Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/06/13
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
810 PM MST TUE FEB 5 2013
.UPDATE...HIGH CLOUDS WILL CONTINUE TO STREAM ACROSS NORTHERN
COLORADO AS MOISTURE AT THE UPPER LEVELS OF THE AIRMASS PASS
THROUGH THE RIDGE THAT`S OVER COLORADO. WILL INCREASE THE CLOUD
COVER IN THE FORECAST. REST OF THE FORECAST LOOKS ON TRACK AND DO
NOT PLAN ON MAKING ANY OTHER CHANGES.
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL THROUGH WEDNESDAY. HIGH
CLOUDS WILL PERSIST THROUGH THE NEXT 24 HOURS. SOUTHERLY WINDS
GUSTING TO 25 KNOTS AT KDEN AND KAPA WILL SLOWLY DECREASE TO 10-15
KNOTS THROUGH 06Z. WINDS WILL SHIFT TO THE NORTH EARLY WEDNESDAY
AFTERNOON BEHIND A WEAK COLD FRONT. A WEAK UPPER LEVEL DISTURBANCE
WILL INCREASE MID LEVEL CLOUDS AND POSSIBLY BRING LIGHT SNOW AND
LOW CLOUDS WEDNESDAY EVENING. BEST CHANCE FOR SNOW AND LOW CLOUDS
WILL BE AT KAPA AND SOUTH.
&&
.PREV DISCUSSION... /ISSUED 305 PM MST TUE FEB 5 2013/
SHORT TERM...NORTHWEST FLOW ALOFT ACROSS REGION AT THIS
TIME...GRADUALLY BECOMING A BIT MORE WESTERLY ACCORDING TO THE
PLATTEVILLE PROFILER. WINDS ALOFT NOT ALL THAT STRONG...WITH CROSS
MOUNTAIN FLOW AROUND 20 KTS AT MOUNTAIN TOP. A FEW GUSTS TOPPING
30-35 MPH ACROSS THE RIDGES AND HIGHER FOOTHILLS. ACROSS PLAINS
WEAK MESOCYCLONE IN THE DENVER AREA KEEPING SOUTHEAST WINDS ACROSS
MUCH OF THE AREA. SOME INCREASE IN HIGH LEVEL MOISTURE WITH A BIT
OF A WAVE CLOUD ALONG FOOTHILLS. FLOW ALOFT TO BECOME WESTERLY
TONIGHT AS UPPER TROUGH MOVES INTO THE NORTHERN GREAT BASIN.
WINDS ALOFT INCREASE SLIGHTLY...WITH LATEST RAP SHOWING CROSS
MOUNTAIN FLOW INCREASING TO 30 KTS. SHOULD SEE SOME INCREASE IN
WINDS ACROSS THE MOUNTAINS AND ALONG FOOTHILLS. MOISTURE TO
CONTINUE TO INCREASE WITH LATEST WRF SYNTHETIC SATELLITE IMAGERY
INDICATING WAVE CLOUD TO BECOME MORE PRONOUNCED ALONG FOOTHILLS
AND ADJACENT PLAINS OVERNIGHT. THIS INCREASE IN CLOUD SHOULD KEEP
MINS FAIRLY MILD IN AND NEAR FOOTHILLS. ON WEDNESDAY...UPPER
TROUGH EXPECTED TO PUSH ACROSS THE GREAT BASIN DURING THE MORNING
AND OVER WESTERN COLORADO AND WESTERN WYOMING BY THE EVENING.
MODEL CROSS SECTIONS CONTINUE TO INDICATE A GRADUAL DEEPENING OF
THE MOISTURE ACROSS THE MOUNTAINS THROUGH THE DAY. QG VERTICAL
VELOCITY PROGS SHOW SOME INCREASE IN MID LEVEL QG ASCENT. THERE
IS SOME INDICATION OF WEAK COLD AIR ADVECTION WITH LAPSE RATES
AND OROGRAPHICS GRADUALLY IMPROVING DURING THE AFTERNOON. SHOULD
BE ENOUGH FOR SOME CHANCE OF SNOW SHOWERS OVER THE MOUNTAINS BY
THE AFTERNOON. ANY ACCUMULATIONS WILL BE LIGHT AND CONFINED TO
WEST FACING SLOPES. ACROSS PLAINS...MODELS STILL HINTING AT WEAK
SURGE DURING THE AFTERNOON. GFS CONTINUES TO BE THE DEEPEST AND
STRONGEST WITH THIS SURGE...ALONG WITH CONSIDERABLE MORE MOISTURE.
LATEST CANADIAN ALSO INDICATING SOME CHANCE FOR PRECIPITATION
SPREADING ONTO THE ADJACENT PLAINS. AT THIS TIME IT APPEARS THAT
LOW LEVELS TO REMAIN FAIRLY DRY...WHICH SHOULD LIMIT PRECIP
CHANCES ALONG THE URBAN CORRIDOR. BETTER CHANCE FOR VIRGA WITH THE
DRIER LOW LEVELS WITH THE POTENTIAL FOR A FEW RAIN AND OR SNOW
SHOWERS ACROSS THE PALMER DIVIDE LATER IN THE AFTERNOON.
TEMPERATURES TO BE A FEW DEGREES COOLER DUE TO THE INCREASED
CLOUD COVER. GUIDANCE TEMPERATURES SEEM A FEW DEGREES TOO WARM.
LONG TERM...MODELS ARE STILL SHOWING AN UPPER TROUGH AXIS MOVING
EASTWARD ACROSS THE CWA WEDNESDAY EVENING. THE FLOW BEHIND THE
UPPER TROUGH IS ZONAL AND PRETTY WEAK. THIS CONTINUES THURSDAY
INTO THURSDAY EVENING WITH A WEAK UPPER RIDGE MOVING OVER THE
FORECAST AREA. THE FLOW ALOFT BECOMES WEST-SOUTHWESTERLY AND
INCREASES THURSDAY NIGHT AND FRIDAY. ON FRIDAY NIGHT...THERE IS A
SOUTHWESTERLY JET MAXIMUM OVER THE CWA. THE QG VERTICAL VELOCITY
FIELDS HAVE WEAK DOWNWARD ENERGY PROGGED FOR THE CWA WEDNESDAY
NIGHT THROUGH THURSDAY EVENING. AFTER THAT...UPWARD MOTION IS
PROGGED TO MOVE INTO COLORADO. IT IS PRETTY WEAK FRIDAY INTO EARLY
EVENING...THEN INCREASES A BIT AND CONTINUES WELL INTO THE
EXTENDED PERIOD. THE BOUNDARY LAYER FLOW IS PROGGED TO BE UPSLOPE
FOR THE PLAINS AND FOOTHILLS WEDNESDAY EVENING. LATER WEDNESDAY
NIGHT...CONTINUING INTO FRIDAY MORNING...NORMAL DIURNAL WIND
PATTERNS ARE LIKELY. ON FRIDAY...INTO THE EVENING...SOUTHWESTERLY
DOWNSLOPING WINDS DOMINATE. SOMETIME BETWEEN 06Z AND 12Z FRIDAY
OVERNIGHT/SATURDAY MORNING...A COLD FRONT WITH UPSLOPE BEHIND IT
IS TO MOVE INTO THE CWA. FOR MOISTURE...THE GFS HAS A DECENT
AMOUNT OVER THE FOOTHILLS AND PLAINS WEDNESDAY EVENING. THE NAM IS
WAY DRIER...AND THE ECMWF HAS SOME BUT ONLY IN THE MID AN UPPER
LEVELS. LATER WEDNESDAY NIGHT INTO EARLY THURSDAY EVENING IT IS
PRETTY DRY. MOISTURE BEGINS TO GRADUALLY INCREASE LATER THURSDAY
NIGHT TROUGH FRIDAY NIGHT...MAINLY OVER THE MOUNTAINS. THE QPF
FIELDS NOW SHOW MORE MEASURABLE PRECIPITATION OVER THE CWA THEN
THEY INDICATED ON YESTERDAY`S 12Z RUNS. IN THE FACT...THE GFS
SHOWS A FAIRLY DECENT AMOUNT OF SNOW OVER THE SOUTHWESTERN AND
SOUTH CENTRAL CWA...INCLUDING THE PALMER RIDGE UP INTO THE
WESTERN URBAN CORRIDOR. THE ECMWF SHOWS LESS...WITH NOTHING ON
NAM. THERE IS ALSO A TAD OF MEASURABLE PRECIPITATION OVER THE
MOUNTAINS FRIDAY NIGHT. FOR POPS WEDNESDAY EVENING...WILL GO WITH
20-50% IN APPROPRIATE AREAS. CONSIDERING LAST WEEK`S STORM WILL
COMPLETELY DISCOUNT THE NAM. IT`S PERFORMANCE WAS MISERABLE. NO
POPS THE THE REST OF WEDNESDAY NIGHT THROUGH FRIDAY. WILL BRING
MINOR POPS IN FRIDAY NIGHT WITH THE NEXT STORM. FOR
TEMPERATURES...THURSDAY`S HIGHS ARE 0-2 C COLDER THAN
WEDNESDAY`S. FRIDAY`S HIGHS ARE 1-3 C WARMER THAN THURSDAY`S. FOR
THE LATER DAYS...SATURDAY THROUGH TUESDAY...MODELS CONTINUE TO
INDICATE A DECENT UPPER TROUGH/CLOSED LOW TO AFFECT THE CWA FRIDAY
NIGHT INTO MONDAY. THE GFS AND ECMWF BOTH SHOW A CLOSED
CIRCULATION NEAR THE FOUR CORNERS ON SATURDAY. THE ECMWF HAS IT
OVER NORTHWESTERN KANSAS BY EARLY SUNDAY MORNING...THE GFS KEEPS
AROUND THE FOUR CORNERS THROUGH 12Z SUNDAY MORNING. BY 00Z SUNDAY
AFTERNOON LATE...THE GFS HAS IT OVER SOUTHWESTERN KANSAS...THE
ECMWF HAS IT OVER NORTH DAKOTA AND MINNESOTA. THEY BOTH STILL
KEEP AN UPPER TROUGH OVER COLORADO ALL THAT TIME CONTINUING THROUGH
MONDAY NIGHT. THE CANADIAN LOOKS MORE LIKE THE ECMWF CONCERNING
THE CIRCULATION CENTER(S)...BUT IT ALSO KEEPS AN UPPER TROUGH OVER
THE CWA THROUGH MONDAY. CERTAIN PARAMETERS BETWEEN THE MODELS ARE
STILL NOT IN SYNC BUT THERE IS A DECENT PROLONGED PERIOD OF
UPSLOPE FOR AREAS EAST OF THE DIVIDE...THERE IS DEEP MOISTURE...
THERE IS FAIRLY COLD AIR AND THERE IS SYNOPTIC SCALE ENERGY.
CONFIDENCE OF SNOWFALL IS INCREASING.
AVIATION...SOUTHEAST WINDS ACROSS THE DENVER AREA BEGINNING TO
SHOW SIGNS OF BECOMING MORE SOUTHERLY AS WEAK MESOCYCLONE OVER
NORTH DENVER WEAKENS AND MOVES NORTHWARD. LATEST RAP AND HRRR
STILL SHOWING MORE OF A SOUTHEAST COMPONENT AT THE AREA AIRPORTS
FOR THE NEXT FEW HOURS...AND THIS STILL SEEMS REASONABLE. WINDS TO
THEN BECOME MORE SOUTH SOUTHWEST DURING THE EVENING AS DRAINAGE
FLOW BEGINS TO DOMINATE. SPEEDS SHOULD REMAIN AROUND 8 KTS OR
LESS. MID AND HIGH LEVEL MOISTURE TO GRADUALLY INCREASE OVERNIGHT
WITH WAVE CLOUD ALONG INCREASING IN COVERAGE BY THE MORNING.
CEILINGS SHOULD REMAIN ABOVE 12000 FEET. ON WEDNESDAY...WINDS TO
BECOME MORE SOUTHWEST AND INCREASE TO 10 KTS BY 15Z...SHIFTING TO
THE NORTHWEST BY 19Z. WINDS TO BECOME MORE NORTHERLY AROUND 21Z AS
WEAK SURGE MOVES ACROSS THE REGION. MID LEVEL CLOUDS TO GRADUALLY
LOWER DURING THE DAY WITH 9000 FEET AGL CEILING BY 21Z. SLIGHT
CHANCE OF CEILINGS AROUND 6000 FEET AGL DEVELOPING LATE IN THE
DAY...WILL CONTINUE TO KEEP A SCATTERED CEILING.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....RJK
AVIATION...MEIER
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
328 PM MST MON FEB 4 2013
.SHORT TERM...MODERATE NORTHWEST FLOW ALOFT TO CONTINUE OVER THE
AREA THROUGH TONIGHT. CROSS MOUNTAIN FLOW HAS INCREASED TO AROUND
40 KTS JUST ABOVE MOUNTAIN TOP...WITH SOME GUSTS TO 50 MPH
OBSERVED ATOP LOVELAND PASS. GUSTS IN THE 30S WERE COMMON ALONG
THE FOOTHILLS. WESTERLY WINDS HAVE ALSO PUSHED ACROSS THE URBAN
CORRIDER WITH NORTHWEST WINDS ALONG THE WYOMING AND NEBRASKA
PANHANDLES. LASTEST RAP CROSS SECTIONS SHOW CROSS MOUNTAIN FLOW
GRADUALLY DECREASING TO 30 KTS DURING THE EVENING...THUS WINDS
SHOULD GRADUALLY DECREASE AS A RESULT WITH DRAINAGE PATTERN
PREVAILING. WAVE CLOUD ALONG FOOTHILLS AND URBAN CORRIDOR
BEGINNING TO DISSIPATE. LATEST WRF SYNTHETIC SATELLITE IMAGERY
SUGGESTING A DECREASE IN THE WAVE CLOUD THROUGH THE EVENING. THUS
SKIES SHOULD GRADUALLY CLEAR. ON TUESDAY...FLOW ALOFT BECOMES A
BIT MORE WESTERLY AS A WEAK TROUGH MOVES ACROSS WYOMING. SOME
INCREASE IN HIGH LEVEL MOISTURE THROUGH THE DAY...WITH PERHAPS
SOME DEVELOPMENT OF A WAVE CLOUD ALONG FOOTHILLS. NAM CROSS
SECTIONS SHOW CROSS MOUNTAIN FLOW OF AROUND 35 KTS...COULD SEE
SOME GUSTS AROUND 40 MPH AGAIN ACROSS THE RIDGES AND HIGHER
FOOTHILLS. ACROSS PLAINS....LATEST MODELS SUGGEST A WEAK SURFACE
HIGH MOVING INTO THE AREA DURING THE AFTERNOON...WHICH COULD PUSH
EASTERLY SURFACE WINDS AS FAR WEST AS THE FOOTHILLS. NOT ALOT OF
COOLING ASSOCIATED WITH THIS HIGH...SO TEMPERATURES TO CLIMB INTO
THE 50S WITH PERHAPS A FEW 60S IN THE DENVER VICINITY.
.LONG TERM...MODELS HAVE ZONAL FLOW ALOFT FOR THE CWA TUESDAY
NIGHT...THEN WEST-SOUTHWESTERLY FLOW WEDNESDAY MORNING. A VERY
WEAK UPPER TROUGH IS PROGGED TO MOVE ACROSS THE FORECAST AREA
WEDNESDAY AFTERNOON AND EVENING. FOR WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT...MODERATE ZONAL FLOW IS PROGGED. THE SYNOPTIC
SCALE ENERGY IS WEAK THROUGH THE PERIODS. THE BOUNDARY LAYER FLOW
WILL TEND TOWARDS DOWNSLOPING TUESDAY NIGHT AND WEDNESDAY. BY
WEDNESDAY AFTERNOON AND EVENING...THERE IS A BRIEF SHOT OF
UPSLOPE FOR THE PLAINS INTO THE FOOTHILLS. ON THURSDAY...NORMAL
DUIRNAL TRENDS ARE LIKELY. CONCERNING MOISTURE...THERE IS SOME IN
THE MID AND UPPER LEVELS TUESDAY NIGHT. THE NAM AND ECMWF HAVE
LIMITED MOISTURE ON WEDNESDAY AND WEDNESDAY EVENING WITH THE WEAK
UPPER TROUGH. HOWEVER...THE GFS HAS CONSIDERABLY MORE MOISTURE ON
WEDNESDAY AND WEDNESDAY EVENING. THURSDAY AND THURSDAY NIGHT LOOK
PRETTY DRY ON ALL THE MODELS. THE QPF FIELDS FROM THE GFS AND ECMWF
HAVE A TAD OF MEASURABLE SNOWFALL OVER THE SOUTHWESTERN PART OF
THE CWA WEDNESDAY AFTERNOON AND EVENING. FOR POPS...WILL KEEP A
TAD IN OVER THE HIGH MOUNTAINS WEDNESDAY AND WEDNESDAY EVENING.
FOR TEMPERATURES...WEDNESDAY`S HIGHS ARE 1-3 C COOLER THAN
TUESDAY`S. THURSDAY`S HIGHS ARE CLOSE TO WEDNESDAY`S. FOR THE
LATER DAYS...FRIDAY THROUGH MONDAY...MODELS SHOW INCREASING
SOUTHWESTERLY FLOW ALOFT ON FRIDAY. ON SATURDAY...MODELS HAVE A
CLOSED LOW OVER CENTRAL UTAH AROUND MID DAY. BY SUNDAY MORNING AT
12Z...MODELS ARE ALL OVER THE PLACE WITH THE SYSTEM. THE GFS HAS
THE CLOSED LOW CENTER OVER NORTHERN ARIZONA...THE ECMWF OVER THE
NORTHWESTERN CORNER OF KANSAS...THE CANADIAN OVER THE SOUTHEASTERN
CORNER OF COLORADO. AT 12Z MONDAY MORNING...THERE IS AN UPPER
TROUGH AXIS STRETCHED NORTHEAST TO SOUTHWEST ACROSS THE CWA WITH
THE GFS STILL SHOWING A WEAKENING CLOSED CIRCULATION OVER EAST
CENTRAL ARIZONA. OVERALL AGREEMENT IS QUITE POOR. THE COLD AIR IS
STILL INDICATED TO GET INTO THE CWA BY EARLY SATURDAY MORNING.
HOWEVER...THE TIMING WITH THE MOISTURE IS NEARLY 24 HOURS LATER
THAN YESTEDAY`S 12Z RUNS INDICATED. THE CANADIAN STILL LOOKS TO
GIVE THE PLAINS A DECENT SNOWFALL...THE REST NOT. OVERALL...IT IS
A CONVOLUTED MESS. HOPEFULLY AS TIME MOVES FORWARD...THE MODELS
IMPROVE CONCERNING CONSENSUS. WILL LEAVE POPS IN THE 20-40% RANGE
FOR NOW FROM SATURDAY AFTERNOON INTO SUNDAY EVENING.
&&
.AVIATION...WESTERLY WINDS HAVE PUSHED ACROSS BJC AND DIA WITH
SOME GUSTS TO 25 KTS. LIGHTER WINDS NOTED AT APA. WINDS TO
CONTINUE WESTERLY AT DEN AND BJC INTO THE EVENING HOURS BEFORE
DECREASING AND BECOMING SOUTHWEST BY 03Z. WINDS SHOULD REMAIN
LIGHT WESTERLY AT APA...THEN SOUTHERLY DURING THE EVENING. MID AND
HIGH LEVEL MOISTURE TO GRADUALLY DECREASE DURING THE EVENING AS
THE WAVE CLOUD CONTINUES TO DISSIPATE. ON TUESDAY...SOUTHERLY
WINDS TO PREVAIL BY 16Z...AND COULD SHIFT TO THE SOUTHEAST BY 20Z.
SPEEDS OF AROUND 8 KTS WILL PREVAIL.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....RJK
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
959 AM MST MON FEB 4 2013
.UPDATE...
&&
.SHORT TERM...CURRENT FORECASTS STILL LOOK REASONABLE. MODERATE
NORTHWEST FLOW ALOFT TO CONTINUE ACROSS COLORADO THROUGH TONIGHT.
LATEST RAP QG VERTICAL VELOCITY PROGS SHOW WEAK MID LEVEL DESCENT
ACROSS THE REGION...AIDING IN GUSTY WINDS ACROSS THE HIGHER RIDGES
AND ALONG FOOTHILLS. MODELS INDICATING CROSS MOUNTAIN FLOW OF
AROUND 30 KTS...SO GUSTS UP TO 50 MPH NOT OUT OF THE QUESTION IN
THE WIND PRONE AREAS. ACROSS PLAINS...SOUTHEAST GRADIENT WEAKENING
AND SHOULD BECOME NORTHWEST BY THE AFTERNOON. LATEST SYNTHETIC
SATELLITE IMAGERY SUGGESTING A BIT MORE CLOUD COVER ALONG THE
FRONT RANGE THROUGH THE DAY. MAY NEED TO INCREASE CLOUD COVER A
BIT. DON`T THINK THE CLOUDS WILL AFFECT THE EXPECTED TEMPERATURES.
&&
.AVIATION...SOUTHEAST GRADIENT STILL IN PLACE ACROSS THE AREA...
SHOWING SIGNS OF WEAKENING. TREND FOR THE WINDS TO BECOME
SOUTHWEST THEN NORTHWEST STILL ON TRACK THOUGH TIMING TO BE
DELAYED A FEW HOURS. SPEEDS SEEM REASONABLE AT THIS TIME. THERE
MAY ALSO BE A BIT MORE WAVE CLOUD ALONG THE FOOTHILLS...THOUGH
CEILINGS SHOULD REMAIN ABOVE 12000 FEET.
&&
.PREV DISCUSSION... /ISSUED 336 AM MST MON FEB 4 2013/
SHORT TERM...NORTHERN COLORADO WILL BE UNDER A MODERATE NORTHWEST
FLOW PATTERN TODAY AND TONIGHT BEHIND LAST EVENINGS WEAK UPPER
WAVE. THERE IS SOME MID AND HIGH LEVEL MOISTURE OVER THE NORTHERN
ROCKIES WHICH WILL MOVE INTO COLORADO DURING THE DAY IN THE FLOW.
THE WRF SIMULATED SATELLITE IMAGERY SHOWING SOME WAVE CLOUDS OVER
THE FRONT RANGE BUT NOT THAT EXTENSIVE AND WOULD APPEAR A PARTLY
CLOUDY FORECAST SHOULD HANDLE THE AFTERNOON CONDITIONS. THE LOWER
LEVELS OF THE ATMOSPHERE WILL REMAIN DRY SO NO PRECIP OVER NEXT 24
HOURS. GIVEN THE STRENGTH OF FLOW...EXPECT SOME GUSTY WINDS OVER
THE HIGHER MOUNTAINS AND EAST SLOPES. CROSS SECTIONS SHOWING CROSS
BARRIER FLOW OF AROUND 30KT... ESPECIALLY THIS AFTERNOON AND
TONIGHT WHICH WILL RESULT IN SOME GUSTS UP TO 40-50 MPH IN WIND
PRONE AREAS.
LONG TERM...WLY FLOW ALOFT WILL BE OVER NRN CO ON TUE WITH ONLY
SOME HIGHER LEVEL MOISTURE EMBEDDED IN THE FLOW SO WILL KEEP FCST
DRY. HIGHS SHOULD RISE INTO THE 50S ON TUE ACROSS NERN CO WITH
NEAR 60 POSSIBLE AROUND DENVER. BY WED A WK UPPER LEVEL TROUGH
WILL QUICKLY MOVE ACROSS THE AREA WITH SOME INCREASE IN MID LVL
MOISTURE WHICH MAY BRING A SLIGHT CHC OF SNOW IN THE MTNS. A CDFNT
WILL MOVE ACROSS NERN CO FM MID AFTN INTO THE EVENING HOURS. WILL
KEEP HIGHS MAINLY IN THE LOWER TO 50S OVER THE PLAINS. LATEST
ECMWF AND GFS SHOWS SOME LIGHT PCPN IN THE SRN FOOTHILLS WED
EVENING WHERE UPSLOPE FLOW IS ENHANCED SO MAY NEED SOME LOW POPS N
THIS AREA.
BY THU THE FLOW ALOFT WILL BE WLY WITH A DRY AIRMASS IN PLACE SO
WILL NOT MENTION ANY PCPN. 850-700 MB TEMPS ARE A FEW DEGREES
LOWER SO WILL KEEP HIGHS IN THE UPPER 40S TO LOWER 50S ACROSS NERN
CO. FOR FRI THE FLOW ALOFT WILL BECOME MORE SWLY AS AN UPPER LEVEL
STORM SYSTEM DEVELOPS OVER THE WRN US. AT THIS TIME IT LOOKS LIKE
ONLY SOME HIGHER LEVEL MOISTURE WILL AFFECT THE AREA SO WILL NOT
MENTION ANY PCPN IN THE MTNS THRU THE AFTN HOURS. HIGHS SHOULD BE
IN THE LOWER TO MID 50S ACROSS NERN CO BASED ON CURRENT 850-700 MB
TEMPS.
FOR THE WEEKEND ONCE AGAIN THERE IS A LOT OF UNCERTAINTY ON WHERE
THE UPPER LEVEL LOW OVER THE WRN US WILL MOVE AND HOW FAST. THE
LATST GFS HAS A SPLITTING SYTEM WITH ONE PIECE OF ENERGY TRACKING
ACROSS NERN CO BY SAT NIGHT WHILE THE 2ND PIECE OF ENERGY
EVENTUALLY DROPS SOUTHWARD INTO ARIZONA BY SUN. IF THIS HAPPENS
THE BEST CHC OF PCPN WOULD PROBABLY BE SAT NIGHT WITH LIMITED
SNOWFALL. MEANWHILE THE ECMWF AND GEM HAVE A MORE CONSOLIDATED
SYSTEM NEAR THE FOUR CORNERS SAT NIGHT WHICH MOVES ACROSS SRN
COLORADO INTO SWRN KANSAS BY SUN AFTN. NATURALLY IF THIS WERE TO
HAPPEN THEN NRN CO WOULD BE UNDER THE GUN FOR A SIGNIFICANT WINTER
STORM. THE LONGER RANGE MODELS HAVE BEEN ALL OVER THE PLACE THE
LAST 3 NIGHTS WITH THIS SYSTEM AND WITH IT STILL WAY OUT OVER
THE PACIFIC OCEAN CONFIDENCE IS NOT VERY HIGH AS TO WHAT MAY
EVENTUALLY TRANSPIRE. AT THIS POINT THE BEST WAY TO GO IS TO KEEP
A CHC OF SNOW IN THE MTNS SAT THRU SUN WITH A SLIGHT CHC ELSEWHERE
UNTIL IT BECOMES MORE CLEAR HOW THINGS ARE GOING TO EVOLVE.
AVIATION...VFR CONDITIONS THROUGH TONIGHT WITH SOME WAVE
CLOUDINESS THROUGH THE PERIOD...ESPECIALLY THIS AFTERNOON AND
EVENING. SURFACE WINDS AGAIN STARTING FROM THE SOUTH AND SOUTHWEST
AND APPEARS ENOUGH WEST TO EAST SURFACE GRADIENT AND LOW LEVEL
MIXING FOR WINDS SHIFTING WEST AND NORTHWEST THIS AFTERNOON. WINDS
WOULD BE STRONGEST AT BJC.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....RPK
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS ALBANY NY
930 PM EST TUE FEB 5 2013
.SYNOPSIS...
A CLIPPER SYSTEM WILL APPROACH AND MOVE ACROSS THE REGION
TONIGHT...BRINGING SOME VERY LIGHT SNOW TO THE AREA. FAIR WEATHER
IS EXPECTED MID WEEK AS HIGH PRESSURE BUILDS IN. A WIDESPREAD
SNOWFALL IS ANTICIPATED FOR THE LATER HALF OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 930 PM...LATEST RADAR AND SURFACE OBSERVATIONS ARE SHOWING
SOME LIGHT SNOW SHOWERS ACROSS AREAS SOUTH OF THE CAPITAL
DISTRICT. THE LATEST RADAR TRENDS HAVE WEAKENED FROM A FEW HOURS
AGO. OVERALL THE SNOW ACCUMULATION WILL BE VERY LIGHT...GENERALLY
A COATING AT MOST LOCATIONS. LOOKING AT THE BIGGER PICTURE...THE
SNOW SHOWERS WEST OF THE AREA ARE STARTING TO WEAKEN AS THEY ARE
RUNNING INTO DRIER AIR. LATEST SURFACE OBSERVATIONS SHOWING A
SPREAD BETWEEN TEMPS AND DEWPOINTS. 00Z ALY SOUNDING VERY DRY WITH
AN INVERSION AT 800 MB. OVERALL WILL ADJUST OVERNIGHT QPF VALUES
WITH THE CLIPPER. WILL KEEP HIGH CHANCE POPS OF SNOW SHOWERS...BUT
NOT EXPECTING TOO MUCH IN ACCUMULATION.
PREV DISC... PER THE H2O VAPOR LOOP ANALYSIS...A FAST MOVING
SHORT WAVE WAS CROSSING THE LOWER GREAT LAKES REGION THIS
AFTERNOON. REGIONAL RADARS SHOW A SCT-BKN LINE OF PRECIPITATION
THAT WAS ASSOCIATED WITH WEAK FORCING. THIS FORCING IS EXPECTED TO
REMAIN QUASI- FOCUSED AS IT MIGRATES ACROSS THE CWFA. EXPERIENTIAL
FORECAST REFLECTIVITIES LEAD BY THE HRRR ALL SUGGEST A SCATTERED
NATURE TO THE SNOWFALL TONIGHT. ALONG WITH THE MOS GUIDANCE...WE
WILL DROP BACK POPS TO THE HIGH CHC-SCT CATEGORY WITH
ACCUMULATIONS LESS THAN 1 INCH FOR MOST LOCATIONS. THE CLOUD COVER
WILL LIKELY REMAIN EXTENSIVE OVERNIGHT WHICH SHOULD KEEP TEMPS A
LITTLE MILDER THAN THIS MORNINGS VALUES.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
WEDNESDAY...
MINOR LAKE EFFECT SNOW EVENT WILL BE POSSIBLE FOR PORTIONS OF THE
MOHAWK VALLEY AND ADIRONDACKS IN THE MORNING BEFORE THOSE
INVERSION HEIGHTS COLLAPSE TOWARD NOON. OTHERWISE...VARIABLE CLOUD
COVER WILL BEGIN TO SLOWLY IMPROVE THROUGH THE DAY AS TEMPERATURES
CLIMB INTO THE LOW-MID 30S FOR VALLEY LOCATIONS AND 20S ELSEWHERE.
WINDS WILL BE RATHER GUSTY THROUGH THE DAY AS WE MIX UP TO 30KT
MAGNITUDES. FURTHERMORE...THOSE WINDS MAY GET FUNNELED DOWN THE
MOHAWK RIVER FOR A SLIGHT ENHANCEMENT TO THOSE WESTERLY WINDS
THROUGH THE DAY.
WEDNESDAY NIGHT...
RIDGE OF HIGH PRESSURE WILL CREST OVER THE REGION. THIS WILL ALLOW
FOR...INITIALLY...CLEAR SKIES THROUGH THE EVENING HOURS WHICH WILL
SEND TEMPS QUICKLY DOWNWARD WITH NEAR IDEAL RADIATIONAL COOLING
/CLEAR SKIES AND LIGHT WINDS WITH A FROZEN AND PARTIAL SNOW
COVERED GROUND/. THEN WE WILL WATCH UPSTREAM CONDITIONS CLOSELY AS
STRONG PACIFIC ENERGY COMES ASHORE AND TRACKS ACROSS THE CENTER OF
THE NATION. NCEP MODEL SUITE ALONG WITH INTERNATIONAL GUIDANCE ARE
IN RATHER GOOD AGREEMENT WITH BROAD WARM ADVECTION ALOFT TO
COMMENCE OVERNIGHT WEDNESDAY INTO SUNRISE THURSDAY MORNING.
ISENTROPIC ANALYSIS ON THE 285-290K SURFACE SUPPORTS BROAD
ISENTROPIC LIFT AND SLOWLY LOWERING CPD/S TO RESULT WITH AN
INCREASE OF CLOUD COVER. THESE CLOUDS SHOULD LIMIT FURTHER
DECLINES IN THE TEMPERATURES OVERNIGHT AND MAY EVEN SEE A SLOW
REBOUND TOWARD SUNRISE.
THURSDAY...
THE AFOREMENTIONED ISENTROPIC LIFT CONTINUES THROUGH THE DAY
THURSDAY WITH A CONTINUE DECREASE IN THOSE CPD/S. THIS SHOULD
RESULT IN THE THICKENING AND LOWERING OF THE CLOUD DECK AND THE
CHANCE FOR OVERRUNNING LIGHT SNOW TO DEVELOP. WHILE MODEL QPF
SIGNALS ARE NOT SHOWING THIS ACROSS OUR REGION /THEY DO SO FURTHER
UPSTREAM/...THE COMBINATION OF CONTINUED ISENTROPIC LIFT AND LESS
THAN 30MB CPD/S...WE WILL PLACE CHC POPS ACROSS THE NORTHERN 1/2
OF THE CWFA BEGINNING BY LATE MORNING. THE BEST CHANCE FOR AN
ACCUMULATING SNOWFALL WILL LIKELY REMAIN ALONG AND NORTH OF I90
WHERE THE BEST LIFT AND MOISTURE PROFILES ARE EXPECTED AND VALUES
UP TO 1 INCH POSSIBLE. AS FOR TEMPERATURES...THE LOW LEVEL
AGEOSTROPHIC FLOW DOES INCREASE FROM THE NORTH AND THIS TOO SHOULD
LIMIT TEMPERATURES FROM GETTING OUT OF THE 20S.
THURSDAY NIGHT...
THIS WILL BE THE PERIOD OF TRANSITION TO A POTENTIAL STORM
IMPACTING THE REGION. GLOBAL MODEL TRENDS AND THE PERSISTENT ECMWF
FOR THE PAST 5 RUNS WANT TO PHASE THE NORTHERN STREAM PACIFIC
ENERGY WITH SOUTHERN STREAM WAVE/S/ ACROSS BAJA AND NORTHERN
MEXICO. LOW LEVEL SOUTHERLY JET AND MOISTURE TRANSPORT VECTORS
INCREASE RATHER RAPIDLY THURSDAY NIGHT WHERE THE CHANCE FOR LIGHT
SNOW TO INCREASE ACROSS THE REGION. GIVEN THE FORECAST WIND
TRAJECTORY AND MAGNITUDES...WE WILL FAVOR THE HIGHER TERRAIN WITH
LIKELY POPS AND HIGH CHANCE FOR THE VALLEY LOCATIONS. AS FOR
NOW...SNOWFALL AMOUNTS OF 1-2 INCHES WITH THE POSSIBILITY OF SOME
HIGHER TOTALS IN THE MOUNTAINS. GUIDANCE NUMBERS ARE FAIRLY CLOSE
AS WE LEANED MORE TOWARD THE GFS/ECMWF MOS NUMBERS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
HPC GUIDANCE. MOST MODELS NOW ON BOARD WITH A MAJOR WINTER EVENT
FOR THE END OF THE WEEK. LOW PRESSURE WILL BE NEAR VIRGINIA BEACH
AT THE START OF THE PERIOD...WITH SNOW ALREADY OVERSPREADING OUR
FORECAST AREA. THE LOW WILL TRACK TO SOUTH OF WESTERN NOVA SCOTIA
BY SATURDAY MORNING...INTENSIFYING RAPIDLY. A PERIOD OF RAIN OR A
SNOW MIX IS A POSSIBILITY BRIEFLY DURING THE DAY ON FRIDAY IN THE
LOWER SECTION OF THE MID HUDSON VALLEY...BUT FOR NOW WILL SAY IT IS
ALL SNOW. OTHERWISE...AN ALL-SNOW EVENT IS ANTICIPATED WITH
CONFIDENCE...WITH ACTIVITY WINDING DOWN SWIFTLY DURING THE DAY ON
FRIDAY. A FLOW TURNING NORTHERLY ENHANCED BY STRONG HIGH PRESSURE
MOVING IN BY SUNDAY ENSURES THAT WE HAVE AN ALL-SNOW EVENT BEYOND
FRIDAY AFTERNOON.
AS IT LOOKS RIGHT NOW...THE LOW IS EXPECTED TO STAY WELL ENOUGH TO
THE SOUTH...SUCH THAT 6 TO 10 INCHES OF TOTAL SNOW ACCUMULATION
LOOKS MOST REASONABLE...WITH THE GREATER AMOUNTS...OF COURSE...TO
THE SOUTH AND EAST IN OUR FORECAST AREA. MORE IS POSSIBLE...BUT SO
IS LESS...DEPENDING ON HOW THE SYSTEM EVOLVES. THIS LOOKS TO BE A
BROAD-AREA SNOW-PRODUCER.
BY SATURDAY NIGHT...SKIES WILL BE MOSTLY ON THE PARTLY CLOUDY
SIDE...WITH WINDS RAPIDLY DIMINISHING TO MAKE THE NIGHT A COLD ONE.
BUT THE REPRIEVE WILL BE BRIEF AS ANOTHER SYSTEM THREATENS THE
REGION WITH A WINTRY MIX OF PRECIPITATION FOR MONDAY/MONDAY NIGHT.
A COLD FRONT SLIDES THROUGH THE REGION...WITH TUESDAY BEGINNING A
PERIOD OF LAKE EFFECT SNOW SHOWERS...MAINLY WEST OF THE CAPITAL
REGION.
HIGH TEMPERATURES WILL RANGE FROM THE MID 20S IN THE ADIRONDACKS AND
GREENS...TO THE UPPER 30S IN THE LOWER MID HUDSON VALLEY. ON
SATURDAY...ALMOST ALL AREAS WILL FAIL TO CRACK THE FREEZING MARK.
ON SUNDAY...HOWEVER...ALMOST ALL LOCATIONS WILL MAKE IT TO AT LEAST
JUST ABOVE FREEZING. HIGHS ON MONDAY WILL RANGE FROM THE MID AND
UPPER 30S IN THE ADIRONDACKS AND GREENS...TO THE UPPER 40S IN THE
MID HUDSON VALLEY. THE COLD FRONT WILL BACK OFF TUESDAY HIGH
TEMPERATURES FROM AROUND 30 DEGREES IN THE ADIRONDACKS...TO THE MID
40S IN THE MID HUDSON VALLEY.
LOW TEMPERATURES BOTH FRIDAY AND SATURDAY NIGHTS WILL RANGE FROM
AROUND ZERO IN THE ADIRONDACKS...TO THE MID TEENS IN THE LOWER MID
HUDSON VALLEY. SUNDAY NIGHT LOWS WILL RANGE FROM THE UPPER TEENS IN
THE ADIRONDACKS...TO THE UPPER 20S IN THE LOWER MID HUDSON VALLEY.
A FURTHER MODERATION WILL TAKE PLACE FOR MONDAY NIGHT.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
A WEAK CLIPPER SYSTEM WILL MOVE ACROSS THE REGION TONIGHT. SOME
LIGHT SNOW IS EXPECTED ACROSS THE ROUTE FROM KALB/KPOU/KGFL/KPSF.
VERY LIGHT ACCUMULATIONS ARE EXPECTED OVERNIGHT. MOST LOCATIONS
WILL GENERALLY SEE LESS THAN HALF AN INCH WITH THE EXCEPTION OF
KPOU WHERE UP TO AN INCH IS POSSIBLE. CEILINGS AND VISIBILITIES
WILL BE REDUCED IN SNOW SHOWERS. THE SNOW SHOWERS WILL END AFTER
1200Z. CEILINGS AND VISIBILITIES WILL IMPROVE TO VFR AFTER 1200Z.
WINDS WILL BE CALM TO LIGHT TROUGH 1200Z WEDNESDAY AM. WINDS WILL
BECOME WESTERLY LATE WEDNESDAY MORNING AND INCREASING TO AROUND
10 KTS DURING THE AFTERNOON.
OUTLOOK...
WED-THU...VFR. NO SIG WX.
THU NGT-FRI NIGHT. MVFR/IFR WITH SNOW LIKELY.
SAT...VFR...NO SIG WX
SUN...VFR...NO SIG WX
&&
.HYDROLOGY...
WIDESPREAD HYDRO PROBLEMS ARE NOT ANTICIPATED OVER THE NEXT FEW
DAYS AS OUR COLD WEATHER CONTINUES WITH ANY PRECIPITATION IN THE
FORM OF SNOW.
SOME RIVER AND STREAM GAGES ARE EXPERIENCING ICE EFFECTS. ICE
WILL CONTINUE TO FORM AND THICKEN ON ALL BODIES OF WATER.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...VTK/BGM
NEAR TERM...VTK/BGM
SHORT TERM...BGM
LONG TERM...ELH
AVIATION...VTK
HYDROLOGY...IAA/BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
652 PM EST TUE FEB 5 2013
.SYNOPSIS...
A CLIPPER SYSTEM WILL APPROACH AND MOVE ACROSS THE REGION
TONIGHT...BRINGING SOME VERY LIGHT SNOW TO THE AREA. FAIR WEATHER
IS EXPECTED MID WEEK AS HIGH PRESSURE BUILDS IN. A WIDESPREAD
SNOWFALL IS ANTICIPATED FOR THE LATER HALF OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 630 PM...LATEST RADAR AND SURFACE OBSERVATIONS ARE
SHOWING SOME LIGHT SNOW SHOWERS ACROSS THE MID HUDSON VALLEY...SOUTHEAST
CATSKILLS AND NW CT. WILL MAKE A MINOR ADJUSTMENT TO INCREASE POPS
AND QPF/SNOWFALL ACROSS THE SOUTHERN PORTION OF THE FORECAST AREA.
OTHERWISE...UPSTREAM RADARS CONTINUE TO SHOW A BAND OF PRECIP
ACROSS SOUTHERN LOWER MICHIGAN AND TRACKING SOUTHEAST TOWARD OHIO.
PREV DISC...
PER THE H2O VAPOR LOOP ANALYSIS...A FAST MOVING SHORT WAVE WAS
CROSSING THE LOWER GREAT LAKES REGION THIS AFTERNOON. REGIONAL
RADARS SHOW A SCT-BKN LINE OF PRECIPITATION THAT WAS ASSOCIATED
WITH WEAK FORCING. THIS FORCING IS EXPECTED TO REMAIN QUASI-
FOCUSED AS IT MIGRATES ACROSS THE CWFA. EXPERIENTIAL FORECAST
REFLECTIVITIES LEAD BY THE HRRR ALL SUGGEST A SCATTERED NATURE TO
THE SNOWFALL TONIGHT. ALONG WITH THE MOS GUIDANCE...WE WILL DROP
BACK POPS TO THE HIGH CHC-SCT CATEGORY WITH ACCUMULATIONS LESS
THAN 1 INCH FOR MOST LOCATIONS. THE CLOUD COVER WILL LIKELY REMAIN
EXTENSIVE OVERNIGHT WHICH SHOULD KEEP TEMPS A LITTLE MILDER THAN
THIS MORNINGS VALUES.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
WEDNESDAY...
MINOR LAKE EFFECT SNOW EVENT WILL BE POSSIBLE FOR PORTIONS OF THE
MOHAWK VALLEY AND ADIRONDACKS IN THE MORNING BEFORE THOSE
INVERSION HEIGHTS COLLAPSE TOWARD NOON. OTHERWISE...VARIABLE CLOUD
COVER WILL BEGIN TO SLOWLY IMPROVE THROUGH THE DAY AS TEMPERATURES
CLIMB INTO THE LOW-MID 30S FOR VALLEY LOCATIONS AND 20S ELSEWHERE.
WINDS WILL BE RATHER GUSTY THROUGH THE DAY AS WE MIX UP TO 30KT
MAGNITUDES. FURTHERMORE...THOSE WINDS MAY GET FUNNELED DOWN THE
MOHAWK RIVER FOR A SLIGHT ENHANCEMENT TO THOSE WESTERLY WINDS
THROUGH THE DAY.
WEDNESDAY NIGHT...
RIDGE OF HIGH PRESSURE WILL CREST OVER THE REGION. THIS WILL ALLOW
FOR...INITIALLY...CLEAR SKIES THROUGH THE EVENING HOURS WHICH WILL
SEND TEMPS QUICKLY DOWNWARD WITH NEAR IDEAL RADIATIONAL COOLING
/CLEAR SKIES AND LIGHT WINDS WITH A FROZEN AND PARTIAL SNOW
COVERED GROUND/. THEN WE WILL WATCH UPSTREAM CONDITIONS CLOSELY AS
STRONG PACIFIC ENERGY COMES ASHORE AND TRACKS ACROSS THE CENTER OF
THE NATION. NCEP MODEL SUITE ALONG WITH INTERNATIONAL GUIDANCE ARE
IN RATHER GOOD AGREEMENT WITH BROAD WARM ADVECTION ALOFT TO
COMMENCE OVERNIGHT WEDNESDAY INTO SUNRISE THURSDAY MORNING.
ISENTROPIC ANALYSIS ON THE 285-290K SURFACE SUPPORTS BROAD
ISENTROPIC LIFT AND SLOWLY LOWERING CPD/S TO RESULT WITH AN
INCREASE OF CLOUD COVER. THESE CLOUDS SHOULD LIMIT FURTHER
DECLINES IN THE TEMPERATURES OVERNIGHT AND MAY EVEN SEE A SLOW
REBOUND TOWARD SUNRISE.
THURSDAY...
THE AFOREMENTIONED ISENTROPIC LIFT CONTINUES THROUGH THE DAY
THURSDAY WITH A CONTINUE DECREASE IN THOSE CPD/S. THIS SHOULD
RESULT IN THE THICKENING AND LOWERING OF THE CLOUD DECK AND THE
CHANCE FOR OVERRUNNING LIGHT SNOW TO DEVELOP. WHILE MODEL QPF
SIGNALS ARE NOT SHOWING THIS ACROSS OUR REGION /THEY DO SO FURTHER
UPSTREAM/...THE COMBINATION OF CONTINUED ISENTROPIC LIFT AND LESS
THAN 30MB CPD/S...WE WILL PLACE CHC POPS ACROSS THE NORTHERN 1/2
OF THE CWFA BEGINNING BY LATE MORNING. THE BEST CHANCE FOR AN
ACCUMULATING SNOWFALL WILL LIKELY REMAIN ALONG AND NORTH OF I90
WHERE THE BEST LIFT AND MOISTURE PROFILES ARE EXPECTED AND VALUES
UP TO 1 INCH POSSIBLE. AS FOR TEMPERATURES...THE LOW LEVEL
AGEOSTROPHIC FLOW DOES INCREASE FROM THE NORTH AND THIS TOO SHOULD
LIMIT TEMPERATURES FROM GETTING OUT OF THE 20S.
THURSDAY NIGHT...
THIS WILL BE THE PERIOD OF TRANSITION TO A POTENTIAL STORM
IMPACTING THE REGION. GLOBAL MODEL TRENDS AND THE PERSISTENT ECMWF
FOR THE PAST 5 RUNS WANT TO PHASE THE NORTHERN STREAM PACIFIC
ENERGY WITH SOUTHERN STREAM WAVE/S/ ACROSS BAJA AND NORTHERN
MEXICO. LOW LEVEL SOUTHERLY JET AND MOISTURE TRANSPORT VECTORS
INCREASE RATHER RAPIDLY THURSDAY NIGHT WHERE THE CHANCE FOR LIGHT
SNOW TO INCREASE ACROSS THE REGION. GIVEN THE FORECAST WIND
TRAJECTORY AND MAGNITUDES...WE WILL FAVOR THE HIGHER TERRAIN WITH
LIKELY POPS AND HIGH CHANCE FOR THE VALLEY LOCATIONS. AS FOR
NOW...SNOWFALL AMOUNTS OF 1-2 INCHES WITH THE POSSIBILITY OF SOME
HIGHER TOTALS IN THE MOUNTAINS. GUIDANCE NUMBERS ARE FAIRLY CLOSE
AS WE LEANED MORE TOWARD THE GFS/ECMWF MOS NUMBERS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
HPC GUIDANCE. MOST MODELS NOW ON BOARD WITH A MAJOR WINTER EVENT
FOR THE END OF THE WEEK. LOW PRESSURE WILL BE NEAR VIRGINIA BEACH
AT THE START OF THE PERIOD...WITH SNOW ALREADY OVERSPREADING OUR
FORECAST AREA. THE LOW WILL TRACK TO SOUTH OF WESTERN NOVA SCOTIA
BY SATURDAY MORNING...INTENSIFYING RAPIDLY. A PERIOD OF RAIN OR A
SNOW MIX IS A POSSIBILITY BRIEFLY DURING THE DAY ON FRIDAY IN THE
LOWER SECTION OF THE MID HUDSON VALLEY...BUT FOR NOW WILL SAY IT IS
ALL SNOW. OTHERWISE...AN ALL-SNOW EVENT IS ANTICIPATED WITH
CONFIDENCE...WITH ACTIVITY WINDING DOWN SWIFTLY DURING THE DAY ON
FRIDAY. A FLOW TURNING NORTHERLY ENHANCED BY STRONG HIGH PRESSURE
MOVING IN BY SUNDAY ENSURES THAT WE HAVE AN ALL-SNOW EVENT BEYOND
FRIDAY AFTERNOON.
AS IT LOOKS RIGHT NOW...THE LOW IS EXPECTED TO STAY WELL ENOUGH TO
THE SOUTH...SUCH THAT 6 TO 10 INCHES OF TOTAL SNOW ACCUMULATION
LOOKS MOST REASONABLE...WITH THE GREATER AMOUNTS...OF COURSE...TO
THE SOUTH AND EAST IN OUR FORECAST AREA. MORE IS POSSIBLE...BUT SO
IS LESS...DEPENDING ON HOW THE SYSTEM EVOLVES. THIS LOOKS TO BE A
BROAD-AREA SNOW-PRODUCER.
BY SATURDAY NIGHT...SKIES WILL BE MOSTLY ON THE PARTLY CLOUDY
SIDE...WITH WINDS RAPIDLY DIMINISHING TO MAKE THE NIGHT A COLD ONE.
BUT THE REPRIEVE WILL BE BRIEF AS ANOTHER SYSTEM THREATENS THE
REGION WITH A WINTRY MIX OF PRECIPITATION FOR MONDAY/MONDAY NIGHT.
A COLD FRONT SLIDES THROUGH THE REGION...WITH TUESDAY BEGINNING A
PERIOD OF LAKE EFFECT SNOW SHOWERS...MAINLY WEST OF THE CAPITAL
REGION.
HIGH TEMPERATURES WILL RANGE FROM THE MID 20S IN THE ADIRONDACKS AND
GREENS...TO THE UPPER 30S IN THE LOWER MID HUDSON VALLEY. ON
SATURDAY...ALMOST ALL AREAS WILL FAIL TO CRACK THE FREEZING MARK.
ON SUNDAY...HOWEVER...ALMOST ALL LOCATIONS WILL MAKE IT TO AT LEAST
JUST ABOVE FREEZING. HIGHS ON MONDAY WILL RANGE FROM THE MID AND
UPPER 30S IN THE ADIRONDACKS AND GREENS...TO THE UPPER 40S IN THE
MID HUDSON VALLEY. THE COLD FRONT WILL BACK OFF TUESDAY HIGH
TEMPERATURES FROM AROUND 30 DEGREES IN THE ADIRONDACKS...TO THE MID
40S IN THE MID HUDSON VALLEY.
LOW TEMPERATURES BOTH FRIDAY AND SATURDAY NIGHTS WILL RANGE FROM
AROUND ZERO IN THE ADIRONDACKS...TO THE MID TEENS IN THE LOWER MID
HUDSON VALLEY. SUNDAY NIGHT LOWS WILL RANGE FROM THE UPPER TEENS IN
THE ADIRONDACKS...TO THE UPPER 20S IN THE LOWER MID HUDSON VALLEY.
A FURTHER MODERATION WILL TAKE PLACE FOR MONDAY NIGHT.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
A WEAK CLIPPER SYSTEM WILL MOVE ACROSS THE REGION TONIGHT. SOME
LIGHT SNOW IS EXPECTED ACROSS THE ROUTE FROM KALB/KPOU/KGFL/KPSF.
VERY LIGHT ACCUMULATIONS ARE EXPECTED OVERNIGHT. MOST LOCATIONS
WILL GENERALLY SEE LESS THAN HALF AN INCH WITH THE EXCEPTION OF
KPOU WHERE UP TO AN INCH IS POSSIBLE. CEILINGS AND VISIBILITIES
WILL BE REDUCED IN SNOW SHOWERS. IFR IS POSSIBLE IN MORE MODERATE SNOW
SHOWERS. THE SNOW SHOWERS WILL END AFTER 1200Z. CEILINGS AND
VISIBILITIES WILL IMPROVE TO VFR AFTER 1200Z.
WINDS WILL BE CALM TO LIGHT TROUGH 1200Z WEDNESDAY AM. WINDS WILL
BECOME WESTERLY LATE WEDNESDAY MORNING AND INCREASING TO AROUND
10 KTS DURING THE AFTERNOON.
OUTLOOK...
WED-THU...VFR. NO SIG WX.
THU NGT-FRI NIGHT. MVFR/IFR WITH SNOW LIKELY.
SAT...VFR...NO SIG WX
SUN...VFR...NO SIG WX
&&
.HYDROLOGY...
WIDESPREAD HYDRO PROBLEMS ARE NOT ANTICIPATED OVER THE NEXT FEW
DAYS AS OUR COLD WEATHER CONTINUES WITH ANY PRECIPITATION IN THE
FORM OF SNOW.
SOME RIVER AND STREAM GAGES ARE EXPERIENCING ICE EFFECTS. ICE
WILL CONTINUE TO FORM AND THICKEN ON ALL BODIES OF WATER.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...VTK/BGM
NEAR TERM...VTK/BGM
SHORT TERM...BGM
LONG TERM...ELH
AVIATION...VTK
HYDROLOGY...IAA/BGM
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
646 PM EST TUE FEB 5 2013
.SYNOPSIS...
A WEAK COLD FRONT WILL PASS THROUGH THE REGION LATE TONIGHT. HIGH
PRESSURE WILL THEN BUILD WEDNESDAY AND WEDNESDAY NIGHT. A WARM
FRONT WILL LIFT NORTH EARLY THURSDAY...BEFORE A GULF LOW PRESSURE
SYSTEM MOVES THROUGH THURSDAY NIGHT AND OFFSHORE BY FRIDAY
AFTERNOON. HIGH PRESSURE WILL BUILD AGAIN FOR THE WEEKEND INTO
EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
NO MAJOR CHANGES WERE MADE WITH THE EARLY EVENING UPDATE. CLOUD
COVER APPROACHING FROM THE SOUTHWEST IS ASSOCIATED WITH MODEST
ISENTROPIC ASSENT ALONG THE 295K SURFACE. THE 05/21Z RAP IS
HANDING SKY TRENDS THE BEST AND WAS USED TO CONSTRUCT SKY COVER
THROUGH SUNRISE. GENERALLY EXPECT MOSTLY CLOUDY SKIES TO
OVERSPREAD THE ENTIRE FORECAST AREA THIS EVENING WITH SOME
CLEARING POSSIBLE ACROSS THE NORTHWEST ZONES CLOSER TO SUNRISE AS
A COLD FRONT DROPS IN FROM THE NORTHWEST. SHOWER ACTIVITY NOTED
ON THE KTLH/KVAX RADARS CORRESPONDS WITH THE STRONGEST 295K
LIFT AND LOWEST CONDENSATION PRESSURE DEFICITS...WHICH IS
FORECAST TO BRUSH THE FAR SOUTHERN ZONES ALONG THE ALTAMAHA RIVER
LATER THIS EVENING. WILL MAINTAIN A SLIGHT CHANCE FOR SHOWERS OVER
THIS AREA WITH DRY CONDITIONS ELSEWHERE. LOWS WILL RANGE FROM THE
LOWER-MID 40S INLAND WITH UPPER 40S-LOWER 50S AT THE COAST.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY WILL BE FAIRLY UNEVENTFUL AFTER THE WEAK COLD FRONT PASSES
AROUND 12Z AND THE CONTINENTAL POLAR AIR MASS SETTLES IN. SKIES WILL
BE MOSTLY CLEAR AND WINDS WILL BE LIGHT AND FROM THE NORTH. EXPECT
TEMPS TO BE SIMILAR TO TODAY...PEAKING IN THE UPPER 60S WITH LOW
70S IN SE GA.
WEDNESDAY NIGHT THE MEDIUM RANGE GUIDANCE HAS COME INTO PRETTY GOOD
AGREEMENT THAT A BROAD UPPER TROUGH WILL TAKE SHAPE TO OUR WEST WITH
SOME SHORTWAVE ENERGY LIFTING NORTHEAST THROUGH THE AREA ON
THURSDAY. WITH THE ZONAL FLOW...THIS ENERGY WILL MOVE THROUGH
QUICKLY AND NOT HAVE MUCH OF AN AFFECT ON US...BUT MIN TEMPS WILL BE
A LITTLE WARMER OVER SE GA WITH THE INCREASING CLOUD COVER WITH MID
40S OVER SC.
ON THURSDAY THE BEST ISENTROPIC ASCENT WILL LIFT NORTH WITH THE WARM
FRONT. THE CWA WILL BE UNDER THE NOSE OF A 110 KT JET STREAK AND
WITH THE ISENTROPIC LIFT...EXPECT AN INCREASE IN CLOUD COVER AND
ONSHORE WIND SPEEDS AS THE GRADIENT TIGHTENS. WE ARE STILL FAVORING
THE ECMWF SURFACE LOW TRACK WHICH LIFTS THE LOW OUT OF THE GULF AND
INTO CENTRAL GA BY NIGHTFALL THURSDAY. THE PROBABILITY OF OUR ENTIRE
FORECAST AREA AT LEAST RECEIVING ONE-HUNDREDTH OF AN INCH IS QUITE
HIGH GIVEN THE CURRENT PROGS. WE OPTED TO ADD LIKELY POPS FOR THE
ENTIRE CWA THURSDAY NIGHT INTO FRIDAY MORNING. RULED OUT THUNDER
BASED ON THE TIME OF DAY AND LACK OF THERMODYNAMICS. LOW TEMPS
SHOULD REMAIN ABOVE 50 WITH THE CLOUD COVER AND SOUTHERLY FLOW.
PRECIP SHOULD END RATHER ABRUPTLY FRIDAY MORNING AS THE SYSTEM PULLS
AWAY FROM THE AREA AND THE COLD FRONT PASSES. WINDS LOOK TO STEADILY
SHIFT FROM SSW TO WNW. WE ONLY SHOW SLIGHT CHANCE POPS FRIDAY
MORNING...THEN ONLY A FEW SHOWERS OVER THE WATERS IN THE AFTERNOON.
A MODIFIED CANADIAN AIR MASS WILL SLOWLY FILTER IN ON FRIDAY BUT
HIGHS SHOULD STILL RISE INTO THE 60S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE UPPER TROUGH WILL SHIFT EAST FRIDAY NIGHT WITH BROAD UPPER LEVEL
RIDGING SATURDAY THROUGH EARLY NEXT WEEK. WEAK CANADIAN HIGH
PRESSURE ON SATURDAY WILL DISSIPATE WHILE SHIFTING EAST INTO THE
WESTERN ATLANTIC SATURDAY NIGHT AND SUNDAY. WE EXPECT A WARMING
TREND WITH RELATIVELY DRY WEATHER. ANOTHER FRONT COULD APPROACH FROM
THE WEST NEXT TUESDAY.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
VFR. SHOWER ACTIVITY MOVING ACROSS SOUTHERN GEORGIA AND NORTHERN
FLORIDA WILL REMAIN TO THE SOUTH OF KCHS/KSAV. THERE ARE SMALL
PROBABILITIES FOR SOME SHALLOW GROUND FOG TO FORM AT KSAV JUST
BEFORE SUNRISE. INCLUDED A TEMPO FROM 10-12Z FOR 5SM BR TO COVER
FOR NOW. OTHERWISE...WINDS WILL SHIFT NORTH BEHIND A COLD FRONT
THURSDAY MORNING WITH SKIES CLEARING.
EXTENDED AVIATION OUTLOOK...CEILING AND VISIBILITY RESTRICTIONS
WILL BECOME INCREASINGLY LIKELY THURSDAY INTO THURSDAY NIGHT AS
LOW PRESSURE MOVES THROUGH THE REGION. LOW CEILINGS COULD LINGER
INTO FRIDAY BEFORE VFR CONDITIONS RETURN LATE IN THE PERIOD.
&&
.MARINE...
TONIGHT...LIGHT TO MODERATE SOUTHWEST FLOW WILL CONTINUE INTO THE
OVERNIGHT PERIOD...AS THE MARINE ZONES BECOME LOCATED BETWEEN A
DESCENDING FRONT FROM THE NORTH AND RETREATING HIGH PRESSURE IN
THE ATLANTIC. WIND SPEEDS WILL GENERALLY BE 15 KT OR
LESS...ALTHOUGH AN OCCASIONAL GUST TO 20 KT IS POSSIBLE IN THE
NORTHERN-MOST WATERS. EXPECT A GRADUAL VEERING TO MORE OFFSHORE
FLOW BY DAYBREAK WEDNESDAY. SEAS WILL RANGE FROM 1 TO 3 FT.
WEDNESDAY THROUGH SUNDAY...RELATIVELY WEAK WINDS EXPECTED WEDNESDAY
THROUGH THURSDAY MORNING AS HIGH PRESSURE WEAKENS AND LOW PRESSURE
TAKES SHAPE ALONG THE NORTHERN GULF COAST. SOUTHERLY WINDS WILL
STEADILY INCREASE THROUGHOUT THE DAY ON THURSDAY...THEN
DRASTICALLY THURSDAY EVENING AS THE LOW MOVES NORTHEAST INTO
CENTRAL GA AND TOWARD CENTRAL SC. WINDS OR SEAS MAY BRIEFLY REACH
SMALL CRAFT ADVISORY CRITERIA THURSDAY NIGHT BEFORE WEAKENING ON
FRIDAY WITH WIND SPEEDS NEAR 25 KT AND SEAS OF 6 FEET. A BRIEF
NORTHEAST SURGE WILL OCCUR ON SATURDAY AS COOL HIGH PRESSURE
BUILDS FROM THE NORTH. WE MAY AGAIN APPROACH ADVISORY CRITERIA
DURING THIS TIME ALBEIT BRIEFLY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS LINCOLN IL
311 PM CST MON FEB 4 2013
.DISCUSSION...
ISSUED 300 PM CST MON FEB 4 2013
THE ISSUES THIS FORECAST WILL BE A TUESDAY CLIPPER...A COLD FRONT
THURSDAY...A WARMING TREND FOR THE WEEKEND...THEN A SPRING-LIKE
STORM SYSTEM LIFTING THROUGH NW IL LATER ON SUNDAY AND SUNDAY
NIGHT. NO MAJOR MODEL DIFFERENCES THROUGH THE WEEK...EVEN THROUGH
THE SUNDAY SYSTEM. WILL USE A BLEND AND KEEP RELATIVE CONSISTENCY
WITH THIS UPDATE.
SHORT TERM...TONIGHT THROUGH WEDNESDAY.
THE CLEARING ACROSS CENTRAL IL APPEARS TO BE SHORT LIVED AS
SATELLITE IMAGES SHOW A BAND OF LOW STRATO-CU ADVANCING EAST OF
THE IL RIVER AS OF 230PM. WE CAN SEE THE GROUND THROUGH THE
CLOUDS...INDICATING THE MOISTURE LAYER IS RATHER THIN...BUT
A SUBSIDENCE INVERSION ASSOCIATED ADVANCING HIGH PRESSURE MAY BE
ENOUGH TO TRAP THAT MOISTURE TONIGHT ALLOWING FOR STRATUS
REDEVELOPMENT. WILL KEEP TONIGHT/S SKY FORECAST ON THE PESSIMISTIC
SIDE.
THE NEXT CLIPPER SYSTEM WILL PASS NORTH OF IL ON TUESDAY...WITH
THE PRIMARY INFLUENCE FOR ANY OF OUR COUNTIES BEING FLURRIES
ACROSS THE NORTH FROM GALESBURG TO CHAMPAIGN. NO ACCUMULATION WILL
REACH THIS FAR SOUTH AS THE PRIMARY ISENTROPIC LIFT AND MOISTURE
CONVERGENCE WILL BE IN N IL AND WIS. WE WILL SEE GUSTY W-SW WINDS
DEVELOP TOWARD MID-DAY AHEAD OF THE SURFACE TROUGH...MAKING HIGHS
IN THE MID 30S TO LOW 40S FEEL A LITTLE COLDER.
LITTLE CHANGE IN AIRMASS IS EXPECTED FOR TUE NIGHT AND WED AS
ZONAL FLOW BEGINS TO DEVELOP ALOFT. RISING HEIGHTS ALOFT ACROSS
THE EASTERN PLAINS WILL ALSO WORK TO SET THE STAGE FOR A GENERAL
WARMING TREND FOR LATE WEEK AND THE WEEKEND. DRY CONDITIONS WILL
BE SEEN TUES NIGHT THROUGH WED NIGHT UNDER RELATIVELY WEAK HIGH
PRESSURE.
LONG TERM...THURSDAY THROUGH MONDAY.
A LOW PRESSURE SYSTEM WILL TRACK FROM THE NORTHERN PLAINS AND INTO
THE WESTERN GREAT LAKES ON THURSDAY...DRAGGING A WEAKENING COLD
FRONT ACROSS ILLINOIS. A SOUTHERN STREAM LOW PRESSURE EXTENSION OF
THAT FRONT WILL BECOME THE DOMINANT FEATURE AS THE COLD FRONT
PASSES...POSSIBLY DIMINISHING OUR RAINFALL CHANCES LATE WED NIGHT
THROUGH THURS NIGHT.
HOWEVER...PRECIP TYPE MAY BE A CONCERN LATE WED NIGHT AND THURS
MORNING. FREEZING RAIN MAY PRODUCE SOME LIGHT ICING ACROSS OUR FAR
NORTH DURING THAT TIME. THE SURFACE MAY REMAIN JUST BELOW FREEZING
IN THE NORTH AS MID LEVELS UNDERGO SIGNIFICANT WARMING WITH
INCREASING MOISTURE. FORECAST SOUNDINGS SHOW THE WET BULB BELOW
FREEZING FOR THE LOWEST 100 MB...WHICH MAY BE ENOUGH TO KEEP THE
GROUND TEMPS BELOW FREEZING DESPITE WEAK WARM ADVECTION EVEN AT
THE SURFACE. ANY ICING WOULD BE VERY LIGHT...AND MAINLY NORTH OF A
LINE FROM GALESBURG TO CHILLICOTHE.
BEFORE THE PRECIP ARRIVES WED NIGHT...WE EXPECT STEADY OF SLOWLY
RISING TEMPS IN OUR WESTERN AREAS...BUT POSSIBLY SOME COOLING
STILL IN OUR EASTERN AREAS WHERE SKIES MAY REMAIN CLEAR LONGER
INTO THE NIGHT. AS PRECIP EXPANDS EASTWARD THURSDAY MORNING...OUR
NORTHEAST MAY SEE SOME OF THAT FREEZING RAIN...MAINLY NORTH OF
I-74. THE COMPLICATED FORECAST FOR SURFACE TEMPERATURE MAKES IT
DIFFICULT TO DISCERN HOW MUCH FREEZING RAIN WILL DEVELOP...IF
ANY...BUT WE WILL CONTINUE TO KEEP A MENTION FOR WED NIGHT AND
THURS MORNING ACROSS THE NORTH FOR NOW.
DRY CONDITIONS SHOULD RETURN FOR THURSDAY NIGHT THROUGH SATURDAY
AS HIGH PRESSURE PASSES ACROSS THE AREA.
SOUTHERLY FLOW AND WARMING WILL BECOME MORE PROMINENT ON SATURDAY
AS THE NEXT SYSTEM APPROACHES ACROSS THE PLAINS. RAIN IS EXPECTED
TO REACH OUR WESTERN COUNTIES ON SATURDAY NIGHT...BEFORE A SURFACE
LOW LIFTS NORTHEAST ACROSS FAR NW IL LATER ON SUNDAY. SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP ON SUNDAY AS THE LOW PASSES
BY...AND THE COLD FRONT MOVES ACROSS ILLINOIS. SEVERE STORM
POTENTIAL LOOKS MARGINAL THIS FAR NORTH RIGHT NOW...BUT
INSTABILITY PARAMS DEFINITELY SUPPORT SOME THUNDERSTORMS. HIGHS ON
SUNDAY WILL BE THE WARMEST OF THE NEXT WEEK...WITH UPPER 40S TO
AROUND 50...AND SURFACE DEWPOINTS INTO THE 40S.
THE ARRIVAL OF COLDER AIR BEHIND THIS SYSTEM WILL MOST LIKELY NOT
ARRIVE UNTIL THE DRY AIR INTRUSION SHUTS DOWN THE PRECIP. SO WE DO
NOT EXPECT ANY SNOW IN OUR AREA BEHIND THIS LOW. IF THE TRACK OF
THE SURFACE LOW SHIFTS EAST...THAT MAY CHANGE. FOR NOW...WE EXPECT
ALL RAIN FROM THE SAT NIGHT-SUN NIGHT SYSTEM.
DRY CAN COOLER CONDITIONS ARE FORECAST FOR MONDAY WITH CLEARING
SKIES DURING THE AFTERNOON.
SHIMON
&&
.AVIATION...
ISSUED 1135 AM CST MON FEB 4 2013
1010 MB LOW PRESSURE OVER WEST CENTRAL IL HAS SW WINDS 10-15 KTS
AHEAD OF IT EAST OF THE IL RIVER AND WINDS TURN NNW BEHIND ITS
FRONT BY PIA/IL RIVER. LOW PRESSURE TO WEAKEN AS IT TRACKS ESE
THROUGH CENTRAL IL THIS AFTERNOON AND INTO THE CENTRAL OHIO VALLEY
BY SUNSET. SW WINDS EAST OF THE IL RIVER TO SHIFT NNW DURING THE
NEXT 1-3 HOURS...SHIFTING LAST AT CMI AND DEC. VFR CONDITIONS MUCH
OF THIS AFTERNOON OVER CENTRAL IL WITH SCATTERED-BROKEN MID/HIGH
CLOUDS. HRRR MODEL DEPICTS MVFR CLOUDS OVER IA AND NORTHERN IL
WELL AND USED THIS MODEL TO BRING THESE CLOUDS GRADUALLY SOUTHWARD
TO PIA AROUND 2030Z...BMI AROUND 22Z AND NEAR I-72 AROUND 00Z.
HRRR MODELS SHOWS THESE LOW CLOUDS LINGERING OVER CENTRAL IL
THIS EVENING. NAM LOW LEVEL RH FIELDS SHOWS THESE LOW CLOUDS
DECREASING FROM NW TO SE LATE TONIGHT AND TUE MORNING. A LIGHT FOG
WITH 4-6 MILES VSBYS POSSIBLE LATER TONIGHT INTO MID MORNING TUE.
WINDS BECOME LIGHT OVERNIGHT AND TURN BACK TO THE SW 10-15 KTS
DURING TUE MORNING. 1001 MB LOW PRESSURE OVER EAST-CENTRAL ALBERTA
TO DIVE SE INTO NW LOWER MI BY 18Z/NOON TUE KEEPING IT LIGHT SNOW
AND LOW CLOUDS MAINLY NORTH OF I-74 TUE.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
156 PM CST MON FEB 4 2013
.DISCUSSION...
1230 PM CST
HAVE OPTED TO EXTEND THE ADVISORY FOR LAKE AND COOK COUNTIES IN
NORTHEAST IL DUE TO LAKE INDUCED SNOW BAND MOVING TOWARD SHORE
EARLY THIS AFTERNOON.
THE MAIN SYNOPTIC EVENT THAT BROUGHT TWO TO FOUR INCHES OF SNOW
EARLIER THIS MORNING HAS EXITED...BUT WITH ITS DEPARTURE AND
NORTHEAST FLOW HAS DEVELOPED LAKE EFFECT SNOW. A PRONOUNCED BAND
FIRST SEEN ON VISIBLE SATELLITE NOW IS BECOMING BETTER DEFINED ON
THE TMKE RADAR. REFLECTIVITY HAS BEEN AS HIGH AS 30 DBZ AT TIMES
WITH THIS INDICATING LIKELY GOOD BURSTS OF SNOW. THE CONVERGENCE
SEEN ON SATELLITE AND RADAR LINES UP WELL WITH RAP AND NAM
DEPICTING IN THE LOWER LEVELS AND THE TREND HAS BEEN TO SLOW THIS
REORIENTING EASTWARD TOWARD NORTHWEST IN. THUS A FEW HOURS OF
SNOWFALL THIS AFTERNOON ARE FAVORED INTO EASTERN LAKE AND COOK
COUNTIES. EQUILIBRIUM LEVELS ARE SOMEWHAT LOW BEING AROUND
5000-6000 FT AND WIND SHEAR IN THE CLOUD DEPTH IS ALSO A LITTLE
HIGH /GREATER THAN 30 KT/...WHICH TOGETHER WILL LIKELY LIMIT
HEAVIER RATES FROM BEING WIDESPREAD OR TO MAKE IT FAR INLAND.
OTHER FACTORS SUCH AS THE CONVERGENCE...MOISTURE...AND INSTABILITY
ARE CONDUCIVE THOUGH FOR THE SNOW TO AT LEAST MAKE IT ONSHORE. SO
UNCERTAINTIES ON INTENSITY WOULD NORMALLY MEAN HOLDING OFF A
HEADLINE...HOWEVER THE WINTER WEATHER ADVISORY HAD BEEN ALLOWED TO
GO TO NOON ORIGINALLY FOR THE THREAT OF AT LEAST TEMPORARY
HEAVIER RATES AND BRINGING ADDITIONAL SNOWFALL TO WHAT HAS FALLEN.
WITH THE BAND/AREA OF SHOWERS OF SNOW MOVING INTO FAR NORTHEAST
ILLINOIS SHORTLY...SEE IT AS MORE PRUDENT TO CONTINUE ADVISORY.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* NORTH WINDS BECOMING NORTH-NORTHWEST BY 22Z.
* LAKE-ENHANCED SNOW IN THE METROPOLITAN AREA WILL GET CLOSE TO
ORD AND MDW. AT THIS TIME APPEARS THE HEAVIER SNOW WITH LOWER
VISIBILITIES WILL STAY JUST EAST OF THE FIELDS.
PAW
//DISCUSSION...UPDATED 18Z...
LOW PRESSURE CENTER IN CENTRAL IL WILL MOVE EAST THIS AFTERNOON.
THIS WILL ALLOW WINDS TO SHIFT MORE TO THE NORTHEAST AND THEN
NORTH-NORTHWEST DURING THE AFTERNOON. THE EASTERLY WINDS FROM
THIS MORNING ARE SUPPORTING SOME BANDS OF LAKE-ENHANCED SNOW OVER
THE CHICAGO METROPOLITAN AREA AT MIDDAY. AS WINDS SHIFT AROUND
THESE AREAS WILL MOVE CLOSER TO THE LAKE AND THEN INTO NORTHWEST
INDIANA. AT THIS TIME IT APPEARS THAT ONLY GYY WOULD BE VULNERABLE
TO SEEING SOME OF THIS SNOW AND EVEN THERE CONFIDENCE IS LOW.
ANOTHER IN THE SERIES OF CLIPPER SYSTEMS WILL BE MOVING ACROSS THE
TERMINALS ON TUESDAY. THIS ONE WILL BE FURTHER NORTH AND SO THE
THE TERMINALS SHOULD BE ON THE FRINGE OF THE SNOW AREAS THIS TIME.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN WIND TREND.
* MEDIUM CONFIDENCE IN LAKE-ENHANCED SNOW DETAILS.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR PSBL MVFR WITH LIGHT SNOW.
WEDNESDAY...VFR.
THURSDAY...PSBL MVFR WITH LIGHT RAIN/SNOW.
FRIDAY...VFR.
SATURDAY...VFR. PSBL MVFR WITH RAIN IN THE AFTN.
SUNDAY...MVFR. CHANCE OF RAIN.
BEACHLER
&&
.MARINE...
257 AM CST
ANOTHER AREA OF LOW PRESSURE WAS SLIDING EAST ACROSS IOWA INTO THE
OHIO VALLEY TODAY...WHICH WILL ALLOW A SLIGHT INCREASE IN THE WIND
GRADIENT FOR THE SOUTHERN HALF OF LAKE MICHIGAN. HIGH PRESSURE
WILL THEN QUICKLY BUILD IN FROM THE WEST AND PROVIDE RELATIVELY
QUIET WEATHER FOR LAKE MICHIGAN...BEFORE YET ANOTHER LOW PRESSURE
SLIDES INTO THE UPPER MIDWEST LATE TONIGHT/EARLY TUESDAY AND
ARRIVES ACROSS THE WESTERN GREAT LAKES TUESDAY AFTERNOON/EVENING.
THE GRADIENT DOES APPEAR TO INCREASE PRIOR AND JUST AFTER THIS
SYSTEM...THEN ANOTHER RIDGE OF HIGH PRESSURE IS FORECAST TO PUSH
INTO THE WESTERN GREAT LAKES REGION FOR WEDNESDAY. THIS RIDGE OF
HIGH PRESSURE WILL THEN SLIDE EAST TO THE EASTERN OHIO VALLEY
WEDNESDAY NIGHT...WITH AN INCREASING GRADIENT AND SOUTHERLY FLOW
FOR EARLY THURSDAY ACROSS LAKE MICHIGAN. THE GRADIENT THEN
INCREASES FURTHER ACROSS THE FAR NORTHERN PORTION OF THE LAKE
MIDDAY THURSDAY AS A WEAK LOW PRESSURE SLIDES OVER THE SOUTHERN
PORTION OF THE LAKE.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ006-ILZ014 UNTIL 4 PM MONDAY.
IN...WINTER WEATHER ADVISORY...INZ001-INZ002 UNTIL 6 PM MONDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
1231 PM CST MON FEB 4 2013
.DISCUSSION...
1230 PM CST
HAVE OPTED TO EXTEND THE ADVISORY FOR LAKE AND COOK COUNTIES IN
NORTHEAST IL DUE TO LAKE INDUCED SNOW BAND MOVING TOWARD SHORE
EARLY THIS AFTERNOON.
THE MAIN SYNOPTIC EVENT THAT BROUGHT TWO TO FOUR INCHES OF SNOW
EARLIER THIS MORNING HAS EXITED...BUT WITH ITS DEPARTURE AND
NORTHEAST FLOW HAS DEVELOPED LAKE EFFECT SNOW. A PRONOUNCED BAND
FIRST SEEN ON VISIBLE SATELLITE NOW IS BECOMING BETTER DEFINED ON
THE TMKE RADAR. REFLECTIVITY HAS BEEN AS HIGH AS 30 DBZ AT TIMES
WITH THIS INDICATING LIKELY GOOD BURSTS OF SNOW. THE CONVERGENCE
SEEN ON SATELLITE AND RADAR LINES UP WELL WITH RAP AND NAM
DEPICTING IN THE LOWER LEVELS AND THE TREND HAS BEEN TO SLOW THIS
REORIENTING EASTWARD TOWARD NORTHWEST IN. THUS A FEW HOURS OF
SNOWFALL THIS AFTERNOON ARE FAVORED INTO EASTERN LAKE AND COOK
COUNTIES. EQUILIBRIUM LEVELS ARE SOMEWHAT LOW BEING AROUND
5000-6000 FT AND WIND SHEAR IN THE CLOUD DEPTH IS ALSO A LITTLE
HIGH /GREATER THAN 30 KT/...WHICH TOGETHER WILL LIKELY LIMIT
HEAVIER RATES FROM BEING WIDESPREAD OR TO MAKE IT FAR INLAND.
OTHER FACTORS SUCH AS THE CONVERGENCE...MOISTURE...AND INSTABILITY
ARE CONDUCIVE THOUGH FOR THE SNOW TO AT LEAST MAKE IT ONSHORE. SO
UNCERTAINTIES ON INTENSITY WOULD NORMALLY MEAN HOLDING OFF A
HEADLINE...HOWEVER THE WINTER WEATHER ADVISORY HAD BEEN ALLOWED TO
GO TO NOON ORIGINALLY FOR THE THREAT OF AT LEAST TEMPORARY
HEAVIER RATES AND BRINGING ADDITIONAL SNOWFALL TO WHAT HAS FALLEN.
WITH THE BAND/AREA OF SHOWERS OF SNOW MOVING INTO FAR NORTHEAST
ILLINOIS SHORTLY...SEE IT AS MORE PRUDENT TO CONTINUE ADVISORY.
MTF
&&
//PREV DISCUSSION...
419 AM CST
MAIN CONCERN FOR THE NEXT FEW DAYS WILL BE THE CONTINUED PERIODIC
CHANCES FOR SNOW.
BEGINNING TO FEEL LIKE A BROKEN RECORD...REMEMBER RECORDS?...TALKING
ABOUT CLIPPERS BRINGING LIGHT SNOW TO NORTHERN ILLINOIS AND
NORTHWESTERN INDIANA...BUT THE MAIN CONCERN FOR THE REMAINDER OF THE
NIGHT AND INTO THE MORNING HOURS WILL BE THE ONGOING SNOW FALLING
OVER PORTIONS OF THE AREA. WHILE THE LOT RADAR IS STILL READING TOO
HIGH DUE TO MECHANICAL ISSUES...IT DOES INDICATE AN AREA OF SNOW
FALLING NORTH OF A LINE ROUGHLY FROM DIXON...TO JOLIET...TO
VALPARAISO. THIS SNOW IS ASSOCIATED WITH A MID LEVEL VORT MAX
TRACKING THROUGH THE AREA. WHILE LIGHT...TO OCCASIONALLY MODERATE
SNOW HAS BEEN FALLING SINCE EARLY LAST EVENING...THERE IS A VERY
SHARP CUTOFF TO THE SNOW WITH LITTLE OR NO SNOW FALLING SOUTH OF THE
AFOREMENTIONED LINE. EXPECT THIS TREND TO CONTINUE ACROSS THE AREA
THROUGH THE REMAINDER OF THE NIGHT AND INTO THE MORNING HOURS...BUT
AS THE MID LEVEL IMPULSE AND THE ASSOCIATED WEAK SFC LOW BEGIN TO
MOVE EAST OF THE AREA...SOME LIGHT SNOW SHOULD BEGIN TO SPREAD
SOUTHWARD...PERHAPS JUST SOUTH OF THE ILLINOIS AND KANKAKEE RIVERS.
HAVE RECEIVED ONLY A FEW SNOWFALL REPORTS THIS MORNING...BUT WHAT
OBSERVATIONS HAVE BEEN RECEIVED INDICATE THAT 2 TO 3 INCHES HAVE
FALLEN OVER NORTH-CENTRAL ILLINOIS...WHERE THE SNOW HAS BEEN FALLING
THE LONGEST...WITH LESSER AMOUNTS TO THE EAST. WITH ACCUMULATING
SNOW EXPECTED TO CONTINUE OVER MUCH OF THE AREA UNTIL UNTIL LATE
MORNING BEFORE TAPERING OFF TO FLURRIES BY EARLY AFTERNOON...THE
MORNING RUSH HOURS FOR TRAVELERS WILL BE HAZARDOUS...ESPECIALLY ON
UNTREATED OR UNPLOWED ROADS. WHEN ALL IS SAID AND DONE FOR THE
SYNOPTIC SNOW...GENERALLY EXPECT TOTALS OF 2 TO 4 INCHES NORTH OF
THE DIXON...TO JOLIET...TO VALPARAISO LINE AND LESSER AMOUNTS TO THE
SOUTH.
BY THIS AFTERNOON...THE FOCUS WILL SHIFT TO LAKE EFFECT SNOW
POTENTIAL FOR NORTHWESTERN INDIANA. SOME OF THE HIGH RESOLUTION
MODEL GUIDANCE INDICATES THE POTENTIAL FOR A MESO-VORTEX TO FORM
OVER THE SOUTHERN LAKE MICHIGAN WITH A CONVERGENCE ZONE EXTENDING
NORTHWARD. HAVE GENERALLY FOLLOWED THIS IDEA AND BACKED OFF ON THE
LAKE EFFECT SNOW POTENTIAL FOR FAR NERN ILLINOIS AND CONCENTRATED
THE LAKE EFFECT SNOW FORECAST OVER NWRN INDIANA...SINCE THE
MESO-VORTEX WOULD SHIFT WINDS INVOF THE ILLINOIS SHORE OF LAKE
MICHIGAN TO AN OFF-SHORE DIRECTION. GIVEN THE HIGHLY LOCALIZED
NATURE OF LAKE EFFECT SNOW ASSOCIATED WITH THESE TYPES OF
FEATURES...HAVE SOMEWHAT BROAD BRUSHED THE LAKE EFFECT
POTENTIAL...WITH THE POTENTIAL FOR A COUPLE INCHES OF LAKE EFFECT
SNOW AND LOCALLY HIGHER AMOUNTS POSSIBLE.
THE UPPER LEVEL PATTERN IS FINALLY SHOWING INDICATIONS OF DECREASING
AMPLITUDE AS PACIFIC SHORT WAVE ENERGY BEGINS TO BREAK DOWN THE WEST
COAST RIDGE. ALSO...THE EAST COAST TROUGH IS BROADENING AND
FLATTENING. HOWEVER...THE LOCAL AREA IS STILL UNDER FAST NWLY FLOW
ALOFT AND THE NEXT IS THE SERIES OF CLIPPERS IS EXPECTED TO IMPACT
THE REGION ON TUESDAY. THIS SYSTEM IS STILL BEING ADVERTISED TO BE
A BIT LESS FOCUSED AND SHOULD TAKE A MORE NORTHERLY TRACK ACROSS
THE MIDWEST AND GREAT LAKES REGIONS. SO...STILL EXPECT THE HEAVIEST
SNOWFALL AMOUNTS TO BE WELL NORTH OF THE WISCONSIN BORDER. AS FOR
TIMING...EXPECT THE INITIAL SNOW TO MOVE INTO THE FAR NORTHERN
PORTIONS OF THE CWA EARLY TUESDAY MORNING AND THEN SPREAD SOUTH AND
EAST. AGAIN...IT LOOKS LIKE THE FAR SOUTHERN COUNTIES OF THE CWA
WILL SEE LITTLE OR NO SNOW WHILE THE FAR NORTHERN COUNTIES MAY SEE 1
TO 2 INCHES BEFORE COMING TO AN END IN THE LATE AFTERNOON HOURS.
FOR THE LONGER TERM...FROM WEDNESDAY THROUGH NEXT WEEKEND...THE
LONGER RANGE MODEL GUIDANCE IS STILL IN VERY GOOD AGREEMENT ON
BREAKING DOWN THE UPPER LEVEL LONG WAVE PATTERN AND BECOMING MORE
PROGRESSIVE. THIS WILL ALLOW FOR TEMPERATURES TO MODERATE WITH
HIGHS IN THE UPPER 30S TO MIDDLE 40S...WITH SOME UPPER 40S POSSIBLE
OVER THE SOUTHERN PORTIONS OF THE CWA. ALSO...AS THE UPPER LEVEL
PATTERN FLATTENS...MORE PACIFIC SHORT WAVE ENERGY WILL BE ABLE TO
IMPACT THE AREA...BRINGING PERIODIC CHANCES FOR RAIN AS WELL AS SOME
SNOW...BUT WITH THE WARMING TREND...ANY SNOW SHOULD BE ON THE
WET...SLUSHY SIDE.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* WINDS GRADUALLY SHIFTING FROM EAST TO NORTHEAST AND THEN NORTH-
NORTHWEST THIS AFTERNOON. SPEEDS UP TO 12-14 KT.
* AREAS OF LAKE-ENHANCED SNOW IN THE CHICAGO METROPOLITAN AREA
EXPECTED TO REMAIN EAST OF ORD AND MDW.
PAW
//DISCUSSION...UPDATED 18Z...
LOW PRESSURE CENTER IN CENTRAL IL WILL MOVE EAST THIS AFTERNOON.
THIS WILL ALLOW WINDS TO SHIFT MORE TO THE NORTHEAST AND THEN
NORTH-NORTHWEST DURING THE AFTERNOON. THE EASTERLY WINDS FROM
THIS MORNING ARE SUPPORTING SOME BANDS OF LAKE-ENHANCED SNOW OVER
THE CHICAGO METROPOLITAN AREA AT MIDDAY. AS WINDS SHIFT AROUND
THESE AREAS WILL MOVE CLOSER TO THE LAKE AND THEN INTO NORTHWEST
INDIANA. AT THIS TIME IT APPEARS THAT ONLY GYY WOULD BE VULNERABLE
TO SEEING SOME OF THIS SNOW AND EVEN THERE CONFIDENCE IS LOW.
ANOTHER IN THE SERIES OF CLIPPER SYSTEMS WILL BE MOVING ACROSS THE
TERMINALS ON TUESDAY. THIS ONE WILL BE FURTHER NORTH AND SO THE
THE TERMINALS SHOULD BE ON THE FRINGE OF THE SNOW AREAS THIS TIME.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN WIND TREND. MEDIUM CONFIDENCE IN TIMING.
* MEDIUM CONFIDENCE IN SNOW AREAS REMAINING EAST OF ORD AND MDW.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR PSBL MVFR WITH LIGHT SNOW.
WEDNESDAY...VFR.
THURSDAY...PSBL MVFR WITH LIGHT RAIN/SNOW.
FRIDAY...VFR.
SATURDAY...VFR. PSBL MVFR WITH RAIN IN THE AFTN.
SUNDAY...MVFR. CHANCE OF RAIN.
BEACHLER
&&
.MARINE...
257 AM CST
ANOTHER AREA OF LOW PRESSURE WAS SLIDING EAST ACROSS IOWA INTO THE
OHIO VALLEY TODAY...WHICH WILL ALLOW A SLIGHT INCREASE IN THE WIND
GRADIENT FOR THE SOUTHERN HALF OF LAKE MICHIGAN. HIGH PRESSURE
WILL THEN QUICKLY BUILD IN FROM THE WEST AND PROVIDE RELATIVELY
QUIET WEATHER FOR LAKE MICHIGAN...BEFORE YET ANOTHER LOW PRESSURE
SLIDES INTO THE UPPER MIDWEST LATE TONIGHT/EARLY TUESDAY AND
ARRIVES ACROSS THE WESTERN GREAT LAKES TUESDAY AFTERNOON/EVENING.
THE GRADIENT DOES APPEAR TO INCREASE PRIOR AND JUST AFTER THIS
SYSTEM...THEN ANOTHER RIDGE OF HIGH PRESSURE IS FORECAST TO PUSH
INTO THE WESTERN GREAT LAKES REGION FOR WEDNESDAY. THIS RIDGE OF
HIGH PRESSURE WILL THEN SLIDE EAST TO THE EASTERN OHIO VALLEY
WEDNESDAY NIGHT...WITH AN INCREASING GRADIENT AND SOUTHERLY FLOW
FOR EARLY THURSDAY ACROSS LAKE MICHIGAN. THE GRADIENT THEN
INCREASES FURTHER ACROSS THE FAR NORTHERN PORTION OF THE LAKE
MIDDAY THURSDAY AS A WEAK LOW PRESSURE SLIDES OVER THE SOUTHERN
PORTION OF THE LAKE.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ006-ILZ014 UNTIL 4 PM MONDAY.
IN...WINTER WEATHER ADVISORY...INZ001-INZ002 UNTIL 6 PM MONDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1138 AM CST MON FEB 4 2013
.DISCUSSION...
ISSUED 1045 AM CST MON FEB 4 2013
UPDATING THE FORECAST TO INCREASE HIGH TEMPERATURES A FEW MORE
DEGREES. A FEW CITIES HAVE ALREADY REACH CURRENT HIGH TEMPS OR
EVEN A DEGREE OR TWO ABOVE LIKE GALESBURG AND PEORIA. HIGHS TO
RANGE FROM THE MID 30S NW OF THE IL RIVER...TO 40-45F OVER SW
AREAS AND NEAR 40F IN SE IL. CONTINUED SLIGHT CHANCE OF LIGHT
RAIN/SNOW IN EASTERN IL ESPECIALLY THIS AFTERNOON. 1010 LOW
PRESSURE OVER WEST CENTRAL IL TO WEAKEN AS IT TRACKS ESE ACROSS
CENTRAL IL AND INTO THE CENTRAL OHIO VALLEY BY SUNSET. WINDS WILL
SHIFT AROUND TO THE NNW BEHIND THIS SYSTEM DURING THE COURSE OF
THE AFTERNOON BRINGING IN COOLER AIR.
07
&&
.AVIATION...
ISSUED 1135 AM CST MON FEB 4 2013
1010 MB LOW PRESSURE OVER WEST CENTRAL IL HAS SW WINDS 10-15 KTS
AHEAD OF IT EAST OF THE IL RIVER AND WINDS TURN NNW BEHIND ITS
FRONT BY PIA/IL RIVER. LOW PRESSURE TO WEAKEN AS IT TRACKS ESE
THROUGH CENTRAL IL THIS AFTERNOON AND INTO THE CENTRAL OHIO VALLEY
BY SUNSET. SW WINDS EAST OF THE IL RIVER TO SHIFT NNW DURING THE
NEXT 1-3 HOURS...SHIFTING LAST AT CMI AND DEC. VFR CONDITIONS MUCH
OF THIS AFTERNOON OVER CENTRAL IL WITH SCATTERED-BROKEN MID/HIGH
CLOUDS. HRRR MODEL DEPICTS MVFR CLOUDS OVER IA AND NORTHERN IL
WELL AND USED THIS MODEL TO BRING THESE CLOUDS GRADUALLY SOUTHWARD
TO PIA AROUND 2030Z...BMI AROUND 22Z AND NEAR I-72 AROUND 00Z.
HRRR MODELS SHOWS THESE LOW CLOUDS LINGERING OVER CENTRAL IL
THIS EVENING. NAM LOW LEVEL RH FIELDS SHOWS THESE LOW CLOUDS
DECREASING FROM NW TO SE LATE TONIGHT AND TUE MORNING. A LIGHT FOG
WITH 4-6 MILES VSBYS POSSIBLE LATER TONIGHT INTO MID MORNING TUE.
WINDS BECOME LIGHT OVERNIGHT AND TURN BACK TO THE SW 10-15 KTS
DURING TUE MORNING. 1001 MB LOW PRESSURE OVER EASTCENTRAL ALBERTA
TO DIVE SE INTO NW LOWER MI BY 18Z/NOON TUE KEEPING IT LIGHT SNOW
AND LOW CLOUDS MAINLY NORTH OF I-74 TUE.
07
&&
.PREV DISCUSSION...
ISSUED 306 AM CST MON FEB 4 2013
WEAK HIGH PRESSURE SLIDING EAST AS ANOTHER WAVE OF PRECIP MOVES
ACROSS NRN IL THIS MORNING. NOT QUITE OUT OF THE INFLUENCE OF THE
PATTERN JUST YET...THE FIRST COUPLE OF ISSUES FOR THE FORECAST ARE
THE NEXT CLIPPER SYSTEMS MOVING THROUGH THE MIDWEST UNTIL THE END
OF THE WEEK. CONSIDERING THE PATTERN...THE AGREEMENT BTWN THE
MODELS IS IMPRESSIVE. NOT A LOT OF CHANGE IN THE FORECAST OVERALL
AS SOME RUN TO RUN CONSISTENCY IN THE MED AND LONGER RANGE. SOME
MINOR ISSUES IN THE SHORT TERM WITH PRECIP TODAY. ANOTHER ISSUE
FOR AS A RESULT OF THE SERIES OF WAVES MOVING THROUGH...NON
DIURNAL TEMPS FOR A COUPLE OF PERIODS. OVERALL...FORECAST
REMAINING RATHER CONSISTENT.
SHORT TERM...TODAY AND TOMORROW...
SNOW AND ASSOCIATED SHORT WAVE TO THE NORTH THIS MORNING WAS
PREVIOUSLY SET TO COLLIDE WITH ANOTHER WAVE TO THE SOUTH MIDDAY.
HOWEVER...WAVE TO THE NORTH A LITTLE AHEAD OF SCHEDULE...WITH SFC
WAVE TO THE SOUTHWEST LAGGING A BIT BEHIND. HAVE PULLED POPS DOWN
A BIT TO REFLECT THE DROP IN PROBABILITY...KEEPING SLIGHTS IN THIS
MORNING FOR EASTERN HALF OF CWA. BUT THIS AFTERNOON MAY SEE A
BETTER CHANCE WITH THE SOUTHERN WAVE IN THE SE. NAM/ECMWF/GFS
TRENDING A LITTLE DRIER...AND THE RUC IS COMPLETELY DRY THIS
AFTERNOON UNTIL THE WAVE PULLS OUT LATER THIS AFTERNOON. TEMPS A
BIT WARMER TODAY AS WELL WITH A SOUTHERLY COMPONENT RETURNING TO
THE SFC FLOW...ALBEIT WEAK. TOMORROWS WAVE PASSING JUST TO THE
NORTH AND CHANCES FOR PRECIP CONFINED WELL TO THE NORTH
AGAIN...WITH SIMILAR TEMPS TOMORROW AS TODAY...WITH BREEZY
WESTERLY WINDS KEEPING SOME WARM AIR MOVING INTO THE CWA.
LONG TERM...WEDNESDAY THROUGH SUNDAY...
WEDNESDAY DRY AND WARM AGAIN AHEAD OF THE NEXT SYSTEM FOR WED
NIGHT INTO THURSDAY. THOUGH THREAT FROM THE WEST WILL INCREASE FOR
THE OVERNIGHT HOURS ON WED NIGHT...THE BEST CHANCES WILL COME WITH
THE PASSAGE OF THE SFC BOUNDARY ON THUR/THU NIGHT. LAST MODEL RUN
DIVERGES SOMEWHAT WITH THE SOLUTIONS FOR THIS PARTICULAR WAVE. A
TROF DEEPENS OVER THE WEST COAST...AND THIS PARTICULAR SYSTEM IS
A SMALL PIECE OF THE ENERGY EJECTING OUT AHEAD OF THE MAIN TROF.
THE ECMWF IS FAR MORE AMPLIFIED WITH THIS SMALL WAVE...AND THE GFS
IS A BIT LESS SO...WITH A WEAKER BUT MORE DIFFUSE AND SLOWER
PASSAGE OF THE SFC SYSTEM UNTIL IT PASSES ILX FA. CONCERNS FOR THE
SOLUTION DIFFERENCES ARE MINIMAL AT THIS POINT...AS MAJORITY OF
THU AFTERNOON AND INTO THE EVENING ARE RAIN. SOLUTION DIFFERENCES
WILL LIKELY IMPACT QPF AS TIME GETS CLOSER. MAIN ISSUE WITH THIS
SYSTEM AT THIS POINT IS THE CONCERN FOR FZRA IN THE NRN HALF OF
THE CWA WITH THE MORNING PRECIP ON THURSDAY. NEXT SYSTEM OF
INTEREST WILL MOVE INTO THE REGION SAT/SUN CREATING THE POTENTIAL
FOR A MESSY WEEKEND. HOWEVER...THE HANDLING OF THE WAVE/TROF OVER
THE WEST VARIES WIDELY BTWN THE ECMWF AND THE GFS...AND FROM THEIR
PREVIOUS SOLUTIONS...AND WILL KEEP THE MENTION CONSERVATIVE FOR
NOW.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1045 AM CST MON FEB 4 2013
.DISCUSSION...
ISSUED 1045 AM CST MON FEB 4 2013
UPDATING THE FORECAST TO INCREASE HIGH TEMPERATURES A FEW MORE
DEGREES. A FEW CITIES HAVE ALREADY REACH CURRENT HIGH TEMPS OR
EVEN A DEGREE OR TWO ABOVE LIKE GALESBURG AND PEORIA. HIGHS TO
RANGE FROM THE MID 30S NW OF THE IL RIVER...TO 40-45F OVER SW
AREAS AND NEAR 40F IN SE IL. CONTINUED SLIGHT CHANCE OF LIGHT
RAIN/SNOW IN EASTERN IL ESPECIALLY THIS AFTERNOON. 1010 LOW
PRESSURE OVER WEST CENTRAL IL TO WEAKEN AS IT TRACKS ESE ACROSS
CENTRAL IL AND INTO THE CENTRAL OHIO VALLEY BY SUNSET. WINDS WILL
SHIFT AROUND TO THE NNW BEHIND THIS SYSTEM DURING THE COURSE OF
THE AFTERNOON BRINGING IN COOLER AIR.
07
&&
.AVIATION...
ISSUED 610 AM CST MON FEB 4 2013
UPDATED TAFS SHORTLY AFTER 12Z ISSUANCE TO INCLUDE LLWS FOR I-72
SITES. KILX 12Z SOUNDING INDICATES 40KTS AT 1400FT SUGGESTING THAT
MODELS ARE UNDERESTIMATING STRENGTH OF LOW-LEVEL JET AHEAD OF IOWA
SURFACE LOW. JET WILL LIKELY MIX OUT AND WEAKEN BY MIDDLE MORNING
AND WILL ONLY CARRY LLWS UNTIL 16Z.
ORIGINAL 12Z AVIATION AFD...
SURFACE LOW CURRENTLY CENTERED OVER SOUTHEAST IOWA IS EXPECTED TO
TRACK SOUTHEAST ALONG INTERSTATE 74 THROUGH THIS AFTERNOON. LOW
CLOUDS AND PCPN HAS BEEN CONFINED TO LOCATIONS NORTH OF THE
CENTRAL ILLINOIS TERMINALS WITH MID-DECKS IN PLACE. AS LOW MOVES
ACROSS THE AREA...LOW LEVEL MOISTURE WILL LIKELY ADVECT AROUND THE
LOW AND BRING IN MVFR CIGS AND WINDSHIFT TO THE NORTH. THIS SHOULD
OCCUR AT KPIA AND KBMI BY 18Z AND BY 20Z AT KCMI.
OVERNIGHT...WINDS WILL DIMINISH AS SURFACE RIDGING BUILDS INTO
ILLINOIS. THOUGH DEEP MOISTURE WILL LIKELY BE PUSHED EAST OF THE
AREA...HIGH BOUNDARY LAYER MOISTURE TRAPPED BELOW THE SUBSIDENCE
WILL LIKELY BE SUFFICIENT TO KEEP MVFR...AND ISOLATED IFR...CIGS
IN PLACE.
BARKER
&&
.PREV DISCUSSION...
ISSUED 306 AM CST MON FEB 4 2013
WEAK HIGH PRESSURE SLIDING EAST AS ANOTHER WAVE OF PRECIP MOVES
ACROSS NRN IL THIS MORNING. NOT QUITE OUT OF THE INFLUENCE OF THE
PATTERN JUST YET...THE FIRST COUPLE OF ISSUES FOR THE FORECAST ARE
THE NEXT CLIPPER SYSTEMS MOVING THROUGH THE MIDWEST UNTIL THE END
OF THE WEEK. CONSIDERING THE PATTERN...THE AGREEMENT BTWN THE
MODELS IS IMPRESSIVE. NOT A LOT OF CHANGE IN THE FORECAST OVERALL
AS SOME RUN TO RUN CONSISTENCY IN THE MED AND LONGER RANGE. SOME
MINOR ISSUES IN THE SHORT TERM WITH PRECIP TODAY. ANOTHER ISSUE
FOR AS A RESULT OF THE SERIES OF WAVES MOVING THROUGH...NON
DIURNAL TEMPS FOR A COUPLE OF PERIODS. OVERALL...FORECAST
REMAINING RATHER CONSISTENT.
SHORT TERM...TODAY AND TOMORROW...
SNOW AND ASSOCIATED SHORT WAVE TO THE NORTH THIS MORNING WAS
PREVIOUSLY SET TO COLLIDE WITH ANOTHER WAVE TO THE SOUTH MIDDAY.
HOWEVER...WAVE TO THE NORTH A LITTLE AHEAD OF SCHEDULE...WITH SFC
WAVE TO THE SOUTHWEST LAGGING A BIT BEHIND. HAVE PULLED POPS DOWN
A BIT TO REFLECT THE DROP IN PROBABILITY...KEEPING SLIGHTS IN THIS
MORNING FOR EASTERN HALF OF CWA. BUT THIS AFTERNOON MAY SEE A
BETTER CHANCE WITH THE SOUTHERN WAVE IN THE SE. NAM/ECMWF/GFS
TRENDING A LITTLE DRIER...AND THE RUC IS COMPLETELY DRY THIS
AFTERNOON UNTIL THE WAVE PULLS OUT LATER THIS AFTERNOON. TEMPS A
BIT WARMER TODAY AS WELL WITH A SOUTHERLY COMPONENT RETURNING TO
THE SFC FLOW...ALBEIT WEAK. TOMORROWS WAVE PASSING JUST TO THE
NORTH AND CHANCES FOR PRECIP CONFINED WELL TO THE NORTH
AGAIN...WITH SIMILAR TEMPS TOMORROW AS TODAY...WITH BREEZY
WESTERLY WINDS KEEPING SOME WARM AIR MOVING INTO THE CWA.
LONG TERM...WEDNESDAY THROUGH SUNDAY...
WEDNESDAY DRY AND WARM AGAIN AHEAD OF THE NEXT SYSTEM FOR WED
NIGHT INTO THURSDAY. THOUGH THREAT FROM THE WEST WILL INCREASE FOR
THE OVERNIGHT HOURS ON WED NIGHT...THE BEST CHANCES WILL COME WITH
THE PASSAGE OF THE SFC BOUNDARY ON THUR/THU NIGHT. LAST MODEL RUN
DIVERGES SOMEWHAT WITH THE SOLUTIONS FOR THIS PARTICULAR WAVE. A
TROF DEEPENS OVER THE WEST COAST...AND THIS PARTICULAR SYSTEM IS
A SMALL PIECE OF THE ENERGY EJECTING OUT AHEAD OF THE MAIN TROF.
THE ECMWF IS FAR MORE AMPLIFIED WITH THIS SMALL WAVE...AND THE GFS
IS A BIT LESS SO...WITH A WEAKER BUT MORE DIFFUSE AND SLOWER
PASSAGE OF THE SFC SYSTEM UNTIL IT PASSES ILX FA. CONCERNS FOR THE
SOLUTION DIFFERENCES ARE MINIMAL AT THIS POINT...AS MAJORITY OF
THU AFTERNOON AND INTO THE EVENING ARE RAIN. SOLUTION DIFFERENCES
WILL LIKELY IMPACT QPF AS TIME GETS CLOSER. MAIN ISSUE WITH THIS
SYSTEM AT THIS POINT IS THE CONCERN FOR FZRA IN THE NRN HALF OF
THE CWA WITH THE MORNING PRECIP ON THURSDAY. NEXT SYSTEM OF
INTEREST WILL MOVE INTO THE REGION SAT/SUN CREATING THE POTENTIAL
FOR A MESSY WEEKEND. HOWEVER...THE HANDLING OF THE WAVE/TROF OVER
THE WEST VARIES WIDELY BTWN THE ECMWF AND THE GFS...AND FROM THEIR
PREVIOUS SOLUTIONS...AND WILL KEEP THE MENTION CONSERVATIVE FOR
NOW.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
610 AM CST MON FEB 4 2013
.DISCUSSION...
ISSUED 306 AM CST MON FEB 4 2013
WEAK HIGH PRESSURE SLIDING EAST AS ANOTHER WAVE OF PRECIP MOVES
ACROSS NRN IL THIS MORNING. NOT QUITE OUT OF THE INFLUENCE OF THE
PATTERN JUST YET...THE FIRST COUPLE OF ISSUES FOR THE FORECAST ARE
THE NEXT CLIPPER SYSTEMS MOVING THROUGH THE MIDWEST UNTIL THE END
OF THE WEEK. CONSIDERING THE PATTERN...THE AGREEMENT BTWN THE
MODELS IS IMPRESSIVE. NOT A LOT OF CHANGE IN THE FORECAST OVERALL
AS SOME RUN TO RUN CONSISTENCY IN THE MED AND LONGER RANGE. SOME
MINOR ISSUES IN THE SHORT TERM WITH PRECIP TODAY. ANOTHER ISSUE
FOR AS A RESULT OF THE SERIES OF WAVES MOVING THROUGH...NON
DIURNAL TEMPS FOR A COUPLE OF PERIODS. OVERALL...FORECAST
REMAINING RATHER CONSISTENT.
SHORT TERM...TODAY AND TOMORROW...
SNOW AND ASSOCIATED SHORT WAVE TO THE NORTH THIS MORNING WAS
PREVIOUSLY SET TO COLLIDE WITH ANOTHER WAVE TO THE SOUTH MIDDAY.
HOWEVER...WAVE TO THE NORTH A LITTLE AHEAD OF SCHEDULE...WITH SFC
WAVE TO THE SOUTHWEST LAGGING A BIT BEHIND. HAVE PULLED POPS DOWN
A BIT TO REFLECT THE DROP IN PROBABILITY...KEEPING SLIGHTS IN THIS
MORNING FOR EASTERN HALF OF CWA. BUT THIS AFTERNOON MAY SEE A
BETTER CHANCE WITH THE SOUTHERN WAVE IN THE SE. NAM/ECMWF/GFS
TRENDING A LITTLE DRIER...AND THE RUC IS COMPLETELY DRY THIS
AFTERNOON UNTIL THE WAVE PULLS OUT LATER THIS AFTERNOON. TEMPS A
BIT WARMER TODAY AS WELL WITH A SOUTHERLY COMPONENT RETURNING TO
THE SFC FLOW...ALBEIT WEAK. TOMORROWS WAVE PASSING JUST TO THE
NORTH AND CHANCES FOR PRECIP CONFINED WELL TO THE NORTH
AGAIN...WITH SIMILAR TEMPS TOMORROW AS TODAY...WITH BREEZY
WESTERLY WINDS KEEPING SOME WARM AIR MOVING INTO THE CWA.
LONG TERM...WEDNESDAY THROUGH SUNDAY...
WEDNESDAY DRY AND WARM AGAIN AHEAD OF THE NEXT SYSTEM FOR WED
NIGHT INTO THURSDAY. THOUGH THREAT FROM THE WEST WILL INCREASE FOR
THE OVERNIGHT HOURS ON WED NIGHT...THE BEST CHANCES WILL COME WITH
THE PASSAGE OF THE SFC BOUNDARY ON THUR/THU NIGHT. LAST MODEL RUN
DIVERGES SOMEWHAT WITH THE SOLUTIONS FOR THIS PARTICULAR WAVE. A
TROF DEEPENS OVER THE WEST COAST...AND THIS PARTICULAR SYSTEM IS
A SMALL PIECE OF THE ENERGY EJECTING OUT AHEAD OF THE MAIN TROF.
THE ECMWF IS FAR MORE AMPLIFIED WITH THIS SMALL WAVE...AND THE GFS
IS A BIT LESS SO...WITH A WEAKER BUT MORE DIFFUSE AND SLOWER
PASSAGE OF THE SFC SYSTEM UNTIL IT PASSES ILX FA. CONCERNS FOR THE
SOLUTION DIFFERENCES ARE MINIMAL AT THIS POINT...AS MAJORITY OF
THU AFTERNOON AND INTO THE EVENING ARE RAIN. SOLUTION DIFFERENCES
WILL LIKELY IMPACT QPF AS TIME GETS CLOSER. MAIN ISSUE WITH THIS
SYSTEM AT THIS POINT IS THE CONCERN FOR FZRA IN THE NRN HALF OF
THE CWA WITH THE MORNING PRECIP ON THURSDAY. NEXT SYSTEM OF
INTEREST WILL MOVE INTO THE REGION SAT/SUN CREATING THE POTENTIAL
FOR A MESSY WEEKEND. HOWEVER...THE HANDLING OF THE WAVE/TROF OVER
THE WEST VARIES WIDELY BTWN THE ECMWF AND THE GFS...AND FROM THEIR
PREVIOUS SOLUTIONS...AND WILL KEEP THE MENTION CONSERVATIVE FOR
NOW.
&&
.AVIATION...
ISSUED 610 AM CST MON FEB 4 2013
UPDATED TAFS SHORTLY AFTER 12Z ISSUANCE TO INCLUDE LLWS FOR I-72
SITES. KILX 12Z SOUNDING INDICATES 40KTS AT 1400FT SUGGESTING THAT
MODELS ARE UNDERESTIMATING STRENGTH OF LOW-LEVEL JET AHEAD OF IOWA
SURFACE LOW. JET WILL LIKELY MIX OUT AND WEAKEN BY MIDDLE MORNING
AND WILL ONLY CARRY LLWS UNTIL 16Z.
ORIGINAL 12Z AVIATION AFD...
SURFACE LOW CURRENTLY CENTERED OVER SOUTHEAST IOWA IS EXPECTED TO
TRACK SOUTHEAST ALONG INTERSTATE 74 THROUGH THIS AFTERNOON. LOW
CLOUDS AND PCPN HAS BEEN CONFINED TO LOCATIONS NORTH OF THE
CENTRAL ILLINOIS TERMINALS WITH MID-DECKS IN PLACE. AS LOW MOVES
ACROSS THE AREA...LOW LEVEL MOISTURE WILL LIKELY ADVECT AROUND THE
LOW AND BRING IN MVFR CIGS AND WINDSHIFT TO THE NORTH. THIS SHOULD
OCCUR AT KPIA AND KBMI BY 18Z AND BY 20Z AT KCMI.
OVERNIGHT...WINDS WILL DIMINISH AS SURFACE RIDGING BUILDS INTO
ILLINOIS. THOUGH DEEP MOISTURE WILL LIKELY BE PUSHED EAST OF THE
AREA...HIGH BOUNDARY LAYER MOISTURE TRAPPED BELOW THE SUBSIDENCE
WILL LIKELY BE SUFFICIENT TO KEEP MVFR...AND ISOLATED IFR...CIGS
IN PLACE.
BARKER
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
526 AM CST MON FEB 4 2013
.DISCUSSION...
ISSUED 306 AM CST MON FEB 4 2013
WEAK HIGH PRESSURE SLIDING EAST AS ANOTHER WAVE OF PRECIP MOVES
ACROSS NRN IL THIS MORNING. NOT QUITE OUT OF THE INFLUENCE OF THE
PATTERN JUST YET...THE FIRST COUPLE OF ISSUES FOR THE FORECAST ARE
THE NEXT CLIPPER SYSTEMS MOVING THROUGH THE MIDWEST UNTIL THE END
OF THE WEEK. CONSIDERING THE PATTERN...THE AGREEMENT BTWN THE
MODELS IS IMPRESSIVE. NOT A LOT OF CHANGE IN THE FORECAST OVERALL
AS SOME RUN TO RUN CONSISTENCY IN THE MED AND LONGER RANGE. SOME
MINOR ISSUES IN THE SHORT TERM WITH PRECIP TODAY. ANOTHER ISSUE
FOR AS A RESULT OF THE SERIES OF WAVES MOVING THROUGH...NON
DIURNAL TEMPS FOR A COUPLE OF PERIODS. OVERALL...FORECAST
REMAINING RATHER CONSISTENT.
SHORT TERM...TODAY AND TOMORROW...
SNOW AND ASSOCIATED SHORT WAVE TO THE NORTH THIS MORNING WAS
PREVIOUSLY SET TO COLLIDE WITH ANOTHER WAVE TO THE SOUTH MIDDAY.
HOWEVER...WAVE TO THE NORTH A LITTLE AHEAD OF SCHEDULE...WITH SFC
WAVE TO THE SOUTHWEST LAGGING A BIT BEHIND. HAVE PULLED POPS DOWN
A BIT TO REFLECT THE DROP IN PROBABILITY...KEEPING SLIGHTS IN THIS
MORNING FOR EASTERN HALF OF CWA. BUT THIS AFTERNOON MAY SEE A
BETTER CHANCE WITH THE SOUTHERN WAVE IN THE SE. NAM/ECMWF/GFS
TRENDING A LITTLE DRIER...AND THE RUC IS COMPLETELY DRY THIS
AFTERNOON UNTIL THE WAVE PULLS OUT LATER THIS AFTERNOON. TEMPS A
BIT WARMER TODAY AS WELL WITH A SOUTHERLY COMPONENT RETURNING TO
THE SFC FLOW...ALBEIT WEAK. TOMORROWS WAVE PASSING JUST TO THE
NORTH AND CHANCES FOR PRECIP CONFINED WELL TO THE NORTH
AGAIN...WITH SIMILAR TEMPS TOMORROW AS TODAY...WITH BREEZY
WESTERLY WINDS KEEPING SOME WARM AIR MOVING INTO THE CWA.
LONG TERM...WEDNESDAY THROUGH SUNDAY...
WEDNESDAY DRY AND WARM AGAIN AHEAD OF THE NEXT SYSTEM FOR WED
NIGHT INTO THURSDAY. THOUGH THREAT FROM THE WEST WILL INCREASE FOR
THE OVERNIGHT HOURS ON WED NIGHT...THE BEST CHANCES WILL COME WITH
THE PASSAGE OF THE SFC BOUNDARY ON THUR/THU NIGHT. LAST MODEL RUN
DIVERGES SOMEWHAT WITH THE SOLUTIONS FOR THIS PARTICULAR WAVE. A
TROF DEEPENS OVER THE WEST COAST...AND THIS PARTICULAR SYSTEM IS
A SMALL PIECE OF THE ENERGY EJECTING OUT AHEAD OF THE MAIN TROF.
THE ECMWF IS FAR MORE AMPLIFIED WITH THIS SMALL WAVE...AND THE GFS
IS A BIT LESS SO...WITH A WEAKER BUT MORE DIFFUSE AND SLOWER
PASSAGE OF THE SFC SYSTEM UNTIL IT PASSES ILX FA. CONCERNS FOR THE
SOLUTION DIFFERENCES ARE MINIMAL AT THIS POINT...AS MAJORITY OF
THU AFTERNOON AND INTO THE EVENING ARE RAIN. SOLUTION DIFFERENCES
WILL LIKELY IMPACT QPF AS TIME GETS CLOSER. MAIN ISSUE WITH THIS
SYSTEM AT THIS POINT IS THE CONCERN FOR FZRA IN THE NRN HALF OF
THE CWA WITH THE MORNING PRECIP ON THURSDAY. NEXT SYSTEM OF
INTEREST WILL MOVE INTO THE REGION SAT/SUN CREATING THE POTENTIAL
FOR A MESSY WEEKEND. HOWEVER...THE HANDLING OF THE WAVE/TROF OVER
THE WEST VARIES WIDELY BTWN THE ECMWF AND THE GFS...AND FROM THEIR
PREVIOUS SOLUTIONS...AND WILL KEEP THE MENTION CONSERVATIVE FOR
NOW.
&&
.AVIATION...
ISSUED 526 AM CST MON FEB 4 2013
SURFACE LOW CURRENTLY CENTERED OVER SOUTHEAST IOWA IS EXPECTED TO
TRACK SOUTHEAST ALONG INTERSTATE 74 THROUGH THIS AFTERNOON. LOW
CLOUDS AND PCPN HAS BEEN CONFINED TO LOCATIONS NORTH OF THE
CENTRAL ILLINOIS TERMINALS WITH MID-DECKS IN PLACE. AS LOW MOVES
ACROSS THE AREA...LOW LEVEL MOISTURE WILL LIKELY ADVECT AROUND THE
LOW AND BRING IN MVFR CIGS AND WINDSHIFT TO THE NORTH. THIS SHOULD
OCCUR AT KPIA AND KBMI BY 18Z AND BY 20Z AT KCMI.
OVERNIGHT...WINDS WILL DIMINISH AS SURFACE RIDGING BUILDS INTO
ILLINOIS. THOUGH DEEP MOISTURE WILL LIKELY BE PUSHED EAST OF THE
AREA...HIGH BOUNDARY LAYER MOISTURE TRAPPED BELOW THE SUBSIDENCE
WILL LIKELY BE SUFFICIENT TO KEEP MVFR...AND ISOLATED IFR...CIGS
IN PLACE.
BARKER
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
333 AM CST MON FEB 4 2013
.DISCUSSION...
ISSUED 306 AM CST MON FEB 4 2013
WEAK HIGH PRESSURE SLIDING EAST AS ANOTHER WAVE OF PRECIP MOVES
ACROSS NRN IL THIS MORNING. NOT QUITE OUT OF THE INFLUENCE OF THE
PATTERN JUST YET...THE FIRST COUPLE OF ISSUES FOR THE FORECAST ARE
THE NEXT CLIPPER SYSTEMS MOVING THROUGH THE MIDWEST UNTIL THE END
OF THE WEEK. CONSIDERING THE PATTERN...THE AGREEMENT BTWN THE
MODELS IS IMPRESSIVE. NOT A LOT OF CHANGE IN THE FORECAST OVERALL
AS SOME RUN TO RUN CONSISTENCY IN THE MED AND LONGER RANGE. SOME
MINOR ISSUES IN THE SHORT TERM WITH PRECIP TODAY. ANOTHER ISSUE
FOR AS A RESULT OF THE SERIES OF WAVES MOVING THROUGH...NON
DIURNAL TEMPS FOR A COUPLE OF PERIODS. OVERALL...FORECAST
REMAINING RATHER CONSISTENT.
SHORT TERM...TODAY AND TOMORROW...
SNOW AND ASSOCIATED SHORT WAVE TO THE NORTH THIS MORNING WAS
PREVIOUSLY SET TO COLLIDE WITH ANOTHER WAVE TO THE SOUTH MIDDAY.
HOWEVER...WAVE TO THE NORTH A LITTLE AHEAD OF SCHEDULE...WITH SFC
WAVE TO THE SOUTHWEST LAGGING A BIT BEHIND. HAVE PULLED POPS DOWN
A BIT TO REFLECT THE DROP IN PROBABILITY...KEEPING SLIGHTS IN THIS
MORNING FOR EASTERN HALF OF CWA. BUT THIS AFTERNOON MAY SEE A
BETTER CHANCE WITH THE SOUTHERN WAVE IN THE SE. NAM/ECMWF/GFS
TRENDING A LITTLE DRIER...AND THE RUC IS COMPLETELY DRY THIS
AFTERNOON UNTIL THE WAVE PULLS OUT LATER THIS AFTERNOON. TEMPS A
BIT WARMER TODAY AS WELL WITH A SOUTHERLY COMPONENT RETURNING TO
THE SFC FLOW...ALBEIT WEAK. TOMORROWS WAVE PASSING JUST TO THE
NORTH AND CHANCES FOR PRECIP CONFINED WELL TO THE NORTH
AGAIN...WITH SIMILAR TEMPS TOMORROW AS TODAY...WITH BREEZY
WESTERLY WINDS KEEPING SOME WARM AIR MOVING INTO THE CWA.
LONG TERM...WEDNESDAY THROUGH SUNDAY...
WEDNESDAY DRY AND WARM AGAIN AHEAD OF THE NEXT SYSTEM FOR WED
NIGHT INTO THURSDAY. THOUGH THREAT FROM THE WEST WILL INCREASE FOR
THE OVERNIGHT HOURS ON WED NIGHT...THE BEST CHANCES WILL COME WITH
THE PASSAGE OF THE SFC BOUNDARY ON THUR/THU NIGHT. LAST MODEL RUN
DIVERGES SOMEWHAT WITH THE SOLUTIONS FOR THIS PARTICULAR WAVE. A
TROF DEEPENS OVER THE WEST COAST...AND THIS PARTICULAR SYSTEM IS
A SMALL PIECE OF THE ENERGY EJECTING OUT AHEAD OF THE MAIN TROF.
THE ECMWF IS FAR MORE AMPLIFIED WITH THIS SMALL WAVE...AND THE GFS
IS A BIT LESS SO...WITH A WEAKER BUT MORE DIFFUSE AND SLOWER
PASSAGE OF THE SFC SYSTEM UNTIL IT PASSES ILX FA. CONCERNS FOR THE
SOLUTION DIFFERENCES ARE MINIMAL AT THIS POINT...AS MAJORITY OF
THU AFTERNOON AND INTO THE EVENING ARE RAIN. SOLUTION DIFFERENCES
WILL LIKELY IMPACT QPF AS TIME GETS CLOSER. MAIN ISSUE WITH THIS
SYSTEM AT THIS POINT IS THE CONCERN FOR FZRA IN THE NRN HALF OF
THE CWA WITH THE MORNING PRECIP ON THURSDAY. NEXT SYSTEM OF
INTEREST WILL MOVE INTO THE REGION SAT/SUN CREATING THE POTENTIAL
FOR A MESSY WEEKEND. HOWEVER...THE HANDLING OF THE WAVE/TROF OVER
THE WEST VARIES WIDELY BTWN THE ECMWF AND THE GFS...AND FROM THEIR
PREVIOUS SOLUTIONS...AND WILL KEEP THE MENTION CONSERVATIVE FOR
NOW.
HJS
&&
.AVIATION...
ISSUED 1135 PM CST SUN FEB 3 2013
WIDESPREAD MID AND HIGH CLOUDS EXPECTED OVERNIGHT...WITH SNOW
THREAT STILL TRACKING ACROSS NORTHERN ILLINOIS PER LATEST MODELS.
HAVE SOME CONCERN FOR LOW LEVEL WIND SHEAR...AS LOW PRESSURE
APPROACHES WEST CENTRAL ILLINOIS. CONDITIONS AT CENTRAL ILLINOIS
TAF SITES SHOULD FALL A BIT SHY FOR INCLUSION OF LLWS GROUP...BUT
FORECAST SOUNDINGS SHOWING WINDS TURNING SOUTHWEST AND INCREASING
TO AROUND 30-35 KNOTS BY AROUND 2000 FEET...BEGINNING AROUND 09Z
AROUND KPIA/KSPI AND TOWARD 15Z AT KCMI. THESE WOULD LAST FOR A
FEW HOURS BEFORE THE LOW ARRIVES.
SURFACE WINDS EXPECTED TO TURN NORTHWEST FOLLOWING PASSAGE OF A
COLD FRONT TOWARD MIDDAY. NAM AND RAP MODEL GUIDANCE INDICATE
MVFR CEILINGS LIKELY TO SPREAD IN BEHIND THIS FRONT FOR MUCH OF
THE AFTERNOON. ANY THREAT OF RAIN OR SNOW WOULD BE MORE LIKELY
AROUND KCMI...BUT CHANCES APPEAR LOW ENOUGH TO INCLUDE AT THIS
POINT. VFR CONDITIONS EXPECTED TO DEVELOP FROM WEST TO EAST
SHORTLY AFTER SUNSET.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1137 PM CST SUN FEB 3 2013
.DISCUSSION...
ISSUED 815 PM CST SUN FEB 3 2013
MAIN CONCERN OVERNIGHT WILL BE WITH TEMPERATURES...AS EVENING
READINGS HAVE BEEN RUNNING SEVERAL DEGREES ABOVE THE FORECAST
CURVE. HAVE MADE SOME ADJUSTMENTS TO COMPENSATE...AS RAPIDLY
INCREASING HIGH CLOUDS SHOULD PREVENT ANY SIGNIFICANT TEMPERATURE
FALLS OVER THE NEXT COUPLE HOURS. STILL LOOKS LIKE THEY SHOULD
STEADY OUT OR SLOWLY RISE AFTER MIDNIGHT.
LATEST RADAR MOSAICS LOOKING FAIRLY DRAMATIC OVER THE NORTHERN
THIRD OF ILLINOIS...BUT THESE RETURNS ARE LARGELY MID LEVEL
CLOUDS. LATEST MODELS CONTINUE TO INDICATE ANY SNOW THREAT WILL
REMAIN ACROSS NORTHERN ILLINOIS OVERNIGHT.
GEELHART
&&
.AVIATION...
ISSUED 1135 PM CST SUN FEB 3 2013
WIDESPREAD MID AND HIGH CLOUDS EXPECTED OVERNIGHT...WITH SNOW
THREAT STILL TRACKING ACROSS NORTHERN ILLINOIS PER LATEST MODELS.
HAVE SOME CONCERN FOR LOW LEVEL WIND SHEAR...AS LOW PRESSURE
APPROACHES WEST CENTRAL ILLINOIS. CONDITIONS AT CENTRAL ILLINOIS
TAF SITES SHOULD FALL A BIT SHY FOR INCLUSION OF LLWS GROUP...BUT
FORECAST SOUNDINGS SHOWING WINDS TURNING SOUTHWEST AND INCREASING
TO AROUND 30-35 KNOTS BY AROUND 2000 FEET...BEGINNING AROUND 09Z
AROUND KPIA/KSPI AND TOWARD 15Z AT KCMI. THESE WOULD LAST FOR A
FEW HOURS BEFORE THE LOW ARRIVES.
SURFACE WINDS EXPECTED TO TURN NORTHWEST FOLLOWING PASSAGE OF A
COLD FRONT TOWARD MIDDAY. NAM AND RAP MODEL GUIDANCE INDICATE
MVFR CEILINGS LIKELY TO SPREAD IN BEHIND THIS FRONT FOR MUCH OF
THE AFTERNOON. ANY THREAT OF RAIN OR SNOW WOULD BE MORE LIKELY
AROUND KCMI...BUT CHANCES APPEAR LOW ENOUGH TO INCLUDE AT THIS
POINT. VFR CONDITIONS EXPECTED TO DEVELOP FROM WEST TO EAST
SHORTLY AFTER SUNSET.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 249 PM CST SUN FEB 3 2013
A WAVE TRAIN OF WEATHER SYSTEMS WILL START OFF THE FORECAST...WITH
PRECIP CHANCES ON MONDAY, TUESDAY AND WED NIGHT-THURSDAY. THE LAST
SYSTEM OF NOTE FOR THIS FORECAST WILL BE DEEPER LOW PRESSURE
LIFTING THROUGH THE UPPER MIDWEST ON SAT NIGHT-SUNDAY...WITH A FEW
THUNDERSTORMS POSSIBLE SUNDAY ALONG WITH MODERATE RAINS AND VERY
MILD CONDITIONS.
SHORT TERM...TONIGHT THROUGH TUESDAY.
THE LINGERING FLURRIES FROM THE MOST RECENT SYSTEM WILL DEPART
FROM OUR EASTERN COUNTIES INTO INDIANA BY 4 PM. CLEARING SKIES
WILL CONTINUE TO PROGRESS EASTWARD IN THEIR WAKE. HOWEVER...A
QUICKLY ARRIVING MID-LEVEL CLOUD DECK WILL AFFECT SCHUYLER AND
FULTON COUNTIES BETWEEN 2 AND 3 PM...AND SLIDE EAST ACROSS AT
LEAST OUR NORTHERN COUNTIES THE REST OF THE AFTERNOON AND EVENING.
THAT INITIAL BAND OF CLOUDS IS RELATIVELY NARROW...BUT REINFORCING
MID-CLOUDS IN THE DAKOTAS AND SW MINNESOTA WILL EVENTUALLY SLIDE
SOUTHEAST TOWARD OUR COUNTIES MONDAY MORNING.
AN UPPER SHORTWAVE ON THE NORTHERN END OF AN INVERTED TROUGH WILL
TRIGGER A BAND OF LIGHT SNOW ACROSS SOUTHERN MINNESOTA INTO
NORTHERN ILLINOIS AND SOUTHERN WISCONSIN BETWEEN MIDNIGHT AND 6
AM. FLURRIES OR LIGHT SNOW COULD POSSIBLY EXTEND AS FAR SOUTH AS
LACON AND EL PASO BEFORE 6 AM MONDAY. LOW PRESSURE ON THE SOUTHERN
END OF THAT INVERTED TROUGH WILL MOVE ACROSS MISSOURI BY MONDAY
MORNING...EVENTUALLY PASSING ACROSS CENTRAL ILLINOIS. AS IT
REACHES EASTERN IL...IT WILL PHASE BETTER WITH THE UPPER WAVE AND
POSSIBLY TRIGGER LIGHT RAIN OR SNOW SHOWERS EAST OF I-57 AND
SOUTHWEST TO NEAR SHELBYVILLE. THE 12Z MODELS ARE SHOWING A DRIER
TREND IN OUR COUNTIES NEAR THE TRACK OF THAT SURFACE LOW.
HOWEVER...WE ONLY TRENDED A LITTLE LOWER WITH THE POPS INSTEAD OF
GOING COMPLETELY DRY WITH THE FIRST INDICATION OF NEARLY DRY
CONDITIONS ACROSS OUR EASTERN FORECAST AREA MONDAY INTO MONDAY
EVE.
ON TUESDAY...A CLIPPER-TYPE SYSTEM WILL MOVE SOUTHEAST FROM
MINNESOTA ACROSS WISC AND INTO THE EASTERN GREAT LAKES BY LATER
TUES NIGHT. THE PRIMARY REGION OF ISENTROPIC LIFT AND SHORTWAVE
FORCING FOR PRECIP WILL REMAIN NORTH OF OUR COUNTIES. WE MAY SEE
SOME FLURRIES ALONG AND NORTH OF I-74...BUT CHANCES OF MEASURABLE
SNOW IN OUR AREA ON TUESDAY LOOK QUITE LOW.
LONG TERM...WEDNESDAY THROUGH SUNDAY.
AS THE TUESDAY SYSTEM DEPARTS...A WARMING TREND WILL BEGIN ACROSS
THE AREA...IN RESPONSE TO A BUILDING RIDGE IN THE WESTERN PLAINS
STATES. THE UPPER FLOW WILL BECOME MORE ZONAL BRINGING IN MORE
PACIFIC BASED AIR.
IN THAT FAST WESTERLY FLOW...A LOW PRESSURE SYSTEM WILL DRAG A COLD
FRONT ACROSS IL ON THURSDAY. A BETTER TAP ON GULF MOISTURE WILL
BEGIN AHEAD OF THIS SYSTEM...BRINGING DEWPOINTS INTO THE UPPER 30S
AND HIGHS INTO THE LOW 40S NORTH AND NEAR 50 SOUTH. SHOWERS ARE
EXPECTED TO DEVELOP ALONG THE FRONT LATE WEDNESDAY NIGHT AND
THURS. RISING TEMPERATURES WED NIGHT SHOULD HELP TO KEEP THE
PRECIPITATION AS ONLY RAIN INSTEAD OF FREEZING RAIN...BUT WE CAN
NOT RULE OUT SOME AREAS AT OR BELOW FREEZING ACROSS THE NORTHWEST
WHEN RAIN BEGINS TO REACH THE GROUND BEFORE SUNRISE THURSDAY. THAT
SAME THERMAL PROFILE MAY BE PRESENT ALONG AND NORTH OF I-74 TOWARD
CHAMPAIGN/DANVILLE EARLY THURSDAY MORNING...WITH A PERIOD OF
FREEZING RAIN POSSIBLE. AT THIS POINT...THE WARMING SOUTHERLY
WINDS LOOK STRONG ENOUGH AT MID LEVELS TO WARM THE RAIN BETWEEN
+5C TO +7C. THAT WILL MAKE IT MORE DIFFICULT TO FREEZE RAIN FROM
THAT WARM OF A TEMPERATURE. ANY ICING WOULD MAINLY BE ON ELEVATED
SURFACES THAT REMAIN COLD IF AT ALL...AND THE ICE WOULD MELT BY
AFTERNOON AS AIR TEMPS RISE ABOVE FREEZING.
THE PRECIP WILL TAPER OFF AS THE COLDER AIR ARRIVES...POSSIBLE
CHANGING RAIN TO SNOW IN THE EAST/SOUTHEAST AREA.
THEN A BREAK IN THE PRECIP IS EXPECTED FROM LATER THURSDAY NIGHT
THROUGH FRIDAY NIGHT UNDER WEAK HIGH PRESSURE. WARMER TEMPS
THURSDAY WILL BE TEMPERED ON FRIDAY BEHIND THE COLD FRONT...BUT
SATURDAY WILL SEE HIGHS CLIMB WELL INTO THE 40S AHEAD OF THE STORM
SYSTEM DEVELOPING IN THE PLAINS. A SOLID TAP ON GULF MOISTURE BY
SUNDAY MORNING WILL SET THE STAGE FOR RAIN SHOWERS DEVELOPING
SATURDAY NIGHT. INSTABILITY PARAMETERS AND DYNAMIC FORCING LOOK
FAVORABLE FOR A WAVE OF THUNDERSTORMS IN CENTRAL IL ON SUNDAY INTO
SUNDAY EVENING. WE CANT RULE OUT THE POTENTIAL FOR A FEW SEVERE
STORMS SUNDAY AFTERNOON AND EVENING...MAINLY EAST OF THE ILLINOIS
RIVER. THE TRACK OF THE LOW WILL PLAY A MAJOR ROLL IN OUR
POTENTIAL FOR STORMS...AND WILL BE WATCHED CLOSELY IN THE COMING
WEEK.
SHIMON
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
344 PM CST MON FEB 4 2013
.DISCUSSION...
LATEST SURFACE ANALYSIS HAD HIGH PRESSURE BUILDING INTO NORTHEAST
KANSAS AT 20Z. STRATUS HAS BEEN ERODING NORTH OF INTERSTATE 70 THIS
AFTERNOON AREAS SOUTH OF I-70 HAVE REMAINED CLEAR TODAY.
LATEST RAP 13 RELATIVE HUMIDITY PLOTS KEEP THE LOWER LAYERS
SATURATED THROUGH THE EVENING. DEPENDING ON HOW WELL THE LOWER
BOUNDARY LAYER MIXES OUT THIS AFTERNOON...STATUS MAY MOVE BACK SOUTH
OR REFORM AFTER SUNSET. WILL KEEP SOME CLOUDS NORTH OF I-70 THIS
EVENING WITH MOSTLY CLEAR SKIES IN THE SOUTH. LOWS TONIGHT WILL
RANGE FROM THE LOWER 20S IN THE FAR NORTHEAST TO THE MID 20S
ELSEWHERE IN NORTHEAST...NORTH CENTRAL AND EAST CENTRAL KANSAS.
THE SURFACE HIGH MOVES OFF TO THE EAST TONIGHT WITH RETURN FLOW
OCCURRING AFTER 06Z TUESDAY. WARM ADVECTION OCCURS THROUGH MID DAY
TUESDAY BEFORE COOL ADVECTION OCCURS IN THE NORTHEAST IN THE
AFTERNOON. THEREFORE EXPECT THE COOLEST TEMPERATURES IN THE
NORTHEAST CORNER. THE HIGHS TUESDAY SHOULD RANGE FROM THE UPPER 40S
TO THE MID 50S.
53
.TUESDAY NIGHT THROUGH FRIDAY NIGHT...
RIDGING ALOFT WILL BUILD EASTWARD INTO THE PLAINS ON WEDNESDAY WITH
SOUTHERLY WINDS AND WARMER TEMPERATURES IN THE MIDDLE 50S NORTH TO
THE LOWER 60S SOUTH OF I 70. AS ANOTHER SHORTWAVE TROUGH NOW IN THE
PACIFIC ADVANCES QUICKLY EASTWARD INTO THE CENTRAL HIGH PLAINS...
IT WILL RESULT IN A RAPID RETURN OF MOISTURE NORTHWARD ACROSS
CENTRAL AND EASTERN KANSAS. AS A FRONT MOVES INTO THE CWA WEDNESDAY
EVENING...SHOWERS AND SOME ISOLATED THUNDERSTORMS ARE EXPECTED TO
DEVELOP WEST TO EAST THROUGH THE NIGHT...EXITING THE SOUTHEAST
CORNER OF THE COUNTY WARNING AREA BY MIDDAY THURSDAY AS THE FRONT
AND SHORTWAVE TROUGH PUSHES SOUTH AND EAST OF THE AREA.
.SATURDAY THROUGH MONDAY...
MODEL SOLUTIONS VARYING ON HOW THEY HANDLE THE WEEKEND TROUGH THAT
DIGS INTO THE DESERT SOUTHWEST AND EJECTS OUT INTO THE PLAINS OVER
THE WEEKEND. THE PRIMARY DIFFERENCES OCCUR IN REGARD TO HOW A
NORTHERN STREAM SHORTWAVE TROUGH MOVES INTO THE PLAINS IN PROXIMITY
TO THE SHARP TROUGH IN THE SOUTHWEST. THE GFS/ENSEMBLE MEMBERS ARE
TRENDING TOWARDS KEEP THIS TROUGH AHEAD OF THE SOUTHWEST TROUGH
WHICH RESULTS IN A WEAKER AND MORE POSITIVELY TILTED TROUGH ADVANCING
ACROSS THE PLAINS WHILE THE UKMET/GEM/EC CONTINUE MORE IN LINE WITH
PAST SOLNS IN EJECTING THE PRIMARY TROUGH OUT OF THE SOUTHWEST INTO
THE CENTRAL PLAINS. FOR NOW WILL KEEP MORE CONTINUITY WITH WITH
PREVIOUS FCSTS AND LEAN TOWARDS THE EC WHICH STILL BRINGS INCREASING
POTENTIAL FOR SHOWERS AND ISOLATED THUNDERSTORMS SATURDAY AND
ESPECIALLY SATURDAY NIGHT AND SUNDAY BEFORE A DRY SLOT AND COLDER
AIR WORK INTO THE CWA SUNDAY NIGHT WITH A DECREASING POTENTIAL FOR A
RAIN SNOW MIX SUNDAY NIGHT. EITHER WY...PRECIP SHOULD END BY MONDAY
MORNING AS THE SYSTEM LIFTS QUICKLY OFF TO THE NORTHEAST AND DRIER
AIR REMAINS ACROSS THE AREA THROUGH THE DAY. AFTER HIGHS IN THE 40S
AND MIDDLE 50S FOR SATURDAY AND SUNDAY...READINGS COOL INTO THE 40S
FOR HIGHS ON MONDAY. 63
&&
.AVIATION...
TRACKING A BAND OF LOW END MVFR STRATUS SLIDING SOUTH OVER
NORTHEAST KANSAS. THE BAND SHOULD ENTER KMHK FIRST BEFORE ENTERING
KTOP/KFOE SHORTLY NEAR 18Z. CIGS COULD WAVER ON THE LINE BETWEEN
MVFR AND IFR THROUGH THE AFTERNOON. UNCERTAINTY INCREASES IN
DURATION AND SOUTHERN EXTENT OF THIS STRATUS WITH MOST MODELS NOT
IN AGREEMENT WITH THE CURRENT OBSERVATIONS. CONFIDENCE FOR NOW WAS
PLACED WITH THE HRRR WHICH SHOWED THE BEST CONSISTENCY WITH STRONG
COLD ADVECTION ALOFT HOLDING THE MVFR STRATUS THRU 07Z AT KMHK AND
08Z AT KTOP/KFOE. NORTH WINDS AOA 10KTS THROUGH THE PERIOD WILL
BECOME LIGHT AND VARIABLE AFTER 00Z.
BOWEN
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
224 PM MST MON FEB 4 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 1243 PM MST MON FEB 4 2013
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW NW FLOW STILL IN PLACE
FROM BRITISH COLUMBIA ACROSS THE CENTRAL HIGH PLAINS INTO THE
SOUTHERN MISSISSIPPI RIVER VALLEY. LEE TROUGH REMAINS IN PLACE OVER
EASTERN COLORADO WITH ANOTHER WEAK TROUGH AXIS OVER NW KANSAS.
OTHER THAN PASSING HIGH CLOUDS WITHIN NW FLOW TONIGHT...THERE IS
WILL BE VERY LITTLE CHANGE IN EXPECTED CONDITIONS TONIGHT VERSUS
THE LAST FEW NIGHTS...WITH LOWS GENERALLY IN 20S ACROSS THE AREA.
A SHORTWAVE RIDGE WILL BEGIN TO BUILD OVER THE INTER-MOUNTAIN
WEST BY MIDDAY TUESDAY WITHIN PROGRESSIVE FLOW. THERE MAY BE WEAK
FORCING WITHIN THE VICINITY OF THE CWA TUESDAY AFTERNOON AS A
H7-H5 VORT MAX PROGRESSES ACROSS NORTHERN EXTENT OF RIDGE IN
RESPONSE TO A DEEPENING SHORTWAVE TROUGH OVER THE NORTHERN
ROCKIES. HOWEVER...WITH DEEP DRY AIR MASS IN PLACE THIS SHOULD ONLY
RESULT IN INCREASING HIGH CLOUD COVER BY LATE TUESDAY AFTERNOON.
WITH ALL OF THIS IN MIND...I AM ANTICIPATING MILD/DRY CONDITIONS
AGAIN ON TUESDAY WITH HIGHS IN THE MID-UPPER 50S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 223 PM MST MON FEB 4 2013
TUESDAY NIGHT-FRIDAY...SHORT WAVE RIDGE WILL BE IN PLACE ACROSS THE
AREA DURING THE THE BEGINNING OF THE PERIOD LEADING TO CONTINUED DRY
CONDITIONS THROUGH WEDNESDAY. A SHORT WAVE TROUGH WILL MOVE ACROSS
NEBRASKA ON WEDNESDAY...BUT GIVEN STABLE CONDITIONS EXPECTED ACROSS
THE AREA DO NOT EXPECT MUCH OF A RESPONSE ACROSS THE CWA. WHILE
MODELS SUGGEST INCREASE IN ELEVATED INSTABILITY OVERNIGHT WEDNESDAY
ACROSS SOUTHERN AND EASTERN KANSAS...AFOREMENTIONED TROUGH WILL
LIKELY FORCE H85 AND H7 FRONTAL ZONE WELL TO THE SOUTH OF THE AREA
WHICH WOULD MAKE PRECIPITATION DEVELOPING AS FAR NORTH OF THE CWA
UNLIKELY. OTHERWISE ABOVE NORMAL CONDITIONS ARE EXPECTED THROUGH THE
PERIOD.
IN THE EXTENDED(FRIDAY NIGHT-MONDAY)...MAIN CONCERN FOR THE PERIOD
WILL BE THE DEVELOPMENT AND EVOLUTION OF STRONG H5 TROUGH DURING THE
WEEKEND AND ASSOCIATED PRECIP/WINTER STORM IMPACTS THROUGH MONDAY.
THERE ARE TWO DISTINCT CAMPS WITH RESPECT TO 12Z OPERATIONAL AND
ENSEMBLE GUIDANCE. THE ECMWF/GEM AND GEM MEAN INDICATING A FARTHER
EAST MORE CONSOLIDATED SYSTEM IMPACTING THE AREA WHILE GFS AND
MAJORITY OF ITS ENSEMBLE MEMBERS SUGGESTING A FURTHER WEST SYSTEM
THAT IS SOMEWHAT SPLIT BETWEEN THE SOUTHWEST AND NORTHEAST. AT THIS
POINT...HARD TO PICK A FAVORITE CLUSTER WHILE TOTALLY IGNORING OTHER
POSSIBLE SCENARIO. THE ECMWF GROUP WOULD SUPPORT A SIG PRECIP THREAT
ACROSS NORTHERN CWA WHILE GFS SOLUTION WOULD RESULT IN MUCH LESS
PRECIP AND OVERALL SMALLER IMPACT. FOR THE TIME BEING...THINK
KEEPING POPS IN THE CHANCE RANGE IS WARRANTED AND STAYING TOWARDS
CONSENSUS DATA WARRANTED UNTIL BETTER SIGNAL DEVELOPS AND CONFIDENCE
INCREASES. GENERAL CONSENSUS SUGGEST MUCH ABOVE NORMAL TEMPERATURES
AND POSSIBLY A FEW THUNDERSTORMS MAY DEVELOP AHEAD OF SYSTEM BEFORE
SNOW DEVELOPS AS SYSTEM EXITS AND COLDER AIR MOVES IN. WHILE THERE
IS POTENTIAL FOR A SIGNIFICANT WINTER STORM...FOR REASONS MENTIONED
ABOVE FEEL IT IS TOO EARLY TO REALLY KEY IN ON THIS SOLUTION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1031 AM MST MON FEB 4 2013
VFR CONDITIONS WILL PERSIST THROUGH THE TAF PERIOD AT GLD AND MCK. A
FEW HIGH TO MID-LEVEL CLOUDS THIS AFTERNOON AND INTO THE EVENING
FOLLOWED BY MAINLY CLEAR SKIES LATE TONIGHT AND THROUGH TOMORROW.
LIGHT/VARIABLE WINDS WILL PICK UP OUT OF THE WEST TO NORTHWEST LATER
TODAY AND THROUGH THE REST OF THE TAF PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JRM
AVIATION...JJM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1243 PM MST MON FEB 4 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 1243 PM MST MON FEB 4 2013
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW NW FLOW STILL IN PLACE
FROM BRITISH COLUMBIA ACROSS THE CENTRAL HIGH PLAINS INTO THE
SOUTHERN MISSISSIPPI RIVER VALLEY. LEE TROUGH REMAINS IN PLACE OVER
EASTERN COLORADO WITH ANOTHER WEAK TROUGH AXIS OVER NW KANSAS.
OTHER THAN PASSING HIGH CLOUDS WITHIN NW FLOW TONIGHT...THERE IS
WILL BE VERY LITTLE CHANGE IN EXPECTED CONDITIONS TONIGHT VERSUS
THE LAST FEW NIGHTS...WITH LOWS GENERALLY IN 20S ACROSS THE AREA.
A SHORTWAVE RIDGE WILL BEGIN TO BUILD OVER THE INTER-MOUNTAIN
WEST BY MIDDAY TUESDAY WITHIN PROGRESSIVE FLOW. THERE MAY BE WEAK
FORCING WITHIN THE VICINITY OF THE CWA TUESDAY AFTERNOON AS A
H7-H5 VORT MAX PROGRESSES ACROSS NORTHERN EXTENT OF RIDGE IN
RESPONSE TO A DEEPENING SHORTWAVE TROUGH OVER THE NORTHERN
ROCKIES. HOWEVER...WITH DEEP DRY AIR MASS IN PLACE THIS SHOULD ONLY
RESULT IN INCREASING HIGH CLOUD COVER BY LATE TUESDAY AFTERNOON.
WITH ALL OF THIS IN MIND...I AM ANTICIPATING MILD/DRY CONDITIONS
AGAIN ON TUESDAY WITH HIGHS IN THE MID-UPPER 50S.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 1223 AM MST MON FEB 4 2013
SHORTWAVE RIDGING WILL REMAIN IN PLACE FOR THURSDAY AND FRIDAY
LEADING TO DRY CONDITIONS AND ABOVE NORMAL TEMPERATURES. WESTERN
DISTURBANCE WILL BRING A CHANCE FOR RAIN AND SNOW OVER THE
WEEKEND. MODEL RUNS ARE IN EVEN LESS AGREEMENT TONIGHT WITH
DETAILS SUCH AS TRACK...STRENGTH AND TIMING. ECMWF SHOWS A DEEP
CUT OFF LOW DEVELOPING OVER SOUTHWEST KANSAS ON SUNDAY WHICH WOULD
BRING WIND AND SNOW. HOWEVER...THE GFS NEVER DEVELOPS A CUT OFF
INSTEAD SHOWING AN OPEN WAVE AND LITTLE TO NO PRECIPITATION. SOME
POPS ARE PROBABLY WARRANTED...BUT CONFIDENCE IN THE DETAILS IS
VERY VERY LOW AT THIS POINT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1031 AM MST MON FEB 4 2013
VFR CONDITIONS WILL PERSIST THROUGH THE TAF PERIOD AT GLD AND MCK. A
FEW HIGH TO MID-LEVEL CLOUDS THIS AFTERNOON AND INTO THE EVENING
FOLLOWED BY MAINLY CLEAR SKIES LATE TONIGHT AND THROUGH TOMORROW.
LIGHT/VARIABLE WINDS WILL PICK UP OUT OF THE WEST TO NORTHWEST LATER
TODAY AND THROUGH THE REST OF THE TAF PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...024
AVIATION...JJM
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1141 AM CST MON FEB 4 2013
...UPDATE TO AVIATION...
.DISCUSSION...
INVERTED SURFACE TROF BISECTING THE FORECAST AREA THIS
MORNING...WITH COLDER AIR STILL TO THE NORTH AT THIS HOUR. UPPER
WAVE MOVING THROUGH NORTHWEST KANSAS TO THE SOUTHEAST AND WILL SWEEP
COLD FRONT ACROSS THE FORECAST AREA THROUGH THE DAY TODAY.
TEMPERATURES EXPECTED TO STAY WELL MIXED INTO THE 40S FOR THE EAST
CENTRAL COUNTIES UNTIL THIS AFTERNOON WHEN FRONT COMES
THROUGH...WITH NORTH CENTRAL COUNTIES STARTING OFF IN THE LOW TO
MIDDLE 30S BUT DROPPING SLOWLY AS THE DAY GOES ON.
ALSO KEEPING AN EYE ON THE CLOUD DECK MOVING QUICKLY SOUTH OUT OF
SOUTH DAKOTA AND NORTHEAST NEBRASKA. RAP RH CHARTS BRING THIS DECK
INTO THE I70 CORRIDOR AROUND THE NOON HOUR BEFORE BREAKING UP AS IT
MOVES SOUTHWARD. FAR NORTHEAST COUNTIES EXPECTED TO REMAIN THE
COOLEST WITH TEMPERATURES IN THE MIDDLE 30S AND FALLING THIS
AFTERNOON. WINDS BECOME BREEZY FROM THE NORTH FOR A TIME AS THE
FRONT PUSHES THROUGH...BUT THEN WINDS LIGHTEN AND VEER AROUND TO THE
SOUTHWEST BY EARLY MORNING HOURS. OVERNIGHT LOWS SHOULD DROP INTO
THE 20S MOST AREAS AS THE WINDS DIMINISH AND CLOUDS DECREASE.
67
TUESDAY AND WEDNESDAY...ANOTHER WEAK COLD FRONT WILL PUSH THROUGH
TUESDAY AS NORTHWEST FLOW CONTINUES ALOFT. SURFACE HIGH PRESSURE
MOVES RAPIDLY EAST TUESDAY NIGHT ALLOWING WAA TO ONCE AGAIN
RETURN. HOWEVER...WAA NOT STRONG INITIALLY ON WEDNESDAY AFTERNOON
WITH ONLY A MODEST INCREASE IN 850MB TEMPS OF ABOUT 2-3C AND A
3-4DM INCREASE IN HEIGHTS. 925MB-850MB TRANSPORT WINDS WILL BE
AROUND 20-25KTS FROM THE SOUTH/SOUTHEAST...AND WILL ADVECT A
DECENT MOISTURE PLUME NORTH INTO THE CWA AHEAD OF ANOTHER
ADVANCING COLD FRONT FOR WEDNESDAY NIGHT AND INTO THURSDAY
MORNING. WEDNESDAY LOOKS TO BE THE WARMEST DAY OF THE WEEK WITH
HIGHS APPROACHING OR TOPPING 60.
WEDNESDAY NIGHT AND THURSDAY...PW VALUES INCREASE TO AROUND AN
INCH FOR LATE WEDNESDAY NIGHT FOR AREAS MAINLY SOUTH OF INTERSTATE
70. INCREASED POPS AS MODELS COMING INTO AGREEMENT AS FAR AS
PLACEMENT. HOWEVER...MODELS DO DIVERGE ON QPF WITH THE NAM BEING
VERY AGGRESSIVE WITH A BULLS EYE OVER THE SOUTHERN PORTION OF THE
CWA OF AN INCH OF PRECIP. FEEL THIS IS A BIT OVERDONE...AND HAVE
GONE WITH THE MORE CONSISTENT AND CONSERVATIVE QPF VALUES OF THE
ECMWF AND GFS. NAM QUITE AGGRESSIVE ON MUCAPE VALUES AS WELL WITH
UP TO 500 J/KG. MENTIONED ISOLATED THUNDER WEDNESDAY NIGHT SOUTH
OF INTERSTATE 70...BUT FEEL THE NAM INSTABILITY VALUES A BIT
INFLATED. SHEAR PROFILES LOOK TO SUPPORT THUNDER AS WELL WITH
0-6KM VALUES OF AROUND 40KTS. THE SYSTEM SHOULD CLEAR THE CWA BY
18Z. TEMPERATURES WILL BE SLIGHTLY COOLER BEHIND THE FRONT OF
AROUND 10 DEGREES...AND WITH SKIES CLEARING OUT QUICKLY...SHOULD
SEE A RETURN TO 40`S AND 50`S BY THURSDAY AFTERNOON.
EXTENDED...(THURSDAY NIGHT THROUGH THE WEEKEND)...NEXT SYSTEM TO
AFFECT THE REGION WILL BE SATURDAY. QUITE A BIT OF DIVERGENCE IN
THE MODELS AT THIS TIME AS TO THE EVOLUTION OF THE SYSTEM AND ITS
IMPACT ON THE PLAINS. THE GFS ESSENTIALLY HAS THE SYSTEM BECOME
CUTOFF OVER THE DESERT SOUTHWEST AS THE NORTHERN STREAM OF THE
JET PINCHES IT OFF OVER THAT REGION OF THE COUNTRY WITH A FAST
MOVING SHRTWV ACROSS THE NORTHERN PLAINS. THE ECMWF HAS THE SYSTEM
MOVE RAPIDLY OUT OF THE DESERT SOUTHWEST AS A CLOSED H5 LOW RIGHT
ACROSS KANSAS. GIVEN THE EVOLUTION OF SYSTEMS THIS PAST WINTER
SEASON...FEEL THE ECMWF SCENARIO NOT LIKELY. HOWEVER...LOWERED
POPS A BIT SATURDAY TO REFLECT THE DISAGREEMENT IN MODELS. BEHIND
THE SYSTEM...PROFILES LOOK COLD ENOUGH TO BEGIN SUPPORTING SLEET
OR SNOW OVER THE NORTHWEST COUNTIES BY SUNDAY AFTERNOON.
01
&&
.AVIATION...
TRACKING A BAND OF LOW END MVFR STRATUS SLIDING SOUTH OVER
NORTHEAST KANSAS. THE BAND SHOULD ENTER KMHK FIRST BEFORE ENTERING
KTOP/KFOE SHORTLY NEAR 18Z. CIGS COULD WAVER ON THE LINE BETWEEN
MVFR AND IFR THROUGH THE AFTERNOON. UNCERTAINTY INCREASES IN
DURATION AND SOUTHERN EXTENT OF THIS STRATUS WITH MOST MODELS NOT
IN AGREEMENT WITH THE CURRENT OBSERVATIONS. CONFIDENCE FOR NOW WAS
PLACED WITH THE HRRR WHICH SHOWED THE BEST CONSISTENCY WITH STRONG
COLD ADVECTION ALOFT HOLDING THE MVFR STRATUS THRU 07Z AT KMHK AND
08Z AT KTOP/KFOE. NORTH WINDS AOA 10KTS THROUGH THE PERIOD WILL
BECOME LIGHT AND VARIABLE AFTER 00Z.
BOWEN
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
531 AM CST MON FEB 4 2013
...UPDATE TO AVIATION...
.DISCUSSION...
INVERTED SURFACE TROF BISECTING THE FORECAST AREA THIS
MORNING...WITH COLDER AIR STILL TO THE NORTH AT THIS HOUR. UPPER
WAVE MOVING THROUGH NORTHWEST KANSAS TO THE SOUTHEAST AND WILL SWEEP
COLD FRONT ACROSS THE FORECAST AREA THROUGH THE DAY TODAY.
TEMPERATURES EXPECTED TO STAY WELL MIXED INTO THE 40S FOR THE EAST
CENTRAL COUNTIES UNTIL THIS AFTERNOON WHEN FRONT COMES
THROUGH...WITH NORTH CENTRAL COUNTIES STARTING OFF IN THE LOW TO
MIDDLE 30S BUT DROPPING SLOWLY AS THE DAY GOES ON.
ALSO KEEPING AN EYE ON THE CLOUD DECK MOVING QUICKLY SOUTH OUT OF
SOUTH DAKOTA AND NORTHEAST NEBRASKA. RAP RH CHARTS BRING THIS DECK
INTO THE I70 CORRIDOR AROUND THE NOON HOUR BEFORE BREAKING UP AS IT
MOVES SOUTHWARD. FAR NORTHEAST COUNTIES EXPECTED TO REMAIN THE
COOLEST WITH TEMPERATURES IN THE MIDDLE 30S AND FALLING THIS
AFTERNOON. WINDS BECOME BREEZY FROM THE NORTH FOR A TIME AS THE
FRONT PUSHES THROUGH...BUT THEN WINDS LIGHTEN AND VEER AROUND TO THE
SOUTHWEST BY EARLY MORNING HOURS. OVERNIGHT LOWS SHOULD DROP INTO
THE 20S MOST AREAS AS THE WINDS DIMINISH AND CLOUDS DECREASE.
67
TUESDAY AND WEDNESDAY...ANOTHER WEAK COLD FRONT WILL PUSH THROUGH
TUESDAY AS NORTHWEST FLOW CONTINUES ALOFT. SURFACE HIGH PRESSURE
MOVES RAPIDLY EAST TUESDAY NIGHT ALLOWING WAA TO ONCE AGAIN
RETURN. HOWEVER...WAA NOT STRONG INITIALLY ON WEDNESDAY AFTERNOON
WITH ONLY A MODEST INCREASE IN 850MB TEMPS OF ABOUT 2-3C AND A
3-4DM INCREASE IN HEIGHTS. 925MB-850MB TRANSPORT WINDS WILL BE
AROUND 20-25KTS FROM THE SOUTH/SOUTHEAST...AND WILL ADVECT A
DECENT MOISTURE PLUME NORTH INTO THE CWA AHEAD OF ANOTHER
ADVANCING COLD FRONT FOR WEDNESDAY NIGHT AND INTO THURSDAY
MORNING. WEDNESDAY LOOKS TO BE THE WARMEST DAY OF THE WEEK WITH
HIGHS APPROACHING OR TOPPING 60.
WEDNESDAY NIGHT AND THURSDAY...PW VALUES INCREASE TO AROUND AN
INCH FOR LATE WEDNESDAY NIGHT FOR AREAS MAINLY SOUTH OF INTERSTATE
70. INCREASED POPS AS MODELS COMING INTO AGREEMENT AS FAR AS
PLACEMENT. HOWEVER...MODELS DO DIVERGE ON QPF WITH THE NAM BEING
VERY AGGRESSIVE WITH A BULLS EYE OVER THE SOUTHERN PORTION OF THE
CWA OF AN INCH OF PRECIP. FEEL THIS IS A BIT OVERDONE...AND HAVE
GONE WITH THE MORE CONSISTENT AND CONSERVATIVE QPF VALUES OF THE
ECMWF AND GFS. NAM QUITE AGGRESSIVE ON MUCAPE VALUES AS WELL WITH
UP TO 500 J/KG. MENTIONED ISOLATED THUNDER WEDNESDAY NIGHT SOUTH
OF INTERSTATE 70...BUT FEEL THE NAM INSTABILITY VALUES A BIT
INFLATED. SHEAR PROFILES LOOK TO SUPPORT THUNDER AS WELL WITH
0-6KM VALUES OF AROUND 40KTS. THE SYSTEM SHOULD CLEAR THE CWA BY
18Z. TEMPERATURES WILL BE SLIGHTLY COOLER BEHIND THE FRONT OF
AROUND 10 DEGREES...AND WITH SKIES CLEARING OUT QUICKLY...SHOULD
SEE A RETURN TO 40`S AND 50`S BY THURSDAY AFTERNOON.
EXTENDED...(THURSDAY NIGHT THROUGH THE WEEKEND)...NEXT SYSTEM TO
AFFECT THE REGION WILL BE SATURDAY. QUITE A BIT OF DIVERGENCE IN
THE MODELS AT THIS TIME AS TO THE EVOLUTION OF THE SYSTEM AND ITS
IMPACT ON THE PLAINS. THE GFS ESSENTIALLY HAS THE SYSTEM BECOME
CUTOFF OVER THE DESERT SOUTHWEST AS THE NORTHERN STREAM OF THE
JET PINCHES IT OFF OVER THAT REGION OF THE COUNTRY WITH A FAST
MOVING SHRTWV ACROSS THE NORTHERN PLAINS. THE ECMWF HAS THE SYSTEM
MOVE RAPIDLY OUT OF THE DESERT SOUTHWEST AS A CLOSED H5 LOW RIGHT
ACROSS KANSAS. GIVEN THE EVOLUTION OF SYSTEMS THIS PAST WINTER
SEASON...FEEL THE ECMWF SCENARIO NOT LIKELY. HOWEVER...LOWERED
POPS A BIT SATURDAY TO REFLECT THE DISAGREEMENT IN MODELS. BEHIND
THE SYSTEM...PROFILES LOOK COLD ENOUGH TO BEGIN SUPPORTING SLEET
OR SNOW OVER THE NORTHWEST COUNTIES BY SUNDAY AFTERNOON.
01
&&
.AVIATION...
MAINLY A WIND FORECAST THROUGH THE PERIOD. FRONT APPROACHING TAF
SITES AND WILL BRING INCREASING NORTH WINDS INTO THE AFTERNOON.
WILL NEED TO KEEP AN EYE ON MVFR DECK OVER NEBRASKA AS EXPECT WILL
BREAK UP AS IT MOVES SOUTH. WINDS BECOME LIGHT AND VARIABLE LATER
THIS EVENING INTO THE OVERNIGHT HOURS. 67
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
350 AM CST MON FEB 4 2013
.DISCUSSION...
INVERTED SURFACE TROF BISECTING THE FORECAST AREA THIS
MORNING...WITH COLDER AIR STILL TO THE NORTH AT THIS HOUR. UPPER
WAVE MOVING THROUGH NORTHWEST KANSAS TO THE SOUTHEAST AND WILL SWEEP
COLD FRONT ACROSS THE FORECAST AREA THROUGH THE DAY TODAY.
TEMPERATURES EXPECTED TO STAY WELL MIXED INTO THE 40S FOR THE EAST
CENTRAL COUNTIES UNTIL THIS AFTERNOON WHEN FRONT COMES
THROUGH...WITH NORTH CENTRAL COUNTIES STARTING OFF IN THE LOW TO
MIDDLE 30S BUT DROPPING SLOWLY AS THE DAY GOES ON.
ALSO KEEPING AN EYE ON THE CLOUD DECK MOVING QUICKLY SOUTH OUT OF
SOUTH DAKOTA AND NORTHEAST NEBRASKA. RAP RH CHARTS BRING THIS DECK
INTO THE I70 CORRIDOR AROUND THE NOON HOUR BEFORE BREAKING UP AS IT
MOVES SOUTHWARD. FAR NORTHEAST COUNTIES EXPECTED TO REMAIN THE
COOLEST WITH TEMPERATURES IN THE MIDDLE 30S AND FALLING THIS
AFTERNOON. WINDS BECOME BREEZY FROM THE NORTH FOR A TIME AS THE
FRONT PUSHES THROUGH...BUT THEN WINDS LIGHTEN AND VEER AROUND TO THE
SOUTHWEST BY EARLY MORNING HOURS. OVERNIGHT LOWS SHOULD DROP INTO
THE 20S MOST AREAS AS THE WINDS DIMINISH AND CLOUDS DECREASE.
67
TUESDAY AND WEDNESDAY...ANOTHER WEAK COLD FRONT WILL PUSH THROUGH
TUESDAY AS NORTHWEST FLOW CONTINUES ALOFT. SURFACE HIGH PRESSURE
MOVES RAPIDLY EAST TUESDAY NIGHT ALLOWING WAA TO ONCE AGAIN
RETURN. HOWEVER...WAA NOT STRONG INITIALLY ON WEDNESDAY AFTERNOON
WITH ONLY A MODEST INCREASE IN 850MB TEMPS OF ABOUT 2-3C AND A
3-4DM INCREASE IN HEIGHTS. 925MB-850MB TRANSPORT WINDS WILL BE
AROUND 20-25KTS FROM THE SOUTH/SOUTHEAST...AND WILL ADVECT A
DECENT MOISTURE PLUME NORTH INTO THE CWA AHEAD OF ANOTHER
ADVANCING COLD FRONT FOR WEDNESDAY NIGHT AND INTO THURSDAY
MORNING. WEDNESDAY LOOKS TO BE THE WARMEST DAY OF THE WEEK WITH
HIGHS APPROACHING OR TOPPING 60.
WEDNESDAY NIGHT AND THURSDAY...PW VALUES INCREASE TO AROUND AN
INCH FOR LATE WEDNESDAY NIGHT FOR AREAS MAINLY SOUTH OF INTERSTATE
70. INCREASED POPS AS MODELS COMING INTO AGREEMENT AS FAR AS
PLACEMENT. HOWEVER...MODELS DO DIVERGE ON QPF WITH THE NAM BEING
VERY AGGRESSIVE WITH A BULLS EYE OVER THE SOUTHERN PORTION OF THE
CWA OF AN INCH OF PRECIP. FEEL THIS IS A BIT OVERDONE...AND HAVE
GONE WITH THE MORE CONSISTENT AND CONSERVATIVE QPF VALUES OF THE
ECMWF AND GFS. NAM QUITE AGGRESSIVE ON MUCAPE VALUES AS WELL WITH
UP TO 500 J/KG. MENTIONED ISOLATED THUNDER WEDNESDAY NIGHT SOUTH
OF INTERSTATE 70...BUT FEEL THE NAM INSTABILITY VALUES A BIT
INFLATED. SHEAR PROFILES LOOK TO SUPPORT THUNDER AS WELL WITH
0-6KM VALUES OF AROUND 40KTS. THE SYSTEM SHOULD CLEAR THE CWA BY
18Z. TEMPERATURES WILL BE SLIGHTLY COOLER BEHIND THE FRONT OF
AROUND 10 DEGREES...AND WITH SKIES CLEARING OUT QUICKLY...SHOULD
SEE A RETURN TO 40`S AND 50`S BY THURSDAY AFTERNOON.
EXTENDED...(THURSDAY NIGHT THROUGH THE WEEKEND)...NEXT SYSTEM TO
AFFECT THE REGION WILL BE SATURDAY. QUITE A BIT OF DIVERGENCE IN
THE MODELS AT THIS TIME AS TO THE EVOLUTION OF THE SYSTEM AND ITS
IMPACT ON THE PLAINS. THE GFS ESSENTIALLY HAS THE SYSTEM BECOME
CUTOFF OVER THE DESERT SOUTHWEST AS THE NORTHERN STREAM OF THE
JET PINCHES IT OFF OVER THAT REGION OF THE COUNTRY WITH A FAST
MOVING SHRTWV ACROSS THE NORTHERN PLAINS. THE ECMWF HAS THE SYSTEM
MOVE RAPIDLY OUT OF THE DESERT SOUTHWEST AS A CLOSED H5 LOW RIGHT
ACROSS KANSAS. GIVEN THE EVOLUTION OF SYSTEMS THIS PAST WINTER
SEASON...FEEL THE ECMWF SCENARIO NOT LIKELY. HOWEVER...LOWERED
POPS A BIT SATURDAY TO REFLECT THE DISAGREEMENT IN MODELS. BEHIND
THE SYSTEM...PROFILES LOOK COLD ENOUGH TO BEGIN SUPPORTING SLEET
OR SNOW OVER THE NORTHWEST COUNTIES BY SUNDAY AFTERNOON.
01
&&
.AVIATION...
FOR 06Z TAFS...VFR CONDITIONS EXPECTED THROUGH THE PERIOD. A COLD
FRONT WILL TRACK SOUTHEAST THROUGH THE REGION OVERNIGHT...CAUSING
WINDS TO VEER FROM SOUTH TO NORTHWEST THIS MORNING. WINDS ARE
EXPECTED TO BECOME CALM TONIGHT AS A SURFACE HIGH TRACKS OVER
THE REGION. AREAS OF HIGH CLOUDS WILL REMAIN IN PLACE THROUGH MUCH
OF THE PERIOD.
ACH
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
641 PM EST TUE FEB 5 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 400 PM EST TUE FEB 5 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH OVER
HUDSON BAY AND A RIDGE FROM THE ROCKIES TO BC RESULTING IN WNW FLOW
THROUGH THE NRN GREAT LAKES. A SHORTWAVE TROUGH WAS MOVING EASTWARD
THROUGH NRN IL WHILE A WEAKE SHRTWV TO THE NORTH THAT BROUGH THE
LIGHT SNOW TO UPPER MI HAD MOVED INTO NRN LOWER MI. AT THE
SFC...NRLY WINDS WERE INCREASING THROUGH UPPER MI AS A TROUGH MOVES
S THROUGH THE AREA AND A LOW MOVES EAST FROM NEAR THE SAULT. A BAND
OF SNOW SHOWERS SUPPORTED BY LOW LEVEL CONV NEAR THE TROUGH HAS
SAGGED THROUGH THE NORTH PORTION OF THE CWA.
EXPECT MAINLY LIGHT TO MODERATE NW FLOW WIND PARALLEL LES BANDS
TONIGHT. 850 MB TEMPS AROUND -20C WITH MUCH OF THE CLOUD LAYER IN
THE DGZ WILL SUPPORT HIGHER SNOW/WATER RATIOS AOA 25/1.
HOWEVER...VERY DRY AIR UPSTREAM AND INVERSION HEIGHTS AOB 4K FT WILL
ALSO LIMIT LES INTENSITY. SO...SNOWFALL AMOUNTS IN THE 1 TO 3 INCH
RANGE ARE EXPECTED...GREATEST OVER THE EAST. HIGHER RES MODELS
SUGGEST THAT DIMINISHING WINDS LATE TONIGHT MAY ALLOW DEVELOPMENT OF
A MESO-LOW OVER SE LAKE SUPERIOR. THERE IS LOW CONFIDENCE WHER OR IF
THIS WOULD MOVE ASHORE AS WINDS SLOWLY BACK IN RESPONSE TO THE
DEPARTING RIDGE TO THE SOUTH.
THE FCST KEEPS TEMPS TOWARD THE LOWER END OF GUIDANCE INLAND WEST AS
THERE MAY BE ENOUGH OF A PERIOD OF CLEAR TO PARTLY CLOUDY AS MID
CLOUDS PASS FARTHER TO THE NORTH...TO ALLOW TEMPS TO DROP OFF WELL
BELOW ZERO.
UPPER LEVEL DIV ASSOCIATED WITH A DEVELOPING 250-300 MB JET STREAK
FROM THE NRN LAKES TO NEW ENGLAND AND ASSOCIATED MID LEVEL FGEN TO
THE SOUTH INTO NW WI BY LATE TUE AFTERNOON WILLS SUPPORT AN AREA OF
LIGHT SNOW EXPANDING TOWARD UPPER MI. HOWEVER...ONLY CHANCE POPS ARE
EXPECTED INTO THE WEST BY 00Z/THU.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 400 PM EST TUE FEB 5 2013
FIRST FEATURE OF NOTE FOR THIS PERIOD WILL BE THE BROAD WAA AT
THE START OF THE PERIOD AHEAD OF AN INVERTED TROUGH SLIDING
SOUTHEAST THROUGH THE NORTHERN/CENTRAL PLAINS. INITIAL SNOW WILL BE
ONGOING AT THE START OF THE PERIOD OVER WESTERN UPPER
MICHIGAN...WHICH WILL BE LARGELY FOCUSED ALONG THE BROAD H850-600
WAA/ISENTROPIC ASCENT AND RIGHT REAR OF THE UPPER JET MOVING EAST
ACROSS THE CWA. THE BEST/SHARPEST LOW LEVEL WAA GRADIENT DOES LOOK
TO BE FARTHER SOUTH WITH THE 12Z RUNS...MORE IN WISCONSIN...SO
THINKING THAT A FARTHER SOUTH TREND TO THE QPF/SNOW IS WARRANTED.
THAT BEING SAID...THERE ARE SOME HINTS OF THE MID LEVEL FGEN TRYING
TO FOCUS/STALL NEAR SOUTHERN LAKE SUPERIOR...WHICH COULD TRY TO
INCREASE SNOWFALL AMOUNTS SOME.
WITH THE INITIAL WAA SNOW SLIDING EAST ON THURSDAY...A SHORTWAVE IS
EXPECTED TO DROP SOUTHEAST FROM THE NORTHERN PLAINS ON WEDNESDAY
NIGHT INTO THURSDAY. SHORTWAVE LOOKS TO BE A LITTLE STRONGER AND
FARTHER SOUTH THAN YESTERDAY...WHICH HAS SOME INFLUENCE ON THE
OVERALL FORECAST. GFS/ECMWF/GEM SEEM TO BE IN GOOD AGREEMENT WITH
THE TRACK/INTENSITY OF THE SHORTWAVE...WHILE THE NAM IS A LITTLE
FLATTER AND FARTHER NORTH. WILL TREND AWAY FROM THE NAM AND TOWARDS
THE OVERALL CONSENSUS. AS THE SHORTWAVE DIGS THROUGH SOUTHERN WI AND
NORTHERN ILLINOIS...THE LOW BEGINS TO WRAP UP NEAR THE LOWER GREAT
LAKES AND FOCUSES THE BETTER FORCING AND PRECIPITATION FARTHER TO
THE SOUTH ON THURSDAY. BUT...THERE SHOULD STILL BE ENOUGH LINGERING
MOISTURE AND BROAD FORCING TO LEAVE SCATTERED SNOW SHOWERS BEHIND
THE SYSTEM. IN ADDITION...SHOULD SEE SOME LAKE ENHANCEMENT OFF LAKE
SUPERIOR AS H850 TEMPS ARE AROUND -12C AND WINDS ARE OUT OF THE
NORTHEAST DIRECTION. THIS SHOULD CONTINUE INTO THURSDAY EVENING
BEFORE DIMINISHING OVERNIGHT AS THE DEEPER MOISTURE DEPARTS. OFF OF
LAKE MICHIGAN...WINDS LOOK TO BE A LITTLE MORE EASTERLY WEDNESDAY
NIGHT INTO THURSDAY MORNING...WHICH WILL ALSO ASSIST IN SOME
ENHANCEMENT FROM MENOMINEE THROUGH MANISTIQUE. WITH THE RECENT
SHIFTS IN THE FORECAST...THE WIND FIELD HAS BEEN FLUCTUATING GREATLY
WHICH PRODUCES LIMITED CONFIDENCE ON LAKE ENHANCEMENT LOCATIONS.
WITH THE FARTHER SOUTH SHIFT...THINKING MOST LOCATIONS WILL SEE
1-4 INCHES FROM WEDNESDAY AFTERNOON THROUGH THE DAY THURSDAY.
DUE TO IT/S CLOSER PROXIMITY TO BEST LOWER LEVEL WAA AND LAKE
ENHANCEMENT...COULD SEE MENOMINEE COUNTY APPROACHING THE 3 INCHES IN
24HRS ADVISORY CRITERIA WEDNESDAY NIGHT INTO THURSDAY MORNING. WILL
CONTINUE TO MENTION IN THE HWO...BUT WILL FOCUS THE WORDING MORE
TOWARDS THE SOUTH CENTRAL AND AREAS NEAR LAKE MICHIGAN.
ONE FINAL THING TO NOTE FOR THURSDAY IS THE POTENTIAL FOR MID LEVEL
DRY AIR TO ATTEMPT TO CUT OUT SOME OF THE ICE CRYSTALS IN THE
CLOUDS. IF THIS OCCURS...IT COULD LEAD TO BRIEF PERIODS OF FREEZING
DRIZZLE...BUT CONFIDENCE IS EXTREMELY LOW FOR OCCURRING AT THIS
POINT.
HIGH PRESSURE RIDGE THEN MOVES OVER THE AREA FOR LATE THURSDAY
NIGHT INTO FRIDAY NIGHT AND LEADS TO QUIET WEATHER OVER THE CWA.
NEXT WAVE BRUSHES THE NORTHERN HALF OF THE CWA ON SATURDAY AND WILL
CONTINUE TO MENTION SLIGHT OR LOW CHANCE POPS AS THAT PASSES
THROUGH.
UNCERTAINLY IN THE FORECAST GREATLY INCREASES AFTER SATURDAY...AS
MODELS HAVE BEEN DIFFERING ON THE HANDLING OF THE ENERGY EXITING THE
SOUTHWEST CONUS AND MOVING THROUGH THE GREAT LAKES. 00Z ECMWF AND
12Z GFS HAVE COME INTO BETTER AGREEMENT WITH THIS FEATURE
AND PULL A 990S MB LOW THROUGH THE UPPER GREAT LAKES REGION ON
MONDAY INTO MONDAY NIGHT. ENSEMBLE MEMBERS OF BOTH OF THOSE RUNS
VARY GREATLY...WHICH MATCHES UP WELL WITH THE VARIABILITY OVER THE
LAST DAY. WITH 12Z GEM/UKMET ALSO TRENDING TOWARDS A LOW
MOVING THROUGH THE AREA...WILL TREND POPS UP DURING THAT TIME
FRAME TO ADDRESS THE INCREASED POTENTIAL FOR SNOW. IF THE CURRENT
GFS/ECMWF FORECAST IS CORRECT...SOME LOCATIONS IN UPPER MICHIGAN
COULD SEE A HEAVY SNOWFALL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 639 PM EST TUE FEB 5 2013
WESTERN EDGE OF STRATOCU OFF LAKE SUPERIOR IS VERY NEAR KIWD ATTM.
WITH WINDS BACKING...EXPECT MVFR CIGS AT KIWD TO CLEAR OUT OVER THE
NEXT COUPLE OF HRS. VFR CONDITIONS WILL THEN CONTINUE FOR THE
REMAINDER OF THE FCST PERIOD.
AT KCMX...DRY AIR MASS IS CURRENTLY ERODING LAKE EFFECT
CLOUDS/-SHSN. HOWEVER...GIVEN DEGREE OF OVERWATER INSTABILITY AND
NOCTURNAL COOLING ENHANCING CONVERGENCE OVER THE LAKE...EXPECT MVFR
CIGS TO PREVAIL OVERNIGHT ALONG WITH -SHSH/FLURRIES AT TIMES. VFR
MORE LIKELY TO DEVELOP DURING THE MORNING HRS AS LOW-LEVEL WINDS
BECOME LIGHT AND DIVERGENT OVER THE KEWEENAW.
AT KSAW...EXPECT A FEW HRS OF MVFR CONDITIONS WITH -SHSN THIS
EVENING. WHILE MVFR CIGS MAY PERIST THRU THE OVERNIGHT...DRIER AIR
AND BACKING WINDS MAY ALLOW STRATOCU TO SCATTER OUT. VFR CONDITIONS
WILL PREVAIL WED.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 400 PM EST TUE FEB 5 2013
NORTH WINDS TO 30 KNOTS LATE THIS AFTERNOON AND EVENING AND AREAS OF
FREEZING SPRAY WILL GRADUALLY DIMINISH OVERNIGHT AS A RIDGE BUILDS
INTO THE AREA. ENE WINDS INTO THE 15 TO 25 KNOT RANGE ARE ALSO
EXPECTED LATE WED NIGHT INTO THU AS A LOW PRESSURE SYSTEM MOVES
THROUGH SOUTHERN WI. OTHERWISE...WINDS ARE EXPECTED TO REMAIN BELOW
25 KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
423 PM EST MON FEB 4 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 423 PM EST MON FEB 4 2013
LIGHT TO MODERATE SNOW WITH A CLIPPER SYSTEM WILL BE THE MAIN STORY
IN THE SHORT TERM.
LATE THIS AFTERNOON...BACKING WINDS TO A WESTERLY DIRECTION ARE
PUSHING REMAINING LES OFFSHORE ACROSS EASTERN UPPER MI...WITH A FEW
TRANSIENT LES BANDS REMAINING NEAR THE SHORE. HAVE THUS CANCELED THE
LES WARNING...THOUGH A COUPLE MORE INCHES OF SNOW WILL BE POSSIBLE
THROUGH THIS EVENING.
TONIGHT...CLEARING SKIES AND LIGHT WINDS WILL ALLOW FOR QUICK
RADIATIONAL COOLING EARLY THIS EVENING...ESPECIALLY ACROSS CENTRAL
AND EASTERN UPPER MI. LOWERED THE MIN TEMPS GIVEN A SIMILAR SETUP TO
LAST NIGHTS SUBSTANTIAL COOLING.
MAIN FOCUS IS ON A WEAK CLIPPER SYSTEM MOVING SOUTHEAST ACROSS THE
UPPER GREAT LAKES TONIGHT INTO TUESDAY. MODEL AGREEMENT HAS BEEN A
LITTLE FUZZY...WITH THE RUC PLACING THE BULK OF PRECIP IN UPPER
MI...THE NAM AND REGIONAL GEM PUTTING MOST ALONG THE WI BORDER...AND
THE GFS PLACING NEARLY ALL PRECIP IN NORTHERN WI. HAVE OPTED TO GO
WITH THE MIDDLE GROUND AS THE CONSENSUS TREND HAS BEEN TO BRING
THINGS SLIGHTLY NORTH.
PRECIP WILL BE FOCUSED ALONG AN AREA OF 850 TO 700MB FRONTOGENESIS.
THE MOST ACTIVE LAYER IS NOT CLEAR...BUT BELIEVE THE BEST FORCING
WILL BE BETWEEN 750 AND 800MB. A FAIRLY DECENT LAYER OF 150 TO 200MB
WITHIN THE BEST RISING MOTION WILL BE IN THE DGZ. BOOSTED SNOW
RATIOS TO THE LOW 20S GIVEN THIS SET UP. OVERALL...KEPT TOTAL QPF OF
0.1 TO 0.2 INCHES...PRODUCING 1 TO 3 INCHES...WITH UP TO 4 INCHES
POSSIBLE. CURRENT THINKING IS THAT THE HIGHEST AMOUNTS WILL BE ALONG
THE WI BORDER...THOUGH WOULD NOT BE SURPRISED IF IT IS PUSHES 50
MILES EITHER WAY GIVEN THE MODEL INCONSISTENCIES AND NARROW FEATURE.
HAVE ISSUED AN SPS TO COVER THE EVENT AS THERE IS TOO LOW OF
CONFIDENCE TO PUT IN ANY ADVISORIES ATTM. EXPECT SNOW TO BEGIN
ACROSS THE WEST AROUND MIDNIGHT AND SPREAD EAST OVERNIGHT.
THE MAIN SNOW SHIELD WILL DIMINISH THROUGHOUT THE MORNING. THEN...A
WELL DEFINED TROUGH BEHIND THE LOW WILL MOVE SOUTH ACROSS THE
NORTHERN CWA IN THE AFTERNOON. WOULD NOT BE SURPRISED IF A QUICK
BURST OF HEAVY SNOW ACCOMPANIES THIS TROUGH.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 423 PM EST MON FEB 4 2013
NORTHWEST FLOW ALOFT WILL BE IN PLACE FOR THE START OF THE
PERIOD...AS A RIDGE REMAINS IN PLACE OVER THE WESTERN CONUS AND A
TROUGH IS SETUP IN EASTERN CANADA. WITH NORTHWEST FLOW AND H850
TEMPS AROUND -19C...EXPECT SOME LAKE EFFECT SNOW BEHIND THE CLIPPER
SYSTEM THAT MOVES THROUGH ON TUESDAY. THINKING THERE WILL BE ENOUGH
MOISTURE LEFT BEHIND THE CLIPPER TO LEAD TO A BRIEF UPTICK IN THE
LAKE EFFECT INTENSITY DURING THE LATER HALF OF THE EVENING AND INTO
THE FIRST PART OF THE OVERNIGHT HOURS. DON/T EXPECT ANYTHING TOO
SIGNIFICANT DUE TO WEAKENING WINDS WITH THE APPROACHING
SURFACE RIDGE AND INVERSION HEIGHTS IN THE 5-7KFT RANGE...BUT WITH
THE DGZ LOCATED RIGHT IN THE BEST OMEGA AND CLOUD LAYER...WOULD
THINK THAT THE NORTHWEST WIND FAVORED LOCATIONS WOULD SEE A DUSTING
TO A FLUFFY COUPLE OF INCHES OF SNOW.
THE SURFACE RIDGE WILL LEAD TO MORE VARIABLE AND BACKING WINDS
TOWARDS WEDNESDAY MORNING...WHILE THE NEXT CLIPPER SYSTEM
APPROACHES FROM THE DAKOTAS ON WEDNESDAY. THE INCREASING SOUTHERLY
FLOW WILL LEAD TO WARM AIR ADVECTION CLOUDS AND PRECIPITATION
SPREADING ACROSS WEDNESDAY INTO WEDNESDAY NIGHT...WITH THE LOW
MOVING THROUGH THE GREAT LAKES REGION LATE WEDNESDAY NIGHT INTO
THURSDAY. MODELS SEEM FAIRLY CONSISTENT ON THE SHORTWAVE PRODUCING
THIS FEATURE MOVING THROUGH WISCONSIN...ALONG WITH THE BEST/SHARPEST
LOWER LEVEL FORCING. BUT EXPECT THERE TO BE ENOUGH WAA AND MID LEVEL
FGEN TO LEAD SNOW ALONG AND NORTH OF THE WARM FRONT. SEEMS LIKE THE
BEST MID LEVEL FGEN IS FAIRLY PROGRESSIVE ACROSS THE CWA...BUT DOES
TRY TO PIVOT SOMEWHAT ACROSS NORTHERN LAKE SUPERIOR AND NEAR THE
KEWEENAW PENINSULA. WILL BE INTERESTING TO SEE IF THIS PIVOT
CONTINUES AND WHERE IT LINES UP IN FUTURE RUNS...AS IT COULD LEAD TO
SOME INCREASING SNOWFALL AMOUNTS. IN ADDITION...WITH THE SOUTHERLY
LOW LEVEL WIND AND H850 TEMPS AROUND -9C SHOULD BE ENOUGH FOR LAKE
ENHANCEMENT OFF LAKE MICHIGAN. WIND FIELDS VARY FAIRLY SIGNIFICANTLY
IN THE MODELS...SO DIDN/T TRY TO GET TOO SPECIFIC OTHER THAN
TWEAKING POPS/QPF UP SLIGHTLY IN SCHOOLCRAFT/LUCE COUNTIES.
OTHERWISE...OVERALL CONSENSUS OF THE MODELS LOOKS TO PRODUCE
0.15-0.25 INCHES OF QPF...WITH THE HIGHEST AMOUNTS OVER THE
SOUTH/EASTERN CWA. THIS DOES SEEM TO MATCH UP WITH THE NORTH EDGE OF
THE BETTER H850-700 WAA AND RESULTING FGEN...ALONG WITH THE RIGHT
REAR OF THE UPPER JET. THIS PRODUCES A GENERAL 2-4INCHES OF SNOW
ACROSS THE AREA AND WILL CONTINUE TO MENTION IN THE HWO.
BEHIND THE CLIPPER...THERE DOESN/T LOOK TO BE MUCH COLD AIR SURGING
IN DUE TO THE UPPER RIDGE SHIFTING EAST AS AN UPPER TROUGH DIGS
INTO THE WEST COAST. THINKING THIS WILL LEAD TO A QUIETER PERIOD
FOR FRIDAY INTO THE FIRST PART OF SATURDAY AS A HIGH PRESSURE
RIDGE NEAR JAMES BAY STRETCHES SOUTHWEST ACROSS THE UPPER GREAT
LAKES. WITH LIMITED COLD AIR AND WINDS BACKING TO THE
SOUTHWEST...EXPECT A DIMINISHING TREND TO ANY LAKE EFFECT ON
THURSDAY NIGHT AND WILL GO WITH DRY CONDITIONS ON FRIDAY AND FRIDAY
NIGHT.
NEXT SHORTWAVE WILL BRUSH NORTHERN LAKE SUPERIOR ON SATURDAY AND
DRAG A SURFACE TROUGH ACROSS THE CWA. THIS SHOULD LEAD TO A LIGHT
DUSTING OF SNOW...WITH MOST LOCATIONS SEEING LESS THAN AN INCH.
AFTER THIS SYSTEM THE FORECAST BECOMES UNCERTAIN...AS MODELS DIFFER
IN HOW THE ENERGY EJECTS OUT OF THE UPPER TROUGH IN THE SW CONUS.
WILL CONTINUE TO FOLLOW A GENERAL CONSENSUS FOR POPS...WITH THE BEST
CHANCES FOR ACCUMULATING SNOW OVER THE SOUTHEAST HALF OF THE CWA.
AS FOR TEMPS...THE LONG TERM PART OF THE FORECAST LOOKS TO BE AT OR
SLIGHTLY ABOVE NORMAL FOR TEMPERATURES WITH THE COLDEST DAY/NIGHT
ON TUESDAY NIGHT AND WEDNESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1246 PM EST MON FEB 4 2013
LAKE EFFECT SNOW SHOWERS WILL CONTINUE TO WANE THROUGHOUT THE
AFTERNOON AT CMX...WHILE CONDITIONS REMAIN VFR AT IWD INTO THE
EVENING. MEANWHILE...MVFR DIURNAL STRATOCUMULUS HAVE STARTED TO
DEVELOP AT SAW...BUT SHOULD REMAIN MOSTLY SCATTERED.
THE MAIN FOCUS IS ON LOW PRESSURE MOVING ACROSS THE AREA TONIGHT.
FLUFFY...HIGH LIQUID RATIO SNOWFALL IS EXPECTED...MAINLY BETWEEN 06
AND 12Z AT IWD. VIS SHOULD FALL TO LOW END IFR AT IWD FOR SEVERAL
HOURS LATE TONIGHT. AT CMX AND SAW...EXPECT LOW END MVFR VIS AND
CIGS. WINDS WILL BE RELATIVELY LIGHT AS THE SNOW FALLS...SO BLSN IS
NOT A CONCERN. EXPECT WINDS TO TURN MORE OUT THE OF NORTH AT ALL
SITES BY LATE TUESDAY MORNING...LEADING TO FALLING CIGS FROM UPSLOPE
AT SAW AND IWD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 423 PM EST MON FEB 4 2013
EXPECT WEST WINDS OF UNDER 25 KNOTS TO SLOWLY DIMINISH THROUGHOUT
THE NIGHT ACROSS THE EASTERN LAKE. WINDS WILL THEN VEER NORTH TO 20
TO 30 KNOTS BEHIND A TROUGH TUESDAY AFTERNOON INTO TUESDAY EVENING.
OTHERWISE...PLAN ON WINDS UNDER 20 KNOTS THROUGH THE REST OF THE
PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...TK
LONG TERM...SRF
AVIATION...TK
MARINE...TK
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1220 PM EST MON FEB 4 2013
.SYNOPSIS...
ISSUED AT 343 AM EST MON FEB 4 2013
LIGHT SNOW WILL CONTINUE INTO THE AFTERNOON TODAY AS A A CLIPPER
MOVES BY TO THE SOUTH OF THE CWA. AN INCH OR TWO OF ADDITIONAL
ACCUMULATION IS POSSIBLE TODAY BEFORE THE SNOW DIMINISHES. A
STRONGER CLIPPER WILL MOVE ACROSS THE CWA TUESDAY RESULTING IN
ANOTHER 1 TO 4 INCHES OF SNOW. MODERATING TEMPERATURES TOWARD THE
END OF THE WEEK MAY RESULT IN MIXED RAIN AND SNOW OVER THE WEEKEND.
&&
.UPDATE...
ISSUED AT 1109 AM EST MON FEB 4 2013
I HAVE NOW SHORTENED THE LAKE EFFECT SNOW ADVISORY SO IT NOW ENDS
AT 1 PM AS I SUGGESTED I WOULD IN MY PRIOR UPDATE.
UPDATE ISSUED AT 1032 AM EST MON FEB 4 2013
MY CURRENT THINKING IS TO DROP THE LAKE EFFECT SNOW ADVISORY AT 1
PM WITH THE WINTER WEATHER ADVISORY SINCE SURFACE WINDS WILL BE
FROM THE NORTH NORTHEAST... THAT IS NOT SUPPORTIVE OF LAKE EFFECT
SNOW. ALSO THE LATEST RAP MODEL DATA SHOWS LITTLE IF ANY LIFT
ALONG THE LAKE SHORE THIS AFTERNOON AS WELL AS LITTLE IF ANY QPF.
SO ONCE THE SYNOPTIC SYSTEM EXITS IN EARLY THIS AFTERNOON THE SHOW
IS OVER FOR THIS EVENT.
IT LOOKS TO ME LIKE TOMORROW WE WILL HAVE A SW FLOW ENHANCED EVENT
WITH THE NW LAKE SHORE AREAS GETTING THE MOST SNOW. SINCE I DO NOT
WANT HEADLINES FOR TODAY`S EVENT MIXED WITH TOMORROW I PLAN ON
PUTTING THE LAKE EFFECT SNOW ADVISORY (MKG TO LDM ONE ROW OF
COUNTIES) OUT WITH THE 4 PM FORECAST.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 343 AM EST MON FEB 4 2013
FORECAST CONCERNS DEAL WITH SNOW TRENDS TODAY AND TUESDAY.
REGIONAL RADAR SHOWS SNOW FALLING ACROSS THE SRN CWA WNWWD ACROSS
SRN WISCONSIN. ANOTHER INCH OR TWO OF ACCUMULATION IS POSSIBLE AS
THE SYSTEM PASSES BY. LOWEST CONDENSATION PRESSURE DEFICITS ARE
SOUTH OF I-96 TODAY WHICH IS WHERE WE HAVE THE GREATEST
ACCUMULATION. AS THE CLIPPER PASSES BY SNOW WILL TAPER THIS
AFTERNOON. THE SYNOPTIC SNOW IS GETTING A BOOST FROM THE WESTERLY
WIND OFF THE LAKE.
WE MAY SEE A 6 OR 8 HR BREAK FROM SNOW BEFORE THE NEXT CLIPPER
ARRIVES LATE TONIGHT. THE CLIPPER IS PROGD MOVE OVER THE CWA TUESDAY
RESULTING IN A 1-3/2-4 INCH TYPE EVENT. THE LIGHT WINDS EXPECTED
TODAY SHOULD RESULT IN A LOWER IMPACT EVENT. DRY WX EXPECTED
WEDNESDAY AS ZONAL FLOW DEVELOPS IN THE WAKE OF THE CLIPPER.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 343 AM EST MON FEB 4 2013
ZONAL FLOW STILL LOOKS TO BE THE PREDOMINATE UPPER PATTERN TYPE
THROUGH THE LONG TERM PERIOD. MAIN FEATURES TO KEY ON ARE A
SHORTWAVE TROUGH FORECAST TO SWING THROUGH THE GREAT LAKES THURSDAY
AND ANOTHER DEEPER TROUGH CENTERED AROUND SUNDAY. 850MB ARE FORECAST
TO BE BETWEEN -8C AND +4C MUCH OF THE LONG TERM WHICH WILL TAKE LAKE
EFFECT OUT OF PLAY...WHICH WILL BE A CHANGE FROM THE CURRENT AND
RECENT PAST. TEMPERATURES THROUGH THE PERIOD WILL BE NEAR TO ABOVE
NORMAL.
AS FOR THE DETAILS...HAVE A CHANCE OF SNOW MENTIONED WEDNESDAY NIGHT
AHEAD OF A SURFACE TROUGH. HAVE TRENDED POPS TO LIKELY FOR THE BULK
OF THE CWA ON THURSDAY. MAINTAINED A POSSIBLE MIX WITH RAIN IN THE
SOUTH AS 850MB TEMPS TRY TO FLIRT WITH +2C PER THE ECMWF. THE SYSTEM
MOVES EAST THURSDAY NIGHT TAKING THE PRECIPITATION WITH IT. DRY
WEATHER IS ANTICIPATED FOR FRIDAY THROUGH SATURDAY NIGHT AS HIGH
PRESSURE SLIDES THROUGH THE REGION.
THE SUNDAY SYSTEM IS ASSOCIATED WITH UPPER SOUTHWEST FLOW IN PLACE.
THE ECMWF HAS MORE OF A SOUTHERN STREAM LOW EJECTING OUR DIRECTION.
AT THIS POINT HAVE RAIN AND SNOW MENTIONED. IT APPEARS SUNDAY MAY BE
TRENDING TOWARD A COLD RAIN. GIVEN THE TIME FRAME THOUGH...DEEP INTO
THE LONG TERM...WILL MAINTAIN A MIX AS THE ZERO C 850MB ISOTHERM IS
IN THE CWA PER BOTH THE GFS AND THE ECMWF.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY)
ISSUED AT 1220 PM EST MON FEB 4 2013
LIGHT SNOW SHOWERS WILL GRADUALLY TAPER OFF TO FLURRIES BEFORE
ENDING FROM WEST TO EAST THIS AFTERNOON. PREDOMINANTLY IFR/MVFR
CONDITIONS EARLY THIS AFTERNOON WILL TRANSITION TO MAINLY MVFR THEN
VFR THIS EVENING.
THE NEXT CLIPPER SYSTEM WILL BRING SNOW INTO KMKG VERY LATE TONIGHT.
SNOW WILL NOT DEVELOP IN KGRR AND TO THE EAST/SE/SOUTH OF KGRR UNTIL
THE LATE MORNING/EARLY AFTERNOON HOURS TUESDAY. THIS BATCH OF SNOW
WILL CAUSE CONDITIONS TO DETERIORATE BACK INTO THE MVFR THEN IFR
FLIGHT CATEGORY TUESDAY.
&&
.MARINE...
ISSUED AT 343 AM EST MON FEB 4 2013
DISCONTINUED THE SCA AS WINDS AND WAVES ARE LIKELY BELOW CRITERIA.
&&
.HYDROLOGY...
ISSUED AT 343 AM EST MON FEB 4 2013
WARMER WX IS EXPECTED TOWARD THE END OF THE WEEK. THIS MAY
EXACERBATE THE ICE JAM POTENTIAL.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ073-074.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ056-064-071-072.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...93
SHORT TERM...93
LONG TERM...DUKE
AVIATION...LAURENS
HYDROLOGY...93
MARINE...93
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1111 AM EST MON FEB 4 2013
.SYNOPSIS...
ISSUED AT 343 AM EST MON FEB 4 2013
LIGHT SNOW WILL CONTINUE INTO THE AFTERNOON TODAY AS A A CLIPPER
MOVES BY TO THE SOUTH OF THE CWA. AN INCH OR TWO OF ADDITIONAL
ACCUMULATION IS POSSIBLE TODAY BEFORE THE SNOW DIMINISHES. A
STRONGER CLIPPER WILL MOVE ACROSS THE CWA TUESDAY RESULTING IN
ANOTHER 1 TO 4 INCHES OF SNOW. MODERATING TEMPERATURES TOWARD THE
END OF THE WEEK MAY RESULT IN MIXED RAIN AND SNOW OVER THE WEEKEND.
&&
.UPDATE...
ISSUED AT 1109 AM EST MON FEB 4 2013
I HAVE NOW SHORTENED THE LAKE EFFECT SNOW ADVISORY SO IT NOW ENDS
AT 1 PM AS I SUGGESTED I WOULD IN MY PRIOR UPDATE.
UPDATE ISSUED AT 1032 AM EST MON FEB 4 2013
MY CURRENT THINKING IS TO DROP THE LAKE EFFECT SNOW ADVISORY AT 1
PM WITH THE WINTER WEATHER ADVISORY SINCE SURFACE WINDS WILL BE
FROM THE NORTH NORTHEAST... THAT IS NOT SUPPORTIVE OF LAKE EFFECT
SNOW. ALSO THE LATEST RAP MODEL DATA SHOWS LITTLE IF ANY LIFT
ALONG THE LAKE SHORE THIS AFTERNOON AS WELL AS LITTLE IF ANY QPF.
SO ONCE THE SYNOPTIC SYSTEM EXITS IN EARLY THIS AFTERNOON THE SHOW
IS OVER FOR THIS EVENT.
IT LOOKS TO ME LIKE TOMORROW WE WILL HAVE A SW FLOW ENHANCED EVENT
WITH THE NW LAKE SHORE AREAS GETTING THE MOST SNOW. SINCE I DO NOT
WANT HEADLINES FOR TODAY`S EVENT MIXED WITH TOMORROW I PLAN ON
PUTTING THE LAKE EFFECT SNOW ADVISORY (MKG TO LDM ONE ROW OF
COUNTIES) OUT WITH THE 4 PM FORECAST.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 343 AM EST MON FEB 4 2013
FORECAST CONCERNS DEAL WITH SNOW TRENDS TODAY AND TUESDAY.
REGIONAL RADAR SHOWS SNOW FALLING ACROSS THE SRN CWA WNWWD ACROSS
SRN
WISCONSIN. ANOTHER INCH OR TWO OF ACCUMULATION IS POSSIBLE AS THE
SYSTEM PASSES BY. LOWEST CONDENSATION PRESSURE DEFICITS ARE SOUTH OF
I-96 TODAY WHICH IS WHERE WE HAVE THE GREATEST ACCUMULATION. AS THE
CLIPPER PASSES BY SNOW WILL TAPER THIS AFTERNOON. THE SYNOPTIC SNOW
IS GETTING A BOOST FROM THE WESTERLY WIND OFF THE LAKE.
WE MAY SEE A 6 OR 8 HR BREAK FROM SNOW BEFORE THE NEXT CLIPPER
ARRIVES LATE TONIGHT. THE CLIPPER IS PROGD MOVE OVER THE CWA TUESDAY
RESULTING IN A 1-3/2-4 INCH TYPE EVENT. THE LIGHT WINDS EXPECTED
TODAY SHOULD RESULT IN A LOWER IMPACT EVENT. DRY WX EXPECTED
WEDNESDAY AS ZONAL FLOW DEVELOPS IN THE WAKE OF THE CLIPPER.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 343 AM EST MON FEB 4 2013
ZONAL FLOW STILL LOOKS TO BE THE PREDOMINATE UPPER PATTERN TYPE
THROUGH THE LONG TERM PERIOD. MAIN FEATURES TO KEY ON ARE A
SHORTWAVE TROUGH FORECAST TO SWING THROUGH THE GREAT LAKES THURSDAY
AND ANOTHER DEEPER TROUGH CENTERED AROUND SUNDAY. 850MB ARE FORECAST
TO BE BETWEEN -8C AND +4C MUCH OF THE LONG TERM WHICH WILL TAKE LAKE
EFFECT OUT OF PLAY...WHICH WILL BE A CHANGE FROM THE CURRENT AND
RECENT PAST. TEMPERATURES THROUGH THE PERIOD WILL BE NEAR TO ABOVE
NORMAL.
AS FOR THE DETAILS...HAVE A CHANCE OF SNOW MENTIONED WEDNESDAY NIGHT
AHEAD OF A SURFACE TROUGH. HAVE TRENDED POPS TO LIKELY FOR THE BULK
OF THE CWA ON THURSDAY. MAINTAINED A POSSIBLE MIX WITH RAIN IN THE
SOUTH AS 850MB TEMPS TRY TO FLIRT WITH +2C PER THE ECMWF. THE SYSTEM
MOVES EAST THURSDAY NIGHT TAKING THE PRECIPITATION WITH IT. DRY
WEATHER IS ANTICIPATED FOR FRIDAY THROUGH SATURDAY NIGHT AS HIGH
PRESSURE SLIDES THROUGH THE REGION.
THE SUNDAY SYSTEM IS ASSOCIATED WITH UPPER SOUTHWEST FLOW IN PLACE.
THE ECMWF HAS MORE OF A SOUTHERN STREAM LOW EJECTING OUR DIRECTION.
AT THIS POINT HAVE RAIN AND SNOW MENTIONED. IT APPEARS SUNDAY MAY BE
TRENDING TOWARD A COLD RAIN. GIVEN THE TIME FRAME THOUGH...DEEP INTO
THE LONG TERM...WILL MAINTAIN A MIX AS THE ZERO C 850MB ISOTHERM IS
IN THE CWA PER BOTH THE GFS AND THE ECMWF.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 659 AM EST MON FEB 4 2013
A SWATH OF SNOW IS MOVING THROUGH SOUTHWEST LOWER MICHIGAN THIS
MORNING ASSOCIATED WITH A CLIPPER SYSTEM AND ENHANCED BY THE LAKE.
THE WORST OF THE CONDITIONS SHOULD OCCUR IN THE FIRST SEVERAL HOURS
OF THIS TAF CYCLE...12Z TO 16Z. KAZO...KGRR...KBTL AND KJXN WILL
BE THE MOST IMPACTED AS THE SYSTEM SLIDES TO THE SOUTHEAST THROUGH
THE REGION. IFR CONDITIONS WILL BE LIKELY AT THE AFOREMENTIONED
SITES THIS MORNING. AN IMPROVEMENT SHOULD OCCUR FROM WEST TO EAST
DURING THE AFTERNOON HOURS...WITH CONDITIONS LIFTING TO MVFR OR
EVEN VFR. MUCH OF TONIGHT WILL BE QUIET BEFORE THE NEXT QUICK
HITTING CLIPPER MOVES IN TUESDAY MORNING.
&&
.MARINE...
ISSUED AT 343 AM EST MON FEB 4 2013
DISCONTINUED THE SCA AS WINDS AND WAVES ARE LIKELY BELOW CRITERIA.
&&
.HYDROLOGY...
ISSUED AT 343 AM EST MON FEB 4 2013
WARMER WX IS EXPECTED TOWARD THE END OF THE WEEK. THIS MAY
EXACERBATE THE ICE JAM POTENTIAL.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ073-
074.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ056-064-071-072.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...93
SHORT TERM...93
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...93
MARINE...93
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1033 AM EST MON FEB 4 2013
.SYNOPSIS...
ISSUED AT 343 AM EST MON FEB 4 2013
LIGHT SNOW WILL CONTINUE INTO THE AFTERNOON TODAY AS A A CLIPPER
MOVES BY TO THE SOUTH OF THE CWA. AN INCH OR TWO OF ADDITIONAL
ACCUMULATION IS POSSIBLE TODAY BEFORE THE SNOW DIMINISHES. A
STRONGER CLIPPER WILL MOVE ACROSS THE CWA TUESDAY RESULTING IN
ANOTHER 1 TO 4 INCHES OF SNOW. MODERATING TEMPERATURES TOWARD THE
END OF THE WEEK MAY RESULT IN MIXED RAIN AND SNOW OVER THE WEEKEND.
&&
.UPDATE...
ISSUED AT 1032 AM EST MON FEB 4 2013
MY CURRENT THINKING IS TO DROP THE LAKE EFFECT SNOW ADVISORY AT 1
PM WITH THE WINTER WEATHER ADVISORY SINCE SURFACE WINDS WILL BE
FROM THE NORTH NORTHEAST... THAT IS NOT SUPPORTIVE OF LAKE EFFECT
SNOW. ALSO THE LATEST RAP MODEL DATA SHOWS LITTLE IF ANY LIFT
ALONG THE LAKE SHORE THIS AFTERNOON AS WELL AS LITTLE IF ANY QPF.
SO ONCE THE SYNOPTIC SYSTEM EXITS IN EARLY THIS AFTERNOON THE SHOW
IS OVER FOR THIS EVENT.
IT LOOKS TO ME LIKE TOMORROW WE WILL HAVE A SW FLOW ENHANCED EVENT
WITH THE NW LAKE SHORE AREAS GETTING THE MOST SNOW. SINCE I DO NOT
WANT HEADLINES FOR TODAY`S EVENT MIXED WITH TOMORROW I PLAN ON
PUTTING THE LAKE EFFECT SNOW ADVISORY (MKG TO LDM ONE ROW OF
COUNTIES) OUT WITH THE 4 PM FORECAST.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 343 AM EST MON FEB 4 2013
FORECAST CONCERNS DEAL WITH SNOW TRENDS TODAY AND TUESDAY.
REGIONAL RADAR SHOWS SNOW FALLING ACROSS THE SRN CWA WNWWD ACROSS
SRN
WISCONSIN. ANOTHER INCH OR TWO OF ACCUMULATION IS POSSIBLE AS THE
SYSTEM PASSES BY. LOWEST CONDENSATION PRESSURE DEFICITS ARE SOUTH OF
I-96 TODAY WHICH IS WHERE WE HAVE THE GREATEST ACCUMULATION. AS THE
CLIPPER PASSES BY SNOW WILL TAPER THIS AFTERNOON. THE SYNOPTIC SNOW
IS GETTING A BOOST FROM THE WESTERLY WIND OFF THE LAKE.
WE MAY SEE A 6 OR 8 HR BREAK FROM SNOW BEFORE THE NEXT CLIPPER
ARRIVES LATE TONIGHT. THE CLIPPER IS PROGD MOVE OVER THE CWA TUESDAY
RESULTING IN A 1-3/2-4 INCH TYPE EVENT. THE LIGHT WINDS EXPECTED
TODAY SHOULD RESULT IN A LOWER IMPACT EVENT. DRY WX EXPECTED
WEDNESDAY AS ZONAL FLOW DEVELOPS IN THE WAKE OF THE CLIPPER.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 343 AM EST MON FEB 4 2013
ZONAL FLOW STILL LOOKS TO BE THE PREDOMINATE UPPER PATTERN TYPE
THROUGH THE LONG TERM PERIOD. MAIN FEATURES TO KEY ON ARE A
SHORTWAVE TROUGH FORECAST TO SWING THROUGH THE GREAT LAKES THURSDAY
AND ANOTHER DEEPER TROUGH CENTERED AROUND SUNDAY. 850MB ARE FORECAST
TO BE BETWEEN -8C AND +4C MUCH OF THE LONG TERM WHICH WILL TAKE LAKE
EFFECT OUT OF PLAY...WHICH WILL BE A CHANGE FROM THE CURRENT AND
RECENT PAST. TEMPERATURES THROUGH THE PERIOD WILL BE NEAR TO ABOVE
NORMAL.
AS FOR THE DETAILS...HAVE A CHANCE OF SNOW MENTIONED WEDNESDAY NIGHT
AHEAD OF A SURFACE TROUGH. HAVE TRENDED POPS TO LIKELY FOR THE BULK
OF THE CWA ON THURSDAY. MAINTAINED A POSSIBLE MIX WITH RAIN IN THE
SOUTH AS 850MB TEMPS TRY TO FLIRT WITH +2C PER THE ECMWF. THE SYSTEM
MOVES EAST THURSDAY NIGHT TAKING THE PRECIPITATION WITH IT. DRY
WEATHER IS ANTICIPATED FOR FRIDAY THROUGH SATURDAY NIGHT AS HIGH
PRESSURE SLIDES THROUGH THE REGION.
THE SUNDAY SYSTEM IS ASSOCIATED WITH UPPER SOUTHWEST FLOW IN PLACE.
THE ECMWF HAS MORE OF A SOUTHERN STREAM LOW EJECTING OUR DIRECTION.
AT THIS POINT HAVE RAIN AND SNOW MENTIONED. IT APPEARS SUNDAY MAY BE
TRENDING TOWARD A COLD RAIN. GIVEN THE TIME FRAME THOUGH...DEEP INTO
THE LONG TERM...WILL MAINTAIN A MIX AS THE ZERO C 850MB ISOTHERM IS
IN THE CWA PER BOTH THE GFS AND THE ECMWF.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 659 AM EST MON FEB 4 2013
A SWATH OF SNOW IS MOVING THROUGH SOUTHWEST LOWER MICHIGAN THIS
MORNING ASSOCIATED WITH A CLIPPER SYSTEM AND ENHANCED BY THE LAKE.
THE WORST OF THE CONDITIONS SHOULD OCCUR IN THE FIRST SEVERAL HOURS
OF THIS TAF CYCLE...12Z TO 16Z. KAZO...KGRR...KBTL AND KJXN WILL
BE THE MOST IMPACTED AS THE SYSTEM SLIDES TO THE SOUTHEAST THROUGH
THE REGION. IFR CONDITIONS WILL BE LIKELY AT THE AFOREMENTIONED
SITES THIS MORNING. AN IMPROVEMENT SHOULD OCCUR FROM WEST TO EAST
DURING THE AFTERNOON HOURS...WITH CONDITIONS LIFTING TO MVFR OR
EVEN VFR. MUCH OF TONIGHT WILL BE QUIET BEFORE THE NEXT QUICK
HITTING CLIPPER MOVES IN TUESDAY MORNING.
&&
.MARINE...
ISSUED AT 343 AM EST MON FEB 4 2013
DISCONTINUED THE SCA AS WINDS AND WAVES ARE LIKELY BELOW CRITERIA.
&&
.HYDROLOGY...
ISSUED AT 343 AM EST MON FEB 4 2013
WARMER WX IS EXPECTED TOWARD THE END OF THE WEEK. THIS MAY
EXACERBATE THE ICE JAM POTENTIAL.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ073-
074.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ056-
064-071-072.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...93
SHORT TERM...93
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...93
MARINE...93
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1159 PM EST SUN FEB 3 2013
.UPDATE...
ISSUED AT 949 PM EST SUN FEB 3 2013
UPSTREAM 00Z KINL SOUNDING SHOWED THAT RATHER SIGNIFICANT DRYING HAS
OCCURRED SINCE THE 12Z SOUNDING. OVERALL...IT`S NOT AN ENVIRONMENT
REALLY FAVORABLE FOR ANYTHING MUCH MORE THAN LIGHT LES. THIS DRIER
AIR HAS MADE AN IMPACT AS SATELLITE IMAGERY SHOWS A FAIR AMOUNT OF
DISTANCE BTWN THE MN SHORE AND LAKE EFFECT CLOUDS DEVELOPING OVER
THE LAKE. ALSO...WEBCAMS/SPOTTER REPORT FROM MOHAWK AND KCMX OB ALSO
INDICATE ONLY LIGHT LES IS OCCURRING. HAVE THUS CANCELLED THE ADVY
FOR THE WRN COUNTIES WITH ONLY AN INCH...MAYBE 2 OF ADDITIONAL SNOW
OVERNIGHT.
TO THE E...HEAVIER NW FLOW LES CONTINUES. AS IS TYPICAL...WRN MOST
BAND IS BECOMING A MORE DOMINANT BAND DUE TO ENHANCED CONVERGENCE
FROM LAND BREEZE OFF MARQUETTE COUNTY. THIS BAND IS STREAMING INTO
THE MUNISING/WETMORE SHINGLETON AREA. SPOTTER UNDER THIS BAND
REPORTED ABOUT AN INCH/HR SNOWFALL RATE. FARTHER E...ERN MOST BAND
ENHANCED BY CONVERGENCE FROM LAND BREEZE OFF ONTARIO IS STREAMING
INTO ERN WHITEFISH BAY. LATEST HIGH RES MODEL GUIDANCE REMAINS IN
AGREEMENT THAT WITH SOME WEAKENING OF THE GRADIENT WINDS...LAND
BREEZE OFF ONTARIO WILL MAKE SIGNIFICANT WESTWARD PROGRESS
OVERNIGHT...POSSIBLY TO AROUND GRAND MARAIS BY 12Z. THERE SHOULD BE
A HVY SNOW BAND ALONG THAT CONVERGENT ZONE AS IT SHIFTS W. WILL THUS
CONTINUE TO HIGHLIGHT THE AREA FROM MUNISING TO PINE STUMP JUNCTION
FOR HEAVIEST SNOWFALL OVERNIGHT INTO THE MORNING. WITH LAND BREEZE
OFF MARQUETTE COUNTY...A SECONDARY SNOWFALL MAX MAY OCCUR FROM AU
TRAIN/MUNISING AND TO POINTS SE FROM THERE.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 358 PM EST SUN FEB 3 2013
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW PERSISTENT DEEP
UPR TROF OVER E-CNTRL NAMERICA DOWNSTREAM OF HI AMPLITUDE RDG OFF
THE W COAST. A SHRTWV/ATTENDANT LO PRES TROF EMBEDDED IN THIS FLOW
CROSSED UPR MI THIS MRNG...DROPPING AS MUCH AS 3 TO 6 INCHES OF SN
IN AREAS NEAR LK SUP FAVORED FOR MOISTENING/UPSLOPE FLOW IN LLVL
W-NW WINDS. SINCE THE AIRMASS WAS SO DRY WITH PWAT NO MORE THAN
0.05-0.15 INCH...LOCATIONS AWAY FM LK MOISTENING SAW LESS THAN AN
INCH OF SN. IN THE WAKE OF THE TROF PASSAGE...A LLVL NW FLOW BTWN
THE DEPARTING TROF AND A HI PRES RDG MOVING INTO MN AND SHOWN BY THE
MQT VWP IS BRINGING A REINFORCING SHOT OF ARCTIC AIR WITH 12Z H85
TEMPS RANGING FM -20C AT GRB TO -24C AT INL AND -28C AT YPL. DESPITE
THE ABSOLUTE DRYNESS OF THE INCOMING AIRMASS WITH PWATS 0.05 TO 0.10
INCH AND LO INVRN BASE H9-875 SHOWN ON THE 12Z INL/YPL RAOBS...THESE
RAOBS INDICATE THE LOWER LYRS ARE MOIST ENUF IN A RELATIVE SENSE TO
SUSTAIN NMRS WIND PARALLEL LES BANDS SHOWN ON VSBL STLT IMAGERY.
AWAY FM THE NW WIND SN BELTS ESPECIALLY OVER THE SCNTRL WITH
DOWNSLOPE FLOW...DEEP LYR QVECTOR CNVGC/SUBSIDENCE IN THE WAKE OF
DEPARTING SHRTWV ARE CAUSING MOSUNNY CONDITIONS. BUT SFC TEMPS ARE
WELL BLO NORMAL.
TNGT...DEEP LYR QVECTOR DVGC/LARGER SCALE SUBSIDENCE IN THE WAKE OF
DEPARTING SHRTWV ARE FCST TO DOMINATE...AND FCST SDNGS SHOW INVRN
BASE FALLING TO 3-4K FT OVER THE W AND TO ARND 5K FT IN AREAS E OF
MQT. WITH SLOWLY SHIFTING /DIMINISHING NW LLVL FLOW OF ARCTIC AIR
DROPPING H85 TEMPS TO -20C TO -23C...EXPECT NMRS LES BANDS TO IMPACT
AREAS FAVORED BY NW WINDS. LONG FETCH INTO THE ERN CWA WL ALLOW FOR
MODIFICATION OF THE ARCTIC AIR...AND FCST PROFILES SHOW A RELATIVELY
DEEP DGZ WL OCCUPY A GOOD PORTION OF THE CONVECTIVE LYR. IN FACT...
THE 12Z NAM REMAINS QUITE CONSISTENT WITH EARLIER RUNS SHOWING SN/
WATER RATIOS OF 30:1 AT MUNISING THRU TNGT. A GOOD NUMBER OF THE
HIER RES MODELS ALSO INDICATE INCRSG LLVL CNVGC IN THE AREA E OF
MUNISING WITH DVLPMNT OF AN E LAND BREEZE FLOW OFF SE ONTARIO INTO
LUCE COUNTY. THIS COMBINATION OF FAVORABLE FACTORS WARRANTS
CONTINUING THE GOING LES WRNG FOR ALGER/NRN SCHOOLCRAFT/LUCE
COUNTIES. OVER THE W...RELATIVELY SHORT FETCH LENGTH OVER WRN LK SUP
SHORTENED FURTHER BY ICE BUILDUP OFF THE W SHORE WL TEND TO LIMIT
MODERATION OF THIS FRIGID AIRMASS. FCST PROFILES FOR THE WRN CWA
INDICATE THE DGZ OVER THE W WL OCCUPY ONLY THE LOWEST 1K FT OF SO OF
THE ATMOSPHERE. THIS LIMIT ON SN FLAKE SIZE SHOULD HOLD DOWN SN
ACCUMS. THE SOMEWHAT HEAVIER SN MIGHT FALL OVER ONTONAGON COUNTY
WITH MORE PERSISTENT LLVL CNVGC/HINT OF LAND BREEZE FLOW OFF NW WI.
WITH SLOWLY WEAKENING H925 WINDS...DIMINISHING BLSN MIGHT BE ENUF TO
ALLOW EARLY CANX OF LES ADVY OVER THE W AWAY FM ONTONAGON COUNTY.
BUT LEFT GOING ADVY ALONE FOR NOW EVEN THOUGH SN AMNTS MIGHT BE SUB
ADVY DUE TO EFFICIENT NATURE OF FINE SN FLAKES TO LIMIT VSBY.
MON...AS HI PRES RDG AXIS TO THE W SLIDES SLOWLY TO THE E...THE LLVL
FLOW IS PROGGED TO STEADILY BACK TO THE W BY LATE IN THE DAY.
ALTHOUGH H85 TEMPS ARE FCST TO RISE A FEW DEGREES TO -18C TO -21C BY
LATE IN THE DAY...INSTABILITY WL REMAIN MORE THAN SUFFICIENT FOR LES
TO CONTINUE. SLOWLY RISING H85 TEMPS MAY IMPROVE SN GROWTH OVER
THE W... BUT LINGERING LO INVRN BASE AND GENERAL ACYC NATURE OF THE
LLVL FLOW SHOULD ACT TO SUPPRESS THE SHSN INTENSITY. OVER THE E...
ALTHOUGH THE BANDS MIGHT BEGIN TO SHIFT TOWARD THE E...LINGERING
SHARP LLVL CNVGC IN AT LEAST PART OF THIS AREA WARRANTS MAINTAINING
GOING WRNG THRU THE DAY WITH FVRBL SN GROWTH PARAMETERS IN PLACE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 358 PM EST SUN FEB 3 2013
NO BIG CHANGES TO EXPECTED PATTERN SHIFT THAT OCCURS THROUGH THIS
WEEK AS COLD TROUGHING OVER EASTERN CONUS RETREATS INTO CANADA AS
FLOW BECOMES MORE ZONAL LATE THIS WEEK AND TURNS TO SPLIT FLOW
PATTERN BY NEXT WEEKEND. MAIN RESULT IS WARMER TEMPS RETURNING TO
UPR LAKES BY LATE THIS WEEK ALONG WITH A COUPLE CHANCES OF SYSTEM
SNOW ALONG THE WAY.
TO START THE LONG TERM ON MONDAY EVENING...EXPECT LK EFFECT OVER
THE EAST TO GRADUALLY FADE AWAY THROUGH THE NIGHT AS WINDS BACK AND
INVERSIONS CONTINUE TO LOWER. AFTER MIDNIGHT...MAJORITY OF SNOW
SHOWERS WILL BE TO THE EAST OF GRAND MARAIS INTO NORTHERN LUCE
COUNTY. MID CLOUDS AHEAD OF NEXT CLIPPER SYSTEM ALREADY WILL BE
SPILLING ACROSS CWA LATER MONDAY NIGHT WITH SOME SNOW PUSHING INTO
FAR WEST UPR MICHIGAN TOWARD DAYBREAK ON TUESDAY. TEMPS MAY TRY TO
PLUMMET QUICKLY MONDAY EVENING WELL BLO ZERO BEFORE RISING LATER.
COLDEST TEMPS WOULD BE OVER CNTRL AND EASTERN INTERIOR.
CLIPPER SYSTEM ALLUDED TO IS CURRENTLY PUSHING ASHORE OVER NORTHERN
BRITISH COLUMBIA. WAVE IS EXPECTED TO DIG FROM NORTHERN MN ACROSS WI
LATE MONDAY NIGHT THROUGH TUESDAY. THOUGH SFC TROUGH SLIDES SOUTH OF
UPR MICHIGAN...H85 TROUGH CROSSES UPR MICHIGAN THROUGH THE DAY ON
TUESDAY. EXPECT H85 TEMPERATURE AND MOISTURE ADVECTION ALONG WITH
DIVERGENCE ALOFT/H85-H7 FRONTOGENESIS TO SPREAD AREA OF LGT SNOW
ACROSS CWA. MIXING RATIOS LESS THAN 2G/KG AND SHORT DURATION OF
STEADY SNOW WILL LIMIT ACCUMS...BUT THERE IS A POTENTIAL FOR MORE
PERSISTENT FGEN TO RESULT IN A BIT MORE SNOW /2-3 INCHES/ OVER FAR
SCNTRL IMT-MNM-ESC. THIS MATCHES WELL WITH LATEST HPC WINTER WEATHER
GUIDANCE. ECMWF HAS BEEN CONSISTENT IN IMPACTING MOST OF CWA WITH
LGT SNOW. NAM HAS BEEN QUITE INCONSISTENT...PAINTING WIDESPREAD SNOW
OVER ALL CWA YDY AND HARDLY SHOWING ANY QPF WITH 12Z RUN TODAY. WE
HAVE NOTICED RECENTLY OVER LAST FEW WEEKS THAT WITH THESE CLIPPER
SYSTEMS MODELS HAVE HAD TENDENCY TO FORECAST HEAVIER SWATHS OF SNOW
FARTHER SOUTH LEADING UP TO SNOW EVENTS MORE ALONG STRONGER
925-850MB MOISTURE ADVECTION...BEFORE CORRECTING FARTHER TO THE
NORTH RIGHT BEFORE THE EVENT BEGINS. WILL PLAY THAT TREND WITH THIS
FORECAST AND GO WITH FARTHER NORTH ECMWF DEPICTION WITH QPF/SNOW.
12Z GFS HAS TRENDED THIS WAY AS WELL AND ACTUALLY SHOWS SFC LOW A
BIT FARTHER NORTH AS WELL.
AS SFC LOW OR AT LEAST TROUGHING MOVES INTO NORTHERN LOWER MICHIGAN
BY TUESDAY EVENING...WINDS BECOME ONSHORE NEAR LK SUPERIOR. SOME H85
AND EVEN H7 MOISTURE AROUND WITH H85 TEMPS DOWN BLO -13C. WINDS WILL
BE STEADILY BACKING FROM NORTH TO WEST-NORTHWEST THROUGH THE NIGHT.
SCT LK EFFECT SNOW SHOWERS SEEM REASONABLE ALONG LK SUPERIOR. SHOULD
NOT BE BIG DEAL THOUGH AS INVERSIONS QUICKLY LOWER AND WITH PLENTY
OF LOW-LEVEL WIND SHEAR. ISOLD SNOW SHOWERS END QUICKLY ON WEDNESDAY
MORNING ONCE WINDS BECOME MORE SOUTHERLY AHEAD OF NEXT CLIPPER
SYSTEM ENTERING NORTHERN PLAINS.
MODELS HAVE BEEN CONSISTENT IN SHOWING ANOTHER ROUND OF SNOW WITH
THAT CLIPPER AFFECTING UPPER LAKES REGION SOMETIME FROM AS EARLY AS
WEDNESDAY MORNING THROUGH THURSDAY. GEM-NH QUICKEST AS IT HAS
STRONGER H85 LOW OVER NORTHERN MN BY WEDNESDAY AFTN RESULTING IN
MORE MOISTURE AND TEMP ADVECTION AT H85 INTO UPR MICHIGAN. GFS A BIT
SLOWER...FAVORING MOST QPF ON WEDNESDAY NIGHT. ECMWF SLIGHTLY
SLOWER...BUT STILL HAS MAJORITY OF QPF ON WEDNESDAY
NIGHT...ESPECIALLY WEST/CNTRL. SYSTEM IS SIMILAR TO ONE THAT MOVES
THROUGH ON TUESDAY...EXCEPT THIS ONE IS LACKING UPR JET SUPPORT BUT
HAS MORE MOISTURE TO WORK WITH AS H7 MIXING RATIOS ARE 2.5-3.0 G/KG
FLOWING INTO UPR MICHIGAN. 00Z ECMWF WAS FAIRLY WET WITH
QPF...SHOWING OVER 0.4 INCH OVER CNTRL CWA. PREVIOUS RUNS OF ECMWF
AND NEW 12Z RUN NOT AS MOIST...WITH UP TO 0.3 INCH. GFS STAYING ON
THE DRIER SIDE...AROUND 0.15 INCH. SEEMS LIKE IT WILL BE WETTER SNOW
AS H85 TEMPS ARE WARMER THAN -10C AND H7 TEMPS ARE ONLY SLIGHLY
COLDER. COLDER BLYR TEMPS IN TEENS/LOWER 20S PROBABLY ALLOW SLR/S TO
END UP AROUND CLIMO CENTERED ON 15:1. AT FIRST GLANCE...LOW-END ADVY
SNOWS MAY OCCUR OVER PORTIONS OF CWA.
THIS SYSTEM IS STILL OVER NORTHERN PACIFIC WELL TO SOUTH OF ALLUTIAN
ISLANDS. PLENTY OF TIME TO LATCH ONTO SPECIFICS BUT ENOUGH EVIDENCE
PRESENT TO INCREASE POPS TO LIKELY. POPS MAY NEED INCREASING FOR
THURSDAY MORNING OVER THE EAST...BUT JUST KEPT HIGH CHANCE FOR NOW
AS MAJORITY OF SYSTEM SNOW WILL BE FINISHING UP BY THAT TIME. ONCE
LOW SLIDES BY BLYR WINDS BECOME ONSHORE ALONG LK SUPERIOR THU NIGHT
AND THEN BACK OFFSHORE ON FRIDAY. DECREASING MOISTURE AND LACK OF
VERY COLD AIR SHOULD KEEP ANY LK EFFECT LIMITED INTO FRIDAY. OTHER
STORY THURSDAY INTO FRIDAY WILL BE SIGNS THAT WE WILL BE AT LEAST
TEMPORARILY BUSTING OUT OF OUR COLDER WEATHER PATTERN OF LATE WITH
HIGHS BOTH DAYS UPR 20S TO NEAR 30 DEGREES. MODELS HAVE BEEN
INSISTENT THAT COULD SEE SOME SUNSHINE LATER FRIDAY...SO TEMPS MAY
END UP ABOVE FREEZING IN SOME AREAS. SIMILAR TEMPS WILL CONTINUE
INTO THE WEEKEND.
FINALLY...SIGNALS EMERGING IN MODELS/ENSEMBLES THAT AS FLOW BECOMES
SPLIT NEXT WEEKEND...A SOUTHERN STREAM SYSTEM WILL LIFT INTO GREAT
LAKES NEXT SUNDAY INTO MONDAY. STRENGTH OF SYSTEM DEPENDS ON IF
SOUTHERN WAVE BECOMES NEGATIVELY TILTED AND WHETHER ANY PHASING CAN
OCCUR WITH NORTHERN STREAM. FOR WHAT IT IS WORTH...12Z RUNS OF ECMWF
AND GFS SHOW GENEROUS AMOUNTS OF QPF OVER UPPER LAKES LATE NEXT
SUNDAY INTO MONDAY. MAY EVEN BE ENOUGH WARM AIR WRAPPED INTO THE
SYSTEM TO BRING CHANCE OF RAIN/FREEZING RAIN INTO UPR LAKES. DID GO
AHEAD AND MENTION RAIN/SNOW MIX OVER THE SOUTHERN CWA WHICH MATCHES
UP WELL WITH SURROUNDING OFFICES. ELSEWHERE...LOOKS LIKE A WET
SYSTEM SNOW WOULD IMPACT MUCH OF UPR MICHIGAN. A BIT PREMATURE TO
GET TOO HUNG UP ON DETAILS...BUT WILL BE SOMETHING TO WATCH AS WE GO
THROUGH THE UPCOMING WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1158 PM EST SUN FEB 3 2013
AT KCMX...NW FLOW OF ARCTIC AIR WILL CONTINUE TO SUPPORT LAKE
EFFECT SNOW SHOWERS. WITH SMALL FINE SNOWFLAKES DUE TO THE ARCTIC
AIR MASS BEING EFFECTIVE AT REDUCING VIS...IFR CONDITIONS WILL
PROBABLY BE THE RULE THRU THE MORNING. HOWEVER...AS IS TYPICAL OF
LAKE EFFECT SNOW...CONDITIONS MAY BE HIGHLY VARIABLE AT TIMES. AS
WINDS BACK SW THIS EVENING...EXPECT LAKE EFFECT CLOUDS/-SHSN TO END
WITH CONDITIONS BECOMING VFR.
AT KIWD...NW FLOW OVER THE LAKE WILL BE FIGHTING STRENGTHENING LAND
BREEZE OFF NW WI DURING THE NIGHT. AS A RESULT...KIWD WILL BE ON THE
EDGE OF LAKE EFFECT CLOUDS/-SHSN. OPTED TO KEEP MVFR CONDITIONS AT
KIWD THRU THE MORNING BEFORE LARGER SCALE BACKING OF FLOW MAKES
CLEARING MORE LIKELY. THAT SAID...IT`S QUITE POSSIBLE MVFR CIGS
COULD CLEAR OUT AT ANYTIME GIVEN SUCH CLOSE PROXIMITY OF CLEAR SKIES
TO THE W OF KIWD.
AT KSAW...ALTHOUGH PASSING -SHSN/FLURRIES COULD BRING MVFR CIGS AT
TIMES...EXPECT VFR CONDITIONS TO PREVAIL THRU THIS FCST PERIOD WITH
DOWNSLOPING WNW FLOW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 358 PM EST SUN FEB 3 2013
EXPECT PERIODS OF HEAVY FREEZING SPRAY INTO TONIGHT WITH NW WINDS UP
TO 25-30KTS ADVECTING ARCTIC AIR OVER THE WATER. AS THE NW WINDS
DIMINISH LATER TONIGHT WITH APPROACH OF A HI PRES RIDGE...THE HEAVY
FREEZING SPARY WILL GRADUALLY DIMINISH AS WELL. EXPECT WINDS TO STAY
MAINLY BLO 25 KTS THROUGH THE UPCOMING WEEK AS A SERIES OF CLIPPER
LOW PRESSURE TROUGHS MOVE ACROSS. TEMPERATURES WILL GRAUDALLY WARM SO
THERE WILL NOT BE MUCH IN WAY OF FREEZING SPRAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST MONDAY FOR MIZ006-007-
085.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST MONDAY FOR LSZ244-
245-248>251-264>267.
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST /MIDNIGHT CST/
MONDAY FOR LSZ241>243-263.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...ROLFSON
SHORT TERM...KC
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...KC/JLA
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1142 PM EST SUN FEB 3 2013
.SYNOPSIS...
ISSUED AT 335 PM EST SUN FEB 3 2013
A CLIPPER WILL BRING SNOW TO FAR SOUTHERN LOWER MICHIGAN TONIGHT
AS LAKE EFFECT SNOW SHOWERS CONTINUE FOR AREAS NEAR LAKE MICHIGAN.
COLD WEATHER WILL CONTINUE THIS WEEK AND ANOTHER CHANCE OF SNOW
WILL ARRIVE LATE WEDNESDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 335 PM EST SUN FEB 3 2013
CLIPPER WILL BRING SOME SNOW TO THE I-94 CORRIDOR LATE TONIGHT AND
MONDAY MORNING. LATEST HRRR AND 12Z MODEL GUIDANCE SUGGEST HEAVIER
STRIPE OF F-GEN SNOWS WILL MISS OUR FORECAST AREA TO THE SOUTH BUT
EXPECT AT LEAST A COUPLE INCHES ACROSS SOUTHERN CALHOUN AND
JACKSON COUNTIES...JUST ENOUGH TO IMPACT THE MONDAY MORNING COMMUTE.
WENT WITH A WINTER WEATHER ADVISORY FOR JACKSON AND CALHOUN SINCE
THIS WILL BE A SYNOPTIC EVENT...WHILE CONTINUING THE LAKE EFFECT
SNOW ADVISORY FOR WESTERN COUNTIES DUE TO LAKE ACCUMS THERE TODAY
AND TONIGHT.
THE CLIPPER MOVES EAST WEDNESDAY AFTERNOON WITH JUST SOME RATHER
LIGHT LAKE EFFECT SNOW SHOWERS LEFT IN ITS WAKE. THE YET ANOTHER
CLIPPER APPROACHES IN FAST NW FLOW FOR TUESDAY AFTERNOON AND
EVENING. THE SFC LOW MOVES NORTH OF THE FORECAST AREA BUT SOME
CONVERGENCE AND LAKE ENHANCEMENT EXPECTED TO DROP MORE SNOW ACROSS
THE NORTHWEST FORECAST AREA...PERHAPS ENOUGH FOR AN ADVISORY.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 335 PM EST SUN FEB 3 2013
SEASONABLE TEMPS ARE ANTICIPATED WEDNESDAY BEFORE TEMPS MODERATE
SLIGHTLY LATE IN THE WEEK AND FOR NEXT WEEKEND. DRY CONDITIONS ARE
ANTICIPATED WEDNESDAY WITH A HIGH PRESSURE RIDGE IN CONTROL BEFORE A
LOW PRESSURE SYSTEM BRINGS A CHC OF SNOW LATE WEDNESDAY NIGHT. A MIX
OF RAIN AND SNOW IS POSSIBLE FOR THURSDAY.
A HIGH PRESSURE RIDGE WILL BRING DRY WX FRIDAY INTO SATURDAY BEFORE
THE NEXT LOW PRESSURE SYSTEM BRINGS ANOTHER CHC FOR MIXED PCPN LATE
NEXT WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1138 PM EST SUN FEB 3 2013
THE NEXT WAVE OF LOW PRESSURE IS MOVING INTO THE AREA FROM THE
WEST AT THIS TIME. WE ARE SEEING SOME OF THE SNOW INCREASING.
CONDITIONS ARE EXPECTED TO DETERIORATE THROUGH 10Z WITH WIDESPREAD
IFR OR LOWER CONDITIONS PREDICTED. THE TRACK OF THE STORM FAVORS
SOUTHERN TAF SITES LIKE KAZO...KBTL AND KJXN FOR THE LOWEST
CONDITIONS. BY 18Z...THE SYSTEM WILL BE PULLING AWAY AND A RETURN
TO MVFR OR BETTER IS FORECASTED.
&&
.MARINE...
ISSUED AT 335 PM EST SUN FEB 3 2013
ICE WILL CONTINUE TO ACCUMULATE ON THE LAKES AND CHANNELS THE NEXT
COUPLE DAYS. EXPECT THE WAVES AND WINDS TO DECREASE ENOUGH ON
MONDAY TO LET THE SCA EXPIRE.
&&
.HYDROLOGY...
ISSUED AT 335 PM EST SUN FEB 3 2013
COLD WEATHER WILL HOLD ON MUCH OF THIS WEEK. A THAW IS EXPECTED
NEXT WEEKEND. LOOKING FURTHER AHEAD...BY MONDAY LOW PRESSURE
TAKING A TRACK ACROSS NORTHERN MICHIGAN COULD BRING ENOUGH RAIN
AND SNOW MELT TO CAUSE ANOTHER ROUND OF PROBLEMS WITH ICE BREAKUP
ON THE RIVERS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST MONDAY FOR MIZ056-064-
071-072.
WINTER WEATHER ADVISORY FROM 4 AM TO 1 PM EST MONDAY FOR MIZ073-
074.
LM...SMALL CRAFT ADVISORY UNTIL 7 AM EST MONDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...OSTUNO
SHORT TERM...OSTUNO
LONG TERM...LAURENS
AVIATION...MJS
HYDROLOGY...OSTUNO
MARINE...OSTUNO
AREA FORECAST DISCUSSION
NWS HASTINGS NE
408 PM CST MON FEB 4 2013
.SHORT TERM...TONIGHT AND TUESDAY.
WE REMAIN IN NORTHWEST FLOW ALOFT FOR THE SHORT TERM. A SURFACE COLD
FRONT THAT PASSED TO THE SOUTHWEST EDGE OF THE CWA TODAY HAS STALLED
AND BEGUN TO MOVE BACK TO THE EAST. EARLIER STRATUS BEHIND THE COLD
FRONT IS CONTINUING TO ERODE...WITH MAINLY THE EASTERN CWA THE ONLY
AREA LEFT WITH APPRECIABLE STRATUS.
MODELS HAVE NOT BEEN HANDLING THE STRATUS WELL AND THE ONLY MODEL TO
LATCH ON TO IT WELL THIS MORNING WAS THE HRRR. THE STRATUS IS
BURNING OFF ON THE WESTERN EDGE FASTER THAN THE HRRR INDICATES.
ALSO...THE HRRR INDICATES A WESTWARD PUSH THIS EVENING BEFORE
SCOURING OUT FOR GOOD AS THE WARM FRONT/TROUGH MOVES EAST. SINCE THE
HRRR IS LOSING ITS GRIP ON THE SITUATION...I AM BANKING ON THE
CONTINUED EASTWARD PROGRESSION OF THE WESTERN EDGE OF THE STRATUS.
MODELS DO NOT INDICATE ANY REDUCED VISIBILITY ALONG THE WESTERN EDGE
OF THE STRATUS TONIGHT...EXCEPT THE HRRR...BUT THE HRRR ALSO
INDICATED REDUCED VISIBILITY THIS MORNING ALONG THE WESTERN EDGE OF
THE STRATUS AND THIS DID NOT COME TO FRUITION...SO I AM DISCARDING
THIS SOLUTION...AS WIND WILL BECOME WEST AND INCREASE IN STRENGTH
SOMEWHAT AS WELL.
NUDGED TEMPERATURES UP A BIT FOR TONIGHT WITH A SLIGHT INCREASE TO
WIND SPEED BEHIND THE WARM FRONT.
STILL BANKING ON A WARMER DAY WITH INCREASED 850 MB TEMPERATURES FOR
TUESDAY...WITH PLENTY OF SUN. WIND GUSTS COULD INCREASE A BIT FROM
INCREASED LAPSE RATES...BUT NOTHING THAT WOULD BE CONSIDERED
PARTICULARLY OUT OF THE ORDINARY FOR CENTRAL NEBRASKA.
.LONG TERM...TUESDAY EVENING THROUGH NEXT MONDAY. CERTAINLY THE
MOST INTRIGUING ASPECT OF THIS 6-DAY PERIOD IS THE POTENTIALLY/
REPEAT POTENTIALLY/ IMPACTFUL SYSTEM IN THE SATURDAY-SUNDAY NIGHT
TIME FRAME...AND WHETHER IT RESULTS IN ACCUMULATING SNOW AND/OR
EVEN SOME THUNDERSTORMS. HOWEVER...GIVEN THE CONSIDERABLE
UNCERTAINTY AT THIS DAY 5-6 RANGE...WILL NOT GET TOO CARRIED AWAY
AT THIS TIME. IN THE NEARER PERIODS...WILL HAVE TO WATCH FAR
SOUTHEAST COUNTIES FOR A POSSIBLE GLANCING BLOW OF SHOWERS/WEAK
THUNDERSTORMS WEDNESDAY NIGHT. OTHERWISE...AT LEAST FOR THE
WEDNESDAY-SATURDAY TIME FRAME...CONFIDENCE IS FAIRLY HIGH IN A
MILD TEMPERATURE REGIME WITH HIGHS GENERALLY AVERAGING UPPER 40S-
MID 50S.
STARTING OFF TUESDAY NIGHT...SHOULD BE BE A QUIET PERIOD. 12Z
MODELS SUCH AS THE NAM/GFS/ECMWF ARE IN GOOD AGREEMENT DEPICTING
QUASI-ZONAL FLOW ALOFT/WEAK SHORTWAVE RIDGING. AT THE
SURFACE...INITIALLY LIGHT/VARIABLE BREEZES WILL GRADUALLY BECOME
STEADIER AND FROM THE SOUTH...INCREASING TO AT LEAST 10-15 MPH IN
MANY AREAS AFTER MIDNIGHT AS A SURFACE RIDGE MIGRATES EAST AND A
LOW LEVEL JET DEVELOPING OVERHEAD PROVIDES A BIT OF MIXING. THIS
SETUP SHOULD KEEP TEMPS FROM DROPPING VERY FAR...AND MADE LITTLE
CHANGE TO PREVIOUS FORECAST WITH MID-UPPER 20S ALL AREAS. BOTH THE
SREF/NAM VISIBILITY PRODUCTS HINT AT SOME FOG POTENTIAL NEAR THE
EASTERN EDGE OF THE CWA DURING THE NIGHT...BUT WILL LEAVE OUT OF
THE FORECAST AS BELIEVE THE INCREASING BREEZES SHOULD KEEP ANY
FOG FROM AMOUNTING TO MUCH...EVEN IF IT WOULD TRY FORMING.
WEDNESDAY/WEDNESDAY NIGHT...THE PICTURE ALOFT INVOLVES THE CENTRAL
PLAINS REMAINING UNDER QUASI-ZONAL FLOW...AS A PROGRESSIVE...SLOWLY
AMPLIFYING SHORTWAVE TROUGH DRIFTS OUT OF THE NORTHERN ROCKIES
TOWARD THE NORTHERN NEB/IA REGION. AHEAD OF THIS WAVE...A
MILD...DRY AND SOMEWHAT BREEZY DAY IS ANTICIPATED...AS SUSTAINED
SOUTHWEST WINDS 15-20 MPH WITH HIGHER GUSTS PICK UP AHEAD OF AN
ADVANCING SURFACE TROUGH. THESE WIND SPEEDS ARE ROUGHLY 5 MPH
HIGHER THAN PREVIOUS FORECAST. GIVEN THIS GOOD MIXING REGIME AND
SKIES AVERAGING NO WORSE THAN PARTLY CLOUDY...LOOKING AT A
SEASONABLY WARM DAY AND PER SUGGESTION OF VARIOUS MODELS HAVE
RAISED HIGHS 2-3 DEGREES MOST AREAS...PUTTING MOST PLACES
GENERALLY 55-59. PER THE 18Z NAM...SOME WESTERN AREAS COULD EVEN
TOP 60...BUT KEPT THE VAST MAJORITY OF THE AREA BELOW 60 FOR NOW.
BY WED EVENING...THE MAIN SHORTWAVE AXIS ALOFT WILL ENTER THE
LOCAL AREA...WHILE IN THE LOW LEVELS EVIDENT FROM 850MB TO THE
SURFACE...A MODEST COLD FRONT WILL PASS THROUGH. AS THIS LOW LEVEL
BOUNDARY ENCOUNTERS INCREASING MOISTURE...VARIOUS MODELS ARE
CONSISTENT IN BREAKING OUT A CORRIDOR OF RAIN SHOWERS/EMBEDDED
WEAK THUNDERSTORMS ACROSS MUCH OF SOUTHERN/EASTERN KANSAS. WHILE
THE 18Z NAM/12Z GEM KEEP THIS ACTIVITY AT LEAST SLIGHTLY SOUTHEAST
OF OUR CWA...THE LATEST ECWMF/GFS RUNS AT LEAST BRUSH OUR FAR
SOUTHEAST COUNTIES AROUND BELOIT KS. CONTEMPLATED ADDING A SLIGHT
CHANCE OF SHOWERS IN THIS FAR SOUTHEAST AREA...BUT GIVEN THIS IS
STILL 5 FORECAST PERIODS AWAY WILL MAINTAIN OUR PREVIOUSLY DRY
FORECAST AND LET THE NEXT FEW SHIFTS MONITOR THE TRENDS FOR
POSSIBLE INTRODUCTION OF RAIN CHANCES.
THURSDAY/THURSDAY NIGHT...CONFIDENCE IS FAIRLY HIGH IN A DRY 24
HOURS...AS FAIRLY UNEVENTFUL QUASI-ZONAL FLOW IS PRESENT ALOFT
BEHIND THE SHORTWAVE TROUGH FROM WED NIGHT THAT DEPARTS EASTWARD
ACROSS IA DURING THE DAY...AND A MORE SIGNIFICANT SYSTEM JUST
STARTING TO ORGANIZE OVER THE WESTERN CONUS. LOW LEVEL TEMPS WILL
BE A BIT COOLER THAN WED...AND BREEZES WILL BE LIGHTER...WHICH
SHOULD RESULT IN A SLIGHTLY COOLER BUT STILL PLEASANT DAY. MADE
LITTLE CHANGE TO HIGH TEMPS...WITH LOW 50S MOST AREAS.
FRIDAY/FRIDAY NIGHT...THINGS START TO TURN MORE INTERESTING
ALOFT...AS THERE IS FAIRLY GOOD AGREEMENT AMONGST THE 12Z
ECMWF/GFS/GEM THAT A CLOSED 500MB LOW WILL DEVELOP OVER THE DESERT
SOUTHWEST AND BECOME CENTERED NEAR THE NV/AZ/UT BORDER AREA BY
SUNRISE SATURDAY MORNING. CONFIDENCE REMAIN QUITE HIGH IN A DRY
DAYTIME PERIOD AS FORCING REMAINS WELL SOUTHWEST OF THE LOCAL
AREA...WHILE AT THE SURFACE SOUTH BREEZES AVERAGE AT LEAST 15-20
MPH...WITH CURRENT FORECAST SPEEDS POSSIBLE NOT HIGH ENOUGH.
NUDGED UP HIGH TEMPS VERY SLIGHTLY...GETTING ALL BUT FAR EASTERN
COUNTIES TO AT LEAST 50 DEGREES. BY FRIDAY NIGHT...THE GFS SUGGESTS
THAT LOW LEVEL MOISTURE COULD INCREASE ENOUGH FOR POSSIBLE DRIZZLE
DEVELOPMENT...BUT WITH THIS BEING SEVERAL DAYS AWAY AND LIKELY NOT
A MEASURABLE PRECIP RISK...WILL LEAVE OUT ANY MENTION.
AS ALREADY MENTIONED...THE 36-HOUR TIME FRAME BETWEEN SATURDAY AND
SUNDAY NIGHT HOLDS PLENTY OF POTENTIAL TO BE VERY INTERESTING IN
SEVERAL POSSIBLE WAYS INCLUDING ACCUMULATING SNOW...THUNDERSTORMS
AND STRONG GRADIENT WINDS THAT COULD RESULT IN BLOWING SNOW.
HOWEVER...THERE IS STILL A WHOLE LOT TO HAMMER OUT STILL BEING 5-6
DAYS AWAY...SO FOR NOW HAVE ONLY INTRODUCED SOME STANDARD
ACCUMULATING SNOW POSSIBLE/UNCERTAINTY HIGH WORDING INTO THE
HAZARDOUS WEATHER OUTLOOK...AND HAVE REFRAINED FROM INTRODUCING
THUNDERSTORMS YET. IN SHORT...THE 12Z ECMWF/GEM ARE IN PRETTY GOOD
AGREEMENT MAINTAINING THIS SYSTEM AS A COMPACT...POWERFUL CLOSED
LOW THAT COULD HAVE SOME LOCAL IMPACTS...WHILE THE GFS DEPICTS A
MUCH MORE ELONGATED/LESS-FOCUSED UPPER SYSTEM WITH AT MOST ONLY A
MINOR/NUISANCE WINTRY SIDE. HAVE CAPPED POPS AT 50 PERCENT RANGE
FOR NOW...AS ITS STILL TOO EARLY TO SAY ANYTHING IS 60+ PERCENT
LIKELY AT ANY GIVEN SPOT. FOCUSING ON WHAT CONFIDENCE IS
RELATIVELY HIGH IN...ANY PRECIP THAT BREAKS OUT DAYTIME SATURDAY
SHOULD STAY IN LIQUID/SHOWERY FORM. THEN SATURDAY NIGHT...THE
ECWMF/GEM SOLUTIONS AGREE ON A FAIRLY VERTICALLY STACKED...STRONG
LOW PRESSURE SYSTEM CENTERED ALONG THE KS/CO BORDER BY SUNRISE
SUNDAY MORNING...ALTHOUGH THE ECMWF KEEPS WARMER AIR ALOFT IN
PLACE THROUGH THE NIGHT INSTEAD OF CHANGING OVER TO SNOW IN
NORTHWEST COUNTIES. AS A RESULT...HAVE MOVED THE RAIN/SNOW
TRANSITION LINE FARTHER NORTHWEST COMPARED TO PREVIOUS FORECAST.
THEN FOR SUNDAY/SUNDAY NIGHT...TH LATEST ECWMF SOLUTION TAKES THE
TRACK OF THE MID LEVEL CLOSED LOW DIRECTLY OVER THE HEART OF THE
CWA...WHICH WOULD IN THEORY FOCUS THE BEST ACCUMULATING SNOW
POTENTIAL ACROSS OUR NORTHWEST 1/2...AND MAYBE KEEP SHOWERS/STORMS
GOING IN SOUTHEAST AREAS DURING THE DAY BEFORE COLDER AIR FILTERS
IN DURING THE EVENING. PLENTY OF CHANGES ARE LIKELY IN THE DETAILS
OVER THE COMING DAYS...AND WANT TO EMPHASIZE THAT ITS STILL TOO
EARLY TO GET OVERLY CONCERNED.
GETTING BEYOND THIS POTENTIAL WEATHER-MAKER INTO MONDAY...EVEN THE
SLOWER ECMWF SOLUTION PULLS ALL PRECIP RISK AT LEAST SLIGHTLY EAST
OF THE CWA...SO WILL ADVERTISE A DRY DAY. CONFIDENCE IN HIGH TEMPS
IS QUITE LOW DEPENDING ON HOW THE WEEKEND SHAKES OUT...SO SIMPLY
WENT WITH ALLBLEND MODEL SOLUTION OF MID 30S MOST NEB ZONES...AND
NEAR 40 IN KS.
&&
.PREV DISCUSSION... /ISSUED 1200 PM CST MON FEB 4 2013/
AVIATION...18Z KGRI TAF. STRATUS WILL BE THE MOST DIFFICULT
COMPONENT TO DEAL WITH. MVFR STRATUS HAS SPREAD INTO THE AREA
BEHIND A COLD FRONT MOVING IN FROM THE NORTHEAST...BUT THE EDGE HAS
STALLED ABOUT 30 MILES WEST OF THE TERMINAL. MODELS ARE NOT
HANDLING THE EDGE OF THE STRATUS WELL...EXCEPT FOR THE HRRR MODEL
WHICH IS HANDLING THE INITIALIZATION OF THE STRATUS WELL. THIS
MODEL KEEPS US SOCKED IN THE STRATUS ALL DAY...AND WITH A SURGE
BACK TO THE WEST PREDICTED...THE STRATUS COULD HOLD FIRM WELL INTO
THE NIGHT. SOME BRIEF FOG COULD BE POSSIBLE ON THE WESTERN EDGE OF
THE STRATUS BEFORE THE WIND STARTS PICKING FROM THE WEST...BUT
CHANCES LOOK UNLIKELY AT THIS TIME. CONFIDENCE WITH SKY COVER
BECOME LOW BY THIS EVENING INTO THE OVERNIGHT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM/AVIATION...HEINLEIN
LONG TERM...PFANNKUCH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1200 PM CST MON FEB 4 2013
.AVIATION...18Z KGRI TAF. STRATUS WILL BE THE MOST DIFFICULT
COMPONENT TO DEAL WITH. MVFR STRATUS HAS SPREAD INTO THE AREA
BEHIND A COLD FRONT MOVING IN FROM THE NORTHEAST...BUT THE EDGE HAS
STALLED ABOUT 30 MILES WEST OF THE TERMINAL. MODELS ARE NOT
HANDLING THE EDGE OF THE STRATUS WELL...EXCEPT FOR THE HRRR MODEL
WHICH IS HANDLING THE INITIALIZATION OF THE STRATUS WELL. THIS
MODEL KEEPS US SOCKED IN THE STRATUS ALL DAY...AND WITH A SURGE
BACK TO THE WEST PREDICTED...THE STRATUS COULD HOLD FIRM WELL INTO
THE NIGHT. SOME BRIEF FOG COULD BE POSSIBLE ON THE WESTERN EDGE OF
THE STRATUS BEFORE THE WIND STARTS PICKING FROM THE WEST...BUT
CHANCES LOOK UNLIKELY AT THIS TIME. CONFIDENCE WITH SKY COVER
BECOME LOW BY THIS EVENING INTO THE OVERNIGHT.
&&
.PREV DISCUSSION... /ISSUED 1131 AM CST MON FEB 4 2013/
DISCUSSION...UPDATING THE FORECAST FOR TODAY INTO TONIGHT DUE TO
THE SIGNIFICANT AMOUNT OF STRATUS BEHIND A COLD FRONT MOVING IN
FROM THE NORTHEAST TODAY. MODELS ARE GENERALLY NOT PICKING UP ON
THIS WELL...EXCEPT FOR THE HRRR. THEREFORE...FOLLOWING MORE
CLOSELY TO THE HRRR FOR SKY COVER TODAY AND TONIGHT...WITH THE
WESTERN/SOUTHWESTERN EDGE OF THE CWA STAYING IN THE SUN FOR THE
MOST PART. THIS WILL LEAD TO A WIDE RANGE OF TEMPERATURES TODAY.
UNDER THE STRATUS...IT APPEARS THAT LOWER TO MID 30S WILL BE THE
WAY TO GO...WITH LOWER TO MID 50S FOR HIGHS IN THE FAR WEST WHERE
THE SUN WILL PREVAIL. THIS IS A DRAMATIC SHIFT COOLER WHERE THE
STRATUS IS NOW FORECAST COMPARED TO THE FORECAST EARLIER THIS
MORNING...BY ABOUT 10 TO 15 DEGREES.
PREV DISCUSSION... /ISSUED 334 AM CST MON FEB 4 2013/
SHORT TERM...TODAY THROUGH 12Z THURSDAY. MAIN FORECAST CONCERN WILL
BE TEMPERATURES.
SURFACE ANALYSIS SHOWS A LOW PRESSURE SYSTEM AND COLD FRONT MOVING
THROUGH THE AREA EARLY THIS MORNING. IT WILL BE THROUGH THE FORECAST
AREA BY MORNING. OBSERVATIONS SHOW THAT THERE IS NOT MUCH COLD AIR
BEHIND THE FRONT.
A COOL SURFACE HIGH PRESSURE SYSTEM SETTLES INTO THE AREA TODAY.
TEMPERATURES WILL BE COOLER THAN YESTERDAY. LOWER CLOUDS FROM THE
DAKOTAS SHOULD BREAK UP A LITTLE AS THEY MOVE TO THE SOUTH BUT
EXPECT SOME TO MOVE INTO THE NORTH AND ESPECIALLY INTO THE NORTHEAST
TODAY. THIS WILL KEEP THAT AREA A BIT COOLER. EVEN THOUGH IT IS
COOLER...TEMPERATURES WILL BE ABOVE NORMAL. THE COOL SURFACE HIGH
PRESSURE SYSTEM MOVES TO THE EAST TONIGHT AND WINDS TURN TOWARD THE
WEST. THERE IS NOT MUCH WARM ADVECTION BUT THE DOWN SLOPING ASPECT
OF THE WINDS WILL KEEP TEMPERATURES FROM FALLING OFF TOO MUCH
TONIGHT.
ON TUESDAY THERE WILL BE MORE SUNSHINE AND A LITTLE WARM ADVECTION.
TEMPERATURES WILL WARM BACK UP A LITTLE. THE WARMING TREND CONTINUES
INTO TUESDAY NIGHT WITH TEMPERATURES A LITTLE WARMER. AN UPPER LEVEL
WAVE MOVES INTO THE AREA ON WEDNESDAY AND A COLD FRONT MOVES THROUGH
THE FORECAST AREA DURING THE AFTERNOON. SINCE MOST OF THE AREA WILL
HAVE SOME WARM ADVECTION MOST OF THE DAY EXPECT TEMPERATURES TO BE A
BIT WARMER ON WEDNESDAY. AFTER THE FRONT MOVES THROUGH THE AREA THE
UPPER WAVE GETS SOME SHOWERS TO DEVELOP ALONG THE FRONT. BY THE TIME
THESE GET STARTED...THE FRONT SHOULD BE FAR ENOUGH TO THE SOUTHEAST
THAT IT WOULD BE OUT OF THE AREA. HAVE CONTINUED THE DRY FORECAST
FOR WEDNESDAY NIGHT.
LONG TERM...THURSDAY THROUGH SUNDAY...CHANGES APPEAR TO BE ON THE
HORIZON OVER THE UPCOMING WEEKEND AS A POTENT UPPER LEVEL LOW
PRESSURE SYSTEM BEGINS TO SPREAD ITS INFLUENCE ACROSS THE LOCAL AREA
BY SATURDAY.
SHORT WAVE RIDGING WILL BE IN PLACE ACROSS THE PLAINS TO START THE
EXTENDED PERIODS AS AN UPPER LEVEL LOW PROGRESSES DOWN THE WEST
COAST AND ANOTHER UPPER LEVEL DISTURBANCE WORKS ITS WAY ACROSS THE
GREAT LAKES REGION. AS A RESULT...DRY CONDITIONS AND UNSEASONABLY
WARM TEMPERATURES ARE EXPECTED FOR THE END OF THE WORK WEEK...WITH
AFTERNOON TEMPERATURES BOTH THURSDAY AND FRIDAY EXPECTED TO CLIMB 10
OR SO DEGREES ABOVE SEASONAL NORMS. THEREAFTER...THINGS BEGIN TO GET
MUCH MORE INTERESTING AS MODEL CONSENSUS CONTINUES TO INDICATE THERE
WILL BE A POTENT UPPER LEVEL LOW PRESSURE SYSTEM ACROSS THE DESERT
SOUTHWEST. WITH MANY OF THE GFS ENSEMBLE MEMBERS AS WELL AS EC
CUTTING OFF THIS LOW AT 500 MB AND SLOWING ITS EJECTION INTO THE
PLAINS...WENT AHEAD AND DISCOUNTED THE OPERATIONAL GFS A BIT...AND
KEPT THE FRIDAY NIGHT PERIOD DRY.
WHILE MOISTURE IS EXPECTED TO BEGIN SPILLING INTO THE PLAINS ON
SATURDAY...CONFIDENCE OF PRECIPITATION BEGINNING DURING THE DAYTIME
HOURS SATURDAY IS A BIT SHAKY...AND PREFER EC SOLUTION WHICH KEEPS
AREA DRY FOR THE DAYTIME HOURS...BUT KEPT WITH THE ALL BLEND CHANCE
POPS DURING THE DAY FOR NOW AS THERE IS ENOUGH UNCERTAINTY IN TIMING
TO JUSTIFY THIS. IF PRECIP DOES DEVELOP DURING THE DAY ON
SATURDAY...EXPECT IT TO FALL AS ALL RAIN IN LINE WITH MODELED
SOUNDINGS...WITH ANY CHANCE OF THUNDERSTORMS REMAINING WELL TO THE
SOUTH OF THE AREA AS CAPE IS VIRTUALLY NON EXISTENT ACROSS THE LOCAL
AREA.
SATURDAY NIGHT INTO SUNDAY...THINGS GET MORE INTERESTING DEPENDING
ON WHICH MODEL SOLUTION YOU TRUST...BUT TEMPS ALOFT WILL BEGIN TO
COOL AND EXPECT A TRANSITION OF RAIN SHOWERS TO LIGHT SNOW DURING THE
OVERNIGHT HOURS...WITH ACCUMULATING SNOWFALL A POSSIBILITY NEXT
SUNDAY. HOWEVER...AS MENTIONED IN PREVIOUS DISCUSSION...MUCH
UNCERTAINTY REMAINS IN ACTUAL TIMING AND PRECIP TOTALS THIS FAR
OUT...BUT ALL SIGNS DO AT LEAST POINT TO A CHANGE IN THE GENERAL
WEATHER PATTERN BY NEXT WEEKEND.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AVIATION/DISCUSSION (UPDATE)...HEINLEIN
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1131 AM CST MON FEB 4 2013
.DISCUSSION...UPDATING THE FORECAST FOR TODAY INTO TONIGHT DUE TO
THE SIGNIFICANT AMOUNT OF STRATUS BEHIND A COLD FRONT MOVING IN
FROM THE NORTHEAST TODAY. MODELS ARE GENERALLY NOT PICKING UP ON
THIS WELL...EXCEPT FOR THE HRRR. THEREFORE...FOLLOWING MORE
CLOSELY TO THE HRRR FOR SKY COVER TODAY AND TONIGHT...WITH THE
WESTERN/SOUTHWESTERN EDGE OF THE CWA STAYING IN THE SUN FOR THE
MOST PART. THIS WILL LEAD TO A WIDE RANGE OF TEMPERATURES TODAY.
UNDER THE STRATUS...IT APPEARS THAT LOWER TO MID 30S WILL BE THE
WAY TO GO...WITH LOWER TO MID 50S FOR HIGHS IN THE FAR WEST WHERE
THE SUN WILL PREVAIL. THIS IS A DRAMATIC SHIFT COOLER WHERE THE
STRATUS IS NOW FORECAST COMPARED TO THE FORECAST EARLIER THIS
MORNING...BY ABOUT 10 TO 15 DEGREES.
&&
.PREV DISCUSSION... /ISSUED 542 AM CST MON FEB 4 2013/
AVIATION...12Z KGRI TAF...AN EXPANSIVE DECK OF MVFR STRATUS
ASSOCIATED WITH AN ARCTIC FRONT TO THE NORTHEAST IS RAPIDLY
APPROACHING THE TERMINAL THIS MORNING. WHILE LATEST GUIDANCE DOES
NOT INDICATE THIS STATUS DECK WILL REACH KGRI...CANNOT IGNORE
SATELLITE IMAGERY WHICH HAS THE STRATUS PROJECTED TO REACH KGRI
BETWEEN 12Z AND 13Z. THIS STRATUS WILL SLOWLY PULL EAST WITH THE
ARCTIC FRONT BY EARLY AFTERNOON...AND HAVE PREVAILING VFR
CONDITIONS RETURNING AFT 19Z. WINDS TODAY WILL BE OUT OF THE NORTH
NEAR 10 KTS...BECOMING LIGHT AND VARIABLE BY AFTERNOON...BEFORE
SWITCHING SOUTHERLY OVERNIGHT IN RETURN FLOW AROUND SURFACE HIGH
SLIDING BY TO THE EAST.
PREV DISCUSSION... /ISSUED 334 AM CST MON FEB 4 2013/
SHORT TERM...TODAY THROUGH 12Z THURSDAY. MAIN FORECAST CONCERN WILL
BE TEMPERATURES.
SURFACE ANALYSIS SHOWS A LOW PRESSURE SYSTEM AND COLD FRONT MOVING
THROUGH THE AREA EARLY THIS MORNING. IT WILL BE THROUGH THE FORECAST
AREA BY MORNING. OBSERVATIONS SHOW THAT THERE IS NOT MUCH COLD AIR
BEHIND THE FRONT.
A COOL SURFACE HIGH PRESSURE SYSTEM SETTLES INTO THE AREA TODAY.
TEMPERATURES WILL BE COOLER THAN YESTERDAY. LOWER CLOUDS FROM THE
DAKOTAS SHOULD BREAK UP A LITTLE AS THEY MOVE TO THE SOUTH BUT
EXPECT SOME TO MOVE INTO THE NORTH AND ESPECIALLY INTO THE NORTHEAST
TODAY. THIS WILL KEEP THAT AREA A BIT COOLER. EVEN THOUGH IT IS
COOLER...TEMPERATURES WILL BE ABOVE NORMAL. THE COOL SURFACE HIGH
PRESSURE SYSTEM MOVES TO THE EAST TONIGHT AND WINDS TURN TOWARD THE
WEST. THERE IS NOT MUCH WARM ADVECTION BUT THE DOWN SLOPING ASPECT
OF THE WINDS WILL KEEP TEMPERATURES FROM FALLING OFF TOO MUCH
TONIGHT.
ON TUESDAY THERE WILL BE MORE SUNSHINE AND A LITTLE WARM ADVECTION.
TEMPERATURES WILL WARM BACK UP A LITTLE. THE WARMING TREND CONTINUES
INTO TUESDAY NIGHT WITH TEMPERATURES A LITTLE WARMER. AN UPPER LEVEL
WAVE MOVES INTO THE AREA ON WEDNESDAY AND A COLD FRONT MOVES THROUGH
THE FORECAST AREA DURING THE AFTERNOON. SINCE MOST OF THE AREA WILL
HAVE SOME WARM ADVECTION MOST OF THE DAY EXPECT TEMPERATURES TO BE A
BIT WARMER ON WEDNESDAY. AFTER THE FRONT MOVES THROUGH THE AREA THE
UPPER WAVE GETS SOME SHOWERS TO DEVELOP ALONG THE FRONT. BY THE TIME
THESE GET STARTED...THE FRONT SHOULD BE FAR ENOUGH TO THE SOUTHEAST
THAT IT WOULD BE OUT OF THE AREA. HAVE CONTINUED THE DRY FORECAST
FOR WEDNESDAY NIGHT.
LONG TERM...THURSDAY THROUGH SUNDAY...CHANGES APPEAR TO BE ON THE
HORIZON OVER THE UPCOMING WEEKEND AS A POTENT UPPER LEVEL LOW
PRESSURE SYSTEM BEGINS TO SPREAD ITS INFLUENCE ACROSS THE LOCAL AREA
BY SATURDAY.
SHORT WAVE RIDGING WILL BE IN PLACE ACROSS THE PLAINS TO START THE
EXTENDED PERIODS AS AN UPPER LEVEL LOW PROGRESSES DOWN THE WEST
COAST AND ANOTHER UPPER LEVEL DISTURBANCE WORKS ITS WAY ACROSS THE
GREAT LAKES REGION. AS A RESULT...DRY CONDITIONS AND UNSEASONABLY
WARM TEMPERATURES ARE EXPECTED FOR THE END OF THE WORK WEEK...WITH
AFTERNOON TEMPERATURES BOTH THURSDAY AND FRIDAY EXPECTED TO CLIMB 10
OR SO DEGREES ABOVE SEASONAL NORMS. THEREAFTER...THINGS BEGIN TO GET
MUCH MORE INTERESTING AS MODEL CONSENSUS CONTINUES TO INDICATE THERE
WILL BE A POTENT UPPER LEVEL LOW PRESSURE SYSTEM ACROSS THE DESERT
SOUTHWEST. WITH MANY OF THE GFS ENSEMBLE MEMBERS AS WELL AS EC
CUTTING OFF THIS LOW AT 500 MB AND SLOWING ITS EJECTION INTO THE
PLAINS...WENT AHEAD AND DISCOUNTED THE OPERATIONAL GFS A BIT...AND
KEPT THE FRIDAY NIGHT PERIOD DRY.
WHILE MOISTURE IS EXPECTED TO BEGIN SPILLING INTO THE PLAINS ON
SATURDAY...CONFIDENCE OF PRECIPITATION BEGINNING DURING THE DAYTIME
HOURS SATURDAY IS A BIT SHAKY...AND PREFER EC SOLUTION WHICH KEEPS
AREA DRY FOR THE DAYTIME HOURS...BUT KEPT WITH THE ALL BLEND CHANCE
POPS DURING THE DAY FOR NOW AS THERE IS ENOUGH UNCERTAINTY IN TIMING
TO JUSTIFY THIS. IF PRECIP DOES DEVELOP DURING THE DAY ON
SATURDAY...EXPECT IT TO FALL AS ALL RAIN IN LINE WITH MODELED
SOUNDINGS...WITH ANY CHANCE OF THUNDERSTORMS REMAINING WELL TO THE
SOUTH OF THE AREA AS CAPE IS VIRTUALLY NON EXISTENT ACROSS THE LOCAL
AREA.
SATURDAY NIGHT INTO SUNDAY...THINGS GET MORE INTERESTING DEPENDING
ON WHICH MODEL SOLUTION YOU TRUST...BUT TEMPS ALOFT WILL BEGIN TO
COOL AND EXPECT A TRANSITION OF RAIN SHOWERS TO LIGHT SNOW DURING THE
OVERNIGHT HOURS...WITH ACCUMULATING SNOWFALL A POSSIBILITY NEXT
SUNDAY. HOWEVER...AS MENTIONED IN PREVIOUS DISCUSSION...MUCH
UNCERTAINTY REMAINS IN ACTUAL TIMING AND PRECIP TOTALS THIS FAR
OUT...BUT ALL SIGNS DO AT LEAST POINT TO A CHANGE IN THE GENERAL
WEATHER PATTERN BY NEXT WEEKEND.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
DISCUSSION (UPDATE)...HEINLEIN
AREA FORECAST DISCUSSION
NWS NORMAN OK
1049 PM CST SUN FEB 3 2013
.AVIATION...
04/06Z TAFS...VFR CONDITIONS EXPECTED TO PREVAIL. LLWS WILL BE
INCLUDED FROM KSPS/KLAW UP THROUGH KOKC AND KPNC OVERNIGHT WITH
40-45KT LOW-LEVEL JET IN PLACE. COLD FRONT WILL MOVE OVER
TERMINALS 12Z TO 18Z SHIFTING WINDS TO NORTHERLY. STILL LOOKS LIKE
MOST OF SHOWER ACTIVITY WILL BE EAST OF TERMINALS AND WILL NOT BE
INCLUDED.
&&
.PREV DISCUSSION... /ISSUED 951 PM CST SUN FEB 3 2013/
UPDATE...
VERY MIXED SIGNALS FROM THE NUMERIC MODELS ABOUT PRECIPITATION
POTENTIAL OVERNIGHT. LOCAL WRF DEVELOPS WIDESPREAD LIGHT
PRECIPITATION... HRRR DOES AS WELL LATE... BUT OTHERS KEEP IT DRY.
WOULD NOT BE SURPRISED TO SEE RADAR ECHOES INCREASE OVERNIGHT BUT
00Z RAOB SHOWS A DEEP LAYER OF DRY AIR BELOW 475 MB SO WOULD
EXPECT MOSTLY VIRGA. SURFACE OBS ACROSS THE SOUTHERN PLAINS DO NOT
SHOW SIGNIFICANT INCREASE IN SURFACE DEWPOINTS POISED TO MOVE IN
EITHER. WILL KEEP POPS AS THEY ARE WITH THE RELATIVELY LOW POPS IN
EAST. MADE SOME ADJUSTMENTS TO THE HOURLY GRIDS BUT THESE WILL NOT
REQUIRE UPDATING THE TEXT PRODUCTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 45 59 31 62 / 20 30 0 0
HOBART OK 46 61 29 63 / 20 20 0 0
WICHITA FALLS TX 48 64 36 64 / 20 30 0 0
GAGE OK 37 57 22 61 / 10 10 0 0
PONCA CITY OK 42 57 24 60 / 20 20 0 0
DURANT OK 49 59 39 64 / 30 70 10 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
26/99/11
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
707 AM EST MON FEB 4 2013
.SYNOPSIS...
A DEEP 500 HPA TROUGH OVER EASTERN NORTH AMERICA WILL SLOWLY
WEAKEN AND LIFT OUT AS THE WEEK PROGRESSES. AT LEAST TWO CLIPPER
LIKE WAVES WILL MOVE ACROSS OUR AREA MONDAY AND TUESDAY...AS THIS
HAPPENS. BY THE END OF THE WEEK THE TROUGH AND LOW-LEVEL COLD AIR WILL
BE REPLACED BY A RIDGE AND GENERALLY WARMER AIR. THIS IMPLIES A
GENERAL WARMING TREND AS THE WEEK PROGRESSES AS 850 HPA
TEMPERATURES SHOULD BE ABOUT 1 STANDARD DEVIATION ABOVE NORMAL BY
THE WEEKEND.
&&
.NEAR TERM /UNTIL 10 AM THIS MORNING/...
RADAR STILL SHOWS NARROW BANDS OF LIGHT SNOW OVER CENTRAL PA WHICH
DO NOT EXTEND MUCH BEYOND THE RIDGE VALLEY SYSTEM. NO REPORTS OF
ANY SIGNIFICANT SNOWS. BEST SNOW AREAS APPEAR JUST NORTH OF NY/PA
BORDER AND SW MTS WERE OBSERVATIONS AND RADAR SHOWED MORE
CONSISTENT SNOWS. SATELLITE IMAGERY SEEMS TO SHOW THE CLOUDS
COVERING MOSTLY WESTERN HALF TO ABOUT TWO THIRDS OF THE STATE. HAS
BEEN MOSTLY CLEAR IN SOME OF SOUTHEASTERN AREAS.
THE CIRRUS WITH THE APPROACHING CLIPPER HAS MOVED OVER MOST OF
OHIO AND SHOULD BE IN PA WITHIN HOURS. AFTERNOON SNOW IS GETTING CLOSER.
TEMPERATURES MAINLY IN THE TEENS AND TWENTIES ACROSS THE REGION
THIS MORNING WITH STEADY WEST WINDS. SHOULD SEE SLOW RISE IN TEMPS
THIS AM AND STEADILY INCREASING CLOUDS...THOUGH MOSTLY CLOUDY IN
WEST WITH ALL THE LOW CLOUDS.
&&
.SHORT TERM /10 AM THIS MORNING THROUGH 6 PM TUESDAY/...
THE CLOUDS FROM THE CLIPPER ARE CLEARLY ZIPPING ACROSS OHIO THIS
MORNING AND HEADED OUR WAY FAST. TIMING LOOKS GOOD AND CONSISTENT
WITH RAP AND 06Z NAM CLOSE TO PREVIOUS FORECASTS OF 03Z SREF.
EXPECT SNOW TO ARRIVE AN HOUR OF ABOUT 2 PM IN THE WEST.
ONLY RUB IS THE 06Z NAM IMPLIES THERE COULD BE SOME SPOTTY 0.4 TO
0.50 INCH QPF VALUES IN EXTREME SW PA. A FEW HIGHER ELEVATIONS
SITES WITH 16 TO 20:1 RATIOS COULD SEE OVER 6 INCHES OF SNOW.
THOUGH MOST LOCATIONS SHOULD BE IN THE MORE GENERAL 3-5 RANGE. SO
DID NOT PUT UP A WINTER STORM WARNING FOR WHAT MIGHT BE HEAVY SNOW
ON HIGHER RIDGES OF SOMERSET COUNTY. BUT THERE COULD BE SOME
ISOLATED AMOUNTS AROUND OR JUST OVER 6 INCHES.
PREVIOUS DISCUSSION STILL VALID:
THE LATEST HIGH RESOLUTION MODELS ALL IMPLY A BRIEF PERIOD OF PERHAPS
MODERATE SNOW IN THE SW AREAS NEAR THE MD BORDER. THE 03Z SREF TOO
SUPPORTS THIS CONCEPT WITH SNOW ARRIVING A FEW HOURS EITHER SIDE
OF ABOUT 2 PM IN WESTERN PA. THE SREF IMPLIES 0.1 TO 0.20 INCHES
OF QPF IN SW MOUNTAINS WHICH WOULD BE A GOOD 4-5 INCHES OF VERY
FLUFFY SNOW. THE SREF MEAN IMPLIES ISOLATED 0.30 AREAS FOR STORM
TOTALS IN SOMERSET COUNTY. THE AXIS OF HIGHEST POPS AND HIGHEST
QPFS RUN ALONG THE PA/MD BORDER AND SOUTH. THOUGH BEST QPF IN OUR
AREA ARE IN SW MTS.
INDICATIONS ARE MOST OF THE SYNOPTIC SNOWS WILL END QUICKLY
BETWEEN 10 PM AND 1 AM TONIGHT. SHOWED SNOW AMOUNTS RAPIDLY
LOWERING TO NORTH WITH EVENT AND SNOW:WATER RATIOS IN THE 16 TO
20:1 RANGE.
SREF IS NOT OPTIMISTIC WITH THE 3-5 INCHES IN NW AREAS BUT THIS
COULD BE A MODEL RESOLUTION ISSUE AND DID NOT MESS WITH THIS TOO
MUCH UNTIL WE SEE NEWER GUIDANCE.
STRONG WESTERLY WIND MAXIMUM MOVES OVER SOUTHERN TIER MONDAY
AFTERNOON SO WE COULD BRING DOWN GUSTS IN 15 TO 20 MPH RANGE.
THE WINTER WEATHER ADVISORY FOR THE LAURELS TO 06Z TUESDAY AND
ISSUED A LAKE EFFECT SNOW ADVISORY FOR THE NW MTNS FROM 00Z MONDAY
TO 06Z TUESDAY.
THE NEXT WAVE SHOULD NOT ARRIVE UNTIL TUESDAY AFTERNOON OR EVENING
WITH ANOTHER SHOT AT SOME ACCUMULATING SNOWS OF 1-2 INCHES IN
NORTHERN TIER OF MORE FLUFFY SNOWS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE SECOND CLIPPER WILL BRING SNOW (SEE ABOVE) TO THE REGION
MAINLY LATE TUESDAY AFTERNOON INTO TUESDAY NIGHT. BEST CHANCE OF
1-2 INCHES OF SNOW SHOULD BE ACROSS NORTHERN AREAS.
PREVIOUS DISCUSSION...THE LARGER SCALE PATTERN TUESDAY THROUGH
SUNDAY SHOWS THE TROUGH OVER THE EAST WEAKENING AND LIFTING OUT.
BY THE WEEKEND THE 500 HPA HEIGHTS SHOULD BE SLIGHTLY ABOVE NORMAL
AS WELL AS THE 850 HPA TEMPERATURES. NORTHERN STREAM SHORT-WAVES
COULD BRING PRECIPITATION TUESDAY INTO EARLY
WEDNESDAY...FRIDAY...AND SUNDAY INTO MONDAY. SOME HINTS ARE THAT
LOW- LEVEL COLD AIR COULD BE AN ISSUE WITH WINTRY MIX POSSIBLE IN
NORTHERN REGIONS SHOULD THIS HIGHLY UNCERTAIN WAVE ARRIVE AS
FORECAST LATER THIS WEEKEND.
TUESDAY AFTERNOON INTO EARLY WEDNESDAY SHOULD SEE YET ANOTHER CLIPPER
SYSTEM SPREAD SOME LIGHT SNOW INTO THE AREA DRAGGING SOME COLD AIR
INTO THE REGION. NOT NEARLY AS COLD AS THE PREVIOUS SURGES HAVE
BEEN.
THE QPF VALUES ARE VERY LIGHT...NOT SURPRISING AS THE MAIN
LOW IS CURRENTLY FORECAST TO PASS TO OUR NORTH...VIOLATING ONE OF
THE RULES OF CLIPPERS AND WHERE YOU WANT TO BE TO GET MORE SNOW.
THE SYSTEM DOES DRAG A STRONG SURFACE RIDGE INTO THE REGION WHICH
SUGGESTS THE LOW-LEVEL COLD AIR WILL BE SLOW TO RETREAT ON
THURSDAY AND FRIDAY.
ANOTHER NORTHERN STREAM IMPULSE POSSIBLE IN THE LATE THURSDAY-
FRIDAY TIME-FRAME WITH INDICATIONS OF A LIGHT SNOW EVENT OVER
NORTHERN TIER AREAS. THIS SYSTEM ERODES THE STRONG SURFACE RIDGE A
BIT FRIDAY INTO SATURDAY. THERE ARE HINTS OF POSSIBLE MIXED
PRECIPITATION ISSUES AS GEFS SHOWS POTENTIAL FOR LIGHT FREEZING
RAIN IN CENTRAL AREAS OVER THE RETREATING COLD AIR. MAINLY SNOW
NORTHERN AREAS.
DESPITE THE HIGH HEIGHTS THIS COMING WEEKEND AND THE WARM 850 HPA
TEMPERATURES THE GEFS IMPLIES THE POTENTIAL AT LEAST IN NORTHERN
PA FOR A WINTRY MIX SUNDAY. THE STRONG SURFACE RIDGE IS PRESENT
AGAIN BY SATURDAY AND SUNDAY. GEFS AND CMCEFS SHOW A SORT OF
CLASSIC COLD AIR DAMMING SCENARIO OVER THE WEEKEND.
SO DESPITE THE LARGER SCALE HEIGHT RISES AND WARMER TEMPERATURES
ALOFT BY THE WEEKEND. THE LOW-LEVEL COLD AIR COULD MAKE THE TWO
EXPECTED PRECIPITATION EVENTS A BIT MORE INTERESTING THAN +1 TO
+3C 850 HPA TEMPERATURES WOULD IMPLY. AT THIS TIME MOST OF THE
PRECIPITATION EVENTS...TUEDAYS...FRIDAY AND SUNDAY TIME-FRAME LOOK
A BIT MOISTURE STARVED.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
UPWARD MOTION AHEAD OF NEXT UPSTREAM CLIPPER HELPING TO THICKEN
MID CLOUDS ACROSS THE REGION THIS MORNING.
WEAK LOW PRES SYSTEM TRACKING SOUTH OF PA WILL SPREAD LIGHT SNOW
AND DETERIORATING VSBYS ACROSS MAINLY SOUTHWEST PA STARTING THIS AFTN.
IFR CONDS APPEAR LIKELY AT JST...WHERE OROGRAPHIC LIFT WILL
ENHANCE THE SNOW...AND POSSIBLE AT AOO.
OUTLOOK...
TUE...EARLY FOG POSSIBLE. LGT SNOW/REDUCED VSBYS POSS LATE.
WED...NO SIG WX EXPECTED.
THU...SNOW POSSIBLE LATE...MAINLY NORTH.
FRI...SNOW POSSIBLE EARLY...MAINLY NORTH.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW ADVISORY UNTIL 1 AM EST TUESDAY FOR PAZ004-
005.
WINTER WEATHER ADVISORY UNTIL 1 AM EST TUESDAY FOR PAZ024-033.
&&
$$
SYNOPSIS...GRUMM
NEAR TERM...GRUMM
SHORT TERM...GRUMM
LONG TERM...GRUMM/LAMBERT
AVIATION...FITZGERALD/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
648 AM EST MON FEB 4 2013
.SYNOPSIS...
A DEEP 500 HPA TROUGH OVER EASTERN NORTH AMERICA WILL SLOWLY
WEAKEN AND LIFT OUT AS THE WEEK PROGRESSES. AT LEAST TWO CLIPPER
LIKE WAVES WILL MOVE ACROSS OUR AREA MONDAY AND TUESDAY...AS THIS
HAPPENS. BY THE END OF THE WEEK THE TROUGH AND LOW-LEVEL COLD AIR WILL
BE REPLACED BY A RIDGE AND GENERALLY WARMER AIR. THIS IMPLIES A
GENERAL WARMING TREND AS THE WEEK PROGRESSES AS 850 HPA
TEMPERATURES SHOULD BE ABOUT 1 STANDARD DEVIATION ABOVE NORMAL BY
THE WEEKEND.
&&
.NEAR TERM /UNTIL 10 AM THIS MORNING/...
RADAR STILL SHOWS NARROW BANDS OF LIGHT SNOW OVER CENTRAL PA WHICH
DO NOT EXTEND MUCH BEYOND THE RIDGE VALLEY SYSTEM. NO REPORTS OF
ANY SIGNIFICANT SNOWS. BEST SNOW AREAS APPEAR JUST NORTH OF NY/PA
BORDER AND SW MTS WERE OBSERVATIONS AND RADAR SHOWED MORE
CONSISTENT SNOWS. SATELLITE IMAGERY SEEMS TO SHOW THE CLOUDS
COVERING MOSTLY WESTERN HALF TO ABOUT TWO THIRDS OF THE STATE. HAS
BEEN MOSTLY CLEAR IN SOME OF SOUTHEASTERN AREAS.
THE CIRRUS WITH THE APPROACHING CLIPPER HAS MOVED OVER MOST OF
OHIO AND SHOULD BE IN PA WITHIN HOURS. AFTERNOON SNOW IS GETTING CLOSER.
TEMPERATURES MAINLY IN THE TEENS AND TWENTIES ACROSS THE REGION
THIS MORNING WITH STEADY WEST WINDS. SHOULD SEE SLOW RISE IN TEMPS
THIS AM AND STEADILY INCREASING CLOUDS...THOUGH MOSTLY CLOUDY IN
WEST WITH ALL THE LOW CLOUDS.
&&
.SHORT TERM /10 AM THIS MORNING THROUGH 6 PM TUESDAY/...
THE CLOUDS FROM THE CLIPPER ARE CLEARLY ZIPPING ACROSS OHIO THIS
MORNING AND HEADED OUR WAY FAST. TIMING LOOKS GOOD AND CONSISTENT
WITH RAP AND 06Z NAM CLOSE TO PREVIOUS FORECASTS OF 03Z SREF.
EXPECT SNOW TO ARRIVE AN HOUR OF ABOUT 2 PM IN THE WEST.
ONLY RUB IS THE 06Z NAM IMPLIES THERE COULD BE SOME SPOTTY 0.4 TO
0.50 INCH QPF VALUES IN EXTREME SW PA. A FEW HIGHER ELEVATIONS
SITES WITH 16 TO 20:1 RATIOS COULD SEE OVER 6 INCHES OF SNOW.
THOUGH MOST LOCATIONS SHOULD BE IN THE MORE GENERAL 3-5 RANGE. SO
DID NOT PUT UP A WINTER STORM WARNING FOR WHAT MIGHT BE HEAVY SNOW
ON HIGHER RIDGES OF SOMERSET COUNTY. BUT THERE COULD BE SOME
ISOLATED AMOUNTS AROUND OR JUST OVER 6 INCHES.
PREVIOUS DISCUSSION STILL VALID:
THE LATEST HIGH RESOLUTION MODELS ALL IMPLY A BRIEF PERIOD OF PERHAPS
MODERATE SNOW IN THE SW AREAS NEAR THE MD BORDER. THE 03Z SREF TOO
SUPPORTS THIS CONCEPT WITH SNOW ARRIVING A FEW HOURS EITHER SIDE
OF ABOUT 2 PM IN WESTERN PA. THE SREF IMPLIES 0.1 TO 0.20 INCHES
OF QPF IN SW MOUNTAINS WHICH WOULD BE A GOOD 4-5 INCHES OF VERY
FLUFFY SNOW. THE SREF MEAN IMPLIES ISOLATED 0.30 AREAS FOR STORM
TOTALS IN SOMERSET COUNTY. THE AXIS OF HIGHEST POPS AND HIGHEST
QPFS RUN ALONG THE PA/MD BORDER AND SOUTH. THOUGH BEST QPF IN OUR
AREA ARE IN SW MTS.
INDICATIONS ARE MOST OF THE SYNOPTIC SNOWS WILL END QUICKLY
BETWEEN 10 PM AND 1 AM TONIGHT. SHOWED SNOW AMOUNTS RAPIDLY
LOWERING TO NORTH WITH EVENT AND SNOW:WATER RATIOS IN THE 16 TO
20:1 RANGE.
SREF IS NOT OPTIMISTIC WITH THE 3-5 INCHES IN NW AREAS BUT THIS
COULD BE A MODEL RESOLUTION ISSUE AND DID NOT MESS WITH THIS TOO
MUCH UNTIL WE SEE NEWER GUIDANCE.
STRONG WESTERLY WIND MAXIMUM MOVES OVER SOUTHERN TIER MONDAY
AFTERNOON SO WE COULD BRING DOWN GUSTS IN 15 TO 20 MPH RANGE.
THE WINTER WEATHER ADVISORY FOR THE LAURELS TO 06Z TUESDAY AND
ISSUED A LAKE EFFECT SNOW ADVISORY FOR THE NW MTNS FROM 00Z MONDAY
TO 06Z TUESDAY.
THE NEXT WAVE SHOULD NOT ARRIVE UNTIL TUESDAY AFTERNOON OR EVENING
WITH ANOTHER SHOT AT SOME ACCUMULATING SNOWS OF 1-2 INCHES IN
NORTHERN TIER OF MORE FLUFFY SNOWS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE SECOND CLIPPER WILL BRING SNOW (SEE ABOVE) TO THE REGION
MAINLY LATE TUESDAY AFTERNOON INTO TUESDAY NIGHT. BEST CHANCE OF
1-2 INCHES OF SNOW SHOULD BE ACROSS NORTHERN AREAS.
PREVIOUS DISCUSSION...THE LARGER SCALE PATTERN TUESDAY THROUGH
SUNDAY SHOWS THE TROUGH OVER THE EAST WEAKENING AND LIFTING OUT.
BY THE WEEKEND THE 500 HPA HEIGHTS SHOULD BE SLIGHTLY ABOVE NORMAL
AS WELL AS THE 850 HPA TEMPERATURES. NORTHERN STREAM SHORT-WAVES
COULD BRING PRECIPITATION TUESDAY INTO EARLY
WEDNESDAY...FRIDAY...AND SUNDAY INTO MONDAY. SOME HINTS ARE THAT
LOW- LEVEL COLD AIR COULD BE AN ISSUE WITH WINTRY MIX POSSIBLE IN
NORTHERN REGIONS SHOULD THIS HIGHLY UNCERTAIN WAVE ARRIVE AS
FORECAST LATER THIS WEEKEND.
TUESDAY AFTERNOON INTO EARLY WEDNESDAY SHOULD SEE YET ANOTHER CLIPPER
SYSTEM SPREAD SOME LIGHT SNOW INTO THE AREA DRAGGING SOME COLD AIR
INTO THE REGION. NOT NEARLY AS COLD AS THE PREVIOUS SURGES HAVE
BEEN.
THE QPF VALUES ARE VERY LIGHT...NOT SURPRISING AS THE MAIN
LOW IS CURRENTLY FORECAST TO PASS TO OUR NORTH...VIOLATING ONE OF
THE RULES OF CLIPPERS AND WHERE YOU WANT TO BE TO GET MORE SNOW.
THE SYSTEM DOES DRAG A STRONG SURFACE RIDGE INTO THE REGION WHICH
SUGGESTS THE LOW-LEVEL COLD AIR WILL BE SLOW TO RETREAT ON
THURSDAY AND FRIDAY.
ANOTHER NORTHERN STREAM IMPULSE POSSIBLE IN THE LATE THURSDAY-
FRIDAY TIME-FRAME WITH INDICATIONS OF A LIGHT SNOW EVENT OVER
NORTHERN TIER AREAS. THIS SYSTEM ERODES THE STRONG SURFACE RIDGE A
BIT FRIDAY INTO SATURDAY. THERE ARE HINTS OF POSSIBLE MIXED
PRECIPITATION ISSUES AS GEFS SHOWS POTENTIAL FOR LIGHT FREEZING
RAIN IN CENTRAL AREAS OVER THE RETREATING COLD AIR. MAINLY SNOW
NORTHERN AREAS.
DESPITE THE HIGH HEIGHTS THIS COMING WEEKEND AND THE WARM 850 HPA
TEMPERATURES THE GEFS IMPLIES THE POTENTIAL AT LEAST IN NORTHERN
PA FOR A WINTRY MIX SUNDAY. THE STRONG SURFACE RIDGE IS PRESENT
AGAIN BY SATURDAY AND SUNDAY. GEFS AND CMCEFS SHOW A SORT OF
CLASSIC COLD AIR DAMMING SCENARIO OVER THE WEEKEND.
SO DESPITE THE LARGER SCALE HEIGHT RISES AND WARMER TEMPERATURES
ALOFT BY THE WEEKEND. THE LOW-LEVEL COLD AIR COULD MAKE THE TWO
EXPECTED PRECIPITATION EVENTS A BIT MORE INTERESTING THAN +1 TO
+3C 850 HPA TEMPERATURES WOULD IMPLY. AT THIS TIME MOST OF THE
PRECIPITATION EVENTS...TUEDAYS...FRIDAY AND SUNDAY TIME-FRAME LOOK
A BIT MOISTURE STARVED.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
COLD FRONT HAS PUSHED EAST OF CENTRAL PA LATE THIS EVENING. A
DRIER WESTERLY FLOW IN THE WAKE OF THE FRONT SHOULD ENSURE VFR
CONDS ACROSS THE SUSQ VALLEY FOR THE REST OF THE NIGHT. OVER THE W
MTNS...RESIDUAL LOW LVL MOISTURE ASCENDING THE HIGH TERRAIN
CONTINUES TO PRODUCE -SN/LOWER VSBYS AT JST AS OF 03Z.
HOWEVER...LOWERING INVERSION HGTS WILL LIKELY CAUSE -SN TO TAPER
OFF AFTER MIDNIGHT. HOWEVER...MDL DATA SUPPORTS A CONTINUATION OF
MVFR STRATOCU OVERNIGHT AT BFD AND JST. IN ADDITION...A TIGHT PRES
GRADIENT BEHIND COLD FRONT WILL RESULT IN A GUSTY WIND OVERNIGHT.
BUFKIT SOUNDING DATA SUPPORTS FREQUENT GUSTS TO ARND 20KTS
OVERNIGHT ACROSS THE W MTNS.
A WEAK LOW PRES SYSTEM TRACKING SOUTH OF PA WILL SPREAD LIGHT
SNOW AND DETERIORATING VSBYS ACROSS MAINLY SOUTHWEST PA MONDAY
AFTN. IFR CONDS APPEAR LIKELY AT JST...WHERE OROGRAPHIC LIFT WILL
ENHANCE THE SNOW...AND POSSIBLE AT AOO.
OUTLOOK...
TUE...EARLY FOG POSSIBLE. LGT SNOW/REDUCED VSBYS POSS LATE.
WED...NO SIG WX EXPECTED.
THU...SNOW POSSIBLE LATE...MAINLY NORTH.
FRI...SNOW POSSIBLE EARLY...MAINLY NORTH.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW ADVISORY UNTIL 1 AM EST TUESDAY FOR PAZ004-
005.
WINTER WEATHER ADVISORY UNTIL 1 AM EST TUESDAY FOR PAZ024-033.
&&
$$
SYNOPSIS...GRUMM
NEAR TERM...GRUMM
SHORT TERM...GRUMM
LONG TERM...GRUMM/LAMBERT
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
409 AM EST MON FEB 4 2013
.SYNOPSIS...
A DEEP 500 HPA TROUGH OVER EASTERN NORTH AMERICA WILL SLOWLY
WEAKEN AND LIFT OUT AS THE WEEK PROGRESSES. AT LEAST TWO CLIPPER
LIKE WAVES WILL MOVE ACROSS OUR AREA MONDAY AND TUESDAY...AS THIS
HAPPENS. BY THE END OF THE WEEK THE TROUGH AND LOW-LEVEL COLD AIR WILL
BE REPLACED BY A RIDGE AND GENERALLY WARMER AIR. THIS IMPLIES A
GENERAL WARMING TREND AS THE WEEK PROGRESSES AS 850 HPA
TEMPERATURES SHOULD BE ABOUT 1 STANDARD DEVIATION ABOVE NORMAL BY
THE WEEKEND.
&&
.NEAR TERM /UNTIL 9 AM THIS MORNING/...
TEMPERATURES MAINLY IN THE TEENS AND TWENTIES ACROSS THE REGION
THIS MORNING WITH STEADY WEST WINDS. CLOUDS FROM THE LAKE EFFECT
SNOW AREAS AND TERRAIN ENHANCED SNOW AREAS KEEP PEELING OFF TO THE
EAST AND DISSIPATING. MANY SITES IN THE LOWER SUSQUEHANNA VALLEY
HAVE BEEN CLEAR TO MOSTLY AT TIMES. CENTRAL AND WESTERN AREAS
REMAIN MOSTLY CLOUDY TO CLOUDY.
SNOW SHOWERS HAVE BEEN RELATIVELY CONFINED TO THE MOUNTAINS WITH
SLIGHTLY ENHANCED BANDS IN THE SW MOUNTAINS. THE LARGER LES BAND
HAS REMAINED MOSTLY CONFINED TO NORTH OF THE NY BORDER.
THE SNOW SHOWERS AND ACCUMULATING SNOWS SHOULD REMAIN FOCUSED INTO
THE SW MOUNTAINS AND MAINLY NEAR THE NY BORDER. THESE AREAS WILL
LIKELY WEAKEN A FEW HOURS EITHER SIDE OF 9AM BASED ON RAP AND HRRR.
&&
.SHORT TERM /9 AM THIS MORNING THROUGH 6 PM TUESDAY/...
MOST OF THE SNOW FROM THE LES AND UPSLOPE WILL DIMINISH THIS AM AS
A SHORT-WAVE APPROACHES FROM THE WEST. A MORE SYNOPTICLY DRIVEN
SNOW EVENT SHOULD DEVELOP LATE THIS MORNING AND EARLY THIS
AFTERNOON AND SPREAD TO THE EAST. THE COMBINED LES AND UPSLOPE
SNOWS WITH THE CLIPPER SHOULD BE ENOUGH TO KEEP THE ADVISORY UP
FOR THOSE LOCATION INTO THE OVERNIGHT PERIOD TONIGHT.
THE HIGH RESOLUTION MODELS ALL IMPLY A BRIEF PERIOD OF PERHAPS
MODERATE SNOW IN THE SW AREAS NEAR THE MD BORDER. THE 03Z SREF TOO
SUPPORTS THIS CONCEPT WITH SNOW ARRIVING A FEW HOURS EITHER SIDE
OF ABOUT 2 PM IN WESTERN PA. THE SREF IMPLIES 0.1 TO 0.20 INCHES
OF QPF IN SW MOUNTAINS WHICH WOULD BE A GOOD 4-5 INCHES OF VERY
FLUFFY SNOW. THE SREF MEAN IMPLIES ISOLATED 0.30 AREAS FOR STORM
TOTALS IN SOMERSET COUNTY. THE AXIS OF HIGHEST POPS AND HIGHEST
QPFS RUN ALONG THE PA/MD BORDER AND SOUTH. THOUGH BEST QPF IN OUR
AREA ARE IN SW MTS.
INDICATIONS ARE MOST OF THE SYNOPTIC SNOWS WILL END QUICKLY
BETWEEN 10 PM AND 1 AM TONIGHT. SHOWED SNOW AMOUNTS RAPIDLY
LOWERING TO NORTH WITH EVENT AND SNOW:WATER RATIOS IN THE 16 TO
20:1 RANGE.
SREF IS NOT OPTIMISTIC WITH THE 3-5 INCHES IN NW AREAS BUT THIS
COULD BE A MODEL RESOLUTION ISSUE AND DID NOT MESS WITH THIS TOO
MUCH UNTIL WE SEE NEWER GUIDANCE.
STRONG WESTERLY WIND MAXIMUM MOVES OVER SOUTHERN TIER MONDAY
AFTERNOON SO WE COULD BRING DOWN GUSTS IN 15 TO 20 MPH RANGE.
THE WINTER WEATHER ADVISORY FOR THE LAURELS TO 06Z TUESDAY AND
ISSUED A LAKE EFFECT SNOW ADVISORY FOR THE NW MTNS FROM 00Z MONDAY
TO 06Z TUESDAY.
THE NEXT WAVE SHOULD NOT ARRIVE UNTIL TUESDAY AFTERNOON OR EVENING
WITH ANOTHER SHOT AT SOME ACCUMULATING SNOWS OF 1-2 INCHES IN
NORTHERN TIER OF MORE FLUFFY SNOWS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE SECOND CLIPPER WILL BRING SNOW (SEE ABOVE) TO THE REGION
MAINLY LATE TUESDAY AFTERNOON INTO TUESDAY NIGHT. BEST CHANCE OF
1-2 INCHES OF SNOW SHOULD BE ACROSS NORTHERN AREAS.
PREVIOUS DISCUSSION...THE LARGER SCALE PATTERN TUESDAY THROUGH
SUNDAY SHOWS THE TROUGH OVER THE EAST WEAKENING AND LIFTING OUT.
BY THE WEEKEND THE 500 HPA HEIGHTS SHOULD BE SLIGHTLY ABOVE NORMAL
AS WELL AS THE 850 HPA TEMPERATURES. NORTHERN STREAM SHORT-WAVES
COULD BRING PRECIPITATION TUESDAY INTO EARLY
WEDNESDAY...FRIDAY...AND SUNDAY INTO MONDAY. SOME HINTS ARE THAT
LOW- LEVEL COLD AIR COULD BE AN ISSUE WITH WINTRY MIX POSSIBLE IN
NORTHERN REGIONS SHOULD THIS HIGHLY UNCERTAIN WAVE ARRIVE AS
FORECAST LATER THIS WEEKEND.
TUESDAY AFTERNOON INTO EARLY WEDNESDAY SHOULD SEE YET ANOTHER CLIPPER
SYSTEM SPREAD SOME LIGHT SNOW INTO THE AREA DRAGGING SOME COLD AIR
INTO THE REGION. NOT NEARLY AS COLD AS THE PREVIOUS SURGES HAVE
BEEN.
THE QPF VALUES ARE VERY LIGHT...NOT SURPRISING AS THE MAIN
LOW IS CURRENTLY FORECAST TO PASS TO OUR NORTH...VIOLATING ONE OF
THE RULES OF CLIPPERS AND WHERE YOU WANT TO BE TO GET MORE SNOW.
THE SYSTEM DOES DRAG A STRONG SURFACE RIDGE INTO THE REGION WHICH
SUGGESTS THE LOW-LEVEL COLD AIR WILL BE SLOW TO RETREAT ON
THURSDAY AND FRIDAY.
ANOTHER NORTHERN STREAM IMPULSE POSSIBLE IN THE LATE THURSDAY-
FRIDAY TIME-FRAME WITH INDICATIONS OF A LIGHT SNOW EVENT OVER
NORTHERN TIER AREAS. THIS SYSTEM ERODES THE STRONG SURFACE RIDGE A
BIT FRIDAY INTO SATURDAY. THERE ARE HINTS OF POSSIBLE MIXED
PRECIPITATION ISSUES AS GEFS SHOWS POTENTIAL FOR LIGHT FREEZING
RAIN IN CENTRAL AREAS OVER THE RETREATING COLD AIR. MAINLY SNOW
NORTHERN AREAS.
DESPITE THE HIGH HEIGHTS THIS COMING WEEKEND AND THE WARM 850 HPA
TEMPERATURES THE GEFS IMPLIES THE POTENTIAL AT LEAST IN NORTHERN
PA FOR A WINTRY MIX SUNDAY. THE STRONG SURFACE RIDGE IS PRESENT
AGAIN BY SATURDAY AND SUNDAY. GEFS AND CMCEFS SHOW A SORT OF
CLASSIC COLD AIR DAMMING SCENARIO OVER THE WEEKEND.
SO DESPITE THE LARGER SCALE HEIGHT RISES AND WARMER TEMPERATURES
ALOFT BY THE WEEKEND. THE LOW-LEVEL COLD AIR COULD MAKE THE TWO
EXPECTED PRECIPITATION EVENTS A BIT MORE INTERESTING THAN +1 TO
+3C 850 HPA TEMPERATURES WOULD IMPLY. AT THIS TIME MOST OF THE
PRECIPITATION EVENTS...TUEDAYS...FRIDAY AND SUNDAY TIME-FRAME LOOK
A BIT MOISTURE STARVED.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
COLD FRONT HAS PUSHED EAST OF CENTRAL PA LATE THIS EVENING. A
DRIER WESTERLY FLOW IN THE WAKE OF THE FRONT SHOULD ENSURE VFR
CONDS ACROSS THE SUSQ VALLEY FOR THE REST OF THE NIGHT. OVER THE W
MTNS...RESIDUAL LOW LVL MOISTURE ASCENDING THE HIGH TERRAIN
CONTINUES TO PRODUCE -SN/LOWER VSBYS AT JST AS OF 03Z.
HOWEVER...LOWERING INVERSION HGTS WILL LIKELY CAUSE -SN TO TAPER
OFF AFTER MIDNIGHT. HOWEVER...MDL DATA SUPPORTS A CONTINUATION OF
MVFR STRATOCU OVERNIGHT AT BFD AND JST. IN ADDITION...A TIGHT PRES
GRADIENT BEHIND COLD FRONT WILL RESULT IN A GUSTY WIND OVERNIGHT.
BUFKIT SOUNDING DATA SUPPORTS FREQUENT GUSTS TO ARND 20KTS
OVERNIGHT ACROSS THE W MTNS.
A WEAK LOW PRES SYSTEM TRACKING SOUTH OF PA WILL SPREAD LIGHT
SNOW AND DETERIORATING VSBYS ACROSS MAINLY SOUTHWEST PA MONDAY
AFTN. IFR CONDS APPEAR LIKELY AT JST...WHERE OROGRAPHIC LIFT WILL
ENHANCE THE SNOW...AND POSSIBLE AT AOO.
OUTLOOK...
TUE...EARLY FOG POSSIBLE. LGT SNOW/REDUCED VSBYS POSS LATE.
WED...NO SIG WX EXPECTED.
THU...SNOW POSSIBLE LATE...MAINLY NORTH.
FRI...SNOW POSSIBLE EARLY...MAINLY NORTH.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW ADVISORY UNTIL 1 AM EST TUESDAY FOR PAZ004-
005.
WINTER WEATHER ADVISORY UNTIL 1 AM EST TUESDAY FOR PAZ024-033.
&&
$$
SYNOPSIS...GRUMM
NEAR TERM...GRUMM
SHORT TERM...GRUMM/LAMBERT
LONG TERM...GRUMM/LAMBERT
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
248 AM EST MON FEB 4 2013
.SYNOPSIS...
A DEEP 500 HPA TROUGH OVER EASTERN NORTH AMERICA WILL SLOWLY
WEAKEN AND LIFT OUT AS THE WEEK PROGRESSES. AT LEAST TWO CLIPPER
LIKE WAVES WILL MOVE ACROSS OUR AREA MONDAY AND TUESDAY...AS THIS
HAPPENS. BY THE END OF THE WEEK THE TROUGH AND LOW-LEVEL COLD AIR WILL
BE REPLACED BY A RIDGE AND GENERALLY WARMER AIR. THIS IMPLIES A
GENERAL WARMING TREND AS THE WEEK PROGRESSES AS 850 HPA
TEMPERATURES SHOULD BE ABOUT 1 STANDARD DEVIATION ABOVE NORMAL BY
THE WEEKEND.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
OBSERVATIONS AND SATELLITE INDICATED MANY LOCATIONS IN SOUTHERN
TIER AND SOUTHEAST HAVE BECOME MOSTLY CLEAR THOUGH PATCHES OF
CLOUDS ARE IMPLIED BY RADAR AND 11-3.9 MICRON DATA. RADAR SHOWS
SOME THIN BANDS OF LIGHT SNOW SHOWERS OVER CENTRAL
MOUNTAINS...MAINLY NEAR AND SOUTH OF THE RADAR.
SNOW SHOWERS ARE MORE PERSISTENT IN SOUTHWEST MOUNTAINS AND CLOSE
TO LAKE ERIE. CLOUDY OVER MOST OF WESTERN PA AND SW MOUNTAINS.
BEST IMPLIED SNOW BANDS ARE NOT IN OUR COUNTY WARNING AREA.
UPDATED CLOUDS AND POPS TO REFLECT CURRENT DATA AND MINOR TWEAKS
TO TEMPERATURES. BEST SNOW PROBS OF COURSE IN SW MOUNTAINS AND
WARREN AND MCKEAN COUNTIES. 13KM RAP SHOWS THE STRONGER BAND JUST
NORTH OF THE PA BORDER WILL LIKELY WEAKEN WHEN IT DRIFTS INTO
NORTHER WARREN AND MCKEAN COUNTIES.
&&
.SHORT TERM /7 AM THIS MORNING THROUGH 6 PM TUESDAY/...
THE 04Z RAP IMPLIES THAT THE NEXT CLIPPER WILL LIKELY SPREAD SNOW
ACROSS OUR WESTERN AREAS THIS AFTERNOON...PROBABLY IN SW AREAS
WITHIN 1-2 HOURS OF 2 PM. WITH SNOW OVER MOST OF OUR WESTERN HALF
PROBABLY BY 3PM. IMPLIED BEST RATES WOULD IN THE SOUTHWESTERN
AREAS. THIS IS WILL ALIGNED WITH PREVIOUS FORECASTS.
THE SREF IMPLIES BEST SNOW PROBS AFTER 18Z AND HIGHEST AMOUNTS AND
PROBS IN SOUTHERN TIER COUNTIES. MOST OF THE SNOW IS GONE BY 06Z
TUESDAY AS THE CLIPPER RACES TO THE EAST.
UNDERWHELMING QPF VALUES IN THE 0.1 RANGE IN MOST MEMBERS BUT WITH
20:1 RATIOS COULD BE A GOOD 2 INCHES AND HIGHER END QPFS WOULD
IMPLY UP TO 4 INCHES IN SW MOUNTAINS IS A POSSIBILITY. FLUFFY LOW
WATER SNOW. FARTHER EAST QPF AMOUNTS ARE LOWER SO PROBABLY A
DUSTING TO AN INCH AT BEST. CENTRAL AREAS PROBABLY WILL SEE A
FLUFFY ACCUMULATION GENERALLY UNDER AN INCH.
SREF IS NOT OPTIMISTIC WITH THE 3-5 INCHES IN NW AREAS BUT THIS
COULD BE A MODEL RESOLUTION ISSUE AND DID NOT MESS WITH THIS TOO
MUCH UNTIL WE SEE NEWER GUIDANCE.
STRONG WESTERLY WIND MAXIMUM MOVES OVER SOUTHERN TIER MONDAY
AFTERNOON SO WE COULD BRING DOWN GUSTS IN 15 TO 20 MPH RANGE.
THE WINTER WEATHER ADVISORY FOR THE LAURELS TO 06Z TUESDAY AND
ISSUED A LAKE EFFECT SNOW ADVISORY FOR THE NW MTNS FROM 00Z MONDAY
TO 06Z TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE LARGER SCALE PATTERN TUESDAY THROUGH SUNDAY SHOWS THE TROUGH
OVER THE EAST WEAKENING AND LIFTING OUT. BY THE WEEKEND THE 500
HPA HEIGHTS SHOULD BE SLIGHTLY ABOVE NORMAL AS WELL AS THE 850 HPA TEMPERATURES.
NORTHERN STREAM SHORT-WAVES COULD BRING PRECIPITATION TUESDAY INTO
EARLY WEDNESDAY...FRIDAY...AND SUNDAY INTO MONDAY. SOME HINTS ARE THAT LOW-
LEVEL COLD AIR COULD BE AN ISSUE WITH WINTRY MIX POSSIBLE IN
NORTHERN REGIONS SHOULD THIS HIGHLY UNCERTAIN WAVE ARRIVE AS
FORECAST LATER THIS WEEKEND.
TUESDAY AFTERNOON INTO EARLY WEDNESDAY SHOULD SEE YET ANOTHER CLIPPER
SYSTEM SPREAD SOME LIGHT SNOW INTO THE AREA DRAGGING SOME COLD AIR
INTO THE REGION. NOT NEARLY AS COLD AS THE PREVIOUS SURGES HAVE
BEEN.
THE QPF VALUES ARE VERY LIGHT...NOT SURPRISING AS THE MAIN
LOW IS CURRENTLY FORECAST TO PASS TO OUR NORTH...VIOLATING ONE OF
THE RULES OF CLIPPERS AND WHERE YOU WANT TO BE TO GET MORE SNOW.
THE SYSTEM DOES DRAG A STRONG SURFACE RIDGE INTO THE REGION WHICH
SUGGESTS THE LOW-LEVEL COLD AIR WILL BE SLOW TO RETREAT ON
THURSDAY AND FRIDAY.
ANOTHER NORTHERN STREAM IMPULSE POSSIBLE IN THE LATE THURSDAY-
FRIDAY TIME-FRAME WITH INDICATIONS OF A LIGHT SNOW EVENT OVER
NORTHERN TIER AREAS. THIS SYSTEM ERODES THE STRONG SURFACE RIDGE A
BIT FRIDAY INTO SATURDAY. THERE ARE HINTS OF POSSIBLE MIXED
PRECIPITATION ISSUES AS GEFS SHOWS POTENTIAL FOR LIGHT FREEZING
RAIN IN CENTRAL AREAS OVER THE RETREATING COLD AIR. MAINLY SNOW
NORTHERN AREAS.
DESPITE THE HIGH HEIGHTS THIS COMING WEEKEND AND THE WARM 850 HPA
TEMPERATURES THE GEFS IMPLIES THE POTENTIAL AT LEAST IN NORTHERN
PA FOR A WINTRY MIX SUNDAY. THE STRONG SURFACE RIDGE IS PRESENT
AGAIN BY SATURDAY AND SUNDAY. GEFS AND CMCEFS SHOW A SORT OF
CLASSIC COLD AIR DAMMING SCENARIO OVER THE WEEKEND.
SO DESPITE THE LARGER SCALE HEIGHT RISES AND WARMER TEMPERATURES
ALOFT BY THE WEEKEND. THE LOW-LEVEL COLD AIR COULD MAKE THE TWO
EXPECTED PRECIPITATION EVENTS A BIT MORE INTERESTING THAN +1 TO
+3C 850 HPA TEMPERATURES WOULD IMPLY. AT THIS TIME MOST OF THE
PRECIPITATION EVENTS...TUEDAYS...FRIDAY AND SUNDAY TIME-FRAME LOOK
A BIT MOISTURE STARVED.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
COLD FRONT HAS PUSHED EAST OF CENTRAL PA LATE THIS EVENING. A
DRIER WESTERLY FLOW IN THE WAKE OF THE FRONT SHOULD ENSURE VFR
CONDS ACROSS THE SUSQ VALLEY FOR THE REST OF THE NIGHT. OVER THE W
MTNS...RESIDUAL LOW LVL MOISTURE ASCENDING THE HIGH TERRAIN
CONTINUES TO PRODUCE -SN/LOWER VSBYS AT JST AS OF 03Z.
HOWEVER...LOWERING INVERSION HGTS WILL LIKELY CAUSE -SN TO TAPER
OFF AFTER MIDNIGHT. HOWEVER...MDL DATA SUPPORTS A CONTINUATION OF
MVFR STRATOCU OVERNIGHT AT BFD AND JST. IN ADDITION...A TIGHT PRES
GRADIENT BEHIND COLD FRONT WILL RESULT IN A GUSTY WIND OVERNIGHT.
BUFKIT SOUNDING DATA SUPPORTS FREQUENT GUSTS TO ARND 20KTS
OVERNIGHT ACROSS THE W MTNS.
A WEAK LOW PRES SYSTEM TRACKING SOUTH OF PA WILL SPREAD LIGHT
SNOW AND DETERIORATING VSBYS ACROSS MAINLY SOUTHWEST PA MONDAY
AFTN. IFR CONDS APPEAR LIKELY AT JST...WHERE OROGRAPHIC LIFT WILL
ENHANCE THE SNOW...AND POSSIBLE AT AOO.
OUTLOOK...
TUE...EARLY FOG POSSIBLE. LGT SNOW/REDUCED VSBYS POSS LATE.
WED...NO SIG WX EXPECTED.
THU...SNOW POSSIBLE LATE...MAINLY NORTH.
FRI...SNOW POSSIBLE EARLY...MAINLY NORTH.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW ADVISORY UNTIL 1 AM EST TUESDAY FOR PAZ004-
005.
WINTER WEATHER ADVISORY UNTIL 1 AM EST TUESDAY FOR PAZ024-033.
&&
$$
SYNOPSIS...GRUMM
NEAR TERM...TYBURSKI
SHORT TERM...GRUMM/LAMBERT
LONG TERM...GRUMM/LAMBERT
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
101 AM EST MON FEB 4 2013
.SYNOPSIS...
A DEEP 500 HPA TROUGH OVER EASTERN NORTH AMERICA WILL SLOWLY
WEAKEN AND LIFT OUT AS THE WEEK PROGRESSES. AT LEAST TWO CLIPPER
LIKE WAVES WILL MOVE ACROSS OUR AREA MONDAY AND TUESDAY...AS THIS
HAPPENS. BY THE END OF THE WEEK THE TROUGH AND LOW-LEVEL COLD AIR WILL
BE REPLACED BY A RIDGE AND GENERALLY WARMER AIR. THIS IMPLIES A
GENERAL WARMING TREND AS THE WEEK PROGRESSES AS 850 HPA
TEMPERATURES SHOULD BE ABOUT 1 STANDARD DEVIATION ABOVE NORMAL BY
THE WEEKEND.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
OBSERVATIONS AND SATELLITE INDICATED MANY LOCATIONS IN SOUTHERN
TIER AND SOUTHEAST HAVE BECOME MOSTLY CLEAR THOUGH PATCHES OF
CLOUDS ARE IMPLIED BY RADAR AND 11-3.9 MICRON DATA. RADAR SHOWS
SOME THIN BANDS OF LIGHT SNOW SHOWERS OVER CENTRAL
MOUNTAINS...MAINLY NEAR AND SOUTH OF THE RADAR.
SNOW SHOWERS ARE MORE PERSISTENT IN SOUTHWEST MOUNTAINS AND CLOSE
TO LAKE ERIE. CLOUDY OVER MOST OF WESTERN PA AND SW MOUNTAINS.
BEST IMPLIED SNOW BANDS ARE NOT IN OUR COUNTY WARNING AREA.
UPDATED CLOUDS AND POPS TO REFLECT CURRENT DATA AND MINOR TWEAKS
TO TEMPERATURES. BEST SNOW PROBS OF COURSE IN SW MOUNTAINS AND
WARREN AND MCKEAN COUNTIES. 13KM RAP SHOWS THE STRONGER BAND JUST
NORTH OF THE PA BORDER WILL LIKELY WEAKEN WHEN IT DRIFTS INTO
NORTHER WARREN AND MCKEAN COUNTIES.
&&
.SHORT TERM /7 AM THIS MORNING THROUGH 6 PM TUESDAY/...
THE 04Z RAP IMPLIES THAT THE NEXT CLIPPER WILL LIKELY SPREAD SNOW
ACROSS OUR WESTERN AREAS THIS AFTERNOON...PROBABLY IN SW AREAS
WITHIN 1-2 HOURS OF 2 PM. WITH SNOW OVER MOST OF OUR WESTERN HALF
PROBABLY BY 3PM. IMPLIED BEST RATES WOULD IN THE SOUTHWESTERN
AREAS. THIS IS WILL ALIGNED WITH PREVIOUS FORECASTS.
THE SREF IMPLIES BEST SNOW PROBS AFTER 18Z AND HIGHEST AMOUNTS AND
PROBS IN SOUTHERN TIER COUNTIES. MOST OF THE SNOW IS GONE BY 06Z
TUESDAY AS THE CLIPPER RACES TO THE EAST.
UNDERWHELMING QPF VALUES IN THE 0.1 RANGE IN MOST MEMBERS BUT WITH
20:1 RATIOS COULD BE A GOOD 2 INCHES AND HIGHER END QPFS WOULD
IMPLY UP TO 4 INCHES IN SW MOUNTAINS IS A POSSIBILITY. FLUFFY LOW
WATER SNOW. FARTHER EAST QPF AMOUNTS ARE LOWER SO PROBABLY A
DUSTING TO AN INCH AT BEST. CENTRAL AREAS PROBABLY WILL SEE A
FLUFFY ACCUMULATION GENERALLY UNDER AN INCH.
SREF IS NOT OPTIMISTIC WITH THE 3-5 INCHES IN NW AREAS BUT THIS
COULD BE A MODEL RESOLUTION ISSUE AND DID NOT MESS WITH THIS TOO
MUCH UNTIL WE SEE NEWER GUIDANCE.
STRONG WESTERLY WIND MAXIMUM MOVES OVER SOUTHERN TIER MONDAY
AFTERNOON SO WE COULD BRING DOWN GUSTS IN 15 TO 20 MPH RANGE.
THE WINTER WEATHER ADVISORY FOR THE LAURELS TO 06Z TUESDAY AND
ISSUED A LAKE EFFECT SNOW ADVISORY FOR THE NW MTNS FROM 00Z MONDAY
TO 06Z TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE UPCOMING WEEK LOOKS TO BE QUITE ACTIVE...BUT THE 2 OR 3 WEATHER
FEATURES MOVING ESE IN THE FAST FLOW ALOFT DURING THE NEXT SEVERAL
DAYS WILL BE OF THE CLIPPER VARIETY...AND RELATIVELY WEAK AND
MOISTURE STARVED AT THAT.
THROUGH TUESDAY MORNING...EXPECT TO SEE ANOTHER 1-3 INCHES OF
FLUFFY SNOW ACROSS THE WRN MTNS...WITH AROUND AN INCH THROUGHOUT
THE CENTRAL RIDGE AND VALLEY REGION AND SCENT MTNS. THE LOWER AND
MID SUSQ VALLEY WILL LIKELY RECEIVE UNDER AN INCH OF NEW SNOW.
THE SECOND CLIPPER /WITH A PERIOD OF LIGHT SNOW/ SLIDES ACROSS THE
CWA TUESDAY NIGHT. SNOWFALL AMOUNTS WILL BE LIMITED TO JUST A
COATING ACROSS THE SE...WITH AN INCH OR SLIGHTLY MORE OVER THE
CENTRAL AND NW MTNS.
THE UPPER FLOW RELAXES/BECOMES MORE ZONAL FOR THE SECOND HALF OF THE
WEEK WITH A LARGE NORTH/SOUTH RIDGE OF HIGH PRESSURE AT THE SFC
SLIDING EAST FROM THE GLAKES REGION WEDNESDAY...AND BECOMING
CENTERED ACROSS THE COMMONWEALTH WEDNESDAY NIGHT.
A RETURN/SOUTHERLY LLVL FLOW DEVELOPS THURSDAY INTO FRIDAY BRINGING
MODERATING /SLIGHTLY ABOVE NORMAL TEMPS/ IN THE 30S...TO AROUND 40F
IN THE SE.
U.S. AND EC MODELS DIVERGE LATE IN THE WEEK WITH MOST OF THE MEDIUM
RANGE GUIDANCE SHOWING FAIRLY FLAT...NRN AND SRN STREAM SHORT WAVES
MOVING EAST FROM THE MISS VALLEY AND DISPLAYING LITTLE OR NO PHASING
AS THEY MOVE ACROSS THE APPALACHIANS. THE OPERATIONAL 00Z AND 12Z EC
IS THE DISTINCT OUTLIER...INDICATING STRONGER FEATURES IN BOTH THE
NRN AND SRN STREAMS AND SIGNIFICANT PHASING ACROSS THE CENTRAL
APPALACHIANS AND NERN U.S. COMPLETE WITH A DEEPENING NOR`EASTER.
LEANED TWD THE ENVELOPE OF WEAKER SOLUTIONS FOR NOW WITH JUST CHC
POS FOR LIGHT RAIN/SNOW...BUT DIDN/T COMPLETELY IGNORE THE 2
CONSECUTIVE RUNS OF THE EC SUPPORTING THIS SORT OF DEVELOPMENT FOR
VERY LATE IN THE WORK WEEK.
GRADUALLY RISING HEIGHTS OVER THE WEEKEND WILL KEEP DAYTIME TEMPS AT
LEAST SLIGHTLY ABOVE NORMAL WITH POPS LESS THAN 20 PERCENT FOR
SATURDAY INTO EARLY SUNDAY.
A SURGE OF MUCH HIGHER PWATS AND MILDER AIR ALOFT MAY MOVE INTO THE
REGION FROM THE OHIO VALLEY LATE SUNDAY AND MONDAY WITH A CHC OF
RAIN /AND POSSIBLY SOME MIXED PRECIP/. ALTHOUGH THE SPREAD IN LLVL
TEMPS AND DEEP-LAYER MOISTURE INCREASES DRAMATICALLY DURING THE END
OF THE FCST PERIOD /AS ONE WOULD EXPECT WITH THIS TYPE OF SYSTEM
7 DAYS OUT/. PWATS AHEAD OF THIS LAST SYSTEM AVERAGE 12-16MM /JUST
AROUND PLUS 1 SIGMA/...HOWEVER SOME GEFS MEMBERS INDICATE PWATS
CLIMBING AS HIGH AS 20-25MM /PLUS 2-3 SIGMA/ AT THAT TIME.
12Z EC ENSEMBLE MEAN AND THE 12Z OPERATIONAL GFS BOTH SHOW A RATHER
POTENT...SLIGHTLY SUB-1000 MB SFC LOW HEADING NE TWD THE WRN
GLAKES...WHILE THE 12Z GEFS DISPLAYS A MORE ELONGATED N/S TROUGH
WITH PERHAPS A SOUTHERN STREAM LOW STRENGTHENING AS IT MOVES NE FROM
THE LOWER MISS VALLEY. ALL SOLUTIONS SHOW A PUSH OF MILDER/MOIST AIR
WITHIN THE DEEP SWRLY FLOW FOR LATE SUNDAY INTO MONDAY.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
COLD FRONT HAS PUSHED EAST OF CENTRAL PA LATE THIS EVENING. A
DRIER WESTERLY FLOW IN THE WAKE OF THE FRONT SHOULD ENSURE VFR
CONDS ACROSS THE SUSQ VALLEY FOR THE REST OF THE NIGHT. OVER THE W
MTNS...RESIDUAL LOW LVL MOISTURE ASCENDING THE HIGH TERRAIN
CONTINUES TO PRODUCE -SN/LOWER VSBYS AT JST AS OF 03Z.
HOWEVER...LOWERING INVERSION HGTS WILL LIKELY CAUSE -SN TO TAPER
OFF AFTER MIDNIGHT. HOWEVER...MDL DATA SUPPORTS A CONTINUATION OF
MVFR STRATOCU OVERNIGHT AT BFD AND JST. IN ADDITION...A TIGHT PRES
GRADIENT BEHIND COLD FRONT WILL RESULT IN A GUSTY WIND OVERNIGHT.
BUFKIT SOUNDING DATA SUPPORTS FREQUENT GUSTS TO ARND 20KTS
OVERNIGHT ACROSS THE W MTNS.
A WEAK LOW PRES SYSTEM TRACKING SOUTH OF PA WILL SPREAD LIGHT
SNOW AND DETERIORATING VSBYS ACROSS MAINLY SOUTHWEST PA MONDAY
AFTN. IFR CONDS APPEAR LIKELY AT JST...WHERE OROGRAPHIC LIFT WILL
ENHANCE THE SNOW...AND POSSIBLE AT AOO.
OUTLOOK...
TUE...EARLY FOG POSSIBLE. LGT SNOW/REDUCED VSBYS POSS LATE.
WED...NO SIG WX EXPECTED.
THU...SNOW POSSIBLE LATE...MAINLY NORTH.
FRI...SNOW POSSIBLE EARLY...MAINLY NORTH.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW ADVISORY UNTIL 1 AM EST TUESDAY FOR PAZ004-
005.
WINTER WEATHER ADVISORY UNTIL 1 AM EST TUESDAY FOR PAZ024-033.
&&
$$
SYNOPSIS...GRUMM
NEAR TERM...TYBURSKI
SHORT TERM...GRUMM/LAMBERT
LONG TERM...LAMBERT
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1246 AM EST MON FEB 4 2013
.SYNOPSIS...
SEVERAL WEAK DISTURBANCES AT THE SURFACE AND ALOFT WILL RIPPLE
THROUGH THE PERSISTENT NORTHWEST FLOW ACROSS THE REGION INTO THE
MIDDLE OF THE UPCOMING WEEK. THESE WEATHER FEATURES WILL BRING
PERIODS OF MAINLY LIGHT SNOW TO THE REGION...AND LAKE EFFECT SNOW
SHOWERS IN THE NORTHWEST SNOWBELT...OVER THE NEXT SEVERAL DAYS.
TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH TUESDAY...BEFORE
SLOWLY MODERATING TO SLIGHTLY ABOVE NORMAL FOR THE LATTER HALF OF
THE WEEK.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
OBSERVATIONS AND SATELLITE INDICATED MANY LOCATIONS IN SOUTHERN
TIER AND SOUTHEAST HAVE BECOME MOSTLY CLEAR THOUGH PATCHES OF
CLOUDS ARE IMPLIED BY RADAR AND 11-3.9 MICRON DATA. RADAR SHOWS
SOME THIN BANDS OF LIGHT SNOW SHOWERS OVER CENTRAL
MOUNTAINS...MAINLY NEAR AND SOUTH OF THE RADAR.
SNOW SHOWERS ARE MORE PERSISTENT IN SOUTHWEST MOUNTAINS AND CLOSE
TO LAKE ERIE. CLOUDY OVER MOST OF WESTERN PA AND SW MOUNTAINS.
BEST IMPLIED SNOW BANDS ARE NOT IN OUR COUNTY WARNING AREA.
UPDATED CLOUDS AND POPS TO REFLECT CURRENT DATA AND MINOR TWEAKS
TO TEMPERATURES. BEST SNOW PROBS OF COURSE IN SW MOUNTAINS AND
WARREN AND MCKEAN COUNTIES. 13KM RAP SHOWS THE STRONGER BAND JUST
NORTH OF THE PA BORDER WILL LIKELY WEAKEN WHEN IT DRIFTS INTO
NORTHER WARREN AND MCKEAN COUNTIES.
&&
.SHORT TERM /7 AM THIS MORNING THROUGH 6 PM TUESDAY/...
THE 04Z RAP IMPLIES THAT THE NEXT CLIPPER WILL LIKELY SPREAD SNOW
ACROSS OUR WESTERN AREAS THIS AFTERNOON...PROBABLY IN SW AREAS
WITHIN 1-2 HOURS OF 2 PM. WITH SNOW OVER MOST OF OUR WESTERN HALF
PROBABLY BY 3PM. IMPLIED BEST RATES WOULD IN THE SOUTHWESTERN
AREAS. THIS IS WILL ALIGNED WITH PREVIOUS FORECASTS.
THE SREF IMPLIES BEST SNOW PROBS AFTER 18Z AND HIGHEST AMOUNTS AND
PROBS IN SOUTHERN TIER COUNTIES. MOST OF THE SNOW IS GONE BY 06Z
TUESDAY AS THE CLIPPER RACES TO THE EAST.
UNDERWHELMING QPF VALUES IN THE 0.1 RANGE IN MOST MEMBERS BUT WITH
20:1 RATIOS COULD BE A GOOD 2 INCHES AND HIGHER END QPFS WOULD
IMPLY UP TO 4 INCHES IN SW MOUNTAINS IS A POSSIBILITY. FLUFFY LOW
WATER SNOW. FARTHER EAST QPF AMOUNTS ARE LOWER SO PROBABLY A
DUSTING TO AN INCH AT BEST. CENTRAL AREAS PROBABLY WILL SEE A
FLUFFY ACCUMULATION GENERALLY UNDER AN INCH.
SREF IS NOT OPTIMISTIC WITH THE 3-5 INCHES IN NW AREAS BUT THIS
COULD BE A MODEL RESOLUTION ISSUE AND DID NOT MESS WITH THIS TOO
MUCH UNTIL WE SEE NEWER GUIDANCE.
STRONG WESTERLY WIND MAXIMUM MOVES OVER SOUTHERN TIER MONDAY
AFTERNOON SO WE COULD BRING DOWN GUSTS IN 15 TO 20 MPH RANGE.
THE WINTER WEATHER ADVISORY FOR THE LAURELS TO 06Z TUESDAY AND
ISSUED A LAKE EFFECT SNOW ADVISORY FOR THE NW MTNS FROM 00Z MONDAY
TO 06Z TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE UPCOMING WEEK LOOKS TO BE QUITE ACTIVE...BUT THE 2 OR 3 WEATHER
FEATURES MOVING ESE IN THE FAST FLOW ALOFT DURING THE NEXT SEVERAL
DAYS WILL BE OF THE CLIPPER VARIETY...AND RELATIVELY WEAK AND
MOISTURE STARVED AT THAT.
THROUGH TUESDAY MORNING...EXPECT TO SEE ANOTHER 1-3 INCHES OF
FLUFFY SNOW ACROSS THE WRN MTNS...WITH AROUND AN INCH THROUGHOUT
THE CENTRAL RIDGE AND VALLEY REGION AND SCENT MTNS. THE LOWER AND
MID SUSQ VALLEY WILL LIKELY RECEIVE UNDER AN INCH OF NEW SNOW.
THE SECOND CLIPPER /WITH A PERIOD OF LIGHT SNOW/ SLIDES ACROSS THE
CWA TUESDAY NIGHT. SNOWFALL AMOUNTS WILL BE LIMITED TO JUST A
COATING ACROSS THE SE...WITH AN INCH OR SLIGHTLY MORE OVER THE
CENTRAL AND NW MTNS.
THE UPPER FLOW RELAXES/BECOMES MORE ZONAL FOR THE SECOND HALF OF THE
WEEK WITH A LARGE NORTH/SOUTH RIDGE OF HIGH PRESSURE AT THE SFC
SLIDING EAST FROM THE GLAKES REGION WEDNESDAY...AND BECOMING
CENTERED ACROSS THE COMMONWEALTH WEDNESDAY NIGHT.
A RETURN/SOUTHERLY LLVL FLOW DEVELOPS THURSDAY INTO FRIDAY BRINGING
MODERATING /SLIGHTLY ABOVE NORMAL TEMPS/ IN THE 30S...TO AROUND 40F
IN THE SE.
U.S. AND EC MODELS DIVERGE LATE IN THE WEEK WITH MOST OF THE MEDIUM
RANGE GUIDANCE SHOWING FAIRLY FLAT...NRN AND SRN STREAM SHORT WAVES
MOVING EAST FROM THE MISS VALLEY AND DISPLAYING LITTLE OR NO PHASING
AS THEY MOVE ACROSS THE APPALACHIANS. THE OPERATIONAL 00Z AND 12Z EC
IS THE DISTINCT OUTLIER...INDICATING STRONGER FEATURES IN BOTH THE
NRN AND SRN STREAMS AND SIGNIFICANT PHASING ACROSS THE CENTRAL
APPALACHIANS AND NERN U.S. COMPLETE WITH A DEEPENING NOR`EASTER.
LEANED TWD THE ENVELOPE OF WEAKER SOLUTIONS FOR NOW WITH JUST CHC
POS FOR LIGHT RAIN/SNOW...BUT DIDN/T COMPLETELY IGNORE THE 2
CONSECUTIVE RUNS OF THE EC SUPPORTING THIS SORT OF DEVELOPMENT FOR
VERY LATE IN THE WORK WEEK.
GRADUALLY RISING HEIGHTS OVER THE WEEKEND WILL KEEP DAYTIME TEMPS AT
LEAST SLIGHTLY ABOVE NORMAL WITH POPS LESS THAN 20 PERCENT FOR
SATURDAY INTO EARLY SUNDAY.
A SURGE OF MUCH HIGHER PWATS AND MILDER AIR ALOFT MAY MOVE INTO THE
REGION FROM THE OHIO VALLEY LATE SUNDAY AND MONDAY WITH A CHC OF
RAIN /AND POSSIBLY SOME MIXED PRECIP/. ALTHOUGH THE SPREAD IN LLVL
TEMPS AND DEEP-LAYER MOISTURE INCREASES DRAMATICALLY DURING THE END
OF THE FCST PERIOD /AS ONE WOULD EXPECT WITH THIS TYPE OF SYSTEM
7 DAYS OUT/. PWATS AHEAD OF THIS LAST SYSTEM AVERAGE 12-16MM /JUST
AROUND PLUS 1 SIGMA/...HOWEVER SOME GEFS MEMBERS INDICATE PWATS
CLIMBING AS HIGH AS 20-25MM /PLUS 2-3 SIGMA/ AT THAT TIME.
12Z EC ENSEMBLE MEAN AND THE 12Z OPERATIONAL GFS BOTH SHOW A RATHER
POTENT...SLIGHTLY SUB-1000 MB SFC LOW HEADING NE TWD THE WRN
GLAKES...WHILE THE 12Z GEFS DISPLAYS A MORE ELONGATED N/S TROUGH
WITH PERHAPS A SOUTHERN STREAM LOW STRENGTHENING AS IT MOVES NE FROM
THE LOWER MISS VALLEY. ALL SOLUTIONS SHOW A PUSH OF MILDER/MOIST AIR
WITHIN THE DEEP SWRLY FLOW FOR LATE SUNDAY INTO MONDAY.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
COLD FRONT HAS PUSHED EAST OF CENTRAL PA LATE THIS EVENING. A
DRIER WESTERLY FLOW IN THE WAKE OF THE FRONT SHOULD ENSURE VFR
CONDS ACROSS THE SUSQ VALLEY FOR THE REST OF THE NIGHT. OVER THE W
MTNS...RESIDUAL LOW LVL MOISTURE ASCENDING THE HIGH TERRAIN
CONTINUES TO PRODUCE -SN/LOWER VSBYS AT JST AS OF 03Z.
HOWEVER...LOWERING INVERSION HGTS WILL LIKELY CAUSE -SN TO TAPER
OFF AFTER MIDNIGHT. HOWEVER...MDL DATA SUPPORTS A CONTINUATION OF
MVFR STRATOCU OVERNIGHT AT BFD AND JST. IN ADDITION...A TIGHT PRES
GRADIENT BEHIND COLD FRONT WILL RESULT IN A GUSTY WIND OVERNIGHT.
BUFKIT SOUNDING DATA SUPPORTS FREQUENT GUSTS TO ARND 20KTS
OVERNIGHT ACROSS THE W MTNS.
A WEAK LOW PRES SYSTEM TRACKING SOUTH OF PA WILL SPREAD LIGHT
SNOW AND DETERIORATING VSBYS ACROSS MAINLY SOUTHWEST PA MONDAY
AFTN. IFR CONDS APPEAR LIKELY AT JST...WHERE OROGRAPHIC LIFT WILL
ENHANCE THE SNOW...AND POSSIBLE AT AOO.
OUTLOOK...
TUE...EARLY FOG POSSIBLE. LGT SNOW/REDUCED VSBYS POSS LATE.
WED...NO SIG WX EXPECTED.
THU...SNOW POSSIBLE LATE...MAINLY NORTH.
FRI...SNOW POSSIBLE EARLY...MAINLY NORTH.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW ADVISORY UNTIL 1 AM EST TUESDAY FOR PAZ004-
005.
WINTER WEATHER ADVISORY UNTIL 1 AM EST TUESDAY FOR PAZ024-033.
&&
$$
SYNOPSIS...LAMBERT/CERU
NEAR TERM...TYBURSKI
SHORT TERM...GRUMM/LAMBERT
LONG TERM...LAMBERT
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
743 AM CST MON FEB 4 2013
.UPDATE...
LIGHT RAIN AND DRIZZLE BEING REPORTED IN THE HILL COUNTRY THIS
MORNING AND SHOULD SPREAD EAST SO HAVE NUDGED POPS BACK UP IN THE
NORTH THIS MORNING. LOW LEVELS WILL MOISTEN UP TODAY AND TONIGHT
AND THINK THAT SOME PATCHY FOG MAY DEVELOP TONIGHT OVER THE
SOUTHERN HALF OF THE AREA. WON`T ADD IT YET AND WILL LET THE
INCOMING SHIFT MAKE THE CALL. OTHERWISE THE FORECAST LOOKS ON
TRACK.
45
&&
.PREV DISCUSSION... /ISSUED 543 AM CST MON FEB 4 2013/
DISCUSSION...
SEE 12Z AVIATION DISCUSSION.
AVIATION...
A S/WV COUPLED WITH AN INCREASE IN MOISTURE SHOULD YIELD LOWER
CIGS THIS AFTN AND A SLIGHT CHANCE OF SHOWERS. LATEST RAP 13
GUIDANCE SUPPORTS LIGHT RAIN DEVELOPING IN A SMALL WINDOW BETWEEN
19-00Z. FCST SOUNDINGS SUPPORT THE RAP AND NAM 12 SOLUTIONS. CONFIDENCE
FOR TONIGHT IS LOW AS NUMERIC GUIDANCE SUPPORTS VLIFR CONDS.
MODELS CONTINUE TO HINT AT WIDESPREAD AREAS OF DENSE FOG AS WELL
BUT PREFER TO TAKE A MORE CONSERVATIVE APPROACH FOR NOW. 43
PREV DISCUSSION... /ISSUED 434 AM CST MON FEB 4 2013/
DISCUSSION...
WARM WITH ABUNDANT CLOUDY COVER TODAY AND A CHANCE OF RAIN AND
SHOWERS. S/W IN NORTHEAST NEW MEXICO WILL CONTINUE TO MOVE EAST-
SOUTHEAST AND SHOULD INCREASE THE RAIN CHANCES THIS AFTERNOON AND
EVENING. PICKING UP SOME LIGHT RETURNS OVER THE HILL COUNTRY BUT
DOESN`T LOOK LIKE IT IS MAKING IT TO THE GROUND YET. EXPECT RAINS
MAINLY ACROSS THE NORTHERN 3/4THS OF THE AREA THIS AFTERNOON AND
THEN SHIFTING EAST WITH THE PROGRESSION OF THE SHORTWAVE.
INSTABILITY IS PRESENT BUT IS LIMITED AND WITH THE WEAK CAP HAVE
LOWERED POPS JUST SLIGHTLY. LIGHT PRECIP AMOUNTS SHOULD BE THE
NORM FOR THOSE THAT SEE RAIN. COLD FRONT THOUGH ALMOST NO CAA WILL
MOVE DOWN TO THE I-10 AREA OR A LITTLE NORTH OF IT TUESDAY
AFTERNOON. THE BOUNDARY LIFTS BACK NORTH ON WEDNESDAY AS MORE
VIGOROUS SUBTROPICAL S/W APPROACHES AND WITH GREATER MOISTURE
PRESENT (PW INCREASE TO 1.5") EXPECT MORE WIDESPREAD RAINFALL AND
POSSIBLY SOME HEAVIER RAINS ACROSS THE SOUTHERN HALF OF THE
BOUNDARY. SYSTEM LOOKS TO BE BETTER IN PHASE FOR PRECIP HERE.
ENSEMBLE GFS THOUGH HAS A HUGE SPREAD ON RAINFALL CHANCES SO FOR
NOW WILL FAVOR THE OPERATIONAL GFS RUN AND KEEP THE POPS IN THE
40-50 PERCENT RANGE. SLOW MOVING ASSOCIATED LOW TRACKS INTO AND
THROUGH THE AREA BY LATE THURSDAY. AGAIN THE ASSOCIATED COLD FRONT
IS HARD TO CALL A COLD FRONT GIVEN THE VERY WEAK CAA. TEMPERATURES
THIS WEEK WILL BE AT OR ABOVE NORMAL PERHAPS BY AS MUCH AS 10
DEGREES. MAY HAVE ANOTHER WELL ORGANIZED S/W THAT COMES IN ON THE
SUBTROPICAL JET LATE SUNDAY OR MONDAY WITH ANOTHER DECENT SHOT OF
RAIN.
45
MARINE...
ONSHORE WINDS WILL PREVAIL THROUGH WEDNESDAY AS AN AREA OF LOW
PRESSURE OVER THE TEXAS PANHANDLE MEANDERS ACROSS NORTH TEXAS. A
WEAK FRONT WILL APPROACH SOUTHEAST TEXAS BUT STALL WELL NORTH OF THE
COASTAL WATERS. ONSHORE WINDS ARE EXPECTED TO PREVAIL THROUGH EARLY
THURSDAY. A WEAK FRONT WILL PUSH INTO THE COASTAL WATERS ON FRIDAY
WITH A BRIEF WIND SHIFT. ONSHORE WINDS WILL REDEVELOP AND STRENGTHEN
ON SATURDAY. ANOTHER FRONT IS EXPECTED NEXT MONDAY. TIDE LEVELS ARE
EXPECTED TO REMAIN WITHIN NORMAL VALUES.
43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 72 55 72 55 72 / 40 20 10 10 20
HOUSTON (IAH) 73 58 74 56 73 / 40 30 10 10 30
GALVESTON (GLS) 69 62 70 61 70 / 30 20 10 10 50
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...45
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
543 AM CST MON FEB 4 2013
.DISCUSSION...
SEE 12Z AVIATION DISCUSSION.
&&
.AVIATION...
A S/WV COUPLED WITH AN INCREASE IN MOISTURE SHOULD YIELD LOWER
CIGS THIS AFTN AND A SLIGHT CHANCE OF SHOWERS. LATEST RAP 13
GUIDANCE SUPPORTS LIGHT RAIN DEVELOPING IN A SMALL WINDOW BETWEEN
19-00Z. FCST SOUNDINGS SUPPORT THE RAP AND NAM 12 SOLUTIONS. CONFIDENCE
FOR TONIGHT IS LOW AS NUMERIC GUIDANCE SUPPORTS VLIFR CONDS.
MODELS CONTINUE TO HINT AT WIDESPREAD AREAS OF DENSE FOG AS WELL
BUT PREFER TO TAKE A MORE CONSERVATIVE APPROACH FOR NOW. 43
&&
.PREV DISCUSSION... /ISSUED 434 AM CST MON FEB 4 2013/
DISCUSSION...
WARM WITH ABUNDANT CLOUDY COVER TODAY AND A CHANCE OF RAIN AND
SHOWERS. S/W IN NORTHEAST NEW MEXICO WILL CONTINUE TO MOVE EAST-
SOUTHEAST AND SHOULD INCREASE THE RAIN CHANCES THIS AFTERNOON AND
EVENING. PICKING UP SOME LIGHT RETURNS OVER THE HILL COUNTRY BUT
DOESN`T LOOK LIKE IT IS MAKING IT TO THE GROUND YET. EXPECT RAINS
MAINLY ACROSS THE NORTHERN 3/4THS OF THE AREA THIS AFTERNOON AND
THEN SHIFTING EAST WITH THE PROGRESSION OF THE SHORTWAVE.
INSTABILITY IS PRESENT BUT IS LIMITED AND WITH THE WEAK CAP HAVE
LOWERED POPS JUST SLIGHTLY. LIGHT PRECIP AMOUNTS SHOULD BE THE
NORM FOR THOSE THAT SEE RAIN. COLD FRONT THOUGH ALMOST NO CAA WILL
MOVE DOWN TO THE I-10 AREA OR A LITTLE NORTH OF IT TUESDAY
AFTERNOON. THE BOUNDARY LIFTS BACK NORTH ON WEDNESDAY AS MORE
VIGOROUS SUBTROPICAL S/W APPROACHES AND WITH GREATER MOISTURE
PRESENT (PW INCREASE TO 1.5") EXPECT MORE WIDESPREAD RAINFALL AND
POSSIBLY SOME HEAVIER RAINS ACROSS THE SOUTHERN HALF OF THE
BOUNDARY. SYSTEM LOOKS TO BE BETTER IN PHASE FOR PRECIP HERE.
ENSEMBLE GFS THOUGH HAS A HUGE SPREAD ON RAINFALL CHANCES SO FOR
NOW WILL FAVOR THE OPERATIONAL GFS RUN AND KEEP THE POPS IN THE
40-50 PERCENT RANGE. SLOW MOVING ASSOCIATED LOW TRACKS INTO AND
THROUGH THE AREA BY LATE THURSDAY. AGAIN THE ASSOCIATED COLD FRONT
IS HARD TO CALL A COLD FRONT GIVEN THE VERY WEAK CAA. TEMPERATURES
THIS WEEK WILL BE AT OR ABOVE NORMAL PERHAPS BY AS MUCH AS 10
DEGREES. MAY HAVE ANOTHER WELL ORGANIZED S/W THAT COMES IN ON THE
SUBTROPICAL JET LATE SUNDAY OR MONDAY WITH ANOTHER DECENT SHOT OF
RAIN.
45
MARINE...
ONSHORE WINDS WILL PREVAIL THROUGH WEDNESDAY AS AN AREA OF LOW
PRESSURE OVER THE TEXAS PANHANDLE MEANDERS ACROSS NORTH TEXAS. A
WEAK FRONT WILL APPROACH SOUTHEAST TEXAS BUT STALL WELL NORTH OF THE
COASTAL WATERS. ONSHORE WINDS ARE EXPECTED TO PREVAIL THROUGH EARLY
THURSDAY. A WEAK FRONT WILL PUSH INTO THE COASTAL WATERS ON FRIDAY
WITH A BRIEF WIND SHIFT. ONSHORE WINDS WILL REDEVELOP AND STRENGTHEN
ON SATURDAY. ANOTHER FRONT IS EXPECTED NEXT MONDAY. TIDE LEVELS ARE
EXPECTED TO REMAIN WITHIN NORMAL VALUES.
43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 72 55 72 55 72 / 20 20 10 10 20
HOUSTON (IAH) 73 58 74 56 73 / 40 30 10 10 30
GALVESTON (GLS) 69 62 70 61 70 / 30 20 10 10 50
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...45
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
308 AM CST MON FEB 4 2013
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
308 AM CST MON FEB 4 2013
FORECAST CONCERNS REMAIN ON SNOW POTENTIAL WITH THE NEXT SHORTWAVE
WAVE TROUGH TO DROP THROUGH THE AREA LATE TONIGHT AND TUESDAY AND
ANOTHER LATE TUESDAY NIGHT INTO WEDNESDAY.
07Z SURFACE ANALYSIS SHOWS AN AREA OF LOW PRESSURE NEAR SIOUX CITY
IOWA. AN AREA OF LIGHT SNOW IS CURRENTLY FOUND EXTENDING FROM
EASTERN MINNESOTA INTO THE SOUTHERN TWO THIRDS OF THE FORECAST AREA.
SNOW RATIOS SO FAR HAVE ONLY BEEN IN THE 10:1 TO 15:1 RANGE WITH 1
TO 2 INCHES OF SNOW SO FAR REPORTED AROUND THE AREA.
04.00Z DETERMINISTIC MODELS OFFER SIMILAR SOLUTIONS FOR THE SYSTEM
TONIGHT...BUT DO SHOW SOME DIFFERENCES WITH THE NEXT SYSTEM WEDNESDAY
AND WEDNESDAY NIGHT. GFS/GEM IN CLOSE AGREEMENT WITH THE TRACK OF
THE SHORTWAVE TROUGH AND QPF AMOUNTS...WHILE THE NAM IS FURTHER
NORTH AND WENT WITH THE NON NAM SOLUTIONS FOR THE TUESDAY
NIGHT/WEDNESDAY SYSTEM.
IN THE NEAR TERM...SHORTWAVE TROUGH WILL EXIT EARLY THIS
MORNING...WITH PERHAPS SOME LINGERING SNOW ACROSS SOUTHWEST
WISCONSIN BETWEEN 12Z-15Z. WILL KEEP ADVISORY IN TACT AND MAYBE
ABLE TO TRIM OFF PORTIONS BEFORE EXPIRATION. OTHERWISE HIGH
PRESSURE SETTLES OVER THE AREA. THE BIGGEST QUESTION WILL BE IF
THERE IS ANY CLEARING. CURRENTLY SKIES ARE CLEAR ACROSS NORTHERN
MINNESOTA AND INTO NORTHWEST WISCONSIN. THIS AREA HAS BEEN
PROGRESSING SOUTHWARD. MODELS SUGGEST THIS CLEARING WILL WORKS ITS
WAY SOUTHWARD INTO THE REGION AND DID TREND CLOUD GRIDS IN THIS
WAY.
FOR TONIGHT INTO TUESDAY...THE NEXT IN THE PARADE OF SHORTWAVE TROUGHS
DROPS SOUTHEAST THROUGH THE AREA. MODELS HAVE BEEN CONSISTENT WITH A
MORE NORTHERLY TRACK THAN THE PREVIOUS SYSTEMS...AFFECTING MAINLY
THE NORTHEASTERN TWO THIRDS OF THE FORECAST AREA. BOTH THE NAM AND
GFS DEPICTING SNOW BEGINNING LATE IN THE EVENING IN ZONE OF
850MB-0700MB WARM ADVECTION AHEAD OF THE MAIN WAVE...WITH THE
DEFORMATION AREA MOVING IN THEN ON TUESDAY. BOTH THE GFS AND NAM
BOTH SHOW SOME WEAK 800BM-900MB FRONTOGENESIS...ESPECIALLY LATE
TONIGHT. GIVEN SOUNDING PROFILES...EXPECT SNOW RATIOS FROM 13:1
SOUTH OF INTERSTATE 90 TO 18:1 ACROSS THE FAR NORTH. THIS WOULD
RESULT IN 1 TO 3 INCHES OF SNOW...WITH THE HIGHER AMOUNTS GENERALLY
ALONG AND NORTH OF INTERSTATE 94. THE SNOW WILL TAPER OFF TUESDAY
AFTERNOON.
QUIET WEATHER EXPECTED TUESDAY NIGHT...BUT ON WEDNESDAY UPPER FLOW
BECOMES MORE ZONAL WITH A WEAK SHORTWAVE TRAVERSING ACROSS NORTHERN
WISCONSIN. WARM ADVECTION AHEAD OF THIS FEATURE MAY RESULT IN ENOUGH
LIFT TO PRODUCE SOME LIGHT SNOW...PRIMARILY ACROSS THE FAR NORTH.
DID CONTINUE THE LOWER END PROBABILITIES AT THIS TIME. THE ASSOCIATED
SURFACE TROUGH PUSHES THROUGH WEDNESDAY NIGHT WITH THE POTENTIAL FOR
SOME LIGHT SNOW...ESPECIALLY ACROSS THE EASTERN COUNTIES.
AS FOR TEMPERATURES...READINGS WILL REMAIN SIMILAR TODAY AS WE HAVE
SEEN THE PAST SEVERAL DAYS...BUT BY TUESDAY AND WEDNESDAY AS UPPER
FLOW BECOMES MORE ZONAL WILL SEE SOME MILDER AIR PUSH INTO THE AREA
WITH HIGHS IN THE UPPER 20S TO LOWER 30S.
.LONG TERM...THURSDAY THROUGH SUNDAY
308 AM CST MON FEB 4 2013
MILDER AIR WILL DOMINATE THIS PERIOD WITH DAYTIME TEMPERATURES
CLIMBING INTO THE LOWER TO MIDDLE 30S EACH DAY. A TROUGH WILL CLEAR
THE AREA THURSDAY WITH LINGERING PRECIPITATION CHANCES. WITH THE
MILDER AIR WILL KEEP A MENTION OF RAIN/SNOW ACROSS THE SOUTHERN HALF
OF THE FORECAST AREA. QUIET WEATHER THEN EXPECTED FROM THURSDAY
NIGHT THROUGH FRIDAY NIGHT. MODEL SOLUTIONS BEGIN TO DIVERGE FOR THE
WEEKEND PERIOD AS MODELS STRUGGLE WITH HANDLING OF THE EVOLUTION OF
A LONG WAVE TROUGH AND CLOSED 500MB ACROSS THE WESTERN CONUS. 04.00Z
ECMWF MORE PROGRESSIVE AS IT PUSHES THIS SYSTEM OUT INTO THE PLAINS
SUNDAY MAINTAINING THE CLOSED LOW. HOWEVER...GFS EVOLVES THIS INTO
AN OPEN WAVE. BROAD SOUTHERLY FLOW AHEAD OF THE SYSTEM WILL PULL
MOISTURE NORTHWARD SPREADING INTO THE AREA SATURDAY THROUGH SUNDAY.
ECMWF HAS BEEN CONSISTENT WITH THIS FEATURE AND DEVELOPS A RATHER
DEEP SURFACE LOW TRACKING IT ACROSS SOUTHERN IOWA SUNDAY NIGHT.
QUESTION WILL BE HOW MUCH WARM AIR GETS PULLED NORTHWARD. 00Z ECMWF
AND GFS SHOW 850MB TEMPERATURES OF +1 TO +2 DEGREES CELSIUS PUSHING
IN SATURDAY AND SUNDAY. THE STRONGER ECMWF TRACKS A PRETTY
SIGNIFICANT BAND OF PRECIPITATION ACROSS THE FORECAST AREA...WHILE
THE GFS KEEPS THE PRECIPITATION SOUTH OF THE AREA. WITH THE MODEL
DIFFERENCES...WILL CONTINUE TO MENTION A CHANCE OF RAIN/SNOW.
&&
.AVIATION...THROUGH 06Z TUESDAY
1124 PM CST SUN FEB 3 2013
THE LIGHT SNOW HAS KEPT CONDITIONS IN THE MVFR CATEGORY TONIGHT AS
SOUNDINGS INDICATE TOO MUCH OF THE COLUMN HAS MOVED OUT OF THE
DENDRITIC GROWTH ZONE. THE HIGHEST RADAR RETURNS HAVE ALREADY
MOVED PAST KRST FOR THE MOST PART. KMPX RADAR STILL SHOWS SOME
HIGHER RETURNS UPSTREAM THAT MAY BRIEFLY HIT KRST WITH SOME LOWER
VISIBILITIES BUT MORE LIKELY TO KEEP THE VISIBILITY DOWN AT KLSE
THROUGH ABOUT 09Z OR SO. AFTER THAT...BOTH SITES SHOULD REMAIN
MVFR UNTIL HIGH PRESSURE BUILDS IN FROM THE NORTH. BOTH THE 04.00Z
NAM AND 04.03Z RAP FORECAST SOUNDINGS INDICATE THE HIGH WILL BRING
ENOUGH DRY AIR TO SCATTER THE CLOUDS OUT BY MID MORNING BUT
CONCERNED ABOUT THE BAND OF MID LEVEL CLOUDS ON THE WEST SIDE OF
THE RIDGE AXIS THAT EXTENDS ALL THE WAY BACK INTO ALBERTA. PRESENT
MOVEMENT WOULD BRING THIS OVER THE AREA SO HAVE GONE TO A HIGH VFR
CEILING MONDAY MORNING INSTEAD OF SCATTERING OUT. THE NEXT SYSTEM
IN THE NORTHWEST FLOW ALOFT WILL START TO ADVANCE TOWARD THE AREA
MONDAY EVENING. THE NAM IS THE QUICKEST TO RETURN LIGHT SNOW TO
THE AREA SUGGESTING BOTH TAF SITES COULD BE DOWN TO MVFR BY
05.06Z. ALL THE OTHER MODELS HOLD THE SNOW OFF UNTIL AFTER 05.06Z
AND WITH NOTHING MORE THAN FLURRIES BEING REPORTED NOW OVER
SASKATCHEWAN INTO ALBERTA WILL GO WITH THE SLOWER SOLUTIONS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
308 AM CST MON FEB 4 2013
WI...WINTER WEATHER ADVISORY UNTIL 8 AM CST THIS MORNING FOR WIZ032-
033-041-042-053>055-061.
MN...WINTER WEATHER ADVISORY UNTIL 8 AM CST THIS MORNING FOR MNZ079-
086>088-094>096.
IA...WINTER WEATHER ADVISORY UNTIL 8 AM CST THIS MORNING FOR
IAZ009>011-030.
&&
$$
SHORT TERM...RABERDING
LONG TERM...RABERDING
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1125 PM CST SUN FEB 3 2013
.SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT
230 PM CST SUN FEB 3 2013
SNOW SNOW AND MORE SNOW. IMPULSES CONTINUE TO MOVE ALONG THE
NORTHWEST FLOW...BRINGING LIGHT SNOW ON A NEARLY EVERYDAY BASIS.
LATEST 88-D IMAGERY AND SFC OBS INDICATE A FRONTOGENETIC BAND OF
LIGHT SNOW MOVING ACROSS SOUTHEAST MN...TRACKING SOUTHEAST TOWARD
NORTHEAST IA/SOUTHWEST WI. THE HRRR IS DOING A DECENT JOB CAPTURING
THIS...ABOUT THE ONLY MESO MODEL THAT IS. IT IS NOT PART OF THE
MAIN SYSTEM AT THE MOMENT...WHICH WILL MOVE IN EARLY THIS EVENING.
STILL...THIS LIGHT SNOW COULD RESULT IN TRACE-COUPLE TENTHS OF AN
INCH OF ACCUMULATION AS IT MOVES ACROSS.
A BAND OF SNOW WILL SLIDE EAST/SOUTHEAST ACROSS THE FORECAST AREA
TONIGHT...AS AN UPPER LEVEL SHORTWAVE TROUGH DRIVES FROM THE
NORTHERN PLAINS TO ACROSS IA BY MONDAY MORNING. RELATIVELY STRONG
SLOPING FRONTOGENETIC RESPONSE ON THE NORTH SIDE OF THE TROUGH/SFC
LOW...WITH SOME -EPV ON THE SOUTHERN PORTIONS OF THIS
LIFT...SUGGESTING THE POTENTIAL FOR ENHANCED BANDING. STRONG 275-290
K ISENTROPIC UPGLIDE WITH A GOOD PUNCH OF QG CONVERGENCE -
ESPECIALLY IN THE 850:700 MB LAYER. MESO MODELS AND NAM/GFS/EC ALL
SUGGEST THERE IS GOING TO BE A NARROW BAND OR SNOW WITH THIS
SYSTEM...
MOSTLY IN THE FRONTOGENETIC REGION. THIS HAS BEEN A CONSISTENT
SIGNAL. NORTH-SOUTH RUNNING TIME/HEIGHT X-SECTIONS SUGGEST THE
DEEPER DENDRITIC GROWTH ZONE WILL BE NORTH OF A RST-KLSE LINE...AWAY
FROM THE STRONGEST LIFT. THE STRONGER LIFT AND POTENTIAL FOR
ENHANCED BANDING COULD OFFSET THE RELATIVELY LOWER RATIOS IN THE
SOUTH. THAT SAID...OVERALL A 20-25:1 RATIO LOOKS REASONABLE...AND
PUTS 3 TO 4 INCHES IN THE FAVORED SNOW AREAS. ISOLATED 5 INCH
AMOUNTS ARE POSSIBLE. EXPANDED THE ADVISORY THIS MORNING...AND WILL
LEAVE AS CURRENTLY CONFIGURED FOR TONIGHT.
WITH A LOT OF PEOPLE OUT AT SUPERBOWL PARTIES...THERE WILL BE A
SIGNIFICANT AMOUNT OF TRAFFIC LATER THIS EVENING. SNOW WILL BE
FALLING AND THERE WILL BE ACCUMULATIONS ON ROADWAYS. CONDITIONS WILL
DETERIORATE AS THE EVENING WEARS ON. THE MORNING COMMUTE WILL ALSO
BE IMPACTED.
MONDAY NIGHT/TUESDAY MORNING DROPS ANOTHER SHORTWAVE TROUGH ACROSS
THE REGION...BUT THIS GO AROUND THE 03.12Z GFS AND NAM FAVOR A BIT
MORE NORTHERN TRACK. FAIRLY CONSISTENT WITH THEIR PREVIOUS RUNS.
DECENT AMOUNT OF QG CONVERGENCE WITH THE SHORTWAVE...ALONG WITH
UPGLIDE ON THE 280-295 K ISENTROPIC SFCS. SOME WEAK FRONTOGENETIC
RESPONSE IN THE 900-800MB ON THE LEADING EDGE OF THE SHORTWAVE. NOT
NEARLY AS DYNAMIC AS THE SYSTEM FOR TONIGHT...BUT PACKS ENOUGH OF A
PUNCH FOR ANOTHER ROUND OF LIGHT SNOW WITH MINOR ACCUMULATIONS.
NAM/GFS BUFKIT SOUNDINGS DON/T INDICATE A VERY DEEP DENDRITIC GROWTH
REGION...WHICH WILL HELP KEEP RATIOS LOWER...AND THUS SNOW AMOUNTS.
15:1 SEEMS REASONABLE AT THIS TIME...WHICH WOULD RESULT IN ABOUT 1-2
INCHES OF ACCUMULATION...MORE LIKELY NORTH/EAST OF THE I-94
CORRIDOR. WHILE AN ADVISORY SHOULD NOT BE NEEDED WITH THIS
SYSTEM...TIMING WOULD RESULT IN LIGHT SNOW FALLING DURING THE
MORNING RUSH.
FINALLY...THE CABOOSE FOR THIS TRAIN OF NORTHWEST SHORTWAVES ARRIVES
WED NIGHT...WITH AGAIN GOOD CONTINUITY BETWEEN THE GFS AND NAM.
COULD BE A COUPLE SHORTWAVES WORKING IN CONCERT DURING THIS
PERIOD...ALONG WITH AN ELEMENT OF MOISTURE RETURN/SOUTHERLY FLOW
AHEAD OF IT. THE GFS AND ECMWF SUGGEST THIS...DEVELOPING QPF IN THIS
REGION...ALONG AN ASSOCIATED SFC FRONT. SNOW RATIOS LOOK MORE IN
THE 15:1 RATIO...AND THE SYSTEM MOVES THROUGH PRETTY QUICK. DON/T
ANTICIPATE MUCH ACCUMULATION AT THIS TIME...GENERALLY UNDER AN
INCH.
.LONG TERM...THURSDAY THROUGH SUNDAY
230 PM CST SUN FEB 3 2013
FINALLY...A BREAK FROM THE NEARLY DAILY SNOW WITH HIGH PRESSURE
BUILDING IN THU NIGHT/FRI. ITS A SHORT LIVED BREAK THOUGH AS THE GFS
AND ECMWF BOTH BRING A STORM SYSTEM OUT OF THE SOUTHWEST AND ACROSS
THE REGION FOR THE WEEKEND. DIFFERENCES CONTINUE WITH THE
STRENGTH...SPEED...AND PLACEMENT OF THE SYSTEM...WHICH ALSO IMPACTS
AMOUNTS. PTYPE WILL ALSO BE A CONCERN AS THERE WILL BE A GOOD SURGE
OF WARMER AIR ON THE EASTERN SIDE OF THE LOW. THE GFS IS THE MORE
AGGRESSIVE WITH ITS AMOUNT OF MOISTURE/QPF AND WARMING. IT HAS A LOT
MORE QPF...ESPECIALLY OUT AHEAD OF THE LOW IN THE MOISTURE
TRANSPORT/WARM AIR ADVECTIVE REGION. BOTH AGREE THERE WILL BE A
DEFORMATION REGION OF SNOW TO THE NORTHWEST OF THE LOW...WITH
SIGNIFICANT AMOUNTS. IT WOULDN/T BE THE FLUFFY...EASY TO MOVE SNOW
EITHER. ITS DEFINITELY A STORM THAT BEARS A CLOSE WATCH.
&&
.AVIATION...THROUGH 06Z TUESDAY
1124 PM CST SUN FEB 3 2013
THE LIGHT SNOW HAS KEPT CONDITIONS IN THE MVFR CATEGORY TONIGHT AS
SOUNDINGS INDICATE TOO MUCH OF THE COLUMN HAS MOVED OUT OF THE
DENDRITIC GROWTH ZONE. THE HIGHEST RADAR RETURNS HAVE ALREADY
MOVED PAST KRST FOR THE MOST PART. KMPX RADAR STILL SHOWS SOME
HIGHER RETURNS UPSTREAM THAT MAY BRIEFLY HIT KRST WITH SOME LOWER
VISIBILITIES BUT MORE LIKELY TO KEEP THE VISIBILITY DOWN AT KLSE
THROUGH ABOUT 09Z OR SO. AFTER THAT...BOTH SITES SHOULD REMAIN
MVFR UNTIL HIGH PRESSURE BUILDS IN FROM THE NORTH. BOTH THE 04.00Z
NAM AND 04.03Z RAP FORECAST SOUNDINGS INDICATE THE HIGH WILL BRING
ENOUGH DRY AIR TO SCATTER THE CLOUDS OUT BY MID MORNING BUT
CONCERNED ABOUT THE BAND OF MID LEVEL CLOUDS ON THE WEST SIDE OF
THE RIDGE AXIS THAT EXTENDS ALL THE WAY BACK INTO ALBERTA. PRESENT
MOVEMENT WOULD BRING THIS OVER THE AREA SO HAVE GONE TO A HIGH VFR
CEILING MONDAY MORNING INSTEAD OF SCATTERING OUT. THE NEXT SYSTEM
IN THE NORTHWEST FLOW ALOFT WILL START TO ADVANCE TOWARD THE AREA
MONDAY EVENING. THE NAM IS THE QUICKEST TO RETURN LIGHT SNOW TO
THE AREA SUGGESTING BOTH TAF SITES COULD BE DOWN TO MVFR BY
05.06Z. ALL THE OTHER MODELS HOLD THE SNOW OFF UNTIL AFTER 05.06Z
AND WITH NOTHING MORE THAN FLURRIES BEING REPORTED NOW OVER
SASKATCHEWAN INTO ALBERTA WILL GO WITH THE SLOWER SOLUTIONS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
230 PM CST SUN FEB 3 2013
WI...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 8 AM CST
MONDAY FOR WIZ032-033-041-042-053>055-061.
MN...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 8 AM CST
MONDAY FOR MNZ079-086>088-094>096.
IA...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 8 AM CST
MONDAY FOR IAZ009>011-030.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...04
AREA FORECAST DISCUSSION
NWS ALBANY NY
100 AM EST WED FEB 6 2013
.SYNOPSIS...
A CLIPPER SYSTEM WILL APPROACH AND MOVE ACROSS THE REGION
TONIGHT...BRINGING SOME VERY LIGHT SNOW TO THE AREA. FAIR WEATHER
IS EXPECTED MID WEEK AS HIGH PRESSURE BUILDS IN. A WIDESPREAD
SNOWFALL IS ANTICIPATED FOR FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 1230 AM...RADAR CONTINUES TO SHOW VERY LIGHT ECHO RETURNS WITH
OBSERVATION SITES REPORTING LITTLE IF ANY SNOW ACTUALLY REACHING THE
GROUND. WILL ONLY FORECAST SCT SNOW SHOWERS FOR THE REST OF TONIGHT
WITH POPS OF 40 TO 50 PERCENT. HAVE ALSO ADJUSTED HOURLY TEMPS TO
REFLECT CURRENT CONDITIONS.
.PREVIOUS DISCUSSION...
AS OF 930 PM...LATEST RADAR AND SURFACE OBSERVATIONS ARE SHOWING
SOME LIGHT SNOW SHOWERS ACROSS AREAS SOUTH OF THE CAPITAL
DISTRICT. THE LATEST RADAR TRENDS HAVE WEAKENED FROM A FEW HOURS
AGO. OVERALL THE SNOW ACCUMULATION WILL BE VERY LIGHT...GENERALLY
A COATING AT MOST LOCATIONS. LOOKING AT THE BIGGER PICTURE...THE
SNOW SHOWERS WEST OF THE AREA ARE STARTING TO WEAKEN AS THEY ARE
RUNNING INTO DRIER AIR. LATEST SURFACE OBSERVATIONS SHOWING A
SPREAD BETWEEN TEMPS AND DEWPOINTS. 00Z ALY SOUNDING VERY DRY WITH
AN INVERSION AT 800 MB. OVERALL WILL ADJUST OVERNIGHT QPF VALUES
WITH THE CLIPPER. WILL KEEP HIGH CHANCE POPS OF SNOW SHOWERS...BUT
NOT EXPECTING TOO MUCH IN ACCUMULATION.
PREV DISC... PER THE H2O VAPOR LOOP ANALYSIS...A FAST MOVING
SHORT WAVE WAS CROSSING THE LOWER GREAT LAKES REGION THIS
AFTERNOON. REGIONAL RADARS SHOW A SCT-BKN LINE OF PRECIPITATION
THAT WAS ASSOCIATED WITH WEAK FORCING. THIS FORCING IS EXPECTED TO
REMAIN QUASI- FOCUSED AS IT MIGRATES ACROSS THE CWFA. EXPERIENTIAL
FORECAST REFLECTIVITIES LEAD BY THE HRRR ALL SUGGEST A SCATTERED
NATURE TO THE SNOWFALL TONIGHT. ALONG WITH THE MOS GUIDANCE...WE
WILL DROP BACK POPS TO THE HIGH CHC-SCT CATEGORY WITH
ACCUMULATIONS LESS THAN 1 INCH FOR MOST LOCATIONS. THE CLOUD COVER
WILL LIKELY REMAIN EXTENSIVE OVERNIGHT WHICH SHOULD KEEP TEMPS A
LITTLE MILDER THAN THIS MORNINGS VALUES.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
WEDNESDAY...
MINOR LAKE EFFECT SNOW EVENT WILL BE POSSIBLE FOR PORTIONS OF THE
MOHAWK VALLEY AND ADIRONDACKS IN THE MORNING BEFORE THOSE
INVERSION HEIGHTS COLLAPSE TOWARD NOON. OTHERWISE...VARIABLE CLOUD
COVER WILL BEGIN TO SLOWLY IMPROVE THROUGH THE DAY AS TEMPERATURES
CLIMB INTO THE LOW-MID 30S FOR VALLEY LOCATIONS AND 20S ELSEWHERE.
WINDS WILL BE RATHER GUSTY THROUGH THE DAY AS WE MIX UP TO 30KT
MAGNITUDES. FURTHERMORE...THOSE WINDS MAY GET FUNNELED DOWN THE
MOHAWK RIVER FOR A SLIGHT ENHANCEMENT TO THOSE WESTERLY WINDS
THROUGH THE DAY.
WEDNESDAY NIGHT...
RIDGE OF HIGH PRESSURE WILL CREST OVER THE REGION. THIS WILL ALLOW
FOR...INITIALLY...CLEAR SKIES THROUGH THE EVENING HOURS WHICH WILL
SEND TEMPS QUICKLY DOWNWARD WITH NEAR IDEAL RADIATIONAL COOLING
/CLEAR SKIES AND LIGHT WINDS WITH A FROZEN AND PARTIAL SNOW
COVERED GROUND/. THEN WE WILL WATCH UPSTREAM CONDITIONS CLOSELY AS
STRONG PACIFIC ENERGY COMES ASHORE AND TRACKS ACROSS THE CENTER OF
THE NATION. NCEP MODEL SUITE ALONG WITH INTERNATIONAL GUIDANCE ARE
IN RATHER GOOD AGREEMENT WITH BROAD WARM ADVECTION ALOFT TO
COMMENCE OVERNIGHT WEDNESDAY INTO SUNRISE THURSDAY MORNING.
ISENTROPIC ANALYSIS ON THE 285-290K SURFACE SUPPORTS BROAD
ISENTROPIC LIFT AND SLOWLY LOWERING CPD/S TO RESULT WITH AN
INCREASE OF CLOUD COVER. THESE CLOUDS SHOULD LIMIT FURTHER
DECLINES IN THE TEMPERATURES OVERNIGHT AND MAY EVEN SEE A SLOW
REBOUND TOWARD SUNRISE.
THURSDAY...
THE AFOREMENTIONED ISENTROPIC LIFT CONTINUES THROUGH THE DAY
THURSDAY WITH A CONTINUE DECREASE IN THOSE CPD/S. THIS SHOULD
RESULT IN THE THICKENING AND LOWERING OF THE CLOUD DECK AND THE
CHANCE FOR OVERRUNNING LIGHT SNOW TO DEVELOP. WHILE MODEL QPF
SIGNALS ARE NOT SHOWING THIS ACROSS OUR REGION /THEY DO SO FURTHER
UPSTREAM/...THE COMBINATION OF CONTINUED ISENTROPIC LIFT AND LESS
THAN 30MB CPD/S...WE WILL PLACE CHC POPS ACROSS THE NORTHERN 1/2
OF THE CWFA BEGINNING BY LATE MORNING. THE BEST CHANCE FOR AN
ACCUMULATING SNOWFALL WILL LIKELY REMAIN ALONG AND NORTH OF I90
WHERE THE BEST LIFT AND MOISTURE PROFILES ARE EXPECTED AND VALUES
UP TO 1 INCH POSSIBLE. AS FOR TEMPERATURES...THE LOW LEVEL
AGEOSTROPHIC FLOW DOES INCREASE FROM THE NORTH AND THIS TOO SHOULD
LIMIT TEMPERATURES FROM GETTING OUT OF THE 20S.
THURSDAY NIGHT...
THIS WILL BE THE PERIOD OF TRANSITION TO A POTENTIAL STORM
IMPACTING THE REGION. GLOBAL MODEL TRENDS AND THE PERSISTENT ECMWF
FOR THE PAST 5 RUNS WANT TO PHASE THE NORTHERN STREAM PACIFIC
ENERGY WITH SOUTHERN STREAM WAVE/S/ ACROSS BAJA AND NORTHERN
MEXICO. LOW LEVEL SOUTHERLY JET AND MOISTURE TRANSPORT VECTORS
INCREASE RATHER RAPIDLY THURSDAY NIGHT WHERE THE CHANCE FOR LIGHT
SNOW TO INCREASE ACROSS THE REGION. GIVEN THE FORECAST WIND
TRAJECTORY AND MAGNITUDES...WE WILL FAVOR THE HIGHER TERRAIN WITH
LIKELY POPS AND HIGH CHANCE FOR THE VALLEY LOCATIONS. AS FOR
NOW...SNOWFALL AMOUNTS OF 1-2 INCHES WITH THE POSSIBILITY OF SOME
HIGHER TOTALS IN THE MOUNTAINS. GUIDANCE NUMBERS ARE FAIRLY CLOSE
AS WE LEANED MORE TOWARD THE GFS/ECMWF MOS NUMBERS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
HPC GUIDANCE. MOST MODELS NOW ON BOARD WITH A MAJOR WINTER EVENT
FOR THE END OF THE WEEK. LOW PRESSURE WILL BE NEAR VIRGINIA BEACH
AT THE START OF THE PERIOD...WITH SNOW ALREADY OVERSPREADING OUR
FORECAST AREA. THE LOW WILL TRACK TO SOUTH OF WESTERN NOVA SCOTIA
BY SATURDAY MORNING...INTENSIFYING RAPIDLY. A PERIOD OF RAIN OR A
SNOW MIX IS A POSSIBILITY BRIEFLY DURING THE DAY ON FRIDAY IN THE
LOWER SECTION OF THE MID HUDSON VALLEY...BUT FOR NOW WILL SAY IT IS
ALL SNOW. OTHERWISE...AN ALL-SNOW EVENT IS ANTICIPATED WITH
CONFIDENCE...WITH ACTIVITY WINDING DOWN SWIFTLY DURING THE DAY ON
FRIDAY. A FLOW TURNING NORTHERLY ENHANCED BY STRONG HIGH PRESSURE
MOVING IN BY SUNDAY ENSURES THAT WE HAVE AN ALL-SNOW EVENT BEYOND
FRIDAY AFTERNOON.
AS IT LOOKS RIGHT NOW...THE LOW IS EXPECTED TO STAY WELL ENOUGH TO
THE SOUTH...SUCH THAT 6 TO 10 INCHES OF TOTAL SNOW ACCUMULATION
LOOKS MOST REASONABLE...WITH THE GREATER AMOUNTS...OF COURSE...TO
THE SOUTH AND EAST IN OUR FORECAST AREA. MORE IS POSSIBLE...BUT SO
IS LESS...DEPENDING ON HOW THE SYSTEM EVOLVES. THIS LOOKS TO BE A
BROAD-AREA SNOW-PRODUCER.
BY SATURDAY NIGHT...SKIES WILL BE MOSTLY ON THE PARTLY CLOUDY
SIDE...WITH WINDS RAPIDLY DIMINISHING TO MAKE THE NIGHT A COLD ONE.
BUT THE REPRIEVE WILL BE BRIEF AS ANOTHER SYSTEM THREATENS THE
REGION WITH A WINTRY MIX OF PRECIPITATION FOR MONDAY/MONDAY NIGHT.
A COLD FRONT SLIDES THROUGH THE REGION...WITH TUESDAY BEGINNING A
PERIOD OF LAKE EFFECT SNOW SHOWERS...MAINLY WEST OF THE CAPITAL
REGION.
HIGH TEMPERATURES WILL RANGE FROM THE MID 20S IN THE ADIRONDACKS AND
GREENS...TO THE UPPER 30S IN THE LOWER MID HUDSON VALLEY. ON
SATURDAY...ALMOST ALL AREAS WILL FAIL TO CRACK THE FREEZING MARK.
ON SUNDAY...HOWEVER...ALMOST ALL LOCATIONS WILL MAKE IT TO AT LEAST
JUST ABOVE FREEZING. HIGHS ON MONDAY WILL RANGE FROM THE MID AND
UPPER 30S IN THE ADIRONDACKS AND GREENS...TO THE UPPER 40S IN THE
MID HUDSON VALLEY. THE COLD FRONT WILL BACK OFF TUESDAY HIGH
TEMPERATURES FROM AROUND 30 DEGREES IN THE ADIRONDACKS...TO THE MID
40S IN THE MID HUDSON VALLEY.
LOW TEMPERATURES BOTH FRIDAY AND SATURDAY NIGHTS WILL RANGE FROM
AROUND ZERO IN THE ADIRONDACKS...TO THE MID TEENS IN THE LOWER MID
HUDSON VALLEY. SUNDAY NIGHT LOWS WILL RANGE FROM THE UPPER TEENS IN
THE ADIRONDACKS...TO THE UPPER 20S IN THE LOWER MID HUDSON VALLEY.
A FURTHER MODERATION WILL TAKE PLACE FOR MONDAY NIGHT.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
A WEAK LOW PRESSURE SYSTEM WILL MOVE ACROSS THE REGION THIS MORNING.
SPOTTY LIGHT SNOW WILL IMPACT THE ERN NY AND WRN NEW ENGLAND
TERMINALS THIS MORNING. THE COLD FRONT WILL SWEEP THROUGH BEFORE
NOONTIME. HIGH PRESSURE WILL BUILD IN OVER THE REGION TONIGHT INTO
THURSDAY.
SPOTTY LIGHT SNOW OR SNOW SHOWERS WILL PRODUCE MVFR CONDITIONS FOR
KPOU/KGFL/KALB/KPSF IN TERMS OF CIGS/VSBYS. THERE IS A CHANCE OF
BRIEF LAPSES TO IFR VSBYS AT KPOU AND KPSF IN THE SNOW. A TEMPO
WAS USED TO ADDRESS THIS PRIOR TO 10Z/WED. THE CIGS AND VSBYS WILL
INCREASE TO HIGH MVFR/VFR LEVELS BY DAYBREAK...AND CONTINUE TO REACH
VFR LEVELS BY NOONTIME.
THE WINDS WILL BE LIGHT TO CALM PRIOR TO 12Z/WED...THEN INCREASE
FROM THE W/NW AT 10-15 KTS BY THE LATE MORNING INTO THE AFTERNOON
WITH THE FRONTAL PASSAGE. SOME GUSTS TO AROUND 25 KTS WILL BE
POSSIBLE...ESPECIALLY AT KALB AND KPSF. EXPECT THE WINDS WILL
SUBSIDE TO LESS THAN 10 KTS AFTER 23Z/WED.
OUTLOOK...
WED NIGHT-THU...VFR. NO SIG WX.
THU NGT-FRI NIGHT. MVFR/IFR WITH SNOW LIKELY.
SAT...VFR/MVFR...CHC -SN.
SAT NIGHT-SUN...VFR...NO SIG WX
&&
.HYDROLOGY...
WIDESPREAD HYDRO PROBLEMS ARE NOT ANTICIPATED OVER THE NEXT FEW
DAYS AS OUR COLD WEATHER CONTINUES WITH ANY PRECIPITATION IN THE
FORM OF SNOW.
SOME RIVER AND STREAM GAGES ARE EXPERIENCING ICE EFFECTS. ICE
WILL CONTINUE TO FORM AND THICKEN ON ALL BODIES OF WATER.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...VTK/BGM
NEAR TERM...GJM/VTK/BGM
SHORT TERM...BGM
LONG TERM...ELH
AVIATION...WASULA
HYDROLOGY...IAA/BGM
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
408 AM EST Wed Feb 6 2013
...UPDATED FOR AVIATION AND FOG DISCUSSIONS...
.NEAR TERM [Through Today]...
The large scale split flow longwave pattern during the pre-dawn
hours was highlighted by ridging over Wrn states and broad troughing
over Ern states with low over Ern Canada with axis SWD but with
decreasing amplitude leaving near zonal flow over NE Gulf region.
Weak shortwave moving across Ern third of local area. At the
surface, weak surface wave over local area with diffuse warm
frontal extending W-E from low along N FL. Trough also extends
from low SWWD into Gulf of Mex. Along and east of low/trough/
shortwave. Local radars show area of light drizzle (SE Big Bend
and adjacent GA counties). For the remainder of pre dawn hours
into this morning, as shortwave exits Ewd, the low and trough will
continue to move ESE with drizzle exiting SEWD. This reflected
well in local WRF which has last rain exiting SE Big Bend 13z-14z.
Main immediate concern is density and duration of fog resulting from
combination of boundary, high dew points and shrinking dew point
depressions, drizzle, moist ground and near calm winds. The main
focus is west of a line from Albany to Panama City where fewer
clouds will continue to favor fog altho low stratus persistS. Local
confidence tool and SREF back up fog concerns. During the pre-dawn
hours, visibilities significantly lowered across SE AL/SW GA and
portions of the Ern FL Panhandle.
At 4 AM EST...Dothan and Albany continued to report vsbys one-half
mile or below. Thus a dense fog advisory was issued for this area
until 10 AM EST. Farther east 3-6k departing cloud shield favoring
stratus with unlimited vsbys. Local RAP time height profile and
Bufkit soundings, latest GFS and VSREF all imply that while fog will
begin to lift mid-morning, low stratus will be slower to lift with
CIGS lingering for much of the day, especially Ern counties.
Otherwise, aside from a few lingering showers across mainly the
marine area, today will be a lull in rainfall before the next
shortwave/surface reflection moves w-e across area beginning
tonight. A small chance of mainly drizzle this morning and mainly
over marine area. With low clouds lingering, tweaked down inherited
max temps a degree or two especially east of Apalachicola River.
Expect highs in the low to mid 70s.
&&
.SHORT TERM [Tonight Through Friday]...
Despite some differences on a few of the details, the 06.00z suite
of numerical model runs appears to be in fairly good agreement
about the evolution of things in the short term period. Surface
cyclogenesis should commence tonight near coastal Louisiana ahead
of a fast-moving, low-amplitude shortwave trough that is currently
located over Baja California. This shortwave will eject quickly to
the ENE in the subtropical jet stream. The models show varying
degrees of surface cyclogenesis, but the consensus is that a
developing low will be passing very near the NW corner of our
forecast area on Thursday.
There will likely be a sizable area of moderate-heavy rainfall
associated with the developing cyclone - a few ingredients point
to this: (1) a coupled upper level jet configuration, (2) strong
low-level moisture flux and theta-e advection, -AND- (3) PWATs
around 1.5-2.0 standard deviations above normal. While heavy rain
is not in doubt somewhere in the region, the key is placement. The
recent runs of the NAM, GFS, and ECMWF all place the nose of 0-2km
moisture transport and a maximum of theta-e advection in the same
layer near or just north of the northern and western boundaries of
our forecast area. Highest PoPs and coolest temperatures were
focused in the NW third of our area. To the south of that, we may
see a few breaks of sun, better mixing, and perhaps some greater
instability. The ECMWF, GFS, and NAM all show around 400-600 j/kg
of CAPE developing between 18-00z Thursday. This also happens to
coincide with the eastward development of a mid-upper level jet
streak over the "warm sector" and a similar expansion of a plume
of steeper mid-level lapse rates. Therefore, there should be a
chance for some isolated severe storms over our area - mainly from
18z Thursday to 06z Friday. Our local confidence tool and SPC SREF
calibrated severe probabilities both indicate around 5-10%
probabilities for severe storms and this seems reasonable.
QG convergence maximum quickly shifts into the Carolinas Thursday
Night, with an opposing signal (strong QG divergence) setting in
by 06z Friday. This would correspond to large scale subsidence and
thus precipitation chances should quickly diminish Thursday
evening across much of the area.
&&
.LONG TERM [Friday Night through Tuesday]...
The period begins with zonal flow followed by a building ridge over
the weekend. The ridge flattens locally by late Tuesday as a low
pressure system translates from the Central Plains to just north of
New England. At the surface, a cold front will continue to push
through the CWA Friday with slight to low end chance PoPs. This will
be followed by the passage of a secondary but dry front Friday
night/Saturday morning as high pressure noses down the eastern
seaboard. The weekend will be dry but the next low pressure system
will rapidly lift out of the plains on Sunday into the Great Lakes
Region by Monday night dragging a cold front into the SE CONUS.
There will be a slight chance of rain for most of our CWA Monday.
Rain and possibly thunderstorms will accompany the front as it
pushes across the Tri-state region Tuesday. Temperatures will be
above seasonal levels through the extended period.
&&
.AVIATION [through 06z Thursday]...
During the pre-dawn hours, low clouds and light rain or drizzle
continue as a surface low over the Gulf slides to the east. Areas
behind main cloud deck (KDHN, KABY, KECP) already experiencing
IFR or more likely LIFR fog and CIGS which will become increasingly
dense towards sunrise. Areas farther to the south and east and
under cloud cover will have vis and ceilings ranging from IFR to
MVFR. After 15z, VSBYS will rise to VFR but cigs will be slower to
rise with MVFR cigs lingering into the aftn, especially at KVLD
and possibly at KTLH. Generally ENE winds 5 to 10 mph after
fog/CIGS lift becoming light again after sundown. After 06z CIGS
and likely vsbys will again begin to deteriorate.
&&
.MARINE...
Winds will begin to increase late tonight as a surface low forms
near coastal Louisiana, and then shifts ENE towards the Carolinas
tomorrow. SCEC level winds appear likely after 06z tonight, and
could last through Thursday evening. There is a chance for some
advisory-level winds, but for now the forecast does not call for
that. Seas should peak around 5 feet west of Apalachicola. Strong
onshore flow and building seas should contribute to elevated surf
and a high risk of rip currents on Thursday.
&&
.FIRE WEATHER...
RH will remain safely above the levels needed to achieve red flag
criteria this week. Dispersion indices will be on the low side on
Today and Thursday. After a lull today, rain chances will increase
once again on Thursday. A drier airmass will dominate again Friday
thru Monday.
&&
.HYDROLOGY...
Although some heavier rain is possible over the northwest part of
our area (particularly NW of a line from Panama City to Albany),
the current low river levels should limit any sort of widespread
impacts to area rivers and streams. In general, SREF and GEFS
ensemble probabilities indicate a less than 5% chance of exceeding
bankfull stage at most of the points where data is available. Some
of the smaller basins and creeks (like the Kinchafoonee Creek)
have as much as a 10-20% chance of exceeding bankfull stage based
on ensemble QPF.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 73 57 70 58 74 / 10 20 60 40 20
Panama City 72 60 71 60 71 / 10 20 80 30 20
Dothan 73 58 69 54 70 / 10 40 80 30 10
Albany 73 56 69 53 68 / 0 30 80 40 20
Valdosta 73 55 71 58 72 / 10 20 50 40 20
Cross City 74 56 75 59 76 / 20 10 30 30 30
Apalachicola 70 60 69 60 70 / 10 10 70 40 20
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...DENSE FOG ADVISORY until 9 AM CST this morning for Calhoun-
Central Walton-Coastal Bay-Holmes-Inland Bay-Inland
Walton-Jackson-South Walton-Washington.
GA...DENSE FOG ADVISORY until 10 AM EST this morning for Baker-
Calhoun-Clay-Decatur-Dougherty-Early-Grady-Lee-Miller-
Mitchell-Quitman-Randolph-Seminole-Terrell.
AL...DENSE FOG ADVISORY until 9 AM CST this morning for Coffee-Dale-
Geneva-Henry-Houston.
GM...None.
&&
$$
NEAR TERM...Block
SHORT TERM...Lamers
LONG TERM...Barry
AVIATION...Block
MARINE...Lamers
FIRE WEATHER...Block
HYDROLOGY...Lamers
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
300 AM EST Wed Feb 6 2013
.NEAR TERM [through This Afternoon]...
The large scale split flow longwave pattern during the pre-dawn
hours was highlighted by ridging over Wrn states and very broad
troughing over Ern states with decreasing amplitude from N-S leaving
near zonal flow over NE Gulf region. Weak shortwave moving across
Ern third of local area. At the surface, weak surface wave over
local area with trough or warm frontal boundary bisecting the area
SWWD into Gulf of Mex. Along and east of low/trough/shortwave, local
radars show area of light rain (SE Big Bend and adjacent GA
counties) with light drizzle further upstream. For the remainder of
tonight into this morning, as shortwave exits Ewd, the low and
trough will continue to move ESE with decreasing rain and drizzle
exiting SEWD after sunrise. This reflected well in local WRF which
has last rain exiting SE Big Bend 13z-14z.
Main immediate concern is fog resulting from combination of
boundary, high dew points and shrinking dew point depressions,
drizzle, moist ground and near calm winds. The main focus will be
west of the Apalachicola where fewer clouds will continue to favor
fog altho low stratus will persist. Local confidence tool and SREF
back up fog concerns. During the pre dawn hours, visibilities
significantly lowered across SE AL/SW GA and portions of the Ern FL
Panhandle. At 2 AM EST...Dothan and Albany reported vsbys one-half
mile or below. Thus a dense fog advisory was issued for this area
until 10 AM EST. Farther east 3-6k departing cloud shield favoring
stratus with unlimited vsbys. Local RAP time height profile and
Bufkit soundings, latest GFS and NARRE all imply that while fog will
begin to lift mid-morning, low stratus will be slower to lift with
CIGS lingering for much of the day, especially Ern counties.
Otherwise, aside from a few lingering showers across mainly the
marine area, today will be a lull in rainfall before the next
shortwave/surface reflection moves w-e across area beginning
tonight. A small chance of mainly light rain or drizzle this mornnig
mainly over marine area. With low clouds lingering, tweaked down
inherited max temps a degree or two especially east of Apalachicola
River. Expect highs in the low to mid 70s.
&&
.SHORT TERM [Tonight Through Friday]...
Despite some differences on a few of the details, the 06.00z suite
of numerical model runs appears to be in fairly good agreement
about the evolution of things in the short term period. Surface
cyclogenesis should commence tonight near coastal Louisiana ahead
of a fast-moving, low-amplitude shortwave trough that is currently
located over Baja California. This shortwave will eject quickly to
the ENE in the subtropical jet stream. The models show varying
degrees of surface cyclogenesis, but the consensus is that a
developing low will be passing very near the NW corner of our
forecast area on Thursday.
There will likely be a sizable area of moderate-heavy rainfall
associated with the developing cyclone - a few ingredients point
to this: (1) a coupled upper level jet configuration, (2) strong
low-level moisture flux and theta-e advection, -AND- (3) PWATs
around 1.5-2.0 standard deviations above normal. While heavy rain
is not in doubt somewhere in the region, the key is placement. The
recent runs of the NAM, GFS, and ECMWF all place the nose of 0-2km
moisture transport and a maximum of theta-e advection in the same
layer near or just north of the northern and western boundaries of
our forecast area. Highest PoPs and coolest temperatures were
focused in the NW third of our area. To the south of that, we may
see a few breaks of sun, better mixing, and perhaps some greater
instability. The ECMWF, GFS, and NAM all show around 400-600 j/kg
of CAPE developing between 18-00z Thursday. This also happens to
coincide with the eastward development of a mid-upper level jet
streak over the "warm sector" and a similar expansion of a plume
of steeper mid-level lapse rates. Therefore, there should be a
chance for some isolated severe storms over our area - mainly from
18z Thursday to 06z Friday. Our local confidence tool and SPC SREF
calibrated severe probabilities both indicate around 5-10%
probabilities for severe storms and this seems reasonable.
QG convergence maximum quickly shifts into the Carolinas Thursday
Night, with an opposing signal (strong QG divergence) setting in
by 06z Friday. This would correspond to large scale subsidence and
thus precipitation chances should quickly diminish Thursday
evening across much of the area.
&&
.LONG TERM [Friday Night through Tuesday]...
The period begins with zonal flow followed by a building ridge over
the weekend. The ridge flattens locally by late Tuesday as a low
pressure system translates from the Central Plains to just north of
New England. At the surface, a cold front will continue to push
through the CWA Friday with slight to low end chance PoPs. This will
be followed by the passage of a secondary but dry front Friday
night/Saturday morning as high pressure noses down the eastern
seaboard. The weekend will be dry but the next low pressure system
will rapidly lift out of the plains on Sunday into the Great Lakes
Region by Monday night dragging a cold front into the SE CONUS.
There will be a slight chance of rain for most of our CWA Monday.
Rain and possibly thunderstorms will accompany the front as it
pushes across the Tri-state region Tuesday. Temperatures will be
above seasonal levels through the extended period.
&&
.AVIATION [through 06z Thursday]...
During the pre-dawn hours, low clouds and light rain or drizzle
continue as a surface low over the Gulf slides to the east. Areas
behind main cloud deck (KDHN, KABY, KECP) already experiencing
IFR or more likely LIFR fog and CIGS which will become increasingly
dense towards sunrise. Areas farther to the south and east and
under cloud cover will have vis and ceilings ranging from IFR to
MVFR. After 15z, VSBYS will rise to VFR but cigs will be slower to
rise with MVFR cigs lingering into the aftn, especially at KVLD
and possibly at KTLH. Generally ENE winds 5 to 10 mph after
fog/CIGS lift becoming light again after sundown. After 06z CIGS
and likely vsbys will again begin to deteriorate.
&&
.MARINE...
Winds will begin to increase late tonight as a surface low forms
near coastal Louisiana, and then shifts ENE towards the Carolinas
tomorrow. SCEC level winds appear likely after 06z tonight, and
could last through Thursday evening. There is a chance for some
advisory-level winds, but for now the forecast does not call for
that. Seas should peak around 5 feet west of Apalachicola. Strong
onshore flow and building seas should contribute to elevated surf
and a high risk of rip currents on Thursday.
&&
.FIRE WEATHER...
RH will remain safely above the levels needed to achieve red flag
criteria this week. Dispersion indices will be on the low side on
Today and Thursday. After a lull today, rain chances will increase
once again on Thursday. A drier airmass will dominate again Friday
thru Monday.
&&
.HYDROLOGY...
Although some heavier rain is possible over the northwest part of
our area (particularly NW of a line from Panama City to Albany),
the current low river levels should limit any sort of widespread
impacts to area rivers and streams. In general, SREF and GEFS
ensemble probabilities indicate a less than 5% chance of exceeding
bankfull stage at most of the points where data is available. Some
of the smaller basins and creeks (like the Kinchafoonee Creek)
have as much as a 10-20% chance of exceeding bankfull stage based
on ensemble QPF.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 73 57 70 58 74 / 10 20 60 40 20
Panama City 72 60 71 60 71 / 10 20 80 30 20
Dothan 73 58 69 54 70 / 10 40 80 30 10
Albany 73 56 69 53 68 / 0 30 80 40 20
Valdosta 73 55 71 58 72 / 10 20 50 40 20
Cross City 74 56 75 59 76 / 20 10 30 30 30
Apalachicola 70 60 69 60 70 / 10 10 70 40 20
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...DENSE FOG ADVISORY until 9 AM CST this morning for Calhoun-
Central Walton-Coastal Bay-Holmes-Inland Bay-Inland
Walton-Jackson-South Walton-Washington.
GA...DENSE FOG ADVISORY until 10 AM EST this morning for Baker-
Calhoun-Clay-Decatur-Dougherty-Early-Grady-Lee-Miller-
Mitchell-Quitman-Randolph-Seminole-Terrell.
AL...DENSE FOG ADVISORY until 9 AM CST this morning for Coffee-Dale-
Geneva-Henry-Houston.
GM...None.
&&
$$
NEAR TERM...Block
SHORT TERM...Lamers
LONG TERM...Barry
AVIATION...Block
MARINE...Lamers
FIRE WEATHER...Block
HYDROLOGY...Lamers
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1235 AM EST Wed Feb 6 2013
...UPDATED FOR DENSE FOG ADVISORY...
UPDATE...Visibilities have significantly lowered across SE AL/SW
GA and portions of the Ern FL Panhandle. At 12 AM EST...Dothan
...Albany and Ozark all reported vsbys one-half mile or below.
Thus a dense fog advisory was issued for this area until 10 AM EST.
local RAP time height profile and Bufkit soundings, latest GFS and
VSREF all imply that while fog will begin to lift mid-morning,,,low
clouds will linger for much of the day, especially Ern counties.
wx and sky grids updated accordingly.
.PREVIOUS DISCUSSION.
.NEAR TERM [Through 10 am Thursday...
The large scale longwave pattern during the pre-dawn hours was
highlighted by ridging over Wrn states and very broad troughing
over Ern states with decreasing amplitude from N-S leaving near
zonal flow over NE Gulf region. Weak shortwave moving across local
area. At the surface, weak surface wave over local area with
trough or warm frontal boundary bisecting the area SWWD into Gulf
of Mex. Local radars show area of light rain and drizzle along and
east of low/trough aided by shortwave, that is across Ern half of
our area.
For the remainder of tonight into this morning, as shortwave
exits Ewd, the low and trough will continue to move ESE with
decreasing rain and drizzle from exiting SEWD. This reflected well
in local WRF which has last rain exiting SE Big Bend 13z-14z. Main
immediate concern is fog resulting from combination of boundary,
high dew points and shrinking dew point depressions, drizzle, moist
ground and near calm winds. Local confidence tool and SREF
back up fog concerns. The main focus will be west of the
Apalachicola where decreasing clouds will favor fog vs stratus. Will
monitor closely in case Dense Fog Advisory is needed. Ern areas
under ample cloud cover will lean more towards low status. Even
after the rain ends, areas of fog will linger into mid morning.
&&
.SHORT TERM [Wednesday Through Thursday Night]...
Aside from a few lingering showers over the southeast Big Bend and
coastal waters, we will see one dry day Wednesday before the next
and stronger shortwave brings rain back to the region. The surface
low with this system is forecast to track east across the southern
portions of Mississippi and Alabama Thursday before crossing south
Georgia and lifting northeastward through the coastal areas of the
Carolina`s Thursday night. A southwestward trailing cold front
will cut about midway through our FA by 12z Friday. PoPs will ramp
up to likely/categorical on Thursday with forecast QPF mostly in
the 0.5" to 1.0" range from Wednesday night through Thursday
night. Min and max temperatures will be above climo.
&&
.LONG TERM [Friday through Tuesday]...
The period begins with zonal flow followed by a building ridge over
the weekend. The ridge flattens locally by late Tuesday as a low
pressure system translates from the Central Plains to just north of
New England. At the surface, a cold front will continue to push
through the CWA Friday with slight to low end chance PoPs. This will
be followed by the passage of a secondary but dry front Friday
night/Saturday morning as high pressure noses down the eastern
seaboard. The weekend will be dry but the next low pressure system
will rapidly lift out of the plains on Sunday into the Great Lakes
Region by Monday night dragging a cold front into the SE CONUS.
There will be a slight chance of rain for most of our CWA Monday.
Rain and possibly thunderstorms will accompany the front as it
pushes across the Tri-state region Tuesday. Temperatures will be
above seasonal levels through the extended period.
&&
.AVIATION...
[Through 00z Thursday]
Overnight low clouds and rain continue as a surface low over the
Gulf slides to the east. Areas behind main cloud deck (KDHN, KABY)
already experiencing fog which will become increasingly dense as
the night goes on. These terminals will have the greatest chance
of being impacted by LIFR fog and ceilings while areas farther to
the south and east and under cloud cover will have vis and
ceilings ranging from IFR to MVFR. After 14z, CIGS and VSBYS will
rise to VFR and should stay VFR. Generally ENE winds 5 to 10 mph
after fog/cigs lift becoming light after sundown.
&&
.MARINE...
A weak area of low pressure will move across or just north of the
local waters tonight with winds gradually veering to become
offshore. Winds should be below headline criteria at least through
Wednesday night. By Thursday, a stronger storm system will approach
from the west with onshore winds briefly increasing to cautionary
levels. Light to moderate winds swing around to become offshore on
Friday and then east to southeast over the weekend.
&&
.FIRE WEATHER...
RH will remain safely above the levels needed to achieve red flag
criteria this week. Dispersion indices will be on the low side on
Wednesday and Thursday. Rain chances will increase once again on
Thursday.
&&
.HYDROLOGY...
Despite increased rain chances this week, rainfall totals are
expected to remain low, with minimal impact on area rivers and
streams.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 57 72 59 76 48 / 30 70 40 20 10
Panama City 61 74 61 70 54 / 30 80 30 20 10
Dothan 58 71 55 71 47 / 30 80 40 20 10
Albany 54 70 55 70 46 / 30 80 50 20 10
Valdosta 55 70 60 75 49 / 10 60 40 30 10
Cross City 54 75 60 76 50 / 20 50 40 30 10
Apalachicola 60 71 61 70 54 / 30 70 40 20 10
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...DENSE FOG ADVISORY until 9 AM CST Wednesday for Calhoun-
Central Walton-Coastal Bay-Holmes-Inland Bay-Inland
Walton-Jackson-South Walton-Washington.
GA...DENSE FOG ADVISORY until 10 AM EST this morning for Baker-
Calhoun-Clay-Decatur-Dougherty-Early-Grady-Lee-Miller-
Mitchell-Quitman-Randolph-Seminole-Terrell.
AL...DENSE FOG ADVISORY until 9 AM CST Wednesday for Coffee-Dale-
Geneva-Henry-Houston.
GM...None.
&&
$$
Block
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
322 AM EST WED FEB 6 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 256 AM EST WED FEB 6 2013
A LARGE AREA OF HIGH PRESSURE WILL BUILD ACROSS CENTRAL INDIANA AND
THE OHIO VALLEY THROUGH TONIGHT. AS THE HIGH MOVES EAST BY
THURSDAY...A LOW PRESSURE SYSTEM AND APPROACHING WARM FRONT WILL
PUSH ACROSS CENTRAL INDIANA. HIGH PRESSURE WILL ARRIVE BACK IN THE
AREA ON FRIDAY AND REMAIN ACROSS THE AREA DURING THE FIRST PART OF
THE WEEKEND. YET ANOTHER WEATHER SYSTEM WILL ARRIVE IN THE AREA ON
SUNDAY AND MONDAY...PROVIDING MORE CHANCES FOR PRECIPITATION.
&&
.NEAR TERM /TODAY/...
ISSUED AT 256 AM EST WED FEB 6 2013
FORECAST PROBLEM FOR THE DAY IS HOW LONG THIS PESKY STRATUS DECK
WHICH IS ENCOMPASSING MUCH OF CENTRAL INDIANA HOLD ON FOR? WHILE
MOST OF THE GUIDANCE INDICATES THIS WILL SCATTER OUT LATER THIS
MORNING...BASED ON TRENDS AM BEGINNING TO DOUBT THIS. THINK THE HRRR
HAS A BETTER HANDLE ON THIS DECK...KEEPING IT AROUND FOR MUCH OF THE
DAY...ACTUALLY UNTIL 20-21Z. IN TERMS OF THE FORECAST...HELD ONTO
THE OVERCAST CLOUDS UNTIL LATE THIS MORNING AND BEGIN PARTLY CLOUDY
BY 18Z. NOTE THIS DOES NOT APPLY FOR THE SW CORNER FOR FA WHERE
CLOUDS HAVE SCATTERED OUT IN THE LAST HOUR. SKIES LOOK TO GO BKN
EARLY THIS EVENING.
WENT CLOSER TO THE SLIGHTLY COOLER MAV GUIDANCE FOR TEMPS TODAY AS
CLOUDS LINGER INTO THE DAY. HIGH 32(NE) TO 42(SW).
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
ISSUED AT 256 AM EST WED FEB 6 2013
FORECAST FOCUS IS ON CHANCES FOR PRECIPITATION THURSDAY/THURSDAY
NIGHT. MODELS ARE CLOSE ENOUGH THAT A BLEND WAS UTILIZED.
HIGH PRESSURE WILL PROVIDE DRY CONDITIONS THROUGH TONIGHT.
THE NEXT COLD FRONT WILL MOVE IN LATER IN THE DAY THURSDAY AS
LATEST MODEL RUNS HAVE BEEN HINTING AT THIS LATER TIMING AND THE
TRENDS CONTINUES. AGAIN...FORCING IS NOT THAT IMPRESSIVE SO ONLY
WENT CHANCE POPS ACROSS THE AREA THU AFTERNOON...THEN A BRIEF
PERIOD OF LIKELY RAIN WITH LOWERING POPS BACK TO CHANCE BY
MIDNIGHT. APPEARS PRECIP TYPE WILL NOT BE AN ISSUE UNTIL LATE
THURSDAY NIGHT SOME RAIN/SNOW MIX IS POSSIBLE ON THE BACK SIDE OF
SYSTEM. QPF AMOUNTS LOOK VERY MINIMAL. NO MORE THAN A QUARTER OF
AN INCH AT BEST OVERALL FOR ENTIRE EVENT.
HIGH PRESSURE WILL ARRIVE IN THE AREA ON FRIDAY AND REMAIN ACROSS
THE AREA DURING THE FIRST PART OF THE WEEKEND...PROVIDING DRY AND
NEAR NORMAL TEMPERATURES.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
ISSUED AT 256 AM EST WED FEB 6 2013
ENSEMBLE DATA INDICATE A SPLIT FLOW ACROSS THE COUNTRY DURING THIS
PERIOD...WITH AN UPPER LOW CUTTING OFF OVER THE SOUTHERN ROCKIES.
THE DATA CONTINUE TO KEY IN ON SUNDAY AND MONDAY BEING THE MAIN TIME
FRAME FOR A PRECIPITATION THREAT AS UPPER ENERGY IN THE NORTHERN
STREAM DROPS INTO THE MIDWEST AND GREAT LAKES COMBINED WITH A PIECE
OF ENERGY EJECTING OUT OF THE SOUTHWESTERN UPPER LOW. JUST ABOUT ALL
THE ENSEMBLE MEMBERS AGREE THAT THE LOCAL AREA WILL BE ON THE WARM
SIDE OF THIS SYSTEM...SO EXPECTING RAIN FOR THE MOST PART. WILL
CONTINUE TO HIGHLIGHT POPS ON SUNDAY AND MONDAY.
&&
.AVIATION /DISCUSSION FOR 060900Z KIND TAF UPDATE/...
ISSUED AT 322 AM WED FEB 6 2013
MVFR CEILINGS 015-020 HAVE BEEN HOLDING ACROSS THE AREA OVER THE
PAST COUPLE OF HOURS...WITH LITTLE EVIDENCE THAT THESE CEILINGS WILL
BREAK UP ANYTIME SOON. CHANCES OF THIS DECK MIXING OUT APPEARS TO BE
DIMINISHING WITH LOW LEVEL FLOW WEAKENING WITH THE APPROACH OF THE
SURFACE RIDGE.
WILL BACK OFF ON THE DISSIPATION OF THE MVFR CEILINGS TO THE
AFTERNOON HOURS ON THE UPDATE. SURFACE WINDS SHOULD DIMINISH TO
BELOW 7 KTS OVER THE NEXT SEVERAL HOURS. PREVIOUS DISCUSSION
FOLLOWS.
MVFR CLOUD DECK HAS REACHED ALL THE SITES AND WILL CONTINUE FOR
THE NEXT FEW HOURS. RAP 900MB RH PROGS MIMIC THE CLOUD DECK FAIRLY
WELL AND SHOW THEM CLEARING OUT FROM THE SOUTHWEST AROUND 9-10Z AT
ALL SITES BUT KLAF...WHERE THEY HANG ON INTO THE MORNING. WIND
GUSTS OF 15-20 KTS OVER KIND AND KHUF SHOULD END BY 8Z AND
SUSTAINED WINDS AFTER THAT WILL BE AROUND 5 KTS OUT OF THE
NORTHWEST BEFORE BECOMING MORE LIGHT AND VARIABLE AROUND DAYBREAK.
VISIBILITIES COULD FALL TO MVFR AS WINDS LIGHTEN AS WELL...BUT
SHOULD NOT DROP ANY FURTHER DUE TO THE AMOUNT OF TIME THE CLOUDS
HAVE STUCK AROUND. WIND DIRECTION SHOULD CHANGE TO SOUTHEAST BY
MIDDAY WEDNESDAY BUT SPEEDS SHOULD REMAIN LIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....JAS
AVIATION...CP/JAS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
305 AM EST WED FEB 6 2013
.UPDATE...
THE SYNOPSIS...NEAR TERM...SHORT TERM AND LONG TERM SECTIONS HAVE
BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 256 AM EST WED FEB 6 2013
A LARGE AREA OF HIGH PRESSURE WILL BUILD ACROSS CENTRAL INDIANA AND
THE OHIO VALLEY THROUGH TONIGHT. AS THE HIGH MOVES EAST BY
THURSDAY...A LOW PRESSURE SYSTEM AND APPROACHING WARM FRONT WILL
PUSH ACROSS CENTRAL INDIANA. HIGH PRESSURE WILL ARRIVE BACK IN THE
AREA ON FRIDAY AND REMAIN ACROSS THE AREA DURING THE FIRST PART OF
THE WEEKEND. YET ANOTHER WEATHER SYSTEM WILL ARRIVE IN THE AREA ON
SUNDAY AND MONDAY...PROVIDING MORE CHANCES FOR PRECIPITATION.
&&
.NEAR TERM /TODAY/...
ISSUED AT 256 AM EST WED FEB 6 2013
FORECAST PROBLEM FOR THE DAY IS HOW LONG THIS PESKY STRATUS DECK
WHICH IS ENCOMPASSING MUCH OF CENTRAL INDIANA HOLD ON FOR? WHILE
MOST OF THE GUIDANCE INDICATES THIS WILL SCATTER OUT LATER THIS
MORNING...BASED ON TRENDS AM BEGINNING TO DOUBT THIS. THINK THE HRRR
HAS A BETTER HANDLE ON THIS DECK...KEEPING IT AROUND FOR MUCH OF THE
DAY...ACTUALLY UNTIL 20-21Z. IN TERMS OF THE FORECAST...HELD ONTO
THE OVERCAST CLOUDS UNTIL LATE THIS MORNING AND BEGIN PARTLY CLOUDY
BY 18Z. NOTE THIS DOES NOT APPLY FOR THE SW CORNER FOR FA WHERE
CLOUDS HAVE SCATTERED OUT IN THE LAST HOUR. SKIES LOOK TO GO BKN
EARLY THIS EVENING.
WENT CLOSER TO THE SLIGHTLY COOLER MAV GUIDANCE FOR TEMPS TODAY AS
CLOUDS LINGER INTO THE DAY. HIGH 32(NE) TO 42(SW).
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
ISSUED AT 256 AM EST WED FEB 6 2013
FORECAST FOCUS IS ON CHANCES FOR PRECIPITATION THURSDAY/THURSDAY
NIGHT. MODELS ARE CLOSE ENOUGH THAT A BLEND WAS UTILIZED.
HIGH PRESSURE WILL PROVIDE DRY CONDITIONS THROUGH TONIGHT.
THE NEXT COLD FRONT WILL MOVE IN LATER IN THE DAY THURSDAY AS
LATEST MODEL RUNS HAVE BEEN HINTING AT THIS LATER TIMING AND THE
TRENDS CONTINUES. AGAIN...FORCING IS NOT THAT IMPRESSIVE SO ONLY
WENT CHANCE POPS ACROSS THE AREA THU AFTERNOON...THEN A BRIEF
PERIOD OF LIKELY RAIN WITH LOWERING POPS BACK TO CHANCE BY
MIDNIGHT. APPEARS PRECIP TYPE WILL NOT BE AN ISSUE UNTIL LATE
THURSDAY NIGHT SOME RAIN/SNOW MIX IS POSSIBLE ON THE BACK SIDE OF
SYSTEM. QPF AMOUNTS LOOK VERY MINIMAL. NO MORE THAN A QUARTER OF
AN INCH AT BEST OVERALL FOR ENTIRE EVENT.
HIGH PRESSURE WILL ARRIVE IN THE AREA ON FRIDAY AND REMAIN ACROSS
THE AREA DURING THE FIRST PART OF THE WEEKEND...PROVIDING DRY AND
NEAR NORMAL TEMPERATURES.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
ISSUED AT 256 AM EST WED FEB 6 2013
ENSEMBLE DATA INDICATE A SPLIT FLOW ACROSS THE COUNTRY DURING THIS
PERIOD...WITH AN UPPER LOW CUTTING OFF OVER THE SOUTHERN ROCKIES.
THE DATA CONTINUE TO KEY IN ON SUNDAY AND MONDAY BEING THE MAIN TIME
FRAME FOR A PRECIPITATION THREAT AS UPPER ENERGY IN THE NORTHERN
STREAM DROPS INTO THE MIDWEST AND GREAT LAKES COMBINED WITH A PIECE
OF ENERGY EJECTING OUT OF THE SOUTHWESTERN UPPER LOW. JUST ABOUT ALL
THE ENSEMBLE MEMBERS AGREE THAT THE LOCAL AREA WILL BE ON THE WARM
SIDE OF THIS SYSTEM...SO EXPECTING RAIN FOR THE MOST PART. WILL
CONTINUE TO HIGHLIGHT POPS ON SUNDAY AND MONDAY.
&&
.AVIATION /DISCUSSION FOR 060600Z TAF ISSUANCE/...
ISSUED AT 1117 PM EST TUE FEB 5 2013
MVFR CLOUD DECK HAS REACHED ALL THE SITES AND WILL CONTINUE FOR
THE NEXT FEW HOURS. RAP 900MB RH PROGS MIMIC THE CLOUD DECK FAIRLY
WELL AND SHOW THEM CLEARING OUT FROM THE SOUTHWEST AROUND 9-10Z AT
ALL SITES BUT KLAF...WHERE THEY HANG ON INTO THE MORNING. WIND
GUSTS OF 15-20 KTS OVER KIND AND KHUF SHOULD END BY 8Z AND
SUSTAINED WINDS AFTER THAT WILL BE AROUND 5 KTS OUT OF THE
NORTHWEST BEFORE BECOMING MORE LIGHT AND VARIABLE AROUND DAYBREAK.
VISIBILITIES COULD FALL TO MVFR AS WINDS LIGHTEN AS WELL...BUT
SHOULD NOT DROP ANY FURTHER DUE TO THE AMOUNT OF TIME THE CLOUDS
HAVE STUCK AROUND. WIND DIRECTION SHOULD CHANGE TO SOUTHEAST BY
MIDDAY WEDNESDAY BUT SPEEDS SHOULD REMAIN LIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....JAS
AVIATION...CP
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1123 PM EST TUE FEB 5 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 239 PM EST TUE FEB 5 2013
A QUICK MOVING AREA OF LOW PRESSURE WILL DEPART THE GREAT LAKES
THIS EVENING ALLOWING A LARGE AREA OF HIGH PRESSURE OVER THE
CENTRAL PLAINS TO BUILD ACROSS CENTRAL INDIANA AND THE OHIO VALLEY
THROUGH WEDNESDAY AND WEDNESDAY NIGHT. THIS WILL RESULT IN DRY AND
SLIGHTLY BELOW NORMAL TEMPERATURES.
AS THE HIGH MOVES EAST BY THURSDAY...A LOW PRESSURE SYSTEM AND
APPROACHING WARM FRONT WILL PUSH ACROSS CENTRAL
INDIANA...RESULTING IN CHANCES FOR RAIN...MAINLY DURING THE
AFTERNOON HOURS.
HIGH PRESSURE WILL ARRIVE IN THE AREA ON FRIDAY AND REMAIN ACROSS
THE AREA DURING THE FIRST PART OF THE WEEKEND...PROVIDING DRY AND
NEAR NORMAL TEMPERATURES.
YET ANOTHER WEATHER SYSTEM WILL ARRIVE IN THE AREA ON SUNDAY AND
MONDAY...PROVIDING MORE CHANCES FOR PRECIPITATION.
&&
.NEAR TERM /OVERNIGHT/...
ISSUED AT 954 PM EST TUE FEB 5 2013
FEW FLURRIES HAVE DRIFTED THROUGH THE METRO OVER THE LAST HOUR OR
SO. RADAR SHOWS A DIMINISHING TREND TO FLURRIES AS THEY HAVE
SHIFTED EAST OF INDIANAPOLIS. WITH SUCH LITTLE COVERAGE
LEFT...WILL NOT MAKE ANY MENTION OF FLURRIES GOING FORWARD FOR THE
NIGHT.
STRATUS DECK ON THE OTHER HAND IS HOLDING ITS OWN OVER MUCH OF THE
FORECAST AREA AS CYCLONIC FLOW SETS UP ACROSS THE REGION FOR THE
OVERNIGHT. BACK EDGE OF THE LOWER CLOUDS MAKING QUICK PROGRESS
ALREADY INTO WESTERN ILLINOIS AS OF 0130Z BUT AS LOW LEVEL FLOW
VEERS TO A MORE NORTHWEST DIRECTION OVER THE NEXT FEW HOURS...
ANTICIPATE BACK EDGE OF CLOUD DECK WILL SLOW A BIT. MODEL
SOUNDINGS AND LOW LEVEL RH PROGS SUPPORT THIS THINKING...AND WILL
MAINTAIN CLOUDY CONDITIONS FOR ALL BUT THE SOUTHWEST THIRD OF THE
FORECAST AREA THROUGH THE NEXT SEVERAL HOURS WITH SOME CLEARING
TOWARDS DAYBREAK. WITH MORE CLOUDS EXPECTED THAN PREVIOUSLY
THOUGHT AND BASED ON CURRENT TEMPS THIS EVENING...BUMPED UP
OVERNIGHT LOWS BY A COUPLE DEGREES ACROSS THE ENTIRE FORECAST AREA.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
ISSUED AT 239 PM EST TUE FEB 5 2013
MAIN WEATHER CHALLENGE DURING THIS PERIOD WILL BE LOW PRESSURE
SYSTEM AND ASSOCIATED POPS ON THURSDAY AFTERNOON AND THURSDAY
NIGHT.
DRY WEATHER IS EXPECTED ON WEDNESDAY AND WEDNESDAY NIGHT AS ZONAL
FLOW TO SUBTLE RIDGING WILL CONTINUE TO PASS ACROSS THE AREA WITH
HIGH PRESSURE PASSING ACROSS THE OHIO VALLEY. TIME HEIGHT SECTIONS
CONTINUE TO SHOW SUBSIDENCE DURING THIS PERIOD ALONG WITH LIMITED
MOISTURE. WITH UNREACHABLE CONVECTIVE TEMPERATURES...AGAIN JUST
SOME PASSING HIGH CLOUDS WILL BE EXPECTED..THUS PARTLY CLOUDY
AGAIN. GOOD WARM AIR ADVECTION RETURNS ON WEDNESDAY AND WEDNESDAY
NIGHT. THUS WILL TREND TO WARMER SIDE OF A MAVMOS/METMOS BLEND FOR
HIGHS AND LOWS.
WARM AIR ADVECTION IS EXPECTED TO CONTINUE ON THURSDAY AHEAD OF A
DEEPENING SHORT WAVE THAT WILL BE PUSHING TOWARD AND ACROSS THE
REGION ON THURSDAY AFTERNOON AND THURSDAY NIGHT. BY THURSDAY
AFTERNOON AND THURSDAY NIGHT...FORECAST SOUNDINGS BEGIN TO SHOW
DEEP SATURATION BY 00Z FRIDAY. WITH A WARM AND MOIST SOUTHERLY
FLOW IN PLACE AHEAD OF THE TROUGH...AND GOOD DYNAMICS THAT APPEAR
IN PLACE...INGREDIENTS FOR A PRECIP EVENT LOOK PRETTY GOOD. LOWER
LEVELS OF THE FORECAST SOUNDINGS ARE WELL ABOVE FREEZING...SO NO
PRECIPITATION TYPE ISSUES. WILL TREND TOWARD HIGHER POPS DURING
THE AFTERNOON AND AND THURSDAY EVENING PERIODS. GIVEN THE EXPECTED
WAA AND PRECIP DURING THE LATE AFTERNOON WILL STICK TO THE WARMER
SIDE A MAVMOS FOR THURSDAY HIGHS AS THERE SHOULD BE PLENTY OF TIME
FOR HEATING PRIOR TO PRECIP ONSET. WITH COLD FRONTAL PASSAGE
EXPECTED ON THURSDAY NIGHT WILL STICK CLOSE TO MAVMOS LOWS FOR NOW
AS SOME UNCERTAINTY REMAINS REGARDING HOW QUICKLY THE COLDER AIR
MAY ARRIVE.
ON FRIDAY...FORECAST SOUNDINGS DRY OUT DRAMATICALLY AS A LARGE
AREA OF COLD...CANADIAN HIGH PRESSURE BUILDS ACROSS THE
REGION...SETTLING FROM THE UPPER MIDWEST. FORECAST SOUNDINGS HINT
AT SOME TRAPPED STRATOCU...THUS PARTLY TO MOSTLY CLOUDY SHOULD
WORK FINE. WILL LEAN COLDER THAN MEXMOS HIGHS GIVE THE COLD POLAR
CONTINENTAL AIR MASS THAT SHOULD BE IN PLACE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
ISSUED AT 208 PM EST TUE FEB 5 2013
MODELS ARE CLOSE ENOUGH THAT THE ALLBLEND INITIALIZATION CAN BE
USED FOR MOST ITEMS.
DRY WEATHER WILL PERSIST INTO SATURDAY NIGHT ACROSS THE AREA AS
HIGH PRESSURE MOVES ACROSS THE AREA. BASED ON LATEST MODEL TRENDS
HAVE REMOVED ALLBLENDS SLIGHT CHANCE POPS ACROSS THE WEST ON
SATURDAY NIGHT.
AS A SYSTEM MOVES ACROSS THE AREA SUNDAY AND MONDAY RAIN WILL
BECOME LIKELY. HAVE ACCEPTED ALLBLEND POPS HERE. MODELS ARE
TRENDING DRIER ON MONDAY NIGHT...SO WENT DRY THERE AS WELL.
TUESDAY WILL BE DRY WITH HIGH PRESSURE RETURNING.
TEMPERATURES THROUGH THE PERIOD WILL BE NEAR TO ABOVE AVERAGE.
&&
.AVIATION /DISCUSSION FOR 060600Z TAF ISSUANCE/...
ISSUED AT 1117 PM EST TUE FEB 5 2013
MVFR CLOUD DECK HAS REACHED ALL THE SITES AND WILL CONTINUE FOR
THE NEXT FEW HOURS. RAP 900MB RH PROGS MIMIC THE CLOUD DECK FAIRLY
WELL AND SHOW THEM CLEARING OUT FROM THE SOUTHWEST AROUND 9-10Z AT
ALL SITES BUT KLAF...WHERE THEY HANG ON INTO THE MORNING. WIND
GUSTS OF 15-20 KTS OVER KIND AND KHUF SHOULD END BY 8Z AND
SUSTAINED WINDS AFTER THAT WILL BE AROUND 5 KTS OUT OF THE
NORTHWEST BEFORE BECOMING MORE LIGHT AND VARIABLE AROUND DAYBREAK.
VISIBILITIES COULD FALL TO MVFR AS WINDS LIGHTEN AS WELL...BUT
SHOULD NOT DROP ANY FURTHER DUE TO THE AMOUNT OF TIME THE CLOUDS
HAVE STUCK AROUND. WIND DIRECTION SHOULD CHANGE TO SOUTHEAST BY
MIDDAY WEDNESDAY BUT SPEEDS SHOULD REMAIN LIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...PUMA
NEAR TERM...RYAN
SHORT TERM...PUMA
LONG TERM....50
AVIATION...CP
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
354 AM CST WED FEB 6 2013
...UPDATED FOR LONG TERM DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 133 PM CST TUE FEB 5 2013
TONIGHT:
UPPER LEVEL RIDGING WILL CONTINUE THIS AFTERNOON, ALTHOUGH THE RIDGE WILL
FLATTEN OUT LATE TONIGHT AS A SHORTWAVE TROF MOVES ACROSS THE NORTHERN
PLAINS. AT THE SURFACE, WINDS WILL EVENTUALLY BECOME SOUTHERLY THIS
EVENING AND HIGHER DEWPOINTS WILL CONTINUE TO SLOWLY ADVECT NORTHWARD
FROM TEXAS, ACROSS WESTERN OKLAHOMA, AND EVENTUALLY ACROSS HALF OF THE
REGION BY TOMORROW AFTERNOON. THE 12Z NAM IS SUGGESTING DENSE FOG TOMORROW
MORNING AS A WARM FRONT MOVES NORTH. THINK THIS IS OVERDONE AS RAP/SREF
/ARW-WRF KEEP THE DENSE FOG SOUTH. ADDED PATCHY FOG NEAR THE OKLAHOMA
BORDER WHERE BOUNDARY LAYER MOISTURE WILL BE HIGHER. OTHERWISE, WE WILL
SEE HIGHER MINIMUMS AS WARM AIR ADVECTION CONTINUES OVERNIGHT - GENERALLY
IN THE UPPER 20S AND LOWER 30S DEG F.
TOMORROW:
TOMORROW WILL BE A WARM DAY AS WARM AIR ADVECTION STRENGTHENS AHEAD
OF AN APPROACHING COLD FRONT. 850 HPA TEMPERATURES INCREASE TO AROUND
15 DEG C ACROSS FAR SW KANSAS IN ASSOCIATION WITH THE WARM AIR ADVECTION
REGIME. WE COULD SEE A FEW LOCATIONS REACH NEAR 70 DEG F IN THIS AREA
TOMORROW. OTHERWISE, MAXIMUM TEMPERATURES ELSEWHERE WILL BE IN THE 60S
DEG F. TOMORROW WILL ALSO BE BREEZY AS 20-30 KT 850 HPA WINDS ARE FORECAST
AND THESE WINDS WILL MIX DOWN A BIT. LASTLY, NO PRECIPITATION IS EXPECTED
DURING MY PERIOD AS FORCING WON`T ARRIVE UNTIL LATER IN THE EVENING.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 352 AM CST WED FEB 6 2013
THE SHORTWAVE TROUGH MENTIONED IN THE SHORT TERM DISCUSSION WILL
PROGRESS INTO EASTERN KANSAS BY THURSDAY AFTERNOON AND HELP TO
PUSH A COLD FRONT THROUGH SOUTHWEST KANSAS IN THE MORNING. THUS,
HIGH TEMPERATURES SHOULD BE A LITTLE COOLER IN THE 50S. THE LOW
LEVEL MOISTURE THAT WILL HAVE ADVECTED INTO SOUTHERN KANSAS
WEDNESDAY NIGHT WILL BE SHUNTED BACK TO THE GULF COAST BY THURSDAY
AFTERNOON. MEANWHILE, A DEEP UPPER LEVEL TROUGH WILL BE PROGRESSING
SOUTHEASTWARD AND AMPLIFYING ALONG THE WEST COAST. BY FRIDAY, THIS
UPPER LEVEL TROUGH WILL BE LOCATED OVER THE SOUTHERN SECTIONS OF
CALIFORNIA AND NEVADA. A SURFACE TROUGH WILL DEVELOP IN THE LEE OF
THE ROCKIES BY FRIDAY IN RESPONSE TO THE SOUTHWESTERLY MID-LEVEL FLOW
ACROSS THE ROCKIES AHEAD OF THE SYSTEM. BUT THE LOW LEVEL MOISTURE
WILL STILL BE TRAPPED IN SOUTH TEXAS AT THIS TIME. HIGH TEMPERATURES
OUGHT TO REACH THE 50S AGAIN ON FRIDAY.
BY FRIDAY NIGHT AS THE WESTERN TROUGH EDGES INTO UTAH AND ARIZONA, THE
LOW LEVEL FLOW WILL INCREASE FROM THE GULF OF MEXICO INTO THE
SOUTHERN PLAINS. BUT EVEN BY 12Z SATURDAY, THE LOW STRATUS AND GULF
MOISTURE WILL STILL BE WELL TO THE SOUTH. THIS WILL ALLOW FOR RADIATIONAL
COOLING, WITH LOWS IN THE 30S SATURDAY MORNING. ON SATURDAY, THE
UPPER TROUGH WILL PROGRESS EASTWARD, WITH MID LEVEL COOLING
APPROACHING FAR WESTERN KANSAS BY EVENING. STRATUS SHOULD DEVELOP
DURING THE DAY OVER SOUTHWEST KANSAS AS THE LOW LEVEL MOISTURE MOVES
NORTHWARD INTO A FAIRLY COOL AIRMASS. A FEW SHOWERS MAY DEVELOP IN
THE AFTERNOON AS WARM ADVECTION INCREASES IN THE WARM SECTOR. BY
LATE AFTERNOON, SOME CLEARING MAY OCCUR IN FAR WESTERN KANSAS. THIS
MAY ALLOW FOR SOME DAYTIME HEATING AND ENOUGH SURFACE BASED CAPE FOR
THUNDERSTORM DEVELOPMENT ALONG THE DRYLINE. AS ONE WOULD EXPECT THIS TIME
OF YEAR, INSTABILITY WILL BE A MAJOR LIMITING FACTOR DESPITE STRONG
SHEAR. BUT SOME SMALL HAIL CANNOT BE RULED OUT GIVEN THE EXPECTED
COLD 500MB TEMPERATURES (-20C) AND 40-45F SURFACE DEWPOINTS ON THE
HIGHER TERRAIN. ANY STORMS THAT DEVELOP WILL PROGRESS EASTWARD
ACROSS THE REMAINDER OF SOUTHWEST KANSAS SATURDAY NIGHT IN A
WEAKENED STATE. AS THIS SHORTWAVE TROUGH PASSES TO THE NORTHEAST BY
SUNDAY MORNING, THE ASSOCIATED COLD FRONT WILL MOVE THROUGH WESTERN
KANSAS. BUT THIS WILL NOT BE A CANADIAN OR ARCTIC AIRMASS, SO HIGH
TEMPERATURES SHOULD STILL REACH INTO THE UPPER 30S TO LOWER 50S ON
SUNDAY, WITH THE WARMEST READINGS IN SOUTH CENTRAL KANSAS. ANOTHER
UPPER LEVEL TROUGH WILL PROGRESS SOUTHWARD OUT OF CANADA BY
MONDAY, BUT HAVE LIMITED MOISTURE TO WORK WITH IN THE WAKE OF THE
PREVIOUS STRONG SYSTEM. TEMPERATURES SHOULD REMAIN ON THE COOL SIDE
WITH HIGHS IN THE 40S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1141 PM CST TUE FEB 5 2013
NEW RAP MODEL CONTINUES TO SHOW LOW STRATUS AND FOG WITH IFR
CONDITIONS TO RAPIDLY SPREAD NORTH EARLY THIS MORNING FROM
OKLAHOMA AND TEXAS. WILL BRING IN IFR CONDITIONS FROM 14-17Z
AT KDDC AND FROM 17-19Z AT KHYS. AT KGCK IT LOOKS LIKE THE STRATUS
MAY JUST MISS TO THE EAST. SOUTH WINDS THEN ARE FORECAST AT
15-25KT WITH THE STRATUS TRYING TO BREAK INTO THE AFTERNOON. A
COLD FRONT WILL MOVE INTO WESTERN KANSAS IN THE EVENING WITH FROPA
AROUND 02-04Z FROM KGCK TO KHYS, THEN AROUND 05-07Z AT KDDC. A FEW
THUNDERSTORM MAY ALSO DEVELOP ALONG THE FROPA MAINLY AFTER 06Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 65 37 55 28 / 10 20 10 0
GCK 67 33 53 28 / 0 0 0 0
EHA 69 32 54 28 / 0 0 0 0
LBL 69 35 54 28 / 0 0 0 0
HYS 62 36 54 28 / 10 20 0 0
P28 64 43 57 31 / 10 70 50 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SUGDEN
LONG TERM...FINCH
AVIATION...KRUSE
AREA FORECAST DISCUSSION
NWS GOODLAND KS
230 AM MST WED FEB 6 2013
.SHORT TERM...(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 230 AM MST WED FEB 6 2013
TODAY-TONIGHT...CURRENTLY WATCHING A LARGE AREA OF LOW CLOUDS
MOVING TOWARD THE KS/OK BORDER. VISIBILITIES WITHIN THE LOW CLOUDS
ARE AS LOW AS 1/4 MILE. 06Z RUC/NAM HAVE A GOOD HANDLE ON THIS AND
THE AIRMASS NORTHWARD TOWARD OUR FAR EAST/SOUTHEAST COUNTIES BY
15Z THEN SLOWLY EAST THROUGH THE REST OF THE DAY AS A WIND SHIFT
TO THE NORTH MOVES IN FROM THE NORTHWEST. WILL WAIT TIL JUST
BEFORE ZONE ISSUANCE TO SEE WHAT 09Z RUC/07Z HRRR HAVE...MAY NEED
TO BEEF UP THE CLOUDS AND ADD SOME FOG. OTHERWISE SHOULD SEE
PLENTY OF SUN THIS MORNING BEFORE MID AND HIGH CLOUDS MOVE IN FROM
THE WEST AHEAD OF AN UPPER TROUGH THIS AFTERNOON. THESE CLOUDS
WILL BE SLOW TO MOVE OUT TONIGHT FROM NORTHWEST TO SOUTHEAST. WILL
ALSO HAVE TO WATCH LOW CLOUD POTENTIAL OUT EAST TIL THE FRONT AND
INCREASING NORTH WINDS CAN PUSH IT OUT OF THE AREA. HIGHS TODAY
UPPER 50S NORTHWEST TO LOW 60S ELSEWHERE. FAR EAST/SOUTHEAST PARTS
OF THE AREA MAY BE COOLER THEN CURRENTLY EXPECTED IF LOW CLOUDS
LINGER LONGER THEN CURRENTLY EXPECTED. LOWS TONIGHT MID 20S
NORTHWEST TO LOW 30S FAR EAST/SOUTHEAST.
THURSDAY-THURSDAY NIGHT...SUNNY DURING THE DAY AND CLEAR DURING
THE NIGHT WITH UPPER FLOW BACKING TO THE SOUTHWEST AS UPPER LOW
MOVES INTO NORTHERN CALIFORNIA/WESTERN NEVADA BY THE END OF THE
PERIOD. HIGHS IN THE LOW 50S WITH LOWS IN THE 20S.
FRIDAY-FRIDAY NIGHT...AS UPPER LOW SLOWLY MOVES TOWARD THE FOUR
CORNERS BY THE END OF THE PERIOD PRESSURE GRADIENT INCREASES
ACROSS THE AREA WITH SOUTH WINDS OF 20 TO 30 MPH AND GUSTY DURING
THE DAY...A BIT LESS DURING THE NIGHT. SHOULD HAVE A MOSTLY SUNNY
SKY WITH HIGHS WARMING A FEW DEGREES INTO THE MID 50S WHILE LOWS
MILD IN THE 30S.
NO PRECIPITATION IS EXPECTED DURING THE PERIOD.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 1150 PM MST TUE FEB 5 2013
MODELS CONTINUE TO COME INTO BETTER AGREEMENT WITH THE WEEKEND
SYSTEM TO START THIS PERIOD. CUT OFF LOW WILL ORGANIZE OVER
COLORADO ON SATURDAY AND DEEPEN AS IT TRACKS ACROSS THE FORECAST
AREA SATURDAY NIGHT AND SUNDAY. GIVEN THAT TRACK...WILL HAVE TO
PAY CLOSE ATTENTION TO THE DRY SLOT WHICH COULD LIMIT
PRECIPITATION CHANCES ACROSS CENTRAL AND SOUTHERN PARTS OF THE
FORECAST AREA. HOWEVER...ROUGHLY THE NORTHWEST HALF COULD
POTENTIALLY SEE A WINTER STORM BEGINNING SATURDAY NIGHT.
PRECIPITATION WILL LIKELY START AS RAIN...WITH A FEW EMBEDDED
THUNDERSTORMS SATURDAY NIGHT...BEFORE CHANGING OVER TO SNOW FROM
WEST TO EAST LATE SATURDAY NIGHT THROUGH SUNDAY MORNING...ALL SNOW
BY SUNDAY AFTERNOON...WINDING DOWN SUNDAY NIGHT. AS THE SURFACE
LOW DEEPENS...NORTHWEST WINDS WILL INCREASE ON SUNDAY RESULTING IN
AREAS OF BLOWING SNOW AND POTENTIAL FOR BLIZZARD CONDITIONS.
MODELS NOT GENERATING A PARTICULARLY LARGE AMOUNT OF SNOW AT THIS
POINT...GENERALLY LESS THAN 6 INCHES WITH HIGHEST AMOUNTS
NORTHWEST. OTHERWISE...SOME LIGHT SNOW MIGHT LINGER INTO MONDAY
FOLLOWED BY DRY CONDITIONS TUESDAY AND WEDNESDAY WITH GRADUALLY
WARMING TEMPERATURES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 230 AM MST WED FEB 6 2013
VFR EXPECTED THROUGH THE PERIOD AT KGLD AND KMCK. JUST A FEW MID
AND HIGH CLOUDS TODAY WITH INCREASING CLOUDINESS TONIGHT AS AN
UPPER TROUGH MOVES ACROSS THE AREA. FOR KGLD SOUTHWEST WINDS
AROUND 10KTS WILL SHIFT TO THE NORTH AT 12-13KTS WITH HIGHER GUSTS
BY 20Z AS A COLD FRONT MOVES THROUGH. NORTH WINDS AROUND 15KTS
WITH HIGHER GUSTS WILL CONTINUE THROUGH THE NIGHT. FOR KMCK LIGHT
SOUTH TO SOUTHWEST WINDS WILL GRADUALLY SHIFT TO THE NORTH UNDER
10KTS BY 22-23Z THEN INCREASE FROM THE NORTH AT 15KTS WITH HIGHER
GUSTS SHORTLY AFTER DARK AND CONTINUE THROUGH MUCH OF THE NIGHT
BEFORE SLOWLY DECREASING TOWARD THE END OF THE TAF PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...99
LONG TERM...024
AVIATION...99
AREA FORECAST DISCUSSION...UPDATED
NWS DODGE CITY KS
1153 PM CST TUE FEB 5 2013
...UPDATED FOR AVIATION...
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 133 PM CST TUE FEB 5 2013
TONIGHT:
UPPER LEVEL RIDGING WILL CONTINUE THIS AFTERNOON, ALTHOUGH THE RIDGE WILL
FLATTEN OUT LATE TONIGHT AS A SHORTWAVE TROF MOVES ACROSS THE NORTHERN
PLAINS. AT THE SURFACE, WINDS WILL EVENTUALLY BECOME SOUTHERLY THIS
EVENING AND HIGHER DEWPOINTS WILL CONTINUE TO SLOWLY ADVECT NORTHWARD
FROM TEXAS, ACROSS WESTERN OKLAHOMA, AND EVENTUALLY ACROSS HALF OF THE
REGION BY TOMORROW AFTERNOON. THE 12Z NAM IS SUGGESTING DENSE FOG TOMORROW
MORNING AS A WARM FRONT MOVES NORTH. THINK THIS IS OVERDONE AS RAP/SREF
/ARW-WRF KEEP THE DENSE FOG SOUTH. ADDED PATCHY FOG NEAR THE OKLAHOMA
BORDER WHERE BOUNDARY LAYER MOISTURE WILL BE HIGHER. OTHERWISE, WE WILL
SEE HIGHER MINIMUMS AS WARM AIR ADVECTION CONTINUES OVERNIGHT - GENERALLY
IN THE UPPER 20S AND LOWER 30S DEG F.
TOMORROW:
TOMORROW WILL BE A WARM DAY AS WARM AIR ADVECTION STRENGTHENS AHEAD
OF AN APPROACHING COLD FRONT. 850 HPA TEMPERATURES INCREASE TO AROUND
15 DEG C ACROSS FAR SW KANSAS IN ASSOCIATION WITH THE WARM AIR ADVECTION
REGIME. WE COULD SEE A FEW LOCATIONS REACH NEAR 70 DEG F IN THIS AREA
TOMORROW. OTHERWISE, MAXIMUM TEMPERATURES ELSEWHERE WILL BE IN THE 60S
DEG F. TOMORROW WILL ALSO BE BREEZY AS 20-30 KT 850 HPA WINDS ARE FORECAST
AND THESE WINDS WILL MIX DOWN A BIT. LASTLY, NO PRECIPITATION IS EXPECTED
DURING MY PERIOD AS FORCING WON`T ARRIVE UNTIL LATER IN THE EVENING.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 300 PM CST TUE FEB 5 2013
TODAY`S MEDIUM RANGE MODELS ARE FAIRLY SIMILAR TO EACH OTHER AND
PREVIOUS RUNS REGARDING THE SHORTWAVE TROUGH THAT WILL MOVE OUT OVER
THE CENTRAL PLAINS WEDNESDAY NIGHT INTO THURSDAY. UPPER LEVEL
WESTERLY FLOW WILL BE SOMEWHAT SPLIT THROUGH THIS TIME PERIOD. THE
NORTHERN PORTION OF THE WAVE WILL MOVE OUT OVER THE NORTHERN PLAINS
BY THURSDAY MORNING WHILE THE SOUTHERN WEAKER PORTION MOVES OUT
THURSDAY NIGHT. THE UPPER LEVEL DYNAMICS THAT WILL BE IMPACTING THE
WEATHER ACROSS WESTERN KANSAS WILL BE ASSOCIATED WITH THE NORTHERN
PART. AS THE WAVE MOVES OUT, THE AREA WILL COME UNDER THE RIGHT
ENTRANCE REGION OF AN UPPER LEVEL JET. A COLD FRONT WILL BE PUSHING
THROUGH WESTERN KANSAS WEDNESDAY NIGHT. THE BEST CHANCE FOR
THUNDERSTORMS CONTINUES TO BE OVER SOUTH CENTRAL KANSAS WHERE THE
BETTER LOW LEVEL MOISTURE WILL BE. HAVE INCREASED POPS INTO THE
LIKELY CATEGORY FOR THE AREA GENERALLY EAST OF HIGHWAY 183. UPPER
LEVEL RIDGING WILL PUSH INTO THE CENTRAL HIGH PLAINS FAIRLY QUICKLY
BEHIND THE WAVE. THIS SHOULD HELP THE COLD FRONT EAST AND SOUTH OUT
OF THE REGION BY THURSDAY MORNING AND BRING AN END TO ANY
PRECIPITATION CHANCES.
THE MODELS ARE STILL STRUGGLING WITH THE DETAILS OF THE NEXT WAVE
THAT IS PROGGED TO MOVE OUT OVER THE CENTRAL PLAINS THIS WEEKEND.
THE ECMWF CONTINUES TO BE THE MOST PROGRESSIVE IN BRINGING A CLOSED
UPPER LOW OUT OF THE FOUR CORNERS REGION ACROSS FAR NORTHWEST KANSAS
SATURDAY NIGHT. THE 12Z UKMET AND GFS MODELS ARE NOW TRYING TO
FOLLOW SUITE BUT CONTINUE TO BE SLOWER AND SOMEWHAT WEAKER. THE
CANADIAN HAS FLIPPED TO A MORE OPEN WAVE. WITH ALL OF THIS IN MIND,
I STILL DO NOT HAVE MUCH CONFIDENCE IN ANY ONE SOLUTION. FOR THE
MOST PART, HOWEVER, WE SHOULD SEE CHANCES FOR RAIN AND THUNDERSTORMS
INCREASING ON SATURDAY INTO SATURDAY NIGHT. DEPENDING ON THE TRACK
OF THE UPPER LOW, WE COULD SEE LIGHT RAIN OR LIGHT SNOW ESPECIALLY
OVER WEST CENTRAL KANSAS ON SUNDAY INTO SUNDAY NIGHT BEFORE THE
UPPER SYSTEM MOVES OUT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1141 PM CST TUE FEB 5 2013
NEW RAP MODEL CONTINUES TO SHOW LOW STRATUS AND FOG WITH IFR
CONDITIONS TO RAPIDLY SPREAD NORTH EARLY THIS MORNING FROM
OKLAHOMA AND TEXAS. WILL BRING IN IFR CONDITIONS FROM 14-17Z
AT KDDC AND FROM 17-19Z AT KHYS. AT KGCK IT LOOKS LIKE THE STRATUS
MAY JUST MISS TO THE EAST. SOUTH WINDS THEN ARE FORECAST AT
15-25KT WITH THE STRATUS TRYING TO BREAK INTO THE AFTERNOON. A
COLD FRONT WILL MOVE INTO WESTERN KANSAS IN THE EVENING WITH FROPA
AROUND 02-04Z FROM KGCK TO KHYS, THEN AROUND 05-07Z AT KDDC. A FEW
THUNDERSTORM MAY ALSO DEVELOP ALONG THE FROPA MAINLY AFTER 06Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 33 64 36 54 / 0 10 20 0
GCK 30 63 32 52 / 0 0 0 0
EHA 32 66 31 53 / 0 0 0 0
LBL 30 69 33 53 / 0 0 0 0
HYS 31 61 34 53 / 0 10 20 0
P28 35 65 41 56 / 0 10 70 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...GERARD
AVIATION...KRUSE
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
441 AM EST WED FEB 6 2013
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OVER THE AREA TODAY AND PROVIDE A BREAK FROM
SNOW THROUGH THURSDAY. A SURFACE LOW WILL BRING A FRONT WITH A
WINTRY MIX OF PRECIPITATION TO THE AREA THURSDAY NIGHT INTO EARLY
FRIDAY. HIGH PRESSURE WILL THEN RETURN DRY WEATHER FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
A QUICK UPDATE HAS BEEN ISSUED THIS MORNING TO ADD THE MENTION OF
PATCHY FREEZING DRIZZLE ACROSS THE LAUREL HIGHLANDS/ALLEGHENY
FRONT OF MD/WV/PA.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES THE AXIS OF A BROAD
SHORT WAVE TROUGH MOVING INTO THE MID-ATLANTIC. AT 850MB...A
ZONAL FLOW IS VEERING TO MORE WEST-NORTHWESTERLY WITH WEAK CAA IN
THE WAKE OF THE WAVE. WITH THE LOW-LEVEL FLOW PERPENDICULAR TO THE
RIDGES AND A SATURATED 1000-750MB LAYER...UPSLOPING SNOW
ENHANCEMENT IS CONTINUING ACROSS THE RIDGES. AT THE SURFACE...A
BROAD HIGH EXTENDS FROM THE UPPER MIDWEST ACROSS THE MISSOURI
VALLEY AND INTO THE TN VALLEY. THE HIGH IS SLIDING EASTWARD TOWARD
THE UPPER OHIO VALLEY. SUBSIDENCE ASSOCIATED WITH THE HIGH AND NVA
IN THE WAKE OF THE WAVE HAVE ALLOWED FOR SNOW TO COME TO AN END
ACROSS THE LOWLANDS.
TODAY AND TONIGHT...GFS/ECMWF ARE IN AGREEMENT THAT A
WEST-NORTHWESTERLY MID-LEVEL FLOW TODAY WILL BACK TO MORE ZONAL
TONIGHT AND THE SURFACE HIGH WILL MOVE OVER THE AREA. CHANCE POPS
WITH SNOW SHOWERS ARE FORECAST TO CONTINUE EARLY IN UPSLOPING
ACROSS THE RIDGES. DESPITE A COLD WEST-NWRLY 850MB FLOW OFF OF
ERIE...LAKE EFFECT ZONES ARE FORECAST TO BE MOSTLY DRY WITH AN
INVERSION LOWERING TO AROUND 2KFT AFTER A CHANCE OF SNOW SHOWERS
THIS MORNING IN CONVERGENCE ALONG A WIND SHIFT. HIRES MODELS
SUPPORT CHC POPS LINGERING THROUGH THE MORNING ACROSS THE RIDGES
OF THE LAUREL HIGHLANDS AND ALLEGHENY FRONT UNTIL THIS AFTERNOON
WHEN MORE SUBSIDENCE MOVES OVER THE AREA.
FOR TEMPS...HIGHS TODAY LEAN CLOSER TO THE SLIGHTLY WARMER MET
GUIDANCE AS WEAK WAA ADVECTION ENSUES AFTER 18Z. HIGHS WILL RANGE
FROM THE MID 20S ALONG THE I-80 CORRIDOR THE LOWER 30S ACROSS
LOCATIONS SOUTH AND WEST OF THE PITTSBURGH METRO. FOR LOWS ON
WEDNESDAY NIGHT...SOME CLEARING AND NEAR CALM WINDS WILL ALLOW FOR
RADIATIONAL COOLING ACROSS THE AREA. A MAV/MET BLEND WAS USED WITH
LOWS RANGING FROM THE LOWER 20S IN PORTIONS OF EASTERN OHIO TO THE
LOWER TEENS IN VENANGO/CLARION/JEFFERSON COUNTIES.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
A MODEL CONSENSUS INDICATES THAT HIGH PRESSURE WILL PUSH EAST OF THE
AREA ON THURSDAY AS WAA ADVECTION (850MB TEMPS WARMING TO 0-4C)
CONTINUES. WITH A LOW-LEVEL RIDGE SHIFTING EAST OF THE AREA...850MB
FLOW WILL DRY AND SOUTHWESTERLY ON THURSDAY. MID-LEVEL MOISTURE WILL
ADVECT INTO THE AREA TO INCREASE CLOUDINESS AHEAD OF A WEAK SURFACE
LOW ON THURSDAY.
GFS/ECMWF/NAM ALL ARE IN AGREEMENT THAT A TROUGH WILL CROSS THE
GREAT LAKES AND A WEAK SURFACE LOW WILL MOVE INTO WESTERN PA ON
THURSDAY NIGHT. WITH THIS IN MIND...LIKELY POPS ARE FORECAST
THURSDAY NIGHT. THE SURFACE LOW WILL SHIFT EAST OF THE AREA BY 18Z
FRIDAY...WITH A WEAK SHOT OF CAA IN ITS WAKE. WITH WAA ADVECTION
AHEAD OF THE LOW...THE LOW-LEVEL MELTING LAYER AND 1000-850MB
THICKNESS ARE WARM ENOUGH TO BRING RAIN SHOWERS ACROSS MUCH OF THE
AREA THURSDAY NIGHT INTO EARLY FRIDAY. LOCATIONS NORTH OF
PITTSBURGH WILL BE ON THE PERIPHERY OF CRITICAL THICKNESS
THRESHOLDS AND THUS A WINTRY MIX IS FORECAST THERE. SCHC OF
FREEZING RAIN HAS BEEN INCLUDED FOR I-80 CORRIDOR AND LAUREL
HIGHLANDS/ALLEGHENY FRONT AS SFC TEMPS WILL BE NEAR FREEZING IN
THESE LOCATIONS AT THE ONSET OF THE PRECIP. ANY LINGERING
PRECIPITATION WILL CHANGE OVER TO SNOW ON FRIDAY WITH CAA IN A
NORTHERLY FLOW IN THE WAKE OF THE LOW.
TEMPS ARE FORECAST TO BE AROUND 5 DEGREES ABOVE NORMAL AHEAD OF THE
LOW ON THURSDAY INTO EARLY FRIDAY. TEMPS WILL BE NEAR STEADY IN THE
WAKE OF THE LOW ON FRIDAY...RANGING FROM THE MID 30S ACROSS THE I-80
CORRIDOR IN WESTERN PA TO THE LOWER 40S IN EASTERN OHIO...SW
PA...AND NORTH-CENTRAL WV.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
EXCEPT FOR SOME LEFT OVER SNOW FRIDAY EVENING AS THE LOW
DEPARTS...IT APPEARS THAT BOTH SATURDAY AND SUNDAY SHOULD REMAIN
DRY WITH HIGH PRESSURE DOMINATING THE EAST COAST WEATHER. A LARGE
LOW PRESSURE CENTER WILL DEVELOP IN THE CENTRAL PLAINS AND MOVE
INTO MICHIGAN BY MONDAY MORNING...WITH THE FRONTS IMPACTING ALMOST
THE ENTIRE EASTERN UNITED STATES. HAVE GONE AHEAD AND BUMPED UP
POPS TO LIKELY WITH FAIRLY GOOD AGREEMENT BETWEEN 12Z GFS/ECMWF
ALONG WITH NAEFS ENSEMBLE. MOST OF PRECIPITATION SHOULD FALL AS
RAIN...ALTHOUGH SOME SNOW WILL LIKELY MIX IN. SOME LAKE EFFECT
SNOW WILL BE POSSIBLE MONDAY NIGHT BEHIND THE SYSTEM. HAVE ONLY
INCLUDED A SLIGHT CHANCE FOR POPS WITH A SYSTEM MOVING UP THE EAST
COAST ON TUESDAY. TEMPERATURES SHOULD BE NEAR NORMAL VALUES ON
SATURDAY...RISE ABOVE NORMAL ON SUNDAY AND MONDAY...THEN DROP BACK
TO NORMAL ON TUESDAY.
&&
.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
LOWERING OVERCAST STRATOCU CAN BE EXPECTED THIS MORNING IN THE
NORTHWEST FLOW AND BRIEF COLD ADVECTION WITH MVFR CEILINGS
PREVAILING. SOME SNOW FLURRIES ARE POSSIBLE THIS MORNING...MAINLY
AT THE NORTHERN PORTS. BY THIS AFTERNOON WITH WARM ADVECTION AND
RIDGING MOVING INTO THE AREA...STRATOCU WILL SCATTER OUT WITH VFR
CONDITIONS AT ALL PORTS BY LATE AFTERNOON.
.OUTLOOK.../WEDNESDAY NIGHT THROUGH SUNDAY/...
GENERAL VFR CONDITIONS WITH HIGH PRESSURE FOR WEDNESDAY AND
THURSDAY. A STORM THURSDAY NIGHT INTO FRIDAY WILL BRING RESTRICTIONS
IN SNOW WITH RAIN POSSIBLE IN THE SOUTH. HIGH PRESSURE WILL BRING A
RETURN TO VFR FOR THE WEEKEND.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
430 AM EST WED FEB 6 2013
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OVER THE AREA TODAY AND PROVIDE A BREAK FROM
SNOW THROUGH THURSDAY. A SURFACE LOW WILL BRING A FRONT WITH A
WINTRY MIX OF PRECIPITATION TO THE AREA THURSDAY NIGHT INTO EARLY
FRIDAY. HIGH PRESSURE WILL THEN RETURN DRY WEATHER FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES THE AXIS OF A BROAD
SHORT WAVE TROUGH MOVING INTO THE MID-ATLANTIC. AT 850MB...A
ZONAL FLOW IS VEERING TO MORE WEST-NORTHWESTERLY WITH WEAK CAA IN
THE WAKE OF THE WAVE. WITH THE LOW-LEVEL FLOW PERPENDICULAR TO THE
RIDGES AND A SATURATED 1000-750MB LAYER...UPSLOPING SNOW
ENHANCEMENT IS CONTINUING ACROSS THE RIDGES. AT THE SURFACE...A
BROAD HIGH EXTENDS FROM THE UPPER MIDWEST ACROSS THE MISSOURI
VALLEY AND INTO THE TN VALLEY. THE HIGH IS SLIDING EASTWARD TOWARD
THE UPPER OHIO VALLEY. SUBSIDENCE ASSOCIATED WITH THE HIGH AND NVA
IN THE WAKE OF THE WAVE HAVE ALLOWED FOR SNOW TO COME TO AN END
ACROSS THE LOWLANDS.
TODAY AND TONIGHT...GFS/ECMWF ARE IN AGREEMENT THAT A
WEST-NORTHWESTERLY MID-LEVEL FLOW TODAY WILL BACK TO MORE ZONAL
TONIGHT AND THE SURFACE HIGH WILL MOVE OVER THE AREA. CHANCE POPS
WITH SNOW SHOWERS ARE FORECAST TO CONTINUE EARLY IN UPSLOPING
ACROSS THE RIDGES. DESPITE A COLD WEST-NWRLY 850MB FLOW OFF OF
ERIE...LAKE EFFECT ZONES ARE FORECAST TO BE MOSTLY DRY WITH AN
INVERSION LOWERING TO AROUND 2KFT AFTER A CHANCE OF SNOW SHOWERS
THIS MORNING IN CONVERGENCE ALONG A WIND SHIFT. HIRES MODELS
SUPPORT CHC POPS LINGERING THROUGH THE MORNING ACROSS THE RIDGES
OF THE LAUREL HIGHLANDS AND ALLEGHENY FRONT UNTIL THIS AFTERNOON
WHEN MORE SUBSIDENCE MOVES OVER THE AREA.
FOR TEMPS...HIGHS TODAY LEAN CLOSER TO THE SLIGHTLY WARMER MET
GUIDANCE AS WEAK WAA ADVECTION ENSUES AFTER 18Z. HIGHS WILL RANGE
FROM THE MID 20S ALONG THE I-80 CORRIDOR THE LOWER 30S ACROSS
LOCATIONS SOUTH AND WEST OF THE PITTSBURGH METRO. FOR LOWS ON
WEDNESDAY NIGHT...SOME CLEARING AND NEAR CALM WINDS WILL ALLOW FOR
RADIATIONAL COOLING ACROSS THE AREA. A MAV/MET BLEND WAS USED WITH
LOWS RANGING FROM THE LOWER 20S IN PORTIONS OF EASTERN OHIO TO THE
LOWER TEENS IN VENANGO/CLARION/JEFFERSON COUNTIES.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
A MODEL CONSENSUS INDICATES THAT HIGH PRESSURE WILL PUSH EAST OF THE
AREA ON THURSDAY AS WAA ADVECTION (850MB TEMPS WARMING TO 0-4C)
CONTINUES. WITH A LOW-LEVEL RIDGE SHIFTING EAST OF THE AREA...850MB
FLOW WILL DRY AND SOUTHWESTERLY ON THURSDAY. MID-LEVEL MOISTURE WILL
ADVECT INTO THE AREA TO INCREASE CLOUDINESS AHEAD OF A WEAK SURFACE
LOW ON THURSDAY.
GFS/ECMWF/NAM ALL ARE IN AGREEMENT THAT A TROUGH WILL CROSS THE
GREAT LAKES AND A WEAK SURFACE LOW WILL MOVE INTO WESTERN PA ON
THURSDAY NIGHT. WITH THIS IN MIND...LIKELY POPS ARE FORECAST
THURSDAY NIGHT. THE SURFACE LOW WILL SHIFT EAST OF THE AREA BY 18Z
FRIDAY...WITH A WEAK SHOT OF CAA IN ITS WAKE. WITH WAA ADVECTION
AHEAD OF THE LOW...THE LOW-LEVEL MELTING LAYER AND 1000-850MB
THICKNESS ARE WARM ENOUGH TO BRING RAIN SHOWERS ACROSS MUCH OF THE
AREA THURSDAY NIGHT INTO EARLY FRIDAY. LOCATIONS NORTH OF
PITTSBURGH WILL BE ON THE PERIPHERY OF CRITICAL THICKNESS
THRESHOLDS AND THUS A WINTRY MIX IS FORECAST THERE. SCHC OF
FREEZING RAIN HAS BEEN INCLUDED FOR I-80 CORRIDOR AND LAUREL
HIGHLANDS/ALLEGHENY FRONT AS SFC TEMPS WILL BE NEAR FREEZING IN
THESE LOCATIONS AT THE ONSET OF THE PRECIP. ANY LINGERING
PRECIPITATION WILL CHANGE OVER TO SNOW ON FRIDAY WITH CAA IN A
NORTHERLY FLOW IN THE WAKE OF THE LOW.
TEMPS ARE FORECAST TO BE AROUND 5 DEGREES ABOVE NORMAL AHEAD OF THE
LOW ON THURSDAY INTO EARLY FRIDAY. TEMPS WILL BE NEAR STEADY IN THE
WAKE OF THE LOW ON FRIDAY...RANGING FROM THE MID 30S ACROSS THE I-80
CORRIDOR IN WESTERN PA TO THE LOWER 40S IN EASTERN OHIO...SW
PA...AND NORTH-CENTRAL WV.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
EXCEPT FOR SOME LEFT OVER SNOW FRIDAY EVENING AS THE LOW
DEPARTS...IT APPEARS THAT BOTH SATURDAY AND SUNDAY SHOULD REMAIN
DRY WITH HIGH PRESSURE DOMINATING THE EAST COAST WEATHER. A LARGE
LOW PRESSURE CENTER WILL DEVELOP IN THE CENTRAL PLAINS AND MOVE
INTO MICHIGAN BY MONDAY MORNING...WITH THE FRONTS IMPACTING ALMOST
THE ENTIRE EASTERN UNITED STATES. HAVE GONE AHEAD AND BUMPED UP
POPS TO LIKELY WITH FAIRLY GOOD AGREEMENT BETWEEN 12Z GFS/ECMWF
ALONG WITH NAEFS ENSEMBLE. MOST OF PRECIPITATION SHOULD FALL AS
RAIN...ALTHOUGH SOME SNOW WILL LIKELY MIX IN. SOME LAKE EFFECT
SNOW WILL BE POSSIBLE MONDAY NIGHT BEHIND THE SYSTEM. HAVE ONLY
INCLUDED A SLIGHT CHANCE FOR POPS WITH A SYSTEM MOVING UP THE EAST
COAST ON TUESDAY. TEMPERATURES SHOULD BE NEAR NORMAL VALUES ON
SATURDAY...RISE ABOVE NORMAL ON SUNDAY AND MONDAY...THEN DROP BACK
TO NORMAL ON TUESDAY.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
LOWERING OVERCAST STRATOCU CAN BE EXPECTED THIS MORNING IN THE
NORTHWEST FLOW AND BRIEF COLD ADVECTION WITH MVFR CEILINGS
PREVAILING. SOME SNOW FLURRIES ARE POSSIBLE THIS MORNING...MAINLY
AT THE NORTHERN PORTS. BY THIS AFTERNOON WITH WARM ADVECTION AND
RIDGING MOVING INTO THE AREA...STRATOCU WILL SCATTER OUT WITH VFR
CONDITIONS AT ALL PORTS BY LATE AFTERNOON.
.OUTLOOK.../WEDNESDAY NIGHT THROUGH SUNDAY/...
GENERAL VFR CONDITIONS WITH HIGH PRESSURE FOR WEDNESDAY AND
THURSDAY. A STORM THURSDAY NIGHT INTO FRIDAY WILL BRING RESTRICTIONS
IN SNOW WITH RAIN POSSIBLE IN THE SOUTH. HIGH PRESSURE WILL BRING A
RETURN TO VFR FOR THE WEEKEND.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
SHORT TERM...WOODRUM
AVIATION...RSD
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
140 AM EST WED FEB 6 2013
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OVER THE AREA TODAY AND PROVIDE A BREAK FROM
SNOW THROUGH THURSDAY. A SURFACE LOW WILL BRING A FRONT WITH A
WINTRY MIX OF PRECIPITATION TO THE AREA THURSDAY NIGHT INTO EARLY
FRIDAY. HIGH PRESSURE WILL THEN RETURN DRY WEATHER FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE 06Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO
REMOVE POPS ACROSS THE LOWLANDS AND TO ACCOUNT FOR THE LATEST TRENDS
IN TEMPS.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES THE AXIS OF A BROAD
SHORT WAVE TROUGH MOVING INTO CENTRAL PENNSYLVANIA. AT 850MB...A
ZONAL FLOW IS VEERING TO MORE WEST-NORTHWESTERLY WITH WEAK CAA IN
THE WAKE OF THE WAVE. WITH THE LOW-LEVEL FLOW PERPENDICULAR TO THE
RIDGES AND A SATURATED 1000-750MB LAYER...UPSLOPING SNOW
ENHANCEMENT IS CONTINUING ACROSS THE RIDGES. AT THE SURFACE...A
BROAD HIGH EXTENDS FROM THE UPPER MIDWEST ACROSS THE MISSOURI
VALLEY AND INTO THE TN VALLEY. THE HIGH IS SLIDING EASTWARD TOWARD
THE UPPER OHIO VALLEY. SUBSIDENCE ASSOCIATED WITH THE HIGH AND NVA
IN THE WAKE OF THE WAVE HAVE ALLOWED FOR SNOW TO COME TO AN END
ACROSS THE LOWLANDS.
TODAY AND TONIGHT...GFS/ECMWF ARE IN AGREEMENT THAT A
WEST-NORTHWESTERLY MID-LEVEL FLOW TODAY WILL BACK TO MORE ZONAL
TONIGHT AND THE SURFACE HIGH WILL MOVE OVER THE AREA. CHANCE POPS
WITH SNOW SHOWERS ARE FORECAST TO CONTINUE EARLY IN UPSLOPING
ACROSS THE RIDGES. DESPITE A COLD WEST-NWRLY 850MB FLOW OFF OF
ERIE...LAKE EFFECT ZONES ARE FORECAST TO BE MOSTLY DRY WITH AN
INVERSION LOWERING TO AROUND 2KFT AFTER A CHANCE OF SNOW SHOWERS IN
CONVERGENCE ALONG A WIND SHIFT. HIRES MODELS SUPPORT CHC POPS
LINGERING THROUGH THE MORNING ACROSS THE RIDGES OF THE LAUREL
HIGHLANDS AND ALLEGHENY FRONT UNTIL THIS AFTERNOON WHEN MORE
SUBSIDENCE MOVES OVER THE AREA.
FOR TEMPS...HIGHS TODAY LEAN CLOSER TO THE SLIGHTLY WARMER MET
GUIDANCE AS WEAK WAA ADVECTION ENSUES AFTER 18Z. HIGHS WILL RANGE
FROM THE MID 20S ALONG THE I-80 CORRIDOR THE LOWER 30S ACROSS
LOCATIONS SOUTH AND WEST OF THE PITTSBURGH METRO. FOR LOWS ON
WEDNESDAY NIGHT...SOME CLEARING AND NEAR CALM WINDS WILL ALLOW FOR
RADIATIONAL COOLING ACROSS THE AREA. A MAV/MET BLEND WAS USED WITH
LOWS RANGING FROM THE LOWER 20S IN PORTIONS OF EASTERN OHIO TO THE
LOWER TEENS IN VENANGO/CLARION/JEFFERSON COUNTIES.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL BE SHIFTING OFF EARLY THURSDAY. FORECAST WILL
BE COMPLICATED THURSDAY NIGHT INTO FRIDAY MORNING WITH TWO SYSTEMS
COMBINING. OPEN WAVE ACROSS INDIANA THURSDAY EVENING IS EXPECTED
TO BECOME A CLOSED LOW PRESSURE CENTER ACROSS NORTHWESTERN
PENNSYLVANIA FRIDAY MORNING...WITH A COLD FRONT TO THE SOUTH. A
COASTAL LOW IS ALSO EXPECTED TO DEVELOP OFF THE NORTH CAROLINA
COAST THURSDAY NIGHT INTO FRIDAY MORNING. THE PA LOW WILL THEN
DISSIPATE WITH THE COASTAL LOW BECOMING THE PRIMARY LOW. LOTS OF
UNCERTAINTY WITH TEMPERATURE PROFILES/PRECIPITATION TYPES AND
AMOUNT OF PRECIPITATION THAT WILL COME IN...BUT FELT CONFIDENT
ENOUGH TO BUMP UP POPS TO LIKELY. FREEZING RAIN COULD BE A
POSSIBILITY ACROSS MUCH OF THE FORECAST AREA...AND HAVE ADDED
SLIGHT CHANCE OF FZRA TO MOST LOCATIONS DURING THE COLDEST HOURS
OF THE PERIOD. OVERALL...TEMPERATURES SHOULD BE NEAR NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
EXCEPT FOR SOME LEFT OVER SNOW FRIDAY EVENING AS THE COASTAL LOW
DEPARTS...IT APPEARS THAT BOTH SATURDAY AND SUNDAY SHOULD REMAIN DRY
WITH HIGH PRESSURE DOMINATING THE EAST COAST WEATHER. A LARGE LOW
PRESSURE CENTER WILL DEVELOP IN THE CENTRAL PLAINS AND MOVE INTO
MICHIGAN BY MONDAY MORNING...WITH THE FRONTS IMPACTING ALMOST THE
ENTIRE EASTERN UNITED STATES. HAVE GONE AHEAD AND BUMPED UP POPS TO
LIKELY WITH FAIRLY GOOD AGREEMENT BETWEEN 12Z GFS/ECMWF ALONG WITH
NAEFS ENSEMBLE. MOST OF PRECIPITATION SHOULD FALL AS RAIN...ALTHOUGH
SOME SNOW WILL LIKELY MIX IN. SOME LAKE EFFECT SNOW WILL BE POSSIBLE
MONDAY NIGHT BEHIND THE SYSTEM. HAVE ONLY INCLUDED A SLIGHT CHANCE
FOR POPS WITH A SYSTEM MOVING UP THE EAST COAST ON TUESDAY.
TEMPERATURES SHOULD BE NEAR NORMAL VALUES ON SATURDAY...RISE ABOVE
NORMAL ON SUNDAY AND MONDAY...THEN DROP BACK TO NORMAL ON TUESDAY.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
AREA OF LIGHT SNOW WITH THE WEAK UPPER LEVEL SHORT IS PUSHING
RAPIDLY EAST AND WILL BE EAST OF THE MOUNTAIN RIDGES BY 07Z.
LOWERING OVERCAST STRATOCU CAN BE EXPECTED THIS MORNING IN THE
NORTHWEST FLOW AND BRIEF COLD ADVECTION WITH MVFR CEILINGS
PREVAILING. SOME SNOW FLURRIES ARE POSSIBLE THIS MORNING...MAINLY
AT THE NORTHERN PORTS. BY THIS AFTERNOON WITH WARM ADVECTION AND
RIDGING MOVING INTO THE AREA...STRATOCU WILL SCATTER OUT WITH VFR
CONDITIONS AT ALL PORTS BY LATE AFTERNOON.
.OUTLOOK.../WEDNESDAY NIGHT THROUGH SUNDAY/...
GENERAL VFR CONDITIONS WITH HIGH PRESSURE FOR WEDNESDAY AND
THURSDAY. A STORM THURSDAY NIGHT INTO FRIDAY WILL BRING RESTRICTIONS
IN SNOW WITH RAIN POSSIBLE IN THE SOUTH. HIGH PRESSURE WILL BRING A
RETURN TO VFR FOR THE WEEKEND.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
AVIATION...RSD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1149 PM EST TUE FEB 5 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 400 PM EST TUE FEB 5 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH OVER
HUDSON BAY AND A RIDGE FROM THE ROCKIES TO BC RESULTING IN WNW FLOW
THROUGH THE NRN GREAT LAKES. A SHORTWAVE TROUGH WAS MOVING EASTWARD
THROUGH NRN IL WHILE A WEAKE SHRTWV TO THE NORTH THAT BROUGH THE
LIGHT SNOW TO UPPER MI HAD MOVED INTO NRN LOWER MI. AT THE
SFC...NRLY WINDS WERE INCREASING THROUGH UPPER MI AS A TROUGH MOVES
S THROUGH THE AREA AND A LOW MOVES EAST FROM NEAR THE SAULT. A BAND
OF SNOW SHOWERS SUPPORTED BY LOW LEVEL CONV NEAR THE TROUGH HAS
SAGGED THROUGH THE NORTH PORTION OF THE CWA.
EXPECT MAINLY LIGHT TO MODERATE NW FLOW WIND PARALLEL LES BANDS
TONIGHT. 850 MB TEMPS AROUND -20C WITH MUCH OF THE CLOUD LAYER IN
THE DGZ WILL SUPPORT HIGHER SNOW/WATER RATIOS AOA 25/1.
HOWEVER...VERY DRY AIR UPSTREAM AND INVERSION HEIGHTS AOB 4K FT WILL
ALSO LIMIT LES INTENSITY. SO...SNOWFALL AMOUNTS IN THE 1 TO 3 INCH
RANGE ARE EXPECTED...GREATEST OVER THE EAST. HIGHER RES MODELS
SUGGEST THAT DIMINISHING WINDS LATE TONIGHT MAY ALLOW DEVELOPMENT OF
A MESO-LOW OVER SE LAKE SUPERIOR. THERE IS LOW CONFIDENCE WHER OR IF
THIS WOULD MOVE ASHORE AS WINDS SLOWLY BACK IN RESPONSE TO THE
DEPARTING RIDGE TO THE SOUTH.
THE FCST KEEPS TEMPS TOWARD THE LOWER END OF GUIDANCE INLAND WEST AS
THERE MAY BE ENOUGH OF A PERIOD OF CLEAR TO PARTLY CLOUDY AS MID
CLOUDS PASS FARTHER TO THE NORTH...TO ALLOW TEMPS TO DROP OFF WELL
BELOW ZERO.
UPPER LEVEL DIV ASSOCIATED WITH A DEVELOPING 250-300 MB JET STREAK
FROM THE NRN LAKES TO NEW ENGLAND AND ASSOCIATED MID LEVEL FGEN TO
THE SOUTH INTO NW WI BY LATE TUE AFTERNOON WILLS SUPPORT AN AREA OF
LIGHT SNOW EXPANDING TOWARD UPPER MI. HOWEVER...ONLY CHANCE POPS ARE
EXPECTED INTO THE WEST BY 00Z/THU.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 400 PM EST TUE FEB 5 2013
FIRST FEATURE OF NOTE FOR THIS PERIOD WILL BE THE BROAD WAA AT
THE START OF THE PERIOD AHEAD OF AN INVERTED TROUGH SLIDING
SOUTHEAST THROUGH THE NORTHERN/CENTRAL PLAINS. INITIAL SNOW WILL BE
ONGOING AT THE START OF THE PERIOD OVER WESTERN UPPER
MICHIGAN...WHICH WILL BE LARGELY FOCUSED ALONG THE BROAD H850-600
WAA/ISENTROPIC ASCENT AND RIGHT REAR OF THE UPPER JET MOVING EAST
ACROSS THE CWA. THE BEST/SHARPEST LOW LEVEL WAA GRADIENT DOES LOOK
TO BE FARTHER SOUTH WITH THE 12Z RUNS...MORE IN WISCONSIN...SO
THINKING THAT A FARTHER SOUTH TREND TO THE QPF/SNOW IS WARRANTED.
THAT BEING SAID...THERE ARE SOME HINTS OF THE MID LEVEL FGEN TRYING
TO FOCUS/STALL NEAR SOUTHERN LAKE SUPERIOR...WHICH COULD TRY TO
INCREASE SNOWFALL AMOUNTS SOME.
WITH THE INITIAL WAA SNOW SLIDING EAST ON THURSDAY...A SHORTWAVE IS
EXPECTED TO DROP SOUTHEAST FROM THE NORTHERN PLAINS ON WEDNESDAY
NIGHT INTO THURSDAY. SHORTWAVE LOOKS TO BE A LITTLE STRONGER AND
FARTHER SOUTH THAN YESTERDAY...WHICH HAS SOME INFLUENCE ON THE
OVERALL FORECAST. GFS/ECMWF/GEM SEEM TO BE IN GOOD AGREEMENT WITH
THE TRACK/INTENSITY OF THE SHORTWAVE...WHILE THE NAM IS A LITTLE
FLATTER AND FARTHER NORTH. WILL TREND AWAY FROM THE NAM AND TOWARDS
THE OVERALL CONSENSUS. AS THE SHORTWAVE DIGS THROUGH SOUTHERN WI AND
NORTHERN ILLINOIS...THE LOW BEGINS TO WRAP UP NEAR THE LOWER GREAT
LAKES AND FOCUSES THE BETTER FORCING AND PRECIPITATION FARTHER TO
THE SOUTH ON THURSDAY. BUT...THERE SHOULD STILL BE ENOUGH LINGERING
MOISTURE AND BROAD FORCING TO LEAVE SCATTERED SNOW SHOWERS BEHIND
THE SYSTEM. IN ADDITION...SHOULD SEE SOME LAKE ENHANCEMENT OFF LAKE
SUPERIOR AS H850 TEMPS ARE AROUND -12C AND WINDS ARE OUT OF THE
NORTHEAST DIRECTION. THIS SHOULD CONTINUE INTO THURSDAY EVENING
BEFORE DIMINISHING OVERNIGHT AS THE DEEPER MOISTURE DEPARTS. OFF OF
LAKE MICHIGAN...WINDS LOOK TO BE A LITTLE MORE EASTERLY WEDNESDAY
NIGHT INTO THURSDAY MORNING...WHICH WILL ALSO ASSIST IN SOME
ENHANCEMENT FROM MENOMINEE THROUGH MANISTIQUE. WITH THE RECENT
SHIFTS IN THE FORECAST...THE WIND FIELD HAS BEEN FLUCTUATING GREATLY
WHICH PRODUCES LIMITED CONFIDENCE ON LAKE ENHANCEMENT LOCATIONS.
WITH THE FARTHER SOUTH SHIFT...THINKING MOST LOCATIONS WILL SEE
1-4 INCHES FROM WEDNESDAY AFTERNOON THROUGH THE DAY THURSDAY.
DUE TO IT/S CLOSER PROXIMITY TO BEST LOWER LEVEL WAA AND LAKE
ENHANCEMENT...COULD SEE MENOMINEE COUNTY APPROACHING THE 3 INCHES IN
24HRS ADVISORY CRITERIA WEDNESDAY NIGHT INTO THURSDAY MORNING. WILL
CONTINUE TO MENTION IN THE HWO...BUT WILL FOCUS THE WORDING MORE
TOWARDS THE SOUTH CENTRAL AND AREAS NEAR LAKE MICHIGAN.
ONE FINAL THING TO NOTE FOR THURSDAY IS THE POTENTIAL FOR MID LEVEL
DRY AIR TO ATTEMPT TO CUT OUT SOME OF THE ICE CRYSTALS IN THE
CLOUDS. IF THIS OCCURS...IT COULD LEAD TO BRIEF PERIODS OF FREEZING
DRIZZLE...BUT CONFIDENCE IS EXTREMELY LOW FOR OCCURRING AT THIS
POINT.
HIGH PRESSURE RIDGE THEN MOVES OVER THE AREA FOR LATE THURSDAY
NIGHT INTO FRIDAY NIGHT AND LEADS TO QUIET WEATHER OVER THE CWA.
NEXT WAVE BRUSHES THE NORTHERN HALF OF THE CWA ON SATURDAY AND WILL
CONTINUE TO MENTION SLIGHT OR LOW CHANCE POPS AS THAT PASSES
THROUGH.
UNCERTAINLY IN THE FORECAST GREATLY INCREASES AFTER SATURDAY...AS
MODELS HAVE BEEN DIFFERING ON THE HANDLING OF THE ENERGY EXITING THE
SOUTHWEST CONUS AND MOVING THROUGH THE GREAT LAKES. 00Z ECMWF AND
12Z GFS HAVE COME INTO BETTER AGREEMENT WITH THIS FEATURE
AND PULL A 990S MB LOW THROUGH THE UPPER GREAT LAKES REGION ON
MONDAY INTO MONDAY NIGHT. ENSEMBLE MEMBERS OF BOTH OF THOSE RUNS
VARY GREATLY...WHICH MATCHES UP WELL WITH THE VARIABILITY OVER THE
LAST DAY. WITH 12Z GEM/UKMET ALSO TRENDING TOWARDS A LOW
MOVING THROUGH THE AREA...WILL TREND POPS UP DURING THAT TIME
FRAME TO ADDRESS THE INCREASED POTENTIAL FOR SNOW. IF THE CURRENT
GFS/ECMWF FORECAST IS CORRECT...SOME LOCATIONS IN UPPER MICHIGAN
COULD SEE A HEAVY SNOWFALL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1148 PM EST TUE FEB 5 2013
VFR CONDITIONS SHOULD CONTINUE INTO THE AFTN HRS AT KIWD/KSAW DUE TO
COMBINATION OF DRY AIR MASS AND UNFAVORABLE WIND DIRECTION FOR LAKE
EFFECT CLOUDS/-SHSN. AT KCMX...DRY AIR MASS HAS EFFECTIVELY PUT AN
END TO LAKE EFFECT -SHSN...AND EVEN STRATOCU HAS CLEARED OUT.
GIVEN DEGREE OF OVERWATER INSTABILITY AND NOCTURNAL COOLING
ENHANCING CONVERGENCE OVER THE LAKE...MVFR CIGS AND PERHAPS SOME
FLURRIES MAY YET RETURN OVERNIGHT. OTHERWISE...VFR WILL GENERALLY
PREVAIL INTO THE AFTN. NEXT DISTURBANCE TRACKING TOWARD THE WRN
LAKES MAY SPREAD OF SHIELD OF -SN AND IFR CONDITIONS TO ALL 3
TERMINALS FROM NW TO SE FROM MID AFTN INTO THE EVENING HRS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 400 PM EST TUE FEB 5 2013
NORTH WINDS TO 30 KNOTS LATE THIS AFTERNOON AND EVENING AND AREAS OF
FREEZING SPRAY WILL GRADUALLY DIMINISH OVERNIGHT AS A RIDGE BUILDS
INTO THE AREA. ENE WINDS INTO THE 15 TO 25 KNOT RANGE ARE ALSO
EXPECTED LATE WED NIGHT INTO THU AS A LOW PRESSURE SYSTEM MOVES
THROUGH SOUTHERN WI. OTHERWISE...WINDS ARE EXPECTED TO REMAIN BELOW
25 KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION
NWS TULSA OK
306 AM CST WED FEB 6 2013
.DISCUSSION...
FAIRLY ACTIVE FORECAST THIS MORNING...BEGINNING WITH ONGOING DENSE
FOG ONCE AGAIN. WIDESPREAD VISIBILITIES OF A QUARTER MILE OR LESS
CURRENTLY AFFECTING MUCH OF SOUTHEAST OKLAHOMA AND PARTS OF
SEBASTIAN COUNTY IN WEST CENTRAL ARKANSAS. EASTERN EDGE OF THE FOG
IS MORE PATCHY THAN AREAS TO THE WEST...AND VISIBILITIES IN THIS
AREA HAVE NOT BEEN AS CONSISTENTLY LOW. AS A RESULT...PARTS OF
EAST CENTRAL OKLAHOMA...AS WELL AS SEBASTIAN COUNTY...MAY NEED TO
BE REMOVED FROM THE ADVISORY A BIT LATER. SATELLITE INDICATING
THE FOG/LOW CLOUDS SPREADING MORE RAPIDLY NORTHWARD ACROSS AREAS
WEST OF THE HIGHWAY 75 CORRIDOR...WITH NEAR ZERO VISIBILITIES
COMMON. HAVE ADDED CREEK AND PAWNEE COUNTIES TO THE ADVISORY AS A
RESULT. RUC RELATIVE HUMIDITY PROGS AND EXTRAPOLATION OF THE
CURRENT SATELLITE IMAGERY WOULD SUGGEST THAT TULSA AND OSAGE
COUNTIES MAY NEED TO BE ADDED LATER THIS MORNING...BUT THESE WERE
LESS OF A CERTAIN SO HELD OFF FOR NOW. WILL MONITOR. THE FOG WILL
BE SLOW TO ERODE ACROSS THE MOST AFFECTED AREAS /GENERALLY WEST OF
A HUGO TO EUFAULA TO PAWNEE LINE/...SO HAVE LINGERED A PATCHY FOG
MENTION THROUGH NOON IN THESE AREAS. THIS WILL ALSO AFFECT HIGH
TEMPERATURES...HOLDING READINGS DOWN A FEW DEGREES FROM LOCATIONS
FURTHER EAST.
WATER VAPOR SATELLITE SHOWS DEEPER MOISTURE SPREADING NORTHWARD
TOWARD THE REGION IN ASSOCIATION WITH A SHORTWAVE MOVING THROUGH
CENTRAL AND EASTERN TEXAS. SCATTERED SHOWERS/ISOLATED STORMS WILL
LIKELY GRAZE THE SOUTHEASTERN FRINGES OF THE FORECAST AREA
POSSIBLY AS EARLY AS LATE MORNING...BUT MORE LIKELY THIS AFTERNOON
AND EVENING.
GREATER AND MORE WIDESPREAD RAINFALL WILL DEVELOP AND MOVE INTO
PARTS OF NORTHEAST OKLAHOMA LATE TONIGHT IN ADVANCE OF A WEAK COLD
FRONT...SPREADING ACROSS THE REST OF THE FORECAST AREA DURING THE
DAY TOMORROW. INSTABILITY SHOULD BE ENOUGH TO SUPPORT AT LEAST A
CHANCE OF THUNDER...BUT SEVERE WEATHER IS NOT LIKELY. BENEFICIAL
RAINS...WITH SOME AREAS POSSIBLY SEEING AS MUCH AS AN INCH...WILL
BE THE MAIN OUTCOME OF THIS EVENT. TEMPERATURES IN THE WAKE OF THE
COLD FRONT WILL REMAIN ABOVE NORMAL.
DRY CONDITIONS WILL PREVAIL FRIDAY THROUGH SATURDAY MORNING...WITH
RAIN AND THUNDERSTORM CHANCES INCREASING AGAIN SATURDAY AFTERNOON
AND ESPECIALLY SATURDAY NIGHT AND SUNDAY. THE GFS HAS FINALLY
CAUGHT ON TO THE CONSISTENT ECMWF SOLUTION FEATURING A DRYLINE
PASSAGE DURING THE DAY SUNDAY...AS AN UPPER LOW MOVES THROUGH THE
CENTRAL PLAINS. THEIR 00Z SOLUTIONS ARE REMARKABLY SIMILAR.
THUNDERSTORMS ARE LIKELY TO DEVELOP SATURDAY NIGHT IN ADVANCE OF
THE DRYLINE DUE TO A STRONG LOW LEVEL JET...WITH THUNDERSTORMS
LIKELY ENDING ACROSS MOST OF THE AREA BY MIDDAY SUNDAY. SEVERE
WEATHER WILL STILL BE POSSIBLE...BUT THE EARLY DRYLINE PASSAGE
WILL LIKELY BE A LIMITING FACTOR. THE RAINS SHOULD ALSO LIMIT ANY
FIRE WEATHER POTENTIAL BEHIND THE DRYLINE SUNDAY
AFTERNOON...ALTHOUGH THAT THREAT WILL DEFINITELY NOT BE NON
EXISTENT.
MUCH COOLER WEATHER WILL BE ON THE WAY FOR THE BEGINNING OF NEXT
WEEK...ON THE HEELS OF THIS SYSTEM. A FAST MOVING UPPER TROUGH
WILL PASS THROUGH THE AREA TUESDAY NIGHT /THE ECMWFS FASTER
SOLUTION IS AN OUTLIER THIS MORNING/. TEMPERATURE PROFILES SUGGEST
LIGHT SNOW POTENTIAL WITH ANY PRECIPITATION THAN FALLS...IF THE
TUESDAY NIGHT TIMING ENDS UP VERIFYING.
A RELATIVELY QUICK WARMUP LOOKS LIKELY FOR THE LATTER PART OF
NEXT WEEK...AS SOUTH WINDS MAKE A QUICK RETURN TO THE AREA
FOLLOWING THE AFOREMENTIONED TROUGHS PASSAGE.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...DENSE FOG ADVISORY UNTIL 9 AM WEDNESDAY FOR OKZ049-OKZ053-OKZ059-
OKZ064-OKZ065-OKZ066-OKZ070-OKZ071-OKZ072-OKZ073-OKZ074-
OKZ075-OKZ076.
AR...DENSE FOG ADVISORY UNTIL 9 AM WEDNESDAY FOR ARZ029.
&&
$$
SHORT TERM...05
LONG TERM....22
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1055 AM EST WED FEB 6 2013
.UPDATE (REST OF TODAY AND TONIGHT)...
15Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUE TO SHOW AN UNAMPLIFIED
PATTERN OVER THE CONUS. MAIN FEATURE OF NOTE INCLUDE PACIFIC ENERGY
BEGINNING TO ARRIVE OVER THE COASTS OF BRITISH
COLUMBIA/WASHINGTON...A DECENT IMPULSE PROGRESSING ACROSS THE
SOUTHERN PLAINS...AND A BROAD LONGWAVE TROUGH IN PLACE OVER EASTERN
CANADA AND THE NORTHEASTERN STATES. OUR REGION CONTINUES TO RESIDE
WITHIN A MAINLY ZONAL FLOW PATTERN. A VERY WEAK SHORTWAVE EMBEDDED
IN THIS FLOW IS PASSING TROUGH THE REGION THIS MORNING AND WILL BE
TO OUR EAST BY THIS EVENING. LOCAL AREA WILL ACTUALLY GET INTO A
BRIEF RIDGING PATTERN ALOFT FOR LATER TODAY AND TONIGHT IN RESPONSE
TO THE UPSTREAM HEIGHT FALLS ASSOCIATED WITH THE SOUTHERN PLAINS
SYSTEM.
AT THE SURFACE...WEAK HIGH PRESSURE EXTENDS DOWN THE ATLANTIC
SEABOARD TO THE FLORIDA PENINSULA. A WEAK INVERTED TROUGH FEATURE
CAN ALSO BE ANALYZED OVER THE EASTERN GULF AND IS LIKELY A
REFLECTION OF THE PASSING ENERGY ALOFT. THE LOW LEVEL FOCUS ALONG
THIS SURFACE TROUGH HAS BEEN ENOUGH TO SUPPORT A REGION OF SHOWER
DEVELOPMENT FROM NEAR THE CITRUS/HERNANDO COUNTY COASTS SOUTHWEST TO
THE COASTAL WATERS OFF PINELLAS COUNTY. THIS TROUGH HAS BEEN A BIT
MORE ORGANIZED THAN WAS PREVIOUSLY ANTICIPATED AND RESULTING SHOWER
ACTIVITY AS BEEN A BIT MORE ROBUST. DUE TO THE CLOSE PROXIMITY OF
THESE SHOWERS TO THE COAST...HAVE EXPANDED THE CHANCE POP FOR A FEW
LATE MORNING/EARLY AFTERNOON SHOWERS DOWN INTO PASCO AND PINELLAS
COUNTIES. OVERALL TROUGH MOTION HAS BEEN VERY SLOW...AND THEREFORE
STILL SOME UNCERTAINLY IF ANY OF THESE SHOWERS WILL ACTUALLY REACH
THE COAST AS FAR SOUTH AS PINELLAS. EVENTUALLY LATE TODAY...AS THE
UPPER ENERGY PUSHES PAST...THIS TROUGH AND RESULTING FOCUS IS LIKELY
TO WEAKEN. AT THAT TIME...WE SHOULD BE ABLE TO REMOVE THESE SHOWER
CHANCES FROM THE FORECAST.
IN TERMS OF SKY CONDITIONS...LOOKING AT MOSTLY CLOUDY SKIES OUT
THERE LATE THIS MORNING...WITH THE EXCEPTION OF FAR SOUTHERN ZONES
DOWN TOWARD FT. MYERS. WITH TIME...EXPECT TO SEE SKIES TRANSITION TO
PARTLY CLOUDY AND ALLOW FOR MORE INSOLATION AND TEMPERATURE RISE.
TONIGHT...SHORTWAVE ENERGY TO OUR WEST WILL QUICKLY TRANSLATE ALONG
THE NORTHERN GULF COAST...WITH AN ASSOCIATED ORGANIZING AREA OF
SURFACE LOW PRESSURE MOVING TO NEAR THE MS DELTA BY SUNRISE. BEST
MOISTURE...AND SYNOPTIC LIFT ASSOCIATED WITH THIS SYSTEM WILL REMAIN
TO OUR WEST AND NORTHWEST INTO THURSDAY MORNING AND WILL KEEP THE
FORECAST DRY REGION-WIDE. A SLOW INCREASE IN LOW LEVEL ATLANTIC
MOISTURE AND MORE BOUNDARY LAYER MOMENTUM WILL HELP KEEP
TEMPERATURES UP TONIGHT. MANY LOCATIONS SOUTH OF I-4 WILL HOLD IN
THE UPPER 50S TO LOW 60S...AND IN THE 50S FURTHER NORTH ACROSS THE
NATURE COAST.
&&
.AVIATION...
PRIMARILY VFR ALTHOUGH CANT RULE OUT BRIEF MVFR CEILING WITH LIGHT
SHOWERS AROUND SRQ...TPA AND PIE. OVERALL RISK TOO LOW TO MENTION IN
TAF AS MOST SHOWERS STAY NORTH.
&&
.MARINE...
ATLANTIC HIGH PRESSURE RIDGING ACROSS THE WATERS SLOWLY WEAKENS AS
LOW PRESSURE FORMS ON THE NORTHERN GULF COAST AND TRACKS TO THE
NORTHEAST. A COLD FRONT MOVES INTO THE EASTERN GULF ON FRIDAY AND
EXITS EAST OF THE REGION FRIDAY NIGHT. HIGH PRESSURE THEN BUILDS IN
ONCE AGAIN DURING THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 78 63 77 65 / 20 10 10 20
FMY 82 62 82 64 / 10 10 10 10
GIF 80 59 81 63 / 10 10 10 20
SRQ 77 59 78 63 / 10 10 10 10
BKV 79 56 80 61 / 40 10 20 30
SPG 77 64 77 66 / 20 10 10 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...BEACH HAZARDS STATEMENT THROUGH THURSDAY EVENING FOR
CHARLOTTE-LEE-SARASOTA.
GULF WATERS...NONE.
&&
$$
UPDATE/MARINE...MROCZKA
AVIATION...JILLSON
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
913 AM CST WED FEB 6 2013
...UPDATE TO SYNOPSIS...
.SYNOPSIS...
ISSUED AT 911 AM CST WED FEB 6 2013
THE 06.12Z 250 RAOB SYNOPTIC MAP SHOWED ANTICYCLONIC JET FLOW ACROSS
THE CENTRAL US AND EXTENDING INTO PORTIONS OF THE UPPER MIDWEST. A JET
STREAK OF AROUND 125 KT WAS OBSERVED ACROSS WISCONSIN. FAIRLY LIGHT
UPPER LEVEL FLOW WAS OBSERVED ACROSS SOUTHERN KANSAS WITH ONLY 30 KT
AT KDDC. AT 500 HPA, A LARGE CYCLONE WAS LOCATED ACROSS THE NORTHEAST
PACIFIC. A FEW SHORTWAVES WERE NOTED ACROSS THE GREAT BASIN AND TEXAS.
AT 700 HPA, TEMPERATURES WERE AT ZERO CENTIGRADE ACROSS THE TEXAS PANHANDLE
AND SOUTHWEST KANSAS...INDICATING A WAA PATTERN STILL IN PLACE. THE
WARM PLUME AT 850 HPA WAS VERY EVIDENT ACROSS THE CENTRAL PLAINS WITH
VALUES IN THE 8 TO 12 DEG C RANGE. AT THE SFC, A WARM FRONT WAS LOCATED
ALONG WITH THE KANSAS/OKLAHOMA STATE LINE WITH HIGHER DEWPOINTS ADVECTING
IN FROM OKLAHOMA.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 357 AM CST WED FEB 6 2013
AN UPPER LEVEL SHORTWAVE RIDGE WILL MOVE EAST TODAY FROM THE PLAINS
INTO THE MID MISSISSIPPI VALLEY WHILE AN UPPER LEVEL SHORTWAVE
TROUGH MOVES INTO THE INTERMOUNTAIN WEST. THE SHORTWAVE TROUGH WILL
THEN MOVE ACROSS THE CENTRAL PLAINS AFTER MIDNIGHT TONIGHT WITH A
COLD FRONT. AHEAD OF THE COLD FRONT TODAY, A WARM AIRMASS WILL
CONTINUE TO PUSH INTO WESTERN KANSAS WITH 850MB TEMPS RISING TO
AROUND 12 CELSIUS. ALSO LOW LEVEL MOISTURE WILL INCREASE ACROSS MUCH
OF SOUTH CENTRAL KANSAS UNDER SOUTH WINDS AS A TROUGH OF LOW
PRESSURE DEEPENS ACROSS COLORADO INTO NEW MEXICO. SOME LOW STRATUS
AND FOG IS FORECAST BY THE RAP AND HRRR MESOSCALE MODELS EARLY THIS
MORNING FROM LIBERAL TO DODGE CITY AND PRATT BY 9 AM, THEM MOVING
NORTH TO AROUND HAYS BY 11 AM. AS LOW LEVEL MIXING INCREASES IN THE
BOUNDARY LAYER THIS MORNING, THE AREAS OF FOG AND STRATUS SHOULD
BEGIN TO BREAK IN THE MID MORNING TO AROUND NOON. OVER THE WEST
MOSTLY CLEAR SKIES WILL CONTINUE. WINDS WILL BECOME GUSTY BY
AFTERNOON WITH 2O TO 30 MPH EXPECTED. DAYTIME HIGHS SHOULD BE VERY
MILD IN THE WARM SECTOR THIS AFTERNOON WITH HIGHS IN THE MID TO
UPPER 60S TO NEAR 70 FROM WAKEENEY TO DODGE CITY AND MEADE WEST TO
THE COLORADO BORDER, AND SLIGHTLY COOLER EAST IN THE LOW TO MID 60S
WITH A BIT MORE CLOUD COVER EXPECTED.
LOOKING AT CURRENT HRRR MODEL WILL GO AHEAD WITH A DENSE FOR ADVISORY
TILL 11 AM THIS MORNING FROM LIBERAL NORTH TO GARDEN CITY AND EAST
TO LARNED AND ST. JOHN AND SOUTH TO THE OK BORDER. LOW STRATUS AND
FOG RAPIDLY APPROACHING KANSAS BORDER. WITH SOUTH WINDS DO NOT
EXPECT THE FOG TO BE DENSE FOR LONG IN ANY ONE AREA. THE FRONT EDGE
MAY HAVE THE LOWEST VISIBILITIES FOR AN HOUR OR TWO.
LATER TONIGHT, A COLD FRONT WILL SWEEP ACROSS WESTERN KANSAS WITH
SOUTH WINDS SHIFTING NORTH AND INCREASING TO 20 TO 30 MPH MAINLY
AFTER MIDNIGHT. A FEW THUNDERSTORMS MAY ALSO DEVELOP ALONG AND AHEAD
OF THE COLD FRONT FROM NEAR HAYS TO DODGE CITY AND ASHLAND AND EAST
THIS EVENING AND END BY 6 AM THURSDAY MORNING IN THE MEDICINE LODGE
AREA. THIS AREA IN MOST UNSTABLE CAPE OF 300 TO 800 J/KG FORECAST.
WILL CONTINUE TO CARRY THE HIGHEST CHANCES FOR SHOWERS AND
THUNDERSTORMS IN THE SOUTH CENTRAL SECTIONS.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 352 AM CST WED FEB 6 2013
THE SHORTWAVE TROUGH MENTIONED IN THE SHORT TERM DISCUSSION WILL
PROGRESS INTO EASTERN KANSAS BY THURSDAY AFTERNOON AND HELP TO
PUSH A COLD FRONT THROUGH SOUTHWEST KANSAS IN THE MORNING. THUS,
HIGH TEMPERATURES SHOULD BE A LITTLE COOLER IN THE 50S. THE LOW
LEVEL MOISTURE THAT WILL HAVE ADVECTED INTO SOUTHERN KANSAS
WEDNESDAY NIGHT WILL BE SHUNTED BACK TO THE GULF COAST BY THURSDAY
AFTERNOON. MEANWHILE, A DEEP UPPER LEVEL TROUGH WILL BE PROGRESSING
SOUTHEASTWARD AND AMPLIFYING ALONG THE WEST COAST. BY FRIDAY, THIS
UPPER LEVEL TROUGH WILL BE LOCATED OVER THE SOUTHERN SECTIONS OF
CALIFORNIA AND NEVADA. A SURFACE TROUGH WILL DEVELOP IN THE LEE OF
THE ROCKIES BY FRIDAY IN RESPONSE TO THE SOUTHWESTERLY MID-LEVEL FLOW
ACROSS THE ROCKIES AHEAD OF THE SYSTEM. BUT THE LOW LEVEL MOISTURE
WILL STILL BE TRAPPED IN SOUTH TEXAS AT THIS TIME. HIGH TEMPERATURES
OUGHT TO REACH THE 50S AGAIN ON FRIDAY.
BY FRIDAY NIGHT AS THE WESTERN TROUGH EDGES INTO UTAH AND ARIZONA, THE
LOW LEVEL FLOW WILL INCREASE FROM THE GULF OF MEXICO INTO THE
SOUTHERN PLAINS. BUT EVEN BY 12Z SATURDAY, THE LOW STRATUS AND GULF
MOISTURE WILL STILL BE WELL TO THE SOUTH. THIS WILL ALLOW FOR RADIATIONAL
COOLING, WITH LOWS IN THE 30S SATURDAY MORNING. ON SATURDAY, THE
UPPER TROUGH WILL PROGRESS EASTWARD, WITH MID LEVEL COOLING
APPROACHING FAR WESTERN KANSAS BY EVENING. STRATUS SHOULD DEVELOP
DURING THE DAY OVER SOUTHWEST KANSAS AS THE LOW LEVEL MOISTURE MOVES
NORTHWARD INTO A FAIRLY COOL AIRMASS. A FEW SHOWERS MAY DEVELOP IN
THE AFTERNOON AS WARM ADVECTION INCREASES IN THE WARM SECTOR. BY
LATE AFTERNOON, SOME CLEARING MAY OCCUR IN FAR WESTERN KANSAS. THIS
MAY ALLOW FOR SOME DAYTIME HEATING AND ENOUGH SURFACE BASED CAPE FOR
THUNDERSTORM DEVELOPMENT ALONG THE DRYLINE. AS ONE WOULD EXPECT THIS TIME
OF YEAR, INSTABILITY WILL BE A MAJOR LIMITING FACTOR DESPITE STRONG
SHEAR. BUT SOME SMALL HAIL CANNOT BE RULED OUT GIVEN THE EXPECTED
COLD 500MB TEMPERATURES (-20C) AND 40-45F SURFACE DEWPOINTS ON THE
HIGHER TERRAIN. ANY STORMS THAT DEVELOP WILL PROGRESS EASTWARD
ACROSS THE REMAINDER OF SOUTHWEST KANSAS SATURDAY NIGHT IN A
WEAKENED STATE. AS THIS SHORTWAVE TROUGH PASSES TO THE NORTHEAST BY
SUNDAY MORNING, THE ASSOCIATED COLD FRONT WILL MOVE THROUGH WESTERN
KANSAS. BUT THIS WILL NOT BE A CANADIAN OR ARCTIC AIRMASS, SO HIGH
TEMPERATURES SHOULD STILL REACH INTO THE UPPER 30S TO LOWER 50S ON
SUNDAY, WITH THE WARMEST READINGS IN SOUTH CENTRAL KANSAS. ANOTHER
UPPER LEVEL TROUGH WILL PROGRESS SOUTHWARD OUT OF CANADA BY
MONDAY, BUT HAVE LIMITED MOISTURE TO WORK WITH IN THE WAKE OF THE
PREVIOUS STRONG SYSTEM. TEMPERATURES SHOULD REMAIN ON THE COOL SIDE
WITH HIGHS IN THE 40S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 547 AM CST WED FEB 6 2013
DENSE FOG IS LOCATED ALONG THE THE LEADING EDGE OF AN AREA OF
IFR/MVFR CIGS THAT IS ADVANCING NORTHWARD OUT OF OKLAHOMA. THE FOG
WAS DEVELOPING AS A RESULT OF THE LOW LEVEL MOISTURE ENCOUNTERING
AIR THAT HAS UNDERGONE RADIATIONAL COOLING. AS THE CLOUD DECK
ADVANCES OVER KDDC AND KGCK BY 14Z, A BRIEF PERIOD OF 1/2 TO 1/4 MILE
VISBYS ARE POSSIBLE AS THE STRATUS ARRIVES, FOLLOWED BY IMPROVEMENT TO
VFR VISBYS AND IFR/MVFR CIGS AFTER 15 OR 16Z. VFR CIGS AND VISBYS
WILL RETURN AFTER 19Z WITH DAYTIME HEATING. BY 03Z, MOIST SOUTH-
SOUTHEASTERLY WINDS WILL RESUME AND FOG AND STRATUS COULD RETURN TO
DDC, BUT PROBABLY NOT GCK/HYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 61 38 55 28 / 10 20 10 0
GCK 65 36 53 28 / 0 0 0 0
EHA 69 35 54 28 / 0 0 0 0
LBL 69 38 54 28 / 0 0 0 0
HYS 56 37 54 28 / 10 20 0 0
P28 57 44 57 31 / 10 70 50 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 11 AM CST THIS MORNING FOR KSZ063>066-
076>081-086>090.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...KRUSE
LONG TERM...FINCH
AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
555 AM CST WED FEB 6 2013
...UPDATED FOR AVIATION DISCUSSION...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 357 AM CST WED FEB 6 2013
AN UPPER LEVEL SHORTWAVE RIDGE WILL MOVE EAST TODAY FROM THE PLAINS
INTO THE MID MISSISSIPPI VALLEY WHILE AN UPPER LEVEL SHORTWAVE
TROUGH MOVES INTO THE INTERMOUNTAIN WEST. THE SHORTWAVE TROUGH WILL
THEN MOVE ACROSS THE CENTRAL PLAINS AFTER MIDNIGHT TONIGHT WITH A
COLD FRONT. AHEAD OF THE COLD FRONT TODAY, A WARM AIRMASS WILL
CONTINUE TO PUSH INTO WESTERN KANSAS WITH 850MB TEMPS RISING TO
AROUND 12 CELSIUS. ALSO LOW LEVEL MOISTURE WILL INCREASE ACROSS MUCH
OF SOUTH CENTRAL KANSAS UNDER SOUTH WINDS AS A TROUGH OF LOW
PRESSURE DEEPENS ACROSS COLORADO INTO NEW MEXICO. SOME LOW STRATUS
AND FOG IS FORECAST BY THE RAP AND HRRR MESOSCALE MODELS EARLY THIS
MORNING FROM LIBERAL TO DODGE CITY AND PRATT BY 9 AM, THEM MOVING
NORTH TO AROUND HAYS BY 11 AM. AS LOW LEVEL MIXING INCREASES IN THE
BOUNDARY LAYER THIS MORNING, THE AREAS OF FOG AND STRATUS SHOULD
BEGIN TO BREAK IN THE MID MORNING TO AROUND NOON. OVER THE WEST
MOSTLY CLEAR SKIES WILL CONTINUE. WINDS WILL BECOME GUSTY BY
AFTERNOON WITH 2O TO 30 MPH EXPECTED. DAYTIME HIGHS SHOULD BE VERY
MILD IN THE WARM SECTOR THIS AFTERNOON WITH HIGHS IN THE MID TO
UPPER 60S TO NEAR 70 FROM WAKEENEY TO DODGE CITY AND MEADE WEST TO
THE COLORADO BORDER, AND SLIGHTLY COOLER EAST IN THE LOW TO MID 60S
WITH A BIT MORE CLOUD COVER EXPECTED.
LOOKING AT CURRENT HRRR MODEL WILL GO AHEAD WITH A DENSE FOR ADVISORY
TILL 11 AM THIS MORNING FROM LIBERAL NORTH TO GARDEN CITY AND EAST
TO LARNED AND ST. JOHN AND SOUTH TO THE OK BORDER. LOW STRATUS AND
FOG RAPIDLY APPROACHING KANSAS BORDER. WITH SOUTH WINDS DO NOT
EXPECT THE FOG TO BE DENSE FOR LONG IN ANY ONE AREA. THE FRONT EDGE
MAY HAVE THE LOWEST VISIBILITIES FOR AN HOUR OR TWO.
LATER TONIGHT, A COLD FRONT WILL SWEEP ACROSS WESTERN KANSAS WITH
SOUTH WINDS SHIFTING NORTH AND INCREASING TO 20 TO 30 MPH MAINLY
AFTER MIDNIGHT. A FEW THUNDERSTORMS MAY ALSO DEVELOP ALONG AND AHEAD
OF THE COLD FRONT FROM NEAR HAYS TO DODGE CITY AND ASHLAND AND EAST
THIS EVENING AND END BY 6 AM THURSDAY MORNING IN THE MEDICINE LODGE
AREA. THIS AREA IN MOST UNSTABLE CAPE OF 300 TO 800 J/KG FORECAST.
WILL CONTINUE TO CARRY THE HIGHEST CHANCES FOR SHOWERS AND
THUNDERSTORMS IN THE SOUTH CENTRAL SECTIONS.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 352 AM CST WED FEB 6 2013
THE SHORTWAVE TROUGH MENTIONED IN THE SHORT TERM DISCUSSION WILL
PROGRESS INTO EASTERN KANSAS BY THURSDAY AFTERNOON AND HELP TO
PUSH A COLD FRONT THROUGH SOUTHWEST KANSAS IN THE MORNING. THUS,
HIGH TEMPERATURES SHOULD BE A LITTLE COOLER IN THE 50S. THE LOW
LEVEL MOISTURE THAT WILL HAVE ADVECTED INTO SOUTHERN KANSAS
WEDNESDAY NIGHT WILL BE SHUNTED BACK TO THE GULF COAST BY THURSDAY
AFTERNOON. MEANWHILE, A DEEP UPPER LEVEL TROUGH WILL BE PROGRESSING
SOUTHEASTWARD AND AMPLIFYING ALONG THE WEST COAST. BY FRIDAY, THIS
UPPER LEVEL TROUGH WILL BE LOCATED OVER THE SOUTHERN SECTIONS OF
CALIFORNIA AND NEVADA. A SURFACE TROUGH WILL DEVELOP IN THE LEE OF
THE ROCKIES BY FRIDAY IN RESPONSE TO THE SOUTHWESTERLY MID-LEVEL FLOW
ACROSS THE ROCKIES AHEAD OF THE SYSTEM. BUT THE LOW LEVEL MOISTURE
WILL STILL BE TRAPPED IN SOUTH TEXAS AT THIS TIME. HIGH TEMPERATURES
OUGHT TO REACH THE 50S AGAIN ON FRIDAY.
BY FRIDAY NIGHT AS THE WESTERN TROUGH EDGES INTO UTAH AND ARIZONA, THE
LOW LEVEL FLOW WILL INCREASE FROM THE GULF OF MEXICO INTO THE
SOUTHERN PLAINS. BUT EVEN BY 12Z SATURDAY, THE LOW STRATUS AND GULF
MOISTURE WILL STILL BE WELL TO THE SOUTH. THIS WILL ALLOW FOR RADIATIONAL
COOLING, WITH LOWS IN THE 30S SATURDAY MORNING. ON SATURDAY, THE
UPPER TROUGH WILL PROGRESS EASTWARD, WITH MID LEVEL COOLING
APPROACHING FAR WESTERN KANSAS BY EVENING. STRATUS SHOULD DEVELOP
DURING THE DAY OVER SOUTHWEST KANSAS AS THE LOW LEVEL MOISTURE MOVES
NORTHWARD INTO A FAIRLY COOL AIRMASS. A FEW SHOWERS MAY DEVELOP IN
THE AFTERNOON AS WARM ADVECTION INCREASES IN THE WARM SECTOR. BY
LATE AFTERNOON, SOME CLEARING MAY OCCUR IN FAR WESTERN KANSAS. THIS
MAY ALLOW FOR SOME DAYTIME HEATING AND ENOUGH SURFACE BASED CAPE FOR
THUNDERSTORM DEVELOPMENT ALONG THE DRYLINE. AS ONE WOULD EXPECT THIS TIME
OF YEAR, INSTABILITY WILL BE A MAJOR LIMITING FACTOR DESPITE STRONG
SHEAR. BUT SOME SMALL HAIL CANNOT BE RULED OUT GIVEN THE EXPECTED
COLD 500MB TEMPERATURES (-20C) AND 40-45F SURFACE DEWPOINTS ON THE
HIGHER TERRAIN. ANY STORMS THAT DEVELOP WILL PROGRESS EASTWARD
ACROSS THE REMAINDER OF SOUTHWEST KANSAS SATURDAY NIGHT IN A
WEAKENED STATE. AS THIS SHORTWAVE TROUGH PASSES TO THE NORTHEAST BY
SUNDAY MORNING, THE ASSOCIATED COLD FRONT WILL MOVE THROUGH WESTERN
KANSAS. BUT THIS WILL NOT BE A CANADIAN OR ARCTIC AIRMASS, SO HIGH
TEMPERATURES SHOULD STILL REACH INTO THE UPPER 30S TO LOWER 50S ON
SUNDAY, WITH THE WARMEST READINGS IN SOUTH CENTRAL KANSAS. ANOTHER
UPPER LEVEL TROUGH WILL PROGRESS SOUTHWARD OUT OF CANADA BY
MONDAY, BUT HAVE LIMITED MOISTURE TO WORK WITH IN THE WAKE OF THE
PREVIOUS STRONG SYSTEM. TEMPERATURES SHOULD REMAIN ON THE COOL SIDE
WITH HIGHS IN THE 40S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 547 AM CST WED FEB 6 2013
DENSE FOG IS LOCATED ALONG THE THE LEADING EDGE OF AN AREA OF
IFR/MVFR CIGS THAT IS ADVANCING NORTHWARD OUT OF OKLAHOMA. THE FOG
WAS DEVELOPING AS A RESULT OF THE LOW LEVEL MOISTURE ENCOUNTERING
AIR THAT HAS UNDERGONE RADIATIONAL COOLING. AS THE CLOUD DECK
ADVANCES OVER KDDC AND KGCK BY 14Z, A BRIEF PERIOD OF 1/2 TO 1/4 MILE
VISBYS ARE POSSIBLE AS THE STRATUS ARRIVES, FOLLOWED BY IMPROVEMENT TO
VFR VISBYS AND IFR/MVFR CIGS AFTER 15 OR 16Z. VFR CIGS AND VISBYS
WILL RETURN AFTER 19Z WITH DAYTIME HEATING. BY 03Z, MOIST SOUTH-
SOUTHEASTERLY WINDS WILL RESUME AND FOG AND STRATUS COULD RETURN TO
DDC, BUT PROBABLY NOT GCK/HYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 65 37 55 28 / 10 20 10 0
GCK 67 33 53 28 / 0 0 0 0
EHA 69 32 54 28 / 0 0 0 0
LBL 69 35 54 28 / 0 0 0 0
HYS 63 36 54 28 / 10 20 0 0
P28 64 43 57 31 / 10 70 50 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 11 AM CST THIS MORNING FOR KSZ063>066-
076>081-086>090.
&&
$$
SHORT TERM...KRUSE
LONG TERM...FINCH
AVIATION...FINCH
AREA FORECAST DISCUSSION...UPDATED
NWS DODGE CITY KS
403 AM CST WED FEB 6 2013
...UPDATED FOR SHORT TERM...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 357 AM CST WED FEB 6 2013
AN UPPER LEVEL SHORTWAVE RIDGE WILL MOVE EAST TODAY FROM THE PLAINS
INTO THE MID MISSISSIPPI VALLEY WHILE AN UPPER LEVEL SHORTWAVE
TROUGH MOVES INTO THE INTERMOUNTAIN WEST. THE SHORTWAVE TROUGH WILL
THEN MOVE ACROSS THE CENTRAL PLAINS AFTER MIDNIGHT TONIGHT WITH A
COLD FRONT. AHEAD OF THE COLD FRONT TODAY, A WARM AIRMASS WILL
CONTINUE TO PUSH INTO WESTERN KANSAS WITH 850MB TEMPS RISING TO
AROUND 12 CELSIUS. ALSO LOW LEVEL MOISTURE WILL INCREASE ACROSS MUCH
OF SOUTH CENTRAL KANSAS UNDER SOUTH WINDS AS A TROUGH OF LOW
PRESSURE DEEPENS ACROSS COLORADO INTO NEW MEXICO. SOME LOW STRATUS
AND FOG IS FORECAST BY THE RAP AND HRRR MESOSCALE MODELS EARLY THIS
MORNING FROM LIBERAL TO DODGE CITY AND PRATT BY 9 AM, THEM MOVING
NORTH TO AROUND HAYS BY 11 AM. AS LOW LEVEL MIXING INCREASES IN THE
BOUNDARY LAYER THIS MORNING, THE AREAS OF FOG AND STRATUS SHOULD
BEGIN TO BREAK IN THE MID MORNING TO AROUND NOON. OVER THE WEST
MOSTLY CLEAR SKIES WILL CONTINUE. WINDS WILL BECOME GUSTY BY
AFTERNOON WITH 2O TO 30 MPH EXPECTED. DAYTIME HIGHS SHOULD BE VERY
MILD IN THE WARM SECTOR THIS AFTERNOON WITH HIGHS IN THE MID TO
UPPER 60S TO NEAR 70 FROM WAKEENEY TO DODGE CITY AND MEADE WEST TO
THE COLORADO BORDER, AND SLIGHTLY COOLER EAST IN THE LOW TO MID 60S
WITH A BIT MORE CLOUD COVER EXPECTED.
LOOKING AT CURRENT HRRR MODEL WILL GO AHEAD WITH A DENSE FOR ADVISORY
TILL 11 AM THIS MORNING FROM LIBERAL NORTH TO GARDEN CITY AND EAST
TO LARNED AND ST. JOHN AND SOUTH TO THE OK BORDER. LOW STRATUS AND
FOG RAPIDLY APPROACHING KANSAS BORDER. WITH SOUTH WINDS DO NOT
EXPECT THE FOG TO BE DENSE FOR LONG IN ANY ONE AREA. THE FRONT EDGE
MAY HAVE THE LOWEST VISIBILITIES FOR AN HOUR OR TWO.
LATER TONIGHT, A COLD FRONT WILL SWEEP ACROSS WESTERN KANSAS WITH
SOUTH WINDS SHIFTING NORTH AND INCREASING TO 20 TO 30 MPH MAINLY
AFTER MIDNIGHT. A FEW THUNDERSTORMS MAY ALSO DEVELOP ALONG AND AHEAD
OF THE COLD FRONT FROM NEAR HAYS TO DODGE CITY AND ASHLAND AND EAST
THIS EVENING AND END BY 6 AM THURSDAY MORNING IN THE MEDICINE LODGE
AREA. THIS AREA IN MOST UNSTABLE CAPE OF 300 TO 800 J/KG FORECAST.
WILL CONTINUE TO CARRY THE HIGHEST CHANCES FOR SHOWERS AND
THUNDERSTORMS IN THE SOUTH CENTRAL SECTIONS.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 352 AM CST WED FEB 6 2013
THE SHORTWAVE TROUGH MENTIONED IN THE SHORT TERM DISCUSSION WILL
PROGRESS INTO EASTERN KANSAS BY THURSDAY AFTERNOON AND HELP TO
PUSH A COLD FRONT THROUGH SOUTHWEST KANSAS IN THE MORNING. THUS,
HIGH TEMPERATURES SHOULD BE A LITTLE COOLER IN THE 50S. THE LOW
LEVEL MOISTURE THAT WILL HAVE ADVECTED INTO SOUTHERN KANSAS
WEDNESDAY NIGHT WILL BE SHUNTED BACK TO THE GULF COAST BY THURSDAY
AFTERNOON. MEANWHILE, A DEEP UPPER LEVEL TROUGH WILL BE PROGRESSING
SOUTHEASTWARD AND AMPLIFYING ALONG THE WEST COAST. BY FRIDAY, THIS
UPPER LEVEL TROUGH WILL BE LOCATED OVER THE SOUTHERN SECTIONS OF
CALIFORNIA AND NEVADA. A SURFACE TROUGH WILL DEVELOP IN THE LEE OF
THE ROCKIES BY FRIDAY IN RESPONSE TO THE SOUTHWESTERLY MID-LEVEL FLOW
ACROSS THE ROCKIES AHEAD OF THE SYSTEM. BUT THE LOW LEVEL MOISTURE
WILL STILL BE TRAPPED IN SOUTH TEXAS AT THIS TIME. HIGH TEMPERATURES
OUGHT TO REACH THE 50S AGAIN ON FRIDAY.
BY FRIDAY NIGHT AS THE WESTERN TROUGH EDGES INTO UTAH AND ARIZONA, THE
LOW LEVEL FLOW WILL INCREASE FROM THE GULF OF MEXICO INTO THE
SOUTHERN PLAINS. BUT EVEN BY 12Z SATURDAY, THE LOW STRATUS AND GULF
MOISTURE WILL STILL BE WELL TO THE SOUTH. THIS WILL ALLOW FOR RADIATIONAL
COOLING, WITH LOWS IN THE 30S SATURDAY MORNING. ON SATURDAY, THE
UPPER TROUGH WILL PROGRESS EASTWARD, WITH MID LEVEL COOLING
APPROACHING FAR WESTERN KANSAS BY EVENING. STRATUS SHOULD DEVELOP
DURING THE DAY OVER SOUTHWEST KANSAS AS THE LOW LEVEL MOISTURE MOVES
NORTHWARD INTO A FAIRLY COOL AIRMASS. A FEW SHOWERS MAY DEVELOP IN
THE AFTERNOON AS WARM ADVECTION INCREASES IN THE WARM SECTOR. BY
LATE AFTERNOON, SOME CLEARING MAY OCCUR IN FAR WESTERN KANSAS. THIS
MAY ALLOW FOR SOME DAYTIME HEATING AND ENOUGH SURFACE BASED CAPE FOR
THUNDERSTORM DEVELOPMENT ALONG THE DRYLINE. AS ONE WOULD EXPECT THIS TIME
OF YEAR, INSTABILITY WILL BE A MAJOR LIMITING FACTOR DESPITE STRONG
SHEAR. BUT SOME SMALL HAIL CANNOT BE RULED OUT GIVEN THE EXPECTED
COLD 500MB TEMPERATURES (-20C) AND 40-45F SURFACE DEWPOINTS ON THE
HIGHER TERRAIN. ANY STORMS THAT DEVELOP WILL PROGRESS EASTWARD
ACROSS THE REMAINDER OF SOUTHWEST KANSAS SATURDAY NIGHT IN A
WEAKENED STATE. AS THIS SHORTWAVE TROUGH PASSES TO THE NORTHEAST BY
SUNDAY MORNING, THE ASSOCIATED COLD FRONT WILL MOVE THROUGH WESTERN
KANSAS. BUT THIS WILL NOT BE A CANADIAN OR ARCTIC AIRMASS, SO HIGH
TEMPERATURES SHOULD STILL REACH INTO THE UPPER 30S TO LOWER 50S ON
SUNDAY, WITH THE WARMEST READINGS IN SOUTH CENTRAL KANSAS. ANOTHER
UPPER LEVEL TROUGH WILL PROGRESS SOUTHWARD OUT OF CANADA BY
MONDAY, BUT HAVE LIMITED MOISTURE TO WORK WITH IN THE WAKE OF THE
PREVIOUS STRONG SYSTEM. TEMPERATURES SHOULD REMAIN ON THE COOL SIDE
WITH HIGHS IN THE 40S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1141 PM CST TUE FEB 5 2013
NEW RAP MODEL CONTINUES TO SHOW LOW STRATUS AND FOG WITH IFR
CONDITIONS TO RAPIDLY SPREAD NORTH EARLY THIS MORNING FROM
OKLAHOMA AND TEXAS. WILL BRING IN IFR CONDITIONS FROM 14-17Z
AT KDDC AND FROM 17-19Z AT KHYS. AT KGCK IT LOOKS LIKE THE STRATUS
MAY JUST MISS TO THE EAST. SOUTH WINDS THEN ARE FORECAST AT
15-25KT WITH THE STRATUS TRYING TO BREAK INTO THE AFTERNOON. A
COLD FRONT WILL MOVE INTO WESTERN KANSAS IN THE EVENING WITH FROPA
AROUND 02-04Z FROM KGCK TO KHYS, THEN AROUND 05-07Z AT KDDC. A FEW
THUNDERSTORM MAY ALSO DEVELOP ALONG THE FROPA MAINLY AFTER 06Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 65 37 55 28 / 10 20 10 0
GCK 67 33 53 28 / 0 0 0 0
EHA 69 32 54 28 / 0 0 0 0
LBL 69 35 54 28 / 0 0 0 0
HYS 63 36 54 28 / 10 20 0 0
P28 64 43 57 31 / 10 70 50 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 11 AM CST THIS MORNING FOR KSZ063>066-
076>081-086>090.
&&
$$
SHORT TERM...KRUSE
LONG TERM...FINCH
AVIATION...KRUSE
AREA FORECAST DISCUSSION
NWS CARIBOU ME
945 AM EST WED FEB 6 2013
.SYNOPSIS...
LOW WITH IT ASSOCIATED ARCTIC FRONT WILL CROSS JUST NORTH THE
REGION BY LATE AFTERNOON BRINGING A ROUND OF SNOW TO THE AREA.
ARCTIC HIGH PRESSURE FROM CENTRAL CANADA WILL THEN BUILD TOWARD
THE REGION OVERNIGHT AND THURSDAY...CROSSING THE REGION THURSDAY
NIGHT. STRONG LOW PRESSURE INTENSIFYING OFF THE MID ATLANTIC
STATES ON FRI WILL MOVE EAST... NORTHEAST JUST SOUTH OF THE GULF
OF MAINE AND NOVA SCOTIA FRIDAY NIGHT AND SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
915 AM UPDATE...INVERTED TROF ACROSS THE REGION THIS MORNING
AIDING IN LLVL CONVERGENCE W/SOME SNOW BREAKING OUT ACROSS THE
CWA. LATEST RADAR AND SATL IMAGERY SHOWED SOME ENHANCED ACROSS THE
DOWNEAST AND EASTERN SECTIONS. THEREFORE, W/THIS IN MIND, DECIDED
TO BRING THE POPS UP TO CATEGORICAL(80-90%) INTO THE AFTERNOON.
THE LATEST RUC SHOWED SOME FRONTOGENESIS AT 1000-700MBS ACROSS THE
DOWNEAST THIS MORNING AND ANOTHER LARGER AREA ACROSS NORTHERN
AROOSTOOK COUNTY THIS AFTERNOON W/THE ARCTIC FRONT. ADDED A
MENTION OF BRIEF HEAVY SNOW DUE THIS FORCING. ALSO USED THE
FORCING TO BOOST SNOWFALL TOTALS A TAD ESPECIALLY FOR THE EASTERN
CORRIDOR OF THE CWA W/1-3 INCHES POSSIBLE. WE COULD BE SEEING
BRIEF WHITEOUT CONDITIONS W/GUSTS TO 35 MPH AFTER 18Z.
TEMPERATURES WERE ADJUSTED USING THE LATEST OBS BLENDED IN W/THE
LATEST LAMP.
PREVIOUS DISCUSSION...
LOW PRESSURE CURRENTLY POSITIONED OVER SOUTHWESTERN QUEBEC WILL
TREK EASTWARD TODAY, REMAINING NORTH OF THE INTERNATIONAL BORDER.
MEANWHILE, SECONDARY LOW PRESSURE WILL ATTEMPT TO FORM OFF THE NEW
ENGLAND COAST, RESULTING IN TROFINESS EXTENDING SOUTHWARD FROM THE
PRIMARY LOW. SNOW ASSOCIATED WITH THESE TWO FEATURES CAN ALREADY
BE SEEN ON UPSTREAM RADAR, ESPECIALLY ACROSS SOUTHERN NEW ENGLAND
INTO THE GULF OF MAINE. THIS SNOW WILL GRADUALLY EXPAND IN
COVERAGE AS IT PUSHES EASTWARD INTO OUR FORECAST AREA. WEAK
FORCING MEANS QPF WILL BE MINIMAL, BUT A HIGH FLUFF FACTOR WILL
ALLOW FOR AN INCH OR TWO OF SNOW ACCUMULATION EVEN SO. LOCALIZED
AMOUNTS OF UP TO 3 INCHES ARE POSSIBLE IN DOWNEAST MAINE AS THE
AFOREMENTIONED SECONDARY LOW TRIES TO FORM. HIGHS WILL FEEL MILD
COMPARED TO YESTERDAY AS TEMPERATURES RISE INTO THE 20S IN MOST
SPOTS.
A COLD FRONT WILL SINK SOUTHWARD ACROSS THE STATE MID TO LATE THIS
AFTERNOON AS MUCH COLDER AIR WRAPS AROUND THE PARENT LOW. MODEL
GUIDANCE INDICATES THERE WILL BE VIGOROUS LIFT JUST AHEAD OF AND
ALONG THIS BOUNDARY, SO WOULD NOT BE SURPRISED TO SEE A NARROW BAND
OF SNOW SQUALLS DEVELOP AS IT CROSSES THE REGION. IN FACT, THIS MAY
BE WHEN MANY LOCATIONS PICK UP THE MAJORITY OF THEIR SNOW,
ESPECIALLY THOSE IN NORTHERN MAINE. WINDS WILL TURN TO THE WEST
NORTHWEST AND INTENSIFY POST FRONT, USHERING DRY ARCTIC AIR INTO
NORTHERN NEW ENGLAND. ANY LINGERING SNOW SHOWERS WILL QUICKLY COME
TO AN END THIS EVENING AS CLOUDS DISSIPATE. TEMPERATURES WILL
PLUMMET OVERNIGHT; NORTHERN AREAS TO 15 TO 25 BELOW ZERO, SOUTHERN
AREAS AWAY FROM THE COAST 0 TO 10 BELOW. THIS COUPLED WITH GUSTY
WINDS WILL RESULT IN VERY COLD WIND CHILLS TONIGHT. HAVE THEREFORE
ISSUED WIND CHILL HEADLINES FOR THE ENTIRE FORECAST AREA EXCEPT
COASTAL HANCOCK AND WASHINGTON COUNTIES, WHERE TEMPERATURES WILL
REMAIN ON THE POSITIVE SIDE OF ZERO.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
ARCTIC HI PRES WILL PROVIDE A BITTERLY COLD DAY THU...WITH HI
TEMPS NOT LIKELY REACHING ABV ZERO OVR NW AND FAR NERN PTNS OF
THE REGION. UNDER MCLR SKIES IN THE EVE...CONDITIONS START OFF
IDEAL FOR ARCTIC SFC BASE INVSN CONDITIONS AS THE ARCTIC HI PRES
RIDGE CRESTS THE FA THU EVE...BUT HI AND MID CLDNSS WILL SPREAD
WSW TO ENE OVR THE FA BY LATE THU NGT AHEAD OF THE DEVELOPING MID
ATLC/ GREAT LKS STORM SYS. THIS WILL LIKELY RESULT IN ERLY OVRNGT
LOW TEMPS...SPCLY WRN AND SRN PTNS OF THE FA...WITH LESS CERTAINTY
OF ERLY LOWS IN THE FAR N AND E WHERE CLDNSS WILL REACH LAST. WILL
NOT GO FOR LOW TEMPS MUCH BLO MOS GUIDANCE ATTM...BUT WE MAY BE
ABLE TO REFINE THIS PTN OF THE FCST OVR THE NEXT DAY OR SO.
OTHERWISE...LGT SNFL FROM THE WEAKENING LOWER GREAT LAKES LOW
WILL INITIALLY SPREAD INTO MSLY WRN AND SRN PTNS OF THE FA FRI.
MORE SIG SNFL WILL LIKELY ARRIVE FOR DOWNEAST PTNS OF THE REGION
FRI NGT AS THE SECONDARY LOW MOVING OFF THE MID ATLC COAST
INTENSIFIES AS IT MOVES ENE JUST OF THE GULF OF ME. GIVEN MODEL
SPREAD REGARDING THE INTENSITY AND TRACK OF THE SECONDARY
LOW...CANNOT SAY FOR SURE WHETHER WNTR HDLNS ARE GUARANTEED EVEN
OVR DOWNEAST AREAS LATE FRI INTO SAT MORN...BUT THEY ARE A GOOD
POSSIBILITY...AND FOR NOW WE WILL GO WITH CATEGORICAL SN POPS
WITH THE SIG QPF POTENTIAL. FURTHER N...POPS DROP OFF TO LIKELY
OVR N AND E CNTRL AND TO CHC TO FAR NRN PTNS OF THE FA DURG THIS
TM PD WITH DECREASING QPF POTENTIAL. IN FACT BASED ON THE 00Z GFS
ENS MEAN AND DTMNSTC ECMWF MODEL SOLUTIONS...IT IS POSSIBLE THAT
ACCUMULATING SNFL WITH THIS SYSTEM MAY NOT REACH THE NRN ST JOHN
VLY...BUT IT`S TO ERLY TO TRY TO FCST A SHARP CUT-OFF OF SNFL OVR
FAR NRN PTNS OF THE FA ATTM.
STEADY SNFL SHOULD WIND DOWN AND END AS SN SHWRS FIRST FROM
NW AREAS SAT MORN AND THEN SE AREAS SAT AFTN UNDER BRISK
CONDITIONS...WITH ENOUGH LLVL DRY AIR BEING DRAWN INTO THE WRN
SIDE OF THE LOW TO BRING CLRG CONDITIONS TO THE NW PTN OF THE FA
SAT AFTN.
TEMPS WILL RECOVER SOME FRI...AND LIKELY NOT FALL MUCH FRI NGT
WITH CLD CVR AND POTENTIAL SNFL...WITH THE AIR MASS BEHIND THE
LOW SAT NOT AS DEEPLY ARCTIC IN RESIDENCE AS THE AIR MASS AHEAD
OF THE LOW.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
SAT NGT AND SUN WILL BE FAIR WITH SEASONAL TEMPS AND EVEN A
WARMING TREND FOR SUN. WITH THE ARCTIC AIR IN RETREAT SUN NGT
INTO MON...THE NEXT LOW PRES SYSTEM FROM THE GREAT LKS IS FCSTD TO
TRACK MUCH FURTHER N MON...TO EITHER OVR OR JUST N OF THE FA LATE
MON NGT INTO TUE. FOR NOW...WE GO WITH CHC SN POPS OVR THE N HLF
OF THE FA MON INTO MON NGT AND CHC SN CHG TO A CHC MIX OVR THE S
HLF AND EVEN RN ALG THE DOWNEAST COAST. ANY PRECIP WITH THIS
SYSTEM SHOULD TRANSITION BACK TO SN SHWRS EVEN OVR SRN PTNS OF THE
FA LATE MON NGT INTO TUE MORN AS THE LOW MOVES ENE OF THE FA AND A
TRAILING COLD FRONT CROSSES THE REGION. FOR TMG PURPOSES...00Z GFS
AND GMOS POPS WERE BLENDED WITH 00Z ECMWF MODEL POPS.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: VFR CONDITIONS WILL DROP TO MVFR AND EVENTUALLY IFR
THIS AFTERNOON AS SNOW SPREADS ACROSS THE AREA. THE SNOW WILL
GENERALLY BE LIGHT WITH VISIBILITIES REMAINING 1-3 SM. A FRONT
WILL PASS FROM NORTH TO SOUTH LATE THIS AFTERNOON, RESULTING IN
WINDS SHIFTING FROM SOUTH TO WEST NORTHWEST. WINDS WILL BECOME
GUSTY AS WELL, WITH PEAKS AROUND 25 KT. SNOW WILL END AT ALL
LOCATIONS AFTER 00Z WITH A RETURN TO VFR.
SHORT TO LONG TERM: VFR XPCTD THU THRU THU NGT...WITH CONDITIONS
LOWERING TO IFR IN SN FOR DOWNEAST SITES FRI INTO SAT MORN...AND
MVFR FOR NRN TAF SITES WITH KHUL WITHER MVFR OR IFR DURG THIS TM.
VFR CONDITIONS SHOULD RETURN FOR ALL SITES BY SAT NGT AND CONT
THRU SUN.
&&
.MARINE...
NEAR TERM: A COLD FRONT WILL CROSS THE GULF OF MAINE LATE THIS
AFTERNOON AND EVENING. WINDS BEHIND THE FRONT WILL TURN TO THE
WEST NORTHWEST AND PICK UP TO 15-25 KT WITH GUSTS TO 30 KT. HAVE
THEREFORE CONTINUED WITH THE SMALL CRAFT ADVISORY, BUT SLID THE
START TIME UP A FEW HOURS TO 4 PM. THE ADVISORY THEN CONTINUES
THROUGH TONIGHT.
SHORT TO LONG TERM: INITIALLY...SCA CONDITIONS WILL WIND DOWN
ACROSS THE WATERS BY LATE THU AFTN. NO HDLNS NEEDED UNTIL FRI
UNTIL WINDS INCREASE TO AT LEAST GALE POTENTIAL BY FRI NGT CONTG
INTO SAT. DEPENDING ON THE EXACT TRACK AND INTENSITY OF THE OPEN
ATLC STORM...WE CANNOT RULE STORM FORCE WINDS... BUT GIVEN
UNCERTAINTY ATTM...WE WILL LIMIT MAX GUSTS TO 45 KT LATE FRI NGT
AND SAT MORN. NW WINDS WILL THEN DIMINISH SAT NGT INTO SUN WITH
AN INTERIM SCA NEEDED DURG THIS TM.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WIND CHILL WARNING FROM 11 PM THIS EVENING TO 11 AM EST
THURSDAY FOR MEZ001>004.
WIND CHILL ADVISORY FROM 1 AM TO 11 AM EST THURSDAY FOR MEZ011-
015>017-031-032.
WIND CHILL ADVISORY FROM 11 PM THIS EVENING TO 11 AM EST
THURSDAY FOR MEZ005-006-010.
MARINE...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 4 PM EST
THURSDAY FOR ANZ050>052.
&&
$$
NEAR TERM...HASTINGS/HEWITT
SHORT TERM...VJN
LONG TERM...VJN
AVIATION...HASTINGS/HEWITT
MARINE...HASTINGS/HEWITT/VJN
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
634 AM EST WED FEB 6 2013
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OVER THE AREA TODAY AND PROVIDE A BREAK FROM
SNOW THROUGH THURSDAY. A SURFACE LOW WILL BRING A FRONT WITH A
WINTRY MIX OF PRECIPITATION TO THE AREA THURSDAY NIGHT INTO EARLY
FRIDAY. HIGH PRESSURE WILL THEN RETURN DRY WEATHER FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
630 AM UPDATE TO ADD SEVERAL HOURS OF FLURRIES THIS MORNING WEST OF
THE RIDGES. FLURRIES AND PATCHY FREEZING DRIZZLE CAN BE EXPECTED
IN THE MOUNTAINS SOUTH AND EAST OF PITTSBURGH FOR SEVERAL HOURS
THIS MORNING.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES THE AXIS OF A BROAD
SHORT WAVE TROUGH MOVING INTO THE MID-ATLANTIC. AT 850MB...A
ZONAL FLOW IS VEERING TO MORE WEST-NORTHWESTERLY WITH WEAK CAA IN
THE WAKE OF THE WAVE. WITH THE LOW-LEVEL FLOW PERPENDICULAR TO THE
RIDGES AND A SATURATED 1000-750MB LAYER...UPSLOPING SNOW
ENHANCEMENT IS CONTINUING ACROSS THE RIDGES. AT THE SURFACE...A
BROAD HIGH EXTENDS FROM THE UPPER MIDWEST ACROSS THE MISSOURI
VALLEY AND INTO THE TN VALLEY. THE HIGH IS SLIDING EASTWARD TOWARD
THE UPPER OHIO VALLEY. SUBSIDENCE ASSOCIATED WITH THE HIGH AND NVA
IN THE WAKE OF THE WAVE HAVE ALLOWED FOR SNOW TO COME TO AN END
ACROSS THE LOWLANDS.
TODAY AND TONIGHT...GFS/ECMWF ARE IN AGREEMENT THAT A
WEST-NORTHWESTERLY MID-LEVEL FLOW TODAY WILL BACK TO MORE ZONAL
TONIGHT AND THE SURFACE HIGH WILL MOVE OVER THE AREA. CHANCE POPS
WITH SNOW SHOWERS ARE FORECAST TO CONTINUE EARLY IN UPSLOPING
ACROSS THE RIDGES. DESPITE A COLD WEST-NWRLY 850MB FLOW OFF OF
ERIE...LAKE EFFECT ZONES ARE FORECAST TO BE MOSTLY DRY WITH AN
INVERSION LOWERING TO AROUND 2KFT AFTER A CHANCE OF SNOW SHOWERS
THIS MORNING IN CONVERGENCE ALONG A WIND SHIFT. HIRES MODELS
SUPPORT CHC POPS LINGERING THROUGH THE MORNING ACROSS THE RIDGES
OF THE LAUREL HIGHLANDS AND ALLEGHENY FRONT UNTIL THIS AFTERNOON
WHEN MORE SUBSIDENCE MOVES OVER THE AREA.
FOR TEMPS...HIGHS TODAY LEAN CLOSER TO THE SLIGHTLY WARMER MET
GUIDANCE AS WEAK WAA ADVECTION ENSUES AFTER 18Z. HIGHS WILL RANGE
FROM THE MID 20S ALONG THE I-80 CORRIDOR THE LOWER 30S ACROSS
LOCATIONS SOUTH AND WEST OF THE PITTSBURGH METRO. FOR LOWS ON
WEDNESDAY NIGHT...SOME CLEARING AND NEAR CALM WINDS WILL ALLOW FOR
RADIATIONAL COOLING ACROSS THE AREA. A MAV/MET BLEND WAS USED WITH
LOWS RANGING FROM THE LOWER 20S IN PORTIONS OF EASTERN OHIO TO THE
LOWER TEENS IN VENANGO/CLARION/JEFFERSON COUNTIES.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
A MODEL CONSENSUS INDICATES THAT HIGH PRESSURE WILL PUSH EAST OF THE
AREA ON THURSDAY AS WAA ADVECTION (850MB TEMPS WARMING TO 0-4C)
CONTINUES. WITH A LOW-LEVEL RIDGE SHIFTING EAST OF THE AREA...850MB
FLOW WILL DRY AND SOUTHWESTERLY ON THURSDAY. MID-LEVEL MOISTURE WILL
ADVECT INTO THE AREA TO INCREASE CLOUDINESS AHEAD OF A WEAK SURFACE
LOW ON THURSDAY.
GFS/ECMWF/NAM ALL ARE IN AGREEMENT THAT A TROUGH WILL CROSS THE
GREAT LAKES AND A WEAK SURFACE LOW WILL MOVE INTO WESTERN PA ON
THURSDAY NIGHT. WITH THIS IN MIND...LIKELY POPS ARE FORECAST
THURSDAY NIGHT. THE SURFACE LOW WILL SHIFT EAST OF THE AREA BY 18Z
FRIDAY...WITH A WEAK SHOT OF CAA IN ITS WAKE. WITH WAA ADVECTION
AHEAD OF THE LOW...THE LOW-LEVEL MELTING LAYER AND 1000-850MB
THICKNESS ARE WARM ENOUGH TO BRING RAIN SHOWERS ACROSS MUCH OF THE
AREA THURSDAY NIGHT INTO EARLY FRIDAY. LOCATIONS NORTH OF
PITTSBURGH WILL BE ON THE PERIPHERY OF CRITICAL THICKNESS
THRESHOLDS AND THUS A WINTRY MIX IS FORECAST THERE. SCHC OF
FREEZING RAIN HAS BEEN INCLUDED FOR I-80 CORRIDOR AND LAUREL
HIGHLANDS/ALLEGHENY FRONT AS SFC TEMPS WILL BE NEAR FREEZING IN
THESE LOCATIONS AT THE ONSET OF THE PRECIP. ANY LINGERING
PRECIPITATION WILL CHANGE OVER TO SNOW ON FRIDAY WITH CAA IN A
NORTHERLY FLOW IN THE WAKE OF THE LOW.
TEMPS ARE FORECAST TO BE AROUND 5 DEGREES ABOVE NORMAL AHEAD OF THE
LOW ON THURSDAY INTO EARLY FRIDAY. TEMPS WILL BE NEAR STEADY IN THE
WAKE OF THE LOW ON FRIDAY...RANGING FROM THE MID 30S ACROSS THE I-80
CORRIDOR IN WESTERN PA TO THE LOWER 40S IN EASTERN OHIO...SW
PA...AND NORTH-CENTRAL WV.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
EXCEPT FOR SOME LEFT OVER SNOW FRIDAY EVENING AS THE LOW
DEPARTS...IT APPEARS THAT BOTH SATURDAY AND SUNDAY SHOULD REMAIN
DRY WITH HIGH PRESSURE DOMINATING THE EAST COAST WEATHER. A LARGE
LOW PRESSURE CENTER WILL DEVELOP IN THE CENTRAL PLAINS AND MOVE
INTO MICHIGAN BY MONDAY MORNING...WITH THE FRONTS IMPACTING ALMOST
THE ENTIRE EASTERN UNITED STATES. HAVE GONE AHEAD AND BUMPED UP
POPS TO LIKELY WITH FAIRLY GOOD AGREEMENT BETWEEN 12Z GFS/ECMWF
ALONG WITH NAEFS ENSEMBLE. MOST OF PRECIPITATION SHOULD FALL AS
RAIN...ALTHOUGH SOME SNOW WILL LIKELY MIX IN. SOME LAKE EFFECT
SNOW WILL BE POSSIBLE MONDAY NIGHT BEHIND THE SYSTEM. HAVE ONLY
INCLUDED A SLIGHT CHANCE FOR POPS WITH A SYSTEM MOVING UP THE EAST
COAST ON TUESDAY. TEMPERATURES SHOULD BE NEAR NORMAL VALUES ON
SATURDAY...RISE ABOVE NORMAL ON SUNDAY AND MONDAY...THEN DROP BACK
TO NORMAL ON TUESDAY.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
LOWERING OVERCAST STRATOCU CAN BE EXPECTED THIS MORNING IN THE
NORTHWEST FLOW AND BRIEF COLD ADVECTION WITH MVFR CEILINGS
PREVAILING. SOME SNOW FLURRIES ARE POSSIBLE THIS MORNING...MAINLY
AT THE NORTHERN PORTS. BY THIS AFTERNOON WITH WARM ADVECTION AND
RIDGING MOVING INTO THE AREA...STRATOCU WILL SCATTER OUT WITH VFR
CONDITIONS AT ALL PORTS BY LATE AFTERNOON.
.OUTLOOK.../WEDNESDAY NIGHT THROUGH SUNDAY/...
GENERAL VFR CONDITIONS WITH HIGH PRESSURE FOR WEDNESDAY AND
THURSDAY. A STORM THURSDAY NIGHT INTO FRIDAY WILL BRING RESTRICTIONS
IN SNOW WITH RAIN POSSIBLE IN THE SOUTH. HIGH PRESSURE WILL BRING A
RETURN TO VFR FOR THE WEEKEND.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
927 AM EST WED FEB 6 2013
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE OHIO VALLEY TODAY. TEMPERATURES
WILL WARM SLIGHTLY GOING INTO THURSDAY...BEFORE A COLD FRONT MOVES
INTO THE REGION THURSDAY NIGHT AND EARLY FRIDAY. THIS FRONT WILL
BRING RAIN...CHANGING TO SNOW. HIGH PRESSURE WILL MOVE IN AGAIN FOR
FRIDAY AND SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EVOLUTION OF LOW CLOUDS ACROSS THE REGION REMAINS A CHALLENGE. AS
SEEN OVERNIGHT THE NAM CONTINUES TO NOT HANDLE THIS LOW LEVEL
MOISTURE AT ALL. AND WHILE THE RAP SEEMS TO DEPICT THE CURRENT
SITUATION WELL...IT DOES GENERALLY HAVE A MOIST BIAS IN THE LOW
LEVELS. SO THERE IS UNCERTAINTY MOVING THROUGH THE DAY ON THE FATE
OF THE LOW CLOUDS. HAVE USED THE RAP AS GUIDE BUT TRIED TO ACCOUNT
FOR ITS BIAS. NONETHELESS IT APPEARS THAT CLOUDS MAY STICK AROUND
FOR MUCH OF THE DAY IN THE SOUTHERN COUNTIES UNTIL WARM AIR
ADVECTION COMMENCES HEADING TOWARDS 00Z. MEANWHILE EROSION TO THE
CLOUD DECK FROM THE NORTH MAY STILL CONTINUE TOWARDS THE I-70
CORRIDOR. BASED ON THIS FORECAST CLOUD PROGRESSION HAVE LOWERED
HIGHS SLIGHTLY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
THE CWA WILL BE IN A WARM ADVECTION PATTERN ON THURSDAY...WITH
INCREASING MOISTURE ALOFT AS TEMPS WARM AT THE SURFACE. THE GFS
STILL APPEARS TO BE OVERLY COLD AT THE SURFACE...DESPITE BEING
AS WARM AS (OR SLIGHTLY WARMER THAN) THE OTHER MODELS ALOFT. WITH
THE SURFACE FRONT IN THE VICINITY...IT IS NOT A HUGE SURPRISE THAT
SMALL DIFFERENCES IN PLACEMENT CAN HAVE BIG IMPACTS ON THE TEMP
FORECAST. THE MAX TEMPS FOR THURSDAY ARE SIMILAR TO A NAM/ECMWF
BLEND...AND SLIGHTLY WARMER THAN THE SREF MEAN.
MODEL AGREEMENT IS STILL FAIRLY GOOD (THOUGH NOT PERFECT) WITH THE
APPROACH OF A COLD FRONT ON THURSDAY NIGHT. IN ADDITION TO THE
FRONT...A SURFACE LOW MOVING THROUGH THE SOUTHERN STATES WILL
PROVIDE AN ADDITIONAL PUSH OF MOISTURE FROM THE SOUTH. THIS
FEATURE IS BEING PHASED DIFFERENTLY FROM MODEL TO MODEL...SO ITS
IMPACTS ON THE ILN CWA ARE UNCERTAIN. HOWEVER...THE IMPACTS ON THE
FORECAST WILL PROBABLY NOT BE TOO BIG...SINCE THE PHASING (IF IT
OCCURS) WILL HAPPEN AT AROUND THE SAME TIME THE FRONT IS MOVING
INTO THE CWA ANYWAY. SINCE THE POPS FOR THE FRONT HAVE BEEN
INCREASED TO 100...THE POTENTIAL PHASING CANNOT INCREASE THE
FORECAST HIGHER THAN THAT. EVEN THE NAM12...WHICH HAS VIRTUALLY NO
IMPACT OVER THE ILN CWA FROM THE SOUTHERN SYSTEM...IS PRETTY MUCH
IDENTICAL ON FRONTAL TIMING.
IN COMPARING THE LOCATION OF THE HIGH RH...FORCING...AND SURFACE
TEMPERATURES...IT NOW APPEARS THAT ALL MODELS ARE ENDING THE
HEAVY PRECIPITATION ACROSS THE CWA BEFORE TEMPERATURES BECOME COLD
ENOUGH TO SUPPORT SNOW. THE CHANGEOVER IN THE FAR NORTHERN CWA
SHOULD BE SOON ENOUGH TO SUPPORT SOME LIGHT ACCUMULATIONS...BUT A
FIRST GUESS AT THE TOTALS DID NOT SUPPORT ANYTHING OVER AN INCH.
MOST OF THE CWA WILL LIKELY COME IN WITH LITTLE TO NO ACCUMULATION
AT ALL.
SOME UPWARD ADJUSTMENTS WERE MADE TO THE SKY GRIDS FRIDAY...AS
THERE DOES LOOK TO BE PLENTIFUL LOW LEVEL MOISTURE BEHIND THE COLD
FRONT.
THE CWA WILL BE UNDER THE CONTROL OF HIGH PRESSURE ON FRIDAY NIGHT
AND SATURDAY. THIS AIR MASS WILL BE RELATIVELY COOL (TEMPS AT
850MB DO NOT GO ABOVE FREEZING UNTIL AFTER 00Z). TEMPS WERE
ADJUSTED DOWN SLIGHTLY FOR MAXES ON SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
SHOWERS ASSOCIATED WITH THE NEXT COLD FRONT MAY ARRIVE AS EARLY
AS SUNDAY AFTERNOON. WITH GFS AND ECMWF IN GOOD
AGREEMENT...SHOWERS WILL BE LIKELY SUNDAY NIGHT WHEN THE FRONT
CROSSES THE REGION. SHOWERS WILL DIMINISH ON MONDAY AS HIGH
PRESSURE RETURNS BEHIND THE FRONT. TUESDAY FORECAST IS MAINLY DRY
UNDER RETREATING HIGH PRESSURE...THOUGH THERE WILL BE A SLIGHT
CHANCE OF SHOWERS BREAKING OUT AHEAD OF THE NEXT WEATHER PRODUCING
SYSTEM PROGGED BY THE ECMWF TO ARRIVE NEXT TUESDAY NIGHT.
TEMPERATURES WILL BE NEAR NORMAL FRIDAY WITH HIGHS IN THE MID 30S TO
AROUND 40. READINGS WILL RISE ABOVE NORMAL SATURDAY THROUGH MONDAY
AS WARM ADVECTION PUSHES HIGHS TO THE 40S AND 50S. A RETURN TO
NORMALLY COOL CONDITIONS IS FORECAST FOR TUESDAY AS COLD ADVECTION
ACCOMPANIES A NORTHERLY LOW LEVEL FLOW.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
SURFACE HIGH PRESSURE LOCATED FROM THE WESTERN GREAT LAKES TO THE
LOWER OHIO RIVER VALLEY WILL BUILD EAST ACROSS THE REMAINDER OF
THE OHIO VALLEY TODAY. THE HIGH WILL THEN MOST EAST OF THE REGION
TONIGHT.
MAIN FORECAST PROBLEM TODAY WILL BE HOW FAST MVFR STRATOCUMULUS
CLOUDS WILL ERODE...DISSIPATE OR MOVE OUT OF THE REGION. OVERALL
SATELLITE TREND OVER OHIO AND INDIANA WAS A SLOWLY SHRINKING AREA
OF STRATOCUMULUS...PERHAPS A COMPONENT OF INCREASING SUBSIDENCE.
MODELS ARE ALL OVER THE PLACE IN TERMS OF NOT CAPTURING THE
CURRENT MOISTURE AND PERHAPS HOLDING ON TO IT TOO LONG DUE TO KNOW
MOISTURE BIASES. ATTM...HAVE DECIDED TO SLOWLY CLEAR THE
STRATOCUMULUS...THINKING ERODING/DISSIPATING WILL OCCUR SOMEWHERE
BETWEEN 18Z AND 00Z. THERE IS AN OUTSIDE CHANCE THAT IF THE CLOUDS
DO NOT ERODE/DISSIPATE DURING THIS TIME...THEY COULD HANG AROUND A
LITTLE LONGER AFTER 00Z UNTIL DRIER AIR AND WAA PUSH THE CLOUDS TO
THE EAST.
FOR TONIGHT...ANY LINGER STRATOCUMULUS WILL GIVE WAY TO SOME MID
AND HIGH LEVEL CLOUDS STREAMING IN FROM THE WEST AND SOUTHWEST.
OUTLOOK...MVFR CONDITIONS ARE POSSIBLE THURSDAY NIGHT INTO FRIDAY
AND AGAIN SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...
SHORT TERM...HATZOS
LONG TERM...CONIGLIO
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS TULSA OK
544 AM CST WED FEB 6 2013
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
KMLC AND KFSM WILL CONTINUE TO SEE AT LEAST OCCASIONAL IFR OR LIFR
CEILINGS AND VISIBILITIES IN FOG THROUGH MID MORNING. ONCE THE FOG
LIFTS...MVFR CEILINGS WILL REMAIN AT KMLC WITH MAINLY VFR CEILINGS
ELSEWHERE FOR THE REST OF THE DAY. MVFR CEILINGS WILL DEVELOP AT
ALL SITES BY 06Z-08Z TONIGHT...AND SCATTERED SHOWERS WILL AFFECT
MAINLY THE NORTHEAST OKLAHOMA SITES LATE TONIGHT. THE CHANCE OF
THUNDER APPEARS TOO LOW TO MENTION IN THE TAFS AT THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 306 AM CST WED FEB 6 2013/
DISCUSSION...
FAIRLY ACTIVE FORECAST THIS MORNING...BEGINNING WITH ONGOING DENSE
FOG ONCE AGAIN. WIDESPREAD VISIBILITIES OF A QUARTER MILE OR LESS
CURRENTLY AFFECTING MUCH OF SOUTHEAST OKLAHOMA AND PARTS OF
SEBASTIAN COUNTY IN WEST CENTRAL ARKANSAS. EASTERN EDGE OF THE FOG
IS MORE PATCHY THAN AREAS TO THE WEST...AND VISIBILITIES IN THIS
AREA HAVE NOT BEEN AS CONSISTENTLY LOW. AS A RESULT...PARTS OF
EAST CENTRAL OKLAHOMA...AS WELL AS SEBASTIAN COUNTY...MAY NEED TO
BE REMOVED FROM THE ADVISORY A BIT LATER. SATELLITE INDICATING
THE FOG/LOW CLOUDS SPREADING MORE RAPIDLY NORTHWARD ACROSS AREAS
WEST OF THE HIGHWAY 75 CORRIDOR...WITH NEAR ZERO VISIBILITIES
COMMON. HAVE ADDED CREEK AND PAWNEE COUNTIES TO THE ADVISORY AS A
RESULT. RUC RELATIVE HUMIDITY PROGS AND EXTRAPOLATION OF THE
CURRENT SATELLITE IMAGERY WOULD SUGGEST THAT TULSA AND OSAGE
COUNTIES MAY NEED TO BE ADDED LATER THIS MORNING...BUT THESE WERE
LESS OF A CERTAIN SO HELD OFF FOR NOW. WILL MONITOR. THE FOG WILL
BE SLOW TO ERODE ACROSS THE MOST AFFECTED AREAS /GENERALLY WEST OF
A HUGO TO EUFAULA TO PAWNEE LINE/...SO HAVE LINGERED A PATCHY FOG
MENTION THROUGH NOON IN THESE AREAS. THIS WILL ALSO AFFECT HIGH
TEMPERATURES...HOLDING READINGS DOWN A FEW DEGREES FROM LOCATIONS
FURTHER EAST.
WATER VAPOR SATELLITE SHOWS DEEPER MOISTURE SPREADING NORTHWARD
TOWARD THE REGION IN ASSOCIATION WITH A SHORTWAVE MOVING THROUGH
CENTRAL AND EASTERN TEXAS. SCATTERED SHOWERS/ISOLATED STORMS WILL
LIKELY GRAZE THE SOUTHEASTERN FRINGES OF THE FORECAST AREA
POSSIBLY AS EARLY AS LATE MORNING...BUT MORE LIKELY THIS AFTERNOON
AND EVENING.
GREATER AND MORE WIDESPREAD RAINFALL WILL DEVELOP AND MOVE INTO
PARTS OF NORTHEAST OKLAHOMA LATE TONIGHT IN ADVANCE OF A WEAK COLD
FRONT...SPREADING ACROSS THE REST OF THE FORECAST AREA DURING THE
DAY TOMORROW. INSTABILITY SHOULD BE ENOUGH TO SUPPORT AT LEAST A
CHANCE OF THUNDER...BUT SEVERE WEATHER IS NOT LIKELY. BENEFICIAL
RAINS...WITH SOME AREAS POSSIBLY SEEING AS MUCH AS AN INCH...WILL
BE THE MAIN OUTCOME OF THIS EVENT. TEMPERATURES IN THE WAKE OF THE
COLD FRONT WILL REMAIN ABOVE NORMAL.
DRY CONDITIONS WILL PREVAIL FRIDAY THROUGH SATURDAY MORNING...WITH
RAIN AND THUNDERSTORM CHANCES INCREASING AGAIN SATURDAY AFTERNOON
AND ESPECIALLY SATURDAY NIGHT AND SUNDAY. THE GFS HAS FINALLY
CAUGHT ON TO THE CONSISTENT ECMWF SOLUTION FEATURING A DRYLINE
PASSAGE DURING THE DAY SUNDAY...AS AN UPPER LOW MOVES THROUGH THE
CENTRAL PLAINS. THEIR 00Z SOLUTIONS ARE REMARKABLY SIMILAR.
THUNDERSTORMS ARE LIKELY TO DEVELOP SATURDAY NIGHT IN ADVANCE OF
THE DRYLINE DUE TO A STRONG LOW LEVEL JET...WITH THUNDERSTORMS
LIKELY ENDING ACROSS MOST OF THE AREA BY MIDDAY SUNDAY. SEVERE
WEATHER WILL STILL BE POSSIBLE...BUT THE EARLY DRYLINE PASSAGE
WILL LIKELY BE A LIMITING FACTOR. THE RAINS SHOULD ALSO LIMIT ANY
FIRE WEATHER POTENTIAL BEHIND THE DRYLINE SUNDAY
AFTERNOON...ALTHOUGH THAT THREAT WILL DEFINITELY NOT BE NON
EXISTENT.
MUCH COOLER WEATHER WILL BE ON THE WAY FOR THE BEGINNING OF NEXT
WEEK...ON THE HEELS OF THIS SYSTEM. A FAST MOVING UPPER TROUGH
WILL PASS THROUGH THE AREA TUESDAY NIGHT /THE ECMWFS FASTER
SOLUTION IS AN OUTLIER THIS MORNING/. TEMPERATURE PROFILES SUGGEST
LIGHT SNOW POTENTIAL WITH ANY PRECIPITATION THAN FALLS...IF THE
TUESDAY NIGHT TIMING ENDS UP VERIFYING.
A RELATIVELY QUICK WARMUP LOOKS LIKELY FOR THE LATTER PART OF
NEXT WEEK...AS SOUTH WINDS MAKE A QUICK RETURN TO THE AREA
FOLLOWING THE AFOREMENTIONED TROUGHS PASSAGE.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...DENSE FOG ADVISORY UNTIL 9 AM WEDNESDAY FOR OKZ049-OKZ053-OKZ059-
OKZ064-OKZ065-OKZ066-OKZ071-OKZ073-OKZ074-OKZ075-OKZ076.
AR...DENSE FOG ADVISORY UNTIL 9 AM WEDNESDAY FOR ARZ029.
&&
$$
AVIATION...05
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
210 PM EST WED FEB 6 2013
.SYNOPSIS...
18Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUE TO SHOW AN UNAMPLIFIED
PATTERN OVER THE CONUS. MAIN FEATURE OF NOTE INCLUDE PACIFIC ENERGY
BEGINNING TO ARRIVE OVER THE COASTS OF BRITISH
COLUMBIA/WASHINGTON...A DECENT IMPULSE PROGRESSING ACROSS THE
SOUTHERN PLAINS...AND A BROAD LONGWAVE TROUGH IN PLACE OVER EASTERN
CANADA AND THE NORTHEASTERN STATES. OUR REGION CONTINUES TO RESIDE
WITHIN A MAINLY ZONAL FLOW PATTERN. A VERY WEAK SHORTWAVE EMBEDDED
IN THIS FLOW IS PASSING TROUGH THE REGION THIS MORNING AND WILL BE
TO OUR EAST BY THIS EVENING. LOCAL AREA WILL ACTUALLY GET INTO A
BRIEF RIDGING PATTERN ALOFT FOR LATER TODAY AND TONIGHT IN RESPONSE
TO THE UPSTREAM HEIGHT FALLS ASSOCIATED WITH THE SOUTHERN PLAINS
SYSTEM.
AT THE SURFACE...WEAK HIGH PRESSURE EXTENDS DOWN THE ATLANTIC
SEABOARD TO THE FLORIDA PENINSULA. A WEAK INVERTED TROUGH FEATURE
CAN ALSO BE ANALYZED OVER THE EASTERN GULF AND IS LIKELY A
REFLECTION OF THE PASSING ENERGY ALOFT OVERTOP THE SEA SURFACE TEMP
GRADIENT ACROSS THE EASTERN GULF. THE LOW LEVEL FOCUS ALONG THIS
SURFACE TROUGH HAS BEEN ENOUGH TO SUPPORT A REGION OF SHOWER
DEVELOPMENT FROM NEAR THE CITRUS/HERNANDO COUNTY COASTS SOUTHWEST TO
THE COASTAL WATERS OFF PINELLAS COUNTY. THIS TROUGH WAS A BIT MORE
ORGANIZED THAN WAS PREVIOUSLY ANTICIPATED AND RESULTED IN SHOWER
ACTIVITY THAT WAS A BIT MORE ROBUST. NOW THAT THE UPPER ENERGY IS
PASSING...THIS TROUGH APPEARS TO BE WEAKENING AND THE CHANCES FOR
ANY SIGNIFICANT SHOWER ACTIVITY REACHING THE COAST THIS AFTERNOON
IS DECREASING.
&&
.SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...
TONIGHT...SHORTWAVE ENERGY TO OUR WEST WILL QUICKLY TRANSLATE ALONG
THE NORTHERN GULF COAST...WITH AN ASSOCIATED ORGANIZING AREA OF
SURFACE LOW PRESSURE MOVING TO NEAR THE MS DELTA BY SUNRISE. BEST
MOISTURE...AND SYNOPTIC LIFT ASSOCIATED WITH THIS SYSTEM WILL REMAIN
TO OUR WEST AND NORTHWEST INTO THURSDAY MORNING AND WILL KEEP THE
FORECAST DRY REGION-WIDE. A SLOW INCREASE IN LOW LEVEL ATLANTIC
MOISTURE AND MORE BOUNDARY LAYER MOMENTUM WILL HELP KEEP
TEMPERATURES UP TONIGHT. MANY LOCATIONS SOUTH OF I-4 WILL HOLD IN
THE UPPER 50S TO LOW 60S...AND IN THE 50S FURTHER NORTH ACROSS THE
NATURE COAST.
THURSDAY/THURSDAY NIGHT...
SHORTWAVE ENERGY QUICKLY PASSES THROUGH THE SOUTHEASTERN STATES...
BUT STAYS NORTH OF OUR REGION. ASSOCIATED SURFACE LOW AND WARM
FRONTAL FEATURE EXTENDING TO THE EAST WILL ALSO PASS TO OUR NORTH
THROUGH THE DAY. THE BEST DEEP LAYER MOISTURE...SYNOPTIC LARGE SCALE
LIFT AND LOW LEVEL UPGLIDE WILL ALL PASS THROUGH THE I-10 CORRIDOR
AND NORTHWARD WHICH WILL MEAN A QUICK DROP OFF IN RAIN CHANCES
FURTHER SOUTH INTO OUR AREA. WILL KEEP THE CHANCE POPS FOR SCATTERED
SHOWERS OVER CITRUS AND LEVY COUNTIES...BUT THEN QUICKLY TRANSITION
TO A COMPLETELY DRY FORECAST BY THE TIME ONE REACHES THE I-4
CORRIDOR. BEING IN THE WARM SECTOR OF THIS SYSTEM AND WITHIN THE
THERMAL RIDGE AHEAD OF THE TRAILING COLD FRONT...WOULD EXPECT A
RATHER WARM DAY ON THURSDAY. LIKELY WILL SEE A LOT OF INSTABILITY
CLOUDS DEVELOPING THROUGH THE DAY...BUT THESE SHOULD NOT LIMIT OUR
TEMP RISE AND MANY LOCATIONS WILL REACH THE UPPER 70S TO LOWER 80S.
TYPICAL FOR THIS TIME OF YEAR...WITH A DEVELOPING FLOW OFF THE WATER
AT MANY COASTAL LOCATIONS WILL KEEP AFTERNOON TEMPERATURES DOWN A
FEW DEGREES. THURSDAY NIGHT...INITIAL IMPULSE OF UPPER LEVEL ENERGY
QUICKLY EXITS UP THE EASTERN SEABOARD...BEGINNING THE PROCESS TOWARD
A POTENTIALLY POWERFUL NOR`EASTER FOR THE NEW ENGLAND STATES ON
FRIDAY/SATURDAY. FOR OUR REGION IT MEANS LITTLE ATMOSPHERIC PUSH...
AND THE LEFTOVER FRONT PROGRESSING VERY SLOWLY INTO OUR NORTHERN
ZONES. WILL KEEP A SMALL CHANCE FOR SHOWERS OVER THE NORTHERN HALF
OF THE AREA THURSDAY NIGHT...BUT WITH THE LACK OF BOTH LOW LEVEL AND
UPPER LEVEL FORCING...ITS DOES NOT LOOK TO BE ANYTHING SIGNIFICANT.
FRIDAY/FRIDAY NIGHT...
WEAK COLD FRONT CONTINUES A VERY SLOW PROGRESSION SOUTHWARD THROUGH
THE PENINSULA DURING THE DAYLIGHT HOURS. FIRST HALF OF FRIDAY WILL
LIKELY FEATURE QUITE A BIT OF CLOUDS...BUT ONLY ISOLATED SHOWERS
ALONG THE FRONT...CONTINUING THE TREND FROM THURSDAY NIGHT. BETTER
CHANCES FOR SHOWERS MAY DEVELOP OVER THE SOUTHERN HALF OF THE AREA
DURING THE AFTERNOON WHEN DIURNAL INSTABILITY WILL ADD TO THE
FRONTAL FOCUS AHEAD OF THE BOUNDARY. WILL BUMP POPS UP TO BETWEEN
30-40% FOR PLACES LIKELY PUNTA GORDA AND FT. MYERS TO ACCOUNT FOR
THIS BEFORE THE FRONT FINALLY SLIPS SOUTH OF THE AREA FRIDAY
EVENING. THE COMBINATION OF SIGNIFICANT LOW DEVELOPMENT OFF THE
ATLANTIC SEABOARD AND ONE FINAL SHORTWAVE PASSING THROUGH WILL GIVE
THE FRONT A GOOD SOUTHWARD PUSH FRIDAY NIGHT WHICH WILL DELIVER A
COOLER AND DRIER AIRMASS TO THE PENINSULA FOR THE FIRST HALF OF THE
UPCOMING WEEKEND.
&&
.LONG TERM (SATURDAY-TUESDAY)...
THE COLD FRONT WILL BE PUSHING SOUTH OF THE AREA TO START THE PERIOD
WITH COOLER AND DRIER HIGH PRESSURE BUILDING IN FROM THE NORTH. THE
HIGH PRESSURE CENTER WILL SHIFT EAST TO OVER THE ATLANTIC THROUGH
THE WEEKEND KEEPING AN E/SE FLOW ACROSS THE LOCAL AREA. EVENING
SURGES WILL CAUSE A FEW HOURS OF GUSTY WINDS MAINLY ALONG THE COAST
AND COASTAL WATERS EACH NIGHT AFTER SUNSET. HIGH PRESSURE WILL THEN
CONTINUE TO RIDGE ACROSS THE AREA THROUGH TUESDAY AS A TROUGH STALLS
JUST TO THE NORTH OF THE STATE. TEMPERATURES WILL BE IN THE MID 70S
TO LOWER 80S FOR HIGHS EACH DAY. LOW WILL BE MODERATING FROM THE
UPPER 40S NORTH TO THE MID TO UPPER 50S CENTRAL AND SOUTH FRIDAY
THROUGH SUNDAY...INCREASING TO THE LOWER 50S NORTH TO THE MID 50S TO
LOWER 60S CENTRAL AND SOUTH.
&&
.AVIATION...
PRIMARILY VFR AS THE BULK OF THE SHOWER ACTIVITY REMAINS NORTH OF
THE TERMINALS TODAY. VISIBILITIES MAY BECOME RESTRICTED BY FOG
OVERNIGHT AT PGD BUT CONFIDENCE TOO LOW TO INCLUDE MVFR OR IFR AT
THIS TIME.
&&
.MARINE...
ATLANTIC HIGH PRESSURE RIDGING ACROSS THE WATERS SLOWLY WEAKENS AS
LOW PRESSURE FORMS ON THE NORTHERN GULF COAST AND TRACKS TO THE
NORTHEAST. A COLD FRONT MOVES INTO THE EASTERN GULF ON FRIDAY AND
EXITS EAST OF THE REGION FRIDAY NIGHT. HIGH PRESSURE THEN BUILDS IN
ONCE AGAIN DURING THE WEEKEND. WILL BEGIN TO SEE AN INCREASE IN
WINDS LATER TONIGHT AND POTENTIAL PERIODS OF CAUTIONARY WINDS
THURSDAY AND THURSDAY NIGHT...ESPECIALLY OVER THE NORTHERN AND
OFFSHORE WATERS.
&&
.FIRE WEATHER...
LOW-LEVEL MOISTURE HAS INCREASED SIGNIFICANTLY
RESULTING IN HUMIDITIES WELL ABOVE CRITICAL LEVELS. A WEAK COLD
FRONT WILL MOVE SLOWLY SOUTHWARD THROUGH THE REGION DURING THURSDAY
NIGHT AND FRIDAY THEN FINALLY SOUTH OF THE AREA FRIDAY NIGHT. SOME
SHOWERS ARE POSSIBLE AHEAD OF THE FRONT FROM TIME TO TIME. NO FIRE
WEATHER ISSUES ARE EXPECTED THROUGH THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 63 79 65 76 / 10 10 20 20
FMY 62 82 65 80 / 10 10 10 30
GIF 58 81 61 80 / 10 10 20 20
SRQ 61 78 64 76 / 10 10 20 30
BKV 57 81 62 78 / 10 10 30 10
SPG 64 77 65 76 / 10 10 20 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...BEACH HAZARDS STATEMENT THROUGH THURSDAY EVENING FOR
CHARLOTTE-LEE-SARASOTA.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE...MROCZKA
AVIATION/FIRE WEATHER...JILLSON
LONG TERM...COLSON
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
356 PM CST WED FEB 6 2013
...UPDATE TO LONG TERM...
.SYNOPSIS...
ISSUED AT 911 AM CST WED FEB 6 2013
THE 06.12Z 250 RAOB SYNOPTIC MAP SHOWED ANTICYCLONIC JET FLOW ACROSS
THE CENTRAL US AND EXTENDING INTO PORTIONS OF THE UPPER MIDWEST. A JET
STREAK OF AROUND 125 KT WAS OBSERVED ACROSS WISCONSIN. FAIRLY LIGHT
UPPER LEVEL FLOW WAS OBSERVED ACROSS SOUTHERN KANSAS WITH ONLY 30 KT
AT KDDC. AT 500 HPA, A LARGE CYCLONE WAS LOCATED ACROSS THE NORTHEAST
PACIFIC. A FEW SHORTWAVES WERE NOTED ACROSS THE GREAT BASIN AND TEXAS.
AT 700 HPA, TEMPERATURES WERE AT ZERO CENTIGRADE ACROSS THE TEXAS PANHANDLE
AND SOUTHWEST KANSAS...INDICATING A WAA PATTERN STILL IN PLACE. THE
WARM PLUME AT 850 HPA WAS VERY EVIDENT ACROSS THE CENTRAL PLAINS WITH
VALUES IN THE 8 TO 12 DEG C RANGE. AT THE SFC, A WARM FRONT WAS LOCATED
ALONG WITH THE KANSAS/OKLAHOMA STATE LINE WITH HIGHER DEWPOINTS ADVECTING
IN FROM OKLAHOMA.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 236 PM CST WED FEB 6 2013
TONIGHT:
SEVERAL SENSIBLE WEATHER IMPACTS EXPECTED TONIGHT INTO TOMORROW MORNING.
FIRST IS FOG. HRRR IS VERY AGGRESSIVE IN DEVELOPING LOW VISIBILITIES
AFTER 00Z TONIGHT. THE NAM AND ARW-WRF IS NOT AS AGGRESSIVE WITH FOG.
DUE TO THE WARM AIR ADVECTION PATTERN THAT IS CURRENTLY TAKING PLACE
AND THE HIGHER DEWPOINTS ADVECTING IN ACROSS THE REGION...WILL GO WITH
PATCHY FOG TONIGHT ALONG AND EAST OF HIGHWAY 283 WITH AREAS OF FOG
ALONG SOUTH CENTRAL KANSAS WHERE DEWPOINTS ARE HIGHER. THE NEXT CONCERN
IS CONVECTION. THE BEST CHANCE FOR OVERNIGHT THUNDERSTORMS IS GENERALLY
ALONG AND EAST OF HIGHWAY 183. HERE WARM AIR ADVECTION...ISENTROPIC
LIFT ALONG THE 295 KELVIN THETA SURFACE... AND INCREASING 850-650 HPA
FRONTOGENESIS SHOULD INITIATE CONVECTIVE ACTIVITY AFTER 03Z TONIGHT.
ALL THE MESOSCALE MODELS SUGGESTS THIS AS WELL AS THE GFS AND ECMWF.
SEVERE THUNDERSTORMS ARE NOT EXPECTED DUE TO WEAK THERMODYNAMICS AND
WEAK KINEMATICS. CONVECTION SHOULD BE CLEAR OF THE REGION BY DAWN.
A DENSE FOG ADVISORY COULD BE NEEDED FOR TOMORROW MORNING, BUT DO NOT
HAVE ENOUGH CONFIDENCE TO ISSUE ONE THIS EARLY.
TOMORROW:
TOMORROW MORNING WILL BE BREEZY AS THERE WILL BE A TIGHT PRESSURE GRADIENT
ACROSS THE REGION ALONG WITH 45 KT 850 HPA WINDS PARTIALLY MIXING DOWN.
NOT EXPECTING WIND ADVISORY LEVELS AT THIS TIME. OTHER THAN SOME POSSIBLE
LINGERING FOG, TOMORROW WILL BE FAIRLY QUIET WITH CLEARING SKIES. HIGHS
SHOULD BE IN THE 50S DEG F. WINDS SHOULD ABATE AS THE DAY WEARS ON.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 355 PM CST WED FEB 6 2013
MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL RIDGE OF HIGH PRESSURE
MOVING EASTWARD ACROSS THE CENTRAL PLAINS FRIDAY RESULTING IN DRY
CONDITIONS ACROSS WESTERN KANSAS THROUGH FRIDAY NIGHT. MEANWHILE,
A STRONG UPPER LEVEL TROUGH OF LOW PRESSURE IS EXPECTED TO DIG
SOUTHEAST INTO THE GREAT BASIN REGION FRIDAY, THEN TURN EASTWARD
MOVING INTO THE CENTRAL AND SOUTHERN ROCKIES SATURDAY BRINGING THE
POSSIBILITY FOR SHOWERS AND THUNDERSTORMS TO PORTIONS OF WESTERN
KANSAS AS EARLY AS SATURDAY AFTERNOON. A RETURN FLOW WILL SET UP
EARLY FRIDAY DRAWING GULF MOISTURE NORTHWARD INTO MUCH OF KANSAS
WITH H85 DEWPOINTS CLIMBING JUST ABOVE 0C. ADDITIONALLY, SURFACE
LOW PRESSURE IN EASTERN COLORADO WILL STRENGTHEN THROUGHOUT THE
DAY WITH A SHARPENING DRYLINE EXTENDING SOUTHWARD GENERALLY INTO
THE TEXAS PANHANDLE. DYNAMIC SUPPORT ALOFT WILL BECOME MORE
FAVORABLE AS WELL WITH THE GFS AND ECMWF SHOWING A STRONG H5 VORT
MAX LIFTING NORTHEAST OUT OF THE TROUGH AXIS AND ACROSS THE
WESTERN HIGH PLAINS SATURDAY NIGHT. A +100KT UPPER LEVEL JET WILL
ALSO BE STREAMING EAST-NORTHEAST ACROSS WEST TEXAS AND THE TEXAS
PANHANDLE INTO THE PLAINS OF WESTERN OKLAHOMA AND SOUTHERN KANSAS
LATE SATURDAY. AS A RESULT, SHOWERS AND THUNDERSTORMS ARE EXPECTED
TO DEVELOP ACROSS THE SOUTH PLAINS SATURDAY AFTERNOON AND EVENING,
LIFTING NORTHEASTWARD INTO CENTRAL KANSAS WITH CHANCES FOR THE
PRECIP DWINDLING TOWARD THE WEST. GFS AND ECMWF MODEL SOUNDINGS
INDICATE A REAL LACK OF INSTABILITY LIMITING SEVERE POTENTIAL.
ANY PRECIP WILL LIKELY COME TO AN END BY MID DAY SUNDAY AS THE
UPPER LEVEL TROUGH BEGINS TO LIFT NORTHEAST INTO THE UPPER
MIDWEST.
TEMPERATURES ARE EXPECTED TO BE NEAR NORMAL FRIDAY EVEN AS SURFACE
HIGH PRESSURE MOVES FROM THE NORTHERN PLAINS SOUTHEAST INTO THE
UPPER MIDWEST. THIS WILL TURN WINDS SOUTH TO SOUTHEASTERLY ACROSS
WESTERN KANSAS THROUGHOUT MUCH OF THE DAY. HOWEVER, THIS WILL DO
LITTLE TO ERODE THE COOLER AIR MASS THAT IS PROJECTED TO SINK
SOUTH INTO WESTERN KANSAS BEHIND A PASSING COLD FRONT THURSDAY.
THE NAM, GFS, AND ECMWF SHOW H85 TEMPERATURES RANGING FROM JUST
ABOVE 0C ACROSS CENTRAL KANSAS TO JUST ABOVE 5C ALONG THE COLORADO
BORDER. LOOK FOR HIGHS WELL UP INTO THE 50S(F) FRIDAY AFTERNOON.
SIMILAR HIGHS ARE LIKELY SATURDAY AS SURFACE LOW PRESSURE
STRENGTHENS ACROSS EASTERN COLORADO KEEPING SOUTHERLY WINDS IN
PLACE ACROSS WESTERN KANSAS. A COLD FRONT PUSHING THROUGH WESTERN
KANSAS SUNDAY WILL ALLOW COLDER AIR TO SURGE SOUTHWARD INTO
WESTERN KANSAS RESULTING IN LOWER HIGH TEMPERATURES. OVERALL,
TEMPERATURES ARE LIKELY TO REMAIN BELOW NORMAL THROUGH MID WEEK AS
A SECONDARY UPPER LEVEL TROUGH DEVELOPS ACROSS THE INTERMOUNTAIN
WEST AND MOVES INTO THE WESTERN HIGH PLAINS DRAWING MORE COLDER
DOWN INTO THE REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1203 PM CST WED FEB 6 2013
AN AREA OF LOW MVFR CLOUD COVER ACROSS WESTERN AND CENTRAL KANSAS,
CONTINUES TO ERODE THIS LATE MORNING WITH LITTLE IF ANY REMNANT
CLOUD COVER EXPECTED DURING THE AFTERNOON. HOWEVER, AN AREA OF LOW
PRESSURE OVER EASTERN COLORADO, WILL CONTINUE TO DEEPEN IN ADVANCE
OF A COLD FRONT MOVING THROUGH THE CENTRAL HIGH PLAINS THIS
EVENING TO OVERNIGHT. INITIALLY THIS WILL RESULT IN BRISK SOUTH
WINDS OF 15 TO 20 KNOTS ALONG WITH HIGHER GUSTS THROUGH THE
REMAINDER OF THIS AFTERNOON FOR SOUTHWEST INTO CENTRAL KANSAS.
HOWEVER, AS THE FRONT APPROACHES AND WINDS TURN LIGHT AHEAD OF THE
BOUNDARY, VISIBILITY VALUES ARE LIKELY TO DROP INTO AN IFR RANGE
OF 1 TO 3 MILES MAINLY EAST OF HIGHWAY 283. FURTHER, SOME
RESTRICTIONS DOWN TO A MILE OR LESS WILL BE POSSIBLE NEAR AND EAST
OF THE DODGE CITY TERMINAL DURING THE LATE EVENING TO OVERNIGHT
HOURS. OTHERWISE, A FEW RAIN SHOWERS ASSOCIATED WITH THE COLD
FRONT PASSAGE, MAY CLIP THE HYS AND DDC TERMINALS THIS EVENING TO
EARLY OVERNIGHT BEFORE WINDS TURN TO THE NORTH AND CONDITIONS TURN
DRY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 40 54 27 56 / 10 0 0 0
GCK 36 53 27 56 / 0 0 0 0
EHA 34 51 27 57 / 0 0 0 0
LBL 37 53 27 57 / 0 0 0 0
HYS 39 53 25 55 / 40 0 0 0
P28 48 55 30 56 / 80 50 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...JJOHNSON
AVIATION...AJOHNSON
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
236 PM CST WED FEB 6 2013
...UPDATE TO SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 911 AM CST WED FEB 6 2013
THE 06.12Z 250 RAOB SYNOPTIC MAP SHOWED ANTICYCLONIC JET FLOW ACROSS
THE CENTRAL US AND EXTENDING INTO PORTIONS OF THE UPPER MIDWEST. A JET
STREAK OF AROUND 125 KT WAS OBSERVED ACROSS WISCONSIN. FAIRLY LIGHT
UPPER LEVEL FLOW WAS OBSERVED ACROSS SOUTHERN KANSAS WITH ONLY 30 KT
AT KDDC. AT 500 HPA, A LARGE CYCLONE WAS LOCATED ACROSS THE NORTHEAST
PACIFIC. A FEW SHORTWAVES WERE NOTED ACROSS THE GREAT BASIN AND TEXAS.
AT 700 HPA, TEMPERATURES WERE AT ZERO CENTIGRADE ACROSS THE TEXAS PANHANDLE
AND SOUTHWEST KANSAS...INDICATING A WAA PATTERN STILL IN PLACE. THE
WARM PLUME AT 850 HPA WAS VERY EVIDENT ACROSS THE CENTRAL PLAINS WITH
VALUES IN THE 8 TO 12 DEG C RANGE. AT THE SFC, A WARM FRONT WAS LOCATED
ALONG WITH THE KANSAS/OKLAHOMA STATE LINE WITH HIGHER DEWPOINTS ADVECTING
IN FROM OKLAHOMA.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 236 PM CST WED FEB 6 2013
TONIGHT:
SEVERAL SENSIBLE WEATHER IMPACTS EXPECTED TONIGHT INTO TOMORROW MORNING.
FIRST IS FOG. HRRR IS VERY AGGRESSIVE IN DEVELOPING LOW VISIBILITIES
AFTER 00Z TONIGHT. THE NAM AND ARW-WRF IS NOT AS AGGRESSIVE WITH FOG.
DUE TO THE WARM AIR ADVECTION PATTERN THAT IS CURRENTLY TAKING PLACE
AND THE HIGHER DEWPOINTS ADVECTING IN ACROSS THE REGION...WILL GO WITH
PATCHY FOG TONIGHT ALONG AND EAST OF HIGHWAY 283 WITH AREAS OF FOG
ALONG SOUTH CENTRAL KANSAS WHERE DEWPOINTS ARE HIGHER. THE NEXT CONCERN
IS CONVECTION. THE BEST CHANCE FOR OVERNIGHT THUNDERSTORMS IS GENERALLY
ALONG AND EAST OF HIGHWAY 183. HERE WARM AIR ADVECTION...ISENTROPIC
LIFT ALONG THE 295 KELVIN THETA SURFACE... AND INCREASING 850-650 HPA
FRONTOGENESIS SHOULD INITIATE CONVECTIVE ACTIVITY AFTER 03Z TONIGHT.
ALL THE MESOSCALE MODELS SUGGESTS THIS AS WELL AS THE GFS AND ECMWF.
SEVERE THUNDERSTORMS ARE NOT EXPECTED DUE TO WEAK THERMODYNAMICS AND
WEAK KINEMATICS. CONVECTION SHOULD BE CLEAR OF THE REGION BY DAWN.
A DENSE FOG ADVISORY COULD BE NEEDED FOR TOMORROW MORNING, BUT DO NOT
HAVE ENOUGH CONFIDENCE TO ISSUE ONE THIS EARLY.
TOMORROW:
TOMORROW MORNING WILL BE BREEZY AS THERE WILL BE A TIGHT PRESSURE GRADIENT
ACROSS THE REGION ALONG WITH 45 KT 850 HPA WINDS PARTIALLY MIXING DOWN.
NOT EXPECTING WIND ADVISORY LEVELS AT THIS TIME. OTHER THAN SOME POSSIBLE
LINGERING FOG, TOMORROW WILL BE FAIRLY QUIET WITH CLEARING SKIES. HIGHS
SHOULD BE IN THE 50S DEG F. WINDS SHOULD ABATE AS THE DAY WEARS ON.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 352 AM CST WED FEB 6 2013
THE SHORTWAVE TROUGH MENTIONED IN THE SHORT TERM DISCUSSION WILL
PROGRESS INTO EASTERN KANSAS BY THURSDAY AFTERNOON AND HELP TO
PUSH A COLD FRONT THROUGH SOUTHWEST KANSAS IN THE MORNING. THUS,
HIGH TEMPERATURES SHOULD BE A LITTLE COOLER IN THE 50S. THE LOW
LEVEL MOISTURE THAT WILL HAVE ADVECTED INTO SOUTHERN KANSAS
WEDNESDAY NIGHT WILL BE SHUNTED BACK TO THE GULF COAST BY THURSDAY
AFTERNOON. MEANWHILE, A DEEP UPPER LEVEL TROUGH WILL BE PROGRESSING
SOUTHEASTWARD AND AMPLIFYING ALONG THE WEST COAST. BY FRIDAY, THIS
UPPER LEVEL TROUGH WILL BE LOCATED OVER THE SOUTHERN SECTIONS OF
CALIFORNIA AND NEVADA. A SURFACE TROUGH WILL DEVELOP IN THE LEE OF
THE ROCKIES BY FRIDAY IN RESPONSE TO THE SOUTHWESTERLY MID-LEVEL FLOW
ACROSS THE ROCKIES AHEAD OF THE SYSTEM. BUT THE LOW LEVEL MOISTURE
WILL STILL BE TRAPPED IN SOUTH TEXAS AT THIS TIME. HIGH TEMPERATURES
OUGHT TO REACH THE 50S AGAIN ON FRIDAY.
BY FRIDAY NIGHT AS THE WESTERN TROUGH EDGES INTO UTAH AND ARIZONA, THE
LOW LEVEL FLOW WILL INCREASE FROM THE GULF OF MEXICO INTO THE
SOUTHERN PLAINS. BUT EVEN BY 12Z SATURDAY, THE LOW STRATUS AND GULF
MOISTURE WILL STILL BE WELL TO THE SOUTH. THIS WILL ALLOW FOR RADIATIONAL
COOLING, WITH LOWS IN THE 30S SATURDAY MORNING. ON SATURDAY, THE
UPPER TROUGH WILL PROGRESS EASTWARD, WITH MID LEVEL COOLING
APPROACHING FAR WESTERN KANSAS BY EVENING. STRATUS SHOULD DEVELOP
DURING THE DAY OVER SOUTHWEST KANSAS AS THE LOW LEVEL MOISTURE MOVES
NORTHWARD INTO A FAIRLY COOL AIRMASS. A FEW SHOWERS MAY DEVELOP IN
THE AFTERNOON AS WARM ADVECTION INCREASES IN THE WARM SECTOR. BY
LATE AFTERNOON, SOME CLEARING MAY OCCUR IN FAR WESTERN KANSAS. THIS
MAY ALLOW FOR SOME DAYTIME HEATING AND ENOUGH SURFACE BASED CAPE FOR
THUNDERSTORM DEVELOPMENT ALONG THE DRYLINE. AS ONE WOULD EXPECT THIS TIME
OF YEAR, INSTABILITY WILL BE A MAJOR LIMITING FACTOR DESPITE STRONG
SHEAR. BUT SOME SMALL HAIL CANNOT BE RULED OUT GIVEN THE EXPECTED
COLD 500MB TEMPERATURES (-20C) AND 40-45F SURFACE DEWPOINTS ON THE
HIGHER TERRAIN. ANY STORMS THAT DEVELOP WILL PROGRESS EASTWARD
ACROSS THE REMAINDER OF SOUTHWEST KANSAS SATURDAY NIGHT IN A
WEAKENED STATE. AS THIS SHORTWAVE TROUGH PASSES TO THE NORTHEAST BY
SUNDAY MORNING, THE ASSOCIATED COLD FRONT WILL MOVE THROUGH WESTERN
KANSAS. BUT THIS WILL NOT BE A CANADIAN OR ARCTIC AIRMASS, SO HIGH
TEMPERATURES SHOULD STILL REACH INTO THE UPPER 30S TO LOWER 50S ON
SUNDAY, WITH THE WARMEST READINGS IN SOUTH CENTRAL KANSAS. ANOTHER
UPPER LEVEL TROUGH WILL PROGRESS SOUTHWARD OUT OF CANADA BY
MONDAY, BUT HAVE LIMITED MOISTURE TO WORK WITH IN THE WAKE OF THE
PREVIOUS STRONG SYSTEM. TEMPERATURES SHOULD REMAIN ON THE COOL SIDE
WITH HIGHS IN THE 40S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1203 PM CST WED FEB 6 2013
AN AREA OF LOW MVFR CLOUD COVER ACROSS WESTERN AND CENTRAL KANSAS,
CONTINUES TO ERODE THIS LATE MORNING WITH LITTLE IF ANY REMNANT
CLOUD COVER EXPECTED DURING THE AFTERNOON. HOWEVER, AN AREA OF LOW
PRESSURE OVER EASTERN COLORADO, WILL CONTINUE TO DEEPEN IN ADVANCE
OF A COLD FRONT MOVING THROUGH THE CENTRAL HIGH PLAINS THIS
EVENING TO OVERNIGHT. INITIALLY THIS WILL RESULT IN BRISK SOUTH
WINDS OF 15 TO 20 KNOTS ALONG WITH HIGHER GUSTS THROUGH THE
REMAINDER OF THIS AFTERNOON FOR SOUTHWEST INTO CENTRAL KANSAS.
HOWEVER, AS THE FRONT APPROACHES AND WINDS TURN LIGHT AHEAD OF THE
BOUNDARY, VISIBILITY VALUES ARE LIKELY TO DROP INTO AN IFR RANGE
OF 1 TO 3 MILES MAINLY EAST OF HIGHWAY 283. FURTHER, SOME
RESTRICTIONS DOWN TO A MILE OR LESS WILL BE POSSIBLE NEAR AND EAST
OF THE DODGE CITY TERMINAL DURING THE LATE EVENING TO OVERNIGHT
HOURS. OTHERWISE, A FEW RAIN SHOWERS ASSOCIATED WITH THE COLD
FRONT PASSAGE, MAY CLIP THE HYS AND DDC TERMINALS THIS EVENING TO
EARLY OVERNIGHT BEFORE WINDS TURN TO THE NORTH AND CONDITIONS TURN
DRY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 40 54 27 56 / 10 0 0 0
GCK 36 53 27 56 / 0 0 0 0
EHA 34 51 27 57 / 0 0 0 0
LBL 37 53 27 57 / 0 0 0 0
HYS 39 53 25 55 / 40 0 0 0
P28 48 55 30 56 / 80 50 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...FINCH
AVIATION...AJOHNSON
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1204 PM CST WED FEB 6 2013
...UPDATED AVIATION SECTION...
.SYNOPSIS...
ISSUED AT 911 AM CST WED FEB 6 2013
THE 06.12Z 250 RAOB SYNOPTIC MAP SHOWED ANTICYCLONIC JET FLOW ACROSS
THE CENTRAL US AND EXTENDING INTO PORTIONS OF THE UPPER MIDWEST. A JET
STREAK OF AROUND 125 KT WAS OBSERVED ACROSS WISCONSIN. FAIRLY LIGHT
UPPER LEVEL FLOW WAS OBSERVED ACROSS SOUTHERN KANSAS WITH ONLY 30 KT
AT KDDC. AT 500 HPA, A LARGE CYCLONE WAS LOCATED ACROSS THE NORTHEAST
PACIFIC. A FEW SHORTWAVES WERE NOTED ACROSS THE GREAT BASIN AND TEXAS.
AT 700 HPA, TEMPERATURES WERE AT ZERO CENTIGRADE ACROSS THE TEXAS PANHANDLE
AND SOUTHWEST KANSAS...INDICATING A WAA PATTERN STILL IN PLACE. THE
WARM PLUME AT 850 HPA WAS VERY EVIDENT ACROSS THE CENTRAL PLAINS WITH
VALUES IN THE 8 TO 12 DEG C RANGE. AT THE SFC, A WARM FRONT WAS LOCATED
ALONG WITH THE KANSAS/OKLAHOMA STATE LINE WITH HIGHER DEWPOINTS ADVECTING
IN FROM OKLAHOMA.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 357 AM CST WED FEB 6 2013
AN UPPER LEVEL SHORTWAVE RIDGE WILL MOVE EAST TODAY FROM THE PLAINS
INTO THE MID MISSISSIPPI VALLEY WHILE AN UPPER LEVEL SHORTWAVE
TROUGH MOVES INTO THE INTERMOUNTAIN WEST. THE SHORTWAVE TROUGH WILL
THEN MOVE ACROSS THE CENTRAL PLAINS AFTER MIDNIGHT TONIGHT WITH A
COLD FRONT. AHEAD OF THE COLD FRONT TODAY, A WARM AIRMASS WILL
CONTINUE TO PUSH INTO WESTERN KANSAS WITH 850MB TEMPS RISING TO
AROUND 12 CELSIUS. ALSO LOW LEVEL MOISTURE WILL INCREASE ACROSS MUCH
OF SOUTH CENTRAL KANSAS UNDER SOUTH WINDS AS A TROUGH OF LOW
PRESSURE DEEPENS ACROSS COLORADO INTO NEW MEXICO. SOME LOW STRATUS
AND FOG IS FORECAST BY THE RAP AND HRRR MESOSCALE MODELS EARLY THIS
MORNING FROM LIBERAL TO DODGE CITY AND PRATT BY 9 AM, THEM MOVING
NORTH TO AROUND HAYS BY 11 AM. AS LOW LEVEL MIXING INCREASES IN THE
BOUNDARY LAYER THIS MORNING, THE AREAS OF FOG AND STRATUS SHOULD
BEGIN TO BREAK IN THE MID MORNING TO AROUND NOON. OVER THE WEST
MOSTLY CLEAR SKIES WILL CONTINUE. WINDS WILL BECOME GUSTY BY
AFTERNOON WITH 2O TO 30 MPH EXPECTED. DAYTIME HIGHS SHOULD BE VERY
MILD IN THE WARM SECTOR THIS AFTERNOON WITH HIGHS IN THE MID TO
UPPER 60S TO NEAR 70 FROM WAKEENEY TO DODGE CITY AND MEADE WEST TO
THE COLORADO BORDER, AND SLIGHTLY COOLER EAST IN THE LOW TO MID 60S
WITH A BIT MORE CLOUD COVER EXPECTED.
LOOKING AT CURRENT HRRR MODEL WILL GO AHEAD WITH A DENSE FOR ADVISORY
TILL 11 AM THIS MORNING FROM LIBERAL NORTH TO GARDEN CITY AND EAST
TO LARNED AND ST. JOHN AND SOUTH TO THE OK BORDER. LOW STRATUS AND
FOG RAPIDLY APPROACHING KANSAS BORDER. WITH SOUTH WINDS DO NOT
EXPECT THE FOG TO BE DENSE FOR LONG IN ANY ONE AREA. THE FRONT EDGE
MAY HAVE THE LOWEST VISIBILITIES FOR AN HOUR OR TWO.
LATER TONIGHT, A COLD FRONT WILL SWEEP ACROSS WESTERN KANSAS WITH
SOUTH WINDS SHIFTING NORTH AND INCREASING TO 20 TO 30 MPH MAINLY
AFTER MIDNIGHT. A FEW THUNDERSTORMS MAY ALSO DEVELOP ALONG AND AHEAD
OF THE COLD FRONT FROM NEAR HAYS TO DODGE CITY AND ASHLAND AND EAST
THIS EVENING AND END BY 6 AM THURSDAY MORNING IN THE MEDICINE LODGE
AREA. THIS AREA IN MOST UNSTABLE CAPE OF 300 TO 800 J/KG FORECAST.
WILL CONTINUE TO CARRY THE HIGHEST CHANCES FOR SHOWERS AND
THUNDERSTORMS IN THE SOUTH CENTRAL SECTIONS.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 352 AM CST WED FEB 6 2013
THE SHORTWAVE TROUGH MENTIONED IN THE SHORT TERM DISCUSSION WILL
PROGRESS INTO EASTERN KANSAS BY THURSDAY AFTERNOON AND HELP TO
PUSH A COLD FRONT THROUGH SOUTHWEST KANSAS IN THE MORNING. THUS,
HIGH TEMPERATURES SHOULD BE A LITTLE COOLER IN THE 50S. THE LOW
LEVEL MOISTURE THAT WILL HAVE ADVECTED INTO SOUTHERN KANSAS
WEDNESDAY NIGHT WILL BE SHUNTED BACK TO THE GULF COAST BY THURSDAY
AFTERNOON. MEANWHILE, A DEEP UPPER LEVEL TROUGH WILL BE PROGRESSING
SOUTHEASTWARD AND AMPLIFYING ALONG THE WEST COAST. BY FRIDAY, THIS
UPPER LEVEL TROUGH WILL BE LOCATED OVER THE SOUTHERN SECTIONS OF
CALIFORNIA AND NEVADA. A SURFACE TROUGH WILL DEVELOP IN THE LEE OF
THE ROCKIES BY FRIDAY IN RESPONSE TO THE SOUTHWESTERLY MID-LEVEL FLOW
ACROSS THE ROCKIES AHEAD OF THE SYSTEM. BUT THE LOW LEVEL MOISTURE
WILL STILL BE TRAPPED IN SOUTH TEXAS AT THIS TIME. HIGH TEMPERATURES
OUGHT TO REACH THE 50S AGAIN ON FRIDAY.
BY FRIDAY NIGHT AS THE WESTERN TROUGH EDGES INTO UTAH AND ARIZONA, THE
LOW LEVEL FLOW WILL INCREASE FROM THE GULF OF MEXICO INTO THE
SOUTHERN PLAINS. BUT EVEN BY 12Z SATURDAY, THE LOW STRATUS AND GULF
MOISTURE WILL STILL BE WELL TO THE SOUTH. THIS WILL ALLOW FOR RADIATIONAL
COOLING, WITH LOWS IN THE 30S SATURDAY MORNING. ON SATURDAY, THE
UPPER TROUGH WILL PROGRESS EASTWARD, WITH MID LEVEL COOLING
APPROACHING FAR WESTERN KANSAS BY EVENING. STRATUS SHOULD DEVELOP
DURING THE DAY OVER SOUTHWEST KANSAS AS THE LOW LEVEL MOISTURE MOVES
NORTHWARD INTO A FAIRLY COOL AIRMASS. A FEW SHOWERS MAY DEVELOP IN
THE AFTERNOON AS WARM ADVECTION INCREASES IN THE WARM SECTOR. BY
LATE AFTERNOON, SOME CLEARING MAY OCCUR IN FAR WESTERN KANSAS. THIS
MAY ALLOW FOR SOME DAYTIME HEATING AND ENOUGH SURFACE BASED CAPE FOR
THUNDERSTORM DEVELOPMENT ALONG THE DRYLINE. AS ONE WOULD EXPECT THIS TIME
OF YEAR, INSTABILITY WILL BE A MAJOR LIMITING FACTOR DESPITE STRONG
SHEAR. BUT SOME SMALL HAIL CANNOT BE RULED OUT GIVEN THE EXPECTED
COLD 500MB TEMPERATURES (-20C) AND 40-45F SURFACE DEWPOINTS ON THE
HIGHER TERRAIN. ANY STORMS THAT DEVELOP WILL PROGRESS EASTWARD
ACROSS THE REMAINDER OF SOUTHWEST KANSAS SATURDAY NIGHT IN A
WEAKENED STATE. AS THIS SHORTWAVE TROUGH PASSES TO THE NORTHEAST BY
SUNDAY MORNING, THE ASSOCIATED COLD FRONT WILL MOVE THROUGH WESTERN
KANSAS. BUT THIS WILL NOT BE A CANADIAN OR ARCTIC AIRMASS, SO HIGH
TEMPERATURES SHOULD STILL REACH INTO THE UPPER 30S TO LOWER 50S ON
SUNDAY, WITH THE WARMEST READINGS IN SOUTH CENTRAL KANSAS. ANOTHER
UPPER LEVEL TROUGH WILL PROGRESS SOUTHWARD OUT OF CANADA BY
MONDAY, BUT HAVE LIMITED MOISTURE TO WORK WITH IN THE WAKE OF THE
PREVIOUS STRONG SYSTEM. TEMPERATURES SHOULD REMAIN ON THE COOL SIDE
WITH HIGHS IN THE 40S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1203 PM CST WED FEB 6 2013
AN AREA OF LOW MVFR CLOUD COVER ACROSS WESTERN AND CENTRAL KANSAS,
CONTINUES TO ERODE THIS LATE MORNING WITH LITTLE IF ANY REMNANT
CLOUD COVER EXPECTED DURING THE AFTERNOON. HOWEVER, AN AREA OF LOW
PRESSURE OVER EASTERN COLORADO, WILL CONTINUE TO DEEPEN IN ADVANCE
OF A COLD FRONT MOVING THROUGH THE CENTRAL HIGH PLAINS THIS
EVENING TO OVERNIGHT. INITIALLY THIS WILL RESULT IN BRISK SOUTH
WINDS OF 15 TO 20 KNOTS ALONG WITH HIGHER GUSTS THROUGH THE
REMAINDER OF THIS AFTERNOON FOR SOUTHWEST INTO CENTRAL KANSAS.
HOWEVER, AS THE FRONT APPROACHES AND WINDS TURN LIGHT AHEAD OF THE
BOUNDARY, VISIBILITY VALUES ARE LIKELY TO DROP INTO AN IFR RANGE
OF 1 TO 3 MILES MAINLY EAST OF HIGHWAY 283. FURTHER, SOME
RESTRICTIONS DOWN TO A MILE OR LESS WILL BE POSSIBLE NEAR AND EAST
OF THE DODGE CITY TERMINAL DURING THE LATE EVENING TO OVERNIGHT
HOURS. OTHERWISE, A FEW RAIN SHOWERS ASSOCIATED WITH THE COLD
FRONT PASSAGE, MAY CLIP THE HYS AND DDC TERMINALS THIS EVENING TO
EARLY OVERNIGHT BEFORE WINDS TURN TO THE NORTH AND CONDITIONS TURN
DRY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 61 38 55 28 / 10 20 10 0
GCK 64 36 53 28 / 0 0 0 0
EHA 69 35 54 28 / 0 0 0 0
LBL 68 38 54 28 / 0 0 0 0
HYS 58 37 54 28 / 10 20 0 0
P28 57 44 57 31 / 10 70 50 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...KRUSE
LONG TERM...FINCH
AVIATION...AJOHNSON
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1033 AM MST WED FEB 6 2013
.SHORT TERM...(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 230 AM MST WED FEB 6 2013
TODAY-TONIGHT...CURRENTLY WATCHING A LARGE AREA OF LOW CLOUDS
MOVING TOWARD THE KS/OK BORDER. VISIBILITIES WITHIN THE LOW CLOUDS
ARE AS LOW AS 1/4 MILE. 06Z RUC/NAM HAVE A GOOD HANDLE ON THIS AND
THE AIRMASS NORTHWARD TOWARD OUR FAR EAST/SOUTHEAST COUNTIES BY
15Z THEN SLOWLY EAST THROUGH THE REST OF THE DAY AS A WIND SHIFT
TO THE NORTH MOVES IN FROM THE NORTHWEST. WILL WAIT TIL JUST
BEFORE ZONE ISSUANCE TO SEE WHAT 09Z RUC/07Z HRRR HAVE...MAY NEED
TO BEEF UP THE CLOUDS AND ADD SOME FOG. OTHERWISE SHOULD SEE
PLENTY OF SUN THIS MORNING BEFORE MID AND HIGH CLOUDS MOVE IN FROM
THE WEST AHEAD OF AN UPPER TROUGH THIS AFTERNOON. THESE CLOUDS
WILL BE SLOW TO MOVE OUT TONIGHT FROM NORTHWEST TO SOUTHEAST. WILL
ALSO HAVE TO WATCH LOW CLOUD POTENTIAL OUT EAST TIL THE FRONT AND
INCREASING NORTH WINDS CAN PUSH IT OUT OF THE AREA. HIGHS TODAY
UPPER 50S NORTHWEST TO LOW 60S ELSEWHERE. FAR EAST/SOUTHEAST PARTS
OF THE AREA MAY BE COOLER THEN CURRENTLY EXPECTED IF LOW CLOUDS
LINGER LONGER THEN CURRENTLY EXPECTED. LOWS TONIGHT MID 20S
NORTHWEST TO LOW 30S FAR EAST/SOUTHEAST.
THURSDAY-THURSDAY NIGHT...SUNNY DURING THE DAY AND CLEAR DURING
THE NIGHT WITH UPPER FLOW BACKING TO THE SOUTHWEST AS UPPER LOW
MOVES INTO NORTHERN CALIFORNIA/WESTERN NEVADA BY THE END OF THE
PERIOD. HIGHS IN THE LOW 50S WITH LOWS IN THE 20S.
FRIDAY-FRIDAY NIGHT...AS UPPER LOW SLOWLY MOVES TOWARD THE FOUR
CORNERS BY THE END OF THE PERIOD PRESSURE GRADIENT INCREASES
ACROSS THE AREA WITH SOUTH WINDS OF 20 TO 30 MPH AND GUSTY DURING
THE DAY...A BIT LESS DURING THE NIGHT. SHOULD HAVE A MOSTLY SUNNY
SKY WITH HIGHS WARMING A FEW DEGREES INTO THE MID 50S WHILE LOWS
MILD IN THE 30S.
NO PRECIPITATION IS EXPECTED DURING THE PERIOD.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 1150 PM MST TUE FEB 5 2013
MODELS CONTINUE TO COME INTO BETTER AGREEMENT WITH THE WEEKEND
SYSTEM TO START THIS PERIOD. CUT OFF LOW WILL ORGANIZE OVER
COLORADO ON SATURDAY AND DEEPEN AS IT TRACKS ACROSS THE FORECAST
AREA SATURDAY NIGHT AND SUNDAY. GIVEN THAT TRACK...WILL HAVE TO
PAY CLOSE ATTENTION TO THE DRY SLOT WHICH COULD LIMIT
PRECIPITATION CHANCES ACROSS CENTRAL AND SOUTHERN PARTS OF THE
FORECAST AREA. HOWEVER...ROUGHLY THE NORTHWEST HALF COULD
POTENTIALLY SEE A WINTER STORM BEGINNING SATURDAY NIGHT.
PRECIPITATION WILL LIKELY START AS RAIN...WITH A FEW EMBEDDED
THUNDERSTORMS SATURDAY NIGHT...BEFORE CHANGING OVER TO SNOW FROM
WEST TO EAST LATE SATURDAY NIGHT THROUGH SUNDAY MORNING...ALL SNOW
BY SUNDAY AFTERNOON...WINDING DOWN SUNDAY NIGHT. AS THE SURFACE
LOW DEEPENS...NORTHWEST WINDS WILL INCREASE ON SUNDAY RESULTING IN
AREAS OF BLOWING SNOW AND POTENTIAL FOR BLIZZARD CONDITIONS.
MODELS NOT GENERATING A PARTICULARLY LARGE AMOUNT OF SNOW AT THIS
POINT...GENERALLY LESS THAN 6 INCHES WITH HIGHEST AMOUNTS
NORTHWEST. OTHERWISE...SOME LIGHT SNOW MIGHT LINGER INTO MONDAY
FOLLOWED BY DRY CONDITIONS TUESDAY AND WEDNESDAY WITH GRADUALLY
WARMING TEMPERATURES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1033 AM MST WED FEB 6 2013
VFR CONDITIONS SHOULD CONTINUE AT KGLD AND KMCK FOR THE NEXT 24
HOURS. ONLY MID AND HIGH CLOUDS ARE EXPECTED. ALL OF THE LOW
CLOUDS SHOULD STAY TO THE SOUTHEAST WHERE BETTER MOISTURE IS
AVAILABLE. A COLD FRONT WILL MOVE THROUGH THIS AFTERNOON WITH
NORTH WINDS BEHIND THE FRONT. WINDS WILL THEN BECOME GUSTY LATER
THIS EVENING...15 TO 18 KTS WITH GUSTS AS HIGH AS 27KTS OR SO...AS
A PRESSURE GRADIENT TIGHTENS BETWEEN THE LOW TO THE SOUTHEAST AND
A HIGH BUILDING IN FROM THE NORTHWEST. WINDS WILL WEAKEN TOMORROW
MORNING AS THE SURFACE LOW HEADS EAST.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...99
LONG TERM...024
AVIATION...RRH
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
437 PM CST WED FEB 6 2013
.DISCUSSION...
TWO MAIN CONCERNS THIS FORECAST PACKAGE. THE POTENTIAL FOR
FZRA/FZDZ TONIGHT...THEN WHAT STILL LOOKS TO BE A SIGNIFICANT
WINTER STORM FOR AT LEAST PARTS OF THE AREA SUNDAY INTO MONDAY.
FOR TONIGHT...THE BIG ISSUE WAS WHETHER OR NOT TO ISSUE ANY SORT
OF A WINTER WX OR FRZA ADVY. THIS AFTERNOON...NICE FGEN BAND ROOTED
IN THE H85 TO H7 LAYER HAS ALREADY ALL BUT CLEARED OUR WRN WI
COUNTIES AND SHOULD BE MOSTLY OUT BY 00Z. THIS BAND HAS BROUGHT A
QUICK BURST OF SNOW...WITH 1-2 INCHES COMMON THIS AFTERNOON ACROSS
ERN MN INTO WRN WI. BACK WEST AND SOUTHWEST YOU SEE THE PROBLEM
FOR TONIGHT. IT IS AN INVERTED THROUGH THAT SITS FROM A DIFFUSE
SFC LOW OVER ERN CO...NORTH ACROSS CENTRAL NEB TO THE ABERDEEN
AREA...THEN BACK NW TOWARD BISMARK AND NODAK WHERE IT MERGES WITH
A COLD FRONT. JUST SOUTH OF THE MN RIVER...A FAIRLY STRONG WARM
FRONT HAS COME UP INTO SRN MN....WITH TEMPS IN THE LOWER 40S SOUTH
OF THE BOUNDARY WITH TEENS AND 20S STILL IN PLACE TO THE NORTH. FOR
TONIGHT...MODELS IN FAIRLY GOOD AGREEMENT WITH THE INVERTED TROUGH
WORKING SOUTHEAST ACROSS THE AREA...SETTING UP FROM NEAR KC TO LA
CROSSE BY 12Z.
QUESTION MARKS ARE A PLENTY FOR WHAT WILL HAPPEN TONIGHT...WHICH
IS THE BIGGEST REASON NO HEADLINES WERE ISSUED WITH THIS
PACKAGE...THERE IS JUST NOT IN ENOUGH CONFIDENCE IN WHICH OF THE
SCENARIOS TO FOLLOW WILL PLAY OUT THIS EVENING TO BE ABLE TO PLACE
ANY AREA WITHIN ADVY.
FIRST...WHAT SHOULD BE NOTED AS THAT FORECAST SOUNDINGS ACROSS THE
ENTIRE AREA SHOW WE ARE DONE WITH GENERATING ICE CRYSTALS FOR THE
NIGHT...LEAVING US WITH LIQUID AS THE P-TYPE FROM HERE ON OUT FOR
TONIGHT. FORECAST SOUNDINGS CERTAINLY ARE SUPPORTIVE OF DZ
GENERATION...WITH SOUNDINGS BECOMING NEARLY SATURATED FROM THE
SFC UP THROUGH AROUND 2K FT SW AND 4K FT NORTHEAST. HOWEVER...TO
GET DZ...YOU LIKE TO SEE SOUTH OR SOUTHEAST LOW LEVEL WINDS WITH A
DECENT PUSH OF WAA AND A LITTLE MOISTURE TRANSPORT TO HELP THINGS
ALONG. THE PROBLEM WITH TONIGHT THROUGH...IS AS THIS INVERTED
TROUGH MOVES INTO MN...THE WINDS ACROSS THE AREA TURN MORE EAST TO
NORTHEAST...NOT AS CONDUCIVE TO DZ PRODUCTION. IN ADDITION...
MOISTURE TRANSPORT IN 925-850 MB LAYER IS DIRECTED MORE FROM
CENTRAL IA INTO FAR SE MN AND CENTRAL WI TONIGHT...LARGELY SOUTH
AND EAST OF THE MPX AREA. FURTHER COMPLICATING THINGS IS THE FACT
THAT TEMPERATURES HAVE WARMED INTO THE 40S ALONG THE I-90 CORRIDOR
THIS AFTERNOON...AND WITH THAT AREA LARGELY SNOW-FREE...IS
QUESTIONABLE IF TEMPS DOWN THERE EVEN FALL BELOW FREEZING THIS
EVENING...HENCE WANTING TO AVOID ANY FZRA ADVYS IN SC MN.
WHAT DOES THIS ALL MEAN? BESIDE THE FACT THAT IT IS A TRICKY
FORECAST FOR TONIGHT...IT MEANS THE SCENARIO I AM CURRENTLY MOST
CONFIDENCE IN OCCURRING IS A NIGHT FULL OF LOW STRATUS AND
FOG...WITH LITTLE IN THE WAY OF PRECIP/DZ...SO OPTED FOR NO
HEADLINES...THOUGH THE EVENING SHIFT WILL HAVE TO MONITOR TRENDS
CLOSELY THIS EVENING.
INTERESTINGLY...AS WE HEAD THROUGH THE DAY THURSDAY...EXPECT
CHANCES FOR SNOW TO CREEP BACK IN ACROSS ERN AREAS AS DEEPER
MOISTURE RETURNS. THE CULPRIT FOR THIS IS A RATHER POTENT SHORT
WAVE MODELS SHOW TRACKING ACROSS SRN MN DURING THE MORNING INTO
THE AFTERNOON. LIFT AND DEEPER MOISTURE ASSOCIATED WITH THIS
FEATURE SHOULD INTERACT WITH LOW LEVEL MOISTURE ALREADY IN PLACE
TO LEAD TO ONE LAST BURST OF SNOW ACROSS FAR ERN AREAS...WITH
ANOTHER INCH OF SNOW NOT OUT OF THE QUESTION.
THURSDAY NIGHT THROUGH SATURDAY WILL BE DOMINATED BY THE ARRIVAL
OF UPPER RIDGING...WHICH WILL PROMOTE A DRY PERIOD. SFC HIGH COULD
LEAD TO A CHILLY START TO THE DAY FRIDAY...BUT BY FRIDAY
AFTERNOON...SAID HIGH PUSHES INTO THE GREAT LAKES...WITH STRONG
SRLY FLOW AND WAA SETTING UP ACROSS THE AREA FOR FRIDAY THROUGH
SATURDAY.
FOR SATURDAY NIGHT THROUGH MONDAY...IT IS OBVIOUS FROM PHONE CALLS
RECEIVED IN THE OFFICE TODAY THAT THE RABBIT HAS LONG SINCE LEFT
THE HAT WITH THE POTENTIAL FOR A SIGNIFICANT WINTER STORM IN THIS
TIME PERIOD. CONTINUE TO SEE GOOD AGREEMENT AMONG 12Z MODELS WITH
THEIR HANDLING OF THE SYSTEM...WITH ONLY MINOR TIMING/PLACEMENT
DIFFERENCES NOTED. OF COURSE WITH THE DEGREE OF WARM AIR THIS
SYSTEM BRINGS UP...THESE PLACEMENT DIFFERENCES HAVE HUGE
IMPLICATIONS ON WHAT TYPE OF PRECIPITATION IS SEEN. AFTER PUTTING
TOGETHER THIS PACKAGE OF GRIDS...IT BECAME OBVIOUS THAT THIS
CURRENT FORECAST FAVORS MORE THE GFS SOLUTION...WHICH HAS THE
SNOW/MIX LINE THE FARTHEST NW. BASED ON 925 MB TEMPS AND WHERE THE
0C ISOTHERM IS TAKEN. THE 12Z GFS WOULD HAVE THE SNOW LINE
SOMEWHERE NEAR A REDWOOD FALLS/ST. CLOUD/CAMBRIDGE LINE. THE ECMWF
IS MORE OF A ST. JAME/RED WING/EAU CLAIRE LINE...WHILE THE GEM/FIM
WOULD BE MORE OF AN ALBERT LEA/ROCHESTER/EAU CLAIRE LINE. IT
SHOULD BE NOTED THOUGH...THAT DUE TO THE LATENESS OF THIS AFD
COMING OUT...AM ABLE TO SEE THAT THE 18Z VERSION OF THE GFS HAS
TRENDED TOWARD THE FIM. ANOTHER FACTOR ALL MEDIUM RANGE GUIDANCE
INDICATES THAT WILL NEED TO BE WATCHED IS THE PROGRESSION OF
RATHER PRONOUNCED DRY SLOT AT H7. THIS LOOKS TO HAVE IMPACTS ON
THE AMOUNT OF QPF SEEN...ESPECIALLY ACROSS THE ERN HALF OF THE
AREA. NEEDLESS TO SAY...FULLY EXPECT MANY CHANGES TO THE FORECAST
IN THE DAYS TO COME WITH THIS SYSTEM...THOUGH RIGHT NOW...THE
HIGHEST PROBABILITY FOR SIGNIFICANT SNOWS /GREATER THAN 10 INCHES/
WITH BLIZZARD CONDITIONS STILL EXISTS ALONG AND WEST OF ABOUT A
REDWOOD FALL...TO ST. CLOUD...TO MILLE LACS LAKE LINE.
BEHIND THIS SYSTEM...LOOKS COOLER AND DRY INTO THE MIDDLE OF NEXT
WEEK...WITH TEMPERATURES SLIGHTLY BELOW NORMAL.
&&
.AVIATION.../00Z TAF ISSUANCE/
SNOW HAS CLEARED THE MN TAF SITES AND WILL CLEAR KRNH AND KEAU BY
00Z. IN FACT VISIBILITIES WILL IMPROVE DRAMATICALLY BY 20Z AT THOSE
TWO SITES. ELSEWHERE CEILING AND VISIBILITIES IMPROVED
DRAMATICALLY ONCE THE SNOW ENDED. FOR THE REMAINDER OF THE
AFTERNOON CAN EXPECT MID LEVEL CLOUDS BEFORE DEGRADING THIS
EVENING. IN FACT EXPECT MVFR TO IFR AT ALL LOCATIONS SHORTLY AFTER
00Z. LIFR IS NOT OUT OF THE QUESTION BY 03Z AS WELL AS PATCHY
FREEZING DRIZZLE. DO NOT EXPECT WIDESPREAD FREEZING DRIZZLE AS
LIMITED AMOUNT OF LIFT IN THE LOW LEVELS AS INDICATED BY TIME HEIGHT
SECTIONS AND ALSO A LACK OF MOISTURE TRANSPORT...TO BE EXPECTED
WITH A NORTHERLY WIND. BY 12Z THURSDAY WINDS WILL INCREASE TO 8KTS
FROM THE NNE. ANY LIFR CONDITIONS SHOULD BE GONE AT THAT TIME AND
COULD SEE SELECT SITES BECOME MVFR...NOT GOOD CONFIDENCE THOUGH.
ANY PATCHY FREEZING DRIZZLE WOULD BE DONE AS WELL. A FEW FLURRIES
ARE NOT OUT OF THE QUESTION AND BUFKIT RAP/NAM INDICATES A RETURN
TO SNOW AFTER SUNRISE. HRRR WOULD LIKE TO BRING VISIBILITIES DOWN
TO BLO 3SM TONIGHT AND LOWER THAN 1SM IN SW MN BUT BELIEVE THAT
TO BE OVERDONE.
KMSP...
HIGH CONFIDENCE IN MVFR/IFR CONDITIONS FOR THE EVENING
COMMUTE. THE THREAT FOR FREEZING DRIZZLE BEGINS AFTER 00Z. THE
TIMING IN THE CURRENT TAF IS OUR BEST GUESS FOR THE START OF
DRIZZLE...BUT IT MAY IN FACT COME A BIT EARLIER THAN WHAT`S
CURRENTLY IN THE FORECAST. EXPECT IT TO BE PATCHY AND HOPE THE
CEILINGS AND VISIBILITIES ADHERE TO THE TAF.
/OUTLOOK FOR KMSP/
THU NIGHT...MVFR CIGS/VSBYS WITH -SN /FLURRIES/ POSSIBLE. WIND NW 5-10 KTS.
FRI...VFR. WIND SE 5-10 KTS.
SAT...VFR. WIND S 5-10 KTS.
SUN...MVFR/IFR WITH RA AND SN POSSIBLE. WINDS SE 10-20 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
MPG/DRL
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1258 PM CST WED FEB 6 2013
.UPDATE...
UPDATED FOR 18Z AVIATION DISCUSSION BELOW...
.DISCUSSION...
ANOTHER WEAK CLIPPER WILL SPREAD LIGHT SNOW ACROSS THE REGION
TODAY. LIGHT SNOW AND FREEZING DRIZZLE COULD LINGER INTO
THURSDAY...ESPECIALLY ACROSS WESTERN WISCONSIN AND EASTERN
MINNESOTA AS THE SYSTEM STRENGTHENS OVER THE GREAT LAKES. WARM
WEATHER WILL FOLLOW FOR THE END OF THE WEEK AS SOUTHWEST FLOW
DEVELOPS AHEAD OF THE NEXT STORM SYSTEM EXPECTED TO EMERGE OUT OF
THE DESERT SOUTHWEST. THIS SYSTEM WILL HAVE MUCH MORE MOISTURE TO
WORK WITH AND COULD BRING SIGNIFICANT SNOWFALL OVER THE UPPER
MIDWEST FOR THE WEEKEND.
TODAY THROUGH THURSDAY...SURFACE TROUGH CONTINUES TO MAKE SLOW
PROGRESS OUT OF THE ROCKIES INTO THE NORTHERN PLAINS THIS
MORNING. LARGE AREA OF 850 MB WARM AIR ADVECTION STRETCHING FROM
WESTERN MINNESOTA WESTWARD BACK INTO THE DAKOTAS. THE UPPER
MISSISSIPPI RADAR MOSAIC SHOWS PLENTY OF RETURNS IN THE DAKOTAS
EARLY THIS MORNING...BUT THERE IS LITTLE GROUND TRUTH UP TO THIS
POINT. WARM ADVECTION SUGGESTS WE HAVE CROSS ISOTHERM FLOW...BUT
IT SAYS NOTHING ABOUT THE TRANSFER OF MOISTURE OR FRONTOGENETICAL
PROCESSES...BOTH OF WHICH ARE SOMEWHAT LACKING SO FAR THIS
MORNING. FOR EXAMPLE...THE PWAT OFF THE 06.00Z KABR AND KLBF
SOUNDINGS WERE 0.27" AND 0.34" RESPECTIVELY AND KLBF IS MUCH
WARMER. THEREFORE...THE MOISTURE ADVECTION WILL TAKE SOME TIME TO
GET GOING AND SHOULD BECOME BETTER ENHANCED AS THE INVERTED TROUGH
HEADS EAST INTO SOUTHERN MINNESOTA THIS EVENING. THE LOWER
CONDENSATION PRESSURE DEFICITS OFF THE 290K ISENTROPIC SURFACE
FROM THE NAM AND GFS SEEM TO HIGHLIGHT WHATS CURRENTLY SHOWING UP
ON RADAR...WHICH REMAINS SLIGHTLY ELEVATED. SO...TRIED TO TREND
THE TIMING AND LOCATION OF THE LIKELY POPS CLOSER TO WHERE
SATURATION OCCURS ON 285K. THIS ALSO FOLLOWS THE MODEL CONSENSUS
QPF A LITTLE BETTER. AT ANY RATE...LIGHT SNOW SHOULD BREAK OUT IN
WESTERN AND CENTRAL MN BY THIS AFTERNOON...AND SLIDE EAST-
SOUTHEAST WITH TIME. WARMER TEMPS WILL KEEP RATIOS HIGHER
/ACTUALLY CLOSER TO CLIMATOLOGY/ FROM THE CLIPPERS WE`VE SEEN THE
LAST FEW DAYS. THE HIGHEST TOTALS IN THE FORECAST AREA WILL LIKELY
OCCUR IN WEST CENTRAL WI WHERE A SOLID COUPLE INCHES ARE POSSIBLE.
AS THE SNOW BEGINS TO TAPER OFF...AND THE INVERTED TROUGH STILL
KEEPING LOW LEVEL MOISTURE IN PLACE...FREEZING DRIZZLE SEEMS
LIKELY THIS EVENING OVER MOST OF THE FORECAST AREA TONIGHT. WE
WILL CONTINUE TO MONITOR THE SITUATION AS A FREEZING
RAIN/DRIZZLE ADVISORY MAY BE NEEDED. FORECAST SOUNDINGS SHOW LOW
LEVEL MOISTURE AND THE POTENTIAL FOR SOME FREEZING DRIZZLE
LASTING THROUGH THURSDAY MORNING. THE SREF 05.21 PROBABILITIES
SHOW FREEZING RAIN POTENTIAL ACROSS THE ENTIRE CWA...WITH HIGHEST
PROBABILITIES ALONG THE I-90 CORRIDOR. NORTHWEST WINDS WILL BRING
DRIER AIR ACROSS THE REGION BY THURSDAY AFTERNOON.
FRIDAY THROUGH WEDNESDAY...A SIGNIFICANT CHANGE IN THE WEATHER
PATTERN IS ON TRACK FOR LATER THIS WEEK AS AN UPPER LEVEL WAVE WITH
SEVERAL EMBEDDED VORTICITY MAXIMA CURRENTLY LOCATED IN THE GULF OF
ALASKA WILL DIVE SOUTHEAST ALONG THE CALIFORNIA COAST AND AFFECT THE
UPPER MIDWEST BY EARLY NEXT WEEK. THIS SYSTEM WILL BE DIAGNOSED FROM
A POTENTIAL VORTICITY PERSPECTIVE TO TRY TO GAIN SOME INSIGHT ON HOW
THE ATMOSPHERE IS EXPECTED TO EVOLVE. AN EARLY MORNING ANALYSIS VIA
THE GFS90 06.00 CROSS SECTION SHOWING ISENTROPES...POTENTIAL
VORTICITY...AND WINDSPEED ORIENTED ALONG THE 130W MERIDIAN FROM 60N
TO 20S IDENTIFIED 2 DISTINCT JETS AS SEEN BY THE TROPOPAUSE
UNDULATIONS AT ROUGHLY 30N AND 55.. THE NORTHERN JET WAS ORIENTED
ALONG THE US/CANADA BORDER. THIS JET WAS LOCATED ATOP THE MOST
WELL-DEFINED LOW LEVEL TEMPERATURE GRADIENT...WHILE THE SOUTHERNMOST
JET WAS DRIVEN PRIMARILY BY THE UPPER LEVEL FRONT LOCATED WITHIN THE
H500 TO H150 LAYER. AS TIME PROGRESSES OVER THE NEXT COUPLE OF
DAYS...THE AFOREMENTIONED WAVE IN THE GULF OF ALASKA WILL BECOME
DETACHED FROM THE NORTHERN STREAM AS IT CRAWLS DOWN THE WEST COAST.
UNDER NORMAL CIRCUMSTANCES THIS IS WHERE OLD PACIFIC STORMS GO TO
DIE AS THE LATENT HEAT RELEASE AT MID LEVELS GRADUALLY ERODES THE
PV...ALONG WITH THE DECREASED CORIOLIS FORCE AT LOWER LATITUDES.
HOWEVER...THIS WILL NOT BE THE CASE WITH THIS STORM. BY TRANSLATING
THE CROSS SECTION EASTWARD TO THE 120W MERIDIAN...ONE IS ABLE TO
CAPTURE THE WEAKENING PV ANOMALY AS IT SLIDES SOUTHWARD OVER
CALIFORNIA. IT IS HERE THAT THE UPPER LEVEL WAVE MERGES WITH THE
SUBTROPICAL JET...AS SEEN BY THE COUPLED JET IN THE CROSS SECTION.
ONCE THIS OCCURS...THE CYCLONIC SHEAR ON THE POLEWARD SIDE OF THE
SUBTROPICAL JET WILL INTERACT WITH THE OCCLUDED STORM CAUSING IT TO
STRENGTHEN AS IT MOVES ACROSS THE 4-CORNERS REGION ON SATURDAY AND
HEADS TOWARDS THE UPPER MIDWEST EARLY NEXT WEEK. BOTH THE GFS AND
ECMWF 06.00 ARE IN REMARKABLE AGREEMENT WITH TIMING AND PLACEMENT OF
THE SURFACE LOW...AND SHOW THE UPPER WAVE TAKING ON A NEGATIVE TILT
AS IT APPROACHES THE UPPER MISSISSIPPI RIVER VALLEY. THE GFS HAS A
MORE ROBUST TEMPERATURE GRADIENT AND THEREFORE DEEPENS THE LOW MORE
QUICKLY THAN THE ECMWF. THERMAL PROFILES SHOW THE POTENTIAL FOR SOME
MIXED PRECIP ACROSS THE SOUTHEASTERN CWA...SO HAVE
SNOW/RAIN/FREEZING RAIN WORDING IN THE GRIDS. THIS STORM WILL TAP
INTO THE GULF MOISTURE AND PWATS WILL EXCEED 2 STANDARD DEVIATIONS
FROM NORMAL AS THEY APPROACH NEARLY 3/4 OF AN INCH. LONG STORY
SHORT...THIS STORM HAS THE POTENTIAL TO BRING A SIGNIFICANT SNOW
STORM ACROSS THE REGION LATE SATURDAY THROUGH SUNDAY...WITH THE BEST
CHANCE FOR ACCUMULATING SNOW AS OF NOW EXPECTED TO BE ALONG A LINE
FROM NORTH CENTRAL NEBRASKA...THROUGH WESTERN AND NORTHERN
MINNESOTA. TEMPERATURES WILL BE NEAR OR SLIGHTLY ABOVE NORMAL IN THE
FEW DAYS PRECEDING THIS STORM...AND THEN COOL OFF TOWARDS THE
MIDDLE OF NEXT WEEK.
&&
.AVIATION.../00Z TAF ISSUANCE/
SNOW HAS CLEARED THE MN TAF SITES AND WILL CLEAR KRNH AND KEAU BY
00Z. IN FACT VISIBILITIES WILL IMPROVE DRAMATICALLY BY 20Z AT THOSE
TWO SITES. ELSEWHERE CEILING AND VISIBILITIES IMPROVED
DRAMATICALLY ONCE THE SNOW ENDED. FOR THE REMAINDER OF THE
AFTERNOON CAN EXPECT MID LEVEL CLOUDS BEFORE DEGRADING THIS
EVENING. IN FACT EXPECT MVFR TO IFR AT ALL LOCATIONS SHORTLY AFTER
00Z. LIFR IS NOT OUT OF THE QUESTION BY 03Z AS WELL AS PATCHY
FREEZING DRIZZLE. DO NOT EXPECT WIDESPREAD FREEZING DRIZZLE AS
LIMITED AMOUNT OF LIFT IN THE LOW LEVELS AS INDICATED BY TIME HEIGHT
SECTIONS AND ALSO A LACK OF MOISTURE TRANSPORT...TO BE EXPECTED
WITH A NORTHERLY WIND. BY 12Z THURSDAY WINDS WILL INCREASE TO 8KTS
FROM THE NNE. ANY LIFR CONDITIONS SHOULD BE GONE AT THAT TIME AND
COULD SEE SELECT SITES BECOME MVFR...NOT GOOD CONFIDENCE THOUGH.
ANY PATCHY FREEZING DRIZZLE WOULD BE DONE AS WELL. A FEW FLURRIES
ARE NOT OUT OF THE QUESTION AND BUFKIT RAP/NAM INDICATES A RETURN
TO SNOW AFTER SUNRISE. HRRR WOULD LIKE TO BRING VISIBILITIES DOWN
TO BLO 3SM TONIGHT AND LOWER THAN 1SM IN SW MN BUT BELIEVE THAT
TO BE OVERDONE.
KMSP...
HIGH CONFIDENCE IN MVFR/IFR CONDITIONS FOR THE EVENING
COMMUTE. THE THREAT FOR FREEZING DRIZZLE BEGINS AFTER 00Z. THE
TIMING IN THE CURRENT TAF IS OUR BEST GUESS FOR THE START OF
DRIZZLE...BUT IT MAY IN FACT COME A BIT EARLIER THAN WHAT`S
CURRENTLY IN THE FORECAST. EXPECT IT TO BE PATCHY AND HOPE THE
CEILINGS AND VISIBILITIES ADHERE TO THE TAF.
/OUTLOOK FOR KMSP/
THU NIGHT...MVFR CIGS/VSBYS WITH -SN /FLURRIES/ POSSIBLE. WIND NW 5-10 KTS.
FRI...VFR. WIND SE 5-10 KTS.
SAT...VFR. WIND S 5-10 KTS.
SUN...MVFR/IFR WITH RA AND SN POSSIBLE. WINDS SE 10-20 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JRB/DRL
AREA FORECAST DISCUSSION
NWS BILLINGS MT
320 PM MST WED FEB 6 2013
.SHORT TERM...VALID FOR THU AND FRI...
A RELATIVELY QUIET PERIOD IS IN STORE THE NEXT FEW DAYS...AT LEAST
UNTIL SOME UPSLOPE SNOWFALL POTENTIAL SHOWS UP IN THE FOOTHILLS BY
FRI NIGHT.
TONIGHT...THE 18 UTC HRRR TAKES THE SHALLOW CONVECTION OBSERVED IN
SOUTH CENTRAL MT AS OF MID AFTERNOON EASTWARD INTO SOUTHEASTERN MT
DURING THE EVENING. WE WILL ADVERTISE SOME LOW POPS THROUGH 03 UTC
FOR PARTS OF THE AREA IN RESPECT TO THIS...THOUGH CONVECTION COULD
VERY WELL DIMINISH CLOSER TO 00 UTC AS SURFACE COOLING TAKES HOLD.
THE REST OF THE NIGHT WILL BE QUIET WITH RISING HEIGHTS ALOFT.
THU...A SHORT WAVE RIDGE AT 500 HPA WILL CROSS THE AREA DOWNSTREAM
OF VIGOROUS HEIGHT FALLS WITH A PACIFIC TROUGH THAT DIVES INTO THE
WEST COAST DURING THE DAY. MODEST WARM AIR ADVECTION OCCURS ALOFT.
HOWEVER...LOW-LEVEL FLOW WILL BE RELATIVELY WEAK...ESPECIALLY OVER
SOUTHEASTERN MT WHERE SURFACE WINDS WILL BE SOUTHEASTERLY AHEAD OF
A LEE SURFACE TROUGH. MIXING WILL BE LIMITED. WE THEREFORE DECIDED
TO LEAN ON THE MULTI-MODEL CONSENSUS FOR HIGHS...ASSUMING THAT THE
GUIDANCE WILL NOT UNDERESTIMATE HIGHS TOO MUCH IN THIS CASE. THERE
IS A GOOD SIGNAL FOR DRAINAGE WINDS OUT OF THE BIG HORN BASIN INTO
THE BILLINGS AREA...BUT A SIMILAR SCENARIO ON TUE DID NOT HOLD THE
HIGHS BACK TOO MUCH...SO IT MAY NOT BE A BIG FACTOR ON THU EITHER.
FRI INTO FRI NIGHT...THE PACIFIC TROUGH WILL HAVE FINISHED A SPLIT
AND THE DYNAMIC...SOUTHERN-STREAM PORTION OF THE WAVE IS PROJECTED
TO MOVE ACROSS THE CENTRAL ROCKIES. WE WILL REMAIN ON THE NORTHERN
PERIPHERY OF THIS SYSTEM...THOUGH SOME MODEST FORCING DOES SHOW UP
ON 500-300 HPA Q-VECTOR SIMULATIONS FROM THE 12 UTC GFS. LOW-LEVEL
FLOW WILL BECOME UPSLOPE...AND ONCE THE OROGRAPHIC FORCING DEEPENS
TO ABOUT 700 HPA BY FRI NIGHT...SOME SNOW WILL PROBABLY DEVELOP IN
THE FOOTHILLS. THE 12 UTC NAM SOLUTION IS A WET OUTLIER BECAUSE IT
IS FURTHER NORTH WITH THE DYNAMIC WAVE...SO IT WAS ESSENTIALLY SET
ASIDE FOR NOW. EVEN SO...THE 12 UTC GFS AND ECMWF BOTH SUPPORT THE
POTENTIAL FOR AT LEAST SOME LIGHT SNOW...ESPECIALLY NEAR SHERIDAN.
WE THUS INCREASED POPS INTO THE 50 PERCENT RANGE FRI NIGHT FOR THE
FOOTHILLS. NOTE THAT THE 12 UTC CIPS ANALOGS SUGGEST MEAN SNOWFALL
OF 2 TO 4 INCHES...WHICH ALSO CONFIRMS SOME SNOW POTENTIAL TIED TO
THIS ADMITTEDLY SUBTLE EVENT. SCHULTZ
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
ACTIVE EXTENDED PERIOD WILL BEGIN WITH A CUTOFF LOW PUSHING
THROUGH THE FOUR-CORNERS REGION INTO THE UPPER MIDWEST OVER THE
WEEKEND. A NORTHERN STREAM SHORTWAVE AND COLD FRONT WILL PUSH INTO
THE AREA ON SUN AS WELL. UPSLOPE FLOW AND ISENTROPIC LIFT AROUND
THE UPPER LOW TO THE S WILL BRING A CHANCE OF PRECIPITATION TO
AREAS OVER AND NEAR THE BEARTOOTHS/ABSAROKAS TO BIG HORN AND
SHERIDAN COUNTIES SAT AND SAT NIGHT. HAVE INCREASED POPS FOR THESE
PERIODS. TEMPERATURES IN THE 30S ON SAT WERE IN GOOD SHAPE. THE
COLD FRONT WILL PUSH INTO THE AREA ON SUN...AND WRAP-AROUND
MOISTURE WILL LINGER BEHIND THE LOW MOVING INTO THE UPPER MIDWEST.
THESE FEATURES SUPPORTED THE CHANCE POPS IN THE FORECAST. DID
LOWER TEMPERATURES ON SUN WITH THE FRONT MOVING THROUGH THE AREA.
MOISTURE WILL BE PULLING S OUT OF THE AREA SUN NIGHT WITH
CONTINUED LOW PRECIPITATION CHANCES ACROSS SE AND SOUTHERN
PORTIONS OF THE REGION. LOWERED MINS DUE TO 850 MB TEMPERATURES
CLOSE TO -10 DEGREES C.
SHORTWAVE RIDGE WILL NUDGE E OVER THE REGION ON MON HELPING TO DRY
OUT THE AIRMASS. LOWERED TEMPERATURES A BIT. THE RIDGING WILL
PERSIST INTO TUE. THE ECMWF WAS MUCH WARMER THAN GFS ON TUE...SO
MADE NO TEMPERATURE ADJUSTMENTS. THE GFS AND ECMWF SHOWED NW FLOW
OVER THE AREA ON WED...BUT THE ECMWF HAD A WETTER SOLUTION WITH A
SHORTWAVE MOVING THROUGH THE REGION. LEFT POPS ALONE FOR NOW WITH
NO CHANGES TO TEMPERATURES. ARTHUR
&&
.AVIATION...
GUSTY W TO NW SURFACE WINDS WILL DIMINISH AROUND SUNSET. VFR WILL
PREVAIL TONIGHT THROUGH THU. THERE WILL BE AREAS OF MOUNTAIN
OBSCURATION THROUGH THIS EVENING DUE TO SHOWERS. ARTHUR
&&
.PRELIMINARY POINT TEMP/POPS...
THU FRI SAT SUN MON TUE WED
-----------------------------------------------------------
BIL 026/046 026/042 022/038 024/033 017/034 025/043 025/043
20/B 01/B 11/B 23/J 11/B 11/B 11/B
LVM 025/046 024/039 019/035 021/028 013/032 020/041 026/041
10/N 02/W 22/J 32/J 21/B 11/N 11/B
HDN 022/046 022/040 020/037 022/031 014/032 022/042 022/042
20/B 00/B 12/J 23/J 21/B 11/B 11/B
MLS 022/043 021/040 019/033 021/030 014/029 021/039 022/039
20/B 00/B 10/B 23/J 21/B 11/B 11/B
4BQ 021/045 023/042 021/034 020/030 015/029 020/039 021/039
10/U 00/B 11/B 13/J 21/B 11/U 11/B
BHK 020/040 019/040 016/031 017/027 011/024 016/034 019/034
10/U 00/B 10/B 23/J 20/B 01/B 11/B
SHR 017/043 022/039 018/034 016/028 011/029 018/039 018/039
20/U 00/B 53/J 33/J 21/B 11/B 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
441 PM EST WED FEB 6 2013
.SYNOPSIS...
ALTHOUGH THE CENTER OF HIGH PRESSURE WILL SLIDE EAST OF THE REGION
TONIGHT...IT WILL CONTROL THE REGIONS WEATHER INTO TOMORROW. A
COLD FRONT WILL MOVE ACROSS THE REGION THURSDAY NIGHT AND EARLY
FRIDAY...BRINGING AN AREA RAIN...BEFORE COLDER AIR CHANGES IT TO
SOME SNOW. HIGH PRESSURE WILL MOVE IN AGAIN FOR FRIDAY NIGHT AND
SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AREA OF STUBBORN CLOUDS ACROSS THE SRN PORTION OF THE FA CONTINUES
TO SLOWLY ERODE FROM THE N AND S. LATEST RUC MODEL RUN SUGGESTS THAT
THESE CLOUDS WILL CONTINUE TO DISSIPATE AND SHOULD BE GONE SHORTLY
AFTER MIDNIGHT. MEANWHILE MIDDLE TO HIGH CLOUDS WILL WORK ACROSS
THE REGION TONIGHT...BRINGING PARTLY CLOUDY SKIES TO THE REGION.
THE COMBINATION OF THE LOW CLOUDS EARLY AND THE HIGHER CLOUDS
LATER IN THE NIGHT WILL HELP KEEP THE TEMPERATURES UP A LITTLE.
WENT CLOSE TO MOS GUIDANCE IN THE S...BUT A LITTLE COOLER IN THE
N...WITH THE CLOUD COVER AND ALREADY CLEAR SKIES. LOWS SHOULD
RANGE FROM THE UPPER 20S IN THE S TO UPPER TEENS IN THE EXTREME
RURAL NE.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
FA WILL BE UNDER WAA ON THURSDAY. MODELS HAVE SLOWED THE EWD
PROGRESSION OF THE DEVELOPING SFC AND CDFNT. THUS HAVE DRIED OUT
THURSDAY. GFS MOS REMAINS THE COLDEST. THIS COULD BE IN RESPONSE
TO THE SNOW COVER ACROSS THE N. WENT WITH A BLEND OF THE
GUIDANCE...THIS PUTS VALUES IN THE N A FEW DEGREES WARMER THAN
THE COLD GFS MOS IN THE NW...BUT CLOSE ELSEWHERE.
THE NAM IS THE OUTLIER WITH THE SYSTEM FOR THURSDAY NIGHT/FRIDAY. IT
IS QUICKER WITH THE SFC FEATURE AND WEAKER WITH THE TRAILING H5
S/W. THE GFS/ECMWF AND CMC ALL SWING THE STRONGER S/W IN AFTER
12Z FRI...WHICH SHOULD PROVIDE LIFT FOR LINGERING SHOWERS...SNOW
IN THE N AND A RA/SN MIX IN THE S. SO KEPT THE 100 POPS THURSDAY
NIGHT WITH FRONT IN THE WAA AND LINGERED PCPN MAINLY FRI MORNING.
WENT WITH A GFS/ECMWF BLEND ON THE THICKNESSES FOR THE CHANGE OVER
TO SNOW...SO WENT TO SNOW QUICKLY FRIDAY MORNING IN THE NW...BUT
WAITED UNTIL AFTERNOON FOR THE SRN LOCATIONS. HIGH PRESSURE BUILDS
BACK IN FOR FRIDAY NIGHT.
HIGHS IN THE NW COULD BE EARLY FRIDAY IN THE NW...WITH MORE SRN
LOCATIONS MAYBE SEEING HIGHS AROUND NOON INSTEAD OF LATE
AFTERNOON. WITH GRADUALLY CLEARING SKIES FRIDAY NIGHT
TEMPERATURES WILL FALL INTO THE UPPER TEENS TO LOWER 20S FRIDAY
NIGHT.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
SATURDAY STARTS OUT DRY WITH HIGH PRESSURE AT THE SURFACE AND AN
INCOMING UPPER LEVEL RIDGE. THE RIDGE CROSSES THE OHIO VALLEY
OVERNIGHT AND THERE IS A MARKED INCREASE IN MOISTURE ON THE BACK
SIDE OF IT BY DAYBREAK SUNDAY. HAVE PULLED BACK ON THE SLIGHT CHANCE
OF SHOWERS WORKING IN EARLY IN THE DAY AS MODELS ARE BARELY SHOWING
THE ONSET OF RAIN IN SOUTHWEST INDIANA BY 12Z AND THE SURFACE TEMPS
ARE QUITE COLD. PULLING THE CHANCE FOR PRECIP OUT AT THIS TIME
REMOVES THE POTENTIAL FOR THE RAIN TO NEED A FREEZING QUALIFIER IN
THE FORECAST.
KEPT A LIKELY CHANCE OF RAIN WITH THE FRONTAL PASSAGE ON SUNDAY.
LEFTOVER COLD FRONT FROM SUNDAY NIGHT/MONDAY SYSTEM OVER THE TN
VALLEY IS NOW BEING PROGGED TO REMAIN SOUTH OF THE APPALACHIANS WITH
HIGH PRESSURE OVER THE OHIO VALLEY. FORECAST SHOWS LARGER VARIANCES
WITH A LOW TRACKING INTO THE OHIO VALLEY FROM THE SOUTHWEST ON
WEDNESDAY AND SOME POPS WERE WARRANTED WITH THIS POTENTIAL SYSTEM.
A WARMUP WILL OCCUR OVERNIGHT SATURDAY AND TEMPERATURES FROM SUNDAY
THROUGH TUESDAY WILL REMAIN ABOVE FREEZING. WITH THE UNCERTAINTY ON
THE EVOLUTION OF THE WEDNESDAY SYSTEM...THREW IN SNOW WHERE TEMPS
WERE BELOW FREEZING TO START THE DAY WITH...THOUGH IT APPEARS THAT
IF PRECIP OCCURS IT WILL BE WITH A WARM FRONT AND MORE OF A
RAIN/FREEZING RAIN THAN SNOW.
&&
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
MVFR CEILINGS ACROSS MUCH OF THE REGION SHOULD FINALLY DISSIPATE
BETWEEN 21Z AND 00Z. ONCE THIS OCCURS EXPECT VFR CONDITIONS EXCEPT
AT KLUK WHERE SOME MIST MAY CAUSE VISIBILITY RESTRICTIONS LATE
TONIGHT. OTHERWISE WILL ONLY SEE HIGH AND MID CLOUDS WILL STREAM
ACROSS THE AREA. SURFACE WINDS WILL REMAIN LIGHT BUT GRADUALLY
VEER AROUND TO THE SOUTHEAST.
OUTLOOK...MVFR CEILINGS LIKELY LATE THURSDAY NIGHT INTO FRIDAY
WITH MVFR VISIBILITIES POSSIBLE. MVFR CEILINGS AND VISIBILITY
POSSIBLE AGAIN SUNDAY NIGHT INTO MONDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...SITES
NEAR TERM...SITES
SHORT TERM...SITES
LONG TERM...FRANKS
AVIATION...
AREA FORECAST DISCUSSION
NWS PORTLAND OR
235 PM PST WED FEB 6 2013
.SYNOPSIS...OCCASIONAL SHOWERS SHOULD CONTINUE THROUGH THE
DAY...PARTICULARLY ALONG THE COAST. STEADIER RAIN AND MOUNTAIN SNOW
WILL ARRIVE LATE THIS EVENING AS A COLD FRONT PUSHES EASTWARD ACROSS
THE AREA TONIGHT. EXPECT SHOWERY WEATHER WITH OCCASIONAL SUNSHINE ON
THURSDAY. BUILDING HIGH PRESSURE SHOULD LEAD TO LARGELY DRY WEATHER
OVER THE WEEKEND...EXCEPT ON SATURDAY WHEN LOW CLOUDS AND DRIZZLE
WILL BE POSSIBLE...PARTICULARLY ALONG THE COAST.
&&
.SHORT TERM...VISIBLE SATELLITE IMAGERY THIS AFTERNOON REVEALS A LOW
PRESSURE NEAR 130W MOVING TOWARDS VANCOUVER ISLAND. A FAIRLY WELL
DEFINED COLD FRONT IS JUST EAST OF 130W AND WILL MOVE ONSHORE THIS
EVENING. SATELLITE EXTRAPOLATION SUGGESTS THE MAIN FRONTAL
PRECIPITATION WILL ARRIVE ALONG THE COAST AROUND 7-9PM AND CLOSER TO
9-11PM FOR THE WILLAMETTE VALLEY. THE LATEST RUNS OF THE HRRR SUGGEST
SIMILAR TIMING SO I SHIFTED THE TIMING OF THE HIGHEST POPS TO A
LITTLE LATER IN THE EVENING. I DID HOWEVER KEEP POPS NEAR 100 ALONG
THE COAST WHERE SHOWERS WILL CONTINUE INTO THE EVENING...BUT LOWERED
THEM CONSIDERABLY FOR THE INTERIOR VALLEYS WHERE ONLY SCATTERED
PREFRONTAL SHOWERS ARE EXPECTED. EITHER WAY...EVERYONE SHOULD SEE
SOME FORM OF PRECIPITATION DURING THE OVERNIGHT HOURS AS THE MAIN
BAND OF VALLEY RAIN AND MOUNTAIN SNOW ASSOCIATED WITH THE FRONT
SPREADS INLAND.
SNOW LEVELS WILL LOWER FROM AROUND 3500 FT THIS EVENING TO NEAR 2000
FT THURSDAY MORNING. WHILE PRECIPITATION MAY BE RELATIVELY INTENSE
FOR A COUPLE HOURS OVERNIGHT...THE FAST MOVING NATURE OF THIS STORM
SYSTEM SHOULD KEEP SNOW AMOUNTS UNDER WINTER WX ADVISORY CRITERIA. A
WX STORY WAS ISSUED HIGHLIGHTING WINTER TRAVEL IMPACTS ACROSS THE
CASCADES TONIGHT.
A COOL UNSTABLE AIRMASS WILL FOLLOW FOR THURSDAY SO HIT OR MISS
SHOWERS WITH OCCASIONAL SUNSHINE LOOK LIKE A GOOD BET. 850MB WINDS
WILL DECREASE QUICKLY THURSDAY MORNING SO OROGRAPHICS WILL NOT BE
TERRIBLY PRONOUNCED. MODELS DO SUGGEST A MINI TROWAL LIKE FEATURE
MAY FOCUS SHOWERS THURSDAY AFTERNOON AND EVENING...MAINLY OFF THE
CENTRAL OREGON COAST. AS A RESULT...THE GREATEST POPS WERE HEDGED IN
THAT DIRECTION THURSDAY. INCREASING NORTHERLY FLOW AND DECREASING
INSTABILITY THURSDAY EVENING SHOULD LEAD TO SHOWERS DISSIPATING
QUICKLY. SHORTWAVE RIDGING ON FRIDAY SHOULD BRING INCREASING
SUNSHINE TO THE AREA.
MODELS ALL LOOSELY AGREE ENOUGH WARM AIR ADVECTION WILL OCCUR LATE
FRIDAY NIGHT INTO SATURDAY MORNING THAT SOME LIGHT RAIN OR DRIZZLE
WILL BE POSSIBLE...PARTICULARLY ALONG THE COAST. AS A RESULT...POPS
AND SKY COVER WERE INCREASED TO AT LEAST SUGGEST THERE IS A SHOT AT
THE DAY ENDING UP MORE WET THAN PREVIOUSLY ANTICIPATED. /NEUMAN
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...HIGH PRESSURE OVER
THE EAST PACIFIC CONTINUES OVER THE REGION THROUGH EARLY NEXT WEEK.
SEASONAL TEMPERATURES...DRY CONDITIONS AND PARTLY SUNNY SKIES WILL
PREVAIL. SOME OVERNIGHT/MORNING FOG MAY DEVELOP UNDER OFFSHORE FLOW
OVER THE WEEKEND. MODELS CONTINUE FUNDAMENTAL DISAGREEMENT
CONCERNING THE BREAKDOWN OF THE RIDGE NEXT WEEK. THE ECMWF AND GEM
HINT AT A FEW WEAK DISTURBANCES RIDING OVER THE TOP OF THE RIDGE AND
IMPACTING THE NORTHERN MOST PORTION OF THE CWA BY THE MIDDLE OF NEXT
WEEK...WHILE THE GFS KEEPS THE RIDGE STUBBORNLY OVER THE AREA. FOR
NOW...HAVE TRENDED THE FORECAST TOWARD THE ECMWF SOLUTION. BROWN
&&
.AVIATION...GENERALLY VFR AS OF 21Z WITH SOME AREAS OF MVFR.
LITTLE CHANGE IN EXPECTED CONDITIONS FOR THE 00Z TAFS. EXPECT
CIGS TO BECOME PRIMARILY MVFR AROUND 22Z ON THE S WA AND N OREGON
COAST...ABOUT 00Z THU ON THE CENTRAL COAST...AND AFTER 04Z THU
OVER THE INLAND VALLEYS. GOING FOR PREDOMINANT MVFR AFTER 04Z
THU...WITH GUSTY S WIND TO 40 KT ALONG ON THE COAST. MVFR CONDITIONS
WITH RAIN WILL CONTINUE THROUGH AT LEAST 12Z. AREAS OF IFR POSSIBLE
ALONG THE COAST BETWEEN 08Z AND 12Z THU WITH THE FRONT. EXPECT
MTNS AND PASSES TO BE OBSCURED. THE FRONT SHOULD REACH THE
CASCADES NEAR 15Z...BUT EXPECT IMPROVEMENT TO A VFR/MVFR MIX ALONG
THE COAST AND INLAND VALLEYS BY THAT TIME.
KPDX AND APPROACHES...VFR TO PREVAIL THROUGH THE EVENING
HOURS...ALTHOUGH MOST CIGS WILL BE HOVERING AROUND FL035.
THUS...THERE MAY BE SOME SHORT PERIODS OF HIGH-END
MVFR...ESPECIALLY ON WRN APPROACHES. CONDITIONS START TO WORSEN
AFTER 04Z THU AND EXPECT A DROP TO MVFR AROUND 06Z THU. RAIN
INCREASES AFTER 06Z WITH THE FRONT MOVING ACROSS THE TERMINAL
CLOSE TO 12Z. A VFR/MVFR MIX SHOULD DEVELOP AROUND 15Z...FOLLOWED
BY MAINLY VFR CONDITIONS BY 18Z. WEISHAAR
&&
.MARINE...SEAS HAVE SETTLED DOWN TO 13 TO 15 FT EARLY THIS
AFTERNOON. ENP GUIDANCE TRACKING QUITE WELL WITH AVAILABLE OBS.
COMBINED SEAS WILL BUILD THIS EVENING AND TONIGHT AS GALE
CONDITIONS BECOME MORE ESTABLISHED. LATEST NAM AND GFS MODEL RUNS
ARE NOT QUITE AS STRONG WITH THE BOUNDARY LAYER WIND SPEEDS VALID
00Z THU...GENERALLY 25-35 KT WITH THE STRONGEST WIND OVER THE
OUTER WATERS. WIND SPEEDS DROP OFF SUBSTANTIALLY BY 06Z THU. MAY
BE CARRYING THE GALE WARNING A LITTLE TOO LONG...BUT WILL LET THE
EVENING SHIFT EVALUATE THAT A BIT MORE. THE INCREASED WIND WILL
CREATE COMBINED SEAS CLOSE TO 20 FT...WITH A LARGE WIND-WAVE
COMPONENT. SEAS FALL BACK TO 12 TO 15 FT RANGE ON THU.
HIGH PRES WILL BUILD OVER THE REGION FRI AND SAT...WITH NW WINDS
20 KT OR LESS. SEAS WILL GRADUALLY DROP BACK UNDER 10 FT ON FRI
BUT CREEP BACK TO 10 FT SAT NIGHT AND SUN. WEISHAAR
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...GALE WARNING UNTIL 2 AM PST THURSDAY FOR COASTAL WATERS FROM
CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 4 PM
PST THURSDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
302 PM MST WED FEB 6 2013
.DISCUSSION...CURRENT SURFACE ANALYSIS SHOWS WEAK LOW PRESSURE OVER
CENTRAL ND...WITH A SURFACE TROF STRETCHING SOUTHWARD ACROSS
CENTRAL SD. UPPER LEVEL ANALYSIS SHOWS WEAK SHORTWAVE MOVING
ACROSS THE NORTHERN HIGH PLAINS...WITH A RIDGE BUILDING OVER THE
PACIFIC NW...AND A LOW OFF THE PACIFIC COAST. SKIES ARE PARTLY
SUNNY ACROSS MUCH OF THE AREA. REGIONAL RADARS NOT SHOWING MUCH IN
THE WAY OF ECHO RETURNS...EXCEPT FOR SOME WEAK RETURNS OVER THE
HIGHER TERRAIN OF WY AND THE BLACK HILLS. WITH ONLY WEAK LIFT AND
LIMITED LOW LEVEL MOISTURE IN PLACE...NOT EXPECTING MUCH MORE
THAN A FEW SPRINKLES/FLURRIES ACROSS THE BLACK HILLS THROUGH THE
AFTERNOON. TEMPS ARE CURRENTLY IN THE 40S AND LOWER 50S AT MOST
LOCATIONS. NORTHWESTERLY WINDS REMAIN BREEZY TO WINDY ACROSS
PORTIONS OF WESTERN SD...MAINLY FROM THE 2WX TO RAP CORRIDOR.
MILD WEATHER WILL CONTINUE THROUGH FRIDAY AS AN UPPER LEVEL RIDGE
SLIDES EAST ACROSS THE ROCKIES AND NORTHERN PLAINS. UPPER LOW OFF
THE PACIFIC NW COAST WILL MOVE SOUTHEAST INTO THE SOUTHWESTERN
CONUS LATE THIS WEEK...AND THEN TRACK ACROSS THE CENTRAL ROCKIES
AND PLAINS OVER THE WEEKEND. THE TRACK OF THE SYSTEM IS STILL
UNCERTAIN AT THIS POINT...BUT SOUTHERN PORTIONS OF THE CWA WILL
SEE THE BEST CHANCES FOR SNOW AND SOME ACCUMULATION...ESPECIALLY
ACROSS FAR SOUTHWESTERN INTO SOUTH CENTRAL SD.
FOR TONIGHT...SKIES WILL CLEAR OUT IN THE EVENING AS SHORTWAVE
MOVES EAST OF THE AREA. WINDS WILL ALSO DIMINISH AFTER SUNSET.
LOWS WILL MOSTLY BE IN THE 20S...WITH SOME TEENS IN THE USUAL
COLDER SPOTS. THE RIDGE WILL BUILD ACROSS THE AREA THURSDAY INTO
FRIDAY...WITH MOSTLY CLEAR SKIES AND MILD CONDITIONS PERSISTING.
THE WARMEST CONDITIONS WILL GENERALLY BE ACROSS WESTERN AND
CENTRAL AREAS ON THURSDAY AND ACROSS EASTERN AREAS ON FRIDAY.
BRISK SOUTHWESTERLY WINDS WILL DEVELOP LATE ON THURSDAY ACROSS
NORTHEASTERN WY AND THE NORTHERN BLACK HILLS AREA...PERSISTING
THROUGH THURSDAY NIGHT. SOME WIND GUSTS TO 40 MPH LOOK LIKELY
ACROSS FAVORED AREAS OF THE NORTHERN BLACK HILLS AND NORTHERN
FOOTHILLS.
AS THE RIDGE MOVES EAST BY FRIDAY NIGHT AND UPPER LOW MOVES INTO
THE CENTRAL ROCKIES...SOUTHWEST FLOW ALOFT WILL DEVELOP OVER THE
HIGH PLAINS. SHORTWAVE ENERGY IN THE FLOW AHEAD OF THE LOW WILL
TRACK ACROSS EASTERN WY OVERNIGHT. CLOUDS WILL INCREASE ACROSS THE
AREA...BUT LOW LEVEL MOISTURE WILL BE SLOW TO RETURN. THE SYSTEM
ALSO LOOKS TO BE A BIT SLOWER AS IT MOVES ACROSS THE ROCKIES. WILL
KEEP SOME LOW POPS FOR SNOW ACROSS SOUTHWESTERN PORTIONS OF
NORTHEASTERN WY AND DRY ELSEWHERE.
EXTENDED...POTENT EJECTING SW CONUS DISTURBANCE WILL SUPPORT A
STRONG WINTER STORM SYSTEM ACROSS THE CENTRAL AND NORTHERN PLAINS AT
THE START OF THE PERIOD...BRINGING WIND AND SNOW TO PORTIONS OF THE
FA. FORECAST MODELS HAVE COME TO CLOSE CONSENSUS PER THE
TRACK/STRENGTH/AND TIMING OF THIS SYSTEM...WITH AT LEAST
SEMI-NORTHERN STREAM FLOW PHASING STILL SUGGESTED IN ALL
DETERMINISTIC GUIDANCE. BRIEF BLOCKING PER THE EXPECTED WOUND UP SFC
CYCLONE AND ASSOCIATED UPPER LEVEL CLOSED LOW WILL LEAD TO A BRIEF
COOL DOWN THE EARLY PART OF NEXT WEEK AS LONG TRAJECTORY NORTHERLY
FLOW RESULTS OVER THE REGION. HOWEVER...SPLIT FLOW WILL QUICKLY
RETURN WITH WESTERN NOAM RIDGING SPILLING OVER INTO THE WESTERN
NORTHERN PLAINS BY EARLY NEXT WEEK...SLIGHTLY SLOWER THAN WHAT
PREVIOUS MODEL SOLUTIONS WHERE INDICATING. NO MAJOR CHANGES MADE TO
THE PREVIOUS FORECAST OTHER THAN CONTINUED THE TREND OF RAISING POPS
OVER SCENTRAL SD PER THIS WEEKEND/S STORM SYSTEM...DUE TO INCREASED
CONFIDENCE PER THIS SYSTEM/S TRACK GIVEN GROWING AGREEMENT PER
DETERMINISTIC MODELS. ANALYSIS OF FGEN/WAA/MID LAPSE RATES SUGGEST A
RATHER STRONG DEFORMATION ZONE WILL FORM OVER NORTHERN NE INTO
SD...WITH A PERIOD OF HEAVY SNOW LIKELY ESP GIVEN THE DEVELOPING
GOMEX CONNECTION INDICATED IN H85 THETA-E PROGS. THE EXACT TRACK OF
THE HEAVIEST SNOW IS STILL IN QUESTION...BUT CURRENT CONSENSUS
INDICATIONS SUGGEST INVOF TODD/MELLETTE/AND TRIPP COUNTIES AND
EAST...WHERE THE POTENTIAL FOR 4 TO 6 INCHES EXISTS. IN
ADDITION...VERY STRONG N/NW WINDS WOULD LIKELY CREATE AREAS OF
BLOWING AND DRIFTING SNOW...WITH SIG VIS REDUCTION. WILL FRESHEN THE
HWO FOR THIS CONCERN. THE REMAINDER OF THE FA WILL SEE MUCH LOWER
CHANCES FOR PRECIP WITH ACCUMS GENERALLY 2 INCHES TO A
DUSTING...SAVE THE NORTHERN BH WHERE HIGHER AMOUNTS ARE QUITE
POSSIBLE GIVEN A PERIOD OF UPSLOPE SUN/SUN NIGHT. COLD AIR WILL
SETTLE OVER THE REGION ON THE BACKSIDE OF THIS SYSTEM WITH BELOW
NORMAL TEMPS FORECAST MON. UPPER LEVEL RIDGING WILL DEVELOP BY
TUE...SUPPORTING WARMING TEMPS THROUGH WED...WITH NORMAL TO ABOVE
NORMAL TEMPS BY THEN...ESP IN AREAS THAN DON/T SEE MUCH SNOW THIS
WEEKEND.
&&
.AVIATION...18Z TAFS
VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD...EXCEPT THAT SCT
MVFR CIGS ARE POSSIBLE ACROSS THE BLKHLS AND FAR NERN WY THIS
AFTN. AN UPPER TROUGH WILL MOVE QUICKLY ACROSS THE AREA TODAY...
BRINGING CONSIDERABLE MID AND HIGH LEVEL CLOUDS. WINDS WILL SHIFT
TO THE NORTHWEST AND BE GUSTY OVER PARTS OF THE PLAINS. SLIGHTLY
UNSTABLE CONDITIONS MAY FOSTER A FEW SHOWERS OVER THE BLKHLS THRU
24Z. WINDS WILL RELAX THIS EVENING...BACKING TO THE S ACROSS NE
WY THROUGH THUR AM.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...26
LONG TERM....JC
AVIATION...JC
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
304 PM CST WED FEB 6 2013
.SHORT TERM...TONIGHT AND THURSDAY.
WINTER WEATHER ADVISORY FOR SNOW AND FREEZING DRIZZLE IS THE MAIN
CONCERN DURING THIS PART OF THE FORECAST. MODELS SHOWED
SIGNIFICANT UPPER LEVEL DIVERGENCE ACROSS MUCH OF THE FORECAST
AREA LATE THIS AFTERNOON AND TONIGHT. THIS WAS ASSOCIATED WITH
THE RIGHT ENTRANCE REGION OF A 120+ KNOT 300MB JET MAX. STRONG
UPPER DIVERGENCE ASSOCIATED WITH A WEAKER JET MAX RETURNS TO THE
AREA ON THURSDAY. THE COMBINATION OF LIFT FROM WARM ADVECTION AND
UPPER DIVERGENCE WAS PRODUCING A BAND OF SNOW THAT EXTENDED FROM
THE MINNESOTA ARROWHEAD SOUTHEAST TO SOUTHERN WISCONSIN. SNOWFALL
IN THIS BAND WAS RATHER HEAVY SO IT SHOULD PRODUCE A QUICK
ACCUMULATION OF AN INCH OR TWO AS IT PASSES. RADAR SHOWED A BAND
OF ECHOES ACROSS NORTHERN IOWA BUT SURFACE OBSERVATIONS WERE NOT
INDICATING PRECIPITATION WITH THIS FEATURE. THE 18Z RUC SHOWED QPF
IN THIS AREA SPREADING NORTHEAST INTO CENTRAL AND EASTERN
WISCONSIN OVERNIGHT. MODELS HINTED AT SOME MID LEVEL DRYING
AFTER MIDNIGHT SO HAVE FREEZING DRIZZLE MENTIONED ALONG WITH THE
SNOW.
AN INVERTED SURFACE TROUGH AXIS IS EXPECTED TO PASS THROUGH THE
AREA ON THURSDAY. A 500MB SHORT WAVE APPROACHING THE STATE WILL
COMBINE WITH THE UPPER DIVERGENCE AND SURFACE BOUNDARY TO PRODUCE
MORE SIGNIFICANT SNOWFALL...MAINLY ACROSS EAST CENTRAL WISCONSIN.
TIME/HEIGHT SECTIONS FROM THE 12Z NAM/12Z GFS/09Z SREF DID NOT
INDICATE FREEZING PRECIPITATION FOR ANY OF THE LOCATIONS IN THE
AREA DURING THE SHORT TERM...THOUGH THEY DID IN THE MSN AND MKE
AREAS. HPC WINTER PRECIPITATION GUIDANCE KEPT ANY MEASURABLE
FREEZING PRECIPITATION SOUTH OF THE AREA WITH 24 HOUR TOTALS
THROUGH 00Z FRIDAY OF 6+ INCHES FROM JUST EAST OF GREEN BAY AND
THE FOX CITIES TO LAKE MICHIGAN.
.LONG TERM...THU NGT THRU NEXT WED. A NEARLY ZONAL FLOW ACROSS THE
CONUS AT THE ONSET TO TRANSITION TO AN AMPLIFIED FLOW THIS WEEKEND
AS A LARGE UPR RDG BUILDS OFF THE WEST COAST AND A DOWNSTREAM
LONGWAVE TROF SETS UP OVER THE ROCKIES INTO THE CNTRL CONUS. MDLS
CONT TO SHOW A MAJOR SYSTEM WL LIFT NE FROM CO INTO THE GREAT
LAKES SAT NGT INTO MON BRINGING SNOW AND MIXED PCPN TO NE WI. MEAN
FLOW EVENTUALLY BECOMES SPLIT OVER THE ERN PACIFIC WITH THE UPR
TROF SHIFTING EAST. HOWEVER...A SFC HI SHOULD KEEP THE WEATHER
RELATIVELY QUIET WITH TEMPS OVERALL SLIGHTLY ABOVE NORMAL.
LIGHT SNOW TO LINGER INTOI THU EVENING AS THE SHORTWAVE TROF MOVES
THRU WI. CONCERNED ABOUT ERN WI WHERE LIFT IS STRONGER AND WINDS
JUST ABOVE THE SFC ARE FCST TO BE N-NE. MAY NEED TO RAISE POPS A
BIT...ESPECIALLY IN THE EAST WHERE LAKE ENHANCEMENT TO TAKE PLACE
AND THIS COULD ADD UP TO AN INCH OF ADDITIONAL ACCUMULATION. PCPN
WL TAPER OFF FROM WEST TO EAST DURING THE OVRNGT HOURS...ALTHO THE
LAKESHORE MAY NOT SEE THE SNOW COME TO A COMPLETE END TIL CLOSE TO
DAYBREAK. HI PRES BUILDING INTO THE WRN GREAT LAKES LATER THU NGT
COULD BEGIN TO BREAK UP THE CLOUDS ACROSS CNTRL WI AND MAY NEED TO
LWER TEMPS A BIT TO COMPENSATE. THIS AREA OF HI PRES WL BE SITUATED
OVER WI ON FRI PROVIDING FOR PLENTY OF SUNSHINE...LIGHT WINDS AND
TYPICAL TEMPS FOR EARLY FEBRUARY. LOOK FOR READINGS TO GENERALLY
REACH THE 25-30 DEG RANGE OVER ALL OF NE WI.
THE HI PRES BEGINS TO SLIDE TO OUR EAST FRI NGT ALLOWING A RETURN
FLOW TO DEVELOP OVER WI. THE ONSET OF WEAK ISEN LIFT SHOULD BRING
SOME HI CLOUDS INTO THE FCST AREA...HOWEVER STILL EXPECT TEMPS TO
DROP OFF DUE TO FRESH SNOW AND LIGHT WINDS. PREFER THE COLDER SIDE
OF GUIDANCE AND HAVE SIGNIFICANTLY CHOPPED TEMPS INTO THE SINGLE
DIGITS/LOWER TEENS. AS THE LONGWAVE TROF CHUGS ACROSS THE ROCKIES
ON SAT...LEE-SIDE CYCLOGENESIS TO TAKE PLACE OVER SE CO AS A SFC
LOW QUICKLY INTENSIFIES. MEANWHILE...THE SFC HI CONTS TO PULL
FARTHER EAST AND THE SOUTH WINDS STEADILY INCREASE AS THE PRES
GRADIENT TIGHTENS. THESE SOUTH WINDS WL ALSO HELP BRING GULF
MOISTURE NWD...SO WE SHOULD SEE CLOUDS ON THE INCREASE DURING THE
DAY. MAX TEMPS ARE EXPECTED TO REACH NEAR THE 30 DEG MARK DESPITE
THE CLOUDS.
AS A 110+ KT UPR JET ROUNDS THE BASE OF THE UPR TROF...THE SFC LOW
IS FCST TO START MOVING NE INTO THE CNTRL PLAINS SAT NGT AND REACH
THE MIDWEST (VICINITY NW IA) ON SUNDAY. LOW-LEVEL MOISTURE CONTS
TO STREAM INTO WI WITH A WRMFNT LIFTING TO THE WI/IL BORDER BY
SUNDAY AFTERNOON. MID-LEVEL FORCING (BOTH Q-G AND FRONTOGENETICAL)
INCREASE DURING THIS PERIOD OVER THE REGION WITH THE LEFT EXIT
REGION OF THE UPR JET ADDING LIFT. EXPECT TO SEE PCPN GRADUALLY
OVERSPREAD WI ON SUNDAY...BUT WHAT TYPE OF PCPN? WHILE MOST OF THE
MDLS ARE GETTING CLOSER TO A FINAL TRACK SOLUTION (EXCEPT THE GEM
WHICH REMAINS SOUTH)...THE THERMAL FIELDS VARY BETWEEN THE WARMER
GFS AND THE COOLER ECWMF/UKMET. DIFFICULT TO DETERMINE WHAT THE
SFC TEMPS TO BE AT ONCE THE PCPN BEGINS...AS THIS WOULD PLAY A
LARGE ROLE IN DETERMINING RAIN VS. FREEZING RAIN VS. SNOW. IN
ESSENCE...IT IS JUST TOO EARLY TO TRY AND PINPOINT PCPN TYPES AT
THIS TIME...OTHER THAN N-CNTRL WOULD HAVE THE BEST CHC OF SEEING
ALL SNOW AND E-CNTRL WI WOULD HAVE THE BEST CHC OF SEEING MORE
RAIN THAN SNOW WITH A MIX IN BETWEEN.
SNOW/MIXED PCPN WL CONT SUNDAY NGT AS THE SFC LOW TRACKS NE INTO
N-CNTRL WI WITH THE BETTER SNOW ACCUMULATION OCCURRING OVER THE NW
1/4 OF WI. THIS WOULD LIKELY CLIP PARTS OF N-CNTRL WI...BUT FOR
MOST OF THE FCST AREA...TOO MUCH OF A MIX WL LIMIT SNOW AMOUNTS.
AS THE SFC LOW PULLS AWAY ON MON AND COLDER AIR GETS PULLED SWD...
ANY LINGERING MOISTURE WOULD TRANSITION BACK TO ALL SNOW. SINCE
DEEPER MOISTURE TO ALREADY HAVE EXITED...DO NOT EXPECT TO SEE MUCH
ADDITIONAL ACCUMULATION ON MON...ESPECIALLY IF SOME FREEZING
DRIZZLE MIXES IN. OTHER THAN SOME LIGHT LAKE EFFECT SNOW SHWRS
OVER VILAS CNTY MON NGT...THE WEATHER BECOMES FAIRLY TRANQUIL WITH
PERHAPS SOME FLURRIES ON TUE AS THE POSITIVE-TILTED UPR TROF MOVES
THRU THE GREAT LAKES. HI PRES PASSING TO OUR SOUTH ON WED WL BRING
A DRY DAY WITH TEMPS WARMING UP A BIT.
&&
.AVIATION...DISCUSSION FOR 18Z TAFS...CONDITIONS WILL DETERIORATE THIS
AFTERNOON AND EVENING AS MAINLY VFR CIGS AND VSBYS ACROSS THE AREA
BECOME IFR IN SNOW... WITH SOME FREEZING DRIZZLE ALSO POSSIBLE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 PM CST THURSDAY FOR WIZ013-
020>022-030-031-035>040-045-048>050-073-074.
&&
$$
MG/KALLAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
223 PM CST WED FEB 6 2013
.SHORT TERM...TONIGHT THROUGH SATURDAY
223 PM CST WED FEB 6 2013
LATEST WATER VAPOR IMAGERY/RAP 500MB ANALYSIS/RADAR MOSAIC SHOWING A
COUPLE MID-LEVEL SHORTWAVE TROUGHS AFFECTING THE AREA THROUGH THE
NEXT 24 HOURS. WAVE NUMBER ONE WAS CURRENTLY PRODUCING SOME LIGHT
SNOW ACROSS PORTIONS NORTHERN MN INTO CENTRAL WI. WAVE NUMBER 2
WHICH IS MORE VIGOROUS WAS MOVING EAST OUT OF WESTERN SD/NEB. THIS
WAVE ALREADY PRODUCING SOME LIGHT RAIN ACROSS PORTIONS OF NORTHWEST
IA WITH RADAR MOSAIC SHOWING MID-LEVEL RETURNS HEADED THIS WAY.
MEANWHILE...TEMPERATURES ACROSS THE AREA RANGED FROM THE UPPER TEENS
ACROSS NORTH CENTRAL WI...TO THE UPPER 20S/LOWER 30S ACROSS PORTIONS
OF NORTHEAST IA.
LATEST MODELS ALL IN PRETTY GOOD AGREEMENT WITH SYNOPTIC PATTERN
THROUGH THE NEXT COUPLE OF DAYS. THE NAM SEEMS A BIT SHY ON
PRECIPITATION AMOUNTS GIVEN FORCING SIGNALS TONIGHT INTO THURSDAY.
USED A BLEND OF THE GFS/SREF AS WELL AS THE GEM/ECMWF FOR QPF
AMOUNTS.
AFOREMENTIONED WAVE NUMBER 2 OVER WESTERN SD/NEB WILL PROGRESS
EASTWARD WITH INCREASING 925-850MB MOISTURE TRANSPORT AND ISENTROPIC
LIFT INTO THE AREA. THIS IS EXPECTED TO SPREAD FREEZING RAIN/SLEET
INTO OUR AREA ALONG AND SOUTH OF I-94 WITH A MIX OF
SNOW/SLEET/FREEZING DRIZZLE OR RAIN NORTH OF I-94. PLAN ON THIS
WINTRY MIX TO CONTINUE INTO AT LEAST THURSDAY MORNING BASED ON
SOUNDING DATA PROFILES. EXPECTING TO SEE TRACE TO AS MUCH AS 2/10 OF
AN INCH OF ICE WITH SNOW AMOUNTS MAINLY ALONG AND NORTH OF I-94 IN
THE 1/2 TO 2 INCH RANGE. ANOTHER DEEPER MID-LEVEL TROUGH DROPS
SOUTHEAST INTO THE AREA THURSDAY AFTERNOON FOR PERHAPS ENOUGH
ICE/DYNAMIC COOLING IN THE COLUMN TO TRANSITION TO MORE SNOW IN THE
AFTERNOON. BASED ON THE EXPECTED WINTRY MIX...WENT WITH A WINTER
WEATHER ADVISORY FROM 6 PM THIS EVENING THROUGH 6 PM THURSDAY.
SCATTERED SNOW FLURRIES ARE THEN EXPECTED ACROSS THE AREA THURSDAY
EVENING AS THE COLUMN CONTINUES TO COOL WITH THE TROUGH ROTATING
OVERHEAD. TROUGH EXITS THE AREA AFTER MIDNIGHT...BRINGING AN END TO
THE FLURRIES. A RIDGE OF HIGH PRESSURE WILL PROVIDE MOSTLY
SUNNY/QUIET CONDITIONS FRIDAY WITH HIGHS TOPPING OFF IN THE UPPER
20S TO LOWER 30S.
PLAN ON INCREASING CLOUDS FRIDAY NIGHT THROUGH SATURDAY AHEAD OF LOW
PRESSURE GETTING ORGANIZED ON THE LEESIDE OF THE COLORADO ROCKIES.
WARM AIR ADVECTION IN SOUTHERLY AIRFLOW SHOULD PUSH TEMPERATURES
WELL INTO THE 30S.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
223 PM CST WED FEB 6 2013
THE MAIN FOCUS IN THE EXTENDED PERIOD IS WITH THE SYSTEM THAT MOVES
THROUGH THE REGION SATURDAY NIGHT THROUGH SUNDAY NIGHT. THE 06.12Z
GFS/ECMWF HAVE COME INTO FAIRLY GOOD AGREEMENT WITH A CONTINUED
NORTHWARD SHIFT WITH THE TRACK OF THE LOW. THIS SYSTEM IS CURRENTLY
LOCATED OFF OF THE COAST OF THE PACIFIC NORTHWEST AND WILL STALL OUT
ACROSS THE CENTRAL US ROCKIES EARLY THIS WEEKEND. THE EASTERN
PORTION OF THE TROUGH EJECTS OUT TO THE NORTHEAST INTO THE NORTHERN
PLAINS SATURDAY NIGHT INTO EARLY SUNDAY. THE 06.12Z GFS/ECMWF ARE
AGAIN VERY CONSISTENT WITH THIS RUN FOR TAKING THE CORE OF THE LOW
FROM EASTERN COLORADO SATURDAY NIGHT THROUGH CENTRAL MINNESOTA BY
SUNDAY NIGHT AND THEN INTO THE UPPER GREAT LAKES MONDAY. AT THE
SURFACE...THE LOW IS EXPECTED TO TRACK FROM NORTH CENTRAL IOWA
SUNDAY INTO NORTHERN WISCONSIN BY SUNDAY NIGHT. THIS LEADS TO THE
REGION BEING IN THE WARM SECTOR FOR MOST OF THIS SYSTEM WITH RAIN
BEING THE MAIN PRECIPITATION TYPE. THE BIGGEST CONCERN WILL BE AS
THE PRECIPITATION MOVES IN FROM THE SOUTH SATURDAY NIGHT MIXED
PRECIPITATION TYPES POSSIBLE. DETAILS WILL EMERGE OVER THE NEXT FEW
DAYS...BUT 06.12Z GFS BUFKIT SOUNDINGS SHOW A WARM LAYER OVER A SUB
FREEZING NEAR SURFACE LAYER THAT WOULD LEAD TO A MIX OF SLEET AND
FREEZING RAIN AT THE ONSET. THE LOW LEVEL PROFILE THEN WARMS ENOUGH
THAT MUCH OF SUNDAY SHOULD JUST BE RAIN BEFORE COLDER AIR MOVES IN
ON THE BACK SIDE SUNDAY NIGHT INTO MONDAY.
NOT MUCH IN THE WAY OF COLD AIR ADVECTION ON THE BACK SIDE OF THIS
AMPLIFIED SYSTEM...SO THERE SHOULD NOT BE MUCH OF A COOL DOWN AFTER
THE SYSTEM PASSES. HIGH PRESSURE BUILDS IN AND CONDITIONS SHOULD
REMAIN DRY THROUGH MID WEEK.
&&
.AVIATION...THROUGH 18Z THURSDAY
1154 AM CST WED FEB 6 2013
MAIN FORECAST CONCERN IS THE MOISTENING OF THE NEAR SURFACE BOUNDARY
LAYER THIS EVENING INTO TONIGHT AND THE POTENTIAL FOR FREEZING
DRIZZLE TO DEVELOP AT BOTH RST AND LSE TAF SITES AFTER 06Z
THURSDAY. VFR CONDITIONS SHOULD PREVAIL AT THE TAF SITES THROUGH
00Z TO 05Z THURSDAY. THE LATEST 06.12Z GFS/NAM AND 06.15Z RAP
MODELS ARE IN AGREEMENT SURGING LOW LEVEL MOISTURE OVER EASTERN
KANSAS AND EASTERN NEBRASKA INTO THE REGION TONIGHT. THE MODELS DO
SUGGEST ISENTROPIC LIFT AT THE 290K SURFACE IN ASSOCIATION WITH
THIS MOISTURE. THE 06.12Z GFS/NAM AND 06.15Z RAP BUFKIT SOUNDINGS
SHOW LOSS OF ICE IN THE ATMOSPHERE COLUMN AND INDICATE DEVELOPMENT
OF FREEZING DRIZZLE AND CEILINGS/ VISIBILITIES REDUCED TO IFR
CONDITIONS AFTER 06Z TO 09Z AT BOTH RST AND LSE TAF SITES. THE
BUFKIT SOUNDINGS INDICATE THE IFR CONDITIONS AND FREEZING DRIZZLE
TO CONTINUE THROUGH THE REST OF THE TAF PERIOD AND POSSIBLY AFTER
18Z THURSDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
223 PM CST WED FEB 6 2013
WI...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 PM CST
THURSDAY FOR WIZ017-029-032>034-041>044-053>055-061.
MN...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 PM CST
THURSDAY FOR MNZ079-086>088-094>096.
IA...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 PM CST
THURSDAY FOR IAZ008>011-018-019-029-030.
&&
$$
SHORT TERM...DAS
LONG TERM...HALBACH
AVIATION...DTJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1158 AM CST WED FEB 6 2013
.SHORT TERM...
1147 AM CST WED FEB 6 2013
HAVE REVISITED THE IMPACT OF THE WINTRY MIX MOVING IN FOR TONIGHT.
EXPECT THE NORTHERN STREAM SHORTWAVE TROUGH TO BRING SNOW TO THE
NORTHERN AREAS TODAY. CURRENT MOISTURE TRANSPORT MOVING INTO IOWA
AND FORCING INCREASING LATER THIS AFTERNOON...SHOULD SEE A MIX SPREADING
IN FROM THE SOUTHWEST. WE EXPECT THIS TO OVERSPREAD THE AREA
TONIGHT...HOWEVER THE GREATEST IMPACT WILL BE NORTHEAST IOWA AND
SOUTHWEST WISCONSIN. WHILE WARMING WILL OCCUR...ROAD TEMPERATURES
ARE EXPECTED TO BE NEAR FREEZING OR BELOW CAUSING A FREEZING RAIN
SCENARIO. FORECAST IN THE PROCESS OF BEING UPDATED. WEB SHOULD
HOLD LATEST FORECAST.
WILL ISSUE A WINTER WEATHER ADVISORY FROM 6 PM TONIGHT TO 6 PM
THURSDAY FOR THE ENTIRE AREA FOR THIS MIXED PRECIPITATION. WE
EXPECT FREEZING DRIZZLE TO LINGER THURSDAY AFTER THE SNOW CHANCES
END...THUS THE NORTHERN AREA WILL BE IN ADVISORY AS WELL.
.LONG TERM...SATURDAY THROUGH TUESDAY
353 AM CST WED FEB 6 2013
06.00 FORECAST MODELS ARE IN REASONABLE AGREEMENT SATURDAY INTO
SUNDAY BRINGING A STRONG LOW PRESSURE SYSTEM FROM THE SOUTHWEST INTO
THE UPPER MISSISSIPPI RIVER VALLEY. UNCERTAINTY REMAINS IN THE EXACT
TRACK OF THE SURFACE LOW. THE ECMWF AND GFS TAKE THE LOW ACROSS
NORTHERN WISCONSIN. THE GEM IS FURTHER SOUTH WITH THE LOW TRACKING
ACROSS NORTHERN ILLINOIS. CONFIDENCE IS INCREASING THAT THE AREA
WILL SEE PRECIPITATION SO HAVE INCREASED PRECIP CHANCES SUNDAY INTO
SUNDAY NIGHT. IF THE GEM IS RIGHT THE FORECAST AREA WOULD BE IN FOR
A SIGNIFICANT SNOWFALL. IF THE ECMWF AND GFS ARE ON THE RIGHT TRACK
THE FORECAST AREA WOULD SEE MORE OF A RAIN/SNOW MIX. WILL HAVE TO
CONTINUE KEEPING A CLOSE WATCH ON THIS SYSTEM. TEMPERATURES ARE
EXPECTED TO COOL MONDAY INTO TUESDAY IN THE WAKE OF THE POTENT
LOW. AFTER TEMPERATURES CLIMBING INTO THE MID 30S ON
SUNDAY...HIGHS WILL FALL BACK INTO THE 20S BY TUESDAY.
&&
.AVIATION...THROUGH 18Z THURSDAY
1154 AM CST WED FEB 6 2013
MAIN FORECAST CONCERN IS THE MOISTENING OF THE NEAR SURFACE BOUNDARY
LAYER THIS EVENING INTO TONIGHT AND THE POTENTIAL FOR FREEZING
DRIZZLE TO DEVELOP AT BOTH RST AND LSE TAF SITES AFTER 06Z
THURSDAY. VFR CONDITIONS SHOULD PREVAIL AT THE TAF SITES THROUGH
00Z TO 05Z THURSDAY. THE LATEST 06.12Z GFS/NAM AND 06.15Z RAP
MODELS ARE IN AGREEMENT SURGING LOW LEVEL MOISTURE OVER EASTERN
KANSAS AND EASTERN NEBRASKA INTO THE REGION TONIGHT. THE MODELS DO
SUGGEST ISENTROPIC LIFT AT THE 290K SURFACE IN ASSOCIATION WITH
THIS MOISTURE. THE 06.12Z GFS/NAM AND 06.15Z RAP BUFKIT SOUNDINGS
SHOW LOSS OF ICE IN THE ATMOSPHERE COLUMN AND INDICATE DEVELOPMENT
OF FREEZING DRIZZLE AND CEILINGS/ VISIBILITIES REDUCED TO IFR
CONDITIONS AFTER 06Z TO 09Z AT BOTH RST AND LSE TAF SITES. THE
BUFKIT SOUNDINGS INDICATE THE IFR CONDITIONS AND FREEZING DRIZZLE
TO CONTINUE THROUGH THE REST OF THE TAF PERIOD AND POSSIBLY AFTER
18Z THURSDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
1146 AM CST WED FEB 6 2013
WI...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 PM CST
THURSDAY FOR WIZ017-029-032>034-041>044-053>055-061.
MN...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 PM CST
THURSDAY FOR MNZ079-086>088-094>096.
IA...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 PM CST
THURSDAY FOR IAZ008>011-018-019-029-030.
&&
$$
SHORT TERM...SCHMIDT/JONES/TH/DB
LONG TERM...WETENKAMP
AVIATION...DTJ