE-DEVELOPS AND PRECIP
TYPE...CONVECTION...RAIN/SNOW MIX.
THE 12Z UPPER AIR CHARTS SHOWED A 110+KT JET OVER NEW MEXICO
ROUNDING THE BASE OF THE TROF. THE H5 LOW WAS OVER NORTHEAST
COLORADO WITH 130M HEIGHT FALLS AT DENVER. THE H7 LOW WAS NEAR KLBF
WITH H7-H5 LAPSE RATES OF 7.5 DEG C/KM AHEAD OF THE H7 LOW. THE H85
LOW WAS NEARLY VERTICALLY STACKED BTWN RAPID CITY AND NORTH PLATTE.
BOTH DDC AND OMA REPORTED 50KT H85 WINDS. AT MIDDAY...THE SURFACE
MAP HAD SFC LOW PRESSURE NEAR LEXINGTON AND PER THE VISIBLE
STLT...THERE WAS NOTICEABLE CLEARING JUST AHEAD OF THE SFC LOW. SFC
TEMPERATURES RANGED FROM THE MID 30S IN THE NORTH TO THE MID AND
UPPER 40S TOWARD FAIRBURY AND FALLS CITY. THE WSR-88D RADAR MOSAIC
LOOP FROM THIS MORNING AND METARS SHOWED THAT TEMPERATURES WARMED
ABOVE FREEZING...HOWEVER SNOW AND SLEET DID MOVE ACROSS THE NORFOLK
AND WAYNE AREAS WITH VSBYS DOWN TO 2SM. 6HR PRECIPITATION
AMOUNTS THROUGH 18Z WERE LIGHT...GENERALLY .15 OR LESS. THERE WERE
A FEW LIGHTNING STROKES NEAR BVN/OLU/OFK. BY 19Z...THE BULK OF THE
PRECIPITATION HAD SHIFTED NORTH AND EAST OUT OF EASTERN
NEBRASKA...WITH THE NORTH TO SOUTH BAND ACROSS WRN IOWA. OUTSIDE OF
OUR AREA...WEST OF THE SURFACE LOW IN WESTERN NEBRASKA...SNOW WAS
FALLING...MODERATE TO HEAVY AT TIMES FROM VALENTINE TO IMPERIAL.
AT 21Z...A NARROW LINE OF CONVECTION WAS DEVELOPING ACROSS CENTRAL
KANSAS...WITH A FEW WARNINGS BEING ISSUED. THIS CONVECTION IS
PROGRESSING NORTH AND EAST. AT 00Z THE THETA-E AXIS IS PROGGED TO
STRETCH FROM ERN NEB INTO ERN KANSAS AND ZERO OR LOWER BEST
LIFTED INDEX VALUES ARE OVER THE NEB/KS BORDER AHEAD OF THE SFC
LOW. THE LATEST HRRR TENDS TO TAKE THE BETTER CONVECTION SOUTH OF
THE FORECAST AREA...HOWEVER...DID INCLUDE THUNDERSTORM MENTION
OVER THE SOUTHEAST NEB WITH DRIZZLE OR LIGHT RAIN FARTHER
NORTH...AND A MIX OF RAIN/SNOW MOVING EAST DURING THE EVENING.
THE RUC AND 18Z NAM SHOW THE BAND OF SNOW WEAKENING AS IT MOVES
INTO THE FORECAST AREA...HOWEVER THERE MAY BE ENOUGH
OMEGA/FRONTOGENESIS/DEPTH OF COLD AIR TO SWITCH IT OVER TO LIGHT
SNOW. DID INCLUDE SOME MINOR SNOW AMOUNTS IN PARTS OF ECNTRL/NE
NEB TO ACCOUNT FOR THIS. TREND AFTER 06Z IS FOR THE SYSTEM TO BE
MOVING OUT...WITH WESTERLY FLOW FOR TUESDAY.
LATE TUESDAY NIGHT INTO WEDNESDAY NIGHT...NORTHWEST FLOW ALOFT
WILL BRING MODERATE TEMPERATURES AND VARIABLE CLOUDS. THE MODELS
HAVE SOME DIFFERENCES ON THE CHC FOR PRECIPITATION DURING THIS
PERIOD. FOR NOW INCLUDED SOME SPRINKLES WEDNESDAY AND WITH THE
COLDER AIR WEDNESDAY NIGHT AND THURSDAY...A RAIN SNOW MIX IN THE
NORTH.
ZAPOTOCNY
LONG TERM...THURSDAY NIGHT THROUGH MONDAY.THE LONG TERM PERIOD
WILL BEGIN WITH AN UPPER TROUGH OVER THE GREAT LAKES AND THE
EASTERN NORTHERN PLAINS. A SHORTWAVE SHOULD BE EXITING OUR AREA
THURSDAY NIGHT SO WILL MAINTAIN A DRY FORECAST THEN. ANOTHER
SHORTWAVE LOOKS TO DROP THROUGH THE NORTHWEST FLOW ON BACK SIDE OF
UPPER TROUGH ON FRIDAY...WITH MODELS SHOWING VARYING DEGREES OF
INTENSITY AND LOCATION. GFS IS THE STRONGEST AND FARTHEST
WEST...WHICH WOULD BRING A CHANCE FOR LIGHT SNOW TO OUR
AREA...WHILE ECMWF/CANADIAN TRACK SHORTWAVE TO OUR EAST. WILL STAY
WITH MAJORITY OF MODEL SOLUTIONS WHICH MATCH OUR CURRENT DRY
FORECAST. HOWEVER ALL SOLUTIONS SUGGEST A RATHER CHILLY DAY FRIDAY
AS AT LEAST MODERATE COLD ADVECTION SHOULD KEEP HIGHS IN THE 30S.
A WARMING TREND STILL LOOKS ON TAP FOR THE WEEKEND AS UPPER FLOW
BECOMES MORE ZONAL IN WAKE OF EXITING UPPER TROUGH AND AHEAD OF
LOWERING HEIGHTS ALONG THE WEST COAST. AGAIN TODAY MODELS HAVE
DIFFERING OPINIONS ON TIMING AND EXTENT OF WARMING BASED ON
DIFFERING UPPER FLOW SOLUTIONS. FOR THE MOST PART...ALL MODELS SHOW
LOWERING HEIGHTS IN THE WEST...BUT SOME ARE HINTING AT A SIGNIFICANT
PIECE OF ENERGY MOVING FROM THE ROCKIES ACROSS THE PLAINS ON SUNDAY.
GFS IS THE MOST BULLISH IN THIS REGARD...AND HAS NOT WAVERED FROM
RUN TO RUN. HOWEVER...GFS ENSEMBLE MEMBERS ARE SPLIT...WITH A
PLURALITY LEANING TOWARD A 00Z ECMWF SOLUTION KEEPING MORE ENERGY
DROPPING INTO THE SOUTHWEST STATES AND MAINTAINING ZONAL OR
SOUTHWEST FLOW ALOFT IN THE PLAINS THROUGH SUNDAY. THE NEW 12Z ECMWF
MAINTAINS THIS PHILOSOPHY...SO HAVE SIDED WITH THIS THOUGHT FOR THE
WEEKEND.
USING ECMWF...HIGHS SATURDAY SHOULD REBOUND BACK INTO THE
40S BUT SUNDAY IS STILL IN QUESTION. BAROCLINIC ZONE LOOKS TO SET UP
NORTH TO SOUTH ACROSS OUR CWA WITH THE 0C 850 LINE NEAR INTERSTATE
80. STRONG ISENTROPIC UPGLIDE WILL COMMENCE SUNDAY AFTERNOON UNDER
COUPLED JET STRUCTURE...SUGGESTING LIFT OVER BAROCLINIC ZONE COULD
LEAD TO PRECIPITATION IN OUR NORTH. THICKNESSES SUPPORT SNOW
THERE...BUT WARM LOW LEVEL TEMPS COULD CHANGE THAT TO RAIN. SO A MIX
OF PRECIP WILL BE ADDED TO FORECAST SUNDAY. CLOUDS AND
PRECIPITATION CHANCES WILL LIKELY LIMIT HIGHS TO THE 30S IN OUR
NORTH. THIS TREND CONTINUES INTO MONDAY AS SURFACE LOW TRACKS TO OUR
SOUTH...MAINTAINING BAROCLINICITY ACROSS OUR AREA WITH A NORTHWEST
TO SOUTHEAST ORIENTATION. TRACK OF LOW PUTS OUR SOUTHEAST CWA IN
FAVORABLE AREA FOR RAIN THEN...WITH HIGHS RANGING FROM THE 20S OR
LOWER 30S NORTHWEST TO THE UPPER 30S SOUTHEAST. THERE IS A LOT OF
ROOM FOR ERROR SUNDAY AND MONDAY GIVEN PROXIMITY OF BAROCLINIC
ZONE...SO RELATIVELY LOW CONFIDENCE FORECAST AT THIS TIME.
DERGAN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
99/99
AREA FORECAST DISCUSSION
NWS RALEIGH NC
112 PM EST TUE FEB 21 2012
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OUT INTO THE WESTERN ATLANTIC. A SERIES OF
UPPER LEVEL DISTURBANCES WILL MOVE THROUGH THE AREA THROUGH
WEDNESDAY...FOLLOWED BY A STRONG COLD FRONT PASSAGE ON FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1025 AM...
LATEST RUC MODEL SHOWS THICKNESSES INCREASING LATE AFTERNOON INTO
EVENING WITH THIS ENERGY REMAINING ALOFT. IT IS PRUDENT TO BACK
OFF THE 00Z THICKNESS VALUES REGARDING TEMPERATURE FORECASTS DUE
TO THIS TIMING AND ENERGY REMAINING ALOFT. MID LEVEL CLOUDINESS HAS
ARRIVED ON CUE INTO CENTRAL NORTH CAROLINA. THE CLEARING LINE
SHOULD PASS THE WESTERN PIEDMONT BEFORE NOON... EXITING TO THE
COASTAL PLAIN AT MID AFTERNOON. HOWEVER A LOOK AT UPSTREAM
TRAJECTORIES AND MOISTURE SUGGEST SOME CLOUDINESS BEHIND THE
CLEARING LINE... BUT NOT AS EXTENSIVE AS THIS MORNING. CURRENT
FORECAST OF MID TO UPPER 50S PERHAPS A TOUCH COOL... BUT THIS WILL
DEPEND ON AFTERNOON CLOUD COVER.
LOOKING AT CURRENT TEMPERATURE PROFILES AND SURFACE TEMPERATURE
FORECASTS... WIND GUSTS TO 20 MPH SHOULD HOLD OFF UNTIL EARLY
AFTERNOON.
THE QUESTION OF POSSIBLE VERY LOW STRATUS TONIGHT WILL BE THE
PROBLEM OF THE DAY... BUT WILL DELAY ANY CHANGES UNTIL ALL THE
MORNING MODELS ARE PROCESSED. ALTHOUGH SUBTLE... DECENT LOW LEVEL
ADVECTION IN THE MODELS WITH THE STRONGER WINDS OF THE NAM ATOP
THE BOUNDARY LAYER INVERSION WITH DECOUPLING MORE REALISTIC THAN
THE GFS. TEND TO FAVOR A FORECAST OF STRATUS FORMATION BUT
UNCERTAIN OF EXTENT AT THIS TIME. REGARDLESS TEMPERATURES WILL BE
MILD COMPARED TO THIS MORNING... WITH UPPER 30S TOO LOWER 40S
COMMON.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 250 AM TUESDAY...
BY WEDNESDAY A BROAD SCALE TROUGH WILL HAVE EVOLVED OVER THE
EASTERN TWO THIRDS OF THE COUNTRY WITH SEVERAL EMBEDDED FAST
MOVING PERTURBATIONS MOVING EAST ACROSS THE AREA IN THE
PROGRESSIVE ZONAL FLOW ALOFT. ONE OF THESE VORTICITY IMPULSES OF
NOTE IS FORECAST TO REACH THE SOUTHERN AND CENTRAL APPALACHIANS
AROUND 00Z THURSDAY...AND WILL THEN TRAVERSE THE CAROLINAS BY 06Z.
DPVA AND DYNAMIC COOLING/ASCENT ACCOMPANYING THE TROUGH PASSAGE
WILL STEEPEN MID AND UPPER LEVEL LAPSE RATES ACROSS THE AREA
WEDNESDAY EVENING AND ELIMINATE THE MID LEVEL CAP...WHICH SHOULD
ALLOW THE BAND OF SHOWERS TO SURVIVE EASTWARD AS THEY MOVE OFF THE
EASTERN SLOPES AND ACROSS THE AREA. UNFAVORABLE NOCTURNAL
TURNING/BOUNDARY LAYER STABILIZATION WILL IMPACT COVERAGE
HOWEVER...AND AT THIS TIME WILL CAP POPS OFF AT LOW TO SLIGHT
CHANCE...WITH HIGHEST POPS OVER THE WESTERN PIEDMONT AND ENDING
BEFORE DAYBREAK THURSDAY.
WILL SEE FULL COMPLIMENTS OF SUN ON WEDNESDAY AS THICKNESSES SOAR TO
AROUND 1350 METERS...A GOOD 20 TO 25 METERS ABOVE NORMAL. HIGHS IN
THE LOWER 60S NORTHWEST TO UPPER 60S SOUTHEAST. MILD OVERNIGHT
LOWS OF 46 TO 51.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 300 AM TUESDAY...
MODELS HAVE COME INTO BETTER AGREEMENT OVER THE PAST 24 HOURS WITH
RESPECT TO OUR NEXT SYSTEM THAT IS EXPECTED TO IMPACT THE REGION
DURING THE FIRST PART OF THE LONG TERM PERIOD. MODELS SHOW ANOTHER
SOUTHERN STREAM UPPER LEVEL TROUGH/LOW DIGGING INTO THE SOUTHWESTERN
UNITED STATES AND NORTHERN MEXICO TUESDAY INTO WEDNESDAY AND
EVENTUALLY EJECTING EASTWARD AND AFFECTING CENTRAL NORTH CAROLINA
THURSDAY INTO FRIDAY. DURING THE SAME TIME FRAME...A NORTHERN
STREAM TROUGH WILL AMPLIFY AS IT MOVES INTO THE CENTRAL UNITED
STATES...PROMOTING SURFACE CYCLOGENESIS ACROSS THE TENNESSEE AND
OHIO VALLEY. THE ASSOCIATED SURFACE COLD FRONT IS FORECAST TO MOVE
THROUGH CENTRAL NORTH CAROLINA FRIDAY AFTERNOON AND EVENING. ALL
OF THIS WILL RESULT IN PRECIPITATION CHANCES INCREASING LATE
THURSDAY...WITH THE BEST TIME FRAME FOR SHOWERS COINCIDING WITH
THE FRONTAL PASSAGE DURING THE DAY ON FRIDAY. AHEAD OF THE
FRONT...STRONG SOUTHWESTERLY SURFACE FLOW WILL PUSH TEMPERATURES
INTO THE UPPER 60S TO LOWER 70S ACROSS AREA ON BOTH THURSDAY AND
FRIDAY. ALSO...MOISTURE WILL POOL AHEAD OF THE APPROACHING
FRONT...WITH MAXIMUM PRECIPITABLE WATER VALUES FORECAST TO RANGE
BETWEEN ONE AND ONE AND A HALF INCHES. THIS SHOULD RESULT IN
SOME WEAK INSTABILITY OVER EASTERN NORTH CAROLINA...ALTHOUGH
CURRENT FORECAST SOUNDINGS SHOW VERY MARGINAL CAPE VALUES.
NEVERTHELESS...WILL MAINTAIN THE MENTION OF A SLIGHT CHANCE OF
THUNDER ACROSS THE COASTAL PLAIN...ESPECIALLY SINCE THE FRONTAL
PASSAGE IS EXPECTED TO OCCUR DURING A FAVORABLE TIME OF DAY.
BEHIND THE FRONT...HIGH PRESSURE WILL BUILD INTO THE REGION FOR THE
WEEKEND...WITH TEMPERATURES RETURNING TO NEAR NORMAL VALUES.
ANOTHER WARM UP SHOULD COMMENCE BY THE BEGINNING OF NEXT WEEK AS
THE HIGH IS EXPECTED TO SHIFT OFFSHORE BY MONDAY AHEAD OF OUR NEXT
SYSTEM... WHICH MAY BRING INCREASING PRECIPITATION CHANCES TO THE
AREA BY AS EARLY AS LATE MONDAY.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 115 PM...
VFR INTO THE NIGHT WITH SOME LOW STRATUS BEFORE SUNRISE. SOME
GUSTINESS TO AROUND 20 MPH THIS AFTERNOON. STRATUS DEVELOPING
BEFORE DAWN BUT COVERAGE IS UNCERTAIN. HAVE ELECTED TO ONLY PLACE
LOW CEILINGS WHERE CONFIDENCE IS HIGHEST... IN THE NORTHEAST AT
RALEIGH AND ROCKY MOUNT. RESTRICTIONS TO VISIBILITY MINIMAL TO
ABSENT DUE TO A LIGHT PERSISTENT BREEZE. ANY STRATUS DISSIPATES
NEAR MID MORNING AND GUSTINESS NEAR 20 MPH TO RETURN BY LATE
MORNING WEDNESDAY.
INCREASING RAIN CHANCES WITH ADVERSE AVIATION CONDITIONS ARE
EXPECTED RAIN LATE WEDNESDAY INTO WEDNESDAY NIGHT... AND AGAIN
LATE THURSDAY NIGHT INTO FRIDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CBL
LONG TERM...KRR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1027 AM EST TUE FEB 21 2012
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OUT INTO THE WESTERN ATLANTIC. A SERIES OF
UPPER LEVEL DISTURBANCES WILL MOVE THROUGH THE AREA THROUGH
WEDNESDAY...FOLLOWED BY A STRONG COLD FRONT PASSAGE ON FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1025 AM...
LATEST RUC MODEL SHOWS THICKNESSES INCREASING LATE AFTERNOON INTO
EVENING WITH THIS ENERGY REMAINING ALOFT. IT IS PRUDENT TO BACK
OFF THE 00Z THICKNESS VALUES REGARDING TEMPERATURE FORECASTS DUE
TO THIS TIMING AND ENERGY REMAINING ALOFT. MID LEVEL CLOUDINESS HAS
ARRIVED ON CUE INTO CENTRAL NORTH CAROLINA. THE CLEARING LINE
SHOULD PASS THE WESTERN PIEDMONT BEFORE NOON... EXITING TO THE
COASTAL PLAIN AT MID AFTERNOON. HOWEVER A LOOK AT UPSTREAM
TRAJECTORIES AND MOISTURE SUGGEST SOME CLOUDINESS BEHIND THE
CLEARING LINE... BUT NOT AS EXTENSIVE AS THIS MORNING. CURRENT
FORECAST OF MID TO UPPER 50S PERHAPS A TOUCH COOL... BUT THIS WILL
DEPEND ON AFTERNOON CLOUD COVER.
LOOKING AT CURRENT TEMPERATURE PROFILES AND SURFACE TEMPERATURE
FORECASTS... WIND GUSTS TO 20 MPH SHOULD HOLD OFF UNTIL EARLY
AFTERNOON.
THE QUESTION OF POSSIBLE VERY LOW STRATUS TONIGHT WILL BE THE
PROBLEM OF THE DAY... BUT WILL DELAY ANY CHANGES UNTIL ALL THE
MORNING MODELS ARE PROCESSED. ALTHOUGH SUBTLE... DECENT LOW LEVEL
ADVECTION IN THE MODELS WITH THE STRONGER WINDS OF THE NAM ATOP
THE BOUNDARY LAYER INVERSION WITH DECOUPLING MORE REALISTIC THAN
THE GFS. TEND TO FAVOR A FORECAST OF STRATUS FORMATION BUT
UNCERTAIN OF EXTENT AT THIS TIME. REGARDLESS TEMPERATURES WILL BE
MILD COMPARED TO THIS MORNING... WITH UPPER 30S TOO LOWER 40S
COMMON.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 250 AM TUESDAY...
BY WEDNESDAY A BROAD SCALE TROUGH WILL HAVE EVOLVED OVER THE
EASTERN TWO THIRDS OF THE COUNTRY WITH SEVERAL EMBEDDED FAST
MOVING PERTURBATIONS MOVING EAST ACROSS THE AREA IN THE
PROGRESSIVE ZONAL FLOW ALOFT. ONE OF THESE VORTICITY IMPULSES OF
NOTE IS FORECAST TO REACH THE SOUTHERN AND CENTRAL APPALACHIANS
AROUND 00Z THURSDAY...AND WILL THEN TRAVERSE THE CAROLINAS BY 06Z.
DPVA AND DYNAMIC COOLING/ASCENT ACCOMPANYING THE TROUGH PASSAGE
WILL STEEPEN MID AND UPPER LEVEL LAPSE RATES ACROSS THE AREA
WEDNESDAY EVENING AND ELIMINATE THE MID LEVEL CAP...WHICH SHOULD
ALLOW THE BAND OF SHOWERS TO SURVIVE EASTWARD AS THEY MOVE OFF THE
EASTERN SLOPES AND ACROSS THE AREA. UNFAVORABLE NOCTURNAL
TURNING/BOUNDARY LAYER STABILIZATION WILL IMPACT COVERAGE
HOWEVER...AND AT THIS TIME WILL CAP POPS OFF AT LOW TO SLIGHT
CHANCE...WITH HIGHEST POPS OVER THE WESTERN PIEDMONT AND ENDING
BEFORE DAYBREAK THURSDAY.
WILL SEE FULL COMPLIMENTS OF SUN ON WEDNESDAY AS THICKNESSES SOAR TO
AROUND 1350 METERS...A GOOD 20 TO 25 METERS ABOVE NORMAL. HIGHS IN
THE LOWER 60S NORTHWEST TO UPPER 60S SOUTHEAST. MILD OVERNIGHT
LOWS OF 46 TO 51.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 300 AM TUESDAY...
MODELS HAVE COME INTO BETTER AGREEMENT OVER THE PAST 24 HOURS WITH
RESPECT TO OUR NEXT SYSTEM THAT IS EXPECTED TO IMPACT THE REGION
DURING THE FIRST PART OF THE LONG TERM PERIOD. MODELS SHOW ANOTHER
SOUTHERN STREAM UPPER LEVEL TROUGH/LOW DIGGING INTO THE SOUTHWESTERN
UNITED STATES AND NORTHERN MEXICO TUESDAY INTO WEDNESDAY AND
EVENTUALLY EJECTING EASTWARD AND AFFECTING CENTRAL NORTH CAROLINA
THURSDAY INTO FRIDAY. DURING THE SAME TIME FRAME...A NORTHERN
STREAM TROUGH WILL AMPLIFY AS IT MOVES INTO THE CENTRAL UNITED
STATES...PROMOTING SURFACE CYCLOGENESIS ACROSS THE TENNESSEE AND
OHIO VALLEY. THE ASSOCIATED SURFACE COLD FRONT IS FORECAST TO MOVE
THROUGH CENTRAL NORTH CAROLINA FRIDAY AFTERNOON AND EVENING. ALL
OF THIS WILL RESULT IN PRECIPITATION CHANCES INCREASING LATE
THURSDAY...WITH THE BEST TIME FRAME FOR SHOWERS COINCIDING WITH
THE FRONTAL PASSAGE DURING THE DAY ON FRIDAY. AHEAD OF THE
FRONT...STRONG SOUTHWESTERLY SURFACE FLOW WILL PUSH TEMPERATURES
INTO THE UPPER 60S TO LOWER 70S ACROSS AREA ON BOTH THURSDAY AND
FRIDAY. ALSO...MOISTURE WILL POOL AHEAD OF THE APPROACHING
FRONT...WITH MAXIMUM PRECIPITABLE WATER VALUES FORECAST TO RANGE
BETWEEN ONE AND ONE AND A HALF INCHES. THIS SHOULD RESULT IN
SOME WEAK INSTABILITY OVER EASTERN NORTH CAROLINA...ALTHOUGH
CURRENT FORECAST SOUNDINGS SHOW VERY MARGINAL CAPE VALUES.
NEVERTHELESS...WILL MAINTAIN THE MENTION OF A SLIGHT CHANCE OF
THUNDER ACROSS THE COASTAL PLAIN...ESPECIALLY SINCE THE FRONTAL
PASSAGE IS EXPECTED TO OCCUR DURING A FAVORABLE TIME OF DAY.
BEHIND THE FRONT...HIGH PRESSURE WILL BUILD INTO THE REGION FOR THE
WEEKEND...WITH TEMPERATURES RETURNING TO NEAR NORMAL VALUES.
ANOTHER WARM UP SHOULD COMMENCE BY THE BEGINNING OF NEXT WEEK AS
THE HIGH IS EXPECTED TO SHIFT OFFSHORE BY MONDAY AHEAD OF OUR NEXT
SYSTEM... WHICH MAY BRING INCREASING PRECIPITATION CHANCES TO THE
AREA BY AS EARLY AS LATE MONDAY.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
AS OF 645 AM TUESDAY...
PREDOMINATELY VFR CONDITIONS THROUGH THE 24 HOUR TAF PERIOD.
HIGH PRESSURE CENTERED OVER THE REGION THIS MORNING WILL
SHIFT OFFSHORE THIS AFTERNOON. A WEAK UPPER LEVEL DISTURBANCE WILL
CROSS THE AREA ON TUESDAY. HOWEVER... BEST MOISTURE AND LIFT WILL
PASS WELL TO THE NORTH OF CENTRAL NORTH CAROLINA. THUS... DO NOT
EXPECT ANY SHOWERS TO ACCOMPANY THIS FEATURE. INSTEAD... EXPECT AN
INCREASE IN GENERALLY MID AND HIGH LEVEL CLOUD COVER...WITH LIGHT
AND VARIABLE WINDS BECOMING SOUTHWESTERLY AT 10 TO 15 MPH
SUSTAINED... GUSTING TO 20 MPH. A BRIEF PERIOD OF SUB VFR
CONDITIONS IN FOG OR STRATUS WILL BE POSSIBLE ON WEDNESDAY
MORNING...HOWEVER DUE TO LOW CONFIDENCE WILL NOT INCLUDE AT THIS
TIME.
OUTLOOK:
ANY FOG OR STRATUS WILL BURN OFF QUICKLY WEDNESDAY MORNING WITH
ANOTHER CHANCE OF SUB VFR CONDITIONS IN STRATUS OR FOG LATE
WEDNESDAY NIGHT AND THURSDAY MORNING. INCREASING RAIN CHANCES WITH
ADVERSE AVIATION CONDITIONS ARE EXPECTED RAIN LATE THURSDAY NIGHT
AND INTO FRIDAY AS THE A WAVY FRONTAL ZONE MOVES THROUGH THE AREA.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CBL
LONG TERM...KRR
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
830 PM CST WED FEB 22 2012
.DISCUSSION...FORECAST CHALLENGE FOR UPDATE CONCERNS SNOW CHANCES
AND TEMPERATURES.
PCPN WITH WESTERN WAVE CONFINED AT THIS POINT TO SW ND INTO NW SD.
BOTH RUC AND HIGH RESOLUTION RAPID REFRESH MODELS TRENDING SOUTH
KEEPING ANY SNOW OUT OF OUR SW-S FA. OPERATIONAL MODELS ALSO
GENERALLY KEEPING SNOW OUT OF FA. BASED ON CURRENT TRENDS AND MODEL
GUIDANCE PULLED POPS FROM SW FA PRIOR TO MIDNIGHT AND TRIMMED BACK
ON POPS AND COVERAGE AFTER MIDNIGHT. CLEAR SLOT ACROSS AREAS WEST OF
VALLEY AND A SMALL PART OF NW MN ALLOWING TEMPERATURES TO DROP OFF
QUICK APPROACHING EXPECTED MINIMUMS. DO EXPECT CLOUDS TO GRADUALLY
WORK BACK INTO CLEAR AREAS HOWEVER WITH A FEW MORE HOURS OF CLEAR
SKIES WILL NEED TO DROP MINIMUMS SOME AREAS. ALSO HAVE SOME PATCHY
FOG UNDER THE CLEAR SKIES BUT EXPECT THAT TO ALSO IMPROVE WITH CLOUD
COVER.
&&
.AVIATION...
MVFR-VFR CIGS CONTINUE GENERALLY ALONG AND EAST OF VALLEY. CLEARING
MAY GET EAST OF VALLEY LATER TONIGHT BUT NOT BY MUCH SO CIGS MAY
HOLD OVERNIGHT. WITH LIGHT WINDS SOME LOCALLY DENSE FOG DEVELOPING
IN CLEAR AREAS WEST OF VALLY AND A SMALL PART OF NW MN VCNTY TVF TAF
SITE. EXPECT CIGS TO GRADUALLY SPREAD BACK INTO THE REGION HOWEVER
UNTIL THEN FOG COULD BE A LOCAL PROBLEM.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
VOELKER
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1001 PM EST WED FEB 22 2012
.SYNOPSIS...
A WEAK COLD FRONT CROSSES TONIGHT AND ANOTHER WARM FRONT
THURSDAY. A STRONG COLD FRONT CROSSES THURSDAY NIGHT BRINGING
SHOWERS. FALLING TEMPERATURES FRIDAY. LIGHT SNOW SHOWERS FRIDAY
NIGHT INTO SATURDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
UPDATE...
SHOULD GET A BREAK FROM THE SHOWERS...BUT IR SATELLITE IMAGERY
SHOWING THE NEXT WAVE EMBEDDED IN THE BROAD CYCLONIC FLOW ALOFT
NOW PUSHING THROUGH SOUTHERN ILLINOIS AND INDIANA. ARRIVAL TIME TO
THE TRI STATE AREA LOOKING TO BE 07Z OR SO BASED ON THE HRRR WHICH
HAS A HOLD OF THIS FEATURE. HAVE BUMPED UP THE POPS IN THIS TIME
FRAME TO REFLECT THIS VORT MAX MOVING THROUGH.
PREVIOUS DISCUSSION...
CURRENT RADAR SHOWS SOME RETURNS ACROSS THE COAL FIELDS IN
ASSOCIATION WITH AN UPPER LEVEL SHORTWAVE TROUGH AND WEAK SURFACE
BOUNDARY...HOWEVER DEW POINT DEPRESSIONS ARE STILL PRETTY LARGE AND
HAVE NOT HAD ANY REPORTS OR PRECIP HITTING THE GROUND YET IN OUR CWA.
AS THE COLUMN SATURATES...SHOWERS ARE POSSIBLE THIS EVENING ACROSS
THE COAL FIELDS...EXTENDING NE INTO THE MOUNTAINS OVERNIGHT. HAS
NOT BEEN MUCH LIGHTNING ACTIVITY WITH THIS SINCE EARLIER THIS
MORNING...BUT HAVE LEFT MENTION OF THUNDER THROUGH EARLY EVENING
ACROSS SOUTHERN COAL FIELDS. CONVECTIVE SHOWERS...EVEN WITHOUT
THUNDER...COULD STILL ENHANCE TODAYS GUSTY WINDS AND PRODUCE
LOCALIZED GUSTS UP OF 40 TO 50 MPH.
AS A WARM FRONT PASSES THROUGH ANOTHER ROUND OF WARM AIR
ADVECTION SETS IN TOMORROW...SO WILL SEE A MILD TO WARM DAY ACROSS
THE REGION. THE LOWLANDS SHOULD WARM INTO THE UPPER 50S AND
60S...WITH THE MOUNTAINS TOPPING OUT IN THE LOWER 50S. A STRONG
COLD FRONT WILL BE APPROACHING FROM THE WEST ON THURSDAY...SO
COULD SEE SOME SHOWERS MOVING INTO SE OHIO BY LATE AFTERNOON AHEAD
OF THE COLD FRONT. TIME OF DAY IS NOT REAL CONDUCIVE TO
THUNDER...BUT COULD GET A RUMBLE OR TWO BEFORE EARLY EVENING AND
LOSS OF DIURNAL HEATING.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
COLD FRONT...FROM LOW PRESSURE THAT WILL MOVE ACROSS THE SOUTHERN
GREAT LAKES AND INTO THE ST. LAWRENCE RIVER VALLEY THURSDAY
NIGHT...WILL MOVE ACROSS THE CWA AND THROUGH THE REGION BY FRIDAY
MORNING. SHOWERS AND POSSIBLY A RUMBLE EARLY WILL MOVE THROUGH
WITH THE FRONT. MUCH COLDER AIR MOVES IN BEHIND THE FRONT ON
FRIDAY WITH 85H TEMPS DIPPING TO -8 TO -10 ON GOOD NORTHWEST FLOW.
SHOWERS WILL CONTINUE INTO SATURDAY AS UPPER TROUGH AND UPPER
LEVEL DISTURBANCES MOVE THROUGH THE REGION. AIR WILL BE COLD
ENOUGH THAT ANY SHOWERS WILL QUICKLY MIX OR CHANGE OVER TO LIGHT
SNOW AND COULD SEE SOME LIGHT ACCUMULATIONS ACROSS THE HIGHER
TERRAIN...ESPECIALLY IN THE UPSLOPE AREAS OF THE NORTHERN MOUNTAINS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
PERIOD GENERALLY DEFINED BY EXITING POSITIVELY TILTED SHORTWAVE
TROUGH TO THE NORTH OF AREA SAT EVENING WITH RIDGING BUILDING INTO
REGION FOR SUNDAY...FOLLOWED BY UPPER LEVEL CUTOFF LOW TO NORTHWEST
WITH ASSOCIATED SOUTHWEST FLOW ALOFT AHEAD OF IT ACROSS EASTERN
CONUS FOR MON-WED TIME FRAME.
SAT NIGHT LARGE SCALE SUBSIDENCE OVERSPREADS FORECAST AREA AS
AFOREMENTIONED SHORTWAVE TROUGH AXIS PROGRESSES ACROSS REGION. DEPTH
OF LOW LEVEL MOISTURE TRAPPED WITH SFC FLOW OFF GREAT LAKES SHOULD
BE SUFFICIENTLY DEEP TO KEEP SOME -SN GOING IN PREFERRED UPSLOPE
LOCATIONS. LIGHT SNOW WILL COME TO AN END BY EARLY SUNDAY MORNING
WITH RAPIDLY CLEARING SKIES AND SEASONAL AFTERNOON TEMPS AS UPPER
LEVEL RIDGING BUILDS INTO THE AREA. FLOW ALOFT RAPIDLY TURNS
SOUTHWEST FROM MON-WED HOWEVER AS UPPER LEVEL LOW PROGRESSES ACROSS
THE NORTH CENTRAL CONUS. THIS FEATURE ALONG WITH ASSOCIATED COLD
FRONT/MOISTURE FIELDS ARE WHERE LONG RANGE BEGIN TO DIVERGE. MUCH OF
THE LONG RANGE GUIDANCE LEANS TOWARDS A SLOWER SOLUTION...WHILE THE
GFS IS MUCH MORE PROGRESSIVE. GEFS LOOSELY SUPPORTS THE SLOWER
SOLUTION AS WELL AND THUS HAVE LEANED THE FORECAST IN THIS
DIRECTION.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
SHOWERS LIKELY OVER THE COAL FIELDS AND MOUNTAINS INTO
TONIGHT...WITH MVFR CEILINGS POSSIBLE OVER SAID AREAS. MAY SEE
VISIBILITIES DROPPING TO MVFR DURING MORE MODERATE SHOWERS.
WINDS ARE DECREASING IN INTENSITY...AND SHOULD LINGER AT AROUND
10KTS OVERNIGHT OUT OF THE WEST SOUTHWEST. GUSTS WILL PICK UP
AGAIN THURSDAY IN THE WARM SECTOR...AND COULD SEE 20-25KTS
DEVELOPING AFTER 16Z.
THE CENTER OF LOW PRESSURE APPROACHES...WITH PRECIPITATION CHANCES
INCREASING LATE...INTO THURSDAY EVENING.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z FRIDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: MVFR MAY NOT MATERIALIZE. TIMING OF SHOWERS
COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE THU 02/23/12
UTC 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
EST 1HRLY 21 22 23 00 01 02 03 04 05 06 07 08
CRW CONSISTENCY H H M M M M M M H H H H
HTS CONSISTENCY H H H H H H M M H H H H
BKW CONSISTENCY M M L M M M M H M M M M
EKN CONSISTENCY M M M H H H H H M M M M
PKB CONSISTENCY H H H H H H M H M M H M
CKB CONSISTENCY H H H M H M L M H H H H
AFTER 00Z FRIDAY...
IFR POSSIBLE IN STRONGER RAIN SHOWERS OR THUNDERSTORMS LATE
THURSDAY THROUGH THURSDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JS/ARJ/MZ/GG
NEAR TERM...ARJ/MZ/26
SHORT TERM...JS
LONG TERM...GG
AVIATION...26
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
653 PM CST WED FEB 22 2012
.DISCUSSION...SEE MARINE SECTION BELOW.
&&
.MARINE...NAM SHOWS LOW VISIBILITIES MOVING INTO THE NORTHERN BAYS
THIS EVENING AS DOES THE RUC TO A LESSER EXTENT. AM LESS CONFIDENT
THAT SEA FOG WILL ADVECT INTO THE BAYS SOUTH OF PORT
ARANSAS...HOWEVER FARTHER S IN PORT ISABEL...VSBYS ARE 1/4SM.
THEREFORE HAVE DECIDED TO EXPAND THE MARINE DENSE FOG ADVISORY
INTO THE BAYS...INCLUDING SOUTH OF PORT ARANSAS...AND EXTEND
TIMING UNTIL 15Z. VISIBILITIES MAY VARY AT TIMES BUT FEEL VSBY
WILL BE 1NM OR LESS A MAJORITY OF THE TIME TONIGHT/EARLY THU
MORNING...AT LEAST ACROSS THE COASTAL WATERS AND PORT ARANSAS
NORTHWARD.
&&
.PREV DISCUSSION... /ISSUED 341 PM CST WED FEB 22 2012/
SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)...FOR POTENTIAL
REMAINS A CHALLENGE THROUGH THE FORECAST PERIOD. HAVE SEEN MARINE
FOG JUST OFFSHORE THE COAST ALL DAY...AND AS LIGHT WINDS SHIFT
BACK A BIT FROM SOUTHWEST TO SOUTH TONIGHT...MAY SEE SOME OF THAT
SEA FOG PUSH INLAND...PRIMARILY NORTH OF CORPUS CHRISTI BAY. IF
WINDS WERE TO TURN EAST OF SOUTH...AS THE NAM INDICATES GOT COULD
PUSH INLAND AT CORPUS CHRISTI AS WELL. RADIATION FOG COULD ALSO BE
AN ISSUE IN THE EAST...BUT THINK THAT THE SOUTHWEST WINDS WE/VE
HAD TODAY SHOULD HELP TO KEEP THINGS FROM GOING DENSE IN MOST
AREAS.
WITH HIGH TEMPERATURES TODAY INTO THE 80S...AND IN SOME
AREAS...MIDDLE 80S...DONT SEE A REASON TO EXPECT COOLER NUMBERS
TOMORROW. WIND PATTERN LOOKS QUITE SIMILAR TOMORROW TO WHAT WE SAW
TODAY AND EXPECT MAINLY HIGH CLOUDS ONCE ANY FOG BURNS OFF. HAVE
GONE A FEW DEGREES WARMER THAN PREVIOUS FORECAST WITH SOME
LOCATIONS IN THE SOUTHWEST PART OF THE FORECAST AREA TOUCHING 90
DEGREES. THIS MAY EVEN STILL BE A LITTLE CONSERVATIVE AS NAM/GFS
GUIDANCE FOR COTULLA/LAREDO ABOVE 90...SO WOULD NOT BE SURPRISED TO
SEE SOME TEMPS IN THE LOWER 90S FAR WEST.
NEXT CHALLENGE BECOMES TIMING OF THE COLD FRONT. ECMWF AND
CANADIAN MODEL STILL LAGGING BACK A BIT WITH FRONT TIMING. GFS/NAM
SHOW FRONT THROUGH THE ENTIRE FORECAST AREA BY 12Z FRIDAY...WHILE
EC AND CANADIAN BISECT THE FORECAST AREA AT 12Z. HAVE GONE WITH
THE QUICKER SOLUTION FOR TIMING. WITH A MODERATE WIND INCREASE
IMMEDIATELY BEHIND THE FRONT.
MARINE...HAVE EXTENDED DENSE FOG ADVISORY THROUGH THE NIGHT.
WITH SEA SURFACE TEMPERATURES IN THE LOW TO MID 60S...AND
DEWPOINTS IN THE MID TO UPPER 60S...AND THE WIND PATTERN NOT
CHANGING SIGNIFICANTLY SEE NO REASON THIS FOG WILL MOVE OUT OR
DISSIPATE. BAYS AREAS FROM PORT ARANSAS NORTHWARD MAY SEE THE FOG
DRIFT BACK IN TONIGHT AS WE LOSE THE SOUTHWEST WIND COMPONENT OVER
LAND THAT HAS HELPED TO PUSH IT OUT TODAY. AN ADVISORY MAY BE
NEEDED FOR THE BAYS THIS EVENING OR TONIGHT. SOUTHERN BAYS ARE A
CHALLENGE AS SOME MODELS INDICATE A SOUTHEASTERLY WIND DEVELOPING
WHICH WOULD BRING THE FOG BACK INTO THESE BAYS AS WELL...FOR NOW
STICKING WITH MORE OF A SOUTHERLY WIND AND THE BAYS SOUTH OF PORT
ARANSAS STAYING OUT OF THE DENSE FOG.
LONG TERM (FRIDAY THROUGH WEDNESDAY)...AFTER SEVERAL DAYS OF NOT
CATCHING ON TO THE POSSIBILITY OF THE UPPER LOW BEING MUCH SLOWER
TO MOVE OUT OF NORTHERN MEXICO...THIS FORECASTER ALONG WITH MOST
OF THE MODELS HAVE COME AROUND TOWARD THE SLOWER GFS SOLUTION. THE
UPPER LOW IS WELL DETACHED FROM THE MAIN STREAM AND THE STRONG UPPER
TROUGH MOVING INTO THE CENTRAL PLAINS FRIDAY MORNING PASSES BY WELL
TO THE NORTH. EVEN 12Z ECMWF IS IN LINE WITH THE GFS SHOWING THE
WEAKENING LOW MOVING ACROSS THE AREA BY 12Z SATURDAY. THE MODELS
ARE REASONABLY SIMILAR WITH THE TIMING OF THE COLD FRONT INTO THE
REGION EARLY FRIDAY MORNING. ADEQUATE MOISTURE AHEAD OF THE FRONT
AND APPROACH OF THE UPPER LEVEL JET STREAK SHOULD KEEP A THREAT FOR
SHOWERS MAINLY OVER THE SOUTHERN PORTIONS OF THE FORECAST AREA INTO
THE GULF WATERS FRIDAY INTO FRIDAY NIGHT. BUT MOST OF THIS MOISTURE
WILL BE ELEVATED AND SHOULD SEE SOME DRYING IN THE BOUNDARY LAYER
BY FRIDAY AFTERNOON. WITH VERY STRONG NORTH-NORTHEAST WINDS AND
RH VALUES FALLING TO 30-35 PERCENT IN THE AFTERNOON...WILL KEEP
THE FIRE WEATHER WATCH GOING FOR THE COASTAL COUNTIES. BUT THE
CONFIDENCE IS NOT REAL HIGH AS CLOUD COVER SHOULD PERSIST AND ANY
LIGHT PRECIPITATION COULD KEEP RH VALUES ELEVATED ABOVE RED FLAG
CRITERIA. THEREFORE...STILL A WATCH. CLOUDS LINGERING OVER THE AREA
WILL KEEP MINIMUMS A BIT HIGHER FOR SATURDAY MORNING BUT COOLER
FOR MAX TEMPS. STILL LEANING TOWARD THE ECMWF/CAN/UKMET HANDLING OF
UPPER PATTERN FOR EARLY NEXT WEEK AS GFS LOOKS TOO PROGRESSIVE WITH
THE UPPER TROUGH MOVING INTO THE WESTERN UNITED STATES OVER THE
WEEKEND. ONSHORE FLOW WILL STEADILY INCREASE SUNDAY THROUGH MONDAY
WITH MOSTLY CLOUDY SKIES PREVALENT. A SHORT WAVE TROUGH LIFTS INTO
THE UPPER MIDWEST BY MONDAY MORNING THAT SHOULD SEND A WEAK FRONTAL
BOUNDARY INTO NORTH TEXAS MONDAY BUT STALL NORTH OF THE AREA. A
POSITIVE TILT UPPER TROUGH WILL MOVE THROUGH THE ROCKIES BY TUESDAY
MORNING WITH A FRONT MOVING INTO THE AREA TUESDAY NIGHT. LOW LEVEL
WARM AIR ADVECTION AHEAD OF THE FRONT SHOULD ALLOW FOR ISOLATED
STREAMER SHOWERS OVER MOST OF THE AREA MONDAY NIGHT THROUGH
WEDNESDAY.
89/TMT
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 66 83 62 64 45 / 10 10 30 30 30
VICTORIA 63 83 56 63 44 / 10 10 30 20 20
LAREDO 67 90 62 65 45 / 0 10 20 30 30
ALICE 65 86 62 64 46 / 10 10 20 30 30
ROCKPORT 64 80 60 63 48 / 10 10 30 30 30
COTULLA 60 87 55 64 42 / 0 10 20 20 20
KINGSVILLE 65 85 62 64 47 / 10 10 30 30 30
NAVY CORPUS 66 82 62 63 51 / 10 10 30 30 30
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...FIRE WEATHER WATCH FROM FRIDAY MORNING THROUGH FRIDAY AFTERNOON
FOR THE FOLLOWING ZONES: ARANSAS...CALHOUN...KLEBERG...
NUECES...REFUGIO...SAN PATRICIO.
GM...DENSE FOG ADVISORY UNTIL 9 AM CST THURSDAY FOR THE FOLLOWING
ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT ARANSAS...
BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT O`CONNOR...
COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT 20 NM...
COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL
OUT 20 NM...WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20
TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP
CHANNEL FROM 20 TO 60 NM.
&&
$$
TE/81...SHORT TERM/MARINE
WC/87...AVIATION
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1132 PM CST MON FEB 20 2012
.DISCUSSION...UPDATED FOR 6Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...TRANSITIONG TO IFR/LIFR CIGS/VSBYS TONIGHT ALL
TERMINALS WITH CONDITIONS SLOWLY IMPROVING TO MVFR LEVELS
TUESDAY AFTN THEN BACK TO IFR LATE IN THE FCST PERIOD. STRATUS
AND FOG XPCTD TO DVLP TONIGHT WITH CIGS LOWERING VSBYS REDDUCING
TO LIFR LEVELS OCCURRING FIRST AT KVCT/KALI THEN KCRP AND LAST AT
KLRD. CONDITIONS SHOULD BE SLOW TO IMPROVE TUES MRNG BUT SHOULD
EVENTUALLY MAKE IT TO MVFR LEVELS BY AFTN. CIGS AND VSBYS THEN TO
QUICKLY LOWER AGAIN BY LATE IN THE TAF FCST PERIOD TO IFR LEVELS
DUE TO LOW LEVEL MOISTURE INFLUX. LIGHT WINDS TONIGHT TO BECOME
LIGHT TO MODERATE FROM THE SE ON TUES.
&&
.PREV DISCUSSION... /ISSUED 943 PM CST MON FEB 20 2012/
DISCUSSION...MINOR CHANGES WERE MADE TO THE ONGOING FORECAST.
ALTERED CLOUD COVER TO REFLECT SLOWER DEVELOPMENT OF STRATUS AND
FOG FOR TONIGHT AND INCREASED DEWPOINTS SLIGHTLY. MSAS AND
SURFACE ANALYSES THIS EVENING HAVE A COLD FRONT DRAPED ACROSS
CENTRAL TX WITH THIS FRONT PROG TO DRIFT INTO AT LEAST NORTHERN
PORTIONS OF S TX BY LATE TONIGHT. AHEAD OF THE FRONT A GRADUAL
INFLUX OF LOW LEVEL MOISTURE WILL CONTINUE AND WITH LIGHT SURFACE
WINDS AND THE INCREASING MOISTURE AREAS OF FOG MAY DEVELOP.
STATISTICAL GUIDANCE CONTINUES TO INDICATE NEARLY WIDESPREAD FOG
TONIGHT WHILE RAW MODEL OUTPUT IS LESS PESSIMISTIC. NAM WANTS TO
DEVELOP FOG ACROSS MANY INLAND LOCATIONS SHORTLY AFTER MIDNIGHT
BUT DISSIPATES MUCH OF IT SHORTLY BEFORE SUNRISE. LATEST RUC HAS
AREAS OF FOG DEVELOPING AND DISSIPATING ON AND OFF THROUGH THE
NIGHT. DENSE CIRRUS PERSISTS ACROSS S TX TONIGHT AS UPPER JET
REMAINS OVERHEAD AND UNCERTAINTY REMAINS AS TO HOW MUCH OF AN
INFLUENCE THAT WILL HAVE ON FOG DEVELOPMENT AS WELL. FOR NOW WILL
MAINTAIN AREAS OF FOG IN THE FORECAST. UPDATED PRODUCTS TO BE
SENT SOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 57 74 61 76 64 / 10 10 20 20 30
VICTORIA 55 73 57 76 60 / 10 10 10 10 30
LAREDO 58 74 64 82 65 / 10 10 10 10 30
ALICE 56 75 60 79 63 / 10 10 20 10 30
ROCKPORT 58 73 60 67 64 / 10 10 20 20 30
COTULLA 51 73 58 80 63 / 10 10 10 10 30
KINGSVILLE 55 74 60 77 64 / 10 10 20 20 30
NAVY CORPUS 60 72 61 69 64 / 10 10 20 20 30
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
AVIATION...HART/79
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
1126 PM CST MON FEB 20 2012
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...PLUME OF PACIFIC MOISTURE STREAMING OVERHEAD AS THICK
CIRRUS DECK WILL CONTINUE THROUGH THE OVERNIGHT HOURS. THIS WILL
HOLD TEMPS UP A COUPLE DEGREES AND SHOULD KEEP FOG FROM BECOMING
DENSE. HAVE PARED BACK FOG WORDING IN TAFS TO TEMPOS AND NO
THICKER THAN 1SM AROUND DAWN. CIGS WILL GRADUALLY LIFT THROUGH THE
MORNING AND SHOULD BE AROUND 3000 FEET JUST AFTER NOON.
&&
.PREV DISCUSSION... /ISSUED 856 PM CST MON FEB 20 2012/
DISCUSSION...GUIDANCE IS BULLISH ON LOW CEILINGS AND PATCHY TO
AREAS OF FOG TONIGHT THROUGH MID TUESDAY MORNING. SCT TO BKN HIGH
CLOUDS NOT PLAYING A MAJOR ROLE. RUC IS SHOWING AMPLE LOW LEVEL
MOISTURE...COUPLED WITH CONTINUING LIGHT ONSHORE WINDS. WIDESPREAD
DENSE FOG IS NOT EXPECTED...BUT LOCAL AREAS OF DENSE FOG WILL BE
POSSIBLE...ESPECIALLY IN THE MID AND UPPER VALLEY. SAT IMAGERY
ALSO SUGGESTS LOW CLOUDS IN THE WEST GULF MOVING NORTHWEST TOWARD
THE REGION. BEEFED UP THE WORDING IN THE FORECAST AND REISSUED TO
REFLECT THE DEVELOPING SITUATION.
PREV DISCUSSION... /ISSUED 523 PM CST MON FEB 20 2012/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...FOG AND LOWER CEILINGS LOOK PRETTY CERTAIN TONIGHT
WITH WINDS BECOMING LIGHT AND INCREASING LOW LEVEL MOISTURE. SCT
TO BKN HIGH CLOUDS WILL NOT BE ENOUGH TO PREVENT TEMPERATURES FROM
DECREASING TO THE CORRESPONDING DEW POINTS TONIGHT. LOCALLY DENSE
FOG LOOKS LIKELY IN THE MID AND UPPER VALLEY...BUT IFR CONDITIONS
ARE DEFINITELY ON TAP FOR THE LOWER VALLEY...DEVELOPING AFTER
MIDNIGHT WITH WORSENING CONDITIONS THROUGH DAWN TO MID TUESDAY
MORNING. NOT READY TO POUNCE ON A DENSE FOG ADVISORY JUST YET...
BUT WILL PROBABLY BEEF UP THE FOG CHARACTERIZATION SOMEWHAT IN A
LOCAL FORECAST UPDATE. THE TAFS TAKE FOG INTO ACCOUNT NOW.
PREV DISCUSSION... /ISSUED 120 PM CST MON FEB 20 2012/
SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...NORTHEAST FLOW ALOFT
WILL CONTINUE TO STREAM CIRRUS CLOUDS ACROSS THE RIO GRANDE VALLEY
AS MID LEVEL MOISTURE OVER THE PACIFIC IS BEING PUSH INTO THE
AREA. SURFACE SOUTHEAST FLOW WITH GUSTY WINDS WILL PREVAIL THROUGH
THE AFTERNOON. EXPECT WINDS TO BEGIN TO DECOUPLE AFTER SUNSET.
GOOD MOISTURE IN THE AREA AND LIGHT SOUTHEAST WINDS WILL PROVIDE
GOOD CONDITIONS FOR PATCHY FOG TO DEVELOP AFTER MIDNIGHT.
LOCATIONS FURTHER NORTH AND WEST WILL LIKELY SEE MORE DENSE FOG
THAN THE LOWER VALLEY TONIGHT. LOW TEMPERATURES WILL REMAIN IN THE
MID 60S ALONG THE COAST AND LOCATIONS CLOSE TO THE BORDER WITH THE
COOLER SPOTS IN THE NORTHERN COUNTIES. NO MUCH PRECIPITATION
EXPECTED UNTIL TUESDAY NIGHT INTO WEDNESDAY MORNING AS A WEAK
DISTURBANCE WITHIN THE UPPER LEVEL FLOW MOVES ACROSS THE AREA.
HIGH TEMPERATURES WILL WARM BACK REACHING CLOSE TO THE 80S.
ANOTHER ROUND OF WIDESPREAD FOG WILL LIKELY DEVELOP WEDNESDAY
AFTER MIDNIGHT. LIGHTER WINDS AND MORE MOISTURE IN THE AREA WILL
ENHANCE THE DEVELOPMENT OF FOG TO BE MORE WIDESPREAD ACROSS THE
FORECAST AREA.
LONG TERM /WEDNESDAY THROUGH SUNDAY/...NO SIGNIFICANT CHANGES WERE
MADE TO THE FORECAST IN THE LONG TERM. SCATTERED SHOWERS ARE EXPECTED
WEDNESDAY AND WEDNESDAY NIGHT DUE TO THE SLOW PROGRESSION OF A 500 MB
CLOSED LOW OVER THE NORTHWEST CORNER OF MEXICO. AS THE LOW FILLS AND
DRAGS A SHARP MID-LEVEL TROUGH THROUGH THE LONE STAR STATE...A WEAK
PACIFIC COLD FRONT WILL PASS THROUGH DEEP SOUTH TEXAS AND THE RIO
GRANDE VALLEY THURSDAY...WITH SCATTERED SHOWERS AND THUNDERSTORMS.
A MORE SIGNIFICANT COLD FRONT WILL PASS THROUGH OUR REGION THURSDAY
NIGHT...HOWEVER DRIER AIR ASSOCIATED WITH THE WAKE OF THE PACIFIC
COLD FRONT WILL PREVENT ANY PRECIPITATION FOR THAT TIME. PLEASANT
CONDITIONS ARE FORECAST FRIDAY THROUGH SUNDAY WITH DRY WEATHER DUE
TO A NEARLY ZONAL FLOW IN THE MIDDLE LAYERS OF THE ATMOSPHERE OVER
THE BRO CWFA FOR THAT PERIOD. NEAR TO ABOVE NORMAL TEMPERATURES
WEDNESDAY AND THURSDAY WILL BE COOLED TO NEAR NORMAL LEVELS FRIDAY
AND SATURDAY COURTESY OF THE COLD FRONTAL PASSAGE THURSDAY NIGHT...
WITH WARMING TEMPERATURES ANTICIPATED FOR SUNDAY DUE TO AN ONSHORE
FLOW.
MARINE...TONIGHT THROUGH TUESDAY NIGHT...SEAS AND WINDS CONDITIONS
WILL REMAIN FAIRLY GOOD ACROSS THE GULF WATERS THE REST OF TODAY
INTO TUESDAY NIGHT. SOUTHEAST WINDS WILL DECOUPLE THIS EVENING
BECOMING LIGHT OVER THE GULF WATERS TONIGHT. LIGHT ISOLATED
SHOWERS WILL LIKELY DEVELOP OVER THE OFFSHORE WATERS TUESDAY
AFTERNOON INTO THE EVENING AS A WEAK DISTURBANCE MOVES ACROSS THE
AREA.
WEDNESDAY THROUGH SUNDAY...FAVORABLE MARINE CONDITIONS WILL PERSIST
WEDNESDAY THROUGH THURSDAY EVENING...WITH LIGHT TO MODERATE WINDS
AND LOW TO MODERATE SEAS EXPECTED...AS HIGH PRESSURE INITIALLY
PREVAILS...WITH THE PASSAGE OF A WEAK COLD FRONT THURSDAY EVENING.
THE PASSAGE OF A MORE SIGNIFICANT COLD FRONT THURSDAY NIGHT WILL
RAPIDLY INCREASE WINDS AND BUILD SEAS IN ITS WAKE...AND A SMALL
CRAFT ADVISORY MAY BE NEEDED FOR ALL OR PORTIONS OF THE ADJACENT
COASTAL WATERS OF DEEP SOUTH TEXAS AND THE RIO GRANDE VALLEY
THURSDAY NIGHT THROUGH FRIDAY NIGHT. STRONG WINDS AND ROUGH SEAS
WILL PREVAIL FOR SATURDAY AND SUNDAY WITH HIGH PRESSURE OVER THE
GULF OF MEXICO INTERACTING WITH LOWER PRESSURE OVER NORTH TEXAS.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WWW.WEATHER.GOV/BROWNSVILLE
64
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
842 PM EST WED FEB 22 2012
.SYNOPSIS...
A COLD FRONT WILL WORK SOUTHEAST INTO THE AREA LATE TONIGHT
STALLING ACROSS THE REGION THURSDAY. THE FLOW WILL STAY MAINLY SOUTHWESTERLY
INTO THURSDAY WITH TEMPERATURES ABOVE SEASONAL UNTIL THE PASSAGE OF A
STRONGER COLD FRONT FRIDAY. A RETURN TO SEASONAL CONDITIONS IS
ANTICIPATED FOR THE WEEKEND WITH COOLER TEMPERATURES AND MOUNTAIN
SNOW SHOWERS.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 830 PM EST WEDNESDAY...
AREA OF SHOWERS MOVING NE ALONG THE INTERSTATE 81 CORRIDOR AND
EITHER SIDE THIS EVENING...AHEAD OF SFC TROUGH. RAINFALL AMOUNTS
HAVE BEEN RUNNING LOWER THAN ADVERTISED BY RADAR DUE TO SOME
BRIGHT BANDING. THERE ARE POCKETS OF HEAVIER SHOWERS...AND HAVE
SEEN UPWARDS OF THREE QUARTERS OF AN INCH OF RAIN OVER THE
BLAND/TAZEWELL AREA SINCE 630 PM. COVERING HEAVY SHOWERS AND
ISOLATED THUNDERSTORMS WITH SPECIAL WX STATEMENTS. WILL HAVE TO
MONITOR THE TRAINING OF THE HEAVIER CELLS FOR POTENTIAL FLOOD
ADVISORIES OR WARNINGS.
THE 22Z HRRR SHOWING THE LINE OF CONVECTION WORKING SE THROUGH
MIDNIGHT AND EXITING THE CWA BY 08Z. WILL LEAN TOWARD ITS SOLUTION
GIVEN HOW ITS HANDLING THIS CONVECTION. THE UPPER SHORTWAVE
ENERGIZING THIS WILL MOVE EAST OF THE FA BY MIDNIGHT WITH THE NEXT
UPSTREAM SHORTWAVE AHEAD OF THE FRONT WEAKENING AS IT SHEARS EWD OVERNIGHT.
BUMPED UP TEMPS THROUGH THE NIGHT GIVEN SLOWER MOVEMENT OF COOLER
AIR.
THROUGH THE MORNING...A WARM FRONT WILL BACK THE WINDS TO THE
SOUTHWEST. 85H TEMPERATURES FORECASTED FOR EARLY TOMORROW MORNING
ARE +2C/+5C AND ARE EXPECTED TO JUMP TO +9C/+11C IN THE AFTERNOON.
THIS TRANSLATES IN TO 15F-20F ABOVE NORMAL SURFACE TEMPERATURES
TOMORROW.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 330 PM EST WEDNESDAY...
NORTHERN STREAM TROF DIG OVER THE EASTERN UNITED STATES AT THE END
OF THE WEEK. MODELS WERE STILL DIFFERENT WITH THE TIMING OF THE COLD
FRONT COMING...WITH THE ECMWF AT LEAST 12 HOURS SLOWER THAN THE GFS
AND NAM. HAVE TRENDED TOWARD THE SLOWER SOLUTION...SO EXPECTING THE
FRONT TO COME THROUGH ON FRIDAY. MODELS SHOWING VERY LIMITED
CONVECTIVE AVAILABLE POTENTIAL ENERGY AHEAD OF THE FRONT. HAVE ADDED
A SLIGHT CHANCE OF THUNDERSTORMS IN THE FAR SOUTHEAST PART OF THE
COUNTY WARNING AREA ON FRIDAY AFTERNOON.
AHEAD OF THE FRONT...WITH THE FORECAST AREA IN THE WARM SECTOR
THURSDAY NIGHT AND FRIDAY...TEMPERATURES WILL REMAIN ABOVE NORMAL.
STAYED CLOSER TO WARMER MAV GUIDANCE FOR LOWS THURSDAY NIGHT AND
HIGHS ON FRIDAY.
BEHIND THE FRONT...850 MB TEMPERATURES DROP INTO TH -5 TO -8 RANGE.
STRONG DOWNSLOPING WILL CLEAR OUT CLOUDS EAST OF THE BLUE RIDGE.
PLENTY OF LOW LEVEL MOISTURE TO GENERATE CLOUDS AND SNOW SHOWERS IN
THE WESTERN UPSLOPE AREAS. DECENT PRESSURE RISES BEHIND THE FRONT
AND LOW LEVEL JET MAY BE CLOSE TO 50 KNOTS...BUT FOR NOW HAVE KEPT
WIND GUSTS BELOW ADVISORY CRITERIA.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 230 PM EST WEDNESDAY...
COLD FRONT WILL MOVE EAST INTO THE ATLANTIC OCEAN...AS HIGH PRESSURE
BUILDS IN ITS WAKE ACROSS OUR REGION SATURDAY NIGHT. UPPER RIDGING
WILL BUILD OVER THE FORECAST AREA SUNDAY AND MONDAY. AT THE SURFACE
HIGH PRESSURE WILL BE CENTERED OVER THE REGION SUNDAY MORNING...
THEN MOVE EAST OFFSHORE ON MONDAY. TEMPERATURES AT 850 MB WARM BACK
UP INTO THE +4 TO +8 RANGE FOR MONDAY AND TUESDAY WITH INCREASING
SOUTHWEST FLOW.
TIMING DIFFERENCE CONTINUE WITH THE NEXT UPPER TROF APPROACHING
FROM THE NORTHERN STREAM. THE GFS REMAINS FASTER THAN THE ECMWF AND
CANADIAN. WILL FOLLOW HPCGUIDE DECISION TO USE A A GFS/ECMWF ENS
MEAN WITH THE COLD FRONT TRAVELING INTO THE FORECAST AREA ON
TUESDAY. UNSETTLED WEATHER CONTINUES TUESDAY NIGHT INTO
WEDNESDAY...AS A WAVE DEVELOPS AND LIFTS NORTHEAST. IN GENERAL FOR
TEMPERATURES FOLLOWED HPCGUIDE WITH A FEW MINOR ADJUSTMENTS.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
AS OF 630 PM EST WEDNESDAY...
BLF/BCB/LWB WILL BE AFFECTED BY SHOWERS THIS EVENING REACHIN
ROA/LYH/DAN BY 03Z. SOME INSTABILITY ALOFT MAY BRING A CLOUD TO
GROUND LIGHTNING STRIKE TO BLF/BCB...BUT CONFIDENCE IS LOW SO DID
NOT ADD TS TO THE FORECAST BUT INSTEAD COVERED WITH CB. POTENTIAL
EVEN FOR SOME LOW TOPPED CONVECTION OUT EAST.
OVERALL...CIGS SHOULD STAY VFR ROANOKE AND POINTS EAST...MAYBE AN
OCCASIONAL DROP TO MVFR IN A HEAVIER SHOWER.
THE MTNS WILL SEE CIGS DROP FROM VFR TO MVFR AND EVENTUALLY IFR
ESPECIALLY AT BLF...WHEN WINDS BEHIND THE TROUGH TURN WEST AND
BRING A LOW DECK IN AROUND 1KFT. THINK BCB WILL STAY VFR WITH
OCCASIONAL MVFR CIGS THIS EVENING.
LOW LEVEL MOISTURE MAY LINGER IN THE MOUNTAINS EARLY THURSDAY BUT SHOULD
DISPERSE BEFORE NOON.
VFR CONDITIONS THURSDAY WILL BE BRIEF. ANOTHER ROUND OF SHOWERS IS
LIKELY FRIDAY. PASSAGE OF A STRONG COLD FRONT FRIDAY WILL BRING
COLDER TEMPERATURES TO THE AREA WITH MOUNTAIN SNOW SHOWERS FRIDAY
NIGHT AND SATURDAY. MVFR/IFR CONDITIONS ARE LIKELY TO PERSIST IN
THE MOUNTAINS THROUGH SATURDAY. STRONG NORTHWEST WINDS SHOULD
BRING CLEARING EAST OF THE BLUE. SURFACE WIND GUSTS OF 20 TO 30
KTS LIKELY AT ALL TERMINALS FRIDAY NIGHT AND SATURDAY.
HIGH PRESSURE TO PASS OVERHEAD SUNDAY...A RETURN TO LIGHT WINDS
AND WIDESPREAD VFR.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...RCS/WP
NEAR TERM...RCS/WP
SHORT TERM...AMS
LONG TERM...KK
AVIATION...RCS/WP
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1149 AM CST TUE FEB 21 2012
.UPDATE...POPS ARE ANTICIPATED TO DECREASE AS THE DAY PROGRESSES.
CURRENT RADAR TRENDS SHOW REFLECTIVITY DECREASING WITH TIME AS IT
MOVES WSW-NE. ALTHOUGH...MODELS...SPECIFICALLY HRRR AND NAM ARE
SHOWING PRECIP IN THE AFTERNOON...THE FORMER HINTING AT A CELLULAR
FORM. CURRENT PRECIP THATS FALLING OVER THE CWA HAS SWITCHED OVER
TO RAIN...EXCEPT FOR MAYBE IN THE FAR NORTHERN PART OF THE CWA.
ANY PRECIP IN THE AFTERNOON WILL BE RAIN. UPDATED THE WX AND POP
FCSTS TO REFLECT RADAR WEAKENING TREND...IN ADDITION TO HI-RES
MODEL GUIDANCE. AFTERNOON HAVE CHANCE POPS...WHICH WERE ALREADY IN
PLACE...GIVEN LOW-LEVEL WAA...CONVERGENCE...AND INCREASING LAPSE
RATES WITH TIME. CURRENT T/TD TRENDS APPEAR ON TRACK.
&&
.AVIATION/18Z TAFS/...PRECIP MAINLY CONFINED TO NORTH OF MADISON
AND MILWAUKEE RIGHT NOW. MODELS INDICATE CHANCE FOR SHOWERS THIS
AFTERNOON...MAINLY EAST OF MADISON AS UPPER TROUGH AXIS SWINGS
THROUGH. TEMPS WILL CONTINUE TO WARM INTO THE AFTERNOON...AND
MODELS SOUNDINGS SHOW THE WARM LAYER ABOUT 2 KFT DEEP...SO PRECIP
WILL PROBABLY BE MAINLY RAIN.
IFR CIGS WILL LIKELY IMPROVE TO MVFR THIS AFTERNOON. A FEW
DIFFERENT MODEL SOLUTIONS FOR CLOUDS TONIGHT...BUT OVERALL LOOKS
LIKE CIGS MAY SCATTER BY AROUND MIDNIGHT. MODEL SOUNDINGS STILL
HINTING AT SLIGHT CHANCE FOR CONVECTIVE SHOWER DEVELOPMENT TOWARD
AND INTO THIS EVENING. WILL HAVE TO MONITOR RADAR AND MODEL
TRENDS TO CONSIDER EXTENDING SLIGHT CHANCE INTO THE EVENING.
LOOKS PRETTY QUIET THEN TROUGH THE DAY WEDNESDAY. DEBATING
WHETHER OR NOT TO KEEP SLIGHT CHANCE FOR RAIN TOMORROW
AFTERNOON...AS MODELS ARE GENERALLY DRY.
&&
.PREV DISCUSSION... /ISSUED 408 AM CST TUE FEB 21 2012/
SHORT TERM...
TODAY...FORECAST CONFIDENCE MEDIUM TO HIGH
DRY AIR IN THE LOW LEVELS IS LIMITING PCPN COVERAGE OVER ERN WI AND
NE IL EARLY THIS AM BUT BELIEVE ATM WILL EVENTUALLY SATURATE AND NRN
BAND OF PCPN OVER CENTRAL IL ASSOCIATED WITH A STRONG SHORTWAVE
TROUGH AND JET STREAK SHOULD AFFECT AT LEAST THE SRN CWA LATER THIS
AM. EXPECT PCPN TO REMAIN LIGHT AS THAT IS WHAT HAS BEEN OBSERVED TO
THE SOUTH AND AS THE SHORTWAVE TROUGH TRACKS MORE TO THE SOUTH FROM
MO TO NRN OHIO. A RAIN SNOW MIX IS EXPECTED IN FAR SE WI WITH LGT
SNOW ELSEWHERE...BUT GIVEN MILD TEMPS AND LIGHT QPF...SNOW TOTALS
SHOULD REMAIN AROUND ONE HALF INCH OR LESS. THE DRY SLOT WILL ARRIVE
IN THE AFTERNOON AS CYCLOGENESIS OCCURS IN THE ARROWHEAD OF MN. FCST
SOUNDINGS DO SHOW STEEP LAPSE RATES AND SOME SKINNY CAPE THIS
AFTERNOON...THUS KEPT A SLIGHT CHANCE OF RAIN/SNOW SHOWERS.
TONIGHT...FORECAST CONFIDENCE...MEDIUM.
PRECIP WILL END BY THIS EVENING AS THE SFC LOW AND UPPER LOW REACH
EASTERN ONTARIO AND DRIER AIR AND SUBSIDENCE SETTLE INTO SOUTHERN
WI. STEEP LOW-LEVEL LAPSE RATES TUESDAY EVENING AS POCKET OF COLDER
DRIER AIR WORKS UNDER LOW. SOME MOISTURE CONVERGENCE ON THE LEADING
EDGE OF THE COLD AIR COULD LEAD TO A FEW FLURRIES...BUT NOT ENOUGH
TO REALLY MENTION IN THE FCST. SKIES SHOULD GO FROM CLOUDY TO PARTLY
CLOUDY FROM SOUTHWEST TO NORTHEAST THROUGH THE NIGHT. LOW TEMPS
EXPECTED TO DROP INTO THE UPPER 20S TOWARD WED MORNING.
WEDNESDAY...FORECAST CONFIDENCE...MEDIUM.
DRY WEATHER WEDNESDAY MORNING...THEN A SLIGHT CHANCE OF RAIN IN THE
AFTERNOON WITH WARM AIR ADVECTION AHEAD OF NEXT SHORT WAVE. 925MB
TEMPERATURES SUPPORT HIGHS IN THE LOWER 40S.
WEDNESDAY NIGHT THROUGH FRIDAY NIGHT...FORECAST CONFIDENCE LOW TO
MEDIUM.
AN UPPER TROUGH DEVELOPING OVER THE CENTRAL CONUS COULD BRING PRECIP
TO WI AS WEAK UPPER LEVEL DISTURBANCES ROLL ACROSS THE REGION. THE
MAIN BAROCLINIC ZONE WILL BE ACROSS CENTRAL IL...WHICH WILL MAKE
PRECIP CHANCES AND PRECIP TYPE QUITE UNCERTAIN. MODELS ARE ALL OVER
THE PLACE WITH TIMING AND PRECIP LOCATION. BEST CHANCE FOR PRECIP
WILL BE ACROSS SOUTHERN WI. WITH WARM BOUNDARY LAYER TEMPS...ANY
PRECIP SHOULD START OUT AS RAIN AND THEN POSSIBLY SWITCH OVER TO
SNOW FOR THE LATTER HALF OF WED NIGHT. WARM TEMPS WILL BRING PRECIP
BACK TO MAINLY RAIN ON THU.
COLD AIR ADVECTION WITH LINGERING MOISTURE AND STEEP LOW LEVEL LAPSE
RATES WILL CONTINUE THE CHANCE OF PRECIP AS SNOW THU NIGHT. CYCLONIC
FLOW WILL HANG AROUND THE UPPER GREAT LAKES REGION THROUGH
FRIDAY...SO SNOW SHOWER CHANCES WILL PERSIST THROUGH POSSIBLY FRI
EVENING.
TEMPS ON THU SHOULD BE SIMILAR TO WED IN THE LOWER 40S...THEN COOLER
IN THE MID 30S ON FRIDAY...STILL ABOVE NORMAL.
LONG TERM...
SATURDAY AND SATURDAY NIGHT...FORECAST CONFIDENCE MEDIUM.
THERE SHOULD BE A DRY PERIOD SATURDAY AND SATURDAY NIGHT WITH 500MB
RIDGING. DESPITE PARTLY CLOUDY SKIES...CONSENSUS OF MODELS SHOW MAX
TEMPS ONLY IN THE LOWER 30S...ALTHOUGH THERE IS A PRETTY BIG MODEL
SPREAD IN THE FCST TEMPS.
SUNDAY THROUGH TUESDAY...FORECAST CONFIDENCE...LOW.
MODELS CONTINUE TO BE HIGHLY VARIABLE WITH THE STRUCTURE AND TIMING
OF STRONG SHORT WAVE AND ASSOCIATED SURFACE LOW EJECTING FROM
DEEPENING WESTERN TROUGH IN THE SUNDAY/MONDAY TIME FRAME. HPC MODEL
BLEND SOLUTIONS FAVOR THE ECMWF AND ECMWF ENSEMBLES...WITH THE SFC
LOW TRACKING FROM EASTERN CO THROUGH IA AND ACROSS LAKE SUPERIOR
FROM SUN THROUGH TUE. THE GFS TRACKS THE SFC LOW STRAIGHT EAST
ACROSS THE WI/IL BORDER INTO LOWER MI. ECMWF HAS A WARMER SOLUTION
WHILE THE GFS WOULD FAVOR SNOW OR RAIN/SNOW MIX.
HUGE UNCERTAINTY IN PRECIP TYPE...BUT SOUTHERN WI SHOULD BE IN THE
TRANSITION AREA BETWEEN SNOW TO THE NORTH AND RAIN TO THE SOUTH.
THIS IS ALSO SUPPORTED BY EXPECTED MAX TEMPS.
AVIATION/12Z TAFS/...MVFR TO IFR CIGS AND VSBYS WILL BECOME
WIDESPREAD THIS AM AS THE RAIN AND SNOW OVERSPREADS THE REGION. THE
PCPN WILL MOSTLY END BY AFTERNOON WITH SOME ISOLD SHOWERS REMAINING.
VSBYS WILL IMPROVE TO VFR AS BRISK WEST WINDS AND SLIGHTLY DRIER AIR
INVADE THE REGION IN THE WAKE OF THE COLD FRONT. MVFR CIGS WILL
PREVAIL IN THE AFTERNOON AND THEN GRADUALLY DECREASE IN COVERAGE
WITH SCT CLOUD COVER EXPECTED SOMETIME THIS EVENING.
MARINE...A SMALL CRAFT ADVISORY IS IN EFFECT UNTIL 15Z WED. A COLD
FRONT OVER THE STATE OF IA EARLY THIS MORNING WILL MOVE NEWD AND
REACH LAKE MI AROUND NOON. THUS THE SELY WINDS THAT BROUGHT THE HIGH
WAVES WILL VEER TO THE WSW WITH WAVE HEIGHTS DECREASING DUE TO THE
OFFSHORE FLOW. HOWEVER BRISK WSWLY WINDS AND GUSTY WINDS WILL THEN
PREVAIL THIS AFTERNOON...TNT...AND INTO WED AM AS LOW PRESSURE
INTENSIFIES OVER LAKE SUPERIOR AND ONTARIO CANADA.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 9 AM CST WEDNESDAY FOR LMZ643>646.
&&
$$
UPDATE...ET/DDV
TODAY/TONIGHT AND AVIATION/MARINE...GEHRING
WEDNESDAY THROUGH MONDAY...MRC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
312 AM CST TUE FEB 21 2012
.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
312 AM CST TUE FEB 21 2012
FORECAST CONCERNS FOCUS ON SNOW/RAIN TODAY...THEN ON ADDITIONAL
PRECIPITATION CHANCES THROUGH THE REST OF THE WEEK.
WATER VAPOR/IR SATELLITE IMAGERY EARLY THIS MORNING SHOWING COMPACT
MID-LEVEL CLOSED LOW OVER NORTHERN MO SLOWLY PHASING WITH A TROUGH
PUSHING INTO WESTERN MN. MOISTURE ADVECTION AND STRONG ISENTROPIC
LIFT AHEAD OF THESE FEATURES PRODUCED A SIGNIFICANT WING OF
LIGHT-MODERATE SNOW ACROSS THE FORECAST AREA OVERNIGHT WITH 1-1.5
INCHES REPORTED ALONG/WET OF THE MISSISSIPPI RIVER. CURRENT RADAR
MOSAIC AT 2 AM SHOWING THE MAIN WING OF LIGHT-MODERATE SNOW HAS
WEAKENED OVER THE LAST COUPLE OF HOURS AND HAS PUSHED NORTHEAST OF
THE I-94 CORRIDOR. MEANWHILE...IR SATELLITE/RADAR TRENDS SHOWING SOME
REGENERATION OF SNOW/RAIN ACTIVITY WEST OF THE MISSISSIPPI ALONG THE
I-35 CORRIDOR...AND WAS MOVING EAST. THIS WAS IN RESPONSE TO
STRETCHING DEFORMATION/INCREASING MID-LEVEL FRONTOGENESIS AREA
BETWEEN THE NORTHERN MID-LEVEL TROUGH AND THE CLOSED LOW LIFTING
NORTHEAST OUT OF NORTHERN MO.
21.00Z NCEP MODELS AND THE 21.03Z SREF SHOWING PRETTY DECENT
AGREEMENT THROUGH WEDNESDAY...BUT THEN START DIVERGING WED N/THU WITH
INCOMING WAVE IN NORTHWEST FLOW ALOFT. HAVE LEANED TOWARD A BLEND
APPROACH FOR NOW.
FOR TODAY...WILL BE KEEPING A CLOSE EYE ON THAT DEFORMATION BAND
PRECIPITATION MOVING EAST THROUGH THE AREA. MODELS SHOWING THE
CLOSED LOW OPENING/PHASING WITH THE NORTHERN TROUGH WHICH ROTATES
INTO EASTERN WI BY THIS AFTERNOON. AS SUCH...WILL START OFF THIS
MORNING WITH CATEGORICAL -SN ALONG/EAST OF THE MISSISSIPPI RIVER
THROUGH 9 AM...THEN LIFTING THIS ALONG/NORTH OF I-94 AFTER 9 AM.
LOOKS LIKE PERHAPS UP TO ANOTHER HALF INCH OF SNOWFALL WILL BE
POSSIBLE ALONG AND EAST OF THE MISSISSIPPI RIVER THROUGH THIS
MORNING BEFORE MIXING WITH RAIN AS TEMPERATURES WARM. WILL HAVE TO
CONTINUE A CLOSE WATCH ON THESE PRECIPITATION TRENDS AND MAKE
ADJUSTMENTS AS NECESSARY THROUGH THIS MORNING.OTHERWISE...A FAIRLY
DECENT PRESSURE GRADIENT WILL EXIST ACROSS THE AREA TODAY ALONG WITH
MIXING TO AROUND 875MB. THIS WILL PRODUCE BREEZY WEST WINDS THROUGH
THE DAY WITH GUST AROUND 30 MPH ACROSS THE WIND PRONE AREAS OF
NORTHEAST IA/SOUTHEAST MN AND THE BLUFF TOPS OF SOUTHWEST WI.
TEMPERATURES TODAY EXPECTED TO TOP OFF IN THE MID 30S TO LOWER
40S.
LINGERING CYCLONIC FLOW WILL CONTINUE TO PRODUCE A CHANCE OF -SN
ACROSS CLARK/TAYLOR COUNTIES TONIGHT. NOT EXPECTING MUCH IN THE WAY
OF ACCUMULATION...PERHAPS A FEW TENTHS OF AN INCH. ACROSS THE REST
OF THE AREA...SOME CLEARING EXPECTED AS A WEAK RIDGE OF HIGH
PRESSURE MOVES INTO THE UPPER MISSISSIPPI RIVER REGION FROM THE
NORTHERN PLAINS.
REST OF THE PERIOD WILL SEE NORTHWEST FLOW AND A SLOWLY DEEPENING
TROUGH ACROSS THE CENTRAL CONUS/UPPER MISSISSIPPI RIVER REGION.
SURFACE CYCLOGENESIS IN RESPONSE TO DEEPENING TROUGH ALOFT MOVES
FROM THE NORTHERN PLAINS TOWARD THE REGION WEDNESDAY
AFTERNOON/NIGHT. NAM SHOWING FAIRLY STRONG LIFT ON THE 285K SURFACE
AHEAD OF THE WAVE GOING INTO WEDNESDAY NIGHT. BASED ON THIS
SIGNAL...BUMPED PRECIPITATION CHANCES UP TO 50 PERCENT WEDNESDAY
NIGHT. PRECIPITATION EXPECTED TO BE A RAIN/SNOW MIX DURING THE DAY
WEDNESDAY AS TEMPERATURES WARM INTO THE MID 30S TO LOWER 40S...THEN
TRANSITION TO ALL SNOW WEDNESDAY NIGHT AS THE COLUMN COOLS. COULD
PICK UP SOME LIGHT SNOW ACCUMULATIONS AS WELL...PERHAPS A HALF TO
ONE INCH. RAIN/SNOW CHANCE WILL CONTINUE THURSDAY/THURSDAY NIGHT AS
THE SURFACE LOW PRESSURE MOVES OUT OF WI INTO THE GREAT LAKES
REGION...BUT INVERTED SURFACE TROUGH/MID-LEVEL TROUGH LINGERS OVER
THE AREA. AGAIN...PRECIPITATION WILL LIKELY BE A RAIN/SNOW MIX
DURING THE DAY THURSDAY AS SURFACE TEMPERATURES WARM INTO THE
MIDDLE/UPPER 30S...THEN TRANSITION BACK TO ALL SNOW THURSDAY NIGHT
WITH COOLING.
.LONG TERM...FRIDAY THROUGH MONDAY
312 AM CST TUE FEB 21 2012
BOTH THE 21.00Z GFS AND ECMWF SHOW COOLER CYCLONIC FLOW LINGERING
ACROSS THE AREA THROUGH FRIDAY FOR A CHANCE OF SNOW. LOOKS LIKE
SATURDAY WILL BE DRY AS A FAIRLY STRONG RIDGE OF HIGH PRESSURE
BUILDS INTO THE REGION. GFS AND ECMWF THEN DRIFT OUT OF PHASE WITH
EACH OTHER THROUGH THE REMAINDER OF THE PERIOD..LENDING TO DECREASED
FORECAST CONFIDENCE IN THE SUNDAY/MONDAY PERIOD. THE GFS WANTS TO
PRODUCE STRONG CYCLOGENESIS OVER THE PLAINS SATURDAY NIGHT...THEN
TAKES THE DEEPENING LOW RAPIDLY NORTHEAST TOWARD THE SOUTHERN WI BY
SUNDAY AFTERNOON....AND THEN INTO THE GREAT LAKES REGION ON MONDAY.
THIS WOULD SUGGEST THE POTENTIAL FOR HEAVY SNOW FOR THE AREA SUNDAY.
THE ECMWF ON THE OTHER HAND DIGS THE MID-LEVEL TROUGH ACROSS THE
INTERMOUNTAIN WEST...EJECTING A DEEP SURFACE LOW INTO MN SUNDAY
NIGHT/MONDAY. THIS WOULD SUGGEST WARMER/RAIN SCENARIO FOR THE AREA.
SO...TIMING AND PRECIPITATION TYPE REMAINS HARD TO PINPOINT. AS A
RESULT...WILL CONTINUE WITH MODEL CONSENSUS APPROACH FOR NOW.
&&
.AVIATION...THROUGH 06Z WEDNESDAY
1136 PM CST MON FEB 20 2012
THE BAND OF SNOW IS MOVING QUICKLY ACROSS THE FORECAST AREA THIS
EVENING AND IS SMALLER IN AREAL COVERAGE THAT PREVIOUSLY EXPECTED.
GROUND TRUTH REPORTS INDICATE THE SNOW HAS TAPERED OFF TO JUST
FLURRIES AT KAUM AND BASED ON RADAR...EXPECT THIS TO HAPPEN
SHORTLY AS KRST AS WELL. THE SNOW SHOULD CONTINUE FOR A COUPLE
MORE HOURS AT KLSE BEFORE STARTING TO DIMINISH AS WELL. THE SNOW
MAY NOT COMPLETELY END AT KLSE UNTIL AFTER 12Z THOUGH AS THE UPPER
LEVEL LOW OVER NORTHWEST MISSOURI LIFTS TOWARD NORTHERN ILLINOIS.
BOTH THE 21.00Z NAM AND 21.03Z RUC SHOW THE LIGHT SNOW CONTINUING
ALONG THE SURFACE TROUGH AS THE UPPER LEVEL LOW LIFTS OUT AND THE
SURFACE TROUGH IS NOT EXPECTED TO MOVE EAST OF THE MISSISSIPPI
RIVER UNTIL ABOUT 12Z. CONFIDENCE IN THE SCENARIO IS NOT HIGH
BASED ON DOWNSTREAM RADARS AND WOULD NOT BE SURPRISED IF THE SNOW
TOTALLY ENDS AT KLSE WELL BEFORE 12Z. THE WIND WILL COME AROUND TO
THE WEST BEHIND THE PASSAGE OF THE SURFACE TROUGH AND WITH ENOUGH
MIXING...EXPECT THE VISIBILITY TO IMPROVE TO VFR ONCE THE SNOW
ENDS. ENOUGH MIXING EXPECTED TO OCCUR TUESDAY AFTERNOON FOR GUSTS
TO AROUND 25 KNOTS AT BOTH SITES. THE NAM SUGGESTS LOW LEVEL
MOISTURE WILL REMAIN TRAPPED UNDERNEATH THE LOW LEVEL INVERSION
AND KEEP CEILINGS IN THE MVFR RANGE THROUGH 06Z WEDNESDAY. THE
21.00Z GFS IS NOT AS PESSIMISTIC AND DEVELOPS VFR CEILINGS TUESDAY
AFTERNOON. UPSTREAM CONDITIONS OVER WESTERN MINNESOTA LENDS MORE
SUPPORT TO THE NAM SO HAVE STAYED WITH MVFR CEILINGS THROUGH THE
PERIOD ONCE THE SNOW ENDS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
312 AM CST TUE FEB 21 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM... DAS
LONG TERM.... DAS
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1136 PM CST MON FEB 20 2012
.SHORT TERM...TONIGHT THROUGH THURSDAY
250 PM CST MON FEB 20 2012
FORECAST CONCERNS FOCUS ON THE SNOW FOR TONIGHT...THEN ADDITIONAL
CHANCES THROUGH THE REST OF THE WEEK.
LATEST WATERVAPOR SATELLITE IMAGERY PAINTS A SHORTWAVE DIGGING
ACROSS THE SOUTHERN PLAINS WHILE 88-D RADAR RETURNS DEPICTED A
BROAD...ELONGATED REGION OF PCPN RUNNING ACROSS THE WESTERN PORTIONS
OF MN/IA.
20.12Z GFS AND NAM IN GOOD AGREEMENT WILL DRIVING THIS SHORTWAVE
OVER NORTHERN ILL BY 12Z TUE...LIFTING IT OVER THE EASTERN GREAT
LAKES LATER IN THE DAY AS ANOTHER PIECE OF UPPER LEVEL ENERGY DROPS
ACROSS NORTHERN PORTIONS OF THE REGION. THE STRONGEST AND DEEPEST QG
CONVERGENCE CONTINUES TO BE CO-LOCATED WITH THE UPPER LEVEL
ENERGY...JUST SOUTH OF THE FORECAST AREA. SOME 2-D FRONTOGENETIC
FORCING INDICATED ALONG A SFC BOUNDARY THAT EXTENDING NORTH OF SFC
LOW ASSOCIATED WITH THE MAIN SHORTWAVE...TO ANOTHER LOW LOCATED
WITH THE NORTHERN BIT OF ENERGY. GOOD ISENTROPIC UPGLIDE ON THE
275-295 K SFC OUT AHEAD OF THE BOUNDARY. 40 KT 850 MB LOW LEVEL JET
WILL NOSE INTO THE AREA TONIGHT...HELPING PUSH PWS UP TO AROUND 1/2
INCH...OVER 150 PERCENT OF NORMAL. SO...LOOK FOR THE BANDS OF PCPN
TO THE WEST TO TRANSITION ACROSS THE REGION TONIGHT...GRADUALLY
EXITING NORTHEAST ON TUE.
AS FOR WHAT WILL FALL...BUFKIT SOUNDINGS SUGGEST PERHAPS A BRIEF MIX
OF RAIN/SNOW INITIALLY TO THE WEST...BUT WITH SATURATION FROM
TOP DOWN AND TIMING OF THE PCPN...ANY RAINFALL WOULD QUICKLY GIVE
WAY TO ALL SNOW. SNOW CONTINUES TONIGHT INTO TUESDAY MORNING. ON THE
BACKSIDE OF THE EXITING SYSTEM SOUNDINGS AND WEST-EAST RUNNING
X-SECTIONS SHOW A SHALLOWING OUT OF THE MOISTURE...WHICH COULD
REMOVE ICE FROM THE CLOUDS. IF THERE IS LIFT THROUGH THESE CLOUDS
FREEZING DRIZZLE/DRIZZLE COULD OCCUR FOR A COUPLE HOURS. WILL LEAVE
THIS POTENTIAL OUT OF THE FORECAST FOR NOW...BUT THE POTENTIAL IS
THERE...AND TRENDS WILL HAVE TO BE MONITORED AND ADJUSTMENTS MADE TO
THE FORECAST IF THESE CHANCES INCREASE.
AS FOR HOW MUCH SNOW WILL FALL...BUFKIT SOUNDINGS STILL SHOW A
STRONG AMOUNT OF OMEGA THROUGH THE DENDRITIC GROWTH ZONE...BUT THIS
REGION REMAINS FAIRLY SMALL. IT ALSO REMAINS FAIRLY WARM...ABOVE -5
C FOR THE BOTTOM 6 KFT...SUGGESTING A WET/HEAVY SNOW...THUS LEANING
TOWARD LOWER SNOW RATIOS. WILL HOVER IN THE 10-14 TO 1 RATIOS FOR
NOW...WHICH IS HOW COBB OUTPUT SUGGESTS MOST OF THE SNOW WILL FALL.
1 TO 3 INCHES STILL LOOKS GOOD FOR TOTALS...WITH THE HIGHER AMOUNTS
WEST OF THE MISSISSIPPI RIVER. ISOLATED 4 INCH AMOUNTS CAN/T BE
RULED OUT. WILL NOT AN ISSUE AND ADVISORY AT THIS TIME...BUT IF
THOSE 4 INCH AMOUNTS BECOME WIDESPREAD...AN ADVISORY WILL BE NEEDED.
ON WED NIGHT/THU...BOTH THE GFS AND NAM WANT TO BRING A SHORTWAVE
TROUGH ACROSS NORTHERN PORTION OF THE REGION...WITH ANOTHER STRONGER
PIECE OF ENERGY JUST SOUTH OF THAT...SPINNING ACROSS SOUTHERN MN/IA.
THE SOUTHERN SHORTWAVE WILL HAVE A BETTER SHOT AT PRODUCING
PCPN...AND BOTH MODELS DO LAY DOWN A STRIPE OF QPF. THERE IS SOME
VARIANCE IN TIMING AND POSITIONING...BUT THE FORECAST AREA WOULD BE
AFFECTED. TIMING IS IMPORTANT AS TEMPS SHOULD CLIMB ABOVE FREEZING
THU...LEADING TO RAIN OR A RAIN/SNOW MIX. AT THIS TIME...ABOUT 1/2
TO 1 INCH OF SNOW APPEARS POSSIBLE.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY
250 PM CST MON FEB 20 2012
UPPER LEVEL FLOW LOOKS A BIT MORE ACTIVE COMPARED TO RECENT WEEKS
WITH BITS OF SHORTWAVE ENERGY SPINNING ACROSS THE REGION.
HOWEVER...GFS AND ECMWF APPEAR OUT OF PHASE WITH EACH OTHER AT
TIMES...KEEPING FORECAST CONFIDENCE LOW ON TIMING OF ANY OF THESE
POTENTIAL PCPN MAKERS. ONE THING THEY DO AGREE ON IS THE POTENTIAL
FOR SOME LIGHT SNOW THU NIGHT/FRI...POST AN EXITING SHORTWAVE
TROUGH...ASSOCIATED WITH AN INVERTED SFC TROUGH AND CYCLONIC FLOW A
LOFT. SUN-MON ALSO LOOKS LIKE PCPN WILL BE LIKELY...BUT WHAT...HOW
MUCH AND WHERE IS DIFFICULT TO PINPOINT. WILL LEAN HEAVILY ON THE
CONSENSUS SOLUTION FOR NOW.
&&
.AVIATION...THROUGH 06Z WEDNESDAY
1136 PM CST MON FEB 20 2012
THE BAND OF SNOW IS MOVING QUICKLY ACROSS THE FORECAST AREA THIS
EVENING AND IS SMALLER IN AREAL COVERAGE THAT PREVIOUSLY EXPECTED.
GROUND TRUTH REPORTS INDICATE THE SNOW HAS TAPERED OFF TO JUST
FLURRIES AT KAUM AND BASED ON RADAR...EXPECT THIS TO HAPPEN
SHORTLY AS KRST AS WELL. THE SNOW SHOULD CONTINUE FOR A COUPLE
MORE HOURS AT KLSE BEFORE STARTING TO DIMINISH AS WELL. THE SNOW
MAY NOT COMPLETELY END AT KLSE UNTIL AFTER 12Z THOUGH AS THE UPPER
LEVEL LOW OVER NORTHWEST MISSOURI LIFTS TOWARD NORTHERN ILLINOIS.
BOTH THE 21.00Z NAM AND 21.03Z RUC SHOW THE LIGHT SNOW CONTINUING
ALONG THE SURFACE TROUGH AS THE UPPER LEVEL LOW LIFTS OUT AND THE
SURFACE TROUGH IS NOT EXPECTED TO MOVE EAST OF THE MISSISSIPPI
RIVER UNTIL ABOUT 12Z. CONFIDENCE IN THE SCENARIO IS NOT HIGH
BASED ON DOWNSTREAM RADARS AND WOULD NOT BE SURPRISED IF THE SNOW
TOTALLY ENDS AT KLSE WELL BEFORE 12Z. THE WIND WILL COME AROUND TO
THE WEST BEHIND THE PASSAGE OF THE SURFACE TROUGH AND WITH ENOUGH
MIXING...EXPECT THE VISIBILITY TO IMPROVE TO VFR ONCE THE SNOW
ENDS. ENOUGH MIXING EXPECTED TO OCCUR TUESDAY AFTERNOON FOR GUSTS
TO AROUND 25 KNOTS AT BOTH SITES. THE NAM SUGGESTS LOW LEVEL
MOISTURE WILL REMAIN TRAPPED UNDERNEATH THE LOW LEVEL INVERSION
AND KEEP CEILINGS IN THE MVFR RANGE THROUGH 06Z WEDNESDAY. THE
21.00Z GFS IS NOT AS PESSIMISTIC AND DEVELOPS VFR CEILINGS TUESDAY
AFTERNOON. UPSTREAM CONDITIONS OVER WESTERN MINNESOTA LENDS MORE
SUPPORT TO THE NAM SO HAVE STAYED WITH MVFR CEILINGS THROUGH THE
PERIOD ONCE THE SNOW ENDS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
250 PM CST MON FEB 20 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM... RIECK
LONG TERM.... RIECK
AVIATION...04
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1030 PM CST MON FEB 20 2012
.UPDATE...
LITTLE DIFFERENCE IN NEW 00Z NAM. HRRR TRIES TO SPLIT THE AREAS OF
PRECIPITATION WITH ONE AREA JUST TO THE SOUTH OF THE ILLINOIS
BORDER...AND A SECOND BRUSHING THE FAR NORTHWEST SECTIONS TOWARD
MARQUETTE COUNTY. STILL SOME LIGHT QPF IN BETWEEN. DID NOT CHANGE
FORECAST WITH MOST AREAS GETTING AN INCH OR LESS. LOCALIZED 1.5
INCH AMOUNTS STILL POSSIBLE. OTHER PROBLEM IS SOME RAIN/SNOW MIX
POSSIBLE WITH THE ONSET OF PRECIPITATION DUE TO WARMER BOUNDARY
LAYER.
&&
.AVIATION/06Z TAFS/...
EXPECT A BAND OF PRECIPITATION TO LOWER CIGS/VSBYS TO IFR AS IT
PUSHES SLOWLY EAST DURING THE EARLY MORNING HOURS. A RAIN SNOW MIX
TO BEGIN THEN MAINLY SNOW. ACCUMULATIONS MAINLY AN INCH OR LESS.
IFR CIGS TO CONTINUE THROUGH THE MORNING THEN BECOME MVFR/VFR
TUESDAY AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 331 PM CST MON FEB 20 2012/
VERY SHORT TERM...TONIGHT AND TUESDAY. CONFIDENCE...MEDIUM.
WATER VAPOR/RUC COMBO SHOWS MAIN CIRCULATION CENTER SPINNING ACROSS
THE CENTRAL PLAINS. THIS WAVE PROGGD TO TAKE ON A NEGATIVE TILT AND
HEAD INTO CENTRAL ILLINOIS BY 12Z. WARM ADVECTION AND MOIST
SOUTHERLY FLOW WILL CONTINUE OUT AHEAD OF THE 850 MILLIBAR TROUGH
AXIS. DRY AIR TO HAVE A HOLD ON THE AREA UNTIL AFTER 6Z WHEN
MOISTURE AND VERTICAL MOTION INCREASE INTO THE WESTERN CWA. A LOT OF
THE BETTER LOW LEVEL Q-VECTOR CONVERGENCE AND UPPER DIVERGENCE
COINCIDE ACROSS SRN WI AROUND 6Z...AND THEN SHIFT EAST AS THE NIGHT
WEARS ON. SO SOME OF THE BETTER FORCING PARAMETERS ARE OUTRACING THE
MOISTURE/PRECIP WITH THIS SYSTEM. THE 700-300 MILLIBAR Q-VOECTOR
CONVEREGNCE DOES SHOW BETTER FORCING FROM 6-14Z...WITH THE BETTER
LIFT IN SOUTHERN WI. THOUGH BULK OF BETTER Q-VECTOR ACTION SHOWING
UP TO OUR SOUTH AND SOUTHEAST. BUFKIT DOES SHOW GOOD SATURATION FROM
LATE TONIGHT THROUGH MID MORNING TUESDAY. BEST FORCING NOTED OUTSIDE
THE FAVORED DENDRIDIC GROWTH ZONE. WILL GO WITH AN INCH OR LESS FOR
TOTAL ACCUMS AS COMBO OF QPF WITH NAM/GFS RATIOS AND THICKNESS
TECHNIQUE SUGGEST. ONCE TROUGH SHIFTS EAST...DECENT WESTERLY WIND
SETS UP WITH GRADIENT TIGHTENING. BUFKIT SUGGESTS MIXING OF SOME
GUSTS OVER 20 TUESDAY AFTERNOON. TEMPS SHOULD REACH ALLBLEND LEVELS
IN THE LOW 40S.
SHORT TERM...TUESDAY NIGHT THROUGH THURSDAY NIGHT.
TUESDAY NIGHT AND WEDNESDAY...FORECAST CONFIDENCE MEDIUM.
PRECIPITATION ENDS BY TUESDAY EVENING WITH SUBSIDENCE AND DRYING.
STEEP LOW-LEVEL LAPSE RATES TUESDAY EVENING AS POCKET OF COLDER
DRIER AIR WORKS UNDER LOW. MOSTLY CLOUDY OVERNIGHT WITH SOME
MOISTURE CONVERGENCE ON THE LEADING EDGE OF THE COLD AIR...BUT NOT
ENOUGH FOR PRECIPITATION. MID UPPER 20S FOR LOWS.
DRY THROUGH WEDNESDAY MORNING...WITH A SLIGHT CHANCE OF RAIN IN THE
AFTERNOON WITH WARM AIR ADVECTION AHEAD OF NEXT SHORT WAVE. 925MB
TEMPERATURES SUPPORT HIGHS IN THE UPPER 30S TO AROUND 40 NORTH...AND
LOWER TO MID 40S SOUTH.
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...FORECAST CONFIDENCE LOW TO
MEDIUM.
TIMING...STRUCTURE AND STRENGTH OF SHORT WAVES AND ASSOCIATED
SURFACE FEATURES LEAD TO UNCERTAINTY WITH LOCATION AND AMOUNTS OF
ANY PRECIPITATION THIS PERIOD. WILL TRY TO HIGHLIGHT MORE/LESS
PROBABLE PRECIPITATION PERIODS WITH HIGHER/LOWER CONSENSUS
POPS...BUT WITH UNCERTAINTY WILL NOT BE ABLE TO KEEP ANY PARTICULAR
12-HOUR TIME PERIOD DRY.
BASED ON FORECAST SOUNDINGS...ANY PRECIPITATION THAT DOES DEVELOP
WEDNESDAY EVENING COULD START AS RAIN AS MAXIMUM TEMPERATURES IN THE
WARM LAYER BETWEEN 950-925MB ARE 2-3C AND WET BULB TEMPERATURE IS
ABOVE 0C...EVEN ON THE COOLER NAM. HOWEVER...WARM LAYER IS
RELATIVELY SHALLOW AND COULD RAPIDLY DISAPPEAR AS EVAPORATIVE
COOLING DROPS AIR AND WET BULB TEMPERATURES...SO WILL GO WITH A
RAIN/SNOW MIX GOING OVER TO ALL SNOW AS ENTIRE COLUMN COOLS TO BELOW
0C BY/SHORTLY AFTER MIDNIGHT.
SIMILAR SCENARIO WITH PRECIPITATION TYPE THURSDAY INTO THURSDAY
NIGHT...WITH DAYTIME WARMING AND WARM ADVECTION AHEAD OF NEXT SHORT
WAVE CHANGING SNOW TO A RAIN/SNOW MIX FROM MID TO LATE MORNING...AND
ALL RAIN EXCEPT FOR A CONTINUED MIX IN THE NORTHERN CWA IN THE
AFTERNOON...THEN CHANGING BACK TO A MIX EARLY IN THE EVENING THEN
ALL SNOW WITH COLD AIR ADVECTION BEHIND WAVE.
LONG TERM...FRIDAY THROUGH MONDAY. FORECAST CONFIDENCE...LOW.
ABOUT THE ONLY CONSISTENT SIGNAL FROM THE MODELS IS A DRY PERIOD
FROM FRIDAY NIGHT THROUGH SATURDAY. BEYOND THIS PERIOD...MODELS HAVE
BEEN HIGHLY VARIABLE THAT PAST FEW DAYS WITH STRUCTURE AND TIMING OF
STRONG SHORT WAVE AND ASSOCIATED SURFACE LOW EJECTING FROM DEEPENING
WESTERN TROUGH IN THE SUNDAY/MONDAY TIME FRAME. A CONSENSUS BLEND OF
00Z AND 12Z RUNS LEANS TOWARD...BUT IS A BIT SLOWER THAN...THE
CURRENT 12Z/20 GFS RUN THAT TAKES A CLOSED SURFACE LOW ALONG A
PRAIRIE DU CHIEN TO LUDINGTON MI PATH LATE SUNDAY AFTERNOON/SUNDAY
NIGHT. THIS WOULD PUT THE HEAVIEST PCPN ACROSS CENTRAL WISCONSIN AND
POSSIBLY CLIP OUR NORTHERN COUNTIES. 12Z ECMWF HAS AN INVERTED
SURFACE TROUGH NOSING INTO THE SOUTH AT 12Z MONDAY AND LINGERING
THROUGH TUESDAY MORNING FOR A PROLONGED PERIOD OF PCPN. STAY TUNED
FOR THE LATEST DEVELOPMENTS AS MODELS WILL REMAIN VARIABLE UNTIL
HOPEFULLY LOCKING ON A MORE CONSISTENT SOLUTION IN THE NEXT FEW DAYS.
AVIATION/00Z TAFS/...VFR CONDITIONS EXPECTED WELL INTO THE EVENING
HOURS WITH GRADUALLY THICKENING MID DECK. LOWER CLOUD COVER
INCREASES LATER TONIGHT AS INFLUENCE OF CENTRAL PLAINS SHORTWAVE AND
ASSOCIATED MOISTURE DRAWS CLOSER. PROGS STILL IN DECENT AGREEMENT
WITH BRINGING LIGHT SNOW ACROSS SOUTHERN WI AFTER MIDNIGHT AND INTO
TUESDAY MORNING. THIS WILL LEAD TO AREAS OF IFR CEILINGS/VSBYS. SOME
IMPROVEMENT EXPECTED FOR THE AFTERNOON AS WINDS TURN MORE WESTERLY
IN THE WAKE OF THE TROUGH.
MARINE...TIGHTENING PRESSURE GRADIENT WILL CONTINUE TO DEVELOP OVER
LAKE MICHIGAN AS HIGH PRESSURE PUSHES FARTHER TO THE EAST WHILE LOW
PRESSURE STRENGTHENS OVER THE CENTRAL AND NORTHERN PLAINS. WILL
ALLOW SMALL CRAFT TO EXPIRE TUESDAY MORNING...BUT MAY NEED TO BE
REISSUED TUESDAY AFTERNOON INTO TUESDAY EVENING AS PRESSURE GRADIENT
RETIGHTENS AND WINDS INCREASE BEHIND SURFACE LOW PRESSURE TROUGH.
THIS TROUGH WILL BE MOVING ACROSS LAKE MICHIGAN TUESDAY MORNING
RESULTING IN THE TEMPORARY LULL IN WIND SPEEDS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 9 AM CST TUESDAY FOR LMZ643>646.
&&
$$
UPDATE...HENTZ
TONIGHT/TUESDAY AND AVIATION/MARINE...COLLAR
TUESDAY NIGHT THROUGH MONDAY...REM
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
425 AM EST THU Feb 23 2012
.SYNOPSIS...
08Z water vapor and H4 RUC analysis shows a northern stream pattern
consisting of broad troughing from the inter-mountain west to the
eastern seaboard. A series of disturbances diving southeastward
along the western periphery of this trough will act to amplify the
flow into the central and eastern CONUS over the next 24 hours to 36
hours. As was finally agreed upon by the global guidance last night,
a cutoff low spinning over the Mexican Baja region is not being
picked up by this amplifying trough, and will not move east to
influence our regions weather until the second half of the upcoming
weekend. More on this in the long term discussion below. A fast
southern stream flow remains aligned along the northern Gulf Coast
this morning. A weak mid-level impulse over eastern Texas analyzed
by both the GFS/ECMWF and seen by WV drying/subsidence will rapidly
be advected eastward toward and over our region today.
At the surface, forecast area is situated in a region of SW flow
between a high pressure ridge over south FL/FL straits, and
organizing low pressure across the Central Plains. Very warm
overnight period underway with the flow off the Gulf. Temperatures
as of 4AM EST are still in the middle 60s to around 70 at most
stations with dewpoint just a few degrees lower.
&&
.SHORT TERM (Today through Saturday)...
Today, A warm and humid day for late February on tap. Deep southwest
flow off the Gulf of Mexico will continue to pump abundant low level
moisture into the region. GFS/ECMWF both show 850mb temps rising to
around 15C this afternoon. Model forecast sounding suggest that we
will mix to between 900 and 850mb by the end of the day...away from
the coast. This degree of mixing will result in temperatures pushing
10 degrees above average this afternoon with many inland stations
topping out in the upper 70s to around 80. With enough sunny breaks
lasting into the afternoon, would not be surprised to see a few
lower 80s north of the I-10 corridor. As mentioned in the
synopsis...a weak impulse will be quickly sliding along the northern
Gulf coast and past our region by early this evening. With the
abundant moisture...and some weak synoptic lift ahead of this
impulse, a few isolated showers or thunderstorms can not be
completely ruled out this afternoon. Will add a slight 20% PoP for
the Big Bend and South-Central GA zones to account for this
possibility.
Have issued a wind advisory from 17-00Z today away from the coast
for all zones along and north of the I-10 corridor. Due to the
degree of diurnal mixing...expect to tap into stronger winds just a
bit above the surface by around the midday hour. Sustained winds of
15 to 20 mph look likely, and BUFKIT sounding/WRF algorithms both
suggest gusts to 30 mph will be possible along the I-10 corridor and
possibly over 30 mph north of the FL border. While it will still be
breezy closer to the coast, a less well mixing boundary layer off
the cooler shelf waters should prevent wind advisory criteria from
being met.
Tonight,
Upper trough will continue to amplify over the central CONUS and
push eastward. Associated with this feature, a surface cold front
will also move east and be approaching our western zones toward
sunrise. A few showers or storms along this front will be possible
very late tonight...generally to the west of Dothan. Appears now,
that this will be mostly an anafront configuration, with the
majority of the shower activity occurring in the wake of the frontal
passage. If we can get a storm or 2 ahead of the front, then shear
profiles will be sufficient for organized updrafts and at least some
wind threat. At this point the threat for severe weather appears
minimal, but will continue to monitor. Elsewhere for the rest of the
forecast area, expect a generally dry and warm overnight period.
Friday/Friday Night, Surface cold front will push from NW to SE
across the area during the day. Still some small disagreements on
timing between the global models with the ECMWF about 6 hours slower
than the GFS. Either way, expect a scattering of showers and
isolated thunderstorms to work southeastward along and behind the
front through the day. Doesn`t look like a "washout", but those with
outdoor plans should anticipate dodging a few rain drops. A
continued anafront configuration appears likely which will help
suppress the threat of severe weather. Lingering showers over the
eastern zones Friday Evening will slowly end allowing a cooler and
much drier airmass to arrive by Saturday morning.
Saturday, Appears we will salvage one of the weekend days with some
decent weather. High pressure and a dry low level airmass will keep
our forecast rain-free with highs generally in the lower to mid 60s.
Morning sunshine will likely become quickly filtered by increasing
high clouds during the afternoon as our next potential rain maker
quickly organizes and moves our way for Sunday.
&&
.LONG TERM (Sunday through next Thursday)...
All guidance has now come in line with the GFS with the motion of
the upper low currently near the Baja. This low will slide east
across Mexico through Saturday before being picked up by the main
belt of westerlies and ejecting towards the central gulf coast. As
this system ejects, it will generate a broad area of isentropic
ascent as the warm and moist mid-level flow overrides a cool
low-level airmass. Will be ramping up PoPs significantly for late
Saturday night into Sunday with the new forecast. Cool wedge on
Sunday will be maintained by 1030mb high over the Carolinas. This
should provide a nice feed of relatively dry low-level air into the
region throughout the day, keeping temperatures from rising
significantly. Will undercut the MEX Mos for Sunday, since it is
unlikely to handle the wedge sufficiently.
Main piece of upper energy will exit to the northeast by Monday.
However, with high pressure still in place over the mid-Atlantic and
southerly low- to mid-level winds across the forecast area, still
may see scattered isentropically forced showers across the region
for Monday. Weather appears to remain a bit unsettled on Tuesday
with fast upper flow still in place and enough low-level moisture
that an isolated shower or two cannot be ruled out. A more
significant chance of rain may appear by Wednesday as passing
shortwave pushes a front into the deep south.
&&
.AVIATION..(thru 06Z Thursday)
Plenty of low clouds advecting
across the region this morning on decent southwesterly winds. The
winds should help keep Cigs just above airport mins and keep Vsby up
as well. A windy day is on tap at all terminals today with wind
gusts around 30 knot at KDHN and KABY. Otherwise, should see VFR
conditions this afternoon before MVFR and IFR Cigs return after
sunset tonight.
&&
.MARINE...
A persistent southwest flow will continue through tonight between
high pressure centered east of the Florida Peninsula, and a slowly
approaching cold front to our west. Winds are expected to increase
to cautionary levels this afternoon and continue into the day on
Friday. The cold front will then cross the forecast waters during
the day on Friday shifting winds northerly from west to east. A
period of advisory level winds and seas is anticipated in the wake
of this front Friday night through at least Saturday morning. The
gradient looks to remain tight with elevated winds through the
weekend as weak low pressure develops in the western Gulf and slowly
approaches the region.
&&
.Fire Weather...
Low-level moisture will remain plentiful through Friday ahead of an
approaching cold front. A much drier air mass will spill into the
region on Saturday with RH values falling into the 20s. Moisture and
rain is now expected to quickly return to the area by Sunday into
early next week.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 78 65 69 44 63 / 20 10 60 30 0
Panama City 75 65 67 44 62 / 10 10 70 30 10
Dothan 79 62 63 39 62 / 10 20 70 20 0
Albany 81 66 66 39 62 / 10 10 70 20 0
Valdosta 80 65 71 43 62 / 20 10 60 30 0
Cross City 77 62 75 47 66 / 20 10 60 40 10
Apalachicola 70 66 70 46 62 / 20 10 60 30 10
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...Wind Advisory from 11 AM this morning to 6 PM CST this evening
for Coffee-Dale-Geneva-Henry-Houston.
GA...Wind Advisory from Noon today to 7 PM EST this evening 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.
FL...Wind Advisory from Noon EST /11 AM CST/ today to 7 PM EST /6 PM
CST/ this evening for Calhoun-Gadsden-Holmes-Inland
Jefferson-Inland Walton-Jackson-Leon-Liberty-Madison-
Washington.
GM...None.
&&
$$
SYNOPSIS/SHORT TERM/MARINE...MROCZKA
LONG TERM/AVIATION/FIRE WX...CAMP
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
400 AM EST THU FEB 23 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH FRIDAY. HIGH PRESSURE WILL BUILD
INTO THE AREA THIS WEEKEND.
&&
.NEAR TERM /TODAY/...
RADAR CURRENTLY INDICATES A FEW LINGERING SHOWERS OVER PORTIONS
OF THE FORECAST AREA. WILL EXPECT THIS ACTIVITY TO CONTINUE TO
GRADUALLY DISSIPATE BY DAYBREAK. LOW PRESSURE DEVELOPING OVER THE
MID MISS AND OHIO VALLEYS TODAY WILL PROVIDE BREEZY CONDITIONS FOR
OUR FA TODAY. WIND GUSTS AROUND 25 OR 30 MPH EXPECTED OVER LAND
AREAS THIS AFTERNOON...BUT WITH LESS MIXING OVER COOLER LAKE
WATERS...LAKE WIND ADVISORY (LWA) CONDITIONS MAY NOT BE MET ON
AREA LAKES. PER COORDINATION WITH CHS...HELD OFF ON LWA AGAIN
TODAY. SW WINDS PROVIDING WARM TEMPS. GENERALLY FORECASTING MAX
TEMPS NEAR 80 TODAY. RECORD HIGHS FOR TODAY ARE 82 AT CAE...AND 81
AT AGS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
DEEPER UPPER TROUGH WILL SHIFT ACROSS THE EASTERN CONUS. SURFACE LOW
PRESSURE WELL TO OUR NORTH WILL CONTINUE TO INTENSIFY AND MOVE
NE...DRAGGING A FRONT THROUGH OUR REGION FRIDAY. BEST UPPER
ENERGY TO REMAIN JUST TO OUR NORTH. STRONG MID TO LOW LEVEL JETS
EXPECTED ACROSS OUR REGION AGAIN THU NT INTO FRI AS THE FRONT
MOVES THROUGH...LEADING TO SVR POSSIBILITIES. SPC HAS REGION IN
SLIGHT RISK. MODELS MOVE FRONT OUT OF OUR REGION FRI EVENING.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
STILL LOTS OF UNCERTAINTY WITH THE FORECAST IN THE EXTENDED PERIOD
DUE TO MODEL INCONSISTENCIES. AS A RESULT...HAVE MADE FEW CHANGES
TO THE ONGOING FORECAST. CUT OFF UPPER LOW OVER BAJA CA WILL LIFT
OUT TO THE EAST OVER THE NEXT COUPLE OF DAYS. MODELS HAVE TIMING
DIFFERENCES. AT THE SURFACE...A COUPLE OF FRONTAL SYSTEMS WILL
BRING A CHANCE FOR RAIN DURING THE FIRST PART OF NEXT WEEK. LOW
CONFIDENCE WITH THE TIMING OF THESE WEATHER FEATURES...SO HAVE
MADE ONLY MINOR CHANGES TO THE LONG TERM FORECAST. TEMPERATURES
MAINLY CLOSE TO OR JUST ABOVE NORMAL DURING THE PERIOD.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
MOS GUIDANCE IS GIVING IFR CONDITIONS EARLY THIS MORNING NEAR
SUNRISE BUT LOW LEVEL WINDS HAVE INCREASE ACROSS THE REGION AND
SOME CONVECTION IS OCCURRING IN THE NORTHERN PART OF THE FORECAST
AREA. CONDITIONS ARE CURRENTLY VFR ACROSS THE AREA. WITH WINDS...
OPTED FOR MAINLY VFR CONDITIONS ALTHOUGH AN INCREASE IN LOW LEVEL
MOISTURE AHEAD AN APPROACHING COLD FRONT MAY BRING CIGS 3-4 KFT IN
BETWEEN 08Z-12Z THIS MORNING. THINK SOUTHWEST SURFACE WINDS 10-15
KNOTS WILL PROHIBIT FOG FORMATION. RUC MODEL SHOWS A WEAK SHORT
WAVE PASSING THROUGH 06Z-12Z TIME FRAME AS WELL. WILL INCLUDE
TEMPO GROUPS 08Z-10Z FOR MVFR CONDITIONS IN SHOWERS. BUT IT LOOKS
LIKE THE ACTIVITY WILL CLEAR THE REGION TO THE EAST 10Z-12Z TIME
FRAME. WITH INCREASED LOW LEVEL WINDS AT 2 KFT...DECIDED TO
MENTION LOW LEVEL WIND SHEAR ALL TAF STIES 06Z-10Z WITH 2 KFT WINDS
23040 KNOTS AND 24050 KNOTS DURING THE PERIOD. AFTER 10Z...THINK
STRONGER WINDS WILL MIX DOWN TO THE SURFACE AND WILL HAVE SOUTHWEST
WINDS 15-20 KNOTS FOR THE REST OF THE DAY. THE COLD FRONT WILL
APPROACH LATE THURSDAY NIGHT NEAR MIDNIGHT. THERE MAY BE SOME
SHOWERS OR THUNDERSTORMS BUT WILL NOT MENTION FOR TIME BEING DUE
TO TIMING ISSUES AND UNCERTAINTY TO COVERAGE.
EXTENDED AVIATION OUTLOOK...MVFR AND POSSIBLE IFR CONDITIONS MAY
OCCUR LATE THURSDAY NIGHT AND FRIDAY AS THE COLD FRONT PUSHES
THROUGH THE REGION. SOME THUNDERSTORMS MAY ALSO ACCOMPANY THE FRONT.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
236 AM EST THU FEB 23 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH FRIDAY. HIGH PRESSURE WILL BUILD
INTO THE AREA THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AREAL COVERAGE HAS DECREASED SOME...BUT A BAND OF SCATTERED
SHOWERS AND A FEW THUNDERSTOMS CONTINUES TO MOVE ESE ACROSS
PORTIONS OF THE CENTRAL AND NORTHERN FA. WILL EXPECT THIS ACTIVITY
TO CONTINUE TO MOVE ACROSS THE FA AND GRADUALLY DISSIPATE BY
DAYBREAK.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
DEEPER UPPER TROUGH WILL SHIFT ACROSS THE EASTERN CONUS. LOW
PRESSURE WILL DEVELOP OVER THE MISS VALLEY AND SHIFT NE AND
INTENSIFY...DRAGGING A FRONT THROUGH OUR REGION FRIDAY. BREEZY
CONDITIONS EXPECTED THU/FRI AHEAD OF THE FRONT. WIND GUSTS AROUND
25 MPH EXPECTED OVER LAND AREAS THIS AFTERNOON...BUT WITH LESS
MIXING OVER COOLER LAKE WATERS...LAKE WIND ADVISORY (LWA)
CONDITIONS MAY NOT BE MET ON AREA LAKES. PER COORDINATION WITH
CHS...HELD OFF ON LWA AGAIN TODAY. SW WINDS PROVIDING WARM TEMPS.
GENERALLY FORECASTING MAX TEMPS NEAR 80 TODAY. RECORD HIGHS FOR
TODAY ARE 82 AT CAE...AND 81 AT AGS. BEST UPPER ENERGY TO REMAIN
JUST TO OUR NORTH. STRONG MID TO LOW LEVEL JETS EXPECTED ACROSS
OUR REGION AGAIN THU NT INTO FRI AS THE FRONT MOVES THROUGH...LEADING
TO SVR POSSIBILITIES. SPC HAS REGION IN SLIGHT RISK. MODELS MOVE
FRONT OUT OF OUR REGION FRI EVENING.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
STILL LOTS OF UNCERTAINTY WITH THE FORECAST IN THE EXTENDED PERIOD
DUE TO MODEL INCONSISTENCIES. AS A RESULT...HAVE MADE FEW CHANGES
TO THE ONGOING FORECAST. CUT OFF UPPER LOW OVER BAJA CA WILL LIFT
OUT TO THE EAST OVER THE NEXT COUPLE OF DAYS. MODELS HAVE TIMING
DIFFERENCES. AT THE SURFACE...A COUPLE OF FRONTAL SYSTEMS WILL
BRING A CHANCE FOR RAIN DURING THE FIRST PART OF NEXT WEEK. LOW
CONFIDENCE WITH THE TIMING OF THESE WEATHER FEATURES...SO HAVE
MADE ONLY MINOR CHANGES TO THE LONG TERM FORECAST. TEMPERATURES
MAINLY CLOSE TO OR JUST ABOVE NORMAL DURING THE PERIOD.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
MOS GUIDANCE IS GIVING IFR CONDITIONS EARLY THIS MORNING NEAR
SUNRISE BUT LOW LEVEL WINDS HAVE INCREASE ACROSS THE REGION AND
SOME CONVECTION IS OCCURRING IN THE NORTHERN PART OF THE FORECAST
AREA. CONDITIONS ARE CURRENTLY VFR ACROSS THE AREA. WITH WINDS...
OPTED FOR MAINLY VFR CONDITIONS ALTHOUGH AN INCREASE IN LOW LEVEL
MOISTURE AHEAD AN APPROACHING COLD FRONT MAY BRING CIGS 3-4 KFT IN
BETWEEN 08Z-12Z THIS MORNING. THINK SOUTHWEST SURFACE WINDS 10-15
KNOTS WILL PROHIBIT FOG FORMATION. RUC MODEL SHOWS A WEAK SHORT
WAVE PASSING THROUGH 06Z-12Z TIME FRAME AS WELL. WILL INCLUDE
TEMPO GROUPS 08Z-10Z FOR MVFR CONDITIONS IN SHOWERS. BUT IT LOOKS
LIKE THE ACTIVITY WILL CLEAR THE REGION TO THE EAST 10Z-12Z TIME
FRAME. WITH INCREASED LOW LEVEL WINDS AT 2 KFT...DECIDED TO
MENTION LOW LEVEL WIND SHEAR ALL TAF STIES 06Z-10Z WITH 2 KFT WINDS
23040 KNOTS AND 24050 KNOTS DURING THE PERIOD. AFTER 10Z...THINK
STRONGER WINDS WILL MIX DOWN TO THE SURFACE AND WILL HAVE SOUTHWEST
WINDS 15-20 KNOTS FOR THE REST OF THE DAY. THE COLD FRONT WILL
APPROACH LATE THURSDAY NIGHT NEAR MIDNIGHT. THERE MAY BE SOME
SHOWERS OR THUNDERSTORMS BUT WILL NOT MENTION FOR TIME BEING DUE
TO TIMING ISSUES AND UNCERTAINTY TO COVERAGE.
EXTENDED AVIATION OUTLOOK...MVFR AND POSSIBLE IFR CONDITIONS MAY
OCCUR LATE THURSDAY NIGHT AND FRIDAY AS THE COLD FRONT PUSHES
THROUGH THE REGION. SOME THUNDERSTORMS MAY ALSO ACCOMPANY THE FRONT.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1250 AM EST THU FEB 23 2012
.SYNOPSIS...
AN UPPER DISTURBANCE AND SURFACE LOW MOVING BY TO OUR NORTH WILL
PROVIDE A CHANCE OF SHOWERS AND POSSIBLE THUNDERSTORMS...MAINLY
ACROSS THE NORTHERN HALF OF THE STATE TONIGHT. A COLD FRONT WILL
MOVE THROUGH FRIDAY. HIGH PRESSURE WILL BUILD INTO THE AREA THIS
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
RADAR INDICATES LINE OF SHOWERS AND A FEW THUNDERSTORMS STRETCHING
FROM CENTRAL NC SW ACROSS THE UPSTATE SC...APPROACHING OUR N
FA...AND SW INTO NE GA AND PORTIONS OF ALA. THE ACTIVITY
CONTINUES TO HOLD TOGETHER AND PROGRESS TO THE ESE. 00Z SPC WRF
AND LATEST VSREF INDICATING ACTIVITY TO TRAVERSE OUR FA OVERNIGHT.
UPPED THE POPS FOR THE OVERNIGHT PERIOD.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
DEEPER UPPER TROUGH WILL SHIFT ACROSS THE EASTERN CONUS. LOW
PRESSURE WILL DEVELOP OVER THE MS VALLEY AND SHIFT NE AND
INTENSIFY...DRAGGING A FRONT THROUGH OUR REGION FRIDAY. STRONG WAA
ON THURSDAY WILL DRIVE AFTERNOON TEMPS WELL INTO THE LOWER TO
MIDDLE 70S ACROSS MUCH OF THE AREA. BREEZY CONDITIONS EXPECTED
THU/FRI AHEAD OF THE FRONT. BEST UPPER ENERGY TO REMAIN JUST TO
OUR NORTH. CURRENT DAY TWO CONVECTIVE OUTLOOK HAS MUCH OF CWA IN
GENERAL TSTM AREA FOR FRIDAY. STRONG MID TO LOW LEVEL JETS EXPECTED
ACROSS OUR REGION AGAIN THU NT INTO FRI...SO AN ISOLATED
STRONG/BORDERLINE SVR STORM NOT OUT OF THE QUESTION. FEW OVERALL
CHANGES FROM PREVIOUS FORECAST. STILL QUITE A SPREAD IN GFS
ENSEMBLE POP NUMBERS. LATEST SREF POPS MAINLY IN THE CHANCE RANGE
LATE THU NT INTO FRI AFTN. IN GENERAL USED MODEL BLEND BETWEEN
GMOS AND ONGOING FORECAST FOR TEMPS AND POPS.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
STILL LOTS OF UNCERTAINTY WITH THE FORECAST IN THE EXTENDED PERIOD
DUE TO MODEL INCONSISTENCIES. AS A RESULT...HAVE MADE FEW CHANGES
TO THE ONGOING FORECAST. CUT OFF UPPER LOW OVER BAJA CA WILL LIFT
OUT TO THE EAST OVER THE NEXT COUPLE OF DAYS. MODELS HAVE TIMING
DIFFERENCES. AT THE SURFACE...A COUPLE OF FRONTAL SYSTEMS WILL
BRING A CHANCE FOR RAIN DURING THE FIRST PART OF NEXT WEEK. LOW
CONFIDENCE WITH THE TIMING OF THESE WEATHER FEATURES...SO HAVE
MADE ONLY MINOR CHANGES TO THE LONG TERM FORECAST. TEMPERATURES
MAINLY CLOSE TO OR JUST ABOVE NORMAL DURING THE PERIOD.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
MOS GUIDANCE IS GIVING IFR CONDITIONS EARLY THIS MORNING NEAR
SUNRISE BUT LOW LEVEL WINDS HAVE INCREASE ACROSS THE REGION AND
SOME CONVECTION IS OCCURRING IN THE NORTHERN PART OF THE FORECAST
AREA. CONDITIONS ARE CURRENTLY VFR ACROSS THE AREA. WITH WINDS...
OPTED FOR MAINLY VFR CONDITIONS ALTHOUGH AN INCREASE IN LOW LEVEL
MOISTURE AHEAD AN APPROACHING COLD FRONT MAY BRING CIGS 3-4 KFT IN
BETWEEN 08Z-12Z THIS MORNING. THINK SOUTHWEST SURFACE WINDS 10-15
KNOTS WILL PROHIBIT FOG FORMATION. RUC MODEL SHOWS A WEAK SHORT
WAVE PASSING THROUGH 06Z-12Z TIME FRAME AS WELL. WILL INCLUDE
TEMPO GROUPS 08Z-10Z FOR MVFR CONDITIONS IN SHOWERS. BUT IT LOOKS
LIKE THE ACTIVITY WILL CLEAR THE REGION TO THE EAST 10Z-12Z TIME
FRAME. WITH INCREASED LOW LEVEL WINDS AT 2 KFT...DECIDED TO
MENTION LOW LEVEL WIND SHEAR ALL TAF STIES 06Z-10Z WITH 2 KFT WINDS
23040 KNOTS AND 24050 KNOTS DURING THE PERIOD. AFTER 10Z...THINK
STRONGER WINDS WILL MIX DOWN TO THE SURFACE AND WILL HAVE SOUTHWEST
WINDS 15-20 KNOTS FOR THE REST OF THE DAY. THE COLD FRONT WILL
APPROACH LATE THURSDAY NIGHT NEAR MIDNIGHT. THERE MAY BE SOME
SHOWERS OR THUNDERSTORMS BUT WILL NOT MENTION FOR TIME BEING DUE
TO TIMING ISSUES AND UNCERTAINTY TO COVERAGE.
EXTENDED AVIATION OUTLOOK...MVFR AND POSSIBLE IFR CONDITIONS MAY
OCCUR LATE THURSDAY NIGHT AND FRIDAY AS THE COLD FRONT PUSHES
THROUGH THE REGION. SOME THUNDERSTORMS MAY ALSO ACCOMPANY THE FRONT.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...07
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
326 AM EST THU FEB 23 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A CHAOTIC WEATHER PATTERN FOR THE NEXT FEW DAYS WILL LEAD TO CHANCES
FOR RAIN...THUNDERSTORMS...AND SNOW OVER THE NEXT COUPLE OF DAYS.
QUIET WEATHER FOR THE WEEKEND WILL GIVE WAY TO LOW CHANCES FOR RAIN
OR SNOW EARLY IN THE WORK WEEK.
&&
.NEAR TERM /TONIGHT/...
EVENING UPDATE #2...THIN CONVECTIVE LINE HAS QUICKLY DEVELOPED
OVER SOUTHWEST INDIANA JUST SOUTH OF THE FORECAST AREA OVER THE
LAST 30-45 MINUTES. THIS APPEARS TO BE ALONG THE WEAK BOUNDARY
PROGRESSING THROUGH THE SOUTHERN PART OF THE FORECAST AREA.
MESOANALYSIS ALSO SHOWING THAT THIS AREA SITS RIGHT ON THE EDGE OF
THE INSTABILITY AXIS EXTENDING SOUTH INTO THE LOWER MISSISSIPPI
VALLEY. ALSO APPEARS TO HAVE SOME UPPER SUPPORT AIDING DEVELOPMENT
AS TROUGH AXIS ALOFT IS OVERHEAD. HRRR HAS A NICE HANDLE ON
CURRENT DEVELOPMENT...EXPANDING IT EAST ALONG THE OHIO RIVER
VALLEY THIS EVENING. HAVE INSERTED LOW CHANCE POPS OVER FAR
SOUTHERN COUNTIES TO ACCOUNT FOR NORTHERN PART OF THE LINE
CLIPPING SOUTHERN PORTIONS OF THE FORECAST AREA THROUGH THE
EVENING. ANY PRECIP SHOULD BE EAST OF THE FORECAST AREA BY
MIDNIGHT AS WEAK RIDGING BUILDS IN.
PREVIOUS DISCUSSION FOLLOWS.
QUICK UPDATE TO ADDRESS THE GUSTY WINDS PERSISTING ALONG AND AHEAD
OF A WEAK BOUNDARY. HAVE SEEN MAX WIND GUSTS IN EXCESS OF 30MPH OVER
THE LAST HOUR OR TWO...ESPECIALLY NEAR AND SOUTH OF I-70. REPORTS OF
VIRGA DUE TO DRY AIR THROUGH THE BOUNDARY LAYER AND RADAR RETURNS
CURRENTLY SUPPORTING THIS. WITH 35-40KT JET NOTED ALOFT AT
850MB...THERE IS LIKELY SOME MIXING DOWN OF THE STRONGER WINDS AT
4-5KFT GOING ON AND CONTRIBUTING TO THE ENHANCEMENT IN WIND GUSTS.
HAVE THEREFORE BUMPED UP WIND GUSTS FOR THE DURATION OF THE
EVENING...ESPECIALLY NEAR AND SOUTH OF I-70. WINDS SHOULD DROP OFF
BY LATE EVENING AS LOW LEVEL JET SHIFTS EAST WITH SURFACE BOUNDARY.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
THERE IS QUITE A BIT OF DISAGREEMENT AMONG THE MODELS ON THE TRACK
OF THE SURFACE LOW THURSDAY INTO FRIDAY AND THIS WILL HAVE A BIG
IMPACT ON THE WEATHER THAT ENSUES. THE ECMWF TAKES THE LOW SOUTH OF
THE AREA WITH AGREEMENT FROM THE UKMET AND ECMWF ENSEMBLES...WHILE
THE GFS/NAM/ AND SREFS TAKE THE TRACK THROUGH ACROSS THE NORTHERN
PART OR JUST NORTH OF THE AREA. THE GEM SEEMED TO BE A SOLUTION IN
BETWEEN THOSE TWO CAMPS AND THUS TRENDED TOWARD IT.
A WARM FRONT SHOULD BE FORMING ACROSS OR JUST SOUTH OF THE AREA
THURSDAY MORNING AND THIS SHOULD PROVIDE FORCING FOR OVERRUNNING
RAIN SHOWERS WITH THE BEST CHANCES IN THE NORTHERN COUNTIES. AS THE
LOW PRESSURE MOVES ACROSS OR BY THE AREA THROUGH THE DAY IT COULD
DRAG A COLD FRONT THROUGH BY AROUND 0Z...AND WITH A 40 KT LOW LEVEL
JET FORMING UP SOUTH OF THE AREA IN THE AFTERNOON AND SOME ELEVATED
INSTABILITY AVAILABLE COULD SEE SOME THUNDERSTORMS FORM IN THE
AFTERNOON ESPECIALLY IN THE SOUTHERN COUNTIES. WHILE SPC GENERAL
THUNDER OUTLOOK ENCOMPASSES THE ENTIRE FORECAST AREA...THINK THAT
THE BEST CHANCES WILL REMAIN IN THE SOUTHERN COUNTIES WITH ONLY
ISOLATED THUNDER CENTRAL AND PROBABLY NO THUNDER IN THE NORTH. WHILE
AN ISOLATED SEVERE STORM IN THE SOUTH CANNOT BE RULED OUT...BEST
CHANCES FOR SEVERE SHOULD REMAIN SOUTH OF THE AREA.
BY THURSDAY NIGHT THE SYSTEM SHOULD BE MOVING OUT OF THE
AREA...ALTHOUGH SOME UPPER FORCING WILL REMAIN WEST OF THE AREA.
COLD AIR IS LAGGING BEHIND THE FRONT AND THUS WILL KEEP CHANCES FOR
RAIN ACROSS ALL BUT THE NORTHWEST WHERE SNOW COULD MIX IN BEFORE
6Z...AND EXPAND THE MIX ACROSS THE AREA FROM 6-12Z. COULD SEE SOME
STRONG WINDS IN THE WAKE OF THE LOW ON THURSDAY NIGHT AND FRIDAY
DEPENDING ON THE EXACT TRACK. FOR FRIDAY KEPT A CHANCE FOR RAIN OR
SNOW GOING FOR MOST OF THE AREA WITH RAIN CHANCE IN THE FAR SOUTH
BASED ON THE LITTLE FORCING LEFT FROM THE UPPER TROUGH...BUT NOT
ENOUGH TO GO BEYOND A SMALL CHANCE. THE SYSTEM WILL MOVE OUT ON
FRIDAY NIGHT LEAVING A CHANCE FOR SNOW IN THE NORTHEAST AS IT
EXITS...AND BY SATURDAY THE AREA SHOULD BE DRY.
FOR TEMPERATURES GENERALLY USED A CONSENSUS WITH A NUDGE TOWARD THE
GEM.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
GUIDANCE IS IN GENERAL AGREEMENT ON TWO SYSTEMS OF NOTE IN THE
LONG TERM PERIOD...THE FIRST ONE BEING A WEAKENING LOW PUSHING
THROUGH THE GREAT LAKES LATE IN THE WEEKEND/EARLY IN THE WORK
WEEK...AND THE SECOND BEING A STRONGER MORE SIGNIFICANT SYSTEM
PUSHING THROUGH INDIANA/THE LOWER GREAT LAKES REGION TOWARD
MIDWEEK.
GIVEN THIS AGREEMENT...WILL DEVIATE LITTLE FROM ALLBLEND...WHICH
HAS SLIGHT CHANCE POPS FOR THE TRAILING FRONTAL BOUNDARY OF THE
INITIAL SYSTEM...AND STRONGER CHANCE POPS WTIH THE SECOND. THIS
APPEARS REASONABLE. MOST ALL PRECIPITATION IN THE LONG TERM
APPEARS LIKELY TO BE RAIN.
GIVEN UPPER LEVEL FLOW THAT IS ZONAL TO WEAKLY ANTICYCLONIC IN
BETWEEN SYSTEMS...MODERATE TO SOMEWHAT WARMER THAN NORMAL
TEMPERATURES ALSO APPEAR REASONABLE...AND NO DEVIATIONS WERE
NECESSARY.
&&
.AVIATION /DISCUSSION FOR THE 23/09Z IND TAF UPDATE/...
NO CHANGES NECESSARY. PREVIOUS DISCUSSION FOLLOWS.
VFR EXPECTED THRU FCST PERIOD FOR KHUF AND KBMG. MVFR AT KIND AND
KLAF AFTER 231900Z. SHRA AT SITES AFTER 231300Z. STRONG GUSTY WEST
WIND AFTER 240200Z.
MODELS BEGINNING TO COME TOGETHER SOMEWHAT IN DEVELOPING STORM
SYSTEM OVER CENTRAL PLAIN STATES EARLY THURSDAY AND SWEEPING IT
ACROSS CENTRAL INDIANA THURSDAY EVENING. SHOWER BAND WILL DEVELOP
AHEAD OF SYSTEM LIFTING NE ACROSS ROUTES BY 231300Z. COUPLE MODELS
DESTABILIZE AIR ACROSS SOUTHERN INDIANA BY 232100Z HINTING AT
THUNDERSTORM POTENTIAL...PERHAPS KIND...BETTER AT KBMG...BUT THUNDER
THREAT WOULD ONLY LAST THRU 240000Z.
MORE SIGNIFICANT ISSUE MAY BE STRONG AND GUSTY WEST WIND AFTER
240200Z AS DEEEPENING LOW LIFTS NE INTO NE OHIO BY FRIDAY MORNING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...RYAN
SHORT TERM...CP
LONG TERM....NIELD
AVIATION...TUCEK/NIELD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
255 AM EST THU FEB 23 2012
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A CHAOTIC WEATHER PATTERN FOR THE NEXT FEW DAYS WILL LEAD TO CHANCES
FOR RAIN...THUNDERSTORMS...AND SNOW OVER THE NEXT COUPLE OF DAYS.
QUIET WEATHER FOR THE WEEKEND WILL GIVE WAY TO LOW CHANCES FOR RAIN
OR SNOW EARLY IN THE WORK WEEK.
&&
.NEAR TERM /TONIGHT/...
EVENING UPDATE #2...THIN CONVECTIVE LINE HAS QUICKLY DEVELOPED
OVER SOUTHWEST INDIANA JUST SOUTH OF THE FORECAST AREA OVER THE
LAST 30-45 MINUTES. THIS APPEARS TO BE ALONG THE WEAK BOUNDARY
PROGRESSING THROUGH THE SOUTHERN PART OF THE FORECAST AREA.
MESOANALYSIS ALSO SHOWING THAT THIS AREA SITS RIGHT ON THE EDGE OF
THE INSTABILITY AXIS EXTENDING SOUTH INTO THE LOWER MISSISSIPPI
VALLEY. ALSO APPEARS TO HAVE SOME UPPER SUPPORT AIDING DEVELOPMENT
AS TROUGH AXIS ALOFT IS OVERHEAD. HRRR HAS A NICE HANDLE ON
CURRENT DEVELOPMENT...EXPANDING IT EAST ALONG THE OHIO RIVER
VALLEY THIS EVENING. HAVE INSERTED LOW CHANCE POPS OVER FAR
SOUTHERN COUNTIES TO ACCOUNT FOR NORTHERN PART OF THE LINE
CLIPPING SOUTHERN PORTIONS OF THE FORECAST AREA THROUGH THE
EVENING. ANY PRECIP SHOULD BE EAST OF THE FORECAST AREA BY
MIDNIGHT AS WEAK RIDGING BUILDS IN.
PREVIOUS DISCUSSION FOLLOWS.
QUICK UPDATE TO ADDRESS THE GUSTY WINDS PERSISTING ALONG AND AHEAD
OF A WEAK BOUNDARY. HAVE SEEN MAX WIND GUSTS IN EXCESS OF 30MPH OVER
THE LAST HOUR OR TWO...ESPECIALLY NEAR AND SOUTH OF I-70. REPORTS OF
VIRGA DUE TO DRY AIR THROUGH THE BOUNDARY LAYER AND RADAR RETURNS
CURRENTLY SUPPORTING THIS. WITH 35-40KT JET NOTED ALOFT AT
850MB...THERE IS LIKELY SOME MIXING DOWN OF THE STRONGER WINDS AT
4-5KFT GOING ON AND CONTRIBUTING TO THE ENHANCEMENT IN WIND GUSTS.
HAVE THEREFORE BUMPED UP WIND GUSTS FOR THE DURATION OF THE
EVENING...ESPECIALLY NEAR AND SOUTH OF I-70. WINDS SHOULD DROP OFF
BY LATE EVENING AS LOW LEVEL JET SHIFTS EAST WITH SURFACE BOUNDARY.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
THERE IS QUITE A BIT OF DISAGREEMENT AMONG THE MODELS ON THE TRACK
OF THE SURFACE LOW THURSDAY INTO FRIDAY AND THIS WILL HAVE A BIG
IMPACT ON THE WEATHER THAT ENSUES. THE ECMWF TAKES THE LOW SOUTH OF
THE AREA WITH AGREEMENT FROM THE UKMET AND ECMWF ENSEMBLES...WHILE
THE GFS/NAM/ AND SREFS TAKE THE TRACK THROUGH ACROSS THE NORTHERN
PART OR JUST NORTH OF THE AREA. THE GEM SEEMED TO BE A SOLUTION IN
BETWEEN THOSE TWO CAMPS AND THUS TRENDED TOWARD IT.
A WARM FRONT SHOULD BE FORMING ACROSS OR JUST SOUTH OF THE AREA
THURSDAY MORNING AND THIS SHOULD PROVIDE FORCING FOR OVERRUNNING
RAIN SHOWERS WITH THE BEST CHANCES IN THE NORTHERN COUNTIES. AS THE
LOW PRESSURE MOVES ACROSS OR BY THE AREA THROUGH THE DAY IT COULD
DRAG A COLD FRONT THROUGH BY AROUND 0Z...AND WITH A 40 KT LOW LEVEL
JET FORMING UP SOUTH OF THE AREA IN THE AFTERNOON AND SOME ELEVATED
INSTABILITY AVAILABLE COULD SEE SOME THUNDERSTORMS FORM IN THE
AFTERNOON ESPECIALLY IN THE SOUTHERN COUNTIES. WHILE SPC GENERAL
THUNDER OUTLOOK ENCOMPASSES THE ENTIRE FORECAST AREA...THINK THAT
THE BEST CHANCES WILL REMAIN IN THE SOUTHERN COUNTIES WITH ONLY
ISOLATED THUNDER CENTRAL AND PROBABLY NO THUNDER IN THE NORTH. WHILE
AN ISOLATED SEVERE STORM IN THE SOUTH CANNOT BE RULED OUT...BEST
CHANCES FOR SEVERE SHOULD REMAIN SOUTH OF THE AREA.
BY THURSDAY NIGHT THE SYSTEM SHOULD BE MOVING OUT OF THE
AREA...ALTHOUGH SOME UPPER FORCING WILL REMAIN WEST OF THE AREA.
COLD AIR IS LAGGING BEHIND THE FRONT AND THUS WILL KEEP CHANCES FOR
RAIN ACROSS ALL BUT THE NORTHWEST WHERE SNOW COULD MIX IN BEFORE
6Z...AND EXPAND THE MIX ACROSS THE AREA FROM 6-12Z. COULD SEE SOME
STRONG WINDS IN THE WAKE OF THE LOW ON THURSDAY NIGHT AND FRIDAY
DEPENDING ON THE EXACT TRACK. FOR FRIDAY KEPT A CHANCE FOR RAIN OR
SNOW GOING FOR MOST OF THE AREA WITH RAIN CHANCE IN THE FAR SOUTH
BASED ON THE LITTLE FORCING LEFT FROM THE UPPER TROUGH...BUT NOT
ENOUGH TO GO BEYOND A SMALL CHANCE. THE SYSTEM WILL MOVE OUT ON
FRIDAY NIGHT LEAVING A CHANCE FOR SNOW IN THE NORTHEAST AS IT
EXITS...AND BY SATURDAY THE AREA SHOULD BE DRY.
FOR TEMPERATURES GENERALLY USED A CONSENSUS WITH A NUDGE TOWARD THE
GEM.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
GUIDANCE IS IN GENERAL AGREEMENT ON TWO SYSTEMS OF NOTE IN THE
LONG TERM PERIOD...THE FIRST ONE BEING A WEAKENING LOW PUSHING
THROUGH THE GREAT LAKES LATE IN THE WEEKEND/EARLY IN THE WORK
WEEK...AND THE SECOND BEING A STRONGER MORE SIGNIFICANT SYSTEM
PUSHING THROUGH INDIANA/THE LOWER GREAT LAKES REGION TOWARD
MIDWEEK.
GIVEN THIS AGREEMENT...WILL DEVIATE LITTLE FROM ALLBLEND...WHICH
HAS SLIGHT CHANCE POPS FOR THE TRAILING FRONTAL BOUNDARY OF THE
INITIAL SYSTEM...AND STRONGER CHANCE POPS WTIH THE SECOND. THIS
APPEARS REASONABLE. MOST ALL PRECIPITATION IN THE LONG TERM
APPEARS LIKELY TO BE RAIN.
GIVEN UPPER LEVEL FLOW THAT IS ZONAL TO WEAKLY ANTICYCLONIC IN
BETWEEN SYSTEMS...MODERATE TO SOMEWHAT WARMER THAN NORMAL
TEMPERATURES ALSO APPEAR REASONABLE...AND NO DEVIATIONS WERE
NECESSARY.
&&
.AVIATION /DISCUSSION FOR THE 23/06Z TAFS/...
VFR EXPECTED THRU FCST PERIOD FOR KHUF AND KBMG. MVFR AT KIND AND
KLAF AFTER 231900Z. SHRA AT SITES AFTER 231300Z. STRONG GUSTY WEST
WIND AFTER 240200Z.
MODELS BEGINNING TO COME TOGETHER SOMEWHAT IN DEVELOPING STORM
SYSTEM OVER CENTRAL PLAIN STATES EARLY THURSDAY AND SWEEPING IT
ACROSS CENTRAL INDIANA THURSDAY EVENING. SHOWER BAND WILL DEVELOP
AHEAD OF SYSTEM LIFTING NE ACROSS ROUTES BY 231300Z. COUPLE MODELS
DESTABILIZE AIR ACROSS SOUTHERN INDIANA BY 232100Z HINTING AT
THUNDERSTORM POTENTIAL...PERHAPS KIND...BETTER AT KBMG...BUT THUNDER
THREAT WOULD ONLY LAST THRU 240000Z.
MORE SIGNIFICANT ISSUE MAY BE STRONG AND GUSTY WEST WIND AFTER
240200Z AS DEEEPENING LOW LIFTS NE INTO NE OHIO BY FRIDAY MORNING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...RYAN
SHORT TERM...CP
LONG TERM....NIELD
AVIATION...TUCEK
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1209 AM EST THU FEB 23 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A CHAOTIC WEATHER PATTERN FOR THE NEXT FEW DAYS WILL LEAD TO CHANCES
FOR RAIN...THUNDERSTORMS...AND SNOW OVER THE NEXT COUPLE OF DAYS.
QUIET WEATHER FOR THE WEEKEND WILL GIVE WAY TO LOW CHANCES FOR RAIN
OR SNOW EARLY IN THE WORK WEEK.
&&
.NEAR TERM /TONIGHT/...
EVENING UPDATE #2...THIN CONVECTIVE LINE HAS QUICKLY DEVELOPED
OVER SOUTHWEST INDIANA JUST SOUTH OF THE FORECAST AREA OVER THE
LAST 30-45 MINUTES. THIS APPEARS TO BE ALONG THE WEAK BOUNDARY
PROGRESSING THROUGH THE SOUTHERN PART OF THE FORECAST AREA.
MESOANALYSIS ALSO SHOWING THAT THIS AREA SITS RIGHT ON THE EDGE OF
THE INSTABILITY AXIS EXTENDING SOUTH INTO THE LOWER MISSISSIPPI
VALLEY. ALSO APPEARS TO HAVE SOME UPPER SUPPORT AIDING DEVELOPMENT
AS TROUGH AXIS ALOFT IS OVERHEAD. HRRR HAS A NICE HANDLE ON
CURRENT DEVELOPMENT...EXPANDING IT EAST ALONG THE OHIO RIVER
VALLEY THIS EVENING. HAVE INSERTED LOW CHANCE POPS OVER FAR
SOUTHERN COUNTIES TO ACCOUNT FOR NORTHERN PART OF THE LINE
CLIPPING SOUTHERN PORTIONS OF THE FORECAST AREA THROUGH THE
EVENING. ANY PRECIP SHOULD BE EAST OF THE FORECAST AREA BY
MIDNIGHT AS WEAK RIDGING BUILDS IN.
PREVIOUS DISCUSSION FOLLOWS.
QUICK UPDATE TO ADDRESS THE GUSTY WINDS PERSISTING ALONG AND AHEAD
OF A WEAK BOUNDARY. HAVE SEEN MAX WIND GUSTS IN EXCESS OF 30MPH OVER
THE LAST HOUR OR TWO...ESPECIALLY NEAR AND SOUTH OF I-70. REPORTS OF
VIRGA DUE TO DRY AIR THROUGH THE BOUNDARY LAYER AND RADAR RETURNS
CURRENTLY SUPPORTING THIS. WITH 35-40KT JET NOTED ALOFT AT
850MB...THERE IS LIKELY SOME MIXING DOWN OF THE STRONGER WINDS AT
4-5KFT GOING ON AND CONTRIBUTING TO THE ENHANCEMENT IN WIND GUSTS.
HAVE THEREFORE BUMPED UP WIND GUSTS FOR THE DURATION OF THE
EVENING...ESPECIALLY NEAR AND SOUTH OF I-70. WINDS SHOULD DROP OFF
BY LATE EVENING AS LOW LEVEL JET SHIFTS EAST WITH SURFACE BOUNDARY.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
THERE IS QUITE A BIT OF DISAGREEMENT AMONG THE MODELS ON THE TRACK
OF THE SURFACE LOW THURSDAY INTO FRIDAY AND THIS WILL HAVE A BIG
IMPACT ON THE WEATHER THAT ENSUES. THE ECMWF TAKES THE LOW SOUTH OF
THE AREA WITH AGREEMENT FROM THE UKMET AND ECMWF ENSEMBLES...WHILE
THE GFS/NAM/ AND SREFS TAKE THE TRACK THROUGH ACROSS THE NORTHERN
PART OR JUST NORTH OF THE AREA. THE GEM SEEMED TO BE A SOLUTION IN
BETWEEN THOSE TWO CAMPS AND THUS TRENDED TOWARD IT.
A WARM FRONT SHOULD BE FORMING ACROSS OR JUST SOUTH OF THE AREA
THURSDAY MORNING AND THIS SHOULD PROVIDE FORCING FOR OVERRUNNING
RAIN SHOWERS WITH THE BEST CHANCES IN THE NORTHERN COUNTIES. AS THE
LOW PRESSURE MOVES ACROSS OR BY THE AREA THROUGH THE DAY IT COULD
DRAG A COLD FRONT THROUGH BY AROUND 0Z...AND WITH A 40 KT LOW LEVEL
JET FORMING UP SOUTH OF THE AREA IN THE AFTERNOON AND SOME ELEVATED
INSTABILITY AVAILABLE COULD SEE SOME THUNDERSTORMS FORM IN THE
AFTERNOON ESPECIALLY IN THE SOUTHERN COUNTIES. WHILE SPC GENERAL
THUNDER OUTLOOK ENCOMPASSES THE ENTIRE FORECAST AREA...THINK THAT
THE BEST CHANCES WILL REMAIN IN THE SOUTHERN COUNTIES WITH ONLY
ISOLATED THUNDER CENTRAL AND PROBABLY NO THUNDER IN THE NORTH. WHILE
AN ISOLATED SEVERE STORM IN THE SOUTH CANNOT BE RULED OUT...BEST
CHANCES FOR SEVERE SHOULD REMAIN SOUTH OF THE AREA.
BY THURSDAY NIGHT THE SYSTEM SHOULD BE MOVING OUT OF THE
AREA...ALTHOUGH SOME UPPER FORCING WILL REMAIN WEST OF THE AREA.
COLD AIR IS LAGGING BEHIND THE FRONT AND THUS WILL KEEP CHANCES FOR
RAIN ACROSS ALL BUT THE NORTHWEST WHERE SNOW COULD MIX IN BEFORE
6Z...AND EXPAND THE MIX ACROSS THE AREA FROM 6-12Z. COULD SEE SOME
STRONG WINDS IN THE WAKE OF THE LOW ON THURSDAY NIGHT AND FRIDAY
DEPENDING ON THE EXACT TRACK. FOR FRIDAY KEPT A CHANCE FOR RAIN OR
SNOW GOING FOR MOST OF THE AREA WITH RAIN CHANCE IN THE FAR SOUTH
BASED ON THE LITTLE FORCING LEFT FROM THE UPPER TROUGH...BUT NOT
ENOUGH TO GO BEYOND A SMALL CHANCE. THE SYSTEM WILL MOVE OUT ON
FRIDAY NIGHT LEAVING A CHANCE FOR SNOW IN THE NORTHEAST AS IT
EXITS...AND BY SATURDAY THE AREA SHOULD BE DRY.
FOR TEMPERATURES GENERALLY USED A CONSENSUS WITH A NUDGE TOWARD THE
GEM.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AN UPPER TROUGH MOVING ACROSS THE NORTHERN U.S. WILL AFFECT OUR
WEATHER AROUND MONDAY. HOWEVER MODELS HAVE TRENDED WITH LESS PRECIP
WITH THIS SYSTEM. I AM NOT CONFIDENT ENOUGH TO TAKE OUT CHANCE OF
PRECIP MONDAY...BUT WILL DROP MENTION ACROSS OUR SOUTHEAST HALF
SUNDAY NIGHT AND ALL AREAS MONDAY MONDAY NIGHT.
A SECOND AND POTENTIALLY MUCH STRONGER SYSTEM WILL AFFECT OUR
WEATHER BY THE MIDDLE OF NEXT WEEK. BOTH 12Z EURO AND 12Z GFS BRINGS
SIGNIFICANT PRECIP BY DAY 7. THERE IS A LOT OF DISAGREEMENT IN THE
SURFACE LOW TRACK AND ULTIMATELY PRECIP TYPE. AT THIS TIME MY
CONFIDENCE IS LOW...SO FOR NOW WILL RAISE ALL BLEND TEMPS TUESDAY
NIGHT AND LOWER THEM WEDNESDAY TO REDUCE THE DIURNAL RANGE. THIS
WOULD GIVE ME SNOW TUESDAY NIGHT WITH MIXED PRECIP SOUTH AND MOSTLY
RAIN WEDNESDAY. CONFIDENCE IS LOW ON PRECIP TYPE...BUT THIS MIDDLE
OF THE ROAD APPROACH SEEMS BEST WAY TO GO UNTIL MODELS HAVE A BETTER
AGREEMENT.
&&
.AVIATION /DISCUSSION FOR THE 23/06Z TAFS/...
VFR EXPECTED THRU FCST PERIOD FOR KHUF AND KBMG. MVFR AT KIND AND
KLAF AFTER 231900Z. SHRA AT SITES AFTER 231300Z. STRONG GUSTY WEST
WIND AFTER 240200Z.
MODELS BEGINNING TO COME TOGETHER SOMEWHAT IN DEVELOPING STORM
SYSTEM OVER CENTRAL PLAIN STATES EARLY THURSDAY AND SWEEPING IT
ACROSS CENTRAL INDIANA THURSDAY EVENING. SHOWER BAND WILL DEVELOP
AHEAD OF SYSTEM LIFTING NE ACROSS ROUTES BY 231300Z. COUPLE MODELS
DESTABILIZE AIR ACROSS SOUTHERN INDIANA BY 232100Z HINTING AT
THUNDERSTORM POTENTIAL...PERHAPS KIND...BETTER AT KBMG...BUT THUNDER
THREAT WOULD ONLY LAST THRU 240000Z.
MORE SIGNIFICANT ISSUE MAY BE STRONG AND GUSTY WEST WIND AFTER
240200Z AS DEEEPENING LOW LIFTS NE INTO NE OHIO BY FRIDAY MORNING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...RYAN
SHORT TERM...CP
LONG TERM....JH
AVIATION...TUCEK
AREA FORECAST DISCUSSION
NWS TOPEKA KS
347 AM CST THU FEB 23 2012
.DISCUSSION...
FAST UPPER FLOW CONTINUES TODAY...AND GIVING THE FORECAST MANY
CHALLENGES. DEVELOPING UPPER WAVE IN THE NORTHERN PLAINS WITH
100-150M 500MB HEIGHT FALLS IN THE PACIFIC NORTHWEST WAS MAKING
QUICK SOUTHEAST PROGRESS INTO THE PLAINS EARLY THIS MORNING.
INCREASING MID LEVEL FRONTOGENESIS IN THE CENTRAL PLAINS AND STRONG
ISENTROPIC LIFT AROUND 300K HAS BEEN SUFFICIENT TO OVERCOME DRY
LOWER LEVELS AND BRING VERY LIGHT PRECIP TO NORTHERN KANSAS SINCE
LATE EVENING...BUT RADAR TRENDS SEEM TO BE GOING ALONG WITH MODELS
IN LIFT DIMINISHING TOWARD SUNRISE. SURFACE PATTERN RATHER JUMBLED
AT 08Z WITH SURFACE LOWS IN SOUTHWEST KANSAS...SOUTH CENTRAL
NEBRASKA...AND SOUTHERN SOUTH DAKOTA. WHERE MIXING AND CLOUDS HAVE
PERSISTED...TEMPS REMAIN RATHER MILD...WITH NORTHWEST WINDS BEHIND
THE LOWS ALLOWING MUCH COOLER READINGS TO OCCUR. A FEW 30-40KT
SUSTAINED SPEED OBSERVATIONS WERE NOTED IN WESTERN SOUTH DAKOTA.
UPPER TROF TO CONTINUE TO DEEPEN AS IT ZIPS SOUTHEAST TODAY...WITH
DEEP AND STRONG COLD AIR ADVECTION AND MIXING BEHIND SURFACE LOW
PRESSURE TRACKING EAST THROUGH KANSAS. SOME DIFFERENCES IN SPECIFIC
TIMING AND STRENGTH OF WINDS BEHIND IT...BUT ADVISORY LEVELS SHOULD
BE EASY TO ATTAIN GIVEN GOOD DOWNWARD MOTION AND 925MB WINDS IN THE
30-50KT RANGE. CANNOT RULE OUT A FEW LOCATIONS REACHING WARNING
LEVELS BRIEFLY...BUT DO NOT THINK IT WILL BE LONG-LIVED OR
WIDESPREAD. STRONG MIXING SHOULD PERSIST INTO THE EVENING
HOURS...KEEPING WINDS ON THE HIGH SIDE IN AT LEAST EASTERN AREAS
AFTER DARK. ADVISORY BREAKDOWN IS BASED ON EXPECTED NNW-SSE ONSET OF
WINDS EARLY TODAY AND BETTER GRADIENT INTO THE EVENING IN THE EAST.
TEMPERATURE TRENDS ALSO TRICKY WITH THE AFOREMENTIONED
CONSIDERATIONS ON HOW THINGS WILL START NEAR DAWN WHILE MIXING WILL
INCREASE QUICKLY BUT INTO 850MB TEMPS DROPPING 6-10C IN THE MORNING.
HAVE INCREASED THE RANGES ACROSS THE AREA BUT CONFIDENCE IS LOW ON
SPECIFIC HOURLY VALUES. MUCH OF THE AREA TO BE ON THE SUBSIDENCE
SIDE OF THE SYSTEM...BUT PRECIP MAY SWING SOUTH THROUGH EASTERN
NEBRASKA AS THE UPPER TROF ENTERS IOWA AND THREATEN NORTHERN AREAS
BY LATE THIS AFTERNOON. WILL INCLUDE SMALL PROBABILITIES FOR THIS
OCCURRENCE INTO THE EVENING. ANY AMOUNTS SHOULD BE LIGHT AND MOSTLY
RAIN...THOUGH IF IT CAN HANG ON INTO THE EVENING...SNOW COULD RESULT
IN LIMITED VISIBILITIES IN THE STILL GUSTY WINDS.
DEEP MIXING AGAIN EXPECTED ON FRIDAY...THOUGH ADVISORY LEVELS NOT
NEARLY AS LIKELY...AND STILL APPEARS BIGGEST ADVISORY ISSUE WOULD BE
WINDS IN THE STEEP LAPSE RATES TO AROUND 600MB. THE MIXING SHOULD
GIVE RISE TO SOME MID CLOUD..AND CANNOT RULE OUT SOME HIGH-BASED
SHOWERS RESULTING IN TRACE PRECIP IN THE AFTERNOON. WILL LET LATER
SHIFTS DETERMINE DETAILS ON THIS.
FRIDAY NIGHT TO BE ON THE TRANQUIL SIDE FOR THIS FORECAST WITH
LITTLE CLOUD AND WEAK WINDS BEYOND 02Z...BUT THE WIND MACHINE STARTS
UP AGAIN BY LATE SATURDAY WITH THE NEXT UPPER TROF APPROACHING FROM
THE WEST. A 20MB PRESSURE GRADIENT IS PROGGED BY LATE DAY...WITH
925MB WINDS NEAR 60KT FOR SATURDAY NIGHT. LOW LEVEL RIDGING BEHIND
THE CURRENT SYSTEM SHOULD KEEP MOISTURE IN CHECK FOR DRY CONDITIONS
DESPITE WARM AIR ADVECTION.
PRECIP CHANCES CONTINUE TO WANE ON INTO SUNDAY NIGHT WITH GFS AND
ECMWF VERY SIMILAR WITH A LACK OF ENERGY CUTTING OFF BEHIND THE TROF
AS EARLIER RUNS ADVERTISED. TIMING DIFFERENCES CONTINUE FOR THE NEXT
SYSTEM AND CHANGES TO THE FORECAST FOR THE MID WEEK WERE SMALL AT
THIS RANGE. SIMILAR RHS LIKELY FOR FRIDAY AS WELL WITH ELEVATED FIRE
WEATHER RESULTING WITH BREEZY NORTHWEST WINDS.
65
&&
.FIRE WEATHER...
ANOTHER DAY OF VERY HIGH TO NEAR EXTREME CONDITIONS FORECAST WITH
VERY HIGH WINDS THE MAIN PLAYER. CONFIDENCE ON TEMPERATURE AND
DEWPOINT VALUES GIVE RISE TO MUCH UNCERTAINTY IN HUMIDITIES. ERRING
ON THE DRY SIDE STILL KEEPS RHS IN THE 30-PLUS RANGE. WITH WET
GROUND FROM RECENT RAINS ALSO IN PLAY...WILL HOLD OFF ON ANY WATCHES
OR WARNINGS AT THIS POINT.
65
&&
.AVIATION...
RADAR WOULD SUGGEST THAT THERE IS A NARROW BAND OF FRONTOGENESIS
ALONG WITH SOME QG FORCING THAT HAS ALLOWED THE LIGHT RAIN TO
DEVELOP OVER THE AREA. RUC AND NAM PROGS SUGGEST THAT THIS WILL
STICK AROUND A FEW MORE HOURS...THOUGHT CONDITIONS SHOULD REMAIN VFR
THROUGH THE DAY. THERE IS SOME INDICATION OF WRAP AROUND LOW LEVEL
MOISTURE MOVING IN AROUND 00Z FRI. THINK THIS SHOULD REMAIN ABOVE 3
KFT. MODELS ARE COMING IN WITH A STRONGER PRESSURE GRADIENT.
THEREFORE HAVE INCREASED WINDS AND GUSTS FOR THE DAY THURSDAY.
WOLTERS
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM NOON TODAY TO 9 PM CST THIS EVENING FOR
KSZ011-012-024-026-038>040-054>056-058-059.
WIND ADVISORY FROM 9 AM THIS MORNING TO 6 PM CST THIS EVENING
FOR KSZ008>010-020>023-034>037.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1114 PM CST WED FEB 22 2012
...AVIATION UPDATE...
.DISCUSSION...
SEE PREV DISCUSSION.
&&
.AVIATION...
RADAR WOULD SUGGEST THAT THERE IS A NARROW BAND OF FRONTOGENESIS
ALONG WITH SOME QG FORCING THAT HAS ALLOWED THE LIGHT RAIN TO
DEVELOP OVER THE AREA. RUC AND NAM PROGS SUGGEST THAT THIS WILL
STICK AROUND A FEW MORE HOURS...THOUGHT CONDITIONS SHOULD REMAIN VFR
THROUGH THE DAY. THERE IS SOME INDICATION OF WRAP AROUND LOW LEVEL
MOISTURE MOVING IN AROUND 00Z FRI. THINK THIS SHOULD REMAIN ABOVE 3
KFT. MODELS ARE COMING IN WITH A STRONGER PRESSURE GRADIENT.
THEREFORE HAVE INCREASED WINDS AND GUSTS FOR THE DAY THURSDAY.
WOLTERS
&&
.PREV DISCUSSION... /316 PM CST WED FEB 22 2012/
THROUGH THURSDAY...A WARM AFTERNOON WAS UNDERWAY ON WEDNESDAY WITH
HIGHS EXPECTED TO TOP OUT IN THE UPPER 50S TO MIDDLE 60S ACROSS THE
AREA UNDER FAST WEST NORTHWESTERLY FLOW ALOFT AND A WESTERLY BREEZE
AT THE SURFACE. THERE WERE SOME MID AND HIGH CLOUDS IN THE
AREA...WITH MORE AMPLE CLOUD COVER OVER WESTERN NEBRASKA IN ADVANCE
OF AN INCOMING SHORT WAVE TROUGH. IT APPEARS THAT SOME LIGHT PRECIP
MAY SPREAD DOWNSTREAM OUT OF WESTERN NEBRASKA THIS EVENING AS THE
TROUGH ENTERS THE PLAINS...BUT WITH FAIRLY DRY AIR IN THE LOW TO MID
LEVELS IT SHOULD BE DIFFICULT FOR ANYTHING MORE THAN PERHAPS A FEW
SPRINKLES TO FALL ACROSS THE LOCAL FORECAST AREA. TEMPERATURES WILL
STAY QUITE WARM THROUGH THE EVENING AND EARLY MORNING HOURS AS A
BREEZE WILL KEEP THE BOUNDARY LAYER MIXED AND HIGH CLOUDS SHOULD
INSULATE A BIT. HOWEVER...AS THE TROUGH CROSSES THE PLAINS...A
STRONG COLD FRONT WILL MOVE INTO THE AREA AFTER MIDNIGHT AND CROSS
THE ENTIRE FORECAST AREA BY SUNRISE. TEMPERATURES BEHIND THE FRONT
WILL DROP OFF...SO WHILE MOST OF THE NIGHT WILL BE WARM...TEMPS WILL
DROP QUICKLY AS THE FRONT PASSES.
THE POST FRONTAL AIRMASS ON THURSDAY WILL BE A WINDY ONE. EXPECT
DEEP MIXING TO AT LEAST 800 HPA...AND PERHAPS HIGHER BY LATE
AFTERNOON. THIS WILL ALLOW STRONG WINDS TO MIX TO THE SURFACE...
SUPPORTED BY PERIODS OF STRONG DOWNWARD MOTION THROUGH A
UNIDIRECTIONAL WIND FIELD IN THE WAKE OF THE UPPER TROUGH. HAVE
ISSUED A WIND ADVISORY FOR NORTHWESTERN PARTS OF THE FORECAST AREA
WHERE CONFIDENCE IS HIGHEST IN SUSTAINED WINDS GREATER THAN 30 MPH.
THERE IS A BIT OF UNCERTAINTY REGARDING HOW WINDY IT WILL GET ACROSS
THE REMAINDER OF THE AREA...BUT THE POTENTIAL AT LEAST EXISTS FOR
THE ADVISORY TO BE EXPANDED WITH GUST POTENTIAL IN THE 45 TO 50 MPH
RANGE IF FULL MIXING POTENTIAL IS REACHED. THE WAVE IS STRONG...BUT
EXPECT LITTLE MORE THAN A FEW SPRINKLES ON FRIDAY OWING TO DRY AIR.
TEMPS WILL WARM INTO THE UPPER 40S AND LOWER 50S AS THE WARM START
TO THE MORNING AND DEEP MIXING MITIGATES A BIT OF THE COLD
ADVECTION. THE DEEP MIXING AND DRY ADVECTION PRESENTS A DIFFICULT
FIRE WEATHER FORECAST AS WELL. AT THE CURRENT TIME EXPECT MIN RH
VALUES TO APPROACH 30 PERCENT...BUT THAT MAY BE CONSERVATIVE
DEPENDING ON JUST HOW DEEP THE BOUNDARY LAYER MIXES...AND IS ALSO
HIGHLY DEPENDENT ON HIGH TEMPS.
BARJENBRUCH
THURSDAY NIGHT AND FRIDAY...UPPER TROUGH AND ASSOCIATED SURFACE
LOW TRACKS INTO THE MID MISSISSIPPI VALLEY THURSDAY NIGHT. ALL
MODELS HAVE SOME SORT OF WRAPAROUND LIGHT SNOW TO THE NORTH AND
NORTHWEST OF SURFACE LOW AND THIS COULD BRUSH EXTREME NORTHEAST KS
THURSDAY EVENING. HOWEVER...WITH MAIN DYNAMICS AND ISENTROPIC LIFT
TO THE NORTH OF KS...HAVE LITTLE CONFIDENCE OF ANYTHING REALLY
FALLING OUT OF THE SKY DURING THAT BRIEF WINDOW. NORTHEAST FLOW
CONTINUES TRANSPORTING COOL AIR INTO EASTERN KS ON FRIDAY WITH HIGHS
ONLY IN THE LOWER TO MID 40S.
SURFACE HIGH PRESSURE RIDGE THEN MOVES ACROSS THE PLAINS FRIDAY
NIGHT WITH CLEAR SKIES EXPECTED. AS THE RIDGE TRAVERSES EAST ON
FRIDAY NIGHT AND SATURDAY...LOW PRESSURE DEVELOPS IN THE NORTHERN
AND CENTRAL HIGH PLAINS AS STRONG MID AND UPPER JET IMPINGES ON
THE ROCKIES. SIGNIFICANT PRESSURE GRADIENT SETS UP BETWEEN THESE
WEATHER SYSTEMS AND THIS SHOULD WARM TEMPS UP ON SATURDAY WITH
STRONG SOUTHERLY WINDS. MIXING WILL ALSO KEEP TEMPERATURES
RELATIVELY MILD SATURDAY NIGHT...IN THE MID TO UPPER 30S.
UPPER TROUGH AND INTENSE LOW THEN MOVE INTO THE UPPER MIDWEST
SUNDAY. ALL LONG RANGE MODELS KEEP STRONGEST LIFT WELL TO NORTH OF
EASTERN KS AND HAVE KEPT SUNDAY DRY AS A RESULT. 12Z GEM AND ECMWF
ATTEMPT TO DEVELOP SHOWERS ALONG TRAILING COLD FRONT IN EC KS
SUNDAY EVENING. THEN RIDGE OF HIGH PRESSURE PUSHES INTO THE AREA
FROM THE NORTHWEST FOR LATE SUNDAY NIGHT AND MONDAY.
DETAILS THEN GET FUZZY ON MONDAY NIGHT AND TUESDAY INTO TUESDAY
NIGHT. LAST COUPLE RUNS OF GFS AND ECMWF BRING SYSTEM ACROSS DURING
THAT TIME FRAME...BUT DIFFER IN ONSET TIMING AND LOCATION OF WARM
SECTOR. MORE NORTHERN AND INTENSE 12Z GFS WOULD GIVE CHANCE OF
THUNDERSTORMS AND MUCH HIGHER TEMPERATURES TUESDAY WHEREAS LATEST
ECMWF KEEPS LOW WELL TO SOUTH AND SNOW MORE LIKELY. HAVE GONE WITH
A COMPROMISE AT THIS TIME. WOULD EXPECT MODELS TO BECOME MORE
CONSISTENT WITH EACH OTHER ON THIS SYSTEM WHEN UPPER JET/TROUGH
MAKES IT TO THE COAST THIS WEEKEND AND GETS SAMPLED.
RIGHT NOW THE TIMING OF THAT SYSTEM WOULD KEEP THE DAYTIME HOURS ON
WEDNESDAY DRY...AND HAVE GONE WITH THAT SCENARIO.
PHILLIPS
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
327 AM EST THU FEB 23 2012
.UPDATE...
ISSUED AT 327 AM EST THU FEB 23 2012
WILL BE MAINTAINING THE WATCH FOR ALL COUNTIES FOR LATE THIS
AFTERNOON INTO TONIGHT. MORE DETAILS SHORTLY.
&&
.SYNOPSIS...
ISSUED AT 1045 PM EST WED FEB 22 2012
AFTER MOSTLY LIGHT PRECIPITATION MOVES THROUGH THE AREA OVERNIGHT...
HIGH
PRESSURE WILL BRING CLEARING CONDITIONS TO THE AREA THURSDAY
MORNING. A STORM DEVELOPING IN THE SOUTHERN PLAINS WILL APPROACH
THE AREA DURING THE DAY THURSDAY...BRINGING A PERIOD OF
SIGNIFICANT SNOWFALL TO THE AREA THURSDAY NIGHT. SOME LAKE EFFECT
SNOW IS EXPECTED INTO SATURDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 400 PM EST WED FEB 22 2012
THERE IS THE THREAT FOR A SIGNIFICANT SNOWFALL EVENT THURSDAY
NIGHT INTO FRIDAY. CURRENT THINKING IS 4 TO 7 INCHES OVER THE
CENTRAL CWA... NEAR INTERSTATE 96. MOST OF THE SNOW SHOULD FALL
DURING THE MID TO LATE EVENING HOURS OF THURSDAY NIGHT INTO THE
MID MORNING HOURS OF FRIDAY.
THERE IS ALSO THE THREAT FOR A BRIEF BURST OF SIGNIFICANT SNOW THIS
EVENING AS A SHORTWAVE OVER WISCONSIN HEADS EAST ACROSS LAKE
MICHIGAN AND INTENSIFIES THIS EVENING. BOTH THE HRRR SUGGESTS UP
TO .25 INCHES OF QPF IN 3 HOURS OVER PARTS OF NORTHERN OTTAWA AND
CENTRAL AND NORTHERN KENT COUNTIES BY BETWEEN 9 PM AND MIDNIGHT.
SINCE THE PRECIPITATION AREA ALREADY IS OVER CENTRAL WISCONSIN AND
IS HEADED EAST... IT WOULD SEEM MORE THAN REASONABLE THIS WOULD
IMPACT CENTRAL LOWER MICHIGAN THIS EVENING. THERE IS GOOD LIFT IN
THE DGZ AS THIS FEATURE MOVES THROUGH THE AREA SO THAT SHOULD HELP
THE SNOWFLAKE PRODUCTION. WITH SURFACE DEW POINTS IN THE MID 20S
THE SNOW WILL WET BULB DOWN THE AIR TEMP QUICKLY SO SNOW WILL REACH
THE GROUND.
ONCE THAT FEATURE MOVES EAST OF THE CWA LATER THIS EVENING SHORT
WAVE RIDGING FOLLOWS LATE TONIGHT INTO MIDDAY THURSDAY. THAT
SHOULD ALLOW THE SKIES TO BECOME PARTLY CLOUDY...AT LEAST FOR A
TIME.
THEN WE HAVE THE ISSUE OF OUR STORM ON THURSDAY NIGHT. THE GFS AND
NAM HAVE BEEN CONSISTENTLY FARTHER NORTH THEN THE ECMWF HAS BEEN
WITH THIS SYSTEM. HOWEVER... THE ECMWF HAS FINALLY SHOWED A
SIGNIFICANT SHIFT NORTHWARD IN THE TRACK OF THE SYSTEM THURSDAY
NIGHT. THE REGIONAL GEM IS FARTHER NORTH AND WEST THAN IS THE
HEMISPHERIC GEM... TRACKING THE LOW NEAR DETROIT LATE THURSDAY
NIGHT. THERE IS SIGNIFICANT FGEN SUPPORT OF THIS EVENT AS IT IS
EXIT REGION OF 165 KNOT 300 MB JET CORE THAT TURNS CYCLONIC AS
IT HEADS NORTHEAST TOWARD CENTRAL OHIO FRIDAY MORNING. THIS ALSO
CREATES QUIET THE TROWAL FEATURE WITH STRONG ISOTROPIC LIFT. THERE
IS 3 TO 4 G/KG OF WATER NEAR 700 MB WHILE THIS IS GOING ON SO
SNOWFALL AMOUNTS OF 3 TO 6 INCHES SHOULD BE EASY TO DO WITH THIS
SET UP.
I WOULD HAVE ISSUED A WINTER STORM WATCH FOR THIS EVENT EXPECT FOR
THE ISSUE OF MODEL UNCERTAINTY. I WILL LET THE MIDNIGHT SHIFT
CONSIDER DOING JUST THAT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 400 PM EST WED FEB 22 2012
UNSETTLED/ACTIVE WEATHER IS EXPECTED TO GENERALLY CONTINUE THROUGH
THE LONG TERM PORTION OF THE FORECAST...IF NOT THE NEXT COUPLE OF
WEEKS. MAIN ITEMS OF CONCERN ARE LINGERING SNOW ON FRI...LAKE EFFECT
FRI NIGHT/SAT...SYSTEM COMING IN LATE SUN THROUGH MON...AND LAKE
EFFECT AGAIN ON TUE.
AN ACTIVE JET STREAM IS EXPECTED TO AFFECT MOST OF THE COUNTRY
THROUGH THE NEXT WEEK. WE ARE EXPECTING TO SEE STRONG PIECES OF
ENERGY BE PUSHED ACROSS THE COUNTRY...FUELED BY A VERY STRONG JET
OVER THE NRN PACIFIC. A LOT OF THIS ENERGY IS EXPECTED TO DIVE SE
INTO THE WRN STATES...BEFORE LIFTING E/NE TOWARD THE GREAT LAKES
REGION.
WE WILL SEE THE FIRST IN THE SERIES OF PV ANOMALIES/WAVES BE MOVING
OUT OF THE AREA AFTER DEPOSITING ACCUMULATING SNOW THU NIGHT AND
INTO FRI. IN THE WAKE OF THIS PHASED UPPER FEATURE...A POOL OF
ARCTIC AIR TO OUR NW WILL BE TAPPED AND WILL PUSH INTO THE AREA.
SYNOPTIC SNOW WILL LIKELY BE ONGOING EARLY ON FRI BEFORE TAPERING
OFF DURING THE DAY. THE SNOW WILL TRANSITION TO SOME LAKE EFFECT AS
H850 TEMPS DROP DOWN TO AROUND -10C TO -12C. WE COULD SEE SOME
DECENT LAKE EFFECT ACCUMS FOR MAINLY NW FAVORED AREAS WITH MOISTURE
POTENTIALLY UP THROUGH 10K FT LATE FRI AND FRI NIGHT. INVERSION
HEIGHTS WILL GRADUALLY FALL THROUGH SAT AS THE UPPER FLOW WILL
TRANSITION TO ANTI-CYCLONIC BY SAT EVENING.
WE WILL SEE A BRIEF BREAK IN THE WEATHER THEN SAT NIGHT THROUGH A
GOOD PORTION OF SUN FOR MOST AREAS AS RIDGING BUILDS IN. NW AREAS
COULD SEE SOME LIGHT PCPN SUN AFTERNOON AS WAA/ISENTROPIC ASCENT
STRENGTHENS AHEAD OF THE NEXT SYSTEM. THE UNSETTLED WEATHER WILL
SPREAD ACROSS THE ENTIRE AREA SUN NIGHT AS THE NEXT STRONG WAVE
DIVING INTO THE SW U.S. EARLY IN THE WEEKEND WILL LIFT NE. THIS WILL
LIKELY TAP SOME WARMER AND MOIST AIR FROM THE GULF AND ADVECT IT
INTO THE AREA LATE SUN THROUGH MON MORNING. PCPN COULD START OFF AS
SNOW...BUT SHOULD CHANGE OVER TO RAIN FOR A PERIOD SUN NIGHT AND
EARLY MON. THUNDER CAN NOT EVEN BE RULED OUT WITH THE STRONG FORCING
ASSOCIATED WITH THE SYSTEM. NOT CONFIDENT ENOUGH YET TO ADD THUNDER
INTO THE FCST.
THE COLD FRONT WILL MOVE THROUGH ON MON...AND A FLOOD OF COLDER AIR
WILL MOVE IN ACROSS THE STATE. THIS WILL HELP TO START THE LAKE
EFFECT BACK UP AS H850 TEMPS DROP BACK DOWN TO AROUND -10C TO -12C.
MODELS ARE INDICATING THOUGH THAT THE LOW LEVEL FLOW WILL TEND TO BE
NE WITH THE WAY THE RIDGE BUILDS IN FROM THE NW. THIS WILL TEND TO
LIMIT THE LAKE EFFECT CHCS AND AMOUNTS. QUITE A BIT OF UNCERTAINTY
WITH REGARDS TO TIMING AND TRACK WITH ANOTHER WAVE THAT IS EXPECTED
TO LIFT OUT FROM THE WRN U.S. BY MID WEEK NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1156 PM EST WED FEB 22 2012
BRIEFLY SAW IFR VISIBILITY AT KGRR WITH LARGE SNOWFLAKES FALLING.
THE ASSOCIATED AREA OF HEAVIER PRECIPITATION MOVING EAST TOWARDS
KLAN SHOULD BE PREDOMINANTLY SNOW AND BRING...BRIEF IFR VSBYS
THERE TOO. ELSEWHERE...DO NOT EXPECT SUCH DRASTIC RESTRICTIONS. KJXN
IS THE TYPICAL EXCEPTION WITH LIFR CIGS ALREADY BEING REPORTED...
AND EXPECT THIS TO CONTINUE. AS IS ALREADY SEEN AT KMKG...WE
SHOULD SEE A FAIRLY QUICK TRANSITION TO MVFR/VFR CONDITIONS BY 12Z
AT MOST TERMINALS.
&&
.MARINE...
ISSUED AT 1045 PM EST WED FEB 22 2012
HAVE ALLOWED THE SMALL CRAFT ADVISORY TO EXPIRE. WINDS AND WAVES
WILL CONTINUE A RAPID DOWNWARD TREND.
&&
.HYDROLOGY...
ISSUED AT 400 PM EST WED FEB 22 2012
NO SIGNIFICANT HYDROLOGY ISSUES ARE EXPECTED AS THE PRECIPITATION
THAT FALLS WILL BE IN THE FROM FOR SNOW. NONE OF RIVERS ARE AT OR
ABOVE ACTION STAGE CURRENTLY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER STORM WATCH LATE THIS AFTERNOON THROUGH FRIDAY
MORNING FOR MIZ037>040-043>046-050>052-056>059-064>067-
071>074.
LM...NONE.
&&
$$
UPDATE...JK
SYNOPSIS...TJT
SHORT TERM...WDM
LONG TERM....NJJ
AVIATION...TJT
MARINE...TJT
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1203 AM EST THU FEB 23 2012
.UPDATE...
ISSUED AT 1047 PM EST WED FEB 22 2012
HAVE UPDATED FORECASTS TO REFLECT LESS SNOWFALL ACCUMULATION OVERNIGHT.
PRECIPITATION HAS SPREAD INTO SW LOWER MI AND RECENTLY CHANGED
OVER TO SNOW. WE ARE EXPECTING SLIGHTLY LESS TOTAL SNOWFALL THAN
BEFORE...AS THE BACK EDGE OF THIS PRECIPITATION ALREADY IS
SWEEPING ACROSS SW LOWER MI.
WE ARE WATCHING FOG DEVELOP JUST SOUTH OF I-94. A CLOUD LAYER
ASSOCIATED WITH THE PRECIPITATION SHOULD REDUCE THE FOG IN THE
NEXT FEW HOURS. AFTERWARDS WE MAY SEE SOME FOG REDEVELOP TOWARDS
SUNRISE...BUT NOTHING DENSE IS EXPECTED AT THIS TIME.
UPDATE ISSUED AT 650 PM EST WED FEB 22 2012
MADE TIMING ADJUSTMENTS TO PRECIPITATION CHANCES THROUGH 2 AM.
PRECIPITATION TYPE IS EXPECTED TO BE RAIN INITIALLY AS IT NOW IS
IN WI...THANKS TO CURRENT SURFACE TEMPERATURES AND DEWPOINTS OVER
MUCH OF LOWER MI. A GRADUAL CHANGEOVER TO SNOW SHOULD OCCUR MAINLY
AFTER 10 PM.
HRRR SHORT RANGE GUIDANCE CONTINUES TO SUPPORT A NARROW BAND OF
SNOW CROSSING THE I-96 CORRIDOR TONIGHT...AND THIS IS SUPPORTED BY
THE 22/12Z NCEP NESTED ARW/NMM NAM. IMPACTS ARE EXPECTED TO BE
MINIMAL GIVEN TIMING AND EXPECTED INTENSITY.
UPDATE ISSUED AT 444 PM EST WED FEB 22 2012
WILL BE ISSUING A WINTER STORM WATCH SHORTLY FOR THE CWA FROM
THURSDAY AFTERNOON INTO FRIDAY MORNING BASED LARGELY ON LATEST
ECMWF GUIDANCE. WILL TRY TO HAVE THE WATCH OUT BY 5 PM.
&&
.SYNOPSIS...
ISSUED AT 1045 PM EST WED FEB 22 2012
AFTER MOSTLY LIGHT PRECIPITATION MOVES THROUGH THE AREA OVERNIGHT...HIGH
PRESSURE WILL BRING CLEARING CONDITIONS TO THE AREA THURSDAY
MORNING. A STORM DEVELOPING IN THE SOUTHERN PLAINS WILL APPROACH
THE AREA DURING THE DAY THURSDAY...BRINGING A PERIOD OF
SIGNIFICANT SNOWFALL TO THE AREA THURSDAY NIGHT. SOME LAKE EFFECT
SNOW IS EXPECTED INTO SATURDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 400 PM EST WED FEB 22 2012
THERE IS THE THREAT FOR A SIGNIFICANT SNOWFALL EVENT THURSDAY
NIGHT INTO FRIDAY. CURRENT THINKING IS 4 TO 7 INCHES OVER THE
CENTRAL CWA... NEAR INTERSTATE 96. MOST OF THE SNOW SHOULD FALL
DURING THE MID TO LATE EVENING HOURS OF THURSDAY NIGHT INTO THE
MID MORNING HOURS OF FRIDAY.
THERE IS ALSO THE THREAT FOR A BRIEF BURST OF SIGNIFICANT SNOW THIS
EVENING AS A SHORTWAVE OVER WISCONSIN HEADS EAST ACROSS LAKE
MICHIGAN AND INTENSIFIES THIS EVENING. BOTH THE HRRR SUGGESTS UP
TO .25 INCHES OF QPF IN 3 HOURS OVER PARTS OF NORTHERN OTTAWA AND
CENTRAL AND NORTHERN KENT COUNTIES BY BETWEEN 9 PM AND MIDNIGHT.
SINCE THE PRECIPITATION AREA ALREADY IS OVER CENTRAL WISCONSIN AND
IS HEADED EAST... IT WOULD SEEM MORE THAN REASONABLE THIS WOULD
IMPACT CENTRAL LOWER MICHIGAN THIS EVENING. THERE IS GOOD LIFT IN
THE DGZ AS THIS FEATURE MOVES THROUGH THE AREA SO THAT SHOULD HELP
THE SNOWFLAKE PRODUCTION. WITH SURFACE DEW POINTS IN THE MID 20S
THE SNOW WILL WET BULB DOWN THE AIR TEMP QUICKLY SO SNOW WILL REACH
THE GROUND.
ONCE THAT FEATURE MOVES EAST OF THE CWA LATER THIS EVENING SHORT
WAVE RIDGING FOLLOWS LATE TONIGHT INTO MIDDAY THURSDAY. THAT
SHOULD ALLOW THE SKIES TO BECOME PARTLY CLOUDY...AT LEAST FOR A
TIME.
THEN WE HAVE THE ISSUE OF OUR STORM ON THURSDAY NIGHT. THE GFS AND
NAM HAVE BEEN CONSISTENTLY FARTHER NORTH THEN THE ECMWF HAS BEEN
WITH THIS SYSTEM. HOWEVER... THE ECMWF HAS FINALLY SHOWED A
SIGNIFICANT SHIFT NORTHWARD IN THE TRACK OF THE SYSTEM THURSDAY
NIGHT. THE REGIONAL GEM IS FARTHER NORTH AND WEST THAN IS THE
HEMISPHERIC GEM... TRACKING THE LOW NEAR DETROIT LATE THURSDAY
NIGHT. THERE IS SIGNIFICANT FGEN SUPPORT OF THIS EVENT AS IT IS
EXIT REGION OF 165 KNOT 300 MB JET CORE THAT TURNS CYCLONIC AS
IT HEADS NORTHEAST TOWARD CENTRAL OHIO FRIDAY MORNING. THIS ALSO
CREATES QUIET THE TROWAL FEATURE WITH STRONG ISOTROPIC LIFT. THERE
IS 3 TO 4 G/KG OF WATER NEAR 700 MB WHILE THIS IS GOING ON SO
SNOWFALL AMOUNTS OF 3 TO 6 INCHES SHOULD BE EASY TO DO WITH THIS
SET UP.
I WOULD HAVE ISSUED A WINTER STORM WATCH FOR THIS EVENT EXPECT FOR
THE ISSUE OF MODEL UNCERTAINTY. I WILL LET THE MIDNIGHT SHIFT
CONSIDER DOING JUST THAT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 400 PM EST WED FEB 22 2012
UNSETTLED/ACTIVE WEATHER IS EXPECTED TO GENERALLY CONTINUE THROUGH
THE LONG TERM PORTION OF THE FORECAST...IF NOT THE NEXT COUPLE OF
WEEKS. MAIN ITEMS OF CONCERN ARE LINGERING SNOW ON FRI...LAKE EFFECT
FRI NIGHT/SAT...SYSTEM COMING IN LATE SUN THROUGH MON...AND LAKE
EFFECT AGAIN ON TUE.
AN ACTIVE JET STREAM IS EXPECTED TO AFFECT MOST OF THE COUNTRY
THROUGH THE NEXT WEEK. WE ARE EXPECTING TO SEE STRONG PIECES OF
ENERGY BE PUSHED ACROSS THE COUNTRY...FUELED BY A VERY STRONG JET
OVER THE NRN PACIFIC. A LOT OF THIS ENERGY IS EXPECTED TO DIVE SE
INTO THE WRN STATES...BEFORE LIFTING E/NE TOWARD THE GREAT LAKES
REGION.
WE WILL SEE THE FIRST IN THE SERIES OF PV ANOMALIES/WAVES BE MOVING
OUT OF THE AREA AFTER DEPOSITING ACCUMULATING SNOW THU NIGHT AND
INTO FRI. IN THE WAKE OF THIS PHASED UPPER FEATURE...A POOL OF
ARCTIC AIR TO OUR NW WILL BE TAPPED AND WILL PUSH INTO THE AREA.
SYNOPTIC SNOW WILL LIKELY BE ONGOING EARLY ON FRI BEFORE TAPERING
OFF DURING THE DAY. THE SNOW WILL TRANSITION TO SOME LAKE EFFECT AS
H850 TEMPS DROP DOWN TO AROUND -10C TO -12C. WE COULD SEE SOME
DECENT LAKE EFFECT ACCUMS FOR MAINLY NW FAVORED AREAS WITH MOISTURE
POTENTIALLY UP THROUGH 10K FT LATE FRI AND FRI NIGHT. INVERSION
HEIGHTS WILL GRADUALLY FALL THROUGH SAT AS THE UPPER FLOW WILL
TRANSITION TO ANTI-CYCLONIC BY SAT EVENING.
WE WILL SEE A BRIEF BREAK IN THE WEATHER THEN SAT NIGHT THROUGH A
GOOD PORTION OF SUN FOR MOST AREAS AS RIDGING BUILDS IN. NW AREAS
COULD SEE SOME LIGHT PCPN SUN AFTERNOON AS WAA/ISENTROPIC ASCENT
STRENGTHENS AHEAD OF THE NEXT SYSTEM. THE UNSETTLED WEATHER WILL
SPREAD ACROSS THE ENTIRE AREA SUN NIGHT AS THE NEXT STRONG WAVE
DIVING INTO THE SW U.S. EARLY IN THE WEEKEND WILL LIFT NE. THIS WILL
LIKELY TAP SOME WARMER AND MOIST AIR FROM THE GULF AND ADVECT IT
INTO THE AREA LATE SUN THROUGH MON MORNING. PCPN COULD START OFF AS
SNOW...BUT SHOULD CHANGE OVER TO RAIN FOR A PERIOD SUN NIGHT AND
EARLY MON. THUNDER CAN NOT EVEN BE RULED OUT WITH THE STRONG FORCING
ASSOCIATED WITH THE SYSTEM. NOT CONFIDENT ENOUGH YET TO ADD THUNDER
INTO THE FCST.
THE COLD FRONT WILL MOVE THROUGH ON MON...AND A FLOOD OF COLDER AIR
WILL MOVE IN ACROSS THE STATE. THIS WILL HELP TO START THE LAKE
EFFECT BACK UP AS H850 TEMPS DROP BACK DOWN TO AROUND -10C TO -12C.
MODELS ARE INDICATING THOUGH THAT THE LOW LEVEL FLOW WILL TEND TO BE
NE WITH THE WAY THE RIDGE BUILDS IN FROM THE NW. THIS WILL TEND TO
LIMIT THE LAKE EFFECT CHCS AND AMOUNTS. QUITE A BIT OF UNCERTAINTY
WITH REGARDS TO TIMING AND TRACK WITH ANOTHER WAVE THAT IS EXPECTED
TO LIFT OUT FROM THE WRN U.S. BY MID WEEK NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1156 PM EST WED FEB 22 2012
BRIEFLY SAW IFR VISIBILITY AT KGRR WITH LARGE SNOWFLAKES FALLING.
THE ASSOCIATED AREA OF HEAVIER PRECIPITATION MOVING EAST TOWARDS
KLAN SHOULD BE PREDOMINANTLY SNOW AND BRING...BREIF IFR VSBYS
THERE TOO. ELSEWHERE...DO NOT EXPECT SUCH DRASTIC RESTRICTIONS. KJXN
IS THE TYPICAL EXCEPTION WITH LIFR CIGS ALREADY BEING REPORTED...
AND EXPECT THIS TO CONTINUE. AS IS ALREADY SEEN AT KMKG...WE
SHOULD SEE A FAIRLY QUICK TRANSITION TO MVFR/VFR CONDITONS BY 12Z
AT MOST TERMINALS.
&&
.MARINE...
ISSUED AT 1045 PM EST WED FEB 22 2012
HAVE ALLOWED THE SMALL CRAFT ADVISORY TO EXPIRE. WINDS AND WAVES
WILL CONTINUE A RAPID DOWNWARD TREND.
&&
.HYDROLOGY...
ISSUED AT 400 PM EST WED FEB 22 2012
NO SIGNIFICANT HYDROLOGY ISSUES ARE EXPECTED AS THE PRECIPITATION
THAT FALLS WILL BE IN THE FROM FOR SNOW. NONE OF RIVERS ARE AT OR
ABOVE ACTION STAGE CURRENTLY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER STORM WATCH FROM THURSDAY AFTERNOON THROUGH FRIDAY
MORNING FOR MIZ037>040-043>046-050>052-056>059-064>067-
071>074.
LM...NONE.
&&
$$
UPDATE...TJT
SYNOPSIS...TJT
SHORT TERM...WDM
LONG TERM....NJJ
AVIATION...TJT
MARINE...TJT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1145 PM CST WED FEB 22 2012
.DISCUSSION...
UPDATED PREVIOUS FORECAST AND RESOLVED WATCH INTO ADVISORY FOR
MAINLY ALONG THE INTERSTATE 90 CORRIDOR. 2-4 INCHES POSSIBLE
THERE. MODELS TRENDED TO A MORE SOUTHERLY TRACK BEGINNING WITH THE
00Z RUC.
&&
.AVIATION.../06Z TAF ISSUANCE/
MODELS SHIFTED MAIN SNOW ACTIVITY WELL SOUTH OF TAF SITES. MAY SEE
SOME FLURRIES INTO THE AFTERNOON AND MAINTAINED A VCSH FOR THAT
AT SEVERAL MN SITES. MVFR CIGS DEVELOPING OVER THE WESTERN
AREAS...WITH SOME FOG AS WELL...AS LOW CLOUDS MOVES EAST THIS
EVENING. WILL MENTION SOME MVFR BR AT KAXN WITH CEILINGS GOING IFR
DURING THE EARLY MORNING. AT THIS TIME WILL DROP CEILINGS DURING
THE DAY IN MN TO MVFR AND WILL MAINTAIN VFR AT KEAU UNTIL EVENING.
REAL CHANCE OF SNOW TO COME WITH NEXT WAVE ROTATING SOUTHEAST
BEHIND THE DEPARTING SYSTEM LATER TONIGHT AND DID MENTION THAT
VCSH/-SN AT MN LOCATIONS. LIGHT WINDS BECOMING MORE EAST OVERNIGHT
AND EVENTUALLY NORTHWEST LATE TONIGHT IN THE WAKE OF THE IOWA LOW.
SHOULD REMAIN MAINLY BELOW 10 KNOTS THROUGH THE TAF PERIOD.
KMSP...EXPECT VFR CONDITIONS UNTIL ABOUT 11Z THEN MVFR THROUGH THE
DAY AS IOWA SYSTEM EXITS TO THE EAST DID MENTION VCSH FOR POSSIBLE
FLURRIES INTO THE AFTERNOON...WITH THE BETTER CHANCE OF FLURRIES
MOVING IN OVERNIGHT AS ANOTHER TROUGH MOVES IN BEHIND THE INITIAL
SYSTEM. WILL SEE EAST SURFACE WINDS BECOMING MORE NORTH DURING THE
DAY AS SYSTEM EXITS TO THE EAST. SHOULD REMAIN BELOW 10 KNOTS
THROUGH THE PERIOD.
&&
.PREV DISCUSSION...
/ISSUED 522 PM CST WED FEB 22 2012/
SUMMARY...QUITE THE DAY HERE AT THE NWS OFFICE TODAY. THREE
POTENTIAL SNOW STORMS IN THE FORECAST AREA OVER THE NEXT 160 HOURS
AND PLENTY OF MODEL DISAGREEMENT TO GO ALONG WITH IT.
FIRST THINGS FIRST...SHORTWAVE PASSING THROUGH THIS AFTERNOON
YIELDING ISOLATED TO SCATTERED LIGHT SNOW SHOWERS...SHOULD BE
THROUGH EARLY THIS EVENING AND LOOKS DRY FOR SEVERAL HOURS BEFORE
THE SURFACE LOW FROM THE NORTHWEST. LOOK OF POTENTIAL WITH THIS
STORM FOR TONIGHT...BUT THE QUESTION TODAY HAS NOT BEEN IF THERE
WILL BE A 6+" SNOWBAND...BUT WHERE. IN GENERAL...THERE HAS BEEN
TWO CLUSTERS OF MODEL GUIDANCE: THE UKMET/EC IN ONE CAMP AND THE
GFS/GEM/SREF/ IN THE OTHER. THE 12Z NAM WAS AN OUTLIER TO THE
NORTH AND BROUGHT THE HEAVY SNOW ACROSS CENTRAL MN...INCLUDING THE
TWIN CITIES METRO. THE 18Z NAM JOINED THE GFS/SREF/GEM CAMP AND
CAME IN MUCH FURTHER SOUTH. DEBATED ON UPGRADING THE WATCH TO A
COMBINATION OF WARNING/ADVISORY WITH THE HEAVIEST ACCUMULATIONS IN
MARTIN AND FARIBAULT COUNTIES. IN FACT...EVEN HAD THE WARNING
DRAWN UP LATE THIS AFTERNOON...BUT THE LAST FRAME OF THE HRRR
AGREES QUITE WELL WITH THE ECMWF AND WOULD KEEP ALMOST ALL OF THE
SNOW OUT OF THE FORECAST AREA.
THERE IS ALREADY A LIGHTNING STRIKE UPSTREAM IN MONTANA THIS
AFTERNOON...WHICH IS USUALLY A PRETTY GOOD INDICATOR OF THE
STRENGTH OF THIS SYSTEM. NO SURPRISE WITH 992-993MB SURFACE LOW
DROPPING SOUTH ACROSS WESTERN IA BASED ON THE NAM/GFS...THERE IS
VERY GOOD 800-600MB FGEN TO GO ALONG WITH NEGATIVE EPV AND AT
LEAST SOME ELEVATED INSTABILITY-BEST LI APPROACHES THE FORECAST
AREA WITH 2/3 GRAM MIXING RATIOS OFF THE ISENTROPIC SURFACES. THE
FORECAST SIDES WITH THE GFS/GEM/NAM/SREF CLUSTER OF SOLUTIONS.
HOWEVER...LOW CONFIDENCE WITH NOW THE LATEST HRRR AGREEING QUITE
WELL WITH THE ECMWF. IT`S A FEAST OF FAMINE SITUATION-THERE WILL
LIKELY BE 6-10 INCHES...POSSIBLY A FOOT...IN A NARROW CORRIDOR
WHERE THE BEST FORCING SETS UP AND NOT MUCH TO THE NORTH OF IT.
DRAMATICALLY REDUCED POPS AND AMOUNT OF SNOW IN METRO...MIGHT BE
NOTHING AT. USUALLY GOOD SUBSIDENCE ON NORTH SIDE OF THE
DEFORMATION.
IN THE EXTENDED...THE SUNDAY/MONDAY SYSTEM LOOKS POTENT...JUST NOT
SOME MUCH FOR HERE WITH THE SURFACE LOW TRACKING OVERHEAD AND HIGH
POTENTIAL FOR DRY SLOT BASED ON THE ASSORTMENT OF OPERATIONAL RUNS
AND ENSEMBLE GUIDANCE. UNLESS SOMETHING CHANGES...A LOT OF SNOW
AND WIND IN THE DAKOTAS AND NORTHERN MN AND NOT MUCH HERE. GFS
SPITS OUT THE HIGHEST QPF...BUT IT MIGHT BE OVERDONE. THERE ARE
FAIRLY HIGH POPS IN THE FORECAST...BUT OVERALL...DOESN`T LOOK LIKE
ANYTHING MAJOR IN THE IMMEDIATE AREA. THERE`S ANOTHER WHOPPER OFF
THE GFS THIS TIME NEXT...BUT NOT SHOWING UP AS MUCH ON THE ECMWF
AND GFS ENSEMBLE TO SOME DEGREE. THE 12Z GFS HAD A BAND OF 12-18"
IN SOUTHERN MN...SOMETHING THAT WILL LIKELY CHANGE WITH TIME.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM CST THURSDAY FOR
FARIBAULT-FREEBORN-MARTIN-WATONWAN.
WI...NONE.
&&
$$
DWE/JVM
AREA FORECAST DISCUSSION
NWS BILLINGS MT
925 PM MST WED FEB 22 2012
.SHORT TERM...VALID FOR THU AND FRI...
WE UPDATED THE FORECAST TO DROP THE HIGH WIND WARNING AND TO ISSUE
A WINTER WEATHER ADVISORY FOR CARTER AND FALLON COUNTIES THROUGH 6
AM MST THU MORNING. AT 04 UTC...A SURFACE LOW IS LOCATED VERY NEAR
BUFFALO SD...WHICH IS NOTABLY SOUTHWEST OF WHERE MOST MODELS WOULD
PLACE IT AT THIS TIME. THIS IS A REFLECTION OF THE LOW-LEVEL FRONT
AND UPPER-LEVEL JET STREAK DRIVING THE SURFACE WAVE BOTH ENDING UP
FURTHER SOUTHWEST THAN ANTICIPATED. BASED ON THE LAST FEW RUC RUNS
AND DOWNSTREAM PRESSURE FALLS CENTERED NEAR WINNER SD AT 04 UTC...
WE FEEL THE PATH OF THIS DYNAMIC WAVE WILL END UP BRINGING IMPACTS
TO SOUTHEASTERN MT OVERNIGHT. THE RUC...AND TO SOME EXTENT THE NEW
00 UTC GFS...CALLS FOR A POTENT AREA OF FRONTOGENESIS NEAR 700 HPA
AND 500-300 Q-VECTOR CONVERGENCE AS FAR WEST AS BAKER AND EKALAKA.
THIS DEFORMATION-ZONE PRECIPITATION COULD AMOUNT TO SEVERAL INCHES
OF SNOW...THOUGH ITS EXACT PLACEMENT IS A LOW-CONFIDENCE ITEM WITH
THE UNCERTAINTY TIED TO THIS DYNAMIC WAVE. EVEN SO...WE STILL HAVE
ENOUGH CONFIDENCE IN THE TRENDS TO CALL FOR 2 TO 5 INCHES OF SNOW
OVER CARTER AND FALLON COUNTIES.
MOISTURE-LADEN NORTHWEST FLOW CONTINUES DELIVERING HEAVY SNOW INTO
THE MOUNTAINS...SO WE WILL CONTINUE WITH THE GOING WARNINGS THERE.
WE STILL HAVE SOME CONCERN FOR THE BAND OF SNOW MOVING THROUGH RED
LODGE...BUT TRENDS SUGGEST IT WILL DIMINISH ENOUGH TO KEEP US FROM
NEEDING AN ADVISORY. THAT WILL MAINLY BE TIED TO LOW-LEVEL FLOW IN
THE FOOTHILLS TURNING MORE WESTERLY THOUGH...SO IF WE DO NOT START
SEEING THAT HAPPEN IN THE NEXT FEW HOURS A SHORT-FUSE HEADLINE MAY
STILL BE REQUIRED.
FINALLY...DESPITE A 3-HOUR SURFACE PRESSURE RISE ON THE ORDER OF 8
HPA DROPPING THROUGH SOUTH CENTRAL MT...WINDS ALOFT HAVE DECREASED
ENOUGH TO BRING AN END TO THE HIGH WINDS. WE COULD END UP CLOSE TO
CRITERIA IN SOUTHEASTERN MT AND NEAR SHERIDAN WY FOR A WHILE...BUT
THIS THREAT WAS NOT ENOUGH TO KEEP THE WARNING GOING. SCHULTZ
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
MEDIUM RANGE MODELS CONTINUE TO INDICATE A MODERATION IN
TEMPERATURES FOR SATURDAY THROUGH MONDAY. BOTH THE GFS AND ECMWF
ARE IN GOOD AGREEMENT SATURDAY IN SLOWING THE ARRIVAL OF THE COLD
FRONT INTO THE EARLY EVENING HOURS. SOUTHWEST FLOW ALOFT AND AT
THE SURFACE AHEAD OF THE FRONT WILL ALLOW FOR THE POSSIBILITY OF
DOWNSLOPE WINDS FROM BILLINGS WESTWARD RESULTING IN WARMER
TEMPERATURES THAN PREVIOUSLY ANTICIPATED. AS A RESULT OF THE
SLOWER ARRIVAL OF THE FRONT...HAVE SCALED BACK POP CHANCES
SOMEWHAT FOR THE DAY BUT KEPT HIGHER CHANCES FOR THE EVENING AND
OVERNIGHT HOURS. STILL LOOKS TO BE A RAIN AND SNOW SHOWER TYPE OF
PRECIP AHEAD AND ALONG THE FRONT CHANGING TO ALL SNOW BEHIND THE
FRONT SATURDAY NIGHT AS COLDER AIR FILTERS INTO THE AREA. HAVE
MODERATED SATURDAY NIGHT AND SUNDAY NIGHT LOWS SEVERAL
DEGREES...ESPECIALLY SATURDAY NIGHT...AS WELL AS WARMED
TEMPERATURES UP SEVERAL DEGREES FOR SUNDAY AND MONDAY. CAN`T
REALLY CALL THIS AN ARCTIC FRONT ANYMORE GIVEN THE FACT OVERNIGHT
LOWS SATURDAY NIGHT ARE ONLY EXPECTED IN THE TEENS WITH HIGHS IN
THE 20S FOR SUNDAY. HOWEVER...LOWER 20S IS STILL ABOUT 20 DEGREES
BELOW NORMAL FOR THIS TIME OF YEAR. GUIDANCE IS ACTUALLY GIVING
THE AREA 40S FOR HIGHS SATURDAY AND SUNDAY WITH UPPER 30S MONDAY.
DID NOT WARM READINGS UP THIS MUCH BUT IF GUIDANCE CONTINUES THIS
TREND READINGS MAY HAVE TO BE NUDGED HIGHER WITH LATER SHIFTS.
OVERALL PATTERN CONTINUES TO LOOK UNSETTLED FOR THE REMAINDER OF
NEXT WEEK WITH TEMPERATURES SLIGHTLY BELOW NORMAL. HOOLEY
&&
.AVIATION...
SCATTERED RAIN AND SNOW SHOWERS WILL TURN OVER TO ALL SNOW LATE
THIS EVENING. AREAS EAST OF A MILES CITY TO BROADUS LINE WILL SEE
PERIODS OF IFR OR LOWER CONDITIONS LATE TONIGHT INTO TOMORROW
MORNING DUE TO SNOWFALL. AREAS IN THE FOOTHILLS AND MOUNTAINS WILL
ALSO SEE PERIODS OF IFR OR LOWER CONDITIONS WITH SNOWFALL AND
STRONG WINDS PRODUCING BLOWING SNOW. WINDS OVER MOST LOCATIONS
WILL DIMINISH THROUGH THE NIGHT...THOUGH OCCASIONAL GUSTS AROUND
40 KTS WILL BE POSSIBLE THROUGH AT LEAST MIDNIGHT AT ALL TAF
LOCATIONS. EXPECT CONDITIONS TO IMPROVE FROM NORTH TO SOUTH DURING
THE EARLY MORNING HOURS. CHAMBERS
&&
.PRELIMINARY POINT TEMP/POPS...
THU FRI SAT SUN MON TUE WED
-----------------------------------------------------------
BIL 028/039 020/036 022/040 018/023 009/024 011/035 016/039
43/W 21/B 13/W 44/J 22/J 11/B 11/B
LVM 022/034 013/033 021/038 016/022 007/023 009/034 014/037
43/J 21/E 24/J 44/J 23/J 21/B 11/N
HDN 026/040 020/040 019/042 020/023 012/024 012/035 018/041
73/W 31/B 13/W 44/J 22/J 11/B 01/B
MLS 026/037 020/035 018/038 018/020 006/021 008/032 016/037
83/J 32/J 13/J 44/J 22/J 11/B 00/B
4BQ 024/037 018/037 017/044 020/025 011/025 008/034 018/039
73/J 42/J 12/J 44/J 21/E 11/B 00/U
BHK 025/031 016/030 014/035 019/019 005/020 008/031 017/036
+4/J 12/J 12/J 44/J 21/E 11/B 11/U
SHR 026/035 016/035 017/043 021/024 008/025 010/034 019/038
75/J 22/J 13/W 44/J 22/J 21/B 00/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL 6 AM MST THURSDAY FOR
ZONES 33-37.
WINTER STORM WARNING IN EFFECT UNTIL 5 AM MST THURSDAY FOR
ZONE 67.
WY...WINTER STORM WARNING IN EFFECT UNTIL 5 AM MST THURSDAY FOR
ZONE 98.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
348 AM CST THU FEB 23 2012
.SHORT TERM...TODAY THROUGH SATURDAY
FORECAST FOCUS THROUGH THIS PERIOD IS ON WINDS AND SNOW POTENTIAL
TODAY.
AT 08Z...WATER VAPOR IMAGERY SHOWED A LARGE RIDGE OVER THE EASTERN
PACIFIC WITH TROUGHING ACROSS THE EASTERN HALF OF THE
CONUS...LEAVING THE CENTRAL STATES IN NORTHWEST FLOW. IN THIS
FLOW...A SHORTWAVE TROUGH WAS SEEN OVER SOUTHEAST IDAHO...WHILE
THE WAVE OF IMMEDIATE CONCERN FOR THE LOCAL AREA WAS OVER EASTERN
MONTANA INTO WESTERN NORTH DAKOTA AND NORTHWEST SOUTH DAKOTA. AT
THE SURFACE...THE COLD FRONT HAD PASSED ACROSS THE FORECAST AREA
AND WAS LOCATED FROM THE SURFACE LOW IN SOUTH CENTRAL SOUTH
DAKOTA THROUGH KONL TO KHDE TO KHLC THEN WEST INTO EAST CENTRAL
COLORADO. THE PRESSURE GRADIENT BEHIND THE FRONT WAS TIGHTENING
WITH WINDS ON THE INCREASE OVER WESTERN SOUTH DAKOTA AND THE
NEBRASKA PANHANDLE. TEMPERATURES REMAINED IN THE MID TO UPPER 30S
IN MOST LOCATIONS...HOWEVER LOOKING UPSTREAM BEHIND THE
FRONT...THINGS WERE BEGINNING TO SLOWLY COOL DOWN. LOOKING AT
RADAR...A LARGE VORTEX OF PRECIPITATION WAS SPINNING AROUND THE
700MB LOW OVER SOUTH DAKOTA. THE WESTERN PORTION OF THIS WAS OVER
THE BLACK HILLS AND THE WHOLE AREA WAS SLOWLY MOVING TO THE
SOUTHEAST. NOT MUCH WAS BEING REPORTED WITH THIS AREA OF
PRECIPITATION THOUGH...WITH JUST LIGHT SNOW WITH NO ACCUMULATIONS
YET AT KRAP.
THE LATEST RUC WOULD TAKE THE LOW OVER SOUTH DAKOTA SOUTHEAST
ACROSS NORTHEAST CHERRY AND KEYA PAHA COUNTIES THROUGH GARFIELD
AND WHEELER COUNTIES AND THEN CONTINUING SOUTHEAST ACROSS GID/S
FORECAST AREA. THE TIGHTEST PRESSURE GRADIENT SHOULD BE JUST TO
THE WEST OF THE LOW...SO THIS TRACK WOULD SUGGEST THE STRONGEST
WINDS WOULD BE ACROSS THE CENTRAL AND SOUTHEASTERN PARTS OF THE
FORECAST AREA THROUGH THE DAY. THERE REMAINS QUESTION OF HOW
STRONG THESE WINDS WILL BE. MAV GUIDANCE SEEMS TO BE TOO HIGH
GIVING 44KT SUSTAINED WINDS AT KBBW AND 41KT SUSTAINED AT KLBF.
SO ALTHOUGH EXPECTING HIGH WINDS...DIDN/T GO AS HIGH AS THAT
GUIDANCE. CURRENTLY THINKING TODAY/S WINDS WILL BE A HIGH END
ADVISORY...BUT WILL NEED TO KEEP AN EYE ON THINGS AS KRAP /WHICH
IS CURRENTLY JUST WEST OF THE LOW HAS HAD A PEAK GUST TO 54KTS
ALREADY. LUCKILY...WINDS ALOFT LOOK TO DECREASE THROUGH THE DAY AS
HIGHEST MIXING IS ACHIEVED AS TH 925MB AND 850MB WINDS FROM THE
KUNR VWP WERE AT 50KTS AND 55KTS RESPECTIVELY...WHILE BUFKIT
SOUNDINGS FROM THE NAM SHOWED UP TO 65KTS AROUND 800MB. AS THE
WINDS WERE ALREADY COMING UP...DID START THE WIND ADVISORY EARLY
/10Z FOR THE NORTHWEST TWO-THIRDS OF THE FORECAST AREA/ WITH THE
SOUTHEAST TIER BEGINNING NOW AT 14Z RATHER THAN 15Z. THE PRESSURE
GRADIENT WILL LESSEN THIS AFTERNOON...BUT WITH VERY STEEP LAPSE RATES
WITH THE COLD AIR ADVECTION INFLUENCING THE MIXING POTENTIAL...WILL
CONTINUE TO SEE BREEZY CONDITIONS THROUGH THE AFTERNOON.
IN TERMS OF THE SNOW...THE PRECIPITATION OVER THE BLACK HILLS
SHOULD ROTATE SOUTHEAST INTO NORTH CENTRAL NEBRASKA AND CONTINUE
TO THE SOUTHEAST TODAY. DON/T HAVE A GOOD HANDLE ON HOW MUCH QPF
WILL BE WITH THIS AS MODELS RANGE FROM A FEW HUNDREDTHS TO AROUND
A QUARTER INCH. BELIEVE THE LARGER AMOUNTS MAY BE A BIT HIGH DUE
TO WHAT IS CURRENTLY SEEN ON RADAR AND WITH ONLY A FEW STATIONS
REPORTING PRECIPITATION SO DIDN/T GO THAT ROBUST IN THE FORECAST.
CURRENTLY HAVE UP TO 2 INCHES OF SNOW ACCUMULATION THROUGH THE DAY
FROM MERRIMAN TO THEDFORD TO BROKEN BOW. DID KEEP THE
PRECIPITATION TYPE AS SNOW COLD AIR WILL CONTINUE TO PUSH SOUTH
KEEPING TEMPERATURES IN THESE AREAS FROM RISING MUCH AND WITH
TEMPERATURES ALOFT COOLING...PRECIPITATION WILL FALL AS
SNOW...WHILE IT MAY MELT UPON REACHING THE GROUND. ONE CONCERN
WILL BE IF THIS SNOW WILL HAVE ANY IMPACT DUE TO THE WINDS. EVEN
THOUGH IT WILL BE LIGHT SNOW SHOWERS...WINDS BLOWING AT 40 TO 50
MPH COULD CAUSE REDUCED VISIBILITIES. HELD OFF ON PUTTING OUT ANY
WINTER WEATHER HEADLINES BECAUSE OF THE LIGHTER SNOW AMOUNTS
EXPECTED BUT WILL PUT OUT A SPECIAL WEATHER STATEMENT TO INFORM
USERS OF POTENTIAL IMPACTS.
TEMPERATURES WILL STAY BELOW NORMAL FOR FRIDAY WITH HIGHS ONLY IN
THE MID 30S TO LOW 40S AS NORTHWEST FLOW STAYS IN PLACE KEEPING
THE COOLER AIR OVER THE AREA. LAPSE RATES WILL REMAIN STEEP DUE TO
THE COLDER AIR ALOFT AND AS A WEAK SHORTWAVE TROUGH PASSES ACROSS
THE AREA...MAY SEE SOME SCATTERED SNOW SHOWERS THROUGH THE DAY.
DON/T EXPECT ANYTHING WIDESPREAD OR MUCH FOR ACCUMULATIONS...BUT
FELT IT DEEMED ADDING IN A SLIGHT CHANCE.
RIDGING BUILDS IN FOR SATURDAY...AND WITH MODELS SHOWING ABUNDANT
DRY AIR...SHOULD SEE QUITE A BIT OF SUNSHINE. TEMPERATURES WILL
WARM AS SOUTHERLY SURFACE FLOW BRINGS WARMER AIR NORTHWARD SO
LOOKING AT TEMPERATURES RISING TO ABOVE NORMAL VALUES WHICH ARE LOW
TO MID 40S.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
STILL LOOKS LIKE A RATHER SIGNIFICANT SYSTEM WILL PASS ACROSS THE
NORTHERN PLAINS ON SUNDAY. THE TREND SINCE YESTERDAY DOES LOOK TO
BE A BIT TO THE NORTH WITH THE UPPER LEVEL SYSTEM SO THE MAJORITY
OF THE SNOW WILL FALL ACROSS THE DAKOTAS. THE OPERATIONAL GFS
SOLUTION IS ONE OF THE MORE SOUTHERLY SOLUTIONS OF THE ENSEMBLE
MEMBERS...WITH THE MEAN BEING CLOSER TO THE ECMWF. BUT TO LEAVE A
CHANCE FOR A SOUTHERLY SHIFT...SLIGHT CHANCES FOR SNOW LOOK TO BE
GOOD FOR SUNDAY AND SUNDAY NIGHT ACROSS NORTHERN NEBRASKA. THE
SURFACE LOW IS NOW LOOKING LIKE IT WILL MOVE ACROSS SOUTH
DAKOTA...WITH THE COLD FRONT QUICKLY MOVING ACROSS THE FORECAST
AREA BY MID MORNING ON SUNDAY. LOOKS LIKE BREEZY NORTHWEST WINDS
ACROSS NEBRASKA...WITH THE MORE ROBUST WINDS JUST TO THE WEST OF
THE LOW OVER THE DAKOTAS WHERE THE PRESSURE GRADIENT WILL BE
TIGHTEST. ALSO...WITH THE NORTHERLY SHIFT...TEMPERATURES MAY STAY
A BIT WARMER ON SUNDAY. STILL EXPECTING BELOW NORMAL FOR
HIGHS...BUT WITH THIS TRACK...WOULD EXPECT HIGHS IN THE MID 30S TO
MID 40S RATHER THAN MID 20S TO 40 DEGREES AS IT LOOKS TO THE
NORTH. HIGH PRESSURE BUILDS SOUTH FOR MONDAY...WITH DRY
CONDITIONS...BUT COLDER AS 850MB TEMPERATURES STAY BELOW 0C ACROSS
THE ENTIRE FORECAST AREA. THE GFS HAS 850MB TEMPERATURES OVER
NORTHERN NEBRASKA AT -7C TO -9C. MEANWHILE...ANOTHER SYSTEM LOOKS
TO DIG TOWARDS THE FOUR CORNERS WITH A SURFACE LOW DEVELOPING
OVER NEW MEXICO MONDAY NIGHT. THE WARM FRONT WITH THIS SYSTEM IS
CURRENTLY PROJECTED TO LIFT INTO KANSAS MONDAY NIGHT...WITH
MOISTURE AND LIFT OVERRUNNING THE FRONT BRINGING PRECIPITATION
INTO NEBRASKA. THE GFS BREAKS THIS PRECIPITATION OUT BY 06Z WHILE
THE ECMWF IS SLIGHTLY DELAYED. SURFACE FEATURES ARE FAIRLY
SIMILAR...BUT THE UPPER LEVEL TROUGH IS MUCH MORE AMPLIFIED AND
POSITIVELY TILTED. THE ECMWF DOES SHOW STRONG ISENTROPIC LIFT IN
THE 285K TO 295K SURFACES...AS WELL AS GOOD MOISTURE TRANSPORT
INTO SOUTHWEST NEBRASKA ON THE 285K SURFACE. SO WHEREVER THE
SYSTEM TRACKS...THERE IS CERTAINLY POTENTIAL FOR SOME DECENT
PRECIPITATION. AT THIS POINT WILL STICK TO THE CONSENSUS OUTPUT AS
PLENTY CAN CHANGE WITH THIS SYSTEM OVER THE NEXT WEEK.
&&
.AVIATION...
A POWERFUL WINTER CYCLONE WILL RAPIDLY TRACK THROUGH THE MISSOURI
BASIN TODAY. LIFR/IFR/MVFR IN SN...BLSN AND LOW CIGS SHOULD DEVELOP
ALONG HIGHWAY 20 AROUND 12Z AND CONTINUE THROUGH 21Z. MVFR IS
EXPECTED ALONG AND EAST OF HIGHWAY 183 21Z-03Z. VFR IS EXPECTED BY
03Z ACROSS THE ENTIRE FCST AREA.
ELSEWHERE...VFR/MVFR IS EXPECTED TODAY AND TONIGHT. FLIGHT
CONDITIONS WILL IMPROVE SOUTHWARD FROM HIGHWAY 20.
WINDS INCREASE TO 32030G45KT AROUND 12Z AND CONTINUE STRONG THRU 23Z
TODAY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY FROM 8 AM CST /7
AM MST/ THIS MORNING TO 6 PM CST /5 PM MST/ THIS EVENING FOR
NEZ028-029-038-058-059-069>071.
WIND ADVISORY UNTIL 6 PM CST /5 PM MST/ THIS EVENING FOR
NEZ004>010-022>027-035>037-056-057-094.
&&
$$
SHORT/LONG TERM...BROOKS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BUFFALO NY
437 AM EST THU FEB 23 2012
.SYNOPSIS...
HIGH PRESSURE WILL BRIEFLY RIDGE ACROSS THE REGION TODAY. LOW
PRESSURE WILL LIFT TOWARD THE EASTERN LAKES TONIGHT...INTENSIFYING
AS IT TRACKS ACROSS NEW ENGLAND FRIDAY NIGHT. THIS WILL BRING SOME
RAIN AND SNOW TO THE REGION TONIGHT INTO FRIDAY. AS THE LOW EXITS
INTO THE MARITIMES...IT WILL BRING COLDER AIR AND LINGERING SNOW
SHOWERS FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THROUGH THE EARLY MORNING HOURS...LINGERING AREAS OF SNOW WILL EXIT
EAST. SNOW SHOULD BE DONE IN MOST AREAS...WITH ALL ACCUMULATING SNOW
EXPECTED TO BE DONE BY DAYBREAK. HRRR MODEL HAS SNOW BANDS WELL
FORECAST...WITH THIS THE PREFERRED MODEL IN THE ULTRA-SHORT TERM.
AFTER THIS...WEAK SURFACE HIGH PRESSURE WILL BRIEFLY BUILD ACROSS
THE REGION. AN UPPER LEVEL DISTURBANCE EMBEDDED IN THE 500 MB FLOW
WILL PASS. WHILE IT APPEARS TO DRY FOR THIS FEATURE TO CAUSE ANY
PRECIPITATION...IT WILL LIKELY CAUSE CLOUDS TO LINGER FOR MUCH OF THE
MORNING HOURS. OTHERWISE...TEMPERATURES SHOULD CLIMB TO THE LOWER
40S IN MOST LOCATIONS...IN THE UPPER 30S ACROSS HIGHER TERRAIN AND
EAST OF LAKE ONTARIO.
THINGS GET A BIT MORE COMPLEX FOR TONIGHT AS LOW PRESSURE IS
FORECAST TO TRACK FROM THE OHIO VALLEY TOWARD THE REGION. MODEL
GUIDANCE IS IN POOR AGREEMENT FOR THIS TIMEFRAME...WITH SIGNIFICANT
MODEL DIFFERENCES IN STRENGTH AND TRACK OF THE LOW LEADING TO
DIFFERING THERMAL PROFILE FORECASTS. FOR EXAMPLE...THE LATEST RUN OF
THE EUROPEAN HAS A 998 MB LOW NEAR EASTERN OHIO ON 12Z FRIDAY
MORNING...WHILE THE NAM HAS A 985 MB LOW ACROSS LAKE ERIE. GIVEN THE
SPREAD OF SOLUTIONS...CONFIDENCE REMAINS LOWER THAN NORMAL FOR
TONIGHTS FORECAST. CLIMATOLOGICALLY SPEAKING...THE FAVORED TRACK FOR
THE SURFACE LOW WOULD BE ACROSS LAKE ERIE/ONTARIO. THIS IS BEST
REPRESENTED BY THE NAM/GFS/SREF SOLUTIONS...THOUGH THESE MODELS STILL
DIFFER ON HOW QUICKLY WARM AIR ALOFT WILL BUILD IN. FEEL THE MOST
LIKELY SOLUTION IS REFLECTED BY A NAM/GFS/SREF BLEND IN TRACK AND
TEMPERATURES ALOFT.
SO FOR TONIGHT...A BROAD AREA OF WARM AIR ADVECTION PRECIPITATION
WILL LIFT TOWARD THE REGION FROM THE SOUTH. DESPITE MODEL
DIFFERENCES...THERE IS GENERAL MODEL AGREEMENT ON THIS...WITH HIGH
CONFIDENCE IN MEASURABLE PRECIPITATION SOUTH OF LAKE ONTARIO.
PRECIPITATION WILL LIKELY START AS A MIX OF RAIN AND SNOW IN MOST
AREAS. PRECIPITATION SHOULD START DURING THE EVENING HOURS SOUTH OF
LAKE ONTARIO...AND AFTER MIDNIGHT ACROSS AND EAST OF THE LAKE...AND
TOWARD DAYBREAK WATERTOWN NORTHWARD. HERE IS WHERE THERE ARE
SIGNIFICANT MODEL DIFFERENCES...BUT DO FEEL AT LEAST A COUPLE HOURS
OF MODERATE SNOWFALL IS LIKELY IN MOST LOCATIONS. WEST OF
ROCHESTER...IT LOOKS LIKE 1 TO 3 INCHES OF SNOW BEFORE THE
CHANGEOVER TO RAIN. EAST OF ROCHESTER...IT WILL BE FURTHER FROM THE
LOW...WITH THERMAL PROFILES SUGGESTING THAT COLD AIR ALOFT WILL HANG
ON A BIT LONGER. FOR NOW...LOOKING FOR 2 TO 4 INCHES FROM ROCHESTER
EAST...INCLUDING THE NORTHERN FINGER LAKES REGIONS AND OSWEGO
COUNTY. THIS WILL BE A WET SNOW...POSSIBLY MIXED WITH SLEET AT
TIMES. QPFS SHOULD RANGE IN THE .25 TO .50 INCH RANGE THROUGH
DAYBREAK FRIDAY MORNING...LESS THAN THAN IN FAR NORTHERN SECTIONS.
THE COLDEST TEMPERATURES FOR TONIGHT SHOULD COME DURING THE EVENING
HOURS...MAINLY FROM EVAPORATIONAL COOLING AS PRECIPITATION STARTS.
TEMPERATURES SHOULD GRADUALLY RISE FOR MUCH OF THE NIGHT...WITH A
RAPID WARMING INTO THE 40S LIKELY TOWARD DAYBREAK IN THE SOUTHERN TIER AS
THE SURFACE LOW REACHES LAKE ERIE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
LOW PRESSURE DEVELOPING OVER THE SOUTHERN PLAINS EARLY THIS THURSDAY
MORNING WILL BE THE MAIN WEATHER MAKER FOR OUR AREA DURING THIS
PERIOD. THE MODELS GENERALLY AGREE THAT THIS SYSTEM WILL LIFT MOVE
ACROSS THE MIDWEST TONIGHT...THEN TRACK NORTHEAST ACROSS NEW YORK
FRIDAY...REACHING THE ST LAWRENCE RIVER VALLEY LATE IN THE DAY.
WHILE THE OVERALL TRACKS OF THE SURFACE LOW ARE SIMILAR...THERE ARE
DIFFERENCES IN THE MODEL THERMAL PROFILES WHICH WILL IMPACT PCPN
TYPE...ESPECIALLY FOR AREAS EAST OF LAKE ONTARIO. THESE DIFFERENCES
SEEM TO BE RELATED TO THE FORECAST PATHS OF THE 850 MB LOWS. THE GFS
KEEPS THE 850 MB LOW A LITTLE FARTHER TO THE WEST THAN THE NAM. AS A
RESULT...THE GFS DEPICTS SLIGHTLY WARMER AIR SURGING NORTH ACROSS
THE FINGER LAKES AND NORTH COUNTRY DURING THE DAY. THIS SCENARIO
WOULD ALLOW FOR MORE OF A MIX OF SNOW AND SLEET...BEFORE A
CHANGEOVER TO ALL SNOW TAKES PLACE LATER IN THE AFTERNOON. THE
COOLER NAM SOLUTION FAVORS MORE SNOW ACROSS THIS AREA. BASED ON HOW
BOTH MODELS TRACK THE 850 LOW ACROSS WESTERN DURING DURING THE
MORNING...THE GFS SOLUTIONS SEEMS A LITTLE MORE REASONABLE.
AREAS WEST OF THE NORTH COUNTRY WILL LIKELY SEE MORE RAIN BEFORE THE
CHANGEOVER TO ALL SNOW TAKES PLACE DURING THE AFTERNOON AS COLDER
AIR WORKS IN BEHIND THE DEPARTING LOW. THE MAIN `FLY IN THE
OINTMENT` IS THAT A DEEPENING UPPER LEVEL LOW AND EMBEDDED SHORT
WAVE WILL BE CROSSING THE CWA DURING THE MORNING. DYNAMIC COOLING
ASSOCIATED WITH THE UPPER LEVEL TROUGH MAY COOL THE ATMOSPHERE
THROUGH A DEEP ENOUGH LAYER TO CAUSE A QUICKER CHANGEOVER TO ALL
SNOW. BASED ON ALL THE UNCERTAINTIES REGARDING RESULTING THERMAL
PROFILES...WE WILL HOLD OFF ON ISSUING ANY WINTER WEATHER
ADVISORIES.
THE FORECAST TRACK OF THE SURFACE LOW COULD ALSO RESULT IN RATHER
WINDY CONDITIONS ON FRIDAY...ESPECIALLY ACROSS WESTERN NEW YORK
WHERE STRENGTHENING WEST TO SOUTHWEST WINDS WILL SET UP BEHIND THE
DEPARTING LOW DURING THE LATE MORNING AND AFTERNOON.
AS COLDER AIR FILTERS INTO THE REGION FRIDAY NIGHT AND WRAP AROUND
MOISTURE DEEPENS...SYNOPTIC SNOW WILL BECOME MORE WIDESPREAD. LATER
FRIDAY NIGHT...850MB TEMPERATURES DROP TO ABOUT -11C. WITH FAIRLY
UNIFORM WEST-NORTHWEST FLOW ACROSS THE LAKES...WE SHOULD SEE A
DECENT SETUP FOR LAKE EFFECT SNOWS...PARTICULARLY ACROSS THE
SOUTHEAST SNOWBELTS. THE COLDER AIR ADVECTING INTO THE REGION WILL
ALSO ALLOW TEMPERATURES TO DROP BACK INTO SOMETHING APPROACHING
NORMAL FOR THIS TIME OF YEAR WITH LOWS IN THE 20S FRIDAY NIGHT AND
HIGHS IN THE UPPER 20S TO LOW 30S SATURDAY.
HIGH PRESSURE OVER THE MIDWEST NUDGES EAST INTO THE EASTERN GREAT
LAKES SATURDAY NIGHT...ALLOWING THE LAKE EFFECT SNOWS TO WIND DOWN.
EXPECT TEMPERATURES TO SEE A SIGNIFICANT DROP WHERE THERE IS
CLEARING...PARTICULARLY ACROSS THE NORTH COUNTRY WHERE SUB-ZERO
TEMPERATURES MAY BE POSSIBLE THANKS TO RADIATIONAL COOLING.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
SUNDAY WILL FEATURE A BREAK FROM THE ACTIVE WEATHER AS RIDGING MOVES
OVERHEAD. COLD AIR STILL IN PLACE WILL KEEP TEMPERATURES RIGHT
AROUND SEASONAL NORMS. THE RIDGING MOVES OFF TO THE EAST COAST
SUNDAY NIGHT WITH SOUTHERLY RETURN FLOW KICKING IN ACROSS THE REGION
RESULTING IN A RETURN TO MILD WEATHER FOR MONDAY WITH HIGHS CLIMBING
BACK INTO THE 40S. IN ADDITION TO THE MILD WEATHER...WE MAY SEE MORE
WET WEATHER AS A CUTTER LOW PLOWING ACROSS THE NORTHERN TIER OF THE
U.S. IS PROGGED TO CROSS THE GREAT LAKES INTO QUEBEC...POTENTIALLY
SWINGING A COLD FRONT ACROSS WESTERN NEW YORK LATE IN THE DAY MONDAY
AND BRINGING A CHANCE OF RAIN WITH A POTENTIAL FOR MORE LAKE EFFECT
SNOWS BEHIND THE FRONT ON TUESDAY.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
A FRONTAL BOUNDARY WILL CONTINUE TO EXIT TO THE EAST THROUGH THIS
MORNING. WHILE DRIER AIR WILL WORK INTO THE REGION ALOFT...QUITE A
BIT OF LOW LEVEL MOISTURE WILL LINGER INTO THIS MORNING. THIS WILL
RESULT IN SOME PATCHY IFR OR LOWER CONDITIONS. ANY SIGNIFICANT CLEARING
WILL LIKELY BE FOLLOWED BY FOG DEVELOPMENT...AND EVEN LOWER
CIGS/VSBY. THIS SHOULD IMPROVE THIS MORNING...AS DRIER AIR MIXES
DOWN.
AFTER THIS...EXPECT LARGELY VFR CONDITIONS FOR MUCH OF TODAY INTO
THIS EVENING. THEN LOWERING CIGS/VSBY AS RAIN AND SNOW MOVE IN
FROM SOUTH TO NORTH THIS EVENING.
OUTLOOK... FRIDAY...MVFR WITH RAIN AND SNOW LIKELY.
SATURDAY...VFR...WITH IFR/MVFR IN SCATTERED SNOW SHOWERS AND AREAS
OF LAKE EFFECT SNOW EAST OF THE LAKES.
SUNDAY...VFR...SCTD LAKE EFFECT SNOW SOUTHEASTERN LAKE ONTARIO.
&&
.MARINE...
EXPECT A DECENT EASTERLY FLOW TO DEVELOP AHEAD OF THE LOW LATE
TONIGHT...RESULTING IN A BRIEF PERIOD OF SMALL CRAFT CONDITIONS ON
WESTERN PORTIONS OF LAKE ONTARIO. AFTER THE LOW PASSES...SMALL CRAFT
ADVISORIES WILL LIKELY BE NEEDED ON LAKE ERIE IN A SOUTHWEST
FLOW...THOUGH THE EXACT TRACK OF THE LOW STILL IS A BIT UNCERTAIN.
THE LOW WILL MOVE INTO NEW ENGLAND ON FRIDAY NIGHT...BRINGING A
DECENT NORTHWESTER FLOW ACROSS ALL THE LAKE...WITH CONTINUED SMALL
CRAFT CONDITIONS A GOOD POSSIBILITY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 11 AM EST FRIDAY FOR LOZ042.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...TJP/WOOD
LONG TERM...TJP/WOOD
AVIATION...APFFEL
MARINE...APFFEL
AREA FORECAST DISCUSSION
NWS BUFFALO NY
429 AM EST THU FEB 23 2012
.SYNOPSIS...
HIGH PRESSURE WILL BRIEFLY RIDGE ACROSS THE REGION TODAY. LOW
PRESSURE WILL LIFT TOWARD THE EASTERN LAKES TONIGHT...INTENSIFYING
AS IT TRACKS ACROSS NEW ENGLAND FRIDAY NIGHT. THIS WILL BRING SOME
RAIN AND SNOW TO THE REGION TONIGHT INTO FRIDAY. AS THE LOW EXITS
INTO THE MARITIMES...IT WILL BRING COLDER AIR AND LINGERING SNOW
SHOWERS FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THROUGH THE EARLY MORNING HOURS...LINGERING AREAS OF SNOW WILL EXIT
EAST. SNOW SHOULD BE DONE IN MOST AREAS...WITH ALL ACCUMULATING SNOW
EXPECTED TO BE DONE BY DAYBREAK. HRRR MODEL HAS SNOW BANDS WELL
FORECAST...WITH THIS THE PREFERRED MODEL IN THE ULTRA-SHORT TERM.
AFTER THIS...WEAK SURFACE HIGH PRESSURE WILL BRIEFLY BUILD ACROSS
THE REGION. AN UPPER LEVEL DISTURBANCE EMBEDDED IN THE 500 MB FLOW
WILL PASS. WHILE IT APPEARS TO DRY FOR THIS FEATURE TO CAUSE ANY
PRECIPITATION...IT WILL LIKELY CAUSE CLOUDS TO LINGER FOR MUCH OF THE
MORNING HOURS. OTHERWISE...TEMPERATURES SHOULD CLIMB TO THE LOWER
40S IN MOST LOCATIONS...IN THE UPPER 30S ACROSS HIGHER TERRAIN AND
EAST OF LAKE ONTARIO.
THINGS GET A BIT MORE COMPLEX FOR TONIGHT AS LOW PRESSURE IS
FORECAST TO TRACK FROM THE OHIO VALLEY TOWARD THE REGION. MODEL
GUIDANCE IS IN POOR AGREEMENT FOR THIS TIMEFRAME...WITH SIGNIFICANT
MODEL DIFFERENCES IN STRENGTH AND TRACK OF THE LOW LEADING TO
DIFFERING THERMAL PROFILE FORECASTS. FOR EXAMPLE...THE LATEST RUN OF
THE EUROPEAN HAS A 998 MB LOW NEAR EASTERN OHIO ON 12Z FRIDAY
MORNING...WHILE THE NAM HAS A 985 MB LOW ACROSS LAKE ERIE. GIVEN THE
SPREAD OF SOLUTIONS...CONFIDENCE REMAINS LOWER THAN NORMAL FOR
TONIGHTS FORECAST. CLIMATOLOGICALLY SPEAKING...THE FAVORED TRACK FOR
THE SURFACE LOW WOULD BE ACROSS LAKE ERIE/ONTARIO. THIS IS BEST
REPRESENTED BY THE NAM/GFS/SREF SOLUTIONS...THOUGH THESE MODELS STILL
DIFFER ON HOW QUICKLY WARM AIR ALOFT WILL BUILD IN. FEEL THE MOST
LIKELY SOLUTION IS REFLECTED BY A NAM/GFS/SREF BLEND IN TRACK AND
TEMPERATURES ALOFT.
SO FOR TONIGHT...A BROAD AREA OF WARM AIR ADVECTION PRECIPITATION
WILL LIFT TOWARD THE REGION FROM THE SOUTH. DESPITE MODEL
DIFFERENCES...THERE IS GENERAL MODEL AGREEMENT ON THIS...WITH HIGH
CONFIDENCE IN MEASURABLE PRECIPITATION SOUTH OF LAKE ONTARIO.
PRECIPITATION WILL LIKELY START AS A MIX OF RAIN AND SNOW IN MOST
AREAS. PRECIPITATION SHOULD START DURING THE EVENING HOURS SOUTH OF
LAKE ONTARIO...AND AFTER MIDNIGHT ACROSS AND EAST OF THE LAKE...AND
TOWARD DAYBREAK WATERTOWN NORTHWARD. HERE IS WHERE THERE ARE
SIGNIFICANT MODEL DIFFERENCES...BUT DO FEEL AT LEAST A COUPLE HOURS
OF MODERATE SNOWFALL IS LIKELY IN MOST LOCATIONS. WEST OF
ROCHESTER...IT LOOKS LIKE 1 TO 3 INCHES OF SNOW BEFORE THE
CHANGEOVER TO RAIN. EAST OF ROCHESTER...IT WILL BE FURTHER FROM THE
LOW...WITH THERMAL PROFILES SUGGESTING THAT COLD AIR ALOFT WILL HANG
ON A BIT LONGER. FOR NOW...LOOKING FOR 2 TO 4 INCHES FROM ROCHESTER
EAST...INCLUDING THE NORTHERN FINGER LAKES REGIONS AND OSWEGO
COUNTY. THIS WILL BE A WET SNOW...POSSIBLY MIXED WITH SLEET AT
TIMES. QPFS SHOULD RANGE IN THE .25 TO .50 INCH RANGE THROUGH
DAYBREAK FRIDAY MORNING...LESS THAN THAN IN FAR NORTHERN SECTIONS.
THE COLDEST TEMPERATURES FOR TONIGHT SHOULD COME DURING THE EVENING
HOURS...MAINLY FROM EVAPORATIONAL COOLING AS PRECIPITATION STARTS.
TEMPERATURES SHOULD GRADUALLY RISE FOR MUCH OF THE NIGHT...WITH A
RAPID WARMING INTO THE 40S LIKELY TOWARD DAYBREAK IN THE SOUTHERN TIER AS
THE SURFACE LOW REACHES LAKE ERIE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
LOW PRESSURE DEVELOPING OVER THE SOUTHERN PLAINS EARLY THIS THURSDAY
MORNING WILL BE THE MAIN WEATHER MAKER FOR OUR AREA DURING THIS
PERIOD. THE MODELS GENERALLY AGREE THAT THIS SYSTEM WILL LIFT MOVE
ACROSS THE MIDWEST TONIGHT...THEN TRACK NORTHEAST ACROSS NEW YORK
FRIDAY...REACHING THE ST LAWRENCE RIVER VALLEY LATE IN THE DAY.
WHILE THE OVERALL TRACKS OF THE SURFACE LOW ARE SIMILAR...THERE ARE
DIFFERENCES IN THE MODEL THERMAL PROFILES WHICH WILL IMPACT PCPN
TYPE...ESPECIALLY FOR AREAS EAST OF LAKE ONTARIO. THESE DIFFERENCES
SEEM TO BE RELATED TO THE FORECAST PATHS OF THE 850 MB LOWS. THE GFS
KEEPS THE 850 MB LOW A LITTLE FARTHER TO THE WEST THAN THE NAM. AS A
RESULT...THE GFS DEPICTS SLIGHTLY WARMER AIR SURGING NORTH ACROSS
THE FINGER LAKES AND NORTH COUNTRY DURING THE DAY. THIS SCENARIO
WOULD ALLOW FOR MORE OF A MIX OF SNOW AND SLEET...BEFORE A
CHANGEOVER TO ALL SNOW TAKES PLACE LATER IN THE AFTERNOON. THE
COOLER NAM SOLUTION FAVORS MORE SNOW ACROSS THIS AREA. BASED ON HOW
BOTH MODELS TRACK THE 850 LOW ACROSS WESTERN DURING DURING THE
MORNING...THE GFS SOLUTIONS SEEMS A LITTLE MORE REASONABLE.
AREAS WEST OF THE NORTH COUNTRY WILL LIKELY SEE MORE RAIN BEFORE THE
CHANGEOVER TO ALL SNOW TAKES PLACE DURING THE AFTERNOON AS COLDER
AIR WORKS IN BEHIND THE DEPARTING LOW. THE MAIN `FLY IN THE
OINTMENT` IS THAT A DEEPENING UPPER LEVEL LOW AND EMBEDDED SHORT
WAVE WILL BE CROSSING THE CWA DURING THE MORNING. DYNAMIC COOLING
ASSOCIATED WITH THE UPPER LEVEL TROUGH MAY COOL THE ATMOSPHERE
THROUGH A DEEP ENOUGH LAYER TO CAUSE A QUICKER CHANGEOVER TO ALL
SNOW. BASED ON ALL THE UNCERTAINTIES REGARDING RESULTING THERMAL
PROFILES...WE WILL HOLD OFF ON ISSUING ANY WINTER WEATHER
ADVISORIES.
THE FORECAST TRACK OF THE SURFACE LOW COULD ALSO RESULT IN RATHER
WINDY CONDITIONS ON FRIDAY...ESPECIALLY ACROSS WESTERN NEW YORK
WHERE STRENGTHENING WEST TO SOUTHWEST WINDS WILL SET UP BEHIND THE
DEPARTING LOW DURING THE LATE MORNING AND AFTERNOON.
AS COLDER AIR FILTERS INTO THE REGION FRIDAY NIGHT AND WRAP AROUND
MOISTURE DEEPENS...SYNOPTIC SNOW WILL BECOME MORE WIDESPREAD. LATER
FRIDAY NIGHT...850MB TEMPERATURES DROP TO ABOUT -11C. WITH FAIRLY
UNIFORM WEST-NORTHWEST FLOW ACROSS THE LAKES...WE SHOULD SEE A
DECENT SETUP FOR LAKE EFFECT SNOWS...PARTICULARLY ACROSS THE
SOUTHEAST SNOWBELTS. THE COLDER AIR ADVECTING INTO THE REGION WILL
ALSO ALLOW TEMPERATURES TO DROP BACK INTO SOMETHING APPROACHING
NORMAL FOR THIS TIME OF YEAR WITH LOWS IN THE 20S FRIDAY NIGHT AND
HIGHS IN THE UPPER 20S TO LOW 30S SATURDAY.
HIGH PRESSURE OVER THE MIDWEST NUDGES EAST INTO THE EASTERN GREAT
LAKES SATURDAY NIGHT...ALLOWING THE LAKE EFFECT SNOWS TO WIND DOWN.
EXPECT TEMPERATURES TO SEE A SIGNIFICANT DROP WHERE THERE IS
CLEARING...PARTICULARLY ACROSS THE NORTH COUNTRY WHERE SUB-ZERO
TEMPERATURES MAY BE POSSIBLE THANKS TO RADIATIONAL COOLING.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
SUNDAY WILL FEATURE A BREAK FROM THE ACTIVE WEATHER AS RIDGING MOVES
OVERHEAD. COLD AIR STILL IN PLACE WILL KEEP TEMPERATURES RIGHT
AROUND SEASONAL NORMS. THE RIDGING MOVES OFF TO THE EAST COAST
SUNDAY NIGHT WITH SOUTHERLY RETURN FLOW KICKING IN ACROSS THE REGION
RESULTING IN A RETURN TO MILD WEATHER FOR MONDAY WITH HIGHS CLIMBING
BACK INTO THE 40S. IN ADDITION TO THE MILD WEATHER...WE MAY SEE MORE
WET WEATHER AS A CUTTER LOW PLOWING ACROSS THE NORTHERN TIER OF THE
U.S. IS PROGGED TO CROSS THE GREAT LAKES INTO QUEBEC...POTENTIALLY
SWINGING A COLD FRONT ACROSS WESTERN NEW YORK LATE IN THE DAY MONDAY
AND BRINGING A CHANCE OF RAIN WITH A POTENTIAL FOR MORE LAKE EFFECT
SNOWS BEHIND THE FRONT ON TUESDAY.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
A COLD FRONT STALLED ACROSS WESTERN NEW YORK ALONG THE SOUTHERN LAKE
SHORES SOUTHWEST INTO NORTHERN OH IS THE FOCUS FOR SOME LINGERING
SNOW EARLY THIS MORNING. TREND OF REGIONAL RADAR MOSAIC LOOP HAS
BACK EDGE OF SNOW MOVING ACROSS KBUF/KIAG/KJHW NEAR 06Z...FOR KROC
07Z AND KART BY 08-09Z. IFR OR LOWER CIGS MAY LINGER A BIT AFTER
THE SNOW ENDS...BUT WILL EVENTUALLY IMPROVE WITH TIME. WATER VAPOR
IMAGERY SHOWING SOME DRY AIR FILLING IN BEHIND THE BACK EDGE OF
SNOW AS UPPER SHORTWAVE PASSES EAST OF THE OH VALLEY.
DRIER AIR INFILTRATING BEHIND THE SNOW LATER THIS MORNING WILL BRING
VFR CONDITIONS BACK TO THE AREA AFTER 14Z...BUT ANOTHER SYSTEM WILL
ARRIVE FOR THURSDAY NIGHT. NAM/GFS/SREF MODELS ALL SHOW RAIN AND
LOWERING CIGS APPROACHING THE SOUTHERN TIER AND FAR WESTERN NY TOWARD
THE END OF THE TAF PERIOD.
OUTLOOK...
FRIDAY...MVFR WITH RAIN AND SNOW LIKELY.
SATURDAY...VFR...WITH IFR/MVFR IN SCATTERED SNOW SHOWERS AND AREAS
OF LAKE EFFECT SNOW EAST OF THE LAKES.
SUNDAY...VFR...SCTD LAKE EFFECT SNOW SOUTHEASTERN LAKE ONTARIO.
&&
.MARINE...
EXPECT A DECENT EASTERLY FLOW TO DEVELOP AHEAD OF THE LOW LATE
TONIGHT...RESULTING IN A BRIEF PERIOD OF SMALL CRAFT CONDITIONS ON
WESTERN PORTIONS OF LAKE ONTARIO. AFTER THE LOW PASSES...SMALL CRAFT
ADVISORIES WILL LIKELY BE NEEDED ON LAKE ERIE IN A SOUTHWEST
FLOW...THOUGH THE EXACT TRACK OF THE LOW STILL IS A BIT UNCERTAIN.
THE LOW WILL MOVE INTO NEW ENGLAND ON FRIDAY NIGHT...BRINGING A
DECENT NORTHWESTER FLOW ACROSS ALL THE LAKE...WITH CONTINUED SMALL
CRAFT CONDITIONS A GOOD POSSIBILITY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 11 AM EST FRIDAY FOR LOZ042.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...TJP/WOOD
LONG TERM...TJP/WOOD
AVIATION...APFFEL/SMITH
MARINE...APFFEL
AREA FORECAST DISCUSSION
NWS BUFFALO NY
336 AM EST THU FEB 23 2012
.SYNOPSIS...
HIGH PRESSURE WILL BRIEFLY RIDGE ACROSS THE REGION TODAY. LOW
PRESSURE WILL LIFT TOWARD THE EASTERN LAKES TONIGHT...INTENSIFYING
AS IT TRACKS ACROSS NEW ENGLAND FRIDAY NIGHT. THIS WILL BRING SOME
RAIN AND SNOW TO THE REGION TONIGHT INTO FRIDAY. AS THE LOW EXITS
INTO THE MARITIMES...IT WILL BRING COLDER AIR AND LINGERING SNOW
SHOWERS FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THROUGH THE EARLY MORNING HOURS...LINGERING AREAS OF SNOW WILL EXIT
EAST. SNOW SHOULD BE DONE IN MOST AREAS...WITH ALL ACCUMULATING SNOW
EXPECTED TO BE DONE BY DAYBREAK. HRRR MODEL HAS SNOW BANDS WELL
FORECAST...WITH THIS THE PREFERRED MODEL IN THE ULTRA-SHORT TERM.
AFTER THIS...WEAK SURFACE HIGH PRESSURE WILL BRIEFLY BUILD ACROSS
THE REGION. AN UPPER LEVEL DISTURBANCE EMBEDDED IN THE 500 MB FLOW
WILL PASS. WHILE IT APPEARS TO DRY FOR THIS FEATURE TO CAUSE ANY
PRECIPITATION...IT WILL LIKELY CAUSE CLOUDS TO LINGER FOR MUCH OF THE
MORNING HOURS. OTHERWISE...TEMPERATURES SHOULD CLIMB TO THE LOWER
40S IN MOST LOCATIONS...IN THE UPPER 30S ACROSS HIGHER TERRAIN AND
EAST OF LAKE ONTARIO.
THINGS GET A BIT MORE COMPLEX FOR TONIGHT AS LOW PRESSURE IS
FORECAST TO TRACK FROM THE OHIO VALLEY TOWARD THE REGION. MODEL
GUIDANCE IS IN POOR AGREEMENT FOR THIS TIMEFRAME...WITH SIGNIFICANT
MODEL DIFFERENCES IN STRENGTH AND TRACK OF THE LOW LEADING TO
DIFFERING THERMAL PROFILE FORECASTS. FOR EXAMPLE...THE LATEST RUN OF
THE EUROPEAN HAS A 998 MB LOW NEAR EASTERN OHIO ON 12Z FRIDAY
MORNING...WHILE THE NAM HAS A 985 MB LOW ACROSS LAKE ERIE. GIVEN THE
SPREAD OF SOLUTIONS...CONFIDENCE REMAINS LOWER THAN NORMAL FOR
TONIGHTS FORECAST. CLIMATOLOGICALLY SPEAKING...THE FAVORED TRACK FOR
THE SURFACE LOW WOULD BE ACROSS LAKE ERIE/ONTARIO. THIS IS BEST
REPRESENTED BY THE NAM/GFS/SREF SOLUTIONS...THOUGH THESE MODELS STILL
DIFFER ON HOW QUICKLY WARM AIR ALOFT WILL BUILD IN. FEEL THE MOST
LIKELY SOLUTION IS REFLECTED BY A NAM/GFS/SREF BLEND IN TRACK AND
TEMPERATURES ALOFT.
SO FOR TONIGHT...A BROAD AREA OF WARM AIR ADVECTION PRECIPITATION
WILL LIFT TOWARD THE REGION FROM THE SOUTH. DESPITE MODEL
DIFFERENCES...THERE IS GENERAL MODEL AGREEMENT ON THIS...WITH HIGH
CONFIDENCE IN MEASURABLE PRECIPITATION SOUTH OF LAKE ONTARIO.
PRECIPITATION WILL LIKELY START AS A MIX OF RAIN AND SNOW IN MOST
AREAS. PRECIPITATION SHOULD START DURING THE EVENING HOURS SOUTH OF
LAKE ONTARIO...AND AFTER MIDNIGHT ACROSS AND EAST OF THE LAKE...AND
TOWARD DAYBREAK WATERTOWN NORTHWARD. HERE IS WHERE THERE ARE
SIGNIFICANT MODEL DIFFERENCES...BUT DO FEEL AT LEAST A COUPLE HOURS
OF MODERATE SNOWFALL IS LIKELY IN MOST LOCATIONS. WEST OF
ROCHESTER...IT LOOKS LIKE 1 TO 3 INCHES OF SNOW BEFORE THE
CHANGEOVER TO RAIN. EAST OF ROCHESTER...IT WILL BE FURTHER FROM THE
LOW...WITH THERMAL PROFILES SUGGESTING THAT COLD AIR ALOFT WILL HANG
ON A BIT LONGER. FOR NOW...LOOKING FOR 2 TO 4 INCHES FROM ROCHESTER
EAST...INCLUDING THE NORTHERN FINGER LAKES REGIONS AND OSWEGO
COUNTY. THIS WILL BE A WET SNOW...POSSIBLY MIXED WITH SLEET AT
TIMES. QPFS SHOULD RANGE IN THE .25 TO .50 INCH RANGE THROUGH
DAYBREAK FRIDAY MORNING...LESS THAN THAN IN FAR NORTHERN SECTIONS.
THE COLDEST TEMPERATURES FOR TONIGHT SHOULD COME DURING THE EVENING
HOURS...MAINLY FROM EVAPORATIONAL COOLING AS PRECIPITATION STARTS.
TEMPERATURES SHOULD GRADUALLY RISE FOR MUCH OF THE NIGHT...WITH A
RAPID WARMING INTO THE 40S LIKELY TOWARD DAYBREAK IN THE SOUTHERN TIER AS
THE SURFACE LOW REACHES LAKE ERIE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
THE FORECAST SCENARIO FOR THE END OF THE WEEK AND THIS WEEKEND IS
COMING INTO SLIGHTLY BETTER FOCUS...HOWEVER DIFFERENCES IN THE TRACK
AND SPEED OF THE LARGE SURFACE LOW PROGGED TO IMPACT THE REGION
CONTINUE TO MAKE IT DIFFICULT TO NAIL DOWN THE DETAILS OF THE
FORECAST. WHAT IS CLEAR IS THAT A 500MB VORTMAX CURRENTLY OFF OF THE
PACIFIC NORTHWEST COAST WILL DIG ACROSS THE INTER-MOUNTAIN WEST INTO
THE GREAT PLAINS BEFORE EJECTING ACROSS THE GREAT LAKES...IN THE
PROCESS SPAWNING A SURFACE LOW THAT TAKES A SIMILAR TRACK. THE KEY
ISSUE IS HOW DEEP THE 500MB TROUGH DIGS INTO THE PLAINS...WHICH THEN
HAS AN IMPACT ON HOW FAR SOUTH THE SURFACE LOW FORMS...WHICH THEN
AFFECTS THE TRACK/STRENGTH OF SAID FEATURE. THE MODEL PROGS CONTINUE
TO FEATURE AN ENVELOPE OF TRACKS WITH THE NAM FEATURING THE
STRONGEST...FASTEST...MOST NORTHERLY TRACK FOR THE LOW AND THE ECMWF
THE SLOWEST...MOST SOUTHERLY...AND WEAKEST OF THE MODELS. THE GFS IS
TRENDING MORE TOWARDS THE NAM/SREF SOLUTION...TAKING A 987MB LOW
ACROSS LAKE ERIE AND THE NIAGARA PENINSULA LATE THURSDAY NIGHT AND
THE SAINT LAWRENCE VALLEY BY FRIDAY EVENING....WITH THE CMC
FEATURING A SLIGHTLY WEAKER LOW THAT TRACKS A LITTLE FARTHER
SOUTH...MORE ACROSS THE SOUTHERN TIER AND THE ADIRONDACKS. IN
ADDITION TO HAVING A SIGNIFICANT IMPACT ON THE STRENGTH OF THE WINDS
WE RECEIVE IN THE WAKE OF THE LOW...THE CMC SOLUTION WOULD ALSO KEEP
COLDER AIR OVER THE REGION FOR LONGER...RESULTING IN THE POTENTIAL
FOR MORE SIGNIFICANT SYNOPTIC SNOWFALL WITH THE LOW. THE CMC
SOLUTION IS ALSO PLAUSIBLE...AND CONSISTENT...WHICH ONLY FURTHER
PROPAGATES THE CONUNDRUM. FOR NOW WILL GO WITH A COMPROMISE BLEND OF
THE GFS AND CMC SOLUTIONS. GOING WITH THIS COMPROMISE SOLUTION...THE
SCENARIO FOR THE END OF THE WEEK AND THE WEEKEND UNFOLDS AS
FOLLOWS...
THE SURFACE LOW TRACKS TO A LOCATION APPROXIMATELY NEAR THE EASTERN
END OF LAKE ERIE THURSDAY NIGHT. ISENTROPIC UPGLIDE AHEAD OF THE LOW
WILL LEAD TO DEVELOPING PRECIPITATION FROM WEST TO EAST AND SOUTH TO
NORTH THROUGH THE NIGHT THURSDAY NIGHT. PRECIP TYPE WILL GENERALLY
BE A MIXTURE OF RAIN AND SNOW WITH ACCUMULATIONS LIMITED MAINLY TO
HIGHER TERRAIN OF THE SOUTHERN TIER AND ACROSS THE NORTH COUNTRY.
SOME AREAS IN THE NORTH COUNTRY/TUG HILL HAVE THE POTENTIAL TO SEE
AT LEAST 2 TO 4 INCHES OF WET SNOW THU NIGHT INTO FRIDAY
MORNING...WITH LOWER ACCUMULATIONS ACROSS HIGHEST ELEVATIONS OF THE
SOUTHERN TIER. EXPECT PRECIP TYPE TO CHANGE OVER TO ALL RAIN ACROSS
MUCH OF THE FORECAST AREA ON FRIDAY MORNING AS THE WARM SECTOR OF
THE LOW TRACKS ACROSS THE REGION. ONCE AGAIN...IF THE LOW TRACKS
FARTHER SOUTH...THIS COULD LIMIT THE NORTHWARD PROGRESSION OF THE
WARM AIR A LEAD TO GREATER COVERAGE/AMOUNT OF SNOWFALL THURSDAY
NIGHT INTO FRIDAY. FOR NOW...EXPECT LOWS IN THE LOW TO MID 30S...TO
UPPER 20S IN THE NORTH COUNTRY THU NIGHT WITH HIGHS IN THE UPPER 30S
TO AROUND 40 ON FRIDAY.
COLDER AIR FILTERS INTO THE REGION LATER IN THE DAY FRIDAY INTO
FRIDAY NIGHT. EXPECT PRECIP TO CHANGE BACK OVER TO SNOW BY THE END
OF THE DAY ON FRIDAY WITH A QUICK BURST OF SNOW POSSIBLE AS THE LOW
PULLS AWAY FROM THE AREA AND THE DEFORMATION BAND ONT HE BACK SIDE
OF THE LOW MOVES ACROSS THE REGION. BY LATER FRIDAY NIGHT 850MB
TEMPERATURES DROP BELOW -12C AND WITH FAIRLY UNIFORM WEST-NORTHWEST
FLOW ACROSS THE LAKES...WE SHOULD SEE A DECENT SETUP FOR LAKE EFFECT
SNOWS...PARTICULARLY ACROSS THE SOUTHEAST SNOWBELTS. SYNOPTIC
MOISTURE IS NOT LOOKING QUITE AS IMPRESSIVE AS IT HAS WITH PAST
RUNS...SO SNOWFALL ACCUMULATIONS MAY STAY SUB-ADVISORY. THE COLDER
AIR ADVECTING INTO THE REGION WILL ALSO ALLOW FOR TEMPERATURES TO
DROP BACK INTO SOMETHING APPROACHING NORMAL FOR THIS TIME OF YEAR
WITH LOWS IN THE 20S FRIDAY NIGHT AND HIGHS IN THE UPPER 20S TO LOW
30S SATURDAY.
HIGH PRESSURE OVER THE MIDWEST NUDGES EAST INTO THE EASTERN GREAT
LAKES FRIDAY NIGHT...WINDING DOWN THE LAKE EFFECT SNOWS AND BRINGING
AREAS OF CLEARING. EXPECT TEMPERATURES TO SEE A SIGNIFICANT DROP
WHERE THERE IS CLEARING...PARTICULARLY ACROSS THE NORTH COUNTRY
WHERE SUB-ZERO TEMPERATURES MAY BE POSSIBLE THANKS TO RADIATIONAL
COOLING.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
SUNDAY WILL FEATURE A BREAK FROM THE ACTIVE WEATHER AS RIDGING MOVES
OVERHEAD. COLD AIR STILL IN PLACE WILL KEEP TEMPERATURES RIGHT
AROUND SEASONAL NORMS. THE RIDGING MOVES OFF TO THE EAST COAST
SUNDAY NIGHT WITH SOUTHERLY RETURN FLOW KICKING IN ACROSS THE REGION
RESULTING IN A RETURN TO MILD WEATHER FOR MONDAY WITH HIGHS CLIMBING
BACK INTO THE 40S. IN ADDITION TO THE MILD WEATHER...WE MAY SEE MORE
WET WEATHER AS A CUTTER LOW PLOWING ACROSS THE NORTHERN TIER OF THE
U.S. IS PROGGED TO CROSS THE GREAT LAKES INTO QUEBEC...POTENTIALLY
SWINGING A COLD FRONT ACROSS WESTERN NEW YORK LATE IN THE DAY MONDAY
AND BRINGING A CHANCE OF RAIN WITH A POTENTIAL FOR MORE LAKE EFFECT
SNOWS BEHIND THE FRONT ON TUESDAY.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
A COLD FRONT STALLED ACROSS WESTERN NEW YORK ALONG THE SOUTHERN LAKE
SHORES SOUTHWEST INTO NORTHERN OH IS THE FOCUS FOR SOME LINGERING
SNOW EARLY THIS MORNING. TREND OF REGIONAL RADAR MOSAIC LOOP HAS
BACK EDGE OF SNOW MOVING ACROSS KBUF/KIAG/KJHW NEAR 06Z...FOR KROC
07Z AND KART BY 08-09Z. IFR OR LOWER CIGS MAY LINGER A BIT AFTER
THE SNOW ENDS...BUT WILL EVENTUALLY IMPROVE WITH TIME. WATER VAPOR
IMAGERY SHOWING SOME DRY AIR FILLING IN BEHIND THE BACK EDGE OF
SNOW AS UPPER SHORTWAVE PASSES EAST OF THE OH VALLEY.
DRIER AIR INFILTRATING BEHIND THE SNOW LATER THIS MORNING WILL BRING
VFR CONDITIONS BACK TO THE AREA AFTER 14Z...BUT ANOTHER SYSTEM WILL
ARRIVE FOR THURSDAY NIGHT. NAM/GFS/SREF MODELS ALL SHOW RAIN AND
LOWERING CIGS APPROACHING THE SOUTHERN TIER AND FAR WESTERN NY TOWARD
THE END OF THE TAF PERIOD.
OUTLOOK...
FRIDAY...MVFR WITH RAIN AND SNOW LIKELY.
SATURDAY...VFR...WITH IFR/MVFR IN SCATTERED SNOW SHOWERS AND AREAS
OF LAKE EFFECT SNOW EAST OF THE LAKES.
SUNDAY...VFR...SCTD LAKE EFFECT SNOW SOUTHEASTERN LAKE ONTARIO.
&&
.MARINE...
EXPECT A DECENT EASTERLY FLOW TO DEVELOP AHEAD OF THE LOW LATE
TONIGHT...RESULTING IN A BRIEF PERIOD OF SMALL CRAFT CONDITIONS ON
WESTERN PORTIONS OF LAKE ONTARIO. AFTER THE LOW PASSES...SMALL CRAFT
ADVISORIES WILL LIKELY BE NEEDED ON LAKE ERIE IN A SOUTHWEST
FLOW...THOUGH THE EXACT TRACK OF THE LOW STILL IS A BIT UNCERTAIN.
THE LOW WILL MOVE INTO NEW ENGLAND ON FRIDAY NIGHT...BRINGING A
DECENT NORTHWESTER FLOW ACROSS ALL THE LAKE...WITH CONTINUED SMALL
CRAFT CONDITIONS A GOOD POSSIBILITY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 11 AM EST FRIDAY FOR LOZ042.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...WOOD
LONG TERM...WOOD
AVIATION...APFFEL/SMITH
MARINE...APFFEL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
320 AM EST THU FEB 23 2012
.SYNOPSIS...
A WEAK DISTURBANCE WILL MOVE ACROSS THE AREA TONIGHT. A STRONG COLD
FRONT WILL PASS THROUGH THE REGION FRIDAY NIGHT. HIGH PRESSURE OVER
THE WESTERN GULF SATURDAY WILL BE CENTERED OVER THE CAROLINAS SUNDAY
AND MONDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 100 AM WED...LINE OF SHOWERS ASSOC WITH AN UPPER LEVEL
SHORTWAVE MOVING ACROSS CENTRAL NC EARLY THIS MORNING AND WILL
PUSH ACROSS THE CWA BETWEEN 0730Z AND 12Z. HRRR AND OTHER LOCAL
MESOSCALE MODELS INDICATING THIS LINE WILL WEAKEN AS MOVE ACROSS
ERN NC. BEST CHANCE OF SHOWER WILL BE N OF HIGHWAY 70 AS IT MOVES
INTO THE CWA AND THEN N OF 264 AS IT MOVES EAST OF A WASHINGTON TO
PLYMOUTH LINE WITH SRN SECTIONS SEEING LIMITED SHOWER ACTIVITY.
COULD SEE SOME MODERATE TO HEAVY SHOWERS AND WIND GUSTS TO AROUND
25-30 MPH AS THE LINE MOVES INTO NWRN SECTIONS BUT EXPECT IMPACTS
TO EASE AS THE LINE PUSHES FARTHER EAST AND WEAKENS. THE REST OF
THE FORECAST LOOKS IN GOOD SHAPE WITH MODERATE SWLY FLOW AND TEMPS
HOLDING IN THE 50S.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
AS OF 330 PM WED...WEAK DISTURBANCE WILL BE OFFSHORE BY THURS
MORNING WITH A MODERATE SOUTHWESTERLY PRESSURE GRADIENT PERSISTING
THROUGHOUT THE DAY. WINDS WILL GUST UPWARDS OF 20 MPH THROUGH LATE
AFTERNOON. FORECAST SOUNDINGS SUGGEST STRATOCU DEVELOPMENT BY
EARLY AFTERNOON BUT WITH LITTLE IMPACT ON SENSIBLE WEATHER. LOW
LEVEL THICKNESSES INCREASE AGAIN THURS WHICH COUPLED WITH STRONG
INSULATION WILL BUILD TEMPS INTO THE MID 70S ACROSS THE
REGION...SEVERAL DEGREES ABOVE CLIMO FOR LATE FEBRUARY.
&&
.LONG TERM /FRIDAY THROUGH THURSDAY/...
AN APPROACHING FRONT WILL CROSS THE AREA FRIDAY NIGHT AND MOVE
OFFSHORE SATURDAY MORNING. MODEL CONCENSUS HAS BEEN LACKING ON
BOTH THE TIMING AND OVERALL MAGNITUDE...WITH THE GFS/NAM STILL THE
FASTER/SLIGHTLY WEAKER OF THE SOLUTIONS...BRINGING THE FRONT
THROUGH FRIDAY EVENING WITH A MORE SLIT ENERGY SOLUTION. THE
UKMET/EURO SOLUTION BRINGS THE FRONT THROUGH EARLY SATURDAY WITH A
MORE PHASED SOLUTION. EITHER WAY...STRONG SOUTHERLY WINDS WILL
INCREASE FRIDAY AHEAD OF THE FRONT WITH PRECIPITATION CHANCES
INCREASING AS WE GO THROUGH THE DAY. THE GFS HAS THE PRECIP
CONFINED MAINLY TO THE SOUTH AND ALONG THE COAST...WHILE THE EURO
STILL MAINTAINS SFC/UPPER LEVEL PHASE WITH A SOLID BAND OF
PRECIPITATION MOVING THROUGH THE AREA. WITH THE TIMING OF THE
FRONT MOVING THROUGH THE AREA LATE EVENING THROUGH THE
OVERNIGHT...THIS WOULD TAP INTO THE DIURNAL PEAK OF INSTABILITY.
SB/MUCAPE HAS A RANGE FROM 100-400 J/KG DEPENDING ON THE MODEL OF
CHOICE WITH AMPLE AMOUNT OF SHEAR. ALSO...0-1KM SHEAR LOOKS BEST
JUST EAST OF 1-95 THROUGH THE AFTERNOON/EVENING WITH THE 850MB LLJ
AROUND 60 KTS..ESPECIALLY OFFSHORE. GIVEN THE LOW CAPE/HIGH SHEAR SET
UP...CAN NOT RULE OUT CONVECTION FORMATION AS THE FRONT NEARS WITH
A SLGT RISK ACROSS EASTERN NC BY SPC. IF STORMS
GENERATE...ANTICIPATE THE HIGHEST RISK TO BE ASSOCIATED WITH
STRAIGHT LINE WINDS. CONVECTION COULD BE LIMITED BY CLOUD COVER.
HOWEVER...WITH ENOUGH LIFT...ESPECIALLY NEAR 850MB...CONVECTION
COULD STILL BECOME ELEVATED. ALSO...MIGHT AS WELL MENTION THE
POSSIBILITY OF ANY BREAKS IN THE CLOUDS DURING THE DAY
FRIDAY...INCREASING TEMPS...WHICH WILL SUBSEQUENTLY INCREASE
INSTABILITY IN THE LOWEST LEVELS. GIVEN THIS...HAVE MAINTAINED ISO
THUNDER FRIDAY MORNING THROUGH FRIDAY EVENING.
PRECIPITATION WILL TAPPER OFF EARLY SATURDAY MORNING AS THE FRONT
MOVES OFFSHORE WITH WINDS VEERING TO THE NW AS THE UPPER TROUGH
SWINGING OVERHEAD THROUGH THE AFTERNOON. WITH PLENTY OF BOUNDARY
LAYER MIXING...ANTICIPATE STRONG NWLY FLOW. SKIES SHOULD SLOWLY
CLEAR AS THE MID/UPPER LEVEL LIFT MOVES OFFSHORE. EXPECT CAA TO
PUSH THROUGH THE AREA THROUGH THE WEEKEND. HIGH PRESSURE WILL MOVE
OVERHEAD SUNDAY AND MOVE OFFSHORE SUNDAY NIGHT WITH RETURN FLOW
DEVELOPING THEREAFTER.
MODELS START TO DIVERGE AT THIS POINT WITH THE GFS ILLUSTRATING A
SERIES OF SHORTWAVES TRAVERSING THE AREA FROM MONDAY THROUGH
WEDNESDAY AHEAD OF A MORE IMPRESSIVE FRONTAL SYSTEM PROGGED TO CROSS
THE AREA LATE WEDNESDAY/EARLY THURSDAY. THE 23/12Z EURO DOES NOT
SHOW THESE FEATURES AS READILY. HOWEVER...A QUICK PEAK AT THE 00Z
EURO DOES SHOW SOME SIGNATURE OF A SHORTWAVE MOVING OVERHEAD SUNDAY
NIGHT/EARLY MONDAY. WITH LITTLE LOW LEVEL MOISTURE AND LIFT...ONLY
EXPECT SOME CLOUDS TO DEVELOP SUNDAY NIGHT THROUGH EARLY MONDAY
MORNING. GIVEN MODEL DISCONTINUITY BEYOND MONDAY...WILL HIGHLIGHT
THE INCREASE CHANCE IN PRECIPITATION EARLY TUESDAY AND THROUGH THE
DAY WEDNESDAY AS SFC FEATURES CROSS THE AREA.
TEMPS WILL BE TRICKY ON FRIDAY AS THE FRONT APPROACHES. IF CLOUD
COVER LACKS THROUGH THE EARLY MORNING HOURS THIS WILL ALLOW TEMPS TO
CLIMB A BIT HIGHER THAN FORECASTED. TEMPS SHOULD INCREASE INTO THE
LOW/MID 70S FRIDAY. AS THE FRONT CROSSES...FEEL WITH CLOUD COVER
IN PLACE AND CAA JUST BEGINNING WITH PLENTY OF MIXING...TEMPS
WILL FALL INTO THE UPPER 30S/LOWER 40S. AS CLOUDS BEGIN TO CLEAR
WITH CONTINUED BOUNDARY LAYER MIXING...EXPECT TEMPS TO CLIMB INTO
THE LOWER 50S SATURDAY...WHICH IS ALSO SUPPORTED BY THE MHX
THICKNESS STUDY. WITH CLEARING AND CALMING WINDS...TEMPS WILL FALL
INTO THE LOWER 30S INLAND/LOWER 40S ALONG THE COAST SATURDAY
NIGHT. TEMPS WILL BE A TAD LOWER SUNDAY WITH LESS
MIXING...LOWERING LOW LEVEL THICKNESS AND CONTINUED CAA AS HIGH
PRESSURE MOVES OVERHEAD. TEMPS IN THE LOWER 50S. AS THE HIGH MOVES
OFFSHORE...ANTICIPATE RETURN FLOW WITH BETTER CLOUD
COVERAGE...ALLOWING TEMPS TO CLIMB BACK INTO THE 60S THROUGH THE
FIRST PART OF NEXT WEEK.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
SHORT TERM /THROUGH THURSDAY/
AS OF 100 AM THU...LINE OF SHOWERS ASSOC WITH THE UPPER LEVEL
DISTURBANCE MOVING THROUGH CENTRAL NC EARLY THIS MORNING. LEAD
TIME OF ARRIVAL PUSHES THIS LINE INTO PGV AROUND 0730Z AND ISO
AROUND 0800Z...HOWEVER HRRR SHOWING THIS LINE WEAKENING AS IT
PUSHES EAST OF THE TRIANGLE AND ESSENTIALLY DISSIPATING ALONG ITS
SRN SECTIONS WITH LITTLE IMPACT BY THE TIME IT REACHES OAJ AND
EWN. WILL CONTINUE TO INDICATE NON CONVECTIVE LLWS LATE TONIGHT
AS SW LLJ INCREASES. GUIDANCE AGAIN APPEARING TOO PESSIMISTIC WITH
CIGS DROPPING TO IFR BETWEEN 10-13Z...AND DID NOT GO WITH THIS TREND
GIVEN THE MIXED BOUNDARY LAYER PREVENTING LOW STRATUS DEVELOPMENT.
TROUGH MOVES OFFSHORE FOR THUR...AND MOSTLY SUNNY SKIES SAVE FOR
CIRRUS CAN BE EXPECTED. A FEW FAIR WEATHER CU AGAIN POSSIBLE BY
AFTERNOON AS BOUNDARY LAYER MIXES OUT TO AROUND 5 K FT. WINDS WILL
GUST UPWARDS OF 20 KT DUE TO THE EFFICIENT MIXING.
LONG TERM /FRIDAY THROUGH TUESDAY/
LOW LEVEL MOISTURE WILL INCREASE WITH SUB-VFR CONDITIONS DEVELOPING
AS PRECIPITATION MOVES INTO THE AREA FRIDAY THROUGH SATURDAY
MORNING. CONDITIONS WILL QUICKLY IMPROVE SATURDAY AS DRY AIR
INFILTRATES THE REGION. EXPECT PLEASANT FLYING CONDITIONS SUNDAY
WITH CLOUDS AGAIN INCREASING MONDAY. LOW LEVEL MOISTURE WILL
INCREASE MONDAY AFTERNOON AS ANOTHER FRONT APPROACHES THE AREA
WITH CONDITIONS DETERIORATING MONDAY NIGHT THOUGHT MUCH OF
WEDNESDAY WITH INCREASED CHANCES OF PRECIPITATION.
&&
.MARINE...
SHORT TERM /THROUGH THURSDAY/
AS OF 1030 PM WED...LATEST SURFACE AND BUOY OBSERVATIONS INDICATE
SOUTHWESTERLY WINDS INC TO 15 KNOTS OR MORE. 41036 HAS REMAINED
AROUND 5 FT...WITH FRYING PAN BUOY SE OF CAPE FEAR INCREASING TO 7
FT. 4 TO 7 FOOT SEAS OVERNIGHT INTO THUR SEEM JUSTIFIED. SOUTHWESTERLY
WINDS WILL INCREASE TO 20 TO 25 KT AFTER MIDNIGHT AHEAD OF A WEAK
UPPER LEVEL DISTURBANCE PASSING NORTH OF THE WATERS. THE STRONGEST
WINDS WILL MAINLY IMPACT THE CENTRAL AND SOUTHERN WATERS FROM
OREGON INLET SOUTH. NO CHANGES TO CURRENT SCA HEADLINES. WINDS
WILL DIMINISH TO 15 TO 20 KNOTS THURS AFTERNOON BUT SEAS WILL
REMAIN ELEVATED ESPECIALLY FOR THE OUTER FRINGES OF THE COASTAL
WATERS.
LONG TERM /FRIDAY THROUGH TUESDAY/
THE PRES GRADIENT WILL CONTINUE TO TIGHTEN FRIDAY MORNING AS A
RESULT WINDS WILL INCREASE TO AROUND 15-25KTS ACROSS ALL THE
WATERS WITH GUSTS AT OR JUST ABOVE 30KT ON FRIDAY. WINDS WILL VEER
AS THE FRONT PASSES WITH A W-NW SURGE DEVELOPING IN THE CAA
PATTERN SATURDAY. WINDS WILL CONTINUE AROUND 20-25KTS BEFORE
DECREASING AS THE SURGE WANES LATE SATURDAY. CONDITIONS IMPROVE
SAT NIGHT INTO SUNDAY MORNING WITH WINDS AND SEAS SUBSIDING AS
HIGH PRESSURE MOVES OVERHEAD. WINDS WILL INCREASE FROM THE SOUTH
MONDAY AFTERNOON THROUGH TUESDAY AS THE SFC GRADIENT TIGHTENS
AHEAD OF ANOTHER FRONT. WINDS RELAX FOR A BRIEF TIME LATE TUESDAY
THROUGH EARLY WEDNESDAY BEFORE ANOTHER SFC FEATURE APPROACHES
LATER IN THE WEEK WITH INCREASED SOUTHERLY FLOW AS A RESULT.
WAVE HEIGHTS WILL BE BUILDING TO 4-7 FT EARLY FRIDAY AS A RESULT OF
THE INCREASING SW WINDS. EXPECT SEAS TO PEAK IN THE 7-10FT RANGE
ACROSS THE OUTER WATERS...ESPECIALLY FRIDAY AFTERNOON/EVENING. SEAS
WILL SLOWLY SUBSIDE SATURDAY IN RESPONSE TO OFFSHORE WINDS FROM THE
WNW. ANTICIPATE WAVES TO BUILD IN THE BEGINNING PART OF THE WEEK IN
RESPONSE TO THE INCREASED SOUTHERLY FLOW.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST SUNDAY FOR AMZ152-154-156-
158.
&&
$$
SYNOPSIS...SK/DAG
NEAR TERM...TL
SHORT TERM...DAG
LONG TERM...LEP
AVIATION...SK/LEP
MARINE...BTC/DAG/TL/LEP
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
122 AM EST THU FEB 23 2012
.SYNOPSIS...
A WEAK DISTURBANCE WILL MOVE ACROSS THE AREA TONIGHT. A STRONG COLD
FRONT WILL PASS THROUGH THE REGION FRIDAY NIGHT. HIGH PRESSURE OVER
THE WESTERN GULF SATURDAY WILL BE CENTERED OVER THE CAROLINAS SUNDAY
AND MONDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 100 AM WED...LINE OF SHOWERS ASSOC WITH AN UPPER LEVEL
SHORTWAVE MOVING ACROSS CENTRAL NC EARLY THIS MORNING AND WILL
PUSH ACROSS THE CWA BETWEEN 0730Z AND 12Z. HRRR AND OTHER LOCAL
MESOSCALE MODELS INDICATING THIS LINE WILL WEAKEN AS MOVE ACROSS
ERN NC. BEST CHANCE OF SHOWER WILL BE N OF HIGHWAY 70 AS IT MOVES
INTO THE CWA AND THEN N OF 264 AS IT MOVES EAST OF A WASHINGTON TO
PLYMOUTH LINE WITH SRN SECTIONS SEEING LIMITED SHOWER ACTIVITY.
COULD SEE SOME MODERATE TO HEAVY SHOWERS AND WIND GUSTS TO AROUND
25-30 MPH AS THE LINE MOVES INTO NWRN SECTIONS BUT EXPECT IMPACTS
TO EASE AS THE LINE PUSHES FARTHER EAST AND WEAKENS. THE REST OF
THE FORECAST LOOKS IN GOOD SHAPE WITH MODERATE SWLY FLOW AND TEMPS
HOLDING IN THE 50S.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
AS OF 330 PM WED...WEAK DISTURBANCE WILL BE OFFSHORE BY THURS
MORNING WITH A MODREATE SOUTHWESTERLY PRESSURE GRADIENT PERSISTING
THROUGHOUT THE DAY. WINDS WILL GUST UPWARDS OF 20 MPH THROUGH LATE
AFTERNOON. FORECAST SOUNDINGS SUGGEST STRATOCU DEVELOPMENT BY
EARLY AFTERNOON BUT WITH LITTLE IMPACT ON SENSIBLE WEATHER. LOW
LEVEL THICKNESSES INCREASE AGAIN THURS WHICH COUPLED WITH STRONG
INSOLATION WILL BUILD TEMPS INTO THE MID 70S ACROSS THE
REGION...SEVERAL DEGREES ABOVE CLIMO FOR LATE FEBRUARY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
SW FLOW WILL CONTINUE TO STRENGTHEN THURSDAY NIGHT AHEAD OF A
COLD FRONT PROGGED TO CROSS THE AREA LATE FRIDAY. MODELS HAVE NOT
HANDLED THIS SYSTEM WELL WITH CONTINUITY LACKING ON TIMING AND
MAGNITUDE. THE GFS IS AMONG THE FASTER SOLUTION WHICH BRINGS THE
FRONT THROUGH FRIDAY EVENING WHERE AS THE 22/12Z EURO CONTINUES TO
BE AMONG THE SLOWER SOLUTIONS BRINGING THE FRONT THROUGH EARLY
SATURDAY MORNING. A MIDDLE OF THE ROAD SOLUTION IS FAVORED FOR NOW
GIVEN THE LARGE MODEL SPREAD WHICH BRINGS THE MAIN COLD FRONT
THRU LATER FRI EVE TO AROUND MIDNIGHT AT THE COAST.
THE TIMING OF AN EVENING COLD FROPA WILL ALLOW DIURNAL INSTABILITY
TO BE MAXIMIZED (300 J/KG SEEN VIA NAM BUFR DATA) WHEN A 50 KT LOW
LEVEL JET WILL MOVE OVER THE AREA. WITHIN THE LOW CAPE/HIGH SHEAR
ENVIRONMENT...BELIEVE THERE WILL BE A RELATIVELY SHORT OPPORTUNITY
FOR STRONGER CONVECTION TO PRODUCE GUSTY TO POSSIBLY DAMAGING
WINDS VIA WET MICROBURST DURING THE MID TO LATE AFTN HOURS ON
FRIDAY.
DRIER AND COOLER AIR WILL FILTER INTO THE AREA SATURDAY AS THE SFC
FRONT AND MID LEVEL WAVE MOVE OFF THE EASTERN SEABOARD. LOW LEVEL
THICKNESS WILL ONLY SUPPORT HIGH TEMPS IN THE LOWER TO MID 50S
THIS WEEKEND FOR MOST AREAS DESPITE PLENTIFUL SUNSHINE. WITH GOOD
RADIATIONAL COOLING CONDITIONS LOWS SAT NIGHT LIKE SUBFREEZING
OVER INLAND AREAS.
A WEAK SOUTHERN STREAM SHORT WAVE MOVING OFF THE SE COAST BRINGS
CLOUDS AND SLIGHT/LOW CHANCE PCPN CHANCES BACK INTO THE FCST ON
MONDAY. UNSETTLED WEATHER CONDITIONS MAY PERSIST TUE/WED AS A WEAK
FRONTAL BNDRY SETTLES OVER THE AREA BEFORE BEING PUSHED OFFSHORE
BY INCOMING NORTHERN STREAM SHORT WAVE LATE WED. TEMPS WILL AVERAGE
NEAR TO SLIGHTLY ABV SEASONAL NORMS DURING THE EARLY TO MID WEEK
FCST PERIOD.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
SHORT TERM /THROUGH THURSDAY/
AS OF 100 AM THU...LINE OF SHOWERS ASSOC WITH THE UPPER LEVEL
DISTURBANCE MOVING THROUGH CENTRAL NC EARLY THIS MORNING. LEAD
TIME OF ARRIVAL PUSHES THIS LINE INTO PGV AROUND 0730Z AND ISO
AROUND 0800Z...HOWEVER HRRR SHOWING THIS LINE WEAKENING AS IT
PUSHES EAST OF THE TRIANGLE AND ESSENTIALLY DISSIPATING ALONG ITS
SRN SECTIONS WITH LITTLE IMPACT BY THE TIME IT REACHES OAJ AND
EWN. WILL CONTINUE TO INDICATE NON CONVECTIVE LLWS LATE TONIGHT
AS SW LLJ INCREASES. GUIDANCE AGAIN APPEARING TOO PESSIMISTIC WITH
CIGS DROPPING TO IFR BETWEEN 10-13Z...AND DID NOT GO WITH THIS TREND
GIVEN THE MIXED BOUNDARY LAYER PREVENTING LOW STRATUS DEVELOPMENT.
TROUGH MOVES OFFSHORE FOR THUR...AND MOSTLY SUNNY SKIES SAVE FOR
CIRRUS CAN BE EXPECTED. A FEW FAIR WEATHER CU AGAIN POSSIBLE BY
AFTERNOON AS BOUNDARY LAYER MIXES OUT TO AROUND 5 K FT. WINDS WILL
GUST UPWARDS OF 20 KT DUE TO THE EFFICIENT MIXING.
LONG TERM /THURSDAY NIGHT THROUGH MONDAY/
SUB-VFR CONDITIONS EXPECTED AS PRECIPITATION MOVES INTO THE AREA
FRIDAY THROUGH SATURDAY MORNING. CONDITIONS WILL QUICKLY IMPROVE
SATURDAY AS DRY AIR INFILTRATES THE REGION. EXPECT GOOD FLYING
CONDITIONS SUNDAY WITH CLOUDS AGAIN INCREASING MONDAY. FLOW LEVEL
MOISTURE WILL INCREASE MONDAY AFTERNOON AS ANOTHER FRONT
APPROACHES THE AREA WITH CONDITIONS DETERIORATING MONDAY NIGHT
INTO TUESDAY WITH AN INCREASED CHANCE OF PRECIPITATION.
&&
.MARINE...
SHORT TERM /THROUGH THURSDAY/
AS OF 1030 PM WED...LATEST SURFACE AND BUOY OBSERVATIONS INDICATE
SOUTHWESTERLY WINDS INC TO 15 KNOTS OR MORE. 41036 HAS REMAINED
AROUND 5 FT...WITH FRYING PAN BUOY SE OF CAPE FEAR INCREASING TO 7
FT. 4 TO 7 FOOT SEAS OVERNIGHT INTO THUR SEEM JUSTIFIED. SOUTHWESTERLY
WINDS WILL INCREASE TO 20 TO 25 KT AFTER MIDNIGHT AHEAD OF A WEAK
UPPER LEVEL DISTURBANCE PASSING NORTH OF THE WATERS. THE STRONGEST
WINDS WILL MAINLY IMPACT THE CENTRAL AND SOUTHERN WATERS FROM
OREGON INLET SOUTH. NO CHANGES TO CURRENT SCA HEADLINES. WINDS
WILL DIMINISH TO 15 TO 20 KNOTS THURS AFTERNOON BUT SEAS WILL
REMAIN ELEVATED ESPECIALLY FOR THE OUTER FRINGES OF THE COASTAL
WATERS.
LONG TERM /THURSDAY NIGHT THROUGH MONDAY/
THE PRES GRADIENT WILL CONTINUE TO TIGHTEN THURSDAY EVENING AND
AS A RESULT WINDS WILL INCREASE TO AROUND 15-25KTS ACROSS ALL THE
WATERS WITH GUSTS NEAR 30KT ON FRIDAY. WINDS WILL VEER AS THE
FRONT PASSES WITH A W-NW SURGE DEVELOPING IN THE CAA PATTERN
SATURDAY. WINDS WILL CONTINUE AROUND 20-25KTS BEFORE DECREASING
AS THE SURGE WANES LATE SATURDAY. CONDITIONS IMPROVE SAT NIGHT
INTO SUNDAY MORNING WITH WINDS AND SEAS SUBSIDING. WINDS WILL
INCREASE FROM THE SOUTH MONDAY AFTERNOON THROUGH TUESDAY AS THE
SFC GRADIENT TIGHTENS AHEAD OF ANOTHER COLD FRONT.
WAVE HEIGHTS WILL BE BUILDING TO 4-7 FT LATE THURSDAY NIGHT INTO
EARLY FRIDAY AS A RESULT OF THE INCREASING SW WINDS. EXPECT SEAS
TO PEAK IN THE 7-10FT RANGE ACROSS THE OUTER WATERS...ESPECIALLY
FRIDAY AFTERNOON/EVENING. SEAS WILL SLOWLY SUBSIDE SATURDAY IN
RESPONSE TO OFFSHORE WINDS FROM THE WNW.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST SUNDAY FOR AMZ152-154-156-
158.
&&
$$
SYNOPSIS...SK/DAG
NEAR TERM...SK
SHORT TERM...DAG
LONG TERM...BTC/LEP
AVIATION...BTC/SK
MARINE...BTC/DAG/TL
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
124 AM EST THU FEB 23 2012
.SYNOPSIS...
A WEAK COLD FRONT CROSSES TONIGHT AND ANOTHER WARM FRONT THURSDAY. A
STRONG COLD FRONT CROSSES THURSDAY NIGHT. FALLING TEMPERATURES
FRIDAY. LIGHT SNOW SHOWERS FRIDAY NIGHT INTO SATURDAY.
&&
.NEAR TERM /THROUGH TODAY/...
1230 AM UPDATE...
RAISED POPS TO LIKELY ACROSS THE MIDDLE PORTION OF THE AREA WITH S/W
TROF MOVING ACROSS THE OHIO VALLEY OVERNIGHT. ALSO...WARM FRONT
SETS UP OVER SOUTHERN PORTION OF AREA THU MORNING AND TAKES MUCH OF
THE DAY TO MOVE N. INCREASED POPS THU TO REFLECT SHRA/TSRA N OF THE
FRONT.
10PM UPDATE...
SHOULD GET A BREAK FROM THE SHOWERS...BUT IR SATELLITE IMAGERY
SHOWING THE NEXT WAVE EMBEDDED IN THE BROAD CYCLONIC FLOW ALOFT
NOW PUSHING THROUGH SOUTHERN ILLINOIS AND INDIANA. ARRIVAL TIME TO
THE TRI STATE AREA LOOKING TO BE 07Z OR SO BASED ON THE HRRR WHICH
HAS A HOLD OF THIS FEATURE. HAVE BUMPED UP THE POPS IN THIS TIME
FRAME TO REFLECT THIS VORT MAX MOVING THROUGH.
PREVIOUS DISCUSSION...
CURRENT RADAR SHOWS SOME RETURNS ACROSS THE COAL FIELDS IN
ASSOCIATION WITH AN UPPER LEVEL SHORTWAVE TROUGH AND WEAK SURFACE
BOUNDARY...HOWEVER DEW POINT DEPRESSIONS ARE STILL PRETTY LARGE AND
HAVE NOT HAD ANY REPORTS OR PRECIP HITTING THE GROUND YET IN OUR CWA.
AS THE COLUMN SATURATES...SHOWERS ARE POSSIBLE THIS EVENING ACROSS
THE COAL FIELDS...EXTENDING NE INTO THE MOUNTAINS OVERNIGHT. HAS
NOT BEEN MUCH LIGHTNING ACTIVITY WITH THIS SINCE EARLIER THIS
MORNING...BUT HAVE LEFT MENTION OF THUNDER THROUGH EARLY EVENING
ACROSS SOUTHERN COAL FIELDS. CONVECTIVE SHOWERS...EVEN WITHOUT
THUNDER...COULD STILL ENHANCE TODAYS GUSTY WINDS AND PRODUCE
LOCALIZED GUSTS UP OF 40 TO 50 MPH.
AS A WARM FRONT PASSES THROUGH ANOTHER ROUND OF WARM AIR
ADVECTION SETS IN TOMORROW...SO WILL SEE A MILD TO WARM DAY ACROSS
THE REGION. THE LOWLANDS SHOULD WARM INTO THE UPPER 50S AND
60S...WITH THE MOUNTAINS TOPPING OUT IN THE LOWER 50S. A STRONG
COLD FRONT WILL BE APPROACHING FROM THE WEST ON THURSDAY...SO
COULD SEE SOME SHOWERS MOVING INTO SE OHIO BY LATE AFTERNOON AHEAD
OF THE COLD FRONT. TIME OF DAY IS NOT REAL CONDUCIVE TO
THUNDER...BUT COULD GET A RUMBLE OR TWO BEFORE EARLY EVENING AND
LOSS OF DIURNAL HEATING.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
COLD FRONT...FROM LOW PRESSURE THAT WILL MOVE ACROSS THE SOUTHERN
GREAT LAKES AND INTO THE ST. LAWRENCE RIVER VALLEY THURSDAY
NIGHT...WILL MOVE ACROSS THE CWA AND THROUGH THE REGION BY FRIDAY
MORNING. SHOWERS AND POSSIBLY A RUMBLE EARLY WILL MOVE THROUGH
WITH THE FRONT. MUCH COLDER AIR MOVES IN BEHIND THE FRONT ON
FRIDAY WITH 85H TEMPS DIPPING TO -8 TO -10 ON GOOD NORTHWEST FLOW.
SHOWERS WILL CONTINUE INTO SATURDAY AS UPPER TROUGH AND UPPER
LEVEL DISTURBANCES MOVE THROUGH THE REGION. AIR WILL BE COLD
ENOUGH THAT ANY SHOWERS WILL QUICKLY MIX OR CHANGE OVER TO LIGHT
SNOW AND COULD SEE SOME LIGHT ACCUMULATIONS ACROSS THE HIGHER
TERRAIN...ESPECIALLY IN THE UPSLOPE AREAS OF THE NORTHERN MOUNTAINS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
PERIOD GENERALLY DEFINED BY EXITING POSITIVELY TILTED SHORTWAVE
TROUGH TO THE NORTH OF AREA SAT EVENING WITH RIDGING BUILDING INTO
REGION FOR SUNDAY...FOLLOWED BY UPPER LEVEL CUTOFF LOW TO NORTHWEST
WITH ASSOCIATED SOUTHWEST FLOW ALOFT AHEAD OF IT ACROSS EASTERN
CONUS FOR MON-WED TIME FRAME.
SAT NIGHT LARGE SCALE SUBSIDENCE OVERSPREADS FORECAST AREA AS
AFOREMENTIONED SHORTWAVE TROUGH AXIS PROGRESSES ACROSS REGION. DEPTH
OF LOW LEVEL MOISTURE TRAPPED WITH SFC FLOW OFF GREAT LAKES SHOULD
BE SUFFICIENTLY DEEP TO KEEP SOME -SN GOING IN PREFERRED UPSLOPE
LOCATIONS. LIGHT SNOW WILL COME TO AN END BY EARLY SUNDAY MORNING
WITH RAPIDLY CLEARING SKIES AND SEASONAL AFTERNOON TEMPS AS UPPER
LEVEL RIDGING BUILDS INTO THE AREA. FLOW ALOFT RAPIDLY TURNS
SOUTHWEST FROM MON-WED HOWEVER AS UPPER LEVEL LOW PROGRESSES ACROSS
THE NORTH CENTRAL CONUS. THIS FEATURE ALONG WITH ASSOCIATED COLD
FRONT/MOISTURE FIELDS ARE WHERE LONG RANGE BEGIN TO DIVERGE. MUCH OF
THE LONG RANGE GUIDANCE LEANS TOWARDS A SLOWER SOLUTION...WHILE THE
GFS IS MUCH MORE PROGRESSIVE. GEFS LOOSELY SUPPORTS THE SLOWER
SOLUTION AS WELL AND THUS HAVE LEANED THE FORECAST IN THIS
DIRECTION.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
MAINLY VFR CONDITIONS TO START OUT DESPITE SHRA/TSRA MOVING ACROSS
SOUTHERN PORTIONS OF THE AREA AND IN THE MOUNTAINS EARLIER IN THE
NT. PATCHY MVFR FOG IS POSSIBLE ANY TIME OVERNIGHT IN THESE
AREAS...AND MVFR STRATOCU MAY FORM IN THE MOUNTAINS.
A WARM FRONT WILL TRIGGER AREAS OF SHOWERS AND THUNDERSTORMS AS IT
SETS UP ACROSS E KY AND SRN WV THU MORNING...AND THEN MOVE N ACROSS
THE AREA DURING THE DAY. THE FIRST SUCH BATCH MOVING THROUGH THE
MIDDLE OHIO VALLEY TO START THE PERIOD MOVES E ACROSS CENTRAL WV
OVERNIGHT. THIS COULD BRING MVFR CONDITIONS. A SECOND BATCH WILL
LIKELY COME THROUGH THE MIDDLE OHIO VALLEY THU MORNING BUT THIS
BATCH IS LIKELY TO MOVE NE...AFFECTING NORTHERN WV...THU AFTERNOON.
FINALLY...ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS ARE POSSIBLE AS
A COLD FRONT APPROACHES THE AREA FROM THE W. ANY OF THE SHOWERS AND
THUNDERSTORMS CAN BRING MVFR OR WORSE CONDITIONS...ALONG WITH STRONG
WIND GUSTS.
LIGHT SW SFC FLOW INTO THU MORNING WILL TURN SE N OF THE WARM FRONT
THU AND STRENGTHEN FROM THE SW S OF THE FRONT. WINDS WILL SWITCH TO
SW AND STRENGTHEN LATER THU FARTHER N...AS THE WARM FRONT MOVES N.
MODERATE FLOW ALOFT OVERNIGHT WILL BECOME STRONG S THU. STRONG SW
FLOW SFC AND ALOFT SHOULD DOMINATE EVERYWHERE BY 06Z FRI.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z FRIDAY...
FORECAST CONFIDENCE: LOW TO MEDIUM.
ALTERNATE SCENARIOS: THIS IS A PATTERN MORE AKIN TO SPRING AND EARLY
SUMMER THAN WINTER...WITH A HIGH DEGREE OF UNCERTAINTY AS TO WHERE
AREAS OF SHOWERS AND THUNDERSTORMS WILL BE...ESPECIALLY BEYOND 6
HRS. EVEN THE WIND PATTERN IS A BIT COMPLEX AS A WARM FRONT
DEVELOPS OVER AND THEN MOVES N ACROSS THE AREA...AND THUNDERSTORMS
PRODUCE STRONG WIND GUSTS FROM VARIOUS DIRECTIONS BUT MOST LIKELY
MORE W THAN THE GENERAL FLOW.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE THU 02/23/12
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12
CRW CONSISTENCY M M H M H H L L L H M M
HTS CONSISTENCY H H H H H H M M L H H H
BKW CONSISTENCY M M H M M L M M M H M H
EKN CONSISTENCY M M M M M M M H H M M M
PKB CONSISTENCY H H M H M M H M M M M H
CKB CONSISTENCY M H H M H H H H M M M H
AFTER 06Z FRIDAY...
IFR POSSIBLE IN LINGERING RAIN SHOWERS OR THUNDERSTORMS AND LOW
CLOUDS LATE THU NT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JS/ARJ/MZ/GG
NEAR TERM...ARJ/TRM/MZ/26
SHORT TERM...JS
LONG TERM...GG
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
316 AM EST THU FEB 23 2012
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BUILD OVER THE AREA TODAY. A COLD FRONT IS
EXPECTED TO SWEEP ACROSS THE CAROLINAS EARLY FRIDAY. HIGH PRESSURE
WILL THEN RETURN OVER THE WEEKEND AND LINGER INTO EARLY NEXT WEEK.
ANOTHER COLD FRONT WILL APPROACH THE REGION FROM THE WEST NEXT
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
A LINE OF CONVECTION SHOULD MOVE TO THE EAST OF THE FCST AREA BY
08Z...THEREAFTER WE WILL ONLY HAVE TO DEAL WITH A FEW STRAGGLERS
DEVELOPING IN A WEAKLY FORCED ENVIRONMENT AHEAD OF A TRAILING SHORT
WAVE. THESE SCATTERED SHOWERS SHOULD ALSO WORK THEIR WAY EAST AND BE
OUT OF THE AREA BY SUNRISE. IN THE MEAN TIME...PATCHES OF FOG AND
LOW STRATUS WILL DEVELOP IN THE RAIN COOLED AIR THROUGH DAYBREAK.
TEMPS SHOULD REMAIN MILD.
FOR TODAY...THE MAIN STORY WILL BE THE WARM TEMPS. THE NEARLY ZONAL
FLOW ALOFT WILL BUCKLE WITH HEIGHTS RISING DURING THE DAY AS A RIDGE
BUILDS OFF THE E COAST. NOT ONLY WILL WE GET A HEAD START WITH THE
MILD OVERNIGHT LOWS...BUT WARM ADVECTION WILL CONTINUE THROUGH THE
DAY WITH SW WINDS AT 850MB. HIGH TEMPS WERE NUDGED TOWARD THE BIAS
CORRECTED GUIDANCE WHICH ACTUALLY RESULTED IN A CUT OF A DEGREE OR
TWO OFF THE PREVIOUS FCST...BUT IT SHOULD STILL BE MUCH ABOVE NORMAL
AT ANY RATE. FORCING WILL BE MINIMAL AS WE WILL BE IN BETWEEN UPPER
SYSTEMS...SO EXPECT A DRY DAY.
FOR TONIGHT...THE NEXT UPPER SYSTEM WILL MOVE EASTWARD OVER THE
MIDWEST...WHICH WILL PUSH A COLD FRONT TOWARD THE FCST AREA AFTER
MIDNIGHT. THE FRONT IS EXPECTED TO REACH THE MTNS BY DAYBREAK FRIDAY
WITH A WEAKENING BAND OF CONVECTIVE PRECIP. WILL ALLOW THE PRECIP
CHANCES TO CLIMB TO THE LIKELY RANGE ON THE TN BORDER IN THE LATE
EVENING...WITH THE THINKING THAT CONVECTION THAT DEVELOPS EARLIER IN
THE EVENING OVER TN WILL REACH WRN NC BEFORE FALLING APART. E OF THE
MTNS...THE PRECIP CHANCES WILL BE HELD IN CHECK BY DOWNSLOPE...SO
THE POP WAS LIMITED TO CHANCE OVER THE FOOTHILLS AND WRN UPSTATE...
AND SLIGHT CHANCE OVER THE WRN PIEDMONT. MIN TEMPS WILL ONCE AGAIN
BE RELATIVELY MILD FOR THIS TIME OF YEAR.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 230 AM THURSDAY...MODEL DIFFERENCES WITH RESPECT TO THE TIMING
OF THE EASTWARD PROGRESSION OF FRONTAL ZONE PCPN ON FRIDAY CONTINUE
WITH THE 00 UTC ECMWF REMAINING THE SLOW SOLUTION VERSUS BOTH THE
OP NAM/GFS. POPS WILL CONTINUE TO BE ORIENTED CLOSE TO THE LATEST
SREF...WITH ANY LINGERING/CONTINUED DEEP CONVECTION BECOMING LIMITED
TO JUST THE PIEDMONT BY AFTERNOON. BASED ON THE LIKELIHOOD THAT AS
PRIMARY LLJ/RICHER BLYR MOISTURE TRANSLATES TO THE EASTERN
CAROLINAS AS THE DAY WEARS ON...CHANCES FOR TSTMS TO PRODUCE
DAMAGING WIND GUSTS WILL BE BETTER EAST OF THE CWFA. AS LONG AS
INSOLATION IS NOT LIMITED A GREAT DEAL FROM LINGERING DEEPER
CONVECTION...THE PIEDMONT COULD SQUEAK OUT ONE MORE 70 DEG F DAY.
SAVE FOR THE POSSIBILITY OF NW NC SNOW SHOWERS...DEEP LAYERED DRYING
WILL OVERSPREAD THE REGION FRIDAY NIGHT...AND MIN TEMPS SATURDAY
MORNING COULD BE MORE THAN 20 DEG F COLDER THAN FRIDAY MORNING.
WITHIN THE LINGERING CYCLONIC FLOW ALOFT...DEEP LAYER DRY AIR
CONTINUES THRU SATURDAY AS LLVL RIDGING BUILDS EASTWARD. CHILLIER
AIR ACRS THE MTNS WILL BE SLOWER TO DISPLACE...BUT FTHL/PIEDMONT
MAX TEMPS SHOULD BE CLOSE TO CLIMO.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 200 AM THURSDAY...THE MEDIUM RANGE MODELS ARE IN FAIRLY GOOD
AGREEMENT WITH BROAD SURFACE HIGH OVER THE EASTERN CONUS WILL BRING
MOSTLY DRY WEATHER AND SEASONABLY COOL TEMPERATURES TO MUCH OF THE
REGION ON SUNDAY. AS THE HIGH MOVES OUT INTO THE ATLANTIC MONDAY...
AN UPPER LVL DISTURBANCE OVER THE GULF WILL LIFT NORTH ACROSS OUR
AREA. THE ECMWF IS MUCH WETTER THAN THE GFS BRINGING PRECIP AMOUNTS
UP TO 0.25 INCHES INTO MUCH OF THE REGION. THE GFS HAS LIGHT PRECIP
DEVELOPING OVER MAINLY SOUTHERN HALF OF OUR FORECAST AREA IN
RESPONSE TO A WEAK HIGH PRESSURE DOMINATING OVER THE NORTH. I USED
MODEL BLEND KEEPING AT LEAST SLIGHT CHANCE POPS IN THE GRIDS MONDAY.
AN UPPER RIDGE WILL BUILD OVER THE REGION FOR MOSTLY DRY WEATHER AND
MILDER TEMPERATURES ON TUESDAY. A STRONG COLD FRONT WILL
APPROACH THE CAROLINAS FROM THE WEST RESULTING IN UNSETTLED WEATHER
ACROSS OUR REGION ON WEDNESDAY. MODELS SHOW DECENT CAPE VALUES WILL
BE OVER THE SOUTHERN PORTIONS OF OUR CWA DURING THE PASSAGE OF THE
SYSTEM. HENCE...A CHANCE OF THUNDERSTORMS WAS MENTIONED MAINLY SOUTH
OF THE REGION ON WEDNESDAY. TEMPERATURES WILL STAY NEAR OR A LITTLE
ABOVE NORMALS THROUGH THE PERIOD.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
AT KCLT AND ELSEWHERE...IMMEDIATE CONCERN IS LINE OF CONVECTION MOVG
ACROSS THE WESTERN CAROLINAS THIS EVENING...BUT THAT SHOULD BE GONE
BY 07Z WITH ONLY A FEW SHOWERS LEFT OVER THE HIGHER TERRAIN THROUGH
THE PRE-DAWN HOURS. WITH THAT OUT OF THE WAY...THE MAIN CONCERN
BECOMES THE MODEL FCST OF WIDESPREAD IFR STRATUS THROUGH SUNRISE.
STILL NOT CONVINCED THE LAMP AND NAM ARE ON THE RIGHT TRACK WITH
THIS. SATELLITE IMAGERY SHOWS PATCHES OF LOWER CLOUDS OVER N GA AND
NE AL IN THE WAKE OF THE CONVECTION...BUT THE WORST OF IT IS BARELY
MVFR. THINK THE RUC MIGHT HAVE THE BETTER HANDLE ON PATCHY MVFR
CEILINGS AND WILL STEER THE TAFS IN THAT DIRECTION. THE CLOUDS WILL
SCATTER OUT DURING THE 13Z TO 15Z TIME FRAME...AFTER WHICH THE
BALANCE OF THE DAY WILL BE VFR WITH A SW WIND. THE NEXT UPPER SYSTEM
SHOULD NOT ARRIVE UNTIL AFTER THE END OF THE TAF PERIOD.
OUTLOOK...LOW PRESSURE WILL DEVELOP OVER THE DEEP SOUTH THU NIGHT
AND FRI. WIDESPREAD LOW CIGS AND PCPN ARE EXPECTED AS THE LOW
DEVELOPS. DRIER AND COLDER WEATHER WILL FOLLOW FOR THE WEEKEND.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...PM
SHORT TERM...CSH
LONG TERM...JOH
AVIATION...PM
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1245 AM EST THU FEB 23 2012
.SYNOPSIS...
WEAK HIGH PRESSURE WILL LINGER OVER THE AREA THROUGH THURSDAY. A
STRONG COLD FRONT IS EXPECTED TO MOVE OVER THE CAROLINAS EARLY
FRIDAY. HIGH PRESSURE WILL THEN RETURN OVER THE WEEKEND AND LINGER
INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
A LINE OF CONVECTION WILL CONTINUE TO WORK ITS WAY ACROSS THE
EASTERN ZONES DURING THE EARLY MORNING HOURS...AND SHOULD BE EAST OF
THE FCST AREA BY 07Z. ONLY SCATTERED SHRA TO DEAL WITH...MAINLY OVER
THE HIGHER TERRAIN...FOR THE PREDAWN HOURS...AND THAT SHOULD END
BEFORE SUNRISE. HAVE RAISED THE PRECIP CHANCES ACCORDINGLY OVER THE
EAST AND LOWERED THEM OUT WEST TO MATCH RADAR TRENDS.
PREVIOUS DISCUSSION...STRONGER SHORT WAVE MOVES THRU THE BOTTOM OF A
BROAD LONG WAVE TROF AND ACROSS THE AREA THIS EVENING. THIS SHOULD
HELP ADDITIONAL CONVECTION DEVELOP THIS EVENING AND MOVE IT ACROSS
THE CWFA. ACTIVITY SHUD BEGIN OVER THE NC MTNS AND NE GA AND MOVE
EAST ACROSS THE CWFA. DEW POINTS SHUD CONTINUE TO INCREASE AHEAD OF
THE WAVE IN THE STRONG SWLY FLOW. THIS WILL LEAD TO WEAK INSTABILITY
ACROSS THE AREA THIS EVENING AS THE WAVE MOVES THRU. SHEAR STILL
EXPECTED TO BE QUITE STRONG AS A LOW LEVEL JET DEVELOPS. LARGE
HELICITY VALUES WITH STRONG TURNING PROFILE ALSO EXPECTED. STILL
APPEARS TO BE A THREAT OF SEVERE STORMS PRODUCING DAMAGING WINDS OR
EVEN A TORNADO IF THE WEAK INSTABILITY CAN BE REALIZED. MULTICELLS
OR EVEN MINI-SUPERCELLS WILL BE POSSIBLE. THE CONVECTION SHUD SWEEP
EAST OF THE AREA AFTER MIDNIGHT WITH SOME LINGERING MTN SHRA ENDING
BY DAYBREAK. EXPECT AREAS OF FOG AND LOW CLOUDS TO DEVELOP AGAIN
TOWARD MORNING IN THE LINGERING LOW LEVEL MOISTURE. LOWS WILL BE AS
MUCH AS 15 DEGREES ABOVE NORMAL.
CLEARING SKIES AND VERY WARM CONDITIONS EXPECTED THU AS HEIGHTS RISE
IN DEVELOPING ZONAL FLOW. EXPECT THE LOW CLOUDS AND FOG TO DISSIPATE
A LITTLE MORE QUICKLY THU MORNING AS FLOW WILL BE A LITTLE MORE WLY
AND DRIER AIR MOVES IN. SHUD BE ANOTHER BREEZY DAY BUT WIND GUSTS
NOT QUITE AS STRONG. HIGHS WILL BE 15 TO 20 DEGREES ABOVE NORMAL IN
THE WLY FLOW AND RISING THICKNESSES.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
AS OF 200 PM WEDNESDAY...A WEAKLY FORCED FRONTAL BOUNDARY IS
FORECAST TO MOVE ACROSS THE MOUNTAINS AND INTO THE PIEDMONT BY 12Z
FRI WELL AHEAD OF THE MAIN UPPER TROUGH TO ITS WEST. THE QUESTION IS
WHAT THE COVERAGE OF CONVECTION WILL BE THU NIGHT ALONG AND AHEAD OF
THE FRONTAL BOUNDARY? CURRENT INDICATIONS FROM MODEL GUIDANCE IS THAT
A BROKEN LINE OF CONVECTION WILL REACH THE MOUNTAINS SOMETIME AFTER
MIDNIGHT...BUT TEND TO DECREASE IN COVERAGE AS IT MOVES OFF THE
MOUNTAINS EARLY FRIDAY MORNING DUE TO DEEP SW-W WIND FLOW WITH
LITTLE APPARENT BACKING OF THE WIND FIELD IN THE LOWER LEVELS. WIND
SPEEDS/SHEAR WILL BE IMPRESSIVE THU NIGHT WITH 850MB WINDS 50+ KTS.
HELICITY VALUES WILL ALSO BE QUITE HIGH. HOWEVER...LOOKING AT THE
MODEL SOUNDINGS...A MID LEVEL CAPPING INVERSION IS APPARENT. THE
BOTTOM LINE IS THAT IT LOOKS LIKE IT WILL BE DIFFICULT TO GET DEEP
CONVECTION TO DEVELOP OVER A LARGE AREA THU NIGHT...SO WILL SHOW
LIKELY TYPE COVERAGE ENTERING THE MOUNTAINS...BUT DIMINISHING INTO
THE SCATTERED RANGE AS THE FRONT MOVES OFF THE MOUNTAINS. THE SEVERE
THREAT IS CERTAINLY NON ZER0...BUT IT APPEARS ANY SEVERE CONVECTION
SHOULD BE ISOLATED.
THE FORECAST DOES NOT GET ANY EASIER FOR FRI AS THE FRONTAL BOUNDARY
WILL BE SLOW TO EXIT THE AREA AS IT AWAITS A PUSH FROM THE UPPER
TROUGH APPROACHING FROM THE WEST. THE 12Z MODEL SUITE CONTINUES TO VARY
CONSIDERABLY IN REGARD TO HOW FAST THE FRONT WILL MOVE AWAY FROM THE
AREA AND ALSO HOW MUCH PRECIP WILL FALL ALONG THE BOUNDARY. THE
NAM/ECM/GEM ARE SLOWER/WETTER THAN THE FASTER/DRIER GFS. THE SREF
AGAIN APPEARS TO BE A GOOD COMPROMISE WHICH WILL KEEP POPS OVER THE
AREA OUTSIDE OF MOUNTAINS WITH THE HIGHEST POPS OVER SOUTHERN AREAS.
THE FRONT SHOULD FINALLY PUSH TO THE EAST OF THE AREA FRI NIGHT. THE
UPPER TROUGH AXIS IS FORECAST TO ROTATE THROUGH LATE FRI NIGHT INTO
SAT. LOOKS LIKE AT LEAST SOME SCATTERED SNOW SHOWERS WILL BE THE
RESULT IN THE TN BORDER COUNTIES...ESPECIALLY IN THE NORTHERN
MOUNTAINS. OTHERWISE..,.SAT LOOKS TO BE GENERALLY SUNNY ELSEWHERE WITH
TEMPS ABOUT CATEGORY BENEATH SEASONAL LEVELS EVEN WITH DOWNSLOPE
FLOW. USED A MOS BLEND FOR TEMPS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 215 PM WEDNESDAY...THE FIRST PORTION OF THE MEDIUM RANGE LOOKS
RATHER STRAIGHT FORWARD AS ALL GUIDANCE SOURCES AGREE THAT SURFACE
HIGH PRESSURE WILL BE IN CONTROL OF OUR WEATEHR REGIME ALL OF
SUNDAY AND MOST IF NOT ALL OF THE DAY ON MONDAY. HOWEVER...
DISCREPANCIES IN THE MODEL GUIDANCE QUICKLY DEVELOP BY LATE MON AS
MODELS BECOME OUT OF PHASE WITH UPPER FEATURES. ECM/GEM ARE MUCH
QUICKER THAN THE GFS WITH THE NEXT UPPER TROUGH AND SUBSEQUENT GULF
MOISTURE RETURN LATE MONDAY INTO MONDAY NIGHT. HPC USED A ECM
ENSEMBLE MEAN FOR THE TUE/WED TIME PERIOD WHICH SUPPORTS AN INITIAL
FRONTAL PASSAGE EARLY TUE...WITH A WAVE DEVELOPING ON THE FRONT AND
THEN MOVING AWAY FROM THE AREA ON WED. HENCE...THE FORECAST WILL BE
DRY SUN AND MON MOST AREAS....WITH UNSETTLED WEATHER RETURNING MON
NIGHT...FEATURING CHANCES OF RAIN INTO EARLY WED. DRYER AIR/CLEARING IS
SHOWN OVERSPREADING THE AREA BY LATE WED. STAYED CLOSE TO HPC
GUIDANCE FIELDS WHICH HAS MAX TEMPS NEAR OR A LITTLE BELOW
AVERAGE.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AT KCLT AND ELSEWHERE...IMMEDIATE CONCERN IS LINE OF CONVECTION MOVG
ACROSS THE WESTERN CAROLINAS THIS EVENING...BUT THAT SHOULD BE GONE
BY 07Z WITH ONLY A FEW SHOWERS LEFT OVER THE HIGHER TERRAIN THROUGH
THE PRE-DAWN HOURS. WITH THAT OUT OF THE WAY...THE MAIN CONCERN
BECOMES THE MODEL FCST OF WIDESPREAD IFR STRATUS THROUGH SUNRISE.
STILL NOT CONVINCED THE LAMP AND NAM ARE ON THE RIGHT TRACK WITH
THIS. SATELLITE IMAGERY SHOWS PATCHES OF LOWER CLOUDS OVER N GA AND
NE AL IN THE WAKE OF THE CONVECTION...BUT THE WORST OF IT IS BARELY
MVFR. THINK THE RUC MIGHT HAVE THE BETTER HANDLE ON PATCHY MVFR
CEILINGS AND WILL STEER THE TAFS IN THAT DIRECTION. THE CLOUDS WILL
SCATTER OUT DURING THE 13Z TO 15Z TIME FRAME...AFTER WHICH THE
BALANCE OF THE DAY WILL BE VFR WITH A SW WIND. THE NEXT UPPER SYSTEM
SHOULD NOT ARRIVE UNTIL AFTER THE END OF THE TAF PERIOD.
OUTLOOK...LOW PRESSURE WILL DEVELOP OVER THE DEEP SOUTH THU NIGHT
AND FRI. WIDESPREAD LOW CIGS AND PCPN ARE EXPECTED AS THE LOW
DEVELOPS. DRIER AND COLDER WEATHER WILL FOLLOW FOR THE WEEKEND.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...PM/RB/RWH
SHORT TERM...LG
LONG TERM...LG
AVIATION...PM
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
1121 PM CST WED FEB 22 2012
.DISCUSSION...SEE AVIATION SECTION BELOW.
&&
.AVIATION...CONDITIONS ARE DETERIORATING ACROSS THE EASTERN
PORTIONS OF THE AREA...ESPECIALLY CLOSER TO THE COAST WHERE SEA
FOG IS ADVECTING INLAND. IFR/LIFR CONDITIONS ARE EXPECTED TO
PREVAIL THROUGH MUCH OF THE OVERNIGHT HOURS WITH IMPROVING
CONDITIONS BY MID MORNING ON THURSDAY. THERE IS THE POTENTIAL FOR
FOG THU NIGHT CLOSER TO 06Z WHICH IS THE TAIL END OF THE TAF
PERIOD THEREFORE WILL NOT MENTION IN TAF AT THIS TIME. BEYOND THE
TAF PERIOD...A STRONG COLD FRONT IS EXPECTED TO MOVE THROUGH S TX
BTWN 06Z AND 12Z FRI MORNING. AREAS TO THE WEST ACROSS THE RIO
GRANDE PLAINS ARE EXPECTED TO REMAIN VFR THROUGH THE TAF PERIOD.
&&
.PREV DISCUSSION... /ISSUED 653 PM CST WED FEB 22 2012/
DISCUSSION...SEE MARINE SECTION BELOW.
MARINE...NAM SHOWS LOW VISIBILITIES MOVING INTO THE NORTHERN BAYS
THIS EVENING AS DOES THE RUC TO A LESSER EXTENT. AM LESS CONFIDENT
THAT SEA FOG WILL ADVECT INTO THE BAYS SOUTH OF PORT
ARANSAS...HOWEVER FARTHER S IN PORT ISABEL...VSBYS ARE 1/4SM.
THEREFORE HAVE DECIDED TO EXPAND THE MARINE DENSE FOG ADVISORY
INTO THE BAYS...INCLUDING SOUTH OF PORT ARANSAS...AND EXTEND
TIMING UNTIL 15Z. VISIBILITIES MAY VARY AT TIMES BUT FEEL VSBY
WILL BE 1NM OR LESS A MAJORITY OF THE TIME TONIGHT/EARLY THU
MORNING...AT LEAST ACROSS THE COASTAL WATERS AND PORT ARANSAS
NORTHWARD.
PREV DISCUSSION... /ISSUED 341 PM CST WED FEB 22 2012/
SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)...FOR POTENTIAL
REMAINS A CHALLENGE THROUGH THE FORECAST PERIOD. HAVE SEEN MARINE
FOG JUST OFFSHORE THE COAST ALL DAY...AND AS LIGHT WINDS SHIFT
BACK A BIT FROM SOUTHWEST TO SOUTH TONIGHT...MAY SEE SOME OF THAT
SEA FOG PUSH INLAND...PRIMARILY NORTH OF CORPUS CHRISTI BAY. IF
WINDS WERE TO TURN EAST OF SOUTH...AS THE NAM INDICATES GOT COULD
PUSH INLAND AT CORPUS CHRISTI AS WELL. RADIATION FOG COULD ALSO BE
AN ISSUE IN THE EAST...BUT THINK THAT THE SOUTHWEST WINDS WE/VE
HAD TODAY SHOULD HELP TO KEEP THINGS FROM GOING DENSE IN MOST
AREAS.
WITH HIGH TEMPERATURES TODAY INTO THE 80S...AND IN SOME
AREAS...MIDDLE 80S...DONT SEE A REASON TO EXPECT COOLER NUMBERS
TOMORROW. WIND PATTERN LOOKS QUITE SIMILAR TOMORROW TO WHAT WE SAW
TODAY AND EXPECT MAINLY HIGH CLOUDS ONCE ANY FOG BURNS OFF. HAVE
GONE A FEW DEGREES WARMER THAN PREVIOUS FORECAST WITH SOME
LOCATIONS IN THE SOUTHWEST PART OF THE FORECAST AREA TOUCHING 90
DEGREES. THIS MAY EVEN STILL BE A LITTLE CONSERVATIVE AS NAM/GFS
GUIDANCE FOR COTULLA/LAREDO ABOVE 90...SO WOULD NOT BE SURPRISED TO
SEE SOME TEMPS IN THE LOWER 90S FAR WEST.
NEXT CHALLENGE BECOMES TIMING OF THE COLD FRONT. ECMWF AND
CANADIAN MODEL STILL LAGGING BACK A BIT WITH FRONT TIMING. GFS/NAM
SHOW FRONT THROUGH THE ENTIRE FORECAST AREA BY 12Z FRIDAY...WHILE
EC AND CANADIAN BISECT THE FORECAST AREA AT 12Z. HAVE GONE WITH
THE QUICKER SOLUTION FOR TIMING. WITH A MODERATE WIND INCREASE
IMMEDIATELY BEHIND THE FRONT.
MARINE...HAVE EXTENDED DENSE FOG ADVISORY THROUGH THE NIGHT.
WITH SEA SURFACE TEMPERATURES IN THE LOW TO MID 60S...AND
DEWPOINTS IN THE MID TO UPPER 60S...AND THE WIND PATTERN NOT
CHANGING SIGNIFICANTLY SEE NO REASON THIS FOG WILL MOVE OUT OR
DISSIPATE. BAYS AREAS FROM PORT ARANSAS NORTHWARD MAY SEE THE FOG
DRIFT BACK IN TONIGHT AS WE LOSE THE SOUTHWEST WIND COMPONENT OVER
LAND THAT HAS HELPED TO PUSH IT OUT TODAY. AN ADVISORY MAY BE
NEEDED FOR THE BAYS THIS EVENING OR TONIGHT. SOUTHERN BAYS ARE A
CHALLENGE AS SOME MODELS INDICATE A SOUTHEASTERLY WIND DEVELOPING
WHICH WOULD BRING THE FOG BACK INTO THESE BAYS AS WELL...FOR NOW
STICKING WITH MORE OF A SOUTHERLY WIND AND THE BAYS SOUTH OF PORT
ARANSAS STAYING OUT OF THE DENSE FOG.
LONG TERM (FRIDAY THROUGH WEDNESDAY)...AFTER SEVERAL DAYS OF NOT
CATCHING ON TO THE POSSIBILITY OF THE UPPER LOW BEING MUCH SLOWER
TO MOVE OUT OF NORTHERN MEXICO...THIS FORECASTER ALONG WITH MOST
OF THE MODELS HAVE COME AROUND TOWARD THE SLOWER GFS SOLUTION. THE
UPPER LOW IS WELL DETACHED FROM THE MAIN STREAM AND THE STRONG UPPER
TROUGH MOVING INTO THE CENTRAL PLAINS FRIDAY MORNING PASSES BY WELL
TO THE NORTH. EVEN 12Z ECMWF IS IN LINE WITH THE GFS SHOWING THE
WEAKENING LOW MOVING ACROSS THE AREA BY 12Z SATURDAY. THE MODELS
ARE REASONABLY SIMILAR WITH THE TIMING OF THE COLD FRONT INTO THE
REGION EARLY FRIDAY MORNING. ADEQUATE MOISTURE AHEAD OF THE FRONT
AND APPROACH OF THE UPPER LEVEL JET STREAK SHOULD KEEP A THREAT FOR
SHOWERS MAINLY OVER THE SOUTHERN PORTIONS OF THE FORECAST AREA INTO
THE GULF WATERS FRIDAY INTO FRIDAY NIGHT. BUT MOST OF THIS MOISTURE
WILL BE ELEVATED AND SHOULD SEE SOME DRYING IN THE BOUNDARY LAYER
BY FRIDAY AFTERNOON. WITH VERY STRONG NORTH-NORTHEAST WINDS AND
RH VALUES FALLING TO 30-35 PERCENT IN THE AFTERNOON...WILL KEEP
THE FIRE WEATHER WATCH GOING FOR THE COASTAL COUNTIES. BUT THE
CONFIDENCE IS NOT REAL HIGH AS CLOUD COVER SHOULD PERSIST AND ANY
LIGHT PRECIPITATION COULD KEEP RH VALUES ELEVATED ABOVE RED FLAG
CRITERIA. THEREFORE...STILL A WATCH. CLOUDS LINGERING OVER THE AREA
WILL KEEP MINIMUMS A BIT HIGHER FOR SATURDAY MORNING BUT COOLER
FOR MAX TEMPS. STILL LEANING TOWARD THE ECMWF/CAN/UKMET HANDLING OF
UPPER PATTERN FOR EARLY NEXT WEEK AS GFS LOOKS TOO PROGRESSIVE WITH
THE UPPER TROUGH MOVING INTO THE WESTERN UNITED STATES OVER THE
WEEKEND. ONSHORE FLOW WILL STEADILY INCREASE SUNDAY THROUGH MONDAY
WITH MOSTLY CLOUDY SKIES PREVALENT. A SHORT WAVE TROUGH LIFTS INTO
THE UPPER MIDWEST BY MONDAY MORNING THAT SHOULD SEND A WEAK FRONTAL
BOUNDARY INTO NORTH TEXAS MONDAY BUT STALL NORTH OF THE AREA. A
POSITIVE TILT UPPER TROUGH WILL MOVE THROUGH THE ROCKIES BY TUESDAY
MORNING WITH A FRONT MOVING INTO THE AREA TUESDAY NIGHT. LOW LEVEL
WARM AIR ADVECTION AHEAD OF THE FRONT SHOULD ALLOW FOR ISOLATED
STREAMER SHOWERS OVER MOST OF THE AREA MONDAY NIGHT THROUGH
WEDNESDAY.
89/TMT
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 66 83 62 64 45 / 10 10 30 30 30
VICTORIA 63 83 56 63 44 / 10 10 30 20 20
LAREDO 67 90 62 65 45 / 0 10 20 30 30
ALICE 65 86 62 64 46 / 10 10 20 30 30
ROCKPORT 64 80 60 63 48 / 10 10 30 30 30
COTULLA 60 87 55 64 42 / 0 10 20 20 20
KINGSVILLE 65 85 62 64 47 / 10 10 30 30 30
NAVY CORPUS 66 82 62 63 51 / 10 10 30 30 30
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...FIRE WEATHER WATCH FROM FRIDAY MORNING THROUGH FRIDAY AFTERNOON
FOR THE FOLLOWING ZONES: ARANSAS...CALHOUN...KLEBERG...
NUECES...REFUGIO...SAN PATRICIO.
GM...DENSE FOG ADVISORY UNTIL 9 AM CST THURSDAY FOR THE FOLLOWING
ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT ARANSAS...
BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT O`CONNOR...
COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT 20 NM...
COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL
OUT 20 NM...WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20
TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP
CHANNEL FROM 20 TO 60 NM.
&&
$$
TE/81...SHORT TERM/AVIATION
AREA FORECAST DISCUSSION...UPDATED
NWS PUEBLO CO
652 AM MST THU FEB 23 2012
.UPDATE...
INSTABILITY IS OVERWHELMING DOWNSLOPE OFF THE PALMER DIVIDE...SO
HAVE UPDATED THE FORECAST TO INCREASE POPS A TOUCH MORE ACROSS
SOUTHERN EL PASO...PUEBLO AND THE WET MOUNTAINS. ALSO SEEING SNOW
EXPANDING ACROSS FREMONT COUNTY. EXPECT THIS BAND TO CONTINUE
SHIFTING SOUTHWARD...WITH SNOW DIMINISHING BY LATE MORNING ACROSS
EL PASO COUNTY. ALREADY STARTING TO SEE RADAR ECHOES DECREASING ACROSS
NORTHERN EL PASO COUNTY...THOUGH SUSPECT THAT INSTABILITY WILL
KEEP AT LEAST INTERMITTENT SNOW GOING OVER THIS AREA THROUGH THE
11 AM DURATION OF THE WINTER WEATHER ADVISORY. -KT
&&
.PREV DISCUSSION... /ISSUED 459 AM MST THU FEB 23 2012/
UPDATE...
HEAVY SNOW OVER THE PALMER DIVIDE...EVIDENT IN WEB CAMS...IS
STACKING UP QUICKER THAN EXPECTED THANKS TO THE AVAILABLE
INSTABILITY. MODELS STILL INDICATE BRUNT OF HEAVIER SNOW SHOULD BE
DONE BY 10 AM...BUT WITH SNOW COVERED ROADS WITH THE MORNING
COMMUTE HAVE OPTED TO PUT OUT A WINTER WEATHER ADVISORY FOR TELLER
AND NORTHERN EL PASO COUNTY THROUGH 11 AM. SNOWFALL AMOUNTS OF 2
TO 5 INCHES LOOK ACHIEVABLE. FORECAST UPDATE COMING OUT SHORTLY.
-KT
PREV DISCUSSION... /ISSUED 426 AM MST THU FEB 23 2012/
SHORT TERM...
(TODAY AND TONIGHT)
UPPER JET MOVING IN FROM THE NORTHWEST HAS JUST ABOUT ENDED HIGH
WINDS THREAT FOR MOST AREAS AS WINDS ALOFT QUICKLY ATTAIN MORE
FORWARD SHEAR. HAVE CANCELLED THE HIGH WIND WARNINGS FOR THE PIKES
PEAK REGION AND THE SAWATCH AND MOSQUITO RANGES...AND WILL BE TAKING
DOWN SOUTHERN AREAS WITHIN THE HOUR.
MEANWHILE...COLD FRONT HAS ALREADY DROPPED INTO EL PASO COUNTY WITH
NORTHERLY GUSTS TO 45 MPH OUT AT KABH. NICE BAND OF SNOW IN AREA
RADARS SINKING SOUTHWARD INTO NRN EL PASO COUNTY COINCIDENT WITH
UPPER JET FORCING AND INSTABILITY. HAVE EVEN HAD SOME LIGHTNING
STRIKES ACROSS NORTHERN COLORADO...INDICATIVE OF THE INSTABILITY
PRESENT WITH THIS SYSTEM. CENTRAL MOUNTAINS HAVE ALSO BEEN GETTING
IN ON THE ACTION...AND HAVE ALREADY HOISTED A WINTER WX ADVISORY FOR
THIS REGION DUE TO A COMBINATION OF THE MODERATE-HEAVY SNOW AND
BLOWING SNOW THROUGH THE MORNING. EXPECT THESE AREAS WILL SEE
SNOWFALL TOTALS IN THE 3-6 INCH RANGE ACROSS THE SAWATCH AND
MOSQUITO RANGES WHICH MAY BE A LITTLE SHY OF HITTING WIDESPREAD
ADVISORY AMOUNTS...BUT WITH THE BLOWING SNOW EXPECT THERE WILL BE
IMPACTS TO TRAVEL OVER THE MOUNTAIN PASSES. A LITTLE TRICKIER
FORECAST FOR TELLER AND EL PASO AS FAR AS SNOWFALL AMOUNTS GO.
SUSPECT THAT SOME AREAS WILL PICK UP A QUICK 1 TO 2
INCHES...PARTICULARLY ACROSS NORTHERN PORTIONS OF THE AREA. ROAD
SURFACES MAY QUICKLY BECOME SNOWPACKED WITH WIND RESULTING IN POOR
VISIBILITIES IN BLOWING SNOW ALONG I-25 OVER MONUMENT AND ACROSS
HIGHWAY 24 EAST OF KCOS DURING THE MORNING COMMUTE. WILL CONTINUE
TO MONITOR THIS REGION CLOSELY...BUT THINK EVENT SHOULD BE FAIRLY
BRIEF WITH SNOW WINDING DOWN BY 10 AM. NEXT QUESTION WILL BE HOW
FAR SOUTH THIS BAND WILL TRAVERSE. HIGH RES HRRR/AND RUC13 DIMINISH
THIS BAND AS IT MOVES SOUTHWARD INTO PUEBLO COUNTY AS IT BATTLES
STRONG DOWNSLOPE OFF THE PALMER DIVIDE. HOWEVER...THERE IS A 3 HOUR
WINDOW OF SOME FAIRLY STEEP LAPSE RATES ALOFT...SO ITS POSSIBLE THAT
THE EASTERN SLOPES OF THE WETS AS WELL AS PUEBLO COUNTY COULD SEE A
PERIOD OF RAIN/SNOW SHOWERS THIS MORNING AS THIS BAND MOVES
THROUGH. ACCUMULATIONS OF A COUPLE INCHES NOT OUT OF THE QUESTION
FOR THE WETS...WITH LITTLE TO NO ACCUMULATION EXPECTED FOR KPUB
EASTWARD AS TEMPERATURES WILL LIKELY REMAIN ABOVE FREEZING. HAVE
INCREASED POPS FOR THESE AREAS. MAJORITY OF THE SOUTHEAST PLAINS WILL
REMAIN DRY...THOUGH SOME ISOLATED RAIN/SNOW SHOWERS THIS MORNING NOT
OUT OF THE QUESTION. MAIN STORY FOR EASTERN AREAS WILL BE
WINDS...AS NORTH WINDS BEHIND THE FRONT QUICKLY INCREASE TO 25 TO 35
MPH WITH GUSTS TO NEAR 50 MPH. SHORT RANGE HIGH RES MODELS ALL KEEP
THE WINDS BELOW HIGH WIND CRITERIA...SO NO HIGH WIND HIGHLIGHTS ARE
ANTICIPATED FOR THE PLAINS AT THIS TIME.
WILL MAINTAIN SOME ISOLATED TO SCATTERED POPS IN AND NEAR THE
MOUNTAINS THIS EVENING WITH SOME LINGERING MOISTURE/INSTABILITY
AROUND. HOWEVER...CLEARING SKIES AND COLD AIR OVER THE REGION WILL
PROVIDE A FAVORABLE SET UP FOR A COLD NIGHT...WITH LOWS DROPPING
INTO THE TEENS AND 20S ACROSS THE LOWER ELEVATIONS...WITH SINGLE
DIGITS ABOVE AND BELOW ZERO ACROSS THE MOUNTAIN AREAS. -KT
LONG TERM...
(FRIDAY THROUGH THURSDAY)
.MORE WILD TEMPERATURE SWINGS AHEAD...
MAIN WX OF NOTE IN THE EXTENDED WILL BE THE IMPACT OF SEVERAL COLD
FRONTS...THE FIRST EARLY SUN...THEN EVEN STRONGER ADVANCES OF
MODIFIED ARCTIC AIR ON TUE AND NEXT THU. AT THIS TIME...IT LOOKS
LIKE MOST OF THE PRECIP WILL REMAIN N WITH THESE SYSTEMS...WITH
SOME POTENTIAL FOR UPSLOPE OR OVERRUNNING PRECIP OVR THE ERN MTS AND
PLAINS WITH EACH FRONT.
FRIDAY LOOK LIKE A BIT OF A TRANSITION DAY...WITH TEMPS REMAINING ON
THE COOL SIDE AND POPS ESSENTIALLY NIL THU FRI NIGHT. WINDS SHOULD
TAKE A BIT OF A BREAK AS THE UPPER RIDGE BUILDS EWD DURING THE DAY.
SAT...COULD BE ANOTHER WARM AND WINDY DAY. CORE OF A 90KT MID LEVEL
SPEED MAX WILL BE OVR THE SERN PORTION OF CO SAT AFTERNOON. LOOKS
LIKE WINDS WILL PROBABLY STAY CONFINED TO ELEVATIONS ABOVE ABOUT 10K
FEET...BUT THE ERN SLOPES FROM GREENHORN TO LA VETA PASS AND SWD TO
THE SPANISH PEAKS REGION WILL HAVE TO BE WATCHED FOR POTENTIALLY
STRONG WINDS BOTH SAT AND SAT NIGHT. OVR THE PLAINS...THE DOWNSLOPE
WINDS WILL AGAIN BOOST TEMPS TO AROUND 60 DEG OR HIGHER SAT
AFTERNOON. SHOULD SEE SHSN MOVE INTO THE CENTRAL MTS/CONTDVD BY LATE
SAT AFTERNOON...AND SEVERAL INCHES MAY ACCUMULATE N OF KMYP BY SUN
MORNING.
NEXT COLD FRONT SWEEPS THRU SE CO SUN MORNING. THE TREND OVR THE
PAST COUPLE OF DAYS HAS BEE4N TO KEEP MOST OF THE QG LIFT WITH THIS
SYSTEM TO OUR N...SO MAIN IMPACT LOOKS TO BE ANOTHER COLD DAY ON
SUN...WITH TEMPS IN THE 40S AT BEST. THIS FRONT IS QUICKLY FOLLOWED
BY A SECOND FRONT LATE MON OR TUE...ALTHOUGH TIMING DIFFERENCES
APPEAR BY THEN BETWEEN THE GFS AND ECMWF. GENERALLY WENT WITH THE GFS
SOLUTION...WHICH BRINGS H7 AIR OF MINUS 15 OR LOWER BY SUN...WHICH
WOULD MEAN TEMPS STRUGGLING TO GET OUT OF THE 30S OVR THE
PLAINS...AND MTN TEMPS IN THE TEENS AND 20S. THIS SYSTEM LOOKS A BIT
MORE AMPLIFIED THAN THE ONE OVR THE WEEKEND...SO COULD SEE A BETTER
SHOT OF WIDESPREAD PRECIP FOR OUR AREA. WITH TIMING DIFFERENCES
BEGINNING TO AMPLIFY LATE IN THE PERIOD...CONFIDENCE IN SPECIFIC WX
FOR LATER NEXT WEEK IS LOW...BUT IT APPEARS LIKELY THAT ANOTHER
SURGE IN COLD AIR WILL ARRIVE LATE IN THE WEEK...KEEPING US IN AN
UNSETTLED AND COLD PATTERN...MARCH COMING IN LIKE A LION. 44
AVIATION...
MVFR CIGS WILL SPREAD INTO KCOS THIS MORNING WITH -SHRA/SN EXPECTED
THROUGH 16Z. UNDER THE MORE INTENSE SNOW BANDS...COULD SEE SOME
BRIEF IFR CONDITIONS WITH ACCUMULATIONS OF 1 TO 2 INCHES POSSIBLE. NORTH
WINDS IN THE 25-40 KT RANGE WILL AFFECT KCOS AND KPUB THROUGH THE
MORNING. A BRIEF SHOT OF -SHRA/SN MAY AFFECT THE KPUB TAF SITE THIS
MORNING...BUT EXPECT THE SNOW BAND TO DIMINISH AS IT DROPS SOUTH OF
THE PALMER DIVIDE. WILL PUT A WINDOW OF MVFR-VFR CIGS AT KPUB WITH
VCSH DURING THE MID-LATE MORNING. KALS WILL SEE VFR CONDITIONS WITH
BREEZY NORTH WINDS. VFR CONDITIONS EXPECTED TONIGHT WITH LIGHTER
WINDS. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 11 AM MST THIS MORNING FOR COZ081-
082-084.
WINTER WEATHER ADVISORY UNTIL NOON MST TODAY FOR COZ058-060.
&&
$$
31/44
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
634 AM MST THU FEB 23 2012
.UPDATE...
ISSUED AT 625 AM MST THU FEB 23 2012
COLD FRONT PROGRESSING SOUTH THIS MORNING AND CURRENTLY BETWEEN
THE I70 CORRIDOR AND A LINE FROM MONTROSE TO THE GUNNISON VALLEY.
FARTHER EAST WITHIN THE BAROCLINIC ZONE...THE MOUNTAINS GETTING
POUNDED WITH SNOW AND WIND AND I70 IS CURRENTLY SHUT DOWN EAST OF
VAIL. HRRR DATA SHOWS PLENTY OF WIND PROGRESSING SOUTH WITH THE
FRONT AND HAVE ISSUED WIND ADVISORY FOR THE VALLEYS OF SOUTHEAST
UTAH AND SOUTHWEST COLORADO. IN THE MOUNTAINS...WINTER WEATHER
ADVISORY ADDRESSES THE COMBINATION OF SNOW AND WIND. A BURST OF
HEAVY SNOW AND WIND OCCURS WITH THE FRONT PASSAGE...BUT THE FRONT
IS MOVING FAIRLY QUICKLY WITH DRY ADVECTION OCCURRING BEHIND THE
FRONT. DO NOT EXPECT MUCH SNOW ACCUMULATION TO OCCUR THIS
AFTERNOON AS THE AIR MASS WILL BE VERY DRY. THERE IS A 2-3 HOUR
PERIOD OF NASTY CONDITIONS...AS EVIDENT ON THE WEB CAMS OVER VAIL
PASS AND EXPECT SIMILAR CONDITIONS TO OCCUR OVER MONARCH PASS.
THE SAN JUAN MOUNTAINS MAY NEED A WINTER WEATHER ADVISORY AS
WELL...BUT DYNAMICAL SUPPORT WILL BE MOVING DOWNSTREAM AS THE
FRONT MOVES INTO SW COLORADO. WILL CONTINUE TO MONITOR THIS SITUATION.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 217 AM MST THU FEB 23 2012
A STRONG COLD FRONT IS WORKING ITS WAY SOUTHWARD THROUGH NORTHWESTERN
COLORADO AT 09Z...EXPECT IT WILL WORK ITS WAY TO GJT AROUND 12Z.
FRONT IS PRETTY ENERGETIC WITH GOOD Q CONVERGENCE AND FRONTOGENETIC
FORCING. HOWEVER THE DEEPEST MOISTURE AND BEST CHANCES OF PCPN
WILL BE OVER THE NRN AND PORTIONS OF CNTRL MTNS WHERE WINTER
WEATHER HIGHLIGHTS ARE CURRENTLY IN PLACE. ITS STILL RAINING IN
CAG BEHIND THE FRONT BUT EXPECT THEY WILL TURN TO SNOW SHORTLY...WHILE
AT THE HIGHER ELEVATIONS A GOOD BURST OF HEAVY SNOW WILL PRECEDE
AND ACCOMPANY THE FRONT. WINDS STILL REMAIN A FACTOR WITH GUSTS UP
70KTS OVER SOME OF THE HIGHER MTNS (MT ABRAMS). AT THIS TIME THE
CURRENT HIGHLIGHTS ARE IN GOOD SHAPE WITH RESPECT TO AREAL
COVERAGE AND TIMING/INTENSITY OF SNOWFALL. ALSO THE WIND ADVISORY
OVER THE NW PLATEAU LOOKS IN GOOD SHAPE WITH SEVERAL RAWS SITES
INDICATING GUSTS OF 45 MPH OR HIGHER.
EXPECT THE INTENSITY OF SNOWFALL TO TAPER OFF BEHIND THE FRONT AS
MUCH DRIER AND COOLER AIR MOVES IN FROM THE NORTH. AS FOR THE LOWER
WESTERN VALLEYS OF COLORADO AND MOST ALL OF EASTERN UT...THIS
LOOKS LIKE MORE A WIND STORM THAN PCPN PRODUCER.
A FEW SHOWERS WILL LINGER OVER THE NW FACING SLOPES OF THE NRN AND
EAST CENTRAL MTNS TONIGHT...DECREASING AFTER MIDNIGHT. ELSEWHERE
DRY CONDITIONS WITH MUCH COOLER OVERNIGHT LOWS ARE EXPECTED.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 217 AM MST THU FEB 23 2012
FRIDAY...PROGRESSIVE RIDGE WILL MOVE ACROSS THE INTERMOUNTAIN WEST
ON FRIDAY AND WILL BRING DRY WEATHER. STRONG SURFACE BASED
INVERSIONS WILL KEEP VALLEYS COOL.
RIDGE CONTINUES DOWNSTREAM ON SATURDAY AND ALLOWS A STRONG PACIFIC
TROUGH TO MOVE ACROSS THE NWRN CONUS. THE 00Z MODEL SUITE SUPPORTS
YESTERDAYS 12Z TREND THAT THE DIGGING TROUGH WILL NOT BE AS
PRONOUNCED. DEEP SURFACE CYCLONE TRACKS ACROSS THE NRN
PLAINS...BUT THIS CYCLONE WILL COVER PLENTY OF TERRITORY. PRESSURE
GRADIENTS WILL TIGHTEN SIGNIFICANTLY SATURDAY AFTERNOON ONCE THE
SURFACE TROUGH DEVELOPS IN THE PLAINS. THE GREATEST IMPACT FROM
THIS PACIFIC WAVE MAY VERY WELL BE WIND AS THIS SYSTEM HARDLY
ENTRAINS ANY MOISTURE. LATEST GUDIANCE SHOW DEW POINTS CRASHING
INTO THE SINGLE DIGITS AND TEENS IN THE AFTERNOON ONCE THE SURFACE
BASED INVERSIONS MIX OUT. THE BEST DYNAMICAL LIFT...COINCIDING
WITH STRONG MID LEVEL COLD ADVECTION...OCCURS SATURDAY EVENING
WITH THE BEST CHANCE OF SNOW OCCURRING OVER THE NRN MOUNTAINS.
MODERATE TO HEAVY SNOW ACROSS THE PARK RANGE IS POSSIBLE FOR 3-4
HOURS AS THE COLD POCKET SWEEPS ACROSS NW COLORADO. OTHERWISE THIS
SYSTEM IS MOISTURE STARVED AND DIABATIC COOLING WILL HAVE A TOUGH
TIME MOISTENING THE AIR MASS WITH PRECIPITABLE WATER CONTENT OF
ONLY A QUARTER INCH.
SUNDAY THROUGH TUESDAY...A SECONDARY SHORT WAVE DIGS INTO THE GREAT
BASIN ON SUNDAY NIGHT. THIS WILL BE FOLLOWED BY ANOTHER DIGGING
WAVE FROM ALBERTA ON TUESDAY THAT REINFORCES THE COLDER AIR MASS
ACROSS THE REGION. NEITHER OF THESE FEATURES WILL HAVE MUCH
MOISTURE TO WORK WITH...BUT DOES KEEP THE AIR MASS COOL AND
UNSETTLED WITH A CHANCE OF MOUNTAIN SNOW SHOWERS.
APPEARS THAT NEXT WEDNESDAY WILL BE DRY AS TRANSITORY RIDGE MOVES
ACROSS THE REGION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z EARLY FRIDAY MORNING)
ISSUED AT 217 AM MST THU FEB 23 2012
A STRONG COLD FRONT IS PUSHING SOUTHWARD THROUGH NORTHWEST
COLORADO AT 12Z...RESULTING IN CONTINUED GUSTY WINDS AND AN
INCREASE IN SNOWFALL FOR THE NORTHERN MOUNTAINS AND VALLEYS. WINDS
GUSTING TO NEAR 50 MPH IN THE VALLEYS...WITH MTN TOP WINDS
APPROACHING 65 MPH CAN BE EXPECTED THROUGH 15Z. PREVAILING WIND
DIRECTION WILL BE SHIFTING FROM THE WEST TO NORTHWEST AS THE FRONT
PASSES. EXPECT CIGS AND VSBYS TO DROP INTO IFR THRESHOLDS FOR
NORTHERN SITES SUCH AS KCAG...KHDN AND KSBS. KEGE AND KASE WILL
ALSO SEE A DROP IN CIGS AFTER 12Z AS THE FRONT PUSHES THROUGH THE
CENTRAL ZONES. GRADUAL IMPROVEMENT IS EXPECTED LATER THIS AFTERNOON
AT THE ABOVE MENTIONED SITES...OTHERWISE VFR CONDITIONS EXPECTED
TO PERSIST AT THE LOWER VALLEY SITES OF WESTERN COLORADO AND
EASTERN UTAH THROUGH THIS FORECAST PERIOD.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WIND ADVISORY UNTIL 6 PM MST THIS EVENING FOR COZ006>008-011-014-
020>022.
WINTER WEATHER ADVISORY UNTIL 2 PM MST THIS AFTERNOON FOR COZ003-
009-012.
WINTER STORM WARNING UNTIL 2 PM MST THIS AFTERNOON FOR COZ010.
WINTER STORM WARNING UNTIL 11 AM MST THIS MORNING FOR COZ004-005-
013.
WIND ADVISORY UNTIL 11 AM MST THIS MORNING FOR COZ001-002.
UT...WIND ADVISORY UNTIL 6 PM MST THIS EVENING FOR UTZ022-027-029.
&&
$$
UPDATE...PF
SHORT TERM...MC
LONG TERM....PF
AVIATION...MC
AREA FORECAST DISCUSSION...UPDATED
NWS PUEBLO CO
459 AM MST THU FEB 23 2012
.UPDATE...
HEAVY SNOW OVER THE PALMER DIVIDE...EVIDENT IN WEB CAMS...IS
STACKING UP QUICKER THAN EXPECTED THANKS TO THE AVAILABLE
INSTABILITY. MODELS STILL INDICATE BRUNT OF HEAVIER SNOW SHOULD BE
DONE BY 10 AM...BUT WITH SNOW COVERED ROADS WITH THE MORNING
COMMUTE HAVE OPTED TO PUT OUT A WINTER WEATHER ADVISORY FOR TELLER
AND NORTHERN EL PASO COUNTY THROUGH 11 AM. SNOWFALL AMOUNTS OF 2
TO 5 INCHES LOOK ACHIEVABLE. FORECAST UPDATE COMING OUT SHORTLY.
-KT
&&
.PREV DISCUSSION... /ISSUED 426 AM MST THU FEB 23 2012/
SHORT TERM...
(TODAY AND TONIGHT)
UPPER JET MOVING IN FROM THE NORTHWEST HAS JUST ABOUT ENDED HIGH
WINDS THREAT FOR MOST AREAS AS WINDS ALOFT QUICKLY ATTAIN MORE
FORWARD SHEAR. HAVE CANCELLED THE HIGH WIND WARNINGS FOR THE PIKES
PEAK REGION AND THE SAWATCH AND MOSQUITO RANGES...AND WILL BE TAKING
DOWN SOUTHERN AREAS WITHIN THE HOUR.
MEANWHILE...COLD FRONT HAS ALREADY DROPPED INTO EL PASO COUNTY WITH
NORTHERLY GUSTS TO 45 MPH OUT AT KABH. NICE BAND OF SNOW IN AREA
RADARS SINKING SOUTHWARD INTO NRN EL PASO COUNTY COINCIDENT WITH
UPPER JET FORCING AND INSTABILITY. HAVE EVEN HAD SOME LIGHTNING
STRIKES ACROSS NORTHERN COLORADO...INDICATIVE OF THE INSTABILITY
PRESENT WITH THIS SYSTEM. CENTRAL MOUNTAINS HAVE ALSO BEEN GETTING
IN ON THE ACTION...AND HAVE ALREADY HOISTED A WINTER WX ADVISORY FOR
THIS REGION DUE TO A COMBINATION OF THE MODERATE-HEAVY SNOW AND
BLOWING SNOW THROUGH THE MORNING. EXPECT THESE AREAS WILL SEE
SNOWFALL TOTALS IN THE 3-6 INCH RANGE ACROSS THE SAWATCH AND
MOSQUITO RANGES WHICH MAY BE A LITTLE SHY OF HITTING WIDESPREAD
ADVISORY AMOUNTS...BUT WITH THE BLOWING SNOW EXPECT THERE WILL BE
IMPACTS TO TRAVEL OVER THE MOUNTAIN PASSES. A LITTLE TRICKIER
FORECAST FOR TELLER AND EL PASO AS FAR AS SNOWFALL AMOUNTS GO.
SUSPECT THAT SOME AREAS WILL PICK UP A QUICK 1 TO 2
INCHES...PARTICULARLY ACROSS NORTHERN PORTIONS OF THE AREA. ROAD
SURFACES MAY QUICKLY BECOME SNOWPACKED WITH WIND RESULTING IN POOR
VISIBILITIES IN BLOWING SNOW ALONG I-25 OVER MONUMENT AND ACROSS
HIGHWAY 24 EAST OF KCOS DURING THE MORNING COMMUTE. WILL CONTINUE
TO MONITOR THIS REGION CLOSELY...BUT THINK EVENT SHOULD BE FAIRLY
BRIEF WITH SNOW WINDING DOWN BY 10 AM. NEXT QUESTION WILL BE HOW
FAR SOUTH THIS BAND WILL TRAVERSE. HIGH RES HRRR/AND RUC13 DIMINISH
THIS BAND AS IT MOVES SOUTHWARD INTO PUEBLO COUNTY AS IT BATTLES
STRONG DOWNSLOPE OFF THE PALMER DIVIDE. HOWEVER...THERE IS A 3 HOUR
WINDOW OF SOME FAIRLY STEEP LAPSE RATES ALOFT...SO ITS POSSIBLE THAT
THE EASTERN SLOPES OF THE WETS AS WELL AS PUEBLO COUNTY COULD SEE A
PERIOD OF RAIN/SNOW SHOWERS THIS MORNING AS THIS BAND MOVES
THROUGH. ACCUMULATIONS OF A COUPLE INCHES NOT OUT OF THE QUESTION
FOR THE WETS...WITH LITTLE TO NO ACCUMULATION EXPECTED FOR KPUB
EASTWARD AS TEMPERATURES WILL LIKELY REMAIN ABOVE FREEZING. HAVE
INCREASED POPS FOR THESE AREAS. MAJORITY OF THE SOUTHEAST PLAINS WILL
REMAIN DRY...THOUGH SOME ISOLATED RAIN/SNOW SHOWERS THIS MORNING NOT
OUT OF THE QUESTION. MAIN STORY FOR EASTERN AREAS WILL BE
WINDS...AS NORTH WINDS BEHIND THE FRONT QUICKLY INCREASE TO 25 TO 35
MPH WITH GUSTS TO NEAR 50 MPH. SHORT RANGE HIGH RES MODELS ALL KEEP
THE WINDS BELOW HIGH WIND CRITERIA...SO NO HIGH WIND HIGHLIGHTS ARE
ANTICIPATED FOR THE PLAINS AT THIS TIME.
WILL MAINTAIN SOME ISOLATED TO SCATTERED POPS IN AND NEAR THE
MOUNTAINS THIS EVENING WITH SOME LINGERING MOISTURE/INSTABILITY
AROUND. HOWEVER...CLEARING SKIES AND COLD AIR OVER THE REGION WILL
PROVIDE A FAVORABLE SET UP FOR A COLD NIGHT...WITH LOWS DROPPING
INTO THE TEENS AND 20S ACROSS THE LOWER ELEVATIONS...WITH SINGLE
DIGITS ABOVE AND BELOW ZERO ACROSS THE MOUNTAIN AREAS. -KT
LONG TERM...
(FRIDAY THROUGH THURSDAY)
..MORE WILD TEMPERATURE SWINGS AHEAD...
MAIN WX OF NOTE IN THE EXTENDED WILL BE THE IMPACT OF SEVERAL COLD
FRONTS...THE FIRST EARLY SUN...THEN EVEN STRONGER ADVANCES OF
MODIFIED ARCTIC AIR ON TUE AND NEXT THU. AT THIS TIME...IT LOOKS
LIKE MOST OF THE PRECIP WILL REMAIN N WITH THESE SYSTEMS...WITH
SOME POTENTIAL FOR UPSLOPE OR OVERRUNNING PRECIP OVR THE ERN MTS AND
PLAINS WITH EACH FRONT.
FRIDAY LOOK LIKE A BIT OF A TRANSITION DAY...WITH TEMPS REMAINING ON
THE COOL SIDE AND POPS ESSENTIALLY NIL THU FRI NIGHT. WINDS SHOULD
TAKE A BIT OF A BREAK AS THE UPPER RIDGE BUILDS EWD DURING THE DAY.
SAT...COULD BE ANOTHER WARM AND WINDY DAY. CORE OF A 90KT MID LEVEL
SPEED MAX WILL BE OVR THE SERN PORTION OF CO SAT AFTERNOON. LOOKS
LIKE WINDS WILL PROBABLY STAY CONFINED TO ELEVATIONS ABOVE ABOUT 10K
FEET...BUT THE ERN SLOPES FROM GREENHORN TO LA VETA PASS AND SWD TO
THE SPANISH PEAKS REGION WILL HAVE TO BE WATCHED FOR POTENTIALLY
STRONG WINDS BOTH SAT AND SAT NIGHT. OVR THE PLAINS...THE DOWNSLOPE
WINDS WILL AGAIN BOOST TEMPS TO AROUND 60 DEG OR HIGHER SAT
AFTERNOON. SHOULD SEE SHSN MOVE INTO THE CENTRAL MTS/CONTDVD BY LATE
SAT AFTERNOON...AND SEVERAL INCHES MAY ACCUMULATE N OF KMYP BY SUN
MORNING.
NEXT COLD FRONT SWEEPS THRU SE CO SUN MORNING. THE TREND OVR THE
PAST COUPLE OF DAYS HAS BEE4N TO KEEP MOST OF THE QG LIFT WITH THIS
SYSTEM TO OUR N...SO MAIN IMPACT LOOKS TO BE ANOTHER COLD DAY ON
SUN...WITH TEMPS IN THE 40S AT BEST. THIS FRONT IS QUICKLY FOLLOWED
BY A SECOND FRONT LATE MON OR TUE...ALTHOUGH TIMING DIFFERENCES
APPEAR BY THEN BETWEEN THE GFS AND ECMWF. GENERALLY WENT WITH THE GFS
SOLUTION...WHICH BRINGS H7 AIR OF MINUS 15 OR LOWER BY SUN...WHICH
WOULD MEAN TEMPS STRUGGLING TO GET OUT OF THE 30S OVR THE
PLAINS...AND MTN TEMPS IN THE TEENS AND 20S. THIS SYSTEM LOOKS A BIT
MORE AMPLIFIED THAN THE ONE OVR THE WEEKEND...SO COULD SEE A BETTER
SHOT OF WIDESPREAD PRECIP FOR OUR AREA. WITH TIMING DIFFERENCES
BEGINNING TO AMPLIFY LATE IN THE PERIOD...CONFIDENCE IN SPECIFIC WX
FOR LATER NEXT WEEK IS LOW...BUT IT APPEARS LIKELY THAT ANOTHER
SURGE IN COLD AIR WILL ARRIVE LATE IN THE WEEK...KEEPING US IN AN
UNSETTLED AND COLD PATTERN...MARCH COMING IN LIKE A LION. 44
AVIATION...
MVFR CIGS WILL SPREAD INTO KCOS THIS MORNING WITH -SHRA/SN EXPECTED
THROUGH 16Z. UNDER THE MORE INTENSE SNOW BANDS...COULD SEE SOME
BRIEF IFR CONDITIONS WITH ACCUMULATIONS OF 1 TO 2 INCHES POSSIBLE. NORTH
WINDS IN THE 25-40 KT RANGE WILL AFFECT KCOS AND KPUB THROUGH THE
MORNING. A BRIEF SHOT OF -SHRA/SN MAY AFFECT THE KPUB TAF SITE THIS
MORNING...BUT EXPECT THE SNOW BAND TO DIMINISH AS IT DROPS SOUTH OF
THE PALMER DIVIDE. WILL PUT A WINDOW OF MVFR-VFR CIGS AT KPUB WITH
VCSH DURING THE MID-LATE MORNING. KALS WILL SEE VFR CONDITIONS WITH
BREEZY NORTH WINDS. VFR CONDITIONS EXPECTED TONIGHT WITH LIGHTER
WINDS. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 11 AM MST THIS MORNING FOR COZ081-
082-084.
WINTER WEATHER ADVISORY UNTIL NOON MST TODAY FOR COZ058-060.
&&
$$
31/44
AREA FORECAST DISCUSSION
NWS PUEBLO CO
426 AM MST THU FEB 23 2012
.SHORT TERM...
(TODAY AND TONIGHT)
UPPER JET MOVING IN FROM THE NORTHWEST HAS JUST ABOUT ENDED HIGH
WINDS THREAT FOR MOST AREAS AS WINDS ALOFT QUICKLY ATTAIN MORE
FORWARD SHEAR. HAVE CANCELLED THE HIGH WIND WARNINGS FOR THE PIKES
PEAK REGION AND THE SAWATCH AND MOSQUITO RANGES...AND WILL BE TAKING
DOWN SOUTHERN AREAS WITHIN THE HOUR.
MEANWHILE...COLD FRONT HAS ALREADY DROPPED INTO EL PASO COUNTY WITH
NORTHERLY GUSTS TO 45 MPH OUT AT KABH. NICE BAND OF SNOW IN AREA
RADARS SINKING SOUTHWARD INTO NRN EL PASO COUNTY COINCIDENT WITH
UPPER JET FORCING AND INSTABILITY. HAVE EVEN HAD SOME LIGHTNING
STRIKES ACROSS NORTHERN COLORADO...INDICATIVE OF THE INSTABILITY
PRESENT WITH THIS SYSTEM. CENTRAL MOUNTAINS HAVE ALSO BEEN GETTING
IN ON THE ACTION...AND HAVE ALREADY HOISTED A WINTER WX ADVISORY FOR
THIS REGION DUE TO A COMBINATION OF THE MODERATE-HEAVY SNOW AND
BLOWING SNOW THROUGH THE MORNING. EXPECT THESE AREAS WILL SEE
SNOWFALL TOTALS IN THE 3-6 INCH RANGE ACROSS THE SAWATCH AND
MOSQUITO RANGES WHICH MAY BE A LITTLE SHY OF HITTING WIDESPREAD
ADVISORY AMOUNTS...BUT WITH THE BLOWING SNOW EXPECT THERE WILL BE
IMPACTS TO TRAVEL OVER THE MOUNTAIN PASSES. A LITTLE TRICKIER
FORECAST FOR TELLER AND EL PASO AS FAR AS SNOWFALL AMOUNTS GO.
SUSPECT THAT SOME AREAS WILL PICK UP A QUICK 1 TO 2
INCHES...PARTICULARLY ACROSS NORTHERN PORTIONS OF THE AREA. ROAD
SURFACES MAY QUICKLY BECOME SNOWPACKED WITH WIND RESULTING IN POOR
VISIBILITIES IN BLOWING SNOW ALONG I-25 OVER MONUMENT AND ACROSS
HIGHWAY 24 EAST OF KCOS DURING THE MORNING COMMUTE. WILL CONTINUE
TO MONITOR THIS REGION CLOSELY...BUT THINK EVENT SHOULD BE FAIRLY
BRIEF WITH SNOW WINDING DOWN BY 10 AM. NEXT QUESTION WILL BE HOW
FAR SOUTH THIS BAND WILL TRAVERSE. HIGH RES HRRR/AND RUC13 DIMINISH
THIS BAND AS IT MOVES SOUTHWARD INTO PUEBLO COUNTY AS IT BATTLES
STRONG DOWNSLOPE OFF THE PALMER DIVIDE. HOWEVER...THERE IS A 3 HOUR
WINDOW OF SOME FAIRLY STEEP LAPSE RATES ALOFT...SO ITS POSSIBLE THAT
THE EASTERN SLOPES OF THE WETS AS WELL AS PUEBLO COUNTY COULD SEE A
PERIOD OF RAIN/SNOW SHOWERS THIS MORNING AS THIS BAND MOVES
THROUGH. ACCUMULATIONS OF A COUPLE INCHES NOT OUT OF THE QUESTION
FOR THE WETS...WITH LITTLE TO NO ACCUMULATION EXPECTED FOR KPUB
EASTWARD AS TEMPERATURES WILL LIKELY REMAIN ABOVE FREEZING. HAVE
INCREASED POPS FOR THESE AREAS. MAJORITY OF THE SOUTHEAST PLAINS WILL
REMAIN DRY...THOUGH SOME ISOLATED RAIN/SNOW SHOWERS THIS MORNING NOT
OUT OF THE QUESTION. MAIN STORY FOR EASTERN AREAS WILL BE
WINDS...AS NORTH WINDS BEHIND THE FRONT QUICKLY INCREASE TO 25 TO 35
MPH WITH GUSTS TO NEAR 50 MPH. SHORT RANGE HIGH RES MODELS ALL KEEP
THE WINDS BELOW HIGH WIND CRITERIA...SO NO HIGH WIND HIGHLIGHTS ARE
ANTICIPATED FOR THE PLAINS AT THIS TIME.
WILL MAINTAIN SOME ISOLATED TO SCATTERED POPS IN AND NEAR THE
MOUNTAINS THIS EVENING WITH SOME LINGERING MOISTURE/INSTABILITY
AROUND. HOWEVER...CLEARING SKIES AND COLD AIR OVER THE REGION WILL
PROVIDE A FAVORABLE SET UP FOR A COLD NIGHT...WITH LOWS DROPPING
INTO THE TEENS AND 20S ACROSS THE LOWER ELEVATIONS...WITH SINGLE
DIGITS ABOVE AND BELOW ZERO ACROSS THE MOUNTAIN AREAS. -KT
.LONG TERM...
(FRIDAY THROUGH THURSDAY)
...MORE WILD TEMPERATURE SWINGS AHEAD...
MAIN WX OF NOTE IN THE EXTENDED WILL BE THE IMPACT OF SEVERAL COLD
FRONTS...THE FIRST EARLY SUN...THEN EVEN STRONGER ADVANCES OF
MODIFIED ARCTIC AIR ON TUE AND NEXT THU. AT THIS TIME...IT LOOKS
LIKE MOST OF THE PRECIP WILL REMAIN N WITH THESE SYSTEMS...WITH
SOME POTENTIAL FOR UPSLOPE OR OVERRUNNING PRECIP OVR THE ERN MTS AND
PLAINS WITH EACH FRONT.
FRIDAY LOOK LIKE A BIT OF A TRANSITION DAY...WITH TEMPS REMAINING ON
THE COOL SIDE AND POPS ESSENTIALLY NIL THU FRI NIGHT. WINDS SHOULD
TAKE A BIT OF A BREAK AS THE UPPER RIDGE BUILDS EWD DURING THE DAY.
SAT...COULD BE ANOTHER WARM AND WINDY DAY. CORE OF A 90KT MID LEVEL
SPEED MAX WILL BE OVR THE SERN PORTION OF CO SAT AFTERNOON. LOOKS
LIKE WINDS WILL PROBABLY STAY CONFINED TO ELEVATIONS ABOVE ABOUT 10K
FEET...BUT THE ERN SLOPES FROM GREENHORN TO LA VETA PASS AND SWD TO
THE SPANISH PEAKS REGION WILL HAVE TO BE WATCHED FOR POTENTIALLY
STRONG WINDS BOTH SAT AND SAT NIGHT. OVR THE PLAINS...THE DOWNSLOPE
WINDS WILL AGAIN BOOST TEMPS TO AROUND 60 DEG OR HIGHER SAT
AFTERNOON. SHOULD SEE SHSN MOVE INTO THE CENTRAL MTS/CONTDVD BY LATE
SAT AFTERNOON...AND SEVERAL INCHES MAY ACCUMULATE N OF KMYP BY SUN
MORNING.
NEXT COLD FRONT SWEEPS THRU SE CO SUN MORNING. THE TREND OVR THE
PAST COUPLE OF DAYS HAS BEE4N TO KEEP MOST OF THE QG LIFT WITH THIS
SYSTEM TO OUR N...SO MAIN IMPACT LOOKS TO BE ANOTHER COLD DAY ON
SUN...WITH TEMPS IN THE 40S AT BEST. THIS FRONT IS QUICKLY FOLLOWED
BY A SECOND FRONT LATE MON OR TUE...ALTHOUGH TIMING DIFFERENCES
APPEAR BY THEN BETWEEN THE GFS AND ECMWF. GENERALLY WENT WITH THE GFS
SOLUTION...WHICH BRINGS H7 AIR OF MINUS 15 OR LOWER BY SUN...WHICH
WOULD MEAN TEMPS STRUGGLING TO GET OUT OF THE 30S OVR THE
PLAINS...AND MTN TEMPS IN THE TEENS AND 20S. THIS SYSTEM LOOKS A BIT
MORE AMPLIFIED THAN THE ONE OVR THE WEEKEND...SO COULD SEE A BETTER
SHOT OF WIDESPREAD PRECIP FOR OUR AREA. WITH TIMING DIFFERENCES
BEGINNING TO AMPLIFY LATE IN THE PERIOD...CONFIDENCE IN SPECIFIC WX
FOR LATER NEXT WEEK IS LOW...BUT IT APPEARS LIKELY THAT ANOTHER
SURGE IN COLD AIR WILL ARRIVE LATE IN THE WEEK...KEEPING US IN AN
UNSETTLED AND COLD PATTERN...MARCH COMING IN LIKE A LION. ROSE
&&
.AVIATION...
MVFR CIGS WILL SPREAD INTO KCOS THIS MORNING WITH -SHRA/SN EXPECTED
THROUGH 16Z. UNDER THE MORE INTENSE SNOW BANDS...COULD SEE SOME
BRIEF IFR CONDITIONS WITH ACCUMULATIONS OF 1 TO 2 INCHES POSSIBLE. NORTH
WINDS IN THE 25-40 KT RANGE WILL AFFECT KCOS AND KPUB THROUGH THE
MORNING. A BRIEF SHOT OF -SHRA/SN MAY AFFECT THE KPUB TAF SITE THIS
MORNING...BUT EXPECT THE SNOW BAND TO DIMINISH AS IT DROPS SOUTH OF
THE PALMER DIVIDE. WILL PUT A WINDOW OF MVFR-VFR CIGS AT KPUB WITH
VCSH DURING THE MID-LATE MORNING. KALS WILL SEE VFR CONDITIONS WITH
BREEZY NORTH WINDS. VFR CONDITIONS EXPECTED TONIGHT WITH LIGHTER
WINDS. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON MST TODAY FOR COZ058-060.
HIGH WIND WARNING UNTIL 5 AM MST EARLY THIS MORNING FOR COZ072-
073-075-077>080.
&&
$$
31/44
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1025 AM EST THU FEB 23 2012
.UPDATE...
CURRENT SATELLITE ANALYSIS SHOWS SCATTERED CLOUDS IN NORTH AND
CENTRAL GEORGIA AND A MORE BROKEN TO OVERCAST CLOUD DECK IN
COLUMBUS...EAST INTO MACON. ADJUSTED THE SKY GRIDS TO REPRESENT
THIS. CURRENT SURFACE DEWPOINTS WERE HIGHER THAN FORECAST. AS
SUCH...POPULATED THE GRIDS WITH THE CURRENT 12Z RUC DEWPOINTS THAT
WERE MORE REPRESENTATIVE OF CURRENT OBSERVATIONS AND TRENDS. THIS
MEANT THAT SOME AREAS SAW AN INCREASE OF 5 DEGREES OR MORE IN
DEWPOINT TEMPS. THE NAM SEEMS TO BE UNREALISTICALLY DRYING US OUT
THIS AFTERNOON...AS SUCH BELIEVE THAT THE 06Z NAM MIGHT BE UNDER
REPRESENTING THE CHANCE OF THUNDER. WILL WAIT FOR 12Z GUIDANCE TO
BETTER PIN DOWN THUNDERSTORMS THIS AFTERNOON...EVENING AND INTO
THE OVERNIGHT HOURS. ALSO ADJUSTED THE TEMPS TO BETTER REPRESENT
CURRENT WARMING TRENDS.
ARG
&&
.SHORT TERM /TODAY THROUGH SATURDAY NIGHT/...
/ISSUED 411 AM EST THU FEB 23 2012/
EXPECT TO REMAIN STORM FREE TODAY WITH AREA BETWEEN SYSTEMS.
MODELS DIFFER SLIGHTLY WITH TIMING AND STRENGTH OF NEXT FRONTAL
SYSTEM. THE FASTER AND MORE AGGRESSIVE GFS MODEL PUSHES A COLD
FRONT INTO NW GA SHORTLY AFTER MIDNIGHT TONIGHT...WHILE NAM AND
ECMWF HOLD OFF UNTIL NEARLY 6-7 AM FRIDAY MORNING. PREFER A BLEND
IN THE MORE AGGRESSIVE GFS AND ECMWF MODELS... AS BOTH MODELS SHOW
A GREATER POTENTIAL FOR MORE WIDESPREAD SHOWER AND THUNDERSTORM
ACTIVITY AHEAD OF THE COLD FRONT...WITH STRONGER UPPER SUPPORT
DIGGING SLIGHTLY FURTHER SOUTH WHILE 600-1200 MUCAPE NOSE INTO
CENTRAL AND NORTH GA LATER THIS EVENING. THIS COUPLED WITH AMPLE
DEEP-LAYER SHEAR COURTESY OF A 50+KT LOW LEVEL SWLY JET SUGGEST
THE POTENTIAL FOR ISOLATED STRONG TO SEVERE STORMS LATER THIS
EVENING AND POSSIBLY CONTINUING OVERNIGHT. SPC HAS NORTH AND PARTS
OF WEST CENTRAL GA IN A SLIGHT RISK AREA FOR TONIGHT AND DESPITE
THE FRONT MOVING INTO THE STATE DURING THE OVERNIGHT HOURS...
SUSPECT LARGE SCALE ASCENT...DEEP- LAYER SHEAR AND FRONTAL FORCING
WILL BE SUFFICIENT FOR ISOLATED SEVERE STORM DEVELOPMENT IN THE
SLIGHT RISK AREA. THE GREATER SEVERE STORM THREAT SEEMS TO BE
BETWEEN 10 PM THIS EVENING AND 6 AM FRIDAY MORNING...AND MAINLY
NORTH OF A LA GRANGE TO ATHENS LINE. ALTHOUGH LARGE HAIL AND
DAMAGING WINDS FROM BOWING STORMS WILL LIKELY BE THE MAIN THREATS
TONIGHT... HIGH 200+ HELICITY VALUES ALSO SUGGEST THE POTENTIAL
FOR A FEW TORNADOES. THE THUNDERSTORM THREAT SHOULD PUSH SOUTH AND
EAST OF THE AREA BY FRIDAY AFTERNOON...ALTHOUGH CLOUDS AND
ISOLATED LIGHT RAIN SHOWERS MAY LINGER THROUGH FRIDAY AFTERNOON AS
THE AXIS OF THE LONG-WAVE UPPER TROUGH DOES NOT PUSH EAST OF THE
STATE UNTIL FRIDAY EVENING. CLEARING...BREEZY AND COOLER
CONDITIONS ARE ON TAP FOR FRIDAY NIGHT AS HIGH PRESSURE BUILDS IN
FROM THE WNW. MOS GUIDANCE NUMBERS WERE FAIRLY CLOSE AND
REASONABLE...SO TOOK A BLEND THROUGH THE SHORT TERM.
LONG TERM /SATURDAY THROUGH WEDNESDAY/...
/ISSUED 411 AM EST THU FEB 23 2012/
STILL HOLDING ONTO A DRY FORECAST FOR SATURDAY... BUT SUNDAY IS
LOOKING WETTER AS BOTH GFS AND ECMWF ARE SHOWING A BAJA UPPER LOW
FINALLY KICKING EAST AND TRAVERSING THE STATE ON SUNDAY. THIS FEATURE
WILL ENHANCE ISENTROPIC LIFT AND SPREAD RAIN SHOWERS INTO AT LEAST
SOUTH AND CENTRAL GA BY EARLY SUNDAY AFTERNOON. BOTH MODELS SHOW A
WEDGE OF COOL AIR BEING OVERRUN BY A MOIST SOUTHERLY MID LEVEL
FLOW... RESULTING IN A STABLE RAIN SUNDAY AND SUNDAY NIGHT. PREFER
THE DRIER GFS SOLUTION FOR MONDAY AS THIS UPPER SHORT WAVE PUSHES
EAST AND GIVES THE AREA A BREAK. THIS BEFORE ANOTHER FRONTAL
SYSTEM SPREADS A CHANCE OF SHOWERS INTO THE AREA BEGINNING TUESDAY
AND THEN ISOLATED THUNDERSTORMS ON WEDNESDAY JUST AHEAD OF THE
COLD FRONT THAT GFS PUSHES ACROSS THE AREA BY EARLY WEDNESDAY
EVENING.
39
AVIATION...
12Z UPDATE...
/ISSUED 657 AM EST THU FEB 23 2012/
IMPROVING CONDITIONS EXPECTED THROUGH THE DAY...WITH VFR EXPECTED
BY 18Z. CIGS WILL DEGRADE INTO THE OVERNIGHT HOURS AS SHORTWAVE
MOVES INTO THE AREA. EXPECT MVFR BY 09Z. CONDITIONS WILL IMPROVE
QUICKLY AFTER 12Z FRI. BEST RAIN CHANCES 09-12Z. SW WINDS WILL
INCREASE TO 12-14KTS BY 18Z...WITH GUSTS TO 22-25KTS. SPEEDS
REMAIN HIGH OVERNIGHT WITH W-WSW WINDS AT 8-12KTS.
//ATL CONFIDENCE...12Z UPDATE...
HIGH ON WINDS AND DIRECTION.
MEDIUM ON ALL OTHER ELEMENTS.
31
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 76 57 63 35 / 10 60 60 10
ATLANTA 75 54 59 35 / 10 70 50 10
BLAIRSVILLE 68 51 55 29 / 10 70 40 10
CARTERSVILLE 75 52 60 32 / 10 70 40 10
COLUMBUS 76 58 62 38 / 10 60 60 10
GAINESVILLE 72 54 62 34 / 10 70 50 10
MACON 78 62 65 36 / 10 50 60 20
ROME 75 52 61 32 / 10 70 40 10
PEACHTREE CITY 76 53 60 31 / 10 60 50 10
VIDALIA 81 64 69 42 / 10 40 60 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
26
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
828 AM CST THU FEB 23 2012
.UPDATE...STRONG WINDS ALOFT ARE MIXING TO THE SFC THIS MORNING
ACROSS NORTH CENTRAL NEBRASKA. SUSTAINED WINDS ARE NEARING 40 MPH
WITH GUSTS TO 55 MPH. HAVE UPGRADED THE WIND ADVISORY FOR POSSIBLE
SUSTAINED WINDS OVER 40 MPH WITH GUSTS TO 60 MPH.
&&
.PREV DISCUSSION... /ISSUED 747 AM CST THU FEB 23 2012/
UPDATE...
WIND IN NORTH CENTRAL NEBRASKA IS HIGHER THAN THE EARLIER
FORECAST INDICATED. ALSO...PROFILER DATA FROM THE WSR-88 AND THE
NETWORK SHOWS WIND 60KT OR GREATER AT 1000M AGL.
PREV DISCUSSION... /ISSUED 544 AM CST THU FEB 23 2012/
AVIATION...AS A STORM SYSTEM MAKES ITS WAY ACROSS NORTH CENTRAL
AND NORTHEAST NEBRASKA...CEILINGS AND VISIBILITY IN CENTRAL AND
SOUTHWEST NEBRASKA...INCLUDING MHN...OGA...IML...LBF AND BBW...ARE
EXPECTED TO BE AT OR ABOVE 3500 FEET AGL AND 5SM. IN NORTH CENTRAL
NEBRASKA...INCLUDING ONL...BUB...ANW...TIF AND VTN...PREVAILING
CONDITIONS ARE LIKELY TO LOWER TO 1000-2000 FEET AGL WITH 3-5SM
VISIBILITY IN LIGHT SNOW. OCCASIONAL REDUCTIONS TO 500-900 FEET
AGL AND LESS THAN 1SM ARE POSSIBLE IN SNOW AND BLOWING SNOW AS THE
PRECIPITATION AREA MOVES ACROSS NORTH CENTRAL NEBRASKA.
WIND WILL INCREASE BY 15Z OVER THE ENTIRE AREA WITH DIRECTION
310-340 AT 25-35G40-45KT. WIND IS EXPECTED TO SUBSIDE TO
20-25G30-35KT BY 22Z AND TO LESS THAN 15KT AFTER 00Z.
PREV DISCUSSION... /ISSUED 348 AM CST THU FEB 23 2012/
SHORT TERM...TODAY THROUGH SATURDAY
FORECAST FOCUS THROUGH THIS PERIOD IS ON WINDS AND SNOW POTENTIAL
TODAY.
AT 08Z...WATER VAPOR IMAGERY SHOWED A LARGE RIDGE OVER THE EASTERN
PACIFIC WITH TROUGHING ACROSS THE EASTERN HALF OF THE
CONUS...LEAVING THE CENTRAL STATES IN NORTHWEST FLOW. IN THIS
FLOW...A SHORTWAVE TROUGH WAS SEEN OVER SOUTHEAST IDAHO...WHILE
THE WAVE OF IMMEDIATE CONCERN FOR THE LOCAL AREA WAS OVER EASTERN
MONTANA INTO WESTERN NORTH DAKOTA AND NORTHWEST SOUTH DAKOTA. AT
THE SURFACE...THE COLD FRONT HAD PASSED ACROSS THE FORECAST AREA
AND WAS LOCATED FROM THE SURFACE LOW IN SOUTH CENTRAL SOUTH
DAKOTA THROUGH KONL TO KHDE TO KHLC THEN WEST INTO EAST CENTRAL
COLORADO. THE PRESSURE GRADIENT BEHIND THE FRONT WAS TIGHTENING
WITH WINDS ON THE INCREASE OVER WESTERN SOUTH DAKOTA AND THE
NEBRASKA PANHANDLE. TEMPERATURES REMAINED IN THE MID TO UPPER 30S
IN MOST LOCATIONS...HOWEVER LOOKING UPSTREAM BEHIND THE
FRONT...THINGS WERE BEGINNING TO SLOWLY COOL DOWN. LOOKING AT
RADAR...A LARGE VORTEX OF PRECIPITATION WAS SPINNING AROUND THE
700MB LOW OVER SOUTH DAKOTA. THE WESTERN PORTION OF THIS WAS OVER
THE BLACK HILLS AND THE WHOLE AREA WAS SLOWLY MOVING TO THE
SOUTHEAST. NOT MUCH WAS BEING REPORTED WITH THIS AREA OF
PRECIPITATION THOUGH...WITH JUST LIGHT SNOW WITH NO ACCUMULATIONS
YET AT KRAP.
THE LATEST RUC WOULD TAKE THE LOW OVER SOUTH DAKOTA SOUTHEAST
ACROSS NORTHEAST CHERRY AND KEYA PAHA COUNTIES THROUGH GARFIELD
AND WHEELER COUNTIES AND THEN CONTINUING SOUTHEAST ACROSS GID/S
FORECAST AREA. THE TIGHTEST PRESSURE GRADIENT SHOULD BE JUST TO
THE WEST OF THE LOW...SO THIS TRACK WOULD SUGGEST THE STRONGEST
WINDS WOULD BE ACROSS THE CENTRAL AND SOUTHEASTERN PARTS OF THE
FORECAST AREA THROUGH THE DAY. THERE REMAINS QUESTION OF HOW
STRONG THESE WINDS WILL BE. MAV GUIDANCE SEEMS TO BE TOO HIGH
GIVING 44KT SUSTAINED WINDS AT KBBW AND 41KT SUSTAINED AT KLBF.
SO ALTHOUGH EXPECTING HIGH WINDS...DIDN/T GO AS HIGH AS THAT
GUIDANCE. CURRENTLY THINKING TODAY/S WINDS WILL BE A HIGH END
ADVISORY...BUT WILL NEED TO KEEP AN EYE ON THINGS AS KRAP /WHICH
IS CURRENTLY JUST WEST OF THE LOW HAS HAD A PEAK GUST TO 54KTS
ALREADY. LUCKILY...WINDS ALOFT LOOK TO DECREASE THROUGH THE DAY AS
HIGHEST MIXING IS ACHIEVED AS TH 925MB AND 850MB WINDS FROM THE
KUNR VWP WERE AT 50KTS AND 55KTS RESPECTIVELY...WHILE BUFKIT
SOUNDINGS FROM THE NAM SHOWED UP TO 65KTS AROUND 800MB. AS THE
WINDS WERE ALREADY COMING UP...DID START THE WIND ADVISORY EARLY
/10Z FOR THE NORTHWEST TWO-THIRDS OF THE FORECAST AREA/ WITH THE
SOUTHEAST TIER BEGINNING NOW AT 14Z RATHER THAN 15Z. THE PRESSURE
GRADIENT WILL LESSEN THIS AFTERNOON...BUT WITH VERY STEEP LAPSE RATES
WITH THE COLD AIR ADVECTION INFLUENCING THE MIXING POTENTIAL...WILL
CONTINUE TO SEE BREEZY CONDITIONS THROUGH THE AFTERNOON.
IN TERMS OF THE SNOW...THE PRECIPITATION OVER THE BLACK HILLS
SHOULD ROTATE SOUTHEAST INTO NORTH CENTRAL NEBRASKA AND CONTINUE
TO THE SOUTHEAST TODAY. DON/T HAVE A GOOD HANDLE ON HOW MUCH QPF
WILL BE WITH THIS AS MODELS RANGE FROM A FEW HUNDREDTHS TO AROUND
A QUARTER INCH. BELIEVE THE LARGER AMOUNTS MAY BE A BIT HIGH DUE
TO WHAT IS CURRENTLY SEEN ON RADAR AND WITH ONLY A FEW STATIONS
REPORTING PRECIPITATION SO DIDN/T GO THAT ROBUST IN THE FORECAST.
CURRENTLY HAVE UP TO 2 INCHES OF SNOW ACCUMULATION THROUGH THE DAY
FROM MERRIMAN TO THEDFORD TO BROKEN BOW. DID KEEP THE
PRECIPITATION TYPE AS SNOW COLD AIR WILL CONTINUE TO PUSH SOUTH
KEEPING TEMPERATURES IN THESE AREAS FROM RISING MUCH AND WITH
TEMPERATURES ALOFT COOLING...PRECIPITATION WILL FALL AS
SNOW...WHILE IT MAY MELT UPON REACHING THE GROUND. ONE CONCERN
WILL BE IF THIS SNOW WILL HAVE ANY IMPACT DUE TO THE WINDS. EVEN
THOUGH IT WILL BE LIGHT SNOW SHOWERS...WINDS BLOWING AT 40 TO 50
MPH COULD CAUSE REDUCED VISIBILITIES. HELD OFF ON PUTTING OUT ANY
WINTER WEATHER HEADLINES BECAUSE OF THE LIGHTER SNOW AMOUNTS
EXPECTED BUT WILL PUT OUT A SPECIAL WEATHER STATEMENT TO INFORM
USERS OF POTENTIAL IMPACTS.
TEMPERATURES WILL STAY BELOW NORMAL FOR FRIDAY WITH HIGHS ONLY IN
THE MID 30S TO LOW 40S AS NORTHWEST FLOW STAYS IN PLACE KEEPING
THE COOLER AIR OVER THE AREA. LAPSE RATES WILL REMAIN STEEP DUE TO
THE COLDER AIR ALOFT AND AS A WEAK SHORTWAVE TROUGH PASSES ACROSS
THE AREA...MAY SEE SOME SCATTERED SNOW SHOWERS THROUGH THE DAY.
DON/T EXPECT ANYTHING WIDESPREAD OR MUCH FOR ACCUMULATIONS...BUT
FELT IT DEEMED ADDING IN A SLIGHT CHANCE.
RIDGING BUILDS IN FOR SATURDAY...AND WITH MODELS SHOWING ABUNDANT
DRY AIR...SHOULD SEE QUITE A BIT OF SUNSHINE. TEMPERATURES WILL
WARM AS SOUTHERLY SURFACE FLOW BRINGS WARMER AIR NORTHWARD SO
LOOKING AT TEMPERATURES RISING TO ABOVE NORMAL VALUES WHICH ARE LOW
TO MID 40S.
LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
STILL LOOKS LIKE A RATHER SIGNIFICANT SYSTEM WILL PASS ACROSS THE
NORTHERN PLAINS ON SUNDAY. THE TREND SINCE YESTERDAY DOES LOOK TO
BE A BIT TO THE NORTH WITH THE UPPER LEVEL SYSTEM SO THE MAJORITY
OF THE SNOW WILL FALL ACROSS THE DAKOTAS. THE OPERATIONAL GFS
SOLUTION IS ONE OF THE MORE SOUTHERLY SOLUTIONS OF THE ENSEMBLE
MEMBERS...WITH THE MEAN BEING CLOSER TO THE ECMWF. BUT TO LEAVE A
CHANCE FOR A SOUTHERLY SHIFT...SLIGHT CHANCES FOR SNOW LOOK TO BE
GOOD FOR SUNDAY AND SUNDAY NIGHT ACROSS NORTHERN NEBRASKA. THE
SURFACE LOW IS NOW LOOKING LIKE IT WILL MOVE ACROSS SOUTH
DAKOTA...WITH THE COLD FRONT QUICKLY MOVING ACROSS THE FORECAST
AREA BY MID MORNING ON SUNDAY. LOOKS LIKE BREEZY NORTHWEST WINDS
ACROSS NEBRASKA...WITH THE MORE ROBUST WINDS JUST TO THE WEST OF
THE LOW OVER THE DAKOTAS WHERE THE PRESSURE GRADIENT WILL BE
TIGHTEST. ALSO...WITH THE NORTHERLY SHIFT...TEMPERATURES MAY STAY
A BIT WARMER ON SUNDAY. STILL EXPECTING BELOW NORMAL FOR
HIGHS...BUT WITH THIS TRACK...WOULD EXPECT HIGHS IN THE MID 30S TO
MID 40S RATHER THAN MID 20S TO 40 DEGREES AS IT LOOKS TO THE
NORTH. HIGH PRESSURE BUILDS SOUTH FOR MONDAY...WITH DRY
CONDITIONS...BUT COLDER AS 850MB TEMPERATURES STAY BELOW 0C ACROSS
THE ENTIRE FORECAST AREA. THE GFS HAS 850MB TEMPERATURES OVER
NORTHERN NEBRASKA AT -7C TO -9C. MEANWHILE...ANOTHER SYSTEM LOOKS
TO DIG TOWARDS THE FOUR CORNERS WITH A SURFACE LOW DEVELOPING
OVER NEW MEXICO MONDAY NIGHT. THE WARM FRONT WITH THIS SYSTEM IS
CURRENTLY PROJECTED TO LIFT INTO KANSAS MONDAY NIGHT...WITH
MOISTURE AND LIFT OVERRUNNING THE FRONT BRINGING PRECIPITATION
INTO NEBRASKA. THE GFS BREAKS THIS PRECIPITATION OUT BY 06Z WHILE
THE ECMWF IS SLIGHTLY DELAYED. SURFACE FEATURES ARE FAIRLY
SIMILAR...BUT THE UPPER LEVEL TROUGH IS MUCH MORE AMPLIFIED AND
POSITIVELY TILTED. THE ECMWF DOES SHOW STRONG ISENTROPIC LIFT IN
THE 285K TO 295K SURFACES...AS WELL AS GOOD MOISTURE TRANSPORT
INTO SOUTHWEST NEBRASKA ON THE 285K SURFACE. SO WHEREVER THE
SYSTEM TRACKS...THERE IS CERTAINLY POTENTIAL FOR SOME DECENT
PRECIPITATION. AT THIS POINT WILL STICK TO THE CONSENSUS OUTPUT AS
PLENTY CAN CHANGE WITH THIS SYSTEM OVER THE NEXT WEEK.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY UNTIL 6 PM CST
/5 PM MST/ THIS EVENING FOR
NEZ004-007-009-010-022-023-027>029-035-036-056>059-069>071.
HIGH WIND WARNING UNTIL 6 PM CST /5 PM MST/ THIS EVENING FOR
NEZ005-006-008-024>026-037-038-094.
&&
$$
DISCUSSION...BROOKS
UPDATE...TAYLOR
AVIATION...TAYLOR
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
747 AM CST THU FEB 23 2012
.UPDATE...
WIND IN NORTH CENTRAL NEBRASKA IS HIGHER THAN THE EARLIER
FORECAST INDICATED. ALSO...PROFILER DATA FROM THE WSR-88 AND THE
NETWORK SHOWS WIND 60KT OR GREATER AT 1000M AGL.
&&
.PREV DISCUSSION... /ISSUED 544 AM CST THU FEB 23 2012/
AVIATION...
AS A STORM SYSTEM MAKES ITS WAY ACROSS NORTH CENTRAL AND
NORTHEAST NEBRASKA...CEILINGS AND VISIBILITY IN CENTRAL AND
SOUTHWEST NEBRASKA...INCLUDING MHN...OGA...IML...LBF AND BBW...ARE
EXPECTED TO BE AT OR ABOVE 3500 FEET AGL AND 5SM. IN NORTH CENTRAL
NEBRASKA...INCLUDING ONL...BUB...ANW...TIF AND VTN...PREVAILING
CONDITIONS ARE LIKELY TO LOWER TO 1000-2000 FEET AGL WITH 3-5SM
VISIBILITY IN LIGHT SNOW. OCCASIONAL REDUCTIONS TO 500-900 FEET AGL
AND LESS THAN 1SM ARE POSSIBLE IN SNOW AND BLOWING SNOW AS THE
PRECIPITATION AREA MOVES ACROSS NORTH CENTRAL NEBRASKA.
WIND WILL INCREASE BY 15Z OVER THE ENTIRE AREA WITH DIRECTION
310-340 AT 25-35G40-45KT. WIND IS EXPECTED TO SUBSIDE TO
20-25G30-35KT BY 22Z AND TO LESS THAN 15KT AFTER 00Z.
PREV DISCUSSION... /ISSUED 348 AM CST THU FEB 23 2012/
SHORT TERM...TODAY THROUGH SATURDAY
FORECAST FOCUS THROUGH THIS PERIOD IS ON WINDS AND SNOW POTENTIAL
TODAY.
AT 08Z...WATER VAPOR IMAGERY SHOWED A LARGE RIDGE OVER THE EASTERN
PACIFIC WITH TROUGHING ACROSS THE EASTERN HALF OF THE
CONUS...LEAVING THE CENTRAL STATES IN NORTHWEST FLOW. IN THIS
FLOW...A SHORTWAVE TROUGH WAS SEEN OVER SOUTHEAST IDAHO...WHILE
THE WAVE OF IMMEDIATE CONCERN FOR THE LOCAL AREA WAS OVER EASTERN
MONTANA INTO WESTERN NORTH DAKOTA AND NORTHWEST SOUTH DAKOTA. AT
THE SURFACE...THE COLD FRONT HAD PASSED ACROSS THE FORECAST AREA
AND WAS LOCATED FROM THE SURFACE LOW IN SOUTH CENTRAL SOUTH
DAKOTA THROUGH KONL TO KHDE TO KHLC THEN WEST INTO EAST CENTRAL
COLORADO. THE PRESSURE GRADIENT BEHIND THE FRONT WAS TIGHTENING
WITH WINDS ON THE INCREASE OVER WESTERN SOUTH DAKOTA AND THE
NEBRASKA PANHANDLE. TEMPERATURES REMAINED IN THE MID TO UPPER 30S
IN MOST LOCATIONS...HOWEVER LOOKING UPSTREAM BEHIND THE
FRONT...THINGS WERE BEGINNING TO SLOWLY COOL DOWN. LOOKING AT
RADAR...A LARGE VORTEX OF PRECIPITATION WAS SPINNING AROUND THE
700MB LOW OVER SOUTH DAKOTA. THE WESTERN PORTION OF THIS WAS OVER
THE BLACK HILLS AND THE WHOLE AREA WAS SLOWLY MOVING TO THE
SOUTHEAST. NOT MUCH WAS BEING REPORTED WITH THIS AREA OF
PRECIPITATION THOUGH...WITH JUST LIGHT SNOW WITH NO ACCUMULATIONS
YET AT KRAP.
THE LATEST RUC WOULD TAKE THE LOW OVER SOUTH DAKOTA SOUTHEAST
ACROSS NORTHEAST CHERRY AND KEYA PAHA COUNTIES THROUGH GARFIELD
AND WHEELER COUNTIES AND THEN CONTINUING SOUTHEAST ACROSS GID/S
FORECAST AREA. THE TIGHTEST PRESSURE GRADIENT SHOULD BE JUST TO
THE WEST OF THE LOW...SO THIS TRACK WOULD SUGGEST THE STRONGEST
WINDS WOULD BE ACROSS THE CENTRAL AND SOUTHEASTERN PARTS OF THE
FORECAST AREA THROUGH THE DAY. THERE REMAINS QUESTION OF HOW
STRONG THESE WINDS WILL BE. MAV GUIDANCE SEEMS TO BE TOO HIGH
GIVING 44KT SUSTAINED WINDS AT KBBW AND 41KT SUSTAINED AT KLBF.
SO ALTHOUGH EXPECTING HIGH WINDS...DIDN/T GO AS HIGH AS THAT
GUIDANCE. CURRENTLY THINKING TODAY/S WINDS WILL BE A HIGH END
ADVISORY...BUT WILL NEED TO KEEP AN EYE ON THINGS AS KRAP /WHICH
IS CURRENTLY JUST WEST OF THE LOW HAS HAD A PEAK GUST TO 54KTS
ALREADY. LUCKILY...WINDS ALOFT LOOK TO DECREASE THROUGH THE DAY AS
HIGHEST MIXING IS ACHIEVED AS TH 925MB AND 850MB WINDS FROM THE
KUNR VWP WERE AT 50KTS AND 55KTS RESPECTIVELY...WHILE BUFKIT
SOUNDINGS FROM THE NAM SHOWED UP TO 65KTS AROUND 800MB. AS THE
WINDS WERE ALREADY COMING UP...DID START THE WIND ADVISORY EARLY
/10Z FOR THE NORTHWEST TWO-THIRDS OF THE FORECAST AREA/ WITH THE
SOUTHEAST TIER BEGINNING NOW AT 14Z RATHER THAN 15Z. THE PRESSURE
GRADIENT WILL LESSEN THIS AFTERNOON...BUT WITH VERY STEEP LAPSE RATES
WITH THE COLD AIR ADVECTION INFLUENCING THE MIXING POTENTIAL...WILL
CONTINUE TO SEE BREEZY CONDITIONS THROUGH THE AFTERNOON.
IN TERMS OF THE SNOW...THE PRECIPITATION OVER THE BLACK HILLS
SHOULD ROTATE SOUTHEAST INTO NORTH CENTRAL NEBRASKA AND CONTINUE
TO THE SOUTHEAST TODAY. DON/T HAVE A GOOD HANDLE ON HOW MUCH QPF
WILL BE WITH THIS AS MODELS RANGE FROM A FEW HUNDREDTHS TO AROUND
A QUARTER INCH. BELIEVE THE LARGER AMOUNTS MAY BE A BIT HIGH DUE
TO WHAT IS CURRENTLY SEEN ON RADAR AND WITH ONLY A FEW STATIONS
REPORTING PRECIPITATION SO DIDN/T GO THAT ROBUST IN THE FORECAST.
CURRENTLY HAVE UP TO 2 INCHES OF SNOW ACCUMULATION THROUGH THE DAY
FROM MERRIMAN TO THEDFORD TO BROKEN BOW. DID KEEP THE
PRECIPITATION TYPE AS SNOW COLD AIR WILL CONTINUE TO PUSH SOUTH
KEEPING TEMPERATURES IN THESE AREAS FROM RISING MUCH AND WITH
TEMPERATURES ALOFT COOLING...PRECIPITATION WILL FALL AS
SNOW...WHILE IT MAY MELT UPON REACHING THE GROUND. ONE CONCERN
WILL BE IF THIS SNOW WILL HAVE ANY IMPACT DUE TO THE WINDS. EVEN
THOUGH IT WILL BE LIGHT SNOW SHOWERS...WINDS BLOWING AT 40 TO 50
MPH COULD CAUSE REDUCED VISIBILITIES. HELD OFF ON PUTTING OUT ANY
WINTER WEATHER HEADLINES BECAUSE OF THE LIGHTER SNOW AMOUNTS
EXPECTED BUT WILL PUT OUT A SPECIAL WEATHER STATEMENT TO INFORM
USERS OF POTENTIAL IMPACTS.
TEMPERATURES WILL STAY BELOW NORMAL FOR FRIDAY WITH HIGHS ONLY IN
THE MID 30S TO LOW 40S AS NORTHWEST FLOW STAYS IN PLACE KEEPING
THE COOLER AIR OVER THE AREA. LAPSE RATES WILL REMAIN STEEP DUE TO
THE COLDER AIR ALOFT AND AS A WEAK SHORTWAVE TROUGH PASSES ACROSS
THE AREA...MAY SEE SOME SCATTERED SNOW SHOWERS THROUGH THE DAY.
DON/T EXPECT ANYTHING WIDESPREAD OR MUCH FOR ACCUMULATIONS...BUT
FELT IT DEEMED ADDING IN A SLIGHT CHANCE.
RIDGING BUILDS IN FOR SATURDAY...AND WITH MODELS SHOWING ABUNDANT
DRY AIR...SHOULD SEE QUITE A BIT OF SUNSHINE. TEMPERATURES WILL
WARM AS SOUTHERLY SURFACE FLOW BRINGS WARMER AIR NORTHWARD SO
LOOKING AT TEMPERATURES RISING TO ABOVE NORMAL VALUES WHICH ARE LOW
TO MID 40S.
LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
STILL LOOKS LIKE A RATHER SIGNIFICANT SYSTEM WILL PASS ACROSS THE
NORTHERN PLAINS ON SUNDAY. THE TREND SINCE YESTERDAY DOES LOOK TO
BE A BIT TO THE NORTH WITH THE UPPER LEVEL SYSTEM SO THE MAJORITY
OF THE SNOW WILL FALL ACROSS THE DAKOTAS. THE OPERATIONAL GFS
SOLUTION IS ONE OF THE MORE SOUTHERLY SOLUTIONS OF THE ENSEMBLE
MEMBERS...WITH THE MEAN BEING CLOSER TO THE ECMWF. BUT TO LEAVE A
CHANCE FOR A SOUTHERLY SHIFT...SLIGHT CHANCES FOR SNOW LOOK TO BE
GOOD FOR SUNDAY AND SUNDAY NIGHT ACROSS NORTHERN NEBRASKA. THE
SURFACE LOW IS NOW LOOKING LIKE IT WILL MOVE ACROSS SOUTH
DAKOTA...WITH THE COLD FRONT QUICKLY MOVING ACROSS THE FORECAST
AREA BY MID MORNING ON SUNDAY. LOOKS LIKE BREEZY NORTHWEST WINDS
ACROSS NEBRASKA...WITH THE MORE ROBUST WINDS JUST TO THE WEST OF
THE LOW OVER THE DAKOTAS WHERE THE PRESSURE GRADIENT WILL BE
TIGHTEST. ALSO...WITH THE NORTHERLY SHIFT...TEMPERATURES MAY STAY
A BIT WARMER ON SUNDAY. STILL EXPECTING BELOW NORMAL FOR
HIGHS...BUT WITH THIS TRACK...WOULD EXPECT HIGHS IN THE MID 30S TO
MID 40S RATHER THAN MID 20S TO 40 DEGREES AS IT LOOKS TO THE
NORTH. HIGH PRESSURE BUILDS SOUTH FOR MONDAY...WITH DRY
CONDITIONS...BUT COLDER AS 850MB TEMPERATURES STAY BELOW 0C ACROSS
THE ENTIRE FORECAST AREA. THE GFS HAS 850MB TEMPERATURES OVER
NORTHERN NEBRASKA AT -7C TO -9C. MEANWHILE...ANOTHER SYSTEM LOOKS
TO DIG TOWARDS THE FOUR CORNERS WITH A SURFACE LOW DEVELOPING
OVER NEW MEXICO MONDAY NIGHT. THE WARM FRONT WITH THIS SYSTEM IS
CURRENTLY PROJECTED TO LIFT INTO KANSAS MONDAY NIGHT...WITH
MOISTURE AND LIFT OVERRUNNING THE FRONT BRINGING PRECIPITATION
INTO NEBRASKA. THE GFS BREAKS THIS PRECIPITATION OUT BY 06Z WHILE
THE ECMWF IS SLIGHTLY DELAYED. SURFACE FEATURES ARE FAIRLY
SIMILAR...BUT THE UPPER LEVEL TROUGH IS MUCH MORE AMPLIFIED AND
POSITIVELY TILTED. THE ECMWF DOES SHOW STRONG ISENTROPIC LIFT IN
THE 285K TO 295K SURFACES...AS WELL AS GOOD MOISTURE TRANSPORT
INTO SOUTHWEST NEBRASKA ON THE 285K SURFACE. SO WHEREVER THE
SYSTEM TRACKS...THERE IS CERTAINLY POTENTIAL FOR SOME DECENT
PRECIPITATION. AT THIS POINT WILL STICK TO THE CONSENSUS OUTPUT AS
PLENTY CAN CHANGE WITH THIS SYSTEM OVER THE NEXT WEEK.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM CST /5 PM MST/ THIS EVENING
FOR NEZ004>010-022>029-035>038-056>059069>071-094
&&
$$
SHORT TERM UPDATE...SPRINGER
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
544 AM CST THU FEB 23 2012
.AVIATION...
AS A STORM SYSTEM MAKES ITS WAY ACROSS NORTH CENTRAL AND
NORTHEAST NEBRASKA...CEILINGS AND VISIBILITY IN CENTRAL AND
SOUTHWEST NEBRASKA...INCLUDING MHN...OGA...IML...LBF AND BBW...ARE
EXPECTED TO BE AT OR ABOVE 3500 FEET AGL AND 5SM. IN NORTH CENTRAL
NEBRASKA...INCLUDING ONL...BUB...ANW...TIF AND VTN...PREVAILING
CONDITIONS ARE LIKELY TO LOWER TO 1000-2000 FEET AGL WITH 3-5SM
VISIBILITY IN LIGHT SNOW. OCCASIONAL REDUCTIONS TO 500-900 FEET AGL
AND LESS THAN 1SM ARE POSSIBLE IN SNOW AND BLOWING SNOW AS THE
PRECIPITATION AREA MOVES ACROSS NORTH CENTRAL NEBRASKA.
WIND WILL INCREASE BY 15Z OVER THE ENTIRE AREA WITH DIRECTION
310-340 AT 25-35G40-45KT. WIND IS EXPECTED TO SUBSIDE TO
20-25G30-35KT BY 22Z AND TO LESS THAN 15KT AFTER 00Z.
&&
.PREV DISCUSSION... /ISSUED 348 AM CST THU FEB 23 2012/
SHORT TERM...TODAY THROUGH SATURDAY
FORECAST FOCUS THROUGH THIS PERIOD IS ON WINDS AND SNOW POTENTIAL
TODAY.
AT 08Z...WATER VAPOR IMAGERY SHOWED A LARGE RIDGE OVER THE EASTERN
PACIFIC WITH TROUGHING ACROSS THE EASTERN HALF OF THE
CONUS...LEAVING THE CENTRAL STATES IN NORTHWEST FLOW. IN THIS
FLOW...A SHORTWAVE TROUGH WAS SEEN OVER SOUTHEAST IDAHO...WHILE
THE WAVE OF IMMEDIATE CONCERN FOR THE LOCAL AREA WAS OVER EASTERN
MONTANA INTO WESTERN NORTH DAKOTA AND NORTHWEST SOUTH DAKOTA. AT
THE SURFACE...THE COLD FRONT HAD PASSED ACROSS THE FORECAST AREA
AND WAS LOCATED FROM THE SURFACE LOW IN SOUTH CENTRAL SOUTH
DAKOTA THROUGH KONL TO KHDE TO KHLC THEN WEST INTO EAST CENTRAL
COLORADO. THE PRESSURE GRADIENT BEHIND THE FRONT WAS TIGHTENING
WITH WINDS ON THE INCREASE OVER WESTERN SOUTH DAKOTA AND THE
NEBRASKA PANHANDLE. TEMPERATURES REMAINED IN THE MID TO UPPER 30S
IN MOST LOCATIONS...HOWEVER LOOKING UPSTREAM BEHIND THE
FRONT...THINGS WERE BEGINNING TO SLOWLY COOL DOWN. LOOKING AT
RADAR...A LARGE VORTEX OF PRECIPITATION WAS SPINNING AROUND THE
700MB LOW OVER SOUTH DAKOTA. THE WESTERN PORTION OF THIS WAS OVER
THE BLACK HILLS AND THE WHOLE AREA WAS SLOWLY MOVING TO THE
SOUTHEAST. NOT MUCH WAS BEING REPORTED WITH THIS AREA OF
PRECIPITATION THOUGH...WITH JUST LIGHT SNOW WITH NO ACCUMULATIONS
YET AT KRAP.
THE LATEST RUC WOULD TAKE THE LOW OVER SOUTH DAKOTA SOUTHEAST
ACROSS NORTHEAST CHERRY AND KEYA PAHA COUNTIES THROUGH GARFIELD
AND WHEELER COUNTIES AND THEN CONTINUING SOUTHEAST ACROSS GID/S
FORECAST AREA. THE TIGHTEST PRESSURE GRADIENT SHOULD BE JUST TO
THE WEST OF THE LOW...SO THIS TRACK WOULD SUGGEST THE STRONGEST
WINDS WOULD BE ACROSS THE CENTRAL AND SOUTHEASTERN PARTS OF THE
FORECAST AREA THROUGH THE DAY. THERE REMAINS QUESTION OF HOW
STRONG THESE WINDS WILL BE. MAV GUIDANCE SEEMS TO BE TOO HIGH
GIVING 44KT SUSTAINED WINDS AT KBBW AND 41KT SUSTAINED AT KLBF.
SO ALTHOUGH EXPECTING HIGH WINDS...DIDN/T GO AS HIGH AS THAT
GUIDANCE. CURRENTLY THINKING TODAY/S WINDS WILL BE A HIGH END
ADVISORY...BUT WILL NEED TO KEEP AN EYE ON THINGS AS KRAP /WHICH
IS CURRENTLY JUST WEST OF THE LOW HAS HAD A PEAK GUST TO 54KTS
ALREADY. LUCKILY...WINDS ALOFT LOOK TO DECREASE THROUGH THE DAY AS
HIGHEST MIXING IS ACHIEVED AS TH 925MB AND 850MB WINDS FROM THE
KUNR VWP WERE AT 50KTS AND 55KTS RESPECTIVELY...WHILE BUFKIT
SOUNDINGS FROM THE NAM SHOWED UP TO 65KTS AROUND 800MB. AS THE
WINDS WERE ALREADY COMING UP...DID START THE WIND ADVISORY EARLY
/10Z FOR THE NORTHWEST TWO-THIRDS OF THE FORECAST AREA/ WITH THE
SOUTHEAST TIER BEGINNING NOW AT 14Z RATHER THAN 15Z. THE PRESSURE
GRADIENT WILL LESSEN THIS AFTERNOON...BUT WITH VERY STEEP LAPSE RATES
WITH THE COLD AIR ADVECTION INFLUENCING THE MIXING POTENTIAL...WILL
CONTINUE TO SEE BREEZY CONDITIONS THROUGH THE AFTERNOON.
IN TERMS OF THE SNOW...THE PRECIPITATION OVER THE BLACK HILLS
SHOULD ROTATE SOUTHEAST INTO NORTH CENTRAL NEBRASKA AND CONTINUE
TO THE SOUTHEAST TODAY. DON/T HAVE A GOOD HANDLE ON HOW MUCH QPF
WILL BE WITH THIS AS MODELS RANGE FROM A FEW HUNDREDTHS TO AROUND
A QUARTER INCH. BELIEVE THE LARGER AMOUNTS MAY BE A BIT HIGH DUE
TO WHAT IS CURRENTLY SEEN ON RADAR AND WITH ONLY A FEW STATIONS
REPORTING PRECIPITATION SO DIDN/T GO THAT ROBUST IN THE FORECAST.
CURRENTLY HAVE UP TO 2 INCHES OF SNOW ACCUMULATION THROUGH THE DAY
FROM MERRIMAN TO THEDFORD TO BROKEN BOW. DID KEEP THE
PRECIPITATION TYPE AS SNOW COLD AIR WILL CONTINUE TO PUSH SOUTH
KEEPING TEMPERATURES IN THESE AREAS FROM RISING MUCH AND WITH
TEMPERATURES ALOFT COOLING...PRECIPITATION WILL FALL AS
SNOW...WHILE IT MAY MELT UPON REACHING THE GROUND. ONE CONCERN
WILL BE IF THIS SNOW WILL HAVE ANY IMPACT DUE TO THE WINDS. EVEN
THOUGH IT WILL BE LIGHT SNOW SHOWERS...WINDS BLOWING AT 40 TO 50
MPH COULD CAUSE REDUCED VISIBILITIES. HELD OFF ON PUTTING OUT ANY
WINTER WEATHER HEADLINES BECAUSE OF THE LIGHTER SNOW AMOUNTS
EXPECTED BUT WILL PUT OUT A SPECIAL WEATHER STATEMENT TO INFORM
USERS OF POTENTIAL IMPACTS.
TEMPERATURES WILL STAY BELOW NORMAL FOR FRIDAY WITH HIGHS ONLY IN
THE MID 30S TO LOW 40S AS NORTHWEST FLOW STAYS IN PLACE KEEPING
THE COOLER AIR OVER THE AREA. LAPSE RATES WILL REMAIN STEEP DUE TO
THE COLDER AIR ALOFT AND AS A WEAK SHORTWAVE TROUGH PASSES ACROSS
THE AREA...MAY SEE SOME SCATTERED SNOW SHOWERS THROUGH THE DAY.
DON/T EXPECT ANYTHING WIDESPREAD OR MUCH FOR ACCUMULATIONS...BUT
FELT IT DEEMED ADDING IN A SLIGHT CHANCE.
RIDGING BUILDS IN FOR SATURDAY...AND WITH MODELS SHOWING ABUNDANT
DRY AIR...SHOULD SEE QUITE A BIT OF SUNSHINE. TEMPERATURES WILL
WARM AS SOUTHERLY SURFACE FLOW BRINGS WARMER AIR NORTHWARD SO
LOOKING AT TEMPERATURES RISING TO ABOVE NORMAL VALUES WHICH ARE LOW
TO MID 40S.
LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
STILL LOOKS LIKE A RATHER SIGNIFICANT SYSTEM WILL PASS ACROSS THE
NORTHERN PLAINS ON SUNDAY. THE TREND SINCE YESTERDAY DOES LOOK TO
BE A BIT TO THE NORTH WITH THE UPPER LEVEL SYSTEM SO THE MAJORITY
OF THE SNOW WILL FALL ACROSS THE DAKOTAS. THE OPERATIONAL GFS
SOLUTION IS ONE OF THE MORE SOUTHERLY SOLUTIONS OF THE ENSEMBLE
MEMBERS...WITH THE MEAN BEING CLOSER TO THE ECMWF. BUT TO LEAVE A
CHANCE FOR A SOUTHERLY SHIFT...SLIGHT CHANCES FOR SNOW LOOK TO BE
GOOD FOR SUNDAY AND SUNDAY NIGHT ACROSS NORTHERN NEBRASKA. THE
SURFACE LOW IS NOW LOOKING LIKE IT WILL MOVE ACROSS SOUTH
DAKOTA...WITH THE COLD FRONT QUICKLY MOVING ACROSS THE FORECAST
AREA BY MID MORNING ON SUNDAY. LOOKS LIKE BREEZY NORTHWEST WINDS
ACROSS NEBRASKA...WITH THE MORE ROBUST WINDS JUST TO THE WEST OF
THE LOW OVER THE DAKOTAS WHERE THE PRESSURE GRADIENT WILL BE
TIGHTEST. ALSO...WITH THE NORTHERLY SHIFT...TEMPERATURES MAY STAY
A BIT WARMER ON SUNDAY. STILL EXPECTING BELOW NORMAL FOR
HIGHS...BUT WITH THIS TRACK...WOULD EXPECT HIGHS IN THE MID 30S TO
MID 40S RATHER THAN MID 20S TO 40 DEGREES AS IT LOOKS TO THE
NORTH. HIGH PRESSURE BUILDS SOUTH FOR MONDAY...WITH DRY
CONDITIONS...BUT COLDER AS 850MB TEMPERATURES STAY BELOW 0C ACROSS
THE ENTIRE FORECAST AREA. THE GFS HAS 850MB TEMPERATURES OVER
NORTHERN NEBRASKA AT -7C TO -9C. MEANWHILE...ANOTHER SYSTEM LOOKS
TO DIG TOWARDS THE FOUR CORNERS WITH A SURFACE LOW DEVELOPING
OVER NEW MEXICO MONDAY NIGHT. THE WARM FRONT WITH THIS SYSTEM IS
CURRENTLY PROJECTED TO LIFT INTO KANSAS MONDAY NIGHT...WITH
MOISTURE AND LIFT OVERRUNNING THE FRONT BRINGING PRECIPITATION
INTO NEBRASKA. THE GFS BREAKS THIS PRECIPITATION OUT BY 06Z WHILE
THE ECMWF IS SLIGHTLY DELAYED. SURFACE FEATURES ARE FAIRLY
SIMILAR...BUT THE UPPER LEVEL TROUGH IS MUCH MORE AMPLIFIED AND
POSITIVELY TILTED. THE ECMWF DOES SHOW STRONG ISENTROPIC LIFT IN
THE 285K TO 295K SURFACES...AS WELL AS GOOD MOISTURE TRANSPORT
INTO SOUTHWEST NEBRASKA ON THE 285K SURFACE. SO WHEREVER THE
SYSTEM TRACKS...THERE IS CERTAINLY POTENTIAL FOR SOME DECENT
PRECIPITATION. AT THIS POINT WILL STICK TO THE CONSENSUS OUTPUT AS
PLENTY CAN CHANGE WITH THIS SYSTEM OVER THE NEXT WEEK.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM CST /5 PM MST/ THIS EVENING FOR
NEZ004>010-022>029-035>038-056>059-069>071-094.
&&
$$
SHORT TERM/EXTENDED...BROOKS
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
622 AM EST THU FEB 23 2012
.SYNOPSIS...
WARM TEMPERATURES WILL PREVAIL OVER THE NEXT FEW DAYS AHEAD OF AN
APPROACHING COLD FRONT. SHOWERS AND A FEW STRONG THUNDERSTORMS ARE
POSSIBLE FRIDAY AS THE COLD FRONT PUSHES ACROSS THE REGION. DRY
AND COOLER AIR WILL OVERSPREAD THE EASTERN CAROLINAS THIS WEEKEND.
TEMPERATURES WILL REBOUND EARLY NEXT WEEK AS HIGH PRESSURE MOVES
OFFSHORE AND ALLOWS MILD SOUTHERLY WINDS TO SPREAD ACROSS THE
AREA.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 400 AM THURSDAY...CONVECTION HAVING APPROACHED FROM THE WEST
HAS DWINDLED AWAY EARLY THIS MORNING...WITH HRRR HAVING INDICATED
THAT THIS WOULD TAKE PLACE. LOW LEVEL MOISTURE AND A SCREAMING LOW
LEVEL JET 50+ KT AT 925 MB...WILL RESULT IN SCT/BKN LOW STRATUS
EARLY THIS MORNING. BY MID MORNING THE STRATUS DECK WILL DISSIPATE
AS THE JET DIMINISHES AND WITH THE DAYS INSOLATION HAVING COMMENCED.
A WEAK MID LEVEL S/W TROF ACCOMPANIED WITH CONVECTION AND MOVING
ACROSS THE APPALACHIAN MOUNTAINS...SHOULD EITHER PASS JUST NORTH OF
THE ILM CWA OR DISSIPATE AS IT TRACKS DOWN THE LEEWARD SIDE OF THE
MOUNTAINS. AS A RESULT HAVE KEPT POPS OUT OF THE FORECAST TODAY INTO
THIS EVENING. MODELS IN GOOD AGREEMENT WITH A SFC LOW AND ITS POTENT
UPPER S/W TROF EMERGING FROM THE ROCKY MOUNTAINS TODAY...THEN RACING
TO THE OHIO RIVER VALLEY BY EARLY THIS EVENING...AND REACHING LAKE
ERIE BY DAYBREAK FRIDAY. THE ASSOCIATED STRONG COLD FRONT....WILL BE
ON THE DOORSTEPS OF THE ILM CWA COME FRIDAY MORNING...IN ACTUALITY
LYING ACROSS THE CENTRAL CAROLINAS. AHEAD OF THE FRONT...EXCELLENT
WARM AIR ADVECTION TO OCCUR ACROSS THE FA AS EVIDENCED BY MODELS
INCREASING 8H TEMPS TO 14 TO 17 DEGREES CELSIUS BY EARLY FRIDAY
MORNING...WITH 1K-8H PARTIAL THICKNESSES REACHING 1392 TONIGHT. AND
THEY CALL THIS FEBRUARY? WITH THIS SAID...HAVE TWEAKED TODAYS MAX
TEMPS UPWARD BY A DEGREE OR 3...WITH A FEW LOCATIONS BREAKING THE 80
DEGREE MARK. WINDS WILL BE WSW IN THE MORNING...BACKING TO SW OR SSW
THIS AFTERNOON ALONG THE COAST WHICH WILL LIMIT MAX TEMPS TO THE
70-75 DEGREE RANGE BEFORE FALLING BACK INTO THE 60S THIS AFTERNOON
DUE TO ADJACENT SSTS IN THE 50S. A MILD EARLY MAY NITE PROGGED FOR
TONIGHT...HOWEVER THE CALENDER STATES ITS STILL FEBRUARY. LOOK FOR
LOWS IN THE 60S WITH SOME 50S ALONG THE IMMEDIATE COAST. POPS WILL
BEGIN TO RAMP UP TOWARDS DAYBREAK AS THE SFC COLD FRONT APPROACHES.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...MODELS HAVE TURNED MUCH DRIER WITH FRIDAY`S
DYNAMIC FROPA. WHILE GIVEN THE STRENGTH OF THE LOW LEVEL FORCING IT
SEEMS HARD TO GO AS DRY AS SAY THE WRF...WITH 00 RAINFALL IT DOES
APPEAR THAT FOR THE MOST PART RAINFALL AMOUNTS WILL DISAPPOINT
(GIVEN THE DROUGHT). LIKELY POPS WILL BE MAINTAINED SINCE ALTHOUGH
SIGNIFICANT RAINFALL MAY BE HARD TO COME BY MEASURABLE RAINFALL
SHOULD NOT. LOW LEVEL WIND FIELDS NOT AS STRONG AS PREV GUIDANCE SO
SEVERE THREAT SEEMS LESSENED BUT STILL CERTAINLY NON-ZERO. `SEVERE
SHOWERS` A LIKELY THREAT DUE TO LOW LEVEL WIND SPEED/STORM
MOTION/LACK OF INSTABILITY. STRONG CAA FRIDAY NIGHT INTO SATURDAY TO
BRING SLIGHTLY BELOW CLIMO TEMPS FOR THE REST OF THE PERIOD WHILE
SKY CLEARS OUT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 3 AM THURSDAY...PROGRESSIVE FLOW IN PLACE AT THE START OF THE
PERIOD WITH ZONAL MID LEVEL FLOW QUICKLY SPREADING ACROSS THE
SOUTHEAST. LARGE AREA OF SURFACE HIGH PRESSURE WILL ALSO BE NEARING
THE COAST MAKING SUNDAY ONE LAST DAY OF NEAR TO SLIGHTLY BLOW CLIMO
TEMPS. THIS HIGH WILL END UP OFFSHORE BY MONDAY LEADING TO MILDER
WEATHER AND THE RETURN FLOW OF SOME MOISTURE. THIS MAY EITHER SIMPLY
TAKE THE FORM OF SOME CLOUDINESS OR SOME LOW RAIN CHANCES SHOULD A
COASTAL TROUGH DEVELOP AS INDICATED BY SOME MODELS. HIGH PRESSURE
WILL SIMILARLY BE FOUND WELL OFF THE COAST ON TUESDAY WHILE A COLD
FRONT LIES ALIGNED WITH THE ZONAL FLOW SOMEWHERE NEAR THE
MASON-DIXON LINE. WHILE RAIN CHANCES REMAIN TOUGH TO RULE OUT THERE
STILL REALLY ISNT MUCH FOR A TRIGGERING MECHANISM ESPECIALLY GIVEN
THE BROAD UPPER HIGH OVER THE GOMEX/CARIBBEAN. UPPER FLOW WILL TILT
TO MORE SW ON WED AS STORM SYSTEM DEVELOPS OVER TN/MS VALLEY AREAS
POSSIBLY LEADING TO A SLIGHT INC IN POPS LOCALLY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 12Z...LOW CONFIDENCE EARLY DUE TO FOG/STRATUS...BECOMING HIGH
CONFIDENCE IN VFR BY THIS AFTN. MORE STRATUS IS POSSIBLE LATE IN
THIS VALID PERIOD.
A LINE OF SHOWERS ASSOCIATED WITH AN UPPER IMPULSE HAS MOVED AWAY
FROM THE AREA...BUT SOME LOW STRATUS CONTINUING ESPECIALLY NEAR THE
COAST. EXPECT THIS TO SCATTER OUT BY THE VALID TIME...BUT MAY STILL
CREATE SOME SHORT DURATION MVFR CIGS FOR A FEW HOURS THIS MORNING.
BIGGER CONCERN IS AT LBT WHERE VLIFR FOG AND IFR CIGS WILL CONTINUE
FOR AN HOUR OR TWO BEFORE LIFTING. AM A LITTLE SURPRISED TO SEE IFR
VSBYS AT LBT...BUT NOTE A SLIGHT DECREASE IN PG WHICH HAS ALLOWED
WINDS TO GO CALM. AS GRADIENT TIGHTENS THIS MORNING...AND MIXING
TAPS MUCH STRONGER WINDS ALOFT...ANY IFR WILL ERODE NO LATER THAN
9AM. THEREAFTER...VFR EXPECTED AT ALL TERMINALS WITH SW WINDS
GUSTING 20-25 KTS THROUGH THE DAY. LATEST NAM PROFILES SUGGEST THAT
MVFR CIGS WILL REDEVELOP THIS AFTN IN THE FORM OF A CU DECK...BUT
THIS IS LIKELY OVERDONE DUE TO DRY AIR IN THE MID LEVELS.
WINDS REMAIN ELEVATED AFTER SUNSET EVEN AS GUSTS DECREASE. ALL
GUIDANCE SUGGESTING WIDESPREAD IFR VSBYS AND STRATUS TONIGHT.
HOWEVER...AM NOT CONFIDENT IN THIS OCCURRING. FOR ONE...WINDS SHOULD
BE TOO STRONG TO SUPPORT IFR FOG...AND TWO...DEEP UNIDIRECTIONAL SW
FLOW IS NOT IDEAL FOR LOW STRATUS DEVELOPMENT. STILL...A VERY MOIST
AIRMASS IN PLACE COULD SUPPORT STRATUS SO HAVE MENTIONED SCT AT IFR
LEVEL FOR NOW AND WILL UPDATE WITH LATER ISSUANCES.
EXTENDED OUTLOOK...MODERATE CONFIDENCE FOR SHOWERS FRIDAY AFTN AND
EVE WITH AT LEAST MVFR. VFR SAT THROUGH MON.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 400 AM THURSDAY...SCA CONDITIONS FOR ALL WATERS BY
DAYBREAK...AND CONTINUING THROUGH DAYBREAK SATURDAY. WAA OVER THE
COOLER SHELF WATERS WILL BE A DETERRENT FOR THE STRONGER WINDS ALOFT
FROM MIXING DOWN. HOWEVER...A TIGHTENED SFC PG THROUGHOUT THE NEAR
TERM...WILL PRODUCE SW WINDS IN THE 15 TO 25 KT RANGE...WITH A FEW
GUSTS TO 30 KT ACROSS THE OUTER WATERS OFF CAPE FEAR WHERE SSTS ARE
IN THE 60S IN TURN ALLOWING WINDS ALOFT TO MIX TO THE OCEAN SFC.
SEAS WILL RANGE BETWEEN 3 AND 6 FT...EXCEPT FOR THE WATERS BETWEEN
CAPE FEAR TO MURRELLS INLET...WHERE SEAS WILL BE HIGHER BY 2 TO 3
FT...IE. 5 TO 9 FT...DUE TO AN INCREASED FETCH AND A FAVORABLE WIND
DIRECTION. THE DECAYING ESE 10-12 SECOND PERIOD SWELL OF THE PAST
SEVERAL DAYS HAS GIVEN UP TO THE LOCALLY PRODUCED SHORT PERIOD WIND
DRIVEN WAVES EXHIBITING 5 TO 8 SECOND PERIODS. THE ENERGY FROM THESE
WAVES BY FAR ENCOMPASS THE SIGNIFICANT SEAS THRUOUT THE NEAR TERM AS
WITNESSED WITH THE LATEST AND PROGGED SPECTRAL DENSITY CHARTS.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...DYNAMIC COLD FRONT TO KEEP A SOLID SMALL CRAFT
ADVISORY IN EFFECT ON FRIDAY. FRIDAY EVENING FROPA TO YIELD A SHARP
VEER AND A CONTINUATION OF SCA WINDS IN THE COLD SURGE EVEN AS THE
OFFSHORE COMPONENT OF THE WINDS STARTS TO KNOCK DOWN THE OVERALL
HEIGHT OF THE SEAS FIRST ALONG SHORE. BY SATURDAY THINGS WILL HAVE
SETTLED TO WHERE A SCEC WILL BE NEEDED AND CONTINUED IMPROVEMENT IN
CONDITIONS SLATED FOR THE AFTERNOON AND EVENING HOURS ALBEIT
SOMEWHAT GRADUAL IN NATURE.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 AM THURSDAY...SUNDAY BRINGS PROGRESSIVE AREA OF HIGH
PRESSURE THAT WILL GO FROM BEING OVER THE LANDMASS IN THE MORNING TO
OFF THE COAST BY EVENING. MODERATE NE WINDS TO START WILL VEER AND
LIGHTEN AS THE DAY WEARS ON WITH A CORRESPONDING ABATEMENT OF WAVE
HEIGHT. ADDITIONAL VEERING IS IN STORE FOR MONDAY BUT THE DEGREE OF
WIND CHANGE IS UNCERTAIN PENDING WHETHER OR NOT A COASTAL TROUGH
MANAGES TO DEVELOP. EVEN SO THERE WILL BE A PREDOMINANTLY ONSHORE
FLOW AND SEAS LIKELY IN THE 2 TO 3 FT RANGE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM THURSDAY TO 7 AM EST
SATURDAY FOR AMZ254-256.
SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR AMZ250-252.
&&
$$
NEAR TERM...DCH
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...XVII
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
415 AM EST THU FEB 23 2012
.SYNOPSIS...
WARM TEMPERATURES WILL PREVAIL OVER THE NEXT FEW DAYS AHEAD OF AN
APPROACHING COLD FRONT. SHOWERS AND A FEW STRONG THUNDERSTORMS ARE
POSSIBLE FRIDAY AS THE COLD FRONT PUSHES ACROSS THE REGION. DRY
AND COOLER AIR WILL OVERSPREAD THE EASTERN CAROLINAS THIS WEEKEND.
TEMPERATURES WILL REBOUND EARLY NEXT WEEK AS HIGH PRESSURE MOVES
OFFSHORE AND ALLOWS MILD SOUTHERLY WINDS TO SPREAD ACROSS THE
AREA.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 400 AM THURSDAY...CONVECTION HAVING APPROACHED FROM THE WEST
HAS DWINDLED AWAY EARLY THIS MORNING...WITH HRRR HAVING INDICATED
THAT THIS WOULD TAKE PLACE. LOW LEVEL MOISTURE AND A SCREAMING LOW
LEVEL JET 50+ KT AT 925 MB...WILL RESULT IN SCT/BKN LOW STRATUS
EARLY THIS MORNING. BY MID MORNING THE STRATUS DECK WILL DISSIPATE
AS THE JET DIMINISHES AND WITH THE DAYS INSOLATION HAVING COMMENCED.
A WEAK MID LEVEL S/W TROF ACCOMPANIED WITH CONVECTION AND MOVING
ACROSS THE APPALACHIAN MOUNTAINS...SHOULD EITHER PASS JUST NORTH OF
THE ILM CWA OR DISSIPATE AS IT TRACKS DOWN THE LEEWARD SIDE OF THE
MOUNTAINS. AS A RESULT HAVE KEPT POPS OUT OF THE FORECAST TODAY INTO
THIS EVENING. MODELS IN GOOD AGREEMENT WITH A SFC LOW AND ITS POTENT
UPPER S/W TROF EMERGING FROM THE ROCKY MOUNTAINS TODAY...THEN RACING
TO THE OHIO RIVER VALLEY BY EARLY THIS EVENING...AND REACHING LAKE
ERIE BY DAYBREAK FRIDAY. THE ASSOCIATED STRONG COLD FRONT....WILL BE
ON THE DOORSTEPS OF THE ILM CWA COME FRIDAY MORNING...IN ACTUALITY
LYING ACROSS THE CENTRAL CAROLINAS. AHEAD OF THE FRONT...EXCELLENT
WARM AIR ADVECTION TO OCCUR ACROSS THE FA AS EVIDENCED BY MODELS
INCREASING 8H TEMPS TO 14 TO 17 DEGREES CELSIUS BY EARLY FRIDAY
MORNING...WITH 1K-8H PARTIAL THICKNESSES REACHING 1392 TONIGHT. AND
THEY CALL THIS FEBRUARY? WITH THIS SAID...HAVE TWEAKED TODAYS MAX
TEMPS UPWARD BY A DEGREE OR 3...WITH A FEW LOCATIONS BREAKING THE 80
DEGREE MARK. WINDS WILL BE WSW IN THE MORNING...BACKING TO SW OR SSW
THIS AFTERNOON ALONG THE COAST WHICH WILL LIMIT MAX TEMPS TO THE
70-75 DEGREE RANGE BEFORE FALLING BACK INTO THE 60S THIS AFTERNOON
DUE TO ADJACENT SSTS IN THE 50S. A MILD EARLY MAY NITE PROGGED FOR
TONIGHT...HOWEVER THE CALENDER STATES ITS STILL FEBRUARY. LOOK FOR
LOWS IN THE 60S WITH SOME 50S ALONG THE IMMEDIATE COAST. POPS WILL
BEGIN TO RAMP UP TOWARDS DAYBREAK AS THE SFC COLD FRONT APPROACHES.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...MODELS HAVE TURNED MUCH DRIER WITH FRIDAY`S
DYNAMIC FROPA. WHILE GIVEN THE STRENGTH OF THE LOW LEVEL FORCING IT
SEEMS HARD TO GO AS DRY AS SAY THE WRF...WITH 00 RAINFALL IT DOES
APPEAR THAT FOR THE MOST PART RAINFALL AMOUNTS WILL DISAPPOINT
(GIVEN THE DROUGHT). LIKELY POPS WILL BE MAINTAINED SINCE ALTHOUGH
SIGNIFICANT RAINFALL MAY BE HARD TO COME BY MEASURABLE RAINFALL
SHOULD NOT. LOW LEVEL WIND FIELDS NOT AS STRONG AS PREV GUIDANCE SO
SEVERE THREAT SEEMS LESSENED BUT STILL CERTAINLY NON-ZERO. `SEVERE
SHOWERS` A LIKELY THREAT DUE TO LOW LEVEL WIND SPEED/STORM
MOTION/LACK OF INSTABILITY. STRONG CAA FRIDAY NIGHT INTO SATURDAY TO
BRING SLIGHTLY BELOW CLIMO TEMPS FOR THE REST OF THE PERIOD WHILE
SKY CLEARS OUT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 3 AM THURSDAY...PROGRESSIVE FLOW IN PLACE AT THE START OF THE
PERIOD WITH ZONAL MID LEVEL FLOW QUICKLY SPREADING ACROSS THE
SOUTHEAST. LARGE AREA OF SURFACE HIGH PRESSURE WILL ALSO BE NEARING
THE COAST MAKING SUNDAY ONE LAST DAY OF NEAR TO SLIGHTLY BLOW CLIMO
TEMPS. THIS HIGH WILL END UP OFFSHORE BY MONDAY LEADING TO MILDER
WEATHER AND THE RETURN FLOW OF SOME MOISTURE. THIS MAY EITHER SIMPLY
TAKE THE FORM OF SOME CLOUDINESS OR SOME LOW RAIN CHANCES SHOULD A
COASTAL TROUGH DEVELOP AS INDICATED BY SOME MODELS. HIGH PRESSURE
WILL SIMILARLY BE FOUND WELL OFF THE COAST ON TUESDAY WHILE A COLD
FRONT LIES ALIGNED WITH THE ZONAL FLOW SOMEWHERE NEAR THE
MASON-DIXON LINE. WHILE RAIN CHANCES REMAIN TOUGH TO RULE OUT THERE
STILL REALLY ISNT MUCH FOR A TRIGGERING MECHANISM ESPECIALLY GIVEN
THE BROAD UPPER HIGH OVER THE GOMEX/CARIBBEAN. UPPER FLOW WILL TILT
TO MORE SW ON WED AS STORM SYSTEM DEVELOPS OVER TN/MS VALLEY AREAS
POSSIBLY LEADING TO A SLIGHT INC IN POPS LOCALLY.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 06Z...LOOKS LIKE CONVECTION OFF OF FLORIDA MAY HAVE STOLEN
MUCH OF THE ENERGY FOR PRECIP IN OUR AREA...CERTAINLY OVER OUR
SOUTHERN PORTION OF THE CWA. BAROCLINIC LEAF TO THE NORTH AND
ASSOCIATED PCPN WILL LIKELY SCRAPE ACROSS THE NORTHERN PORTIONS OF
THE ILM CWA...WITH LBT AND POSSIBLY FLO HAVING SHRA IN THE VICINITY.
HRRR HAS MUCH OF THE PCPN DYING OUT AS IT MOVES INTO THE EASTERN
CAROLINAS...LIKELY DUE TO LOW LEVEL MARINE INFLUENCES...IE. WINDS
200 AT 10G20KT. LOW LEVEL MOISTURE SHOULD BE SUFFICIENT ENOUGH TO
PRODUCE LOW STRATUS CEILINGS TOWARD DAYBREAK. BUFKIT SHOWS STRONG
SPEED SHEAR...MAINLY FROM 500 FT TO 1500 FT...AND HAVE ADDED WIND
SHEAR TO THE TERMINALS FOR THIS MORNING. INLAND COULD SEE THE
STRATUS AT TIMES DROP TO THE SFC WHICH WILL HINDER HORIZONTAL VSBY.
IMPROVING CEILING AND VSBY CONDITIONS BY 15Z-16Z. HOWEVER...EXPECT
CONTINUED GUSTY WEST SOUTHWEST WINDS THROUGHOUT TODAY...WITH WINDS
BACKING SLIGHTLY TO THE SW OR SSW THIS AFTERNOON AND EVENING.
EXTENDED OUTLOOK...EXPECT VFR THROUGH THURSDAY. MODERATE CONFIDENCE
FOR SHOWERS FRIDAY THROUGH MID AFTERNOON. VFR SAT THROUGH MON.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 400 AM THURSDAY...SCA CONDITIONS FOR ALL WATERS BY
DAYBREAK...AND CONTINUING THROUGH DAYBREAK SATURDAY. WAA OVER THE
COOLER SHELF WATERS WILL BE A DETERRENT FOR THE STRONGER WINDS ALOFT
FROM MIXING DOWN. HOWEVER...A TIGHTENED SFC PG THROUGHOUT THE NEAR
TERM...WILL PRODUCE SW WINDS IN THE 15 TO 25 KT RANGE...WITH A FEW
GUSTS TO 30 KT ACROSS THE OUTER WATERS OFF CAPE FEAR WHERE SSTS ARE
IN THE 60S IN TURN ALLOWING WINDS ALOFT TO MIX TO THE OCEAN SFC.
SEAS WILL RANGE BETWEEN 3 AND 6 FT...EXCEPT FOR THE WATERS BETWEEN
CAPE FEAR TO MURRELLS INLET...WHERE SEAS WILL BE HIGHER BY 2 TO 3
FT...IE. 5 TO 9 FT...DUE TO AN INCREASED FETCH AND A FAVORABLE WIND
DIRECTION. THE DECAYING ESE 10-12 SECOND PERIOD SWELL OF THE PAST
SEVERAL DAYS HAS GIVEN UP TO THE LOCALLY PRODUCED SHORT PERIOD WIND
DRIVEN WAVES EXHIBITING 5 TO 8 SECOND PERIODS. THE ENERGY FROM THESE
WAVES BY FAR ENCOMPASS THE SIGNIFICANT SEAS THRUOUT THE NEAR TERM AS
WITNESSED WITH THE LATEST AND PROGGED SPECTRAL DENSITY CHARTS.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...DYNAMIC COLD FRONT TO KEEP A SOLID SMALL CRAFT
ADVISORY IN EFFECT ON FRIDAY. FRIDAY EVENING FROPA TO YIELD A SHARP
VEER AND A CONTINUATION OF SCA WINDS IN THE COLD SURGE EVEN AS THE
OFFSHORE COMPONENT OF THE WINDS STARTS TO KNOCK DOWN THE OVERALL
HEIGHT OF THE SEAS FIRST ALONG SHORE. BY SATURDAY THINGS WILL HAVE
SETTLED TO WHERE A SCEC WILL BE NEEDED AND CONTINUED IMPROVEMENT IN
CONDITIONS SLATED FOR THE AFTERNOON AND EVENING HOURS ALBEIT
SOMEWHAT GRADUAL IN NATURE.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 AM THURSDAY...SUNDAY BRINGS PROGRESSIVE AREA OF HIGH
PRESSURE THAT WILL GO FROM BEING OVER THE LANDMASS IN THE MORNING TO
OFF THE COAST BY EVENING. MODERATE NE WINDS TO START WILL VEER AND
LIGHTEN AS THE DAY WEARS ON WITH A CORRESPONDING ABATEMENT OF WAVE
HEIGHT. ADDITIONAL VEERING IS IN STORE FOR MONDAY BUT THE DEGREE OF
WIND CHANGE IS UNCERTAIN PENDING WHETHER OR NOT A COASTAL TROUGH
MANAGES TO DEVELOP. EVEN SO THERE WILL BE A PREDOMINANTLY ONSHORE
FLOW AND SEAS LIKELY IN THE 2 TO 3 FT RANGE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM THURSDAY TO 7 AM EST SATURDAY
FOR AMZ254-256.
SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR AMZ250-252.
&&
$$
NEAR TERM...DCH
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...DCH/HDL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1019 AM EST THU FEB 23 2012
.SYNOPSIS...
LOW PRESSURE WILL DEVELOP OVER THE MIDDLE MISSISSIPPI VALLEY
TODAY. THE LOW WILL DEEPEN TONIGHT AS IT MOVES NORTHEAST TOWARD THE
EASTERN GREAT LAKES. A COLD FRONT WILL SWEEP ACROSS THE AREA IN
THE WAKE OF THE LOW...BRINGING MUCH COLDER AIR TO THE OHIO VALLEY
ON FRIDAY. COLD AIR ALONG WITH SNOW SHOWERS CAN BE EXPECTED FOR
THE FIRST PART OF THE WEEKEND. HIGH PRESSURE WILL RETURN TO THE
OHIO VALLEY ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATED FORECAST LARGELY KEEPS RAIN CHANCES AS-IS THROUGH LATE
AFTERNOON AND ONLY SERVES TO TIGHTEN THE TEMPERATURE GRADIENT
ACROSS THE FORECAST AREA TODAY. MONITORING FOR THE POTENTIAL FOR
SEVERE WEATHER VERY LATE THIS AFTERNOON AND THIS EVENING IN THE SOUTH.
WEAK IMPULSE THIS MORNING OVER NRN IL ALLOWING MID LEVEL FLOW TO
BACK AND INDUCE MODEST OVERRUNNING/ISENTROPIC LIFT /295K/. THIS IS
DRIVING A FAIRLY SUBSTANTIAL DECK OF MID-LEVEL CLOUDS AND BAND OF
LIGHT PRECIPITATION ACROSS CNTL IND WHERE THE LEADING EDGE HAS
BEEN WORKING TO OVERCOME A DRY SUB-CLOUD LAYER. CONTINUE TO THINK
THIS WILL BRING A BRIEF PERIOD OF LIGHT RAIN TO MAINLY AREAS NORTH
OF I-70 LATE THIS MORNING AND INTO THE MID AFTERNOON.
CLEARING NOW DEVELOPING OVER SRN IL IS OF INTEREST GIVEN THE
DYNAMIC SHORTWAVE DIGGING THROUGH NEB AND TOWARD THE OH VALLEY. IN
FACT...CONVECTIVE CLOUD ELEMENTS NOW SHOWING IN THIS AREA AS THIS
AREA DESTABILIZES RAPIDLY. THIS WAVE WILL INDUCE A DEEPENING SFC
LOW AND STRENGTHENING WARM FRONT ALONG THE OHIO RIVER TO OUR SW
THIS AFTERNOON...WITH A STRONG FLUX OF LOW LEVEL MOISTURE AND
CONVERGENCE INTO SRN INDIANA/NRN KY BY LATE THIS AFTERNOON. BULK OF
CONVECTION-ALLOWING /4KM/ MODELS INITIATE SHALLOW CONVECTION IN
THIS AREA AROUND 21Z...EXPANDING IT RAPIDLY EAST/NORTHEAST AS WARM
SECTOR PUSHES NORTH ATTENDANT TO DEEPENING CYCLONE. BIGGEST
CONCERN IS FOR SEVERE STORMS NEAR AND SOUTH OF OHIO RIVER WHERE
LOW LEVEL INHIBITION IS MINIMIZED /MORE SLY/SELY SFC TRAJECTORY
WITH MORE BUOYANT AIRMASS/. FORECAST RUC SOUNDINGS NORTH OF WARM
FRONT /MORE ELY TRAJECTORY/ HAVE TREMENDOUS SHEAR/LONG HODOGRAPHS
BUT SLIGHTLY INVERTED LOW LEVEL TEMP TRACE THAT WILL GREATLY
INHIBIT TORNADO THREAT ESPECIALLY GIVEN THE VERY MEAGER INSTBY.
OUR GREATEST CONCERN IS CURRENTLY NRN KENTUCKY INTO EXTREME SCNTL
OH...ESP AREAS SOUTH/WEST OF CVG OVER TOWARD AREAS SOUTHWEST OF
PMH. WITH EVERY TIER OF COUNTIES SOUTH...THE LOW LEVEL
THERMODYNAMICS ARE MORE FAVORABLE TO TAP VERY IMPRESSIVE SHEAR
WITH 0-1KM VALUES IN EXCESS OF 40KTS. WITH EVERY TIER OF COUNTIES
NORTH BECOMES A LESS FAVORABLE LOW LEVEL AIRMASS AND EVEN MORE
MEAGER /RELATIVE/ INSTABILITY. THIS WILL BE A RAPIDLY CHANGING
AIRMASS/THETA-E PROFILE THIS EVENING AND WILL NEED TO BE WATCHED
CLOSELY. IF STORM CLUSTER CAN BECOME ROOTED ALONG THE WARM
FRONT...COULD BECOME A VERY ACTIVE PERIOD BETWEEN 22Z-03Z.
AFTER THE LOW/STORM CLUSTER PASS TO THE NORTHEAST...A BIG PUSH OF
WIND THAT MAY REQUIRE AN ADVISORY DESPITE POOR CLIMATOLOGY TIME
PERIOD. STRONG COLD ADVECTION/ISALLOBARIC FORCING AND REMNANT LOW
LEVEL JET PUT MUCH OF THE CWA IN PRIME ZONE FOR A PERIOD WHERE
WINDS COULD GUST TO 45MPH OR HIGHER.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
SFC LOW AND ASSOCIATE S/WV WILL PIVOT NE ACRS NEW ENGLAND/SAINT
LAWRENCE RIVER VALLEY ON FRIDAY WHILE AN UPPER LEVEL TROF AND
EMBEDDED DISTURBANCES WITHIN THE FLOW BEGIN TO AFFECT THE REGION.
COLDER AIR WILL CONTINUE TO FILTER IN ON FRIDAY ALONG WITH
SCATTERED RAIN SHOWERS AND SNOW SHOWERS. PCPN SHOULD CHANGE TO ALL
SNOW BY FRIDAY NIGHT AS TEMPERATURES CONTINUE TO FALL. BY
SATURDAY...COLD UPR LVL TROF WILL BEGIN TO PIVOT NE. 850 MB COLD
POOL WILL BE AT ITS MAXIMUM RESULTING IN BELOW NORMAL TEMPERATURES
AND LINGERING SNOW SHOWERS. UPR LVL TROF WILL PUSH OFF THE
ATLANTIC SEABOARD SATURDAY NIGHT...ALLOWING SFC HIGH PRESSURE TO
BUILD INTO THE OHIO VALLEY. ON SUNDAY...SFC HIGH WILL MOVE EAST.
ALONG WITH MOSTLY SUNNY SKIES...TEMPERATURES WILL REBOUND IN THE
RETURN FLOW PATTERN ON THE BACK SIDE OF THE DEPARTING HIGH.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
A STRONG LOW WILL MOVE THROUGH THE UPPER MIDWEST TO THE NORTHERN
GREAT LAKES REGION SUNDAY AND MONDAY...TRAILING A COLD FRONT
THROUGH THE OHIO VALLEY. MODELS DIFFER ON THE TRACK AND STRENGTH
OF THE LOW AND ITS ASSOCIATED COLD FRONT. THIS DIFFERENCE WILL
RESULT IN A HIGHER UNCERTAINTY IN THE CHANCES OF RAIN AHEAD OF THE
FRONT ON MONDAY...AND WITH ITS PASSAGE MONDAY NIGHT.
HIGH PRESSURE AND A DRY PATTERN IS IN STORE FOR TUESDAY IN THE OHIO
VALLEY. MODELS QUICKLY DIVERGE IN THEIR OVERALL REPRESENTATION OF
THE PATTERNS BEGINNING TUESDAY. 0Z MODEL BLEND IS USED BY HPC
THROUGH TUESDAY AND THEN A BLEND WITH THE 12Z ECMWF IS USED FOR
MIDWEEK. WILL USE THE LATEST EUROPEAN FOR THE TUES NIGHT/WED
FORECAST WHEN IT COMES IN.
HIGH TEMPERATURES WILL BE AROUND NORMAL FOR MUCH OF THE PERIOD.
LOWS WILL RISE BACK TO ABOVE NORMAL LEVELS WHICH HAVE BEEN COMMON
THIS WINTER SEASON.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
PRIMARY CONCERN FOR THE TAFS IS CHANCES FOR RAIN (POSSIBLY WITH
THUNDER) AND STRONG WINDS AT VARIOUS POINTS THROUGH THE VALID
FORECAST PERIOD.
WINDS ARE LIGHT AND VARIABLE OVER THE REGION RIGHT NOW...BUT WILL
EVENTUALLY TURN SOUTHEASTERLY TO EASTERLY DURING THE MORNING. AN
INITIAL AREA OF RAIN WILL MOVE ACROSS THE TAF SITES BY EARLY
AFTERNOON...BUT WITH LITTLE IMPACT TO AVIATION CONDITIONS. HAVE
ONLY INCLUDED RAIN IN THE PREVAILING SECTION OF THE FORECAST FOR
THE NORTHERN TAF SITES.
THEREAFTER...LOW PRESSURE TRACKING ACROSS OHIO WILL INTRODUCE A
MORE SIGNIFICANT CHANCE OF RAINFALL...AND POSSIBLY THUNDERSTORMS.
THE BEST TIMING FOR THIS ACTIVITY WILL BE DURING THE EVENING
HOURS...AS IS DENOTED WITH A PERIOD OF -SHRA. MVFR CEILINGS ARE
EXPECTED TO ACCOMPANY THIS ACTIVITY FOR SURE FOR THE NORTHERN TAF
SITES. HEAVIER SHOWERS COULD ALSO BRING MVFR VISIBILITIES.
THUNDERSTORMS ARE ALSO POSSIBLE...WITH THE BEST CHANCE BEING AT
THE CINCINNATI TAF SITES. IF THUNDERSTORMS DEVELOP...IFR
CONDITIONS AND GUSTY WINDS WILL BE POSSIBLE.
OVERNIGHT...WINDS WILL SHIFT TO THE WEST AS THE FRONTAL BOUNDARY
PASSES BY. THIS WILL END THE TAF PERIOD WITH SOME VERY STRONG WIND
GUSTS (ABOVE 30 KNOTS).
OUTLOOK...GUSTY WESTERLY WINDS WILL BE POSSIBLE ON FRIDAY. MVFR
CEILINGS ARE POSSIBLE FRIDAY NIGHT INTO SATURDAY MORNING.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...BINAU
SHORT TERM...HICKMAN
LONG TERM...FRANKS
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
215 PM MST THU FEB 23 2012
.UPDATE...
ISSUED AT 214 PM MST THU FEB 23 2012
WEB CAMS INDICATE THE SUN HAS BEGUN TO POKE THROUGH OVER THE
CENTRAL MOUNTAINS. OBSERVATIONS ALSO VERIFY THAT SNOW AND WIND ARE
DIMINISHING THERE. THEREFORE LET THE WINTER HIGHLIGHTS EXPIRE.
WHILE SOME SNOW AND BLOWING SNOW WILL CONTINUE OVER THESE AND THE
OTHER COLORADO MOUNTAINS...CONDITIONS HAVE MARKEDLY IMPROVED.
HAVE ALSO CANCELED THE WIND ADVISORY FOR ALL THE CO ZONE 22...THE
DURANGO AREA. WHILE BREEZY CONDITIONS PERSIST OVER MUCH OF THE
FORECAST AREA...WIND SPEEDS HAVE DECREASED AND ARE WELL BELOW
ADVISORY CRITERIA MOST LOCATIONS. THE EXCEPTION TO THIS IS OVER
CO ZONE 22. GUSTS AT THE LA PLATA COUNTY AIRPORT CONTINUE TO PUSH
AGAINST THE CRITERIA OF 45 MPH...SO WILL LET THE ADVISORY RIDE.
UPDATE ISSUED AT 1053 AM MST THU FEB 23 2012
WINDS HAVE DIMINISHED THIS MORNING ACROSS AREAS BEHIND THE FRONT.
WHILE CONDITIONS WILL REMAIN BREEZY...AND WITH WINDS EVEN
INCREASING SOMEWHAT BY MIDDAY...THEY ARE NOT EXPECTED TO BE AS
STRONG AS WHAT WAS ASSOCIATED WITH THE FRONT. THEREFORE THE WIND
ADVISORY WILL BE DROPPED FOR THE CENTRAL VALLEYS AND NORTHWARD.
WIND ADVISORIES WILL CONTINUE FOR THE SOUTHERN VALLEYS.
IN ADDITION...SNOW HAS WOUND DOWN OVER MANY OF THE MOUNTAIN AREAS...
AND THE STEAMBOAT SPRINGS AREA. WHILE SNOW SHOWERS WILL CONTINUE
THROUGH THIS AFTERNOON...LITTLE TO NO ADDITIONAL ACCUMULATIONS ARE
EXPECTED. THEREFORE WILL LET THE WINTER STORM WARNING FOR THE
NORTHERN MOUNTAINS AND THE STEAMBOAT AREA EXPIRE AT 11 AM...AND
WILL CANCEL THE SNOW ADVISORIES FOR THE COLORADO TAVAPUTS AND THE
GRAND MESA WHERE SUN HAS BROKEN THROUGH. WILL LET THE HIGHLIGHTS
RIDE FOR THE CENTRAL DIVIDE FOR NOW...CO ZONES 10/12. SNOW CONTINUES
OVER MUCH OF THOSE ZONES...AND WINDS STILL QUITE STRONG. THE
COMBINATION WILL KEEP CONDITIONS HAZARDOUS FOR AWHILE YET.
UPDATE ISSUED AT 625 AM MST THU FEB 23 2012
COLD FRONT PROGRESSING SOUTH THIS MORNING AND CURRENTLY BETWEEN
THE I70 CORRIDOR AND A LINE FROM MONTROSE TO THE GUNNISON VALLEY.
FARTHER EAST WITHIN THE BAROCLINIC ZONE...THE MOUNTAINS GETTING
POUNDED WITH SNOW AND WIND AND I70 IS CURRENTLY SHUT DOWN EAST OF
VAIL. HRRR DATA SHOWS PLENTY OF WIND PROGRESSING SOUTH WITH THE
FRONT AND HAVE ISSUED WIND ADVISORY FOR THE VALLEYS OF SOUTHEAST
UTAH AND SOUTHWEST COLORADO. IN THE MOUNTAINS...WINTER WEATHER
ADVISORY ADDRESSES THE COMBINATION OF SNOW AND WIND. A BURST OF
HEAVY SNOW AND WIND OCCURS WITH THE FRONT PASSAGE...BUT THE FRONT
IS MOVING FAIRLY QUICKLY WITH DRY ADVECTION OCCURRING BEHIND THE
FRONT. DO NOT EXPECT MUCH SNOW ACCUMULATION TO OCCUR THIS
AFTERNOON AS THE AIR MASS WILL BE VERY DRY. THERE IS A 2-3 HOUR
PERIOD OF NASTY CONDITIONS...AS EVIDENT ON THE WEB CAMS OVER VAIL
PASS AND EXPECT SIMILAR CONDITIONS TO OCCUR OVER MONARCH PASS.
THE SAN JUAN MOUNTAINS MAY NEED A WINTER WEATHER ADVISORY AS
WELL...BUT DYNAMICAL SUPPORT WILL BE MOVING DOWNSTREAM AS THE
FRONT MOVES INTO SW COLORADO. WILL CONTINUE TO MONITOR THIS SITUATION.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 217 AM MST THU FEB 23 2012
A STRONG COLD FRONT IS WORKING ITS WAY SOUTHWARD THROUGH NORTHWESTERN
COLORADO AT 09Z...EXPECT IT WILL WORK ITS WAY TO GJT AROUND 12Z.
FRONT IS PRETTY ENERGETIC WITH GOOD Q CONVERGENCE AND FRONTOGENETIC
FORCING. HOWEVER THE DEEPEST MOISTURE AND BEST CHANCES OF PCPN
WILL BE OVER THE NRN AND PORTIONS OF CNTRL MTNS WHERE WINTER
WEATHER HIGHLIGHTS ARE CURRENTLY IN PLACE. ITS STILL RAINING IN
CAG BEHIND THE FRONT BUT EXPECT THEY WILL TURN TO SNOW SHORTLY...WHILE
AT THE HIGHER ELEVATIONS A GOOD BURST OF HEAVY SNOW WILL PRECEDE
AND ACCOMPANY THE FRONT. WINDS STILL REMAIN A FACTOR WITH GUSTS UP
70KTS OVER SOME OF THE HIGHER MTNS (MT ABRAMS). AT THIS TIME THE
CURRENT HIGHLIGHTS ARE IN GOOD SHAPE WITH RESPECT TO AREAL
COVERAGE AND TIMING/INTENSITY OF SNOWFALL. ALSO THE WIND ADVISORY
OVER THE NW PLATEAU LOOKS IN GOOD SHAPE WITH SEVERAL RAWS SITES
INDICATING GUSTS OF 45 MPH OR HIGHER.
EXPECT THE INTENSITY OF SNOWFALL TO TAPER OFF BEHIND THE FRONT AS
MUCH DRIER AND COOLER AIR MOVES IN FROM THE NORTH. AS FOR THE LOWER
WESTERN VALLEYS OF COLORADO AND MOST ALL OF EASTERN UT...THIS
LOOKS LIKE MORE A WIND STORM THAN PCPN PRODUCER.
A FEW SHOWERS WILL LINGER OVER THE NW FACING SLOPES OF THE NRN AND
EAST CENTRAL MTNS TONIGHT...DECREASING AFTER MIDNIGHT. ELSEWHERE
DRY CONDITIONS WITH MUCH COOLER OVERNIGHT LOWS ARE EXPECTED.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 217 AM MST THU FEB 23 2012
FRIDAY...PROGRESSIVE RIDGE WILL MOVE ACROSS THE INTERMOUNTAIN WEST
ON FRIDAY AND WILL BRING DRY WEATHER. STRONG SURFACE BASED
INVERSIONS WILL KEEP VALLEYS COOL.
RIDGE CONTINUES DOWNSTREAM ON SATURDAY AND ALLOWS A STRONG PACIFIC
TROUGH TO MOVE ACROSS THE NWRN CONUS. THE 00Z MODEL SUITE SUPPORTS
YESTERDAYS 12Z TREND THAT THE DIGGING TROUGH WILL NOT BE AS
PRONOUNCED. DEEP SURFACE CYCLONE TRACKS ACROSS THE NRN
PLAINS...BUT THIS CYCLONE WILL COVER PLENTY OF TERRITORY. PRESSURE
GRADIENTS WILL TIGHTEN SIGNIFICANTLY SATURDAY AFTERNOON ONCE THE
SURFACE TROUGH DEVELOPS IN THE PLAINS. THE GREATEST IMPACT FROM
THIS PACIFIC WAVE MAY VERY WELL BE WIND AS THIS SYSTEM HARDLY
ENTRAINS ANY MOISTURE. LATEST GUIDANCE SHOW DEW POINTS CRASHING
INTO THE SINGLE DIGITS AND TEENS IN THE AFTERNOON ONCE THE SURFACE
BASED INVERSIONS MIX OUT. THE BEST DYNAMICAL LIFT...COINCIDING
WITH STRONG MID LEVEL COLD ADVECTION...OCCURS SATURDAY EVENING
WITH THE BEST CHANCE OF SNOW OCCURRING OVER THE NRN MOUNTAINS.
MODERATE TO HEAVY SNOW ACROSS THE PARK RANGE IS POSSIBLE FOR 3-4
HOURS AS THE COLD POCKET SWEEPS ACROSS NW COLORADO. OTHERWISE THIS
SYSTEM IS MOISTURE STARVED AND DIABATIC COOLING WILL HAVE A TOUGH
TIME MOISTENING THE AIR MASS WITH PRECIPITABLE WATER CONTENT OF
ONLY A QUARTER INCH.
SUNDAY THROUGH TUESDAY...A SECONDARY SHORT WAVE DIGS INTO THE GREAT
BASIN ON SUNDAY NIGHT. THIS WILL BE FOLLOWED BY ANOTHER DIGGING
WAVE FROM ALBERTA ON TUESDAY THAT REINFORCES THE COLDER AIR MASS
ACROSS THE REGION. NEITHER OF THESE FEATURES WILL HAVE MUCH
MOISTURE TO WORK WITH...BUT DOES KEEP THE AIR MASS COOL AND
UNSETTLED WITH A CHANCE OF MOUNTAIN SNOW SHOWERS.
APPEARS THAT NEXT WEDNESDAY WILL BE DRY AS TRANSITORY RIDGE MOVES
ACROSS THE REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1053 AM MST THU FEB 23 2012
STRONG GUSTY WINDS HAVE DEVELOPED OVER THE SOUTHERN THIRD OF THE
FORECAST AREA...WHILE DECREASING SOMEWHAT OVER THE NORTH...AS A COLD
FRONT PUSHES SOUTHWARD. SNOW HAS ALSO DEVELOPED OVER THE SOUTHERN
MOUNTAINS AND IN SOME HIGHER VALLEY AREAS. WHILE SNOW HAS DIMINISHED
OVER THE NORTH...SNOW SHOWERS WILL CONTINUE THROUGH THE DAY OVER ALL
MOUNTAIN AREAS. THEREFORE AREAS OF MVFR/IFR CIGS/VIS...AND TURBULENT
MIXING WILL PERSIST THROUGH THE DAY OVER THE MOUNTAIN AREAS. LOW
LEVEL WIND SHEAR WILL ALSO BE POSSIBLE IN SOME VALLEY AREAS AS LOCAL
WINDS DIMINISH NEAR THE SURFACE. GRADUAL IMPROVEMENT IS EXPECTED
LATE THIS AFTERNOON THROUGH THIS EVENING. OTHERWISE VFR CONDITIONS
EXPECTED AT THE LOWER VALLEY SITES OF WESTERN COLORADO AND EASTERN
UTAH...WITH VFR EVERYWHERE BY LATE THIS EVENING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WIND ADVISORY UNTIL 6 PM MST THIS EVENING FOR COZ022.
UT...NONE.
&&
$$
UPDATE...EH
SHORT TERM...MC
LONG TERM....PF
AVIATION...EH
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1053 AM MST THU FEB 23 2012
.UPDATE...
ISSUED AT 1053 AM MST THU FEB 23 2012
WINDS HAVE DIMINISHED THIS MORNING ACROSS AREAS BEHIND THE FRONT.
WHILE CONDITIONS WILL REMAIN BREEZY...AND WITH WINDS EVEN
INCREASING SOMEWHAT BY MIDDAY...THEY ARE NOT EXPECTED TO BE AS
STRONG AS WHAT WAS ASSOCIATED WITH THE FRONT. THEREFORE THE WIND
ADVISORY WILL BE DROPPED FOR THE CENTRAL VALLEYS AND NORTHWARD.
WIND ADVISORIES WILL CONTINUE FOR THE SOUTHERN VALLEYS.
IN ADDITION...SNOW HAS WOUND DOWN OVER MANY OF THE MOUNTAIN AREAS...
AND THE STEAMBOAT SPRINGS AREA. WHILE SNOW SHOWERS WILL CONTINUE
THROUGH THIS AFTERNOON...LITTLE TO NO ADDITIONAL ACCUMULATIONS ARE
EXPECTED. THEREFORE WILL LET THE WINTER STORM WARNING FOR THE
NORTHERN MOUNTAINS AND THE STEAMBOAT AREA EXPIRE AT 11 AM...AND
WILL CANCEL THE SNOW ADVISORIES FOR THE COLORADO TAVAPUTS AND THE
GRAND MESA WHERE SUN HAS BROKEN THROUGH. WILL LET THE HIGHLIGHTS
RIDE FOR THE CENTRAL DIVIDE FOR NOW...CO ZONES 10/12. SNOW CONTINUES
OVER MUCH OF THOSE ZONES...AND WINDS STILL QUITE STRONG. THE
COMBINATION WILL KEEP CONDITIONS HAZARDOUS FOR AWHILE YET.
UPDATE ISSUED AT 625 AM MST THU FEB 23 2012
COLD FRONT PROGRESSING SOUTH THIS MORNING AND CURRENTLY BETWEEN
THE I70 CORRIDOR AND A LINE FROM MONTROSE TO THE GUNNISON VALLEY.
FARTHER EAST WITHIN THE BAROCLINIC ZONE...THE MOUNTAINS GETTING
POUNDED WITH SNOW AND WIND AND I70 IS CURRENTLY SHUT DOWN EAST OF
VAIL. HRRR DATA SHOWS PLENTY OF WIND PROGRESSING SOUTH WITH THE
FRONT AND HAVE ISSUED WIND ADVISORY FOR THE VALLEYS OF SOUTHEAST
UTAH AND SOUTHWEST COLORADO. IN THE MOUNTAINS...WINTER WEATHER
ADVISORY ADDRESSES THE COMBINATION OF SNOW AND WIND. A BURST OF
HEAVY SNOW AND WIND OCCURS WITH THE FRONT PASSAGE...BUT THE FRONT
IS MOVING FAIRLY QUICKLY WITH DRY ADVECTION OCCURRING BEHIND THE
FRONT. DO NOT EXPECT MUCH SNOW ACCUMULATION TO OCCUR THIS
AFTERNOON AS THE AIR MASS WILL BE VERY DRY. THERE IS A 2-3 HOUR
PERIOD OF NASTY CONDITIONS...AS EVIDENT ON THE WEB CAMS OVER VAIL
PASS AND EXPECT SIMILAR CONDITIONS TO OCCUR OVER MONARCH PASS.
THE SAN JUAN MOUNTAINS MAY NEED A WINTER WEATHER ADVISORY AS
WELL...BUT DYNAMICAL SUPPORT WILL BE MOVING DOWNSTREAM AS THE
FRONT MOVES INTO SW COLORADO. WILL CONTINUE TO MONITOR THIS SITUATION.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 217 AM MST THU FEB 23 2012
A STRONG COLD FRONT IS WORKING ITS WAY SOUTHWARD THROUGH NORTHWESTERN
COLORADO AT 09Z...EXPECT IT WILL WORK ITS WAY TO GJT AROUND 12Z.
FRONT IS PRETTY ENERGETIC WITH GOOD Q CONVERGENCE AND FRONTOGENETIC
FORCING. HOWEVER THE DEEPEST MOISTURE AND BEST CHANCES OF PCPN
WILL BE OVER THE NRN AND PORTIONS OF CNTRL MTNS WHERE WINTER
WEATHER HIGHLIGHTS ARE CURRENTLY IN PLACE. ITS STILL RAINING IN
CAG BEHIND THE FRONT BUT EXPECT THEY WILL TURN TO SNOW SHORTLY...WHILE
AT THE HIGHER ELEVATIONS A GOOD BURST OF HEAVY SNOW WILL PRECEDE
AND ACCOMPANY THE FRONT. WINDS STILL REMAIN A FACTOR WITH GUSTS UP
70KTS OVER SOME OF THE HIGHER MTNS (MT ABRAMS). AT THIS TIME THE
CURRENT HIGHLIGHTS ARE IN GOOD SHAPE WITH RESPECT TO AREAL
COVERAGE AND TIMING/INTENSITY OF SNOWFALL. ALSO THE WIND ADVISORY
OVER THE NW PLATEAU LOOKS IN GOOD SHAPE WITH SEVERAL RAWS SITES
INDICATING GUSTS OF 45 MPH OR HIGHER.
EXPECT THE INTENSITY OF SNOWFALL TO TAPER OFF BEHIND THE FRONT AS
MUCH DRIER AND COOLER AIR MOVES IN FROM THE NORTH. AS FOR THE LOWER
WESTERN VALLEYS OF COLORADO AND MOST ALL OF EASTERN UT...THIS
LOOKS LIKE MORE A WIND STORM THAN PCPN PRODUCER.
A FEW SHOWERS WILL LINGER OVER THE NW FACING SLOPES OF THE NRN AND
EAST CENTRAL MTNS TONIGHT...DECREASING AFTER MIDNIGHT. ELSEWHERE
DRY CONDITIONS WITH MUCH COOLER OVERNIGHT LOWS ARE EXPECTED.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 217 AM MST THU FEB 23 2012
FRIDAY...PROGRESSIVE RIDGE WILL MOVE ACROSS THE INTERMOUNTAIN WEST
ON FRIDAY AND WILL BRING DRY WEATHER. STRONG SURFACE BASED
INVERSIONS WILL KEEP VALLEYS COOL.
RIDGE CONTINUES DOWNSTREAM ON SATURDAY AND ALLOWS A STRONG PACIFIC
TROUGH TO MOVE ACROSS THE NWRN CONUS. THE 00Z MODEL SUITE SUPPORTS
YESTERDAYS 12Z TREND THAT THE DIGGING TROUGH WILL NOT BE AS
PRONOUNCED. DEEP SURFACE CYCLONE TRACKS ACROSS THE NRN
PLAINS...BUT THIS CYCLONE WILL COVER PLENTY OF TERRITORY. PRESSURE
GRADIENTS WILL TIGHTEN SIGNIFICANTLY SATURDAY AFTERNOON ONCE THE
SURFACE TROUGH DEVELOPS IN THE PLAINS. THE GREATEST IMPACT FROM
THIS PACIFIC WAVE MAY VERY WELL BE WIND AS THIS SYSTEM HARDLY
ENTRAINS ANY MOISTURE. LATEST GUIDANCE SHOW DEW POINTS CRASHING
INTO THE SINGLE DIGITS AND TEENS IN THE AFTERNOON ONCE THE SURFACE
BASED INVERSIONS MIX OUT. THE BEST DYNAMICAL LIFT...COINCIDING
WITH STRONG MID LEVEL COLD ADVECTION...OCCURS SATURDAY EVENING
WITH THE BEST CHANCE OF SNOW OCCURRING OVER THE NRN MOUNTAINS.
MODERATE TO HEAVY SNOW ACROSS THE PARK RANGE IS POSSIBLE FOR 3-4
HOURS AS THE COLD POCKET SWEEPS ACROSS NW COLORADO. OTHERWISE THIS
SYSTEM IS MOISTURE STARVED AND DIABATIC COOLING WILL HAVE A TOUGH
TIME MOISTENING THE AIR MASS WITH PRECIPITABLE WATER CONTENT OF
ONLY A QUARTER INCH.
SUNDAY THROUGH TUESDAY...A SECONDARY SHORT WAVE DIGS INTO THE GREAT
BASIN ON SUNDAY NIGHT. THIS WILL BE FOLLOWED BY ANOTHER DIGGING
WAVE FROM ALBERTA ON TUESDAY THAT REINFORCES THE COLDER AIR MASS
ACROSS THE REGION. NEITHER OF THESE FEATURES WILL HAVE MUCH
MOISTURE TO WORK WITH...BUT DOES KEEP THE AIR MASS COOL AND
UNSETTLED WITH A CHANCE OF MOUNTAIN SNOW SHOWERS.
APPEARS THAT NEXT WEDNESDAY WILL BE DRY AS TRANSITORY RIDGE MOVES
ACROSS THE REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1053 AM MST THU FEB 23 2012
STRONG GUSTY WINDS HAVE DEVELOPED OVER THE SOUTHERN THIRD OF THE
FORECAST AREA...WHILE DECREASING SOMEWHAT OVER THE NORTH...AS A COLD
FRONT PUSHES SOUTHWARD. SNOW HAS ALSO DEVELOPED OVER THE SOUTHERN
MOUNTAINS AND IN SOME HIGHER VALLEY AREAS. WHILE SNOW HAS DIMINISHED
OVER THE NORTH...SNOW SHOWERS WILL CONTINUE THROUGH THE DAY OVER ALL
MOUNTAIN AREAS. THEREFORE AREAS OF MVFR/IFR CIGS/VIS...AND TURBULENT
MIXING WILL PERSIST THROUGH THE DAY OVER THE MOUNTAIN AREAS. LOW
LEVEL WIND SHEAR WILL ALSO BE POSSIBLE IN SOME VALLEY AREAS AS LOCAL
WINDS DIMINISH NEAR THE SURFACE. GRADUAL IMPROVEMENT IS EXPECTED
LATE THIS AFTERNOON THROUGH THIS EVENING. OTHERWISE VFR CONDITIONS
EXPECTED AT THE LOWER VALLEY SITES OF WESTERN COLORADO AND EASTERN
UTAH...WITH VFR EVERYWHERE BY LATE THIS EVENING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 2 PM MST THIS AFTERNOON FOR COZ012.
WIND ADVISORY UNTIL 6 PM MST THIS EVENING FOR COZ020>022.
WINTER STORM WARNING UNTIL 2 PM MST THIS AFTERNOON FOR
COZ010.
UT...WIND ADVISORY UNTIL 6 PM MST THIS EVENING FOR UTZ022-029.
&&
$$
UPDATE...EH
SHORT TERM...MC
LONG TERM....PF
AVIATION...EH
AREA FORECAST DISCUSSION...UPDATED FOR AVIATION
NWS PEACHTREE CITY GA
100 PM EST THU FEB 23 2012
.UPDATE...
CURRENT SATELLITE ANALYSIS SHOWS SCATTERED CLOUDS IN NORTH AND
CENTRAL GEORGIA AND A MORE BROKEN TO OVERCAST CLOUD DECK IN
COLUMBUS...EAST INTO MACON. ADJUSTED THE SKY GRIDS TO REPRESENT
THIS. CURRENT SURFACE DEWPOINTS WERE HIGHER THAN FORECAST. AS
SUCH...POPULATED THE GRIDS WITH THE CURRENT 12Z RUC DEWPOINTS THAT
WERE MORE REPRESENTATIVE OF CURRENT OBSERVATIONS AND TRENDS. THIS
MEANT THAT SOME AREAS SAW AN INCREASE OF 5 DEGREES OR MORE IN
DEWPOINT TEMPS. THE NAM SEEMS TO BE UNREALISTICALLY DRYING US OUT
THIS AFTERNOON...AS SUCH BELIEVE THAT THE 06Z NAM MIGHT BE UNDER
REPRESENTING THE CHANCE OF THUNDER. WILL WAIT FOR 12Z GUIDANCE TO
BETTER PIN DOWN THUNDERSTORMS THIS AFTERNOON...EVENING AND INTO
THE OVERNIGHT HOURS. ALSO ADJUSTED THE TEMPS TO BETTER REPRESENT
CURRENT WARMING TRENDS.
ARG
&&
.SHORT TERM /TODAY THROUGH SATURDAY NIGHT/...
/ISSUED 411 AM EST THU FEB 23 2012/
EXPECT TO REMAIN STORM FREE TODAY WITH AREA BETWEEN SYSTEMS.
MODELS DIFFER SLIGHTLY WITH TIMING AND STRENGTH OF NEXT FRONTAL
SYSTEM. THE FASTER AND MORE AGGRESSIVE GFS MODEL PUSHES A COLD
FRONT INTO NW GA SHORTLY AFTER MIDNIGHT TONIGHT...WHILE NAM AND
ECMWF HOLD OFF UNTIL NEARLY 6-7 AM FRIDAY MORNING. PREFER A BLEND
IN THE MORE AGGRESSIVE GFS AND ECMWF MODELS... AS BOTH MODELS SHOW
A GREATER POTENTIAL FOR MORE WIDESPREAD SHOWER AND THUNDERSTORM
ACTIVITY AHEAD OF THE COLD FRONT...WITH STRONGER UPPER SUPPORT
DIGGING SLIGHTLY FURTHER SOUTH WHILE 600-1200 MUCAPE NOSE INTO
CENTRAL AND NORTH GA LATER THIS EVENING. THIS COUPLED WITH AMPLE
DEEP-LAYER SHEAR COURTESY OF A 50+KT LOW LEVEL SWLY JET SUGGEST
THE POTENTIAL FOR ISOLATED STRONG TO SEVERE STORMS LATER THIS
EVENING AND POSSIBLY CONTINUING OVERNIGHT. SPC HAS NORTH AND PARTS
OF WEST CENTRAL GA IN A SLIGHT RISK AREA FOR TONIGHT AND DESPITE
THE FRONT MOVING INTO THE STATE DURING THE OVERNIGHT HOURS...
SUSPECT LARGE SCALE ASCENT...DEEP- LAYER SHEAR AND FRONTAL FORCING
WILL BE SUFFICIENT FOR ISOLATED SEVERE STORM DEVELOPMENT IN THE
SLIGHT RISK AREA. THE GREATER SEVERE STORM THREAT SEEMS TO BE
BETWEEN 10 PM THIS EVENING AND 6 AM FRIDAY MORNING...AND MAINLY
NORTH OF A LA GRANGE TO ATHENS LINE. ALTHOUGH LARGE HAIL AND
DAMAGING WINDS FROM BOWING STORMS WILL LIKELY BE THE MAIN THREATS
TONIGHT... HIGH 200+ HELICITY VALUES ALSO SUGGEST THE POTENTIAL
FOR A FEW TORNADOES. THE THUNDERSTORM THREAT SHOULD PUSH SOUTH AND
EAST OF THE AREA BY FRIDAY AFTERNOON...ALTHOUGH CLOUDS AND
ISOLATED LIGHT RAIN SHOWERS MAY LINGER THROUGH FRIDAY AFTERNOON AS
THE AXIS OF THE LONG-WAVE UPPER TROUGH DOES NOT PUSH EAST OF THE
STATE UNTIL FRIDAY EVENING. CLEARING...BREEZY AND COOLER
CONDITIONS ARE ON TAP FOR FRIDAY NIGHT AS HIGH PRESSURE BUILDS IN
FROM THE WNW. MOS GUIDANCE NUMBERS WERE FAIRLY CLOSE AND
REASONABLE...SO TOOK A BLEND THROUGH THE SHORT TERM.
LONG TERM /SATURDAY THROUGH WEDNESDAY/...
/ISSUED 411 AM EST THU FEB 23 2012/
STILL HOLDING ONTO A DRY FORECAST FOR SATURDAY... BUT SUNDAY IS
LOOKING WETTER AS BOTH GFS AND ECMWF ARE SHOWING A BAJA UPPER LOW
FINALLY KICKING EAST AND TRAVERSING THE STATE ON SUNDAY. THIS FEATURE
WILL ENHANCE ISENTROPIC LIFT AND SPREAD RAIN SHOWERS INTO AT LEAST
SOUTH AND CENTRAL GA BY EARLY SUNDAY AFTERNOON. BOTH MODELS SHOW A
WEDGE OF COOL AIR BEING OVERRUN BY A MOIST SOUTHERLY MID LEVEL
FLOW... RESULTING IN A STABLE RAIN SUNDAY AND SUNDAY NIGHT. PREFER
THE DRIER GFS SOLUTION FOR MONDAY AS THIS UPPER SHORT WAVE PUSHES
EAST AND GIVES THE AREA A BREAK. THIS BEFORE ANOTHER FRONTAL
SYSTEM SPREADS A CHANCE OF SHOWERS INTO THE AREA BEGINNING TUESDAY
AND THEN ISOLATED THUNDERSTORMS ON WEDNESDAY JUST AHEAD OF THE
COLD FRONT THAT GFS PUSHES ACROSS THE AREA BY EARLY WEDNESDAY
EVENING.
39
AVIATION...
18Z UPDATE...
VFR CONDITIONS AT THIS TIME WITH A BREEZY SOUTHWEST FLOW. EXPECT
MVFR CIGS AFTER 04Z AS MOISTURE CONTINUES TO PUMP INTO THE STATE IN
ADVANCE OF THE APPROACHING COLD FRONT. THE NAM AND GFS MODELS HAVE
SLOWED THE FRONTAL PASSAGE THROUGH ATL TO AROUND 15Z. EXPECT TSTMS
LIKELY AFTER 09Z WITH LINGERING SHOWERS JUST BEHIND THE FRONT. A
BREEZY WEST TO NORTHWEST FLOW WITH DECREASING CLOUDS WILL PREVAIL ON
FRIDAY AFTER 15Z.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM ON ALL ELEMENTS.
16
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 76 57 63 35 / 10 60 60 10
ATLANTA 75 54 59 35 / 10 70 50 10
BLAIRSVILLE 68 51 55 29 / 10 70 40 10
CARTERSVILLE 75 52 60 32 / 10 70 40 10
COLUMBUS 76 58 62 38 / 10 60 60 10
GAINESVILLE 72 54 62 34 / 10 70 50 10
MACON 78 62 65 36 / 10 50 60 20
ROME 75 52 61 32 / 10 70 40 10
PEACHTREE CITY 76 53 60 31 / 10 60 50 10
VIDALIA 81 64 69 42 / 10 40 60 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
26
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
601 PM EST THU FEB 23 2012
.SYNOPSIS...
ISSUED AT 415 PM EST THU FEB 23 2012
A STRONG WINTER STORM WILL MOVE THROUGH THE LOWER GREAT LAKES
TONIGHT INTO FRIDAY. HEAVY SNOWFALL IS EXPECTED LATER TONIGHT INTO
FRIDAY MORNING. LAKE EFFECT SNOW SHOWERS WILL FOLLOW FRIDAY
AFTERNOON INTO SATURDAY AFTERNOON. HIGH PRESSURE WILL CLEAR THE
SKIES FOR SUNDAY BEFORE ANOTHER SYSTEM MOVES ACROSS THE AREA WITH
WARMER TEMPERATURES MONDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 415 PM EST THU FEB 23 2012
THE PRIMARY ISSUE IS THE WINTER STORM HEADING TOWARD THE SOUTHERN
GREAT LAKES FOR LATER TONIGHT INTO FRIDAY. THERE IS ALSO AN ISSUE
WITH LAKE EFFECT SNOW FRIDAY AFTERNOON INTO SATURDAY.
MY CURRENT THINKING IS THERE WILL BE SNOW...HEAVY AT TIMES LATE
THIS EVENING INTO MID MORNING FRIDAY. A FEW FLASHES OF LIGHTNING
ARE NOT OUT OF THE QUESTION TONIGHT EITHER. THE HEAVIEST SNOWFALL
WILL BE NEAR AND SOUTH OF INTERSTATE 96.
THERE HAS BEEN A CURIOUS SHIFT IN THE MODELS OVER THE PAST 12
HOURS WITH THE TIMING OF THE SYSTEM. MY EARLIER THINKING BROUGHT
THE HEAVY SNOW INTO THE AREA AFTER MIDNIGHT AND ENDED IT BY MID
MORNING. HOWEVER THE 18Z NAM... THE 16Z HRRR AND 12Z ECMWF SUGGEST
THE HEAVIEST SNOWFALL MAY WELL BE MOSTLY DURING THE DAY FRIDAY.
WHAT SEEMS TO BE HAPPENING IS THE WARM ADVECTION BURST OF
PRECIPITATION WILL LARGELY TRACK EAST NORTHEAST NEAR AND SOUTH OF
INTERSTATE 94 TONIGHT. THEN THE DEFORMATION BAND WITH THE UPPER
LOW IS WHAT WILL BRING THE HEAVY SNOW TO THE CENTRAL PARTS OF THE
CWA. WITH THIS LATEST THINKING THE HEAVIEST SNOW WOULD BE FROM 05
AM THROUGH 1 PM INSTEAD OF 9 PM TILL 7 AM AS EARLIER THROUGH.
THE DEEP UPPER LOW OF COURSE MEANS STRONGER FORCING...BETTER
FGEN... AND INCREASED NEG EPV. THUS OUR IDEA OF HEAVY SNOW STILL
LOOKS GOOD...MAYBE EVEN BETTER BUT JUST SLOWER. I ADDED THUNDER
DUE TO THE NEG EPV...STRONG FGEN AND THE TQ INDEX BEING OVER 15
(SUGGEST ELEVATED THUNDERSTORMS). ALSO SUPPORTING HEAVY SNOW IS
STRONG LIFT IN THE DGZ. ONLY ISSUE THERE IS THE DGZ IS ABOVE 10000
FT AGL AND IT NARROW. ON THE OTHER HAND THE DGZ DOES FALL TO BELOW
1000O FT AFTER 06Z AND GETS DEEPER. THERE IS ANOTHER AREA OF
ENHANCED LIFT IN THE DGZ TOWARD 12Z. ALL OF THIS SUPPORTS THE IDEA
OF ENHANCED SNOWFALL ACROSS THE CENTRAL CWA WITH THIS SYSTEM.
THE ECMWF 12Z AND 18Z NAM HAVE INCREASED THE QPF (WHILE DELAYING
TIMING 6 TO 12 HOURS). SO THE BOTTOM LINE IS MIXED RAIN AND SNOW
THIS EVENING OVER THE SOUTHERN 1/3 OF THE CWA. THEN SNOW SPREADING
NORTH AND EAST AFTER MIDNIGHT WITH SNOW HEAVY AT TIMES CENTRAL CWA
FRIDAY MORNING. WE ARE EXPECTING 6 TO 10 INCHES IN THE HEAVIEST
SNOW AREA.
AFTER THE UPPER UPPER LOW MOVES EAST OF THE AREA FRIDAY
AFTERNOON... THAT ALLOWS THE BETTER COLD ADVECTION TO BEGIN. WITH
CYCLONIC FLOW... 850 MB TMPS BELOW -10C MOVING IN WITH DEEP
MOISTURE ON NORTHWEST WINDS... LAKE EFFECT SNOW DEVELOPS AND
CONTINUES THROUGH THE NIGHT. THE BEST SNOWFALL FOR THIS WILL BE
DURING THE OVERNIGHT HOURS. ANOTHER 2 TO 4 INCHES ARE EXPECTED
WITH THAT IN THE TYPICAL NW FLOW AREAS. THIS TIME THROUGH THE AIR
TEMP WILL BE BELOW FREEZING SO THIS SNOW WILL BE MORE OF A FLUFFY
SNOW. ONCE AGAIN THERE IS GOOD LIFT IN THE DGZ BUT THE BEST LIFT
IS ACTUALLY BELOW THE DGZ SO THIS WILL NOT BE AS FLUFFY AS SOME
LAKE EFFECT EVENTS HAVE BEEN.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 415 PM EST THU FEB 23 2012
LINGERING LAKE EFFECT SNOW SHOWERS SATURDAY MORNING WILL END IN THE
AFTERNOON AS UPPER LEVEL FLOW BECOMES ANTICYCLONIC. DRY WEATHER IS
FORECAST SATURDAY NIGHT AND SUNDAY WITH UPPER RIDGING IN PLACE.
AT THIS TIME WE WILL MAINTAIN VERY LOW POPS FOR SUNDAY NIGHT INTO
MONDAY AS WEAK LOW PRESSURE MOVES ACROSS THE LAKE SUPERIOR REGION.
HOWEVER IT IS NOTED THAT OVERALL MEDIUM RANGE GUIDANCE TRENDS KEEP
LIGHT QPF TIED TO THIS SYSTEM NORTH OF OUR FCST AREA... SO FUTURE
SHIFTS MAY BE ABLE TO GO WITH A DRY FCST SUNDAY NIGHT/MONDAY.
A BETTER CHC FOR PCPN SHOULD COME FOR THE MIDDLE PORTION OF NEXT
WEEK AS A SOUTHERN PLAINS LOW TRACKS ENE INTO THE LOWER GREAT LAKES
REGION BY TUESDAY NIGHT/WEDNESDAY. LIGHT PCPN MAY ARRIVE AS EARLY AS
TUESDAY PRECEDING THAT SYSTEM... BUT THE BETTER CHC FOR PCPN SHOULD
HOLD OFF UNTIL TUESDAY NIGHT AND WEDNESDAY AS SUGGESTED BY 12Z ECMWF
GUIDANCE.
TRENDED THE MAX TEMP FCST A BIT MILDER FOR WEDNESDAY WITH POTENTIAL
FOR A RAIN/SNOW MIX. TEMPS SHOULD AVG NEAR TO SLIGHTLY ABOVE NORMAL
THROUGH THE LONG RANGE FCST PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 600 PM EST THU FEB 23 2012
MAIN CHANGES TO THIS UPDATE WERE TO DELAY TIMING OF RAIN AND SNOW
AND TO INCREASE NORTHEAST WINDS OVERNIGHT. WE STILL EXPECT LIFR
CONDITIONS AREAWIDE RELATED TO MODERATE/HEAVY SNOW AND INCREASING
WINDS. THUNDER COULD EVEN ACCOMPANY PRECIPITATION AT THE
KAZO...KBTL...KJXN TERMINALS ALONG THE I-94 CORRIDOR. A BRIEF
PERIOD OF FREEZING RAIN IS POSSIBLE DURING THE CHANGEOVER...BUT WE
DO NOT EXPECT SIGNIFICANT ICING OVERALL. THIS LOOKS LIKE A PROLONGED
EVENT...SO KEPT IFR CONDITIONS AFTER 12Z.
&&
.MARINE...
ISSUED AT 415 PM EST THU FEB 23 2012
I HAVE ISSUED A SMALL CRAFT ADVISORY DUE TO THE INCREASING NORTH
WINDS TONIGHT THROUGH SATURDAY AFTERNOON. WINDS SHOULD INCREASE TO
15 TO 25 KNOTS OVERNIGHT AND CONTINUE INTO SATURDAY BEFORE
DIMINISHING DURING THE LATE AFTERNOON.
&&
.HYDROLOGY...
ISSUED AT 415 PM EST THU FEB 23 2012
THERE ARE NO WARNINGS OR ADVIOSRIES IN EFFECT FOR AREA RIVERS OR
STREAMS. TEMPERATURES ARE NOT EXPECTED TO GET COLD ENOUGH FOR ICE
JAMS TO BE AN ISSUE. METLING OF THE SNOW THAT FALLS SHOULD BE SLOW
ENOUGH TO NOT BE MUCH OF AN ISSUE EITHER.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER STORM WARNING UNTIL NOON EST FRIDAY FOR MIZ056>059-
064>067-071>074.
WINTER WEATHER ADVISORY UNTIL NOON EST FRIDAY FOR MIZ044>046-
050>052.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST SATURDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM....LAURENS
AVIATION...TJT
MARINE...WDM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
425 PM EST THU FEB 23 2012
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 423 PM EST THU FEB 23 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
FROM MANITOBA AND NRN ONTARIO INTO THE SRN PLAINS. A VIGOROUS
SHORTWAVE TROUGH MOVING THROUGH SRN NEBRASKA SUPPORTED A BAND OF
MODERATE TO HEAVY SNOW OVER SE SD INTO NRN IA AND RAIN TO THE EAST.
AN UPSTREAM SHRTWV NEAR LAKE WINNIPEG WAS BRINGING MAINLY JUST LIGHT
SNOW OR FLURRIES IN SRN MANITOBA AND NW ONTARIO. AT THE SFC...A 990
MB LOW WAS LOCATED OVER SE MO WHILE A WEAKER 1002 MB LOW MOVING
THROUGH SE MANITOBA. A WEAK TROUGH EXTENDED FROM WEST TO EAST ACROSS
UPPER MI LEAVING VERY LIGHT WINDS OVER THE AREA. WITH PLENTY OF LOW
LEVEL MOISTURE IN PLACE THE WEAK NNE FLOW COMBINED WITH 850 MB TEMPS
AROUND -9C WAS ENOUGH TO SUPPORT SOME LIGHT SNOW SHOWERS INTO N
CNTRL UPPER MI.
EXPECT AREAS OF LIGHT SNOW SHOWERS OR FLURRIES TO PERSIST INTO THIS
EVENING CNTRL AND WEST WITH THE TROUGH OVER THE AREA AND WEAK FLOW
OFF OF LAKE SUPERIOR. ANY ACCUMULATIONS SHOULD ONLY AMOUNT TO A
TRACE OR A FEW TENTHS. AS THE MANITOBA SHRTWV MOVES TOWARD THE AREA
LATE TONIGHT INTO FRIDAY...MID LEVEL QVECTOR CONV ASSOCIATED WITH
THIS FEATURES WILL SUPPORT AN EXPANDING AREA OF LIGHT SNOW FROM NE
MN INTO WRN LAKE SUPERIOR AND WEST UPPER MI. SINCE THE NNW WINDS LOW
LEVEL WINDS FCST REMAIN RELATIVELY LIGHT THERE IS STILL SIGNIFICANT
UNCERTAINTY REGARDING THE LAKE ENHANCED SNOW POTENTIAL INTO WEST
UPPER MI AS THE HIGH RES MODELS SHOW DIFFERING SCENARIOS. THE BEST
CHANCE FOR SNOW OVER THE WEST IS EXPECTED DURING THE AFTERNOON AS
THE SHORTWAVE APPROACHES AND COLDER AIR MOVES IN WITH 850 MB TEMPS
DROP TO NEAR -12C. IF STRONGER LOW LEVEL CONV OR ONSHORE WINDS
DEVELOP SNOW AMOUNTS OF A COUPLE INCHES WILL BE POSSIBLE BY EVENING.
SCT -SHSN SHOULD ALSO DEVELOP OVER THE REST OF NRN UPPER MI AS NRLY
WINDS INCREASE. HOWEVER...SINCE THE DEEPER MOISTURE REMAINS TO THE
WEST...ONLY CHANCE POPS WERE INCLUDED.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 423 PM EST THU FEB 23 2012
FRI NGT...A CYC NLY FLOW WL DOMINATE THE UPR GRT LKS AS A SHRTWV
DIGGING SEWD THRU MN MAINTAINS LOWER HGTS/HIER MID LVL RH OVER THE
UPR LKS. ALTHOUGH THE FCST H85 TEMPS IN THE -12C TO -14C ARE NOT
PARTICULARLY COLD...OPTED TO MAINTAIN LIKELY POPS IN AREAS FAVORED
BY THE NNW LLVL FLOW GIVEN THE DEEP MSTR PROFILE. WENT WITH THE
HIER POPS OVER THE W CLOSER TO THE TRACK OF THE MN DISTURBANCE.
SAT...EXPECT LINGERING LES IN THE MRNG TO DIMINISH WITH THE APRCH OF
SHRTWV RDG IN PROGRESSIVE FLOW ALF AND ARRIVAL OF RISING H5 UP TO
100M BTWN 12Z-24Z/SFC HI PRES IN THE WAKE OF DEPARTING SHRTWV.
ALTHOUGH FCST LLVL NW FLOW IS FAVORABLE FOR LES IN AREAS E OF MQT...
MODELS CONSISTENTLY SHOW DRY AIR IN ONTARIO PASSING OVER ERN LK SUP
AND LIMITING SN CHCS OVER THE ERN CWA. SO CUT POPS/SN AMOUNTS SHOWN
IN PREVIOUS FCSDT.
SAT NGT...ALTHOUGH A FEW -SHSN MAY LINGER NEAR LK SUP IN THE EVNG...
BACKING FLOW TO THE SSW OVERNGT WITH PASSAGE OF RDG AXIS TO THE E
AND APRCH OF STRONG SHRTWV/SFC LO THRU THE NRN PLAINS WL PUSH ANY
REMAINING -SHSN OUT INTO THE OPEN LAKE. WITH SOME CLRG/LGT WINDS
UNDER THE RDG AXIS/PWAT ARND 0.15 INCH...TEMPS OVER THE INTERIOR MAY
FALL SHARPLY IN THE EVNG BEFORE THICKENING HI/MID CLDS RETURN LATE
WITH DVLPG ISENTROPIC ASCENT AHEAD OF THE INCOMING SHRTWV/SFC LO AND
CAUSE READINGS TO RISE LATER. TENDED TOWARD THE LO END OF GUIDANCE
FOR MIN TEMPS IN THIS AREA WITH A NON DIURNAL TEMP TREND.
SUN/SUN NGT...MODELS HAVE TRENDED A BIT FASTER WITH THE INCOMING
FCST LO PRES AS SUPPORTING SHRTWV IS FCST TO SHEAR OUT AS IT MOVES
INTO CONFLUENCE ZN BTWN MEAN RDG OVER THE SE CONUS AND PERSISTENT
WNW FLOW ALF OVER NE CAN ON SW FLANK OF CLOSED LO NEAR THE DAVIS
STRAIT. ALTHOUGH THE 12Z GFS SHOWS A MORE SHEARED OUT/WEAKER
DISTURBANCE WHILE THE CNDN MODEL DEPICTS A DEEPER SYS...VARIOUS
GUIDANCE IS IN GOOD AGREEMENT SHOWING THE LO PRES TRACK ACRS THE NRN
TIER OF THE CWA/SRN LK SUP. THIS TRACK SHOULD MINIMIZE THE THREAT OF
SGNFT SN ACCUM OVER THE FA WITH MORE PERSISTENT DEEPER FGEN UNDER
DEFORMATION ZN PASSING TO THE W AND N AND POTENTIAL DRY SLOTTING
ESPECIALL OVER THE SRN TIER CLOSER TO SUPPORTING JET CORE AXIS.
HOWEVER...COMBINATION OF FAIRLY SHARP UPR DVGC IN LEFT EXIT OF
SUPPORTING H3 JET MAX/FAIRLY VIGOROUS ISENTROPIC ASCENT SHOWN ON THE
285K SFC /ABOUT H75/ IN THE WAD PATTERN N OF ATTENDANT WARM FNT/DEEP
LYR QVECTOR CNVGC WARRANT FCST HI LIKELY POPS SPREADING IN BY AFTN.
GIVEN FCST H7 SPECIFIC HUMIDITY OF 2 G/KG...SUSPECT UP TO 2 TO 4
INCHES OF SN MAY FALL OVER THE NW CWA ON SUN...ESPECIALLY SINCE GFS
FCST SDNGS SHOW SHARP OMEGA WITHIN THE DGZ IN THAT AREA. EXPECT THE
SYNOPTIC SCALE PCPN TO DIMINISH TO LES W-E BY EARLY MON MORNING
WITH LARGE SCALE QVECTOR DVGC/DRYING FOLLOWING THE SHRTWV/SFC LO.
SINCE THERE IS A POTENTIAL FOR ADVY SN WITH THIS DISTURBANCE...OPTED
TO RETAIN MENTION IN HWO.
IN THE EXTENDED RANGE...SOME LES IS LIKELY ON MON UNDER THE MOIST
NNW FLOW LEFT IN THE WAKE OF THE DEPARTING LO THRU SE CAN AND WITH
H85 TEMPS PROGGED TO DIP AS LO AS -15C. THE ARRIVAL OF A HI PRES RDG
WL BRING QUIET WX ON TUE. ANOTHER DISTURBANCE/SFC LO MOVING IS FCST
TO MOVE THRU THE OH VALLEY ON WED. THERE HAS BEEN CONSIDERABLE MODEL
DISAGREEMENT ON THE TRACK OF THIS SHRTWV...SO RELIED ON THE
CONSENSUS OF THE MODELS FOR THE FORECAST IN THAT PERIOD. BEST SHOT
FOR ANY ACCOMPANYING SN WL BE OVER THE S. WITH HI PRES FOLLOWING
THIS SYSTEM NEXT THU...EXPECT A DRYING TREND THEN. SINCE THE
PREVAILING ZONAL FLOW ALF THRU THE EXTENDED PERIOD WL LIMIT ARCTIC
AIR INTRUSION INTO THE CONUS...EXPECT ABV NORMAL TEMPS TO PERSIST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1239 PM EST THU FEB 23 2012
LIGHT NORTHERLY WINDS ARE EXPECTED THROUGH THE FCST PERIOD AS A WEAK
INVERTED TROUGH REMAINS TO THE WEST AND LOW PRES MOVES NORTHEAST
FROM MISSOURI TO THE LOWER GREAT LAKES. MOIST LOW LEVELS WILL KEEP
CONDITIONS MVFR AT ALL TAF SITES THROUGH THE FCST PERIOD AND COULD
CAUSE SOME UPSLOPE FLURRIES AT THE TAF SITES BUT WITH NO RESTRICTION
IN VSBY. LATE TONIGHT...COLDER AIR WILL ARRIVE AND LAKE EFFECT SNOW
SHOWERS WILL INCREASE AT KCMX AND KIWD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 423 PM EST THU FEB 23 2012
NRLY WINDS INCREASING INTO THE 15 TO 25 KT RANGE ARE EXPECTED LATE
FRIDAY INTO FRIDAY NIGHT AS THE GRADIENT INCREASES IN THE WAKE OF
LOW PRESSURE MOVING TOWARD THE SRN GREAT LAKES. A LOW PRESSURE
SYSTEM MOVING THROUGH THE UPPER GREAT LAKES SUNDAY INTO MONDAY WILL
ALSO BRING A PERIOD OF STRONGER WINDS. SE WINDS TO 30 KT ARE
EXPECTED IN ADVANCE OF THE LOW ON SUN. AS THE LOW MOVES TO THE EAST
OF THE AREA MONDAY NORTH TO NORTHWEST WINDS OF 20 TO 30 KT ARE ALSO
EXPECTED.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
416 PM EST THU FEB 23 2012
.SYNOPSIS...
ISSUED AT 415 PM EST THU FEB 23 2012
A STRONG WINTER STORM WILL MOVE THROUGH THE LOWER GREAT LAKES
TONIGHT INTO FRIDAY. HEAVY SNOWFALL IS EXPECTED LATER TONIGHT INTO
FRIDAY MORNING. LAKE EFFECT SNOW SHOWERS WILL FOLLOW FRIDAY
AFTERNOON INTO SATURDAY AFTERNOON. HIGH PRESSURE WILL CLEAR THE
SKIES FOR SUNDAY BEFORE ANOTHER SYSTEM MOVES ACROSS THE AREA WITH
WARMER TEMPERATURES MONDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 415 PM EST THU FEB 23 2012
THE PRIMARY ISSUE IS THE WINTER STORM HEADING TOWARD THE SOUTHERN
GREAT LAKES FOR LATER TONIGHT INTO FRIDAY. THERE IS ALSO AN ISSUE
WITH LAKE EFFECT SNOW FRIDAY AFTERNOON INTO SATURDAY.
MY CURRENT THINKING IS THERE WILL BE SNOW...HEAVY AT TIMES LATE
THIS EVENING INTO MID MORNING FRIDAY. A FEW FLASHES OF LIGHTNING
ARE NOT OUT OF THE QUESTION TONIGHT EITHER. THE HEAVIEST SNOWFALL
WILL BE NEAR AND SOUTH OF INTERSTATE 96.
THERE HAS BEEN A CURIOUS SHIFT IN THE MODELS OVER THE PAST 12
HOURS WITH THE TIMING OF THE SYSTEM. MY EARLIER THINKING BROUGHT
THE HEAVY SNOW INTO THE AREA AFTER MIDNIGHT AND ENDED IT BY MID
MORNING. HOWEVER THE 18Z NAM... THE 16Z HRRR AND 12Z ECMWF SUGGEST
THE HEAVIEST SNOWFALL MAY WELL BE MOSTLY DURING THE DAY FRIDAY.
WHAT SEEMS TO BE HAPPENING IS THE WARM ADVECTION BURST OF
PRECIPITATION WILL LARGELY TRACK EAST NORTHEAST NEAR AND SOUTH OF
INTERSTATE 94 TONIGHT. THEN THE DEFORMATION BAND WITH THE UPPER
LOW IS WHAT WILL BRING THE HEAVY SNOW TO THE CENTRAL PARTS OF THE
CWA. WITH THIS LATEST THINKING THE HEAVIEST SNOW WOULD BE FROM 05
AM THROUGH 1 PM INSTEAD OF 9 PM TILL 7 AM AS EARLIER THROUGH.
THE DEEP UPPER LOW OF COURSE MEANS STRONGER FORCING...BETTER
FGEN... AND INCREASED NEG EPV. THUS OUR IDEA OF HEAVY SNOW STILL
LOOKS GOOD...MAYBE EVEN BETTER BUT JUST SLOWER. I ADDED THUNDER
DUE TO THE NEG EPV...STRONG FGEN AND THE TQ INDEX BEING OVER 15
(SUGGEST ELEVATED THUNDERSTORMS). ALSO SUPPORTING HEAVY SNOW IS
STRONG LIFT IN THE DGZ. ONLY ISSUE THERE IS THE DGZ IS ABOVE 10000
FT AGL AND IT NARROW. ON THE OTHER HAND THE DGZ DOES FALL TO BELOW
1000O FT AFTER 06Z AND GETS DEEPER. THERE IS ANOTHER AREA OF
ENHANCED LIFT IN THE DGZ TOWARD 12Z. ALL OF THIS SUPPORTS THE IDEA
OF ENHANCED SNOWFALL ACROSS THE CENTRAL CWA WITH THIS SYSTEM.
THE ECMWF 12Z AND 18Z NAM HAVE INCREASED THE QPF (WHILE DELAYING
TIMING 6 TO 12 HOURS). SO THE BOTTOM LINE IS MIXED RAIN AND SNOW
THIS EVENING OVER THE SOUTHERN 1/3 OF THE CWA. THEN SNOW SPREADING
NORTH AND EAST AFTER MIDNIGHT WITH SNOW HEAVY AT TIMES CENTRAL CWA
FRIDAY MORNING. WE ARE EXPECTING 6 TO 10 INCHES IN THE HEAVIEST
SNOW AREA.
AFTER THE UPPER UPPER LOW MOVES EAST OF THE AREA FRIDAY
AFTERNOON... THAT ALLOWS THE BETTER COLD ADVECTION TO BEGIN. WITH
CYCLONIC FLOW... 850 MB TMPS BELOW -10C MOVING IN WITH DEEP
MOISTURE ON NORTHWEST WINDS... LAKE EFFECT SNOW DEVELOPS AND
CONTINUES THROUGH THE NIGHT. THE BEST SNOWFALL FOR THIS WILL BE
DURING THE OVERNIGHT HOURS. ANOTHER 2 TO 4 INCHES ARE EXPECTED
WITH THAT IN THE TYPICAL NW FLOW AREAS. THIS TIME THROUGH THE AIR
TEMP WILL BE BELOW FREEZING SO THIS SNOW WILL BE MORE OF A FLUFFY
SNOW. ONCE AGAIN THERE IS GOOD LIFT IN THE DGZ BUT THE BEST LIFT
IS ACTUALLY BELOW THE DGZ SO THIS WILL NOT BE AS FLUFFY AS SOME
LAKE EFFECT EVENTS HAVE BEEN.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 415 PM EST THU FEB 23 2012
LINGERING LAKE EFFECT SNOW SHOWERS SATURDAY MORNING WILL END IN THE
AFTERNOON AS UPPER LEVEL FLOW BECOMES ANTICYCLONIC. DRY WEATHER IS
FORECAST SATURDAY NIGHT AND SUNDAY WITH UPPER RIDGING IN PLACE.
AT THIS TIME WE WILL MAINTAIN VERY LOW POPS FOR SUNDAY NIGHT INTO
MONDAY AS WEAK LOW PRESSURE MOVES ACROSS THE LAKE SUPERIOR REGION.
HOWEVER IT IS NOTED THAT OVERALL MEDIUM RANGE GUIDANCE TRENDS KEEP
LIGHT QPF TIED TO THIS SYSTEM NORTH OF OUR FCST AREA... SO FUTURE
SHIFTS MAY BE ABLE TO GO WITH A DRY FCST SUNDAY NIGHT/MONDAY.
A BETTER CHC FOR PCPN SHOULD COME FOR THE MIDDLE PORTION OF NEXT
WEEK AS A SOUTHERN PLAINS LOW TRACKS ENE INTO THE LOWER GREAT LAKES
REGION BY TUESDAY NIGHT/WEDNESDAY. LIGHT PCPN MAY ARRIVE AS EARLY AS
TUESDAY PRECEDING THAT SYSTEM... BUT THE BETTER CHC FOR PCPN SHOULD
HOLD OFF UNTIL TUESDAY NIGHT AND WEDNESDAY AS SUGGESTED BY 12Z ECMWF
GUIDANCE.
TRENDED THE MAX TEMP FCST A BIT MILDER FOR WEDNESDAY WITH POTENTIAL
FOR A RAIN/SNOW MIX. TEMPS SHOULD AVG NEAR TO SLIGHTLY ABOVE NORMAL
THROUGH THE LONG RANGE FCST PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1230 PM EST THU FEB 23 2012
CONDITIONS HAVE IMPROVED TO MVFR TO VFR AT SOME OF THE TERMINALS
EARLY THIS AFTERNOON WHERE FOG HAS DISSIPATED... BUT SOME PATCHY IFR
TO LIFR REMAINS AT KAZO AND KBTL DUE TO LOW CLOUDS AND FOG. EXPECT
VARIABLE CONDITIONS TO CONTINUE THIS AFTN DUE TO PATCHY FOG.
CONDITIONS WILL DETERIORATE RAPIDLY FROM IFR TO LIFR THEN VLIFR FROM
SOUTH TO NORTH MID TO LATE EVENING AS HEAVY SNOW DEVELOPS. LIFR TO
MAINLY VLIFR CONDITIONS OVERNIGHT WILL GRADUALLY IMPROVE TO IFR MID
TO LATE FRIDAY MORNING AS SNOW DECREASES IN INTENSITY. EAST WINDS
THIS AFTN WILL BACK TO THE NE OVERNIGHT THEN BACK TO THE NNW AND
RAMP UP FRIDAY MORNING AND EARLY AFTN.
&&
.MARINE...
ISSUED AT 415 PM EST THU FEB 23 2012
I HAVE ISSUED A SMALL CRAFT ADVISORY DUE TO THE INCREASING NORTH
WINDS TONIGHT THROUGH SATURDAY AFTERNOON. WINDS SHOULD INCREASE TO
15 TO 25 KNOTS OVERNIGHT AND CONTINUE INTO SATURDAY BEFORE
DIMINISHING DURING THE LATE AFTERNOON.
&&
.HYDROLOGY...
ISSUED AT 415 PM EST THU FEB 23 2012
THERE ARE NO WARNINGS OR ADVIOSRIES IN EFFECT FOR AREA RIVERS OR
STREAMS. TEMPERATURES ARE NOT EXPECTED TO GET COLD ENOUGH FOR ICE
JAMS TO BE AN ISSUE. METLING OF THE SNOW THAT FALLS SHOULD BE SLOW
ENOUGH TO NOT BE MUCH OF AN ISSUE EITHER.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER STORM WARNING FROM 7 PM THIS EVENING TO NOON EST FRIDAY
FOR MIZ056>059-064>067-071>074.
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO NOON EST
FRIDAY FOR MIZ044>046-050>052.
LM...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST SATURDAY
FOR LMZ844>849.
&&
$$
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM....LAURENS
AVIATION...LAURENS
MARINE...WDM
HYDROLOGY...WDM
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
342 PM CST THU FEB 23 2012
.DISCUSSION...
TONIGHT AND FRIDAY...STUBBORN LGT/MOD SNOW HAS CONTINUED OVER FAR
SW MN WHILE THE REST OF THE COVERAGE AREA HAS REMAINED DRY BUT
UNDER LOW EXTENSIVE CLOUD COVER. THE SWATH OF SNOW ALIGNS NICELY
WITH A WEAK SFC TROUGH EXTENDING NW FROM A PARENT SFC LOW OVER MO
TREKKING E INTO THE SRN OHIO VALLEY. AS THIS SYSTEM CONTINUES TO
SHIFT E OVERNIGHT...THE SNOW OVER SWRN MN WILL COME TO AN END BUT
WILL BE REPLACED BY FLURRIES/SNOW SHOWERS DURG THE DAY TMRW FOR
MAINLY CENTRAL AND ERN PORTIONS OF THE COVERAGE AREA. A CDFNT
DROPPING S FROM CENTRAL CANADA FOLLOWED BY AN UPPER LEVEL CUTOFF
LOW NUDGING THE FRONT ALONG WILL HAVE PRETTY MEAGER MOISTURE GOING
ALONG. LITTLE/NO ACCUMS ARE EXPECTED BUT HAVE KEPT POPS IN THE
20-40 PERCENT RANGE. WITH THIS FROPA WILL COME A DOSE OF CAA THAT
WILL MAKE FOR A SMALL DIURNAL RANGE FROM TNGT INTO FRI.
FRIDAY NIGHT THROUGH SUNDAY...BRIEF RESPITE FROM SENSIBLE WX COMES
FRI NIGHT THROUGH SAT AS SFC HIGH PRES ALONG WITH THE WINDWARD
SIDE OF UPPER RIDGING DROPS THROUGH THE AREA. MIN TEMPS WILL DROP
CLOSE TO OR SLIGHTLY BELOW NORMAL LEVELS FRI NIGHT THEN AMPLE
SUNSHINE DURING THE FIRST HALF OF THE DAY SAT WILL ALLOW TEMPS TO
REBOUND NICELY TO NORMAL LEVELS AS THE BACKSIDE OF THE RIDGE MOVES
ACROSS. CLOUDS WILL BE ON THE INCRS SAT NIGHT INTO SUN AS AN AREA
OF LOW PRES DROPPING INTO THE ROCKIES FROM MANITOBA PHASES WITH A
SECONDARY LOW PRES CENTER OVER THE CENTRAL PLAINS. THIS COMBINED
SYSTEM WILL THEN TRAVERSE E ACRS THE DAKOTAS INTO WRN MN WHERE IT
WILL THEN SHIFT NE TWD THE U.P. OF MICHIGAN. THE EVER-SO-SLOWLY
SHIFT OF THE TRACK TO N OF THE MPX COVERAGE AREA MEANS LESSER
EXPECTED SNOWFALL AND WITH ADDITIONAL WARMER AIR BEING ENVELOPED
INTO THE SYSTEM...PARTS OF THE TIME FROM SUN AFTN INTO SUN EVE
WILL HAVE A RAIN/SNOW MIX FOR PORTIONS OF THE AREA S OF I-94. THE
HEAVIER SNOWS MAY IMPACT NRN FRINGES OF THE COVERAGE AREA BUT SNOW
AMOUNTS WILL GENERALLY BE 3 INCHES OR LESS FROM THE SYSTEM ON
SUNDAY FOR CENTRAL-SRN MN WHILE AMOUNTS INCREASE GOING WELL N.
MONDAY THROUGH WEDNESDAY...QUITE THE INTERESTING PATTERN
DEVELOPING FOR THE MIDDLE OF THE WEEK AMONG THE MODELS. ANOTHER
BRIEF RESPITE FROM WX IS EXPECTED MON INTO TUE AS SFC HIGH PRES
AND A SHARP UPPER RIDGE AXIS PUSH OVER THE AREA. FOLLOWING THE
RIDGE...THE MODELS RAMP UP A VERY POTENT SYSTEM FOR THE MIDDLE OF
NEXT WEEK. BETWEEN THE ECMWF AND GFS...BOTH SHOW CYCLOGENESIS OVER
THE CENTRAL PLAINS THAT IS AMPLIFIED BY A NEGATIVELY-TILTED UPPER
LEVEL TROUGH AND A DIRECT MOISTURE TAP FROM THE GULF OF MEXICO.
THE TRACK OF THIS SYSTEM LOOKS TO BE SW TO NE WHILE REMAINING JUST
S OF THE MPX COVERAGE AREA. IN ADDITION...THE ECMWF SLOWS ITS
PROGRESS OF THE SYSTEM OVER IOWA WHICH WOULD GREATLY ENHANCE
SNOWFALL POTENTIAL FOR SRN MN INTO WRN WI. THERE ARE A LOT OF
FACTORS TO COME INTO PLAY...HENCE POPS KEPT ONLY IN THE 20-30
PERCENT RANGES...BUT THE EVOLUTION OF THIS SYSTEM BEARS WATCHING.
TEMPERATURES BOUNCE AROUND DURING THE FIRST HALF OF THE WEEK BUT
REMAIN NEAR TO BELOW NORMAL.
&&
.AVIATION.../18Z TAF ISSUANCE/
BIG ISSUE FOR THIS TAF PERIOD IS WHAT TO DO WITH CLOUDS.
IMPRESSIVE BAND OF SNOW OVER SE SODAK HEADING FOR CENTRAL IA AND
WILL BE MISSING ALL TAFS. SEEING PLENTY OF MID CLOUDS SPILLING
INTO THE AREA ASSOCIATED WITH THIS WAVE...BUT MORE FRUSTRATING IS
THE AMPLE MOISTURE BETWEEN 025 AND 035 THAT HAS LED TO RANDOM
CLOUD BANKS AROUND 3K FT. RH PROFILES FROM NAM/GFS/RUC SHOW THIS
MOISTURE WANING ACROSS THE AREA AFTER 00Z...SO SHOULD SEE CLOUDS
IN THIS LAYER DIMINISH AFTER SUNSET. AFTER THAT...WATCHING SWATH
OF SNOW MOVING EAST ACROSS NODAK...HAVE BEEN SOME 1/4SM VSBY SNOWS
IN NODAK...BUT HRRR REFLECTIVITY AND MODEL QPF FORECASTS ALL
SAYING THIS WILL BE DIMINISHING AS HITS MN. USED COMBO OF HRRR/RUC
THEN GFS TO TIME THIS BAND OF FORCING ACROSS THE AREA. ONLY HAVE
-SN MENTIONED AT AXN GIVEN THE UPSTREAM OBS...BUT ALL COULD SEE A
QUICK BURST OF SNOW AS IT MOVES THROUGH. WINDS HAVE BEEN A BIT
TRICKY TODAY ACROSS ERN MN/WRN WI WHERE WINDS HAVE BEEN OUT OF THE
SE OUT AHEAD OF A RIDGE AXIS. WINDS WILL QUICKLY BACK TO THE NORTH
BEHIND THE RIDGE AND CURRENT TAFS FOR MSP/RNH MAY BE HOLDING ON TO
SE WINDS TOO LONG. FOR THE END OF THE TAF...STRONG CAA LOOKS TO
SET IN...WITH MODELS SHOWING A HEALTHY AMOUNT OF MIXING
OCCURRING...BY LATE MORNING. COULD SEE SOME NW GUSTS OVER 30 KTS
FRIDAY OVER MN.
KMSP...CONFIDENCE IN CLOUD FORECAST NOT ALL THAT HIGH...SHOULD SEE
025-035 CIGS HANG AROUND THROUGH AT LEAST 20Z. AFTER THAT...HARD
TO SAY WHAT WILL HAPPEN BELOW 12K FT. MODELS SHOW PLENTY OF
MOISTURE HANGING AROUND THIS LAYER...BUT OBS TO THE WEST SHOW
CLOUDS IN THIS LAYER ONLY AS FAR WEST AS LJF/GYL...SO WENT WITH
THE IDEA OF THESE CLOUDS DIMINISHING AROUND 22Z. BASED ON GFS
TIMING...BAND OF SNOW CURRENTLY OVER ERN NODAK WOULD ARRIVE AT MSP
AROUND 09Z. SREF PROBS FOR PRECIP ACTUALLY INCREASE ACROSS ERN MN
LATE TONIGHT...SO CERTAINLY POSSIBLE THAT THE VCSH GROUP MAY NEED
AT LEAST A TEMPO -SN. FOR FRIDAY...STRONG CAA WILL BE SETTING IN.
BESIDE BRINGING GUSTY NW WINDS...IT LOOKS HIGHLY LIKELY THAT IT
WILL ALSO BRING WITH IT SOME MVFR STRATUS...ALONG WITH SOME
INSTABILITY SNOW SHOWERS THROUGH MUCH OF FRIDAY AFTERNOON.
//OUTLOOK...FRIDAY NIGHT THROUGH TUESDAY...
.FRIDAY NIGHT...MVFR CIGS BECOMING VFR.
.SATURDAY...VFR.
.SUNDAY...MVFR/IFR POSSIBLE WITH CHANCE OF RA/SN.
.MONDAY-TUESDAY...VFR.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JPC/MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1228 PM CST THU FEB 23 2012
.UPDATE...
18Z AVIATION DISCUSSION ADDED BELOW.
&&
.DISCUSSION...
IT HAS BEEN A TOUGH CALL WITH THIS SYSTEM. SHORT TERM MODEL TRENDS
HRRR/VSREF ARE SHOWING THE SNOW BAND JUST TO OUR SOUTHWEST. THE
UPPER JET/THICKNESS PATTERN STARTING OUT SOMEWHAT CONFLUENT TO
OUR SOUTHEAST AND THEN THE DEVELOPING DIFLUENT PATTERN SETS UP
OVER WESTERN IOWA AND EASTERN NEBRASKA AS THE WAVE DROPS SOUTHEAST.
BEST SURFACE PRESSURE FALLS OVER EASTERN KANSAS NOW. CLOSE CALL
WITH THE NORTH EDGE OF THE FGEN FORCING. QUITE STRONG OVER IOWA.
WILL TRIM BACK FURTHER ON THE EAST EDGE OF THE ADVSY BUT KEEP IN
ONE COUNTY FOR NOW. STILL A POSSIBILITY OF PICKING UP CLOSE TO 3
INCHES...WITH LESSER AMOUNTS TO THE EAST. NOT MUCH IN THE WAY OR
FORCING FOR THE REST OF THE AREA UNTIL THE MANITOBA WAVE DROPS SSE
ACROSS THE ARE LATER TONIGHT AND FRIDAY. KEEPING POPS IN THE
CHANCE CATEGORY FOR NOW...BUT THERE IS A CHANCE OF WIDER COVERAGE
IF DEPTH OF THE DENDRITIC ZONE INCREASES OVER EASTERN AREAS.
THE ACTIVE PATTERN WITH THE STRONG..MAINLY WESTERLY UPPER JET
CONTINUES THROUGH THE WEEKEND AND INTO NEXT WEEK WITH 2 MORE
SYSTEMS TO AFFECT THE AREA. THERE SEEMS TO BE A CONSISTENT TRACK
WITH THE SYSTEM FOR SUNDAY. A KIND OF HYBRID PACIFIC/HIGH PLANS
TYPE SYSTEM...GENERALLY TRACING EAST. STILL LOOKS TO AFFECT THE
NORTHERN CWA WITH THE HEAVIEST SNOW POTENTIAL. THERE MAY BE A RAIN
SNOW MIX FOR A TIME IN THE SOUTH.
THE NEXT SYSTEM FOR WEDNESDAY APPEARS TO HAVE A CHANCE FOR THE
GULF TO OPEN UP A BIT AND LOOKS TO BE A COLORADO/PLAINS LOW AND A
TRACK FAVORING THE SOUTHERN AND EASTERN CWA. A COUPLED UPPER JET
PATTERN ALSO DEVELOPS FOR A TIME JUST TO OUR EAST. STILL TOO EARLY
TO GO REAL HIGH WITH THE POPS THIS FAR OUT. THE TEMP PATTERN
HEADING TO A LITTLE BELOW NORMAL BUT NOT BY MUCH.
&&
.AVIATION.../18Z TAF ISSUANCE/
BIG ISSUE FOR THIS TAF PERIOD IS WHAT TO DO WITH CLOUDS.
IMPRESSIVE BAND OF SNOW OVER SE SODAK HEADING FOR CENTRAL IA AND
WILL BE MISSING ALL TAFS. SEEING PLENTY OF MID CLOUDS SPILLING
INTO THE AREA ASSOCIATED WITH THIS WAVE...BUT MORE FRUSTRATING IS
THE AMPLE MOISTURE BETWEEN 025 AND 035 THAT HAS LED TO RANDOM
CLOUD BANKS AROUND 3K FT. RH PROFILES FROM NAM/GFS/RUC SHOW THIS
MOISTURE WANING ACROSS THE AREA AFTER 00Z...SO SHOULD SEE CLOUDS
IN THIS LAYER DIMINISH AFTER SUNSET. AFTER THAT...WATCHING SWATH
OF SNOW MOVING EAST ACROSS NODAK...HAVE BEEN SOME 1/4SM VSBY SNOWS
IN NODAK...BUT HRRR REFLECTIVITY AND MODEL QPF FORECASTS ALL
SAYING THIS WILL BE DIMINISHING AS HITS MN. USED COMBO OF HRRR/RUC
THEN GFS TO TIME THIS BAND OF FORCING ACROSS THE AREA. ONLY HAVE
-SN MENTIONED AT AXN GIVEN THE UPSTREAM OBS...BUT ALL COULD SEE A
QUICK BURST OF SNOW AS IT MOVES THROUGH. WINDS HAVE BEEN A BIT
TRICKY TODAY ACROSS ERN MN/WRN WI WHERE WINDS HAVE BEEN OUT OF THE
SE OUT AHEAD OF A RIDGE AXIS. WINDS WILL QUICKLY BACK TO THE NORTH
BEHIND THE RIDGE AND CURRENT TAFS FOR MSP/RNH MAY BE HOLDING ON TO
SE WINDS TOO LONG. FOR THE END OF THE TAF...STRONG CAA LOOKS TO
SET IN...WITH MODELS SHOWING A HEALTHY AMOUNT OF MIXING
OCCURRING...BY LATE MORNING. COULD SEE SOME NW GUSTS OVER 30 KTS
FRIDAY OVER MN.
KMSP...CONFIDENCE IN CLOUD FORECAST NOT ALL THAT HIGH...SHOULD SEE
025-035 CIGS HANG AROUND THROUGH AT LEAST 20Z. AFTER THAT...HARD
TO SAY WHAT WILL HAPPEN BELOW 12K FT. MODELS SHOW PLENTY OF
MOISTURE HANGING AROUND THIS LAYER...BUT OBS TO THE WEST SHOW
CLOUDS IN THIS LAYER ONLY AS FAR WEST AS LJF/GYL...SO WENT WITH
THE IDEA OF THESE CLOUDS DIMINISHING AROUND 22Z. BASED ON GFS
TIMING...BAND OF SNOW CURRENTLY OVER ERN NODAK WOULD ARRIVE AT MSP
AROUND 09Z. SREF PROBS FOR PRECIP ACTUALLY INCREASE ACROSS ERN MN
LATE TONIGHT...SO CERTAINLY POSSIBLE THAT THE VCSH GROUP MAY NEED
AT LEAST A TEMPO -SN. FOR FRIDAY...STRONG CAA WILL BE SETTING IN.
BESIDE BRINGING GUSTY NW WINDS...IT LOOKS HIGHLY LIKELY THAT IT
WILL ALSO BRING WITH IT SOME MVFR STRATUS...ALONG WITH SOME
INSTABILITY SNOW SHOWERS THROUGH MUCH OF FRIDAY AFTERNOON.
//OUTLOOK...FRIDAY NIGHT THROUGH TUESDAY...
.FRIDAY NIGHT...MVFR CIGS BECOMING VFR.
.SATURDAY...VFR.
.SUNDAY...MVFR/IFR POSSIBLE WITH CHANCE OF RA/SN.
.MONDAY-TUESDAY...VFR.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JPR/MPG
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
345 PM CST THU FEB 23 2012
...UPDATED PUBLIC AND AVIATION...
.DISCUSSION...
As expected, temperatures soared well into the 60s within the warm
sector early this afternoon, even more so than anticipated with the
earlier update. 20Z surface analysis continued to show a complex
frontal structure with two surface lows extending from near Omaha to
near Moberly, with most of the CWA now located in the post-frontal
airmass. Gusty northwest winds will continue to surge east across
the remainder of the CWA through 00Z, accompanied by extensive
cloud cover and steadily falling temperatures.
Two primary concerns as we head into this evening.
1.) Wind. The RUC13 has done an outstanding job with the
placement/intensity of strong winds across Nebraska/Kansas today,
which justifies my earlier concern with respect to the ongoing wind
advisory. Increasing friction (terrain, trees, etc...) over the
eastern Plains coupled with the loss of daytime heating will both
act against a simple advection of upstream conditions into the
western CWA this evening. Already pushed back the start time of the
wind advisory until 6PM, which looks reasonable given the
juxtaposition of the strongest winds immediately south/southeast of
the digging mid-level trough axis. However, considering both minimal
impacts (after the evening commute) and the aforementioned
meteorology, am concerned that the advisory may no longer be
warranted. Still, we may see both sustained speeds and gusts locally
meet criteria (30/45), and will leave the headline active through
this evening. Still will be a windy/blustery evening regardless,
with 60s giving way to 30s by midnight.
2.) Precipitation. Satellite presentation with the mid level trough
over eastern Nebraska continues to improve this afternoon, and
additional deepening is expected as the wave digs southeast along
the Nebraska/Missouri border overnight. A compact area of vigorous
ascent and diabatic cooling immediately behind the trough, acting as
a small scale deformation band, may affect the far northern tier
counties between 9-10PM and shifting east through the overnight
hours. Given favorable dendritic snow growth profiles, it is
possible that a period of moderate to heavy snow could brush the
Iowa border counties, resulting in minor accumulations. Do expect
Iowa/Illinois to receive the brunt of this evening and for now have
painted an inch across the northern counties, but would not be
surprised if a short-fused advisory became necessary overnight.
Evening hazardous weather outlook will be amended as necessary to
reflect this impact. If concerns #1 and
#2 overlap at some point tonight, we could have an additional issue
with blowing snow/visibilities impacting travel north of highway 36.
Otherwise, gusty winds and strong cold advection will continue into
tomorrow. Previous forecast already reflected undercutting guidance
on temperatures and made no change there. Cyclonic flow will
maintain cloud cover, especially over the northeast half of the CWA
and would not be surprised to see a few sprinkles/flurries from time
to time either.
Return flow comes back in a hurry Saturday afternoon, with winds
increasing over the western CWA. Should see another 10-15 degree
gradient from northeast Missouri to eastern Kansas.
Bookbinder
Medium Range (Sunday through Thursday)...
The focus for the weather over the latter half of the forecast is on
two features; the first a shortwave due to zip east through the
Northern Plains into the Great Lakes Saturday into Sunday; the
second shortwave of note will then follow on quickly through the
Central Plains Monday night through Wednesday.
Leading shortwave, due to pass through the Plains Saturday/Sunday,
will be starved for moisture. A surface high slowly shifting east
along the Gulf Coast will effectively shut off any return moisture
from the Gulf over the weekend. Couple that observation with the
notable speed with which this shortwave jets east through the
Northern Plains, and precipitation of any form for the weekend looks
like a non-issue. Have kept the forecast dry, and boosted afternoon
highs on the expectation of breezy southwest winds. This should put
temperatures for the last day of the weekend into the 50s to low
60s.
After the passage of the weekend leading shortwave, a second wave is
due to pass through the Central Plains during the beginning of the
work week. Sunday`s shortwave, while dry, will have the ultimate
effect of shoving the baroclinic zone a little father south as weak
high pressure oozes into the Northern Plains, pushing afternoon
highs back down towards normal. This results in the second wave
kicking out across the plains form the Four Corners region, zipping
through the Lower Missouri River Valley. At this point the surface
high along the Gulf Coast will have advected east under the
influence of the progressive flow across the nation, leaving the
Gulf open to allow moisture return which the second shortwave will
be able to tap.
This second system has the potential to be significant weather
maker. While models are in decent enough broad agreement on the
general trend of the shortwave to warrant including likely POPs for
part of Tuesday and Tuesday night, preference on the specifics of
shortwave timing are hedged towards the faster ECMWF and GEM
solutions. GFS is the slowest in ejecting the wave, which seems a
bit off given the progressive flow. Anyhow, have limited snow POPs
to the Iowa border region where the coolest air will be, but
otherwise have a mix of rain and rain/snow across the various
forecast periods from Monday night through Wednesday. Did add in
isolated thunder for areas along and south of I-70 owing to some
limited instability present during the afternoon Tuesday.
Cutter
&&
.AVIATION...
winds continue to increase across the terminals with gusts now in
the 25 to 30 knot range, along with widespread low-VFR cloud cover.
Ceilings are now expected to lower into the MVFR category this
evening.
Wind gusts of 30 to locally 40 knots, associated with a secondary
frontal surge and cyclogenesis over northeast Nebraska, will
continue to push southeast this afternoon. RUC13 model has handled
this well, and has the core of winds approaching the terminals just
after 00Z. The speeds measured across the open Plains will diminish
somewhat due to friction and loss of daytime heating, but expect a
very windy evening across the terminals from a 290/300 direction
with a few gusts to near 40 knots possible (especially MCI).
This surge should exit the area after 06Z, although gusty northwest
winds will continue through the remainder of the TAF period. There
is some concern that a brief band of light snow (and MVFR to IFR
conditions) may affect KSTJ/KMCI after 05Z and will continue to
analyze trends to the north for the 00Z TAF cycle.
Bookbinder
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...WIND ADVISORY FROM 6PM THIS EVENING TO MIDNIGHT CST TONIGHT FOR
MOZ001>004-011>013-020>022-028>030-037-038-043>045-053-054.
KS...WIND ADVISORY FROM 6PM THIS EVENING TO MIDNIGHT CST TONIGHT FOR
KSZ025-057-060-102>105.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
339 PM CST THU FEB 23 2012
.DISCUSSION...
As expected, temperatures soared well into the 60s within the warm
sector early this afternoon, even more so than anticipated with the
earlier update. 20Z surface analysis continued to show a complex
frontal structure with two surface lows extending from near Omaha to
near Moberly, with most of the CWA now located in the post-frontal
airmass. Gusty northwest winds will continue to surge east across
the remainder of the CWA through 00Z, accompanied by extensive
cloud cover and steadily falling temperatures.
Two primary concerns as we head into this evening.
1.) Wind. The RUC13 has done an outstanding job with the
placement/intensity of strong winds across Nebraska/Kansas today,
which justifies my earlier concern with respect to the ongoing wind
advisory. Increasing friction (terrain, trees, etc...) over the
eastern Plains coupled with the loss of daytime heating will both
act against a simple advection of upstream conditions into the
western CWA this evening. Already pushed back the start time of the
wind advisory until 6PM, which looks reasonable given the
juxtaposition of the strongest winds immediately south/southeast of
the digging mid-level trough axis. However, considering both minimal
impacts (after the evening commute) and the aforementioned
meteorology, am concerned that the advisory may no longer be
warranted. Still, we may see both sustained speeds and gusts locally
meet criteria (30/45), and will leave the headline active through
this evening. Still will be a windy/blustery evening regardless,
with 60s giving way to 30s by midnight.
2.) Precipitation. Satellite presentation with the mid level trough
over eastern Nebraska continues to improve this afternoon, and
additional deepening is expected as the wave digs southeast along
the Nebraska/Missouri border overnight. A compact area of vigorous
ascent and diabatic cooling immediately behind the trough, acting as
a small scale deformation band, may affect the far northern tier
counties after 11PM into the predawn hours. Given the favorable
dendritic snow growth, it is possible that a period of moderate to
heavy snow could brush the Iowa border counties, resulting in minor
accumulations. Do expect Iowa/Illinois to receive the brunt of this
evening and for now have painted an inch across the northern
counties, but would not be surprised if a short-fused advisory
became necessary overnight. Evening hazardous weather outlook will
be amended as necessary to reflect this impact. If concerns #1 and
#2 overlap at some point tonight, we could have an additional issue
with blowing snow/visibilities impacting travel north of highway 36.
Otherwise, gusty winds and strong cold advection will continue into
tomorrow. Previous forecast already reflected undercutting guidance
on temperatures and made no change there. Cyclonic flow will
maintain cloud cover, especially over the northeast half of the CWA
and would not be surprised to see a few sprinkles/flurries from time
to time either.
Return flow comes back in a hurry Saturday afternoon, with winds
increasing over the western CWA. Should see another 10-15 degree
gradient from northeast Missouri to eastern Kansas.
Bookbinder
Medium Range (Sunday through Thursday)...
The focus for the weather over the latter half of the forecast is on
two features; the first a shortwave due to zip east through the
Northern Plains into the Great Lakes Saturday into Sunday; the
second shortwave of note will then follow on quickly through the
Central Plains Monday night through Wednesday.
Leading shortwave, due to pass through the Plains Saturday/Sunday,
will be starved for moisture. A surface high slowly shifting east
along the Gulf Coast will effectively shut off any return moisture
from the Gulf over the weekend. Couple that observation with the
notable speed with which this shortwave jets east through the
Northern Plains, and precipitation of any form for the weekend looks
like a non-issue. Have kept the forecast dry, and boosted afternoon
highs on the expectation of breezy southwest winds. This should put
temperatures for the last day of the weekend into the 50s to low
60s.
After the passage of the weekend leading shortwave, a second wave is
due to pass through the Central Plains during the beginning of the
work week. Sunday`s shortwave, while dry, will have the ultimate
effect of shoving the baroclinic zone a little father south as weak
high pressure oozes into the Northern Plains, pushing afternoon
highs back down towards normal. This results in the second wave
kicking out across the plains form the Four Corners region, zipping
through the Lower Missouri River Valley. At this point the surface
high along the Gulf Coast will have advected east under the
influence of the progressive flow across the nation, leaving the
Gulf open to allow moisture return which the second shortwave will
be able to tap.
This second system has the potential to be significant weather
maker. While models are in decent enough broad agreement on the
general trend of the shortwave to warrant including likely POPs for
part of Tuesday and Tuesday night, preference on the specifics of
shortwave timing are hedged towards the faster ECMWF and GEM
solutions. GFS is the slowest in ejecting the wave, which seems a
bit off given the progressive flow. Anyhow, have limited snow POPs
to the Iowa border region where the coolest air will be, but
otherwise have a mix of rain and rain/snow across the various
forecast periods from Monday night through Wednesday. Did add in
isolated thunder for areas along and south of I-70 owing to some
limited instability present during the afternoon Tuesday.
Cutter
&&
.AVIATION...
Initial cold front surge moving across the terminals now, so expect
northwest winds to attain a gusty character of 20 to 25 knots within
the next hour where they haven`t already. Otherwise, VFR conditions
and sct-bkn mid clouds will be the rule for the rest of today.
Wind gusts of 40 to locally 50 knots, associated with a secondary
frontal surge and cyclogenesis over northeast Nebraska, will
continue to push southeast this afternoon. High resolution models
like the HRRR/RUC13 both handle this well, and have the core of
winds approaching the terminals just after 00Z. The speeds measured
across the open Plains will diminish somewhat due to friction and
loss of daytime heating, but expect a very windy evening across the
terminals from a 290/300 direction with a few gusts to near 40 knots
possible (especially MCI).
This surge should exit the area after 06Z, although gusty northwest
winds will continue through the remainder of the TAF period.
Upstream broken MVFR ceilings look to be diurnally driven so for now
have not included this in the TAFs.
Bookbinder
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...WIND ADVISORY FROM 6PM THIS EVENING TO MIDNIGHT CST TONIGHT FOR
MOZ001>004-011>013-020>022-028>030-037-038-043>045-053-054.
KS...WIND ADVISORY FROM 6PM THIS EVENING TO MIDNIGHT CST TONIGHT FOR
KSZ025-057-060-102>105.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION
NWS GLASGOW MT
921 AM MST THU FEB 23 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SATURDAY...
GOING FORECAST LOOKS PRETTY GOOD. SCATTERED SNOW SHOWERS ALREADY
MOVING INTO THE CWA THIS MORNING FROM CANADA. HRRR MODELS
ADVERTISING A BAND OF HEAVIER PRECIP TO SET UP OVER THE SW ZONES
LATER TODAY ALONG AN INSTABILITY AXIS. NAM AND GFS NOT QUITE ON
BOARD WITH THIS...BUT WILL KEEP AN EYE ON IT. JAMBA
PREVIOUS DISCUSSION...
NORTHWEST FLOW ALOFT WILL PREVAIL TODAY AND FRIDAY. TIGHT
SURFACE GRADIENT BETWEEN DEPARTING AND DEEPENING SURFACE LOW TO
THE EAST AND HIGH PRESSURE SYSTEM TO THE WEST WILL BRING GUSTY
NORTHWEST WINDS. UNSTABLE AIRMASS...MOIST ATMOSPHERE AND WEAK
SHORTWAVE WILL AID IN DEVELOPING SNOW SHOWERS THAT WILL BE
SCATTERED ACROSS THE AREA ESPECIALLY THIS AFTERNOON.
THE SNOW SHOWERS AND WINDS WILL DIMINISH THIS EVENING AS HIGH
PRESSURE SYSTEM MOVES INTO THE AREA. MEANWHILE...A WEAK SHORTWAVE
MOVING THROUGH CENTRAL MONTANA TONIGHT MAY PRODUCE A SNOW SHOWER
IN THE SOUTHWEST ZONES. WILL MENTION A SLIGHT CHANCE FOR NOW.
THE HIGH PRESSURE SYSTEM WILL BRING MAINLY QUIET WEATHER ON FRIDAY
ALTHOUGH A FEW AREAS MAINLY IN THE SOUTH COULD HAVE A LINGERING
SNOW SHOWERS.
UPPER RIDGE PASSES THROUGH THE AREA FRIDAY NIGHT WITH THE NEXT
UPPER TROUGH QUICKLY BEHIND IT ON SATURDAY. A BAND OF OVERRUNNING
SNOW MOVES INTO SOUTHWEST SASKATCHEWAN LATE FRIDAY NIGHT AND
OVERSPREADS SOUTHERN SASKATCHEWAN AND FAR NORTHERN MONTANA DURING
THE DAY SATURDAY. IT WILL BE A COMPLEX SYSTEM WITH ONE LOW
WEAKENING OVER ALBERTA OR SW SASKATCHEWAN ON SATURDAY WHILE
ANOTHER LOW ALONG AN OCCLUDED FRONT DEVELOPS IN WYOMING. THE
SOUTHEAST ZONES APPEAR TO BE IN A DRY SLOT FOR MOST OF SATURDAY.
WILL REDUCE THE CHANCES OF SNOW THERE. AREAS NORTH OF US 2 WILL
LIKELY BE IN THE MAIN SNOW BAND ALTHOUGH MODELS ARE NOT IN PERFECT
AGREEMENT AT THIS POINT. WILL GO CATEGORICAL POPS ALONG THE
CANADIAN BORDER AND GRADUALLY LOWER POPS TO THE SOUTH. FORRESTER
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
A STRONG NORTH PACIFIC STORM SYSTEM WILL SLAM INTO THE CANADIAN
WEST COAST TONIGHT AND MOVE OVER THE DIVIDE AND INTO EASTERN
MONTANA ON SATURDAY. THIS STORM WILL BE IN PROGRESS SATURDAY
EVENING TO BEGIN THE EXTENDED PERIOD. AT 00Z SUNDAY...MODELS PLACE
THE BASE OF THE DEEP UPPER TROUGH OVER THE GREAT BASIN REGION AND
THE LEE SURFACE TROUGH CENTERED OVER NE WYOMING. THERE IS A
SUBSTANTIAL AMOUNT OF PACIFIC MOISTURE BROUGHT BY THIS STORM.
NORTHEAST MONTANA WILL BE ON THE ARCTIC SIDE OF THE COLD FRONT
UNDER THE INVERTED TROUGH. THE FOCUS OF THE WINTER STORM WILL BE
OVER SOUTHERN SASKATCHEWAN AND NEMONT THROUGH SUNDAY MORNING.
THEREFORE THE BULK OF THE SNOW SHOULD BE NORTH OF THE MISSOURI
RIVER WITH A STORM TOTAL RANGING FROM 1 TO 4 INCHES OF SNOW...
BASED ON THE QPF.
BY SUNDAY AFTERNOON THE BASE OF THE UPPER TROUGH WILL HAVE
TRAVELED INTO THE AREAS OF THE DAKOTAS OR MINNESOTA. THERE WILL
STILL BE LINGERING BACK DOOR SNOW SHOWERS LOCALLY WHILE
TEMPERATURES BEGIN TO DROP. A POLAR VORTEX NEAR HUDSON BAY WILL
NUDGE 850MB TEMPERATURES BY 00Z MONDAY TO BE AROUND -16C. EXPECT
SUNDAY NIGHT LOWS TO FALL BELOW 0F AND MONDAY HIGHS TO NOT WARM UP
MUCH ABOVE SUNDAY.
ANOTHER DEEP UPPER LEVEL TROUGH SWINGS INTO THE WESTERN STATES ON
MONDAY. HOWEVER THE MAIN TROUGH ENERGY WILL SWING SOUTH OF
NORTHEAST MONTANA. HOWEVER WITH GENERAL TROUGHINESS... SOME
INSTABILITY INITIATING SHOWERS IS POSSIBLE THROUGH MONDAY NIGHT.
BEHIND THE TROUGH AN UPPER LEVEL RIDGE BEGIN TO BUILD IN OVER THE
PACNW. THIS SHOULD KEEP CONDITIONS DRY THROUGH WEDNESDAY.
TEMPERATURES WILL BEGIN TO TREND BACK TO AROUND NORMAL. THEN BOTH
THE EC AND GFS BRING IN YET ANOTHER UPPER TROUGH INTO THE PACNW ON
WEDNESDAY. THIS WAVE WILL BRING A CHANCE OF SHOWERS THROUGH DAY 8.
SCT
&&
.AVIATION...
SCATTERED FLURRIES AND LIGHT SNOW SHOWERS THIS MORNING MAY BRIEFLY
AFFECT KGGW AND KOLF WITH MVFR CONDITIONS THIS MORNING...THEN MOVE
MORE OVER KSDY AND KGDV LATER THIS AFTERNOON WHERE FLIGHT
CONDITIONS MAY DROP TO NEAR IFR LEVELS DURING THE BRIEF PASSES OF
QUICK HEAVIER SNOW SHOWERS. EXPECT VFR CONDITIONS TO RETURN TO ALL
TAF SITES LATER THIS EVENING. ALSO...AFTERNOON WINDS FROM THE
NORTHWEST WILL INCREASE INTO THE 25G35KT RANGE...RAISING CROSSWIND
CONCERNS FOR RUNWAYS PERPENDICULAR TO THAT. BMICKELSON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
1133 AM CST THU FEB 23 2012
.DISCUSSION...NARROW BAND OF MODERATE SNOWFALL HAS SET UP FROM
GRAND FORKS TO COOPERSTOWN...AND SOUTHWEST INTO SOUTHCENTRAL NORTH
DAKOTA. THIS SNOWFALL IS ASSOCIATED WITH LOW-MID LEVEL
FRONTOGENESIS ALONG WINDSHIFT (COLD FRONT). HRRR APPEARS TO HAVE A
DECENT HANDLE ON THIS SNOWBAND...PROPAGATING IT TO THE SOUTHEAST
AFFECTING SOUTHEAST NORTH DAKOTA AND ADJACENT AREAS IN MINNESOTA
THIS AFTERNOON. DURATION WILL BE BRIEF...BUT HIGH SNOWRATES SHOULD
LEAD TO 1-2 INCHES OF NEW SNOW. UPDATED FORECAST TO INCREASE POPS
AND SNOW AMOUNTS ACROSS THIS AREA. WILL MONITOR TRENDS AND UPDATE
AGAIN IF NEEDED.
&&
.AVIATION...SCATTERED SNOW SHOWERS POSSIBLE. LIGHT WINDS THIS
MORNING WILL SHIFT TO THE WEST AND NORTHWEST THIS AFTN OVER ERN ND
AND OVER NW MN THIS EVE AND BE A BIT BREEZY AT TIMES INTO FRIDAY
IN THE 15 TO 20 KT RANGE. ANY REMAINING VFR CIGS WILL BECOME MVFR
BY THIS AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 953 AM CST THU FEB 23 2012/
DISCUSSION...CONCERN TODAY WILL BE SNOW CHANCES AND TEMPERATURES.
SHORTWAVE TO THE NORTH WILL DROP SOUTH TO NEAR WINNIPEG BY
00Z. THERE IS A WEAK 700MB BAROCLINIC ZONE THAT WILL TRANSITION
EASTWARD THROUGH THE FA TODAY AS A RESULT. TIMED 50%
POPS/SCATTERED SNOW SHOWERS FROM WEST TO EAST WITH THIS
MID-LEVEL FRONTOGENESIS. SNOWFALL ACCUMULATIONS SHOULD REMAIN
BELOW AN INCH. CURRENT RADAR ANALYSIS CONFIRMS THIS THINKING.
THE 1/4 FOG ACROSS THE NORTHEAST FA WILL QUICKLY IMPROVE AS CLOUDS
MOVE IN. NOT SURE HOW TEMPERATURES ARE GOING TO RESPOND
TODAY...BUT GIVEN AIRMASS TEMPS UPPER 20S TO NEAR 30F SEEMS
REASONABLE.
PREV DISCUSSION... /ISSUED 351 AM CST THU FEB 23 2012/
SHORT TERM...
A WIDE VARIETY OF CONDITIONS OVER THE FCST AREA EARLY THIS
MORNING. THIS WILL MAKE EXACT TEMP FCSTS THROUGH THIS MORNING
QUITE DIFFICULT. LARGE CLEAR HOLE GRAND FORKS TO THIEF RIVER FALLS
DOWN TO FARGO...FERGUS FALLS AND PARK RAPIDS. IN THIS CLEAR HOLE
TEMPS HAVE FALLEN INTO THE SINGLE DIGITS IN MANY AREAS AND ALSO
PATCHES OF DENSE FOG HAS FORMED. CLOUDS MOVING IN FROM THE
NORTHWEST INTO NORTHEAST ND SHOULD CONTINUE TO ADVANCE SOUTHEAST
OVER THE NEXT FEW HOURS AND AS IT DOES SHOULD CAUSE TEMPS TO RISE
AND EVENTUALLY THE PATCHES OF FOG TO SHRINK. THAT SAID WILL
MENTION AREAS OF FOG THRU 15Z FOR GFK-BJI-PKD-FAR AREA AS
CONDITIONS WILL REMAIN HIGHLY VARIABLE.
AS FOR PRECIP...SYSTEM DROPPING THRU THE WRN DAKOTAS ATTM WITH SFC
LOW MOVING INTO NORTHWEST-NORTH CENTRAL SOUTH DAKOTA AT 09Z. MAIN
SNOW BAND REMAINING MISSOURI RIVER AND WESTWARD...AND FEEL ANY
THREAT FOR LIGHT SNOW WITH THIS SYSTEM IN OUR WRN FCST AREA
REMAINS QUITE LOW. WATER VAPOR SHOWS A SMALL VORT MAX MOVING THRU
SRN MANITOBA AND RADARS SHOW A SMALL AREA OF LIGHT SNOW DROPPING
SOUTHEAST FROM THE MORDEN AREA INTO HALLOCK-CAVALIER. THIS AREA OF
LIGHT SNOW IS PROGGED TO MOVE EAST-SOUTHEAST TOWARD LAKE OF THE
WOODS REGION THIS MORNING. AS SOUTH DAKOTA SYSTEM MOVES FAR ENOUGH
SOUTH....WINDS WILL SHIFT TO THE WEST-NORTHWEST OVER ERN ND AS
COLDER AIR AT 850 MB ADVECTS IN. AS IT DOES...UPSTREAM OBS SHOWS
PLENTY OF CLOUDS AND SPOTTY -SN. WILL MAINTAIN SOME LOW POPS FOR
SPOTTY -SN THIS AFTN AND MAINTAIN THIS TONIGHT.
FRIDAY WILL SEE UPPER LOW OVER WCNTRL MANITOBA DROP INTO NRN MN
AND WILL MAINTAIN SOME -SN WITH THIS...WITH MINIMAL AMTS. TEMPS
EARLY TODAY WILL BE HIGHLY VARIABLE AND DEPENDENT ON CLOUD
COVER....BUT BY MID AFTN MOST SITES SHOULD SEE HIGHS IN THE UPPER
20S TO LOWER 30S. COOLER FOR TONIGHT INTO FRIDAY AND A BIT BREEZY
AS WELL WITH NORTHWEST WINDS.
BRIEF CLEARING WILL MOVE IN FRIDAY NIGHT BEFORE MID AND HIGH LEVEL
CLOUDS IN ADVANCE OF NEXT SYSTEM MOVE IN ON SATURDAY. WILL START
TO BRING IN LIKELY POPS SAT NIGHT INTO DVL REGION WITH CHC POPS
ELSEWHERE...MOSTLY AFTER MIDNIGHT.
LONG TERM (SUN-WED)...
ALL MODELS CONTINUED A NORTHWARD DRIFT TO THE OVERALL SYSTEM ON
THE 00Z SUITE. ALSO TREND WAS A BIT WEAKER WITH A BIT LESS
QPF/SNOWFALL AMTS. SYSTEM INITIALLY MORE MID AND UPPER LEVEL
FOCUSED AS 500 MB LOW MOVES OUT OF SRN SASK INTO NRN ND SUNDAY
MORNING. THUS INITIALLY SNOW WILL BE MOSTLY FROM SRN SASK INTO NRN
ND. DURING THE DAY ON SUNDAY...SFC LOW WILL BETTER ORGANIZE IN ERN
SD AND MOVE INTO CNTRL MN WITH 500-700 MB LOWS STRENGTHENING
CLOSER TO SFC LOW. THUS EXPECT A RE-DEVELOPMENT OR SHIFTING TO
SNOW AREA TO MORE OVER WCNTRL-NW-CNTRL MN BY LATE SUNDAY. WINDS
STILL DONT APPEAR TERRIBLE..WITH 850 MB WINDS PROGGED NR 25 KTS.
QUESTIONS REMAIN IN HOW DOES THE MINNESOTA SFC AND MID-UPPER LEVEL
FEATURES ORGANIZE ON SUNDAY. INITIAL BAND OF -SN MORE MID LEVEL
FRONTOGENESIS FOCUSED WITH FOCUS OVER THE NRN VALLEY LATE SAT
NIGHT-EARLY SUNDAY MORNING. PWATS NOT ALL THAT HIGH INCREASING TO
0.33 OR SO...SO MAY NOT BE A BLOCKBUSTER SNOWFALL STORM BUT STORM
STILL WILL BE A HAZARD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
TG
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
121 PM EST THU FEB 23 2012
.SYNOPSIS...
LOW PRESSURE WILL DEVELOP OVER THE MIDDLE MISSISSIPPI VALLEY
TODAY. THE LOW WILL DEEPEN TONIGHT AS IT MOVES NORTHEAST TOWARD THE
EASTERN GREAT LAKES. A COLD FRONT WILL SWEEP ACROSS THE AREA IN
THE WAKE OF THE LOW...BRINGING MUCH COLDER AIR TO THE OHIO VALLEY
ON FRIDAY. COLD AIR ALONG WITH SNOW SHOWERS CAN BE EXPECTED FOR
THE FIRST PART OF THE WEEKEND. HIGH PRESSURE WILL RETURN TO THE
OHIO VALLEY ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST THINKING EARLY THIS AFTERNOON IS A CONTINUED EXPECTATION
FOR STORMS TO INITIATE IN SRN INDIANA BY 4 PM...AND MOVE RAPIDLY
NORTHEAST ALONG/JUST NORTH OF WARM FRONT. 1630Z SPC SWODY1
SUCCINCTLY SUMMED UP THE CONCERNS...NAMELY THE WARM SECTOR/S
MOISTURE QUALITY AND ABILITY FOR STORMS TO TAP THE MARGINAL
INSTBY. WINDOW OF 50S DEWPOINTS VERY NARROW AT 17Z OVER WRN
KY/TN...AND WHERE STORMS DEVELOP IN RELATION TO THIS WILL
DETERMINE OVERALL SEVERITY. RIGHT NOW AS IT STANDS...RUC FORECAST
SOUNDINGS EARLY THIS EVENING FOR CVG/MDN ARE ISOTHERMAL TO VERY
SLIGHTLY INVERTED FROM THE SFC TO 900MB - WHICH DOESN/T RULE OUT TORNADO
THREAT COMPLETELY...BUT PUTS SOME QUESTION. NOT SURPRISED TO SEE
SPC PULL HIGHER TOR PROBS BACK A LITTLE. GIVEN THE AMPLE LOW
LEVEL SHEAR...THESE THERMODYNAMIC PROFILES SEEMS TO FIT MORE WITH
TYPICAL OHIO VALLEY COOL- SEASON QLCS SHOULD STORMS BECOME LINEAR
AND/OR HAVE BROKEN-S FORMATIONS IN THE LINE SEGMENTS. NEW 23.12Z
SPC NMM- WRF IS AGGRESSIVE WITH A CONVECTIVE CLUSTER RUNNING ALONG
THE OHIO RIVER AND RECENT HRRR RUNS A LITTLE NORTH OF THIS.
CERTAINLY THE CLOSER ANY STORMS/STORM CLUSTERS ARE TO THE WARM
FRONT/HIGH THETA-E SOURCE...THE MORE CONCERN. WILL VERY MUCH NEED
TO BE MONITORED ON THE STORM SCALE ON HOW STORMS INTERACT/EVOLVE
WITH THE SLOWLY NORTHWARD MOVING WARM SECTOR. STILL THE MOST
CONCERNED FOR AREAS WEST OF CVG THROUGH AND THEN EAST ALONG THE
OHIO RIVER. MUCH FURTHER NORTH AND SOUNDINGS SUPPORT MORE ELEVATED
THAN SFC BASED CONVECTION.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
SFC LOW AND ASSOCIATE S/WV WILL PIVOT NE ACRS NEW ENGLAND/SAINT
LAWRENCE RIVER VALLEY ON FRIDAY WHILE AN UPPER LEVEL TROF AND
EMBEDDED DISTURBANCES WITHIN THE FLOW BEGIN TO AFFECT THE REGION.
COLDER AIR WILL CONTINUE TO FILTER IN ON FRIDAY ALONG WITH
SCATTERED RAIN SHOWERS AND SNOW SHOWERS. PCPN SHOULD CHANGE TO ALL
SNOW BY FRIDAY NIGHT AS TEMPERATURES CONTINUE TO FALL. BY
SATURDAY...COLD UPR LVL TROF WILL BEGIN TO PIVOT NE. 850 MB COLD
POOL WILL BE AT ITS MAXIMUM RESULTING IN BELOW NORMAL TEMPERATURES
AND LINGERING SNOW SHOWERS. UPR LVL TROF WILL PUSH OFF THE
ATLANTIC SEABOARD SATURDAY NIGHT...ALLOWING SFC HIGH PRESSURE TO
BUILD INTO THE OHIO VALLEY. ON SUNDAY...SFC HIGH WILL MOVE EAST.
ALONG WITH MOSTLY SUNNY SKIES...TEMPERATURES WILL REBOUND IN THE
RETURN FLOW PATTERN ON THE BACK SIDE OF THE DEPARTING HIGH.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
A STRONG LOW WILL MOVE THROUGH THE UPPER MIDWEST TO THE NORTHERN
GREAT LAKES REGION SUNDAY AND MONDAY...TRAILING A COLD FRONT
THROUGH THE OHIO VALLEY. MODELS DIFFER ON THE TRACK AND STRENGTH
OF THE LOW AND ITS ASSOCIATED COLD FRONT. THIS DIFFERENCE WILL
RESULT IN A HIGHER UNCERTAINTY IN THE CHANCES OF RAIN AHEAD OF THE
FRONT ON MONDAY...AND WITH ITS PASSAGE MONDAY NIGHT.
HIGH PRESSURE AND A DRY PATTERN IS IN STORE FOR TUESDAY IN THE OHIO
VALLEY. MODELS QUICKLY DIVERGE IN THEIR OVERALL REPRESENTATION OF
THE PATTERNS BEGINNING TUESDAY. 0Z MODEL BLEND IS USED BY HPC
THROUGH TUESDAY AND THEN A BLEND WITH THE 12Z ECMWF IS USED FOR
MIDWEEK. WILL USE THE LATEST EUROPEAN FOR THE TUES NIGHT/WED
FORECAST WHEN IT COMES IN.
HIGH TEMPERATURES WILL BE AROUND NORMAL FOR MUCH OF THE PERIOD.
LOWS WILL RISE BACK TO ABOVE NORMAL LEVELS WHICH HAVE BEEN COMMON
THIS WINTER SEASON.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
CURRENT BAND OF LIGHT RAIN ON RADAR IS NOT REDUCING CIGS/VSBYS AT
ALL TO CRITICAL LEVELS...SO THIS IS NOT OF CONCERN THROUGH 22Z.
THEREAFTER...SHOWERS/STORMS EXPECTED TO DEVELOP IN SOUTHERN INDIANA AND
SPREAD THROUGH MANY OF THE TAF SITES. INSTABILITY CONTINUES TO BE
EXTREMELY LIMITED THUS HAVE GONE CONSERVATIVE ON AMOUNT OF THUNDER
USED IN THE TERMINALS. CURRENTLY HAVE LEFT IT OUT BUT SEE THE BEST
POTENTIAL AT CVG/LUK/DAY BEFORE INSTABILITY WANES FURTHER TO THE
NORTH/EAST FOR THE CMH/LCK. VSBYS AND CIGS THOUGH SHOULD AT LEAST
BE MVFR DURING AND WILL LIKELY DIP BELOW TO IFR IN THE HEAVIEST
DOWNPOURS. PREFER TO SEE CONVECTIVE INITIATION FIRST BEFORE
INSERTING THIS IN THE TERMINALS AS THERE IS SOME QUESTION ON WHERE
THE MORE FOCUSED BATCH OF IFR VSBYS WILL BE IN FALLING RAIN AND/OR
THUNDER.
VERY TOUGH WIND FORECAST WITH SFC LOW TO PASS DIRECTLY OVERHEAD
SOME OF THE TAF SITES. HAVE PLAYED A SOLUTION WHICH TAKES SFC LOW
FROM DAY TO CMH SO TRIED TO INDICATE A PERIOD OF LGT/VARIABLE FLOW
AS THE SFC LOW GOES BY THIS EVENING. AT CVG/LUK...WAS QUICK TO
BRING IN THE STRONGER SWLY FLOW IMMEDIATELY AS THE LOW PASSES. ALL
SITES HAVE POTENTIAL FOR VERY STRONG GUSTS > 35 KTS LATER TONIGHT
INTO MUCH OF FRIDAY MORNING. IN THE COLD ADVECTION...EXPECT
WIDESPREAD BKN MVFR CIGS WITH THE STEEP LAPSE RATES...STRONG
WINDS...AND THE POTENTIAL FOR A FEW SHOWERS.
OUTLOOK...GUSTY WESTERLY WINDS WILL BE POSSIBLE ON FRIDAY. MVFR
CEILINGS ARE POSSIBLE FRIDAY NIGHT INTO SATURDAY MORNING.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...BINAU
SHORT TERM...HICKMAN
LONG TERM...FRANKS
AVIATION...BINAU
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1133 AM MST THU FEB 23 2012
.UPDATE...VERY COLD TEMPERATURES IN THE UPPER TROUGH WILL BE
OVERHEAD TODAY...AND RUC IS FORECASTING VERY STEEP LAPSE RATES WITH
INCREASING LLVL INSTABILITY THROUGH THE DAY. VISIBLE SATELLITE
LOOP SHOWS A BROAD AREA OF MORE CONVECTIVE TYPE CLOUDS WHICH FIT WELL
WITH THE RUC FORECAST OF INSTABILITY. SO BUMPED UP SNOW CHANCES
ACROSS THE FORECAST AREA FOR THIS AFTERNOON...ESPECIALLY AREAS IN
AND NEAR THE LARAMIE RANGE WHICH WERE ON THE LOW SIDE TO BEGIN THE
DAY. COULD SEE LOCALLY HIGHER SNOWFALL RATES AT TIMES WITH THE
SHOWERS...BUT QUICK DURATION WILL ONLY ALLOW MINIMAL ACCUMULATIONS
TO OCCUR. EXCEPTION WILL BE IN THE MOUNTAINS ABOVE 9000 FEET WHICH
SHOULD SEE MORE NUMEROUS SHOWERS PASS OVERHEAD DO TO ADDITIONAL
TERRAIN FORCING...SO AN ADDITION 1 TO 4 INCHES OF SNOW IS POSSIBLE
THROUGH THIS EVENING HERE.
WIND ADVISORY FOR THE NEBRASKA PANHANDLE LOOKS TO BE IN GOOD SHAPE
AS MESOWEST PLOT SHOWS A NUMBER OF SITES ARE SUSTAINED NEAR 30
MPH WITH GUSTS AROUND 45 MPH. RJM
&&
.PREV DISCUSSION... /ISSUED 1027 AM MST THU FEB 23 2012/
AVIATION...18Z TAF ISSUANCE...
MAINLY VFR OVER THE TERMINALS THROUGH FRIDAY UNDER NW FLOW ALOFT.
SOME HIGHER MTN OBSCURATIONS AND ASSOCIATED SNOW SHOWERS THOUGH AS
MOISTURE RIDES UP THE NW FACING SLOPES. SCTD BRIEF MVFR CIGS/VSBYS
OVER THE PLAINS THIS AFTERNOON IN SNOW SHOWERS AS UPPER DISTURBANCE
MOVES ACROSS THE REGION AND INTERACTS WITH SOME WEAK INSTABILITY.
GUSTY SFC WINDS OVER MAINLY THE NEB PANHANDLE THIS AFTERNOON...
DIMINISHING EARLY THIS EVENING. -RE-
PREV DISCUSSION... /ISSUED 420 AM MST THU FEB 23 2012/
UPDATE...
LATEST RADAR IMAGERY SHOWING PRECIPITATION SHIFTING SOUTH INTO
COLORADO WITH THE COLD FRONT. SNOTELS ARE NOT SHOWING MUCH IN THE
WAY OF ACCUMULATIONS ANYMORE. WENT AHEAD AND CANCELLED THE WINTER
STORM WARNINGS A LITTLE EARLIER THAN ANTICIPATED. UPDATES HAVE BEEN
SENT. -CLAYCOMB-
PREV DISCUSSION... /ISSUED 241 AM MST THU FEB 23 2012/
SHORT TERM...TODAY THROUGH SATURDAY NIGHT
CURRENTLY...COLD FRONT WELL INTO NORTHERN COLORADO THIS MORNING.
MESONET OBSERVATIONS SHOWING WINDS DECREASING UNDER WARNING
CRITERIA. SOME SPOTS IN THE PANHANDLE HAVE ALREADY BEEN HITTING
ADVISORY CRITERIA...SO WENT AHEAD AND STARTED THE WIND ADVISORY
FOR THE PANHANDLE NOW INSTEAD OF 5 AM AND CANCELLED THE HIGH WIND
WARNING. AREA OF SNOW DECREASING ON RADAR AS WELL WITH ONLY THE
SOUTHERN HALF OF THE CWA NOW SHOWING ANY ECHOES. LOOKS LIKE THE
WINTER STORM WARNING FOR THE SNOWY AND SIERRA MADRE RANGES WILL BE
GOOD TO EXPIRE AT 5 AM AS WELL. WILL GET SOME SNOW REPORTS OUT IN
LSR FORMAT ONCE THE FORECAST PACKAGE IS SENT OUT.
COLD FRONT FORECAST TO BE IN SOUTHERN COLORADO BY 18Z TODAY. WOULD
THINK MAJORITY OF SNOW WILL END EARLY THIS MORNING AS THE FRONT
CONTINUES SOUTH. WE STAY FAIRLY COLD TODAY AS 700MB TEMPERATURES
STAY FROM -14 TO -16C. HIGHS WILL STRUGGLE TO GET OUT OF THE 30S
TODAY EAST OF THE LARAMIE RANGE...PROBABLY STAY BELOW FREEZING WEST.
SEE A SLIGHT WARM UP FRIDAY AS UPPER RIDGE BUILDS INTO THE AREA.
700MB TEMPERATURES CLIMB TO AROUND -10C. LOOKING AT HIGHS IN THE
UPPER 30S WITH POSSIBLY LOW 40S IN THE PANHANDLE. RIDGE AXIS
PASSES AROUND 12Z SATURDAY.
LOOKS LIKE ANOTHER POSSIBLE HIGH WIND EVENT SATURDAY AFTER THE
RIDGE PASSES. 700MB WINDS INCREASE TO 45 KTS AT 12Z
SATURDAY...INCREASING TO 55/60KTS SATURDAY AFTERNOON. CRAIG TO
CASPER 700MB GRADIENT PRETTY TIGHT SATURDAY AFTERNOON...UP TO 100
MTRS AHEAD OF A FAST MOVING COLD FRONT POSITIONED IN WESTERN
WYOMING BY SATURDAY EVENING. WILL LET THE DAY SHIFT TAKE ANOTHER
LOOK TODAY FOR ANY WIND HEADLINES WITH THIS SYSTEM.
RUN TO RUN CONSISTENCY ON THE SUNDAY SYSTEM STILL TERRIBLE. BOTH
THE GFS AND ECMWF NOW HAVE THE UPPER SHORTWAVE NORTH ACROSS
SOUTHERN MONTANA AND SOUTH DAKOTA...NOT A VERY GOOD POSITION FOR
US TO GET A LOT OF SNOW. BUT THIS IS A GOOD LOCATION FOR CONTINUED
HIGH WINDS.
LONG TERM...SUNDAY THROUGH WEDNESDAY
SOUTHEAST WY WILL BE ON THE BACKSIDE OF THE EXITING STORM SYSTEM
ON SUNDAY. AS SUCH...TEMPERATURES WILL BE BELOW NORMAL WITH GFS
PROGGED 700MB TEMPS AROUND AROUND -14C. SOME LINGERING 700-500MB
MOISTURE WILL PRODUCE A CHANCE OF SNOW IN THE SIERRA MADRE/SNOWY
RANGES BUT ACCUMULATIONS WILL BE INSIGNIFICANT. WITH NORTHWESTERLY
700MB WINDS AROUND 40 KTS THROUGH SUNDAY AFTN ADVISORY LEVEL WINDS
MAY CONTINUE TO BE A CONCERN ACROSS THE NEBRASKA PANHANDLE. BY
MONDAY NIGHT...THE GFS AND ECMWF ARE IN GENERAL AGREEMENT IN
SHOWING A MIDLEVEL TROUGH DIGGING INTO THE INTERMOUNTAIN WEST AND
THEN PROGRESSING EASTWARD ACROSS CO ON TUESDAY. THE ECMWF IS
ABOUT 12 HOURS SLOWER WITH THE UPPER AND LOWER LEVEL FEATURES. BOTH
MODELS SHOW SFC PRESSURE FALLS ACROSS SE CO AND ASSOCIATED
FAVORABLE UPSLOPE N/NE LLVL WINDS OVER THE PLAINS. WILL NOT HIT
PRECIP CHANCES TOO HEAVILY AT THIS POINT SINCE IT IS ALMOST SIX
DAYS AWAY. HOWEVER...THIS STORM SYSTEM COULD BE THE NEXT MODERATE
SNOW MAKER FOR ALL AREAS OF THE CWA. MODEL FCSTS SHOW THE MID AND
UPPER LEVEL FLOW BECOMING MORE ZONAL AFTER THE PASSAGE OF THE TUES
TROUGH.
FIRE WEATHER...
NO FIRE WEATHER CONCERNS OVER THE NEXT FEW DAYS. NORTHWEST WINDS
THIS AFTERNOON WILL BE MODERATE TO STRONG...ESPECIALLY ACROSS THE
NEBRASKA PANHANDLE WHERE SUSTAINED WINDS 3O TO 35 MPH WITH GUSTS
TO 45 MPH ARE EXPECTED. MINIMUM AFTERNOON RELATIVE HUMIDITIES WILL
BE IN THE 40 TO 50 PERCENT RANGE TO THE EAST OF THE LARAMIE RANGE.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...WIND ADVISORY UNTIL 5 PM THURSDAY FOR NEZ002-NEZ003-NEZ019-
NEZ020-NEZ021-NEZ054-NEZ055-NEZ095-NEZ096.
&&
$$
SHORT TERM/FIRE WEATHER...CLAYCOMB
LONG TERM...FINCH